636 research outputs found
Irrelevant Operators and their Holographic Anomalies
Irrelevant operators in a CFT modify the usual Weyl transformation of the metric. A metric beta-function turns on, which modifies the Weyl anomalies as well. In this paper, we study the relation between bulk diffeomorphisms and Weyl transformation at the boundary when a massive scalar field, which sources irrelevant operators at the boundary, is coupled to the bulk metric. Considering the effect of the backreaction generated by the scalar field, we provide a holographic description of the boundary metric beta-function and anomalies. Our results represent an additional test of the AdS/CFT correspondence
Correlation functions and quantum measures of descendant states
We discuss a computer implementation of a recursive formula to calculate correlation functions of descendant states in two-dimensional CFT. This allows us to obtain any N-point function of vacuum descendants, or to express the correlator as a differential operator acting on the respective primary correlator in case of non-vacuum descendants. With this tool at hand, we then study some entanglement and distinguishability measures between descendant states, namely the Renyi entropy, trace square distance and sandwiched Renyi divergence. Our results provide a test of the conjectured Renyi QNEC and new challenges for the holographic description of descendant states at large c
The Third Way to Interacting p-form Theories
We construct a class of interacting -form theories in dimensions that are `third way' consistent. This refers to the fact that the interaction terms in the -form field equations of motion neither come from the variation of an action nor are they off-shell conserved on their own. Nevertheless the full equation is still on-shell consistent. Various generalizations, e.g. coupling them to -forms, where 3-algebras play a prominent role, are also discussed. The method to construct these models also easily recovers the modified 3 Yang-Mills theory obtained earlier and straightforwardly allows for higher derivative extensions
Physiological responses of garden cress (L. sativum) to different types of microplastics
In this study, for the first time, acute and chronic toxicity caused by four different kinds of microplastics: polypropylene (PP), polyethylene (PE), polyvinylchloride (PVC), and a commercial mixture (PE + PVC) on Lepidium sativum were evaluated. Parameters considered were: i) biometric parameters (e.g. percentage inhibition of seed germination, plant height, leaf number and fresh biomass productions); and ii) oxidative stress (e.g. levels of hydrogen peroxide, glutathione, and ascorbic acid). On plants exposed to chronic stress chlorophylls, carotenoids, aminolaevulinic acid, and proline productions were, also, evaluated. PVC resulted the most toxic than other plastic materials tested. This study represents the first paper highlighting microplastics are able to produce oxidative burst in tested plants and could represent an important starting point for future researches on biochemical effects of microplastic in terrestrial environments such as agroecosystems
Chemical composition of microplastic in sediments and protected detritivores from different marine habitats (Salina Island)
This study estimates chemical composition of microplastic in sediments and benthic detritivores (sea cucumbers) collected from different marine rocky bottom habitat types (bank, landslide, cliff) of Salina Island (Aeolian Archipelago, Italy). Also, species richness and bottom coverings by benthic species were recorded at each sampling station. Correlations among chemical composition of microplastic in sediments and in detritivores were explored linking recorded variability to the factor \u201chabitat type\u201d. Results evidence that the habitat types considered in this study are characterized by wide species richness and by high percentages of bottom coverage by protected species by international conventions. In spite of the high ecological value of habitats considered in this study, microplastics were recorded both in sediments (PVC, PET, PE, PS, PA, PP) and in stomach contents of sea cucumbers (PET, PA) collected in all sampling sites, confirming the exposure of benthic species to microplastic pollution
Ecotoxicity of basil (Ocimum Basilicum) extract in aquaculture feeds: Is it really eco-safe for the aquatic environment?
Plant extract and essential oils are gaining application in aquaculture, but data about their environmental impact are limited and their potential effects on aquatic organisms are largely unknown. For this study, ecotoxicity tests were performed under standardized conditions on fish feed supplemented with 3 % w/w of a basil supercritical extract (F1-BEO; substance A), F1-BEO extract (substance B), and fish feed without F1-BEO extract (substance C) on three model species of different trophic levels (bacteria, primary producer, primary consumer) considered representative for freshwater (Aliivibrio fischeri, Raphidocelis subcapitata, Daphnia magna) and marine (A. fischeri, Phaeodactylum tricornutum, Paracentrotus lividus) ecosystems. Ecotoxicological response was largely comparable within the same trophic level (whichever the ecosystem). EC50 was not calculable in the concentration range here tested (3.9–500 mg/L) for freshwater and marine microalgae, suggesting that none of the substances were toxic for primary producers. Reduction of A. fischeri bioluminescence at the tested concentration (0.5–10 mg/L) was observed only for substance A (EC50 9.53 mg/L and 9 mg/L for freshwater and marine ecosystems, respectively). Notably, in P. lividus embryotoxicity was higher for substances A (EC50 1.80 mg/L) and C (EC50 4.6 mg/L) than for substance B (EC50 7.10 mg/L), suggesting a toxic effect due to feed dissolution. In contrast, substance B was more toxic (EC50 0.34 mg/L) in D. magna than substances A (EC50 3.98 mg/L) and C (EC50 5.50 mg/L). Based on the Globally Harmonized System of Classification and Labelling of Chemicals, all substances were categorized Acute 2, except for substance A which was categorized Acute 1 for D. magna. Overall, the substances were found to be potentially toxic for an aquatic ecosystem, especially for primary consumer. Further study of plant extract and essential oils is needed to better understand their effects and fate on the aquatic environment
IL MODELLO DI REGRESSIONE QUANTILE NELL’ANALISI DELLE DETERMINANTI DELLA QUALITA’ DELLA VITA IN UNA POPOLAZIONE ANZIANA
Obiettivi. L\u2019obiettivo di questo studio \ue8 spiegare l\u2019associazione tra alcune importanti covariate e la qualit\ue0 della vita percepita (HRQoL) in soggetti anziani. Metodi. I dati sono stati raccolti nell\u2019ambito di uno studio longitudinale che coinvolge 5256 soggetti ultrasesantacinquenni. La scala-termometro del questionario EQ-5D, la EQ-VAS, \ue8 stata utilizzata per ottenere una misura sintetica di qualit\ue0 della vita. L\u2019EQ-VAS Score \ue8 stato modellato utilizzando la regressione quantile. Questo approccio metodologico \ue8 stato preferito alla regressione lineare a causa della particolare distribuzione del punteggio EQ-VAS. Le principali covariate inserite nel modello sono: quantit\ue0 settimanale di attivit\ue0 fisica, capaocit\ue0 di svolgimento delle attivit\ue0 quotidiane ( questionari ADL e IADL ), presenza di patologie cardiovascolari, diabete, ipertensione e colesterolo, dolori articolare e informazioni socio-demografiche. Principali Risultati. 1) Anche valori bassi di attivit\ue0 fisica sono associati significativamente ed in modo positivo alla qualit\ue0 della vita percepita. 2) Problemi nella attivit\ue0 quotidiane, almeno un evento cardiovascolare e dolori articolari contribuiscono fortemente a ridurre il punteggio EQ-VAS
Role of PET/CT in the detection of liver metastases from colorectal cancer
The aim of this study was to compare the diagnostic accuracy of 2-[fluorine-18] fluoro-2-deoxy-D-glucose positron emission tomography (F-18-FDG-PET) and computed tomography (CT) with PET/CT in the detection of liver metastases during tumour staging in patients suffering from colorectal carcinoma for the purposes of correct surgical planning and follow-up. A total of 467 patients underwent a PET/CT scan using an iodinated contrast medium. We compared images obtained by the single PET scan, the single CT scan and by the fusion of the two procedures (PET/CT). The final diagnosis was obtained by histological examination and/or by the follow-up of all patients, including those who did not undergo surgery or biopsy. The PET scan had 94.05% sensitivity, 91.60% specificity and 93.36% accuracy; the CT scan had 91.07% sensitivity, 95.42% specificity and 92.29% accuracy. The combined procedures (PET/CT) had the following values: sensitivity 97.92%, specificity 97.71% and accuracy 97.86%. This study indicates that PET/CT is very useful in staging and restaging patients suffering from colorectal cancer. It was particularly useful when recurrences could not be visualised either clinically or by imaging despite increasing tumour markers, as it guaranteed an earlier diagnosis. PET/CT not only provides high diagnostic performance in terms of sensitivity and specificity, enabling modification of patient treatment, but it is also a unique, high-profile procedure that can produce cost savings
CRISPR/Cas9-induced inactivation of the autism risk gene setd5 leads to social impairments in zebrafish
Perturbation of cytochrome P450, generation of oxidative stress and induction of DNA damage in Cyprinus carpio exposed in situ to potable surface water
Epidemiological evidence suggests a link between consumption of chlorinated drinking water and various cancers. Chlorination of water rich in organic chemicals produces carcinogenic organochlorine by-products (OBPs) such as trihalomethanes and haloacetic acids. Since the discovery of the first OBP in the 1970s, there have been several investigations designed to determine the biological effects of single chemicals or small artificial OBP combinations. However, there is still insufficient information regarding the general biological response to these compounds, and further studies are still needed to evaluate their potential genotoxic effects. In the current study, we evaluated the effect of three drinking water disinfectants on the activity of cytochrome P450 (CYP)-linked metabolizing enzymes and on the generation of oxidative stress in the livers of male and female Cyprinus carpio fish (carp). The fish were exposed in situ for up 20 days to surface water obtained from the Trasmene lake in Italy. The water was treated with 1-2 mg/L of either sodium hypochlorite (NaClO) or chlorine dioxide (ClO2) as traditional disinfectants or with a relatively new disinfectant product, peracetic acid (PAA). Micronucleus (MN) frequencies in circulating erythrocytes from the fish were also analysed as a biomarker of genotoxic effect. In the CYP-linked enzyme assays, a significant induction (up to a 57-fold increase in the deethylation of ethoxyresorufin with PAA treatment) and a notable inactivation (up to almost a 90% loss in hydroxylation of p-nitrophenol with all disinfectants, and of testosterome 2 beta-hydroxylation with NaClO) was observed in subcellular liver preparations from exposed fish. Using the electron paramagnetic resonance (EPR) spectroscopy radical-probe technique, we also observed that CYP-modulation was associated with the production of reactive oxygen species (ROS). In addition, we found a significant increase in MN frequency in circulating erythrocytes after 10 days of exposure of fish to water treated with ClO2, while a non-significant six-fold increase in MN frequency was observed with NaClO, but not with PAA. Our data suggest that the use of ClO2 and NaClO to disinfect drinking water could generate harmful OBP mixtures that are able to perturb CYP-mediated reactions, generate oxidative stress and induce genetic damage. These data may provide a mechanistic explanation for epidemiological studies linking consumption of chlorinated drinking water to increased risk of urinary, gastrointestinal and bladder cancers. (c) 2006 Elsevier B.V. All rights reserved
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