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Selected AbstractsNorepinephrine causes a pressure-dependent plasma volume decrease in clinical vasodilatory shockACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 7 2010A. NYGREN Background: Recent experimental studies have shown that a norepinephrine-induced increase in blood pressure induces a loss of plasma volume, particularly under increased microvascular permeability. We studied the effects of norepinephrine-induced variations in the mean arterial pressure (MAP) on plasma volume changes and systemic haemodynamics in patients with vasodilatory shock. Methods: Twenty-one mechanically ventilated patients who required norepinephrine to maintain MAP ,70 mmHg because of septic/postcardiotomy vasodilatory shock were included. The norepinephrine dose was randomly titrated to target MAPs of 60, 75 and 90 mmHg. At each target MAP, data on systemic haemodynamics, haematocrit, arterial and mixed venous oxygen content and urine flow urine were measured. Changes in the plasma volume were calculated as 100 × (Hctpre/Hctpost,1)/ (1,Hctpre), where Hctpre and Hctpost are haematocrits before and after intervention. Results: Norepinephrine doses to obtain target MAPs of 60, 75 and 90 mmHg were 0.20±0.18, 0.29±0.18 and 0.42±0.31 ,g/kg/min, respectively. From 60 to 90 mmHg, increases in the cardiac index (15%), systemic oxygen delivery index (25%), central venous pressure (CVP) (20%) and pulmonary artery occlusion pressure (33%) were seen, while the intrapulmonary shunt fraction was unaffected by norepinehrine. Plasma volume decreased by 6.5% and 9.4% (P<0.0001) when blood pressure was increased from 60 to 75 and 90 mmHg, respectively. MAP (P<0.02) independently predicted the decrease in plasma volume with norepinephrine but not CVP (P=0.19), cardiac index (P=0.73), norepinephrine dose (P=0.58) or urine flow (P=0.64). Conclusions: Norepinephrine causes a pressure-dependent decrease in the plasma volume in patients with vasodilatory shock most likely caused by transcapillary fluid extravasation. [source] Geostatistical analysis of ground-survey elevation data to elucidate spatial and temporal river channel changeEARTH SURFACE PROCESSES AND LANDFORMS, Issue 4 2003Adrian Chappell Abstract A digital elevation model (DEM) of a fluvial environment represented landform surface variability well and provided a medium for monitoring morphological change over time. Elevation was measured above an arbitrary datum using a ground-based three-dimensional tacheometric survey in two reaches of the River Nent, UK, in July 1998, October 1998 (after flood conditions) and June 1999. A detailed geostatistical analysis of the elevation data was used to model the spatial variation of elevation and to produce DEMs in each reach and for each survey period. Maps of the difference in elevation were produced and volumetric change was calculated for each reach and each survey period. The parameters of variogram models were used to describe the morphological character of each reach and to elucidate the linkages between process and the form of channel change operating at different spatial and temporal scales. The analysis of channel change on the River Nent shows the potential of geostatistics for investigating the magnitude and frequency of geomorphic work in other rivers. A flood modified the channel features, but low magnitude and high frequency flows rationalized the morphology. In spite of relatively small amounts of net flux the channel features changed as a consequence of the reworking of existing material. The blocking of chute entrances and redirection of the channel had a considerable effect on the behaviour of the channel. Such small changes suggested that the distributary system was sensitive to variation in sediment regime. Plots of the kriging variances against sampling intervals were used to quantify the temporal variation in sampling redundancy (ranging between ,11 per cent and +93 per cent). These curves illustrated the importance of bespoke sampling designs to reduce sampling effort by incorporating anisotropic variation in space and geomorphic information on flow regime. Variation in the nugget parameter of the variogram models was interpreted as sampling inaccuracy caused by variability in particle size and is believed to be important for future work on surface roughness. Copyright © 2003 John Wiley & Sons, Ltd. [source] Analyzing the Relationship Between Smoking and Coronary Heart Disease at the Small Area Level: A Bayesian Approach to Spatial ModelingGEOGRAPHICAL ANALYSIS, Issue 2 2006Jane Law We model the relationship between coronary heart disease and smoking prevalence and deprivation at the small area level using the Poisson log-linear model with and without random effects. Extra-Poisson variability (overdispersion) is handled through the addition of spatially structured and unstructured random effects in a Bayesian framework. In addition, four different measures of smoking prevalence are assessed because the smoking data are obtained from a survey that resulted in quite large differences in the size of the sample across the census tracts. Two of the methods use Bayes adjustments of standardized smoking ratios (local and global adjustments), and one uses a nonparametric spatial averaging technique. A preferred model is identified based on the deviance information criterion. Both smoking and deprivation are found to be statistically significant risk factors, but the effect of the smoking variable is reduced once the confounding effects of deprivation are taken into account. Maps of the spatial variability in relative risk, and the importance of the underlying covariates and random effects terms, are produced. We also identify areas with excess relative risk. [source] Controls on runoff from a partially harvested aspen-forested headwater catchment, Boreal Plain, CanadaHYDROLOGICAL PROCESSES, Issue 1 2005K. J. Devito Abstract The water balance and runoff regime of a 55 ha aspen-forested headwater catchment located on the Boreal Plain, Alberta, Canada (55·1°N, 113·8°W) were determined for 5 years following a partial timber harvest. Variability in precipitation provided the opportunity to contrast catchment water balances in relatively dry (<350 mm year,1), wet (>500 mm year,1), and average precipitation years. In most years, the catchment water balance was dominated by soil water storage, evapotranspiration losses, and vertical recharge. In 1997, despite near-average annual precipitation (486 mm), there was significant runoff (250 mm year,1) with a runoff coefficient of 52%. A wet summer and autumn in the preceding year (1996) and large snow accumulation in the spring (1997) reduced the soil water storage potential, and large runoff occurred in response to a substantial July rainfall event. Maps of the surface saturated areas indicated that runoff was generated from the uplands, ephemeral draws, and valley-bottom wetlands. Following 1997, evapotranspiration exceeded precipitation and large soil water storage potentials developed, resulting in a reduction in surface runoff to 11 mm in 1998, and <2 mm in 1999,2001. During this time, the uplands were hydrologically disconnected from ephemeral draws and valley-bottom wetlands. Interannual variability was influenced by the degree of saturation and connectivity of ephemeral draws and valley wetlands. Variability in runoff from tributaries within the catchment was influenced by the soil water storage capacity as defined by the depth to the confining layer. An analysis of the regional water balance over the past 30 years indicated that the potential to exceed upland soil water storage capacity, to connect uplands to low-lying areas, and to generate significant runoff may only occur about once every 20 years. The spatial and temporal variability of soil water storage capacity in relation to evaporation and precipitation deficits complicates interpretation of forest harvesting studies, and low runoff responses may mask the impacts of harvesting of aspen headwater areas on surface runoff in subhumid climates of the Boreal Plain. Copyright © 2005 John Wiley & Sons, Ltd. [source] Exposing the ,Second Text' of Maps of the NetJOURNAL OF COMPUTER-MEDIATED COMMUNICATION, Issue 4 2000Martin Dodge Maps have long been recognized as important and powerful modes of visual communication. In this paper we examine critically maps which are being produced to represent and promote information and communication technologies and the use of cyberspace. Drawing on the approach of map deconstruction we attempt to read and expose the ,second text' of maps of the Net. As such, we examine in detail a number of maps that display, with varying degrees of subtlety, the ideological agendas of cyberboosterism and techno-utopianism of their creators. A critical reading of these maps is important because they are widely reproduced and consumed on the Internet, in business and governmental reports, and in the popular press, all too often without a detailed consideration of the deliberate and intended messages being communicated. As we illustrate, many of these maps not only promote certain ideological messages but are often also poor in terms of cartographic design, with many containing serious ecological fallacies. We restrict our analyses to maps at the global scale. [source] Gagea tisoniana, a new species of Gagea Salisb. sect.BOTANICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 3 2007Gagea (Liliaceae) from central Italy Gagea tisoniana Peruzzi et al.sp. nov. is described and its taxonomic relationship is discussed. The new species, which appears to be endemic to central Italy, is close to G. pratensis (Pers.) Dumort., G. pusilla (F. W. Schmidt) Sweet, and other mainly poorly known [i.e. G. succedanea Griseb. et Schenk, G. transversalis Stev., and G. paczoskii (Zapal.) Grossh.] or as yet undescribed taxa from eastern Europe and the eastern Mediterranean area. The recognition of the new taxon G. tisoniana is claimed on the basis of anatomical, karyological, ecological, and phytogeographical data. Maps of the Italian distribution of G. pratensis (2n = 60), G. pusilla (2n = 24), and G. tisoniana (2n = 24) are presented, together with an analytical identification key. Finally, G. pratensis is recorded here for the first time in Tuscany (Monte Cetona). © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society, 2007, 155, 337,347. [source] Visualization of the distant dipolar field: A numerical studyCONCEPTS IN MAGNETIC RESONANCE, Issue 6 2009Stefan Kirsch Abstract The magnetization of liquid water in an external field generates an intrinsic magnetic field in the sample called the distant dipolar field (DDF). To visualize the spatial distribution of the DDF a numerical study was performed for the case of liquid,state 1H NMR at 7 T. 2D maps of the frequency offset caused by the DDF in pure water were calculated for homogenously magnetized spherical and cylindrical samples as well as for the case of a spatially modulated magnetization distribution occurring e.g., in CRAZED (Cosy Revamped by Asymmetric Z-Gradient Echo Detection) experiments. The calculation yielded DDF induced frequency offsets in the range of 0.58 Hz to 10.24 Hz inside the homogeneously magnetized cylinders, while DDF-induced frequency offsets ,10,5 Hz were obtained inside the sphere. The calculated frequency offsets were in good agreement with analytical results available for a sphere and an infinitely long cylinder. In the case of a spatially modulated magnetization distribution, DDF-induced frequency offsets with maximum values of +0.83 Hz were obtained inside the sphere. The presented 2D maps of the DDF-induced frequency offset have tutorial character and may help to visualize this phenomenon in a direct manner. © 2009 Wiley Periodicals, Inc. Concepts Magn Reson Part A 34A:357,364, 2009. [source] Forks in the Road: Choices in Procedures for Designing Wildland LinkagesCONSERVATION BIOLOGY, Issue 4 2008PAUL BEIER análisis de sensibilidad; conectividad; corredor de vida silvestre; enlace; diseño de reservas Abstract:,Models are commonly used to identify lands that will best maintain the ability of wildlife to move between wildland blocks through matrix lands after the remaining matrix has become incompatible with wildlife movement. We offer a roadmap of 16 choices and assumptions that arise in designing linkages to facilitate movement or gene flow of focal species between 2 or more predefined wildland blocks. We recommend designing linkages to serve multiple (rather than one) focal species likely to serve as a collective umbrella for all native species and ecological processes, explicitly acknowledging untested assumptions, and using uncertainty analysis to illustrate potential effects of model uncertainty. Such uncertainty is best displayed to stakeholders as maps of modeled linkages under different assumptions. We also recommend modeling corridor dwellers (species that require more than one generation to move their genes between wildland blocks) differently from passage species (for which an individual can move between wildland blocks within a few weeks). We identify a problem, which we call the subjective translation problem, that arises because the analyst must subjectively decide how to translate measurements of resource selection into resistance. This problem can be overcome by estimating resistance from observations of animal movement, genetic distances, or interpatch movements. There is room for substantial improvement in the procedures used to design linkages robust to climate change and in tools that allow stakeholders to compare an optimal linkage design to alternative designs that minimize costs or achieve other conservation goals. Resumen:,Los modelos son utilizados comúnmente para identificar tierras que mantengan la habilidad de la vida silvestre para moverse entre bloques de tierras silvestres a través de una matriz de tierras que habían sido incompatibles con el movimiento de vida silvestre. Ofrecemos 16 opciones y supuestos que se originan en el diseño de enlaces para facilitar el movimiento o el flujo de genes de especies focales entre 2 o más bloques de tierras silvestres predefinidos. Recomendamos el diseño de enlaces que sirvan a múltiples (y solo a una) especies focales que funjan como una sombrilla colectiva para todas las especies nativas y los procesos ecológicos, que explícitamente admitan supuestos no comprobados y que utilicen análisis de incertidumbre para ilustrar efectos potenciales de la incertidumbre del modelo. La mejor forma de mostrar tal incertidumbre a los interesados es mediante mapas de los enlaces modelados bajo diferentes suposiciones. También recomendamos modelar a habitantes de corredores (especies que requieren más de una generación para mover sus genes entre bloques de tierra silvestre) de manera diferente que las especies pasajeras (un individuo se puede mover entre bloques de tierras silvestres en unas cuantas semanas). Identificamos un problema, que denominamos el problema de traducción subjetiva, que surge porque un analista debe decidir subjetivamente cómo traducir medidas de selección de recursos a resistencia. Este problema puede ser sobrepuesto mediante la estimación de la resistencia a partir de observaciones de movimientos de animales, distancias genéticas o movimientos entre fragmentos. Hay espacio para la mejora sustancial de los procedimientos utilizados para diseñar enlaces robustos ante el cambio climático y en herramientas que permiten que los interesados comparen un diseño óptimo con diseños alternativos que minimicen costos o alcancen otras metas de conservación. [source] Spatial Tests of the Pesticide Drift, Habitat Destruction, UV-B, and Climate-Change Hypotheses for California Amphibian DeclinesCONSERVATION BIOLOGY, Issue 6 2002Carlos Davidson In California, the transport and deposition of pesticides from the agriculturally intensive Central Valley to the adjacent Sierra Nevada is well documented, and pesticides have been found in the bodies of Sierra frogs. Pesticides are therefore a plausible cause of declines, but to date no direct links have been found between pesticides and actual amphibian population declines. Using a geographic information system, we constructed maps of the spatial pattern of declines for eight declining California amphibian taxa, and compared the observed patterns of decline to those predicted by hypotheses of wind-borne pesticides, habitat destruction, ultraviolet radiation, and climate change. In four species, we found a strong positive association between declines and the amount of upwind agricultural land use, suggesting that wind-borne pesticides may be an important factor in declines. For two other species, declines were strongly associated with local urban and agricultural land use, consistent with the habitat-destruction hypothesis. The patterns of decline were not consistent with either the ultraviolet radiation or climate-change hypotheses for any of the species we examined. Resumen: Por mucho tiempo se ha sugerido que los pesticidas transportados por el viento son una causa de la declinación de anfibios en áreas sin destrucción de hábitat evidente. En California, el transporte y depósito de pesticidas provenientes del Valle Central, donde se practica la agricultura intensiva, hacia la Sierra Nevada adyacente está bien documentado y se han encontrado pesticidas en el cuerpo de ranas de la Sierra. Por lo tanto, los pesticidas son una causa verosímil de las declinaciones, pero a la fecha no se han encontrado relaciones directas entre los pesticidas y la declinación de anfibios. Construimos mapas de sistemas de información geográfica del patrón espacial de las declinaciones de ocho taxones de anfibios de California, y comparamos los patrones de declinación observados con los esperados por las hipótesis de pesticidas transportados por el viento, la destrucción del hábitat, la radiación ultravioleta y el cambio climático. En cuatro especies, encontramos una fuerte asociación positiva entre las declinaciones y la cantidad de tierras de uso agrícola en dirección contraria a los vientos, lo que sugiere que los pesticidas transportados por el viento pueden ser un factor importante en las declinaciones. Para otras dos especies, las declinaciones se asociaron contundentemente con el uso del suelo urbano y agrícola, lo cual es consistente con la hipótesis de la destrucción del hábitat. Los patrones de declinación no fueron consistentes con la hipótesis de la radiación ultravioleta ni la de cambio climático para ninguna de las especies examinadas. [source] Tracking Fragmentation of Natural Communities and Changes in Land Cover: Applications of Landsat Data for Conservation in an Urban Landscape (Chicago Wilderness)CONSERVATION BIOLOGY, Issue 4 2001Yeqiao Wang Within the metropolis survive some of the world's best remaining examples of eastern tallgrass prairie, oak savanna, open oak woodland, and prairie wetland. Chicago Wilderness is more than 81,000 ha of protected areas in the urban and suburban matrix. It also is the name of the coalition of more than 110 organizations committed to the survival of these natural lands. The long-term health of these imperiled communities depends on proper management of the more extensive, restorable lands that surround and connect the patches of high-quality habitat. Information critical to the success of conservation efforts in the region includes (1) a current vegetation map of Chicago Wilderness in sufficient detail to allow quantitative goal setting for the region's biodiversity recovery plan; (2) quantified fragmentation status of the natural communities; and (3) patterns of land-cover change and their effects on the vitality of communities under threat. We used multispectral data from the Landsat thematic mapper (October 1997) and associated ground truthing to produce a current vegetation map. With multitemporal remote-sensing data (acquired in 1972, 1985, and 1997), we derived land-cover maps of the region at roughly equivalent intervals over the past 25 years. Analyses with geographic information system models reveal rapid acceleration of urban and suburban sprawl over the past 12 years. Satellite images provide striking visual comparisons of land use and health. They also provide banks of geographically referenced data that make quantitative tracking of trends possible. The data on habitat degradation and fragmentation are the biological foundation of quantitative goals for regional restoration. Resumen: En Chicago hay una concentración de comunidades naturales globalmente significativas sorprendentemente alta. En la metrópolis sobreviven algunos de los mejores ejemplos mundiales remanentes de praderas de pastos orientales, sabanas de roble, bosques abiertos de roble y humedales de pradera. Chicago Wilderness es más de 81,000 ha de áreas protegidas en la matriz urbana y suburbana. También es el nombre de una coalición de más de 110 organizaciones dedicadas a la supervivencia de esas tierras naturales. La salud a largo plazo de estas comunidades amenazadas depende del manejo adecuado de las tierras, más extensas y restaurables, que rodean y conectan a los fragmentos de hábitat de alta calidad. La información crítica para el éxito de los esfuerzos de conservación en la región incluye: (1) un mapa actualizado de la vegetación de Chicago Wilderness con suficiente detalle para que la definición de metas cuantitativas para el plan de recuperación de la región sea posible; (2) cuantificación de la fragmentación de las comunidades naturales y (3) patrones de cambio de cobertura de suelo y sus efectos sobre la vitalidad de las comunidades amenazadas. Utilizamos datos multiespectrales del mapeador temático Landsat (octubre 1997) y verificaciones de campo asociadas para producir el mapa actualizado de vegetación. Con datos de percepción remota multitemporales (obtenidos en 1972, 1985 y 1997), derivamos los mapas de cobertura de suelo en la región en intervalos equivalentes en los últimos 25 años. El análisis de los modelos SIG revela una rápida aceleramiento del crecimiento urbano y suburbano en los últimos 12 años. Las imágenes de satélite proporcionan comparaciones visuales notables del uso y condición del suelo. También proporcionan bancos de datos referenciados geográficamente que hacen posible el rastreo de tendencias cuantitativas. Los datos de degradación y fragmentación del hábitat son la base biológica de metas cuantitativas para la restauración regional. [source] A TAXONOMIC REVISION OF BIARUMCURTIS'S BOTANICAL MAGAZINE, Issue 1 2008Araceae Summary This paper contains a revision of the genus Biarum Schott. 21 species and 6 subspecies are recognised. All the taxa (except B. mendax Boyce) are illustrated by line drawings, and most of them are shown as paintings or as photographs in habitat or in cultivation. Distribution maps of all the species are given and a key to all taxa is provided. [source] Range size, taxon age and hotspots of neoendemism in the California floraDIVERSITY AND DISTRIBUTIONS, Issue 3 2010Nathan J. B. Kraft Abstract Aim, Sustaining biological diversity requires the protection of the ecological, evolutionary and landscape-level processes that generate it. Here, we identify areas of high neoendemism in a global diversity hotspot, the California flora, using range size data and molecular-based estimates of taxon age. Location, California, USA. Methods, We compiled distribution and range size data for all plant taxa endemic to California and internal transcribed spacer (ITS)-based age estimates for 337 putative neoendemics (15% of the endemic flora). This information was combined to identify areas in the state with high proportions of young and restricted-range taxa. We overlaid the distribution of neoendemic hotspots on maps of currently protected lands and also explored correlations between our diversity measures and climate. Results, The central coast of California, the Sierra Nevada and the San Bernardino Range contained endemics with the most restricted distributions on average, while areas in the Desert and Great Basin provinces found within the state were composed of the youngest neoendemics on average. Diversity measures that took age and range size into account shifted the estimate of highest endemic diversity in the state towards the Desert and Great Basin regions relative to simple counts of endemic species richness. Our diversity measures were poorly correlated with climate and topographic heterogeneity. Main conclusions, Substantial portions of California with high levels of plant neoendemism fall outside of protected lands, indicating that additional action will be needed to preserve the geographic areas apparently associated with high rates of plant diversification. The neoendemic flora of the deserts appears particularly young in our analyses, which may reflect the relatively recent origin of desert environments within the state. [source] High resolution quantification of gully erosion in upland peatlands at the landscape scaleEARTH SURFACE PROCESSES AND LANDFORMS, Issue 8 2010Martin Evans Abstract The upland peatlands of the UK are severely eroded, with large areas affected by gully erosion. The peatlands are important areas of carbon storage and provide a range of other ecosystem services including water supply and biodiversity all of which are negatively impacted by erosion of the upland surface. The magnitude of the gully erosion, and consequent adjustment of the peatland morphology, is such that in degraded peatlands the extent and magnitude of erosion is a major control on peatland function. Accurate mapping of gully form is therefore a necessary precondition to the understanding and management of these systems. This paper develops an approach to extracting gully maps from high resolution digital elevation models (DEMs). Gully maps of the Bleaklow Plateau in northern England were derived from a 2,m LiDAR DEM by combining areas of low difference from mean elevation and high positive plan curvature. Gully depth was modelled by interpolating between gully edges. Testing of the gully mapping and depth modelling against aerial photography, manual interpretation of the DEM and ground survey revealed that gully plan form is well represented and gully width and depth are modelled with tolerances close to the horizontal and vertical resolution of the LiDAR imagery. Estimates of gully width and depth were less reliable for gullies with total width of less than four pixels. The approach allows for the first time the derivation of accurate estimates of gully extent and magnitude over large areas and provides the basis for modelling a range of processes controlled by gullying. The approach has wider applicability to mapping gully erosion in a wide range of environments. Copyright © 2010 John Wiley & Sons, Ltd. [source] Measurement of the spatial distribution of fluvial bedload transport velocity in both sand and gravelEARTH SURFACE PROCESSES AND LANDFORMS, Issue 10 2004Colin D. Rennie Abstract Maps are presented of the spatial distribution of two-dimensional bedload transport velocity vectors. Bedload velocity data were collected using the bottom tracking feature of an acoustic Doppler current pro,ler (aDcp) in both a gravel-bed reach and a sand-bed reach of Fraser River, British Columbia. Block-averaged bedload velocity vectors, and bedload velocity vectors interpolated onto a uniform grid, revealed coherent patterns in the bedload velocity distribution. Concurrent Helley-Smith bedload sampling in the sand-bed reach corroborated the trends observed in the bedload velocity map. Contemporaneous 2D vector maps of near-bed water velocity (velocity in bins centered between 25 cm and 50 cm from the bottom) and depth-averaged water velocity were also generated from the aDcp data. Using a vector correlation coef,cient, which is independent of the choice of coordinate system, the bedload velocity distribution was signi,cantly correlated to the near-bed and depth-averaged water velocity distributions. The bedload velocity distribution also compared favorably with variations in depth and estimates of the spatial distribution of shear stress. Published in 2004 by John Wiley & Sons, Ltd. [source] Effects of landscape composition and substrate availability on saproxylic beetles in boreal forests: a study using experimental logs for monitoring assemblagesECOGRAPHY, Issue 2 2006Heloise Gibb Intensive forestry practises in the Swedish landscape have led to the loss and fragmentation of stable old-growth habitats. We investigated relationships between landscape composition at multiple scales and the composition of saproxylic beetle assemblages in nine clear-cut, mature managed and old-growth spruce-dominated forest stands in the central boreal zone of Sweden. We set out fresh spruce and birch logs and created spruce snags in 2001,2002 to experimentally test the effects of coarse woody debris (CWD) type and forest management on the composition of early and late successional, and red-listed saproxylic beetle assemblages. We examined effects of CWD availability at 100 m, and landscape composition at 1 and 10 km on saproxylic beetle abundances. Additionally, we tested whether assemblage similarity decreased with increasing distance between sites. We collected beetles from the experimental logs using eclector and window traps in four periods during 2003. CWD was measured and landscape composition data was obtained from maps of remotely sensed data. The composition of saproxylic beetles differed among different CWD substrates and between clear-cuts and the older stand types, however differences between mature managed and old-growth forests were significant only for red-listed species. Assemblage similarities for red-listed species on clear-cuts were more different at greater distances apart, indicating that they have more localised distributions. CWD availability within 100 m of the study sites was rarely important in determining the abundance of species, suggesting that early successional saproxylic beetles can disperse further than this distance. At a larger scale, a large area of suitable stand types within both 1 and 10 km resulted in greater abundances in the study sites for several common and habitat-specific species. The availability of suitable habitat at scales of 1,10 km is thus likely to be important in the survival of many saproxylic species in forestry-fragmented areas. [source] Spatial analysis of an invasion front of Acer platanoides: dynamic inferences from static dataECOGRAPHY, Issue 3 2005Wei Fang It is an open question whether the invading tree species Acer platanoides is invading and displacing native trees within pre-existing forest stands, or merely preferentially occupying new stands of secondary forest growth at the edges of existing forests. Several threads of spatial pattern analyses were used to assess the invasibility of A. platanoides, and to link the invasion to the structure of a plant community in the deciduous forest of the northeastern United States. The analyses were based on maps of a contiguous 100×50 m area along an A. platanoides infestation gradient. The distribution of A. platanoides was highly aggregated and the population importance value increased from 28.1 to 38.5% according to mortality estimated from standing dead trees, while the distribution of native tree species was close to random and importance value of Quercus spp. decreased from 33.4 to 26.9% over time. The size distributions of each tree species across distance indicated that A. platanoides was progressively invading the interior of the forest while the native species (including A. rubrum) were not spreading back towards the A. platanoides monospecific patch. The null hypothesis of no invasibility was rejected based on quantile regressions. There were negative correlations between A. platanoides density and the densities of native species in different functional groups, and negative correlation of A. platanoides density and the species diversity in forest understory. The null hypothesis that A. platanoides invasion did not suppress native trees or understory was rejected based on Dutilleul's modified t-test for correlation, consistent with experimental results in the same study site. The combination of multiple spatial analyses of static data can be used to infer historical dynamical processes that shape a plant community structure. The concept of "envelop effects" was discussed and further developed. [source] Spatial utilisation of fast-ice by Weddell seals Leptonychotes weddelli during winterECOGRAPHY, Issue 3 2005Samantha Lake This study describes the distribution of Weddell seals Leptonychotes weddelli in winter (May,September 1999) at the Vestfold Hills, in Prydz Bay, East Antarctica. Specifically, we describe the spatial extent of haul-out sites in shore,fast sea-ice, commonly referred to as fast-ice. As winter progressed, and the fast-ice grew thick (ca 2 m), most of the inshore holes closed over, and the seals' distribution became restricted to ocean areas beyond land and islands. Using observations from the end of winter only, we fitted Generalised Additive Models (GAMs) to generate resource selection functions, which are models that yield values proportional to the probability of use. The models showed that seal distribution was defined mainly by distance to ice-edge and distance to land. Distance to ice-bergs was also selected for models of some regions. We present the results as maps of the fitted probability of seal presence, predicted by the binomial GAM for offshore regions, both with and without autocorrelation terms. The maps illustrate the expected distribution encompassing most of the observed distribution. On this basis, we hypothesise that propensity for the fast-ice to crack is the major determinant of Weddell seal distribution in winter. Proximity to open water and pack-ice habitats could also influence the distribution of haul-out sites in fast-ice areas. This is the first quantitative study of Weddell seal distribution in winter. Potential for regional variation is discussed. [source] Space,time zero-inflated count models of Harbor seals,ENVIRONMETRICS, Issue 7 2007Jay M. Ver Hoef Abstract Environmental data are spatial, temporal, and often come with many zeros. In this paper, we included space-time random effects in zero-inflated Poisson (ZIP) and ,hurdle' models to investigate haulout patterns of harbor seals on glacial ice. The data consisted of counts, for 18 dates on a lattice grid of samples, of harbor seals hauled out on glacial ice in Disenchantment Bay, near Yakutat, Alaska. A hurdle model is similar to a ZIP model except it does not mix zeros from the binary and count processes. Both models can be used for zero-inflated data, and we compared space-time ZIP and hurdle models in a Bayesian hierarchical model. Space-time ZIP and hurdle models were constructed by using spatial conditional autoregressive (CAR) models and temporal first-order autoregressive (AR(1)) models as random effects in ZIP and hurdle regression models. We created maps of smoothed predictions for harbor seal counts based on ice density, other covariates, and spatio-temporal random effects. For both models predictions around the edges appeared to be positively biased. The linex loss function is an asymmetric loss function that penalizes overprediction more than underprediction, and we used it to correct for prediction bias to get the best map for space-time ZIP and hurdle models. Published in 2007 by John Wiley & Sons, Ltd. [source] Effect of housing factors and surficial uranium on the spatial prediction of residential radon in IowaENVIRONMETRICS, Issue 5 2007Brian J. Smith Abstract Growing epidemiologic evidence suggests that residential radon is an important risk factor for lung cancer. Consequently, public health professionals have expressed interest in characterizing the spatial distribution of radon concentrations in order to identify geographic regions of high exposure. Ambient radon concentrations are a function of geologic features including soil radium content. Indoor radon concentrations can vary based on building characteristics that affect the entry of radon into the building and movement between rooms therein. We present a geostatistical hierarchical Bayesian model for radon that allows for spatial prediction based on geologic data and housing characteristics. Our model is applied to radon data from an epidemiologic study in Iowa that consist of 136 outdoor measurements and 2590 indoor measurements from 614 residential homes. Housing characteristics collected in the Iowa Study are included as predictors in the model. Geologic data in the form of county-average surficial uranium concentrations from the USGS National Uranium Resource Evaluation project are also considered. A ,change of support' approach is implemented to combine the radon measurements, collected at points in space, and the uranium concentrations, averaged over counties, so that point-source concentrations for the latter are available for the analysis. Estimates of the effect of select housing factors on radon are provided along with spatial maps of predicted radon concentrations in Iowa. Copyright © 2006 John Wiley & Sons, Ltd. [source] Substantial Thalamostriatal Dopaminergic Defect in Unverricht-Lundborg DiseaseEPILEPSIA, Issue 9 2007Miikka Korja Summary:,Purpose: Unverricht-Lundborg disease (ULD) is currently classified as progressive myoclonus epilepsy. Myoclonus, the characteristic symptom in ULD, suggests that dopamine neurotransmission may be involved in the pathophysiology of ULD. Our purpose was to examine brain dopaminergic function in ULD patients. Methods: Four genetically and clinically diagnosed ULD patients and eight healthy controls were scanned with [11C]raclopride-PET. PET images were coregistered to individual 1.5T MR images and region-of-interest analysis was performed for the striatum and thalamus. Standardized uptake values and individual voxel-wise binding potential maps of the patients and controls were also analyzed. Results: ULD patients had markedly higher (31,54%) dopamine D2-like receptor availabilities than healthy controls in both the striatum and the thalamus. The proportionally highest binding potentials were detected in the thalamus. There were no significant differences in the cerebellar uptake of [11C]raclopride in ULD patients versus healthy controls. Voxel-based results were in accordance with the region-of-interest analysis. Conclusions: These results suggest that dopaminergic modulation at the level of the striatum and thalamus could be a crucial factor contributing to the symptoms of ULD. In the light of our data, we propose that ULD with dopamine dysfunction and dyskinetic symptoms shares certain pathophysiological mechanisms with classical movement disorders. Future studies are therefore warranted to study the effect of dopaminergic pharmacotherapy in ULD. [source] Equine clinical genomics: A clinician's primerEQUINE VETERINARY JOURNAL, Issue 7 2010M. M. BROSNAHAN Summary The objective of this review is to introduce equine clinicians to the rapidly evolving field of clinical genomics with a vision of improving the health and welfare of the domestic horse. For 15 years a consortium of veterinary geneticists and clinicians has worked together under the umbrella of The Horse Genome Project. This group, encompassing 22 laboratories in 12 countries, has made rapid progress, developing several iterations of linkage, physical and comparative gene maps of the horse with increasing levels of detail. In early 2006, the research was greatly facilitated when the US National Human Genome Research Institute of the National Institutes of Health added the horse to the list of mammalian species scheduled for whole genome sequencing. The genome of the domestic horse has now been sequenced and is available to researchers worldwide in publicly accessible databases. This achievement creates the potential for transformative change within the horse industry, particularly in the fields of internal medicine, sports medicine and reproduction. The genome sequence has enabled the development of new genome-wide tools and resources for studying inherited diseases of the horse. To date, researchers have identified 11 mutations causing 10 clinical syndromes in the horse. Testing is commercially available for all but one of these diseases. Future research will probably identify the genetic bases for other equine diseases, produce new diagnostic tests and generate novel therapeutics for some of these conditions. This will enable equine clinicians to play a critical role in ensuring the thoughtful and appropriate application of this knowledge as they assist clients with breeding and clinical decision-making. [source] Mapping responses to frequency sweeps and tones in the inferior colliculus of house miceEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 8 2003Steffen R. Hage Abstract In auditory maps of the primary auditory cortex, neural response properties are arranged in a systematic way over the cortical surface. As in the visual system, such maps may play a critical role in the representation of sounds for perception and cognition. By recording from single neurons in the central nucleus of the inferior colliculus (ICC) of the mouse, we present the first evidence for spatial organizations of parameters of frequency sweeps (sweep speed, upward/downward sweep direction) and of whole-field tone response patterns together with a map of frequency tuning curve shape. The maps of sweep speed, tone response patterns and tuning curve shape are concentrically arranged on frequency band laminae of the ICC with the representation of slow speeds, build up response types and sharp tuning mainly in the centre of a lamina, and all (including high) speeds, phasic response types and broad tuning mainly in the periphery. Representation of sweep direction shows preferences for upward sweeps medially and laterally and downward sweeps mainly centrally in the ICC (either striped or concentric map). These maps are compatible with the idea of a gradient of decreasing inhibition from the centre to the periphery of the ICC and by gradients of intrinsic neuronal properties (onset or sustained responding). The maps in the inferior colliculus compare favourably with corresponding maps in the primary auditory cortex, and we show how the maps of sweep speed and direction selectivity of the primary auditory cortex could be derived from the here-found maps of the inferior colliculus. [source] Molecular-feature domains with posterodorsal,anteroventral polarity in the symmetrical sensory maps of the mouse olfactory bulb: mapping of odourant-induced Zif268 expressionEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 10 2002Koichiro Inaki Abstract Individual glomeruli in the mammalian olfactory bulb presumably represent a single type of odourant receptor. Thus, the glomerular sheet provides odourant receptor maps at the surface of the olfactory bulb. To understand the basic spatial organization of the olfactory sensory maps, we first compared the spatial distribution of odourant-induced responses measured by the optical imaging of intrinsic signals with that detected immunohistochemically by expressions of Zif268, one of the immediate early gene products in juxtaglomerular cells. In the dorsal surface of the bulb, we detected a clear correlation in the spatial pattern between these responses. In addition, the molecular-feature domains and their polarities (spatial shifts of responses with an increase in carbon chain length) that were defined by the optical imaging method could be also detected by the Zif268 mapping method. We then mapped the Zif268 signals over the entire olfactory bulb using a homologous series of fatty acids and aliphatic alcohols as stimulus odourants. We superimposed the Zif268 signals onto the standard unrolled map with the help of cell adhesion molecule compartments. Each odourant typically elicited two pairs of clusters of dense Zif268 signals. The results showed that molecular-feature domains and their polarities were arranged symmetrically at stereotypical positions in a mirror-image fashion between the lateral and the medial sensory maps. The polarity of each domain was roughly in parallel with the posterodorsal,anteroventral axis that was defined by the cell adhesion molecule compartments. These results suggest that the molecular-feature domain with its fixed polarity is one of the basic structural units in the spatial organization of the odourant receptor maps in the olfactory bulb. [source] Functional topography of the human nonREM sleep electroencephalogramEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 12 2001Luca A. Finelli Abstract The sleep EEG of healthy young men was recorded during baseline and recovery sleep after 40 h of waking. To analyse the EEG topography, power spectra were computed from 27 derivations. Mean power maps of the nonREM sleep EEG were calculated for 1-Hz bins between 1.0 and 24.75 Hz. Cluster analysis revealed a topographic segregation into distinct frequency bands which were similar for baseline and recovery sleep, and corresponded closely to the traditional frequency bands. Hallmarks of the power maps were the frontal predominance in the delta and alpha band, the occipital predominance in the theta band, and the sharply delineated vertex maximum in the sigma band. The effect of sleep deprivation on EEG topography was determined by calculating the recovery/baseline ratio of the power spectra. Prolonged waking induced an increase in power in the low-frequency range (1,10.75 Hz) which was largest over the frontal region, and a decrease in power in the sigma band (13,15.75 Hz) which was most pronounced over the vertex. The topographic pattern of the recovery/baseline power ratio was similar to the power ratio between the first and second half of the baseline night. These results indicate that changes in sleep propensity are reflected by specific regional differences in EEG power. The predominant increase of low-frequency power in frontal areas may be due to a high ,recovery need' of the frontal heteromodal association areas of the cortex. [source] Analysing soil variation in two dimensions with the discrete wavelet transformEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 4 2004R. M. Lark Summary Complex spatial variation in soil can be analysed by wavelets into contributions at several scales or resolutions. The first applications were to data recorded at regular intervals in one dimension, i.e. on transects. The theory extends readily to two dimensions, but the application to small sets of gridded data such as one is likely to have from a soil survey requires special adaptation. This paper describes the extension of wavelet theory to two dimensions. The adaptation of the wavelet filters near the limits of a region that was successful in one dimension proved unsuitable in two dimensions. We therefore had to pad the data out symmetrically beyond the limits to minimize edge effects. With the above modifications and Daubechies's wavelet with two vanishing moments the analysis is applied to soil thickness, slope gradient, and direct solar beam radiation at the land surface recorded at 100-m intervals on a 60 × 101 square grid in south-west England. The analysis revealed contributions to the variance at several scales and for different directions and correlations between the variables that were not evident in maps of the original data. In particular, it showed how the thickness of the soil increasingly matches the geological structure with increasing dilation of the wavelet, this relationship being local to the strongly aligned outcrops. The analysis reveals a similar pattern in slope gradient, and a negative correlation with soil thickness, most clearly evident at the coarser scales. The solar beam radiation integrates slope gradient and azimuth, and the analysis emphasizes the relations with topography at the various spatial scales and reveals additional effects of aspect on soil thickness. [source] THE RATE OF GENOME STABILIZATION IN HOMOPLOID HYBRID SPECIESEVOLUTION, Issue 2 2008C. Alex Buerkle Homoploid hybrid speciation has been recognized for its potential rapid completion, an idea that has received support from experimental and modeling studies. Following initial hybridization, the genomes of parental species recombine and junctions between chromosomal blocks of different parental origin leave a record of recombination and the time period before homogenization of the derived genome. We use detailed genetic maps of three hybrid species of sunflowers and models to estimate the time required for the stabilization of the new hybrid genome. In contrast to previous estimates of 60 or fewer generations, we find that the genomes of three hybrid sunflower species were not stabilized for hundreds of generations. These results are reconciled with previous research by recognizing that the stabilization of a hybrid species' genome is not synonymous with hybrid speciation. Segregating factors that contribute to initial ecological or intrinsic genetic isolation may become stabilized quickly. The remainder of the genome likely becomes stabilized over a longer time interval, with recombination and drift dictating the contributions of the parental genomes. Our modeling of genome stabilization provides an upper bound for the time interval for reproductive isolation to be established and confirms the rapid nature of homoploid hybrid speciation. [source] Characterization of a eukaryotic type serine/threonine protein kinase and protein phosphatase of Streptococcus pneumoniae and identification of kinase substratesFEBS JOURNAL, Issue 5 2005Linda Nováková Searching the genome sequence of Streptococcus pneumoniae revealed the presence of a single Ser/Thr protein kinase gene stkP linked to protein phosphatase phpP. Biochemical studies performed with recombinant StkP suggest that this protein is a functional eukaryotic-type Ser/Thr protein kinase. In vitro kinase assays and Western blots of S. pneumoniae subcellular fractions revealed that StkP is a membrane protein. PhpP is a soluble protein with manganese-dependent phosphatase activity in vitro against a synthetic substrate RRA(pT)VA. Mutations in the invariant aspartate residues implicated in the metal binding completely abolished PhpP activity. Autophosphorylated form of StkP was shown to be a substrate for PhpP. These results suggest that StkP and PhpP could operate as a functional pair in vivo. Analysis of phosphoproteome maps of both wild-type and stkP null mutant strains labeled in vivo and subsequent phosphoprotein identification by peptide mass fingerprinting revealed two possible substrates for StkP. The evidence is presented that StkP can phosphorylate in vitro phosphoglucosamine mutase GlmM which catalyzes the first step in the biosynthetic pathway leading to the formation of UDP- N -acetylglucosamine, an essential common precursor to cell envelope components. [source] Complete physical map and gene content of the human NF1 tumor suppressor region in human and mouseGENES, CHROMOSOMES AND CANCER, Issue 2 2003Dieter E. Jenne Duplicon-mediated microdeletions around the NF1 gene are frequently associated with a severe form of neurofibromatosis type I in a subgroup of patients who show an earlier onset of cutaneous neurofibromas, dysmorphic facial features, and lower IQ values. To clarify the discrepancies between published maps of the NF1 tumor-suppressor gene region as well as the length of gaps in these assemblies and to validate the recently described tandem duplication of the human NF1 locus, we assembled a contiguous high-density map of BAC and PAC clones from different genomic libraries. Although two WI-12393,derived low-copy fragments are known to occur at the proximal and distal boundaries of the 1.5-Mb segment that is usually deleted in NF1 microdeletion patients, we identified an additional WI-12393,related segment between the MGC13061 and the NF1 gene, which appears to trigger interstitial deletions of smaller size as observed in two patients. Moreover, we completed the genomic organization and cDNA structure of all functional genes, CYTOR4, FLJ12735, FLJ22729, CENTA2, MGC13061, NF1, OMG, EVI2B, EVI2A, KIAA1821, MGC11316, HCA66, KIAA0160, and WI-12393, from this region. A comparison of the human map to the orthologous region on mouse chromosome 11 revealed significant differences in the number and arrangement of genes, indicating that many chromosomal breaks with partial duplications, inversions, and deletions occurred predominantly in the primate lineage. © 2003 Wiley-Liss, Inc. [source] Geostatistical and multi-elemental analysis of soils to interpret land-use history in the Hebrides, ScotlandGEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 4 2007J.A. Entwistle In the absence of documentary evidence about settlement form and agricultural practice in northwest Scotland before the mid-18th century, a geoarchaeological approach to reconstructing medieval land use and settlement form is presented here. This study applies multielemental analysis to soils previously collected from a settlement site in the Hebrides and highlights the importance of a detailed knowledge of the local soil environment and the cultural context. Geostatistical methods were used to analyze the spatial variability and distribution of a range of soil properties typically associated with geoarchaeological investigations. Semivariograms were produced to determine the spatial dependence of soil properties, and ordinary kriging was undertaken to produce prediction maps of the spatial distribution of these soil properties and enable interpolation over nonsampled locations in an attempt to more fully elucidate former land-use activity and settlement patterns. The importance of identifying the spatial covariance of elements and the need for several lines of physical and chemical evidence is highlighted. For many townships in the Hebrides, whose precise location and layout prior to extensive land reorganization in the late 18th,early 19th century is not recoverable through plans, multi-elemental analysis of soils can offer a valuable prospective and diagnostic tool. © 2007 Wiley Periodicals, Inc. [source] Geostatistical Simulation for the Assessment of Regional Soil PollutionGEOGRAPHICAL ANALYSIS, Issue 2 2010Marc Van Meirvenne Regional scale inventories of heavy metal concentrations in soil increasingly are being done to evaluate their global patterns of variation. Sometimes these global pattern evaluations reveal information that is not identified by more detailed studies. Geostatistical methods, such as stochastic simulation, have not yet been used routinely for this purpose in spite of their potential. To investigate such a use of geostatistical methods, we analyzed a data set of 14,674 copper and 12,441 cadmium observations in the topsoil of Flanders, Belgium, covering 13,522 km2. Outliers were identified and removed, and the distributions were spatially declustered. Copper was analyzed using sequential Gaussian simulation, whereas for cadmium we used sequential indicator simulation because of the large proportion (43%) of censored data. We complemented maps of the estimated values with maps of the probability of exceeding a critical sanitation threshold for agricultural land use. These sets of maps allowed the identification of regional patterns of increased metal concentrations and provided insight into their potential causes. Mostly areas with known industrial activities (such as lead and zinc smelters) could be delineated, but the effects of shells fired during the First World War were also identified. En los estudios de contaminación de suelos as escala regional, es práctica común la implementación de inventarios de concentraciones de metales pesados en el suelo con el fin de evaluar sus patrones globales de variación espacial. A veces dichas evaluaciones de patrones globales proporcionan información que no son aparentes en estudios realizados a escalas más detalladas. En este contexto, a pesar del potencial analítico que poseen, los métodos geostadísticos como la simulación estocástica han recibido poca atención. Los autores del presente artículo proponen llenar este vacío aplicando métodos geostadísticos para el análisis de dos bases de datos: 14,674 observaciones de cobre (Cu) y 12,441 observaciones de cadmio (Cd). Los datos corresponden a la capa superior de suelo en un área de 13,522 km2 en Flandes, Belgica. Tras la remoción de los valores extremos (outliers) y la desaglomeración de las distribuciones, los autores analizan los datos vía dos procedimientos: a) una Simulación Secuencial Gausiana (SGS) para los datos de cobre, y b) una Simulación Secuencial Indicador (SIS). La diferencia en el tratamiento analítico para ambos metales obedece a la considerable proporción (43%) de datos censurados de cadmio. Los mapas resultantes de valores estimados fueron complementados con mapas que ilustran la probabilidad de exceder los umbrales críticos para uso agrícola de la tierra. Esta serie de mapas permitió la identificación de patrones regionales de concentraciones crecientes de metales y proporciono claves importantes acerca de sus posibles causas. Los patrones hallados coinciden con áreas donde se realizan actividades industriales (como fundiciones de plomo y zinc), pero también con la distribución espacial de casquillos de balas disparadas durante la Primera Guerra Mundial. [source] | ||||||||||||||||||||||||||||||||||