Observations of concentric ring clouds west of Australia

Some interesting cloud formations off the west coast of Western Australia on NOAA AVHRR and GMS-5 images are described. The cloud structures shown here are rare and may be related to the 'Morning Glory' phenomenon. This Letter provides an observational study of these clouds which we are calling 'Concentric Ring Clouds'. A plausible mechanism for their generation is presented in terms of anomalous latent heat release, thunderstorm downdraught and outflow causing wave propagation in a low-level wave guide.     

Adolescent smoking trajectories and nicotine dependence.

The present study correlates empirically constructed prospective adolescent smoking trajectories with indicators of nicotine dependence assessed in adolescence and in adulthood. Excluding individuals who reported no smoking during repeat assessment (nonadopters), we identified five smoking trajectory groups: experimenters (n=116, 48.5%), late increasers (n=39, 16.3%), early increasers (n=37, 15.5%), quitters (n=22, 9.2%), and persistent smokers (n=25, 10.5%). Higher frequency of nicotine dependence symptoms in adolescence occurred in the quitters and persistent smokers groups, who smoked at higher levels relative to the experimenters, late increasers, and early increasers groups, who reported a similar frequency of nicotine dependence symptoms and smoked at low levels. Lifetime nicotine dependence was assessed in adulthood in lifetime daily smokers using the Fagerstr?m Test for Nicotine Dependence (FTND) and the Nicotine Dependence Scale (NDS). Lifetime FTND levels were similar across trajectory groups. Relative to experimenters, all remaining smoking trajectory groups had higher NDS levels that were similar to one another. These results suggest that higher levels of adolescent nicotine dependence were associated with heavier smoking trajectory groups, and that regardless of trajectory group membership, smoking more than a few cigarettes per week throughout adolescence resulted in similar levels of lifetime nicotine dependence as measured by the FTND and NDS.     

The influence of peers on young adult substance use.

Data collected from 294 young adults, ages 19 to 25, and both a same- and an opposite-gender best friend or mate across 3 annual assessments were analyzed to examine the similarity to and influence of the peer on the young adult's substance use. The authors found similarity across time between both peers and the young adult in cigarette use, alcohol use, binge drinking, and, in most cases, marijuana use. In prospective analyses, peer use predicted young adult cigarette use, binge drinking, and problem use by the young adults. Results were generally consistent across gender and for both same- and opposite-gender peers. Findings emphasize peer influence contribution to young adult substance use and suggest the design of interventions that involve both young adults and their peers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of continuous subcutaneous insulin infusion with lispro on hepatic responsiveness to glucagon in type 1 diabetes

OBJECTIVE: People with type 1 diabetes frequently develop a blunted counterregulatory hormone response to hypoglycemia coupled with a decreased hepatic response to glucagon, and consequently, they have an increased risk of severe hypoglycemia. We have evaluated the effect of insulin lispro (Humalog) versus regular human insulin (Humulin R) on the hepatic glucose production (HGP) response to glucagon in type 1 diabetic patients on intensive insulin therapy with continuous subcutaneous insulin infusion (CSII). RESEARCH DESIGN AND METHODS: Ten subjects on CSII were treated for 3 months with lispro and 3 months with regular insulin in a double-blind randomized crossover study After 3 months of treatment with each insulin, hepatic sensitivity to glucagon was measured in each subject. The test consisted of a 4-h simultaneous infusion of somatostatin (450 microg/h) to suppress endogenous glucagon, regular insulin (0.15 mU x kg(-1) x min(-1)), glucose at a variable rate to maintain plasma glucose near 5 mmol/l, and D-[6,6-2H2]glucose to measure HGP During the last 2 h, glucagon was infused at 1.5 ng x kg(-1) x min(-1). Eight nondiabetic people served as control subjects. RESULTS: During the glucagon infusion period, free plasma insulin levels in the diabetic subjects were 71.7+/-1.6 vs. 74.8+/-0.5 pmol/l after lispro and regular insulin treatment, with plasma glucagon levels of 88.3+/-1.8 and 83.7+/-1.5 ng/l for insulin:glucagon ratios of 2.8 and 3.0. respectively (NS). However, plasma glucose increased to 9.2+/-1.1 mmo/l after lispro insulin compared with 7.1+/-0.9 mmol/l after regular insulin (P < 0.01), and the rise in HGP was 5.7 +/-2.8 micromol x kg(-1) x min(-1) after lispro insulin versus 3.1+/-2.9 micromol x kg(-1) x min(-1) after regular insulin treatment (P=0.02). In the control subjects, HGP increased by 10.7+/-4.2 micromol x kg(-1) x min(-1) under glucagon infusion. CONCLUSIONS: Insulin lispro treatment by CSII was associated with a heightened response in HGP to glucagon compared with regular human insulin. This suggests that insulin lispro increases the sensitivity of the liver to glucagon and could potentially decrease the risk of severe hypoglycemia.     

The development of children's intentions to use alcohol: Direct and indirect effects of parent alcohol use and parenting behaviors.

The purpose of this study was to explore the effect of parent alcohol use and parenting behavior on the development of children's intentions to use alcohol in Grades 1 through 8. The authors hypothesized that the effect of parent alcohol use on children's intention to use alcohol would be mediated through parenting behavior, specifically monitoring/supervision, positive parenting, and inconsistent discipline. Using cohort-sequential latent growth modeling (LGM), the authors tested 3 models examining the effect of the development of parent alcohol use on the development of children's intentions to use alcohol, as mediated by the development of each of the 3 parenting behaviors. Multiple group analyses were used to explore gender differences. The effect of growth in parent alcohol use on growth in children's intentions was mediated only by parent monitoring/supervision and was significant only for girls. The effect of inconsistent discipline was directly related to growth in intentions for both boys and girls. Although parent alcohol use was related to less positive parenting, positive parenting was unrelated to children's intentions to use alcohol. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Adolescents' relationships with their mothers and fathers: Associations with depressive disorder and subdiagnostic symptomatology.

Family relationships across 3 groups of adolescents were compared: (a) those with unipolar depressive disorders (n=82); (b) those with subdiagnostic depressive symptoms (n=78); and (c) those without emotional or behavioral difficulties (n=83). Results based on multisource, multimethod constructs indicated that depressed adolescents, as well as those with subdiagnostic symptomatology, experience less supportive and more conflictual relationships with each of their parents than do healthy adolescents. These findings are notable in demonstrating that adverse father-adolescent relationships are associated with depressive symptomatology in much the same way as mother-adolescent relationships. As well, the findings add to the emerging evidence that adolescents with subdiagnostic symptoms experience difficulties in social relationships similar to those experienced by adolescents with depressive disorder. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Causes of delayed outbreak responses and their impacts on epidemic spread

Livestock diseases have devastating consequences economically, socially and politically across the globe. In certain systems, pathogens remain viable after host death, which enables residual transmissions from infected carcasses. Rapid culling and carcass disposal are well-established strategies for stamping out an outbreak and limiting its impact; however, wait-times for these procedures, i.e. response delays, are typically farm-specific and time-varying due to logistical constraints. Failing to incorporate variable response delays in epidemiological models may understate outbreak projections and mislead management decisions. We revisited the 2001 foot-and-mouth epidemic in the United Kingdom and sought to understand how misrepresented response delays can influence model predictions. Survival analysis identified farm size and control demand as key factors that impeded timely culling and disposal activities on individual farms. Using these factors in the context of an existing policy to predict local variation in response times significantly affected predictions at the national scale. Models that assumed fixed, timely responses grossly underestimated epidemic severity and its long-term consequences. As a result, this study demonstrates how general inclusion of response dynamics and recognition of partial controllability of interventions can help inform management priorities during epidemics of livestock diseases.     

Insights into mucosal innate responses to Escherichia coli O157 : H7 colonization of cattle by mathematical modelling of excretion dynamics

Mathematical model-based statistical inference applied to within-host dynamics of infectious diseases can help dissect complex interactions between hosts and microbes. This work has applied advances in model-based inference to understand colonization of cattle by enterohaemorrhagic Escherichia coli O157 : H7 at the terminal rectum. A mathematical model was developed based on niche replication and transition rates at this site. A nested-model comparison, applied to excretion curves from 25 calves, was used to reduce complexity while maintaining integrity. We conclude that, 5–9 days post inoculation, the innate immune response negates bacterial replication on the epithelium and either reduces attachment to or increases detachment from the epithelium of the terminal rectum. Thus, we provide a broadly applicable model that gives novel insights into bacterial replication rates in vivo and the timing and impact of host responses.     

Alterations in non-insulin-mediated glucose uptake in the elderly patient with diabetes

It is increasingly recognized that alterations in non-insulin-mediated glucose uptake (NIMGU) play an important pathogenic role in disorders of carbohydrate metabolism. This study was conducted to determine whether NIMGU is impaired in elderly patients with type 2 diabetes. Healthy elderly control subjects (n = 19, age 76 +/- 1 years, BMI 26.8 +/- 1.1 kg/m2) and elderly patients with type 2 diabetes (n = 19, age 76 +/- 2 years, BMI 27.5 +/- 0.9 kg/m2) underwent a 240-min glucose clamp study. Octreotide was infused to suppress endogenous insulin release, and tritiated glucose methodology was used to measure glucose uptake and disposal rates. For the first 180 min, glucose was kept at fasting levels. From 180 to 240 min, glucose was increased to 11 mmol/l. At fasting glucose levels, glucose uptake was similar in both groups. However, glucose clearance was reduced in patients with diabetes (control 1.68 +/- 0.05 ml x kg(-1) x min(-1); diabetes 1.34 +/- 0.07 ml x kg(-1) x min(-1), P < 0.0001). During hyperglycemia, glucose uptake was reduced in patients with diabetes (control 3.16 +/- 0.09 mg x kg(-1) x min(-1); diabetes 2.57 +/- 0.11 mg x kg(-1) x min(-1), P < 0.0001). Peripheral glucose effectiveness (SG) was less in patients with diabetes (control 1.28 +/- 0.04 ml x kg(-1) x min(-1); diabetes 0.94 +/- 0.08 ml x kg(-1) x min(-1), P < 0.0001). Hepatic glucose output and hepatic SG were not different between groups. We conclude that the effect of glucose on glucose uptake is impaired in elderly patients with type 2 diabetes, a finding that may have therapeutic implications for this patient population.