2,697 research outputs found

    Estudio de sensibilidad de amebas de vida libre a distintos agentes desinfectantes

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    76 p.Las amebas de vida libre (AVL) son protozoos que se desarrollan en variados ambientes, principalmente, en aguas temperadas que se mantienen relativamente inmóviles como las piscinas, lagunas y estanques. Existen numerosas AVL en el suelo y en el agua del medio ambiente, pero solamente especies de los géneros Naegleria, Vahlkampfia, Acanthamoeba, Balamuthia y Hartmannella han sido encontrados en pacientes humanos. Una de las principales características de las amebas en estudio es que son resistentes a los desinfectantes, a los cambios de temperatura y a la desecación. Estudios revelan que han sido identificadas incluso en el hielo polar. El objetivo principal de este trabajo fue determinar la resistencia de AVL, a distintos agentes desinfectantes para evaluar el grado de resistencia de cada género. La metodología utilizada en este estudio comenzó aislando AVL obtenidas de cultivos positivos de muestras de agua, las que se cultivaron en un medio no nutritivo, para luego de varias etapas obtener cultivos axénicos de cada género y a continuación ser sometidas a distintos desinfectantes en distintas concentraciones visualizando el efecto de estos por la técnica de difusión en pocillo. Podemos concluir a partir de esta larga investigación que el mejor agente desinfectante contra las AVL es el alguicida, siendo altamente efectivo en el 100% de las muestras. Además podemos decir que los principales agentes desinfectantes que se utilizan comúnmente para la desinfección de las aguas como el cloro, bromo, yodo y cobre, no son efectivos contra la erradicación de las AVL. Por lo tanto a partir de este estudio se deja de manifiesto que el alguicida es un potente agente eliminador de AVL de bajo costo, el que podría ser evaluado como un posible desinfectante de las aguas de Chile

    Certifiquei : Gerenciamento de Certificados em eventos acadêmicos

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    Orientador : Prof. Dr. Alexander Robert KutzkeTrabalho (Graduação) - Universidade Federal do Paraná, Setor de Educação Profissional e Tecnológica, Curso em Tecnologia em Análise e Desenvolvimento de Sistemas.Inclui referências: p. 46Resumo : O projeto aqui apresentado tem como base a experiência obtida pelos autores na organização e emissão dos certificados de horas formativas para os alunos participantes do evento acadêmico SATADS - Semana Acadêmica do Curso de Tecnologia em Análise e Desenvolvimento de Sistemas em 2018. O controle de presença no evento criado pelo Centro Acadêmico do curso é de própria responsabilidade e feito a sua escolha, visto que é uma atividade cultural proposta por pela entidade estudantil. Os certificados são documentos oficiais que atestam a participação dos alunos em eventos acadêmicos para fins de comprovação das horas em atividades extracurriculares, obrigatórias para a formação do estudante. Este sistema propõe auxiliar os Centros Acadêmicos na certificação de horas formativas de cada participante levando em conta sua presença em eventos acadêmicos

    Transmission properties of a single metallic slit: From the subwavelength regime to the geometrical-optics limit

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    In this work we explore the transmission properties of a single slit in a metallic screen. We analyze the dependence of these properties on both slit width and angle of incident radiation. We study in detail the crossover between the subwavelength regime and the geometrical-optics limit. In the subwavelength regime, resonant transmission linked to the excitation of waveguide resonances is analyzed. Linewidth of these resonances and their associated electric field intensities are controlled by just the width of the slit. More complex transmission spectra appear when the wavelength of light is comparable to the slit width. Rapid oscillations associated to the emergence of different propagating modes inside the slit are the main features appearing in this regime.Comment: Accepted for publication in Phys. Rev.

    Unusual manganese enrichment in the Mesoarchean Mozaan Group, Pongola Supergroup, South Africa

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    An unusual sediment-hosted manganese deposit is described from the Mesoarchean Mozaan Group, Pongola Supergroup, South Africa. MnO contents up to 15 wt.% were observed in marine clastic and chemical sedimentary rocks. Mn enrichment is interpreted to have resulted from the hydrothermal alteration of manganiferous shale and BIF parent rocks, the primary MnO contents of which are as high as 8.5 wt.%. A detailed mineralogical and petrographic study shows that these parent rocks are characterized by manganoan siderite, ferroan rhodochrosite and other Mn-Fe-rich mineral phases, such as kutnohorite and Fe-Mn-chlorite. Their hypogene alteration gave rise to a diversification of mineral assemblages where ferroan tephroite, calcian rhodochrosite, rhodochrosite, pyrochroite, pyrophanite, cronstedtite, manganoan Fe-rich chlorite and manganoan phlogopite partially or totally replaced the previous mineral assemblage. Thermodynamic modeling performed on chlorite phases associated with the described mineral assemblages illustrates a decrease of average crystallization temperatures from ca. 310 °C during early metamorphic stages to ca. 250 °C during a hydrothermal stage. Mineral transformation processes were thus related to retrograde metamorphism and/or hydrothermal alteration post-dating metamorphism and gave rise to progressive Mn enrichment from unaltered parent to altered rocks. The timing of hypogene alteration was constrained by 40Ar/39Ar dating to between about 1500 and 1100 Ma ago, reflecting tectonic processes associated with the Namaqua-Natal orogeny along the southern Kaapvaal Craton margin. Manganiferous shale and BIF of the Mozaan Group may represent the oldest known examples of primary sedimentary Mn deposition, related to oxidation of dissolved Mn(II) by free oxygen in a shallow marine environment. Oxygenic photosynthesis would have acted as a first-order control during Mn precipitation. This hypothesis opens a new perspective for better constraining secular evolution of sediment-hosted mineral deposits linked to oxygen levels in the atmosphere-hydrosphere system during the Archean Eon

    Powdery mildew resistance genes in vines: an opportunity to achieve a more sustainable viticulture

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    Grapevine (Vitis vinifera) is one of the main fruit crops worldwide. In 2020, the total surface area planted with vines was estimated at 7.3 million hectares. Diverse pathogens affect grapevine yield, fruit, and wine quality of which powdery mildew is the most important disease prior to harvest. Its causal agent is the biotrophic fungus Erysiphe necator, which generates a decrease in cluster weight, delays fruit ripening, and reduces photosynthetic and transpiration rates. In addition, powdery mildew induces metabolic reprogramming in its host, affecting primary metabolism. Most commercial grapevine cultivars are highly susceptible to powdery mildew; consequently, large quantities of fungicide are applied during the productive season. However, pesticides are associated with health problems, negative environmental impacts, and high costs for farmers. In paralleled, consumers are demanding more sustainable practices during food production. Therefore, new grapevine cultivars with genetic resistance to powdery mildew are needed for sustainable viticulture, while maintaining yield, fruit, and wine quality. Two main gene families confer resistance to powdery mildew in the Vitaceae, Run (Resistance to Uncinula necator) and Ren (Resistance to Erysiphe necator). This article reviews the powdery mildew resistance genes and loci and their use in grapevine breeding program

    Oral metronomic vinorelbine combined with endocrine therapy in hormone receptor-positive HER2-negative breast cancer: SOLTI-1501 VENTANA window of opportunity trial

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    Breast cancer; Metronomic; VinorelbineCáncer de mama; Quimioterapia metronómica; VinorelbinaCàncer de mama; Quimioteràpia metronòmica; VinorelbinaBackground: The biological effect of oral metronomic vinorelbine (mVNB) alone or in combination with endocrine therapy in patients with hormone receptor-positive (HR+)/HER2-negative breast cancer has been scarcely addressed. Methods: Postmenopausal women with untreated stage I-III HR+/HER2-negative breast cancer were randomized (1:1:1) to receive 3 weeks of letrozole (LTZ) 2.5 mg/day, oral mVNB 50 mg 3 days/week, or the combination. The primary objective was to evaluate, within PAM50 Luminal A/B disease, if the anti-proliferative effect of LTZ+mVNB was superior to monotherapy. An anti-proliferative effect was defined as the mean relative decrease of the PAM50 11-gene proliferation score in combination arm vs. both monotherapy arms. Secondary objectives included the evaluation of a comprehensive panel of breast cancer-related genes and safety. An unplanned analysis of stromal tumor-infiltrating lymphocytes (sTILs) was also performed. PAM50 analyses were performed using the nCounter®-based Breast Cancer 360™ gene panel, which includes 752 genes and 32 signatures. Results: Sixty-one patients were randomized, and 54 paired samples (89%) were analyzed. The main patient characteristics were mean age of 67, mean tumor size of 1.7 cm, mean Ki67 of 14.3%, stage I (55.7%), and grades 1-2 (90%). Most baseline samples were PAM50 Luminal A (74.1%) or B (22.2%). The anti-proliferative effect of 3 weeks of LTZ+mVNB (- 73.2%) was superior to both monotherapy arms combined (- 49.9%; p = 0.001) and mVNB (- 19.1%; p < 0.001). The anti-proliferative effect of LTZ+mVNB (- 73.2%) was numerically higher compared to LTZ (- 65.7%) but did not reach statistical significance (p = 0.328). LTZ+mVNB induced high expression of immune-related genes and gene signatures, including CD8 T cell signature and PDL1 gene and low expression of ER-regulated genes (e.g., progesterone receptor) and cell cycle-related and DNA repair genes. In tumors with ≤ 10% sTILs at baseline, a statistically significant increase in sTILs was observed following LTZ (paired analysis p = 0.049) and LTZ+mVNB (p = 0.012). Grade 3 adverse events occurred in 3.4% of the cases. Conclusions: Short-term mVNB is well-tolerated and presents anti-proliferative activity alone and in combination with LTZ. The high expression of immune-related biological processes and sTILs observed with the combination opens the possibility of studying this combination with immunotherapy. Further investigation comparing these biological results with other metronomic schedules or drug combinations is warranted.This study was supported by a grant from Pierre-Fabre. Pierre-Fabre had no role in the management of this trial. The decisions and responsibilities of this trial were all under the sponsor: SOLTI Group

    Nonadditivity of Bipartite Distillable Entanglement follows from Conjecture on Bound Entangled Werner States

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    Assuming the validity of a conjecture in quant-ph/9910026 and quant-ph/9910022 we show that the distillable entanglement for two bipartite states, each of which individually has zero distillable entanglement, can be nonzero. We show that this also implies that the distillable entanglement is not a convex function. Our example consists of the tensor product of a bound entangled state based on an unextendible product basis with a Werner state which lies in the class of conjectured undistillable states.Comment: 4 pages RevTex, 1 figure, to appear in Phys. Rev. Lett. Title changed and small paragraph adde

    Local versus non-local information in quantum information theory: formalism and phenomena

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    In spite of many results in quantum information theory, the complex nature of compound systems is far from being clear. In general the information is a mixture of local, and non-local ("quantum") information. To make this point more clear, we develop and investigate the quantum information processing paradigm in which parties sharing a multipartite state distill local information. The amount of information which is lost because the parties must use a classical communication channel is the deficit. This scheme can be viewed as complementary to the notion of distilling entanglement. After reviewing the paradigm, we show that the upper bound for the deficit is given by the relative entropy distance to so-called psuedo-classically correlated states; the lower bound is the relative entropy of entanglement. This implies, in particular, that any entangled state is informationally nonlocal i.e. has nonzero deficit. We also apply the paradigm to defining the thermodynamical cost of erasing entanglement. We show the cost is bounded from below by relative entropy of entanglement. We demonstrate the existence of several other non-local phenomena. For example,we prove the existence of a form of non-locality without entanglement and with distinguishability. We analyze the deficit for several classes of multipartite pure states and obtain that in contrast to the GHZ state, the Aharonov state is extremely nonlocal (and in fact can be thought of as quasi-nonlocalisable). We also show that there do not exist states, for which the deficit is strictly equal to the whole informational content (bound local information). We then discuss complementary features of information in distributed quantum systems. Finally we discuss the physical and theoretical meaning of the results and pose many open questions.Comment: 35 pages in two column, 4 figure
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