800 research outputs found
A characterization of Schauder frames which are near-Schauder bases
A basic problem of interest in connection with the study of Schauder frames
in Banach spaces is that of characterizing those Schauder frames which can
essentially be regarded as Schauder bases. In this paper, we give a solution to
this problem using the notion of the minimal-associated sequence spaces and the
minimal-associated reconstruction operators for Schauder frames. We prove that
a Schauder frame is a near-Schauder basis if and only if the kernel of the
minimal-associated reconstruction operator contains no copy of . In
particular, a Schauder frame of a Banach space with no copy of is a
near-Schauder basis if and only if the minimal-associated sequence space
contains no copy of . In these cases, the minimal-associated
reconstruction operator has a finite dimensional kernel and the dimension of
the kernel is exactly the excess of the near-Schauder basis. Using these
results, we make related applications on Besselian frames and near-Riesz bases.Comment: 12 page
On sequence spaces for Fr\'echet frames
We analyze the construction of a sequence space , resp. a
sequence of sequence spaces, in order to have as a
-frame or Banach frame for a Banach space , resp.
pre--frame or -frame for a Fr\'echet space , where is a sequence of Banach spaces
Addressing COVID-19 Communication and Management by a Systems Thinking Approach
A systemic stock-flow diagram is proposed for the communication and management of health services and strategies concerning the COVID-19 epidemic. The possible role of government interventions in activating systemic leverage points is also addressed. The presented approach, based on Systems Thinking, can create the basis for creating an analytical simulator of the disease spread, and at the same time the diagram can constitute a powerful tool for improving the quality of information for both policy-makers and the general public in situations of epidemics
Intrinsic Environmental Vulnerability as Shallow Landslide Susceptibility in Environmental Impact Assessment
This work investigated the susceptibility factors that trigger shallow landslides. In particular,
the objective of the research was the implementation of a method to determine the relevant factors that
can trigger shallow landslide events. However, with respect to the existing methods, the integration
with historical datasets and the inclusion of spatial factors displaying dynamics in the same characteristic
timescales were specific features of the developed tool. The study area included the watersheds of
the Sessera and Strona rivers in the alpine area of the Province of Biella (Piedmont, NW Italy).
The method was developed and tested from two sub-datasets derived from an integrated dataset
that referred to an intense event, involving the same area, that occurred in 1968 (2\u20133 November).
This allowed the implementation of an integrated representation of landslides\u2019 predisposing factors
and the identification and classification in dierent groups of the areas susceptible to geo-hydrological
instability processes. The previously existing databases were verified and integrated into a geographic
information system (GIS) environment, giving a potentially sharable source of information for
planning purposes. The obtained maps represent a metric of one of the possible intrinsic environmental
vulnerability factors for the area under study. Consequently, this method can represent a future
instrument for determining the intrinsic environmental vulnerability dependent on landslides within
an environmental impact assessment (EIA), as required by the most recent European regulation on EIA.
Moreover, the shared information can be used to implement informed policy and planning processes,
based on a bottom-up approach. In particular, the availability online of landslide susceptibility
maps could support the generation of augmented information\u2014useful for both local administrators
and planners as well as for stakeholders willing to implement specific projects or infrastructure in
vulnerable areas, such as mountain
Effect of pretreatment with immune serum on murine sarcoma virus (Moloney) tumour induction and growth.
Regressor serum from MSV-M-infected mice markedly reduced MSV-M oncogenesis when administered i.p. (0-1 ml/mouse) as much as 30 days before i.m. MSV-M infection in adult BALB/c mice. The regressor serum activity appeared to be directly dependent on the amount of IgG, as shown by: (1) inactivity of sera which have low virus-neutralizing antibody content; (2) high effectiveness only of the IgG serum fraction; (3) inactivity of regressor serum incubated with anti-mouse gamma-globulin serum. The regressor serum activity was specific and could not be ascribed to interferon or interferon-inducing factors, antigen-antibody complexes or free antigen. The activity was not suppressed by sublethal irradiation (380 rad) of recipient mice. These results suggest that the activity of regressor serum administered before MSV-M infection is mediated through sensitization of host cells which are not radiosensitive
The multiple vehicle balancing problem
This paper deals with the multiple vehicle balancing problem (MVBP). Given a fleet of vehicles of limited capacity, a set of vertices with initial and target inventory levels and a distribution network, the MVBP requires to design a set of routes along with pickup and delivery operations such that inventory is redistributed among the vertices without exceeding capacities, and routing costs are minimized. The MVBP is NP\u2010hard, generalizing several problems in transportation, and arising in bike\u2010sharing systems. Using theoretical properties of the problem, we propose an integer linear programming formulation and introduce strengthening valid inequalities. Lower bounds are computed by column generation embedding an ad\u2010hoc pricing algorithm, while upper bounds are obtained by a memetic algorithm that separate routing from pickup and delivery operations. We combine these bounding routines in both exact and matheuristic algorithms, obtaining proven optimal solutions for MVBP instances with up to 25 stations
Topography of the Dolomites modulates range dynamics of narrow endemic plants under climate change
open9noClimate change is expected to threaten endemic plants in the Alps. In this context, the factors that may modulate species responses are rarely investigated at a local scale. We analyzed eight alpine narrow endemics of the Dolomites (southeastern Alps) under different predicted climate change scenarios at fine spatial resolutions. We tested possible differences in elevation, topographic heterogeneity and velocity of climate change among areas of gained, lost, or stable climatic habitat. The negative impact of climate change ranged from moderate to severe, depending on scenario and species. Generally, range loss occurred at the lowest elevations, while gained and stable areas were located at highest elevations. For six of the species, climate change velocity had higher values in stable and gained areas than in lost ones. Our findings support the role of topographic heterogeneity in maintaining climatic microrefugia, however, the peculiar topography of the Dolomites, characterized by high altitude plateaus, resulted in high climate change velocity in areas of projected future climatic suitability. Our study supports the usefulness of multiple predictors of spatio-temporal range dynamics for regional climate-adapted management and eventual assisted colonization planning to not overlook or overestimate the potential impact of climate change locally.openRota F.; Casazza G.; Genova G.; Midolo G.; Prosser F.; Bertolli A.; Wilhalm T.; Nascimbene J.; Wellstein C.Rota, F.; Casazza, G.; Genova, G.; Midolo, G.; Prosser, F.; Bertolli, A.; Wilhalm, T.; Nascimbene, J.; Wellstein, C
Weighted complex projective 2-designs from bases: optimal state determination by orthogonal measurements
We introduce the problem of constructing weighted complex projective
2-designs from the union of a family of orthonormal bases. If the weight
remains constant across elements of the same basis, then such designs can be
interpreted as generalizations of complete sets of mutually unbiased bases,
being equivalent whenever the design is composed of d+1 bases in dimension d.
We show that, for the purpose of quantum state determination, these designs
specify an optimal collection of orthogonal measurements. Using highly
nonlinear functions on abelian groups, we construct explicit examples from d+2
orthonormal bases whenever d+1 is a prime power, covering dimensions d=6, 10,
and 12, for example, where no complete sets of mutually unbiased bases have
thus far been found.Comment: 28 pages, to appear in J. Math. Phy
A new approach for the recovery of polyphenols from Arthrospira platensis: advancement of green process through high pressure/temperature extraction
The cyanobacterium Arthrospira (Spirulina) platensis was used as raw material for the recovery of polyphenols by the high temperature/high pressure extraction process, to be used as ingrediet for fuctional foods preparation
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