ALBERT

Beschreibung: Land use change as conversion pasture to forest produces several changes on hydrological cycle. In this paper we analyze the effects on stream discharge of afforestation of a small watershed devoted to pasture using the HBV hydrological model. Streamflow data obtained over the first ten years after planting were employed to evaluate the capacity of HBV model to simulate hydrological behavior of catchment after afforestation. Obtained results indicate that the estimation of streamflow was accurate as reflected by statistics (R 2  = 0.90, NSC = 0.89 and PBIAS = 0.34). Afterwards, streamflow under pasture land use (if afforestation had not occurred) was simulated using hydro-meteorological data collected during the period of study and model parameters optimized previously, together with two parameters, pcorr and cevpfo , that were adjusted for pasture conditions. HBV model results indicate that afforestation produced a water yield reduction around 2000 mm (22% of total stream discharge) during the first ten years of planting growth. The differences between forest and pasture land cover are increasing in all seasons year by year. The greatest streamflow reduction was observed in wet period (autumn and winter) with 76% of total reduction. In summer, streamflow reduction represents only 3% of total, however, represents 24.7% of discharge in this season. Streamflow reduction was related to increase of rainfall interception (mainly in wet periods) and the increase of evapotranspiration by plantation in dry periods. This article is protected by copyright. All rights reserved.

Beschreibung: Air flows from the atmosphere into an unconfined aquifer when the water table falls during pumping tests. Pumping test results in unconfined aquifers may be significantly affected by low-permeability zones (LPZs) near the initial water table position because they restrict the downward movement of air. A transient, three-dimensional (3D) air-water two-phase flow model is employed to investigate numerically the effects of local heterogeneity on pumping test results in unconfined aquifers. Two cases of local heterogeneities are considered herein: a LPZ around the pumping well and on one side of the pumping well. Results show that the drawdown with the LPZ is significantly greater than that of the homogeneous aquifer. The differences in drawdown are the most significant at intermediate times and gradually diminish at later times. The LPZ significantly reduces air flow from the atmosphere to the aquifer. The pore air velocity in the LPZ is very low. The air pressure at the observation point under the LPZ when air begins to enter is significantly lower than the air pressure of the homogeneous aquifer at the same point. After that, the air pressure increases quickly and then increases slowly. The time for the air pressure to reach the atmospheric pressure is significantly longer. This article is protected by copyright. All rights reserved.

Beschreibung: Over the last half century, since logging for timber production became intensive, Borneo has lost much of its pristine tropical forests. The long-term consequences of associated decline in precipitation are evident, and might, in turn, cause much more severe deforestation. This article is protected by copyright. All rights reserved.

Beschreibung: Where you sit in the sequence of your siblings may affect how you turn out – influencing health, height, intelligence and even sexuality        

Beschreibung: Plastic banknotes, used in some countries and now under consideration in the UK, may be better at spreading bacteria than traditional cotton-fibre notes        

Beschreibung: The bureaucracy of naming objects in space, virtual zombies, the wider benefits of vaccines, and more        

Beschreibung: New revelations from former NSA contractor Edward Snowden expose how spy agencies in the US and UK might compel tech firms to help them bypass encryption        

Beschreibung: The latest change in G, the gravitational constant, can't be ignored – and might be a sign that one explanation for mysterious dark energy is right        

Beschreibung: Australia's new government is scrapping the country's main carbon-reduction policies and replacing them with a strategy that experts say is likely to fail        

Beschreibung: The DARPA Robotics Challenge will see humanoid robots competing to complete rescue missions, and could lead to robots better adapted to living alongside us        

Beschreibung: The ocean becomes more acid when a tropical storm passes through, posing an additional threat to stressed coral reefs        

Beschreibung: For the first time, full DNA profiles have been extracted from hairs and tiny sweat samples. It was done by targeting free-floating genetic material        

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Beschreibung: It is thought to be a perfect recipe for destroying marine life, but studies are suggesting that trawling the seabed could help some fish thrive in some places        

Beschreibung: A system that detects when a piece of text has been plagiarised could stop would-be cheaters using Google Translate to get them out of a course work hole        

Beschreibung: LADEE launch; Mars trip applicants; Szechuan buzz, and more        

Beschreibung: The first comparison of the two quitting aids finds that smokers who use electronic cigarettes are as successful as those using the gold standard approach        

Beschreibung: A remote region of north-west Kenya is sitting on 250 trillion litres of groundwater – enough to keep 40 million people in water if tapped sustainably        

Beschreibung: For the first time, neuroscientists have spotted existing memories recombining to imagine an all-new experience        

Beschreibung: Male mosquitofish with many predators may have evolved genitalia that are suited to speedy love-making        

Beschreibung: Shadows in high resolution imagery create significant problems for urban land cover classification and environmental application. We first investigated whether shadows were intrinsically different and hypothetically possible to separate from each other with ground spectral measurements. Both pixel-based and object-oriented methods were used to evaluate the effects of shadow detection on QuickBird image classification and spectroradiometric restoration. In each method, shadows were detected and separated either with or without histogram thresholding, and subsequently corrected with a k-nearest neighbor algorithm and a linear correlation correction. The results showed that shadows had distinct spectroradiometric characteristics, thus, could be detected with an optimal brightness threshold and further differentiated with a scene-based near infrared ratio. The pixel-based methods generally recognized more shadow areas and with statistically higher accuracy than the object-oriented methods. The effects of the prior shadow thresholding were not statistically significant. The accuracy of the final land cover classification, after accounting for the shadow detection and separation, was significantly higher for the pixel-based methods than for the object-oriented methods, although both achieved similar accuracy for the non-shadow classes. Both radiometric restoration algorithms significantly reduced shadow areas in the original satellite images.

Beschreibung: Despite longstanding contributions to oceanography, similar use of fluorescence light detection and ranging (LiDAR) in lake settings is not routine. The potential for ship-mounted, multispectral Ultraviolet Fluorescence LiDAR (UFL) to provide rapid, high-resolution data in variably turbid and productive lake conditions are investigated here through a series of laboratory tank and field measurements carried out on Lake Balaton, Hungary. UFL data, calibrated empirically to a set of coinciding conventionally-analyzed samples, provide simultaneous estimates of three important parameters-chlorophyll a(chla), total suspended matter (TSM) and colored dissolved organic matter (CDOM). Successful UFL retrievals from both laboratory and field measurements were achieved for chla (0.01–378 mg∙m−3; R = 0.83–0.92), TSM (0.1–130 g∙m−3; R = 0.90–0.96) and CDOM (0.003–0.125 aCDOM(440); R = 0.80–0.97). Fluorescence emission at 685 nm is shown through tank measurements to display robust but distinct relationships with chla concentration for the two cultured algae species investigated (cyanobacteria, Cylindrospermopsis raciborskii, and chlorophyta, Scenedesmus armatus). The ratio between fluorescence emissions measured at 650 nm, related to the phycocyanin fluorescence maximum, to that at 685 nm is demonstrated to effectively distinguish these two species. Validation through both laboratory measurements and field measurements confirmed that site specific calibration is necessary. This study presents the first known assessment and application of ship-mounted fluorescence LiDAR in freshwater lake conditions and demonstrates the use of UFL in measuring important water quality parameters despite the more complicated hydro-optic conditions of inland waters.

Beschreibung: Accepting the concept of standardization introduced by the standardized precipitation index (SPI), similar methodologies have been developed to construct some other standardized drought indices such as the standardized precipitation evapotranspiration index (SPEI). In this study, the authors provided deep insight into the SPEI and recognized potential deficiencies/limitations in relating to the climatic water balance it used. By coupling another well-known Palmer drought severity index (PDSI), we proposed a new standardized Palmer drought index (SPDI) through a moisture departure probabilistic approach, which allows multiscalar calculation for accurate temporal and spatial comparison of the hydro-meteorological conditions of different locations. Using datasets of monthly precipitation, temperature and soil available water capacity, the moisture deficit/surplus was calculated at multiple temporal scales and a couple of techniques were adopted to adjust corresponding time series to a generalized extreme value distribution out of several candidates. Results of the historical records (1900–2012) for diverse climates by multiple indices showed that the SPDI was highly consistent and correlated with the SPEI and self-calibrated PDSI (SC-PDSI) at most analyzed time scales. Furthermore, a simple experiment of hypothetical temperature and/or precipitation change scenarios also verified the effectiveness of this newly-derived SPDI index in response to climate change impacts. Being more robust and preferable in spatial consistency and comparability as well as combining the simplicity of calculation with sufficient accounting of the physical nature of water supply and demand relating to droughts, the SPDI is promising to serve as a competent reference and alternative for drought assessment and monitoring. This article is protected by copyright. All rights reserved.

Beschreibung: Modeled hydrologic processes are represented in a set of numerical equations, the complexity of which can be measured by the total number of variables needed. A single dominant hydrologic process could control the hydrologic response of a watershed, and so the identification of the corresponding dominant variable(s) would aid in identifying a parsimonious model and in collecting more reliable data. By accounting for both model complexity and serial correlation in the variables, a model is used to identify the dominant variables for representing watershed scale streamflow, sediment transport, and phosphorus yields. Long-term water quantity and quality data was used to show that rainfall and non-linear soil water storage were the dominant variables for weekly streamflow, suspended sediment, and particulate phosphorus. Model accuracy did not consistently improve when other statistically significant variables were included. The results suggest that improved model performance may not justify the added model complexity. As such, identification of dominant variables would be the priority for developing parsimonious hydrologic models, especially at watershed scales. This article is protected by copyright. All rights reserved.

Beschreibung: ABSTRACT The objective of this study was to analyze the dentin-resin cements interfacial ultramorphologies using two different methods: scanning (SEM) and transmission electron microscopy (TEM). Four commercial products were evaluated: two conventional cementing system (RelyX ARC/Adper™ Scotchbond™ Multi-Purpose Plus, 3M ESPE and Clearfil Esthetic Cement/DC Bond, Kuraray) and two self-adhesive resin cements (RelyX Unicem, 3M ESPE and Clearfil SA Cement, Kuraray). Prepolymerized resin disks (Sinfony, 3M ESPE) were cemented on oclusal dentin surfaces of 24 third human molars, simulating the indirect restorations. After 24 h, teeth were sectioned into 0.9-mm thick slabs and processed for microscopy analyses (SEM or TEM/ n = 3). Qualitative characterization of dentin-resin cement interface was performed. Hybrid layer formation with long and dense resin tags was observed only for RelyX ARC cementing system. Clearfil Esthetic Cement/DC Bond system revealed few and short resin tags formation, whereas no hybridization and resin tags were detected for self-adhesive resin cements. Some interfacial regions exhibited that the self-adhesive resin cements were not bonded to dentin, presenting bubbles or voids at the interfaces. In conclusion, TEM and SEM bonding interface analyses showed ultramorphological variations among resin cements, which are directly related to dental bonding strategies used for each resin cement tested. Microsc. Res. Tech., 2013 . © 2013 Wiley Periodicals, Inc.

Beschreibung: ABSTRACT Mimosa pudica has three distinct specialized organs, namely, pulvinus, secondary pulvinus, and pulvinule, which are respectively controlling the movements of petioles, leaflets, and pinna in response to external stimuli. Water flow is a key factor for such movements, but detailed studies on the organization of the vascular system for water transport in these organs have not been published yet. In this study, organizations of the xylem vessels and morphological features of the pulvinus, the secondary pulvinus, and the pulvinule were experimentally investigated by X-ray computed tomography and histological technique. Results showed that the xylem vessels were circularly distributed in the specialized motile organs and reorganized into distinct vascular bundles at the extremities. The number and the total cross-sectional area of the xylem vessels were increased inside the specialized motile organs. Morphological characteristics obtained in this study provided new insight to understand the functions of the vascular networks in the dynamic movements of M. pudica . Microsc. Res. Tech., 2013 . © 2013 Wiley Periodicals, Inc.

Beschreibung: Aquaculture coasts have become widely distributed in coastal zones as human activities are intensified. Due to the complexity in this type of coast, it is difficult to extract the coastline with traditional automated mapping approaches. In this paper, we present an automated method—object-based region growing integrating edge detection (OBRGIE) for the extraction of this type of coastline. In this method, a new object feature named OMI (object merging index) is proposed to separate land and sea. The OBRGIE method was applied to Landsat Thematic Mapper (TM) (pixel size 30m) and Satellite Pour l’Observation de la Terre (SPOT-5) (pixel size 10 m) images of two coastal segments with lengths of 272.7 km and 35.5 km respectively, and the accuracy of the extracted coastlines was assessed in comparison with the manually delineated coastlines. The mean and RMSE (root mean square error) are 16.0 m and 16.4 m respectively for the TM images, and 8.0 m and 8.6 m, respectively, for the SPOT-5 images, indicating that the proposed method derives coastlines with pixel accuracy. The OBRGIE method is also found to be robust to the segmentation scale parameter, and the OMI feature is much more effective than the spectral attribute in separating land and sea in aquaculture coasts. This method may provide an inexpensive means of fast coastline mapping from remotely sensed imagery with relatively fine-to-moderate spatial resolution in coastal sectors with intense human interference.

Beschreibung: A study was undertaken to assess Envisat Advanced Synthetic Aperture Radar (ASAR) ScanSAR data for quantifying forest growing stock volume (GSV) across three boreal regions with varying forest types, composition, and structure (Sweden, Central Siberia, and Québec). Estimates of GSV were obtained using hyper-temporal observations of the radar backscatter acquired by Envisat ASAR with the BIOMASAR algorithm. In total, 5.3×106 km2 were mapped with a 0.01° pixel size to obtain estimates representative for the year of 2005. Comparing the SAR-based estimates to spatially explicit datasets of GSV, generated from forest field inventory and/or Earth Observation data, revealed similar spatial distributions of GSV. Nonetheless, the weak sensitivity of C-band backscatter to forest structural parameters introduced significant uncertainty to the estimated GSV at full resolution. Further discrepancies were observed in the case of different scales of the ASAR and the reference GSV and in areas of fragmented landscapes. Aggregation to 0.1° and 0.5° was then undertaken to generate coarse scale estimates of GSV. The agreement between ASAR and the reference GSV datasets improved; the relative difference at 0.5° was consistently within a magnitude of 20–30%. The results indicate an improvement of the characterization of forest GSV in the boreal zone with respect to currently available information.

Beschreibung: Who needs a rocket to send things to space when you can use a balloon? That's the idea of Chris Rose and Alex Baker , who have set up a firm to do just that        

Beschreibung: The Multi-angle Imaging SpectroRadiometer (MISR) instrument aboard the Terra satellite acquires imagery at 275-m resolution at nine angles ranging from 0° (nadir) to 70° off-nadir. This multi-angle capability facilitates the stereoscopic retrieval of heights and motion vectors for clouds and aerosol plumes. MISR’s operational stereo product uses this capability to retrieve cloud heights and winds for every satellite orbit, yielding global coverage every nine days. The MISR INteractive eXplorer (MINX) visualization and analysis tool complements the operational stereo product by providing users the ability to retrieve heights and winds locally for detailed studies of smoke, dust and volcanic ash plumes, as well as clouds, at higher spatial resolution and with greater precision than is possible with the operational product or with other space-based, passive, remote sensing instruments. This ability to investigate plume geometry and dynamics is becoming increasingly important as climate and air quality studies require greater knowledge about the injection of aerosols and the location of clouds within the atmosphere. MINX incorporates features that allow users to customize their stereo retrievals for optimum results under varying aerosol and underlying surface conditions. This paper discusses the stereo retrieval algorithms and retrieval options in MINX, and provides appropriate examples to explain how the program can be used to achieve the best results.

Beschreibung: Roads play an indispensable role as part of the infrastructure of society. In recent years, society has witnessed the rapid development of laser mobile mapping systems (LMMS) which, at high measurement rates, acquire dense and accurate point cloud data. This paper presents a way to automatically estimate the required excavation volume when widening a road from point cloud data acquired by an LMMS. Firstly, the input point cloud is down-sampled to a uniform grid and outliers are removed. For each of the resulting grid points, both on and off the road, the local surface normal and 2D slope are estimated. Normals and slopes are consecutively used to separate road from off-road points which enables the estimation of the road centerline and road boundaries. In the final step, the left and right side of the road points are sliced in 1-m slices up to a distance of 4 m, perpendicular to the roadside. Determining and summing each sliced volume enables the estimation of the required excavation for a widening of the road on the left or on the right side. The procedure, including a quality analysis, is demonstrated on a stretch of a mountain road that is approximately 132 m long as sampled by a Lynx LMMS. The results in this particular case show that the required excavation volume on the left side is 8% more than that on the right side. In addition, the error in the results is assessed in two ways. First, by adding up estimated local errors, and second, by comparing results from two different datasets sampling the same piece of road both acquired by the Lynx LMMS. Results of both approaches indicate that the error in the estimated volume is below 4%. The proposed method is relatively easy to implement and runs smoothly on a desktop PC. The whole workflow of the LMMS data acquisition and subsequent volume computation can be completed in one or two days and provides road engineers with much more detail than traditional single-point surveying methods such as Total Station or GPS profiling. A drawback is that an LMMS system can only sample what is within the view of the system from the road.

Beschreibung: If you need a bit of help to wade through an argument, reach for Occam's razor, Sturgeon's law or the good old rhetorical question, says Graham Lawton        

Beschreibung: What are thoughts, and what exactly is thinking? Take a trip with philosopher Tim Bayne into the fantastic, ceaseless world our minds create        

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Beschreibung: The arguments against releasing genetically modified insects to control pests and diseases are old and tired        

Beschreibung: Ocean-going robots off the east coast of the US promise to predict the magnitude of hurricanes with unprecedented accuracy        

Beschreibung: Orbital Sciences is preparing to dock its Cygnus craft with the International Space Station, a move that could be a giant leap for science, industry – and humanity        

Beschreibung: As UN inspectors announce that sarin was used, US and Russia have called for "extraordinary procedures" to destroy Syrian chemical weapons by next July        

Beschreibung: A healthy lifestyle increases the length of telomeres, the protective caps on our chromosomes that wear away with age        

Beschreibung: At present continental to global scale flood forecasting predicts at a point discharge, with little attention to detail and accuracy of local scale inundation predictions. Yet, inundation variables are of interest and all flood impacts are inherently local in nature. This paper proposes a large scale flood inundation ensemble forecasting model that uses best available data and modeling approaches in data scarce areas. The model was built for the Lower Zambezi River to demonstrate current flood inundation forecasting capabilities in large data-scarce regions. ECMWF ensemble forecast (ENS) data were used to force the VIC (Variable Infiltration Capacity) hydrological model, which simulated and routed daily flows to the input boundary locations of a 2-D hydrodynamic model. Efficient hydrodynamic modeling over large areas still requires model grid resolutions that are typically larger than the width of channels that play a key a role in flood wave propagation. We therefore employed a novel sub-grid channel scheme to describe the river network in detail whilst representing the floodplain at an appropriate scale. The modeling system was calibrated using channel water levels from satellite laser altimetry and then applied to predict the February 2007 Mozambique floods. Model evaluation showed that simulated flood edge cells were within a distance of between one and two model resolutions compared to an observed flood edge and inundation area agreement was on average 86%. Our study highlights that physically plausible parameter values and satisfactory performance can be achieved at spatial scales ranging from tens to several hundreds of thousands of km 2 and at model grid resolutions up to several km 2 .

Beschreibung: A class of capillary flows in unsaturated porous media is characterized by quasi-steady viscous flow confined behind curved air-water interfaces and within liquid bodies held by capillary forces along crevices and grain contacts. The geometry of the connected capillary liquid network within the pore space resembles channels that form between adjacent bubbles in foam (Plateau borders) with solid grains representing gas bubbles in foam. For simplified channel geometry we combine expressions for viscous flow with continuity considerations to describe the evolution of the channels cross-sectional area during gravity drainage. This formulation enables modeling of unsaturated flow without invoking the Richards equation and associated hydraulic functions. We adapt a formalism originally developed for foam “free drainage” (drainage under gravity) or “forced drainage” (infiltration front motion) to a class of unsaturated flows in porous media that require a few input parameters only (mean channel corner angle, air entry value and porosity) for certain initial and boundary conditions. We demonstrate that the reduction in capillary channel cross section yields a consistent description of self-regulating internal fluxes towards attainment of the so-called “field capacity” in soil and provides an alternative method for interpretation of outflow experiments for prescribed pressure boundary conditions. Additionally, the geometrically-explicit formulation provides a more intuitive picture of capillary flows across textural boundaries (changes in channel cross-section and number of channels). The foam drainage methodology expands the range of tools available for analyses of unsaturated flow processes and offers more realistic links between liquid configuration and flow dynamics in unsaturated porous media.

Beschreibung: Synthetic streamflows at different sites in a river basin are needed for planning, operation and management of water resources projects. Modeling the temporal and spatial dependence structure of monthly streamflow at different sites is generally required. In this study, the maximum entropy copula method is proposed for multisite monthly streamflow simulation, in which the temporal and spatial dependence structure is imposed as constraints to derive the maximum entropy copula. The monthly streamflows at different sites are then generated by sampling from the conditional distribution. A case study for the generation of monthly streamflow at three sites in the Colorado River basin illustrates the application of the proposed method. Simulated streamflow from the maximum entropy copula is in satisfactory agreement with observed streamflow.

Beschreibung: The Krycklan Catchment Study (KCS) provides a unique field infrastructure for hillslope to landscape-scale research on short and long-term ecosystem dynamics in boreal landscapes. The site is designed for process-based research assessing the role of external drivers including forest management, climate change, and long-range pollutant transport on forests, mires, soils, streams, lakes and groundwater. The over-arching objectives of KCS are to (1) provide a state-of-the-art infrastructure for experimental and hypothesis driven research, (2) maintain a collection of high quality, long-term climatic, biogeochemical, hydrological and environmental data, and (3) support the development of models and guidelines for research, policy and management.

Beschreibung: 3-D Hydraulic Tomography (3-D HT) is a method for aquifer characterization whereby the 3-D spatial distribution of aquifer flow parameters (primarily hydraulic conductivity, K) is estimated by joint inversion of head change data from multiple partially-penetrating pumping tests. While performance of 3-D HT has been studied extensively in numerical experiments, few field studies have demonstrated the real-world performance of 3-D HT. Here we report on a 3-D transient hydraulic tomography (3-D THT) field experiment at the Boise Hydrogeophysical Research Site which is different from prior approaches in that it represents a “baseline” analysis of 3-D THT performance using only a single arrangement of a central pumping well and 5 observation wells with nearly complete pumping and observation coverage at 1m intervals. We jointly analyze all pumping tests using a geostatistical approach based on the quasi-linear estimator of kitanidis [1995]. We reanalyze the system after progressively removing pumping and/or observation intervals; significant progressive loss of information about heterogeneity is quantified as reduced variance of the K field overall, reduced correlation with slug test K estimates at wells, and reduced ability to accurately predict independent pumping tests. We verify that imaging accuracy is strongly improved by pumping and observational densities comparable to the aquifer heterogeneity geostatistical correlation lengths. Discrepancies between K profiles at wells, as obtained from HT and slug tests, are greatest at the tops and bottoms of wells where HT observation coverage was lacking.

Beschreibung: We applied graphical methods and multivariate statistics to understand impacts of an unsewered slum catchment on nutrients and hydrochemistry of groundwater in Kampala, Uganda. Data was collected from 56 springs (groundwater), 22 surface water sites and 13 rain samples. Groundwater was acidic and dominated by Na, Cl and NO 3 . These ions were strongly correlated indicating pollution originating from wastewater infiltration from on-site sanitation systems. Results also showed that rain, which was acidic, impacted on groundwater chemistry. Using Q-mode hierarchical cluster analysis, we identified three distinct water quality groups. The first group had springs dominated by Ca-Cl-NO 3 , low values of EC, pH and cations, and relatively high NO 3 values. These springs were shown to have originated from the acidic rains because their chemistry closely corresponded to ion concentrations that would occur from rainfall recharge, which was around 3.3 times concentrated by evaporation. The second group had springs dominated by Na-K-Cl-NO 3 and Ca-Cl-NO 3 , low pH but with higher values of EC, NO 3 and cations. We interpreted these as groundwater affected by both acid rain and infiltration of wastewater from urban areas. The third group had the highest EC values (average of 688 μS/cm), low pH and very high concentrations of NO 3 (average of 2.15 mmol/L) and cations. These springs were exclusively located in slum areas and we interpreted these springs as groundwater affected by infiltration of wastewater from poorly sanitized slums areas. Surface water was slightly reducing and eutrophic due to wastewater effluents, but the contribution of groundwater to nutrients in surface water was minimal because o-PO 4 was absent whereas NO 3 was lost by denitification. Our findings suggest that groundwater chemistry in the catchment is strongly influenced by anthropogenic inputs derived from nitrogen-containing rains and domestic wastewater. This article is protected by copyright. All rights reserved.

Beschreibung: A key factor in our evolution is so deeply ingrained in our lives that we barely notice it. Disgustologist Valerie Curtis lifts the lid on manners        

Beschreibung: After all the excitement surrounding the discovery of the Higgs, a new book called Beyond the God Particle asks where we go next        

Beschreibung: Probabilistic estimates of future water levels and river discharge are usually simulated with hydrologic models using ensemble weather forecasts as main inputs. As hydrologic models are imperfect and the meteorological ensembles tend to be biased and underdispersed, the ensemble forecasts for river runoff typically are biased and underdispersed, too. Thus, in order to achieve both reliable and sharp predictions statistical post-processing is required. In this work Bayesian model averaging (BMA) is applied to statistically post-process ensemble runoff raw forecasts for a catchment in Switzerland, at lead-times ranging from 1 to 240 hours. The raw forecasts have been obtained using deterministic and ensemble forcing meteorological models with different forecast lead-time ranges. First, BMA is applied based on mixtures of univariate normal distributions, subject to the assumption of independence between distinct lead-times. Then, the independence assumption is relaxed in order to estimate multivariate runoff forecasts over the entire range of lead-times simultaneously, based on a BMA version that uses multivariate normal distributions. Since river runoff is a highly skewed variable, Box-Cox transformations are applied in order to achieve approximate normality. Both univariate and multivariate BMA approaches are able to generate well calibrated probabilistic forecasts that are considerably sharper than climatological forecasts. Additionally, multivariate BMA provides a promising approach for incorporating temporal dependencies into the post-processed forecasts. Its major advantage against univariate BMA is an increase in reliability when the forecast system is changing due to model availability.

Beschreibung: We derive a series solution for the nonlinear Boussinesq equation in terms of the similarity variable of the Boltzmann transformation in a semi-infinite domain. The first few coefficients of the series have been known for a long time, having been obtained by a truncated inversion of the series solution of the Blasius equation, but no direct recurrence relation was known for the complete series representing the solution of the Boussinesq equation. The series turns out to have a finite radius of convergence, which we estimate with a numerical complex-plane integration method that identifies the singularities of the solution when the equation is extended to the complex plane. The homogeneous condition at the origin produces a singularity which complicates numerical solutions with Runge-Kutta methods. We present two variable transformations that circumvent the problem and that are best suited to the complex-variable and the real-variable versions of the equation, respectively. Using those tools, an approximate solution accurate to 1.75 × 10 -10 and valid for the entire positive real axis is then developed by matching a Padé approximant of the exact series and an asymptotic solution (to overcome the restriction imposed by the finite radius of convergence of the series), along the same lines of the expression proposed by Hogarth and Parlange [1999]. The accuracies of all of the existing and the newly proposed solutions are obtained.

Beschreibung: Field sampling in unwadeable and flashy flood events encounters the problem that lateral variability of flow hydraulics and sediment transport cannot be captured adequately, and there is also an accuracy problem because parameters change while being measured. Moreover, event based gravel-sand mixed transport data in rapidly changing conditions are largely missing, in particular for gravel-bed rivers in small catchments. In this study, field measurements of bed load, suspended load, flow velocities, water depths and cross section geometry were collected during flood events at a monitoring station near the mouth of the Versilia river, Italy. Since the observed hydrographs are characterized by short durations, to the order of a few hours, an analysis of the lateral and temporal flow variability was carried out to enable the design of a sampling strategy and to minimize the errors created by the time variations of discharge associated with unsteady flow conditions. The measurements were interpreted using a 1D hydro-morphodynamic numerical model simulating the dynamics of flow and sediment discharges during a flood event for a given return period. The flow and sediment rating curves were then developed through an integrated approach combining different methodologies: field measurements, laboratory analyses and mathematical modeling. The developed approach allows one to capture the main physical mechanisms associated to the transport of sand–gravel mixtures, such as selective transport, and the hysteretic behaviour of sediment transport produced by rapid and intense flood events.

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Beschreibung: Infinity's not such a big problem; opening the factory gates to hackers; our solar day of reckoning        

Beschreibung: A sensor previously used for military operations can now be tuned to secretly locate and record any single conversation on a busy street        

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Beschreibung: Exposing sleeping people to smells linked with something they fear is the first step towards a stress-free way to overcome phobias        

Beschreibung: A life-sized, anatomically accurate model of a four-winged dinosaur supports the notion that feathers might not have evolved first for flight        

Beschreibung: The weak force is the only fundamental force to treat objects and their mirror images differently – raising hopes that it might point the way to new physics        

Beschreibung: When it comes to climate change, facts don't speak for themselves. Communicators need to find better ways to connect, says Adam Corner        

Beschreibung: Giving cellular powerhouses a jump-start grants old mice a new lease of life, improving their memory and exercise performance        

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Beschreibung: The Mars rover's first deep breaths are methane-free, contradicting previous results that hinted at life        

Beschreibung: Increases in the availability of antiviral therapies have halved the number of new HIV infections in children since 2001        

Beschreibung: Before plate tectonics kicked in, our planet was a lot like Jupiter's volcanic moon Io, spewing lava through heat pipes that built our strong, rigid crust        

Beschreibung: Cygnus was due to be the second private craft to dock with the ISS on Sunday, but will have to wait its turn after getting GPS data in the wrong format        

Beschreibung: The lack of evidence on firearms violence can, ironically, be turned to the advantage of gun control advocates if they get their story straight        

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Beschreibung: The supermassive black hole at the centre of our galaxy may have flared up some 2 million years ago, around the time our ancestors learned to walk upright        

Beschreibung: The enormous, bottom-dwelling coelacanths have sprung another surprise: unlike other fish species, each female's clutch of young has the same father        

Beschreibung: North Korean nukes, wrinkle pill vinidicated, in-flight electronic playback and more        

Beschreibung: The slow movement of active deep-seated slope gravitational deformations (DSGSDs) and deep-seated rockslides can cause damage to structures and infrastructures. We use Permanent Scatterers Synthetic Aperture Radar Interferometry (PSInSAR™) displacement rate data for the analysis of DSGSD/rockslide activity and kinematics and for the analysis of damage to buildings. We surveyed the degree of damage to buildings directly in the field, and we tried to correlate it with the superficial displacement rate obtained by the PSInSAR™ technique at seven sites. Overall, we observe that the degree of damage increases with increasing displacement rate, but this trend shows a large dispersion that can be due to different causes, including: the uncertainty in the attribution of the degree of damage for buildings presenting wall coatings; the complexity of the deformation for large phenomena with different materials and subjected to differential behavior within the displaced mass; the absence of differential superficial movements in buildings, due to the large size of the investigated phenomena; and the different types of buildings and their position along the slope or relative to landslide portions.

Beschreibung: Oft championed as brain boosters, omega-3s from nuts and fish don't seem to improve memory or motor skills in older women        

Beschreibung: Living things have a huge influence on our planet. Earth without life would be very different place, finds Bob Holmes        

Beschreibung: Should the outcome of an ongoing legal battle put an end to positive discrimination in university applications, the resulting loss of diversity would be bad news for all students        

Beschreibung: As societies mature, many outgrow the need for a spiritual superbeing, argues Big Gods: How religion transformed cooperation and conflict        

Beschreibung: NASA is rebooting its Mars landings, thanks to a smart idea from the cold war era, and high-stakes rocket tests in the desert. Sally Adee looks on        

Beschreibung: The highly caustic Lake Natron in Tanzania kills most animals unlucky enough to enter the water – and calcifies them        

Beschreibung: A 30-year series of global monthly Normalized Difference Vegetation Index (NDVI) imagery derived from the Global Inventory Modeling and Mapping Studies (GIMMS) NDVI3g archive was analyzed for the presence of trends in changing seasonality. Using the Seasonal Trend Analysis (STA) procedure, over half (56.30%) of land surfaces were found to exhibit significant trends. Almost half (46.10%) of the significant trends belonged to three classes of seasonal trends (or changes). Class 1 consisted of areas that experienced a uniform increase in NDVI throughout the year, and was primarily associated with forested areas, particularly broadleaf forests. Class 2 consisted of areas experiencing an increase in the amplitude of the annual seasonal signal whereby increases in NDVI in the green season were balanced by decreases in the brown season. These areas were found primarily in grassland and shrubland regions. Class 3 was found primarily in the Taiga and Tundra biomes and exhibited increases in the annual summer peak in NDVI. While no single attribution of cause could be determined for each of these classes, it was evident that they are primarily found in natural areas (as opposed to anthropogenic land cover conversions) and that they are consistent with climate-related ameliorations of growing conditions during the study period.

Beschreibung: We examined the water balance a forested ombrotrophic peatland and adjacent burned peatland in the boreal plain of western Canada over a three-year period. Complete combustion of foliage and fine branches dramatically increased shortwave radiation inputs to the peat surface while halting all tree transpiration at the burned site. End-of-winter snowpack was 7-25% higher at the burned site likely due to decreased ablation from the tree canopy at the unburned site. Shrub regrowth at the burned site was rapid post-fire, and shading by the shrub canopy in the burned site approached that of the unburned site within three years after fire. Site-averaged surface resistance to evaporation was not different between sites, though surface resistance in hollows was lower in the burned site. Water loss at both burned and unburned sites is largely driven by surface evaporative losses. Evaporation at the burned site marginally exceeded the sum of pre-fire transpiration and interception at the unburned site, suggesting that ET during the growing season was 2 0–40  mm greater at the the burned peatland. While the net change in water storage during the growing season was largely unchanged by fire, the lack of low-density surface peat in the burned site appears to have decreased specific yield, leading to greater water table decline at the burned site despite similar net change in storage. This article is protected by copyright. All rights reserved.

Beschreibung: The eddy covariance (EC) method was used in a 30-month study to quantify evapotranspiration (ET) and vegetation coefficient (K CW ) for a wetland on a ranch in subtropical south Florida. To evaluate the errors in ET estimates, the EC-based ET (ET C.-EC ) and the Food and Agricultural Organization (FAO) Penman-Monteith (PM) based ET (ET C.-PM ) estimates (with literature crop coefficient K C ) were compared to each other. The ET C.-EC and FAO-PM reference ET were used to develop K CW . Regression models were developed to estimate K CW using climatic and hydrologic variables. Annual and daily ET C.-EC values were 1152 mm and 3.27 mm, respectively. The FAO-PM model underestimated ET by 25% with ET C.-EC being statistically higher than ET C.-PM . The K CW varied from 0.79 (December) to 1.06 (November). The mean K CW for dry (November-April) season (0.95) was much higher than values reported for wetlands in literature, while wet (May-October) season K CW (0.97) was closer to literature values. Higher than expected K CW values during dry season were due to higher temperature, lower humidity and perennial wetland vegetation. Regression analyses showed that factors affecting the K CW were different during the dry (soil moisture, temperature, and relative humidity) and wet (net radiation, inundation, and wind speed) seasons. Separate regression models for the dry and wet seasons were developed. ET and K CW from this study, one of the first for the agricultural wetlands in subtropical environment, will help improve the ET estimates for similar wetlands. This article is protected by copyright. All rights reserved.

Beschreibung: For over 30 years emergency room doctor Garen Wintemute has studied gun violence in the US. He explains how a lack of funding has made the problem intractable        

Beschreibung: From whizzy guides to funky apps, it's an exciting time for amateur and professional naturalists alike        

Beschreibung: The idea that sadistic childhood abuse could lead to multiple personality disorder has seized the public imagination, but could it be a diagnostic fad?        

Beschreibung: Research on runoff processes to date has focused on the differences between the main divisions of runoff partitioning. Indeed, our major advancements in runoff theory have come with new differentiations of different forms of overland flow and subsurface stormflow. These studies of ‘how runoff processes are different’ have resulted in our current summaries of runoff regimes conceptually (e.g. the Variable Source Area (VSA) concept) and codified in our models (e.g. TOPMODEL and its derivatives). This article is protected by copyright. All rights reserved.

Beschreibung: ABSTRACT A study was performed to characterize over land precipitation associated with tropical cyclones (TCs) for basins around the world based upon the International Best Track Archive for Climate Stewardship (IBTrACS). From 1998 to 2009, data from the Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA) product 3B42, showed that TCs accounted for 5.5%, 7.5%, 6%, 9.5%, and 8.9% of the annual precipitation for impacted over land areas of the Americas, East Asia, South and West Asia, Oceania, and East Africa respectively, and that TC contribution decreased significantly within the first 150-km from the coast. Locally, TCs contributed on average to more than 25% and up to 61% of the annual precipitation budget over very different climatic areas with arid or tropical characteristics. East Asia represented the higher and most constant TC rain (118±19% mm y -1 ) normalized over the area impacted, while East Africa presented the highest variability (108±60% mm y -1 ), and the Americas displayed the lowest average TC rain (65±24% mm y -1 ) despite a higher TC activity. Furthermore, the maximum monthly TC contribution (8-11%) was found later in the TC season and depended on the peak of TC activity, TC rainfall, and the domain transition between dry and wet regimes if any. Finally, because of their importance in terms of rainfall amount, the contribution of TCs was provided for a selection of 50 urban areas experiencing cyclonic activity. Results showed that for particularly intense years, urban areas prone to cyclonic activity received more than half of their annual rainfall from TCs.

Beschreibung: A multivariate, multi-site daily weather generator is presented for use in decision-centric vulnerability assessments under climate change. The tool is envisioned useful for a wide range of socioeconomic and biophysical systems sensitive to different aspects of climate variability and change. The proposed stochastic model has several components, including 1) a wavelet decomposition coupled to an autoregressive model to account for structured, low-frequency climate oscillations, 2) a Markov Chain and k-nearest-neighbor (KNN) resampling scheme to simulate spatially-distributed, multivariate weather variables over a region, and 3) a quantile mapping procedure to enforce long-term distributional shifts in weather variables that result from prescribed climate changes. The Markov Chain is used to better represent wet and dry spell statistics while the KNN bootstrap resampler preserves the covariance structure between the weather variables and across space. The wavelet-based autoregressive model is applied to annual climate over the region and used to modulate the Markov Chain and KNN resampling, embedding appropriate low-frequency structure within the daily weather generation process. Parameters can be altered in any of the components of the proposed model to enable the generation of realistic time series of climate variables that exhibit changes to both lower-order and higher-order statistics at long-term (inter-annual), mid-term (seasonal), and short-term (daily) timescales. The tool can be coupled with impact models in a bottom-up risk assessment to efficiently and exhaustively explore the potential climate changes under which a system is most vulnerable. An application of the weather generator is presented for the Connecticut River basin to demonstrate the tool's ability to generate a wide range of possible climate sequences over an extensive spatial domain.

Beschreibung: The objective of the least cost design problem of a water distribution system is to find its minimum cost with discrete diameters as decision variables and hydraulic controls as constraints. The goal of a robust least cost design is to find solutions which guarantee its feasibility independent of the data (i.e., under model uncertainty). A robust counterpart approach for linear uncertain problems is adopted in this study, which represents the uncertain stochastic problem as its deterministic equivalent. Robustness is controlled by a single parameter providing a trade-off between the probability of constraint violation and the objective cost. Two principal models are developed-uncorrelated uncertainty model with implicit design reliability, and correlated uncertainty model with explicit design reliability. The models are tested on three example applications and compared for uncertainty in consumers’ demands. The main contribution of this study is the inclusion of the ability to explicitly account for different correlations between water distribution systems demand nodes. In particular it is shown that including correlation information in the design phase has a substantial advantage in seeking more efficient robust solutions.

Beschreibung: Moving from univariate to multivariate frequency analysis, this study extends the Klemeš' critique of the widespread belief that the increasingly refined mathematical structures of probability functions increase the accuracy and credibility of the extrapolated upper tails of the fitted distribution models. In particular, we discuss key aspects of multivariate frequency analysis applied to hydrological data such as the selection of multivariate design events (i.e., appropriate subsets or scenarios of multiplets that exhibit the same joint probability to be used in design applications) and the assessment of the corresponding uncertainty. Since these problems are often overlooked or treated separately, and sometimes confused, we attempt to clarify properties, advantages, shortcomings and reliability of results of frequency analysis. We suggest a selection method of multivariate design events with prescribed joint probability based on simple Monte Carlo simulations that accounts for the uncertainty affecting the inference results and the multivariate extreme quantiles. It is also shown that the exploration of the p -level probability regions of a joint distribution returns a set of events that is a subset of the p -level scenarios resulting from an appropriate assessment of the sampling uncertainty, thus tending to overlook more extreme and potentially dangerous events with the same (uncertain) joint probability. Moreover, a quantitative assessment of the uncertainty of multivariate quantiles is provided by introducing the concept of joint confidence intervals. From an operational point of view, the simulated event sets describing the distribution of the multivariate p -level quantiles can be used to perform multivariate risk analysis under sampling uncertainty. As an example of the practical implications of this study, we analyse two case studies already presented in the literature.

Beschreibung: The discovery of huge temples thousands of years older than agriculture suggests that culture arose from spiritual hunger, not full bellies, says David Robson        

Beschreibung: Indo-European roots, atomic clock mechanics, photons in flatland, what people in comas really want and more        

Beschreibung: Particles of gravity could have their existence revealed in the cosmic microwave background, thanks to primordial ripples in space time        

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Beschreibung: The ability to protect the online data trails we generate is welcome, but it is no substitute for a proper public debate on who owns the information        

Beschreibung: Imagine printing out a paper computer and tearing off a corner to share – ink laced with silver nanoparticles could make it a reality, to the joy of hobbyists        

Beschreibung: Buried in an earthquake and cooked in the resulting fire, one of the oldest brains ever found may help open a window on the health of ancient people        

Beschreibung: The greatest source of climate uncertainty is political, not scientific. We can choose to limit warning, or we can take our chances in a hotter world        

Beschreibung: Using fractal-based algorithms that break an object down into a long, foldable chain, we can now 3D print and assemble items larger than the printer itself        

Beschreibung: The Red Planet's past was shaped by supervolcanoes akin to the one that sculpted Yellowstone National Park        

Beschreibung: A new fertility treatment awakens dormant follicles in women who have stopped menstruating, with the first test resulting in the birth of a baby boy        

Beschreibung: Roughly 800,000 "non-essential" government workers, including many key scientific and medical providers, are at home without pay