Transition to farming more likely for small, conservative groups with property rights, but increased productivity is not essential.

Theories for the origins of agriculture are still debated, with a range of different explanations offered. Computational models can be used to test these theories and explore new hypotheses; Bowles and Choi [Bowles S, Choi J-K (2013) Proc Natl Acad Sci USA 110(22):8830-8835] have developed one such model. Their model shows the coevolution of farming and farming-friendly property rights, and by including climate variability, replicates the timings for the emergence of these events seen in the archaeological record. Because the processes modeled occurred a long time ago, it can be difficult to justify exact parameter values; hence, we propose a fitting to idealized outcomes (FIO) method to explore the model's parameter space in more detail. We have replicated the model of Bowles and Choi, and used the FIO method to identify complexities and interactions of the model previously unidentified. Our results indicate that the key parameters for the emergence of farming are group structuring, group size, conservatism, and farming-friendly property rights (lending further support to Bowles and Choi's original proposal). We also find that although advantageous, it is not essential that farming productivity be greater than foraging productivity for farming to emerge. In addition, we highlight how model behaviors can be missed when gauging parameter sensitivity via a fix-all-but-one variation approach.

Mortality of 196,826 Men and Women Working in U.S.-Based Petrochemical and Refinery Operations: Update 1979 to 2010.

OBJECTIVE: To describe mortality trends of men and women working in various petrochemical and refinery operations of a U.S.-based company. METHODS: The cohort consists of full-time employees with at least 1 day of service during 1979 through 2010. Standardized mortality ratios (SMRs) and 95% confidence intervals (CIs) were calculated for 111 possible causes of death studied. RESULTS: SMRs for malignant mesothelioma and asbestosis were highest for the 1940s decade of hire. Increased SMRs were observed for malignant melanoma and motor neuron disease with no obvious work patterns. Decreasing mortality patterns were observed for aplastic anemia and acute nonlymphocytic leukemia. CONCLUSIONS: Mortality surveillance of this large established cohort aids in assessing the chronic health status of the workforce. Identifying methods for incorporating job-exposure matrices and nonoccupational risk factors could further enhance interpretations for some findings such as motor neuron disease.

Systematic Review and Meta-Analysis of Selected Cancers in Petroleum Refinery Workers.

OBJECTIVE: We studied the risk of 11 cancers of a priori interest in petroleum refinery workers. METHODS: Iterative searches identified 36 studies for the 11 cancer sites. Statistical heterogeneity and publication bias were assessed to enhance interpretation of meta-relative risks. RESULTS: Statistical heterogeneity was marked for mesothelioma, but was largely due to study quality. Higher quality studies showed a meta-relative risk (RR) of 3.22, (95% prediction interval 1.45 to 7.23). Melanoma (meta-RR = 1.23) and acute lymphoid leukemia (meta-RR = 1.51), showed results consistent with higher risk, but both were driven by one or two studies. Eight other cancer outcomes showed summary meta-RR's consistent with unity. CONCLUSIONS: Most cancer outcomes are consistent with background risk in refinery workers. This work has clarified an excess mesothelioma risk, conditional on study quality stratification. Continued surveillance is warranted for melanoma and ALL.

Development of an integrated cell culture--real-time RT-PCR assay for detection of reovirus in biosolids.

The current method for viral detection in biosolids is a plaque assay, as specified by the EPA in the 40 CFR Part 503 rule. Development of an integrated cell culture-polymerase chain reaction (ICC-PCR) assay has allowed detection of viruses that are under-detected and undetected by the plaque assay. This study examined the efficiency of the ICC-PCR method to detect mammalian orthoreovirus, a virus typically under-detected in biosolids. Biosolid samples seeded with mammalian orthoreovirus type 1 (Lang) detected to 3 x 10(5) plaque forming units (pfu) with a plaque assay, 10(2)pfu equivalents with real-time RT-PCR and no incubation, and 10(8)pfu equivalents with real-time RT-PCR after 7 days incubation. More infectious virus was detected using ICC-real-time RT-PCR than a plaque assay. Twenty-four environmental samples from three locations around the United States did not plaque with the EPA method; however the ICC-PCR detected infectious reovirus in 13 of the samples. Raw biosolids samples accounted for 12 of the positive samples, and 1 positive was from an aerobically digested sample.