112 research outputs found

    Value-added measures in Italian high schools: problems and findings

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    Students’ competencies are influenced by a host of factors, including the individual school’s effectiveness. Measuring this contribution is extremely difficult. One way of circumventing the problem is by focusing on changes in competencies over time, i.e. value-added measures. Using the results of an INVALSI survey of high schools, this paper implements these measures for Italy, in an attempt to identify a general pattern of value-added among schools. Purging the sample of measurement errors – which require the exclusion of schools with too few students tested – and taking into account the selection bias implied by the non-compulsory nature of schools’ participation in the survey, we find that the positive gap in favour of general programs (licei) when looking at the level of competencies tends to vanish (in maths and science) when focusing on value-added measures. By contrast, in the maths and science field schools located in the Southern regions are characterized not only by a lower starting level of competencies but also by a lower value-added. For maths at least, there is also a general tendency for teachers’ turnover to have a negative effect on student improvements.education, value-added

    Reanalysis of updated mortality among vinyl and polyvinyl chloride workers: Confirmation of historical evidence and new findings

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    <p>Abstract</p> <p>Background</p> <p>The production of vinyl chloride (VC) and polyvinyl chloride (PVC) involves the use of various chemicals, some known to be toxic and potentially or definitely carcinogenic. The related potential risk often has not been properly investigated. Updated cancer mortality among different subgroups of workers employed in a VC-PVC production plant located in Porto Marghera (Italy) was re-analyzed using an internal reference group of workers with low (or null) exposure to VC.</p> <p>Methods</p> <p>Mortality of 1658 male workers was analyzed by Poisson regression. Relative risks (RRs) and 95% confidence intervals (CIs) for blue collar workers and their specific subgroups of PVC baggers, PVC compound, autoclave and other blue collar workers were calculated using technicians and clerks as an internal reference group. The follow-up covered the period 1972–1999.</p> <p>Results</p> <p>Significantly increased mortality rates were observed for all causes of death among the whole blue collar workforce (RR = 1.55; 95% CI = 1.03–2.35; 229 deaths), PVC baggers (1.72; 95% CI = 1.04–2.83; 49 deaths) and PVC compound workers (1.71; 95% CI = 1.09–2.67; 72 deaths). Liver cancer, including angiosarcoma, was increased among autoclave workers (9.57; 95% CI = 3.71–24.68; 7 deaths) and cardiovascular diseases among PVC baggers (2.25; 95% CI = 1.08–4.70; 12 deaths). Hemolymphopoietic system tumors, leukemias and lymphomas prevalently, were found only among exposed workers, with 4, 4 and 6 deaths observed among PVC baggers, PVC compound and other blue collar workers, respectively. An excess of lung cancer was found among PVC baggers.</p> <p>Conclusion</p> <p>This cohort analysis, based on internal comparison, confirmed previously reported specific risk excesses for liver tumors and liver cirrhosis among autoclave workers and for lung cancer among PVC baggers, and revealed PVC compound workers as a possible new at risk group for all causes, all tumors and for liver and lung tumors. In conclusion, RRs for all causes of death and all tumors were increased among all blue collar workers.</p

    The nucleolar size is associated to the methylation status of ribosomal DNA in breast carcinomas.

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    BACKGROUND: There is a body of evidence that shows a link between tumorigenesis and ribosome biogenesis. The precursor of mature 18S, 28S and 5.8S ribosomal RNAs is transcribed from the ribosomal DNA gene (rDNA), which exists as 300-400 copies in the human diploid genome. Approximately one half of these copies are epigenetically silenced, but the exact role of epigenetic regulation on ribosome biogenesis is not completely understood. In this study we analyzed the methylation profiles of the rDNA promoter and of the 5' regions of 18S and 28S in breast cancer. METHODS: We analyzed rDNA methylation in 68 breast cancer tissues of which the normal counterpart was partially available (45/68 samples) using the MassARRAY EpiTYPER assay, a sensitive and quantitative method with single base resolution. RESULTS: We found that rDNA locus tended to be hypermethylated in tumor compared to matched normal breast tissues and that the DNA methylation level of several CpG units within the rDNA locus was associated to nuclear grade and to nucleolar size of tumor tissues. In addition we identified a subgroup of samples in which large nucleoli were associated with very limited or absent rDNA hypermethylation in tumor respect to matched normal tissue. CONCLUSIONS: In conclusion, we suggest that rDNA is an important target of epigenetic regulation in breast tumors and that rDNA methylation level is associated to nucleolar size

    Phenolic Compounds of Red Wine \u3ci\u3eAglianico del Vulture\u3c/i\u3e Modulate the Functional Activity of Macrophages via Inhibition of \u3ci\u3eNF-κB\u3c/i\u3e and the Citrate Pathway

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    Phenolic compounds of red wine powder (RWP) extracted from the Italian red wine Aglianico del Vulture have been investigated for the potential immunomodulatory and anti-inflammatory capacity on human macrophages. These compounds reduce the secretion of IL-1β, IL-6, and TNF-α proinflammatory cytokines and increase the release of IL-10 anti-inflammatory cytokine induced by lipopolysaccharide (LPS). In addition, RWP restores Annexin A1 levels, thus involving activation of proresolutive pathways. Noteworthy, RWP lowers NF-κB protein levels, promoter activity, and nuclear translocation. As a consequence of NF-κB inhibition, reduced promoter activities of SLC25A1—encoding the mitochondrial citrate carrier (CIC)—and ATP citrate lyase (ACLY) metabolic genes have been observed. CIC, ACLY, and citrate are components of the citrate pathway: in LPS-activated macrophages, the mitochondrial citrate is exported by CIC into the cytosol where it is cleaved by ACLY in oxaloacetate and acetyl-CoA, precursors for ROS, NO⋅, and PGE2 inflammatory mediators. We identify the citrate pathway as a RWP target in carrying out its anti-inflammatory activity since RWP reduces CIC and ACLY protein levels, ACLY enzymatic activity, the cytosolic citrate concentration, and in turn ROS, NO⋅, PGE2, and histone acetylation levels. Overall findings suggest that RWP potentially restores macrophage homeostasis by suppressing inflammatory pathways and activating proresolutive processes

    ITCH E3 ubiquitin ligase downregulation compromises hepatic degradation of branched-chain amino acids

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    Objective: Metabolic syndrome, obesity, and steatosis are characterized by a range of dysregulations including defects in ubiquitin ligase tagging proteins for degradation. The identification of novel hepatic genes associated with fatty liver disease and metabolic dysregulation may be relevant to unravelling new mechanisms involved in liver disease progression METHODS: Through integrative analysis of liver transcriptomic and metabolomic obtained from obese subjects with steatosis, we identified itchy E ubiquitin protein ligase (ITCH) as a gene downregulated in human hepatic tissue in relation to steatosis grade. Wild-type or ITCH knockout mouse models of non-alcoholic fatty liver disease (NAFLD) and obesity-related hepatocellular carcinoma were analyzed to dissect the causal role of ITCH in steatosis RESULTS: We show that ITCH regulation of branched-chain amino acids (BCAAs) degradation enzymes is impaired in obese women with grade 3 compared with grade 0 steatosis, and that ITCH acts as a gatekeeper whose loss results in elevation of circulating BCAAs associated with hepatic steatosis. When ITCH expression was specifically restored in the liver of ITCH knockout mice, ACADSB mRNA and protein are restored, and BCAA levels are normalized both in liver and plasma CONCLUSIONS: Our data support a novel functional role for ITCH in the hepatic regulation of BCAA metabolism and suggest that targeting ITCH in a liver-specific manner might help delay the progression of metabolic hepatic diseases and insulin resistance

    Adaptive Lévy Walks in Foraging Fallow Deer

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    Background: Lévy flights are random walks, the step lengths of which come from probability distributions with heavy power-law tails, such that clusters of short steps are connected by rare long steps. Lévy walks maximise search efficiency of mobile foragers. Recently, several studies raised some concerns about the reliability of the statistical analysis used in previous analyses. Further, it is unclear whether Lévy walks represent adaptive strategies or emergent properties determined by the interaction between foragers and resource distribution. Thus two fundamental questions still need to be addressed: the presence of Lévy walks in the wild and whether or not they represent a form of adaptive behaviour. Methodology/Principal Findings: We studied 235 paths of solitary and clustered (i.e. foraging in group) fallow deer (Dama dama), exploiting the same pasture. We used maximum likelihood estimation for discriminating between a power-tailed distribution and the exponential alternative and rank/frequency plots to discriminate between Lévy walks and composite Brownian walks. We showed that solitary deer perform Lévy searches, while clustered animals did not adopt that strategy. Conclusion/Significance: Our demonstration of the presence of Lévy walks is, at our knowledge, the first available which adopts up-to-date statistical methodologies in a terrestrial mammal. Comparing solitary and clustered deer, we concluded that the Lévy walks of solitary deer represent an adaptation maximising encounter rates with forage resources and not a

    Metastatic group 3 medulloblastoma is driven by PRUNE1 targeting NME1-TGF-β-OTX2-SNAIL via PTEN inhibition.

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    Genetic modifications during development of paediatric groups 3 and 4 medulloblastoma are responsible for their highly metastatic properties and poor patient survival rates. PRUNE1 is highly expressed in metastatic medulloblastoma group 3, which is characterized by TGF-β signalling activation, c-MYC amplification, and OTX2 expression. We describe the process of activation of the PRUNE1 signalling pathway that includes its binding to NME1, TGF-β activation, OTX2 upregulation, SNAIL (SNAI1) upregulation, and PTEN inhibition. The newly identified small molecule pyrimido-pyrimidine derivative AA7.1 enhances PRUNE1 degradation, inhibits this activation network, and augments PTEN expression. Both AA7.1 and a competitive permeable peptide that impairs PRUNE1/NME1 complex formation, impair tumour growth and metastatic dissemination in orthotopic xenograft models with a metastatic medulloblastoma group 3 cell line (D425-Med cells). Using whole exome sequencing technology in metastatic medulloblastoma primary tumour cells, we also define 23 common 'non-synonymous homozygous' deleterious gene variants as part of the protein molecular network of relevance for metastatic processes. This PRUNE1/TGF-β/OTX2/PTEN axis, together with the medulloblastoma-driver mutations, is of relevance for future rational and targeted therapies for metastatic medulloblastoma group 3

    RiboAbacus: a model trained on polyribosome images predicts ribosome density and translational efficiency from mammalian transcriptomes

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    Fluctuations in mRNA levels only partially contribute to determine variations in mRNA availability for translation, producing the well-known poor correlation between transcriptome and proteome data. Recent advances in microscopy now enable researchers to obtain high resolution images of ribosomes on transcripts, providing precious snapshots of translation in vivo. Here we propose RiboAbacus, a mathematical model that for the first time incorporates imaging data in a predictive model of transcript-specific ribosome densities and translational efficiencies. RiboAbacus uses a mechanistic model of ribosome dynamics, enabling the quantification of the relative importance of different features (such as codon usage and the 5′ ramp effect) in determining the accuracy of predictions. The model has been optimized in the human Hek-293 cell line to fit thousands of images of human polysomes obtained by atomic force microscopy, from which we could get a reference distribution of the number of ribosomes per mRNA with unmatched resolution. After validation, we applied RiboAbacus to three case studies of known transcriptome-proteome datasets for estimating the translational efficiencies, resulting in an increased correlation with corresponding proteomes. RiboAbacus is an intuitive tool that allows an immediate estimation of crucial translation properties for entire transcriptomes, based on easily obtainable transcript expression levels
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