bluuebunny/crossref_metadata_2025 huggingface dataset:
Down‐regulated lysosomal processing improved pegylated lipopolyplex‐mediated gene transfection
Authors: Bai Jing , Liu Yujie , Sun Wenqiang , Chen Jian , Miller Andrew D. , Xu Yuhong
Published: April 2013

Background

Nonviral lipid‐based gene delivery vectors have been shown to possess better stability and a longer circulation time after surface poly(ethylene glycol) PEG modification. However, surface PEGylation may decrease the transfection efficiency dramatically. In the present study, we addressed the hypothesis that down‐regulating lysosomal processing with a clinical available proton pump inhibitor omeprazole might decrease the sequestration of PEGylated Lipid‐Mu‐DNA (LMD) in intracellular organelles, thereby increasing their transfection efficiencies.

Methods

LMD nanoparticles were prepared by the self‐assembling of cationic liposomes, peptide Mu and plasmid DNA. The characteristics of LMD lipopolyplexes were detected by scanning electron microscopy, photon correlation spectroscopy and DNA gel electrophoresis. They were added to cultured cells with or without omeprazole pretreatment. The detailed cellular uptake and subcellular distribution were followed by flow cytometry and confocal microscopy. Gene transfection efficiencies were evaluated in four cell lines, as well as in xenograft tumor models.

Results

Lysosome staining revealed that 0.1 mg/ml (290 μM) omeprazole raised the pH value of intracellular acidic organelles and induced alterations in the lysosomal compartments. Confocal microscopy showed that more gene materials distributed from intracellular organelles to cytoplasms with omeprazole treatment. A luciferase gene transfection assay showed that omeprazole (probably at a nontoxic concentration) increased PEGylated LMD transfection efficiency significantly in human (NCI‐H1299, HT‐1080 and A375) and mouse (4T1) cell lines, as well as in tumors of H1299 xenograft tumor models (p < 0.05).

Conclusions

Omeprazole might be used as a helper to improve gene transfection efficiencies of some PEGylated gene delivery vectors both in vitro and in vivo. Copyright © 2013 John Wiley & Sons, Ltd.
Inertia‐gravity wave in the polar mesopause region inferred from successive images of a meteor train
Authors: Suzuki Hidehiko , Nakamura Takuji , Vadas Sharon L. , Tsutsumi Masaki , Taguchi Makoto , Fujiwara Yasunori
Published: April 2013

A fireball meteor with a visual magnitude over −6 followed by a persistent train was observed by two all‐sky cameras for detecting the aurora and sodium airglow at Syowa Station (69.0°S, 39.5°E), Antarctica, on 7 June 2008. The orbit and other parameters of the fireball were estimated with an all‐sky television camera for detecting the aurora. After the passage of this fireball, a circular train in the Na airglow was observed. This train expanded to a diameter of about 50 km in 9 min. Assuming that the fireball contained and emitted Na, we found this ring to span the altitudes of z = 76 to 87 km. The ring's mean motion was most likely caused by a large‐scale, inertia‐gravity wave with a vertical wavelength of ~16 km and an amplitude of ~30 m/s in the mesopause region.
Monsoons in a changing world: A regional perspective in a global context
Authors: Kitoh Akio , Endo Hirokazu , Krishna Kumar K. , Cavalcanti Iracema F. A. , Goswami Prashant , Zhou Tianjun
Published: April 2013

We provide a new view of global and regional monsoonal rainfall, and their changes in the 21st century under RCP4.5 and RCP8.5 scenarios as projected by 29 climate models that participated in the Coupled Model Intercomparison Project phase 5. The model results show that the global monsoon area defined by the annual range in precipitation is projected to expand mainly over the central to eastern tropical Pacific, the southern Indian Ocean, and eastern Asia. The global monsoon precipitation intensity and the global monsoon total precipitation are also projected to increase. Indices of heavy precipitation are projected to increase much more than those for mean precipitation. Over the Asian monsoon domain, projected changes in extreme precipitation indices are larger than over other monsoon domains, indicating the strong sensitivity of Asian monsoon to global warming. Over the American and African monsoon regions, projected future changes in mean precipitation are rather modest, but those in precipitation extremes are large. Models project that monsoon retreat dates will delay, while onset dates will either advance or show no change, resulting in lengthening of the monsoon season. However, models’ limited ability to reproduce the present monsoon climate and the large scatter among the model projections limit the confidence in the results. The projected increase of the global monsoon precipitation can be attributed to an increase of moisture convergence due to increased surface evaporation and water vapor in the air column although offset to a certain extent by the weakening of the monsoon circulation.
Fifteen‐year aerosol optical depth climatology for Salt Lake City
Authors: Michalsky Joseph , LeBaron Brock
Published: April 2013

Aerosol optical depth (AOD) and its wavelength dependence have been measured for the past 15 years in the Salt Lake City metropolitan area using a multifilter rotating shadowband radiometer. The instrument has not experienced a major hardware failure. It has been continuously field calibrated for extraterrestrial responses in its five aerosol channels. The instrument's cosine response was measured in 1996 and again in 2012. In our analysis of this 15 year data set, linear interpolation of these two cosine responses was used to approximate the angular response between the two characterizations. The Salt Lake City aerosol burden increased through the mid‐2000s, but has dropped to its lowest level of the record since that time despite a population increase of approximately 25%. Annually, the aerosol burden is highest in midspring and midsummer with relatively coarse aerosols during the spring peak and fine aerosols during the summer peak. There is no indication of a diurnal cycle in AOD. There is a significant, but low, correlation between PM2.5 and 500 nm AOD, and a slightly lower correlation between PM10 and 500 nm AOD. The correlations between the surface‐based measurements and total column AOD explain only 13% and 9% of the variance, respectively. Measurements are continuing to track future trends.
Volcanic sulfate deposition to Greenland and Antarctica: A modeling sensitivity study
Authors: Toohey Matthew , Krüger Kirstin , Timmreck Claudia
Published: April 2013

Reconstructions of the atmospheric sulfate aerosol burdens resulting from past volcanic eruptions are based on ice core‐derived estimates of volcanic sulfate deposition and the assumption that the two quantities are directly proportional. We test this assumption within simulations of tropical volcanic stratospheric sulfur injections with the MAECHAM5‐HAM aerosol‐climate model. An ensemble of 70 simulations is analyzed, with SO2 injections ranging from 8.5 to 700 Tg, with eruptions in January and July. Modeled sulfate deposition flux to Antarctica shows excellent spatial correlation with ice core‐derived estimates for Pinatubo and Tambora, although the comparison suggests the modeled flux to the ice sheets is 4–5 times too large. We find that Greenland and Antarctic deposition efficiencies (the ratio of sulfate flux to each ice sheet to the maximum hemispheric stratospheric sulfate aerosol burden) vary as a function of the magnitude and season of stratospheric sulfur injection. Changes in simulated sulfate deposition for large SO2 injections are connected to increases in aerosol particle size, which impact aerosol sedimentation velocity and radiative properties, the latter leading to strong dynamical changes including strengthening of the winter polar vortices, which inhibits the transport of stratospheric aerosols to high latitudes. The resulting relationship between Antarctic and Greenland volcanic sulfate deposition is nonlinear for very large eruptions, with significantly less sulfate deposition to Antarctica than to Greenland. These model results suggest that variability of deposition efficiency may be an important consideration in the interpretation of ice core sulfate signals for eruptions of Tambora‐magnitude and larger.
Changes in tau phosphorylation in hibernating rodents
Authors: León‐Espinosa Gonzalo , García Esther , García‐Escudero Vega , Hernández Félix , DeFelipe Javier , Avila Jesús
Published: April 2013

Tau is a cytoskeletal protein present mainly in the neurons of vertebrates. By comparing the sequence of tau molecule among different vertebrates, it was found that the variability of the N‐terminal sequence in tau protein is higher than that of the C‐terminal region. The N‐terminal region is involved mainly in the binding of tau to cellular membranes, whereas the C‐terminal region of the tau molecule contains the microtubule‐binding sites. We have compared the sequence of Syrian hamster tau with the sequences of other hibernating and nonhibernating rodents and investigated how differences in the N‐terminal region of tau could affect the phosphorylation level and tau binding to cell membranes. We also describe a change, in tau phosphorylation, on a casein kinase 1 (ck1)‐dependent site that is found only in hibernating rodents. This ck1 site seems to play an important role in the regulation of tau binding to membranes. © 2013 Wiley Periodicals, Inc.
Workplace racial/ethnic similarity, job satisfaction, and lumbar back health among warehouse workers: Asymmetric reactions across racial/ethnic groups
Authors: Hoppe Annekatrin , Fujishiro Kaori , Heaney Catherine A.
Published: April 2013

Racial and ethnic minority employees constitute a significant proportion of the U.S. workforce. The literature on demographic similarity in the workplace suggests that the proportion of co‐workers who share the same racial/ethnic background (racial/ethnic similarity) can influence job attitudes and employee well‐being and that the reactions to racial/ethnic similarity may differ between the racially dominant and subordinate groups. This study applies status construction theory to examine the extent to which racial/ethnic similarity is associated with job satisfaction and lumbar back health among warehouse employees. We surveyed 361 warehouse workers (204 whites, 94 African‐Americans, and 63 Latino workers) in 68 jobs in nine distribution centers in the United States. Multilevel analyses indicate that white and racial/ethnic minority groups react differently to racial/ethnic similarity. For job satisfaction, white employees experience higher job satisfaction when they are highly racially/ethnically similar to their colleagues, whereas Latino employees experience higher job satisfaction when they are racially/ethnically dissimilar to others. As for lumbar back health, among Latino and African‐American employees, higher racial/ethnic similarity is associated with better lumbar back health whereas for white employees, the association is the opposite. Across all groups, moderate levels of racial/ethnic similarity were associated with the best lumbar back health. Copyright © 2013 John Wiley & Sons, Ltd.
Mechanics of post‐cam engagement during simulated dynamic activity
Authors: Fitzpatrick Clare K. , Clary Chadd W. , Cyr Adam J. , Maletsky Lorin P. , Rullkoetter Paul J.
Published: April 2013

Posterior‐stabilized (PS) total knee arthroplasty (TKA) components employ a tibial post and femoral cam mechanism to guide anteroposterior knee motion in lieu of the posterior cruciate ligament. Some PS TKA patients report a clicking sensation when the post and cam engage, while severe wear and fracture of the post; we hypothesize that these complications are associated with excessive impact velocity at engagement. We evaluated the effect of implant design on engagement dynamics of the post‐cam mechanism and resulting polyethylene stresses during dynamic activity. In vitro simulation of a knee bend activity was performed for four cadaveric specimens implanted with PS TKA components. Post‐cam engagement velocity and flexion angle at initial contact were determined. The experimental data were used to validate computational predictions of PS mechanics using the same loading conditions. A lower limb model was subsequently utilized to compare engagement mechanics of eight TKA designs, relating differences between implants to geometric design features. Flexion angle and post‐cam velocity at engagement demonstrated considerable ranges among designs (23°–89°, and 0.05–0.22 mm/°, respectively). Post‐cam velocity was correlated (r = 0.89) with tibiofemoral condylar design features. Condylar geometry, in addition to post‐cam geometry, played a significant role in minimizing engagement velocity and forces and stresses in the post. This analysis guides selection and design of PS implants that facilitate smooth post‐cam engagement and reduce edge loading of the post. © 2013 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 31:1438–1446, 2013
Grieving, Learning, and Growing
Authors: Schuttler Richard , Lentz Cheryl
Published: April 2013

The process of organizational and personal improvement can often be a daunting challenge, particularly for organizational and executive leaders. To address this process, the authors offer a cognitive learning strategy for any leader to consider as part of his or her personal development process based on the nexus of Elisabeth Kübler‐Ross's stages of grief, Benjamin Bloom's cognitive taxonomy, and Richard Schuttler's executive mentoring model. In a time when formal and informal leaders are needed to set a great example, the industry of mentoring (and coaching) appears to have many people trying to help others, yet perhaps not all of them have the foundational underpinnings of knowledge needed to fully understand the emotional reactions or steps to learning.
Survival–Recovery Effect: Military Wives With Soldier–Husbands Deployed to the Operation Iraqi Freedom Conflict
Authors: Chambers Joan E.
Published: April 2013

Typical stressful emotions for wartime military wives have not changed since the Vietnam War. Given the catastrophic nature of the Operation Iraqi Freedom (OIF) war of the 21st century, growing concerns have emerged from the public regarding this population's psychological and physical health. A qualitative phenomenological analysis explored an in‐depth OIF deployment separation on eight military wives' psychological, physical, and spiritual well‐being with soldier‐husbands' indefinite deployment. From the dominant thematic findings emerged an overall experience for this population, named a “survival‐recovery effect.” Results strikingly mirrored previous empirical research that confirmed the military wives have been unprepared to manage war‐induced deployment separations. Implications suggested a critical need to develop intervention support services and programs aimed at addressing the unique wartime stressors for this population. Insights from these women have the potential to guide future military wives through a wartime crisis. Findings have wide benefits for the military wife population vital to soldier retention, segments of the military and civilian scientific communities, and the field of psychology. Future recommendations and limitations are outlined.
Scholarship in Administration: Connecting With the University Culture
Authors: Coe Aaron D. , Heitner Keri L.
Published: April 2013

This phenomenological hermeneutic study explored the meaning found in the lived experience of producing scholarship for five higher education administrators from within the major areas of administration in higher education—academic affairs, business affairs, and student affairs—from a single research university. In the historical and recent scholarship about the three fields of higher education, one issue that has not been addressed is the meaning found in producing scholarship as an administrator. Thus, the challenges and rewards of producing scholarship as a practicing administrator, creating the first step toward a possible new era in the practice of scholarship on college campuses, were explored. Individual semistructured interviews were the primary source of data, and the authors used a three‐step data analysis process to develop both an understanding of what producing scholarship means for each participant and an interpretation of the meaning of producing scholarship as a higher education administrator. Across all the lived experiences of the various scholarly endeavors, each administrator was more connected to education and contributed more to the educational environment by participating in scholarly activities. The administrators were found to be more connected to the people within the university, to their own field of practice, and to the university itself.
Individual and combined effects of genistein and hesperidin supplementation on meat quality in meat‐type broiler chickens
Authors: Kamboh Asghar A , Zhu Wei‐Yun
Published: April 2013

BACKGROUND

There is growing interest in improving the production and meat quality of farm animals through dietary supplementation with phytochemical (e.g. flavonoids)‐rich plants and/or their extracts. This study was conducted to analyse the supplemental effects of two purified flavonoids (genistein and hesperidin) individually and in combination on the oxidative status, sensory score and quality of breast meat in meat‐type broiler chickens.

RESULTS

A significant increase (P < 0.05) in meat colour (L* score) and pH was observed for the group supplemented with 20 mg kg−1 genistein and hesperidin. Water‐holding capacity was also improved significantly (P < 0.01) for all genistein‐ and hesperidin‐treated groups, while the sensory quality of breast meat remained unaffected. Lipid oxidation of breast meat was reduced significantly (P < 0.01) at 0 and 15 days of refrigeration in a dose‐dependent manner for all supplemented groups. Meanwhile, some treated groups showed improved (P < 0.05) body weight, feed/gain ratio and hot carcass weight.

CONCLUSION

Genistein and hesperidin supplementation to broilers improved meat quality in a dose‐dependent fashion, with pronounced effects of combined treatment. The results indicated that purified flavonoids such as genistein and hesperidin could potentially be used as feed additives in broiler production to promote meat quality. © 2013 Society of Chemical Industry
Functional properties of wheat starch with different particle size distribution
Authors: Zeng Jie , Gao Haiyan , Li GuangLei
Published: April 2013

BACKGROUND

Functional properties of wheat starches with different particle size distribution were investigated.

RESULTS

A‐granules displayed a disc shape and B‐granules displayed a spherical shape. A‐granules had the highest conclusion temperature (Tc, 80.28 °C) and gelatinisation enthalpy (3.268 J g−1) and B‐granules had the highest peak temperature (Tp, 66.00 °C) and the lowest gelatinisation enthalpy (2.237 J g−1). The gelatinisation onset temperature (To), the peak temperature (Tp), Tc and retrogradation of mixed starches increased with the increase of the ratio of B‐granules, while the enthalpy, all the viscosity parameters and syneresis of mixed starches decreased with the increase of the ratio of B granules. B‐granules had a higher pasting temperature. The sample of B/A = 0.5/10 had the highest peak, breakdown and final viscosity. The percentage of water separated from B‐granule gels was minimal, indicated that B‐type gels were more stable than other samples. The ΔH2 of A‐granules was obviously higher than that of B‐granules. However, during storage, the ΔH2 of the starch paste was dramatically increased and the ΔH2 of B‐granules was obviously higher than that of A‐granules.

CONCLUSION

B‐granules were easier to age than A‐granules and most of the properties of wheat starches varied significantly with the ratio of B‐granules. The relationship between structure and functionality of wheat starch received further verification. © 2013 Society of Chemical Industry
Posttraumatic Stress Disorder and Fear of Emotions: The Role of Attentional Control
Authors: Sippel Lauren M. , Marshall Amy D.
Published: April 2013

Individuals with posttraumatic stress disorder (PTSD) experience elevated concerns about their capacity to control, and the consequences of, strong emotions that occur in response to trauma reminders. Anxiety is theorized to compromise attentional control (Eysenck, Derakshan, Santos, & Calvo, 2007). In turn, diminished attentional control may increase vulnerability to threat cues and emotional reactivity (Ehlers & Clark, 2001). Consequently, attentional control may play a role in the fear of emotions frequently experienced by individuals with PTSD. Study participants included 64 men and 64 women with a mean age of 37 years, 86% of whom were White, non‐Hispanic. Participants experienced an average of 7.68 types of traumatic events, most commonly including motor vehicle accidents and intimate partner violence. PTSD symptoms positively correlated with fear of emotions (r = .53) and negatively correlated with attentional control (r = −.38). Attentional control was negatively correlated with fear emotions (r = −.77) and partially mediated the link between PTSD and fear of emotions (R2 = .22). Given the findings regarding top‐down attentional control, these results have implications for cognitive and emotional processing theories of PTSD and emphasize the importance of clinical consideration of fear of emotions and attentional control in the treatment of PTSD.
A Dual Enzyme Microgel with High Antioxidant Ability Based on Engineered Seleno‐Ferritin and Artificial Superoxide Dismutase
Authors: Gao Yuzhou , Hou Chunxi , Zhou Lipeng , Zhang Dongmei , Zhang Chunqiu , Miao Lu , Wang Liang , Dong Zeyuan , Luo Quan , Liu Junqiu
Published: April 2013

An antioxidant microgel with both glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities is reported. Using computational design and genetic engineering methods, the main catalytic components of GPx are fabricated onto the surface of ferritin. The resulting seleno‐ferritin (Se‐Fn) monomers can self‐assemble into nanocomposites that exhibit remarkable GPx activity due to the well organized multi‐GPx catalytic centers. Subsequently, a porphyrin derivative is synthesized as an SOD mimic, and is employed to construct a synergistic dual enzyme system by crosslinking Se‐Fn nanocomposites into a microgel. Significantly, this dual enzyme microgel is demonstrated to display better antioxidant ability than single GPx or SOD mimics in protecting cells from oxidative damage.

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A High‐Efficiency Strategy for Synthesizing Cyclic Polymers of Methacryates in One Pot
Authors: Zhu Xing , Zhou Nianchen , Zhu Jian , Zhang Zhengbiao , Zhang Wei , Cheng Zhenping , Tu Yingfeng , Zhu Xiulin
Published: April 2013

An unprecedented strategy for the high‐efficiency preparation of the cyclic polymers is developed. In this strategy, the atom transfer radical polymerization, the substitution of chain‐end halide by azide group and Cu‐catalyzed alkyne–azide cyclization, i.e., the frequently used three separated steps for the preparation of cyclic polymers, are integrated into a one‐pot reaction by the introduction of a “regulator”. The kernel of this novel strategy is the utilization of the different rates between the competitive ATRP propagation and SN2 substitution of a tertiary‐carbon halogen and secondary‐carbon halogen. 0.55 g (yield = 59%) cyclic poly(methyl methacrylate) is obtained from 3.0 mL reaction solution. This work proposed a high‐efficiency and bright promising strategy for the preparation of cyclic polymer, which would evoke more research interests on cyclic polymer.

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Improved respiratory efficiency of 3D late gadolinium enhancement imaging using the continuously adaptive windowing strategy (CLAWS)
Authors: Keegan Jennifer , Jhooti Permi , Babu‐Narayan Sonya V , Drivas Peter , Ernst Sabine , Firmin David N.
Published: April 2013

Purpose

Acquisition durations of navigator‐gated high‐resolution three‐dimensional late gadolinium enhancement studies may typically be up to 10 min, depending on the respiratory efficiency and heart rate. Implementation of the continuously adaptive windowing strategy (CLAWS) could increase respiratory efficiency, but the resulting non‐smooth k‐space acquisition order during gadolinium wash‐out could result in increased artifact.

Methods

Navigator‐gated three‐dimensional late gadolinium enhancement acquisitions were performed in 18 patients using tracking end‐expiratory accept/reject (EE‐ARA) and CLAWS algorithms in random order.

Results

Retrospective analysis of the stored navigator data shows that CLAWS scan times are very close to (within 1%) or equal to the fastest achievable scan times while EE‐ARA significantly extends the acquisition duration (P < 0.0001). EE‐ARA acquisitions are 26% longer than CLAWS acquisitions (378 ± 104 s compared to 301 ± 85 s, P = 0.002). Image quality scores for CLAWS and EE‐ARA acquisitions are not significantly different (4.1 ± 0.6 compared to 4.3 ± 0.6, P = ns). Numerical phantom simulations show that the non‐uniform k‐space ordering introduced by CLAWS results in slight, but not statistically significant, reductions in both blood signal‐to‐noise ratio (10%) and blood‐myocardium contrast‐to‐noise ratio (12%).

Conclusions

CLAWS results in markedly reduced acquisition durations compared to EE‐ARA without significant detriment to the image quality. Magn Reson Med 71:1064–1074, 2014. © 2013 Wiley Periodicals, Inc.
Nuclear spin singlet states as a contrast mechanism for NMR spectroscopy
Authors: DeVience Stephen J. , Walsworth Ronald L. , Rosen Matthew S.
Published: April 2013

Nuclear magnetic resonance (NMR) spectra of complex chemical mixtures often contain unresolved or hidden spectral components, especially when strong background signals overlap weaker peaks. In this article we demonstrate a quantum filter utilizing nuclear spin singlet states, which allows undesired NMR spectral background to be removed and target spectral peaks to be uncovered. The quantum filter is implemented by creating a nuclear spin singlet state with spin quantum numbers j = 0, mz = 0 in a target molecule, applying a continuous RF field to both preserve the singlet state and saturate the magnetization of undesired molecules and then mapping the target molecule singlet state back into an NMR observable state so that its spectrum can be read out unambiguously. The preparation of the target singlet state can be carefully controlled with pulse sequence parameters, so that spectral contrast can be achieved between molecules with very similar structures. We name this NMR contrast mechanism ‘Suppression of Undesired Chemicals using Contrast‐Enhancing Singlet States’ (SUCCESS) and we demonstrate it in vitro for three target molecules relevant to neuroscience: aspartate, threonine and glutamine. Copyright © 2013 John Wiley & Sons, Ltd.
Morphological Characteristics of Healthy and Osteoarthritic Joint Surfaces in Archaeological Skeletons
Authors: Plomp K. A. , Roberts C. A. , Strand Viðarsdόttir U.
Published: April 2013

Osteoarthritis is a major health concern in living populations, as well as being one of the most common pathological lesions identified in the archaeological record. The aetiology of the disease remains unclear, with a multi‐factorial influence of physical strain, age, genetics, and obesity. Previous studies have identified a relationship between the presence of knee osteoarthritis on the distal femoral joint and the morphology of the intercondylar notch, patellar groove, and medial condyle. The current study expands this research to investigate the relationship between distal femoral, distal humeral, and proximal ulnar joint morphology and osteoarthritis with 3D shape analysis techniques. These methods provide a more detailed analysis of joint morphology in order to determine any relationship between 3D shape and osteoarthritis. The results indicate a complex relationship between joint shape and knee osteoarthritis, with eburnated right femora showing a statistically significant association. The shapes associated with eburnated or affected femoral joints can be explained by osteophyte development, and therefore likely represent systematic shape changes and not a particular joint shape predisposing individuals to the condition. There was no identifiable relationship found in the proximal ulna or distal humerus, indicating that joint shape is unlikely to influence the development of the condition in the elbow joint and that any shape changes produced by osteoarthritis are not systematic or quantifiable. The joints analysed in this study were highly influenced by asymmetry, sexual dimorphism, and allometry, resulting in a small sample size of affected joints in many datasets. Further analyses of large skeletal samples are needed to more thoroughly investigate the possible relationship of distal femoral joint shape and osteoarthritis. Copyright © 2013 John Wiley & Sons, Ltd.
Nitroxide mediated synthesis of low dispersity random copolymers for low‐loss optical waveguides
Authors: Wang Zi Jun , Maric Milan
Published: April 2013

Candidate materials for low‐loss optical waveguides based on poly(glycidyl methacrylate‐ran‐pentafluostyrene) [P(GMA‐ran‐PFS)] copolymers were synthesized by nitroxide mediated polymerization (NMP) initiated with BlocBuilder® [N‐(2‐methylpropyl)‐N‐(1‐diethlphosphono‐2,2‐dimethylpropyl)‐O‐(2‐carboxylprop‐2‐yl) hydroxylamine] bearing a succinimidyl ester group (NHS‐BlocBuilder) at 90 °C in 1,4 dioxane. The copolymerizations yielded copolymers with low dispersity Mw/Mn between 1.2 and 1.4. The core structure of single‐mode channel waveguides was fabricated by direct UV lithographic patterning. The copolymers with low Mw/Mn resulted in line width roughness (LWR) of about 0.16 μm, whereas LWR of copolymers with Mw/Mn=3.5 but similar compositions was about 0.5 μm. The improvement in microstructural control allotted by NMP permitted finer pattern replication for copolymers desired for optical waveguides, as suggested for photoresist polymers. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2970–2978
Synthesis of poly(ethylene glycol)‐based hydrogels and their swelling/shrinking response to molecular recognition
Authors: Tominaga Yuichi , Kubo Takuya , Sueyoshi Kenji , Hosoya Ken , Otsuka Koji
Published: April 2013

To synthesize the novel molecular‐ and pH‐stimulus‐responsive hydrogel, we prepared poly(ethylene glycol)‐based hydrogel containing ionic groups. We evaluated the fundamental swelling/shrinking properties of the hydrogels synthesized by various conditions. Decreasing the molecular weight of a crosslinker provided the increasing of the equilibrium swelling ratio. Also, the equilibrium swelling ratio was changed by the introduction of functional ionic monomers and its compositions. Furthermore, the swelling/shrinking behaviors of the hydrogels were affected by the environmental condition of aqueous solution, in fact the hydrogels were considerably shrunk (to one‐fifth volume) using a di‐ionic solute in the aqueous solution through the ionic interactions between the hydrogel and the solutes. Additionally, the specific shrinking to diamine compounds was also observed in response to pH change. These results clearly show the swelling/shrinking responsibility of the hydrogels toward the molecular recognitions and its pH conditions. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3153–3158
Seleno‐containing poly(vinyl acetate) prepared by diselenocarbonates‐mediated controlled free radical polymerizations
Authors: Ma Fei , Zhu Jian , Zhang Zhengbiao , Pan Xiangqiang , Zhou Nianchen , Zhu Xiulin
Published: April 2013

The living free radical polymerizations of vinyl acetate (VAc) were successfully achieved in the presence of a novel organic selenium compound (diselenocarbonates), with 2,2′‐azobisisobutyronitrile (AIBN) as the initiator. The living characteristics of the VAc polymerization were confirmed by the linear first‐order kinetic plots and linear increase of molecular weights (Mn) of the polymers with monomer conversions, while keeping the relatively low molecular weight distributions. In addition, the end of the polymers contains selenium element which may be useful in biotechnological and biomedical applications. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3159–3165
Dendron–polymer conjugates via the diels–alder “click” reaction of novel anthracene‐based dendrons
Authors: Gok Ozgul , Yigit Sezin , Merve Kose Meliha , Sanyal Rana , Sanyal Amitav
Published: April 2013

Diblock and triblock dendron–polymer conjugates containing biodegradable polyester dendron blocks and polyethylene glycol (PEG) polymer were synthesized using the Diels–Alder “click” cycloaddition reaction. PEG polymers with furan‐protected maleimide functionality were synthesized and reacted with biodegradable polyester dendrons containing an anthracene moiety at their focal point. First through third generations of biodegradable polyester dendrons containing an anthracene unit at their focal point were synthesized using a divergent strategy. Efficient conjugation of the dendrons to polymers was demonstrated using 1HNMR and size exclusion chromatography. This modular approach provides an easy access to the design of multivalent PEG conjugates. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3191–3201
A review of the manufacture, mechanical properties and potential applications of auxetic foams
Authors: Critchley Richard , Corni Ilaria , Wharton Julian A. , Walsh Frank C. , Wood Robert J. K. , Stokes Keith R.
Published: April 2013

Auxetics are a modern class of material fabricated by altering the material microstructure. Unlike conventional materials, auxetics exhibit a negative Poisson's ratio when subjected to tensile loading. These materials have gained popularity within the research community because of their enhanced properties, such as density, stiffness, fracture toughness and dampening. This paper provides a critical oversight of the auxetic field with particular emphasis to the auxetic foams, due to their low price, easy availability and desirable mechanical properties. Key areas discussed include the fabrication method, the effects played by different parameters (temperature, heating time, cell shape and size and volumetric compression ratio), microstructural models, mechanical properties and potential applications.
Effect of assay measurement error on parameter estimation in concentration–QTc interval modeling
Authors: Bonate Peter L.
Published: April 2013

Linear mixed‐effects models (LMEMs) of concentration–double‐delta QTc intervals (QTc intervals corrected for placebo and baseline effects) assume that the concentration measurement error is negligible, which is an incorrect assumption. Previous studies have shown in linear models that independent variable error can attenuate the slope estimate with a corresponding increase in the intercept. Monte Carlo simulation was used to examine the impact of assay measurement error (AME) on the parameter estimates of an LMEM and nonlinear MEM (NMEM) concentration–ddQTc interval model from a ‘typical’ thorough QT study. For the LMEM, the type I error rate was unaffected by assay measurement error. Significant slope attenuation ( > 10%) occurred when the AME exceeded > 40% independent of the sample size. Increasing AME also decreased the between‐subject variance of the slope, increased the residual variance, and had no effect on the between‐subject variance of the intercept. For a typical analytical assay having an assay measurement error of less than 15%, the relative bias in the estimates of the model parameters and variance components was less than 15% in all cases. The NMEM appeared to be more robust to AME error as most parameters were unaffected by measurement error. Monte Carlo simulation was then used to determine whether the simulation–extrapolation method of parameter bias correction could be applied to cases of large AME in LMEMs. For analytical assays with large AME ( > 30%), the simulation–extrapolation method could correct biased model parameter estimates to near‐unbiased levels. Copyright © 2013 John Wiley & Sons, Ltd.
Solving the Multidisciplinary Robust Parameter Design Problem for Mixed Type Quality Characteristics under Asymmetric Conditions
Authors: Boylan Gregory L. , Cho Byung Rae
Published: April 2013

Quality practitioners often identify robust parameter design (RPD) as one of the most important and effective methods for process and quality improvement. Within this framework, identifying the optimal factor settings that achieve desired process targets with minimum variance is critical and can translate to significant reductions in product waste and processing costs. In solving this problem, most traditional RPD models consider only a single quality characteristic of interest. However, products are often judged by multiple quality characteristics, which often have conflicting objectives. Conventional RPD models that address the multi‐response problem typically only examine like‐type cases, and those that consider mixed types of quality characteristics often overlook any asymmetry that is likely to exist in certain types.

In contrast, this article proposes a multidisciplinary RPD methodology that provides an enhanced approach for modeling multiple, mixed type quality characteristics; uses the skew normal distribution to allow for a fuller and more accurate representation of asymmetric system properties and to facilitate simultaneous modeling of both symmetric and asymmetric conditions; and implements a priority‐based optimization scheme that affords engineers' and decision makers' flexibility in establishing and modifying optimization priorities. A numerical example is used to demonstrate the proposed methodology, and the results are compared traditional approaches to illustrate potential improvements. Copyright © 2013 John Wiley & Sons, Ltd.
Secure and efficient integration of big data for multi‐cells based on micro images
Authors: Yin Xin , Sun Yaqiu
Published: April 2013

Information of multi‐cells is big data because of the enormous quantities of various cells as well as their parameters and status. To securely and efficiently integrate all the cells' information and trace multi‐cells are challenging due to varying number of the multi‐cells, as well as the complicacy of the multi‐cells' movement. In this paper, an automatic big data integration algorithm based on the optical transfer function is proposed. The experimental results show that the algorithm can securely and efficiently integrate all the cell information and simultaneously track a large quantity of cells. Copyright © 2013 John Wiley & Sons, Ltd.
The Linux kernel: a case study of build system variability
Authors: Nadi Sarah , Holt Ric
Published: April 2013

Although build systems control what code gets compiled into the final built product, they are often overlooked when studying software variability. The Linux kernel is one of the biggest open source software systems supporting variability and contains over 10,000 configurable features described in its Kconfig files. To understand the role of the build system in variability implementation, we use Linux as a case study. We study its build system, Kbuild, and extract the variability constraints in its Makefiles. We first provide a quantitative analysis of the variability in Kbuild. We then study how the variability constraints in the build system affect variability anomalies detected in Linux. We concentrate on dead and undead artifacts, and by extending previous work, we show that considering build system variability constraints allows more anomalies to be detected. We provide examples of such anomalies on both the code block and source file level. Our work shows that Kbuild contains a large percentage of the variability information in Linux, so it should not be ignored during variability analysis. Nonetheless, the anomalies we find suggest that variability on the file level in Kbuild is consistent with Kconfig, whereas the constraints on the code level are harder to keep consistent with both Kbuild and Kconfig. Copyright © 2013 John Wiley & Sons, Ltd.
Multipotent Stromal Cells Alleviate Inflammation, Neuropathology, and Symptoms Associated with Globoid Cell Leukodystrophy in the Twitcher Mouse
Authors: Scruggs Brittni A. , Zhang Xiujuan , Bowles Annie C. , Gold Peter A. , Semon Julie A. , Fisher-Perkins Jeanne M. , Zhang Shijia , Bonvillain Ryan W. , Myers Leann , Li Su Chen , Kalueff Allan V. , Bunnell Bruce A.
Published: April 2013

Globoid cell leukodystrophy (GLD) is a common neurodegenerative lysosomal storage disorder caused by a deficiency in galactocerebrosidase (GALC), an enzyme that cleaves galactocerebroside during myelination. Bone marrow transplantation has shown promise when administered to late-onset GLD patients. However, the side effects (e.g., graft vs. host disease), harsh conditioning regimens (e.g., myelosuppression), and variable therapeutic effects make this an unsuitable option for infantile GLD patients. We previously reported modest improvements in the twitcher mouse model of GLD after intracerebroventricular (ICV) injections of a low-dose of multipotent stromal cells (MSCs). Goals of this study were to improve bone marrow-derived MSC (BMSC) therapy for GLD by increasing the cell dosage and comparing cell type (e.g., transduced vs. native), treatment timing (e.g., single vs. weekly), and administration route (e.g., ICV vs. intraperitoneal [IP]). Neonatal twitcher mice received (a) 2 × 105 BMSCs by ICV injection, (b) 1 × 106 BMSCs by IP injection, (c) weekly IP injections of 1 × 106 BMSCs, or (d) 1 × 106 lentiviral-transduced BMSCs overexpressing GALC (GALC-BMSC) by IP injection. All treated mice lived longer than untreated mice. However, the mice receiving peripheral MSC therapy had improved motor function (e.g., hind limb strength and rearing ability), twitching symptoms, and weight compared to both the untreated and ICV-treated mice. Inflammatory cell, globoid cell, and apoptotic cell levels in the sciatic nerves were significantly decreased as a result of the GALC-BMSC or weekly IP injections. The results of this study indicate a promising future for peripheral MSC therapy as a noninvasive, adjunct therapy for patients affected with GLD.
Modeling and simulation in engineering
Authors: Sahinoglu Mehmet
Published: April 2013

This review article will explore the innovative and popular theme of engineering modeling and simulation, predominantly in the manufacturing industry and cybersecurity world, citing severe challenges, advantages and time‐ and budget saving solutions and its future. The power of simulation is not an exaggeration but an understatement. The favorable outcomes since the advent of digital computers and software revolution could not have been achieved, especially without the multiple benefits of statistical simulation, which underlies the widespread use of modeling and simulation in engineering and sciences, stretching from A (Astronomy) to Z (Zoology). This refers not only to research findings in verifying a certain piece of theory, such as that of the recently discovered Higgs Boson, but in testing new products to innovate new discoveries so as to make our universe a more peaceful place by modeling and simulating the future projects and taking precautions before disasters occur. The review explores a cross section of engineering modeling and simulation practices illustrating a window of numerical examples. WIREs Comput Stat 2013, 5:239–266. doi: 10.1002/wics.1254

This article is categorized under:

Statistical and Graphical Methods of Data Analysis > Markov Chain Monte Carlo (MCMC)

Statistical Learning and Exploratory Methods of the Data Sciences > Modeling Methods

Algorithms and Computational Methods > Random Number Generation

Statistical Models > Simulation Models
Prediction of spatially variable unsaturated hydraulic conductivity using scaled particle‐size distribution functions
Authors: Nasta Paolo , Romano Nunzio , Assouline Shmuel , Vrugt Jasper A. , Hopmans Jan W.
Published: April 2013

Simultaneous scaling of soil water retention and hydraulic conductivity functions provides an effective means to characterize the heterogeneity and spatial variability of soil hydraulic properties in a given study area. The statistical significance of this approach largely depends on the number of soil samples collected. Unfortunately, direct measurement of the soil hydraulic functions is tedious, expensive and time consuming. Here we present a simple and cost‐effective hybrid scaling approach that combines the use of ancillary information (e.g., particle‐size distribution and soil bulk density) with direct measurements of saturated soil water content and saturated hydraulic conductivity. Our results demonstrate that the presented approach requires far fewer laboratory measurements than conventional scaling methods to adequately capture the spatial variability of soil hydraulic properties.
Drainage‐system development in consecutive melt seasons at a polythermal, Arctic glacier, evaluated by flow‐recession analysis and linear‐reservoir simulation
Authors: Hodgkins Richard , Cooper Richard , Tranter Martyn , Wadham Jemma
Published: April 2013

The drainage systems of polythermal glaciers play an important role in high‐latitude hydrology, and are determinants of ice flow rate. Flow‐recession analysis and linear‐reservoir simulation of runoff time series are here used to evaluate seasonal and inter‐annual variability in the drainage system of the polythermal Finsterwalderbreen, Svalbard, in 1999 and 2000. Linear‐flow recessions are pervasive, with mean coefficients of a fast reservoir varying from 16 (1999) to 41 h (2000), and mean coefficients of an intermittent, slow reservoir varying from 54 (1999) to 114 h (2000). Drainage‐system efficiency is greater overall in the first of the two seasons, the simplest explanation of which is more rapid depletion of the snow cover. Reservoir coefficients generally decline during each season (at 0.22 h d−1 in 1999 and 0.52 h d−1 in 2000), denoting an increase in drainage efficiency. However, coefficients do not exhibit a consistent relationship with discharge. Finsterwalderbreen therefore appears to behave as an intermediate case between temperate glaciers and other polythermal glaciers with smaller proportions of temperate ice. Linear‐reservoir runoff simulations exhibit limited sensitivity to a relatively wide range of reservoir coefficients, although the use of fixed coefficients in a spatially lumped model can generate significant subseasonal error. At Finsterwalderbreen, an ice‐marginal channel with the characteristics of a fast reservoir, and a subglacial upwelling with the characteristics of a slow reservoir, both route meltwater to the terminus. This suggests that drainage‐system components of significantly contrasting efficiencies can coexist spatially and temporally at polythermal glaciers.
A coupled agronomic‐economic model to consider allocation of brackish irrigation water
Authors: Ben‐Gal Alon , Weikard Hans‐Peter , Shah Syed Hamid Hussain , van der Zee Sjoerd E. A. T. M.
Published: April 2013

Key Points

A sequential water use model with scarcity, inefficiency and saline return

Marginal value of water is computed according to scarcity, salinity and loss

Water management benefits increase with salinity level and evaporative losses
Temporal and spatial scaling of hydraulic response to recharge in fractured aquifers: Insights from a frequency domain analysis
Authors: Jiménez‐Martínez Joaquín , Longuevergne Laurent , Le Borgne Tanguy , Davy Philippe , Russian Anna , Bour Olivier
Published: April 2013

Key Points

Frequency domain analysis in fractured aquifers

Temporal and spatial scaling in fractures aquifers

Hydraulic parameters at large scale and aquifer recharge mechanisms