To investigate relations of walking, bicycling and vehicle time to neighborhood walkability and total physical activity in youth.
Participants (N=690) were from 380 census block groups of high/low ...walkability and income in two US regions. Home neighborhood residential density, intersection density, retail density, entertainment density and walkability were derived using GIS. Minutes/day of walking, bicycling and vehicle time were derived from processing algorithms applied to GPS. Accelerometers estimated total daily moderate-to-vigorous physical activity (MVPA). Models were adjusted for nesting of days (N=2987) within participants within block groups.
Walking occurred on 33%, active travel on 43%, and vehicle time on 91% of the days observed. Intersection density and neighborhood walkability were positively related to walking and bicycling and negatively related to vehicle time. Residential density was positively related to walking.
Increasing walking in youth could be effective in increasing total physical activity. Built environment findings suggest potential for increasing walking in youth through improving neighborhood walkability.
To compare adolescents' physical activity at home, near home, at school, near school, and at other locations.
Adolescents (N = 549) were ages 12 to 16 years (49.9% girls, 31.3% nonwhite or Hispanic) ...from 447 census block groups in 2 US regions. Accelerometers and Global Positioning System devices assessed minutes of and proportion of time spent in moderate to vigorous physical activity (MVPA) in each of the 5 locations. Mixed-effects regression compared MVPA across locations and demographic factors.
Forty-two percent of adolescents' overall MVPA occurred at school, 18.7% at home, 18.3% in other (nonhome, nonschool) locations, and 20.6% near home or school. Youth had 10 more minutes (30% more) of overall MVPA on school days than on nonschool days. However, the percentage of location time spent in MVPA was lowest at school (4.8% on school days) and highest near home and near school (9.5%-10.4%). Girls had 2.6 to 5.5 fewer minutes per day of MVPA than boys in all locations except near school.
Although a majority of adolescents' physical activity occurred at school, the low proportion of active time relative to the large amount of time spent at school suggests potential for increasing school-based activity. Increasing time spent in the neighborhood appears promising for increasing overall physical activity, because a high proportion of neighborhood time was active. Increasing youth physical activity to support metabolic health requires strategies for increasing use of physical activity-supportive locations (eg, neighborhoods) and environmental and program improvements in unsupportive locations (eg, schools, homes).
•We develop thresholds for environmental features supporting physical activity (PA).•Travel behavior data are mapped with objectively measured environmental data.•Optimal values for key environmental ...features supporting PA are quantified.•Systematic heterogeneity must be accounted in developing thresholds.•The thresholds can serve as “guiding tool” for policymakers, planners/engineers.
A novel evidence-based methodology is presented for determining place-based thresholds of objectively measured built environment features’ relationships with active travel. Using an innovative machine-learning based Generalized Additive Modeling framework, systematic heterogeneity fundamental to the development of well-justified and objective environmental thresholds is accounted for. The methodology is employed to model an individual’s likelihood of transport walking as a function of environmental factors using California Household Travel Survey linked with comprehensive built environment data. The results reveal strong and complex non-linear dependencies of likelihood of transport walking on environmental features that cannot be quantified using standard threshold detection methods. Thresholds for key environmental features to enhance active travel vary significantly across different socioeconomic groups. Accounting for strong income-based differences in development of environmental benchmarks is emphasized. The thresholds can serve as a useful guiding tool for policymakers, planners, engineers, and public health officials to track existing environmental conditions and healthy behaviors.
Youth are active in multiple locations, but it is unknown whether more physical activity in one location is associated with less in other locations. This cross-sectional study examines whether on ...days with more physical activity in a given location, relative to their typical activity in that location, youth had less activity in other locations (i.e., within-person associations/compensation).
Participants were 528 adolescents, ages 12 to 16 (M = 14.12, SD = 1.44, 50% boys, 70% White non-Hispanic). Accelerometer and Global Positioning System devices were used to measure the proportion of time spent in moderate-to-vigorous physical activity (MVPA) in five locations: home, home neighborhood, school, school neighborhood, and other locations. Mixed-effects regression was used to examine within-person associations of MVPA across locations and moderators of these associations.
Two of ten within-participant associations tested indicated small amounts of compensation, and one association indicated generalization across locations. Higher at-school MVPA (relative to the participant's average) was related to less at-home MVPA and other-location MVPA (Bs = -0.06 min/day). Higher home-neighborhood MVPA (relative to the participant's average) was related to more at-home MVPA (B = 0.07 min/day). Some models showed that compensation was more likely (or generalization less likely) in boys and non-whites or Hispanic youth.
Consistent evidence of compensation across locations was not observed. A small amount of compensation was observed for school physical activity, suggesting that adolescents partially compensated for high amounts of school activity by being less active in other locations. Conversely, home-neighborhood physical activity appeared to carry over into the home, indicating a generalization effect. Overall these findings suggest that increasing physical activity in one location is unlikely to result in meaningful decreases in other locations. Supporting physical activity across multiple locations is critical to increasing overall physical activity in youth.
To investigate whether adolescents cluster into profiles based on where they accumulate moderate-to-vigorous physical activity (MVPA), if overall MVPA differs across profiles, and if walking to ...school and participant and neighborhood characteristics explain profile membership.
Adolescents (N=528; mean age=14.12±1.44; 50% girls) wore accelerometers and Global Positioning Systems (GPS) trackers for 3.9±1.5 days to assess MVPA minutes in five locations: at home, at school, in home neighborhood, in school neighborhood, and other. Walking to school and participant characteristics were assessed by questionnaire, and neighborhood environment by Geographic Information Systems (GIS). Latent profile analysis (LPA) was used to identify profiles/groups of participants based on accumulation of physical activity across the five locations. Mixed-effects regression tested differences in overall MVPA, walking to school, and other characteristics across profiles.
Four initial profiles emerged: one Insufficiently Active profile and three "Active" profiles (Active Around School, Active Home Neighborhood, and Active Other Locations). The Insufficiently Active profile emerging from the first LPA (90% of participants) was further separated into four profiles in a second LPA: Insufficiently Active, and three additional "Active" profiles (Moderately-Active Around School, Moderately-Active Home Neighborhood, and Active At Home). Those in the six Active profiles had more overall MVPA (41.1-92.7 minutes/day) than those in the two Insufficiently Active profiles (34.5-38.3 minutes/day). Variables that differed across profiles included walking to school, sports/athletic ability, and neighborhood walkability.
Although most participants did not meet the MVPA guideline, the six Active profiles showed the places in which many adolescents were able to achieve the 60-minute/day guideline. The home and school neighborhood (partly through walking to school), "other" locations, and to a lesser extent the home, appeared to be key sources for physical activity that distinguished active from insufficiently active adolescents. Finding the right match between the individual and physical activity source/location may be a promising strategy for increasing active travel and MVPA in adolescents.
Controlling the rate of softening to extend shelf life was a key target for researchers engineering genetically modified (GM) tomatoes in the 1990s, but only modest improvements were achieved. ...Hybrids grown nowadays contain 'non-ripening mutations' that slow ripening and improve shelf life, but adversely affect flavor and color. We report substantial, targeted control of tomato softening, without affecting other aspects of ripening, by silencing a gene encoding a pectate lyase.
Group B streptococcal (GBS) infection remains the most common cause of neonatal early-onset sepsis and a significant cause of late-onset sepsis among young infants. Administration of intrapartum ...antibiotic prophylaxis is the only currently available effective strategy for the prevention of perinatal GBS early-onset disease, and there is no effective approach for the prevention of late-onset disease. The American Academy of Pediatrics joins with the American College of Obstetricians and Gynecologists to reaffirm the use of universal antenatal microbiologic-based testing for the detection of maternal GBS colonization to facilitate appropriate administration of intrapartum antibiotic prophylaxis. The purpose of this clinical report is to provide neonatal clinicians with updated information regarding the epidemiology of GBS disease as well current recommendations for the evaluation of newborn infants at risk for GBS disease and for treatment of those with confirmed GBS infection. This clinical report is endorsed by the American College of Obstetricians and Gynecologists (ACOG), July 2019, and should be construed as ACOG clinical guidance.
Background Sensitization to house dust mite allergens is strongly correlated with asthma. Der p 7 elicits strong IgE antibody and T-cell responses in patients with mite allergy. However, the ...structure and biological function of this important allergen are unknown. Allergen function might contribute to allergenicity, as shown for the protease activity of group 1 mite allergens and the interaction with the innate immune system by group 2 mite allergens. Objective We sought to determine the crystal structure of Der p 7 and to investigate its biological function. Methods X-ray crystallography was used to determine the Der p 7 structure. Nuclear magnetic resonance analysis and biochemical assays were used to examine the binding of Der p 7 to predicted ligands. Results Der p 7 has an elongated structure, with two 4-stranded antiparallel β-sheets that wrap around a long C-terminal helix. The fold of Der p 7 is similar to that of LPS-binding protein (LBP), which interacts with Toll-like receptors after binding LPS and other bacterially derived lipid ligands. Nuclear magnetic resonance and biochemical assays indicate that Der p 7 does not bind LPS but binds with weak affinity to the bacterial lipopeptide polymyxin B in the predicted binding site of Der p 7. Conclusions Der p 7 binds a bacterially derived lipid product, a common feature of some allergens. The finding that the group 7, as well as the group 2, mite allergens are structurally similar to different proteins in the Toll-like receptor pathway further strengthens the connections between dust mites, innate immunity, and allergy.
Oceanic whitetip sharks
Carcharhinus longimanus
aggregate at Columbus Point, Cat Island, The Bahamas, in at least April and May. We show that signs of putative mating activity (i.e. bite wounds) on ...mature females, which dominate the aggregation, are exceedingly rare at that time, but may be more common in July. Male plasma testosterone concentrations also suggest that spermatogenesis occurs in April and May and copulation is underway or has just ended by July. We support these preliminary data with direct observations of putative precopulatory behavior made at Columbus Point in July 2019. Using 25 min of video footage from the event, we identify common shark mating behaviors such as echelon or parallel swimming, following, shielding, nosing, and biting. We also describe the ‘circle-back’, a newly observed behavior where the male orients to the trail of the female, possibly to investigate olfactory cues. Based on these 3 parallel lines of evidence, we hypothesize that mating could occur in the eastern Bahamas as early as May, but is probably concentrated in midsummer (i.e. July), and that Columbus Point, Cat Island, may be a mating habitat for the oceanic whitetip shark.
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