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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.icarus.2010.04.013 Byline: Peter M. Goldreich (a)(b), Jonathan L. Mitchell (b)(c) Keywords: Europa; Titan; Resonances, Spin-orbit Abstract: A number of synchronous moons are thought to harbor water oceans beneath their outer ice shells. A subsurface ocean frictionally decouples the shell from the interior. This has led to proposals that a weak tidal or atmospheric torque might cause the shell to rotate differentially with respect to the synchronously rotating interior. Applications along these lines have been made to Europa and Titan. However, the shell is coupled to the ocean by an elastic torque. As a result of centrifugal and tidal forces, the ocean would assume an ellipsoidal shape with its long axis aligned toward the parent planet. Any displacement of the shell away from its equilibrium position would induce strains thereby increasing its elastic energy and giving rise to an elastic restoring torque. In the investigation reported on here, the elastic torque is compared with the tidal torque acting on Europa and the atmospheric torque acting on Titan. Regarding Europa, it is shown that the tidal torque is far too weak to produce stresses that could fracture the ice shell, thus refuting an idea that has been widely advocated. Instead, it is suggested that the cracks arise from time-dependent stresses due to non-hydrostatic gravity anomalies from tidally driven, episodic convection in the satellite's interior. Two years of Cassini RADAR observations of Titan's surface have been interpreted as implying an angular displacement of [approximately equal to]0.24[degrees] relative to synchronous rotation. Compatibility of the amplitude and phase of the observed non-synchronous rotation with estimates of the atmospheric torque requires that Titan's shell be decoupled from its interior. We find that the elastic torque balances the seasonal atmospheric torque at an angular displacement [less than or approximately equal to]0.05[degrees], effectively coupling the shell to the interior. Moreover, if Titan's surface were spinning faster than synchronous, the tidal torque tending to restore synchronous rotation would almost certainly be larger than the atmospheric torque. There must either be a problem with the interpretation of the radar observations, or with our basic understanding of Titan's atmosphere and/or interior. Author Affiliation: (a) Caltech, 1200E. California Blvd., Pasadena, CA 91125, United States (b) Institute for Advanced Study, Princeton, NJ 08540, United States (c) Earth & Space Sciences, Atmospheric & Oceanic Sciences, Institute for Geophysics & Planetary Physics, University of California at Los Angeles, Los Angeles, CA 90095, United States Article History: Received 30 September 2009; Revised 16 April 2010; Accepted 16 April 2010

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.icarus.2009.03.043 Byline: Jonathan L. Mitchell (a), Raymond T. Pierrehumbert (b), Dargan M.W. Frierson (c), Rodrigo Caballero (d) Keywords: Titan; Atmospheres; Dynamics Abstract: We identify mechanisms controlling the distribution of methane convection and large-scale circulation in a simplified, axisymmetric model atmosphere of Titan forced by gray radiation and moist (methane) convection. The large-scale overturning circulation, or Hadley cell, is global in latitudinal extent and provides fundamental control of precipitation and tropospheric winds. The precipitating, large-scale updraft regularly oscillates in latitude with seasons. The distance of greatest poleward excursion of the Hadley cell updraft is set by the mass of the convective layer of the atmosphere; convection efficiently communicates seasonal warming of the surface through the cold and dense lower atmosphere, increasing the heat capacity of the system. The presence of deep, precipitating convection introduces three effects relative to the case with no methane latent heating: (1) convection is narrowed and enhanced in the large-scale updraft of the Hadley cell; (2) the latitudinal amplitude of Hadley cell updraft oscillations is decreased; and (3) a time lag is introduced. These effects are observable in the location and timing of convective methane clouds in Titan's atmosphere as a function of season. A comparison of simulations over a range of convective regimes with available observations suggest methane thermodynamic-dynamic feedback is important in the Titan climate. Author Affiliation: (a) Institute for Advanced Study, Princeton, NJ 08540, USA (b) Department of Geophysical Sciences, The University of Chicago, Chicago, IL 60637, USA (c) Department of Atmospheric Sciences, The University of Washington, Seattle, WA, USA (d) School of Mathematical Sciences, University College Dublin, Dublin, Ireland Article History: Received 17 March 2008; Revised 25 March 2009; Accepted 30 March 2009

The mouse submandibular gland (SMG) epithelium undergoes extensive morphogenetic branching during embryonic development as the first step in the establishment of its glandular structure. However, the specific signaling pathways required for SMG branching morphogenesis are not well understood. Using E13 mouse SMG organ cultures, we showed that inhibitors of phosphatidylinositol 3-kinase (PI 3-kinase), wortmannin and LY294002, substantially inhibited branching morphogenesis in SMG. Branching morphogenesis of epithelial rudiments denuded of mesenchyme was inhibited similarly, indicating that PI 3-kinase inhibitors act directly on the epithelium. Immunostaining and Western analysis demonstrated that the p85 isoform of PI 3-kinase is expressed in epithelium at levels higher than in the mesenchyme. A target of PI 3-kinase, Akt/protein kinase B (PKB), showed decreased phosphorylation at [Ser.sup.473] by Western analysis in the presence of PI 3-kinase inhibitors. The major lipid product of PI 3-kinase, phosphafidylinositol 3,4,5-tfisphosphate ([PIP.sub.3]), was added exogenously to SMG via a membrane-transporting carrier in the presence of PI 3-kinase inhibitors and was found to stimulate cleft formation, the first step of branching morphogenesis. Together, these data indicate that PI 3-kinase plays a role in the regulation of epithelial branching morphogenesis in mouse SMG acting through a [PIP.sub.3] pathway. Keywords: Branching morphogenesis; Salivary gland; Submandibular gland; Organ culture; Phosphatidylinositol 3-kinase; Phosphatidylinositol 3,4,5-trisphosphate; Akt; Inhibitors; Mouse; Time-lapse microscopy

The purpose of the study was to quantify changes in sleep during the middle-to-high school transition and determine if changes in sleep differ by sociodemographic characteristics. Adolescents were enrolled in eighth grade and followed into ninth grade (N = 110; 2,470 nights observed). The outcomes were actigraphy-estimated sleep duration, sleep onset, sleep offset, and sleep sufficiency (≥8 hours of sleep). The exposures were school grade (eighth or ninth), school night status (school or nonschool), sex (female or male), and race (white, black, or other). On school nights, sleep duration declined by 25.8 minutes per night (p <.001) from eighth to ninth grade. There was no change in sleep duration on nonschool nights. Timing of sleep onset was 22.2 minutes later on school nights (p <.001) and 17.4 minutes later on nonschool nights (p <.001) in ninth grade. Timing of sleep offset did not change on school mornings but was 22.2 minutes later on nonschool mornings (p <.001) in ninth grade. The proportion of school nights (and nonschool nights) with sleep duration ≥8 hours was 9.4% (38.3%) in eighth grade and 5.7% (35.9%) in ninth grade. The odds of sleeping ≥8 hours per night was 42% lower in ninth grade, compared toeighth grade (odds ratio =.58; 95% confidence interval:.37,.91). Males were 59% less likely to sleep ≥8 hours per night. Black adolescents were 51% less likely to sleep ≥8 hours per night. Insufficient sleep is highly prevalent, especially on school nights and among male and black adolescents, and this problem worsens with the transition to high school. [ABSTRACT FROM AUTHOR]

To determine the precision, accuracy, and unique analysis challenges of HSA in children. Hip structural analysis (HSA) variables, a collection of 10 measures including cross-sectional area (CSA), cross-sectional inertia (CSI), and buckling ratio (BR), have been shown to be independent risk factors in determining fracture risk in adults, but there have been few studies reporting the utility and accuracy of HSA in children. Previous work has described the precision of HSA in adults, but the precision and unique challenges of the HSA protocol in children is unexplored. Here we describe the unique challenges, precision, and quality assurance protocol of pediatric HSA measures in a large cohort of over 2,500 children. This is a retrospective analysis of prospectively collected DXA scans acquired as part of two studies, the Bone Mineral Density in Childhood Study (BMDCS) and the Genome-wide Analysis Study (GWAS). The combined sample consisted of 2,514 children (10,787 scans, 1,271 girls) aged from 5 to 21 years. The proximal femur DXA scans were acquired on five Hologic systems (Hologic, Inc., Marlborough, MA) of similar models (A and W) with up to eight years of annual follow-up between 2002 and 2009. All scans were analyzed centrally by the authors using one technologist using APEX 3.4 software. A unique and comprehensive quality assurance check was completed for all scans including a review of the acquisition criteria set by ISCD and a review of the automatically placed HSA region's narrow neck (NN), intertrochanteric (IT), and femoral shaft (FS) region of interests. During processing, regions were either repositioned or eliminated on DXA imaging. Duplicate scans were performed on 150 children (71 girls) for precision assessment. Specific HSA quality control (QC) codes were generated for this particular analysis in accordance with the author's criteria. Short-term precision estimates were calculated as the RMSE and %CV. QA codes were assigned to the NN, IT, and FS boxes that were either incorrectly positioned or invalidated. Of the entire dataset under 10% of NN and FS boxes needed to be repositioned and none were invalidated. Figure 1 provides an example of proper placement of the IT box (at a 45-degree angle) in between the greater and lesser trochanter. If the angle of the IT box is either < 10 or >25 degrees, the IT box was invalidated. In this study, 100% of the IT boxes needed to be repositioned and 54% remained invalid. Multiple reasons were identified for an invalid scan region including the unavoidable presence of a growth plate in the hip scans for participants less than 15 years old, as shown in Figure 1. All HSA precision over all age groups ranged was less than 6% CV except for the NN Buckling ratio and Cross-sectional Inertia. In general, the precision error was lower in the older ages versus the younger participants. See Table 1. We conclude that HSA creates precise estimates in children that are comparable to that in adults for the femur neck and shaft but not the intertrochanteric region. Thorough quality assurance procedures must be in place to safeguard against poor region placement due to the size of the bone. [ABSTRACT FROM AUTHOR]

To investigate the precision and analysis protocol for VAT, SAT, and VAT/SAT ratio and explore precision covariates in a large prospective sample of children and young adults. Visceral adipose tissue (VAT) has been linked to poor metabolic health, including obesity and metabolic syndrome. Excess VAT can have an early onset during childhood. VAT measured by DXA has been shown to well represent CT and MRI VAT in adults. However, few studies have shown repeatability and quality assurance issues for children. These data have been collected as a part of a retrospective analysis of prospectively collected DXA scans acquired as part of two studies, the Bone Mineral Density in Childhood Study (BMDCS) and the Genome-wide Analysis Study (GWAS). The combined sample consisted of 2,514 children (10,787 scans, 1,271 girls) aged from 5 to 21 years. The whole-body DXA scans were acquired on five Hologic systems (Hologic, Inc., Marlborough, MA) of similar models (A and W) with up to eight years of annual follow-up between 2002 and 2009. All scans were analyzed centrally by the authors using one technologist using APEX 3.4 software. A unique and comprehensive quality assurance check was completed for all scans including a review of the acquisition criteria set by ISCD and a review of the automatically placed VAT regions of interest. During processing, regions were either repositioned or eliminated on DXA imaging. Duplicate scans were available on up to 150 children (71 girls) for precision assessment which was used to evaluate test-retest precision, both overall and by age group. Short-term precision estimates were calculated as the root mean square error and percent coefficients of variation (RMSE %CV). VAT codes were broken up into either invalidated scans or incorrectly positioned and subsequently corrected. Precision for all children in terms of %CV and RMSE (g) was 7.9% (12.8g) and 4.1% (24.7g) for VAT and SAT respectively. See Table 1. In general, the late teen group had the lowest precision error CV% (3.1-9.0) when compared to all other groups, and preteens had the highest %CV range (4.6-11.4). A pair of scans is shown in Figure 1 where the auto analyzer correctly positioned the regions of interest for the first scan but not for the second scan. Seven percent (752 scans) of the total number of scans had to be manually adjusted. We conclude that the precision of the VAT regions is dependent on age where the precision for late teens is similar to that of adults. All Hologic DXA whole body scans in children should be manually reviewed for region placement for the most accurate and precise results. [ABSTRACT FROM AUTHOR]

Background & Aims Little is known about outcomes of patients with autoimmune hepatitis (AIH) who have a suboptimal outcome to standard therapy and are then given mycophenolate mofetil as rescue therapy. We evaluated the efficacy and safety of mycophenolate mofetil in patients failed by or intolerant to corticosteroids, with or without azathioprine. Methods We performed a retrospective study of 105 patients with AIH who received mycophenolate mofetil therapy after an inadequate response or intolerance to standard therapy (98% received combination therapy with corticosteroids plus thiopurines). Patients were recruited from 17 liver clinics via the Australian Liver Association Clinical Research Network. We reviewed records for baseline demographic features and characteristics of liver disease, initial therapy, mycophenolate mofetil indications, treatment outcome, and side effects. The primary outcome was biochemical remission, defined as levels of alanine and aspartate transferase and IgG level within the normal reference range, with or without normal liver histology within the first 2 years of treatment. Results The indication for mycophenolate mofetil therapy was non-response to treatment for 40% of cases and intolerance to therapy for 60%. Overall, 63 patients (60%) achieved biochemical remission following a median 12 weeks treatment with mycophenolate mofetil. The proportion of patients who achieved biochemical remission was similar between patients receiving mycophenolate mofetil for non-response to standard therapy (57%) and patients with intolerance to standard therapy (62%). However, a lower proportion of patients with cirrhosis achieved biochemical remission (47%) than patients without cirrhosis (6%) ( P = .07). Serious adverse events occurred in 3 patients (2.7%) including 1 death, and 10 patients (9.2%) discontinued mycophenolate mofetil because of adverse events. Conclusion In this retrospective study of patients with AIH who received mycophenolate mofetil as a rescue therapy, we found the drug to be well tolerated and moderately effective, inducing biochemical remission in 60% of subjects. Rates of response are lower and rates of infection are higher in patients with AIH and cirrhosis. Prospective studies of mycophenolate mofetil are warranted for this population. [ABSTRACT FROM AUTHOR]

Summary Multiple myeloma (MM) is a malignancy of plasma cells. Genome-wide association studies have shown that variation at 5q15 influences MM risk. Here, we have sought to decipher the causal variant at 5q15 and the mechanism by which it influences tumorigenesis. We show that rs6877329 G > C resides in a predicted enhancer element that physically interacts with the transcription start site of ELL2 . The rs6877329-C risk allele is associated with reduced enhancer activity and lowered ELL2 expression. Since ELL2 is critical to the B cell differentiation process, reduced ELL2 expression is consistent with inherited genetic variation contributing to arrest of plasma cell development, facilitating MM clonal expansion. These data provide evidence for a biological mechanism underlying a hereditary risk of MM at 5q15. [ABSTRACT FROM AUTHOR]

Summary Dysfunction in host immune responses and pathologic alterations in the gut microbiota, referred to as dysbiosis, can both contribute to the development of inflammatory bowel disease (IBD). However, it remains unclear how specific changes in host immunity or the microbiota cause disease. We previously demonstrated that the loss of the innate immune receptor NLRP6 in mice resulted in impaired production of interleukin-18 (IL-18) and increased susceptibility to epithelial-induced injury. Here, we show that NLRP6 is important for suppressing the development of spontaneous colitis in the Il10 −/− mice model of IBD and that NLRP6 deficiency results in the enrichment of Akkermansia muciniphila . A . muciniphila was sufficient for promoting intestinal inflammation in both specific-pathogen-free and germ-free Il10 −/− mice. Our results demonstrate that A . muciniphila can act as a pathobiont to promote colitis in a genetically susceptible host and that NLRP6 is a key regulator of its abundance. [ABSTRACT FROM AUTHOR]

Persistent infection with hepatitis C virus (HCV) is associated with an increased risk of hepatocellular carcinoma (HCC). Cancer typically develops in a setting of chronic hepatic inflammation and advanced fibrosis or cirrhosis, and such tissue represents a pre-neoplastic ‘cancer field’. However, not all persistent infections progress to HCC and a combination of viral and host immune factors likely contributes to carcinogenesis. HCV may disrupt cellular pathways involved in detecting and responding to DNA damage, potentially adding to the risk of cancer. Efforts to unravel how HCV promotes HCC are hindered by lack of a robust small animal model, but a better understanding of molecular mechanisms could identify novel biomarkers for early detection and allow for development of improved therapies. [ABSTRACT FROM AUTHOR]

The majority of disposable cups are made from paper plastic laminates (PPL) which consist of high quality cellulose fibre with a thin internal polyethylene coating. There are limited recycling options for PPLs and this has contributed to disposable cups becoming a high profile, problematic waste. In this work disposable cups have been shredded to form PPL flakes and these have been used to reinforce polypropylene to form novel paper plastic composites (PPCs). The PPL flakes and polypropylene were mixed, extruded, pelletised and injection moulded at low temperatures to prevent degradation of the cellulose fibres. The level of PPL flake addition and the use of a maleated polyolefin coupling agent to enhance interfacial adhesion have been investigated. Samples have been characterised using tensile testing, dynamic mechanical analysis (DMA) and thermogravimetric analysis. Use of a coupling agent allows composites containing 40 wt.% of PPL flakes to increase tensile strength of PP by 50% to 30 MPa. The Young modulus also increases from 1 to 2.5 GPa and the work to fracture increases by a factor of 5. The work demonstrates that PPL disposable cups have potential to be beneficially reused as reinforcement in novel polypropylene composites. [ABSTRACT FROM AUTHOR]

Abstract: Prior research indicates a relationship between psychopathy and schizophrenia, elucidating a specific trajectory toward violence. Recent research has suggested that this relationship exists at the nonclinical trait level of schizotypy; however, this finding has not been examined objectively. To explore this relationship using both subjective and objective measures, 54 undergraduates (50% male; mean age 20.41) who endorsed a wide range of schizotypy on the Schizotypal Personality Questionnaire (SPQ) completed a laboratory-based protocol. Participants viewed 15 pictures (five neutral, five threatening, and five of others in distress) from the International Affective Pictures System while electrodermal activity was recorded. As expected, all participants exhibited increased skin conductance levels (SCL) to threat and distress pictures compared to neutral pictures; however, no difference in SCL was found between threat and distress pictures. A unique relationship between psychopathy and schizotypy was found (i.e., schizotypy was related to higher Self-Centered Impulsivity and lower Fearless Dominance); however, schizotypy was related to increased SCL in response to emotional and neutral pictures. Although results do not support autonomic hyporesponsiveness often found in clinical psychopathy, a positive relationship was found between schizotypy and self-reported physical aggression. Findings highlight the need to examine other trajectories of violence within the schizophrenia spectrum disorders. [Copyright &y& Elsevier]

Abstract: Despite tremendous investments in information technology (IT), many technological interventions in organizations fail because employees do not fully accept and use IT. The present study explored how perceived organizational support and distributive justice affect employee reactions to new IT from a motivational point of view. Self-determination theory was used to understand how different motivational styles, varying in degree of self-determination, mediate the relationship of perceived organizational support and distributive justice with reactions to new IT. Results showed that perceived organizational support and distributive justice were associated with intrinsic and identified motivation to use the IT, but only POS was related to enjoyment and acceptance of the IT. Intrinsic and extrinsic motivation were both associated with IT usage, but IT usage was associated with enjoyment and acceptance only when people were intrinsically motivated. Intrinsic motivation also mediated the effects of POS on enjoyment and acceptance. Moreover, intrinsically motivated users were less likely to use a paper-based appointment booking alternative than those who were not. Implications for managing IT implementations are discussed. [Copyright &y& Elsevier]

Background: The combined effect of modifiable health factors on the risk of cardiovascular disease (CVD) mortality has not been well established. The objective of this study was to determine the association between 5 modifiable health factors in combination on the risk of CVD mortality in a sample of adult men. Methods: A cohort of 38,110 men (aged 20-84 years and of middle and upper socioeconomic strata) was followed over time until their date of death or December 31, 2003. A health profile score (unweighted and weighted) was developed based on cardiorespiratory fitness (CRF; moderate or high vs low), self-reported physical activity (active vs inactive), smoking status (not current vs current), alcohol consumption (1-14 drinks per week vs 0 or >14 drinks per week), and body mass index (BMI; 18.5-24.9 vs ≥25.0 kg/m2). Results: During 16.1 ± 8.4 years of follow-up and 613,571 man-years of exposure, there were 949 deaths from CVD. High CRF, normal BMI, being physically active, and not currently smoking were individually associated with reduced risk of CVD mortality after adjusting for confounders. When considered in combination, a minimum of 2 of 5 positive health factors reduced the risk of CVD mortality (hazard ratio = 0.67, 95% CI 0.49-0.91). The weighted score indicated that a combination of high CRF, not currently smoking, and normal BMI is of most clinical importance to CVD mortality (hazard ratio = 0.31, 95% CI 0.24-0.39). Conclusions: Exposure to increasing numbers of beneficial health factors in adulthood reduced the risk of CVD mortality in men, and multibehavioral prevention efforts in adulthood should be encouraged. [Copyright &y& Elsevier]

Abstract: Two-dimensional nuclear magnetic resonance relaxation correlation studies of cement pastes have been performed on a unilateral magnet, the Surface GARField. Through these measurements, the hydration process can be observed by monitoring the evolution of porosity. Characteristic relaxation time distributions have been observed in different cement pastes: fresh white cement, prehydrated white cement and ordinary Portland cement. The observed T 1/T 2 ratio in these cements has been shown to agree with expectations based on high field values. [Copyright &y& Elsevier]

Abstract: We present preliminary results of the first NMR T 1–T 2 two-dimensional relaxation correlation experiments performed using a one-sided NMR system in cement based materials. Two-dimensional correlation relaxometry has itself only recently been demonstrated in cement paste where it proved to be a particularly sensitive probe of pore-water dynamics providing direct information on exchange of water between the gel and capillary pore networks. Further to this we have observed differences in the structural development of a selection of cement pastes throughout the early stages of hydration and verified the theoretical frequency dependence of the ratio T 1 / T 2. When coupled with instrumentation developments in one-sided NMR magnets the way is opened to detailed, spatially resolved studies of the development of hydration and porosity in the surface layers (top 50mm) of cementitious materials. A new magnet, suitable for such applications, is discussed. [Copyright &y& Elsevier]

Understanding salient environmental determinants of pediatric sleep is essential for informing interventions and public health initiatives. Emerging evidence suggests that the neighborhood environment can impact pediatric sleep, but this evidence has not yet been systematically reviewed. We conducted a systematic review of the scientific literature on associations between neighborhood environments and sleep in young children (0-5 y), school-aged children (6-12 y) and adolescents (13-18 y). We reviewed 85 articles published between 2003 and 2020. The most commonly examined neighborhood exposure was low socioeconomic status (40 studies), which was associated with sleep outcomes in 58% of studies (primarily shorter sleep duration, later sleep timing, or obstructive sleep apnea). Evidence was stronger for neighborhood safety/crime/violence (21 studies), with 86% of studies reporting associations with sleep outcomes (primarily self- or caregiver-reported sleep problems). Fewer studies examined associations of neighborhood physical environment exposures, including noise (15 studies), the built environment (seven studies), and air pollution (six studies). Limitations of the current body of evidence include 1) limited examination of neighborhood exposures other than socioeconomic status or safety, 2) use of primarily cross-sectional observational study designs, 3) lack of objective sleep outcome assessment, and 4) limits of current exposure assessment methods. [ABSTRACT FROM AUTHOR]

Objective: To assess whether body mass index (BMI) provides a better assessment of measured adiposity at age 1 month compared with weight-for-length (WFL).Study Design: Participants were healthy term-born infants in the Infant Growth and Microbiome (n = 146) and the Baby Peas (n = 147) studies. Length, weight, and body composition by air displacement plethysmography were measured at 1 month. World Health Organization-based WFL and BMI z-scores were calculated. Within-cohort z-scores of percent fat-Z, fat mass-Z, fat mass/length2-Z, fat mass/length3-Z, fat-free mass-Z, and fat-free mass/length2-Z were calculated. Correlation and multiple linear regression (adjusted for birth weight) analyses tested the associations between body composition outcomes and BMI-Z vs WFL-Z. Quantile regression was used to test the stability of these associations across the distribution of body compositions.Results: The sample was 52% female and 56% African American. Accounting for birth weight, both BMI-Z and WFL-Z were strongly associated with fat mass-Z (coefficients 0.56 and 0.35, respectively), FM/L2-Z (0.73 and 0.51), and FM/L3-Z (0.79 and 0.58), with stronger associations for BMI-Z compared with WFL-Z (P < .05). Even after accounting statistically for birth weight, BMI-Z was persistently more strongly associated than WFL-Z with body composition outcomes across the distribution of body composition outcomes.Conclusions: We demonstrate in 2 distinct cohorts that BMI is a better indicator of adiposity in early infancy compared with WFL. Our findings support the preferred use of BMI for growth and nutritional status assessment in infancy. [ABSTRACT FROM AUTHOR]

Abstract Over the past two decades, a low frequency variant (rs1800012) within the first intron of the type I collagen alpha 1 (COLIA1) gene has been implicated in lower areal BMD (aBMD) and increased risk of osteoporotic fracture. This association is particularly strong in postmenopausal women, in whom net bone loss arises in the context of high bone turnover. High bone turnover also accompanies childhood linear growth; however, the role of rs1800012 in this stage of net bone accretion is less well understood. Thus, we assessed the association between rs1800012 and aBMD and bone mineral content (BMC) Z -scores for the 1/3 distal radius, lumbar spine, total hip, and femoral neck total body less head in the Bone Mineral Density in Childhood Study, a mixed-longitudinal cohort of children and adolescents (total n = 804 girls and 771 boys; n = 19 girls and 22 boys with the TT genotype). Mixed effects modeling, stratified by sex, was used to test for associations between rs1800012 and aBMD or BMC Z -scores and for pubertal stage interactions. Separately, SITAR growth modeling of aBMD and BMC in subjects with longitudinal data reduced the complex longitudinal bone accrual curves into three parameters representing a-size , b-timing , and c-velocity. We tested for differences in these three parameters by rs1800012 genotype using t -tests. Girls with the TT genotype had significantly lower aBMD and BMC Z -scores prior to puberty completion (e.g. spine aBMD-Z P-interaction = 1.0 × 10−6), but this association was attenuated post-puberty. SITAR models revealed that TT girls began pubertal bone accrual later (b-timing ; e.g. total hip BMC, P = 0.03). BMC and aBMD Z-scores also increased across puberty in TT homozygous boys. Our data, along with previous findings in post-menopausal women, suggest that rs1800012 principally affects female bone density during periods of high turnover. Insights into the genetics of bone gain and loss may be masked during the relatively quiescent state in mid-adulthood, and discovery efforts should focus on early and late life. Highlights • Sp1 COL1A1 variant rs1800012 associates with pediatric bone density. • Using longitudinal data, we found that this variant delays bone accrual in girls. • Mirrors postmenopausal reports, suggesting impact in high bone turnover states • Genetic discovery efforts should focus on variants acting during bone gain and loss. [ABSTRACT FROM AUTHOR]

We previously reported significant gains in pQCT measures of tibia trabecular bone mineral density (BMD) and cortical structure following completion of therapy in children and adolescents with acute lymphoblastic leukemia (ALL). The objective of this study was to examine changes in DXA measures used in clinical practice and expressed as Z-scores using robust national reference data. Children and adolescents, ages 5 to 18 years were enrolled within 2 (median 0.8) years of completing ALL therapy. DXA total-body less-head bone mineral content (TBLH-BMC), and spine, total hip, femoral neck, and 1/3rd radius areal BMD (aBMD) were assessed in 45 participants at enrollment and 12-months later. Linear regression models examined correlates of changes in DXA Z-scores. Changes in DXA outcomes were compared to changes in tibia pQCT trabecular and cortical volumetric BMD (vBMD) and cortical area. At enrollment, DXA TBLH-BMC, spine and radius aBMD Z-scores were not significantly reduced in ALL survivors; however, total hip [median −0.74 (IQ range −1.51 to −0.04)] and femoral neck [−0.51 (−1.24 to 0.14)] aBMD Z-scores were lower (both p < 0.01) compared to reference data. DXA Z-scores at all skeletal sites increased over 12 months. Despite improvement, total hip Z-score remained lower at −0.55 (−1.05 to 0.18). The increases in TBLH-BMC, total hip and femoral neck aBMD Z-scores were more pronounced in those enrolled within 6 months of completing ALL therapy, compared to those enrolled at >6 months. Gains in TBLH-BMC, total hip, femoral neck and radius aBMD Z-scores were significantly associated with gains in tibia cortical area Z-scores (R = 0.56 to 0.67, p ≤ 0.001). Changes in TBLH and proximal femur sites were associated with gains in trabecular vBMD Z-scores (R = 0.37 to 0.40; p ≤ 0.01); these associations were not significant when adjusted for gains in cortical area. In summary, gains in DXA measures were most pronounced in total hip and femoral neck following ALL therapy. The gains in all DXA measures, with the exception of lumbar spine, reflected gains in cortical area. Overall, ALL survivors demonstrate skeletal recovery following completion of therapy; a small sub-group continue to demonstrate deficits and benefit from continued observation to ensure improvement over time. [ABSTRACT FROM AUTHOR]

[Display omitted] Built and natural environments may provide opportunities for physical activity. However, studies are limited by primarily using residential addresses to define exposure and self-report to measure physical activity. We quantified associations between global positioning systems (GPS)-based activity space measures of environmental exposure and accelerometer-based physical activity. Using a nationwide sample of working female adults (N = 354), we obtained seven days of GPS and accelerometry data. We created Daily Path Area activity spaces using GPS data and linked these activity spaces to spatial datasets on walkability (EPA Smart Location Database at the Census block group level) and greenness (satellite vegetation at 250 m resolution). We utilized generalized additive models to examine nonlinear associations between activity space exposures and accelerometer-derived physical activity outcomes adjusted for demographic characteristics, socioeconomic factors, and self-rated health. Higher activity space walkability was associated with higher levels of moderate-vigorous physical activity, and higher activity space greenness was associated with greater numbers of steps per week. No strong relationships were observed for sedentary behavior or light physical activity. Highest levels of moderate-vigorous physical activity were observed for participants with both high walkability and high greenness in their activity spaces. This study contributes evidence that higher levels of physical activity occur in environments with more dense, diverse, and well-connected built environments, and with higher amounts of vegetation. These data suggest that urban planners, landscape architects, and policy makers should implement and evaluate environmental interventions to encourage higher levels of physical activity. [ABSTRACT FROM AUTHOR]

Abstract: Titan’s polar regions, and its hydrocarbon lakes in particular, are of interest for future exploration. The polar conditions have considerable seasonal variation and are distinct from the equatorial environment experienced by Huygens. Thus specific environmental models are required for these regions. This paper, informed by Cassini and groundbased observations and four independent Global Circulation Models (GCMs), summarizes northern summer polar conditions (specifically, regions north of 65°N, during the 2023–2024 period, or solar longitude L s ∼150o–170°) and presents a simple analytical formulation of expected, minimum and maximum winds as a function of altitude to aid spacecraft and instrument design for future exploration, with particular reference to the descent dispersions of the Titan Mare Explorer (TiME) mission concept presently under development. We also consider winds on the surface, noting that these (of relevance for impact conditions, for waves, and for wind-driven drift of a floating capsule) are weaker than those in the lowest cell in most GCMs: some previously-reported estimates of ‘surface’ wind speeds (actually at 90–500m altitude) should be reduced by 20–35% to refer to the standard 10m ‘anemometer height’ applicable for surface phenomena. A Weibull distribution with scale speed C=0.4m/s and shape parameter k=2.0 embraces the GCM-predicted surface wind speeds. [Copyright &y& Elsevier]

Abstract: Single-sided magnets give hope that Nuclear Magnetic Resonance (NMR) might in future be used for in situ characterisation of hydration and water transport in the surface layers of concrete slabs. Towards that end, a portable NMR-MOUSE (MObile Universal Surface Explorer) has been used to follow the hydration of gypsum based plaster, a Portland cement paste and concrete mortar. The results compare favourably to those obtained using a standard laboratory bench-top spectrometer. Further, stray field imaging (STRAFI) based methods have been used with embedded NMR detector coils to study water transport across a mortar/topping interface. The measured signal amplitudes are found to correlate with varying sample conditions. [Copyright &y& Elsevier]