Alewife planktivory controls the abundance of two invasive predatory cladocerans in Lake Michigan

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74873/1/j.1365-2427.2007.01728.x.pd

Application of Metapopulation Theory to Northern Bobwhite Conservation

Northern bobwhite (Colinus virginianus) populations have declined throughout the majority of the species’ range, and have experienced the largest declines in fragmented habitats, suggesting landscape scale processes may be responsible for this decline. We used the results from a stochastic population dynamics model of South Texas bobwhites as conceptual justification for use of metapopulation theory in bobwhite management. Annual quasi-extinction probabilities for isolated bobwhite populations were 0.003 (95% CI: 0.001 0.006), 0.105 (95% CI: 0.083 0.126), and 0.773 (95% CI: 0.750 0.796) for simulated populations harvested at 20, 30, and 40% annually. The probability of regional persistence at 30% harvest increased to ~ 100% in scenarios where we modeled 5 occupied hypothetical 800-ha habitat patches; however, at 40% harvest rates, probability of regional metapopulation persistence did not reach 95% until 12 habitat patches were occupied. This suggests bobwhites probably require somewhere from 800 to 9,600 ha of available habitat space to maintain 95% probability of regional metapopulation persistence as harvest varies from 0 to 40% annually. Our results have strong implications for bobwhite harvest management given the high probability of quasi-extinction of isolated populations at rates of harvest 25%. Multiple patches of habitat (where individual patch size is 800 ha) must be available to ensure bobwhite metapopulation persistence

Genetic Structure and Diversity in South Texas Bobwhites: Implications for Conservation

The northern bobwhite (Colinus virginianus) has experienced range-wide declines in population size and reductions in geographic range during the last century. Declines in northern bobwhite population size and geographic distribution continue to occur despite vigorous conservation and research efforts directed at sustaining and enhancing populations. Viable populations of northern bobwhite have persisted only in areas with large expanses of relatively contiguous habitat, such as southern Texas, parts of Oklahoma, Kansas, and areas in southern Georgia and northern Florida. The decline of northern bobwhite populations is often associated with changes in land- use practices, including proliferation of intensive agriculture and fire suppression, which have altered, removed, or fragmented northern bobwhite habitat. Typically, the effects of changes in land use on northern bobwhites are regional in scale, given the large geographic extent which current agricultural land-use practices, such as farming and timber production, occur. It is clear that precipitation and land use affect regional population trends, but consideration of northern bobwhite population dynamics has remained confined to the local scale. Thus, the specific manner in which land-use changes have affected populations of northern bobwhites is unknown. We investigated the genetics and population structure of northern bobwhites at the landscape scale to learn if bobwhites function as metapopulations. Dispersal and exchange in a metapopulation system are critical to the long-term maintenance of populations; if interrupted, the entire network of populations might collapse. We sampled hunter-harvested northern bobwhites during 2004 to 2007 from 24 sites in South Texas, a region containing large areas of contiguous habitat where populations of northern bobwhites have been relatively stable. We extracted DNA and used bi-parentally and maternally inherited genetic markers to compare genetic structure and diversity among populations. We genotyped 567 individuals at 7 DNA microsatellite loci and sequenced 353 bp of the mtDNA control region for 190 individuals. Genetic diversity was high for microsatellite loci and mtDNA haplotypes (HO 1⁄4 0.58; H 1⁄4 0.88, respectively), and did not differ among populations. We observed little population structure across the geographic region (microsatellite FST 1⁄4 0.01; mtDNA theta 1⁄4 0.037), and Fisher exact tests of population differentiation were not statistically significant. Spatial autocorrelation analysis of the microsatellite data set revealed a positive correlation between Moran’s I and geographic distance out to .50 km. Our genetic data are surprising for an avian species that is considered relatively sedentary and a short-distance disperser. South Texas populations of northern bobwhites had high levels of genetic variation and were genetically similar across a broad region. Population genetics theory predicts that genetic diversity and similarity among local populations in a metapopulation are influenced by the rate of dispersal (gene flow). Life history theory predicts species with high turnover rates, such as northern bobwhite, should be good dispersers. The region-wide genetic similarity among populations of northern bobwhites implies dispersal may be more important in the population dynamics of the species than previous studies have indicated. We hypothesize that disruption of dispersal by habitat fragmentation may explain the overall decline of northern bobwhite populations in some regions. This may explain why patches of suitable habitat in fragmented landscapes go unoccupied by northern bobwhites. Our results lend additional support to recent calls for regional-scale management of this declining species

Taxonomic revision of true morels (Morchella) in Canada and the United States

Recent molecular phylogenetic studies have revealed the existence of at least 50 species of Morchella worldwide and demonstrated a high degree of continental endemism within the genus. Here we describe 19 phylogenetic species of Morchella from North America, 14 of which are new (M. diminutiva, M. virginiana, M. esculentoides, M. prava, M. cryptica, M. frustrata, M. populiphila, M. sextelata, M. septimelata, M. capitata, M. importuna, M. snyderi, M. brunnea and M. septentrionalis). Existing species names (M. rufobrunnea, M. tomentosa, M. punctipes and M. angusticeps) are applied to four phylogenetic species, and formal description of one species (M. sp. Mel-8 ) is deferred pending study of additional material. Methods for assessing morphological features in Morchella are delineated, and a key to the known phylogenetic species of Morchella in North America is provided. Type studies of M. crassistipa, M. hotsonii, M. angusticeps and M. punctipes are provided. Morchella crassistipa is designated nomen dubium

Taxonomic revision of true morels (Morchella) in Canada and the United States

Recent molecular phylogenetic studies have revealed the existence of at least 50 species of Morchella worldwide and demonstrated a high degree of continental endemism within the genus. Here we describe 19 phylogenetic species of Morchella from North America, 14 of which are new (M. diminutiva, M. virginiana, M. esculentoides, M. prava, M. cryptica, M. frustrata, M. populiphila, M. sextelata, M. septimelata, M. capitata, M. importuna, M. snyderi, M. brunnea and M. septentrionalis). Existing species names (M. rufobrunnea, M. tomentosa, M. punctipes and M. angusticeps) are applied to four phylogenetic species, and formal description of one species (M. sp. Mel-8 ) is deferred pending study of additional material. Methods for assessing morphological features in Morchella are delineated, and a key to the known phylogenetic species of Morchella in North America is provided. Type studies of M. crassistipa, M. hotsonii, M. angusticeps and M. punctipes are provided. Morchella crassistipa is designated nomen dubium

Skeletons, Object Shape, Statistics

Objects and object complexes in 3D, as well as those in 2D, have many possible representations. Among them skeletal representations have special advantages and some limitations. For the special form of skeletal representation called “s-reps,” these advantages include strong suitability for representing slabular object populations and statistical applications on these populations. Accomplishing these statistical applications is best if one recognizes that s-reps live on a curved shape space. Here we will lay out the definition of s-reps, their advantages and limitations, their mathematical properties, methods for fitting s-reps to single- and multi-object boundaries, methods for measuring the statistics of these object and multi-object representations, and examples of such applications involving statistics. While the basic theory, ideas, and programs for the methods are described in this paper and while many applications with evaluations have been produced, there remain many interesting open opportunities for research on comparisons to other shape representations, new areas of application and further methodological developments, many of which are explicitly discussed here

Mycoplasma genitalium in the US (MyGeniUS): Surveillance data from sexual health clinics in 4 US regions

BACKGROUND: Mycoplasma genitalium (MG) is on the CDC Watch List of Antimicrobial Resistance Threats, yet there is no systematic surveillance to monitor change. METHODS: We initiated surveillance in sexual health clinics in 6 cities, selecting a quota sample of urogenital specimens tested for gonorrhea and/or chlamydia. We abstracted patient data from medical records and detected MG and macrolide-resistance mutations (MRMs) by nucleic acid amplification testing. We used Poisson regression to estimate adjusted prevalence ratios (aPRs) and 95% CIs, adjusting for sampling criteria (site, birth sex, symptom status). RESULTS: From October-December 2020 we tested 1743 urogenital specimens: 57.0% from males, 46.1% from non-Hispanic Black persons, and 43.8% from symptomatic patients. MG prevalence was 16.6% (95% CI: 14.9-18.5%; site-specific range: 9.9-23.5%) and higher in St Louis (aPR: 1.9; 1.27-2.85), Greensboro (aPR: 1.8; 1.18-2.79), and Denver (aPR: 1.7; 1.12-2.44) than Seattle. Prevalence was highest in persons \u3c18 years (30.4%) and declined 3% per each additional year of age (aPR: .97; .955-.982). MG was detected in 26.8%, 21.1%, 11.8%, and 15.4% of urethritis, vaginitis, cervicitis, and pelvic inflammatory disease (PID), respectively. It was present in 9% of asymptomatic males and 15.4% of asymptomatic females, and associated with male urethritis (aPR: 1.7; 1.22-2.50) and chlamydia (aPR: 1.7; 1.13-2.53). MRM prevalence was 59.1% (95% CI: 53.1-64.8%; site-specific range: 51.3-70.6%). MRMs were associated with vaginitis (aPR: 1.8; 1.14-2.85), cervicitis (aPR: 3.5; 1.69-7.30), and PID cervicitis (aPR: 1.8; 1.09-3.08). CONCLUSIONS: MG infection is common in persons at high risk of sexually transmitted infections; testing symptomatic patients would facilitate appropriate therapy. Macrolide resistance is high and azithromycin should not be used without resistance testing

An international working group consensus report for the prioritization of molecular biomarkers for Ewing sarcoma

The advent of dose intensified interval compressed therapy has improved event-free survival for patients with localized Ewing sarcoma (EwS) to 78% at 5 years. However, nearly a quarter of patients with localized tumors and 60-80% of patients with metastatic tumors suffer relapse and die of disease. In addition, those who survive are often left with debilitating late effects. Clinical features aside from stage have proven inadequate to meaningfully classify patients for risk-stratified therapy. Therefore, there is a critical need to develop approaches to risk stratify patients with EwS based on molecular features. Over the past decade, new technology has enabled the study of multiple molecular biomarkers in EwS. Preliminary evidence requiring validation supports copy number changes, and loss of function mutations in tumor suppressor genes as biomarkers of outcome in EwS. Initial studies of circulating tumor DNA demonstrated that diagnostic ctDNA burden and ctDNA clearance during induction are also associated with outcome. In addition, fusion partner should be a pre-requisite for enrollment on EwS clinical trials, and the fusion type and structure require further study to determine prognostic impact. These emerging biomarkers represent a new horizon in our understanding of disease risk and will enable future efforts to develop risk-adapted treatment