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A new cytotoxicity assay for brevetoxins using fluorescence microscopy.


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A new cytotoxicity assay for brevetoxins using fluorescence microscopy.

Mar Drugs. 2014 Sep;12(9):4868-82

Authors: McCall JR, Elliott EA, Bourdelais AJ

Abstract
Brevetoxins are a family of ladder-framed polyether toxins produced during blooms of the marine dinoflagellate, Karenia brevis. Consumption of shellfish or finfish exposed to brevetoxins can lead to the development of neurotoxic shellfish poisoning. The toxic effects of brevetoxins are believed to be due to the activation of voltage-sensitive sodium channels in cell membranes. The traditional cytotoxicity assay for detection of brevetoxins uses the Neuro-2A cell line, which must first be treated with the neurotoxins, ouabain and veratridine, in order to become sensitive to brevetoxins. In this study, we demonstrate several drawbacks of the Neuro-2A assay, which include variability for the EC50 values for brevetoxin and non-linear triphasic dose response curves. Ouabain/ veratridine-treated Neuro-2A cells do not show a typical sigmoidal dose response curve in response to brevetoxin, but rather, have a polynomial shaped curve, which makes calculating EC50 values highly variable. We describe a new fluorescence live cell imaging model, which allows for accurate calculation of cytotoxicity via nuclear staining and additional measurement of other viability parameters depending on which aspect of the cell is stained. In addition, the SJCRH30 cell line shows promise as an alternative to Neuro-2A cells for testing brevetoxins without the need for ouabain and veratridine.

PMID: 25251033 [PubMed - indexed for MEDLINE]

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Sedimentary proxy evidence of a mid-Holocene hypsithermal event in the location of a current warming hole, North Carolina, USA


Publication date: March 2015
Source:Quaternary Research, Volume 83, Issue 2

Author(s): Benjamin R. Tanner, Chad S. Lane, Elizabeth M. Martin, Robert Young, Beverly Collins

A wetland deposit from the southern Appalachian mountains of North Carolina, USA, has been radiocarbon dated and shows continuous deposition from the early Holocene to the present. Non-coastal records of Holocene paleoenvironments are rare from the southeastern USA. Increased stable carbon isotope ratios (δ13C) of sedimentary organic matter and pollen percentages indicate warm, dry early- to mid-Holocene conditions. This interpretation is also supported by n-alkane biomarker data and bulk sedimentary C/N ratios. These warm, dry conditions coincide with a mid-Holocene hypsithermal, or altithermal, documented elsewhere in North America. Our data indicate that the southeastern USA warmed concurrently with much of the rest of the continent during the mid-Holocene. If the current “warming hole” in the southeastern USA persists, during a time of greenhouse gas-induced warming elsewhere, it will be anomalous both in space and time.





Chemical analysis of Karenia papilionacea


Publication date: July 2015
Source:Toxicon, Volume 101

Author(s): Nicholas Fowler, Carmelo Tomas, Daniel Baden, Lisa Campbell, Andrea Bourdelais

One of the most widely studied organisms responsible for Harmful Algal Blooms (HABs) is the marine dinoflagellate Karenia brevis. This organism produces neurotoxic compounds known as brevetoxins. A related dinoflagellate, Karenia papilionacea, has been reported to occasionally co-bloom with K. brevis but has received little attention as a possible toxin producing species. Therefore, our aim was to investigate the toxin profile for K. papilionacea. A toxic fraction was identified using a cell based cytotoxicity assay and the toxin was isolated and identified as the ladder frame polyether brevetoxin-2 (PbTx-2) using mass spectrometry (MS) and nuclear magnetic resonance (NMR). Toxin production in K. papilionacea increased in response to hypoosmotic stress, as previously observed in K. brevis.





A Phase 3 Trial of 2 Years of Androgen Suppression and Radiation Therapy With or Without Adjuvant Chemotherapy for High-Risk Prostate Cancer: Final Results of Radiation Therapy Oncology Group Phase 3 Randomized Trial NRG Oncology RTOG 9902


Publication date: Available online 21 July 2015
Source:International Journal of Radiation Oncology*Biology*Physics

Author(s): Seth A. Rosenthal, Daniel Hunt, A. Oliver Sartor, Kenneth J. Pienta, Leonard Gomella, David Grignon, Raghu Rajan, Kevin J. Kerlin, Christopher U. Jones, Michael Dobelbower, William U. Shipley, Kenneth Zeitzer, Daniel A. Hamstra, Viroon Donavanik, Marvin Rotman, Alan C. Hartford, Jeffrey Michalski, Michael Seider, Harold Kim, Deborah A. Kuban, Jennifer Moughan, Howard Sandler

Purpose Long-term (LT) androgen suppression (AS) with radiation therapy (RT) is a standard treatment of high-risk, localized prostate cancer (PCa). Radiation Therapy Oncology Group 9902 was a randomized trial testing the hypothesis that adjuvant combination chemotherapy (CT) with paclitaxel, estramustine, and oral etoposide plus LT AS plus RT would improve overall survival (OS). Methods and Materials Patients with high-risk PCa (prostate-specific antigen 20-100 ng/mL and Gleason score [GS] ≥7 or clinical stage ≥T2 and GS ≥8) were randomized to RT and AS (AS + RT) alone or with adjuvant CT (AS + RT + CT). CT was given as four 21-day cycles, delivered beginning 28 days after 70.2 Gy of RT. AS was given as luteinizing hormone-releasing hormone for 24 months, beginning 2 months before RT plus an oral antiandrogen for 4 months before and during RT. The study was designed based on a 6% improvement in OS from 79% to 85% at 5 years, with 90% power and a 2-sided alpha of 0.05. Results A total of 397 patients (380 eligible) were randomized. The patients had high-risk PCa, 68% with GS 8 to 10 and 34% T3 to T4 tumors, and median prostate-specific antigen of 22.6 ng/mL. The median follow-up period was 9.2 years. The trial closed early because of excess thromboembolic toxicity in the CT arm. The 10-year results for all randomized patients revealed no significant difference between the AS + RT and AS + RT + CT arms in OS (65% vs 63%; P=.81), biochemical failure (58% vs 54%; P=.82), local progression (11% vs 7%; P=.09), distant metastases (16% vs 14%; P=.42), or disease-free survival (22% vs 26%; P=.61). Conclusions NRG Oncology RTOG 9902 showed no significant differences in OS, biochemical failure, local progression, distant metastases, or disease-free survival with the addition of adjuvant CT to LT AS + RT. The trial results provide valuable data regarding the natural history of high-risk PCa treated with LT AS + RT and have implications for the feasibility of clinical trial accrual and tolerability using CT for PCa.





A76 Inequalities in the distribution of primary care providers: Comparing healthcare disparity among urban and rural Floridian


Publication date: June 2015
Source:Journal of Transport & Health, Volume 2, Issue 2, Supplement

Author(s): Ruth Steiner, Ilir Bejleri, Donna Neff, Jeff Harman, Barbara Lutz, Sulhee Yoon, Michael Bumbach

Background Many economics, sociology, and urban planning researchers have assessed regional inequalities, especially for those populations affected by socioeconomic factors such as low income and unemployment status. Inequalities regarding health and its providers have been documented in the last few decades. In 2010, the Department of Human and Health Service (DHHS) launched the Healthy People 2020 movement with goals to eliminate health inequality/disparity and to encourage healthy development. According to the DHHS, health disparity is defined as “a particular type of health difference that is closely linked with physical distance to service, social, economic, and/or environmental disadvantage”. Health disparity that results from the limited access to healthcare facilities is believed to be associated with the unequal distribution of resources and opportunities such as healthcare service, physical activity facilities, and healthy food. However, empirical studies are insufficient for understanding the extent and magnitude of health disparities in the United States. This study seeks to use the inequality of distribution of healthcare providers as a measure for spatial health disparities in urban and rural areas (AIM1) while also monitoring socioeconomic characteristics of the populations in said areas (AIM2). Methods For the first aim, this study will calculate the population per physician ratio for each urban and rural census tract boundary in Florida. The Gini coefficient and Lorenz curve are used to measure the sufficiency or the insufficiency of physician distribution for each urban and rural Florida. These measures are designed to analyze inequality of income or wealth, but they also have been used to study the distribution of health resources such as physician distribution. Second, this study will use Hot Spot Analysis in Geographic Information System (GIS) to calculate the Getis-Ord GI statistic to identify patterns of disadvantaged socioeconomic populations. Cluster areas with high or low densities of certain socioeconomic characteristics, hot spots, will be determined. Results Preliminary results present that primary care physicians in both urban and rural areas of Florida were unevenly distributed. The Gini coefficient for the distribution of primary care physicians in urban Florida was 0.49 (SD=0.0001), while that of the rural Florida was 0.38 (SD=0.01). Conclusions The inequality in the distribution of primary care physicians was higher in urban areas compared with that of the rural Florida. For this purpose, the availability (number) of physicians could be adjusted depending on socioeconomic factors.





Elementary preservice teachers׳ navigation of racism and whiteness through inquiry with historical documentary film


Publication date: Available online 9 July 2015
Source:The Journal of Social Studies Research

Author(s): Lisa Brown Buchanan

This descriptive case study explores how on cohort of 17 White elementary preservice teachers examined counter-narratives of racism and Whiteness in selected documentary films using a historical inquiry approach. Findings indicate that by joining documentary film and historical inquiry in elementary social studies education, teacher educators can foster preservice teachers׳ engagement with perspective recognition while developing historical content knowledge. This study also documents White preservice teachers׳ acceptance of racism and resistance towards unpacking their White privilege and racism as status quo. Implications for using this approach with preservice teachers and the dilemma of White avoidance in social studies education are discussed.





Modified fully discretized projection method for the incompressible Navier–Stokes equations


Publication date: October 2015
Source:Applied Numerical Mathematics, Volume 96

Author(s): Daniel X. Guo

The stability and convergence of a second-order fully discretized projection method for the incompressible Navier–Stokes equations is studied. In order to update the pressure field faster, modified fully discretized projection methods are proposed. It results in a nearly second-order method. This method sacrifices a little of accuracy, but it requires much less computations at each time step. It is very appropriate for actual computations. The comparison with other methods for the driven-cavity problem is presented.





SBIRT Implementation for Adolescents in Urban Federally Qualified Health Centers


Publication date: Available online 26 June 2015
Source:Journal of Substance Abuse Treatment

Author(s): Shannon Gwin Mitchell, Robert P. Schwartz, Arethusa S. Kirk, Kristi Dusek, Marla Oros, Colleen Hosler, Jan Gryczynski, Carolina Barbosa, Laura Dunlap, David Lounsbury, Kevin E. O’Grady, Barry S. Brown

Background Alcohol, tobacco, and other drug use remains highly prevalent among US adolescents and is a threat to their well-being and to the public health. Clinical trials and meta-analyses evidence supports the effectiveness of Screening, Brief Intervention and Referral to Treatment (SBIRT) for adolescents with substance misuse but primary care providers have been slow to adopt this evidence-based approach. The purpose of this paper is to describe the theoretically informed methodology of an on-going implementation study. Methods This study protocol is a multi-site, cluster randomized trial (N = 7) guided by Proctor’s conceptual model of implementation research and comparing two principal approaches to SBIRT delivery within adolescent medicine: Generalist vs. Specialist. In the Generalist Approach, the primary care provider delivers brief intervention (BI) for substance misuse. In the Specialist Approach, BIs are delivered by behavioral health counselors. The study will also examine the effectiveness of integrating HIV risk screening within an SBIRT model. Implementation Strategies employed include: integrated team development of the service delivery model, modifications to the electronic medical record, regular performance feedback and supervision. Implementation outcomes, include: Acceptability, Appropriateness, Adoption, Feasibility, Fidelity, Costs/Cost-Effectiveness, Penetration, and Sustainability. Discussion The study will fill a major gap in scientific knowledge regarding the best SBIRT implementation strategy at a time when SBIRT is poised to be brought to scale under health care reform. It will also provide novel data to inform the expansion of the SBIRT model to address HIV risk behaviors among adolescents. Finally, the study will generate important cost data that offers guidance to policymakers and clinic directors about the adoption of SBIRT in adolescent health care.





Couple similarity on stimulus characteristics and marital satisfaction


Publication date: November 2015
Source:Personality and Individual Differences, Volume 86

Author(s): Darren George, Shanhong Lou, Jared Webb, Jennifer Pugh, Alan Martinez, Jeremy Foulston

Murstein's (1970) “stimulus–value–role” theory suggests that mate selection consists of three stages. At each stage people seek different types of information. This study extends previous research on couple similarity by focusing on the “stimulus” stage where people attend to stimulus information—the most salient personal information. This stage has received less attention than the “value” and “role” stages. A sample of 641 married couples from Central Alberta, Canada provided information on a wide range of stimulus characteristics including background, physical and perceptual variables, as well as spirituality and growth orientation for comparison. Correlation results showed evidence for strong and consistent couple similarity on stimulus characteristics, suggesting that those characteristics are important domains to partner selection. Structural equation modeling results indicated that couple similarity (measured by absolute and directional difference score) overall was not a strong predictor of marital satisfaction; however, discrepancies in age, spirituality, and growth orientation were significant predictors of dissatisfaction.





Climate-induced change of environmentally defined floristic domains: A conservation based vulnerability framework


Publication date: September 2015
Source:Applied Geography, Volume 63

Author(s): Debbie Jewitt, Barend F.N. Erasmus, Peter S. Goodman, Timothy G. O'Connor, William W. Hargrove, Damian M. Maddalena, Ed. T.F. Witkowski

Global climate change is having marked influences on species distributions, phenology and ecosystem composition and raises questions as to the effectiveness of current conservation strategies. Conservation planning has only recently begun to adequately account for dynamic threats such as climate change. We propose a method to incorporate climate-dynamic environmental domains, identified using specific environmental correlates of floristic composition, into conservation strategies, using the province of KwaZulu-Natal, South Africa as a case study. The environmental domains offer an approach to conservation that conserves diversity under current and future climates, recognising that the species constituting diversity may change through time. We mapped current locations of domains by identifying their positions in a multi-dimensional environmental space using a non-hierarchical iterative k-means clustering algorithm. Their future locations were explored using an ensemble of future climate scenarios. The HadCM2 and GFDL2.1 models represented the extreme ranges of the models. The magnitude of change in each environmental domain was calculated using Euclidean distances to determine areas of greatest and least stability for each future climate projection. Domains occurring in the savanna biome increase at the expense of domains occurring in the grassland biome, which has significant negative consequences for the species rich grasslands. The magnitude of change maps represents areas of changed climatic conditions or edaphic disjunctions. The HadCM2 model predicted the greatest overall magnitude of change across the province. Species with specific soil requirements may not be able to track changing climatic conditions. A vulnerability framework was developed that incorporated climatic stability and habitat intactness indices. The mean magnitude of change informed the potential speed of transition of domains between the vulnerability quadrants. The framework informs appropriate conservation actions to mitigate climate change impacts on biodiversity. The study explicitly links floristic pattern and climate variability and provides useful insights to facilitate conservation planning for climate change.
Graphical abstract




Demersal fish distribution and habitat use within and near Baltimore and Norfolk Canyons, U.S. middle Atlantic slope


Publication date: Available online 16 June 2015
Source:Deep Sea Research Part I: Oceanographic Research Papers

Author(s): Steve W. Ross, Mike Rhode, Andrea M. Quattrini

Numerous submarine canyons along the United States middle Atlantic continental margin support enhanced productivity, diverse and unique habitats, active fisheries, and are vulnerable to various anthropogenic disturbances. During two cruises (15 Aug-2 Oct 2012; 30 Apr-27 May 2013), Baltimore and Norfolk canyons and nearby areas (including two cold seeps) were intensively surveyed to determine demersal fish distributions and habitat associations. Overall, 34 ROV dives (234-1612m) resulted in 295 h of bottom video observations and numerous collections. These data were supplemented by 40, 30-min bottom trawl samples. Fish observations were assigned to five general habitat designations: 1) sand-mud (flat), 2) sloping sand-mud with burrows, 3) low profile gravel, rock, boulder, 4) high profile, canyon walls, rocks or ridges, and 5) seep-mixed hard and soft substrata, the later subdivided into seven habitats based on amounts of dead mussel and rock cover. The influence of corals, sponges and live mussels (seeps only) on fish distributions was also investigated. Both canyon areas supported abundant and diverse fish communities and exhibited a wide range of habitats, including extensive areas of deep-sea corals and sponges and two nearby methane seeps (380-430m, 1455-1610m). All methods combined yielded a total of 123 species of fishes, 12 of which are either new records for this region or have new range data. Depth was a major factor that separated the fish faunas into two zones with a boundary around 1400m. Fishes defining the deeper zone included Lycodes sp., Dicrolene introniger, Gaidropsaurus ensis, Hydrolagus affinis, Antimora rostrata, and Aldrovandia sp. Fishes in the deep zone did not exhibit strong habitat affinities, despite the presence of a quite rugged, extensive methane seep. We propose that habitat specificity decreases with increasing depth. Fishes in the shallower zone, characterized by Laemonema sp., Phycis chesteri, Nezumia bairdii, Brosme brosme, and Helicolenus dactylopterus, exhibited a variety of habitat use patterns. In general, fish assemblages in the soft substrata areas (dominated by P. chesteri, N. bairdii, Glyptocephalus cynoglossus, Lophius americanus, Merluccius albidus) were different from those in more complex habitats (dominated by Laemonema spp., Hoplostethus spp., B. brosme, Benthocometes robustus, L. americanus, Dysommina rugosa). Although, when present, the dense coral and sponge cover did not statistically affect general fish assemblage patterns in hard bottom habitats, these sessile organisms markedly increased habitat complexity, and some fish species exhibited close association with them. Fish species compositions in the two canyons were not substantially different from the surrounding slopes. However, the diversity of habitats within both the canyons and seeps exerted an important influence on assemblage structure. At least for some species (e.g., B. brosme) canyon and seep environments may be a refuge from intensive bottom fishing activities. We frequently observed evidence of commercial and recreational fishing activity (lost gear on bottom and fishing boats in the area) throughout the canyons and some resulting habitat damage. Conservation measures for the unique and more vulnerable areas (seep and coral habitats) are being considered.





Becoming the Parent of a Child With Life-Threatening Food Allergies


Publication date: July–August 2015
Source:Journal of Pediatric Nursing, Volume 30, Issue 4

Author(s): Susan Brantlee Broome, Barbara J. Lutz, Christa Cook

Food induced anaphylaxis (FIA) is a serious medical event and managing it can place tremendous mental, emotional and financial burdens on parents of children with FIA. Using grounded theory methods, the experiences of parents caring for a child with FIA and the adjustments and strategies used to effectively manage a child's diagnosis were examined. Findings revealed once a child is diagnosed with FIA, parental competency is often severely challenged, calling into question parents' ability to succeed in the parenting role. To regain parental competency, parents engage in a 3 phase process to learn how to parent a child with FIA.





A comprehensive assessment of mercury exposure in penguin populations throughout the Southern Hemisphere: Using trophic calculations to identify sources of population-level variation


Publication date: Available online 11 June 2015
Source:Marine Pollution Bulletin

Author(s): Rebecka L. Brasso, André Chiaradia, Michael J. Polito, Andrea Raya Rey, Steven D. Emslie

The wide geographic distribution of penguins (Order Sphenisciformes) throughout the Southern Hemisphere provided a unique opportunity to use a single taxonomic group as biomonitors of mercury among geographically distinct marine ecosystems. Mercury concentrations were compared among ten species of penguins representing 26 geographically distinct breeding populations. Mercury concentrations were relatively low (⩽2.00ppm) in feathers from 18/26 populations considered. Population-level differences in trophic level explained variation in mercury concentrations among Little, King, and Gentoo penguin populations. However, Southern Rockhopper and Magellanic penguins breeding on Staten Island, Tierra del Fuego, had the highest mercury concentrations relative to their conspecifics despite foraging at a lower trophic level. The concurrent use of stable isotope and mercury data allowed us to document penguin populations at the greatest risk of exposure to harmful concentrations of mercury as a result of foraging at a high trophic level or in geographic ‘hot spots’ of mercury availability.





The diversification of developmental biology


Publication date: October 2015
Source:Studies in History and Philosophy of Science Part C: Studies in History and Philosophy of Biological and Biomedical Sciences, Volume 53

Author(s): Nathan Crowe, Michael R. Dietrich, Beverly S. Alomepe, Amelia F. Antrim, Bay Lauris ByrneSim, Yi He

In the 1960s, “developmental biology” became the dominant term to describe some of the research that had previously been included under the rubrics of embryology, growth, morphology, and physiology. As scientific societies formed under this new label, a new discipline took shape. Historians, however, have a number of different perspectives on what changes led to this new field of developmental biology and how the field itself was constituted during this period. Using the General Embryological Information Service, a global index of post-World War II development-related research, we have documented and visualized significant changes in the kinds of research that occurred as this new field formed. In particular, our analysis supports the claim that the transition toward developmental biology was marked by a growth in new topics and forms of research. Although many historians privilege the role of molecular biology and/or the molecularization of biology in general during this formative period, we have found that the influence of molecular biology is not sufficient to account for the wide range of new research that constituted developmental biology at the time. Overall, our work creates a robust characterization of the changes that occurred with regard to research on growth and development in the decades following World War II and provides a context for future work on the specific drivers of those changes.





Retrofitting with innovative stormwater control measures: Hydrologic mitigation of impervious cover in the municipal right-of-way


Publication date: August 2015
Source:Journal of Hydrology, Volume 527

Author(s): Jonathan L. Page, Ryan J. Winston, Dave B. Mayes, Christy Perrin, William F. Hunt

Impervious Cover (IC) has been shown to increase runoff volumes, peak discharges and pollutant loads to streams, which leads to degraded water quality and biological integrity. Stormwater Control Measures (SCMs) have been developed to mitigate the hydrologic and water quality impacts of urban areas and IC. This paired watershed study evaluated the impacts of SCM retrofits on hydrology for a small urban drainage area. In February 2012, a bioretention cell (BRC) street retrofit, four permeable pavement parking stalls and a tree filter device were installed to control and treat residential street runoff in Wilmington, North Carolina, USA. In the SCM-Retrofit catchment, 52% of the directly connected impervious area (DCIA) and 69% of the total drainage area was retrofitted for potential hydrologic mitigation. Underlying soils in the study area were urban sands. Peak discharge significantly decreased by 28%, while lag times in the catchment remained unchanged. Runoff depth significantly decreased by 52%. When compared to the control catchment, runoff depths in the SCM-Retrofit catchment were significantly less for events with low hourly rainfall intensities (<2.7mm/h), but significantly greater for events with high intensities (>7.4mm/h). During post-retrofit monitoring, runoff thresholds in the SCM-Retrofit and control catchments were 5.2mm and 3.5mm, respectively. The SCM-Retrofit runoff coefficient decreased from 0.38 to 0.18 and was substantially less than other runoff coefficients reported in the literature for conventional residential development. This study illustrated how a limited number of SCM retrofits installed within the public right-of-way can mitigate some of the hydrologic impacts of existing residential development.





GUVs Melt Like LUVs: The Large Heat Capacity of MLVs Is Not Due to Large Size or Small Curvature


Publication date: 2 June 2015
Source:Biophysical Journal, Volume 108, Issue 11

Author(s): Mark A. Kreutzberger, Emmanuel Tejada, Ying Wang, Paulo F. Almeida

The excess heat capacity functions (ΔC p ) associated with the main phase transition of large unilamellar vesicles (LUVs) and multilamellar vesicles (MLVs) are very different. Two explanations are possible. First, the difference in vesicle size (curvature) results in different gel-fluid interactions in the membrane; those interactions have a large effect on the cooperativity of the phase transition. Second, there is communication between the bilayers in an MLV when they undergo the gel-fluid transition; this communication results in thermodynamic coupling of the phase transitions of the bilayers in the MLV and, consequently, in an apparent increase in the cooperativity of the transition. To test these hypotheses, differential scanning calorimetry was performed on giant unilamellar vesicles (GUVs) of pure dipalmitoylphosphatidylcholine. The ΔC p curve of GUVs was found to resemble that of the much smaller LUVs. The transition in GUVs and LUVs is much broader (half-width ∼1.5°C) than in MLVs (∼0.1°C). This similarity in GUVs and LUVs indicates that their size has little effect on gel-fluid interactions in the phase transition. The result suggests that coupling between the transitions in the bilayers of an MLV is responsible for their apparent higher cooperativity in melting.





Category coherence in children's inductive inferences with cross-classified entities


Publication date: July–September 2015
Source:Cognitive Development, Volume 35

Author(s): Simone P. Nguyen, Tess Chevalier

Items rarely belong to a single category, but rather can be cross-classified into many categories, each serving a very different basis for induction. Presently, little is known about how children determine which category to use for induction in cross-classification situations. This research examined the role of category coherence in children's and adults’ (N =329) inductive reasoning about cross-classified entities. In Study 1 and 2, participants were presented with a person who could be cross-classified into two categories, one coherent and the other incoherent. Category coherence is the extent to which members of a category and/or the properties of a category make sense together, given one's background knowledge. The results showed that by age 5 years, children are systematic in their use of coherence, tending to select the coherent category to inform their inference about the person. There is weaker evidence for 4-year-olds. Study 3 and 4 revealed that 4-year-olds have an appreciation for coherence in tasks of categorization. The results of Study 5 demonstrated 5-year-olds’ and adults’ tendency to use coherence when reasoning about cross-classified entities across different induction tasks. Overall, these results contribute to our emerging understanding of how and why children select some categories versus others during induction with cross-classified items.





Morphological and genetic analysis of the Coolia monotis species complex with the introduction of two new species, Coolia santacroce sp. nov. and Coolia palmyrensis sp. nov. (Dinophyceae)


Publication date: June 2015
Source:Harmful Algae, Volume 46

Author(s): Sarah Karafas, Robert York, Carmelo Tomas

The dinoflagellate genus Coolia Meunier is an important epi-benthic organism that is commonly found in association with other dinoflagellates known to cause ciguatera. Two closely related taxa, Coolia monotis and Coolia malayensis, make up the C. monotis species complex. In this study we introduce two new toxic species that should be included in that complex, Coolia palmyrensis Karafas, Tomas, York sp. nov. and Coolia santacroce Karafas, Tomas, York sp. nov., collected from the Palmyra Atoll in the Pacific Ocean and Saint Croix, US Virgin Islands, respectively. These two species can be distinguished morphologically by size, pore shape, pore density, and the relative size of the apical pore complex. The ITS1/5.8S/ITS2 and the D1/D2 regions of the LSU rDNA were used to provide molecular support of morphological observations using maximum likelihood and Bayesian analyses. Furthermore, C. palmyrensis and C. santacroce both showed cytotoxic effects on human derived cells in vitro.





Temporal and spatial variability of trace volatile organic compounds in rainwater


Publication date: September 2015
Source:Chemosphere, Volume 134

Author(s): Katherine M. Mullaugh, Joanna M. Hamilton, G. Brooks Avery, J. David Felix, Ralph N. Mead, Joan D. Willey, Robert J. Kieber

This study presents the first detailed concentration profile of trace VOCs in atmospheric waters. Analytes were detected and quantified in 111 unique rain events in Wilmington, NC, USA over a one-year period. Headspace solid phase microextraction was optimized for detection of these compounds at sub-nanomolar levels. Distinct seasonality in both the occurrence and concentration of compounds was observed with the lowest abundance occurring during low irradiance winter months. In contrast to other rainwater components studied at this location, VOCs did not show any correlation between rainfall amount and concentrations. There was significant spatial variation with regards to air-mass back-trajectory for methyfuran with higher concentrations observed in terrestrial events during the growing season. Air mass back trajectory also impacted CCl4 concentrations in rainwater with evidence of a possible oceanic input. However there was no significant impact of air-mass back-trajectory on the concentration of BTEX observed in rain indicating that storm origin is not the controlling factor driving concentrations of these analytes in precipitation. Members of the BTEX family did, however, have significant correlations with each other occurring in ratios aligned closely with ratios reported in the literature for gas-phase BTEX. Using available gas-phase data from locations with similar anthropogenic sources and Henry’s Law constants, calculated concentrations agreed with VOC levels found in Wilmington rain. Results of this study indicate local gas-phase scavenging is the major source of VOCs in rain and wet deposition is not an efficient removal mechanism (<0.1%) of VOCs from the atmosphere.