Description of a new species of cryptic snubnose darter (Percidae: Etheostomatinae) endemic to north-central Mississippi

Many subclades within the large North American freshwater fish genus Etheostoma (Percidae) show brilliant male nuptial coloration during the spring spawning season. Traditionally, perceived differences in color were often used to diagnose closely related species. More recently, perceived differences in male nuptial color have prompted further investigation of potential biodiversity using genetic tools. However, cryptic diversity among Etheostoma darters renders male nuptial color as unreliable for detecting and describing diversity, which is foundational for research and conservation efforts of this group of stream fishes. Etheostoma raneyi (Yazoo Darter) is an imperiled, range-limited fish endemic to north-central Mississippi. Existing genetic evidence indicates cryptic diversity between disjunctly distributed E. raneyi from the Little Tallahatchie and Yocona river watersheds despite no obvious differences in male color between the two drainages. Analysis of morphological truss and geometric measurements and meristic and male color characters yielded quantitative differences in E. raneyi from the two drainages consistent with genetic evidence. Morphological divergence is best explained by differences in stream gradients between the two drainages. Etheostoma faulkneri, the Yoknapatawpha Darter, is described as a species under the unified species concept. The discovery of cryptic diversity within E. raneyi would likely not have occurred without genetic tools. Cryptic diversity among Etheostoma darters and other stream fishes is common, but an overreliance on traditional methods of species delimitation (e.g., identification of a readily observable physical character to diagnose a species) impedes a full accounting of the diversity in freshwater fishes in the southeastern United States

Cryptic diversity among Yazoo Darters (Percidae: Etheostoma raneyi) in disjunct watersheds of northern Mississippi

© Copyright 2020 Nasser et al. The Yazoo Darter, Etheostoma raneyi (Percidae), is an imperiled freshwater fish species endemic to tributaries of the Yocona and Little Tallahatchie rivers of the upper Yazoo River basin, in northern Mississippi, USA. The two populations are allopatric, isolated by unsuitable lowland habitat between the two river drainages. Relevant literature suggests that populations in the Yocona River represent an undescribed species, but a lack of data prevents a thorough evaluation of possible diversity throughout the range of the species. Our goals were to estimate phylogenetic relationships of the Yazoo Darter across its distribution and identify cryptic diversity for conservation management purposes. Maximum likelihood (ML) phylogenetic analyses of the mitochondrial cytochrome b (cytb) gene returned two reciprocally monophyletic clades representing the two river drainages with high support. Bayesian analysis of cytb was consistent with the ML analysis but with low support for the Yocona River clade. Analyses of the nuclear S7 gene yielded unresolved relationships among individuals in the Little Tallahatchie River drainage with mostly low support, but returned a monophyletic clade for individuals from the Yocona River drainage with high support. No haplotypes were shared between the drainages for either gene. Additional cryptic diversity within the two drainages was not indicated. Estimated divergence between Yazoo Darters in the two drainages occurred during the Pleistocene (\u3c1 million years ago) and was likely linked to repeated spatial shifts in suitable habitat and changes in watershed configurations during glacial cycles. Individuals from the Yocona River drainage had lower genetic diversity consistent with the literature. Our results indicate that Yazoo Darters in the Yocona River drainage are genetically distinct and that there is support for recognizing Yazoo Darter populations in the Yocona River drainage as a new species under the unified species concept

Fine-scale Explosive Energy Release at Sites of Prospective Magnetic Flux Cancellation in the Core of the Solar Active Region Observed by Hi-C 2.1, IRIS, and SDO

The second Hi-C flight (Hi-C 2.1) provided unprecedentedly high spatial and temporal resolution (~250 km, 4.4 s) coronal EUV images of Fe ix/x emission at 172 Å of AR 12712 on 2018 May 29, during 18:56:21–19:01:56 UT. Three morphologically different types (I: dot-like; II: loop-like; III: surge/jet-like) of fine-scale sudden-brightening events (tiny microflares) are seen within and at the ends of an arch filament system in the core of the AR. Although type Is (not reported before) resemble IRIS bombs (in size, and brightness with respect to surroundings), our dot-like events are apparently much hotter and shorter in span (70 s). We complement the 5 minute duration Hi-C 2.1 data with SDO/HMI magnetograms, SDO/AIA EUV images, and IRIS UV spectra and slit-jaw images to examine, at the sites of these events, brightenings and flows in the transition region and corona and evolution of magnetic flux in the photosphere. Most, if not all, of the events are seated at sites of opposite-polarity magnetic flux convergence (sometimes driven by adjacent flux emergence), implying likely flux cancellation at the microflare's polarity inversion line. In the IRIS spectra and images, we find confirming evidence of field-aligned outflow from brightenings at the ends of loops of the arch filament system. In types I and II the explosion is confined, while in type III the explosion is ejective and drives jet-like outflow. The light curves from Hi-C, AIA, and IRIS peak nearly simultaneously for many of these events, and none of the events display a systematic cooling sequence as seen in typical coronal flares, suggesting that these tiny brightening events have chromospheric/transition region origin

Long-acting injectable Cabotegravir + Rilpivirine for HIV maintenance therapy: Week 48 pooled analysis of phase 3 ATLAS and FLAIR trials

BACKGROUND: Long-acting (LA) injectable regimens are a potential therapeutic option in people living with HIV-1. SETTING: ATLAS (NCT02951052) and FLAIR (NCT02938520) were 2 randomized, open-label, multicenter, multinational phase 3 studies. METHODS: Adult participants with virologic suppression (plasma HIV-1 RNA <50 copies/mL) were randomized (1:1) to continue with their current antiretroviral regimen (CAR) or switch to the long-acting (LA) regimen of cabotegravir (CAB) and rilpivirine (RPV). In the LA arm, participants initially received oral CAB + RPV once-daily for 4 weeks to assess individual safety and tolerability, before starting monthly injectable therapy. The primary endpoint of this combined analysis was antiviral efficacy at week 48 (FDA Snapshot algorithm: noninferiority margin of 4% for HIV-1 RNA ≥50 copies/mL). Safety, tolerability, and confirmed virologic failure (2 consecutive plasma HIV-1 RNA ≥200 copies/mL) were secondary endpoints. RESULTS: The pooled intention-to-treat exposed population included 591 participants in each arm [28% women (sex at birth), 19% aged ≥50 years]. Noninferiority criteria at week 48 were met for the primary (HIV-1 RNA ≥50 copies/mL) and key secondary (HIV-1 RNA <50 copies/mL) efficacy endpoints. Seven individuals in each arm (1.2%) developed confirmed virologic failure; 6/7 (LA) and 3/7 (CAR) had resistance-associated mutations. Most LA recipients (83%) experienced injection site reactions, which decreased in incidence over time. Injection site reactions led to the withdrawal of 6 (1%) participants. The serious adverse event rate was 4% in each arm. CONCLUSION: This combined analysis demonstrates monthly injections of CAB + RPV LA were noninferior to daily oral CAR for maintaining HIV-1 suppression

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

End-Stage Renal Disease Among HIV-Infected Adults in North America

Background. Human immunodeficiency virus (HIV)-infected adults, particularly those of black race, are at high-risk for end-stage renal disease (ESRD), but contributing factors are evolving. We hypothesized that improvements in HIV treatment have led to declines in risk of ESRD, particularly among HIV-infected blacks

Fragmentation Alters Ecological Gradients and Headwater Fish Assemblage Composition Relative to Land Use In a Dendritic System

The spatial and hydrological properties of headwaters allow dendritic systems to contribute to patterns of regional diversity. However, such ecological gradients may be disrupted as a result of habitat fragmentation. We tested the hypothesis that coarse-scale anthropogenic disturbances such as upstream land use and proximity to reservoirs can alter ecological gradients, thus influencing instream habitat, headwater fish assemblage composition, and species turnover in the Little Tallahatchie River system in north-central Mississippi. To test this hypothesis, we calculated species turnover coefficients, ordinated samples, and examined the correlations between assemblage composition and environmental and anthropogenic variables. Assemblage composition was strongly correlated with instream habitat and river system connectivity, and instream habitat was strongly associated with land use. Gradients in assemblage composition associated with ecological factors were altered due to land use. Our research highlights the importance of headwaters as distinctive habitat patches driving species turnover and the influence of land use in disrupting the ecological gradients that allow for the formation of these distinctive habitat types

Fragmentation alters ecological gradients and headwater fish assemblage composition relative to land use in a dendritic river system

The spatial and hydrological properties of headwaters allow dendritic systems to contribute to patterns of regional diversity. However, such ecological gradients may be disrupted as a result of habitat fragmentation. We tested the hypothesis that coarse-scale anthropogenic disturbances such as upstream land use and proximity to reservoirs can alter ecological gradients, thus influencing instream habitat, headwater fish assemblage composition, and species turnover in the Little Tallahatchie River system in north-central Mississippi. To test this hypothesis, we calculated species turnover coefficients, ordinated samples, and examined the correlations between assemblage composition and environmental and anthropogenic variables. Assemblage composition was strongly correlated with instream habitat and river system connectivity, and instream habitat was strongly associated with land use. Gradients in assemblage composition associated with ecological factors were altered due to land use. Our research highlights the importance of headwaters as distinctive habitat patches driving species turnover and the influence of land use in disrupting the ecological gradients that allow for the formation of these distinctive habitat types.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

High throughput sequencing enables discovery of microsatellites from the puff-throated bulbul (\u3ci\u3eAlophoixus pallidus\u3c/i\u3e) and assessment of genetic diversity in Khao Yai National Park, Thailand

Bulbuls (family Pycnonotidae) are a diverse family of songbirds that carry out a number of ecologically important functions associated with seed dispersal. Since, 2003, a puffthroated bulbul (Alophoixus pallidus) population in the Mo-Singto Long-term Biodiversity Research Plot in Khao Yai National Park, Thailand has served as a model system for examining how bulbul behavior, movement, and demographics affect Southeast Asian forests. In this study, we used 454 pyrosequencing to discover microsatellites from A. pallidus that will enable the long-term mark-recapture work conducted at Mo-Singto to be complemented by molecular ecology and population genetic studies. In addition, we conducted fragment analysis to examine the level of genetic diversity exhibited by the Mo- Singto population. In total, we identified 103 DNA fragments containing microsatellite repeats and 66 fragments with sufficient flanking sequences to allow for primer design. Upon screening 26 loci via PCR-based genotyping assays, we identified nine polymorphic loci and used eight of these to examine genetic diversity in the Mo-Singto population. The results of these analyses suggest that the Mo-Singto population is moderately diverse (mean number of effective alleles across eight loci = 3.36, standard deviation = 1.78), is more-or-less in Hardy–Weinberg equilibrium, and has not recently been subject to severe population reduction