Guillermo Pérez

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PURPOSE To propose a new objective scatter index (OSI) based in the analysis of double-pass images of a point source to rank and classify cataract patients. This classification scheme is compared with a current subjective system. METHODS We selected a population including a group of normal young eyes as control and patients diagnosed with cataract (grades(More)
The execution environment of Android system is based on a virtual machine called Dalvik virtual machine (DVM) in which the execution of an application program is in interpret-mode. To reduce the interpretation overhead of DVM, Google has included a trace-based just-in-time compiler (JITC) in the latest version of Android. Due to limited resources and the(More)
The Dalvik virtual machine is the main application platform running on Google's Android operating system for mobile devices and tablets. It is a Java Virtual Machine running a basic trace-based JIT compiler, unlike web browser JavaScript engines that usually run a combination of both method and trace-based JIT types. We developed a method-based JIT compiler(More)
Health initiatives are becoming a growing solution for healthcare provision in developing countries. With the purpose of helping people from underserved areas to access physicians, the University of California Irvine has designed the mobile application VirTelMed. The objective of the study was to implement a usability study of VirTelMed in South Africa,(More)
Reaching universal HIV-status awareness is crucial to ensure all HIV-infected patients access antiretroviral treatment (ART) and achieve virological suppression. Opportunities for HIV testing could be enhanced by offering self-testing in populations that fear stigma and discrimination when accessing conventional HIV Counselling and Testing (HCT) in health(More)
INTRODUCTION Malawi has one of the highest HIV prevalences in Sub-Saharan Africa. The rate of eligible HIV-infected people being initiated on antiretroviral therapy (ART) and retained in HIV-care is currently far from adequate. Consequently, many people continue present with advanced immunosuppression at public health facilities, often with undiagnosed(More)
Text messages (SMS) are being increasingly integrated into HIV programs across Southern Africa to improve patient adherence, linkage to care and provide psycho-social support. Careful attention needs to be paid to the design of SMS-based interventions for clients of HIV-care services to ensure that any potential harm, such as unwanted disclosure of HIV(More)
A polychromatic double-pass setup was developed to study the effects of wavelength and polarization on retinal image quality. The results show that the central part of the images was similar for all wavelengths (543, 633 and 780 nm) and polarization states. However, the image tails increased significantly when using infrared light for all the polarization(More)
Reranking modules of conventional parsers make use of either probabilistic weights linked to the production rules or just hand crafted rules to choose the best possible parse. Other proposals make use of the topology of the parse trees and lexical features to reorder the parsing results. In this work, a new reranking approach is presented. There are two(More)