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In low- and middle-income countries, mental health training often includes sending few generalist clinicians to specialist-led programs for several weeks. Our objective is to develop and test a video-assisted training model addressing the shortcomings of traditional programs that affect scalability: failing to train all clinicians, disrupting clinical services, and depending on specialists.
We implemented the program -video lectures and on-site skills training- for all clinicians at a rural Nepali hospital. We used Wilcoxon signed-rank tests to evaluate pre- and post-test change in knowledge (diagnostic criteria, differential diagnosis, and appropriate treatment). We used a series of ‘Yes’ or ‘No’ questions to assess attitudes about mental illness, and utilized exact McNemar's test to analyze the proportions of participants who held a specific belief before and after the training. We assessed acceptability and feasibility through key informant interviews and structured feedback.
For each topic except depression, there was a statistically significant increase (Δ) in median scores on knowledge questionnaires: Acute Stress Reaction (Δ = 20, p = 0.03), Depression (Δ = 11, p = 0.12), Grief (Δ = 40, p < 0.01), Psychosis (Δ = 22, p = 0.01), and post-traumatic stress disorder (Δ = 20, p = 0.01). The training received high ratings; key informants shared examples and views about the training's positive impact and complementary nature of the program's components.
Video lectures and on-site skills training can address the limitations of a conventional training model while being acceptable, feasible, and impactful toward improving knowledge and attitudes of the participants.
There is consensus about the importance of ‘recovery’ in mental health services, but the link between recovery orientation of mental health teams and personal recovery of individuals has been underresearched.
To investigate differences in team leader, clinician and service user perspectives of recovery orientation of community adult mental health teams in England.
In six English mental health National Health Service (NHS) trusts, randomly chosen community adult mental health teams were surveyed. A random sample of ten patients, one team leader and a convenience sample of five clinicians were surveyed from each team. All respondents rated the recovery orientation of their team using parallel versions of the Recovery Self Assessment (RSA). In addition, service users also rated their own personal recovery using the Questionnaire about Processes of Recovery (QPR).
Team leaders (n = 22) rated recovery orientation higher than clinicians (n = 109) or patients (n = 120) (Wald(2) = 7.0, P = 0.03), and both NHS trust and team type influenced RSA ratings. Patient-rated recovery orientation was a predictor of personal recovery (b = 0.58, 95% CI 0.31–0.85, P<0.001). Team leaders and clinicians with experience of mental illness (39%) or supporting a family member or friend with mental illness (76%) did not differ in their RSA ratings from other team leaders or clinicians.
Compared with team leaders, frontline clinicians and service users have less positive views on recovery orientation. Increasing recovery orientation may support personal recovery.
Exposure to environmental chemicals has adverse effects on the health and survival of humans. Emerging evidence supports the idea that exposure to endocrine-disrupting compounds (EDCs) can perturb an individual’s physiological set point and as a result increase his/her propensity toward several diseases. The purpose of this review is to provide an update on di-(2-ethylhexyl) phthalate, the primary plasticizer found in plastic medical devices used in neonatal intensive care units, its effects on the fetus and newborn, epidemiological studies, pharmacokinetics, toxicity and epigenetic implications. We searched the PubMed databases to identify relevant studies. Phthalates are known EDCs that primarily are used to improve the flexibility of polyvinyl chloride plastic products and are called plasticizers in lay terms. Neonates and infants are particularly vulnerable to the effects of phthalates, beginning with maternal exposure and placental transfer during gestation and during infancy following birth. In line with the developmental origins of adult disease, a focus on the effects of environmental chemicals in utero or early childhood on the genesis of adult diseases through epigenome modulation is timely and important. The epigenetic effects of phthalates have not been fully elucidated, but accumulating evidence suggests that they may be associated with adverse health effects, some of which may be heritable. Phthalate exposure during pregnancy and the perinatal period is particularly worrisome in health-care settings. Although the clinical significance of phthalate exposure has been difficult to assess with epidemiologic studies, the evidence that physiological changes occur due to exposure to phthalates is growing and points toward the need for more investigation at a molecular, specifically epigenetic level.
We examine the extent to which adult helminths of freshwater fishes have been part of
the Great American Biotic Interchange (GABI), by integrating information in published
studies and new data from Panama with fish biogeography and Earth history of Middle
America. The review illustrates the following: (1) the helminth fauna south of the
Trans-Mexican Volcanic Belt, and especially south of the Isthmus of Tehuantepec,
shows strong Neotropical affinities; (2) host–parasite associations follow principles
of the ‘biogeographic core fauna’ in which host-lineage specificity is pronounced;
(3) phylogenetic analysis of the widespread freshwater trematode family
Allocreadiidae reveals a complex history of host-shifting and co-diversification
involving mainly cyprinodontiforms and characids; (4) allocreadiids, monogeneans and
spiruridan nematodes of Middle American cyprinodontiforms may provide clues to the
evolutionary history of their hosts; and (5) phylogenetic analyses of cryptogonimid
trematodes may reveal whether or how cichlids interacted with marine or
brackish-water environments during their colonization history. The review shows that
‘interchange’ is limited and asymmetrical, but simple narratives of northward
isthmian dispersal will likely prove inadequate to explain the historical
biogeography of many host–parasite associations in tropical Middle America,
particularly those involving poeciliids. Finally, our study highlights the urgent
need for targeted survey work across Middle America, focused sampling in river
drainages of Colombia and Venezuela, and deeper strategic sampling in other parts of
South America, in order to develop and test robust hypotheses about fish–parasite
associations in Middle America.
Africa is experiencing a rapid increase in adult obesity and associated cardiometabolic diseases (CMDs). The H3Africa AWI-Gen Collaborative Centre was established to examine genomic and environmental factors that influence body composition, body fat distribution and CMD risk, with the aim to provide insights towards effective treatment and intervention strategies. It provides a research platform of over 10 500 participants, 40–60 years old, from Burkina Faso, Ghana, Kenya and South Africa. Following a process that involved community engagement, training of project staff and participant informed consent, participants were administered detailed questionnaires, anthropometric measurements were taken and biospecimens collected. This generated a wealth of demographic, health history, environmental, behavioural and biomarker data. The H3Africa SNP array will be used for genome-wide association studies. AWI-Gen is building capacity to perform large epidemiological, genomic and epigenomic studies across several African counties and strives to become a valuable resource for research collaborations in Africa.
The first UK epizootic of highly pathogenic (HP) H5N1 influenza in wild birds occurred in 2008, in a population of mute swans that had been the subject of ornithological study for decades. Here we use an innovative combination of ornithological, phylogenetic and immunological approaches to investigate the ecology and age structure of HP H5N1 in nature. We screened samples from swans and waterbirds using PCR and sequenced HP H5N1-positive samples. The outbreak's origin was investigated by linking bird count data with a molecular clock analysis of sampled virus sequences. We used ringing records to reconstruct the age-structure of outbreak mortality, and we estimated the age distribution of prior exposure to avian influenza. Outbreak mortality was low and all HP H5N1-positive mute swans in the affected population were <3 years old. Only the youngest age classes contained an appreciable number of individuals with no detectable antibody responses to viral nucleoprotein. Phylogenetic analysis indicated that the outbreak strain circulated locally for ∼1 month before detection and arrived when the immigration rate of migrant waterbirds was highest. Our data are consistent with the hypothesis that HP H5N1 epizootics in wild swans exhibit limited mortality due to immune protection arising from previous exposure. Our study population may represent a valuable resource for investigating the natural ecology and epidemiology of avian influenza.
We present theoretical calculations for ohmic contact technology to wurtzite Silicon Carbide using thin Indium Gallium Nitride and Aluminium Indium Nitride cap layers. Spontaneous and piezoelectric polarization in Indium Gallium Nitride and Aluminium Indium Nitride cap layers gives rise to bound interface sheet charge density of the order of 1013 electrons per cm2, and built-in electric fields of the order of MV per cm. For Si-face p-type SiC, the large compressive strain in very thin InGaN and AlInN cap layers results in negative sheet charge densities and much lower tunneling widths for holes compared to bulk contacts. For C-face p-type SiC, pseudomorphic nitride layers yield no benefit over bulk contacts since positive interface sheet charge densities repel holes and give higher contact resistances. However, thick, relaxed cap layers lead to spontaneous polarization-based negative charge densities that attract holes, leading to lower contact resistances. The contributions of the heavy, light and split-off band holes to the total tunneling flux is taken into account in our calculations. All tunneling probabilities are calculated within the Wentzels-Kramers-Brillouin approximation. The presence of the appropriate cap layers leads to several orders of magnitude improvement in tunneling transmission probabilities, and in many cases, makes ohmic technology to SiC feasible. While the major difficulties are encountered for contacts to p-type SiC, the effect of cap-based polarization technology on contacts to n-type layers is also discussed in this paper. Our calculations have relevance to contact technology for bipolar devices built from wide band-gap wurtzite semiconductors like heterojunction bipolar transistors, light-emitting diodes and lasers.
Metallic Ag-nanoparticles have been synthesized by catalyst free chemical
and photochemical reduction processes. During photochemical synthesis, the
samples were illuminated independently by unpolarized and radially-polarized
continuous laser beams (λ = 632.8 nm). The nanoparticles were characterized by
bright-field transmission electron microscopy (TEM), linear absorption
spectroscopy and fluorescence excitation/emission spectroscopy. Compared to
other growth-conditions, sample prepared under radially polarized beam
essentially displays well-separated, spherical nanoparticles with a narrow
size distribution around average size of 6 nm. In addition, an outstanding
enhancement in the fluorescence as large as 39% has been achieved along
with observation of distinct localized surface plasmon states. Though the sample
produced under unpolarized light could exhibit discrete plasmon states,
better resolved states were observed in case of use of radially-polarized
beam. It is expected that the radially polarized light could induce
resonance energy transfer and hence could control growth conditions giving
rise to absolutely unclustered Ag-nanoparticles. Detecting such localized
surface plasmon states and understanding conditions of high quantum yield
would be promising for single molecule fluorescence, superresolution
microscopy and other nanoscopic applications.
PbS quantum dots (bare and silica coated) have been synthesized in PVA matrix with average size 10 nm and 9 nm. The capacitance-voltage (C − V) and current –voltage (I − V) response of both bare and coated quantum dots have been recorded in different frequency range (Hz–MHz). Both the samples show frequency dependent response except in case of C − V characteristics at MHz range. The I − V responses at low frequency range exhibit step like structures which could be attributed to 'Coulomb blockade'.
We present theoretical calculations for the effect of spontaneous and piezoelectric polarization on the base resistance and frequency response of wurtzite Aluminium Gallium Nitride / Silicon Carbide Heterojunction Bipolar Transistors. Heterojunction Bipolar Transistors ( HBTs ) built using wide band gap semiconductors with AlGaN emitter and SiC base/collector hold the promise of high-power and high-frequency operation due to lower impact ionization coefficients and higher breakdown voltages. Further, Silicon Carbide has an indirect bang gap, and a large lifetime of minority carriers compared to most other compound semiconductors, which tend to have direct band gaps. This reduces the base recombination factor when the base is made from SiC, and helps to achieve higher overall current gain. Spontaneous and piezoelectric polarizations of the order of 1013 electrons per cm2 exist in wurtzite wide band-gap semiconductors. This has a non-trivial effect on band profile, charge transport and overall device characteristics since the polarization-induced charges are of the same order of magnitude as the total dopant charge content of critical device layers, and can significantly affect the amount of mobile charge depletion or accumulation in these layers. We calculate the effect of this polarization for both very thin pseudomorphic emitters and for relaxed emitter structures. We present calculations for the cases of Si-face and C-face SiC, since the signs of polarization-induced charges are different for the two cases. The intrinsic base resistance near emitter flat-band conditions is changed by a factor of 10 depending on the alloy composition of the emitter and the polarity of growth. The maximum frequency of oscillation under emitter flat-band conditions can also be modulated by the polarization-induced charges by up to 60%. Our calculations show that the technologically less prevalent C-face SiC can give a higher advantage for frequency response, especially when the emitter thickness is larger than the critical thickness.
We report an atypical case of ossicular necrosis affecting the incus, in the absence of any history of chronic serous otitis media. We also discuss the current theories of incus necrosis.
A male patient presented with a history of right unilateral hearing loss and tinnitus. Audiometry confirmed right conductive deafness; tympanometry was normal bilaterally. He underwent a right exploratory tympanotomy, which revealed atypical erosion of the proximal long process of the incus. Middle-ear examination was otherwise normal, with a mobile stapes footplate. The redundant long process of the incus was excised and a partial ossicular replacement prosthesis was inserted, resulting in improved hearing.
Ossicular pathologies most commonly affect the incus. The commonest defect is an absent lenticular and distal long process of the incus, which is most commonly associated with chronic otitis media. This is the first reported case of ossicular necrosis, particularly of the proximal long process of the incus, in the absence of chronic middle-ear pathology.
We present numerical calculations of electron spectra of single and multiple coupled quantum dots based on Aluminium Gallium Nitride / Gallium Nitride heterostructures. The effect of spontaneous and piezoelectric polarization on the confinement potential seen by the electrons is taken into account through bound interface sheet charges. We also calculated the spectra without polarization effects for reference. For some quantum dot dimensions, the energy eigenvalues shift by several hundred meVs due to the polarization charges. We calculate the spectra for the two cases of box-shaped and cylindrical quantum dots. The latter case is an approximation to quantum dots with hexagonal-facet shapes recently reported in the literature. The quantum dots in our calculations are surrounded by vacuum in the lateral direction, but the same qualitative conclusions will hold if the dots are embedded in some material, as long as the barrier heights are large. For GaN vertical confinement of less than 30 angstroms, most of the bound states are associated with the lowest eigenvalue of the vertical confinement potential. This is also true for higher vertical confinement dimensions because the triangular potential seen by the electrons is the same for the lowest energy eigenstates. The electric field in the vertical direction is a strong function of the aluminium concentration in the AlGaN layer. As the AlGaN layer composition is varied from very high Al concentration to medium Al concentration, the spectra shift by several hundred meVs, referred to the onset of the continuous spectra. The transition frequencies between bound states and between bound and the lowest continuum states lie in the low to the high infra-red range, and can be varied over a wide range by both the dimensions and the barrier aluminium concentration. For the case of 4 coupled quantum dots formed by repeated AlGaN/GaN heterojunctions, we find that the polarization-induced electric fields lead to excessive band-bending and as a consequence there are fewer bound states compared to the spectrum calculated without polarization effects.
We present numerical calculations of tunneling through ultra thin wurtzite Gallium Nitride cap layers on p-doped wurtzite silicon carbide . We demonstrate the predominance of tunneling of the split-off holes to the total carrier flux, with the contribution of the heavy and the light holes damped by the large potential barrier. We calculate the contributions of spontaneous and piezoelectric polarizations to the tunneling profile seen by the holes. Two orders of magnitude enhancement is seen in the transmission probabilities for a 10 angstroms thick Gallium Nitride cap layer for holes very close to the valence band edge, compared to a barrier without any gallium nitride cap. The contact resistances are also calculated for the Gallium Nitride tunneling caps and more than two orders of magnitude lowering is seen with the ultra-thin caps. Larger cap widths induce hole accumulation layers, but the advantages of hole accumulation are offset by the higher effective tunneling width. Our calculations are relevant to nanostructures and nanodevices involving heterojunctions between gallium nitride and silicon carbide and provide the basis for low contact resistances with as-deposited metals. While our calculations focus on the regime of very high barriers to the metal of the order of 1.5 - 2 electron volts, where the method of ultra-thin caps is most useful, similar conclusions also hold for lower barrier heights.
Cygnus X-3, a Galactic X-ray binary, shows the presence of outflows in the form of radio jets. The SED in the X-ray band shows a complicated structure and evolution. We review some recent results of the long-term correlation of the radio and X-ray emissions, chiefly in the low (hard) states of the source. Comparing the results with those of other Galactic microquasars, we attempt to provide a consistent picture of the accretion — ejection mechanism in these sources.
The effect of hydrogen treatment at 200°C on the concentration of electrically active defects in LPE grown AIGaAsSb is reported. In n-type layers the electrical properties are shown to be dominated by DX-like deep donors of three different types all of which are strongly passivated by the hydrogen treatment as evidenced by C-V. DLTS C-T and spreading resistance measurements. In p-type layers intrinsic acceptors of defect origin are also passivated by hydrogen. Deuterium profiles in both n- and p-type layers show characteristic plateaus indicative of formation of neutral compexes between hydrogen and dopants. Hydrogen treatment also leads to decrease of the Au/n-AIGaAsSb Schottky barrier height from 1.3 to 0.85 eV.
In this paper we show that when grown by MBE at unusually high temperatures epitaxial layers of GaSb and GaAs are semi-insulating. In GaSb combination of Hall effect, TSC, SIMS and two probe resistivity profiling leads us to believe that high resistivity is due to production of midgap centers at elevated temperatures. No strong evidence of the prevalence of such midgap centers was obtained for high temperature GaAs layers and in this case we believe that high resistivity is associated with the formation of Ga-related precipitates acting as internal Schottky barriers.
Quantum well interdiffusion has been employed, for the First time in the quaternary InGaAsP/InP system (grown lattice matched to InP substrates), in order to modify the as-grown, nominally square, shapes of single quantum wells so as to increase their bandgap energies. This was accomplished, in a spatially selective manner, by using low energy ion implantation through a mask to generate vacancies. Subsequent rapid thermal annealing drove these vacancies down to the quantum wells where their presence enhanced the thermally driven interdiffusion of atoms between the well and barrier layers. The goal of this work is to develop a simple process for the integration of optoelectronic devices with differing functions.