Effect of Irradiation on Lipid Oxidation and Off-flavor Development in Cooked Pork Products with Different Fatty Acids and Packaging

Irradiated samples had higher thiobarbituric acid reactive substances (TBARS) than nonirradiated at day 0 but the difference disappeared during storage in both packaging types. Storage increased the production of volatiles and changed the composition of volatiles only in aerobic-packaged sausage. Irradiation and the fatty acid composition had significant effects on lipid oxidation, volatile production, and sensory characteristics of cooked pork sausages during storage but that oxygen availability had a stronger effect than irradiation and fatty acid composition. Storage increased the production of volatiles and changed the composition of volatiles only in aerobicpackaged sausage. Among the volatile components, 1-heptene and 1-nonene were influenced most by irradiation dose, and aldehydes by packaging type. The TBARS values and volatiles of vacuum-packaged irradiated cooked sausage had very low correlation. The TBARS, however, had very high correlation with the amount of aldehydes and total volatiles, and ketones and alcohols with long retention times in aerobic-packaged pork sausage. The low correlations of irradiation-dependent volatiles (e.g., 1-heptene and 1-nonene) with TBARS values regardless of packaging and storage conditions indicated that volatile compounds responsible for irradiation odor were different from those of lipid oxidation odor in cooked pork sausages. Irradiation of cooked pork sausage, especially at 4.5 kGy and in aerobic packaging, may result in some diminution of typical meaty aromas and increases in an odor described by the panelists in this study as like wet wool or wet animal hair. The training and controlled test situation used in this study may result in greater discrimination in the panel than would exist in most consumers. Whether the changes caused by irradiation would be noticed by consumers or reduce the acceptability of the product to consumers was not addressed in this study. The data obtained suggest that TBARS values may not be useful in predicting the odor changes in cooked irradiated meat products

Physical activity, sedentary behaviour, and mental health in children: findings from the UK Millennium Cohort Study

Background: Research has shown that physical activity (PA) may improve mental health. This thesis explores the association between PA and mental health in UK Millennium Cohort Study children. The role of environmental characteristics, type and intensity of PA, and direction of causality will be investigated. Methods: Accelerometer data were collected at age 7 and reported PA and sedentary behaviour data were collected at ages 5, 7, and 11. Mental health was measured using the Strengths and Difficulties Questionnaire (SDQ). Models were run separately by gender. Associations between minutes of sedentary, light PA, moderate-to-vigorous (MVPA) and SDQ were estimated using multiple linear regression, adjusting for multiple confounders (n=6,153). Between-individual and -ward variances were estimated using multilevel models. Environmental effects were explored using green space, deprivation, and urbanicity variables. Associations between reported PA and sedentary behaviours, and SDQ were estimated using three-wave, cross-lagged panel models. Results: In fully adjusted models, increased light PA and MVPA for boys, and light PA only for girls and less sedentary time, was associated with fewer peer problems. MVPA was positively associated with conduct problems in boys. Increased PA and less sedentary time were associated with more hyperactive symptoms. These effects were observed in both single- and multilevel models. No evidence of green space effects as confounder or moderator were observed in multilevel models. Intraclass correlation coefficients ranged from 4.5% (hyperactivity in girls) to 9.2% (peer problems in girls) in fully adjusted models. In cross-lagged models, sports participation improved emotional and peer problems, and total difficulties. Less television was associated with fewer peer and conduct problems, hyperactive symptoms, and total difficulties in boys. Active commuting and electronic gaming were not found to predict mental health outcomes. Conclusions: Whether PA improves mental health depends on the intensity and type of PA or sedentary behaviour, SDQ outcome, gender, and timing of exposure

Volatile Production and Lipid Oxidation of Irradiated Cooked Sausage with Different Packaging

Irradiation dose had a significant effect on the production of volatiles in both vacuum- and aerobic-packaged cooked pork sausage, but its effect on the thiobarbituric acid reactive substances (TBARS) values was minor. Storage increased the production of volatiles and changed the composition of volatiles only in aerobic-packaged sausage. Among the volatile components, 1-heptene and 1-nonene were influenced most by irradiation dose, and aldehydes by packaging type. The TBARS values and volatiles of vacuum-packaged irradiated cooked sausage had very low correlation.The TBARS, however, had very high correlation with the amount of aldehydes and total volatiles, and ketones and alcohols with long retention times in aerobic-packaged pork sausage. Heptene and 1-nonene could be used as indicators for irradiation, and propanal, pentanal, and hexanal for the oxygen-dependent changes of cooked meat. The results indicated that irradiation had some effect on lipid oxidation of cooked pork sausages, especially with aerobic packaging, but oxygen availability (packaging) to meat during storage had much stronger impact. The low correlations of irradiation-dependent volatiles (e.g., 1-heptene and 1-nonene) with TBARS values regardless of packaging and storage conditions indicated that volatile compounds responsible for irradiation odor were different from those of lipid oxidation odor in cooked pork sausages

Associations between objectively measured physical activity and later mental health outcomes in children: findings from the UK Millennium Cohort Study.

BACKGROUND: The beneficial effect of physical activity (PA) on mental health in adults is well established, but less is known about this relationship in children. We examine associations between objectively measured sedentary time, PA and mental health in 11-year-olds from the UK Millennium Cohort Study (MCS). METHODS: Longitudinal data from MCS sweeps 4 (age 7) and 5 (age 11) were used (n=6153). Accelerometer data were collected at MCS4, and mental health was measured at MCS4 and MCS5 using subscales (peer, emotional, conduct, hyperactivity) of the Strengths and Difficulties Questionnaire (SDQ). Associations between mean daily PA minutes at different intensities (sedentary, light, moderate-to-vigorous) at MCS4 and SDQ outcomes at MCS5 (score range 0-10) were estimated using multiple linear regression models, adjusting for SDQ at MCS4 and individual and family characteristics, and stratified by gender. RESULTS: In fully adjusted models, increased PA at MCS4 was associated with fewer peer problems in boys and girls at MCS5. For each additional 15 min in moderate-to-vigorous physical activity (MVPA), peer problems decreased -0.077 points (95% CI -0.133 to -0.022) in boys. For girls, light PA was associated with decreased peer problems (-0.071 points/30 min, 95% CI -0.130 to -0.013). Greater sedentary time was associated with more peer problems and fewer hyperactivity symptoms in boys and girls. Increased MVPA was associated with more conduct and hyperactivity problems in boys and more hyperactivity in girls. CONCLUSIONS: Increased sedentary time is associated with more peer problems in children, and PA, generally, is beneficial for peer relations in children aged 11

Allosteric “beta-blocker” isolated from a DNA-encoded small molecule library

The present study reports the discovery of a small-molecule negative allosteric modulator for the β2-adrenergic receptor (β2AR) via in vitro affinity-based iterative selection of highly diverse DNA-encoded small-molecule libraries. Characterization of the compound demonstrates its selectivity for the β2AR and that it negatively modulates a wide range of receptor functions. More importantly, our findings establish a generally applicable, proof-of-concept strategy for screening DNA-encoded small-molecule libraries against purified G-protein–coupled receptors (GPCRs), which holds great potential for discovering therapeutic molecules

Ascl1 (Mash1) Defines Cells with Long-Term Neurogenic Potential in Subgranular and Subventricular Zones in Adult Mouse Brain

Ascl1 (Mash1) is a bHLH transcription factor essential for neural differentiation during embryogenesis but its role in adult neurogenesis is less clear. Here we show that in the adult brain Ascl1 is dynamically expressed during neurogenesis in the dentate gyrus subgranular zone (SGZ) and more rostral subventricular zone (SVZ). Specifically, we find Ascl1 levels low in SGZ Type-1 cells and SVZ B cells but increasing as the cells transition to intermediate progenitor stages. In vivo genetic lineage tracing with a tamoxifen (TAM) inducible Ascl1CreERT2 knock-in mouse strain shows that Ascl1 lineage cells continuously generate new neurons over extended periods of time. There is a regionally-specific difference in neuron generation, with mice given TAM at postnatal day 50 showing new dentate gyrus neurons through 30 days post-TAM, but showing new olfactory bulb neurons even 180 days post-TAM. These results show that Ascl1 is not restricted to transit amplifying populations but is also found in a subset of neural stem cells with long-term neurogenic potential in the adult brain

Cancer-Associated Fibroblasts Induce a Collagen Cross-link Switch in Tumor Stroma

Intratumoral collagen cross-links heighten stromal stiffness and stimulate tumor cell invasion, but it is unclear how collagen cross-linking is regulated in epithelial tumors. To address this question, we used KrasLA1 mice, which develop lung adenocarcinomas from somatic activation of a KrasG12D allele. The lung tumors in KrasLA1 mice were highly fibrotic and contained cancer-associated fibroblasts (CAFs) that produced collagen and generated stiffness in collagen gels. In xenograft tumors generated by injection of wild-type mice with lung adenocarcinoma cells alone or in combination with CAFs, the total concentration of collagen cross-links was the same in tumors generated with or without CAFs, but co-injected tumors had higher hydroxylysine aldehyde-derived collagen cross-links (HLCCs) and lower lysine-aldehyde-derived collagen cross-links (LCCs). Therefore, we postulated that an LCC-to-HLCC switch induced by CAFs promotes the migratory and invasive properties of lung adenocarcinoma cells. To test this hypothesis, we created co-culture models in which CAFs are positioned interstitially or peripherally in tumor cell aggregates, mimicking distinct spatial orientations of CAFs in human lung cancer. In both contexts, CAFs enhanced the invasive properties of tumor cells in 3-dimensional (3D) collagen gels. Tumor cell aggregates that attached to CAF networks on a Matrigel surface dissociated and migrated on the networks. Lysyl hydroxylase 2 (PLOD2/LH2), which drives HLCC formation, was expressed in CAFs, and LH2 depletion abrogated the ability of CAFs to promote tumor cell invasion and migration

Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas

This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin