bluuebunny/crossref_metadata_2025 huggingface dataset:
Risperidone Enhances the Vulnerability to Stroke in Hypertensive Rats
Authors: Song Shu‐Wei , Sun Yang , Su Bei‐Lin , Liu Chong , Yang Chu , Godfraind Theophile , Su Ding‐Feng
Published: April 2012

Background: Stroke is the second most common cause of death and a major cause of disability worldwide. Risperidone is an atypical antipsychotic drug that may increase the risk of stroke. The present work examined whether risperidone enhances the vulnerability to stroke in hypertensive rats and the potential mechanisms underlying such action. Methods: Experiment 1: Wistar‐Kyoto (WKY) rats, spontaneously hypertensive rats (SHRs) and stroke‐prone SHRs (SHR‐SPs) were treated with risperidone (0.8 and 2.4 mg/kg/d) or vehicle for 30 consecutive days. Tissue damage in response to middle cerebral artery occlusion (MCAO) was measured microscopically. The activity of superoxide dismutase, glutathione peroxidase, the levels of malondialdehyde were also determined. Experiment 2: Survival data were recorded in SHR‐SPs that received daily risperidone perpetually. Experiment 3: Effect of risperidone on interleukin‐6 and tumor necrosis factor‐α was examined in quiescent or LPS‐activated cortical microglias from WKY rats. Experiment 4: Potential damage of risperidone exposure to neurons was examined in primary neuronal culture obtained from WKY rats, SHRs, and SHR‐SPs. Results: Risperidone increased infarct areas upon MCAO in SHR‐SPs and SHRs, but not in WKY rats. Survival time in SHR‐SPs was shortened by risperidone. Apoptosis was augmented by risperidone through enhanced Bax. Risperidone also increased endothelial injury. Conclusions: Risperidone enhances the vulnerability to stroke in hypertensive rats through increasing neuronal apoptosis and endothelial injury.
Payer types associated with antipsychotic polypharmacy in an ambulatory care setting
Authors: Williams Enifome O. , Stock Eileen M. , Zeber John E. , Copeland Laurel A. , Palumbo Francis B. , Stuart Mary , Miller Nancy A.
Published: April 2012

Objectives

Antipsychotic polypharmacy is increasingly prescribed despite little documented evidence of a therapeutic benefit. There is also a limited understanding of the role that health insurance plays on the prevalence of antipsychotic polypharmacy. This study was undertaken to investigate the relationship between antipsychotic polypharmacy and individuals' intended source of payment in a US national sample of ambulatory care patients.

Methods

The study combined 2002, 2003 and 2004 data from the National Ambulatory Medical Care Survey (NAMCS) among adults seeking outpatient-based physician medical care services in the USA. We investigated characteristic differences among patients who were prescribed multiple antipsychotics versus individuals receiving only a single antipsychotic medication. Multivariable logistic regression examined the association between antipsychotic polypharmacy and patients' primary payment type classified as private insurance, Medicaid, Medicare or other (primarily out-of-pocket) payment type.

Key findings

Use of more than one antipsychotic agent was recorded in 68 of 830 (8.2%) outpatient physician visits in the 3-year period 2002–2004. Among the payer types studied, Medicaid payment status was correlated with increased risk of antipsychotic polypharmacy (odds ratio 2.7, 95% confidence interval 1.1–6.7).

Conclusions

Insurance status was associated with antipsychotic polypharmacy among non-institutionalized US residents prescribed antipsychotic medications. Patients reporting Medicaid as their primary payer were nearly three times as likely to be prescribed multiple antipsychotic drugs, potentially increasing their risk of adverse side effects as well as greater taxpayer burden. Future research should determine whether these trends continued after 2004 and to determine the costs of treating patients in the public sector with multiple antipsychotic drugs, a common scenario despite financial pressures and uncertain medical benefit.
Product Reuse in Innovative Industries
Authors: Galbreth Michael R. , Boyacı Tamer , Verter Vedat
Published: April 2012

Most models of product reuse do not consider the fact that firms might be required to innovate their products over time in order to continue to appeal to the tastes of customers. We consider how the rate of this required innovation, which might be fast or slow depending on the product, affects reuse decisions. We consider two types of reuse—remanufacturing to original specifications, and upgrading used items by replacing components that have experienced innovation since the item was originally produced. We find that optimal reuse decreases with the rate of innovation, implying that models that ignore innovation overestimate the optimal amount of reuse that a company should pursue. Furthermore, we show that reuse can be encouraged in two ways—the intuitive approach of increasing end‐of‐life costs, and the less intuitive approach of raising the cost to make items reusable. We also examine the environmental impact of reuse, measured in terms of virgin material usage, finding that reuse can actually increase total virgin material usage in some cases. In an extension, we show how the results and insights change when the rate of innovation is uncertain.
Coupling Ritz Method and Triangular Quadrature Rule for Moving Mass Problem
Authors: Eftekhari S. A. , Jafari A. A.
Published: April 2012

In this paper, a mixed method that combines the Ritz method and the triangular quadrature rule (TQR) is presented for solving time-dependent problems. In this study, the Ritz method is first used to discretize the spatial partial derivatives. The TQR is then employed to analogize the temporal derivatives. The resulting algebraic formulation is a triangular matrix equation, which reduces to the solution of a system of algebraic equations of the size of the problem for each time step. This requires less computational effort compared to the differential quadrature method (DQM) where a larger system of the size of the problem should be solved within each time element. The mixed formulation combines the simplicity of the Ritz method and accuracy and computational efficiency of the TQR. The stability property and computational efficiency of the scheme are discussed in detail. Numerical results show that the proposed mixed methodology can be used as an efficient tool for handling the time-dependent problems.
Improving Asia-Pacific Science Collaboration
Authors: Toope Stephen J. , Tan Chorh Chuan , Fedoroff Nina V.
Published: April 2012

Recommendations affecting researchers, curricula, institutions, and tenure in the Asia-Pacific could increase innovation.
Reading Pliocene Bones
Authors: Njau Jackson
Published: April 2012

Standardized criteria will help to reliably distinguish marks made by hominid tools from feeding traces of other animals.
Copper Systematics in Arc Magmas and Implications for Crust-Mantle Differentiation
Authors: Lee Cin-Ty A. , Luffi Peter , Chin Emily J. , Bouchet Romain , Dasgupta Rajdeep , Morton Douglas M. , Le Roux Veronique , Yin Qing-zhu , Jin Daphne
Published: April 2012

Copper-Bottomed Crust

The formation of volcanic arc chains near subduction zones brings large amounts of magma from the upper mantle to the crust, contributing to the formation of island chains in the ocean and adding material to continents. Over time, arc magmas also contribute indirectly to the composition of the oceans and atmosphere through outgassing and weathering of volcanic minerals; however, it is unclear what determines the oxidized nature of arc magmas themselves.

Lee
et al.

(p.
64
) measured Cu contents in a range of arc-derived volcanic rocks as a proxy for arc magma redox states. An overall depletion of Cu, which is sensitive to reduced sulfur contents, in global continental crust suggests that there is a hidden reservoir of copper-rich sulfides deep in Earth's interior.
Location Matters
Great American City
Chicago and the Enduring Neighborhood Effect

by Robert J. Sampson

University of Chicago Press, Chicago, 2012. 552 pp. $27.50, £18. ISBN 9780226734569.
Authors: Massey Douglas S.
Published: April 2012

Synthesizing more than a decade of empirical research in Chicago, Sampson argues that neighborhoods strongly influence a wide range of social phenomena (including crime, health, civic engagement, altruism, and birthrates).
Strain-Specific Neutralizing Antibody Responses against Human Cytomegalovirus Envelope Glycoprotein N
Authors: Pati Sunil K. , Novak Zdenek , Purser Misty , Arora Nitin , Mach Michael , Britt William J. , Boppana Suresh B.
Published: April 2012

The human cytomegalovirus (HCMV) gM-gN complex is a major target of virus-neutralizing activity, and gN subtypes induce strain-specific antibodies. However, the biological significance of HCMV gN polymorphisms is not known. Neutralizing antibody responses against HCMV gN recombinant viruses were investigated at study entry in 80 healthy HCMV-seropositive women who were monitored for the appearance of new antibody specificities against linear strain-specific epitopes on glycoproteins gH and gB as evidence of HCMV reinfection. Neutralizing activity against all four gN recombinant viruses was seen in 74% of subjects, and 61% of subjects had strain-specific responses. Significantly fewer women (9/39 subjects [23%]) with serological evidence of reinfection had strain-specific neutralizing responses than the women without reinfection (21/41 subjects [51%]). Women with antibodies against at least one of the four linear gB and gH antigens at study entry had higher neutralizing titers against gN-1 (
P
= 0.006) and gN-2 (
P
= 0.007). Neutralizing titers of ≥400 against gN-3 (
P
= 0.043) and gN-4 (
P
= 0.049) at study entry were associated with longer times to serological evidence of reinfection. The findings demonstrate that HCMV gN elicits strain-specific neutralizing antibody responses and that broader anti-gN neutralizing activity may provide some protection from reinfection with a different virus strain.
Rapid Detection of the Top Six Non-O157 Shiga Toxin-Producing Escherichia coli O Groups in Ground Beef by Flow Cytometry
Authors: Hegde Narasimha V. , Jayarao Bhushan M. , DebRoy Chitrita
Published: April 2012

Rapid, sensitive, and highly specific flow-cytometric assays were developed for the detection of the top six non-O157 Shiga toxin-producing
Escherichia coli
(STEC) O groups in ground beef. The analytical sensitivity of the assays was 2 × 10
3
target cells in a bacterial mixture of 10
5
CFU/ml, and the limit of detection in ground beef was 1 to 10 CFU following 8 h of enrichment. The assays may be utilized for rapid detection of STEC O groups in meat.
Checklists, safety, my culture and me
Authors: Raghunathan Karthik
Published: April 2012

The world is not flat. Hierarchy is a fact of life in society and in healthcare institutions. National, specialty-specific and institutional cultures may play an important role in shaping today's patient -safety climate. The influence of power distance on safety interventions is under-studied. Checklists may make power distance-hampered negotiations easier by providing a standardised aviation-like framework for communications and by democratising the environment. By using surveys and simulation, we might discover patterns of potentially hidden yet problematic interactions that might foster maintenance of the error swamp. We need to understand how people interact as members of a group as this is crucial for the development of generalisable safety interventions.
HOLOGRAPHIC GEOMETRIC ENTROPY AT FINITE TEMPERATURE FROM BLACK HOLES IN GLOBAL ANTI-DE SITTER SPACES
Authors: BAH IBRAHIMA , PANDO ZAYAS LEOPOLDO A. , TERRERO-ESCALANTE CÉSAR A.
Published: April 2012

Using a holographic proposal for the geometric entropy we study its behavior in the geometry of Schwarzschild black holes in global AdSp for p = 3, 4, 5. Holographically, the entropy is determined by a minimal surface. On the gravity side, due to the presence of a horizon on the background, generically there are two solutions to the surfaces determining the entanglement entropy. In the case of AdS3, the calculation reproduces precisely the geometric entropy of an interval of length l in a two-dimensional conformal field theory with periodic boundary conditions. We demonstrate that in the cases of AdS4 and AdS5 the sign of the difference of the geometric entropies changes, signaling a transition. Euclideanization implies that various embedding of the holographic surface are possible. We study some of them and find that the transitions are ubiquitous. In particular, our analysis renders a very intricate phase space, showing, for some ranges of the temperature, up to three branches. We observe a remarkable universality in the type of results we obtain from AdS4 and AdS5.
ACCELERATING PATHWISE GREEKS IN THE LIBOR MARKET MODEL
Authors: JOSHI MARK , WIGUNA ALEXANDER
Published: April 2012

In the framework of the displaced-diffusion LIBOR market model, we derive the pathwise adjoint method for the iterative predictor-corrector and one of the Glasserman–Zhao drift approximations in the spot measure. This allows us to compute fast deltas and vegas under these schemes. We compare the discretisation bias obtained when computing Greeks with these methods to those obtained under the log-Euler and predictor-corrector approximations by performing tests with interest rate caplets and cancellable receiver swaps. The two predictor-corrector type methods were the most accurate by far. In particular, we found the iterative predictor-corrector method to be more accurate and slightly faster than the predictor-corrector method, the Glasserman–Zhao method, used, to be relatively fast but highly inconsistent, and the log-Euler method to be reasonably accurate but only at low volatilities. Standard errors were not significantly different across all four discretisations.
AN EXPLICIT OPTION-BASED STRATEGY THAT OUTPERFORMS DOLLAR COST AVERAGING
Authors: VANDUFFEL STEVEN , AHCAN ALES , HENRARD LUC , MAJ MATEUSZ
Published: April 2012

Dollar cost averaging (DCA) is a widely employed investment strategy in financial markets. At the same time it is also well documented that such gradual policy is sub-optimal from the point of view of risk averse decision makers with a fixed investment horizon T > 0. However, an explicit strategy that would be preferred by all risk averse decision makers did not yet appear in the literature. In this paper, we give a novel proof for the suboptimality of DCA when (log) returns are governed by Lévy processes and we construct a dominating strategy explicitly. The optimal strategy we propose is static and consists in purchasing a suitable portfolio of path-independent options. Next, we discuss a market governed by a Brownian motion in more detail. We show that the dominating strategy amounts to setting up a portfolio of power options. We provide evidence that the relative performance of DCA becomes worse in volatile markets, but also give some motivation to support its use. We also analyse DCA in presence of a minimal guarantee, explore the continuous setting and discuss the (non) uniqueness of the dominating strategy.
LOCALLY RISK-NEUTRAL VALUATION OF OPTIONS IN GARCH MODELS BASED ON VARIANCE-GAMMA PROCESS
Authors: KAO LIE-JANE
Published: April 2012

This study develops a GARCH-type model, i.e., the variance-gamma GARCH (VG GARCH) model, based on the two major strands of option pricing literature. The first strand of the literature uses the variance-gamma process, a time-changed Brownian motion, to model the underlying asset price process such that the possible skewness and excess kurtosis on the distributions of asset returns are considered. The second strand of the literature considers the propagation of the previously arrived news by including the feedback and leverage effects on price movement volatility in a GARCH framework. The proposed VG GARCH model is shown to obey a locally risk-neutral valuation relationship (LRNVR) under the sufficient conditions postulated by Duan (1995). This new model provides a unified framework for estimating the historical and risk-neutral distributions, and thus facilitates option pricing calibration using historical underlying asset prices. An empirical study is performed comparing the proposed VG GARCH model with four competing pricing models: benchmark Black–Scholes, ad hoc Black–Scholes, normal NGARCH, and stochastic volatility VG. The performance of the VG GARCH model versus these four competing models is then demonstrated.
IS SUBDIFFUSIONAL TRANSPORT SLOWER THAN NORMAL?
Authors: GOYCHUK IGOR
Published: April 2012

We consider anomalous non-Markovian transport of Brownian particles in viscoelastic fluid-like media with very large but finite macroscopic viscosity under the influence of a constant force field F. The viscoelastic properties of the medium are characterized by a power-law viscoelastic memory kernel which ultra slow decays in time on the time scale of strong viscoelastic correlations τ. The subdiffusive transport regime emerges transiently for t < τ. However, the transport becomes asymptotically normal for t ≫ τ. It is shown that even though transiently the mean displacement and the variance both scale sublinearly, i.e., anomalously slow, in time, 〈δx(t)〉 ∝ Ftα, 〈δx2(t)〉 ∝ tα, 0 < α <1, the mean displacement at each instant of time is nevertheless always larger than one obtained for normal transport in a purely viscous medium with the same macroscopic viscosity obtained in the Markovian approximation. This can have profound implications for the subdiffusive transport in biological cells as the notion of "ultra-slowness" can be misleading in the context of anomalous diffusion-limited transport and reaction processes occurring on nano- and mesoscales.
BaTiO3THIN FILM BY CSD FROM MOLECULAR-DESIGNED PRECURSOR SOLUTION
Authors: NAGASAKA MASAOMI , IWASAKI DAI , SAKAMOTO NAONORI , WAKIYA NAOKI , SUZUKI HISAO
Published: April 2012

BaTiO3(BT) thin films were deposited by the cost effective method of a chemical solution deposition (CSD). 0.3 M BT precursor solution was prepared by the partial hydrolysis method. Partially hydrolyzed Ti -alkoxide and Ba precursor solution was reacted to prepare the highly polymerized BT precursor solution. BT precursor solution was spin-coated on a Pt/Ti/SiO2/Si substrate with (100)-oriented LaNiO3(LNO) thin film electrode. In addition, effect of the pre-annealing at 600°C in O2atmosphere was elucidated by measuring the electrical properties of the resulting BT thin films deposited by the different annealing process. As a result, molecular-design of the BT precursor and a LNO thin film electrode were effective to enhance the electrical properties of the resultant BT thin films, as well as 600°C pre-annealing.
Leptin-sensitive neurons in the arcuate nuclei contribute to endogenous feeding rhythms
Authors: Li Ai-Jun , Wiater Michael F. , Oostrom Marjolein T. , Smith Bethany R. , Wang Qing , Dinh Thu T. , Roberts Brandon L. , Jansen Heiko T. , Ritter Sue
Published: April 2012

Neural sites that interact with the suprachiasmatic nuclei (SCN) to generate rhythms of unrestricted feeding remain unknown. We used the targeted toxin, leptin conjugated to saporin (Lep-SAP), to examine the importance of leptin receptor-B (LepR-B)-expressing neurons in the arcuate nucleus (Arc) for generation of circadian feeding rhythms. Rats given Arc Lep-SAP injections were initially hyperphagic and rapidly became obese (the “dynamic phase” of weight gain). During this phase, Lep-SAP rats were arrhythmic under 12:12-h light-dark (LD) conditions, consuming 59% of their total daily intake during the daytime, compared with 36% in blank-SAP (B-SAP) controls. Lep-SAP rats were also arrhythmic in continuous dark (DD), while significant circadian feeding rhythms were detected in all B-SAP controls. Approximately 8 wk after injection, Lep-SAP rats remained obese but transitioned into a “static phase” of weight gain marked by attenuation of their hyperphagia and rate of weight gain. In this phase, Arc Lep-SAP rats exhibited circadian feeding rhythms under LD conditions, but were arrhythmic in continuous light (LL) and DD. Lep-SAP injections into the ventromedial hypothalamic nucleus did not cause hyperphagia, obesity, or arrhythmic feeding in either LD or DD. Electrolytic lesion of the SCN produced feeding arrhythmia in DD but not hyperphagia or obesity. Results suggest that both Arc Lep-SAP neurons and SCN are required for generation of feeding rhythms entrained to photic cues, while also revealing an essential role for the Arc in maintaining circadian rhythms of ad libitum feeding independent of light entrainment.
Effects of the antioxidant drug tempol on renal oxygenation in mice with reduced renal mass
Authors: Lai En Yin , Luo Zaiming , Onozato Maristela L. , Rudolph Earl H. , Solis Glenn , Jose Pedro A. , Wellstein Anton , Aslam Shakil , Quinn Mark T. , Griendling Kathy , Le Thu , Li Ping , Palm Fredrik , Welch William J. , Wilcox Christopher S.
Published: April 2012

We tested the hypothesis that reactive oxygen species (ROS) contributed to renal hypoxia in C57BL/6 mice with ⅚ surgical reduction of renal mass (RRM). ROS can activate the mitochondrial uncoupling protein 2 (UCP-2) and increase O2usage. However, UCP-2 can be inactivated by glutathionylation. Mice were fed normal (NS)- or high-salt (HS) diets, and HS mice received the antioxidant drug tempol or vehicle for 3 mo. Since salt intake did not affect the tubular Na+transport per O2consumed (TNa/QO2), further studies were confined to HS mice. RRM mice had increased excretion of 8-isoprostane F2αand H2O2, renal expression of UCP-2 and renal O2extraction, and reduced TNa/QO2(sham: 20 ± 2 vs. RRM: 10 ± 1 μmol/μmol; P < 0.05) and cortical Po2(sham: 43 ± 2, RRM: 29 ± 2 mmHg; P < 0.02). Tempol normalized all these parameters while further increasing compensatory renal growth and glomerular volume. RRM mice had preserved blood pressure, glomeruli, and patchy tubulointerstitial fibrosis. The patterns of protein expression in the renal cortex suggested that RRM kidneys had increased ROS from upregulated p22phox, NOX-2, and -4 and that ROS-dependent increases in UCP-2 led to hypoxia that activated transforming growth factor-β whereas erythroid-related factor 2 (Nrf-2), glutathione peroxidase-1, and glutathione- S-transferase mu-1 were upregulated independently of ROS. We conclude that RRM activated distinct processes: a ROS-dependent activation of UCP-2 leading to inefficient renal O2usage and cortical hypoxia that was offset by Nrf-2-dependent glutathionylation. Thus hypoxia in RRM may be the outcome of NADPH oxidase-initiated ROS generation, leading to mitochondrial uncoupling counteracted by defense pathways coordinated by Nrf-2.
Complement alternative pathway activation in the autologous phase of nephrotoxic serum nephritis
Authors: Thurman Joshua M. , Tchepeleva Svetlana N. , Haas Mark , Panzer Sarah , Boackle Susan A. , Glogowska Magdalena J. , Quigg Richard J. , Holers V. Michael
Published: April 2012

The complement cascade is an important part of the innate immune system, but pathological activation of this system causes tissue injury in several autoimmune and inflammatory diseases, including immune complex glomerulonephritis. We examined whether mice with targeted deletion of the gene for factor B ( fB−/− mice) and selective deficiency in the alternative pathway of complement are protected from injury in the nephrotoxic serum (NTS) nephritis model of antibody-mediated glomerulonephritis. When the acute affects of the anti-glomerular basement membrane antibody were assessed, fB−/− mice developed a degree of injury similar to wild-type controls. If the mice were presensitized with sheep IgG or if the mice were followed for 5 mo postinjection, however, the fB−/− mice developed milder injury than wild-type mice. The immune response of fB−/− mice exposed to sheep IgG was similar to that of wild-type mice, but the fB−/− mice had less glomerular C3 deposition and lower levels of albuminuria. These results demonstrate that fB−/− mice are not significantly protected from acute heterologous injury in NTS nephritis but are protected from autologous injury in response to a planted glomerular antigen. Thus, although the glomerulus is resistant to antibody-initiated, alternative pathway-mediated injury, inhibition of this complement pathway may be beneficial in chronic immune complex-mediated diseases.
Stimulus repetition affects both strength and synchrony of macaque inferior temporal cortical activity
Authors: Kaliukhovich Dzmitry A. , Vogels Rufin
Published: April 2012

Repetition of a visual stimulus reduces the firing rate of macaque inferior temporal (IT) neurons. The neural mechanisms underlying this adaptation or repetition suppression are still unclear. In particular, we do not know how the IT circuit is affected by stimulus repetition. To address this, we measured local field potentials (LFPs) and multiunit spiking activity (MUA) simultaneously at 16 sites with a laminar electrode in IT while repeating visual images. Stimulus exposures and interstimulus intervals were each 500 ms. The rhesus monkeys were performing a passive fixation task during the recordings. Induced LFP power decreased with repetition for spectral frequencies above 60 Hz but increased with repetition for lower frequencies, the latter because of a delayed decrease in power when repeating a stimulus. LFP-LFP and MUA-LFP coherences decreased with repetition for frequencies above 60 Hz. This repetition suppression of the MUA-LFP coherence was not due to differences in firing rate since it was present when spike counts were equated for the adapter and repeated stimuli. For frequencies between 15 and 40 Hz, the effect of repetition on synchronization depended on the electrode depth: For the putative superficial layers synchronization was enhanced with repetition, while the LFPs of the putative deep layers decreased their synchrony across layers. The between-site, trial-to-trial covariations in MUA (“noise correlations”) decreased with repetition, but this might have reflected repetition suppression of the firing rate. This work demonstrates that short-term stimulus repetition affects the synchronized activity, in addition to response strength, in IT cortex.
Neurons with inverted tuning during the delay periods of working memory tasks in the dorsal prefrontal and posterior parietal cortex
Authors: Zhou Xin , Katsuki Fumi , Qi Xue-Lian , Constantinidis Christos
Published: April 2012

The dorsolateral prefrontal and posterior parietal cortices are two interconnected brain areas that are coactivated in tasks involving functions such as spatial attention and working memory. The response properties of neurons in the two areas are in many respects indistinguishable, yet only prefrontal neurons are able to resist interference by distracting stimuli when subjects are required to remember an initial stimulus. Several mechanisms have been proposed that could account for this functional difference, including the existence of specialized interneuron types, specific to the prefrontal cortex. Although such neurons with inverted tuning during the delay period of a working memory task have been described in the prefrontal cortex, no comparative data exist from other cortical areas that would establish a unique prefrontal role. To test this hypothesis, we analyzed a large database of recordings obtained in the dorsolateral prefrontal and posterior parietal cortex of the same monkeys as they performed working memory tasks. We found that in the prefrontal cortex, neurons with inverted tuning were more numerous and manifested unique properties. Our results give credence to the idea that a division of labor exists between separate neuron types in the prefrontal cortex and that this represents a functional specialization that is not present in its cortical afferents.
Phytotoxicity: An Overview of the Physiological Responses of Plants Exposed to Fungicides
Authors: Dias Maria Celeste
Published: April 2012

In the last decades, the use of fungicides in agriculture for fungi diseases control has become crucial. Fungicide research has produced a diverse range of products with novel modes of action. However, the extensive use of these compounds in the agriculture system raises public concern because of the harmful potential of such substances in the environment and human health. Moreover, the phytotoxic effects of some fungicides are already recognized but little is known about the impact of these compounds on the photosynthetic apparatus. This paper presents a comprehensive overview of the literature considering different classes of fungicides and their effects on plant physiology, with particular emphasis on photosynthesis.
Cylindrical Bending of Deformable Textile Rectangular Patch Antennas
Authors: Boeykens Freek , Vallozzi Luigi , Rogier Hendrik
Published: April 2012

Textile patch antennas are well known as basic components for wearable systems that allow communication between a human body and the external world. Due to their flexibility, textile antennas are subjected to bending when worn, causing a variation in resonance frequency and radiation pattern with respect to the flat state in which their nominal design is performed. Hence, it is important for textile antenna engineers to be able to predict these performance parameters as a function of the bending radius. Therefore, we propose a comprehensive analytical model that extends the cylindrical cavity model for conformal rigid patch antennas by incorporating the effects of patch stretching and substrate compression. It allows to predict the resonance frequency and the radiation pattern as a function of the bending radius. Its validity has been verified experimentally. Unlike previous contributions, which concerned only qualitative studies by means of measurements and numerical full-wave simulations, the proposed model offers advantages in terms of physical insight, accuracy, speed, and cost.
Prediagnosis of Obstructive Sleep Apnea via Multiclass MTS
Authors: Su Chao-Ton , Chen Kun-Huang , Chen Li-Fei , Wang Pa-Chun , Hsiao Yu-Hsiang
Published: April 2012

Obstructive sleep apnea (OSA) has become an important public health concern. Polysomnography (PSG) is traditionally considered an established and effective diagnostic tool providing information on the severity of OSA and the degree of sleep fragmentation. However, the numerous steps in the PSG test to diagnose OSA are costly and time consuming. This study aimed to apply the multiclass Mahalanobis-Taguchi system (MMTS) based on anthropometric information and questionnaire data to predict OSA. Implementation results showed that MMTS had an accuracy of 84.38% on the OSA prediction and achieved better performance compared to other approaches such as logistic regression, neural networks, support vector machine, C4.5 decision tree, and rough set. Therefore, MMTS can assist doctors in prediagnosis of OSA before running the PSG test, thereby enabling the more effective use of medical resources.
A New Weighted Correlation Coefficient Method to Evaluate Reconstructed Brain Electrical Sources
Authors: Choi Jong-Ho , Kim Min-Hyuk , Feng Luan , Lee Chany , Jung Hyun-Kyo
Published: April 2012

Various inverse algorithms have been proposed to estimate brain electrical activities with magnetoencephalography (MEG) and electroencephalography (EEG). To validate and compare the performances of inverse algorithms, many researchers have used artificially constructed EEG and MEG datasets. When the artificial sources are reconstructed on the cortical surface, accuracy of the source estimates has been difficult to evaluate. In this paper, we suggest a new measure to evaluate the reconstructed EEG/MEG cortical sources more accurately. To validate the usefulness of the proposed method, comparison between conventional and proposed evaluation metrics was conducted using artificial cortical sources simulated under different noise conditions. The simulation results demonstrated that only the proposed method could reflect the source space geometry regardless of the number of source peaks.
About the Stabilization of a Nonlinear Perturbed Difference Equation
Authors: De la Sen M.
Published: April 2012

This paper investigates the local asymptotic stabilization of a very general class of instable autonomous nonlinear difference equations which are subject to perturbed dynamics which can have a different order than that of the nominal difference equation. In the general case, the controller consists of two combined parts, namely, the feedback nominal controller which stabilizes the nominal (i.e., perturbation‐free) difference equation plus an incremental controller which completes the stabilization in the presence of perturbed or unmodeled dynamics in the uncontrolled difference equation. A stabilization variant consists of using a single controller to stabilize both the nominal difference equation and also the perturbed one under a small‐type characterization of the perturbed dynamics. The study is based on Banach fixed point principle, and it is also valid with slight modification for the stabilization of unstable oscillatory solutions.
On the Variational Eigenvalues Which Are Not of Ljusternik‐Schnirelmann Type
Authors: Drábek Pavel
Published: April 2012

We discuss nonlinear homogeneous eigenvalue problems and the variational characterization of their eigenvalues. We focus on the Ljusternik‐Schnirelmann method, present one possible alternative to this method and compare it with the Courant‐Fischer minimax principle in the linear case. At the end we present a special nonlinear eigenvalue problem possessing an eigenvalue which allows the variational characterization but is not of Ljusternik‐Schnirelmann type.
Mean Square Consensus for Uncertain Multiagent Systems with Noises and Delays
Authors: Sun Yuangong
Published: April 2012

This paper investigates the consensus problem in mean square for uncertain multiagent systems with stochastic measurement noises and symmetric or asymmetric time‐varying delays. By combining the tools of stochastic analysis, algebraic graph theory, and matrix theory, we analyze the convergence of a class of distributed stochastic approximation type protocols with time‐varying consensus gains. Numerical examples are also given to illustrate the theoretical results.
Solid‐Phase Immunoassay of Polystyrene‐Encapsulated Semiconductor Coreshells for Cardiac Marker Detection
Authors: Kim Sanghee , Seo Jaetae , Ramdon Roopchan , Pyo Hyeon-Bong , Song Kyuho , Kang Byoung Hun
Published: April 2012

A solid‐phase immunoassay of polystyrene‐encapsulated semiconductor nanoparticles was demonstrated for cardiac troponin I (cTnI) detection. CdSe/ZnS coreshells were encapsulated with a carboxyl‐functionalized polystyrene nanoparticle to capture the target antibody through a covalent bonding and to eliminate the photoblinking and toxicity of semiconductor luminescent immunosensor. The polystyrene‐encapsulated CdSe/ZnS fluorophores on surface‐modified glass chip identified cTnI antigens at the level of ~ng/mL. It was an initial demonstration of diagnostic chip for monitoring a cardiovascular disease.
Anterior Mediastinal Mass in a Young Marijuana Smoker: A Rare Case of Small-Cell Lung Cancer
Authors: Kothadia Jiten P. , Chhabra Saurabh , Marcus Alan , May Michael , Saraiya Biren , Jabbour Salma K.
Published: April 2012

The use of cannabis is embedded within many societies, mostly used by the young and widely perceived to be safe. Increasing concern regarding the potential for cannabis to cause mental health effects has dominated cannabis research, and the potential adverse respiratory effects have received relatively little attention. We report a rare case of 22-year-old man who presented with bilateral neck lymphadenopathy, fatigue, and sore throat without significant medical or family history. The patient had smoked one marijuana joint three times a week for three years but no cigarettes. Chest CT demonstrated a large anterior mediastinal mass compressing the superior vena cava and mediastinal lymphadenopathy. A final diagnosis of small-cell lung cancer was reached. Although rare, a small-cell lung cancer in this patient should alert the physician that cannabis smoking may be a risk factor for lung cancer.
Neurocognitive and Social Cognitive Approaches for Improving Functional Outcome in Early Psychosis: Theoretical Considerations and Current State of Evidence
Authors: Bartholomeusz Cali F. , Allott Kelly
Published: April 2012

Improving functional outcome, in addition to alleviating psychotic symptoms, is now a major treatment objective in schizophrenia research. Given the large body of evidence suggesting pharmacological treatments generally have minimal effects on indices of functioning, research has turned to psychosocial rehabilitation programs. Among these, neurocognitive and social cognitive interventions are at the forefront of this field and are argued to target core deficits inherent to the schizophrenia illness. However, to date, research trials have primarily focused on chronic schizophrenia populations, neglecting the early psychosis groups who are often as severely impaired in social and occupational functioning. This theoretical paper will outline the rationale for investigating adjunctive cognitive-based interventions in the early phases of psychotic illness, critically examine the current approach strategies used in these interventions, and assess the evidence supporting certain training programs for improving functional outcome in early psychosis. Potential pathways for future research will be discussed.
An Adaptive Domain Partitioning Technique for Meshfree‐Type Methods
Authors: Shanazari Kamal
Published: April 2012

An overlapping domain partitioning based on adapting nodes is presented for the meshless‐type methods. The decomposition of the domain is carried out based on the distribution of the nodes produced rather than the geometry of the problem. A set of adaptive nodes is first generated using the dimension reduction and equidistributing along the coordinate directions with respect to arc‐length monitor. The domain is then partitioned in such a way that the same number of nodes are allocated to the subdomains. A radial basis function collocation method is applied to each subdomain followed by assembling the global solution from the subproblem′s solutions. A generalized thin plate spline with sufficient smoothness is used as a basis function in the collocation method. Some numerical results will be presented to show the performance of the proposed method.
Fixed and Best Proximity Points of Cyclic Jointly Accretive and Contractive Self‐Mappings
Authors: De la Sen M.
Published: April 2012

p(≥2)‐cyclic and contractive self‐mappings on a set of subsets of a metric space which are simultaneously accretive on the whole metric space are investigated. The joint fulfilment of the p‐cyclic contractiveness and accretive properties is formulated as well as potential relationships with cyclic self‐mappings in order to be Kannan self‐mappings. The existence and uniqueness of best proximity points and fixed points is also investigated as well as some related properties of composed self‐mappings from the union of any two adjacent subsets, belonging to the initial set of subsets, to themselves.
Role of NKT Cells in the Pathogenesis of NAFLD
Authors: Tajiri Kazuto , Shimizu Yukihiro
Published: April 2012

Nonalcoholic fatty liver disease (NAFLD) is the most frequent chronic liver disease and shows various inflammatory changes in the liver. Among those inflammatory cells, natural killer T (NKT) cells are found to have a critical role during the disease progression. NKT cells may have a protective role at the early stage with simple steatosis through modification of insulin resistance, whereas they act as a progression factor at the advanced stage with fibrosis. Those processes are thought to depend on interaction between NKT cells and CD1d molecule in the liver.
Class-Based Weighted Fair Queuing Scheduling on Dual-Priority Delta Networks
Authors: Vasiliadis D. C. , Rizos G. E. , Vassilakis C.
Published: April 2012

Contemporary networks accommodate handling of multiple priorities, aiming to provide suitable QoS levels to different traffic classes. In the presence of multiple priorities, a scheduling algorithm is employed to select each time the next packet to transmit over the data link. Class-based Weighted Fair Queuing (CBWFQ) scheduling and its variations is widely used as a scheduling technique, since it is easy to implement and prevents the low-priority queues from being completely neglected during periods of high-priority traffic. By using this scheduling, low-priority queues have the opportunity to transmit packets even though the high-priority queues are not empty. In this work, the modeling, analysis and performance evaluation of a single-buffered, dual-priority multistage interconnection network (MIN) operating under the CBWFQ scheduling policy is presented. Performance evaluation is conducted through simulation, and the performance measures obtained can be valuable assets for MIN designers, in order to minimize the overall deployment costs and delivering efficient systems.
The Sexual Behaviour of Chagas' Disease Vectors: Chemical Signals Mediating Communication between Male and Female Triatomine Bugs
Authors: Manrique Gabriel , Lorenzo Marcelo
Published: April 2012

Chemical communication mechanisms that mediate sexual behaviour in triatomine bugs are reviewed with regard to source, identity, and function of sex pheromones. Males attempt to copulate but may be rejected, depending on female age and nutritional status. Triatomine males locate partners through sex pheromones emitted by the metasternal glands (MGs) of females. These activate males, inducing them to leave their refuges and initiate flight. Wandering males display anemotactic orientation modulated by chemical signals emitted from female MGs. Analyses of the MG secretions of several species resulted in the identification of numerous ketones, acetals, and alcohols. Occlusion experiments showed that Brindley’s gland products were not required for mating. Metasternal gland volatiles are emitted by virgin male and female bugs, with detection over females occurring more consistently, especially during the early scotophase, suggesting female calling behaviour. Mating triatomine females have been reported to attract males that tend to copulate successively with them. Mating males prolong mating and postcopulatory mate guarding in the presence of other males. This is indicative of a polyandrous mating system in several triatomine species. Its potential advantages remain unknown, and comparative studies are required to increase our understanding of triatomine reproductive strategies.
Nonlinear Random Stability via Fixed‐Point Method
Authors: Cho Yeol Je , Kang Shin Min , Saadati Reza
Published: April 2012

We prove the generalized Hyers‐Ulam stability of the following additive‐quadratic‐cubic‐quartic functional equation f(x + 2y) + f(x − 2y) = 4f(x + y) + 4f(x − y) − 6f(x) + f(2y) + f(−2y) − 4f(y) − 4f(−y) in various complete random normed spaces.
Toward a Minimal Representation of Aerosols in Climate Models: Comparative Decomposition of Aerosol Direct, Semidirect, and Indirect Radiative Forcing
Authors: Ghan S. J. , Liu X. , Easter R. C. , Zaveri R. , Rasch P. J. , Yoon J.-H. , Eaton B.
Published: April 2012

The authors have decomposed the anthropogenic aerosol radiative forcing into direct contributions from each aerosol species to the planetary energy balance through absorption and scattering of solar radiation, indirect effects of anthropogenic aerosol on solar and infrared radiation through droplet and crystal nucleation on aerosol, and semidirect effects through the influence of solar absorption on the distribution of clouds. A three-mode representation of the aerosol in version 5.1 of the Community Atmosphere Model (CAM5.1) yields global annual mean radiative forcing estimates for each of these forcing mechanisms that are within 0.1 W m−2 of estimates using a more complex seven-mode representation that distinguishes between fresh and aged black carbon and primary organic matter. Simulating fresh black carbon particles separately from internally mixed accumulation mode particles is found to be important only near fossil fuel sources. In addition to the usual large indirect effect on solar radiation, this study finds an unexpectedly large positive longwave indirect effect (because of enhanced cirrus produced by homogenous nucleation of ice crystals on anthropogenic sulfate), small shortwave and longwave semidirect effects, and a small direct effect (because of cancelation and interactions of direct effects of black carbon and sulfate). Differences between the three-mode and seven-mode versions are significantly larger (up to 0.2 W m−2) when the hygroscopicity of primary organic matter is decreased from 0.1 to 0 and transfer of the primary carbonaceous aerosol to the accumulation mode in the seven-mode version requires more hygroscopic material coating the primary particles. Radiative forcing by cloudborne anthropogenic black carbon is only −0.07 W m−2.
The Temporal Autocorrelation Structure of Sea Surface Winds
Authors: Monahan Adam H.
Published: April 2012

The temporal autocorrelation structures of sea surface vector winds and wind speeds are considered. Analyses of scatterometer and reanalysis wind data demonstrate that the autocorrelation functions (acf) of surface zonal wind, meridional wind, and wind speed generally drop off more rapidly in the midlatitudes than in the low latitudes. Furthermore, the meridional wind component and wind speed generally decorrelate more rapidly than the zonal wind component. The anisotropy in vector wind decorrelation scales is demonstrated to be most pronounced in the storm tracks and near the equator, and to be a feature of winds throughout the depth of the troposphere. The extratropical anisotropy is interpreted in terms of an idealized kinematic eddy model as resulting from differences in the structure of wind anomalies in the directions along and across eddy paths. The tropical anisotropy is interpreted in terms of the kinematics of large-scale equatorial waves and small-scale convection. Modeling the vector wind fluctuations as Gaussian, an explicit expression for the wind speed acf is obtained. This model predicts that the wind speed acf should decay more rapidly than that of at least one component of the vector winds. Furthermore, the model predicts a strong dependence of the wind speed acf on the ratios of the means of vector wind components to their standard deviations. These model results are shown to be broadly consistent with the relationship between the acf of vector wind components and wind speed, despite the presence of non-Gaussian structure in the observed surface vector winds.
Assessing the Mediation of a Fuller Social Learning Model on Low Self-Control’s Influence on Software Piracy
Authors: Burruss George W. , Bossler Adam M. , Holt Thomas J.
Published: April 2012

Researchers have explored the empirical validity of linking key concepts from Gottfredson and Hirschi’s general theory of crime and Akers’ social learning theory. Much of this research, however, has neither included measures of differential reinforcement and imitation nor operationalized the social learning process as a second-order latent construct as supported by Akers and other scholars. Thus, in this study, the authors used structural equation modeling to examine both the direct effect of low self-control and its indirect effect via a fuller measure of the social learning process on software piracy to improve our understanding of this specific phenomenon and to also provide further insight on the empirical validity of linking concepts from these two theories. They found that the indirect effect of self-control via the social learning process on piracy was greater than its direct effect. In addition, as levels of low self-control increased, the probability of software piracy actually decreased when controlling for the social learning process.