4,386 research outputs found
Le briofite della Grotta dell\u2019Orso (33-7VG, Carso triestino, NE Italia)
Vengono presentati i risultati di uno studio sulla flora briologica della Grotta dell\u2019Orso (33-7VG), situata sul Carso triestino. Sono state rinvenute 42 specie di briofite (33 specie di muschi e 9 epatiche); per ogni specie sono indicati l\u2019elemento corologico, la distribuzione nell\u2019area e note ecologico-stazionali. Aspetti floristici, biogeografici e conservazionistici della componente briologica dell\u2019area vengono discussi. Viene riportata una nuova specie per la Regione Friuli Venezia Giulia, l\u2019epatica Cololejeunea rossettiana; 2 altre specie di muschi sono segnalate come nuove per il Carso. La flora briologica aggiornata della cavit\ue0 comprende 46 specie
Finite-size scaling as a way to probe near-criticality in natural swarms
Collective behaviour in biological systems is often accompanied by strong
correlations. The question has therefore arisen of whether correlation is
amplified by the vicinity to some critical point in the parameters space.
Biological systems, though, are typically quite far from the thermodynamic
limit, so that the value of the control parameter at which correlation and
susceptibility peak depend on size. Hence, a system would need to readjust its
control parameter according to its size in order to be maximally correlated.
This readjustment, though, has never been observed experimentally. By gathering
three-dimensional data on swarms of midges in the field we find that swarms
tune their control parameter and size so as to maintain a scaling behaviour of
the correlation function. As a consequence, correlation length and
susceptibility scale with the system's size and swarms exhibit a near-maximal
degree of correlation at all sizes.Comment: Selected for Viewpoint in Physics; PRL Editor's Suggestio
Collective behaviour without collective order in wild swarms of midges
Collective behaviour is a widespread phenomenon in biology, cutting through a
huge span of scales, from cell colonies up to bird flocks and fish schools. The
most prominent trait of collective behaviour is the emergence of global order:
individuals synchronize their states, giving the stunning impression that the
group behaves as one. In many biological systems, though, it is unclear whether
global order is present. A paradigmatic case is that of insect swarms, whose
erratic movements seem to suggest that group formation is a mere epiphenomenon
of the independent interaction of each individual with an external landmark. In
these cases, whether or not the group behaves truly collectively is debated.
Here, we experimentally study swarms of midges in the field and measure how
much the change of direction of one midge affects that of other individuals. We
discover that, despite the lack of collective order, swarms display very strong
correlations, totally incompatible with models of noninteracting particles. We
find that correlation increases sharply with the swarm's density, indicating
that the interaction between midges is based on a metric perception mechanism.
By means of numerical simulations we demonstrate that such growing correlation
is typical of a system close to an ordering transition. Our findings suggest
that correlation, rather than order, is the true hallmark of collective
behaviour in biological systems.Comment: The original version has been split into two parts. This first part
focuses on order vs. correlation. The second part, about finite-size scaling,
will be included in a separate paper. 15 pages, 6 figures, 1 table, 5 video
High overtones of Dirac perturbations of a Schwarzschild black hole
Using the Frobenius method, we find high overtones of the Dirac quasinormal
spectrum for the Schwarzschild black hole. At high overtones, the spacing for
imaginary part of is equidistant and equals to
, ( is the black hole mass), which
is twice less than that for fields of integer spin. At high overtones, the real
part of goes to zero. This supports the suggestion that the
expected correspondence between quasinormal modes and Barbero-Immirzi parameter
in Loop Quantum Gravity is just a numerical coincidence.Comment: 5 pages, Latex, 3 figures, Physical Review D.,at pres
Left ventricular mass increase is associated with cognitive decline and dementia in the elderly independently of blood pressure
Aims Left ventricular (LV) mass increase is considered part of composite target organ damage in hypertension and an independent risk factor for cardiovascular (CV) events. This study was designed to explore whether left ventricular mass index (LVMI) is associated with cognitive decline and dementia in elderly subjects, independently of blood pressure (BP) levels. Methods and results Four hundred subjects (mean age 79 ± 6 years) were studied. Left ventricular mass was measured echocardiographically in accordance with American Society of Echocardiography and normalized for body height to the 2.7 (LVMI). Global cognitive function was evaluated with the mini-mental state examination (MMSE) (maximum score 30). Dementia was defined as an MMSE score <21. Arterial stiffness was evaluated as carotid–femoral pulse wave velocity by Complior®. Prevalence of hypertension was 70% and diabetes mellitus was diagnosed in 25%. No significant differences in traditional CV risk factors were observed across LVMI quartiles. Mini-mental state examination showed an inverse trend across LVMI quartiles (the higher the LVMI, the lower the MMSE, P for trend <0.05); systolic and diastolic BP levels were not different across LVMI quartiles. In multivariable logistic regression models, including age, sex, BP levels, and use of antihypertensive drugs as covariates, the highest LVMI was found to be independently associated with a two-fold higher likelihood of having dementia. The association persisted significant even after adjustment for arterial stiffness. Conclusion In elderly subjects, LVMI is associated with a progressive cognitive decline. This association is independent of BP levels and/or large artery stiffness
Emerging cross-disciplinary profiles: The Geomatic Epidemiologist
Abstract
Issue
Geographic information systems (GIS) and remote sensing technologies are increasingly used in Public Health epidemiology, showing a great potential in anticipating and responding to actual and future challenges for the public health system and in improving health services' excellence. According to the evidences collected within a wide meta-research carried on of relevant literature ("GIS geographic information system" and "GIS geographic information system and training" on Pubmed; "epidemiologist use of GIS and training" and "epidemiologist use of gis" on Google Scholar),GIS and new sensing technologies are mostly used to: map air and water pollution, map diseases prevalence, predict infection diseases and vector-spread diseases in big areas, study health service coverage and preparedness in emergencies, map cities and study urban health, study climate changes for decision making.
Description of the Problem
Specific skills and training are required to address the use of GIS and new sensing technologies.The specific aim of our study is to identify the professional profile of a new figure, called 'Geomatic Epidemiologist' and to define its professional and educational standards, as well as the relevant training programs.
Results
Data collection and analysis of INAPP and ESCO databases about existing professional profiles (starting from 2016) has allowed drafting a first qualification schema and profile. The profile has been defined according to the 4C model (elaborated by Univaq) distinguishing between Hard Skills (technical knowledge and skills),Soft Skills (cognitive, individual and social) and interpersonal behaviors.
Conclusions
Profile will be validated with relevant stakeholders and Public Health professionals in order to deepen the understanding of the main competences required to study health issues with GIS and related technologies; to this extent, a questionnaire has been elaborated to evaluate relevance, frequency and complexity of each component of the profile
Key messages
Developing cross-disciplinary profiles, (i.e. the Geomatic Epidemiologist) integrating clusters of competences (holistic approach). Public health research challenges and excellence
PET-Derived Radiomics and Artificial Intelligence in Breast Cancer: A Systematic Review
Breast cancer (BC) is a heterogeneous malignancy that still represents the second cause of cancer-related death among women worldwide. Due to the heterogeneity of BC, the correct identification of valuable biomarkers able to predict tumor biology and the best treatment approaches are still far from clear. Although molecular imaging with positron emission tomography/computed tomography (PET/CT) has improved the characterization of BC, these methods are not free from drawbacks. In recent years, radiomics and artificial intelligence (AI) have been playing an important role in the detection of several features normally unseen by the human eye in medical images. The present review provides a summary of the current status of radiomics and AI in different clinical settings of BC. A systematic search of PubMed, Web of Science and Scopus was conducted, including all articles published in English that explored radiomics and AI analyses of PET/CT images in BC. Several studies have demonstrated the potential role of such new features for the staging and prognosis as well as the assessment of biological characteristics. Radiomics and AI features appear to be promising in different clinical settings of BC, although larger prospective trials are needed to confirm and to standardize this evidence
Gas6/TAM system: A key modulator of the interplay between inflammation and fibrosis
Fibrosis is the result of an overly abundant deposition of extracellular matrix (ECM) due to the fact of repetitive tissue injuries and/or dysregulation of the repair process. Fibrogenesis is a pathogenetic phenomenon which is involved in different chronic human diseases, accounting for a high burden of morbidity and mortality. Despite being triggered by different causative factors, fibrogenesis follows common pathways, the knowledge of which is, however, still unsatisfactory. This represents a significant limit for the development of effective antifibrotic drugs. In the present paper, we aimed to review the current evidence regarding the potential role played in fibrogenesis by growth arrest-specific 6 (Gas6) and its receptors Tyro3 protein tyrosine kinase (Tyro3), Axl receptor tyrosine kinase (Axl), and Mer tyrosine kinase protooncogene (MerTK) (TAM). Moreover, we aimed to review data about the pathogenetic role of this system in the development of different human diseases characterized by fibrosis. Finally, we aimed to explore the potential implications of these findings in diagnosis and treatment
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