567 research outputs found
Weakly Z symmetric manifolds
We introduce a new kind of Riemannian manifold that includes weakly-, pseudo-
and pseudo projective- Ricci symmetric manifolds. The manifold is defined
through a generalization of the so called Z tensor; it is named "weakly Z
symmetric" and denoted by (WZS)_n. If the Z tensor is singular we give
conditions for the existence of a proper concircular vector. For non singular Z
tensor, we study the closedness property of the associated covectors and give
sufficient conditions for the existence of a proper concircular vector in the
conformally harmonic case, and the general form of the Ricci tensor. For
conformally flat (WZS)_n manifolds, we derive the local form of the metric
tensor.Comment: 13 page
Static Safety for an Actor Dedicated Process Calculus by Abstract Interpretation
The actor model eases the definition of concurrent programs with non uniform
behaviors. Static analysis of such a model was previously done in a data-flow
oriented way, with type systems. This approach was based on constraint set
resolution and was not able to deal with precise properties for communications
of behaviors. We present here a new approach, control-flow oriented, based on
the abstract interpretation framework, able to deal with communication of
behaviors. Within our new analyses, we are able to verify most of the previous
properties we observed as well as new ones, principally based on occurrence
counting
A Logical Verification Methodology for Service-Oriented Computing
We introduce a logical verification methodology for checking behavioural properties of service-oriented computing systems. Service properties are described by means of SocL, a branching-time temporal logic that we have specifically designed to express in an effective way distinctive aspects of services, such as, e.g., acceptance of a request, provision of a response, and correlation among service requests and responses. Our approach allows service properties to be expressed in such a way that
they can be independent of service domains and specifications. We show an instantiation of our general methodology that uses the formal language COWS to conveniently specify services and the expressly developed software tool CMC to assist the user in the task of verifying SocL formulae over service specifications. We demonstrate feasibility and effectiveness of our methodology by means of the specification and the analysis of a case study in the automotive domain
Nitroproteínas implicadas en la maduración de frutos y en el estrés por baja temperatura en plantas de pimiento (Capsicum annuum L)
Comunicaciones a congreso
Análisis de la nitración fisiológica de proteínas en órganos de plantas de guisante (Pisum sativum L) durante su desarrollo y senescencia
Comunicaciones a congreso
Impact of Community-Based Larviciding on the Prevalence of Malaria Infection in Dar es Salaam, Tanzania.
The use of larval source management is not prioritized by contemporary malaria control programs in sub-Saharan Africa despite historical success. Larviciding, in particular, could be effective in urban areas where transmission is focal and accessibility to Anopheles breeding habitats is generally easier than in rural settings. The objective of this study is to assess the effectiveness of a community-based microbial larviciding intervention to reduce the prevalence of malaria infection in Dar es Salaam, United Republic of Tanzania. Larviciding was implemented in 3 out of 15 targeted wards of Dar es Salaam in 2006 after two years of baseline data collection. This intervention was subsequently scaled up to 9 wards a year later, and to all 15 targeted wards in 2008. Continuous randomized cluster sampling of malaria prevalence and socio-demographic characteristics was carried out during 6 survey rounds (2004-2008), which included both cross-sectional and longitudinal data (N = 64,537). Bayesian random effects logistic regression models were used to quantify the effect of the intervention on malaria prevalence at the individual level. Effect size estimates suggest a significant protective effect of the larviciding intervention. After adjustment for confounders, the odds of individuals living in areas treated with larviciding being infected with malaria were 21% lower (Odds Ratio = 0.79; 95% Credible Intervals: 0.66-0.93) than those who lived in areas not treated. The larviciding intervention was most effective during dry seasons and had synergistic effects with other protective measures such as use of insecticide-treated bed nets and house proofing (i.e., complete ceiling or window screens). A large-scale community-based larviciding intervention significantly reduced the prevalence of malaria infection in urban Dar es Salaam
Endogenous Biosynthesis of S-Nitrosoglutathione From Nitro-Fatty Acids in Plants
Nitro-fatty acids (NO2-FAs) are novel molecules resulting from the interaction of
unsaturated fatty acids and nitric oxide (NO) or NO-related molecules. In plants, it has
recently been described that NO2-FAs trigger an antioxidant and a defence response
against stressful situations. Among the properties of NO2-FAs highlight the ability to
release NO therefore modulating specific protein targets through post-translational
modifications (NO-PTMs). Thus, based on the capacity of NO2-FAs to act as
physiological NO donors and using high-accuracy mass-spectrometric approaches,
herein, we show that endogenous nitro-linolenic acid (NO2-Ln) can modulate S nitrosoglutathione (GSNO) biosynthesis in Arabidopsis. The incubation of NO2-Ln with
GSH was analyzed by LC-MS/MS and the in vitro synthesis of GSNO was noted. The in
vivo confirmation of this behavior was carried out by incubating Arabidopsis plants with
15N-labeled NO2-Ln throughout the roots, and 15N-labeled GSNO (GS15NO) was
detected in the leaves. With the aim to go in depth in the relation of NO2-FA and GSNO
in plants, Arabidopsis alkenal reductase mutants (aer mutants) which modulate NO2-FAs
levels were used. Our results constitute the first evidence of the modulation of a key NO
biological reservoir in plants (GSNO) by these novel NO2-FAs, increasing knowledge
about S-nitrosothiols and GSNO-signaling pathways in plants.This work was supported by an ERDF grant
cofinanced by the Ministry of Economy and Competitiveness
FIGURE 7 | Modulation of GSNO-signalling pathway by NO2-Ln in Arabidopsis leaves. NO2-Ln is up-taken by the root system and transported to plant leaves. Once in
these organs, NO2-Ln can release nitric oxide (NO) and mediate the S-nitrosation of abundant glutathione (GSH) present in plant leaves and leading to the formation of
S-nitrosoglutathione (GSNO). The generation of this low-molecular weight S-nitrosothiol (SNO) from NO2-Ln can affect the SNO-signaling pathway by modulating the
transport and storage of NO, the response to several (a)biotic stress conditions or mediating the ability of SNO to perform post-translational modifications.
Mata-Pe´ rez et al. Nitro-Fatty Acids Generates S-Nitrosogluthatione
Frontiers in Plant Science | www.frontiersin.org 10 June 2020 | Volume 11 | Article 962
(project PGC2018-096405-B-100), I+D+i Projects in the
framework of the Andalusia 2014-2020 ERDF Operational
Programme (Reference 1263509), Funding for the recruitment
of researchers under the Action 10 of the Research Support Plan
of the University of Jaén (2019-2020; R.02/10/2020) and the
Junta de Andalucía (group BIO286) in Spain. LC-MS/MS
technical and human support provided by CICT of
Universidad de Jaé n (UJA, MINECO, Junta de Andalućıa,
FEDER) is gratefully acknowledged
Entomological Surveillance of Behavioural Resilience and Resistance in Residual Malaria Vector Populations.
The most potent malaria vectors rely heavily upon human blood so they are vulnerable to attack with insecticide-treated nets (ITNs) and indoor residual spraying (IRS) within houses. Mosquito taxa that can avoid feeding or resting indoors, or by obtaining blood from animals, mediate a growing proportion of the dwindling transmission that persists as ITNs and IRS are scaled up. Increasing frequency of behavioural evasion traits within persisting residual vector systems usually reflect the successful suppression of the most potent and vulnerable vector taxa by IRS or ITNs, rather than their failure. Many of the commonly observed changes in mosquito behavioural patterns following intervention scale-up may well be explained by modified taxonomic composition and expression of phenotypically plastic behavioural preferences, rather than altered innate preferences of individuals or populations. Detailed review of the contemporary evidence base does not yet provide any clear-cut example of true behavioural resistance and is, therefore, consistent with the hypothesis presented. Caution should be exercised before over-interpreting most existing reports of increased frequency of behavioural traits which enable mosquitoes to evade fatal contact with insecticides: this may simply be the result of suppressing the most behaviourally vulnerable of the vector taxa that constituted the original transmission system. Mosquito taxa which have always exhibited such evasive traits may be more accurately described as behaviourally resilient, rather than resistant. Ongoing national or regional entomological monitoring surveys of physiological susceptibility to insecticides should be supplemented with biologically and epidemiologically meaningfully estimates of malaria vector population dynamics and the behavioural phenotypes that determine intervention impact, in order to design, select, evaluate and optimize the implementation of vector control measures
Testing real-time systems using TINA
The paper presents a technique for model-based black-box conformance testing of real-time systems using the Time Petri Net Analyzer TINA. Such test suites are derived from a prioritized time Petri net composed of two concurrent sub-nets specifying respectively the expected behaviour of the system under test and its environment.We describe how the toolbox TINA has been extended to support automatic generation of time-optimal test suites. The result is optimal in the sense that the set of test cases in the test suite have the shortest possible accumulated time to be executed. Input/output conformance serves as the notion of implementation correctness, essentially timed trace inclusion taking environment assumptions into account. Test cases selection is based either on using manually formulated test purposes or automatically from various coverage criteria specifying structural criteria of the model to be fulfilled by the test suite. We discuss how test purposes and coverage criterion are specified in the linear temporal logic SE-LTL, derive test sequences, and assign verdicts
Software Model Checking with Explicit Scheduler and Symbolic Threads
In many practical application domains, the software is organized into a set
of threads, whose activation is exclusive and controlled by a cooperative
scheduling policy: threads execute, without any interruption, until they either
terminate or yield the control explicitly to the scheduler. The formal
verification of such software poses significant challenges. On the one side,
each thread may have infinite state space, and might call for abstraction. On
the other side, the scheduling policy is often important for correctness, and
an approach based on abstracting the scheduler may result in loss of precision
and false positives. Unfortunately, the translation of the problem into a
purely sequential software model checking problem turns out to be highly
inefficient for the available technologies. We propose a software model
checking technique that exploits the intrinsic structure of these programs.
Each thread is translated into a separate sequential program and explored
symbolically with lazy abstraction, while the overall verification is
orchestrated by the direct execution of the scheduler. The approach is
optimized by filtering the exploration of the scheduler with the integration of
partial-order reduction. The technique, called ESST (Explicit Scheduler,
Symbolic Threads) has been implemented and experimentally evaluated on a
significant set of benchmarks. The results demonstrate that ESST technique is
way more effective than software model checking applied to the sequentialized
programs, and that partial-order reduction can lead to further performance
improvements.Comment: 40 pages, 10 figures, accepted for publication in journal of logical
methods in computer scienc
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