Association of Serum Vitamin D level with Asthenozoospermic Male

Although vitamin D deficiency is one of the most common health problems throughout the world, conflicting information exists on the potential association between serum vitamin D levels and semen quality. Currently available data identifies that vitamin D has a vital role in reproductive process as it affects sperm motility. This study was done with the rationality to evaluate the association between serum vitamin D levels with asthenozoospermic males. This cross-sectional analytic study was conducted on 314 men who attended the Department of Reproductive Endocrinology and Infertility, Bangabandhu Sheikh Mujib Medical University (BSMMU), Bangladesh July 2018 to June 2019. Considering the inclusion and exclusion criteria all participants were categorized into two groups; Group I included 157 asthenozoospermic male and Group II included 157 normozoospermic male according to World Health Organization 'strict' criteria 2010. Participants completed the questionnaires after they had agreed on a informed consent. Blood and semen samples were obtained for assessment and all data were adjusted for age, body mass index (BMI), total motility and progressive motility. Vitamin D levels were classified according to the Endocrine Society guideline. Statistical analyses were carried out by using the Statistical Package for Social Sciences version 22.0 for Windows (SPSS Inc., Chicago, Illinois, USA). The results showed that the mean vitamin D level was 16.63±5.54ng/ml in asthenozoospermic group and 19.83±5.33ng/ml in normozoospermic group. The mean vitamin D level was significantly (p<0.05) lower in asthenozoospermic group. It was noticed that 86.6% patients had vitamin D deficiency (≤20ng/ml) in asthenozoospermic group compared to 56.7% in the normozoospermic group. The study found that low vitamin D was associated with a fivefold increased risk of developing asthenozoospermia at 95% CI (2.74-8.99). Moreover, there was a positive significant correlation (r=0.285; p<0.001) between serum vitamin D level with total motility and progressive motility (r=0.232; p<0.001). Hence, the study suggests a significant association between asthenozoospermia and low vitamin D levels. However, clinical trials are warranted to further reinforce the findings.

Exploring improvisations in road safety in a low-income setting

Road collision types repeat themselves, especially in low- and middle-income countries (LMICs), where countermeasures are often improvised and implemented with little planning. At the Shahbag intersection in Dhaka, Bangladesh, speed bumps were quickly constructed at the exit of the intersection as an improvised road safety measure following the occurrence of a fatal collision, which eventually contributed to another collision between a truck and a car. The events influencing the improvisation decision, and that action's consequences, have been analysed using the Impromap methodology, a variation of the Accimap approach that focusses specifically on improvisation. The applicability of the Impromap as a systems-based approach to the road safety domain is assessed using the predictions described in Rasmussen's risk management framework, and corresponding countermeasures are proposed. The analysis shows that improvisation in the road safety domain is undesirable irrespective of the economic setting as it is likely to eventually contribute to secondary collisions.Practitioner summary: In this paper, the events influencing the improvisation decision following a road crash, and that action's consequences, have been analysed using the Impromap methodology. The applicability of Impromap as a systems-based approach in road safety domain is assessed using the Rasmussen's risk management framework-based predictions, and corresponding countermeasures are proposed.

Taking a mixed-methods approach to collision investigation: AcciMap, STAMP-CAST and PCM

Recently, ergonomics and safety researchers have turned their attention towards applying combinations of sociotechnical methods rather than using single methods in isolation. In the current research, a mixed-method approach combining two systems-based methods, Accimaps and the Systems Theoretic Accident Model and Process - Causal Analysis using Systems Theory (STAMP-CAST), and one cognitive approach, the Perceptual Cycle Model (PCM), were employed in analysing a rail-level crossing incident in Bangladesh. Each method was applied individually to investigate the collision, and interventions were proposed corresponding to incident events at different risk management framework levels. The three methods provided different perspectives of the whole picture, together identifying an array of contributory factors. The complementary nature of these methods aided in proposing a comprehensive set of safety recommendations, thereby demonstrating the benefit of a mixed-method approach for collision investigation in low-income settings.

Overtaking risk modeling in two-lane two-way highway with heterogeneous traffic environment of a low-income country using naturalistic driving dataset

INTRODUCTION

Driver behavior related to overtaking maneuvers, which are considered a major safety risk determinant on two-lane two-way highway in low- and middle-income countries (LMIC), are an important subject of further analysis. This study evaluates safety risk in terms of nature and severity of probable conflicts during overtaking maneuvers on a bi-directional undivided two-lane highway in a heterogeneous traffic environment of a low-income country. Nature and severity of probable conflicts were defined with the application of surrogate safety proximity indicators in real-world naturalistic driving environment.

METHOD

A risk severity model for overtaking maneuver was developed to better understand the significant factors associated with the probability of conflict and its severity during overtaking maneuver using discrete choice modeling approaches. The relevance of three alternate discrete outcome frameworks, namely multinomial logit (ML), ordered probit (OP), and mixed logit (MXL) models are addressed. The best fitted model is identified and estimated. The impact of the significant attributes was also evaluated. The study collected data from a section of two-lane highway in Bangladesh using naturalistic driving from both observational and computer vision techniques. A total of 46 explanatory variables related to overtaking maneuver are assessed.

RESULTS

Speed differential between overtaking and overtaken vehicles have a significant impact on the probability of severe conflicts. Moreover, the presence of a bus as an overtaking vehicle was found to contribute significantly to the severity of conflicts.

CONCLUSIONS

The study makes substantial research contributions related to overtaking behavior and safety risk evaluation during overtaking in mixed traffic environment in low-income countries. The results can be used as a proactive tool for the evaluation of overtaking maneuvers and associated safety risk, and making policy decisions reducing safety risk during overtaking maneuver as well as overall safety, while acknowledging the limited resources and facilities in low-income countries.

Resolving the differences between system development and system operation using STAMP: a road safety case study in a low-income setting

Road safety strategies adopted worldwide have made significant progress in reducing road trauma, but have stagnated more recently. The situation in low- and middle-income countries is even worse with no significant decrease in fatality rates. Safety researchers have argued that adopting sociotechnical systems approach is necessary to make significant advancements and improvements. The aim of this study was to develop a control structure model of the Bangladesh road safety system by identifying the actors and organisations involved across the system. Expert stakeholders were identified and interviewed, and relevant information was gathered in order to generate the Systems Theoretic Accident Model and Process control structure model. Throughout the analysis of this model, differences in the control and feedback mechanisms of the system were identified, and road safety intervention recommendations were made. Future research should also predict potential risks within the system and propose proactive and preventative countermeasures. Practitioner summary: In this article, a Systems Theoretic Accident Model and Process control structure model of the Bangladesh road safety system is developed, and the involved actors are identified. Based on interviews and workshops with expert stakeholders, differences in the controls and feedback mechanisms in the system were identified, and road safety intervention recommendations were made. Abbreviations: BUET: Bangladesh University of Engineering and Technology.

Representing two road traffic collisions in one Accimap: highlighting the importance of emergency response and enforcement in a low-income country

Seemingly erratic pedestrian crossing has become a major source of vehicle-pedestrian collisions on highways in Bangladesh, and across other low- and middle-income countries (LMICs). In this article, we approach the challenge from a sociotechnical systems perspective by using the Accimap method to analyse a pair of time-separated yet interconnected road traffic collisions. The first event involved a truck colliding with a road divider; in the second, fatal incident, a bus hit a university student. The traditional-style investigation conducted immediately after the collision apportioned blame to end users, that is, drivers and pedestrian; however, application of sociotechnical systems thinking revealed the contribution from lack of emergency response and enforcement among many other important factors. Results and recommendations are discussed in terms of reducing the chance and severity of such collisions across LMICs, and in terms of the need to look beyond the end-user, a focus that remains dominant in such settings. Practitioner summary: This paper applies sociotechnical systems thinking to pedestrian safety in Bangladesh by analysing two inter-connected road traffic collisions using a single Accimap. The findings emphasise the importance of implementing road safety interventions that target all system levels, and draw attention to the importance of post-collision response in low-income settings. Abbreviation: BUET: Bangladesh University of Engineering and Technology.

How do fatalistic beliefs affect the attitudes and pedestrian behaviours of road users in different countries? A cross-cultural study

This paper reports on an exploratory investigation of the influence of five different fatalistic belief constructs (divine control, luck, helplessness, internality, and general fatalism) on three classes of self-reported pedestrian behaviours (memory and attention errors, rule violations, and aggressive behaviours) and on respondents' general attitudes to road safety, and how relationships between constructs differ across countries. A survey of over 3400 respondents across Bangladesh, China, Kenya, Thailand, the UK, and Vietnam revealed a similar pattern for most of the relationships assessed, in most countries; those who reported higher fatalistic beliefs or more external attributions of causality also reported performing riskier pedestrian behaviours and holding more dangerous attitudes to road safety. The strengths of relationships between constructs did, however, differ by country, behaviour type, and aspect of fatalism. One particularly notable country difference was that in Bangladesh and, to a lesser extent, in Kenya, a stronger belief in divine influence over one's life was associated with safer attitudes and behaviours, whereas where significant relationships existed in the other countries the opposite was true. In some cases, the effect of fatalistic beliefs on self-reported behaviours was mediated through attitudes, in other cases the effect was direct. Results are discussed in terms of the need to consider the effect of locus of control and attributions of causality on attitudes and behaviours, and the need to understand the differences between countries therein.

Vulnerable road users in low-, middle-, and high-income countries: Validation of a Pedestrian Behaviour Questionnaire

The primary aim of this study was to validate the short version of a Pedestrian Behaviour Questionnaire across six culturally and economically distinct countries; Bangladesh, China, Kenya, Thailand, the UK, and Vietnam. The questionnaire comprised 20 items that asked respondents to rate the extent to which they perform certain types of pedestrian behaviours, with each behaviour belonging to one of five categories identified in previous literature; violations, errors, lapses, aggressive behaviours, and positive behaviours. The sample consisted of 3423 respondents across the six countries. Confirmatory factor analysis was used to assess the fit of the data to the five-factor structure, and a four-factor structure in which violations and errors were combined into one factor (seen elsewhere in the literature). For some items, factor loadings were unacceptably low, internal reliability was low for two of the sub-scales, and model fit indices were generally unacceptable for both models. As such, only the violations, lapses, and aggressions sub-scales were retained (those with acceptable reliability and factor loadings), and the three-factor model tested. Although results suggest that the violations sub-scale may need additional attention, the three-factor solution showed the best fit to the data. The resulting 12-item scale is discussed with regards to country differences, and with respect to its utility as a research tool in cross-cultural studies of road user behaviour.

Micro-level safety risk assessment model for a two-lane heterogeneous traffic environment in a developing country: A comparative crash probability modeling approach

INTRODUCTION

There have been a number of studies that have led to the development of safety risk assessment models to quantify the probability of crash frequencies on roadway facilities (both at micro- and macro-levels), over a specified time period. However, past research has rarely focused on heterogeneous traffic conditions in developing countries.

METHOD

This paper puts forward several models related to the traditional count approach to estimate crash frequency at a micro-level in a non-lane based bi-directional heterogeneous traffic environment. The paper shows the results of dispersion, zero-inflation, and random heterogeneity effects of different exogenous factors by comparing Poisson (P); Negative Binomial (NB); random and fixed parameter Zero-Inflated Poisson (ZIP); and Latent Class Models (LCM). The empirical analysis is based on data from a section of a major national highway in Bangladesh. The performance of the models was validated using different statistical goodness-of-fit measures that compared the estimated and observed average crash frequencies at individual locations. With the identification of the most significant influencing factors, the paper discusses the practical policy implications using partial effects analysis and spatial distribution.

RESULTS

It was found that the Zero-Inflated Random Parameter model gives a slightly better statistical fit when compared to alternative approaches. Practical applications: This micro-level modeling approach would be useful to identify significant crash risk factors; to prioritize road sections according to their safety level; to select site-specific appropriate counter-measures; and devise proactive target oriented safety management strategies. Thus, the results shown here could be a point of reference in the planning, designing, maintaining, and managing two-lane highway sections in developing countries.

Who is responsible for global road safety? A cross-cultural comparison of Actor Maps

The traditional three 'E's approach to road safety (engineering, education, enforcement) has had, and will continue to have, a significant impact on road traffic casualty rates worldwide. Nevertheless, with rising motorisation in many countries, global fatality numbers have changed little over the past decade. Following calls for the application of sociotechnical systems thinking to the problem, we widen the road safety discussion with an additional four 'E's; economics, emergency response, enablement, and, the umbrella term for the approach taken, ergonomics. The research presents an application of Rasmussen's Risk Management Framework to the road safety systems of five distinct nations; Bangladesh, China, Kenya, the UK, and Vietnam. Following site visits, reviews of literature, and interviews with subject matter experts in each of the countries, a series of Actor Map models of the countries' road safety systems were developed. These are compared and discussed in terms of the wide variety of interconnecting organisations involved, their influences on road safety outcomes, the differences between nations, and the need to look beyond road users when designing road safety interventions.

An exercise training combined with dietary program for patients with hypertension

A controlled clinical trial was conducted to determine whether combined exercise training and diet alone reduce blood pressure (BP), body weight and body mass index (BMI) in three weeks. Twenty eight patients with diastolic BP < or = 110 mmHg were assigned to a hypertensive group and another 28 subjects with diastolic BP < or = 90 mmHg were subjected to the same intervention as control group (normotensive group). Exercise training and diet reduced diastolic BP by 24.7 mmHg and systolic BP by 32.8 mmHg in hypertensive group. There was a mean decreased of 5.3 mmHg in the diastolic BP in the normotensive group (P < 0.001). The systolic BP decreased only minimally. The weight loss ranged from 1 kg to 3 kg in hypertensive and 1 kg to 2 kg in the normotensive group. The mean weight loss was 1.6 kg (0.7) in hypertensive and 1.5 kg (0.5) in the normotensive group. In both the groups the weight reduction was highly significant (P < 0.001) and moderately positive correlation was also noted with the fall of BPs. The mean fall of BMI was 0.61 kg/m2 (0.21) and 0.51 (0.2) kg/m2 in the hypertensive and normotensive groups respectively. The findings indicated that a combined exercise training and dietary program could lower BP in patients with mild to moderate hypertension, but its long-term consequences on morbidity and mortality remain to be determined.

Purification, properties and amino acid sequence of a low-Mr abundant seed protein from pea (Pisum sativum L.)

The seeds of pea (Pisum sativum L.) contain several proteins in the albumin solubility fraction that are significant components of total cotyledonary protein (5-10%) and are accumulated in developing seeds concurrently with storage-protein synthesis. One of these proteins, of low Mr and designated 'Psa LA', has been purified, characterized and sequenced. Psa LA has an Mr of 11000 and contains polypeptides of Mr 6000, suggesting that the protein molecules are dimeric. The amino acid sequence contains 54 residues, with a high content (10/54) of asparagine/aspartate. It has no inhibitory action towards trypsin or chymotrypsin, and is distinct from the inhibitors of those enzymes found in pea seeds, nor does it inhibit hog pancreatic alpha-amylase. The protein contains no methionine, but significant amounts of cysteine (four residues per polypeptide), suggesting a possible role as a sulphur storage protein. However, its sequence is not homologous with low-Mr (2S) storage proteins from castor bean (Ricinus communis) or rape (Brassica napus). Psa LA therefore represents a new type of low-Mr seed protein.

The major albumin proteins from pea (Pisum sativum L). Purification and some properties

A scheme is described for the fractionation of pea (Pisum sativum) albumin proteins. By using this scheme, two closely related major albumin proteins have been isolated and purified to homogeneity. The larger protein, designated PMA-L, has Mr approximately 53 000 and consists of two 25 000-Mr subunits, whereas the smaller, PMA-S, has Mr approximately 48 000 and contains two 24 000-Mr subunits. There was no evidence of mixed dimers of the two subunit sizes, despite their close homology as judged by immunological crossreaction, amino acid composition, N-terminal amino acids, tryptic-peptide mapping and CNBr-cleavage products. Both proteins contained significant amounts of sulphur amino acids. The proteins were shown to be located in the soluble cytosol fraction of cotyledon cells and are not significantly degraded on seed germination. Preliminary screening indicates the presence of homologous major albumin proteins in at least three different, though closely related, legume species.