Identifying reference conditions and quantifying biological variability within benthic macroinvertebrate communities in perennial and non-perennial northern California streams.

Identification of minimally disturbed reference sites is a critical step in developing precise and informative ecological indicators. We tested procedures to select reference sites, and quantified natural variation (inter-site and -annual variability) among reference conditions using a macroinvertebrate data set collected from 429 mediterranean-climate stream reaches in the San Francisco Bay Area, California (USA). We determined that a landscape GIS-based stressor screen followed by a local field-based stressor screen effectively identified least-disturbed reference sites that, based on NMS ordination results, supported different biological communities than sites identified with only landscape (GIS) or local (field) stressors. An examination of least-disturbed reference sites indicated that inter-site variability was strongly associated with stream hydrology (i.e., perennial vs. non-perennial flow) and annual precipitation, which highlights the need to control for such variation when developing biological indicators through natural gradient modeling or using unique biological indicators for both non-perennial and perennial streams. Metrics were more variable among non-perennial streams, indicating that additional modeling may be needed to develop precise biological indicators for non-perennial streams. Among 192 sites sampled two to six times over the 8-year study period, the biological community showed moderate inter-annual variability, with the 100 point index of biotic integrity scores varying from 0 to 51 points (mean = 11.5). Variance components analysis indicated that inter-annual variability explained only a fraction (5-18 %) of the total variation when compared against site-level variation; thus efforts to understand causes of natural variation between sites will produce more precise and accurate biological indicators.

Living fast and dying of infection: host life history drives interspecific variation in infection and disease risk.

Parasite infections often lead to dramatically different outcomes among host species. Although an emerging body of ecoimmunological research proposes that hosts experience a fundamental trade-off between pathogen defences and life-history activities, this line of inquiry has rarely been extended to the most essential outcomes of host-pathogen interactions: namely, infection and disease pathology. Using a comparative experimental approach involving 13 amphibian host species and a virulent parasite, we test the hypothesis that 'pace-of-life' predicts parasite infection and host pathology. Trematode exposure increased mortality and malformations in nine host species. After accounting for evolutionary history, species that developed quickly and metamorphosed smaller ('fast-species') were particularly prone to infection and pathology. This pattern likely resulted from both weaker host defences and greater adaptation by parasites to infect common hosts. Broader integration between life history theory and disease ecology can aid in identifying both reservoir hosts and species at risk of disease-driven declines.

Development and validation of a macroinvertebrate index of biotic integrity (IBI) for assessing urban impacts to Northern California freshwater wetlands.

Despite California policies requiring assessment of ambient wetland condition and compensatory wetland mitigations, no intensive monitoring tools have been developed to evaluate freshwater wetlands within the state. Therefore, we developed standardized, wadeable field methods to sample macroinvertebrate communities and evaluated 40 wetlands across Northern California to develop a macroinvertebrate index of biotic integrity (IBI). A priori reference sites were selected with minimal urban impacts, representing a best-attainable condition. We screened 56 macroinvertebrate metrics for inclusion in the IBI based on responsiveness to percent urbanization. Eight final metrics were selected for inclusion in the IBI: percent three dominant taxa; scraper richness; percent Ephemeroptera, Odonata, and Trichoptera (EOT); EOT richness; percent Tanypodinae/Chironomidae; Oligochaeta richness; percent Coleoptera; and predator richness. The IBI (potential range 0-100) demonstrated significant discriminatory power between the reference (mean = 69) and impacted wetlands (mean = 28). It also declined with increasing percent urbanization (R (2) = 0.53, p < 0.005) among wetlands in an independent validation dataset (n = 14). The IBI was robust in showing no significant bias with environmental gradients. This IBI is a functional tool to determine the ecological condition at urban (stormwater and flood control ponds), as well as rural freshwater wetlands (stockponds, seasonal wetlands, and natural ponds). Biological differences between perennial and non-perennial wetlands suggest that developing separate indicators for these wetland types may improve applicability, although the existing data set was not sufficient for exploring this option.

A day at the beach while on tropical vacation: sun protection practices in a high-risk setting for UV radiation exposure.

OBJECTIVE: To conduct an assessment of levels of UV radiation (UVR) exposure and the range of sun protection behaviors of beachgoers at a popular vacation destination. DESIGN: Participants completed the sun habits survey prior to entry to the beach and completed an exit survey on leaving regarding their sun protection practices while at the beach. Ambient UVR was monitored using polysulfone dosimeters. SETTING: A popular beach for vacationers in Honolulu, Hawaii. MAIN OUTCOME MEASURES: Sun protection practices and UVR. RESULTS: Participants spent an average of 3 hours at the beach and received an estimated UVR dose of 10.4 standard erythemal doses. Latent class analysis identified 3 homogeneous classes with distinct characteristics and sun protection behaviors. Those in class 1 (unconcerned and at low risk) were at least risk of skin cancer, intended to tan, and used the least amount of sun protection. Those in class 2 (tan seekers) had the second highest risk of skin cancer, had the highest proportion of women, became sunburned easily, intended to tan, had used tanning beds in past 30 days, and had the highest proportion of sunscreen coverage and the least clothing coverage. Those in class 3 (concerned and protected) had the highest skin cancer risk, the highest proportion of clothing coverage and shade use, and were more likely to be residents of Hawaii. CONCLUSIONS: Beachgoers were exposed to 5 times the UVR dose required to result in erythema among unprotected fair-skinned populations. Latent class analysis was effective in identifying subgroups of beachgoers who would benefit from targeted, population-based interventions aimed at reducing skin cancer risks while enjoying outdoor leisure-time activities.

Sun protection practices of beachgoers using a reliable observational measure.

BACKGROUND: Skin cancer is the most prevalent form of cancer in the United States and is rising rapidly; however, most skin cancers are preventable. Compared to self-report, direct observational methodologies could be a more valid and reliable tool for assessing sun protective behaviors within a specific environment. PURPOSE: The aim of the study is to assess the sun protection practices of beachgoers using a reliable observational measure. METHODS: A systematic observation system for assessing sun protective behaviors among beachgoers was developed. Data were collected by 2 raters over 3 days using momentary ecological sampling methods. Individuals in a representative zone were assessed for head wear, upper body wear, sunglasses use, shade use, and gender. RESULTS: Over the 3 days, Observers A and B made 1,678 and 1,725 observations, respectively. Interrater reliability ranged from 0.77 to 0.99. Hats, sunglasses, shirts, and shade were all used by less than 30% of the population. Sun protection behaviors varied by time of day and cloud cover. CONCLUSIONS: A reliable, observational measure designed to assess population behavior at the setting level showed low use of sun protection practices among beachgoers. Test-retest reliability, the inclusion of low body protection, coding for age, and skin tone are recommended for future versions of this system.

Activating multi-ethnic youth for smoking prevention: design, baseline findings, and implementation of project SPLASH.

BACKGROUND: Achieving significant reductions in tobacco use by youth is an important challenge. There is a pressing need to develop and evaluate innovative strategies that stimulate youth involvement and are effective in multi-ethnic populations. This article describes an innovative tobacco prevention trial, and reports baseline characteristics of participants and findings about implementation of the curriculum. METHODS: The aim of Project SPLASH is to evaluate the impact of a school-based smoking prevention intervention that emphasizes active involvement of middle school students, on rates of smoking initiation and regular smoking in a multi-ethnic cohort of youth in Hawaii. Project SPLASH is a group randomized trial that compares a 2-year innovative intervention with a social influence prevention program, in 20 public schools in Hawaii. The main outcome is mean 30-day smoking prevalence rates. RESULTS: The response rate was 78.4%. Approximately 1 in 4 students had tried smoking and 30-day smoking prevalence at baseline was 8%. Intervention and control groups were comparable in terms of tobacco use, gender, ethnicity, behavioral, environmental, and psychosocial characteristics. Differences in ethnic identification, socio-economic status, acculturation, and involvement in prevention activities may be due to chance. The intervention was well implemented by teachers across both the intervention and control school classes. CONCLUSION: For this study, 20 schools in Hawaii with close to 4000 participating students were recruited. Student smoking behavior and curriculum implementation were comparable by group status. The intervention study has the potential to elucidate how youth respond to an intervention with student involvement that incorporates cognitive and social action components.

Validity of beachgoers' self-report of their sun habits.

OBJECTIVE: To examine the validity of beachgoers' self-reported sun protection and UV exposure using objective measures. DESIGN: Eighty-eight participants completed a brief survey when they arrived at the beach; their skin was swabbed for the presence of sunscreen, while an observer recorded their clothing worn to the beach and the presence of sunburn. On leaving the beach, an exit survey detailing activities and sun habits while on the beach was completed by the participants, follow-up sunscreen swabs were obtained, and sunburns were recorded. Clothing observations were made for a subgroup (n = 25) of participants during their beach stay. RESULTS: Most participants (38 [44%]) reported spending 2 to 3 hours at the beach, which was consistent with researcher observations (Spearman rank correlation, r = 0.75). Moderate to substantial agreement was achieved between reported use of sunscreen for the day and sunscreen swabs (kappa, 0.54, 0.70, and 0.72 for the face, legs, and arms, respectively). Participants' self-report of clothing worn to the beach had substantial agreement with researcher observation: kappa coefficients ranged from 0.63 for footwear to 0.77 for head wear. Agreement was variable for clothing worn while on the beach, with slight to fair agreement for sunglasses (kappa, 0.11) and footwear (kappa, 0.23) and substantial agreement for upper body clothing (kappa, 0.79). Agreement between self-reported and observed sunburn was consistently lower (kappa, 0.21, 0.33, and 0.39 for the face, legs, and arms, respectively), with participants reporting more sunburn on arrival than was observed. CONCLUSIONS: Overall, self-report measures of time outside, sunscreen use, and clothing worn demonstrated good criterion validity when compared with observation and sunscreen swabbing. Sunscreen swabbing proved an effective procedure for detecting sunscreen at a beach setting.

A noninvasive objective measure of sunscreen use and reapplication.

OBJECTIVES: To study whether a noninvasive swabbing technique can detect sunscreen use for up to 6 hours, and whether the technique can detect reapplication of sunscreen. METHODS: Thirty volunteer office workers were randomly assigned to have one of a variety of sunscreens applied using recommended application techniques, and half were randomly assigned to have sunscreen reapplied after 3 hours. Alcohol-based swabs were used to obtain a sample from participants' arm at 20 minutes, and hourly from 1 to 6 hours post-application. Absorption readings were analyzed using an UV-visible spectrophotometer. RESULTS: The swabbing technique was consistently able to distinguish the sunscreen from control swabs for up to 6 hours. The absorption readings between 20 minutes and 6 hours were significantly higher than control swabs. There were no differences between the group that had sunscreen reapplied and the group that did not. CONCLUSION: The sunscreen swabbing technique is an effective noninvasive method for detecting a variety of sunscreen products in adults over a 6-hour period. No differences in absorption readings were found with sunscreen reapplication. This procedure will be a useful adjunct to other objective measures of sun protection and UV radiation exposure, resulting in a more accurate picture of the sun protection habits of individuals.

Review of the trematode genus Ribeiroia (Psilostomidae): ecology, life history and pathogenesis with special emphasis on the amphibian malformation problem.

Trematodes in the genus Ribeiroia have an indirect life cycle involving planorbid snails as first intermediate hosts, fishes or amphibians as second intermediate hosts and birds or mammals as definitive hosts. Although rarely pathogenic in definitive hosts, Ribeiroia infection can cause severe pathology and mortality in snails and amphibians. This group of parasites has gained notoriety for its prominent rol in the recent rash of amphibian deformities in North America. Under some circumstances, these malformations may enhance parasite transmission by rendering infected amphibian hosts more susceptible to definitive host predators. However, increasing reports of malformations in North American amphibian populations emphasize the importance of understanding infection patterns. Here we review important aspects of the biology, ecology, life cycle and pathogenesis of parasites in the genus Ribeiroia and identify priorities for future research. Based on available morphological descriptions and preliminary molecular data, three species of Ribeiroia are recognized: R. ondatrae in the Americas, R. marini in the Caribbean and R. congolensis/C. lileta in Africa. We further evaluate the influence of abiotic and biotic factors in determining the intensity and prevalence of Ribeiroia infection and malformations in amphibians, highlighting the importance of habitat alteration and secondary factors (e.g. aquatic eutrophication, contaminants) in promoting infection. Although not a "new" parasite, Ribeiroia may have increased in range, prevalence, or intensity in recent years, particularly within amphibian hosts. Nevertheless, while much is known about this intriguing group of parasites, there remains much that we do not know. Particular importance for future research is placed on the following areas: evaluating the phylogenetic position of the genus, establishing the molecular mechanism of parasite-induced malformations in amphibians, isolating the drivers of parasite transmission under field conditions and studying the consequences of malformations for parasite and host populations. Investigation of these questions will benefit enormously from a multidisciplinary approach that effectively integrates parasitology, developmental biology, immunology, herpetology and aquatic ecology.