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Currently no national guidelines exist for the management of scabies outbreaks in residential or nursing care homes for the elderly in the United Kingdom. In this setting, diagnosis and treatment of scabies outbreaks is often delayed and optimal drug treatment, environmental control measures and even outcome measures are unclear. We undertook a systematic review to establish the efficacy of outbreak management interventions and determine evidence-based recommendations. Four electronic databases were searched for relevant studies, which were assessed using a quality assessment tool drawing on STROBE guidelines to describe the quality of observational data. Nineteen outbreak reports were identified, describing both drug treatment and environmental management measures. The quality of data was poor; none reported all outcome measures and only four described symptom relief measures. We were unable to make definitive evidence-based recommendations. We draw on the results to propose a framework for data collection in future observational studies of scabies outbreaks. While high-quality randomised controlled trials are needed to determine optimal drug treatment, evidence on environmental measures will need augmentation through other literature studies. The quality assessment tool designed is a useful resource for reporting of outcome measures including patient-reported measures in future outbreaks.
This study examined the effectiveness of a formal postdoctoral education program designed to teach skills in clinical and translational science, using scholar publication rates as a measure of research productivity.
Participants included 70 clinical fellows who were admitted to a master’s or certificate training program in clinical and translational science from 1999 to 2015 and 70 matched control peers. The primary outcomes were the number of publications 5 years post-fellowship matriculation and time to publishing 15 peer-reviewed manuscripts post-matriculation.
Clinical and translational science program graduates published significantly more peer-reviewed manuscripts at 5 years post-matriculation (median 8 vs 5, p=0.041) and had a faster time to publication of 15 peer-reviewed manuscripts (matched hazard ratio = 2.91, p=0.002). Additionally, program graduates’ publications yielded a significantly higher average H-index (11 vs. 7, p=0.013).
These findings support the effectiveness of formal training programs in clinical and translational science by increasing academic productivity.
The basis of this paper is the elementary observation that the n-step descendant distribution of any Galton–Watson process satisfies a discrete Smoluchowski coagulation equation with multiple coalescence. Using this we obtain simple necessary and sufficient criteria for the convergence of scaling limits of critical Galton–Watson processes in terms of scaled family-size distributions and a natural notion of convergence of Lévy triples. Our results provide a clear and natural interpretation, and an alternate proof, of the fact that the Lévy jump measure of certain continuous-state branching processes (CSBPs) satisfies a generalized Smoluchowski equation. (This result was previously proved by Bertoin and Le Gall (2006).) Our analysis shows that the nonlinear scaling dynamics of CSBPs become linear and purely dilatational when expressed in terms of the Lévy triple associated with the branching mechanism. We prove a continuity theorem for CSBPs in terms of the associated Lévy triples, and use our scaling analysis to prove the existence of universal critical Galton–Watson processes and CSBPs analogous to Doeblin's `universal laws'. Namely, these universal processes generate all possible critical and subcritical CSBPs as subsequential scaling limits. Our convergence results rely on a natural topology for Lévy triples and a continuity theorem for Bernstein transforms (Laplace exponents) which we develop in a self-contained appendix.
Commonly thought of as a disease of poverty and overcrowding in resource-poor settings globally, scabies is also an important public health issue in residential care facilities for the elderly (RCFE) in high-income countries such as the UK. We compared and contrasted current local Health Protection Team (HPT) guidelines for the management of scabies outbreaks in RCFE throughout England. We performed content analysis on 20 guidelines, and used this to create a quantitative report of their variation in key dimensions. Although the guidelines were generally consistent on issues such as the treatment protocols for individual patients, there was substantial variation in their recommendations regarding the prophylactic treatment of contacts, infection control measures and the roles and responsibilities of individual stakeholders. Most guidelines did not adequately address the logistical challenges associated with mass treatment in this setting. We conclude that the heterogeneous nature of the guidelines reviewed is an argument in favour of national guidelines being produced.
The first aim was to use confirmatory factor analysis (CFA) to test a hypothesis that two factors (internalizing and externalizing) account for lifetime co-morbid DSM-IV diagnoses among adults with bipolar I (BPI) disorder. The second aim was to use confirmatory latent class analysis (CLCA) to test the hypothesis that four clinical subtypes are detectible: pure BPI; BPI plus internalizing disorders only; BPI plus externalizing disorders only; and BPI plus internalizing and externalizing disorders.
A cohort of 699 multiplex BPI families was studied, ascertained and assessed (1998–2003) by the National Institute of Mental Health Genetics Initiative Bipolar Consortium: 1156 with BPI disorder (504 adult probands; 594 first-degree relatives; and 58 more distant relatives) and 563 first-degree relatives without BPI. Best-estimate consensus DSM-IV diagnoses were based on structured interviews, family history and medical records. MPLUS software was used for CFA and CLCA.
The two-factor CFA model fit the data very well, and could not be improved by adding or removing paths. The four-class CLCA model fit better than exploratory LCA models or post-hoc-modified CLCA models. The two factors and four classes were associated with distinctive clinical course and severity variables, adjusted for proband gender. Co-morbidity, especially more than one internalizing and/or externalizing disorder, was associated with a more severe and complicated course of illness. The four classes demonstrated significant familial aggregation, adjusted for gender and age of relatives.
The BPI two-factor and four-cluster hypotheses demonstrated substantial confirmatory support. These models may be useful for subtyping BPI disorders, predicting course of illness and refining the phenotype in genetic studies.
Cognitive deficits in schizophrenia are well established and are known to be present during the first episode of a psychotic disorder. In addition, consistent heterogeneity within these impairments remains unexplained. One potential source of variability may be the level of pre-morbid adjustment prior to the onset of first-episode psychosis (FEP).
Ninety-four FEP patients and 32 healthy controls were assessed at baseline on several neuropsychological tests comprising six cognitive domains (verbal memory, visual memory, working memory, processing speed, reasoning/problem-solving and attention) and an abbreviated version of the full IQ. A global neurocognitive domain was also computed. Pre-morbid adjustment patterns were divided into three distinct groups: stable-poor, stable-good and deteriorating course.
Based on a cut-off of 0.8 for effect size, the stable-poor pre-morbid adjustment group was significantly more impaired on most cognitive domains and full IQ compared to the deteriorating group, who were more severely impaired on all measures compared to the stable-good group. The type of cognitive deficit within each subgroup did not differ and the results indicate that a global neurocognition measure may reliably reflect the severity of cognitive impairment within each subgroup.
Pre-morbid adjustment patterns prior to onset of psychosis are associated with severity but not type of cognitive impairment. Patients in the stable-poor group are generally more impaired compared to the deteriorating group, who are, in turn, more impaired than the stable-good group.
Measuring elastic properties of cells has gained importance in the study of malignant transformations. The stiffness of a cell, which is technically referred to as the modulus of elasticity or Young's Modulus, E, is the measure of the amount of cell deformation caused by an applied known force. In vitro studies have shown that cancer cells have much lower elastic stiffness than normal cells. These stiffness measurements and their differences can be used to study the behavioral mechanics of how cancer cells grow, profligate, and die in a patient. Another important use of this difference in elasticity is in cancer detection.
In this study, we explore the viability of measuring the elastic modulus of cancer cells by using a method that only requires the use of a low magnification microscope and a digital camera. In particular we are interested in applying the previously reported relationship between the wrinkling of thin films and the elastic properties of freely floating polystyrene (PS) films. Our work extends the scope of previous thin film studies by evaluating wrinkle formation in floating polystyrene films coated with biological cells. Our results show that the wrinkle formation is modified, both in morphology and in size, by the presence of a cellular monolayer on top of the PS film.
Few studies have examined the underlying factor structure of signs and symptoms occurring before the first psychotic episode. Our objective was to determine whether factors derived from early signs and symptoms are differentially associated with non-affective versus affective psychosis.
A principal components factor analysis was performed on early signs and symptoms reported by 128 individuals with first-episode psychosis. Factor scores were examined for their associations with duration of untreated illness, drug abuse prior to onset of psychosis, and diagnosis (schizophrenia versus affective psychosis).
Of the 27 early signs and symptoms reported by patients, depression and anxiety were the most frequent. Five factors were identified based on these early signs and symptoms: depression, disorganization/mania, positive symptoms, negative symptoms and social withdrawal. Longer duration of untreated illness was associated with higher levels of depression and social withdrawal. Individuals with a history of drug abuse prior to the onset of psychosis scored higher on pre-psychotic depression and negative symptoms. The two mood-related factors, depression and disorganization/mania, distinguished the eventual first-episode diagnosis of affective psychosis from schizophrenia. Individuals with affective psychosis were also more likely to have a ‘mood-related’ sign and symptom as their first psychiatric change than individuals later diagnosed with schizophrenia.
Factors derived from early signs and symptoms reported by a full diagnostic spectrum sample of psychosis can have implications for future diagnostic trajectories. The findings are a step forward in the process of understanding and characterizing clinically important phenomena to be observed prior to the onset of psychosis.
This work investigates the mechanical properties of ITO on PEN substrates as a function of processing conditions, including rf power, substrate temperature, and substrate treatment. The best mechanical performance is obtained from high substrate temperature and low rf power. Plasma treatment gases also influence mechanical properties, with mixture of nitrogen and hydrogen gases producing the best results. This work provides an initial understanding of the impact of sputter process conditions on film's mechanical performance.
Semiconducting oxides are widely known and commercially applied for their gas sensing properties. However, biochemical sensing has mostly depended on optical and electrochemical techniques that are more cumbersome. This work investigates the biosensing characteristics of ZnO nanobelts and ZnO thin films. Zinc oxide thin film sensors showed changes in conductivity after protein functionalization with rabbit IgG and hybridization with anti-rabbit IgG. Conductivity changes were also measured after coating the oxides with MCF-7 cancer cells and its antibodies. In another set of experiments, ZnO nanobelts showed systematic conductivity changes with rabbit IgG protein hybridization. The experimental results in this paper indicate that the conductimetric properties of nano and thin film oxides can be sensitized to protein and cancer cell hybridization reactions. This technique can also be applied to certain other pathogen proteins or toxic proteins from the environment leading to low-cost miniaturized wireless biosensors.
Eighty-four strains of Vibrio cholerae O1, O139 and non-O1/non-O139 from clinical and
environmental sources were investigated for the presence of the toxin co-regulated pilus gene,
tcpA, the virulence cassette genes ctxA, zot, ace and
cep and also for their ability to elaborate
haemolysin and protease. The ctxA and zot genes were detected using DNA–DNA
hybridization while the ace, cep and tcpA genes were detected using PCR. Production of
haemolysin and protease was detected using mammalian erythrocytes and an agar diffusion
assay respectively. Analysis of their virulence profiles showed six different groups designated
Type I to Type VI and the major distinguishing factor among these profiles was in the in vitro
production of haemolysin and/or protease. Clinical O1, O139 and environmental O1 strains
were similar with regard to presence of the virulence cassette genes. All environmental O1
strains with the exception of one were found to possess ctxA, zot and ace giving rise to the
probability that these strains may actually be of clinical origin. One strain which had only cep
but none of the toxin genes may be a true environmental isolate. The virulence cassette and
colonization factor genes were absent in all non-O1/non-O139 environmental strains but
production of both the haemolysin and protease was present, indicating that these may be
putative virulence factors. These findings suggest that with regard to its pathogenic potential,
only strains of the O1 and O139 serogroup that possess the tcpA gene which encodes the phage
receptor, have the potential to acquire the CTX genetic element and become choleragenic.
Forty-three clinical strains of V. cholerae O1 biotype El Tor were isolated between 3 May and
10 June 1998 during an outbreak in the metropolitan area of Kuala Lumpur and its suburbs.
With the exception of three Inaba strains that were restricted to three members of a family, all
the others belonged to the Ogawa serotype. The strains were analysed for clonality using
ribotyping and pulsed-field gel electrophoresis (PFGE). Two ribotypes, V/B21a and B27, were
identified among 40 Ogawa isolates using BglI restriction endonuclease. Ribotype V/B21a has
been described previously from Taiwan and Colombia and several Asian countries while B27
has been reported among isolates from Senegal. The three Inaba strains belonged to one
ribotype, designated type A, not previously reported. PFGE analysis using NotI revealed that
all isolates within a ribotype had identical profiles demonstrating clonality amongst the strains.
Dice coefficient analysis of the two Ogawa genotypes revealed 89% similarity on ribotype
patterns and 91.3% on PFGE profiles. Ribotype V/B21a isolates were associated with cases
from dispersed areas of Kuala Lumpur and its suburbs while ribotype B27 was restricted to
cases from one particular area suggesting a common-source outbreak.
An engineered system for dry storage of aluminum-clad foreign and domestic research reactor spent fuel owned by the United States Department of Energy is being considered to store the fuel up to a nominal period of 40 years prior to ultimate disposition. Scientifically-based criteria for environmental limits to drying and storing the fuels for this system are being developed to avoid excessive degradation in sealed and non-sealed (open to air) dry storage systems. These limits are based on consideration of degradation modes that can cause loss of net section of the cladding, embrittlement of the cladding, distortion of the fuel, or release of fuel and fission products from the fuel/clad system. Potential degradation mechanisms include corrosion mechanisms from exposure to air and/or sources of humidity, hydrogen blistering of the aluminum cladding, distortion of the fuel due to creep, and interdiffusion of the fuel and fission products with the cladding.
The aluminum-clad research reactor fuels are predominantly highly-enriched aluminumuranium alloy fuel which is clad with aluminum alloys similar to 1100, 5052, and 6061 aluminum. In the absence of corrodant species, degradation due to creep and diffusion mechanisms limit the maximum fuel storage temperature to 200°C. The results of laboratoryscale corrosion tests indicate that this fuel could be stored under air up to 200°C at low relative humidity levels (< 20%) to limit corrosion of the cladding and fuel (exposed to the storage environment through assumed pre-existing pits in the cladding). Excessive degradation of fuels with uranium metal up to 200°C can be avoided if the fuel is sufficiently dried and contained in a sealed system; open storage can be achieved if the temperature is controlled to avoid excessive corrosion even in dry air.
Aluminum clad fuel and target elements represent approximately 10% of the DOE owned spent nuclear fuels. The uranium in a large fraction of these fuels is highly enriched and is present as uraniumaluminides which are distributed relatively uniformly within an Al-U alloy core. Emerging acceptance criteria are expected to limit the dry storage temperature for aluminum based fuels to approximately 200°C. The rock temperature near the center of a repository may exceed 200°C if the thermal loading approaches 110 kW/acre. This combination may force the placement of canisters containing aluminum based fuels near the repository periphery. The warm, moist environment anticipated at the periphery may provide aggressive conditions for corrosion of the canister and the highly enriched, aluminum based fuels. Peripheral locations may also be the most vulnerable to covert fuel removal operations. Possible consequences of mixing aluminum based fuels with other fuels in a repository are discussed in this paper.
We have investigated the low temperature (4.5 K) photoluminescence (PL) spectra of GaSb and GaInAsSb layers. The layers were grown by liquid phase electro-epitaxial (LPEE) technique. Several bound excitomc transitions were observed both in GaSb and GaInAsSb layers. Shift in the PL peak energy corresponding to the band to band transition with temperature was determined. The linear part of the shift above 100K, exhibited a slope of -0.3 meV/K.
Follow-up cardiac catheterization and angiography was performed in 23 patients after complete, staged repair of pulmonary atresia with ventricular septal defect and multiple systemic-to-pulmonary collateral arteries. Time interval from repair varied from 0.2 to 89 months (mean 26 months). Major residual anomalies of arborization of the pulmonary arteries, with or without pulmonary vascular disease, were present in six patients, two of whom had die patch on the ventricular septal defect perforated because of systemic or suprasystemic right ventricular pressure in the early postoperative period after repair. Both of these children later died, while the other four patients were found to have moderately to severely elevated ventricular pressure ratios and pulmonary arterial pressure measurements, though they are all alive at follow-up intervals from 20 months to 6.8 years. The remaining 17 patients all had hemodynamically satisfactory or good results, with pulmonary arterial mean pressures ranging from 8 to 30 mm Hg (mean 22 mm Hg) and pressure ratios between the ventricles from 0.24 to 0.75 (mean 0.43)—the higher ratios generally reflecting gradients across the conduit valve. Angiography demonstrated that the hypoplastic pulmonary arteries increased in size to normal dimensions, during staging, in most patients, though abnormalities of arborization persisted in several. Analysis of the data from the entire cohort of 58 patients, who were accepted for staging towards repair, showed a significant association between early age at entry to the program and likelihood of complete repair being achievable.
SiGe alloys have been successfully applied to a number of semiconductor devices, including bipolar heterojunction transistors, field effect transistors (FET's), and optoelectronic devices and structures. This review paper will first summarize the results obtained to-date in bipolar transistors, highlighting the design flexibility and the trade-offs offered by SiGe heterojunction technology and bandgap engineering, like junction field/capacitance control, liquid nitrogen operation and complementary processes. The leverage of this technology in high speed circuits will be discussed, including the record 75 GHz fr and 60 GHz fmax heterojunction bipolar transistors, the achievement of sub-25 ps ECL ring oscillator delay, and the doubling of the mobility in p-MODFETs. The applications of this technology to optoelectronic devices, including detectors and waveguides, will also be reviewed, to extend the use of silicon technology to long wavelength communication technology and infrared imaging.
We report the growth and characterization of GexSi1−x films for optical waveguiding. GexSi1−x/Si waveguides were grown by rapid thermal processing chemical vapor deposition. An average attenuation of 3.3 dB/cm was achieved for a 1 μm thick Ge0.04Si0.96 layer patterned into rib waveguides 2000 Å deep with widths of 5 μm. Directional couplers were also fabricated. Average coupling efficiencies of 85% were achieved for 1.5 μm interwaveguide separation.