1,360 research outputs found
Noble gas geochemistry in seismic (Umbria, Italy) and volcanic (Grand Comore Island, Indian Ocean) regions: New methodologies and implications
The noble gases are among the most powerful geochemical tools in different geological settings. For this reason, they represent one of the most valuable tracers of geochemical processes whose variations can be straightforwardly ascribed to magmatic/crustal dynamics. In this dissertation, noble gas (He, Ne, Ar) geochemistry applied in both seismic and volcanic regions are presented.
The PhD research has firstly been devoted to the test on the field of an auto-sampler for high-frequency collection of the water samples in order to be analysed for their dissolved noble gases. Then, I developed a lab-based methodology for the in-vacuum extraction of noble gases from waters collected in the copper tubes. The auto-sampler, named S.P.A.R.T.A.H. (Syringe Pump Apparatus for the Retrieval and Temporal Analysis of Helium), has been installed for a period of 2 months in a seismically active sector in the Umbria region (central Apennines, Italy), and collected fluids from a natural spring for the entire duration of the deployment with the aim of obtaining short-term noble gas data. The proper functioning and successful operation of the extraction system has been tested and verified in the Noble Gas Laboratory at the Istituto Nazionale di Geofisica e Vulcanologia (INGV) of Palermo.
In second part of the PhD research, I focused my attention on the high-flux CO2–rich gas emissions localized in the central sector of the Apennines. The sampled gases have been analyzed for their chemical and isotopic composition (e.g., noble gases). Then, I developed a background geochemical model of fluid circulation and secondary chemical processes that occur during the transfer of fluid in the shallow crustal layers. Moreover I recognize a progressive northward decrease of the mantle-derived He degassing at regional scale along the Apennines. Furthermore, this study highlighted that the variable compositions of the gas manifestations discharged across the Umbria region can be best interpreted as a result of the combination of two different chemical processes which are not mutually exclusive: 1) a mixing between a magmatic end-member (VCVD) and a shallow-sedimentary sources, and 2) solubility-controlled fractionation mechanisms taking place upon interaction with shallow subsurface waters.
Finally, the project has been also addressed to the investigation of noble gases in fluids of an active volcanic system, Grande Comore Island (Indian Ocean). The noble gases (He, Ne, Ar) from fluid inclusions in peridotite mantle xenoliths coupled to radiogenic components (Sr, Nd, Pb) have been analysed to resolve the mantle source feeding the volcanism. Here I recognized a MORB-type mantle reservoir. In particular, the 3He/4He isotope compositions (up to 7.3Ra) fall in a range that overlaps the MORB mantle signature and the SCLM. The 20Ne/22Ne, 21Ne/22Ne and 40Ar/36Ar isotope ratios plot along a mixing between air and a typical MORB-type reservoir. The Sr-Nd-Pb isotope systematics shows a mixing line between Depleted MORB and Enriched Mantle reservoirs, but for two samples whose higher Sr isotope signatures point towards an EM2 source, showing isotopic similarities with carbonatite rocks from the East African Rift System and central-northern Madagascar alkaline rocks
The stable set polytope of claw-free graphs with stability number at least four. I. Fuzzy antihat graphs are W-perfect
Abstract Fuzzy antihat graphs are graphs obtained as 2-clique-bond compositions of fuzzy line graphs with three different types of three-cliqued graphs. By the decomposition theorem of Chudnovsky and Seymour [2] , fuzzy antihat graphs form a large subclass of claw-free, not quasi-line graphs with stability number at least four and with no 1-joins. A graph is W -perfect if its stable set polytope is described by: nonnegativity, rank, and lifted 5-wheel inequalities. By exploiting the polyhedral properties of the 2-clique-bond composition, we prove that fuzzy antihat graphs are W -perfect and we move a crucial step towards the solution of the longstanding open question of finding an explicit linear description of the stable set polytope of claw-free graphs
Retreat of Mediterranean Glaciers since the Little Ice Age: Case Study of Ghiacciaio del Calderone, Central Apennines, Italy
Ghiacciaio del Calderone is the only glacier in the Italian Apennines and the southernmost glacier in Europe. In this paper, the authors present a tentative synthesis of the evolution of the glacier, with a particular focus on evaluating the variations in area and thickness ranging from the end of the Little Ice Age to the present. The analysis was performed in a GIS environment, using available data for georeferation (mainly from recent topographic maps) and for the reconstruction (from historical documents and old topographic maps) of the variations of the glacier in the last two centuries. The resulting values, reconstructed and/or calculated, covering the period since the end of the Little Ice Age, of about 36 m of ice thickness and of about 59,000 m2 of ice surface area represent the glacier loss by 1990
Food seeking in spite of harmful consequences is under prefrontal cortical noradrenergic control
<p>Abstract</p> <p>Background</p> <p>Eating disorders are multifactorial psychiatric disorders. Chronic stressful experiences and caloric restriction are the most powerful triggers of eating disorders in human and animals. Although compulsive behavior is considered to characterize pathological excessive food intake, to our knowledge, no evidence has been reported of continued food seeking/intake despite its possible harmful consequences, an index of compulsive behavior. Brain monoamine transmission is considered to have a key role in vulnerability to eating disorders, and norepinephrine in medial prefrontal cortex has been shown to be critical for food-related motivated behavior.</p> <p>Here, using a new paradigm of conditioned suppression, we investigated whether the ability of a foot-shock-paired conditioned stimulus to suppress chocolate-seeking behavior was reversed by previous exposure to a food restriction experience, thus modeling food seeking in spite of harmful consequences in mice. Moreover, we assessed the effects of selective norepinephrine inactivation in medial prefrontal cortex on conditioned suppression test in stressed and caloric restricted mice.</p> <p>Results</p> <p>While Control (non food deprived) animals showed a profound conditioned suppression of chocolate seeking during presentation of conditioned stimulus, previously food restricted animals showed food seeking/intake despite its possible harmful consequences. Moreover, food seeking in spite of harmful consequences was prevented by selective norepinephrine inactivation, thus showing that prefrontal cortical norepinephrine is critical also for maladaptive food-related behavior.</p> <p>Conclusions</p> <p>These findings indicate that adaptive food seeking/intake can be transformed into maladaptive behaviors and point to "top-down" influence on eating disturbances and to new targets for therapy of aberrant eating behaviors.</p
CALIDAD DE ATENCIÓN QUE BRINDA LA ENFERMERA SEGÚN PERCEPCIÓN DE USUARIOS CON HIPERTENSIÓN ARTERIAL DEL CENTRO DE SALUD PERÚ COREA, HUÁNUCO 2018
Objetivo general: Determinar la calidad de atención que brinda la enfermera según percepción de los usuarios con hipertensión arterial que acuden al Centro de Salud Perú Corea, Huánuco 2018. Métodos: Se realizó un estudio descriptivo simple en 135 usuarios con hipertensión arterial utilizando una escala de calidad de atención en la recolección de los datos. El análisis inferencial se realizó con la prueba del Chi Cuadrado de Comparación de Frecuencias para una sola muestra con un nivel de significancia estadística p≤0,05. Resultados: En general, 46,7% de usuarios con hipertensión arterial percibieron que la atención que brinda la enfermera fue de regular calidad. En cuanto a la evaluación por dimensiones, se encontró que en la dimensión cuidado humano, 46,7% consideraron que la atención fue de regular calidad; en la dimensión técnica científica, 44,5% refirieron que la atención fue de regular calidad; en la dimensión entorno físico, 47,4% señalaron que la atención fue de regular calidad; y finalmente, en la dimensión entorno relaciones interpersonales, 45,9% percibieron que la atención que brinda la enfermera fue de regular calidad. En consecuencia, se evidenció que predominaron los usuarios que percibieron que la calidad de atención que brinda la enfermera fue de regular calidad (p ≤ 0,000); y en todas las dimensiones analizadas se hallaron diferencias significativas en las frecuencias observadas (p ≤ 0,05). Conclusiones: Los usuarios con hipertensión arterial percibieron que la atención que brinda la enfermera fue de regular calidad.Tesi
The possible prognostic role of histone deacetylase and transforming growth factor β/Smad signaling in high grade gliomas treated by radio-chemotherapy: a preliminary immunohistochemical study
Glioblastoma (GBM) is the most common and aggressive tumor of the central nervous system. Unfortunately, patients affected by this disease have a very poor prognosis, due to high level of invasiveness and resistance to standard therapies. Although the molecular profile of GBM has been extensively investigated, the events responsible for its pathogenesis and progression remain largely unknown. Histone Deacetylases (HDAC) dependent epigenetic modifications and transforming growth factor (TGF)-β/Smad pathway seem to play an important role in GBM tumorigenesis, resistance to common therapies and poor clinical outcome. The aim of this study was to evaluate the involvement and the possible interaction between these two molecular cascades in the pathogenesis and prognosis of GBM. Immunohistochemistry (IHC) was performed on microdissected GBM samples, collected from 14 patients (6 men and 8 women) ranging in age from 43 to 74 years. The patients were previously divided, on the basis of their overall survival (OS), into two groups: short and long OS. Patients with poor prognosis showed hyperexpression of HDAC4 and HDAC6, an activation of the TGF-β/Smad pathway, with high levels of IL-13, Smad2, PDGF and MMP3 expression, compared to the long survivors. The short OS group exhibits a decrease in Smad 7 expression and also low levels of p21 immunostaining, which represents a common target of the two pathways. The IHC data was confirmed by quantitative analysis and Immunoblotting. Our preliminary results suggest that both HDAC4 and HDAC6 together with the TGF-β/Smad pathway may be involved in progression of GBM and this cross talking could be a useful prognostic marker in this deadly disease
Atributos da armadilha influenciam captura de Diabrotica speciosa (Coleoptera: Chrysomelidae) em feijoeiro
Refinamentos em caraterísticas de armadilhas podem incrementar sua habilidade para monitorar e capturar em massa os insetos. Experimentos foram conduzidos em lavoura de feijoeiro para verificar as respostas de Diabrotica speciosa (Germar) a algumas características de armadilhas. Armadilhas de copos plástico (750 mL) amarelo ouro capturaram mais fêmeas e machos de D. speciosa do que transparentes. Placas de Petri com pedaços de cenoura, com pó seco de purungo, Lagenaria vulgaris L. (fonte de cucurbitacina - 0,28%) capturaram mais insetos do que placas com somente cenoura. Liberadores para o atraente floral 1,4-dimetoxibenzeno foram também comparados. Liberador de septo de borracha atraiu mais insetos do que o controle (flocos dentais saturados com acetona). Capturas nos tratamentos com liberadores de floco dental, matriz borato e absorvente higiênico foram intermediárias mas não diferiram da testemunha e septo. Modelo de armadilha de garrafa (2000 mL) furada capturou mais insetos do que armadilha vazada ("janelas") (ambas contendo pó seco de purungo) na maioria das avaliações, dos dois até os dez dias após a instalação das armadilhas no campo. Armadilhas com inseticida carbaryl capturaram mais insetos do que armadilhas sem, nos intervalos de 2-4 e 9-10 dias após a instalação das armadilhas no campo. Nos períodos restantes (0-2, 4-6- e 6-8 dias), diferenças não foram detectadas. Armadilhas com 1,4-dimetoxibenzeno capturaram mais insetos do que armadilhas sem o volátil (avaliações a cada dois dias dos dois aos dez dias após a instalação no campo). Finalmente, quantidades similares de insetos foram capturadas usando armadilhas de garrafa pet (2000 mL): vazadas ("janelas"), furadas (ambas com cucurbitacina) e adesivas quando estas foram iscadas com o atraente floral.Refinements in trap characteristics may improve ability to monitor and mass-trap beetles. Field assays were conducted in common bean fields to assess responses of Diabrotica speciosa (Germar) to some trap characteristics. Golden yellow plastic cups (750 mL) traps caught more D. speciosa females and males than did clear traps. Carrot slices in Petri dishes baited with Lagenaria vulagaris L. powder (cucurbitacin source - 0.28%) caught more beetles than did dishes with carrot alone. Dispensers for the floral volatile attractant 1,4-dimethoxybenze were also compared. Rubber septa dispenser attracted more beetles than did control (dental wicks saturated with acetone). Captures on dental wick, starch matrix and feminine pad dispensers were intermediate and did not differ from those on rubber septa and unbaited controls. Perforated bottle traps (2000 mL), when baited with the floral attractant, caught more beetles than did window bottle traps (both traps contained L. vulgaris powder) in most assessments done from two to ten days after trap placement in the field. Traps with the insecticide carbaryl captured more beetles than did traps without it, 2-4 and 8-10 days after trap placement in the field, but not in the remaining periods (0-2, 4-6 and 6-8 days). Traps baited with 1,4-dimethoxybenzene captured more beetles than did the unbaited ones in all assessments (each other day from two to ten days after trap placement in the field). Finally, similar amounts of beetles were captured using plastic bottle traps (2000 mL): perforated, window (both with cucurbitacin) and sticky (without cucurbitacin) traps, when were baited with the floral attractant
Enhancement of radiosensitivity by the novel anticancer quinolone derivative vosaroxin in preclinical glioblastoma models
Purpose: Glioblastoma multiforme (GBM) is the most aggressive brain tumor. The activity of vosaroxin, a first-in-class anticancer quinolone derivative that intercalates DNA and inhibits topoisomerase II, was investigated in GBM preclinical models as a single agent and combined with radiotherapy (RT). Results: Vosaroxin showed antitumor activity in clonogenic survival assays, with IC50 of 10-100 nM, and demonstrated radiosensitization. Combined treatments exhibited significantly higher γH2Ax levels compared with controls. In xenograft models, vosaroxin reduced tumor growth and showed enhanced activity with RT; vosaroxin/RT combined was more effective than temozolomide/RT. Vosaroxin/ RT triggered rapid and massive cell death with characteristics of necrosis. A minor proportion of treated cells underwent caspase-dependent apoptosis, in agreement with in vitro results. Vosaroxin/RT inhibited RT-induced autophagy, increasing necrosis. This was associated with increased recruitment of granulocytes, monocytes, and undifferentiated bone marrow-derived lymphoid cells. Pharmacokinetic analyses revealed adequate blood-brain penetration of vosaroxin. Vosaroxin/RT increased disease-free survival (DFS) and overall survival (OS) significantly compared with RT, vosaroxin alone, temozolomide, and temozolomide/RT in the U251-luciferase orthotopic model. Materials and Methods: Cellular, molecular, and antiproliferative effects of vosaroxin alone or combined with RT were evaluated in 13 GBM cell lines. Tumor growth delay was determined in U87MG, U251, and T98G xenograft mouse models. (DFS) and (OS) were assessed in orthotopic intrabrain models using luciferasetransfected U251 cells by bioluminescence and magnetic resonance imaging. Conclusions: Vosaroxin demonstrated significant activity in vitro and in vivo in GBM models, and showed additive/synergistic activity when combined with RT in O6- methylguanine methyltransferase-negative and -positive cell lines
Plano de negócio para verificar a viabilidade de um bar temático esportivo em Florianópolis
TCC (graduação) - Universidade Federal de Santa Catarina, Centro Sócio Econômico, Curso de Administração.Este plano de negócio visa coletar e analisar as informações necessárias para verificar a viabilidade de abertura de um bar temático esportivo em Florianópolis, evidenciando as características que diferenciariam o empreendimento das demais ofertas do segmento. A cidade conta com cerca de 480.000 habitantes, segundo dados do IBGE (Instituto Brasileiro de Geografia e Estatística) de 2016, e uma ampla oferta de bares e similares, porém em nenhum destes há a presença da tematização esportiva nos moldes pretendidos para o negócio em questão. O trabalho propõe-se a examinar e contextualizar o setor em que o negócio se encaixaria, além de verificar os aspectos do ambiente em que o bar seria instalado, investigando a conjuntura atual do cenário e como atuam seus agentes. Além disso, segue as especificações necessárias para elaboração de um plano de negócio, contendo descrição de processos e operações, detalhamentos de custos e projeções financeiras, análise de indicadores e demais aspectos, sendo constatado ao seu final de que com o investimento necessário e utilizando a estratégia adequada o empreendimento tem boas possibilidades de gerar significante retorno.This business plan aims to collect and analyze the information needed to verify the feasibility of opening a sports themed bar in Florianópolis, highlighting the characteristics that would constrast the venture from the other offers in the segment. The city has about 480,000 inhabitants, according to data from the Instituto Brasileiro de Geografia e Estatística (IBGE) from 2016, and a wide range of bars and similars, but in none of these there is the presence of sports theme in the molds intended for the business in question. The work proposes to examine and contextualize the sector in which the business would fit, as well as to verify the aspects of the environment in which the bar would be installed, investigating the current conjuncture of the scenario and how its agents act. In addition, it follows the specifications required for the preparation of a business plan, containing a description of processes and operations, detailing costs and financial projections, analysis of indicators and other aspects, being verified to its end that with the necessary investment and using the appropriate strategy the enterprise has good possibilities to generate significant return
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