Epidemiological investigations of bovine trypanosomiasis in the common fly belt of Zambia

The causes of anaemia in cattle are reviewed and it was postulated that trypanosomiasis or malnutrition were the main factors in affecting herd mean packed cell volume (PCV). In 1995/6 ~ 18,000 cattle from 495 herds raised in the common tsetse fly belt of Zambia were examined haematologically, and PCV values were recorded with peripheral blood examined for trypanosomes via the bufify coat smear technique. Giemsa stained thick and thin dried blood smears (T&TS) were also examined. The results were entered into a tailor made Integrated Tsetse and Trypanosomiasis Database and were summarised as mean herd PCV, proportion of herd anaemic and parasitological prevalence. Using a linear regression model, ~ 36% of the variance of the mean herd PCV could be accounted for by parasitological prevalence. A logistic regression of the data gave little improvement. The sensitivities of the buffy coat as well as T&TS examinations were calculated mathematically based on the Poisson distribution and these diagnostic techniques were reckoned to be probably more sensitive than previous work had suggested. The spatial distribution of bovine trypanosomiasis and the herd haematocrit values are displayed using a Geographical Information System (GIS). An indirect enzyme linked immunosorbent assay was developed for the detection oftrypanosomal antibodies (Ab-ELISA) in serum using crude somatic antigen from T. congolense. The assay was further adapted to carry out tests using circles of dried blood held on filter paper. Inter and intra-assay sources of variation were investigated, as were the effects of sample storage and management. The assay was compared to the indirect fluorescent antibody test, and kinetics of anti-trypanosomal antibody were examined. Twelve thousand blood spot samples were assayed and the data were subject to a rigorous system of quality assurance, with the percentage positivity system of data expression being adopted. The necessary calculations were performed by a computer program. The direct parasitological prevalence and Ab-ELISA sero-prevalence results were compared on a herd basis, and conjectural reasons why there were differences were given. A linear model, with antibody sero prevalence as the independent, only accounted for ~ 50% of the mean herd PCV variance. Protein malnutrition is presumed to account for the remaining 50%. An Antibody ELISA Database was developed for the serological survey results and maps using GIS software are displayed. The costs of direct tests for trypanosomiasis and Ab-ELISA are reviewed and recommendations are given for the development of the assa

“Coign of Vantage” e ação: Considerando a responsabilidade local e planos de financiamento de escola da Califórnia para estudantes de inglês

Local control has been a bedrock principle of public schooling in America since its inception. In 2013, the California Legislature codified a new local accountability approach for school finance. An important component of the new California Local Control Funding Formula (LCFF) approach is a focus on English learners (ELs). The law mandates that every school district produce a Local Control Accountability Plan (LCAP) to engage the local community in defining outcomes and determining funding for ELs. Based on an exploratory analysis of a representative sample of LCAPs, we show that, although California’s new approach offered an opportunity to support locally-defined priorities and alternatives to top-down accountability, few if any districts had yet taken full advantage of the opportunity. That is, the school districts in our sample had not yet engaged with the local community to facilitate significant changes to accountability or redistribution of funding and resources to support educational equity for ELs.El control local ha sido un principio fundamental de la educación pública en América desde su creación. En 2013, la Legislatura de California codificó un nuevo enfoque de responsabilidad local para las finanzas escolares. Un componente importante del nuevo enfoque de California Local Control Funding Formula (LCFF) es un enfoque en los estudiantes de inglés (ELs). La ley exige que cada distrito escolar produzca un Plan de Responsabilidad de Control Local (LCAP) para involucrar a la comunidad local en la definición de resultados y la determinación de fondos para ELs. Basado en un análisis exploratorio de una muestra representativa de LCAPs, mostramos que, aunque el nuevo enfoque de California ofreció una oportunidad para apoyar las prioridades definidas localmente y las alternativas a la responsabilidad de arriba a abajo, pocos o ninguno de los distritos habían aprovechado la oportunidad. Es decir, los distritos escolares de nuestra muestra aún no se habían comprometido con la comunidad local para facilitar cambios significativos en la rendición de cuentas o la redistribución de fondos y recursos para apoyar la equidad educativa para los EL.O controle local tem sido um princípio fundamental da educação pública na América desde a sua criação. Em 2013, a Califórnia Legislativo codificada uma nova abordagem à responsabilidade local para as finanças da escola. Um componente importante da nova abordagem local fórmula de financiamento Controle Califórnia (LCFF) é um foco em estudantes de inglês (ELS). A lei exige que cada distrito escolar para produzir um Accountability Plano de Controle Local (LCAP) para envolver a comunidade local na definição de resultados e determinação de fundos para ELs. Com base em uma análise exploratória de uma amostra representativa de LCAPs, mostramos que, embora a nova abordagem da Califórnia ofereceu uma oportunidade para apoiar as prioridades definidas localmente e alternativas a responsabilidade de cima para baixo, poucos ou nenhum dos distritos tinha tomado a oportunidade. Ou seja, os distritos escolares em nossa amostra ainda não tinha sido comprometida com a comunidade local para fazer mudanças significativas na prestação de contas ou redistribuição de fundos e recursos para apoiar a equidade educacional para ELs.

Microevolution during the emergence of a monophasic Salmonella Typhimurium epidemic in the United Kingdom

Microevolutionary events associated with the emergence and clonal expansion of new 27 epidemic clones of bacterial pathogens hold the key to understanding the drivers of 28 epidemiological success. We describe a comparative whole genome sequence and 29 phylogenomic analysis of monophasic Salmonella Typhimurium isolates from the UK 30 and Italy from 2005-2012. Monophasic isolates from this time formed a single clade 31 distinct from recent monophasic epidemic clones described previously from North 32 America and Spain. The current UK monophasic epidemic clones encode a novel 33 genomic island encoding resistance to heavy metals (SGI-3), and composite transposon 34 encoding antibiotic resistance genes not present in other Typhimurium isolates, that 35 may have contributed to the epidemiological success. We also report a remarkable 36 degree of genotypic variation that accumulated during clonal expansion of a UK 37 epidemic including multiple independent acquisitions of a novel prophage carrying the 38 sopE gene and multiple deletion events affecting the phase II flagellin locus

Plasmodium falciparum parasites with histidine-rich protein 2 (pfhrp2) and pfhrp3 gene deletions in two endemic regions of Kenya.

Deletions of the Plasmodium falciparum hrp2 and hrp3 genes can affect the performance of HRP2-based malaria rapid diagnostic tests (RDTs). Such deletions have been reported from South America, India and Eritrea. Whether these parasites are widespread in East Africa is unknown. A total of 274 samples from asymptomatic children in Mbita, western Kenya, and 61 genomic  data from Kilifi, eastern Kenya, were available for analysis. PCR-confirmed samples were investigated for the presence of pfhrp2 and pfhrp3 genes. In samples with evidence of deletion, parasite presence was confirmed by amplifying three independent genes. We failed to amplify pfhrp2 from 25 of 131 (19.1%) PCR-confirmed samples. Of these, only 8 (10%) samples were microscopic positive and were classified as pfhrp2-deleted. Eight microscopically-confirmed pfhrp2-deleted samples with intact pfhrp3 locus were positive by HRP2-based RDT. In addition, one PCR-confirmed infection showed a deletion at the pfhrp3 locus. One genomic sample lacked pfhrp2 and one lacked pfhrp3. No sample harbored parasites lacking both genes. Parasites lacking pfhrp2 are present in Kenya, but may be detectable by HRP-based RDT at higher parasitaemia, possibly due to the presence of intact pfhrp3. These findings warrant further systematic study to establish prevalence and diagnostic significance

Syngenetic sand veins and anti-syngenetic sand wedges, Tuktoyaktuk Coastlands, western Arctic Canada

Sand-sheet deposits of full-glacial age in the Tuktoyaktuk Coastlands, western Arctic Canada, contain syngenetic sand veins 1-21 cm wide and sometimes exceeding 9 m in height. Their tall and narrow, chimney-like morphology differs from that of known syngenetic ice wedges and indicates an unusually close balance between the rate of sand-sheet aggradation and the frequency of thermal-contraction cracking. The sand sheets also contain rejuvenated (syngenetic) sand wedges that have grown upward from an erosion surface. By contrast, sand sheets of postglacial age contain few or sometimes no intraformational sand veins and wedges, suggesting that the climatic conditions were unfavourable for thermal-contraction cracking. Beneath a postglacial sand sheet near Johnson Bay, sand wedges with unusually wide tops (3.9 m) extend down from a prominent erosion surface. The wedges grew vertically downward during deflation of the ground surface, and represent anti-syngenetic wedges. The distribution of sand veins and wedges within the sand sheets indicates that the existence of continuous permafrost during sand-sheet aggradation can be inferred confidently only during full-glacial conditions

The chronostratigraphy of Late Pleistocene glacial and periglacial aeolian activity in the Tuktoyaktuk Coastlands, NWT, Canada

Aeolian periglacial sand deposits are common in the Tuktoyaktuk Coastlands of Western Arctic Canada. Regionally extensive and thick aeolian sand-sheet deposits have been observed in two major stratigraphic settings: within a sand unit characterized by large aeolian dune deposits; and interbedded with glaciofluvial outwash from the Laurentide Ice Sheet (LIS). Small, localized sand sheets have also been observed along the tops of sandy bluffs, within sequences of drained thermokarst lakes deposits and as an involuted veneer above buried basal ice of the LIS. On the basis of radiocarbon and optically stimulated luminescence (OSL) dates from preserved periglacial aeolian sand sheets and dunes a regional chronostratigraphy is presented which indicates that both extensive dunes and sand sheets accumulated mainly between ca 30 and 13 ka. A switch to dominantly sand-sheet aggradation at ca 14–13 ka, with sand sheets forming widely until ca 8 ka, is attributed to (a) surface armouring by glacial deposits associated with the advance of the LIS; and (b) amelioration of the climate from cold aridity. An absence of OSL dates between ca 8 and 1 ka suggests that sand sheets stabilized during much of the Holocene. Local sand-sheet aggradation during recent centuries has occurred near sandy bluffs and on the floors of drained thermokarst lakes. The OSL dates constrain the maximum extent of the LIS in the Tuktoyaktuk Coastlands to Marine Isotope Stage 2

Host Galaxies of Luminous Type 2 Quasars at z ~ 0.5

We present deep Gemini GMOS optical spectroscopy of nine luminous quasars at redshifts z ~ 0.5, drawn from the SDSS type 2 quasar sample. Our targets were selected to have high intrinsic luminosities (M_V < -26 mag) as indicated by the [O III] 5007 A emission-line luminosity (L_[O III]). Our sample has a median black hole mass of ~ 10^8.8 M_sun inferred assuming the local M_BH-sigma_* relation and a median Eddington ratio of ~ 0.7, using stellar velocity dispersions sigma_* measured from the G band. We estimate the contamination of the stellar continuum from scattered quasar light based on the strength of broad H-beta, and provide an empirical calibration of the contamination as a function of L_[O III]; the scattered light fraction is ~ 30% of L_5100 for objects with L_[O III] = 10^9.5 L_sun. Population synthesis indicates that young post-starburst populations (< 0.1 Gyr) are prevalent in luminous type 2 quasars, in addition to a relatively old population (> 1 Gyr) which dominates the stellar mass. Broad emission complexes around He II 4686 A with luminosities up to 10^8.3 L_sun are unambiguously detected in three out of the nine targets, indicative of Wolf-Rayet populations. Population synthesis shows that ~ 5-Myr post-starburst populations contribute substantially to the luminosities (> 50% of L_5100) of all three objects with Wolf-Rayet detections. We find two objects with double cores and four with close companions. Our results may suggest that luminous type 2 quasars trace an early stage of galaxy interaction, perhaps responsible for both the quasar and the starburst activity.Comment: 20 pages, 13 figures, 7 tables; accepted to Ap

Analytical and computational indoor shelter models for infiltration of carbon dioxide into buildings : comparison with experimental data

This paper describes two indoor shelter models – an analytical model and a Computational Fluid Dynamics (CFD) model - that can be used to predict the level of infiltration of carbon dioxide (CO2) into a building following a release from an onshore CO2 pipeline. The motivation behind the development of these models was to demonstrate that the effects of shelter should be considered as part of a Quantitative Risk Assessment (QRA) for CO2 pipeline infrastructure and to provide a methodology for considering the impact of a CO2 release on building occupants.A key component in the consequence modelling of a release from a CO2 pipeline is an infiltration model for CO2 into buildings which can describe the impact on people inside buildings during a release event. This paper describes the development of an analytical shelter model and a CFD model which are capable of predicting the change in internal concentration, temperature and toxic load within a single roomed building that is totally engulfed by a transient cloud of gaseous CO2. Application of the models is demonstrated by comparison with experimental measurements of CO2 accumulation in a building placed in the path of a drifting cloud of CO2. The analytical and CFD models are shown to make good predictions of the average change in internal concentration. Furthermore, it is demonstrated that the effects of shelter should be taken into account when conducting QRA assessments on CO2 pipelines. Document type: Articl

A miniature, lowpower , intelligent sensor node for persistent acoustic surveillance

ABSTRACT The desire for persistent, long term surveillance and covertness places severe constraints on the power consumption of a sensor node. To achieve the desired endurance while minimizing the size of the node, it is imperative to use application-specific integrated circuits (ASICs) that deliver the required performance with maximal power efficiency while minimizing the amount of communication bandwidth needed. This paper reviews our ongoing effort to integrate several micropower devices for low-power wake-up detection, blind source separation and localization and pattern classification, and demonstrate the utility of the system in relevant surveillance applications. The capabilities of each module are presented in detail along with performance statistics measured during recent experiments