Skiing over Christmas holidays no longer guaranteed – even with snow guns

Peer-Reviewed Publication

UNIVERSITY OF BASEL

 

IMAGE: TECHNICAL SNOWMAKING ON THE GEMSSTOCK, SWITZERLAND. view more 

CREDIT: VALENTIN LUTHIGER

For many people, holidays in the snow are as much a part of the end of the year as Christmas trees and fireworks. As global warming progresses, however, white slopes are becoming increasingly rare. Researchers at the University of Basel have calculated how well one of Switzerland’s largest ski resorts will remain snow reliable with technical snowmaking by the year 2100, and how much water this snow will consume.

The future for ski sports in Switzerland looks anything but rosy – or rather white. Current climate models predict that there will be more precipitation in winter in the coming decades, but that it will fall as rain instead of snow. Despite this, one investor recently spent several million Swiss francs on expanding the Andermatt-Sedrun-Disentis ski resort. A short-sighted decision they will regret in future?

A research team led by Dr. Erika Hiltbrunner from the Department of Environmental Sciences at the University of Basel has now calculated the extent to which this ski resort can maintain its economically important Christmas holidays and a ski season of at least 100 days with and without snowmaking. The team collected data on the aspects of the slopes, where and when the snow is produced at the ski resort and with how much water. They then applied the latest climate change scenarios (CH2018) in combination with the SkiSim 2.0 simulation software for projections of snow conditions with and without technical snowmaking. The results of their investigations were recently published in the International Journal of Biometeorology.

No guarantee of a white Christmas

According to the results, the use of technical snow can indeed guarantee a 100-day ski season – in the higher parts of the ski resort (at 1,800 meters and above), at least. But business is likely to be tight during the Christmas holidays in coming decades, with the weather often not cold enough at this time and in the weeks before. In the scenario with unabated greenhouse gas emissions, the Sedrun region in particular will no longer be able to offer guaranteed snow over Christmas in the longer term. New snow guns may alleviate the situation to a certain extent, say the researchers, but will not resolve the issue completely.

“Many people don’t realize that you also need certain weather conditions for snowmaking,” explains Hiltbrunner. “It must not be too warm or too humid, otherwise there will not be enough evaporation cooling for the sprayed water to freeze in the air and come down as snow.” Warm air absorbs more moisture and so, as winters become warmer, it also gets increasingly difficult or impossible to produce snow technically. In other words: “Here, the laws of physics set clear limits for snowmaking.”

540 million liters

The skiing will still go on, however, because technical snowmaking at least enables resort operators to keep the higher ski runs open for 100 consecutive days – even up until the end of the century and with climate change continuing unabated. But there is a high price to be paid for this. The researchers’ calculations show that water consumption for snowmaking will increase significantly, by about 80% for the resort as a whole. In an average winter toward the end of the century, consumption would thus amount to about 540 million liters of water, compared with 300 million liters today.

But this increase in water demand is still relatively moderate compared with other ski resorts, the researchers emphasize. Earlier studies had shown that water consumption for snowmaking in the Scuol ski resort, for example, would increase by a factor of 2.4 to 5, because the area covered with snow there will have to be largely expanded in order to guarantee snow reliability.

For their analysis, the researchers considered periods of 30 years. However, there are large annual fluctuations: In addition, extreme events are not depicted in the climate scenarios. In the winter of 2017 with low levels of snow, water consumption for snowmaking in one of the three sub-areas of Andermatt-Sedrun-Disentis tripled.

Technical snowmaking requires certain weather conditions.

CREDIT

Erika Hiltbrunner, University of Basel

Conflicts over water use

Today, some of the water used for snowmaking in the largest sub-area of Andermatt-Sedrun-Disentis comes from the Oberalpsee. A maximum of 200 million liters may be withdrawn annually for this purpose. If climate change continues unabated, this source of water will last until the middle of the century, at which point new sources will have to be exploited. “The Oberalpsee is also used to produce hydroelectric power,” says Dr. Maria Vorkauf, lead author of the study, who now works at the Agroscope research station. “Here, we are likely to see a conflict between the water demands for the ski resort and those for hydropower generation.”

At first, this ski resort may even benefit from climate change – if lower-lying and smaller ski resorts are obliged to close, tourists will move to larger resorts at higher altitude, one of which is Andermatt-Sedrun-Disentis.

What is certain is that increased snowmaking will drive up costs and thus also the price of ski holidays. “Sooner or later, people with average incomes will simply no longer be able to afford them,” says Hiltbrunner.

---

JOURNAL

International Journal of Biometeorology

DOI

10.1007/s00484-022-02394-z 

Actinidia arguta (sarunashi) juice inhibits lung cancer in mice

Using a mouse model, Japanese researchers unleash the likely mechanism of action of Sarunashi juice on lung cancer development

Peer-Reviewed Publication

OKAYAMA UNIVERSITY

 

IMAGE: IN A STUDY BY RESEARCHERS FROM OKAYAMA UNIVERSITY, ACTINIDIA ARGUTA (SARUNASHI) JUICE REDUCED TUMOR NODULES IN CARCINOGEN-EXPOSED MICE view more 

CREDIT: SAKAE ARIMOTO‑KOBAYASHI

Lung cancer is the leading cause of death in Japan and across the globe. Among all the cancers, lung cancer has one of the lowest five-year survival rates. Smoking tobacco and using tobacco-based products is known to heavily contribute to the development of lung cancer. It is a clinically established fact that the active ingredients in various fruits minimize the risk of chronic diseases including cancer. “Sarunashi” (Actinidia arguta) is an edible fruit cultivated in Japan’s Okayama Prefecture. Using a mouse model, researchers from Okayama University led by Dr. Sakae Arimoto‑Kobayashi, Associate Professor in the Faculty of Pharmaceutical Sciences, Okayama University, have shown that Sarunashi juice and its constituting component isoquercetin (isoQ) help prevent and reduce lung cancer.

 

A. arguta is one of the richest sources of polyphenols and vitamin C. Previously, the researchers had demonstrated the inhibitory effect of Sarunashi juice (sar-j) on mutagenesis, inflammation, and mouse skin tumorigenesis. They had identified the components of A. arguta responsible for the anti-mutagenic effects as water-soluble and heat-sensitive phenolic compounds. Subsequently, the researchers proposed the polyphenolic compound isoQ as a constituting component with anticarcinogenic potential.

 

Dr. Arimoto‑Kobayashi explains, “In this study, we sought to investigate the chemo‑preventive effects of A. arguta juice and its constituting component isoQ on 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced lung tumorigenesis in A/J mice, and identify the possible mechanisms underlying the anti-tumorigenic effects of A. arguta.”

 

To this end, the team induced tumor growth in mice using NNK, a known cancer-causing compound present in tobacco products. Using a series of experiments and controls, the team studied the effects of sar-j and isoQ on lung tumorigenesis in mice.

 

The results were encouraging: The number of tumor nodules per mouse lung in the group that received NNK injections and oral doses of A. arguta juice was significantly lower than that in the group injected with NNK only. Moreover, the oral administration of isoQ also reduced the number of nodules in the mouse lungs.

 

Next, the team broke ground by discovering the likely mechanism of action. NNK and 1-methyl-3-nitro-1-nitrosoguanidine or “MNNG” are known mutagens—agents that trigger DNA mutations. The team therefore designed a series of experiments to study the effect of sar-j and isoQ on NNK- and MNNG-mediated mutagenesis using Salmonella typhimurium TA1535—a bacterial strain commonly used for detecting DNA mutations. As expected, the mutagenicity of NNK and MNNG detected using S. typhimurium TA1535 decreased in the presence of sar-j. However, when similar tests were conducted using S. typhimurium YG7108, a strain lacking key enzymes responsible for DNA repair, sar-j was unable to decrease the mutagenic effects of NNK and MNNG. Based on this critical observation, the researchers concluded that sar-j seems to mediate its antimutagenic effect by accelerating DNA repair.

 

Finally, using cell-based experiments, the team also showed that sar-j suppressed the action of “Akt,” a key protein involved in cancer signaling. It is a known fact that Akt and an associated protein called “PI3k,” get over-activated in several human cancers.

 

Co-author Katsuyuki Kiura, a Professor in the Department of Allergy and Respiratory Medicine, Okayama University Hospital, muses, “Sar-j and isoQ reduced NNK-induced lung tumorigenesis. Sar-j targets both the initiation and growth or progression steps during carcinogenesis, specifically via anti-mutagenesis, stimulation of alkyl DNA adduct repair, and suppression of Akt-mediated growth signaling. IsoQ might contribute in part to the biological effects of sar-j via suppression of Akt phosphorylation, but it may not be the main active ingredient.”

 

Their findings were published on 9 December 2022 in Genes and Environment.

 

In summary, the study shows that lung tumorigenesis in mice was suppressed following the oral intake of sar-j. Although clinical trials are warranted, the constituting components of sar-j, including isoQ, seem to be attractive candidates for chemoprevention.

 

About Okayama University, Japan

As one of the leading universities in Japan, Okayama University aims to create and establish a new paradigm for the sustainable development of the world. Okayama University offers a wide range of academic fields, which become the basis of the integrated graduate schools. This not only allows us to conduct the most advanced and up-to-date research, but also provides an enriching educational experience.

Website: https://www.okayama-u.ac.jp/index_e.html

 

About Dr. Sakae Arimoto‑Kobayashi from Okayama University, Japan

Dr. Sakae Arimoto‑Kobayashi works as an Associate Professor at Okayama University’s Faculty of Pharmaceutical Sciences. Dr. Arimoto‑Kobayashi has multiple publications to her credit. Her research group primarily conducts studies on mutations and DNA damage induced by N-nitrosamino acids and near-ultraviolet irradiation, analysis of oxidative and alkylative DNA damage caused by the genotoxic agents, anti-carcinogenesis/anti-mutagenesis, and the chemopreventive effect of active ingredients in fruits and drinks.

---

JOURNAL

Genes and Environment

DOI

10.1186/s41021-022-00255-0 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Chemopreventive effects and anti-tumorigenic mechanisms of Actinidia arguta, known as sarunashi in Japan toward 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)- induced lung tumorigenesis in a/J mouse

ARTICLE PUBLICATION DATE

9-Dec-2022

COI STATEMENT

The authors declare that they have no competing interests.

Singing supports stroke rehabilitation

Peer-Reviewed Publication

UNIVERSITY OF HELSINKI

Language function and the psychosocial wellbeing of patients and their families can be promoted with singing-based rehabilitation. Group intervention provides opportunities for peer support while being simultaneously cost effective.

Approximately 40% of stroke survivors experience aphasia, a difficulty to comprehend or produce spoken or written language caused by a cerebrovascular accident. In half of these cases the language impairment still persists one year post-stroke. Aphasia has wide-ranging effects on the ability to function and quality of life of stroke survivors and easily leads to social isolation.

According to a recent study conducted at the University of Helsinki, singing-based group rehabilitation can support communication and speech production of patients and increase social activity even at the chronic phase of stroke. The burden experienced among the family caregivers participating in the study also decreased notably.

“Our study is the first where caregivers participated in rehabilitation and their psychological wellbeing was evaluated,” says Postdoctoral Researcher Sini-Tuuli Siponkoski.

Versatile use of music supports recovery

Previous research has established that the ability to sing can be retained even in severe aphasia. However, the use of singing, especially choral singing, in aphasia rehabilitation has not been widely studied.

“Our study utilised a wide variety of singing elements, such as choral singing, melodic intonation therapy and tablet-assisted singing training,” clarifies Doctoral Researcher Anni Pitkäniemi. 

In melodic intonation therapy, speech production is practised gradually by utilising melody and rhythm to progress from singing towards speech production.

In the study, rehabilitation sessions were led by a trained music therapist and a trained choir conductor. 

New and effective forms of rehabilitation needed

In addition to speech therapy, melodic intonation therapy has been used to some extent in aphasia rehabilitation. Therapy has typically been implemented as individual therapy, requiring a great deal of resources.

According to the researchers,  singing-based group rehabilitation should be utilised in healthcare as part of aphasia rehabilitation.

“In addition to training in speech production, group-based rehabilitation provides an excellent opportunity for peer support both for the patients and their families,” says Sini-Tuuli Siponkoski.

---

JOURNAL

Brain Communications

DOI

10.1093/braincomms/fcac337 

ARTICLE TITLE

Efficacy of a multicomponent singing intervention on communication and psychosocial functioning in chronic aphasia: a randomized controlled crossover trial

POSTMODERN DR.FRANKENSTEIN

Human brain organoids implanted into mouse cortex respond to visual stimuli for first time

Using innovative recording technology, researchers show organoids respond to external sensory stimuli

Peer-Reviewed Publication

UNIVERSITY OF CALIFORNIA - SAN DIEGO

 

IMAGE: MADISON WILSON, A PHD STUDENT AT UC SAN DIEGO, IS FIRST AUTHOR OF THE STUDY SHOWING THAT HUMAN BRAIN ORGANOIDS IMPLANTED IN MICE HAVE ESTABLISHED FUNCTIONAL CONNECTIVITY TO THE ANIMALS’ CORTEX AND RESPONDED TO EXTERNAL SENSORY STIMULI. view more 

CREDIT: DAVID BAILLOT/UC SAN DIEGO

A team of engineers and neuroscientists has demonstrated for the first time that human brain organoids implanted in mice have established functional connectivity to the animals’ cortex and responded to external sensory stimuli. The implanted organoids reacted to visual stimuli in the same way as surrounding tissues, an observation that researchers were able to make in real time over several months thanks to an innovative experimental setup that combines transparent graphene microelectrode arrays and two-photon imaging. 

The team, led by Duygu Kuzum, a faculty member in the University of California San Diego Department of Electrical and Computer Engineering, details their findings in the Dec. 26 issue of the journal Nature Communications. Kuzum’s team collaborated with researchers from Anna Devor’s lab at Boston University; Alysson R. Muotri’s lab at UC San Diego; and Fred H. Gage’s lab at the Salk Institute.

Human cortical organoids are derived from human induced pluripotent stem cells, which are usually derived themselves from skin cells. These brain organoids have recently emerged as promising models to study the development of the human brain, as well as a range of neurological conditions. 

But until now, no research team had been able to demonstrate that human brain organoids  implanted in the mouse cortex were able to share the same functional properties and react to stimuli in the same way. This is because the technologies used to record brain function are limited, and are generally unable to record activity that lasts just a few milliseconds. 

The UC San Diego-led team was able to solve this problem by developing experiments that combine microelectrode arrays made from transparent graphene, and two-photon imaging, a microscopy technique that can image living tissue up to one millimeter in thickness.  

“No other study has been able to record optically and electrically at the same time,” said Madison Wilson, the paper’s first author and a Ph.D. student in Kuzum’s research group at UC San Diego. “Our experiments reveal that visual stimuli evoke electrophysiological responses in the organoids, matching the responses from the surrounding cortex.” 

The researchers hope that this combination of innovative neural recording technologies to study organoids will serve as a unique platform to comprehensively evaluate organoids as models for brain development and disease, and investigate their use as neural prosthetics to restore function to lost, degenerated or damaged brain regions. 

“This experimental setup opens up unprecedented opportunities for investigations of human neural network-level dysfunctions underlying developmental brain diseases,” said Kuzum. 

Kuzum’s lab first developed the transparent graphene electrodes in 2014 and has been advancing the technology since then. The researchers used platinum nanoparticles to lower the impedance of graphene electrodes by 100 times while keeping them transparent. The low-impedance graphene electrodes are able to record and image neuronal activity at both the macroscale and single cell levels. 

By placing an array of these electrodes on top of the transplanted organoids, researchers were able to record neural activity electrically from both the implanted organoid and the surrounding host cortex in real time. Using two-photon imaging, they also observed that mouse blood vessels grew into the organoid providing necessary nutrients and oxygen to the implant. 

Researchers applied a visual stimulus–an optical white light LED–to the mice with implanted organoids, while the mice were under two-photon microscopy. They observed electrical activity in the electrode channels above the organoids showing that the organoids were reacting to the stimulus in the same way as surrounding tissue. The electrical activity propagated from the area closest to the visual cortex in the implanted organoids area through functional connections. In addition, their low noise transparent graphene electrode technology enabled electrical recording of spiking activity from the organoid and the surrounding mouse cortex. Graphene recordings showed increases in the power of gamma oscillations and phase locking of spikes from organoids to slow oscillations from mouse visual cortex.  These findings suggest that the organoids had established synaptic connections with surrounding cortex tissue three weeks after implantation, and received functional input from the mouse brain. Researchers continued these chronic multimodal experiments for eleven weeks and showed functional and morphological integration of implanted human brain organoids with the host mice cortex. 

Next steps include longer experiments involving neurological disease models, as well as incorporating calcium imaging in the experimental set up to visualize spiking activity in organoid neurons. Other methods could also be used to trace axonal projections between organoid and mouse cortex. 

“We envision that, further along the road, this combination of stem cells and neurorecording technologies will be used for modeling disease under physiological conditions; examining candidate treatments on patient-specific organoids; and evaluating organoids’ potential to restore specific lost, degenerated or damaged brain regions,” Kuzum said.  

The work was funded through the National Institutes of Health and the Research Council of Norway, as well as the National Science Foundation.

 

---

JOURNAL

Nature Communications

DOI

10.1038/s41467-022-35536-3 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Multimodal monitoring of human cortical organoids implanted in mice reveal functional connection with visual cortex

ARTICLE PUBLICATION DATE

26-Dec-2022

COI STATEMENT

The authors declare the following competing interests: A.R.M. is a co-founder and has equity interest in TISMOO, a company dedicated to genetic analysis and brain organoid modeling focusing on therapeutic applications customized for autism spectrum disorder and other neurological disorders with genetic origins. The terms of this arrangement have been reviewed and approved by the University of California San Diego in accordance with its conflict of interest policies. The remaining authors declare no competing interests.

The researchers developed experiments that combine microelectrode arrays made from transparent graphene, and two-photon imaging, a microscopy technique that can image living tissue up to one millimeter in thickness.

The researchers observed electrical activity in the electrode channels above the organoids showing that the organoids were reacting to the stimulus in the same way as surrounding tissue.

CREDIT

David Baillot/UC San Diego

Researchers were able to detect and image the border between a transplanted human brain organoid and mouse brain.

CREDIT

Credit: Madison Wilson/UC San Diego

DGIST Professor Hwang Jae-yoon's team writes letters with ultrasonic beam! Develops deep learning based real-time ultrasonic hologram generation technology

Peer-Reviewed Publication

DGIST (DAEGU GYEONGBUK INSTITUTE OF SCIENCE AND TECHNOLOGY)

□ DGIST (President: Kuk Yang) Department of Electrical Engineering and Computer Science Professor Hwang Jae-yoon's team developed a 'deep learning-based ultrasound hologram generation framework' technology that can freely configure the form of focused ultrasound in real time based on holograms. It is expected to be used as a basic technology in the field of brain stimulation and treatment that requires precision in the future.

□ Ultrasound is a safe technology even used for prenatal examination. Since it can stimulate deep areas without surgery, ultrasound methods for brain stimulation and treatment have recently been studied, and results that ultrasound brain stimulation have actually improved diseases, such as Alzheimer's disease, depression, and pain, have been published.

□ However, the problem is that it is difficult to selectively stimulate related areas of the brain in which several areas interact with each other at the same time because the current technology focuses ultrasound into a single small point or a large circle for stimulation. To solve this problem, a technology capable of freely focusing ultrasound on a desired area using the hologram principle had been proposed, but has limitations, such as low accuracy and long calculation time to generate a hologram.

□ DGIST Professor Hwang Jae-yoon's team proposed a deep learning-based learning framework that can embody free and accurate ultrasound focusing in real time by learning to generate ultrasound holograms to overcome the limitations. As a result, Professor Hwang's team demonstrated that it was possible to focus ultrasound into the desired form more accurately in a hologram creation time close to real time, and maximum 400 times faster than the existing ultrasound hologram generation algorithm method.

□ The deep learning-based learning framework proposed by the research team learns to generate ultrasonic holograms through self-supervised learning. Self-supervised learning is a method of learning to find the answer by finding a rule on its own for data with no answer. The research team proposed a methodology for learning to generate ultrasonic hologram, a deep learning network optimized for ultrasonic hologram generation, and a new loss function, while proving the validity and excellence of each component through simulations and actual experiments.

□ DGIST Department of Electrical Engineering and Computer Science Professor Hwang Jae-yoon said, “We applied deep learning technology to ultrasound holograms proposed relatively recently. As a result, we developed a technology that can freely, quickly and accurately generate and change the form of ultrasound beams,” and added, “We hope that the results of this research are used in patient-specific precision brain stimulation technology and general ultrasound fields (ultrasound imaging, thermal therapy, etc.).”

□ Meanwhile, this research was carried out with the Ministry of Science and ICT’s Four Major Institutes of Science and Technology Support Program. Researcher Lee Moon-hwan of DGIST Information and Communication Engineering Research Center, Ph.D. students Ryu Ha-min and Yoon Sang-yeon of the Department of Electrical Engineering and Computer Science, and GIST Professor Kim Tae’s team. The research results were published as a cover paper in the December edition of ‘IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control’, an international academic journal in the related field.

  Correspondent author's email address : jyhwang@dgist.ac.kr

JOURNAL

IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control

DOI

10.1109/TUFFC.2022.3219401 

ARTICLE TITLE

Deep Learning-Based Framework for Fast and Accurate Acoustic Hologram Generation

Try to be a pioneer

Peer-Reviewed Publication

COMPLEXITY SCIENCE HUB VIENNA

 

IMAGE: REGIONAL EVOLUTION OF THE NUMBER OF IN-FLOWING RESEARCHERS INTO THE FIELD OF SEMICONDUCTORS IN THE US (HEIGHT OF BARS). PANELS A–D CORRESPOND TO TIME PERIODS 1954–1970, 1970–1986, 1986–2002, AND 2002–2020, RESPECTIVELY. view more 

CREDIT: © COMPLEXITY SCIENCE HUB

If you want to open a restaurant, you first have to invest - in waiters, chefs, facilities, and equipment - to be profitable later on. “Political decision-makers and investors of a region face a similar situation. If they decide to invest in a new field of research, they have to become leaders at a certain point to be profitable,” CSH researcher Vito D. P. Servedio explains. 

RICH GET RICHER

Therefore, they need financial resources and scientists. “Early investment in emerging areas of research is a key driver of scientific dominance,” he continues. Once the pioneer has established an area or technology, researchers are also more likely to move into this new, stimulating environment. This "get-rich-richer" phenomenon underlies the development of scientific strength in a region. And scientists’ mobility drives the development of scientific disciplines. The question is, then, how many scientists does a region need to hire so that other scientists find its environment attractive and join its institutions?

NO CRITICAL MASS 

The team found no evidence for the existence of a minimum number of researchers to hire. Or in technical terms: there is no critical mass to start and carry on a new research field successfully. Here, the scientists focused on three scientific areas: semiconductors, embryonic stem cells (ESC) and internet research. 

“In a way, this contradicts the generally held belief that you need a minimum number or critical mass of researchers to make a field successful. In our study, it becomes apparent that this is not the case,” Stefan Thurner from CSH states. 

BE A PIONEER

In fact, regions seem to be successful when they manage to jump early on a train and become pioneers in a field. “We also find, as common sense suggests, that regions moving early into new technologies tend to dominate the corresponding scientific fields in the future,” Thurner explains. 

CHINA: EXPENSIVE RACE TO CATCH UP

If a region was not a pioneer, but still wants to achieve leadership in a given area of research it has to make extraordinary efforts to catch up. “Strategic interventions must be sustained over decades to compete for a leading position in a field, as is evident, for example, in Chinese semiconductor science, where the catch up-process began in the late 1970s and has led to a dominant role today,” Servedio says. 

A model specially developed by the researchers can explain the development pattern of China - how they take over specific research areas and grow the number of scientists publishing in those fields. “After all, China has some of the fastest-growing institutions worldwide. With our model, you can clearly see that China is closing the gap with the US, potentially taking on huge costs, but also showing their ability to effectively engage with high impact research. While first movers may have an advantage in some contexts, it is not necessarily impossible for late-comers to catch up or even surpass first movers in a scientific field.” CSH researcher Márcia R. Ferreira says.

THREE RESEARCH FIELDS AND MILLIONS OF DATA

With the help of the Dimensions database, the researchers at CSH could track scientists moving across regions of the world (they derived these movements from the scientists’ affiliations) in three fields - namely semiconductors, embryonic stem cells (ESC) and internet research. “In this way, we analyzed data spanning several decades with information on millions of publications, 20 million researchers and more than 98,000 research institutions worldwide,” Servedio states. 

In the field of semiconductor research, they tracked 5,062,639 articles and 2,011,170 researchers in 1,633 regions worldwide between 1941 and 2019; in the field of stem cell research, they tracked 1,083,100 articles and 752,575 researchers in 1,161 regions worldwide over the same period; and in the field of internet research, they tracked 246,953 articles and 109,098 researchers in 1,032 regions worldwide between 1956 and 2019.

“What our results clearly show is if regions want to become a leader in a field, they must try to get involved early on. It is possible to catch up, but this comes at tremendous costs,” Thurner and Servedio state. 

“Nonetheless, our model of scientific capacity building is a simplification. There are other factors contributing to the success of a field that we have not yet been able to explore here and which will be the subject of future analysis,” Ferreira states.

About CSH

The mission of the Complexity Science Hub Vienna is to host, educate, and inspire complex systems scientists dedicated to making sense of Big Data to boost science and society. Scientists at the Hub develop methods for the scientific, quantitative, and predictive understanding of complex systems.

The CSH is a joint initiative of AIT Austrian Institute of Technology, Central European University CEU, Danube University Krems, Graz University of Technology, IIASA, Medical University of Vienna, TU Wien, VetMedUni Vienna, Vienna University of Economics and Business, and Austrian Economic Chambers (WKO). https://www.csh.ac.at

---

JOURNAL

Chaos Solitons & Fractals

DOI

10.1016/j.chaos.2022.113020 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Scale-free growth in regional scientific capacity building explains long-term scientific dominance

Holding information in mind may mean storing it among synapses

Peer-Reviewed Publication

PICOWER INSTITUTE AT MIT

 

IMAGE: RESEARCHERS COMPARED THE OUTPUT (ACTIVITY ON THE TOP AND DECODER ACCURACY ON THE BOTTOM) ASSOCIATED WITH REAL NEURAL DATA (LEFT COLUMN) AND SEVERAL MODELS OF WORKING MEMORY TO THE RIGHT. THE ONES THAT BEST RESEMBLED THE REAL DATA WERE THE "PS" MODELS FEATURING SHORT-TERM SYNAPTIC PLASTICITY. view more 

CREDIT: MILLER LAB/THE PICOWER INSTITUTE AT MIT

Between the time you read the Wi-Fi password off the café’s menu board and the time you can get back to your laptop to enter it, you have to hold it in mind. If you’ve ever wondered how your brain does that, you are asking a question about working memory that has researchers have strived for decades to explain. Now MIT neuroscientists have published a key new insight to explain how it works.

In a study in PLOS Computational Biology, scientists at The Picower Institute for Learning and Memory compared measurements of brain cell activity in an animal performing a working memory task with the output of various computer models representing two theories of the underlying mechanism for holding information in mind. The results strongly favored the newer notion that a network of neurons stores the information by making short-lived changes in the pattern of their connections, or synapses, and contradicted the traditional alternative that memory is maintained by neurons remaining persistently active (like an idling engine).

While both models allowed for information to be held in mind, only the versions that allowed for synapses to transiently change connections (“short-term synaptic plasticity”) produced neural activity patterns that mimicked what was actually observed in real brains at work. The idea that brain cells maintain memories by being always “on” may be simpler, acknowledged senior author Earl K. Miller, but it doesn’t represent what nature is doing and can’t produce the sophisticated flexibility of thought that can arise from intermittent neural activity backed up by short-term synaptic plasticity.

“You need these kinds of mechanisms to give working memory activity the freedom it needs to be flexible,” said Miller, Picower Professor Neuroscience in MIT’s Department of Brain and Cognitive Sciences (BCS). “If working memory was just sustained activity alone, it would be as simple as a light switch. But working memory is as complex and dynamic as our thoughts.”

Co-lead author Leo Kozachkov, who earned his PhD at MIT in November for theoretical modeling work including this study, said matching computer models to real-world data was crucial.

“Most people think that working memory ‘happens’ in neurons—persistent neural activity gives rise to persistent thoughts. However, this view has come under recent scrutiny because it does not really agree with the data,” said Kozachkov who was co-supervised by co-senior author Jean-Jacques Slotine, a professor in BCS and mechanical engineering. “Using artificial neural networks with short-term synaptic plasticity, we show that synaptic activity (instead of neural activity) can be a substrate for working memory. The important takeaway from our paper is: these ‘plastic’ neural network models are more brain-like, in a quantitative sense, and also have additional functional benefits in terms of robustness.”

Matching models with nature

Alongside co-lead author John Tauber, an MIT graduate student, Kozachkov’s goal was not just to determine how working memory information might be held in mind, but to shed light on which way nature actually does it. That meant starting with “ground truth” measurements of the electrical “spiking” activity of hundreds of neurons in the prefrontal cortex of an animal as it played a working memory game. In each of many rounds the animal was shown an image that then disappeared. A second later it would see two images including the original and had to look at the original to earn a little reward. The key moment is that intervening second, called the “delay period,” in which the image must be kept in mind in advance of the test.

The team consistently observed what Miller’s lab has seen many times before: The neurons spike a lot when seeing the original image, spike only intermittently during the delay, and then spike again when the images must be recalled during the test (these dynamics are governed by an interplay of beta and gamma frequency brain rhtyhms). In other words, spiking is strong when information must be initially stored and when it must be recalled but is only sporadic when it has to be maintained. The spiking is not persistent during the delay.

Moreover, the team trained software “decoders” to read out the working memory information from the measurements of spiking activity. They were highly accurate when spiking was high, but not when it was low, as in the delay period. This suggested that spiking doesn’t represent information during the delay. But that raised a crucial question: If spiking doesn’t hold information in mind, what does?

Researchers including Mark Stokes at the University of Oxford have proposed that changes in the relative strength, or “weights,” of synapses could store the information instead. The MIT team put that idea to the test by computationally modeling neural networks embodying two versions of each main theory. As with the real animal, the machine learning networks were trained to perform the same working memory task and to output neural activity that could also be interpreted by a decoder.

The upshot is that the computational networks that allowed for short-term synaptic plasticity to encode information spiked when the actual brain spiked and didn’t when it didn’t. The networks featuring constant spiking as the method for maintaining memory spiked all the time including when the natural brain did not. And the decoder results revealed that accuracy dropped during the delay period in the synaptic plasticity models but remained unnaturally high in the persistent spiking models.

In another layer of analysis, the team created a decoder to read out information from the synaptic weights. They found that during the delay period, the synapses represented the working memory information that the spiking did not.

Among the two model versions that featured short-term synaptic plasticity the most realistic one was called “PS-Hebb,” which features a negative feedback loop that keeps the neural network stable and robust, Kozachkov said.

Workings of working memory

In addition to matching nature better, the synaptic plasticity models also conferred other benefits that likely matter to real brains. One was that the plasticity models retained information in their synaptic weightings even after as many as half of the artificial neurons were “ablated.” The persistent activity models broke down after losing just 10-20 percent of their synapses. And, Miller added, just spiking occasionally requires less energy than spiking persistently.

Furthermore, Miller said, quick bursts of spiking rather than persistent spiking leaves room in time for storing more than one item in memory. Research has shown that people can hold up to four different things in working memory. Miller’s lab plans new experiments to determine whether models with intermittent spiking and synaptic weight-based information storage appropriately match real neural data when animals must hold multiple things in mind rather than just one image.

In addition to Miller, Kozachkov, Tauber and Slotine, the paper’s other authors are Mikael Lundqvist and Scott Brincat.

The Office of Naval Research, the JPB Foundation, and ERC and VR Starting Grants funded the research.

---

JOURNAL

PLoS Computational Biology

DOI

10.1371/journal.pcbi.1010776 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Robust and brain-like working memory through short-term synaptic plasticity

ARTICLE PUBLICATION DATE

27-Dec-2022

Association of vaccination rates of staff in nursing homes, COVID-19 outcomes among residents, staff

JAMA Network Open

Peer-Reviewed Publication

JAMA NETWORK

The findings of this study of 15,000 nursing homes suggest that before the Omicron variant wave, increasing staff vaccination rates was associated with lower incidence of COVID-19 cases and deaths among residents and staff in U.S. nursing homes. However, as newer, more infectious and transmissible variants of the virus emerged, the original 2-dose regimen of the COVID-19 vaccine as recommended in December 2020 was no longer associated with lower rates of adverse COVID-19 outcomes in nursing homes. Policy makers may want to consider longer-term policy options to increase the uptake of booster doses among staff in nursing homes. 

Authors: Soham Sinha, M.S., of the University of Chicago, is the corresponding author. 

 To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/

(doi:10.1001/jamanetworkopen.2022.49002)

Editor’s Note: Please see the article for additional information, including other authors, author contributions and affiliations, conflict of interest and financial disclosures, and funding and support.

Embed this link to provide your readers free access to the full-text article This link will be live at the embargo time http://jamanetwork.com/journals/jamanetworkopen/fullarticle/10.1001/jamanetworkopen.2022.49002?utm_source=For_The_Media&utm_medium=referral&utm_campaign=ftm_links&utm_term=122922

---

JOURNAL

JAMA Network Open