A Regular Demand System with Commodity-Specific Demographic Effects

Regular consumer demand systems almost invariably employ specifications that involve common functional forms in all equations. When applications involve crosssectional data it is often the case that demographic effects are important. However it is plausible that demographic effects are commodity-specific. In this case, there may be a loss of efficiency if a common functional form across commodities is imposed artificially by entering redundant explanators in demand equations for which specific demographic influences are unwarranted. This paper explores an approach to specifying a complete system of demand equations which is fully regular but which nevertheless allows for commodity-specific variation in the functional form of the demand equations.Consumer Economics: Theory, Consumer Economics: Empirical Analysis, Demographic Economics

Genomic Approaches to the Study of HIV-1 Acquisition

Host genome studies are increasingly available for the study of infectious disease susceptibility. Current technologies include large-scale genotyping, genome-wide screens such as transcriptome and silencing (silencing RNA) studies, and increasingly, the possibility to sequence complete genomes. These approaches are of interest for the study of individuals who remain uninfected despite documented exposure to human immunodeficiency virus type 1. The main limitation remains the ascertainment of exposure and establishing large cohorts of informative individuals. The pattern of enrichment for CCR5 Δ32 homozygosis should serve as the standard for assessing the extent to which a given cohort (of white subjects) includes a large proportion of exposed uninfected individual

Prevalence of iron deficiency in 62,685 women of seven race/ethnicity groups: The HEIRS Study.

BackgroundFew cross-sectional studies report iron deficiency (ID) prevalence in women of different race/ethnicity and ages in US or Canada.Materials and methodsWe evaluated screening observations on women who participated between 2001-2003 in a cross-sectional, primary care-based sample of adults ages ≥25 y whose observations were complete: race/ethnicity; age; transferrin saturation; serum ferritin; and HFE p.C282Y and p.H63D alleles. We defined ID using a stringent criterion: combined transferrin saturation <10% and serum ferritin <33.7 pmol/L (<15 μg/L). We compared ID prevalence in women of different race/ethnicity subgrouped by age and determined associations of p.C282Y and p.H63D to ID overall, and to ID in women ages 25-44 y with or without self-reported pregnancy.ResultsThese 62,685 women included 27,079 whites, 17,272 blacks, 8,566 Hispanics, 7,615 Asians, 449 Pacific Islanders, 441 Native Americans, and 1,263 participants of other race/ethnicity. Proportions of women with ID were higher in Hispanics and blacks than whites and Asians. Prevalence of ID was significantly greater in women ages 25-54 y of all race/ethnicity groups than women ages ≥55 y of corresponding race/ethnicity. In women ages ≥55 y, ID prevalence did not differ significantly across race/ethnicity. p.C282Y and p.H63D prevalence did not differ significantly in women with or without ID, regardless of race/ethnicity, age subgroup, or pregnancy.ConclusionsID prevalence was greater in Hispanic and black than white and Asian women ages 25-54 y. p.C282Y and p.H63D prevalence did not differ significantly in women with or without ID, regardless of race/ethnicity, age subgroup, or pregnancy

Associations between diabetes and both cardiovascular disease and all-cause mortality are modified by grip strength: evidence from UK Biobank, a prospective population-based cohort study

OBJECTIVE Grip strength and diabetes are predictors of mortality and cardiovascular disease (CVD), but whether these risk factors interact to predispose to adverse health outcomes is unknown. This study determined the interactions between diabetes and grip strength and their association with health outcomes. RESEARCH DESIGN AND METHODS We undertook a prospective, general population cohort study by using UK Biobank. Cox proportional hazards models were used to explore the associations between both grip strength and diabetes and the outcomes of all-cause mortality and CVD incidence/mortality as well as to test for interactions between diabetes and grip strength. RESULTS 347,130 UK Biobank participants with full data available (mean age 55.9 years, BMI 27.2 kg/m2, 54.2% women) were included in the analysis, of which 13,373 (4.0%) had diabetes. Over a median follow-up of 4.9 years (range 3.3–7.8 years), 6,209 died (594 as a result of CVD), and 4,301 developed CVD. Participants with diabetes were at higher risk of all-cause and CVD mortality and CVD incidence. Significant interactions (P < 0.05) existed whereby the risk of CVD mortality was higher in participants with diabetes with low (hazard ratio [HR] 4.05 [95% CI 2.72, 5.80]) versus high (HR 1.46 [0.87, 2.46]) grip strength. Similar results were observed for all-cause mortality and CVD incidence. CONCLUSIONS Risk of adverse health outcomes among people with diabetes is lower in those with high grip strength. Low grip strength may be useful to identify a higher-risk subgroup of patients with diabetes. Intervention studies are required to determine whether resistance exercise can reduce risk

Synthesis and characterisation of Li11RE18M4O39−δ: RE = Nd or Sm; M = Al, Co or Fe

Four new phases of general formula, Li11RE18M4O39−δ: REM = NdAl, NdCo, SmCo, SmFe, have been synthesised and characterised. The NdAl phase, and probably the others, is isostructural with the NdFe analogue, but some cation disorder and partial site occupancies prevent full structural refinement of powder neutron diffraction data. The NdCo phase also forms a solid solution with variable Li content (and charge compensation by either oxygen vacancies or variable transition metal oxidation state). The NdAl phase is a modest conductor of Li+ ions whereas the other three phases are electronic conductors, attributed to mixed valence of the transition metal ions. Subsolidus phase diagrams for the systems Li2O–Nd2O3– Al2O3, ‘CoO’ have been determined and an additional new phase, LiCoNd4O8, which appears to have a K2NiF4-related superstructure, identified

The 25 November 1988 Saguenay, Quebec, Earthquake: Source Parameters and the Attenuation of Strong Ground Motion

The Saguenay earthquake of 25 November 1988 occurred close to the southern margin of the Saguenay Graben in southern Quebec. It was caused by almost purely dip-slip faulting centered at a depth of 26 km with a P axis oriented northeast-southwest. This faulting mechanism is similar to those of the larger historical earthquakes in eastern North America, but the focal depth is substantially greater than all but one of these events. The seismic moment estimated from regional PnI waves and teleseismic long-period body waves is 5 × 10^(24) dyne-cm., corresponding to a moment magnitude of 5.8. The source duration of the earthquake is estimated to be 1.8 sec, corresponding to a stress drop of 160 bars, which is not significantly higher than the average stress drop of 120 bars estimated from previous large earthquakes in eastern North America. In order to simultaneously match the recorded ground motion amplitudes of strong-motion acceleration, strong-motion velocity, and teleseismic short-period and long-period body waves, it is necessary to use a source function having a complex shape that implies the presence of asperities and larger local stress drops. The large set of strong-motion recordings of the Saguenay earthquake has been used to validate a procedure for estimating strong ground motion attenuation based on a simple wave propagation model. The most important feature of the recorded strong motions is that their peak amplitudes do not decay significantly with distance inside 120 km, but then decay abruptly beyond 120 km. Profiles of recorded accelerograms with absolute times indicate that at distances beyond 64 km the peak ground motions are due to strong postcritical reflections from velocity gradients in the lower crust. The principal shear-wave arrivals and the variation of their peak amplitudes with distance were reproduced in synthetic seismograms generated using a regional crustal structure model. The critical distances for the postcritical reflections were short because of the deep focal depth of the event, causing the elevation of ground motion amplitudes out to 120 km. Similar studies of earthquakes in other regions of eastern North America indicate that the strength of the postcritical reflections, and the distance ranges over which they are dominant, are controlled by the focal depth and crustal structure. Regional variations in crustal structure thus give rise to predictable regional variations in strong ground motion attenuation

Mind how you cross the gap! Outcomes for young people who failed to make the transition from child to adult services : the TRACK study

Aims and method: The Transitions of Care from Child and Adolescent Mental Health Services to Adult Mental Health Services (TRACK) study was a multistage, multicentre study of adolescents' transitions between child and adult mental health services undertaken in England. We conducted a secondary analysis of the TRACK study data to investigate healthcare provision for young people (n = 64) with ongoing mental health needs, who were not transferred from child and adolescent mental health services (CAMHS) to adult mental health services mental health services (AMHS). Results: The most common outcomes were discharge to a general practitioner (GP; n = 29) and ongoing care with CAMHS (n = 13), with little indication of use of third-sector organisations. Most of these young people had emotional/neurotic disorders (n = 31, 48.4%) and neurodevelopmental disorders (n = 15, 23.4%). Clinical implications: GPs and CAMHS are left with the responsibility for the continuing care of young people for whom no adult mental health service could be identified. GPs may not be able to offer the skilled ongoing care that these young people need. Equally, the inability to move them decreases the capacity of CAMHS to respond to new referrals and may leave some young people with only minimal support

Process, outcome and experience of transition from child to adult mental healthcare : multiperspective study

Background Many adolescents with mental health problems experience transition of care from child and adolescent mental health services (CAMHS) to adult mental health services (AMHS). Aims As part of the TRACK study we evaluated the process, outcomes and user and carer experience of transition from CAMHS to AMHS. Method We identified a cohort of service users crossing the CAMHS/AMHS boundary over 1 year across six mental health trusts in England. We tracked their journey to determine predictors of optimal transition and conducted qualitative interviews with a subsample of users, their carers and clinicians on how transition was experienced. Results Of 154 individuals who crossed the transition boundary in 1 year, 90 were actual referrals (i.e. they made a transition to AMHS), and 64 were potential referrals (i.e. were either not referred to AMHS or not accepted by AMHS). Individuals with a history of severe mental illness, being on medication or having been admitted were more likely to make a transition than those with neurodevelopmental disorders, emotional/neurotic disorders and emerging personality disorder. Optimal transition, defined as adequate transition planning, good information transfer across teams, joint working between teams and continuity of care following transition, was experienced by less than 5% of those who made a transition. Following transition, most service users stayed engaged with AMHS and reported improvement in their mental health. Conclusions For the vast majority of service users, transition from CAMHS to AMHS is poorly planned, poorly executed and poorly experienced. The transition process accentuates pre-existing barriers between CAMHS and AMH