Search Results
Abstract
The size and ageing of the Chilean scientific community was studied using as data the individuals actively engaged in research projects funded by the National Fund for Scientific and Technological Development (FONDECYT). Between 1982 and 1991, 4966 individuals participated at least once, either as responsible for the research or as qualified associate in one term of the funding period. From this population, 2765 persons can be considered further committed with scientific research. As for sex, about 30% of the researchers are women. Taking into account all the disciplines, and in addition to the fact that the size of the Chilean scientific community seems to be subcritical, the study reveals that the workforce has been ageing dangerously through the years. The number of young scientists becoming part of the scientific workforce is decreasing. Research in mathematics, physics and chemistry, although qualitatively competitive, relies only on an extremely small group of excellent scientists, situation which is seriously affecting the scientific capacity that the country needs. Biology, although with a higher number of individuals, exhibits a pattern of ageing which will also affects the possibilities to strengthen the scientific demands. The global context in which science develops, leads to a brain drain that Third World countries will have to overcome, implementing public policies to offer the support that young people require to nurture the scientific strength. Indigenous Ph. D. programs demand urgent attention of policy decision makers as well as from research universities which need to offer opportunities to substitute, when existing, their incompetent faculty.
Abstract
On the basis of the measured time-dependent distribution of references in recent scientific publications, we formulate a novel model on the ageing of recent scientific literature. The framework of this model is given by a basic set of mathematical expressions that allows us to understand and describe large-scale growth and ageing processes in science over a long period of time. In addition, a further and striking consequence results in a self- consistent way from our model. After the Scientific Revolution in 16th century Europe, the 'Scientific Evolution' begins, and the driving processes growth and ageing unavoidably lead - just as in our biological evolution - to a fractal differentiation of science. A fractal structure means a system build up with sub-systems characterised by a power-law size distribution. Such a distribution implies that there is no preference of size or scale. Often this phenomenon is regarded as a fingerprint of self-organisation. These findings are in agreement with earlier empirical findings concerning the clustering of scientific literature. Our observations reinforce the idea of science as a complex, largely self-organising 'cognitive eco-system'. They also refute Kuhn's paradigm model of scientific development.
Zarbin, M. A.: Current concepts in the pathogenesis of age-related macular degeneration. Arch Ophthalmol., 2004, 122 , 598–614. Zarbin M. A
, P., Mirand, P. P., Boirie, Y., Morio, B., Mosoni, L. (2005) Due to reverse electron transfer, mitochondrial H 2 O 2 release increases with age in human vastus lateralis muscle although oxidative capacity is preserved. Mech. Ageing Dev. 126
Introduction
The aim of this study was to explore spontaneous social interactions between dyads of unfamiliar adult dogs. Although intraspecific encounters are frequent events in the life of pet dogs, the factors that might influence encounters, such as sex, dyad composition, reproductive status, age, and state of cohabitation (keeping the dogs singly or in groups), remained unexplored.
Methods
In this study, we assigned unfamiliar, non-aggressive dogs to three types of dyads defined by sex and size. We observed their unrestrained, spontaneous behaviors in an unfamiliar dog park, where only the two dogs, the owners, and experimenter were present.
Results
We found that the dogs, on average, spent only 17% of the time (less than 1 min) in proximity. Sex, dyad composition, reproductive status, and age influenced different aspects of the interactions in dyads. Female dogs were more likely to initiate the first contact in their dyad but later approached the partner less frequently, were less likely to move apart, and displayed less scent marking. Following and moving apart were more frequent in male–male interactions. Neutered dogs spent more time following the other dog and sniffed other dogs more frequently. The time companion dogs spent in proximity and number of approaches decreased with age.
Conclusion
The study provides guidance for dog owners about the outcomes of intraspecific encounters based on the dog’s age, sex, and reproductive status, as well as the sex of the interacting partner.
aims to explore critical aspects of ADHD across all age groups, including symptomatology, functional impairment, and comorbid psychiatric disorders. The disorder is lifelong, with symptoms evolving throughout an individual's life. The extent of adult
Adloff, M., Arnaud, J. P., Schloegel, M., et al.: Colorectal cancer in patients under 40 years of age. Dis. Colon Rectum, 1986, 29 , 322–325. Schloegel M. Colorectal cancer in
Abstract
Thermally Stimulated Current (TSC) technique is a relaxation technique, such as DMA, but works at very low equivalent frequency (10−3–10−4Hz) and thus clearly resolves the peaks related to the molecular mobility. The effect of orientation on Polypropylene fibers, the relaxation of internal stresses on Polycarbonate disks, and the effect of aging on acrylic airplane windows have been investigated using the TSC method.
. , Chan , R. M. , Loughead , J. W. , Alsop , D. C. , Maldjian , J. , Gur , R. E. ( 2003 ): Age-related differences in brain activation during emotional face processing . Neurobiology of Aging, 24 , 285 – 295
ikerterhességek anyai és magzati kórjóslata 122 eset alapján. Orv. Hetil., 2007, 148 (submitted). Gilbert, W. M., Nesbitt, T. S., Danielsen, B.: Childbearing beyond age 40: Pregnancy outcome in 24032 cases
