Effects of nandrolone decanoate on the neuromuscular junction of rats submitted to swimming

This study addressed the effects of nandrolone decanoate (ND) on contractile properties and muscle fiber characteristics of rats submitted to swimming. Male Wistar rats were grouped in sedentary (S), swimming (Sw), sedentary+ND (SND), and swimming+ND (SwND), six animals per group. ND (3 mg/kg) was injected (subcutaneously) 5 days/week, for 4 weeks. Swimming consisted of 60-min sessions (load 2%), 5 days/week, for 4 weeks. After this period, the sciatic nerve extensor digitorum longus (EDL) muscle was isolated for myographic recordings. Fatigue resistance was assessed by the percent (%) decline of 180 direct tetanic contractions (30 Hz). Safety margin of synaptic transmission was determined from the resistance to the blockade of indirectly evoked twitches (0.5 Hz) induced by pancuronium (5 to 9 x 10(-7) M). EDL muscles were also submitted to histological and histochemical analysis (haematoxylin-eosin (HE); nicotinamide adenine dinucleotide-tetrazolium reductase (NADH-TR)). Significant differences were detected by two-way ANOVA (p<0.05). ND did not change body mass, fatigue resistance or kinetic properties of indirect twitches in either sedentary or swimming rats. In contrast, ND reduced the safety margin of synaptic transmission in sedentary animals (SND=53.3+/-4.7% vs. S=75.7+/-2.0%), but did not affect the safety margin in the swimming rats (SwND=75.81+/-3.1% vs. Sw=71.0+/-4.0%). No significant difference in fiber type proportions or diameters was observed in EDL muscle of any experimental group. These results indicate that ND does not act as an ergogenic reinforcement in rats submitted to 4 weeks of swimming. on the other hand, this study revealed an important toxic effect of ND, that it reduces the safety margin of synaptic transmission in sedentary animals. Such an effect is masked when associated with physical exercise. (C) 2004 Elsevier B.V. All rights reserved.

Swimming between the flags: A preliminary exploration of the influences on Australians’ intentions to swim between the flags at patrolled beaches

Swimming at patrolled beaches reduces the likelihood of drownings and near-drownings. The present study tested the theory of planned behaviour (TPB), with the addition of risk perceptions, in predicting people’s intentions to swim between the flags at patrolled beaches. We examined also the predictors of people’s willingness to swim [1] up to 10 metres and [2] more than 10 metres outside of the patrol flags. Participants (N = 526) completed measures of attitudes, subjective norm, perceived behavioural control (PBC), intentions/willingness, and both objective and subjective risk perceptions. Two weeks later, a sub-sample of participants reported on their beach swimming behaviour for the previous fortnight. Attitude and subjective norm predicted intentions to swim between and willingness to swim outside of the flags. Age and PBC influenced willingness to swim beyond the flags. Objective risk predicted willingness to swim beyond the flags (both distances) while subjective risk predicted willingness to swim up to 10 metres outside the flags. People’s intentions to swim between the flags were correlated with their behaviour at follow-up. This study provides a preliminary investigation into an important safety behaviour and identifies factors to target when promoting safe swimming behaviours to prevent drowning deaths on Australian beaches.

Keeping international visitors safe on Australian beaches : informing the content of surf safety messages

In Australia, international tourists/visitors are one of the highest risk groups for drowning at beaches. Swimming in patrolled areas, between the flags, reduces the risk of drowning with most drownings occuring outside these areas. There is a need to understand beliefs which influence the extent to which international tourists/visitors intend to swim between the flags. The theory of planned behaviour (TPB) and, in particular, the indirect beliefs which underpin constructs in the model, represent a means of determining what factors influence this intention. The current study compared international visitors/tourists as having either low or high intentions to swim between the flags on a range of behavioural, normative, and control beliefs. A series of MANOVAs revealed significant differences between the groups in all three of the beliefs. The findings provide insight into potential foci for message content for use in educational campaigns aimed at keeping international visitors safe on Australian beaches.

Effects of prenatal exposure to deltamethrin on forced swimming behavior, motor activity, and striatal dopamine levels in male and female rats

The effects of prenatal exposure of rat pups to 0.08 mg/kg deltamethrin (DTM) on physical, reflex and behavioral developmental parameters, on forced swimming and open-field behaviors, and on striatal monoamine levels at 60 days of age were observed. Maternal and offspring body weight, physical and reflex development were unaffected by the exposure to the pesticide. At 21 days of age, open-field locomotion frequency and immobility duration of male and female offspring were not different between control and exposed animals. However, male rearing frequency was increased in experimental animals. A decreased immobility latency to float and in general activity after the swimming test in male offspring was observed at adult age; no interference was detected in the float duration during the swimming test. In addition, these animals presented higher striatal 3,4-dihydroxyphenylacetic acid (DOPAC) levels without modification in dopamine (DA) levels and an increased DOPAC/DA ratio. These data indicate a higher activity of the dopaminergic system in these animals. Noradrenaline (NA) levels were increased, while MHPG levels were not detectable in the system studied. Serotonin (5-HT) and 5-hydroxyindolacetic acid (5-HIAA) levels, as well as the homovanillic acid (HVA)/DA ratio, were not modified by the exposure to the pesticide. No changes were observed in swimming and open-field behaviors nor were there any changes in striatal monoamines or their metabolites in the female experimental group. In relation to the pesticide formula, the present data showing that prenatal exposure to DTM alters latency to float and the activity of striatal dopaminergic system might reflect a persistent effect of the pesticide on animal motor activity, mainly in males. on the other hand, the decrease in general activity observed in experimental male rats suggests higher levels of emotionality induced by previous exposure to the swimming behavior test in relation to control animals. Data gathered in the present study may be important for the assessment of the safety of pyrethroid insecticides. (C) 2001 Elsevier B.V. All rights reserved.

Food safety and zoonotic enteric pathogens: sources, risk factors and transmission routes of human salmonellosis and campylobacteriosis

Salmonella and Campylobacter are common causes of human gastroenteritis. Their epidemiology is complex and a multi-tiered approach to control is needed, taking into account the different reservoirs, pathways and risk factors. In this thesis, trends in human gastroenteritis and food-borne outbreak notifications in Italy were explored. Moreover, the improved sensitivity of two recently-implemented regional surveillance systems in Lombardy and Piedmont was evidenced, providing a basis for improving notification at the national level. Trends in human Salmonella serovars were explored: serovars Enteritidis and Infantis decreased, Typhimurium remained stable and 4,[5],12:i:-, Derby and Napoli increased, suggesting that sources of infection have changed over time. Attribution analysis identified pigs as the main source of human salmonellosis in Italy, accounting for 43–60% of infections, followed by Gallus gallus (18–34%). Attributions to pigs and Gallus gallus showed increasing and decreasing trends, respectively. Potential bias and sampling issues related to the use of non-local/non-recent multilocus sequence typing (MLST) data in Campylobacter jejuni/coli source attribution using the Asymmetric Island (AI) model were investigated. As MLST data become increasingly dissimilar with increasing geographical/temporal distance, attributions to sources not sampled close to human cases can be underestimated. A combined case-control and source attribution analysis was developed to investigate risk factors for human Campylobacter jejuni/coli infection of chicken, ruminant, environmental, pet and exotic origin in The Netherlands. Most infections (~87%) were attributed to chicken and cattle. Individuals infected from different reservoirs had different associated risk factors: chicken consumption increased the risk for chicken-attributed infections; animal contact, barbecuing, tripe consumption, and never/seldom chicken consumption increased that for ruminant-attributed infections; game consumption and attending swimming pools increased that for environment-attributed infections; and dog ownership increased that for environment- and pet-attributed infections. Person-to-person contacts around holiday periods were risk factors for infections with exotic strains, putatively introduced by returning travellers.

Safety barrier guidelines for home pools.

Shipping list no.: 94-0351-P.

Tourists and beach safety in Queensland, Australia

Surf Life Saving Queensland (SLSQ) is a leading authority on beach safety, providing patrol, education, and rescue services to both tourists and local residents along the coast of Queensland, Australia. SLSQ recognizes that tourists are a target group requiring special attention due to their unfamiliarity with ocean beaches and surfing activities, and in some cases having the additional challenge of poor swimming skills, language barriers, and disorientation in a foreign vacation environment. This article describes SLSQ initiatives to provide beach safety for tourists through a focus on service delivery and partnerships with the tourism industry and relevant government agencies. The positive involvement of SLSQ in tourism is a model for other coastal destinations, given that drowning is the second most frequent cause of injury death among international travelers.

Swimming performance of hatchling green turtles is affected by incubation temperature

In an experiment repeated for two separate years, incubation temperature was found to affect the body size and swimming performance of hatchling green turtles (Chelonia mydas). In the first year, hatchlings from eggs incubated at 26 degrees C were larger in size than hatchlings from 28 and 30 degrees C, whilst in the second year hatchlings from 25.5 degrees C were similar in size to hatchings from 30 degrees C. Clutch of origin influenced the size of hatchlings at all incubation temperatures even when differences in egg size were taken into account. In laboratory measurements of swimming performance, in seawater at 28 degrees C, hatchlings from eggs incubated at 25.5 and 26 degrees C had a lower stroke rate frequency and lower force output than hatchlings from 28 and 30 degrees C. These differences appeared to be caused by the muscles of hatchlings from cooler temperatures fatiguing at a faster rate. Clutch of origin did not influence swimming performance. This finding that hatchling males incubated at lower temperature had reduced swimming ability may affect their survival whilst running the gauntlet of predators in shallow near-shore waters, prior to reaching the relative safety of the open sea.

Swimming against the tide: A study of a youth enrichment program seeking to empower inner-city Black youth

Serious inequities in our K-12 public education system, particularly in regard to the quality of education in predominately Black inner-city schools, are well-documented in the literature (Freeman, 1998; Ross, 1998). Moreover, there is general agreement that the most effective means of ameliorating that situation is through well-thought-out after-school programs and partnership initiatives (Beck, 1993; Gardner et al., 2001). ^ The purpose of this qualitative study was to examine the programmatic interventions of a youth enrichment program for inner-city Black youth currently in place at the Overtown Youth Center (OYC) in Miami, Florida, in order to: (a) discern those factors that support its claim that it is making a difference in students’ lives, (b) explore how any such factors are implemented, and (c) determine whether its interventions have served to equalize the playing field for these youth. ^ Two primary methods of data collection were used for this study. The first was participant observation conducted over the course of two years through a partnership initiative established and led by this author. The second was through in-depth interviews of the Center’s founder, staff, and students. Secondary methods used were the recording of informal conversations and the analysis of written documents. ^ Analysis of the data yielded four features of the Center that are indispensible to the students’ growth. The center provides the youth with (a) physical and psychological safety, (b) supportive relationships, (c) exposure to cultural and educational opportunities, and (d) assistance in building self-esteem. ^ The most significant finding of the study was that OYC has been successful at making a difference in students’ lives and at increasing their aspirations to attend college. By addressing the full spectrum of their needs, the Center has given them many of the necessary tools with which to compete and thereby helped equalize their opportunities to succeed in school and in life. ^ The study also noted a number of challenges for the Center to examine. The main issues that need to be addressed more seriously are staff turnover, staff indifference, nepotism, inconsistent student attendance, and insufficient focus on racial issues and African-American-centered education. Meeting those challenges would engender even greater positive outcomes.^

A Best Practice Process for Fleet Safety Training

This paper outlines a process for fleet safety training based on research and management development programmes undertaken at the University of Huddersfield in the UK (www.hud.ac.uk/sas/trans/transnews.htm) and CARRS-Q in Australia (www.carrsq.qut.edu.au/staff/Murray.jsp) over the past 10 years.