Earthquake Mitigation by Blast Densification

This paper presents a case study of blast densification of a site underlain by a loose, saturated, natural sand deposit. Densification was performed to mitigate the risk of liquefaction from earthquake-induced ground vibrations. The work was implemented as part of the design-build construction of the Marine Corps Reserve Training Center at the Westover Air Reserve Base in Chicopee, Massachusetts. Following review of preliminary subsurface data at the site, the contractor retained a team to design and implement ground improvement by blast densification. The team, led by a geotechnical engineering firm, included a blaster, a driller, and a cone penetrometer testing firm. The team performed the analyses, design, implementation and post-densification testing to carry out and document the effectiveness of the blast densification. The paper presents the densification program and comparison of the pre- and post blasting data including settlement results. The project duration including pre-blasting evaluation, design, implementation, and post-blasting evaluation was less than two months. This demonstrates that deep blasting can be successfully implemented as part of fast-track, design-build procurement to execute a complex ground improvement program. It also demonstrates that while the technique is not commonly used, it is sufficiently well understood to provide a flexible and cost effective alternative to the more commonly used ground improvement methods under the right conditions

Pre- and intraoperative variables affecting early outcomes in elderly patients undergoing pancreaticoduodenectomy

AbstractBackgroundConflicting data exist regarding the safety of pancreatic resections in elderly patients. In this study we compared early complication and mortality rates between patients younger and older than 80 years of age who underwent pancreaticoduodenectomy using a validated national database.MethodsThe National Surgical Quality Improvement Program (NSQIP) database for 2005–2009 was used for this retrospective analysis. The primary outcome measures for our analysis were 30-day postoperative mortality, major complication rate and overall complication rate.ResultsA total of 6293 patients who underwent PD for any cause were included in the analysis. Of these, 9.4% were aged ≥80 years. The incidence of 30-day mortality was significantly higher in patients aged ≥80 years (6.3%) than in those aged <80 years (2.7%). Older patients were also noted to have higher rates of overall complications and serious complications. On multivariate analysis, age, ASA (American Society of Anesthesiologists) classification, reduced functional status, history of dyspnoea, and need for intraoperative transfusion were risk factors associated with the occurrence of overall complications, serious complications and postoperative mortality.ConclusionsThis study shows that age among other factors is a determinant of postoperative morbidity and mortality following PD

Universal light quark mass dependence and heavy-light meson spectroscopy

Clean predictions are presented for all the spin-averaged heavy-light meson spectroscopies. A new symmetry is identified wherein the energy eigenstates have a universal dependence on both the light and heavy quark masses. This universality is used in an efficient analysis of these mesons within the QCD string/flux tube picture. Unique predictions for all the D, D_s, B, and B_s type mesons in terms of just four measured quantities.Comment: REVTeX4, 6 pages, 9 eps figure

Prokaryotic abundance and heterotrophic metabolism in the deep Mediterranean Sea

A synthesis of field data carried out in the Mediterranean Sea are presented, aimed at contributing to the knowledge of three prokaryotic-mediated processes and their implications on the Carbon cycle. The distribution of exoenzymatic activities, secondary production and respiration rates was studied together with the prokaryotic abundances. Particular attention was paid to the meso- and bathypelagic layers which play an important role in the Mediterranean carbon cycle. The study is noteworthy because of its large spatial scale spanning the entire Mediterranean Sea over 4 years. In addition, two Atlantic stations in front of the Gibraltar Strait were investigated. The longitudinal distribution of prokaryotic activities and abundance along the MED showed different trends along the depthlayers. In particular, higher exoenzymatic rates were detected in the Eastern basin compared to the Western one; carbon respiration rate showed patterns variable with the sampling periods in the epipelagic and bathypelagic layers, while a consistent Westwards decreasing trend at the mesopelagic layers occurred. Specific enzyme activities per cell showed high values in the deepest layers for leucine aminopeptidase. Comparison with Carbon respiration rate data collected before the 2000s showed changing patterns of microbial heterotrophic processes in the Mediterranean Sea

Reduction of the QCD string to a time component vector potential

We demonstrate the equivalence of the relativistic flux tube model of mesons to a simple potential model in the regime of large radial excitation. We make no restriction on the quark masses; either quark may have a zero or finite mass. Our primary result shows that for fixed angular momentum and large radial excitation, the flux tube/QCD string meson with a short-range Coulomb interaction is described by a spinless Salpeter equation with a time component vector potential V(r) = ar - k/r.Comment: RevTeX4, 10 pages, 3 eps figure

Template for Developing Guidelines for the Evaluation of the Clinical Efficacy of Psychophysiological Interventions

An essential function of both the Association for Applied Psychophysiology and Biofeedback (AAPB) and the Society for Neuronal Regulation (SNR) is the systematic evaluation of psychophysiological interventions that have been developed for the treatment of medical and psychiatric disorders. In order to address scientific concerns regarding the efficacy of specific clinical applications of biofeedback, these two societies formed and Efficacy Task Force. The process to be used in the assessment of treatment efficacy, specificity and clinical utility is presented in the form of a template that will serve as the foundation for a series of scientific reviews and practice guidlines to be published by both societies