950 resultados para Problematic
Resumo:
Improvements to the routine methods for the determination of actual acidity in suspension for acid sulfate soils (ASS) are introduced. The titratable sulfidic acidity (TSA) results using an improved peroxide-based method were compared with the theoretical acidity predicted by the chromium reducible sulfur method for 9 acid sulfate soils. The regression between these 2 measures of sulfidic acidity was highly significant, the slope of the regression line not significantly different from unity (P = 0.05) and the intercept not significantly different from zero. This contrasts with results of other workers using earlier peroxide oxidation methods, where TSA substantially underestimated the theoretical acidity predicted by reduced inorganic sulfur analysis. Comparison was made between the 2 principal measurements from the improved peroxide method (TSA and S-POS), with S-POS converted to theoretical sulfidic acidity to allow comparison. The relationship between these 2 measurements was highly significant. The effects of titration in suspension, as well as raising titration end points to pH 6.5, were investigated, principally with respect to the titratable actual acidity (TAA) result. TAA results obtained by KCl extraction were compared with those obtained using BaCl2, MgCl2, and water extraction. TAA in 1 M KCl suspensions titrated to pH 6.5 agreed well with titratable actual acidity measured using the 25-h extraction approach of the Lin et al. (2000a) BaCl2 method. Both BaCl2 and KCl solutions were ineffective at fully recovering acidity from synthetic jarosite without repeated extraction and titration. The application of correction factors for the estimation of total actual acidity in ASS is not supported by the results of this investigation. Acid sulfate soils that contain substantial quantities of jarosite or other acid-producing but relatively insoluble sulfate minerals continue to prove problematic to chemically analyse; however, an approach for estimating this component is discussed.
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Thomas & Tow's evaluation of the utility of human security is an important contribution to an ongoing debate about what security is and for whom security should be provided. In particular, the authors' engagement with the human security agenda is important given the centrality of this approach to recent attempts to rethink security. This article argues, however, that Thomas & Tow's approach to the human security agenda is problematic for two central reasons. First, their attempt to narrow security to make this approach amenable to state policymakers risks reifying the sources of insecurity for individuals everywhere. Second, the conception of human security they put forward appears largely inconsistent with the normative concerns inherent in the human security agenda.
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Background: Presently the surgical approach to the adrenal gland is in a state of flux. While the traditional approach to the adrenal gland has been the open transabdominal technique, more recently laparoscopic approaches, particularly via the transabdominal route, have increasingly been utilized. However, laparoscopic intervention for the adrenal gland can be problematic in certain circumstances, particularly for large adrenal masses and in instances of adrenal malignancies. Methods: In this report we describe the use of hand-assisted laparoscopic adrenalectomy as an alternative minimal invasive surgical approach to the adrenal gland. Hand-assisted laparoscopic adrenalectomy using the HandPort system (Smith & Nephew, Sydney, Australia) was undertaken in three patients requiring adrenalectomy for mass lesions including one patient with Conn's syndrome. Results: In all three cases, surgery proceeded promptly and uneventfully. In the present paper, the details of the technique of hand-assisted adrenalectomy are described. This is the first report in the world literature of this new technique for the adrenal gland. Conclusions: Hand-assisted laparoscopic adrenalectomy is an easily performed technique, which can be completed within a short operative time span and which has the advantage of providing intraoperative tactile localization for the adrenal gland. It may be particularly applicable for large adrenal tumours, yet only involves the performance of a small abdominal incision. Postoperative recovery is comparable with that reported for the laparoscopic-only technique. Hand-assisted adrenalectomy is a new technique which has great potential and which warrants further evaluation.
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We describe remarkable success in controlling dengue vectors, Aedes aegypti (L.) and Aedes albopictus (Skuse), in 6 communes with 11,675 households and 49,647 people in the northern provinces of Haiphong, Hung Yen, and Nam Dinh in Vietnam. The communes were selected for high-frequency use of large outdoor concrete tanks and wells. These were found to be the source of 49.6-98.4% of Ae. aegypti larvae, which were amenable to treatment with local Mesocyclops, mainly M. woutersi Van der Velde, M. aspericornis (Daday) and M. thermocyclopoides Harada. Knowledge, attitude, and practice surveys were performed to determine whether the communities viewed dengue and dengue hemorrhagic fever as a serious health threat; to determine their knowledge of the etiology, attitudes, and practices regarding control methods including Mesocyclops; and to determine their receptivity to various information methods. On the basis of the knowledge, attitude, and practice data, the community-based dengue control program comprised a system of local leaders, health volunteer teachers, and schoolchildren, supported by health professionals. Recycling of discards for economic gain was enhanced, where appropriate, and this, plus 37 clean-up campaigns, removed small containers unsuitable for Mesocyclops treatment. A previously successful eradication at Phan Boi village (Hung Yen province) was extended to 7 other villages forming Di Su commune (1,750 households) in the current study. Complete control was also achieved in Nghia Hiep (Hung Yen province) and in Xuan Phong (Nam Dinh province); control efficacy was greater than or equal to 99.7% in the other 3 communes (Lac Vien in Haiphong, Nghia Dong, and Xuan Kien in Nam Dinh). Although tanks and wells were the key container types of Ae. aegypti productivity, discarded materials were the source of 51% of the standing crop of Ae. albopictus. Aedes albopictus larvae were eliminated from the 3 Nam Dinh communes, and 86-98% control was achieved in the other 3 communes. Variable dengue attack rates made the clinical and serological comparison of control and untreated communes problematic, but these data indicate that clinical surveillance by itself is inadequate to monitor dengue transmission.
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Much is known about those aspects of tuna health which can be studied in wild populations, e.g. helminth parasites. However, because aquaculture of these species is in its infancy, knowledge of microbial, nutritional and environmental diseases is limited. This review is an attempt to bring together the available information on those diseases of Thunnus spp. which cause significant morbidity, mortality or economic loss. In doing so it has become clear that much more research needs to be undertaken on the physiology of the species (southern, northern and Pacific bluefin tuna) currently used in aquaculture in order for the pathogenesis of some conditions to be properly understood. Attempts at hatchery culture of Pacific bluefin tuna has indicated that Thunnus spp. will be problematic to hatch and propagate.
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The most widely used method for predicting the onset of continuous caving is Laubscher's caving chart. A detailed examination of this method was undertaken which concluded that it had limitations which may impact on results, particularly when dealing with stronger rock masses that are outside current experience. These limitations relate to inadequate guidelines for adjustment factors to rock mass rating (RMR), concerns about the position on the chart of critical case history data, undocumented changes to the method and an inadequate number of data points to be confident of stability boundaries. A review was undertaken on the application and reliability of a numerical method of assessing cavability. The review highlighted a number of issues, which at this stage, make numerical continuum methods problematic for predicting cavability. This is in particular reference to sensitivity to input parameters that are difficult to determine accurately and mesh dependency. An extended version of the Mathews method for open stope design was developed as an alternative method of predicting the onset of continuous caving. A number of caving case histories were collected and analyzed and a caving boundary delineated statistically on the Mathews stability graph. The definition of the caving boundary was aided by the existence of a large and wide-ranging stability database from non-caving mines. A caving rate model was extrapolated from the extended Mathews stability graph but could only be partially validated due to a lack of reliable data.
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A high definition, finite difference time domain (HD-FDTD) method is presented in this paper. This new method allows the FDTD method to be efficiently applied over a very large frequency range including low frequencies, which are problematic for conventional FDTD methods. In the method, no alterations to the properties of either the source or the transmission media are required. The method is essentially frequency independent and has been verified against analytical solutions within the frequency range 50 Hz-1 GHz. As an example of the lower frequency range, the method has been applied to the problem of induced eddy currents in the human body resulting from the pulsed magnetic field gradients of an MRI system. The new method only requires approximately 0.3% of the source period to obtain an accurate solution. (C) 2003 Elsevier Science Inc. All rights reserved.
Resumo:
Three Herpes Simplex Virus LightCycler polymerase chain reaction assays were compared for the detection of herpes simplex virus in 48 swab specimens. The assays comprised of one in-house assay and two commercial kits: the Artus HSV LC RealArt PCR kit and the Roche LightCycler HSV 1/2 Detection kit. On the whole, the three assays had comparable sensitivities. However, differentiation of herpes simplex virus types 1 and 2 by melting curve analysis was problematic in all assays. Overall, the results highlight the limitations of typing herpes simplex virus by melting curve analysis.
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A proportion of melanoma,prone individuals in both familial and non,familial contexts has been shown to carry inactivating mutations in either CDKN2A or, rarely, CDK4. CDKN2A is a complex locus that encodes two unrelated proteins from alternately spliced transcripts that are read in different frames. The alpha transcript (exons 1a, 2, and 3) produces the p16INK4A cyclin-dependent kinase inhibitor, while the beta transcript (exons 1beta and 2) is translated as p14ARF, a stabilizing factor of p53 levels through binding to MDM2. Mutations in exon 2 can impair both polypeptides and insertions and deletions in exons 1alpha, 1beta, and 2, which can theoretically generate p16INK4A,p14ARF fusion proteins. No online database currently takes into account all the consequences of these genotypes, a situation compounded by some problematic previous annotations of CDKN2A related sequences and descriptions of their mutations. As an initiative of the international Melanoma Genetics Consortium, we have therefore established a database of germline variants observed in all loci implicated in familial melanoma susceptibility. Such a comprehensive, publicly accessible database is an essential foundation for research on melanoma susceptibility and its clinical application. Our database serves two types of data as defined by HUGO. The core dataset includes the nucleotide variants on the genomic and transcript levels, amino acid variants, and citation. The ancillary dataset includes keyword description of events at the transcription and translation levels and epidemiological data. The application that handles users' queries was designed in the model,view. controller architecture and was implemented in Java. The object-relational database schema was deduced using functional dependency analysis. We hereby present our first functional prototype of eMelanoBase. The service is accessible via the URL www.wmi.usyd.e, du.au:8080/melanoma.html.
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Increased professionalism in rugby has elicited rapid changes in the fitness profile of elite players. Recent research, focusing on the physiological and anthropometrical characteristics of rugby players, and the demands of competition are reviewed. The paucity of research on contemporary elite rugby players is highlighted, along with the need for standardised testing protocols. Recent data reinforce the pronounced differences in the anthropometric and physical characteristics of the forwards and backs. Forwards are typically heavier, taller, and have a greater proportion of body fat than backs. These characteristics are changing, with forwards developing greater total mass and higher muscularity. The forwards demonstrate superior absolute aerobic and anaerobic power, and Muscular strength. Results favour the backs when body mass is taken into account. The scaling of results to body mass can be problematic and future investigations should present results using power function ratios. Recommended tests for elite players include body mass and skinfolds, vertical jump, speed, and the multi-stage shuttle run. Repeat sprint testing is a possible avenue for more specific evaluation of players. During competition, high-intensity efforts are often followed by periods of incomplete recovery. The total work over the duration of a game is lower in the backs compared with the forwards; forwards spend greater time in physical contact with the opposition while the backs spend more time in free running, allowing them to cover greater distances. The intense efforts undertaken by rugby players place considerable stress on anaerobic energy sources, while the aerobic system provides energy during repeated efforts and for recovery. Training should focus on repeated brief high-intensity efforts with short rest intervals to condition players to the demands of the game. Training for the forwards should emphasise the higher work rates of the game, while extended rest periods can be provided to the backs. Players should not only be prepared for the demands of competition, but also the stress of travel and extreme environmental conditions. The greater professionalism of rugby union has increased scientific research in the sport; however, there is scope for significant refinement of investigations on the physiological demands of the game, and sports-specific testing procedures.
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Two methods were compared for determining the concentration of penetrative biomass during growth of Rhizopus oligosporus on an artificial solid substrate consisting of an inert gel and starch as the sole source of carbon and energy. The first method was based on the use of a hand microtome to make sections of approximately 0.2- to 0.4-mm thickness parallel to the substrate surface and the determination of the glucosamine content in each slice. Use of glucosamine measurements to estimate biomass concentrations was shown to be problematic due to the large variations in glucosamine content with mycelial age. The second method was a novel method based on the use of confocal scanning laser microscopy to estimate the fractional volume occupied by the biomass. Although it is not simple to translate fractional volumes into dry weights of hyphae due to the lack of experimentally determined conversion factors, measurement of the fractional volumes in themselves is useful for characterizing fungal penetration into the substrate. Growth of penetrative biomass in the artificial model substrate showed two forms of growth with an indistinct mass in the region close to the substrate surface and a few hyphae penetrating perpendicularly to the surface in regions further away from the substrate surface. The biomass profiles against depth obtained from the confocal microscopy showed two linear regions on log-linear plots, which are possibly related to different oxygen availability at different depths within the substrate. Confocal microscopy has the potential to be a powerful tool in the investigation of fungal growth mechanisms in solid-state fermentation. (C) 2003 Wiley Periodicals, Inc.
Resumo:
Tendo como pano de fundo a natureza problem??tica das tentativas de reformar os sistemas nacionais de presta????o de servi??os sociais e de sa??de, este artigo busca fazer uma revis??o da l??gica da Nova Gest??o P??blica (NGP) no setor de servi??os de sa??de. Ap??s contextualizar as diversas abordagens da capacita????o em pol??ticas sociais e as tr??s gera????es de reformas do setor p??blico, faz um exame das reformas aplicadas na presta????o de servi??os de sa??de, sugerindo estrat??gias que levem em conta a capacidade. O artigo finaliza com uma discuss??o sobre o papel da governan??a na pol??tica social e no desenvolvimento.
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Este paper defende duas id??ias. A primeira, ?? apresentar os diferentes processos da reforma do Estado mexicano, analisados sob as prioridades diversas no decorrer do tempo. As reformas econ??mica, pol??tica, social e administrativa tiveram prioridades e objetivos divergentes. A reforma econ??mica foi sistem??tica e congruente, a pol??tica foi defensiva e pouco abrangente, e a social foi problem??tica e confusa. A reforma administrativa foi, comparativamente, limitada. Uma proposta para desenvolver um sistema administrativo respons??vel pelo servi??o p??blico foi postergada nos ??ltimos 12 anos at?? que, em maio de 1997, finalmente a atual administra????o prop??s um programa de moderniza????o. A segunda id??ia ?? que, mesmo que a atual administra????o tenha a inten????o de desenvolver um novo sistema de accountability e um plano de carreira para o servi??o p??blico, parece plaus??vel que a tradicional pol??tica de controle, atrav??s da estrutura administrativa, possa ser prejudicada se essas propostas realmente reduzirem o poder discricion??rio dos altos cargos p??blicos e submeterem reservas p??blicas a um esquema de controle social mais aberto e formal. Logo, ?? poss??vel dizer que a alternativa escolhida pelos reformistas foi usar uma abordagem gerenciadora, onde a melhoria dos procedimentos e a implementa????o de algumas t??cnicas administrativas avan??adas substituem, pelo menos at?? agora, uma transforma????o mais profunda da estrutura administrativa. Uma estrat??gia de gerenciamento permite, pelo menos at?? o momento, a melhoria dos servi??os atrav??s do aumento da participa????o de servidores p??blicos, sem prejudicar a atual administra????o, como um instrumento para implementar diferentes agendas pol??ticas usando recursos p??blicos. Nosso argumento ?? que, como o programa de moderniza????o est?? sendo implantado, ?? importante estudar minuciosamente as possibilidades de se implementar a reforma do servi??o p??blico e melhorar a responsabilidade do sistema, dada a particular rela????o que existe entre a administra????o p??blica e o sistema pol??tico no M??xico.
Resumo:
Desenvolve e aplica o Suporte de Identifica????o e Enfrentamento de Situa????es Problema (Siesp). Sob o ponto de vista descritivo, esse recurso busca ampliar e explicitar informa????es sobre situa????es problema existentes nas organiza????es, mas que n??o s??o facilmente percebidas. Sob o ponto de vista prescritivo, esse Suporte baseado na Metodologia de Sistemas Flex??veis (MSF) busca ampliar e explicitar conhecimentos a serem aproveitados para converter decis??es bem informadas em a????es oportunas de confronto da situa????o antes enquadrada como problem??tica, porque ela causa ou tem potencial para causar consequ??ncias indesej??veis. O contexto focalizado ?? o sistema de informa????o da Ag??ncia Nacional de Energia El??trica (ANEEL). O resultado desse trabalho ?? relatado neste artigo. Novos trabalhos poder??o ser realizados com o prop??sito de aplicar o SIESP em outras realidades organizacionais, com vistas a consolid??-lo como recurso ??til destinado a ampliar, explicitar e aproveitar conhecimentos.
Resumo:
O presente trabalho aborda, sob uma perspectiva analítica e crítica da Geografia, a temática relacionada ao lazer na cidade contemporânea, tendo como problemática a implantação desigual dos equipamentos públicos de lazer na cidade de Vitória-ES. A discussão do tema está associada ao lazer como um direito constitucional do cidadão, revelando de que maneira o Poder Público corrobora para a espacialização desigual dos equipamentos de lazer na cidade estudada. A discussão surgiu em torno da constatação de que Vitória-ES é uma cidade geograficamente dividida pelo Maciço Central, o que gera espaços diferenciados, como a orla Nordeste, rica e equipada dos mais diversos equipamentos de lazer e a orla Noroeste, voltada para a baía de Vitória e para o manguezal, marcada por grandes disparidades humanas, econômicas e sociais. Observou-se que, durante muitas décadas, o Poder Público esteve ausente na promoção de equipamentos públicos de lazer na orla Noroeste de Vitória, o que gerou ambientes diferenciados na cidade. Enquanto isso, a orla Nordeste passou por um intenso processo de promoção de equipamentos públicos, dos mais requintados, promotores de um valorização do solo local e da melhoria da qualidade de vida para a população ali residente. Desse modo, a dissertação pretendeu investigar as políticas públicas que estiveram atreladas à promoção de equipamentos públicos de lazer em quatro bairros específicos: Grande Vitória, Nova Palestina, Maria Ortiz e Resistência, todos localizados na orla Noroeste de Vitória. A escolha pelos bairros se deu através da detecção de que dois deles (Maria Ortiz e Nova Palestina) receberam a implantação de equipamentos públicos de lazer, tendo suas orlas reurbanizadas e o outros dois (Grande Vitória e Resistência), até a presente data, aguardam pela chegada de infraestrutura urbana de todos os tipos, inclusive de lazer.