1,449 research outputs found

    Geomorphological control on boulder transport and coastal erosion before, during and after an extreme extra-tropical cyclone

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    This is the final version of the article. Available from Wiley via the DOI in this record.Extreme wave events in coastal zones are principal drivers of geomorphic change. Evidence of boulder entrainment and erosional impact during storms is increasing. However, there is currently poor time coupling between pre- and post-storm measurements of coastal boulder deposits. Importantly there are no data reporting shore platform erosion, boulder entrainment and/or boulder transport during storm events – rock coast dynamics during storm events are currently unexplored. Here, we use high-resolution (daily) field data to measure and characterize coastal boulder transport before, during and after the extreme Northeast Atlantic extra-tropical cyclone Johanna in March 2008. Forty-eight limestone fine-medium boulders (n = 46) and coarse cobbles (n = 2) were tracked daily over a 0.1 km2 intertidal area during this multi-day storm. Boulders were repeatedly entrained, transported and deposited, and in some cases broken down (n = 1) or quarried (n = 3), during the most intense days of the storm. Eighty-one percent (n = 39) of boulders were located at both the start and end of the storm. Of these, 92% were entrained where entrainment patterns were closely aligned to wave parameters. These data firmly demonstrate rock coasts are dynamic and vulnerable under storm conditions. No statistically significant relationship was found between boulder size (mass) and net transport distance. Graphical analyses suggest that boulder size limits the maximum longshore transport distance but that for the majority of boulders lying under this threshold, other factors influence transport distance. Paired analysis of 20 similar sized and shaped boulders in different morphogenic zones demonstrates that geomorphological control affects entrainment and transport distance – where net transport distances were up to 39 times less where geomorphological control was greatest. These results have important implications for understanding and for accurately measuring and modelling boulder entrainment and transport. Coastal managers require these data for assessing erosion risk.This paper benefitted from: comments from J. Hansom, S. Etienne and anonymous reviewers; student volunteers at Atlantic United World College; cartography from Sue Rouillard and Mike Shand; funding from a Royal Geographical Society EPSRC small grant and a NERC grant NE/M010546/1 (Dr Naylor) and an Australian Research Council Discovery grant DP0557205 (Dr Stephenson); permission from the Countryside Council for Wales

    La Responsabilidad Social Corporativa: análisis comparativo de las memorias de una selección de empresas constructoras en Perú y España.

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    El presente estudio realiza un análisis comparativo de la responsabilidad social corporativa (RSC) en empresas constructoras seleccionadas en Perú y España. El objetivo de la investigación es analizar cómo estas empresas reportan su RSC, identificar las problemáticas existentes y confirmar una hipótesis sobre la situación actual. Además, se busca proponer mejoras y recomendaciones para las empresas constructoras en Perú en base a la responsabilidad social corporativa. La metodología utilizada se basa en un análisis comparativo de las memorias de responsabilidad social corporativa de cuatro empresas en Perú y cuatro empresas en España. Se busca identificar los indicadores que se reportan en mayor y menor medida, así como las buenas prácticas y carencias presentes en cada país, para luego comparar los resultados. Los principales resultados confirman la hipótesis planteada, que a través del análisis comparativo se puede determinar las buenas prácticas que se podrían aplicar en las empresas de construcción en Perú, basándonos en la Responsabilidad Social Corporativa. Los resultados también confirman que la situación de las empresas en Perú en cuanto a la forma en que reportan su RSC es inferior en comparación con las empresas en España. Además, se lograron extraer aspectos positivos de las empresas en España que podrían ser aplicados en el contexto peruano. El análisis comparativo de las memorias de RSC permitió obtener resultados satisfactorios, revelando que las empresas en España reportan un mayor número de indicadores, especialmente en el aspecto social, lo que indica una mayor sensibilización en ese país. La contribución de este trabajo radica en el aprendizaje y comprensión de la RSC, así como en la concienciación sobre su importancia para las empresas, a pesar de ser una práctica voluntaria. Se destaca la necesidad de promover la implementación de la RSC en empresas constructoras debido a su gran impacto en la sociedad y en el territorio. En resumen, este estudio comparativo de la RSC en empresas constructoras de Perú y España ofrece una visión de la situación actual, identifica problemáticas y propone recomendaciones para mejorar la implementación de la responsabilidad social corporativa en el contexto peruano

    Delineation of the Innate and Adaptive T-Cell Immune Outcome in the Human Host in Response to Campylobacter jejuni Infection

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    Background: Campylobacter jejuni is the most prevalent cause of bacterial gastroenteritis worldwide. Despite the significant health burden this infection presents, molecular understanding of C. jejuni-mediated disease pathogenesis remains poorly defined. Here, we report the characterisation of the early, innate immune response to C. jejuni using an ex-vivo human gut model of infection. Secondly, impact of bacterial-driven dendritic cell activation on T-cell mediated immunity was also sought.Methodology: Healthy, control paediatric terminal ileum or colonic biopsy tissue was infected with C. jejuni for 8-12 hours. Bacterial colonisation was followed by confocal microscopy and mucosal innate immune responses measured by ELISA. Marked induction of IFN gamma with modest increase in IL-22 and IL-17A was noted. Increased mucosal IL-12, IL-23, IL-1 beta and IL-6 were indicative of a cytokine milieu that may modulate subsequent T-cell mediated immunity. C. jejuni-driven human monocyte-derived dendritic cell activation was followed by analyses of T cell immune responses utilising flow cytometry and ELISA. Significant increase in Th-17, Th-1 and Th-17/Th-1 double-positive cells and corresponding cytokines was observed. The ability of IFN gamma, IL-22 and IL-17 cytokines to exert host defence via modulation of C. jejuni adhesion and invasion to intestinal epithelia was measured by standard gentamicin protection assay.Conclusions: Both innate and adaptive T cell-immunity to C. jejuni infection led to the release of IFN gamma, IL-22 and IL-17A; suggesting a critical role for this cytokine triad in establishing host anti-microbial immunity during the acute and effectors phase of infection. In addition, to their known anti-microbial functions; IL-17A and IL-17F reduced the number of intracellular C. jejuni in intestinal epithelia, highlighting a novel aspect of how IL-17 family members may contribute to protective immunity against C. jejuni

    Perceptions of Barriers to and Facilitators of Participation in Health Research Among Transgender People

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    Purpose: Although transgender people may be at increased risk for a range of health problems, they have been the subject of relatively little health research. An important step toward expanding the evidence base is to understand and address the reasons for nonparticipation and dropout. The aim of this study was to explore the perceptions of barriers to and facilitators of participation in health research among a sample of transgender people in San Francisco, CA, and Atlanta, GA. Methods: Twelve in-person focus groups (FGs) were conducted; six (three with transwomen, three with transmen) were conducted in San Francisco and six FGs were conducted in Atlanta (three with transwomen and three with transmen). FGs were audiorecorded, transcribed, and uploaded to MaxQDA software for analysis. A codebook was used to code transcripts; new codes were added iteratively as they arose. All transcripts were coded by at least 2 of the 4 researchers and, after each transcript was coded, the researchers met to discuss any discrepancies, which were resolved by consensus. Results: Among 67 FG participants, 37 (55%) identified as transmen and 30 (45%) identified as transwomen. The average age of participants was ?41 years (range 18?67) and the majority (61%) were non-Hispanic Whites. Several barriers that can hinder participation in health research were identified, including logistical concerns, issues related to mistrust, a lack of awareness about participation opportunities, and psychosocial/emotional concerns related to being ?outed.? A broad range of facilitators were also identified, including the opportunity to gain knowledge, access medical services, and contribute to the transgender community. Conclusion: These findings provide insights about the perceived barriers to and facilitators of research participation and offer some guidance for researchers in our ongoing effort to engage the transgender community in health research.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140297/1/trgh.2016.0023.pd

    Single-institution comparative study on the outcomes of salvage cryotherapy versus salvage robotic prostatectomy for radio-resistant prostate cancer

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    Background Although primary treatment of localized prostate cancer provides excellent oncologic control, some men who chose radiotherapy experience a recurrence of disease. There is no consensus on the most appropriate management of these patients after radiotherapy failure. In this single-institution review, we compare our oncologic outcome and toxicity between salvage prostatectomy and cryotherapy treatments. Methods From January 2004 to June 2013, a total of 23 salvage procedures were performed. Six of those patients underwent salvage prostatectomy while 17 underwent salvage cryotherapy by two high-volume fellowship-trained urologists. Patients being considered for salvage therapy had localized disease at presentation, a prostate-specific antigen (PSA) 10 years at recurrence, and a negative metastatic workup. Patients were followed to observe cancer progression and toxicity of treatment. Results Patients who underwent salvage cryotherapy were statistically older with a higher incidence of hypertension than our salvage prostatectomy cohort. With a mean follow up of 14.1 months and 7.2 months, the incidence of disease progression was 23.5% and 16.7% after salvage cryotherapy and prostatectomy, respectively. The overall complication rate was also 23.5% versus 16.7%, with the most frequent complication after salvage cryotherapy being urethral stricture and after salvage prostatectomy being severe urinary incontinence. There were no rectal injuries with salvage prostatectomy and one rectourethral fistula in the cohort after salvage cryotherapy. Conclusion While recurrences from primary radiotherapy for prostate cancer do occur, there is no consensus on its management. In our experience, salvage procedures were generally safe and effective. Both salvage cryotherapy and salvage prostatectomy allow for adequate cancer control with minimal toxicity

    One-carbon metabolism in children with marasmus and kwashiorkor

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    BACKGROUND: Kwashiorkor is a childhood syndrome of edematous malnutrition. Its precise nutritional precipitants remain uncertain despite nine decades of study. Remarkably, kwashiorkor\u27s disturbances resemble the effects of experimental diets that are deficient in one-carbon nutrients. This similarity suggests that kwashiorkor may represent a nutritionally mediated syndrome of acute one-carbon metabolism dysfunction. Here we report findings from a cross-sectional exploration of serum one-carbon metabolites in Malawian children. METHODS: Blood was collected from children aged 12-60 months before nutritional rehabilitation: kwashiorkor (N = 94), marasmic-kwashiorkor (N = 43) marasmus (N = 118), moderate acute malnutrition (N = 56) and controls (N = 46). Serum concentrations of 16 one-carbon metabolites were quantified using LC/MS techniques, and then compared across participant groups. FINDINGS: Twelve of 16 measured one-carbon metabolites differed significantly between participant groups. Measured outputs of one-carbon metabolism, asymmetric dimethylarginine (ADMA) and cysteine, were lower in marasmic-kwashiorkor (median µmol/L (± SD): 0·549 (± 0·217) P = 0·00045 & 90 (± 40) P \u3c 0·0001, respectively) and kwashiorkor (0·557 (± 0·195) P \u3c 0·0001 & 115 (± 50) P \u3c 0·0001), relative to marasmus (0·698 (± 0·212) & 153 (± 42)). ADMA and cysteine were well correlated with methionine in both kwashiorkor and marasmic-kwashiorkor. INTERPRETATION: Kwashiorkor and marasmic-kwashiorkor were distinguished by evidence of one-carbon metabolism dysfunction. Correlative observations suggest that methionine deficiency drives this dysfunction, which is implicated in the syndrome\u27s pathogenesis. The hypothesis that kwashiorkor can be prevented by fortifying low quality diets with methionine, along with nutrients that support efficient methionine use, such as choline, requires further investigation. FUNDING: The Hickey Family Foundation, the American College of Gastroenterology, the NICHD, and the USDA/ARS
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