Evaluation of the Efficiency of Active and Passive Surveillance in the Detection of African Swine Fever in Wild Boar

African swine fever (ASF) is one of the most severe diseases of pigs and has a drastic impact on pig industry. Wild boar populations play the role of ASF genotype II virus epidemiological reservoir. Disease surveillance in wild boar is carried out either by testing all the wild boar found sick or dead for virus detection (passive surveillance) or by testing for virus (and antibodies) all hunted wild boar (active surveillance). When virus prevalence and wild boar density are low as it happens close to eradication, the question on which kind of surveillance is more efficient in detecting the virus is still open. We built a simulation model to mimic the evolution of the host-parasite interaction in the European wild boar and to assess the efficiency of different surveillance strategies. We constructed a deterministic SIR model, which estimated the probability to detect the virus during the 8 years following its introduction, using both passive and active surveillance. Overall, passive surveillance provided a much larger number of ASF detections than active surveillance during the first year. During subsequent years, both active and passive surveillance exhibited a decrease in their probability to detect ASF. Such decrease, though, was more pronounced for passive surveillance. Under the assumption of 50% of carcasses detection, active surveillance became the best detection method when the endemic disease prevalence was lower than 1.5%, when hunting rate was >60% and when population density was lower than 0.1 individuals/km2. In such a situation, though, the absolute probability to detect the disease was very low with both methods, and finding almost every carcass is the only way to ensure virus detection. The sensitivity analysis shows that carcass search effort is the sole parameter that increases proportionally the chance of ASF virus detection. Therefore, an effort should be made to promote active search of dead wild boar also in endemic areas, since reporting wild boar carcasses is crucial to understand the epidemiological situation in any of the different phases of ASF infection at any wild boar density.

USING ABSOLUTE PROBABILITY JUDGEMENT METHOD FOR HUMAN RELIABILITY ASSESSMENT - A CASE STUDY

Human reliability assessment is becoming increasingly important in risk assessment in all industrial systems. All methods for human reliability assessment are used to estimate human error probabilities, which is a measure of human reliability. Human error assessment is certainly a challenge fo r all the experts involved in risk assessment today. In Serbia, this issue has not received proper attention yet. Therefore, this paper presents the case study which confirmed that the usage of Absolute Probability Judgement for proper human reliability assessment. This approach was used in a case study of the Electric Power Company in Serbia (hereinafter EPCS) for the purpose of the analysis accident of a repair intervention on a 10/0.4 kV steel lattice tower “Nova Kolonija” (jurisdiction of EPCS, Veliki Trnovac, ED “Jugoistok”, Nis, Serbia). The case study performed at the EPCS has confirmed that the conventional APJ approach is not only highly applicable for quantification of human errors, but also comprehensive and simple to use in risk assessment of complex systems. Key words: Absolute Probability Judgement, Human Reliability Assessment, Accident, Case Study

Calculation of Misjudgment Probability for Product Inspection Based on Measurement Uncertainty

It is important to research into the misjudgment probability of product inspection based on measurement uncertainty, which is of great significance to improve the reliability of inspection results. This paper mainly focused on total inspection and sampling inspection methods and regarded the misjudgment probability as the index to provide quantitative misjudgment risk results for both producer and consumer sides. Through the absolute probability and the conditional probability model, the estimation formula of the total inspection misjudgment rate is deduced, respectively, and the calculation methods of qualification determination and misjudgment rate of the full inspection results are studied. According to the total inspection misjudgment rate, the methods of misjudgment rate of sampling inspection and qualification determination of measurement results are researched. The misjudgment rate of measurement results is calculated based on the exhaustive method and the Monte-Carlo simulation. The estimation results show that the misjudgment probabilities calculated by absolute probability models can be used as the basis for the selection of the measurement plan for product inspection. The misjudgment probability calculated by conditional probability models is more directly to reflect the risks for both producer and consumer sides, and it prompts inspectors to make decisions more carefully.

A new index for assessing the value of importance of species - VIS

ABSTRACT Phytosociological analysis in native forests is performed considering the horizontal and vertical structure of the studied population, whose most expressive parameters are the density, dominance, frequency, value of coverage and value of importance of species. Many phytosociological studies include a value of importance of species calculated by adding density, dominance and frequency, in their relative forms, however, this estimator is a mathematical impropriety because the result is a sum of indexes and does not express the true meaning of species' value. This is because the estimator is still influenced predominantly by the density of occurrence of species and cannot capture the relevant hierarchical participation of emerging species that occur with low density in the biocoenosis. In this work, we propose a new index to characterize the value of importance of species based on the hierarchy and spatial absolute probability of the species in the biocoenosis, illustrated with data from a forest fragment of semideciduous tropical forest located in Cassia, MG, Brazil. The new index appropriately expressed the importance of species in the evaluated fragment.

Social origin and the risks of disadvantage in Denmark and Norway: the early life course of young adults

This study uses comparable Danish and Norwegian administrative registers in the period 1992 to 2003 to examine how social origin affects unemployment risks and social assistance reception over the early life course. Denmark and Norway have traditionally been viewed as similar in political, cultural and social aspects. However, labour market regulation in Denmark is more liberal than in Norway. This study therefore serves as a unique comparison of the impact of social origin under varying conditions of labour market regulation. Although the absolute probability of being disadvantaged decreases as individuals progress in age from 20 to 30 and varies between Denmark and Norway, the relative impact of social background is stable and similar. The results offer little support to theories that put a strong emphasis on inter-generational transmission through educational achievements, but rather point toward the importance of ascriptive resources. Generalised estimating equations are used to assess the repeated outcomes.

Using underwater video to directly estimate gear selectivity: the retention probability for walleye (Sander vitreus) in gill nets

We developed a new approach for directly quantifying selection parameters for fishing gear using a dual underwater video camera apparatus and employed the method to estimate gill net retention probability for walleye (Sander vitreus). The method allows observation of fish behavior around fishing gear and estimation of the absolute probability of fish encountering, contacting, or being retained by the gear. We demonstrated the applicability of this method by quantifying the probability that walleye were retained in multifilament nylon gill nets after contacting the nets. Walleye with total lengths 2.49 times the perimeter of the mesh were most likely to be retained, and retention probability peaked at 0.60 (95% confidence interval 0.41–0.90), meaning 40% of walleye that were the ideal size for a given mesh escaped after contacting the net. Our empirically derived retention curve exhibited a steep ascending limb and strong positive skew because of walleye morphology and the tendency for larger walleye to be captured by tangling. Most walleye that avoided capture did not fully enter the mesh or backed out of the mesh after they became temporarily wedged or tangled.