Ariès

About: Ariès is a based out in . It is known for research contribution in the topics: Error detection and correction & Stars. The organization has 372 authors who have published 461 publications receiving 7548 citations. The organization is also known as: Aries.

Cerebral Autoregulation in Stroke A Review of Transcranial Doppler Studies

Abstract: Background and Purpose—Cerebral autoregulation may become impaired after stroke. To provide a review of the nature and extent of any autoregulation impairment after stroke and its course over time, a technique allowing repeated bedside measurements with good temporal resolution is required. Transcranial Doppler (TCD) in combination with continuous blood pressure measurements allows noninvasive continuous bedside investigation with high temporal resolution of the dynamic and the steady-state components of cerebral autoregulation. Therefore, this review focuses on all TCD studies on cerebral autoregulation in the setting of documented ischemic stroke. Methods—PubMed and EMBASE were searched for studies of stroke, autoregulation, and TCD. Studies were either acute phase ( 96 hours after index stroke) autoregulation studies. Quality of studies was studied in a standardized fashion. Results—Twenty-three studies met the inclusion criteria. General agreement existe...

An Observed Trend in Central South American Precipitation

Abstract: Seasonal linear trends of precipitation from South American station data, which have been averaged onto grids, are examined, with emphasis on the central continent. In the period 1976–99, the largest trend south of 20°S occurs during the January–March season, is positive, and is centered over southern Brazil. From 1948 to 1975 the trend is also positive, but with less than half the slope. The trend is not due to a systematic change in the timing of the rainy season, which almost always starts before January and usually ends after March, but rather results from an increase in the percent of rainy days, and an increase in the rainy day average. The dynamic causes of the trend are not obvious. It does not appear to be accounted for by an increase in synoptic wave activity in the region. The precipitation trend is related to a positive sea surface temperature trend in the nearby Atlantic Ocean, but apparently not causally. The trend in the Atlantic seems to result from a decrease in mechanical stirri...

Dynamic changes in Rad51 distribution on chromatin during meiosis in male and female vertebrates

Abstract: Antibodies against human Rad51 protein were used to examine the distribution of Rad51 on meiotic chromatin in mouse spermatocytes and oocytes as well as chicken oocytes during sequential stages of meiosis. We observed the following dynamic changes in distribution of Rad51 during meiosis: (1) in early leptotene nuclei there are multiple apparently randomly distributed, foci that by late leptonema become organized into tracks of foci. (2) These foci persist into zygonema, but most foci are now localized on Rad51-positive axes that correspond to lateral elements of the synaptonemal complex. As homologs synapse foci from homologous axes fuse. The distribution and involvement of Rad51 foci as contact points between homologs suggest that they may be components to early recombination nodules. (3) As pachynema progresses the number of foci drops dramatically; the temporal occurrence (mice) and physical and numerical distribution of foci on axes (chickens) suggest that they may be a component of late recombination nodules. (4) In early pachynema there are numerous Rad51 foci on the single axis of the X (mouse spermatocytes) or the Z (chiken oocytes) chromosomes that neither pair, nor recombine. (5) In late pachynema in mouse spermatocytes, but not oocytes, the Rad51 signal is preferentially enhanced at both ends of all the bivalents. As bivalents in spermatocytes, but not oocytes, begin to desynapse at diplonema they are often held together at these Rad51-positive termini. These observations parallel observations that recombination rates are exceptionally high near chromosome ends in male but not female eutherian mammals. (6) From diakinesis through metaphase I, Rad51 protein is detected as low-intensity fluorescent doublets that localize with CREST-specific antigens (kinetochores), suggesting that Rad51 participates, at least as a structural component of the materials involved, in sister kinetochore cohesiveness. Finally, the changes in Rad51 distribution during meiosis do not appear to be species specific, but intrinsic to the meiotic process.

A Routine Method for Oxide and Hydroxide Interference Corrections in ICP‐MS Chemical Analysis of Environmental and Geological Samples

Abstract: Inductively coupled plasma-mass spectrometry has revolutionized the field of multi-elemental analysis because of its high sensitivity and speed of analysis. However, problems with polyatomic ion interferences during routine analysis can give rise to inaccuracies. We propose a method that systematically corrects for oxide and hydroxide interferences in routine analysis, for a wide range of materials. Oxide and hydroxide production for a specified element is calculated from measurements on each sample, as levels may depend on sample composition and may also vary with time. We show that oxide and hydroxide interferences can then be calculated for other elements, by reference to a set of oxide and hydroxide ratios measured on standard solutions. Validity of correction is controlled by internal tests involving two isotopes of one element with respect to experimental errors. The limits and validity of this approach are demonstrated with the analysis of selected reference materials.