Earthquake Arrival Association with Backprojection and Graph Theory

The association of seismic wave arrivals with causative earthquakes becomes progressively more challenging as arrival detection methods become more sensitive, and particularly when earthquake rates are high. For instance, seismic waves arriving across a monitoring network from several sources may overlap in time, false arrivals may be detected, and some arrivals may be of unknown phase (e.g., P- or S-waves). We propose an automated method to associate arrivals with earthquake sources and obtain source locations applicable to such situations. To do so we use a pattern detection metric based on the principle of backprojection to reveal candidate sources, followed by graph-theory-based clustering and an integer linear optimization routine to associate arrivals with the minimum number of sources necessary to explain the data. This method solves for all sources and phase assignments simultaneously, rather than in a sequential greedy procedure as is common in other association routines. We demonstrate our method on both synthetic and real data from the Integrated Plate Boundary Observatory Chile (IPOC) seismic network of northern Chile. For the synthetic tests we report results for cases with varying complexity, including rates of 500 earthquakes/day and 500 false arrivals/station/day, for which we measure true positive detection accuracy of > 95%. For the real data we develop a new catalog between January 1, 2010 - December 31, 2017 containing 817,548 earthquakes, with detection rates on average 279 earthquakes/day, and a magnitude-of-completion of ~M1.8. A subset of detections are identified as sources related to quarry and industrial site activity, and we also detect thousands of foreshocks and aftershocks of the April 1, 2014 Mw 8.2 Iquique earthquake. During the highest rates of aftershock activity, > 600 earthquakes/day are detected in the vicinity of the Iquique earthquake rupture zone

Diseño Flexible como Oportunidad de Adquisición

Navies around the world adopt different ways of acquiring ships. Using a single large prime contractor, placing individual contracts for design, build and integration, or employing a state-owned shipyard with external support are all procurement options that we see today.‘Flexibility’ in warship design is normally perceived as provision of extra empty space, weight and power, which could be filled with new equipment at some point in the future. However, this idea can be extended to describe a design that achieves true flexibility by exploiting the synergy with different acquisition strategies, adaptability allowing a choice of balanced capability and options for incremental acquisition to control cost and risk profiles. This leads to a design that will deliver a class of warships able to meet the evolving roles and threats throughout its life, whilst not introducing additional risk and cost into the programmes of any modern Navy around the world which adopts it.To achieve this flexibility BMT have created a single base design with multiple configurations; a warship with a functional arrangement that is able to be tailored to meet the specific requirements and budget of each Navy, minimising the initial cost penalty in a programme, and maximising commonality. It also allows for modular construction techniques which not only apply to single yard construction, including small and medium shipyards, but enables blocks to be built in several shipyards.This paper will describe the underlying considerations behind this flexibility, including incremental acquisition as a cost mitigation in procurement programmes, and the different potential partnership models between shipyard, designer and integrator in effective acquisition programmes which work to the strengths of each party.Las armadas nacionales alrededor del mundo adoptan diferentes maneras de adquirir barcos. El uso de un solo contratista principal de gran tamaño, la asignación de contratos individuales para el diseño, la construcción y la integración, o el empleo de un astillero de propiedad estatal con apoyo externo son todas opciones de adquisición que vemos hoy en día.La "flexibilidad" en el diseño de buques de guerra se percibe normalmente como la provisión de espacios vacíos, peso y potencia adicionales, que podrían ser utilizados con nuevo equipo en algún momento en el futuro. Sin embargo, esta idea puede ampliarse con el fin describir un diseño que logre una verdadera flexibilidad  al explotar la sinergia entre diferentes estrategias de adquisición y adaptabilidad permitiendo la posibilidad de una capacidad equilibrada y opciones para la adquisición incremental con el fin de controlar los perfiles de costos y riesgos. Esto conduce a un diseño que ofrecerá un tipo de buques de guerra capaces de cumplir con los cambiantes roles y amenazas a lo largo de su vida útil, sin generar riesgos y costos adicionales en los programas de cualquier Marina moderna alrededor del mundo que los adopte.Con el fin lograr esta flexibilidad, BMT ha creado un diseño de base única con múltiples configuraciones; un buque de guerra con un arreglo funcional que puede ser adaptado para cumplir con los requisitos específicos y el presupuesto de cada Armada, minimizando la penalización del costo inicial en un programa y maximizando la homogeneidad. También permite las técnicas de construcción modular que no sólo se aplican a la construcción de astilleros únicos, incluidos los astilleros pequeños y medianos, sino que permite la construcción de bloques en varios astilleros.Este documento describirá las consideraciones subyacentes detrás de esta flexibilidad, incluyendo la adquisición incremental como una forma de mitigar costos en los programas de adquisición y los diferentes modelos potenciales de asociación entre astillero, diseñador e integrador en programas efectivos de adquisición que trabajen enfocándose en las fortalezas de cada parte

The implementation of chlamydia screening: a cross-sectional study in the south east of England

Background England's National Chlamydia Screening Programme (NCSP) provides opportunistic testing for under 25 year-olds in healthcare and non-healthcare settings. The authors aimed to explore relationships between coverage and positivity in relation to demographic characteristics or setting, in order to inform efficient and sustainable implementation of the NCSP. Methods The authors analysed mapped NCSP testing data from the South East region of England between April 2006 and March 2007 inclusive to population characteristics. Coverage was estimated by sex, demographic characteristics and service characteristics, and variation in positivity by setting and population group. Results Coverage in females was lower in the least deprived areas compared with the most deprived areas (OR 0.48; 95% CI 0.45 to 0.50). Testing rates were lower in 20 1324-year-olds compared with 15 1319-year-olds (OR 0.69; 95% CI 0.67 to 0.72 for females and OR 0.67; 95% CI 0.64 to 0.71 for males), but positivity was higher in older males. Females were tested most often in healthcare services, which also identified the most positives. The greatest proportions of male tests were in university (27%) and military (19%) settings which only identified a total of 11% and 13% of total male positives respectively. More chlamydia-positive males were identified through healthcare services despite fewer numbers of tests. Conclusions Testing of males focused on institutional settings where there is a low yield of positives, and limited capacity for expansion. By contrast, the testing of females, especially in urban environments, was mainly through established healthcare services. Future strategies should prioritise increasing male testing in healthcare settings

Missing data in randomized controlled trials testing palliative interventions pose a significant risk of bias and loss of power: a systematic review and meta-analyses

Objectives To assess the risk posed by missing data (MD) to the power and validity of trials evaluating palliative interventions. Study Design and Setting A systematic review of MD in published randomized controlled trials (RCTs) of palliative interventions in participants with life-limiting illnesses was conducted, and random-effects meta-analyses and metaregression were performed. CENTRAL, MEDLINE, and EMBASE (2009-2014) were searched with no language restrictions. Results One hundred and eight RCTs representing 15,560 patients were included. The weighted estimate for MD at the primary endpoint was 23.1% (95% confidence interval [CI] 19.3, 27.4). Larger MD proportions were associated with increasing numbers of questions/tests requested (odds ratio [OR] , 1.19; 95% CI 1.05, 1.35) and with longer study duration (OR, 1.09; 95% CI 1.02, 1.17). Meta-analysis found evidence of differential rates of MD between trial arms, which varied in direction (OR, 1.04; 95% CI 0.90, 1.20; I 2 35.9, P = 0.001). Despite randomization, MD in the intervention arms (vs. control) were more likely to be attributed to disease progression unrelated to the intervention (OR, 1.31; 95% CI 1.02, 1.69). This was not the case for MD due to death (OR, 0.92; 95% CI 0.78, 1.08). Conclusion The overall proportion and differential rates and reasons for MD reduce the power and potentially introduce bias to palliative care trials

Validation of Three Body Composition Techniques with a Comparison of Ultrasound Abdominal Fat Depths against an Octopolar Bioelectrical Impedance Device

International Journal of Exercise Science 5(3) : 205-213, 2012. The aims of this study were to cross-validate three clinical-grade measures of body composition, using an octopolar Bioelectrical Impedance (BIA), an ultrasound analyzer (US) and Air-Displacement Plethysmography (ADP) and second to compare the US scans of total abdominal, subcutaneous and visceral fat depths (mm) against the trunk percent fat (%BF) from the octopolar BIA. Twenty-six college-aged (22.9 ± 1.35 years) men (n = 18) and women (n = 8) volunteered to participate in this study. Body composition was assessed using BIA (total and by segments), ADP and US. In addition, total abdominal, subcutaneous and visceral fat layers were measured using the US. All measurements were done in accordance with manufacturers’ guidelines. The %BF comparing the three clinical grade machines were all significantly correlated and no significant differences were found using a 1-way ANOVA. All three fat depths were significantly correlated to the trunk fat % via BIA, while significant differences were found for the 1-way ANOVA. A Tukey post-hoc test showed significant differences between the BIA trunk %BF and both subcutaneous and visceral US fat depths. Having valid ways to measure body composition and visceral fat that is accessible in terms of being transportable, cost effective, and simple to use, should become a part of preventive medicine

Management education in Latin America and the Caribbean.

This paper examines some issues relating to the development in Latin America and the Caribbean of the managerial expertise that underpins the modernisation of library and information services. It reports on part of a joint IFLA/FID project, principally funded by the UNESCO Participation Programme, and reviews results from two surveys: Schools of Librarianship and Information Sciences in the region provided data on the priorities they attach to elements of their management curriculum, and teaching methods; and employers commented on their awareness of modern management techniques, their management development needs and approaches, and their perceptions of the management education available. The results of the two surveys are compared and considered, and some proposals are made for addressing issues. Whilst the Schools appear to be meeting the employers key requirements, there is still some degree of mismatch between employers expectations and Schools priorities, but the Schools are open to change and a constructive dialogue is advocated. It is also suggested that more attention should be given to staff development and the provision of supporting continuing education programmes to raise the level of management knowledge and expertise. Iinternational organisations should consider encouraging the production and exchange of teaching materials. A major challenge for the Schools will be to overcome the traditionally rigid disciplinary boundaries within Universities to collaborate on new course developments

Mid-Infrared Optical Frequency Combs based on Difference Frequency Generation for Molecular Spectroscopy

Mid-infrared femtosecond optical frequency combs were produced by difference frequency generation of the spectral components of a near-infrared comb in a 3-mm-long MgO:PPLN crystal. We observe strong pump depletion and 9.3 dB parametric gain in the 1.5 \mu m signal, which yields powers above 500 mW (3 \mu W/mode) in the idler with spectra covering 2.8 \mu m to 3.5 \mu m. Potential for broadband, high-resolution molecular spectroscopy is demonstrated by absorption spectra and interferograms obtained by heterodyning two combs.Comment: 11 pages, 8 figure