Pesticide Misting System Enhances Residual Pesticide Treatment of HESCO Geotextile.

Residual pesticide treatment of US military materials such as camouflage netting and HESCO blast wall geotextile is an effective way to reduce biting pressure within protected perimeters. However, residual treatments eventually wane and require retreatment in situ, which may not be possible or practical in military scenarios. One solution is to install pesticide misting systems on treated perimeters, which may additively enhance residual treatments, and gradually retreat perimeter material as misted pesticide settles. In this investigation we show that pesticide misting can extend efficacy of residual treatments on HESCO geotextile against mosquitoes and sand flies in a hot-arid desert environment by 1-2 wk.

Transfluthrin Spatial Repellent on US Military Materials Reduces Culex tarsalis Incursion in a Desert Environment.

Standard residual pesticides applied to US military materials such as camouflage netting can reduce mosquito biting pressure in the field but may contribute to the evolution of resistance. However, residual applications of a spatial repellent such as transfluthrin could allow mosquitoes the opportunity to escape, only inducing mortality if insects linger, for example after becoming trapped in a treated tent. In this study we investigated the capability of transfluthrin on 2 types of US military material to reduce natural populations of disease vector mosquitoes in a cool-arid desert field environment in southern California. We found that transfluthrin could reduce Culex tarsalis incursion into protected areas by up to 100% upon initial treatment and up to 45% for at least 16 days posttreatment, showing that this compound could be an effective element in the US Department of Defense integrated vector management system appropriate for further study.

Transfluthrin Spatial Repellent on US Military Camouflage Netting Reduces Tabanids in a Warm-Temperate Environment.

We investigated the capability of transfluthrin on US military camouflage netting to reduce collections of tabanid biting flies in a warm-temperate field environment on the Gulf Coast of Florida. We found that transfluthrin significantly reduced collections of a variety of medically and veterinarily important tabanids inside protected areas by up to 96% upon initial treatment and up to 74% after 20 days posttreatment. These results suggest that transfluthrin could be an effective element in the US Department of Defense integrated pest management system and leveraged in civilian scenarios to protect livestock and humans from potential mechanical transmission of pathogens and disruption of activities caused by painful bites.

Swimming performance in surf: the influence of experience.

This study tested the hypothesis (H1) that surf swimming involves a quantifiable experience component. Sixty-five beach lifeguards with (n = 35) and without surf experience (n = 30) completed: a best effort 200-m swim in a 25-m pool, a calm and a surf sea; an anthropometric survey; maximum effort 30-s swim bench test; 50-m pool swim (25 m underwater). In both groups, time to swim 200 m was slower in calm seas than in the pool and slower in surf than in either calm seas or the pool (p < 0.05). Calm sea swim times of the two groups did not differ significantly, but the no experience group was, on average (Sp-pooled variance), 49 s (62) slower on the 200-m swim in the surf conditions (p < 0.05). A stepwise regression identified surf experience as a predictor of surf swim time (R(2) = 0.32, p < 0.01). It is concluded that there is a significant and quantifiable (18 %) experience factor in surf swimming. This limits the usefulness of pool swim times and other land-based tests as predictors of surf swimming performance. The hypothesis (H1) is accepted.

Basic life support on small boats at sea.

The present study examined the ability of the crew of small fast rescue boats to perform basic life support (BLS) at sea. Tests were undertaken aboard a 67m emergency response and rescue vessel (ERRV), a 9.1m (30ft) and 11.6m (38ft) fast rescue craft ("daughter craft" (DC)). It was hypothesised that the ability to perform BLS on a DC would be significantly impaired when compared with that seen on the ERRV. Nine DC crew volunteered for the study. These tests were undertaken in sea states ranging from 0.5 to 6 (13cm to 4m wave height). Wind speeds ranged between 0 and 35knots. The deterioration observed in the performance of BLS on board the DC compared to that seen on the ERRV was significant (P<0.05) and was due, in part, to a tendency to over-inflate during rescue breathing, and under-compress during BLS when on the DC. Chest compression (CC) was impaired significantly above a sea state 3 (wave height 61-92cm). It is concluded that the performance of BLS on small boats, in particular rescue breathing, is significantly adversely affected by two major factors, motion-induced interruption and early fatigue. As a consequence, the likelihood of conducting fully effective continuous BLS on a small boat in a seaway for any length of time, with a good chance of a successful outcome, is considered to be poor. However, this should not deter rescuers from attempting to make such efforts where practicable.

Thermal status of saturation divers during operational dives in the North Sea.

The principal aim of the present study was to monitor the core temperature (Tc) of a population of saturation divers conducting routine deep dives at different locations in the United Kingdom sector of the North Sea and to assess whether current dive procedures are adequate in preventing deleterious decreases in Tc. A total of 30 divers, with an average (SD) of 19.3 (6.6) yr of experience as saturation divers, participated in the study. The survey included 59 dives conducted at six locations (Scott Field, Norfra Pipeline, Hudson Field, Pierce Field, Forties Field, and Bruce Field) from four Diver Support Vessels (Rockwater 1, Semi 2, Bar Protector, and Discovery). The depth of the dives monitored ranged from 54 to 160 meters of seawater (msw), and the duration of the dives from 31 min to 7 h 30 min. before each dive, divers were requested to ingest a radio pill and strap a data logger to their abdomen. Upon returning to the chamber within the Diver Support Vessel following a dive, they provided subjective ratings of thermal perception (7 point scale) and thermal comfort (4 point scale) for the period just before, during, and immediately after the dive. In 55 dives, Tc of saturation divers working at depths to 160 msw for up to 6 h with water temperatures ranging from 4 degrees to 6 degrees C increased above the pre-dive core temperature of 37.4 degrees (0.620+/-0.6 degrees C). In four dives there was a decrease in Tc: 2 divers had a 0.2 degrees C fall in Tc, and 2 bellmen had a decrease of 0.4 degrees and 1.0 degrees C. The subjective responses of divers indicated that they were thermally neutral (neither warm nor cold) and comfortable before and immediately after the dives. The current practice of providing thermal protection with hot water suits to saturation divers working in the North Sea is adequate for preventing the risk of hypothermia and maintaining thermal comfort.

A century of heroes.

For most of history, humanity just struggled to survive in an unforgiving environment. Only in the past century or so did we start to dominate nature and overrun the planet. Rather than defend outselves against nature, we began to realize, we needed to defend nature against ourselves. Thus was born the environmental movement. These pages recognize men and women who helped give us this awareness--and pointed the way to protecting the only home we have.

Immersion deaths and deterioration in swimming performance in cold water.

BACKGROUND: General hypothermia (deep body temperature <35 degrees C) has been implicated in immersion-related deaths, but many deaths occur too quickly for it to be involved. We investigated changes in swimming capability in cold water to find out whether such changes could lead to swim failure and drowning. METHODS: Ten volunteers undertook three self-paced breaststroke swims in a variable-speed swimming flume, in water at 25 degrees C, 18 degrees C, and 10 degrees C, for a maximum of 90 min. During each swim, we measured oxygen consumption, rectal temperature, swim speed and angle, and stroke rate and length. Swim failure was defined as being unable to keep feet off the bottom of the flume. FINDINGS: All ten swimmers completed 90 min swims at 25 degrees C, eight completed swims at 18 degrees C, and five at 10 degrees C. In 10 degrees C water, one swimmer reached swim failure after 61 min and four were withdrawn before 90 min with rectal temperatures of 35 degrees C when they were close to swim failure. Swimming efficiency and length of stroke decreased more and rate of stroke and swim angle increased more in 10 degrees C water than in warmer water. These variables seemed to characterise impending swim failure. INTERPRETATION: Impaired performance and initial cardiorespiratory responses to immersion probably represent the major dangers to immersion victims. Consequently, treatment should be aimed at symptoms resulting from near-drowning rather than severe hypothermia.