bluuebunny/crossref_metadata_2025 huggingface dataset:
Evidence of Scrambling over Ruthenium‐based Catalysts in Supercritical‐water Gasification
Authors: Peterson Andrew A. , Dreher Marian , Wambach Jörg , Nachtegaal Maarten , Dahl Søren , Nørskov Jens K. , Vogel Frédéric
Published: June 2012

Catalytic processes that employ Ru catalysts in supercritical water have been shown to be capable of converting organics, such as wood waste, into synthetic natural gas (CH4) with high efficiencies at relatively moderate temperatures of around 400 °C. However, the exact roles of the catalyst and the descriptors that would enable the search for other catalysts with high conversions have not been determined. In the current work, we use electronic structure calculations coupled with batch experiments to understand the interaction of methane (CH4) and water (H2O) with a common catalyst material, ruthenium, to understand the final steps of the methanation reaction. The calculations predict that when CH4 and H2O react with the Ru surface, the species will undergo rapid scrambling; interchanging most of the hydrogens with the surface before escaping as CH4 and H2O once again. We conducted experiments using CH4 as a feedstock in supercritical D2O (deuterated water) in the presence of a commercially available carbon‐supported Ru catalyst, and found this mechanism to be confirmed: nearly all reacted CH4 was converted to the fully substituted CD4 or the 3/4‐substituted CHD3 isotopomers, with less significant production of the 1/4‐ or 1/2‐substituted species CH3D and CH2D2. The experiment was repeated with an in‐house impregnated RuO2‐on‐carbon catalyst, with similar results. Although other criteria such as the ability to cleave CC and CO bonds and resistance to poisoning will also prove important, this study suggests that a characteristic of an effective catalyst for supercritical water gasification to methane is its ability to promote rapid equilibria through scrambling mechanisms.
Phase‐switching Homogeneous Catalysis for Clean Production of Biodiesel and Glycerol from Soybean and Microbial Lipids
Authors: Cao Xuefeng , Xie Haibo , Wu Zhilian , Shen Hongwei , Jing Bo
Published: June 2012

With the increasing concerns into the utilization of lipids as renewable resources for production of biofuels, chemicals, and materials, the efficient extraction and conversion of lipid is one of most important issues for the foundation of cost competitive lipid‐economy. In this study, we found that by using a range of “switchable solvents” from 1,8‐diazabicyclo[5.4.0]undec‐7‐ene to methanol, CO2, a recognized greenhouse gas, can be used as a trigger to catalyze the methanolysis of soybean and microbial lipids, and facilitate the separation of fatty acid methyl esters (FAMEs) and glycerol. It was found that the FAMEs can be decanted from the system in a 95.2 % conversion efficiency. The produced glycerol can be extracted from the FAMEs completely by the “switchable solvents”, and can be separated with high purity after recycling the DBU by an easy extraction process. Our primary investigation of the in situ extraction and conversion of microbial lipids from oleaginous yeast (Rhodosporidium toruloides Y4) shows that, although a 95.4 % extraction yield was achieved, the methanolysis efficiency was only 21.9 %. Our study presents an efficient and facile process for the integrated clean production of biodiesel and glycerol from soybean and microbial lipids, and the catalyst DBU can be recycled by an easy extraction process.
A restricted b‐spline basis for S‐shaped calibration curves
Authors: Jones Geoff , Kawabata Emily
Published: June 2012

S‐shaped curves arise in many calibration assays. They are typically modeled using an empirically chosen nonlinear function. Nonparametric alternatives usually perform poorly because there are often insufficient data points and there are difficulties in enforcing the required asymptotic behavior. We propose an alternative approach using a b‐spline basis adapted to produce lower and upper asymptotes in the fitted curves. Its main advantage is that, with pre‐determined knot positions, the model is linear in the parameters and so is more numerically stable than a nonlinear model; this has advantages in, for example, fitting a mixed model to multiple curves. We explore the performance of this approach using data from a single radioimmunoassay for cortisol and from a set of 96 ELISA assays for the herbicide atrazine. Copyright © 2012 John Wiley & Sons, Ltd.
Unidirectional growth of α‐NiSO4·6H2O crystal by Sankaranarayanan–Ramasamy (SR) method
Authors: Hemmati M. , Rezagholipour Dizaji H.
Published: June 2012

Large cylindrical [001] direction α‐nickel sulphate hexahydrate crystal with 20 mm diameter and 140 mm length was grown from an aqueous solution by uniaxially solution‐crystallization method of Sankaranarayanan–Ramasamy (SR). The grown crystal was examined by X‐ray diffraction, UV‐Vis‐NIR spectroscopy and TGA/DTA analysis methods.
Structure and magnetism of ZnO/Co multilayers prepared by pulsed laser deposition
Authors: Wang Zhanyong , Zhao Hongyang , Yao Qiwen , Xu Jiayue , Kimura Hideo
Published: June 2012

ZnO/Co multilayers were fabricated on silicate (100) substrate by a pulsed laser deposition method at room temperature. The x‐ray diffraction (XRD) results reveal that the as‐deposited multilayer film is composed of amorphous phase, which leads to high saturation magnetization and low coercivity. Higher coercivity is observed in the ZnO/Co films annealed at 390 °C due to the formation of crystalline metallic Co and semiconducting ZnO. But much higher annealing temperature leads to the oxidation of metallic Co and the reaction between Co and ZnO, which decreases the saturation magnetization and coercivity obviously.
Controllable thermal expansion properties of In2 − xCrxMo3O12
Authors: Wu M. M. , Zu Y. , Peng J. , Liu R. D. , Hu Z. B. , Liu Y. T. , Chen D. F.
Published: June 2012

Solid solutions In2 − xCrxMo3O12 have been prepared via the solid state reaction method. The structural and thermal expansion properties have been characterized using X‐ray diffraction. All compounds exhibit monoclinic structure with space group P21/a at room temperature, and transform to orthorhombic structure at higher temperature. Compounds In2 − xCrxMo3O12 (x = 0.7, 1.0 and 1.3) possess strong positive thermal expansion in the monoclinic structure, while their thermal expansion coefficients of orthorhombic structure vary from negative to positive with increasing Cr content. It is worthwhile to note that In1.3Cr0.7Mo3O12 and InCrMo3O12 have near zero thermal expansion properties.
Physical properties of Zn‐ 22 wt.% Al‐ x wt.% Ce melt spun eutectoid alloy
Authors: Ahmed E. M.
Published: June 2012

Zn‐ 22 wt.% Al (Zn ‐ 40 Al in atomic%) eutectoid alloys with different Cerium (Ce) contents of 0, 1, 2, and 6 (in wt.%), 0.35, 0.70 and 2.1 (in atomic%) were rapidly solidified by melt spun technique. The effects of high cooling rate and alloying element (Ce) on microstructure of the studied alloys were analyzed by X‐ray diffractometry (XRD), scanning electron microscopy (SEM) and electrical resistance measurements. The results showed that the dendrites as well as grains size were refined by the additions of Ce. The main phases in melt spun alloys were α‐Al and η‐Zn, in addition to intermetallic CeZn5 and Al4Ce. Additional metastable intermetallic Al0.71Zn0.29 phase has been observed only for melt spun alloy of 6 wt.% Ce content. XRD peaks of melt spun alloys demonstrated a considerable broadening with percentage of Ce due to the grain refinement and lattice distortion. Moreover, increase of Ce content results in a decrease of Al lattice constant which could be related to formation of supersaturated solid solution of Zn and/or Ce in α‐Al. Crystallite size of all phases were in the range of nanometer scale which reflects the role of the high cooling rate and the existence of Ce as alloying element for producing nanocrystalline structure. Resistance measurements of melt spun alloys show that the relative resistance rate for the alloys of higher Ce content relaxed faster to lower value than that of lower Ce content. Electrical resistance and microstructure exhibit strongly Ce content dependence.
Inhibiting Wipf2 downregulation by transgenic expression of its 3′ mRNA‐untranslated region improves cytotoxicity and vaccination response
Authors: Pankewycz Oleh , Ambrus Julian , Shen Long , Xuan Jingxiu , Li Hong , Wu Jing , Guo Li‐Wu , Feng Lin , Laftavi Mark R.
Published: June 2012

Lymphocyte activation results in profound changes in the abundance of mRNA transcripts many of which are downregulated. The Wiskott–Aldrich syndrome (WAS) protein (WASP) family is critical for productive T‐cell receptor signaling and actin reorganization. The WASP signal pathway includes the WAS/WAS‐like (WASL) interacting protein family 2 (WIPF2) gene also known as WIRE/WICH. We show that both human WIPF2 and mouse Wipf2 are mice, alternatively spliced within the 3′ untranslated region (3′UTR) resulting in two major transcripts of approximately 4.5 and 6 kb in size. Following T‐cell activation, the level of human WIPF2 and mouse Wipf2 mRNA rapidly declines. In mice, this decline is accompanied by a marked reduction in WIPF2 protein levels. Transgenic expression of a 240‐bp fragment derived from a highly conserved terminal 3′UTR found within the 6‐kb transcript blocks Wipf2 downregulation. These effects may be mediated by competitive inhibition of microinhibitory RNA (miRNA) regulation since the 6‐kb‐derived transgene and the 4.5‐kb transcript share functional binding sites for miRNA146a. Blocking Wipf2 gene and protein repression resulted in improved T‐cell responses to antigen immunization in vivo as well as in vitro cytotoxic T‐cell killing. Collectively, these data suggest that early downregulation of this immunologically relevant gene controls the intensity of selective lymphocyte functions.
The development of IL‐17/IFN‐γ‐double producing CTLs from Tc17 cells is driven by epigenetic suppression of Socs3 gene promoter
Authors: Satoh Takayuki , Tajima Masaki , Wakita Daiko , Kitamura Hidemitsu , Nishimura Takashi
Published: June 2012

The plasticity of T lymphocytes induced by epigenetic modifications of gene promoters may play a pivotal role in controlling their effector functions, which are sometimes causally associated with immune disorders. IL ‐17‐producing T cells, which induce type 17 immune responses, are newly identified pathogenic effector cells. The type 1 signature cytokine IFN‐γ strongly inhibits their differentiation, indicating a mutually exclusive relationship between type 17‐ and type 1‐immune responses. However, many reports indicate the presence of a unique IL‐17/IFN‐γ‐double producing T‐cell subset in various inflammatory settings, although the mechanisms responsible for their development and their precise functions remain unclear. Here, we demonstrate that IL‐12 permits the conversion of mouse IL‐17‐producing CD8+ T (Tc17) cells to IL‐17/IFN‐γ‐double producing CD8+ T (Tc17/IFN‐γ) cells, and that this conversion is due to repressive epigenetic modifications of Socs3 gene promoters. Moreover, we show that SOCS3 strongly regulates the capability of Tc17 cells to produce IL‐17, in addition to regulating the expression of the type 17‐master regulator RORγt. These findings elucidate the mechanisms underlying the conversion of Tc17 cells into Tc17/IFN‐γ cells. As these cells are known to have potent antitumor activities, manipulation of these conversion mechanisms for therapeutic tumor immunity may be possible.
Fatty acids, 4‐desmethylsterols, and triterpene alcohols from Tunisian lentisc (Pistacia lentiscus) fruits
Authors: Trabelsi Hajer , Sakouhi Faouzi , Renaud Justin , Villeneuve Pierre , Khouja Mohamed L. , Mayer Paul , Boukhchina Sadok
Published: June 2012

A comparative study was performed to determine the fatty acid, 4‐desmethylsterol and triterpenic alcohols compositions of three different Tunisian populations of Pistacia lentiscus fruit Rimel (RM), Korbous (KO), and Tebaba (TB). Fruits are rich in lipids, which varied from 39.37% (KO) to 42.48% (TB) on a dry weight basis. Qualitatively, fatty acid, sterol, mono‐ and dimethylsterol composition is identical for all populations. Oleic acid was the major fatty acid for all samples, accounting from 40.49% in TB population to 50.72% in RM population followed by the palmitic and linoleic acids. Other fatty acids are present at lower levels. Total sterol amount varied from 109.72 mg/100 g of oil (KO) to 434.26 mg/100 g of oil (RM) with an average of 248.74 mg/100 g of oil. The major 4‐desmethylsterol component in all studied Tunisian populations of P. lentiscus oil was ß‐sitosterol followed by campesterol in TB and KO, and by stigmasterol in RM. The amount of total triterpenic alcohols varied from 42.39 mg/100 g of oil in RM population to 70.41 mg/100 g oil in TB population. The quantitative difference in the fatty acids and 4‐desmethylsterols of the different populations studied could be due to the effect of geographic region and soil type.
Formulation, preparation, and stability of intravenous bufadienolides‐loaded lipid microspheres
Authors: Weng Yan , Pan Cheng , Meng Jia , Tian Bin , Xi Miaomiao , Yang Zhifu , Li Yuwen , Guan Yue , Tang Xing , Wen Aidong
Published: June 2012

The purpose of this study was to develop a new formulation of intravenous lipid microspheres for bufadienolides (bufadienolides‐loaded lipid microspheres, BU‐LM) and investigate the stability of BU‐LM after dilution and long‐term storage. Photon correlation spectroscopy, electrophoretic light scattering, and light microscopy were used to evaluate the physical characteristics of BU‐LM. The chemical properties of bufadienolides were measured by high‐performance liquid chromatography. The optimum BU‐LM, consisting of 10% MCT, 3.0% Lipoid S75, 0.4% F68, 0.05% sodium oleate and 2.5% glycerol, was prepared by emulsification with a high‐speed shear mixing at 10 000 rpm for 12 min and a high‐pressure homogenization at 800 bar for 8 cycles at 30°C. The BU‐LM at pH 6.48, with the particle size distribution of 175.2 ± 57.3 nm, ζ‐potential of −32.10 mV, entrapment efficiency of 86.9%, 91.7%, 92.9%, and contents of 20.8%, 31.3%, 50.4% for B, C, R, respectively, was stable after sterilization in a 121°C rotating autoclave water steam bath for 10 min. Moreover, BU‐LM had sufficient physicochemical stability after dilution with 5% glucose injection and long‐term storage at 4 ± 2°C for 18 months. BU‐LM has a great potential for clinical applications as a new drug delivery system for bufadienolides.

Practical applications: Bufadienolides, mainly composed of bufalin (B), cinobufagin (C), and resibufogenin (R) have poor aqueous solubility and are chemically unstable. Currently the main marketable products of bufadienolides are solution injections, which cause serious venous irritation and in this formulation, the drug is not protected from degradation. Lipid microspheres, with the unique properties of a low cost, low toxicity, good storage stability, easy to scale up production, sustained release and targeting effect, incorporate the drugs into the interior oil phase and the oil‐water interfacial film; thus a direct contact of the drug with body fluids and tissues is prevented, which increases the stability of the drugs and minimizes the possible side effects.
Removal of copper from wastewater by using the synthetic nesquehonite
Authors: Shan Qiyan , Zhang Yue , Xue Xiangxin
Published: June 2012

The preparation of nesquehonite and calcium carbonate using low‐grade magnesite as a starting material, as well as the chemical treatment of copper‐bearing heavy metal wastewater by using nesquehonite as a novel precipitating agent was investigated for the first time. The precipitation of copper with nesquehonite was shown to be successful in reducing the level of soluble copper in solution. The precipitation completion being reached within 30 min. The removal efficiency of copper was not affected by the addition of nesquehonite and a removal efficiency up to 99.97% was achieved as excess coefficient of nesquehonite was 0%. At this time, the precipitated amount of copper by nesquehonite was 459 mg/g. The residual copper concentration was 0.1 mg/L, and final pH value was 6.8, which met the Chinese discharge limit (0.5–2.0 mg/L, GB8978‐1996) and the USEPA enforceable limit of 0.25 mg/L. The precipitate produced was very rich in copper, which occurred in the form of Cu(OH)2, CuCO3, Cu2(OH)2CO3, Cu3(OH)2(CO3)2, and Cu4(OH)6SO4·H2O. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 543–546, 2013
Absorption of NO by using aqueous KMnO4/(NH4)2CO3 solutions
Authors: Pan Wei‐guo , Guo Rui‐tang , Zhang Xiao‐bo , Ren Jian‐xing , Jin Qiang , Xu Hong‐jian
Published: June 2012

The absorption process of NO into KMnO4/(NH4)2CO3 solutions was studied in a stirred tank reactor. The experimental results showed that the reaction process was a fast pseudo‐m reaction. The reaction between NO and aqueous solutions of KMnO4/(NH4)2CO3 was found to be first‐order with respect to NO and with respect to KMnO4. The frequency factor and the average activation energy of this reaction were 2.3 × 109 m3/(mol s) and 36.77 kJ/mol, respectively. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 564–568, 2013
Genetic characterization of mesenchymal, clear cell, and dedifferentiated chondrosarcoma
Authors: Meijer Danielle , de Jong Danielle , Pansuriya Twinkal C. , van den Akker Brendy E. , Picci Piero , Szuhai Karoly , Bovée Judith V.G.M.
Published: June 2012

Clear cell, mesenchymal, and dedifferentiated chondrosarcoma are rare, cartilaginous tumors with limited treatment options other than surgery. Conventional chondrosarcomas have been extensively studied at the genetic level, but for rare chondrosarcoma subtypes, this is merely restricted to case reports. Information on the genetics of rare chondrosarcomas may provide insight into the etiology of these specific disease subtypes and possible alternative treatment strategies. Therefore, the aim of this study was to genetically characterize this subset of rare tumors. Using array CGH, we gathered genomic information of 30 rare cartilaginous tumors. In addition, we constructed tissue microarrays with 2 mm cores of 23 clear cell, 23 mesenchymal, and 45 dedifferentiated chondrosarcomas, in triplicate. Using immunohistochemistry, we investigated expression of R132H IDH1, and p53 and retinoblastoma pathways. Results were verified and further investigated with a methylation assay and MLPA for CDKN2A/p16, and IDH1/2, and TP53 mutation analysis. Array‐CGH showed numerous genomic alterations in all subtypes. However, only a limited number of recurrent alterations were detected, none of which seemed to be associated with the subtypes. The IDH1/2, p53, and retinoblastoma pathways were affected in 0, 9, and 95% of clear cell chondrosarcomas, in 0, 39, and 70% in mesenchymal chondrosarcomas, and in 50, 59, and 85% of dedifferentiated chondrosarcomas, respectively. Our results suggest an important role for the retinoblastoma pathway in all three rare chondrosarcoma subtypes investigated. © 2012 Wiley Periodicals, Inc.
Diversity of the juxtamembrane and TKD1 mutations (Exons 13–15) in the FLT3 gene with regards to mutant load, sequence, length, localization, and correlation with biological data
Authors: Schnittger Susanne , Bacher Ulrike , Haferlach Claudia , Alpermann Tamara , Kern Wolfgang , Haferlach Torsten
Published: June 2012

In acute myeloid leukemia (AML) mutations in the juxtamembrane and tyrosine kinase 1 domain (exons 13–15) of the FLT3 gene (FLT3‐ITD/LM) are heterogeneous with respect to mutation load, size, and localization. We characterized length and structure of these mutations by fragment analysis and sequencing in 689 AML which were identified among 3,365 (20.5%) newly diagnosed AML (1,803 males, 1,562 females; 15.8–91.8 years). Mutations were heterogeneous in length (median: 63, range: 3–1,236 nucleotides; nt). Most frequent were sizes of 21 (8.4%) or 24 nt (6.0%). Ninety‐one different insertion sites were observed (between nt 1,788 and 1,934, according to accession “FLT3 [Ensembl/Havana merge: ENSG00000122025]” with nt 1,856 (n = 41) and 1,863 (n = 35) being most frequent. In addition, 89 different insertion end points were observed between nt 1,790 and 1,994. FLT3‐mutation/wild‐type ratio was available in 615 patients (median, 0.80; range 0.03–181.73). 128 Patients (20.8%) had ratios <0.3, 334 (54.3%) had ratio ≥0.3 <1, 118 (19.2%) ≥1, and 35 (5.7%) showed complete loss of the FLT3‐wild‐type allele. Overall (OS) and event‐free (EFS) survival were better for FLT3‐negative than FLT3mut normal karyotype patients (P = 0.078 and P = 0.004, respectively) and patients with low level FLT3‐mutations had significantly longer OS and EFS compared with high level mutations (FLT3‐mutation/wild‐type ratio ≥1) (P < 0.001 and P = 0.002, respectively). The length of the mutation had no prognostic impact. Mutations localized more 5′ were associated with better outcome than more 3′mutations, but no strict association to certain functional domains was detected. In conclusion, FLT3‐mutations are extremely heterogenous with mutation load being the most relevant parameter. © 2012 Wiley Periodicals, Inc.
The development of effective biomarkers for Alzheimer's disease: a review
Authors: Henry Mark S. , Passmore Anthony P. , Todd Stephen , McGuinness Bernadette , Craig David , Johnston Janet A.
Published: June 2012

Objective

There is a widely recognised need to develop effective Alzheimer's disease (AD) biomarkers to aid the development of disease‐modifying treatments, to facilitate early diagnosis and to improve clinical care. This overview aims to summarise the utility of key neuroimaging and cerebrospinal fluid (CSF) biomarkers for AD, before focusing on the latest efforts to identify informative blood biomarkers.

Design

A literature search was performed using PubMed up to September 2011 for reviews and primary research studies of neuroimaging (magnetic resonance imaging, magnetic resonance spectroscopy, positron emission tomography and amyloid imaging), CSF and blood‐based (plasma, serum and platelet) biomarkers in AD and mild cognitive impairment. Citations within individual articles were examined to identify additional studies relevant to this review.

Results

Evidence of AD biomarker potential was available for imaging techniques reflecting amyloid burden and neurodegeneration. Several CSF measures are promising, including 42 amino acid β‐amyloid peptide (Aβ42); total tau (T‐tau) protein, reflecting axonal damage; and phosphorylated tau (P‐tau), reflecting neurofibrillary tangle pathology. Studies of plasma Aβ have produced inferior diagnostic discrimination. Alternative plasma and platelet measures are described, which represent potential avenues for future research.

Conclusions

Several imaging and CSF markers demonstrate utility in predicting AD progression and determining aetiology. These require standardisation before forming core elements of diagnostic criteria. The enormous potential available for identifying a minimally‐invasive, easily‐accessible blood measure as an effective AD biomarker currently remains unfulfilled. Copyright © 2012 John Wiley & Sons, Ltd.
Chronic renal failure in lithium‐using geriatric patients: effects of lithium continuation versus discontinuation—a 60‐month retrospective study
Authors: Rej Soham , Abitbol Roza , Looper Karl , Segal Marilyn
Published: June 2012

Objective

Lithium remains an important treatment in bipolar disorder. Although lithium is often discontinued because of signs of renal failure, it is unclear if this alters the course of renal function in the majority of patients. We hypothesize that in geriatric patients with chronic renal failure (CRF), who have a high burden of medical illness, lithium continuation does not significantly impact renal function (glomerular filtration rate (eGFR)).

Methods

We conducted a retrospective study of tertiary‐care geriatric psychiatry outpatients with a history of lithium use and evidence of CRF (eGFR ≤ 60 ml/min/1.73 m2 on ≥ 2 occasions in ≥ 3 months). The 27 patients who met these criteria were divided into lithium ‘continuers’ (continued use ≥ 2 years following CRF) and ‘discontinuers’. Mean eGFR and creatinine were followed at 21 and 60 months after developing CRF.

Results

Mean serum eGFR and creatinine were not significantly different between groups at any time during follow‐up. When comparing renal function at 60 months to baseline, a trend towards increased creatinine was seen in continuers (p = 0.06) but not in discontinuers. Changes in eGFR in continuers and discontinuers after 60 months did not achieve statistical significance (p = 0.35 and 0.98). However, clinically important decreases in eGFR occurred in the majority of continuers but in none of the discontinuers.

Conclusions

There was a trend towards declining renal function in lithium continuers at 60‐month follow‐up. Future prospective longitudinal studies will be needed to confirm our findings. We suggest vigilance and close monitoring of renal function when continuing CRF patients on lithium for extended periods. Copyright © 2012 John Wiley & Sons, Ltd.
The hippocampal physiology of approaching middle‐age: Early indicators of change
Authors: Huxter John R. , Miranda Jason A. , Dias Rebecca
Published: June 2012

Age‐related cognitive decline presents serious lifestyle challenges, and anatomical changes to the hippocampus are often implicated in clinical conditions later in life. However, relatively little is known about how hippocampal physiology is altered in the transition to middle‐age, when early detection may offer the best opportunity for successful treatment. High‐yield extracellular recording is a powerful tool for understanding brain function in freely moving animals at single‐cell resolution and with millisecond precision. We used this technique to characterize changes to hippocampal physiology associated with maturation in 35‐week‐old rats. Combining a series of behavioral tasks with recordings of large numbers of neurons, local field potentials (LFP), and network patterns of activation, we were able to generate a comprehensive picture based on more than 25 different assays for each subject. Notable changes associated with aging included increased firing rates in interneurons, reduced LFP power but increased frequency in the 4–12 Hz theta band, and impairment in hippocampal pattern‐separation for different environments. General properties of pyramidal cell firing and spatial map integrity were preserved. There was no impairment in theta phase‐precession, experience‐dependent place field expansion, or sleep reactivation of waking network patterns. There were however changes in foraging strategy and behavioral responses to the introduction of a novel environment. Taken together the results reveal a diverse pattern of changes which are of increasing relevance in an aging population. They also highlight areas where high‐yield electrophysiological assays can be used to provide the sensitivity and throughput required for pre‐clinical drug‐discovery programs. © 2012 Wiley Periodicals, Inc.
Impact and uncertainties of climate change on the hydrology of the Mara River basin, Kenya/Tanzania
Authors: Dessu Shimelis Behailu , Melesse Assefa Mekonnen
Published: June 2012

The impact and uncertainty of climate change on the hydrology of the Mara River basin (MRB) was assessed. Sixteen global circulation models (GCMs) were evaluated, and five were selected for the assessment of future climate scenarios in the basin. Observed rainfall and temperature data for the control period (1961–1990) were combined with expected GCMs output using the delta and direct statistical downscaling methods and three greenhouse gas emission scenarios (A1B, A2 and B1). Uncertainties of climate change were addressed through compare and contrast of results across diverse GCMs, future climate scenarios and the two downscaling methods. Both methods produced a relatively similar annual rainfall amount, but their monthly and daily pattern showed considerable differences. The relative advantages and disadvantages of implementing one method over the other were also explored. The hydrologic impact of climate change in the basin was assessed using Soil and Water Assessment Tool. The model was calibrated and validated with observed data in the control period with (Nash–Sutcliff efficiency, coefficient of determination) results of (calibration: 0.68, 0.69) and (validation: 0.43, 0.44) at Mara Mines. Results have shown a statistically significant increase in flow volume of the Mara River flow at Mara Mines for the year 2046–2065 and 2081–2100. With due attention to the limitations, findings of this study have a wider application for water resources sustainability analysis in the MRB in the face of uncertainties due to climate change. Copyright © 2012 John Wiley & Sons, Ltd.
Model structure exploration for index flood regionalization
Authors: Han Dawei , Jaafar Wan Zurina Wan
Published: June 2012

Although the nonlinear power form model structure is widely accepted by practitioners in the flood regionalization modelling, there is a lack of studies on whether there is a room for further improvement, and if the answer is yes, what should be done to explore alternative model structures. A framework is proposed in this study towards investigating this issue by the following steps: (i) a universal data‐driven model is utilized to see if there is a room for improvement compared with the conventional model, and (ii) if improvement is achieved, this means that there should exist more effective model structures than the current form. However, because the universal data‐driven models are usually opaque, more explicit model structures should be explored, which are convenient for practical usage. In this study, the proposed framework is applied in a case study using the catchment characteristics from the Flood Estimation Handbook in conjunction with the gamma test, support vector machine (SVM) and genetic programming (GP). First, the gamma test is used for the purpose of input variables selection where no model structure needs to be defined as a priori, and therefore, the result can be applied to any model structures for model building. Second, an SVM, which is a powerful data‐driven nonlinear model capable of modelling a variety of nonlinear systems, is applied to the index flood model for the first time. Once the best model is determined using those two data‐driven tools, GP is employed to find an alternative model structure. As the SVM is not formulated for producing explicit model functional form, the GP offers an advantage at this point where it can infer an explicit mathematical model functional form. Copyright © 2012 John Wiley & Sons, Ltd.
Impacts of precipitation on the cryologic regime of stream channels
Authors: Turcotte Benoit , Morse Brian , Anctil François
Published: June 2012

This paper examines the controlling influence of snow and rain on river ice processes in creeks and streams. Winter precipitation (in the form of rain and snow) has been observed to affect river ice processes and channel parameters of low and high gradient channels in unsuspected ways that can have significant impacts on channel hydraulics, hydrology and habitat. On a low gradient stream, a snowfall event initiated the development of an ice cover by creating unconsolidated snow slush bridges that eventually froze in place. Afterward, both snowfalls and rainfalls in alternation with cold spells dramatically increased the thickening rate of the ice cover well beyond that predicted by classic equations. In a smaller low‐gradient agricultural creek, wind‐blown snow impeded the formation of an ice cover by insulating the flow from cold atmospheric conditions. On steep channels (of different sizes and morphologies), anchor snow slush has been seen to accumulate on the bed substrate. As opposed to anchor ice, anchor snow slush is not believed to require supercooling water conditions to form nor to stay in place. Finally, in a steep headwater creek, a rain‐on‐snow event generated a snow slush flow and multiple snow slush jams. This phenomenon was seen to divert most of the water out of the channel into another watershed and concomitantly signalled a mid‐winter breakup in the greater watershed downstream. These observations suggest that the role of precipitation on small channel winter ice morphology and water flows, levels and currents has been severely underestimated and that any ecological winter studies, hydraulic structure designs and river modelling efforts need to include processes that are sometimes dominated by rain, slush and snow. Copyright © 2012 John Wiley & Sons, Ltd.
Seasonal sediment fluxes forcing supraglacial melting on the Wright Lower Glacier, McMurdo Dry Valleys, Antarctica
Authors: MacDonell Shelley A. , Fitzsimons Sean J. , Mölg Thomas
Published: June 2012

Cold‐based glaciers exist in low temperature and low humidity environments in which shortwave radiation is the largest source of energy to the glacier surface and the energy budget is very sensitive to the surface albedo. Consequently, the presence of relatively low volumes of debris on glacier surfaces has a significant impact on the timing, magnitude and rate of ablation at the surface. The aim of this study is to understand how the presence of sediment on the glacier surface at the start of the melt season can affect meltwater generation and delivery on a cold‐based glacier. A combination of field measurements, energy balance modelling and chemical mixing modelling were used on the Wright Lower Glacier, McMurdo Dry Valleys, Antarctica, between October 2005 and January 2006 to address this aim. In this system, sediment was transported onto the glacier surface during the winter months (March–October) by foehn winds, which reduced surface albedo at the start of the summer melt season. The areas of the glacier on which sediment accumulated began to melt earlier than other parts of the glacier and experienced a longer melt season. Over the study period, the total ablation on the dirty surfaces was nine times greater than for clean ice. Ablation on the dirty surfaces is dominated by melting, whereas sublimation dominates the clean ice. As the sediment was unevenly distributed over the glacier surface, the variation in melt amount and timing drove the development of a cryoconite hole system. Copyright © 2012 John Wiley & Sons, Ltd.
Continental scale modelling of in‐stream river water quality: a report on methodology, test runs, and scenario application
Authors: Voß Anja , Alcamo Joseph , Bärlund Ilona , Voß Frank , Kynast Ellen , Williams Richard , Malve Olli
Published: June 2012

To address the continental and large‐scale aspects of water quality assessments, new modelling approaches are required. This paper describes the development of a continental‐scale model of river water quality – WorldQual. Simple equations, consistent with the availability of data on the continental‐scale, are used to simulate the response of biochemical oxygen demand (BOD5) and total dissolved solids (TDS) to anthropogenic loadings and flow dilution. A methodology is developed that is appropriate for scenario analysis on the continental and global scale. Average monthly river water quality is modelled on a 5 arcmin grid covering all Europe. Loadings are derived from assumptions about water use, return flows and other variables. The model WorldQual is tested against measured longitudinal gradients and time series data at specific river locations. The model performance on European scale shows that a good fit can be reached when using concentration classifications as a measure: For BOD5, 51% of the simulated data is in the same quality class as the measurements and 30% differ only by one water‐quality class; for TDS, the respective values are 35% and 41%. WorldQual was applied to investigate the impact of climate change on resulting changes of in‐stream concentrations. The results for Europe show that future climate changes only have a small impact on European in‐stream concentration levels of BOD5, except for the Eastern part and the Black Sea region. This effect is stronger for the IPCM4‐A2 scenario than for the MIMR‐A2 scenario. Copyright © 2012 John Wiley & Sons, Ltd.
BEYOND THE NUMBERS: MINING THE ANNUAL REPORTS FOR HIDDEN CUES INDICATIVE OF FINANCIAL STATEMENT FRAUD
Authors: Goel Sunita , Gangolly Jagdish
Published: June 2012

Unlike previous fraud detection research, a vast majority of which has focused primarily on the use of quantitative financial information to predict fraud, in this study we examine qualitative textual content in annual reports to predict fraud and see whether there are discernible differences in the writing and presentation style between companies that committed fraud and those that did not. We believe that while numeric financial information in the annual reports can hide details of fraud, textual information relating to writing and presentation styles in such reports provides valuable clues pertaining to the existence of fraud. In this study we use the chi‐square test to analyse our data and test hypotheses about predictors of fraud that may explain linguistic feature variations in fraudulent and nonfraudulent annual reports. We provide new results on the usefulness of the qualitative content of annual reports in detecting fraud. Copyright © 2012 John Wiley & Sons, Ltd.
Contribution of N : P ratio and endogenous phytohormones during development of phosphorus toxicity in Brassica campestris spp. parachinensis
Authors: Yang Xian , Gu Mengmeng , Kang Yunyan , Feng Xinfu
Published: June 2012

Agricultural practices may lead to excessive phosphorus (P) accumulation in soil. The effects of excessive P on Chinese flowering cabbage (Brassica campestris spp. parachinensis) were investigated by exposing plants for 4 weeks in solution containing 1, 2, 3, 5, and 7 mM NaH2PO4. Phosphorus concentrations [P] greater than 3 mM produced significantly stunted growth, together with reduced appearance quality due to overaccumulation of anthocyanin in the epidermis of flower stalk. Nitrate concentrations in the flower stalk decreased with increasing solution [P]. Nitrogen (N) concentrations in the roots and potassium (K) concentrations in the leaves, stems, and roots all decreased at [P] higher than 3 mM. Increasing P supply caused great enhancement of root and stem [P], but decreased total plant and root N : P ratios. A positive linear relationship between solution [P] and anthocyanin concentration and a negative linear relationship between root N : P ratio and anthocyanin concentration were also observed. In addition, 3 to 7 mM P caused decreased levels of indole‐3‐acetic acid (IAA) and gibberellin (GA3) in the leaves, but promoted ethylene production. The average gibberellin concentration was generally correlated with the plant's relative growth rates. Ethylene was negatively correlated with plant growth parameters except for the last day of the experiment. In conclusion, N : P ratio and endogenous phytohormones may be involved in the development of P toxicity in Chinese flowering cabbage plants.
Comparison of water‐retention functions obtained from the extended evaporation method and the standard methods sand/kaolin boxes and pressure plate extractor
Authors: Schindler Uwe , Mueller Lothar , da Veiga Milton , Zhang Yuming , Schlindwein Sandro , Hu Chunsheng
Published: June 2012

Knowledge of the soil hydraulic functions is required for various hydrological studies and for the simulation of water and solute fluxes in unsaturated soils. Sand/kaolin boxes are frequently used to determine these properties in the low‐tension range. For higher tensions the pressure plate extractor is mainly applied. The extended evaporation method allows a more efficient determination of the water‐retention curve in an adequate range. Besides this method enables to quantify simultaneously the unsaturated hydraulic‐conductivity function. The objective of this study was to compare the water‐retention curves obtained from the standard methods (STM) with those determined with the extended evaporation method (EEM). A set of 90 natural soil samples of different texture and origin was analyzed, and the agreement between the methods was statistically evaluated. The average water‐content deviation (AWCD) of all samples was 1.83 vol.%, and the root mean square error (RMSE) 2.08 vol.%. The deviation of soil water‐storage capacity in the pore‐size classes 0–6, 6–30, 30–500, 500–1500 kPa varied between minimum –0.17 and 0.25 vol.% and maximum –2.89 and 2.36 vol.%, and confirmed the good comparability among the adopted methods. Systematic deviations between the methods were not found.
Preoperative evaluation and management of the pancreatic head mass
Authors: Conrad Claudius , Fernández‐del Castillo Carlos
Published: June 2012

The differential diagnosis of a pancreatic head mass encompasses a wide range of clinical entities that include both solid and cystic lesions. This chapter focuses on our approach to the patient presenting with a newly found pancreatic head mass with the main goals of determining the risk of the lesion being malignant or premalignant, resectability if the patient is appropriate for surgical intervention, assessment of need for multimodality treatment and determination the patient's surgical risk. J. Surg. Oncol. 2013;107:23–32. © 2012 Wiley Periodicals, Inc.
Long‐term outcomes in patients with locally advanced rectal cancer treated with preoperative chemoradiation followed by curative surgical resection
Authors: Lim Seok‐Byung , Yu Chang Sik , Hong Yong Sang , Kim Tae Won , Kim Jong Hoon , Kim Jin Cheon
Published: June 2012

Objective

To determine the oncologic outcomes and clinical factors affecting survival in patients with locally advanced rectal cancer who underwent preoperative chemoradiotherapy (CRT) followed by curative surgical resection.

Methods

: We retrospectively analyzed outcomes in 581 patients who underwent preoperative CRT for advanced rectal cancer (T3/4 or node positive) followed by curative resection. All patients received preoperative radiation to the entire pelvis, at a total dose of 45–50.4 Gy in 20–25 fractions for 4–5 weeks, and 569 (97.9%) patients received concurrent chemotherapy with a 5‐FU based agent. All patients underwent a curative proctectomy, including total mesorectal excision, a median 6 weeks later, and 432 (74.4%) patients underwent sphincter‐saving surgery. Oncologic outcomes, including survival and recurrence, were evaluated according to pathologic parameters, and factors affecting survival were investigated.

Results

The 5‐year disease‐free and overall survival rates were 72.4% and 77.8%, respectively. Eighty‐nine patients (15.3%) had a pathologic complete response. Multivariate analysis showed that ypN category independently affected 5‐year overall survival rates (ypN0 88.0%; ypN1 55.1%; ypN2 47.1%; P < 0.001). Factors independently affecting 5‐year disease‐free survival (DFS) rates included ypN category (ypN0 84.5%; ypN1 44.2%; ypN2 34.9%; P < 0.001), tumor regression grade (TRG1 52.9%; TRG2 72.0%; TRG3 86.7%; TRG4 86.8%; P = 0.004) and surgical method (sphincter‐saving 76.3%; sphincter sacrificing 61.7%; P = 0.005).

Conclusion

Less advanced pathologic N‐stage is a significantly favorable prognostic factor for disease‐free and overall survival, with good response and sphincter saving surgery benefiting DFS. J. Surg. Oncol. 2012; 106:659–666. © 2012 Wiley Periodicals, Inc.
Etiologies, risk factors, and outcomes of bacterial pneumonia after living donor liver transplantation
Authors: Ikegami Toru , Shirabe Ken , Matono Rumi , Yoshizumi Tomoharu , Soejima Yuji , Uchiyama Hideaki , Kayashima Hiroto , Morita Kazutoyo , Maehara Yoshihiko
Published: June 2012

The prevalence and clinical characteristics of bacterial pneumonia after living donor liver transplantation (LDLT) have not yet been elucidated. We performed a retrospective analysis of 346 LDLT recipients. Fifty patients (14.5%) experienced bacterial pneumonia after LDLT, and they had a higher short-term mortality rate (42.0%) than patients with other types of bacterial infections after LDLT. Gram-negative bacteria accounted for 84.0% of the causative pathogens. A multivariate analysis showed that preoperative diabetes (P < 0.01), United Network for Organ Sharing status 1 or 2A (P < 0.01), and an operative blood loss > 10 L (P = 0.03) were significant risk factors for bacterial pneumonia after LDLT. Post-LDLT pneumonia was associated with the following post-LDLT events: the prolonged use of mechanical ventilation (≥3 days), a prolonged stay in the intensive care unit (≥7 days), the creation of a tracheostomy, primary graft dysfunction, the use of mycophenolate mofetil, and the need for renal replacement therapy. Among patients with bacterial pneumonia, the mortality rate was higher for patients with delayed-onset pneumonia, which occurred at least 10 days after transplantation (n = 15), and it was significantly associated with graft dysfunction. A combination of broad-spectrum antibiotics and aminoglycosides provided cover for most gram-negative bacteria except Stenotrophomonas maltophilia, which was associated with a longer period of mechanical ventilation and was resistant to commonly used broad-spectrum antibiotics. Delayed-onset bacterial pneumonia is a serious type of bacterial infection after LDLT and is frequently associated with graft dysfunction. The multidrug resistance of S. maltophilia is an issue that needs to be addressed. Liver Transpl, 2012. © 2012 AASLD.
Portopulmonary hypertension: An update
Authors: Safdar Zeenat , Bartolome Sonja , Sussman Norman
Published: June 2012

Portopulmonary hypertension (POPH) is a serious complication of cirrhosis that is associated with mortality beyond that predicted by the Model for End-Stage Liver Disease (MELD) score. Increased pulmonary vascular resistance (PVR) may be initiated by pulmonary vasoconstriction, altered levels of circulating mediators, or shear stress, and can eventually lead to the classic vascular remodeling (plexiform lesion) that characterizes POPH. Portal hypertension is a prerequisite for the diagnosis of POPH, although the severity of pulmonary hypertension is unrelated to the severity of portal hypertension or the nature or severity of liver disease. POPH precludes liver transplantation (LT) unless the mean pulmonary artery pressure (MPAP) can be reduced to a safe level. The concept of an acceptable pressure has changed: we now consider both MPAP and PVR in the diagnosis, and we include the transpulmonary pressure gradient so that we can factor in fluid overload and left ventricular failure. Pulmonary vasodilator therapy includes oral, inhaled, and parenteral agents, and one or more of these agents may significantly lower pulmonary artery pressures to the point that LT becomes possible. The United Network for Organ Sharing recommends MELD exception points for patients with medically controlled POPH, but this varies by region. Patients who undergo LT need specialized intraoperative and postoperative management, which includes the availability of intraoperative transesophageal echocardiography for assessing right ventricular function, and rapidly acting vasodilators (eg, inhaled nitric oxide and/or epoprostenol). Published case series suggest excellent outcomes after LT for patients who respond to medical therapy. Liver Transpl, 2012. © 2012 AASLD.
Characterization of Hindered Amine Light Stabilizers in Polymer Matrix Using Terahertz Time‐Domain Spectroscopy
Authors: Xie Ling‐Hai , Dai Hao , Jin Biao‐Bing , Han Yuan , Tai Qiang , Yi Ming‐Dong , Yang Tao , Wu Pei‐Heng , Huang Wei
Published: June 2012

Terahertz time‐domain spectroscopy (THz‐TDS) technique allows us to analyze plastic additives. A series of hindered amine light stabilizers (HALSs), including TMP, PMP, BB‐PMP, Chimassorb 944 and 119, and a nitroxide free radical of 4‐hydroxy‐2,2,6,6‐tetramethyl‐1‐piperidinyloxy (HTEMPO) in the matrix of high‐density polyethylene are characterized in the range of 0.2–2.6 THz. TMP, PMP, and BB‐PMP exhibit individual well‐resolved terahertz (THz) absorption spectra at room temperature. Furthermore, a linear relationship of the content of TMP versus the intensity of it first THz absorption peak are demonstrated with the detection limit of about 1.6% (w/w). In addition, PMP exhibit water‐dependent characteristic THz absorption spectra. THz‐TDS will afford a potential tool to investigate the stabilizing mechanism of HALS and monitor their evolution.