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Search Results: 1 - 10 of 4366 matches for " Lynn Ramirez-Avila "
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Routine HIV Testing in Adolescents and Young Adults Presenting to an Outpatient Clinic in Durban, South Africa
Lynn Ramirez-Avila, Kristy Nixon, Farzad Noubary, Janet Giddy, Elena Losina, Rochelle P. Walensky, Ingrid V. Bassett
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0045507
Abstract: Objectives Although youth (12–24 years) in Sub-Saharan Africa have a high HIV risk, many have poor access to HIV testing services and are unaware of their status. Our objective was to evaluate the proportion of adolescents (12–17 years) and young adults (18–24 years) who underwent HIV testing and the prevalence among those tested in an urban adult outpatient clinic with a routine HIV testing program in Durban, South Africa. Design We conducted a retrospective cross-sectional analysis of adolescent and young adult outpatient records between February 2008 and December 2009. Methods We determined the number of unique outpatient visitors, HIV tests, and positive rapid tests among those tested. Results During the study period, 956 adolescents registered in the outpatient clinic, of which 527 (55%) were female. Among adolescents, 260/527 (49%, 95% CI 45–54%) females underwent HIV testing compared to 129/429 (30%, 95% CI 26–35%) males (p<0.01). The HIV prevalence among the 389 (41%, 95% CI 38–44%) adolescents who underwent testing was 16% (95% CI 13–20%) and did not vary by gender (p = 0.99). During this period, there were 2,351 young adult registrations, and of these 1,492 (63%) were female. The proportion consenting for HIV testing was similar among females 980/1,492 (66%, 95% CI 63–68%) and males 543/859 (63%, 95% CI 60–66%, p = 0.25). Among the 1,523 (65%, 95% CI 63–67%) young adults who underwent testing, the HIV prevalence was 22% (95% CI 19–24%) in females versus 14% in males (95% CI 11–17%, p<0.01). Conclusions Although the HIV prevalence is high among youth participating in an adult outpatient clinic routine HIV program, the uptake of testing is low, especially among 12–17 year old males. There is an urgent need to offer targeted, age-appropriate routine HIV testing to youth presenting to outpatient clinics in epidemic settings.
Early infant HIV-1 diagnosis programs in resource-limited settings: opportunities for improved outcomes and more cost-effective interventions
Andrea L Ciaranello, Ji-Eun Park, Lynn Ramirez-Avila, Kenneth A Freedberg, Rochelle P Walensky, Valeriane Leroy
BMC Medicine , 2011, DOI: 10.1186/1741-7015-9-59
Abstract: Mother-to-child transmission (MTCT) of HIV-1 results in approximately 370,000 infant infections worldwide each year [1]. HIV-1 early infant diagnosis (EID) programs seek to inform the caregivers of HIV-exposed infants of infant HIV infection status, and to link HIV-infected infants to care and treatment. EID of HIV confers substantial benefits to infants and families, both for HIV-infected and uninfected infants, as well as to programs providing prevention of mother-to-child transmission (PMTCT) services. The World Health Organization (WHO) estimates that only 6% to 15% of HIV-exposed infants under 1 year of age accessed EID programs in 2008-2009 [2], highlighting that the implementation of effective EID programs has been challenging in resource-limited settings and demands careful attention.A frequently cited barrier to expansion of EID programs is the availability and cost of the required laboratory assays, which are usually PCR based and therefore more expensive than the antibody-based testing used for older children and adults [3,4]. However, cost is not the only barrier to implementing EID programs. Opportunities to optimize infant outcomes may be lost at each step in a 'cascade' of EID and pediatric HIV care (Figure 1), conceptually similar to the recently described 'cascade' of care required for effective PMTCT services [5]. The EID cascade includes the offer and acceptance of EID testing among HIV-exposed infants, including those for whom HIV exposure was unknown; accurate specimen collection, transport, and laboratory processing; relay of results to both healthcare providers and infants' families/caregivers; and linkage to care, cotrimoxazole prophylaxis, and antiretroviral therapy (ART) for infants identified as HIV infected. In this review, we outline the ways in which interventions targeting each step in this EID cascade may impact clinical outcomes, costs, and cost effectiveness of EID programs.In adults and older children, chronic HIV-1 infection can b
Validation and Calibration of a Computer Simulation Model of Pediatric HIV Infection
Andrea L. Ciaranello, Bethany L. Morris, Rochelle P. Walensky, Milton C. Weinstein, Samuel Ayaya, Kathleen Doherty, Valeriane Leroy, Taige Hou, Sophie Desmonde, Zhigang Lu, Farzad Noubary, Kunjal Patel, Lynn Ramirez-Avila, Elena Losina, George R. Seage III, Kenneth A. Freedberg
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0083389
Abstract: Background Computer simulation models can project long-term patient outcomes and inform health policy. We internally validated and then calibrated a model of HIV disease in children before initiation of antiretroviral therapy to provide a framework against which to compare the impact of pediatric HIV treatment strategies. Methods We developed a patient-level (Monte Carlo) model of HIV progression among untreated children <5 years of age, using the Cost-Effectiveness of Preventing AIDS Complications model framework: the CEPAC-Pediatric model. We populated the model with data on opportunistic infection and mortality risks from the International Epidemiologic Database to Evaluate AIDS (IeDEA), with mean CD4% at birth (42%) and mean CD4% decline (1.4%/month) from the Women and Infants’ Transmission Study (WITS). We internally validated the model by varying WITS-derived CD4% data, comparing the corresponding model-generated survival curves to empirical survival curves from IeDEA, and identifying best-fitting parameter sets as those with a root-mean square error (RMSE) <0.01. We then calibrated the model to other African settings by systematically varying immunologic and HIV mortality-related input parameters. Model-generated survival curves for children aged 0-60 months were compared, again using RMSE, to UNAIDS data from >1,300 untreated, HIV-infected African children. Results In internal validation analyses, model-generated survival curves fit IeDEA data well; modeled and observed survival at 16 months of age were 91.2% and 91.1%, respectively. RMSE varied widely with variations in CD4% parameters; the best fitting parameter set (RMSE = 0.00423) resulted when CD4% was 45% at birth and declined by 6%/month (ages 0-3 months) and 0.3%/month (ages >3 months). In calibration analyses, increases in IeDEA-derived mortality risks were necessary to fit UNAIDS survival data. Conclusions The CEPAC-Pediatric model performed well in internal validation analyses. Increases in modeled mortality risks required to match UNAIDS data highlight the importance of pre-enrollment mortality in many pediatric cohort studies.
The Phase Information Associated to Synchronized Electronic Fireflies
Jean-Luc Guisset,Jean-Louis Deneubourg,Gonzalo Marcelo Ramirez-Avila
Physics , 2002,
Abstract: An electronic implementation referring to fireflies ensembles flashing in synchrony in a self-organization mode, shows the details of the phase-locking mechanism and how the phases between the electronic oscillators are related to their common period. Quantitative measurements of the timing signals link the limits of a steadily established synchronization to the physics of the electronic circuit. Preliminary observations suggest the existence of bifurcation-like phenomena.
Asimetrías de CP en Mesones B y Física Nueva
David Delepine,Carlos A. Ramirez,Benjamín Raziel Jaramillo Avila
Acta Universitaria , 2012,
Abstract: La colaboración BELLE reporto violación de CP (C, conjugación de carga y P, paridad) en decaimientos directos de mesones B en mesones K y piones. Pero las asimetrías de CP medidas en el decaimiento del y en el decaimiento delresultan muy diferentes una del otro cuando se esperaría a dentro del modelo que unifica las interacciones electromagnéticas, débiles y fuertes que las asimetrías de CP deberían tener el mismo signo y un valor muy cercana. En este trabajo, se estudia cómo se tiene que modificar el modelo estándar de las interacciones fundamentales para explicar las observaciones de BELLE. Nuestro análisis es modelo-independiente. Y demostramos que no se puede reproducir los resultados de BELLE solamente modificando la fase de los coeficientes de Wilson que describen esos procesos.
Structural and Thermal Properties of Tb, Ce Doped Y2.97Gd0.03Al2Ga3O12 Single Crystals  [PDF]
Mohammad Faheem, Kelvin Lynn
American Journal of Analytical Chemistry (AJAC) , 2014, DOI: 10.4236/ajac.2014.511078
Abstract: The structural and thermal properties of yttrium-aluminum-gadolinium-gallium (Y2.97Gd0.03Al2Ga3O12) single crystals doped with terbium (0.1%), cerium (0.01%) and co-doped with both terbium and cerium ((0.1, 0.01)%) were investigated. All samples were heated (calcined) at 1400°C for 15 hours before crystallization. X-ray powder diffraction (XRD) patterns of all calcined samples showed the presence of yttrium gallium aluminate (Y3Al2Ga3O12) and gadolinium gallium oxide (Gd3GaO6) while the grown crystals were single phase of Y3Al2Ga3O12. The lattice parameter of the crystals decreased with Ce doping. The thermal conductivity of each sample was determined from 25°C to 300°C and found to decrease exponentially with increasing temperature. All doped crystals have different thermal conductivity, which is attributed to the crucial influence of crystals structures. 0.01% Ce:YAGG was found to be a strong candidate for scintillators and other lasing materials because of its good thermal behavior (10.71 W/m·K).
Complexity of Interaction in a Second Language Conversation Group: An Exploratory Study  [PDF]
Melanie Lynn D’Amico
Open Journal of Modern Linguistics (OJML) , 2015, DOI: 10.4236/ojml.2015.54031
Abstract: The aim of this research was to explore the nature of conversation in a weekly second language Italian conversation group. Analysis of conversations focused on the range of topics and verbal structures used by learners. Additional analysis was completed to determine if learners engaged in negotiation of meaning or form during conversations. Results revealed that learners used a range of topics and verbal structures from Beginner level to Advanced level indicating that learners challenged themselves to produce high quality, natural conversation. Learners also showed some use of negotiation during conversations to repair communication breakdowns, principally to address meaning; however, the amount of negotiation was low when compared to task-based interaction designed to elicit negotiation.
Detection of Behavior Patterns in Single Women in Mexico  [PDF]
Edgardo Ruiz, Argelia Avila
Psychology (PSYCH) , 2013, DOI: 10.4236/psych.2013.411129

The proposal of this work is to detect the existence of patterns of interactive sequential discursive behavior in three single Mexican adult women from retrospective analysis of the interview between them and the interviewer. The applied methodology was observational. It was developed iteratively and thoroughly, a category system as an instrument of observation, and then it was undergone a recategorization process. The number of sessions observed was three, of three hours a duration. Intersessional sequential analysis was used through the SDIS-GSEQ software. Thus we find that the first significant categories in order of occurrence are: Being for her self, Paradox and Independence. The following in significant probability of occurrence position are: Dependency, self-satisfaction, Complementary, Comprehension andNormal. Finally, the categories that are inhibitory occurrence probabilistically negative are: Responsible, Myself, Self-understanding. Finding out these women are learning to live for themselves within a process of emancipation from their families and social structures.

Abnormal Activation of BMP Signaling Causes Myopathy in Fbn2 Null Mice
Gerhard Sengle?,Valerie Carlberg?,Sara F. Tufa?,Noe L. Charbonneau?,Silvia Smaldone?,Eric J. Carlson?,Francesco Ramirez,Douglas R. Keene?,Lynn Y. Sakai
PLOS Genetics , 2015, DOI: 10.1371/journal.pgen.1005340
Abstract: Fibrillins are large extracellular macromolecules that polymerize to form the backbone structure of connective tissue microfibrils. Mutations in the gene for fibrillin-1 cause the Marfan syndrome, while mutations in the gene for fibrillin-2 cause Congenital Contractural Arachnodactyly. Both are autosomal dominant disorders, and both disorders affect musculoskeletal tissues. Here we show that Fbn2 null mice (on a 129/Sv background) are born with reduced muscle mass, abnormal muscle histology, and signs of activated BMP signaling in skeletal muscle. A delay in Myosin Heavy Chain 8, a perinatal myosin, was found in Fbn2 null forelimb muscle tissue, consistent with the notion that muscle defects underlie forelimb contractures in these mice. In addition, white fat accumulated in the forelimbs during the early postnatal period. Adult Fbn2 null mice are already known to demonstrate persistent muscle weakness. Here we measured elevated creatine kinase levels in adult Fbn2 null mice, indicating ongoing cycles of muscle injury. On a C57Bl/6 background, Fbn2 null mice showed severe defects in musculature, leading to neonatal death from respiratory failure. These new findings demonstrate that loss of fibrillin-2 results in phenotypes similar to those found in congenital muscular dystrophies and that FBN2 should be considered as a candidate gene for recessive congenital muscular dystrophy. Both in vivo and in vitro evidence associated muscle abnormalities and accumulation of white fat in Fbn2 null mice with abnormally activated BMP signaling. Genetic rescue of reduced muscle mass and accumulation of white fat in Fbn2 null mice was accomplished by deleting a single allele of Bmp7. In contrast to other reports that activated BMP signaling leads to muscle hypertrophy, our findings demonstrate the exquisite sensitivity of BMP signaling to the fibrillin-2 extracellular environment during early postnatal muscle development. New evidence presented here suggests that fibrillin-2 can sequester BMP complexes in a latent state.
Low temperature phase transitions and crystal structure of Na0.5CoO2
Q. Huang,M. L. Foo,J. W. Lynn,H. W. Zandbergen,G. Lawes,Yayu Wang,B. H. Toby,A. P. Ramirez,N. P. Ong,R. J. Cava
Physics , 2004, DOI: 10.1088/0953-8984/16/32/016
Abstract: The crystal structure of Na0.5CoO2, determined by powder neutron diffraction, is reported. The structure consists of layers of edge-shared CoO6 octahedra in a triangular lattice, with Na ions occupying ordered positions in the interleaving planes. The Na ions form one-dimensional zigzag chains. Two types of Co ions, which differ only subtly in their coordination by oxygen, are also found in chains. Specific heat measurements show that the transitions observed at 87 K and 53 K in the resistivity and magnetic susceptibility are accompanied by changes in entropy. Electron diffraction studies suggest that the 87K transition may have a structural component.
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