Search results for "Evolution"
showing 10 items of 11096 documents
Temperature sensation: the "3-bowls experiment" revisited.
1990
The "3-bowls experiment", usually attributed to E. H. Weber*, will be remembered by many from their first lab course in human physiology. The left and right hands are immersed for several minutes in bowls containing water at 10 and 40°C, respectively. When both hands are then placed in a third bowl of water at 27 °C, the left hand feels distinctly warm and the right hand distinctly cool. Until now nobody has been able to reconcile this apparent unreliability of the sense of temperature with the observation that humans regularly make judgements of the temperatures of objects; for example, mothers seldom use a thermometer to check the temperature of a baby's milk, but rather hold the bottle a…
GENOMIC EPIDEMIOLOGY OF TUBERCULOSIS: FROM WITHIN HOST EVOLUTION TO GLOBAL MIGRATION PATTERNS
2018
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Physiological problems of teleost ambisexuality
1988
The normal occurrence of spontaneous sex inversion among teleosts is a recent item within current concepts on vertebrate reproductive physiology. Investigations on the subject are mostly descriptive and deal with morphological and behavioral aspects. The concept of social control of sex inversion has been received with great interest. However, research on physiological processes that take place inside a fish when it changes sex must be rated as fragmentary. Steroid hormones are supposed to play a major role in sex inversion. But a cause and effect relationship has not yet been established. More experimental studies on more types of ambisexual species are badly needed. Future work will show …
EQ-5D-3L for Assessing Quality of Life in Older Nursing Home Residents with Cognitive Impairment
2020
Background: Quality of life (QoL) is recognized as an important patient-reported outcome measure. Assessing QoL in older people with cognitive impairment is a challenge due to discrepancies in the collection of data via proxies versus self-report. This study aimed to assess the psychometric properties of the self-reported EQ-5D (including the EQ index and EQ visual analog scale (VAS)) in nursing homes residents with cognitive impairment and to analyze its validity based on scales included in the comprehensive geriatric assessment. Methods: Cross-sectional, multicenter study analyzing the feasibility, acceptability, reliability, and validity of the EQ-5D based on 251 self-administered questi…
Aerobiology: an ecological indicator for early detection and control of fungal outbreaks in caves
2011
5 pages, 1 table, 13 references.
Factores Asociados al Consumo Juvenil de Alcohol: Una Revisión desde una Perspectiva Psicosocial y Ecológica
2011
ResumenEl consumo abusivo de alcohol en la adolescencia es, en el momento actual, un importante problema de salud pública, hasta el punto de que su prevención se ha convertido en una de las prioridades en las políticas de salud. También, y en el ámbito de la intervención social, se ha venido estudiando, en los últimos años, los factores psicosociales implicados en ese consumo. En el presente trabajo se lleva a cabo una revisión de esos factores en el marco de la perspectiva ecológica, en la que se integran las variables psicológicas, relacionales y socioculturales. El consumo de alcohol es analizado como parte integrante de la cultura juvenil, despojando la explicación de contenidos patolog…
The toxic and lethal effects of the trehalase inhibitor trehazolin in locusts are caused by hypoglycaemia
2003
SUMMARY The main blood sugar of locusts is trehalose, which is hydrolysed to two glucose units by trehalase. Homogenates of locust flight muscles are rich in trehalase activity, which is bound to membranes. A minor fraction of trehalase is in an overt form while the remainder is latent, i.e. active only after impairing membrane integrity. Trehazolin, an antibiotic pseudosaccharide,inhibits locust flight muscle trehalase with apparent Ki-and EC50 values of 10–8 mol l–1and 10–7 mol l–1, respectively. Trehazolin is insecticidal: 50 μg injected into locusts completely and selectively blocked the overt form of muscle trehalase (with little effect on latent activity) and killed 50% of the insects…
Preliminary identification and quantification of steroid hormones in the red palm weevil, Rhynchophorus ferrugineus
2012
In the present preliminary study, we used a gas chromatography–mass spectroscopy (GC-MS) method to identify and quantify steroid hormones, their precursors and metabolites in whole body of red palm weevil (RPW) R. ferrugineus adults. We identified a total of seven steroids by single ion monitoring mode (SIM) analysis and compared them to the National Institute of Standards and Technology (NIST) library. The steroids include: dehydroepiandrosterone (DHEA), estrone, estradiol-17β, testosterone, progesterone, cortisol and cholesterol, whereas pregnenolone, pregnan-20-one-17-hydroxy and corticosterone were not detected. This study shows that some invertebrate groups seem to use partially or tot…
Prenatal testosterone of progenitors could be involved in the etiology of both anorexia nervosa and autism spectrum disorders of their offspring
2014
Objectives High intrauterine testosterone (T) levels seem to play a role in the development of autism spectrum disorders (ASDs), but their role in anorexia nervosa (AN) is controversial. Parents with masculinized 2D:4D ratios, a marker of the organizational effects of T, may have other relevant biological characteristics, in particular exposing their offspring to high T levels in the prenatal environment. This would increase the likelihood of their offspring developing these disorders. Methods The present study examined whether parents of offspring with AN (n=34; mean age= 51) and ASD (n=36; mean age=45) differ from control parents (n=40; mean age=43) in 2D:4D ratio, as well as by salivary …
Temporal and Spatial Evolution of Cortical Blood Flow in the Penumbra of Venous Infarcts
2001
A cortical venous infarction model has been evaluated regarding the temporal and spatial evolution of regional flow reduction. Two cortical veins were occluded photochemically with rose bengal and fiberoptic illumination. Seven rats served to demonstrate effects on regional cortical blood flow using laser Doppler scanning. After two-vein occlusion, there was a widespread reduction of flow that gradually deteriorated after vein occlusion when regional cortical flow in a 3.5 x 7.0 mm window: after 15 min it had decreased to 57.8% ± 8.0%, and after 75 min it was 34.3% ± 5.4%. Infarct volumes as determined in 10 rats 5 days after two-vein occlusion had an average size of 3.6 ± 0.7 mm3. The data…