Research Brief 08-02-HNP

Preliminary evidence suggests that improved nutrition early in human immunodeficiency virus (HIV) infection may delay progression to acquired immunodeficiency syndrome (AIDS) and delay the initiation or improve the effectiveness of antiretroviral drug therapy (ART). The scientific community has evolved in its appreciation of the value of food as an integral component of comprehensive care for individuals with HIV infection and AIDS. It is now well recognized that those who are food insecure and malnourished are more likely to fail drug treatment regimens. Body mass index (BMI) < 18 at the initiation of ART is strongly predictive of death. In addition, weight loss during the first four weeks of ART is also associated with death. A higher BMI is protective and is associated with better responses with ART. Patient response to nutrition intervention, however, may be confounded by the stage of HIV progression and other infections. That is, those who are in the earlier stages of the disease may respond better to aggressive nutrition intervention. The HIV Nutrition Project (HNP), "Increasing Animal Source Foods in Diets of HIV-infected Kenyan Women and Their Children," will evaluate the effect of protein quality and micronutrients found in meat on the health and nutritional well-being of women living with HIV in rural Kenya and the health and development of their children. By means of a randomized nutrition feeding intervention, researchers will study if the inclusion of meat added as an ingredient to a biscuit, when compared to soy or wheat, will best protect the immune system and prevent severe infection, prevent the loss of body mass and enhance the quality of life. These women are not yet receiving antiretroviral drugs and therefore not yet experiencing metabolic inefficiencies associated with AIDS.This publication was made possible through support provided by the Office of Agriculture, Bureau of Economic Growth, Agriculture and Trade, under Grant No. PCE-G-00-98-00036-00 to University of California, Davis. The opinions expressed herein are those of the authors and do not necessarily reflect the views of USAID

Research Brief 08-01-HNP

Many of the 28 million people with human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS) estimated to be living in sub-Saharan Africa also suffer from malnutrition. Reproductive-aged women, their infants and young children are among the most vulnerable to malnutrition and progression of HIV to AIDS. As seen in eastern and southern Africa, mortality is increased in the malnourished. The HIV Nutrition Project (HNP) researchers will be evaluating the effect of protein quality and micronutrients found in meat on the health and nutritional well-being of women living with HIV in rural Kenya and the health and development of their children. By means of a randomized nutrition feeding intervention, the study will determine if meat in the diets of HIV-infected women and their children (1) protects the immune system and prevents severe infection, (2) prevents the loss of lean body mass, enhancing the quality of life among these drug naive women and enabling women to carry out their activities of daily living, and (3) supports the growth and development of their vulnerable children when compared to those given supplements with the same amount of energy, but with either soya or wheat protein. The intervention food with beef protein provides significantly more vitamin B12, lysine and bio-available iron and zinc when compared to the soya and wheat supplements. Deficiencies of these nutrients may hasten HIV disease progression.This publication was made possible through support provided by the Office of Agriculture, Bureau of Economic Growth, Agriculture and Trade, under Grant No. PCE-G-00-98-00036-00 to University of California, Davis. The opinions expressed herein are those of the authors and do not necessarily reflect the views of USAID

Research Brief 08-03-HNP

In sub-Saharan Africa, an estimated 28 million people are living with the human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS). In 2001, Moi University in Eldoret, Kenya joined with Kenya’s second national referral hospital, Moi Teaching and Referral Hospital (MTRH) and Indiana University (IU) to establish the Academic Model Providing Access To Healthcare (AMPATH). AMPATH’s missions were to (1) provide high-quality patient care; (2) educate patients and health care providers; and (3) establish a laboratory for clinical research in HIV/AIDS (http://medicine.iupui.edu/kenya/hiv.aids.html). Leveraging the power of an academic medical partnership, AMPATH has quickly become one of the largest and most comprehensive HIV/AIDS control systems in sub-Saharan Africa, providing a comprehensive system of care that has been described as a model of sustainable development (Tobias, 2006). Delivery of services occurs in the public sector through hospitals and health centers run by Kenya’s Ministry of Health. AMPATH currently implements prevention activities that touch the lives of millions of persons in a wide geographic area. The research arm of AMPATH, created to facilitate and manage the international research agenda being generated by Kenyan and US faculty, includes the Global Livestock CRSP’s HIV Nutrition Project (HNP), “Increasing Animal Source Foods in Diets of HIV-infected Kenyan Women and Their Children,” which is a collaborative initiative between AMPATH and faculty from Moi University, Indiana University and the University of California, Los Angeles.This publication was made possible through support provided by the Office of Agriculture, Bureau of Economic Growth, Agriculture and Trade, under Grant No. PCE-G-00-98-00036-00 to University of California, Davis. The opinions expressed herein are those of the authors and do not necessarily reflect the views of USAID

Morbidity and nutrition status of rural drug-naïve Kenyan women living with HIV

This paper describes morbidity in a group of HIV-positive drug-naïve rural women in western Kenya. A total of 226 drug-naïve HIV-positive women were evaluated for baseline morbidity, immune function, and anthropometry before a food-based nutrition intervention. Kenyan nurses visited women in their homes and conducted semi-structured interviews regarding symptoms and physical signs experienced at the time of the visit and during the previous week and physical inspection. Blood and urine samples were examined for determination of immune function (CD4, CD8, and total lymphocyte counts), anaemia, malaria, and pregnancy status. Intradermal skin testing with tuberculin (PPD), candida, and tetanus toxoid antigens was also performed to evaluate cell-mediated immunity. Anthropometry was measured, and body mass index (BMI) was calculated. Seventy-six per cent of the women reported being sick on the day of the interview or within the previous week. Illnesses considered serious were reported by 13.7% of women. The most frequent morbidity episodes reported were upper respiratory tract infections (13.3%), suspected malaria (5.85%), skeletal pain (4.87%), and stomach pain (4.42%). The most common morbidity signs on physical inspection were respiratory symptoms, most commonly rhinorrhea and coughing. Confirmed malaria and severe diarrhea were significantly associated with a higher BMI

Mechanical similarity as a generalization of scale symmetry

In this paper we study the symmetry known as mechanical similarity (LMS) and present for any monomial potential. We analyze it in the framework of the Koopman-von Neumann formulation of classical mechanics and prove that in this framework the LMS can be given a canonical implementation. We also show that the LMS is a generalization of the scale symmetry which is present only for the inverse square potential. Finally we study the main obstructions which one encounters in implementing the LMS at the quantum mechanical level.Comment: 9 pages, Latex, a new section adde

Nonclassical time correlation functions in continuous quantum measurement

A continuous projective measurement of a quantum system often leads to a suppression of the dynamics, known as the Zeno effect. Alternatively, generalized nonprojective, so-called "weak" measurements can be carried out. Such a measurement is parameterized by its strength parameter that can interpolate continuously between the ideal strong measurement with no dynamics-the strict Zeno effect, and a weak measurement characterized by almost free dynamics but blurry observations. Here we analyze the stochastic properties of this uncertainty component in the resulting observation trajectory. The observation uncertainty results from intrinsic quantum uncertainty, the effect of measurement on the system (backaction) and detector noise. It is convenient to separate the latter, system-independent contribution from the system-dependent uncertainty, and this paper shows how to accomplish this separation. The system-dependent uncertainty is found in terms of a quasi-probability, which, despite its weaker properties, is shown to satisfy a weak positivity condition. We discuss the basic properties of this quasi-probability with special emphasis on its time correlation functions as well as their relationship to the full correlation functions along the observation trajectory, and illustrate our general results with simple examples.We demonstrate a violation of classical macrorealism using the fourth-order time correlation functions with respect to the quasi-probability in the twolevel system.Comment: 20 pages, 1 figure, published version (open access

Differential Geometry of Quantum States, Observables and Evolution

The geometrical description of Quantum Mechanics is reviewed and proposed as an alternative picture to the standard ones. The basic notions of observables, states, evolution and composition of systems are analised from this perspective, the relevant geometrical structures and their associated algebraic properties are highlighted, and the Qubit example is thoroughly discussed.Comment: 20 pages, comments are welcome

On domain walls in a Ginzburg-Landau non-linear S^2-sigma model

The domain wall solutions of a Ginzburg-Landau non-linear $S^2$-sigma hybrid model are unveiled. There are three types of basic topological walls and two types of degenerate families of composite - one topological, the other non-topological- walls. The domain wall solutions are identified as the finite action trajectories (in infinite time) of a related mechanical system that is Hamilton-Jacobi separable in sphero-conical coordinates. The physical and mathematical features of these domain walls are thoroughly discussed.Comment: 26 pages, 18 figure

The role of Kelvin-Helmholtz instability in the internal structure of relativistic outflows. The case of the jet in 3C 273

Relativistic outflows represent one of the best-suited tools to probe the physics of AGN. Numerical modelling of internal structure of the relativistic outflows on parsec scales provides important clues about the conditions and dynamics of the material in the immediate vicinity of the central black holes in AGN. We investigate possible causes of the structural patterns and regularities observed in the parsec-scale jet of the well-known quasar 3C 273. We present here the results from a 3D relativistic hydrodynamics numerical simulation based on the parameters given for the jet by Lobanov & Zensus (2001), and one in which the effects of jet precession and the injection of discrete components have been taken into account. We compare the model with the structures observed in 3C 273 using very long baseline interferometry and constrain the basic properties of the flow. We find growing perturbation modes in the simulation with similar wavelengths to those observed, but with a different set of wave speeds and mode identification. If the observed longest helical structure is produced by the precession of the flow, longer precession periods should be expected. Our results show that some of the observed structures could be explained by growing Kelvin-Helmholtz instabilities in a slow moving region of the jet. However, we point towards possible errors in the mode identification that show the need of more complete linear analysis in order to interpret the observations. We conclude that, with the given viewing angle, superluminal components and jet precession cannot explain the observed structures.Comment: Accepted for publication in Astronomy & Astrophysics. 14 pages. Higher resolution plots available on request to [email protected] and at http://www.mpifr-bonn.mpg.de/staff/mperuch

Towards a definition of quantum integrability

We briefly review the most relevant aspects of complete integrability for classical systems and identify those aspects which should be present in a definition of quantum integrability. We show that a naive extension of classical concepts to the quantum framework would not work because all infinite dimensional Hilbert spaces are unitarily isomorphic and, as a consequence, it would not be easy to define degrees of freedom. We argue that a geometrical formulation of quantum mechanics might provide a way out.Comment: 37 pages, AmsLatex, 1 figur