84 research outputs found

    Psychological outcomes of local heritage engagement: participation in community archeological excavations increases well‐being, self‐efficacy, and perceived community support

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    There is evidence that engagement with tangible heritage is linked to improvements in well-being. However, experimental tests of this association, as well as theoretical accounts explaining this relationship, are lacking. The present study aims to compensate for this gap by developing a theoretical framework based on the social identity approach that explains the effect of community-based heritage engagement on well-being, and testing this effect in a quasi-experimental field study in the context of community test pit archeological excavations. In line with the predictions, the results demonstrate that excavation participants (but not participants in the control condition) report improvements on a number of psychological outcomes after (as compared to before) participation in a 2-day excavation program (including well-being, self-efficacy, and perceived community support). The findings offer implications for community-based approaches to enhancing well-being, as well as the practice of conducting community-based archeological excavations.Social decision makin

    Characterization of structural bone properties through portable single-sided nmr devices: State of the art and future perspectives

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    Nuclear Magnetic Resonance (NMR) is a well-suited methodology to study bone composition and structural properties. This is because the NMR parameters, such as the T2 relaxation time, are sensitive to the chemical and physical environment of the1H nuclei. Although magnetic resonance imaging (MRI) allows bone structure assessment in vivo, its cost limits the suitability of conventional MRI for routine bone screening. With difficulty accessing clinically suitable exams, the diagnosis of bone diseases, such as osteoporosis, and the associated fracture risk estimation is based on the assessment of bone mineral density (BMD), obtained by the dual-energy X-ray absorptiometry (DXA). However, integrating the information about the structure of the bone with the bone mineral density has been shown to improve fracture risk estimation related to osteoporosis. Portable NMR, based on low-field single-sided NMR devices, is a promising and appealing approach to assess NMR properties of biological tissues with the aim of medical applications. Since these scanners detect the signal from a sensitive volume external to the magnet, they can be used to perform NMR measurement without the need to fit a sample inside a bore of a magnet, allowing, in principle, in vivo application. Techniques based on NMR single-sided devices have the potential to provide a high impact on the clinical routine because of low purchasing and running costs and low maintenance of such scanners. In this review, the development of new methodologies to investigate structural properties of trabecular bone exploiting single-sided NMR devices is reviewed, and current limitations and future perspectives are discussed

    Challenges in the use of artificial intelligence for prostate cancer diagnosis from multiparametric imaging data

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    Many efforts have been carried out for the standardization of multiparametric Magnetic Resonance (mp-MR) images evaluation to detect Prostate Cancer (PCa), and specifically to differentiate levels of aggressiveness, a crucial aspect for clinical decision-making. Prostate Imaging—Reporting and Data System (PI-RADS) has contributed noteworthily to this aim. Nevertheless, as pointed out by the European Association of Urology (EAU 2020), the PI-RADS still has limitations mainly due to the moderate inter-reader reproducibility of mp-MRI. In recent years, many aspects in the diagnosis of cancer have taken advantage of the use of Artificial Intelligence (AI) such as detection, segmentation of organs and/or lesions, and characterization. Here a focus on AI as a potentially important tool for the aim of standardization and reproducibility in the characterization of PCa by mp-MRI is reported. AI includes methods such as Machine Learning and Deep learning techniques that have shown to be successful in classifying mp-MR images, with similar performances obtained by radiologists. Nevertheless, they perform differently depending on the acquisition system and protocol used. Besides, these methods need a large number of samples that cover most of the variability of the lesion aspect and zone to avoid overfitting. The use of publicly available datasets could improve AI performance to achieve a higher level of generalizability, exploiting large numbers of cases and a big range of variability in the images. Here we explore the promise and the advantages, as well as emphasizing the pitfall and the warnings, outlined in some recent studies that attempted to classify clinically significant PCa and indolent lesions using AI methods. Specifically, we focus on the overfitting issue due to the scarcity of data and the lack of standardization and reproducibility in every step of the mp-MR image acquisition and the classifier implementation. In the end, we point out that a solution can be found in the use of publicly available datasets, whose usage has already been promoted by some important initiatives. Our future perspective is that AI models may become reliable tools for clinicians in PCa diagnosis, reducing inter-observer variability and evaluation time

    Effects of heavy modes on vacuum stability in supersymmetric theories

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    We study the effects induced by heavy fields on the masses of light fields in supersymmetric theories, under the assumption that the heavy mass scale is much higher than the supersymmetry breaking scale. We show that the square-masses of light scalar fields can get two different types of significant corrections when a heavy multiplet is integrated out. The first is an indirect level-repulsion effect, which may arise from heavy chiral multiplets and is always negative. The second is a direct coupling contribution, which may arise from heavy vector multiplets and can have any sign. We then apply these results to the sGoldstino mass and study the implications for the vacuum metastability condition. We find that the correction from heavy chiral multiplets is always negative and tends to compromise vacuum metastability, whereas the contribution from heavy vector multiplets is always positive and tends on the contrary to reinforce it. These two effects are controlled respectively by Yukawa couplings and gauge charges, which mix one heavy and two light fields respectively in the superpotential and the Kahler potential. Finally we also comment on similar effects induced in soft scalar masses when the heavy multiplets couple both to the visible and the hidden sector.Comment: LaTex, 24 pages, no figures; v2 some comments and references adde

    Deep sedation versus minimal sedation during endobronchial ultrasound transbronchial needle aspiration

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    The sedation plays an important role in the endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) procedure. The sedation can be Minimal (anxiolysis), Moderate (conscious sedation) or Deep. The ACCP guidelines suggest that moderate or deep sedation (DS) is an acceptable approach. In fact, several studies compare moderate versus deep sedation, but no study has been carried out to compare deep sedation versus minimal. We carried out a retrospective study to compare the Deep versus Minimal sedation (MiS) in patients undergoing EBUS-TBNA.  The primary end point was the diagnostic accuracy. The secondary end points were adequacy and sensitivity. We evaluated the LN size sampling, procedural time, complications and patient tolerance. Thirty-six patients underwent EBUS-TBNA, 16 under DS and 20 under MiS. The overall diagnostic accuracy for correct diagnosis was 92.9% in DS group and 94.1% in MiS group (p=0.554). Sample adequacy, defined as the percentage of patients with a specific diagnosis by EBUS-TBNA, was 87.5% (14 of 16) and 85% (17 of 20) for the DS group and MiS group, respectively, (p=0.788); the sensitivity was 92.9% in the DS group (95% CI, 73-100%) and 92.9% in the MiS group (95% CI, 77-100%) (p=0.463). There were no major complications in either group. Minor complications were 4 in MiS and 1 in DS (p=0.355).  The patients in the MiS group recalled the procedure more often compared to the other group (p=0.041). The majority of the patients would agree to undergo the same procedure again in the future in both groups (p=0.766).  In our experience EBUS-TBNA performed under MiS has comparable accuracy, adequacy, sensitivity, complications and patient satisfaction to DS, even if the sample was small.  Future prospective multicenter studies are needed to confirm our results

    Raspberry diversification : : impact of the introduction on horticultural systems in Coronda, Santa Fe, Argentina: analysis of a case study

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    El objetivo del presente trabajo fue analizar el impacto micro-econĂłmico que produce la introducciĂłn del cultivo de frambuesa en una pyme hortĂ­cola de Coronda, dedicada esencialmente a la producciĂłn de frutillas.El patrĂłn de diversificaciĂłn actual es escaso, debido principalmente a las limitaciones financieras existentes a nivel predial. Se combina el cultivo de frutilla con otras hortalizas, a contra-ciclo, tales como zapallito, berenjena, choclo, sandĂ­a y melĂłn. Se analizaron los resultados econĂłmicos del ejercicio 2009/2010 de una empresa pyme, estudiada como caso, con una Superficie AgrĂ­cola Útil de 5,5 ha, que implantĂł en el ejercicio evaluado 2 ha de frutilla e introdujo 0,5 ha de frambuesa al esquema productivo, en reemplazo de alguno de los cultivos hortĂ­colas que realizaba. Se obtuvo un Ingreso al capital equivalente a 59.786,unarentabilidadsobreelcapitaltotalde12,95de28,79incrementode258lasituacioˊnsinframbuesa,respectivamente.SemejoraelgradodediversificacioˊnanalizadoatraveˊsdelIˊndicedeEntropıˊayexhibeunaexcelentecomplementariedadtantoenelaspectofinancierocomolaboral.Theaimofthisstudywastoanalyzethemicro−economicimpactoftheintroductionoftheraspberrycropinhorticulturalCorondapymes(SantaFe−Argentina),dedicatedprincipallytothestrawberrycrop.Diversificationpatternislow,mainlyduetofinancialconstraintsatthefarmlevel:itcombinesthemaincropofstrawberrieswithsomevegetablecrops,acounter−season,suchaszucchini,eggplant,sweetcorn,watermelonandcantaloupe.Theeconomicresultsfortheyear2009/2010ofapymewereanalyzed,asacasestudy,withaUsefulAgriculturalSurfaceof5.5haandproduce2haofstrawberrywithdiversehorticulturalcrops.Theintroductionofraspberry(0.5ha)inthesystemresultsanetincomeequivalentto 59.786, una rentabilidad sobre el capital total de 12,95 % y sobre el capital sin tierra de 28,79 %. Estos tres indicadores mostraron un incremento de 258%, 248% y 236% respecto de la situaciĂłn sin frambuesa, respectivamente. Se mejora el grado de diversificaciĂłn analizado a travĂ©s del Índice de EntropĂ­a y exhibe una excelente complementariedad tanto en el aspecto financiero como laboral.The aim of this study was to analyze the micro-economic impact of the introduction of the raspberry crop in horticultural Coronda pymes (Santa Fe-Argentina), dedicated principally to the strawberry crop. Diversification pattern is low, mainly due to financial constraints at the farm level: it combines the main crop of strawberries with some vegetable crops, a counter-season, such as zucchini, eggplant, sweet corn, watermelon and cantaloupe. The economic results for the year 2009/2010 of a pyme were analyzed, as a case study, with a Useful Agricultural Surface of 5.5 ha and produce 2 ha of strawberry with diverse horticultural crops. The introduction of raspberry (0.5 ha) in the system results a net income equivalent to 59,786, a return on total capital of 12.95% and on capital landless 28.79%. These three indicators are 258%, 248%% and 236% higher than the situation without raspberry, respectively. The degree of diversification is enhanced, analyzed by entropy index, and exhibits excellent complementarity in both the financial and labor.Fil: Travadelo, Mariana. Universidad Nacional del LitoralFil: Sordo, MarĂ­a del Huerto. Instituto Nacional de TecnologĂ­a Agropecuaria (Argentina)Fil: Favaro, Juan Carlos. Universidad Nacional del LitoralFil: Pernuzzi, Cristian. Universidad Nacional del LitoralFil: Perren, Ricardo. Universidad Nacional del LitoralFil: Gariglio, Norberto. Universidad Nacional del LitoralFil: Maina, Mariela. Universidad Nacional del LitoralFil: Rossler, Noelia. Universidad Nacional del LitoralFil: Brizi, MarĂ­a C.. Universidad Nacional del LitoralFil: Carboni, AndrĂ©s. Universidad Nacional del Litora

    Minimal Stability in Maximal Supergravity

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    Recently, it has been shown that maximal supergravity allows for non-supersymmetric AdS critical points that are perturbatively stable. We investigate this phenomenon of stability without supersymmetry from the sGoldstino point of view. In particular, we calculate the projection of the mass matrix onto the sGoldstino directions, and derive the necessary conditions for stability. Indeed we find a narrow window allowing for stable SUSY breaking points. As a by-product of our analysis, we find that it seems impossible to perturb supersymmetric critical points into non-supersymmetric ones: there is a minimal amount of SUSY breaking in maximal supergravity.Comment: 27 pages, 1 figure. v2: two typos corrected, published versio

    The lightest scalar in theories with broken supersymmetry

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    We study the scalar mass matrix of general supersymmetric theories with local gauge symmetries, and derive an absolute upper bound on the lightest scalar mass. This bound can be saturated by suitably tuning the superpotential, and its positivity therefore represents a necessary and sufficient condition for the existence of metastable vacua. It is derived by looking at the subspace of all those directions in field space for which an arbitrary supersymmetric mass term is not allowed and scalar masses are controlled by supersymmetry-breaking splitting effects. This subspace includes not only the direction of supersymmetry breaking, but also the directions of gauge symmetry breaking and the lightest scalar is in general a linear combination of fields spanning all these directions. We present explicit results for the simplest case of theories with a single local gauge symmetry. For renormalizable gauge theories, the lightest scalar is a combination of the Goldstino partners and its square mass is always positive. For more general non-linear sigma models, on the other hand, the lightest scalar can involve also the Goldstone partner and its square mass is not always positive.Comment: 30 pages, 3 figures; v2 introduction expanded, paragraph added in section 5 and two references adde

    Metastable de Sitter vacua in N=2 to N=1 truncated supergravity

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    We study the possibility of achieving metastable de Sitter vacua in general N=2 to N=1 truncated supergravities without vector multiplets, and compare with the situations arising in N=2 theories with only hypermultiplets and N=1 theories with only chiral multiplets. In N=2 theories based on a quaternionic manifold and a graviphoton gauging, de Sitter vacua are necessarily unstable, as a result of the peculiar properties of the geometry. In N=1 theories based on a Kahler manifold and a superpotential, de Sitter vacua can instead be metastable provided the geometry satisfies some constraint and the superpotential can be freely adjusted. In N=2 to N=1 truncations, the crucial requirement is then that the tachyon of the mother theory be projected out from the daughter theory, so that the original unstable vacuum is projected to a metastable vacuum. We study the circumstances under which this may happen and derive general constraints for metastability on the geometry and the gauging. We then study in full detail the simplest case of quaternionic manifolds of dimension four with at least one isometry, for which there exists a general parametrization, and study two types of truncations defining Kahler submanifolds of dimension two. As an application, we finally discuss the case of the universal hypermultiplet of N=2 superstrings and its truncations to the dilaton chiral multiplet of N=1 superstrings. We argue that de Sitter vacua in such theories are necessarily unstable in weakly coupled situations, while they can in principle be metastable in strongly coupled regimes.Comment: 40 pages, no figure

    Scalar geometry and masses in Calabi-Yau string models

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    We study the geometry of the scalar manifolds emerging in the no-scale sector of Kahler moduli and matter fields in generic Calabi-Yau string compactifications, and describe its implications on scalar masses. We consider both heterotic and orientifold models and compare their characteristics. We start from a general formula for the Kahler potential as a function of the topological compactification data and study the structure of the curvature tensor. We then determine the conditions for the space to be symmetric and show that whenever this is the case the heterotic and the orientifold models give the same scalar manifold. We finally study the structure of scalar masses in this type of geometries, assuming that a generic superpotential triggers spontaneous supersymmetry breaking. We show in particular that their behavior crucially depends on the parameters controlling the departure of the geometry from the coset situation. We first investigate the average sGoldstino mass in the hidden sector and its sign, and study the implications on vacuum metastability and the mass of the lightest scalar. We next examine the soft scalar masses in the visible sector and their flavor structure, and study the possibility of realizing a mild form of sequestering relying on a global symmetry.Comment: 36 pages, no figure
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