Conservation Genetics at the Interface of Theory and Application

Understanding the ecological mechanisms responsible for patterns of spatial genetic structure and diversity is a central issue to evolutionary ecology and biodiversity conservation. The Anthropocene has seen a mass extinction only previously observed through geological records, and freshwater fishes of North America have not been spared owing to large-scale modification of freshwater habitats and introduction of nonnative species. Concomitant with reduced numbers of species is a rapid reduction in genetic diversity within species; this diversity that is required for species to adapt to rapidly changing environments of human dominated landscapes. However, understanding why species exhibit different patterns of spatial genetic structure and genetic diversity requires substantial ecological data and knowledge of species life histories. This body of research incorporates both ecological and genetic data to address key issues related to the conservation of native fishes of the upper Gila River, NM, USA, and evaluates how differences in ecology among species influences their evolutionary trajectories (i.e., genetic diversity and structuring). Chapter 1 adopted a conservation genetics approach to evaluate the genetic health and long-term maintenance of genetic diversity of three imperiled species protected by New Mexico State and United States Federal laws. Estimates of contemporary effective size were low for these species, as were estimates of genetic structure (all species FST \u3c 0.025) suggesting moderate to high gene flow for all species. Chapter 2 broadened the scope of focal species by including most of the fish community and increasing life history variation to evaluate how dispersal and life history influence patterns of genetic structure within a shared riverscape (i.e., attributes of a landscape specifically related to networks of streams and rivers). A key result was that genetic patterns were highly variable among species and related to life history and abundance. Across species, overall genetic differentiation (FST) was not strongly predicted by species traits, but fecundity was negatively associated with effect of distance on genetic structure (measured by Mantel\u27s r). Chapter 3 examined the relationship between metapopulation processes and species evolutionary trajectories. Metapopulation genetic effective size was reduced by temporal instability (extirpation/recolonization), but high abundance appeared to counter balance effects of temporal instability. These results indicate that ecological trade-offs related to life-history strategies (e.g., fecundity, body size, parental investment, etc.) also influence individual species\u27 evolutionary responses (i.e., genetic diversity and differentiation) to landscape factors and threats to persistence

Consecutive wildfires affect stream biota in cold- and warmwater dryland river networks

Citation: Whitney, J. E., Gido, K. B., Pilger, T. J., Propst, D. L., & Turner, T. F. (2015). Consecutive wildfires affect stream biota in cold- and warmwater dryland river networks. Freshwater Science, 34(4), 1510-1526. doi:10.1086/683391Climate change and fire suppression have altered fire regimes globally, leading to larger, more frequent, and more severe wildfires. Responses of coldwater stream biota to single wildfires are well studied, but measured responses to consecutive wildfires in warmwater systems that often include mixed assemblages of native and nonnative taxa are lacking. We quantified changes in physical habitat, resource availability, and biomass of cold- and warmwater oligochaetes, insects, crayfish, fishes, and tadpoles following consecutive megafires (covering >100 km(2)) in the upper Gila River, New Mexico, USA. We were particularly interested in comparing responses of native and nonnative fishes that might have evolved under different disturbance regimes. Changes in habitat and resource availability were related to cumulative fire effects, fire size, and postfire precipitation. The 2nd of 2 consecutive wildfires in the basin was larger and, coupled with moderate postfire discharge, resulted in increased siltation and decreased algal biomass. Several insect taxa responded to these fires with reduced biomass, whereas oligochaete biomass was unaffected. Biomass of 6 of 7 native fish species decreased after the fires, and decreases were associated with site proximity to fire. Nonnative fish decreases after fire were most pronounced for coldwater salmonids, and warmwater nonnative fishes exhibited limited responses. All crayfish and tadpoles collected were nonnative and were unresponsive to fire disturbance. More pronounced responses of native insects and fishes to fires indicate that increasing fire size and frequency threatens the persistence of native fauna and suggests that management activities promoting ecosystem resilience might help ameliorate wildfire effects

Influence of Selective Laser Trabeculoplasty (SLT) on the iStent inject® outcomes

Background: To evaluate the influence of Selective Laser Trabeculoplasty (SLT) on iStent inject® outcomes in open-angle glaucoma (OAG). Methods: In this retrospective comparative cohort outcome study, 66 patients who were treated with two iStent inject® devices were included. Patients were divided into two subgroups consisting of patients without SLT treatment prior to surgery and patients who had been treated previously with 360° SLT but without sufficient response. Outcome measures included intraocular pressure (IOP) and number of antiglaucoma medications after 6 weeks with three, six, 12, and 24 month follow-ups. Results: Mean preoperative IOP decreased from 20.4 ± 5.3 mmHg to 14.8 ± 3.0 mmHg for patients without SLT treatment prior to surgery (p = 0.001) and from 19.2 ± 4.5 mmHg to 14.0 ± 1.6 mmHg for patients with insufficient response to 360° SLT treatment (p = 0.027) at 12 months after iStent inject® implantation. No significant difference was found between the two groups (p > 0.05). The number of antiglaucoma medications did not change in both groups (p > 0.05) and showed no significant difference between the two groups (p > 0.05). Conclusion: Prior SLT treatment seems to have no negative influence on the IOP lowering-effect of iStent inject® implantation in patients with OAG. It is therefore an appropriate incremental procedure with no exclusion criterion for an iStent inject® implantation

A multi-technology analysis of the 2017 North Korean nuclear test

On 3 September 2017 official channels of the Democratic People's Republic of Korea announced the successful test of a thermonuclear device. Only seconds to minutes after the alleged nuclear explosion at the Punggye-ri nuclear test site in the mountainous region in the country's northeast at 03:30:02 (UTC), hundreds of seismic stations distributed all around the globe picked up strong and distinct signals associated with an explosion. Different seismological agencies reported body wave magnitudes of well above 6.0, consequently estimating the explosive yield of the device on the order of hundreds of kT TNT equivalent. The 2017 event can therefore be assessed as being multiple times larger in energy than the two preceding North Korean events in January and September 2016. This study provides a multi-technology analysis of the 2017 North Korean event and its aftermath using a wide array of geophysical methods. Seismological investigations locate the event within the test site at a depth of approximately 0.6&thinsp;km below the surface. The radiation and generation of P- and S-wave energy in the source region are significantly influenced by the topography of the Mt. Mantap massif. Inversions for the full moment tensor of the main event reveal a dominant isotropic component accompanied by significant amounts of double couple and compensated linear vector dipole terms, confirming the explosive character of the event. The analysis of the source mechanism of an aftershock that occurred around 8&thinsp;min after the test in the direct vicinity suggest a cavity collapse. Measurements at seismic stations of the International Monitoring System result in a body wave magnitude of 6.2, which translates to an yield estimate of around 400&thinsp;kT TNT equivalent. The explosive yield is possibly overestimated, since topography and depth phases both tend to enhance the peak amplitudes of teleseismic P waves. Interferometric synthetic aperture radar analysis using data from the ALOS-2 satellite reveal strong surface deformations in the epicenter region. Additional multispectral optical data from the Pleiades satellite show clear landslide activity at the test site. The strong surface deformations generated large acoustic pressure peaks, which were observed as infrasound signals with distinctive waveforms even at distances of 401&thinsp;km. In the aftermath of the 2017 event, atmospheric traces of the fission product 133Xe were detected at various locations in the wider region. While for 133Xe measurements in September 2017, the Punggye-ri test site is disfavored as a source by means of atmospheric transport modeling, detections in October 2017 at the International Monitoring System station RN58 in Russia indicate a potential delayed leakage of 133Xe at the test site from the 2017 North Korean nuclear test.</p

Using dense seismo-acoustic network to provide timely warning of the 2019 paroxysmal Stromboli eruptions

Stromboli Volcano is well known for its persistent explosive activity. On July 3rd and August 28th 2019, two paroxysmal explosions occurred, generating an eruptive column that quickly rose up to 5 km above sea level. Both events were detected by advanced local monitoring networks operated by Istituto Nazionale di Geofisica e Vulcanologia (INGV) and Laboratorio di Geofisica Sperimentale of the University of Firenze (LGS-UNIFI). Signals were also recorded by the Italian national seismic network at a range of hundreds of kilometres and by infrasonic arrays up to distances of 3700 km. Using state-of-the-art propagation modeling, we identify the various seismic and infrasound phases that are used for precise timing of the eruptions. We highlight the advantage of dense regional seismo-acoustic networks to enhance volcanic signal detection in poorly monitored regions, to provide timely warning of eruptions and reliable source amplitude estimate to Volcanic Ash Advisory Centres (VAAC)

Controlling Tungiasis in an Impoverished Community: An Intervention Study

Tungiasis is a disease caused by the sand flea Tunga penetrans, a parasite prevalent in many impoverished communities in developing countries. The female sand flea penetrates into the skin of animals and humans where it grows rapidly in size, feeds on the host's blood, produces eggs which are expelled into the environment, and eventually dies in situ. The lesions become frequently superinfected and the infestation is associated with considerable morbidity. Clearly, tungiasis is a neglected disease of neglected populations. We investigated the impact of a package of intervention measures targeted against on-host and off-host stages of T. penetrans in a fishing community in Northeast Brazil. These measures decreased disease occurrence only temporarily, but had a sustained effect on the intensity of the infestation. Since infestation intensity and morbidity are correlated, presumably the intervention also lowered tungiasis-associated morbidity. Control measures similar to the ones used in this study may help to effectively control tungiasis in impoverished communities

Non-cytotoxic 1,2,3-triazole tethered fused heterocyclic ring derivatives display Tax protein inhibition and impair HTLV-1 infected cells

Human T cell lymphotropic virus type 1 (HTLV-1) is a human retrovirus that infects approximately 10–20 million people worldwide and causes an aggressive neoplasia (adult T-cell leukemia/lymphoma - ATL). Therapeutic approaches for the treatment of ATL have variable effectiveness and poor prognosis, thus requiring strategies to identify novel compounds with activity on infected cells. In this sense, we initially screened a small series of 25 1,2,3-triazole derivatives to discover cell proliferation inhibitors and apoptosis inducers in HTLV-1-infected T-cell line (MT-2) for further assessment of their effect on viral tax activity through inducible-tax reporter cell line (Jurkat LTR-GFP). Eight promising compounds (02, 05, 06, 13, 15, 21, 22 and 25) with activity ≥70% were initially selected, based on a suitable cell-based assay using resazurin reduction method, and evaluated towards cell cycle, apoptosis and Tax/GFP expression analyses through flow cytometry. Compound 02 induced S phase cell cycle arrest and compounds 05, 06, 22 and 25 promoted apoptosis. Remarkably, compounds 22 and 25 also reduced GFP expression in an inducible-tax reporter cell, which suggests an effect on Tax viral protein. More importantly, compounds 02, 22 and 25 were not cytotoxic in human hepatoma cell line (Huh-7). Therefore, the discovery of 3 active and non-cytotoxic compounds against HTLV-1-infected cells can potentially contribute, as an initial promising strategy, to the development process of new drugs against ATL

Crustal structure of the Peruvian continental margin from wide-angle seismic studies

Active seismic investigations along the Pacific margin off Peru were carried out using ocean bottom hydrophones and seismometers. The structure and the P-wave velocities of the obliquely subducting oceanic Nazca Plate and overriding South American Plate from 8°S to 15°S were determined by modelling the wide-angle seismic data combined with the analysis of reflection seismic data. Three detailed cross-sections of the subduction zone of the Peruvian margin and one strike-line across the Lima Basin are presented here. The oceanic crust of the Nazca Plate, with a thin pelagic sediment cover, ranging from 0–200 m, has an average thickness of 6.4 km. At 8°S it thins to 4 km in the area of Trujillo Trough, a graben-like structure. Across the margin, the plate boundary can be traced to 25 km depth. As inferred from the velocity models, a frontal prism exists adjacent to the trench axis and is associated with the steep lower slope. Terrigeneous sediments are proposed to be transported downslope due to gravitational forces and comprise the frontal prism, characterized by low seismic P-wave velocities. The lower slope material accretes against a backstop structure, which is defined by higher seismic P-wave velocities, 3.5–6.0 km s−1. The large variations in surface slope along one transect may reflect basal removal of upper plate material, thus steepening the slope surface. Subduction processes along the Peruvian margin are dominated by tectonic erosion indicated by the large margin taper, the shape and bending of the subducting slab, laterally varying slope angles and the material properties of the overriding continental plate. The erosional mechanisms, frontal and basal erosion, result in the steepening of the slope and consequent slope failure

Change but no climate change: discourses of climate change in corporate social responsibility reporting in the oil industry

Using corpus linguistic tools and methods, this paper investigates the discourses of climate change in corporate social responsibility (CSR) and environmental reports produced by major oil companies from 2000 to 2013. It focuses on the frequency of key references to climatic changes and examines in detail discourses surrounding the most frequently used term ‘climate change’. The analysis points to shifting patterns in the ways in which climate change has been discursively constructed in the studied sample. Whereas in the mid-2000s, it was seen as a phenomenon that something could be done about, in recent years the corporate discourse has increasingly emphasised the notion of risk portraying climate change as an unpredictable agent. A pro-active stance signalled by the use of force metaphors is offset by a distancing strategy often indicated through the use of hedging devices and ‘relocation’ of climate change to the future and other stakeholders. In doing so, the discourse obscures the sector’s large contribution to environmental degradation and ‘grooms’ the public perception to believe that the industry actively engages in climate change mitigation. At the methodological level, this study shows how a combination of quantitative corpus-linguistic and qualitative discourse-analytical techniques can offer insights into the existence of salient discursive patterns and contribute to a better understanding of the role of language in performing ideological work in corporate communications