Category Archives: Physiology

Physiology

Study suggests that hormone seasonality in humans may have a physiological peak season for biological functions – EdexLive

A recent study has provided researchers with a dataset of millions of hormone tests from medical records that shows seasonality with a winter-spring peak in hormones for reproduction, growth, metabolism, and stress adaptation. The hormone seasonality indicates that, like other animals, humans may have a physiological peak season for basic biological functions.

Uri Alon and colleagues analysed the results of hormone blood tests between 2002 and 2017 from nearly 3.5 million adults aged 20 to 80 years and living in Israel. Data were sourced from the medical database of the Israeli health-service Clalit. The test results revealed that human hormones exhibit patterns of seasonality. Effector hormones peaked between winter and spring. However, most upstream-regulating pituitary hormones for growth, reproduction, and stress peaked in late summer.

The delay of pituitary hormones was unexpected, given that hormone circuit delays typically last hours rather than months. The authors also determined that adrenal and pituitary gland masses grow within months due to hormones' trophic effects, which produce a feedback circuit with a natural annual frequency. The findings suggest that hormone seasonality in humans may have a physiological peak season for biological functions, according to the authors.

The specific seasonal phases of the hormones were used to suggest a model for a circannual clock in humans and animals that can keep track of the seasons, similar in spirit to the circadian clock that keeps track of the time of day.

Hormones control the major biological functions of the stress response, growth, metabolism, and reproduction. In animals, these hormones show pronounced seasonality, with different set-points for different seasons. In humans, the seasonality of these hormones remains unclear, due to a lack of datasets large enough to discern common patterns and cover all hormones. The study analyzes an Israeli health record on 46 million person-years, including millions of hormone blood tests.

Clear seasonal patterns were found, the effector hormones peak in winter-spring, whereas most of their upstream regulating pituitary hormones peak only months later, in summer. This delay of months is unexpected because known delays in the hormone circuits last for hours.

This study explains the precise delays and amplitudes by proposing and testing a mechanism for the circannual clock: The gland masses grow with a timescale of months due to trophic effects of the hormones, generating a feedback circuit with a natural frequency of about a year that can entrain to the seasons. Thus, humans may show coordinated seasonal set-points with a winter-spring peak in the growth, stress, metabolism, and reproduction axes.

Major biological functions in mammals, like growth, reproduction, metabolism, and stress adaptation are controlled by dedicated hormonal axes. In each axis, signals from the hypothalamus cause secretion of specific pituitary hormones into the bloodstream. The pituitary hormones instruct a peripheral organ to secrete effector hormones with widespread effects on many tissues.

For example, the stress response is governed by the hypothalamic-pituitary-adrenal (HPA) axis: Physiological and psychological stress signals cause the hypothalamus to induce secretion of ACTH from the pituitary, which instructs the adrenal cortex to secrete cortisol. These axes act to maintain physiological set points. The setpoints can change to adapt to different situations, a concept known as rheostasis.

Animals show seasonal changes in the pituitary and effector hormones that govern seasonality in reproduction, activity, growth, pigmentation, morphology, and migration. This adaptive physiology includes changes in body composition, organ size, and function. In general, hormone seasonality is thought to be a dominant regulator of physiological and behavioural traits in animals.

Animals show these changes with a circannual rhythm even when maintained in constant photoperiod and temperature conditions. They cycle without external signals, by means of an internal oscillator with a period of about, but not exactly, 1 y. The mechanism and physiological location of this circannual clock is a subject of current research. A key component is the pars tuberalis in the pituitary stalk, whose thyrotrophin cells oscillate between high and low states of hormone production. This area receives input on photoperiod from melatonin signals.

Whether hormones show seasonality in humans has not been studied comprehensively by tracking many hormones in a large number of participants. Each axis has been studied separately, usually with small samples. These studies suggest that thyroid hormones and cortisol show a seasonal variation on the order of 10%. The studies are limited by considerations of circadian rhythms which affect cortisol and other hormones.

To study human hormone seasonality requires a large dataset with comprehensive coverage of all hormones. Such a study was provided using an Israeli medical record database with millions of blood tests. It addresses the circadian rhythm concern using the time of each test and found coordinated seasonality with a winter/spring peak in effector hormones and surprising antiphase between pituitary and effector hormones.

It provides an explanation for this antiphase by showing that trophic effects of the hormones create a circuit in which the functional masses of the glands changes over the year and can entrain to yearly signals. The results support a winter-spring peak for human reproduction, metabolism, growth, and stress adaptation.

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Study suggests that hormone seasonality in humans may have a physiological peak season for biological functions - EdexLive

Physiology

Wellbeing webinar: improved brain function via meditation – Epigram

By Emma Hanson, English Literature MA

The Croft Magazine // In the final webinar of Transcendental Meditation Societys 360 Degree Wellbeing series, Emma learned about the benefits of transcendental meditation from Gaetano Arena and James Miles.

Gaetano Arena is a PhD student at the University of Bristol who set up the 360 Wellbeing series. I asked him about the impact that it has had on his life:

I learnt transcendental meditation (TM) a couple of years ago when, at the end of my PhD in Aerospace Engineering, I was really struggling with my own mental health. It was very hard to concentrate and write my dissertation, and my mood and energy levels were always incredibly low. I thought that it was only stress and some personal issues that were causing this sudden drop in my motivation and enjoyment of life.

I felt some of the benefits of TM just days after I had tried my first meditation. I was feeling more and more energetic and happy each day, but the main benefit I noticed was that I became much more aware of my physiology and its connection to my mind. I could notice almost immediately the effect food and sleep had on my mood and energy level.

Likewise, I could feel how introducing yoga and a more regular workout routine had a massive impact on my mental health. Basically, the meditation practice removed deep layers of stress that prevented me from realising what was causing the issues with my own physiology and mental health.

TM is a very simple technique, best done twice a day for 20 minutes in the morning and evening. It is a meditation technique that uses a mantra to go beyond the thinking process and reach a fourth state of consciousness to transcend thoughts and in this way reach a state of peace and rest.

Maharishi Mahesh Yogi introduced this technique to the Western world in the 1950s and it has since been practised by celebrities such as Jerry Seinfeld and Hugh Jackman. Celebrities are fans of it, but what makes transcendental meditation is its simplicity.

So how do you actually do it? As I said before, TM is a type of mantra meditation. You simply close your eyes and chant a mantra. Mantras can be found by searching transcendental meditation mantras on YouTube, and you can find one that works for you. There is also a free app called 1 Giant Mind, which offers a guided introduction to TM meditation, and the option to do a 30-day challenge.

TM allows you to reset yourself. It makes us more efficient, stops us procrastinating (the dream!), and gives us the ability to focus more sharply by developing our full mental potential.

Patrice Gladwin, a transcendental meditation teacher, attested to the benefits of TM, commenting: I love teaching TM as it makes life so much more joyful and stronger than life without it.

Gaetano talked about why he felt the need to set up this wellbeing series and educate students about various aspects of wellbeing:

I was shocked when I read the studies and annual reports on the wellbeing and mental health of UoB students. Therefore, I submitted a proposal to the UoB Alumni Grant Award, asking to sponsor the university's TM Society for the organisation of wellbeing courses that I could exploit to spread the awareness of TM and several healthy habits among university students. The grant was eventually assigned, and, with the help of the TM national organisation, I have organised the 360 Wellbeing Webinar. I am really grateful to the UoB Alumni Group for the support.

At the start of the first session, James Miles talked about the importance of our wellbeing, summarising the importance of the techniques learnt over the course of this webinar series.

We all want more energy, we want to be creative, we want full use of our brain functioning, we want to be successful, happy, and reduce stress. Most of all we want to enjoy life. And we must remember that we can achieve this because our wellbeing is in our own hands.

Even if you missed the 360 Wellbeing webinar series, you can easily access information about the techniques discussed by reading my other articles on sleep hygiene, the benefits of yoga and how Ayurveda can support wellbeing. As James Miles concisely says, your wellbeing is in your own hands, and the benefits of these four practices have the potential to transform your university experience.

Featured image: Epigram / Robin Ireland

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Wellbeing webinar: improved brain function via meditation - Epigram

Physiology

Study Finds MediPines’ Breakthrough Non-invasive Gas Exchange Method Highly Precise: Ideal for Covid Response – PRNewswire

Using the MediPines AGM100, a respiratory medical device,researchers were able to demonstrate that the new breath-based measurement of gas exchange efficiency has very low variability and is highly correlated with established blood-sampling methods.

In the new non-invasive method of measuring gas exchange efficiency, concerns of variability in expired breath samples have been addressed.The variability of gas concentrations throughout the respiratory cycle can range dramatically; however, when steady state end-tidal gas samples are used, gas concentration is remarkably constant.Thecurrent study found the very lowvariability of end tidalgasmeasurementswithin subjectsof1.3%or 1.4 mmHg for oxygen and 1.8% or 0.7 mmHg for carbon dioxide.The traditional method (Riley Method) does not directly measure the lung alveolar gas level but estimates the alveolar level from a calculation that uses arterial blood gas values and a number of assumptions.

In the age of respiratory diseases like Covid-19, where stability and repeatability of patient measurements matter, this study's conclusion is a breakthrough finding for quicker, non-invasive methods that are ideally suited for the hospital. A breath-based gas exchange analysis using the AGM100 is easy to obtain for both practitioner and patient. The gas exchange analysis provided by the AGM100 requires the patient to simply breath into a mouthpiece and can be completed within two minutes.

"This study demonstrates the merits of a breath-sampling based approach, given the low variability, which allows for high reproducibility and reliability in clinical practice. This is consistent with our previous study that demonstrated a very high correlation and low measurement bias of directly measured arterial PO2, with that estimated non-invasively from the AGM100 in a range of different physiological states," said Dr. Phil Ainslie,Canada Research Chair and Co-Director of the Centre for Heart lung and Vascular Health, School of Health and Exercise Sciences at theUniversity of British Columbia.

This finding further supports a clinical validation study published in 2020 by researchers from the University of British Columbia and Duke University Medical Center, demonstrating the high precision of the new expired breath sampling method.

MediPines AGM100

MediPines AGM100is the world's first non-invasive gas exchange analyzer. This advanced respiratory monitoring system was designed to rapidly detect respiratory impairment caused by conditions such as COVID-19, chronic obstructive pulmonary disease (COPD), pneumonia, ARDS, pulmonary edema, and pulmonary embolism. The device is FDA cleared and approved for Health Canada COVID-19 Emergency Use. It provides a comprehensive panel of respiratory measurements including blood oxygen levels, Oxygen Deficit (A-a gradient), P/F ratio, and alveolar oxygen and carbon dioxide levels.

About MediPines

MediPines Corporation, based inCalifornia, is a market leader in respiratory assessment and monitoring of pulmonary gas exchange. The company mission is to advance respiratory medicine by providing physiology-based respiratory devices that enhance clinical effectiveness and achieve better patient outcomes.

MediPines.com

Media contact: Carissa Drews 949-398-4670 [emailprotected]

SOURCE MediPines

http://medipines.com

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Study Finds MediPines' Breakthrough Non-invasive Gas Exchange Method Highly Precise: Ideal for Covid Response - PRNewswire

Physiology

Key to true health: A healthy mind and a healthy body always go hand in hand – YourStory

When it comes to feeling great health, it should include energy, mental equilibrium, great sleep, greater resilience to stress, and amazing creativity. Whenever you struggle with challenges involving your mind and stress, it will impact your physiology.

When you struggle with physical symptoms and conditions, it will impact your mental health. This is why the key to true health is to bring some focus into supporting a healthy body and working towards a healthy mind.

One thing that cannot be changed is stressors all around. Stress can be electromagnetic, which is something that is a part of the information age. Stress can be physiological from nutritional deficiencies or chronic inflammation. Stress can be caused by poor sleep.

The stressors might vary for each one of us, but we do not live in a bubble, and therefore we can only work on our resilience. Resilience is something that can be changed dramatically in spite of the level of stress. It might not seem possible, but it is true.

Those who sleep poorly, have nutritional deficiencies, and poor blood sugar balance struggle with resilience. Time is a big factor when it comes to a healthy mind. Some tweaks or hacks can support a healthy mind, one that is balanced and calm. What are some of the hacks that can help you keep a stable and healthy mind?

Even amid the number of apps and planners out there, there is something unique about a handwritten to-do list. I will admit that I also use a planner, but it does not come anywhere close to my quickly scribbled lists.

Image source: Shutterstock

There is a wonderful practice of scribbling your list in five minutes and putting down whatever comes in your mind the moment you wake up. This allows you to maintain clarity and great awareness through the day since this activity helps you dump everything on your mind at the get-go.

It is time-saving, releases clutter within your mind very early in the morning, and taps into your subconscious mind when you are just moving from sleep to wake.

You might wonder how taking 30 minutes to dance in your room is time-saving. This goes back to ancient wisdom. One of the reasons that your mind feels unhealthy and cluttered is restless energy.

The energy within your body is exactly like the wind. You cannot see your energy. But you can see the impact of that energy as to how cluttered, restless or unhealthy your mind feels.

In fact, taking 30 minutes in the morning to dance in your room without anyone around, where you can express your moves freely, burns away the restless energy within yourself.

What happens through the day is much better productivity and focus that saves time in everything else that you do. It is important to do this without anyone else in the room so that you can really let go!

Image source: Shutterstock

I found that the one year when I did not make separate lists, my entire year, including every month and every day, was filled with uncertainty, chaos, and lack of vision for greater goals. Separate lists should be written out for main things to do the whole year, what to do for each month as well as breakdown for each category, which will be unique to you.

You cannot imagine how much time this saves through the year in terms of direction and planning. Someone asked me how did I manage so much through the day? It had to do with this very simple time-saving practice.

I also encourage you to get a colourful book to do all of this, which will support your creativity and inspiration.

Not only is it highly possible to fall into the trap of not spending time with a loved one as you get overwhelmed by the list of things to do, but it is also very easy to not realise the value of this very simple five-minute practice. One of the biggest reasons for an unhealthy mind and poor resilience to stress is cortisol.

Cortisol is your stress hormone, which is the physiological reason that you feel more stressed. Oxytocin is a peptide hormone and neuropeptide, which is produced in your hypothalamus and then released by your pituitary. It plays a key role in breastfeeding, sexual reproduction, the birth of a child, a postnatal period, and in overall social bonding.

The fascinating thing about oxytocin is that is shares an antagonistic relationship with cortisol. When you spend five minutes hugging someone you love, your body releases oxytocin and reduces cortisol! This means that you instantly increase your resilience and have a calmer mind.

One of the main reasons for an unhealthy mind is the inability to set boundaries. Imagine a child who looks forward to the surprise at the end of a tiring school day. If I tell my little boy that I have something wonderful planned for his dinner, there is a world of difference in how inspired he is all day. He does not go around wasting his time, he is productive, and he is much more stable in his mood.

We truly are not all that different from the children in our lives. Just this morning, I had a conversation with a client who was unable to feel calm, productive or healthy because he was always waiting for the phone to ring even if it was at midnight.

Image source: Shutterstock

This one little hack was magic to my productivity, and even with much more on my plate now, I have never been as productive or as relaxed.

Saving time is not something that should be viewed with a reductionist approach of just saving time on one specific day. Time-saving has to be viewed from a greater perspective, where little hacks introduced and made a big part of your life. It should shift you towards a space where you have a calmer mind that supports your body.

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Key to true health: A healthy mind and a healthy body always go hand in hand - YourStory

Physiology

Strides in spatial genomics & transcriptomics market to transform landscape of liver physiology and disease biology – TMR Research Blog

Spatial genomics and transcriptomics have emerged as valuable tools in understanding liver physiology and disease biology. The drive for discovering new therapeutic targets for chronic liver diseases and cancer is a key trend shaping the evolving contours of the spatial genomics and transcriptomics market. The tools show incredible promise in studying rare cells such as liver progenitor cells and non-parenchymal cells in cancer. Strides made in computational analyses have led better characterisation of primary liver cancers. Expanding horizon of immunotherapy and strides made in precision medicine have broadened the canvas for industry stakeholders in the spatial genomics and transcriptomics market. Growing popularity of single-cell RNA sequencing is a key trend bolstering the prospects.

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The focus of creation of high-quality sequencing libraries or cell atlases has stirred the attention of researchers to harness spatial genomics and novel sequencing-based technologies such as spatial transcriptomics. Growing prevalence of chronic diseases and cancers has spurred the number of gene expression studies in tissues, thereby bolstering the expansion of the avenue in the spatial genomics and transcriptomics market.

Need for novel treatment strategies for liver cancer drives prospects

The need for high-quality genomic study for genetic engineering is a key factor propelling the application of next-generation sequencing. A case in point visualizing the RNA molecules at resolution equal or less than 100m. Over the years, researchers have been leveraging spatial genomics and transcriptomics for studying heterogeneity within liver cancer and expanding the understanding of the underlying tumour microenvironment. Spatial transcriptomics is likely to pave way to novel treatment strategies for liver cancer. In recent years, new spatial transcriptomic approaches have helped researchers unravel the treatment avenue for genetic diseases.

Strides made in biomedical research in oncology using high-throughput sequencing has expanded opportunities for industries looking to expand the stakes in the market. Some of the key players are Bio-Techne, Fluidigm Corporation, Illumina, and NanoString Technologies.

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Strides in spatial genomics & transcriptomics market to transform landscape of liver physiology and disease biology - TMR Research Blog

Physiology

The hidden burdens of healthcare workers – University of Victoria – University of Victoria News

Tasha Vollo-Crawford has long known that her nursing job causes her stressall the more so since the start of the pandemic.

But it wasnt until a University of Victoria researcher put a watch-sized heart rate monitor on her wrist, to wear during her shifts, that she fully grasped the impact of that stress on her physical health.

I knew that my heart rate was always high on my shift, from beginning to end, says Vollo-Crawford, a nurse at Victoria General Hospital. I see now that Im in a constant state of stress at work.

Vollo-Crawford is one of the Victoria-area health care workers recruited by UVic grad student Marisa Harrington for a study monitoring physiological stress responses in Victoria-area health care workers.

These are still early days of data collection. But for Harrington, whos pursuing a masters degree in exercise physiology, the results are already confirming what every health-care worker already knows: their work is stressful.

This is such a unique area to research during a pandemic, says Harrington, whose study is funded by WorkSafe BC and UVics Centre for Occupational Research and Testing, in the School of Exercise Science, Physical and Health Education. Her research is evaluating how well those who carry the responsibility to keep us safe and healthy, are staying safe and healthy themselves, she says.

The study is part of broader research being conducted by Lynneth Stuart-Hill, an occupational physiologist and associate professor at UVic. She is studying the stress responses of Greater Victoria front-line healthcare workers whose jobs include shift work.

The main focus of Harringtons research initially revolved around shift work itself. But then COVID-19 struck, bringing the rare opportunity to examine the objective and subjective stress levels of nursesnot just in terms of shift work, but during a global health crisis.

The 10 nurses who participated in Harringtons ongoing study wore monitoring equipment over an eight-day shift rotation. Their sleep patterns were monitored alongside the rate and variability of their heartbeats.

A reduction in variability is a signal that the bodys sympathetic nervous systemresponsible for our fight, flight or freeze responseis chronically dominating the parasympathetic nervous system, which keeps us calm. Its one of the indices of stress. When its out of kilter, we know that this is a body out of sync, says Stuart-Hill.

The research project also analyzes nurses saliva for three markers associated with stress: cortisol, melatonin, and interleukin-y. The last of these is a cytokinea protein related to the bodys immune response, now getting attention for the deadly cytokine storms that affect some people with COVID-19.

Participants also kept logs while at work, noting any high-stress incidents over the shift that might later be correlated with a change in their physiological responses.

Were still analyzing, but we have seen significant data already, around sleep in particular, says Harrington. These nurses are spending more time in light sleep and less in REM sleep. Weve looked at the cardiovascular data and there is definitely an effect there as well.

We know that this is a population that feels stressed psychologically. Now, were establishing that theres a measureable physiological impact as well.

Harringtons research will help fill critical knowledge gaps, says Stuart-Hill. Much of the research done to date on the physiological impact of stressful work has involved male-dominated professions such as firefighting and logging. Stuart-Hill hopes to build on Harringtons research findings through future studies of long-term care employees, paramedics and other community-based health care workers.

The nurses are delighted that were studying this, adds Stuart-Hill. What were learning through the data are the things they inherently know.

Ongoing analysis will examine differences in data depending on a participants specific job role. But Harrington says early results are establishing that participants stress responses are significant and similar, regardless of what department or hospital they work in.

The stress of the pandemic for health care workers goes far beyond whether theyre actually working on a COVID ward, says Stuart-Hill.

These workers have to presume that anyone they are dealing with could have COVID, she says. If you work in these facilities, you also have to worry about bringing COVID to work, so your own home life is more stressed.

Can you still hug and cuddle your kids, given that theyre back in school? Can you share a bed with your partner? You have to worry about all of that.

Phase two of Harringtons study is now underway with a new round of study subjects. She anticipates concluding her work this spring.

Stuart-Hill and Harrington ultimately hope the research will shed light on better ways to manage the stress of health-care work. The shift rotation that Island Health uses for hospital-based nurses (two day shifts, two night shifts, and four days off) is notorious for disrupting normal sleep patterns, notes Stuart-Hill. Add in a pandemic and its uncharted territory.

The anguish that health care workers are seeing in their patients, the frustration of seeing people in their communities not taking this seriously, the lack of camaraderieits amazing theyre able to keep doing what they do, says Stuart-Hill.

I think theres going to be long-term fallout from this period. This data will provide some evidence for that when the time comes.

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The hidden burdens of healthcare workers - University of Victoria - University of Victoria News

Physiology

A wet Amazon may be more resilient to a drying climate than thought: Study – Mongabay.com

In some of the wettest parts of the Amazon rainforest, dry air may increase plant photosynthesis rates a response that contradicts the assumptions of many climate models, according to a recent study published in Science Advances.

When conditions are dry, plants attempt to retain water by closing the tiny pores on their leaves called stomata. But this also reduces the rate of photosynthesis, with knock-on effects for forest growth, carbon absorption, and large-scale weather patterns. Thats the theory, but data on how these dynamics play out at the scale of whole tropical forests is limited.

An international team of researchers led by Julia Green, a postdoctoral researcher at Laboratoire des Sciences du Climat et de lEnvironnement (LSCE) in France, used machine learning to cluster data from nine years of monthly satellite images of South and Central America into areas with similar climate, and modeled the relationship between air moisture and photosynthesis in each cluster. They found that dry tropical forests and savannas showed the expected pattern: photosynthesis slowed in dryer air. However, wetter areas of the Amazon basin displayed a reverse trend, with photosynthesis actually increasing as the air dried, an effect that became even more pronounced in the wet season.

The researchers used sun-induced fluorescence (SIF), a measure of excess light energy released by photosynthesizing leaves, to estimate the rate of photosynthesis using satellite imagery. Experts say there is still scientific debate over the reliability of SIF as a measure of a forests photosynthetic output, known as gross primary production (GPP). Green acknowledged that SIF may be an unreliable measure of GPP at the scale of individual leaves, but said that SIF tracks GPP quite well at the ecosystem scale, and that this relationship has been widely exploited in other studies.

David Lapola, an Earth system modeler at the University of Campinas (UNICAMP) in Brazil, who was not involved in the study, said he is skeptical about the results, but that this article opens up a hypothesis that deserves further investigation.

To photosynthesize, plants face a trade-off. Opening their stomata allows them to absorb CO2, a crucial ingredient for photosynthesis, but in doing so they also lose water through the process of transpiration. At the same time, plants need to maintain a continuous column of water from root to leaf. If there isnt enough water available in the soil to match water loss from the stomata, the water column will become strained and eventually break. To avoid these potentially fatal breaks, plants can partly or fully close their stomata.

The team analyzed four years of hourly data collected at three established monitoring towers in the states of Amazonas, Para, and Tocantins in Brazil, which allowed them to explain the remote sensing findings and try to link the large scale to the small scale, Green said. When the air was dry, plants absorbed less CO2, suggesting that their stomata were fully or partially closed, yet their leaves were releasing the same amount of heat, indicating high rates of photosynthesis.

The authors say this can be explained, at least in part, by leaf ageing. At the beginning of the dry season, trees in wet tropical forests drop the leaves at the top of the canopy, allowing more light through and stimulating growth of plants in the understory. By the time the wet season arrives, the shed leaves have been replaced by young leaves that are able to photosynthesize far more efficiently. Even in the Amazon, the stomata will partially close when the air gets drier, but because of the higher photosynthetic capacity of the young leaves its more than compensated for, Green said.

Marielle Smith, a postdoctoral researcher at Michigan State University in the U.S., who was not involved in the study, says that plentiful soil moisture may explain why plants in wet regions are able to continue photosynthesizing even when the air is very dry.

In a separate study published in Nature Plants in October , Smith and colleagues compared photosynthesis rates with changing air temperature and humidity in a climate-controlled experimental tropical forest biome in Arizona, with data collected at monitoring towers in the Brazilian Amazon, and found declining photosynthesis rates as the air dried, indicating that plants were closing their stomata when they experienced water stress. But if the potential for hydraulic stress is alleviated by sufficient soil water, the response of stomata to air dryness may be reduced or eliminated. This would mean that forests in wet places could take full advantage of the high light availability that tends to accompany dry air, Smith said.

Smith also expressed doubts that dry air was the causal factor behind higher rates of photosynthesis in wet regions. This conclusion is opposite to what we found at the particular sites used in our analyses, she said, despite using data from two of the same monitoring towers.

The source of this disparity, Smith says, is light. If light availability, which tends to be higher when the air is dryer, is controlled for statistically, the rate of photosynthesis at the monitoring towers declines as air dryness increases. The tower analyses they use to validate the artificial neural network analysis of SIF show the opposite: [air dryness] has a negative impact on GPP when GPPs response to light is accounted for, she said. Therefore, some independent validation is required in order for this interesting hypothesis to be convincing.

Experts say controlled experiments are needed to validate and investigate these complex interactions between water availability, climate, and plant physiology in tropical forests. Im leading the effort trying to establish a FACE [free-air carbon dioxide enrichment] experiment near Manaus and it might be that we can also change moisture conditions in the air, Lapola said. This is a very good suggestion that the authors give and is something we will definitely think about.

The researchers applied the same clustering analysis to the outputs from 10 different climate models and found that they failed to replicate the regional differences in photosynthesis found in the satellite data. Models are overestimating water stress in the Amazon rainforest, Green said.

Climate models must accurately represent photosynthetic processes in the Amazon if they are to produce meaningful results, because changes in gas and water exchange between these vast forests and the atmosphere can have widespread impact on climate and weather patterns. This region is bigger than just itself, Green said.

The Amazon rainforest represents a huge stock of carbon and flux of moisture to the atmosphere, Lapola said. This misrepresentation in vegetation models might significantly change the [predicted] carbon cycle and water cycle in the region.

Green says the good news is that this data suggest Amazon forests are potentially more resilient than we thought, but cautioned that if air dryness exceeds levels currently experienced by Amazon forests, the plant physiological responses observed in this study may change.

The team found that the relationship can reverse during extreme weather events, which are also expected to become more frequent and severe as the climate warms. Their analysis included the El Nio event that caused severe and widespread droughts in the Amazon in 2015 and 2016; for that period, we see that this positive response of photosynthesis to air dryness either diminished or reversed, Green said.

Citation:

Green, J. K., Berry, J., Ciais, P., Zhang, Y., & Gentine, P. (2020). Amazon rainforest photosynthesis increases in response to atmospheric dryness. Science advances, 6(47), eabb7232.https://advances.sciencemag.org/lookup/doi/10.1126/sciadv.abb7232

Banner Image: Plants are expected to photosynthesize less in response to dry air, but a machine-learning analysis of satellite data found that the wettest parts of the Amazon basin actually photosynthesize more when the air is dry. Image by CIFOR via Visualhunt (CC BY-NC-ND).

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Physiology

11 MSU employees found in violation of OIE policy are still affiliated, LSJ reports – The State News

Content warning: This story contains descriptions of sexual abuse and sexual harassment.

Out of 49 Michigan State faculty and staff in violation of university sexual misconduct policy since 2015, at least 11 are still affiliated with the university in some way, according to an 18-month Lansing State Journal investigation.

At least 14 people had multiple people accuse them of sexual harassment or sexual assault, five of which remain employed: marketing Professor Tomas Hult, criminal justice Professor David Foran, anatomic pathology Professor Matti Kiupel, communications Professor William Donohue and physiology Professor Robert Wiseman.

Despite being found responsible for sexual harassment of a coworker and being accused of sexual misconduct two other times, Hult was a member of the presidential search committee that brought in current MSU President Samuel L. Stanley Jr.

The former Osteopathic Medicine Dean William Strampel as well as political science professor William Jacoby, were allowed to retire prior to the completion of the investigation or any punishment. According to the report, this allowed them to keep some retirement benefits, such as health and life insurance.

Strampel was arrested and jailed in 2019 for his willful neglect of the ongoing abuse committed by former MSU doctor Larry Nassar, as well as 11 months of misconduct in office.

Two retired professors lost their emeritus title, two are under review and while four others were allowed to keep them, according to the report.

Much work has been done to change the culture of Michigan State University," Deputy Spokesperson Dan Olsen said. "To foster culture change, we continue to make broad-based systemic improvements to our handling of any behavioral issues of our faculty and staff. We have strengthened compliance through our changes to the Discipline and Dismissal of Tenured Faculty for Cause Policy, Consensual Amorous or Sexual Relationships with Students Policy, Travel Policy and Emeritus Policy. Communication and collaboration have increased with Human Resources and the accountable administrators at all levels to address any and all behavioral issues. We review and investigate all reports of misconduct. Notice and transparency has strengthened the universitys ability to address behaviors, apply interim measures, and improve the quality of the working environment for the students, faculty, and staff. Culture change does not happen with one individual, it takes the whole system to work collectively to achieve the same goal ofpreventinginappropriate behaviorand creating a culture where the behavior is not tolerated. Theres no mistake we have more work to do and the university is committed to that work.

Olsen also confirmed that the contents of the report are accurate.

University administrators sent a preemptive response to MSU faculty, staff and students Friday, Jan. 15, outlining policy and procedure changes surrounding relationship violence and sexual misconduct three years after 204 women provided nine days of impact statements in Ingham and Eaton Counties in the wake of Nassar's abuse.

"Their powerful testimonies continue to remind us that MSU failed survivors and our community," the email said. "Their stories and voices challenge us to create culture change at MSU, and we know we have more work still to do."

Lansing State Journal made 25 public records requests to Michigan State University over the course of the investigation, spending nearly $2,000 for public documents.

Stanley, along with Provost Teresa Woodruff, Executive Vice President for Administration and Chief Information Officer Melissa Woo and Executive Vice President for Health Sciences Norman Beauchamp, signed the message.

"We are sharing this with you not to excuse past decisions; rather, we want you to know the actions we have taken the past few years and continue to take will improve our consistency and accountability," the email said. "Changes have been made, and more work will be completed soon to address inequities in the disciplinary outcomes and further strengthen our disciplinary actions."

Wendy Guzman contributed to the reporting in this article.

Editor's note: This article was updated to properly aggregate reporting by The Lansing State Journal.

Discussion

Share and discuss 11 MSU employees found in violation of OIE policy are still affiliated, LSJ reports on social media.

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11 MSU employees found in violation of OIE policy are still affiliated, LSJ reports - The State News

Physiology

Taking temperature is not a reliable way of detecting Covid-19 – The Star Online

Making people stand in front of a scanner to have their body temperature read can result in a large number of false negatives, allowing people with Covid-19 to pass through airports and hospitals undetected.

Leading experts in physiology have suggested that taking temperature readings of a persons fingertip and eye instead would give a significantly better and more reliable reading, and help identify those with fever.

The study, co-led by human physiologist and expert in temperature regulation Professor Mike Tipton, was published in the journal Experimental Physiology.

Prof Tipton from the University of Portsmouth in the United Kingdom says: If scanners are not giving an accurate reading, we run the risk of falsely excluding people from places they may want or need to go, and we also risk allowing people with the virus to spread the undetected infection they have.

The study found four key factors:

Prof Tipton says: Using a surface temperature scanner to obtain a single surface temperature, usually the forehead, is an unreliable method to detect the fever associated with Covid-19.

Too many factors make the measurement of a skin temperature a poor surrogate for deep body temperature skin temperature can change independently of deep body temperature for lots of reasons.

Even if such a single measure did reflect deep body temperature reliably, other things, such as exercise, can raise deep body temperature.

The pandemic has had a devastating global effect on all aspects of our lives, and unfortunately, its unlikely to be the last pandemic we face.

Its critical we develop a method of gauging if an individual has a fever thats accurate and fast.

A change in deep body temperature is a critical factor in diagnosing disease with as little as a one degree increase indicating a potential disease.

The most common symptom of 55,924 confirmed cases of Covid-19 reported in China up to Feb 22, 2020, was fever, followed by other symptoms, including dry cough, sputum production, shortness of breath, muscle or joint pain, sore throat, headache, chills, nausea or vomiting, nasal congestion, and diarrhoea.

However, the researchers say a significant proportion (at least 11%) of those with Covid-19 do not have a fever, and that fewer than half of those admitted to hospital with suspected Covid-19 had a fever.

Although the majority of positive cases go on to develop a high temperature after being admitted to hospital, they were infectious before their temperature soared.

Prof Tipton says: We think we can improve the identification of the presence of fever using the same kit, but looking at the difference between eye and finger temperature its not perfect, but it is potentially better and more reliable.

He adds: During the SARS (severe acute respiratory syndrome) epidemic in 2003, there was a need for a fast and effective mass-screening method and infrared thermography became, and remains, the cornerstone measurement, despite concerns over its reliability.

A 2005 study of 1,000 people comparing forehead temperature with three different infrared thermometers gave different temperatures, ranging from 31C to 35.6 C.

The same infrared thermometer alone varied by as much as 2C.

In another study, more than 80% of the 500 people tested using infra-red thermometers, gave a false negative result.

Such differences in skin temperature could be due to a range of reasons, including whether the individual has recently exercised, has an infection, sunburn or recently drunk alcohol, how close they stand to the scanner, the air temperature, how much fat they have, and even their blood pressure.

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Taking temperature is not a reliable way of detecting Covid-19 - The Star Online

Physiology

Women temporarily synchronize their menstrual cycles with the luminance and gravimetric cycles of the Moon – Science Advances

Many species synchronize reproductive behavior with a particular phase of the lunar cycle to increase reproductive success. In humans, a lunar influence on reproductive behavior remains controversial, although the human menstrual cycle has a period close to that of the lunar cycle. Here, we analyzed long-term menstrual recordings of individual women with distinct methods for biological rhythm analysis. We show that womens menstrual cycles with a period longer than 27 days were intermittently synchronous with the Moons luminance and/or gravimetric cycles. With age and upon exposure to artificial nocturnal light, menstrual cycles shortened and lost this synchrony. We hypothesize that in ancient times, human reproductive behavior was synchronous with the Moon but that our modern lifestyles have changed reproductive physiology and behavior.

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Women temporarily synchronize their menstrual cycles with the luminance and gravimetric cycles of the Moon - Science Advances