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Significant Patterns (significant + pattern)
Selected AbstractsGeographical patterns of micro-organismal community structure: are diatoms ubiquitously distributed across boreal streams?OIKOS, Issue 1 2010Jani Heino A topic under intensive study in community ecology and biogeography is the degree to which microscopic, as well as macroscopic organisms, show spatially-structured variation in community characteristics. In general, unicellular microscopic organisms are regarded as ubiquitously distributed and, therefore, without a clear biogeographic signal. This view was summarized 75,years ago by Baas-Becking, who stated "everything is everywhere, but, the environment selects". Within the context of metacommunity theory, this hypothesis is congruent with the species sorting model. By using a broad-scale dataset on stream diatom communities and environmental predictor variables across most of Finland, our main aim was to test this hypothesis. Patterns of spatial autocorrelation were evaluated by Moran's I based correlograms, whereas partial regression analysis and partial redundancy analysis were used to quantify the relative importance of environmental and spatial factors on total species richness and on community composition, respectively. Significant patterns of spatial autocorrelation were found for all environmental variables, which also varied widely. Our main results were clear-cut. In general, pure spatial effects clearly overcame those of environmental effects, with the former explaining much more variation in species richness and community composition. Most likely, missing environmental variables cannot explain the higher predictive power of spatial variables, because we measured key factors that have previously been found to be the most important variables (e.g. pH, conductivity, colour, phosphorus, nitrogen) shaping the structure of diatom communities. Therefore, our results provided only limited support for the Baas-Becking hypothesis and the species sorting perspective of metacommunity theory. [source] Distribution and population genetic structure of the Mediterranean pine shoot beetle Tomicus destruens in the Iberian Peninsula and Southern FranceAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 2 2006Teresa Vasconcelos Abstract 1,The Mediterranean pine shoot beetle Tomicus destruens has long been indistinguishable from its congeneric Tomicus piniperda. Both species attack pines, and can be found in sympatry. The geographical distribution of T. destruens is still unclear in most of the Mediterranean Basin. 2,We aimed to describe the geographical distribution and zones of sympatry of both species in the Iberian Peninsula and France, and to study the molecular phylogeographical pattern of T. destruens. 3,Tomicus spp. adults were sampled in Portugal, Spain and France, and a portion of the mitochondrial genes COI and COII was sequenced for 84 individuals. Sequences were aligned to a data set previously obtained from French localities. 4,Tomicus destruens was found in all populations, except for one locality in Portugal and in the Landes (France). It was in sympatry with T. piniperda in two locations on Pinus pinaster and one location on Pinus radiata. 5,Within-population genetic diversity was high, but we found a significant pattern of spatial distribution of genetic variation, as well as a significant effect of the host tree. 6,The data suggest the existence of two glacial refugia, from which T. destruens recolonized its current range. One refugium was located in Portugal where the beetle probably evolved on P. pinaster. The corresponding haplotypes show a West,East frequency gradient. The other refugium was probably in the eastern range, where the beetles evolved on Pinus halepensis and P. pinea. The corresponding haplotypes show an East,West frequency gradient. [source] Changing Patterns of Drug and Alcohol Use in Fatally Injured Drivers in Washington StateJOURNAL OF FORENSIC SCIENCES, Issue 5 2006Eugene W. Schwilke B.S. ABSTRACT: We have previously reported on patterns of drug and alcohol use in fatally injured drivers in Washington State. Here we revisit that population to examine how drug use patterns have changed in the intervening 9 years. Blood and serum specimens from drivers who died within 4 h of a traffic accident between February 1, 2001, and January 31, 2002, were analyzed for illicit and therapeutic drugs and alcohol. Drugs when present were quantitated. Samples suitable for testing were obtained from 370 fatally injured drivers. Alcohol was detected above 0.01 g/100 mL in 41% of cases. The mean alcohol concentration for those cases was 0.17 g/100 mL (range 0.02,0.39 g/100 mL). Central nervous system (CNS) active drugs were detected in 144 (39%) cases. CNS depressants including carisoprodol, diazepam, hydrocodone, diphenhydramine, amitriptyline, and others were detected in 52 cases (14.1%), cannabinoids were detected in 47 cases (12.7%), CNS stimulants (cocaine and amphetamines) were detected in 36 cases (9.7%), and narcotic analgesics (excluding morphine which is often administered iatrogenically in trauma cases) were detected in 12 cases (3.2%). For those cases which tested positive for alcohol c. 40% had other drugs present which have the potential to cause or contribute to the driver's impairment. Our report also considers the blood drug concentrations in the context of their interpretability with respect to driving impairment. The data reveal that over the past decade, while alcohol use has declined, some drug use, notably methamphetamine, has increased significantly (from 1.89% to 4.86% of fatally injured drivers) between 1992 and 2002. Combined drug and alcohol use is a very significant pattern in this population and is probably overlooked in DUI enforcement programs. [source] Maternal caffeine consumption and risk of cardiovascular malformations,,BIRTH DEFECTS RESEARCH, Issue 7 2007Marilyn L. Browne Abstract BACKGROUND: The physiologic effects and common use of caffeine during pregnancy call for examination of maternal caffeine consumption and risk of birth defects. Epidemiologic studies have yielded mixed results, but such studies have grouped etiologically different defects and have not evaluated effect modification. METHODS: The large sample size and precise case classification of the National Birth Defects Prevention Study allowed us to examine caffeine consumption and specific cardiovascular malformation (CVM) case groups. We studied consumption of caffeinated coffee, tea, soda, and chocolate to estimate total caffeine intake and separately examined exposure to each caffeinated beverage. Smoking, alcohol, vasoactive medications, folic acid supplement use, and infant gender were evaluated for effect modification. Maternal interview reports for 4,196 CVM case infants overall and 3,957 control infants were analyzed. RESULTS: We did not identify any significant positive associations between maternal caffeine consumption and CVMs. For tetralogy of Fallot, nonsignificant elevations in risk were observed for moderate (but not high) caffeine intake overall and among nonsmokers (ORs of 1.3 to 1.5). Risk estimates for both smoking and consuming caffeine were less than the sum of the excess risks for each exposure. We observed an inverse trend between coffee intake and risk of atrial septal defect; however, this single significant pattern of association might have been a chance finding. CONCLUSIONS: Our study found no evidence for an appreciable teratogenic effect of caffeine with regard to CVMs. Birth Defects Research (Part A), 2007. © 2007 Wiley-Liss, Inc. [source] Assessment of infant physiology and neuronal development using magnetic resonance imagingCHILD: CARE, HEALTH AND DEVELOPMENT, Issue 2002B. Morgan Abstract Previous work has demonstrated both that there are substantial individual differences in the rate of physiological development, and that infants with risk factors for Sudden Infant Death Syndrome (SIDS) develop more slowly, suggesting that their increased vulnerability may be due to delayed neuronal development associated with compromised development in fetal or early neonatal life. This project aims to test the hypothesis that individual differences in the rate of physiological development of infants correlate with measurable differences in the rate of brain development as assessed by magnetic resonance imaging (MRI). Sixty infants were recruited to this study in three different groups that are known to have differing rates of physiological development. MRI was performed successfully in 49 cases at 6 weeks of age without sedation. Forty-one of these cases had full follow-up (15 normal; 19 IUGR; 11 ,high risk'). Postnatal physiological development was assessed by measuring age-related deep body temperature patterns during sleep. Neuronal development was assessed by subjective analysis of MRI images and objective measurements relating to myelination using T1 and diffusion weighted (23 cases) MRI images. As expected the normal group acquired the adult temperature pattern earlier, but this was not statistically significant. All MRI scan appearances were within normal limits. Ranking cases subjectively in order of maturity revealed no significant pattern. The normal group had a significantly higher myelination score than the IUGR and ,high risk' groups (P = 0.001). This trend was also shown by the diffusion weighted myelination score but did not reach statistical significance. No significant differences were seen in both the subjective and objective MRI measurements and development of nocturnal temperature patterns. The results suggest there may be differences in neurodevelopment between the different groups at 6 weeks of age but these are not linked to late development of temperature patterns. It is therefore unlikely that this related to a global delay in maturation. [source] Pulp and paper mill effluents induce distinct gene expression changes linked to androgenic and estrogenic responses in the fathead minnow (Pimephales promelas)ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 2 2010Julieta Werner Abstract Although effluent treatment systems within pulp and paper mills remove many toxicants and improve wastewater quality, there is a need to understand and quantify the effectiveness of the treatment process. At a combined news and kraft pulp and paper mill in northwestern Ontario, Canada, fathead minnow (FHM) reproduction and physiology were examined before, during, and after a short-term (6-d) exposure to 10% (v/v) untreated kraft mill effluent (UTK), 25% (v/v) secondary treated kraft mill effluent (TK), and 100% (v/v) combined mill outfall (CMO). Although UTK exposure significantly decreased egg production, neither TK nor CMO caused any reproductive changes. The expression of six genes responsive to endocrine-disrupting compounds, stress, or metals was then examined in livers of these fish using real-time polymerase chain reaction. In female FHMs, none of the three effluents induced significant expression changes in any genes investigated. By contrast, in males there were significant increases in the mRNA levels of androgen receptor, estrogen receptor (ER) ,, and cytochrome P4501A (CYP1A) upon UTK and TK exposure but no changes in ER, or vitellogenin (VTG) gene expression, whereas CMO exposure significantly increased the mRNA levels of ER,, VTG, and CYP1A. Together, these results suggest that kraft effluent before and after biological treatment contained compounds able to induce androgenic effects in FHMs, and that combination of kraft and newsmill effluents eliminated the androgenic compounds while inducing distinct and significant patterns of gene expression changes that were likely due to estrogenic compounds produced by the newsmill. Environ. Toxicol. Chem. 2010;29:430,439. © 2009 SETAC [source] Measuring the components of competition along productivity gradientsJOURNAL OF ECOLOGY, Issue 2 2007MARK V. WILSON Summary 1Controversy surrounds the measurement of competition intensity. Moreover, when biomass varies systematically along productivity and other environmental gradients, common indices of competitive outcome mask important ecological interactions. 2This study presents two indices derived from how neighbours interact with target plants. The first, relative crowding, increases directly with the abundance of neighbours present and decreases inversely with the potential size and vigour of the target plant itself. The second, interaction strength, is the integral of suppression of the target by neighbours over the range of neighbour abundance. Relative crowding and interaction strength are derived independently, but when multiplied produce the commonly used relative competitive index, showing the biological underpinnings of the relative competition index in terms of crowding and strength of interaction. Since the new indices of relative crowding and interaction strength explicitly account for the amount of neighbour biomass, they serve as a valid method to track the effects of changing habitat conditions on the components of competition. 3The new indices are applied to three published data sets. In each case, relative crowding increased with standing crop. In one case competition was reported as unchanged along a productivity gradient, whereas the new indices show that relative crowding and interaction strength both had significant patterns, but their effects were counteracting. These results do not fit current theories of competition. Further empirical studies are needed to see if competition theory needs revision. 4Separating the mechanisms of competition into relative crowding and strength of interaction reveals previously hidden patterns that help bring to light underlying processes of competition along productivity gradients. [source] Fertility transition in Ghana: looking back and looking forwardPOPULATION, SPACE AND PLACE (PREVIOUSLY:-INT JOURNAL OF POPULATION GEOGRAPHY), Issue 6 2006Samuel Agyei-Mensah Abstract It is widely accepted that while the fertility transition is underway in sub-Saharan Africa, the pattern of change differs widely in both time and space. This paper examines the case of Ghana, regarded as the vanguard in the West African fertility transition. Based largely on analyses of Demographic and Health Survey data as well as localised studies, significant patterns emerge. One puzzling finding is that the increase in modern contraception usage has not kept pace with the declines in fertility. The paper suggests that this mismatch can be explained either by an increase in induced abortions, reduced exposure to sexual relations (perhaps due to HIV), or misreporting of contraceptive use. The paper also highlights the considerable geographical diversity in the ongoing fertility transition. The Northern region is still in the pre-transition stage, with little decline in fertility to date. In contrast, the pace of decline has been very rapid in the Greater Accra region. The factors underlying these patterns and the future trajectory of the fertility transition are discussed. It is argued that the fertility transition may be more leisurely in the near future than in the recent past. Among the factors working against future fertility decline are the stability in the infant mortality rate, the stall in fertility desires, and the low patronage of modern contraceptives especially in rural areas. Copyright © 2006 John Wiley & Sons, Ltd. [source] Economic intensification and degenerative joint disease: Life and labor on the postcontact north coast of PeruAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2009Haagen D. Klaus Abstract This study tests the hypothesis that the colonial economy of the Lambayeque region of northern coastal Peru was associated with a mechanically strenuous lifestyle among the indigenous Mochica population. To test the hypothesis, we documented the changes in the prevalence of degenerative joint disease (or DJD) in human remains from the late pre-Hispanic and colonial Lambayeque Valley Complex. Comparisons were made using multivariate odds ratios calculated across four age classes and 11 principle joint systems corresponding to 113 late pre-Hispanic and 139 postcontact adult Mochica individuals. Statistically significant patterns of elevated postcontact DJD prevalence are observed in the joint systems of the shoulder, elbow, wrist, and knee. More finely grained comparison between temporal phases indicates that increases in prevalence were focused immediately following contact in the Early/Middle Colonial period. Analysis of DJD by sex indicates postcontact males experienced greater DJD prevalence than females. Also, trends between pre- and postcontact females indicate nearly universally elevated DJD prevalence among native colonial women. Inferred altered behavioral uses of the upper body and knee are contextualized within ecological, ethnohistoric, and ethnoarchaeological frameworks and appear highly consistent with descriptions of the local postcontact economy. These patterns of DJD appear to stem from a synergism of broad, hemispheric level sociopolitical alterations, specific changes to Mochica activity and behavior, regional economic intensification, and local microenvironmental characteristics, which were all focused into these biological outcomes by the operation of a colonial Spanish political economy on the north coast of Peru from A.D. 1536 to 1751. Am J Phys Anthropol, 2009. © 2009 Wiley-Liss, Inc. [source] Contact in the Andes: Bioarchaeology of systemic stress in colonial Mórrope, PeruAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2009Haagen D. Klaus Abstract The biocultural interchange between the Eastern and Western Hemispheres beginning in the late fifteenth century initiated an unprecedented adaptive transition for Native Americans. This article presents findings from the initial population biological study of contact in the Central Andes of Peru using human skeletal remains. We test the hypothesis that as a consequence of Spanish colonization, the indigenous Mochica population of Mórrope on the north coast of Peru experienced elevated systemic biological stress. Using multivariate statistical methods, we examine childhood stress reflected in the prevalence of linear enamel hypoplasias and porotic hyperostosis, femoral growth velocity, and terminal adult stature. Nonspecific periosteal infection prevalence and D30+/D5+ ratio estimations of female fertility characterized adult systemic stress. Compared to the late pre-Hispanic population, statistically significant patterns of increased porotic hyperostosis and periosteal inflammation, subadult growth faltering, and depressed female fertility indicate elevated postcontact stress among both children and adults in Mórrope. Terminal adult stature was unchanged. A significant decrease in linear enamel hypoplasia prevalence may not indicate improved health, but reflect effects of high-mortality epidemic disease. Various lines of physiological, archaeological, and ethnohistoric evidence point to specific socioeconomic and microenvironmental factors that shaped these outcomes, but the effects of postcontact population aggregation in this colonial town likely played a fundamental role in increased morbidity. These results inform a model of postcontact coastal Andean health outcomes on local and regional scales and contribute to expanding understandings of the diversity of indigenous biological variation in the postcontact Western Hemisphere. Am J Phys Anthropol, 2009. © 2008 Wiley-Liss, Inc. [source] Space,time patterns of co-variation of biodiversity and primary production in phytoplankton guilds of coastal marine environmentsAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue 6 2003Maria Rosaria Vadrucci Abstract 1.The relevance of biodiversity to ecosystem processes is a major topic in ecology. Here, we analyse the relationship between biodiversity and productivity of the nano- and micro-phytoplankton guilds in coastal marine ecosystems. 2.The patterns of variation of species richness, diversity and primary productivity (as 14C assimilation) were studied in two marine areas: a eutrophic,mesotrophic area beside the River Po delta (northern Adriatic) and an oligotrophic area around the Salento peninsula (southern Adriatic,Ionian). The study was carried out at 23 sites in the northern area and at 45 sites in the southern area. Sites were arranged on expected spatial and temporal gradients of primary productivity variation, according to distance from the coast, optical depths and seasonal period. 3.167 taxa were identified in the northern area and 153 taxa in the southern area. In both areas, the taxonomic composition of the nano- and micro-phytoplankton guilds exhibited greater temporal than spatial variation. The latter was much higher in the southern area than in the northern area (average dissimilarity between stations being 70.7±0.8% and 44.7±4.2% respectively). 4.Primary productivity varied in space and time on the gradients considered. Phytoplankton species richness and diversity exhibited significant patterns of variation in space and time; overall, these were inversely related to the primary productivity patterns in the northern area, whereas they were directly related in the southern area. 5.The small individual size and the high turnover rate of phytoplankton are likely to underlie the observed relationships, which emphasized a threshold response to nutrient enrichment in agreement with the ,paradox of enrichment'. Under resource enrichment conditions, the high turnover of producers leads to hierarchical partitioning of the available resources with an increasing dominance of a few species. Therefore, the relationship observed here seems likely to be explained by the complementarity hypothesis. Copyright © 2003 John Wiley & Sons, Ltd. [source] The Source Provenance of Bronze Age and Roman pottery from CyprusARCHAEOMETRY, Issue 1 2002B. Gomez Archaeological interpretations of ancient economies have been strengthened by chemical analyses of ceramics, which provide the clearest evidence for economic activity, and comprise both the objects of exchange and its means. Pottery is often manufactured from local materials, but its compositional diversity typically prevents significant patterns of resource utilization from being identified. Centrally located and positioned on traditional shipping routes, Cyprus maintained ties with and supplied a variety of distinctive ceramic products to the major commercial centres in the eastern Mediterranean throughout Antiquity. We analysed two Cypriot .ne wares and a variety of utilitarian pottery, as well as samples of extant Cypriot clays to determine source provenance. These chemical analyses provide an objective indication of the origins of ancient (Bronze Age and Roman) ceramics manufactured on Cyprus. The distribution of the probable clay sources and the links between pottery style and the material environment also afford a perspective on the spatial organization of large-scale pottery production on the island. Compositional analysis provides the means to assemble geographies of pottery production and to unravel the interregional system of exchange that operated in Antiquity, but the ability to accomplish these tasks is predicated on systematic analyses of ceramic products and raw materials that are found far beyond the bounds of individual archaeological sites. [source] Seasonal birth patterns in myositis subgroups suggest an etiologic role of early environmental exposuresARTHRITIS & RHEUMATISM, Issue 8 2007Leora J. Vegosen Objective To evaluate whether seasonal early environmental exposures might influence later development of autoimmune disease, by assessing distributions of birth dates in groups of patients with idiopathic inflammatory myopathies (IIMs). Methods We assessed birth patterns in groups of patients with juvenile-onset IIM (n = 307) and controls (n = 3,942) who were born between 1970 and 1999, and in groups of patients with adult-onset IIM (n = 668) and controls (n = 6,991) who were born between 1903 and 1982. Birth dates were analyzed as circular data. Seasonal clustering was assessed by the Rayleigh test, and differences between groups by a rank-based uniform scores test. Results The overall birth distributions among patients with juvenile IIM and among patients with adult IIM did not differ significantly from those among juvenile and adult controls, respectively. Some subgroups of patients with juvenile IIM had seasonal birth distributions. Hispanic patients with juvenile-onset IIM had a seasonal birth pattern (mean birth date October 16) significantly different from that of Hispanic controls (P = 0.002), who had a uniform birth distribution, and from that of non-Hispanic patients with juvenile-onset IIM (P < 0.001), who had a mean birth date of May 2. Juvenile dermatomyositis patients with p155 autoantibody had a birth distribution that differed significantly from that of p155 antibody,negative juvenile dermatomyositis patients (P = 0.003). Juvenile IIM patients with the HLA risk factor allele DRB1*0301 had a birth distribution significantly different from those without the allele (P = 0.021). Similar results were observed for juvenile and adult IIM patients with the linked allele DQA1*0501, versus juvenile and adult IIM patients without DQA1*0501, respectively. No significant patterns in birth season were found in other subgroups. Conclusion Birth distributions appear to have stronger seasonality in juvenile than in adult IIM subgroups, suggesting greater influence of perinatal exposures on childhood-onset illness. Seasonal early-life exposures may influence the onset of some autoimmune diseases later in life. [source] | |||||||||||||