A statistical characterization of on–body fading using the shadowed k���µ fading model

In this paper we investigate the received signal characteristics of on-body communications channels at 2.45 GHz. The hypothetical body area network configuration considered a transmitter node situated on the person’s left waist and receiving nodes positioned on the head, knee and wrist of the person’s right side. The on-body channel measurements were performed in both anechoic and reverberant environments while the person was moving. It was found that the recently proposed shadowed κ‒μ fading model provided an excellent fit to the measured data.

Explorations of identity in Philip K. Dick's Do androids dream of electric sheep?

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

Sign, meaning and violence in Laurell K. Hamilton’s novels : a postmodernist approach

La nature iconoclaste de l'ère postmoderne se manifeste dans une révolution contre les normes littéraires préétablies. Cet iconoclasme est plus flagrant dans la fantaisie urbaine. Dans un environnement désordonné, fragmenté et très stéréotypé, la fantaisie urbaine est considérée comme un événement qui défie tout jugement, et toute stratification sociale. Bien qu'elle ait été bien accueillie par les lecteurs et qu'elle a obtenue de fortes ventes, c'est seulement depuis deux décennies que ces genres ont commencé à attirer l'attention académique. Ce travail peut être considéré comme une tentative pour comprendre la fantaisie urbaine à travers la série d'une de ses écrivains les plus éminents, Laurell K. Hamilton. En conséquence, j’ai choisi trois romans de sa série Anita Blake: Guilty Pleasures (1993), Circus of the Damned (1995) et Blue Moon (1998). Les paramètres stylistiques et thématiques dans ses romans créent une philosophie postmoderne de subversion, qui valide et invalide les discussions sur la structure du signe, la violence, et la réaction du lecteur. Le premier chapitre étudie la construction du sens à travers la structure de la langue de la fantaisie urbaine. Il traite la signification que le résultat de l'interaction entre les différents signes linguistiques. Il suit également l'évolution de ce que Derrida appelle «inflated signs», qui sont au coeur de la régénération du sens à travers les romans. La saturation dans ces signes implique une «absence» qui s'affiche à travers la désintégration du système de la langue et les ruptures récurrentes de sa structure globale. Le deuxième chapitre se concentre sur les tendances de la violence dans les romans de la fantaisie urbaine qui rendent les jeux de pouvoir des personnages truculents et leurs réactions apparaissent inadmissibles. Il examine la violence par rapport à ses causes et sa ii logique. Grâce aux concepts de Derrida de l’‘arché-violence’, de ‘décision’ et de ‘sacrifice,’ je démontre que la violence est inévitable dans le monde créé de Hamilton et dans le monde qu'elle simule. Le troisième chapitre examine la réaction du lecteur sur les événements exotiques et la caractérisation paranormale des romans de Hamilton. Il révèle comment la fantaisie urbaine conteste la conception de Wolfgang Iser de réaction du lecteur et le concept d'‘apparence’ de Jean Baudrillard. J’insiste sur le fait que les lecteurs de la fantaisie urbaine ne sont plus des interprètes ou des réceptifs passifs d'images paranormaux. En effet, l'interaction entre l’auteur et le lecteur, que ces romans entrainent, défie ces conceptions réductrices de la réaction du lecteur.

Formas de exclusión al derecho de propiedad de la población campesina indígena en Argentina: una aproximación al pensamiento de Michael Foucault

En septiembre del año 2010, el Movimiento Nacional Campesino Indígena celebraba su Primer Congreso. Bajo el lema “Somos tierra para alimentar a los pueblos” compartieron y debatieron durante tres días. De este modo, reafirmaron su lucha por la Reforma Agraria Integral y la Soberanía Alimentaria. Se manifestaron por las calles de Buenos Aires para hacer visible “el otro campo”: el de los marginados, ocultados, los pobres, los excluidos del imaginario social, nacional, y también del acceso a los bienes necesarios para el desarrollo una vida digna

U.K. HiGEM: Simulations of desert dust and biomass burning aerosols with a high-resolution atmospheric GCM

The atmospheric component of the United Kingdom’s new High-resolution Global Environmental Model (HiGEM) has been run with interactive aerosol schemes that include biomass burning and mineral dust. Dust emission, transport, and deposition are parameterized within the model using six particle size divisions, which are treated independently. The biomass is modeled in three nonindependent modes, and emissions are prescribed from an external dataset. The model is shown to produce realistic horizontal and vertical distributions of these aerosols for each season when compared with available satellite- and ground-based observations and with other models. Combined aerosol optical depths off the coast of North Africa exceed 0.5 both in boreal winter, when biomass is the main contributor, and also in summer, when the dust dominates. The model is capable of resolving smaller-scale features, such as dust storms emanating from the Bode´ le´ and Saharan regions of North Africa and the wintertime Bode´ le´ low-level jet. This is illustrated by February and July case studies, in which the diurnal cycles of model variables in relation to dust emission and transport are examined. The top-of-atmosphere annual mean radiative forcing of the dust is calculated and found to be globally quite small but locally very large, exceeding 20 W m22 over the Sahara, where inclusion of dust aerosol is shown to improve the model radiative balance. This work extends previous aerosol studies by combining complexity with increased global resolution and represents a step toward the next generation of models to investigate aerosol–climate interactions. 1. Introduction Accurate modeling of mineral dust is known to be important because of its radiative impact in both numerical weather prediction models (Milton et al. 2008; Haywood et

Species-specific responses of Late Quaternary megafauna to climate and humans

Despite decades of research, the roles of climate and humans in driving the dramatic extinctions of large-bodied mammals during the Late Quaternary period remain contentious. Here we use ancient DNA, species distribution models and the human fossil record to elucidate how climate and humans shaped the demographic history of woolly rhinoceros, woolly mammoth, wild horse, reindeer, bison and musk ox. We show that climate has been a major driver of population change over the past 50,000 years. However, each species responds differently to the effects of climatic shifts, habitat redistribution and human encroachment. Although climate change alone can explain the extinction of some species, such as Eurasian musk ox and woolly rhinoceros, a combination of climatic and anthropogenic effects appears to be responsible for the extinction of others, including Eurasian steppe bison and wild horse. We find no genetic signature or any distinctive range dynamics distinguishing extinct from surviving species, emphasizing the challenges associated with predicting future responses of extant mammals to climate and human-mediated habitat change.

Cognição Numérica de crianças pré-escolares brasileiras pela ZAREKI-K

The Numerical Cognition is infl uenced by biological, cognitive, educational and cultural factors. It consists of a primary system, called Number Sense that would be innate and universal, also of secondary systems: the Calculation, implied to perform mathematical operations by means of symbols or words and Number Processing, which is divided into two components, Number Comprehension, related with the understanding of numerical symbols and Number Production, which includes reading, writing and coun-ting numbers. However, studies that show the development of these functions in children of preschool age are scarce. Therefore, aims of this study were to investigate numerical cognition in preschool Brazilian children to demonstrate the construct validity of the ZAREKI-K (A Neuropsychological Battery for the Assessment of Treatment of Numbers and Calculation for preschool children). The participants were 42 children of both genders, who attended public elementary schools; the children were evaluated by this battery and WISC-III. The results indicated signifi cant differences associated with age which children of 6 years had better scores on subtests related to Number Production, Calculation and Number Comprehension, as well moderate and high correlations between some subtests of both instruments, demonstrating the construct validity of the battery. In conclusion, preliminary normative data were obtained for ZAREKI-K. The analyses suggested that it is a promising tool for the assessment of numerical cognition in preschool children.Keywords: Mathematics, number, preschoolers, working memory, Developmental Dyscalculia.

Phosphoregulation of K(+)-Cl(-) cotransporter 4 during changes in intracellular Cl(-) and cell volume

It has long been stated that the K(+)-Cl(-) cotransporters (KCCs) are activated during cell swelling through dephosphorylation of their cytoplasmic domains by a protein phosphatase (PP) but that other enzymes are involved by targeting this PP or the KCCs directly. To date, however, the role of signaling intermediates in KCC regulation has been deduced from indirect evidence rather than in vitro phosphorylation studies, and examined after simulation of ion transport through cell swelling or N-ethylmaleimide treatment. In this study, the oocyte expression system was used to examine the effects of changes in cell volume (C(VOL)) and intracellular [Cl(-)] ([Cl(-)](i)) on the activity and phosphorylation levels (P(LEV)) of KCC4, and determine whether these effects are mediated by PP1 or phorbol myristate acetate (PMA)-sensitive effectors. We found that (1) low [Cl(-)](i) or low C(VOL) leads to decreased activity but increased P(LEV), (2) high C(VOL) leads to increased activity but no decrease in P(LEV) and (3) calyculin A (Cal A) or PMA treatment leads to decreased activity but no increase in P(LEV). Thus, we have shown for the first time that one of the KCCs can be regulated through direct phosphorylation, that changes in [Cl(-)](i) or C(VOL) modify the activity of signaling enzymes at carrier sites, and that the effectors directly involved do not include a Cal A-sensitive PP in contrast to the widely held view. J. Cell. Physiol. 219: 787-796, 2009. (c) 2009 Wiley-Liss, Inc.

A novel rare variant in SCN1Bb linked to Brugada syndrome and SIDS by combined modulation of Na(v)1.5 and K(v)4.3 channel currents.

BACKGROUND Cardiac sodium channel β-subunit mutations have been associated with several inherited cardiac arrhythmia syndromes. OBJECTIVE To identify and characterize variations in SCN1Bb associated with Brugada syndrome (BrS) and sudden infant death syndrome (SIDS). METHODS All known exons and intron borders of the BrS-susceptibility genes were amplified and sequenced in both directions. Wild type (WT) and mutant genes were expressed in TSA201 cells and studied using co-immunoprecipitation and whole-cell patch-clamp techniques. RESULTS Patient 1 was a 44-year-old man with an ajmaline-induced type 1 ST-segment elevation in V1 and V2 supporting the diagnosis of BrS. Patient 2 was a 62-year-old woman displaying a coved-type BrS electrocardiogram who developed cardiac arrest during fever. Patient 3 was a 4-month-old female SIDS case. A R214Q variant was detected in exon 3A of SCN1Bb (Na(v)1B) in all three probands, but not in any other gene previously associated with BrS or SIDS. R214Q was identified in 4 of 807 ethnically-matched healthy controls (0.50%). Co-expression of SCN5A/WT + SCN1Bb/R214Q resulted in peak sodium channel current (I(Na)) 56.5% smaller compared to SCN5A/WT + SCN1Bb/WT (n = 11-12, P<0.05). Co-expression of KCND3/WT + SCN1Bb/R214Q induced a Kv4.3 current (transient outward potassium current, I(to)) 70.6% greater compared with KCND3/WT + SCN1Bb/WT (n = 10-11, P<0.01). Co-immunoprecipitation indicated structural association between Na(v)β1B and Na(v)1.5 and K(v)4.3. CONCLUSION Our results suggest that R214Q variation in SCN1Bb is a functional polymorphism that may serve as a modifier of the substrate responsible for BrS or SIDS phenotypes via a combined loss of function of sodium channel current and gain of function of transient outward potassium current.

Loss-of-function mutations in the KCNJ8-encoded Kir6.1 K(ATP) channel and sudden infant death syndrome.

BACKGROUND Approximately 10% of sudden infant death syndrome (SIDS) may stem from cardiac channelopathies. The KCNJ8-encoded Kir6.1 (K(ATP)) channel critically regulates vascular tone and cardiac adaptive response to systemic metabolic stressors, including sepsis. KCNJ8-deficient mice are prone to premature sudden death, particularly with infection. We determined the spectrum, prevalence, and function of KCNJ8 mutations in a large SIDS cohort. METHODS AND RESULTS Using polymerase chain reaction, denaturing high-performance liquid chromatography, and DNA sequencing, comprehensive open reading frame/splice-site mutational analysis of KCNJ8 was performed on genomic DNA isolated from necropsy tissue on 292 unrelated SIDS cases (178 males, 204 white; age, 2.9±1.9 months). KCNJ8 mutations were coexpressed heterologously with SUR2A in COS-1 cells and characterized using whole-cell patch-clamp. Two novel KCNJ8 mutations were identified. A 5-month-old white male had an in-frame deletion (E332del) and a 2-month-old black female had a missense mutation (V346I). Both mutations localized to Kir6.1's C-terminus, involved conserved residues and were absent in 400 and 200 ethnic-matched reference alleles respectively. Both cases were negative for mutations in established channelopathic genes. Compared with WT, the pinacidil-activated K(ATP) current was decreased 45% to 68% for Kir6.1-E332del and 40% to 57% for V346I between -20 mV and 40 mV. CONCLUSIONS Molecular and functional evidence implicated loss-of-function KCNJ8 mutations as a novel pathogenic mechanism in SIDS, possibly by predisposition of a maladaptive cardiac response to systemic metabolic stressors akin to the mouse models of KCNJ8 deficiency.