Unconventional criticality, scaling breakdown, and diverse universality classes in the Wilson-Cowan model of neural dynamics.

The Wilson-Cowan model constitutes a paradigmatic approach to understanding the collective dynamics of networks of excitatory and inhibitory units. It has been profusely used in the literature to analyze the possible phases of neural networks at a mean-field level, e.g., assuming large fully connected networks. Moreover, its stochastic counterpart allows one to study fluctuation-induced phenomena, such as avalanches. Here we revisit the stochastic Wilson-Cowan model paying special attention to the possible phase transitions between quiescent and active phases. We unveil eight possible types of such transitions, including continuous ones with scaling behavior belonging to known universality classes-such as directed percolation and tricritical directed percolation-as well as six distinct ones. In particular, we show that under some special circumstances, at a so-called "Hopf tricritical directed percolation" transition, rather unconventional behavior is observed, including the emergence of scaling breakdown. Other transitions are discontinuous and show different types of anomalies in scaling and/or exhibit mixed features of continuous and discontinuous transitions. These results broaden our knowledge of the possible types of critical behavior in networks of excitatory and inhibitory units and are, thus, of relevance to understanding avalanche dynamics in actual neuronal recordings. From a more general perspective, these results help extend the theory of nonequilibrium phase transitions into quiescent or absorbing states.

The prognostic value of neutrophile/lymphocyte ratio and serum chemerin to predict maternal-fetal complications in pregnant systemic lupus erythematosus patients.

BACKGROUND: Pregnancy in SLE continues to be a challenge. The neutrophil-to-lymphocyte ratio (NLR) and chemerin are predictors of preeclampsia in the general population; however, their role as predictors of maternal-fetal complications in pregnant SLE patients has not been analyzed. OBJECTIVE: To investigate the prognostic value of NLR and serum chemerin, to predict maternal-fetal complications in pregnant SLE patients, and compare both biomarkers among three study groups. METHODS: Design: Analytical cross-sectional study of cases and controls with the following study groups: systemic lupus erythematosus (SLE), preeclampsia, and healthy. NLR and chemerin serum were determined between 20 and 25 weeks of gestation. Patients were evaluated every 4-6 weeks until pregnancy resolution. Maternal and fetal outcomes were registered. We employed Receiver Operating Characteristic (ROC) curves to validate prognostic values. RESULTS: Seventy pregnant patients were included: 20 with SLE, 20 with preeclampsia, and 30 healthy pregnant women; NLR values were 4 (2.3-5.6) in SLE, 6 (4.6-9.2) in preeclampsia, and 2.8 (2.1-2.9) in the group of healthy women (p = .0001). Chemerin levels were: 26 (15.3-56.2) in SLE, 96 (37.3-146.2) in preeclampsia, and 24.6 ng/mL (15.3-47.4) in the healthy group (p = .007) Maternal complications were observed in 11 (55%), 20 (100%), and 8 (26%) per group, respectively. Thrombocytopenia was the most frequent complication in all pregnant women, followed by hypertensive disorders. Fetal complications were registered in 12 (60%), 16 (80%), and 2 (6.7%), respectively. Congenital malformations and prematurity were the most frequent fetal complications. NLR had good diagnostic accuracy in predicting maternal-fetal complications (AUROC 0.715) p = .015, CI 95% 0.56-0.86, cut-off point level: 2.9, sensitivity 61%, specificity 78%, positive predictive value (PPV) 65%, negative predictive value (NPV) 75%. Regarding chemerin, a cut-off point level >43 ng/mL had a sensitivity of 75%, specificity of 72% AUROC 0.75, p = .001, CI 95% 0.61-0.89, PPV 51.7% NPV 87.8%, meaning that 51.7% of patients with chemerin levels >43 ng/mL have or will have preeclampsia. CONCLUSION: The NLR may help predict maternal-fetal complications in SLE pregnancy, constituting a marker of subclinical inflammation. Chemerin levels may be associated with preeclampsia. These biomarkers could improve the care of SLE patients with timely intervention of potential complications during pregnancy.

Statistical process control charts for better analysis of sequential data in psychology: The case of illusion of control experiments.

Illusion of control (IOC) is a bias in the judgment of personal success with implications to learning theories and health policies; some important questions in the investigation of IOC may be related to traditional measures in the field, namely self-assessment using Likert scales about the sense of control. Statistical process control (SPC) and Shewhart charts are methods developed to monitor and control industrial processes, never applied in psychological studies before. The present two studies investigated the use of the technique of Shewhart charts in the analysis of IOC. The purpose was to explore the use of SPC and Shewhart charts in the analysis of data sequences from psychological experiments; the objective was to analyze the results of reaction time (RT) data sequences plotted in SPC charts, in comparison with self-assessment judgments from an IOC task. Participants were 63 undergraduate students (Study 1) and 103 mine workers (Study 2) instructed to try to control a traffic light on a computer by pressing or not the keyboard. Higher probabilities of the successful outcome generated judgments of illusion and shifts (due to cognitive activity) in the charts of RT; lower probabilities resulted in null illusion and RT presented a random and stable profile. Patterns for different groups emerged in Shewhart charts. SPC can contribute to the analysis of the behavior of sequences of data in psychological studies, so that the charts indicate changes and patterns not detected by traditional ANOVA and other linear models.

Oncological outcomes in extended time intervals betweenpreoperative chemoradiotherapy with capecitabine and surgery inoperable rectal adenocarcinoma.

OBJECTIVE: To assess whether extended time intervals (8-12, 13-20 and >20 weeks) between the end of neoadjuvant chemoradiotherapy and surgery affect overall survival, disease-free survival. MATERIALS AND METHODS: Retrospective study in 120 patients with rectal adenocarcinoma without evidence of metastasis (T1-4/N0-2/M0) at the time of diagnosis that underwent surgery with curative intent after neoadjuvant chemoradiotherapy with capecitabine and obtained R0 or R1 resection between January 2010 to December 2014 at the National Cancer Institute of Peru. Dates were evaluated by Kaplan-Meier method, log- rank test and Cox regression analysis. RESULTS: Of the 120 patients, 70 were women (58%). The median age was 63(26-85) years. All received neoadjuvant chemoradiotherapy. No significant difference was found between the association of the median radial (0.6, 0.7 and 0.8 cm; p=0.826) and distal edge (3.0, 3.5 and 4.0 cm; p=0.606) with time interval groups and similarly the mean resected (18.8, 19.1 and 16.0; p=0.239) and infiltrated nodules (1.05, 1.29 and 0.41); p=0.585). The median follow-up time of overall survival and desease free survival was 40 and 37 months, respectively. No significant differences were observed in overall survival (79.0%, 74.6% and 71.1%; p=0.66) and disease-free survival (73.7%, 68.1% and 73.6%; p=0.922) according to the three groups studied at the 3-year of follow-up. CONCLUSIONS: We found that widening the time intervals between the end of neoadjuvant chemoradiotherapy and surgery at 24 weeks does not affect the overall survival, disease-free survival and pathological outcomes. It allows to extend the intervals of time for future studies that finally will define the best time interval for the surgery.

Oncological outcomes in extended time intervals between preoperative chemoradiotherapy with capecitabine and surgery in operable rectal adenocarcinoma / Resultados oncológicos en intervalos extendidos de tiempo entre quimioradioterapia preoperatoria con capecitabina y cirugía en adenocarcinoma rectal operable

Objective: To assess whether extended time intervals (8-12, 13-20 and >20 weeks) between the end of neoadjuvant chemoradiotherapy and surgery affect overall survival, disease-free survival. Materials and methods: Retrospective study in 120 patients with rectal adenocarcinoma without evidence of metastasis (T1-4/N0-2/M0) at the time of diagnosis that underwent surgery with curative intent after neoadjuvant chemoradiotherapy with capecitabine and obtained R0 or R1 resection between January 2010 to December 2014 at the National Cancer Institute of Peru. Dates were evaluated by Kaplan-Meier method, log- rank test and Cox regression analysis. Results: Of the 120 patients, 70 were women (58%). The median age was 63(26-85) years. All received neoadjuvant chemoradiotherapy. No significant difference was found between the association of the median radial (0.6, 0.7 and 0.8 cm; p=0.826) and distal edge (3.0, 3.5 and 4.0 cm; p=0.606) with time interval groups and similarly the mean resected (18.8, 19.1 and 16.0; p=0.239) and infiltrated nodules (1.05, 1.29 and 0.41); p=0.585). The median follow-up time of overall survival and desease free survival was 40 and 37 months, respectively. No significant differences were observed in overall survival (79.0%, 74.6% and 71.1%; p=0.66) and disease-free survival (73.7%, 68.1% and 73.6%; p=0.922) according to the three groups studied at the 3-year of follow-up. Conclusions: We found that widening the time intervals between the end of neoadjuvant chemoradiotherapy and surgery at 24 weeks does not affect the overall survival, disease-free survival and pathological outcomes. It allows to extend the intervals of time for future studies that finally will define the best time interval for the surgery

Objetivo: Evaluar si los intervalos de tiempo extendidos (8-12, 13-20 y >20 semanas) entre el fin de la quimioradioterapia neoadyuvante y la cirugía afectan la sobrevida global, y la sobrevida libre de enfermedad. Material y métodos: Estudio retrospectivo de 120 pacientes con adenocarcinoma rectal sin evidencia de metástasis (T1-4/N0-2/M0) al momento del diagnóstico que se sometieron a cirugía con intención curativa luego de quimioradioterapia neoadyuvante con capecitabina y tuvieron resección R0 o R1 entre enero 2010 y diciembre 2014 en el Instituto Nacioanal de Enfermedades Neoplásicas de Perú. El análisis se hizo con el método de Kaplan-Meier, la prueba log-rank y la regresión de Cox. Resultados: De 120 pacientes, 70 fueron mujeres (58%). La mediana de la edad fue 63 años (26-85 años). Todos recibieron quimioradioterapia neoadyuvante. No hubo diferencia significativa entre la asociación de las medianas de los bordes radial (0,6, 0.7 y 0,8 cm; p=0,826) y distal (3,0, 3,5 y 4,0 cm; p=0,606) con los intervalos de tiempo de los grupos y similarmente con la media de los ganglios resecados (18,8, 19,1 y 16,0; p=0,239) e infiltrados (1,05, 1,29 y 0,41; p=0,585). No se observaron diferencias significativas en sobrevida global (79,0%, 74,6% y 71,1%; p=0,66) y sobrevida libre de enfermedad (73,7%, 68,1% y 73,6%; p=0,922), en los tres grupos estudiados a 3 años de seguimiento. Conclusiones: Encontramos que aumentar los intervalos de tiempo entre el fin de la quimioradioterapia neoadyuvante y la cirugía hasta 24 semanas no afecta la sobrevida global, sobrevida libre de enfermedad ni los desenlaces patológicos. Esto permitiría extender los intervalos de tiempo en estudios futuros para definir el mejor intervalo de tiempo para la cirugía

Effects of solvent evaporation time on immediate adhesive properties of universal adhesives to dentin.

OBJECTIVE: To evaluate the microtensile bond strengths (µTBS) and nanoleakage (NL) of three universal or multi-mode adhesives, applied with increasing solvent evaporation times. METHODS: One-hundred and forty caries-free extracted third molars were divided into 20 groups for bond strength testing, according to three factors: (1) Adhesive - All-Bond Universal (ABU, Bisco, Inc.), Prime&Bond Elect (PBE, Dentsply), and Scotchbond Universal Adhesive (SBU, 3M ESPE); (2) Bonding strategy - self-etch (SE) or etch-and-rinse (ER); and (3) Adhesive solvent evaporation time - 5s, 15s, and 25s. Two extra groups were prepared with ABU because the respective manufacturer recommends a solvent evaporation time of 10s. After restorations were constructed, specimens were stored in water (37°C/24h). Resin-dentin beams (0.8mm(2)) were tested at 0.5mm/min (µTBS). For NL, forty extracted molars were randomly assigned to each of the 20 groups. Dentin disks were restored, immersed in ammoniacal silver nitrate, sectioned and processed for evaluation under a FESEM in backscattered mode. Data from µTBS were analyzed using two-way ANOVA (adhesive vs. drying time) for each strategy, and Tukey's test (α=0.05). NL data were computed with non-parametric tests (Kruskal-Wallis and Mann-Whitney tests, α=0.05). RESULTS: Increasing solvent evaporation time from 5s to 25s resulted in statistically higher mean µTBS for all adhesives when used in ER mode. Regarding NL, ER resulted in greater NL than SE for each of the evaporation times regardless of the adhesive used. A solvent evaporation time of 25s resulted in the lowest NL for SBU-ER. SIGNIFICANCE: Residual water and/or solvent may compromise the performance of universal adhesives, which may be improved with extended evaporation times.

Quasi-neutral theory of epidemic outbreaks.

Some epidemics have been empirically observed to exhibit outbreaks of all possible sizes, i.e., to be scale-free or scale-invariant. Different explanations for this finding have been put forward; among them there is a model for "accidental pathogens" which leads to power-law distributed outbreaks without apparent need of parameter fine tuning. This model has been claimed to be related to self-organized criticality, and its critical properties have been conjectured to be related to directed percolation. Instead, we show that this is a (quasi) neutral model, analogous to those used in Population Genetics and Ecology, with the same critical behavior as the voter-model, i.e. the theory of accidental pathogens is a (quasi)-neutral theory. This analogy allows us to explain all the system phenomenology, including generic scale invariance and the associated scaling exponents, in a parsimonious and simple way.

Location-aware access to hospital information and services.

Hospital workers are highly mobile; they are constantly changing location to perform their daily work, which includes visiting patients, locating resources, such as medical records, or consulting with other specialists. The information required by these specialists is highly dependent on their location. Access to a patient's laboratory results might be more relevant when the physician is near the patient's bed and not elsewhere. We describe a location-aware medical information system that was developed to provide access to resources such as patient's records or the location of a medical specialist, based on the user's location. The system is based on a handheld computer which includes a trained backpropagation neural-network used to estimate the user's location and a client to access information from the hospital information system that is relevant to the user's current location.