1,117 research outputs found

    The constant magnetic field of xi 1 CMa: geometry or slow rotation?

    Full text link
    We report recent observations of the sharp-lined magnetic beta Cep pulsator xi 1 CMa (= HD 46328). The longitudinal magnetic field of this star is detected consistently, but it is not observed to vary strongly, during nearly 5 years of observation. In this poster we evaluate whether the nearly constant longitudinal field is due to intrinsically slow rotation, or rather if the stellar or magnetic geometry is responsible

    Cd4 count levels and pattern of respiratory complications in hiv seropositive patients in calabar, Nigeria.

    Get PDF
    A prospective observational study was carried out to describe the pattern of pulmonary complications in hospitalized patients with Human Immune-deficiency Virus (HIV) infection at the University of Calabar Teaching Hospital, Calabar between January 2005 to December 2006. One hundred and twenty-four patients which consists 60 males and 64 females, aged between 20 – 60 who met the inclusion criteria formed the subjects for the study. The mean age of the subjects was 34.60+1.2 years. A structured questionnaire was used to obtain the demographic data, clinical information and CD4 lymphocyte count. Radiological analysis of chest was done with the chest X-ray of each subject. Chronic productive cough topped the list of respiratory symptoms (89%) followed by chest pain (74%) and dyspnea (62%). Lung consolidation was the commonest respiratory sign as seen in 44% of the cases. Hilar lymphadenopathy was seen in (35%), Pleural effusion (32%), lung fibrosis (21%) and finger clubbing (15%). The clinical and radiological pattern of most patients with chronic cough washighly suggestive of mycobacterial infection such as tuberculosis, although only 40% of cases had positive Acid Fast Baccilli. The mean CD4 lymphocyte count level was 174.8 + 5.4 cells/l and thismay be responsible for the respiratory findings as opportunistic lung infections are said to be commoner at CD4 count levels below 200 cells/l. However, four patients had mediasternal masseswhich may suggest neoplasms. Concerted efforts and continuous evaluation of these patients are needed to determine the spectrum of respiratory illnesses among HIV positive patients in Calabar

    Towards a framework for validating the matching between notifications and scents in olfactory in-car interaction

    Get PDF
    Olfactory notifications have been proven to have a positive impact on drivers. This has motivated the use of scents to convey driving-relevant information. Research has proposed the use of such scents as lemon, peppermint, lavender and rose for in-car notifications. However, there is no framework to identify which scent is the most suitable for every application scenario. In this paper, we propose an approach for validating a matching between scents and driving-relevant notifications. We suggest a study in which the olfactory modality is compared with a puff of clean air, visual, auditory, and tactile stimuli while performing the same driving task. For the data analysis, we suggest recording the lane deviation, speed, time required to recover from the error, as well as the perceived liking and comfort ratings. Our approach aims to help automotive UI designers make better decisions about choosing the most suitable scent, as well as possible alternative modalities

    Identification, distribution and prevalence of ecto-parasites associated with cultured fish in Ogun State, Nigeria

    Get PDF
    Public health issues can he considered as those of direct importance to both producers and consumers of fish and include broader issues of food production, processing and delivery systems. As aquaculture assumes an expanding role in meeting consumer demands for fish and fishery products, it is natural that they meet safety and quality standards. Aquaculture is a growing industry in Nigeria and it has assumed commercial importance activity. This study was part of the project on epizootiological survey of pathogenic diseases of cultured fish species and is aimed at identifying ecto-parasite associated with cultured fish in Ogun State, Nigeria. The study which was carried out in 2012 covered fifty fish farm, spread across the three senatorial zones. Five pieces of fish were randomly picked from each farm surveyed. Participants observation and structured questionnaires were administered to fish farmers in order to gather information on source of fries, fish feeding and feed type, use of manure and its type, pond type, stocking density, pond hygiene, water source, frequency of changing water and history of diseases and mortalities of fish. Before the fish samples were collected, pond size and physicochemical water quality were assessed. Water test kits were used to measure parameters like iron, nitrate, alkalinity and ammonia. All the procedures for physicochemical water quality parameter analysis was done according to the manufacturer's instructions. Water pH was measured using a probe while dissolved oxygen and both water as well as air temperature were measured by using Hanna kit. All types of farms are included in the survey such as hatcheries, brood stock farms as well as grow out farms. The study revealed the spread of parasites across the senatorial zones. The most common encountered parasites were Trichodina sp, Gyrodactylus sp, Dactylogyrus sp and trematodes. The intensity of the parasites differed markedly

    Resistance to three thrips species in <i>Capsicum</i> spp. depends on site conditions and geographic regions

    Get PDF
    Capsicum species are commercially grown for pepper production. This crop suffers severely from thrips damage and the identification of natural sources of thrips resistance is essential for the development of resistant cultivars. It is unclear whether resistance to Frankliniella occidentalis as assessed in a specific environment holds under different conditions. Additionally, other thrips species may respond differently to the plant genotypes. Screening for robust and general resistance to thrips encompasses testing different Capsicum accessions under various conditions and with different thrips species. We screened 11 Capsicum accessions (C. annuum and C. chinense) for resistance to F. occidentalis at three different locations in the Netherlands. Next, the same 11 accessions were screened for resistance to Thrips palmi and Scirtothrips dorsalis at two locations in Asia. This resulted in a unique analysis of thrips resistance in Capsicum at five different locations around the world. Finally, all accessions were also screened for resistance to F. occidentalis in the Netherlands using a leaf disc choice assay, allowing direct comparison of whole plant and leaf disc assays. Resistance to F. occidentalis was only partially consistent among the three sites in the Netherlands. The most susceptible accessions were consistently susceptible, but which accession was the most resistant differed among sites. In Asia, one C. chinense accession was particularly resistant to S. dorsalis and T. palmi, but this was not the most resistant accession to F. occidentalis. Overall, resistance to F. occidentalis correlated with S. dorsalis but not with T. palmi resistance in the C. annuum accessions. Damage inflicted on leaf discs reflected damage on the whole plant level. Our study showed that identifying broad spectrum resistance to thrips in Capsicum may prove to be challenging. Breeding programmes should focus on developing cultivars suitable for growing in defined geographic regions with specific thrips species and abiotic conditions

    Actinobacillus pleuropneumoniae serovar 8 predominates in England and Wales

    Get PDF
    This work was supported by a Longer and Larger (LoLa) grant from the Biotechnology and Biological Sciences Research Council (BBSRC grant numbers BB/G020744/1, BB/G019177/1, BB/G019274/1 and BB/G018553/1) and Zoetis (formerly Pfizer Animal Health) awarded to the Bacterial Respiratory Diseases of Pigs-1 Technology (BRaDP1T) Consortium

    Algebraic entropy in locally linearly compact vector spaces

    Get PDF
    We introduce algebraic entropy for continuous endomorphisms of locally linearly compact vector spaces over a discrete field, as a natural extension of the algebraic entropy for endomorphisms of discrete vector spaces studied in Giordano Bruno and Salce (Arab J Math 1:69\u201387, 2012). We show that the main properties continue to hold in the general context of locally linearly compact vector spaces, in particular we extend the Addition Theorem

    Insights into the function of silver as an oxidation catalyst by ab initio, atomistic thermodynamics

    Get PDF
    To help understand the high activity of silver as an oxidation catalyst, e.g., for the oxidation of ethylene to epoxide and the dehydrogenation of methanol to formaldehyde, the interaction and stability of oxygen species at the Ag(111) surface has been studied for a wide range of coverages. Through calculation of the free energy, as obtained from density-functional theory and taking into account the temperature and pressure via the oxygen chemical potential, we obtain the phase diagram of O/Ag(111). Our results reveal that a thin surface-oxide structure is most stable for the temperature and pressure range of ethylene epoxidation and we propose it (and possibly other similar structures) contains the species actuating the catalysis. For higher temperatures, low coverages of chemisorbed oxygen are most stable, which could also play a role in oxidation reactions. For temperatures greater than about 775 K there are no stable oxygen species, except for the possibility of O atoms adsorbed at under-coordinated surface sites Our calculations rule out thicker oxide-like structures, as well as bulk dissolved oxygen and molecular ozone-like species, as playing a role in the oxidation reactions.Comment: 15 pages including 9 figures, Related publications can be found at http://www.fhi-berlin.mpg.de/th/paper.htm
    • …
    corecore