414 research outputs found
Smooth plug-in inverse estimators in the current status continuous mark model
We consider the problem of estimating the joint distribution function of the
event time and a continuous mark variable when the event time is subject to
interval censoring case 1 and the continuous mark variable is only observed in
case the event occurred before the time of inspection. The nonparametric
maximum likelihood estimator in this model is known to be inconsistent. We
study two alternative smooth estimators, based on the explicit (inverse)
expression of the distribution function of interest in terms of the density of
the observable vector. We derive the pointwise asymptotic distribution of both
estimators.Comment: 29 pages, 12 figure
Maximum smoothed likelihood estimation and smoothed maximum likelihood estimation in the current status model
We consider the problem of estimating the distribution function, the density
and the hazard rate of the (unobservable) event time in the current status
model. A well studied and natural nonparametric estimator for the distribution
function in this model is the nonparametric maximum likelihood estimator (MLE).
We study two alternative methods for the estimation of the distribution
function, assuming some smoothness of the event time distribution. The first
estimator is based on a maximum smoothed likelihood approach. The second method
is based on smoothing the (discrete) MLE of the distribution function. These
estimators can be used to estimate the density and hazard rate of the event
time distribution based on the plug-in principle.Comment: Published in at http://dx.doi.org/10.1214/09-AOS721 the Annals of
Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical
Statistics (http://www.imstat.org
A maximum smoothed likelihood estimator in the current status continuous mark model
We consider the problem of estimating the joint distribution function of the
event time and a continuous mark variable based on censored data. More
specifically, the event time is subject to current status censoring and the
continuous mark is only observed in case inspection takes place after the event
time. The nonparametric maximum likelihood estimator (MLE) in this model is
known to be inconsistent. We propose and study an alternative likelihood based
estimator, maximizing a smoothed log-likelihood, hence called a maximum
smoothed likelihood estimator (MSLE). This estimator is shown to be well
defined and consistent, and a simple algorithm is described that can be used to
compute it. The MSLE is compared with other estimators in a small simulation
study.Comment: 24 pages, 6 figure
African Heritage Design
Prenant comme point de dĂ©part lâarĂšne patrimoniale historiquement constituĂ©e au Ghana, et plus particuliĂšrement les acteurs clĂ©s de cette arĂšne et les conflits entre eux, les auteurs explorent la pluralitĂ© et les dynamiques de la construction du âpatrimoine culturelâ dans ce pays. Plusieurs domaines â Ă©tat, religion, media de loisir â et tendances dans la construction du passĂ© culturel se rencontrent : la mobilisation du âpatrimoineâ par lâĂ©tat dans le cadre des politiques dâidentitĂ© nationale, la contestation de ce projet Ă©tatique par les Ă©glises pentecĂŽtistes qui considĂšrent le âpatrimoineâ comme dangereux et satanique, et la valorisation du âpatrimoineâ comme style esthĂ©tique dans les vidĂ©os prĂ©sentĂ©es par les tĂ©lĂ©visions locales. Les tendances Ă©conomiques rĂ©centes visant Ă donner une image plus positive du âpatrimoine africainâ sâancrent dans des initiatives publiques antĂ©rieures et sâappuient sur la notion de style et de design visuel. Ainsi, ces tendances posent de nouvelles questions sur les liens entre patrimoine et esthĂ©tique visuelle, et impliquent une comprĂ©hension du patrimoine culturel prenant en compte les questions de style, de design et de commercialisation.This paper explores the plurality and dynamics of âcultural heritageâ formation in Ghana by looking at key players in the historically constituted heritage arena and the contestations between them. Focusing on the intersecting domains of the state, religion, and entertainment media, it discerns several tendencies with regard to the framing of cultural pasts : mobilization of âheritageâ by the state as part of national identity politics ; contestation of this state project by Pentecostal churches that view âheritageâ as demonic and dangerous ; and revaluation of âheritageâ as aesthetic style in local television and video making. Recent, market-driven trends towards a more positive representation of âAfrican heritageâ depart from earlier state initiatives in their explicit focus on visual style and design, raising new questions about the links between heritage and visual aesthetics and asking for an understanding of cultural heritage that takes into account issues of style, design, and commerce
tumor atelectasis gives rise to a solid appearance in pulmonary adenocarcinomas on hr ct
Abstract Introduction Ground glass opacities on HR-CT scan, if malignant on histological examination, correlate with adenocarcinoma in situ. Solid appearance on HR-CT is often considered an invasive component. This study aims to compare radiological features on HR-CT and histological features of primary adenocarcinomas in resection specimens in order to demonstrate the presence of tumor atelectasis in ground glass nodules, part solid and solid nodules. Materials and Methods HR-CT imaging was evaluated, and lung nodules were classified as ground glass nodule, part solid nodule and solid nodule, while adenocarcinomas were classified according to WHO classification. Lepidic growth pattern with collapse was considered if reduction of air in the histological section was present, with maintained pulmonary architecture (without signs of pleural or vascular invasion). Results Radiological and histological features were compared in 47 lesions of 41 patients. The number of ground glass, part solid and solid nodules were 2, 8 and 37, respectively. Lepidic growth pattern with collapse was observed in both ground glass nodules, 7 out of 8 (88%) part solid and 24 out of 37 (65%) solid lesions. Remarkably, more than 50% of adenocarcinomas with solid appearance on HR-CT showed a pre-existing pulmonary architecture with adenocarcinoma with a predominant lepidic growth pattern. In these cases, the solid component can be explained by tumor related collapse in vivo (tumor atelectasis on radiology). Conclusion Tumor atelectasis is a frequent finding in pulmonary adenocarcinomas and results in solid appearance on HR-CT. A solid appearance on HR-CT can not only be attributed to invasion, as has been the assumption until now
Antibiotic resistance and molecular epidemiology of Staphylococcus aureus in Nigeria
<p>Abstract</p> <p>Background</p> <p><it>Staphylococcus aureus </it>is an important pathogen causing a wide range of infections in the hospital and community setting. In order to have adequate information for treatment of <it>S. aureus </it>infections, it is crucial to understand the trends in the antibiotic-resistance patterns. In addition, the occurrence and changes in types of <it>S. aureus</it>, clonal identities, and their geographic spread is essential for the establishment of adequate infection control programmes. In this study, 68 <it>S. aureus </it>isolates obtained from clinical and non-clinical sources in Nigeria between January and April 2009 were characterized using phenotypic and molecular methods.</p> <p>Results</p> <p>All the <it>S. aureus </it>isolates were susceptible to teicoplanin, vancomycin, phosphomycin, fusidic acid, rifampicin, daptomycin, mupirocin, linezolid and tigecycline. Sixteen percent of the isolates were resistant to oxacillin, while 55% and 72% of isolates were resistant to tetracycline and trimethoprim/sulphamethoxazole (cotrimoxazole), respectively (Table <tblr tid="T1">1</tblr>). There was excellent correlation between the broth microdilution assay and detection of antibiotic resistance genes by the multiplex PCR, in the determination of <it>S. aureus </it>resistance to erythromycin, gentamicin, methicillin and tetracycline. A total of 28 <it>spa </it>types were identified in the study, and the predominant <it>spa </it>type among the methicillin-susceptible <it>S. aureus </it>(MSSA) isolates was t084 (13 isolates). The t037-ST241-SCC<it>mec</it>III type was the only clone identified in Maiduguri (North-East Nigeria) while in South-West Nigeria, diversity among the MRSA isolates (t451-ST8-SCC<it>mec</it>V; t008-ST94-SCC<it>mec</it>IV; t002-ST5-SCC<it>mec</it>V; t064-ST8-SCC<it>mec</it>V) was observed. The toxin genes <it>seh </it>and <it>etd </it>were detected in isolates affiliated with clonal complexes CC1, CC80 and sequence type ST25, respectively. The proportion of PVL-positive isolates among MSSA was high (40%). Most of the PVL-positive MSSA isolates were obtained from wound infections and associated with clonal complexes CC1, CC30, CC121 and with sequence type ST152.</p> <tbl id="T1"> <title> <p>Table 1</p> </title> <caption> <p>Antibiotic resistance profile of <it>S. aureu</it><it>s </it>(MSSA and MRSA) from Nigeria</p> </caption> <tblbdy cols="4"> <r> <c> <p/> </c> <c cspan="3" ca="left"> <p><b>Number (%) of resistant isolates among</b>:</p> </c> </r> <r> <c ca="left"> <p><b>Antibiotic</b></p> </c> <c ca="left"> <p><b>MSSA</b></p> <p><b>(n = 57)</b></p> </c> <c ca="left"> <p><b>MRSA</b></p> <p><b>(n = 11)</b></p> </c> <c ca="left"> <p><b>Total</b></p> <p><b>(n = 68)</b></p> </c> </r> <r> <c cspan="4"> <hr/> </c> </r> <r> <c ca="left"> <p>Penicillin</p> </c> <c ca="left"> <p>49 (86)</p> </c> <c ca="left"> <p>11 (100)</p> </c> <c ca="left"> <p>60 (88.2)</p> </c> </r> <r> <c ca="left"> <p>Oxacillin</p> </c> <c ca="left"> <p>0 (0)</p> </c> <c ca="left"> <p>11 (100)</p> </c> <c ca="left"> <p>11 (16.2)</p> </c> </r> <r> <c ca="left"> <p>Teicoplanin</p> </c> <c ca="left"> <p>0 (0)</p> </c> <c ca="left"> <p>0 (0)</p> </c> <c ca="left"> <p>0 (0)</p> </c> </r> <r> <c ca="left"> <p>Vancomycin</p> </c> <c ca="left"> <p>0 (0)</p> </c> <c ca="left"> <p>0 (0)</p> </c> <c ca="left"> <p>0 (0)</p> </c> </r> <r> <c ca="left"> <p>Gentamicin</p> </c> <c ca="left"> <p>1 (1.8)</p> </c> <c ca="left"> <p>9 (81.8)</p> </c> <c ca="left"> <p>10 (14.7)</p> </c> </r> <r> <c ca="left"> <p>Tetracycline</p> </c> <c ca="left"> <p>27 (47.4)</p> </c> <c ca="left"> <p>11 (100)</p> </c> <c ca="left"> <p>38 (55.9)</p> </c> </r> <r> <c ca="left"> <p>Ciprofloxacin</p> </c> <c ca="left"> <p>12 (21.1)</p> </c> <c ca="left"> <p>8 (72.7)</p> </c> <c ca="left"> <p>20 (29.4)</p> </c> </r> <r> <c ca="left"> <p>Moxifloxacin</p> </c> <c ca="left"> <p>0 (0)</p> </c> <c ca="left"> <p>7 (63.6)</p> </c> <c ca="left"> <p>7 (10.3)</p> </c> </r> <r> <c ca="left"> <p>Trimethoprim/sulfamethoxazole</p> </c> <c ca="left"> <p>39 (68.4)</p> </c> <c ca="left"> <p>10 (90.9)</p> </c> <c ca="left"> <p>49 (72.1)</p> </c> </r> <r> <c ca="left"> <p>Phosphomycin</p> </c> <c ca="left"> <p>0 (0)</p> </c> <c ca="left"> <p>0 (0)</p> </c> <c ca="left"> <p>0 (0)</p> </c> </r> <r> <c ca="left"> <p>Fusidic acid</p> </c> <c ca="left"> <p>0 (0)</p> </c> <c ca="left"> <p>0 (0)</p> </c> <c ca="left"> <p>0 (0)</p> </c> </r> <r> <c ca="left"> <p>Erythromycin</p> </c> <c ca="left"> <p>2 (3.5)</p> </c> <c ca="left"> <p>6 (54.5)</p> </c> <c ca="left"> <p>8 (11.8)</p> </c> </r> <r> <c ca="left"> <p>Clindamycin</p> </c> <c ca="left"> <p>0 (0)</p> </c> <c ca="left"> <p>6 (54.5)</p> </c> <c ca="left"> <p>6 (8.8)</p> </c> </r> <r> <c ca="left"> <p>Rifampicin</p> </c> <c ca="left"> <p>0 (0)</p> </c> <c ca="left"> <p>0 (0)</p> </c> <c ca="left"> <p>0 (0)</p> </c> </r> <r> <c ca="left"> <p>Daptomycin</p> </c> <c ca="left"> <p>0 (0)</p> </c> <c ca="left"> <p>0 (0)</p> </c> <c ca="left"> <p>0 (0)</p> </c> </r> <r> <c ca="left"> <p>Mupirocin</p> </c> <c ca="left"> <p>0 (0)</p> </c> <c ca="left"> <p>0 (0)</p> </c> <c ca="left"> <p>0 (0)</p> </c> </r> <r> <c ca="left"> <p>Linezolid</p> </c> <c ca="left"> <p>0 (0)</p> </c> <c ca="left"> <p>0 (0)</p> </c> <c ca="left"> <p>0 (0)</p> </c> </r> <r> <c ca="left"> <p>Tigecycline</p> </c> <c ca="left"> <p>0 (0)</p> </c> <c ca="left"> <p>0 (0)</p> </c> <c ca="left"> <p>0 (0)</p> </c> </r> </tblbdy> </tbl> <p>Conclusions</p> <p>The use of phenotypic and molecular methods provided useful information on antibiotic resistance and molecular diversity of <it>S. aureus </it>in Nigeria. The high proportion of PVL-positive MSSA isolates affiliated to various clonal complexes and detected in all the health institutions is a major concern, both as a source of severe infections and as a potential reservoir that could lead to the emergence of PVL-positive MRSA. This study presents the first baseline information on the nature of the antibiotic resistance genes from <it>S. aureus </it>isolates in Nigeria. There is the need to curtail the spread and establishment of MRSA and PVL-positive MSSA clones in Nigerian health care institutions.</p
Religious revelation, secrecy and the limits of visual representation
This article seeks to contribute to a more adequate understanding of the adoption of modern audiovisual mass media by contemporary religious groups. It does so by examining Pentecostal-charismatic churches as well as the Christian mass culture instigated by its popularity, and so-called traditional religion in Ghana, which develop markedly different attitudes towards audiovisual mass media and assume different positions in the public sphere. Taking into account the complicated entanglement of traditional religion and Pentecostalism, approaching both religions from a perspective of mediation which regards media as intrinsic to religion, and seeking to avoid the pitfall of overestimating the power of modern mass media to determine the world, this article seeks to move beyond an unproductive recurrence to oppositions such as tradition and modernity, or religion and technology. It is argued that instead of taking as a point of departure more or less set ideas about the nexus of vision and modernity, the adoption of new mass media by religious groups needs to be analyzed by a detailed ethnographic investigation of how these new media transform existing practices of religious mediation. Special emphasis is placed on the tension between the possibilities of gaining public presence through new media, and the difficulty in authorizing these media, and the experiences they induce, as authentic. Copyright © 2006 SAGE Publications
Transient laboratory X-ray absorption fine structure spectroscopy on thin films demonstrated with F8BT
We present advanced instrumentation for the investigation of thin organic films offered by a laboratory X-ray absorption fine structure (XAFS) spectrometer for the soft X-ray range. The transmission spectrometer is based on a laser-produced plasma source in combination with a twin-arm reflection zone plate spectrometer. The efficiency and stability of the spectrometer allow for single shot measurements within 500 ps with a resolving power of E/ÎE ~ 900 in a range between 200 eV and 1300 eV. Through the implementation of an optical pump beam, also transient absorption measurements can be performed. The merits of the spectrometer are demonstrated through the investigation of poly[(9,9-dioctylfluorenyl- 2,7-diyl)-alt-co-(1,4-benzo-{2,1â,3}-thiadiazole)] (F8BT), a polyfluorene copolymer. Transient optical pump soft X-ray probe spectroscopy with 500 ps time resolution detects changes in the C K edge spectrum which can be attributed to the lowest unoccupied molecular orbitals of the molecules in the benzothiadiazole unit
Predicting long-term sickness absence among retail workers after four days of sick-listing
Objective This study tested and validated an existing tool for its ability to predict the risk of long-term (ie, â„6 weeks) sickness absence (LTSA) after four days of sick-listing. Methods A 9-item tool is completed online on the fourth day of sick-listing. The tool was tested in a sample (N=13 597) of food retail workers who reported sick between March and May 2017. It was validated in a new sample (N=104 698) of workers (83% retail) who reported sick between January 2020 and April 2021. LTSA risk predictions were calibrated with the Hosmer-Lemeshow (H-L) test; non-significant H-L P-values indicated adequate calibration. Discrimination between workers with and without LTSA was investigated with the area (AUC) under the receiver operating characteristic (ROC) curve. Results The data of 2203 (16%) workers in the test sample and 14 226 (13%) workers in the validation sample was available for analysis. In the test sample, the tool together with age and sex predicted LTSA (H-L test P=0.59) and discriminated between workers with and without LTSA [AUC 0.85, 95% confidence interval (CI) 0.83â0.87]. In the validation sample, LTSA risk predictions were adequate (H-L test P=0.13) and discrimination was excellent (AUC 0.91, 95% CI 0.90â0.92). The ROC curve had an optimal cut-off at a predicted 36% LTSA risk, with sensitivity 0.85 and specificity 0.83. Conclusion The existing 9-item tool can be used to invite sick-listed retail workers with a â„36% LTSA risk for expedited consultations. Further studies are needed to determine LTSA cut-off risks for other economic sectors
Sharing more than friendship - nasal colonization with coagulase-positive staphylococci (CPS) and co-habitation aspects of dogs and their owners
Background Since the relationship between dogs and their owners has changed,
and dogs moved from being working dogs to family members in post-industrial
countries, we hypothesized that zoonotic transmission of opportunistic
pathogens like coagulase positive staphylococci (CPS) is likely between dogs
and their owners. Methodology/Principal Findings CPS- nasal carriage,
different aspects of human-to-dog relationship as well as potential
interspecies transmission risk factors were investigated by offering nasal
swabs and a questionnaire to dog owners (108) and their dogs (108) at a dog
show in 2009. S. aureus was found in swabs of 20 (18.5%) humans and two dogs
(1.8%), and spa types which correspond to well known human S. aureus lineages
dominated (e.g. CC45, CC30 and CC22). Multilocus sequence typing (MLST) of the
two canine strains revealed ST72 and ST2065 (single locus variant of ST34).
Fifteen dogs (13.9%) and six owners (5.6%) harboured S. pseudintermedius,
including one mecA-positive human isolate (MRSP). Pulsed field gel
electrophoresis (PFGE) revealed that one dog/owner pair harboured
indistinguishable S. pseudintermedius- isolates of ST33. Ten (48%) of the 21
S. pseudintermedius-isolates showed resistance towards more than one
antimicrobial class. 88.9% of the dog owners reported to allow at least one
dog into the house, 68.5% allow the dog(s) to rest on the sofa, 39.8% allow
their dogs to come onto the bed, 93.5% let them lick their hands and 52.8% let
them lick their face. Bivariate analysis of putative risk factors revealed
that dog owners who keep more than two dogs have a significantly higher chance
of being colonized with S. pseudintermedius than those who keep 1â2 dogs
(p<0.05). Conclusions/Recommendations In conclusion, CPS transmission between
dog owners and their dogs is possible. Further investigation regarding
interspecies transmission and the diverse adaptive pathways influencing the
epidemiology of CPS (including MRSA and MRSP) in different hosts is needed
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