391 research outputs found
Zero Shot Learning with the Isoperimetric Loss
We introduce the isoperimetric loss as a regularization criterion for
learning the map from a visual representation to a semantic embedding, to be
used to transfer knowledge to unknown classes in a zero-shot learning setting.
We use a pre-trained deep neural network model as a visual representation of
image data, a Word2Vec embedding of class labels, and linear maps between the
visual and semantic embedding spaces. However, the spaces themselves are not
linear, and we postulate the sample embedding to be populated by noisy samples
near otherwise smooth manifolds. We exploit the graph structure defined by the
sample points to regularize the estimates of the manifolds by inferring the
graph connectivity using a generalization of the isoperimetric inequalities
from Riemannian geometry to graphs. Surprisingly, this regularization alone,
paired with the simplest baseline model, outperforms the state-of-the-art among
fully automated methods in zero-shot learning benchmarks such as AwA and CUB.
This improvement is achieved solely by learning the structure of the underlying
spaces by imposing regularity.Comment: Accepted to AAAI-2
HIV prevention in Mexican schools: prospective randomised evaluation of intervention.
OBJECTIVE: To assess effects on condom use and other sexual behaviour of an HIV prevention programme at school that promotes the use of condoms with and without emergency contraception. DESIGN: Cluster randomised controlled trial. SETTING: 40 public high schools in the state of Morelos, Mexico. PARTICIPANTS: 10 954 first year high school students. INTERVENTION: Schools were randomised to one of three arms: an HIV prevention course that promoted condom use, the same course with emergency contraception as back-up, or the existing sex education course. Self administered anonymous questionnaires were completed at baseline, four months, and 16 months. Students at intervention schools received a 30 hour course (over 15 weeks) on HIV prevention and life skills, designed in accordance with guidelines of the joint United Nations programme on HIV/AIDS. Two extra hours of education on emergency contraception were given to students in the condom promotion with contraception arm. MAIN OUTCOME MEASURES: Primary outcome measure was reported condom use. Other outcomes were reported sexual activity; knowledge and attitudes about HIV and emergency contraception; and attitudes and confidence about condom use. RESULTS: Intervention did not affect reported condom use. Knowledge of HIV improved in both intervention arms and knowledge of emergency contraception improved in the condom promotion with contraception arm. Reported sexual behaviour was similar in the intervention arms and the control group. CONCLUSION: A rigorously designed, implemented, and evaluated HIV education course based in public high schools did not reduce risk behaviour, so such courses need to be redesigned and evaluated. Addition of emergency contraception did not decrease reported condom use or increase risky sexual behaviour but did increase reported use of emergency contraception
Cost of AIDS care in Mexico: what are its main individual predictors?
BACKGROUND: The Mexican government is offering universal access to antiretroviral (ARV) drugs. The cost of doing so, despite aggressive price negotiation with the pharmaceutical industry, remains high. Even with a low prevalence, about 150,000 Mexicans are estimated to be living with HIV and will require ARV treatment. Estimating the resources needed to fund this gap should consider how patient and provider characteristics affect health care costs. METHODS: Using a sample of patients from 11 facilities in three Mexican cities representing a large proportion of AIDS patients in the country, we developed a fixed-effect model, which by controlling the facilities and individual heterogeneity estimates predicted costs using patient demographic and socioeconomic characteristics as well as physician training. RESULTS: The estimated model explains about 45% of the variation in costs. Additional education is significantly and positively associated with cost. Increasing age is also associated with higher costs. CONCLUSIONS: Socioeconomic status and demographic characteristics explain an important proportion of variation in care costs for AIDS, despite AIDS being such a heterogeneous disease. Such characteristics will need to be taken into account when resource needs are estimated. A priority-setting process considering the principles of equity in the fair distribution of resources is needed to help reduce the social burden of HIV/AIDS in Mexico
Estimating resource needs for HIV/AIDS health care services in low-income and middle-income countries.
As funding mechanisms like the Global Fund for HIV/AIDS, Tuberculosis and Malaria increasingly make funding decisions on the basis of burden of disease estimates and financial need calculations, the importance of reliable and comparable estimating methods is growing. This paper presents a model for estimating HIV/AIDS health care resource needs in low- and middle-income countries. The model presented was the basis for the United Nations' call for US dollars 9.2 billion to address HIV/AIDS in developing countries by 2005 with US dollars 4.4 billion to address HIV/AIDS health care and the rest to deal with HIV/AIDS prevention. The model has since been updated and extended to produce estimates for 2007. This paper details the methods and assumptions used to estimate HIV/AIDS health care financial needs and it discusses the limitations and data needs for this model
Addressing inequity in health and health care in Mexico.
Despite the fact that life expectancy at birth in Mexico has improved from forty-two years in 1940 to seventy-three in 2000, major inequalities persist in health and access to health care. The Mexican health care system has evolved into a series of disjointed subsystems that are incapable of delivering universal health insurance. Without greatly restructuring the way health care is financed, performance with respect to equity will remain poor. This paper presents the inequities of the system and describes how the current system contributes to the status quo rather than redressing the situation. After tracing the origins of the present system, we discuss policy initiatives for moving toward universal health insurance
Access to condoms for female sex workers in Andhra Pradesh.
BACKGROUND: Condoms are an essential part of comprehensive HIV prevention and care programmes. We report the accessibility of male condoms for female sex workers (FSWs) and the associated characteristics that may play a major role in determining access to condoms for FSWs. METHODS: Confidential interviews of 6509 street- and home-based FSWs in 13 districts of the Indian state of Andhra Pradesh provided data on the number of paying clients and various aspects of access to free condoms and purchase of condoms. Access to condoms was defined as having ever obtained condoms either through free distribution or through purchase. Multivariate analyses were done separately for street- and home-based FSWs to describe correlates of their access to condoms. The requirement of condoms was assessed based on the number of paying clients during the past 15 days. RESULTS: Data on condom access were available for 6465 (99.3%) FSWs. A total of 2850 (44.1%; 95% CI: 36.2%-52.0%) reported accessing free condoms ever and 2336 (36.1%; 95% CI: 30.6%-41.6%) had purchased condoms ever (not mutually exclusive). The primary sources for condoms were non-governmental organization facilities (73.8%) and pharmacies (79.7%) for free and purchased condoms, respectively. A total of 3510 (54.3%; 95% CI: 48.5%-60.1%) FSWs reported no access to free or purchased condoms during the past 15 days, and this no access was significantly higher for those > 30 years of age, with no schooling, street-based FSWs, and with no participation in a FSW support group (p < 0.001 for each in univariate analysis). Participation in a FSW support group was the main predictor of access to free condoms for both types of FSWs during the past 15 days with multivariate analysis. Condom requirements during the past 15 days were met for 67.5% of FSWs who had accessed only free condoms and for 33.8% of those who had accessed only purchased condoms. CONCLUSIONS: One-fourth of FSWs had never accessed condoms, and a little over half of those who had ever accessed reported no access during the past 15 days. Condom requirements were not met for three-fifths of the FSWs. HIV prevention programmes need to Increase access to free condoms for FSWs in Andhra Pradesh as access to condoms is a necessary prerequisite for condom use
Resource requirements to fight HIV/AIDS in Latin America and the Caribbean.
OBJECTIVES: Economists and epidemiologists from 10 countries in Latin America and the Caribbean (LAC) reviewed the methods used to develop estimates for resource requirements to address HIV/AIDS prevention and care in low- and middle-income countries. METHODS: They applied their country-specific knowledge to re-estimate the costs, coverage, and capacity of their health and education systems to expand HIV/AIDS interventions by 2005. A discrepancy of 173 million US dollars exists between the model estimates and those of country specialists. RESULTS: The most important difference between the model estimates and those of country specialists was in the estimated future price of highly active antiretroviral therapy. To a large extent, the estimates of the model reflect the efficiency gains that could result from purchasing arrangements that lead LAC countries to lower prices for antiretroviral drugs. CONCLUSION: This preliminary exercise with 10 LAC countries confirmed the validity of the use of these estimates as tools at the international level, given current data limitations, both to guide the allocation of resources across diseases and countries, and for advocacy and resource mobilization. In addition, with the country revisions, these estimates have also been shown to be key tools for country-level strategic planning
The economics of psychedelic-assisted therapies: A research agenda
After a long hiatus, psychiatry is undergoing a resurgence of interest in psychedelic drugs as therapy for a wide range of mental health disorders Accumulating clinical evidence suggests substantial potential for psychedelics used in a therapeutic context, as treatment for, among other disorders, depression, post-traumatic stress disorder (PTSD), and addictions to tobacco, opioids and alcohol. As soon as 2024, powerful new therapeutic modalities could become available for individuals with mental health problems refractory to traditional therapies. Yet research has lagged on economic considerations, such as costs and cost-effectiveness, the economic effects of widespread implementation, pricing, and economic appraisal's methodological considerations relevant to psychedelic therapies. These issues are critical if psychedelic therapies are to become widely accessible. We describe six types of economic analyses and their rationale for decisions and planning including the needs of health care payers. We also outline desirable features of this research, including scientific rigor, long horizons, equity, and a global view
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