Disruption of Tephra Fall Deposits Caused by Lava Flows during Basaltic Eruptions

Observations in the USA, Iceland and Tenerife, Canary Islands reveal how processes occurring during basaltic eruptions can result in complex physical and stratigraphic relationships between lava and proximal tephra fall deposits around vents. Observations illustrate how basaltic lavas can disrupt, dissect (spatially and temporally) and alter sheet-form fall deposits. Complexity arises through synchronous and alternating effusive and explosive activity that results in intercalated lavas and tephra deposits. Tephra deposits can become disrupted into mounds and ridges by lateral and vertical displacement caused by movement (including inflation) of underlying pāhoehoe lavas and clastogenic lavas. Mounds of tephra can be rafted away over distances of 100 s to 1,000 s m from proximal pyroclastic constructs on top of lava flows. Draping of irregular topography by fall deposits and subsequent partial burial of topographic depressions by later lavas can result in apparent complexity of tephra layers. These processes, deduced from field relationships, have resulted in considerable stratigraphic complexity in the studied proximal regions where fallout was synchronous or alternated with inflation of subjacent lava sheets. These mechanisms may lead to diachronous contact relationships between fall deposits and lava flows. Such complexities may remain cryptic due to textural and geochemical quasi-homogeneity within sequences of interbedded basaltic fall deposits and lavas. The net effect of these processes may be to reduce the usefulness of data collected from proximal fall deposits for reconstructing basaltic eruption dynamics

Exploratory Factor Analysis of the Trauma Symptom Checklist for Children: A Comparison of Two Factor Extraction Methods

INTRODUCTION: Assessment tools that demonstrate adequate construct validity are needed to identify youth at risk of developing posttraumatic stress symptoms (PTSS) so these at risk youth can be referred to appropriate resources such as counseling. Research on the construct validity of instruments designed to measure PTSS have not shown a consistent factor structure of PTSS. Furthermore, the factor structure of PTSS measured using the Trauma Symptom Checklist for Children (TSCC), a widely used instrument, have only been studied using principal component analysis (PCA), a data reduction technique, rather than exploratory factor analysis (EFA), a factor analytic technique. AIM: The present study aims to 1) evaluate the construct validity of the TSCC using EFA, and 2) demonstrate differences in factor solutions extracted using EFA and PCA. METHODS: A secondary data analysis was conducted on a sample of 121 adolescents exposed to community violence in a mid-sized southern city. Two factor analyses were conducted on the sample using EFA and PCA. RESULTS: Using EFA, PTSS measured by the TSCC demonstrated a three factor structure. The factors were named the Posttraumatic Stress factor, Fear factor, and Sexual Concerns factor. Using PCA, five less interpretable components were extracted. DISCUSSION: The factor structure of PTSS measured by the TSCC differed from currently proposed factor solutions in the PTSS literature, lending evidence that more EFA work is necessary to determine the factor structure of PTSS. As expected, there were also differences between the factor solutions produced using the two different analytic techniques. Future research is needed to confirm this factor solution in larger, more diverse samples

Marginal Cost Analysis of Two Train-the-Trainer Models for Implementing SafeCare

[West J Emerg Med. 2014;15(5):623–626.

A Screening tool for Identification of Victims of Commercial Sexual Exploitation of Children

Background: Commercial sexual exploitation of children (CSEC) and sex trafficking have only recently been recognized as problems by healthcare providers. Both UNICEF (2014) and the Institute of Medicine (2013) have stressed the need for systematic research to assist healthcare providers in the identification of victims. The aim of this poster is to describe initial findings relating to the development of a screening tool to identify CSEC victims. Methods: Twenty-seven sites nationwide (e.g., emergency departments and specialized clinics) participated in a study to validate a screening tool for identifying CSEC victims in an outpatient setting. The study was conducted under approval from the Institutional Review Board at Children’s Healthcare of Atlanta. Inclusion criteria for the study generally involved being an English-speaking adolescent aged 11-18 years. Results: Study enrollment is ongoing. Preliminary data for 210 youth were analyzed for this abstract. The sample was diverse with respect to age (M=14.59 years, SD=1.490 years) and ethnicity (56.4% Caucasian, 31.8% African American, 3.9% mixed race, and 7.8% Hispanic); the sample was predominantly female (92.8%). Of the 210 youth in the sample, 115(54.8%) have had sex. Of these 115 youth, 13(11.3%) have traded sex for money, drugs, or housing; 7(58.3%) of 12(10.4%) complied when asked by someone to have sex with another person; 8(61.5%) of 13(11.3%) performed sexual acts in public when propositioned; and 19(45.2%) of 42(36.5%) shared provocative photos when prompted. Medical providers flagged 14 youth (6.7% of total 210) as potential CSEC victims. Conclusions: The screening tool shows promise for effective identification of CSEC victims. This poster will present additional data and further quantitative analyses exploring the influences of sexual behavior, drug and alcohol use, and other factors on the risk of becoming a CSEC victim. Implications for researchers and clinicians will also be discussed

Veterinary students' views on animal patiens and human clients, using Q methodology

Veterinarians serve two masters: animal patients and human clients. Both animal patients and human clients have legitimate interests, and conflicting moral claims may flow from these interests. Earlier research concludes that veterinary students are very much aware of the complex and often paradoxical relationship they have and will have with animals. In this article the views of veterinary students about their anticipated relationship with animal patients and human clients are studied. The main part of the article describes discourses of first-year and fourth-year students about their (future) relationship with animals and their caretakers, for which Q-methodology is used. At the end of the article, the discourses are related to the students' gender and their workplace preferences. © 2007 AAVMC

Relations Among Gender, Violence Exposure, and Mental Health: The National Survey of Adolescents

Using a nationally representative sample of 4,008 adolescents, this study examines gender differences in violence exposure, major depressive episode (MDE) and posttraumatic stress disorder (PTSD), and characteristics of violence incidents. It was hypothesized that there would be gender differences in the types of violence exposure reported as well as the prevalence of MDE and PTSD; and that gender would moderate the relationship between violence exposure and mental health outcomes. Results indicated significant gender differences in rates of violence exposure, PTSD and MDE. Additionally, gender was a moderating variable in the relation between sexual assault and PTSD, but not in the other violence exposure-mental health relations examined. It thus appears that the pathways for developing PTSD may be different for male and female victims of sexual abuse. Implications for interventions and future research are discussed

Effects of Exposure to Community Violence and Family Violence on School Functioning Problems among Urban Youth: The Potential Mediating Role of Posttraumatic Stress Symptoms

Adolescents who are exposed to violence during childhood are at an increased risk for developing posttraumatic stress (PTS) symptoms. The literature suggests that violence exposure might also have negative effects on school functioning, and that PTS might serve as a potential mediator in this association. The purpose of the current study was to replicate and extend prior research by examining PTS symptoms as a mediator of the relationship between two types of violence exposure and school functioning problems among ado- lescent youth from an urban setting. Participants included a sample of 121 junior high and high school students (M = 15 years; range = 13–16 years; 60 males, 61 females) within high-crime neighborhoods. Consistent with our hypotheses, community violence and fam- ily violence were associated with PTS symptoms and school functioning problems. Our data suggest that community and family violence were indirectly related to school func- tioning problems through PTS symptoms. Findings from this study demonstrate that PTS symptoms potentially mediate the relationship between violence exposure and school functioning problems across two settings (community and home). Future research should further examine protective factors that can prevent youth violence exposure as well as negative outcomes related to violence

Assessing eruption column height in ancient flood basalt eruptions

A buoyant plume model is used to explore the ability of flood basalt eruptions to inject climate-relevant gases into the stratosphere. An example from the 1986 Izu-Oshima basaltic fissure eruption validates the model's ability to reproduce the observed maximum plume heights of 12–16 km above sea level, sustained above fire-fountains. The model predicts maximum plume heights of 13–17 km for source widths of between 4–16 m when 32% (by mass) of the erupted magma is fragmented and involved in the buoyant plume (effective volatile content of 6 wt%). Assuming that the Miocene-age Roza eruption (part of the Columbia River Basalt Group) sustained fire-fountains of similar height to Izu-Oshima (1.6 km above the vent), we show that the Roza eruption could have sustained buoyant ash and gas plumes that extended into the stratosphere at ∼45°N. Assuming 5 km long active fissure segments and 9000 Mt of SO2 released during explosive phases over a 10–15 year duration, the ∼180km of known Roza fissure length could have supported ∼36 explosive events/phases, each with a duration of 3–4 days. Each 5 km fissure segment could have emitted 62 Mt of SO2 per day into the stratosphere while actively fountaining, the equivalent of about three 1991 Mount Pinatubo eruptions per day. Each fissure segment could have had one to several vents, which subsequently produced lava without significant fountaining for a longer period within the decades-long eruption. Sensitivity of plume rise height to ancient atmospheric conditions is explored. Although eruptions in the Deccan Traps (∼66Ma) may have generated buoyant plumes that rose to altitudes in excess of 18 km, they may not have reached the stratosphere because the tropopause was substantially higher in the late Cretaceous. Our results indicate that some flood basalt eruptions, such as Roza, were capable of repeatedly injecting large masses of SO2 into the stratosphere. Thus sustained flood basalt eruptions could have influenced climate on time scales of decades to centuries but the location (i.e., latitude) of the province and relevant paleoclimate is important and must be considered

Using Combined Morphological, Allometric and Molecular Approaches to Identify Species of the Genus Raillietiella (Pentastomida)

Taxonomic studies of parasites can be severely compromised if the host species affects parasite morphology; an uncritical analysis might recognize multiple taxa simply because of phenotypically plastic responses of parasite morphology to host physiology. Pentastomids of the genus Raillietiella are endoparasitic crustaceans primarily infecting the respiratory system of carnivorous reptiles, but also recorded from bufonid anurans. The delineation of pentastomids at the generic level is clear, but the taxonomic status of many species is not. We collected raillietiellids from lungs of the invasive cane toad (Rhinella marina), the invasive Asian house gecko (Hemidactylus frenatus), and a native tree frog (Litoria caerulea) in tropical Australia, and employed a combination of genetic analyses, and traditional and novel morphological methods to clarify their identity. Conventional analyses of parasite morphology (which focus on raw values of morphological traits) revealed two discrete clusters in terms of pentastome hook size, implying two different species of pentastomes: one from toads and a tree frog (Raillietiella indica) and another from lizards (Raillietiella frenatus). However, these clusters disappeared in allometric analyses that took pentastome body size into account, suggesting that only a single pentastome taxon may be involved. Our molecular data revealed no genetic differences between parasites in toads versus lizards, confirming that there was only one species: R. frenatus. This pentastome (previously known only from lizards) clearly is also capable of maturing in anurans. Our analyses show that the morphological features used in pentastomid taxonomy change as the parasite transitions through developmental stages in the definitive host. To facilitate valid descriptions of new species of pentastomes, future taxonomic work should include both morphological measurements (incorporating quantitative measures of body size and hook bluntness) and molecular data