388 research outputs found

    Drone IV - The Final Chapter (Parasol Drone)

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    Project to create a controllable, aerial drone capable of providing shading from UVA/UVB radiation. Consumers will be able to participate in outdoor activities (run, walk, play sports, etc.) while being protected from the sun. Shading mechanism can open and close midflight with the press of a button. No prior experience necessary for operation. Appropriate for all weather conditions except rain or snow (electronics of drone should not get wet). Adult supervision is necessary for children under the age of twelve

    Infrared Photometric Variability of GX13+1 and GX17+2

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    We present infrared photometry of the Galactic Bulge X-ray binary systems GX13+1 and GX17+2 obtained in 1997 July and August using OSIRIS on the 1.8m Perkins Telescope at Lowell Observatory. GX13+1 clearly varies over ~0.6 magnitudes in the K-band. Our light curve suggests a modulation on a timescale of ~20 days, which is in agreement with previously proposed orbital periods for the system. The IR counterpart of GX17+2 is also variable in the K-band over \~0.8 magnitudes on a timescale of days to weeks, extending the variability first seen by Naylor, Charles, & Longmore (1991). We discuss the implications our data have for Deutsch et al's (1999) identification of ``star A'' as the true IR counterpart of GX17+2. The variability observed in our photometry of the blend of star A and the foreground star NP Ser implies a ~4 magnitude intrinsic variation in the K-band for GX17+2.Comment: Accepted for publication in ApJ, 5 pages, 4 figure

    Integrating On-chain and Off-chain Governance for Supply Chain Transparency and Integrity

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    Integrating on-chain and off-chain data storage for decentralised and distributed information systems, such as blockchain, presents specific challenges for providing transparency of data governance and ensuring data integrity through stakeholder engagement. Current research on blockchain-based supply chains focuses on using on-chain governance rules developed for cryptocurrency blockchains to store some critical data points without designing tailored on-chain governance mechanisms and disclosing off-chain decision-making processes on data governance. In response to this research gap, this paper presents an integrated data governance framework that coordinates supply chain stakeholders with inter-linked on-chain and off-chain governance to disclose on-chain and off-chain rules and decision-making processes for supply chain transparency and integrity. We present a Proof-of-Concept (PoC) of our integrated data governance approach and suggest future research to strengthen scaling up and supply chain-based use cases based on our learnings.Comment: The 5th Symposium on Distributed Ledger Technolog

    NASA Light-Emitting Diodes for the Prevention of Oral Mucositis in Pediatric Bone Marrow Transplant Patients

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    Objective: The purpose of this study was to determine the effects of prophylactic near-infrared light therapy from light-emitting diodes (LEDs) in pediatric bone marrow transplant (BMT) recipients. Background Data: Oral mucositis (OM) is a frequent side effect of chemotherapy that leads to increased morbidity. Near-infrared light has been shown to produce biostimulatory effects in tissues, and previous results using nearinfrared lasers have shown improvement in OM indices. However, LEDs may hold greater potential for clinical applications. Materials and Methods: We recruited 32 consecutive pediatric patients undergoing myeloablative therapy in preparation for BMT. Patients were examined by two of three pediatric dentists trained in assessing the Schubert oral mucositis index (OMI) for left and right buccal and lateral tongue mucosal surfaces, while the patients were asked to rate their current left and right mouth pain, left and right xerostomia, and throat pain. LED therapy consisted of daily treatment at a fluence of 4 J/cm2 using a 670-nm LED array held to the left extraoral epithelium starting on the day of transplant, with a concurrent sham treatment on the right. Patients were assessed before BMT and every 2–3 days through posttransplant day 14. Outcomes included the percentage of patients with ulcerative oral mucositis (UOM) compared to historical epidemiological controls, the comparison of left and right buccal pain to throat pain, and the comparison between sides of the buccal and lateral tongue OMI and buccal pain. Results: The incidence of UOM was 53%, compared to an expected rate of 70–90%. There was also a 48% and 39% reduction of treated left and right buccal pain, respectively, compared to untreated throat pain at about posttransplant day 7 (p \u3c 0.05). There were no significant differences between sides in OMI or pain. Conclusion: Although more studies are needed, LED therapy appears useful in the prevention of OM in pediatric BMT patients

    PrĂĄticas agrĂ­colas de conseqĂŒĂȘncias genĂ©ticas que possibilitaram aos Ă­ndios da AmazĂŽnia uma melhor adaptação Ă s condiçÔes ecolĂłgicas da regiĂŁo

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    Cultivars of food plants actually found in Amazonia that are different from present days wild varieties have been selected by the indians in the last 10,000 years in South America and likely in the last 4,000 to 1,000 years by Amazonian tribes. This paper analyses 40 cultivars of manhioc of Desana and 13 of Tikuna. Surveys in 7 indian tribes reveal an average of 22 cultivars per tribe. Discussed are wild and selected (by the indians) "varieties" of several fruit trees: abiu Pouteria caimito), sapota (Matisia cordata), sapoti (Manilkara zapota), pupunha (Bactris gasipaes), pineapple (Ananas exculenta). Attention is given to some domesticated tuber plants (yam, sweet-potatoes, taro. leren) and to cupĂĄ (Cissus gongilodes); this last one, due to the small distribution may be one of the most recent domestications. It is suggested that the duck (Cairina moschata) domesticated itself in order to occupy the empty niche near the tribes.Os cultivares de plantas, de valor alimentĂ­cio, encontrados na AmazĂŽnia, diferentes da população selvagem encontrada nas matas, foram selecionados pelos Ă­ndios nos Ășltimos 10.000 anos, para a AmĂ©rica do Sul inteira e, possivelmente, nos Ășltimos 4000 a 1000 anos para as plantas domesticadas na AmazĂŽnia. Este trabalho analisa 40 cultivares de mandiocas e macaxeiras dos DesĂąna e 13 dos TikĂșna. Contagens em 7 tribos revelaram uma mĂ©dia de 22 cultivares por tribo. Indica-se para as fruteirasabiu, sapota, sapoti, pupunha, abacaxi, o tamanho e caracterĂ­sticas das plantas selvagens e das selecionadas pelos Ă­ndios. Mencionam-se, tambĂ©m, algumas tuberosas (carĂĄ, batata-doce, taioba, ariĂĄ, caroço-de-umari) domesticadas e o cupĂĄ (Cissus gongilodes); este Ășltimo talvez seja uma das domesticaçÔes mais recentes. Sugere-se que o pato (Cairina moschata) se tenha autodomesticado, por meio de poucas mutaçÔes, com o que ocuparia um nicho ecolĂłgico vazio

    Intraspecific Epitopic Variation in a Carbohydrate Antigen Exposed on the Surface of Trichostrongylus colubriformis Infective L3 Larvae

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    The carbohydrate larval antigen, CarLA, is present on the exposed surface of all strongylid nematode infective L3 larvae tested, and antibodies against CarLA can promote rapid immune rejection of incoming Trichostrongylus colubriformis larvae in sheep. A library of ovine recombinant single chain Fv (scFv) antibody fragments, displayed on phage, was prepared from B cell mRNA of field-immune sheep. Phage displaying scFvs that bind to the surface of living exsheathed T. colubriformis L3 larvae were identified, and the majority of worm-binding scFvs recognized CarLA. Characterization of greater than 500 worm surface binding phage resulted in the identification of nine different anti-CarLA scFvs that recognized three distinct T. colubriformis CarLA epitopes based on blocking and additive ELISA. All anti-CarLA scFvs were specific to the T. colubriformis species of nematode. Each of the three scFv epitope classes displayed identical Western blot recognition patterns and recognized the exposed surface of living T. colubriformis exsheathed L3 larvae. Surprisingly, each of the anti-CarLA scFvs was able to bind to only a subset of worms. Double-labelling indirect immunofluorescence revealed that the three classes of anti-CarLA scFvs recognize distinct, non-overlapping, T. colubriformis sub-populations. These results demonstrate that individual T. colubriformis L3 larvae display only one of at least three distinct antigenic forms of CarLA on their surface at any given time, and suggest that antigenic variation within CarLA is likely a mechanism of immune evasion in strongylid nematodes

    The Orbit of the Eclipsing X-ray Pulsar EXO 1722-363

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    With recent and archival Rossi X-Ray Timing Explorer (RXTE) X-ray measurements of the heavily obscured X-ray pulsar EXO 1722-363 (IGR J17252-3616), we carried out a pulse timing analysis to determine the orbital solution for the first time. The binary system is characterized by a_x sin(i) = 101 +/- 3 lt-s and P_orb = 9.7403 +/- 0.0004 days (90% confidence), with the precision of the orbital period being obtained by connecting datasets separated by more than 7 years (272 orbital cycles). The orbit is consistent with circular, and e < 0.19 at the 90% confidence level. The mass function is 11.7 +/- 1.2 M_sun and confirms that this source is a High Mass X-ray Binary (HMXB) system. The orbital period, along with the previously known ~414 s pulse period, places this system in the part of the Corbet diagram populated by supergiant wind accretors. Using previous eclipse time measurements by Corbet et al. and our orbital solution, combined with the assumption that the primary underfills its Roche lobe, we find i > 61 degrees at the 99% confidence level, the radius of the primary is between 21 R_sun and 37 R_sun, and its mass is less than about 22 M_sun. The acceptable range of radius and mass shows that the primary is probably a supergiant of spectral type B0I-B5I. Photometric measurements of its likely counterpart are consistent with the spectral type and luminosity if the distance to the system is between 5.3 kpc and 8.7 kpc. Spectral analysis of the pulsar as a function of orbital phase reveals an evolution of the hydrogen column density suggestive of dense filaments of gas in the downstream wake of the pulsar, with higher levels of absorption seen at orbital phases 0.5-1.0, as well as a variable Fe K_alpha line.Comment: Submitted to ApJ, 11 pages, 11 figure

    Composition analysis of Ta3N5/W18O49 nanocomposite through XPS

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    A characterization of a nanocomposite material consisting of Ta3N5 nanoparticles and W18O49 nanowires is presented. The material is of interest for photocatalytic applications, with a focus on pollution reduction through the photodegradation of dye waste; under white light illumination, the combination of Ta3N5 and W18O49 yielded an enhanced rate of dye degradation relative to Ta3N5 particles alone. The facile method of synthesis is thought to be a promising route for both upscale and commercial utilization of the material. X-ray photoelectron spectroscopy revealed a core–shell composite structure with W18O49 present as an overlayer on Ta3N5; the analyzed spectra for the C 1s, O 1s, Ta 4f, N 1s, W 4f, and Na 1s regions are reported. It should be noted that due to differential charging of the underlying Ta3N5 component relative to the W18O49 shell, an additional uncompensated voltage shift may exist in the Ta 4f and N 1s spectra

    The enrichment of an alkaliphilic biofilm consortia capable of the anaerobic degradation of isosaccharinic acid from cellulosic materials incubated within an anthropogenic, hyperalkaline environment.

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    Anthropogenic hyper-alkaline sites provide an environment that is analogous to proposed cementitious geological disposal facilities (GDF) for radioactive waste. Under anoxic, alkaline conditions cellulosic wastes will hydrolyse to a range of cellulose degradation products (CDP) dominated by isosaccharinic acids (ISA). In order to investigate the potential for microbial activity in a cementitious GDF, cellulose samples were incubated in the alkaline (∌pH 12), anaerobic zone of a lime kiln waste site. Following retrieval, these samples had undergone partial alkaline hydrolysis and were colonised by a Clostridia dominated biofilm community, where hydrogenotrophic, alkaliphilic methanogens were also present. When these samples were used to establish an alkaline CDP fed microcosm, the community shifted away from Clostridia, methanogens became undetectable and a flocculate community dominated by Alishewanella sp. established. These flocs were composed of bacteria embedded in polysaccharides and protein stabilised by extracellular DNA. This community was able to degrade all forms of ISA with >60% of the carbon flow being channelled into extracellular polymeric substance (EPS) production. This study demonstrated that alkaliphilic microbial communities can degrade the CDP associated with some radioactive waste disposal concepts at pH 11. These communities divert significant amounts of degradable carbon to EPS formation, suggesting that EPS has a central role in the protection of these communities from hyper-alkaline conditions
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