Utilizing conservation genetics as a strategy for recovering the endangered Candy Darter (Etheostoma osburni) in West Virginia

The Candy Darter (Etheostoma osburni) is a small freshwater fish native to the New River drainage in West Virginia and Virginia that was listed as endangered in November 2018. It has been extirpated from much of its historic range in West Virginia, restricting it to the Gauley and Greenbrier river drainages. In addition to extirpations, the species is threatened by introgressive hybridization with the invasive Variegate Darter (E. variatum). Previous research primarily focused on hybridization, but population genetic analyses were limited. Population genetic analyses aim to identify distinct populations through genetic structure and characterize the levels of genetic diversity amongst those populations. A series of reintroductions of wild-caught individuals from the Greenbrier River drainage was performed to create new populations that were not under threat of hybridization. Fish were stocked into Camp Creek and the Little Bluestone River in the Bluestone River drainage of southern West Virginia. Individuals from throughout the Greenbrier and Gauley River drainages along with the newly introduced individuals were genotyped with 12 microsatellite loci to assess their population structure and diversity. These results were used to make recommendations about conservation units and future reintroduction efforts. A watershed-level landscape assessment was performed on the Camp Creek and Little Bluestone River watersheds to compare the source habitat to the new habitat. There is strong evidence that the Greenbrier drainage population and the Gauley River drainage population are highly distinct and represent separate ESUs that should be treated as separate Recovery Units (RUs). The reintroduced population’s genetic diversity captures the diversity of the source (Greenbrier drainage), but the landscapes of the new watersheds present some challenges to managers with higher levels of agriculture, resource extraction, and private land. The long-term persistence of E. osburni populations relies on continued monitoring and management of their genetics

Effects of experimental warming and carbon addition on nitrate reduction and respiration in coastal sediments

Author Posting. © The Author(s), 2015. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Biogeochemistry 125 (2015): 81-95, doi:10.1007/s10533-015-0113-4.Climate change may have differing effects on microbial processes that control coastal N availability. We conducted a microcosm experiment to explore effects of warming and carbon availability on nitrate reduction pathways in marine sediments. Sieved continental shelf sediments were incubated for 12 weeks under aerated seawater amended with nitrate (~50 μM), at winter (4°C) or summer (17°C) temperatures, with or without biweekly particulate organic C additions. Treatments increased diffusive oxygen consumption as expected, with somewhat higher effects of C addition compared to warming. Combined warming and C addition had the strongest effect on nitrate flux across the sediment water interface, with a complete switch early in the experiment from influx to sustained efflux. Supporting this result, vial incubations with added 15N-nitrate indicated that C addition stimulated potential rates of dissimilatory nitrate reduction to ammonium (DNRA), but not denitrification. Overall capacity for both denitrification and DNRA was reduced in warmed treatments, possibly reflecting C losses due to increased respiration with warming. Anammox potential rates were much lower than DNRA or denitrification, and were slightly negatively affected by warming or C addition. Overall, results indicate that warming and C addition increased ammonium production through remineralization and possibly DNRA. This stimulated nitrate production through nitrification, but without a comparable increase in nitrate consumption through denitrification. The response to C of potential DNRA rates over denitrification, along with a switch to nitrate efflux, raises the possibility that DNRA is an important and previously overlooked source of internal N cycling in shelf sediments.This material is based upon work supported by the National Science Foundation by OCE- 0852289 to JJR and OCE-0852263 and OCE-0927400 to AEG, and Rhode Island Sea Grant to JJR

Similar temperature responses suggest future climate warming will not alter partitioning between denitrification and anammox in temperate marine sediments

Author Posting. © The Author(s), 2016. This is the author's version of the work. It is posted here by permission of John Wiley & Sons for personal use, not for redistribution. The definitive version was published in Global Change Biology 23 (2017): 331-340, doi:10.1111/gcb.13370.Removal of biologically available nitrogen (N) by the microbially mediated processes denitrification and anaerobic ammonium oxidation (anammox) affects ecosystem N availability. Although few studies have examined temperature responses of denitrification and anammox, previous work suggests that denitrification could become more important than anammox in response to climate warming. To test this hypothesis, we determined whether temperature responses of denitrification and anammox differed in shelf and estuarine sediments from coastal Rhode Island over a seasonal cycle. The influence of temperature and organic C availability was further assessed in a 12-week laboratory microcosm experiment. Temperature responses, as characterized by thermal optima (Topt) and apparent activation energy (Ea), were determined by measuring potential rates of denitrification and anammox at 31 discrete temperatures ranging from 3 to 59°C. With a few exceptions, Topt and Ea of denitrification and anammox did not differ in Rhode Island sediments over the seasonal cycle. In microcosm sediments, Ea was somewhat lower for anammox compared to denitrification across all treatments. However, Topt did not differ between processes, and neither Ea nor Topt changed with warming or carbon addition. Thus, the two processes behaved similarly in terms of temperature response, and this response was not influenced by warming. This led us to reject the hypothesis that anammox is more cold-adapted than denitrification in our study system. Overall, our study suggests that temperature responses of both processes can be accurately modeled for temperate regions in the future using a single set of parameters, which are likely not to change over the next century as a result of predicted climate warming. We further conclude that climate warming will not directly alter the partitioning of N flow through anammox and denitrification.This material is based upon work supported by the National Science Foundation under Grant No. OCE-0852289 to JJR and OCE-0852263, OCE-0927400 and OCE1238212 to AEG, and Rhode Island Sea Grant to JJR.2017-05-2

The chameleon groups of Richard J. Thompson: automorphisms and dynamics

The automorphism groups of several of Thompson's countable groups of piecewise linear homeomorphisms of the line and circle are computed and it is shown that the outer automorphism groups of these groups are relatively small. These results can be interpreted as stability results for certain structures of PL functions on the circle. Machinery is developed to relate the structures on the circle to corresponding structures on the line

Commensurations and Subgroups of Finite Index of Thompson's Group F

We determine the abstract commensurator com(F) of Thompson's group F and describe it in terms of piecewise linear homeomorphisms of the real line and in terms of tree pair diagrams. We show com (F) is not finitely generated and determine which subgroups of finite index in F are isomorphic to F. We show that the natural map from the commensurator group to the quasi-isometry group of F is injective.Comment: 9 page

Fractal Weyl law for quantum fractal eigenstates

The properties of the resonant Gamow states are studied numerically in the semiclassical limit for the quantum Chirikov standard map with absorption. It is shown that the number of such states is described by the fractal Weyl law and their Husimi distributions closely follow the strange repeller set formed by classical orbits nonescaping in future times. For large matrices the distribution of escape rates converges to a fixed shape profile characterized by a spectral gap related to the classical escape rate.Comment: 4 pages, 5 figs, minor modifications, research at http://www.quantware.ups-tlse.fr

The lived experience of recovery in borderline personality disorder: a qualitative study

BackgroundThe concept of recovery in borderline personality disorder (BPD) is not well defined. Whilst clinical approaches emphasise symptom reduction and functioning, consumers advocate for a holistic approach. The consumer perspective on recovery and comparisons of individuals at varying stages have been minimally explored.MethodFourteen narratives of a community sample of adult women with a self-reported diagnosis of BPD, were analysed using qualitative interpretative phenomenological analysis to understand recovery experiences. Individuals were at opposite ends of the recovery continuum (seven recovered and seven not recovered).ResultsRecovery in BPD occurred across three stages and involved four processes. Stages included; 1) being stuck, 2) diagnosis, and 3) improving experience. Processes included; 1) hope, 2) active engagement in the recovery journey, 3) engagement with treatment services, and 4) engaging in meaningful activities and relationships. Differences between individuals in the recovered and not recovered group were prevalent in the improving experience stage.ConclusionRecovery in BPD is a non-linear, ongoing process, facilitated by the interaction between stages and processes. Whilst clinical aspects are targets of specialist interventions, greater emphasis on fostering individual motivation, hope, engagement in relationships, activities, and treatment, may be required within clinical practice for a holistic recovery approach

Classical and quantum ergodicity on orbifolds

We extend to orbifolds classical results on quantum ergodicity due to Shnirelman, Colin de Verdi\`ere and Zelditch, proving that, for any positive, first-order self-adjoint elliptic pseudodifferential operator P on a compact orbifold X with positive principal symbol p, ergodicity of the Hamiltonian flow of p implies quantum ergodicity for the operator P. We also prove ergodicity of the geodesic flow on a compact Riemannian orbifold of negative sectional curvature.Comment: 14 page

Dynamics-based centrality for general directed networks

Determining the relative importance of nodes in directed networks is important in, for example, ranking websites, publications, and sports teams, and for understanding signal flows in systems biology. A prevailing centrality measure in this respect is the PageRank. In this work, we focus on another class of centrality derived from the Laplacian of the network. We extend the Laplacian-based centrality, which has mainly been applied to strongly connected networks, to the case of general directed networks such that we can quantitatively compare arbitrary nodes. Toward this end, we adopt the idea used in the PageRank to introduce global connectivity between all the pairs of nodes with a certain strength. Numerical simulations are carried out on some networks. We also offer interpretations of the Laplacian-based centrality for general directed networks in terms of various dynamical and structural properties of networks. Importantly, the Laplacian-based centrality defined as the stationary density of the continuous-time random walk with random jumps is shown to be equivalent to the absorption probability of the random walk with sinks at each node but without random jumps. Similarly, the proposed centrality represents the importance of nodes in dynamics on the original network supplied with sinks but not with random jumps.Comment: 7 figure