205 research outputs found
Concept of dealing with uncertainty in radar-based data for hydrological purpose
International audiencePrecipitation radar-based data constitute essential input to Numerical Weather Prediction (NWP) and rainfall-runoff models, however the data introduce a number of errors. Thus their uncertainty should be determined to provide end-users with more reliable information about forecasts. The common idea is to use Quality Index (QI) scheme for some number of quality parameters on the assumption that: (1) relationship between the parameters and relevant quality indexes is linear; (2) averaged QI is a weighted average of all particular indexes. The uncertainty parameters can be topography-dependent, resulting from spatial and temporal distribution of data, etc. Uncertainty in radar-based data is described by gamma PDF of precipitation, and it is proposed to determine the probability density function (PDF) parameters basing on QI values. Practically, precipitation is presented as ensemble of quantiles of the PDF and such an ensemble can constitute input to rainfall-runoff modelling. Since the ensemble is a precipitation input, the hydrological model needs to be activated according to a number of input members
Relative quantification of CYP1A gene expression in whitefish (Coregonus lavaretus) exposed to benzo[a]pyrene
The expression of CYP1A (cytochrome P4501A) can be induced by a number of aromatic compounds in teleost fishes. We developed a real-time PCR assay for measuring relative quantities (RQ) of CYP1A mRNA in whitefish (Coregonus lavaretus). To test for the usefulness of the assay we performed a treatment study, using benzo[a]pyrene (B[a]P) a model CYP1A inducer. Primers for the CYP1A gene were adapted from the literature, whereas those for [beta]-actin (endogenous control) were designed from a region that was found to be conserved among salmonid [beta]-actin genes. A group of hatchery raised whitefish, with an average body mass of 15 g and total length of 12 cm were given an intraperitoneal injection (10 mg/kg) of B[a]P in corn oil (2 mg B[a]P/ml corn oil) or corn oil alone (Control). After 48 h, whitefish liver, head kidney and brains were collected for mRNA isolation and analysis. In all three tissues sampled, CYP1A mRNA was affected by treatment with B[a]P. Head kidney tissue showed the greatest induction potential (RQ=11.00) from base levels (RQ=1.00), followed by liver (RQ=9.45), and brain (RQ=3.76). These results demonstrated that CYP1A was highly inducible by B[a]P in whitefish head kidney and liver, and to some extent, in brain tissue. The approach presented here has the advantage of providing rapid and accurate measures of CYP1A induction in various tissues of fish responding to PAH contaminant exposure
Long-term multi-source precipitation estimation with high resolution (RainGRS Clim)
This paper explores the possibility of using multi-source
precipitation estimates for climatological applications. A data-processing
algorithm (RainGRS Clim) has been developed to work on precipitation
accumulations such as daily or monthly totals, which are significantly
longer than operational accumulations (generally between 5 min and 1 h). The
algorithm makes the most of additional opportunities, such as the
possibility of complementing data with delayed data, access to high-quality data
that are not operationally available, and the greater efficiency of the
algorithms for data quality control and merging with longer accumulations.
Verification of the developed algorithms was carried out using monthly
accumulations through comparison with precipitation from manual rain gauges.
As a result, monthly accumulations estimated by RainGRS Clim were found to
be significantly more reliable than accumulations generated operationally.
This improvement is particularly noticeable for the winter months, when
precipitation estimation is much more difficult due to less reliable radar
estimates.</p
Educating Health Professionals about Disability: A Review of Interventions
Health professionals need to understand the human rights and health needs of disabled people. This review of evidence on interventions demonstrates that a range of often innovative approaches have been trialled. Lectures by faculty are less effective in changing attitudes than contact with disabled people themselves. Existing examples of good practice need to be scaled up, and better and more long-term evaluations of impact are required
Coordination and organometallic precursors of group 10 and 11 Focused electron beam induced deposition of metals and insight gained from chemical vapour deposition, atomic layer deposition, and fundamental surface and gas phase studies
Nanostructured materials made from group 10 Ni, Pd, Pt and group 11 Cu, Ag, Au elements have outstanding technological relevance in microelectronics, nano optics, catalysis, and energy conversion. Processes that allow for the easy and reliable fabrication of such nanostructures are heavily sought after. Focused electron beam induced deposition FEBID is the only direct write technique that can fabricate nanostructures with arbitrary shape and dimensions down to the sub 10 nm regime. However, the complex chemistry of FEBID involving electron induced dissociation processes of metalorganic precursors molecules, surface kinetics, and thermal effects is poorly understood and far from being optimized. Here, we review in a comparative manner the performance and the underlying chemical reactions of surface deposition processes, namely, chemical vapour deposition CVD , atomic layer deposition ALD , and FEBID itself. The knowledge gained in CVD and ALD as related surface deposition techniques will help us to understand the spatially selective chemistry occurring in FEBID. Fundamental surface and gas phase studies provide insight to electron induced chemistry and desorption of precursor fragments. Specific emphasis is put on the type of the ligands and their different behaviour under thermal, surface related, and electron induced processes. The comprehensive overview of the current state of FEBID for group 10 and 11 metals includes reactive environments and purification approaches as these may provide valuable information on the design of novel precursors. The evaluation of the precursor and process performance is extended to include W, Co, Fe, Ru, Rh, and Ir to represent a general guide towards future developments in FEBID. These may not only rely on the design of novel compounds but also on optimized deposition strategies inspired by ALD and CV
Gas assisted silver deposition with a focused electron beam
Focused electron beam induced deposition FEBID is a flexible direct write method to obtain defined structures with a high lateral resolution. In order to use this technique in application fields like plasmonics, suitable precursors which allow the deposition of desired materials have to be identified. Well known for its plasmonic properties, silver represents an interesting candidate for FEBID. For this purpose the carboxylate complex silver I pentafluoropropionate AgO2CC2F5 was used for the first time in FEBID and resulted in deposits with high silver contents up to 76 at. . As verified by TEM investigations, the deposited material is composed of pure silver crystallites in a carbon matrix. It showed good electrical properties and a strong Raman signal enhancement. Interestingly, silver crystal growth presents a strong dependency on electron dose and precursor refreshment
Towards the third dimension in direct electron beam writing of silver
Carboxylates constitute an extremely promising class of precursor compounds for the electron beam induced deposition of silver. In this work both silver 2,2 dimethylbutyrate and silver pentafluoropropionate were investigated with respect to their dwell time dependent deposition behavior and growth characteristics. While silver 2,2 dimethylbutyrate showed a strong depletion in the center of the impinging electron beam profile hindering any vertical growth, silver pentafluoropropionate indicated a pronounced dependency of the deposit height on the dwell time. Truly three dimensional silver structures could be realized with silver pentafluoropropionate. The pillars displayed a polycrystalline habit with silver contents of more than 50 at. and strong Raman enhancement constituting a promising route towards direct electron beam writing of three dimensional plasmonic device parts from the gas phase
Deficiency in origin licensing proteins impairs cilia formation: implications for the aetiology of meier-gorlin syndrome
Mutations in ORC1, ORC4, ORC6, CDT1, and CDC6, which encode proteins required for DNA replication origin licensing, cause Meier-Gorlin syndrome (MGS), a disorder conferring microcephaly, primordial dwarfism, underdeveloped ears, and skeletal abnormalities. Mutations in ATR, which also functions during replication, can cause Seckel syndrome, a clinically related disorder. These findings suggest that impaired DNA replication could underlie the developmental defects characteristic of these disorders. Here, we show that although origin licensing capacity is impaired in all patient cells with mutations in origin licensing component proteins, this does not correlate with the rate of progression through S phase. Thus, the replicative capacity in MGS patient cells does not correlate with clinical manifestation. However, ORC1-deficient cells from MGS patients and siRNA-mediated depletion of origin licensing proteins also have impaired centrosome and centriole copy number. As a novel and unexpected finding, we show that they also display a striking defect in the rate of formation of primary cilia. We demonstrate that this impacts sonic hedgehog signalling in ORC1-deficient primary fibroblasts. Additionally, reduced growth factor-dependent signaling via primary cilia affects the kinetics of cell cycle progression following cell cycle exit and re-entry, highlighting an unexpected mechanism whereby origin licensing components can influence cell cycle progression. Finally, using a cell-based model, we show that defects in cilia function impair chondroinduction. Our findings raise the possibility that a reduced efficiency in forming cilia could contribute to the clinical features of MGS, particularly the bone development abnormalities, and could provide a new dimension for considering developmental impacts of licensing deficiency
Nuclear factor κB-inducing kinase activation as a mechanism of pancreatic β cell failure in obesity
The nuclear factor κB (NF-κB) pathway is a master regulator of inflammatory processes and is implicated in insulin resistance and pancreatic β cell dysfunction in the metabolic syndrome. Whereas canonical NF-κB signaling is well studied, there is little information on the divergent noncanonical NF-κB pathway in the context of pancreatic islet dysfunction. Here, we demonstrate that pharmacological activation of the noncanonical NF-κB-inducing kinase (NIK) disrupts glucose homeostasis in zebrafish in vivo. We identify NIK as a critical negative regulator of β cell function, as pharmacological NIK activation results in impaired glucose-stimulated insulin secretion in mouse and human islets. NIK levels are elevated in pancreatic islets isolated from diet-induced obese (DIO) mice, which exhibit increased processing of noncanonical NF-κB components p100 to p52, and accumulation of RelB. TNF and receptor activator of NF-κB ligand (RANKL), two ligands associated with diabetes, induce NIK in islets. Mice with constitutive β cell-intrinsic NIK activation present impaired insulin secretion with DIO. NIK activation triggers the noncanonical NF-κB transcriptional network to induce genes identified in human type 2 diabetes genome-wide association studies linked to β cell failure. These studies reveal that NIK contributes a central mechanism for β cell failure in diet-induced obesity
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