1,503 research outputs found
Population genetic analysis of Bartonella bacilliformis isolates from areas of Peru where Carrion\u27s disease is endemic and epidemic
Carrion's disease is caused by infection with the α-proteobacterium Bartonella bacilliformis. Distribution of the disease is considered coincident with the distribution of its known vector, the sand fly Lutzomyia verrucarum. Recent epidemics of B. bacilliformis infections associated with atypical symptomatology in nonendemic regions have raised questions regarding the historic and present distribution of this bacterium and the scope of disease that infection causes. Phylogenetic relationships and genomic diversity of 18 B. bacilliformis isolates (10 isolates from a region where Carrion's disease is epidemic, Cuzco, Peru, and 8 isolates from a region where Carrion's disease is endemic, Caraz, Peru) were assessed using genomic data generated by infrequent restriction site PCR and gene sequence analysis of the flagellin gltA and ialB genes. A population genetic analysis of the genomic diversity suggests that what was once considered an epidemic region of Peru did not result from the recent introduction of B. bacilliformis
Dietary Habits of the Common Rodents in an Agrecosystem in Argentina
Dietary habits of five common rodents in agroecosystems on the central Argentine Pampa were studied for 15 months using microhistological analysis of stomach contents. All five rodent species were omnivorous, but proportions of major dietary items (arthropods, dicot leaves and seeds, monocot leaves and seeds) varied among species and seasons. Akodon azarae largely was entomophagous; arthropods formed 41-62% of the diet in all seasons. The other four species (Calomys musculinus, Calomys laucha, Bolomys obscurus, and Oligoryzomys flavescens) consumed most diet items throughout the year, but relative proportions varied among seasons. Leaves formed a relatively minor proportion of the diet (12- 16% overall for all species) throughout the year. All species except A. azarae consumed higher quantities of seeds (50-73% of stomach volume) than arthropods (15-35%) during autumn and winter but switched to higher quantities of arthropods (30-53%) in spring and summer. Diet breadth was narrower and overlap generally highest during winter when all species were forced to subsist on a reduced set of available resources. Of 28 plant species with \u3e2% cover in the environment, 25 were identified in stomachs of one or more of the five rodent species. The most important plant species in the diet were corn and soybeans (mostly grain), seed of Johnson grass (Sorghum halepense), chickweed (Stellaria media), and Amaranthus. High consumption of arthropods, especially by A. azarae, contraindicates the broad-scale use of rodenticides until the role of that rodent species in the control of pest insects can be ascertained
Dietary Habits of the Common Rodents in an Agrecosystem in Argentina
Dietary habits of five common rodents in agroecosystems on the central Argentine Pampa were studied for 15 months using microhistological analysis of stomach contents. All five rodent species were omnivorous, but proportions of major dietary items (arthropods, dicot leaves and seeds, monocot leaves and seeds) varied among species and seasons. Akodon azarae largely was entomophagous; arthropods formed 41-62% of the diet in all seasons. The other four species (Calomys musculinus, Calomys laucha, Bolomys obscurus, and Oligoryzomys flavescens) consumed most diet items throughout the year, but relative proportions varied among seasons. Leaves formed a relatively minor proportion of the diet (12- 16% overall for all species) throughout the year. All species except A. azarae consumed higher quantities of seeds (50-73% of stomach volume) than arthropods (15-35%) during autumn and winter but switched to higher quantities of arthropods (30-53%) in spring and summer. Diet breadth was narrower and overlap generally highest during winter when all species were forced to subsist on a reduced set of available resources. Of 28 plant species with \u3e2% cover in the environment, 25 were identified in stomachs of one or more of the five rodent species. The most important plant species in the diet were corn and soybeans (mostly grain), seed of Johnson grass (Sorghum halepense), chickweed (Stellaria media), and Amaranthus. High consumption of arthropods, especially by A. azarae, contraindicates the broad-scale use of rodenticides until the role of that rodent species in the control of pest insects can be ascertained
Molecular Epidemiology of Tuberculosis in a Sentinel Surveillance Population
We conducted a population-based study to assess demographic and risk-factor correlates for the most frequently occurring Mycobacterium tuberculosis genotypes from tuberculosis (TB) patients. The study included all incident, culture-positive TB patients from seven sentinel surveillance sites in the United States from 1996 to 2000. M. tuberculosis isolates were genotyped by IS6110-based restriction fragment length polymorphism and spoligotyping. Genotyping was available for 90% of 11,923 TB patients. Overall, 48% of cases had isolates that matched those from another patient, including 64% of U.S.-born and 35% of foreign-born patients. By logistic regression analysis, risk factors for clustering of genotypes were being male, U.S.-born, black, homeless, and infected with HIV; having pulmonary disease with cavitations on chest radiograph and a sputum smear with acid-fast bacilli; and excessive drug or alcohol use. Molecular characterization of TB isolates permitted risk correlates for clusters and specific genotypes to be described and provided information regarding cluster dynamics over time
The relationship among diet, alimentary tract morphology, and life history for five species of rodents from the central Argentine pampa
Development of a caregiver-reported measure to support systematic assessment of people with dementia in long-term care: The Integrated Palliative care Outcome Scale for Dementia
Background:Symptom burden is common for long-term care residents with dementia which if untreated compromises quality of life. Measurement tools can support assessment of symptoms and problems but are not widely used in long-term care settings. We developed the Integrated Palliative care Outcome Scale for Dementia derived from the Palliative care Outcome Scale, Palliative care Outcome Scale–Symptom and Integrated Palliative care Outcome Scale.Aim:To examine the content validity, acceptability and comprehension of Integrated Palliative care Outcome Scale for Dementia for routine use in long-term care settings for people with dementia and to refine Integrated Palliative care Outcome Scale for Dementia.Design:A multi-method qualitative study consisting of focus groups, semi-structured interviews and cognitive interviews.Setting/participants:Three residential long-term care settings in London, UK. Focus group and semi-structured interview participants included caregiver staff, family, general practitioners and district nurses. Caregiver staff were sampled purposively for cognitive interviews.Results:A total of 26 respondents participated in the focus groups (n = 21) or semi-structured interviews (n = 5) and 10 caregiver staff completed cognitive interviews. Additional symptoms and problems included agitation, wandering, sleep problems, communication problems and diarrhoea. Refinements or lay terms were required to improve comprehension and consistency of item response for nausea, drowsiness, delusions/hallucinations, agitation, loss of interest, communication problems and interaction. A video presentation was required to support comprehension of instructions and assessment of verbally compromised residents.Conclusion:Integrated Palliative care Outcome Scale for Dementia is a comprehensive and acceptable caregiver-reported measure to detect symptoms and problems in dementia. It is suitable for caregiver staff without professional training as it has been refined and tailored to maximise caregiver expertise, ready for further psychometric testing
Supersymmetric Scenarios with Dominant Radiative Neutralino Decay
The radiative decay of the next-to-lightest neutralino into a lightest
neutralino and a photon is analyzed in the MSSM. We find that significant
regions of the supersymmetric parameter space with large radiative BR's (up to
about 100%) do exist. The radiative channel turns out to be enhanced when the
neutralino tree-level decays are suppressed either "kinematically" or
"dynamically". In general, in the regions allowed by LEP data and not
characterized by asymptotic values of the SuSy parameters, the radiative
enhancement requires tan beta ~= 1 and/or M_1 ~= M_2, and negative values of
\mu. We present typical specific scenarios where these "necessary" conditions
are fulfilled, relaxing the usual relation M_1=(5/3)*tan^2(th_W)*M_2. The
influence of varying the stop masses and mixing angle when the radiative decay
is enhanced is also considered. Some phenomenological consequences of the above
picture are discussed.Comment: 32 pages, LaTeX file + 23 figures embedded with epsf.sty. In this
revised version, Eq.(3) plus some related notations and text passages have
been changed. Minor error corrected in Fig.12(a). The numerical analysis and
the conclusions of the paper are not affected. (Includes the erratum to
appear in Phys. Rev. D.) Source and ps files are also available at
ftp://hpteo.roma1.infn.it/pub/preprints/ambr-mele/Rome1-1148/ or at
http://feynman.physics.lsa.umich.edu/~ambros/Physics.html#1
An illustrative analysis of atypical gas production profiles obtained from in vitro digestibility studies using fecal inoculum
14 páginas, 2 tablas, 6 figuras.Gas production profiles typically show a monotonically increasing monophasic pattern.
However, atypical gas production profiles exist whereby at least two consecutive phases of gas
production or additional extraneous features that distort the typical profile are present. Such profiles are more likely to occur with the use of a fecal inoculum and are much less well described.
The presence of multiple phases or non-descript extraneous features makes it difficult to apply
directly recommended modeling approaches such as standard response functions or classical growth
functions. To overcome such difficulties, extensions of the Mitscherlich equation and a numerical
modeling option also based on the Mitscherlich are explored. The numerical modeling option uses
an estimate of relative rate obtained from the smoothed data profile and an estimate of maximum
gas produced together with any lag time information drawn from the raw data to construct a simple
Mitscherlich equation. In summary, this article illustrates the analysis of atypical gas production
profiles obtained using a fecal inoculum and explores the methodology of numerical modeling to
reconstruct equivalent typical growth-like trends.This research was funded in part by The Canada Research Chairs program, grant number
045867 (Natural Sciences and Engineering Research Council of Canada, Ottawa)
Neutralino Decays in the Minimal Supersymmetric Standard Model
A complete phenomenological study of the next-to-lightest neutralino decays
is performed in the MSSM. The widths and branching ratios for all the possible
decay channels (including the radiative decay X0(2) --> X0(1) gamma and the
decay into a light Higgs X0(2) --> X0(1) h0) are studied in detail as functions
of all the SuSy parameters of the model. Particular attention is paid to
situations that are interesting for LEP2 searches. Non-trivial decay patterns
are found that critically depend on the region of the parameter space
considered.Comment: 29 pages, no figures, REVTeX. A gzipped postscript file of the
complete paper (50 pages, 31 figs) is available via anonymous ftp at
ftp://hpteo.roma1.infn.it/pub/preprints/ambr-mele/Rome1-1095.ps.gz (1 Mb -->
5.6 Mb
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