An investigation into the detection of latent marks on the feathers and eggs of birds of prey

There are numerous enhancement techniques (physical and chemical) which have been developed for the successful visualisation of latent fingermarks. Nonetheless, problems arise when latent fingermarks require enhancement on difficult surfaces such as human skin, food stuffs, fabric and animals. The ability to develop latent fingermarks on the surface of bird of prey feathers and that of their eggs was investigated. Red and green magnetic fluorescent powders proved to be most suitable on the surface of bird of prey feathers whereas black magnetic powder was the most suitable technique on the eggs. These powders produced the highest quality of visible ridge-detailed developments over a controlled period of time

Environmental effects on magnetic fluorescent powder development of fingermarks on bird of prey feathers

A comparison study of the effects of environmental conditions on the development of latent fingermarks on raptor feathers using green magnetic fluorescent powder was undertaken using both sebaceous loaded and natural fingermark deposits. Sparrowhawk feathers were stored in indoor conditions for 60 days (Study 1), and buzzard feathers were left exposed to two different environmental conditions (hidden and visible) for 21 days (Study 2), with developments made at regular ageing periods. In Study 1, latent fingermarks were successfully developed (Grade 1–4) on the indoor feathers up to 60 days after deposition – 98.6% of the loaded deposits and 85.3% for natural deposits. Under outdoor conditions in Study 2, both loaded and natural deposits were affected by environmental exposure. Latent fingermarks were successfully developed up to 14 days after deposition on the outdoor feathers, with some occasional recovery after 21 days. The visible feathers recorded 34.7% (loaded) and 16.4% (natural) successful developments (Grade 1–4), whereas the hidden feathers recorded 46.7% (loaded) and 22.2% (natural) successful developments, suggesting that protection from the environment helps to preserve latent fingermarks on the surface of a feather. Environmental exposure accelerated the deterioration of ridge detail and the number of successful developments

Do Social Connections and Hope Matter in Predicting Early Adolescent Violence?

We tested relationships between social connections, hope, and violence among young adolescents from socially distressed urban neighborhoods, and examined whether relationships between adolescents' family and school connectedness and violence involvement were mediated by hopefulness. Data were from middle school students involved in the Lead Peace demonstration study. The sample (N = 164) was 51.8% female; 42% African American, 28% Asian, 13% Hispanic, and 17% mixed race or other race; average age was 12.1 years; 46% reported physical fighting in the past year. In multivariate models, parent‐family connectedness was protective against violence; school connectedness was marginally protective. Hopefulness was related to lower levels of violence. The relationship between school connectedness and violence was mediated by hopefulness; some evidence for mediation also existed in the family‐parent connectedness and violence relationship. Findings warrant continued exploration of hopefulness as an important protective factor against violence involvement, and as a mediator in relationships between social connections and violence involvement.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/116982/1/ajcp9387.pd

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

Is there an acute exercise-induced physiological/biochemical threshold which triggers increased speed of cognitive functioning? A meta-analytic investigation

Purpose: The purpose of this study was to examine, using meta-analytic measures, the evidence regarding the optimal exercise intensity at which improvements in speed of cognitive function are triggered. Specifically, it was hypothesized that the catecholamine, lactate, and ventilatory thresholds is the point at which significant improvements in speed of cognitive function are observed. Methods: We compared mean effect sizes for threshold studies and for those studies where exercise intensity was classed as moderate (40%–79% VO2max or equivalent) but in which the thresholds were not measured. Results: Random effects meta-analysis showed significant, moderate, mean effect sizes for studies at the threshold (g = 0.58, Z = 2.98, p < 0.003) and for those during moderate intensity exercise but in which the threshold was not measured (g = 0.54, Z = 5.01, p < 0.001). There was no significant difference between mean effect sizes, which suggests that the thresholds are unlikely to represent a trigger point. Conclusion: Moderate intensity exercise, even below the thresholds, can induce improved speed of cognition, possibly due to a combination of increased peripheral catecholamine concentrations inducing vagal/nucleus tractus solitarii pathway activation and central increases due to perceptions of stress

Does acute exercise affect the performance of whole-body, psychomotor skills in an inverted-U fashion?:a meta-analytic investigation

The primary purpose of this study was to examine, using meta-analytical measures, whether research into the performance of whole-body, psychomotor tasks following moderate and heavy exercise demonstrates an inverted-U effect. A secondary purpose was to compare the effects of acute exercise on tasks requiring static maintenance of posture versus dynamic, ballistic skills. Moderate intensity exercise was determined as being between 40% and 79% maximum power output (ẆMAX) or equivalent, while ≥ 80% ẆMAX was considered to be heavy. There was a significant difference (Zdiff = 4.29, p = 0.001, R2 = 0.42) between the mean effect size for moderate intensity exercise (g = 0.15) and that for heavy exercise size (g = − 0.86). These data suggest a catastrophe effect during heavy exercise. Mean effect size for static tasks (g = − 1.24) was significantly different (Zdiff = 3.24, p = 0.001, R2 = 0.90) to those for dynamic/ballistic tasks (g = − 0.30). The result for the static versus dynamic tasks moderating variables point to perception being more of an issue than peripheral fatigue for maintenance of static posture. The difference between this result and those found in meta-analyses examining the effects of acute exercise on cognition shows that, when perception and action are combined, the complexity of the interaction induces different effects to when cognition is detached from motor performance

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

Data-driven analytics to identify school absenteeism associated risk and protective factors for secondary school students

Chronic absenteeism (CA), defined as missing at least 15 school days/year, is recognized as a national problem in the U.S. with devastating long-term impacts for students. Previous studies have been guided by a mixture of diverse CA definitions and measurements which could potentially harm the applicability of findings. Despite the number of CA-associated factors identified, studies utilizing a unified theoretical system to a wide range of risk and protective factors has been scarce

Acute anxiety predicts components of the cold shock response on cold water immersion:toward an integrated psychophysiological model of acute cold water survival

Introduction: Drowning is a leading cause of accidental death. In cold-water, sudden skin cooling triggers the life-threatening cold shock response (CSR). The CSR comprises tachycardia, peripheral vasoconstriction, hypertension, inspiratory gasp, and hyperventilation with the hyperventilatory component inducing hypocapnia and increasing risk of aspirating water to the lungs. Some CSR components can be reduced by habituation (i.e., reduced response to stimulus of same magnitude) induced by 3–5 short cold-water immersions (CWI). However, high levels of acute anxiety, a plausible emotion on CWI: magnifies the CSR in unhabituated participants, reverses habituated components of the CSR and prevents/delays habituation when high levels of anxiety are experienced concurrent to immersions suggesting anxiety is integral to the CSR.Purpose: To examine the predictive relationship that prior ratings of acute anxiety have with the CSR. Secondly, to examine whether anxiety ratings correlated with components of the CSR during immersion before and after induction of habituation.Methods: Forty-eight unhabituated participants completed one (CON1) 7-min immersion in to cold water (15°C). Of that cohort, twenty-five completed four further CWIs that would ordinarily induce CSR habituation. They then completed two counter-balanced immersions where anxiety levels were increased (CWI-ANX) or were not manipulated (CON2). Acute anxiety and the cardiorespiratory responses (cardiac frequency [fc], respiratory frequency [fR], tidal volume [VT], minute ventilation [E]) were measured. Multiple regression was used to identify components of the CSR from the most life-threatening period of immersion (1st minute) predicted by the anxiety rating prior to immersion. Relationships between anxiety rating and CSR components during immersion were assessed by correlation.Results: Anxiety rating predicted the fc component of the CSR in unhabituated participants (CON1; p &lt; 0.05, r = 0.536, r2= 0.190). After habituation immersions (i.e., cohort 2), anxiety rating predicted the fR component of the CSR when anxiety levels were lowered (CON2; p &lt; 0.05, r = 0.566, r2= 0.320) but predicted the fc component of the CSR (p &lt; 0.05, r = 0.518, r2= 0.197) when anxiety was increased suggesting different drivers of the CSR when anxiety levels were manipulated; correlation data supported these relationships.Discussion: Acute anxiety is integral to the CSR before and after habituation. We offer a new integrated model including neuroanatomical, perceptual and attentional components of the CSR to explain these data