867 research outputs found
Historical roots and the evolving science of forest management under a systemic perspective
In recent history, both a growing awareness of how scientific and societal uncertainty impacts management decisions and of the intrinsic value of nature have suggested new approaches to forest management, with a growing debate in forest science over the need for a paradigmatic shift from the classic conventional world view, based on determinism, predictability, and output-oriented management, towards a world view that has roots in complex adaptive systems theory and is consistent with a nature-based ethic. A conceptual framework under this context is provided by systemic silviculture. In this discussion, we analyze how this approach can be linked to three fundamental moments of the history of forestry and forest science: the Dauerwald theory, Gurnaud's control method, and the origins of environmental ethics. Relationships with the recent history of forest management science and current research perspectives are also highlighted.4n
Superconductivity in Sr2RuO4-Sr3Ru2O7 eutectic crystals
Superconducting behavior has been observed in the Sr2RuO4-Sr3Ru2O7 eutectic
system as grown by the flux-feeding floating zone technique. A supercurrent
flows across a single interface between Sr2RuO4 and Sr3Ru2O7 areas at distances
that are far beyond those expected in a conventional proximity scenario. The
current-voltage characteristics within the Sr3Ru2O7 macrodomain, as extracted
from the eutectic, exhibit signatures of superconductivity in the bilayered
ruthenate. Detailed microstructural, morphological and compositional analyses
address issues on the concentration and the size of Sr2RuO4 inclusions within
the Sr3Ru2O7 matrix. We speculate on the possibility of inhomogeneous
superconductivity in the eutectic Sr3Ru2O7 and exotic pairing induced by the
Sr2RuO4 inclusions.Comment: Pages 4, figures 3, submitted to Phys. Rev. Let
Modeling of shock absorption in athletics track surfaces
In this work, the possibility of predicting the force reduction (FR) characterizing the shock absorption capability of track surfaces by finite element modeling was investigated. The mechanical responses of a typical sport surface and of a reference material were characterized by quasi-static uniaxial compression experiments and fitted by Neo-Hookean and Mooney–Rivlin’s hyperelastic models to select the more appropriate one. Furthermore, in order to examine the materials behavior at strain rates typical of athletics applications, the rate dependence of the constitutive parameters was investigated. A finite element model, taking into consideration the post-impact nonlinear dynamics of the track surface and of the system (track surface + artificial athlete), was developed and validated through comparison with the results of FR tests. The simulations showed a very good agreement with the experiments and allowed to interpret the experimentally observed combined effect of track thickness and material intrinsic properties on the overall surface behavior
Entanglement of fields in coupled-cavities: effects of pumping and fluctuations
A system of two coupled cavities is studied in the context of bipartite,
continuous variable entanglement. One of the cavities is pumped by an external
classical source that is coupled quadratically, to the cavity field. Dynamics
of entanglement, quantified by covariance measure [Dodonov {\it et al}, Phys.
Lett A {\bf 296}, (2002) 73], in the presence of cavity-cavity coupling and
external pumping is investigated. The importance of tailoring the coupling
between the cavities is brought out by studying the effects of pump
fluctuations on the entanglement.Comment: 20 pages; 6 figure
High Tc superconductors for plasmonics and metamaterials fabrication: A preliminary normal state optical characterisation of Nd123 and Gd1212
Evaluation of Drug Interactions in Patients Treated with DAAs for Hepatitis C Therapy with Comorbidities and Cardiovascular Issues—A Delphi Consensus Project
Orally administered direct-acting antivirals (DAAs) have dramatically changed the possibility of curing HCV (hepatitis C virus) infection, with the two principal HCV regimens based on the combination of glecaprevir + pibrentasvir (GLE-PIB) and sofosbuvir + velpatasvir (SOF-VEL). A combination of drugs containing NS3/4A protease inhibitors, as well as the fact that almost all HCV patients can be treated at present, may expose patients to a higher rate of drug–drug interactions (DDIs). The hepatitis C treatment recommendations from the EASL (European Association for the Study of the Liver) state that, prior to starting treatment with a DAA, a detailed drug history should be taken; yet, the decision on managing the potential DDIs is not always clear. For this reason, a group of Italian cardiologists and hepatologists promoted a survey among colleagues to assess the controversial issues when treating patients with chronic hepatitis C taking concomitant cardiovascular drugs, aiming to reach a consensus on the best practice to apply when treating a patient with chronic hepatitis C who is taking concomitant drugs for cardiovascular diseases. Two consecutive questionnaires were proposed between June and July 2022 to a qualitative Expert Panel (EP) of 14 gastroenterologists, infectologists, hepatologists, and internists, with statistical analyses performed on 100% of the responses for both questionnaires. Agreement among experts was assessed following the Delphi method as developed by the RAND Corporation. The interviewed experts consider DDIs a critical clinical problem to be evaluated in HCV patients. Therefore, dose changes, drug substitution, and discontinuation of concomitant cardiovascular drugs should be discouraged, even if planned for a relatively short period. Since oral DAAs have different DDIs profiles, hepatologists should prefer the antiviral DAA combination presenting the lowest instance of potential interactions
microRNAs and Inflammatory Immune Response in SARS-CoV-2 Infection: A Narrative Review
The current SARS-CoV-2 pandemic has emerged as an international challenge with strong medical and socioeconomic impact. The spectrum of clinical manifestations of SARS-CoV-2 is wide, covering asymptomatic or mild cases up to severe and life-threatening complications. Critical courses of SARS-CoV-2 infection are thought to be driven by the so-called “cytokine storm”, derived from an excessive immune response that induces the release of proinflammatory cytokines and chemokines. In recent years, non-coding RNAs (ncRNAs) emerged as potential diagnostic and therapeutic biomarkers in both inflammatory and infectious diseases. Therefore, the identification of SARS-CoV-2 miRNAs and host miRNAs is an important research topic, investigating the host–virus crosstalk in COVID-19 infection, trying to answer the pressing question of whether miRNA-based therapeutics can be employed to tackle SARS-CoV-2 complications. In this review, we aimed to directly address ncRNA role in SARS-CoV-2-immune system crosstalk upon COVID-19 infection, particularly focusing on inflammatory pathways and cytokine storm syndromes
Redescription of Cardiosporidium cionae (Van Gaver and Stephan, 1907) (Apicomplexa: Piroplasmida), a plasmodial parassite of ascidian haemocytes
Cardiosporidium cionae (Apicomplexa), from the ascidian Ciona intestinalis L., is redescribed with novel ultrastructural, phylogenetic and prevalence data. Ultrastructural analysis of specimens of C. intestinalis collected from the Gulf of Naples showed sporonts and plasmodia of C. cionae within the host pericardial body. Several merogonic stages and free merozoites were found in the pericardial body, together with sexual stages. All stages showed typical apicomplexan cell organelles, i.e. apicoplasts, rhoptries and subpellicular microtubules. Merogonic stages of C. cionae were also produced inside haemocytes. A fragment of the rSSU gene of C. cionae was amplified by PCR using DNA extracted from the pericardial bodies. The amplified product showed closest affinity with other apicomplexan representatives and a 66 bp unique insertion, specific for C. cionae, at position 1644. Neighbour-joining phylogenetic analysis placed C. cionae in a clade with other piroplasm genera, including Cytauxzoon, Babesia and Theileria spp. The parasite was found in different populations of C. intestinalis with highest prevalence in October–November. Ultrastructural and DNA data showed that the organism, described in 1907 from the same host but not illustrated in detail, is a member of a novel marine apicomplexan radiation of tunicate parasites
Energy-efficient data representation and routing for wireless sensor networks based on a distributed wavelet compression algorithm
The southernmost beech (Fagus sylvatica) forests of Europe (Mount Etna, Italy): ecology, structural stand-type diversity and management implications
The southernmost European beech forests are located in the upper forest vegetation belt on Mount Etna volcano. Their standstructural
patterns were analysed to assess the effects of the site-ecological factors and previous management practices on the
forest structure. Five main structural-silvicultural types were identified among the main beech forest types: coppice, highmountain
coppice (HMCo), high forest, coppice in conversion to high-forest and non-formal stand. A detailed standstructural
analysis was carried out through measured dendrometric parameters and derived structural characters linked to
both the horizontal and the vertical profiles. Plant regeneration processes were also assessed, and several biodiversity
indicators were calculated. The collected data indicate a high variability of beech stand structures in relation to the
heterogeneity of the site-ecological characteristics as well as to the effects of both natural and anthropic disturbance factors.
The occurrence of particular stand structures along the altitude gradient on Mount Etna is evident. It is especially visible in
the multi-stemmed HMCos in relation to the changing, and increasingly limiting, ecological factors, although at higher
altitudes historical anthropic actions (felling) also have had an influence. Inside the Mediterranean area, these stands highlight
their ecological marginality, in terms of both latitude and altitude, especially regarding current climate change processes
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