696 research outputs found
The GEMAS Project: Geochemistry of European agricultural and grazing land soils.
Viene illustrato il progetto GEMAS che ha interessato la campionatura e le analisi di suoli dell'ntero continente Europeo da parte dei Servizi Geologici d'Europa, nell'ìambito delle attività dell'EuroGeoSurvey
Compact smallest eigenvalue expressions in Wishart-Laguerre ensembles with or without fixed-trace
The degree of entanglement of random pure states in bipartite quantum systems
can be estimated from the distribution of the extreme Schmidt eigenvalues. For
a bipartition of size M\geq N, these are distributed according to a
Wishart-Laguerre ensemble (WL) of random matrices of size N x M, with a
fixed-trace constraint. We first compute the distribution and moments of the
smallest eigenvalue in the fixed trace orthogonal WL ensemble for arbitrary
M\geq N. Our method is based on a Laplace inversion of the recursive results
for the corresponding orthogonal WL ensemble by Edelman. Explicit examples are
given for fixed N and M, generalizing and simplifying earlier results. In the
microscopic large-N limit with M-N fixed, the orthogonal and unitary WL
distributions exhibit universality after a suitable rescaling and are therefore
independent of the constraint. We prove that very recent results given in terms
of hypergeometric functions of matrix argument are equivalent to more explicit
expressions in terms of a Pfaffian or determinant of Bessel functions. While
the latter were mostly known from the random matrix literature on the QCD Dirac
operator spectrum, we also derive some new results in the orthogonal symmetry
class.Comment: 25 pag., 4 fig - minor changes, typos fixed. To appear in JSTA
The progesterone receptor Val660→Leu polymorphism and breast cancer risk
BACKGROUND: Recent evidence suggests a role for progesterone in breast cancer development and tumorigenesis. Progesterone exerts its effect on target cells by interacting with its receptor; thus, genetic variations, which might cause alterations in the biological function in the progesterone receptor (PGR), can potentially contribute to an individual's susceptibility to breast cancer. It has been reported that the PROGINS allele, which is in complete linkage disequilibrium with a missense substitution in exon 4 (G/T, valine→leucine, at codon 660), is associated with a decreased risk for breast cancer. METHODS: Using a nested case-control study design within the Nurses' Health Study cohort, we genotyped 1252 cases and 1660 matched controls with the use of the Taqman assay. RESULTS: We did not observe any association of breast cancer risk with carrying the G/T (Val660→Leu) polymorphism (odds ratio 1.10, 95% confidence interval 0.93–1.30). In addition, we did not observe an interaction between this allele and menopausal status and family history of breast cancer as reported previously. CONCLUSION: Overall, our study does not support an association between the Val660→Leu PROGINS polymorphism and breast cancer risk
Relationship between distance run per week, omega-3 index, and arachidonic acid (AA)/eicosapentaenoic acid (EPA) ratio: An Observational Retrospective Study in Non-elite Runners
Background: Tissue availability of polyunsaturated fatty acids (PUFA) depends on several factors, including dietary intake, physical exercise, genetic variation, and metabolic turnover. However, there is limited evidence whether running training activity per se may influence indices associated with PUFA metabolism such as Omega-3 (ω-3) index and arachidonic acid (AA; 20:4ω-6)/eicosapentaenoic acid (EPA; 20:5ω-3) ratio. Objective: To examine the association between kilometers (Km) run per week and changes in ω-3 index and AA/EPA ratio. Methods: We conducted a retrospective, observational, cohort study of 257 non-elite runners (mean age: 40.85 ± 12.17 years) who consumed no fatty acid supplements and provided a blood sample for analysis. The whole blood samples were collected by finger sticks, stored on absorbent filter paper, and then PUFA were quantified by gas chromatography (GC) and ω-3 index and AA/EPA ratio measured. Results: In a multivariate linear regression model, a gradual decrease of the ω-3 index was observed with higher weekly running distance (β = −0.033; 95% CI −0.039 to −0.026; R2 = 0.447; p < 0.0001). We also found a progressive increase of the AA/EPA ratio in subjects who ran greater weekly distances (β = 0.092; 95% CI 0.038 to 0.146; R2 = 0.320; p = 0.001). No other significant associations were observed with other variables, including years of running training and weekly training frequency (hours/week). Finally, as expected, a significant inverse correlation between ω-3 index and AA/EPA ratio (β = −2.614; 95% CI −3.407 to −1.821; R2 = 0.336; p < 0.0001) was detected. Conclusions: These findings suggest that distance running training and its weekly volume may negatively contribute to changes of the ω-3 index and AA/EPA ratio. Further studies with greater sample size will be required to replicate and extend these data
Hepatitis E virus sequences in swine related to sequences in humans, The Netherlands.
Hepatitis E virus (HEV), a major cause of viral hepatitis in much of the developing world, has recently been detected in swine in North America and Asia, raising concern about potential for zoonotic transmission. To investigate if HEV is commonly present in swine in the Netherlands, pooled stool samples from 115 swine farms and nine individual pigs with diarrhea were assayed by reverse transcription-polymerase chain reaction (RT-PCR) amplification. HEV RNA was detected by RT-PCR and hybridization in 25 (22%) of the pooled specimens, but in none of the individual samples. RT-PCR amplification products of open reading frames 1 and 2 were sequenced, and the results were compared with published sequences of HEV genotypes from humans and swine. HEV strains from swine in the Netherlands were clustered in at least two groups, together with European and American isolates from swine and humans. Our data show that HEV in swine in the Netherlands are genetically closely related to HEV isolates from humans. Although zoonotic transmission has not been proven, these findings suggest that swine may be reservoir hosts of HEV
Radiographers and COVID-19 pneumonia: diagnostic performance using CO-RADS
Introduction: A more structured role of radiographers is advisable to speed up the management of patients with suspected COVID-19. The purpose of our study was to evaluate the diagnostic performance of radiographers in the detection of COVID-19 pneumonia on chest CT using CO-RADS descriptors. Methods: CT images of patients who underwent RT-PCR and chest CT due to COVID-19 suspicion between March and July 2020 were analysed retrospectively. Six readers, including two radiologists, two highly experienced radiographers and two less experienced radiographers, independently scored each CT using the CO-RADS lexicon. ROC curves were used to investigate diagnostic accuracy, and Fleiss’κ statistics to evaluate inter-rater agreement. Results: 714 patients (419 men; 295 women; mean age: 64 years ±19SD) were evaluated. CO-RADS> 3 was identified as optimal diagnostic threshold. Highly experienced radiographers achieved an average sensitivity of 58.7% (95%CI: 52.5–64.7), an average specificity of 81.8% (95%CI: 77.9–85.2), and a mean AUC of 0.72 (95%CI: 0.68–0.75). Among less experienced radiographers, an average sensitivity of 56.3% (95%CI: 50.1–62.2) and an average specificity of 81.5% (95%CI: 77.6–84.9) were observed, with a mean AUC of 0.71 (95%CI: 0.68–0.74). Consultant radiologists achieved an average sensitivity of 60.0% (95%CI: 53.7–65.8), an average specificity of 81.7% (95%CI: 77.8–85.1), and a mean AUC of 0.73 (95%CI: 0.70–0.77). Conclusion: Radiographers can adequately recognise the classic appearances of COVID-19 on CT, as described by the CO-RADS assessment scheme, in a way comparable to expert radiologists. Implications for practice: Radiographers, as the first healthcare professionals to evaluate CT images in patients with suspected SARS-CoV-2 infection, could diagnose COVID-19 pneumonia by means of a categorical reporting scheme at CT in a reliable way, hence playing a primary role in the early management of these patients
Gene × Gene interaction between MnSOD and GPX-1 and breast cancer risk: a nested case-control study
BACKGROUND: Germ-line mutations in genes such as BRCA1, BRCA2, and ATM can cause a substantial increase in risk of breast cancer. However, these mutations are rare in the general population, and account for little of the incidence of sporadic breast cancer in the general population. Therefore, research has been focused on examining associations between common polymorphisms and breast cancer risk. To date, few associations have been described. This has led to the hypothesis that breast cancer is a complex disease, whereby a constellation of very low penetrance alleles need to be carried to present a risk phenotype. Polymorphisms in the manganese superoxide dismutase (MnSOD) and glutathione peroxidase (GPX-1) genes have been proposed as low penetrance alleles, and have not been clearly associated with breast cancer. We investigated whether variants at both polymorphisms, while not independently associated with breast cancer risk, could influence breast cancer risk when considered together. METHODS: A case-control study nested within the Nurses' Health Study was performed comparing 1262 women diagnosed with breast cancer to 1533 disease free women. The MnSOD (Val16Ala, rs1799725) and GPX-1 (Pro198Leu, rs1050450) were genotyped via TaqMan assay. Disease risk was evaluated using logistic regression. RESULTS: While neither allele alone shows any change in breast cancer risk, an increase in the risk of breast cancer (OR 1.87, 95% CI 1.09 – 3.19) is observed in individuals who carry both the Ala16Ala genotype of MnSOD and the Leu198Leu genotype of GPX-1. CONCLUSION: Polymorphisms in the GPX-1 and MnSOD genes are associated with an increased risk of breast cancer
Combination disease-modifying treatment in spinal muscular atrophy: A proposed classification
We sought to devise a rational, systematic approach for defining/grouping survival motor neuron-targeted disease-modifying treatment (DMT) scenarios. The proposed classification is primarily based on a two-part differentiation: initial DMT, and persistence/discontinuation of subsequent DMT(s). Treatment categories were identified: monotherapy add-on, transient add-on, combination with onasemnogene abeparvovec, bridging to onasemnogene abeparvovec, and switching to onasemnogene abeparvovec. We validated this approach by applying the classification to the 443 patients currently in the RESTORE registry and explored the demographics of these different groups of patients. This work forms the basis to explore the safety and efficacy profile of the different combinations of DMT in SMA
Clinical and neurocognitive predictors of functional outcome in depressed patients with partial response to treatment: one year follow-up study
Background: Cognitive dysfunction represents a distinct biological and clinical dimension in major depression disorders (MDD) and cognitive performance strongly affects psychosocial functioning in patients diagnosed with MDD. Objective: To assess which neurocognitive variables at baseline predict the functional outcome of MDD patients in a 1-year follow-up study as assessed by Functioning Assessment Short Test (FAST) and whether the improvement observed on affective and cognitive symptoms in our 12 week-prospective observational study after treatment with selective serotonin reuptake inhibitors (SSRIs) and selective noradrenalin reuptake inhibitors (SNRIs) can affect the following long-term psychosocial functional outcome at 1 year in the same MDD patients. Methods: We recruited a total of 31 patients (8 males; 23 females) with MDD who had previously completed a pharmacological treatment with SSRIs (n = 22) or SNRIs (n = 9) for 12 weeks, and then continued the same pharmacological treatment for 1 year. After an average 1-year follow-up, they were interviewed with the FAST to assess functional outcome. Multivariate analyses were applied to identify clinical and neurocognitive predictors of functional outcome. Results: Total Montreal Cognitive Assessment (MoCA), Digit Span forward (Span F) and backward (Span B), and 15 Rey words immediate recall (Rey I) scores significantly correlated with FAST. However, after performing regression models only Rey immediate recall score was useful to predict long-term functional outcome (Pearson correlation coefficient R= -0.68, p < 0.001) in four specific subdomains of FAST. When considering changes in affective and cognitive symptoms at the end of the 12 weeks of pharmacological treatment with SSRI or SNRIs (T1-T0) by multiple regression analysis, we found that Span F-test predicted scores in the FAST leisure domain, whereas, changes in Span F, Frontal Assessment Battery (FAB) and Rey I predicted psychosocial functioning in the specific 'cognitive' subdomains of FAST. Conclusion: Our data suggest that long-term psychosocial functioning can be influenced by neurocognitive performance at baseline, with verbal memory playing a key role in overall functioning. Furthermore, improvement in verbal memory can predict functional outcome at one year in MDD patients with a recent history of partial response to antidepressants
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