967 resultados para technology development


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Sea anemones are known to contain a wide diversity of biologically active peptides, mostly unexplored according to recent peptidomic and transcriptomic studies. In the present work, the neurotoxic fractions from the exudates of Stichodactyla helianthus and Bunodosoma granulifera were analyzed by reversed-phase chromatography and mass spectrometry. The first peptide fingerprints of these sea anemones were assessed, revealing the largest number of peptide components (156) so far found in sea anemone species, as well as the richer peptide diversity of B. granulifera in relation to S. helianthus. The transcriptomic analysis of B. granulifera, performed by massive cDNA sequencing with 454 pyrosequencing approach allowed the discovery of five new APETx-like peptides (U-AITX-Bg1a-e - including the full sequences of their precursors for four of them), which together with type 1 sea anemone sodium channel toxins constitute a very distinguishable feature of studied sea anemone species belonging to genus Bunodosoma. The molecular modeling of these new APETx-like peptides showed a distribution of positively charged and aromatic residues in putative contact surfaces as observed in other animal toxins. On the other hand, they also showed variable electrostatic potentials, thus suggesting a docking onto their targeted channels in different spatial orientations. Moreover several crab paralyzing toxins (other than U-AITX-Bg1a-e), which induce a variety of symptoms in crabs, were isolated. Some of them presumably belong to new classes of crab-paralyzing peptide toxins, especially those with molecular masses below 2 kDa, which represent the smallest peptide toxins found in sea anemones. (C) 2011 Elsevier Inc. All rights reserved.

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PURPOSE: To evaluate histopathological alterations triggered by brain death and associated trauma on different solid organs in rats. METHODS: Male Wistar rats (n=37) were anesthetized with isoflurane, intubated and mechanically ventilated. A trepanation was performed and a balloon catheter inserted into intracraninal cavity and rapidly inflated with saline to induce brain death. After induction, rats were monitored for 30, 180, and 360 min for hemodynamic parameters and exsanguinated from abdominal aorta. Heart, lung, liver, and kidney were removed and fixed in paraffin to evaluation of histological alterations (H&E). Sham-operated rats were trepanned only and used as control group. RESULTS: Brain dead rats showed a hemodynamic instability with hypertensive episode in the first minute after the induction followed by hypotension for approximately 1 h. Histological analyses showed that brain death induces vascular congestion in heart (p<0.05), and lung (p<0.05); lung alveolar edema (p=0.001), kidney tubular edema (p<0.05); and leukocyte infiltration in liver (p<0.05). CONCLUSIONS: Brain death induces hemodynamic instability associated with vascular changes in solid organs and compromises most severely the lungs. However, brain death associated trauma triggers important pathophysiological alterations in these organs.

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The miniaturization race in the hardware industry aiming at continuous increasing of transistor density on a die does not bring respective application performance improvements any more. One of the most promising alternatives is to exploit a heterogeneous nature of common applications in hardware. Supported by reconfigurable computation, which has already proved its efficiency in accelerating data intensive applications, this concept promises a breakthrough in contemporary technology development. Memory organization in such heterogeneous reconfigurable architectures becomes very critical. Two primary aspects introduce a sophisticated trade-off. On the one hand, a memory subsystem should provide well organized distributed data structure and guarantee the required data bandwidth. On the other hand, it should hide the heterogeneous hardware structure from the end-user, in order to support feasible high-level programmability of the system. This thesis work explores the heterogeneous reconfigurable hardware architectures and presents possible solutions to cope the problem of memory organization and data structure. By the example of the MORPHEUS heterogeneous platform, the discussion follows the complete design cycle, starting from decision making and justification, until hardware realization. Particular emphasis is made on the methods to support high system performance, meet application requirements, and provide a user-friendly programmer interface. As a result, the research introduces a complete heterogeneous platform enhanced with a hierarchical memory organization, which copes with its task by means of separating computation from communication, providing reconfigurable engines with computation and configuration data, and unification of heterogeneous computational devices using local storage buffers. It is distinguished from the related solutions by distributed data-flow organization, specifically engineered mechanisms to operate with data on local domains, particular communication infrastructure based on Network-on-Chip, and thorough methods to prevent computation and communication stalls. In addition, a novel advanced technique to accelerate memory access was developed and implemented.

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Recent changes in the cost and availability of natural gas (NG) as compared to diesel have sparked interest at all levels of the commercial shipping sector. In particular, Class 1 heavy-duty rail has been researching NG as a supplement to diesel combustion. This study investigates the relative economic and emissions advantage of making use of the energy efficiencies if combustion is circumvented altogether by use of fuel cell (FC) technologies applied to NG. FC technology for the transport sector has primarily been developed for the private automobile. However, FC use in the automobile sector faces considerable economic and logistical barriers such as cost, range, durability, and refueling infrastructure. The heavy-duty freight sector may be a more reasonable setting to introduce FC technology to the transportation market. The industry has shown interest in adopting NG as a potential fuel by already investing in NG infrastructure and locomotives. The two most promising FC technologies are proton exchange membrane fuel cells (PEMFCs) and solid oxide fuel cells (SOFCs). SOFCs are more efficient and capable of accepting any kind of fuel, which makes them particularly attractive. The rail industry can benefit from the adoption of FC technology through reduced costs and emissions, as well as limiting dependence on diesel, which accounts for a large portion of operation expenses for Class 1 railroads. This report provides an economic feasibility analysis comparing the use of PEMFCs and SOFCs in heavy freight rail transport applications. The scope is to provide insight into which technologies could be pursued by the industry and to prioritize technologies that need further development. Initial results do not show economic potential for NG and fuel cells in locomotion, but some minimal potential for reduced emissions is seen. Various technology configurations and market scenarios analyzed could provide savings if the price of LNG is decreased and the price of diesel increases. The most beneficial areas of needed research include technology development for the variable output of SOFCs, and hot start-up optimization.

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Sanitation has evolved from a purely technical discipline to one that includes social, environmental, economic and, increasingly, gender considerations. However, blurry notions of gender are frequently offered in the sanitation literature. Although it has been recognized that gender-responsive sanitation does not mean ‘toilets for women’, substantial alternatives are rarely debated. We structure our review of sanitation in developing countries along three lines: we start by fine-tuning the concept of gender both from the academic and the practitioner's perspective, analyse relevant developments in gender-specific policies and programming, and finally review the most appropriate toilet room and menstrual hygiene technologies. We argue that strategies to make technologies gender-responsive need to be based upon a thorough analysis of the social arrangements of the intimate, and how these are negotiated and institutionalized in a specific context. A lack of robust gender-segregated data on sanitation policies and technologies, along with reductionist framings of gender are to blame for limited progress in verifying the need for, and impact of, gender-responsive sanitation. Technology and policy development and implementation would benefit from gender-considerate interpretations of shame, dignity, safety and status. Further progress could be achieved by improving the translation process between different academic framings of the sanitation crisis. Keywords: appropriate technology; development; gender; menstrual hygiene management (MHM); sanitation