The Structure of Conserved Charges in Open Spin Chains

We study the local conserved charges in integrable spin chains of the XYZ type with nontrivial boundary conditions. The general structure of these charges consists of a bulk part, whose density is identical to that of a periodic chain, and a boundary part. In contrast with the periodic case, only charges corresponding to interactions of even number of spins exist for the open chain. Hence, there are half as many charges in the open case as in the closed case. For the open spin-1/2 XY chain, we derive the explicit expressions of all the charges. For the open spin-1/2 XXX chain, several lowest order charges are presented and a general method of obtaining the boundary terms is indicated. In contrast with the closed case, the XXX charges cannot be described in terms of a Catalan tree pattern.Comment: 22 pages, harvmac.tex (minor clarifications and reference corrections added

Sound archaeology: terminology, Palaeolithic cave art and the soundscape

This article is focused on the ways that terminology describing the study of music and sound within archaeology has changed over time, and how this reflects developing methodologies, exploring the expectations and issues raised by the use of differing kinds of language to define and describe such work. It begins with a discussion of music archaeology, addressing the problems of using the term ‘music’ in an archaeological context. It continues with an examination of archaeoacoustics and acoustics, and an emphasis on sound rather than music. This leads on to a study of sound archaeology and soundscapes, pointing out that it is important to consider the complete acoustic ecology of an archaeological site, in order to identify its affordances, those possibilities offered by invariant acoustic properties. Using a case study from northern Spain, the paper suggests that all of these methodological approaches have merit, and that a project benefits from their integration

Visit-to-visit and 24-h blood pressure variability: association with endothelial and smooth muscle function in African Americans

The purpose of this study was to investigate the association of visit-to-visit and 24-h blood pressure (BP) variability with markers of endothelial injury and vascular function. We recruited 72 African Americans who were non-diabetic, non-smoking and free of cardiovascular (CV) and renal disease. Office BP was measured at three visits and 24-h ambulatory BP monitoring was conducted to measure visit-to-visit and 24-h BP variability, respectively. The 5-min time-course of brachial artery flow-mediated dilation and nitroglycerin-mediated dilation were assessed as measures of endothelial and smooth muscle function. Fasted blood samples were analyzed for circulating endothelial microparticles (EMPs). Significantly lower CD31+CD42− EMPs were found in participants with high visit-to-visit systolic blood pressure (SBP) variability or high 24-h diastolic blood pressure (DBP) variability. Participants with high visit-to-visit DBP variability had significantly lower flow-mediated dilation and higher nitroglycerin-mediated dilation at multiple time-points. When analyzed as continuous variables, 24-h mean arterial pressure variability was inversely associated with CD62+ EMPs; visit-to-visit DBP variability was inversely associated with flow-mediated dilation normalized by smooth muscle function and was positively associated with nitroglycerin-mediated dilation; and 24-h DBP variability was positively associated with nitroglycerin-mediated dilation. All associations were independent of age, gender, body mass index and mean BP. In conclusion, in this cohort of African Americans visit-to-visit and 24-h BP variability were associated with measures of endothelial injury, endothelial function and smooth muscle function. These results suggest that BP variability may influence the pathogenesis of CV disease, in part, through influences on vascular health

Acoustic and Laser Doppler Anemometer Results for Confluent and 12-Lobed E(exp 3) Mixer Exhaust Systems for Subsonic Jet Noise Reduction

The research described in this report has been funded by NASA Glenn Research Center as part of the Advanced Subsonic Technologies (AST) initiative. The program operates under the Large Engine Technologies (LET) as Task Order #3 1. Task Order 31 is a three year research program divided into three subtasks. Subtask A develops the experimental acoustic and aerodynamic subsonic mixed flow exhaust system databases. Subtask B seeks to develop and assess CFD-based aero-acoustic methods for subsonic mixed flow exhaust systems. Subtask B relies on the data obtained from Subtask A to direct and calibrate the aero-acoustic methods development. Subtask C then seeks to utilize both the aero-acoustic data bases developed in Subtask A and the analytical methods developed in Subtask B to define improved subsonic mixed-flow exhaust systems. The mixed flow systems defined in Subtask C will be experimentally demonstrated for improved noise reduction in a scale model aero-acoustic test conducted similarly to the test performed in Subtask A. The overall object of this Task Order is to develop and demonstrate the technology to define a -3EPNdB exhaust system relative to 1992 exhaust system technology

Cisto de colédoco: relato de caso e revisão da literatura Choledochal cyst: case report and literature review

INTRODUÇÃO: Cistos de colédoco são dilatações congênitas dos ductos biliares, tanto intra quanto extra-hepáticas. É incomum com incidência estimada em 1:100.000 até 1:150.000 nascidos vivos nos países ocidentais. RELATO DO CASO: Mulher de 36 anos com história de icterícia, colúria e massa palpável em hemiabdome direito há 15 dias, negava acolia fecal, febre e emagrecimento. Ao exame físico apresentava ictérica e presença de uma massa palpável e indolor em hipocôndrio direito com cerca de 25 cm de diâmetro, sem outras alterações. Os exames laboratoriais evidenciaram aumento de enzimas canaliculares, hepatocíticas e bilirrubinas. CA 19-9, alfa-feto proteína e CEA foram normais. Exames de imagem do abdome mostraram massa de conteúdo cístico em topografia de colédoco e cabeça de pâncreas. Operada por laparotomia, foi evidenciado cisto de colédoco, classificação de Todani tipo I. A vesícula biliar foi ressecada juntamente com a porção distal do cisto e anastomose biliodigestiva em Y-de-Roux foi realizada entre a alça de jejuno e porção proximal do cisto. A evolução pós-operatória foi tumultuada com sangramento da anastomose e necessidade de reoperações para conter sangramento e complicações conseqüentes. CONCLUSÃO: Os cistos de colédoco são entidades raras e têm múltiplos aspectos em sua forma. O diagnóstico é facilmente feito pelos métodos de imagem correntes, contudo seu tratamento é difícil, por vezes de grande magnitude, e deve ser individualizado.<br>BACKGROUND: Choledochal cysts are congenital dilations of biliary ducts, being either intra or extra-hepatic. It is uncommon, having an estimated incidence of 1:100.000 to 1:150.000 born alive in western countries. CASE REPORT: Thirty six-year-old female was attended with a history of jaundice, coluria and palpable mass in the right hemiabdomen for 15 days, denying fecal acholia, having fever and weight loss. During physical examination the patient presented jaundice and a painless palpable mass in the right hypochondrium, having an approximate diameter of 25 cm, without any other alterations. Laboratory exams demonstrated an increase in canicular, hapatocytic and bilirubin enzymes. CA 19-9, alfa-fetoprotein and CEA showed normal levels. Abdominal image exams revealed a cystic content mass in the choledochal and head of the pancreas. A choledochal cyst was revealed after laparotomy, being classified as type I, with regards to Todanis' classification. The gallbaldder was ressected jointly with the distal portion of the cyst. Biliodigestive anastomosis in Y of Roux was performed between the jejunum loop and distal portion of the cyst. Postoperative evolution was tardied by bleeding from anastomosis and the patient was reoperated to contain bleeding and further complications. CONCLUSION: Choledochal cysts are rare entities, having multiple aspects regarding there shape and form. Diagnosis is easily done using image methods. However its treatment is difficult, sometimes being of great magnitude, therefore requiring individual treatment