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Objectives: Prior research has identified numerous genetic (including sex), education, health, and lifestyle factors that predict cognitive decline. Traditional model selection approaches (e.g., backward or stepwise selection) attempt to find one model that best fits the observed data, risking interpretations that only the selected predictors are important. In reality, several predictor combinations may fit similarly well but result in different conclusions (e.g., about size and significance of parameter estimates). In this study, we describe an alternative method, Information-Theoretic (IT) model averaging, and apply it to characterize a set of complex interactions in a longitudinal study on cognitive decline. Methods: Here, we used longitudinal cognitive data from 1256 late–middle aged adults from the Wisconsin Registry for Alzheimer’s Prevention study to examine the effects of sex, apolipoprotein E (APOE) ɛ4 allele (non-modifiable factors), and literacy achievement (modifiable) on cognitive decline. For each outcome, we applied IT model averaging to a set of models with different combinations of interactions among sex, APOE, literacy, and age. Results: For a list-learning test, model-averaged results showed better performance for women versus men, with faster decline among men; increased literacy was associated with better performance, particularly among men. APOE had less of an association with cognitive performance in this age range (∼40–70 years). Conclusions: These results illustrate the utility of the IT approach and point to literacy as a potential modifier of cognitive decline. Whether the protective effect of literacy is due to educational attainment or intrinsic verbal intellectual ability is the topic of ongoing work. (JINS, 2019, 25, 119–133)
Berseem clover (Trifolium alexandrinum L.) is an important forage legume and is the primary winter forage crop in Pakistan. There are significant gaps in yield potential among varieties of berseem clover, as well as yields obtained at research stations and on-farm. To address this problem a survey of farmers was undertaken in the districts of Kasur and Okara, Punjab, Pakistan to determine the level of knowledge and understanding of berseem forage cultivation and seed production. The study comprised 44% smallholder (<3 ha), 26% medium (3–5 ha) and 30% large farmers (>5 ha) with average age of 42 years. Most farmers had little or no knowledge of the role of seed quality, inoculation with rhizobium, pollination, fertiliser use, irrigation management and the importance of forage nutritional value in improving livestock productivity. Most farmers (56%) had received no input from the government or private sector to improve forage production, relying instead on traditional knowledge. Knowledge of the importance of land preparation (95%), sowing rate (98%) and insect and pest management (75%) was higher than seed selection and fertilisation. Adoption of improved varieties (3%) and production technologies (14%) was low due to various constraints including ignorance, high cost of inputs, lack of availability of inputs in the market and a perceived high level of financial risk. Almost 100% of the respondents agreed that seed of improved varieties was a pre-requisite for higher forage and seed production as well as essential to start village-based forage seed enterprises.
The diagnosis of psychosis is based on the presence or absence of characteristic symptoms. The presence of such symptoms varies during the course and treatment, raising the question of diagnostic stability after a first psychotic episode.
Aims and objectives
The aim of this study is to evaluate the diagnostic stability after a first psychotic episode in the long term (five years after the first inpatient admission).
A retrospective study that included patients with first psychotic episode between 2007 and 2011 admitted to the inpatient unit of the psychiatry and mental health clinic of São João hospital center, Oporto, Portugal and re-evaluation of the diagnosis after five years.
We included 60 patients with a first psychosis episode, 22 of which were drop-outs after five years. Of the 38 patients evaluated, it was possible to see that after 5 years 68.4% (n = 26) maintained the same diagnosis during follow-up. In particular, the diagnosis of schizophrenia was kept in 83.3% of patients after 5 years (n = 15, 18 patients with the diagnosis of schizophrenia after first admission). Diagnosis of acute and transient psychotic disorder and psychosis not otherwise specified were the least stable diagnosis after 5 years.
The diagnosis after a first psychotic episode has important therapeutic and prognostic implications. The presence of characteristic symptomatology, with periods of partial or total remission between subsequent episodes emphasizes the need for regular monitoring, since this group of patients appears to be more vulnerable to changes in diagnosis over time.
Disclosure of interest
The authors have not supplied their declaration of competing interest.
The purpose of the present study was to determine the effects of short-term supplementation with the free acid form of β-hydroxy-β-methylbutyrate (HMB-FA) on indices of muscle damage, protein breakdown, recovery and hormone status following a high-volume resistance training session in trained athletes. A total of twenty resistance-trained males were recruited to participate in a high-volume resistance training session centred on full squats, bench presses and dead lifts. Subjects were randomly assigned to receive either 3 g/d of HMB-FA or a placebo. Immediately before the exercise session and 48 h post-exercise, serum creatine kinase (CK), urinary 3-methylhistadine (3-MH), testosterone, cortisol and perceived recovery status (PRS) scale measurements were taken. The results showed that CK increased to a greater extent in the placebo (329 %) than in the HMB-FA group (104 %) (P= 0·004, d= 1·6). There was also a significant change for PRS, which decreased to a greater extent in the placebo (9·1 (sem 0·4) to 4·6 (sem 0·5)) than in the HMB-FA group (9·1 (sem 0·3) to 6·3 (sem 0·3)) (P= 0·005, d= − 0·48). Muscle protein breakdown, measured by 3-MH analysis, numerically decreased with HMB-FA supplementation and approached significance (P= 0·08, d= 0·12). There were no acute changes in plasma total or free testosterone, cortisol or C-reactive protein. In conclusion, these results suggest that an HMB-FA supplement given to trained athletes before exercise can blunt increases in muscle damage and prevent declines in perceived readiness to train following a high-volume, muscle-damaging resistance-training session.
The aims of this study were to define the basic epidemiology of serologically confirmed acute Q fever in patients tested via the Townsville Hospital laboratory from 2000 to 2010 and to determine the impact of geographical location and seasonality on the incidence of acute cases in the Townsville region. Seven Statistical Local Areas (SLA) were identified as having an incidence higher than the average Queensland incidence over the study period. The SLA with the highest incidence was Woodstock-Ross with 24·9 cases/100 000. A clear seasonal peak was found, with the greatest number of cases observed in May, 3 months following the peak in rainfall in February. We hypothesize that an increase in wildlife numbers and drier conditions seen immediately following the wet season is the reason for the seasonal peak of human acute Q fever cases in Townsville.
Burkholderia pseudomallei, the causative agent of melioidosis is associated with soil. This study used a geographic information system (GIS) to determine the spatial distribution of clinical cases of melioidosis in the endemic suburban region of Townsville in Australia. A total of 65 cases over the period 1996–2008 were plotted using residential address. Two distinct groupings were found. One was around the base of a hill in the city centre and the other followed the old course of a major waterway in the region. Both groups (accounting for 43 of the 65 cases examined) are in areas expected to have particularly wet topsoils following intense rainfall, due to soil type or landscape position.
We present an attempt to clarify the valence band order of ZnO and MgxZn1−xO films grown by pulsed laser deposition (PLD) on sapphire substrates. We derive the dependence of spin orbit interaction (Δso) and crystal field interaction (Δcf) on the temperature, strain and cation replacement (Zn with Mg) and compared this with theoretical predictions. The strain was varied by using different orientated sapphire substrates (c-, r-, and m-plane orientations) and by varying the film thicknesses. All these investigations support the conclusion that the symmetry order of the valence band is Γ7-Γ9-Γ7 for ZnO and MgxZn1−xO for x ≤ 0.55.
ZnO is a very promising material for spintronics applications, with many groups reporting room temperature ferromagnetism in films doped with transition metals during growth or by ion implantation. In films doped with Mn during PLD, we find an inverse correlation between magnetization and electron density as controlled by Sn doping. The saturation magnetization and coercivity of the implanted single-phase films were both strong functions of the initial anneal temperature, suggesting that carrier concentration alone cannot account for the magnetic properties of ZnO:Mn and factors such as crystalline quality and residual defects play a role. Plausible mechanisms for the ferromagnetism include the bound magnetic polaron model or exchange is mediated by carriers in a spin-spilt impurity band derived from extended donor orbitals. Spin-dependent phenomena in ZnO may lead to devices with new or enhanced functionality, such as polarized solid-state light sources and sensitive biological and chemical sensors.
The establishment, in 2000 and 2003, of new degree programs in Photovoltaics and Solar Energy Engineering and Renewable Energy Engineering at the Centre for Photovoltaic Engineering at the University of New South Wales, Sydney was in response to predictions, now being fulfilled, of dramatic global market and employment growth. They were developed by the well established photovoltaics research group at UNSW that has produced many important advances, including two commercially important solar cell technologies. Materials-related education in these programs are mainly focussed on the photovoltaic aspects, including study of the fundamental optical, electronic, phononic and excitonic properties of silicon, crystal structure, semiconductor properties, doping and contacts. Cell manufacturing is taught in detail, including by the use of an interactive virtual production line. Practical projects, taking advantage of a large and active research group, are one of the most important and effective educational tools in both these programs. The Centre also administers postgraduate coursework and research programs.
The National Science Foundation created the National Science Digital Library (NSDL) in order to establish a technical, communal, and organizational framework for access to high quality resources and tools that support innovations in teaching and learning at all levels of science, technology, engineering, and mathematics education. As part of the NSDL, the Materials Digital Library (MatDL) Pathway focuses specifically on serving the materials science (MS) community with a target audience that includes MS undergraduate and graduate students, educators, and researchers. MatDL is a collaborative effort involving the Materials Science and Engineering Laboratory at the National Institute of Standards and Technology, Kent State University, Massachusetts Institute of Technology, University of Michigan, Iowa State University, and Purdue University. Our network of collaborations also includes a Nanoscience Interdisciplinary Research Team, Materials Research Science and Engineering Center, and International Materials Institute. A primary goal of MatDL is to bring materials science research and education closer together. MatDL provides innovative uses of digital libraries and the web as educational media in the MS community with particular emphasis on providing: 1) tools to describe, manage, exchange, archive, and disseminate scientific data 2) workspace for open access development of modeling and simulation tools 3) services and content for virtual labs in large undergraduate introductory science courses, and 4) workspace for collaborative development of core undergraduate MS teaching resources for emerging areas. This paper will provide an overview of the NSDL MatDL Pathway, details about specific aspects of the project, as well as interactions between research and education.
An environmental surveillance programme was developed to determine whether water supplies could be a source of Burkholderia pseudomallei as noted during previous melioidosis outbreak investigations. Water supplies to communities in the three northern Australian jurisdictions (Western Australia, Northern Territory and Queensland) were sampled periodically during 2001 and 2002. Water and soil samples were collected from communities known to have had recent culture-positive melioidosis cases and nearby communities where no cases had been diagnosed. Clinical isolates of B. pseudomallei obtained from northern Australian patients during 2001 and 2002 were compared with the environmental B. pseudomallei isolates by ribotyping and pulsed-field gel electrophoresis. B. pseudomallei was isolated from 11 distinct locations, all in the Northern Territory, seven of which were associated with culture-positive melioidosis cases (>1 case at three locations). Water was implicated as a possible environmental source of melioidosis in six locations. A variety of free-living amoebae including Acanthamoeba and Hartmannella spp. that are potential hosts to B. pseudomallei were recovered from environmental specimens. Culturable B. pseudomallei was not found to be widely dispersed in the environments sampled.
Velo-cardio-facial syndrome (VCFS) is associated with interstitial deletions of chromosome 22q11. About 30% of patients with VCFS have psychosis, and the rate of these deletions in schizophrenia has been reported to be about 1%. Even higher rates of VCFS deletions have been reported for childhood-onset schizophrenia.
To test the hypothesis that there is an increased rate of VCFS among patients with early-onset psychosis (age at onset < 18 years). We screened 192 early-onset patients and 329 patients with adult-onset schizophrenia.
We genotyped the patients and 444 healthy controls for hemizygosity of five microsatellite markers and one single nucleotide polymorphism that map to the 22q11-deleted region.
One patient had a VCFS deletion, confirmed with semi-quantitative polymerase chain reaction. None of the controls showed a pattern of genotypes consistent with hemizygosity.
VCFS may be less frequent among patients with psychosis than previously suggested; this rate is not increased among early-onset patients.
Existing semiconductor electronic and photonic devices utilize the charge on electrons and holes in order to perform their specific functionality such as signal processing or light emission. The relatively new field of semiconductor spintronics seeks, in addition, to exploit the spin of charge carriers in new generations of transistors, lasers and integrated magnetic sensors. The ability to control of spin injection, transport and detection leads to the potential for new classes of ultra-low power, high speed memory, logic and photonic devices. The utility of such devices depends on the availability of materials with practical (>300K) magnetic ordering temperatures. In this paper, we summarize recent progress in dilute magnetic semiconductors such as (Ga,Mn)N, (Ga,Mn)P and (Zn,Mn)O exhibiting room temperature ferromagnetism, the origins of the magnetism and its potential applications in novel devices such as spin-polarized light emitters and spin field effect transistors.
Silicon carbide (SiC) thin films are attractive for a wide range of applications ranging from microelectronic and opto-electronic devices to protective and tribological coatings. In this paper, we will demonstrate that silicon carbide films can be successfully deposited by pulsed laser deposition (PLD) technique over large areas, with good uniformity in thickness, composition, and film-specific properties.
Amorphous SiC films were grown on silicon wafers of 75-mm diameter over a temperature range of 25 – 650°C using a KrF excimer laser at a wavelength 248 nm and a repetition rate of 100 Hz. The large-area uniform coverage was obtained by rastering the laser beam over the radius of a rotating SiC target of 90-mm diameter, while the substrate was rotated simultaneously. The uniformity of film composition over the 75-mm wafers was characterized by Auger electron spectroscopy (AES), while the crystallinity of films was investigated by X-ray diffraction (XRD). The morphology of the films was evaluated using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The thickness of the coatings, and the index of refraction, n, along the wafer radii were measured optically using a spectrophotometer.
Evidence exists for an association between aggression and schizophrenia. Although the aetiology of aggression is multifactorial, three studies have reported associations between polymorphisms of the catechol-O-methyltransferase (COMT) gene and aggression in schizophrenia.
To replicate these findings in a larger sample using the Overt Aggression Scale (OAS).
A sample of 180 people with DSM–IV schizophrenia were rated for aggression using the OAS. Kruskal–Wallis and contingency table analyses were applied to the OAS results.
The high-activity homozygotes showed significantly higher scores of aggression, whereas the heterozygotes showed significantly lower scores. The odds ratio for aggression for the high-activity homozygotes was 2.07 (95% Cl=1.03–4.15), whereas that for the heterozygotes was 0.54 (95% CI=0. 30–1.00).
The high-activity COMT homozygote confers a higher risk of recorded aggression in schizophrenia. Heterozygotes had a significantly lower risk, which may represent an example of heterosis/heterozygote advantage.
In an ongoing effort to investigate plasma plume features yielding high quality DLC films, we have applied plasma plume diagnosis and film characterization to examine plume character distinction from KrF laser ablation of both amorphous carbon (a-C) and single crystal graphite (SCG) targets- The advancing plasma plume produced by these structurally different targets are observed to possess quantitatively similar total heavy particle inventory, ionized fraction, and electron thermal content, yet quite different ion kinetic energy, plume profile, C2 formation mechanism, and concentration of complex molecules. All data support the conclusion that the SCG target plasma plume is populated with heavier, more complex molecules than those in a-C which have been shown to be predominantly comprised of C and C+ under vacuum conditions with the addition of C2 at high fill pressure. Significantly smaller plume profile peaking factor, less energetic and slightly lower temperature plume conditions, laser energy (E1) dependent plume peaking, harder films produced at lower El strongly heterogeneous films, and lesser plume energy attenuation in high pressure background fill in SCG target plumes all support the conclusion of more massive plume species in SCG target plumes. Energy balance estimates indicate that ion kinetic energy dominates and that SCG target ablation liberates about twice the number of 12C atoms per unit El.