3,144 research outputs found
Von Neumann Regular Cellular Automata
For any group and any set , a cellular automaton (CA) is a
transformation of the configuration space defined via a finite memory set
and a local function. Let be the monoid of all CA over .
In this paper, we investigate a generalisation of the inverse of a CA from the
semigroup-theoretic perspective. An element is von
Neumann regular (or simply regular) if there exists
such that and , where is the composition of functions. Such an
element is called a generalised inverse of . The monoid
itself is regular if all its elements are regular. We
establish that is regular if and only if
or , and we characterise all regular elements in
when and are both finite. Furthermore, we study
regular linear CA when is a vector space over a field ; in
particular, we show that every regular linear CA is invertible when is
torsion-free elementary amenable (e.g. when ) and , and that every linear CA is regular when
is finite-dimensional and is locally finite with for all .Comment: 10 pages. Theorem 5 corrected from previous versions, in A.
Dennunzio, E. Formenti, L. Manzoni, A.E. Porreca (Eds.): Cellular Automata
and Discrete Complex Systems, AUTOMATA 2017, LNCS 10248, pp. 44-55, Springer,
201
Cancer Mortality in Older Mexican Individuals (2000 â 2010)
The article shows the trends of cancer mortality in older mexican individuals during the period from 2000 to 201
Two Boundaries Separate Borrelia burgdorferi Populations in North America
Understanding the spread of infectious diseases is crucial for implementing effective control measures. For this, it is important to obtain information on the contemporary population structure of a disease agent and to infer the evolutionary processes that may have shaped it. Here, we investigate on a continental scale the population structure of Borrelia burgdorferi, the causative agent of Lyme borreliosis (LB), a tick-borne disease, in North America. We test the hypothesis that the observed d population structure is congruent with recent population expansions and that these were preceded by bottlenecks mostly likely caused by the near extirpation in the 1900s of hosts required for sustaining tick populations. Multilocus sequence typing and complementary population analytical tools were used to evaluate B. burgdorferi samples collected in the Northeastern, Upper Midwestern, and Far-Western United States and Canada. The spatial distribution of sequence types (STs) and inferred population boundaries suggest that the current populations are geographically separated. One major population boundary separated western B. burgdorferi populations transmitted by Ixodes pacificus in California from Eastern populations transmitted by I. scapularis; the other divided Midwestern and Northeastern populations. However, populations from all three regions were genetically closely related. Together, our findings suggest that although the contemporary populations of North American B. burgdorferi now com- prise three geographically separated subpopulations with no or limited gene flow among them, they arose from a common ancestral population. A comparative analysis of the B. burgdorferi outer surface protein C (ospC) gene revealed novel linkages and provides additional insights into the genetic characteristics of strains
Finding Respondents from Minority Groups
The recruitment of respondents belonging to ethnic minorities poses important challenges in social and health research. This paper reflects on the enablers and barriers to recruitment that we encountered in our research work with persons belonging to ethnic minorities. Additionally, we applied the Matching Model of Recruitment, a theoretical framework concerning minority recruitment, to guide our reflection. We also explored its applicability as a research design tool. In assessing our research experience, we learned that minority recruitment in social and health research is influenced by the social context of all key players involved in the research. Also, there are enablers and barriers within that social context facilitating or delaying the recruitment process. The main enablers to recruit respondents belonging to ethnic minorities include working with community agencies and gatekeepers who share a common vision with researchers and the latterâs ability to gain the trust of potential respondents. The main barriers include demanding too much from these same community agencies and gatekeepers and ignoring factors that could delay the completion of the research. Although we found the Matching Model of Recruitment to be an effective tool in assessing the processes of recruiting respondents belonging to ethnic minorities, further empirical research is needed to explore its usefulness during the research planning phase
T-cell derived acetylcholine aids host defenses during enteric bacterial infection with Citrobacter rodentium.
The regulation of mucosal immune function is critical to host protection from enteric pathogens but is incompletely understood. The nervous system and the neurotransmitter acetylcholine play an integral part in host defense against enteric bacterial pathogens. Here we report that acetylcholine producing-T-cells, as a non-neuronal source of ACh, were recruited to the colon during infection with the mouse pathogen Citrobacter rodentium. These ChAT+ T-cells did not exclusively belong to one Th subset and were able to produce IFNÎł, IL-17A and IL-22. To interrogate the possible protective effect of acetylcholine released from these cells during enteric infection, T-cells were rendered deficient in their ability to produce acetylcholine through a conditional gene knockout approach. Significantly increased C. rodentium burden was observed in the colon from conditional KO (cKO) compared to WT mice at 10 days post-infection. This increased bacterial burden in cKO mice was associated with increased expression of the cytokines IL-1ÎČ, IL-6, and TNFα, but without significant changes in T-cell and ILC associated IL-17A, IL-22, and IFNÎł, or epithelial expression of antimicrobial peptides, compared to WT mice. Despite the increased expression of pro-inflammatory cytokines during C. rodentium infection, inducible nitric oxide synthase (Nos2) expression was significantly reduced in intestinal epithelial cells of ChAT T-cell cKO mice 10 days post-infection. Additionally, a cholinergic agonist enhanced IFNÎł-induced Nos2 expression in intestinal epithelial cell in vitro. These findings demonstrated that acetylcholine, produced by specialized T-cells that are recruited during C. rodentium infection, are a key mediator in host-microbe interactions and mucosal defenses
Streptococcus lutetiensis Bacteremia. First Clindamycin Resistant Isolate Carrying lnuB Gene
First Case of Streptococcus lutetiensis Bacteremia Involving a Clindamycin-Resistant Isolate Carrying the lnuB Gene.Fil: Almuzara, Marisa. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Departamento de BioquĂmica ClĂnica; ArgentinaFil: Bonofiglio, Laura. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Departamento de MicrobiologĂa, InmunologĂa y BiotecnologĂa; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay; ArgentinaFil: Cittadini, Roberto Arnaldo. Instituto Nacional de Tecnologia Agropecuaria; Argentina. Sanatorio Mater Dei; ArgentinaFil: Vera Ocampo, Cecilia. Sanatorio Mater Dei; ArgentinaFil: Montilla, A.. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas . Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de Inmunologia, Genetica y Metabolismo; ArgentinaFil: del Castillo, M.. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Departamento de MicrobiologĂa, InmunologĂa y BiotecnologĂa; ArgentinaFil: Ramirez, Maria Soledad. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de Investigaciones en MicrobiologĂa y ParasitologĂa MĂ©dica; ArgentinaFil: Mollerach, Marta Eugenia. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Departamento de MicrobiologĂa, InmunologĂa y BiotecnologĂa; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Vay, Carlos Alberto. Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Departamento de BioquĂmica ClĂnica; Argentin
Cosmic acceleration from asymmetric branes
We consider a single 3-brane sitting in between two different five
dimensional spacetimes. On each side of the brane, the bulk is a solution to
Gauss-Bonnet gravity, although the bare cosmological constant, funda mental
Planck scale, and Gauss-Bonnet coupling can differ. This asymmetry leads to
weighted junction conditions across the brane and interesting brane cosmology.
We focus on two special cases: a generalized Randall-Sundrum model without any
Gauss-Bonnet terms, and a stringy model, without any bare cosmological
constants, and positive Gauss-Bonnet coupling. Even though we assume there is
no vacuum energy on the brane, we find late time de Sitter cosmologies can
occur. Remarkably, in certain parameter regions, this acceleration is preceded
by a period of matter/radiation domination, with , all the
way back to nucleosynthesis.Comment: Version appearing in CQ
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Granger causality-based information fusion applied to electrical measurements from power transformers
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