Credit in a Tiered Payments System

Payments systems are typically characterized by some degree of tiering, with upstream firms (clearing agents) providing settlement accounts to downstream institutions that wish to clear and settle payments indirectly in these systems (indirect clearers). Clearing agents provide their indirect clearers with an essential input (clearing and settlement services), while also competing directly with them in the retail market for payment services. The authors construct a model of a clearing agent with an indirect clearer to examine the clearing agent's incentives to lever off its upstream position to gain a competitive advantage in the retail payment services market. The model demonstrates that a clearing agent can attain this competitive advantage by raising the indirect clearer's costs, but that the incentive to raise these costs is mitigated by credit risk to the clearing agent from the provision of uncollateralized overdrafts to its indirect clearer. The results suggest that tiered payments systems, which require clearing agents to provide overdraft facilities to their indirect clearers, may result in a more competitive retail payment services market.Financial institutions; Financial services; Market structure and pricing; Payment, clearing, and settlement systems

Predictive Behavior of a Computational Foot/Ankle Model through Artificial Neural Networks

Computational models are useful tools to study the biomechanics of human joints. Their predictive performance is heavily dependent on bony anatomy and soft tissue properties. Imaging data provides anatomical requirements while approximate tissue properties are implemented from literature data, when available. We sought to improve the predictive capability of a computational foot/ankle model by optimizing its ligament stiffness inputs using feedforward and radial basis function neural networks. While the former demonstrated better performance than the latter per mean square error, both networks provided reasonable stiffness predictions for implementation into the computational model

¿Habrá pensiones?

El futuro demográfico de México es el envejecimiento; y de todos los temas de la vejez, el que más atención atrae, aparece más en los medios y más se discute políticamente es el de las pensiones de retiro. Por sus circunstancias históricas el sistema de pensiones ha resultado fragmentado y desordenado; en él se registran poco más de 100 instituciones públicas federales y estatales (Auditoría Superior de la Federación, 2013:60), conociéndose poco de los municipios y de planes privados que actualmente pudieran superar los mil. El sistema tiene cobertura limitada, al abarcar a trabajadores asalariados y urbanos y excluir al medio rural y al sector informal: sólo 40% de la población económicamente activa (PEA) está cubierta y únicamente la quinta parte de la población de 65 años y más está pensionada. Es inequitativo, al otorgar privilegios a sindicatos y grupos con capacidad política, mientras los beneficios para la mayoría de otros pensionados son insuficientes, y es también ajeno a la solidaridad social y económica que debería caracterizar a la seguridad social. Tan relevantes deficiencias, sin embargo, no son notorias, y lo que acapara la atención y preocupación es la insostenible carga financiera y económica que las pensiones representan convirtiéndolas en un riesgo económico, social y político

Evaluación y tendencias de los sistemas de pensiones en México

Los sistemas de pensiones coinciden en manifestar serios problemas. Su creciente costo es impagable y representa un riesgo para el futuro social y económico del país. Los diagnósticos sobre la crisis y lo que hay que hacer crean controversia. Las opiniones y las acciones responden más a intereses creados y no a los objetivos de la seguridad social y de las pensiones. Este libro pretende ofrecer caminos en busca soluciones, de modo independiente y con rigor académico, en formato accesible, en capítulos cortos con conclusiones, en lenguaje sencillo, evitando gráficas, estadísticas complicadas, notas de pié de página o bibliografías extensas. En la seguridad social, y particularmente en las pensiones, ha predominado la concesión de los beneficios sin considerar adecuadamente costos futuros, transformaciones del mercado laboral o efectos del envejecimiento demográfico. Como la crisis se configura como pesada carga financiera, una opción para atenuar ha sido el ahorro en cuentas individuales con administración privada para financiar el retiro. Sin embargo, se muestra que en las actuales condiciones, tal medida resulta ineficaz, es agravante de las finanzas públicas y deja de lado la necesaria interrelación demográfica, económica, social, laboral y el cuidado de la salud, como elementos de políticas públicas. Sin posibilidades de generar un crecimiento económico sostenido y con mejores estructuras productivas,el mercado de trabajo es vulnerable. Han decrecido los puestos laborales en el sector estructurado y formal, mientras aumenta la informalidad, la precariedad en el empleo, los bajos ingresos y también la emigración hacia los Estados Unidos y otros países. En este contexto las aportaciones definidas tienen un panorama poco favorable ya que no se prevén mejoras en la seguridad para el retiro, los niveles de cobertura, los costos de administración y el balance fiscal. La reforma a la seguridad social debe considerar nuevos pactos sociales, así como una nueva institucionalidad

Prevalence of Alcohol Consumption and Hazardous Drinking, Tobacco and Drug use in urban Tanzania, and Their associated Risk Factors.

Evidence suggests substance abuse in Tanzania is a growing public health problem. A random sample of 899 adults aged 15-59 in two urban sites of differing levels of poverty surveyed alcohol, tobacco and illicit substance use. Rates of substance use were 17.2%. 8.7% and 0.8% for alcohol, tobacco and cannabis, respectively. Living in the less affluent area was associated with higher lifetime rates of tobacco and alcohol use. Substance use is less prevalent in Tanzania than in richer countries, but lifetime consumption is higher in poorer areas. The association of substance use with a range of socio-economic factors warrants further research

Evaluation of Xpert® MTB/RIF and ustar easyNAT™ TB IAD for diagnosis of tuberculous lymphadenitis of children in Tanzania : a prospective descriptive study

Fine needle aspiration biopsy has become a standard approach for diagnosis of peripheral tuberculous lymphadenitis. The aim of this study was to compare the performance of Xpert MTB/RIF and Ustar EasyNAT TB IAD nucleic acid amplification assays, against acid-fast bacilli microscopy, cytology and mycobacterial culture for the diagnosis of TB lymphadenitis in children from a TB-endemic setting in Tanzania.; Children of 8 weeks to 16 years of age, suspected of having TB lymphadenitis, were recruited at a district hospital in Tanzania. Fine needle aspirates of lymph nodes were analysed using acid-fast bacilli microscopy, liquid TB culture, cytology, Xpert MTB/RIF and EasyNAT. Latent class analysis and comparison against a composite reference standard comprising "culture and/or cytology" was done, to assess the performance of Xpert MTB/RIF and EasyNAT for the diagnosis of TB lymphadenitis.; Seventy-nine children were recruited; 4 were excluded from analysis. Against a composite reference standard of culture and/or cytology, Xpert MTB/RIF and EasyNAT had a sensitivity and specificity of 58 % and 93 %; and 19 % and 100 % respectively. Relative to latent class definitions, cytology had a sensitivity of 100 % and specificity of 94.7 %.; Combining clinical assessment, cytology and Xpert MTB/RIF may allow for a rapid and accurate diagnosis of childhood TB lymphadenitis. Larger diagnostic evaluation studies are recommended to validate these findings and on Xpert MTB/RIF to assess its use as a solitary initial test for TB lymphadenitis in children

Systematic review and meta-analysis: prevalence of alcohol use among young people in eastern Africa.

OBJECTIVE: Systematic review and meta-analysis of published studies of alcohol use among young people (age 15-24 years) in eastern Africa to estimate prevalence of alcohol use and determine the extent of use of standardised screening questionnaires in alcohol studies. METHODS: Five databases (MEDLINE, EMBASE, Global Health, Africa-wide, and PsycINFO) were searched for publications until 30th June 2013. Results were summarised using the guidelines on preferred reporting items for systematic reviews and meta-analyses (PRISMA) and on quality assessment using the modified quality assessment tool for systematic reviews of observational studies (QATSO). Heterogeneity was assessed using the I(2) statistic (DerSimonian-Laird). RESULTS: We identified 2785 potentially relevant studies, of which 56 were eligible for inclusion. Only two studies (4%) used the standardised Alcohol Use Disorder Identification Test (AUDIT) questionnaire, and six studies (13%) used the Cut down, Annoyed, Guilt, Eye opener (CAGE) questionnaire. The reported median prevalence of alcohol use was ever-use 52% [interquartile range (IQR): 20-58%], use in the last month 28% (IQR: 17-37%), use in the last year 26% (IQR: 22-32%), and problem drinking as defined by CAGE or AUDIT 15% (IQR: 3-36%). We observed high heterogeneity between studies, with the highest prevalence of ever use of alcohol among university students (82%; 95%CI: 79-85%) and female sex workers (66%; 95%CI: 58-74%). Current use was most prevalent among male sex workers (69%; 95%CI: 63-75%). CONCLUSIONS: Reported alcohol use and problem drinking were common among diverse groups of young people in eastern Africa, indicating the urgent need for alcohol-focused interventions in this population. Few studies have used standardised alcohol screening questionnaires. Epidemiological research to investigate alcohol-focused interventions in young people should aim to apply such questionnaires that should be validated for use in this population

Alternative splicing variants in breast cancer

Abstract Cancer is considered a genetic disease that incurs in uncontrolled and disproportional growth of the cells with distinct characterizing hallmarks. Breast Cancer (BC) is the most common type of cancer and a leading cause in death of women therefore remaining a target of study. Hereditary breast cancer (HBC) is tightly associated with mutations in tumor suppressor genes such as the BRCA genes. These are highly penetrant genes involved in the DNA damage response. BRCA1 codes for a multifunctional protein that, when mutated with a pathogenic variant impairs many pathways in the cell. Genetic tests have increasingly been asked for these genes, many resulting in variants of unknown significance (VUS). VUS represent a concern as their biological impact is not known thus, their study is of vital interest. Several are the factors involved in their study. These include mRNA splicing assays, seen as sometimes these VUS lead to alternative splicing of the gene, thus identified as splice variants (SV). Our work is divided in two tasks, firstly our aim was to identify potential SV in different cell lines commonly used in BC research, using one non-tumorigenic (MCF-10A) for comparative purposes and three distinct tumorigenic cell lines (MCF-7, MDA-MB-231 and SK-BR-3). We performed mRNA splicing analysis for the exon 11 (highly alternative spliced region) of the BRCA1 gene using PCR-based techniques. The results obtained for this task indicate that no SV was found in this exon for these in vitro models. In the second part of our study, we cultured an MCF-10A cell line previously cloned by our group with a VUS of the BRCA1 gene located in the exon 11, using CRISPR-Cas9, and applied the same method used for mRNA splicing analysis of the other cells. First, we had to confirm that the cells indeed carried the VUS, which was confirmed establishing a new homozygous in vitro model, and only then applied the method, which, after analysis, apparently indicated that this is not a SV. For further confirmation off the results, we performed direct RNA sequencing by nanopore. Unfortunately, this data is still under analysis and the results are not presented here.Resumo O cancro é considerado uma doença genética que incorre num crescimento descontrolado e desproporcional de células que apresentam características distintas. O cancro da mama é o tipo de cancro mais comum e uma das principais causas de morte das mulheres, permanecendo por isso um alvo de estudo para a comunidade científica. O cancro hereditário da mama está frequentemente associado a mutações em genes supressores de tumores, tais como os genes BRCA. Estes são genes altamente penetrantes envolvidos nas vias de reparação do DNA. O gene BRCA1 codifica para uma proteína multifuncional que, quando mutada com uma variante patogénica, prejudica muitas vias na célula. Testes genéticos têm sido cada vez mais solicitados para estes genes, muitos resultando em variantes de significado desconhecido (VUS). VUS representam uma preocupação, uma vez que o seu impacto biológico não é conhecido, sendo o seu estudo de interesse vital. Vários são os fatores envolvidos no seu estudo incluindo ensaios de análise do splicing pelo mRNA. Estes devem-se ao facto de que por vezes estas VUS despoletam mecanismos de splicing alternativo do gene, sendo por isso identificadas com variantes de splicing (SV). O nosso trabalho consistiu em duas partes. O primeiro objectivo foi identificar potenciais SV em diferentes linhas celulares muito utilizadas na investigação do cancro da mama, utilizando uma linha não tumoral (MCF-10A) para comparação, e três linhas tumorais distintas (MCF-7, MDA-MB-231 e SK-BR-3). Foi realizada a análise de splicing para o exão 11 (região alvo de muito splicing alternativo) do gene BRCA1, utilizando técnicas de PCR. Os resultados obtidos indicam que nenhuma SV se encontra presente neste exão para estas linhas. Na segunda parte do estudo, utilizou-se a linha celular (MCF-10A) anteriormente clonada, pelo nosso grupo, com uma VUS do gene BRCA1 localizada no exão 11, utilizando CRISPR-Cas9, aplicando-se de seguida o mesmo método de análise de splicing. Confirmou-se que as células continham a VUS em homozigotia estabelecendo-se um novo modelo in vitro. Os resultados indicaram também que esta VUS não se trata de uma SV. Para confirmação destes resultados, procedemos à sequenciação direta do RNA por Nanopore. Infelizmente, estes dados estão ainda sob análise, não estando os resultados aqui apresentados

IMPROVED CAPABILITY OF A COMPUTATIONAL FOOT/ANKLE MODEL USING ARTIFICIAL NEURAL NETWORKS

Computational joint models provide insight into the biomechanical function of human joints. Through both deformable and rigid body modeling, the structure-function relationship governing joint behavior is better understood, and subsequently, knowledge regarding normal, diseased, and/or injured function is garnered. Given the utility of these computational models, it is imperative to supply them with appropriate inputs such that model function is representative of true joint function. In these models, Magnetic Resonance Imaging (MRI) or Computerized Tomography (CT) scans and literature inform the bony anatomy and mechanical properties of muscle and ligamentous tissues, respectively. In the case of the latter, literature reports a wide range of values or average values with large standard deviations due to the inability to measure the mechanical properties of soft tissues in vivo. This makes it difficult to determine which values within the published literature to assign to computational models, especially patient-specific models. Therefore, while the use of published literature serves as a reasonable first approach to set up a computational model, a means of improving the supplied input data was sought. This work details the application of artificial neural networks (ANNs), specifically feedforward and radial basis function networks, to the optimization of ligament stiffnesses for the improved performance of pre- and post-operative, patient-specific foot/ankle computational models. ANNs are mathematical models that utilize learning rules to determine relationships between known sets of inputs and outputs. Using knowledge gained from these training data, the ANN may then predict outputs for similar, never‑before-seen inputs. Here, an optimal network of each ANN type was found, per mean square error and correlation data, and then both networks were used to predict optimal ligament stiffnesses corresponding to a single patient’s radiographic measurements. Both sets of predictions were ultimately supplied to the patient-specific computational models, and the resulting kinematics illustrated an improvement over the existing models that utilized literature-assigned stiffnesses. This research demonstrated that neural networks are a viable means to hone in on ligament stiffnesses for the overall objective of improving the predictive ability of a patient-specific computational model