bluuebunny/crossref_metadata_2025_split huggingface dataset:
Towards a new hybrid cumulus parametrization scheme for use in non‐hydrostatic weather prediction models
Authors: Kuell V. , Gassmann A. , Bott A. 
Published: March 2007

AbstractClassical mass flux parametrization schemes for cumulus convection generally transport heat and moisture only but do not include a net mass transport. This is well justified for large grid spacings comprising the whole convective circulation in the local grid column, such that all convective mass fluxes locally cancel out. A conceptual problem arises for finer grid spacings as used in contemporary numerical weather prediction (NWP) models, when convection becomes partially resolvable. This problem can be overcome by the hybrid approach presented here. Only updraft and downdraft are parametrized with a net mass transport; the environmental subsidence is treated by the grid‐scale equations. The total mass flux in the continuity equation is split into a grid‐scale and a subgrid‐scale contribution. This parametrization scheme is designed for use in any nonlinear, non‐hydrostatic and fully compressible NWP model. We here have chosen the Lokal–Modell (LM) of Deutscher Wetterdienst.Idealized dry mass lifting experiments (without convective heat transport) demonstrate the feasibility of the hybrid approach. Entrainment causes grid‐scale convergence and the detrained air, if set to the environmental temperature, spreads mainly horizontally on the grid. Gravity waves are generated when convection starts and ends. Whereas their amplitude depends on the details of the switching on and off of convection, the stationary state (after about 30 minutes) does not. Four model runs with different grid spacings (3.5 km to 28 km) confirm that the mass exchange between the model grid and the parametrization scheme is independent of the chosen grid spacing. Total mass in a convective circulation cell is conserved to better than 0.1%, but only if the damping layer at the upper boundary of the LM is shifted to above 20 km.For moist convection (with convective heat transport), a simple cloud model for an updraft has been set up. As the detrained air at the cloud top is colder than the environment, it moves down by about 1 km but then mainly spreads horizontally again over several tens of kilometres as in the dry case without convective heat transport.The hybrid mass flux approach with both a grid‐scale and a subgrid‐scale contribution may fill the gap between coarse‐grid models (grid spacing > 50 km) with classical parametrization schemes, and very highly resolved explicit convection modelling (with a grid spacing of the order of 100 m). Copyright © 2007 Royal Meteorological Society
Boundary layer mechanisms in extratropical cyclones
Authors: Beare Robert J. 
Published: March 2007

AbstractThis paper revisits the mechanism for the interaction of the boundary layer with extratropical cyclones. Two diagnostic approaches are compared: Ekman pumping and potential vorticity. Ekman pumping derives from the boundary layer stress which induces convergence and ascent. boundary layer potential vorticity contains in a single quantity both the vorticity and stratification. These quantities are compared for an idealized extratropical cyclone life cycle simulated with the Met Office Unified Model.A significant component of the boundary layer stress and thus Ekman pumping at occlusion is forced by the cold conveyor‐belt jet in the unstable boundary layer. In contrast, much of the boundary layer depth‐averaged potential vorticity is contained within the stable warm‐sector region. Inversion of the warm‐sector PV indicates a small local deepening of about 2.5 hPa. Moreover, switching off the boundary layer mixing in the unstable cold sector has much more impact than in the stable warm sector.The sensitivity of the cyclone and its boundary layer to basic‐state jet strength is then investigated. The maximum friction velocity scales closely with the initial maximum jet strength. This demonstrates the important role of the large‐scale flow in organizing the boundary layer structure. Changes in the minimum pressure produced by altering the boundary layer parametrization correspond closely to changes in the surface stress averaged over the cyclone. Different operational changes to the boundary layer scheme produce small and compensating changes to the cyclone minimum pressure over three days. © Crown Copyright 2007. Reproduced with the permission of the Controller of HMSO. Published by John Wiley & Sons, Ltd
The Met Office global four‐dimensional variational data assimilation scheme
Authors: Rawlins F. , Ballard S. P. , Bovis K. J. , Clayton A. M. , Li D. , Inverarity G. W. , Lorenc A. C. , Payne T. J. 
Published: March 2007

AbstractThe Met Office has developed a 4D‐Var data assimilation system, which was implemented in the global forecast system on 5 October 2004. This followed a development path based on the previous 3D‐Var configuration, with many aspects kept in common. A 4D‐Var capability was provided by the introduction of a linear perturbation forecast model based on the Unified Model, the non‐hydrostatic grid‐point model producing our operational forecasts.There were clear advantages in verification of forecasts compared to the equivalent 3D‐Var configuration, with an improvement of 2.6% in a composite skill score verified against observations during pre‐operational trials. The largest differences in model evolution occur in storm‐track regions in the extratropics. Overall, improvements in verification scores as measured against observations were larger than those measured against analyses, particularly at upper levels. There is an improvement in verification of surface parameters (10 m wind, 1.5 m temperature and relative humidity) against analyses. The strongest impact on fitting observations is seen for satellite radiances with weighting functions peaking in the stratosphere and upper troposphere. The largest changes to assimilation increments occurred in the top model levels, particularly wind increments which became much larger near the model top.Similarities were found in the signal of 4D‐Var versus 3D‐Var for models at two different resolutions, from which we infer that low‐resolution trials remain valid for exploring some aspects of 4D‐Var before confirmation in full‐scale tests. © Crown Copyright 2007. Reproduced with the permission of the Controller of HMSO. Published by John Wiley & Sons, Ltd
Role of the quasi‐biweekly oscillation in the onset of convection over the Indochina Peninsula
Authors: Wen Min , Zhang Renhe 
Published: March 2007

AbstractThe characteristics of convection onset over the Indochina Peninsula and its possible mechanism are investigated using the reanalysis of the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) and the black‐body temperature at the top of the cloud (TBB). Results show that the convection onset occurs before the systemic northward progression of the tropical convection and is earlier than the onset of the summer monsoon over this region. The prominent difference between the onset of convection and that of the summer monsoon appears in the westmost part of the western Pacific subtropical high. When the convection bursts, the Indochina Peninsula is under the control of the western Pacific subtropical high. However, the summer monsoon onset follows the splitting of the subtropical high belt and the eastward retreat of the western Pacific subtropical high out of the Indochina Peninsula.The climatological features of TBB over the Indochina Peninsula indicate that the convective activities have a close relationship with the quasi‐biweekly oscillation (QBWO). Based on the onset dates determined by the TBB data, case‐studies and composite analyses are implemented on exploring the possible mechanism of the convection onset. It is found that the onset of convection is mainly influenced by factors as follows. The wet phase of QBWO of the tropical convection propagates northward from Sumatra to the Indochina Peninsula. Over the southern Indochina Peninsula, anomalous southerlies (the Rossby wave response to the tropical convective QBWO) are beneficial to both the northward progression of the convective disturbances and the convergence of the low‐level moisture flux. Furthermore, the Indochina Peninsula is easily affected by any cold surge invading southwards from higher latitudes, which intensifies the convective activities when merging with the wet/warm current. Copyright © 2007 Royal Meteorological Society
‘N‐in‐one’ strategy for metabolite identification using a liquid chromatography/hybrid triple quadrupole linear ion trap instrument using multiple dependent product ion scans triggered with full mass scan
Authors: Li Austin C. , Gohdes Mark A. , Shou Wilson Z. 
Published: March 2007

AbstractThis paper describes a new strategy that utilizes the fast trap mode scan of the hybrid triple quadrupole linear ion trap (QqQLIT) for the identification of drug metabolites. The strategy uses information‐dependent acquisition (IDA) where the enhanced mass scan (EMS), the trap mode full scan, was used as the survey scan to trigger multiple dependent enhanced product ion scans (EPI), the trap mode product ion scans. The single data file collected with this approach not only includes full scan data (the survey), but also product ion spectra rich in structural information. By extracting characteristic product ions from the dependent EPI chromatograms, we can provide nearly complete information for in vitro metabolites that otherwise would have to be obtained by multiple precursor ion scan (prec) and constant neutral loss (NL) analysis. This approach effectively overcomes the disadvantages of traditional prec and NL scans, namely the slow quadrupole scan speed, and possible mass shift. Using nefazodone (NEF) as the model compound, we demonstrated the effectiveness of this strategy by identifying 22 phase I metabolites in a single liquid chromatography/tandem mass spectrometry (LC/MS/MS) run. In addition to the metabolites reported previously in the literature, seven new metabolites were identified and their chemical structures are proposed. The oxidative dechlorination biotransformation was also discovered which was not reported in previous literature for NEF. The strategy was further evaluated and worked well for the fast discovery setting when a ballistic gradient elution was used, as well as for a simulated in vivo setting when the incubated sample (phase I metabolites) was spiked to control human plasma extract and control human urine. Copyright © 2007 John Wiley & Sons, Ltd.
Determination of hydrogen, carbon and oxygen isotope ratios of ethanol in aqueous solution at millimole levels
Authors: Yamada Keita , Yoshida Naohiro , Calderone Giovanni , Guillou Claude 
Published: March 2007

AbstractThree stable isotope ratios, D/H, 13C/12C and 18O/16O, are measurable in ethanol, an important organic compound that is used as a material for food and beverages, fuel and chemical feedstock, and as a substance related to metabolism. We developed a simple and rapid method of measurement of three isotope ratios of ethanol in aqueous solution at millimole levels using gas chromatography‐high‐temperature conversion or combustion‐isotope ratio mass spectrometry (GC‐TC/C‐IRMS) combined with solid‐phase microextraction (SPME). Using this method, the δ value for ethanol was determined in 30 min for δD and δ13C, and in 75 min for δ18O with precisions of ±9‰, ±0.3‰ and ±0.7‰, respectively, for δD, δ13C, and δ18O. An advantage of this process is that it requires no distillation for ethanol purification. The method is useful for small quantities of analyte with low ethanol concentrations, which is expected for environmental and metabolic studies. Copyright © 2007 John Wiley & Sons, Ltd.
Detection and sequence determination of a new variant β‐lactoglobulin II from donkey
Authors: Cunsolo Vincenzo , Costa Alessia , Saletti Rosaria , Muccilli Vera , Foti Salvatore 
Published: March 2007

AbstractThe sequence determination of a new variant of β‐LG II, detected as a minor component by reversed‐phase high‐performance liquid chromatography/electrospray ionization mass spectrometry (RP‐HPLC/ESI‐MS) analysis of the whey fraction from a milk sample taken from an individual donkey belonging to the ‘Ragusana’ species of eastern Sicily, is reported. Direct RP‐HPLC/ESI‐MS analysis of the whey fraction from this milk sample allowed the identification of a new variant of β‐LG II, based on the determination of the Mr of the intact protein. The new protein, with an experimentally determined Mr of 18311 Da, was detected as a minor component in the whey fraction investigated. Matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF)MS and RP‐HPLC/ESI‐MS/MS analyses of the tryptic digest of the new protein demonstrate that it presents two amino acid substitutions with respect to the sequence of β‐LG II A, namely a substitution Pro→Cys at position 110, and a substitution Asp→Gly at position 162. The disulfide bonds between the four cysteines, not directly determined in donkey's and horse's β‐LG II, were shown to occur between Cys106‐Cys120 and Cys66‐Cys161, as in other mammalian β‐LGs. The new β‐LG II variant from donkey was named D. Copyright © 2007 John Wiley & Sons, Ltd.
Iowa radon leukaemia study: a hierarchical population risk model for spatially correlated exposure measured with error
Authors: Smith Brian J. , Zhang Lixun , Field R. William 
Published: March 2007

AbstractThis paper presents a Bayesian model that allows for the joint prediction of county‐average radon levels and estimation of the associated leukaemia risk. The methods are motivated by radon data from an epidemiologic study of residential radon in Iowa that include 2726 outdoor and indoor measurements. Prediction of county‐average radon is based on a geostatistical model for the radon data which assumes an underlying continuous spatial process. In the radon model, we account for uncertainties due to incomplete spatial coverage, spatial variability, characteristic differences between homes, and detector measurement error. The predicted radon averages are, in turn, included as a covariate in Poisson models for incident cases of acute lymphocytic (ALL), acute myelogenous (AML),
chronic lymphocytic (CLL), and chronic myelogenous (CML) leukaemias reported to the Iowa cancer registry from 1973 to 2002. Since radon and leukaemia risk are modelled simultaneously in our approach, the resulting risk estimates accurately reflect uncertainties in the predicted radon exposure covariate. Posterior mean (95 per cent Bayesian credible interval) estimates of the relative risk associated with a 1 pCi/L increase in radon for ALL, AML, CLL, and CML are 0.91 (0.78–1.03), 1.01 (0.92–1.12), 1.06 (0.96–1.16), and 1.12 (0.98–1.27), respectively. Copyright © 2007 John Wiley & Sons, Ltd.
The relevance of situation awareness in older adults’ cognitive functioning: a review
Authors: Caserta Ryan J. , Abrams Lise 
Published: March 2007

Abstract
Age-related declines in cognition may have detrimental effects on older adults’ ability to complete everyday activities that young- and middle-aged individuals perform automatically. Theories of cognitive aging have found deficits in older adults’ fluid intelligence, capacity for inhibition, number of processing resources, and speed of processing, and in recent years, studies have proposed cognitive strategies to ameliorate these declines. However, few strategies directly train the cognitive strategies necessary to improve performance in dynamic environments and physical activities. One such strategy may be the enhancement of situation awareness, the capability to perceive and understand one’s environment. Although the term has typically been applied to pilots and other expert performers, situation awareness may also be relevant to cognitive aging, where older adults’ perception and comprehension of their environment become critical to everyday functioning and physical activities. If older adults’ situation awareness can be facilitated, then it may be possible to reduce the impact of age-related cognitive declines, allowing older adults to successfully participate in dynamic situations and sports where the environment is constantly changing (e.g., driving and tennis). The following review outlines cognitive deficits in aging, details their relation to situation awareness, and discusses how training in situation awareness may reduce cognitive declines.
Astonishing diversity of natural surfactants: 2. Polyether glycosidic ionophores and macrocyclic glycosides
Authors: Dembitsky Valery M. 
Published: March 2007

AbstractPolyether glycosidic ionophores and macrocyclic glycosides are of great interest, especially for the medicinal and pharmaceutical industries. These biologically active natural surfactants are good prospects for the future chemical preparation of compounds useful as antibiotics, anticancer agents, or in industry. More than 300 interesting and unusual natural surfactants are described in this review article, including their chemical structures and biological activities.
Tissue‐dependent alterations in lipid mass in mice lacking glycerol kinase
Authors: Golovko Mikhail Y. , Hovda Johnathan T. , Cai Zong‐Jin , Craigen William J. , Murphy Eric J. 
Published: March 2007

AbstractGlycerol kinase (ATP:glycerol‐3‐phosphotransferase, EC 2.7.1.30, glycerokinase) (Gyk) has a central role in plasma glycerol extraction and utilization by tissues for lipid biosynthesis. Gyk deficiency causes various phenotypic changes ranging from asymptomatic hyperglycerolemia to a severe metabolic disorder with growth and psychomotor retardation. To better understand the potential role of Gyk in tissue lipid metabolism, we determined phospholipid (PL), cholesterol (Chol), and triacylglycerol (TG) mass in a number of tissues from mice lacking Gyk. We report a tissue‐dependent response to Gyk gene deletion. Tissues with elevated total PL mass (brain, kidney, muscle) were characterized by the increased mass of ethanolamine glycerophospholipids (EtnGpl), choline glycerophospholipids, and phosphatidylserine (PtdSer). In heart, lipid changes were characterized by a reduction in total PL, including decreased EtnGpl, phosphatidylinositol, and PtdSer mass and decreased TG and FFA mass. In parallel with tissue PL alterations, tissue Chol was also changed, maintaining a normal Chol/PL ratio. Under conditions of Gyk deficiency, we speculate that glycerol‐3‐phosphate and lipid production is maintained via alternative biosynthesis, including glycolysis, glyceroneogenesis, or by direct acylation of glycerol in brain, muscle, kidney, and liver, but not in heart.
Vaccenic acid metabolism in the liver of rat and bovine
Authors: Gruffat Dominique , De La Torre Anne , Chardigny Jean‐Michel , Durand Denys , Loreau Olivier , Bauchart Dominique 
Published: March 2007

AbstractHepatic metabolism of vaccenic acid (VA), especially its conversion into CLA, was studied in the bovine (ruminant species that synthesizes CLA) and in the rat (model for nonruminant) by using the in vitro technique of liver explants. Liver tissue samples were collected from fed animals (5 male Wistar rats and 5 Charolais steers) and incubated at 37°C for 17 h under an atmosphere of 95% O2/5% CO2 in medium supplemented with 0.75 mM of FA mixture and with 55 μM [1‐14C]VA. VA uptake was about sixfold lower in bovine than in rat liver slices (P<0.01). For both species, VA that was oxidized to partial oxidation products represented about 20% of VA incorporated by cells. The chemical structure of VA was not modified in bovine liver cells, whereas in rat liver cells, 3.2% of VA was converted into 16∶0 and only 0.33% into CLA. The extent of esterification of VA was similar for both animal species (70–80% of incorporated VA). Secretion of VA as part of VLDL particles was very low and similar in rat and bovine liver (around 0.07% of incorporated VA). In conclusion, characteristics of the hepatic metabolism of VA were similar for rat and bovine animals, the liver not being involved in tissue VA conversion into CLA in spite of its high capacity for FA desaturation especially in the rat. This indicates that endogenous synthesis of CLA should take place exclusively in peripheral tissues.
Foam fractionation of exo‐lipases from a growing fungus (Pleurotus sapidus)
Authors: Linke Diana , Zorn Holger , Gerken Birte , Parlar Harun , Berger Ralf G. 
Published: March 2007

AbstractActive lipases were isolated from the culture supernatant of the basidiomycetous fungus Pleurotus sapidus by foam fractionation. The pH value, the gas flow, and the foaming period were systematically varied to optimize the transport of the enzymes into the foam phase. On a 70‐mL scale, a maximum recovery of hydrolytic activity of 95% was obtained at pH 7.0 and 60 mL N2 min−1 after 50 min. The procedure, with minor modifications, was also applicable to native pellet cultures of P. sapidus. The same recovery of 95% was achieved, with purification and enrichment factors of 11.6 and 28.0, respectively.
Influence of cytochrome c on apoptosis induced by Anagrapha (Syngrapha) falcifera multiple nuclear polyhedrosis virus (AfMNPV) in insect Spodoptera litura cells
Authors: Liu Lijun , Peng Jianxin , Liu Kaiyu , Yang Hong , Li Yi , Hong Huazhu 
Published: March 2007

AbstractWe investigated the influence of cytochrome c on apoptosis induced by Anagrapha (Syngrapha) falcifera multiple nuclear polyhedrosis virus (AfMNPV). Microscopic observation revealed that infection of SL‐1 cells with AfMNPV resulted in apoptosis, displaying apoptotic bodies in fluorescent‐stained nuclei of AfMNPV‐infected SL‐1cells. Western blot analysis demonstrated that AfMNPV‐induced apoptosis in insect SL‐1 cells was significantly inhibited by cyclosporin A which blocked a translocation of cytochrome c from the mitochondria to the cytosol. As determined by using AC‐DEVD‐AFC as substrate, the activity of caspase‐3 in AfMNPV‐induced cells was detected as early as 4 h post infection, gradually increased with time extension, and reached a highest level after 16 h of infection. However, activity of caspase‐3 in apoptotic cells decreased in the presence of cyclosporin A (30 μM), indicating that activation of caspase‐3 in SfaMNPV‐induced cells was dependent on the release of cytochrome c from the mitochondria. In addition, cyclosporin A could markedly inhibit mitochondrial transmembrane potential (ΔΨm) disruption in undergoing apoptotic cells. These data indicate that cytochrome c plays a key role in AfMNPV‐induced apoptosis in S. litura cells and may be required for caspase activation during the induction of apoptosis.
Conventional and molecular cytogenetic diagnostic methods in stem cell research: A concise review
Authors: Catalina Purificación , Cobo Fernando , Cortés José L. , Nieto Ana I. , Cabrera Carmen , Montes Rosa , Concha Ángel , Menendez Pablo 
Published: March 2007

AbstractRegenerative medicine and cell therapy are emerging clinical disciplines in the field of stem cell biology. The most important sources for cell transplantation are human embryonic and adult stem cells. The future use of these human stem cell lines in humans requires a guarantee of exhaustive control with respect to quality control, safety and traceability. Genetic instability and chromosomal abnormalities represent a potential weakness in basic studies and future therapeutic applications based on these stem cell lines, and may explain, at least in part, their usual tumourigenic properties. So, the introduction of the cytogenetic programme in the determination of the chromosomal stability is a key point in the establishment of the stem cell lines. The aim of this review is to provide readers with an up‐to‐date overview of all the cytogenetic techniques, both conventional methods and molecular fluorescence methods, to be used in a stem cell bank or other stem cell research centres. Thus, it is crucial to optimize and validate their use in the determination of the chromosomal stability of these stem cell lines, and assess the advantages and limitations of these cutting‐edge cytogenetic technologies.