1,191 research outputs found

    NCAA v. Board of Regents of the University of Oklahoma: Has the Supreme Court Abrogated the Per Se Rule of Antitrust Analysis

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    Lessons in learning gain: insights from a pilot project

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    ‘Learning gain’ has become an increasingly prominent concept in debates about the effectiveness of higher education across OECD countries. In England, interest has been heightened by the Higher Education Funding Council for England (HEFCE)’s major research initiative on learning gain, launched in 2015, and by the new Teaching Excellence Framework which assesses learning and teaching and student outcomes. HEFCE’s novel research initiative has funded a set of experimental projects across the English higher education sector for the first time. This paper presents preliminary findings from one such project at the University of East Anglia (UEA). The project trials and evaluates three approaches to identifying and measuring learning gain using data from cohorts of students across different discipline areas during 2015–2016 and 2016–2017. It builds upon previous work carried out at UEA in developing self-efficacy assessments and applying concept inventories. Student marks provide a simple comparator as a third approach to measuring learning gain

    Array-based comparative genomic hybridization analysis reveals chromosomal copy number aberrations associated with clinical outcome in canine diffuse large B-cell lymphoma

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    Canine Diffuse Large B-cell Lymphoma (cDLBCL) is an aggressive cancer with variable clinical response. Despite recent attempts by gene expression profiling to identify the dog as a potential animal model for human DLBCL, this tumor remains biologically heterogeneous with no prognostic biomarkers to predict prognosis. The aim of this work was to identify copy number aberrations (CNAs) by high-resolution array comparative genomic hybridization (aCGH) in 12 dogs with newly diagnosed DLBCL. In a subset of these dogs, the genetic profiles at the end of therapy and at relapse were also assessed. In primary DLBCLs, 90 different genomic imbalances were counted, consisting of 46 gains and 44 losses. Two gains in chr13 were significantly correlated with clinical stage. In addition, specific regions of gains and losses were significantly associated to duration of remission. In primary DLBCLs, individual variability was found, however 14 recurrent CNAs (>30%) were identified. Losses involving IGK, IGL and IGH were always found, and gains along the length of chr13 and chr31 were often observed (>41%). In these segments, MYC, LDHB, HSF1, KIT and PDGFR alpha are annotated. At the end of therapy, dogs in remission showed four new CNAs, whereas three new CNAs were observed in dogs at relapse compared with the previous profiles. One ex novo CNA, involving TCR, was present in dogs in remission after therapy, possibly induced by the autologous vaccine. Overall, aCGH identified small CNAs associated with outcome, which, along with future expression studies, may reveal target genes relevant to cDLBCL

    A single amino acid change A19V in perforin: a novel, frequent predisposing factor to childhood acute lymphoblastic leukemia?

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    We screened 100 children with acute lymphoblastic leukemia (ALL) to assess the incidence of single amino acid change A91V in perform. Heterozygous A91V was found in 12/100 patients and 5/127 controls (OR, 3.4; 95%CI: 1.15-9.95; p=0.014). A91V is a novel and frequent predisposing factor for childhood ALL

    Trace elements release from volcanic ashes to seawater. Natural concentrations in Central Mediterranean sea.

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    Distributions and concentrations of many minor and trace elements in epicontinental basins, as Mediterranean Sea, are mainly driven to atmospheric fallout from surroundings. This mechanism supplies an estimated yearly flux of about 1000 kg km-2 of terrigenous matter of different nature on the whole Mediterranean basin. Dissolution of these materials and processes occurring at solid-liquid interface along the water column drive the distributions of many trace elements as V, Cr, Mn, Co, Cu, and Pb with contents ranging from pmol l-1 (Co, Cd, Pb) to nmol l-1 scale in Mediterranean seawater, with some local differences in the basin. The unwinding of an oceanographic cruise in the coastal waters of Ionian Sea during the Etna’s eruptive activity in summer 2001 led to the almost unique chance to test the effects of large delivery of volcanic ash to a coastal sea water system through the analyses of distribution of selected trace elements along several seawater columns. The collection of these waters and their analyses about V, Cr, Mn, Co, Cu, and Pb contents evidenced trace element concentrations were always higher (about 1 order of magnitude at least) than those measured concentrations in the recent past in Mediterranean seawater, apart from Pb. Progressive increase of concentrations of some elements with depth, sometimes changing in a “conservative” behaviour without any clear reason and the observed higher concentrations required an investigation about interaction processes occurring at solid-liquid interface between volcanic ash and seawater along water columns. This investigation involving kinetic evaluation of trace element leaching to seawater, was carried out during a 6 months time period under laboratory conditions. X-ray investigations, SEM-EDS observations and analyses on freshly-erupted volcanic ash evidenced formation of alteration clay minerals onto glass fraction surfaces. Chemical analyses carried out on coexisting liquid phase demonstrated that trace element leaching occurs through a first quick followed by a slow second step that attaints to an apparent equilibrium after 6 months. Amplitude of kinetic rate constant measured for SiO2 release during the first step and behaviour of Ti/Si and Cr/Si rations in primary volcanic minerals, glass fraction and leaching solutions during the first 1 month stage of the experimental interaction allowed to demonstrate that trace element release mainly occurs from glassy materials and Ti-rich magnetite

    Durable superhydrophobic and antireflective surfaces by trimethylsilanized silica nanoparticles-based sol-gel processing.

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    We present a robust and cost-effective coating method to fabricate long-term durable superhydrophobic, and-simultaneously-antireflective surfaces by a double-layer coating comprising trimethylsiloxane (TMS) surface-functionalized silica nanoparticles partially embedded into an organosilica binder matrix produced through a sol-gel process. A dense and homogeneous organosilica gel layer was First coated onto a glass substrate, and then, a trimethylsilanized nanospheres-based superhydrophobic layer was deposited onto it. After thermal curing, the two layers turned into a monolithic film, and the hydrophobic nanoparticles were permanently fixed to the glass substrate. Such treated surfaces showed a tremendous water repellency (contact angle = 168 degrees) and stable self-cleaning effect during 2000 h of outdoor exposure. Besides this, nanotextured topology generated by the self-assembled nanoparticles-based top layer produced a fair antireflection effect consisting of more than a 3% increase in optical transmittance

    Phosgene-free carbamoylation of aniline via dimethyl carbonate

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    The synthesis of N-phenylcarbamate from aniline and dimethyl carbonate (DMC) in the presence of homogeneous, supported heterogeneous, and heterogeneous catalysts was investigated in batch conditions. First, a selection of homogeneous catalysts was studied and their reactivity in the same reaction conditions was compared to zinc acetate, a catalyst extensively used for this reaction. Then the best homogeneous catalysts were supported on silica or alumina, and the resulting heterogeneous supported catalysts were tested for the carbamoylation of aniline. Finally, several heterogeneous catalysts were investigated. Zinc carbonate basic was shown to be the best catalyst, giving quantitative conversion and selectivity for the N-phenylcarbamate. Its catalytic activity was fully investigated taking into account substrate concentration, amount of catalysts, and temperature influence. Zinc carbonate was also shown to be recyclable, once it was recovered from the reaction mixture and calcinated

    Epigenetic silencing of TFPI-2 in canine diffuse large B-cell lymphoma

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    Epigenetic modifications are important early events during carcinogenesis. In particular, hypermethylation of CpG islands in the promoter region of tumor suppressor genes is a well-known mechanism of gene silencing that contributes to cancer development and progression. Tissue factor pathway inhibitor 2 (TFPI-2) is a tumor suppressor involved in invasiveness inhibition. Although TFPI-2 transcriptional silencing, through promoter hypermethylation, has been widely reported in several human malignancies, it has never been explored in lymphoma. In the present study TFPI-2 methylation and gene expression have been investigated in canine Diffuse Large B-cell lymphomas (cDLBCL). The methylation level of 23 CpGs located within the TFPI-2 promoter was investigated by bisulfite-specific PCR and next generation amplicon deep sequencing (GS Junior 454, Roche) in 22 cDLBCLs and 9 controls. For the same specimens, TFPI-2 gene expression was assessed by means of Real-time RT-PCR. Sequence analysis clearly demonstrated that TFPI2 is frequently hypermethylated in cDLBCL. Hypermethylation of the TFPI-2 promoter was found in 77% of DLBCLs ( 17 out of 22) and in one normal lymph node. Globally, dogs with DLBCL showed a mean methylation level significantly increased compared to controls (p<0.01) and analysis of hypermethylation by site identified 19 loci out of 23 ( 82%) with mean methylation levels from 2- to 120-fold higher in cDLBCL. Gene expression analysis confirmed a significant down-regulation of TFPI-2 ( p<0.05) in DLBCLs compared with normal lymph nodes, suggesting that TFPI-2 hypermethylation negatively regulates its transcription. In addition, a significant positive correlation ( p<0.01) was found between TFPI-2 methylation levels and age providing the first indication of age-associated epigenetic modifications in canine DLBCL. To conclude, our findings demonstrated that epigenetic dysregulation of TFPI-2, leading to its reduced expression, is frequently detected in canine DLBCL. In the next future, the aberrant TFPI-2 promoter hypermethylation may be considered in association with prognosis and therapy

    Synthesis of dialkyl ethers by decarboxylation of dialkyl carbonates

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    The decarboxylation reaction of dialkyl carbonates to give their related ethers was investigated. The reaction was carried out at atmospheric pressure and in the presence of hydrotalcite or basic alumina as catalysts without any solvent. The influence of several reaction parameters on the selectivity was studied (e.g. temperature, amount of catalyst, substrate concentration, solvent). The stability of the catalyst was also investigated. The experimental data for the decarboxylation confirmed that this reaction is complicated by competitive processes, such as dismutation and, in one case, pyrolysis. The results obtained show that in the presence of hydrotalcite as a catalyst, symmetrical dialkyl ethers can be synthesised with yields up to 80%. Dissymmetrical ethers (i.e. methyl alkyl ethers) can be produced with yields up to 80% at high temperature (250 ◦C). The catalyst proved to be fully recyclable in all cases studied, except for the carbonate containing n-octyl moiety
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