Controversy surrounds occupational health and safety regulators, with some observers claiming that workplace regulations damage firms' competitiveness and destroy jobs and others arguing that they make workplaces safer at little cost to employers and employees. We analyzed a natural field experiment to examine how workplace safety inspections affected injury rates and other outcomes. We compared 409 randomly inspected establishments in California with 409 matched-control establishments that were eligible, but not chosen, for inspection. Compared with controls, randomly inspected employers experienced a 9.4% decline in injury rates (95% confidence interval =-0.177 to -0.021) and a 26% reduction in injury cost (95% confidence interval =-0.513 to -0.083). We find no evidence that these improvements came at the expense of employment, sales, credit ratings, or firm survival.

Bradavidin is a homotetrameric biotin-binding protein from Bradyrhizobium japonicum, a nitrogen fixing and root nodule-forming symbiotic bacterium of the soybean. Wild-type (wt) bradavidin has 138 amino acid residues, whereas the C-terminally truncated core-bradavidin has only 118 residues. We have solved the X-ray structure of wt bradavidin and found that the C-terminal amino acids of each subunit were uniquely bound to the biotin-binding pocket of an adjacent subunit. The biotin-binding pocket occupying peptide (SEKLSNTK) was named "Brad-tag" and it serves as an intrinsic stabilizing ligand in wt bradavidin. The binding of Brad-tag to core-bradavidin was analysed by isothermal titration calorimetry and a binding affinity of ∼25 µM was measured. In order to study the potential of Brad-tag, a green fluorescent protein tagged with Brad-tag was prepared and successfully concentrated from a bacterial cell lysate using core-bradavidin-functionalized Sepharose resin.

Multisubunit RNA polymerase (RNAP) is the central information-processing enzyme in all cellular life forms, yet its mechanism of translocation along the DNA molecule remains conjectural. Here, we report direct monitoring of bacterial RNAP translocation following the addition of a single nucleotide. Time-resolved measurements demonstrated that translocation is delayed relative to nucleotide incorporation and occurs shortly after or concurrently with pyrophosphate release. An investigation of translocation equilibrium suggested that the strength of interactions between RNA 3' nucleotide and nucleophilic and substrate sites determines the translocation state of transcription elongation complexes, whereas active site opening and closure modulate the affinity of the substrate site, thereby favoring the post- and pre-translocated states, respectively. The RNAP translocation mechanism is exploited by the antibiotic tagetitoxin, which mimics pyrophosphate and induces backward translocation by closing the active site.

Ethyl propionate is a model for fatty acid ethyl esters used as first generation biodiesel. The atmospheric chemistry of ethyl propionate was investigated at 980 mbar total pressure. Relative rate measurements in 980 mbar N2 at 293 ± 0.5 K were used to determine rate constants of k(C2H5C(O)OC2H5 + Cl)=(3.11 0.29) 10-11 and k(C2H5C(O)OC2H5 + OH)=(7.43 0.78) 10-12 cm3 molecule-1 s-1. At 273-313 K the following Arrhenius expression was determined: k(C2H5C(O)OC2H5 + Cl)=(1.02 0.29) 10-11 cm3 molecule-1 s-1 exp((2.64±0.61)kJ mol-1/(RT)). The chlorine atom initiated oxidation of ethyl propionate in 980 mbar N2 gave the following products (stoichiometric yields): ClCH2CH2C(O)OC2H5 (0.204 ± 0.031), CH3CHClC(O)OC2H5 (0.251 ± 0.040), and C2H5C(O)OCHClCH3 (0.481 ± 0.088). The chlorine atom initiated oxidation of ethyl propionate in 980 mbar of N2/O2 (with and without NOx) gave the following products: ethyl pyruvate (CH3C(O)C(O)OC2H5), propionic acid (C2H5C(O)OH), formaldehyde (HCHO), and, in the presence of NOx, PAN (CH3C(O)OONO2). The lack of acetaldehyde as a product suggests that the CH3CH(O)C(O)OC2H5 radical favours isomerisation over decomposition. From the observed product yields we conclude that H-abstraction by chlorine atoms from ethyl propionate occurs 20.4 ± 3.1%, 25.1 ± 4.0%, and 48.1 ± 8.8% from the CH3-,-CH2-, and -OCH2- group, respectively. The rate constant and branching ratios for the reaction between ethyl propionate and the OH radical were investigated theoretically using quantum mechanical calculations and transition state theory. The stationary points along the reaction path were optimized with CCSD(T)-F12/VDZ-F12//BH&HLYP/aug-cc-pVTZ level of theory, it was estimated that OH radicals abstracts hydrogen atoms primarily from the -OCH2- group (80%).

Objectives. We investigated whether abused and neglected children are at risk for negative physical health outcomes in adulthood. Methods. Using a prospective cohort design, we matched children (aged 0-11 years) with documented cases of physical and sexual abuse and neglect from a US Midwestern county during 1967 through 1971 with nonmaltreated children. Both groups completed a medical status examination (measured health outcomes and blood tests) and interview during 2003 through 2005 (mean age = 41.2 years). Results. After adjusting for age, gender, and race, child maltreatment predicted above normal hemoglobin, lower albumin levels, poor peak airflow, and vision problems in adulthood. Physical abuse predicted malnutrition, albumin, blood urea nitrogen, and hemoglobin A1C. Neglect predicted hemoglobin A1C, albumin, poor peak airflow, and oral health and vision problems, Sexual abuse predicted hepatitis C and oral health problems. Additional controls for childhood socioeconomic status, adult socioeconomic status, unhealthy behaviors, smoking, and mental health problems play varying roles in attenuating or intensifying these relationships. Conclusions. Child abuse and neglect affect long-term health status-increasing risk for diabetes, lung disease, malnutrition, and vision problems-and support the need for early health care prevention.(Am J Public Health. Published online ahead of print April 19, 2012: e1-e10. doi:10.2105/AJPH.2011.300636).

The first absorption band of OCS (carbonyl sulfide) is analyzed using potential energy surfaces and transition dipole moment functions of the lowest four singlet and the lowest four triplet states. Excitation of the 2 (1)A(') state is predominant except at very low photon energies. It is shown that the vibrational structures in the center of the band are due to excitation of the 2 (3)A(')(') triplet state, whereas the structures at very low energies are caused by bending excitation in the potential wells of states 2 (1)A(') and 1 (1)A(')(').

Purpose A case of methotrexate toxicity from intralesional treatment of squamous cell carcinoma of the hands in a peritoneal dialysis patient is reported. Summary A 68-year-old Caucasian man receiving peritoneal dialysis for end-stage renal disease complained to his primary care physician of shortness of breath, mouth and hand sores, nausea, and general malaise. Four days before his office visit, the patient received 25 mg of methotrexate intralesionally for refractory squamous cell carcinoma of his hands. The patient had several pustular lesions on both hands. On admission, the patient had a normal complete blood cell count and elevated liver enzyme levels. On hospital day 3, the patient's white blood cell count was 1,300 cells/μL, platelet count was 134,000 platelets/μL, hemoglobin value was 12.4 g/dL, and hematocrit was 37%. Folic acid 1 mg i.v. every six hours and leucovorin 10 mg/m(2)(20 mg) i.v. every six hours was initiated. His serum methotrexate concentration was 0.03 μmol/L on hospital day 6. The leucovorin dosage was increased to 200 mg i.v. every six hours. Platelets were administered, and the patient was switched to four-hour treatments of high-flux membrane hemodialysis for two consecutive days. The patient was discharged on hospital day 14. Mild mucositis was still present, but the patient had improved substantially and was discharged to a rehabilitation facility. Conclusion A 68-year-old peritoneal dialysis patient who was treated with 25 mg of intralesional methotrexate for squamous cell carcinoma of the hands developed pancytopenia, mucositis, and hepatotoxicity as a result of systemic absorption and prolonged elimination.

The sulfur kinetic isotope effect (KIE) in the reaction of carbonyl sulfide (OCS) with O(³<i>P</i>) was studied in relative rate experiments at 298 ± 2 K and 955 ± 10 mbar. The reaction was carried out in a photochemical reactor using long path FTIR detection and data were analyzed using a non-linear least squares spectral fitting procedure with line parameters from the HITRAN database. The ratios of the rate of the reaction of OC³⁴S relative to OC³²S were found to be 0.9783 ± 0.0062 (³⁴<i>ε</i>=(-21.7 ± 6.2)‰). The KIE was also calculated using quantum chemistry and classical transition state theory; at 300 K the isotopic fractionation was found to be ³⁴<i>ε</i>=-14.8‰. The OCS sink reaction with O(³<i>P</i>) cannot explain the large isotopic fractionation in ³⁴S, over +73‰, indicated by remote sensing data. In addition,³⁴<i>ε</i> in OCS photolysis and OH oxidation are not larger than 10‰, indicating that, based on isotopic analysis, OCS is an acceptable source of background stratospheric sulfate aerosol.