Alien Registration- Landry, Annie (Millinocket, Penobscot County)

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Étude des propriétés optiques et électriques dans les verres P₂O₅-Na₂O-Nb₂O₅ en vue de leur intégration dans des systèmes de détection de gaz à haute température

L’incorporation d’oxyde de niobium, un métal de transition à valence multiple, dans des verres de phosphates permettrait leur intégration dans des systèmes de détection de gaz à haute température puisqu’ils présentent des propriétés optiques et électriques modulables en fonction de la température et de l’atmosphère. Dans le cadre de cette maîtrise, les verres (60-x)P₂O₅-xNa₂O-40Nb₂O₅ où x = 23, 27, 30 et 33 %mol ont été étudiés afin d’évaluer l’influence de la composition et de la température sur l’état d’oxydation du niobium. Sous forme d’oxyde, le niobium se retrouve généralement dans un état d’oxydation Nb(V) de forme Nb₂O₅, un composé incolore. Lorsque l’oxyde de niobium est réduit partiellement, il se retrouve sous forme NbO₂ d’état d’oxydation Nb(IV) qui présente une coloration bleu-noir. Les verres ont été traités thermiquement sous air et sous atmosphère partielle d’hydrogène (90Ar/10H₂) entre 450 et 630 °C. Les propriétés optiques ont été mesurées par spectrophotométrie UV-visible et permettent d’observer une large bande d’absorption dans le domaine du visible jusqu’au proche infrarouge suite aux traitements thermiques réducteurs. Une analyse de Résonance Paramagnétique Électronique (RPE) permet de révéler la présence d’espèces Nb⁴⁺ responsables de la coloration bleu-noir des verres. Les analyses Raman démontrent que le niobium se retrouve en sites octaédriques NbO₆ pour toutes les compositions et qu’une diminution de la concentration en ions Na⁺ permet d’augmenter le nombre d’oxygènes pontants et favorise ainsi la réduction du niobium. De plus, les verres présentent une conductivité électrique mixte ionique-électronique entre 10⁻¹⁰ et 10⁻³ S·cm⁻¹ sur une gamme de températures entre 25 et 575 °C. La conductivité ionique est due à la mobilité des ions Na⁺ dans le réseau vitreux et est plus importante lorsque la concentration de ce porteur de charge augmente. La conductivité électronique est due à la présence d’espèces Nb⁵⁺ et Nb⁴⁺. La coloration bleu foncé des verres ainsi que la conductivité électronique peuvent être expliquées par des phénomènes de transfert de charge soit respectivement le transfert de charge d’intervalence et le saut de petit polaron. Finalement, des analyses DRX, DSC, de densité, d’indice de réfraction et d’analyse thermogravimétrique (ATG) ont aussi été effectuées sur ces verres.The incorporation of niobium oxide, a mixed valency transition metal, in phosphate glasses would allow their integration in high temperature gas detection systems because they have optical and electrical properties that can be modulated according to the temperature and the atmosphere. In this study, the glasses (60-x)P₂O₅-xNa₂O-40Nb₂O₅ where x = 23, 27, 30 and 33 mol% were studied to evaluate the influence of the composition and the temperature on the oxidation state of niobium. In the oxide form, niobium is generally found in an oxidation state Nb(V) of composition Nb₂O₅, a colorless compound. When the niobium oxide is reduced, it is found in NbO2 composition with Nb(IV) oxidation state, which exhibits a dark-blue coloration. The glasses were heat-treated in air and hydrogenated atmosphere (90Ar/10H₂) between 450 and 630 °C. The transmittance properties were measured by UV-visible spectrophotometry resulting in a broad absorption band in the visible range up to the near-infrared following reductive thermal treatments. Electron paramagnetic resonance analysis revealed the presence of Nb⁴⁺ species responsible for the dark-blue coloration of glasses. Raman analyzes show that niobium is found in octahedral sites NbO₆ for all the compositions and a decrease in Na⁺ ions makes it possible to increase the number of bridging oxygens and thus favors the reduction of niobium. In addition, the glasses have a mixed electrical ion-electron conductivity between 10⁻¹⁰ and 10⁻³ S·cm⁻¹ over a temperature range between 25 and 575 °C. The ionic conductivity is due to the mobility of the Na⁺ ions in the vitreous lattice and is more important when the concentration of this charge carrier increases. Electronic conductivity is due to the presence of Nb⁵⁺ and Nb⁴⁺ species. The dark-blue coloration of the glasses and the electronic conductivity can be explained by interatomic charge transfer phenomenons, respectively know as intervalence charge transfer and the small polaron hopping. Moreover, XRD, DSC, density, refractive index and TGA analyzes were also performed on theses glasses

Regards de Nunavimmiuts sur les raisons de la consommation et ses effets

Dans le présent article sont exposés les résultats d’une étude sur la consommation de substances psychoactives au Nunavik. Le volet qualitatif de cette étude comporte 108 entretiens semi-dirigés auprès de jeunes, de parents, de leaders et d’Aînés de quatre villages. L’analyse de contenu thématique des résultats a mis en lumière différentes raisons et différents effets de la consommation au Nunavik du point de vue des participants. Parmi les raisons évoquées par les interviewés, on retrouve le plaisir, l’ennui et le manque d’activités, la « colonisation », l’adaptation (coping) à divers problèmes (pauvreté, abus, suicide) et la transmission intergénérationnelle. Sur la question des conséquences de la consommation, les effets sur la famille, dont la violence conjugale et la négligence envers les enfants, mais aussi les comportements déviants, incluant la conduite avec capacités affaiblies, les voies de fait et les délits lucratifs ont été évoqués. Ces résultats sont discutés à la lumière des connaissances actuelles sur les causes et conséquences de la consommation chez les Inuits et les non-Inuits.Results from a study on the use of psychoactive substances in Nunavik are presented. The qualitative part of the study consisted of 108 semi-structured qualitative interviews with youth, parents, leaders and elders of four villages. Thematic content analysis of the material revealed different reasons and consequences of substance use and abuse in Nunavik, from the respondent’s standpoint. Among the reasons, respondents evoked pleasure, boredom and lack of activities, “colonization,” coping about different problems (poverty, victimization and suicide) and also intergenerational transmission. Concerning consequences, they mostly talked about family impacts including intimate violence and child neglect, but also about other deviant behaviors like drinking and driving and lucrative crimes. These results are discussed according to actual knowledge about causes and consequences of substance use among Inuit and non-Inuit.Este artículo presenta los resultados de un estudio sobre el consumo de sustancias psicoactivas en Nunavik. El estudio incluye 108 entrevistas cualitativas semidirigidas con jóvenes, padres de familia, líderes y ancianos de cuatro poblaciones. El análisis del contenido temático de los resultados mostró diferentes razones y diversos efectos del consumo de dichas sustancias, según los participantes. Entre las razones evocadas se mencionan el placer, el aburrimiento y la falta de actividades, la “colonización”, la necesidad de enfrentar diversos problemas (la pobreza, el abuso, el suicidio) y la transmisión intergeneracional. Respecto de las consecuencias del consumo, se mencionaron principalmente los impactos sobre la familia, por ejemplo la violencia conyugal y la negligencia de los niños, además de comportamientos desviantes como el conducir con facultades disminuidas, las agresiones y los delitos con lucro. Estos resultados se evalúan considerando los conocimientos actuales sobre las causas y las consecuencias del consumo tanto en los Inuit como en la población general

A small protein coded within the mitochondrial canonical gene nd4 regulates mitochondrial bioenergetics

BACKGROUND: Mitochondria have a central role in cellular functions, aging, and in certain diseases. They possess their own genome, a vestige of their bacterial ancestor. Over the course of evolution, most of the genes of the ancestor have been lost or transferred to the nucleus. In humans, the mtDNA is a very small circular molecule with a functional repertoire limited to only 37 genes. Its extremely compact nature with genes arranged one after the other and separated by short non-coding regions suggests that there is little room for evolutionary novelties. This is radically different from bacterial genomes, which are also circular but much larger, and in which we can find genes inside other genes. These sequences, different from the reference coding sequences, are called alternatives open reading frames or altORFs, and they are involved in key biological functions. However, whether altORFs exist in mitochondrial protein-coding genes or elsewhere in the human mitogenome has not been fully addressed. RESULTS: We found a downstream alternative ATG initiation codon in the + 3 reading frame of the human mitochondrial nd4 gene. This newly characterized altORF encodes a 99-amino-acid-long polypeptide, MTALTND4, which is conserved in primates. Our custom antibody, but not the pre-immune serum, was able to immunoprecipitate MTALTND4 from HeLa cell lysates, confirming the existence of an endogenous MTALTND4 peptide. The protein is localized in mitochondria and cytoplasm and is also found in the plasma, and it impacts cell and mitochondrial physiology. CONCLUSIONS: Many human mitochondrial translated ORFs might have so far gone unnoticed. By ignoring mtaltORFs, we have underestimated the coding potential of the mitogenome. Alternative mitochondrial peptides such as MTALTND4 may offer a new framework for the investigation of mitochondrial functions and diseases

Effectiveness of Multidrug Antiretroviral Regimens to Prevent Mother-to-Child Transmission of HIV-1 in Routine Public Health Services in Cameroon

International audienceBACKGROUND: Multidrug antiretroviral (ARV) regimens including HAART and short-course dual antiretroviral (sc-dARV) regimens were introduced in 2004 to improve Prevention of Mother-to-Child Transmission (PMTCT) in Cameroon. We assessed the effectiveness of these regimens from 6-10 weeks and 12 months of age, respectively. METHODOLOGY/FINDINGS: We conducted a retrospective cohort study covering the period from October 2004 to March 2008 in a reference hospital in Cameroon. HIV-positive pregnant women with CD4 or = 37 weeks, women received sd-NVP during labour [regimen 4]. Infants received sd-NVP plus ZDV and 3TC for 7 days or 30 days. Early diagnosis (6-10 weeks) was done, using b-DNA and subsequently RT-PCR. We determined early MTCT rate and associated risk factors using logistic regression. The 12-month HIV-free survival was assessed using Cox regression. Among 418 mothers, 335 (80%) received multidrug ARV regimens (1, 2, and 3) and MTCT rate with multidrug regimens was 6.6% [95%CI: 4.3-9.6] at 6 weeks, without any significant difference between regimens. Duration of mother's ARV regimen < 4 weeks [OR = 4.7, 95%CI: 1.3-17.6], mother's CD4 < 350 cells/mm(3) [OR = 6.4, 95%CI: 1.8-22.5] and low birth weight [OR = 4.0, 95%CI: 1.4-11.3] were associated with early MTCT. By 12 months, mixed feeding [HR = 8.7, 95%CI: 3.6-20.6], prematurity [HR = 2.3, 95%CI: 1.2-4.3] and low birth weight were associated with children's risk of progressing to infection or death. CONCLUSIONS: Multidrug ARV regimens for PMTCT are feasible and effective in routine reference hospital. Early initiation of ARV during pregnancy and proper obstetrical care are essential to improve PMTCT

Early Detection of Acute Renal Lesions by Serum Cystatin C in Children at Hospital and University Centre of Brazzaville

&nbsp;Introduction: Acute Kidney Injury (AKI) is considered one of the main public health problems. The effective management of these alterations is based on the early detection of renal lesions. The objective of this study was to evaluate the contribution of the Cystatin C (CysC) assay in the early diagnosis of acute kidney injury (AKI) in children hospitalized in pediatric intensive care units in Brazzaville. Materials and Methods: Sixty children at high risk of developing AKI were included. Consent form signed was obtained from parents, socio-demographic data, weight and height of children recorded. Creatinine (Cr), CysC and urea were assayed in serum 24 hours after admission. Glomerular filtration clearance was estimated using serum creatinine and CysC. Glomerular filtration rate (GFR) was calculated from CysC and Cr. The diagnostic accuracy was determined by comparing the results of CysC to those of Cr (considered as a reference biomarker). Results: The median age was 5 years (with extremes ranging from 1 month to 17 years). Cr, CysC, urea, and GFR/Cr (mean ± standard deviation [range]) were 0.94±1.17 (0.2–1.4 mg/dl), 0.14 ± 0.062 (0.053-0.095 mg/l), 46.65±47.75 (15.0–45.0 mg/dl), 81.85±31.90 (≥190 ml/min per 1.73 m2 , respectively. The level of CysC in patients with ARL was significantly higher than that of children with normal renal function (p&lt;0.001). CysC detected 71.7% of children with AKI versus 26.7% with Cr. The performance characteristics (area under the curve, sensitivity, specificity) were 0.63, 89.6% and 37.5% for creatinine and 0.76, 92.9% and 54.8% for cystatin respectively. Analysis of the characteristics of the two curves revealed that CysC had a significantly higher diagnostic capacity (p&lt;0.001). Conclusion: Our results show that the performance of serum CysC in detecting AKI early was superior to that of serum Cr in children hospitalized in pediatric intensive care units in Brazzaville

Des routes et des hommes : la construction des échanges par les itinéraires et les transports

Les circulations humaines façonnent le paysage montagnard, traçant les routes qui permettent de franchir les obstacles, de créer un lien avec la plaine, de développer les activités économiques. Portant sur une diversité de territoires, cet ouvrage nous invite à mieux comprendre comment l’homme a ouvert des passages pour dépasser les frontières naturelles et culturelles des montagnes. La présentation de découvertes archéologiques, l’analyse de sources méconnues, l’étude du rôle de la technique et de la cartographie en dressent un panorama allant de l’Antiquité au xxe siècle. Le Congrès national des sociétés historiques et scientifiques rassemble chaque année universitaires, membres de sociétés savantes et jeunes chercheurs. Ce recueil est issu de travaux présentés lors du 142e Congrès sur le thème « Circulations montagnardes, circulations européennes »

Alien Registration- Landry, Annie (Millinocket, Penobscot County)

https://digitalmaine.com/alien_docs/8097/thumbnail.jp