84 research outputs found
Psychological outcomes of local heritage engagement: participation in community archeological excavations increases wellâbeing, selfâefficacy, and perceived community support
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
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
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 ImagingâReporting 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
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
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
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 Ătil 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, 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, Andrés.
Universidad Nacional del Litora
Minimal Stability in Maximal Supergravity
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
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
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
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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