132 research outputs found

    Exact wavefunctions for excitations of the nu=1/3 fractional quantum Hall state from a model Hamiltonian

    Full text link
    We study fractional quantum Hall states in the cylinder geometry with open boundaries. By truncating the Coulomb interactions between electrons we show that it is possible to construct infinitely many exact eigenstates including the ground state, quasiholes, quasielectrons and the magnetoroton branch of excited states.Comment: 7 pages, 3 figures, longer published versio

    Regard sur les croyances des enseignants et sur le bilinguisme

    Get PDF
    The Bas-St-Laurent region is becoming increasingly diverse. Indeed, the rate of immigrant students is increasing, with only seven of the 85 schools in the area without immigrant students in 2016 (Borri-Anadon & Hirsch, 2021). Furthermore, the rate of students with special needs is also increasing (BDSOQ, 2021). However, very little research has examined the bilingualism of students with special needs (Conner & al., 2020; Howard & al., 2021). This conference proceedings offer to look into two concepts that will be investigated in this research: teacher beliefs and bilingualism. After defining these concepts, teachers’ beliefs from previous research will be presented. Finally, a methodology for studying teachers’ beliefs about bilingual students with special needs will be considered.Le Bas-St-Laurent devient une rĂ©gion de plus en plus diversifiĂ©e. En effet, le taux d’élèves immigrants augmente avec, en 2016, seulement sept des 85 Ă©coles de la rĂ©gion n’accueillant aucun Ă©lève issu de l’immigration (Borri-Anadon et Hirsch, 2021). De plus, le taux d’élèves handicapĂ©s ou en difficultĂ© d’adaptation ou d’apprentissage (EHDAA) augmente aussi (BDSOQ, 2021). Toutefois, très peu de recherches se sont penchĂ©es sur le bilinguisme des Ă©lèves en adaptation scolaire (Conner et al., 2020; Howard et al., 2021). Cet acte de colloque propose un regard sur deux concepts qui y seront Ă  l’étude soit les croyances des enseignants et le bilinguisme. Après avoir dĂ©fini ces concepts, des croyances des enseignants issues de la littĂ©rature seront prĂ©sentĂ©es. Finalement, une mĂ©thodologie permettant l’étude des croyances des enseignants Ă  l’égard des EHDAA bilingues sera envisagĂ©e

    The attentional blink impairs detection and delays encoding of visual information: Evidence from human electrophysiology

    Get PDF
    This article explores the time course of the functional interplay between detection and encoding stages of information processing in the brain and the role they play in conscious visual perception. We employed a multitarget rapid serial visual presentation (RSVP) approach and examined the electrophysiological P3 component elicited by a target terminating an RSVP sequence. Target-locked P3 activity was detected both at frontal and parietal recording sites and an independent component analysis confirmed the presence of two distinct P3 components. The posterior P3b varied with intertarget lag, with diminished amplitude and postponed latency at short relative to long lags—an electroencephalographic signature of the attentional blink (AB). Under analogous conditions, the anterior P3a was also reduced in amplitude but did not vary in latency. Collectively, the results provide an electrophysiological record of the interaction between frontal and posterior components linked to detection (P3a) and encoding (P3b) of visual information. Our findings suggest that, although the AB delays target encoding into working memory, it does not slow down detection of a target but instead reduces the efficacy of this process. A functional characterization of P3a in attentive tasks is discussed with reference to current models of the AB phenomenon

    Expression of HIV-1 genes in podocytes alone can lead to the full spectrum of HIV-1-associated nephropathy

    Get PDF
    Expression of HIV-1 genes in podocytes alone can lead to the full spectrum of HIV-1-associated nephropathy.BackgroundHuman immunodeficiency virus (HIV)-1-associated nephropathy (HIVAN) is characterized by collapsing focal and segmental glomerulosclerosis (FSGS) and microcystic tubular dilatation. HIV-1 infection is also associated with other forms of nephropathy, including mesangial hyperplasia. Since HIV-1 gene products are detected in podocytes and other renal cells, it remains uncertain whether podocyte-restricted HIV-1 gene expression can account for the full spectrum of renal lesions involving nonpodocytes.MethodsTo define the role of podocyte-restricted HIV-1 gene expression in the progression of HIVAN, we generated transgenic mice that express nonstructural HIV-1 genes selectively in podocytes.ResultsFour of the seven founder mice developed proteinuria and nephropathy. In a subsequently established transgenic line, reverse transcription-polymerase chain reaction (RT-PCR) analysis detected mRNAs for vif, vpr, nef, and spliced forms of tat and rev, but not vpu, in the kidney. In situ hybridization localized HIV-1 RNA to the podocyte. Transgenic mice on FVB/N genetic background exhibited cuboidal morphology of podocytes with reduced extension of primary and foot processes at 2 weeks of age. After 3 weeks of age, these mice developed massive and nonselective proteinuria with damage of podocytes and other glomerular cells and, after 4 weeks of age, collapsing FSGS and microcystic tubular dilatation. In marked contrast, transgenic mice with C57BL/6 genetic background showed either normal renal histology or only mild mesangial expansion without overt podocyte damage.ConclusionThe present study demonstrates that podocyte-restricted expression of HIV-1 gene products is sufficient for the development of collapsing glomerulosclerosis in the setting of susceptible genetic background

    Toxicity report of once weekly radiation therapy for low-risk prostate adenocarcinoma: preliminary results of a phase I/II trial

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Increasing clinical data supports a low α/β ratio for prostate adenocarcinoma, potentially lower than that of surrounding normal tissues. A hypofractionated, weekly radiation therapy (RT) schedule should result in improved tumour control, reduced acute toxicity, and similar or decreased late effects. We report the toxicity profile of such treatment.</p> <p>Materials and Methods</p> <p>We conducted a multi-institution phase I/II trial of three-dimensional conformal radiation therapy (3D-CRT) for favourable-risk prostate cancer (T1a-T2a, Gleason ≤ 6 and PSA < 10 ng/ml). RT consisted of 45 Gy in nine 5 Gy fractions, once weekly. Primary end-points were feasibility and late gastrointestinal (GI) toxicity (RTOG scale), while secondary end-points included acute GI toxicity, acute and late genitourinary (GU) toxicity, biochemical control, and survival.</p> <p>Results</p> <p>Between 2006 and 2008, 80 patients were treated. No treatment interruptions occurred. The median follow-up is 33 months (range: 20-51). Maximal grade 1, 2, and 3 acute (< 3 months) GU toxicity was 29%, 31% and 5% respectively (no grade 4). Acute GI grade 1 toxicity was reported in 30% while grade 2 occurred in 14% (no grade 3 or 4). Crude late grade ≥ 3 toxicity rates at 31 months were 2% for both GU and GI toxicity. Cumulative late grade ≥ 3 GI toxicity at 3 years was 11%. Two patients had PSA failure according to the Phoenix definition. The three-year actuarial biochemical control rate is 97%.</p> <p>Conclusions</p> <p>Weekly RT with 45 Gy in 9 fractions is feasible and results in comparable toxicity. Long term tumour control and survival remain to be assessed.</p

    HIV-Nef Protein Persists in the Lungs of Aviremic Patients with HIV and Induces Endothelial Cell Death

    Get PDF
    It remains a mystery why HIV-associated end-organ pathologies persist in the era of combined antiretroviral therapy (ART). One possible mechanism is the continued production of HIV-encoded proteins in latently HIV-infected T cells and macrophages. The proapoptotic protein HIV-Nef persists in the blood of ART-treated patients within extracellular vesicles (EVs) and peripheral blood mononuclear cells. Here we demonstrate that HIV-Nef is present in cells and EVs isolated from BAL of patients on ART. We hypothesize that HIV-Nef persistence in the lung induces endothelial apoptosis leading to endothelial dysfunction and further pulmonary vascular pathologies. The presence of HIV-Nef in patients with HIV correlates with the surface expression of the proapoptotic endothelial-monocyte–activating polypeptide II (EMAPII), which was implicated in progression of pulmonary emphysema via mechanisms involving endothelial cell death. HIV-Nef protein induces EMAPII surface expression in human embryonic kidney 293T cells, T cells, and human and mouse lung endothelial cells. HIV-Nef packages itself into EVs and increases the amount of EVs secreted from Nef-expressing T cells and Nef-transfected human embryonic kidney 293T cells. EVs from BAL of HIV+ patients and Nef-transfected cells induce apoptosis in lung microvascular endothelial cells by upregulating EMAPII surface expression in a PAK2-dependent fashion. Transgenic expression of HIV-Nef in vascular endothelial–cadherin+ endothelial cells leads to lung rarefaction, characterized by reduced alveoli and overall increase in lung inspiratory capacity. These changes occur concomitantly with lung endothelial cell apoptosis. Together, these data suggest that HIV-Nef induces endothelial cell apoptosis via an EMAPII-dependent mechanism that is sufficient to cause pulmonary vascular pathologies even in the absence of inflammation
    • …
    corecore