Our minds may be affected by winter’s long nights or spring flowers, but what about our bodies? A new study at the Weizmann Institute of Science in Israel reveals that our hormones also follow a seasonal pattern.

By analyzing the data on several kinds of hormone from millions of blood tests, the researchers discovered that some hormones peak in winter or spring, and others in summer. This research, which was published in the Proceedings of the National Academy of Sciences (PNAS), USA, provides a broad, dynamic picture of hormone production – covering those connected, for example, to fertility, but also hormones such as cortisol, which are mostly short-lived and not thought to be seasonal.

Alon Bar led the study together with Avichai Tendler; both are research students in Prof. Uri Alon’s group at the Institute’s Molecular Cell Biology Department.

Alon and his group have developed mathematical tools for uncovering patterns in big biological data, so when a study they had undertaken that focused on a single hormone – cortisol – started to reveal a surprising seasonal pattern, the research team decided to see whether other hormones might also fluctuate seasonally.

They turned to Prof. Amos Tanay of the Computer Science and Applied Mathematics Department, who has access to a database maintained by the Clalit health maintenance organization. Clalit is the largest HMO in Israel and a leader in creating a database that enables researchers to conduct large-scale biomedical studies while fully preserving the subjects’ anonymity. This is the same kind of data that was accessed to understand the impact of Pfizer’s Covid vaccine on immunisation rates.

The team analyzed the hormone levels in males and females between the ages of 20 and 50, in millions of blood tests sorted according to the months of the year. The team estimated that they had ultimately analyzed 46 million person-years; the results for each hormone were averaged from up to six million different blood tests. The researchers tracked 11 different hormones, including cortisol (a stress hormone released by the adrenal glands), a thyroid hormone, reproduction and sex-based hormones and a growth hormone produced in the liver.

Hormones bring babies, not spring flowers

On average, all of these hormones exhibited peaks and dips over the year with a seasonal variation of around 5 percent, but the surprise was the ways in which certain ones peaked at different times. For example, the hormones testosterone and estradiol – one more prevalent in men, the other in women – were mirror images of one another.

That is, in men testosterone peaked in January and again, a bit lower, in August; and in women, estradiol followed the same pattern. In contrast, testosterone in women and estradiol in men peaked closer to April and dipped in the summer.

So the fact that more children are conceived in certain seasons may have more to do with hormone balances than the blooming of flowers in the fields, says Bar.

The difference between hormones that peak in winter-spring and those that wait for summer was more confusing, especially as the ones that peak later in the year – in summer – tend to be the hormones that control the first kind. These hormones are produced in the pituitary, at the base of the brain, and they send messages to the reproductive organs, adrenal glands and others organs that then affect or control bodily functions or reactions.

The researchers call these second hormones effector hormones – that is, the hormones that act directly on the body – and they devised a mathematical model to explain why these two kinds of hormones, which are directly related, should have different high and low seasons. Effector hormones such as cortisol and the pituitary hormones, explains Bar, affect not just the body’s metabolism and functions, but the masses of the organs themselves that secrete the hormones.

That is, the pituitary hormones that stimulate the adrenal glands to produce cortisol also cause these glands to grow. But the cortisol produced in the adrenals causes the pituitary to shrink, thus eventually reducing the amount of stimulation to the adrenals, which shrink back down, and so on in a continual loop.

The dynamic growth and shrinkage of such glands is a known phenomenon, and the researchers were able to link studies measuring the glands to the hormone fluctuations they had observed. Because the entire process takes place gradually over weeks and months, it creates a time lag from winter to summer and back again, and this explains the differences in peaks between the two groups of hormones.

While the exact cause of this cycle was not the subject of the study, the team believes that melatonin – a hormone made in the brain that is triggered by light and dark – is most likely the “hand” that sets this year-long clock in motion.

And assuming that this is the case, they would expect the patterns they found in the Israeli population to be six months earlier (or later) in the Southern Hemisphere, and that stronger peaks and valleys would be found in the population living farther North, where day length between seasons, and thus melatonin production, differs by much more than in Israel. “If we saw a 5 percent difference in Israel, that could be over 15 percent in Northern Europe,” says Bar, and the team did, indeed, find some evidence in the literature on cortisol from the UK, Sweden and Australia to support this idea.

“It is not so surprising that our hormones have seasonal cycles,” adds Alon. “Many animals living in temperate climates have strong cycles, for example, all giving birth in the same season. We think that our hormonal systems have ‘set points’ that produce peaks, for example, in stress or reproductive hormones, and these may be adaptations that evolved to help us cope with seasonal changes in our surrounding environment.”

The post Women and men in sync hormonally in January and August appeared first on Green Prophet.

Researchers are trying to crack the code on how to replicate smell so they can make an algorithm to recreate them digitally. The smell of burnt pizza, the smell of New York in the summer, the scent of a woman. They are trying to do it at Intel and now scientists from Israel (we reported in 2012 when they were mapping the smell of white noise) are taking on the ideas of Alexander Graham Bell to map smells. 

Fragrances – promising mystery, intrigue and forbidden thrills – are blended by master perfumers, their recipes kept secret. But in a new study on the sense of smell, scientists from the Weizmann Institute of Science have managed to strip much of the mystery from even complex blends of odorants, not by uncovering their secret ingredients, but by recording and mapping how they are perceived.

The scientists can now predict how any complex odor will smell from its molecular structure alone.  This study may not only revolutionize the closed world of perfumery, but eventually lead to the ability to digitize and reproduce smells on command.

The proposed framework for odors, created by neurobiologists, computer scientists, and a master-perfumer, and funded by a European initiative for Future Emerging Technologies (FET-OPEN), was published today in Nature.

“The challenge of plotting smells in an organized and logical manner was first proposed by Alexander Graham Bell over 100 years ago,” says Prof. Noam Sobel of the Institute’s Neurobiology Department.

Bell threw down the gauntlet: “We have very many different kinds of smells, all the way from the odor of violets and roses up to asafoetida. But until you can measure their likenesses and differences you can have no science of odor.”

How the nose knows

This challenge had remained unresolved until now.

This century-old challenge indeed highlighted the difficulty in fitting odors into a logical system: There are millions of odor receptors in our noses, consisting hundreds of different subtypes, each shaped to detect particular molecular features. Our brains potentially perceive millions of smells in which these single molecules are mixed and blended at varying intensities. Thus, mapping this information has been a challenge.

But Sobel and his colleagues, led by graduate student Aharon Ravia and Kobi Snitz, found there is an underlying order to odors. They reached this conclusion by adopting Bell’s concept – namely to describe not the smells themselves, but rather the relationships between smells as they are perceived.

In a series of experiments, the team presented volunteer participants with pairs of smells and asked them to rate these smells on how similar the two seemed to one another, ranking the pairs on a similarity scale ranging from “identical” to “extremely different.”

In the initial experiment, the team created 14 aromatic blends, each made of about 10 molecular components, and presented them two at a time to nearly 200 volunteers, so that by the end of the experiment each volunteer had evaluated 95 pairs.

To translate the resulting database of thousands of reported perceptual similarity ratings into a useful layout, the team refined a physicochemical measure they had previously developed. In this calculation, each odorant is represented by a single vector that combines 21 physical measures (polarity, molecular weight, etc.).

To compare two odorants, each represented by a vector, the angle between the vectors is taken to reflect the perceptual similarity between them. A pair of odorants with a low angle distance between them are predicted similar, those with high angle distance between them are predicted different.

To test this model, the team first applied it to data collected by others, primarily a large study in odor discrimination by Bushdid and colleagues from the lab of Prof. Leslie Vosshall at the Rockefeller Institute in New York.

The Weizmann team found that their model and measurements accurately predicted the Bushdid results: Odorants with low angle distance between them were hard to discriminate; odors with high angle distance between them were easy to discriminate. Encouraged by the model accurately predicting data collected by others, the team continued to test for themselves.

The team concocted new scents and invited a fresh group of volunteers to smell them, again using their method to predict how this set of participants would rate the pairs – at first 14 new blends and then, in the next experiment, 100 blends.

The model performed exceptionally well. In fact, the results were in the same ballpark as those for color perception – sensory information that is grounded in well-defined parameters. This was especially surprising considering each individual likely has a unique complement of smell receptor subtypes, which can vary by as much as 30% across individuals.

Because the “smell map,” or “metric” predicts the similarity of any two odorants, it can also be used to predict how an odorant will ultimately smell. For example, any novel odorant that is within 0.05 radians or less from banana will smell exactly like banana. As the novel odorant gains distance from banana, it will smell banana-ish, and beyond a certain distance, it will stop resembling banana.

Think color mapping but with smell

The team is now developing a web-based tool. This set of tools not only predicts how a novel odorant will smell, but can also synthesize odorants by design. For example, one can take any perfume with a known set of ingredients, and using the map and metric, generate a new perfume with no components in common with the original perfume, but with exactly the same smell. Such creations in color vision, namely non-overlapping spectral compositions that generate the same perceived color, are called color metamers, and here the team generated olfactory metamers.

The study’s findings are a significant step toward realizing a vision of Prof. David Harel of the Computer and Applied Mathematics Department, a co-author of the study: Enabling computers to digitize and reproduce smells.

Environmental remediation using odor tech

In addition, of course, to being able to add realistic flower or sea aromas to your vacation pictures on social media, giving computers the ability to interpret odors in the way that humans do could have an impact on environmental monitoring and the biomedical and food industries, to name a few. Still, master perfumer Christophe Laudamiel, who is also a co-author of the study, remarks that he is not concerned for his profession just yet.

Sobel concludes: “100 years ago, Alexander Graham Bell posed a challenge. We have now answered it: The distance between rose and violet is 0.202 radians (they are remotely similar), the distance between violet and asafoetida is 0.5 radians (they are very different), and the difference between rose and asafoetida is 0.565 radians (they are even more different). We have converted odor percepts into numbers, and this should indeed advance the science of odor.”

The post Computers now understand how to print smell appeared first on Green Prophet.

That fact that oxytocin is two-faced is a conclusion drawn from research from the Weizmann Institute of Science in Israel. There researchers took mice living in semi-natural conditions and then had their oxytocin producing brain cells manipulated in a highly precise manner. The findings, which were published in the science journal Neuron, could shed new light on efforts to use oxytocin to treat a variety of psychiatric conditions, from social anxiety and autism (may be linked to chemicals in our diet) to schizophrenia.

Much of what we know about the actions of neuromodulators like oxytocin comes from behavioral studies of lab animals in standard lab conditions. These conditions are strictly controlled and artificial, in part so that researchers can limit the number of variables affecting behavior. But a number of recent studies suggest that the actions of a mouse in a semi-natural environment can teach us much more about natural behavior, especially when we mean to apply those findings to humans.

Prof. Alon Chen’s lab group at the Institute’s Neurobiology Department have created an experimental setup that enables them to observe mice in something approaching their natural living conditions – an environment enriched with stimuli they can explore – and their activity is monitored day and night with cameras and analyzed computationally.

The present study, which has been ongoing for the past eight years, was led by research students Sergey Anpilov and Noa Eren, and Staff Scientist Dr. Yair Shemesh in Prof. Chen’s lab group. The innovation in this experiment, however, was to incorporate optogenetics – a method that enables researchers to turn specific neurons in the brain on or off using light. To create an optogenetic setup that would enable the team to study mice that were behaving naturally, the group developed a compact, lightweight, wireless device with which the scientists could activate nerve cells by remote control. With the help of optogenetics expert Prof. Ofer Yizhar of the same department, the group introduced a protein previously developed by Yizhar into the oxytocin-producing brain cells in the mice. When light from the wireless device touched those neurons, they became more sensitized to input from the other brain cells in their network.

“Our first goal,” says Anpilov, “was to reach that ‘sweet spot’ of experimental setups in which we track behavior in a natural environment, without relinquishing the ability to ask pointed scientific questions about brain functions.”

Shemesh adds that, “the classical experimental setup is not only lacking in stimuli, the measurements tend to span mere minutes, while we had the capacity to track social dynamics in a group over the course of days.”

Delving into the role of oxytocin was sort of a test drive for the experimental system. It had been believed that this hormone mediates pro-social behavior. But findings have been conflicting, and some have proposed another hypothesis, termed “social salience” stating that oxytocin might be involved in amplifying the perception of diverse social cues, which could then result in pro-social or antagonistic behaviors, depending on such factors as individual character and their environment.

To test the social salience hypothesis, the team used mice in which they could gently activate the oxytocin-producing cells in the hypothalamus, placing them first in the enriched, semi-natural lab environments. To compare, they repeated the experiment with mice placed in the standard, sterile lab setups.

Applying love to the pharma industry

In the semi-natural environment, the mice at first displayed heightened interest in one another, but this was soon accompanied by a rise in aggressive behavior. In contrast, increasing oxytocin production in the mice in classical lab conditions resulted in reduced aggression. “In an all-male, natural social setting, we would expect to see belligerent behavior as they compete for territory or food,” says Anpilov. “That is, the social conditions are conducive to competition and aggression. In the standard lab setup, a different social situation leads to a different effect for the oxytocin.”

If the “love hormone” is more likely a “social hormone,” what does that mean for its pharmaceutical applications?

“Oxytocin is involved, as previous experiments have shown, in such social behaviors as making eye contact or feelings of closeness,” says Eren, “but our work shows it does not improve sociability across the board. Its effects depend on both context and personality.”

The post Why awesome girlfriends suddenly go psycho appeared first on Green Prophet.

Famous for saying “We don’t pay taxes. Only little people pay taxes,” Helmsley left $4 billion for the Leona M. and Harry B. Helmsley Charitable Trust that is now valued at roughly $5-8 billion. And $15 million of that, the trust recently announced, will be used to fund a dynamic joint program between the Weizmann Institute of Science and Technion-Israel Institute of Technology to accelerate renewable energy research.

Dubious origins aside, the grant will allow dozens of researchers from the two institutions to reach across a myriad of disciplines to find new ways to generation energy from biofuels, photovoltaics, and to capture light using optics.

And the marriage between Israel’s leading research institution, Weizmann to Technion’s world-renowned engineering and technical savvy is expected to catalyze a giant leap forward in a country that still relies deeply on polluting fossil fuels despite having very little of their own.

“In addition to advancing new avenues of research, the new gift will serve to expand and strengthen the success of existing alternative energy programs,” the trust announced.

The Weizmann Institute’s Alternative Energy Research Initiative (AERI), the Grand Technion Energy Program (GTEP) and the Israeli Center of Research Excellence (ICORE) in alternative energy will all receive an influx of cash to help advance their existing work.

Biofuels, photovoltaics, optics

‘The biofuels research includes generating effective methods for breaking down waste plant matter into usable fuel resources, developing algae that can produce biofuels economically and developing plants that can be grown sustainably and provide materials that can easily be converted to biofuel,” PR representative Batya Greenman explained in a recent press release.

This research will be conducted at the Weizmann Institute in new state-of-the-art facilities funded by the trust.

Research will also focus on developing more efficient photovoltaic cells to increase the amount of energy that they can absorb from the sun, while other teams will focus on developing some of the most cutting-edge optic materials, research and designs such as plasmonics, nano structures and metamaterials.

The Weizmann Institute’s Prof. David Cahen heads the Helmsley project together with Prof. Gideon Grader of the Technion.

“Alternative energy is one of the most important, as well as one of the most exciting, fields of research today,” said Prof. Cahen.

“With this grant from the Helmsley Trust, we hope to attract bright, innovative researchers and students to the field. We know that a whole array of energy options will be needed to replace today’s nonrenewable and polluting fossil fuels; all of our present efforts are essential to ensure our energy future.”

Top image via cdn6

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