Familial and “On-the-Street” Risk Factors Associated with Alcohol Use among Homeless and Runaway Adolescents

Objective: This study investigated factors associated with alcohol use among homeless and runaway adolescents, using a risk amplification model.Method: Homeless and runaway adolescents (N = 536, 60% female) were recruited and interviewed by outreach workers directly on the streets, in shelters and in drop-in centers in four Midwestern states. The average age was 16 years; ages ranged from 12 to 22. Results: Parent alcohol problems were indirectly linked to adolescent drinking through familial abuse and its relationship to deviant peers, time on own and risky subsistence behaviors. Parent alcohol problems also predicted offspring alcohol use through parental rejection and its association with deviant peers and with risky subsistence behaviors. The strongest direct effects on alcohol use were hanging out with antisocial friends and participating in deviant behaviors in order to survive on the street. Conclusions: This study sheds light on the nature of alcohol use in a high-risk population. Family background and “on-the-street” (time on own) factors must be taken into consideration when treating alcohol misuse in street youth. The alternative is a vicious cycle whereby homeless youth may become homeless adults

Familial and “On-the-Street” Risk Factors Associated with Alcohol Use among Homeless and Runaway Adolescents

Objective: This study investigated factors associated with alcohol use among homeless and runaway adolescents, using a risk amplification model.Method: Homeless and runaway adolescents (N = 536, 60% female) were recruited and interviewed by outreach workers directly on the streets, in shelters and in drop-in centers in four Midwestern states. The average age was 16 years; ages ranged from 12 to 22. Results: Parent alcohol problems were indirectly linked to adolescent drinking through familial abuse and its relationship to deviant peers, time on own and risky subsistence behaviors. Parent alcohol problems also predicted offspring alcohol use through parental rejection and its association with deviant peers and with risky subsistence behaviors. The strongest direct effects on alcohol use were hanging out with antisocial friends and participating in deviant behaviors in order to survive on the street. Conclusions: This study sheds light on the nature of alcohol use in a high-risk population. Family background and “on-the-street” (time on own) factors must be taken into consideration when treating alcohol misuse in street youth. The alternative is a vicious cycle whereby homeless youth may become homeless adults

Axiomatic Characterization of the Mean Function on Trees

A mean of a sequence π = (x1, x2, . . . , xk) of elements of a finite metric space (X, d) is an element x for which is minimum. The function Mean whose domain is the set of all finite sequences on X and is defined by Mean(π) = { x | x is a mean of π } is called the mean function on X. In this paper the mean function on finite trees is characterized axiomatically

Laying the Foundation for Policy: Measuring Local Prevalence for Autism Spectrum Disorder

Claims have been made that families with children living with autism spectrum disorders (ASD) have been migrating to Alberta because of higher funding available for ASD supports compared to other provinces. The legitimacy of these claims, along with many others about the adequacy or inadequacy of funding for supporting persons living with ASD, has not been evaluated because we simply don’t know how many people in Alberta are living with ASD. Typically in Canada, ASD prevalence is reported in national figures, based on international estimates. Canadian prevalence estimates for ASD are needed. With no national surveillance system in place, national estimates are difficult to determine. In addition, such broad measurements are problematic as they may not adequately inform the service delivery needs for specific jurisdictions. A new study shows that 1,711, or 1 in 94, school age children in the Calgary region have an ASD diagnosis. As this number matches what is often reported for the national prevalence of ASD, it suggests that Alberta’s relatively higher ASD funding is not inducing in-migration of families seeking better support. The data also show that the prevalence is higher in elementary-grade children, with a diagnosis in one of every 86 children. In the senior grades, there are significantly fewer students with ASD diagnoses, specifically within the Calgary Board of Education. There is no evident reason for diagnoses to seemingly dematerialize in the older grades. These students could be dropping out or choosing home-schooling in greater numbers. Possibly there has been an increase in prevalence. These prevalence estimates help to inform the demand for special-needs services within the local school system. In addition, there is growing concern that upon graduation there is a “support cliff” resulting from a less systematized, less generous support system available for adults with neurodevelopmental disability. Families that need support for ASD face enough challenges; it is critical for policy-makers to be aware of the extent of the situation in their own jurisdiction so as to develop the right kinds of supports for these families

Creatine supplementation research fails to support the theoretical basis for an effect on cognition: Evidence from a systematic review

Creatine supplementation has been put forward as a possible aid to cognition, particularly for vegans, vegetarians, the elderly, sleep deprived and hypoxic individuals. However, previous narrative reviews have only provided limited support for these claims. This is despite the fact that research has shown that creatine supplementation can induce increased brain concentrations of creatine, albeit to a limited extent. We carried out a systematic review to examine the current state of affairs. The review supported claims that creatine supplementation can increases brain creatine content but also demonstrated somewhat equivocal results for effects on cognition. It does, however, provide evidence to suggest that more research is required with stressed populations, as supplementation does appear to significantly affect brain content. Issues with research design, especially supplementation regimens, need to be addressed. Future research must include measurements of creatine brain content

Cognitive performance is associated with cerebral oxygenation and peripheral oxygen saturation, but not plasma catecholamines, during graded normobaric hypoxia

What is the central question of this study? What are the mechanisms responsible for the decline in cognitive performance following exposure to acute normobaric hypoxia? What are the main findings and their importance? We found that 1) performance of a complex central executive task (n-back) was reduced FiO 0.12; 2) there was a strong correlation between performance of the n-back task and reductions in SpO and cerebral oxygenation; and 3) plasma adrenaline, noradrenaline, cortisol, and copeptin were not correlated with cognitive performance. It is well established that hypoxia impairs cognitive function; however, the physiological mechanisms responsible for these effects have received relatively little attention. This study examined the effects of graded reductions in fraction of inspired oxygen (FiO ) on oxygen saturation (SpO ), cerebral oxygenation, cardiorespiratory variables, activity of the sympathoadrenal system (adrenaline, noradrenaline) and hypothalamic-pituitary-adrenal axis (cortisol, copeptin), and cognitive performance. Twelve healthy males (mean [SD], age: 22 [4] yrs, height: 178 [5] cm, mass: 75 [9] kg, FEV /FVC ratio: 85 [5] %) completed a 4-task battery of cognitive tests to examine inhibition, selective attention (Eriksen Flanker), executive function (n-back) and simple and choice reaction time (Deary-Liewald). Tests were completed before and following 60 minutes of exposure to FiO 0.2093, 0.17, 0.145, and 0.12. Following 60 minutes of exposure response accuracy in the n-back task was significantly reduced in FiO 0.12 compared to baseline (82 [9] vs. 93 [5] %; p < 0.001) and compared to all other conditions at the same time point (FiO 0.2093: 92 [3] %, FiO 0.17: 91 [6] %, FiO 0.145: 85 [10] %, FiO 12: 82 [9] %; all p < 0.05). The performance of the other tasks was maintained. Δ accuracy and Δ reaction time of the n-back task was correlated with both Δ SpO (r (9) = 0.66; p < 0.001 and r (9) = - 0.36; p = 0.037 respectively) and Δ cerebral oxygenation (r (7) = 0.55; p < 0.001 and r (7) = - 0.38; p = 0.045 respectively). Plasma adrenaline, noradrenaline, cortisol and copeptin were not significantly elevated in any condition or correlated with any of the tests of cognitive performance. These findings suggest that reductions in peripheral oxygen saturation and cerebral oxygenation, and not increased activity of the sympathoadrenal system and hypothalamic-pituitary-adrenal axis, as previously speculated, are responsible for a decrease in cognitive performance during normobaric hypoxia

Effects of beta-alanine supplementation on brain homocarnosine/carnosine signal and cognitive function: an exploratory study

Objectives: Two independent studies were conducted to examine the effects of 28 d of beta-alanine supplementation at 6.4 g d-1 on brain homocarnosine/carnosine signal in omnivores and vegetarians (Study 1) and on cognitive function before and after exercise in trained cyclists (Study 2). Methods: In Study 1, seven healthy vegetarians (3 women and 4 men) and seven age- and sex-matched omnivores undertook a brain 1H-MRS exam at baseline and after beta-alanine supplementation. In study 2, nineteen trained male cyclists completed four 20-Km cycling time trials (two pre supplementation and two post supplementation), with a battery of cognitive function tests (Stroop test, Sternberg paradigm, Rapid Visual Information Processing task) being performed before and after exercise on each occasion. Results: In Study 1, there were no within-group effects of beta-alanine supplementation on brain homocarnosine/carnosine signal in either vegetarians (p = 0.99) or omnivores (p = 0.27); nor was there any effect when data from both groups were pooled (p = 0.19). Similarly, there was no group by time interaction for brain homocarnosine/carnosine signal (p = 0.27). In study 2, exercise improved cognitive function across all tests (P0.05) of beta-alanine supplementation on response times or accuracy for the Stroop test, Sternberg paradigm or RVIP task at rest or after exercise. Conclusion: 28 d of beta-alanine supplementation at 6.4g d-1 appeared not to influence brain homocarnosine/ carnosine signal in either omnivores or vegetarians; nor did it influence cognitive function before or after exercise in trained cyclists

Skill execution and sleep deprivation: effects of acute caffeine or creatine supplementation - a randomized placebo-controlled trial

<p>Abstract</p> <p>Background</p> <p>We investigated the effects of sleep deprivation with or without acute supplementation of caffeine or creatine on the execution of a repeated rugby passing skill.</p> <p>Method</p> <p>Ten elite rugby players completed 10 trials on a simple rugby passing skill test (20 repeats per trial), following a period of familiarisation. The players had between 7-9 h sleep on 5 of these trials and between 3-5 h sleep (deprivation) on the other 5. At a time of 1.5 h before each trial, they undertook administration of either: placebo tablets, 50 or 100 mg/kg creatine, 1 or 5 mg/kg caffeine. Saliva was collected before each trial and assayed for salivary free cortisol and testosterone.</p> <p>Results</p> <p>Sleep deprivation with placebo application resulted in a significant fall in skill performance accuracy on both the dominant and non-dominant passing sides (p < 0.001). No fall in skill performance was seen with caffeine doses of 1 or 5 mg/kg, and the two doses were not significantly different in effect. Similarly, no deficit was seen with creatine administration at 50 or 100 mg/kg and the performance effects were not significantly different. Salivary testosterone was not affected by sleep deprivation, but trended higher with the 100 mg/kg creatine dose, compared to the placebo treatment (p = 0.067). Salivary cortisol was elevated (p = 0.001) with the 5 mg/kg dose of caffeine (vs. placebo).</p> <p>Conclusion</p> <p>Acute sleep deprivation affects performance of a simple repeat skill in elite athletes and this was ameliorated by a single dose of either caffeine or creatine. Acute creatine use may help to alleviate decrements in skill performance in situations of sleep deprivation, such as transmeridian travel, and caffeine at low doses appears as efficacious as higher doses, at alleviating sleep deprivation deficits in athletes with a history of low caffeine use. Both options are without the side effects of higher dose caffeine use.</p