The complexity of drinking: Interactions between the cognitive and behavioural determinants of alcohol consumption

This study expanded the earlier work conducted by this laboratory ( Hasking, P.A. and Oei, T.P.S. (2002a) . The differential role of alcohol expectancies, drinking refusal self-efficacy and coping resources in predicting alcohol consumption in community and clinical samples. Addiction Research and Theory , 10 , 465-494), by examining the independent and interactive effects of avoidant coping strategies, positive and negative expectancies and self-efficacy, in predicting volume and frequency of alcohol consumption in a sample of community drinkers. Differential relationships were found between the variables when predicting the two consumption measures. Specifically, while self-efficacy, seeking social support for emotional reasons and using drugs or alcohol to cope were independently related to both volume and frequency of drinking, complex interactions with positive and negative alcohol expectancies were also found. These interactions are discussed in terms of the cognitive and behavioural mechanisms thought to underlie drinking behaviour.

Determinants in the development of advanced nursing practice: a case study of primary-care settings in Hong Kong

Different factors have been shown to influence the development of models of advanced nursing practice (ANP) in primary-care settings. Although ANP is being developed in hospitals in Hong Kong, China, it remains undeveloped in primary care and little is known about the factors determining the development of such a model. The aims of the present study were to investigate the contribution of different models of nursing practice to the care provided in primary-care settings in Hong Kong, and to examine the determinants influencing the development of a model of ANP in such settings. A multiple case study design was selected using both qualitative and quantitative methods of data collection. Sampling methods reflected the population groups and stage of the case study. Sampling included a total population of 41 nurses from whom a secondary volunteer sample was drawn for face-to-face interviews. In each case study, a convenience sample of 70 patients were recruited, from whom 10 were selected purposively for a semi-structured telephone interview. An opportunistic sample of healthcare professionals was also selected. The within-case and cross-case analysis demonstrated four major determinants influencing the development of ANP: (1) current models of nursing practice; (2) the use of skills mix; (3) the perceived contribution of ANP to patient care; and (4) patients' expectations of care. The level of autonomy of individual nurses was considered particularly important. These determinants were used to develop a model of ANP for a primary-care setting. In conclusion, although the findings highlight the complexity determining the development and implementation of ANP in primary care, the proposed model suggests that definitions of advanced practice are appropriate to a range of practice models and cultural settings. However, the findings highlight the importance of assessing the effectiveness of such models in terms of cost and long-term patient outcomes.

Determinants of glomerular volume in different cortical zones of the human kidney

Enlarged glomerular size is a feature of focal segmental glomerulosclerosis, obesity-related glomerulopathy, diabetic nephropathy, and hypertension. The distribution of glomerular volumes within different cortical zones and glomerular volume alterations with age and obesity may contribute to understanding the evolution of these diseases. We analyzed the distributions of volumes of individual glomeruli in the superficial, middle, and juxtamedullary cortex of normal human kidneys using the disector/Cavalieri method. Volumes (V-glom) of 720 nonsclerotic glomeruli (30 per kidney, 10 per zone) were estimated in autopsy kidneys of 24 American men, 12 aged 20 to 30 yr and 12 aged 51 to 69 yr. Black and white individuals were represented equally. The range of individual V-glom within subjects varied from two- to eight-fold. There were no significant zonal differences in V-glom in the young or those with body surface area (BSA) <= 2.11 m(2). In contrast, superficial glomeruli in the older age group, in those with BSA > 2.11 m(2), and in white subjects were significantly larger than juxtamedullary glomeruli. Black subjects tended toward larger V-glom than white subjects, and this difference was significant and most marked in the juxtamedullary zone and independent of age, BSA, and glomerular number. There is a wide range in individual V-glom in adults. BSA, race, and age independently influence V-glom different zones of the renal cortex. These findings might reflect processes of aging and susceptibility factors to renal disease.

Determinants of stages of smoking uptake among secondary school students

With the uptake of cigarette smoking hypothesised to occur through a series of contemplation and action stages, we sought to investigate what factors are associated with the contemplation of smoking among secondary school students in Queensland, Australia. A series of four cross-sectional surveys were conducted among secondary schools in Queensland in 1993, 1996, 1999 and 2002. Respondents (n = 9993) were asked about the stages of smoking. Nearly half (43%) of secondary school students reported some contemplation of smoking. Increased levels of smoking contemplation were observed among females, earlier survey years, Junior level students, students with average or below average scholastic ability, those prepared to go out with a smoker, those with recent alcohol experience, those who bad influenced other students to smoke or had not discouraged other students smoking. The results of this study provide further information about the factors relevant to stages of smoking uptake among secondary school students and the influence that students may have on their peers. (c) 2005 Elsevier Ltd. All rights reserved.

Molecular determinants of ginkgolide binding in the glycine receptor pore

Ginkgolides are potent blockers of the glycine receptor Cl- channel (GlyR) pore. We sought to identify their binding sites by comparing the effects of ginkgolides A, B and C and bilobalide on alpha 1, alpha 2, alpha 1 beta and alpha 2 beta GlyRs. Bilobalide sensitivity was drastically reduced by incorporation of the beta subunit. In contrast, the sensitivities to ginkgolides B and C were enhanced by beta subunit expression. However, ginkgolide A sensitivity was increased in the alpha 2 beta GlyR relative to the alpha 2 GlyR but not in the alpha 1 beta GlyR relative to the alpha 1 GlyR. We hypothesised that the subunit-specific differences were mediated by residue differences at the second transmembrane domain 2' and 6' pore-lining positions. The increased ginkgolide A sensitivity of the alpha 2 beta GlyR was transferred to the alpha 1 beta GlyR by the G2'A (alpha 1 to alpha 2 subunit) substitution. In addition, the alpha 1 subunit T6'F mutation abolished inhibition by all ginkgolides. As the ginkgolides share closely related structures, their molecular interactions with pore-lining residues were amenable to mutant cycle analysis. This identified an interaction between the variable R2 position of the ginkgolides and the 2' residues of both alpha 1 and beta subunits. These findings provide strong evidence for ginkgolides binding at the 2' pore-lining position.

Onset of sheath extension and duration of lamina extension are major determinants of the response of maize lamina length to plant density

Background and Aims Plants regulate their architecture strongly in response to density, and there is evidence that this involves changes in the duration of leaf extension. This questions the approximation, central in crop models, that development follows a fixed thermal time schedule. The aim of this research is to investigate, using maize as a model, how the kinetics of extension of grass leaves change with density, and to propose directions for inclusion of this regulation in plant models. • Methods Periodic dissection of plants allowed the establishment of the kinetics of lamina and sheath extension for two contrasting sowing densities. The temperature of the growing zone was measured with thermocouples. Two-phase (exponential plus linear) models were fitted to the data, allowing analysis of the timing of the phase changes of extension, and the extension rate of sheaths and blades during both phases. • Key Results The duration of lamina extension dictated the variation in lamina length between treatments. The lower phytomers were longer at high density, with delayed onset of sheath extension allowing more time for the lamina to extend. In the upper phytomers—which were shorter at high density—the laminae had a lower relative extension rate (RER) in the exponential phase and delayed onset of linear extension, and less time available for extension since early sheath extension was not delayed. • Conclusions The relative timing of the onset of fast extension of the lamina with that of sheath development is the main determinant of the response of lamina length to density. Evidence is presented that the contrasting behaviour of lower and upper phytomers is related to differing regulation of sheath ontogeny before and after panicle initiation. A conceptual model is proposed to explain how the observed asynchrony between lamina and sheath development is regulated.

Solution structure and novel insights into the determinants of the receptor specificity of human relaxin-3

Relaxin- 3 is the most recently discovered member of the relaxin family of peptide hormones. In contrast to relaxin- 1 and - 2, whose main functions are associated with pregnancy, relaxin- 3 is involved in neuropeptide signaling in the brain. Here, we report the solution structure of human relaxin- 3, the first structure of a relaxin family member to be solved by NMR methods. Overall, relaxin- 3 adopts an insulin- like fold, but the structure differs crucially from the crystal structure of human relaxin- 2 near the B- chain terminus. In particular, the B- chain C terminus folds back, allowing Trp(B27) to interact with the hydrophobic-core. This interaction partly blocks the conserved RXXXRXXI motif identified as a determinant for the interaction with the relaxin receptor LGR7 and may account for the lower affinity of relaxin- 3 relative to relaxin for this receptor. This structural feature is likely important for the activation of its endogenous receptor, GPCR135.

Lifetime suicide risk in major depression: sex and age determinants

Background: Recent work has demonstrated that the lifetime suicide risk for patients with DSM IV Major Depression cannot mathematically approximate the accepted figure of 15%. Gender and age significantly affect both the prevalence of major depression and suicide risk, Methods: Gender and age stratified calculations were made on the entire population of the USA in 1994 using a mathematical algorithm. Sex specific corrections for under-reporting were incorporated into the design. Results: The lifetime suicide risks for men and women were 7% and 1%, respectively. The combined risk was 3.4%. The male:female ratio for suicide risk in major depression was 10:1 for youths under 25, and 5.6:1 for adults. Conclusions: Suicide in major depression is predominantly a male problem, although complacency towards female sufferers is to be avoided. Diagnosis of major depression is of limited help in predicting suicide risk compared to case specific factors. The male experience of depression that leads to suicide is often not identified as a legitimate medical complaint by either sufferers or professionals. Increasing help-accessing by males is a priority. Clinical implications: Patients with a history of hospitalisation; comorbidity, especially for substance abuse; and who are male, require greater vigilance for suicide risk. It may be that for males che threshold for diagnosing and treating major depression needs to be lowered. Limitations: This research is based on a mathematical algorithm to approximate a life-long longitudinal study that identifies community cases of depression. Our findings therefore rely on the validity of the statistics used. Extrapolation is limited to populations with an actual suicide rate of 17/100,000 or less and a lifetime prevalence of major depression of 17% or more. (C) 1999 Elsevier Science B.V. All rights reserved.

Determinants of visual 2-D echo assessment of left ventricular wall motion: Comparison with myocardial thickening on cardiac magnetic resonance imaging

Background: left ventricular wall motion on 2d echo (2de) is usually scored visually. we sought to examine the determinants of visually assessed wall motion scoring on 2de by comparison with myocardial thickening quantified on MRI. Methods: using a 16 segment model, we studied 287 segments in 30 patients aged 61+/ -11 years (6 female), with ischaemic LV dysfunction (defined by at least 2 segments dysfunctional on 2de). 2de was performed in 5 views and wall motion scores (WMS) assigned: 1 (normal) 103 segments, 2 (hypokinetic) 93 segments, 3 (akinetic) 87 segments. MRI was used to measure end systolic wall thickness (ESWT), end diastolic wall thickness (EDWT) and percentage systolic wall thickening (SWT%) in the plane of the 2de and to assess WMS in the same planes visually. No patient had a clinical ischemic event between the tests. Results: visual assessment of wall motion by 2de and MRI showed moderate agreement (kappa = 0.425). Resting 2de wall motion correlated significantly (p