Laboratory-acquired infections due to a variety of bacteria, viruses, parasites, and fungi have been described over the last century, and laboratory workers are at risk of exposure to these infectious agents. However, reporting laboratory-associated infections has been largely voluntary, and there is no way to determine the real number of people involved or to know the precise risks for workers. In this study, an international survey based on volunteering was conducted in biosafety level 3 and 4 laboratories to determine the number of laboratory-acquired infections and the possible underlying causes of these contaminations. The analysis of the survey reveals that laboratory-acquired infections have been infrequent and even rare in recent years, and human errors represent a very high percentage of the cases. Today, most risks from biological hazards can be reduced through the use of appropriate procedures and techniques, containment devices and facilities, and the training of personnel.

In this paper, we model an extended DC state estimation (SE) in an electric power system as a factor graph (FG) and solve it using belief propagation (BP) algorithm. The DC model comprises bus voltage angles as state variables, while the extended DC model includes bus voltage angles and bus voltage magnitudes as state variables. By applying BP to solve the SE problem in the extended DC model, we obtain a Gaussian BP scenario for which we derive closed-form expressions for BP messages exchanged along the FG. The performance of the BP algorithm is demonstrated for the IEEE 14 bus test case. Finally, the application of BP algorithm on the extended DC scenario provides significant insights into a fundamental structure of BP equations in more complex models such as the AC model - the topic we will investigate in our follow up work. As a side-goal of this paper, we aim at thorough and detailed presentation on applying BP on the SE problem in order to make the powerful BP algorithm more accessible and applicable within the power-engineering community.

In this paper, we propose a solution to an AC state estimation problem in electric power systems using a fully distributed Gauss-Newton method. The proposed method is placed within the context of factor graphs and belief propagation algorithms and closed-form expressions for belief propagation messages exchanged along the factor graph are derived. The obtained algorithm provides the same solution as the conventional weighted least-squares state estimation. Using a simple example, we provide a step-by-step presentation of the proposed algorithm. Finally, we discuss the convergence behaviour using the IEEE 14 bus test case.

The proven safe operation and the high availability of aerial ropeways is mainly thanks to their design. This is based on the manufacturer’s extensive experience as well as the strict application of the relevant rules and norms. In that regard, this paper describes an analysis of the haulage ropes on ropeways in case of accidental loads. In solving this problem, analyzed ropeway system with sufficient accuracy was modeled as a system with three degrees of freedom. For solving differential equations we have used the software “Wolfram Mathematica”. At the end of the paper, we discuss the results of the dynamic forces in the haulage ropes in a certain time interval, and the results of the safety factors which in this case are sufficient to ensure reliable operation of the system.

Marketing of fuel wood is an important source of livelihood for most parts of Nigeria. The study examined the economics of marketing of wood fuel in south western Nigeria with a view to determine the socio-economic characteristics of the marketers, the profitability of marketing wood fuel, the market structure and constraints to profitability. Data for the study were obtained from a total sample of 100 randomly selected wood fuel marketers through interviews schedules and application of structured questionnaires. Descriptive statistics was used to analyze the socio-economic characteristics of the marketers. Cash analysis was used to determine the profitability of the enterprise while Gini-coefficient was used to examine the markets’ concentration. The result showed that majority of the marketers was in their active years as 51% were between 21-40 years of age. 71% were female while 56% of them were married. Most of the marketers (76%) had formal education and were well experienced in the business. Cash analysis revealed that marketing of wood fuel is profitable with an average Gross margin of 21,190.65 naira per month. The marketing efficiency was found to be 128% and the rate of return on investment was 28% which indicates that for every 100 naira investment in the business, the marketers will enjoy a return of 28 naira. The value of Gini-Coefficient (0.393) indicates high level of market concentration and inefficiency in the market structure. Transportation was the greatest constraint to the business profitability followed by season of the year and government policy.

Intelligent Transportation Systems rely on understanding, predicting and affecting the interactions between vehicles. The goal of this paper is to choose a small subset from the larger set so that the resulting regression model is simple, yet have good predictive ability for Vehicle agent speed relative to Vehicle intruder. The method of ANFIS (adaptive neuro fuzzy inference system) was applied to the data resulting from these measurements. The ANFIS process for variable selection was implemented in order to detect the predominant variables affecting the prediction of agent speed relative to intruder. This process includes several ways to discover a subset of the total set of recorded parameters, showing good predictive capability. The ANFIS network was used to perform a variable search. Then, it was used to determine how 9 parameters (Intruder Front sensors active (boolean), Intruder Rear sensors active (boolean), Agent Front sensors active (boolean), Agent Rear sensors active (boolean), RSSI signal intensity/strength (integer), Elapsed time (in seconds), Distance between Agent and Intruder (m), Angle of Agent relative to Intruder (angle between vehicles °), Altitude difference between Agent and Intruder (m)) influence prediction of agent speed relative to intruder. The results indicated that distance between Vehicle agent and Vehicle intruder (m) and angle of Vehicle agent relative to Vehicle Intruder (angle between vehicles °) is the most influential parameters to Vehicle agent speed relative to Vehicle intruder.

OBJECTIVE The aim of this study was to determine the prevalence of symmetry, asymmetry and hypoplasia of the intracranial internal carotid artery (ICA), and the possible presence of other variants of the ICA by magnetic resonance angiography (MRA). SUBJECTS AND METHODS This prospective-retrospective study included 1000 subjects who underwent consecutively MRA of the cerebral arteries. 3D-time of flight angiograms were performed according to the standard protocol. We measured the diameter of the ICA and the diameter of the A1 segment of the anterior cerebral artery (ACA). The symmetry, asymmetry and hypoplasia of the ICA, as well hypoplasia of the A1 segment of the ACA were analysed using the vascular asymmetry coefficient. RESULTS The right and left ICA were symmetrical in 93.9% examinees, and asymmetrical in 6%, while ICA hypoplasia was found in only one patient (0.1%). Other variants of the ICA were not found. There was no significant difference in the prevalence of individual variations between male and female patients, and no significant frequency difference was found between anatomical variations in terms of the right and left ICA. In 38.3% patients with asymmetrical ICAs, aplasia or hypoplasia of the A1 segment of the ACA was found on the side of the ICA with a reduced diameter. CONCLUSION Congenital hypoplasia of ICAs is a very rare abnormality, while asymmetry of ICAs is more common. After evaluating severe asymmetry of intracranial ICAs by MRA, MRA of the neck is recommended, especially in patients with a complete anterior part of the circle of Willis.

OBJECTIVE The aim of this study was to investigate the differences in pre-hospital care of patients with acute myocardial infarction between emergency medical services and family medicine. PATIENTS AND METHODS This retrospective descriptive study included patients treated for acute myocardial infarction at the University Clinical Centre of Banja Luka, in the period from 1st January to 31st December 2011. The patients were divided into two groups: patients who received a hospital referral from the family medicine service and those who received one from the emergency medical service. RESULTS The majority of patients (54.8%) received pre-hospital care from emergency medical services, while in 24.8% of cases the care was provided by family medicine physicians. The analysis showed that the time that passed from the onset of symptoms to the visit to the health institution of first medical contact was shorter in the emergency medical service (p<0.001). The average time from the onset of symptoms to arrival at the family practice was 24 hours, and to the emergency service 2 hours. The patients who established their first medical contact with the emergency service reported more severe symptoms than the ones who visited a family practice over the same period of time. CONCLUSION The severity of symptoms affected the patients' decisions to seek help in a timely manner and to choose the facility of first medical contact. Interventions to decrease delay must focus on improving public awareness of acute myocardial infarction symptoms and increasing their knowledge of the benefits of early medical contact and treatment. Continuing education of family practitioners in this field is required.