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Geographic Variability (geographic + variability)
Selected AbstractsBreast cancer survivors in the United StatesCANCER, Issue 9 20092005-201, Geographic Variability, Time Trends Abstract BACKGROUND: Breast cancer continues to place a significant burden on the healthcare system. Regional prevalence measures are instrumental in the development of cancer control policies. Very few population-based cancer registries are able to provided local, long-term incidence and follow-up information that permits the direct calculation of prevalence. Model-based prevalence estimates are an alternative when this information is lacking or incomplete. The current work represents a comprehensive collection of female breast cancer prevalence from 2005 to 2015 in the United States and the District of Columbia (DC). METHODS: Breast cancer prevalence estimates were derived from state-specific cancer mortality and survival data using a statistical package called the Mortality-Incidence Analysis Model or MIAMOD. Cancer survival models were derived from the Surveillance, Epidemiology, and End Results Program data and were adjusted to represent state-specific survival. Comparisons with reported incidence for 39 states and DC had validated estimates. RESULTS: By the year 2010, 2.9 million breast cancer survivors are predicted in the US, equaling 1.85% of the female population. Large variability in prevalent percentages was reported between states, ranging from 1.4% to 2.4% in 2010. Geographic variability was reduced when calculating age-standardized prevalence proportions or cancer survivors by disease duration, including 0 to 2 years and 2 to 5 years. The residual variability in age-adjusted prevalence was explained primarily by the state-specific, age-adjusted breast cancer incidence rates. State-specific breast cancer survivors are expected to increase from 16% to 51% in the decennium from 2005 to 2015 and by 31% at the national level. CONCLUSIONS: To the authors' knowledge, the current study is the first to provide systematic estimations of breast cancer prevalence in all US states through 2015. The estimated levels and time trends were consistent with the available population-based data on breast cancer incidence, prevalence, and population aging. Cancer 2009. © 2009 American Cancer Society. [source] Biogeography of bacteria associated with the marine sponge Cymbastela concentricaENVIRONMENTAL MICROBIOLOGY, Issue 3 2005Michael W. Taylor Summary Recent debate regarding microbial biogeography has focused largely on free-living microbes, yet those microbes associated with host organisms are also of interest from a biogeographical perspective. Marine eukaryotes and associated bacteria should provide ideal systems in which to consider microbial biogeography, as (i) bacteria in seawater should be able to disperse among individuals of the same host species, yet (ii) potential for adaptation to particular hosts (and thus speciation) also exists. We used 16S rDNA-DGGE (denaturing gradient gel electrophoresis) to examine geographic variability in bacterial community composition in the marine sponge Cymbastela concentrica. Denaturing gradient gel electrophoresis banding patterns (and phylogenetic analysis of excised DGGE bands) indicated different communities in Cymbastela concentrica from tropical versus temperate Australia. In contrast, communities were very similar over a 500-km portion of the sponge's temperate range. Variation in bacterial community composition was also considered with respect to ocean current patterns. We speculate that the divergent communities in different parts of the sponge's range provide evidence of endemism attributed to host association, although variation in environmental factors such as light and temperature could also explain the observed results. Interestingly, bacterial communities in seawater varied much less between tropical and temperate locations than did those in C. concentrica, supporting the concept of widespread dispersal among these free-living microbes. [source] Geoarchaeological insights gained from surficial geologic mapping, middle Moche Valley, PeruGEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 5 2003Gary Huckleberry We present the results of detailed surficial geologic mapping for a 10 km2 area of alluvial (quebrada) deposits located in the middle Moche Valley of Peru, where archaeological features and deposits provide cross-cutting relationships and numerical age control for late Holocene erosion and deposition associated with El Niño. Despite surfaces containing clasts that are heavily pitted and cracked due to salt weathering, archaeological and 14C dates indicate that most quebrada landforms in the study area are late Holocene in age and may reflect enhanced alluviation associated with increased El Niño activity beginning ca. 6000 cal yr B.P. Our study provides criteria for correlative dating of other Holocene landforms in the Moche Valley area but urges caution in long-distance (>100 km) correlation because of geographic variability in surface weathering. Surficial geologic mapping aided by archaeological age control allows improved understanding of the rates of landscape change important to the development of complex irrigation-based societies in the Peruvian Desert. © 2003 Wiley Periodicals, Inc. [source] Phylogeography and environmental correlates of a cap on reproduction: teat number in a small marsupial, Antechinus agilisMOLECULAR ECOLOGY, Issue 5 2007J. BECKMAN Abstract Natural selection should optimize litter size in response to the distribution and abundance of resources during breeding. In semelparous, litter-bearing antechinuses, teat number limits litter size. Consequently adaptation has been inferred in explaining intraspecific, geographic variability in teat number for several Antechinus spp. The phylogeography of teat number variation and associated genetic divergence were assessed in A. agilis using nine microsatellites and mitochondrial cytochrome b sequence data. Six-teat Otway Range animals were divergent in microsatellite allele identity and frequencies: samples from three Otway six-teat sites demonstrated significantly greater similarity genetically to those from six-teat animals ,250 km to the west, than to nearby Otway 10-teat samples, or to the six-teat animals at Wilsons Promontory. Gene flow between Otway phenotypes appears to have been limited for sufficient time to enable different microsatellite alleles to evolve. Nonetheless, nuclear genetic evidence suggested only incomplete reproductive isolation, and mitochondrial DNA (mtDNA) haplotypes showed no association with teat number. Other populations across the range were no more genetically differentiated from one another than expected from geographic separation. Principal components and distance-based redundancy analyses found an association between environmental variables and geographic distribution of A. agilis teat number , six-teat animals inhabit more temperate forests, whilst those with more teats experience greater seasonality. The apparent restricted breeding between phenotypically distinct animals, together with phylogenetically separate groups of six-teat animals in different locations with similar environments, are consistent with the hypothesis that adaptation to different habitats drives teat number variation in A. agilis. [source] Geographic variation in opioid prescribing for acute, work-related, low back pain and associated factors: A multilevel analysisAMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 2 2009Barbara S. Webster BSPT, PA-C Abstract Background Given reports about variation in opioid prescribing, concerns about increasing opioid use and its associated negative consequences make understanding the sources of variability important. The aims of the study were to assess the extent of and factors associated with geographic variation in early opioid prescribing for acute, work-related, low back pain (LBP). Methods Cases were selected from workers compensation administrative data filed between January 1, 2002 and December 31, 2003 and included claims from states with more than 40 cases. Early opioid prescribing (one or more prescriptions within first 15 days) was the outcome. Weighted coefficient of variation (wCOV) estimated geographic variation, and multilevel models measured variability controlling for individual and contextual factors. Results Of the 8,262 claimants, 21.3% received at least one early opioid prescription. Significant between-state variation was found (wCOV,=,53%), from 5.7% (Massachusetts) to 52.9% (South Carolina). Seventy-nine percent of the between-state variation was explained by three contextual factors: state household income inequality (prevalence ratio [PR] 1.06, 95% confidence interval [CI],=,1.01, 1.12), number of physicians per capita (PR 0.99, 95% CI,=,0.98, 0.99), and workers compensation cost containment effort score (PR 1.12, 95% CI,=,1.02, 1.24). Individual-level factors, including severity, explained only a small portion of the geographic variability. Conclusion Geographic variation of early opioid prescribing for acute LBP is important and almost fully explained by state-level contextual factors. The study suggests that clinician and patient interaction and the subsequent decision to use opioids are substantially framed by social conditions and control systems. Am. J. Ind. Med. 52:162,171, 2009. © 2008 Wiley-Liss, Inc. [source] Latitudinal variation in cranial dimorphism in Macaca fascicularisAMERICAN JOURNAL OF PRIMATOLOGY, Issue 2 2010Michael A. Schillaci Abstract This study examines latitudinal and insular variation in the expression of sexual dimorphism in cranial length in three geographical groupings of Macaca fascicularis. In addition, the relationship between cranial length dimorphism (CLD) and sex-specific size is examined. The results of the study identified a significant relationship between CLD and latitude for only one of the three geographic groupings. Sex-specific relationships between cranial length and CLD were detected. The pattern of these relationships varied by geographic grouping. This study is important because it demonstrates that despite very similar levels of CLD in a single primate species, there exists important geographic variability in the correlates of that dimorphism. I suggest that geographically varying ecological factors may influence sex-specific natural selection and the intensity of CLD in M. fascicularis. Gaining a better understanding of this geographical variability will require that future research examines morphological variation, including CLD, within its corresponding ecological and social contexts. Such research should be comparative, and incorporate multiple geographically separated populations with disparate environmental settings. Am. J. Primatol. 72:152,160, 2010. © 2009 Wiley-Liss, Inc. [source] Inbreeding Coefficients for X-linked and Autosomal Genes in Consanguineous Marriages in Spanish Populations: The Case of Guipúzcoa (Basque Country)ANNALS OF HUMAN GENETICS, Issue 2 2009R. Calderón Summary Inbreeding patterns over the past two centuries have been studied more extensively in Spain and Italy than anywhere else in Europe. Consanguinity studies in mainland Spain have shown that populations settled along the Cantabrian cornice share inbreeding patterns that distinguish them from other populations further south. A visual representation of spatial variations of two key inbreeding variables is presented here for the first time via contour maps. This paper also analyzes time trends of mean inbreeding coefficients for X-linked (Fx) and autosomal genes (F) (1862,1995) together with variations in Fx/F ratios in Guipúzcoa, the most autochthonous Spanish Basque province. Because close cousin marriages are a mark of identity of the study population, we evaluated the contribution of uncle-niece/aunt-nephew (M12) and first cousin (M22) marriages to Fx and F values and compared the frequencies of M12 and M22 pedigree subtypes and their corresponding Fx/F ratios to those found in other Spanish populations. The mean Fx and F inbreeding levels in Guipúzcoa for the 134-year period analyzed were 1.51 × 10,3 and 1.04 × 10,3, respectively, and the Fx/F ratio was seen to be very stable over time. Our findings show that major similarities exist for close consanguineous marriage subtypes between Basque and non-Basque Spanish populations, despite significant geographic variability in terms of first cousin pedigrees. The distortion seems to be caused by Guipúzcoa. The Fx/F ratios for first cousins in Spanish populations were higher than expected (1.25), with values ranging from 1.34 to 1.48. The findings of the present study may be useful for advancing knowledge on the effects of the interaction between biology and culture and for exploring associations between mating patterns and the prevalence of certain diseases. [source] | |||||||||||||