Miracle-dz/UniFAR-FTUs huggingface dataset:
Antioxidant compounds and Ca2+ pathway blockers differentially protect against methylmercury and mercuric chloride neurotoxicity

The effects of the environmental contaminants methylmercury (MeHg) and inorganic mercury (HgCl2) on cell viability, intracellular calcium concentration ([Ca2+]i), and reactive oxygen species (ROS) generation were studied in rat cerebellar granule neuron cultures using fluorescent methods. MeHg exhibited an LC50 (2.47 μM) tenfold lower than that of HgCl2 (26.40 μM). To study the involvement of oxidative stress and Ca2+ homeostasis disruption in mercury‐induced cytotoxicity, we tested the neuroprotective effects of several agents that selectively interfere with these mechanisms. After a 24 hr exposure, the cytotoxic effect of both mercury compounds was reduced by thapsigargin, an inhibitor of endoplasmic reticulum Ca2+‐ATPase; the Ca2+ channel blocker flunarizine; and the Na+/Ca2+ exchanger blocker benzamil. All these compounds decreased the mercury‐mediated [Ca2+]i rise. These results indicate that Ca2+ influx through Ca2+ channels and the Na+/Ca2+ exchanger and Ca2+ mobilization from the endoplasmic reticulum are involved in mercury‐mediated cytotoxicity. The antioxidants probucol and propyl gallate reduced the HgCl2 toxicity. Probucol and vitamin E partially inhibited the MeHg toxicity after a 24 hr period, whereas propyl gallate completely prevented this effect. Probucol slightly reduced ROS generation in methylmercury‐exposed cultures and decreased mercury‐mediated rise of [Ca2+]i. Propyl gallate abolished ROS generation and partially inhibited the increase of [Ca2+]i induced by both mercury compounds. Propyl gallate also protected human cerebral cortical neuron cultures from the MeHg effect even after 72 hr of MeHg exposure, thus showing a long‐lasting effect. Our data suggest that disruption of redox equilibrium and Ca2+ homeostasis contribute equally to HgCl2‐mediated toxicity, whereas oxidative stress is the main cause of MeHg neurotoxicity. J. Neurosci. Res. 66:135–145, 2001. © 2001 Wiley‐Liss, Inc.
Multiple acoustic sources localization using distributed expectation-maximization algorithm

The challenge of localizing number of concurrent acoustic sources in reverberant enclosures is addressed in this paper. We formulate the localization task as a maximum likelihood (ML) parameter estimation problem, and develop a distributed expectation-maximization (DEM) procedure, based on the Incremental EM (IEM) framework. The algorithm enables localization of the speakers without a center point. Unlike direction search, localization is a distributed task in nature, since the sensors must be spatially deployed. Taking advantage of the distributed constellation of the sensors we propose a distributed algorithm that enables multiple processing nodes and considers communication constraints between them. The proposed DEM has surprising advantages over conventional expectation-maximization (EM) schemes. Firstly, it is less sensitive to initial conditions. Secondly, it converges much faster than the conventional EM. The proposed algorithm is tested by an extensive simulation study.
What Children Do on the Internet: Domains Visited and Their Relationship to Socio-Demographic Characteristics and Academic Performance

HomeNetToo is a longitudinal field study designed to examine the antecedents and consequences of home Internet use in low-income families. Participants included 140 children, mostly 13-year-old African American (83%) boys (58%), living in single-parent households (75%) where the median annual income was $15,000 (USD). This report focuses on children's Internet activities, socio-demographic characteristics related to their Internet activities, and the relationship between academic performance and Internet activities. Overall, findings indicate that low-income children initially use the Internet primarily for entertainment. As home Internet use loses its novelty children become more focused in their Internet activities, reducing the number of websites they visit and visiting more websites targeted to their specific interests. Pornography websites are popular initially, especially among boys, but their popularity decreases dramatically after 3 months. Age, race, and sex have little influence on which websites are most popular. Academic performance predicts subsequent Internet activities, and Internet activities predict subsequent academic performance. Directions for future research to identify mechanisms that mediate the relationship between Internet activities and academic performance and implications for the digital divide are discussed.
Depolarization affects the lateral microdomain structure of yeast plasma membrane

We report the transmembrane voltage‐induced lateral reorganization of highly‐ordered lipid microdomains in the plasma membrane of living Saccharomyces cerevisiae. Using trans‐parinaric acid (all‐trans‐9,11,13,15‐octadecatetraenoic acid) as a probe of lipid order and different methods of membrane depolarization, we found that depolarization always invokes a significant reduction in the amount of gel‐like microdomains in the membrane. Different depolarization mechanisms, including the application of ionophores, cell depolarization by an external electric field, depolarization by proton/hexose co‐transport facilitated by HUP1 protein and a reduction of membrane potential caused by compromised respiration efficiency, yielded the same results independently of the yeast strain used. The data suggest that the voltage‐induced reorganization of lateral membrane structure could play significant role in fast cellular response to acute stress conditions, as well as in other membrane microdomain‐related regulatory mechanisms.
The TIMPs tango with MMPs and more in the central nervous system

The matrix metalloproteinases (MMPs) are a family of zinc‐dependent extracellular proteases that have been implicated in CNS development and disease. Crucial homeostatic regulation of MMPs is mediated through the expression and actions of the tissue inhibitors of metalloproteinases (TIMPs). Although the TIMPs are recognized inhibitors of the MMPs, recent studies have revealed that these proteins also can exhibit biological activities that are distinct from their interactions with or inhibition of the MMPs. With our understanding of the roles of the TIMPs in the CNS continuously emerging, this review examines the current state of knowledge regarding the multifarious and novel functions of this family of proteins, with particular attention to their increasing potential in the development, plasticity, and pathology of the CNS. © 2003 Wiley‐Liss, Inc.
l'interaction Patient-Ventilateur: Approche technique d'une analyse biologique

par assistance respiratoire mecanique partielle. Nous avons essaye de preciser la description du systeme hybride {Patient, Ventilateur} afin de construire un outil clinique de surveillance de l'IPV. Dans un premier temps, nous avons propose d'aborder l'IPV comme la phenomenologie locale d'un reseau biologique communicant. L'IPV est alors la traduction de la communication etablie a travers l'appareil respiratoire entre un oscillateur biologique et un oscillateur mecanique. Cette approche biologique permet a la fois d'utiliser les resultats de la theorie de la communication pour elaborer un score de desynchronisation, et de construire l'outil necessaire pour calculer ce score en clinique. L'outil est un detecteur non-invasif de l'activite musculaire a partir de l'estimation de la pression musculaire par un modele de la mecanique du systeme ventilatoire dont le traitement de signal est suffisamment robuste pour permettre son automatisation. Nous avons ensuite valide ces constructions chez des patients sous assistance partielle. Le score de desynchronisation est specifiquement augmente par la combinaison d'alterations de la voie de communication ou de la generation de l'activite inspiratoire a transmettre. La quantification automatique de l'IPV par un score specifique de desynchronisation, reflet de l'alteration de la transmission de l'information entre le patient et son ventilateur, et par une detection de l'activite inspiratoire, reflet du message a transmettre, devrait permettre d'ameliorer l'analyse clinique du comportement des patients sous assistance partielle
Effects of native language on perceptual sensitivity to phonetic cues

The present study used electrophysiological and behavioral measures to investigate the perception of an English stop consonant contrast by native English listeners and by native Dutch listeners who were highly proficient in English. A /ba/-/pa/ continuum was created from a naturally produced /pa/ token by removing successive periods of aspiration, thus reducing the voice onset time. Although aspiration is a relevant cue for distinguishing voiced and unvoiced labial stop consonants (/b/ and /p/) in English, prevoicing is the primary cue used to distinguish between these categories in Dutch. In the electrophysiological experiment, participants listened to oddball sequences containing the standard /pa/ stimulus and one of three deviant stimuli while the mismatch-negativity response was measured. Participants then completed an identification task on the same stimuli. The results showed that native English participants were more sensitive to reductions in aspiration than native Dutch participants, as indicated by shifts in the category boundary, by differing within-group patterns of mismatch-negativity responses, and by larger mean evoked potential amplitudes in the native English group for two of the three deviant stimuli. This between-group difference in the sensorineural processing of aspiration cues indicates that native language experience alters the way in which the acoustic features of speech are processed in the auditory brain, even following extensive second-language training.
Degradation of Phthalic Acids and Benzoic Acid from Terephthalic Acid Wastewater by Advanced Oxidation Processes

Terephthalic acid (TPA) wastewater is traditionally being treated by biological method. This study investigates the degradation of three major toxic target organic species, namely terephthalic acid (TPA), isophthalic acid (IPA), benzoic acid (BA), present in the TPA wastewater, by several advanced oxidation processes. The performance of three main oxidation processes such as photofenton oxidation (UV-H2O2-Fe), photocatalytic ozonation (UV-O3-Fe) and photofenton ozonation (UV-O3-H2O2-Fe) were studied. Studies were conducted with and without dilution of TPA wastewater. Photofenton ozonation was found to be most efficient by achieving almost complete destruction of all the three target organics in less than 30 minutes of reaction. In combining several oxidation processes, a comparative study was also carried out between one step addition of oxidants and stepwise addition.
Unpublished research from a medical specialty meeting: why investigators fail to publish.

CONTEXT It is not known whether peer review of research abstracts submitted to scientific meetings influences subsequent attempts at publication. OBJECTIVE To determine why research submitted to a scientific meeting is not subsequently published. We hypothesized that authors of abstracts rejected by a meeting are less likely to pursue publication than those whose abstracts are accepted, regardless of research quality. DESIGN AND PARTICIPANTS Blinded review of abstracts submitted to a medical specialty meeting in 1991 and not published as full manuscripts within 5 years. In 1996, authors of 266 unpublished studies were asked to complete questionnaires. MAIN OUTCOME MEASURES Submission of a full manuscript to a journal between 1991 and 1996; failure to submit a manuscript to a journal because the investigator believed it would not be accepted for publication. RESULTS A total of 223 (84%) of the unpublished investigators returned the questionnaire. Only 44 (20%) had submitted manuscripts to a journal. Manuscript submission was not associated with abstract quality (odds ratio [OR], 1.16; 95% confidence interval [CI], 0.80-1.64), positive results (OR, 0.75; 95% CI, 0.31-1.57), or other study characteristics. Having an abstract accepted for presentation at the meeting weakly predicted submission of a manuscript to a journal (OR, 1.88; 95% CI, 0.84-4.10). Authors of accepted abstracts were significantly less likely to believe a journal would not publish their manuscript than were authors of rejected abstracts (OR, 0.23; 95% CI, 0.0001-0.61). CONCLUSIONS Study characteristics do not predict attempts to publish research submitted to a scientific meeting. Investigators whose research is rejected by a meeting are pessimistic about chances for publication and may make less effort to publish.
Patients' attitudes to medicines and adherence to maintenance treatment in inflammatory bowel disease

Background: Nonadherence has been reported in over 40% of patients taking maintenance therapies (MT) for inflammatory bowel disease (IBD). Studies in other illness groups have shown that nonadherence is related to negative attitudes to treatment. The aim of this study was to assess patients' attitudes to MT for IBD (beliefs about personal need for MT and potential adverse effects) and to identify whether such beliefs are associated with adherence to MT. Methods: A cross‐sectional survey was conducted in which 1871 members of the National Association for Colitis and Crohn's Disease (NACC) completed validated questionnaires assessing beliefs about MT and adherence to MT. Results: Low adherence to MT was reported by 29% of participants and was associated with doubts about personal need for MT (odds ratio [OR] = 0.56; 95% confidence interval [CI]: 0.48–0.64; P < 0.001) and concerns about potential adverse effects (OR = 1.66; 95% CI: 1.42–1.94; P < 0.001). Attitudinal analysis showed that while almost half (48%) of the participants were “accepting” of MT (high necessity, low concerns), a large proportion of the sample (42%) were “ambivalent” about MT (high necessity, high concerns), 6% were “sceptical” (low necessity, high concerns) and 4% were “indifferent” (low necessity, low concerns). Compared to those who were “accepting” of MT, participants in all 3 other attitudinal groups were significantly more likely to be nonadherent. Conclusions: The way in which patients judge their personal need for MT relative to their concerns about MT can be a significant barrier to adherence. Interventions to facilitate optimal adherence to MT for IBD should address such perceptual barriers.
CT-MRI Image Reconstruction with Mask-enhanced Dual-Dictionary Learning

In this work, a mask-enhanced dual-dictionary learning method is proposed to solve the problem of hybrid image reconstruction in magnetic resonance imaging (MRI) and X-ray computed tomography (CT). One dictionary trained from MRI data as a high quality dictionary used to generate a base MRI, and the other dictionary trained from CT data as a low quality dictionary to get the sparse representation. Experiments with real images were performed to evaluate the proposed method. The results reconstructed using the proposed method shows improved MRI image quality compared with the reconstructions using dictionary learning (DLMRI).
Structure and function of inhibitory glycine receptors

Ion transport by peptide channels has been the major theme in the work of the late P. Läuger. His theoretical and experimental approaches provided the basis for a deeper understanding of pore-mediated ion permeation through biological membranes. This review on a ligand–gated ion channel protein from the mammalian brain is dedicated to the memory of this outstanding scientist.
In Vitro Antifungal , Antimicrobial Properties and Chemical Composition of Santolina chamaecyparissus Essential Oil in Syria

The essential oil of the Santolina chamaecyparissus was isolated by herdro distillation using a modified Clevenger apparatus, and its constituents were identified and quantified by GC/MS analyses. The total composition of the essential oil was 92.09%. The main constituents of the essential oil were Artemisia ketone (15.65%). Another compounds present are as follow: Alpha-Amorphene (12.11%), Beta -Phellandrene (10.63%), Beta-Myrcene (7.42%), Nootkatone (6.97%). This study seeks to evaluate the chemical composition and its effect on the growth inhibition of microorganisms. The antibacterial was investigated in vitro against four gram-positive bacteria (Bacillus subitus, Staphylococcus aureus, Streptococcus pyogenes, Micrococus luteus) and six gram-negative bacteria (Escherichia coli, Salmonella typhimurium, Pseudomonas aeruginose, Klebsellia pneumonia, Proteus vulgaris, Vibrio parahaemolyticus), also against six fungi (Fusarium solani, Aspergillus flavus, Penecillium variable, Mucor sp, Rhyzopus sp and Candida albicans). The tested essential oil had different degrees of antibacterial and antifungal activity. The antimicrobial activities of essential oil evaluated in the present study by measuring the inhibition zones using Agar Disk Diffusion method. MIC and MBC varied from 0.4 – 1.6 mg/ml, and from 0.8 – 3.2 mg/ml, respectively, while MIC and MFC ranged from 0.4 to 3.2 and from 0.8 to 6.4 mg/ml respectively.
On the Length and Depth of Temporal Formulae Distinguishing Non-bisimilar Transition Systems

We investigate the minimal length and nesting depth of temporal formulae that distinguish two given non-bisimilar finite pointed transition systems. We show that such formula can always be constructed in length at most exponential in the combined number of states of both transition systems, and give an example with exponential lower bound, for several common temporal languages. We then show that by using renamings of subformulae or explicit assignments the length of the distinguishing formula can always be reduced to one that is bounded above by a cubic polynomial on the combined size of both transition systems. This is also a bound for the size obtained by using DAG representation of formulae. We also prove that the minimal nesting depth for such formula is less than the combined size of the two state spaces and obtain some tight upper bounds.
Attending to Visual or Auditory Verbal Information While Performing Other Concurrent Tasks

Investigation of the effect that a word recognition task has on concurrent nonverbal tasks showed (a) auditory verbal messages affected visual tracking performance but not the detection of brief light flashes in the visual periphery, (b) greater impairment, both of tracking and light detections, when verbal messages were visual rather than auditory. With a kinaesthetic tracking task, errors increased significantly during auditory messages but were even greater during visual messages. There was no interaction between the modality of tracking error feedback (auditory or visual) and the modality of the verbal message. Nor was the decrement from visual messages reduced by changing the presentation format. It is suggested that different temporal characteristics of visual and auditory information affect the attentional demands of verbal messages.
Modèles stochastiques pour des mouvements collectifs de populations

Dans cette these, on s'interesse a des systemes stochastiques modelisant un des phenomenes biologiques les plus mysterieux, les mouvements collectifs de populations. Pour un groupe de N individus, vus comme des particules sans poids ni volume, on etudie deux types de comportements asymptotiques : d'un cote, en temps long, les proprietes d'ergodicite et de flocking, de l'autre, quand le nombre de particules N tend vers l'infini, les phenomenes de propagation du chaos. Le modele, deterministe, de Cucker-Smale, un modele cinetique de champ moyen pour une population sans structure hierarchique, est notre point de depart : les deux premiers chapitres sont consacres a la comprehension de diverses dynamiques stochastiques qui s'en inspirent, du bruit etant rajoute sous differentes formes. Le troisieme chapitre, originellement une tentative d'amelioration de ces resultats, est base sur la methode du developpement en amas, un outil de physique statistique. On prouve l'ergodicite exponentielle de certains processus non- markoviens a drift non-regulier. Dans la derniere partie, on demontre l'existence d'une solution, unique dans un certain sens, pour un systeme stochastique de particules associe au modele chimiotactique de Keller et Segel.
Modulation of a Heterologous Immune Response by the Products of Ascaris suum

ABSTRACT Helminth infections are among the most potent stimulators of Th2-type immune responses and have been widely demonstrated to modify responsiveness to both nonparasite antigens and other infectious agents in a nonspecific manner in infected animals. We investigated the immunomodulatory properties of pseudocoelomic body fluid from adult Ascaris suum gastrointestinal helminths (ABF) and its defined allergen (ABA-1) by examining their effects on the immune response to a heterologous antigen, ovalbumin. Our results indicate that ABF has potent immunomodulatory activity and that the effects observed are consistent with skewing towards a Th2-type response rather than induction of anergy. Our findings show that the immunomodulatory activities of ABF are associated with components other than the major constituent and putative allergen, ABA-1. Furthermore, the allergic responses to ABA-1 are not a result of an intrinsic allergenicity of the protein but are more a reflection of the wider induction of a Th2 response by the infection. Importantly, the induction of interleukin-10 by ABF also suggests that T regulatory cells may play a role in immunomodulation of immune responses by parasitic helminths.
Modulation of cortical inhibition by rTMS – findings obtained from animal models

Abstract Transcranial magnetic stimulation (TMS) has become a popular method to non‐invasively stimulate the human brain. The opportunity to modify cortical excitability with repetitive stimulation (rTMS) has especially gained interest for its therapeutic potential. However, details of the cellular mechanisms of the effects of rTMS are scarce. Currently favoured are long‐term changes in the efficiency of excitatory synaptic transmission, with low‐frequency rTMS depressing it, but high‐frequency rTMS augmenting. Only recently has modulation of cortical inhibition been considered as an alternative way to explain lasting changes in cortical excitability induced by rTMS. Adequate animal models help to highlight stimulation‐induced changes in cellular processes which are not assessable in human rTMS studies. In this review article, we summarize findings obtained with our rat models which indicate that distinct inhibitory cell classes, like the fast‐spiking cells characterized by parvalbumin expression, are most sensitive to certain stimulation protocols, e.g. intermittent theta burst stimulation. We discuss how our findings can support the recently suggested models of gating and homeostatic plasticity as possible mechanisms of rTMS‐induced changes in cortical excitability.
Motivation and involvement in international tourism

Using a sample of international tourists travelling in Portugal, Spain and Italy, this study identifies key issues related with tourist involvement. One of the main aspects in the consumer behavior and the decision processes’ understanding is the concept of involvement (Broderick & Mueller, 1999; Dimanche et al., 1993) because it influences the decision rules used by tourists to reach the final decision (Sirakaya & Woodside, 2005). An empirical study of 600 international tourists reveals that motivation to relax influences tourists’ involvement with the trip. A structural model reveals that when tourists are motivated to relax they get directly more involved with their trip (pleasure and information seeking). The motivation to relax also influences indirectly the tourist involvement with the evaluation and quality perception of the trip through its influence on involvement with the trip planning. Discussion centers on the implications of this model to theory and managerial development of tourism and services strategies. Directions for future research are also presented.