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Scientists track gene activity when honey bees do and don’t eat honey: Significant differences depending on diet

Many beekeepers feed their honey bees sucrose or high-fructose corn syrup when times are lean inside the hive. This practice has come under scrutiny, however, in response to colony collapse disorder, the massive — and as yet not fully explained — annual die-off of honey bees in the U.S. and Europe. Some suspect that inadequate nutrition plays a role in honey bee declines.

In a new study, described in Scientific Reports, researchers took a broad look at changes in gene activity in response to diet in the Western honey bee (Apis mellifera), and found significant differences occur depending on what the bees eat.

The researchers looked specifically at an energy storage tissue in bees called the fat body, which functions like the liver and fat tissues in humans and other vertebrates.

“We figured that the fat body might be a particularly revealing tissue to examine, and it did turn out to be the case,” said University of Illinois entomology professor and Institute for Genomic Biology director Gene Robinson, who performed the new analysis together with entomology graduate student Marsha Wheeler.

The researchers limited their analysis to foraging bees, which are older, have a higher metabolic rate and less energy reserves (in the form of lipids stored in the fat body) than their hive-bound nest mates — making the foragers much more dependent on a carbohydrate-rich diet, Robinson said.

“We reasoned that the foragers might be more sensitive to the effects of different carbohydrate sources,” he said.

The researchers focused on gene activity in response to feeding with honey, high-fructose corn syrup (HFCS), or sucrose. They found that those bees fed honey had a very different profile of gene activity in the fat body than those relying on HFCS or sucrose. Hundreds of genes showed differences in activity in honey bees consuming honey compared with those fed HFCS or sucrose. These differences remained even in an experimental hive that the researchers discovered was infected with deformed wing virus, one of the many maladies that afflict honey bees around the world.

“Our results parallel suggestive findings in humans,” Robinson said. “It seems that in both bees and humans, sugar is not sugar — different carbohydrate sources can act differently in the body.”

Some of the genes that were activated differently in the honey-eating bees have been linked to protein metabolism, brain-signaling and immune defense. The latter finding supports a 2013 study led by U. of I. entomology professor and department head May Berenbaum, who reported that some substances in honey increase the activity of genes that help the bees break down potentially toxic substances such as pesticides.

“Our results further show honey induces gene expression changes on a more global scale, and it now becomes important to investigate whether these changes can affect bee health,” Robinson said.

Story Source:

The above story is based on materials provided by University of Illinois at Urbana-Champaign. Note: Materials may be edited for content and length.

Agriculture and Food News — ScienceDaily

QUAFETY Project: differences found in microbial development in fresh-cut produce

QUAFETY Project: differences found in microbial development in fresh-cut produce

Fresh products eaten raw and minimally processed are important components of a daily diet. However, raw vegetables can harbour many microorganisms, which may be spread during washing, cutting or peeling prior to the commercial distribution. The microbial growth increases during storage. Microorganisms are the cause of food decay and reduce shelf life of fresh-cut vegetables, and potentially may be a source of foodborne illness.

Polish scientists, within European Project Quafety, have found that various vegetables are more or less predisposed for fresh cut market because of strong differences in microbial development depending on processing and storage conditions. The growth of several groups of microorganisms in fresh-cut Chinese cabbage, rocket and melon stored at different temperature regimes were investigated.

The samples of cabbage or melon were cut into small pieces. Half of them was washed in tap water. Fresh rocket leaves were not washed or washed in the water. Then, plant material was packed into polystyrene foam trays and put in plastic containers lined with polyethylene film. Fresh, unprocessed and unwashed samples were used as control.

Cabbage was stored at 18-20°C for 3 days, at 0°C and at 5°C for 7 days.
Rocket was stored at 18-20°C for 4 days, at 1°C and at 5°C for 10 days.
Melon was stored at 18-20°C for 2 days, at 0°C and at 5°C for 5 days.
Microbial analyses consist in the count of mesophilic bacteria, coliforms, Escherichia coli, moulds and yeasts.

In all experiments, cutting and washing operations did not affect the number of microorganisms before storage.

Washing did not reduced the density of microbial cells on plants; however, washing and cutting operations caused significant increase of microorganisms during storage.
The highest growth of bacteria and moulds and yeasts was detected in melon. The number of mesophilic bacteria increased thousands fold, especially in cut and washed samples, in all storage conditions tested. The same was noticed for yeasts. It indicated that melons are not appropriate fruits to prepare as fresh-cut product, because the rapid growth of microorganisms in this material may cause quick food decay and reduced safety of such product.

In the case of rocket, the number of microorganisms increased significantly at all storage temperatures tested. It resulted very variable in terms of microbial groups detected suggesting that rocket is not stabile. Moreover, storing the leaves for longer time, even at low temperatures, caused high growth of coliforms.

The most predisposed for the market as ready-to-eat product seems to be Chinese cabbage. For this vegetable cutting of the leaves was the main factor stimulating microbial growth but lower temperatures (1 – 5 oC) restrained this process, and especially yeasts and coliforms development. 

In all experiments and in all vegetable species E. coli was not detected.

For further info contact:
Magdalena Szczech
Research Institute of Horticulture
Skierniewice, Poland
Email: [email protected]

Publication date: 6/5/2014
Author: Emanuela Fontana
Copyright: www.freshplaza.com


FreshPlaza.com

‘Rice theory’ explains north-south China cultural differences

A new cultural psychology study has found that psychological differences between the people of northern and southern China mirror the differences between community-oriented East Asia and the more individualistic Western world — and the differences seem to have come about because southern China has grown rice for thousands of years, whereas the north has grown wheat.

“It’s easy to think of China as a single culture, but we found that China has very distinct northern and southern psychological cultures and that southern China’s history of rice farming can explain why people in southern China are more interdependent than people in the wheat-growing north,” said Thomas Talhelm, a University of Virginia Ph.D. student in cultural psychology and the study’s lead author. He calls it the “rice theory.” The findings appear in the May 9 issue of the journal Science.

Talhelm and his co-authors at universities in China and Michigan propose that the methods of cooperative rice farming — common to southern China for generations — make the culture in that region interdependent, while people in the wheat-growing north are more individualistic, a reflection of the independent form of farming practiced there over hundreds of years.

“The data suggests that legacies of farming are continuing to affect people in the modern world,” Talhelm said. “It has resulted in two distinct cultural psychologies that mirror the differences between East Asia and the West.”

According to Talhelm, Chinese people have long been aware of cultural differences between the north region and the southern, which are divided by the Yangtze River — the largest river in China, flowing west to east across the vast country. People in the north are thought to be more aggressive and independent, while people to the south are considered more cooperative and interdependent.

“This has sometimes been attributed to different climates — warmer in the south, colder in the north — which certainly affects agriculture, but it appears to be more related to what Chinese people have been growing for thousands of years,” Talhelm said.

He notes that rice farming is extremely labor-intensive, requiring about twice the number of hours from planting to harvest as does wheat. And because most rice is grown on irrigated land, requiring the sharing of water and the building of dikes and canals that constantly require maintenance, rice farmers must work together to develop and maintain an infrastructure upon which all depend. This, Talhelm argues, has led to the interdependent culture in the southern region.

Wheat, on the other hand, is grown on dry land, relying on rain for moisture. Farmers are able to depend more on themselves, leading to more of an independent mindset that permeates northern Chinese culture.

Talhelm developed his rice theory after living in China for four years. He first went to the country in 2007 as a high school English teacher in Guangzhou, in the rice-growing south.

A year later, he moved to Beijing, in the north. On his first trip there, he noticed that people were more outgoing and individualistic than in the south.

“I noticed it first when a museum curator told me my Chinese was clearly better than my roommate’s,” Talhelm said. “The curator was being direct and a little less concerned about how her statement might make us feel.”

After three years in China, including time as a journalist, he later went back as a U.Va. doctoral student on a Fulbright scholarship.

“I was pretty sure the differences I was seeing were real, but I had no idea why northern and southern China were so different — where did these differences come from?” Talhelm asked.

He soon found that the Yangtze was an important cultural divider in China. “I found out that the Yangtze River helped divide dialects in China, and I soon learned that the Yangtze also roughly divides rice farming and wheat farming,” he said.

He dug into anthropologists’ accounts of pre-modern rice and wheat villages and realized that they might account for the different mindsets, carried forward from an agrarian past into modernity.

“The idea is that rice provides economic incentives to cooperate, and over many generations, those cultures become more interdependent, whereas societies that do not have to depend on each other as much have the freedom of individualism,” Talhelm said. He went about investigating this with his Chinese colleagues by conducting psychological studies of the thought styles of 1,162 Han Chinese college students in the north and south and in counties at the borders of the rice-wheat divide.

They found through a series of tests that northern Chinese were indeed more individualistic and analytic-thinking — more similar to Westerners — while southerners were interdependent, holistic-thinking and fiercely loyal to friends, as psychological testing has shown is common in other rice-growing East Asian nations, such as Japan and Korea.

The study was conducted in six Chinese cities: Beijing in the north; Fujian in the southeast; Guangdong in the south; Yunnan in the southwest; Sichuan in the west central; and Liaoning in the northeast.

Talhelm said that one of the most striking findings was that counties on the north-south border — just across the Yangtze River from each other — exhibited the same north/south psychological characteristics as areas much more distantly separated north and south. “I think the rice theory provides some insight to why the rice-growing regions of East Asia are less individualistic than the Western world or northern China, even with their wealth and modernization,” Talhelm said.

He expects to complete his Ph.D. next year, and this year received an Arts, Humanities and Social Sciences Research Fellowship from U.Va.’s Office of the Vice President for Research and the Graduate School of Arts & Sciences for an in-depth study of people from the rice-wheat border in China’s Anhui province. 

Agriculture and Food News — ScienceDaily

Obesity Study Examines Gender Differences of 6th Graders

Eating school lunches and watching too much television are contributing to the obesity of Michigan 6th graders, according to cardiovascular researchers. The University of Michigan Frankel Cardiovascular Center came to those conclusions after studying data on 1,714 6th graders from 20 schools in four communities in the southeast area of the state.

The findings will be published in the September issue of Pediatrics.

While eating school lunches and watching more than two hours of television a day were obesity contributors, according to the study, girls drinking two milk servings a day and boys who were active in sports were activities found to result in healthier weights.

“Additional work is needed to help us understand the beneficial impact of improving school lunches and decreasing screen time,” says cardiologist and senior study author Elizabeth Jackson, M.D., M.P.H., assistant professor of internal medicine at the University of Michigan Medical School. “Presumably playing video games or watching TV replaces physical activity.”

The median age of those in the study was 11.

Obese boys and girls had poor cardiovascular profiles with lower HDL-cholesterol, higher triglycerides, higher blood pressure and higher heart rate recovery – indicating a lower level of fitness – compared to normal-weight kids.

“Cardiovascular disease doesn’t just start in adulthood, and there may be factors that could help us identify during youth or adolescence who might be at increased risk for developing health problems later on,” Jackson says.

Other studies have linked eating school lunch with obesity, but a major issue with such studies, Jackson says, is the influence of socioeconomic status. Poor children eligible for free or reduced school lunch may already be overweight, considering the link between obesity and lower socioeconomic status.

“Although we were not able to examine the specific nutritional content of school lunches, previous research suggests school lunches include nutrient-poor and calorie-rich foods,” Jackson says.

Authors of the study say the findings provide “a real-world view of the gender differences in obesity risk factors.”

Girls in general were significantly less likely to report being physically active. One possible explanation, authors say, is the potential for activities such as dance or cheerleading not considered by children to be sports, and such activities are more prevalent among girls.

Milk consumption seemed to protect girls from obesity, but made no difference for boys. A possible explanation would be a reduction in sugary drinks, which girls replaced with milk.

In the study, 61 percent of obese boys and 63 percent of obese girls reported watching television for two or more hours a day. The assumption is that watching television mediates physical activity, but there were gender differences in how children spent their so-called “screen time.”

When asked, obese girls were more likely than any other group to use a computer. Obese boys reported playing video games more often than normal-weight boys, although the association was not as strong as in other studies.

“We did not find a significant association between time spent playing video games and obesity among boys, which has been observed in other studies,” says study lead author Morgen Govindan, an investigator with the Michigan Cardiovascular Research and Reporting Program at the UM. “Although we saw a similar trend, the association was not as strong, perhaps due to our smaller sample size.”

She adds: “Exploring such gender-related differences in a larger group may help in refining the interventions to promote weight loss and prevent obesity among middle-school children. The Project Healthy Schools program is designed to teach 6th graders heart-healthy lifestyles, including eating more fruits and vegetables, making better beverage choices, engaging in 150 minutes of exercise per week, eating less fast food and less fatty foods, plus reducing time spent in front of computer and video game screens.”

Multiple sources of funding support Project Healthy Schools research in Michigan including: the University of Michigan Health System, the Thompson Foundation, the Hewlett Foundation, the Mardigian Foundation, the Memorial Healthcare Foundation, the William Beaumont Health System Foundation, the Robert C. Atkins Foundation, the Ann Arbor Area Community Foundation, the Allen Foundation, AstraZeneca, HealthCare Foundation, Borders Inc, and the Robert Beard Foundation.

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