Catastrophe risk models for evaluating disaster risk reduction investments in developing countries.

Major natural disasters in recent years have had high human and economic costs, and triggered record high postdisaster relief from governments and international donors. Given the current economic situation worldwide, selecting the most effective disaster risk reduction (DRR) measures is critical. This is especially the case for low- and middle-income countries, which have suffered disproportionally more economic and human losses from disasters. This article discusses a methodology that makes use of advanced probabilistic catastrophe models to estimate benefits of DRR measures. We apply such newly developed models to generate estimates for hurricane risk on residential structures on the island of St. Lucia, and earthquake risk on residential structures in Istanbul, Turkey, as two illustrative case studies. The costs and economic benefits for selected risk reduction measures are estimated taking account of hazard, exposure, and vulnerability. We conclude by emphasizing the advantages and challenges of catastrophe model-based cost-benefit analyses for DRR in developing countries.

Evaluation of salivary glucose, IgA and flow rate in diabetic patients: a case-control study.

OBJECTIVE: An association between diabetes mellitus and alterations in the oral cavity has been noted. In this study, we evaluated differences between salivary IgA, glucose and flow rate in diabetic patients compared with healthy controls. MATERIALS AND METHODS: Forty patients with type 1 diabetes, 40 patients with type 2 diabetes and 40 healthy controls were selected. Whole unstimulated saliva samples were collected by the standard method and the salivary flow rate was determined. Nephelometric and Pars method were used to measure salivary IgA and salivary glucose concentrations, respectively. Statistical analysis was performed by Chi-square and t test. RESULTS: There were no significant differences in salivary IgA and glucose concentrations between type 1 and type 2 diabetic patients and their matched control subjects (P>0.05). Salivary flow rate was significantly lower in diabetic patients (P<0.05). In addition, DMFT was higher in diabetic patients than the controls. CONCLUSION: Determination of salivary constituents may be useful in the description and management of oral findings in diabetic patients.

Blood Mercury Level and Its Determinants among Dental Practitioners in Hamadan, Iran.

OBJECTIVE: Exposure to mercury can occur in occupational and environmental settings. During clinical work with dental amalgam, the dental personnel are exposed to both metallic mercury and mercury vapor. The aim of the present study was to investigate blood mercury level (BML) and its determinants among dentists practicing in Hamadan city, Iran. MATERIALS AND METHODS: This cross sectional study was done on all dental practitioners of Hamadan (n=43). Dentists were asked to complete a questionnaire, and then 5 ml blood samples were obtained from them. After preparation, mercury concentration of each sample was measured by cold vapor atomic absorption device. Pearson correlation test and regression models served for statistical analysis. RESULTS: The mean blood concentration of mercury was 6.3 µg/l (SD=1.31 range 4.15-8.93). BML was positively associated with age, years in practice, working hours per day, number of amalgam restorations per day, number of amalgam removal per week, sea food consumption, working years in present office, using amalgam powder, using diamond bur for amalgam removal, dry sterilization of amalgam contaminated instruments, and deficient air ventilation. CONCLUSION: BML of dentists in Hamadan was higher than standards. Working hours and number of amalgam restorations per day were significantly correlated with blood mercury.

Evidence for histamine involvement in the effect of histidine loads on food and water intake in rats.

We examined the hypothesis that histidine is a regulator of short-term food and water intake in rats and that this control is through histidine's action as a precursor for histamine. The primary objectives were to measure food and water intake after histidine monohydrochloride monohydrate (His-HCl) given by intragastric (IG) and intraperitoneal (IP) routes of administration and to measure feeding and drinking responses to histidine when given after blockade of the histaminergic pathway by chlorpheniramine (CPA) and alpha-fluoromethylhistidine (FMH). Eight experiments were conducted using a back-to-back design. Rats were given treatment by IP or IG administration, and food and water intake was measured during time periods of 0-1, 1-2, 2-3 and 3-14 h. Histidine consistently reduced food intake with the sensitivity to IP much greater than to the IG route. The effect of histidine given by IP or IG on water intake was similar, generally causing an increase at least in the first hour. Histidine's action was not accounted for by its energy, pH or nitrogen content. Because FMH, which blocks the enzyme converting histidine to histamine, partially reversed the effect of histidine on food and water intake, these results support the hypothesis that histidine regulates food and water intake, at least in part, through its precursor control of histamine.

3-D components of a biological neural network visualized in computer generated imagery. II. Macular neural network organization.

Computer-assisted reconstructions of small parts of the macular neural network show how the nerve terminals and receptive fields are organized in 3-dimensional space. This biological neural network is anatomically organized for parallel distributed processing of information. Processing appears to be more complex than in computer-based neural networks, because spatiotemporal factors figure into synaptic weighting. Serial reconstruction data show anatomical arrangements which suggest that 1) assemblies of cells analyse and distribute information with inbuilt redundancy, to improve reliability; 2) feedforward/feedback loops provide the capacity for presynaptic modulation of output during processing; 3) constrained randomness in connectivities contributes to adaptability; and 4) local variations in network complexity permit differing analyses of incoming signals to take place simultaneously. The last inference suggests that there may be segregation of information flow to central stations subserving particular functions.

3-D components of a biological neural network visualized in computer generated imagery. I. Macular receptive field organization.

Computer-assisted, 3-dimensional reconstructions of macular receptive fields and of their linkages into a neural network have revealed new information about macular functional organization. Both type I and type II hair cells are included in the receptive fields. The fields are rounded, oblong, or elongated, but gradations between categories are common. Cell polarizations are divergent. Morphologically, each calyx of oblong and elongated fields appears to be an information processing site. Intrinsic modulation of information processing is extensive and varies with the kind of field. Each reconstructed field differs in detail from every other, suggesting that an element of randomness is introduced developmentally and contributes to endorgan adaptability.