A Qualitative Study of How Adolescents’ Use of Coping Strategies and Support Varies in Line With Their Experiences of Adversity

BACKGROUND: Adolescence is associated with a rise in the incidence of mental health issues. Thus, the factors, processes, and contexts that protect and promote positive mental health in adolescence are of key interest to policymakers. OBJECTIVE: Our aim was twofold: First, to explore the coping strategies and sources of support that adolescents identify as protective (or not) in the face of difficulty over a three-year period; second, to examine how and why this may vary in line with the levels of adversity that they report experiencing in life. METHODS: Participants were attending schools in England implementing a mental health prevention programme called HeadStart. 93 semi-structured interviews were conducted with 31 adolescents (age 11–12 at the outset of the study; 58% female) once per year over three years. The interviews were analysed using thematic analysis. RESULTS: Six coping strategy themes (e.g., ‘Disengaging from problems’) and five support themes (e.g., ‘Parents as a source of comfort and advice’) were derived from the interviews. The types, quality, and consistency of reported coping strategies and support varied in line with whether adolescents were experiencing higher or lower levels of adversity in life over time, and according to the resources that they had available within their physical and social contexts. CONCLUSIONS: Our findings underscore the importance for mental health prevention programmes of bolstering both individual-level coping strategies and the resources available within adolescents’ environments to help them to manage adversity

Palaeobiology, ecology, and distribution of stromatoporoid faunas in biostromes of the mid-Ludlow of Gotland

Six well exposed mid−Ludlow stromatoporoid−dominated reef biostromes in four localities from the Hemse Group in southeastern Gotland, Sweden comprise a stromatoporoid assemblage dominated by four species; Clathrodictyon mohicanum, “Stromatopora” bekkeri, Plectostroma scaniense, and Lophiostroma schmidtii. All biostromes investigated in this area (of approximately 30 km2) are interpreted to belong to a single faunal assemblage forming a dense accumulation of fossils that is probably the best exposed stromatoporoid−rich deposit of the Silurian. The results from this comprehensive study strengthen earlier interpretations of a combination of genetic and environmental control on growth−forms of the stromatoporoids. Growth styles are similar for stromatoporoids in all six biostromes. Differences in biostrome fabric are due to variations in the degree of disturbance by storms. The uniformity of facies and the widespread low−diversity fauna support the view that palaeoenvironmental conditions were similar across the area where these biostromes crop out, and promoted the extraordinary growth of stromatoporoids in this shallow shelf area

Effects of Diverting Activities on Recovery from Repeated Maximum Voluntary Contractions

Previous investigations have demonstrated that diverting activities (e.g., contralateral exercise and pinching one’s fingers together) can minimize the severity of muscle fatigue that occurs during exercise. In addition to their ability to resist fatigue during exercise, diverting activities may help subjects recover between work bouts. The purpose of this study was to examine the effects of mental and physical diverting activities on recovery from fatiguing isometric muscle actions. On three separate occasions, twelve men (mean ± SD age = 22 ± 1 years) and nine women (age = 22 ± 2 years) performed ten repeated, ten-second isometric maximum voluntary contractions (MVCs) of the dominant leg extensors with ten seconds of rest between each attempt (i.e., ten seconds “on,” ten seconds “off”). Following this fatiguing protocol, the subjects performed math problems (mental diverting activity), five, 20-second isometric muscle actions with the non-dominant leg extensors at a force corresponding to 50% MVC (physical diverting activity), or rested quietly (control). Immediately following this intervention period, the subjects performed a final three-second MVC, which assessed how well the leg extensors recovered from the fatiguing protocol (Post-Recovery MVC). These three data collection trials were randomly performed, and separated by at least 48 hours of rest. A two-way (time [Pre-Fatigue MVC, MVC #1-10, Post-Fatigue MVC, Post-Recovery MVC] × intervention [math problems, contralateral, and control]) repeated measures analysis of variance was used to examine the isometric force data. The mean ± SD Post-Recovery MVC values were as follows: mental diverting activities =765 ± 210 N; physical diverting activities = 797 ± 235 N; control = 790 ± 258 N. There was no significant time × intervention interaction (partial eta squared = .072), no main effect for intervention, but there was a main effect for time. The marginal mean pairwise comparisons indicated: Pre-Fatigue MVC \u3e MVC#1 – Post-Fatigue MVC; MVC #4 – Post-Fatigue MVC \u3c Post-Recovery MVC. In contrast to the results from previous studies, our results indicated that performing mental and physical diverting activities did not help the subjects recover from fatigue

Relationship Between One Repetition Maximum Strength and Peak Power Output for the Free-Weight Bench Press Exercise

Strength and conditioning coaches are often interested in improving power output in their athletes. As many coaches are aware that power is the product of force and velocity, an emphasis is often placed on training with loads that correspond to peak mechanical power output (e.g., 30-50% of the one repetition maximum [1RM]). The purpose of this study was to examine the relationship between 1RM strength and peak power output during the free-weight bench press exercise. Twenty-one healthy, recreationally resistance-trained men (mean ± SD age = 24 ± 3 years; body mass = 90.5 ± 14.6 kg; 1RM bench press = 125.4 ± 18.4 kg) volunteered for this investigation. A minimum of 48 hours following a maximal strength testing and familiarization session, the subjects performed a single repetition of the bench press using 50% of the 1RM. For each repetition, the subjects were instructed press the weight explosively throughout the concentric portion of the range of motion. A Tendo Weightlifting Analyzer was used to assess peak power output for each repetition. A linear regression analysis was used to examine the relationship between 1RM strength and peak power output. The results indicated that the coefficient of determination (R2) was 0.697, suggesting that 1RM strength explained roughly 70% of the variance in peak power output. The linear slope coefficient was 5.94 W/kg, and the y-intercept was 110.2 W. These findings demonstrated that 1RM strength and peak power output were highly correlated. Although explosive training with light loads is often stressed in strength and conditioning programs, for the free-weight bench press exercise, a relatively small degree of variance in peak power output can be explained by factors other than 1RM strength

Hepatic progenitor cells from adult human livers for cell transplantation.

Objective: Liver regeneration is mainly based on cellular self-renewal including progenitor cells. Efforts have been made to harness this potential for cell transplantation, but shortage of hepatocytes and premature differentiated progenitor cells from extra-hepatic organs are limiting factors. Histological studies implied that resident cells in adult liver can proliferate, have bipotential character and may be a suitable source for cell transplantation. Methods: Particular cell populations were isolated after adequate tissue dissociation. Single cell suspensions were purified by Thy-1 positivity selection, characterised in vitro and transplanted in immunodeficient Pfp/Rag2 mice. Results: Thy-1+ cells that are mainly found in the portal tract and the surrounding parenchyma, were isolated from surgical liver tissue with high yields from specimens with histological signs of regeneration. Thy-1+ cell populations were positive for progenitor (CD34, c-kit, CK14, M2PK, OV6), biliary (CK19) and hepatic (HepPar1) markers revealing their progenitor as well as hepatic and biliary nature. The potential of Thy-1+ cells for differentiation in vitro was demonstrated by increased mRNA and protein expression for hepatic (CK18, HepPar1) and biliary (CK7) markers during culture while progenitor markers CK14, chromogranin A and nestin were reduced. After transplantation of Thy-1+ cells into livers of immunodeficient mice, engraftment was predominantly seen in the periportal portion of the liver lobule. Analysis of in situ material revealed that transplanted cells express human hepatic markers HepPar1 and albumin, indicating functional engraftment. Conclusion: Bipotential progenitor cells from human adult livers can be isolated using Thy-1 and might be a potential candidate for cell treatment in liver diseases

Trade-Offs in Relative Limb Length among Peruvian Children: Extending the Thrifty Phenotype Hypothesis to Limb Proportions

Background and Methods Both the concept of ‘brain-sparing’ growth and associations between relative lower limb length, childhood environment and adult disease risk are well established. Furthermore, tibia length is suggested to be particularly plastic under conditions of environmental stress. The mechanisms responsible are uncertain, but three hypotheses may be relevant. The ‘thrifty phenotype’ assumes that some components of growth are selectively sacrificed to preserve more critical outcomes, like the brain. The ‘distal blood flow’ hypothesis assumes that blood nutrients decline with distance from the heart, and hence may affect limbs in relation to basic body geometry. Temperature adaptation predicts a gradient of decreased size along the limbs reflecting decreasing tissue temperature/blood flow. We examined these questions by comparing the size of body segments among Peruvian children born and raised in differentially stressful environments. In a cross-sectional sample of children aged 6 months to 14 years (n = 447) we measured head circumference, head-trunk height, total upper and lower limb lengths, and zeugopod (ulna and tibia) and autopod (hand and foot) lengths. Results Highland children (exposed to greater stress) had significantly shorter limbs and zeugopod and autopod elements than lowland children, while differences in head-trunk height were smaller. Zeugopod elements appeared most sensitive to environmental conditions, as they were relatively shorter among highland children than their respective autopod elements. Discussion The results suggest that functional traits (hand, foot, and head) may be partially protected at the expense of the tibia and ulna. The results do not fit the predictions of the distal blood flow and temperature adaptation models as explanations for relative limb segment growth under stress conditions. Rather, our data support the extension of the thrifty phenotype hypothesis to limb growth, and suggest that certain elements of limb growth may be sacrificed under tough conditions to buffer more functional traits

Creatine Kinase, Lactate Dehydrogenase, and Myoglobin Responses Following Repeated Wingate Anaerobic Tests Versus Barbell Back Squats: a Pilot Study

The results from many previous studies have demonstrated that muscle damage and delayed onset muscle soreness are due primarily to high force, eccentric muscle actions. However, the majority of investigators have examined these responses following single-joint, isokinetic assessments. The purpose of this study was to examine creatine kinase (CK), lactate dehydrogenase (LDH), and myoglobin responses following repeated Wingate anaerobic tests versus multiple sets of the barbell back squat exercise. Six recreationally resistance-trained men (mean ± SD age = 23 ± 2 years, body mass = 88.0 ± 17.8 kg, one repetition-maximum [1RM] back squat = 150.0 ± 28.3 kg) volunteered for this investigation, and visited the laboratory on five separate occasions. For the back squat protocol, the subjects performed six sets until volitional exhaustion using 75% of the 1RM with two minutes of rest between each set. For all repetitions, the subjects squatted to the parallel position. For the Wingate protocol, the subjects performed three tests with a 10 minute recovery period between each attempt. The order of these two protocols was randomized, and all testing for the study occurred at the same time of day. The subjects were required to refrain from vigorous physical activity during the study. Immediately prior to and 24 hours following each protocol, the subjects provided a venous blood sample from a superficial forearm vein. At the conclusion of the study, all samples were processed for CK, LDH, and myoglobin analyses. Three separate two-way (time [Pre versus Post] × protocol [squats versus Wingate anaerobic tests]) repeated measures analyses of variance were used to examine the CK, LDH, and myoglobin data. For CK, there was a significant time × protocol interaction (partial eta squared = .761). Follow-up paired samples t-tests indicated that the mean CK values increased following the squat protocol (Pre mean ± SD = 233.2 ± 97.4; Post = 457.0 ± 119.9 IU/L), but not the Wingate anaerobic tests (Pre = 218.5 ± 103.9; Post = 231.7 ± 65.3 IU/L). There was no mean difference between the protocols for both LDH and myoglobin. The primary finding from this pilot study was that performing six sets of barbell back squats using 75% of the 1RM significantly increased blood CK levels in resistance-trained men. Although additional studies with larger sample sizes are needed to confirm our findings, CK appears to be a more sensitive measure of muscle damage than both LDH and myoglobin