A Novel Population Of Natural Killer Cells Pplays A Critical Role in the Depletion of Splenic B2 B Cells During Experimental Africian Trypanosomiasis

Mice infected with Trypanosoma brucei, the causative agent of human sleeping sickness and a contributor to nagana in cattle, rapidly lose the capacity to mount VSG-specific antibody responses, and die with uncontrolled parasitemia. We have shown (Bockstal et al., 2011, PLOS Pathogens) that the loss of humoral immune competence in the infected mice results from depletion of developing and mature splenic B cells. We now report that T. brucei-induced splenic B cell depletion is dependent upon the presence of the pore forming molecule perforin which is present in the cytotoxic granules of cytotoxic T lymphocytes, natural killer T cells and natural killer cells, occurs in the absence of T cells (and natural killer T cells), i.e., in T cell receptor (αβγδ)-/- mice, but does not occur in intact mice that are depleted of natural killer (NK) cells by treatment with monoclonal antibody specific for the NK1.1 differentiation antigen. In the intact mice, B cells are deleted after remission of the first T. brucei parasitemic wave. At this time natural killer cells are expressing the cytotoxic granule marker CD107a, indicating that they have degranulated, executing their effector function. Moreover, in vitro assays show that B cells from T. brucei infected mice are killed by natural killer cells from uninfected C57BL/6 mice but not efficiently killed by CD107a positive natural killer cells isolated from infected mice, which may be functionally exhausted

Small Business Development Centers: Challanges and Opportunities

The nationwide network of Small Business Development Centers (SBDCs) provides training and assistance to small businesses and nascent entrepreneurs. The academic research to date indicates that SBDCs have a positive impact on national and regional economies and are cost efficient in accomplishing their mission. Other evidence, however, suggests that SBDCs are currently facing  severe challenges that threaten their continued success.  We provide evidence on the scope and severity of these challenges based on the responses of a random sample of SBDC directors. We find that the most pressing issues are funding, attracting and retaining competent counselors, inability to meet demand, obtrusive oversight from the Small Business Administration (SBA) and host institutions, target market problems, and outcome assessment. We offer suggestions for  opportunities to resolve some of the issues noted

Augustana Seniors Fall 1883: Gustaf Sven Swenson

Gustaf Swenson was a senior at Augustana College, Rock Island, Illinois, in the fall of 1883. His name appears in the college catalog of 1883 – 1884, along with his birthplace, the year of his birth, and a few other facts. From this start, we researched the genealogy and family history of Gustaf Swenson. This paper contains a short biography of Gustaf Swenson, a report on his ancestors, a report on his descendants, and some open questions for further research

An Analysis on English Comprehension

Books and Buddies is a program run by Spread the Word Nevada (StWN) designed to help students who struggle with reading. As part of the program, students are given pre and post tests which measure comprehension, accuracy, and words correct per minute (WCPM). A data set was provided that included students\u27 scores on the pre and post test, as well as some general demographic information. A Python program was created to perform linear regressions on subsets of the data, measured on the three attributes listed above. The data was also divided into various categories for the sake of the regressions. This includes improvements based on the number of sessions attended and improvement per grade level. Alongisde the linear regressions, a paired sample mean t-test was performed to test for the significance of the student improvement

An In Vitro Model of the Horse Gut Microbiome Enables Identification of Lactate-Utilizing Bacteria That Differentially Respond to Starch Induction

Laminitis is a chronic, crippling disease triggered by the sudden influx of dietary starch. Starch reaches the hindgut resulting in enrichment of lactic acid bacteria, lactate accumulation, and acidification of the gut contents. Bacterial products enter the bloodstream and precipitate systemic inflammation. Hindgut lactate levels are normally low because specific bacterial groups convert lactate to short chain fatty acids. Why this mechanism fails when lactate levels rapidly rise, and why some hindgut communities can recover is unknown. Fecal samples from three adult horses eating identical diets provided bacterial communities for this in vitro study. Triplicate microcosms of fecal slurries were enriched with lactate and/or starch. Metabolic products (short chain fatty acids, headspace gases, and hydrogen sulfide) were measured and microbial community compositions determined using Illumina 16S rRNA sequencing over 12-hour intervals. We report that patterns of change in short chain fatty acid levels and pH in our in vitro system are similar to those seen in in vivo laminitis induction models. Community differences between microcosms with disparate abilities to clear excess lactate suggest profiles conferring resistance of starch-induction conditions. Where lactate levels recover following starch induction conditions, propionate and acetate levels rise correspondingly and taxa related to Megasphaera elsdenii reach levels exceeding 70% relative abundance. In lactate and control cultures, taxa related to Veillonella montpellierensis are enriched as lactate levels fall. Understanding the microbial dynamics underlying lactic acidosis and laminitis will lead to better informed models of health and the development of a probiotic treatment to prevent acidosis

The planning process of an alternative experimental high school in Watertown, Massachusetts

Thesis (M.C.P.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 1972.Leaf number 21 used twice.Includes bibliographical references.by Samuel Black.M.C.P