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Physiology

Post-Acute Effect of SARS-CoV-2 Infection on the Cardiac Autonomic Fun | IJGM – Dove Medical Press

Introduction

SARS-CoV-2 (COVID-19) infection was first reported in China in late December 2019. It has quickly escalated to become a global pandemic causing a catastrophic effect on the world. Cases are increasing all around the world, and the number of people infected reached hundreds of millions, with about 6 million deaths in the first quarter of 2022 worldwide.1,2

Recently, many reports showed a long-term effect of COVID infection that could extend beyond the active disease and the respiratory system. Disturbance in sleep, concentration impairment, fatigue, and palpitations are part of the long-lasting effect of COVID-19 (also known as LONG COVID).3 Post-COVID-19 syndrome is a group of symptoms that affect various body systems after being acutely infected by COVID-19. The symptoms can last longer than 12 weeks after COVID-19 infection, which cannot otherwise be explained alternatively.4 The development of post-COVID-19 syndrome is higher following severe acute illness, but it may develop after mild and moderate acute COVID-19.5,6

A wide spectrum of body dysfunctions has been linked to the chronic effect of COVID-19 infection, including disturbed lung function, endothelitis, thromboembolism, kidney failure, gastrointestinal impairment, mood changes, cognitive disturbances, and hyperglycemia without diabetes mellitus.7 Cardiovascular complication such as myocardial ischemia, infarction, myocarditis, and cardiac arrhythmias are noticeable sequelae of COVID-19 infection, with different suggested pathophysiological mechanisms involving direct damage to the circulatory system due to binding of viruses to angiotensin-converting-enzyme 2 receptors (ACE2), and systemic inflammation.8 However, the consequence of COVID-19 infection on the autonomic regulation of the heart remains unclear.

The autonomic nervous system (ANS) plays a key role in the regulation of the cardiac rhythm.9 Heart rate variability (HRV), cardiovascular autonomic reflex test (CART), andbaroreceptor sensitivity (BRS) are non-invasive assessment tools for the autonomic nervous system functions.10,11 Specifically, HRV aids in the evaluation of the sympathetic and parasympathetic functions on the cardiovascular system. Therefore, reflecting dysautonomia and sympathovagal balance.12

Dysautonomia is commonly recognized as a failure in the functions of the autonomic nervous system that can include various symptoms and signs such as fatigue, postural hypotension, changes in blood pressure, arrhythmias, and bladder and bowel function impairment.13 Dysautonomia following viral infections is not uncommon; many viral infections could cause dysautonomia including HIV, mumps, EBV, HBV as well as Coxsackie B virus.14 Recent reports link dysautonomia with COVID-19 infection.15 Involvement of the nervous system occurs probably by direct viral invasion, synaptic spread, or through the blood. Additionally, immunological damage, vascular damage, and hypoxia due to COVID-19 pneumonia, are proposed pathogenic mechanisms for COVID-19 neurological manifestations.16

Orthostatic hypotension (OH) and postural tachycardia syndrome (POTS) have been reported in the post-acute phase of COVID-19 infection.17 Another recent questionnaire-based cross-sectional study found that post-COVID autonomic disturbances are mostly manifested as orthostatic hypotension, gastrointestinal disturbances, and secretomotor abnormalities.18 Additionally, Adler et al reported a reduction in the HRV among post-COVID patients 3 and 6 months after recovery, which may increase the cardiovascular risk among post-COVID survivors.19 In contrast, parasympathetic overactivity with increased HRV was found after 12 weeks from the acute COVID-19 infection.20 Cardiovascular dysautonomia was also detected in about 15% of recently recovered COVID-19 patients (within 3045 days), with a significantly lower HRV compared to healthy controls.21 Autonomic nervous system dysfunction has also been revealed during the early phase of SARS-CoV-2 infection, with a significant reduction in HRV, BRS, and high incidence of orthostatic hypotension, indicating significant cardiovascular risk.22

However, there is a paucity of research on the chronic sequelae of COVID-19 infection on cardiac ANS functions. Thus the current study aimed to evaluate the post-acute impact of COVID-19 infection on cardiac autonomic nervous system functions, using cardiovascular reflex tests (CARTs), heart rate variability (HRV), and cardiac baroreceptor sensitivity (cBRS).

This was a comparative cross-sectional observational study carried out in the physiology departments laboratories at Imam Abdulrahman Bin Faisal University (IAU), College of Medicine, Saudi Arabia, in the period between November 7, 2021, and March 14, 2022. The study population was divided into two groups: controls (n=31) who neither tested positive nor had a history of COVID-19 before, and post-COVID patients (n=28) who tested positive PCR for COVID-19 at least 3 months before recruitment. We determined the sample size based on previous studies with comparable outcomes, where the sample size ranged from 2519 to 15222 participants.

Confirmation of COVID infection is based on positive testing of SARS-CoV-2 unique viral sequencing by using real-time reverse-transcription polymerase chain reaction (rRT-PCR).23

Subjects were excluded if they had: severe acute illness needing hospitalization, nervous system disorders (eg, multiple sclerosis, Parkinsonism, polyneuropathy, and Guillain-Barr syndrome), heart disease (eg, valvular heart disease, cardiomyopathy, arrhythmia, ischemic or congestive diseases), alcoholism, liver disease, malignancies, inflammatory diseases, renal diseases, or taking anti-hypertensive treatments.

Over the recruitment period, the medical records of COVID-19 patients in King Fahad University Hospital (KFUH) were reviewed and those fulfilling the inclusion criteria were contacted to do the autonomic function tests in our physiology laboratory.

The study followed the principles of the Declaration of Helsinki,24 and was approved by the Institutional Review Board of Imam Abdulrahman Bin Faisal University (IRB-UGS-2021-01-391). Informed written consent was obtained from every participant.

Experimental data was obtained by measuring (1) the baseline cardiovascular autonomic activity through heart rate variability (HRV), (2) cardiovascular reactivity through cardiovascular reflex tests (CARTs), and (3) cardiac baroreceptor reflex sensitivity through determination of baroreceptor sensitivity (cBRS).

After an initial rest of 5 minutes in a supine position on a tilt table, resting HR and BP were measured with SPOT vital sign monitor (NY 13153). The subjects were properly strapped to the tilt table and hooked up to an 8 channel Powerlab 8/35 system (ADInstrumennts, Australia) for continuous recording of ECG, respiratory rate and finger arterial blood pressure. Single lead ECG was recorded by attaching two ECG electrodes on both shoulders through ECG box and bio-amplifier (ADInstruments, Australia). Respiratory rate was monitored through the respiratory belt (ADInstruments, Australia). Continuous finger arterial BP waveform was recorded through Finometer Pro (FMS, Amsterdam, Netherlands) that was adjusted against the brachial cuff BP. The pressure signal was fed to the PowerLab for recording. After a stabilization rest period of 5 minutes, baseline recording was done for 5 minutes.

Analysis of HRV was done through the software LabChart Pro (V. 8.1.13) and HRV module. The following HRV parameters were analyzed in time-domain: SDRR (standard deviation RR intervals) reflecting overall HRV, RMSSD (root mean square of successive differences of RR intervals), and pRR50 (percentage of successive RR intervals that are different by at least 50 msec). Both RMSSD and pRR50 provide information about parasympathetic function. The frequency domain parameters that were analyzed included total power (TP), which represents the overall total HRV, low-frequency (LF) and very low-frequency (VLF) bands indicating the sympathetic activity, high-frequency band (HF) to reflect parasympathetic activity, and LF/HF ratio to demonstrate the sympathetic-parasympathetic balance.12 Frequency domain HRV parameters LF and HF were computed both as absolute values (ms2) and in normalized units. To control for the possible confounding effect of respiration on HRV parameters, respiratory rate was measured via a respiratory belt.22

Heart rate response to deep breathing, Valsalva maneuver and head-up tilt (HUT) were used to assess the parasympathetic function. Diastolic blood pressure responses to HUT and sustained isometric handgrip (IHG) were used to assess the sympathetic function.

Participants were asked to complete six respirations in one minute under guidance of the examiner, whereby they had to inhale deeply for 5 seconds and exhale fully for 5 seconds in a smooth and continuous manner completing one respiratory cycle in 10 seconds. The differences between the highest and lowest HR during deep breathing was calculated. In addition, the ratio of maximum RR interval during expiration to minimum RR interval during inspiration (E:I ratio) was also calculated.10,11

The participants were instructed to exhale into a large dial aneroid sphygmomanometer, and were coached to keep the pressure at 40 mmHg for 15 seconds. The maneuver was performed thrice by every participant, with an intervening rest period of 2 minutes. The longest RR interval in the Phase IV and the shortest RR interval during the late Phase II of VM were identified from the ECG recording to calculate the Valsalva ratio.10,11

After a resting period of lying down in supine position for 5 minutes, the table was tilted to 70 degrees and maintained for 5 minutes in this position. The table was tilted back and remained in supine position for another 5 minutes (Figure 1). The change in the heart rate was expressed as a ratio of the fastest heart rate (shortest RR interval) around the 15th beat to the slowest HR (longest RR interval) around the 30th beat after the head-up tilt.10,11

Figure 1 Heart rate response and blood pressure changes during head-up tilt procedure in post-acute COVID-19 patient; 20-year-old male, complained of headache, general fatigue, and subjective postural hypotension.

Systolic and diastolic blood pressures were noted in the supine position as baseline measurements. Readings were taken again after 12 minutes after the tilt at 70 degrees (Figure 1).25,26

After determining the maximum voluntary contraction with isometric force transducer, the participants were instructed to maintain the isometric handgrip for 3 minutes, during which the blood pressure was continuously recorded.10,11

An HR variation equal to or greater than 15 bpm or an expiratory/inspiratory ratio (E:I) of greater than or equal to 1.21 during DB were taken as normal. Similarly, a Valsalva ratio (VR) of equal to or greater than 1.21 was taken as normal. An HR response in the form of 30:15 R-R ratio of equal to or greater than 1.04 to HUT was taken as normal. An increase of DBP equal to or greater than 10 mmHg in response to sustained IHG was considered normal. Either no drop or a drop of less than 20 mmHg in SBP and/or a drop of less than 10 mmHg in DBP in response to HUT at 70 degrees tilt within 2 minutes were taken as normal. Any fall in SBP or DBP in response to HUT greater than the above-mentioned values were taken as postural or orthostatic hypotension (OH).27,28 Postural orthostatic tachycardia syndrome (POTS) was diagnosed if patients had an HR increase of 30 beats per minute (bpm) or HR above 120 bpm following the HUT in the absence of orthostatic hypotension.29 Results of CART were labeled as normal if no abnormal findings were detected, with parasympathetic dysfunction if 2 out of the 3 tests of the parasympathetic component were abnormal, with sympathetic dysfunction when 1 of the 2 tests of the sympathetic component test was abnormal, and with combined dysfunction when there is 1 abnormal test from each domain.30,31

Cardiac baroreflex sensitivity (cBRS) is used as an index to evaluate the autonomic nervous system function. A reduction in the cBRS indicates cardiac autonomic dysfunction.32,33 Cardiac BRS was calculated offline by noting the instantaneous changes in heart rate in response to spontaneous changes in arterial BP with software PRVBRS provided by FMS (The Netherlands) using cross-correlation method.34 The correlation between beat to beat systolic BP and inter-beat interval was measured in a sliding 10-s window, with delays of 0 to 5 s for interval. The program selects the delay with the greatest significant positive correlation and the slope and the delay are recorded as one BRS value. BRS readings were averaged over at least 25 min except in deep breathing, where the maneuver itself was for 1 min only.34,35 The BRS data was displayed and analyzed with dedicated Beatscope software version 1.1a. The inbuilt return-to-flow and height correction features enhanced the reliability and accuracy of Finometer recordings.36

Data were presented as mean standard deviation (SD), median with interquartile range (IQ), or number (percent) where appropriate.Distribution of the data was tested using ShapiroWilk test of normality.Comparisons between groups were done using unpaired t-test and MannWhitney U-test for normal and non-normal distributed variables, respectively. Proportions were compared using the chi-square test. Comparison of the percent changes of different study variables between groups was done using ANCOVA with the baseline value as a covariate. Data was analyzed using SPSS 28.0 software; a P-value of <0.05 was considered significant.

Fifty-nine subjects participated in this study. Both groups were matched in age (p=0.88), gender (p=0.99), and BMI (p=0.14). There were non-significant differences in the baseline heart rate (p=0.28), respiratory rate (p= 0.74), SBP (p=0.93), and DBP (p=0.66) between control and post-COVID groups. The median follow-up time of post-COVID subjects was 24 weeks (range 38 months). All subjects in both groups were vaccinated and without any comorbidities. The severity of illness among post-COVID group revealed 19 (68%) with mild and 9 (32%) with moderate acute illness based on the National Institute of Health (NIH) classification.37 (Table 1).

Table 1 Demographic and Baseline Characteristics of Study Population

Heart rate variability measurements (TP, LF, HF, LF/HF, LFnu, SDRR, RMSSD, and pRR50) were low in the post-COVID group, although statistically non-significant. Similarly, the cBRS measurements showed lower values in the post-COVID group, but did not reach a level of significance (Table 2).

Table 2 Comparison of HRV Measurements and cBRS Between Groups

Orthostatic hypotension (OH) was demonstrated in 39.3% of post-COVID-19 participants in comparison to 3.2% of the control subjects, (p<0.001). Similarly, significant abnormal blood pressure response to the handgrip test was observed in the post-COVID group compared to the controls (73.1% vs 16.1%, respectively, p <0.001). Additionally, abnormal heart-rate response to HUT was higher in the post-COVID group (35.7%) compared to 12.9% in the controls (p=0.04) (Table 3). However, none of our subjects fulfilled the postural tachycardia syndrome (POTS) diagnosis criteria.

Table 3 Comparison of Abnormal CART Results in Post-COVID Patients Compared to Control Group

Isolated sympathetic dysfunction was reported in most post-COVID participants (71.4%) compared to controls (16.1%), (p <0.001); no isolated parasympathetic dysfunction was demonstrated in either group. However, a combined autonomic dysfunction was reported in 7.1% of post-COVID patients (Table 4). Cumulatively, about 85.7% of the post-COVID patients had at least one abnormal CART test in comparison with 35.5% within the control group (p <0.001) (data not shown).

Table 4 Distribution of Sympathetic, Parasympathetic, and Combined Autonomic Dysfunction Between Groups

Both systolic and diastolic blood pressure showed a significant decrease from the baseline value after the HUT compared to the corresponding increase observed in the control group (p <0.001). Heart rate showed an increase during HUT in both groups, without significant difference (p=0.06) (Table 5).

Table 5 Comparison of % Change in Systolic Blood Pressure, Diastolic Blood Pressure, and Heart Rate During Head-Up Tilting (HUT)

In the present study, the post-COVID group showed evidence of dysautonomia indicated by sympathetic dysfunction in response to cardiovascular challenges, thus suggesting changes in the autonomic control of cardiac function. Although the baseline HRV parameters and cardiac BRS were numerically lower in post-COVID group, this did not reach statistical significance. The CARTs demonstrated altered autonomic reactivity in some tests. There was a higher incidence of orthostatic hypotension in post-COVID patients compared to controls, and there was a significantly reduced diastolic blood pressure response to isometric handgrip test. Although the post-COVID group showed significantly abnormal heart rate response to head-up tilt, none of them fulfilled the postural tachycardia syndrome (POTS) diagnosis criteria.

Autonomic dysfunction has been described following several viral infections.14 HIV infection is associated with a reduction in the heart rate variability, and several autonomic manifestations including urinary system, gastrointestinal, secretomotor, pupillomotor, sleep, and male sexual function.38 Orthostatic hypotension and urinary dysfunction have been also described in mumps.39 Varicella zoster reactivation from autonomic ganglia could cause intestinal pseudo-obstruction. Rabies could also cause excessive salivation, piloerection, and photophobia. Furthermore, autonomic dysfunction may happen in acute viral encephalitis, herpes simplex, infectious mononucleosis, rubella, and coxsackie B virus.14

Both acute and delayed neurologic manifestations have been reported after SARS-CoV-2 infection. The receptors of SARS-CoV-2 are expressed in the central nervous system. The virus could spread directly through the cribriform plate and olfactory bulb, or through trans-synaptic invasion. Encephalitis, demyelination, neuropathy, and stroke are known complications of COVID-19.40 Additionally, autonomic dysfunction has emerged as a complication of COVID-19 infection; several case reports and observational studies revealed dysautonomia in association with SARS-CoV-2 infection.15,41 Dysautonomia in COVID-19 patients may manifest as labile blood pressure, postural hypotension, bladder dysfunction, gastrointestinal dysfunction, and impotence.42 The mechanisms of COVID-19-related dysautonomia are complex. SARS-CoV-2 can cause direct autonomic tissue damage, exaggerated immune response (innate and adaptive), and inflammation.43 During the cytokine storm, sympathetic stimulation induces the release of pro-inflammatory mediators, while parasympathetic activation elicits an anti-inflammatory response. Furthermore, an association between dysautonomia and the neurotropism of SARS-CoV-2 has been reported.44

Assessment of cardiac autonomic function can be carried out by specific tests and maneuvers on the cardiac sympathovagal system. Cardiovascular reflex tests (CART) involve a group of maneuvers that test both components of ANS (sympathetic and parasympathetic) separately.10 The current study reported postural hypotension in 39.3% of the post-COVID group during the blood pressure response to head-up tilt maneuver. Additionally, abnormal blood pressure response to the handgrip test was observed in about 73.1% of post-COVID patients. These two CART components reflected an impairment of the cardiac sympathetic function. Parasympathetic cardiac activity was also affected, as 35.7% of post-COVID patients showed abnormal heart rate response to the head-up tilt procedure. However, no postural tachycardia syndrome (POTS) was found in our cohort. Similar findings were reported by a recent study that included 180 post-COVID patients. Subjects were evaluated by active stand test between 4weeks and 9months from COVID-19 onset and orthostatic hypotension (OH) was diagnosed in 13.8% of the patients; none showed postural tachycardia syndrome (POTS).17 Another recent study in young adult post-COVID patients showed sympathetic over-activity and lower values of parasympathetic activity as evaluated by HRV measurement; these changes were modulated by body mass index (BMI).45 Furthermore, a study by Marques et al revealed a reduction in HRV with increased sympathetic modulation, and a decrease in parasympathetic modulation in long COVID.46 Cardiac autonomic dysfunction has also been reported during the early stage of COVID-19 diseases. Milovanovic et al showed sympathetic dysfunction with orthostatic hypotension in about 46.3%, and abnormal handgrip tests in about 94.4% of post-COVID patients. In addition, parasympathetic dysfunction was illustrated by abnormal heart rate response to the Valsalva maneuver and deep breathing.22

HRV is a tool that is commonly used to assess sympathetic and parasympathetic modulation of the autonomic nervous system, and it is a significant marker of dysautonomia.47 HRV is composed of a low-frequency band (LF), high-frequency band (HF), and very low-frequency band (VLF). The sympathetic and parasympathetic activity of the heart is reflected by LF, and considered an indicator of sympathovagal balance. HF assesses the parasympathetic activity of the heart, reflecting the vagal-mediated modulation.12 In our study, we found a non-significant reduction in TP, LF, HF, LF/HF, LFnu, SDRR, RMSSD, and pRR50 in the COVID-19 group. In contrast, a recent study involved 50 post-acute COVID subjects 20 weeks after recovery and found a decrease in the time domain measurements (SDNN, SDANN, SDNNi, RMSSD, pNN50) and frequency domain measurements (TP, VLF, LF, HF, and HFnu) in the post-acute COVID group compared to control subjects.48 Additionally, Milovanovic et al found significantly lower results in HF, and LF in COVID-19 patients during the early phase of COVID-19 infection.22 Furthermore, another study showed orthostatic hypotension in 13.04%, and POTS in 2.17%; heart rate variability (RMSSD) was significantly lower in post-COVID-19 patients compared to healthy controls (p=0.01).21

Body mass and level of physical activity were found to affect the autonomic function of post-COVID-19 patients; higher BMI post-COVID subjects demonstrated more dysautonomia in comparison with normal BMI controls. In addition, physically inactive post-COVID participants revealed more autonomic dysfunction compared to active controls.45 These results showed that dysautonomia associated with COVID-19 is potentially influenced by level of physical activity and BMI. Since post-COVID patients in the current study had almost normal BMI, this might explain why the observed reduction in HRV was not significant.

Baroreceptor sensitivity is crucial in assessing cardiac autonomic nervous function. It is measured by analyzing the spontaneous beat-to-beat changes of arterial blood pressure and heart rate; a reduction in BRS indicates dysautonomia.32,33 In our study, we showed a non-significant decrease of baroreceptor sensitivity in the post-COVID-19 group. In contrast, another study reported a significant reduction in mean baroreceptor sensitivity during the early phase of post-COVID-19 infection.22 This difference could be attributed to the difference in the time of autonomic function evaluation of post-COVID patients; the current study evaluated the post-acute effect post-COVID infection, while Milovanovic et al studied a group of active COVID-19 infections. This is in line with the finding that dysautonomia is more obvious following the acute stage of the viral illness,39,41 and could improve in time, either spontaneously or with treatment.49 In a recent study, heart rate recovery (HRR) following exercise cessation improved significantly 6 months after COVID infection.50 In addition, many factors could affect the development of dysautonomia following COVID-19 infection, including BMI, level of physical activity,45 and degree of inflammatory response.43

Due to the cross-sectional design, it was difficult to conclude that a causal relationship exists between COVID-19 and dysautonomia. Additionally, the local restrictions of the COVID-19 pandemic made it difficult to recruit more subjects, which resulted in a relatively small sample size and may explain the non-statistically significant null findings of HRV and cBRS reported by this study. However, our results provide additional insights into the extent of cardiac autonomic dysfunction post-COVID-19 in a relatively young population.

The results of the present study are suggestive of altered cardiovascular reactivity as a post-acute sequela of COVID-19 infection, with a pronounced incidence of postural hypotension. However, this finding still needs future experimental studies with a larger sample size investigating the mechanism of ANS involvement during the active infection as well as after COVID-19 recovery.

LFnu, low frequency normalized unit; HFnu, high frequency normalized unit; TP, total power; LF, low frequency; HF, high frequency; LF/HF, low frequency/high frequency ratio; SDRR, standard deviation of RR intervals; RMSSD, root mean square of successive RR interval differences; pRR50, percentage of successive RR intervals that differ by more than 50ms; cBRS, cardiac baroreceptor sensitivity; CART, cardiovascular reflex test.

There is no funding to report.

The authors report no conflicts of interest in this work.

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41. Bosco J, Titano R. Severe Post-COVID-19 dysautonomia: a case report. BMC Infect Dis. 2022;22(1):214. doi:10.1186/s12879-022-07181-0

42. Almqvist J, Granberg T, Tzortzakakis A, et al. Neurological manifestations of coronavirus infections - a systematic review. Ann Clin Transl Neurol. 2020;7(10):20572071. doi:10.1002/acn3.51166

43. Larsen NW, Stiles LE, Miglis MG. Preparing for the long-haul: autonomic complications of COVID-19. Auton Neurosci. 2021;235(102841):3. doi:10.1016/j.autneu.2021.102841

44. Becker RC. Autonomic dysfunction in SARS-COV-2 infection acute and long-term implications COVID-19 editors page series. J Thromb Thrombolysis. 2021;52(3):692707. doi:10.1007/s11239-021-02549-6

45. Freire APCF, Lira FS, Morano A, et al. Role of Body Mass and Physical Activity in Autonomic Function Modulation on Post-COVID-19 Condition: an Observational Subanalysis of Fit-COVID Study. Int J Environ Res Public Health. 2022;19(4):2457. doi:10.3390/ijerph19042457

46. Marques KC, Silva CC, Trindade SDS, et al. Reduction of Cardiac Autonomic Modulation and Increased Sympathetic Activity by Heart Rate Variability in Patients With Long COVID. Front Cardiovasc Med. 2022;9:862001. doi:10.3389/fcvm.2022.862001

47. Electrophysiology TFotESoCtNASoP. Heart Rate Variability. Circulation. 1996;93(5):10431065.

48. Kurtolu E, Afsin A, Akta , Aktrk E, Kutlusoy E, aaar . Altered cardiac autonomic function after recovery from COVID-19. Ann Noninvasive Electrocardiol. 2022;27(1):24. doi:10.1111/anec.12916

49. Blitshteyn S, Whitelaw S. Postural orthostatic tachycardia syndrome (POTS) and other autonomic disorders after COVID-19 infection: a case series of 20 patients. Immunol Res. 2021;69(2):205211. doi:10.1007/s12026-021-09185-5

50. Cassar MP, Tunnicliffe EM, Petousi N, et al. Symptom Persistence Despite Improvement in Cardiopulmonary Health - Insights from longitudinal CMR, CPET and lung function testing post-COVID-19. E Clin Med. 2021;41(101159):20. doi:10.1016/j.eclinm.2021.101159

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Post-Acute Effect of SARS-CoV-2 Infection on the Cardiac Autonomic Fun | IJGM - Dove Medical Press

Physiology

IARI-ICAR Recruitment 2022: Check Post, Qualification and Other Details Here – StudyCafe

IARI-ICAR Recruitment 2022: Check Post, Qualification and Other Details Here

IARI-ICAR Recruitment 2022: Indian Agricultural Research Institute (ICAR) is inviting eligible candidates to attend the Online Interview for Unreserved Temporary Posts of Six SRFs under the ongoing project funded by the National Agriculture Science Fund, Indian Council of Agricultural Research, Ministry of Agriculture and Farmers Welfare, Government of India. Interested candidates should review the job description and apply using the link provided in the official notification. The applicant should have a Masters degree in relevant subjects (Plant Biotechnology/ Plant Physiology/ Plant Biochemistry/Life sciences/ Microbiology) with 4 years/ 5 years of Bachelors degree will be given preference. The last date for receipt of the Biodata is 20th October 2022.

Candidates are requested to apply for the job post before the deadline. No application shall be entertained after the stipulated time/ date. Incomplete applications and applications received after the specified time/ date shall be REJECTED. All the details regarding this job post are given in this article such as IARI-ICAR Recruitment 2022 official Notification, Age Limit, Eligibility Criteria, Pay Salary & much more.

1. The applicant should have a Masters degree in relevant subjects (Plant Biotechnology/ Plant Physiology/ Plant Biochemistry/Life sciences/ Microbiology) with 4 years/ 5 years of Bachelors degree will be given preference.

2. Desirable qualifications: Agrobacterium mediated genetic transformation of rice/soybean/mustard, genome editing of plants, molecular cloning, Molecular analysis of transgenic plants and other basic molecular techniques

Selected Candidates will be getting the salary amount of Rs.31000 + HRA per month for 1st and 2nd years and Rs.35000 + HRA per month for 3rd year.

Maximum 35 years for men for SRF positions. For women/SC/ST/OBC, age relaxation of 5 years will be given as per Govt. of India/ICAR rules.

Step 1: Go to the IARI-ICAR official website.

Step 2: Search for the IARI-ICAR Recruitment 2022 Notification here.

Step 3: Read all of the information in the notification.

Step 4: Apply and submit the application form in accordance with the mode of application specified in the official notification.

NOTE: Candidates may send their biodata with self-attested scanned copies of degree certificates, and mark sheets of 10, 12, UG and PG to [emailprotected] The last date for receipt of the Biodata is 20th October 2022.

To Read Official Notification Click Here

Disclaimer: The Recruitment Information provided above is for informational purposes only. The above Recruitment Information has been taken from the official site of the Organisation. We do not provide any Recruitment guarantee. Recruitment is to be done as per the official recruitment process of the company or organization posted the recruitment Vacancy. We dont charge any fee for providing this Job Information. Neither the Author nor Studycafe and its Affiliates accepts any liabilities for any loss or damage of any kind arising out of any information in this article nor for any actions taken in reliance thereon.

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IARI-ICAR Recruitment 2022: Check Post, Qualification and Other Details Here - StudyCafe

Physiology

We are validating old knowledge with new technology to enhance mental performance:Nimrod Mon Brokman, Behavi.. – ETHealthWorld

Shahid Akhter, editor, ETHealthworld, spoke to Nimrod Mon Brokman, Co-Founder, Behavioural Foresight, Partner at PHD (Potential Health Development) and Consultant for Indo-Israel Commerce, to find out about their approach to improving mental health by using innovative techniques.

Your views on 'Mental Health' in India I arrived in India in 2016 and started familiarizing myself with the mental health sector in Bangalore. In India, every region, and every place, is different, and there is a taboo around mental health issues. When we approached clients, they would often feel awkward and uncomfortable. Their reactions ranged from, What are you saying? Why are you speaking like that? Why are you classifying me like that?.

It took us around 2 years to build a relationship of trust with our clients regarding mental health, to make them understand that it's not a disorder that we are talking about, but rather a performance issue. When I say performance, it can be athletic, it can be at an executive level or even in our day-to-day lives how you live your life, how you conduct yourself from morning to evening - such things are by themselves contributing to your performance.

What are the risks with long term stress? Stress is a big factor in todays world. You can look at the statistics, although it often reflects as heart issue, since it's actually stress that affects the heart, causing many problems. In diabetes too, the main factor is stress or unregulated emotions. As part of the ecosystem of Connect Ventures, we decided to incorporate mental health with physical health and nutrition, to bring about a holistic solution.

We are working with different corporations on extremely innovative programs to support their employees and leaders, by bringing together Israeli technology with innovative protocols. These programs do not stop them from following their individual routines but enable them to continue with their lifestyle while improving on it. Our experience across different sectors over the years finally led to the development of EZUN - an experiential mind-simulated training, combining Israeli tech, gamification and science. Our mission is to power for excellence, by utilising minimum mental capacity for maximum mental performance through impactful gamification and fun protocols.

We are also working with the Indian military to give them the x-factor to perform and operate in the most challenging environments, in the most efficient manner.

Can gaming be beneficial and healthy for better mental capacity? After almost 4 years in India, we had gathered significant learnings from the Indian market and applied it to the way we functioned. We wanted to enable more people to enjoy our process through a lighter approach. Thats when we realised that it was important to gamify the whole process. The moment you play, you enjoy and have fun. Automatically there is less judgement, less restriction, less resistance, and thereby, way more neuroplasticity (mental adaptation). At the same time, we wanted to make it more scientific, and related to data so we had evidence that our methods were providing value to our clients.

This is how we came up with our simulation room, Ezun. Ezun in Hebrew means fundamental balance, where we train one to be able to stay constantly in balance. Balance is not stagnancy. It keeps on changing and one should be able to re-balance themselves and maintain this balance constantly during the day. This is what we have developed with EZUN. Each experiential training protocol has been designed to fit perfectly to EZUN state-of-the-art simulation training by our experts. We aim to enhance a sustainable learning experience of down and up regulation of somatic sensations and behaviours, to master the highest levels of economy over ones personal mental currency.

We have Israeli technology that allows one to assess how their physiology reacts to different stressors. Along with this stress profiling, we also use respiratory assessment to understand how the breathing functions. This is a very critical tool to change ones state of mind, as well as to observe and evaluate someone. We are also using a test to measure cortisol levels. These 3 parameters give us a stress profile to understand how someone is functioning physiologically in the day to day, and how they react naturally. With this baseline, we curate different programs. With all the programs, the person just plays computer and action games, while the data gets accumulated constantly from their physiology. Connecting these two, we can see how one functions, with the goal being, how efficiently can one function. Again, what is the economics of their behaviour, can they be efficient and spend very little to gain a lot, or are they wasting and spending a lot to gain very little.

Your vision to democratize Behavioural Foresight innovations? We are collaborating with our food division to understand how everyone can gain from the right gut and brain function. We are extending our services to educational institutes, as well as corporates and their workforce to enjoy EZUN training and our food at their facilities on the go. They can do this without changing their lifestyles, and without having to ignore their work to focus on their health. With just small changes and micro adjustments, we can create a huge impact on their day to day living.

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We are validating old knowledge with new technology to enhance mental performance:Nimrod Mon Brokman, Behavi.. - ETHealthWorld

Physiology

Sex differences in sprint running performance may be relatively small – News-Medical.Net

Conventional wisdom holds that men run 10-12 percent faster than women regardless of the distance raced. But new research suggests that the between-sex performance gap is much narrower at shorter sprint distances.

It has long been established that men outpace women by relatively large margins in mid- and longer-distance events. But speed over short distances is determined by different factors specifically, the magnitude of the ground forces athletes can apply in relation to their body mass. Women tend to be smaller than men and, all things being equal, muscular force to body mass ratios are greater in smaller individuals.

Ph.D. candidate Emily McClelland, working with Peter Weyand, the Director of SMU's Locomotor Performance Lab, quantified sex performance differences using data from sanctioned international athletic competitions such as the Olympics and World Championships. They hypothesized that these data would reveal smaller male-female performance differences at shorter distances.

An accomplished athlete and former assistant director of strength and conditioning at Bowling Green State University, McClelland has always had a natural interest in the scientific basis of human performance.

More broadly, the understanding of comparative strength, speed and endurance capabilities of male and female athletes has been a highly challenging issue for modern sport. Yet, prior to the new SMU study, quantitative understanding of sex performance differences for short sprint events had received little attention. McClelland's background, male-female differences in force/mass capabilities, and existing data trends led her to hypothesize that sex differences in sprint running performance might be relatively small and increase with distance.

Her analysis of race data from sanctioned international competitions between 2003 and 2018 supported her initial hypothesis. These data revealed that the difference between male and female performance time increased with event distance from 8.6 percent to 11 percent from shortest to longest sprint events (60 to 400 meters). Additionally, within-race analysis of each 10-meter segment of the 100-meter event revealed a more pronounced pattern across distance - sex differences increased from a low of 5.6 percent for the first segment to a high of 14.2 percent in the last segment.

Why then are women potentially less disadvantaged versus men at shorter sprint distances?

In contrast to other running species like horses and dogs, there is significant variation in body size between human males and females. If all other factors are held equal, body size differences result in muscular force to body mass ratios that are greater in relatively smaller individuals. Since sprinting velocities are directly dependent on the mass-specific forces runners can apply during the foot-to-ground contact phase of the stride, greater force/mass ratios of smaller individuals provide a theoretical relative advantage. Additionally, the shorter legs of a female runner may confer the advantage of more steps and pushing cycles per unit time during the acceleration phase of a race. These factors offset the advantages of males (longer legs and greater muscularity) that become more influential over longer distances.

Consider the example of Shelly-Ann Fraser Pryce, a Jamaican track and field star who is 5'0" tall, 115 pounds, and who holds two Olympic and five World Championship gold medals in her signature 100-meter event. Her time at the 40-yard mark of a 100-meter race has been estimated to be as brief as 4.51 seconds-;a time faster than nearly half of all the wide receivers and running backs that tested in the National Football League's Scouting Combine in 2022. In contrast to Shelly-Ann Fraser-Pryce, most of these aspiring NFL football players are over 6' tall and 200 pounds.

The research study "Sex differences in human running performance: Smaller gaps at shorter distances?," was conducted by McClelland and Weyand and has been published in the Journal of Applied Physiology.

Source:

Journal reference:

McClelland, E.L., et al. (2022) Sex differences in human running performance: smaller gaps at shorter distances?. Journal of Applied Physiology. doi.org/10.1152/japplphysiol.00359.2022.

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Sex differences in sprint running performance may be relatively small - News-Medical.Net

Physiology

Limbo is tackling obesity with a pair of wearables and decades of physiology – TechCrunch

In recent years there has been a flurry of startup activity aimed at commercializing blood glucose biosensors aka, wearable tech that was originally developed for diabetes management. These continuous glucose monitors (CGMs) transmit near real-time data on glucose levels, providing instant feedback (via a companion mobile app) on how the body metabolizes different foods or responds to lifestyle decisions around exercise and sleep.

The biowearables, which are semi-invasive typically worn on the arm with a sensing filament inserted just under the skin were originally developed for diabetics and pre-diabetics who have a medical need to track their blood sugar because of insulin resistance. But the startup gambit is that opening access to CGMs more generally can offer broad health utility by giving all sorts of people a dynamic window onto whats going on with their metabolism.

Some of these startups are selling the idea that biohacking by tracking blood glucose can help people optimize athletic performance, or configure a healthy diet and lifestyle including weight management. But the startup strategy has often fixed on opening up the data window first as a tactic to build product utility while they acquire (and structure) users metabolic and lifestyle data tracking glucose responses to food and lifestyle inputs and, they hope, spotting positive and negative patterns that they can use to synthesize a fitness or healthy lifestyle program.

Limbo, a New York, London and Cork-based startup which is announcing a $6 million seed raise today, is in this growing pack commercializing CGM tech in its case building a subscription weight management business to target the obesity crisis. But it claims to be bringing a distinct approach with a product thats not just a data-mining work in progress; rather, they say, the program is based on some three decades of research undertaken by one of the co-founders chief research officer, Tony Martin, who is a physiologist and coach.

[Martin] essentially worked out the secret of how blood glucose regulated the body and how energy in the body is mediated through blood glucose, says co-founder and CEO, Rurik Bradbury, discussing the startup in a call with TechCrunch. How if you control it in a certain way then you can have very dramatic weight loss results based on biodata.

Martin is not affiliated with any research institutions, nor has he published any scientific papers on his work so its private research and results he was able to obtain using this private methodology with his own clients that Limbo is drawing on for its product.

The big breakthrough came over the last 5-6 years when CGMs came out which allowed him to test a number of hypotheses, explains Bradbury. Both on himself and on his weight loss clients. And what he found was a number of patterns and a number of effects which he could replicate to do with the balance of different macronutrients essentially, and how the body can regulate itself if you reduce carbs and sugars.

Theres nothing hugely secret about that about whats essentially a Keto[ogenic diet] type program. There are many, many different variants of it and what he did was work out the right balance for people on a more individualized basis so it could be implemented as a program with a CGM to steer them in real time.

Now weve got kind of the recipe for how to make this work for people as a platform as opposed to a person by person system, he adds.

Limbos other co-founder Pat Phelan, whose name may be familiar to long-time TechCrunch readers as he exited his ecommerce fraud protection startup Trustev to TransUnion for $44 million back in 2015 has also put himself through the program.

Indeed, the inspiration for Limbo began with Phelans personal weight loss journey after years of jetsetting startup life had not been kind to his health. And it was in looking for help to address his obesity problem that he met Martin who suggested he try his homebrew blood glucose tracking method with a CGMv and then Phelans success with the regime (which he discusses in this video on the startups website) led to the trio of founders coming together to establish a startup to productize Martins program (with Phelan and Bradbury bringing the tech experience gleaned from years working in startups).

Limbo was founded in fall 2020 so its very much a pandemic health tech startup, with the first private beta users starting on the program at the end of 2020.

Target users are people looking to lose 10-15% of their body weight, per Bradbury. While typical customers so far are 35-55 in age range.

The team doesnt have any efficacy studies published quantifying the impact of the weight loss program by, for example, comparing Martins method to other weight management approaches. But Bradbury argues early results speak for themselves with members seeing an average weigh loss of 12% after three months of use. (Phelan himself lost 36kg/81 pounds over 9 months using the prototype.)

The 12% stat was based on an initial paying cohort of 50 users. Limbo now has around 2,000, per Bradbury, who says theyre hoping to have tens of thousand signed up over the coming 12 months.

The program is a subscription service costing 1,500 for three months access, so its definitely premium level pricing.

As well as a supply of CGM sensors to track their blood glucose, Limbo members are sent two additional devices: A wearable wristband that tracks a range of health data (including heart rate, steps, skin and body temperature, blood oxygen); and a smart scale which can measure body fat and muscle mass in different areas of the body so its triangulating a range of signals in order to assess the healthiness (or otherwise) of the users diet and lifestyle; and to track their progress towards their weight goals.

We started with an off the shelf piece of tech [for the wristband]. But we have a customized one built to our specs, says Bradbury, discussing its hardware mix. We have the person who used to run Apple in Asia Rory Sexton on our board, and he was one of the first investors. And he became interested because youve probably seen the rumors that Apple is looking to add blood glucose to [Apple] Watches. But its a very tricky thing. Weve also looked at this ourselves. And theres lot of constraints there as far as how much power it would take and how accurate it is I think it might be a little way off.

But he got interested in that and we did an Apple Watch integration but the challenge with that and all the other tools out there Fitbit and so on is that their data resolutions quite low. So [with our custom hardware] were looking every second or minute at these data points. [Whereas] Apple Watch and other wristbands tend to sample every few minutes to save power because the battery life is tricky.

Limbos smart scale is also customized rather than off-the-shelf kit and Bradbury says it is higher end than consumer smart scales (which can suffer from poor accuracy). But he also says there is less need for high resolution data for the scale (vs the wristband) since its mostly used to track progress over time, not for dynamic feedback on meals etc.

Were looking at a gradual over the course of 3-6 months period of shifting body fat percentage, he says of the scale. Obviously that usually comes down. Thats the main goal of the program. So were looking for a shift over time. Were not looking for a precise, exact moment in time measurements. Were not training, say, boxers for a fight where every ounce counts.

The core interface for Limbos program is of course a mobile app which visualizes the users blood glucose level (via a plotted line), tracking changes continuously; and delivers feedback and nudges to members (via push messages).

Limbo says its using a combination of AI-powered analysis and human coaches looking at users data in order to encourage positive behavioural changes, via feedback and nudges with the overarching goal of steering users towards eating a healthier, balanced diet and away from consuming foods that spike their blood sugar. So the push is to cut back on simple sugars (carbs, processed foods etc).

The user has to do only limited data logging themselves. Theyre asked to snap a picture of whatever theyre eating to log their food intake, with an optional text field to add more details. But Bradbury says adding extra detail isnt required because all the connected hardware enables them to rely on this tracking of the users biological signals to determine what post-meal feedback to provide.

So while the app might not literally know what that dark beverage youre drinking is or, if it looks like a cup of tea, how many sugars you might have slipped into it the data wont lie. If the drink contains unhealthy levels of sugar that spike your glucose the app will pick up that response in the CGM data and nudge you to drink something less sugary next time.

So the user gets continual, dynamic feedback to help them change their diet for the better.

Its a really interesting issue because its both psychological and its data, says Bradbury, discussing the importance of the psychological element. You can show people data you can tell them stuff til youre blue in the face but thats different from having a psychological effect to make them behave in a different way. So the nudges are almost like extra pushes on top of the data. So if someone spikes their blood sugar itll push a message saying what just happened? Essentially you cant cheat on this program.

One of the biggest issues with other diets is compliance. That people quote forget they had that muffin. And no ones the wiser except for them. Whereas you cant cheat on Limbo. Theres automated sensing if something happened. So theres interventions like that where the member knows theyre being watched and they behave accordingly. You cant pull a fast one and sneak something past the system. And secondly there are educational interventions such as the right balance of carbs and sugars and proteins and fats to eat to get to your goal.

So that might be this contained too many carbs, try to reduce sugar content in drinks, that type of thing. Another one might be more positive: Add more protein to the next meal or do something along those lines.

The idea is a coach on your arm that watches you 24/7 and steers you in the right direction, he adds.

But dont we already know that eating sugary processed foods is bad and leads to weight gain, and eating healthy whole, fresh foods is good for us? Why do we need an app to tell us this?

If knowledge were enough to get someone across the finish line we all know these things technically then there wouldnt be an obesity crisis. But the hard thing is that firstly a lot of people dont know exactly what carbs and sugars are and the impact of highly processed foods which are extremely bioavailable which spike you very quickly and directly after eating them. So theres a lot of people who dont really have a clear picture of what food does to them, he suggests.

Secondly weve been served myths for decades or centuries. People think that a sweet piece of fruit is good for you theyve been told its good for you. And theyve taken it for granted. When a glass of orange juice is a cup of sugar. So these pervasive myths throw people off course. And certainly its the willpower thing if you have a coach whos watching you 24/7, whos holding you accountable, steering you in the right direction, educating you on whats actually happening to you inside your body its a very powerful crutch to help people get places.

While the primary focus of Limbos intervention currently is around food, nutrition and diet, Bradbury notes the app will also nudge users to take some low intensity exercise such as a post meal walk as another tactic to flatten the curve (aka get glucose level back into the target zone). And he says theyre planning to put more focus on how activity affects blood glucose as they continue developing the product.

If you eat something that has too high carb and sugar content the app will often pop up and say now would be a good time to take a [low intensity exercise] walk so its not about sending people to the gym and spin class and so on. Its much more about a smaller, more manageable amounts of exercise that complement the food choices, he says of the current Limbo experience.

One of the big lies that have been sold to people is that you have to go to the gym and sweat your way out of extra weight. Its very, very hard to exercise off a poor diet, he adds. Or an imbalance of energy coming into the body that is expended. So most of the nudges are about food and diet.

The priority for the seed funding is product development. We havent really spent any money on marketing and weve let things spread by word of mouth because I think people are quite mistrustful of marketing for anything to do with diets and food its a space where theres so much snake oil sold and dodgy businesses so were basically just showcasing what people have done or the weight theyve lost with this and having them spread the word themselves, he tells us.

So rather than spend lots of money on marketing were putting that into the AI, the analytics and the product side so were building out teams to make the product broader. Theres lots of things we can do more on in terms of sleep and exercise. Lots of the focus is on food but they all interact with each other so were building out an experience to showcase to members how those things interact in a visual way.

Limbo is also working towards a U.S. launch in the second half of next year, per Bradbury.

Obesity is of course a global problem so the team sees huge potential for scaling, while cautioning that they dont want to grow so quickly they lose the quality of individualized advice, as Bradbury puts it. (For a sense of scale, Limbos team is currently 18 people who are supporting around 2k members.)

On the competition front, while there are a growing number of CGM players seeking to tempt consumers with a glimpse of their metabolic health indeed, even CGM maker Abbott is itself getting into the game Bradbury argues Limbos approach of productizing an existing weight loss program as an app (rather than trying to develop a methodology off of CGM data) gives it an edge.

Hence he also argues that Limbos competition is closer to a more radical obesity intervention like gastric bypass surgery than what other startups are offering.

That said, U.S. startup January AI also has a lot of research underpinning its food-response focused program, while Indias Healthify which is due to launch a premium CGM offering in the U.S. next year already has years of fitness data under its belt (and the latters Pro offering similarly combines CGM, smart scale plus in-app coaching), to name two. So Limbo certainly isnt the only solid-looking CGM weight loss game in town.

Asked about its pricing strategy which is a major mark-up on most CGM competitors Bradbury again says its a reflection of the proven program and accessible approach its offering.

As far as weve seen so far all of the other companies started with the idea of well what if we could give CGMs to everyone? And then well look at the data and see what we can find, he says. So we took the opposite approach Weve already done the 30 years research beforehand so we know what happens when someone wears a CGM, we know how to steer them into better choices.

So while we look similar to some other CGM companies were starting from a very different position. Were implementing a pre-existing, prescriptive program do this, do that, do this, and you will lose weight. So thats a very big difference in terms of the experience of the program and people will, I think, pay for results.

Aside from premium pricing, there is the challenge of convincing users to stick a sensor in their arm. Wearing a CGM can look daunting, given its a semi-invasive sensor that requires both pricking your skin and living with a filament in your arm for weeks at a time, but Bradbury says the team hasnt so far had a problem getting people to get comfy with biowearables.

He suggests target customers are simply so motivated to achieve their weight loss goals and so tired of trying diets that are miserable and havent helped them that theyre happy to try something different where they get to see data and track their results, even if it means getting comfortable with firing a gadget into their arm every two weeks.

Still, the first 2,000 or so Limbo members may be especially motivated due to repeat failure to shift weight other ways. So it will be interesting to see whether its early adopters are outliers in being so easy for it to onboard, i.e. owing to having stubborn weight issues and whether broader scaling will be more challenging.

Limbos price-point is certainly one hard limit.

On the other hand, the lure of real-time health data is undoubtedly powerful and if its method of bite-sized insights plus wraparound support which does the hard work by translating sometimes confusing metabolic signals into simple actions people can take to improve their lifestyles then its easy to imagine big appetite for a smart but simple diet tool.

A lot of people start the program and its not for 3-4 weeks that their blood sugar ever gets into the standard zone and thats because for the 10-15 years prior they were eating carbs and sugars so often and so much that their body systems were beaten down and overwhelmed and they were constantly fighting to lower the sugar but with insulin resistance and so on they couldnt do it, says Bradbury of Limbos experience with early members. But after 3-4 weeks with an intense [effort] in pushing youll find that that member gets into the blue for the first time.

What the system really is is letting people conscientiously engage with their bodies and thats something thats almost impossible with food because you cant just put your finger on your pulse and measure your blood glucose So if we can visualize this for people and coach them on what they see it can have a big effect.

Its a virtuous cycle we try to set up for them, he adds. Youll see a bad result if you have a[n unhealthy] snack and then youll know thats going to happen. So, over time, people unwind those snacking habits. Its also the effect of them seeing what is happening inside their body. You can eat a cookie or a muffin or something and you can ignore it. But when you see it in front of you in the app this spike happening and the crash afterwards its a very different thing [vs the traditional experience of dieting] in terms of a feedback cycle, a feedback loop to change your decision next time.

Limbos seed round is led by Hoxton Ventures. Other backers include (the former NBA basketball player) Shaquille ONeal, Seedcamp, (former Apple exec) Rory Sexton, (rugby player) Jamie Heaslip, and co-founders at a number of tech firms including Intercom, PCH International, Yelp, Voxpro, and Web Summit.

This report was updated with a correction: We originally misstated the price of Limbos plan its 1,500 for three months, not 1,300 as we originally reported

See more here:
Limbo is tackling obesity with a pair of wearables and decades of physiology - TechCrunch

Physiology

Integrative Physiology | University of Colorado Boulder

At the Department of Integrative Physiology we study organisms as functioning systems of molecules, cells, tissues, and organs. This emphasis on whole-body function, and its applications to human health and disease, has made Integrative Physiology the largest undergraduate major at CU-Boulder. Our PhD program was recently ranked 9th out of 63 physiology programs in the country. Our diverse faculty include several who have joint affiliations with the Institute for Behavioral Genetics and the Center for Neuroscience, as well as clinical divisions at the CU-Anschutz medical campus.

For a video introduction to the Department and our mission/vision and diversity statements, see the About Us page.

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Integrative Physiology | University of Colorado Boulder

Physiology

From Africa to the Roman Empire: New Study Reveals 7,000 Years of Donkey Domestication – Horse Network

Be they ever so humble, theres no creature quite like the donkey.

Though these hairy, hardy decedents of the Equidae family are often thought of as the horses slightly quirky cousins from Albuquerque, they have earned their place as our counterparts in civilizationfrom their role in Biblical tales to modern DreamWorks classics (hello,Shrek!).

As turns out, though, donkeys may be far more than that. And thanks to new research from the University of Florida, we now know humans wouldnt have gotten very far without them. Literally.

Donkeys have been important to humans for thousands of years, being the primary source of work and transport for many cultures. Unlike horses, little was known about the origin and domestication of donkeys, the study says. Understanding their genetic makeup is not only key to assessing their contribution to human history but also to improving their local management in the future.

To that end, a global team of 49 researchers managed to sequence the genome of the donkey from multiple regions around the world, comparing the makeup of more than 200 modern and more than 30 ancient donkeys, along with 15 wild horses.

Using both DNA analysis and fossilized remains, the team discovered that donkeys were likely first domesticated around 5000 BCE in Africa by herding peoples, spurred by the large-scale aridification of the Sahara Desert. This is in direct contrast to horses, which were actually domesticated by humans on two occasions after the first try failed. (We assume early man was attempting to work exclusively with small ponies at the time).

Domestication is a really neat natural experiment, said Samantha Brooks, an associate professor of equine physiology at the University of Florida. How we use animals in our day-to-day lives changes the physiology of these animals. Watching this across thousands of years of genetic history was really fascinating. These changes illustrate how the unique physiology of the domesticated donkey gave them the tools needed to survive and thrive as they worked and lived alongside humans.

Whats more, by understanding the movement of donkeys throughout history, the study also reflects human movement and activities, including the transport of goods, animal husbandry methods, and how donkeys were selected for unique traits to pass down. A primary example: A group of donkey genomes pulled from the remains of a Roman settlement in Boinville-en-Wovre, in northeastern France, which showed that donkeys in that region may have been selectively bred to produce certain coat colors, including dun.

This is an exception from the rest of Roman France, however, where mules were the dominant animal species used. According to the study,during this period,the Romans may have imported additional, larger-stature donkeys from Western Africa to breed mules of greater size, which they could then use to fuel transportation networks throughout the Empire.

Donkeys have fueled human agriculture throughout early history, and they continue to do so across the globe, especially in developing nations, Brooks explained. Donkeys are extremely hearty animals, theyre real survivors, and were excited to learn more about the adaptations [that] gave them what it takes to survive.

And, according to Brooks, the evolutionary trajectory of the donkey may also hold the key to thriving in our own, quickly changing world. A better understanding of how [donkeys] got their toughness [teaches] us a lot about animal physiology and gives us new ideas on what it might take to adapt our livestock populations to survive in a warming climate, she said.

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From Africa to the Roman Empire: New Study Reveals 7,000 Years of Donkey Domestication - Horse Network

Physiology

Examining stress and the human body – News Center – The University of Texas at Arlington – uta.edu

Friday, Sep 23, 2022 Neph Rivera : Contact

Ashley Darling (left) and Jody Greaney

Youre stuck in traffic. Youve spilled coffee on yourself. Youve forgotten your phone at home.

These may seem like small annoyances by themselves. But the stress they can cause on the body has the potential to accumulate. A team of University of Texas at Arlington researchers is exploring how those day-to-day stresses of life may impact ones health.

Ashley Darling, doctoral student and graduate research assistant at UTAs Neurovascular Physiology Laboratory, under the supervision of Jody Greaney, assistant professor of kinesiology and lab director, is studying how daily stress can play a role in ones risk of cardiovascular disease.

Daily stress is universally experienced. Its part of life and elicits an emotional response. Typically, people get into a worse mood as a result of these daily stressors, Darling said. What weve seen is that a greater increase in negative mood is correlated with biological outcomes that may lead to an increased risk of future cardiovascular disease.

Darlings project is The moderating influence of physical activity on the link between daily stress vulnerability and blood pressure reactivity. It received grant funding from the American College of Sports Medicine Foundation.

Darling said stress activates the sympathetic nervous system, which drives the bodys fight or flight response. With that activation comes an increase in blood pressure and heart rate. The blood pressure spike from that acute stress previously has been linked to a higher risk of cardiovascular disease.

But Darling says there is a way to fight back: by being active. She and her team are investigating whether physical activity can help lower the bodys reaction to acute stress, thereby decreasing the bodys disease risk.

We are always interested in physical activity and sedentary time. It is such an accessible and very powerful intervention, Darling said. Trying to understand how public health initiatives could be created to promote exercise went into the decision to pursue this study.

Participants will wear a small accelerometer on their hip for a week that will record their physical activity and sedentary time. They will also document their exposure to daily stress and their emotional response to that stress. On the studys final day, participants will visit the lab and undergo exposure to acute laboratory-applied stressful tasks, like submerging their hand in a bucket of ice water, to see how their blood pressure levels react.

Darling said she is grateful for research experience at UTA and the mentorship of Greaney.

I moved here from Virginia specifically for UTA and to work with Jody, just because I think the University really does offer a great amount of resources, Darling said. The department and the people whom I am able to work with give me a unique set of skills that I cant really get from other places.

Greaney said that Darlings research approach is unique.

Very few investigators are working at merging psychology and psychological-related outcomes with physiology, Greaney said. Ashley has done a really nice job of building a team of investigators that is going to help her be successful in completing this study.

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Examining stress and the human body - News Center - The University of Texas at Arlington - uta.edu

Physiology

Study sheds light on how heat stress affects kidney function – News-Medical.Net

Acute kidney injury-; defined as an abrupt decline in glomerular filtration rate (GFR)-;is among the top causes of hospitalization during a heat wave. New research published ahead of print in the American Journal of Physiology-Regulatory, Integrative and Comparative Physiology sheds light on how heat stress affects kidney function. The study was chosen as an APSselect article for September.

The findings of the present study support that GFR reserve is utilized to maintain GFR during mild passive heat stress in young healthy adults.

Under normal conditions, the kidneys have a reserve of untapped function they can draw on in the event of greater physiological need. The capacity to increase function is called the GFR reserve. One way to study GFR reserve is to monitor levels of a waste product called creatinine for a few hours after eating a high-protein meal.

For the current study, 16 healthy adults completed two versions of such a trial, one under normal heat conditions and the other under mild heat stress. After collecting baseline readings of kidney function, researchers gave each participant a whey protein shake and monitored them for two and a half hours.

The research team found that creatinine levels were elevated after drinking the shake in the normal temperature trial but not in the heat stress trial. This indicates that the participants' kidneys were not able to increase their filtration rate to the same degree when faced with mild heat stress as they did at a normal temperature. They likely used their reserve to maintain a reduced degree of function.

This study sheds light on a likely mechanism for the increase in kidney injury during heat waves. The authors note that those known to be at greater risk for kidney damage during heat waves tend to also be populations known to have reduced GFR reserves, such as older adults.

Source:

Journal reference:

Freemas, J.A., et al. (2022) Glomerular filtration rate reserve is reduced during mild passive heat stress in healthy young adults. American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. doi.org/10.1152/ajpregu.00090.2022.

Link:
Study sheds light on how heat stress affects kidney function - News-Medical.Net

Physiology

Breakthrough prize recognizes discovery at MBL of new organizing principle in cells – EurekAlert

image:Clifford Brangwynne at the Marine Biological Laboratory (MBL) in Woods Hole, Mass., on August 2 2022. Brangwynne and Anthony Hyman made the initial dsicovery of condensate formation in the MBL Physiology course in 2008. They have received the 2023 Breakthrough Prize in Life Sciences for this research. view more

Credit: Dee Sullivan

WOODS HOLE, Mass. The discovery of a fundamental way for cells to organize internally, first recognized in the 2008 Physiology course at the Marine Biological Laboratory (MBL), has been honored by the Breakthrough Prize in Life Sciences awarded to Anthony Hyman and Clifford Brangwynne, then instructors in the course.

The Breakthrough Prize, renowned as the Oscars of Science, are presented annually in the fields of life sciences, fundamental physics, and mathematics to recognize the worlds top scientists working in the fundamental sciences the disciplines that ask the biggest questions and find the deepest explanations. Laureates receive a $3 million prize and are honored at a globally broadcast awards ceremony (date to be announced).

Brangwynne, Hyman, MBL Physiology course students, and colleagues solved a longstanding mystery of how cells create order in the millions of molecules that zip around within their boundaries. As they observed in nematode worms in the course, and later confirmed as a general principle, cells spontaneously form liquid-like droplets that concentrate some molecules in a membrane-free drop, while excluding others. These condensates, which usually contain protein and RNA, form by a phase separation process, similar to water vapor condensing into dew.

This observation ended up having major reverberations. Since 2008, evidence has mounted that condensates regulate many critical cellular processes, from cell division to gene expression, and are involved in the development of diseases that include cancer, neurodegenerative disease, Covid-19, and others. Several biotech companies have formed to pursue medical applications of condensate research.

The MBL is the birthplace of this field, because so much happened here, Brangwynne says, including foundational discoveries that issued from a collaborative, five-year initiative at the MBL (2013-2017) funded by the Howard Hughes Medical Institute. (See timeline of phase separation discovery research at MBL here.)

The discovery of biomolecular condensates has fundamentally changed how we think about cellular processes and disease, said MBL Director Nipam Patel. It is a tribute to the tremendous value of the MBLs education and training programs that the original observation was in the Physiology course, and that in the decade to follow, many scientists associated with the MBL vastly extended the observation and pioneered a new field of study.

The Breakthrough Prize was founded in 2013 by Sergey Brin, Priscilla Chan and Mark Zuckerberg, Yuri and Julia Milner, and Anne Wojcicki.

The laureates honored today embody the remarkable power of fundamental science, said Yuri Milner, both to reveal deep truths about the Universe, and to improve human lives.

The 2023 laureates have produced absolutely stellar science, said Wojcicki. The creativity, ingenuity and sheer perseverance that went into this work is awe-inspiring.

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The Marine Biological Laboratory (MBL) is dedicated to scientific discovery exploring fundamental biology, understanding marine biodiversity and the environment, and informing the human condition through research and education. Founded in Woods Hole, Massachusetts in 1888, the MBL is a private, nonprofit institution and an affiliate of the University of Chicago.

Other resources:

Clifford Brangwynnes Friday Evening Lecture at MBL (2021)

Brangwynnes Research at the MBL, Summer of 2022

Description of the Original Discovery in the Physiology course

MBL Press Release on Physiology Course Discovery (2009)

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.

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Breakthrough prize recognizes discovery at MBL of new organizing principle in cells - EurekAlert