Network reliability analysis and intractability of counting diameter crystal graphs

Consider a stochastic network, where nodes are perfect but links fail independently, ruled by failure probabilities. Additionally, we are given distinguished nodes, called terminals, and a positive integer, called diameter. The event under study is to connect terminals by paths not longer than the given diameter. The probability of this event is called diameter-constrained reliability (DCR, for short). Since the DCR subsumes connectedness probability of random graphs, its computation belongs to the class of NP-Hard problems. The computational complexity for DCR is known for fixed values of the number of terminals k n and diameter d, being n the number of nodes in the network. The contributions of this article are two-fold. First, we extend the computational complexity of the DCR when the terminal size is a function of the number of nodes, this is, when k = k(n). Second, we state counting diameter-critical graphs belongs to the class of NP-Hard problems

Traditional medicines and ancestral knowledge. Embrace of the serpent (2015)

The film tells an epic journey where the confrontation of two different cultures is observed. In it two stories that occur in different historical times are intermingled. It begins with the meeting of Karamakate, a Cohihuano Indian, with a German anthropologist named Theo who is ill. He asks him to help him find the yakruna, a sacred plant, that grow where his people used to live and which he needs to cure his illness. After some doubts finally the Indian agrees to accompany him. Then the action takes place around 1940, when Karamakate is now an old Indian and has lost some of his memories. He meets Evans, an American ethnobotanist, who tells him that he is looking for the yakruna, a plant he met in a book written by a famous explorer who had been in those lands many years ago. The meeting reminds him of the one that happened approximately 30 years ago, and that still brings him back sad memories. The final scenes show, the decisions that Karamakate and Evans take against several dilemmas: to forgive or continue to distrust, to respect and try to understand the culture of the other or just use it for their benefit, to share the knowledge or let them die in oblivion.</p

Bounded Monte Carlo estimation of diameter-constrained network reliability

The d-diameter-constrained K-reliability (DCR) problem in networks is an extension of the classical problem of computing the K-reliability (CLR) where the subnetwork resulting from the failure of some edges is operational if and only if all nodes in a set of \201Cterminal nodes\201D K have pairwise distances not greater than a certain integer d. Computing the CLR is NP-hard which has motivated the development of simulation schemes, among which a family of Monte Carlo sampling plans that make use of upper and lower bounds to reduce the variance attained after drawing a given number of samples. The DCR is receiving increasing attention in contexts like video-conferencing and peer-to-peer networks; since it is an extension of the CLR it is also NP-hard. This paper presents Monte Carlo sampling plans based on bounds adapted to the DCR. These plans are described in detail focusing on their requirements and limitations. Test cases are presented evidencing how the diameter constraint and the terminal nodes set size affect the efficiency as well as the higher performance improvements attained by the best-performing methods in the context of DCR when compared to CLR

Virucidal action mechanism of alcohol and divalent cations against human adenovirus

Hygiene and disinfection practices play an important role at preventing spread of viral infections in household, industrial and clinical settings. Although formulations based on >70% ethanol are virucidal, there is a currently a need to reformulate products with much lower alcohol concentrations. It has been reported that zinc can increase the virucidal activity of alcohols, although the reasons for such potentiation is unclear. One approach in developing virucidal formulations is to understand the mechanisms of action of active ingredients and formulation excipients. Here, we investigated the virucidal activity of alcohol (40% w/v) and zinc sulfate (0.1% w/v) combinations and their impact on a human adenovirus (HAdV) using, nucleic acid integrity assays, atomic force microscopy (AFM) and transmission electron microscopy (TEM). We observed no difference in virucidal activity (5 log10 reduction in 60 min) against between an ethanol only based formulation and a formulation combining ethanol and zinc salt. Furthermore, TEM imaging showed that the ethanol only formulation produced gross capsid damage, whilst zinc-based formulation or formulation combining both ethanol and zinc did not affect HAdV DNA. Unexpectedly, the addition of nickel salt (5 mM NiCl2) to the ethanol-zinc formulation contributed to a weakening of the capsid and alteration of the capsid mechanics exemplified by AFM imaging, together with structural capsid damage. The addition of zinc sulfate to the ethanol formulation did not add the formulation efficacy, but the unexpected mechanistic synergy between NiCl2 and the ethanol formulation opens an interesting perspective for the possible potentiation of an alcohol-based formulation. Furthermore, we show that AFM can be an important tool for understanding the mechanistic impact of virucidal formulation

Bariatric surgery: evidence-based practical recommendations

[Resumen] La obesidad mórbida es, habitualmente, refractaria a los tratamientos convencionales, por lo que la modificación de hábitos dietéticos y de actividad física y/o el uso de fármacos consiguen pérdidas de peso parciales con habitual recuperación posterior. La cirugía bariátrica constituye una opción terapéutica para los casos de obesidad con elevado índice de masa corporal (IMC) asociada a comorbilidades, con buenos resultados a corto y largo plazo. El Grupo de Trabajo sobre Obesidad de la Sociedad Española de Endocrinología y Nutrición (GOSEEN) ha elaborado un documento con recomendaciones prácticas basadas en la evidencia para el tratamiento quirúrgico de la obesidad. La revisión se estructura en 3 partes. En la primera se definen los conceptos de obesidad y comorbilidades asociadas, los tratamientos médicos y sus resultados, las indicaciones y contraindicaciones para el tratamiento quirúrgico con los criterios de selección de los pacientes, el manejo pre y perioperatorio y la valoración de grupos especiales, como adolescentes y personas de edad avanzada. En la segunda parte se describen las distintas técnicas quirúrgicas, las vías de acceso y los resultados comparativos, las complicaciones tanto a corto como a largo plazo, la repercusión de la pérdida ponderal sobre las comorbilidades y los criterios para evaluar la efectividad de la cirugía. En la tercera parte se desarrolla el seguimiento postoperatorio, el control dietético en fases tempranas y más tardías tras la cirugía, y el calendario de control médico y analítico con la suplementación de los distintos macro y micronutrientes en función de la técnica quirúrgica empleada. Se incluye un apartado final sobre gestación y cirugía bariátrica, así como tablas y gráficos complementarios al texto desarrollado. La cirugía bariátrica sigue siendo un tratamiento discutido para la obesidad, pero los resultados en la corrección del exceso ponderal con mejoría en las patologías asociadas y en la calidad de vida confirman que puede ser el tratamiento de elección en pacientes seleccionados, con la técnica quirúrgica apropiada y con un correcto control pre y postoperatorio.[Abstract] Morbid obesity is usually refractory to conventional treatments. Consequently, weight that is lost by modifying diet and exercise and/or the use of drugs is usually later regained. Bariatric surgery constitutes a therapeutic option in obese patients with a high body mass index associated with comorbidities and achieves good results in both the short and the long term. The Obesity Working Group of the Spanish Society of Endocrinology and Nutrition has produced a document with practical, evidencebased recommendations for the surgical treatment of obesity. The review is structured in three parts. The first part defines the concepts of obesity and associated comorbidities, medical treatments, their results, and the indications and contraindications for surgical treatment, as well as the criteria for patient selection, pre- and perisurgical management, and assessment of special groups such as adolescents and the elderly. The second part discusses the different surgical techniques, approaches and comparative results, short- and long-term complications, the repercussions of weight loss on comorbidities, and the criteria for assessing the effectiveness of surgery. The third part discusses postsurgical follow-up, dietary control in the early and subsequent stages after surgery and the schedule for medical and laboratory follow-up, together with the different macro- and micronutrient supplements that should be used depending on the surgical technique employed. A final section is included on pregnancy and bariatric surgery, as well as tables and figures that complement the text. Although bariatric surgery continues to be a questionable treatment for obesity, the results correcting excess weight, with improvements in associated comorbidities and in quality of life, confirm that this option could be the treatment of choice in selected patients when the appropriate surgical technique and correct preand postoperative follow-up are employed

Genome-wide analyses reveal a potential role for the MAPT, MOBP, and APOE loci in sporadic frontotemporal dementia

Frontotemporal dementia (FTD) is the second most common cause of early-onset dementia after Alzheimer disease (AD). Efforts in the field mainly focus on familial forms of disease (fFTDs), while studies of the genetic etiology of sporadic FTD (sFTD) have been less common. In the current work, we analyzed 4,685 sFTD cases and 15,308 controls looking for common genetic determinants for sFTD. We found a cluster of variants at the MAPT (rs199443; p = 2.5 × 10−12, OR = 1.27) and APOE (rs6857; p = 1.31 × 10−12, OR = 1.27) loci and a candidate locus on chromosome 3 (rs1009966; p = 2.41 × 10−8, OR = 1.16) in the intergenic region between RPSA and MOBP, contributing to increased risk for sFTD through effects on expression and/or splicing in brain cortex of functionally relevant in-cis genes at the MAPT and RPSA-MOBP loci. The association with the MAPT (H1c clade) and RPSA-MOBP loci may suggest common genetic pleiotropy across FTD and progressive supranuclear palsy (PSP) (MAPT and RPSA-MOBP loci) and across FTD, AD, Parkinson disease (PD), and cortico-basal degeneration (CBD) (MAPT locus). Our data also suggest population specificity of the risk signals, with MAPT and APOE loci associations mainly driven by Central/Nordic and Mediterranean Europeans, respectively. This study lays the foundations for future work aimed at further characterizing population-specific features of potential FTD-discriminant APOE haplotype(s) and the functional involvement and contribution of the MAPT H1c haplotype and RPSA-MOBP loci to pathogenesis of sporadic forms of FTD in brain cortex

New insights into the genetic etiology of Alzheimer's disease and related dementias

Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

Common variants in Alzheimer’s disease and risk stratification by polygenic risk scores

Funder: Funder: Fundación bancaria ‘La Caixa’ Number: LCF/PR/PR16/51110003 Funder: Grifols SA Number: LCF/PR/PR16/51110003 Funder: European Union/EFPIA Innovative Medicines Initiative Joint Number: 115975 Funder: JPco-fuND FP-829-029 Number: 733051061Genetic discoveries of Alzheimer's disease are the drivers of our understanding, and together with polygenetic risk stratification can contribute towards planning of feasible and efficient preventive and curative clinical trials. We first perform a large genetic association study by merging all available case-control datasets and by-proxy study results (discovery n = 409,435 and validation size n = 58,190). Here, we add six variants associated with Alzheimer's disease risk (near APP, CHRNE, PRKD3/NDUFAF7, PLCG2 and two exonic variants in the SHARPIN gene). Assessment of the polygenic risk score and stratifying by APOE reveal a 4 to 5.5 years difference in median age at onset of Alzheimer's disease patients in APOE ɛ4 carriers. Because of this study, the underlying mechanisms of APP can be studied to refine the amyloid cascade and the polygenic risk score provides a tool to select individuals at high risk of Alzheimer's disease