bluuebunny/crossref_metadata_2025_split huggingface dataset:
The propagation and diurnal cycles of deep convection in northern tropical Africa
Authors: Laing Arlene G. , Carbone Richard , Levizzani Vincenzo , Tuttle John 
Published: March 2008

AbstractThe propagation and diurnal cycle of organized convection in northern tropical Africa are examined using five years (1999–2003) of digital infrared imagery for May–August. Reduced‐dimension techniques are used to document the properties of cold clouds ‐ proxies for deep convection and precipitation. Large‐scale environments are diagnosed from global analyses.Organized convection in Africa consists of coherent sequences or episodes which span an average distance of about 1000 km and last about 25 h. A substantial fraction of events exhibits systematic propagation at regional to continental scales while undergoing decay and regeneration. Episodes with 36 h duration and 1472 km span recur at a one‐per‐day interval. Most episodes have phase speed of 10–20 m s−1, which is faster than most African easterly waves. Convective episodes tend to initiate in the lee of high terrain, consistent with thermal forcing from elevated heat sources. Average diurnal frequency maxima result from the superposition of local diurnal maximum with the delayed‐phase arrival of systems propagating from the east. Propagation occurs with moderate low‐ to mid‐tropospheric shear, which varies with the African easterly jet migration and West African monsoon phases. Frequent deep convection occurs with local shear maxima near high terrain. For the peak monsoon period and for 10°W–10°E, where easterly waves and convective systems are frequent, 35% of cold cloud episodes occur east of the wave trough compared with about 24% to the west. Based on the coherent behaviour of organized, propagating convection, inferences may be made regarding the prediction of precipitation beyond one or two days. Copyright © 2008 Royal Meteorological Society
Bulk formulation of surface fluxes extended to weak‐wind stable conditions
Authors: Mahrt L. 
Published: March 2008

AbstractThe bulk formulation for surface fluxes based on surface‐layer similarity theory is found to be a poor approximation for weak‐wind stably‐stratified conditions. These conditions are often non‐stationary, with very weak turbulence, and have often been excluded from analysis. As a consequence of such exclusion and the failure to account for self‐correlation in the bulk aerodynamic formula for the surface stress, the validity of the similarity theory has been overestimated for weak‐wind stable conditions.Four months of turbulence data from FLOSSII are analysed, in order to generalize the bulk formula to include the influence of the non‐stationary mesoscale motions on the generation of turbulence. The generalization of the bulk formula leads to a more systematic variation of the drag coefficient. Excluding cases of significant non‐stationarity of the wind field also leads to a more systematic behaviour of the drag coefficient, although it removes most of the very stable cases, thus introducing bias. Additional data are required in order to establish confidence in the generalized bulk formula. Copyright © 2008 Royal Meteorological Society
On the onset of bora and the formation of rotors and jumps near a mountain gap
Authors: Gohm Alexander , Mayr Georg J. , Fix Andreas , Giez Andreas 
Published: March 2008

AbstractThis study investigates the onset phase of a strong Adriatic bora windstorm that occurred on 4 April 2002. The target area is a gap about 20 km wide embedded in the coastal mountain barrier of the Dinaric Alps that favours strong jet‐like winds. Airborne‐aerosol back‐scatter lidar measurements on board the DLR Falcon research aircraft, together with surface and upper‐air observations, are used to verify high‐resolution numerical experiments conducted with the mesoscale atmospheric model RAMS and a single‐layer shallow‐water model (SWM). Especially during the breakthrough phase of the bora, the flow at the gap exit exhibits a complex spatial structure and temporal evolution. On a transect through the centre of the gap, a hydraulic jump forms; this is located close to the coast throughout the night, and starts to propagate downstream in the early morning. On a transect through the edge of the gap, a lee‐wave‐induced rotor becomes established, due to boundary‐layer separation. It starts to propagate downstream about two hours after the jump. This flow evolution implies that the onset of strong winds at the coast occurs several hours earlier downstream of the centre of the gap than downwind of the edge of the gap. Consequently, the wind field in the vicinity of Rijeka airport, located downwind of the gap, is strongly inhomogeneous and transient, and represents a potential hazard to aviation. Measured bora winds at the surface exceed 20 ms−1, and the simulated wind speed in the gap wind layer exceeds 30 ms−1. The simulated turbulent kinetic energy exceeds 10 m2 s−2.RAMS indicates that wave‐breaking near a critical level is the dominant mechanism for the generation of the windstorm. Gap jets can be identified downstream of several mountain passes. The simulated wave pattern above the Dinaric Alps, the wave decay with height due to directional wind shear and the strong flow descent on the leeward side of the barrier are supported by measured back‐scatter intensities. Basic bora flow features, including gap jets and jumps, are remarkably well reproduced by SWM simulations. The RAMS reference run captures observed flow phenomena and the temporal flow evolution qualitatively well. A cold low‐level bias, an overestimated bora inversion strength, and a slightly too‐early bora onset are probably related to insufficient turbulent mixing in the boundary layer. The amplitude of trapped gravity waves, the time of the bora breakthrough and the inversion strength are found to be quite sensitive to the turbulence parametrization. Copyright © 2008 Royal Meteorological Society
Phase transformation induced by classical ion implantation in austenitic stainless steel
Authors: Dudognon J. , Vayer M. , Pineau A. , Erre R. 
Published: March 2008

AbstractStructural modifications induced by Cr, Ar, N, Xe, Mo, Ag and Pb ion implantations in a 316LVM austenitic stainless steel within a 70‐nm thick surface layer were studied by grazing incidence X‐ray diffraction. In the implanted layer, austenite lattice expansion was first observed, then ferrite formation and in some cases amorphization. Atomic force microscopy (AFM) was used to study changes in surface topography under ion implantation: roughening, grain boundaries revelation, holes formation. Magnetic force microscopy (MFM) was used to distinguish on the surface ferrite domains when they were formed. Ferrite started to grow at grain boundaries and covered all the surface of the sample in some cases. A theoretical damage level was estimated using SRIM‐2003 computer program. The amount of ferrite and the amorphization rate were considered with respect to the damage level brought in the implanted layer by ion introduction. Existence of damage level thresholds for ferrite formation (200 displacements per atom (dpa)) and amorphization (400 dpa) were considered as evidence. These thresholds were independent of the nature of implanted element and the fluence of implantation. Copyright © 2008 John Wiley & Sons, Ltd.
Psychometric properties of a Persian language version of the Illness Attitude Scale in non‐clinical Iranian populations
Authors: Shaeiri Mohammad Reza , Atrifard Mahdieh , Asghari Ali 
Published: March 2008

AbstractThis paper examines the psychometric properties of a Persian language version of the Illness Attitude Scale (P‐IAS) in two Iranian student samples. After translation of the Illness Attitude Scale from English into Persian and pilot testing, the P‐IAS was used in two studies. In Study 1, the results of principal component analysis with oblique (Oblimin) rotation showed that five factors best explained the P‐IAS structure among 929 students. These factors were (1) fear of illness and disease; (2) frequency of treatment; (3) hypochondriacal beliefs and symptom effects; (4) health behaviours; and (5) thanatophobia. Cronbach's alpha, mean inter‐item correlations and test–retest coefficients showed that this solution was reliable. In Study 2, with a sample of 50 Iranian students, Pearson correlations were calculated between the five factors of the P‐IAS and somatization dimension of the revised Symptom Checklist 90. The results of the second study provided further support for the construct validity of the three factors of fear of illness and disease, frequency of treatment, and hypochondriacal beliefs and symptom effects. The authors suggest that the P‐IAS is sufficiently valid and reliable for clinical and research purposes in the Iranian population. Copyright © 2008 John Wiley & Sons, Ltd.
Implementation Matters: A Review of Research on the Influence of Implementation on Program Outcomes and the Factors Affecting Implementation
Authors: Durlak Joseph A. , DuPre Emily P. 
Published: March 2008

AbstractThe first purpose of this review was to assess the impact of implementation on program outcomes, and the second purpose was to identify factors affecting the implementation process. Results from over quantitative 500 studies offered strong empirical support to the conclusion that the level of implementation affects the outcomes obtained in promotion and prevention programs. Findings from 81 additional reports indicate there are at least 23 contextual factors that influence implementation. The implementation process is affected by variables related to communities, providers and innovations, and aspects of the prevention delivery system (i.e., organizational functioning) and the prevention support system (i.e., training and technical assistance). The collection of implementation data is an essential feature of program evaluations, and more information is needed on which and how various factors influence implementation in different community settings.
Phytoplankton stoichiometry
Authors: Klausmeier C. A. , Litchman E. , Daufresne T. , Levin S. A. 
Published: March 2008

AbstractBecause phytoplankton live at the interface between the abiotic and the biotic compartments of ecosystems, they play an important role in coupling multiple nutrient cycles. The quantitative details of how these multiple nutrient cycles intersect is determined by phytoplankton stoichiometry. Here we review some classic work and recent advances on the determinants of phytoplankton stoichiometry and their role in determining ecosystem stoichiometry. First, we use a model of growth with flexible stoichiometry to reexamine Rhee and Goldman's classic chemostat data. We also discuss a recent data compilation by Hall and colleagues that illustrates some limits to phytoplankton flexibility, and a model of physiological adaptation that can account for these results. Second, we use a model of resource allocation to determine the how the optimal nitrogen‐to‐phosphorus stoichiometry depends on the ecological conditions under which species grow and compete. Third, we discuss Redfield's mechanism for the homeostasis of the oceans’ nitrogen‐to‐phosphorus stoichiometry and show its robustness to additional factors such as iron‐limitation and temporal fluctuations. Finally, we suggest areas for future research.
Multifunctional Magnetic-fluorescent Nanocomposites for Biomedical Applications
Authors: Corr Serena A , Rakovich Yury P , Gun’ko Yurii K 
Published: March 2008

Abstract
Nanotechnology is a fast-growing area, involving the fabrication and use of nano-sized materials and devices. Various nanocomposite materials play a number of important roles in modern science and technology. Magnetic and fluorescent inorganic nanoparticles are of particular importance due to their broad range of potential applications. It is expected that the combination of magnetic and fluorescent properties in one nanocomposite would enable the engineering of unique multifunctional nanoscale devices, which could be manipulated using external magnetic fields. The aim of this review is to present an overview of bimodal “two-in-one” magnetic-fluorescent nanocomposite materials which combine both magnetic and fluorescent properties in one entity, in particular those with potential applications in biotechnology and nanomedicine. There is a great necessity for the development of these multifunctional nanocomposites, but there are some difficulties and challenges to overcome in their fabrication such as quenching of the fluorescent entity by the magnetic core. Fluorescent-magnetic nanocomposites include a variety of materials including silica-based, dye-functionalised magnetic nanoparticles and quantum dots-magnetic nanoparticle composites. The classification and main synthesis strategies, along with approaches for the fabrication of fluorescent-magnetic nanocomposites, are considered. The current and potential biomedical uses, including biological imaging, cell tracking, magnetic bioseparation, nanomedicine and bio- and chemo-sensoring, of magnetic-fluorescent nanocomposites are also discussed.
Flow cytometric cell cycle analysis of cultured brown bear fibroblast cells
Authors: Caamaño J.N. , Rodriguez A. , Salas A. , Muñoz M. , Diez C. , Prather R.S. , Gómez E. 
Published: March 2008

AbstractThe aim of this study was to assess by flow cytometry the cell cycle of brown bear fibroblast cells cultured under different growth conditions. Skin biopsies were taken in Cantabria (Spain) from a live, anaesthetized brown bear. DNA analysis was performed by flow cytometry following cell DNA staining with propidium iodide. Serum starvation increased (P < 0.01) the percentage of G0/G1 phase cells (92.7 ± 0.86) as compared to cycling cells (39.7 ± 0.86) or cells cultured to confluency (87.3 ± 0.86). DMSO included for 48 h in the culture significantly increased (P < 0.01) the percentage of G0/G1 phase of the cell cycle at all concentrations used and decreased percentages of S phase in a dose‐dependent fashion. Roscovitine increased the G0/G1 phase of the cell cycle (P < 0.01) at 15 μM concentration. Interestingly, the G2/M stage significantly increased at 30 and 50 μM compared to the control and 15 μM (P < 0.02). The cell cycle of brown bear adult fibroblast cells can be successfully synchronized under a variety of culture conditions.
Expression of glutamyl aminopeptidase by osteogenic induction in rat bone marrow stromal cells
Authors: Wu Yao , Xiao Jingang , Wu Ling , Tian Weidong , Liu Lei 
Published: March 2008

AbstractGlutamyl aminopeptidase (GluAP, EC 3.4.11.7, ENPEP) is a 130‐kDa homodimeric zinc metallopeptidase which specifically cleaves the N‐terminal glutamate or aspartate residue of peptidic substrates such as cholecystokinin‐8 or angiotensin (Ang) II, in vitro. We used a DNA microarray hybridization (Genechip Rat Expression Array 230A, Affymetrix Inc., Santa Clara, CA, USA) to demonstrate that GluAP was upregulated in osteogenic induced rat bone marrow stromal cells (BMSCs). To compare the expression of GluAP in the osteogenic differentiation and non‐osteogenic differentiation of rat BMSCs in vitro, the cells were osteogenic induced in vitro. We also performed an MTT assay, alkaline phosphatase assay, alizarin red staining, and an immunohistochemical analysis to determine the osteogenic differentiation of BMSCs. The expression of GluAP was examined by real‐time polymerase chain reaction (PCR). The real‐time PCR results showed that GluAP was upregulated in osteogenic differentiated BMSCs in vitro, suggesting that GluAP may be correlated with the osteogenic differentiation of BMSCs.
The mechanism of myoblast deformation in response to cyclic strain—A cytomechanical study
Authors: Zheng Leilei , Song Jinlin , Li Zhihua , Fan Yubo , Zhao Zhihe , Chen Yangxi , Deng Feng , Hu Yun 
Published: March 2008

AbstractMechanical strain is one of the important epigenetic factors that cause deformation and differentiation of skeletal muscles. This research was designed to investigate how myoblast deformation occurs after cyclic strain loading. Myoblasts were passaged three times and harvested; various cyclic strains (2.5 kPa, 5 kPa and 10 kPa) were then loaded using a pulsatile mechanical system. The adaptive response of the myoblasts was observed at different time points (0.5 h, 1 h, 6 h and 12 h) post‐loading. At the early stage of cyclic strain loading (<1 h), almost no visible morphological changes were observed in the myoblasts. The actin cytoskeleton showed a disordered arrangement and a weak fluorescence expression; there was little expression of talin. At 6 h and 12 h post‐loading, the myoblasts changed their orientation to parallel (in the 2.5 kPa and 5 kPa groups) or perpendicular (in the 10 kPa group) to the direction of strain. Fluorescence expression of both the actin cytoskeleton and talin was significantly increased. The results suggest that cyclic strain has at least two ways to regulate adaptation of myoblasts: (1) by directly affecting actin cytoskeleton at an early stage post‐loading to cause depolymerization; and (2) by later chemical signals transmitted from the extracellular side to intracellular side to initiate repolymerization.
Post‐insult minocycline treatment attenuates hypoxia‐ischemia‐induced neuroinflammation and white matter injury in the neonatal rat: a comparison of two different dose regimens
Authors: Carty Michelle L. , Wixey Julie A. , Colditz Paul B. , Buller Kathryn M. 
Published: March 2008

AbstractAn increase in the number of activated microglia in the brain is a key feature of neuroinflammation after a hypoxic–ischemic insult to the preterm neonate and can contribute to white matter injury in the brain. Minocycline is a potent inhibitor of microglia and may have a role as a neuroprotective agent that ameliorates brain injury after hypoxia–ischemia in neonatal animal models. However to date large doses, pre‐insult administration and short periods of treatment after hypoxia–ischemia have mostly been investigated in animal models making it difficult to translate minocycline's potential applicability to protect the human preterm neonatal brain exposed to hypoxia–ischemia. We investigated whether repeated doses of minocycline can minimize white matter injury and neuroinflammation one week after hypoxia–ischemia (right carotid artery ligation and 30 min 6% O2) in the post‐natal day 3 rat pup. Two dosage regimens of minocycline were administered for one week; a high dose of 45 mg/kg 2 h after hypoxia–ischemia then 22.5 mg/kg daily or a low dose 22.5 mg/kg 2 h after hypoxia–ischemia then 10 mg/kg. Post‐natal day 3 hypoxia–ischemia significantly reduced myelin content, numbers of O1‐ and O4‐positive oligodendrocyte progenitor cells and increased activated microglia one week later on post‐natal day 10. The low dose minocycline regimen was as effective as the high dose in ameliorating neuroinflammation after post‐natal day 3 hypoxia–ischemia. However only the high dose regimen significantly attenuated reductions in O1‐ and O4‐positive oligodendrocyte progenitor cells and myelin content. The low dose only significantly attenuated the reduction in O1‐positive oligodendrocyte cell counts. Repeated, daily, post‐insult treatment with minocycline abolished neuroinflammation and may provide neuroprotection to white matter for up to one week after hypoxia–ischemia in a rodent preterm model. The present findings suggest the potential clinical relevance of a repeated, daily minocycline treatment strategy, administered after a hypoxia–ischemia insult, as a therapeutic intervention for hypoxia–ischemia‐affected preterm neonates.
Role of p38 MAPK and pro‐inflammatory cytokines expression in glutamate‐induced neuronal death of neonatal rats
Authors: Chaparro‐Huerta V. , Flores‐Soto M.E. , Gudiño‐Cabrera G. , Rivera‐Cervantes M.C. , Bitzer‐Quintero O.K. , Beas‐Zárate C. 
Published: March 2008

AbstractPro‐inflammatory cytokines TNF‐α, IL‐1β and IL‐6 rises significantly during neuronal damage and activate the signaling p38 MAPK pathway, which is involved in the apoptotic (AP) neuronal death. Systemic administration of glutamate as monosodium salt (MSG) to newborn animals induces neuronal death, however whether neurons die by AP or necrosis through MAPK p38 pathway activation it is unknown. In this study, TNF‐α, IL‐1β and IL‐6 expression levels, AP neuronal death and cellular type that produces TNF‐α was also identified in the cerebral cortex (CC) and striatum (St) of rats at 8, 10, and 14 days of age after neonatal exposure to MSG. TNF‐α production and AP neuronal death was significantly increased in the CC at PD8–10, and in the St in all ages studied by excitotoxicity effect induced with MSG. This effect was completely inhibited by SB203580 (p38 inhibitor) in both regions studied. TNF‐α, IL‐1β and IL‐6 RNAm increased after MSG administration, whereas SB203580 did not modify their expression. These data indicates that neuronal death induced by excitotoxicity appears to be mediated through p38 signaling pathway activated by TNF‐α and their inhibition may have an important neuroprotective role as part of anti‐inflammatory therapeutic strategy.
On equivalence of two approaches in index theory
Authors: Manuilov V. 
Published: March 2008

AbstractThe algebra Ψ(M) of order zero pseudodifferential operators on a compact manifoldMdefines a well-knownC*-extension of the algebraC(S*M) of continuous functions on the cospherical bundleS*M⊂T*Mby the algebra К of compact operators. In his proof of the index theorem, Higson defined and used an asymptotic homomorphismTfromC0(T*M) to К, which plays the role of a deformation for the commutative algebraC0(T*M). Similar constructions exist also for operators and symbols with coefficients in aC*-algebra. Recently we have shown that the image of the above extension under the Connes–Higson construction isTand that this extension can be reconstructed out ofT. That is why the classical approach to the index theory coincides with the one based on asymptotic homomorphisms. But the image of the above extension is defined only outside the zero section ofT*(M), so it may seem that the information encoded in the extension is not the same as that in the asymptotic homomorphism. We show that this is not the case.
INDECOMPOSABILITY GRAPHS OF RINGS
Authors: CVETKO-VAH KARIN , DOLŽAN DAVID 
Published: March 2008

AbstractWe define a subgraph of the zero divisor graph of a ring, associated to the ring idempotents. We study its properties and prove that for large classes of rings the connectedness of the graph is equivalent to the indecomposability of the ring and in those cases we also calculate the graph’s diameter.
Promoter-Proximal Introns in Arabidopsis thaliana Are Enriched in Dispersed Signals that Elevate Gene Expression
Authors: Rose Alan B. , Elfersi Tali , Parra Genis , Korf Ian 
Published: March 2008

Abstract
Introns that elevate mRNA accumulation have been found in a wide range of eukaryotes. However, not all introns affect gene expression, and direct testing is currently the only way to identify stimulatory introns. Our genome-wide analysis in Arabidopsis thaliana revealed that promoter-proximal introns as a group are compositionally distinct from distal introns and that the degree to which an individual intron matches the promoter-proximal intron profile is a strong predictor of its ability to increase expression. We found that the sequences responsible for elevating expression are dispersed throughout an enhancing intron, as is a candidate motif that is overrepresented in first introns and whose occurrence in tested introns is proportional to its effect on expression. The signals responsible for intron-mediated enhancement are apparently conserved between Arabidopsis and rice (Oryza sativa) despite the large evolutionary distance separating these plants.