297 research outputs found

    Thick-layer resists for surface micromachining

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    Abstract. Interest in thick-photoresist applications is steadily growing. In addition to bump fabrication and wire interconnect technology (WIT), the process of patterning thick-layer photoresists by UV lithography is specially qualified for applications in microelectromechanical systems (MEMS). Specialized equipment and new photoresists have been developed or are under development to cope with the new challenges in the field of preparing extremely thick photoresist layers, the process of patterning these thick resists, and to deal with the difficulties of the following galvanoplating step. As one of the most critical steps in thick-photoresist processing, the baking procedure was investigated. Positive tone photoresists (AZ 4562, ma-P 100) were processed by means of three different baking methods: air-forced oven, ramped hotplate, and IR radiation. It could be shown that IR baking is advantageous compared to the other methods with respect to process duration and energy consumption. As for edge steepness, resolution, edge loss, and surface roughness, all methods deliver nearly the same results. A minimum width of 2-3 µm for the resist bars was found to be necessary to withstand the fabrication process of lines and spaces in about 15 µm thick resists. For thicker layers, high aspect ratios of about 10 as well as steep edges of more than 88 • could be fabricated. The development of SU-8, a chemically amplified negative tone photoresist for the 300-450 nm region opened totally new dimensions for the UV depth lithography. Even under development, SU-8 delivers results otherwise only achievable by x-ray lithography. The deposition of photoresist on highly-structured surfaces demands advanced methods. Electrodeposition of resist is one solution. PEPR 2400 was used for patterning by UV light in order to generate resist patterns around a free standing silicon bar. The achieved resist patterns were moulded by using electroplating. For microsystem applications some metals and alloys were deposited. Three-dimensional micro components were fabricated as demonstrators for the new technique. Electrodeposition allows the use of materials with interesting properties which could not be provided by standard processes in microelectronics

    Comparison of Different Caching Techniques for High-Performance Web Map Services

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    The demand for digital maps on the Internet has increased considerably in the last few years. Therefore the performance of Web Mapping Services is becoming more and more important. This article introduces different caching techniques for high performance transfer of data using standardized Open Geospatial Consortium (OGC) Web Map Services (WMS). It describes and examines different caching mechanisms based on tile caching, reverse proxy caching and web application acceleration. Furthermore it demonstrates benefits, problems and how data needs to be modified for different caching techniques. The article outlines the advantages of WMS caching systems and investigates the behaviour of these systems with an increasing number of concurrent requests using benchmark tests. This includes the examination of applicability of the INSPIRE service level agreement for view services

    PCYT1A Missense Variant in Vizslas with Disproportionate Dwarfism

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    Disproportionate dwarfism phenotypes represent a heterogeneous subset of skeletal dysplasias and have been described in many species including humans and dogs. In this study, we investigated Vizsla dogs that were affected by disproportionate dwarfism that we propose to designate as skeletal dysplasia 3 (SD3). The most striking skeletal changes comprised a marked shortening and deformation of the humerus and femur. An extended pedigree with six affected dogs suggested autosomal recessive inheritance. Combined linkage and homozygosity mapping localized a potential genetic defect to a ~4 Mb interval on chromosome 33. We sequenced the genome of an affected dog, and comparison with 926 control genomes revealed a single, private protein-changing variant in the critical interval, PCYT1A:XM_038583131.1:c.673T>C, predicted to cause an exchange of a highly conserved amino acid, XP_038439059.1:p.(Y225H). We observed perfect co-segregation of the genotypes with the phenotype in the studied family. When genotyping additional Vizslas, we encountered a single dog with disproportionate dwarfism that did not carry the mutant PCYT1A allele, which we hypothesize was due to heterogeneity. In the remaining 130 dogs, we observed perfect genotype–phenotype association, and none of the unaffected dogs were homozygous for the mutant PCYT1A allele. PCYT1A loss-of-function variants cause spondylometaphyseal dysplasia with cone–rod dystrophy (SMD-CRD) in humans. The skeletal changes in Vizslas were comparable to human patients. So far, no ocular phenotype has been recognized in dwarf Vizslas. We propose the PCYT1A missense variant as a candidate causative variant for SD3. Our data facilitate genetic testing of Vizslas to prevent the unintentional breeding of further affected puppies

    The Study of the Inhibition of the Recombinant TACE Prodomain to Endotoxemia in Mice

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    Objective: To demonstrate the inhibitory function of the prodomain of tumor necrosis factor-α (TNF-α) converting enzyme (TACE) on TACE activity and to develop an approach to interfere with inflammation processes. Methods: The cDNA encoding the fulllength ectodomain (T1300) and prodomain (T591) of TACE were amplified by RT-PCR. The expression plasmids (pET-28a (+)-T1300 and pET-28a (+)-T591) were constructed and transformed into E. coli BL21. After Ni2+-NTA resin affinity chromatography, the recombinant T591 protein was obtained and assayed. In order to detect its inhibiton of TACE activity, the mice in the LPS-induced endotoxemia model group were treated with the recombinant TACE prodomain protein prior to the injection of LPS. Murine peritoneal macrophages were isolated from mice abdominal cavity for FCM and the liver, kidney and lung were removed for traditionally histopathology sectioning. Results: The FCM results showed that the recombinant prodomain protein decreased the release of the sTNF-α, which mediated the accumulation of TNF-α on the surface of macrophage cells. HE staining proved that the recombinant protein can decrease the inflammatory response in internal organs of endotoxaemia mice. Conclusions: The recombinant prodomain of TACE has the ability to inhibit sTNF-α release, which indicates that prodomain is an effective antagonist of TACE and might be useful in the molecular design of anti-inflammatory drugs

    Informing the future of Australian mining through climate change scenarios

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    Abstract: Mining value chains are vulnerable to a changing climate mainly due to the likelihood of increases in the incidence of extreme weather events. As such events will potentially become more frequent and more intense, the associated impacts such as infrastructure damage, production delays and downtime may damage mine profitability, staff safety, company reputation, regional 'liveability' and government revenues. Mining adaptation strategies to better deal with such impacts can be developed but the options available cannot simply be applied 'across the board' at all mines and in all situations. Various types of mining in Australia occur across 11 main geographic areas, each with its own processes and needs, its own climate signature and its own extreme-event profile. To provide some context for the likely changes in future climate, CSIRO has developed mining region-specific scenarios in association with the OzClim Climate Change Scenario Generator. OzClim generates climate change scenarios using pattern scaling where the change at a particular grid point is normalised by the mean global warming produced by the model for a doubled CO 2 concentration in the atmosphere. The patterns of change are produced for each of the 23 global climate models and for the purposes of the Australian mining regions, we have expressed changes consistent with an historical baseline in order to make the projection information as contextually relevant as possible. To bridge the gap between scenarios and users, CSIRO facilitated workshop events in mining regions. Representatives of a cross-section of the mining chain (including energy, mining, transport, research, water and community stakeholders) were invited to attend, some of whom were first interviewed by facilitators to gain an insight into their operations, understandings, and needs with regard to the workshop. The attendees were presented with future regional climate scenarios, additional information from other studies and climate location analogues helping to further 'set the scene' for the future and helping to facilitate discussion around potential impacts and adaptation needs. Discussions at the workshops provided the means for the scenarios to be placed in their local context, whilst hearing how others in the chain may be directly and indirectly impacted and how they may adapt. Mines and their related infrastructure are frequently long-term investments for all concerned. Therefore, future climate scenarios are valuable for mining value chains and the decision-makers to envisage and plan the future, including adaptation at established sites, alternative processes at new sites and contingency plans that accommodate new levels of variability. Utilising workshops to link future climate scenarios to the value chain and its operational components assisted the end-users to visualise, conceptualise and engage with adaptation decision-making scenarios. The event also brought together participants from different parts of the mining chain who were able to share knowledge and discuss needs that may in the future aid adaptation and avoid maladaptation

    Characterization of yeast strains with conditionally expressed variants of ribosomal protein genes tcm1 and cyh2.

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    We placed a regulatory sequence derived from the GAL10 locus of Saccharomyces cerevisiae at various distances from the start sites of transcription of two yeast ribosomal protein genes, tcm1 and cyh2. The hybrid ribosomal protein genes were transcribed at wild-type levels in the presence of galactose. In the absence of galactose, the hybrid genes were transcribed either at a reduced level or essentially not at all. Yeast cells which transcribe the ribosomal protein genes at a reduced rate continued to grow, suggesting that enhanced translation of the ribosomal protein mRNA may permit an adequate rate of synthesis of the corresponding protein. Consistent with this suggestion is the finding that preexisting mRNA decayed at a reduced rate when transcription was halted abruptly by removal of galactose. Yeast cells unable to transcribe tcm1 or cyh2 without galactose did not grow. These conditional lethal strains demonstrate that the ribosomal proteins encoded by tcm1 and cyh2 are essential; furthermore, these strains are potentially useful for isolating mutations in the tcm1 and cyh2 proteins affecting their transport, assembly, or function

    Inhibition of ADAMTS4 (aggrecanase-1) by tissue inhibitors of metalloproteinases (TIMP-1, 2, 3 and 4)

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    AbstractADAMTS4 (aggrecanase-1) is considered to play a key role in the degradation of aggrecan in arthritides. The inhibitory activity of tissue inhibitors of metalloproteinases (TIMPs) to ADAMTS4 was examined in an assay using aggrecan substrate. Among the four TIMPs, TIMP-3 inhibited the activity most efficiently with an IC50 value of 7.9 nM, which was at least 44-fold lower than that of TIMP-1 (350 nM) and TIMP-2 (420 nM) and >250-fold less than that of TIMP-4 (2 μM for 35% inhibition). These results suggest that TIMP-3 is a potent inhibitor against the aggrecanase activity of ADAMTS4 in vivo

    Scrutinizing the impact of policy instruments on adoption of agricultural conservation practices using Bayesian expert models

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    Policy instruments—such as regulation, financial incentives, and agricultural extension—are commonly applied by governments to promote sustainable agricultural practices and tackle ecosystem degradation. Despite substantial investment, little data are available to gauge the impact of evolving policy mixes. We constructed a Bayesian network model to explore relationships between pol-icy instruments, contextual factors, and adoption. Applying a series of scenarios, we present examples of how different instruments influence adoption and how their effectiveness is shaped by contextual factors. Scenarios highlight that the effect of policy instruments is often modest, and constrained by diverse practice and population characteristics. These findings allow us to reflect on the role of policy instruments, and the conditions necessary to support practice change. For example, our findings raise questions about the role of financial benefits versus financial capacity, and highlight the potential importance of concepts such as mental bandwidth in shaping both motivation and capacity to adopt
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