New interpretations of fine-scale spatial genetic structure

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72211/1/j.1365-294X.2008.03728.x.pd

Characterization of twenty-six microsatellite markers for the tropical pioneer tree species Cecropia insignis Liebm (Urticaceae)

Cecropia insignis is an ecologically important Neotropical pioneer tree and major vertebrate food source. Although this species is relatively common in faunally intact tropical rainforests, its population dynamics may be negatively impacted by hunting of seed-dispersing animals. To better understand gene flow and regeneration dynamics in C. insignis, we characterized 26 microsatellite markers in a population sampled from Barro Colorado Island, Panama. Eleven loci of C3 alleles were tested on 48 individuals, whereas the remaining 15 loci of two alleles were tested on 12 individuals. Allelic richness ranged from 2 to 9 per locus. Observed and expected heterozygosity averaged 0.478 and 0.440 respectively. Polymorphism information content was between 0.141 and 0.757. Only two loci exhibited deviation from Hardy–Weinberg proportions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109362/1/Wei&Dick2014Cecropia.pdf85Description of Wei&Dick2014Cecropia.pdf : main articl

Storage dynamics in hydropedological units control hillslope connectivity, runoff generation, and the evolution of catchment transit time distributions

Acknowledgments We thank the European Research Council (ERC; project GA 335910 VEWA) and Natural Environment Research Council (NERC; project NE/K000268/1) for funding. We would like to thank Konrad Piegat for invaluable help with the fieldwork. Iain Malcolm and staff at Marine Scotland (Pitlochry) are also thanked for the provision of data from the AWS. We also thank three anonymous reviewers for their constructive comments.Peer reviewedPublisher PD

RESEARCH PAPER Genomic evidence of a widespread southern distribution during the Last Glacial Maximum for two eastern North American hickory species

Aim: Phylogeographical studies of temperate forest taxa often infer complex histories involving population subdivision into distinct refugia during the Last Glacial Maximum (LGM). However, some temperate deciduous trees may have been broadly distributed in southeastern North America during the LGM. We investigate genome-wide genetic structure in two widespread eastern North American tree species to determine if range expansion from genetically isolated refugia or from a broader, less genetically subdivided region better explains their post-glacial history. Location: Eastern North America (ENA). Taxa: Bitternut hickory (Carya cordiformis [Wangenh.] K.Koch) and shagbark hickory (Carya ovata [Mill.] K.Koch). Methods: Genetic diversity and differentiation indices were calculated from >1,000 nuclear SNP loci genotyped in ca. 180 individuals per species sampled across ENA. Genetic structure was investigated using principle component analysis and genetic clustering algorithms. As an additional tool for inference, areas of suitable habitat during the LGM were predicted using species distribution models (SDMs). Results: Populations across all latitudes showed similar levels of genetic diversity. Most genetic variation was weakly differentiated across ENA, with the exception of an outlier population of Carya ovata in Texas. Genetic structure in each species exhibited an isolation-by-distance pattern. SDMs predicted high LGM habitat suitability over much of the southeastern United States. Main conclusions: Both hickory species likely survived the LGM in low-density populations that were broadly distributed across southeastern North America and not highly genetically differentiated, except that the range-edge Texas population of Carya ovata may represent a separate glacial refugium. Over most of ENA, genetic structure in both species is best explained by simple latitudinal range shifts and high gene flow among populations, rather than expansions from multiple, genetically isolated refugia as is characteristic of taxa from other Northern Hemisphere temperate regions of the world.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/144211/1/Bemmels_et_al-2018-Journal_of_Biogeography.pdf85Description of Bemmels_et_al-2018-Journal_of_Biogeography.pdf : main articl

Improved inapproximability factors for some Σ^p₂ minimization problems

We give improved inapproximability results for some minimization problems in the second level of the Polynomial-Time Hierarchy. Extending previous work by Umans [Uma99], we show that several variants of DNF minimization are Σ^p₂-hard to approximate to within factors of n^(1/3−ϵ) and ^(n1/2−ϵ) (where the previous results achieved n^(1/4−ϵ)), for arbitrarily small constant ϵ > 0. For one problem shown to be inapproximable to within n^(1/2−ϵ), we give a matching O(n^(1/2))-approximation algorithm, running in randomized polynomial time with access to an NP oracle, which shows that this result is tight assuming the PH doesn't collapse

Polymorphic microsatellite markers for a wind‐dispersed tropical tree species, Triplaris cumingiana (Polygonaceae)

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141549/1/aps31400051.pd

Multilateral Medical Operations Panel's Acoustics Sub-Working Group for the International Space Station

No abstract availabl

Exon Primed, Intron Crossing (EPIC) markers for evolutionary studies of Ficus and other taxa in the fig family (Moraceae)

• Premise of the study: The genus Ficus (fi g trees) comprises ca. 750 species of trees, vines, and stranglers found in tropical forests throughout the world. Fig trees are keystone species in many tropical forests, and their relationship with host-specific wasp pollinators has received much attention, although many questions remain unresolved regarding the levels of host specificity,cospeciation, and the role of hybridization in fig and wasp speciation. We developed exon-primed intron-crossing (EPIC)markers to obtain phylogenetic resolution needed to address these questions. • Methods and Results: Expressed sequence tags (ESTs) from F. elastica were compared to Arabidopsis and Populus genomes to locate introns and to design primers in flanking exons. Primer pairs for 80 EPIC markers were tested in samples from divergent clades within Ficus and the outgroup Poulsenia (Moraceae). • Conclusions: Thirty-one EPIC markers were successfully sequenced across Ficus , and 29 of the markers also amplified in Poulsenia , indicating broad transferability within Moraceae. All of the EPIC markers were polymorphic and showed levels of polymorphism similar to that of the widely used internal transcribed spacer (ITS).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/100185/1/Yao2013.pd

Risk Management Practices in the Mining Sector of Ghana: The Case of Goldfield Ltd, Damang

Risk management practice, in developing countries, is at its infant stage and often neglected in most companies. This study focused on the risk management practices of Goldfield Ltd in Damang in the Western Region of Ghana. Questionnaires were employed as the data collection instruments. The study made use of quantitative survey design. All the 41 staff who directly dealt with risk and its management in the company were considered and made part of the study. The breakdown of the 41 staff members used for the study includes 6 Heads of Departments, 10 Superintendent, 10 Supervisors and 15 Contractors. Employing a quantitative descriptive survey design, the result of the study reveals that risk assessment tools used for risk management are probability method, qualitative and decision tools. The recommendations made were to for mine management to place equal attention to all the methods for risk assessment. Keywords: risk, risk management, safety, mining, Goldfiel