107 research outputs found

    Connectivity from source to sink in a lowland area: the Loire river basin (France)

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    Sediment connectivity relates to the transfer of sediments from sources to sinks via runoff and in channel transport. It is highly dependent on spatial variability of landscape properties such as differences in morphology, land use and infiltration/runoff characteristics but may also vary in time due to differences in rainfall amount/intensity and changes in vegetation cover throughout the year. In the Loire river basin, we found that sediment fluxes displayed strong variations in space but also at the interannual and seasonnal time scales (Gay et al. 2013). In this context, our goal is to better understand and quantify hillslope sediment redistributions within this lowland area thanks to the use of semi distributed connectivity approach. To this aim, Borselli's index of connectivity (IC, Borselli et al., 2008) is selected to assess hillslope connectivity at annual and seasonal time scales. Several improvements are proposed to take into account the coupling of the structural landscape connectivity and its hydrosedimentary response. Parameters such as rainfall intensity and differences in seasonal land cover are integrated into the model to account for landscape variations through time. Infiltration and runoff indices were also tested. Preliminary results confirm the variability of landscape connectivity throughout the year. The integration of the index of infiltration and runoff properties of landscape (IDPR) as defined by Mardhel et al. 2004 seems to improve the IC model outputs. From this first step, in-stream sediment connectivity index should be developed for a better understanding and assessment of sediment redistributions at the entire catchment scal

    Differential behaviour of normal, transformed and Fanconi's anemia lymphoblastoid cells to modeled microgravity

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    Background: Whether microgravity might influence tumour growth and carcinogenesis is still an open issue. It is not clear also if and how normal and transformed cells are differently solicited by microgravity. The present study was designed to verify this issue.Methods: Two normal, LB and HSC93, and two transformed, Jurkat and 1310, lymphoblast cell lines were used as representative for the two conditions. Two lymphoblast lines from Fanconi's anemia patients group A and C (FA-A and FA-C, respectively), along with their isogenic corrected counterparts (FA-A-cor and FA-C-cor) were also used. Cell lines were evaluated for their proliferative ability, vitality and apoptotic susceptibility upon microgravity exposure in comparison with unexposed cells. Different parameters correlated to energy metabolism, glucose consumption, mitochondrial membrane potential (MMP), intracellular ATP content, red-ox balance and ability of the cells to repair the DNA damage product 8 OHdG induced by the treatment of the cells with 20 mM KBrO3 were also evaluated.Results: Transformed Jurkat and 1310 cells appear resistant to the microgravitational challenge. On the contrary normal LB and HSC93 cells display increased apoptotic susceptibility, shortage of energy storages and reduced ability to cope with oxidative stress. FA-A and FA-C cells appear resistant to microgravity exposure, analogously to transformed cells. FA corrected cells did shown intermediate sensitivity to microgravity exposure suggesting that genetic correction does not completely reverts cellular phenotype.Conclusions: In the light of the reported results microgravity should be regarded as an harmful condition either when considering normal as well as transformed cells. Modeled microgravity and space-based technology are interesting tools in the biomedicine laboratory and offer an original, useful and unique approach in the study of cellular biochemistry and in the regulation of metabolic pathways

    A case-crossover study of sleep, fatigue, and other transient exposures at workplace and the risk of non-fatal occupational injuries among the employees of an Italian academic hospital

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    Objectives: Transient exposure with acute effect has been shown to affect the risk of occupational injuries in various industrial settings and at the healthcare workplace. The objective of this study has been to identify transient exposures related to occupational injury risk in an Italian teaching hospital. Material and Methods: A case-crossover study was conducted among the employees of the University Hospital of Udine who reported an occupational injury, commuting accident, or incident involving biological risk in a 15-month period in the years 2013 and 2014. The matched-pair interval approach was used to assess the role of acute sleep deprivation whereas the usual frequency approach was used for other 13 transient exposures. Results: Sleep hours were not associated with the risk of injuries whereas a significant risk increase was associated with fatigue, rush, distraction, emergency situations, teaching to or being taught by someone, non-compliant patients, bloody operative/work field, excess noise, complex procedures, and anger. Conclusions: We identified transient exposures that increased the risk of occupational injuries in an Italian teaching hospital, providing indications for interventions to increase workers' safety at the healthcare workplace. Int J Occup Med Environ Health 2016;29(6):1001–100

    Hyaluronan–CD44 interaction hampers migration of osteoclast-like cells by down-regulating MMP-9

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    Osteoclast (OC) precursors migrate to putative sites of bone resorption to form functionally active, multinucleated cells. The preOC FLG 29.1 cells, known to be capable of irreversibly differentiating into multinucleated OC-like cells, displayed several features of primary OCs, including expression of specific integrins and the hyaluronan (HA) receptor CD44. OC-like FLG 29.1 cells adhered to and extensively migrated through membranes coated with fibronectin, vitronectin, and laminins, but, although strongly binding to HA, totally failed to move on this substrate. Moreover, soluble HA strongly inhibited OC-like FLG 29.1 cell migration on the permissive matrix substrates, and this behavior was dependent on its engagement with CD44, as it was fully restored by function-blocking anti-CD44 antibodies. HA did not modulate the cell–substrate binding affinity/avidity nor the expression levels of the corresponding integrins. MMP-9 was the major secreted metalloproteinase used by OC-like FLG 29.1 cells for migration, because this process was strongly inhibited by both TIMP-1 and GM6001, as well as by MMP-9–specific antisense oligonucleotides. After HA binding to CD44, a strong down-regulation of MMP-9 mRNA and protein was detected. These findings highlight a novel role of the HA–CD44 interaction in the context of OC-like cell motility, suggesting that it may act as a stop signal for bone-resorbing cells

    Relevance of CD49d protein expression as overall survival and progressive disease prognosticator in chronic lymphocytic leukemia

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    CD49d/α4-integrin is variably expressed in chronic lymphocytic leukemia (CLL). We evaluated its relevance as independent prognosticator for overall survival and time to treatment (TTT) in a series of 303 (232 for TTT) CLLs, in comparison with other biologic or clinical prognosticators (CD38, ZAP-70, immunoglobulin variable heavy chain (IGHV) gene status, cytogenetic abnormalities, soluble CD23, β2-microglobulin, Rai staging). Flow cytometric detection of CD49d was stable and reproducible, and the chosen cut-off (30% CLL cells) easily discriminated CD49dlow from CD49dhigh cases. CD49d, whose expression was strongly associated with that of CD38 (P < .001) and ZAP-70 (P < .001), or with IGHV mutations (P < .001), was independent prognosticator for overall survival along with IGHV mutational status (CD49d hazard ratio, HRCD49d = 3.52, P = .02; HRIGHV = 6.53, P < .001) or, if this parameter was omitted, with ZAP-70 (HRCD49d = 3.72, P = .002; HRZAP-70 = 3.32, P = .009). CD49d was also a prognosticator for TTT (HR = 1.74, P = .007) and refined the impact of all the other factors. Notably, a CD49dhigh phenotype, although not changing the outcome of good prognosis (ZAP-70low, mutated IGHV) CLL, was necessary to correctly prognosticate the shorter TTT of ZAP-70high (HR = 3.12; P = .023) or unmutated IGHV (HR = 2.95; P = .002) cases. These findings support the introduction of CD49d detection in routine prognostic assessment of CLL patients, and suggest both pathogenetic and therapeutic implications for CD49d expression in CLL

    an ecological study on the association between characteristics of hospital units and the risk of occupational injuries and adverse events on the example of an italian teaching hospital

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    OBJECTIVES: We explored the association of workplace characteristics with occupational injuries and adverse events in an Italian teaching hospital. MATERIAL AND METHODS: This ecological study was conducted using data routinely collected in the University Hospital of Udine, Northeastern Italy. Poisson regression models were used to investigate, at the hospital unit level, the association between 5 outcomes, including: occupational injuries, patient falls, medication errors, other adverse events and near-misses, and various characteristics of the units. RESULTS: The proportion of female workers in a unit, the average number of sick-leave days and of overtime hours, the number of medical examinations requested by employees, and being a surgical unit were significantly associated with some of the outcomes. CONCLUSIONS: Despite ecological nature of the study, which does not allow for inferences to be drawn at the individual level, the results of our study provide useful clues to support strategies and interventions directed towards healthier work environments and better patient care in hospitals. Language: e

    Prognostic impact of ZAP-70 expression in chronic lymphocytic leukemia: mean fluorescence intensity T/B ratio versus percentage of positive cells

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    <p>Abstract</p> <p>Background</p> <p>ZAP-70 is an independent negative prognostic marker in chronic lymphocytic leukemia (CLL). Usually, its expression is investigated by flow cytometric protocols in which the percentage of ZAP-70 positive CLL cells is determined in respect to isotypic control (ISO-method) or residual ZAP-70 positive T cells (T-method). These methods, however, beside suffering of an inherent subjectivity in their application, may give discordant results in some cases. The aim of this study was to assess the prognostic significance of these methods in comparison with another in which ZAP-70 expression was evaluated as a Mean-Fluorescence-Intensity Ratio between gated T and CLL cells (T/B Ratio-method).</p> <p>Methods</p> <p>Cytometric files relative to ZAP-70 determination according to the three readouts were retrospectively reviewed on a cohort of 173 patients (test set), all with complete clinical and biological prognostic assessment and time-to-treatment (TTT) available. Findings were then validated in an independent cohort of 341 cases from a different institution (validation set).</p> <p>Results</p> <p>The optimal prognostic cut-offs for ZAP-70 expression were selected at 11% (ISO-method) or 20% of positive cells (T-method), as well as at 3.0 (T/B Ratio-method) in the test set; these cut-offs yielded 66, 60 and 73 ZAP-70<sup>+ </sup>cases, respectively. Univariate analyses resulted in a better separation of ZAP-70<sup>+ </sup>vs. ZAP-70<sup>- </sup>CLL patients utilizing the T/B Ratio, compared to T- or ISO-methods. In multivariate analyses which included the major clinical and biological prognostic markers for CLL, the prognostic impact of ZAP-70 appeared stronger when the T/B-Ratio method was applied. These findings were confirmed in the validation set, in which ZAP-70 expression, evaluated by the T- (cut-off = 20%) or T/B Ratio- (cut-off = 3.0) methods, yielded 180 or 127 ZAP-70<sup>+ </sup>cases, respectively. ZAP-70<sup>+ </sup>patients according to the T/B Ratio-method had shorter TTT, both if compared to ZAP-70<sup>- </sup>CLL, and to cases classified ZAP-70<sup>+ </sup>by the T-method only.</p> <p>Conclusions</p> <p>We suggest to evaluate ZAP-70 expression in routine settings using the T/B Ratio-method, given the operator and laboratory independent feature of this approach. We propose the 3.0 T/B Ratio value as optimal cut-off to discriminate ZAP-70<sup>+ </sup>(T/B Ratio less than 3.0) from ZAP-70<sup>- </sup>(T/B Ratio more/equal than 3.0) cases.</p

    "This Loose, Drifting Material of Life": Virginia Woolf and Her Experiments in Life-Writing

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    reserved“My God, how does one write a biography?” and “What is a life?” These were Virginia Woolf’s words in a letter to her friend Vita Sackville-West in 1938, echoing her life-long interest in the art of biography and the very essence of life. Woolf’s connection to biography runs deep and can be traced back to her father’s role as the editor of The Dictionary of National Biography. Furthermore, her close association with Lytton Strachey, renowned for his unconventional biographies such as Eminent Victorians (1918), prompted her to explore the genre of life-writing. The purpose of this dissertation is to investigate how biography shaped her development as a life-writer and to delve into her own experimentations with the genre. I will begin by looking at the Victorian landscape of life-writing and the following emergence of the “new biography” movement, led by prominent figures such as Lytton Strachey and Harold Nicolson. In the last chapter, I will discuss two of Woolf's most experimental works, Orlando (1928) and Flush (1933), both subtitled “A biography”. Here Woolf skillfully blends factual accounts of the lives that inspired her with fiction. Orlando is a fantasised biography of Woolf’s close friend Vita Sackville-West, whereas Flush tells the life of the Victorian poet Elizabeth Barrett Browning through the eyes of her dog. These fictitious biographies provide Woolf the creative freedom to mix genres, crafting a form suited to her artistic objectives.“My God, how does one write a biography?” and “What is a life?” These were Virginia Woolf’s words in a letter to her friend Vita Sackville-West in 1938, echoing her life-long interest in the art of biography and the very essence of life. Woolf’s connection to biography runs deep and can be traced back to her father’s role as the editor of The Dictionary of National Biography. Furthermore, her close association with Lytton Strachey, renowned for his unconventional biographies such as Eminent Victorians (1918), prompted her to explore the genre of life-writing. The purpose of this dissertation is to investigate how biography shaped her development as a life-writer and to delve into her own experimentations with the genre. I will begin by looking at the Victorian landscape of life-writing and the following emergence of the “new biography” movement, led by prominent figures such as Lytton Strachey and Harold Nicolson. In the last chapter, I will discuss two of Woolf's most experimental works, Orlando (1928) and Flush (1933), both subtitled “A biography”. Here Woolf skillfully blends factual accounts of the lives that inspired her with fiction. Orlando is a fantasised biography of Woolf’s close friend Vita Sackville-West, whereas Flush tells the life of the Victorian poet Elizabeth Barrett Browning through the eyes of her dog. These fictitious biographies provide Woolf the creative freedom to mix genres, crafting a form suited to her artistic objectives
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