89 research outputs found
First record of Chiasmognathus from the Kingdom of Saudi Arabia (Hymenoptera, Apidae)
This is the publisher's version, also available electronically from http://www.pensoft.net/journals/jhr/article/5841/first-record-of-chiasmognathus-from-the-kingdom-of-saudi-arabia-hymenoptera-apidae-The cleptoparasitic bee genus Chiasmognathus Engel (Nomadinae: Ammobatini) is recorded from Saudi Arabia for the first time. Chiasmognathus nearchus Engel was previously known from specimens collected in the United Arab Emirates and Oman. Here we report and figure two individuals captured in central Saudi Arabia
Nesting Biology of the Leafcutting Bee Megachile minutissima (Hymenoptera: Megachilidae) in Central Saudi Arabia
The leafcutting bee Megachile (Eutricharaea) minutissima Radoszkowski is a widely distributed species in the Middle East and a promising pollinator of alfalfa. We provide information on the nest architecture, foraging behavior, phenology, and host plants of a wild population of M. minutissima studied between March 2010 and September 2012 in Amariah, a typical desert in central Saudi Arabia. Bees nested in preexisting cavities in the sandy, dry, and loose soil, and built between 2 and 14 leaf-lined brood cells per nest. Females built and provisioned 1-2 cells per day, each consisting of a large oval piece from which the cell cup was made and a small semiround piece that was used as cell cap; however, occasionally small oval pieces were also used in the latter. Cells were built from leaves of Ricinus communis L. (Euphorbiaceae), a locally abundant plant. Both sexes were captured from March to October at flowers of 11 species (10 families), indicating some degree of polylecty as well as either bivoltinism or multivoltinism. We also provide comparative taxonomic comments that will assist bee researchers to easily recognize this species
A new species of Chalicodoma from Saudi Arabia with modified facial setae (Hymenoptera, Megachilidae)
Some bees and pollen wasps have independently evolved simple, stiff, erect, apically-curved, curly or hooked facial setae as adaptations to collect pollen from nototribic flowers. A distinctive new species of Chalicodoma Lepeletier de Saint Fargeau subgenus Pseudomegachile Friese from Saudi Arabia with such morphological adaptations, C. riyadhense sp. n., is described and figured. The species was captured visiting flowers of Blepharis ciliaris (L.) (Acanthaceae). The occurrence of modified facial setae is documented and
discussed for the first time in eight other species of Pseudomegachile, and a key to the genera and subgenera of Megachilini currently confirmed for Saudi Arabia is provided
Single and Multi-Sources Energy Sizing for Electric Vehicle: A Case Study
The automotive industry has introduced various renewable-energy based technologies such as battery electric vehicles (BEV) and fuel-cell electric vehicles (FCEV). However the main concern is addressing issues to determine which vehicle with different energy sources are more efficiency and cost saving than the others. In order to overcome this issue detailed analysis need to be performed on the important criterions in vehicle sizing like energy cost, dissipated energy and effective energy source (EES). This paper deals with the modeling, evaluation and analysis of single and multi-source electric vehicle (EV) on three classes of EV, namely the light electric vehicle (LEV), medium electric vehicle (MEV) and electric vehicle (EV). A comparison on dissipated energy with different EES, charging cost and weight were made based on a linear mathematical calculation. The results have shown that multi-sources energy powered-vehicle deliver among the best dissipated energy and EES percentage. Findings of this energy sizing under various combination of EV would be helpful for further research on the EV energy applications
Rediscovered parasitism of Andrena savignyi Spinola (Hymenoptera, Andrenidae) by Stylops (Strepsiptera, Stylopidae) and revised taxonomic status of the parasite
Parasitism of Andrena (Suandrena) savignyi Spinola (Hymenoptera: Andrenidae) by Stylops Kirby (Strepsiptera: Stylopidae) has been recorded only once, and from an individual collected in Egypt almost a century ago, with the parasite described as Stylops savignyi Hofeneder. The recent rediscovery of this Stylops from an individual of Andrena savignyi permits a reinterpretation of the species and its affinities among other Stylops. The bee was collected at flowers of Zilla spinosa (Turra) Prantl. (Brassicaceae) in Amariah, Riyadh, Kingdom of Saudi Arabia. Based on DNA barcode sequences from material sampled across Africa, Asia, and Europe, it is apparent that Stylops savignyi is conspecific with Stylops nassonowi Pierce, and we accordingly synonymize this name (syn. n.), with the latter representing the senior and valid name for the species. A differential diagnosis is provided for Stylops nassonowi and the morphology of the female is described, as well as the first instars
Rediscovered parasitism of Andrena savignyi Spinola (Hymenoptera, Andrenidae) by Stylops (Strepsiptera, Stylopidae) and revised taxonomic status of the parasite
Parasitism of Andrena (Suandrena) savignyi Spinola (Hymenoptera: Andrenidae) by Stylops Kirby (Strepsiptera: Stylopidae) has been recorded only once, and from an individual collected in Egypt almost a century ago, with the parasite described as Stylops savignyi Hofeneder. The recent rediscovery of this Stylops from an individual of Andrena savignyi permits a reinterpretation of the species and its affinities among other Stylops. The bee was collected at flowers of Zilla spinosa (Turra) Prantl. (Brassicaceae) in Amariah, Riyadh, Kingdom of Saudi Arabia. Based on DNA barcode sequences from material sampled across Africa, Asia, and Europe, it is apparent that Stylops savignyi is conspecific with Stylops nassonowi Pierce, and we accordingly synonymize this name (syn. n.), with the latter representing the senior and valid name for the species. A differential diagnosis is provided for Stylops nassonowi and the morphology of the female is described, as well as the first instars
Case-mix and the use of control charts in monitoring mortality rates after coronary artery bypass
BACKGROUND: There is debate about the role of crude mortality rates and case-mix adjusted mortality rates in monitoring the outcomes of treatment. In the context of quality improvement a key purpose of monitoring is to identify special cause variation as this type of variation should be investigated to identify possible causes. This paper investigates agreement between the identification of special cause variation in risk adjusted and observed hospital specific mortality rates after coronary artery bypass grafting in New York hospitals. METHODS: Coronary artery bypass grafting mortality rates between 1994 and 2003 were obtained from the New York State Department of Health's cardiovascular reports for 41 hospitals. Cross-sectional control charts of crude (observed) and risk adjusted mortality rates were produced for each year. Special cause variation was defined as a data point beyond the 99.9% probability limits: hospitals showing special cause variation were identified for each year. Longitudinal control charts of crude (observed) and risk adjusted mortality rates were produced for each hospital with data for all ten years (n = 27). Special cause variation was defined as a data point beyond 99.9% probability limits, two out of three consecutive data points beyond 95% probability limits (two standard deviations from the mean) or a run of five consecutive points on one side of the mean. Years showing special cause variation in mortality were identified for each hospital. Cohen's Kappa was calculated for agreement between special causes identified in crude and risk-adjusted control charts. RESULTS: In cross sectional analysis the Cohen's Kappa was 0.54 (95% confidence interval: 0.28 to 0.78), indicating moderate agreement between the crude and risk-adjusted control charts with sensitivity 0.4 (95% confidence interval 0.17–0.69) and specificity 0.98 (95% confidence interval: 0.95–0.99). In longitudinal analysis, the Cohen's Kappa was 0.61 (95% confidence interval: 0.39 to 0.83) indicating good agreement between the tests with sensitivity 0.63 (95% confidence interval: 0.39–0.82) and specificity 0.98 (95% confidence interval: 0.96 to 0.99). CONCLUSION: There is moderate-good agreement between signals of special cause variation between observed and risk-adjusted mortality. Analysis of observed hospital specific CABG mortality over time and with other hospitals appears to be useful in identifying special causes of variation. Case-mix adjustment may not be essential for longitudinal monitoring of outcomes using control charts
The genome-wide multi-layered architecture of chromosome pairing in early Drosophila embryos
Genome organization involves cis and trans chromosomal interactions, both implicated in gene regulation, development, and disease. Here, we focus on trans interactions in Drosophila, where homologous chromosomes are paired in somatic cells from embryogenesis through adulthood. We first address long-standing questions regarding the structure of embryonic homolog pairing and, to this end, develop a haplotype-resolved Hi-C approach to minimize homolog misassignment and thus robustly distinguish trans-homolog from cis contacts. This computational approach, which we call Ohm, reveals pairing to be surprisingly structured genome-wide, with trans-homolog domains, compartments, and interaction peaks, many coinciding with analogous cis features. We also find a significant genome-wide correlation between pairing, transcription during zygotic genome activation, and binding of the pioneer factor Zelda. Our findings reveal a complex, highly structured organization underlying homolog pairing, first discovered a century ago in Drosophila. Finally, we demonstrate the versatility of our haplotype-resolved approach by applying it to mammalian embryos
Avian Influenza Outbreaks in Chickens, Bangladesh
To determine the epidemiology of outbreaks of avian influenza A virus (subtypes H5N1, H9N2) in chickens in Bangladesh, we conducted surveys and examined virus isolates. The outbreak began in backyard chickens. Probable sources of infection included egg trays and vehicles from local live bird markets and larger live bird markets
What is the empirical evidence that hospitals with higher-risk adjusted mortality rates provide poorer quality care? A systematic review of the literature
<p>Abstract</p> <p>Background</p> <p>Despite increasing interest and publication of risk-adjusted hospital mortality rates, the relationship with underlying quality of care remains unclear. We undertook a systematic review to ascertain the extent to which variations in risk-adjusted mortality rates were associated with differences in quality of care.</p> <p>Methods</p> <p>We identified studies in which risk-adjusted mortality and quality of care had been reported in more than one hospital. We adopted an iterative search strategy using three databases – Medline, HealthSTAR and CINAHL from 1966, 1975 and 1982 respectively. We identified potentially relevant studies on the basis of the title or abstract. We obtained these papers and included those which met our inclusion criteria.</p> <p>Results</p> <p>From an initial yield of 6,456 papers, 36 studies met the inclusion criteria. Several of these studies considered more than one process-versus-risk-adjusted mortality relationship. In total we found 51 such relationships in a widen range of clinical conditions using a variety of methods. A positive correlation between better quality of care and risk-adjusted mortality was found in under half the relationships (26/51 51%) but the remainder showed no correlation (16/51 31%) or a paradoxical correlation (9/51 18%).</p> <p>Conclusion</p> <p>The general notion that hospitals with higher risk-adjusted mortality have poorer quality of care is neither consistent nor reliable.</p
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