A Time Series Model for Assessing the Trend and Forecasting the Road Traffic Accident Mortality

Background: Road traffic accident (RTA) is one of the main causes of trauma and known as a growing public health concern worldwide, especially in developing countries. Assessing the trend of fatalities in the past years and forecasting it enables us to make the appropriate planning for prevention and control. Objectives: This study aimed to assess the trend of RTAs and forecast it in the next years by using time series modeling. Materials and Methods: In this historical analytical study, the RTA mortalities in Zanjan Province, Iran, were evaluated during 2007 - 2013. The time series analyses including Box-Jenkins models were used to assess the trend of accident fatalities in previous years and forecast it for the next 4 years. Results: The mean age of the victims was 37.22 years (SD = 20.01). From a total of 2571 deaths, 77.5% (n = 1992) were males and 22.5% (n = 579) were females. The study models showed a descending trend of fatalities in the study years. The SARIMA (1, 1, 3) (0, 1, 0) 12 model was recognized as a best fit model in forecasting the trend of fatalities. Forecasting model also showed a descending trend of traffic accident mortalities in the next 4 years. Conclusions: There was a decreasing trend in the study and the future years. It seems that implementation of some interventions in the recent decade has had a positive effect on the decline of RTA fatalities. Nevertheless, there is still a need to pay more attention in order to prevent the occurrence and the mortalities related to traffic accidents

The interactive effect of water-borne cadmium and environmental hypoxia on common carp (Cyprinus carpio) metabolism

Regarding to the tight association between aquatic hypoxia and heavy metal contaminations in one hand and the role of both parameters on fish respiration, metabolism of carp could be assessed under single and mutual exposures to hypoxia and cadmium. Following measuring LC50-96h of cadmium (43.679 mg/l) for this species, 80 common carp were exposed to 10 different treatments, including control, acute (43.68 mg/l), sub-lethal (21.84 mg/l) and chronic (4.37 mg/l) cadmium as well as hypoxia for immediately (20% of saturation), 24h (40%) and 7 days (60%), and joint exposure of each similar treatment. By using of respirometer technique, we measured oxygen consumption rate in different time spans to calculate each individual standard metabolic rate (SMR), maximum metabolic rate (MMR), aerobic scope (AS), factorial aerobic scope (FAS) and critical oxygen tension (PCrit). Obtained data show that acute and sub-lethal cadmium treatments led to significant (P<0.05) increases in all metabolic indices in comparison with control group whilst the MMR and AS have been reduced (P<0.05) following hypoxia treatments. Combined treatments of hypoxia and cadmium led to reduce SMR and PCrit in all treatments and MMR, AS and FAS only in acute and sub-lethal treatments. In overall, hypoxia can act as a limiting stressor in carp while cadmium can account as a loading stressor