72 research outputs found
Effects of increasing cold exposure on the oxygen uptake of walking unloaded and loaded.
Introduction: Cold exposure and load carriage is an understudied area. Most research shows that VO2max is generally unaffected by cold exposure, however the majority of research suggests that sub-maximal O2 consumption increases for a given workload [1]. This pilot study assessed the effects of cold on load carriage.
Methods: 4 male participants (age: 21.8 ± 3.4 years, height: 182.5 ±5.0 cm, weight: 77.8 ± 13.5 kg) completed a walking protocol of ~1 hour in a range of different ambient temperatures within an environmental chamber (20 °C, 10 °C, 5 °C, 0 °C, -5 °C and -10 °C). Humidity was controlled at ~50% while altitude was 0 m (20.95% FiO2). Participants wore shorts and t-shirt for all trials. The protocol included a 15 minute rest period, unloaded walking at 4 km.hr-1 for 4 minutes at 0% and 10% gradient. The same workloads were repeated loaded (18 kg) after a 5 minute rest. Heart rate returned to resting levels before each exercise section to ensure prior activity did not influence findings. Unloaded walking was then repeated. Expired air was collected and analysed using a Cortex 3B Metalyzer (Germany). Statistical analysis was performed using SPSS version 22, with significance denoted by p < 0.05.
Results: Table Table1 shows a significant increase in VO2 with load (p = 0.019). At all workloads, significant increases in VO2 were associated with decreasing temperature (p = 0.048). ΔVO2 values suggest that the effect of loading was consistent, regardless of ambient temperature (p = 0.997). When comparing the first unloaded exercise bout with the second, VO2 for 20 °C, 10 °C and 5 °C was similar, whereas at 0 °C and below, VO2 was higher in the second unloaded bout, but this interaction was not significant (p = 0.158)
Plant Macrofossils Associated with an Early Holocene Beaver Dam in Interior Alaska
Dynamic climate changes and expansion of new biomes characterize the late Pleistocene–early Holocene of eastern Beringia. Analysis of plant macrofossils from an early Holocene (ca. 9300 14C yrs BP) beaver dam in central Alaska provides insight into the local environment and vegetation. The plant macrofossil assemblage comprises remains of trees and shrubs, graminoids, and forbs, including Betula sp., Carex sp., Rubus sp., Eleocharis sp., Scirpus sp., Potamogeton sp., Najas flexilis and Typha latifolia, indicative of standing water of a beaver pond. Bryophytes from the beaver dam include Warnstorfia spp. and Drepanocladus aduncus, suggesting shallow, stagnant, or slow-moving water. The presence of Najas flexilis, Typha latifolia, and modern beaver (Castor canadensis) suggest that central Alaska had a warmer climate during the early Holocene.Changements climatiques dynamiques et expansion de nouveaux biomes caractérisent la période du Pléistocène supérieur et de l’Holocène inférieur de la Béringie de l’Est. L’analyse des macrofossiles de plantes provenant d’une digue de castor du centre de l’Alaska datant de l’Holocène inférieur (env. 9300 14C années BP) donne des indices sur l’environnement et la végétation de la région. L’assemblage de macrofossiles de plantes est composé d’arbres et d’arbustes, de graminoïdes et d’herbes non graminéennes, dont Betula sp., Carex sp., Rubus sp., Eleocharis sp., Scirpus sp., Potamogeton sp., Najas flexilis et Typha latifolia, ce qui signale la présence d’eau stagnante dans un étang de castor. Parmi les bryophytes de la digue de castor, notons Warnstorfia spp. et Drepanocladus aduncus, ce qui laisse supposer la présence d’eau peu profonde stagnante ou se déplaçant lentement. Par ailleurs, la présence de Najas flexilis, Typha latifolia et du castor contemporain (Castor canadensis) laissent croire que le climat du centre de l’Alaska était plus chaud pendant l’Holocène inférieur
Delivering a Parenting Program in South Africa: The Impact of Implementation on Outcomes
Objectives: Previous studies of parenting programs suggest that facilitator fidelity, participant attendance and engagement often influence treatment outcomes. While the number of parenting program evaluations has been growing in low- and middle-income countries, little is known about the implementation processes and their impact on participant outcomes in these settings.
Methods: This study was nested within a cluster-randomised trial of a parenting program in South Africa. The paper aims to, first, describe the implementation of the intervention over 14 weeks. Second, using longitudinal multilevel analyses, the paper examines the impact of variation in observer-rated fidelity, attendance, and engagement on participant outcomes – parenting and maltreatment reported by caregivers and adolescents aged 10-18 (N=270 pairs), 14 outcome constructs.
Results: Fidelity, attendance and participant engagement rates were similar to those reported in high-income country studies. However, the participation and implementation characteristics did not predict participant outcomes. This may be due to limited variation in dosage as home visits were comprehensively provided when participants could not attend group sessions, and fidelity was monitored by the implementers and researchers. One statistically significant predictor after the multiple testing correction was higher fidelity predicting an increase in adolescent-reported maltreatment at follow-up, possibly due to an increase in reporting (incidence rate ratio 1.33, 95% CI [1.19, 1.49], p<0.01).
Conclusions: Our study confirms that a high quality of implementation can be achieved in a low-resource context. Suggestions for future research on parenting programs include examining therapeutic alliance alongside program fidelity and facilitator skill as well as systematically recording program adaptations.Cambridge Commonwealth, European & International Trust, research fellowship awarded by Global TIES for Children at New York University and funded by a grant from the Hewlett Foundation, Smuts Memorial Fund, managed by the University of Cambridge in memory of Jan Christiaan Smuts, and St John’s College, Cambridge. The European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013, grant agreement 313421), UNICEF Innocenti Office of Research, the Leverhulme Trust (grant number PLP-2014-095), the University of Oxford’s ESRC Impact Acceleration Account (K1311-KEA-004 & 1602-KEA-189), and the John Fell Fund (103/757)
Vascular plant, bryophyte, and lichen biodiversity of Agguttinni Territorial Park, Baffin Island, Nunavut, Canada: an annotated species checklist of a new Arctic protected area
Agguttinni Territorial Park is a large, newly established park on the east-central coast of Baffin Island in Nunavut, Canada. Previous knowledge of the plant and lichen biodiversity was limited and based mostly on collections made during the 1950 Baffin Island Expedition. We conducted a &#64258;oristic inventory of the park in 2021 and re-examined previous collections. We recorded 141 species of vascular plants belonging to 25 families, 69 species of bryophytes in 27 families, and 93 species of lichens in 23 families. Most of the vascular plant and bryophyte species are new records for the park area, and some vascular plants, bryophytes, and lichens are newly reported for Baffin Island, Nunavut, or the Canadian Arctic or represent signi&#64257;cant range extensions. Vascular plant species diversity varied greatly among localities, with inland valleys at the heads of &#64257;ords showing highest diversity and interior rocky barrens showing the lowest
Power to participants: methodological and ethical reflections from a decade of adolescent advisory groups in South Africa
Whilst the HIV response has made significant progress in increasing representation of adults affected by HIV, the meaningful inclusion of children and adolescents has lagged. But this may be a pivotal moment of change. We report on a decade of conducting adolescent advisory groups in South Africa, to reflect on youth advisory processes. Data was collected from 2008 to 2018 from adolescent advisors (n = 60) and researchers (n = 25), and included feedback sessions, social media, anonymous “post-boxes” and interviews. Findings include the value of adolescent involvement in multiple stages of research co-creation and engagement in policy processes, the need for a safe environment and supporting adolescents living in extreme vulnerability. We also discuss the reconfiguring of power and personal relationships, and logistical and financial needs of adolescent advisory groups. Findings suggest that adolescent co-creation of research is feasible, even with very vulnerable adolescents, although ethical considerations need to be carefully addressed. Benefits include increased methodological rigour, enhanced adolescent acceptability of research and the recalibration of research dynamics for the empowerment of their target beneficiaries. Future studies could benefit from meaningfully involving adolescents through youth advisory groups
Parenting, mental health and economic pathways to prevention of violence against children in South Africa.
BACKGROUND: Parenting programs based on social learning theory have increasing empirical evidence for reducing violence against children. Trials are primarily from high-income countries and with young children. Globally, we know little about how parenting programs work to reduce violence, with no known studies in low or middle-income countries (LMICs). This study examines mechanisms of change of a non-commercialized parenting program, Parenting for Lifelong Health for Teens, designed with the World Health Organization and UNICEF. A cluster randomized trial showed main effects on parenting and other secondary outcomes. We conducted secondary analysis of trial data to investigate five potential mediators of reduced violence against children: improved parenting, adolescent behaviour, caregiver mental health, alcohol/drug avoidance, and family economic strengthening. METHODS: The trial was implemented in rural South Africa with 40 sites, n = 552 family dyads (including adolescents aged 10-18 and primary caregivers). Intervention sites (n = 20) received the 14-session parenting program delivered by local community members, including modules on family budgeting and savings. Control sites (n = 20) received a brief informational workshop. Emotional and physical violence against children/adolescents and each potential mediator were reported by adolescents and caregivers at baseline and 9-13 months post-randomisation. Structural equation modelling was used to test simultaneous hypothesized pathways to violence reduction. RESULTS: Improvements in four pathways mediated reduced violence against children: 1) improved parenting practices, 2) improved caregiver mental health (reduced depression), 3) increased caregiver alcohol/drug avoidance and 4) improved family economic welfare. Improved child behaviour was not a mediator, although it was associated with less violence. CONCLUSIONS: Simultaneously bolstering a set of family processes can reduce violence. Supporting self-care and positive coping for caregivers may be essential in challenging contexts. In countries with minimal or no economic safety nets, linking social learning parenting programs with economic strengthening skills may bring us closer to ending violence against children
The effect of temperature, gradient and load carriage on oxygen consumption, posture and gait characteristics
Purpose The purpose of this experiment was to evaluate the effect of load carriage in a range of temperatures to establish the interaction between cold exposure, the magnitude of change from unloaded to loaded walking and gradient. Methods Eleven participants (19-27 years) provided written informed consent before performing six randomly ordered walking trials in six temperatures (20°C, 10°C, 5°C, 0°C, -5°C and -10°C). Trials involved two unloaded walking bouts before and after loaded walking (18.2 kg) at 4 km.hr⁻¹, on 0% and 10% gradients in 4 minute bouts. Results The change in absolute oxygen consumption (V̇O₂) from the first unloaded bout to loaded walking was similar across all six temperatures. When repeating the second unloaded bout, V̇O₂ at both -5°C and-10°C was greater compared to the first. At -10°C, V̇O₂ was increased from 1.60 ± 0.30 L.min⁻¹ to 1.89 ± 0.51 L.min⁻¹. Regardless of temperature, gradient had a greater effect on V̇O₂ and heart rate (HR) than backpack load. HR was unaffected by temperature. Stride length (SL) decreased with decreasing temperature but trunk forward lean was greater during cold exposure. Conclusion Decreased ambient temperature did not influence the magnitude of change in V̇O₂ from unloaded to loaded walking. However, in cold temperatures, V̇O₂ was significantly higher than in warm conditions. The increased V̇O₂ in colder temperatures at the same exercise intensity is predicted to ultimately lead to earlier onset of fatigue and cessation of exercise. These results highlight the need to consider both appropriate clothing and fitness during cold exposure
Disclosure of physical, emotional and sexual child abuse, help-seeking and access to abuse response services in two South African Provinces
Physical, emotional and sexual child abuse are major problems in South Africa. This study investigates whether children know about post-abuse services, if they disclose and seek services, and what the outcomes of help-seeking behaviour are. It also examines factors associated with request and receipt of services. Confidential self-report questionnaires were completed by adolescents in South Africa as part of a communitybased study of children aged 10-17 (n=3515) in two provinces. Child abuse, disclosure and outcomes of help-seeking were measured using internationally recognized measures. Prevalence of frequent (>weekly) physical abuse was 7.4%, frequent emotional abuse 12.4%, and lifetime contact sexual abuse 9.0%. 98.6% of children could name one suitable confidante or formal service for abuse disclosure, but only 20.1% of abuse victims disclosed. Of those, 72% received help. Most common confidantes were caregivers and teachers. Of all abuse victims, 85.6% did not receive help due to non-disclosure or inactivity of services, and 14.4% received help: 4.9% from formal health or social services and 7.1% through community vigilante action. Emotional abuse, sexual abuse and female gender were associated with higher odds of help-seeking. While children in South Africa showed high knowledge of available services, access to formal services among abused children was low and not all those requesting services received them. Notably fewer children received help from formal services than through community vigilante action. Urgent action is needed to improve service access for child abuse victims
Parenting for lifelong health:A pragmatic cluster randomised controlled trial of a non-commercialised parenting programme for adolescents and their families in South Africa
Objective
To assess the impact of ‘Parenting for Lifelong Health: Sinovuyo Teen’, a parenting programme for adolescents in low- and middle-income countries, on abuse and parenting practices.
Design
Pragmatic cluster randomised control trial.
Setting
40 villages/urban sites (clusters) in the Eastern Cape province, South Africa.
Participants
552 families reporting conflict with their adolescents (aged 10-18).
Intervention
Intervention clusters (n=20) received a 14-session parent and adolescent programme delivered by trained community members. Control clusters (n=20) received a hygiene and hand-washing promotion programme.
Main outcome measures
Primary outcomes: abuse and parenting practices at one and 5-9 months post-intervention. Secondary outcomes: Caregiver and adolescent mental health and substance use, adolescent behavioural problems, social support, exposure to community violence, and family financial wellbeing at 5-9 months post-intervention. Blinding was not possible.
Results
At 5-9 months post-intervention, the intervention was associated with lower abuse (caregiver report incidence rate ratio (IRR) 0.55 (95% CI 0.40 to 0.75, p Conclusions
This parenting programme shows promise for reducing violence, improving parenting and family functioning in low-resource settings.</p
Petiole hyponasty: an ethylene-driven, adaptive response to changes in the environment
Hyponastic (upwardly bending) growth by leaves is a response of numerous plant species to adverse environmental conditions. This review summarises current knowledge on hyponasty with a particular focus on the role of ethylene in regulating this phenomenon and its possible adaptive significance
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