bluuebunny/crossref_metadata_2025_split huggingface dataset:
IL-7-dependent STAT-5 activation and CD8+ T cell proliferation are impaired in HIV infection
Authors: Vranjkovic Agatha , Crawley Angela M , Patey Andrea , Angel Jonathan B 
Published: December 2010

ABSTRACTThis study tests the hypothesis that IL-7 signaling and activity of CD8+ T cells are impaired in HIV infection. IL-7 is necessary for optimal CTL activity and T cell survival and proliferation. Defects in IL-7R signaling may contribute to impaired activity of IL-7 observed in progressive HIV disease. A decreased proportion of CD8+ T cells expressing the IL-7Rα chain (CD127) in progressive HIV disease would be expected to affect IL-7 activity. Alternatively, disease-associated defects of remaining CD8+CD127+ T cells may influence IL-7 responsiveness. Therefore, the IL-7 responsiveness of CD8+CD127+ T cells from HIV– and untreated or treated HIV+ individuals was investigated. Blood was collected from HIV– and untreated or effectively treated HIV+ (&lt;50 viral copies/ml for &gt;1 year) individuals, and CD8+CD127+ T cells were isolated and cultured with IL-7. Indicators of IL-7 signaling (P-STAT5) and activity (Bcl-2 and proliferation) were evaluated by flow cytometry. Isolated CD8+CD127+ T cells from untreated HIV+ individuals expressed significantly less P-STAT5 in response to IL-7 compared with CD8+CD127+ T cells from HIV– individuals. In effectively treated HIV+ individuals, CD8+CD127+ T cells also expressed significantly lower levels of P-STAT5 compared with HIV– individuals. IL-7-dependent proliferation of CD8+CD127+ T cells from untreated HIV+ individuals was similarly impaired. In contrast, IL-7-induced Bcl-2 expression was not impaired in CD8+CD127+ T cells from HIV+ individuals. These data demonstrate that IL-7/IL-7R dysfunction in HIV infection may contribute to IL-7-specific signaling defects. Decreased, IL-7-dependent activation of STAT5 and impaired proliferation may negatively impact the maintenance of CD8+ T cell responsiveness in HIV infection.
The Frailty of the Ontic
Authors: Terada Rei 
Published: December 2010

“Working through” would seem to be the crux of psychoanalysis. It is the collective name for the processes by which, despite itself, resistance gives way. Cumulatively, moments of unknotted resistance account for larger psychic change where it has been stalled —for, by definition, where one needs to work through, an obstacle to change has already arisen. Clinical analysts call psychic change “action”—“action” is what one has to show for one's therapy. Freud's theory of working through thus promises to shed light on the question that U.S. literary critics and social theorists have been accustomed to think about using the concept of “agency.” Theory now has moved slightly beyond this concept; yet a penumbra of anxiety about agency colors the reception of contemporary theory. A more direct questioning, not of the state of theories of agency exactly, but of the role of their ghosts in current theoretical discourse, may therefore be helpful. I reflect on these diagonally, while suggesting their difference from the theory of action implied by working through.
The logic of working through melts into the theory of reality as such. Registrations of pieces of reality, so the logic goes, depend on a relaxation of resistance, which may be the result of working through: the loosening of resistance enables a new perspective, the recognition of new objects. On the other hand, such registrations may enable resistance to loosen—registering any piece of reality can change the dynamic of resistances across the psychic system and have effects outside the immediate occasion. Working through resistance merges on both ends with the ongoing registration of perceptions in the lifelong project of trying to perceive reality together with other people. Departing somewhat from Freud's use of the term registration, I use it to emphasize the place where working through meets the ordinary registration of perceptions in the construction of reality. The absence of a boundary between the theory of working through and the theory of reality holds a possibility: that by reflecting on the banal registration of perceptions we can better understand action in several senses of the word.
Metabolic fuels: regulating fluxes to select mix
Authors: Weber Jean-Michel 
Published: December 2010

SummaryAnimals must regulate the fluxes of multiple fuels to support changing metabolic rates that result from variation in physiological circumstances. The aim of fuel selection strategies is to exploit the advantages of individual substrates while minimizing the impact of disadvantages. All exercising mammals share a general pattern of fuel selection: at the same they oxidize the same ratio of lipids to carbohydrates. However, highly aerobic species rely more on intramuscular fuels because energy supply from the circulation is constrained by trans-sarcolemmal transfer. Fuel selection is performed by recruiting different muscles, different fibers within the same muscles or different pathways within the same fibers. Electromyographic analyses show that shivering humans can modulate carbohydrate oxidation either through the selective recruitment of type II fibers within the same muscles or by regulating pathway recruitment within type I fibers. The selection patterns of shivering and exercise are different: at the same , a muscle producing only heat (shivering) or significant movement (exercise) strikes a different balance between lipid and carbohydrate oxidation. Long-distance migrants provide an excellent model to characterize how to increase maximal substrate fluxes. High lipid fluxes are achieved through the coordinated upregulation of mobilization, transport and oxidation by activating enzymes, lipid-solubilizing proteins and membrane transporters. These endurance athletes support record lipolytic rates in adipocytes, use lipoprotein shuttles to accelerate transport and show increased capacity for lipid oxidation in muscle mitochondria. Some migrant birds use dietary omega-3 fatty acids as performance-enhancing agents to boost their ability to process lipids. These dietary fatty acids become incorporated in membrane phospholipids and bind to peroxisome proliferator-activated receptors to activate membrane proteins and modify gene expression.
Energetic cost of communication
Authors: Stoddard Philip K. , Salazar Vielka L. 
Published: December 2010

SummaryCommunication signals may be energetically expensive or inexpensive to produce, depending on the function of the signal and the competitive nature of the communication system. Males of sexually selected species may produce high-energy advertisement signals, both to enhance detectability and to signal their size and body condition. Accordingly, the proportion of the energy budget allocated to signal production ranges from almost nothing for many signals to somewhere in excess of 50% for acoustic signals in short-lived sexually selected species. Recent data from gymnotiform electric fish reveal mechanisms that regulate energy allocated to sexual advertisement signals through dynamical remodeling of the excitable membranes in the electric organ. Further, males of the short-lived sexually selected species, Brachyhypopomus gauderio, trade off among different metabolic compartments, allocating energy to signal production while reducing energy used in other metabolic functions. Female B. gauderio, by contrast, do not trade off energy between signaling and other functions. To fuel energetically expensive signal production, we expect a continuum of strategies to be adopted by animals of different life history strategies. Future studies should explore the relation between life history and energy allocation trade-offs.
The physiological regulation of glucose flux into musclein vivo
Authors: Wasserman David H. , Kang Li , Ayala Julio E. , Fueger Patrick T. , Lee-Young Robert S. 
Published: December 2010

SummarySkeletal muscle glucose uptake increases dramatically in response to physical exercise. Moreover, skeletal muscle comprises the vast majority of insulin-sensitive tissue and is a site of dysregulation in the insulin-resistant state. The biochemical and histological composition of the muscle is well defined in a variety of species. However, the functional consequences of muscle biochemical and histological adaptations to physiological and pathophysiological conditions are not well understood. The physiological regulation of muscle glucose uptake is complex. Sites involved in the regulation of muscle glucose uptake are defined by a three-step process consisting of: (1) delivery of glucose to muscle, (2) transport of glucose into the muscle by GLUT4 and (3) phosphorylation of glucose within the muscle by a hexokinase (HK). Muscle blood flow, capillary recruitment and extracellular matrix characteristics determine glucose movement from the blood to the interstitium. Plasma membrane GLUT4 content determines glucose transport into the cell. Muscle HK activity, cellular HK compartmentalization and the concentration of the HK inhibitor glucose 6-phosphate determine the capacity to phosphorylate glucose. Phosphorylation of glucose is irreversible in muscle; therefore, with this reaction, glucose is trapped and the uptake process is complete. Emphasis has been placed on the role of the glucose transport step for glucose influx into muscle with the past assertion that membrane transport is rate limiting. More recent research definitively shows that the distributed control paradigm more accurately defines the regulation of muscle glucose uptake as each of the three steps that define this process are important sites of flux control.
Muscles and their myokines
Authors: Pedersen Bente Klarlund 
Published: December 2010

SummaryIn the past, the role of physical activity as a life-style modulating factor has been considered as that of a tool to balance energy intake. Although it is important to avoid obesity, physical inactivity should be discussed in a much broader context. There is accumulating epidemiological evidence that a physically active life plays an independent role in the protection against type 2 diabetes, cardiovascular diseases, cancer, dementia and even depression. For most of the last century, researchers sought a link between muscle contraction and humoral changes in the form of an ‘exercise factor’, which could be released from skeletal muscle during contraction and mediate some of the exercise-induced metabolic changes in other organs such as the liver and the adipose tissue. We have suggested that cytokines or other peptides that are produced, expressed and released by muscle fibres and exert autocrine, paracrine or endocrine effects should be classified as ‘myokines’. Given that skeletal muscle is the largest organ in the human body, our discovery that contracting skeletal muscle secretes proteins sets a novel paradigm: skeletal muscle is an endocrine organ producing and releasing myokines, which work in a hormone-like fashion, exerting specific endocrine effects on other organs. Other myokines work via paracrine mechanisms, exerting local effects on signalling pathways involved in muscle metabolism. It has been suggested that myokines may contribute to exercise-induced protection against several chronic diseases.
Limits to sustained energy intake. XIII. Recent progress and future perspectives
Authors: Speakman John R. , Król Elżbieta 
Published: December 2010

SummarySeveral theories have been proposed to explain limits on the maximum rate at which animals can ingest and expend energy. These limits are likely to be intrinsic to the animal, and potentially include the capacity of the alimentary tract to assimilate energy – the ‘central limitation’ hypothesis. Experimental evidence from lactating mice exposed to different ambient temperatures allows us to reject this and similar ideas. Two alternative ideas have been proposed. The ‘peripheral limitation’ hypothesis suggests that the maximal sustained energy intake reflects the summed demands of individual tissues, which have their own intrinsic limitations on capacity. In contrast, the ‘heat dissipation limit’ (HDL) theory suggests that animals are constrained by the maximal capacity to dissipate body heat. Abundant evidence in domesticated livestock supports the HDL theory, but data from smaller mammals are less conclusive. Here, we develop a novel framework showing how the HDL and peripheral limitations are likely to be important in all animals, but to different extents. The HDL theory makes a number of predictions – in particular that there is no fixed limit on sustained energy expenditure as a multiple of basal metabolic rate, but rather that the maximum sustained scope is positively correlated with the capacity to dissipate heat.
Critical oxygen levels and metabolic suppression in oceanic oxygen minimum zones
Authors: Seibel Brad A. 
Published: December 2010

SummaryThe survival of oceanic organisms in oxygen minimum zones (OMZs) depends on their total oxygen demand and the capacities for oxygen extraction and transport, anaerobic ATP production and metabolic suppression. Anaerobic metabolism and metabolic suppression are required for daytime forays into the most extreme OMZs. Critical oxygen partial pressures are, within a range, evolved to match the minimum oxygen level to which a species is exposed. This fact demands that low oxygen habitats be defined by the biological response to low oxygen rather than by some arbitrary oxygen concentration. A broad comparative analysis of oxygen tolerance facilitates the identification of two oxygen thresholds that may prove useful for policy makers as OMZs expand due to climate change. Between these thresholds, specific physiological adaptations to low oxygen are required of virtually all species. The lower threshold represents a limit to evolved oxygen extraction capacity. Climate change that pushes oxygen concentrations below the lower threshold (∼0.8 kPa) will certainly result in a transition from an ecosystem dominated by a diverse midwater fauna to one dominated by diel migrant biota that must return to surface waters at night. Animal physiology and, in particular, the response of animals to expanding hypoxia, is a critical, but understudied, component of biogeochemical cycles and oceanic ecology. Here, I discuss the definition of hypoxia and critical oxygen levels, review adaptations of animals to OMZs and discuss the capacity for, and prevalence of, metabolic suppression as a response to temporary residence in OMZs and the possible consequences of climate change on OMZ ecology.
A New Type of Cesium-ion-conducting Solid
Authors: Tamura Shinji , Nishikawa Taku , Imanaka Nobuhito 
Published: December 2010

Abstract
High Cs+ ion conductivity was successfully realized in solids at temperatures below 250 °C by doping Cs–bis(trifluoromethanesulfonyl) amide (CsTFSA) into cubic rare earth oxides of R2O3. Among the (1 − x)R2O3–xCsTFSA solids prepared, a 0.75Gd2O3–0.25CsTFSA solid showed the highest Cs+ ion conductivity of 3.4 × 10−2 S cm−1 at 250 °C, which is the highest value yet reported for a solid Cs+ ion conductor.
Central Nervous System Toxicity Associated with Ertapenem Use
Authors: Duquaine Susan , Kitchell Ellen , Tate Temeka , Tannen Richard C , Wickremasinghe Itala Manosha 
Published: December 2010

Objective To report stroke-like symptoms and unusual central nervous system adverse effects in 2 elderly patients receiving ertapenem. Case Summary: TWO patients ≥70 years of age experienced unusual mental status changes while receiving ertapenem. Patient 1 developed garbled speech and miosis 1 week after starting appropriately dosed ertapenem (1 g/day) for sacral osteomyelitis. Symptoms resolved upon ertapenem discontinuation but recurred upon rechallenge. Patient 2. a cachectic male with acute renal insufficiency, became delirious and progressively obtunded 5 days after starting ertapenem 1 g/day. Nine days after initiation of therapy, he required intubation and mechanical ventilation; ertapenem was discontinued at that time. Within 2 days of ertapenem discontinuation, his mental state cleared and the ventilator was removed. Discussion: Carbapenems, including ertapenem, have been implicated in causing central nervous system toxicity, including hallucinations and seizures. However, published reports of other, nonseizure-related central nervous system events are limited. Considerable resources were expended on extensive medical interventions before ertapenem was identified as a potential cause of the delirium in our patients. When applied to our patients, the Naranjo probability scale indicated a highly probable relationship for patient 1 and a probable relationship for patient 2 between the adverse effects and ertapenem use. Conclusions: Clinicians should be cognizant of ertapenem's potential to induce profound changes in mental status that may mimic other conditions in elderly patients.
Robust stability of positive continuous-time linear systems with delays
Authors: Busłowicz Mikołaj 
Published: December 2010

Robust stability of positive continuous-time linear systems with delaysThe paper is devoted to the problem of robust stability of positive continuous-time linear systems with delays with structured perturbations of state matrices. Simple necessary and sufficient conditions for robust stability in the general case and in the case of systems with a linear uncertainty structure in two sub-cases: (i) a unity rank uncertainty structure and (ii) nonnegative perturbation matrices are established. The problems are illustrated with numerical examples.
Derivative-free nonlinear optimization filter simplex
Authors: Correia Aldina , Matias João , Mestre Pedro , Serodio Carlos 
Published: December 2010

Derivative-free nonlinear optimization filter simplexThe filter method is a technique for solving nonlinear programming problems. The filter algorithm has two phases in each iteration. The first one reduces a measure of infeasibility, while in the second the objective function value is reduced. In real optimization problems, usually the objective function is not differentiable or its derivatives are unknown. In these cases it becomes essential to use optimization methods where the calculation of the derivatives or the verification of their existence is not necessary: direct search methods or derivative-free methods are examples of such techniques. In this work we present a new direct search method, based on simplex methods, for general constrained optimization that combines the features of simplex and filter methods. This method neither computes nor approximates derivatives, penalty constants or Lagrange multipliers.
Approach to the design of robust networked control systems
Authors: Morawski Michał , Zajączkowski Antoni 
Published: December 2010

Approach to the design of robust networked control systemsThe paper describes the application of the traffic engineering framework together with application layer procedures as mechanisms for the reduction of network latency lags. These mechanisms allow using standard and inexpensive hardware and software technologies typically applied for office networking as a means of realising networked control systems (NCSs) with high dynamic control plants, where a high dynamic control plant is the one that requires the sampling period several times shorter than communication lags induced by a network. The general discussion is illustrated by experimental results obtained in a laboratory NCS with the magnetic levitation system (MLS), which is an example of a structurally unstable plant of high dynamics.
Integrated region-based segmentation using color components and texture features with prior shape knowledge
Authors: Emambakhsh Mehryar , Ebrahimnezhad Hossein , Sedaaghi Mohammad 
Published: December 2010

Integrated region-based segmentation using color components and texture features with prior shape knowledgeSegmentation is the art of partitioning an image into different regions where each one has some degree of uniformity in its feature space. A number of methods have been proposed and blind segmentation is one of them. It uses intrinsic image features, such as pixel intensity, color components and texture. However, some virtues, like poor contrast, noise and occlusion, can weaken the procedure. To overcome them, prior knowledge of the object of interest has to be incorporated in a top-down procedure for segmentation. Consequently, in this work, a novel integrated algorithm is proposed combining bottom-up (blind) and top-down (including shape prior) techniques. First, a color space transformation is performed. Then, an energy function (based on nonlinear diffusion of color components and directional derivatives) is defined. Next, signeddistance functions are generated from different shapes of the object of interest. Finally, a variational framework (based on the level set) is employed to minimize the energy function. The experimental results demonstrate a good performance of the proposed method compared with others and show its robustness in the presence of noise and occlusion. The proposed algorithm is applicable in outdoor and medical image segmentation and also in optical character recognition (OCR).
Control flow graphs and code coverage
Authors: Gold Robert 
Published: December 2010

Control flow graphs and code coverageThe control flow of programs can be represented by directed graphs. In this paper we provide a uniform and detailed formal basis for control flow graphs combining known definitions and results with new aspects. Two graph reductions are defined using only syntactical information about the graphs, but no semantical information about the represented programs. We prove some properties of reduced graphs and also about the paths in reduced graphs. Based on graphs, we define statement coverage and branch coverage such that coverage notions correspond to node coverage, and edge coverage, respectively.
Markov chain model of phytoplankton dynamics
Authors: Wieczorek Radosław 
Published: December 2010

Markov chain model of phytoplankton dynamicsA discrete-time stochastic spatial model of plankton dynamics is given. We focus on aggregative behaviour of plankton cells. Our aim is to show the convergence of a microscopic, stochastic model to a macroscopic one, given by an evolution equation. Some numerical simulations are also presented.
Planning identification experiments for cell signaling pathways: An NFκB case study
Authors: Fujarewicz Krzysztof 
Published: December 2010

Planning identification experiments for cell signaling pathways: An NFκB case studyMathematical modeling of cell signaling pathways has become a very important and challenging problem in recent years. The importance comes from possible applications of obtained models. It may help us to understand phenomena appearing in single cells and cell populations on a molecular level. Furthermore, it may help us with the discovery of new drug therapies. Mathematical models of cell signaling pathways take different forms. The most popular way of mathematical modeling is to use a set of nonlinear ordinary differential equations (ODEs). It is very difficult to obtain a proper model. There are many hypotheses about the structure of the model (sets of variables and phenomena) that should be verified. The next step, fitting the parameters of the model, is also very complicated because of the nature of measurements. The blotting technique usually gives only semi-quantitative observations, which are very noisy and collected only at a limited number of time moments. The accuracy of parameter estimation may be significantly improved by a proper experiment design. Recently, we have proposed a gradient-based algorithm for the optimization of a sampling schedule. In this paper we use the algorithm in order to optimize a sampling schedule for the identification of the mathematical model of the NFκB regulatory module, known from the literature. We propose a two-stage optimization approach: a gradient-based procedure to find all stationary points and then pair-wise replacement for finding optimal numbers of replicates of measurements. Convergence properties of the presented algorithm are examined.