Tunnelling Effects in a Brane System and Quantum Hall Physics

We argue that a system of interacting D-branes, generalizing a recent proposal, can be modelled as a Quantum Hall fluid. We show that tachyon condensation in such a system is equivalent to one particle tunnelling. In a conformal field theory effective description, that induces a transition from a theory with central charge c=2 to a theory with c=3/2, with a corresponding symmetry enhancement.Comment: 12 pages, no figures, Latex, some aspects clarified, sect.3 expanded, references adde

On off-shell bosonic string amplitudes

We give a simple prescription for computing, in the framework of the bosonic string theory, off-shell one-loop amplitudes with any number of external massless particles, both for the open and for the closed string. We discuss their properties and, in particular, for the two-string one-loop amplitudes we show their being transverse.Comment: 12 pages, Latex. One reference added. Introduction and conclusions expanded. Some other minor changes in the tex

A decision-support system in ICZM for protecting the ecosystems: integration with the habitat directive

This paper describes a decision-support system based on landscape ecology and focused on the study of ecosystems\u27 health. System capabilities are illustrated with three cases of integrated coastal zone management(ICZM), in the Adriatic Sea (Italy): the lagoon of and the Rimini and Ancona coastal areas. Indicators and indices are developed with a focus on sub-regional and local problems in coastal management, with a multi- approach based on landscape and seascape ecology. Land-use changes of the coastal areas were detected by analyzing two sets of satellite images. Indices combining satellite imagery, socio-economic and environmental indicators, and landscape and seascape maps created, showing ecological changes, habitat loss and gaps in conservation policy. The approach used provides means for the identification of conflicts and for the assessment of sustainability. Results show that the lagoon of Venice plays an important role in mitigating and compensating the impacts of human activities, and needs to be protected and restored. The Rimini area shows high ecological footprint and development-intensity and low biocapacity. The Ancona area needs the protection of its natural coastal space from potential sources of anthropo-genic impacts to maintain its sustainability. A model of environment changes is critical for formulating effective environmental policies and management strategies. The developed decision-support system provides a suitability map per each area analyzed, which can be used in order to maximize different policy objectives and reduce coastal conflicts

Volatiles from steam-distilled leaves of some plant species from Madagascar and New Zealand and evaluation of their biological activity.

Steam-distilled aerial parts of Ravensara Aromatica and Cinnamomum camphora from Madagascar and Leptospermum scoparium from New Zealand have been subjected to qualitative and quantitative analysis by means of GC techniques. This allowed the elucidation of conflicting data present in the available literature for these species. Also, the biological activity in vitro was evaluated by measuring MICs and GIZs

Preliminary Validation of the CI-FRA Checklist: A Simple Screening Tool for Measuring the Early Signs of Reading and Spelling Disorders in Italian Primary Students

Although several screening tests for recognizing early signs of reading and spelling difficulties have been developed, brief and methodologically grounded tools for teachers are very limited. The present study aimed to lay the foundation for a new screening tool for teachers: the Checklist for early Indicators of risk Factors in Reading Ability (CI-FRA). The proposed checklist consists of 20 items, based on a 7-point Likert scale, and it investigates five domains: reading, writing, attention, and motor skills. Six hundred sixtyseven children were evaluated by 40 teachers during the first year of primary school and, longitudinally, in the second year. Exploratory factor analysis and confirmatory factor analysis (CFA) were applied to verify structural validity. Concurrent validity was assessed by Spearman correlation to analyze the link between CI-FRA and reading and spelling standardized tests and cognitive tests. Reliability was assessed by Cronbach a and interclass correlation coefficient. The CFA reported a three-factor structure as the optimal solution, including language (reading and writing), visuospatial attention, and fine motor skills subscales. Good reliability, good internal consistency, and acceptable test\u2013 retest indices were found. Concurrent validity was confirmed by significant correlations between CI-FRA total score and standardized reading and spelling test, as well as by correlations between CI-FRA subscales and neuropsychological standardized test scores. Preliminary evaluation of sensitivity by receiver operating characteristic curves showed that the CI-FRA score has particularly high sensitivity and specificity for word reading speed deficit. In conclusion, the results confirm that CI-FRA is a theoretically grounded and statistically valid tool that could help the teachers to screen for early signs of reading and spelling difficulties

Retinoic Acid Specifically Enhances Embryonic Stem Cell Metastate Marked by Zscan4

Pluripotency confers Embryonic Stem Cells (ESCs) the ability to differentiate in ectoderm, endoderm, and mesoderm derivatives, producing the majority of cell types. Although the majority of ESCs divide without losing pluripotency, it has become evident that ESCs culture consists of multiple cell populations with different degrees of potency that are spontaneously induced in regular ESC culture conditions. Zscan4, a key pluripotency factor, marks ESC subpopulation that is referred to as high-level of pluripotency metastate. Here, we report that in ESC cultures treated with retinoic acid (RA), Zscan4 ESCs metastate is strongly enhanced. In particular, we found that induction of Zscan4 metastate is mediated via RA receptors (RAR-alpha, RAR-beta, and RAR-gamma), and it is dependent on phosphoinositide-3-kinase (PI3K) signaling. Remarkably, Zscan4 metastate induced by RA lacks canonical pluripotency genes Oct3/4 and Nanog but retained both self-renewal and pluripotency capabilities. Finally we demonstrated that the conditional ablation of Zscan4 subpopulation is dispensable for both endoderm and mesoderm but is required for ectoderm lineage. In conclusion, our research provides new insights about the role of RA signaling during ESCs high pluripotency metastate fluctuation

Differences of myocardial systolic deformation and correlates of diastolic function in competitive rowers and young hypertensives: a speckle-tracking echocardiography study

The aim of this study was to compare speckle-tracking echocardiography–derived left ventricular (LV) systolic mechanics and their relationships with LV diastolic properties in young patients with hypertension and in young competitive athletes in relation to their respective alterations of LV structure. Nineteen sedentary controls, 22 top-level rowers, and 18 young newly diagnosed, never-treated patients with hypertension, all male, underwent Doppler echocardiography including pulsed tissue Doppler of the mitral annulus and speckle-tracking echocardiography. Peak longitudinal strain was calculated in apical long-axis, four-chamber, and two-chamber views, and values of the three views were averaged (global longitudinal strain [GLS]). Regional circumferential and radial strain were calculated at the LV basal, middle, and apical levels, and values were averaged. LV torsion was determined as the net difference in the mean rotation between the apical and basal levels. The three groups were comparable for age, whereas body mass index and blood pressure were higher in patients with hypertension, and heart rate was lower in rowers. LV mass index was higher in rowers and in patients with hypertension than in controls, without differences in relative wall thickness, ejection fraction, and midwall shortening. Left atrial volume index was greater in rowers than in controls and patients with hypertension. Annular systolic velocity (s0) (P < .001) and early diastolic velocity (e0) (P < .0001) were lower and the E/e0 ratio was higher (P < .0001) in patients with hypertension. GLS was lower in patients with hypertension than in rowers and in controls (P < .0001). Global circumferential strain, global radial strain, and torsion were similar among the three groups. In the pooled population, GLS was an independent contributor to E/e0 ratio (P < .0001) after adjusting for age, heart rate, meridional end-systolic stress, LV mass index and left atrial volume index. By receiver operating characteristic curve analyses, both GLS and E/e0 ratio appeared to be accurate in discriminating patients with hypertension from healthy controls, with the E/e0 ratio being more sensitive (77.8%) and GLS more specific (89.5%). The hearts of young patients with hypertension are characterized by reduced GLS, whereas global circumferential strain, global radial strain, and torsion are similar to those of athletes’ hearts. The extent of GLS is strongly associated with LV diastolic function, independently of afterload changes and the degree of LV hypertrophy

Prognostic role of BNP in children undergoing surgery for congenital heart disease: analysis of prediction models incorporating standard risk factors.

BACKGROUND: The routine use of brain natriuretic peptide (BNP) in pediatric cardiac surgery remains controversial. Our aim was to test whether BNP adds information to predict risk in pediatric cardiac surgery. METHODS: In all, 587 children undergoing cardiac surgery (median age 6.3 months; 1.2-35.9 months) were prospectively enrolled at a single institution. BNP was measured pre-operatively, on every post-operative day in the intensive care unit, and before discharge. The primary outcome was major complications and length ventilator stay \u3e15 days. A first risk prediction model was fitted using Cox proportional hazards model with age, body surface area and Aristotle score as continuous predictors. A second model was built adding cardiopulmonary bypass time and arterial lactate at the end of operation to the first model. Then, peak post-operative log-BNP was added to both models. Analysis to test discrimination, calibration, and reclassification were performed. RESULTS: BNP increased after surgery (p CONCLUSIONS: Our data indicates that BNP may improve the risk prediction in pediatric cardiac surgery, supporting its routine use in this setting

Investigating the cecal microbiota in broiler poultry farms and its potential relationships with animal welfare

The present study assessed the modulation of cecal microbiota and correlations with Campylobacter colonization and animal welfare status. For these purposes, we conducted a cross sectional study of the cecal microbiota from 187 broilers reared in 13 batches from 10 poultry farms by performing 16S rRNA sequencing (regions V3–4). The welfare of each batch was assessed using a simplified Welfare Quality® protocol, scoring higher in organic batches, compared to both antibiotic-free and conventional batches. The bioinformatics analyses were conducted in QIIME 2 and a linear discriminant analysis determined the association between microbiota and animals with different Campylobacter carriage status and welfare levels. In the microbiota from the subjects negative for Campylobacter or with high welfare scores, Bacteroidetes was the predominant phylum with the genus Megamonas significantly increased in abundance. A greater abundance of Parabacteroides, Phascolarctobacterium, Helicobacter in poultry negative for Campylobacter was also found at the genus level. Animals with the lowest welfare scores showed an increased abundance of Proteobacteria. The results suggested a different microbial composition and diversity in the analyzed groups.Italian Ministry of Health with the Ricerca Corrente 2016 funds, project IZSAM 04/16 RC (Fondo Sanitario Nazionale).https://www.elsevier.com/locate/rvscam2023Production Animal Studie