340 research outputs found

    The case for spatially-sensitive data: how data structures affect spatial measurement and substantive theory

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    Innovations in GIS and spatial statistics offer exciting opportunities to examine novel questions and to revisit established theory. Realizing this promise requires investment in spatially-sensitive data. Though convenient, widely-used administrative datasets are often spatially insensitive. They limit our ability to conceptualize and measure spatial relationships, leading to problems with ecological validity and the MAUP – with profound implications for substantive theory. I dramatize the stakes using the case of supermarket red-lining in 1970 Chicago. I compare the analytical value of a popular, spatially insensitive administrative dataset with that of a custom-built, spatially sensitive alternative. I show how the former constrains analysis to a single count measure and aspatial regression, while the latter’s point data support multiple measures and spatially-sensitive regression procedures; leading to starkly divergent results. In establishing the powerful impact that spatial measures can exert on our theoretical conclusions, I highlight the perils of relying on convenient, but insensitive datasets. Concomitantly, I demonstrate why investing in spatially sensitive data is essential for advancing sound knowledge of a broad array of historical and contemporary spatial phenomena

    Effect of farnesol on Candida dubliniensis morphogenesis

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    Cell–cell signalling in Candida albicans is a known phenomenon and farnesol was identified as a quorum sensing molecule determining the yeast morphology. The aim of this work was to verify if farnesol had a similar effect on Candida dubliniensis, highlighting the effect of farnesol on Candida spp. morphogenesis. Methods and Results: Two different strains of C. dubliniensis and one of C. albicans were grown both in RPMI 1640 and in serum in the presence of absence of farnesol. At 150 μmol l -1 farnesol the growth rate of both Candida species was not affected. On the contrary, farnesol inhibited hyphae and pseudohyphae formation in C. dubliniensis. Conclusion: Farnesol seems to mediate cell morphology in both Candida species. Significance and Impact of the Study: The effect of farnesol on C. dubliniensis morphology was not reported previously.Fundação para a Ciência e a Tecnologia (FCT

    Making Friends in Violent Neighborhoods: Strategies among Elementary School Children

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    Abstract: While many studies have examined friendship formation among children in conventional contexts, comparatively fewer have examined how the process is shaped by neighborhood violence. The literature on violence and gangs has identified coping strategies that likely affect friendships, but most children in violent neighborhoods are not gang members, and not all friendship relations involve gangs. We examine the friendship-formation process based on in-depth interviews with 72 students, parents, and teachers in two elementary schools in violent Chicago neighborhoods. All students were African American boys and girls ages 11 to 15. We find that while conventional studies depict friendship formation among children as largely affective in nature, the process among the students we observed was, instead, primarily strategic. The children's strategies were not singular but heterogeneous and malleable in nature. We identify and document five distinct strategies: protection seeking, avoidance, testing, cultivating questioners, and kin reliance. Girls were as affected as boys were, and they also reported additional preoccupations associated with sexual violence. We discuss implications for theories of friendship formation, violence, and neighborhood effects

    Surgical Correction in Patients with Lumbar Degenerative Kyphosis Who Had Low Bone Mineral Density: An Analysis of 40 Patients with a Minimum Follow-Up of Two Years

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    Study DesignRetrospective study.PurposeTo investigate influence of bone mineral density (BMD) on the surgical correction of lumbar degenerative kyphosis (LDK).Overview of LiteratureNo studies so far have reported the influence of BMD on the surgical correction of LDK.MethodsForty LDK patients with more than 2 years follow-up were studied. Pelvic incidence (PI), pelvic tilt, sacral slope, sagittal vertical axis (SVA), lumbar lordosis (LL), and thoracic kyphosis were measured preoperatively, immediate postoperatively and at final follow-up. Adverse outcomes: proximal adjacent fractures, sagittal decompensation, pseudoarthrosis, and cage subsidence were documented.ResultsThere were 37 females and 3 males. Average age was 65.1±4.5 years and mean follow-up was 34.2±16.7 months. 42.5% were Takemitsu type 3 curves, 27.5% type 2, 20.0% type 4 and 10.0% type 1. 37.5% had osteopenia, 40.0% osteoporosis and 22.5% had severe osteoporosis. SVA improved from 237.0±96.7 mm preoperatively to 45.3±41.8 mm postoperatively (p=0.000). LL improved from 10.5°±14.7° to -40.6°±10.9° postoperatively (p=0.000). At final follow-up SVA deteriorated to 89.8±72.2 mm and LL to 34.7°±15.8° (p=0.000). The association between late sagittal decompensation, pseudoarthrosis, or proximal adjacent fractures and osteoporosis was insignificant. The difference between immediate postoperative LL and PI (PIDiff) had a significant association with sagittal decompensation and pseudoarthrosis.ConclusionsOsteoporosis did not influence the degree of correction, late sagittal decompensation, proximal adjacent fractures, and pseudoarthrosis in LDK. PIDiff had a significant association with sagittal decompensation and pseudoarthrosis

    Induction chemotherapy in head and neck squamous cell carcinoma of the paranasal sinus and nasal cavity: A role in organ preservation

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    Background/Aims: The role of induction chemotherapy (IC) for eyeball preservation has not been established in head and neck squamous cell carcinoma (HNSCC) of the paranasal sinus and nasal cavity (PNSNC). Periorbital involvement frequently leads to eyeball exenteration with a margin of safety. We evaluated the treatment outcomes, including survival and eyeball preservation, of patients who received IC for HNSCC of the PNSNC. Methods: We reviewed 21 patients diagnosed with HNSCC of the PNSNC who were treated with IC. We analyzed response, eyeball preservation rate, and overall survival. Results: Tumors were located in the paranasal sinus (n = 14) or nasal cavity (n = 7). Most patients had stage T4a (n = 10) or T4b (n = 7) disease. More than half of the patients received a chemotherapy regimen of docetaxel, fluorouracil, and cisplatin (n = 11). Thirteen patients (61.9%) achieved a partial response after IC and 15 patients (71.4%) achieved T down-staging. Among 17 patients with stage T4 disease, which confers a high risk of orbital exenteration, 14 (82.4%) achieved preservation of the involved eye. The 3-year overall survival (OS) rate of patients who achieved a partial response to IC was 84.6%. The 3-year OS rate of patients with stable disease or disease progression after IC was 25.0% (p = 0.038). Conclusions: IC could be considered for down-staging patients with advanced T-stage disease. It could also be a reasonable option for eyeball preservation in locally advanced HNSCC of the PNSNC.

    Occurrence of moulds associated with ovine raw milk and cheeses of the Spanish region of Castilla La Mancha

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    The distribution of mould species was examined at several points of the processing chain in a Manchego cheese plant and associated dairy farms. Geotrichum and Fusarium were the most frequent genera isolated in milk samples as well as in 1-month ripened cheeses, evidencing a direct transfer from raw milk. Conversely, the mycobiota of long-ripened cheeses consisted mainly of Penicillium species, which gained entry to the cheese through the air of ripening rooms. This study contributes to the understanding of the dynamics of fungal populations in semihard and hard cheeses, highlighting that airborne transfer from the stables could have a direct impact on their quality

    One year prospective survey of Candida bloodstream infections in Scotland

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    A 12 month survey of candidaemia in Scotland, UK, in which every Scottish hospital laboratory submitted all blood isolates of yeasts for identification, strain typing and susceptibility testing, provided 300 isolates from 242 patients, generating incidence data of 4.8 cases per 100 000 population per year and 5.9 cases per 100 000 acute occupied bed days; 27.9 % of cases occurred in intensive care units. More than half the patients with candidaemia had an underlying disease involving the abdomen, 78 % had an indwelling intravenous catheter, 62 % had suffered a bacterial infection within the 2 weeks prior to candidaemia and 37 % had undergone a laparotomy. Candida albicans was the infecting species in 50 % of cases, followed by Candida glabrata (21 %) and Candida parapsilosis (12 %). Seven cases of candidaemia were caused by Candida dubliniensis, which was more prevalent even than Candida lusitaniae and Candida tropicalis (six cases each). Among C. glabrata isolates, 55 % showed reduced susceptibility to fluconazole, but azole resistance among other species was extremely low. Multilocus sequence typing showed isolates with high similarity came from different hospitals across the country, and many different types came from the hospitals that submitted the most isolates, indicating no tendency towards hospital-specific endemic strains. Multiple isolates of C. albicans and C. glabrata from individual patients were of the same strain type with single exceptions for each species. The high prevalence of candidaemia in Scotland, relative to other population-based European studies, and the high level of reduced fluconazole susceptibility of Scottish C. glabrata isolates warrant continued future surveillance of invasive Candida infections

    Genetic Variation in OAS1 Is a Risk Factor for Initial Infection with West Nile Virus in Man

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    West Nile virus (WNV) is a re-emerging pathogen that can cause fatal encephalitis. In mice, susceptibility to WNV has been reported to result from a single point mutation in oas1b, which encodes 2′–5′ oligoadenylate synthetase 1b, a member of the type I interferon-regulated OAS gene family involved in viral RNA degradation. In man, the human ortholog of oas1b appears to be OAS1. The ‘A’ allele at SNP rs10774671 of OAS1 has previously been shown to alter splicing of OAS1 and to be associated with reduced OAS activity in PBMCs. Here we show that the frequency of this hypofunctional allele is increased in both symptomatic and asymptomatic WNV seroconverters (Caucasians from five US centers; total n = 501; OR = 1.6 [95% CI 1.2–2.0], P = 0.0002 in a recessive genetic model). We then directly tested the effect of this SNP on viral replication in a novel ex vivo model of WNV infection in primary human lymphoid tissue. Virus accumulation varied markedly among donors, and was highest for individuals homozygous for the ‘A’ allele (P<0.0001). Together, these data identify OAS1 SNP rs10774671 as a host genetic risk factor for initial infection with WNV in humans
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