4,939 research outputs found
Search for neutral MSSM Higgs bosons at CMS
Results on the search for neutral Higgs bosons, in the context of the Minimal Supersymmetric extension of the Standard Model (MSSM), are presented. Different decay channels and final states are considered, including the production of the bosons in association with additional b-quarks and their decay into tau, muon, and b-quark pairs. The exclusion limits are presented in the MSSM mA vs. tan β parameter space. The searches are performed on data samples collected with the Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC) during the 2011 and 2012 data taking periods, in proton-proton collisions at the
center-of-mass energy of 7TeV and 8TeV, respectively
Can the effects of anthropogenic pressures and environmental variability on nekton fauna be detected in fishery data? Insights from the monitoring of the artisanal fishery within the Venice lagoon
Nekton communities in transitional ecosystems are naturally adapted to stressful conditions associated with high environmental variability. Human activities in these systems are likely to determine additional stress with a possible effect on fish fauna, hence on fisheries. In order to test the relative importance of natural and anthropogenic factors in determining changes in nekton community, catches (incl. bycatch) from artisanal fisheries (fyke nets) were monitored seasonally in different areas of the Venice lagoon (Italy) between 2001 and 2013. Changes in nekton community composition and in the biomass of target and non-target species/groups were analysed, and the results were related to temporal factors, environmental characteristics and to the variability in anthropogenic pressures. Statistical tests were carried out using a model-based analysis of both univariate and multivariate data. Results highlighted that temporal factors and environmental conditions (i.e. the main chemico-physical descriptors) are more relevant than anthropogenic pressures in explaining spatial and temporal changes in the lagoon nekton assemblage, but that several characteristics of the assemblage, in particular the biomass of some particular categories and of the whole assemblage, are sensitive to human impacts. A particularly negligible effect seemed to be associated with fishing effort, thus suggesting that the monitoring of the local artisanal fishery is suitable also to provide useful information on the evaluation of the status of nekton assemblage
Linking food web functioning and habitat diversity for an ecosystem based management: A Mediterranean lagoon case-study
We propose a modelling approach relating the functioning of a transitional ecosystem with the spatial extension of its habitats. A test case is presented for the lagoon of Venice, discussing the results in the context of the application of current EU directives. The effects on food web functioning due to changes related to manageable and unmanageable drivers were investigated. The modelling procedure involved the use of steady-state food web models and network analysis, respectively applied to estimate the fluxes of energy associated with trophic interactions, and to compute indices of food web functioning. On the long term (hundred years) temporal scale, the model indicated that the expected loss of salt marshes will produce further changes at the system level, with a lagoon showing a decrease in the energy processing efficiency. On the short term scale, simulation results indicated that fishery management accompanied by seagrass restoration measures would produce a slight transition towards a more healthy system, with higher energy cycling, and maintaining a good balance between processing efficiency and resilience. Scenarios presented suggest that the effectiveness of short term management strategies can be better evaluated when contextualized in the long term trends of evolution of a system. We also remark the need for further studying the relationship between habitat diversity and indicators of food web functioning
Imaging in major salivary gland diseases
Most of the salivary glands diseases are characterized only by a few distinct clinical patterns. Medical history and clinical examination are still considered of great relevance. However, in order to obtaine a definite diagnosis, imaging techniques are required in most of the cases. Salivary glands ultrasonography (US) is the technique to be used as the first because US can easily differentiate calculosis, inflammatory diseases and tumors. Sonography is also frequently needed to perform needle aspiration or biopsy (FNAC). Sialography should be used essentially for assessing chronic sialoadenitis as well as Sjogren's syndrome. At present, Magnetic Resonance sialography should be preferred because of the greater sensibility in diagnosing inflammatory diseases of the salivary glands. It allows to evaluate both intraglandular oedema and nodules, so that incannulation of the salivary duct is not required. Computer Tomography (CT) and Magnetic Resonance imaging (MR) are useful when neoplasm are suspected, particularly if deep areas of the gland, which cannot be visualized by US, are involved. Sequential scintigraphy is currently employed for assessing the functional status of all the 4 major salivary glands and evaluating the chronic evolution of glandular damage
[18F]FDG PET/MRI in rectal cancer
We conducted a systematic literature review on the use of [18F]FDG PET/MRI for staging/restaging rectal cancer patients with PubMed, Scopus, and Web of Science, based on the PRISMA criteria. Three authors screened all titles and abstracts and examined the full texts of all the identified\ua0relevant articles. Studies containing aggregated or duplicated data, review articles, case reports, editorials, and letters were excluded. Ten reports met the inclusion criteria. Four studies examined T staging and one focused on local recurrences after surgery; the reported sensitivity (94\u2013100%), specificity (73\u201394%), and accuracy (92\u2013100%) varied only slightly from one study to another. The sensitivity, specificity, and accuracy of [18F]FDG PET/MRI for N staging were 90\u201393%, 92\u201394%, and 42\u201392%. [18F]FDG PET/MRI detected malignant nodes better than MRI, resulting in treatment change. For M staging, [18F]FDG PET/MRI outperformed [18F]FDG PET/CT and CT in detecting liver metastases, whereas it performed worse for lung metastases. The results of this review suggest that [18F]FDG PET/MRI should be used for rectal cancer restaging after chemoradiotherapy and to select patients for rectum-sparing approaches thanks to its accuracy in T and N staging. For M staging, it should be associated at least with a chest CT scan to rule out lung metastases
IDENTIFICAZIONE DELLE LESIONI POLMONARI IN RM CON UNA SEQUENZA VIBE MODIFICATA E CON UNA SEQUENZA VIBE STANDARD: UN CONFRONTO CON LA TC.
Scopo
valutare l\u2019accuratezza della RM a 3 Tesla nell\u2019individuazione di lesioni polmonari con una
sequenza VIBE modificata e con una sequenza VIBE standard, usando la TC come riferimento.
Materiale e metodi
abbiamo rivalutato retrospettivamente 37 pazienti oncologici (11 pediatrici e 26 adulti; 19 F)
sottoposti a TC e PET/RM da 3T il cui protocollo prevedeva una sequenza VIBE acquisita a
respiro trattenuto con echo time (TE) di 0.89 ms e flip angle (FA) di 3\ub0. Le VIBE sono state
valutate da tre osservatori per l'identificazione di noduli >5mm o =5mm. Un quarto
osservatore ha valutato delle sequenze VIBE standard (TE di 1.2 ms e FA di 10\ub0), anch\u2019esse
incluse nel protocollo, ed infine un quinto lettore ha analizzato le immagini TC (considerate
come standard di riferimento).Sia per paziente che per singola lesione sono state calcolate
sensibilit\ue0 e specificit\ue0 per le due categorie di noduli ed il coefficiente di correlazione intraclasse
(ICC) per i lettori delle VIBE modificate.
Risultati
analisi per paziente (positivit\ue0=1 lesione): sensibilit\ue0 84.6% e specificit\ue0 di 100% per
noduli>5mm (VIBE standard 69.2% e 100%) e 44.4% e 100% per noduli=5mm (VIBE standard
33.3% e 100%). Analisi per lesione (presenza/assenza): sensibilit\ue0 di 83.9% per noduli>5mm
(VIBE standard 67.74%) e 37.5% per noduli=5mm (VIBE standard 18.7%). L\u2019ICC nell\u2019analisi
per paziente era 0.911 per noduli>5mm e 0.902 per noduli=5mm; nell\u2019analisi per lesione
0.866 per noduli>5mm e 0.699 per noduli=5mm.
Conclusioni
la sequenza VIBE modificata \ue8 riproducibile ed accurata per l\u2019individuazione di noduli >5mm,
mentre l\u2019accuratezza risulta meno soddisfacente per i noduli=5mm. L\u2019utilizzo della sequenza
modificata nei protocolli RM sembra ragionevole per migliorare la visualizzazione del polmone
Ionotropic and metabotropic signalling in neuronal development and differentiation
This thesis investigates ionotropic and metabotropic signalling mechanisms in developing neurons from human embryonic stem cell and primary sources. Focus is placed on the measurement of functional activity using primarily whole-cell patchclamp and Ca2+ imaging techniques These signalling mechanisms were investigated in undifferentiated human embryonic stem cells, hESC-derived neurons, fetal primary human neurons and neonatal primary mouse neurons. The results of this research are separated into three chapters. Preliminary work carried out on iPSC-derived neurons is also included as an indication of future direction Chapter 3: P2 Receptors in hESCs Purinergic signalling was shown to be active in undifferentiated hESC populations. Specifically, the activity of P2Y1 receptors was confirmed pharmacologically. This is a novel observation and indicates a mechanism for physiologically relevant signalling molecules to modify [Ca2+]i Chapter 4: Functional Characterisation of hESC-Derived and Primary Neurons Functional characteristics associated with neuronal development were measured in human embryonic stem cells during terminal neuronal differentiation in a chemically-defined medium. The presence and activity of voltage-gated Na+, K+ and Ca2+ channels were recorded, alongside data on neuronal excitability (Vm, iAP induction and threshold and spontaneous electrical activity). These data were also recorded in fetal hWGE- and neonatal mWGE-derived neurons for comparison. hESC-derived neurons were shown to be functionally more similar to fetal hWGEneurons suggesting an immature neuronal phenotype Chapter 5: GABAergic Signalling in hESC-Derived and Primary Neurons GABAergic signalling in hESC-, mWGE- and hWGE-derived neuronal populations was investigated. Focus was placed on hWGE-derived neurons and the developmental state of GABAergic responses. In fetal hWGE-derived neurons, a percentage of cells displayed an ‘inhibitory’ response to GABAAR activation. This is a novel observation with implications in human neuronal development. In vitro modulation of GABAergic signalling was also shown, providing potential tools for future research into this phenomenon Chapter 6: Future Developments and General Discussion iPSC-derived neuronal populations were shown to display basic neuronal functional properties. This work will form the basis of future studies on these cellsEThOS - Electronic Theses Online ServiceGBUnited Kingdo
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