CD45 expression discriminates waves of embryonic megakaryocytes in the mouse.

Embryonic megakaryopoiesis starts in the yolk sac on gestational day 7.5 as part of the primitive wave of hematopoiesis, and it continues in the fetal liver when this organ is colonized by hematopoietic progenitors between day 9.5 and 10.5, as the definitive hematopoiesis wave. We characterized the precise phenotype of embryo megakaryocytes in the liver at gestational day 11.5, identifying them as CD41++CD45-CD9++CD61+MPL+CD42c+ tetraploid cells that express megakaryocyte-specific transcripts and display differential traits when compared to those present in the yolk sac at the same age. In contrast to megakaryocytes from adult bone marrow, embryo megakaryocytes are CD45- until day 13.5 of gestation, as are both the megakaryocyte progenitors and megakaryocyte/erythroid-committed progenitors. At gestational day 11.5, liver and yolk sac also contain CD41+CD45+ and CD41+CD45- cells. These populations, and that of CD41++CD45-CD42c+ cells, isolated from liver, differentiate in culture into CD41++CD45-CD42c+ proplatelet-bearing megakaryocytes. Also present at this time are CD41-CD45++CD11b+ cells, which produce low numbers of CD41++CD45-CD42c+ megakaryocytes in vitro, as do fetal liver cells expressing the macrophage-specific Csf receptor-1 (Csf1r/CD115) from MaFIA transgenic mice, which give rise poorly to CD41++CD45-CD42c+ embryo megakaryocytes both in vivo and in vitro In contrast, around 30% of adult megakaryocytes (CD41++CD45++CD9++CD42c+) from C57BL/6 and MaFIA mice express CD115. We propose that differential pathways operating in the mouse embryo liver at gestational day 11.5 beget CD41++CD45-CD42c+ embryo megakaryocytes that can be produced from CD41+CD45- or from CD41+CD45+ cells, at difference from those from bone marrow.

Dynamics of the splenic innate-like CD19⁺CD45Rlo cell population from adult mice in homeostatic and activated conditions.

In the adult spleen, CD19⁺CD45R(-/lo) (19⁺45R(lo)) lymphocytes of embryonic origin exist as a distinct population to that of the conventional B cell lineage. These cells display a plasmablast phenotype, and they spontaneously secrete IgG1 and IgA, whereas the bone marrow population of 19⁺45R(lo) cells contains B1 progenitors. In this study, we show that 19⁺45R(lo) cells are also present in Peyer's patches and in the spleen throughout the life span of wild-type mice, beginning at postnatal day 7. Although this population is heterogeneous, the surface phenotype of most of these cells distinguishes them from follicular, transitional, marginal zone, and B1 cells. In CBA/CaHN mice, few 19⁺45R(lo) cells were detected at postnatal day 7, and none was observed in the adult spleen. Splenic 19⁺45R(lo) cells exhibited homeostatic BrdU uptake in vivo and actively transcribed cell cycle genes. When transferred to immunodeficient RAG2⁻/⁻γchain⁻/⁻ recipient mice, 19⁺45R(lo) cells survived and differentiated into IgG1- and IgA-plasma cells. Moreover, in vitro stimulation of splenic 19⁺45R(lo) cells with LPS, CpG, BAFF/IL4, and CD40/IL4 induced cell proliferation, IgG1/IgA secretion and the release of IL-10, suggesting a potential immunoregulatory role for this subset of innate-like B cells.

Detection scales for the risk of domestic abuse and self-negligent behavior in elderly persons (EDMA).

This article presents the results of a study carried out to determine the psychometric properties of an instrument designed for use by social services professionals to detect domestic abuse and self-negligent behavior in elderly persons. After giving a description of the features of the instrument and the design of the study, the results obtained, in terms of the reliability and validity of the instrument, are shown. Finally, the authors compare their instrument and its test results with other established instruments and indicate the limits of their study.

Methylation cycle, arginine-creatine pathway and asymmetric dimethylarginine in paediatric renal transplant.

BACKGROUND: Hyperhomocysteinaemia represents an important cause of morbidity in recipients of renal transplants, but few investigations have been carried out to evaluate the status of the methylation cycle and its relation with levels of new cardiovascular biomarkers, such as asymmetric dimethylarginine (ADMA). METHODS: Twenty-six children and adolescents aged 7-18 years (17 male, 9 female) with stable renal transplants were recruited for the study. None had received treatment with folate, vitamin B(12) or statins. Levels of ADMA in plasma and of components of the methylation cycle and arginine (Arg)-creatine pathway in plasma and urine were analysed by specific analytical methods. Results were compared to those obtained by us with identical methods in healthy children of similar age. RESULTS: Concentrations of homocysteine (Hcys), S-adenosylhomocysteine (SAH) and ADMA were significantly higher, while S-adenosylmethionine (SAM)/SAH and Arg/ADMA ratios were significantly lower than controls. Arg/ADMA ratio correlated with plasma guanidinoacetate. The components of the methylation cycle, Hcys and SAH correlated with renal function. CONCLUSIONS: Children with renal transplant showed low methylation power (SAM/SAH) mainly due to increased levels of SAH which acts as a cardiovascular biomarker. Elevated values of ADMA and low Arg/ADMA coefficients also represent a novel finding because it inhibits nitric oxide synthesis contributing to endothelial dysfunction and cardiovascular risk in such patients.

Vitamin D receptor gene, biochemical bone markers and bone mineral density in Mexican women on dialysis.

BACKGROUND: The influence of the Bsm1 polymorphism of the vitamin D receptor (VDR) gene on mineral and bone disorders in chronic kidney disease (CKD) is still under discussion. The aim of this study was to analyse the relationship between VDR polymorphism, bone mineral density (BMD), biochemical bone markers and clinical factors in women on peritoneal dialysis (PD) and haemodialysis (HD). METHODS: In a cross-sectional study, 197 women (42 +/- 10 years; 25% with diabetes mellitus (DM); body mass index (BMI) 25.26 +/- 4.77 kg/m(2)) treated by PD (72%) or HD (28%) underwent measurements of BMD (measured at the calcaneus by quantitative ultrasound; expressed as T- and Z-scores) and plasma total calcium (tCa), intact parathyroid hormone 1-84 (iPTH), phosphorus, albumin, glucose, osteoprotegerin (OPG), fetuin-A, intact osteocalcin-49 and N-MID fragment 1-43 aa (N-MID osteocalcin) N-terminal propeptide of type 1 procollagen (PINP) and C-terminal telopeptide-beta aspartic acid (BCL). DNA was extracted from peripheral blood. PCR products were digested with Bsm1 to analyse VDR polymorphism. RESULTS: The Z-score of BMD was -1.1 +/- 1.03. According to the values of osteopenia (T-score = -1.0), patients with higher BMD were younger, had lower frequency of amenorrhoea and diabetes and had higher serum creatinine and fetuin levels as well as lower levels of PINP. In a stepwise multivariate logistics analysis, osteopenia was associated with presence of genotype BB+Bb (OR = 3.26, P < or = 0.003) and age (OR = 0.95, P = 0.050). According to the B allele, bb: n = 126 (64%) and BB+Bb: n = 71(36%), group bb had significantly higher mean Z-scores (-0.97 +/- 1.0 vs -1.3+/-0.92; P < or = 0.021). CONCLUSIONS: The high frequency of osteopenia observed in female CKD patients on dialysis is associated with age and genetic predisposition as revealed by its association to the Bsm1 VDR polymorphism.

Generalized Sznajd model for opinion propagation.

In the last decade the Sznajd model has been successfully employed in modeling some properties and scale features of both proportional and majority elections. We propose a version of the Sznajd model with a generalized bounded confidence rule-a rule that limits the convincing capability of agents and that is essential to allow coexistence of opinions in the stationary state. With an appropriate choice of parameters it can be reduced to previous models. We solved this model both in a mean-field approach (for an arbitrary number of opinions) and numerically in a Barabási-Albert network (for three and four opinions), studying the transient and the possible stationary states. We built the phase portrait for the special cases of three and four opinions, defining the attractors and their basins of attraction. Through this analysis, we were able to understand and explain discrepancies between mean-field and simulation results obtained in previous works for the usual Sznajd model with bounded confidence and three opinions. Both the dynamical system approach and our generalized bounded confidence rule are quite general and we think it can be useful to the understanding of other similar models.

Detecting Self-Neglect: A Comparative Study of Indicators and Risk Factors in a Spanish Population.

Objective: To provide information relevant for detecting potential self-neglecting elders in a Spanish population. Method: This study analyzed the records of 269 social services clients. They were classified in three groups: presumed adequate treatment (AT), at increased risk of abuse (RA), and at increased risk of self-neglect (SN). Social service professionals assessed these cases. Results: Elders at SN presented greater problems in terms of their personal hygiene and appearance, their living conditions, and their ability to look after themselves, to attend to their own health, to realistically assess their situation, and to accept help from others. Variables used to classify the participants correctly predicted 91.1% of the AT cases. However, they produced incorrect predictions in the other two groups. Discussion: These results have important implications for detecting self-neglect, but they need to be confirmed with more representative population samples.

Psychometric Properties of the Spanish Adaptation of the Indicators of Abuse (IOA) Screen.

The objectives of this study were to replicate the analyses conducted by the creators of the Indicators of Abuse (IOA) Screen with a Spanish sample group and compare the results, to present new validity evidences, to analyze which items were more relevant in the detection of situations of risk of abuse, and to establish a cut-off point to interpret the obtained scores. The IOA was used by 46 professionals from social services teams who assessed the situation of 231 elderly individuals and their main caregivers. The obtained results advocated towards unidimensionality of the scale. It showed a high level of internal consistency (α = .94). The Confidence Interval of 99% for the alpha coefficient was between .92 and .95. The ordinal alpha coefficient reached the value of .98. The total score of the scale showed adequate temporal stability (r = .91; p ≤ .001; N = 163). Statistically significant differences (t-test) in the mean scores of most of the items were found between cases of adequate treatment and cases of risk of abuse. The scale classified correctly 93% of all cases. The best balance between sensitivity and specificity was found at the cut-off point given by score 16 (Sensitivity = 0.94, Specificity = 0.85). The results appear to confirm the validity evidence of the instrument when used with a Spanish population. However, it is necessary to conduct further research and confirm the results with wider, more representative sample groups.

Network of epicenters of the Olami-Feder-Christensen model of earthquakes.

We study the dynamics of the Olami-Feder-Christensen (OFC) model of earthquakes, focusing on the behavior of sequences of epicenters regarded as a growing complex network. Besides making a detailed and quantitative study of the effects of the borders (the occurrence of epicenters is dominated by a strong border effect which does not scale with system size), we examine the degree distribution and the degree correlation of the graph. We detect sharp differences between the conservative and nonconservative regimes of the model. Removing border effects, the conservative regime exhibits a Poisson-like degree statistics and is uncorrelated, while the nonconservative has a broad power-law-like distribution of degrees (if the smallest events are ignored), which reproduces the observed behavior of real earthquakes. In this regime the graph has also an unusually strong degree correlation among the vertices with higher degree, which is the result of the existence of temporary attractors for the dynamics: as the system evolves, the epicenters concentrate increasingly on fewer sites, exhibiting strong synchronization, but eventually spread again over the lattice after a series of sufficiently large earthquakes. We propose an analytical description of the dynamics of this growing network, considering a Markov process network with hidden variables, which is able to account for the mentioned properties.

Controlled recovery of phylogenetic communities from an evolutionary model using a network approach.

This works reports the use of a complex network approach to produce a phylogenetic classification tree of a simple evolutionary model. This approach has already been used to treat proteomic data of actual extant organisms, but an investigation of its reliability to retrieve a traceable evolutionary history is missing. The used evolutionary model includes key ingredients for the emergence of groups of related organisms by differentiation through random mutations and population growth, but purposefully omits other realistic ingredients that are not strictly necessary to originate an evolutionary history. This choice causes the model to depend only on a small set of parameters, controlling the mutation probability and the population of different species. Our results indicate that for a set of parameter values, the phylogenetic classification produced by the used framework reproduces the actual evolutionary history with a very high average degree of accuracy. This includes parameter values where the species originated by the evolutionary dynamics have modular structures. In the more general context of community identification in complex networks, our model offers a simple setting for evaluating the effects, on the efficiency of community formation and identification, of the underlying dynamics generating the network itself.

Mean-field approximation for the Sznajd model in complex networks.

This paper studies the Sznajd model for opinion formation in a population connected through a general network. A master equation describing the time evolution of opinions is presented and solved in a mean-field approximation. Although quite simple, this approximation allows us to capture the most important features regarding the steady states of the model. When spontaneous opinion changes are included, a discontinuous transition from consensus to polarization can be found as the rate of spontaneous change is increased. In this case we show that a hybrid mean-field approach including interactions between second nearest neighbors is necessary to estimate correctly the critical point of the transition. The analytical prediction of the critical point is also compared with numerical simulations in a wide variety of networks, in particular Barabási-Albert networks, finding reasonable agreement despite the strong approximations involved. The same hybrid approach that made it possible to deal with second-order neighbors could just as well be adapted to treat other problems such as epidemic spreading or predator-prey systems.

Distribution of epicenters in the Olami-Feder-Christensen model.

We show that the well established Olami-Feder-Christensen (OFC) model for the dynamics of earthquakes is able to reproduce a striking property of real earthquake data. Recently, it has been pointed out by Abe and Suzuki that the epicenters of earthquakes could be connected in order to generate a graph, with properties of a scale-free network of the Barabási-Albert type. However, only the nonconservative version of the Olami-Feder-Christensen model is able to reproduce this behavior. The conservative version, instead, behaves like a random graph. Besides indicating the robustness of the model to describe earthquake dynamics, those findings reinforce that conservative and nonconservative versions of the OFC model are qualitatively different. Also, we propose a completely different dynamical mechanism that, even without an explicit rule of preferential attachment, generates a scale-free network. The preferential attachment is in this case a "byproduct" of the long term correlations associated with the self-organized critical state.

Axelrod's model with surface tension.

In this work we propose a subtle change in Axelrod's model for the dissemination of culture. The mechanism consists of excluding from the set of potentially interacting neighbors those that would never possibly exchange. Although the alteration proposed does not alter the state space topologically, it yields significant qualitative changes, specifically the emergence of surface tension, driving the system in some cases to metastable states. The transient behavior is considerably richer, and cultural regions become stable leading to the formation of different spatiotemporal patterns. A metastable "glassy" phase emerges between the globalized phase and the disordered, multicultural phase.

Exit probability of the one-dimensional q-voter model: analytical results and simulations for large networks.

We discuss the exit probability of the one-dimensional q-voter model and present tools to obtain estimates about this probability, both through simulations in large networks (around 10(7) sites) and analytically in the limit where the network is infinitely large. We argue that the result E(ρ) = ρ(q)/ρ(q) + (1-ρ)(q), that was found in three previous works [F. Slanina, K. Sznajd-Weron, and P. Przybyla, Europhys. Lett. 82, 18006 (2008); R. Lambiotte and S. Redner, Europhys. Lett. 82, 18007 (2008), for the case q = 2; and P. Przybyla, K. Sznajd-Weron, and M. Tabiszewski, Phys. Rev. E 84, 031117 (2011), for q > 2] using small networks (around 10(3) sites), is a good approximation, but there are noticeable deviations that appear even for small systems and that do not disappear when the system size is increased (with the notable exception of the case q = 2). We also show that, under some simple and intuitive hypotheses, the exit probability must obey the inequality ρ(q)/ρ(q) + (1-ρ) ≤ E(ρ) ≤ ρ/ρ + (1-ρ)(q) in the infinite size limit. We believe this settles in the negative the suggestion made [S. Galam and A. C. R. Martins, Europhys. Lett. 95, 48005 (2001)] that this result would be a finite size effect, with the exit probability actually being a step function. We also show how the result that the exit probability cannot be a step function can be reconciled with the Galam unified frame, which was also a source of controversy.

Postnatal and adult immunoglobulin repertoires of innate-like CD19(+)CD45R(lo) B Cells.

The diversity in antibody repertoire relies on different B cell populations working efficiently to fulfil distinct specific functions. We recently described an innate-like CD19(+)CD45R(-/lo) (19(+)45R(lo)) cell population in postnatal unstimulated adult mice, a heterogeneous population containing cells expressing immunoglobulin M (IgM) and others behaving as differentiated mature B lymphocytes (intracytoplasmic IgG1, AID(+), Blimp-1(+)RAG2(-)). In the present study, we characterized the Ig repertoire expressed by splenic 19(+)45R(lo) cells, assuming that they would bear a restricted repertoire biased for germline rearrangements and low mutation rates similar to other innate-like cells. Sequences from 19(+)45R(lo) cells displayed a variety of V, D and J regions, and the analysis of the CDR-H3 region revealed an intermediate overall CDR-H3 length and moderate hydrophobicity. Both IgM and switched sequences of PD15 19(+)45R(lo) cells had shorter CDR-H3 region and fewer non-template N nucleotides than adult sequences, as expected for profiles that correspond to an immature phenotype. Regarding the mutation rate in the VH regions, IgG1 sequences already carried a high rate of replacement mutations at PD15, which increased further in the sequences obtained from adult mice. Moreover, statistical models suggest that a proportion of the switched sequences in adult 19(+)45R(lo) cells had experienced antigen selection, unlike other innate-like B cell compartments.

Role of hysteresis in stomatal aperture dynamics.

Stomata are pores responsible for gas exchange in leaves. Several experiments indicate that stomata synchronize into clusters or patches. The patches' coordination may produce oscillations in stomatal conductance. Previous studies claim to reproduce some experimental results. However, none was able to explain the variety of behavior observed in the stomatal dynamics. Recently, Ferraz and Prado suggested a realistic geometry of vein distribution. Although it reproduces the patches, no oscillation was observed and the patches remain static. Without exploring significant details, the authors stated that hysteresis in stomatal aperture could explain several experimental features. In this paper, the hysteresis hypothesis is further explored through the concept of hysteretic operators. We have shown that the hysteresis assumption is sufficient to obtain dynamical patches and oscillations in stomatal conductance. The robustness of this hypothesis is tested by using different hysteresis operators. The model analysis reveals a dependence between the period of oscillation in stomatal conductance and the water deficit between the leaf and the environment. This underlying feature of the model might inspire further experiments to test this hypothesis.

Comparison of the clinical effect of the adhesive strategies of universal adhesives in the treatment of non-carious cervical lesions: systematic review and meta-analysis

Objective: to compare, through a systematic review and a meta-analysis, the clinical effect of the adhesive strategies of universal adhesives (UA) in the treatment of non-carious cervical lesions (NCCLs). material and method: a search of the literature was carried out up to january 2018, in the biomedical databases: Pubmed, Embase, Scielo, Science Direct, SIGLE, LILACS, BBO, Google Scholar and the Central Register of Cochrane Clinical Trials. the selection criteria of the studies were as: randomized clinical trials, with a maximum age of 5 years and which report the clinical effects (marginal adaptation, discoloration or marginal staining, presence of secondary caries, postoperative sensitivity, retention and fractures) of the UA in the treatment of NCCLs. the risk of study bias was analyzed through the Cochrane Handbook of systematic reviews of interventions. results: the search strategy resulted in eight articles that reported no difference in marginal adaptation, discoloration or marginal staining, presence of secondary caries and postoperative sensitivity among the adhesive strategies of the UA; however they reported a difference between the retention and the presence of fractures, with the conventional adhesive strategy resulting in a better clinical effect. conclusion: the reviewed literature suggests that the conventional adhesive strategy of UAs results in greater retention and absence of fractures in the treatment of NCCLs.

Connections between the Sznajd model with general confidence rules and graph theory.

The Sznajd model is a sociophysics model that is used to model opinion propagation and consensus formation in societies. Its main feature is that its rules favor bigger groups of agreeing people. In a previous work, we generalized the bounded confidence rule in order to model biases and prejudices in discrete opinion models. In that work, we applied this modification to the Sznajd model and presented some preliminary results. The present work extends what we did in that paper. We present results linking many of the properties of the mean-field fixed points, with only a few qualitative aspects of the confidence rule (the biases and prejudices modeled), finding an interesting connection with graph theory problems. More precisely, we link the existence of fixed points with the notion of strongly connected graphs and the stability of fixed points with the problem of finding the maximal independent sets of a graph. We state these results and present comparisons between the mean field and simulations in Barabási-Albert networks, followed by the main mathematical ideas and appendices with the rigorous proofs of our claims and some graph theory concepts, together with examples. We also show that there is no qualitative difference in the mean-field results if we require that a group of size q>2, instead of a pair, of agreeing agents be formed before they attempt to convince other sites (for the mean field, this would coincide with the q-voter model).

Coexistence of interacting opinions in a generalized Sznajd model.

The Sznajd model is a sociophysics model that mimics the propagation of opinions in a closed society, where the interactions favor groups of agreeing people. It is based in the Ising and Potts ferromagnetic models and, although the original model used only linear chains, it has since been adapted to general networks. This model has a very rich transient, which has been used to model several aspects of elections, but its stationary states are always consensus states. In order to model more complex behaviors, we have, in a recent work, introduced the idea of biases and prejudices to the Sznajd model by generalizing the bounded confidence rule, which is common to many continuous opinion models, to what we called confidence rules. In that work we have found that the mean field version of this model (corresponding to a complete network) allows for stationary states where noninteracting opinions survive, but never for the coexistence of interacting opinions. In the present work, we provide networks that allow for the coexistence of interacting opinions for certain confidence rules. Moreover, we show that the model does not become inactive; that is, the opinions keep changing, even in the stationary regime. This is an important result in the context of understanding how a rule that breeds local conformity is still able to sustain global diversity while avoiding a frozen stationary state. We also provide results that give some insights on how this behavior approaches the mean field behavior as the networks are changed.

Psychometric properties of the Spanish adaptation of the Indicators of Abuse (IOA) screen

The objectives of this study were to replicate the analyses conducted by the creators of the Indicators of Abuse (IOA) Screen with a Spanish sample group and compare the results, to present new validity evidences, to analyze which items were more relevant in the detection of situations of risk of abuse, and to establish a cut-off point to interpret the obtained scores. The IOA was used by 46 professionals from social services teams who assessed the situation of 231 elderly individuals and their main caregivers. The obtained results advocated towards unidimensionality of the scale. It showed a high level of internal consistency (α = .94). The Confidence Interval of 99% for the alpha coefficient was between .92 and .95. The ordinal alpha coefficient reached the value of .98. The total score of the scale showed adequate temporal stability (r = .91; p ≤ .001; N = 163). Statistically significant differences (t-test) in the mean scores of most of the items were found between cases of adequate treatment and cases of risk of abuse. The scale classified correctly 93% of all cases. The best balance between sensitivity and specificity was found at the cut-off point given by score 16 (Sensitivity = 0.94, Specificity = 0.85). The results appear to confirm the validity evidence of the instrument when used with a Spanish population. However, it is necessary to conduct further research and confirm the results with wider, more representative sample groups

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