Interpreting the seasonal cycles of atmospheric oxygen and carbon dioxide concentrations at American Samoa Observatory

We present seven years of atmospheric O2/N2 ratio and CO2 concentration data measured from flask samples collected at American Samoa. These data are unusual, exhibiting higher short-term variability, and seasonal cycles not in phase with other sampling stations. The unique nature of atmospheric data from Samoa has been noted previously from measurements of CO2, methyl chloroform, and ozone. With our O2 data, we observe greater magnitude in the short-term variability, but, in contrast, no clear seasonal pattern to this variability. This we attribute to significant regional sources and sinks existing for O2 in both hemispheres, and a dependence on both the latitudinal and altitudinal origins of air masses. We also hypothesize that some samples exhibit a component of "older" air, demonstrating recirculation of air within the tropics. Our findings could be used to help constrain atmospheric transport models which are not well characterized in tropical regions

The Double-edged Sword of Pedagogy: Modeling the Effect of Pedagogical Contexts on Preschoolers’ Exploratory Play

URL to paper from conference siteHow does explicit instruction affect exploratory play and learning? We present a model that captures pedagogical assumptions (adapted from Shafto and Goodman, 2008) and test the model with a novel experiment looking at 4-year-olds’ exploratory play in pedagogical and non-pedagogical contexts. Our findings are consistent with the model predictions: preschool children limit their exploration in pedagogical contexts, spending most of their free play performing only the demonstrated action. By contrast, children explore broadly both at baseline and after an accidental demonstration. Thus pedagogy constrains children’s exploration for better and for worse; children learn the demonstrated causal relationship but are less likely than children in non-pedagogical contexts to discover and learn other causal relationships.American Psychological Foundation (Elizabeth Munsterberg Koppitz Fellowship)Templeton FoundationJames S. McDonnell Foundatio

Microbial Diversity in the Eukaryotic SAR Clade: Illuminating the Darkness Between Morphology and Molecular Data

Despite their diversity and ecological importance, many areas of the SAR—Stramenopila, Alveolata, and Rhizaria—clade are poorly understood as the majority (90%) of SAR species lack molecular data and only 5% of species are from well-sampled families. Here, we review and summarize the state of knowledge about the three major clades of SAR, describing the diversity within each clade and identifying synapomorphies when possible. We also assess the “dark area” of SAR: the morphologically described species that are missing molecular data. The majority of molecular data for SAR lineages are characterized from marine samples and vertebrate hosts, highlighting the need for additional research effort in areas such as freshwater and terrestrial habitats and “non-vertebrate” hosts. We also describe the paucity of data on the biogeography of SAR species, and point to opportunities to illuminate diversity in this major eukaryotic clade. See also the video abstract above

Frequently endorsed cognitive and physical activities among community-dwelling older adults

Background Despite the established benefits of cognitive and physical activity, a paucity of research examines the specific activities older adults favor, particularly those meeting the nationally recommended minimum duration of \u3e 30 minutes per session. Material/Methods 260 non-demented, community-dwelling participants aged 70 and above self-reported the duration of their participation in 26 cognitive and physical activities during a typical week. Overall activity engagement was investigated by sex and educational level. Results The most endorsed physical activities were walking, stretching/yoga and gardening, while the most endorsed cognitive activities were reading magazines/newspapers, reading books, and doing crosswords. Walking (p = .048), swimming (p = .008), reading magazines/ newspapers (p=.011), writing (p=.001), and attending lectures (p = .007) were more common among those with \u3e 12 years of education, while reading books (p = .039) and sewing/knitting (p = .040) were more common among those with ≤ 12 years of education. Doing crossword puzzles (p = .003), sewing/knitting (p = .001), and dancing (p = .015) were more common among females, while weight training (p = .009) and fishing (p = .003) were more common among males. Conclusions Overall, results revealed several statistically significant activity engagement differences by sex and education. Findings are discussed in relation to enhancing older adults’ participation in activities that may improve their overall functioning

Household wealth and neurocognitive development disparities among school-aged children in Nepal.

BACKGROUND: Wealth disparities in child developmental outcomes are well documented in developed countries. We sought to (1) describe the extent of wealth-based neurocognitive development disparities and (2) examine potential mediating factors of disparities among a population-based cohort of children in rural Nepal. METHODS: We investigated household wealth-based differences in intellectual, executive and motor function of n = 1692 children aged between 7 and 9 years in Nepal. Using linear mixed models, wealth-based differences were estimated before and after controlling for child and household demographic characteristics. We further examined wealth-based differences adjusted for three sets of mediators: child nutritional status, home environment, and schooling pattern. RESULTS: We observed a positive gradient in child neurocognitive performance by household wealth. After adjusting for child and household control factors, disparities between children in the highest and lowest wealth quintiles persisted in intellectual and motor function, but not executive function. No statistically significant wealth-based differentials in outcomes remained after accounting for nutritional status, home environment, and schooling patterns. The largest differences in neurocognitive development were associated with schooling pattern. CONCLUSIONS: Household wealth patterns child neurocognitive development in rural Nepal, likely through its influence on nutritional status, the home environment, and schooling. In the current context, improving early and regular schooling in this setting is critical to addressing wealth-based disparities in outcomes

Detection and diversity of a putative novel heterogeneous polymorphic proline-glycine repeat (Pgr) protein in the footrot pathogen Dichelobacter nodosus

Dichelobacter nodosus, a Gram-negative anaerobic bacterium, is the essential causative agent of footrot in sheep. Currently, depending on the clinical presentation in the field, footrot is described as benign or virulent; D. nodosus strains have also been classified as benign or virulent, but this designation is not always consistent with clinical disease. The aim of this study was to determine the diversity of the pgr gene, which encodes a putative proline-glycine repeat protein (Pgr). The pgr gene was present in all 100 isolates of D. nodosus that were examined and, based on sequence analysis had two variants, pgrA and pgrB. In pgrA, there were two coding tandem repeat regions, R1 and R2: different strains had variable numbers of repeats within these regions. The R1 and R2 were absent from pgrB. Both variants were present in strains from Australia, Sweden and the UK, however, only pgrB was detected in isolates from Western Australia. The pgrA gene was detected in D. nodosus from tissue samples from two flocks in the UK with virulent footrot and only pgrB from a flock with no virulent or benign footrot for >10 years. Bioinformatic analysis of the putative PgrA protein indicated that it contained a collagen-like cell surface anchor motif. These results suggest that the pgr gene may be a useful molecular marker for epidemiological studies

Cosmogenic 11C production and sensitivity of organic scintillator detectors to pep and CNO neutrinos

Several possible background sources determine the detectability of pep and CNO solar neutrinos in organic liquid scintillator detectors. Among such sources, the cosmogenic 11C nuclide plays a central role. 11C is produced underground in reactions induced by the residual cosmic muon flux. Experimental data available for the effective cross section for 11C by muons indicate that 11C will be the dominant source of background for the observation of pep and CNO neutrinos. 11C decays are expected to total a rate 2.5 (20) times higher than the combined rate of pep and CNO neutrinos in Borexino (KamLAND) in the energy window preferred for the pep measurement, between 0.8 and 1.3 MeV. This study examines the production mechanism of 11C by muon-induced showers in organic liquid scintillators with a novel approach: for the first time, we perform a detailed ab initio calculation of the production of a cosmogenic nuclide, 11C, taking into consideration all relevant production channels. Results of the calculation are compared with the effective cross sections measured by target experiments in muon beams. This paper also discusses a technique for reduction of background from 11C in organic liquid scintillator detectors, which allows to identify on a one-by-one basis and remove from the data set a large fraction of 11C decays. The background reduction technique hinges on an idea proposed by Martin Deutsch, who suggested that a neutron must be ejected in every interaction producing a 11C nuclide from 12C. 11C events are tagged by a three-fold coincidence with the parent muon track and the subsequent neutron capture on protons.Comment: 11 pages, 6 figures; added one section detailing comparison with previous estimates; added reference

Lost Branches on the Tree of Life

Failure to archive published data can impede reproducibility and inhibit downstream synthesis. Alarmingly, we estimate that ∼70% of existing DNA sequence alignments/phylogenetic trees, representing much of the underpinning of modern phylogenetic analysis, are no longer accessible. The evolutionary biology community needs to adopt policies ensuring that data are publicly archived upon publication

A Qualitative Analysis of Factors Influencing HPV Vaccine Uptake in Soweto, South Africa among Adolescents and Their Caregivers

Background: In South Africa, the prevalence of oncogenic Human Papillomavirus (HPV) may be as high as 64%, and cervical cancer is the leading cause of cancer-related death among women. The development of efficacious prophylactic vaccines has provided an opportunity for primary prevention. Given the importance of psycho-social forces in vaccine uptake, we sought to elucidate factors influencing HPV vaccination among a sample of low-income South African adolescents receiving the vaccine for the first time in Soweto. Methods: The HPV vaccine was introduced to adolescents in low-income townships throughout South Africa as part of a nationwide trial to understand adolescent involvement in future vaccine research targeting human immunodeficiency virus (HIV). We performed in-depth semi-structured interviews with purposively-sampled adolescents and their care providers to understand what forces shaped HPV vaccine uptake. Interviews were recorded, transcribed, translated, and examined using thematic analysis. Results: Of 224 adolescents recruited, 201 initiated the vaccine; 192 (95.5%) received a second immunization; and 164 (81.6%) completed three doses. In our qualitative study of 39 adolescent-caregiver dyads, we found that factors driving vaccine uptake reflected a socio-cultural backdrop of high HIV endemnicity, sexual violence, poverty, and an abundance of female-headed households. Adolescents exercised a high level of autonomy and often initiated decision-making. Healthcare providers and peers provided support and guidance that was absent at home. The impact of the HIV epidemic on decision-making was substantial, leading participants to mistakenly conflate HPV and HIV. Conclusions: In a setting of perceived rampant sexual violence and epidemic levels of HIV, adolescents and caregivers sought to decrease harm by seeking a vaccine targeting a sexually transmitted infection (STI). Despite careful consenting, there was confusion regarding the vaccine’s target. Future interventions promoting STI vaccines will need to provide substantial information for participants, particularly adolescents who may exercise a significant level of autonomy in decision-making