Search results for "Limiting"
showing 10 items of 219 documents
Evaluation of two oxygen analyzers by computerized data acquisition and processing
1986
Monitoring of inspired oxygen concentration during anesthesia with nitrous oxide is becoming accepted as essential. This type of monitoring demands accurate monitors that respond rapidly. We evaluated two such devices for their response patterns to rapid changes in oxygen concentration, a galvanic or "fuel cell" unit and a polarographic device. Data were stored after analog-to-digital conversion. The response patterns to stepwise changes in nitrous oxide and oxygen mixtures were recorded at flow rates ranging from 2 to 10 L/min. Both units responded accurately to all changes in the absolute oxygen concentration; the polarographic unit was, on average, twice as fast. Responsiveness to nitrou…
What are the ethical aspects surrounding the collegial decisional process in limiting and withdrawing treatment in intensive care?
2017
International audience; The decision to limit or withdraw life-support treatment is an integral part of the job of a physician working in the intensive care unit, and of the approach to care. However, this decision is influenced by a number of factors. It is widely accepted that a medical decision that will ultimate lead to end-of-life in the intensive care unit (ICU) must be shared between all those involved in the care process, and should give precedence to the patient's wishes (either directly expressed by the patient or in written form, such as advance directives), and taking into account the opinion of the patient's family, including the surrogate if the patient is no longer capable of…
Considerations on the modelling and optimisation of resolution of ionisable compounds in extended pH-range columns
2005
Abstract The problems associated to the modelling and optimisation of the chromatographic resolution of mixtures involving ionisable solutes at varying pH and acetonitrile content are discussed. Several retention models that separate the contributions of solute, column and stationary phase, were used. The retention was predicted with low errors in large pH domains (2–12), which was an essential requirement to face the optimisation of resolution. The selected mixture was particularly problematic under the viewpoint of resolution, owing to the excessively diverse acid–base behaviour of solutes. This variety led to sudden drops in retention at different pH for each solute, yielding numerous pe…
Early assessment of crop yield from remotely sensed water stress and solar radiation data
2018
Soil moisture (SM) available for evapotranspiration is crucial for food security, given the significant interannual yield variability of rainfed crops in large agricultural regions. Also, incoming solar radiation (Rs) influences the photosynthetic rate of vegetated surfaces and can affect productivity. The aim of this work is to evaluate the ability of crop water stress and Rs remotely sensed data to forecast yield at regional scale. Temperature Vegetation Dryness Index (TVDI) was computed as an indicator of crop water stress and soil moisture availability. TVDI during critical growth stage of crops was calculated from MODIS products: MODIS/AQUA 8-day composite LST at 1 km and 16-day compos…
Precipitation responses to ENSO and IOD in the Maldives: Implications of large-scale modes of climate variability in weather-related preparedness
2020
Abstract This research seeks to address the extent to which indices of large-scale modes of climate variability (El Nino Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD)) can be linked to physical differences in the local mean and extreme rainfall conditions experienced in the Maldives in order to suggest implications for disaster risk reduction (DRR). While some significant differences in precipitation metrics do occur at the local level between different phases of the large-scale modes of climate variability studied, they do not occur for all sites studied. While the constrained availability of historical meteorological data in the region is a limiting factor in this analysis, th…
Influence of Nutrients and Mixing on the Primary Production and Community Respiration in the Gulf of Riga
1999
Abstract Rates of plankton community production and respiration in relation to wind, solar radiation, biomass and nutrients were measured in the mixed layer during a late spring, a mid-summer and an early autumn situation in the Gulf of Riga. System metabolism was estimated by the in vitro oxygen method and from oxygen mass balance directly in the water. Gross production (GPP) remained fairly stable throughout the investigation periods with a mean of 1.8 g C m−2 day−1 (range: 0.5–3.9 g C m−2 day−1). Community respiration varied from 0.5 to 6.4 g C m−2 day−1 during the two summer studies (the high respiration rates ranging from 3.0 to 10.4 g C m−2 day−1 found during the autumn cruise were pr…
New trepostomate bryozoans from the Upper Ordovician of Morocco and the temperature influence on zooid size
2015
AbstractNew Upper Ordovician trepostomate bryozoans from the eastern Anti-Atlas of Morocco have been identified. They have been collected from the lower and intermediate units of the Khabt-el-Hajar Formation, late Katian in age, representing, respectively, bryozoan-pelmatozoan meadows with siliciclastic input, degraded by wave activity in a mid-ramp setting, and outer-ramp environments with marly substrates. Ten species of the generaCyphotrypa,Calloporella,Diplotrypa,Parvohallopora,Dekayia, andAostiporaare described. Of them, three species are new:Cyphotrypa regularisJiménez-Sánchez,Parvohallopora cystataJiménez-Sánchez, andAostipora elongataJiménez-Sánchez. Univariate statistical analyses …
Pointer years in tree-ring width and earlywood-vessel area time series of Quercus robur—Relation with climate factors near its northern distribution …
2013
Abstract For a long time, radial growth of pedunculate oak (Quercus robur) in relation to environmental factors has been studied in Central Europe. However, there is insufficient information on oak growth in the Baltic region. Climate–growth interactions have been mostly investigated by correlation/response analysis between ring width and climatic factors. Other wood anatomical proxies, and also pointer year analysis, which focuses on weather extremes, can be sources of additional information. Wood samples were taken from 40 sites across Latvia. Tree-ring width (TRW) and mean area of earlywood vessels (EVA) were measured. To assess differences in wood formation among sites, a PCA was perfor…
Cellular Oxygen Concentration
1976
At low oxygen levels the intracellular or intramitochondrial concentration of molecular oxygen together with the amount of reduced cytochrome oxydase determines the rate of oxygen utilization. Below the so-called “critical oxygen concentration”, i.e. the value, at which a drop in the rate of oxygen uptake has its first evidence, the kinetic is described by the oxygen affinity (Km) of the respiratory chain, i.e. the concentration value for half maximal rate of oxygen uptake.
Suppression of nonlinear Zeeman effect and heading error in earth-field-range alkali-vapor magnetometers
2018
The nonlinear Zeeman effect can induce splitting and asymmetries of magnetic-resonance lines in the geophysical magnetic field range. This is a major source of "heading error" for scalar atomic magnetometers. We demonstrate a method to suppress the nonlinear Zeeman effect and heading error based on spin locking. In an all-optical synchronously pumped magnetometer with separate pump and probe beams, we apply a radio-frequency field which is in-phase with the precessing magnetization. In an earth-range field, a multi-component asymmetric magnetic-resonance line with ? 60 Hz width collapses into a single peak with a width of 22 Hz, whose position is largely independent of the orientation of th…