Perception of residential crowding,classroom experiences,and student health

The present research is based on a typology of crowding experiences incorporating two main dimensions: neutral-personal thwartings and primary-secondary environments. The thwarting dimension concerns the degree to which crowding experiences are associated with spatial inconveniences, alone, or with spatial as well as social constraints. The environmental dimension relates to the type of setting in which crowding experiences occur. A major assumption of this typology is that crowding experiences involving social conflict will be more intense and disruptive to the individual than those in which interpersonal conflict is minimal. The reported study examined the relationship between college students' evaluations of the physical amenity, social climate, and crowdedness of their residential environments, on the one hand, and their sensitivity to crowding in a classroom situation, their academic performance, and the frequency of their visits to the campus health center, on the other. Results indicated that perceived residential crowding and negative perceptions of residential social climate were strongly associated with increased sensitivity to crowding in a classroom situation, impaired course performance, and visits to the student health center. The implications of these correlational findings for future field-experimental research are discussed.     

Toxicological evaluation of methyl tertiary butyl ether (MTBE): Testing performed under TSCA consent agreement

MTBE is a colorless, relatively volatile liquid that has found widespread use as an octane‐enhancing gasoline additive. In 1987, the Environmental Protection Agency's (EPA) Interagency Testing Committee identified MTBE for priority testing consideration based on large production volume, potential widespread exposure, and limited data on chronic health effects. In response, the industry formed the MTBE Health Effects Testing Task Force, which in 1988 signed a Consent Agreement with the EPA requiring the task force member companies to perform toxicological testing on MTBE.

The testing program, which began in the second quarter of 1988, consists of a full complement of short‐ and long‐term tests. The testing completed to date includes genotoxicity (in vivo bone marrow cytogenetics and Drosophila sex‐linked recessive lethal assays), developmental toxicity, acute and subchronic neurotoxicity (motor activity, functional observation battery, and neuropathology), subchronic toxicity, reproductive/fertility effects, and pharmacokinetic studies. There is also an ongoing oncogenicity study in rats and mice. The final report for this chronic study is expected at the end of 1992. The total cost for the program is approximately $3.75 million, which is funded by the 11 Task Force member companies based on market share.

These studies were sponsored by the MTBE Health Effects Testing Task Force, Oxygenated Fuels Association, Washington, D.C.     

The structural simplification of an epidemiological compartment model

It is shown how a multicompartmental infectious disease model can be systematically examined for reduction of structural complexity. For steadystate situations, four basic rules are proposed for eliminating components of flow-lines, whole flow-lines, and compartments, plus combining compartments. An application to a typhoid fever model allows calculations to be done on a pocket calculator. The approach could be particularly important in developing countries.     

Effects of feeding transgenic corn with mCry1Ac or maroACC gene to laying hens for 12 weeks on growth,egg quality and organ health

The objective of the present study was to investigate the effect of feeding two transgenic corn lines containing the mCry1Ac gene from Bacillus thuringiensis strain (BT-799) and the maroACC gene from Agrobacterium tumefaciens strain (CC-2), respectively, on growth, egg quality and organ health indicators. Expression of the mCry1Ac gene confers resistance to Pyrausta nubilalis and the maroACC gene confers tolerance to herbicides. Healthy hens (n=96 placed in cages; 3 hens/cage) were randomly assigned to one of four corn–soybean meal dietary treatments (8 cages/treatment) formulated with the following corn: non-transgenic near-isoline control corn (control), BT-799 corn, CC-2 corn and commercially available non-transgenic reference corn (reference). The experiment was divided into three 4-week phases (week 1 to 4, week 5 to 8 and week 9 to 12), during which hens were fed mash diets. Performance (BW, feed intake and egg production) and egg quality were determined. Following slaughter at the end of 12 weeks of feeding (n=8/treatment), carcass yield and organ weights (heart, liver, spleen, lung, kidneys, stomach and ovary) were recorded; organs and intestines were sampled for histological analysis. Analysis of serum biochemistry parameters to assess the liver and kidney function were performed. No differences in BW, egg production and production efficiency were observed between hens consuming the control diet and hens consuming the BT-799 or CC-2 diet. Haugh unit measures and egg component weights were similar between the control and test groups. Carcass yield was not affected by the diet treatment. Similar organosomatic indices and serum parameters did not indicate the characteristics of organ dysfunction. All observed values of the BT-799 and CC-2 groups were within the calculated tolerance intervals. This research indicates that the performance, egg quality, organ health and carcass yield of laying hens fed diets containing the BT-799 or CC-2 corn line were similar to that of laying hens fed diets formulated with the non-transgenic near-isoline corn with comparable genetic backgrounds.     

Human Health Risk Assessment of Soils Contaminated with Metal(loid)s by Using DGT Uptake: A Case Study of a Former Korean Metal Refinery Site

The human health risk of soils contaminated with As, Pb, Cu, and Zn was evaluated based on pseudo-total concentrations of metal(loid)s, the physiologically based extraction test (PBET), and diffusive gradients in thin films (DGT). Non-carcinogenic (NCR) and carcinogenic (CR) risks exceeded the U.S. Environmental Protection Agency criteria under both the residential and non-residential scenarios. Human bioavailable concentrations (PBET) were much lower than pseudo-total concentrations. The Hazardous Index of NCR (HI (NCR)) for the PBET in the studied soils was 67% and 94% less than that for pseudo-total concentration, respectively, under the non-residential and residential scenarios. Similarly, CR for the PBET was also 65% and 93% less for the two soils. The concentration of metal(loid)s accumulated in the DGT resin was highly correlated with the PBET-extractable concentration (R² > 0.649). Therefore, for both the CR and HI (NCR), the DGT-calculated risk was linearly related to the PBET-calculated risk for the studied soils under both scenarios. The results suggest that DGT uptake and PBET-extracted concentrations are good surrogates for risk estimation and that both J1 and J2 soils require remediation before their use for residential or non-residential purposes.     

Does austerity really kill?

A growing body of the literature has argued that austerity has been bad for health, though without directly measuring austerity. This paper explicitly distinguishes the association of mortality with macroeconomic fluctuations from that with fiscal policy measures, using data for 28 European Union (EU) countries covering the period 1991–2013. The main results present a nuanced, complex picture about the mortality impact of fiscal policies. We confirm the mortality decreasing (increasing) effect of recessions (booms), with the exception of suicide mortality, which shows the opposite effects. Austerity regimes are associated with an increase in all-cause mortality (0.7%). At the same time, fiscal stimuli tend to significantly increase death rates due to cirrhosis or chronic liver disease (3%) and those due to vehicle accidents (4.3%). Our results are sensitive to the set of countries included: when excluding the Baltics, Romania and Hungary, austerity policies turn out to significantly increase suicide-related mortality (2.8%), while the effect on all-cause mortality remains unaffected (0.7%). Overall, however it appears that the austerity-increasing effects are mostly compensated by the (mostly) mortality-decreasing effects of recessions. A notable exception appears to be suicides, which receive a ‘double-boost’ from both recessions and austerity.     

The Nuffield Council’s green light for genome editing human embryos defies fundamental human rights law

In July 2018, the Nuffield Council on Bioethics released the report Genome editing and human reproduction: Social and ethical issues, concluding that human germline modification of human embryos for implantation is not ‘morally unacceptable in itself’ and could be ethically permissible in certain circumstances once the risks of adverse outcomes have been assessed and the procedure appears ‘reasonably safe’. The Nuffield Council set forth two main principles governing anticipated uses and envisions applications that may include health enhancements as a public health measure. This essay provides a critique of three aspects in the Nuffield Council’s Report: its presumption of therapeutic efficacy, its inflation of parental rights to create a certain type of child, and its reliance on a specially commissioned report that appears to distort key definitions in international law.     

Dietary Mannan-oligosaccharides potentiate the beneficial effects of Bifidobacterium bifidum in broiler chicken

This study investigated the effects of dietary Bifidobacterium bifidum (BFD) and mannan-oligosaccharide (MOS), as a synbiotic, on the production performance, gut microbiology, serum biochemistry, antioxidant profile and health indices of broiler chicken. Six dietary treatments were T1 (negative control), T2 (positive control-20 mg antibiotic BMD kg⁻¹ diet; BMD: bacitracin methylene disalicylate), T3 (0·1% MOS + 10⁶ CFU BFD per g feed), T4 (0·1% MOS + 10⁷ CFU BFD per g feed), T5 (0·2% MOS + 10⁶ CFU BFD per g feed) and T6 (0·2% MOS + 10⁷ CFU BFD per g feed). Significantly (P < 0·01) better growth performance and efficiency was observed in birds supplemented with 0·2% MOS along with 10⁶ CFU BFD per g of feed compared to BMD and control birds. Supplementation with 0·2% MOS along with either 10⁶ or 10⁷ CFU BFD per g feed reduced (P < 0·01) the gut coliform, Escherichia coli, total plate count, and Clostridium perfringens count and increased the Lactobacillus and Bifidobacterium count. Significantly (P < 0·01) higher serum and liver antioxidant enzyme pool, serum HDL cholesterol and lower serum glucose, triglyceride, total cholesterol, cardiac risk ratio, atherogenic coefficient and atherogenic index of plasma were observed in birds supplemented with 0·2% MOS along with 10⁶ CFU BFD per g of feed compared to control or BMD supplemented birds. Better production performance, gut microbial composition, serum biochemistry, antioxidant profile and health indices were depicted by broiler chicken supplemented with 0·2% MOS and 10⁶ CFU BFD per g of feed.