Harsh Parenting and Food Insecurity in Adolescence: The Association with Emerging Adult Obesity

In the U.S., as of 2012, more than one in three youth were overweight or obese [1]. This is a critical health issue, as being overweight or obese (OW/OB) during adolescence increases the risk of adulthood diseases, including but not limited to cardiovascular and heart disease, diabetes, stroke, cancer, and osteoarthritis [2]. Understanding the pathways to obesity is critical for implementation of successful prevention and intervention programs. One of the pathways leading to OW/OB is through social and economic experiences within the family

The Effect of a Femoral Fracture Sustained before Skeletal Maturity on Bone Mineral Density: A Long-Term Follow-Up Study

Peer reviewe

Self-Assembly of \u3cem\u3eEscherichia coli\u3c/em\u3e MutL and Its Complexes with DNA

The Escherichia coli MutL protein regulates the activity of several enzymes, including MutS, MutH, and UvrD, during methyl-directed mismatch repair of DNA. We have investigated the self-association properties of MutL and its binding to DNA using analytical sedimentation velocity and equilibrium. Self-association of MutL is quite sensitive to solution conditions. At 25 °C in Tris at pH 8.3, MutL assembles into a heterogeneous mixture of large multimers. In the presence of potassium phosphate at pH 7.4, MutL forms primarily stable dimers, with the higher-order assembly states suppressed. The weight-average sedimentation coefficient of the MutL dimer in this buffer (s̅20,w) is equal to 5.20 ± 0.08 S, suggesting a highly asymmetric dimer (f/fo = 1.58 ± 0.02). Upon binding the nonhydrolyzable ATP analogue, AMPPNP/Mg2+, the MutL dimer becomes more compact (s̅20,w = 5.71 ± 0.08 S; f/fo = 1.45 ± 0.02), probably reflecting reorganization of the N-terminal ATPase domains. A MutL dimer binds to an 18 bp duplex with a 3′-(dT20) single-stranded flanking region, with apparent affinity in the micromolar range. AMPPNP binding to MutL increases its affinity for DNA by a factor of ∼10. These results indicate that the presence of phosphate minimizes further MutL oligomerization beyond a dimer and that differences in solution conditions likely explain apparent discrepancies in previous studies of MutL assembly

Allosteric effects of E. coli SSB and RecR proteins on RecO protein binding to DNA

Escherichia coli single stranded (ss) DNA binding protein (SSB) plays essential roles in DNA maintenance. It binds ssDNA with high affinity through its N-terminal DNA binding core and recruits at least 17 different SSB interacting proteins (SIPs) that are involved in DNA replication, recombination, and repair via its nine amino acid acidic tip (SSB-Ct). E. coli RecO, a SIP, is an essential recombination mediator protein in the RecF pathway of DNA repair that binds ssDNA and forms a complex with E. coli RecR protein. Here, we report ssDNA binding studies of RecO and the effects of a 15 amino acid peptide containing the SSB-Ct monitored by light scattering, confocal microscope imaging, and analytical ultracentrifugation (AUC). We find that one RecO monomer can bind the oligodeoxythymidylate, (dT)15, while two RecO monomers can bind (dT)35 in the presence of the SSB-Ct peptide. When RecO is in molar excess over ssDNA, large RecO-ssDNA aggregates occur that form with higher propensity on ssDNA of increasing length. Binding of RecO to the SSB-Ct peptide inhibits RecO-ssDNA aggregation. RecOR complexes can bind ssDNA via RecO, but aggregation is suppressed even in the absence of the SSB-Ct peptide, demonstrating an allosteric effect of RecR on RecO binding to ssDNA. Under conditions where RecO binds ssDNA but does not form aggregates, SSB-Ct binding enhances the affinity of RecO for ssDNA. For RecOR complexes bound to ssDNA, we also observe a shift in RecOR complex equilibrium towards a RecR4O complex upon binding SSB-Ct. These results suggest a mechanism by which SSB recruits RecOR to facilitate loading of RecA onto ssDNA gaps

Assessing the importance of a self-generated detachment process in river biofilm models

1. Epilithic biofilm biomass was measured for 14 months in two sites, located up- and downstream of the city of Toulouse in the Garonne River (south-west France). Periodical sampling provided a biomass data set to compare with simulations from the model of Uehlinger, Bürher and Reichert (1996: Freshwater Biology, 36, 249–263.), in order to evaluate the impact of hydraulic disturbance. 2. Despite differences in application conditions (e.g. river size, discharge, frequency of disturbance), the base equation satisfactorily predicted biomass between low and high water periods of the year, suggesting that the flood disturbance regime may be considered a universal mechanism controlling periphyton biomass. 3. However modelling gave no agreement with biomass dynamics during the 7-month long low water period that the river experienced. The influence of other biomass-regulating factors (temperature, light and soluble reactive phosphorus) on temporal biomass dynamics was weak. 4. Implementing a supplementary mechanism corresponding to a temperature-dependent self-generated loss because of heterotrophic processes allowed us to accurately reproduce the observed pattern: a succession of two peaks. This case study suggests that during typical summer low water periods (flow stability and favourable temperature) river biofilm modelling requires self-generated detachment to be considered

Four problems with global carbon markets: a critical review

This article offers a critique of global carbon markets and trading, with a special focus on the Clean Development Mechanism of the Kyoto Protocol. It explores problems with the use of tradable permits to address climate change revolving around four areas: homogeneity, justice, gaming, and information. Homogeneity problems arise from the non-linear nature of climate change and sensitivity of emissions, which complicate attempts to calculate carbon offsets. Justice problems involve issues of dependency and the concentration of wealth among the rich, meaning carbon trading often counteracts attempts to reduce poverty. Gaming problems include pressures to promote high-volume, least-cost projects and the consequences of emissions leakage. Information problems encompass transaction costs related to carbon trading and market participation and the comparatively weak institutional capacity of project evaluators

Stress reaction in the carpal bones caused by breakdancing

Stress reactions in the bones of the lower extremities are a common finding on magnetic resonance (MR) imaging. The primary finding in the bone marrow is nonspecific edema without any visible fracture line that may even mimic tumor or infection. Continuing stress may eventually lead to a stress fracture. We present the case of a stress reaction related to breakdancing in a less typical localization, in the triquetral bone in the wrist.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47934/1/10140_2003_Article_293.pd