bluuebunny/crossref_metadata_2025 huggingface dataset:
Energy‐efficient delay tolerant space time codes for asynchronous cooperative communications
Authors: Ashraf Mateen , Sohaib Sarmad
Published: January 2014

Cooperative communication protocols are generally assumed to be synchronous in nature, which is not always possible in distributed wireless networks. Lack of synchronisation may cause space time codes to lose their property of being full rank. The solution proposed, thus far, increase the size of the codes in the temporal that in turn increases the energy consumption and complexity of the receiver. In addition, the channel is required to be static over the length of codes, which is a hard condition when the size of the ST code increases. In order to mitigate these issues, we have proposed delay tolerant codes in this paper that do not increase receiver complexity and require less circuit energy. The simulation results for various delay profiles show that the proposed codes require less total energy per bit when relays are within a small range. Therefore, the proposed scheme is better suited to short‐range applications such as sensor networks. Copyright © 2014 John Wiley & Sons, Ltd.
Monte Carlo Simulation of the CGMY Process and Option Pricing
Authors: Ballotta Laura , Kyriakou Ioannis
Published: January 2014

We present a joint Monte Carlo‐Fourier transform sampling scheme for pricing derivative products under a Carr–Geman–Madan–Yor (CGMY) model (Carr et al. [Journal of Business, 75, 305–332, 2002]) exhibiting jumps of infinite activity and finite or infinite variation. The approach relies on numerical transform inversion with computable error estimates, which allow generating the unknown cumulative distribution function of the CGMY process increments at the desired accuracy level. We use this to generate samples and simulate the entire trajectory of the process without need of truncating the process small jumps. We illustrate the computational efficiency of the proposed method by comparing it to the existing methods in the literature on pricing a wide range of option contracts, including path‐dependent univariate and multivariate products. © 2014 Wiley Periodicals, Inc. Jrl Fut Mark 34:1095–1121, 2014
Maximal Gaussian Affine Models for Multiple Commodities: A Note
Authors: Casassus Jaime , Liu Peng , Tang Ke
Published: January 2014

This study extends the maximal affine models of single assets to a multi‐commodity setup. We show that the correlated version of maximal affine models for a single commodity is no longer maximal for multiple commodities. In the maximal model, the convenience yield of a certain commodity could depend on the prices of other commodities, which is consistent with the structural model in our companion study Casassus, Liu, and Tang [Review of Financial Studies, 26, 1324–1362, 2013]. This cross‐commodity relationship is a feedback effect that may generate substantial co‐movement among long‐run commodity prices, a fact that is consistent with many empirical studies. © 2014 Wiley Periodicals, Inc. Jrl Fut Mark 35:75–86, 2015
Younger age of dementia diagnosis in a Hispanic population in southern California
Authors: Fitten L. Jaime , Ortiz Freddy , Fairbanks Lynn , Bartzokis George , Lu Po , Klein Eric , Coppola Giovanni , Ringman John
Published: January 2014

Objective

Prior studies of US Hispanics, largely performed on the East Coast, have found a younger age of dementia onset than in White non‐Hispanics. We performed a cross‐sectional study to examine clinical and sociodemographic variables associated with age of dementia diagnosis in older Hispanics and White, non‐Hispanics in southern California.

Methods

Two hundred ninety (110 Hispanic and 180 White non‐Hispanic) community dwelling, cognitively symptomatic subjects, aged 50 years and older, were assessed and diagnosed with probable Alzheimer's disease or probable vascular dementia. Apolipoprotein E (APOE) genotype was assessed in a subset of cases. Analysis of variance and multiple stepwise linear regression were used to assess main effects and interactions of ethnicity with dementia severity (indexed by mini mental state examination scores) and other sociodemographic and clinical variables on age of dementia diagnosis.

Results

Hispanics were younger by an average of 4 years at the time of diagnosis, regardless of dementia subtype, despite a similar prevalence of the APOE ε4 genotype. The earlier age at diagnosis for Hispanics was not explained by gender, dementia severity, years of education, history of hypercholesterolemia, hypertension, or diabetes. Only ethnicity was significantly associated with age of onset.

Conclusions

These findings confirm that US Hispanics living in the southwestern USA tend to be younger at the time of dementia diagnosis than their White non‐Hispanic counterparts. As this is not explained by the presence of the APOE ε4 genotype, further studies should explore other cultural, medical, or genetic risk factors influencing the age of dementia onset in this population. Copyright © 2014 John Wiley & Sons, Ltd.
Bet‐hedging in diapausing egg hatching of temporary rotifer populations – A review of models and new insights
Authors: García‐Roger Eduardo M. , Serra Manuel , Carmona María José
Published: January 2014

Habitat unpredictability is a local adaptation factor shaping life‐history traits in rotifer populations. It may select for the evolution of bet‐hedging through risk‐spreading strategies in diapausing egg hatching. This means that a fraction of diapausing eggs in wild populations do not hatch even when the conditions are favorable for population growth. Thus, there is a remaining fraction of viable diapausing eggs standing in the sediments for longer periods. According to theory, it is expected that the incidence of bet‐hedging strategies for diapausing egg hatching will be higher in more uncertain habitats. Here, we review the major predictions derived from theoretical models applied to the case of monogonont rotifers. In the simplest “bad versus good season” models, the highest environmental uncertainty occurs when the probability of a good season is 0.5, and then the optimal hatching fraction is 0.5 too, implying maximum variance in hatching (i.e., maximum bet‐hedging). However, there is still little evidence to support this prediction. This is most likely due to the lack of long‐term data of habitat fluctuations and the difficulties in identifying and analyzing bet‐hedging strategies, as well as the potential to confound genetic variation and phenotypic plasticity. Moreover, we provide new evidence supporting the occurrence of bet‐hedging strategies associated with diapausing egg hatching in theBrachionus plicatilisspecies complex. Our analyses suggest a gradient of predictability in the habitats of these rotifers, and the existence of a significant positive correlation between the hatching fraction of diapausing eggs and an index of habitat predictability.
Characterization of the biochemical effects of naphthalene on the mouse respiratory system using NMR‐based metabolomics
Authors: Hong Jia‐Huei , Lee Wen‐Ching , Hsu Yu‐Ming , Liang Hao‐Jan , Wan Cho‐Hua , Chien Chung‐Liang , Lin Ching‐Yu
Published: January 2014

Naphthalene is a ubiquitous environmental pollutant to which humans are exposed. Previous studies have demonstrated that naphthalene causes bronchiolar epithelial necrosis in the mouse distal airway, after parenteral administration. In this study, metabolic variations in the bronchoalveolar lavage fluid (BALF) and the lung tissues of naphthalene‐treated mice and controls were examined using nuclear magnetic resonance (NMR)‐based metabolomics to identify the toxic mechanism. Male ICR mice were treated with naphthalene [0, 50, 100 and 200 mg kg–1, intraperitoneally (i.p.)]. After 24 h, BALF and lung tissues were collected and prepared for 1H and J‐resolved (JRES) NMR analysis after principal component analysis (PCA). PCA modeling of p‐JRES spectra from the BALF, as well as hydrophilic and hydrophobic lung metabolites, enabled the high‐dose group to be discriminated from the control group; increased levels of isopropanol, ethane, and acetone and lower levels of ethanol, acetate, formate, and glycerophosphocholine were detected in the BALF of mice treated with higher doses of naphthalene. Furthermore, increased isopropanol and phosphorylcholine‐containing lipid levels and decreased succinate and glutamine levels were discovered in the lungs of naphthalene‐exposed mice. These metabolic changes may be related to lipid peroxidation, disruptions of membrane components and imbalanced energy supply, and these results may partially explain the loss of cell membrane integrity in the airway epithelial cells of naphthalene‐treated mice. We conclude that NMR‐based metabolomic studies on BALF and lung tissues are a powerful tool to understand the mechanisms underlying respiratory toxicity. Copyright © 2014 John Wiley & Sons, Ltd.
The effect of diesel exhaust exposure on blood–brain barrier integrity and function in a murine model
Authors: Heidari Nejad Sayeh , Takechi Ryusuke , Mullins Benjamin J. , Giles Corey , Larcombe Alexander N. , Bertolatti Dean , Rumchev Krassi , Dhaliwal Satvinder , Mamo John
Published: January 2014

Epidemiological studies indicate that exposure to diesel exhaust (DE) is associated with vascular‐based disorders. To investigate the effect of DE on blood–brain barrier (BBB) function and integrity, 8‐week‐old BALB/c mice were randomized to DE in a cyclical treatment regimen over a 2‐week period. Functional integrity of BBB was determined by considering brain parenchymal abundance of IgG within the hippocampal formation and cortex at 6 h and 24 h intervals following final exposure treatment. Neurovascular inflammation was expressed as the abundance of glial fibrillar acidic protein. Two doses of DE were studied and compared to air‐only treated mice. Mice exposed to DE had substantially greater abundance of parenchymal IgG compared to control mice not exposed to DE. Increased parenchymal glial fibrillar acidic protein at 24 h post‐DE exposure suggested heightened neurovascular inflammation. Our findings are proof‐of‐concept that inhalation of DE can compromise BBB function and support the broader contention that DE exposure may contribute to neurovascular disease risk. Copyright © 2014 John Wiley & Sons, Ltd.
Phosphorylation‐Regulated Degradation of the Tumor‐Suppressor Form of PED by Chaperone‐Mediated Autophagy in Lung Cancer Cells
Authors: Quintavalle Cristina , Di Costanzo Stefania , Zanca Ciro , Tasset Immaculada , Fraldi Alessandro , Incoronato Mariarosaria , Mirabelli Peppino , Monti Maria , Ballabio Andrea , Pucci Piero , Cuervo Ana Maria , Condorelli Gerolama
Published: January 2014

PED/PEA‐15 is a death effector domain (DED) family member with a variety of effects on cell growth and metabolism. To get further insight into the role of PED in cancer, we aimed to find new PED interactors. Using tandem affinity purification, we identified HSC70 (Heat Shock Cognate Protein of 70 kDa)—which, among other processes, is involved in chaperone‐mediated autophagy (CMA)—as a PED‐interacting protein. We found that PED has two CMA‐like motifs (i.e., KFERQ), one of which is located within a phosphorylation site, and demonstrate that PED is a bona fide CMA substrate and the first example in which phosphorylation modifies the ability of HSC70 to access KFERQ‐like motifs and target the protein for lysosomal degradation. Phosphorylation of PED switches its function from tumor suppression to tumor promotion, and we show that HSC70 preferentially targets the unphosphorylated form of PED to CMA. Therefore, we propose that the up‐regulated CMA activity characteristic of most types of cancer cell enhances oncogenesis by shifting the balance of PED function toward tumor promotion. This mechanism is consistent with the notion of a therapeutic potential for targeting CMA in cancer, as inhibition of this autophagic pathway may help restore a physiological ratio of PED forms. J. Cell. Physiol. 229: 1359–1368, 2014. © 2014 Wiley Periodicals, Inc.
Midbrain Cues Dictate Differentiation of Human Dental Pulp Stem Cells Towards Functional Dopaminergic Neurons
Authors: Kanafi Mohammad , Majumdar Debanjana , Bhonde Ramesh , Gupta Pawan , Datta Indrani
Published: January 2014

Dental pulp originating from the neural crest is considered a better source of postnatal stem cells for cell‐based therapies in neurodegenerative diseases. Dental Pulp Stem Cells (DPSCs) have been shown to differentiate into cell‐types of cranial neural crest ontology; however, their ability to differentiate to functional neurons of the central nervous system remains to be studied. We hypothesized that midbrain cues might commit DPSCs to differentiate to functional dopaminergic cell‐type. As expected, DPSCs in their naïve state spontaneously expressed early and mature neuronal markers like nestin, musashi12, β tubulin III, and Map2ab. On exposure to midbrain cues (sonic hedgehog, fibroblast growth factor 8 and basic fibroblast growth factor), DPSCs showed upregulation of dopaminergic neuron‐specific transcription factors Nuclear Receptor related protein 1 (Nurr1), Engrailed 1 (En1) and paired‐like homeodomain transcription factor 3 (Pitx3) as revealed by real‐time RT‐PCR. Immunofluorescence and flow cytometry analysis showed enhanced expression of mature neuronal marker Map2ab and dopaminergic‐neuronal markers [tyrosine hydroxylase (TH), En1, Nurr1, and Pitx3], with nearly 77% of the induced DPSCs positive for TH. Functional studies indicated that the induced DPSCs could secrete dopamine constitutively and upon stimulation with potassium chloride (KCl) and adenosine triphosphate (ATP), as measured by dopamine ELISA. Additionally, the induced DPSCs showed intracellular Ca2+ influx in the presence of KCl, unlike control DPSCs. ATP‐stimulated Ca2+ influx was observed in control and induced DPSCs, but only the induced cells secreted dopamine. Our data clearly demonstrate for the first time that DPSCs in the presence of embryonic midbrain cues show efficient propensity towards functional dopaminergic cell‐type. J. Cell. Physiol. 229: 1369–1377, 2014. © 2014 Wiley Periodicals, Inc.
Comparison of spermatozoa parameters, fine structures, and energy‐related factors among tetraploid, hyper‐tetraploid, and hyper‐triploid loaches (Misgurnus anguillicaudatus)
Authors: Zhao Yan , Saito Taiju , Pšenička Martin , Fujimoto Takafumi , Arai Katsutoshi
Published: January 2014

To evaluate the influence of ploidy elevation and aneuploidy on spermatozoa in the loach Misgurnus anguillicaudatus, we investigated some parameters (motility, concentration, and viability), fine structures (gross morphology, head size, and flagellum length), and energy‐related biochemical factors (volume of mitochondrial mass per cell and ATP content) in diploid, hyper‐diploid, and hexaploid‐range spermatozoa produced in natural tetraploid, hyper‐tetraploid, and hyper‐triploid male loaches, respectively. Diploid spermatozoa exhibited vigorous movement and sufficient duration of motility similar to those in haploid spermatozoa. They had longer flagella, higher numbers and larger volume of mitochondria, and higher ATP content than haploid spermatozoa of wild‐type diploids. No differences were observed in parameters and morphological characteristics between diploid and hyper‐diploid spermatozoa. In contrast, the hexaploid‐range spermatozoa of hyper‐triploid males exhibited poor progressive motility in spite of a higher ATP content of spermatozoa. Spermatozoa with no flagella (36.0%) or multiple flagella (18.6%) were also observed in hyper‐triploids. Ratios of head to flagellum length in hexaploid‐range spermatozoa were significantly different from those of haploid spermatozoa. In addition to the normal 9 + 2 microtubule structure of the flagellum, an abnormal 9 + 1 microtubule structure was also observed in the spermatozoa of hyper‐triploids. J. Exp. Zool. 321A: 198–206, 2014. © 2014 Wiley Periodicals, Inc.
Improved Synthesis and Reaction of 11‐Chloroneocryptolepines, Strategic Scaffold for Antimalaria Agent, and Their 6‐Methyl Congener from Indole‐3‐carboxylate
Authors: Wang Li , Lu Wen‐Jie , Odawara Tomohito , Misumi Ryuhei , Mei Zhen‐Wu , Peng Wei , El‐Sayed Ibrahim El‐Tantawy , Inokuchi Tsutomu
Published: January 2014

Various 11‐chloro‐5‐methyl‐5H‐indolo[2,3‐b]quinolines (neocryptolepines) with different substituents on the quinoline ring, key intermediates for antimalaria agents, are prepared from the substituted N‐methylanilines, easily accessible by the N‐methylation of anilines, and indole‐3‐carboxylate as a counterpart. This protocol is benign in terms of the reduced number of steps to reach the target, compared with the known method using anilines, and easy product purification. Alternatively, their 6‐methyl congener is prepared by N‐methylation of the indole moiety of 2‐arylaminoindole‐3‐carboxylate followed by successive cyclization and chlorination. 11‐Chloroneocryptolepines are found more reactive than their 6‐methyl congener in the nucleophilic substitution at the C11 position.
Cycloadducts of Furan with Arynes Generated from 2‐Bromo‐1,4,5,8‐tetramethoxynaphthalene and 2,6‐Dibromo‐1,4,5,8‐tetramethoxynaphthalene
Authors: Tanoue Yasuhiro , Kai Norihisa , Nagai Takeshi , Ushio Kazutoshi
Published: January 2014

The reaction of 2‐bromo‐1,4,5,8‐tetramethoxynaphthalene (7) with sodium amide (or LDA) in the presence of a large excess of furan gave the epoxy compound 9. The similar reaction of 2,6‐dibromo‐1,4,5,8‐tetramethoxynaphthalene (8) afforded the diepoxy compound 10. The crystal structure of antidiepoxide 10 was determined by an X‐ray crystallography.
Reactions of Nucleophilic Substitution in Bicyclic Nitroimidazodihydrooxazoles
Authors: Żwawiak Justyna , Zaprutko Lucjusz
Published: January 2014

This article describes numerous attempts of the SN reaction of chlorine atom in chloromethyl group with nucleophilic compounds, such as the following: phenols, thiophenols, and amino compounds. The influences of ratios of nitroimidazodihydrooxazoles, nucleophiles and basic agent, and the polarity of solvent on the kind of formed products were established. Also, the comparison of reactivity with nucleophiles of close structural isomers of nitroimidazodihydrooxazoles has been made. The way of formation ring opening reaction products has been proposed.
Oxidation of 2,9‐Diphenyl‐1,10‐phenanthroline to Generate the 5,6‐Dione and Its Subsequent Alkylation Product
Authors: Lehnig Ammon P. , Lazorski Megan S. , Mingroni Michael , Pacheco Kimberly A. O. , Michael Elliott C.
Published: January 2014

One group of ligands used in transition metal complexes is synthesized by derivatizing 1,10‐phenanthroline. These metal complexes are of interest for study in the field of photovoltaic devices and solar fuels. Previous strategies for obtaining the 5,6‐diones of substituted 1,10‐phenanthrolines do not work for 2,9‐diphenyl‐1,10‐phenanthroline due to undesired products resulting from oxidation of the phenyl substituents. However, 2,9‐diphenyl‐1,10‐phenanthroline‐5,6‐dione can be obtained in reasonable yield by oxidation with BrO3− in weak aqueous acid. The resulting dione can be converted directly to the 5,6‐dialkoxy product upon two electron reduction in aprotic solvent followed by treatment with appropriate alkylating agents.
New Route of Benzyne Cyclization for Synthesis of 2,3,4,5‐Tetrahydro‐1H‐pyrido[4,3‐b]indole Derivatives Avoiding Highly Toxic Aryl Hydrazines
Authors: Kovacikova Lucia , Stefek Milan
Published: January 2014

A new route for the regioselective synthesis of 2,3,4,5‐tetrahydro‐1H‐pyrido[4,3‐b]indole derivatives was developed based on cyclization of 3‐chlorophenylimine‐N‐alkyl‐4‐piperidones by “the complex bases” of NaNH2 or KNH2. The procedure was performed under variable reaction conditions in inert proton‐free solvents, such as THF, dioxane, 1,2‐dimethoxyethane, toluene, and xylene, at temperatures varying from 20°C to boiling point of the solvent used. Toxic arylhydrazine intermediates occurring in the classical Fischer indole synthesis are avoided.
Motion‐compensated real‐time MR thermometry augmented by tracking coils
Authors: Wang Peng , Unal Orhan
Published: January 2014

Purpose

To develop and evaluate a real‐time proton resonant frequency (PRF) based MR thermometry method with a novel motion compensation technique, using linear phase model and active tracking coils.

Materials and Methods

A 6F catheter with multiple tracking coils and radiofrequency (RF) ablation tip was built for ex vivo experiments using excised bovine liver on a 1.5 Tesla scanner. A real‐time MR acquisition scheme with interleaved active catheter tracking and multislice imaging was implemented. To evaluate the proposed method, in‐plane periodic linear motion and through‐plane irregular motion were induced by the rocker capability of the scanner and hand, respectively. Real‐time temperature maps of the tissue undergoing a 2‐min RF ablation cycle were obtained and used to compare the performance of the proposed method with that of the multi‐baseline method.

Results

The temporal window achieved per acquisition of one slice and catheter tracking is ∼380 ms. The standard deviations of tracking errors are less than 1 mm for both irregular and periodic motions in x–y plane. The measurements at the heated and unheated regions demonstrate that the proposed thermometry method perform equally well for both in‐plane and through‐plane motion while maintaining a similar accuracy (σ = 1.10 versus 1.04°C) compared with the conventional multi‐baseline method.

Conclusion

The new MR thermometry method using catheter‐based tracking coils and linear phase model for motion compensation and phase correction is promising and may offer reliable MR thermometry for real‐time MRI‐guided thermal therapies. J. Magn. Reson. Imaging 2015;41:851–857. © 2014 Wiley Periodicals, Inc.
Electrochemical fabrication of a novel polycarbazole coating for the headspace solid‐phase microextraction and GC determination of some chlorobenzenes
Authors: Wang Meng , Zhao Fa‐Qiong , Zeng Bai‐Zhao
Published: January 2014

A novel polycarbazole coating was prepared by cyclic voltammetry on a platinum wire. The solution for electropolymerization contained N,N‐dimethylformamide, propylene carbonate (v/v = 1:9), 0.10 M carbazole and 0.10 M tetrabutylammonium perchlorate; the cyclic scan potential range was 0.8–2.0 V (versus Ag/AgCl). The resulting polycarbazole coating showed a porous structure and had a large specific surface area. When it was used for the headspace solid‐phase microextraction of chlorobenzenes (i.e. chlorobenzene, 2‐chlorotoluene, 1,2‐dichlorobenzene, 1,3‐dichlorobenzene, 1,2,4‐trichlorobenzene) followed by GC analysis, it presented excellent analytical performance. Under the optimized conditions the linear ranges were 0.25–250 μg/L with correlation coefficients >0.985, and the low detection limits were 15–61 ng/L (S/N = 3) for different chlorobenzenes. The RSDs were 2.4–4.9% for five successive measurements with a single fiber, and for fiber‐to‐fiber they were 6.3–13.1% (n = 5). Furthermore, the polycarbazole coating displayed good thermal stability (>350°C) and durability (more than 250 times). The proposed method was successfully applied to the extraction and determination of chlorobenzenes in waste water and lake water, and the recoveries for standards added were 86–114% for different analytes.
Determination of naproxen in human plasma by GC–MS
Authors: Yilmaz Bilal , Sahin Huseyin , Erdem Ali Fuat
Published: January 2014

This paper describes a GC–MS method for the determination of naproxen in human plasma. Naproxen and internal standard ibuprofen were extracted from plasma using a liquid–liquid extraction method. Derivatization was carried out using N‐methyl‐N‐(trimethylsilyl)trifluoroacetamide. The calibration curve was linear between the concentration range of 0.10–5.0 μg/mL. Intra‐ and interday precision values for naproxen in plasma were <5.14, and accuracy (relative error) was better than 4.67%. The extraction recoveries of naproxen from human plasma were between 93.0 and 98.9%. The LOD and LOQ of naproxen were 0.03 and 0.10 μg/mL, respectively. Also, this assay was applied to determine the pharmacokinetic parameters of naproxen in six healthy Turkish volunteers who had been given 220 mg naproxen.
Effect of the sol–gel route on the textural characteristics of silica imprinted with Rhodamine B
Authors: de Coelho Escobar Cícero , dos Santos João Henrique Zimnoch
Published: January 2014

A series of silica xerogels that support Rhodamine B as a template were synthesized using distinct sol–gel routes, namely, acid‐catalyzed routes, a base‐catalyzed route, acid‐catalyzed with base‐catalyzed (two steps) hydrolytic routes, and a FeCl3‐catalyzed nonhydrolytic route. The extraction methods (thermal, Soxhlet, water washing, and ultrasound) were also evaluated. The resulting xerogels were characterized through porosimetry using nitrogen adsorption/desorption. The samples were further analyzed through small‐angle X‐ray scattering, Fourier transform infrared spectroscopy, and SEM. The preparation route affected the materials’ textural properties. Extraction was optimized using acid and two‐step routes. The acid route from Rhodamine B to Rhodamine 6G generated the highest selectivity factor (2.5). The nonhydrolytic route produced the best imprinting factor. Competitive adsorption was also used, from which the approximate imprinting factor was 2. The cavity shape generated during the production of the imprinted silica dictates the adsorption behavior, not the magnitude of the surface area.
Conceptualising Customer‐to‐customer Value Co‐creation in Tourism
Authors: Rihova Ivana , Buhalis Dimitrios , Moital Miguel , Gouthro Mary‐Beth
Published: January 2014

The notion that tourists actively co‐create value with organisations is increasingly acknowledged in tourism marketing. Yet, not much is known about the processes in play when customers co‐create value with each other. This conceptual paper offers a theoretical basis for the study of customer‐to‐customer co‐creation in tourism contexts, while debating the epistemological assumptions of value‐related research in tourism. Proposed conceptual framework posits that value is socially constructed and embedded in tourists' social practices. Copyright © 2014 John Wiley & Sons, Ltd.
Survival and habitat use by fledgling northern flickers in a fragmented forest landscape
Authors: Gow Elizabeth A. , Wiebe Karen L.
Published: January 2014

The post‐fledging dependency period of birds is often characterized by high juvenile mortality, but fledglings in specific habitats may have increased survivorship. We describe habitat use by fledgling northern flickers (Colaptes auratus) in relation to the availability of patchy forest and prairie habitat in central British Columbia, Canada. We used radiotelemetry to monitor survival of fledglings according to their use of habitats during the dependency period. The fledglings occupied habitats with a higher density of trees than either random locations or nest sites and they switched from forested areas to more open grasslands after 7–10 days post‐fledging. Some moved >1 km from the nest within 4 days post‐fledging. Fledglings from nests in small tree clusters with little forest cover within 250 m moved farther from their nest within the first 4 days post‐fledging than fledglings from nests in larger forest patches. Fledgling survival was positively correlated with the amount of canopy cover and negatively correlated with the amount of forest cover at the larger landscape scale. Young flickers moved among habitat types, which may occur as a result of trade‐offs between predation risk and food abundance between habitats. We conclude that fledgling flickers at younger ages used dense forested areas and grassland habitat and forest at older ages to maximize survival and to access food sources. Maintaining patches of dense cover and the amount of forest cover on less than 35% of the landscape may improve fledgling survival of flickers. © 2014 The Wildlife Society.
Clinical implications of preoperative and intraoperative liver biopsies for evaluating donor steatosis in living related liver transplantation
Authors: Jun Mi-Jung , Shim Ju Hyun , Kim So Yeon , Seo Nieun , Kim Kang Mo , Lim Young-Suk , Lee Han Chu , Yu Eunsil , Lee Sung-Gyu
Published: January 2014

The role of liver biopsy in selecting optimal donors is an area of continuing controversy in living donor liver transplantation (LDLT). Our aim was to assess the potential implications of preoperative and intraoperative biopsies for evaluating donor liver fat content. Three thousand eight hundred fifty-nine consecutive subjects underwent predonation needle biopsy of the right lobe, and 1766 of these subjects actually donated their livers for LDLT and underwent intraoperative wedge biopsies of paired right and left lobes. The preoperative workup protocol also included abdominal ultrasonography (USG) and computed tomography (CT). Intersample agreement on steatosis grades (<5%, 5% to <15%, 15% to <30%, and ≥30%) was calculated, and clinicometabolic factors related to sampling variability were evaluated. For detecting ≥30% steatosis in the 3859 potential donors, USG and CT had sensitivities of 84.9% and 57.3%, specificities of 76.3% and 92.7%, positive predictive values of 29.6% and 48.0%, and negative predictive values of 97.7% and 94.8%, respectively. Analyses of the 1766 actual donors showed that with respect to the total steatosis grades of intraoperative right and left biopsies versus preoperative biopsy, 36.7% and 36.0% of the pairs, respectively, differed from the weighted κ values of 0.44 and 0.40. Similar agreement levels existed for macrovesicular and microvesicular steatosis subtypes. The per-subject agreement rate for the total steatosis grade between intraoperative right and left biopsies was 83.6%. According to a multivariate analysis, independent factors affecting the variability of the total steatosis results from preoperative and intraoperative biopsies (major features) were higher systolic blood pressure, body mass index, and alanine aminotransferase values and lower high-density lipoprotein cholesterol values. In conclusion, imaging may be insufficiently sensitive for evaluating donor hepatic steatosis. Preoperative and selective intraoperative liver biopsies are mandatory for assessing donor steatosis in LDLT unless preoperative imaging demonstrates no fat. Liver Transpl 20:437–445, 2014. © 2014 AASLD.
Pregnancy outcomes after living donor liver transplantation: Results from a Japanese survey
Authors: Kubo Shoji , Uemoto Shinji , Furukawa Hiroyuki , Umeshita Koji , Tachibana Daisuke
Published: January 2014

A national survey of pregnancy outcomes after living donor liver transplantation (LDLT) was performed in Japan. Thirty-eight pregnancies in 30 recipients resulted in 31 live births (25 recipients), 3 artificial abortions in the first trimester (3 recipients), 1 spontaneous abortion (1 recipient), and 3 fetal deaths (3 recipients). After the exclusion of the 3 artificial abortions, there were 35 pregnancies in 27 recipients: pregnancy-induced hypertension developed during 6 pregnancies (5 recipients), fetal growth restriction developed during 7 pregnancies (6 recipients), acute rejection developed during 2 pregnancies (2 recipients), and ileus developed during 1 pregnancy (1 recipient). Preterm delivery (<37 weeks) occurred for 10 pregnancies (10 recipients), and cesarean delivery was performed for 12 pregnancies (12 recipients). After delivery, acute rejection developed in 3 recipients. Twelve neonates were born with low birth weights (<2500 g), and 4 of these 12 neonates had extremely low birth weights (<1500 g). Two neonates had congenital malformations. The pregnancy outcomes after LDLT were similar to those reported for cadaveric liver transplantation (LT). The incidence of pregnancy-induced hypertension in recipients who were 33 years old or older at the diagnosis of pregnancy was significantly higher than the incidence in recipients who were less than 33 years old at the diagnosis of pregnancy. The incidences of fetal growth restriction, pregnancy-induced hypertension, and extremely low birth weight were significantly higher in the early group (<3 years after transplantation) versus the late group (≥3 years after transplantation). In conclusion, it is necessary to pay careful attention to complications during pregnancy in recipients who become pregnant within 3 years of LT, particularly if the age at the diagnosis of pregnancy is ≥33 years. Liver Transpl 20:576-583, 2014. © 2014 AASLD.
Development and validation of the Diagnostic Interview Adjustment Disorder (DIAD)
Authors: Cornelius L. R. , Brouwer S. , de Boer M. R. , Groothoff J. W. , van der Klink J. J. L.
Published: January 2014

Adjustment disorders (ADs) are under‐researched due to the absence of a reliable and valid diagnostic tool. This paper describes the development and content/construct validation of a fully structured interview for the diagnosis of AD, the Diagnostic Interview Adjustment Disorder (DIAD). We developed the DIAD by partly adjusting and operationalizing DSM‐IV criteria. Eleven experts were consulted on the content of the DIAD. In addition, the DIAD was administered by trained lay interviewers to a representative sample of disability claimants (n = 323). To assess construct validity of the DIAD, we explored the associations between the AD classification by the DIAD and summary scores of the Kessler Psychological Distress 10‐item Scale (K10) and the World Health Organization Disability Assessment Schedule (WHODAS) by linear regression. Expert agreement on content of the DIAD was moderate to good. The prevalence of AD using the DIAD with revised criteria for the diagnosis AD was 7.4%. The associations of AD by the DIAD with average sum scores on the K10 and the WHODAS supported construct validity of the DIAD. The results provide a first indication that the DIAD is a valid instrument to diagnose AD. Further studies on reliability and on other aspects of validity are needed. Copyright © 2014 John Wiley & Sons, Ltd.
Developing an African youth psychosocial assessment: an application of item response theory
Authors: Betancourt Theresa S. , Yang Frances , Bolton Paul , Normand Sharon‐Lise
Published: January 2014

This study aimed to refine a dimensional scale for measuring psychosocial adjustment in African youth using item response theory (IRT). A 60‐item scale derived from qualitative data was administered to 667 war‐affected adolescents (55% female). Exploratory factor analysis (EFA) determined the dimensionality of items based on goodness‐of‐fit indices. Items with loadings less than 0.4 were dropped. Confirmatory factor analysis (CFA) was used to confirm the scale's dimensionality found under the EFA. Item discrimination and difficulty were estimated using a graded response model for each subscale using weighted least squares means and variances. Predictive validity was examined through correlations between IRT scores (θ) for each subscale and ratings of functional impairment. All models were assessed using goodness‐of‐fit and comparative fit indices. Fisher's Information curves examined item precision at different underlying ranges of each trait. Original scale items were optimized and reconfigured into an empirically‐robust 41‐item scale, the African Youth Psychosocial Assessment (AYPA). Refined subscales assess internalizing and externalizing problems, prosocial attitudes/behaviors and somatic complaints without medical cause. The AYPA is a refined dimensional assessment of emotional and behavioral problems in African youth with good psychometric properties. Validation studies in other cultures are recommended. Copyright © 2014 John Wiley & Sons, Ltd.
On the role of physiological fluctuations in quantitative gradient echo MRI: implications for GEPCI, QSM, and SWI
Authors: Wen Jie , Cross Anne H. , Yablonskiy Dmitriy A.
Published: January 2014

Purpose

Physiological fluctuations in biological tissues adversely affect MR images if present during signal acquisition. This problem is especially important for quantitative MRI. The goal of the studies reported in this study was to reduce the contributions of physiological fluctuations in quantitative MRI based on T2* tissue relaxation properties. Specifically, in this study we deal with GEPCI, QSM, and SWI techniques and propose methods allowing for substantial improvement of their results.

Methods

We used a navigator imbedded in a multi‐gradient‐echo sequence to record and correct MR signal phase fluctuations at each phase encoding step. All GEPCI, QSM, and SWI images were then reconstructed from a single acquisition. We used a keyhole‐type approach to further average out effects of physiological fluctuations. Voxel spread function technique was used to correct for macroscopic field inhomogeneities.

Results

Brains of normal subjects and subjects with multiple sclerosis were studied. We demonstrated that our used strategies substantially reduced the width of the R2* = 1/T2* distribution within human brains and significantly improved quantification of tissue damage in multiple sclerosis. We also showed improved quality of the SWI and QSM images.

Conclusion

The strategies used in this study greatly reduced physiologically induced artifacts in GEPCI, QSM, and SWI, improving the reliability of these techniques. Magn Reson Med 73:195–203, 2015. © 2014 Wiley Periodicals, Inc.
Determination of vagal baroreflex sensitivity in normal subjects
Authors: Wada Naoki , Singer Wolfgang , Gehrking Tonette L. , Sletten David M. , Schmelzer James D. , Kihara Mikihiro , Low Phillip A.
Published: January 2014

Introduction: The Valsalva maneuver (VM) is used widely to quantify the sensitivity of the vagal baroreflex loop (vagal baroreflex sensitivity, BRS_v), but most studies have focused on the heart rate (HR) response to blood pressure (BP) decrement (BRS_v↓), even though the subsequent response to an increment in BP after the VM (BRS_v↑) is important and different. Methods: We evaluated recordings of HR and BP in 187 normal subjects during the VM and determined both BRS_v↑, as determined by relating HR to the BP increase after phase III and BRS_v↓. Results: BRS_v↑ was related inversely to age. In addition, BRS_v↓, age, and magnitude of phase IV were independent predictors of BRS_v↑ in a multivariate model, accounting for 47% of the variance of BRS_v↑. Conclusions: The results indicate that both BRS_v↑ and BRS_v↓ become blunted with increasing age and that these indices relate to each other. Muscle Nerve 50: 535–540, 2014
Acute and chronic ataxic neuropathies with disialosyl antibodies: A continuous clinical spectrum and a common pathophysiological mechanism
Authors: Yuki Nobuhiro , Uncini Antonino
Published: January 2014

Acute ataxic neuropathies with disialosyl antibodies include Fisher syndrome, ataxic Guillain–Barré syndrome (GBS), and acute sensory ataxic neuropathy. Fisher syndrome and ataxic GBS are more strongly associated with IgG anti‐GQ1b and anti‐GT1a than with anti‐GD1b antibodies, whereas the association is reversed in the case of acute sensory ataxic neuropathy. Chronic ataxic neuropathy with disialosyl antibodies is associated with IgM paraprotein to GD1b and GQ1b, which occasionally reacts with GT1a. The clinical, electrophysiological, and pathological features, along with experimental findings, suggest that acute and chronic ataxic neuropathies with disialosyl antibodies form a continuous clinical and pathophysiological spectrum characterized by a complement‐mediated disruption at the nodal region and are better classified in the new category of nodo‐paranodopathies. Muscle Nerve 49: 629–635, 2014
B‐bar FEMs for anisotropic elasticity
Authors: Oberrecht S.P. , Novák J. , Krysl P.
Published: January 2014

Anisotropic elastic materials, such as the homogenized model of a fiber‐reinforced matrix, can display near rigidity under certain applied stress–the resulting strains are small compared with the strains that would occur for other stresses of comparable magnitude. The anisotropic material could be rigid under hydrostatic pressure if the material were incompressible, as in isotropic elasticity, but also for other stresses.

Some commonly used finite elements are effective in dealing with incompressibility, but are ill‐equipped to handle materials that lock under non‐hydrostatic stress states (e.g., uniformly reduced serendipity and Q1/Q0 B‐bar hexahedra). The failure of the original B‐bar method is attributed to the assumption that the mode of deformation to be relieved is one of near incompressibility. The remedy proposed here is based on the spectral decomposition of the compliance matrix of the material. The spectrum can be interpreted to separate nearly‐rigid and flexible modes of stress and strain, which leads naturally to a generalized selective reduced integration. Furthermore, the spectral decomposition also enables a three‐field elasticity formulation that results in a B‐bar method that is effective for general anisotropic materials with an arbitrary nearly‐rigid mode of deformation.Copyright © 2014 John Wiley & Sons, Ltd.
Two‐scale computational modelling of water flow in unsaturated soils containing irregular‐shaped inclusions
Authors: Carr E. J. , Turner I. W.
Published: January 2014

The focus of this paper is two‐dimensional computational modelling of water flow in unsaturated soils consisting of weakly conductive disconnected inclusions embedded in a highly conductive connected matrix. When the inclusions are small, a two‐scale Richards’ equation‐based model has been proposed in the literature taking the form of an equation with effective parameters governing the macroscopic flow coupled with a microscopic equation, defined at each point in the macroscopic domain, governing the flow in the inclusions. This paper is devoted to a number of advances in the numerical implementation of this model. Namely, by treating the micro‐scale as a two‐dimensional problem, our solution approach based on a control volume finite element method can be applied to irregular inclusion geometries, and, if necessary, modified to account for additional phenomena (e.g. imposing the macroscopic gradient on the micro‐scale via a linear approximation of the macroscopic variable along the microscopic boundary). This is achieved with the help of an exponential integrator for advancing the solution in time. This time integration method completely avoids generation of the Jacobian matrix of the system and hence eases the computation when solving the two‐scale model in a completely coupled manner. Numerical simulations are presented for a two‐dimensional infiltration problem. Copyright © 2014 John Wiley & Sons, Ltd.
Glioblastoma‐associated stromal cells (GASCs) from histologically normal surgical margins have a myofibroblast phenotype and angiogenic properties
Authors: Clavreul Anne , Guette Catherine , Faguer Rogatien , Tétaud Clément , Boissard Alice , Lemaire Laurent , Rousseau Audrey , Avril Tony , Henry Cécile , Coqueret Olivier , Menei Philippe
Published: January 2014

Glioblastoma (GB) displays diffusely infiltrative growth patterns. Dispersive cells escape surgical resection and contribute to tumour recurrence within a few centimeters of the resection cavity in 90% of cases. We know that the non‐neoplastic stromal compartment, in addition to infiltrative tumour cells, plays an active role in tumour recurrence. We isolated a new stromal cell population from the histologically normal surgical margins of GB by computer‐guided stereotaxic biopsies and primary culture. These GB‐associated stromal cells (GASCs) share phenotypic and functional properties with the cancer‐associated fibroblasts (CAFs) described in the stroma of carcinomas. In particular, GASCs have tumour‐promoting effects on glioma cells in vitro and in vivo. Here, we describe a quantitative proteomic analysis, using iTRAQ labelling and mass spectrometry, to compare GASCs with control stromal cells derived from non‐GB peripheral brain tissues. A total of 1077 proteins were quantified and 67 proteins were found to differ between GASCs and control stromal cells. Several proteins changed in GASCs are related to a highly motile myofibroblast phenotype, and to wound healing and angiogenesis. The results for several selected proteins were validated by western blotting or flow cytometry. Furthermore, the effect of GASCs on angiogenesis was confirmed using the orthotopic U87MG glioma model. In conclusion, GASCs, isolated from GB histologically normal surgical margins and found mostly near blood vessels, could be a vascular niche constituent establishing a permissive environment, facilitating angiogenesis and possibly colonization of recurrence‐initiating cells. We identify various proteins as being expressed in GASCs: some of these proteins may serve as prognostic factors for GB and/or targets for anti‐glioma treatment. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd
Dyserythropoiesis in a child with pyruvate kinase deficiency and coexistent unilateral multicystic dysplastic kidney
Authors: Haija Marwa Abu El , Qian You‐Wen , Muthukumar Akila
Published: January 2014

Pyruvate kinase (PK) deficiency is the commonest enzyme deficiency in the glycolytic pathway leading to hemolytic anemia secondary to decreased Adenosine Triphosphate (ATP) synthesis in the red cells. synthesis. PK deficiency due to mutations in the PKLR (1q21) gene leads to highly variable clinical presentation ranging from severe fetal anemia to well compensated anemia in adults. We describe dyserythropoiesis in the bone marrow of a child with transfusion dependent anemia and unilateral multicystic dysplastic kidney (MCDK) mimicking Congenital Dyserythropoietic Anemia type I (CDA type I). Persistently low erythrocyte PK levels and double heterozygous mutations present in the PKLR gene confirmed the diagnosis of PK deficiency. Pediatr Blood Cancer 2014; 61:1463–1465. © 2014 Wiley Periodicals, Inc.
Long‐term outcome of 4,040 children diagnosed with pediatric low‐grade gliomas: An analysis of the Surveillance Epidemiology and End Results (SEER) database
Authors: Bandopadhayay Pratiti , Bergthold Guillaume , London Wendy B. , Goumnerova Liliana C. , Morales La Madrid Andres , Marcus Karen J. , Guo Dongjing , Ullrich Nicole J. , Robison Nathan J. , Chi Susan N. , Beroukhim Rameen , Kieran Mark W. , Manley Peter E.
Published: January 2014

Background

Children with pediatric low‐grade gliomas (PLGG) are known to have excellent 10‐year survival rates; however the outcomes of adult survivors of PLGG are unknown. We identified patients diagnosed with PLGG diagnosed between 1973 and 2008 through the Surveillance Epidemiology and End Results (SEER) database to examine outcomes of adult survivors of PLGG.

Procedure

Four thousand and forty patients with either WHO grade I or II PLGG were identified and outcome data retrieved. Two analyses were performed to assess survival and risk of death from tumor. Competing risks analysis was conducted and cumulative incidence curves of death due to disease were generated. Cox proportional hazards regression was performed, with adjustment for non‐disease death. Kaplan–Meier curves for overall cancer specific survival (OS) were also generated.

Results

The 20‐year OS was 87% ± 0.8% and the 20‐year cumulative incidence of death due to glioma was 12% ± 0.8%. The incidence of death after transition to adulthood (age greater than 22 years) was slightly lower, with 20‐year cumulative incidence of disease death of 7% ± 1.8%. Year of diagnosis, age of diagnosis, histology, WHO grade, primary site, radiation, and degree of initial resection were prognostic in univariate analysis, while the administration of radiation was the greatest risk of death in multivariate analysis of OS (hazard ratio = 3.9).

Conclusions

PLGGs are associated with an excellent long‐term survival, with a low likelihood of PLGG related death in adult survivors. Treatment strategies for pediatric tumors should therefore aim for disease control during childhood and adolescence with an emphasis on minimizing long‐term treatment induced toxicities. Pediatr Blood Cancer 2014;61:1173–1179. © 2014 The Authors. Pediatric Blood & Cancer Published by Wiley Periodicals, Inc.