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Papers by angela hernandez
PLOS One, 2011
The estimated number of new HIV infections in the United States reflects the leading edge of the ... more The estimated number of new HIV infections in the United States reflects the leading edge of the epidemic. Previously, CDC estimated HIV incidence in the United States in 2006 as 56,300 (95% CI: 48,200-64,500). We updated the 2006 estimate and calculated incidence for 2007-2009 using improved methodology. We estimated incidence using incidence surveillance data from 16 states and 2 cities and a modification of our previously described stratified extrapolation method based on a sample survey approach with multiple imputation, stratification, and extrapolation to account for missing data and heterogeneity of HIV testing behavior among population groups. Estimated HIV incidence among persons aged 13 years and older was 48,600 (95% CI: 42,400-54,700) in 2006, 56,000 (95% CI: 49,100-62,900) in 2007, 47,800 (95% CI: 41,800-53,800) in 2008 and 48,100 (95% CI: 42,200-54,000) in 2009. From 2006 to 2009 incidence did not change significantly overall or among specific race/ethnicity or risk groups. However, there was a 21% (95% CI:1.9%-39.8%; p = 0.017) increase in incidence for people aged 13-29 years, driven by a 34% (95% CI: 8.4%-60.4%) increase in young men who have sex with men (MSM). There was a 48% increase among young black/African American MSM (12.3%-83.0%; p<0.001). Among people aged 13-29, only MSM experienced significant increases in incidence, and among 13-29 year-old MSM, incidence increased significantly among young, black/African American MSM. In 2009, MSM accounted for 61% of new infections, heterosexual contact 27%, injection drug use (IDU) 9%, and MSM/IDU 3%. Overall, HIV incidence in the United States was relatively stable 2006-2009; however, among young MSM, particularly black/African American MSM, incidence increased. HIV continues to be a major public health burden, disproportionately affecting several populations in the United States, especially MSM and racial and ethnic minorities. Expanded, improved, and targeted prevention is necessary to reduce HIV incidence.
Dermatologic Clinics, 2008
AbstractLow power spectral density of UWB (Ultra Wideband) systems allows spectrum reutilization... more AbstractLow power spectral density of UWB (Ultra Wideband) systems allows spectrum reutilization, but harmless coexistence with other radio systems must be guaranteed. Regulation establishes limits to emitted power spectral density necessary to assure that UWB devices ...
Abstract UWB technology is especially suitable for location and tracking applications due to its ... more Abstract UWB technology is especially suitable for location and tracking applications due to its high bandwidth, which allows a great accuracy on Time Of Arrival (TOA) estimation. Nevertheless, the achievement of this goal on multipath environments requires the design ...
In this paper, we analyze the behavior of several radio resource scheduling strategies under diff... more In this paper, we analyze the behavior of several radio resource scheduling strategies under different power and subcarrier allocation (PSA) and inter-cell interference (ICI) coordination schemes in mobile OFDMA networks. The aim is to test the capability of these scheduling strategies to deal with quality of service (QoS) requirements both in a single-service scenario or when a mixture of services takes place. This work shows that radio resource allocation schemes managing ICI have strong impact on the scheduling policy behavior, and that traffic delay is a key parameter to track in order to provide QoS when services with different delay constraints simultaneously occur.
IEEE Transactions on Consumer Electronics, 2008
Impulse Radio (IR) Ultra Wide-Band (UWB) is one of the most promising wireless technologies to de... more Impulse Radio (IR) Ultra Wide-Band (UWB) is one of the most promising wireless technologies to develop both indoor and outdoor location and tracking applications. Due to its high bandwidth and short duration pulses, UWB potentially allows a great accuracy in distance measurements based on Time Of Arrival (TOA) estimations. The main objective of this paper is to compare and to provide a qualitative and quantitative evaluation of different TOA-based distance estimation mechanisms joint to receiver architectures proposed for UWB systems. This comparison has been done in terms of accuracy and the effect of characteristic parameters of the transmitted signal, propagation conditions and signal-to-noise ratio has been analyzed. With this purpose a simulation tool has been developed, where the different receiver architectures, estimation mechanisms and channel models proposed on 802.15.4a have been implemented. 1
PLOS One, 2011
The estimated number of new HIV infections in the United States reflects the leading edge of the ... more The estimated number of new HIV infections in the United States reflects the leading edge of the epidemic. Previously, CDC estimated HIV incidence in the United States in 2006 as 56,300 (95% CI: 48,200-64,500). We updated the 2006 estimate and calculated incidence for 2007-2009 using improved methodology. We estimated incidence using incidence surveillance data from 16 states and 2 cities and a modification of our previously described stratified extrapolation method based on a sample survey approach with multiple imputation, stratification, and extrapolation to account for missing data and heterogeneity of HIV testing behavior among population groups. Estimated HIV incidence among persons aged 13 years and older was 48,600 (95% CI: 42,400-54,700) in 2006, 56,000 (95% CI: 49,100-62,900) in 2007, 47,800 (95% CI: 41,800-53,800) in 2008 and 48,100 (95% CI: 42,200-54,000) in 2009. From 2006 to 2009 incidence did not change significantly overall or among specific race/ethnicity or risk groups. However, there was a 21% (95% CI:1.9%-39.8%; p = 0.017) increase in incidence for people aged 13-29 years, driven by a 34% (95% CI: 8.4%-60.4%) increase in young men who have sex with men (MSM). There was a 48% increase among young black/African American MSM (12.3%-83.0%; p<0.001). Among people aged 13-29, only MSM experienced significant increases in incidence, and among 13-29 year-old MSM, incidence increased significantly among young, black/African American MSM. In 2009, MSM accounted for 61% of new infections, heterosexual contact 27%, injection drug use (IDU) 9%, and MSM/IDU 3%. Overall, HIV incidence in the United States was relatively stable 2006-2009; however, among young MSM, particularly black/African American MSM, incidence increased. HIV continues to be a major public health burden, disproportionately affecting several populations in the United States, especially MSM and racial and ethnic minorities. Expanded, improved, and targeted prevention is necessary to reduce HIV incidence.
Dermatologic Clinics, 2008
AbstractLow power spectral density of UWB (Ultra Wideband) systems allows spectrum reutilization... more AbstractLow power spectral density of UWB (Ultra Wideband) systems allows spectrum reutilization, but harmless coexistence with other radio systems must be guaranteed. Regulation establishes limits to emitted power spectral density necessary to assure that UWB devices ...
Abstract UWB technology is especially suitable for location and tracking applications due to its ... more Abstract UWB technology is especially suitable for location and tracking applications due to its high bandwidth, which allows a great accuracy on Time Of Arrival (TOA) estimation. Nevertheless, the achievement of this goal on multipath environments requires the design ...
In this paper, we analyze the behavior of several radio resource scheduling strategies under diff... more In this paper, we analyze the behavior of several radio resource scheduling strategies under different power and subcarrier allocation (PSA) and inter-cell interference (ICI) coordination schemes in mobile OFDMA networks. The aim is to test the capability of these scheduling strategies to deal with quality of service (QoS) requirements both in a single-service scenario or when a mixture of services takes place. This work shows that radio resource allocation schemes managing ICI have strong impact on the scheduling policy behavior, and that traffic delay is a key parameter to track in order to provide QoS when services with different delay constraints simultaneously occur.
IEEE Transactions on Consumer Electronics, 2008
Impulse Radio (IR) Ultra Wide-Band (UWB) is one of the most promising wireless technologies to de... more Impulse Radio (IR) Ultra Wide-Band (UWB) is one of the most promising wireless technologies to develop both indoor and outdoor location and tracking applications. Due to its high bandwidth and short duration pulses, UWB potentially allows a great accuracy in distance measurements based on Time Of Arrival (TOA) estimations. The main objective of this paper is to compare and to provide a qualitative and quantitative evaluation of different TOA-based distance estimation mechanisms joint to receiver architectures proposed for UWB systems. This comparison has been done in terms of accuracy and the effect of characteristic parameters of the transmitted signal, propagation conditions and signal-to-noise ratio has been analyzed. With this purpose a simulation tool has been developed, where the different receiver architectures, estimation mechanisms and channel models proposed on 802.15.4a have been implemented. 1