High heterogeneity of malaria transmission and a large sub-patent and diverse reservoir of infection in Wusab As Safil district, Republic of Yemen.

BACKGROUND: Yemen remains the country with the highest malaria transmission within the Arabian Peninsula and a source of imported cases to neighbouring countries. METHODS: This study collected samples from individuals resident in a valley in Western Yemen as a baseline to examine infection prevalence for a future trial. As well as rapid diagnostic test (RDT) and microscopy, a filter paper blood spot was collected for molecular and serological analyses. RESULTS: Samples were collected from 2261 individuals from 12 clusters across a study area of approximately 100 km(2). Plasmodium falciparum infection prevalence was 12.4, 11.1 and 19.6% by RDT, microscopy and polymerase chain reaction (PCR), respectively. RDT and microscopy did not detect 45% of infections present, suggesting many infections were low-density. Infection prevalence and seroprevalence were highly heterogeneous between clusters, with evidence of higher exposure in clusters close to the wadi. The mean multiplicity of infection (MOI) was 2.3 and high heterozygosity and allelic richness were detected. CONCLUSIONS: This highly diverse parasite population suggests a high degree of transmissibility and coupled with the substantial proportion of low-density infections, may pose challenges for malaria control and elimination efforts

An integration model for identifying the determinants of the adoption and implementation level of HRIS applications and Its effectiveness in business organisations in Jordan

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel UniversityThis thesis investigates the influence of firms’ internal and external environmental factors upon their adoption of HRIS behaviour (i.e., the variation between adopters and non-adopters) and the level of implementation of HRIS applications and its effectiveness. An integrated conceptual framework was developed for the factors that determine the organisation’s adoption and the level of practice of HRIS applications. This framework integrates ideas and elements from the Diffusion of innovation Theory (DOI) and technology organization environment (TOE) model, the Unified Theory of Acceptance and Use of Technology (UTAUT) and the IT studies in the area of HRM. Data were collected through structured-directed interviews with 236 respondents. The survey units were the shareholding companies in Jordan, and the key single respondents approach was employed. The findings of the study support that internal and external environmental factors are related not only to adoption of HRIS behaviour (i.e., the difference between adopters and non-adopters), but also to the level of implementing of HRIS applications. In comparison to each environmental dimension acting alone, the integration approach of the two internal and external dimensions gives better explanation not only of the prediction of the level of implementing of HRIS applications, but also of the prediction of adoption behaviour. Therefore, a better understanding of adoption of HRIS behaviour and the level of implementing of HRIS applications requires that firms’ environmental factors be viewed as whole (i.e., the interaction of the internal and external dimension) rather than being isolated fragments (i.e., only a single dimension). The current research contributes to the existing body of knowledge by enhancing current understanding of the organisational adoption of HRIS, which is an under-researched area in Jordan as a developing country. By employing analytical tools based on Rogers’s Innovation Diffusion Theory , UTAUT, TOE , and the findings of empirical studies of IT adoption, evidence confirms that the adoption of HRIS in the business organisations depends largely on interaction of internal and external environmental factors and the findings support the need for an integrated view of the adoption phenomenon. In that respect, this study also attempts to make an important theoretical contribution towards articulating differences in the determinants of adoption and the level of implementations of HRIS applications and its effectiveness

Catalysis by hen egg-white lysozyme proceeds via a covalent intermediate

Hen egg-white lysozyme (HEWL) was the first enzyme to have its three-dimensional structure determined by X-ray diffraction techniques(1). A catalytic mechanism, featuring a long-lived oxo-carbenium-ion intermediate, was proposed on the basis of model-building studies(2). The `Phillips' mechanism is widely held as the paradigm for the catalytic mechanism of beta -glycosidases that cleave glycosidic linkages with net retention of configuration of the anomeric centre. Studies with other retaining beta -glycosidases, however, provide strong evidence pointing to a common mechanism for these enzymes that involves a covalent glycosyl-enzyme intermediate, as previously postulated(3). Here we show, in three different cases using electrospray ionization mass spectrometry, a catalytically competent covalent glycosyl-enzyme intermediate during the catalytic cycle of HEWL. We also show the three-dimensional structure of this intermediate as determined by Xray diffraction. We formulate a general catalytic mechanism for all retaining beta -glycosidases that includes substrate distortion, formation of a covalent intermediate, and the electrophilic migration of C1 along the reaction coordinate

Luminous infrared galaxies as possible sources of the UHE cosmic rays

Ultra High Energy (UHE) particles coming from discrete extragalactic sources are potential candidates for EAS events above a few tens of EeV. In particular, galaxies with huge infrared luminosity triggered by collision and merging processes are possible sites of UHECR acceleration. Using the PSCz catalogue of IR galaxies we calculate a large scale anisotropy of UHE protons originating in the population of the luminous infrared galaxies (LIRGs). Small angle particle scattering in weak irregular extragalactic magnetic fields as well as deflection by regular Galactic field are taken into account. We give analytical formulae for deflection angles with included energy losses on cosmic microwave background (CMB). The hypotheses of the anisotropic and isotropic distributions of the experimental data above 40 EeV from AGASA are checked, using various statistical tests. We show that on the basis of the small scale clustering analysis there is a much better correlation of the UHECRs data below GZK cut-off with the predictions of the LIRG origin than with those of isotropy. We derive analytical formulae for a probability of a given number of doublets, triplets and quadruplets for any density distribution of independent events on the sky. The famous AGASA UHE triple event is found to be very well correlated on the sky with the brightest extragalactic infrared source within 70 Mpc - merger galaxies Arp 299 (NGC 3690 + IC 694).Comment: 17 pages, 10 figures, accepted for publ: Journal of Physics

Two-neutron transfer reaction mechanisms in 12^{12}C(6^6He,4^{4}He)14^{14}C using a realistic three-body 6^{6}He model

The reaction mechanisms of the two-neutron transfer reaction $^{12}$C($^6$He,$^4$He) have been studied at 30 MeV at the TRIUMF ISAC-II facility using the SHARC charged-particle detector array. Optical potential parameters have been extracted from the analysis of the elastic scattering angular distribution. The new potential has been applied to the study of the transfer angular distribution to the 2$^+_2$ 8.32 MeV state in $^{14}$C, using a realistic 3-body $^6$He model and advanced shell model calculations for the carbon structure, allowing to calculate the relative contributions of the simultaneous and sequential two-neutron transfer. The reaction model provides a good description of the 30 MeV data set and shows that the simultaneous process is the dominant transfer mechanism. Sensitivity tests of optical potential parameters show that the final results can be considerably affected by the choice of optical potentials. A reanalysis of data measured previously at 18 MeV however, is not as well described by the same reaction model, suggesting that one needs to include higher order effects in the reaction mechanism.Comment: 9 pages, 9 figure

Sine square distribution: a new statistical model based on the sine function

This paper introduces a new continuous distribution based on the sine function. The proposed Sine Square distribution has one parameter and its domain depends on this parameter. The probability density function f(x) of a Sine Square variable X as well as its cumulative distribution function F(x) are defined. The formulas for the rth raw moment and central moments, moments generating function (m.g.f.), characteristic function (c.f.) and some other properties of the new distribution are provided. A method to generate random variables from the Sine Square distribution is analyzed and applied

Factor structure and construct validity of the Adult Social Care Outcomes Toolkit for Carers (ASCOT-Carer)

Background: The ASCOT-Carer is a self-report instrument designed to measure social care-related quality of life (SCRQoL). This article presents the psychometric testing and validation of the ASCOT-Carer four response-level interview (INT4) in a sample of unpaid carers of adults who receive publicly-funded social care services in England. Methods: Unpaid carers were identified through a survey of users of publicly-funded social care services in England. 387 carers completed a face-to-face or telephone interview. Data on variables hypothesised to be related to SCRQoL (for example, characteristics of the carer, cared-for person and care situation) and measures of carer experience, strain, health-related quality of life and overall QoL were collected. Relationships between these variables and overall SCRQoL score were evaluated through correlation, ANOVA and regression analysis to test the construct validity of the scale. Internal reliability was assessed using Cronbach’s alpha and feasibility by the number of missing responses. Results: The construct validity was supported by statistically significant relationships between SCRQoL and scores on instruments of related constructs, as well as with characteristics of the carer and care recipient in univariate and multivariate analyses. A Cronbach’s alpha of 0.87 (7 items) indicates that the internal reliability of the instrument is satisfactory and a low number of missing responses (<1%) indicates a high level of acceptance. Conclusions: The results provide evidence to support the construct validity, factor structure, internal reliability and feasibility of the ASCOT-Carer INT4 as an instrument for measuring social care-related quality of life of unpaid carers who care for adults with a variety of long-term conditions, disability or problems related to old age

Observations of mixed-species bird flocks at Kichwa Tembo Camp, Kenya

Mixed-species foraging flocks were studied at Kichwa Tembo Camp on the edge of the Masai Mara National Reserve in Kenya between July and September 2004. Observations were made on 29 mixed-species flocks, in which 24 species participated. African Paradise-Flycatcher Terpsiphone viridis, Black-backed Puffback Dryoscopus cubla, Grey-backed Camaroptera Camaroptera brachyura, Collared Sunbird Hedydipna collars and Cabanis's Greenbul Phyllastrephus cabanisi were the most common participants in mixed-species flocks, as well as among the most frequently encountered bird species overall. The Black-backed Puffback was identified as the nuclear species in flocks due to their abundance and frequency with which they were followed by other species. Mixed-species flocks represent another niche dimension in this diverse bird community, but few of these species could be described as flock specialists; most of the birds observed in mixed-species flocks in this study were opportunistic attendant species, including the African Pygmy-Kingfisher Ispidina picta, not previously described as joining mixed-species flocks