986 resultados para Assisted reproductive technologies


Relevância:

20.00% 20.00%

Publicador:

Resumo:

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.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In an overview of some of the central issues concerning the impact and effects of new technology in adolescence, this article questions the reality of the net generation before considering the interplay of new and old technologies, the internet as both communication and lifestyle resource, and newer technologies like text messaging and webcams.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

One of the most important advantages of database systems is that the underlying mathematics is rich enough to specify very complex operations with a small number of statements in the database language. This research covers an aspect of biological informatics that is the marriage of information technology and biology, involving the study of real-world phenomena using virtual plants derived from L-systems simulation. L-systems were introduced by Aristid Lindenmayer as a mathematical model of multicellular organisms. Not much consideration has been given to the problem of persistent storage for these simulations. Current procedures for querying data generated by L-systems for scientific experiments, simulations and measurements are also inadequate. To address these problems the research in this paper presents a generic process for data-modeling tools (L-DBM) between L-systems and database systems. This paper shows how L-system productions can be generically and automatically represented in database schemas and how a database can be populated from the L-system strings. This paper further describes the idea of pre-computing recursive structures in the data into derived attributes using compiler generation. A method to allow a correspondence between biologists' terms and compiler-generated terms in a biologist computing environment is supplied. Once the L-DBM gets any specific L-systems productions and its declarations, it can generate the specific schema for both simple correspondence terminology and also complex recursive structure data attributes and relationships.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Ethephon promotes fruit abscission and accelerates harvest of macadamia, Macadamia integrifolia (Proteaceae), but has limited use due to concerns that associated abscission of inner-canopy leaves may reduce subsequent yield and nut quality. Yield and quality were monitored for 2 years following ethephon application to both unshaken and mechanically shaken trees of the late-abscising cultivar, A16. Nut quality was not adversely affected in subsequent seasons, but effects on yield varied. In 3 of 6 experiments, ethephon reduced yield in the year after application. However, in 4 of the 6 experiments, 2 years of ethephon application greatly elevated yield in the third year. This was not a compensating recovery from low second-year yield, as third-year yield of trees that received only 1 ethephon treatment did not differ from yield of control trees. Ethephon-assisted harvest remains feasible for macadamia, although further work is warranted given the potential risks and considerable benefits for subsequent yield. Inner canopy defoliation, resulting from ethephon use, could represent a canopy management technique for dense-canopy fruit trees.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Novel nonthermal processes, such as high hydrostatic pressure (HHP), pulsed electric fields (PEFs), ionizing radiation and ultrasonication, are able to inactivate microorganisms at ambient or sublethal temperatures. Many of these processes require very high treatment intensities, however, to achieve adequate microbial destruction in low-acid foods. Combining nonthermal processes with conventional preservation methods enhances their antimicrobial effect so that lower process intensities can be used. Combining two or more nonthermal processes can also enhance microbial inactivation and allow the use of lower individual treatment intensities. For conventional preservation treatments, optimal microbial control is achieved through the hurdle concept, with synergistic effects resulting from different components of the microbial cell being targeted simultaneously. The mechanisms of inactivation by nonthermal processes are still unclear; thus, the bases of synergistic combinations remain speculative. This paper reviews literature on the antimicrobial efficiencies of nonthermal processes combined with conventional and novel nonthermal technologies. Where possible, the proposed mechanisms of synergy is mentioned. (C) 2003 Elsevier Science B.V. All rights reserved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A switch-mode assisted linear amplifier (SMALA) combining a linear (Class B) and a switch-mode (Class D) amplifier is presented. The usual single hysteretic controlled half-bridge current dumping stage is replaced by two parallel buck converter stages, in a parallel voltage controlled topology. These operate independently: one buck converter sources current to assist the upper Class B output device, and a complementary converter sinks current to assist the lower device. This topology lends itself to a novel control approach of a dead-band at low power levels where neither class D amplifier assists, allowing the class B amplifier to supply the load without interference, ensuring high fidelity. A 20 W implementation demonstrates 85% efficiency, with distortion below 0.08% measured across the full audio bandwidth at 15 W. The class D amplifier begins assisting at 2 W, and below this value, the distortion was below 0.03%. Complete circuitry is given, showing the simplicity of the additional class D amplifier and its corresponding control circuitry.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Low temperature during panicle development in rice increases spikelet sterility. This effect is exacerbated by high rates of nitrogen (N) application in the field. Spikelet sterility induced by low temperature and N fertilisation was examined in glasshouse experiments to clarify the mechanisms involved. In two glasshouse experiments, 12-h periods of low (18/13degreesC) and high (28/23degreesC) day/night temperatures were imposed over periods of 5-7 days during panicle development, to determine the effects of low temperature and N fertilisation on spikelet sterility. In one experiment, 50% sunlight was imposed together with low temperature to investigate the additive effects of reduced solar radiation and low temperature. The effect of increased tillering due to N fertilisation was examined by a tiller removal treatment in the same experiment. Pollen grain number and spikelet sterility were recorded at heading and harvest, respectively. Although there was no significant effect of low temperature on spikelet sterility in the absence of applied N, low temperature greatly increased spikelet sterility as a result of a reduction in the number of engorged pollen grains per anther in the presence of applied N. Spikelet sterility was strongly correlated with the number of engorged pollen grains per anther. Low temperature during very early ( late stage of spikelet differentiation-pollen mother cell stage) and peak ( second meiotic division stage-early stage of extine formation) microspore development caused a severe reduction in engorged pollen production mainly as a result of reduced total pollen production. Unlike low temperature, the effect of shading was rather small. The increased tillering due to application of high rates of N, increased both spikelet number per plant and spikelet sterility under low temperature conditions. The removal of tillers as they appeared reduced the number of total spikelets per plant and maintained a large number of engorged pollen grains per anther which, in turn, reduced spikelet sterility. The number of engorged pollen grains per anther determined the numbers of intercepted and germinated pollen grains on the stigma. It is concluded that N increased tillering and spikelet number per plant and this, in turn, reduced the number of engorged pollen grains per anther, leading into increased spikelet sterility under low temperature condition.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A identificação e a avaliação de crianças com desenvolvimento atípico configuram um processo muito importante para subsidiar as estratégias de ensino voltadas para a promoção do potencial de aprendizagem. O interesse em relação ao prognóstico de crianças com deficiência tem impulsionado o desenvolvimento de novas tecnologias e pesquisas relacionadas à avaliação, prevenção e intervenção. Nesse contexto, torna-se relevante verificar com instrumentos adequados indicadores linguísticos, cognitivos e comportamentais, para assim traçar metas a partir daquilo que as crianças podem aprender. Dessa forma, esta pesquisa teve por objetivo verificar se a avaliação assistida informatizada se apresenta como uma modalidade de diagnóstico mais prescritivo do desenvolvimento cognitivo, quando comparada à avaliação psicométrica, na aplicação em crianças com deficiência. Na modalidade assistida há ajuda do examinador para conduzir a criança a um melhor nível de desempenho cognitivo. Participaram 11 crianças que frequentam uma instituição de atendimento clínico, em saúde, para crianças com deficiência, na Grande Vitória. Na avaliação psicométrica foram utilizados a Escala de Maturidade Mental Colúmbia computadorizada – Colúmbiacomp e o Teste de Vocabulário por Imagens Peabody - TVIPcomp. Na avaliação assistida informatizada foram aplicadas três provas voltadas para as habilidades de classificação e raciocínio analógico: Exclusão de Objetos, Exclusão de Figuras Geométricas e Jogo de Analogia de Figuras, no ambiente informatizado SINDAPSI. Protocolos de registro de fatores afetivo-motivacionais e de operações cognitivas foram utilizados durante as tarefas assistidas. Na avaliação do comportamento, o Child Behavior Checklist – CBCL foi respondido pelas mães. Dados documentais e dos instrumentos foram submetidos à análise estatística descritiva para verificar o desempenho das crianças nas duas formas de avaliação informatizada (psicométrica e assistida). Nos testes psicométricos, 64% das crianças alcançaram índice “abaixo da média” no TVIPcomp, e 55% “médio-inferior” no Colúmbiacomp. Em relação ao perfil de desempenho cognitivo, na Prova de Exclusão de Objetos computadorizada 55% das crianças foram avaliadas como “não-mantenedoras”. Na Prova de Exclusão de Figuras Geométricas computadorizada 55% da amostra foi classificada no perfil “alto-escore”, e no Jogo de Analogias de Figuras computadorizado 45% apresentou o perfil “ganhador”. A amostra demonstrou níveis de dificuldade na realização dos testes,tanto na modalidade psicométrica quanto assistida. Contudo, o desempenho nos testes assistidos foi relativamente melhor, evidenciando que o grupo se beneficiou da mediação,implementada na fase de assistência, para melhorar as habilidades cognitivas. Além disso, a apresentação informatizada dos testes apresentou-se como fator motivador para a realização e persistência nas tarefas.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Body and testicular biometric parameters are very important for establishing reproductive patterns and, consequently, the development of protocols for assisted reproduction in different species. A direct correlation between the testis weight and the sperm population was observed in other studied species, because the testis size primarily reflects the total volume of the seminiferous tubule, its main component. The objective of this study was to determine the testicular volume parameters and correlate data from morphometry of testis and seminiferous tubules with body mass in six adult crab-eating foxes. The mean body weight of the crab-eating foxes in this study was 6.53 kg, with approximately 0.068% allocated to the testicular mass and 0.042% specifically to seminiferous tubules, which represented 87.5% of the testicular parenchyma. The albuginea comprised 12.5% of the testicular mass. The mean diameter of seminiferous tubules was 236 µm, and the mean thickness of the seminiferous epithelium was 62.9 µm. Values of tubular parameters indicate a sperm productivity close to those observed in previously studied carnivores.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

With the population ageing effect, the technological developments, and pressure to reduce the cost with healthcare, are reunited the conditions for the development of Ambient Assisted Living (AAL) solutions. This work is a revision of the current state of the art. Its aim is the characterization of the AAL solutions, within the AAL4ALL scope. Therefore, it is presented features, scenarios and projects, referring the limitations and the opportunities for the future developments of prototypes using high level information and technology in AAL environments. Moreover, it is presented guidelines of operation, exposing the conceptual approach, and the discussion and conclusion, which present recommendations and current AAL4ALL project positions in terms of concepts and technologies.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Developed societies are currently facing severe demographic changes: the world population is ageing at an unprecedented rate. This demographic trend will be also followed by an increase of people with physical limitations. New challenges are being raised to the traditional health care systems, not only in Portugal, but also in all other European states. There is an urgent need to find solutions that allow extending the time people can live in their preferred environment by increasing their autonomy, self-confidence and mobility. AAL4ALL is a project currently being developed in cooperation with 34 Portuguese interdisciplinary partners, from industry to academia, R&D and social disciplines, which employs a novel conceptual approach through the development of an ecosystem of products and services for Ambient Assisted Living (AAL) associated to a business model and validated through large scale trial. This paper presents a comparative perspective of the needs and attitudes towards technology of the AAL users and caregivers identified in the analysis of a set of three different surveys: a users survey targeted at the Portuguese seniors and pre-seniors; an informal caregivers survey targeted at the family, friends and neighbours who provide care without any financial compensation; and a formal caregivers survey targeted at physicians, nurses,psychologists, social workers, and direct-care workers providing care to elders. The first results indicate that AAL solutions must be affordable,user friendly and have a true perceived benefit to their users.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

According to the opinion of clinicians, emerging medical conditions can be timely detected by observing changes in the activities of daily living and/or in the physiological signals of a person. To accomplish such purpose, it is necessary to properly monitor both the person’s physiological signals as well as the home environment with sensing technology. Wireless sensor networks (WSNs) are a promising technology for this support. After receiving the data from the sensor nodes, a computer processes the data and extracts information to detect any abnormality. The computer runs algorithms that should have been previously developed and tested in real homes or in living-labs. However, these installations (and volunteers) may not be easily available. In order to get around that difficulty, this paper suggests the making of a physical model to emulate basic actions of a user at home, thus giving autonomy to researchers wanting to test the performance of their algorithms. This paper also studies some data communication issues in mobile WSNs namely how the orientation of the sensor nodes in the body affects the received signal strength, as well as retransmission aspects of a TDMA-based MAC protocol in the data recovery process.