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Selected AbstractsUsing Websites to Disseminate Research on Urban SpatialitiesGEOGRAPHY COMPASS (ELECTRONIC), Issue 6 2009Gillian Rose This paper reviews a selection of websites that explore urban geographies. Many sites use the web as a depository for large amounts of research data. However, many are using websites to disseminate research findings, and the paper focuses on these. It suggests that, thus far, there are three significant ways in which urban researchers are exploiting the potentialities of web technologies to interpret urban spaces: by evoking a sense of the complexity of urban spatialities; by inviting site visitors to engage actively and performatively with the research materials; and by emphasising the sensory qualities of urban spaces. The paper discusses how one website in particular invites its visitors to engage with complex, sensory urban spatialities. The paper compares geographers' use of collage and montage as part of this discussion, and ends by reflecting on current work and commenting on its future development. [source] Validation of Numerical Ground Water Models Used to Guide Decision MakingGROUND WATER, Issue 2 2004Ahmed E. Hassan Many sites of ground water contamination rely heavily on complex numerical models of flow and transport to develop closure plans. This complexity has created a need for tools and approaches that can build confidence in model predictions and provide evidence that these predictions are sufficient for decision making. Confidence building is a long-term, iterative process and the author believes that this process should be termed model validation. Model validation is a process, not an end result. That is, the process of model validation cannot ensure acceptable prediction or quality of the model. Rather, it provides an important safeguard against faulty models or inadequately developed and tested models. If model results become the basis for decision making, then the validation process provides evidence that the model is valid for making decisions (not necessarily a true representation of reality). Validation, verification, and confirmation are concepts associated with ground water numerical models that not only do not represent established and generally accepted practices, but there is not even widespread agreement on the meaning of the terms as applied to models. This paper presents a review of model validation studies that pertain to ground water flow and transport modeling. Definitions, literature debates, previously proposed validation strategies, and conferences and symposia that focused on subsurface model validation are reviewed and discussed. The review is general and focuses on site-specific, predictive ground water models used for making decisions regarding remediation activities and site closure. The aim is to provide a reasonable starting point for hydrogeologists facing model validation for ground water systems, thus saving a significant amount of time, effort, and cost. This review is also aimed at reviving the issue of model validation in the hydrogeologic community and stimulating the thinking of researchers and practitioners to develop practical and efficient tools for evaluating and refining ground water predictive models. [source] Ibis: a flexible and efficient Java-based Grid programming environmentCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 7-8 2005Rob V. van Nieuwpoort Abstract In computational Grids, performance-hungry applications need to simultaneously tap the computational power of multiple, dynamically available sites. The crux of designing Grid programming environments stems exactly from the dynamic availability of compute cycles: Grid programming environments (a) need to be portable to run on as many sites as possible, (b) they need to be flexible to cope with different network protocols and dynamically changing groups of compute nodes, while (c) they need to provide efficient (local) communication that enables high-performance computing in the first place. Existing programming environments are either portable (Java), or flexible (Jini, Java Remote Method Invocation or (RMI)), or they are highly efficient (Message Passing Interface). No system combines all three properties that are necessary for Grid computing. In this paper, we present Ibis, a new programming environment that combines Java's ,run everywhere' portability both with flexible treatment of dynamically available networks and processor pools, and with highly efficient, object-based communication. Ibis can transfer Java objects very efficiently by combining streaming object serialization with a zero-copy protocol. Using RMI as a simple test case, we show that Ibis outperforms existing RMI implementations, achieving up to nine times higher throughputs with trees of objects. Copyright © 2005 John Wiley & Sons, Ltd. [source] A Nationwide Assessment of the Biodiversity Value of Uganda's Important Bird Areas NetworkCONSERVATION BIOLOGY, Issue 1 2006HERBERT TUSHABE AIAs; complementariedad; congruencia trans-taxón; selección de sitios de conservación Abstract:,BirdLife International's Important Bird Areas (IBA) program is the most developed global system for identifying sites of conservation priority. There have been few assessments, however, of the conservation value of IBAs for nonavian taxa. We combined past data with extensive new survey results for Uganda's IBAs in the most comprehensive assessment to date of the wider biodiversity value of a tropical country's IBA network. The combined data set included more than 35,000 site × species records for birds, butterflies, and woody plants at 86 Ugandan sites (23,400 km2), including 29 of the country's 30 IBAs, with data on additional taxa for many sites. Uganda's IBAs contained at least 70% of the country's butterfly and woody plant species, 86% of its dragonflies and 97% of its birds. They also included 21 of Uganda's 22 major vegetation types. For butterflies, dragonflies, and some families of plants assessed, species of high conservation concern were well represented (less so for the latter). The IBAs successfully represented wider biodiversity largely because many have distinctive avifaunas and, as shown by high cross-taxon congruence in complementarity, such sites tended to be distinctive for other groups too. Cross-taxon congruence in overall species richness was weaker and mainly associated with differences in site size. When compared with alternative sets of sites selected using complementarity-based, area-based, or random site-selection algorithms, the IBA network was efficient in terms of the number of sites required to represent species but inefficient in terms of total area. This was mainly because IBA selection considers factors other than area, however, which probably improves both the cost-effectiveness of the network and the persistence of represented species. Resumen:,El programa de Áreas de Importancia para las Aves (AIAs) de Birdlife International es el sistema global más desarrollado para la identificación de sitios de prioridad para la conservación. Sin embargo, ha habido pocas evaluaciones del valor de conservación de las AIAs para taxa no aviares. En la evaluación más integral, hasta la fecha, del valor de la biodiversidad en general de la red de AIAs de un país tropical, combinamos datos antiguos con los resultados de muestreos extensivos recientes de las AIAs de Uganda. El conjunto de datos combinados incluyó más de 35000 registros de sitios x especies de aves, mariposas y plantas leñosas en 86 sitios en Uganda (23400 km2), incluyendo 29 de las 30 AIAs del país, con datos sobre taxa adicionales en muchos sitios. Las AIAs de Uganda contenían por lo menos un 70% de las especies de mariposas y plantas leñosas del país, 86% de sus libélulas y 97% de sus aves. También incluyeron 21 de los 22 principales tipos de vegetación. En las mariposas, libélulas y algunas de las familias de plantas evaluadas, la representación de especies de alto interés para la conservación fue buena (menor en las plantas). Las Áreas de Importancia para las Aves representaron exitosamente a la biodiversidad en general principalmente porque muchas tienen avifaunas distintivas y, como muestra la alta congruencia trans-taxón en complementariedad, tales sitios tendieron a ser distintivos para otros grupos también. La congruencia trans-taxón en la riqueza de especies total fue más débil y se asoció principalmente con diferencias en el tamaño del sitio. Cuando se compara con conjuntos alternativos de sitios seleccionados mediante algoritmos basados en complementariedad, área o selección aleatoria de sitios, la red de AIAs fue eficiente en términos del número de sitios requeridos para representar especies, pero ineficiente en términos del área total. Sin embargo, esto se debió principalmente a que la selección de AIA considera factores distintos al área que probablemente mejoran tanto la efectividad de la red como la persistencia de las especies representadas. [source] An evaluation of logistic regression models for predicting amphipod toxicity from sediment chemistryENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 10 2005Jeffrey D. Wetherington Abstract An empirical screening level approach was developed to assess the probability of toxicity to benthic organisms associated with contaminated sediment exposure. The study was based on simple logistic regression models (LRMs) of matching sediment chemistry and toxicity data retrieved from a large database of field-collected sediment samples contaminated with multiple chemicals. Three decisions were made to simplify the application of LRMs to sediment samples contaminated with multiple chemicals. First, percent mortality information associated with each sediment sample was condensed into a dichotomous response (i.e., toxic or nontoxic). Second, each LRM assumed that toxicity was attributable to a single contaminant. Third, individual contaminants present at low concentrations were excluded from toxic sediment samples. Based on an analysis of the National Sediment Inventory database, the LRM approach classified 55% of nontoxic sediments as toxic (i.e., false-positives). Because this approach has been used to assess the probability of benthic toxicity as reported by the U.S. Environmental Protection Agency (U.S. EPA), the resultant estimates of potential toxicity convey a misleading impression of the increased hazard that sediments pose to the health of aquatic organisms at many sites in the United States. This could result in important resources needlessly being diverted from truly contaminated sites to evaluate and possibly remediate sediments at uncontaminated sites. [source] Toward detoxifying mercury-polluted aquatic sediments with rice genetically engineered for mercury resistanceENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 12 2003Andrew C. P. Heaton Abstract Mercury contamination of soil and water is a serious problem at many sites in the United States and throughout the world. Plant species expressing the bacterial mercuric reductase gene, merA, convert ionic mercury, Hg(II), from growth substrates to the less toxic metallic mercury, Hg(0). This activity confers mercury resistance to plants and removes mercury from the plant and substrates through volatilization. Our goal is to develop plants that intercept and remove Hg(II) from polluted aquatic systems before it can undergo bacterially mediated methylation to the neurotoxic methylmercury. Therefore, the merA gene under the control of a monocot promoter was introduced into Oryza sativa L. (rice) by particle gun bombardment. This is the first monocot and first wetland-adapted species to express the gene. The merA -expressing rice germinated and grew on semisolid growth medium spiked with sufficient Hg(II) to kill the nonengineered (wild-type) controls. To confirm that the resistance mechanism was the conversion of Hg(II) to Hg(0), seedlings of merA -expressing O. sativa were grown in Hg(II)-spiked liquid medium or water-saturated soil media and were shown to volatilize significantly more Hg(0) than wild-type counterparts. Further genetic manipulation could yield plants with increased efficiency to extract soil Hg(II) and volatilize it as Hg(0) or with the novel ability to directly convert methylmercury to Hg(0). [source] Using regional exposure criteria and upstream reference data to characterize spatial and temporal exposures to chemical contaminants,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 4 2000Susan M. Cormier Abstract Analyses of biomarkers in fish were used to evaluate exposures among locations and across time. Two types of references were used for comparison, an upstream reference sample remote from known point sources and regional exposure criteria derived from a baseline of fish from reference sites throughout Ohio, USA. Liver, bile, and blood were sampled from white suckers (Catostomus commersoni) and common carp (Cyprinus carpio) collected during 1993 and 1996 in the Ottawa River near Lima, Ohio. Levels of exposure were measured for petroleum by naphthalene-type metabolites, combustion by-products by benzo[a]pyrene-type metabolites, coplanar organic compounds by ethoxyresorufin- O -deethylase (EROD) activity, and urea by blood urea nitrogen (BUN) levels. The four biomarkers analyzed proved effective in determining differences between reference and polluted sampling sites, between geographically close (<0.5 km) sites, and between sampling years at sites common in both years. Calculated exposure criteria levels of the polycyclic aromatic hydrocarbon bile metabolites were found to be a conservative approximation of levels from a designated reference site and could thereby permit comparison of biomarker levels of fish from the Ottawa River to a regional reference level. Polycyclic aromatic hydrocarbon bile metabolite and EROD activity levels were more reflective of spatial patterns of contamination than BUN, although all biomarkers indicated differences overtime. Biomarkers from white suckers seemed to be more responsive in detecting changes in contaminant levels than the same biomarkers from common carp. Lower levels in 1996 of all biomarkers at many sites suggested lower exposures than in 1993 and could be indicative of some improvement over the period. [source] Regionalisation of chemical variability in European mountain lakesFRESHWATER BIOLOGY, Issue 12 2009LLUÍS CAMARERO Summary 1. We carried out a coordinated survey of mountain lakes covering the main ranges across Europe (including Greenland), sampling 379 lakes above the local tree line in 2000. The objectives were to identify the main sources of chemical variability in mountain lakes, define a chemical classification of lakes, and develop tools to extrapolate our results to regional lake populations through an empirical regionalisation or upscaling of chemical properties. 2. We investigated the main causes of chemical variability using factor analysis (FA) and empirical relationships between chemistry and several environmental variables. Weathering, sea salt inputs, atmospheric deposition of N and S, and biological activity in soils of the catchment were identified as the major drivers of lake chemistry. 3. We tested discriminant analysis (DA) to predict the lake chemistry. It was possible to use the lithology of the catchments to predict the range of Ca2+ and SO42, into which a lake of unknown chemistry will decrease. Lakes with lower SO42, concentrations have little geologically derived S, and better reflect the variations in atmospheric S loading. The influence of marine aerosols on lakewater chemistry could also be predicted from the minimum distance to the sea and altitude of the lakes. 4. The most remarkable result of FA was to reveal a factor correlated to DOC (positively) and NO3, (negatively). This inverse relationship might be the result either of independent processes active in the catchment soils and acting in an opposite sense, or a direct interaction, e.g. limitation of denitrification by DOC availability. Such a relationship has been reported in the recent literature in many sites and at all scales, appearing to be a global pattern that could reflect the link between the C and N cycles. 5. The concentration of NO3, is determined by both atmospheric N deposition and the processing capacity of the catchments (i.e. N uptake by plants and soil microbes). The fraction of the variability in NO3, because of atmospheric deposition is captured by an independent factor in the FA. This is the only factor showing a clear pattern when mapped over Europe, indicating lower N deposition in the northernmost areas. 6. A classification has been derived which takes into account all the major chemical features of the mountain lakes in Europe. FA provided the criteria to establish the most important factors influencing lake water chemistry, define classes within them, and classify the surveyed lakes into each class. DA can be used as a tool to scale up the classification to unsurveyed lakes, regarding sensitivity to acidification, marine influence and sources of S. [source] A dating intercomparison study on Late Stone Age coastal midden deposits, South AfricaGEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 6 2008Mark D. Bateman The southern and western coastlines of South Africa have an extensive archaeological record with many sites associated with widespread eolian deposits. While much of this rich archaeological record is based on cave sites, evidence of Late Stone Age occupation is additionally preserved in the form of open-site shell middens. We present here a comparative study of the application of amino acid racemization (AAR), optically stimulated luminescence (OSL), and radiocarbon analyses to three Late Stone Age (LSA) midden sites found within dunes on the southern coastline of South Africa. Preliminary geochronological analyses suggest that middens offer opportunity to fill in gaps in what is still a fragmentary archaeological record. Results show OSL and radiocarbon ages in good agreement, illustrating the potential to date not only the middens but also the surrounding dunes that constituted the dwelling sites. AAR results show increasing ratios with age and also that the application of paired shell and "whole rock" AAR can provide insights into the degree of biogenic sediment recycling at buried midden sites. However, the work also highlights that caution is required when OSL sampling sediment associated with middens which may have undergone human disturbance and that further work is required to improve the regional marine reservoir correction for radiocarbon dating in this part of South Africa. The study also illustrates that AAR will only provide useful data provided that middens have been sufficiently deeply buried to overcome fluctuations in environmental variables that affect the racemization rate and that inter-genus comparisons should be avoided. © 2008 Wiley Periodicals, Inc. [source] Geochemistry and petrography of basalt grindstones from the Karak Plateau, central JordanGEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 1 2004Brandon G. Watts Seventeen basalt grindstone fragments from central Jordan's Karak Plateau were studied. Most of these artifacts are vesicular or amygdaloidal with calcite as the dominant mineral filling the voids. The major minerals are olivine (with iddingsite rims), plagioclase, clinopyroxene, magnetite, and apatite. Glass is present in some samples. One basalt fragment is quite different in appearance and composition and may have come from flows closer to the Dead Sea. Grindstone fragment compositions plot in the tephrite-basanite and basalt fields. A plot of the concentrations of niobium, zirconium, and yttrium reveal that the sample compositions plot in the "within-plate alkali basalt" and "within-plate tholeiite" fields. The acquisition of basalts for preparing such implements appears to have been random. Some may have been introduced through trade and migration. Archaeological and environmental studies on the Karak Plateau are urgently needed because Jordan's population growth and economic development are destroying many sites and their environmental contexts. © 2004 Wiley Periodicals, Inc. [source] Parental lung cancer as predictor of cancer risks in offspring: Clues about multiple routes of harmful influence?INTERNATIONAL JOURNAL OF CANCER, Issue 3 2006Kari Hemminki Abstract The carcinogenic effects of active smoking have been demonstrated for many sites, but the effects of passive smoking and exposures during pregnancy and breastfeeding are less well documented. We examined whether 0,70-year-old offspring of parents with lung cancer are at a risk of cancer that cannot be explained by their smoking or familial risk. It was assumed that known target sites for tobacco carcinogenesis would be affected, if any. The nationwide Swedish Family-Cancer Database with cancers recorded from 1958 to 2002 was used to calculate age-specific standardized incidence ratios (SIRs). Among offspring of affected mothers, increased risks were observed for upper aerodigestive (SIR 1.45), nasal (2.93), lung (1.71) and bladder (1.52) cancers and for kidney cancer (6.41) in one age group. The risk of bladder cancer was found in younger age groups than that of lung cancer. Cancers at many of these sites, but not the kidney or the bladder, were in excess in offspring of affected fathers. Nasal cancer was even increased when either parent was diagnosed with lung cancer; the highest risk was for nasal adenoid cystic carcinoma (7.73). The data suggest that passive smoking during childhood is associated with an increase risk of nasal cancer. For bladder and kidney cancers, a contribution by tobacco carcinogens is implicated through breastfeeding and in utero exposure. © 2005 Wiley-Liss, Inc. [source] The use of size,frequency diagrams to characterize prehistoric fish catches and to assess human impact on inshore fisheriesINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 1-2 2001Foss Leach Abstract Archaeological collections of fish bones from previously excavated sites in New Zealand are being re-examined and selected bones measured in order to estimate original fish size, reconstruct prehistoric fish catches and assess human impact on the fishery over the course of about 800 years of New Zealand prehistory. Several problems hamper this research, such as small sample sizes, lack of significant stratigraphy at many sites, inconsistent field collection strategies and failure to retain all of the material after initial analysis. Although some common fish species show a significant decline in mean size between pre-European and early historic samples on the one hand, and modern populations on the other, we have found little support for the common belief that there was a decline in mean fish size during the pre-European period. We have observed increases over time in the mean size of snapper (Pagrus auratus), blue cod (Parapercis colias) and undifferentiated species of Labridae from several sites scattered throughout New Zealand. Distinguishing between changes in fish population structures owing to natural processes, such as surface sea water changes, and those which are the result of human over-fishing is not simple, because both processes can operate simultaneously. We draw on modern fish quota management models to separate these processes. Important factors for each species are inshore biomass and the recruitment rate at different temperature regimes. In the case of blue cod, we find that there are signs in the catch diagrams of changes in fishing technology, and that 30,80% of catches are undersized fish in terms of modern management criteria. Copyright © 2001 John Wiley & Sons, Ltd. [source] Disruption of an exotic mutualism can improve management of an invasive plant: varroa mite, honeybees and biological control of Scotch broom Cytisus scoparius in New ZealandJOURNAL OF APPLIED ECOLOGY, Issue 2 2010Quentin Paynter Summary 1.,A seed-feeding biocontrol agent Bruchidius villosus was released in New Zealand (NZ) to control the invasive European shrub, broom Cytisus scoparius, in 1988 but it was subsequently considered unable to destroy sufficient seed to suppress broom populations. We hypothesized that an invasive mite Varroa destructor, which has caused honeybee decline in NZ, may cause pollinator limitation, so that the additional impact of B. villosus might now reach thresholds for population suppression. 2.,We performed manipulative pollination treatments and broad-scale surveys of pollination, seed rain and seed destruction by B. villosus to investigate how pollinator limitation and biocontrol interact throughout the NZ range of broom. 3.,The effect of reduced pollination in combination with seed-destruction was explored using a population model parameterized for NZ populations. 4.,Broom seed rain ranged from 59 to 21 416 seeds m,2 from 2004 to 2008, and was closely correlated with visitation frequency of honeybees and bumblebees. Infestation of broom seeds by B. villosus is expected to eventually reach 73% (the average rate observed at the localities adjacent to early release sites). 5.,The model demonstrated that 73% seed destruction, combined with an absence of honeybee pollination, could cause broom extinction at many sites and, where broom persists, reduce the intensity of treatment required to control broom by conventional means. 6.,Nevertheless, seed rain was predicted to be sufficient to maintain broom invasions over many sites in NZ, even in the presence of the varroa mite and B. villosus, largely due to the continued presence of commercial beehives that are treated for varroa mite infestation. 7.,Synthesis and applications. Reduced pollination through absence of honeybees can reduce broom seed set to levels at which biocontrol can be more effective. To capitalize on the impact of the varroa mite on feral honeybees, improved management of commercial beehives (for example, withdrawal of licences for beekeepers to locate hives on Department of Conservation land) could be used as part of a successful integrated broom management programme at many sites in NZ. [source] Conservation status and causes of decline of the threatened New Zealand Long-tailed Bat Chalinolobus tuberculatus (Chiroptera: Vespertilionidae)MAMMAL REVIEW, Issue 2 2000Colin F. J. O'Donnell ABSTRACT Historical anecdotes and preliminary monitoring since 1990 indicate that New Zealand Long-tailed Bats (Chalinolobus tuberculatus, Vespertilionidae) are now rare or absent at many sites where formerly they were common. Chalinolobus tuberculatus appeared to be common throughout New Zealand in the 1800s but by 1900,30 it was becoming scarce in many districts. Formal surveys in the South Island since 1990 either failed to find C. tuberculatus, or recorded bats in low numbers. Of eight sites where transect counts were undertaken, bats were recorded frequently at two sites (45,66% of counts; Eglinton and Dart Valleys), rarely at four sites (2.4,10.7% of counts), and were not recorded at the remaining two sites despite considerable survey effort. Of 10 sites where stationary counts using automatic detector units were used, no C. tuberculatus were recorded in three areas (153 nights combined), they were found rarely at six sites (2.1,21.0% of nights; 461 nights combined) and were recorded commonly only in the Eglinton Valley (85% of 120 nights). Assertions that C. tuberculatus are ,common' and that the conservation status is ,secure' are questionable and this review supports suggestions that the species should be classed as ,Vulnerable'. Possible causes of decline have been suggested including clearance and logging of lowland forests, predation by introduced mammals and owls, competition for roost sites by introduced mammals, birds and wasps, and human interference and disturbance at roosting sites. However, authors' claims have all been speculative and unsubstantiated. There has been no research undertaken to quantify these claims, and this is required urgently. The results of these preliminary surveys provide a new baseline against which future population trends might be compared. Increased effort using standardized monitoring techniques, applied at a national level, is required to confirm the possible trends and to help identify the best sites where conservation managers may attempt to restore the population level. [source] Non-homogeneous infinitely many sites discrete-time model with exact coalescentMATHEMATICAL METHODS IN THE APPLIED SCIENCES, Issue 6 2010Adam Bobrowski Abstract Kingman's coalescent is among the most fertile concepts in mathematical population genetics. However, it only approximates the exact coalescent process associated with the Wright,Fisher model, in which the ancestry of a sample does not have to be a binary tree. The distinction between the approximate and exact coalescent becomes important when population size is small and time has to be measured in discrete units (generations). In the present paper, we explore the exact coalescent, with mutations following the infinitely many sites model. The methods used involve random point processes and generating functionals. This allows obtaining joint distributions of segregating sites in arbitrary intervals or collections of intervals, and generally in arbitrary Borel subsets of two or more chromosomes. Using this framework it is possible to find the moments of the numbers of segregating sites on pairs of chromosomes, as well as the moments of the average of the number of pairwise differences, in the form that is more general than usually. In addition, we demonstrate limit properties of the first two moments under a range of demographic scenarios, including different patterns of population growth. This latter part complements results obtained earlier for Kingman's coalescent. Finally, we discuss various applications, including the analysis of fluctuation experiments, from which mutation rates of biological cells can be inferred. Copyright © 2009 John Wiley & Sons, Ltd. [source] Impact of irrigation on malaria in Africa: paddies paradoxMEDICAL AND VETERINARY ENTOMOLOGY, Issue 1 2001J. N. Ijumba Summary The high population growth rate of the African continent has led to an increased demand for food and is in danger of outstripping agricultural production. In order to meet this need, many governments have sought ways of improving food production by initiating large-scale irrigation projects, involving reclamation of arid and semi-arid areas for the cultivation of crops. Although crop irrigation promises one solution to alleviating hunger and encourages economic growth, irrigation has often been blamed for aggravating disease in local communities. Malaria is one of the major tropical diseases associated with irrigation schemes, and changes in the transmission pattern of this disease following irrigation development have been a perennial subject of debate. It has often been assumed that high numbers of malaria vector Anopheles mosquitoes (Diptera: Culicidae) resulting from irrigation schemes lead inevitably to increased malaria in local communities. However, recent studies in Africa have revealed a more complex picture. Increased numbers of vectors following irrigation can lead to increased malaria in areas of unstable transmission, where people have little or no immunity to malaria parasites, such as the African highlands and desert fringes. But for most of sub-Saharan Africa, where malaria is stable, the introduction of crop irrigation has little impact on malaria transmission. Indeed, there is growing evidence that for many sites there is less malaria in irrigated communities than surrounding areas. The explanation for this finding is still unresolved but, in some cases at least, can be attributed to displacement of the most endophilic and anthropophilic malaria vector Anopheles funestus Giles by An. arabiensis Patton with lower vectorial capacity, as the latter thrives more than the former in ricefields. Similarly, among members of the An. gambiae complex, some cytotypes of An. gambiae sensu stricto are more vectorial than others. For example, the Mopti form has high vectorial capacity and breeds perennially in irrigated sites, whereas the savanna form is often sympatric but more seasonal. Also we suggest that many communities near irrigation schemes benefit from the greater wealth created by these schemes. Consequently irrigation communities often have greater use of bednets, better access to improved healthcare and receive fewer infective bites compared with those outside such development schemes. Thus, in most cases, irrigation schemes in Africa do not appear to increase malaria risk, except in areas of unstable transmission. However, developers should take the opportunity to improve health-care facilities for local communities when planning irrigation schemes wherever they occur. [source] Microsatellite variation within and among North American lineages of Phragmites australisMOLECULAR ECOLOGY, Issue 7 2003K. Saltonstall Abstract Over the past century, the spread of the common reed (Phragmites australis) has had a dramatic impact on wetland communities across North America. Although native populations of Phragmites persist, introduced invasive populations have dominated many sites and it is not clear if the two types can interbreed. This study compares patterns of differentiation in 10 microsatellite loci among North American and European Phragmites individuals with results obtained from sequencing of noncoding chloroplast DNA. Three population lineages (native, introduced and Gulf Coast) were previously identified in North America from chloroplast DNA and similar structuring was found in the nuclear genome. Each lineage was distinguished by unique alleles and allele combinations and the introduced lineage was closely related to its hypothesized source population in Europe. Size homoplasy and diagnostic base substitutions distinguishing lineages were evident at several loci, further emphasizing that native, introduced and Gulf Coast North American Phragmites lineages are genetically distinct. Gene flow between lineages was low and invasive introduced populations do not represent a hybrid population type. [source] Brief communication: A probabilistic approach to age estimation from infracranial sequences of maturation,AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 4 2010Hélène Coqueugniot Abstract Infracranial sequences of maturation are commonly used to estimate the age at death of nonadult specimens found in archaeological, paleoanthropological, or forensic contexts. Typically, an age assessment is made by comparing the degree of long-bone epiphyseal fusion in the target specimen to the age ranges for different stages of fusion in a reference skeletal collection. While useful as a first approximation, this approach has a number of shortcomings, including the potential for "age mimicry," being highly dependent on the sample size of the reference sample and outliers, not using the entire fusion distribution, and lacking a straightforward quantitative way of combining age estimates from multiple sites of fusion. Here we present an alternative probabilistic approach based on data collected on 137 individuals, ranging in age from 7- to 29-years old, from a documented skeletal collection from Coimbra, Portugal. We then use cross validation to evaluate the accuracy of age estimation from epiphyseal fusion. While point estimates of age can, at least in some circumstances, be both accurate and precise based on the entire skeleton, or many sites of fusion, there will often be substantial error in these estimates when they derive from one or only a few sites. Because a probabilistic approach to age estimation from epiphyseal fusion is computationally intensive, we make available a series of spreadsheets or computer programs that implement the approach presented here. Am J Phys Anthropol 142:655,664, 2010. © 2010 Wiley-Liss, Inc. [source] A geochemical study of bituminous mixtures from Failaka and Umm an-Namel (Kuwait), from the Early Dilmun to the Early Islamic periodARABIAN ARCHAEOLOGY AND EPIGRAPHY, Issue 2 2007Jacques Connan This paper is the last in a series presenting geochemical analyses of fragments of bituminous mixtures excavated from archaeological sites in Kuwait. The first was devoted to bituminous boat remains from the Ubaid-related Neolithic site of H3, As-Sabiyah, while the second dealt with bituminous amalgams from the Partho-Sasanian site of cAkkaz, a former island now joined to the south side of Kuwait Bay. This, the third, refers to bitumen-bearing samples from two other islands, Failaka and Umm an-Namel, and covers a time span including the Early Dilmun period, the Kassite period and the Hellenistic to Early Islamic periods. The composition of the bituminous amalgams was studied in detail. The proportions of soluble and insoluble organic matter as well as vegetal organic matter were evaluated. Mineralogical composition by X-Ray diffraction and thin-section analysis was used to estimate the mineral input in the bituminous mixtures. It can be confirmed that the recipes used in the preparation of these bituminous amalgams comply with those traditionally used in antiquity, as seen at many sites in Mesopotamia and the Gulf. Analysis of the soluble organic matter, and especially its ,,saturates'' fraction, provided sterane and terpane distributions and the measurement of diagnostic molecular ratios. These data, complemented by the isotopic composition of asphaltenes, allowed the identification of the sources of the bitumen, by calibration with numerous references from Iran and northern Iraq (oil seeps, bitumen from archaeological sites). It was established that the bitumen from Failaka and Umm an-Namel was mainly imported from central Iraq (Hit-Abu Jir) and northern Iraq (around Mosul). One sample of oil-stained sand, dating to the Early Dilmun period, originated from Burgan and thus documents small-scale imports from inland Kuwait. These results, and those of previous analyses, agree with the geopolitical context of the Early Dilmun, Kassite and Hellenistic periods, and the maritime trade routes that linked Mesopotamia to the settlements of the Gulf and beyond. The paper concludes with an overview of recent bitumen provenance analyses, and discerns chronological patterns in the distribution of Iraqi and Iranian bitumen in the Gulf and Indian Ocean, from the Neolithic to the Islamic periods. [source] Consequences of soil compaction for seedling establishment: Implications for natural regeneration and restorationAUSTRAL ECOLOGY, Issue 8 2005I. E. BASSETT Abstract Soil compaction can affect seedling root development by decreasing oxygen availability and increasing soil strength. However, little quantitative information is available on the compaction tolerances of non-crop native species. We investigated the effects of soil compaction on establishment and development of two New Zealand native species commonly used in restoration programmes; Cordyline australis (Agavaceae) (cabbage tree) a fleshy rooted species, and Leptospermum scoparium (Myrtaceae) (manuka) a very finely rooted species. Seedlings were grown in a range of soil compaction levels in growth cabinet experiments. Low levels of soil compaction (0.6 MPa) reduced both the number and speed of C. australis seedlings penetrating the soil surface. In contrast, L. scoparium seedlings showed improved establishment at an intermediate compaction level. Root and shoot growth of both species decreased with increasing soil strength, with L. scoparium seedlings tolerating higher soil strengths than did C. australis. Despite these results, soil strength accounted for only a small amount of variation in root length (R2 < 0.25), due to greater variability in growth at low soil strengths. Soil strengths of 0.6 MPa are likely to pose a barrier to C. australis regeneration. This is consistent with adaptation to organic and/or soft, waterlogged soils. Active intervention may be necessary to establish C. australis from seed on many sites previously in farmland. [source] Atlantic Forest Butterflies: Indicators for Landscape Conservation,BIOTROPICA, Issue 4b 2000Keith S. Brown Jr. ABSTRACT The Atlantic Forest region (wide sense) includes very complex tropical environments, increasingly threatened by extensive anthropogenic conversion (>90%). Ecologically specialized, short-generation insects (butterflies) are evaluated here as indicators for monitoring community richness, landscape integrity, and sustainable resource use in the region. The > 2100 butterfly species in the Atlantic Forest tegion have been censused in many sites over 35 years, giving comparable daily, weekly, monthly, and long-tetm site lists. The 21 most thoroughly studied sites include 218,914 species, of which half can be censused in a week or less. The butterfly communities are divided into six relatively distinct faunal regions, centered in the northeast, the central coastal tablelands, the southeast coastal plain, the mountains plus interior of the southeastern states, the central plateau, and the southern states. Species richness shows the highest values in coastal mountains from 15 to 23°S. Local butterfly communities show a high turnover, with 20 to 40 percent of the species, especially small Lycaenidae and Hesperiidae, recorded only as unstable populations or "tourists." Easily sampled species in the family Nymphalidae, and especially its bait-attracted subfamilies, are best correlated with the entire butterfly fauna and can be used as surrogates for species diversity. In most butterfly groups, species richness is well predicted by landscape connectivity alone, or by composite indices of environmental heterogeneity, natural disturbance, and (negatively) anthropogenic disturbance. Principal components and redundancy analyses showed that the richness and proportions of different butterfly groups in the local fauna are variably explained by disturbance, seasonality, temperature, vegetation, soils, and landscape connectivity. Various groups thus can be used as rapid indicators of different types of change in the community, its environment, and the landscape. Threatened and rare species also can be used as indicators of the most unique Atlantic Forest communities (paleoenvironments), which need special attention. RESUMO A região da Mata Atlantica latu senstt inclui ambientes tropicals muito complexes, cada vez mais amea¸ados por extensa conversão antrópica (>90%). Insetos pequenos, especializados, e de ciclo rápido (borboletas) são avaliados neste trabalho como indicadores para o monitoramento da tiqueza de comunidades, integridade de paisagens, e uso susten-tável de recursos na região. As >2100 espécies de borboletas na região da Mata Atlantica têrn sido recenseadas em muitos sítios durante os últimos 35 anos, dando listas comparáveis diárias, semanais, mensais e totais para cada sítio. Os 21 sítios mais intensivamente estudados incluem 218,914 espécies, das quais metade pode ser amostrada em uma semana ou menos. As comunidades de borboletas são divididas em seis subregiões faunísticas relativamente distintas, centradas no nordeste, nos tabuleiros baianos, no literal do sudeste, nas regiões montanhosas no interior dos estados do sudeste, no Planalto Central, e no estados do sul. A riqueza de espécies é maior nas serras costeiras entre 15 c 23°S. As comunidades locals de borboletas possuem alta reposi¸ão, com 20 a 40 por cento das espécies, especialmente os pequenos Lycaenidae e Hesperiidae, registradas em popula¸ões instáveis ou sendo apenas "turistas." As espécies facilmente amostradas na família Nymphalidae, especialmente as atraídas a iscas fermentadas, são mais correlacionadas com a riqueza total e podem ser usadas como estimadores da riqueza total no ambiente. Na maior parte dos grupos de borboletas, a riqueza de espécies é altamente correlacionada com conectividade simples da paisagem, e com índices compostos de heterogeneidade, perturba¸ão natural, e (negativamente) perturba¸ão total no ambiente. As análises de Componentes Principals e de Redundãncia mostram que as riquezas e proor¸ões de diferentes grupos de borboletas são variavelmente explicadas por pertba¸ão, sazonalidade, temperatura, vegeta¸ão, solos, e conectividade. Váries grupos podem assim ser úteis como indicadores rápidos de diferentes tipos de mudan¸as na comunidade, no seu ambiente, e na paisagem. Espécies raras e amea¸adas podem também ser usadas para indicar os sistemas mais únicos na região (paleoarnbientes), que necessitam de aten¸ão especial. 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