Coordination of opposing sex-specific and core muscle groups regulates male tail posture during Caenorhabditis elegans male mating behavior

Background To survive and reproduce, animals must be able to modify their motor behavior in response to changes in the environment. We studied a complex behavior of Caenorhabditis elegans, male mating behavior, which provided a model for understanding motor behaviors at the genetic, molecular as well as circuit level. C. elegans male mating behavior consists of a series of six sub-steps: response to contact, backing, turning, vulva location, spicule insertion, and sperm transfer. The male tail contains most of the sensory structures required for mating, in addition to the copulatory structures, and thus to carry out the steps of mating behavior, the male must keep his tail in contact with the hermaphrodite. However, because the hermaphrodite does not play an active role in mating and continues moving, the male must modify his tail posture to maintain contact. We provide a better understanding of the molecular and neuro-muscular pathways that regulate male tail posture during mating. Results Genetic and laser ablation analysis, in conjunction with behavioral assays were used to determine neurotransmitters, receptors, neurons and muscles required for the regulation of male tail posture. We showed that proper male tail posture is maintained by the coordinated activity of opposing muscle groups that curl the tail ventrally and dorsally. Specifically, acetylcholine regulates both ventral and dorsal curling of the male tail, partially through anthelmintic levamisole-sensitive, nicotinic receptor subunits. Male-specific muscles are required for acetylcholine-driven ventral curling of the male tail but dorsal curling requires the dorsal body wall muscles shared by males and hermaphrodites. Gamma-aminobutyric acid activity is required for both dorsal and ventral acetylcholine-induced curling of the male tail and an inhibitory gamma-aminobutyric acid receptor, UNC-49, prevents over-curling of the male tail during mating, suggesting that cross-inhibition of muscle groups helps maintain proper tail posture. Conclusion Our results demonstrated that coordination of opposing sex-specific and core muscle groups, through the activity of multiple neurotransmitters, is required for regulation of male tail posture during mating. We have provided a simple model for regulation of male tail posture that provides a foundation for studies of how genes, molecular pathways, and neural circuits contribute to sensory regulation of this motor behavior

Integrating a family-focused approach into child obesity prevention: Rationale and design for the My Parenting SOS study randomized control trial

<p>Abstract</p> <p>Background</p> <p>More than 20% of US children ages 2-5 yrs are classified as overweight or obese. Parents greatly influence the behaviors their children adopt, including those which impact weight (e.g., diet and physical activity). Unfortunately, parents often fail to recognize the risk for excess weight gain in young children, and may not be motivated to modify behavior. Research is needed to explore intervention strategies that engage families with young children and motivate parents to adopt behaviors that will foster healthy weight development.</p> <p>Methods</p> <p>This study tests the efficacy of the 35-week My Parenting SOS intervention. The intervention consists of 12 sessions: initial sessions focus on general parenting skills (stress management, effective parenting styles, child behavior management, coparenting, and time management) and later sessions apply these skills to promote healthier eating and physical activity habits. The primary outcome is change in child percent body fat. Secondary measures assess parent and child dietary intake (three 24-hr recalls) and physical activity (accelerometry), general parenting style and practices, nutrition- and activity-related parenting practices, and parent motivation to adopt healthier practices.</p> <p>Discussion</p> <p>Testing of these new approaches contributes to our understanding of how general and weight-specific parenting practices influence child weight, and whether or not they can be changed to promote healthy weight trajectories.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00998348">NCT00998348</a></p

Recent increase of surface particulate matter concentrations in the Seoul Metropolitan Area, Korea

Recent changes of surface particulate matter (PM) concentration in the Seoul Metropolitan Area (SMA), South Korea, are puzzling. The long-term trend of surface PM concentration in the SMA declined in the 2000s, but since 2012 its concentrations have tended to incline, which is coincident with frequent severe hazes in South Korea. This increase puts the Korean government&apos;s emission reduction efforts in jeopardy. This study reports that interannual variation of surface PM concentration in South Korea is closely linked with the interannual variations of wind speed. A 12-year (2004-2015) regional air quality simulation was conducted over East Asia (27-km) and over South Korea (9-km) to assess the impact of meteorology under constant anthropogenic emissions. Simulated PM concentrations show a strong negative correlation (i.e. R = -0.86) with regional wind speed, implying that reduced regional ventilation is likely associated with more stagnant conditions that cause severe pollutant episodes in South Korea. We conclude that the current PM concentration trend in South Korea is a combination of long-term decline by emission control efforts and short-term fluctuation of regional wind speed interannual variability. When the meteorology-driven variations are removed, PM concentrations in South Korea have declined continuously even after 2012

Hypoxia in prostate cancer: Correlation of bold-MRI with pimonidazole immunohistochemistry - Initial observations

Purpose: To investigate the ability of blood oxygen level- dependent (BOLD) MRI to depict clinically significant prostate tumor hypoxia. Methods and Materials: Thirty-three patients with prostate carcinoma undergoing radical prostatectomy were studied preoperatively, using gradient echo sequences without and with contrast medium enhancement, to map relative tissue oxygenation according to relaxivity rates and relative blood volume (rBV). Pimonidazole was administered preoperatively, and whole-mount sections of selected tumor-bearing slices were stained for pimonidazole fixation and tumor and nontumor localization. Histologic and imaging parameters were independently mapped onto patient prostate outlines. Using 5-mm grids, 861 nontumor grid locations were compared with 237 tumor grids (with >50% tumor per location) using contingency table analysis with respect to the ability of imaging to predict pimonidazole staining. Results: Twenty patients completed the imaging and histologic protocols. Pimonidazole staining was found in 33% of nontumor and in 70% of tumor grids. The sensitivity of the MR relaxivity parameter R-2* in depicting tumor hypoxia was high (88%), improving with the addition of low rBV information (95%) without changing specificity (36% and 29%, respectively). High R-2* increased the positive predictive value for hypoxia by 6% (70% to 76%); conversely, low R-2* decreased the likelihood of hypoxia being present by 26% (70% to 44%) and by 41% (71% to 30%) when combined with rBV information. Conclusion: R-2* maps from BOLD-MRI have high sensitivity but low specificity for defining intraprostatic tumor hypoxia. This together with the negative predictive value of 70% when combined with blood volume information make

Hypoxia in prostate cancer: Correlation of bold-MRI with pimonidazole immunohistochemistry - Initial observations

Purpose: To investigate the ability of blood oxygen level- dependent (BOLD) MRI to depict clinically significant prostate tumor hypoxia. Methods and Materials: Thirty-three patients with prostate carcinoma undergoing radical prostatectomy were studied preoperatively, using gradient echo sequences without and with contrast medium enhancement, to map relative tissue oxygenation according to relaxivity rates and relative blood volume (rBV). Pimonidazole was administered preoperatively, and whole-mount sections of selected tumor-bearing slices were stained for pimonidazole fixation and tumor and nontumor localization. Histologic and imaging parameters were independently mapped onto patient prostate outlines. Using 5-mm grids, 861 nontumor grid locations were compared with 237 tumor grids (with >50% tumor per location) using contingency table analysis with respect to the ability of imaging to predict pimonidazole staining. Results: Twenty patients completed the imaging and histologic protocols. Pimonidazole staining was found in 33% of nontumor and in 70% of tumor grids. The sensitivity of the MR relaxivity parameter R-2* in depicting tumor hypoxia was high (88%), improving with the addition of low rBV information (95%) without changing specificity (36% and 29%, respectively). High R-2* increased the positive predictive value for hypoxia by 6% (70% to 76%); conversely, low R-2* decreased the likelihood of hypoxia being present by 26% (70% to 44%) and by 41% (71% to 30%) when combined with rBV information. Conclusion: R-2* maps from BOLD-MRI have high sensitivity but low specificity for defining intraprostatic tumor hypoxia. This together with the negative predictive value of 70% when combined with blood volume information make

Origin of regional climate differences: role of boundary conditions and model formulation in two GCMs

Model differences in projections of extratropical regional climate change due to increasing greenhouse gases are investigated using two atmospheric general circulation models (AGCMs): ECHAM4 (Max Planck Institute, version 4) and CCM3 (National Center for Atmospheric Research Community Climate Model version 3). Sea-surface temperature (SST) fields calculated from observations and coupled versions of the two models are used to force each AGCM in experiments based on time-slice methodology. Results from the forced AGCMs are then compared to coupled model results from the Coupled Model Intercomparison Project 2 (CMIP2) database. The time-slice methodology is verified by showing that the response of each model to doubled CO2 and SST forcing from the CMIP2 experiments is consistent with the results of the coupled GCMs. The differences in the responses of the models are attributed to (1) the different tropical SST warmings in the coupled simulations and (2) the different atmospheric model responses to the same tropical SST warmings. Both are found to have important contributions to differences in implied Northern Hemisphere (NH) winter extratropical regional 500 mb height and tropical precipitation climate changes. Forced teleconnection patterns from tropical SST differences are primarily responsible for sensitivity differences in the extratropical North Pacific, but have relatively little impact on the North Atlantic. There are also significant differences in the extratropical response of the models to the same tropical SST anomalies due to differences in numerical and physical parameterizations. Differences due to parameterizations dominate in the North Atlantic. Differences in the control climates of the two coupled models from the current climate, in particular for the coupled model containing CCM3, are also demonstrated to be important in leading to differences in extratropical regional sensitivity