The biomechanical role of the chondrocranium and sutures in a lizard cranium

The role of soft tissues in skull biomechanics remains poorly understood. Not least, the chondrocranium, the portion of the braincase which persists as cartilage with varying degrees of mineralization. It also remains commonplace to overlook the biomechanical role of sutures despite evidence that they alter strain distribution. Here, we examine the role of both the sutures and the chondrocranium in the South American tegu lizard Salvator merianae. We use multi-body dynamics analysis (MDA) to provide realistic loading conditions for anterior and posterior unilateral biting and a detailed finite element model to examine strain magnitude and distribution. We find that strains within the chondrocraniumare greatest during anterior biting and are primarily tensile; also that strain within the cranium is not greatly reduced by the presence of the chondrocraniumunless it is given the same material properties as bone. This result contradicts previous suggestions that the anterior portion (the nasal septum) acts as a supporting structure. Inclusion of sutures to the cranium model not only increases overall strain magnitudes but also leads to a more complex distribution of tension and compression rather than that of a beam under sagittal bending

The long-term impact of folic acid in pregnancy on offspring DNA methylation : follow-up of the Aberdeen folic acid supplementation trial (AFAST)

Funding This work was supported by the NIHR Bristol Biomedical Research Centre at the University Hospitals Bristol NHS Foundation Trust and the University of Bristol. The views expressed in this publication are those of the authors and not necessarily those of the NHS, the National Institute for Health Research or the Department of Health. R.C.R., G.C.S., N.K., T.G., G.D.S. and C.L.R. work in a unit that receives funds from the University of Bristol and the UK Medical Research Council (MC_UU_12013/1, MC_UU_12013/2 and MC_UU_12013/8). This work was also supported by CRUK (grant number C18281/A19169) and the ESRC (grant number ES/N000498/1). C.M.T. is supported by a Wellcome Trust Career Re-entry Fellowship (grant number 104077/Z/14/Z).Peer reviewedPublisher PD

Clean, cheap, and just : sustainability values expressed in Austin’s residential solar rebate policies and by Austin residents

Residential solar panels have great promise to reduce dependence on energy from carbon-emitting sources. However, the high cost of solar panels puts the technology out of reach for many residents and compels utilities to provide subsidies for their purchase. This master’s thesis investigates the manifestation of economic, environmental, and social equity interests in Austin Energy’s residential solar rebate program through the perspective of the utility and of the residents of Austin, Texas. I situate the thesis in the context of climate change, local inequality, and the externalities of conventional energy choices. I then evaluate the expression of sustainability values embedded within solar technology policy and implementation through three areas of inquiry: an examination of residential solar incentives, including interviews with utility personnel at Austin Energy and CPS Energy in San Antonio; an analysis of survey data indicating resident perceptions of solar technology; and a comparison of the energy used by solar panel owners and non-owners. I found that, as hypothesized, economic interests dominate a more moderate showing of environmental values and a smattering of social issues in terms of policy design and residential perceptions. However, energy use data showed that solar panels do significantly reduce household energy consumption drawn from the grid, including during times of peak demand. Research findings indicate a need for a better connection of social interests with economic and environmental values when it comes to residential solar technology policy and adoption.Community and Regional PlanningSustainable Desig

Impact assessment for the life cycle assessment of a manufacturedproduct [sic] using a chemical ranking and scoring system

In this study an algorithm for a chemical ranking and scoring system is developed and applied to the impact assessment phase of a product life cycle assessment. The algorithm is a modification of a previous model developed by researchers at the University of Tennessee and includes the toxicological endpoint of the no observable adverse effect level (NOAEL). The chemical ranking and scoring system is used to assign a numerical value which is a measure of the potential hazard associated with a specific chemical release from a manufacturing process. These hazard values are calculated based on physical and chemical properties, the quantity released, and standard toxicological endpoints. The summation of these hazard values are used to compare information from a life cycle assessment for two identified phases of the manufacture of a plastic material to determine the phase which has the greatest potential for adverse environmental effects. From the algorithm in this study the first phase of production of a high density polyethylene plastic is determined to be 9159 and the second phase of production is determined to be 5418. Therefore, the first production phase is identified as having a greater potential environmental impact than the second production phase. These values are to be used for relative ranking comparison only and cannot be divided into each other to make a mathematical statement about degree of hazard

Clostridium difficile ribotype diversity at six health care institutions in the United States

Capillary-based PCR ribotyping was used to quantify the presence/absence and relative abundance of 98 Clostridium difficile ribotypes from clinical cases of disease at health care institutions in six states of the United States. Regionally important ribotypes were identified, and institutions in close proximity did not necessarily share more ribotype diversity than institutions that were farther apart

Alginate inhibits iron absorption from ferrous gluconate in a randomized controlled trial and reduces iron uptake into Caco-2 cells

Previous in vitro results indicated that alginate beads might be a useful vehicle for food iron fortification. A human study was undertaken to test the hypothesis that alginate enhances iron absorption. A randomised, single blinded, cross-over trial was carried out in which iron absorption was measured from serum iron appearance after a test meal. Overnight-fasted volunteers (n=15) were given a test meal of 200g cola-flavoured jelly plus 21 mg iron as ferrous gluconate, either in alginate beads mixed into the jelly or in a capsule. Iron absorption was lower from the alginate beads than from ferrous gluconate (8.5% and 12.6% respectively, p=0.003). Sub-group B (n=9) consumed the test meals together with 600 mg calcium to determine whether alginate modified the inhibitory effect of calcium. Calcium reduced iron absorption from ferrous gluconate by 51%, from 11.5% to 5.6% (p=0.014), and from alginate beads by 37%, from 8.3% to 5.2% (p=0.009). In vitro studies using Caco-2 cells were designed to explore the reasons for the difference between the previous in vitro findings and the human study; confirmed the inhibitory effect of alginate. Beads similar to those used in the human study were subjected to simulated gastrointestinal digestion, with and without cola jelly, and the digestate applied to Caco-2 cells. Both alginate and cola jelly significantly reduced iron uptake into the cells, by 34% (p=0.009) and 35% (p=0.003) respectively. The combination of cola jelly and calcium produced a very low ferritin response, 16.5% (p<0.001) of that observed with ferrous gluconate alone. The results of these studies demonstrate that alginate beads are not a useful delivery system for soluble salts of iron for the purpose of food fortification

DNA methylation and body mass index:investigating identified methylation sites at HIF3A in a causal framework

Multiple differentially methylated sites and regions associated with adiposity have now been identified in large-scale cross-sectional studies. We tested for replication of associations between previously identified CpG sites at HIF3A and adiposity in ∼1,000 mother-offspring pairs from the Avon Longitudinal Study of Parents and Children (ALSPAC). Availability of methylation and adiposity measures at multiple time points, as well as genetic data, allowed us to assess the temporal associations between adiposity and methylation and to make inferences regarding causality and directionality. Overall, our results were discordant with those expected if HIF3A methylation has a causal effect on BMI and provided more evidence for causality in the reverse direction (i.e., an effect of BMI on HIF3A methylation). These results are based on robust evidence from longitudinal analyses and were also partially supported by Mendelian randomization analysis, although this latter analysis was underpowered to detect a causal effect of BMI on HIF3A methylation. Our results also highlight an apparent long-lasting intergenerational influence of maternal BMI on offspring methylation at this locus, which may confound associations between own adiposity and HIF3A methylation. Further work is required to replicate and uncover the mechanisms underlying the direct and intergenerational effect of adiposity on DNA methylation.Rebecca C. Richmond, Gemma C. Sharp, Mary E. Ward, Abigail Fraser, Oliver Lyttleton, Wendy L. McArdle, Susan M. Ring, Tom R. Gaunt, Debbie A. Lawlor, George Davey Smith, and Caroline L. Relto

Focal concerns, race & sentencing of female drug offenders

The increase of female incarceration in the United States over the past decade has be­come a cause for concern. This increase differs across racial groups, with black women disproportionately more likely to be incarcerated and to receive longer sentences. In the current study, we modify the ''focal concerns" perspective developed by Steffensmeier et al. (1998) to explain the high incarceration rate for black males. We hypothesize that the sentencing disparity between black women and white women is at least partially due to perceived violations of traditional gender norms, an "evil woman" explanation. To test this, we examined the effects of legal and extralegal variables on sentence lengths in a sample of incarcerated drug offenders in Oklahoma. Legal factors such as prior incar­ceration and related factors such as employment were predictors of sentence lengths for white women, but not for black women. Instead, self-reported use of crack cocaine was associated with longer sentences for the black offenders despite the fact that white of­fenders were almost as likely to report use of crack. For both groups, trial by jury was associated with longer sentences, but more so for black women, providing some support for the "evil woman" focal concern

Prenatal and early life influences on epigenetic age in children:a study of mother-offspring pairs from two cohort studies

DNA methylation-based biomarkers of aging are highly correlated with actual age. Departures of methylation-estimated age from actual age can be used to define epigenetic measures of child development or age acceleration (AA) in adults. Very little is known about genetic or environmental determinants of these epigenetic measures of aging. We obtained DNA methylation profiles using Infinium HumanMethylation450 BeadChips across five time-points in 1018 mother-child pairs from the Avon Longitudinal Study of Parents and Children. Using the Horvath age estimation method, we calculated epigenetic age for these samples. AA was defined as the residuals from regressing epigenetic age on actual age. AA was tested for associations with cross-sectional clinical variables in children. We identified associations between AA and sex, birth weight, birth by caesarean section and several maternal characteristics in pregnancy, namely smoking, weight, BMI, selenium and cholesterol level. Offspring of non-drinkers had higher AA on average but this difference appeared to resolve during childhood. The associations between sex, birth weight and AA found in ARIES were replicated in an independent cohort (GOYA). In children, epigenetic AA measures are associated with several clinically relevant variables, and early life exposures appear to be associated with changes in AA during adolescence. Further research into epigenetic aging, including the use of causal inference methods, is required to better our understanding of aging