An Examination of Soil Microbial Communities and Litter Decomposition along an Urbanization Gradient

Urban landscape managers increasingly recognize the critical role of soil organisms in regulating plant nutrient availability through decomposition. Naturalized forested soils are regarded as being balanced in annual organic contributions and the microorganisms responsible for nutrient cycling. Unfortunately, land conversion processes such as urbanization can potentially alter the ability of microorganisms to supply nutrients to plants by changing the organic additions and edaphic properties of soil. However, because the degree of variation in the composition and structure of soil biological communities is not clear in urban areas, baseline information regarding the impact of urban land management practices on soil microbial communities is essential to improve our ability to manage urban soils and the plants they support. This study explored soil bacterial and fungal communities along an urbanization gradient over five urban land-uses: street side terraces, new (< 5 years) residential landscapes receiving intensive management, old (> 25 years) residential landscapes receiving intensive management, old residential landscapes receiving minimal management, and rural forested lands in metropolitan Milwaukee, WI, USA. The objectives were to: 1) determine if urbanization initiates changes bacterial and fungal community composition and microbial biomass across five urban land-uses, 2) determine if urbanization initiates changes biological activity across five urban land-uses, 3) determine if urbanization initiates changes the soil physical and chemical environment across five urban land-uses, and 4) determine if differences in the bacterial and fungal compositions are related to differences in the soil’s physical and chemical characteristics. Microbial biomass did not differ along the urbanization gradient. The PLFA/FAME produced microbial communities showed statistical differences in biodiversity index values by land-use; however, analysis of similarities (ANOSIM) and multidimensional scaling (MDS) indicated highly similar communities with limited separation. The TRFLP inferred bacterial and fungal communities showed some land-use differences based on ANOSIM, MDS, and analysis of biodiversity indices. However, the discrete land-use clusters grouped closely from large-scale similarities in community profiles. Therefore, observed differences in microbial community composition reflected only a small portion of the total microbial biomass. The decomposition of transposed leaf litter showed significant decline in C:N ratio over time, but no statistical differences by land-use were observed. The soil edaphic properties (bulk density, soil organic matter, pH, Mg, Na, total N, and C:N ratio) displayed significant differences across the urbanization gradient. Additionally, Mg and total N we correlated to changes in the bacterial communities. Consequently, in locations where parent material and soil forming processes are homogeneous, urbanization and landscape management appears to have less impact on soil microbiology than initially expected.The International Society of Arboriculture John Hyland Gran

Dendritic Cells Induce MUC1 Expression and Polarization on Human T Cells by an IL-7-Dependent Mechanism

Abstract The MUC1 transmembrane mucin is expressed on the surface of activated human T cells; however, the physiologic signals responsible for the regulation of MUC1 in T cells are not known. The present studies demonstrate that IL-7, but not IL-2 or IL-4, markedly induces MUC1 expression on CD3+ T cells. MUC1 was also up-regulated by IL-15, but to a lesser extent than that found with IL-7. The results show that IL-7 up-regulates MUC1 on CD4+, CD8+, CD25+, CD69+, naive CD45RA+, and memory CD45RO+ T cells. In concert with induction of MUC1 expression by IL-7, activated dendritic cells (DC) that produce IL-7 up-regulate MUC1 on allogeneic CD3+ T cells. DC also induce MUC1 expression on autologous CD3+ T cells in the presence of recall Ag. Moreover, DC-induced MUC1 expression on T cells is blocked by a neutralizing anti-IL-7 Ab. The results also demonstrate that DC induce polarization of MUC1 on T cells at sites opposing the DC-T cell synapse. These findings indicate that DC-mediated activation of Ag-specific T cells is associated with induction and polarization of MUC1 expression by an IL-7-dependent mechanism.</jats:p

Discriminating Among Pacific Salmon, Rainbow Trout, and Atlantic Salmon Species Using Common Genetic Screening Methods

Abstract The five most common species of Pacific salmon, Rainbow Trout (steelhead) Oncorhynchus spp., and Atlantic Salmon Salmo salar intermingle in the North Pacific Ocean and its freshwater tributaries. Efficient morphological methods for distinguishing among these species are sometimes limited by condition of the specimen (degraded or missing morphology), life history stage, or training of the observer. Researchers have successfully applied various genetic methods to distinguish among these species when morphological analyses are not possible, but they cannot easily incorporate these methods into standard fish and wildlife population monitoring analysis workflows. Here we test five 5′–3′ exonuclease (TaqMan) assays developed from mitochondrial genes and provide novel methods that take advantage of TaqMan output to distinguish among these species. We found that combinations of as few as two of the five assays were adequate to distinguish all species. TaqMan chemistry is designed to interrogate a single nucleotide locus. We also explore the basis for the variation in the observed scatter plot distributions (variation in florescent signals) and show that this variation is due to nucleotide diversity in and near the probe site. Because the SNPs underlying the assays developed here are all physically close to one another along the mitochondrial genome, the potential exists to develop a single DNA sequence-based assay to discriminate among salmon species. This single assay can be added to a genotyping-by-sequencing panel to identify and exclude nontarget species from analyses.</jats:p

Paranasal Meningioma in a Horse

Paranasal meningioma was diagnosed in a 5-year-old Appaloosa gelding. The mass occupied the right maxillary, frontal, and sphenopalatine sinuses but did not invade the calvarium. The diagnosis was based on histologic evaluation, positive immunohistochemical staining for vimentin and cytokeratin, and ultrastructural features including the presence of interdigitating spindle cells with numerous desmosomes. </jats:p

The genetic composition of wild recruits in a recovering lake trout population in Lake Michigan

Strain performance evaluations are vital for developing successful fishery management and restoration strategies. Here, we utilized genotypes from 36 microsatellites to investigate hatchery strain contribution to collections of naturally produced lake trout (Salvelinus namaycush) sampled across Lake Michigan. Strain composition varied by area, with recoveries of Seneca Lake strain exceeding expectations based on stocking records in northern Lake Michigan but performing similarly to other strains in southern Lake Michigan. Interstrain hybrids were present at moderate frequencies similar to expectations based on simulations, suggesting that strains are interbreeding randomly. We hypothesize that the superior performance of the Seneca Lake strain in northern Lake Michigan is partially due to adaptive advantages that facilitate increased survival in areas with high mortality from sea lamprey (Petromyzon marinus) predation, such as northern Lake Michigan. However, when this selective pressure is lessened, the Seneca Lake strain performs similarly to other strains. Our study demonstrates that strain performance can vary across small spatial scales and illustrates the importance of conducting thorough strain evaluations to inform management and conservation.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