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The Continuous Performance Test (CPT) has become an essential constituent of the neuropsychological investigation of schizophrenia. Also, a vast number of brain imaging studies, mostly PET investigations, have employed the CPT as a cognitive challenge and established a relative hypofrontality in schizophrenics compared to controls. The aim of the present investigation was to clarify whether this predescribed hypofrontality could also be verified using functional magnetic resonance imaging (fMRI). 20 healthy volunteers and 14 schizophrenics on stable neuroleptic medication were included. Imaging was performed using the CPT-double-T-version and a clinical 1.5 T MRI-scanner with a single slice technique and a T2*-weighted gradient-echo-sequence. The schizophrenics exhibited a decreased activation in the right mesial prefrontal cortex, the right cingulate and the left thalamus compared to controls. These results obtained by fMRI are discussed in relation to published findings using PET.
The elimination of unwanted catch in mixed species fisheries is technically challenging given the complexity of fish behaviour within nets. Most approaches to date have employed technologies that modify the nets themselves or use physical sorting grids within the gear. There is currently increasing interest in the use of artificial light to either deter fish from entering the net, or to enhance their escapement from within the net. Here, we evaluated the differences in catch retained in a standard otter trawl, relative to the same gear fitted with a square mesh panel, or a square mesh panel fitted with LEDs. We found that the selectivity of the gear differed depending on water depth. When using a square mesh panel in shallow depths of 29–40 m the unwanted bycatch of whiting and haddock was reduced by 86% and 58% respectively. In deep, darker water (45–95 m), no change in catch was observed in the square-mesh panel treatment, however when LEDs were added to the square-mesh panel, haddock and flatfish catches were reduced by 47% and 25% respectively. These findings demonstrate the potential to improve the performance of bycatch reduction devices through the addition of light devices to enhance selectivity. The results also highlight species-specific and site-specific differences in the performance of bycatch reduction devices, and hence a more adaptive approach to reduce bycatch is probably required to maximize performance.
The Boko Haram insurgency has brought turmoil and instability to Nigeria, generating a large number of internally displaced people and adding to the country's 17.5 million orphans and vulnerable children. Recently, steps have been taken to improve the mental healthcare infrastructure in Nigeria, including revamping national policies and initiating training of primary care providers in mental healthcare. In order for these efforts to succeed, they require means for community-based detection and linkage to care. A major gap preventing such efforts is the shortage of culturally appropriate, valid screening tools for identifying emotional and behavioral disorders among adolescents. In particular, studies have not conducted simultaneous validation of screening tools in multiple languages, to support screening and detection efforts in linguistically diverse populations. We aim to culturally adapt screening tools for emotional and behavioral disorders for use among adolescents in Nigeria, in order to facilitate future validation studies.
We used a rigorous mixed-method process to culturally adapt the Depression Self Rating Scale, Child PTSD Symptom Scale, and Disruptive Behavior Disorders Rating Scale. We employed expert translations, focus group discussions (N = 24), and piloting with cognitive interviewing (N = 24) to achieve semantic, content, technical, and criterion equivalence of screening tool items.
We identified and adapted items that were conceptually difficult for adolescents to understand, conceptually non-equivalent across languages, considered unacceptable to discuss, or stigmatizing. Findings regarding problematic items largely align with existing literature regarding cross-cultural adaptation.
Culturally adapting screening tools represents a vital first step toward improving community case detection.
High-redshift quasars are unique probes of the evolution of supermassive black holes and the intergalactic medium at the end of the epoch of reionization. We present the optical spectra of eight new z ~ 6 quasars selected from the Panoramic Survey Telescope & Rapid Response System 1 (Pan-STARRS1). Details of the selection strategy can be found in Bañados et al. (2014). With this work we increase the number of known quasars at z < 5.7 by more than 10%. The quasars discovered here span a large range of luminosities (19.6 ≤ zP1 ≤ 21.2) and are remarkably heterogeneous in their spectral features: half of them show bright emission lines whereas the other half show weak or no Lyα emission line. We find a larger fraction of weak–line emission quasars than in lower redshift studies, although still based on low number statistics, this may imply that the quasar population could be more diverse than previously thought.
The objectives of this study were to determine the incidence density and the occurrence of horizontal spread of highly resistant gram-negative rods (HR-GNRs) in Dutch hospitals. The factors that influence these outcome measures were also investigated.
All patients with HR-GNRs, as determined by sample testing, who were hospitalized in 1 of 18 hospitals during a 6-month period (April through October 2007) were included in this study. For all available isolates, the species was identified, susceptibility was determined (including the presence of extended-spectrum β-lactamases [ESBLs]), and molecular typing was performed. On the basis of a combination of species identification, molecular typing, and epidemiological data, the occurrence of nosocomial transmission was determined.
The mean incidence density of patients with HR-GNRs was 55 per 100,000 patient-days (cumulative incidence, 39 per 10,000 patients admitted). A facility being a university hospital was a statistically significant (P = .03) independent determinant of a higher incidence of patients with HR-GNRs. The majority of HR-GNR isolates were ESBL producers. The adjusted transmission index—the ratio between secondary and primary cases—in the participating hospitals ranged from 0.0 to 0.2. The overall adjusted transmission index of HR-GNRs was 0.07. No determinants for a higher transmission index were identified.
The nosocomial transmission rate of HR-GNRs was relatively low in all hospitals where well-established transmission-based precautions were used. The incidence density of patients with HR-GNRs was higher in university hospitals, probably due to the patient population and the complexity of the care provided.
Locations of gamma dose rate sensors have often been chosen by administrative or geometrical criteria. Nowadays computational capacity allows for a more realistic basis. We use simulations of potential radioactive plumes based on weather data of one year to investigate the threats to regions without own nuclear power plants and to find good numbers and locations of sensors to detect such plumes. We optimise sensor locations by minimising a cost function that can take into account numbers of undetected plumes, their dose to the region in general, or on the population. Besides we assess the effect of administrative constraints, be it that sensors have to cover administrative units, or that optimisation is done for sub-regions separately. Finally we evaluate the robustness of the approach if less or other plumes are used. The main findings are that sensors at boundaries are often best, but also typical paths of plumes may be important, and that administrative constraints may necessitate much more sensors. The small numbers of sensors actually deployed in these regions seem sufficient. However, the latter may be an artefact of the low number of plumes we considered. Altogether, combined with other considerations, this approach can contribute to better decisions about gamma dose rate sensor locations.
To evaluate the actual burden of methicillin-resistant Staphylococcus aureus and determine risk factors for carriage and infection, we performed a prevalence survey with a nested case-control study among inpatients in Dutch hospitals. The prevalence of carriage was 0.94 cases per 1,000 inpatients, and the prevalence of infection was 0.21 cases per 1,000 inPatients. Professional contact with livestock and a stay in a foreign hospital were associated with carriage.
The Hollomon-Jaffe parameter is commonly used to characterize thermal cycles and define
time-temperature equivalences during tempering, but it can only be computed for simple
thermal cycles defined by a couple of values [temperature; time]. Its use is not adapted
for complex thermal cycles. Three tempering parameters which integrate the full thermal
cycles were investigated: the Hollomon-Jaffe derivative parameter, and the Tsuchiyama and
Arrhenius laws. Simple and complex thermal cycles were performed on a water-quenched
carbon steel (i.e. different heating and cooling rates or two-step cycles, with
temperature varying between 450 °C and 750 °C and times from 30 s to 3 days). All three
tempering parameters show good correlation with the tensile properties of the material,
even when complex cycles were performed, provided that the material constant is optimized.
The sensitivity to the determination of this constant is low for the Tsuchiyama and
Arrhenius laws: they can be considered as robust and reliable. On the contrary, the
Hollomon-Jaffe derivative parameter proved unstable.
The IntCal04 and Marine04 radiocarbon calibration curves have been updated from 12 cal kBP (cal kBP is here defined as thousands of calibrated years before AD 1950), and extended to 50 cal kBP, utilizing newly available data sets that meet the IntCal Working Group criteria for pristine corals and other carbonates and for quantification of uncertainty in both the 14C and calendar timescales as established in 2002. No change was made to the curves from 0–12 cal kBP. The curves were constructed using a Markov chain Monte Carlo (MCMC) implementation of the random walk model used for IntCal04 and Marine04. The new curves were ratified at the 20th International Radiocarbon Conference in June 2009 and are available in the Supplemental Material at www.radiocarbon.org.
The European Model for Inhabited Areas (ERMIN) was developed to allow a user to explore different recovery options following the contamination of an urban environment with radioactive material and to refine an appropriate strategy for the whole region affected. The input data include a description of the environment, initial deposition of radionuclides on to a reference surface and a description of countermeasures. Output information includes the average doses to members of the public from external exposure to gamma and beta radiation from deposited radionuclides and inhalation of resuspended radioactivity, the contamination on urban surfaces, the activity concentration in air from resuspension, the doses to workers undertaking the recovery work, the quantity and activity of waste generated and the cost and work required to implement the countermeasure. ERMIN has been designed to be implemented as a tool that supports the approach of decision-makers and allows the area to be broken down into smaller regions where different conditions prevail and different countermeasure packages are enacted.
La prueba de ejecución continua (CPT) se ha convertido en un componente esencial de la investigación neuropsicológica de la esquizofrenia. Además, un número considerable de estudios de imágenes cerebrales, en la mayor parte investigaciones de PET, ha empleado la CPT como estímulo cognitivo y ha establecido una hipofrontalidad relativa en los esquizofrénicos en comparación con los controles. El propósito de la presente investigación era clarificar si esta hipofrontalidad descrita antes se podía verificar también utilizando imágenes de resonancia magnética funcionales (fMRI). Se incluyó a 20 voluntarios sanos y 14 esquizofrénicos con medicación neuroléptica estable. La toma de imágenes se realizó utilizando la CPT, versión T doble, y un escáner clínico de MRI de 1,5 T con una técnica de rodaja única y una secuencia de gradiente de eco potenciado en T¡*. Los esquizofrénicos mostraron una activación disminuida en el córtex prefrontal medial derecho, el cingulado derecho y el tálamo izquierdo en comparación con los controles. Estos resultados obtenidos por fMRI se analizan con relación a los resultados publicados utilizando PET.
The relationship between the defect microstructure of SiC films grown by solid-source molecular-beam epitaxy on 4H and 6H–SiC substrates and their growth conditions, for substrate temperatures ranging between 950 and 1300 °C, has been investigated by a combination of transmission electron microscopy and atomic force microscopy. The results demonstrate that the formation of defective cubic films is generally found to occur at temperatures below 1000 °C. At temperatures above 1000 °C our investigations prove that simultaneous supply of C and Si in the step-flow growth mode on vicinal 4H and 6H substrate surfaces results in defect-free hexagonal SiC layers, and defect-free cubic SiC can be grown by the alternating deposition technique. The controlled overgrowth of hexagonal on top of cubic layers is demonstrated for thin layer thicknesses.
The effects of substrate cleaning, nitridation time, and substrate temperature in the range 800–1000 °C on the microstructure of AlN/Si(111) films grown by simultaneous plasma-assisted molecular beam epitaxy have been investigated. It has been demonstrated, using a combination of conventional and high-resolution transmission electron microscopy, that the interface structure, the film defect structure, and the film surface roughness are strongly related. The formation of single crystal 2H–AlN films with atomically flat surfaces occurs at 800 °C for conditions of 2.5 nm/min growth rate on very pure, atomically flat Si substrates.
We present HSTSpace Telescope Imaging Spectrograph (STIS) slitless spectroscopy of the NGC4151 narrow line region (NLR) as a probe of the kinematic stucture of the extended emission-line gas emanating from the nucleus. Using slitless spectroscopy at two roll angles (with a spatial resolution of 0.051 ″/pixel and a point source spectral resolution of 0.55 Å) augmented with narrow band images, we have mapped the velocity field of the NLR as defined by ˜60 discrete cloud structures in [OIII]. Flux measurements of [OII], Hβ, [OIII], [OI], and [SII] were made for individual cloud structures wherever possible.
The ALFA mission is designed to map the entire sky at frequencies between approximately 0.3 and 30 MHz with angular resolution limited by interstellar and interplanetary scattering. Most of this region of the spectrum is inaccessible from the ground because of absorption and refraction by the Earth’s ionosphere. A wide range of astrophysical questions concerning solar system, galactic, and extragalactic objects could be answered with high resolution images at low frequencies, where absorption effects and coherent emission processes become important and the synchrotron lifetimes of electrons are comparable to the age of the universe.
The superconducting filaments in (Bi, Pb)2Sr2Ca2Cu3Ox/Ag composite tapes have been imaged directly through the outer silver sheath of an unpolished tape by means of a magneto-optical imaging technique. The images reveal the morphology and alignment of the uppermost layer of filaments located as much as 112 μm below the unpolished tape surface, the depths of these filaments, and the homogeneity of the magnetic flux distribution within these filaments. These results demonstrate that the magneto-optical technique is a valuable nondestructive tool for analyzing (Bi, Pb)2Sr2Ca2Cu3Ox composite tapes.
A retrospective study to assess the clinical usefulness of non-surgical management of epistaxis was performed on 340 patients requiring hospitalisation at the ENT Department of La Paz Hospital (Madrid). The previous history, type of management, hospitalisation time, and volume of transfusion were considered. Nasal packing was employed in 94.1 per cent of the patients. Most patients (82.9 per cent) were hospitalised less than seven days, and 84.1 per cent of the patients required no transfusion. There was one death.
This study supports the clinical usefulness of conservative management in the treatment of patients with epistaxis.
At the lowest radio frequencies (≤30 MHz), the Earth's ionosphere transmits poorly or not at all. This relatively unexplored region of the electromagnetic spectrum is thus an area where high resolution, high sensitivity observations can open a new window for astronomical investigations. Also, extending observations down to very low frequencies brings astronomy to a fundamental physical limit where the Milky Way becomes optically thick over relatively short path lengths due to diffuse free-free absorption.