850 research outputs found
The Dispersal Ecology of Rhodesian Sleeping Sickness Following Its Introduction to a New Area
Tsetse-transmitted human and animal trypanosomiasis are constraints to both human and animal health in sub-Saharan Africa, and although these diseases have been known for over a century, there is little recent evidence demonstrating how the parasites circulate in natural hosts and ecosystems. The spread of Rhodesian sleeping sickness (caused by Trypanosoma brucei rhodesiense) within Uganda over the past 15 years has been linked to the movement of infected, untreated livestock (the predominant reservoir) from endemic areas. However, despite an understanding of the environmental dependencies of sleeping sickness, little research has focused on the environmental factors controlling transmission establishment or the spatially heterogeneous dispersal of disease following a new introduction. In the current study, an annually stratified case-control study of Rhodesian sleeping sickness cases from Serere District, Uganda was used to allow the temporal assessment of correlations between the spatial distribution of sleeping sickness and landscape factors. Significant relationships were detected between Rhodesian sleeping sickness and selected factors, including elevation and the proportion of land which was âseasonally flooding grasslandâ or âwoodlands and dense savannah.â Temporal trends in these relationships were detected, illustrating the dispersal of Rhodesian sleeping sickness into more âsuitableâ areas over time, with diminishing dependence on the point of introduction in concurrence with an increasing dependence on environmental and landscape factors. These results provide a novel insight into the ecology of Rhodesian sleeping sickness dispersal and may contribute towards the implementation of evidence-based control measures to prevent its further spread
Organizational factors and depression management in community-based primary care settings
Abstract Background Evidence-based quality improvement models for depression have not been fully implemented in routine primary care settings. To date, few studies have examined the organizational factors associated with depression management in real-world primary care practice. To successfully implement quality improvement models for depression, there must be a better understanding of the relevant organizational structure and processes of the primary care setting. The objective of this study is to describe these organizational features of routine primary care practice, and the organization of depression care, using survey questions derived from an evidence-based framework. Methods We used this framework to implement a survey of 27 practices comprised of 49 unique offices within a large primary care practice network in western Pennsylvania. Survey questions addressed practice structure (e.g., human resources, leadership, information technology (IT) infrastructure, and external incentives) and process features (e.g., staff performance, degree of integrated depression care, and IT performance). Results The results of our survey demonstrated substantial variation across the practice network of organizational factors pertinent to implementation of evidence-based depression management. Notably, quality improvement capability and IT infrastructure were widespread, but specific application to depression care differed between practices, as did coordination and communication tasks surrounding depression treatment. Conclusions The primary care practices in the network that we surveyed are at differing stages in their organization and implementation of evidence-based depression management. Practical surveys such as this may serve to better direct implementation of these quality improvement strategies for depression by improving understanding of the organizational barriers and facilitators that exist within both practices and practice networks. In addition, survey information can inform efforts of individual primary care practices in customizing intervention strategies to improve depression management.http://deepblue.lib.umich.edu/bitstream/2027.42/78269/1/1748-5908-4-84.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78269/2/1748-5908-4-84-S1.PDFhttp://deepblue.lib.umich.edu/bitstream/2027.42/78269/3/1748-5908-4-84.pdfPeer Reviewe
Biofilm formation at the solid-liquid and air-liquid interfaces by Acinetobacter species
Abstract
Background: The members of the genus Acinetobacter are Gram-negative cocobacilli that are frequently found in
the environment but also in the hospital setting where they have been associated with outbreaks of nosocomial
infections. Among them, Acinetobacter baumannii has emerged as the most common pathogenic species involved
in hospital-acquired infections. One reason for this emergence may be its persistence in the hospital wards, in
particular in the intensive care unit; this persistence could be partially explained by the capacity of these
microorganisms to form biofilm. Therefore, our main objective was to study the prevalence of the two main types
of biofilm formed by the most relevant Acinetobacter species, comparing biofilm formation between the different
species.
Findings: Biofilm formation at the air-liquid and solid-liquid interfaces was investigated in different Acinetobacter
spp. and it appeared to be generally more important at 25°C than at 37°C. The biofilm formation at the solid-liquid
interface by the members of the ACB-complex was at least 3 times higher than the other species (80-91% versus
5-24%). In addition, only the isolates belonging to this complex were able to form biofilm at the air-liquid interface;
between 9% and 36% of the tested isolates formed this type of pellicle. Finally, within the ACB-complex, the
biofilm formed at the air-liquid interface was almost 4 times higher for A. baumannii and Acinetobacter G13TU than
for Acinetobacter G3 (36%, 27% & 9% respectively).
Conclusions: Overall, this study has shown the capacity of the Acinetobacter spp to form two different types of
biofilm: solid-liquid and air-liquid interfaces. This ability was generally higher at 25°C which might contribute to
their persistence in the inanimate hospital environment. Our work has also demonstrated for the first time the
ability of the members of the ACB-complex to form biofilm at the air-liquid interface, a feature that was not
observed in other Acinetobacter species
First case of Anaplasma platys infection in a dog from Croatia
<p>Abstract</p> <p>Background</p> <p>It is known that <it>Anaplasma (A.) platys</it>, the causative agent of infectious canine cyclic thrombocytopenia, is endemic in countries of the Mediterranean basin. However, few reports are available from the Balkans. This case report describes a dog, which was imported from Croatia to Germany in May 2010. One month later the dog was presented to a local veterinarian in Germany due to intermittent/recurrent diarrhoea. Diagnostic tests were performed to identify infections caused by <it>Anaplasma </it>spp., <it>Ehrlichia </it>spp., <it>Hepatozoon canis, Babesia </it>spp., <it>Leishmania </it>spp., <it>Borrelia burgdorferi </it>and/or <it>Dirofilaria immitis</it>.</p> <p>Findings</p> <p>Haematological examination of a blood smear revealed basophilic inclusions in thrombocytes, which were confirmed as <it>A. platys </it>with a species-specific real-time PCR. Additionally, an infection with <it>Babesia (B.) vogeli </it>was also detected (PCR and serology). No specific antibodies against <it>Anaplasma </it>antigen were detectable. Although the dog showed no specific clinical signs, thrombocytopenia, anaemia and elevated C-reactive protein (CRP) were observed. Sequencing of a 1,348-bp partial ribosomal RNA gene revealed highest homology to <it>A. platys </it>sequences from Thailand, Japan and France.</p> <p>Conclusions</p> <p><it>A. platys </it>was detected for first time in a dog imported from Croatia. As the dog was also co-infected by <it>B. vogeli</it>, unique serological and haematological findings were recorded. Thrombocytopenia, anaemia and elevated values of C-reactive protein were the laboratory test abnormalities observed in this case. <it>A. platys </it>infections should be considered in dogs coming from Croatia and adjacent regions.</p
Compressed representation of a partially defined integer function over multiple arguments
In OLAP (OnLine Analitical Processing) data are analysed in an n-dimensional cube. The cube may be represented as a partially defined function over n arguments. Considering that often the function is not defined everywhere, we ask: is there a known way of representing the function or the points in which it is defined, in a more compact manner than the trivial one
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
X-ray emission from the Sombrero galaxy: discrete sources
We present a study of discrete X-ray sources in and around the
bulge-dominated, massive Sa galaxy, Sombrero (M104), based on new and archival
Chandra observations with a total exposure of ~200 ks. With a detection limit
of L_X = 1E37 erg/s and a field of view covering a galactocentric radius of ~30
kpc (11.5 arcminute), 383 sources are detected. Cross-correlation with Spitler
et al.'s catalogue of Sombrero globular clusters (GCs) identified from HST/ACS
observations reveals 41 X-rays sources in GCs, presumably low-mass X-ray
binaries (LMXBs). We quantify the differential luminosity functions (LFs) for
both the detected GC and field LMXBs, whose power-low indices (~1.1 for the
GC-LF and ~1.6 for field-LF) are consistent with previous studies for
elliptical galaxies. With precise sky positions of the GCs without a detected
X-ray source, we further quantify, through a fluctuation analysis, the GC LF at
fainter luminosities down to 1E35 erg/s. The derived index rules out a
faint-end slope flatter than 1.1 at a 2 sigma significance, contrary to recent
findings in several elliptical galaxies and the bulge of M31. On the other
hand, the 2-6 keV unresolved emission places a tight constraint on the field
LF, implying a flattened index of ~1.0 below 1E37 erg/s. We also detect 101
sources in the halo of Sombrero. The presence of these sources cannot be
interpreted as galactic LMXBs whose spatial distribution empirically follows
the starlight. Their number is also higher than the expected number of cosmic
AGNs (52+/-11 [1 sigma]) whose surface density is constrained by deep X-ray
surveys. We suggest that either the cosmic X-ray background is unusually high
in the direction of Sombrero, or a distinct population of X-ray sources is
present in the halo of Sombrero.Comment: 11 figures, 5 tables, ApJ in pres
Azimuthal anisotropy of charged particles at high transverse momenta in PbPb collisions at sqrt(s[NN]) = 2.76 TeV
The azimuthal anisotropy of charged particles in PbPb collisions at
nucleon-nucleon center-of-mass energy of 2.76 TeV is measured with the CMS
detector at the LHC over an extended transverse momentum (pt) range up to
approximately 60 GeV. The data cover both the low-pt region associated with
hydrodynamic flow phenomena and the high-pt region where the anisotropies may
reflect the path-length dependence of parton energy loss in the created medium.
The anisotropy parameter (v2) of the particles is extracted by correlating
charged tracks with respect to the event-plane reconstructed by using the
energy deposited in forward-angle calorimeters. For the six bins of collision
centrality studied, spanning the range of 0-60% most-central events, the
observed v2 values are found to first increase with pt, reaching a maximum
around pt = 3 GeV, and then to gradually decrease to almost zero, with the
decline persisting up to at least pt = 40 GeV over the full centrality range
measured.Comment: Replaced with published version. Added journal reference and DO
Search for new physics with same-sign isolated dilepton events with jets and missing transverse energy
A search for new physics is performed in events with two same-sign isolated
leptons, hadronic jets, and missing transverse energy in the final state. The
analysis is based on a data sample corresponding to an integrated luminosity of
4.98 inverse femtobarns produced in pp collisions at a center-of-mass energy of
7 TeV collected by the CMS experiment at the LHC. This constitutes a factor of
140 increase in integrated luminosity over previously published results. The
observed yields agree with the standard model predictions and thus no evidence
for new physics is found. The observations are used to set upper limits on
possible new physics contributions and to constrain supersymmetric models. To
facilitate the interpretation of the data in a broader range of new physics
scenarios, information on the event selection, detector response, and
efficiencies is provided.Comment: Published in Physical Review Letter
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