Size and Density of Upside-Down Jellyfish, \u3ci\u3eCassiopea\u3c/i\u3e sp., and Their Impact on Benthic Fluxes in a Caribbean Lagoon

Anthropogenic disturbances may be increasing jellyfish populations globally. Epibenthic jellyfish are ideal organisms for studying this phenomenon due to their sessile lifestyle, broad geographic distribution, and prevalence in near-shore coastal environments. There are few studies, however, that have documented epibenthic jellyfish abundance and measured their impact on ecological processes in tropical ecosystems. In this study, the density and size of the upside-down jellyfish (Cassiopea spp.) were measured in Codrington Lagoon, Barbuda. A sediment core incubation study, with and without Cassiopea, also was performed to determine their impact on benthic oxygen and nutrient fluxes. Densities of Cassiopea were 24–168 m−2, among the highest reported values in the literature. Under illuminated conditions, Cassiopea increased oxygen production \u3e300% compared to sediment alone, and they changed sediments from net heterotrophy to net autotrophy. Cassiopea increased benthic ammonium uptake, but reduced nitrate uptake, suggesting they can significantly alter nitrogen cycling. Future studies should quantify the abundance of Cassiopea and measure their impacts on ecosystem processes, in order to further determine how anthropogenic-related changes may be altering the function of tropical coastal ecosystems

A queer politics of emotion: reimagining sexualities and schooling

peer-reviewedThis paper draws together Hochschild’s (1979; 1983) concepts of emotional labour and feeling rules with Ahmed’s affective economies (2004a, 2004b; 2008; 2010) and queer phenomenology (2006a, 2006b) as a way to address wider questions about sexuality and schooling. It highlights the value of the everyday politics of emotion for elucidating and clarifying the specificities, pertinence and complementarities of Hochschild’s and Ahmed’s work for reimagining the relationship between sexualities and schooling. The combination of their approaches allows for a focus on the individual, bodily management of emotions while demonstrating the connectedness of bodies and spaces. It enables disruption of ‘inclusive’ and ‘progressive’ educational approaches that leave heterosexuality uninterrupted and provides insight into how power works in and across the bodies, discourses, practices, relations and spaces of schools to maintain a collective orientation towards heterosexuality. It also counters linear narratives of progressive change, elucidating how change is a hopeful but messy process of simultaneous constraint, transgression and transformation. Key moments from a three-year study with LGBT-Q teachers entering into civil partnerships (CP) in Ireland serve as exploratory examples of the theoretical ideas put forward in this paper.ACCEPTEDpeer-reviewe

GABAergic Gene Expression in Postmortem Hippocampus from Alcoholics and Cocaine Addicts; Corresponding Findings in Alcohol-Naïve P and NP Rats

BACKGROUND:By performing identical studies in humans and rats, we attempted to distinguish vulnerability factors for addiction from neurobiological effects of chronic drug exposure. We focused on the GABAergic system within the hippocampus, a brain region that is a constituent of the memory/conditioning neuronal circuitry of addiction that is considered to be important in drug reinforcement behaviors in animals and craving and relapse in humans. METHODOLOGY:Using RNA-Seq we quantified mRNA transcripts in postmortem total hippocampus from alcoholics, cocaine addicts and controls and also from alcohol-naïve, alcohol preferring (P) and non-preferring (NP) rats selectively bred for extremes of alcohol-seeking behavior that also show a general addictive tendency. A pathway-targeted analysis of 25 GABAergic genes encoding proteins implicated in GABA synthesis, metabolism, synaptic transmission and re-uptake was undertaken. PRINCIPAL FINDINGS:Directionally consistent and biologically plausible overlapping and specific changes were detected: 14/25 of the human genes and 12/25 of the rat genes showed nominally significant differences in gene expression (global p values: 9×10⁻¹⁴, 7×10⁻¹¹ respectively). Principal FDR-corrected findings were that GABBR1 was down-regulated in alcoholics, cocaine addicts and P rats with congruent findings in NSF, implicated in GABAB signaling efficacy, potentially resulting in increased synaptic GABA. GABRG2, encoding the gamma2 subunit required for postsynaptic clustering of GABAA receptors together with GPHN, encoding the associated scaffolding protein gephryin, were both down-regulated in alcoholics and cocaine addicts but were both up-regulated in P rats. There were also expression changes specific to cocaine addicts (GAD1, GAD2), alcoholics (GABRA2) and P rats (ABAT, GABRG3). CONCLUSIONS/SIGNIFICANCE:Our study confirms the involvement of the GABAergic system in alcoholism but also reveals a hippocampal GABA input in cocaine addiction. Congruent findings in human addicts and P rats provide clues to predisposing factors for alcohol and drug addiction. Finally, the results of this study have therapeutic implications

Denitrification measurements in various plant communities

<p>Data table of denitrification measurements included in the meta-analysis, "Effects of wetland plants on denitrification rates." All denitrification measurements were converted to the same units (g N m-2 h-1). Measurements are categorized by the dominant species in the plant community; the genus, family, and growth form of the dominant species and whether it is a monocot or dicot; the type of wetland system in which the study was conducted; and the method used to measure denitrification rates. The effect size of vegetation on denitrification rates and variance in effect size are reported in columns “lnR” and “Var(lnR),” respectively.</p

Invasive-Plant Management and Nitrogen Removal

<p>Results from analyses of these data are reported in "Effects of invasive-plant management on nitrogen-removal ecosystem services in freshwater tidal marshes" (in review).</p

Discriminant analysis of plant communities.

<p>Three a priori vegetation-cover types [<i>Phragmites</i>, <i>Typha</i>, Removal] were distinguished based on a weighted linear combination of component species’ biomass. (Wilks’ Λ = 0.017, Approx. F_18,26 = 9.603, p <0.001, percent misclassified = 4.167).</p

Denitrification potentials of sediments before and after <i>Phragmites</i> removal in different vegetation types.

<p>Denitrification potentials at all sites showed substantial interannual and interseasonal variability. Relative to <i>Phragmites</i>-dominated sites (purple), denitrification potentials in removal sites (brown) decreased by 50% following initial herbicide treatment (vertical black line). This effect persisted for two years following removal. Error bars show standard errors.</p

Photos from Ramshorn Marsh.

<p>Photos were taken (A) prior to removal in August 2010, (B) one year following removal in September 2011, and (C) two years following removal in September 2012.</p