ATV rollover, rider response, and determinants of injury: in-depth analysis of video-documented ATV rollover events.

OBJECTIVE: All-terrain vehicle (ATV) rollover events can lead to serious and fatal injuries. Crush protection devices (CPDs) are intended to reduce injury by reducing the frequency of significant contact between an inverted ATV and rider. Currently, field data on real-world ATV rollovers are primarily limited to injury causing events and lack ATV and rider dynamics necessary to evaluate injury mitigation effectiveness and possible unintended consequences of CPDs. Unlike restrained automobile occupants, ATV rider posture and positioning are highly variable and scant data are available to define the dynamically changing rider position in a roll scenario. Additional data on the complex real-world dynamics and interactions of riders and vehicles are needed to further develop and evaluate the effectiveness of rollover injury prevention strategies. METHODS: Using YouTube videos of real-world rollover events, vehicle, environment, and rider factors were categorized with a focus on vehicle dynamics and rider responses, including dismount kinematics. RESULTS: One hundred twenty-nine ATV rollover events were coded, with side rolls representing 47%, rear 44%, and forward rolls 9%. The speed at onset of roll was relatively low, with 86% of the rolls occurring at speeds of 10 mph or less and 53% occurring at less than 3 mph. No injury was identified for 79% of the events; 16% resulted in injury due to ATV contact and 5% resulted in injury unrelated to ATV contact. Active dismount of the ATV was a commonly employed strategy, with 63% of the riders attempting active dismount, resulting in successful separation from the ATV in 72% of the attempts. The overall injury rate for riders attempting active dismount was 15% and the injury rate for riders not attempting active dismount was 32%. This investigation confirmed the importance of active rider movements, including active dismount and subsequent separation in determining the outcome of ATV roll events. CONCLUSIONS: Rider active dynamics need to be considered when introducing new injury prevention strategies that may obstruct, impede, or otherwise contact riders during an attempted separation. To the authors' knowledge, this is the first systematic use of real-world video-documented ATV rollover events to quantify and analyze ATV rollover dynamics and rider responses. These data and techniques can guide effective design and implementation of injury mitigation strategies.

Agricultural pollutant penetration and steady state in thick aquifers.

The leakage of pollutants from agricultural lands to aquifers has increased greatly, driven by increasing fertilizer and pesticide use. Because this increase is recent, ground water pollutant concentrations, loads, and exports may also be increasing as pollutants penetrate more deeply into aquifers. We established in an aquifer profile a ground water recharge and pollutant leakage chronology in an agricultural landscape where 30 m of till blankets a 57-m thick sandstone aquifer. Pollutant concentrations increased from older ground water (1963) at the aquifer base to younger ground water (1985) at its top, a signal of increasing pollutant leakage. Nitrate-N increased from 0.9 to 13.2 mg/L, implying that leakage increased from 1.9 to 16.5 kg/ha/year. Nitrate load and export could increase from 130% to 230% before reaching a steady state in 20 to 40 years. Chloride increases were similar. Pesticide residues alachlor ethane sulfonic acid (ESA), metolachlor ESA, and atrazine residues partially penetrated the aquifer profile. Their concentration-age-date patterns exhibited an initial increase and then a leveling corresponding to the timing of product adoption and leveling of demand. Unlike NO(3), projecting pesticide residue steady states is complicated by the phasing in and out of pesticide products over time; for example, neither alachlor nor atrazine is currently used in the area, and newer products, which have not had time to transit to the aquifer, have been adopted. The circumstances that resulted in the lack of a pollutant steady state are not rare; thus, the lack of steady states in agricultural region aquifers may not be uncommon.

Gender and beliefs about work force discrimination in the United States and Australia.

Beliefs about gender discrimination in the work force were investigated among a sample of American (n = 201) and Australian (n = 177) business students. Significant differences between genders in beliefs about the existence of gender discrimination were indicated, with women being more likely than men to affirm its existence, particularly in the area of salary discrimination. In addition, there were differences between genders and between countries in assessment of the factors that might lead to lower participation of women in management and in the assessment of avenues of advancement for women.

Nonsteroidal anti-inflammatory drugs and necrotising fasciitis. An update.

Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen, naproxen and others are the treatment of choice for mild to moderate pain. Because of the relative safety and efficacy of NSAIDs, many of the agents are now available in the US and in other parts of the world without a physician prescription. While these drugs are relatively well tolerated, adverse effects resulting from their use can occur. One such adverse effect recently linked to NSAID use is necrotising fasciitis. Reports of necrotising fasciitis possibly associated with NSAID use have been published in both the medical and lay literature. Several hypotheses regarding a possible association between NSAIDs and the development of necrotising fasciitis have appeared in the literature. One hypothesis is a simple masking of the signs and symptoms of an existing infection, leading to a delay in diagnosis. Some authors have speculated that in certain skin and soft-tissue infections, particularly those caused by group A beta-haemolytic streptococci, this delay in diagnosis may have allowed a simple infection to progress to necrotising fasciitis. Other postulated mechanisms of NSAID involvement in the development of necrotising fasciitis include an impairment of natural host defense mechanisms. A review of the medical literature for reports of possible NSAID-associated necrotising fasciitis revealed that the events were rare, but clinically significant. From the available evidence, a causal relationship between NSAIDs and necrotising fasciitis cannot be established.

Identifying service quality strengths and weaknesses using SERVQUAL: a study of dental services.

The goal of this study was to examine responses among dental patients to the most recent version of SERVQUAL, and to evaluate that instrument as a tool for measuring satisfaction in a dental practice. Items on the reliability and responsiveness dimensions produced the lowest satisfaction ratings, while improvements in providing services as promised and instilling confidence have the greatest potential for producing higher satisfaction among patients. Finally, using open-ended questions, we identified a number of patient events or experiences which caused either high or low scores on individual SERVQUAL items.

Computers and medical information: an elective for fourth-year medical students.

The Computers and Medical Information elective is a collaborative effort to expose students to a variety of computer applications for medical information management. The course has a modular format so that students can work with a variety of people who are enthusiastic users of computer-based information systems. The elective emphasizes learning by doing. Faculty introduce concepts and systems and serve as guides in the use of systems. Students have rated the course positively and, after four years as an elective, some of the course's content has been integrated into the required curriculum.

Nonsteroidal anti-inflammatory drugs and necrotizing fasciitis.

The clinical features, etiology, and treatment of necrotizing fasciitis are reviewed, and the possible involvement of nonsteroidal anti-inflammatory drugs (NSAIDs) in the pathogenesis of this disease is discussed. Symptoms of necrotizing fasciitis include edema, erythema, warmth, and tenderness in the affected area, spreading rapidly to involve entire limbs or portions of the abdominal wall. Gangrene may develop, followed by multi-organ failure and death. The most common causative organisms are group A beta-hemolytic streptococci. Treatment includes tissue debridement, intravenous antibiotics, and supportive treatment with fluids and electrolytes. A number of case reports and articles in the lay press have suggested an association between the use of NSAIDs and the development of necrotizing fasciitis, although this association has not been substantiated in the scientific literature. Inhibition of the immune response has been proposed as an explanation for the reported association between necrotizing fasciitis and NSAIDs. NSAIDs should be administered with caution, if at all, to patients with inflammatory soft-tissue lesions, especially if concurrent infection is likely.

Predictors of lottery gambling among American college students.

In this study lottery gambling behavior of 288 American college students was examined. Although most students were infrequent gamblers, we found that student lottery gambling was related to having parents and friends who were lottery gamblers. Students who were frequent lottery gamblers were more likely to participate in other forms of gambling and to have begun gambling at younger ages than less frequent gamblers. Locus of control was related to more frequent gambling among parents and only marginally related to more frequent lottery play among students. Discriminant analysis using parental gambling, peer gambling, games played, sex, and locus of control could predict frequency of lottery playing for 72% of gamblers and nongamblers.

Making faces: posed facial expression, self-competence, and personality.

This study examined the relationships between posed facial expression, childrens' perceived self-competence, and teachers' perceptions of competence. Third- and fifth-grade children completed the Self-Perception Profile for Children, the Eysenck Personality Questionnaire, and the Junior Self-Monitoring Scale for Children. Individual differences in posing accuracy were determined with a videotaped acting task. Children who were more able to produce prototypical expressions obtained higher teacher ratings of academic competence; however, posing ability bore little relationship to children's self-competence. Gender differences in feelings of self-competence, but not in sending ability, were observed. Extraversion and self-monitoring were unrelated to ability to pose emotional expressions.

A comparison of low dose methotrexate bioavailability: oral solution, oral tablet, subcutaneous and intramuscular dosing.

OBJECTIVE: To compare the relative bioavailability of low dose methotrexate (MTX) administered as tablet, oral solution, and subcutaneous (sc) injection to that of intramuscular (im) injection in patients with rheumatoid arthritis (RA). METHODS: Twelve patients meeting the American College of Rheumatology criteria for RA had serial blood MTX concentration samples drawn over a 24-h period after receiving their normal weekly MTX dose. Relative bioavailability (F) of the tablet and oral solution formulations was determined by comparison of the area under the time-versus-serum-concentration curves (AUC) for the 2 different oral formulations as a percentage of the AUC for im injection. Also, relative bioavailability of the sc formulation was compared to im in 6 of the patients. RESULTS: Mean F for the oral tablet was 0.85, while that for the oral solution was 0.87. Both oral formulations showed a statistically significant difference in mean F when compared to im (tablet vs im, p = 0.002, oral solution vs im, p = 0.009). No statistically significant difference, however, was found in mean relative bioavailability between tablet and solution (p = 0.744). The mean F for sc was 0.97; no statistically significant difference existed between the mean F values for the sc and im routes of administration (p = 0.657). CONCLUSIONS: Our data suggest the oral solution may be substituted for tablet dosing and sc injection substituted for im. Thus, a variety of different dosing methodologies may be considered providing the most appropriate route in each patient, given issues of compliance, medication cost, and preference.

Participants in school-sponsored and independent sports: perceptions of self and family.

Sports are believed to contribute to physical well-being, social adjustment, and self-esteem. In this study, perceptions of social competence and family dynamics were examined among adolescent participants in school-sponsored and independent sports (baseball and skateboarding). Subjects, aged 12 to 19 years, completed a questionnaire consisting of FACES III, a social competence scale, and miscellaneous items concerning school performance, sports commitment, and perceptions of adult attitudes. Perceptions of social competence were differentially related to degree of sports involvement and perceived skill but were not related to the social acceptability of the sport. Adolescents in both groups depicted their families as demonstrating low levels of cohesion but high adaptability.

Soluble aluminum silicates: stoichiometry, stability, and implications for environmental geochemistry.

Soluble aluminum silicate (Al-Si) complexes are critical species for the development and application of geochemical models. A fluorescence probe technique was used to show that Al-Si complexes account for up to 95% of the total inorganic mononuclear Al in natural waters. The presence of these soluble Al-Si species affects the solubility of Al-Si minerals. Soluble Al-Si species may be important intermediates in the weathering reactions of primary Al-Si minerals and should be considered in dissolution models. Soluble Al-Si species may be key components controlling the formation of metastable and new stable minerals during interactions between water and rocks or soils.

Clindamycin, erythromycin, and the newer macrolides.

Clindamycin continues to be an important agent for the management of infections due to gram-positive cocci and anaerobes. Such pathogens are frequently important in skin, soft tissue, and deep infections of the foot. Erythromycin has an impressive safety record and has retained its activity against many organisms, including several that play a role in infections of the foot. Clindamycin and erythromycin are frequently used as alternatives to the penicillins and cephalosporins. Newer macrolides, in comparison to erythromycin, have similar antimicrobial spectra of activity, improved pharmacokinetic parameters, and better tissue penetration. As new microorganisms emerge as clinical problems, newer macrolides may play a therapeutic role.