Posts Tagged ‘Plants & Animals’
ScienceDaily (Dec. 19, 2009) — Carotenoids, found in green leafy vegetables and colored fruits, have been found to increase visual performance and may prevent age-related eye diseases, according to a study in the Journal of Food Science, published by the Institute of Food Technologists.
Authors from the University of Georgia compiled the results of multiple studies on the effects of the carotenoids lutein and zeaxanthin on visual performance. These carotenoids play an important role in human vision, including a positive impact on the retina.
After reviewing the various studies, the authors concluded that macular pigments, such as lutein and zeaxanthin do have an effect on visual performance. Lutein and zeaxanthin can reduce disability and discomfort from glare, enhance contrast, and reduce photostress recovery times. They can also reduce glare from light absorption and increase the visual range.
Lead author Dr. Billy R. Hammond Jr. noted that the research of the effects of lutein and zeazanthin are important because “it is clear that they could potentially improve vision through biological means. For example, a study conducted in 2008 suggests that the pigments protect the retina and lens and perhaps even help prevent age-related eye diseases such as macular degeneration and cataract.”
What is self evident has taken years to find out.
ScienceDaily (Dec. 19, 2009) — Why does a human baby need a full year before it can start walking, while a newborn foal gets up on its legs almost directly after birth? Scientist have assumed that human motor development is unique because our brain is unusually complex and because it is particularly challenging to walk on two legs. But now a research group at Lund University in Sweden has shown that human babies in fact start walking at the same stage in brain development as most other walking mammals, from small rodents to elephants.
The findings are published in the journal PNAS.
The Lund group consists of neurophysiologists Martin Garwicz and Maria Christensson and developmental psychologist Elia Psouni. Contrary to convention, they used conception and not birth as the starting point of motor development in their comparison between different mammals. This revealed astonishing similarities among species that diverged in evolution as much as 100 million years ago. — Humans certainly have more brain cells and bigger brains than most other terrestrial mammalian species, but with respect to walking, brain development appears to be similar for us and other mammals. Our study demonstrates that the difference is quantitative, not qualitative, says Martin Garwicz.
Based on knowledge about development in other mammals it is therefore possible to actually predict with high precision when human babies will start to walk. This is a very unexpected and provocative finding.
The notion that humans have a unique position among mammals is not only deeply rooted among lay people, but is also reflected in fundamental assumptions in different research fields related to human development and human brain evolution.
“Our study strongly contradicts this assumption and thereby sheds new light on theories in, for instance, evolutionary and developmental biology,” says Martin Garwicz. “On the other hand, our findings fit well with the substantial similarities between the genomes of different mammals. Perhaps these similarities are after all not that surprising — although the end products ‘human’ and ‘rat’ may be very different, our study suggests that the building blocks and principles for how these building blocks interact with one another during development could be the same.”
The study originated in an attempt by the group to translate behavioral milestones of motor development between two distantly related species. The similarities in relative developmental time courses between the two species were so striking that the scientists started to wonder whether the regularity applied to other mammals and ultimately also to humans.
The Lund group has now compared 24 species, which together represent the majority of existing walking mammals. Some, like the great apes, are closely related to us evolutionarily while others, such as rodents, hoofed animals, and elephants, diverged from our evolutionary path about 90-100 million years ago.
Despite this, and regardless of differences in various species’ brain and body size, gestation time, and brain maturity at birth, the comparison shows that the young from all species start walking at the same relative time point in brain development. Humans may be unique, but not in this particular way. When the nervous system has reached a given level of maturity, you learn to walk, whether you are a hedgehog, a foal, or a human baby…
Breakfast-not later than 7 am,Lunch-not later than 1 pm,Dinner-not later than 10 pm.
Breakfast must be heavy;avoid drinking water during meals.Fill the stomach half part,1/4 water,leave 1/4 empty.Avoid oil in breakfast.
Lunch must have leafy vegetables,nothing should be deep fried,oil to be used minimally,use spice rarely,drink butter milk,minimal use of meat and root vegetables.
Dinner-avoid milk products and curds and desserts like ice cream.
Do not engage in conversation while eating.( Source;Indian food habits as per Smriti)
Take fruits in empty stomach.
ScienceDaily (Nov. 26, 2009) — When you eat may be just as vital to your health as what you eat, found researchers at the Salk Institute for Biological Studies. Their experiments in mice revealed that the daily waxing and waning of thousands of genes in the liver — the body’s metabolic clearinghouse — is mostly controlled by food intake and not by the body’s circadian clock as conventional wisdom had it.
“If feeding time determines the activity of a large number of genes completely independent of the circadian clock, when you eat and fast each day will have a huge impact on your metabolism,” says the study’s leader Satchidananda (Satchin) Panda, Ph.D., an assistant professor in the Regulatory Biology Laboratory.
The Salk researchers’ findings, which will be published in a forthcoming issue of the Proceedings of the National Academy of Sciences, could explain why shift workers are unusually prone to metabolic syndrome, diabetes, high cholesterol levels and obesity.
“We believe that it is not shift work per se that wreaks havoc with the body’s metabolism but changing shifts and weekends, when workers switch back to a regular day-night cycle,” says Panda.
In mammals, the circadian timing system is composed of a central circadian clock in the brain and subsidiary oscillators in most peripheral tissues. The master clock in the brain is set by light and determines the overall diurnal or nocturnal preference of an animal, including sleep-wake cycles and feeding behavior. The clocks in peripheral organs are largely insensitive to changes in the light regime. Instead, their phase and amplitude are affected by many factors including feeding time.
The clocks themselves keep time through the fall and rise of gene activity on a roughly 24-hour schedule that anticipates environmental changes and adapts many of the body’s physiological function to the appropriate time of day.
“The liver oscillator in particular helps the organism to adapt to a daily pattern of food availability by temporally tuning the activity of thousands of genes regulating metabolism and physiology,” says Panda. “This regulation is very important, since the absence of a robust circadian clock predisposes the organism to various metabolic dysfunctions and diseases.”
Despite its importance, it wasn’t clear whether the circadian rhythms in hepatic transcription were solely controlled by the liver clock in anticipation of food or responded to actual food intake.
To investigate how much influence rhythmic food intake exerts over the hepatic circadian oscillator, graduate student and first author Christopher Vollmers put normal and clock-deficient mice on strictly controlled feeding and fasting schedules while monitoring gene expression across the whole genome.
He found that putting mice on a strict 8-hour feeding/16-hour fasting schedule restored the circadian transcription pattern of most metabolic genes in the liver of mice without a circadian clock. Conversely, during prolonged fasting, only a small subset of genes continued to be transcribed in a circadian pattern even with a functional circadian clock present.
“Food-induced transcription functions like a metabolic sand timer that runs for 24 hours and is continually reset by the feeding schedule while the central circadian clock is driven by self-sustaining rhythms that help us anticipate food, based on our usual eating schedule,” says Vollmers. “But in the real world we don’t eat at the same time every day and it makes perfect sense to increase the activity of metabolic genes when you need them the most.”
For example, genes that encode enzymes needed to break down sugars rise immediately after a meal, while the activity of genes encoding enzymes needed to break down fat is highest when we fast. Consequently a clearly defined daily feeding schedule puts the enzymes of metabolism in shift work and optimizes burning of sugar and fat.
“Our study represents a seminal shift in how we think about circadian cycles,” says Panda. “The circadian clock is no longer the sole driver of rhythms in gene function, instead the phase and amplitude of rhythmic gene function in the liver is determined by feeding and fasting periods — the more defined they are, the more robust the oscillations become.”
While the importance of robust metabolic rhythms for our health has been demonstrated by shift workers’ increased risk of developing metabolic syndrome, the underlying molecular reasons are still unclear. Panda speculates that the oscillations serve one big purpose: to separate incompatible processes, such as the generation of DNA-damaging reactive oxygen species and DNA replication.
Panda, for one, has stopped eating between 8 pm and 8 am and says he feels great. “I even lost weight, although I eat whatever I want during the day,” he says.
Researchers who also contributed the work include postdoctoral researcher Luciano DiTacchio, Ph.D., graduate students Sandhyarani Pulivarthy and Shubhrox Gill, as well as research assistant Hiep Le, all in the Regulatory Biology Laboratory.
The work was funded in part by the National Institutes of Health and the Pew Scholars
Adapted from materials provided by Salk Institute.