bluuebunny/crossref_metadata_2025 huggingface dataset:
Predicting Hip Fracture Type With Cortical Bone Mapping (CBM) in the Osteoporotic Fractures in Men (MrOS) Study
Authors: Treece Graham M , Gee Andrew H , Tonkin Carol , Ewing Susan K , Cawthon Peggy M , Black Dennis M , Poole Kenneth ES ,   ; for the Osteoporotic Fractures in Men (MrOS) Study
Published: May 2015

Hip fracture risk is known to be related to material properties of the proximal femur, but fracture prediction studies adding richer quantitative computed tomography (QCT) measures to dual-energy X-ray (DXA)-based methods have shown limited improvement. Fracture types have distinct relationships to predictors, but few studies have subdivided fracture into types, because this necessitates regional measurements and more fracture cases. This work makes use of cortical bone mapping (CBM) to accurately assess, with no prior anatomical presumptions, the distribution of properties related to fracture type. CBM uses QCT data to measure the cortical and trabecular properties, accurate even for thin cortices below the imaging resolution. The Osteoporotic Fractures in Men (MrOS) study is a predictive case-cohort study of men over 65 years old: we analyze 99 fracture cases (44 trochanteric and 55 femoral neck) compared to a cohort of 308, randomly selected from 5994. To our knowledge, this is the largest QCT-based predictive hip fracture study to date, and the first to incorporate CBM analysis into fracture prediction. We show that both cortical mass surface density and endocortical trabecular BMD are significantly different in fracture cases versus cohort, in regions appropriate to fracture type. We incorporate these regions into predictive models using Cox proportional hazards regression to estimate hazard ratios, and logistic regression to estimate area under the receiver operating characteristic curve (AUC). Adding CBM to DXA-based BMD leads to a small but significant (p < 0.005) improvement in model prediction for any fracture, with AUC increasing from 0.78 to 0.79, assessed using leave-one-out cross-validation. For specific fracture types, the improvement is more significant (p < 0.0001), with AUC increasing from 0.71 to 0.77 for trochanteric fractures and 0.76 to 0.82 for femoral neck fractures. In contrast, adding DXA-based BMD to a CBM-based predictive model does not result in any significant improvement. © 2015 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals, Inc. on behalf of the American Society for Bone and Mineral Research.
Short-Term Effect of Estrogen on Human Bone Marrow Fat
Authors: Limonard Eelkje J , Veldhuis-Vlug Annegreet G , van Dussen Laura , Runge Jurgen H , Tanck Michael W , Endert Erik , Heijboer Annemieke C , Fliers Eric , Hollak Carla E , Akkerman Erik M , Bisschop Peter H
Published: May 2015

Bone marrow fat, an unique component of the bone marrow cavity increases with aging and menopause and is inversely related to bone mass. Sex steroids may be involved in the regulation of bone marrow fat, because men have higher bone marrow fat than women and clinical observations have suggested that the variation in bone marrow fat fraction is greater in premenopausal compared to postmenopausal women and men. We hypothesized that the menstrual cycle and/or estrogen affects the bone marrow fat fraction. First, we measured vertebral bone marrow fat fraction with Dixon Quantitative Chemical Shift MRI (QCSI) twice a week during 1 month in 10 regularly ovulating women. The vertebral bone marrow fat fraction increased 0.02 (95% CI, 0.00 to 0.03) during the follicular phase (p = 0.033), and showed a nonsignificant decrease of 0.02 (95% CI, –0.01 to 0.04) during the luteal phase (p = 0.091). To determine the effect of estrogen on bone marrow fat, we measured vertebral bone marrow fat fraction every week for 6 consecutive weeks in 6 postmenopausal women before, during, and after 2 weeks of oral 17-β estradiol treatment (2 mg/day). Bone marrow fat fraction decreased by 0.05 (95% CI, 0.01 to 0.09) from 0.48 (95% CI, 0.42 to 0.53) to 0.43 (95% CI, 0.34 to 0.51) during 17-β estradiol administration (p < 0.001) and increased again after cessation. During 17-β estradiol administration the bone formation marker procollagen type I N propeptide (P1NP) increased (p = 0.034) and the bone resorption marker C-terminal crosslinking telopeptides of collagen type I (CTx) decreased (p < 0.001). In conclusion, we described the variation in vertebral bone marrow fat fraction among ovulating premenopausal women. And among postmenopausal women, we demonstrated that 17-β estradiol rapidly reduces the marrow fat fraction, suggesting that 17-β estradiol regulates bone marrow fat independent of bone mass. © 2015 American Society for Bone and Mineral Research.
Involvement of PRIP (Phospholipase C‐Related But Catalytically Inactive Protein) in BMP‐Induced Smad Signaling in Osteoblast Differentiation
Authors: Kotani Miho , Matsuda Miho , Murakami Ayako , Takahashi Ichiro , Katagiri Takenobu , Hirata Masato
Published: May 2015

Phospholipase C‐related but catalytically inactive protein (PRIP) was first isolated as an inositol 1,4,5‐trisphosphate binding protein. We generated PRIP gene‐deficient mice which exhibited the increased bone mineral density and trabecular bone volume, indicating that PRIP is implicated in the regulation of bone properties. In this study, we investigated the possible mechanisms by which PRIP plays a role in bone morphogenetic protein (BMP) signaling, by analyzing the culture of primary cells isolated from calvaria of two genotypes, the wild type and a mutant. In the mutant culture, enhanced osteoblast differentiation was observed by measuring alkaline phosphatase staining and activity. The promoter activity of Id1 gene, responding immediately to BMP, was also more increased. Smad1/5 phosphorylation in response to BMP showed an enhanced peak and was more persistent in mutant cells, but the dephosphorylation process was not different between the two genotypes. The luciferase assay using calvaria cells transfected with the Smad1 mutated as a constitutive active form showed increased transcriptional activity at similar levels between the genotypes. The expression of BMP receptors was not different between the genotypes. BMP‐induced phosphorylation of Smad1/5 was robustly decreased in wild type cells, but not in mutant cells, by pretreatment with DB867, an inhibitor of methyltransferase of inhibitory Smad6. Furthermore, BMP‐induced translocation of Smad6 from nucleus to cytosol was not much observed in PRIP‐deficient cells. These results indicate that PRIP is implicated in BMP‐induced osteoblast differentiation by the negative regulation of Smad phosphorylation, through the methylation of inhibitory Smad6. J. Cell. Biochem. 116: 2814–2823, 2015. © 2015 Wiley Periodicals, Inc.
Involvement of a P2X7 Receptor in the Acrosome Reaction Induced by ATP in Rat Spermatozoa
Authors: Torres‐Fuentes Jorge L. , Rios Mariana , Moreno Ricardo D.
Published: May 2015

The acrosome reaction (AR) is the exocytosis of the acrosomal vesicle in response to different physiological and non‐physiological stimuli. Particularly in mammals, the AR is needed for sperm to fuse with the oocyte plasma membrane, and it occurs only in capacitated sperm. Previous evidence in the literature indicates that extracellular ATP induces the AR in capacitated human and bovine spermatozoa, but its receptor has not yet been identified. The aim of this work was to define a putative ATP receptor in rat spermatozoa using pharmacological and biochemical approaches. We found that ATP induced the AR only in capacitated rat spermatozoa, which was inhibited in the presence of two general inhibitors of ATP receptors (P2 receptors), Suramin, and oxidized ATP (oATP), and one inhibitor of P2X receptor (pyridoxalphosphate‐6‐azophenyl‐2′,4′‐disulfonic acid [PPADS]). In addition, the AR induced by ATP in capacitated rat spermatozoa was inhibited by brilliant blue‐G (BB‐G) and 17‐β‐oestradiol, two blockers of P2X7 receptors. Moreover, the ATP analog 2′(3′)‐O‐(4‐benzoylbenzoyl) ATP (BzATP) was almost 500 times more potent than ATP to induce the AR, which agrees with the pharmacology of a P2X7 receptor. Here, we show the presence of P2X7 receptor by Western blot and its localization in the tail and acrosome by indirect immunofluorescence. Finally, we quantify the presence of ATP in the rat oviduct during the estrous cycle. We found that the ATP concentration within the lumen of the oviduct is similar to those required to induce acrosome reaction, which agree with its role during in vivo fertilization. Therefore, our results strongly suggest that ATP induces the AR in capacitated rat spermatozoa through a P2X7 receptor, which may be functional during in vivo fertilization. J. Cell. Physiol. 230: 3068–3075, 2015. © 2015 Wiley Periodicals, Inc.
New challenges for syngas fermentation: towards production of biopolymers
Authors: Drzyzga Oliver , Revelles Olga , Durante‐Rodríguez Gonzalo , Díaz Eduardo , García José L , Prieto Auxiliadora
Published: May 2015

Organic wastes are a suitable feedstock for the production of value‐added products that have been insufficiently exploited due to their complexity, which challenges their transformation by conventional procedures. Gasification and pyrolysis of organic wastes can reduce this complexity by producing syngas (CO plus H2 and other C1 gases), which can be used as a valuable commodity by catalytic conversion into chemicals. However, the high cost and susceptibility to poisoning of chemical catalysts have encouraged research on biocatalysts that convert C1 components of syngas into different multi‐carbon compounds. Nowadays, research on syngas fermentation is receiving much attention in order to enhance the productivity of microorganisms by remodeling their metabolism and by optimizing the bioreactor operational conditions. This review highlights the new technical achievements of pyrolysis as well as the new biotechnological uses of syngas for the production of bulk chemicals and biopolymers, discussing the major bottlenecks that challenge syngas fermentation. © 2015 Society of Chemical Industry
Perfect Matchings Avoiding Several Independent Edges in a Star‐Free Graph
Authors: Egawa Yoshimi , Furuya Michitaka
Published: May 2015

In Aldred and Plummer (Discrete Math 197/198 (1999) 29–40) proved that every m‐connected ‐free graph of even order has a perfect matching M with and , where F1 and F2 are prescribed disjoint sets of independent edges with and . It is known that if l satisfies , then the star‐free condition in the above result is best possible. In this paper, for , we prove a refinement of the result in which the condition is replaced by the weaker condition that G is ‐free (note that the new condition does not depend on l). We also show that if m is even and either or , then for m‐connected graphs G with sufficiently large order, one can replace the condition by the still weaker condition that G is ‐free. The star‐free conditions in our results are best possible.
The Cross‐Level Mediating Effect of Psychological Capital on the Organizational Innovation Climate–Employee Innovative Behavior Relationship
Authors: Hsu Michael L. A. , Chen Forrence Hsinhung
Published: May 2015

Organizational innovation climates have been found to be effective predictors of employee creativity and organizational innovation. As such, climate assessments provide a basis for useful organizational interventions in enhancing creativity and innovation. Researchers now call for better articulation of the motivational mechanisms that link social context to employee innovation. In responding to the above call, this study found that employee positive psychological capital (PsyCap) is more influential than organizational innovation climate on employee innovative behavior. With a large sample (N = 781) from 16 organizations and a cross‐level analysis, we examined the relationship between organizational innovation climate and employee innovative behavior with employee PsyCap as mediator. The results showed that both organizational innovation climate and employee PsyCap significantly affect employee innovative behavior, and more importantly, employee PsyCap fully mediates this relationship. The innovation journey is a challenging and risky one with many frustrations and discouraging moments from idea generation to idea implementation. The research results presented here imply that to be innovatively effective, organizations are advised to manage both social (organizational innovation climate) and psychological (PsyCap) resources of employees in enhancing employee innovative behavior. Other theoretic and practical implications are discussed.
Biomechanical gait features associated with hip osteoarthritis: Towards a better definition of clinical hallmarks
Authors: Meyer Christophe A.G. , Corten Kristoff , Fieuws Steffen , Deschamps Kevin , Monari Davide , Wesseling Mariska , Simon Jean‐Pierre , Desloovere Kaat
Published: May 2015

Critical appraisal of the literature highlights that the discriminative power of gait‐related features in patients with hip osteoarthritis (OA) has not been fully explored. We aimed to reduce the number of gait‐related features and define the most discriminative ones comparing the three‐dimensional gait analysis of 20 patients with hip osteoarthritis (OA) with those of 17 healthy peers. First, principal component analysis was used to reduce the high‐dimensional gait data into a reduced set of interpretable variables for further analysis, including tests for group differences. These differences were indicative for the selection of the top 10 variables to be included into linear discriminant analysis models (LDA). Our findings demonstrated the successful data reduction of hip osteoarthritic‐related gait features with a high discriminatory power. The combination of the top variables into LDA models clearly separated groups, with a maximum misclassification error rate of 19%, estimated by cross‐validation. Decreased hip/knee extension, hip flexion and internal rotation moment were gait features with the highest discriminatory power. This study listed the most clinically relevant gait features characteristics of hip OA. Moreover, it will help clinicians and physiotherapists understand the movement pathomechanics related to hip OA useful in the management and design of rehabilitation intervention. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1498–1507, 2015.
Genetic loci that regulate ectopic calcification in response to knee trauma in LG/J by SM/J advanced intercross mice
Authors: Rai Muhammad Farooq , Schmidt Eric J. , Hashimoto Shingo , Cheverud James M. , Sandell Linda J.
Published: May 2015

This study reports on genetic susceptibility to ectopic calcification in the LG/J and SM/J advanced intercross mice. Using 347 mice in 98 full‐sibships, destabilization of medial meniscus (DMM) was performed to induce joint injury. We found that joint destabilization instigated ectopic calcifications as detected and quantified by micro‐CT. We performed quantitative trait locus (QTL) analysis to map ectopic calcification phenotypes to discrete genomic locations. To validate the functional significance of the selected QTL candidate genes, we compared mRNA expression between parental LG/J and SM/J inbred strains. Overall, we detected 20 QTLs affecting synovial and meniscus calcification phenotypes with 11 QTLs linked to synovial calcification. Functional and bioinformatic analyses of single nucleotide polymorphism (SNP) identified functional classifications relevant to angiogenesis (Myo1e, Kif26b, Nprl3, Stab2, Fam105b), bone metabolism/calcification (Tle3, Tgfb2, Lipc, Nfe2l1, Ank, Fam105b), arthritis (Stab2, Tbx21, Map4k4, Hoxb9, Larp6, Col1a2, Adam10, Timp3, Nfe2l1, Trpm3), and ankylosing‐spondylitis (Ank, Pon1, Il1r2, Tbkbp1) indicating that ectopic calcification involves multiple mechanisms. Furthermore, the expression of 11 out of 78 candidate genes was significantly different between LG/J and SM/J. Correlation analysis showed that Aff3, Fam81a, Syn3, and Ank were correlated with synovial calcification. Taken together, our findings of multiple genetic loci suggest the involvement of multiple genes contributing to ectopic calcification. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1412–1423, 2015.
Purification of transferrin by magnetic immunoaffinity beads
Authors: Saçlıgil Dilara , Şenel Serap , Yavuz Handan , Denizli Adil
Published: May 2015

Immunoaffinity adsorbent for transferrin (Tf) purification was prepared by immobilizing anti‐transferrin (Anti‐Tf) antibody on magnetic monosizepoly(glycidyl methacrylate) beads, which were synthesized by dispersion polymerization technique in the presence of Fe3O4nanopowder and obtained with an average size of 2.0 μm. The magnetic poly(glycidyl methacrylate) (mPGMA) beads were characterized by Fourier transform infrared spectroscopy, swelling tests, scanning electron microscopy, electron spin resonance spectroscopy, thermogravimetric analysis and zeta sizing analysis. The density and swelling ratio of the beads were 1.08 g/cm3 and 52%, respectively. Anti‐Tf molecules were covalently coupled through epoxy groups of mPGMA. Optimum binding of anti‐Tf was 2.0 mg/g. Optimum Tf binding from aqueous Tf solutions was determined as 1.65 mg/g at pH 6.0 and initial Tf concentration of 1.0 mg/mL. There was no remarkable loss in the Tf adsorption capacity of immunoaffinity beads after five adsorption–desorption cycles. Tf adsorption from artificial plasma was also investigated and the purity of the Tf molecules was shown with gel electrophoresis studies.
Sampling considerations and assessment of Exetainer usage for measuring dissolved and gaseous methane and nitrous oxide in aquatic systems
Authors: Sturm Katrin , Keller‐Lehmann Beatrice , Werner Ursula , Raj Sharma Keshab , Grinham Alistair Robert , Yuan Zhiguo
Published: May 2015

Pre‐evacuated Exetainers are commonly used as measurement vials for the determination of methane (CH4) and nitrous oxide (N2O) concentrations in liquid and gaseous samples from aquatic environments. The impact of residual air in these Exetainers on measurement accuracy is assessed. Residual air pressure in commercially available, pre‐evacuated Exetainers varied between 0.071 ± 0.008 atm and 0.180 ± 0.031 atm in examined batches. This background contamination can lead to large errors when determining dissolved and gaseous CH4 and N2O concentrations particularly at low concentrations. A method for Exetainer pretreatment is suggested and verified, to reduce the residual CH4 and N2O. Vials are flushed (needle 30 G × 0.5″, 0.3 mm) with nitrogen gas (N2) for 5 min, which reduces the background CH4 and N2O concentrations to 0.092 ± 0.008 ppm and 0.016 ± 0.001 ppm, respectively, approximately 3–4% of their respective concentrations in air. To avoid an alteration of sample concentration by variable residual gas levels left during a pre‐evacuation step, liquid and gaseous samples are injected into the N2 filled Exetainers. For gaseous samples where large volumes of gas are available, Exetainers can alternatively be flushed with 100 mL of sampling gas. For gaseous samples, measured CH4 and N2O concentrations of standard gases were statistically identical to their known concentrations. For liquid samples, measured CH4 and N2O concentrations of liquid standard dilution series showed strong linear correlations with theoretically calculated concentrations (slope CH4: 1.04, slope N2O: 1.12). Sample concentrations remained constant over a minimum storage period of 6 weeks.
On the invariant spectrum on
Authors: Hajli Mounir
Published: May 2015

Motivated by the work of Abreu and Freitas , we study the invariant spectrum of the Laplace operator associated to hermitian line bundles endowed with invariant metrics over .
Plasma‐based ambient ionization mass spectrometry in bioanalytical sciences
Authors: Smoluch Marek , Mielczarek Przemyslaw , Silberring Jerzy
Published: May 2015

Plasma‐based ambient ionization mass spectrometry techniques are gaining growing interest due to their specific features, such as the need for little or no sample preparation, its high analysis speed, and the ambient experimental conditions. Samples can be analyzed in gas, liquid, or solid forms. These techniques allow for a wide range of applications, like warfare agent detection, chemical reaction control, mass spectrometry imaging, polymer identification, and food safety monitoring, as well as applications in biomedical science, e.g., drug and pharmaceutical analysis, medical diagnostics, biochemical analysis, etc. Until now, the main drawback of plasma‐based techniques is their quantitative aspect, but a lot of efforts have been done to improve this obstacle. © 2015 Wiley Periodicals, Inc. Mass Spec Rev 35: 22–34, 2016.
Mind the gap—deficits in our knowledge of aspects impacting the bioavailability of phytochemicals and their metabolites—a position paper focusing on carotenoids and polyphenols
Authors: Bohn Torsten , McDougall Gordon J. , Alegría Amparo , Alminger Marie , Arrigoni Eva , Aura Anna‐Marja , Brito Catarina , Cilla Antonio , El Sedef N. , Karakaya Sibel , Martínez‐Cuesta Marie C. , Santos Claudia N.
Published: May 2015

Various secondary plant metabolites or phytochemicals, including polyphenols and carotenoids, have been associated with a variety of health benefits, such as reduced incidence of type 2 diabetes, cardiovascular diseases, and several types of cancer, most likely due to their involvement in ameliorating inflammation and oxidative stress. However, discrepancies exist between their putative effects when comparing observational and intervention studies, especially when using pure compounds. These discrepancies may in part be explained by differences in intake levels and their bioavailability. Prior to exerting their bioactivity, these compounds must be made bioavailable, and considerable differences may arise due to their matrix release, changes during digestion, uptake, metabolism, and biodistribution, even before considering dose‐ and host‐related factors. Though many insights have been gained on factors affecting secondary plant metabolite bioavailability, many gaps still exist in our knowledge. In this position paper, we highlight several major gaps in our understanding of phytochemical bioavailability, including effects of food processing, changes during digestion, involvement of cellular transporters in influx/efflux through the gastrointestinal epithelium, changes during colonic fermentation, and their phase I and phase II metabolism following absorption.
T1 and T2 values of human neonatal blood at 3 Tesla: Dependence on hematocrit, oxygenation, and temperature
Authors: Liu Peiying , Chalak Lina F. , Krishnamurthy Lisa C. , Mir Imran , Peng Shin‐lei , Huang Hao , Lu Hanzhang
Published: May 2015

Purpose

Knowledge of blood T1 and T2 is of major importance in many applications of MRI in neonates. However, to date, there has not been a systematic study to examine neonatal blood T1/T2 relaxometry. This present study aims to investigate this topic.

Methods

Using freshly collected blood samples from human umbilical cord, we performed in vitro experiments under controlled physiological conditions to measure blood T1 and T2 at 3 Tesla (T) and their dependence on several factors, including hematocrit (Hct), oxygenation (Y) and temperature.

Results

The arterial T1 in neonates was 1825 ± 184 ms (Hct = 0.42 ± 0.08), longer than that of adult blood. Neonatal blood T1 was strongly dependent on Hct (P < 0.001) and Y (P = 0.005), and the dependence of T1 on Y was more prominent at higher Hct. The arterial T2 of neonatal blood was 191 ms at an Hct of 0.42, which was also longer than adult blood. Neonatal blood T2 was positively associated with blood oxygenation and negatively associated with hematocrit level, and can be characterized by an exchange model. Neonatal blood T1 was also positively associated with temperature (P < 0.001).

Conclusion

The values provided in this report may provide important reference and calibration information for sequence optimization and quantification of in vivo neonatal MRI studies. Magn Reson Med 75:1730–1735, 2016. © 2015 Wiley Periodicals, Inc.
Influence of muscle fiber orientation on water and metabolite relaxation times, magnetization transfer, and visibility in human skeletal muscle
Authors: MacMillan Erin Leigh , Bolliger Christine Sandra , Boesch Chris , Kreis Roland
Published: May 2015

Purpose

To gain a deeper understanding of the influence of skeletal muscle fiber orientation on metabolite visibility, magnetization transfer from water, and water proton relaxation rates in 1H MR spectra.

Methods

Non–water‐suppressed MR spectroscopy was performed in tibialis anterior muscle (TA) of 10 healthy adults, with the TA oriented either parallel or at the magic angle to the 3T field. Spectra were acquired with metabolite‐cycled PRESS, and water inversion from 50 to 2510 ms before excitation. Water proton T2 relaxation was sampled with STEAM with echo times from 12 to 272 ms.

Results

Apparent concentrations of total creatine (tCr), taurine, and trimethylammonium compounds were reduced by 29% to 67% when TA was parallel to B0. Both tCr peak areas were strongly correlated to the methylene peak splitting. Magnetization transfer rates from water to tCr CH3 were not significantly different between orientations. Water T1s were similar between orientations, but T2s were statistically significantly shorter by 1 ms in the parallel orientation (P = 0.002).

Conclusion

Muscle metabolite visibilities in MR spectroscopy and water T2 times depend substantially on muscle fiber orientation relative to B0. In contrast, magnetization transfer rates appear to depend on muscle composition, rather than fiber orientation. Magn Reson Med 75:1764–1770, 2016. © 2015 Wiley Periodicals, Inc.
Modelling and performance analysis of application‐aware resource management
Authors: Wamser Florian , Blenk Andreas , Seufert Michael , Zinner Thomas , Kellerer Wolfgang , Tran‐Gia Phuoc
Published: May 2015

Application‐aware resource management is the approach to tailor access networks to have characteristics beneficial for the running applications and services. This is achieved through the monitoring and integration of key performance indicators from the application layer within the network resource management. The aim is to increase user‐perceived quality and network resource efficiency by traffic engineering with the help of these indicators. Using analytic and simulative approaches, this paper provides analysis methods for network operators to quantify the performance gains of alternative resource allocation algorithms that implement the application‐aware concept. Network operators can use the proposed methods to evaluate possible performance gain trade‐offs between investing in a pure capacity increase (over‐provisioning) and the realization of an application‐aware resource allocation. For this purpose, we model and analyse the application quality trade‐offs of four algorithms for application‐aware resource management at a single link in varying traffic situations. The algorithms are chosen with respect to different complexity and implementation level in order to cover the design space in a systematic way. The study of the algorithms focuses on the application‐layer performance for the most used applications today, namely, web browsing and video streaming with constant bit rate as well as hypertext transfer protocol progressive streaming with variable bit rate. Application quality trade‐offs are analysed in particular for a high‐resource utilization at a bottleneck link. The results confirm that application‐aware resource management outperforms best‐effort resource management in terms of quality of experience. Moreover, our study provides guidelines for the selection and configuration of the evaluated algorithms. Copyright © 2015 John Wiley & Sons, Ltd.
AT&T's establishment of a political capability
Authors: Brown Richard S.
Published: May 2015

The literature on corporate political activity has become robust in the last decade as scholars model the antecedents to, as well as the results of, for‐profit firms political strategies. The literature lacks, however, a practical guide to the specific activities that firms undertake in order to compete in such a manner. This case study follows the political activities at AT&T from 2000 to 2012 in the United States in order to clarify these specific activities. Copyright © 2015 John Wiley & Sons, Ltd.
Preparation of coatings from a series of silicone/fluorine‐functionalized polyacrylates via electrophoretic deposition
Authors: Yao Weiming , Wang Zhengping , Wu Xu , Li Bingbing , Zhong Ximing , Lin Jing , Chen Jingyuan , Lai Yanghong
Published: May 2015

Silicone/fluorine‐functionalized polyacrylates were synthesized and subsequently used to prepare corrosion‐resistant transparent coatings via electrophoretic deposition. The coated tin plate with the functionalized polyacrylate had a gloss value higher than 95.0 GU and resisted rust after immersion in a 5 wt% NaCl solution for 10 days. In addition, these coatings remained adhered strongly to the tin plates even after they were bent. It is hoped that this work will provide useful experimental data and assist researchers with the design of applicable coatings with desirable properties. Copyright © 2015 John Wiley & Sons, Ltd.
Soft‐lithographically fabricated nanofluidic channels for single‐DNA measurements
Authors: Sperling Evgeni , Hohlfeld Mandy , Mertig Michael
Published: May 2015

We report on the fabrication of submicrometer wide channels by applying advanced soft lithography and focused ion beam patterning. Using so‐called hard PDMS, mechanically stable channels are obtained down to 375 nm width. Channels down to ∼100 nm width are made from Ormostamp. The channels can be filled with DNA solution. Manipulation of the DNA transport through the channels is accomplished by applying electrophoretic forces.
Recent Advances and Future Directions for Quality Engineering
Authors: Vining Geoff , Kulahci Murat , Pedersen Søren
Published: May 2015

The origins of quality engineering are in manufacturing, where quality engineers apply basic statistical methodologies to improve the quality and productivity of products and processes. In the past decade, people have discovered that these methodologies are effective for improving almost any type of system or process, such as financial, health care, and supply chains.

This paper begins with a review of key advances and trends within quality engineering over the past decade. The second part uses the first part as a foundation to outline new application areas for the field. It also discusses how quality engineering needs to evolve in order to make significant contributions to these new areas. © 2015 The Authors Quality and Reliability Engineering International Published by John Wiley & Sons Ltd.
Optimized Karatsuba squaring on 8‐bit AVR processors
Authors: Seo Hwajeong , Liu Zhe , Choi Jongseok , Kim Howon
Published: May 2015

Multi‐precision squaring is one of the performance‐critical operations for implementation of elliptic curve cryptography. This paper continues the line of research on high‐speed multi‐precision squaring on embedded processors. In particular, we present an optimized Karatsuba squaring method for 8‐bit AVR processors. We compute the multiplication part with the fastest Karatsuba multiplication, and then the remaining two squaring parts are conducted with the fastest sliding block doubling squaring. As a result, The proposed method sets the new speed records for multi‐precision squaring, improving the execution time by up to 8.49% compared with the best known works. Copyright © 2015 John Wiley & Sons, Ltd.
Thinking about U: Theorizing and testing U‐ and inverted U‐shaped relationships in strategy research
Authors: Haans Richard F. J. , Pieters Constant , He Zi‐Lin
Published: May 2015

Research summary:U‐ and inverted U‐shaped relationships are increasingly explored in strategy research, with 11 percent of all articles published in Strategic Management Journal (SMJ) in 2008–2012 investigating such quadratic relationships. Moreover, a movement towards introducing moderation to quadratic relationships has emerged. By reviewing 110 articles published in SMJ from 1980 to 2012, we identify several critical issues in theorizing and testing of these relationships for which current practice falls short. These include insufficient causal argumentation, incorrect testing, mixing up two different types of moderation, and not realizing that the curve can flip completely. For these and other issues, a guideline is provided which, when followed, may bring clarity to theoretical motivation and rigor to empirical testing.

Managerial summary:Too much can be as bad as too little. Many relationships in strategic management follow an inverted U‐shaped pattern, where moderate levels of a strategy lead to optimal performance. To gain deeper insights into the conventional wisdom that too much of a good thing can be harmful to performance, we discuss how such relationships can be better theorized and tested based on a review of articles exploring U‐shaped relationships in Strategic Management Journal during 1980–2012. We identify several critical issues that require close attention and provide a guideline to further develop and validate this important managerial intuition. Copyright © 2015 John Wiley & Sons, Ltd.
An Architectural Approach to Requirements Engineering for Infrastructure Projects
Authors: Silmon Joe , Evans Rhianne , Brownsword Mike , Nicholson David
Published: May 2015

A brand‐new high‐speed railway project such as HS2, currently under development in the United Kingdom, presents a requirements engineering problem that is similar to domains where Systems Engineering (SE) is more traditionally applied, such as an aircraft, but with some differences in system structure that preclude a direct mapping of routine techniques. With over 300 separate elements of design in the Country South portion of the route, fitting into roughly 20 categories and inheriting requirements at multiple levels, including location‐specific constraints, it was considered necessary to implement a model‐based solution to provide an adequate level of technical assurance by managing the requirements and their links to the design elements. A database tool with diagramming capability was used to create a visual traceability structure between the client's original requirements and the refined requirements. A layered model of the system architecture was used to apply requirements to the correct sets of individual design elements. From this combined requirements and architecture model, spreadsheet checklists were generated for designers to perform verification. The resulting data were then re‐imported to the database and processed into a detailed report for submission to the client. The solution developed automates assignment of requirements traceability in order to provide exactly the right set of requirements for each deliverable on the route, which may consist of multiple asset types in differing combinations and with local requirements as well as more generic requirements assigned by equivalence.
Incentive‐Based Negotiation Model for System of Systems Acquisition
Authors: Kilicay‐Ergin Nil , Dagli Cihan
Published: May 2015

Lack of collaboration between individual systems and system of systems (SoS) program management is identified as one of the leading problems in SoS acquisition. This is especially a major concern in acknowledged SoS where a designated SoS program management has no authority over the constituent systems. Therefore, it is important to consider mechanisms to persuade individual systems to participate in the SoS development. In SoS where individual systems have their own self‐interests, negotiation becomes an important mechanism to increase participation in SoS development. Another mechanism, incentives, is used in a wide range of applications to improve performance and collaboration. In this paper, an incentive based negotiation model is outlined as a mechanism to increase participation of individual systems into the SoS development. The negotiation model is integrated into an SoS Engineering and Architecting multilevel model referred to as Flexible & Intelligent Learning Architectures for SoS (FILA‐SoS). Various aspects of SoS acquisition are modeled in the FILA‐SoS including SoS meta‐architecture generation, evaluation as well as negotiation between SoS and individual systems. Individual systems exhibit behaviors, ranging from selfish to cooperative. The negotiation model is demonstrated on an SoS engineering application: Intelligence, Surveillance, and Reconnaissance (ISR) SoS acquisition case where a desired meta‐architecture is selected for negotiation, and incentives are determined for systems based on deviation from the desired meta‐architecture quality. The analyses of the results from this application domain provide insights into how incentives can be used by decision makers to increase participation in SoS engineering and development.
Fetal umbilical–portal–systemic venous shunt: in‐utero classification and clinical significance
Authors: Achiron R. , Kivilevitch Z.
Published: May 2015

Objectives

To review our experience with fetal umbilical–portal–systemic venous shunts (UPSVS), to devise an in‐utero classification system, and to analyze their clinical and prognostic characteristics.

Methods

This was a retrospective review of cases of UPSVS examined at an academic tertiary referral center over the 14‐year period from 2001 to 2014 inclusive. The anatomical origin and drainage of the fetal umbilical, portal, ductus venosus and hepatic venous systems, and the integrity of the intrahepatic portal venous system (IHPVS), were assessed using two‐ and three‐dimensional color Doppler sonography. Fetomaternal clinical characteristics and long‐term outcome were investigated by means of medical files, imaging documentation and telephone interviews with the mothers.

Results

Forty‐four cases with UPSVS were reviewed. Prenatal classification was based on the anatomical origin of the shunt (umbilical, portal or ductal), with cases classified into four types: Type I, umbilical–systemic shunt (n = 9 (20.4%)); Type II, ductus venosus–systemic shunt (n = 19 (43.2%)); and Type III, portal–systemic shunt, divided into two subtypes: Type IIIa, intrahepatic portal–systemic shunt (n = 12 (27.2%)) and Type IIIb, extrahepatic portal–systemic shunt (n = 4 (9.1%)). Each type presented particular clinical and prognostic characteristics. The most important favorable prognostic factors were absence of associated major malformation and presence of the IHPVS. Thus, Type IIIa (intrahepatic portal–systemic shunt) had the best outcome.

Conclusions

Fetal UPSVS are anomalies with a broad spectrum of manifestations and prognoses. Accurate mapping of the IHPVS is paramount for optimizing prenatal counseling and postnatal care. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.
The activation strain model and molecular orbital theory
Authors: Wolters Lando P. , Bickelhaupt F. Matthias
Published: May 2015

The activation strain model is a powerful tool for understanding reactivity, or inertness, of molecular species. This is done by relating the relative energy of a molecular complex along the reaction energy profile to the structural rigidity of the reactants and the strength of their mutual interactions: ΔE(ζ) = ΔEstrain(ζ) + ΔEint(ζ). We provide a detailed discussion of the model, and elaborate on its strong connection with molecular orbital theory. Using these approaches, a causal relationship is revealed between the properties of the reactants and their reactivity, e.g., reaction barriers and plausible reaction mechanisms. This methodology may reveal intriguing parallels between completely different types of chemical transformations. Thus, the activation strain model constitutes a unifying framework that furthers the development of cross‐disciplinary concepts throughout various fields of chemistry. We illustrate the activation strain model in action with selected examples from literature. These examples demonstrate how the methodology is applied to different research questions, how results are interpreted, and how insights into one chemical phenomenon can lead to an improved understanding of another, seemingly completely different chemical process. WIREs Comput Mol Sci 2015, 5:324–343. doi: 10.1002/wcms.1221

This article is categorized under:

Structure and Mechanism > Molecular Structures
Propofol administration in patients with methylmalonic acidemia and intracellular cobalamin metabolism disorders: a review of theoretical concerns and clinical experiences in 28 patients
Authors: Ktena Yiouli P. , Ramstad Trygg , Baker Eva H. , Sloan Jennifer L. , Mannes Andrew J. , Manoli Irini , Venditti Charles P.
Published: May 2015

Background

Methylmalonic acidemia and intracellular cobalamin metabolism disorders represent a heterogeneous group of inborn errors of metabolism. Most patients will require diagnostic and/or therapeutic procedures frequently requiring sedation or anesthetic management due to neurological and neurocognitive impairments. It has been stated that propofol is contraindicated in this population. We report our experience with propofol administration in a large series of patients.

Methods

Twenty eight patients (14 mut, seven cblC, three cblA, three cblB, one cblG) aged 2–35.6 years enrolled in a natural history study (ClinicalTrials.gov identifier: NCT00078078) and required anesthetics for 39 diagnostic or therapeutic procedures. Data were collected on the anesthetic technique, perianesthetic course, and adverse events related to propofol.

Results

Propofol was used as the sole induction agent in most cases (36/39) and as the primary maintenance agent in all cases. Infusion rates were 100–400 mcg kg−1 min−1 (mean = 214). Infusion duration was 60–325 min (mean = 158) and total doses ranged between 270–3610 mg (mean = 1217). Adverse events were recorded in two cases; neither appeared to be related to propofol administration.

Conclusions

Propofol is an effective, safe induction and maintenance agent for elective short procedures requiring anesthesia in patients with MMA and cobalamin metabolism disorders. Despite multiple comorbidities and propensity toward instability, those affected can receive anesthesia with an acceptable safety profile, if metabolically and hemodynamically stabilized prior to the event.

Synopsis

A review of the perianesthetic records of 28 patients with isolated MMA and intracellular cobalamin metabolism disorders suggests that propofol anesthesia can be administered safely to these patients, in the setting of metabolic stability.
Use of 2H and 18O stable isotopes to investigate water sources for different ages of Populus euphratica along the lower Heihe River
Authors: Liu Shubao , Chen Yaning , Chen Yapeng , Friedman Jonathan M. , Hati Jarre Heng A. , Fang Gonghuan
Published: May 2015

Investigation of the water sources used by trees of different ages is essential to formulate a conservation strategy for the riparian tree, P. euphratica. This study addressed the contributions of different potential water sources to P. euphratica based on levels of stable oxygen and hydrogen isotopes (δ18O, δ2H) in the xylem of different aged P. euphratica, as well as in soil water and groundwater along the lower Heihe River. We found significant differences in δ18O values in the xylem of different aged P. euphratica. Specifically, the δ18O values of young, mature and over‐mature forests were −5.368(±0.252) ‰, −6.033(± 0.185) ‰ and −6.924 (± 0.166) ‰, respectively, reflecting the reliance of older trees on deeper sources of water with a δ18O value closer to that of groundwater. Different aged P. euphratica used different water sources, with young forests rarely using groundwater (mean <15 %) and instead primarily relying on soil water from a depth of 0–50 cm (mean >45 %), and mature and over‐mature forests using water from deeper than 100 cm derived primarily from groundwater.
Differentiation of regioisomeric chloroamphetamine analogs using gas chromatography–chemical ionization-tandem mass spectrometry
Authors: Negishi Shoko , Nakazono Yukiko , Iwata Yuko T. , Kanamori Tatsuyuki , Tsujikawa Kenji , Kuwayama Kenji , Yamamuro Tadashi , Miyamoto Kazuna , Yamashita Takuya , Kasuya Fumiyo , Inoue Hiroyuki
Published: May 2015

In recent years, a large number of clandestinely synthesized new psychoactive substances with high structural variety have been detected in forensic samples. Analytical differentiation of regioisomers is a significant issue in forensic drug analysis, because, in most cases, legal controls are placed on only one or two of the conceivable isomers. In this study, gas chromatography–tandem mass spectrometry (GC–MS–MS) was used to differentiate the regioisomers of chloroamphetamine analogs (chloroamphetamines and chloromethamphetamines) synthesized in the authors′ laboratories. Free bases, trifluoroacetyl derivatives, and trimethylsilyl derivatives were subjected to GC–MS–MS using DB-1ms, DB-5ms, and DB-17ms capillary columns, respectively. The regioisomers of chloroamphetamine analogs in all forms were well separated on the DB-5ms column. The electron ionization mass spectra of the chloroamphetamine analogs gave very little structural information for differentiation among these analogs, even after trifluoroacetyl and trimethylsilyl derivatization of the analytes. Characteristic product ions of the 2-positional isomers were observed by electron ionization-MS–MS. In contrast, chemical ionization-MS–MS of the free bases provided more structural information about chloride position on the aromatic ring when [M+H–HCl]+ was selected as a precursor ion. The results suggest that a combination of chromatographic analysis and MS–MS supports differentiation for regioisomers of chloroamphetamine analogs.
A case of primary ciliary dyskinesia treated with ICSI using testicular spermatozoa: case report and a review of the literature
Authors: Kawasaki Akiko , Okamoto Hajime , Wada Atsushi , Ainoya Yoko , Kita Naoki , Maeyama Tetsuro , Edamoto Naoko , Nishiyama Hiroyuki , Tsukamoto Sadamu , Joraku Akira , Waku Natsui , Yoshikawa Hiroyuki
Published: May 2015

Purpose

To investigate whether or not intracytoplasmic sperm injection (ICSI) using spermatozoa extracted from testis (TESE‐ICSI) is a more effective treatment than ICSI with ejaculated spermatozoa (EJ‐ICSI) for primary ciliary dyskinesia (PCD).

Methods

We reported a case of PCD in which we performed TESE‐ICSI after repeated failure of EJ‐ICSI. Together with data from previous case reports, we compared the fertilization rate and pregnancy outcome of TESE‐ICSI and EJ‐ICSI.

Results

In our case, TESE‐ICSI improved the morphology of spermatozoa and fertilization rate. However, the outcome was only a biochemical pregnancy. According to the analysis combined with previous reports, there was no difference in the fertilization rate and pregnancy outcome parameters between TESE‐ICSI and EJ‐ICSI.

Conclusions

TESE‐ICSI for PCD may improve the fertilization rate compared to EJ‐ICSI. However, it does not necessarily improve the pregnancy outcome for a patient with primary ciliary dyskinesia.