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For exploring the prospect of higher-k dielectric phase engineering on a high
mobility substrate, films of Hf1-xZrxO2 with
varying x-values (0 ≤ x ≤ 1) were deposited on
Al2O3 passivated Ge substrates using atomic layer
deposition (ALD) with a cyclic deposit-anneal-deposit-anneal (DADA) scheme. The
evolution of monoclinic to higher-k tetragonal structure with increasing
ZrO2 concentration was probed by grazing incident x-ray
diffraction and partial reciprocal space maps using the highly brilliant
synchrotron x-ray source at the Cornell High Energy Synchrotron Source (CHESS).
A primarily amorphous/nano-crystalline matrix of the asdeposited films changed
to randomly aligned grains of nanocrystalline MO2 (M=Hf, Zr)
after post deposition annealing at 800 °C for 200 seconds. In contrast,
the DADA films annealed for same thermal budget showed high degree of preferred
orientation along certain crystallographic directions. With increasing
ZrO2 content, the structure of the films changed from a monoclinic to
a tetragonal phase. A lower amount of ZrO2 (x = 0.33) was
required for stabilizing the tetragonal phase in films grown on
Al2O3 passivated Ge substrate as compared to similar
films grown on a Si substrate via the same DADA process (x ≥
Low vitamin B12 status is common in older people; however, its public health significance in terms of neurological manifestations remains unclear. The present systematic review evaluated the association of vitamin B12 status with neurological function and clinically relevant neurological outcomes in adults aged 50+ years. A systematic search of nine bibliographic databases (up to March 2013) identified twelve published articles describing two longitudinal and ten cross-sectional analyses. The included study populations ranged in size (n 28–2287) and mean/median age (range 65–81 years). Studies reported various neurological outcomes: nerve function; clinically measured signs and symptoms of nerve function; self-reported neurological symptoms. Studies were assessed for risk of bias, and results were synthesised qualitatively. Among the general population groups of older people, one longitudinal study reported no association, and four of seven cross-sectional studies reported limited evidence of an association of vitamin B12 status with some, but not all, neurological outcomes. Among groups with clinical and/or biochemical evidence of low vitamin B12 status, one longitudinal study reported an association of vitamin B12 status with some, but not all, neurological outcomes and three cross-sectional analyses reported no association. Overall, there is limited evidence from observational studies to suggest an association of vitamin B12 status with neurological function in older people. The heterogeneity and quality of the evidence base preclude more definitive conclusions, and further high-quality research is needed to better inform understanding of public health significance in terms of neurological function of vitamin B12 status in older people.
Intestinal health is important for maximising the health, welfare, and performance of poultry. In addition, intestinal health issues in poultry can have devastating financial impacts for producers, and food safety concerns for consumers. Until recently, intestinal health issues were seen as a handful of known infectious agents leading to a set of severe and identifiable named diseases. There is however an emerging area which depicts intestinal health as a more complex and multifaceted system than previously known. Recent progress in technology suitable for microbial community analysis has evolved our understanding of the chicken intestinal microbiome. It is now understood that shifts in the composition of microbial communities can occur. These shifts can result in a series of implications, including: disease, welfare, environmental, and food safety concerns. Minor shifts in intestinal microbial balance can result in a wide continuum of disease presentations ranging from severe to mild clinical, subclinical or asymptotic. Differential diagnosis of poultry intestinal health issues may be challenging and is important for applying appropriate treatment options. This review discusses new and emerging topics in broiler chicken intestinal health, with a focus on microbial composition, newly discovered microbial shifts in classical poultry diseases, range in severity of enteric diseases, newly identified organisms in normal intestinal flora, implications of shifts in intestinal microbial communities and diagnosis of emerging intestinal health issues in poultry.
The Roman town of Forum Novum lies in the Sabine hills to the northeast of Rome. Its study forms part of the British School at Rome's Tiber Valley Project, a collaborative research initiative which studies the Tiber valley as the hinterland of Rome, tracing the impact of Rome's development on the history of its settlement, economy, and cultural identity from 1000 B.C. to A.D. 1300 (Patterson and Millett 1999; Patterson et al. 2000) (fig. 1). The project draws on the extensive work carried out in this area to produce a new, material-based history of the valley. While the project seeks to re-evaluate past survey material, a vital contrast is provided by the development of new field projects to fill the gaps in settlement knowledge. Three main lacunae have been identified: the study of urban centres; the dearth of data from the E bank of the Tiber; and the poor understanding of the late-antique and early Mediaeval landscape. Forum Novum offers an opportunity to address all these lacunae.
Urbanism forms a key research theme for the Tiber Valley Project. In marked contrast to the intensity of archaeological work on rural settlement in this area, there has been little systematic research on towns. Study has tended to concentrate on the excavation of monumental structures or, more rarely, the investigation of single and exceptional towns such as Ostia and Rome itself. Surprisingly little is known of the organization of the smaller towns and knowledge of their history is based largely on the epigraphic and documentary evidence.
The redshifted 21cm line of neutral hydrogen (Hi), potentially observable at low radio frequencies (~50–200 MHz), should be a powerful probe of the physical conditions of the inter-galactic medium during Cosmic Dawn and the Epoch of Reionisation (EoR). The sky-averaged Hi signal is expected to be extremely weak (~100 mK) in comparison to the foreground of up to 104 K at the lowest frequencies of interest. The detection of such a weak signal requires an extremely stable, well characterised system and a good understanding of the foregrounds. Development of a nearly perfectly (~mK accuracy) calibrated total power radiometer system is essential for this type of experiment. We present the BIGHORNS (Broadband Instrument for Global HydrOgen ReioNisation Signal) experiment which was designed and built to detect the sky-averaged Hi signal from the EoR at low radio frequencies. The BIGHORNS system is a mobile total power radiometer, which can be deployed in any remote location in order to collect radio frequency interference (RFI) free data. The system was deployed in remote, radio quiet locations in Western Australia and low RFI sky data have been collected. We present a description of the system, its characteristics, details of data analysis, and calibration. We have identified multiple challenges to achieving the required measurement precision, which triggered two major improvements for the future system.
Executive functions (EF) are a complex set of neurodevelopmental, higher-ordered processes that are especially salient during adolescence. Disruptions to these processes are predictive of psychiatric problems in later adolescence and adulthood. The objectives of the current study were to characterize the latent structure of EF using bifactor analysis and to investigate the independent and interactive effects of genes and environments on EF during adolescence. Using a representative young adolescent sample, we tested the interaction of a polymorphism in the serotonin transporter gene (5-HTTLPR) and parental supervision for EF through hierarchical linear regression. To account for the possibility of a hierarchical factor structure for EF, a bifactor analysis was conducted on the eight subtests of the Delis-Kaplan Executive Functions System (D-KEFS). The bifactor analysis revealed the presence of a general EF construct and three EF subdomains (i.e., conceptual flexibility, inhibition, and fluency). A significant 5-HTTLPR by parental supervision interaction was found for conceptual flexibility, but not for general EF, fluency or inhibition. Specifically, youth with the L/L genotype had significantly lower conceptual flexibility scores compared to youth with S/S or S/L genotypes given low levels of parental supervision. Our findings indicate that adolescents with the L/L genotype were especially vulnerable to poor parental supervision on EF. This vulnerability may be amenable to preventive interventions. (JINS, 2014, 20, 62–73)
Environmental influences on the rate of Alzheimer's disease (AD) progression have received little attention. Our objective was to test hypotheses concerning associations between caregiver personality traits and the rate of AD progression.
Care receivers (CR) were 161 persons with AD from a population-based dementia progression study; 55 of their caregivers were spouses and 106 were adult children. Cognitive status of the CR was measured with the Mini-Mental State Examination every six months, over an average of 5.6 (range: 1–14) years. Linear mixed models tested rate of cognitive decline as a function of caregiver personality traits from the NEO Five-Factor Inventory.
Significantly faster cognitive decline was observed with higher caregiver Neuroticism overall; however, in stratified models, effects were significant for adult child but not spouse caregivers. Neuroticism facets of depression, anxiety, and vulnerability to stress were significantly associated with faster decline. Higher caregiver Extraversion was associated with slower decline in the CR when caregivers were adult children but not spouses.
For adult child caregivers, caregiver personality traits are associated with rate of cognitive decline in CRs with AD regardless of co-residency. Results suggest that dementia caregiver interventions promoting positive care management strategies and ways to react to caregiving challenges may eventually become an important complement to pharmacologic and other approaches aimed at slower rate of decline in dementia.
In this study the length scale dependence of the operative mechanisms of time-dependent plastic deformation was studied using room temperature compression tests performed on Au micro-pillars and micro-spheres of 1.0 to 5.0 µm diameter. All the samples tested displayed deformation that had a component of random strain jumps. In the case of the Au micro-pillars, the frequency of the strain jumps showed a bilinear dependence upon pillar diameter with the frequency being larger, and more sensitive to diameter, when the pillar diameter was small (and τR was high). We suggest that this indicates a transition from deformation occurring by deformation on multiple slip planes to deformation occurring predominantly by single-plane dislocation slip when the pillar diameter is less than 2 µm.
The strain jump frequency during the constant-load micro-pillar creep tests showed a linear dependence upon τR. Creep tests performed on the micro-spheres of 5.0 µm diameter displayed displacement jump frequency that was essentially independent of the applied load while the jump frequency increased with increasing load for the smaller 2.5 µm diameter micro-spheres. We suggest that this difference is related to the volume of the micro-sphere. When the volume is small, the component of the deformation that occurs by a stochastic dislocation glide process is increased and becomes strongly dependent upon the magnitude of the local shear stress.