Relation Between S2 and Later Generation Testcrosses of Two Corn Populations

Determination of the relative combining abilities of corn (Zea mays L.) inbred lines is an important feature of applied corn breeding programs. Combining ability is measured by the relative performance of a line in testcrosses to one or more testers. Inbred lines from BS13(S2)Cl and BSCB1(R)C7 corn populations were evaluated at the S2 and later generations of inbreeding. Intense selection was practiced among and within lines during inbreeding to develop the S5-equivalent and S8 generation lines. The objective of this study was to determine if the combining ability of lines in early generations (S2) of inbreeding was similar to the combining ability of lines at later generations of inbreeding. Testcross trials were conducted at four Iowa locations. Genetic correlations between the S2 and later generation testcrosses for gram yield were 0.9.7 for BS13(S)Cl and 0.86 for BSCB1(R)C7. The S2 testcross data were highly predictive of S8 testcross data, suggesting that early testing was effective in discriminating among these lines for relative combining abilities at later generations of inbreeding

Sex Differences in the Subjective Effects of Oral Δ\u3csup\u3e9\u3c/sup\u3e-THC in Cannabis Users

Previous studies suggest that there are sex differences in endocannabinoid function and the response to exogenous cannabinoids, though data from clinical studies comparing acute cannabinoid effects in men and women under controlled laboratory conditions are limited. To further explore these potential differences, data from 30 cannabis users (N=18 M, 12 F) who completed previous Δ9-tetrahydrocannabinol (Δ9-THC) discrimination studies were combined for this retrospective analysis. In each study, subjects learned to discriminate between oral Δ9-THC and placebo and then received a range of Δ9-THC doses (0, 5, 15 and a “high” dose of either 25 or 30 mg). Responses on a drug-discrimination task, subjective effects questionnaire, psychomotor performance tasks, and physiological measures were assessed. Δ9-THC dose-dependently increased drug-appropriate responding, ratings on “positive” visual analog scale (VAS) items (e.g., Good Effects, Like Drug, Take Again), and items related to intoxication (e.g., High, Stoned). Δ9-THC also dose-dependently impaired performance on psychomotor tasks and elevated heart rate. Sex differences on VAS items emerged as a function of dose. Women exhibited significantly greater subjective responses to oral drug administration than men at the 5 mg Δ9-THC dose, whereas men were more sensitive to the subjective effects of the 15 mg dose of Δ9-THC than women. These results demonstrate dose-dependent separation in the subjective response to oral Δ9-THC administration by sex, which might contribute to the differential development of problematic cannabis use

Global monitoring of antimicrobial resistance based on metagenomics analyses of urban sewage

Antimicrobial resistance (AMR) is a serious threat to global public health, but obtaining representative data on AMR for healthy human populations is difficult. Here, we use meta-genomic analysis of untreated sewage to characterize the bacterial resistome from 79 sites in 60 countries. We find systematic differences in abundance and diversity of AMR genes between Europe/North-America/Oceania and Africa/Asia/South-America. Antimicrobial use data and bacterial taxonomy only explains a minor part of the AMR variation that we observe. We find no evidence for cross-selection between antimicrobial classes, or for effect of air travel between sites. However, AMR gene abundance strongly correlates with socio-economic, health and environmental factors, which we use to predict AMR gene abundances in all countries in the world. Our findings suggest that global AMR gene diversity and abundance vary by region, and that improving sanitation and health could potentially limit the global burden of AMR. We propose metagenomic analysis of sewage as an ethically acceptable and economically feasible approach for continuous global surveillance and prediction of AMR.Peer reviewe

A Meaningful U.S. Cap-and-Trade System to Address Climate Change

There is growing impetus for a domestic U.S. climate policy that can provide meaningful reductions in emissions of CO2 and other greenhouse gases. In this article, I propose and analyze a scientifically sound, economically rational, and politically feasible approach for the United States to reduce its contributions to the increase in atmospheric concentrations of greenhouse gases. The proposal features an up-stream, economy-wide CO2 cap-and-trade system which implements a gradual trajectory of emissions reductions over time, and includes mechanisms to reduce cost uncertainty. I compare the proposed system with frequently discussed alternatives. In addition, I describe common objections to a cap-and-trade approach to the problem, and provide responses to these objections

Setting a baseline for global urban virome surveillance in sewage

The rapid development of megacities, and their growing connectedness across the world is becoming a distinct driver for emerging disease outbreaks. Early detection of unusual disease emergence and spread should therefore include such cities as part of risk-based surveillance. A catch-all metagenomic sequencing approach of urban sewage could potentially provide an unbiased insight into the dynamics of viral pathogens circulating in a community irrespective of access to care, a potential which already has been proven for the surveillance of poliovirus. Here, we present a detailed characterization of sewage viromes from a snapshot of 81 high density urban areas across the globe, including in-depth assessment of potential biases, as a proof of concept for catch-all viral pathogen surveillance. We show the ability to detect a wide range of viruses and geographical and seasonal differences for specific viral groups. Our findings offer a cross-sectional baseline for further research in viral surveillance from urban sewage samples and place previous studies in a global perspective

Sex differences in the subjective effects of oral Δ9-THC in cannabis users

Previous studies suggest that there are sex differences in endocannabinoid function and the response to exogenous cannabinoids, though data from clinical studies comparing acute cannabinoid effects in men and women under controlled laboratory conditions are limited. To further explore these potential differences, data from 30 cannabis users (N=18 M, 12 F) who completed previous Δ(9)-tetrahydrocannabinol (Δ(9)-THC) discrimination studies were combined for this retrospective analysis. In each study, subjects learned to discriminate between oral Δ(9)-THC and placebo and then received a range of Δ(9)-THC doses (0, 5, 15 and a “high” dose of either 25 or 30 mg). Responses on a drug-discrimination task, subjective effects questionnaire, psychomotor performance tasks, and physiological measures were assessed. Δ(9)-THC dose-dependently increased drug-appropriate responding, ratings on “positive” visual analog scale (VAS) items (e.g., Good Effects, Like Drug, Take Again), and items related to intoxication (e.g., High, Stoned). Δ(9)-THC also dose-dependently impaired performance on psychomotor tasks and elevated heart rate. Sex differences on VAS items emerged as a function of dose. Women exhibited significantly greater subjective responses to oral drug administration than men at the 5 mg Δ(9)-THC dose, whereas men were more sensitive to the subjective effects of the 15 mg dose of Δ(9)-THC than women. These results demonstrate dose-dependent separation in the subjective response to oral Δ(9)-THC administration by sex, which might contribute to the differential development of problematic cannabis use