bluuebunny/crossref_metadata_2025 huggingface dataset:
A regional climate simulation over the Iberian Peninsula for the last millennium
Authors: Gómez-Navarro J. J. , Montávez J. P. , Jerez S. , Jiménez-Guerrero P. , Lorente-Plazas R. , González-Rouco J. F. , Zorita E.
Published: April 2011

Abstract. A high-resolution (30 km) regional paleoclimate simulation of the last millennium over the Iberian Peninsula (IP) is presented. The simulation was performed with a climate version of the mesoscale model MM5 driven by the global model ECHO-G. Both models were driven by the same reconstructions of several external forcing factors. The high spatial resolution of the regional model allows climatologists to realistically simulate many aspects of the climate in the IP, as compared to an observational data set in the reference period 1961–1990. Although the spatial-averaged values developed by the regional model are tightly driven by the boundary conditions, it is capable to develop a different realisation of the past climate at regional scales, especially in the high-frequency domain and for precipitation. This has to be considered when comparing the results of climate simulations versus proxy reconstructions. A preliminary comparison of the simulation results with reconstructions of temperature and precipitation over the IP shows good agreement in the warming trends in the last century of the simulation, although there are large disagreements in key periods such as the precipitation anomalies in the Maunder Minimum.
Sub-decadal- to decadal-scale climate cyclicity during the Holsteinian interglacial (MIS 11) evidenced in annually laminated sediments
Authors: Koutsodendris A. , Brauer A. , Pälike H. , Pross J. , Müller U. C. , Lotter A. F.
Published: April 2011

Abstract. To unravel the short-term climate variability during Marine Isotope Stage (MIS) 11, which represents a close analogue to the Holocene with regard to orbital boundary conditions, we performed microfacies and time series analyses on a ~3200-yr-long record of annually laminated Holsteinian lake sediments from Dethlingen, northern Germany. These biogenic varves comprise two sub-layers: A light layer, which is controlled by spring/summer diatom blooms, and a dark layer consisting mainly of amorphous organic matter and fragmented diatom frustules deposited during autumn/winter. Time series analyses were performed on the thickness of the light and dark layers. Signals exceeding the 95 % and 99 % confidence levels occur at periods that are near-identical to those known from modern instrumental data and Holocene palaeoclimatic records. Spectral peaks at periods of 90, 25, and 10.5 yr are likely associated with the 88-, 22- and 11-yr solar cycles, respectively. This variability is mainly expressed in the light layer spectra, suggesting solar influence on the palaeoproductivity of the lake. Significant signals at periods between 3 and 5 yr and at ~6 yr are strongest expressed in the dark layer spectra and may reflect an influence of the El Niño-Southern Oscillation (ENSO) and the North Atlantic Oscillation (NAO) during autumn/winter. Our results suggest that solar forcing and ENSO/NAO-like variability influenced central European climate during MIS 11 similar to the present interglacial, thus demonstrating the comparability of the two interglacial periods at sub-decadal to decadal timescales.
Effect of high-resolution spatial soil moisture variability on simulated runoff response using a distributed hydrologic model
Authors: Minet J. , Laloy E. , Lambot S. , Vanclooster M.
Published: April 2011

Abstract. The importance of spatial variability of antecedent soil moisture conditions on runoff response is widely acknowledged in hillslope hydrology. Using a distributed hydrologic model, this paper aims at investigating the effects of soil moisture spatial variability on runoff in various field conditions and at finding the structure of the soil moisture pattern that approaches the measured soil moisture pattern in terms of field scale runoff. High spatial resolution soil moisture was surveyed in ten different field campaigns using a proximal ground penetrating radar (GPR) mounted on a mobile platform. Based on these soil moisture measurements, seven scenarios of spatial structures of antecedent soil moisture were used and linked with a field scale distributed hydrological model to simulate field scale runoff. Accounting for spatial variability of soil moisture resulted in general in higher predicted field scale runoff as compared to the case where soil moisture was kept constant. The ranges of possible hydrographs were delineated by extreme scenarios where soil moisture was directly and inversely modelled according to the topographic wetness index (TWI). These behaviours could be explained by the sizes and locations of runoff contributing areas, knowing that runoff was generated by infiltration excess over a certain soil moisture threshold. The most efficient scenario for modelling the within field spatial structure of soil moisture appeared to be when soil moisture is directly arranged according to the TWI, especially when measured soil moisture and TWI were correlated. The novelty of this work is to benefit from a large set of high-resolution soil moisture measurements allowing to model effectively the within field distribution of soil moisture and its impact on the field scale hydrograph. These observations contributed to the current knowledge of the impact of antecedent soil moisture spatial variability on field scale runoff.
Wear Debris Stimulates Bone-Resorbing Factor Expression in the Fibroblasts and Osteoblasts
Authors: Fujii Jiro , Niida Shumpei , Yasunaga Yuji , Yamasaki Akira , Ochi Mitsuo
Published: April 2011

Wear debris is believed to cause periprosthetic osteolysis and loosening of total joint arthroplasties. We investigated the wear debris-mediated osteolysis in wild-type mice and macrophage-deficient Csf1op/Csf1op (op/op) mice using high density polyethylene (HDP) particles transplanted on the parietal bone surface. Four weeks after surgery, phagocytosis of the HDP particles by F4/80-positive macrophages and tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts was observed in the normal mice, but not in the macrophage-deficient op/op mice. These results suggest that macrophages are implicated in wear debris-dependent osteoclast formation. However, HDP particles were phagocytosed not only by macrophages but also by F4/80-negative cells in both genotypes of mice. Electron microscopic observation identified these cells as fibroblasts. Cell culture studies demonstrated that fibroblasts cultured with HDP-particles showed upregulation of interleukin-6 (IL-6) expression compared with non-treated fibroblasts. When we examined the gene expression of osteoblasts that belong to the mesenchymal cell lineage as fibroblasts, we found that the expression of not only IL-6 but also interleukin-1 beta (IL-1β), tumor necrosis factor-alpha (TNF-α) and cyclooxygenase2 (Cox2) were up-regulated by HDP particle-stimulation. These findings suggest the possibility that fibroblasts and osteoblasts are involved in wear debris-mediated osteolysis within the tissue surrounding artificial joints through the production of bone resorbing factors IL-6, IL-1β, TNF-α, and Cox2.
Circulating and progenitor endothelial cells are abnormal in patients with different types of von Willebrand disease and correlate with markers of angiogenesis
Authors: Gritti Giuseppe , Cortelezzi Agostino , Bucciarelli Paolo , Rezzonico Francesca , Lonati Silvia , La Marca Silvia , Silvestris Ilaria , Federici Augusto B.
Published: April 2011

von Willebrand disease (VWD) is the most common inherited bleeding disorder and is caused by quantitative or qualitative defects of von Willebrand factor (VWF). VWF, synthesized by endothelium and megakaryocytes (MK), circulates in plasma and is present in subendothelium and platelets. Circulating endothelial cells (CEC) and progenitor endothelial cells (EPC) have been recently proposed as markers of peripheral and bone marrow‐derived angiogenesis. To evaluate the association of CEC/EPC with known inherited defects of cellular and circulating VWF, we have measured the number of CEC/EPC together with cytokines involved in angiogenesis in different VWD types. A group of 74 patients was composed by the following VWD types: VWD1 (n = 22), VWD2A (n = 9), VWD2B (n = 19), VWD2M (n = 17), and VWD3 (n = 7). Healthy individuals (n = 20) were used as controls. CEC (CD146+, CD31+, and CD45−) and EPC (CD34+, CD133+, and CD45−) were evaluated by flow cytometry. Circulating serum levels of VEGF, E‐selectin, P‐selectin, EPO, and TPO were determined by ELISA. CEC, VEGF, E‐selectin, and EPO were higher and EPC lower in VWD patients than in controls (P < 0.01). Among the five groups of VWD patients and controls, a significant difference was found for CEC (one‐way ANOVA: P = 0.005), EPC (P = 0.001), E‐Selectin (P < 0.0001), EPO (P = 0.021), and TPO (P = 0.004): the latter was high in VWD3 patients. In VWD1, we found an inverse relationship between CEC and VWF:Ag levels (P = 0.048; R2 = 0.19). Based on these data, CEC are increased in VWD and are associated with the high levels of cytokines involved in angiogenesis (up‐regulation). EPC are decreased, suggesting down‐regulation of bone marrow‐derived angiogenesis in VWD. Am. J. Hematol. 2011. © 2011 Wiley‐Liss, Inc.
Oral, Direct Thrombin and Factor Xa Inhibitors: The Replacement for Warfarin, Leeches, and Pig Intestines?
Authors: Straub Alexander , Roehrig Susanne , Hillisch Alexander
Published: April 2011

To prevent thromboses after surgery, patients have until now had to inject themselves daily with heparin. For stroke prophylaxis in atrial fibrillation, patients take vitamin K antagonists of the coumarin type, which have a narrow therapeutic window and whose dosage must be regularly monitored. In order to improve the standard of therapy in thromboembolic diseases such as deep‐vein thrombosis, pulmonary embolism, and stroke in atrial fibrillation, intensive research has been carried out over the last decade in the search for new, orally active thrombin and factor Xa inhibitors. A number of these compounds are already on the market or are in advanced clinical development; they could revolutionize the anticoagulant market.
Two simple Shewhart‐type multivariate nonparametric control charts
Authors: Boone J. M. , Chakraborti S.
Published: April 2011

In many quality control applications, the necessary distributional assumptions to correctly apply the traditional parametric control charts are either not met or there is simply no enough information or evidence to verify the assumptions. It is well known that the performance of many parametric control charts can be seriously degraded in situations like this. Thus, control charts that do not require a specific distributional assumption to be valid, the so‐called nonparametric or distribution‐free charts, are desirable in practice. In this paper, two simple to use multivariate nonparametric control charts are considered. The charts are Shewhart‐type charts and are based on the multivariate forms of the sign and the Wilcoxon signed‐rank tests. The performance of the proposed charts is studied in a simulation study. Some observations and recommendations are made. Copyright © 2011 John Wiley & Sons, Ltd.
Sensitive high‐throughput screening for the detection of reducing sugars
Authors: Mellitzer Andrea , Glieder Anton , Weis Roland , Reisinger Christoph , Flicker Karlheinz
Published: April 2011

The exploitation of renewable resources for the production of biofuels relies on efficient processes for the enzymatic hydrolysis of lignocellulosic materials. The development of enzymes and strains for these processes requires reliable and fast activity‐based screening assays. Additionally, these assays are also required to operate on the microscale and on the high‐throughput level. Herein, we report the development of a highly sensitive reducing‐sugar assay in a 96‐well microplate screening format. The assay is based on the formation of osazones from reducing sugars and para‐hydroxybenzoic acid hydrazide. By using this sensitive assay, the enzyme loads and conversion times during lignocellulose hydrolysis can be reduced, thus allowing higher throughput. The assay is about five times more sensitive than the widely applied dinitrosalicylic acid based assay and can reliably detect reducing sugars down to 10 μM. The assay‐specific variation over one microplate was determined for three different lignocellulolytic enzymes and ranges from 2 to 8%. Furthermore, the assay was combined with a microscale cultivation procedure for the activity‐based screening of Pichia pastoris strains expressing functional Thermomyces lanuginosus xylanase A, Trichoderma reesei β‐mannanase, or T. reesei cellobiohydrolase 2.
Chemometrics in fuel science: demonstration of the feasibility of chemometrics analyses applied to physicochemical parameters to screen solvent tracers in Brazilian commercial gasoline
Authors: Tanaka Guilherme Tsuguio , de Oliveira Ferreira Fabrício , Ferreira da Silva Carlos Eduardo , Flumignan Danilo Luiz , de Oliveira José Eduardo
Published: April 2011

Samples of commercial gasoline, from the National Program of Fuel Quality Monitoring of the National Petroleum Agency, were collected from gas stations located in the Midwestern state of Sao Paulo, Brazil, and analyzed by several physicochemical standard methods established by ANP Resolution no. 309. Also, important information related to tampering was analyzed with the marker solvent. Statistical analysis and exploratory chemometric were employed to discriminate the presence of markers of solvents in commercial gasoline. The results showed that statistical and chemometric parameters such as atmospheric distillation temperatures T10 and T90, RON, benzene and saturated and aromatic hydrocarbons satisfactorily describe the presence of marker solvent, usually with a probability exceeding 70%. Furthermore, after optimizing the SIMCA algorithm, sensitivity in the training set with cross‐validation leave‐one‐out (83.8%) and the set of prediction (77.1%) were revealed. The proposed method will become indispensable and recommended for discriminating samples of fuels for commercial applications in routine monitoring programs and quality control. Copyright © 2011 John Wiley & Sons, Ltd.
Planning data transfers in grids: a multi‐service queueing approach
Authors: Munir Kashif , Cigno Renato Lo , Vicat‐Blanc Pascale Primet , Welzl Michael
Published: April 2011

Grid applications move large amounts of data between distributed resources, and the efficiency of a Grid depends on their timely delivery within given bounds (deadlines). In most cases, the data volume and deadline are known in advance, allowing for both network planning and connection admission control (textrmCAC). We formally define the problem and, based on this formalization, describe the operation of a feasible procedure for network reservations of deadline‐constrained bulk data transfer requests. The procedure guarantees a minimum bandwidth to meet the deadlines and allows for opportunistic utilization of residual network capacity. We propose a novel analytical model based on the solution of an M/M(nc)/1/k(s)−RPS queue. The analytical model is validated against ns−2 simulations taking into account network level details (IP and TCP protocols), showing remarkably good coherence even under heavy loads. The model is orders of magnitude faster than simulation, which enables its application to plan the capacity of Grid networks, and to enforce CAC under the hypothesis of a dominating bottleneck on the transfer route. Copyright © 2011 John Wiley & Sons, Ltd.
Automatic detection and high resolution fine structure analysis of conic X‐ray diffraction lines
Authors: Bauch J. , Henschel F. , Schulze M.
Published: April 2011

The presented method demonstrates a first step in the development of a high resolution “Residual stress microscope” and facilitates through the implementation of largely automated procedures a fast detection of diffraction lines in the form of conic sections. It has been implemented for, but is not exclusively used for the Kossel technique and the “X‐ray Rotation‐Tilt Method” (XRT). The resulting multifaceted evaluable data base of many X‐ray diffraction radiographies can be used not only for the systematic analysis of anomalies in diffraction lines (reflection fine structure), but also for direct calculation and output of precision residual stress tensors. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical and magnetic properties of (Zn,Mn)O nanostructures synthesized by CVD method
Authors: Sharma V. K. , Gupta B. K. , Varma G. D.
Published: April 2011

We report on microstructural, optical and magnetic properties of (Zn,Mn)O nanostructures synthesized by a chemical vapor deposition (CVD) technique. Average diameters of the as grown (Zn,Mn)O nanorods and nanowires were ∼400 nm and ∼50 nm, respectively. X‐ray diffraction (XRD) and photoluminescence (PL) spectra provided the evidence that Mn was incorporated into ZnO lattice. PL spectra of the (Zn,Mn)O nanostructures showed shift in near band edge (NBE) emission at 396 nm together with a green band (GB) emission at 510 nm and a blue band (BB) emission at 460 nm. Magnetic measurements revealed mixed magnetic phases (ferromagnetic and antiferromagnetic) in the (Zn,Mn)O nanostructures. Vapor‐solid‐solid (VSS) mechanism was thought to be responsible for the growth of the nanostructures at low temperatures. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of the seed crystallographic orientation on AlN bulk crystal growth by PVT method
Authors: Wang W. J. , Zuo S. B. , Bao H. Q. , Wang J. , Jiang L. B. , Chen X. L
Published: April 2011

The growth of AlN crystals by PVT method was investigated using TaC crucible in the temperature range of 2250‐2350 °C. AlN boules with 30 mm in diameter were successfully grown on the crucible lid by self‐seeded growth. The AlN boules consist of the spontaneously nucleated AlN single crystal grains with the {1010} natural crystalline face. The fast growth rate of more than 1 mm/h was achieved. AlN crystals grown on (11$ \bar 2 $0)‐, (10$ \bar 1 $0)‐, and (0001)‐face AlN seeds were investigated. Different experimental phenomena have been observed under particular condition. The crystal grown on (11$ \bar 2 $0)‐face seed has different natural crystalline face from the seed. For the crystal grown on (10$ \bar 1 $0) or (0001) seed, the crystal natural crystalline face is same as the crystallographic orientation of the seed. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Bioinspired synthesis of morphologically controlled SrCO3 superstructures by natural gum acacia
Authors: Sreedhar B. , Satyavani Ch. , Keerthi Devi D. , Rambabu C. , Basaveswara Rao M. V. , Saratchandra Babu M.
Published: April 2011

Crystallization of strontium carbonate is performed in aqueous solution using Gum Acacia (GA) as crystal growth modifier. A novel study of hierarchical assembly, specifically interacting inorganic and natural component without introduction of other additives was studied. SrCO3structures exhibiting the morphologies of well defined nanocrystallites in the form of clusters of hexagonal rods, flower shaped, cross like, doughnut shaped and rice grain shaped are identified by optimizing the conditions and concentration of GA. In continuation, morphology was also examined for mixed metal carbonates (Sr‐LaCO3, Sr‐TbCO3). The results indicate that –OH, –COOH and ‐NH2 functional group moieties of GA play a remarkable role in inhibiting growth morphology of metal carbonates and mixed metal carbonates. Structural characterization of the synthesized materials was investigated by Powder X‐ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive analysis (EDAX), Transmission electron microscopy (TEM), Thermogravimetric analysis (TGA) coupled Mass (MS) and Fourier transform infrared spectroscopy (FT‐IR). This synthesis method can be easily extended to a variety of inorganic nanoparticles, thereby enabling exact control over material properties. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Crystallography and cathodoluminescence of ultra‐long GaN nanowires
Authors: Liu B. Y. , Wu A. M. , Qin F. W.
Published: April 2011

Ultra‐long GaN nanowires have been synthesized via a simple thermal evaporation process by heating mixed GaN and Ga2O3 powders in a conventional resistance furnace under ammonia gas at 1150 °C. The average length of GaN nanowires is estimated to be more than 100 μm after 30‐min growth, corresponding to a fast growth rate of more than 200 μm/h. Scanning electron microscope (SEM) observation indicated that the diameter of GaN nanowires was rather uniform along the growth direction and in the range of 100–200 nm. X‐ray diffraction (XRD) and transmission electron microscope (TEM) measurements confirmed that the GaN nanowires are crystalline wurtzite‐type hexagonal structure. Room‐temperature cathodoluminescence (CL) measurement indicated that an obvious red‐shift of the near band‐edge emission peak centered at 414 nm of the ultra‐long GaN nanowires and a wide shoulder in the range of 600–700 nm were observed. Possible reasons responsible for the red‐shift of the near band‐edge emission of the ultra‐long GaN nanowires was discussed. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis of multi‐linked ZnO rods by microwave heating
Authors: Kathalingam A. , Chae Y. S. , Rhee J. K.
Published: April 2011

Synthesis of linked ZnO micro rods by microwave radiation and its characterization is presented in this report. In this simple microwave assisted solution phase route zinc nitrate and hexamethylenetetramine has been used as the starting materials for the synthesis of linked ZnO rods. Linked ZnO rods with various morphologies such as bipods, tripods, tetrapods and etc have been prepared. The influence of irradiation time of microwave on the formation of linked ZnO rods was investigated. X‐ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), and energy dispersive spectroscopy (EDS) were used for the characterization of the product. The FESEM images showed ZnO rods of diameter in the range of 100‐200 nm and length around 5000 nm. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fire reaction properties of concrete made with recycled rubber aggregate
Authors: Correia J. R. , Marques A. M. , Pereira C. M. C. , de Brito J.
Published: April 2011

This study investigates the fire reaction properties of concrete made with recycled rubber aggregate (CRRA). Four different concrete compositions were prepared: a reference concrete (RC) made with natural coarse aggregate and three concrete mixes with replacement rates of 5, 10 and 15% of natural fine and coarse aggregate by recycled rubber aggregate (RRA) obtained from used tyres. Specimens of CRRA were tested in a cone calorimeter according to the test standard ASTM E1354, submitted to heat fluxes of 25, 50 and 75kW/m2. These tests evaluated the effects of incorporating RRA in the fire reaction properties of concrete, namely in the heat release rate, the time to ignition (TTI), the remaining mass, the production of smoke, and the release of carbon dioxide and carbon monoxide. Owing to the organic nature of RRA, with the exception of the carbon monoxide yield, higher replacement rates of natural aggregates by RRA and increasing heat flux led to a worse fire reaction response, particularly in terms of TTI, heat release rate and smoke production. Results of these experiments were then used to estimate the European fire reaction classes of each concrete composition, using a flame spread model. All CRRA compositions tested were provisionally rated as class A2 or B and such ratings allowed defining the field of application of each solution under analysis, according to building code requirements. Copyright © 2011 John Wiley & Sons, Ltd.
Genetic ablation or chemical inhibition of phosphatidylcholine transfer protein attenuates diet-induced hepatic glucose production
Authors: Shishova Ekaterina Y. , Stoll Janis M. , Ersoy Baran A. , Shrestha Sudeep , Scapa Erez F. , Li Yingxia , Niepel Michele W. , Su Ya , Jelicks Linda A. , Stahl Gregory L. , Glicksman Marcie A. , Gutierrez-Juarez Roger , Cuny Gregory D. , Cohen David E.
Published: April 2011

Phosphatidylcholine transfer protein (PC-TP, synonym StARD2) is a highly specific intracellular lipid binding protein that is enriched in liver. Coding region polymorphisms in both humans and mice appear to confer protection against measures of insulin resistance. The current study was designed to test the hypotheses that

Pctp

−/− mice are protected against diet-induced increases in hepatic glucose production and that small molecule inhibition of PC-TP recapitulates this phenotype.

Pctp

−/− and wildtype mice were subjected to high-fat feeding and rates of hepatic glucose production and glucose clearance were quantified by hyperinsulinemic euglycemic clamp studies and pyruvate tolerance tests. These studies revealed that high-fat diet-induced increases in hepatic glucose production were markedly attenuated in

Pctp

−/− mice. Small molecule inhibitors of PC-TP were synthesized and their potencies, as well as mechanism of inhibition, were characterized

in vitro
. An optimized inhibitor was administered to high-fat-fed mice and used to explore effects on insulin signaling in cell culture systems. Small molecule inhibitors bound PC-TP, displaced phosphatidylcholines from the lipid binding site, and increased the thermal stability of the protein. Administration of the optimized inhibitor to wildtype mice attenuated hepatic glucose production associated with high-fat feeding, but had no activity in

Pctp

−/− mice. Indicative of a mechanism for reducing glucose intolerance that is distinct from commonly utilized insulin-sensitizing agents, the inhibitor promoted insulin-independent phosphorylation of key insulin signaling molecules.

Conclusion:

These findings suggest PC-TP inhibition as a novel therapeutic strategy in the management of hepatic insulin resistance. (Hepatology 2011;)
Activating transcription factor 6 plays protective and pathological roles in steatosis due to endoplasmic reticulum stress in zebrafish
Authors: Cinaroglu Ayca , Gao Chuan , Imrie Dru , Sadler Kirsten C.
Published: April 2011

Many etiologies of fatty liver disease (FLD) are associated with the hyperactivation of one of the three pathways composing the unfolded protein response (UPR), which is a harbinger of endoplasmic reticulum (ER) stress. The UPR is mediated by pathways initiated by PRKR-like endoplasmic reticulum kinase, inositol-requiring 1A/X box binding protein 1, and activating transcription factor 6 (ATF6), and each of these pathways has been implicated to have a protective or pathological role in FLD. We used zebrafish with FLD and hepatic ER stress to explore the relationship between Atf6 and steatosis. A mutation of the foie gras (

foigr

) gene caused FLD and hepatic ER stress. The prolonged treatment of wild-type larvae with tunicamycin (TN), which caused chronic ER stress, phenocopied

foigr
. In contrast, acute exposure to a high dose of TN robustly activated the UPR but was less effective at inducing steatosis. The sterol regulatory element binding protein transcription factors were not required for steatosis in any of these models. Instead, depleting larvae of active Atf6 either through a membrane-bound transcription factor peptidase site 1 mutation or an

atf6

morpholino injection protected them against steatosis caused by chronic ER stress, but exacerbated steatosis caused by acute TN treatment.

Conclusion

: ER stress causes FLD. A loss of Atf6 prevents steatosis caused by chronic ER stress but can also potentiate steatosis caused by acute ER stress. This demonstrates that Atf6 can play both protective and pathological roles in FLD. (Hepatology 2011;)
Horizontal hydraulic conductivity of shallow streambed sediments and comparison with the grain‐size analysis results
Authors: Lu Chengpeng , Chen Xunhong , Cheng Cheng , Ou Gengxin , Shu Longcang
Published: April 2011

Streambed horizontal hydraulic conductivity (Kh) has a substantial role in controlling exchanges between stream water and groundwater. We propose a new approach for determining Kh of the shallow streambed sediments. Undisturbed sediment samples were collected using tubes that were horizontally driven into streambeds. The sediment columns were analysed using a permeameter test (PT) on site. This new test approach minimizes uncertainties due to vertical flow in the vicinity of test tube and stream stage fluctuations in the computation of the Kh values. Ninety‐eight PTs using the new approach were conducted at eight sites in four tributaries of the Platte River, east‐central Nebraska, USA. The Kh values were compared with the nondirectional hydraulic conductivity values (Kg) determined from 12 empirical grain‐size analysis methods. The grain‐size analysis methods used the same sediment samples as Kh tests. Only two methods, the Terzaghi and Shepherd methods, yielded Kg values close to the Kh values. Although the Sauerbrei method produced a value relatively closer to Kh than other nine grain‐size analysis methods, the values from this method were not as reliable as the methods of Terzaghi and Shepherd due to the inconsistent fluctuation of the average estimates at each of the test sites. The Zunker, Zamarin, Hazen, Beyer, and Kozeny methods overestimated Kh, while the Slichter, US Bureau of Reclamation (USBR), Harleman, and Alyamani and Sen methods underestimated Kh. Any of these specific grain‐size methods might yield good estimates of streambed Kh at some sites, but give poor estimates at other sites, indicating that the relationship between Kg and Kh is significantly site dependent in our study. Copyright © 2011 John Wiley & Sons, Ltd.
Nitric oxide averts hypoxia‐induced damage during reoxygenation in rat heart
Authors: Rus Alma , Molina Francisco , Peinado M. Ángeles , Del Moral M. Luisa
Published: April 2011

Nitric oxide (NO), synthesized by the hemoproteins NO synthases (NOS), is known to play important roles in physiological and pathological conditions in the heart, including hypoxia/reoxygenation (H/R). This work investigates the role that endogenous NO plays in the cardiac H/R‐induced injury. A follow‐up study was conducted in Wistar rats subjected to 30 min of hypoxia, with or without prior treatment using the nonselective NOS inhibitor L‐NAME (1.5 mM). The rats were studied at 0 h, 12 h, and 5 days of reoxygenation, analysing parameters of cell, and tissue damage (lipid peroxidation, apoptosis, and protein nitration), as well as in situ NOS activity and NO production (NOx). The results showed that after L‐NAME administration, in situ NOS activity was almost completely eliminated in all the experimental groups, and consequently, NOx levels fell. Contrarily, the lipid peroxidation level and the percentage of apoptotic cells rose throughout the reoxygenation period. These results reveal that NOS inhibition exacerbates the peroxidative and apoptotic damage observed before the treatment with L‐NAME in the hypoxic heart, pointing to a cardioprotective role of NOS‐derived NO against H/R‐induced injury. These findings could open the possibility of future studies to design new therapies for H/R‐dysfunctions based on NO‐pharmacology. Microsc. Res. Tech., 2011. © 2011 Wiley‐pLiss, Inc.
Assembly modes of dragonfly wings
Authors: Zhao Hong‐Xiao , Yin Ya‐Jun , Zhong Zheng
Published: April 2011

The assembly modes of dragonfly wings are observed through FEG‐ESEM. Different from airplane wings, dragonfly wings are found to be assembled through smooth transition mode and global package mode. First, at the vein/membrane conjunctive site, the membrane is divided into upper and lower portions from the center layer and transited smoothly to the vein. Then the two portions pack the vein around and form the outer surface of the vein. Second, at the vein/spike conjunctive site, the vein and spike are connected smoothly into a triplet. Last, at the vein/membrane/spike conjunctive site, the membrane (i.e., the outer layer of the vein) transits smoothly to the spike, packs it around, and forms its outer layer. In short, the membrane looks like a closed coat packing the wing as a whole. The smooth transition mode and the global package mode are universal assembly modes in dragonfly wings. They provide us the references for better understanding of the functions of dragonfly wings and the bionic manufactures of the wings of flights with mini sizes. Microsc. Res. Tech., 2011. © 2011 Wiley Periodicals, Inc.
Termination Kinetics of 1‐Vinylpyrrolidin‐2‐one Radical Polymerization in Aqueous Solution
Authors: Schrooten Jens , Buback Michael , Hesse Pascal , Hutchinson Robin A. , Lacík Igor
Published: April 2011

Termination kinetics of 1‐vinylpyrrolidin‐2‐one radical polymerization in aqueous solution has been studied at 40 °C between 20 and 100 wt.‐% VP. The /kpvalues from laser single‐pulse experiments with microsecond time‐resolved NIR detection of monomer conversion, in conjunction withkpfrom literature, yield chain‐length‐averaged termination rate coefficients, . Because of better signal‐to‐noise quality, experiments were carried out at 2 000 bar, but also at 1 500, 1 000, and 500 bar, thus allowing for estimates of  at ambient pressure. The dependence of  on monomer conversion indicates initial control by segmental diffusion followed by translational diffusion and finally reaction diffusion control. To assist the kinetic studies, viscosities of VP–water mixtures at ambient pressure have been determined.

magnified image
The economic impact of cognitive impairment in Parkinson's disease
Authors: Vossius Corinna , Larsen Jan P. , Janvin Carmen , Aarsland Dag
Published: April 2011

Background:

We investigated to what extent cognitive impairment and dementia were related to the direct medical and nonmedical costs in Parkinson's disease.

Methods:

Sixty‐one patients with Parkinson's disease from a population‐based cohort were assessed for motor and cognitive symptoms in 1993, 1997, and 2001. Data on use of health care and social services were collected.

Results:

The costs of patients with dementia were 3.3 times higher (€34,980) than those of nondemented patients (€10,626) per year of survival. Institutional care was the largest cost factor, representing 67% of the costs. Cognitive functioning predicted direct costs by 29.4%. Cognitive decline was associated with increased costs, even in nondemented subjects.

Conclusions:

Our findings suggest that dementia has a substantial impact on direct costs in Parkinson's disease, mainly due to high costs for institutional care. In addition, there were indications that even patients with mild cognitive impairment have higher nonmedical costs. © 2011 Movement Disorder Society
Cardiac autonomic denervation in Parkinson's disease is linked to REM sleep behavior disorder
Authors: Postuma Ronald B. , Montplaisir Jacques , Lanfranchi Paola , Blais Hélène , Rompré Sylvie , Colombo Roberto , Gagnon Jean‐François
Published: April 2011

Background:

Recent studies have suggested a close connection between autonomic dysfunction and rapid eye movement sleep behavior disorder, which differs in nature from other early‐stage markers of Parkinson's disease. In this study we examined the relationship between rapid eye movement sleep behavior disorder and autonomic dysfunction in Parkinson's disease as measured by cardiac beat‐to‐beat variability.

Methods:

In 53 patients with Parkinson's disease and 36 controls, electrocardiographic trace from a polysomnogram was assessed for measures of beat‐to‐beat RR variability including RR‐standard deviation and frequency domains (low‐ and high‐frequency components). Results were compared between patients with Parkinson's disease and controls, and between patients with Parkinson's disease with and without rapid eye movement sleep behavior disorder.

Results:

On numerous cardiac autonomic measures, patients with Parkinson's disease showed clear abnormalities compared with controls. However, these abnormalities were confined only to those patients with associated rapid eye movement sleep behavior; those without were not different than controls.

Conclusions:

As with other clinical autonomic variables, cardiac autonomic denervation is predominantly associated not with Parkinson's disease itself, but with the presence of rapid eye movement sleep behavior disorder. © 2011 Movement Disorder Society
Reward processing abnormalities in Parkinson's disease
Authors: Kapogiannis Dimitrios , Mooshagian Eric , Campion Paul , Grafman Jordan , Zimmermann Trelawny J. , Ladt Kelsey C. , Wassermann Eric M.
Published: April 2011

The primary motor cortex is important for motor learning and response selection, functions that require information on the expected and actual outcomes of behavior. Therefore, it should receive signals related to reward. Pathways from reward centers to motor cortex exist in primates. Previously, we showed that gamma aminobutyric acid–A–mediated inhibition in the motor cortex, measured by paired transcranial magnetic stimulation, changes with expectation and uncertainty of money rewards generated by a slot machine simulation. We examined the role of dopamine in this phenomenon by testing 13 mildly affected patients with Parkinson's disease, off and on dopaminergic medications, and 13 healthy, age‐matched controls. Consistent with a dopaminergic mechanism, reward expectation or predictability modulated the response to paired transcranial magnetic stimulation in controls, but not in unmedicated patients. A single dose of pramipexole restored this effect of reward, mainly by increasing the paired transcranial magnetic stimulation response amplitude during low expectation. Levodopa produced no such effect. Both pramipexole and levodopa increased risk‐taking behavior on the Iowa Gambling Task. However, pramipexole increased risk‐taking behavior more in patients showing lower paired transcranial magnetic stimulation response amplitude during low expectation. These results provide evidence that modulation of motor cortex inhibition by reward is mediated by dopamine signaling and that the physiological state of the motor cortex changes with risk‐taking tendency in patients on pramipexole. The cortical response to reward expectation may represent an endophenotype for risk‐taking behavior in patients on agonist treatment. © 2011 Movement Disorder Society
Adverse effects of concentrated green tea extracts
Authors: Schönthal Axel H.
Published: April 2011

A myriad of health claims are being made in favor of the consumption of green tea. However, mostly due to the easy availability and greater than ever popularity of highly concentrated green tea extracts, sometimes combined with an attitude of more‐is‐better, certain health risks of green tea consumption have begun to emerge. Among such risks are the possibility of liver damage, the potential to interact with prescription drugs to alter their therapeutic efficacy, and the chance to cause harm when combined with other highly popular herbal remedies. This review will summarize documented examples of adverse effects of green tea in humans, and will discuss risks of copious consumption of highly concentrated green tea extracts as indicated by studies in animals. While there is no intention to minimize any of the scientifically established benefits of the use of green tea, the purpose of this review is to focus primarily on the potential for adverse effects and raise awareness of the rare, yet underappreciated risks.
Interaction of hydroxycinnamic acids and their conjugates with organic anion transporters and ATP‐binding cassette transporters
Authors: Wong Chi C. , Barron Denis , Orfila Caroline , Dionisi Fabiola , Krajcsi Peter , Williamson Gary
Published: April 2011

Scope: Hydroxycinnamic acids are abundant antioxidants in our diet. In humans, hydroxycinnamic acids are metabolized to form sulfates and glucuronides, with the majority recovered in urine.

Methods and results: We assessed the potential roles of organic anion transporters (OATs) and ATP‐binding cassette (ABC) transporters in the renal uptake and efflux of hydroxycinnamic acid conjugates. Uptake studies using OAT1 (SLC22A6)‐, OAT2 (SLC22A7)‐, and OAT3 (SLC22A8)‐expressing 293H embryonic kidney cells showed that OAT1 and OAT3, but not OAT2, accepted hydroxycinnamic acid conjugates as substrates. OAT1 and OAT3 mediated the basolateral uptake of hydroxycinnamic acid sulfates and glucuronide conjugates, respectively. Hydroxycinnamic acid sulfates are substrates of OAT4 and were capable of trans‐stimulating 5‐carboxyfluorescein uptake mediated by OAT4. On the other hand, hydroxycinnamic acid conjugates are not substrates for the ABC transporters, multidrug resistance protein 2 (MRP2/ABCC2) or breast cancer resistance protein (BCRP/ABCG2), demonstrated by the inability to alter ATPase activity. Cis‐inhibition studies with OATs and MRPs revealed that hydroxycinnamic acid conjugates have limited impact on the transport of model substrates significantly at physiological concentrations.

Conclusion: Concerted action of OAT1, OAT3, and OAT4 is involved in the elimination of hydroxycinnamic acid conjugates into urine, whereas MRP2 and breast cancer resistance protein are not involved in the disposition of these conjugates.
Green tea and breast cancer
Authors: Wu Anna H. , Butler Lesley M.
Published: April 2011

The identification of modifiable lifestyle factors that could reduce the risk of breast cancer is a research priority. Despite the enormous chemopreventive potential of green tea and compelling evidence from animal studies, its role in breast cancer development in humans is still unclear. Part of the uncertainty is related to the relatively small number of epidemiological studies on green tea and breast cancer and that the overall results from case‐control studies and prospective cohort studies are discordant. In addition, the mechanisms by which green tea intake may influence risk of breast cancer in humans remain not well studied. We review the human studies that have evaluated the relationship between green tea intake and four biomarkers (sex steroid hormones, mammographic density, insulin‐like growth factor, adiponectin) that are believed to be important in breast cancer development. Results from these biomarker studies are also inconclusive. Limitations of observational studies and areas of further investigations are discussed.
Exercise training improves autonomic profiles in patients with Charcot–Marie–Tooth disease
Authors: El Mhandi Lhassan , Pichot Vincent , Calmels Paul , Gautheron Vincent , Roche Frédéric , Féasson Léonard
Published: April 2011

Introduction:

The effect of an interval exercise training (ITE) program on heart rate variability (HRV) was studied in 8 patients with Charcot–Marie–Tooth (CMT) disease and 8 healthy controls.

Methods:

At baseline, all subjects underwent ambulatory 24‐hour Holter electrocardiographic (ECG) monitoring to evaluate HRV. HRV analysis was repeated on CMT patients after they completed a 24‐week ITE program on a cycle ergometer.

Results:

Before exercise, all HRV indices were lower in patients compared with controls, and the difference reached statistical significance for pNN50 (percent of differences between adjacent R–R intervals exceeding 50 ms). After ITE, time‐ and frequency‐domain indices were significantly improved, particularly at night (+8% mean R–R interval, +95% pNN50, 52% reduction in low/high‐frequency ratio). We observed significant increases in some of the time and frequency parameters, and values sometimes exceeded those of controls at baseline.

Conclusions:

Our results suggest that ITE improves HRV modulation in CMT patients by enhancing parasympathetic activity. Muscle Nerve, 2011
Coupled modelling of hydro‐mechanical behaviour of unsaturated compacted expansive soils
Authors: Sun Wenjing , Sun De'an
Published: April 2011

The Barcelona basic model cannot predict the mechanical behaviour of unsaturated expansive soils, whereas the Barcelona expansive model (BExM) can only predict the stress–strain behaviour of unsaturated expansive soils without the water‐retention behaviour being incorporated. Moreover, the micro‐parameters and the coupling function between micro‐structural and macro‐structural strains in the BExM are difficult to determine. Experimental data show that the compression curves for non‐expansive soils under constant suctions are shifted towards higher void ratios with increasing suction, whereas the opposite is true for expansive soils. According to the observed water‐retention behaviour of unsaturated expansive soils, the air‐entry value increases with density, and the relationship between the degree of saturation and void ratio is linear at constant suction.

According to the above observation, an elastoplastic constitutive model is developed for predicting the hydraulic and mechanical behaviour of unsaturated expansive soils, based on the existing hydro‐mechanical model for non‐expansive unsaturated soil. The model takes into consideration the effect of degree of saturation on the mechanical behaviour and that of void ratio on the water‐retention behaviour. The concept of equivalent void ratio curve is introduced to distinguish the plastic potential curve from the yield curve. The model predictions are compared with the test results of an unsaturated expansive soil, including swelling tests under constant net stress, isotropic compression tests and triaxial shear tests under constant suction. The comparison indicates that the model offers great potential for quantitatively predicting the hydraulic and mechanical behaviour of unsaturated expansive soils. Copyright © 2011 John Wiley & Sons, Ltd.
Efficient modeling of localized material failure by means of a variationally consistent embedded strong discontinuity approach
Authors: Mosler J. , Stanković L. , Radulović R.
Published: April 2011

This paper is concerned with a novel embedded strong discontinuity approach suitable for the analysis of material failure at finite strains. Focus is on localized plastic deformation particularly relevant for slip bands. In contrast to already existing models, the proposed implementation allows to consider several interacting discontinuities in each finite element. Based on a proper re‐formulation of the kinematics, an efficient parameterization of the deformation gradient is derived. It permits to compute the strains explicitly that improves the performance significantly. However, the most important novel contribution of the present paper is the advocated variational constitutive update. Within this framework, every aspect is naturally driven by energy minimization, i.e. all unknown variables are jointly computed by minimizing the stress power. The proposed update relies strongly on an extended principle of maximum dissipation. This framework provides enough flexibility for different failure types and for a broad class of non‐associative evolution equations. By discretizing the aforementioned continuous variational principle, an efficient numerical implementation is obtained. It shows, in addition to its physical and mathematical elegance, several practical advantages. For instance, the physical minimization principle itself specifies automatically and naturally the set of active strong discontinuities. Copyright © 2011 John Wiley & Sons, Ltd.