212 research outputs found

    Numerical study of rainbows and glories in water-drop clouds

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    In this paper we study scattering phase functions in water-drop clouds for various distributions of droplet size and various conditions of glory, rainbow and corona formation, and discuss the hypothesis proposed by A. N. Nevzorov that a considerable amount of water in cold clouds can exist in a specific phase state with the refractive index ≈ 1.8 (so called A-water). Polarization and angular distributions are studied by the Monte Carlo method for radiation reflected by cloud layers with drops of water or hypothetical A-water taking into account multiple scattering. Computational results make it possible to develop procedures for analysis of microphysical structure of clouds and confirmation or disproof of the existence of A-water

    A retrospective review of Listeria monocytogenes infection at Tygerberg Children’s Hospital, Cape Town, South Africa, from 2006 to 2016: Is empirical ampicillin still indicated after the first month of life?

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    Background. Ampicillin to treat Listeria monocytogenes (LM) infection is empirically added to the treatment of infants (<3 months) with suspected sepsis or meningitis.Objectives. In view of limited LM cases, the paucity of South African (SA) data and an ampicillin shortage, our objective was to describe the occurrence of LM infections at Tygerberg Hospital (TBH), Cape Town, with the aim of rationalising the paediatric antibiotic policy.Methods. An 11-year (2006 - 2016) retrospective descriptive study of children (<13 years) from TBH and referral hospitals with a positive blood or cerebrospinal fluid (CSF) culture for LM was conducted.Results. Of 26 children with positive cultures for LM, 23 (88.5%) were <3 months of age; all were <10 days old. Approximately half (56.5%, 13/23) were born at or referred to TBH. Presentation was on the day of delivery in 46.2% (6/13), 92.3% were admitted to the neonatal intensive care unit (NICU), and 61.5% (8/13) died. Neonates treated at peripheral hospitals were statistically more likely than those treated at TBH to have a CSF culture obtained (90.0% v. 30.8%; p=0.005), and had higher platelet counts (239 × 109/L v. 107 × 109/L; p=0.004), lower C-reactive protein levels (64 mg/L v. 137 mg/L; p=0.013) and a lower mortality rate (0% v. 61.5%; p=0.002). The incidence of LM at TBH was 0.04/1 000 live births and 2.3/1 000 NICU admissions.Conclusions. As in other countries, the local neonatal LM incidence is low. Neonates present in the first week of life with severe disease and a high mortality rate. These data support a change in antibiotic policy, in keeping with international guidelines, limiting empirical ampicillin prescription to infants <1 month of age.

    Numerical study of rainbows and glories in water-drop clouds

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    In this paper we study scattering phase functions in water-drop clouds for various distributions of droplet size and various conditions of glory, rainbow and corona formation, and discuss the hypothesis proposed by A. N. Nevzorov that a considerable amount of water in cold clouds can exist in a specific phase state with the refractive index ≈ 1.8 (so called A-water). Polarization and angular distributions are studied by the Monte Carlo method for radiation reflected by cloud layers with drops of water or hypothetical A-water taking into account multiple scattering. Computational results make it possible to develop procedures for analysis of microphysical structure of clouds and confirmation or disproof of the existence of A-water

    Conception and pilot testing of a self-management health application for patients with pollen-related allergic rhinitis and allergic asthma-the APOLLO app

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    Abstract It has been shown that pollen information services are an important self-management tool for patients with pollen-related allergic rhinitis (AR) and allergic asthma (AA). This study aimed to design an online application for patients with AR and AA, which supports patients to better manage their disease as well as to evaluate the app and present the first results of the pilot study. The pollen data were obtained from the electronic pollen information network of Bavaria, Germany. Participants were asked to fill in their allergy-related complaints in the app over a 60-day period. Subsequently, the app was evaluated. Indices and diagrams visualized the participants’ individual complaints as well as the daily pollen concentration in the air. In order to motivate participants to complete the app on a daily basis, we used elements of gamification. Two thirds of the participants (N = 46) reported feeling better informed about pollen counts and their allergy when using the app. The app's simple and comprehensible design was rated positively. More than 80% of the participants would recommend the app to their family and friends. The app can be a tool for patients with AR and AA to better understand their disease

    Clinical pharmacology becomes a specialty in South Africa

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    South Africa recently became the first African country where clinical pharmacology has been approved as a specialty. This article outlines the need for clinical pharmacologists, their role in advancing public health, the potential benefits to the country, and recommendations for ensuring a healthy future for the discipline.http://www.samj.org.zaam2014ay201

    Clinical pharmacology becomes a specialty in South Africa

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    South Africa recently became the first African country where clinical pharmacology has been approved as a specialty. This article outlines the need for clinical pharmacologists, their role in advancing public health, the potential benefits to the country, and recommendations for ensuring a healthy future for the discipline.http://www.samj.org.zaam2014ay201

    Effects of habitat and land use on breeding season density of male Asian Houbara Chlamydotis macqueenii

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    Landscape-scale habitat and land-use influences on Asian Houbara Chlamydotis macqueenii (IUCN Vulnerable) remain unstudied, while estimating numbers of this cryptic, low-density, over-hunted species is challenging. In spring 2013, male houbara were recorded at 231 point counts, conducted twice, across a gradient of sheep density and shrub assemblages within 14,300 km² of the Kyzylkum Desert, Uzbekistan. Four sets of models related male abundance to: (1) vegetation structure (shrub height and substrate); (2) shrub assemblage; (3) shrub species composition (multidimensional scaling); (4) remote-sensed derived land-cover (GLOBCOVER, 4 variables). Each set also incorporated measures of landscape rugosity and sheep density. For each set, multi-model inference was applied to generalised linear mixed models of visit-specific counts that included important detectability covariates and point ID as a random effect. Vegetation structure received strongest support, followed by shrub species composition and shrub assemblage, with weakest support for the GLOBCOVER model set. Male houbara numbers were greater with lower mean shrub height, more gravel and flatter surfaces, but were unaffected by sheep density. Male density (mean 0.14 km-2, 95% CI, 0.12‒0.15) estimated by distance analysis differed substantially among shrub assemblages, being highest in vegetation dominated by Salsola rigida (0.22 [CI, 0.20‒0.25]), high in areas of S. arbuscula and Astragalus (0.14 [CI, 0.13‒0.16] and 0.15 [CI, 0.14‒0.17] respectively), lower (0.09 [CI, 0.08‒0.10]) in Artemisia and lowest (0.04 [CI, 0.04‒0.05]) in Calligonum. The study area was estimated to hold 1,824 males (CI: 1,645‒2,030). The spatial distribution of relative male houbara abundance, predicted from vegetation structure models, had the strongest correspondence with observed numbers in both model-calibration and the subsequent year’s data. We found no effect of pastoralism on male distribution but potential effects on nesting females are unknown. Density differences among shrub communities suggest extrapolation to estimate country- or range-wide population size must take account of vegetation composition

    The generality of the GUGA MRCI approach in COLUMBUS for treating complex quantum chemistry

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    The core part of the program system COLUMBUS allows highly efficient calculations using variational multireference (MR) methods in the framework of configuration interaction with single and double excitations (MR-CISD) and averaged quadratic coupled-cluster calculations (MR-AQCC), based on uncontracted sets of configurations and the graphical unitary group approach (GUGA). The availability of analytic MR-CISD and MR-AQCC energy gradients and analytic nonadiabatic couplings for MR-CISD enables exciting applications including, e.g., investigations of π-conjugated biradicaloid compounds, calculations of multitudes of excited states, development of diabatization procedures, and furnishing the electronic structure information for on-the-fly surface nonadiabatic dynamics. With fully variational uncontracted spin-orbit MRCI, COLUMBUS provides a unique possibility of performing high-level calculations on compounds containing heavy atoms up to lanthanides and actinides. Crucial for carrying out all of these calculations effectively is the availability of an efficient parallel code for the CI step. Configuration spaces of several billion in size now can be treated quite routinely on standard parallel computer clusters. Emerging developments in COLUMBUS, including the all configuration mean energy multiconfiguration self-consistent field method and the graphically contracted function method, promise to allow practically unlimited configuration space dimensions. Spin density based on the GUGA approach, analytic spin-orbit energy gradients, possibilities for local electron correlation MR calculations, development of general interfaces for nonadiabatic dynamics, and MRCI linear vibronic coupling models conclude this overview

    Habitat preferences of Phoebetria albatrosses in sympatry and allopatry

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    Aim: Competition is often proposed to drive niche segregation along multiple axes in speciose communities. Understanding spatial partitioning of foraging areas is particularly important in species that are constrained to a central place. We present a natural experiment examining variation in habitat preferences of congeneric Southern Ocean predators in sympatry and allopatry. Our aim was to ascertain consistency of habitat preferences within species, and to test whether preferences changed in the presence of the congener. Location: Southern Hemisphere. Taxon: Multiple colonies of both species within the genus Phoebetria (sooty albatrosses). Methods: The two Phoebetria albatrosses breed on islands located from ~37–55°S – sooty albatrosses (P. fusca) in the north and light-mantled albatrosses (P. palpebrata) in the south – with sympatric overlap at locations ~46–49°S. We analysed GPS and PTT tracks from 87 individuals and multiple remotely sensed environmental variables using GAMs, to determine and compare the key factors influencing habitat preference for each species at each breeding colony. Results While foraging habitat preferences are consistent in light-mantled albatrosses, there is divergence of preferences in sooty albatrosses depending on whether they are in sympatry with their congener or in allopatry. Main Conclusions This study represents the most comprehensive work on this genus to date and highlights how habitat preferences and behavioural plasticity may influence species distributions under different competitive conditions

    Anaphylaxis in Elderly Patients-Data From the European Anaphylaxis Registry

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    Background: Elicitors and symptoms of anaphylaxis are age dependent. However, little is known about typical features of anaphylaxis in patients aged 65 years or more. Methods: The data from the Network for Online Registration of Anaphylaxis (NORA) considering patients aged ≥65 (elderly) in comparison to data from adults (18–64 years) regarding elicitors, symptoms, comorbidities, and treatment measures were analyzed. Results: We identified 1,123 elderly anaphylactic patients. Insect venoms were the most frequent elicitor in this group (p < 0.001), followed by drugs like analgesics and antibiotics. Food allergens elicited less frequently anaphylaxis (p < 0.001). Skin symptoms occurred less frequently in elderly patients (77%, p < 0.001). The clinical symptoms were more severe in the elderly (51% experiencing grade III/IV reactions), in particular when skin symptoms (p < 0.001) were absent. Most strikingly, a loss of consciousness (33%, p < 0.001) and preexisting cardiovascular comorbidity (59%, p < 0.001) were more prevalent in the elderly. Finally, adrenaline was used in 30% of the elderly (vs. 26% in the comparator group, p < 0.001) and hospitalization was more often required (60 vs. 50%, p < 0.001). Discussion and Conclusion: Anaphylaxis in the elderly is often caused by insect venoms and drugs. These patients suffer more often from cardiovascular symptoms, receive more frequently adrenaline and require more often hospitalization. The data indicate that anaphylaxis in the elderly tends to be more frequently life threatening and patients require intensified medical intervention. The data support the need to recognize anaphylaxis in this patient group, which is prone to be at a higher risk for a fatal outcome
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