Pusan National University researchers shed light on the early development of rice seeds

They discovered an enzyme essential for the correct growth of endosperm in rice, paving the way to higher yields

Peer-Reviewed Publication

PUSAN NATIONAL UNIVERSITY

 

IMAGE: CTP SYNTHASE IS ESSENTIAL FOR EARLY ENDOSPERM DEVELOPMENT BY REGULATING NUCLEI SPACING view more 

CREDIT: PUSAN NATIONAL UNIVERSITY

Agriculture, particularly that involving grains, has always been a steadfast pillar of civilization. Our current understanding of plant biology and genetics has helped us greatly improve the quality and yield of crops through various techniques, some of them focusing on the complex processes involved in seed development.

The seeds of most flowering plants have two distinct structures: the embryo and the endosperm. The embryo cells are created during fertilization, whereas the endosperm constitutes a structural and nutrient-rich body that protects and supports the embryo. The endosperm accounts for most of the nutritional value of the harvest in cereals like rice; many genetic studies focus on how to control the accumulation of starch during the final stages of endosperm development. On the other hand, not much is known about the genes that orchestrate early endosperm development in rice.

A team of scientists led by Assistant Professor Lae-Hyeon Cho (ORCID ID: 0000-0003-4514-4107) of Pusan National University, Korea, recently conducted a study to fill part of this knowledge gap. In their work, which was published in Plant Biotechnology Journal, the team analyzed the genome of a rice plant mutant whose seeds contained no endosperm and an abnormally enlarged embryo.

They identified a single mutation in the gene that codes for cytidine triphosphate synthase (CTPS), an enzyme that helps produce some of the building blocks of DNA and RNA. They also clarified the relationship between CTPS and the endosperm. It turns out CTPS forms macromolecular structures during the early stages of endosperm development, helping endosperm cells migrate within the seed. The mutant, having an altered form of CTPS, failed to produce this supporting structure, and thus its seeds ended up being endosperm-less.

Most notably, the scientists also showed that overexpression of CTPS in genetically modified rice plants results in a larger endosperm. This opens up an avenue for fine-tuning the size ratio between endosperm and embryo. “Controlling the embryo and endosperm size determines the quantity and quality of the seeds,” explains Dr. Cho, “It is important to increase the size of the embryo in moderation while also increasing that of the endosperm.”

Overall, the newfound insight provided by the research team could lead to more fruitful rice plantations. “Early seed development in rice ultimately determines the number of cells in the seed and is closely related to yield,” highlights Dr. Cho, “Our study may pioneer the field of research on the early development of the endosperm and contribute to improving the quality of food crops in the future.” Let us hope further progress in this field helps make food more accessible to the whole world!

 

***

 

Reference

Title of original paper: CTP synthase is essential for early endosperm development by regulating nuclei spacing

Journal: Plant Biotechnology Journal

DOI: https://doi.org/10.1111/pbi.13644

 

About Pusan National University

Pusan National University, located in Busan, South Korea, was founded in 1946, and is now the no. 1 national university of South Korea in research and educational competency. The multi-campus university also has other smaller campuses in Yangsan, Miryang, and Ami. The university prides itself on the principles of truth, freedom, and service, and has approximately 30,000 students, 1200 professors, and 750 faculty members. The university is composed of 14 colleges (schools) and one independent division, with 103 departments in all.      

Website: https://www.pusan.ac.kr/eng/Main.do

 

About the author

Lae-Hyeon Cho is an Assistant Professor at the Department of Plant Bioscience in Pusan National University, Korea. His group studies the various developmental processes of rice, a staple food crop throughout the world. They also aim to establish a molecular model system of rice for coping with recent climate changes by studying the regulation of the flowering time in rice in various external environments. Dr. Cho received a PhD in Plant Molecular Genetics from Pohang University of Science and Technology, Korea, in 2008.

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JOURNAL

Plant Biotechnology Journal

DOI

10.1111/pbi.13644 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Cells

ARTICLE TITLE

CTP synthase is essential for early endosperm development by regulating nuclei spacing

ARTICLE PUBLICATION DATE

30-May-2021

COI STATEMENT

The authors declare no conflict of interest.

Disclaimer: AAAS and EurekAlert! are not resp

Male Y chromosome facilitates the evolution of sex differences in body size

Peer-Reviewed Publication

UPPSALA UNIVERSITY

 

IMAGE: FEMALE AND A MALE (ILLUSTRATING THE SIZE CHANGE IN RESPONSE TO SELECTION) CALLOSOBRUCHUS MACULATUS BEETLE, AS WELL AS THEIR HOST PLANT VIGNA RADIATA. view more 

CREDIT: PAULA VASCONCELOS

Females and males differ in many ways and yet they share the same genome. The only exception is the male Y chromosome. Using beetles as a study system, new research from Uppsala University, now published in Nature Ecology & Evolution, shows that despite of the Y chromosome containing very few genes, it can dramatically change male body size and thus facilitate the evolution of sex differences.

Females and males typically differ in many ways in their morphology, physiology and behaviour. How such sex differences, known as sexual dimorphism, evolve is a puzzle because females and males share the same set of genes and an evolutionary change in one sex should cause a correlated change even in the other sex, thereby preventing sex differences from evolving. The new study shows that even small amounts of genetic differences between the sexes can facilitate the evolution of sexual dimorphism such that it can evolve in just a few generations.

 “Our experiments show that the autosomes as well as both sex chromosomes, the X and Y,  can harbor genetic variation important for sexual dimorphism, but the Y chromosome alone can alter the sex difference in size by as much as 30 percent. This is remarkable because in these beetles the Y chromosome contains just a handful of genes and represents a very small fraction of the genome, just like in humans. Many have thought that the Y only affects the most important reproductive processes in males, namely sperm production. Our findings suggest that the Y chromosome may have a broader role than previously appreciated,” says Philipp Kaufmann, a PhD student at the Uppsala University’s Department of Ecology and Genetics and the first author of the study.

CAPTION

Sexual size dimorphism under selection. Female seed beetle Callosobruchus maculatus (with darker colouration) and two males that differ in body size. In our study we used artificial selection to increase sexual size dimorphism, and the beetles in the photo show the variation in sex difference in size after selection.

CREDIT

Elina Immonen

The evolution of sexual dimorphism is however not only dependent on where in the genome genetic variation resides, but also on how natural and sexual selection can act on it. With the help of lab evolution, the research team showed that sexual size dimorphism could evolve when selecting on male size, but that when selection acted only on females, the shared part of the genome caused a correlated evolutionary response in males preventing dimorphism from evolving.

“The most drastic change in sexual dimorphism, an increase by 50 percent in only ten generations, occurred when we applied selection sexually antagonistically – favoring the opposite body size in the two sexes. This shows that under right kind of selection sex differences can clearly evolve rapidly, perhaps more easily than was previously thought,” says Elina Immonen, Assistant Professor at the Department of Ecology and Genetics, Uppsala University, and the principle investigator of the study.

“Combining information of what kind of genetic variation is available to selection with different forms of selection is a powerful way to test the determinants of evolution of sex differences. By isolating the effect of Y chromosome variation from the rest of the genome, we could directly demonstrate how large the effect of the Y chromosome is, something we didn’t expect to see when we started the work and this has helped understand how sexual dimorphism has evolved in this species. Future work will tell us more regarding how the Y chromosome can have such a large effect on males and how general its role is in the evolution of sex differences across taxa,” Immonen concludes.

CAPTION

Males with different Y chromosome haplotypes. The males differ in body size when they are otherwise genetically identical but differ in their Y chromosome.

CREDIT

Elina Immonen

More about the experiments

In their study, the researchers characterized the genetic architecture of body size in males and females by creating a large pedigree of over 8,000 beetles (the seed beetle Callosobruchus maculatus). This multi-generational family tree was used to quantify autosomal and sex chromosome linked genetic variation in body size. The use of artificial selection allowed testing how different forms of selection affect the evolution of size dimorphism and included selection acting only on males, only on females, or acting sexually antagonistically (in the opposite directions) in the two sexes. After ten generations of selection, the sexual size dimorphism was compared between the selection lines and the ancestral pedigree population. These two experiments clearly indicated that the Y chromosome play an important role in determining male response to selection. In order to test further the effect of the Y linked variation in isolation from variation in the rest of the genome, the research team carried out a third experiment. They isolated the effect of the Y chromosome on sexual size dimorphism in these beetles by introducing the different Y chromosomes into a genetically identical background. In other words, creating beetles that are identical twins to each other except for the Y chromosome.

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DOI

10.1038/s41559-021-01530-z 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Rapid evolution of sexual size dimorphism facilitated by Y-linked genetic variance

ARTICLE PUBLICATION DATE

18-Aug-2021

 HALT ANIMAL EXPERIMENTATION!

Prozac changes fat composition of the monkey brain

Peer-Reviewed Publication

SKOLKOVO INSTITUTE OF SCIENCE AND TECHNOLOGY (SKOLTECH)

 

IMAGE: HE STUDY LOOKED AT GENE EXPRESSION AND METABOLITE CONTENT CHANGES IN THE MACAQUE BRAIN FOLLOWING TWO-YEAR ADMINISTRATION OF THE COMMON ANTIDEPRESSANT FLUOXETINE, AKA. PROZAC. THE CONCENTRATIONS OF SOME PRODUCTS OF METABOLISM TURNED OUT TO BE DECREASED COMPARED TO THE CONTROL GROUP OF ANIMALS. SO-CALLED FREE POLYUNSATURATED FATTY ACIDS PROVED TO BE AFFECTED THE MOST. view more 

CREDIT: REWORKED BY NICOLAS POSUNKO/SKOLTECH FROM ANNA TKACHEV ET AL./INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

Skoltech researchers and their colleagues from Russia, Germany, and the U.S. have found Prozac to reduce lipid concentrations in juvenile macaques who received the antidepressant for two years, compared to a control group of untreated animals. While none of the monkeys in the study were depressed, the findings still offer a plausible biochemical explanation for the drug’s side effects, particularly in young patients. The paper was published in the International Journal of Molecular Sciences.

Prozac is the most widely prescribed antidepressant in the world and is approved in the United States for treating children as young as 8 years old with major depressive disorder and 7 years old with obsessive-compulsive disorder. There is a certain amount of controversy surrounding this use, with some studies claiming the drug might actually increase the likelihood of suicidal thinking and behaviour and that this side effect could be more pronounced in young patients. This makes biochemical research into how fluoxetine — the active compound in Prozac — affects the brain, particularly in young age, highly relevant.

A series of earlier studies on the same group of animals carried out by the team’s collaborators investigated the effects of two-year fluoxetine administration to juvenile macaques on their impulsivity, sleep, social interaction, and the concentration of peripheral metabolites — the products of metabolism measured in the blood. This time, the researchers observed the drug’s effects on gene expression and brain metabolite content, primarily that of biomolecules called lipids.

“Lipids have long been known as the building blocks of cell membranes and as the molecules storing energy in the body’s fat tissue. More recently, their importance for proper brain functioning has become increasingly apparent. Lipids are abundant in the brain, where they are found not just in the cell membranes of neurons, whose properties they modulate, but also in the so-called myelin sheaths insulating axons — the brain’s ‘wiring.’ The brain is therefore a surprisingly ‘fat’ organ — in fact, it is nearly 60% fat,” the study’s first author, Anna Tkachev from Skoltech, said.

Biochemical brain research has tied lipid abnormalities to diseases, including schizophrenia, depression, and Alzheimer’s, making these molecules an important marker of brain health.

While the study only found slight variations in gene expression and insignificant changes in nonlipid metabolite content, decreased concentrations were observed for many of the over 300 lipids measured in the post-mortem brains of the macaques using a technique called mass spectrometry. The affected lipids were those that either incorporate what’s known as polyunsaturated fatty acids or are PUFAs occurring on their own, and not as part of larger lipid molecules. These so-called free PUFAs exhibited the most dramatic drop in their concentration. A familiar example of PUFAs are the omega-3 fatty acids, which humans ingest with sea fish and some other foods. They are important for health in general and for mental health in particular.

“One clue as to why the antidepressant might have more adverse effects when administered to young patients is that the younger a child’s age, the more rapid are the natural changes in the brain. Until the age of two, babies ramp up their brain PUFA content very rapidly, which explains one of the health benefits of breastfeeding: Breast milk is rich in fats and provides lipid building blocks for brain development. Although this lipid accumulation phase slows down progressively, it might not be 100% over in young teenagers, which is roughly the age equivalent of the juvenile macaques we studied,” Tkachev conjectured.

Examining the animals’ metabolite content in the blood, the researchers saw tentative indications of an overall PUFA drop in the body, though this was not nearly as pronounced as in the prelimbic cortex — the part of the brain analyzed in the paper.

“One important distinction between humans and macaques is that we have the alternative of ingesting PUFAs with fish, meat, and some other foods not typically consumed by macaques. They have to rely on their own livers to synthesize PUFAs. This means that if further research determines that the imbalances we observed have to do with disrupted lipid synthesis, this adverse effect could be alleviated in humans with a proper diet,” Tkachev explained.

“For this reason, it is necessary to measure metabolite content in human blood, and the traces of lipid imbalances left in macaque blood give reason to hope we might just find something similar in humans, without the need to actually dissect anyone’s brain,” the researcher went on. “If we don’t, it might be a sign of the imbalances stemming from factors other than synthesis disruptions, such as lipids having trouble entering the brain or possibly undergoing a redistribution toward other brain regions. New animal studies similar to ours but focusing on other brain parts could control for that.”

###

The study reported in this story featured researchers from Skolkovo Institute of Science and Technology, Lomonosov Moscow State University, Max Planck Institute of Psychiatry, Ludwig-Maximilians University, and UC Davis.

Skoltech is a private international university located in Russia. Established in 2011 in collaboration with the Massachusetts Institute of Technology (MIT), Skoltech is cultivating a new generation of leaders in the fields of science, technology, and business, conducting research in breakthrough fields, and promoting technological innovation with the goal of solving critical problems that face Russia and the world. Skoltech is focusing on six priority areas: data science and artificial intelligence, life sciences, advanced materials and modern design methods, energy efficiency, photonics and quantum technologies, and advanced research. Website: https://www.skoltech.ru/.

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JOURNAL

International Journal of Molecular Sciences

DOI

10.3390/ijms22158089 

ARTICLE TITLE

Long-Term Fluoxetine Administration Causes Substantial Lipidome Alteration of the Juvenile Macaque Brain

ARTICLE PUBLICATION DATE

27-Jul-2021

Sin taxes could unintentionally make others pay

Non-targeted taxpayers could suffer unforeseen consequences when excise taxes are imposed

Peer-Reviewed Publication

RENSSELAER POLYTECHNIC INSTITUTE

When an excise tax hike was levied on cigarettes, New York City taxi drivers who smoked were one and a half times more likely to cheat their customers by overcharging the fare than those who didn’t smoke. That finding comes from forthcoming research in Accounting, Organizations, and Society.

In the first-known study to document that sin taxes can even affect those who aren’t paying them, Thomas Shohfi, an assistant professor in the Lally School of Management at Rensselaer Polytechnic Institute, examined detailed, ride-level data of the New York City taxicab market. He studied a four-month period in 2009, before and after the federal tax on cigarettes was raised from $0.39 per pack to $1.01.

Shohfi found that so-called sin taxes, or taxes on substances or activities thought to be sinful or harmful like tobacco use, alcohol, or gambling, resulted in a spillover effect where the individuals targeted by the tax hike — cigarette smokers — defrauded other individuals. 

For more information, watch this video.

In this study, after the federal excise tax hike was placed on cigarettes, the taxi drivers who smoked were more likely to charge riders the “out-of-town” rate for rides fully within New York City limits.

“Taxes often have unintended consequences,” Shohfi said. “One of those unintended consequences, especially with excise taxes, is the potential for people to believe the targeted taxes are unfair, to believe someone else should pay for it, and to change their behavior to make others pay for the increased tax.”

The research provided two distinct reasons for this fraudulent behavior. The first is that tax increases generally reduce the buying power of an individual. They have less money and therefore could have more incentive to cheat. The second reason is that when an individual feels they have been unfairly singled out, it becomes easier to rationalize defrauding others, even when the potential victims have nothing to do with the perceived unfair treatment.

“Fraud erodes trust in the market,” Shohfi said. “Our research shows that when you try to dictate behavior through tax policy, there may be important negative unintended consequences that should be considered.”

This research continues Shohfi’s focus on the use of alternative data as sources of creative and untapped information. Previous studies used information gleaned from earnings conference calls to observe corporate managerial behavior, examined the impact of blockholder charitable donations on market reaction, and analyzed the role of personal characteristics in angel investment decisions.

Shohfi was joined in the research — “Do Sin Taxes Spur Cheating in Interpersonal Exchanges?” — by David Kenchington and Roger White, both of Arizona State University, and Jared Smith from North Carolina State University.

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JOURNAL

Accounting Organizations and Society

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Do Sin Tax Hikes Spur Cheating in Interpersonal Exchange?

ARTICLE PUBLICATION DATE

8-Jul-2021

Disclaimer: AAAS and

SOCIETY BENEFITS FROM REGULATING CAPITALISM

Study: Benefits outweigh risks for autonomous vehicles - if they are regulated

Peer-Reviewed Publication

NORTH CAROLINA STATE UNIVERSITY

An interdisciplinary panel of experts has assessed the risks and potential benefits associated with deploying autonomous vehicles (AVs) on U.S. roads and predicts that the benefits will substantially outweigh potential harms – but only if the AVs are well regulated.

“We wanted to assess the potential harms and benefits associated with AVs and determine what the best implementation strategies would be to minimize harms and maximize benefits,” says Veljko Dubljević, first author of the study and an associate professor in the Science, Technology & Society (STS) program at North Carolina State University.

Deploying AVs onto public roads is a complex social issue, which touches on everything from ethics to transportation engineering to artificial intelligence programming.

“And there aren’t many methods for assessing such complex social problems,” Dubljević says. “One approach is to break the large problem down into a collection of more specific questions, assessing different risks and potential benefits separately. This approach is called multi-criteria decision analysis, and it’s what we did here.”

For this study, the researchers outlined four different scenarios for the future of AVs:

• No AVs allowed on public roads;
• AVs are allowed, with no regulations;
• AVs are allowed, but are regulated;
• AVs are regulated and can only be owned by commercial fleet operators.

The researchers then convened a panel of 19 experts with expertise in subjects such as computer science, political science, transportation and ethics.

The researchers also created a list of 13 potential harms and eight potential benefits associated with deploying AVs. The list was developed based on documents from the National Academies and other federal agencies, as well as input from the expert panel convened for the study. Potential harms included assessments of increased risk of accident deaths or cases of injury. Potential benefits included assessments of economic benefits and curtailing environmental impact by reducing traffic jams.

The expert panel then reviewed the four AV deployment scenarios with the goal of determining which scenarios had the best ratio of benefits to harms.

“To assess the potential impact of AV deployment, you have to compare it to a baseline,” says George List, co-author of the study and a professor of civil engineering at NC State. “The baseline was our current state of affairs. And our current state of affairs is that there are a tremendous number of deaths and injuries on U.S. roads.

“While AVs are not perfect, all of our predictions suggest that they will be a step in the right direction. Prohibiting the use of AVs on U.S. roads was the least promising scenario.”

However, the expert panel also highlighted the extent to which government regulations could help reduce risk.

“For example, regulations could limit use of AVs in urban environments and areas with high pedestrian traffic,” Dubljević says. “Either of the regulated scenarios is better than allowing unregulated AVs on the road.”

So, which scenario offered the most benefits and the fewest risks?

“Regulating AV use and limiting ownership to commercial fleet operators is a little more promising than allowing the general public to own and operate their own AVs,” Dubljević says. That’s because fleet ownership makes it more likely that AVs will be properly maintained, software updates will be made on time, and so on.

“We hope that federal, state and local governments use our findings to review whatever regulations they have in place concerning the use of autonomous vehicles – or to develop regulations if there are none on the books,” Dubljević says.

The study, “Toward a Rational and Ethical Sociotechnical System of Autonomous Vehicles: A Novel Application of Multi-criteria Decision Analysis,” is published in PLOS ONE. The paper was co-authored by William Bauer, an associate teaching professor of philosophy at NC State; Munindar P. Singh, Alumni Distinguished Graduate Professor of Computer Science at NC State; Eleni Bardaka, an assistant professor of civil, construction and environmental engineering at NC State; Thomas Birkland, a professor of public administration at NC State; Roger Mayer, a professor of leadership at NC State; M. Shoaib Samandar, a research associate at NC State; Jovan Milojevich of Oklahoma State University; Nirav Ajmeri of the University of Bristol; Charles Edwards of the University of North Carolina at Chapel Hill; Ioan Muntean of the University of North Carolina at Asheville; Thomas Powers of the University of Delaware; Hesham Rakha of Virginia Tech; and Vance Ricks of Guilford College.

The work was done with support from the Kenan Institute of Science and Technology and North Carolina State University Research and Innovation.

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JOURNAL

PLoS ONE

DOI

10.1371/journal.pone.0256224 

METHOD OF RESEARCH

Content analysis

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Toward a Rational and Ethical Sociotechnical System of Autonomous Vehicles: A Novel Application of Multi-criteria Decision Analysis

ARTICLE PUBLICATION DATE

13-Aug-2021

COI STATEMENT

None.

Using big data to explore the principles of people's online activities globally

What is different or the same about online human connections

Peer-Reviewed Publication

TOYOHASHI UNIVERSITY OF TECHNOLOGY (TUT)

 

IMAGE: THE GLOBAL ACTION AREA MAP SHOWS GEOGRAPHICAL DISPARITIES IN THE USE OF SOCIAL MEDIA DESPITE WORLDWIDE UTILIZATION. view more 

CREDIT: COPYRIGHT (C) TOYOHASHI UNIVERSITY OF TECHNOLOGY. ALL RIGHTS RESERVED.

Overview:

The research team led by Shiori Hironaka, a project assistant professor of Computer Science and Engineering at Toyohashi University of Technology, collected big data on social media in ten countries and analyzed the relationship between connections and the behaviors of people on the Internet. The researchers found that the users had the same characteristics in follow ratios, which reflect the behaviors of users regardless of country. Discovering common characteristics and differences in data that reflects social diversity may help people effectively use data according to their cultural differences, for instance, for marketing and the effective sharing of information.

Details:

The team collected data on the activities of more than 4,000,000 Twitter users in ten countries (Japan, the U.S.A., Brazil, the U.K., Philippines, Turkey, Indonesia, India, Mexico, and Saudi Arabia) and statistically analyzed the online relationships between the connections and behaviors of users. This is the first analysis of this type of data in the world.

The use of social media data for a diverse array of surveys and analyses is becoming more prevalent as more people use social media. This is because social media data is seen as an indirect observation of social situations. However, the nature of the data varies by country due to cultural differences and other factors, even though the data is similarly observed on social media. User behaviors are believed to reflect the cyberculture of the group the user belongs to. Therefore, it is important to know properties of social media in order to use them in various surveys.

The team analyzed the connections between users, focusing on the nearness of the areas where they act. Because the purposes for using social media may be closely connected with the nearness of the action areas of the users who are connected via social media. To be specific, action areas tend to be close if a social media service is used for exchanges with friends. If the purpose is reading celebrities' posts or news, the nearness of action areas does not matter. Having examined the relationship between the nearness of action areas and user behaviors on social media, we compared the characteristics of different countries.

As a result, we identified ten countries with common points regarding user characteristics related to the nearness of action areas. One characteristic is the follow ratio. It is the ratio of those a user is following to the followers of the user. If the follow ratio is high, it is believed that a user is accessed by people wishing to read the user's posts. We also found that the users with longer profiles tend to be farther from the action areas of the connected users. However, the ten countries do not necessarily have this in common.

Essentially, data on social media connections can express information about users around the world in the same way. However, this may not ensure the expected precision for such functions as friend recommendations and attribute estimations as the nature of the data individually differs due to cultural differences. The identified characteristics are expected to help provide the best information to users of different countries and cultures.

###

Future outlook:

The research team will clarify differences between cultures using social media and identify clues for the creation of a next-generation social media outlet by investigating the nature of big data about social media that is observed on social media.

This research project was sponsored by JPMJMI20B4, a JST-Mirai Program.

Reference:

Shiori Hironaka, Mitsuo Yoshida and Kyoji Umemura (2021).

Cross-Country Analysis of User Profiles for Graph-Based Location Estimation.

IEEE Access, doi: 10.1109/ACCESS.2021.308652.

https://ieeexplore.ieee.org/document/9446911

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JOURNAL

IEEE Access

DOI

10.1109/ACCESS.2021.3086523 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Cross-Country Analysis of User Profiles for Graph-Based Location Estimation

ARTICLE PUBLICATION DATE

3-Jun-2021

Pecan-enriched diet shown to reduce cholesterol

People at risk for cardiovascular disease showed improvements

Peer-Reviewed Publication

UNIVERSITY OF GEORGIA

 

IMAGE: GRADUATE STUDENT LIANA GUARNEIRI, LEFT, AND PROFESSOR JAMIE COOPER. view more 

CREDIT: (PHOTO BY ANDREW DAVIS TUCKER/UGA)

While the proper pronunciation of pecan remains a subject of debate, University of Georgia researchers have shown the tree nut can dramatically improve a person’s cholesterol levels.

Participants at risk for cardiovascular disease who ate pecans during an eight-week intervention showed significant improvements in total cholesterol, triglycerides and low-density lipoprotein (LDL), or “bad” cholesterol, in a study conducted by researchers in the UGA College of Family and Consumer Sciences.

“This dietary intervention, when put in the context of different intervention studies, was extremely successful,” said Jamie Cooper, a professor in the FACS department of nutritional sciences and one of the study’s authors. “We had some people who actually went from having high cholesterol at the start of the study to no longer being in that category after the intervention.”

Researchers saw an average drop of 5% in total cholesterol and between 6% and 9% in LDL among participants who consumed pecans.

For context, researchers referred to a previous meta-analysis of 51 exercise interventions designed to lower cholesterol that reported an average reduction of 1% in total cholesterol and 5% in LDL cholesterol.

“The addition of pecans to the diet not only produced a greater and more consistent reduction in total cholesterol and LDL compared to many other lifestyle interventions, but may also be a more sustainable approach for long-term health,” Cooper said. “Some research shows that even a 1% reduction in LDL is associated with a small reduction of coronary artery disease risk, so these reductions are definitely clinically meaningful.”

Researchers assigned 52 adults between the ages of 30 and 75 who were at higher risk for cardiovascular disease to one of three groups.

One group consumed 68 grams or about 470 calories of pecans a day as part of their regular diet; a second group substituted pecans for a similar amount of calories from their habitual diet, and a control group did not consume pecans.

At eight weeks, participants consumed a high-fat meal to determine changes in blood lipids and the amount of glucose, or sugar, in the blood.

Fasted blood lipids showed similar improvements among the two pecan groups while post-meal triglycerides were reduced in the group that added pecans. Post-meal glucose was lowered in the group that substituted pecans.

“Whether people added them or substituted other foods in the diet for them, we still saw improvements and pretty similar responses in total cholesterol and LDL cholesterol in particular,” said Cooper, who also serves as director of the UGA Obesity Initiative.

Researchers pointed to the known bioactive properties of pecans for possible mechanisms driving the improvements.

Pecans are high in healthy fatty acids and fiber, both of which have been linked to lower cholesterol.

The paper, “Pecan-enriched diets alter cholesterol profiles and triglycerides in adults at-risk for cardiovascular disease in a randomized, controlled trial,” appeared in The Journal of Nutrition and can be viewed here: https://academic.oup.com/jn/advance-article/doi/10.1093/jn/nxab248/6349277

Liana Guarneiri, a doctoral student in the FACS department of nutritional sciences, is first author. Chad Paton, associate professor in FACS who has a joint appointment with the College of Agricultural and Environmental Sciences, also is an author.

 

 

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JOURNAL

Journal of Nutrition

ARTICLE TITLE

Pecan-enriched diets alter cholesterol profiles and triglycerides in adults at-risk for cardiovascular disease in a randomized, controlled trial

ARTICLE PUBLICATION DATE

12-Aug-2021

Aerosol from a wide range of vaping devices negatively impacted blood vessel function

American Heart Association Basic Cardiovascular Sciences Meeting Report – Presentation: P355; Session: ePosters

Reports and Proceedings

AMERICAN HEART ASSOCIATION

DALLAS, Aug. 23, 2021 — Aerosol generated from vaping devices likely impairs blood vessels’ ability to function comparable to traditional cigarette smoke, according to preliminary research in rats presented at the American Heart Association’s Basic Cardiovascular Sciences Scientific Sessions 2021. The meeting is virtual, Aug. 23-25, and offers the latest research on basic and translational cardiovascular science.

Vaping, or the use of e-cigarettes, is often promoted as a less harmful alternative to smoking traditional cigarettes. E-cigarettes contain a cartridge with a liquid containing nicotine that generates an aerosol that is inhaled, like smoking a cigarette. Despite the popularity of these devices, knowledge is still limited about the impact of the aerosols from e-cigarettes, heated tobacco products and newer, coil-less, ultrasonic vaping devices on cardiovascular function.

“When you inhale a suspension of particles or a mist, whether it is from tobacco or marijuana, whether it’s smoke or aerosol, it all has the same effect,” said Matthew L. Springer, Ph.D., senior author of the study and a professor of medicine at the University of California, San Francisco School of Medicine. “Our research reinforces the previous findings that vaping is not without harm, and it underscores the importance of counseling patients about the risks of vaping because it does affect cardiovascular function.”

Researchers investigated the impact of aerosols generated from a range of vaping devices on the function of the endothelium, which is a thin membrane lining the inside of the heart and blood vessels. The endothelium is a layer of endothelial cells that produce substances that help control blood clotting, blood pressure levels and immune function and help keep blood vessels healthy. Reduced endothelial function usually precedes the development of atherosclerosis, the build-up of fatty material on arteries, and it is often a predictor of a stroke or heart attack.

In this study, a process known as flow-mediated dilation (FMD), an indicator of endothelial function and overall blood vessel health, was measured by ultrasound. FMD was measured in the rats before and after exposure to the aerosols from each of these:

• propylene glycol (PG),
• vegetable glycerin (VG),
• propylene glycol and vegetable glycerin (PGVG),
• 5% nicotine salt pods of three different flavors (Virginia tobacco, mango and menthol),
• an e-cigarette with free-base nicotine (a previous-generation vaping product),
• a “heat-not-burn” tobacco product, and
• a coil-less ultrasonic vaping device.

Combustible cigarette smoke and clean air were the controls for the study. The researchers sought to determine if aerosols from the different vaping products – regardless of flavor, nicotine amount or method of delivery – diminished blood vessel function. They performed a head-to-head comparison on 11 groups of rats with eight rats in each group, exposing the rats to the nine vaping products, as well as the controls of combustible cigarettes and clean air. The rats were exposed to the products during one session consisting of 10 cycles of 5-second inhalation every 30 seconds over a five-minute period. To measure FMD, the femoral artery, a large artery in the thigh, was measured with a micro-ultrasound.

The study found:

• After only one five-minute session of exposure, endothelial function in the rats was acutely impaired by aerosols from all vaping products. Vessel dilation fell between 40% and 67% for all groups except the rats exposed to the clean air.  
• This blood vessel impairment in vaping products was comparable to the impairment caused by traditional cigarettes (67%).  

The researchers also collected blood from the rats to measure nicotine concentration. They found that the blood-nicotine concentration was 8.7 times higher in the rats exposed to the heated tobacco product (average of 61.4 ng/ml) than in the rats exposed to the ultrasonic vaping device (average of 7.0 ng/ml) and 7.3 times higher than the previous generation of e-cigarette (average of 8.4 ng/ml).

“We were not surprised when we saw the results for the heated tobacco products and previous generation e-cigarettes, however, we were somewhat surprised to discover that the new ultrasonic vaping device also impaired flow-mediated dilation,” said study lead author Poonam Rao, M.D., a postdoctoral fellow at the Center for Tobacco Control Research and Education at the University of California, San Francisco. “This new ultrasonic device has no heating coil, so theoretically it should be safer than e-cigarettes. Yet even without the intense heating of the nicotine substance, this aerosol impaired vascular function like all of the other products.”

While these results are from an animal experiment, they are applicable to humans. “The approach we used to study vascular function in the rats closely resembles what happens in humans. This is a rodent-equivalent of a common clinical measure in humans in the brachial artery, the major blood vessel of the (upper) arm,” Springer said. “It is known that e-cigarettes can impair vascular function in humans. If any mist or aerosol that rats inhale has this adverse effect, it will likely happen in humans, too.”

Co-authors are Kelly Tan; Daniel D. W. Han, B.A.; and Ronak Derakhshandeh, M.Sc. Author disclosures are in the abstract. The study was funded by the U.S. Food and Drug Administration, the National Institutes of Health and the Elfenworks Foundation.

Additional Resources:

• Multimedia is available on the right column of the news release link https://newsroom.heart.org/news/aerosol-from-a-wide-range-of-vaping-devices-negatively-impacted-blood-vessel-function?preview=71ed2c0dfeba1886e5e868d1e74b624e
• American Heart Association Presidential Advisory: New and Emerging Tobacco Products and the Nicotine Endgame
• The science about vaping dangers – and what we don’t know yet
• Vaping combined with smoking is likely as harmful as smoking cigarettes alone
• Follow AHA/ASA news from the meeting on Twitter @HeartNews, #BCVS21

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The American Heart Association’s Basic Cardiovascular Sciences Scientific Sessions (BCVS) is the world’s premier meeting dedicated to the latest advances in basic and translational cardiovascular science. The virtual meeting is Monday-Wednesday, Aug. 23-25, 2021. The primary goal of the meeting is to convene scientists from around the world with the common goal to discover pathways to cardiovascular therapeutics and promoting cardiovascular health. Sessions are focused on new therapies and insights in cardiovascular disease, as well as research in fields like microRNAs, cardiac gene and cell therapy, cardiac development, as well as tissue engineering and iPS cells. The BCVS 2021 Scientific Sessions program, planned by the American Heart Association’s Council on Basic Cardiovascular Sciences, is of special interest to basic cardiovascular scientists, molecular/ cellular biologists, physiologists, translational investigators, clinical trialists, practicing cardiologists, cardiovascular nurses and pharmacists. Follow the conference on Twitter at #BCVS21.

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