bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pedometer-Assessed Physical Activity in Children and Young Adults with CKD
Authors: Akber Aalia , Portale Anthony A. , Johansen Kirsten L. 
Published: March 2012

Summary

Background and objectives
Data on physical activity are limited in children with CKD. The objectives of this study were to measure the level and correlates of physical activity in children and young adults with CKD and to determine the association of physical activity with physical performance and physical functioning.

Design, setting, participants, & measurements
Physical activity was measured for 7 days using pedometers; physical performance was measured by the 6-minute walk distance (6MWD) and physical functioning with the PedsQL 4.0.

Results
Study participants were 44 patients 7–20 years of age who had CKD stage 1–4 (n=12), had ESRD and were undergoing dialysis (n=7), or had undergone kidney transplantation (n=25). Participants were very sedentary; they walked 6218 (interquartile range, 3637, 9829) steps per day, considerably less than recommended. Physical activity did not differ among participants in the CKD stage 1–4, ESRD, and transplant groups. Females were less active than males (P<0.01), and physical activity was 44% lower among young adults (18–20 years) than younger participants (P<0.05). Physical activity was associated positively with maternal education and hemoglobin concentration and inversely with body mass index. Respective 6MWD in males and females was 2 and approximately 4 SDs below expected. Low levels of physical activity were associated with poor physical performance and physical functioning, after adjustment for age, sex, and body mass index.

Conclusions
In most participants with CKD, physical activity was considerably below recommended levels. Future studies are needed to determine whether increasing physical activity can improve physical performance and physical functioning.
Effect of Vitamin D Repletion on Urinary Calcium Excretion among Kidney Stone Formers
Authors: Leaf David E. , Korets Ruslan , Taylor Eric N. , Tang Jie , Asplin John R. , Goldfarb David S. , Gupta Mantu , Curhan Gary C. 
Published: March 2012

Summary

Background and objectives
Despite the important role of vitamin D in maintaining bone health, many clinicians are reluctant to treat vitamin D deficiency in kidney stone formers because of the theoretical risk of increasing urinary calcium excretion. This study examined the effect of vitamin D repletion on urinary calcium excretion among stone formers.

Design, setting, participants, & measurements
Participants (n=29) were recruited from urology clinics affiliated with New York Presbyterian Hospital. Enrollment criteria included a history of nephrolithiasis, urinary calcium excretion between 150 and 400 mg/d, and a serum 25-hydroxyvitamin D level <30 ng/ml. Participants were given oral ergocalciferol (50,000 IU/wk) for 8 weeks. Serum and 24-hour urine tests were repeated after 8 weeks.

Results
Levels of 25-hydroxyvitamin D increased significantly after vitamin D repletion (17±6 and 35±10 ng/ml, P<0.001), but mean 24-hour urinary calcium excretion did not change (257±54 and 255±88 mg/d at baseline and follow-up, respectively, P=0.91). However, 11 participants had an increase in urinary calcium excretion ≥20 mg/d; these participants also had an increase in urine sodium excretion, likely reflecting dietary variability. No participant experienced adverse effects from vitamin D, including hypercalcemia.

Conclusions
Among stone formers with vitamin D deficiency, a limited course of vitamin D repletion does not seem to increase mean urinary calcium excretion, although a subset of individuals may have an increase. These data suggest that vitamin D therapy, if indicated, should not be withheld solely on the basis of stone disease, but 24-hour urinary calcium excretion should be monitored after repletion.
Interaction of Feedback Frequency and Task Difficulty in Children's Motor Skill Learning
Authors: Sidaway Ben , Bates Justin , Occhiogrosso Barbara , Schlagenhaufer Jessica , Wilkes Delany 
Published: March 2012

BackgroundProviding adults with knowledge of results (KR) after each practice trial (100% KR) usually is found to be detrimental to motor skill learning compared with conditions in which feedback is less frequently provided. The effect of 100% KR on children's learning is less clear, with research showing that children with cerebral palsy benefit from less frequent KR, whereas children with typical development do not.ObjectiveThis study was designed to examine the interaction of KR frequency and task complexity on the acquisition, retention, and transfer of a novel throwing skill in fourth- and fifth-grade children with typical development.DesignThis was an observational study.MethodsChildren threw beanbags for accuracy at an unseen target while walking or while standing still. These 2 levels of task complexity were crossed with 2 frequencies (33% and 100%) of KR provision. Following practice, retention tests without feedback were performed 5 minutes later and then 1 week later along with transfer tests to assess the generalizability of learning.ResultsAnalyses revealed that learning was improved on the easy version of the task when a 33% KR frequency was provided during practice. In contrast, in the difficult version, learning was facilitated by provision of a 100% KR frequency during practice.ConclusionsStructuring practice conditions for children should take into account task complexity and feedback frequency in determining the cognitive challenge necessary for optimal skill learning. More generally, the findings suggest that practitioners teaching motor skills should design practice conditions in accordance with the cognitive processing capacity of the learner.
Biomechanical comparison of anterior cervical spine instrumentation techniques with and without supplemental posterior fusion after different corpectomy and discectomy combinations
Authors: Setzer Matthias , Eleraky Mohamed , Johnson Wesley M. , Aghayev Kamran , Tran Nam D. , Vrionis Frank D. 
Published: March 2012

Object
The objective of this study was to compare the stiffness and range of motion (ROM) of 4 cervical spine constructs and the intact condition. The 4 constructs consisted of 3-level anterior cervical discectomy with anterior plating, 1-level discectomy and 1-level corpectomy with anterior plating, 2-level corpectomy with anterior plating, and 2-level corpectomy with anterior plating and posterior fixation.

Methods
Eight human cadaveric fresh-frozen cervical spines from C2–T2 were used. Three-dimensional motion analysis with an optical tracking device was used to determine motion following various reconstruction methods. The specimens were tested in the following conditions: 1) intact; 2) segmental construct with discectomies at C4–5, C5–6, and C6–7, with polyetheretherketone (PEEK) interbody cage and anterior plate; 3) segmental construct with discectomy at C6–7 and corpectomy of C-5, with PEEK interbody graft at the discectomy level and a titanium cage at the corpectomy level; 4) corpectomy at C-5 and C-6, with titanium cage and an anterior cervical plate; and 5) corpectomy at C-5 and C-6, with titanium cage and an anterior cervical plate, and posterior lateral mass screw-rod system from C-4 to C-7. All specimens underwent a pure moment application of 2 Nm with regards to flexion-extension, lateral bending, and axial rotation.

Results
In all tested motions the statistical comparison was significant between the intact condition and the 2-level corpectomy with anterior plating and posterior fixation construct. All other statistical comparisons between the instrumented constructs were not statistically significant except between the 3-level discectomy with anterior plating and the 2-level corpectomy with anterior plating in axial rotation. There were no statistically significant differences between the 1-level discectomy and 1-level corpectomy with anterior plating and the 2-level corpectomy with anterior plating in any tested motion. There was also no statistical significance between the 3-level discectomy with anterior plating and the 2-level corpectomy with anterior plating and posterior fixation.

Conclusions
This study demonstrates that segmental plate fixation (3-level discectomy) affords the same stiffness and ROM as circumferential fusion in 2-level cervical spine corpectomy in the immediate postoperative setting. This obviates the need for staged circumferential procedures for multilevel cervical spondylotic myelopathy. Given that the posterior segmental instrumentation confers significant stability to a multilevel cervical corpectomy, the surgeon should strongly consider the placement of segmental posterior instrumentation to significantly improve the overall stability of the fusion construct after a 2-level cervical corpectomy.
What Drives States to Support Renewable Energy?
Authors: Jenner Steffen , Chan Gabriel , Frankenberger Rolf , Gabel Mathias 
Published: March 2012

Why do states support electricity generation from renewable energy sources? Lyon/Yin (2010), Chandler (2009), and Huang et al. (2007) have answered this question for the adoption of renewable portfolio standards (RPS) at the U.S. state level. This article supplements their work by testing the core hypotheses on the EU27 sample between 1990 and 2010. Furthermore, the article asks why the majority of EU states rely on feed-in-tariffs (FIT). The study conducts logistic time series cross-section regression analyses that run on a hazard model. Evidence in support of private interest theory and public interest theory is provided. (a) The existence of a solar energy association increases the probability of a state to adopt regulation. (b) Solar radiation, and(c) the unemployment rate also increase the odds. (d) Electricity market concentration decreases the probability of transition.
Composite fast‐slow MPC design for nonlinear singularly perturbed systems
Authors: Chen Xianzhong , Heidarinejad Mohsen , Liu Jinfeng , Christofides Panagiotis D. 
Published: March 2012

AbstractThe design of a composite control system for nonlinear singularly perturbed systems using model predictive control (MPC) is described. Specifically, a composite control system comprised of a “fast” MPC acting to regulate the fast dynamics and a “slow” MPC acting to regulate the slow dynamics is designed. The composite MPC system uses multirate sampling of the plant state measurements, i.e., fast sampling of the fast state variables is used in the fast MPC and slow‐sampling of the slow state variables is used in the slow MPC. Using singular perturbation theory, the stability and optimality of the closed‐loop nonlinear singularly perturbed system are analyzed. A chemical process example which exhibits two‐time‐scale behavior is used to demonstrate the structure and implementation of the proposed fast–slow MPC architecture in a practical setting. © 2012 American Institute of Chemical Engineers AIChE J, 58: 1802–1811, 2012
General framework and modeling approach classification for chemical production scheduling
Authors: Maravelias Christos T. 
Published: March 2012

AbstractDespite the increased number of publications in the area during the last two decades, there is no unified notation and systematic framework for chemical production scheduling. In this article, we first develop a framework for the description of scheduling problems in the chemical industries. While building upon ideas used in discrete manufacturing, the proposed framework accounts for features such as material handling restrictions which are critical in chemical production scheduling. Second, we present a classification of the various modeling approaches that have been presented in the process systems engineering literature. Our classification is broader than previous schemes because it accounts for more attributes, and it also offers a broader discussion of the modeling of time. We believe that our analysis will enhance the understanding of chemical production scheduling and lead to further advances in the area. © 2012 American Institute of Chemical Engineers AIChE J, 58: 1812–1828, 2012
A century of miners' compensation in South Africa
Authors: Ehrlich Rodney 
Published: March 2012

AbstractThe year 2011 marked the centenary of compensation legislation for miners' lung disease in South Africa. This commentary aims to demonstrate that the current compensation system does not serve its intended beneficiaries, particularly the large population of former gold miners affected by high rates of silicosis and tuberculosis. The system has a complex legislative history, reflecting contending political, and economic forces, and characterized by racial discrimination. The financial basis of the system is currently in crisis owing to historical underfunding and failure to take into account the mounting burden of disease among black former miners. The real value of compensation awards fell sharply between 1973 and 1993, only partly recovering in recent years. Barriers to claiming benefits, particularly by black former miners who know little about the process, have been extensively documented. Integration of miners' compensation into general workers' compensation has been mooted since the 1980s but has stalled, owing to the high cost of closing the gap between the mostly inferior financial benefits under the mining legislation and those available under workers' compensation legislation. A recent constitutional court decision has opened the way for unprecedented civil litigation against the gold mining industry for silicosis, adding to the pressure for reform. A number of changes are called for: harmonization of financial benefits with retention of certain of the special arrangements for miner claims, a regional cross‐border system of medical examination points for former miners, education of miners about the system, and some degree of privatization of claims processing. Am. J. Ind. Med. 55:560–569, 2012. © 2012 Wiley Periodicals, Inc.
Real time quaking‐induced conversion analysis of cerebrospinal fluid in sporadic Creutzfeldt–Jakob disease
Authors: McGuire Lynne I. , Peden Alexander H. , Orrú Christina D. , Wilham Jason M. , Appleford Nigel E. , Mallinson Gary , Andrews Mary , Head Mark W. , Caughey Byron , Will Robert G. , Knight Richard S. G. , Green Alison J. E. 
Published: March 2012

AbstractObjective:Current cerebrospinal fluid (CSF) tests for sporadic Creutzfeldt–Jakob disease (sCJD) are based on the detection of surrogate markers of neuronal damage such as CSF 14‐3‐3, which are not specific for sCJD. A number of prion protein conversion assays have been developed, including real time quaking‐induced conversion (RT‐QuIC). The objective of this study is to investigate whether CSF RT‐QuIC analysis could be used as a diagnostic test in sCJD.Methods:An exploratory study was undertaken that analyzed 108 CSF samples from patients with neuropathologically confirmed sCJD or from control patients. Of the 108 CSF samples, 56 were from sCJD patients (30 female, 26 male; aged 31–84 years; mean age, 62.3 ± 13.5 years), and 52 were from control patients (26 female, 26 male; aged 43–84 years; mean age, 67.8 ± 10.4 years). A confirmatory group of 118 patients was subsequently examined that consisted of 67 cases of neuropathologically confirmed sCJD (33 female, 34 male; aged 39–82 years; mean age, 67.5 ± 9.0 years) and 51 control cases (26 female, 25 male; aged 36–87 years; mean age, 63.5 ± 11.6 years).Results:The exploratory study showed that RT‐QuIC analysis had a sensitivity of 91% and a specificity of 98% for the diagnosis of sCJD. These results were confirmed in the confirmatory study, which showed that CSF RT‐QuIC analysis had a sensitivity and specificity of 87% and 100%, respectively.Interpretation:This study shows that CSF RT‐QuIC analysis has the potential to be a more specific diagnostic test for sCJD than current CSF tests. ANN NEUROL 2012;72:278–285.
Adaptive fault‐tolerant control based on hybrid redundancy
Authors: Takahashi Masanori , Takagi Taro 
Published: March 2012

ABSTRACTThis paper presents a new actuator fault accommodation based on a hybrid of static and dynamic redundancies. Introduction of the activation functions for the actuators makes it possible to switch the redundancy modes appropriately. These functions are switched among the two values, 0 and 1, by monitoring only the input and output signals, and they determine the power supplies for the actuators. Furthermore, in this paper, the adaptively switching high‐gain feedback controller is developed to achieve the λ‐tracking in the presence of unknown perturbations. The adaptive tracker is modified to suit the switching mechanism for tuning the activation‐functions. Thus, the proposed adaptive fault‐tolerant control system with a hybrid redundancy has the advantages of both static and dynamic redundancies, and has high robustness with regard to actuator failures and variations in dynamics. In addition, a practical application to a chemical reactor is shown to confirm the effectiveness of the overall adaptive fault‐tolerant control system. © 2012 Curtin University of Technology and John Wiley & Sons, Ltd.
Metal‐Ion Permeation in Congested Nanochannels: The Exposure Effect of Ag+ Ions on the Phosphorescent Properties of a Gold(I)–Pyrazolate Complex that is Confined in the Nanoscopic Channels of Mesoporous Silica
Authors: Lintang Hendrik O. , Kinbara Kazushi , Yamashita Takashi , Aida Takuzo 
Published: March 2012

AbstractAn organometallic/silica nanocomposite of a 1D cylindrical assembly of a trinuclear gold(I)–pyrazolate complex ([Au3Pz3]) that was confined inside the nanoscopic channels of hexagonal mesoporous silica ([Au3Pz3]/silicahex), emitted red light with a luminescence center at 693 nm upon photoexcitation at 276 nm owing to a AuIAuI metallophilic interaction. When a film of [Au3Pz3]/silicahex was dipped into a solution of Ag+ in tetrahydrofuran (THF), the resulting nanocomposite material (Ag@[Au3Pz3]/silicahex) emitted green light with a new luminescence center at 486 nm, which was characteristic of a AuIAgI heterometallic interaction. Changes in the emission/excitation and XPS spectra of Ag@[Au3Pz3]/silicahex revealed that Ag+ ions permeated into the congested nanochannels of [Au3Pz3]/silicahex, which were filled with the cylindrical assembly of [Au3Pz3].
Simultaneous determination of four shanzhiside methylester derivatives in rabbit plasma by liquid chromatography/tandem mass spectrometry
Authors: Fan Peng‐Cheng , Li Mao‐Xing , Ma Hui‐Ping , Jing Lin‐lin , Qiu Jian‐guo , Jia Zheng‐Ping 
Published: March 2012

ABSTRACTA simple and sensitive high‐performance liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed and validated for simultaneous determination of shanzhiside methylester and its three derivatives in rabbit plasma. The method showed good linearity and no endogenous material interfered with the marked compounds and internal standard (IS) capatol peaks. Samples were processed by acetonitrile precipitation. Chromatography was performed using a C18 column (150 × 3.9 mm i.d., 4 µm). The mobile phase consisted of methanol and water (60:40, v/v) during a total run time of 7 min. The main mass parent ions and daughter ions pairs (m/z) for monitoring were: shanzhiside methylester, 429.0/267.4; 8‐O‐acetyl shanzhiside methylester, 470.9/411.3; loganin, 413.2/251.4; phloyoside II, 479.2/281.3; and IS 385.2/203.3. Finally, the method was applied to a pharmacokinetic study of rabbits following intravenous administration of iridoid glycosides extracted from traditional herb Lamiophlomis rotata. Copyright © 2012 John Wiley & Sons, Ltd.
Antifeedant Activity of Fatty Acid Esters and Phytosterols from Echium wildpretii
Authors: Santana Omar , Reina Matias , Fraga Braulio M. , Sanz Jesús , González‐Coloma Azucena 
Published: March 2012

AbstractCrude extracts and fractions from Echium wildpretii H. Pearson ex Hook. f. subsp. wildpretii (Boraginaceae) have been tested against insect species Spodoptera littoralis, Leptinotarsa decemlineata, and the aphids Myzus persicae, Diuraphis noxia, Metopolophium dirhodum, Rhopalosiphum maidis, and Rhopalosiphum padi. The EtOH extract and the lipid and steroidal fractions of E. wildpretii exhibited significant antifeedant activities against the aphids and L. decemlineata. Two bioactive mixtures composed of fatty acid esters and n‐alkanes were obtained from the lipid fraction. The bioguided fractionation of the steroidal fraction resulted in the isolation of glutinol, β‐sitosterol, (3β,7α)‐stigmast‐5‐ene‐3,7‐diol, and (3β,7α)‐7‐methoxystigmast‐5‐en‐3‐ol. The latter two compounds exhibited potent antifeedant activities against L. decemlineata indicating that the presence of an O‐bearing C(7) was responsible for the activities of these molecules.
Composition and Antibacterial Activity of the Essential Oils of Four Commercial Grades of Omani Luban, the Oleo‐Gum Resin of Boswellia sacraFlueck.
Authors: Al‐Saidi Salim , Rameshkumar K. B. , Hisham Abdulkhader , Sivakumar Nallusamy , Al‐Kindy Salma 
Published: March 2012

AbstractThe essential oil compositions of four botanically certified and commercially available samples of Omani lubans (oleo‐gum resins of Boswellia sacra Flueck.), locally known as Hoojri, Najdi, Shathari, and Shaabi in Jibali Arabic, obtained from plants growing in four different geographic locations of the Dhofar region of Oman, were analyzed by GC‐FID, GC/MS, and 13C‐NMR spectroscopy. The market price of these four grades of lubans differed considerably, according to their color, clump size, and texture. However, this study revealed that Hoojri, the first grade luban, and Shaabi, the fourth grade luban, which greatly differed in their price, closely resembled each other in their essential oil composition, yield, and physicochemical characteristics, except the color and texture. The composition, yield, and specific rotation of the oils of Najdi and Shathari, the second and the third grade lubans, respectively, were different from those of Hoojri and Shaabi, but they both had high limonene contents. Najdi oil was different from the other three oils in terms of its high myrcene content. α‐Pinene was the principal component in all the oils and can be considered as a chemotaxonomical marker that confirms the botanical and geographical source of the resins. All the oils showed pronounced activity against a panel of bacteria, and the trend in their bioactivity and their mode of action are discussed.
Defensive Sesquiterpenes from Senecio candidans and S. magellanicus, and Their StructureActivity Relationships
Authors: Reina Matías , Santana Omar , Domínguez Dulce M. , Villarroel Luis , Fajardo Víctor , Rodríguez Matías L. , González‐Coloma Azucena 
Published: March 2012

AbstractEleven eremophilanolides, 1–3 and 6–13, and two eremophilanes, 24 and 25, were isolated from Senecio candidans and S. magellanicus from the Magallanes Region (Chile). Compounds 2, 3, 9, and 10 have not been previously reported as natural products. Their structures were established by NMR spectroscopic analysis and chemical transformations. The X‐ray analysis of compounds 11, 13, and 17 were also performed. Different semisynthetic analogs from eremophilanolide 11 were generated to carry out a structureactivity relationship study. Their possible plant defensive role was tested against herbivorous insects (Spodoptera littoralis, Rhopalosiphum padi, and Myzus persicae) and plants (Lactuca sativa). Additionally, their effects on insect (Sf9) and mammalian (CHO) cell lines were tested.