New Capsicum annuum pepper contains high concentrations of beneficial capsinoids

Researchers have released a new Capsicum annuum pepper germplasm that contains high concentrations of capsinoids. The release was announced in the January 2014 issue of HortScience by researchers Robert L. Jarret from the USDA/Agricultural Research Service in Griffin, Georgia, in collaboration with Jason Bolton and L. Brian Perkins from the Department of Food Science and Human Nutrition at the University of Maine.According to the report, the germplasm called “509-45-1” is a small-fruited Capsicum annuum L. pepper. Fruit of 509-45-1 contain high concentrations of capsiate in both immature and mature fruit. “The release of 509-45-1 will provide researchers and plant breeders with a new source of capsinoids, thus facilitating the production of and further research on these non-pungent biologically active compounds,” Jarret said.Pungent capsaicinoids–the compounds found in the capsicum family of plants that give them their signature heat–have many benefits. Unfortunately, their use as ingredients in foods and pharmaceuticals has been limited by the very characteristic that makes them popular as a spice–their pungency. Non-pungent capsinoids, analogs of capsaicinoids, were first isolated from a sweet pepper cultivar. Capsinoids offer similar types of biological activity as capsaicinoids without the pungency, and are known to provide antioxidant activity, enhance adrenal function, promote metabolism, and suppress body fat accumulation.The scientists began the breeding process in 2005 by screening 120 Capsicum annuum cultivars for the occurrence of capsinoids. …

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How to avoid weight gain while traveling

Learn more about Herbalife – Follow @Herbalife on Twitter- Like Herbalife on Facebook- What is Herbalife? More fitness advice – Watch ‘Fit Tips’ Videos on YouTube- Straightforward exercise advice- Get fit = be happy. Positivity advice Nutrition advice for you – Watch ‘Healthy Living’ on YouTube- Dieting advice you might like- Interesting weight loss articles Copyright © 2013 Herbalife International of America, Inc.

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What singing fruit flies can tell us about quick decisions

You wouldn’t hear the mating song of the male fruit fly as you reached for the infested bananas in your kitchen. Yet, the neural activity behind the insect’s amorous call could help scientists understand how you made the quick decision to pull your hand back from the tiny swarm.Male fruit flies base the pitch and tempo of their mating song on the movement and behavior of their desired female, Princeton University researchers have discovered. In the animal kingdom, lusty warblers such as birds typically have a mating song with a stereotyped pattern. A fruit fly’s song, however, is an unordered series of loud purrs and soft drones made by wing vibrations, the researchers reported in the journal Nature. A male adjusts his song in reaction to his specific environment, which in this case is the distance and speed of a female — the faster and farther away she’s moving, the louder he “sings.”While the actors are small, the implications of these findings could be substantial for understanding rapid decision-making, explained corresponding author Mala Murthy, a Princeton assistant professor of molecular biology and the Princeton Neuroscience Institute. Fruit flies are a common model for studying the systems of more advanced beings such as humans, and have the basic components of more complex nervous systems, she said.The researchers have provided a possible tool for studying the neural pathways behind how an organism engaged in a task adjusts its behavior to sudden changes, be it a leopard chasing a zigzagging gazelle, or a commuter navigating stop-and-go traffic, Murthy said. She and her co-authors created a model that could predict a fly’s choice of song in response to its changing environment, and identified the neural pathways involved in these decisions.”Here we have natural courtship behavior and we have this discovery that males are using information about their sensory environment in real time to shape their song. That makes the fly system a unique model to study decision-making in a natural context,” Murthy said.”You can imagine that if a fly can integrate visual information quickly to modulate his song, the way in which it does that is probably a very basic equivalent of how a more complicated animal solves a similar problem,” she said. “To figure out at the level of individual neurons how flies perform sensory-motor integration will give us insight into how a mammalian brain does it and, ultimately, maybe how a human brain does it.”Aravi Samuel, a Harvard University professor of neuroscience who studies the brain and behavior using roundworms and fruit fly larvae, said that the researchers conducted the kind of “rigorous” behavioral analysis that is essential to understanding the brain’s circuitry.”Neuroscience isn’t just making electrical recordings of circuits or finding molecules that affect circuit properties,” said Samuel, who is familiar with the research but had no role in it. “It also is about understanding the behavior itself, from sensory input to motor output. …

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Serious side effect: Several FDA-approved anti-cancer drugs induce stem cell tumors

Using a new approach to systematically test chemotherapy drugs in an unusual animal model, a research team led by University of Massachusetts Amherst molecular biologist Michele Markstein, with Norbert Perrimon at Harvard Medical School, report that several have a serious side effect: Inducing hyper proliferation in stem cells that could lead to tumor recurrence.Markstein says, “We discovered that several chemotherapeutics that stop fast growing tumors have the opposite effect on stem cells in the same animal, causing them to divide too rapidly. This was a surprise, because it showed that the same drug could have opposite actions on cells in the same animal: Suppressing tumor growth on one cell population while initiating growth in another. Not only is the finding of clinical interest, but with this study we used an emerging new non-traditional tool for assessing drugs using stem cells in the fruit fly gut.”She adds, “We did these experiments in the fly because Drosophila stem cells, in the intestine, are very much like the stem cells in our intestine, and it’s a lot easier to do experiments in flies than humans or even mice.”Further, Markstein explains, “When it comes to stem cells, it is important to conduct studies in living animals because stem cells are acutely attuned to the other cells in their microenvironment. Indeed the side effect that we observed is caused by damage that the chemotherapy drugs to cells in the stem cell microenvironment. The stem cells respond to this damage by hyper proliferating.”Markstein and Samantha Dettorre at UMass, with Perrimon and colleagues at Harvard Medical School, pioneered large-scale chemical screening in adult fruit flies that they feel will be useful for testing other chemicals. Conventional in vitro cell screens can identify drugs that act directly on stem cells, the authors note, but they cannot test and identify drugs that act on the all-important microenvironment, which provides cues for stem cell division, differentiation, and death.The flies provide “ready-made stem cell microenvironments” that are “difficult-to-impossible” to create in petri dishes, Markstein notes. Specifically, she and her colleagues inserted a human cancer-causing gene in the fly genome, turned on that gene in its intestinal stem cells, and found that it did form fast-growing tumors.To take full advantage of Drosophila’s ready-made microenvironments, they developed new technology to determine the size of tumors inside each fly gut. The previous standard in the field was to dissect flies to visualize tumors, which are typically labeled green with green fluorescent protein. In the new method, the researchers decided to use a different label, an enzyme from fireflies called luciferase. This allows them to measure tumor size simply by crushing the flies en masse, rather than dissecting them one-by-one.They asked the National Cancer Institute for chemotherapy drug samples and received a library of 88 currently in clinical use. …

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New school meal standards significantly increase fruit, vegetable consumption

New federal standards launched in 2012 that require schools to offer healthier meals have led to increased fruit and vegetable consumption, according to a new study from Harvard School of Public Health (HSPH) researchers. The study, the first to examine school food consumption both before and after the standards went into effect, contradicts criticisms that the new standards have increased food waste.”There is a push from some organizations and lawmakers to weaken the new standards. We hope the findings, which show that students are consuming more fruits and vegetables, will discourage those efforts,” said lead author Juliana Cohen, research fellow in the Department of Nutrition at HSPH.Some 32 million students eat school meals every day; for many low-income students, up to half their daily energy intake is from school meals. Under the previous dietary guidelines, school breakfasts and lunches were high in sodium and saturated fats and were low in whole grains and fiber. The new standards from the United States Department of Agriculture (USDA) aimed to improve the nutritional quality of school meals by making whole grains, fruits, and vegetables more available, requiring the selection of a fruit or vegetable, increasing the portion sizes of fruits and vegetables, removing trans fats, and placing limits on total calories and sodium levels.The researchers collected plate waste data among 1,030 students in four schools in an urban, low-income school district both before (fall 2011) and after (fall 2012) the new standards went into effect. Following the implementation of the new standards, fruit selection increased by 23.0%; entre and vegetable selection remained unchanged. In addition, consumption of vegetables increased by 16.2%; fruit consumption was unchanged, but because more students selected fruit, overall, more fruit was consumed post-implementation.Importantly, the new standards did not result in increased food waste, contradicting anecdotal reports from food service directors, teachers, parents, and students that the regulations were causing an increase in waste due to both larger portion sizes and the requirement that students select a fruit or vegetable. However, high levels of fruit and vegetable waste continued to be a problem — students discarded roughly 60%-75% of vegetables and 40% of fruits on their trays. The authors say that schools must focus on improving food quality and palatability to reduce waste.”The new school meal standards are the strongest implemented by the USDA to date, and the improved dietary intakes will likely have important health implications for children,” wrote the researchers.Story Source:The above story is based on materials provided by Harvard School of Public Health. Note: Materials may be edited for content and length.

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Fruit flies reveal normal function of gene mutated in spinocerebellar ataxia type 7

Disruptive clumps of mutated protein are often blamed for clogging cells and interfering with brain function in patients with the neurodegenerative diseases known as spinocerebellar ataxias. But a new study in fruit flies suggests that for at least one of these diseases, the defective proteins may not need to form clumps to do harm.The study, published February 1, 2014, in the journal Genes and Development, focuses on ataxin-7, the gene that is mutated in patients with spinocerebellar ataxia type 7 (SCA-7). Researchers led by investigators Jerry Workman, Ph.D. and Susan Abmayr, Ph.D. at the Stowers Institute for Medical Research found that fruit flies that lack Ataxin-7 experience neurodegeneration in the brain and the eye — paralleling the effects of the human disease. “The assumption has been that the disease is caused by the aggregated proteins,” Workman says. “But in the mutated fly, there’s no aggregated protein. There’s no soluble protein. It’s not there at all. The lack of Ataxin-7 causes neurodegeneration in the fruit fly.”Workman and Abmayr did not set out to study Ataxin-7. …

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Chemo delayed due to platelets low

Yesterday (Tuesday) we made the round trip to Melbourne (170kms) to have my third dose of chemotherapy treatment Gemzar in day chemo ward at John Fawkner Hospital. Day chemo greeted us like old friends – this is my third round in 10 years and most of the staff are still there making patients and family very welcome. We have become very friendly with some of the staff over the years and always drop in when visiting the hospital.My PICC line was dressed, it is slightly bruised, however due to being a week old this is pretty normal. Bloods taken, Keith took them to pathology (next door building) while I made my way across to see the oncologist … he said ‘very heavy dose of cisplatin/gemzar last week – …

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New micro water sensor can aid growers

Oct. 15, 2013 — Crop growers, wine grape and other fruit growers, food processors and even concrete makers all benefit from water sensors for accurate, steady and numerous moisture readings. But current sensors are large, may cost thousands of dollars and often must be read manually.Now, Cornell University researchers have developed a microfluidic water sensor within a fingertip-sized silicon chip that is a hundred times more sensitive than current devices. The researchers are now completing soil tests and will soon test their design in plants, embedding their “lab on a chip” in the stems of grape vines, for example. They hope to mass produce the sensors for as little as $5 each.In soil or when inserted into a plant stem, the chip is fitted with wires that can be hooked up to a card for wireless data transmission or is compatible with existing data-loggers. Chips may be left in place for years, though they may break in freezing temperatures. Such inexpensive and accurate sensors can be strategically spaced in plants and soil for accurate measurements in agricultural fields.For example, sophisticated vintners use precise irrigation to put regulated water stress on grapevines to create just the right grape composition for a premium cabernet or a chardonnay wine. While growers can use the sensors to monitor water in soils for their crops, civil engineers can embed these chips in concrete to determine optimal moisture levels as the concrete cures.”One of our goals is to try and develop something that is not only a great improvement, but also much cheaper for growers and others to use,” said Alan Lakso, professor of horticulture, who has been working on water sensing for 20 years.The sensors make use of microfluidic technology — developed by Abraham Stroock, associate professor of chemical and biomolecular engineering — that places a tiny cavity inside the chip. The cavity is filled with water, and then the chip may be inserted in a plant stem or in the soil where it, through a nanoporous membrane, exchanges moisture with its environment and maintains an equilibrium pressure that the chip measures.Using chips embedded in plants or spaced across soil and linked wirelessly to computers, for example, growers may “control the precise moisture of blocks of land, based on target goals,” said Vinay Pagay, who helped develop the chip as a doctoral student in Lakso’s lab.Ernest and Julio Gallo Winery and Welch’s juice company have already expressed interest in the sensors. And Cornell civil engineer Ken Hover has started working with Pagay and Lakso on using the sensors in concrete.The researchers seek to understand how values gathered from sensors inside a plant and in soils relate to plant growth and function, so that growers can translate sensor values and optimize management.The Cornell Center for Technology Enterprise and Commercialization is handling the intellectual property rights and patents.

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‘Merlin’ is a matchmaker, not a magician

Sep. 11, 2013 — Johns Hopkins researchers have figured out the specific job of a protein long implicated in tumors of the nervous system. Reporting on a new study described in the Sept. 12 issue of the journal Cell, they detail what they call the “matchmaking” activities of a fruit fly protein called Merlin, whose human counterpart, NF2, is a tumor suppressor protein known to cause neurofibromatosis type II when mutated.Merlin (which stands for Moesin-Ezrin-Radixin-Like Protein) was already known to influence the function of another protein, dubbed Hippo, but the particulars of that relationship were unclear. “Now we’ve shown how Merlin and Hippo interact to begin a chain of events that controls the growth of many tissues,” says Duojia Pan, Ph.D., professor of molecular biology and genetics at the Johns Hopkins University School of Medicine and a Howard Hughes Medical Institute investigator. “This insight is important because not only do malfunctions in that chain of events affect growth and development, they can also lead to cancer and other tumors.”Ten years ago, Pan and his research group discovered Hippo, a gene responsible for keeping body parts proportional to the overall size of the fruit fly. They called it Hippo because the absence of the gene, and the protein it codes for, causes fruit flies to develop unusually large and furrowed organs. Since then, they have been working to understand Hippo and all of the proteins in its network that help control organ size.Previous work by others suggested that Merlin may be part of the Hippo network, but it was not known how Merlin fits into the network. In the new study, Pan and his team used a combination of genetics, cell biology and biochemistry to demonstrate that Merlin acts as a matchmaker, helping Hippo find its target protein, known as Warts, by keeping Warts in the right part of the cell.Without Merlin around, inactive copies of Warts would float around in the watery interior of the cell while Hippo waited near the outer envelope of the cell. Merlin, also located near the outer envelope of the cell, arranges their meetings by connecting to Warts so that Warts, too, ends up near the outer envelope, where Hippo then turns it on. …

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Commercial baby foods don’t meet infants’ weaning needs

Sep. 9, 2013 — UK commercial baby foods don’t meet infants’ dietary weaning needs, because they are predominantly sweet foods that provide little extra nutritional goodness over breast milk, indicates research published online in Archives of Disease in Childhood.Furthermore, they are promoted for infants from the age of four months — an age when they should still be on an exclusive breast milk diet, say the researchers.They wanted to find out what sort of products are available in the UK for weaning infants from a predominantly milk based diet to a family food based diet, and to assess their nutritional value.The weaning process aims to introduce infants to a wider range of tastes, textures, and flavours, to encourage them to accept different foods, and to boost their energy and nutrient intake.UK government recommendations on weaning foods stipulate that these should be introduced gradually, starting with cereals, vegetables and fruits, followed by protein-rich foods and should not be started before six months, in line with recommendations for exclusive breastfeeding until that time.The authors therefore analysed the nutritional content of all infant foods intended for weaning and produced by four major UK manufacturers and two specialist suppliers between October 2010 and February 2011.The products included ready-made soft, wet foods, powdered meals to be reconstituted with milk or water, breakfast cereals, and finger foods, such as rusks.The authors collected their information on the calorie density, added salt and sugar, and the protein, iron, calcium, and carbohydrate content, from the manufacturers’ websites, labels on products in store, and via direct email inquiry.Most (79%) of the 462 stand-alone products assessed were ready made spoonable foods, almost half of which (44%; 201) were aimed at infants from the age of four months onwards.Analysis of the 410 spoonable foods revealed that their energy content (282 kiloJoules per 100 grams) was almost identical to that of breast milk (283kJ/100g). And their protein content was only 40% higher than formula milk.Products containing meat had the highest iron content, but this was again no higher than formula milk, and not much higher than products that did not contain meat.Dry finger foods had a much higher energy and nutrient density overall, but they were also particularly high in sugar.Around two thirds (65%) of the stand-alone products were sweet foods. Babies have an innate preference for sweet foods, which might explain why sweet ingredients feature so prominently in commercial products, say the authors.”However, repeated exposure to foods during infancy promotes acceptance and preferences,” they write, and the inclusion of fruit sugars rather than refined sugars won’t make any difference in terms of the risk of tooth decay, they say.The nutritional content of the shop-bought products was compared with that of typical family home-made foods commonly given to infants and toddlers.The savoury ready-made spoonable foods generally had much lower nutrient density than typical home-made foods, with the exception of iron content.But it still means that 50g of a spoonable family food would probably supply the same amount of energy and protein as 100g of a similar commercial product, say the authors.They emphasise that the main point of weaning foods is to increase the energy content of the diet and provide richer sources of nutrients, such as iron.”Yet the most commonly used commercial foods considered in this study supply no more energy than breast or formula milk” and yet they are promoted at an age when they will replace the breast (or formula milk), which is all that babies under six months really need, they explain.”While it is understandable that parents may choose to use [these products] early in the weaning process, health professionals should be aware that such food will not add to the nutrient density of a milk diet,” they conclude.

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A fly’s hearing: Fruit fly is ideal model to study hearing loss in people

Sep. 2, 2013 — If your attendance at too many rock concerts has impaired your hearing, listen up.University of Iowa researchers say that the common fruit fly, Drosophila melanogaster, is an ideal model to study hearing loss in humans caused by loud noise. The reason: The molecular underpinnings to its hearing are roughly the same as with people.As a result, scientists may choose to use the fruit fly to quicken the pace of research into the cause of noise-induced hearing loss and potential treatment for the condition, according to a paper published this week in the online Early Edition of the journal Proceedings of the National Academy of Sciences.”As far as we know, this is the first time anyone has used an insect system as a model for NIHL (noise-induced hearing loss),” says Daniel Eberl, UI biology professor and corresponding author on the study.Hearing loss caused by loud noise encountered in an occupational or recreational setting is an expensive and growing health problem, as young people use ear buds to listen to loud music and especially as the aging Baby Boomer generation enters retirement. Despite this trend, “the molecular and physiological models involved in the problem or the recovery are not fully understood,” Eberl notes.Enter the fruit fly as an unlikely proxy for researchers to learn more about how loud noises can damage the human ear. Eberl and Kevin Christie, lead author on the paper and a post-doctoral researcher in biology, say they were motivated by the prospect of finding a model that may hasten the day when medical researchers can fully understand the factors involved in noise-induced hearing loss and how to alleviate the problem. The study arose from a pilot project conducted by UI undergraduate student Wes Smith, in Eberl’s lab.”The fruit fly model is superior to other models in genetic flexibility, cost, and ease of testing,” Christie says.The fly uses its antenna as its ear, which resonates in response to courtship songs generated by wing vibration. The researchers exposed a test group of flies to a loud, 120 decibel tone that lies in the center of a fruit fly’s range of sounds it can hear. This over-stimulated their auditory system, similar to exposure at a rock concert or to a jack hammer. Later, the flies’ hearing was tested by playing a series of song pulses at a naturalistic volume, and measuring the physiological response by inserting tiny electrodes into their antennae. The fruit flies receiving the loud tone were found to have their hearing impaired relative to the control group.When the flies were tested again a week later, those exposed to noise had recovered normal hearing levels. …

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Motional layers found in the brain: Neurobiologists discover elementary motion detectors in the fruit fly

Aug. 7, 2013 — Recognising movement and its direction is one of the first and most important processing steps in any visual system. By this way, nearby predators or prey can be detected and even one’s own movements are controlled. More than fifty years ago, a mathematical model predicted how elementary motion detectors must be structured in the brain. However, which nerve cells perform this job and how they are actually connected remained a mystery. Scientists at the Max Planck Institute of Neurobiology in Martinsried have now come one crucial step closer to this “holy grail of motion vision”: They identified the cells that represent these so-called “elementary motion detectors” in the fruit fly brain. The results show that motion of an observed object is processed in two separate pathways. In each pathway, motion information is processed independently of one another and sorted according to its direction.Ramón y Cajal, the famous neuroanatomist, was the first to examine the brains of flies. Almost a century ago, he thus discovered a group of cells he described as “curious elements with two tufts.” About 50 years later, German physicist Werner Reichardt postulated from his behavioural experiments with flies that they possess “elementary motion detectors,” as he referred to them. These detectors compare changes in luminance between two neighbouring photoreceptor units, or facets, in the fruit fly’s eye for every point in the visual space. …

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The temperature tastes just right

Aug. 7, 2013 — Call it the Goldilocks Principle — animals can survive and reproduce only if the temperature is just right. Too hot and they will overheat. Too cold and they will freeze.To stay in their comfort zone, animals have evolved very sensitive temperature sensors to detect the relatively narrow margin in which they can survive. Until recently, scientists knew little about how these sensors operated.Now, a team of Brandeis University scientists has discovered a previously unknown molecular temperature sensor in fruit flies belonging to a protein family responsible for sensing tastes and smells. These types of sensors are present in disease-spreading insects like mosquitoes and tsetse flies and may help scientists better understand how insects target warm-blooded prey — like humans — and spread disease.The discovery is published in today’s advance online edition of the journal Nature.Biting insects, such as mosquitoes, are attracted to carbon dioxide and heat. Notice how mosquitoes always seem to bite where there is the most blood? That is because those areas are the warmest, says Paul Garrity, a professor of biology in the National Center for Behavioral Genomics at Brandeis who co-authored the paper.”If you can find a mosquito’s temperature receptor, you can potentially produce a more effective repellent or trap,” Garrity says. “The discovery of this new temperature receptor in the fruit fly gives scientists an idea of where to look for similar receptors in the mosquito and in other insects.”Professor of Biology Leslie Griffith and Associate Professor of Biochemistry Douglas Theobald assisted with the research, which was led by postdoctoral fellows Lina Ni and Peter Bronk.The newly discovered sensor belongs to a family of proteins, called gustatory receptors, that have been studied for over a decade but never linked to thermosensation, Garrity says. In previous studies, other gustatory receptors have been found to allow insects to smell carbon dioxide and to taste sugar and bitter chemicals like caffeine.But in fruit flies, one type of gustatory receptor senses heat rather than smell or taste. …

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Physical inactivity, poor diet and smoking linked to disability in older population

July 24, 2013 — An unhealthy lifestyle is associated with a greater likelihood of developing disability over the age of 65, with the risk increasing progressively with the number of unhealthy behaviours, suggests a new article.Disability is commonly defined as “difficulty or dependency in carrying out activities essential to independent living.” With the number of disabled people expected to increase in coming years, researchers feel there is a need to define preventive strategies and slow this progression.Previous research has shown that unhealthy behaviours (such as physical inactivity, poor diet, smoking) have an adverse effect on health. For instance, the risk of obesity, diabetes, cancer, poor cognitive function, stroke, sudden cardiac death and mortality increases with the number of unhealthy behaviours.Researchers from France and the UK therefore carried out a study to investigate the relationship between unhealthy behaviours and the risk of disability over a 12 year period.They used data from the Three-City (3C) Dijon cohort study. Between 1999 and 2001, the study included community-dwelling older people (more than 65 years old) from the city of Dijon (France); participants were interviewed at that time about their lifestyle, including information on smoking, diet, physical activity, and alcohol drinking. They were then followed for the incidence of disability over 12 years.Three levels of disability were assessed: mobility, instrumental activities of daily living (IADL) and basic activities of daily living (ADL). Mobility assessed the ability to do heavy work around the house, walk half a mile, and climb stairs. IADLs included the ability to use a telephone, manage medications and money, use public or private transport, and do shopping, and, additionally for women, to prepare meals and do housework and laundry. ADLs included bathing, dressing, toileting, transferring from bed to chair and eating. Participants were considered disabled if they could not perform at least one activity without any given level of help.Low or intermediate physical activity, consumption of fruit and vegetables less than once a day, smoking (current or having quit smoking less than 15 years ago), and no (abstention or former) or heavy consumption of alcohol were all considered as unhealthy behaviours. Characteristics were also identified that may influence the relation between unhealthy behaviours and disability such as cardiovascular disease, diabetes, depression, high BMI and cancer.The final study included 3,982 participants of which 2,410 were women (60.5%).During the follow-up, 1,236 out of 3,982 (31%) participants developed disability. The incidence of disability increased with age, from 3.4/1000 person-years in those aged 65-70 years to 288/1000 person-years in those over 90 years of age. …

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Flip of mitotic spindle has disastrous consequences for epithelial cells

July 21, 2013 — Constructing a body is like building a house — if you compromise structural integrity, the edifice can collapse. Nowhere is that clearer on a cellular level than in the case of epithelial sheets, single layers of cells that line every body cavity from the gut to mammary glands. As long as epithelial cells pack tightly and adhere to their neighbors, the cellular business of building tissue barriers and constructing ducts goes smoothly. But if epithelial cells fail to hold together, they die, or worse, produce jumbled masses resembling tumors known collectively as carcinomas.Stowers Institute for Medical Research Associate Investigator Matt Gibson, Ph.D., and his team use simple animal systems like fruit flies and sea anemones to investigate how epithelial cells maintain order while getting jostled by cell division.New findings from his lab published in the July 21 advance online issue of Nature demonstrate that the way the mitotic spindle — the machinery that separates chromosomes into daughter cells during cell division — aligns relative to the surface of the cell layer is essential for the maintenance of epithelial integrity. It also hints at a surprising way that cells initiate a gene expression program seen in invasive cancers when that process goes awry.The study employs live imaging of fruit fly imaginal discs, simple larval tissues that ultimately give rise to the adult wing. “In a culture dish, cells can divide willy nilly,” says Gibson. “But in an organism cell division must be reconciled with the broader structural context. Our work is addressing how epithelial tissues maintain structural integrity, even during the extreme events of cell division.”The starting point for this work was the lab’s 2011 Current Biology paper showing that when columnar cells packed in an epithelium divided, their upper (apical) end briefly ballooned out to allow the cell’s nucleus to move into that region. As division began, the mitotic spindle (which faithfully distributes chromosomes into each daughter cell) invariably oriented itself parallel to the apical surface of the epithelium.In other words, if you pointed a tiny camera in your gut toward dividing epithelial cells of its lining, you would “see” the mitotic spindle looking like a symmetrical web, exactly like it did in your high school biology textbook.To determine why its orientation was non-random, the group did an equivalent experiment. Using high resolution fluorescence imaging to look inside dividing cells in developing wing discs, they observed that the two poles of the spindle were always near the septate junctions, specific regions of close molecular contact between neighboring cells. …

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Researchers identify ‘switch’ for long-term memory

July 8, 2013 — Neurobiologists at Heidelberg University have identified calcium in the cell nucleus to be a cellular “switch” responsible for the formation of long-term memory. Using the fruit fly Drosophila melanogaster as a model, the team led by Prof. Dr. Christoph Schuster and Prof. Dr. Hilmar Bading investigates how the brain learns. The researchers wanted to know which signals in the brain were responsible for building long-term memory and for forming the special proteins involved.Share This:The results of the research were published in the journal Science Signaling.The team from the Interdisciplinary Center for Neurosciences (IZN) measured nuclear calcium levels with a fluorescent protein in the association and learning centres of the insect’s brain to investigate any changes that might occur during the learning process. Their work on the fruit fly revealed brief surges in calcium levels in the cell nuclei of certain neurons during learning. It was this calcium signal that researchers identified as the trigger of a genetic programme that controls the production of “memory proteins.” If this nuclear calcium switch is blocked, the flies are unable to form long-term memory.Prof. Schuster explains that insects and mammals separated evolutionary paths approximately 600 million years ago. …

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Researchers Discover Species-Recognition System in Fruit Flies

June 27, 2013 — A team led by UC San Francisco researchers has discovered a sensory system in the foreleg of the fruit fly that tells male flies whether a potential mate is from a different species. The work addresses a central problem in evolution that is poorly understood: how animals of one species know not to mate with animals of other species.For the common fruit fly D. melanogaster, the answer lies in the chemoreceptor Gr32a, located on sensory neurons on the male fly’s foreleg. “In nature, this sensory system would prevent the creation of hybrids that may not survive or cannot propagate, thereby helping the species preserve its identity,” said senior author Nirao M. Shah, MD, PhD, a UCSF associate professor of anatomy.The work is reported in a paper published online in Cell on June 27, 2013.Before mating, the researchers found, the male approaches a prospective female and taps her repeatedly on the side with his foreleg. “As he does so, he is using Gr32a to detect, or actually taste, unpleasant-tasting waxy chemicals on the cuticle, or outer skin, of individuals of other species, said co-author Devanand S. Manoli, MD, PhD, a UCSF postdoctoral fellow in anatomy and fellow in child and adolescent psychiatry. “If the prospective mate is not of the same species, and Gr32a is activated, the mating ritual stops right there, even if the male has never encountered a female of another species before.”The researchers also found that if the male fly’s Gr32a neurons are activated directly, courtship with other species can be suppressed in these male flies. “These and other findings show that Gr32a neurons are both necessary, in terms of having this taste receptor, and sufficient, in terms of their activity, to prevent males from courting females of other species,” said Manoli.Remarkably, said Shah, Gr32a mediates the rejection of a large range of fruit fly species that last shared a common ancestor with D. melanogaster two to 40 million years ago.”Indeed, D. …

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Sequentially expressed genes in neural progenitors create neural diversity

June 19, 2013 — A team of New York University biologists has found that a series of genes sequentially expressed in brain stem cells control the generation of neural diversity in visual system of fruit flies. Their results are reported in the latest issue of the journal Nature.In order for the brain to properly develop and function, a vast array of different types of neurons and glia must be generated from a small number of progenitor cells. By better understanding the details of this process, scientists can develop ways to recognize and remedy a range of neural afflictions such as microcephaly or neurodegeneration.The research, conducted in the laboratory of NYU Biology Professor Claude Desplan, examined this process by studying the neurons in the visual centers of the fruit fly Drosophila. Drosophila is a powerful model for studying neural diversity because of its relative simplicity, although the studied brain structure, termed the medulla, contains approximately 40,000 neurons, belonging to more than 70 cell types.Specifically, they examined the genes expressed in neuroblasts — dividing neural stem cells that generate neurons — in the medulla and how and when they are expressed. Their findings revealed that five genes encoding five different transcription factors — proteins that bind to specific DNA sequences — are expressed in a specified order in each of the medulla neuroblasts as they age. The five genes form a temporal cascade: one gene can activate the next gene and repress the previous gene, thus ensuring the progression of the temporal sequence.It is this process, the researchers found, that controls the sequential generation of different neural types in the Drosophila medulla. These results, together with other studies in the field, suggest that a similar mechanism is utilized to generate neural diversity in the brains of humans and other mammals.

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How neural stem cells create new and varied neurons

June 19, 2013 — A new study examining the brains of fruit flies reveals a novel stem cell mechanism that may help explain how neurons form in humans. A paper on the study by researchers at the University of Oregon appeared in the online version of the journal Nature in advance of the June 27 publication date.”The question we confronted was ‘How does a single kind of stem cell, like a neural stem cell, make all different kinds of neurons?'” said Chris Doe, a biology professor and co-author on the paper “Combinatorial temporal patterning in progenitors expands neural diversity.”Researchers have known for some time that stem cells are capable of producing new cells, but the new study shows how a select group of stem cells can create progenitors that then generate numerous subtypes of cells.”Instead of just making 100 copies of the same neuron to expand the pool, these progenitors make a whole bunch of different neurons in a particular way, a sequence,” Doe said. “Not only are you bulking up the numbers but you’re creating more neural diversity.”The study, funded by the Howard Hughes Medical Institute and the NIH National Institute of Child Health and Human Development, builds on previous research from the Doe Lab published in 2008. That study identified a special set of stem cells that generated neural progenitors. These so-called intermediate neural progenitors (INPs) were shown to blow up into dozens of new cells. The research accounted for the number of cells generated, but did not explain the diversity of new cells.”While it’s been known that individual neural stem cells or progenitors could change over time to make different types of neurons and other types of cells in the nervous system, the full extent of this temporal patterning had not been described for large neural stem cell lineages, which contain several different kinds of neural progenitors,” said lead author Omar Bayraktar, a doctoral student in developmental neurobiology who recently defended his dissertation.The cell types in the study, Bayraktar said, have comparable analogs in the developing human brain and the research has potential applications for human biologists seeking to understand how neurons form.The Nature paper appears alongside another study on neural diversity by researchers from New York University. Together the two papers provide new insight into the processes involved in producing the wide range of nerve cells found in the brains of flies.For their study, Bayraktar and Doe zeroed in on the stem cells in drosophila (fruit flies) known as type II neuroblasts. The neuroblasts, which had previously been shown to generate INPs, were shown in this study to be responsible for a more complex patterning of cells. The INPs were shown to sequentially generate distinct neural subtypes. The research accounted for additional neural diversity by revealing a second axis in the mechanism. …

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