1,040 research outputs found

    PDGF-BB does not accelerate healing in diabetic mice with splinted skin wounds.

    Get PDF
    Topical application of platelet-derived growth factor-BB (PDGF-BB) is considered to accelerate tissue repair of impaired chronic wounds. However, the vast literature is plagued with conflicting reports of its efficacy in animal models and this is often influenced by a wide array of experimental variables making it difficult to compare the results across the studies. To mitigate the confounding variables that influence the efficacy of topically applied PDGF-BB, we used a controlled full thickness splinted excisional wound model in db/db mice (type 2 diabetic mouse model) for our investigations. A carefully-defined silicone-splinted wound model, with reduced wound contraction, controlled splint and bandage maintenance, allowing for healing primarily by reepithelialization was employed. Two splinted 8 mm dorsal full thickness wounds were made in db/db mice. Wounds were topically treated once daily with either 3 µg PDGF-BB in 30 µl of 5% PEG-PBS vehicle or an equal volume of vehicle for 10 days. Body weights, wound contraction, wound closure, reepithelialization, collagen content, and wound bed inflammation were evaluated clinically and histopathologically. The bioactivity of PDGF-BB was confirmed by in vitro proliferation assay. PDGF-BB, although bioactive in vitro, failed to accelerate wound healing in vivo in the db/db mice using the splinted wound model. Considering that the predominant mechanism of wound healing in humans is by re-epithelialization, the most appropriate model for evaluating therapeutics is one that uses splints to prevent excessive wound contraction. Here, we report that PDGF-BB does not promote wound closure by re-epithelialization in a murine splinted wound model. Our results highlight that the effects of cytoactive factors reported in vivo ought to be carefully interpreted with critical consideration of the wound model used

    Genetic Evidence for Two Species of Elephant in Africa

    Get PDF
    Elephants from the tropical forests of Africa are morphologically distinct from savannah or bush elephants. Dart-biopsy samples from 195 free-ranging African elephants in 21 populations were examined for DNA sequence variation in four nuclear genes (1732 base pairs). Phylogenetic distinctions between African forest elephant and savannah elephant populations corresponded to 58% of the difference in the same genes between elephant genera Loxodonta (African) and Elephas (Asian). Large genetic distance, multiple genetically fixed nucleotide site differences, morphological and habitat distinctions, and extremely limited hybridization of gene flow between forest and savannah elephants support the recognition and conservation management of two African species: Loxodonta africana and Loxodonta cyclotis

    The ISCIP Analyst, Volume V, Issue 9

    Full text link
    This repository item contains a single issue of The ISCIP Analyst, an analytical review journal published from 1996 to 2010 by the Boston University Institute for the Study of Conflict, Ideology, and Policy

    The social determinants of health and subjective wellbeing: a comparison of probability and nonprobability online panels

    Get PDF
    As response rates to surveys decline all over the world, researchers are increasingly turning to sampling frames that are easier and cheaper to reach, and that have more predictable response rates. These include nonprobability web panels (NWPs) and probability web panels (PWPs). Although generally more expensive to construct, the latter have been shown in many instances to suffer from fewer biases and deviation from benchmarks. The literature comparing NWPs with PWPs is fedgling. We add to this research area by comparing measures of the social determinants of health that were estimated from a number of NWPs and PWP equivalents with a high-quality benchmark. The analysis finds that, when looking at the distributions of self- assessed health and life satisfaction, probability panels differ less from the gold standard than do nonprobability panels. This supports previous work, although we also show that this conclusion holds when a greater range of control variables is included in the model. However, some of the predictors of health are captured better using the nonprobability panels. In particular, the relationship between area-level disadvantage and health is better captured through a pooled nonprobability sample

    Method and associated apparatus for capturing, servicing, and de-orbiting earth satellites using robotics

    Get PDF
    This invention is a method and supporting apparatus for autonomously capturing, servicing and de-orbiting a free-flying spacecraft, such as a satellite, using robotics. The capture of the spacecraft includes the steps of optically seeking and ranging the satellite using LIDAR; and matching tumble rates, rendezvousing and berthing with the satellite. Servicing of the spacecraft may be done using supervised autonomy, which is allowing a robot to execute a sequence of instructions without intervention from a remote human-occupied location. These instructions may be packaged at the remote station in a script and uplinked to the robot for execution upon remote command giving authority to proceed. Alternately, the instructions may be generated by Artificial Intelligence (AI) logic onboard the robot. In either case, the remote operator maintains the ability to abort an instruction or script at any time, as well as the ability to intervene using manual override to teleoperate the robot.In one embodiment, a vehicle used for carrying out the method of this invention comprises an ejection module, which includes the robot, and a de-orbit module. Once servicing is completed by the robot, the ejection module separates from the de-orbit module, leaving the de-orbit module attached to the satellite for de-orbiting the same at a future time. Upon separation, the ejection module can either de-orbit itself or rendezvous with another satellite for servicing. The ability to de-orbit a spacecraft further allows the opportunity to direct the landing of the spent satellite in a safe location away from population centers, such as the ocean

    Impact of major depression on cardiovascular outcomes for individuals with hypertension: prospective survival analysis in UK Biobank

    Get PDF
    Objectives: To assess whether a history of major depressive disorder (MDD) in middle-aged individuals with hypertension influences first-onset cardiovascular disease outcomes. Design: Prospective cohort survival analysis using Cox proportional hazards regression with a median follow-up of 63 months (702 902 person-years). Four mutually exclusive groups were compared: hypertension only (n=56 035), MDD only (n=15 098), comorbid hypertension plus MDD (n=12 929) and an unaffected (no hypertension, no MDD) comparison group (n=50 798). Setting: UK Biobank. Participants: UK Biobank participants without cardiovascular disease aged 39–70 who completed psychiatric questions relating International Classification of Diseases-10 Revision (ICD-10) diagnostic criteria on a touchscreen questionnaire at baseline interview in 2006–2010 (n=134 860). Primary and secondary outcome measures: First-onset adverse cardiovascular outcomes leading to hospital admission or death (ICD-10 codes I20–I259, I60–69 and G45–G46), adjusted in a stepwise manner for sociodemographic, health and lifestyle features. Secondary analyses were performed looking specifically at stroke outcomes (ICD-10 codes I60–69 and G45–G46) and in gender-separated models. Results: Relative to controls, adjusted HRs for adverse cardiovascular outcomes were increased for the hypertension only group (HR 1.36, 95% CI 1.22 to 1.52) and were higher still for the comorbid hypertension plus MDD group (HR 1.66, 95% CI 1.45 to 1.9). HRs for the comorbid hypertension plus MDD group were significantly raised compared with hypertension alone (HR 1.22, 95% CI 1.1 to 1.35). Interaction measured using relative excess risk due to interaction (RERI) and likelihood ratios (LRs) were identified at baseline (RERI 0.563, 95% CI 0.189 to 0.938; LR p=0.0116) but not maintained during the follow-up. Limitations: Possible selection bias in UK Biobank and inability to assess for levels of medication adherence. Conclusions: Comorbid hypertension and MDD conferred greater hazard than hypertension alone for adverse cardiovascular outcomes, although evidence of interaction between hypertension and MDD was inconsistent over time. Future cardiovascular risk prediction tools may benefit from the inclusion of questions about prior history of depressive disorders

    Acute Cardiometabolic Responses to Medicine Ball Interval Training in Children

    Get PDF
    International Journal of Exercise Science 11(4): 886-899, 2018. Medicine ball interval training (MBIT) has been found to be an effective exercise modality in fitness programs, yet the acute physiological responses to this type of this exercise in youth are unknown. The purpose of this study was to examine the acute cardiometabolic responses to MBIT in children. Fourteen children (mean age 10.1 ± 1.3 yr) were tested for peak oxygen uptake (VO2peak) on a treadmill and subsequently (\u3e 48 hours later) performed a progressive 10 min MBIT protocol of 5 exercises (EX): standing marches (EX1), alternating lunges (EX2), squat swings (EX3), chest passes (EX4) and double arm slams (EX5). A 2.3 kg medicine ball was used for all trials and each exercise was performed twice for 30 sec with a 30 sec rest interval between sets and exercises. Participants exercised while connected to a metabolic system and heart rate (HR) monitor. During the MBIT protocol, mean HR significantly (p\u3c0.05, η2= 0.89) increased from 121.5 ± 12.3 bpm during EX1 to 178.3 ± 9.4 bpm during EX5 and mean VO2 significantly (p\u3c0.05, η2= 0.88) increased from 15.5 ± 2.9 ml ×kg-1×min-1during EX1 to 34.9 ± 5.1 ml ×kg-1×min-1during EX5. Mean HR and VO2values during MBIT ranged from 61.1% to 89.6% of HRpeak and from 28.2% to 63.5% of VO2peak. These descriptive data indicate that MBIT can pose a moderate to vigorous cardiometabolic stimulus in children

    Local Wellness Policy 5 Years Later: Is It Making a Difference for Students in Low-Income, Rural Colorado Elementary Schools?

    Get PDF
    IntroductionThe federally mandated Local Wellness Policy (LWP) was intended to promote student health in schools. This study assesses the 5-year effects of the LWP on the health practices of rural elementary schools in Colorado. MethodsOne year before and 5 years after the LWP mandate, a survey was administered to a random sample of principals, physical education (PE) teachers, and food-service managers in 45 rural, low-income elementary schools in Colorado. Response rates were 71% in 2005 and 89% in 2011. ResultsMinutes for PE and recess did not increase, nor did offerings of fresh fruits and vegetables. More schools adopted policies prohibiting teachers from taking recess away as punishment (9.7% in 2005 vs 38.5% in 2011, P = .02) or for making up missed instructional time, class work, or tests in other subjects (3.2% in 2005 vs 28.2% in 2011, P = .03). More schools scheduled recess before lunch (22.6% in 2005 vs 46.2% in 2011, P = .04) and developed policies for vending machines (42.9% in 2005 vs 85.7% in 2011, P = .01) and parties (21.4% in 2005 vs 57.9% in 2011, P = .004). ConclusionChanges in school practices are modest, and arguably the important school practices such as increased PE and recess time and increased offerings of fruits and vegetables in the lunch line have not changed in the 5 years since the mandate went into effect. Further investigation is needed to identify the knowledge, skills, and attitudes as well as financial and physical resources required for school administrators to make changes in school practices
    • …
    corecore