118 research outputs found
Medical eponyms
Eponyms are a long-standing tradition in medicine. Eponyms usually involve honoring a prominent physician scientist who played a major role in the identification of the disease. Under the right circumstances, a disease becomes well known through the name of this individual. There are no rules on eponym development. It may take an extraordinary period of time, be different in different languages and cultures, and evolve as more is known about the physician or the disease
Effect of sampling effort and sampling frequency on the composition of the planktonic crustacean assemblage: a case study of the river Danube
Although numerous studies have focused
on the seasonal dynamics of riverine zooplankton,
little is known about its short-term
variation. In order to examine the effects of sampling
frequency and sampling effort, microcrustacean
samples were collected at daily intervals
between 13 June and 21 July of 2007 in a parapotamal
side arm of the river Danube, Hungary.
Samples were also taken at biweekly intervals
from November 2006 to May 2008. After presenting
the community dynamics, the effect of
sampling effort was evaluated with two different
methods; the minimal sample size was also estimated.
We introduced a single index (potential
dynamic information loss; to determine the potential
loss of information when sampling frequency
is reduced. The formula was calculated for the total abundance, densities of the dominant taxa, adult/larva ratios of copepods and for two different diversity measures. Results suggest that abundances may experience notable fluctuations even within 1 week, as do diversities and adult/larva ratios
Climate change and freshwater zooplankton: what does it boil down to?
Recently, major advances in the climate–zooplankton interface have been made some of which appeared to receive much attention in a broader audience of ecologists as well. In contrast to the marine realm, however, we still lack a more holistic summary of recent knowledge in freshwater. We
discuss climate change-related variation in physical and biological attributes of lakes and running waters, high-order ecological functions, and subsequent alteration
in zooplankton abundance, phenology, distribution, body size, community structure, life history parameters, and behavior by focusing on community level responses. The adequacy of large-scale climatic indices in ecology has received considerable support and provided a framework for the interpretation of community and species level responses in freshwater zooplankton. Modeling perspectives deserve particular consideration, since this promising stream of
ecology is of particular applicability in climate change
research owing to the inherently predictive nature of
this field. In the future, ecologists should expand their
research on species beyond daphnids, should address
questions as to how different intrinsic and extrinsic
drivers interact, should move beyond correlative
approaches toward more mechanistic explanations,
and last but not least, should facilitate transfer of
biological data both across space and time
Dopaminergic Activation of Estrogen Receptors Induces Fos Expression within Restricted Regions of the Neonatal Female Rat Brain
Steroid receptor activation in the developing brain influences a variety of cellular processes that endure into adulthood, altering both behavior and physiology. Recent data suggests that dopamine can regulate expression of progestin receptors within restricted regions of the developing rat brain by activating estrogen receptors in a ligand-independent manner. It is unclear whether changes in neuronal activity induced by dopaminergic activation of estrogen receptors are also region specific. To investigate this question, we examined where the dopamine D1-like receptor agonist, SKF 38393, altered Fos expression via estrogen receptor activation. We report that dopamine D1-like receptor agonist treatment increased Fos protein expression within many regions of the developing female rat brain. More importantly, prior treatment with an estrogen receptor antagonist partially reduced D1-like receptor agonist-induced Fos expression only within the bed nucleus of the stria terminalis and the central amygdala. These data suggest that dopaminergic activation of estrogen receptors alters neuronal activity within restricted regions of the developing rat brain. This implies that ligand-independent activation of estrogen receptors by dopamine might organize a unique set of behaviors during brain development in contrast to the more wide spread ligand activation of estrogen receptors by estrogen
PDZ domains and their binding partners: structure, specificity, and modification
PDZ domains are abundant protein interaction modules that often recognize short amino acid motifs at the C-termini of target proteins. They regulate multiple biological processes such as transport, ion channel signaling, and other signal transduction systems. This review discusses the structural characterization of PDZ domains and the use of recently emerging technologies such as proteomic arrays and peptide libraries to study the binding properties of PDZ-mediated interactions. Regulatory mechanisms responsible for PDZ-mediated interactions, such as phosphorylation in the PDZ ligands or PDZ domains, are also discussed. A better understanding of PDZ protein-protein interaction networks and regulatory mechanisms will improve our knowledge of many cellular and biological processes
Year-to-year variation in larval fish assemblages of the Southern North Sea
In order to test the temporal stability within and the reproducibility of larval fish assemblages between years, the larval fish assemblage at Helgoland Roads, North Sea (NE Atlantic) was quantitatively sampled almost daily from January 2003 to December 2005. The survey resulted in a total of 462 samples containing 50,632 larval fish of at least 42 taxa. In winter the larval fish assemblage was mainly dominated by larvae emerging from demersal eggs. This changed gradually to larvae hatching from pelagic eggs. Larvae from pelagic eggs dominated the ichthyoplankton assemblage in summer. A remarkably stable seasonality in terms of dominance patterns with recurring, season-specific fish assemblages was observed over the three years, despite substantial variation in environmental conditions such as a temperature difference of almost 20°C between summer and winter. The lesser sandeel (Ammodytes marinus), was the only species which showed significant fluctuations in abundance between the years. After removal of this species from the analysis, the dominance patterns of the remaining fish species were almost identical between years
Does adjuvant external-beam radiotherapy improve outcomes for nonbenign meningiomas? A Surveillance, Epidemiology, and End Results (SEER)–based analysis
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