Evolutionary Spiking Neural Networks for Solving Supervised Classification Problems.

This paper presents a grammatical evolution (GE)-based methodology to automatically design third generation artificial neural networks (ANNs), also known as spiking neural networks (SNNs), for solving supervised classification problems. The proposal performs the SNN design by exploring the search space of three-layered feedforward topologies with configured synaptic connections (weights and delays) so that no explicit training is carried out. Besides, the designed SNNs have partial connections between input and hidden layers which may contribute to avoid redundancies and reduce the dimensionality of input feature vectors. The proposal was tested on several well-known benchmark datasets from the UCI repository and statistically compared against a similar design methodology for second generation ANNs and an adapted version of that methodology for SNNs; also, the results of the two methodologies and the proposed one were improved by changing the fitness function in the design process. The proposed methodology shows competitive and consistent results, and the statistical tests support the conclusion that the designs produced by the proposal perform better than those produced by other methodologies.

Exploiting electronic strategies to stabilize a planar tetracoordinate carbon in cyclic aromatic hydrocarbons.

A new approach to stabilize compounds containing a planar tetracoordinate carbon (ptC), embedded in aromatic hydrocarbons, is presented herein. This is achieved by using ligands that promote the formation of a 3c-2e σ-bond with the ptC under two conditions: without altering the sp2 hybridization of the aromatic carbons; and containing empty orbitals perpendicular to the aromatic ring to participate in the aromatic π-electronic delocalization.

Acute pulmonary embolism detection with ventilation/perfusion SPECT combined with full dose CT: what is the best option? / SPECT/TC de ventilación-perfusión pulmonar en el diagnóstico del tromboembolismo pulmonar agudo

Aim. To compare diagnostic accuracy of Ventilation/Perfusion (V/P) single-photon emission computed tomography (SPECT) combined with simultaneous full-dose CT with a hybrid SPECT/CT scanner versus planar ventilation/perfusion (V/P) SPECT and CT angiography (CTA) in patients suspected with acute pulmonary embolism (PE). Methods. Between 2009 and 2011, consecutive patients suspected of acute PE were referred for V/P SPECT/CT (reviewed board approved study). A contrast agent was administered to patients who had no contraindications. Non-contrast V/P SPECT/CT was performed on the remaining patients. All patients were followed-up for at least 3 months. Results. A total of 314 patients were available during the study period, with the diagnosis of PE confirmed in 70 (22.29%) of them. The overall population sensitivity and specificity was 90.91% and 92.44%, respectively for V/P SPECT, 80% and 99.15%, respectively, for CTA, and 95.52% and 97.08% for V/P SPECT/CT. SPECT/CT performed better than V/P SPECT (AUC differences=0.0419, P=0.0043, 95% CI; 0.0131-0.0706) and CTA (AUC differences=0.0681, P=0.0208, 95% CI; 0.0103-0.1259)). Comparing imaging modalities when contrast agent could be administered, sensitivity and specificity increased and V/P SPECT/CT was significantly better than CTA (AUC differences=0.0681, P=0.0208, 95% CI; 0.0103-0.1259) and V/P SPECT (AUC differences=0.0659, P=0.0052, 95% CI; 0.0197-0.1121). In case of non-contrast enhancement, there was non-significant increase of specificity. Secondary findings on CT impacted patient management in 14.65% of cases. Conclusion. Our study shows that combined V/P SPECT/CT scanning has a higher diagnostic accuracy for detecting acute PE than V/P SPECT and CTA alone. When feasible, V/P SPECT/CT with contrast enhancement is the best option (AU)

Objetivo del estudio. Valorar la exactitud diagnóstica de la SPECT/TC de ventilación-perfusión (V/P) pulmonar de alta dosis mediante un equipo híbrido SPECT/TC frente a la SPECT de V/P pulmonar y a la angiografía por TC (CTA) en pacientes con sospecha de tromboembolismo pulmonar (TEP) agudo. Metodología. Entre 2009 y 2011, se estudiaron de forma consecutiva con SPECT/TC de V/P pulmonar los pacientes con sospecha de TEP agudo que acudieron a nuestro centro (estudio aprobado por el comité de ética hospitalaria). A los pacientes que no presentaban contraindicaciones se les administró contraste yodado (CI) por vía intravenosa. En el resto se realizó un estudio SPECT/TC de V/P pulmonar sin CI. Los pacientes fueron seguidos durante un período de 3 meses. Resultados. Se estudiaron un total de 314 pacientes. En 70 (22,29%) se confirmó el diagnóstico de TEP. La sensibilidad y especificidad para la población global fue: 90,91 y 92,44% respectivamente para la SPECT de V/P; 80 y 99.15% para la CTA; y 95.52 y 97.08% para la SPECT/TC de V/P pulmonar. La SPECT/TC presentaba una exactitud diagnóstica superior a la SPECT de V/P (diferencias AUC=0,0419; p=0,0043; IC95%: 0,0131-0,0706) y la CTA (diferencias AUC=0,0681, p=0,0208; IC95%: 0,0131-0,1259). Comparando las diferentes modalidades cuando se administró CI, observamos un aumento de la sensibilidad y la especificidad de la SPECT/TC de V/P superior a la CTA (diferencias AUC=0,0681; p=0,0208; IC95%: 0,0131-0,1259) y a la SPECT de V/P (diferencias AUC=0,0659; p=0,0052; IC95%: 0,0197-0,1121). En el caso de no administrar CI se observó un aumento no estadísticamente significativo de la especificidad. Los hallazgos secundarios de la TC provocaron un cambio en el manejo del paciente en un 14,65% de los casos. Conclusión. Nuestro estudio demuestra que el estudio combinado SPECT/TC de V/P pulmonar tiene una mayor exactitud diagnóstica para detectar el TEP agudo que la SPECT de V/P pulmonar o la CTA por sí solos. Cuando es factible, la SPECT/TC de V/P pulmonar con CI es la mejor opción diagnóstica (AU)

Acute pulmonary embolism detection with ventilation/perfusion SPECT combined with full dose CT: What is the best option?

AIM: To compare diagnostic accuracy of Ventilation/Perfusion (V/P) single-photon emission computed tomography (SPECT) combined with simultaneous full-dose CT with a hybrid SPECT/CT scanner versus planar ventilation/perfusion (V/P) SPECT and CT angiography (CTA) in patients suspected with acute pulmonary embolism (PE). METHODS: Between 2009 and 2011, consecutive patients suspected of acute PE were referred for V/P SPECT/CT (reviewed board approved study). A contrast agent was administered to patients who had no contraindications. Non-contrast V/P SPECT/CT was performed on the remaining patients. All patients were followed-up for at least 3 months. RESULTS: A total of 314 patients were available during the study period, with the diagnosis of PE confirmed in 70 (22.29%) of them. The overall population sensitivity and specificity was 90.91% and 92.44%, respectively for V/P SPECT, 80% and 99.15%, respectively, for CTA, and 95.52% and 97.08% for V/P SPECT/CT. SPECT/CT performed better than V/P SPECT (AUC differences=0.0419, P=0.0043, 95% CI; 0.0131-0.0706) and CTA (AUC differences=0.0681, P=0.0208, 95% CI; 0.0103-0.1259)). Comparing imaging modalities when contrast agent could be administered, sensitivity and specificity increased and V/P SPECT/CT was significantly better than CTA (AUC differences=0.0681, P=0.0208, 95% CI; 0.0103-0.1259) and V/P SPECT (AUC differences=0.0659, P=0.0052, 95% CI; 0.0197-0.1121). In case of non-contrast enhancement, there was non-significant increase of specificity. Secondary findings on CT impacted patient management in 14.65% of cases. CONCLUSION: Our study shows that combined V/P SPECT/CT scanning has a higher diagnostic accuracy for detecting acute PE than V/P SPECT and CTA alone. When feasible, V/P SPECT/CT with contrast enhancement is the best option.

Quadrupedal Robot Locomotion: A Biologically Inspired Approach and Its Hardware Implementation.

A bioinspired locomotion system for a quadruped robot is presented. Locomotion is achieved by a spiking neural network (SNN) that acts as a Central Pattern Generator (CPG) producing different locomotion patterns represented by their raster plots. To generate these patterns, the SNN is configured with specific parameters (synaptic weights and topologies), which were estimated by a metaheuristic method based on Christiansen Grammar Evolution (CGE). The system has been implemented and validated on two robot platforms; firstly, we tested our system on a quadruped robot and, secondly, on a hexapod one. In this last one, we simulated the case where two legs of the hexapod were amputated and its locomotion mechanism has been changed. For the quadruped robot, the control is performed by the spiking neural network implemented on an Arduino board with 35% of resource usage. In the hexapod robot, we used Spartan 6 FPGA board with only 3% of resource usage. Numerical results show the effectiveness of the proposed system in both cases.

Selected Swine viral pathogens in indoor pigs in Spain. Seroprevalence and farm-level characteristics.

A serosurvey on porcine reproductive and respiratory syndrome virus (PRRSV), swine influenza virus (SIV), Aujeszky's disease virus gE protein (ADV gE), porcine parvovirus (PPV) and porcine circovirus type 2 (PCV2) was carried out in Spanish pig herds. The serosurvey consisted of two studies. First, a retrospective study assessed the proportion of seropositive boar, sow and fattening pig herds and their seroprevalences to PRRSV, SIV, ADV gE and PPV from 2003 to 2005 and to PCV2 from 2000 to 2005. Such information was obtained from routine serologic analyses from two veterinary diagnostic laboratory services. Second, a cross-sectional study in sow and fattening pig herds from 44 farms (without vaccination interferences on serologic analyses) was performed to provide information on seroprevalences and co-seropositivity to PRRSV, SIV, ADV gE and PCV2 (PPV was excluded because of widespread vaccination) and to elucidate their relationships with farm characteristics, management and productive parameters. Similar seroprevalences were observed in both studies, although some variations were obtained, probably because of vaccination schedules, number of tested sera, sampling age and regional variations. Percentage of PRRSV and SIV seropositive herds was over 85% for sows, around 80% for fatteners and around 50% for boar studs. The proportion of ADV gE seropositive sow herds decreased from 41% to 30% between 2003 and 2005, whereas such decrease was from 41% to 33% in fattening pig herds and from 13% to 4% in boar studs PCV2 antibodies were widespread as well as those against PPV; in the latter case, if antibodies were elicited by infection and/or vaccination was not assessed. Concurrent presence of PCV2, PRRSV and SIV antibodies was found in 89% and 66% sow and fattening herds, respectively. No statistical associations were obtained between seroprevalences or co-seropositivity and farm characteristics, management or productive parameters.

[Emergence of Microsporum audouinii and Trichophyton tonsurans as causative organisms of tinea capitis in the Dominican Republic]. / Tinea capitis. Emergencia de Microsporum audouinii y Trichophyton tonsurans en la República Dominicana.

BACKGROUND: Tinea capitis affects mainly children. The frequency and causative organism vary from region to region. OBJECTIVES: To provide epidemiological and mycological data on tinea capitis collected in urban and rural areas of the Dominican Republic. METHODS: Samples were obtained from 118 patients with tinea capitis. Sixty-three of these were from 2 schools in urban areas of the Dominican capital Santo Domingo (53%) and 55 were from rural schools on the border with Haiti (47%). RESULTS: The study included 84 boys (71. 18%) and 34 girls (28. 81%). The urban sample comprised mainly boys (84. 12%). The most represented age ranges were 6 to 8 years (47. 45%), 3 to 5 years (24. 59%), and 9 to 11 years (16. 94%). Microsporum audouinii (39. 68%), Trichophyton tonsurans (23. 80%), Microsporum canis (19. 04%), and Trichophyton violaceum (1. 58%) were isolated from children in urban areas, whereas T. tonsurans (87%) and Trichophyton mentagrophytes (2%) were isolated from those in rural areas. Overall, T. tonsurans (61. 16%), M. audouinii (24. 27%), and M canis (11. 65%) were the most frequently isolated causative organisms, whereas T. violaceum and T. mentagrophytes were rarely reported. CONCLUSIONS: In urban areas of the Dominican Republic, tinea capitis was found mainly in boys, but in rural areas it was evenly distributed among boys and girls. The emergence of M. audouinii and an increase in T. tonsurans were found while M. canis continued to be present at lower frequencies. On the rural border with Haiti, there was a significant predominance of T. tonsurans.

Tinea capitis. Emergencia de Microsporum audouinii y Trichophyton tonsurans en la República Dominicana / Emergence of Microsporum audouinii and Trichophyton tonsurans as Causative Organisms of Tinea Capitis in the Dominican Republic

Antecedentes: Las tiñas de la cabeza predominan en los niños, con una frecuencia y etiología variables en diferentes partes del mundo. Objetivos: Comunicar los datos epidemiológicos y micológicos de tiña del cuero cabelludo observados en la zona urbana y rural de la República Dominicana. Metodología: Se estudiaron 118 muestras de pacientes con diagnóstico de tiña de la cabeza en la República Dominicana, 63 de dos escuelas urbanas en la capital Santo Domingo (53%) y 55 de escuelas rurales en la frontera dominico-haitiana (47%). Resultados: Se estudiaron 84 varones (71,18%) y 34 mujeres (28,81%). En la zona urbana predominó en los varones (84,12%). La edad con mayores porcentajes fue entre 6 y 8años (47,45%), de 3 y 5 años (24,59%) y 9 y 11 años (16,94%). En la zona urbana se aislaron M. audouinii (39,68%), T. tonsurans (23,80%), M. canis (19,04%) y T. violaceum (1,58%) y en la zona rural T. tonsurans (87%) y T. mentagrophytes (2%) y globalmente T. tonsurans (61,16%), M. audouinii (24,27%) y M. canis (11,65%) y rara vez T. violaceum y T. mentagrophytes. Conclusiones: En la República Dominicana, en la zona urbana, la tiña de la cabeza predomina en los varones y en la zona rural tiene una frecuencia similar en ambos sexos. Se detectó una emergencia por M. audouinii, un incremento de Trichophyton tonsurans, y una estabilidad con frecuencia más baja de M. canis. En la zona rural y la frontera con Haití hay un predominio significativo de T. tonsurans (AU)

Background: Tinea capitis affects mainly children. The frequency and causative organism vary from region to region. Objectives: To provide epidemiological and mycological data on tinea capitis collected in urban and rural areas of the Dominican Republic. Methods: Samples were obtained from 118 patients with tinea capitis. Sixty-three of these were from 2 schools in urban areas of the Dominican capital Santo Domingo (53%) and 55 were from rural schools on the border with Haiti (47%). Results: The study included 84 boys (71.18%) and 34 girls (28.81%). The urban sample comprised mainly boys (84.12%). The most represented age ranges were 6 to 8 years (47.45%), 3 to 5 years (24.59%), and 9 to 11 years (16.94%). Microsporum audouinii (39.68%), Trichophyton tonsurans (23.80%), Microsporum canis (19.04%), and Trichophyton violaceum (1.58%) were isolated from children in urban areas, whereas T. tonsurans (87%) and Trichophyton mentagrophytes (2%) were isolated from those in rural areas. Overall, T. tonsurans (61.16%), M. audouinii (24.27%), and M canis (11.65%) were the most frequently isolated causative organisms, whereas T. violaceum and T. mentagrophytes were rarely reported. Conclusions: In urban areas of the Dominican Republic, tinea capitis was found mainly in boys, but in rural areas it was evenly distributed among boys and girls. The emergence of M. audouinii and an increase in T. tonsurans were found while M. canis continued to be present at lower frequencies. On the rural border with Haiti, there was a significant predominance of T. tonsurans (AU)

Chronological study of Mycoplasma hyopneumoniae infection, seroconversion and associated lung lesions in vaccinated and non-vaccinated pigs.

A field trial was conducted to study Mycoplasma hyopneumoniae (Mh) infection dynamics by nested polymerase chain reaction (nPCR) and serology in pigs of a farm affected by enzootic pneumonia (EP). Moreover, correlation of Mh detection at different respiratory tract sites with presence of EP gross and microscopic lung lesions was assessed. These parameters were studied and compared between vaccinated (two doses at 1 and 3 weeks of age versus one dose at 6 weeks of age) and non-vaccinated pigs. Animals were monitored from birth to slaughter by nPCR from nasal swabs and by serology. From 3 to 22 weeks of age, an average of three pigs per treatment and per batch were necropsied (n = 302). The remaining pigs were sent to the slaughter (n = 103). Nasal, bronchial and tonsillar swabs were taken from the necropsied/slaughtered pigs; gross and microscopic EP-suggestive lung lesions were also assessed. Single and double vaccination resulted in earlier seroconversion and higher percentage of Mh seropositive pigs compared to control group. At slaughter, double vaccinated pigs showed lower percentage of EP-compatible gross lung lesions and lower Mh prevalence at upper respiratory tract sites (nasal cavity and tonsil) than control pigs.

Obesity, adiponectin and inflammation as predictors of new-onset diabetes mellitus after kidney transplantation.

The high incidence of new-onset diabetes mellitus after transplantation (NODAT) suggests the need to find new factors to explain the pathogenesis. Our objectives were (1) to confirm that low levels of pre-transplant adiponectin are an independent risk factor for the development of NODAT in a larger transplanted population; (2) to analyze whether adiponectin is a better predictor of NODAT than other inflammatory markers (C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha) and pregnancy-associated plasma protein A (PAPP-A)) and (3) to assess the relationship between obesity, inflammatory markers and NODAT. One hundred ninety-nine non-diabetic patients (128 men; age: 53 +/- 11 years; body mass index (BMI) 24.98 +/- 3.76 kg/m2) were included. Pre-transplant plasma glucose, insulin, adiponectin, CRP, TNF-alpha, IL-6 and PAPP-A were measured. Forty-five patients developed NODAT. Patients with NODAT had a greater BMI (p = 0.005). Adiponectin was lower (p < 0.001) and CRP higher (p = 0.032) in patients with NODAT. Multivariate logistic regression and Cox analysis showed that the calcineurin inhibitor used, pre-transplant BMI and adiponectin were predictors of NODAT. ROC analysis showed that an adiponectin concentration of 11.4 microg/mL had a significant negative prediction for NODAT risk (sensitivity: 81% and specificity: 70%). Of the inflammatory markers studied, adiponectin proved to be an independent predictor of NODAT.

Sow porcine circovirus type 2 (PCV2) status effect on litter mortality in postweaning multisystemic wasting syndrome (PMWS).

Previous studies have described a "litter effect" associated with mortality in postweaning multisystemic wasting syndrome (PMWS) affected farms. The main objective of this study was to evaluate litter mortality in different PMWS affected farms and to characterize it in relation to three variables of the sow: parity, porcine circovirus type 2 (PCV2) infectious status and PCV2 antibody titres. The study was performed in seven farms that experienced PMWS in nurseries and/or fattening areas. Fifteen sows from each farm were randomly selected from the same farrowing batch. Serum samples were analyzed for antibodies to PCV2 and for genomic detection of PCV2. Four piglets from each sow (60 piglets per farm) were selected and ear-tagged at birth. Out of 420 initial piglets, 104 (25%) died. Sixty three of them (60%) were necropsied, and 40 (63%) diagnosed as PMWS based on case definition criteria. Our results show that sow PCV2 viremia was significantly related to piglet mortality since more piglets per litter died from viremic than from non-viremic sows. Additionally, a significantly greater proportion of animals died from sows that had low antibody titres against PCV2 (39% vs. 18% from sows with medium to high antibody titres). The present study, of exploratory nature, confirms previous results and further characterizes the so called "litter effect" by establishing that the sow PCV2 status had a significant effect on litter mortality in PMWS affected farms.

Persistent left ventricular dysfunction after cocaine treatment in rabbits.

The present study was undertaken to determine whether the diminished cardiac performance associated with cocaine administration persists after the drug has been eliminated from the body. Cocaine (5 or 10 mg/kg iv) was administered to conscious (n = 7) or pentobarbital-anesthetized (n = 7) rabbits, respectively. Seven conscious and seven anesthetized control rabbits received the saline vehicle. Two and one-half hours later, the hearts were removed from the animals and perfused under cocaine-free conditions. Left ventricular (LV) contractility was evaluated by plotting steady-state LV systolic and diastolic pressures as a function of LV end-diastolic volume (preload). LV systolic performance was diminished in a dose-related manner in hearts isolated from cocaine-treated rabbits, but was statistically different from control only at the higher cocaine dose (P < 0.05). In a second set of experiments, hearts (n = 6) were isolated, and their LV function was evaluated before, during, and after cocaine exposure. In these experiments, cocaine was added to the perfusate in increments to produce concentrations of 5, 10, and 15 mg/liter. After LV function was evaluated at the highest cocaine dose, cocaine-free perfusion conditions were restored, and LV function was reevaluated. In these experiments, cocaine produced a dose-dependent decrease in LV function that readily reversed when cocaine-free perfusion was reinstated. We conclude that cocaine diminishes LV contractility, and that the diminished cardiac performance may not readily reverse after in vivo exposure. Moreover, the rapid restoration of cardiac performance after exposure to cocaine in vitro suggests that the mechanism operating in vivo involves more than a simple direct action on the myocyte. Catecholamine cardiotoxicity does not appear to be a primary factor.