Infrastructure Hardening: A Competitive Co-evolutionary Methodology Inspired by Neo-Darwinian Arms Races

The world is increasingly dependent on critical infrastructures such as the electric power grid, water, gas, and oil transport systems, which are susceptible to cascading failures that can result from a few faults. Due to the combinatorial complexity in the search spaces involved, most traditional search techniques are inappropriate for identifying these faults and potential protections against them. This paper provides a computational methodology employing competitive coevolution to simultaneously identify low-effort, high-impact faults and corresponding means of hardening infrastructures against them. A power system case study provides empirical evidence that our proposed methodology is capable of identifying cost effective modifications to substantially improve the fault tolerance of critical infrastructures

Blueprint for Iteratively Hardening Power Grids Employing Unified Power Flow Controllers

A stable electricity supply is vital for modern society. However, many parts of our power transmission grid are operating near their operational limits. Such stressed systems are vulnerable to cascading failures, where a few small faults can induce a cascade of failures potentially leading to a major blackout The unified power flow controller (UPFC), the most powerful highspeed, semi-conductor based power flow device, can be used as a theoretical model to study how these devices can be used to improve power grid resilience. The blueprint presented here can be used to iteratively identify critical weaknesses in power grids and to recommend a means of fixing these weaknesses via the installation of UPFCs. This approach to hardening the power transmission grid will make it less prone to blackouts and better able to forestall or reduce the severity of unavoidable blackouts

UPFC Control Employing Gradient Descent Search

Increasing demand coupled with limitations on new construction indicate that existing power transmission must be better controlled in order to continue reliable operation. Recent advances in FACTS devices provide a mechanism to better control power flow on the transmission network. One particular device, the unified power flow controller (UPFC), holds the most promise for maintaining operation even when the system has suffered partial failure (either naturally occurring, due to human error, or a malicious attack). In addition to the capital cost, the primary obstacles to widespread UPFC use are the combined problems of selecting the most cost effective locations for installation and maintaining proper control of them once installed. In this paper we list evidence that gradient descent search based on load-flow computation is more realistic and accurate than many of the optimization techniques currently in use. We then demonstrate that gradient descent search can be used to select control points that improve system fault tolerance more than those found by the max-flow technique. In addition, we demonstrate that the size of the system being computed and the number of computations is bounded and is practical for real time control

Identificación, serotipificación y determinación del perfil de sensibilidad de Salmonella enterica aisladas de cloacas de tortugas de orejas rojas (Trachemys sp) en cautiverio, Perú

The aim of this study was to identify, serotype and determine the sensitivity profile of Salmonella enterica strains isolated from red-eared slider turtles (Trachemys sp) from two breeding centres in Lima, Peru, through cloacal swabs. The samples were isolated using tetrathionate enrichment broth, specific media such as Salmonella-Shigella agar and xylose lysine deoxycholate agar. The identification was made through biochemical tests. Serotyping through the recognition of somatic (O) and flagellar (H) antigens of the Kauffmann-White system, and the determination of sensitivity using the Kirby Bauer diffusion disk test. The results showed that 6.1% (4/66) of Salmonella enterica isolates were obtained, identifying the serotypes Salmonella Saintpaul and Salmonella Infantis. Antibacterial sensitivity tests indicated differences between strains, showing 100% sensitivity against nalidixic acid, norfloxacin and enrofloxacin and less for streptomycin, sulfamethoxazole + trimethoprim, chloramphenicol and amoxicillin + clavulanic acid. The results show the potential risk to public health involved in raising these turtles as potential pets.El presente estudio tuvo por objetivo identificar, serotipificar y determinar el perfil de sensibilidad de cepas de Salmonella enterica aisladas de tortugas de orejas rojas (Trachemys sp) provenientes de dos centros de crianza en Lima, Perú, a través de hisopados cloacales. Las muestras se aislaron por medio del caldo de enriquecimiento tetrationato, medios específicos como agar Salmonella-Shigella y agar xilosa lisina desoxicolato. La identificación se hizo mediante pruebas bioquímicas. La serotipificación a través del reconocimiento de antigenos somáticos (O) y flagelares (H) del sistema Kauffmann-White, y la determinación de la sensibilidad por medio de la prueba de disco difusión Kirby Bauer. Se obtuvo un 6.1% (4/66) de aislados de Salmonella enterica, identificándose los serotipos Salmonella Saintpaul y Salmonella Infantis. Las pruebas de sensibilidad a antibacterianos indicaron diferencias entre cepas, mostrando 100% de sensibilidad frente al ácido nalidíxico, norfloxacína y enrofloxacina y menor a estreptomicina, sulfametoxasol + trimetropin, cloranfenicol y amoxicilina + ácido clavulánico. Los resultados muestran el potencial riesgo para la salud pública que implica la crianza de estas tortugas como potenciales mascotas

Cognitive and mood functioning in borderline and schizotypal personality disorders

Research suggests many shared clinical features across individuals with Schizotypal Personality Disorder (SPD) and Borderline Personality Disorder (BPD), including problems with attention/ executive functioning and mood. Therefore, aspects of these areas of functioning were compared in SPD and BPD to better characterize their respective difficulties. BPD, SPD, and healthy control (HC) participants were administered measures of cognitive and mood functioning. Compared with healthy controls, SPD patients performed significantly worse on aspects of the Delayed-Matching- to-Sample task, a measure of short-term visual memory abilities; however, the individuals with BPD did not differ from healthy controls. Neither of the patient groups differed from HC’s on measures of processing speed or planning. With regard to mood functioning, the BPD group exhibited significantly higher levels of affective disturbance (e.g., sadness, fear, anger) compared with the SPD patients and HCs. Overall, findings suggest different patterns of fronto-subcortical weakness in each patient group. While SPD patients exhibited relative weakness with short-term memory, BPD patient performance on such measures did not reveal relative weakness compared with HCs but did implicate problems with mood

Structural neural networks subserving oculomotor function in first-episode schizophrenia

BACKGROUND: Smooth pursuit and antisaccade abnormalities are well documented in schizophrenia, but their neuropathological correlates remain unclear. METHODS: In this study, we used statistical parametric mapping to investigate the relationship between oculomotor abnormalities and brain structure in a sample of first-episode schizophrenia patients (n = 27). In addition to conventional volumetric magnetic resonance imaging, we also used magnetization transfer ratio, a technique that allows more precise tissue characterization. RESULTS: We found that smooth pursuit abnormalities were associated with reduced magnetization transfer ratio in several regions, predominantly in the right prefrontal cortex. Antisaccade errors correlated with gray matter volume in the right medial superior frontal cortex as measured by conventional magnetic resonance imaging but not with magnetization transfer ratio. CONCLUSIONS: These preliminary results demonstrate that specific structural abnormalities are associated with abnormal eye movements in schizophrenia

A public health response to the methamphetamine epidemic: the implementation of contingency management to treat methamphetamine dependence

BACKGROUND: In response to increases in methamphatemine-associated sexually transmitted diseases, the San Francisco Department of Public Health implemented a contingency management (CM) field program called the Positive Reinforcement Opportunity Project (PROP). METHODS: Methamphetamine-using men who have sex with men (MSM) in San Francisco qualified for PROP following expressed interest in the program, provision of an observed urine sample that tested positive for methamphetamine metabolites and self-report of recent methamphetamine use. For 12 weeks, PROP participants provided observed urine samples on Mondays, Wednesdays and Fridays and received vouchers of increasing value for each consecutive sample that tested negative to metabolites of methamphetamine. Vouchers were exchanged for goods and services that promoted a healthy lifestyle. No cash was provided. Primary outcomes included acceptability (number of enrollments/time), impact (clinical response to treatment and cost-effectiveness as cost per patient treated). RESULTS: Enrollment in PROP was brisk indicating its acceptability. During the first 10 months of operation, 143 men sought treatment and of these 77.6% were HIV-infected. Of those screened, 111 began CM treatment and averaged 15 (42%) methamphetamine-free urine samples out of a possible 36 samples during the 12-week treatment period; 60% completed 4 weeks of treatment; 48% 8 weeks and 30% 12 weeks. Across all participants, an average of $159 (SD =$165) in vouchers or 35.1% of the maximum possible ($453) was provided for these participants. The average cost per participant of the 143 treated was$800. CONCLUSION: Clinical responses to CM in PROP were similar to CM delivered in drug treatment programs, supporting the adaptability and effectiveness of CM to non-traditional drug treatment settings. Costs were reasonable and less than or comparable to other methamphetamine outpatient treatment programs. Further expansion of programs like PROP could address the increasing need for acceptable, feasible and cost-effective methamphetamine treatment in this group with exceptionally high rates of HIV-infection

SPEM dysfunction and general schizotypy as measured by the SSQ: a controlled study

Abstract Background SPEM dysfunction is a well-known phenomenon in schizophrenia. The principal aim of the present study was to examine whether SPEM dysfunction is already observable in subjects scoring high on a specific measure of schizotypy (SSQ General Schizotypy) that was selected because of its intimate relationship with schizophrenic prodromal unfolding. Methods Applying ANOVAs, we determined the relationship of subjects' scores on SSQ General Schizotypy and eye movements elicited by targets of different speed. We also examined whether there exists an association between our schizotypy measure and pupil size. Results We found more SPEM dysfunction in subjects scoring high on SSQ General Schizotypy than in subjects scoring average on that factor, irrespective of the speed of the target. No relationship was found between baseline pupil size and General Schizotypy. Conclusion The present study provides additional evidence that SPEM dysfunction is associated with schizotypic features that precede the onset of schizophrenia and is already observable in general population subjects that show these features

Análisis filogenético de cepas de Escherichia coli aisladas de crías de alpacas (Vicugna pacos) con diarrea en la sierra central del Perú

The aim of this study was to determine the phylogenetic groups of Escherichia coli isolated from alpacas with diarrhoea. The presence of E. coli was determined in 150 samples of diarrheal faeces collected from young alpacas from the central highlands of Peru, and the distribution of phylogenetic groups was determined by the Clermont method. E. coli was present in 79.3% (119/150) of animals with diarrhoea. The strains were classified into phylogenetic groups A, B1, B2 and D, which showed a frequency of 13.5% (16/119), 65.5% (78/119), 1.68% (2/119) and 19.33% (11/23), respectively. Moreover, 21% (25/119) of isolated strains of E. coli belonged to phylogenetic groups B2 and D, mainly extraintestinal pathogenic strains, and 79% (94/119) to groups B1 and A, which are mainly commensal strains.El objetivo del presente estudio fue la determinación de grupos filogenéticos de Escherichia coli obtenidos de alpacas con diarrea. Se determinó la presencia de E. coli en 150 muestras de heces diarreicas recolectadas de crías de alpaca de la sierra central del Perú, y se determinó la distribución de los grupos filogenéticos mediante el método de Clermont. E. coli estuvo presente en el 79.3% (119/150) de los animales con diarrea, pudiendo clasificarse en los grupos filogenéticos A, B1, B2 y D, los cuales mostraron una frecuencia de 13.5% (16/119), 65.5% (78/119), 1.68% (2/119) y 19.33% (23/119), respectivamente. El 21% (25/119) de cepas aisladas de E. coli pertenecen a los grupos filogenéticos B2 y D, principalmente cepas patógenas extraintestinales, y el 79% (94/119) a los grupos B1 y A, que son principalmente cepas comensales

Pathogens involved in fatal cases of diarrhea in young alpacas in the central highlands of Peru

Se evaluó la presencia de enteropatógenos en 60 crías de alpacas de 1 a 2.5 meses de edad con cuadros mortales de diarrea de las regiones de Pasco y Junín, Perú. Se tomaron muestras de heces para determinar la frecuencia de Escherichia coli y Salmonella sp mediante microbiología convencional, de parásitos gastrointestinales por las técnicas de sedimentación y flotación, y de Criptosporidium sp mediante la técnica de Ziehl Neelsen Modificado. Además, se evidenció la presencia de antígenos virales con la ayuda de un kit comercial de inmunocromatografía. Se identificó E. coli (80%), coronavirus (53.3%), Eimeria sp (43.3%), Nematodirus sp (40%), rotavirus (36.6%), Criptosporidium sp (20%) y Salmonella sp (18.3%). Asimismo, se determinó que el 38.3% de los animales presentó los tres tipos de patógenos, mientras que el 23.3% presentó asociación de bacterias y parásitos, y el 11.7% presentó asociación de virus y bacterias.The presence of enteric pathogens was assessed in 60 young alpacas (1 to 2.5 months old) raised in Pasco and Junin, Peru that died due to diarrhea. Stool samples were collected to determine the frequency of Escherichia coli and Salmonella sp by conventional microbiology, gastrointestinal parasites by the sedimentation and flotation techniques, and Cryptosporidium sp by the modified Ziehl Neelsen technique. Besides, the presence of viral antigens using an immunochromatography commercial kit. The results showed the presence of E. coli (80%), coronavirus (53.3%), Eimeria sp (43.3%), Nematodirus sp (40%), rotavirus (36.6%), Criptosporidium sp (20%) and Salmonella sp (18.3%). Moreover, it was determined that 38.3% of the animals presented the three types of pathogens, while 23.3% had association of bacteria and parasites, and 11.7% showed association of virus and bacteria