bluuebunny/crossref_metadata_2025_split huggingface dataset:
High‐order semi‐implicit time‐integrators for a triangular discontinuous Galerkin oceanic shallow water model
Authors: Giraldo F. X. , Restelli M. 
Published: July 2009

AbstractWe extend the explicit in time high‐order triangular discontinuous Galerkin (DG) method to semi‐implicit (SI) and then apply the algorithm to the two‐dimensional oceanic shallow water equations; we implement high‐order SI time‐integrators using the backward difference formulas from orders one to six. The reason for changing the time‐integration method from explicit to SI is that explicit methods require a very small time step in order to maintain stability, especially for high‐order DG methods. Changing the time‐integration method to SI allows one to circumvent the stability criterion due to the gravity waves, which for most shallow water applications are the fastest waves in the system (the exception being supercritical flow where the Froude number is greater than one). The challenge of constructing a SI method for a DG model is that the DG machinery requires not only the standard finite element‐type area integrals, but also the finite volume‐type boundary integrals as well. These boundary integrals pose the biggest challenge in a SI discretization because they require the construction of a Riemann solver that is the true linear representation of the nonlinear Riemann problem; if this condition is not satisfied then the resulting numerical method will not be consistent with the continuous equations. In this paper we couple the SI time‐integrators with the DG method while maintaining most of the usual attributes associated with DG methods such as: high‐order accuracy (in both space and time), parallel efficiency, excellent stability, and conservation. The only property lost is that of a compact communication stencil typical of time‐explicit DG methods; implicit methods will always require a much larger communication stencil. We apply the new high‐order SI DG method to the shallow water equations and show results for many standard test cases of oceanic interest such as: standing, Kelvin and Rossby soliton waves, and the Stommel problem. The results show that the new high‐order SI DG model, that has already been shown to yield exponentially convergent solutions in space for smooth problems, results in a more efficient model than its explicit counterpart. Furthermore, for those problems where the spatial resolution is sufficiently high compared with the length scales of the flow, the capacity to use high‐order (HO) time‐integrators is a necessary complement to the employment of HO space discretizations, since the total numerical error would be otherwise dominated by the time discretization error. In fact, in the limit of increasing spatial resolution, it makes little sense to use HO spatial discretizations coupled with low‐order time discretizations. Published in 2009 by John Wiley & Sons, Ltd.
STAT1/IRF‐1 signaling pathway mediates the injurious effect of interferon‐gamma on oligodendrocyte progenitor cells
Authors: Wang Yan , Ren Zhihua , Tao Duan , Tilwalli Shilpa , Goswami Rajendra , Balabanov Roumen 
Published: July 2009

AbstractInterferon‐gamma (IFN‐γ) is a pleiotropic cytokine that is critically involved in the pathogenesis of inflammatory demyelinating diseases. There is strong evidence that IFN‐γ can function as a distinct and independent injurious factor to oligodendrocyte progenitor cells (OPCs). The intracellular signaling pathways leading to OPC death, however, remain poorly understood. In this study, we examined IFN‐γ signaling in OPCs in relation to cell death in vitro. Using expression knock‐down and forced overexpression methods, we directly demonstrated the role of signal transducer and transcription activator 1 (STAT1) and interferon‐regulated factor 1 (IRF‐1) in IFN‐γ‐ induced OPC death. In addition, our study identified two proapoptotic genes, caspase 1 and double‐stranded RNA‐dependent protein kinase (PKR), whose expression was upregulated by IFN‐γ and transcriptionally controlled by IRF‐1. The conclusion of this study is that STAT1 and IRF‐1 function as components of the signaling pathway that mediates IFN‐γ‐induced OPC death. © 2009 Wiley‐Liss, Inc.
MAPK induces AQP1 expression in astrocytes following injury
Authors: Mccoy Eric , Sontheimer Harald 
Published: July 2009

AbstractAquaporin‐4 (AQP4) is the principle water channel and the primary route for water transport across astrocytic membranes. AQP4 co‐localizes with Kir4.1 channels at astrocytic endfeet, and it has been suggested that these channels cooperate in K+ and water homeostasis. In response to injury, two additional aquaporins, AQP1 and AQP9, can be detected in astrocytes, yet neither is found in cultured astrocytes, and therefore their contribution to astrocyte water uptake and biology is poorly investigated. In this study, we used a cortical stab wound assay to demonstrate an upregulation of AQP1 following injury in reactive glia. We were able to mimic such injury in astrocytic cultures and show that AQP1 expression is induced within 16 h following injury in vitro. This induction could be blocked by inhibition of MEK1/2 using U0126, and suggests that AQP1 is specifically induced in reactive astrocytes via the mitogen‐activated protein kinases signaling pathway. © 2009 Wiley‐Liss, Inc.
APOE epsilon‐4 allele and cytokine production in Alzheimer's disease
Authors: Olgiati Paolo , Politis Antonis , Malitas Petros , Albani Diego , Dusi Sabrina , Polito Letizia , De Mauro Stefania , Zisaki Aikaterini , Piperi Christina , Stamouli Evangelia , Mailis Antonis , Batelli Sara , Forloni Gianluigi , De Ronchi Diana , Kalofoutis Anastasios , Liappas Ioannis , Serretti Alessandro 
Published: July 2009

AbstractObjectiveThe APOE epsilon‐4 allele has consistently emerged as a susceptibility factor for Alzheimer's disease (AD). Pro‐inflammatory cytokines are detectable at abnormal levels in AD, and are thought to play a pathophysiological role. Animal studies have shown dose‐dependent correlations between the number of APOE epsilon‐4 alleles and the levels of pro‐inflammatory cytokines. The aims of this study were to investigate the influence of APOE genotypes on TNF‐α, IL‐6, and IL‐1β secreted by peripheral blood mononuclear cells (PBMC) from human patients with AD and to analyze the correlation between cytokine production and AD clinical features.MethodsOutpatients with AD (n = 40) were clinically evaluated for cognitive decline (MMSE) and psychiatric symptoms (Cornell Scale for Depression in Dementia; Neuropsychiatric Inventory) and genotyped for APOE variants. PBMCs were isolated from the donors and used to assess spontaneous and PMA‐stimulated secretion of TNF‐α, IL‐6, and IL‐1β. Cytokine production was determined by immuno‐enzymatic assays (ELISA).ResultsIn comparison with their counterparts without APOE4, patients with at least one copy of the APOE epsilon‐4 allele showed higher spontaneous (p = 0.037) and PMA‐induced (p = 0.039) production of IL‐1β after controlling for clinical variables. Significant correlations were reported between NPI scores (psychotic symptoms) and IL‐6 production.ConclusionThese preliminary findings suggest the involvement of inflammatory response in the pathogenic effect of the APOE epsilon‐4 allele in AD, although their replication in larger samples is mandatory. The modest correlations between pro‐inflammatory cytokines released at peripheral level and AD features emphasizes the need for further research to elucidate the role of neuroinflammation in pathophysiology of AD. Copyright © 2009 John Wiley & Sons, Ltd.
Rapid response to paroxetine is associated with plasma paroxetine levels at 4 but not 8 weeks of treatment, and is independent of serotonin transporter promoter polymorphism in Japanese depressed patients
Authors: Yoshimura Reiji , Umene‐Nakano Wakako , Suzuki Akihito , Ueda Nobuhisa , Miyamoto Kyoko , Ikenouchi‐Sugita Atsuko , Hori Hikaru , Otani Koichi , Nakamura Jun 
Published: July 2009

AbstractIn the present study, we investigated the relationship between the serotonin transporter gene linked polymorphic regions (5‐HTTLPR) or plasma paroxetine levels and clinical response to paroxetine in depressed patients. Sixty patients who met the DSM‐IV criteria for major depressive disorder were enrolled in the study. Twenty‐two were male and 38 were female, with ages ranging from 25 to 71 (mean ± SD = 42 ± 16) years. The clinical improvement of patients was assessed using the Hamilton rating scale for depression (Ham‐D) before and every week after paroxetine administration. According to the data reported previously, patients with an at least 50% decrease in their Ham‐D score were classified as responders. The results showed that the plasma paroxetine levels at 4 weeks were significantly higher in responders (rapid responders) than in nonresponders. On the other hand, no significant associations were found between the L genotype (L/L, L/S) or S genotype (S/S) and the response rates either at 4 weeks or 8 weeks. These results suggest that patients with higher plasma levels at 4 weeks might respond rapidly to paroxetine treatment, but the final response rate at 8 weeks will be independent of the plasma paroxetine levels and the 5‐HTTLPR L/S genotype. Copyright © 2009 John Wiley & Sons, Ltd.
The effects of energy drinks alone and with alcohol on neuropsychological functioning
Authors: Curry Kim , Stasio Michael J. 
Published: July 2009

AbstractObjectiveCaffeinated energy drinks—alone or with alcohol—are heavily marketed to young adults, many of whom believe that caffeine counteracts some negative effects of alcohol intoxication. While the effects of caffeine and alcohol have been widely investigated, few studies have examined neuropsychological performance after consumption of a beverage containing both ingredients.MethodsIn a double‐blind, placebo‐controlled design, 27 non‐caffeine‐deprived female participants were randomly assigned to consume a caffeinated energy drink alone, one containing alcohol, or a non‐alcoholic, non‐caffeinated control beverage. Pre‐ and post‐test assessments were conducted using alternate forms of the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS).ResultsParticipants who consumed the energy drink plus alcohol evidenced significantly lower post‐test performance on a global score of neuropsychological status. Specifically, deficits were found in both visuospatial/constructional and language performance scores. While participants who consumed the caffeinated beverage alone trended toward improved attention scores, neuropsychological status did not show meaningful changes from the pre‐ to post‐test.ConclusionsConsumption of an energy drink containing 6% alcohol by volume negatively influenced performance on a global measure of cognitive functioning. Copyright © 2009 John Wiley & Sons, Ltd.
Input data selection for solar radiation estimation
Authors: Ahmadi Azadeh , Han Dawei , Karamouz Mohammad , Remesan Renji 
Published: July 2009

AbstractModel input data selection is a complicated process, especially for non‐linear dynamic systems. The questions on which inputs should be used and how long the training data should be for model development have been hard to solve in practice. Despite the importance of this subject, there have been insufficient reports in the published literature about inter‐comparison between different model input data selection techniques. In this study, several methods (i.e. the Gamma test, entropy theory, AIC (Akaike's information criterion)/BIC (Bayesian information criterion) have been explored with the aid of non‐linear models of LLR (local linear regression) and ANN (artificial neural networks). The methodology is tested in estimation of solar radiation in the Brue Catchment of England. It has been found that the conventional model selection tools such as AIC/BIC failed to demonstrate their functionality. Although the entropy theory is quite powerful and efficient to compute, it failed to pick up the best input combinations. On the other hand, it is very encouraging to find that the new Gamma test was able to choose the best input selection. However, it is surprising to note that the Gamma test significantly underestimated the required training data while the entropy theory did a better job in this aspect. This is the first study to compare the performance of those techniques for model input selections and still there are many unsolved puzzles. Copyright © 2009 John Wiley & Sons, Ltd.
Application of connectivity theory to model the impact of terrace failure on runoff in semi‐arid catchments
Authors: Meerkerk A. L. , van Wesemael B. , Bellin N. 
Published: July 2009

AbstractTerraces are a common feature of Mediterranean landscapes. In many places they are no longer maintained so that the number of intact terraces is in prolonged decline. The aim of this paper is to examine the effect of terrace removal and failure on hydrological connectivity and peak discharge in an agricultural catchment (475 ha) in south‐east Spain. The situation of 2006 is compared to that in 1956 and to a scenario without terraces (S2). The spatial distribution of concentrated flow was mapped after four storms in 2006. The degree of connectivity was quantified by means of connectivity functions and related to storm characteristics, land use and topography. For 1956, 2006 and scenario S2, connectivity functions and peak discharge to the river were determined for a storm with a return period of 8·2 years. The results show that the decrease in intact terraces has led to a strong increase in connectivity and discharge. The contributing area to the river system has increased by a factor 3·2 between 1956 and 2006. If all terraces were to be removed (scenario S2), the contributing area may further increase by a factor 6·0 compared to 2006. The spatial extent of concentrated flow and the degree of connectivity are related to storm magnitude as expressed by the erosivity index (EI30). Although a large part of the concentrated flow (25–50%) occurs on dirt roads, it appears that croplands become a major source of runoff with increasing rainfall. The results suggest that connectivity theory can be used to improve rainfall–runoff models in semi‐arid areas. Copyright © 2009 John Wiley & Sons, Ltd.
Surgical applications of femtosecond lasers
Authors: Chung Samuel H. , Mazur Eric 
Published: July 2009

AbstractFemtosecond laser ablation permits non‐invasive surgeries in the bulk of a sample with submicrometer resolution. We briefly review the history of optical surgery techniques and the experimental background of femtosecond laser ablation. Next, we present several clinical applications, including dental surgery and eye surgery. We then summarize research applications, encompassing cell and tissue studies, research on C. elegans, and studies in zebrafish. We conclude by discussing future trends of femtosecond laser systems and some possible application directions. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Changes in the physical structure and chain dynamics of elastin network in homocysteine‐cultured arteries
Authors: Samouillan Valérie , Lamy Edouard , Dandurand Jany , Foucault‐Bertaud Alexandrine , Chareyre Corinne , Lacabanne Colette , Charpiot Philippe 
Published: July 2009

AbstractThe thermal and dielectric properties of the elastin network were investigated in arteries cultured with physiological and pathological concentrations of homocysteine, an aminoacid responsible of histological impairments in human arteries. The physical structure of this amorphous protein was investigated by differential scanning calorimetry (DSC). To explore the molecular dynamics of the elastin network in the nanometer range, we used thermally stimulated currents (TSC), a dielectric technique running at low frequency, and measuring the dipolar reorientations in proteins subjected to a static electrical field. Combining DSC and TSC experiments reveals the molecular mobility of the proteins, both in the glassy state and in the liquid state. Significant differences are evidenced in the physical structure and relaxation behavior of elastin network in cultured arteries (physiological and pathological concentrations of homocysteine) and discussed. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Gas‐phase reactions of XH3+ (X = C, Si, Ge) with NF3: a comparative investigation on the detailed mechanistic aspects
Authors: Antoniotti Paola , Operti Lorenza , Rabezzana Roberto , Turco Francesca , Zanzottera Cristina , Giordani Maria , Grandinetti Felice 
Published: July 2009

AbstractThe gas‐phase reaction of CH3+ with NF3 was investigated by ion trap mass spectrometry (ITMS). The observed products include NF2+ and CH2F+. Under the same experimental conditions, SiH3+ reacts with NF3 and forms up to six ionic products, namely (in order of decreasing efficiency) NF2+, SiH2F+, SiHF2+, SiF+, SiHF+, and NHF+. The GeH3+ cation is instead totally unreactive toward NF3. The different reactivity of XH3+ (X = C, Si, Ge) toward NF3 has been rationalized by ab initio calculations performed at the MP2 and coupled cluster level of theory. In the reaction of both CH3+ and SiH3+, the kinetically relevant intermediate is the fluorine‐coordinated isomer H3X‐F‐NF2+ (X = C, Si). This species forms from the exoergic attack of XH3+ to one of the F atoms of NF3 and undergoes dissociation and isomerization processes which eventually result in the experimentally observed products. The nitrogen‐coordinated isomers H3X‐NF3+ (X = C, Si) were located as minimum‐energy structures but do not play an active role in the reaction mechanism. The inertness of GeH3+ toward NF3 is also explained by the endoergic character of the dissociation processes involving the H3Ge‐F‐NF2+ isomer. Copyright © 2009 John Wiley & Sons, Ltd.
γδ T cells: The overlooked T‐cell subset in demyelinating disease
Authors: Wohler Jillian E. , Smith Sherry S. , Barnum Scott R. 
Published: July 2009

Abstractγδ T cells represent a small subpopulation of T cells expressing a restricted repertoire of T‐cell receptors and, unlike αβ T cells, function more as cells of the innate immune system. These cells are found in skin and mucosal sites as well as secondary lymphoid tissues and frequently act as first line of defense sentinels. γδ T cells have been implicated in the pathogenesis of demyelinating disease, although little was known regarding their trafficking and effector functions. In this Mini‐Review, we highlight recent studies demonstrating that γδ T cells migrate rapidly to the CNS during experimental autoimmune encephalomyelitis (EAE), the animal model for multiple sclerosis. γδ T‐cell trafficking to the CNS is independent of β2‐integrins and occurs well before onset of clinical signs of disease, peaking early during the acute phase of disease. γδ T‐cell‐mediated production of inflammatory cytokines, including interferon‐γ and tumor necrosis factor‐α, appears critical for EAE development, suggesting that these cells may set the stage for activation of other subsets of infiltrating effector cells. These data suggest that γδ T cells or subsets of γδ T cells may represent a new therapeutic target in demeylinating disease. © 2009 Wiley‐Liss, Inc.
Cholinesterase activity in brain of senescence‐accelerated‐resistant mouse SAMR1 and its variation in brain of senescence‐accelerated‐prone mouse SAMP8
Authors: Fernández‐Gómez Francisco José , Muñoz‐Delgado Encarnación , Montenegro María Fernanda , Campoy Francisco J. , Vidal Cecilio J. , Jordán Joaquín 
Published: July 2009

AbstractThe early‐onset, irreversible, severe deficits of learning and memory in the senescence‐accelerated mouse (SAM)‐prone/8 (SAMP8) support its use as an animal model for human dementias of early onset. Possible implication of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) in cognitive dysfunction of SAMP8 mice was studied by comparing cholinesterase (ChE) expression in brains of SAMP8 mice and of their normal control, SAM‐resistant/1 (SAMR1) mice. The level of ChE mRNAs was the same in SAMP8 and SAMR1 brains, which agreed with their equal AChE activity (3.09 ± 1.45 vs. 3.07 ± 1.44 μmol·hr−1·mg protein−1, U/mg), but not with a doubled BuChE activity in SAMP8 brain (0.14 ± 0.05 vs. 0.07 ± 0.02 U/mg; P < 0.01). This great increase in neural BuChE activity may contribute to cognitive deficit of SAMP8 mice. Hydrophilic (G, 8%) and amphiphilic (G, 74%) AChE tetramers, besides dimers and monomers (G + G, 18%), were identified in SAMR1 brains. They also contained G BuChE forms (18%) as well as G (53%) and G + G (29%) species. Although SAMP8 brain displayed proportions of AChE and BuChE forms that were similar to those of SAMR1 brain, phenyl‐agarose chromatography with detergent‐free extracts showed a rise in the proportion of secretory G BuChE from 35% in SAMR1 to 44% in SAMP8 brain. The strong immunolabelling of glial fibrillary acidic protein (GFAP), a marker of reactive gliosis, in SAMP8 brain and the consideration of BuChE as a marker of glial cells suggest a relationship between phenotypic changes in neuroglial cells and the excess of BuChE activity in SAMP8 brain. © 2009 Wiley‐Liss, Inc.
Effort Games and the Price of Myopia
Authors: Bachrach Yoram , Zuckerman Michael , Rosenschein Jeffrey S. 
Published: July 2009

AbstractWe consider Effort Games, a game‐theoretic model of cooperation in open environments, which is a variant of the principal‐agent problem from economic theory. In our multiagent domain, a common project depends on various tasks; carrying out certain subsets of the tasks completes the project successfully, while carrying out other subsets does not. The probability of carrying out a task is higher when the agent in charge of it exerts effort, at a certain cost for that agent. A central authority, called the principal, attempts to incentivize agents to exert effort, but can only reward agents based on the success of the entire project.We model this domain as a normal form game, where the payoffs for each strategy profile are defined based on the different probabilities of carrying out each task and on the boolean function that defines which task subsets complete the project, and which do not. We view this boolean function as a simple coalitional game, and call this game the underlying coalitional game. We suggest the Price of Myopia (PoM) as a measure of the influence the model of rationality has on the minimal payments the principal has to make in order to motivate the agents in such a domain to exert effort.We consider the computational complexity of testing whether exerting effort is a dominant strategy for an agent, and of finding a reward strategy for this domain, using either a dominant strategy equilibrium or using iterated elimination of dominated strategies. We show these problems are generally #P‐hard, and that they are at least as computationally hard as calculating the Banzhaf power index in the underlying coalitional game. We also show that in a certain restricted domain, where the underlying coalitional game is a weighted voting game with certain properties, it is possible to solve all of the above problems in polynomial time. We give bounds on PoM in weighted voting effort games, and provide simulation results regarding PoM in another restricted class of effort games, namely effort games played over Series‐Parallel Graphs (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)