Parity violation in quasifree electron scattering off the deuteron

For deuteron electroweak disintegration, parity violating effects are investigated which arise from the interference of $\gamma$ and $Z$ exchange as well as from the hadronic sector via a small parity violating component in the deuteron. The general formalism for the differential cross section and polarization observables of electromagnetic deuteron disintegration is extended to incorporate parity violating contributions. Formal expressions for the additional structure functions are derived. Results are presented for these parity violating structure functions for quasifree kinematics neglecting final state interaction and two-body effects. Both types of parity violating contributions to the asymmetry of the inclusive reaction with respect to longitudinally polarized electrons are evaluated. The one from parity violating deuteron components is negligible over the whole range of momentum transfers considered.Comment: 21 pages revtex including 12 postscript figures, revised version, accepted for publication in Nucl. Phys.

Electroweak Processes in Few-Nucleon Systems

After a brief introduction into the basic ingredients of electroweak theory as a spontaneously broken local, non-Abelian gauge symmetry, the general properties of the electromagnetic current and two-photon operators are discussed. The specific forms of vector and axial one-nucleon currents are given, together with lowest order $\pi$ meson exchange and isobar currents as well as meson production currents. A brief overview is given on the most important one- and two-boson processes. Electron scattering in the one-boson- approximation is then considered in greater detail. Formal expressions of the cross section for inclusive and exclusive processes are given, including parity violating contributions from $\gamma$-$Z$ interference as well as from parity violating components in the hadronic wave function. Specific electromagnetic reactions on the deuteron are then discussed with respect to the influence of meson exchange currents, isobar configurations in the deuteron groundstate, relativistic contributions and the role of $\pi$-meson retardation. Furthermore, recent results on coherent and incoherent $\pi$- and $\eta$-photoproduction are presented as well as a discussion of the Gerasimov-Drell-Hearn sum rule and the effect of a parity violating deuteron component on inclusive electron scattering off the deuteron for quasifree kinematics. The review closes with a summary and a brief outlook.Comment: 56 pages latex including 42 postscript figures, Lectures held at the Int. Workshop on Few-Body Problems in Nuclear Physics and Related Fields, ECT$^\ast$, Trento, Italy, September 8-27, 199

Acidúria 3-Hidroxi-3-Metilglutárica : perfil clínico e bioquímico de casos diagnosticados no Brasil nos últimos 24 anos

Introdução: A acidemia 3-hidroxi-3-metilglutárica é uma doença genética autossômica recessiva e um erro inato do metabolismo em que se tem a deficiência na enzima 3-hidroxi-3-metilglutaril CoA liase, que é uma enzima fundamental no metabolismo da leucina e na produção de corpos cetônicos. Objetivo: Coletar e analisar dados de 1994 até os dias atuais de todos os pacientes diagnosticados no Hospital de Clínicas de Porto Alegre com a doença. Métodos: Análise de ácidos orgânicos na urina foi realizada por cromatografia gasosa e cromatografia gasosa acoplada a espectrômetro de massas e de acilcarnitinas no sangue por cromatografia liquida acoplada a espectrômetro de massas. A análise molecular foi feita pelo método de Southern blot seguida de PCR. Estes pacientes são de diversos estados brasileiros e seu diagnóstico é tardio. Resultados: Os principais metabólitos encontrados na urina por cromatografia gasosa foram os ácidos orgânicos 3-hidroxi-3-metilglutárico, 3-metilglutacônico, 3-metilglutárico e 3-hidroxi-isovalérico. Na análise de acilcarnitinas em sangue impregnado em papel filtro por cromatografia liquida acoplada a espectrômetro de massas foi detectado o aumento da acilcarnitina 3-hidroxi-isovalerilcarnitina e da razão 3-hidroxi-isovalerilcarnitina/ carnitina principalmente. Os resultados da análise molecular mostraram a mutação E37X como a principal. Os sintomas clínicos foram em grande maioria neurológicos como convulsões ou de recusa alimentar como vômitos. A análise laboratorial revelou hipoglicemia e acidose metabólica na maioria dos casos. Como o diagnóstico foi tardio, muitos destes pacientes já faziam algum tratamento medicamentoso e dietético. Conclusão: Cabe salientar a importância do diagnóstico desta acidemia orgânica, ainda que tardio, prevenindo o óbito e possibilitando instituição terapêutica.Introduction: 3-hydroxy-3-methylglutaric acidemia is an autosomal recessive genetic disorder and an inborn error of metabolism in which there is a deficiency in the enzyme 3-hydroxy-3-methylglutaryl CoA lyase, which is a key enzyme in metabolism of leucine and in the production of ketone bodies. Objective: To collect and to analyze data from 1994 to the present day of all patients diagnosed at the Hospital de Clínicas de Porto Alegre with the disease. Methods: Analysis performed by gas chromatography and gas chromatography coupled to mass spectrometer of organic acids in urine and acylcarnitines in blood by liquid chromatography coupled to mass spectrometer. Molecular analysis was done by the Southern blot method followed by PCR. These patients are from several Brazilian states and their diagnosis is late. Results: The major metabolites found in urine by gas chromatography were organic acids 3-hydroxy-3-methylglutaric, 3-methylglutaconic, 3-methylglutaric and 3-hydroxyisovaleric. In the analysis of acylcarnitines in blood impregnated on filter paper by liquid chromatography coupled to mass spectrometer, the increase of the acylcarnitine 3-hydroxy-isovalerylcarnitine and the 3-hydroxy-isovalerylcarnitine / carnitine ratio were mainly 7 detected. The results of the molecular analysis showed the E37X mutation as the main one. Clinical symptoms were largely neurological such as seizures or refusal to feed like vomiting. Laboratory analysis revealed hypoglycemia and metabolic acidosis in most cases. As the diagnosis was late, many of these patients already had some drug and dietary treatment. Conclusion: It is necessary to emphatize the importance of the diagnosis this organic acidemia, even if late, preventing death and making possible a therapeutic institution

What is Leadership?

Welcome to the first in a series of research reports from Leadership South West, which gives an introduction to some of the key issues in the field of leadership, including what is it, how can it be measured and what impact does it have upon performance? This report does not claim to be the definitive guide to all things leadership, but rather to present some of the most significant concepts and debates to have emerged in recent years. Leadership is currently one of the most talked about issues in business and organisation. It is hard to turn on the television, open a newspaper or attend a conference without coming across numerous references to leaders, leadership and leading. A search of the Amazon.com website in Spring 2003 revealed 11,686 results for the word ‘leadership’ alone and similar searches of the Ebsco business and management publications database reveal an exponential increase in the number of published articles on leadership, from 136 in 1970-71, to 258 in 1980-81, 1,105 in 1990-91, and a staggering 10,062 in 2001-02 (an average of 419 articles per month) (Storey, 2004). The recent focus on leadership is an international phenomenon, as is increased investment in leadership and management development. In the US, for example, Fulmer (1997) estimated an annual corporate expenditure of $45 billion in 1997 (up from$10 billion one decade before) and Sorenson (2002) identified 900 college or university leadership programmes (double that of four years earlier), over 100 specialist degrees and a wide range of related activities. Similar trends are occurring in the UK and Europe. Leadership is regarded as the key ‘enabler’ in the European Foundation for Quality Management (EFQM) Business Excellence Model (EFQM, 2000) and has become a central focus for numerous other public, private and voluntary sector development initiatives. Recent years have seen centres of excellence in leadership established for nearly all parts of the public sector, including health, defence, education and police. Leadership, it seems, is increasingly becoming the panacea of the 21st Century. Amidst this flurry of activity, however, a number of concerns arise. There is no widely accepted definition of leadership, no common consensus on how best to develop leadership and leaders, and remarkably little evidence of the impact of leadership or leadership development on performance and productivity. Indeed, most initiatives appear to actively avoid addressing these issues and simply opt for the feel good factor of doing something about it… whatever ‘it’ may be! Whilst action is frequently preferable to inaction, without at least some understanding of the underlying principles and assumptions about leadership and leadership development, it is likely that action may be misguided – at least reducing its possible effectiveness and at worst damaging what was there in the first place. The intention of this report, therefore, is to challenge some of the more popularist and stereotypical notions of leadership and to offer some insights into alternative ways of conceiving and addressing the issue.South West Regional Development Agenc

Deuterium spectroscopy for enhanced bounds on physics beyond the Standard Model

We consider the impact of combining precision spectroscopic measurements made in atomic hydrogen with similar measurements made in atomic deuterium on the search for physics beyond the Standard Model. Specifically we consider the wide class of models that can be described by an effective Yukawa-type interaction between the nucleus and the electron. We find that it is possible to set bounds on new light-mass bosons that are orders of magnitude more sensitive than those set using a single isotope only, provided the interaction couples differently to the deuteron and proton. Further enhancements of these bounds by an order of magnitude or more would be made possible by extending the current measurements of the isotope shift of the 1s$_{1/2}$-2s$_{1/2}$ transition frequency to that of a transition between the 2s$_{1/2}$ state and a Rydberg s-state.Comment: 16 pages, 9 figure

Perpindahan Kalor

Sistematika buku ini dengan judul “Perpindahan Kalor” terdiri atas 14 bab yang dijelaskan secara rinci dalam pembahasan mengenai konsep dan Aplikasi diantaranya: Konsep dan analisis Energi Kalor, Sumber Kalor, Konduksi Dimensi, Rangkaian Hambatan, konveksi ilmiah konveksi paksa, aliran Fluida dalam Pipa, Sistem Termal pada Heat Exchanger, Penukaran kalor jenis Shell and tube, Dasar Radiasi, Energi Surya dan Aplikasinya