715 research outputs found
Near-infrared Study of the Carina Nebula
We have carried out near-infrared (NIR) imaging observations of the Carina
Nebula for an area of ~400 sq. arcmin. including the star clusters Trumpler 14
(Tr 14) and Trumpler 16 (Tr 16). With 10 sigma limiting magnitudes of J ~ 18.5,
H ~ 17.5 and K_s ~ 16.5, we identified 544 Class II and 11 Class I young star
candidates. We find some 40 previously unknown very red sources with H-K_s > 2,
most of which remain undetected at the J band. The red NIR sources are found to
be concentrated to the south-east of Tr 16, along the `V' shaped dust lane,
where the next generation of stars seems to be forming. In addition, we find
indications of ongoing star formation near the three MSX point sources,
G287.51-0.49, G287.47-0.54, and G287.63-0.72. A handful of red NIR sources are
seen to populate around each of these MSX sources. Apart from this, we
identified two hard Chandra X-ray sources near G287.47-0.54, one of which does
not have an NIR counterpart and may be associated with a Class I/Class 0
object. The majority of the Class II candidates, on the other hand, are seen to
be distributed in the directions of the clusters, demarcating different
evolutionary stages in this massive star-forming region. A comparison of the
color-magnitude diagrams of the clusters with pre-main sequence model tracks
shows that the stellar population of these clusters is very young (< 3 Myr).
The K_s band luminosity function (KLF) of Tr 14 shows structure at the faint
end, including a sharp peak due to the onset of deuterium burning, implying an
age of 1-2 Myr for the cluster. The KLF of Tr 16, in contrast, is found to rise
smoothly until it turns over. The slopes of the mass functions derived for the
clusters are found to be in agreement with the canonical value of the field
star initial mass function derived by Salpeter.Comment: Accepted for publication in ApJ; 45 pages, 18 figures, and 3 tables.
The manuscript with higher resolution figures can be downloaded from
http://cepheus.astro.ncu.edu.tw/~kaushar/download/ms.pd
Micro-fabrication of Carbon Structures by Pattern Miniaturization in Resorcinol-Formaldehyde Gel
A simple and novel method to fabricate and miniaturize surface and
sub-surface micro-structures and micro-patterns in glassy carbon is proposed
and demonstrated. An aqueous resorcinol-formaldehyde (RF) sol is employed for
micro-molding of the master-pattern to be replicated, followed by controlled
drying and pyrolysis of the gel to reproduce an isotropically shrunk replica in
carbon. The miniaturized version of the master-pattern thus replicated in
carbon is about one order of magnitude smaller than original master by
repeating three times the above cycle of molding and drying. The
micro-fabrication method proposed will greatly enhance the toolbox for a facile
fabrication of a variety of Carbon-MEMS and C-microfluidic devices.Comment: 16 pages, 5 figure
Concepts of Animal Health and Welfare in Organic Livestock Systems
In 2005, The International Federation of Organic Agricultural Movements (IFOAM) developed four new ethical principles of organic agriculture to guide its future development: the principles of health, ecology, care, and fairness. The key distinctive concept of animal welfare in organic agriculture combines naturalness and human care, and can be linked meaningfully with these principles. In practice, a number of challenges are connected with making organic livestock systems work. These challenges are particularly dominant in immature agro-ecological systems, for example those that are characterized by industrialization and monoculture. Some of the current challenges are partly created by shortages of land and manure, which encourage zero-grazing and other confined systems. Other challenges are created in part by the conditions for farming and the way in which global food distribution systems are organized, e.g., how live animals are transported, how feed is traded and transported all over the globe, and the development of infrastructure and large herds. We find that the overall organic principles should be included when formulating guidelines for practical organic animal farming. This article explores how the special organic conceptions of animal welfare are related to the overall principles of organic agriculture. The aim is to identify potential routes for future development of organic livestock systems in different contexts and with reference to the specific understanding of animal welfare in organic agriculture. We include two contrasting cases represented by organic livestock systems in northwestern Europe and farming systems in tropical low-income countries; we use these cases to explore the widely different challenges of organic livestock systems in different parts of the world
Droplet manipulation using ZnO/sapphire based saw devices
The hybrid ZnO/Sapphire material is selected to exploit the collective benefits of Zinc Oxide (ZnO) and sapphire for the development of a high performance Surface Acoustic Wave (SAW) device. The microfluidic applications of ZnO/Sapphire layered surface acoustic wave devices are discussed. In addition, acoustic streaming in droplets is investigated using a custom-made ZnO/Sapphire layered device. Experimental results show that a maximum acoustic streaming of ~600 µm/s is achieved when the device is operated at 158 MHz
DEVELOPMENT AND VALIDATION OF RP-HPLC METHOD FOR SIMULTANEOUS ESTIMATION OF THREE-COMPONENT IN TABLET DOSAGE FORMULATION
ABSTRACT:An accurate, simple, reproducible andsensitive method for the determination ofparacetamol, caffeine and chlorpheniraminemaleate in tablet dosage form is developed andvalidated. The separation is achieved usingHiQsilC18HS reverse-phase column (250 X 4.6mm I.D., particle size 5μm) using a mixture ofacetonitrile and water in the proportion 55:300with final pH of 2.4 adjusted with o-phosphoricacid as a mobile phase. The flow rate is 1.0mL/ min and effluents were monitored at 265nm. Total run time is less than 12 min. andretention time of paracetamol, caffeine andchlorpheniramine maleate are 6.742, 9.417, and3.683 min respectively. Validation of method isdone as per ICH guideline for accuracy,precision, linearity, specificity, and sensitivity.The linearity for paracetamol is found to be100-650 μg/mL where as for caffeine andchlorpheniramine maleate is found in the rangeof 15-100 μg/mL. Result of validation study isfound statistically significant because all thestatistical parameters were within theacceptance range (COV and S.D. <1.0 for bothaccuracy and precision). The limits of detection(LOD) values are 1.2014, 0.4587 and 0.8945and limit of quantitation (LOQ) values are0.5142, 0.4512 and 0.7845 μg/mL forparacetamol, caffeine and chlorpheniraminemaleate respectively. High percentage recoveryand low COV value revealed the reliability ofthe method for quantitative study of threedrugs in Fevril tablets as a quality-control toolfor routine quantitative determination ofparacetamol, caffeine and chlorpheniraminemaleate
Field Programmable Gate Array based Readout for Surface Acoustic Wave Portable Gas Detector
Surface acoustic wave (SAW) is one of the most promising technology in the field of gas sensing at low concentrations. Field deployable portable SAW detectors are, however, prone to noise, there by limiting the detection at low concentrations. To meet the current requirements of gas detection at low concentrations, the readout methodology needs to be based on minimal hardware and better noise management. In this paper we describe a readout scheme for portable SAW gas detectors incorporating a field programmable gate array (FPGA). The developed readout system includes a modified reciprocal frequency counter for differential SAW sensor, median noise filtering and moving averages smoothing for noise management, peak detection and interfacing with external display, all implemented in FPGA. The developed readout was tested against VOCs using a lab developed vapour generator and the results have been presented in the paper. The readout system is compact, low power consuming and expandable through software thus ideal for portable handheld applications
Evidence of co-infection of chikungunya and densonucleosis viruses in C6/36 cell lines and laboratory infected Aedes aegypti (L.) mosquitoes
<p>Abstract</p> <p>Background</p> <p>Densonucleosis viruses are the etiological agents of insect's disease. We have reported the isolation of densovirus from India and its distribution among the natural populations of <it>Aedes aegypti </it>mosquitoes across the country. Since densonucleosis virus persistently infects mosquito populations, and is demonstrated to negatively affect multiplication of dengue virus in <it>Aedes albopictus</it>, it would be interesting to study if this virus has a role in determining the susceptibility of the vector mosquito <it>Ae. aegypti </it>to chikugunya virus.</p> <p>Methods</p> <p>Mosquito cell lines and adult <it>Ae. aegypti </it>mosquitoes infected with densovirus were superinfected with Chikungunya virus and both the viruses were quantitated by determining their genomic copy number by real time amplification. Comparison was made between the log of genomic copy numbers of the viruses in the presence and absence of each other.</p> <p>Results</p> <p>The log of copy number of the viruses did not vary due to co-infection. Even though the RNA copy number of chikungunya virus increased over the period of time, no change was observed in the RNA copy number between the control and the co-infected group on any given day. Similarly, DNA copy number of densovirus also remained unchanged between the control and the co-infected groups.</p> <p>Conclusion</p> <p>Chikungunya virus neither stimulates the replication of densovirus nor is its own replication suppressed due to co-infection. <it>Ae. aegypti </it>mosquitoes with densovirus infection were as susceptible to infection by chikungunya virus as the uninfected mosquitoes.</p
Petição para confirmação do direito do consumidor de utilização de programa de comunicações pela internet em redes sem fio e de conexão de dispositivos em tais redes
À medida que a indústria de telecomunicações sem fio amadurece, a consolidação e o relacionamento enFtre as empresas detentoras de infraestrutura de transporte [carriers] e os produtores de aparelhos celulares [handsets] têm revelado práticas de mercado que levantam questionamentos substanciais sobre se os consumidores estariam desfrutando de todos os benefícios possíveis oriundos da competição nas telecomunicações sem fio. Por exemplo, empresas detentoras de infraestrutura de transporte de telecomunicações têm começado a influenciar agressivamente o design de programas [software] e produtos em detrimento do consumidor. Com o amadurecimento do mercado de telecomunicações sem fio e o reconhecimento de que os aparelhos celulares tornaram-se um componente indispensável para muitos americanos, empresas detentoras de infraestrutura de transporte têm utilizado de sua considerável influência sobre o uso e design destes aparelhos para manutenção do controle e dos limites ao direito dos assinantes de executar aplicativos comunicacionais de sua escolha. Ao invés de transportarem as mensagens dos assinantes independentemente do conteúdo, empresas detentoras de infraestrutura de transporte de telecomunicações têm exercido cada vez mais controle sobre a forma como os consumidores acessam a internet móvel. Ao darem preferência a serviços próprios e ao afastarem seus rivais, ditas empresas têm desabilitado ou inutilizado interfaces amigáveis ao consumidor [consumer-friendly features] em dispositivos móveis. Além disso, as empresas detentoras de infraestrutura de transporte de telecomunicações têm implementado tais práticas em violação ao princípio Carterfone da FCC e às restrições constantes da decisão da Comissão em sua formulação original referente à autorização de venda conjugada [bundling] do terminal de acesso individual e do serviço celular. A Comissão deve agir agora para fazer valer a decisão Carterfone e para eliminar os empecilhos que impedem a fruição da totalidade dos benefícios da competição de preços e inovação nas telecomunicações sem fio. À luz destas consequências, a Skype respeitosamente requer que a Comissão deixe inequivocamente claro que o caso Carterfone será aplicado à indústria de telecomunicações sem fio, que inicie uma procedimento para avaliação das práticas de empresas detentoras de infraestrutura essencial de transporte de telecomunicações sem fio à luz do caso Carterfone e que crie um mecanismo orientado pela indústria [industry-led mechanism] para garantia de abertura das redes sem fio. Assim fazendo, a FCC garantirá que os consumidores mantenham o direito de executar aplicativos de sua escolha e que conectem dispositivos não-prejudiciais à rede sem fio. Finalmente, o envolvimento da Comissão nesta temática garantirá que as empresas detentoras de infraestrutura de transporte de telecomunicações não possam utilizar legitimamente de práticas de gestão de rede como desculpa para prática de comportamento prejudicial ao consumidor [anti-consumer]
Phase 4 Pharmacovigilance Trial of Paromomycin Injection for the Treatment of Visceral Leishmaniasis in India
Background. A phase 3 study demonstrated the safety and efficacy of paromomycin (paromomycin IM injection) for treatment of VL in an inpatient setting. Methods. This phase 4 study was conducted to assess the safety and efficacy of paromomycin in children and adults in an outpatient setting in Bihar, India. Results. This study enrolled 506 adult and pediatric patients. Of the 494 patients in the intent-to-treat (ITT) population, 98% received a full course of treatment. The overall study completion rate was 94% (462/494) for the ITT population and 96% (461/479) for the efficacy-evaluable (EE) population. Initial clinical cure was 99.6%, and final clinical cure 6 months after treatment was 94.2%. Grade 3 or 4 adverse events occurred in 5% of patients; events with a frequency of ≥1% were increases in alanine aminotransferase and aspartate aminotransferase. Conclusions. This study confirms the safety and efficacy of paromomycin to treat VL in an outpatient setting
Pulsed-field magnetisation of Y-Ba-Cu-O bulk superconductors fabricated by the infiltration growth technique
Abstract: Bulk high temperature superconductors based on the rare-earth copper oxides can be used effectively as trapped field magnets capable of generating large magnetic fields. The top-seeded infiltration growth (TSIG) processing technique can provide a more homogeneous microstructure and therefore more uniform superconducting properties than samples grown using conventional melt growth processes. In the present investigation, the properties of bulk, single grain superconductors processed by TSIG and magnetised by the pulsed-field magnetisation technique using a copper-wound solenoid have been studied. A trapped field of ∼3 T has been achieved in a 2-step buffer-assisted TSIG-processed Y-Ba-Cu-O (YBCO) sample at 40 K by magnetising the bulk superconductor completely via a single-pulse magnetisation process. Samples were also subjected to pulsed-field magnetisation at 65 K and by conventional field-cooled magnetisation at 77 K for comparison. Good correlation was observed between the microstructures, critical current densities and trapped field performance of bulk samples fabricated by TSIG and magnetised by pulsed-field and field-cooled magnetisation. The homogeneous distribution of Y2BaCuO5 inclusions within the microstructure of bulk YBCO samples fabricated by the 2-step buffer-assisted TSIG process reduces inhomogeneous flux penetration into the interior of the sample. This, in turn, results in a lower temperature rise of the bulk superconductor during the pulsed-field magnetisation process and a more effective and reliable magnetisation process
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