676 research outputs found
Decompositions of Hilbert Spaces, Stability Analysis and Convergence Probabilities for Discrete-Time Quantum Dynamical Semigroups
We investigate convergence properties of discrete-time semigroup quantum
dynamics, including asymptotic stability, probability and speed of convergence
to pure states and subspaces. These properties are of interest in both the
analysis of uncontrolled evolutions and the engineering of controlled dynamics
for quantum information processing. Our results include two Hilbert space
decompositions that allow for deciding the stability of the subspace of
interest and for estimating of the speed of convergence, as well as a formula
to obtain the limit probability distribution for a set of orthogonal invariant
subspaces.Comment: 14 pages, no figures, to appear in Journal of Physics A, 201
Le sette vite del possesso di Savigny
The Treatise on Possession was the most famous Savigny’s work,
published in seven editions from 1803 to 1865. Its history offers a new point of view on
the life and work of the author, on the rise of the Historical School in Germany and on
the genesis of systematics in civil law tradition. A comparison among the editions
confirms that the two phases of Savigny production were rooted in a common
methodological program. The discovery of the Gaio Institutions had a minimal
consequence on the contents of the work. However, despite the national and
international reception of the work, it did not leave significative traces in the future
legislation and doctrine. Nevertheless, Savigny’s production method and categories
became recognized models of the legal scienc
Focal Epilepsy Associated with Glioneuronal Tumors
Glioneuronal tumors are an increasingly recognized cause of partial seizures that occur primarily in children and young adults. Focal epilepsy associated with glioneuronal tumors is often resistant to pharmacological treatment. The cellular mechanisms underlying the epileptogenicity of glioneuronal tumors remain largely unknown. The involved mechanisms are certain to be multifactorial and depend on specific tumor histology, integrity of the blood-brain barrier, characteristics of the peritumoral environment, circuit abnormalities, or cellular and molecular defects. Glioneuronal tumors presenting with epilepsy were observed to have relatively benign biological behavior. The completeness of the tumor resection is of paramount importance in avoiding tumor progression and malignant transformation, which are rare in cases of epileptogenic glioneuronal tumors.
An evolving understanding of the various mechanisms of tumor-related epileptogenicity may also lead to a more defined surgical objective and effective therapeutic strategies, including antiepileptogenic treatments, to prevent epilepsy in at-risk patients
Energizing Sustainable Agriculture: Advances in Greenhouse Heating through Microwave-Based Technologies
For the agricultural sector to develop sustainably in the future, progress toward more
environmentally friendly technologies and methods is crucial. It is necessary to increase output while
reducing the demand for energy, agrochemicals, and water resources. Although greenhouses can be utilized successfully for this purpose, significant technical advancements are required, especially when it comes to heating, to lower the use of fossil fuels and boost energy efficiency. Microwaves
can warm plants without heating the entire greenhouse volume, which takes a significant amount of
energy to compensate for heat loss in the outdoor environment. In this paper, through a thorough examination of the state of the art, a general overview of novel greenhouse heating systems based on radiation is reported. First, the strengths and weaknesses of microwave heating are discussed,
and finally, the use of microwaves for soil sterilization is examined. All outcomes suggest these irradiation-based technologies can contribute significantly to energetically sustainable agriculture; moreover, they can be used to increase plant comfor
Folding transition of the triangular lattice in a discrete three--dimensional space
A vertex model introduced by M. Bowick, P. Di Francesco, O. Golinelli, and E.
Guitter (cond-mat/9502063) describing the folding of the triangular lattice
onto the face centered cubic lattice has been studied in the hexagon
approximation of the cluster variation method. The model describes the
behaviour of a polymerized membrane in a discrete three--dimensional space. We
have introduced a curvature energy and a symmetry breaking field and studied
the phase diagram of the resulting model. By varying the curvature energy
parameter, a first-order transition has been found between a flat and a folded
phase for any value of the symmetry breaking field.Comment: 11 pages, latex file, 2 postscript figure
Molecular mechanisms of the acute kidney injury to chronic kidney disease transition: An updated view
Increasing evidence has demonstrated the bidirectional link between acute kidney injury (AKI) and chronic kidney disease (CKD) such that, in the clinical setting, the new concept of a unified syndrome has been proposed. The pathophysiological reasons, along with the cellular and molecular mechanisms, behind the ability of a single, acute, apparently self-limiting event to drive chronic kidney disease progression are yet to be explained. This acute injury could promote progression to chronic disease through different pathways involving the endothelium, the inflammatory response and the development of fibrosis. The interplay among endothelial cells, macrophages and other immune cells, pericytes and fibroblasts often converge in the tubular epithelial cells that play a central role. Recent evidence has strengthened this concept by demonstrating that injured tubules respond to acute tubular necrosis through two main mechanisms: The polyploidization of tubular cells and the proliferation of a small population of self-renewing renal progenitors. This alternative pathophysiological interpretation could better characterize functional recovery after AKI
Acrylamide in Baby Foods: A Probabilistic Exposure Assessment
Acrylamide (also known as 2-propenamide) (AA) is a toxicant that develops in food during high-temperature cooking, and its occurrence is common in biscuits and baked snacks. AA is known for its in vivo neurotoxic and carcinogenic effects, and it is considered a potential carcinogen for humans. Infants may be exposed to AA as early as during weaning through baked food such as biscuits. This study set out to ascertain the concentration of AA in food products intended for infants to assess the dietary exposure to this food contaminant. AA levels were determined through GC/MS and bromination, and dietary exposure was evaluated by a probabilistic method based on Monte Carlo simulation. The results showed that the probability of a carcinogenic exposure is 94%, 92%, and 87%, respectively, for 6-, 12-, and 18-months infants, suggesting the need to delay the introduction of baked products in the diet of weaned infants. It should be noted, however, that these conclusions were drawn considering the biscuits as the primary source of exposure
Ameliorating a Complex Urban Ecosystem Through Instrumental Use of Softscape Buffers: Proposal for a Green Infrastructure Network in the Metropolitan Area of Naples
Green Infrastructure (GI) definition, deriving from the United States green infrastructure
for hydro-geological rebalancing through imitating the nature stormwater management,
was consolidated in Europe by GI Planning Guide. Nowadays GI can be considered
a valid and meaningful approach for ameliorating urban complex ecosystems, and
could also be considered as mitigation action of land consumption, according to the
guidelines on the soil sealing of the European Commission (2012). The metropolitan
area of Naples located in south Italy is characterized by an unauthorized and chaotic
urban development. The land-use map reported an average of 30% of urbanization in
the metropolitan area, rising up to 50–60% and as high as 98% in the north core area of
the city. This high level of urbanization is directly related to the habitat fragmentation. The
National Biodiversity Conservation Strategy defines several challenges and targets to
counteract the biodiversity loss in Italy, identifying urban areas as places exposed to the
greatest pressures on ecosystems. Therefore, the integration of different policies limiting
habitat fragmentation, heat island effect and natural soil hydro-geological degradation
into spatial planning, especially through green corridors and ecosystem enhancement
in urban areas is an urgent need for the society. Spatial planning has to be renewed
in metropolitan areas, where threats and weaknesses to biodiversity conservation are
stronger than in any other place, according to the Law n. 56/2014, (Gazzetta Ufficiale
della Repubblica Italiana, 2014) committing metropolitan cities to the enactment of
General Territorial Plan. In the current paper, we aim at designing an ecological network
for the metropolitan area of Naples one of the biggest city of southern Italy. The analyses
include the adopted methodological procedure, i.e., ecological network analysis and
design, and the introductory elements of a spatial analysis on a pilot ecological network
of several patches. Finally, the paper illustrates the network analysis conceived as a
monitoring system and also in future perspective, as a planning support system
Spatial distribution and partitioning of polychlorinated biphenyl and organochlorine pesticide in water and sediment from Sarno River and Estuary, Southern Italy
The Sarno River is nicknamed "the most polluted river in Europe". The main goal of this study is to enhance our knowledge on the Sarno River water and sediment quality and on its environmental impact on the gulf of Naples (Tyrrhenian Sea, Central Mediterranean Sea) in order to become a useful assessment tool for the regional administrations. For these reasons, 32 selected polychlorinated biphenyls (PCBs) and aldrin, α-BHC, β-BHC, δ-BHC, γ-BHC (lindane), 4,4′-DDD, 4,4′-DDE, 4,4′-DDT, dieldrin, endosulfan I, endosulfan II, endosulfan sulphate, endrin, endrin aldehyde, heptachlor, heptachlor epoxide (isomer B) and methoxychlor were determined in the water dissolved phase (DP), suspended particulate matter (SPM) and sediments. Total concentrations of PCBs ranged from 1.4 to 24.9 ng L-1 in water (sum of DP and SPM) and from 1.01 to 42.54 ng g-1 in sediment samples. The concentrations of total organochlorine pesticides (OCPs) obtained in water (sum of DP and SPM) ranged from 0.54 to 7.32 ng L-1 and from 0.08 to 5.99 ng g-1 in sediment samples. Contaminant discharges of PCBs and OCPs into the sea were calculated in about 1,247 g day-1 (948 g day-1 of PCBs and 326 g day-1 of OCPs), showing that this river should account as one of the main contribution sources of PCBs and OCPs to the Tyrrhenian Sea
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