medicalnewstoday.com
News Tips From The Journal Of Neuroscience
03.07.2008 04:14
medicalnewstoday.com
1. Regenerative Axon Growth in Normal Mice Oswald Steward, Binhai Zheng, Marc Tessier-Lavigne, Maura Hofstadter, Kelli Sharp, and Kelly Matsudaira Yee The corticospinal tract of mice exhibits some regenerative growth without any therapeutic manipulation, according to Steward et al. After complete transection of the dorsal column, a few axons appeared to grow past the lesion via the ventral column.
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Biology
Inbreeding And Amphibian Malformations
03.07.2008 04:13
medicalnewstoday.com
We captured 687 adult and 1259 larval tiger salamanders (Ambystoma tigrinum), assessed individuals for gross malformations, and surveyed genetic variation among malformed and normal individuals using both cytoplasmic and nuclear markers. The overall frequency of adults with malformations was 0.078 compared to 0.081 in larval samples.
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Biology
Selection On Personality In A Songbird Affects Maternal Hormone Levels Tuned To Its Effect On Timing Of Reproduction
03.07.2008 04:13
medicalnewstoday.com
In birds, as in humans, mothers modulate offspring development by maternal hormones. We found in a wild bird species differences in testosterone within and between clutches of mothers selected for distinct personalities. Selection also affected timing of reproduction, allowing hormone mediated adjustments to seasonal variation in food availability.
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Biology
Stiffness Gradients In Vascular Bundles Of Palm Trees
03.07.2008 04:13
medicalnewstoday.com
In palm trees, stiff fibres are embedded in soft surrounding tissue. The design of the interface of these tissues is crucial for the functioning of the stem. Mechanical, structural and biochemical investigations with high spatial resolution showed that independent sources acting together at different levels of hierarchy create a stiffness gradient. Hereby, we found an additional mechanism of how plants can control axial stiffness.
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Biology
The Modeling Of Avian Visual Perception Predicts Behavioural Rejection Responses To Foreign Egg Colours
03.07.2008 04:13
medicalnewstoday.com
How do birds tell the colours of their own and foreign eggs apart? We evaluate a model of avian physiological visual acuity to determine its accuracy as a predictor of song thrush Turdus philomelos discriminating artificial eggs and rejecting them from her clutch. We show that the large degree of variation of egg coloration between clutches (compared with variation within a clutch) should provide sufficient contrasts for rejecting experimental conspecific parasitism.
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Biology
Egg Colour Mimicry In The Common Cuckoo Cuculus Canorus As Revealed By Modelling Host Retinal Function
03.07.2008 04:13
medicalnewstoday.com
Do cuckoos effectively mimic their hosts? Here it is assessed from a host perspective whether the colour design of cuckoo eggs of different races maximizes matching for two favourite avian hosts. Secondly, it is assessed the role of nest luminosity on host perception of matching.
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Biology
Functional Group Diversity Of Bee Pollinators Increases Crop Yield
03.07.2008 04:13
medicalnewstoday.com
In a study on the functional role of biodiversity in tropical agroforestry systems, we found that pollinator diversity, but not abundance, was positively related to seed set of pumpkin. Furthermore, we classified species due to differences in spatiotemporal resource use and within-flower behaviour into functional guilds and showed that diversity of functional groups explained more variance in seed set than did species richness, highlighting the role of functional complementarity.
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Biology
Fish Odour Triggers Conspecific Attraction Behavior In An Aquatic Invertebrate
03.07.2008 04:13
medicalnewstoday.com
Group living has evolved as an adaptation to predation in many animal species. In a multitude of vertebrates, the tendency to aggregate varies with the risk of predation, but experimental evidence for this is less well known in invertebrates. Here, we examine the tendency to aggregate in the freshwater amphipod Gammarus pulex in the absence and presence of predator fish odour. Without fish odours, the gammarids showed no significant tendency to aggregate.
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Biology
Female Bushcrickets Fuel Their Metabolism With Male Nuptial Gifts
03.07.2008 04:12
medicalnewstoday.com
In some animals, such as bushcrickets, males donate a nutritious gift to a potential mate, and females ingest this so-called nuptial gift during copulation. Previously it was thought that most nuptial gift nutrients are routed to egg production. But, recent studies with isotopically labeled nuptial gifts reveal that female bushcrickets combust nuptial gift nutrients immediately after mating.
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Biology
Predicting The Fate Of A Living Fossil: How Will Global Warming Affect Sex Determination And Hatching Phenology In Tuatara?
03.07.2008 04:12
medicalnewstoday.com
Climate warming will affect animals in many ways, including the sex of some species' offspring. For tuatara, unique and ancient reptiles from New Zealand, warmer nest temperatures produce male-biased clutches. We predicted sex ratios and hatching times of tuatara clutches under future climate scenarios by linking egg development data with sophisticated models of soil microclimates.
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Biology
New Book For Parents Of Children With Juvenile Arthritis
03.07.2008 04:12
medicalnewstoday.com
The Arthritis Foundation announces the publication of a new book for parents of children with juvenile arthritis (JA). Released in conjunction with Juvenile Arthritis Awareness Month in July, the all-new Raising a Child with Arthritis addresses many of the concerns parents have about JA - from diagnosis and treatments to family and financial issues.
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Arthritis
Pediatric Researchers Find Possible 'Master Switch' Gene In Juvenile Arthritis
03.07.2008 04:12
medicalnewstoday.com
Researchers have found that a gene region known to play a role in some varieties of adult rheumatoid arthritis is also present in all types of childhood arthritis. The researchers say the responsible gene may be a "master switch" that helps turn on the debilitating disease. Researchers at The Children's Hospital of Philadelphia reported on the link between the gene region and juvenile idiopathic arthritis (JIA), formerly called juvenile rheumatoid arthritis.
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Arthritis
Yoga And Meditation Change Gene Response To Stress
03.07.2008 04:12
medicalnewstoday.com
Research from the US suggests that mind body techniques like yoga and meditation that put the body in a state of deep rest known as the relaxation response, are capable of changing how genes behave in response to stress.
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Depression
News From The Journal Of Clinical Investigation July 1, 2008
03.07.2008 04:11
medicalnewstoday.com
Calpain inhibitors never forget: improving memory in Alzheimer disease mice Overactivation of proteins known as calpains, which are involved in memory formation, has been linked to Alzheimer disease.
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Alzheimer's Disease
Study Examines Mental Health Coverage In State Health Care Initiatives
03.07.2008 04:11
medicalnewstoday.com
"Coverage for All: Inclusion of Mental Illness and Substance Use Disorders in State Healthcare Reform Initiatives," National Alliance on Mental Illness/National Council for Community Behavioral Healthcare: The study finds that more than one in four uninsured U.S.
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Harmful Habits
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