120 research outputs found
One-step transformation of 2-oxa-3-azabicyclo[2.2.1]hept-5-ene and methyl 2,3-diazabicyclo[2.2.1]heptane-2-carboxylate to ion uptake systems
Linker generated duplexes of the title compounds- prepared from cyclopentadiene- with
possibility for positioning of four oxygen in the cavity, are shown to be excellent ion uptake
systems. Mass spectrometric doping studies with lithium, sodium, potassium and silver ions,
show a clear preference for lithium complexation. The lithium salts of the best examples have
been prepared and characterized
Probabilistic Guarded P Systems, A New Formal Modelling Framework
Multienvironment P systems constitute a general, formal
framework for modelling the dynamics of population biology, which consists
of two main approaches: stochastic and probabilistic. The framework
has been successfully used to model biologic systems at both micro (e.g.
bacteria colony) and macro (e.g. real ecosystems) levels, respectively.
In this paper, we extend the general framework in order to include
a new case study related to P. Oleracea species. The extension is made
by a new variant within the probabilistic approach, called Probabilistic
Guarded P systems (in short, PGP systems). We provide a formal definition,
a simulation algorithm to capture the dynamics, and a survey of
the associated software.Ministerio de EconomĂa y Competitividad TIN2012- 37434Junta de AndalucĂa P08-TIC-0420
The Nondeterministic Waiting Time Algorithm: A Review
We present briefly the Nondeterministic Waiting Time algorithm. Our technique
for the simulation of biochemical reaction networks has the ability to mimic
the Gillespie Algorithm for some networks and solutions to ordinary
differential equations for other networks, depending on the rules of the
system, the kinetic rates and numbers of molecules. We provide a full
description of the algorithm as well as specifics on its implementation. Some
results for two well-known models are reported. We have used the algorithm to
explore Fas-mediated apoptosis models in cancerous and HIV-1 infected T cells
A computational modeling for real ecosystems based on P systems
In this paper, a P systems based general framework for modeling ecosystems
dynamics is presented. Particularly, ecosystems are specified by means of multienvironment
P systems composed of a finite number of environments, each of them having an
extended P system with active membranes. The semantics is of a probabilistic type and it is
implemented by assigning each rule of the system a probabilistic constant which depends
on the environment and the run time. As a case study, two real ecosystems are described:
scavenger birds in the Catalan Pyrenees and the zebra mussel (Dreissena Polymorpha) in
Ribarroja reservoir (Spain).Ministerio de Ciencia e InnovaciĂłn TIN2009â13192Junta de AndalucĂa P08âTIC-0420
Genetic and genomic resources, and breeding for accelerating improvement of small millets: current status and future interventions
Current agricultural and food systems encourage research and development on major crops, neglecting regionally important
minor crops. Small millets include a group of small- seeded cereal crops of the grass family Poaceae. This includes
finger millet, foxtail millet, proso millet, barnyard millet, kodo millet, little millet, teff, fonio, jobâs tears, guinea millet,
and browntop millet. Small millets are an excellent choice to supplement major staple foods for crop and dietary diversity
because of their diverse adaptation on marginal lands, less water requirement, lesser susceptibility to stresses, and nutritional
superiority compared to major cereal staples. Growing interest among consumers about healthy diets together with
climate-resilient features of small millets underline the necessity of directing more research and development towards these
crops. Except for finger millet and foxtail millet, and to some extent proso millet and teff, other small millets have received
minimal research attention in terms of development of genetic and genomic resources and breeding for yield enhancement.
Considerable breeding efforts were made in finger millet and foxtail millet in India and China, respectively, proso millet in
the United States of America, and teff in Ethiopia. So far, five genomes, namely foxtail millet, finger millet, proso millet,
teff, and Japanese barnyard millet, have been sequenced, and genome of foxtail millet is the smallest (423-510 Mb) while
the largest one is finger millet (1.5 Gb). Recent advances in phenotyping and genomics technologies, together with available
germplasm diversity, could be utilized in small millets improvement. This review provides a comprehensive insight into
the importance of small millets, the global status of their germplasm, diversity, promising germplasm resources, and breeding
approaches (conventional and genomic approaches) to accelerate climate-resilient and nutrient-dense small millets for
sustainable agriculture, environment, and healthy food systems
Computing with cells: membrane systems - some complexity issues.
Membrane computing is a branch of natural computing which abstracts computing models from the structure and the functioning of the living cell. The main ingredients of membrane systems, called P systems, are (i) the membrane structure, which consists of a hierarchical arrangements of membranes which delimit compartments where (ii) multisets of symbols, called objects, evolve according to (iii) sets of rules which are localised and associated with compartments. By using the rules in a nondeterministic/deterministic maximally parallel manner, transitions between the system configurations can be obtained. A sequence of transitions is a computation of how the system is evolving. Various ways of controlling the transfer of objects from one membrane to another and applying the rules, as well as possibilities to dissolve, divide or create membranes have been studied. Membrane systems have a great potential for implementing massively concurrent systems in an efficient way that would allow us to solve currently intractable problems once future biotechnology gives way to a practical bio-realization. In this paper we survey some interesting and fundamental complexity issues such as universality vs. nonuniversality, determinism vs. nondeterminism, membrane and alphabet size hierarchies, characterizations of context-sensitive languages and other language classes and various notions of parallelism
T cell receptor repertoires associated with control and disease progression following Mycobacterium tuberculosis infection
Antigen-specific, MHC-restricted αÎČ T cells are necessary for protective immunity against Mycobacterium tuberculosis, but the ability to broadly study these responses has been limited. In the present study, we used single-cell and bulk T cell receptor (TCR) sequencing and the GLIPH2 algorithm to analyze M. tuberculosis-specific sequences in two longitudinal cohorts, comprising 166 individuals with M. tuberculosis infection who progressed to either tuberculosis (nâ=â48) or controlled infection (nâ=â118). We found 24 T cell groups with similar TCR-ÎČ sequences, predicted by GLIPH2 to have common TCR specificities, which were associated with control of infection (nâ=â17), and others that were associated with progression to disease (nâ=â7). Using a genome-wide M. tuberculosis antigen screen, we identified peptides targeted by T cell similarity groups enriched either in controllers or in progressors. We propose that antigens recognized by T cell similarity groups associated with control of infection can be considered as high-priority targets for future vaccine development
Membrane Computing as a Modelling Tool: Looking Back and Forward from Sevilla
This paper is a tribute to Prof. Mario de JesĂșs PĂ©rez-
Jiménez. An overview of modelling applications in membrane computing
has been compiled, trying to narrate it from a historical perspective
and including numerous bibliographical references. Since being exhaustive
was obviously out of scope, this quick tour on almost two decades
of applications is biased, paying special attention to the contributions
in which Prof. Pérez-Jiménez and members of his research group were
involved.Ministerio de EconomĂa y Competitividad TIN2017-89842-
Intravenous magnesium prevents atrial fibrillation after coronary artery bypass grafting: a meta-analysis of 7 double-blind, placebo-controlled, randomized clinical trials
<p>Abstract</p> <p>Background</p> <p>Postoperative atrial fibrillation (POAF) is the most common complication after coronary artery bypass grafting (CABG). The preventive effect of magnesium on POAF is not well known. This meta-analysis was undertaken to assess the efficacy of intravenous magnesium on the prevention of POAF after CABG.</p> <p>Methods</p> <p>Eligible studies were identified from electronic databases (Medline, Embase, and the Cochrane Library). The primary outcome measure was the incidence of POAF. The meta-analysis was performed with the fixed-effect model or random-effect model according to heterogeneity.</p> <p>Results</p> <p>Seven double-blind, placebo-controlled, randomized clinical trials met the inclusion criteria including 1,028 participants. The pooled results showed that intravenous magnesium reduced the incidence of POAF by 36% (RR 0.64; 95% confidence interval (CI) 0.50-0.83; <it>P </it>= 0.001; with no heterogeneity between trials (heterogeneity <it>P </it>= 0.8, <it>I</it><sup>2 </sup>= 0%)).</p> <p>Conclusions</p> <p>This meta-analysis indicates that intravenous magnesium significantly reduces the incidence of POAF after CABG. This finding encourages the use of intravenous magnesium as an alternative to prevent POAF after CABG. But more high quality randomized clinical trials are still need to confirm the safety.</p
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