A New Quantization Map

In this paper we find a simple rule to reproduce the algebra of quantum observables using only the commutators and operators which appear in the Koopman-von Neumann (KvN) formulation of classical mechanics. The usual Hilbert space of quantum mechanics becomes embedded in the KvN Hilbert space: in particular it turns out to be the subspace on which the quantum positions Q and momenta P act irreducibly.Comment: 12 pages, 1 figure, Late

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

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

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

Koopman-von Neumann Formulation of Classical Yang-Mills Theories: I

In this paper we present the Koopman-von Neumann (KvN) formulation of classical non-Abelian gauge field theories. In particular we shall explore the functional (or classical path integral) counterpart of the KvN method. In the quantum path integral quantization of Yang-Mills theories concepts like gauge-fixing and Faddeev-Popov determinant appear in a quite natural way. We will prove that these same objects are needed also in this classical path integral formulation for Yang-Mills theories. We shall also explore the classical path integral counterpart of the BFV formalism and build all the associated universal and gauge charges. These last are quite different from the analog quantum ones and we shall show the relation between the two. This paper lays the foundation of this formalism which, due to the many auxiliary fields present, is rather heavy. Applications to specific topics outlined in the paper will appear in later publications.Comment: 46 pages, Late

Coadjoint Orbits, Spin and Dequantization

In this Letter we propose two path integral approaches to describe the classical mechanics of spinning particles. We show how these formulations can be derived from the associated quantum ones via a sort of geometrical dequantization procedure proposed in a previous paper.Comment: 13 pages, Latex, title change

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

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

Geometric Dequantization

Dequantization is a set of rules which turn quantum mechanics (QM) into classical mechanics (CM). It is not the WKB limit of QM. In this paper we show that, by extending time to a 3-dimensional "supertime", we can dequantize the system in the sense of turning the Feynman path integral version of QM into the functional counterpart of the Koopman-von Neumann operatorial approach to CM. Somehow this procedure is the inverse of geometric quantization and we present it in three different polarizations: the Schroedinger, the momentum and the coherent states ones.Comment: 50+1 pages, Late