135 research outputs found

    Daytime sensible heat flux estimation over heterogeneous surfaces using multitemporal land‐surface temperature observations

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    Equations based on surface renewal (SR) analysis to estimate the sensible heat flux (H) require as input the mean ramp amplitude and period observed in the ramp‐like pattern of the air temperature measured at high frequency. A SR‐based method to estimate sensible heat flux (HSR‐LST) requiring only low‐frequency measurements of the air temperature, horizontal mean wind speed, and land‐surface temperature as input was derived and tested under unstable conditions over a heterogeneous canopy (olive grove). HSR‐LST assumes that the mean ramp amplitude can be inferred from the difference between land‐surface temperature and mean air temperature through a linear relationship and that the ramp frequency is related to a wind shear scale characteristic of the canopy flow. The land‐surface temperature was retrieved by integrating in situ sensing measures of thermal infrared energy emitted by the surface. The performance of HSR‐LST was analyzed against flux tower measurements collected at two heights (close to and well above the canopy top). Crucial parameters involved in HSR‐LST, which define the above mentioned linear relationship, were explained using the canopy height and the land surface temperature observed at sunrise and sunset. Although the olive grove can behave as either an isothermal or anisothermal surface, HSR‐LST performed close to H measured using the eddy covariance and the Bowen ratio energy balance methods. Root mean square differences between HSR‐LST and measured H were of about 55 W m−2. Thus, by using multitemporal thermal acquisitions, HSR‐LST appears to bypass inconsistency between land surface temperature and the mean aerodynamic temperature. The one‐source bulk transfer formulation for estimating H performed reliable after calibration against the eddy covariance method. After calibration, the latter performed similar to the proposed SR‐LST method.This research was funded by project CGL2012‐37416‐C04‐01 and CGL2015‐65627‐C3‐1‐R (Ministerio de Ciencia y Innovación of Spain), CEI Iberus, 2014 (Proyecto financiado por el Ministerio de Educación en el marco del Programa Campus de Excelencia Internacional of Spain), and Ayuda para estancias en centros extranjeros (Ministerio de Educación, Cultura y Deporte of Spain)

    Combining the bulk transfer formulation and surface renewal analysis for estimating the sensible heat flux without involving the parameter KB-1

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    The single‐source bulk transfer formulation (based on the Monin‐Obukhov Similarity Theory, MOST) has been used to estimate the sensible heat flux, H, in the framework of remote sensing over homogeneous surfaces (HMOST). The latter involves the canopy parameter, , which is difficult to parameterize. Over short and dense grass at a site influenced by regional advection of sensible heat flux, HMOST with  = 2 (i.e., the value recommended) correlated strongly with the H measured using the Eddy Covariance, EC, method, HEC. However, it overestimated HEC by 50% under stable conditions for samples showing a local air temperature gradient larger than the measurement error, 0.4 km−1. Combining MOST and Surface Renewal analysis, three methods of estimating H that avoid dependency have been derived. These new expressions explain the variability of H versus , where is the friction velocity, is the radiometric surface temperature, and is the air temperature at height, z. At two measurement heights, the three methods performed excellently. One of the methods developed required the same readily/commonly available inputs as HMOST due to the fact that the ratio between and the ramp amplitude was found fairly constant under stable and unstable cases. Over homogeneous canopies, at a site influenced by regional advection of sensible heat flux, the methods proposed are an alternative to the traditional bulk transfer method because they are reliable, exempt of calibration against the EC method, and are comparable or identical in cost of application. It is suggested that the methodology may be useful over bare soil and sparse vegetation.This research was funded by CERESS project AGL2011–30498 (Ministerio de Economía y Competitividad of Spain, cofunded FEDER), CGL2012–37416‐C04‐01 (Ministerio de Ciencia y Innovación of Spain), and CEI Iberus, 2014 (Proyecto financiado por el Ministerio de Educación en el marco del Programa Campus de Excelencia Internacional of Spain)

    La immigraciĂł francesa a Catalunya: el cas del Baix Llobregat (segles XVI i XVII)

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    Heus aquĂ­ un treball d'abast comarcal sobre la presencia francesa al Baix Llobregat en epoca deis Austria (des de 1563 -obligatorietat manifesta d'enregistrar les actes d'esposalles pel Concili de Trento- fins a 1700 -any de la defunciĂł de Carles II-). A partir de l' analisi i el buidatge deIs llibres de noces de les parroquies, s'han pogut quantificar i recollir estadĂ­sticament les dades de la immigraciĂł ultrapirinenca. Es presenten, mitjan~ant aquests resultats, el percentatge de marits francesos, respecte al total de casaments enregistrats; la tipologia deis matrimonis; la procedencia deis conjuges; i la seva activitat socio-laboral

    Update on genetic predisposition to colorectal cancer and polyposis

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    The present article summarizes recent developments in the characterization of genetic predisposition to colorectal cancer (CRC). The main themes covered include new hereditary CRC and polyposis syndromes, non-CRC hereditary cancer genes found mutated in CRC patients, strategies used to identify novel causal genes, and review of candidate genes that have been proposed to predispose to CRC and/or colonic polyposis. We provide an overview of newly described genes and syndromes associated with predisposition to CRC and polyposis, including: polymerase proofreading-associated polyposis, NTHL1-associated polyposis, mismatch repair gene biallelic inactivation-related adenomatous polyposis (including MSH3- and MLH3-associated polyposes), GREM1-associated mixed polyposis, RNF43-associated serrated polyposis, and RPS20 mutations as a rare cause of hereditary nonpolyposis CRC. The implementation of next generation sequencing approaches for genetic testing has exposed the presence of pathogenic germline variants in genes associated with hereditary cancer syndromes not traditionally linked to CRC, which may have an impact on genetic testing, counseling and surveillance. The identification of new hereditary CRC and polyposis genes has not deemed an easy endeavor, even though known CRC-related genes explain a small proportion of the estimated familial risk. Whole-genome sequencing may offer a technology for increasing this proportion, particularly if applied on pedigree data allowing linkage type of analysis. The final section critically surveys the large number of candidate genes that have been recently proposed for CRC predisposition

    A replication study confirms the association of TNFSF4 (OX40L) polymorphisms with systemic sclerosis in a large European cohort

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    <p><b>Objectives</b> The aim of this study was to confirm the influence of TNFSF4 polymorphisms on systemic sclerosis (SSc) susceptibility and phenotypic features.</p> <p><b>Methods</b> A total of 8 European populations of Caucasian ancestry were included, comprising 3014 patients with SSc and 3125 healthy controls. Four genetic variants of TNFSF4 gene promoter (rs1234314, rs844644, rs844648 and rs12039904) were selected as genetic markers.</p> <p><b>Results</b> A pooled analysis revealed the association of rs1234314 and rs12039904 polymorphisms with SSc (OR 1.15, 95% CI 1.02 to 1.31; OR 1.18, 95% CI 1.08 to 1.29, respectively). Significant association of the four tested variants with patients with limited cutaneous SSc (lcSSc) was revealed (rs1234314 OR 1.22, 95% CI 1.07 to 1.38; rs844644 OR 0.91, 95% CI 0.83 to 0.99; rs844648 OR 1.10, 95% CI 1.01 to 1.20 and rs12039904 OR 1.20, 95% CI 1.09 to 1.33). Association of rs1234314, rs844648 and rs12039904 minor alleles with patients positive for anti-centromere antibodies (ACA) remained significant (OR 1.23, 95% CI 1.10 to 1.37; OR 1.12, 95% CI 1.01 to 1.25; OR 1.22, 95% CI 1.07 to 1.38, respectively). Haplotype analysis confirmed a protective haplotype associated with SSc, lcSSc and ACA positive subgroups (OR 0.88, 95% CI 0.82 to 0.96; OR 0.88, 95% CI 0.80 to 0.96; OR 0.86, 95% CI 0.77 to 0.97, respectively) and revealed a new risk haplotype associated with the same groups of patients (OR 1.14, 95% CI 1.03 to 1.26; OR 1.20, 95% CI 1.08 to 1.35; OR 1.23, 95% CI 1.07 to 1.42, respectively).</p> <p><b>Conclusions</b> The data confirm the influence of TNFSF4 polymorphisms in SSc genetic susceptibility, especially in subsets of patients positive for lcSSc and ACA.</p&gt

    Exome sequencing of early-onset patients supports genetic heterogeneity in colorectal cancer

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    Colorectal cancer (CRC) is a complex disease that can be caused by a spectrum of genetic variants ranging from low to high penetrance changes, that interact with the environment to determine which individuals will develop the disease. In this study, we sequenced 20 early-onset CRC patients to discover novel genetic variants that could be linked to the prompt disease development. Eight genes, CHAD, CHD1L, ERCC6, IGTB7, PTPN13, SPATA20, TDG and TGS1, were selected and re-sequenced in a further 304 early onset CRC patients to search for rare, high-impact variants. Although we found a recurring truncating variant in the TDG gene shared by two independent patients, the results obtained did not help consolidate any of the candidates as promising CRC predisposing genes. However, we found that potential risk alleles in our extended list of candidate variants have a tendency to appear at higher numbers in younger cases. This supports the idea that CRC onset may be oligogenic in nature and may show molecular heterogeneity. Further, larger and robust studies are thus needed to unravel the genetics behind early-onset CRC development, coupled with novel functional analyses and omic approaches that may offer complementary insight

    Modeling Respiratory Depression Induced by Remifentanil and Propofol during Sedation and Analgesia Using a Continuous Noninvasive Measurement of pCO 2 s

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    ABSTRACT Respiratory depression is a common adverse effect of propofol and remifentanil. We aimed to develop a model for respiratory depressant effects of propofol with remifentanil in patients undergoing endoscopy with sedation. Data were available for 136 patients undergoing endoscopy with sedation. Participants randomly received infusions of propofol and remifentanil. Predicted plasma concentrations, outputted by infusion pumps, were available. Transcutaneous arterial pressure of carbon dioxide (pCO 2 ) was measured. Data were analyzed using nonlinear mixed-effects modeling methods. Covariate relationships were investigated for age, noxious stimuli (endoscopy tube insertion), and A118G genotype for the m-opioid receptor (OPRM1). Participants had a median 21 . Propofol affected the modulator compartment with an IC 50 of 4.97 mg/ml (no effect-site compartment). Propofol IC 50 and remifentanil k e0 were reduced with increasing age. Noxious stimuli and genotype were not significant covariates. An indirect-effect model with a rebound mechanism can describe remifentanil-and propofolinduced changes in pCO 2 in patients undergoing noxious procedures. The model may be useful for identifying optimal dosing schedules for these drugs in a combination that provides adequate sedation but avoids respiratory depression
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