bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the effect of preferential sampling in spatial prediction
Authors: Gelfand Alan E. , Sahu Sujit K. , Holland David M. 
Published: October 2012

The choice of the sampling locations in a spatial network is often guided by practical demands. In particular, many locations are preferentially chosen to capture high values of a response, for example, air pollution levels in environmental monitoring. Then, model estimation and prediction of the exposure surface become biased because of the selective sampling. As prediction is often the main utility of the modeling, we suggest that the effect of preferential sampling lies more importantly in the resulting predictive surface than in parameter estimation. We take demonstration of this effect as our focus.In particular, our contribution is to offer a direct simulation‐based approach to assessing the effects of preferential sampling. We compare two predictive surfaces over the study region, one originating from the notion of an “operating” intensity, driving the selection of monitoring sites, the other under complete spatial randomness. We can consider a range of response models. They may reflect the operating intensity, introduce alternative informative covariates, or just propose a flexible spatial model. Then, we can generate data under the given model. Upon fitting the model and interpolating (kriging), we will obtain two predictive surfaces to compare with the known truth. It is important to note that we need suitable metrics to compare the surfaces and that the predictive surfaces are random, so we need to make expected comparisons. We also present an examination of real data using ozone exposures. Here, what we can show is that, within a given network, there can be substantial differences in the spatial prediction using preferentially chosen locations versus roughly randomly selected locations and that the latter provide much improved predictive validation. Copyright © 2012 John Wiley & Sons, Ltd.
Erosive water level regime and climatic variability forcing of beach–dune systems on south‐western Vancouver Island, British Columbia, Canada
Authors: Heathfield Derek K. , Walker Ian J. , Atkinson David E. 
Published: October 2012

ABSTRACTIncreases in the frequency and magnitude of extreme water levels and storm surges are correlated with known indices of climatic variability (CV), including the El Niño Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO), along some areas of the British Columbia coast. Since a shift to a positive PDO regime in 1977, the effects of ENSO events have been more frequent, persistent, and intense. Teleconnected impacts include more frequent storms, higher surges, and enhanced coastal erosion. The response of oceanographic forcing mechanisms (i.e. tide, surge, wave height, wave period) to CV events and their role in coastal erosion remain unclear, particularly in western Canada. As a first step in exploring the interactions between ocean–atmosphere forcing and beach–dune responses, this paper assembles the historic erosive total water level (TWL) regime and explores relations with observed high magnitude storms that have occurred in the Tofino‐Ucluelet region (Wickaninnish Bay) on the west coast of Vancouver Island, British Columbia, Canada. Extreme events where TWL exceeded an erosional threshold (i.e. elevation of the beach–foredune junction) of 5·5 m aCD are examined to identify dominant forcing mechanisms and to classify a regime that describes erosive events driven principally by wave conditions (61·5%), followed by surge (21·8%), and tidal (16·7%) effects. Furthermore, teleconnections between regional CV phenomena, extreme storm events and, by association, coastal erosion, are explored. Despite regional sea level rise (eustatic and steric), rapid crustal uplift rates have resulted in a falling relative sea level and, in some sedimentary systems, shoreline progradation at rates approaching +1·5 m a–1 over recent decades. Foredune erosion occurs locally with a recurrence interval of approximately 1·53 years followed by rapid rebuilding due to high onshore sand supply and often in the presence of large woody debris and rapidly colonizing vegetation in the backshore. Copyright © 2012 John Wiley & Sons, Ltd.
Kinematics of active earthflows revealed by digital image correlation and DEM subtraction techniques applied to multi‐temporal LiDAR data
Authors: Daehne Alexander , Corsini Alessandro 
Published: October 2012

ABSTRACTEarthflow‐type landslides are persistent natural hazards having deep socio‐economic and environmental consequences. They have significantly contributed to the geomorphic evolution of mountainous slopes in Europe since the Late Glacial. An understanding of their complex kinematics is crucial to better constrain the processes governing their occurrence and mobility.In this work we explored the possibility to quantify displacement vectors on a spatially distributed basis and to quantify volumetric transfer at the slope scale with regard to a large flow‐type landslide located in the northern Apennines of Italy. For this purpose we applied digital image correlation (DIC) and digital elevation model differencing (DEMoD) techniques to multi‐temporal airborne LiDAR surveys of 2006, 2007 and 2009.The DIC was applied to greyscale slope gradient maps retrieved after precise co‐registration of LiDAR surveys. Thereby, movement patterns over various sectors of the landslide were reconstructed and quantified, most notably up to 20 m in the head zone, up to 51 m in the lower main track, and up to about 27 m at the landslide toe. The DEMoD analysis revealed significant mass transfer from the source to the tracks and toe zone, with the upper flow tracks acting as temporal storage of large amounts of material. The mass balance indicated that significant amounts of advancing landslide debris were eroded by a local stream. An integrated analysis of DEMoD and DIC results allowed for a discussion of governing processes, such as the transition from slide to flow, the influence of underlying topography on earthflow mobility, and the role of undrained loading as a mechanism of toe zone reactivation.In conclusion, the successful application of DIC and DEMoD to the case study underlines the added value of high‐resolution DEMs in the analysis of earthflow kinematics toward a better understanding of their role in the geomorphic evolution of slopes. Copyright © 2012 John Wiley & Sons, Ltd.
Rapid estimation of nuclear magnetic resonance experiment time in low-concentration environmental samples
Authors: Masoom Hussain , Courtier-Murias Denis , Farooq Hashim , Soong Ronald , Simpson Myrna J. , Maas Werner , Kumar Rajeev , Monette Martine , Stronks Henry , Simpson André J. 
Published: October 2012

Abstract
Nuclear magnetic resonance (NMR) spectroscopy is an essential tool for studying environmental samples but is often hindered by low sensitivity, especially for the direct detection of nuclei such as13C. In very heterogeneous samples with NMR nuclei at low abundance, such as soils, sediments, and air particulates, it can take days to acquire a conventional13C spectrum. The present study describes a prescreening method that permits the rapid prediction of experimental run time in natural samples. The approach focuses the NMR chemical shift dispersion into a single spike, and, even in samples with extremely low carbon content, the spike can be observed in two to three minutes, or less. The intensity of the spike is directly proportional to the total concentration of nuclei of interest in the sample. Consequently, the spike intensity can be used as a powerful prescreening method that answers two key questions: (1) Will this sample produce a conventional NMR spectrum? (2) How much instrument time is required to record a spectrum with a specific signal-to-noise (S/N) ratio? The approach identifies samples to avoid (or pretreat) and permits additional NMR experiments to be performed on samples producing high-quality NMR data. Applications in solid- and liquid-state13C NMR are demonstrated, and it is shown that the technique is applicable to a range of nuclei. Environ. Toxicol. Chem. 2013;32:129–136. © 2012 SETAC
A gas‐kinetic scheme for the modified Baer–Nunziato model of compressible two‐phase flow
Authors: Pan L. , Zhao G. P. , Wang S. H. 
Published: October 2012

SUMMARYNumerical methods for the Baer–Nunziato model of compressible two‐phase flow have attracted much attention in recent years. In this paper, a two‐phase Bhatnagar–Gross–Krook (BGK) model is constructed in which the non‐conservative terms in the Baer–Nunziato model are considered as the external forces and the collisions both with particles of their phases and other phases are taken into consideration. On the basis of this BGK model, the so‐called modified Baer–Nunziato model is derived and a gas‐kinetic scheme for this modified model is presented. The distribution functions are constructed at the cell interface based on the integral solutions of the BGK equations for both phases. Then, numerical fluxes can be obtained by taking moments of the distribution functions, and non‐conservative terms are explicitly introduced into the construction of numerical fluxes. In this method, not only the iterative processes in the exact Riemann solvers are eliminated but also the collisions with the particles of other phases are taken into account. Copyright © 2012 John Wiley & Sons, Ltd.
Endogenous transforming growth factor‐beta promotes quiescence of primary microglia in vitro
Authors: Spittau Björn , Wullkopf Lena , Zhou Xiaolai , Rilka Jennifer , Pfeifer Dietmar , Krieglstein Kerstin 
Published: October 2012

AbstractMicroglia are the immune cells of the central nervous system (CNS) and play important roles under physiological and pathophysiological conditions. Activation of microglia has been reported for a variety of CNS diseases and is believed to be involved in inflammation‐mediated neurodegeneration. Loss of TGFβ1 results in increased microgliosis and neurodegeneration in mice which indicates that TGFβ1 is an important regulator of microglial functions in vivo. Here, we addressed the role of endogenous TGFβ signaling for microglia in vitro. We clearly demonstrate active TGFβ signaling in primary microglia and further introduce Klf10 as a new TGFβ target gene in microglia. Moreover, we provide evidence that microglia express and release TGFβ1 that acts in an autocrine manner to activate microglial TGFβ/Smad signaling in vitro. Using microarrays, we identified TGFβ‐regulated genes in microglia that are involved in TGFβ1 processing, its extracellular storage as well as activation of latent TGFβ. Finally, we demonstrate that pharmacological inhibition of microglial TGFβ signaling resulted in upregulation of the proinflammatory markers IL6 and iNOS and downregulation of the alternative activation markers Arg1 and Ym1 in vitro. Together, these data clearly show that endogenous TGFβ1 and autocrine TGFβ signaling is important for microglial quiescence in vitro and further suggest the upregulation of TGFβ1 in neurodegenerative diseases as a mechanism to regulate microglia functions and silence neuroinflammation. © 2012 Wiley Periodicals, Inc.
Changing Northern catchments: Is altered hydrology, temperature or both going to shape future stream communities and ecosystem processes?
Authors: Friberg Nikolai , Bergfur Jenny , Rasmussen Jes , Sandin Leonard 
Published: October 2012

AbstractGlobal change is predicted to increase temperature substantially in the North as well as altering run‐off regimes with less synchronicity as the importance of snow melt declines. River biota and ecosystem processes will be influenced across all levels of organization, both in concert and individually. It is of vital importance that the impacts, and their likely magnitude, can be identified in order to deploy suitable adaptation strategies at the catchment scale. In this paper, we re‐analyse four data sets from studies conducted in Greenland (66–69oN), Iceland (64oN), Sweden (60oN) and Denmark (55–57oN) to try and tease out the likely impacts of water temperature and hydrology in shaping the stream communities and ecosystem processes in high‐latitude catchments. Water temperature was the environmental variable that best explained macroinvertebrate community composition across latitudes. In contrast, no significant relationship between macroinvertebrate community composition and measures of hydraulic stability (or nutrients) was found. We found a strong linear relationship between decay rate of leaf litter and water temperature (r2 = 0.68; p < 0.0001) independent of latitudes. Our study suggests that temperature could be the primary driver of ecosystem change in future with northern catchments likely to be especially vulnerable. Copyright © 2012 John Wiley & Sons, Ltd.
Spinal 5‐HT3 receptors facilitate behavioural hypersensitivity induced by elevated calcium channel alpha‐2‐delta‐1 protein
Authors: Chang E.Y. , Chen X. , Sandhu A. , Li C‐Y. , Luo Z.D. 
Published: October 2012

AbstractBackgroundPeripheral nerve injury induces up‐regulation of the calcium channel alpha‐2‐delta‐1 proteins in the dorsal root ganglia and dorsal spinal cord that correlates with neuropathic pain development. Similar behavioural hypersensitivity was also observed in injury‐free transgenic (TG) mice over‐expressing the alpha‐2‐delta‐1 proteins in neuronal tissues. To investigate pathways regulating alpha‐2‐delta‐1 protein‐mediated behavioural hypersensitivity, we examined whether spinal serotonergic 5‐HT3 receptors are involved similarly in the modulation of behavioural hypersensitivity induced by either peripheral nerve injury in a nerve injury model or neuronal alpha‐2‐delta‐1 over‐expression in the TG model.MethodsThe effects of blocking behavioural hypersensitivity in these two models by intrathecal or systemic injections of 5‐HT3 receptor antagonist, ondansetron, were compared.ResultsOur data indicated that the TG mice displayed similar behavioural hypersensitivities to non‐painful mechanical stimulation (tactile allodynia) and painful thermal stimulation (thermal hyperalgesia) as that observed in the nerve injury model. Interestingly, tactile allodynia and thermal hyperalgesia in both models can be blocked similarly by intrathecal, but not systemic, injection of ondansetron.ConclusionsOur data suggest that spinal 5‐HT3 receptors are likely to play a role in alpha‐2‐delta‐1‐mediated behavioural hypersensitivities through a descending serotonergic facilitation.
Protective effect of curcumin against formaldehyde‐induced genotoxicity in A549 Cell Lines
Authors: Zhang Ben‐Yan , Shi Yu‐Qin , Chen Xin , Dai Juan , Jiang Zhong‐Fa , Li Ning , Zhang Zhi‐Bing 
Published: October 2012

ABSTRACTFormaldehyde is ubiquitous in the environment. It is known to be a genotoxic substance. We hypothesized that reactive oxygen species (ROS) and lipid peroxidation are involved in formaldehyde‐induced genotoxicity in human lung cancer cell lines A549. To test this hypothesis, we investigated the effects of antioxidant on formaldehyde‐induced genotoxicity in A549 Cell Lines. Formaldehyde exposure caused induction of DNA–protein cross‐links (DPCs). Curcumin is an important antioxidant. Formaldehyde significantly increased malondialdehyde (MDA) levels, and decreased superoxide dismutase (SOD) and glutathione peroxidase (GSH‐Px) activity. In addition, the activation of NF‐κB and AP‐1 were induced by formaldehyde treatment. Pretreatment with curcumin counteracted formaldehyde‐induced oxidative stress, ameliorated DPCs and attenuated activation of NF‐κB and AP‐1 in A549 Cell Lines. These results, taken together, suggest that formaldehyde induced genotoxicity through its ROS and lipid peroxidase activity and caused DPCs effects in A549 cells. Copyright © 2012 John Wiley & Sons, Ltd.
Mollugin inhibits proliferation and induces apoptosis by suppressing fatty acid synthase in HER2‐overexpressing cancer cells
Authors: Do Minh Truong , Hwang Yong Pil , Kim Hyung Gyun , Na MinKyun , Jeong Hye Gwang 
Published: October 2012

AbstractMollugin is a naphthohydroquine found in the roots of Rubia cordifolia, and has been reported to have a variety of biological activities, including anti‐inflammatory and apoptotic effects. In the present study, we investigated the molecular mechanisms by which mollugin exerts anti‐tumor effect in HER2‐overexpressing cancer cells. Our results showed that mollugin exhibited potent inhibitory effects on cancer cell proliferation, especially in HER2‐overexpressing SK‐BR‐3 human breast cancer cells and SK‐OV‐3 human ovarian cancer cells in a dose‐ and time‐dependent manner without affecting immortalized normal mammary epithelial cell line MCF‐10A. Furthermore, we found that a blockade of Akt/SREBP‐1c signaling through mollugin treatment significantly reduced FAS expression and subsequently suppressed cell proliferation and induced apoptosis in HER2‐overexpressing cancer cells. Mollugin treatment caused a dose‐dependent inhibition of HER2 gene expression at the transcriptional level, potentially in part through suppression of NF‐κB activation. The combination of mollugin with a MEK1/2 inhibitor may be required in order to achieve optimal efficacy in HER2‐overexpressing cancers. These data provide evidence that mollugin inhibits proliferation and induces apoptosis in HER2‐overexpressing cancer cells by blocking expression of the FAS gene through modulation of a HER2/Akt/SREBP‐1c signaling pathway. Our findings suggest that mollugin is a novel modulator of the HER2 pathway in HER2‐overexpressing cancer cells with a potential role in the treatment and prevention of human breast and ovarian cancer with HER2 overexpression. J. Cell. Physiol. © 2012 Wiley Periodicals, Inc.
Azithromycin suppresses human osteoclast formation and activity in vitro
Authors: Gannon Siobhan C. , Cantley Melissa D. , Haynes David R. , Hirsch Robert , Bartold P. Mark 
Published: October 2012

AbstractAzithromycin is an antibiotic with anti‐inflammatory properties used as an adjunct to treat periodontitis, a common inflammatory mediated condition featuring pathologic alveolar bone resorption. This study aimed to determine the effect of azithromycin on human osteoclast formation and resorptive activity in vitro. Osteoclasts were generated from peripheral blood mononuclear cells stimulated with macrophage colony stimulating factor (M‐CSF) and receptor activator of nuclear factor kappa B (RANK) ligand. The effects of azithromycin at concentrations ranging from 0.5 to 40 µg/ml were tested. Osteoclast formation and activity, acidification, actin ring formation and expression of mRNA, and protein encoding for key osteoclast genes were assessed. The results demonstrated that azithromycin reduced osteoclast resorptive activity at all concentrations tested with osteoclast formation being significantly reduced at the higher concentrations (20 and 40 µg/ml). mRNA and protein expression of key osteoclast transcription factor Nuclear Factor of Activated T cells (NFATc1) was significantly reduced by azithromycin at later stages of osteoclast development (day 17). Azithromycin also reduced tumor necrosis factor receptor associated factor‐6 (TRAF6) mRNA expression at day 14, and cathepsin K mRNA expression at days 14 and 17. Integrin β3 and MMP‐9 mRNA expression was reduced by azithromycin at day 17 in osteoclasts cultured on dentine. The osteoclast proton pump did not appear to be affected by azithromycin, however formation of the actin ring cytoskeleton was inhibited. This study demonstrates that azithromycin inhibits human osteoclast function in vitro, which may account for at least some of the beneficial clinical effects observed with azithromycin treatment in periodontitis. J. Cell. Physiol. © 2012 Wiley Periodicals, Inc.
Tumor associated macrophages and neutrophils in tumor progression
Authors: Galdiero Maria R. , Garlanda Cecilia , Jaillon Sébastien , Marone Gianni , Mantovani Alberto 
Published: October 2012

AbstractTumor‐associated macrophages (TAMs) are a key component of the tumor microenvironment and orchestrate various aspects of cancer. Diversity and plasticity are hallmarks of cells of the monocyte–macrophage lineage. In response to distinct signals macrophages undergo M1 (classical) or M2 (alternative) activation, which represent extremes of a continuum in a spectrum of activation states. Metabolic adaptation is a key component of macrophage plasticity and polarization, instrumental to their function in homeostasis, immunity and inflammation. Generally, TAMs acquire an M2‐like phenotype that plays important roles in many aspects of tumor growth and progression. There is now evidence that also neutrophils can be driven towards distinct phenotypes in response to microenvironmental signals. The identification of mechanisms and molecules associated with macrophage and neutrophil plasticity and polarized activation provides a basis for new diagnostic and therapeutic strategies. J. Cell. Physiol. 228: 1404–1412, 2013. © 2012 Wiley Periodicals, Inc.
Pregnane glycosides interfere with steroidogenic enzymes to down‐regulate corticosteroid production in human adrenocortical H295R cells
Authors: Komarnytsky Slavko , Esposito Debora , Poulev Alexander , Raskin Ilya 
Published: October 2012

AbstractA group of bioactive steroidal glycosides (pregnanes) with anorectic activity in animals was isolated from several genera of milkweeds including Hoodia and Asclepias. In this study, we investigated the effects, structure‐activity relationships, and mechanism of action of pregnane glycosides on steroidogenesis in human adrenocortical H295R cells. Administration of pregnane glycosides for 24 h suppressed the basal and forskolin‐stimulated release of androstenedione, corticosterone, and cortisone from H295R cells. The conversion of progesterone to 11‐deoxycorticosterone and 17‐hydroxyprogesterone to either androstenedione or 11‐deoxycortisol was most strongly affected, with 12‐cinnamoyl‐, benzoyl‐, and tigloyl‐containing pregnanes showing the highest activity. Incubation of pregnane glycosides for 24 h had no effect on mRNA transcripts of CYP11A1, CYP21A1, CYP11B1 cytochrome enzymes and steroidogenic acute regulatory protein (StaR) protein, yet resulted in twofold decrease in HSD3B1 mRNA levels. At the same time, pregnane glycosides had no effect on the CYP1, 2, or 3 drug and steroid metabolism enzymes and showed weak Na+/K+ ATPase and glucocorticoid receptor binding. Taken together, these data suggest that pregnane glycosides specifically suppress steroidogenesis through strong inhibition of 11β‐hydroxylase and steroid 17‐alpha‐monooxygenase, and weak inhibition of cytochrome P450 side chain cleavage enzyme and 21β‐hydroxylase, but not 3β‐hydroxysteroid dehydrogenase/isomerase. J. Cell. Physiol. © 2013 Wiley Periodicals, Inc.