Promoting Amphibian Conservation through the College Classroom: Detection of Batrachochytrium dendrobatidis among Local Amphibians

Many global amphibian declines have been linked to the fungal pathogen Batrachochytrium dendrobatidis (Bd). The knowledge on Bd distribution provides a fundamental basis for amphibian conservation planning. Yet, such Bd distribution information is currently insufficient, in particular at a regional scale. The college classroom provides an excellent opportunity to expand the knowledge of Bd distribution. Here we provide an example of such research projects to detect Bd prevalence among local amphibians in a college course setting and present the results of work conducted in central Pennsylvania, USA. We collected toe clips and conducted PCR assays of six species, Plethodon cinereus, Desmognathus fuscus, Notophthalmus viridescens, Lithobates catesbeianus, L. clamitans, and L. sylvaticus (59 individuals). Four groups of students independently conducted entire projects, orally presented their findings, and submitted manuscripts to the professor at the end of the semester. This example demonstrates that it is feasible for an undergraduate class to complete a Bd-detection project within a single semester. Such a project not only contributes to Bd research but also promotes conservation education among students through hands-on research experiences. We found Bd infection in only one sample of N. viridescens, but no sign of infection in the rest of the samples. As a relatively high prevalence of Bd has been reported in surrounding areas, our results suggest spatial heterogeneity in Bd occurrence at a regional scale and thus, the need for continued efforts to monitor Bd prevalence.

Serotonin transporter genotype differentially modulates neural responses to emotional words following tryptophan depletion in patients recovered from depression and healthy volunteers

Previous studies have suggested that polymorphism in the serotonin transporter gene (5-HTTLPR) influences responses to serotonergic manipulation, with opposite effects in patients recovered from depression (rMDD) and controls. Here we sought to clarify the neurocognitive mechanisms underpinning these surprising results. Twenty controls and 23 rMDD subjects completed the study; functional magnetic resonance imaging (fMRI) and genotype data were available for 17 rMDD subjects and 16 controls. Following tryptophan or sham depletion, subjects performed an emotional-processing task during fMRI. Although no genotype effects on mood were identified, significant genotype(∗)diagnosis(∗)depletion interactions were observed in the hippocampus and subgenual cingulate in response to emotionally valenced words. In both regions, tryptophan depletion increased responses to negative words, relative to positive words, in high-expression controls, previously identified as being at low-risk for mood change following this procedure. By contrast, in higher-risk low-expression controls and high-expression rMDD subjects, tryptophan depletion had the opposite effect. Increased neural responses to negative words following tryptophan depletion may reflect an adaptive mechanism promoting resilience to mood change following perturbation of the serotonin system, which is reversed in sub-groups vulnerable to developing depressive symptoms. However, this interpretation is complicated by our failure to replicate previous findings of increased negative mood following tryptophan depletion.

Mutations in CTC1, encoding conserved telomere maintenance component 1, cause Coats plus

Coats plus is a highly pleiotropic disorder particularly affecting the eye, brain, bone and gastrointestinal tract. Here, we show that Coats plus results from mutations in CTC1, encoding conserved telomere maintenance component 1, a member of the mammalian homolog of the yeast heterotrimeric CST telomeric capping complex. Consistent with the observation of shortened telomeres in an Arabidopsis CTC1 mutant and the phenotypic overlap of Coats plus with the telomeric maintenance disorders comprising dyskeratosis congenita, we observed shortened telomeres in three individuals with Coats plus and an increase in spontaneous γH2AX-positive cells in cell lines derived from two affected individuals. CTC1 is also a subunit of the α-accessory factor (AAF) complex, stimulating the activity of DNA polymerase-α primase, the only enzyme known to initiate DNA replication in eukaryotic cells. Thus, CTC1 may have a function in DNA metabolism that is necessary for but not specific to telomeric integrity.

Zoë Wicomb's Ghosts. Uncanny Translocations in David's Story and The One That Got Away

This essay analyses Zoë Wicomb's novel David's Story and her latest collection of short stories, The One That Got Away, through the lense of cosmopolitanism and Jacques Derrida's concept of ‘hauntology’. Wicomb is a cosmopolitan author in a very precise sense: an author who embeds locally specific stories in a complex intertextual, historical and transnational web of cross-references. As settings, characters and objects move between Scotland and South Africa, it appears that the histories of these countries are mutually haunted by each other. Uncanny encounters with the past, and with memorials and art objects that take on a spectral quality, evoke an increasing sense of disorientation on the part of protagonists and readers alike. Assumptions about place, history and identity are thus constantly undermined and reconfigured.