166 research outputs found

    Increasing Study Abroad Participation Among Historically Excluded Students

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    Higher education has yet to address the deeper causes of inequities in student participation rates in study abroad programs across student demographics. Factors contributing to inequities include disparities in access to social and cultural capital and neglect of identity-related experiences of racially minoritized and first-generation, historically excluded students. This qualitative study examined faculty and staff experiences in the development of study abroad programs and explored their considerations for the needs of historically excluded students. A consensus among interview participants indicated a significant role for intentionality throughout the processes of program development, recruitment outreach, and preparation of students for the study abroad experience

    Development of vegetation over nine years in a planted field station prairie

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    We studied the development of vegetation in a small area at the UWM Field Station planted with prairie species in 1986. The species and quantities of seed and seedlings planted in 1986 were recorded. We sampled the vegetation using permanent quadrats in 1988and 1994. Native prairie species were already well established in the area in 1988. There was, however, a dramatic change in the composition of the vegetation between 1988 and 1994. The number of native prairie species increased slightly and the number of non-prairie species decreased substantially, so that in 1988, 51% of species were native prairie plants and this figure increased to 62% in 1994. The sum of the mean cover of all plant species almost tripled between 1988 and 1994, primarily due to a large increase in cover of grass species. The relative dominance of several species changed markedly over the six years between samples

    Immune activation and suppression by group B streptococcus in a murine model of urinary tract infection

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    Group B streptococcus (GBS) is a common commensal of the gastrointestinal and vaginal mucosa and a leading cause of serious infections in newborns, the elderly, and immunocompromised populations. GBS also causes infections of the urinary tract. However, little is known about host responses to GBS urinary tract infection (UTI) or GBS virulence factors that participate in UTI. Here we describe a novel murine model of GBS UTI that may explain some features of GBS urinary tract association in the human host. We observed high titers and heightened histological signs of inflammation and leukocyte recruitment in the GBS-infected kidney. However, extensive inflammation and leukocyte recruitment were not observed in the bladder, suggesting that GBS may suppress bladder inflammation during cystitis. Acute GBS infection induced the localized expression of proinflammatory cytokines interleukin-1α (IL-1α), macrophage inflammatory protein-1α (MIP-1α), MIP-1β, and IL-9, as well as IL-10, more commonly considered an anti-inflammatory cytokine. Using isogenic GBS strains with different capsule structures, we show that capsular sialic acid residues contribute to GBS urinary tract pathogenesis, while high levels of sialic acid O-acetylation attenuate GBS pathogenesis in the setting of UTI, particularly in direct competition experiments. In vitro studies demonstrated that GBS sialic acids participate in the suppression of murine polymorphonuclear leukocyte (PMN) bactericidal activities, in addition to reducing levels of IL-1α, tumor necrosis factor alpha, IL-1β, MIP-1α, and KC produced by PMNs. These studies define several basic molecular and cellular events characterizing GBS UTI in an animal model, showing that GBS participates simultaneously in the activation and suppression of host immune responses in the urinary tract

    Novel Chromosome Organization Pattern in Actinomycetales-Overlapping Replication Cycles Combined with Diploidy

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    Boehm K, Meyer F, Rhomberg A, Kalinowski J, Donovan C, Bramkamp M. Novel Chromosome Organization Pattern in Actinomycetales-Overlapping Replication Cycles Combined with Diploidy. MBIO. 2017;8(3): e00511-17.Bacteria regulate chromosome replication and segregation tightly with cell division to ensure faithful segregation of DNA to daughter generations. The underlying mechanisms have been addressed in several model species. It became apparent that bacteria have evolved quite different strategies to regulate DNA segregation and chromosomal organization. We have investigated here how the actinobacterium Corynebacterium glutamicum organizes chromosome segregation and DNA replication. Unexpectedly, we found that C. glutamicum cells are at least diploid under all of the conditions tested and that these organisms have overlapping C periods during replication, with both origins initiating replication simultaneously. On the basis of experimental data, we propose growth ratedependent cell cycle models for C. glutamicum. IMPORTANCE Bacterial cell cycles are known for few model organisms and can vary significantly between species. Here, we studied the cell cycle of Corynebacterium glutamicum, an emerging cell biological model organism for mycolic acidcontaining bacteria, including mycobacteria. Our data suggest that C. glutamicum carries two pole-attached chromosomes that replicate with overlapping C periods, thus initiating a new round of DNA replication before the previous one is terminated. The newly replicated origins segregate to midcell positions, where cell division occurs between the two new origins. Even after long starvation or under extremely slow-growth conditions, C. glutamicum cells are at least diploid, likely as an adaptation to environmental stress that may cause DNA damage. The cell cycle of C. glutamicum combines features of slow-growing organisms, such as polar origin localization, and fast-growing organisms, such as overlapping C periods

    Combinatorial small-molecule therapy prevents uropathogenic Escherichia coli catheter-associated urinary tract infections in mice

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    Catheter-associated urinary tract infections (CAUTIs) constitute the majority of nosocomial urinary tract infections (UTIs) and pose significant clinical challenges. These infections are polymicrobial in nature and are often associated with multidrug-resistant pathogens, including uropathogenic Escherichia coli (UPEC). Urinary catheterization elicits major histological and immunological alterations in the bladder that can favor microbial colonization and dissemination in the urinary tract. We report that these biological perturbations impact UPEC pathogenesis and that bacterial reservoirs established during a previous UPEC infection, in which bacteriuria had resolved, can serve as a nidus for subsequent urinary catheter colonization. Mannosides, small molecule inhibitors of the type 1 pilus adhesin, FimH, provided significant protection against UPEC CAUTI by preventing bacterial invasion and shifting the UPEC niche primarily to the extracellular milieu and on the foreign body. By doing so, mannosides potentiated the action of trimethoprim-sulfamethoxazole in the prevention and treatment of CAUTI. In this study, we provide novel insights into UPEC pathogenesis in the context of urinary catheterization, and demonstrate the efficacy of novel therapies that target critical mechanisms for this infection. Thus, we establish a proof-of-principle for the development of mannosides to prevent and eventually treat these infections in the face of rising antibiotic-resistant uropathogens

    Acceptability of Contraceptive Services in the Emergency Department: A Cross-sectional Survey

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    Introduction: Unintended pregnancy disproportionately affects marginalized populations and has significant negative health and financial impacts on women, their families, and society. The emergency department (ED) is a promising alternative setting to increase access to sexual and reproductive health (SRH) services including contraception, especially among marginalized populations. The primary objective of this study was to determine the extent to which adult women of childbearing age who present to the ED would be receptive to receiving contraception and/or information about contraception in the ED. As a secondary objective, we sought to identify the barriers faced in attempting to obtain SRH care in the past. Methods: We conducted a quantitative, cross-sectional, assisted, in-person survey of women aged 18-50 in the ED setting at two large, urban, academic EDs between June 2018-September 2019. The survey was approved by the institutional review board. Survey items included demographics, interest in contraception initiation and/or receiving information about contraception in the ED, desire to conceive, prior SRH care utilization, and barriers to SRH. Results: A total of 505 patients participated in the survey. Participants were predominantly single and Black, with a mean age of 31 years, and reporting not wanting to become pregnant in the next year. Of those participants, 55.2% (n = 279) stated they would be interested in receiving information about birth control AND receiving birth control in the ED if it were available. Of those who reported the ability to get pregnant, and not desiring pregnancy in the next year (n = 279, 55.2%), 32.6% were not currently using anything to prevent pregnancy (n = 91). Only 10.5% of participants stated they had experienced barriers to SRH care in the past (n = 53). Participants who experienced barriers to SRH reported higher interest in receiving information and birth control in the ED (74%, n = 39) compared to those who had not experienced barriers (53%, n = 240); (P = 0.004, 95% confidence interval, 1.30-4.66). Conclusion: The majority of women of childbearing age indicated the desire to access contraception services in the ED setting. This finding suggests favorable patient acceptability for an implementation study of contraception services in emergency care

    The metal ion-dependent adhesion site motif of the Enterococcus faecalis EbpA pilin mediates pilus function in catheter-associated urinary tract infection

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    Though the bacterial opportunist Enterococcus faecalis causes a myriad of hospital-acquired infections (HAIs), including catheter-associated urinary tract infections (CAUTIs), little is known about the virulence mechanisms that it employs. However, the endocarditis- and biofilm-associated pilus (Ebp), a member of the sortase-assembled pilus family, was shown to play a role in a mouse model of E. faecalis ascending UTI. The Ebp pilus comprises the major EbpC shaft subunit and the EbpA and EbpB minor subunits. We investigated the biogenesis and function of Ebp pili in an experimental model of CAUTI using a panel of chromosomal pilin deletion mutants. A nonpiliated pilus knockout mutant (EbpABC(−) strain) was severely attenuated compared to its isogenic parent OG1RF in experimental CAUTI. In contrast, a nonpiliated ebpC deletion mutant (EbpC(−) strain) behaved similarly to OG1RF in vivo because it expressed EbpA and EbpB. Deletion of the minor pilin gene ebpA or ebpB perturbed pilus biogenesis and led to defects in experimental CAUTI. We discovered that the function of Ebp pili in vivo depended on a predicted metal ion-dependent adhesion site (MIDAS) motif in EbpA’s von Willebrand factor A domain, a common protein domain among the tip subunits of sortase-assembled pili. Thus, this study identified the Ebp pilus as a virulence factor in E. faecalis CAUTI and also defined the molecular basis of this function, critical knowledge for the rational development of targeted therapeutics

    Pilin and Sortase Residues Critical for Endocarditis- and Biofilm-Associated Pilus Biogenesis in Enterococcus faecalis

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    Enterococci commonly cause hospital-acquired infections, such as infective endocarditis and catheter-associated urinary tract infections. In animal models of these infections, a long hairlike extracellular protein fiber known as the endocarditis- and biofilm-associated (Ebp) pilus is an important virulence factor for Enterococcus faecalis. For Ebp and other sortase-assembled pili, the pilus-associated sortases are essential for fiber formation as they create covalent isopeptide bonds between the sortase recognition motif and the pilin-like motif of the pilus subunits. However, the molecular requirements governing the incorporation of the three pilus subunits (EbpA, EbpB, and EbpC) have not been investigated in E. faecalis. Here, we show that a Lys residue within the pilin-like motif of the EbpC subunit was necessary for EbpC polymerization. However, incorporation of EbpA into the pilus fiber only required its sortase recognition motif (LPXTG), while incorporation of EbpB only required its pilin-like motif. Only the sortase recognition motif would be required for incorporation of the pilus tip subunit, while incorporation of the base subunit would only require the pilin recognition motif. Thus, these data support a model with EbpA at the tip and EbpB at the base of an EbpC polymer. In addition, the housekeeping sortase, SrtA, was found to process EbpB and its predicted catalytic Cys residue was required for efficient cell wall anchoring of mature Ebp pili. Thus, we have defined molecular interactions involved in fiber polymerization, minor subunit organization, and pilus subcellular compartmentalization in the E. faecalis Ebp pilus system. These studies advance our understanding of unique molecular mechanisms of sortase-assembled pilus biogenesis

    Immune modulation by group B Streptococcus influences host susceptibility to urinary tract infection by uropathogenic Escherichia coli

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    Urinary tract infection (UTI) is most often caused by uropathogenic Escherichia coli (UPEC). UPEC inoculation into the female urinary tract (UT) can occur through physical activities that expose the UT to an inherently polymicrobial periurethral, vaginal, or gastrointestinal flora. We report that a common urogenital inhabitant and opportunistic pathogen, group B Streptococcus (GBS), when present at the time of UPEC exposure, undergoes rapid UPEC-dependent exclusion from the murine urinary tract, yet it influences acute UPEC-host interactions and alters host susceptibility to persistent outcomes of bladder and kidney infection. GBS presence results in increased UPEC titers in the bladder lumen during acute infection and reduced inflammatory responses of murine macrophages to live UPEC or purified lipopolysaccharide (LPS), phenotypes that require GBS mimicry of host sialic acid residues. Taken together, these studies suggest that despite low titers, the presence of GBS at the time of polymicrobial UT exposure may be an overlooked risk factor for chronic pyelonephritis and recurrent UTI in susceptible groups, even if it is outcompeted and thus absent by the time of diagnosis

    Caribbean Corals in Crisis: Record Thermal Stress, Bleaching, and Mortality in 2005

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    BACKGROUND The rising temperature of the world's oceans has become a major threat to coral reefs globally as the severity and frequency of mass coral bleaching and mortality events increase. In 2005, high ocean temperatures in the tropical Atlantic and Caribbean resulted in the most severe bleaching event ever recorded in the basin. METHODOLOGY/PRINCIPAL FINDINGS Satellite-based tools provided warnings for coral reef managers and scientists, guiding both the timing and location of researchers' field observations as anomalously warm conditions developed and spread across the greater Caribbean region from June to October 2005. Field surveys of bleaching and mortality exceeded prior efforts in detail and extent, and provided a new standard for documenting the effects of bleaching and for testing nowcast and forecast products. Collaborators from 22 countries undertook the most comprehensive documentation of basin-scale bleaching to date and found that over 80% of corals bleached and over 40% died at many sites. The most severe bleaching coincided with waters nearest a western Atlantic warm pool that was centered off the northern end of the Lesser Antilles. CONCLUSIONS/SIGNIFICANCE Thermal stress during the 2005 event exceeded any observed from the Caribbean in the prior 20 years, and regionally-averaged temperatures were the warmest in over 150 years. Comparison of satellite data against field surveys demonstrated a significant predictive relationship between accumulated heat stress (measured using NOAA Coral Reef Watch's Degree Heating Weeks) and bleaching intensity. This severe, widespread bleaching and mortality will undoubtedly have long-term consequences for reef ecosystems and suggests a troubled future for tropical marine ecosystems under a warming climate.This work was partially supported by salaries from the NOAA Coral Reef Conservation Program to the NOAA Coral Reef Conservation Program authors. NOAA provided funding to Caribbean ReefCheck investigators to undertake surveys of bleaching and mortality. Otherwise, no funding from outside authors' institutions was necessary for the undertaking of this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
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