bluuebunny/crossref_metadata_2025_split huggingface dataset:
Post‐glacial range of variability in the Conejos River Valley, southern Colorado, USA: fluvial response to climate change and sediment supply
Authors: Layzell Anthony L. , Eppes Martha Cary , Johnson Bradley G. , Diemer John A. 
Published: April 2012

ABSTRACTEffective river management strategies require an understanding of how fluvial processes vary both spatially and temporally. Here, we examine the natural range of variability in the Conejos River Valley, southern Colorado, through documentation of terrace morphostratigraphic and sedimentological characteristics as well as through investigation of sediment contributions from headwaters, hillslopes and tributary streams. Additionally, soil development and radiocarbon ages, together with local and regional paleoclimate reconstructions, were used to infer the range of processes acting in this system.Since de‐glaciation, the Conejos River has fluctuated between episodes of bedrock strath formation, aggradation and vertical incision. Morphostratigraphic relationships, soil development and radiocarbon ages enable us to propose a chronology for periods of alluvial deposition (around 8·9–7·6 ka, 5·5 ka and from 3·5 to 1·1 ka), separated by intervals of fluvial incision. We infer potential forcing mechanisms by utilizing multiple working hypotheses. Specifically, we discuss the potential for increases in sediment supply during periods of (1) para‐glacial adjustment, (2) climatic cooling, (3) increased frequency of climate change and (4) increased fire frequency or severity. We also consider the effects of changes in stream discharge and extreme storm occurrence. We conclude that combinations of these processes, operating at different times, have contributed to sediment mobilization since de‐glaciation. Stream and landform morphology also varies longitudinally due to the influence of remnant glacial topography. In particular, valley bottom overdeepening at tributary junctions has resulted in incision and strath formation into unlithified glacial deposits (i.e. fill‐cut terraces) rather than bedrock in some reaches. Overall, the Conejos fluvial system has varied significantly both temporally and spatially since de‐glaciation and appears to be sensitive to changes in sediment supply related to Holocene scale climate fluctuations. This natural range of variability must therefore be a key consideration in any future stream management policies. Copyright © 2012 John Wiley & Sons, Ltd.
Surface lowering of limestone pavement as determined by cosmogenic (36Cl) analysis
Authors: Wilson Peter , Barrows Timothy T. , Lord Tom C. , Vincent Peter J. 
Published: April 2012

ABSTRACTDetermination of the rate and total amount of limestone pavement surface lowering is a critical issue in developing models of regional landscape change in limestone terrain. Erratic‐capped pedestals have frequently been used for this purpose but problems concerning definition and measurement of pedestal height, and the absence of a secure timeframe for erratic emplacement, have resulted in conflicting interpretations. We have used cosmogenic (36Cl) to establish the emplacement age of erratic boulders and the total amount of pavement surface lowering at sites in northwest England. Since erratic emplacement at 17.9 ka the limestone pavement has been lowered by 22–45 cm (average: 33 ± 10 cm), assuming lowering was continuous. Although indicating some spatial heterogeneity, the results contrast with earlier reported values based on the measurement of pedestal heights and inferred age for deglaciation. We consider that changes in climate and the character and duration of regolith covers to have been important influences in promoting surface lowering. It is argued that nivation (chemical and mechanical snow‐related processes) associated with several cool/cold periods is likely to have played an important role in surface lowering. Complicating factors associated with surface lowering (thickness and longevity of snow and regolith covers) are identified but as yet cannot be quantified. Copyright © 2012 John Wiley & Sons, Ltd.
Effects of C60 on the Salmonella typhimurium TA100 transcriptome expression: Insights into C60-mediated growth inhibition and mutagenicity
Authors: Hancock Dawn E. , Indest Karl J. , Gust Kurt A. , Kennedy Alan J. 
Published: April 2012

Abstract
Rapid advances are being made in the creation and use of nanomaterials, but little is known about the impact these materials might have on key microbial functions if introduced into the environment. Previous studies have generated conflicting results with respect to the impact of fullerenes on microbial activity. In the present study, Salmonella typhimurium TA100 was selected as a model microbial system with which to investigate further the impact of C60 aggregates on microbial growth, mutagenicity, and global transcript expression. Aggregates of C60 predominantly less than 100 nm significantly impacted Salmonella growth at concentrations of ≥0.5 mg/L. In addition, C60 aggregates also displayed mutagenic potential at concentrations ≥0.1 mg/L. Transcript expression analysis of S. typhimurium TA100 exposed to C60 for 24 h indicated that 271 transcripts had significant differential expression relative to controls with twofold or more change. Of particular interest was the increased expression of transcripts coding for proteins involved in energy metabolism, amino acid biosynthesis, transcription, and DNA metabolism, and the decreased expression of transcripts coding for proteins involved in protein fate, transport, and binding and bacterial secretion systems. Collectively, these data indicate that C60 interacts with the outer membrane of S. typhimurium TA100, resulting in delayed growth and mutagenicity, most likely by interfering with key transport functions and inducing a stress response, respectively. Environ. Toxicol. Chem. 2012; 31: 1438–1444. © 2012 SETAC
Effects of chronic copper exposure on development and survival in the southern leopard frog (Lithobates [Rana] sphenocephalus)
Authors: Lance Stacey L. , Erickson Matthew R. , Flynn R. Wesley , Mills Gary L. , Tuberville Tracey D. , Scott David E. 
Published: April 2012

Abstract
Exposure to environmental contaminants contributes to the global decline of amphibian populations. The impacts of organic contaminants on amphibians are well documented. However, substantially less is known concerning the potential effects of metals on amphibian populations. Copper (Cu) is an essential element, but it can be toxic at concentrations only slightly higher than the normal physiological range. The present study examines the effects of chronic Cu exposure on embryos and larvae of southern leopard frogs, Lithobates (Rana) sphenocephalus. Groups of eggs from multiple clutches were collected from two wetlands and exposed to a range of Cu concentrations (0–150 µg/L) until they reached the free-swimming stage, and then individual larvae were reared to metamorphosis. Higher Cu concentrations significantly reduced embryo survival to the free-swimming stage but did not further reduce survival to metamorphosis. Larval period was affected by Cu treatment, but the clutch from which larvae originated (i.e., parentage) explained a higher proportion of the variation. Embryo survival to hatching varied significantly among clutches, ranging from 42.9 to 79.2%. Measurable levels of Cu were found in larvae with body burdens up to 595 µg Cu/g dry mass in the 100 µg/L treatment, and larval Cu body burdens were higher than in metamorphs. The present study also demonstrated that higher initial egg density ameliorated embryo mortality at higher Cu levels and should be accounted for in future studies. Environ. Toxicol. Chem. 2012; 31: 1587–1594. © 2012 SETAC
A novel multidimensional solution reconstruction and edge‐based limiting procedure for unstructured cell‐centered finite volumes with application to shallow water dynamics
Authors: Delis A. I. , Nikolos I. K. 
Published: April 2012

SUMMARYOn unstructured meshes, the cell‐centered finite volume (CCFV) formulation, where the finite control volumes are the mesh elements themselves, is probably the most used formulation for numerically solving the two‐dimensional nonlinear shallow water equations and hyperbolic conservation laws in general. Within this CCFV framework, second‐order spatial accuracy is achieved with a Monotone Upstream‐centered Schemes for Conservation Laws‐type (MUSCL) linear reconstruction technique, where a novel edge‐based multidimensional limiting procedure is derived for the control of the total variation of the reconstructed field. To this end, a relatively simple, but very effective modification to a reconstruction procedure for CCFV schemes, is introduced, which takes into account geometrical characteristics of computational triangular meshes. The proposed strategy is shown not to suffer from loss of accuracy on grids with poor connectivity. We apply this reconstruction in the development of a second‐order well‐balanced Godunov‐type scheme for the simulation of unsteady two‐dimensional flows over arbitrary topography with wetting and drying on triangular meshes. Although the proposed limited reconstruction is independent from the Riemann solver used, the well‐known approximate Riemann solver of Roe is utilized to compute the numerical fluxes, whereas the Green–Gauss divergence formulation for gradient computations is implemented. Two different stencils for the Green–Gauss gradient computations are implemented and critically tested, in conjunction with the proposed limiting strategy, on various grid types, for smooth and nonsmooth flow conditions. Copyright © 2012 John Wiley & Sons, Ltd.
An empirical method for approximating canopy throughfall
Authors: Trinh Dieu Huong , Chui Ting Fong May 
Published: April 2012

AbstractRainfall replenishes surface and subsurface water but is partially intercepted by a canopy. However, it is challenging to quantify the rainfall passing through the canopy (i.e. throughfall). This study derives simple‐to‐use empirical equations relating throughfall to canopy and rainfall characteristics. Monthly throughfall is calculated by applying a mass balance model on weather data from Singapore; Vancouver, Canada; and Stanford, USA. Regression analysis is then performed on the calculated throughfall with three dependent variables (i.e. maximum canopy storage, average rainfall depth and time interval between two consecutive rainfall in a month) to derive the empirical equations. One local equation is derived for each location using data from that particular location, and one global equation is derived using data from all three locations. The equations are further verified with calculated monthly throughfall from other weather data and actual throughfall field measurements, giving an accuracy of about 80–90%. The global equation is relatively less accurate but is applicable worldwide. Overall, this study provides a global equation through which one can quickly estimate throughfall with only information on the three variables. When additional weather data are available, one can follow the proposed methodology to derive their own equations for better estimates. Copyright © 2012 John Wiley & Sons, Ltd.
Modelling of hydrogeochemical potential of three lake catchments in Polesie region (Eastern Poland)
Authors: Dawidek Jarosław , Ferencz Beata , Sobolewski Wojciech 
Published: April 2012

AbstractTotal dissolved solids (TDS) in lake and catchment water is a result of geological structure, as well as duration of rock and water contact and human activity. In this paper, a potential dissolved solids (PtDS) in three Łęczna–Włodawa Lake catchments was determined using extraction and computer software (GIS and AquaChem). Human pressure on water quality was estimated as a difference of the TDS and a catchment hydrogeochemical potential (TPtDS, total potential dissolved solids). TPtDS coefficient included hydrogeological features of the aquifer, soil cover impact on infiltrated water quality, and sediments susceptibility to denudation. The main advantage of the model is a possibility of its employment for every catchment or other areas (e.g. administrative) on both microscale and mesoscale. The highest TPtDS occurred in the catchment, favoured with underground supply, which was located in the vicinity of the Cretaceous mesoregional unit (Chełm Hills). The lowest value was observed in the catchment built with organogenic sediments and coarse material. A seasonal constancy of TPtDS values proved a stability of the lake‐catchment systems under study. Copyright © 2012 John Wiley & Sons, Ltd.
Multi‐site evaluation of hydrology component of SWAT in the coastal plain of southwest Georgia
Authors: Cho Jaepil , Bosch David , Vellidis George , Lowrance Richard , Strickland Timothy 
Published: April 2012

AbstractSimulation of watershed scale hydrologic and water quality processes is important for watershed assessments. Proper characterization of the accuracy of these simulations, particularly in cases with limited observed data, is critical. The Soil & Water Assessment Tool (SWAT) is frequently used for watershed scale simulation. The accuracy of the model was assessed by extrapolating calibration results from a well studied Coastal Plain watershed in Southwest Georgia, USA, to watersheds within the same geographic region without further calibration. SWAT was calibrated and validated on a 16.7‐km2 subwatershed within the Little River Experimental Watershed by varying six model parameters. The optimized parameter set was then applied to a watershed of similar land use and soils, a smaller watershed with different land use and soils and three larger watersheds within the same drainage system without further calibration. Simulation results with percent bias (PB) ±15% ≤ PB < ±25% and Nash–Sutcliffe efficiency (NSE) 0.50 < NSE ≤ 0.65 were considered to be satisfactory, whereas those with PB < ±10% and 0.75 < NSE ≤ 1.00 were considered very good. With these criteria, simulation results for the five non‐calibration watersheds were satisfactory to very good. Differences across watersheds were attributed to differences in soils, land use, and surficial aquifer characteristics. These results indicate that SWAT can be a useful tool for predicting streamflow for ungauged watersheds with similar physical characteristics to the calibration watershed studied here and provide an indication of the accuracy of hydrologic simulations for ungauged watersheds. Copyright © 2012 John Wiley & Sons, Ltd.
Neural invasion induces cachexia via astrocytic activation of neural route in pancreatic cancer
Authors: Imoto Akira , Mitsunaga Shuichi , Inagaki Masatoshi , Aoyagi Kazuhiko , Sasaki Hiroki , Ikeda Masafumi , Nakachi Kohei , Higuchi Kazuhide , Ochiai Atsushi 
Published: April 2012

AbstractPancreatic cancer is characterized by a high frequency of cachexia, pain and neural invasion (N‐inv). Neural damage is occurred by N‐inv and modulates pain and muscle atrophy via the activation of astrocyte in the connected spine. The activated astrocyte by N‐inv, thus, may affect cachexia in pancreatic cancer. Clinical studies in patients and autopsy cases with pancreatic cancer have revealed that N‐inv is related to cachexia and astrocytic activation. We established a novel murine model of cancer cachexia using N‐inv of human pancreatic cancer cells. Mice with N‐inv showed a loss of body weight, skeletal muscle and fat mass without appetite loss, which are compatible with an animal model of cancer cachexia. Activation of astrocytes in the spinal cord connected with N‐inv was observed in our model. Experimental cachexia was suppressed by disrupting neural routes or inhibiting the activation of astrocytes. These data provide the first evidence that N‐inv induces cachexia via astrocytic activation of neural route in pancreatic cancer.
Combinatorial treatment of mammospheres with trastuzumab and salinomycin efficiently targets HER2‐positive cancer cells and cancer stem cells
Authors: Oak Prajakta S. , Kopp Florian , Thakur Chitra , Ellwart Joachim W. , Rapp Ulf R. , Ullrich Axel , Wagner Ernst , Knyazev Pjotr , Roidl Andreas 
Published: April 2012

AbstractA major obstacle in the successful treatment of cancer is the occurrence of chemoresistance. Cancer cells surviving chemotherapy and giving rise to a recurrence of the tumor are termed cancer stem cells and can be identified by elevated levels of certain stem cell markers. Eradication of this cell population is a priority objective in cancer therapy. Here, we report elevated levels of stem cell markers in MCF‐7 mammospheres. Likewise, an upregulation of HER2 and its differential expression within individual cells of mammospheres was observed. Sorting for HER2high and HER2low cells revealed an upregulation of stem cell markers NANOG, OCT4 and SOX2 in the HER2low cell fraction. Accordingly, HER2low cells also showed reduced proliferation, ductal‐like outgrowths and an increased number of colonies in matrigel. Xenografts from subcutaneously injected HER2low sorted cells exihibited earlier onset but slower growth of tumors and an increase in stem cell markers compared to tumors developed from the HER2high fraction. Treatment of mammospheres with salinomycin reduced the expression of SOX2 indicating a selective targeting of cancer stem cells. Trastuzumab however, did not reduce the expression of SOX2 in mammospheres. Furthermore, a combinatorial treatment of mammospheres with trastuzumab and salinomycin was superior to single treatment with each drug. Thus, targeting HER2 expressing tumors with anti‐HER2 therapies will not necessarily eliminate cancer stem cells and may lead to a more aggressive cancer cell phenotype. Our study demonstrates efficient killing of both HER2 positive cells and cancer stem cells, hence opening a possibility for a new combinatorial treatment strategy.
Modest increase in risk of specific types of cancer types in type 2 diabetes mellitus patients
Authors: Lo Sui‐Foon , Chang Shih‐Ni , Muo Chih‐Hsin , Chen Shih‐Yin , Liao Fang‐Yin , Dee Shu‐Wei , Chen Pei‐Chun , Sung Fung‐Chang 
Published: April 2012

AbstractMost studies associated diabetes mellitus (DM) with risk of cancer have focused on the Caucasian population and only a few types of cancer. Therefore, a large and comprehensive nationwide retrospective cohort study involving an Asian population was conducted to evaluate the risk of several major types of cancer among Type 2 DM patients. The study analyzed the nationwide population‐based database from 1996 to 2009 released by the National Health Research Institute in Taiwan. Incidence and hazard ratios (HRs) were calculated for specific types of cancer. The overall risk of cancers was significantly greater in the DM cohort [N = 895,434; HR = 1.19, 95% confidence interval (CI) = 1.17–1.20], compared with non‐DM controls (N = 895,434). Several organs in the digestive and urogenital systems showed increased risk of cancer. The three highest HRs were obtained from cancers of the liver (HR = 1.78, 95% CI = 1.73–1.84), pancreatic (HR = 1.52, 95% CI = 1.40–1.65), and uterus and corpus (HR = 1.38, 95% CI = 1.22–1.55). The risk increased with age, and men with DM aged ≥75 years exhibited the highest risk (HR = 7.76, 95% CI = 7.39–8.15). Subjects with DM in this population have a modest increased risk of cancer, similar to the Caucasian population for several specific types of cancer. Old men with DM have the highest risk of cancer. Careful screening for cancer in DM patients is important for early diagnosis and effective treatment.
Three‐dimensional vascularization of electrospun PCL/collagen‐blend nanofibrous scaffoldsin vivo
Authors: Klumpp Dorothee , Rudisile Markus , Kühnle Romina I. , Hess Andreas , Bitto Franz F. , Arkudas Andreas , Bleiziffer Oliver , Boos Anja M. , Kneser Ulrich , Horch Raymund E. , Beier Justus P. 
Published: April 2012

AbstractNanofiber scaffolds have proven their various advantages for tissue engineering and have been analyzed extensively. However, to date the three‐dimensional pattern of vascularization inside nanofibrous scaffolds is unknown. This study introduces a novel method to visualize and quantify vascularization of electrospun nanofibrous PCL/collagen scaffolds in 3Din vivo. Randomly spun PCL/collagen blend and parallel aligned PCL/collagen blend/PEO scaffolds were analyzed for numbers and patterns of sprouting vessels inside the constructs using microCT scans at different time points. The image data derived from the microCT scans was converted into three‐dimensional vessel trees. The aligned scaffold showed a significantly smaller number of sprouting vessels but vascularization in the center of the constructs occurred considerably earlier than in the nonwoven scaffold. Thus, for the first time the actual pattern of vascularization in nanofibrous scaffolds can be visualized three‐dimensionally. These results demonstrate that the 3D pattern of vessel trees could be an essential parameter to evaluate nanofiber scaffolds for their suitability for tissue engineering as well asin vivoapplications in general. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 100A: 2302–2311, 2012.
Aerobic Swimming Performance of Juvenile Largemouth Bronze Gudgeon (Coreius guichenoti) in the Yangtze River
Authors: TU ZHIYING , LI LIPING , YUAN XI , HUANG YINGPING , JOHNSON DAVID 
Published: April 2012

ABSTRACTLargemouth bronze gudgeon (Coreius guichenoti), a fish species once abundant in the Yangtze River, has been rapidly declining in recent years. One important factor, among many, is the interruption of the free‐flowing rivers by dams. To obtain data that can be applied to the design of an effective fishway for C. guichenoti and other species in the fish community, a laboratory study of juvenile C. guichenoti's swimming ability and energetics was conducted in a flume‐type respirometer equipped with a high‐speed video camera system to record swimming behavior. The critical swimming speed (Ucrit), standard metabolic rate (SMR), and maximum metabolic rate (MO2,max) were determined during steady swimming at four water temperatures (10, 15, 20, and 25°C). A power function accurately describes the relationship between oxygen consumption rate (MO2) and swimming speed (U) at the four temperatures. The Ucrit, SMR, MO2,max, and metabolic scope increased with increasing temperature. The relationship between cost of transport (COT) and U was characteristically inverse bell‐shaped, with minimum COT at Uopt = 4.5–5.0 body lengths per second (bl sec−1). This investigation provides data on the swimming ability of C. guichenoti that will add to the basic science required for fishway design. J. Exp. Zool.317:294–302, 2012. © 2012 Wiley Periodicals, Inc.
Creativity, Problem Solving, and Solution Set Sightedness: Radically Reformulating BVSR
Authors: Simonton Dean Keith 
Published: April 2012

AbstractToo often, psychological debates become polarized into dichotomous positions. Such polarization may have occurred with respect to Campbell's (1960) blind variation and selective retention (BVSR) theory of creativity. To resolve this unnecessary controversy, BVSR was radically reformulated with respect to creative problem solving. The reformulation began by defining (a) potential solution sets consisting of k possible solutions each described by their respective probability and utility values, (b) a set sightedness metric that gauges the extent to which the probabilities correspond to the utilities, and (c) a solution creativity index based on the joint improbability and utility of each solution. These definitions are then applied to representative cases in which simultaneous or sequential generate‐and‐test procedures scrutinize solution sets of variable size and with representative patterns of probabilities and utilities. The principal features of BVSR theory were then derived, including the implications of superfluity and backtracking. Critically, it was formally demonstrated that the most creative solutions must emerge from solution sets that score extremely low in sightedness. Although this preliminary revision has ample room for further development, the demonstration proves that BVSR's explanatory value does not depend on any specious association with Darwin's theory of evolution.