Showing papers by "University of North Carolina at Wilmington published in 2014"

Ecologists should not use statistical significance tests to interpret simulation model results

Abstract: Simulation models are widely used to represent the dynamics of ecological systems. A common question with such models is how changes to a parameter value or functional form in the model alter the results. Some authors have chosen to answer that question using frequentist statistical hypothesis tests (e.g. ANOVA). �怀is is inappropriate for two reasons. First, p-values are determined by statistical power (i.e. replication), which can be arbitrarily high in a simulation context, producing minuscule p-values regardless of the effect size. Second, the null hypothesis of no difference between treatments (e.g. parameter values) is known a priori to be false, invalidating the premise of the test. Use of p-values is troublesome (rather than simply irrelevant) because small p-values lend a false sense of importance to observed differences. We argue that modelers should abandon this practice and focus on evaluating the magnitude of differences between simulations. A growing number of authors in the ecological literature use statistical methods common to experimental ecology to analyze the output of ecological simulation models. For example, authors may use analysis of variance (ANOVA) to test whether model runs with different parameter values or different functional forms produce statistically different outputs. We view significance testing applied to simulation model output as a misuse of statistical theory. In this article we explain our reasoning with the goals of discouraging the practice, encouraging instead a focus on the magnitude of differences between simulations (i.e. effect sizes), and sparking discussion regarding when ‐ if ever ‐ statistical significance tests could be appropriate. �怀e perils of placing too much emphasis on statistical

Beyond connectivity: how empirical methods can quantify population persistence to improve marine protected-area design.

Abstract: Demographic connectivity is a fundamental process influencing the dynamics and persistence of spatially structured populations. Consequently, quantifying connectivity is essential for properly designing networks of protected areas so that they achieve their core ecological objective of maintaining population persistence. Recently, many empirical studies in marine systems have provided essential, and historically challenging to obtain, data on patterns of larval dispersal and export from marine protected areas (MPAs). Here, we review the empirical studies that have directly quantified the origins and destinations of individual larvae and assess those studies' relevance to the theory of population persistence and MPA design objectives. We found that empirical studies often do not measure or present quantities that are relevant to assessing population persistence, even though most studies were motivated or contextualized by MPA applications. Persistence of spatial populations, like nonspatial populations, depends on replacement, whether individuals reproduce enough in their lifetime to replace themselves. In spatial populations, one needs to account for the effect of larval dispersal on future recruitment back to the local population through local retention and other connectivity pathways. The most commonly reported descriptor of larval dispersal was the fraction of recruitment from local origin (self-recruitment). Self-recruitment does not inform persistence-based MPA design because it is a fraction of those arriving, not a fraction of those leaving (local retention), so contains no information on replacement. Some studies presented connectivity matrices, which can inform assessments of persistence with additional knowledge of survival and fecundity after recruitment. Some studies collected data in addition to larval dispersal that could inform assessments of population persistence but which were not presented in that way. We describe how three pieces of empirical information are needed to fully describe population persistence in a network of MPAs: (1) lifetime fecundity, (2) the proportion of larvae that are locally retained (or the full connectivity matrix), and (3) survival rate after recruitment. We conclude by linking theory and data to provide detailed guidance to empiricists and practitioners on field sampling design and data presentation that better informs the MPA objective of population persistence.

The HMA-LMA Dichotomy Revisited: an Electron Microscopical Survey of 56 Sponge Species

Abstract: The dichotomy between high microbial abundance (HMA) and low microbial abundance (LMA) sponges has been long recognized. In the present study, 56 sponge species from three geographic regions (greater Caribbean, Mediterranean, Red Sea) were investigated by transmission electron microscopy for the presence of microorganisms in the mesohyl matrix. Additionally, bacterial enumeration by DAPI-counting was performed on a subset of samples. Of the 56 species investigated, 28 were identified as belonging to the HMA and 28 to the LMA category. The sponge orders Agelasida and Verongida consisted exclusively of HMA species, and the Poecilosclerida were composed only of LMA sponges. Other taxa contained both types of microbial associations (e.g., marine Haplosclerida, Homoscleromorpha, Dictyoceratida), and a clear phylogenetic pattern could not be identified. For a few sponge species, an intermediate microbial load was determined, and the microscopy data did not suffice to reliably determine HMA or LMA status. To experimentally determine the HMA or LMA status of a sponge species, we therefore recommend a combination of transmission electron microscopy and 16S rRNA gene sequence data. This study significantly expands previous reports on microbial abundances in sponge tissues and contributes to a better understanding of the HMA-LMA dichotomy in sponge-microbe symbioses.

Associations between parenting, media use, cumulative risk, and children's executive functioning.

Abstract: Objective This study was designed to examine how parenting style, media exposure, and cumulative risk were associated with executive functioning (EF) during early childhood. Methods A nationally representative group of US parents/caregivers (N = 1156) with 1 child between 2 and 8 years participated in a telephone survey. Parents were asked to report on their child's exposure to television, music, and book reading through a 24-hour time diary. Parents also reported a host of demographic and parenting variables as well as questions on their child's EF. Results Separate multiple regressions for preschool (2-5 years) and school-aged (6-8 years) children grouped by cumulative risk were conducted. Parenting style moderated the risks of exposure to background television on EF for high-risk preschool-age children. Educational TV exposure served as a buffer for high-risk school-aged children. Cumulative risk, age, and parenting quality interacted with a number of the exposure effects. Conclusions The study showed a complex pattern of associations between cumulative risk, parenting, and media exposure with EF during early childhood. Consistent with the American Academy of Pediatrics, these findings support the recommendation that background television should be turned off when a child is in the room and suggest that exposure to high-quality content across multiple media platforms may be beneficial.

The Brief Aggression Questionnaire: Psychometric and Behavioral Evidence for an Efficient Measure of Trait Aggression

Abstract: A key problem facing aggression research is how to measure individual differences in aggression accurately and efficiently without sacrificing reliability or validity. Researchers are increasingly demanding brief measures of aggression for use in applied settings, field studies, pretest screening, longitudinal, and daily diary studies. The authors selected the three highest loading items from each of the Aggression Questionnaire's (Buss & Perry, 1992) four subscales-Physical Aggression, Verbal Aggression, anger, and hostility-and developed an efficient 12-item measure of aggression-the Brief Aggression Questionnaire (BAQ). Across five studies (N = 3,996), the BAQ showed theoretically consistent patterns of convergent and discriminant validity with other self-report measures, consistent four-factor structures using factor analyses, adequate recovery of information using item response theory methods, stable test-retest reliability, and convergent validity with behavioral measures of aggression. The authors discuss the reliability, validity, and efficiency of the BAQ, along with its many potential applications. Aggr. Behav. 9999:XX-XX, 2013. © 2013 Wiley Periodicals, Inc. Language: en

Chemical defenses and resource trade-offs structure sponge communities on Caribbean coral reefs.

Abstract: Ecological studies have rarely been performed at the community level across a large biogeographic region. Sponges are now the primary habitat-forming organisms on Caribbean coral reefs. Recent species-level investigations have demonstrated that predatory fishes (angelfishes and some parrotfishes) differentially graze sponges that lack chemical defenses, while co-occurring, palatable species heal, grow, reproduce, or recruit at faster rates than defended species. Our prediction, based on resource allocation theory, was that predator removal would result in a greater proportion of palatable species in the sponge community on overfished reefs. We tested this prediction by performing surveys of sponge and fish community composition on reefs having different levels of fishing intensity across the Caribbean. A total of 109 sponge species was recorded from 69 sites, with the 10 most common species comprising 51.0% of sponge cover (3.6–7.7% per species). Nonmetric multidimensional scaling indicated that the species composition of sponge communities depended more on the abundance of sponge-eating fishes than geographic location. Across all sites, multiple-regression analyses revealed that spongivore abundance explained 32.8% of the variation in the proportion of palatable sponges, but when data were limited to geographically adjacent locations with strongly contrasting levels of fishing pressure (Cayman Islands and Jamaica; Curacao, Bonaire, and Martinique), the adjusted R2 values were much higher (76.5% and 94.6%, respectively). Overfishing of Caribbean coral reefs, particularly by fish trapping, removes sponge predators and is likely to result in greater competition for space between faster-growing palatable sponges and endangered reef-building corals.

Use of Synchronous Virtual Classrooms: Why, Who, and How?

Abstract: Virtual classrooms allow students and instructors to communicate synchronously using features such as audio, video, text chat, interactive whiteboard, and application sharing. The purpose of the study reported in this paper was to identify why instructors adopt synchronous virtual classrooms and how they use them after their adoption. An electronic survey was administered asking instructors from various institutions to describe their experience adopting a synchronous virtual classroom in either a blended or online course. In describing their reasons for adopting the technology, respondents most frequently cited institutional resource availability, increasing social presence, enhancing student learning, and the availability of technology. Along with audio chat, the features that most influenced the adoption of virtual classrooms and were used most frequently by respondents were the ability to archive conference sessions, see participants through webcams, and use text-based chat interfaces. Open-ended survey responses revealed that instructors used virtual classrooms to promote interactivity, develop community, and reach students at different locations. There were also distinct trends characterizing the demographics of faculty members who reported using virtual classrooms. These findings provide meaningful data for instructors interested in providing synchronous components in their online teaching and for administrators interested in promoting technology-enhanced learning on their campuses.

On the Economic Determinants of the Gold-Inflation Relation

Abstract: We examine the long term dynamic relation between inflation and the price of gold. We begin by showing that there is no cointegration between gold and the consumer price index (CPI) if the volatile period of the early 1980s is excluded from the data. However, we are also able to demonstrate that there is significant time variation in the relation, such that comovement between the variables has indeed increased in the last decade. Examination of the underlying macroeconomic factors that could generate time variation in the gold-CPI linkage suggests gold’s sensitivity to the CPI is related to interest rate changes: a finding that highlights the monetary nature of gold as a commodity.

Tailoring to Customers’ Needs: Understanding How to Promote an Adaptive Service Experience With Frontline Employees

Abstract: For most organizations, the ability to adapt a service experience is the responsibility of frontline employees (FLEs). Previous research on adapting or customizing a service has focused much of its attention on the internal motivations or predispositions of FLEs to adapt a service. However, the ability to adapt a service experience is often a function of management setting expectations and allocating appropriate resources. Regardless of the FLE’s internal motivation, service providers need to educate employees on how and when to adapt a customer’s service experience. Drawing on role theory, our study focuses on how mangers can promote adaptive behaviors with FLEs. Our findings identify two major processes in adapting a service experience: (1) recognition of customer needs through employee empathy and anticipation and (2) creation of alternatives to meet those needs through employee creativity. To further examine the managerial influence on adapting a service, we explore how the perceived service climate o...

Loss of optical and molecular indicators of terrigenous dissolved organic matter during long-term photobleaching

Abstract: Two water samples from the Great Dismal Swamp National Wildlife Refuge with high dissolved organic matter (DOM) concentrations (51 and 121 mg C L−1) were subjected to ultraviolet (UV) light for up to 110 days. During the course of the irradiations, 74–88 % of the original dissolved organic carbon was lost along with 95–99 % of the absorption at 300 nm. Based on changes observed during light exposure, three pools of DOM were identified: photo-labile, photo-refractory, and photo-produced compounds. Solid-state 13C nuclear magnetic resonance (NMR) spectroscopy and Fourier transform infrared (FTIR) spectroscopy were used to determine structural moieties characteristic to each of these pools. These analyses showed aromatic carbons were preferentially removed while carbohydrate-like and amide/peptide-like carbons were preserved during UV exposure. An increase in carbon normalized 13C NMR signal in the 0–50 ppm region suggests that alkyl moieties were produced, while FTIR signal at 1,745 cm−1 and two-dimensional 1H–13C NMR results confirmed the photochemical production of acetate. Several properties typically used to trace terrigenous DOM in ocean margin and marine environments were significantly altered. Optical properties, including absorption spectral slopes and fluorescence indices, as well as carbon-normalized lignin yields shifted from terrestrial values towards those more typical of coastal or open ocean samples. The loss of terrestrial signatures during irradiation highlights the difficulty faced when quantifying the contribution of terrigenous DOM to aquatic carbon pools.

Gelatinous zooplankton biomass in the global oceans: geographic variation and environmental drivers

Abstract: Aim: Scientific debate regarding the future trends, and subsequent ecological, biogeochemical and societal impacts, of gelatinous zooplankton (GZ) in a changing ocean is hampered by lack of a global baseline and an understanding of the causes of biogeographic patterns. We address this by using a new global database of GZ records to test hypotheses relating to environmental drivers of biogeographic variation in the multidecadal baseline of epipelagic GZ biomass in the world's oceans. Location: Global oceans. Methods: Over 476,000 global GZ data and metadata items were assembled from a variety of published and unpublished sources. From this, a total of 91,765 quantitative abundance data items from 1934 to 2011 were converted to carbon biomass using published biometric equations and species-specific average sizes. Total GZ, Cnidaria, Ctenophora and Chordata (Thaliacea) biomass was mapped into 5° grid cells and environmental drivers of geographic variation were tested using spatial linear models. Results: We present JeDI (the Jellyfish Database Initiative), a publically accessible database available at http://jedi.nceas.ucsb.edu. We show that: (1) GZ are present throughout the world's oceans; (2) the global geometric mean and standard deviation of total gelatinous biomass is 0.53 ± 16.16 mg C m−3, corresponding to a global biomass of 38.3 Tg C in the mixed layer of the ocean; (3) biomass of all gelatinous phyla is greatest in the subtropical and boreal Northern Hemisphere; and (4) within the North Atlantic, dissolved oxygen, apparent oxygen utilization and sea surface temperature are the principal drivers of biomass distribution. Main conclusions: JeDI is a unique global dataset of GZ taxa which will provide a benchmark against which future observations can be compared and shifting baselines assessed. The presence of GZ throughout the world's oceans and across the complete global spectrum of environmental variables indicates that evolution has delivered a range of species able to adapt to all available ecological niches.

Linking human well-being and jellyfish: ecosystem services, impacts and societal responses

Abstract: Jellyfish are usually perceived as harmful to humans and are seen as “pests”. This negative perception has hindered knowledge regarding their value in terms of ecosystem services. As humans increasingly modify and interact with coastal ecosystems, it is important to evaluate the benefits and costs of jellyfish, given that jellyfish bloom size, frequency, duration, and extent are apparently increasing in some regions of the world. Here we explore those benefits and costs as categorized by regulating, supporting, cultural, and provisioning ecosystem services. A geographical perspective of human vulnerability to jellyfish over four categories of human well-being (health care, food, energy, and freshwater production) is also discussed in the context of thresholds and trade-offs to enable social adaptation. Whereas beneficial services provided by jellyfish likely scale linearly with biomass (perhaps peaking at a saturation point), non-linear thresholds exist for negative impacts to ecosystem services. We suggest that costly adaptive strategies will outpace the beneficial services if jellyfish populations continue to increase in the future.

enaR: An r package for Ecosystem Network Analysis

Abstract: Summary Network analysis is a useful approach for investigating complex and relational data in many fields including ecology, molecular and evolutionary biology. Here, we introduce enaR , an r package for Ecosystem Network Analysis (ENA). ENA is an analytical tool set rooted in ecosystem ecology with over 30 years of development that examines the structure and dynamics of matter and energy movement between discrete ecological compartments (e.g. a food web). In addition to describing the primary functionality of the package, we highlight several features including a library of 100 empirical ecosystem models, the ability to analyse and compare multiple models simultaneously, and connections to other ecological network analysis tools in r.

The role of brand communications on front line service employee beliefs, behaviors, and performance

Abstract: Frontline service employees often vary in their delivery of the brand promise, leaving service firms with less direct control on other stakeholders’ brand perceptions. Internal branding efforts have been suggested as a way to improve employee performance. With this in mind, we develop a two-process model based on identification and internalization theories to explain how internally disseminating brand-relevant information to frontline employees enhances performance. Using multi-source data from the employees, managers, and customers of a business-to-business firm in the hospitality industry, we find that providing brand-specific information directly to frontline employees increases their identification with the brand (as evidenced in perceptions of firm authenticity) and enhances their internalization of brand values. Additional results suggest that firms should make an extra effort to communicate brand-specific information to frontline employees if they desire brand-consistent performance that is observable to managers and customers alike.

Phylogenetic relationships, morphological variation, and toxin patterns in the Alexandrium ostenfeldii (Dinophyceae) complex: implications for species boundaries and identities

Abstract: Alexandrium ostenfeldii (Paulsen) Balech and Tangen and A. peruvianum (Balech and B.R. Mendiola) Balech and Tangen are morphologically closely related dinoflagellates known to produce potent neurotoxins. Together with Gonyaulax dimorpha Biecheler, they constitute the A. ostenfeldii species complex. Due to the subtle differences in the morphological characters used to differentiate these species, unambiguous species identification has proven problematic. To better understand the species boundaries within the A. ostenfeldii complex we compared rDNA data, morphometric characters and toxin profiles of multiple cultured isolates from different geographic regions. Phylogenetic analysis of rDNA sequences from cultures characterized as A. ostenfeldii or A. peruvianum formed a monophyletic clade consisting of six distinct groups. Each group examined contained strains morphologically identified as either A. ostenfeldii or A. peruvianum. Though key morphological characters were generally found to be highly variable and not consistently distributed, selected plate features and toxin profiles differed significantly among phylogenetic clusters. Additional sequence analyses revealed a lack of compensatory base changes in ITS2 rRNA structure, low to intermediate ITS/5.8S uncorrected genetic distances, and evidence of reticulation. Together these data (criteria currently used for species delineation in dinoflagellates) imply that the A. ostenfeldii complex should be regarded a single genetically structured species until more material and alternative criteria for species delimitation are available. Consequently, we propose that A. peruvianum is a heterotypic synonym of A. ostenfeldii and this taxon name should be discontinued.

Understanding Human–Landscape Interactions in the “Anthropocene”

Abstract: This article summarizes the primary outcomes of an interdisciplinary workshop in 2010, sponsored by the U.S. National Science Foundation, focused on developing key questions and integrative themes for advancing the science of human–landscape systems. The workshop was a response to a grand challenge identified recently by the U.S. National Research Council (2010a)—“How will Earth’s surface evolve in the “Anthropocene?”—suggesting that new theories and methodological approaches are needed to tackle increasingly complex human–landscape interactions in the new era. A new science of human–landscape systems recognizes the interdependence of hydro-geomorphological, ecological, and human processes and functions. Advances within a range of disciplines spanning the physical, biological, and social sciences are therefore needed to contribute toward interdisciplinary research that lies at the heart of the science. Four integrative research themes were identified—thresholds/tipping points, time scales and time lags, spatial scales and boundaries, and feedback loops—serving as potential focal points around which theory can be built for human–landscape systems. Implementing the integrative themes requires that the research communities: (1) establish common metrics to describe and quantify human, biological, and geomorphological systems; (2) develop new ways to integrate diverse data and methods; and (3) focus on synthesis, generalization, and meta-analyses, as individual case studies continue to accumulate. Challenges to meeting these needs center on effective communication and collaboration across diverse disciplines spanning the natural and social scientific divide. Creating venues and mechanisms for sustained focused interdisciplinary collaborations, such as synthesis centers, becomes extraordinarily important for advancing the science.

Preliminary efficacy of prize-based contingency management to increase activity levels in healthy adults

Abstract: An estimated 30% of Americans meet the criteria for obesity. Effective, low-cost interventions to increase physical activity are needed to prevent and treat obesity. In this study, 11 healthy adults wore Fitbit accelerometers for 3 weeks. During the initial baseline, subjects earned prize draws for wearing the Fitbit. During intervention, percentile schedules were used to calculate individual prize-draw criteria. The final week was a return to baseline. Four subjects increased step counts as a result of the intervention. A bout analysis of interresponse times revealed that subjects increased overall step counts by increasing daily minutes active and within-bout response rates and decreasing pauses between bouts of activity. Strategies to improve effectiveness are suggested, such as modification of reinforcement probability and amount and identification of the function of periods of inactivity.

Low glucose relates to greater aggression in married couples

Abstract: Intimate partner violence affects millions of people globally. One possible contributing factor is poor self-control. Self-control requires energy, part of which is provided by glucose. For 21 days, glucose levels were measured in 107 married couples. To measure aggressive impulses, each evening participants stuck between 0 and 51 pins into a voodoo doll that represented their spouse, depending how angry they were with their spouse. To measure aggression, participants competed against their spouse on a 25-trial task in which the winner blasted the loser with loud noise through headphones. As expected, the lower the level of glucose in the blood, the greater number of pins participants stuck into the voodoo doll, and the higher intensity and longer duration of noise participants set for their spouse.

Short-term metabolic and growth responses of the cold-water coral Lophelia pertusa to ocean acidification

Abstract: Cold-water corals are associated with high local biodiversity, but despite their importance as ecosystem engineers, little is known about how these organisms will respond to projected ocean acidification. Since preindustrial times, average ocean pH has decreased from 8.2 to ~8.1, and predicted CO2 emissions will decrease by up to another 0.3 pH units by the end of the century. This decrease in pH may have a wide range of impacts upon marine life, and in particular upon calcifiers such as cold-water corals. Lophelia pertusa is the most widespread cold-water coral (CWC) species, frequently found in the North Atlantic. Here, we present the first short-term (21 days) data on the effects of increased CO2 (750 ppm) upon the metabolism of freshly collected L. pertusa from Mingulay Reef Complex, Scotland, for comparison with net calcification. Over 21 days, corals exposed to increased CO2 conditions had significantly lower respiration rates (11.4±1.39 SE, µmol O2 g−1 tissue dry weight h−1) than corals in control conditions (28.6±7.30 SE µmol O2 g−1 tissue dry weight h−1). There was no corresponding change in calcification rates between treatments, measured using the alkalinity anomaly technique and 14C uptake. The decrease in respiration rate and maintenance of calcification rate indicates an energetic imbalance, likely facilitated by utilisation of lipid reserves. These data from freshly collected L. pertusa from the Mingulay Reef Complex will help define the impact of ocean acidification upon the growth, physiology and structural integrity of this key reef framework forming species.

Down under the tunic: bacterial biodiversity hotspots and widespread ammonia-oxidizing archaea in coral reef ascidians

Abstract: Ascidians are ecologically important components of marine ecosystems yet the ascidian microbiota remains largely unexplored beyond a few model species We used 16S rRNA gene tag pyrosequencing to provide a comprehensive characterization of microbial symbionts in the tunic of 42 Great Barrier Reef ascidian samples representing 25 species Results revealed high bacterial biodiversity (3 217 unique operational taxonomic units (OTU003) from 19 described and 14 candidate phyla) and the widespread occurrence of ammonia-oxidizing Thaumarchaeota in coral reef ascidians (24 of 25 host species) The ascidian microbiota was clearly differentiated from seawater microbial communities and included symbiont lineages shared with other invertebrate hosts as well as unique, ascidian-specific phylotypes Several rare seawater microbes were markedly enriched (200–700 fold) in the ascidian tunic, suggesting that the rare biosphere of seawater may act as a conduit for horizontal symbiont transfer However, most OTUs (71%) were rare and specific to single hosts and a significant correlation between host relatedness and symbiont community similarity was detected, indicating a high degree of host-specificity and potential role of vertical transmission in structuring these communities We hypothesize that the complex ascidian microbiota revealed herein is maintained by the dynamic microenvironments within the ascidian tunic, offering optimal conditions for different metabolic pathways such as ample chemical substrate (ammonia-rich host waste) and physical habitat (high oxygen, low irradiance) for nitrification Thus, ascidian hosts provide unique and fertile niches for diverse microorganisms and may represent an important and previously unrecognized habitat for nitrite/nitrate regeneration in coral reef ecosystems

Depressive symptoms, self-esteem, HIV symptom management self-efficacy and self-compassion in people living with HIV

Abstract: The aims of this study were to examine differences in self-schemas between persons living with HIV/AIDS with and without depressive symptoms, and the degree to which these self-schemas predict depressive symptoms in this population. Self-schemas are beliefs about oneself and include self-esteem, HIV symptom management self-efficacy, and self-compassion. Beck's cognitive theory of depression guided the analysis of data from a sample of 1766 PLHIV from the USA and Puerto Rico. Sixty-five percent of the sample reported depressive symptoms. These symptoms were significantly (p ≤ 0.05), negatively correlated with age (r = -0.154), education (r = -0.106), work status (r = -0.132), income adequacy (r = -0.204, self-esteem (r = -0.617), HIV symptom self-efficacy (r = - 0.408), and self-kindness (r = - 0.284); they were significantly, positively correlated with gender (female/transgender) (r = 0.061), white or Hispanic race/ethnicity (r = 0.047) and self-judgment (r = 0.600). Fifty-one percent of the variance (F = 177.530 (df = 1524); p < 0.001) in depressive symptoms was predicted by the combination of age, education, work status, income adequacy, self-esteem, HIV symptom self-efficacy, and self-judgment. The strongest predictor of depressive symptoms was self-judgment. Results lend support to Beck's theory that those with negative self-schemas are more vulnerable to depression and suggest that clinicians should evaluate PLHIV for negative self-schemas. Tailored interventions for the treatment of depressive symptoms in PLHIV should be tested and future studies should evaluate whether alterations in negative self-schemas are the mechanism of action of these interventions and establish causality in the treatment of depressive symptoms in PLHIV.

Biogeography rather than association with cyanobacteria structures symbiotic microbial communities in the marine sponge Petrosia ficiformis

Abstract: The sponge Petrosia ficiformis is ubiquitous in the Mediterranean Sea and Eastern Atlantic Ocean, hosting a diverse assemblage of bacteria, including, in illuminated sites, cyanobacteria. Two closely related sponge color morphs have been described, one inside caves and at their entrance (white/pink), and one on the rocky cliffs (violet). The presence of the different morphs and their ubiquity in the Mediterranean (from North-West to South-East) provides an opportunity to examine which factors mostly affect the associated microbial communities in this species: (i) presence of phototrophic symbionts or (ii) biogeography. 16S rRNA gene tag pyrosequencing data of the microbial communities revealed that Chloroflexi, Gammaproteobacteria, and Acidobacteria dominated the bacterial communities of all sponges analyzed. Chlorophyll a content, TEM observations and DNA sequence data confirmed the presence of the cyanobacterium Synechococcus feldmannii in violet and pink morphs of P. ficiformis and their absence in white color morphs. Rather than cyanobacterial symbionts (i.e., color morphs) accounting for variability in microbial symbiont communities, a biogeographic trend was observed between P. ficiformis collected in Israel and Italy. Analyses of partial 18S rRNA and mitochondrial cytochrome c oxidase subunit I (COX1) gene sequences revealed consistent genetic divergence between the violet and pink-white morphotypes of P. ficiformis. Overall, data indicated that microbial symbiont communities were more similar in genetically distinct P. ficiformis from the same location, than genetically similar P. ficiformis from distant locations.