Relative Disparity Research Articles

Urban-rural inequality regarding drug prescriptions in primary care facilities - a pre-post comparison of the National Essential Medicines Scheme of China.

ObjectiveTo assess the impact of the National Essential Medicines Scheme (NEMS) with respect to urban-rural inequalities regarding drug prescriptions in primary care facilities.MethodsA stratified two-stage random sampling strategy was used to sample 23,040 prescriptions from 192 primary care facilities from 2009 to 2010. Difference-in-Difference (DID) analyses were performed to test the association between NEMS and urban-rural gaps in prescription patterns. Between-Group Variance and Theil Index were calculated to measure urban-rural absolute and relative disparities in drug prescriptions.ResultsThe use of the Essential Medicines List (EML) achieved a compliance rate of up to 90 % in both urban and rural facilities. An overall reduction of average prescription cost improved economic access to drugs for patients in both areas. However, we observed an increased urban-rural disparity in average expenditure per prescription. The rate of antibiotics and glucocorticoids prescription remained high, despite a reduced disparity between urban and rural facilities. The average incidence of antibiotic prescription increased slightly in urban facilities (62 to 63 %) and reduced in rural facilities (67 % to 66 %). The urban-rural disparity in the use of parenteral administration (injections and infusions) increased, albeit at a high level in both areas (44 %-52 %).ConclusionNEMS interventions are effective in reducing the overall average prescription costs. Despite the increased use of the EML, indicator performances with respect to rational drug prescribing and use remain poor and exceed the WHO/INRUD recommended cutoff values and worldwide benchmarks. There is an increased gap between urban and rural areas in the use of parenteral administration and expenditure per prescription.

Combining Transportation Network Models with Kernel Density Methods to Measure the Relative Spatial Accessibility of Pediatric Primary Care Services in Jefferson County, Kentucky

When considering access to healthcare, the question of whether the provider is available and accessible must be answered before the question of cost. Most contemporary techniques of estimating the spatial accessibility of healthcare cannot simultaneously take into account transportation times and the spatially distributed service capacity of healthcare providers. This paper creates the Comprehensive Spatial Accessibility Rank (CSAR) model to calculate a relative estimate of spatial accessibility that can account for both public and private transportation and the spatial distribution of a service provider's capacity for service in relation to the distribution of a study area's population. It uses data for Jefferson County, Kentucky to show how the CSAR model could be used to identify possible disparities in accessing pediatric primary healthcare services. The CSAR model is able to detect relative disparities between defined subpopulations and or geographic regions, allowing for the comparison of the effects of physical infrastructure in access.

Educational disparity in obesity among U.S. adults, 1984–2013

PurposeExamine the annual trends in educational disparity in obesity among U.S. adults aged 18 years and more from 1984 to 2013. MethodsSecondary data analysis of 6,147,379 participants in a repeated cross-sectional nationally representative health survey of U.S. adults. ResultsThe obesity prevalence among people with primary school or lower education increased from 17.46% or 3.41 times the prevalence among college graduates (5.12%) in 1984 to 36.16% or 1.73 times the prevalence among college graduates (20.94%) in 2013. In any given year, the obesity prevalence increased monotonically with lower education level. The obesity prevalence across education subgroups without a college degree gradually converged since early 2000s, whereas that between those subgroups and college graduates diverged since late 1980s. Absolute educational disparity in obesity widened by 60.84% to 61.14% during 1984–2013 based on the absolute concentration index and the slope index of inequality, respectively; meanwhile, relative educational disparity narrowed by 52.06% to 52.15% based on the relative index of inequality and the relative concentration index, respectively. The trends in educational disparity in obesity differed substantially by gender, race/ethnicity, age group, and obesity severity. ConclusionsThere was substantial educational disparity in obesity among U.S. adults and the trend differed across population subgroups.

Trends in Longevity in the Americas: Disparities in Life Expectancy in Women and Men, 1965-2010.

ObjectiveWe describe trends in life expectancy at birth (LE) and between-country LE disparities since 1965, in Latin America and the Caribbean.Methods & FindingsLE trends since 1965 are described for three geographical sub-regions: the Caribbean, Central America, and South America. LE disparities are explored using a suite of absolute and relative disparity metrics, with measurement consensus providing confidence to observed differences. LE has increased throughout Latin America and the Caribbean. Compared to the Caribbean, LE has increased by an additional 6.6 years in Central America and 4.1 years in South America. Since 1965, average reductions in between-country LE disparities were 14% (absolute disparity) and 23% (relative disparity) in the Caribbean, 55% and 51% in Central America, 55% and 52% in South America.ConclusionsLE in Latin America and the Caribbean is exceeding ‘minimum standard’ international targets, and is improving relative to the world region with the highest human longevity. The Caribbean, which had the highest LE and the lowest between-country LE disparities in Latin America and the Caribbean in 1965-70, had the lowest LE and the highest LE disparities by 2005-10. Caribbean Governments have championed a collaborative solution to the growing burden of non-communicable disease, with 15 territories signing on to the Declaration of Port of Spain, signalling regional commitment to a coordinated public-health response. The persistent LE inequity between Caribbean countries suggests that public health interventions should be tailored to individual countries to be most effective. Between- and within-country disparity monitoring for a range of health metrics should be a priority, first to guide country-level policy initiatives, then to contribute to the assessment of policy success.

US trends in survival disparities among adolescents and young adults with non-Hodgkin lymphoma.

Improvement in US survival rates among adolescents and young adults (AYAs, ages 15 through 39years inclusive) diagnosed with non-Hodgkin lymphoma (NHL) has been documented over the last two decades. We examined national trends in survival disparities for AYAs with NHL by race/ethnicity and socioeconomic status (SES, county-level poverty) to further understand NHL and to begin monitoring health outcome disparities for this disease. Surveillance Epidemiology and End Results data were used to calculate 5-year relative survival rates of AYAs diagnosed with NHL from 1992 to 2007 and followed through 2011. Absolute and relative disparities were computed using HD*Calc. Whether a significant linear trend was present was evaluated using Joinpoint. Analyses were replicated after excluding individuals with known HIV infection. The study sample included 9,573 total and 7,121 non-HIV cases of NHL. Five-year survival rates improved for all groups over time. Significant decreases were found in absolute disparities for race/ethnicity (non-HIV), in relative disparities for SES (total) and race/ethnicity (total and non-HIV) (all p<0.05). Survival rates of non-Hispanic Blacks and Hispanics remained below than those of non-Hispanic Whites throughout the time period. Absolute and relative disparities in 5-year survival narrowed for AYAs with NHL over the time period. To continue to promote this trend, future research should investigate factors, particularly diagnostic delays and barriers to care, which continue to contribute to SES and racial/ethnic differences in survival. These factors may be particularly relevant to identify given the recent Affordable Care Act, which is designed to increase access to medical services, particularly for young adults.

Racial and Regional Disparities in the Effect of the Affordable Care Act's Dependent Coverage Provision on Young Adult Trauma Patients

Disparities in trauma outcomes based on insurance and race are especially pronounced among young adults who have relatively high uninsured rates and incur a disproportionate share of trauma in the population. The 2010 Dependent Coverage Provision (DCP) of the Affordable Care Act (ACA) allowed young adults to remain on their parent's health insurance plans until age 26 years, leading to >3 million young adults gaining insurance. We investigated the impact of the DCP on racial disparities in coverage expansion among trauma patients. Using the 2007-2012 National Trauma Data Bank, we compared changes in coverage among 529,844 19- to 25-year-olds with 484,974 controls aged 27 to 34 years not affected by the DCP. Subgroup analyses were conducted by race and ethnicity and by census region. The pre-DCP uninsured rates among young adults were highest among black patients (48.1%) and Hispanic patients (44.3%), and significantly lower among non-Hispanic white patients (28.9%). However, non-Hispanic white young adults experienced a significantly greater absolute reduction in the uninsured rate (-4.9 percentage points) than black (-2.9; p = 0.01) and Hispanic (-1.7; p < 0.001) young adults. These absolute reductions correspond to a 17.0% relative reduction in the uninsured rate for white patients, 6.1% for black patients, and 3.7% for Hispanic patients. Racial disparities in the provision's impact on coverage among trauma patients were largest in the South and West census regions (p < 0.01). Although the DCP increased insurance coverage for young adult trauma patients of all races, both absolute and relative racial disparities in insurance coverage widened. The extent of these racial disparities also differed by geographic region. Although this policy produced overall progress toward greater coverage among young adults, its heterogeneous impact by race has important implications for future disparities research in trauma.

Mapping the cause-specific premature mortality reveals large between-districts disparity in Belgium, 2003-2009.

BackgroundReducing premature mortality is a crucial public health objective. The goal of this paper, beside updating previous mortality atlases with recent data, is to explore the relative between-districts disparity using a relative-scale map design.MethodsCauses of deaths and population data were provided by Statistics Belgium. All deaths occurring in the periods 1993–1999 and 2003–2009, in people aged 1–74 residing in Belgium were included. Age-adjusted rates by cause of death were computed for both periods; the 2003-2009 rates were classified using a relative scale with a 10% change between each level and represented on chloropleths maps with a green-to-red divergent colour scheme centred on the national mean. This particular design allows the comparability across all the maps since a same meaning is given to a specific colour. The variation coefficient and the decile ratio were calculated and compared between the 2 periods.ResultsA clear-cut regional divide at the disadvantage of Wallonia, and to some extent, of Brussels, was seen for all-cause, cardiovascular, cerebrovascular, diabetes, alcohol-related, mental and neurological diseases and non-transport accidents premature mortality. A NE-SW pattern parallel to the French border was observed for Lip, Oral Cavity, Pharynx, Larynx and oesophageal cancers, while various patterns are observed for the other cancers. The highest rates of road accident mortality are observed in the Southern districts. Many of those patterns are in continuity with earlier observations. However, the pattern of diabetes and mental and neurological diseases are new features. The variation coefficient and the decile ratios increased by 10% between the 1993-1997 and 2003-2009 periods.ConclusionsThe use of a relative scale in the maps highlights the importance of the between-districts disparity in premature mortality, with for most causes, a clear-cut regional divide at the disadvantage of Wallonia; this health gap results of complex interactions between various factors, including the socioeconomic context, cultural habits and environmental influences, as well as public health policies. It should be considered as a warning signal, warranting the attention of the policy makers. Meanwhile, these results also highlight the potential for improvement in the more disadvantaged regions.Electronic supplementary materialThe online version of this article (doi:10.1186/s13690-015-0060-5) contains supplementary material, which is available to authorized users.

Space perception of strabismic observers in the real world environment.

Space perception beyond the near distance range (>2 m) is important for target localization, and for directing and guiding a variety of daily activities, including driving and walking. However, it is unclear whether the absolute (egocentric) localization of a single target in the intermediate distance range requires binocular vision, and if so, whether having subnormal stereopsis in strabismus impairs one's ability to localize the target. We investigated this by measuring the perceived absolute location of a target by observers with normal binocular vision (n = 8; mean age, 24.5 years) and observers with strabismus (n = 8; mean age, 24.9 years) under monocular and binocular conditions. The observers used the blind walking-gesturing task to indicate the judged location of a target located at various viewing distances (2.73-6.93 m) and heights (0, 30, and 90 cm) above the floor. Near stereopsis was assessed with the Randot Stereotest. Both groups of observers accurately judged the absolute distance of the target on the ground (height = 0 cm) either with monocular or binocular viewing. However, when the target was suspended in midair, the normal observers accurately judged target location with binocular viewing, but not with monocular viewing (mean slant angle, 0.8° ± 0.5° vs. 7.4° ± 1.4°; P < 0.001, with a slant angle of 0° representing accurate localization). In contrast, the strabismic observers with poorer stereo acuity made larger errors in target localization in both viewing conditions, though with fewer errors during binocular viewing (mean slant angle, 2.7° ± 0.4° vs. 9.2° ± 1.3°; P < 0.0025). Further analysis reveals the localization error, that is, slant angle, correlates positively with stereo threshold during binocular viewing (r(2) = 0.479, P < 0.005), but not during monocular viewing (r(2) = 0.0002, P = 0.963). Locating a single target on the ground is sufficient with monocular depth information, but binocular depth information is required when the target is suspended in midair. Since the absolute binocular disparity information of the single target is weak beyond 2 m, we suggest the visual system localizes the single target using the relative binocular disparity information between the midair target and the visible ground surface. Consequently, strabismic observers with residual stereopsis localize a target more accurately than their counterparts without stereo ability.

Survival for patients with chronic leukemias in the US and Britain: Age-related disparities and changes in the early 21st century.

Chronic lymphocytic leukemia (CLL) and chronic myeloid leukemia (CML) are highly treatable conditions occurring primarily in older patients. Lower survival among older people has been reported in both conditions, but newer treatments may change both the overall survival rate and the relative risk associated with aging. Here, we examine survival for patients with CLL and CML in the United States (US) and England. Patients with CLL and CML were identified from the Surveillance, Epidemiology, and End Results (US) and National Cancer Registry (England). Five-year relative survival was calculated by major age group. Excess hazard ratios (EHR) by age were calculated for each condition, and multivariable analysis was performed to adjust for the following potential confounders: gender, race or ethnic group (US only), period of diagnosis, and a measure of socioeconomic deprivation (England only). Five-year relative survival increased for both CLL and CML in both England and the US between 1996-2000 and 2006-2010. However, relative age-related disparities persisted. For CLL, the EHR for death was 9.44 (7.84-11.36) in the US and 6.14 (5.65-6.68) in England for ages 85+ compared to ages 55-64. For CML, the EHR was 3.52 (3.17-3.90) in the US and 4.54 (4.13-4.98) in England for ages 75+ compared to ages 45-64. Survival improved for patients with chronic leukemias in the early 21st century. However, age-related disparities persist, despite clinical trial evidence that treatment in older adults with chronic leukemia can be safe and effective. Further research to determine the reasons for the lower survival in older patients and greater awareness of this problem may improve survival for older patients with chronic leukemia.

The visible ground surface as a reference frame for scaling binocular depth of a target in midair.

The natural ground surface carries texture information that extends continuously from one's feet to the horizon, providing a rich depth resource for accurately locating an object resting on it. Here, we showed that the ground surface's role as a reference frame also aids in locating a target suspended in midair based on relative binocular disparity. Using real world setup in our experiments, we first found that a suspended target is more accurately localized when the ground surface is visible and the observer views the scene binocularly. In addition, the increased accuracy occurs only when the scene is viewed for 5 s rather than 0.15 s, suggesting that the binocular depth process takes time. Second, we found that manipulation of the configurations of the texture-gradient and/or linear-perspective cues on the visible ground surface affects the perceived distance of the suspended target in midair. Third, we found that a suspended target is more accurately localized against a ground texture surface than a ceiling texture surface. This suggests that our visual system uses the ground surface as the preferred reference frame to scale the distance of a suspended target according to its relative binocular disparity.

Social inequalities in the utilization of maternal care in Bangladesh: Have they widened or narrowed in recent years?

BackgroundNotwithstanding the significant progress in reducing maternal mortality in recent years, social inequalities in the utilization of maternal care continue to be a challenge in Bangladesh. In this study, we aim to provide a comprehensive analysis of trends in social inequalities in utilization of antenatal care (ANC), facility based delivery (FBD), and skilled birth attendance (SBA) in Bangladesh between 1995 and 2010.MethodsData were extracted from the five latest rounds of Bangladesh Demographic Health Surveys (BDHS). The Theil index (T) and between-group variance (BGV) were used to calculate relative and absolute disparities in the utilization of three measures (ANC, FBD, and SBA) of maternal care across six administrative regions. The relative and slope indices of inequality (RII and SII, respectively) were also used to calculate wealth- and education-based inequality in the utilization of maternal care.ResultsThe results of the T-index suggest that relative inequality in SBA has declined by 0.2% per year. Nevertheless, the estimated BGV demonstrated that absolute inequalities in all three measures of maternal care have increased across administrative divisions. For all three measures of maternal care, the RII and SII indicated consistent socioeconomic inequalities favouring wealthier and more educated women. The adjusted RII suggested that wealth- and education-related inequalities for ANC declined by 9% and 6%, respectively, per year during the study period. The adjusted SII, however, showed that wealth- and education-related inequalities for FBD increased by 0.6% per year.ConclusionsAlthough socially disadvantaged mothers increased their utilization of care relative to mothers of higher socioeconomic status, the absolute gap in utilization of care between socioeconomic groups has increased over time. Our findings indicate that wealthier and more educated women, as well as those living in urban areas, are the major users of ANC, FBD and SBA in Bangladesh. Thus, priority focus should be given to implementing and evaluating interventions that benefit women who are poorer, less educated and live in rural areas.

Difference in health inequity between two population groups due to a social determinant of health.

The World Health Organization defines social determinants of health as “complex, integrated, and overlapping social structures and economic systems” that are responsible for most health inequities. Similar to the individual-level risk factors such as behavioral and biological risk factors that influence disease, we consider social determinants of health such as the distribution of income, wealth, influence and power as risk factors for risk of disease. We operationally define health inequity in a disease within a population due to a risk factor that is unfair and avoidable as the difference between the disease outcome with and without the risk factor in the population. We derive expressions for difference in health inequity between two populations due to a risk factor that is unfair and avoidable for a given disease. The difference in heath inequity between two population groups due to a risk factor increases with increasing difference in relative risks and the difference in prevalence of the risk factor in the two populations. The difference in health inequity could be larger than the difference in health outcomes between the two populations in some situations. Compared to health disparities which are typically measured and monitored using absolute or relative disparities of health outcomes, the methods presented in this manuscript provide a different, yet complementary, picture because they parse out the contributions of unfair and avoidable risk factors.

Reassessing Disparity in Access to Higher Education in Contemporary China

AbstractIn this commentary on the research note by Wang Xiaobing, Chengfang Liu, Linxiu Zhang, Yaojiang Shi and Scott Rozelle, “College is a rich, Han, urban, male club: research notes from a census survey of four tier one colleges in China,” I address several caveats in using the relative disparity index in assessing the extent of inequality in access to higher education. Based on these discussions, I point out the potential limitations existing in the empirical study of Wang and colleagues, and reassess the extent of disparity in college education opportunities in contemporary China using data from the 2010 Chinese General Social Survey. Although the descriptive patterns consolidate the study of Wang and colleagues, only household registration status is significantly associated with the likelihood of attending college. These findings indicate that disparities per gender, economic status, and ethnicity based on a limited number of colleges are likely to be subject to sampling errors. Finally, no interaction effects between socio-demographic factors are detected. I offer some reflections on the disproportionality approach in the research of education inequality.

Racial and ethnic disparities in cancer survival by neighborhood socioeconomic status in Surveillance, Epidemiology, and End Results (SEER) Registries.

Reducing cancer disparities is a major public health objective. Disparities often are discussed in terms of either race and ethnicity or socioeconomic status (SES), without examining interactions between these variables. Surveillance, Epidemiology, and End Results (SEER)-18 data, excluding Alaska Native and Louisiana registries, from 2002 to 2008, were used to estimate five-year, cause-specific survival by race/ethnicity and census tract SES. Differences in survival between groups were used to assess absolute disparities. Hazard ratios were examined as a measure of relative disparity. Interactions between race/ethnicity and neighborhood SES were evaluated using proportional hazard models. Survival increased with higher SES for all racial/ethnic groups and generally was higher among non-Hispanic white and Asian/Pacific Islander (API) than non-Hispanic black and Hispanic cases. Absolute disparity in breast cancer survival among non-Hispanic black vs non-Hispanic white cases was slightly larger in low-SES areas than in high-SES areas (7.1% and 6.8%, respectively). In contrast, after adjusting for stage, age, and treatment, risk of mortality among non-Hispanic black cases compared with non-Hispanic white cases was 21% higher in low-SES areas and 64% higher in high-SES areas. Similarly, patterns of absolute and relative disparity compared with non-Hispanic whites differed by SES for Hispanic breast cancer, non-Hispanic black colorectal cancer, and prostate cancer cases. Statistically significant interactions existed between race/ethnicity and SES for colorectal and female breast cancers. In health disparities research, both relative and absolute measures provide context. A better understanding of the interactions between race/ethnicity and SES may be useful in directing screening and treatment resources toward at-risk populations.

Abstract B84: Increasing disparities in breast cancer mortality for young black women in the U.S. from 1979-2010

Abstract Introduction: Though cancer mortality rates have declined in recent years, black women still have 40% higher breast cancer mortality rates than whites. In addition, black women and are more likely to be diagnosed with breast cancer before age 45 and to be diagnosed with later stage and more aggressive tumors. The purpose of this study was to examine mortality trends among black and white women younger than 50, comparing trends in racial disparities in breast cancer mortality to trends in mortality from other common cancers and cardiovascular disease (CVD). Methods: The CDC's Mortality Multiple Cause of Death Files were used to obtain cause specific death counts among women aged 20-49 years from 1979-2010. This data file includes information from US death certificates reported to the National Center for Health Statistics. Cause-specific mortality rates were calculated using underlying cause of death counts and U.S. Census intercensal population estimates for each year. Mortality rates were age standardized to the 2000 Standard Population using the direct method. ICD-9 and ICD-10 codes for cancer, CVD, breast cancer, cervical cancer, colorectal cancer, lung cancer, ischemic heart disease, and cerebrovascular disease (stroke) were reconciled using CDC guidelines. Since Hispanic ethnicity was not a required field on death certificates until 1989, race/ethnicity was categorized as black or white prior to 1989, and non-Hispanic white or non-Hispanic black for 1989 onward. Mortality rate-ratios were calculated comparing age-standardized mortality rates for blacks to those of whites. Results: Though mortality rates from both cancer and CVD declined from 1979-2010, black women aged 20-49 had significantly higher mortality rates than whites. In 2010, the cancer mortality rate was 40.6 per 100,000 among blacks compared to 28.8 per 100,000 among whites and the CVD mortality rate was 42.7 per 100,000 among blacks compared to 16.6 per 100,000 among whites. For CVD, the mortality rate-ratio comparing blacks to whites declined from a peak of 4.01 in 1989 to 2.57 in 2010. In contrast, the mortality rate-ratio was more stable for cancer, with a peak mortality rate-ratio of 1.58 in 1998 compared to 1.41 in 2010. Black women had higher mortality rates from breast cancer, colorectal cancer, cervical cancer, ischemic heart disease, and stroke compared to white women over the entire study period. Blacks had higher lung cancer mortality than whites through 2008, and similar or lower mortality rates 2009-2010. The mortality rate-ratio decreased over the study period for ischemic heart disease, stroke, cervical cancer and lung cancer. The mortality rate-ratio increased slightly for colorectal cancer through 2000, and declined after 2000. The mortality rate-ratio increased for breast cancer, from 1.36 in 1979 to 2.00 in 2010. Conclusions: Though mortality rates have declined over the past 30 years for women under 50, significant disparities in the two leading causes of death, cancer and CVD, remain. The persistence of disparities across diseases highlights the need to focus on improving health outcomes broadly, in addition to disease centered approaches, in order to prevent premature deaths among young women. The breast cancer mortality rate was two times greater among black women younger than 50 compared to white women, indicating a more profound disparity in younger women than older women. Furthermore, while relative disparities have decreased over time for most of the causes of death examined, the disparity in breast cancer mortality appears to be widening among young women. We plan to further quantify these trends using joinpoint regression to calculate the average percent change in mortality rates over time. Citation Format: Anne Marie McCarthy, Jianing Yang, Katrina Armstrong. Increasing disparities in breast cancer mortality for young black women in the U.S. from 1979-2010. [abstract]. In: Proceedings of the Sixth AACR Conference: The Science of Cancer Health Disparities; Dec 6–9, 2013; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2014;23(11 Suppl):Abstract nr B84. doi:10.1158/1538-7755.DISP13-B84

Stereoscopic depth from absolute and relative disparities

Stereoscopic depth from absolute and relative disparities

Reducing prostate cancer racial disparity: evidence for aggressive early prostate cancer PSA testing of African American men.

There is continuing controversy about prostate cancer testing and the recent American Urological Association guidelines. We hypothesize that the reduction and elimination of racial survival disparity among African American men (AAM; high-risk group) compared with European American men (EAM; intermediate-risk group) during the PSA testing era compared with the pre-PSA era strongly supports the use of PSA testing in AAM. We used Surveillance, Epidemiology, and End Results (SEER) data to investigate relative survival disparities between AAM and EAM. To evaluate pre-PSA testing era, we selected malignant first primary prostate cancer in AAM and EAM, all stages, diagnosed during 1973-1994. To evaluate relative survival disparities in the current PSA testing era, we selected malignant first primary local, regional, and distant stage prostate cancers diagnosed during 1998-2005 to calculate 5-year relative survival rates. Age-adjusted 5-year relative survival of prostate cancer diagnosed during 1973-1994 in the national SEER data revealed significantly shorter survival for AAM compared with EAM (P < 0.0001). The SEER-based survival analysis from 1995 to 2005 indicated no statistical difference in relative survival rates between AAM and EAM by year of diagnosis of local, regional, or distant stage prostate cancer. We conclude that the elimination of prostate cancer racial disparity of local, regional, and metastatic prostate cancer relative survival in the current PSA testing era compared with pre-PSA era as an endpoint to test PSA efficacy as a marker for prostate cancer diagnosis is evidence for aggressive testing of AAM. Evidence for screening AAM.

Relationship of racial composition and cancer risks from air toxics exposure in Memphis, Tennessee, U.S.A.

African Americans in the U.S. often live in poverty and segregated urban neighborhoods, many of which have dense industrial facilities resulting in high exposure to harmful air toxics. This study aims to explore the relationship between racial composition and cancer risks from air toxics exposure in Memphis/Shelby County, Tennessee, U.S.A. Air toxics data were obtained from 2005 National Air Toxics Assessment (NATA), and the demographic data, including racial composition, were extracted from the 2000 United States Census. The association was examined using multivariable geographically weighted regression (GWR) analysis. The risk difference between African American and White concentrated areas was defined as the absolute disparity, and the percent difference as the relative disparity. GWR analyses show that cancer risks increase with respect to increasing percent of African Americans at the census tract level. Individuals in African American concentrated tracts bear 6% more cancer risk burden than in White concentrated tracts. The distribution of major roads causes the largest absolute disparity and the distribution of industrial facilities causes the largest relative disparity. Effective strategies for reduction in environmental disparity should especially target sources of large absolute disparities.

Transcriptomes and proteomes define gene expression progression in pre-meiotic maize anthers.

Plants lack a germ line; consequently, during reproduction adult somatic cells within flowers must switch from mitotic proliferation to meiosis. In maize (Zea mays L.) anthers, hypoxic conditions in the developing tassel trigger pre-meiotic competence in the column of pluripotent progenitor cells in the center of anther lobes, and within 24 hr these newly specified germinal cells have patterned their surrounding neighbors to differentiate as the first somatic niche cells. Transcriptomes were analyzed by microarray hybridization in carefully staged whole anthers during initial specification events, after the separation of germinal and somatic lineages, during the subsequent rapid mitotic proliferation phase, and during final pre-meiotic germinal and somatic cell differentiation. Maize anthers exhibit a highly complex transcriptome constituting nearly three-quarters of annotated maize genes, and expression patterns are dynamic. Laser microdissection was applied to begin assigning transcripts to tissue and cell types and for comparison to transcriptomes of mutants defective in cell fate specification. Whole anther proteomes were analyzed at three developmental stages by mass spectrometric peptide sequencing using size-fractionated proteins to evaluate the timing of protein accumulation relative to transcript abundance. New insights include early and sustained expression of meiosis-associated genes (77.5% of well-annotated meiosis genes are constitutively active in 0.15 mm anthers), an extremely large change in transcript abundances and types a few days before meiosis (including a class of 1340 transcripts absent specifically at 0.4 mm), and the relative disparity between transcript abundance and protein abundance at any one developmental stage (based on 1303 protein-to-transcript comparisons).

Monocular and binocular edges enhance the perception of stereoscopic slant.

Gradients of absolute binocular disparity across a slanted surface are often considered the basis for stereoscopic slant perception. However, perceived stereo slant around a vertical axis is usually slow and significantly under-estimated for isolated surfaces. Perceived slant is enhanced when surrounding surfaces provide a relative disparity gradient or depth step at the edges of the slanted surface, and also in the presence of monocular occlusion regions (sidebands). Here we investigate how different kinds of depth information at surface edges enhance stereo slant about a vertical axis. In Experiment 1, perceived slant decreased with increasing surface width, suggesting that the relative disparity between the left and right edges was used to judge slant. Adding monocular sidebands increased perceived slant for all surface widths. In Experiment 2, observers matched the slant of surfaces that were isolated or had a context of either monocular or binocular sidebands in the frontal plane. Both types of sidebands significantly increased perceived slant, but the effect was greater with binocular sidebands. These results were replicated in a second paradigm in which observers matched the depth of two probe dots positioned in front of slanted surfaces (Experiment 3). A large bias occurred for the surface without sidebands, yet this bias was reduced when monocular sidebands were present, and was nearly eliminated with binocular sidebands. Our results provide evidence for the importance of edges in stereo slant perception, and show that depth from monocular occlusion geometry and binocular disparity may interact to resolve complex 3D scenes.