306 research outputs found

    The Gender Pay Gap and High-Achieving Women in the Legal Profession

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    Although women have made significant strides in the legal profession, female attorneys continue to earn far less than male attorneys. Relying on survey data from a large sample of full-time attorneys in Texas, we find a gender pay gap of thirty-five thousand dollars at the median that cannot be explained by differences in human capital or occupational segregation. We also provide evidence that the legal market especially disadvantages women who excel in law school. Whereas high academic achievement boosts male lawyers’ incomes substantially, it does not have the same effect on female lawyers’ incomes. High-achieving female lawyers earn less than high-achieving male lawyers across practice settings and earn less than their lower-achieving male counterparts in private practice. We conclude that discrimination in the legal profession operates partly by devaluing female attorneys’ human capital, such that sterling academic credentials and other traits that are valued in men are far less valued in women

    A Descriptive Study of Nursing Home Organizational Culture, Work Environment and Culture Change From the Perspectives of Licensed Nurses

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    Licensed nurses are often identified as a major barrier to the successful implementation of nursing home culture change initiatives, but there is little knowledge of their perceptions of the culture change experience. This study was designed to explore licensed nurses\u27 perceptions of organizational culture and work environment, as well as perceptions of factors that influence the adoption of a specific culture change initiative, the Wellspring Program. All licensed nurses ≥.25 FTE from two nursing homes were invited to complete surveys. Overall response rate was 57% (N=47): 55% from Facility One (n=27) and 61% from Facility Two (n=20). A subset of 13 respondents, targeted for their increased length of tenure in their nursing home, was invited to participate in an interview. Data were triangulated to determine complementarity. Three themes emerged from the data: Confusion over culture change and the role of the licensed nurse, Conflict over the integration of traditional care models with a resident-centered model and Commitment to the resident as an individual and to providing quality nursing care. What is perceived by administrators as nurses\u27 resistance to change may, in fact, be a struggle by licensed nurses to make sense of the motivation and reasoning for changes or to understand the actual changes and their roles in the change process

    Pattern of epithelial cell cycling in hydra

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    We have investigated the spatial pattern of epithelial cell cycling in a mutant strain of Hydra magnipapillata (sf-1). This strain has temperature sensitive interstitial stem cells and thus polyps containing only epithelial cells can be obtained by growth at the restrictive temperature. Epithelial animals were pulse labeled with the thymidine analog 5′-bromo-2′-deoxyuridine (Brdu) and stained with anti-Brdu antibody to visualize S phase cells. Our results indicate that Brdu-labeled cells are broadly and fairly evenly distributed along the body column. Feeding stimulates a rapid decrease and then an increase in labeled cells in gastric tissue; labeled cells in the head are not affected. Starvation leads to a twofold decrease in labeled cells in the gastric region; the density of labeled cells in head tissue remains similar to that in well-fed animals. During bud formation the number of labeled epithelial cells increases significantly in the evaginating bud. During head regeneration the number of labeled cells declines sharply during the first 12 hr and then increases to a density typical of head tissue by 24–36 hr of regeneration. The results indicate the release of signals by feeding and regeneration which inhibit mitosis. By contrast head tissue and developing buds express signals stimulating mitosis. Thus changes in epithelial cell cycling in hydra are closely correlated with morphogenetic events as well as with feeding stimuli

    Fundamental challenges in designing a collaborative travel app

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    The growing capabilities of smartphones have opened up new opportunities for travel coordination and transport is a fertile area for app development. One stream of development is apps that enable collaborative travel, either in the form of lift sharing or collaborative shopping, but despite growing interest from governmental agencies, there is little evidence of the efficacy of such apps. Based on trials of purpose built travel collaboration apps, deployed in tourism, urban and rural residential communities, and logistics, this paper analyses the fundamental challenges facing users adopting such travel apps. The findings suggest that transport practitioners, policy makers and app developers need to better understand the challenges associated with attracting users, the use of incentives and the types of communities most appropriate to implement collaborative travel concepts using such approaches. Also, how the users’ sense of time pressure and the issues around reciprocal exchange can impact on their long-term success and wider adoption

    The Effect of a DNA Damaging Agent on Embryonic Cell Cycles of the Cnidarian Hydractinia echinata

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    The onset of gastrulation at the Mid-Blastula Transition can accompany profound changes in embryonic cell cycles including the introduction of gap phases and the transition from maternal to zygotic control. Studies in Xenopus and Drosophila embryos have also found that cell cycles respond to DNA damage differently before and after MBT (or its equivalent, MZT, in Drosophila). DNA checkpoints are absent in Xenopus cleavage cycles but are acquired during MBT. Drosophila cleavage nuclei enter an abortive mitosis in the presence of DNA damage whereas post-MZT cells delay the entry into mitosis. Despite attributes that render them workhorses of embryonic cell cycle studies, Xenopus and Drosophila are hardly representative of diverse animal forms that exist. To investigate developmental changes in DNA damage responses in a distant phylum, I studied the effect of an alkylating agent, Methyl Methanesulfonate (MMS), on embryos of Hydractinia echinata. Hydractinia embryos are found to differ from Xenopus embryos in the ability to respond to a DNA damaging agent in early cleavage but are similar to Xenopus and Drosophila embryos in acquiring stronger DNA damage responses and greater resistance to killing by MMS after the onset of gastrulation. This represents the first study of DNA damage responses in the phylum Cnidaria

    Two Oppositely Localised Frizzled RNAs as Axis Determinants in a Cnidarian Embryo

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    In phylogenetically diverse animals, including the basally diverging cnidarians, “determinants” localised within the egg are responsible for directing development of the embryonic body plan. Many such determinants are known to regulate the Wnt signalling pathway, leading to regionalised stabilisation of the transcriptional coregulator β-catenin; however, the only strong molecular candidate for a Wnt-activating determinant identified to date is the ligand Wnt11 in Xenopus. We have identified embryonic “oral–aboral” axis determinants in the cnidarian Clytia hemisphaerica in the form of RNAs encoding two Frizzled family Wnt receptors, localised at opposite poles of the egg. Morpholino-mediated inhibition of translation showed that CheFz1, localised at the animal pole, activates the canonical Wnt pathway, promotes oral fates including gastrulation, and may also mediate global polarity in the ectoderm. CheFz3, whose RNA is localised at the egg vegetal cortex, was found to oppose CheFz1 function and to define an aboral territory. Active downregulation mechanisms maintained the reciprocal localisation domains of the two RNAs during early development. Importantly, ectopic expression of either CheFz1 or CheFz3 was able to redirect axis development. These findings identify Frizzled RNAs as axis determinants in Clytia, and have implications for the evolution of embryonic patterning mechanisms, notably that diverse Wnt pathway regulators have been adopted to initiate asymmetric Wnt pathway activation

    Modulation of COUP-TF Expression in a Cnidarian by Ectopic Wnt Signalling and Allorecognition

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    COUP transcription factors are required for the regulation of gene expression underlying development, differentiation, and homeostasis. They have an evolutionarily conserved function, being a known marker for neurogenesis from cnidarians to vertebrates. A homologue of this gene was shown previously to be a neuronal and nematocyte differentiation marker in Hydra. However, COUP-TFs had not previously been studied in a colonial cnidarian.We cloned a COUP-TF homologue from the colonial marine cnidarian Hydractinia echinata. Expression of the gene was analysed during normal development, allorecognition events and ectopic Wnt activation, using in situ hybridisation and quantitative PCR. During normal Hydractinia development, the gene was first expressed in post-gastrula stages. It was undetectable in larvae, and its mRNA was present again in putative differentiating neurons and nematocytes in post-metamorphic stages. Global activation of canonical Wnt signalling in adult animals resulted in the upregulation of COUP-TF. We also monitored a strong COUP-TF upregulation in stolons undergoing allogeneic interactions. COUP-TF mRNA was most concentrated in the tissues that contacted allogeneic, non-self tissues, and decreased in a gradient away from the contact area. Interestingly, the gene was transiently upregulated during initial contact of self stolons, but dissipated rapidly following self recognition, while in non-self contacts high expression levels were maintained.We conclude that COUP-TF is likely involved in neuronal/nematocyte differentiation in a variety of contexts. This has now been shown to include allorecognition, where COUP-TF is thought to have been co-opted to mediate allorejection by recruiting stinging cells that are the effectors of cytotoxic rejection of allogeneic tissue. Our findings that Wnt activation upregulates COUP-TF expression suggests that Wnts' role in neuronal differentiation could be mediated through COUP-TF

    Novel Murine Infection Models Provide Deep Insights into the “Ménage à Trois” of Campylobacter jejuni, Microbiota and Host Innate Immunity

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    BACKGROUND: Although Campylobacter jejuni-infections have a high prevalence worldwide and represent a significant socioeconomic burden, it is still not well understood how C. jejuni causes intestinal inflammation. Detailed investigation of C. jejuni-mediated intestinal immunopathology is hampered by the lack of appropriate vertebrate models. In particular, mice display colonization resistance against this pathogen. METHODOLOGY/PRINCIPAL FINDINGS: To overcome these limitations we developed a novel C. jejuni-infection model using gnotobiotic mice in which the intestinal flora was eradicated by antibiotic treatment. These animals could then be permanently associated with a complete human (hfa) or murine (mfa) microbiota. After peroral infection C. jejuni colonized the gastrointestinal tract of gnotobiotic and hfa mice for six weeks, whereas mfa mice cleared the pathogen within two days. Strikingly, stable C. jejuni colonization was accompanied by a pro-inflammatory immune response indicated by increased numbers of T- and B-lymphocytes, regulatory T-cells, neutrophils and apoptotic cells, as well as increased concentrations of TNF-α, IL-6, and MCP-1 in the colon mucosa of hfa mice. Analysis of MyD88(-/-), TRIF(-/-), TLR4(-/-), and TLR9(-/-) mice revealed that TLR4- and TLR9-signaling was essential for immunopathology following C. jejuni-infection. Interestingly, C. jejuni-mutant strains deficient in formic acid metabolism and perception induced less intestinal immunopathology compared to the parental strain infection. In summary, the murine gut flora is essential for colonization resistance against C. jejuni and can be overcome by reconstitution of gnotobiotic mice with human flora. Detection of C. jejuni-LPS and -CpG-DNA by host TLR4 and TLR9, respectively, plays a key role in immunopathology. Finally, the host immune response is tightly coupled to bacterial formic acid metabolism and invasion fitness. CONCLUSION/SIGNIFICANCE: We conclude that gnotobiotic and "humanized" mice represent excellent novel C. jejuni-infection and -inflammation models and provide deep insights into the immunological and molecular interplays between C. jejuni, microbiota and innate immunity in human campylobacteriosis

    Intestinal Microbiota Shifts towards Elevated Commensal Escherichia coli Loads Abrogate Colonization Resistance against Campylobacter jejuni in Mice

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    Background: The zoonotic pathogen Campylobacter jejuni is a leading cause of bacterial foodborne enterocolitis in humans worldwide. The understanding of immunopathology underlying human campylobacteriosis is hampered by the fact that mice display strong colonization resistance against the pathogen due to their host specific gut microbiota composition. Methodology/Principal Findings: Since the microbiota composition changes significantly during intestinal inflammation we dissected factors contributing to colonization resistance against C. jejuni in murine ileitis, colitis and in infant mice. In contrast to healthy animals C. jejuni could stably colonize mice suffering from intestinal inflammation. Strikingly, in mice with Toxoplasma gondii-induced acute ileitis, C. jejuni disseminated to mesenteric lymphnodes, spleen, liver, kidney, and blood. In infant mice C. jejuni infection induced enterocolitis. Mice suffering from intestinal inflammation and C. jejuni susceptible infant mice displayed characteristical microbiota shifts dominated by increased numbers of commensal Escherichia coli. To further dissect the pivotal role of those distinct microbiota shifts in abrogating colonization resistance, we investigated C. jejuni infection in healthy adult mice in which the microbiota was artificially modified by feeding live commensal E. coli. Strikingly, in animals harboring supra-physiological intestinal E. coli loads, colonization resistance was significantly diminished and C. jejuni infection induced enterocolitis mimicking key features of human campylobacteriosis. Conclusion/Significance: Murine colonization resistance against C. jejuni is abrogated by changes in the microbiot

    Development of the rhopalial nervous system in Aurelia sp.1 (Cnidaria, Scyphozoa)

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    We examined the development of the nervous system in the rhopalium, a medusa-specific sensory structure, in Aurelia sp.1 (Cnidaria, Scyphozoa) using confocal microscopy. The rhopalial nervous system appears primarily ectodermal and contains neurons immunoreactive to antibodies against tyrosinated tubulin, taurine, GLWamide, and FMRFamide. The rhopalial nervous system develops in an ordered manner: the presumptive gravity-sensing organ, consisting of the lithocyst and the touch plate, differentiates first; the “marginal center,” which controls swimming activity, second; and finally, the ocelli, the presumptive photoreceptors. At least seven bilaterally arranged neuronal clusters consisting of sensory and ganglion cells and their neuronal processes became evident in the rhopalium during metamorphosis to the medusa stage. Our analysis provides an anatomical framework for future gene expression and experimental studies of development and functions of scyphozoan rhopalia
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