158 research outputs found

    ModĂ©lisation statistique des apports de MES associĂ©s au rĂ©gime des crues d’un sous- bassin du Timis-BĂ©ga (Roumanie)

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    Dans cette thĂ©matique concernant le transport solide des cours d’eau, il nous semble opportun de rĂ©sumer le cadre gĂ©nĂ©ral et d’y situer notre approche. Les formules classiques du transport solide Ă©valuent le dĂ©bit en matĂ©riaux du lit (charriage et suspension) Ă  partir de ses dĂ©formations. Elles ne permettent pas d’estimer le dĂ©bit des matĂ©riaux provenant directement du lessivage des versants et qui transite sans interaction avec le lit. Dans cet article, nous considĂ©rons uniquement la phase en suspension "MES" mesurĂ©e sans distinction Ă  priori de l’origine des grains qui la constitue : provenance directe du bassin versant (phase directe) et (ou) reprise des stocks disponibles dans le lit (phase diffĂ©rĂ©e). Le bassin hydrographique du Timis-BĂ©ga (Roumanie) est particuliĂšrement bien Ă©quipĂ© pour le suivi des dĂ©bits de 28 sous bassins et le contrĂŽle des flux de MES de douze d’entre eux. De plus, son contexte physiographique nous permet de penser que la phase directe est prĂ©pondĂ©rante. Le protocole de mesure des flux de MES prĂ©voit, entre autres, une densification variable des observations selon l’intensitĂ© des crues liquides. Ces considĂ©rations prĂ©cĂ©dentes nous permettent d’envisager une modĂ©lisation statistique des apports solides en MES des sous-bassins du Timis-BĂ©ga. Celle-ci est directement inspirĂ©e des connaissances acquises sur la modĂ©lisation statistique "QdF" des rĂ©gimes hydrologiques des bassins versants. Sur l’exemple du sous-bassin du BĂ©ga Ă  Balint, qui draine une superficie de 1064 km2, nous retiendrons deux principaux rĂ©sultats issus de la transposition du concept QdF aux dĂ©bits solides QMESdF : Les analyses statistiques des rĂ©gimes liquide et solide montrent que les dĂ©bits solides de MES ne sont pas simplement proportionnels aux dĂ©bits liquides mais croissent plus rapidement. Les deux lois de distributions privilĂ©giĂ©es, Pareto gĂ©nĂ©ralisĂ©e pour les MES et exponentielle pour les dĂ©bits, permettent de le justifier. Le temps de montĂ©e des hydrogrammes de projet liquide ou solide est quasiment identique, autrement dit nous vĂ©rifions la quasi concomitance de leurs dĂ©bits de pointe. Ce rĂ©sultat n’est possible que si le dĂ©bit solide de MES provient essentiellement du lessivage des versants, ce qui Ă©tait supposĂ© Ă  priori.With respect to sediment transport, we detailed the general framework and how our approach contributes to these developments. Starting from the single traditional relation for the bed material load, specialists in river hydraulics cannot assess sediment yield of basins, when it involves the auto-suspension of fine sediments coming mainly from slope erosion (wash load). This latter estimate is needed for simulating the transfer of sediments and possible deposition in certain areas, particularly when a strong slowing down occurs. The Timis-Bega drainage basin (Romania) is fairly well equipped for the monitoring of discharge and suspended materials (sediment discharge). The hydrometric network includes 28 stations, of which 12 allow a monitoring of wash load. Moreover, its physiographic characteristics led us to think that the wash load dominates. Thus we assumed that sediment discharge was correlated with the physiographic features of the catchment area. The protocol for the measurement of the suspended sediment load was intensified during the floods. Thus, statistical modelling of the sub-basin sediment yields could be performed.The current study was directly inspired by the knowledge obtained in the domain of statistical modelling that describes hydrological regimes. The approach adopted was based on the flood-duration-frequency (QdF) analysis that takes into account the temporal variability of floods. The QdF approach analyses maximum average flows (Vd) over various durations (d), equivalent to intensity-duration-frequency (IdF) curves commonly used for rainfall analysis. The proposed model allows QdF curves V(d, T) for a given basin to be estimated using a minimum number of parameters. When the statistical law is the exponential law, this model contains only three parameters, due to observed scale invariance properties. The ∆ parameter that informs about the shape of the flood hydrograph is consequently the flood characteristic duration of the studied basin. The two parameters of the exponential maximum flood distribution for d=0 (a0 and x0) and ∆ were fitted to sample discharges (Vd). This model is called a converging QdF model because of the observed convergence of distributions towards small return periods. This model is also useful for the determination of threshold discharges (Qd). The analytical formulation of the V(d,T) model can be derived according to d, in order to obtain a Q(d,T) model. This model then permits the calculation of the hydrograph for any return period (T) and any duration (d).The regionalization of the sediment yield was achieved within the framework of the Riverlife European project, in collaboration with NIHWM (National Institute of Hydrology and Water Management of Romania). Initially, local models were built. As an example, starting from the Bega sub-basin at Balint, with a surface of 1,064 km2, our intent was to present the transposition of the discharge-duration-frequency analysis concept (or QdF) to the wash load QMES dF. The latter relates to the measurement procedure, the statistical processing of the observed data QMES (t), and to the building of the discharge hydrographs of the associated projects.The main results were:- The statistical analyses of floods and sediment discharges show that the wash loads were not simply proportional to the discharge, but rather they increased more rapidly. The selection of the appropriate distribution laws (Pareto generalised for the QMESdF model (four parameters) and exponential for the QdF model) reinforced this result.- The lag-time was the same for both hydrographs with respect to flood and sediment discharge. This result can be achieved if the sediment transport comes primarily from the scrubbing of the slopes (wash load), which was hypothesised a priori. However, falling limb of the sediment hydrograph decreases more quickly than for the discharge hydrograph (∆MES is lower than ∆).The Bega sub-basin example at Balint was a first test towards the regional modelling of the contributions to sediment discharge in the catchment area of Timis-BĂ©ga. This flood and sediment discharge regionalization is necessary for the study of the protection of the town of Timisoara against flooding

    ModĂ©lisation statistique des apports de MES associĂ©s au rĂ©gime des crues d’un sous- bassin du Timis-BĂ©ga (Roumanie)

    Get PDF
    Dans cette thĂ©matique concernant le transport solide des cours d’eau, il nous semble opportun de rĂ©sumer le cadre gĂ©nĂ©ral et d’y situer notre approche. Les formules classiques du transport solide Ă©valuent le dĂ©bit en matĂ©riaux du lit (charriage et suspension) Ă  partir de ses dĂ©formations. Elles ne permettent pas d’estimer le dĂ©bit des matĂ©riaux provenant directement du lessivage des versants et qui transite sans interaction avec le lit. Dans cet article, nous considĂ©rons uniquement la phase en suspension "MES" mesurĂ©e sans distinction Ă  priori de l’origine des grains qui la constitue : provenance directe du bassin versant (phase directe) et (ou) reprise des stocks disponibles dans le lit (phase diffĂ©rĂ©e). Le bassin hydrographique du Timis-BĂ©ga (Roumanie) est particuliĂšrement bien Ă©quipĂ© pour le suivi des dĂ©bits de 28 sous bassins et le contrĂŽle des flux de MES de douze d’entre eux. De plus, son contexte physiographique nous permet de penser que la phase directe est prĂ©pondĂ©rante. Le protocole de mesure des flux de MES prĂ©voit, entre autres, une densification variable des observations selon l’intensitĂ© des crues liquides. Ces considĂ©rations prĂ©cĂ©dentes nous permettent d’envisager une modĂ©lisation statistique des apports solides en MES des sous-bassins du Timis-BĂ©ga. Celle-ci est directement inspirĂ©e des connaissances acquises sur la modĂ©lisation statistique "QdF" des rĂ©gimes hydrologiques des bassins versants. Sur l’exemple du sous-bassin du BĂ©ga Ă  Balint, qui draine une superficie de 1064 km2, nous retiendrons deux principaux rĂ©sultats issus de la transposition du concept QdF aux dĂ©bits solides QMESdF : Les analyses statistiques des rĂ©gimes liquide et solide montrent que les dĂ©bits solides de MES ne sont pas simplement proportionnels aux dĂ©bits liquides mais croissent plus rapidement. Les deux lois de distributions privilĂ©giĂ©es, Pareto gĂ©nĂ©ralisĂ©e pour les MES et exponentielle pour les dĂ©bits, permettent de le justifier. Le temps de montĂ©e des hydrogrammes de projet liquide ou solide est quasiment identique, autrement dit nous vĂ©rifions la quasi concomitance de leurs dĂ©bits de pointe. Ce rĂ©sultat n’est possible que si le dĂ©bit solide de MES provient essentiellement du lessivage des versants, ce qui Ă©tait supposĂ© Ă  priori.With respect to sediment transport, we detailed the general framework and how our approach contributes to these developments. Starting from the single traditional relation for the bed material load, specialists in river hydraulics cannot assess sediment yield of basins, when it involves the auto-suspension of fine sediments coming mainly from slope erosion (wash load). This latter estimate is needed for simulating the transfer of sediments and possible deposition in certain areas, particularly when a strong slowing down occurs. The Timis-Bega drainage basin (Romania) is fairly well equipped for the monitoring of discharge and suspended materials (sediment discharge). The hydrometric network includes 28 stations, of which 12 allow a monitoring of wash load. Moreover, its physiographic characteristics led us to think that the wash load dominates. Thus we assumed that sediment discharge was correlated with the physiographic features of the catchment area. The protocol for the measurement of the suspended sediment load was intensified during the floods. Thus, statistical modelling of the sub-basin sediment yields could be performed.The current study was directly inspired by the knowledge obtained in the domain of statistical modelling that describes hydrological regimes. The approach adopted was based on the flood-duration-frequency (QdF) analysis that takes into account the temporal variability of floods. The QdF approach analyses maximum average flows (Vd) over various durations (d), equivalent to intensity-duration-frequency (IdF) curves commonly used for rainfall analysis. The proposed model allows QdF curves V(d, T) for a given basin to be estimated using a minimum number of parameters. When the statistical law is the exponential law, this model contains only three parameters, due to observed scale invariance properties. The ∆ parameter that informs about the shape of the flood hydrograph is consequently the flood characteristic duration of the studied basin. The two parameters of the exponential maximum flood distribution for d=0 (a0 and x0) and ∆ were fitted to sample discharges (Vd). This model is called a converging QdF model because of the observed convergence of distributions towards small return periods. This model is also useful for the determination of threshold discharges (Qd). The analytical formulation of the V(d,T) model can be derived according to d, in order to obtain a Q(d,T) model. This model then permits the calculation of the hydrograph for any return period (T) and any duration (d).The regionalization of the sediment yield was achieved within the framework of the Riverlife European project, in collaboration with NIHWM (National Institute of Hydrology and Water Management of Romania). Initially, local models were built. As an example, starting from the Bega sub-basin at Balint, with a surface of 1,064 km2, our intent was to present the transposition of the discharge-duration-frequency analysis concept (or QdF) to the wash load QMES dF. The latter relates to the measurement procedure, the statistical processing of the observed data QMES (t), and to the building of the discharge hydrographs of the associated projects.The main results were:- The statistical analyses of floods and sediment discharges show that the wash loads were not simply proportional to the discharge, but rather they increased more rapidly. The selection of the appropriate distribution laws (Pareto generalised for the QMESdF model (four parameters) and exponential for the QdF model) reinforced this result.- The lag-time was the same for both hydrographs with respect to flood and sediment discharge. This result can be achieved if the sediment transport comes primarily from the scrubbing of the slopes (wash load), which was hypothesised a priori. However, falling limb of the sediment hydrograph decreases more quickly than for the discharge hydrograph (∆MES is lower than ∆).The Bega sub-basin example at Balint was a first test towards the regional modelling of the contributions to sediment discharge in the catchment area of Timis-BĂ©ga. This flood and sediment discharge regionalization is necessary for the study of the protection of the town of Timisoara against flooding

    Androgen Receptor-Target Genes in African American Prostate Cancer Disparities

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    The incidence and mortality rates of prostate cancer (PCa) are higher in African American (AA) compared to Caucasian American (CA) men. To elucidate the molecular mechanisms underlying PCa disparities, we employed an integrative approach combining gene expression profiling and pathway and promoter analyses to investigate differential transcriptomes and deregulated signaling pathways in AA versus CA cancers. A comparison of AA and CA PCa specimens identified 1,188 differentially expressed genes. Interestingly, these transcriptional differences were overrepresented in signaling pathways that converged on the androgen receptor (AR), suggesting that the AR may be a unifying oncogenic theme in AA PCa. Gene promoter analysis revealed that 382 out of 1,188 genes contained cis-acting AR-binding sequences. Chromatin immunoprecipitation confirmed STAT1, RHOA, ITGB5, MAPKAPK2, CSNK2A,1 and PIK3CB genes as novel AR targets in PCa disparities. Moreover, functional screens revealed that androgen-stimulated AR binding and upregulation of RHOA, ITGB5, and PIK3CB genes were associated with increased invasive activity of AA PCa cells, as siRNA-mediated knockdown of each gene caused a loss of androgen-stimulated invasion. In summation, our findings demonstrate that transcriptional changes have preferentially occurred in multiple signaling pathways converging (“transcriptional convergence”) on AR signaling, thereby contributing to AR-target gene activation and PCa aggressiveness in AAs

    Social group membership before treatment for substance dependence predicts early identification and engagement with treatment communities

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    Social relationships play a major role in recovery from substance dependence. To date, greater attention has been paid to the role of important individuals in a person’s life and their contribution to recovery following treatment. This study is the first to examine both individual and wider group-based social connections in the lead up to residential treatment for substance misuse in a therapeutic community (TC), and their influence both on a person’s readiness to engage with the treatment community and with a recovery pathway. Participants were 307 adults interviewed early in treatment about their individual- and group-based social relationships prior to treatment entry, their social identification with the TC, as ‘a user’ and a person ‘in recovery’, their current recovery capital and quality of life. Correlational analysis showed that only pre-treatment group-based, and not individual, relationships, were significantly associated with developing social identification with the TC early in treatment. Moreover, results of hierarchical regression analyses indicated that identification with the TC was best predicted by the extent to which people saw themselves as being in recovery. Finally, mediation analysis indicated that TC identification was the mechanism through which social group memberships prior to treatment commencement protected quality of life in the early phases of treatment. These findings highlight the protective role that group memberships play in building early identification with the TC and supporting well-being in a critical period of transitioning to treatment

    Tablets at the bedside - iPad-based visual field test used in the diagnosis of Intrasellar Haemangiopericytoma: a case report

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    BACKGROUND: In the assessment of a pituitary mass, objective visual field testing represents a valuable means of evaluating mass effect, and thus in deciding whether surgical management is warranted. CASE PRESENTATION: In this vignette, we describe a 73 year-old lady who presented with a three-week history of frontal headache, and 'blurriness' in the left side of her vision, due to a WHO grade III anaplastic haemangiopericytoma compressing the optic chiasm. We report how timely investigations, including an iPad-based visual field test (Melbourne Rapid Field, (MRF)) conducted at the bedside aided swift and appropriate management of the patient. CONCLUSIONS: We envisage such a test having a role in assessing bed-bound patients in hospital where access to formal visual field testing is difficult, or indeed in rapid testing of visual fields at the bedside to screen for post-operative complications, such as haematoma

    Incidence of Primary End Point Changes Among Active Cancer Phase 3 Randomized Clinical Trials

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    IMPORTANCE: Primary end point (PEP) changes to an active clinical trial raise questions regarding trial quality and the risk of outcome reporting bias. It is unknown how the frequency and transparency of the reported changes depend on reporting method and whether the PEP changes are associated with trial positivity (ie, the trial met the prespecified statistical threshold for PEP positivity). OBJECTIVES: To assess the frequency of reported PEP changes in oncology randomized clinical trials (RCTs) and whether these changes are associated with trial positivity. DESIGN, SETTING, AND PARTICIPANTS: This cross-sectional study used publicly available data for complete oncology phase 3 RCTs registered in ClinicalTrials.gov from inception through February 2020. MAIN OUTCOMES AND MEASURES: The main outcome was change between the initial PEP and the final reported PEP, assessed using 3 methods: (1) history of tracked changes on ClinicalTrials.gov, (2) self-reported changes noted in the article, and (3) changes reported within the protocol, including all available protocol documents. Logistic regression analyses were performed to evaluate whether PEP changes were associated with US Food and Drug Administration approval or trial positivity. RESULTS: Of 755 included trials, 145 (19.2%) had PEP changes found by at least 1 of the 3 detection methods. Of the 145 trials with PEP changes, 102 (70.3%) did not have PEP changes disclosed within the manuscript. There was significant variability in rates of PEP detection by each method (χ2 = 72.1; P \u3c .001). Across all methods, PEP changes were detected at higher rates when multiple versions of the protocol (47 of 148 [31.8%]) were available compared with 1 version (22 of 134 [16.4%]) or no protocol (76 of 473 [16.1%]) (χ2 = 18.7; P \u3c .001). Multivariable analysis demonstrated that PEP changes were associated with trial positivity (odds ratio, 1.86; 95% CI, 1.25-2.82; P = .003). CONCLUSIONS AND RELEVANCE: This cross-sectional study revealed substantial rates of PEP changes among active RCTs; PEP changes were markedly underreported in published articles and mostly occurred after reported study completion dates. Significant discrepancies in the rate of detected PEP changes call into question the role of increased protocol transparency and completeness in identifying key changes occurring in active trials

    Hypothermic cardiac arrest far away from the center providing rewarming with extracorporeal circulation

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    A 41-year-old man suffered hypothermic cardiac arrest after water immersion and was transported to our university hospital by ambulance helicopter for rewarming on cardiopulmonary bypass. He resumed spontaneous cardiac activity 6 h 52 min after cardiac arrest and recovered completely

    Microscopic origin of Cooper pairing in the iron-based superconductor Ba₁₋ₓKₓFe₂As₂

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    Resolving the microscopic pairing mechanism and its experimental identification in unconventional superconductors is among the most vexing problems of contemporary condensed matter physics. We show that Raman spectroscopy provides an avenue towards this aim by probing the structure of the pairing interaction at play in an unconventional superconductor. As we study the spectra of the prototypical Fe-based superconductor Ba1−xKxFe2As2 for 0.22 ≀ x ≀ 0.70 in all symmetry channels, Raman spectroscopy allows us to distill the leading s-wave state. In addition, the spectra collected in the B1g symmetry channel reveal the existence of two collective modes which are indicative of the presence of two competing, yet sub-dominant, pairing tendencies of dx2−y2 symmetry type. A comprehensive functional Renormalization Group and random-phase approximation study on this compound confirms the presence of the two sub-leading channels, and consistently matches the experimental doping dependence of the related modes. The consistency between the experimental observations and the theoretical modeling suggests that spin fluctuations play a significant role in superconducting pairing
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