Academic literature on the topic 'Centrifugal broadcaster'

Sperm movement has been described in several phyla of invertebrates. Yet, sperm motility has only been quantified using computer-aided sperm analysis (CASA-Mot) in externally fertilising species (broadcast spawners) of two phyla, molluscs and echinoderms. In the present study we quantified in detail the nature of the sperm tracks, percentage motility groupings and detailed kinematics of rapid-, medium- and slow-swimming spermatozoa in the oyster Crassostrea gigas and four species never previously studied by CASA-Mot, namely the molluscs Choromytilus meridionalis, Donax serra and Haliotis midae and the echinoderm Parechinus angulosus. A feature common to all these species are the helical tracks, the diameter of which seems to be species specific. Using CASA-Mot, the behaviour of spermatozoa was also studied over time and in the presence of egg water and Ca2+ modulators such as caffeine and procaine hydrochloride. For the first time, we show that hyperactivation can be induced in all species in the presence of egg water (sea water that was mixed with mature eggs and then centrifuged) and/or caffeine, and these hyperactivated sperm tracks were characterised using CASA-Mot. We relate the different patterns of sperm motility and behaviour to reproductive strategies such as broadcast spawning and spermcasting, and briefly review studies using CASA-Mot on other invertebrates.

Abstract Despite the fact that simple interventions and emerging therapies can increase survival of SCD patients, under detection renders SCD a major cause of under age-5 mortality in rural regions of the developing world where it is prevalent. (Piel et PLoS Med DOI: org/10.1371/journal.pmed.1001484, 2013). Two major diagnostic challenges are: 1. A lack of affordable diagnostic methodology to obtain point-of-care results in low-resource environments. 2. Dispersion of SCD patients in vast rural hinterlands who rarely interface with healthcare services. To address the first impediment, we have developed and validated a simple, low-cost test to screen for SCD using aqueous multiphase systems (AMPS). AMPS are solutions of polymers and surfactants that form immiscible self-assembling step-gradients. An AMPS designed to target the density signature of sickle cell anemia forms the basis of this novel diagnostic technique. (Kumar et al, PNAS DOI:10.1073/pnas.14147391110, 2014). Building on a design previously tested in Zambia (Kumar et al, PLoS One DOI: 10.1371/journal.pone.0114540, 2014) an improved test has been developed and named "Mpana" for "Multi-Phase Analyzer." The Mpana test detects the presence or absence of cells with a high mass-density as an indirect method to test for the presence of sickled cells. The test uses 5 µL of fingerstick blood, can be performed in 15 minutes using an inexpensive ($150), battery-powered centrifuge, the results can be read with the naked eyes by a trained reader (Figure 1) and costs 50 cents per test. The improved density-based test was first verified on fingerstick samples in the U.S. before being validated in a field study in rural Zambia. To manage the access difficulty of large-scale rural SCD screening, we exploited a partnership with the National Zambian Dental Training School. We have previously demonstrated that provision of free toothbrushes, toothpaste and other minimal health services is a powerful magnet to attract subjects in rural regions of Zambia that have high rates of tooth decay. Once collected these individuals can receive other healthcare interventions such as SCD screening. We conducted a cross-sectional field test of this approach in August and September of 2017 in the rural Serenje and Chitambo Districts of Northern Zambia. A local drama group and radio and mobile broadcasts informed the target communities about the dental intervention that attracted over 700 subjects. Of these, 503 children aged 1 month to 18 years were symptom screened for SCD, tested with MPANA, and dried blood spot (DBS) samples collected. The DBS were analyzed by iso-electric focusing and high-performance liquid chromatography at the New England Newborn Screening Program. Of the screened subjects, 78 had sickle cell trait and 17 had SCD. A score was assigned to visual readings of the MPANA test to enable ROC analysis.The ROC curve shows good diagnostic performance with an area under the curve (AUC) of 0.84. (Figure 2) The MPANA test had a sensitivity of 71% (CI 47-88%) and a specificity of 99% (CI 98-100%), with an overall diagnostic accuracy of 98% (CI 97-99%). Importantly, the MPANA test had a negative predictive value of 99% (CI 98-100%). Combining Mpana results with a clinical symptom score yielded a slightly improved specificity of 100% (CI 99.5-100%) and yielded an overall diagnostic accuracy of 99% (CI 98-100%). In conclusion, a multidisciplinary consortium has achieved the first validation of a low-cost simple point of care test to diagnose SCD in a rural area of a developing nation and has demonstrated the ability of dental services to facilitate such screening. Offsetting the theoretical concern that the MPANA test might not detect SCD in neonates and young infants due to their high hemoglobin F content are the advantages that our SCD screening strategy is low cost, primarily utilizes local resources and immediately delivers positive subjects to care interventions (which could be anything in addition to or other than SCD screening). It is therefore amenable to scaling up for widespread application. Acknowledgments: The Provincial and District Offices, Rural Health Centers and communities that granted permissions and participated in this study. Author Contributions: Contributed equally to the work - CMCL,AAK,TPS Conflict-of-interest disclosure: Competing financial interests declared. Correspondence: Catherine Chunda-Liyoka, e-mail: catherinechunda@yahoo.co.uk Disclosures Kumar: Harvard University: Patents & Royalties: I am an inventor on patents for the underlying technology and the patent has been assigned to Harvard.. Humpton:Nano Terra, Inc.: Employment. Whitesides:Harvard University: Patents & Royalties: Harvard holds patents for this work. Stossel:Harvard University: Patents & Royalties: Co-inventor on MPANA patent. No royalties.

The correct use and distribution of correctives and fertilizers on growth areas, setting right the soil or returning the nutrients exported by the crops, is one of the most important techniques to increase and maintain the agricultural income. The centrifugal broadcasters of solid products are increasingly used because of its practicality, simplicity and high operational capacity. Its main use is on the application of corrective and fertilization products of agricultural soils, which can apply calcareous, agricultural gypsum, mineral fertilizer and, once these resources are finite, they demand a rationalization on the use and, as a consequence, the correct application becomes indispensable. The development of virtual prototypes has been a great successful and reliable tool in the last years, offering the opportunity to verify the viability of a prototype by simulation without the need to build it. In this context, the present study intent to evaluate the real behavior of projected prototypes in track conditions compared with a conventional disk. The prototypes used in search were developed in a master thesis of the Postgraduate Program in Agricultural Engineering by the academic Mech. Eng. Elton Neves da Silva. Based on the graphics of distribution analyzes obtained from the simulations, it was chosen for the prototypes called Conic 6 Wings Middle and Plan 6 Wings Middle, which were the ones that presented the best results. The observations demonstrated that the width of work for a conventional disc, in the position 50% of wings course, was the one that presented a higher value, getting to 25 meters, in a right alternate system. The Conic prototype presented, for the CV of 15%, a width inferior to 10 meters, independent of the work method used, and the Plan prototype presented the smallest value of work width, getting, at maximum, 7,5 meters for the CV stipulated of 15%. At the evaluation of the longitudinal profile of distribution, as for the conventional disc in three positions as for the Conic and Plan prototypes, both presented a uniformity of distribution. In comparison between the conventional disc and the prototypes, the conventional disc revealed better results for all the work methods.<br>A correta utilização e distribuição de corretivos e fertilizantes nas áreas de cultivo, corrigindo o solo ou repondo os nutrientes exportados pelas culturas, é uma das mais importantes técnicas para incrementar ou manter o rendimento agrícola. Os distribuidores centrífugos de produtos sólidos são cada vez mais utilizados pela sua praticidade, simplicidade e alta capacidade operacional. Seu principal uso é na aplicação de produtos de correção e adubação de solos agrícolas, podendo distribuir calcário, gesso agrícola, adubo mineral e, como estes recursos são finitos, necessitam de uma racionalização no seu uso, sendo que, para isso, a aplicação correta torna-se indispensável. O desenvolvimento de protótipos virtuais tem sido uma ferramenta de grande sucesso e confiabilidade nos últimos anos, em função de oferecer a possibilidade de se verificar a viabilidade de um protótipo por meio de simulações, sem a necessidade de construí-lo. Nesse contexto, o presente estudo teve por objetivo avaliar o real comportamento de protótipos projetados, em condições de pista, em comparação com um disco convencional. Os protótipos utilizados na pesquisa foram desenvolvidos em uma dissertação de mestrado do Programa de Pós Graduação em Engenharia Agrícola (PPGEA) pelo acadêmico Engenheiro Mecânico Elton Neves da Silva. Com base na análise dos gráficos de distribuição obtidos nas simulações, optou-se pelos protótipos denominados Cônico 6 Aletas Meio e Plano 6 Aletas Meio, os quais apresentaram os melhores resultados. As observações mostram que a largura de trabalho para o disco convencional, na posição 50% do curso das aletas, foi a que apresentou maior valor, chegando aos 25 metros no sistema alternado direito. O protótipo cônico apresentou, para o CV de 15%, uma largura inferior aos 10 metros, independente do método de trabalho utilizado, e o protótipo plano apresentou o menor valor de largura de trabalho, chegando a, no máximo, 7,5 metros para o CV estipulado de 15%. Na avaliação do perfil de distribuição longitudinal, tanto o disco convencional, nas 3 posições, quanto os protótipos cônico e plano, mostraram uma distribuição uniforme. Na comparação entre o disco convencional e os protótipos, o disco convencional mostrou melhores resultados para todos os métodos de trabalho.