bluuebunny/crossref_metadata_2025 huggingface dataset:
Gender and the Construction of Intimacy among Committed Couples with Children
Authors: Reynolds Conroy , Knudson‐Martin Carmen
Published: September 2014

This study began with curiosity regarding how long‐term couples with children manage their relationships in view of changing societal demands and ideals. Couples interviewed for this study described the intersection of time and intimacy as a core issue. Thus, this analysis focused on how couples construct intimacy in shared time. The diverse sample included 17 heterosexual working and professional class couples in the United States who had been committed for at least 10 years and whose oldest child was aged 6–16. Analysis identified four types of shared time experiences: gender divided, elusive, growing, and emotionally connected. Four factors influenced these types: (a) negotiated gendered differences, (b) intentionality, (c) mutual attending, and (d) dyadic friendship. The most emotionally connected couples reported that time together reinforced satisfaction and pleasure from their relationships. Results help explain different ways couples successfully negotiate changing expectations for heterosexual relationships and why some couples struggle. Findings suggest that therapists help couples intentionally develop habits of friendship and mutual attending.
Distinct conformational behaviors of four mammalian dual‐flavin reductases (cytochrome P450 reductase, methionine synthase reductase, neuronal nitric oxide synthase, endothelial nitric oxide synthase) determine their unique catalytic profiles
Authors: Haque Mohammad M. , Bayachou Mekki , Tejero Jesus , Kenney Claire T. , Pearl Naw M. , Im Sang‐Choul , Waskell Lucy , Stuehr Dennis J.
Published: September 2014

Multidomain enzymes often rely on large conformational motions to function. However, the conformational setpoints, rates of domain motions and relationships between these parameters and catalytic activity are not well understood. To address this, we determined and compared the conformational setpoints and the rates of conformational switching between closed unreactive and open reactive states in four mammalian diflavin NADPH oxidoreductases that catalyze important biological electron transfer reactions: cytochrome P450 reductase, methionine synthase reductase and endothelial and neuronal nitric oxide synthase. We used stopped‐flow spectroscopy, single turnover methods and a kinetic model that relates electron flux through each enzyme to its conformational setpoint and its rates of conformational switching. The results show that the four flavoproteins, when fully‐reduced, have a broad range of conformational setpoints (from 12% to 72% open state) and also vary 100‐fold with respect to their rates of conformational switching between unreactive closed and reactive open states (cytochrome P450 reductase > neuronal nitric oxide synthase > methionine synthase reductase > endothelial nitric oxide synthase). Furthermore, simulations of the kinetic model could explain how each flavoprotein can support its given rate of electron flux (cytochrome c reductase activity) based on its unique conformational setpoint and switching rates. The present study is the first to quantify these conformational parameters among the diflavin enzymes and suggests how the parameters might be manipulated to speed or slow biological electron flux.
Expression of glutamatergic genes in healthy humans across 16 brain regions; altered expression in the hippocampus after chronic exposure to alcohol or cocaine
Authors: Enoch M.‐A. , Rosser A. A. , Zhou Z. , Mash D. C. , Yuan Q. , Goldman D.
Published: September 2014

We analyzed global patterns of expression in genes related to glutamatergic neurotransmission (glutamatergic genes) in healthy human adult brain before determining the effects of chronic alcohol and cocaine exposure on gene expression in the hippocampus. RNA‐Seq data from ‘BrainSpan’ was obtained across 16 brain regions from nine control adults. We also generated RNA‐Seq data from postmortem hippocampus from eight alcoholics, eight cocaine addicts and eight controls. Expression analyses were undertaken of 28 genes encoding glutamate ionotropic (AMPA, kainate, NMDA) and metabotropic receptor subunits, together with glutamate transporters. The expression of each gene was fairly consistent across the brain with the exception of the cerebellum, the thalamic mediodorsal nucleus and the striatum. GRIN1, encoding the essential NMDA subunit, had the highest expression across all brain regions. Six factors accounted for 84% of the variance in global gene expression. GRIN2B (encoding GluN2B), was up‐regulated in both alcoholics and cocaine addicts (FDR corrected P = 0.008). Alcoholics showed up‐regulation of three genes relative to controls and cocaine addicts: GRIA4 (encoding GluA4), GRIK3 (GluR7) and GRM4 (mGluR4). Expression of both GRM3 (mGluR3) and GRIN2D (GluN2D) was up‐regulated in alcoholics and down‐regulated in cocaine addicts relative to controls. Glutamatergic genes are moderately to highly expressed throughout the brain. Six factors explain nearly all the variance in global gene expression. At least in the hippocampus, chronic alcohol use largely up‐regulates glutamatergic genes. The NMDA GluN2B receptor subunit might be implicated in a common pathway to addiction, possibly in conjunction with the GABAB1 receptor subunit.
Colorectal serrated pathway cancers and precursors
Authors: O'Brien Michael J , Zhao Qing , Yang Shi
Published: September 2014

The serrated pathway (SP) can be viewed as two parallel, but partially overlapping, arrays of colorectal precursor lesions, and their respective endpoint carcinomas, that are distinct from those of the conventional adenoma–carcinoma sequence (APC‐pathway). In this review we focus at the outset on the clinical impact, pathological features, molecular genetics and biological behaviours of the various SP cancers. Then we summarize the clinicopathological features, classification and molecular profiles of the two main precursor lesions that anchor the respective pathways: (i) sessile serrated adenoma/polyp (SSA/P), also called sessile serrated lesion (SSL), and (ii) traditional serrated adenoma (TSA). Activating mutations of the RAS–RAF–MAPK pathway initiate and sustain the lesions of the SP, and CpG island methylation of the promoter regions of tumour suppressor and DNA repair genes play the major role in their neoplastic progression. The SP includes microsatellite stable (MSS) carcinomas that are among the most biologically aggressive colorectal carcinomas (CRC), and also accounts for the great preponderance of sporadic hypermutated, mismatch repair (MMR)‐deficient or microsatellite instable (MSI) CRC. The identification, removal and appropriate classification of at‐risk SP precursors and surveillance of individuals who harbour these lesions present a challenge and opportunity for CRC prevention and mortality reduction.
Temperature rise on the surface of NiTi and stainless steel fractured instruments during ultrasonic removal
Authors: Madarati A. A.
Published: September 2014

Aim

To investigate the temperature rise induced by ultrasonic tips when activated against two types of fragments at two power‐settings.

Methodology

Twenty‐four F2‐ProTaper Universal rotary files and 36 stainless steel K‐files, size 50, were sectioned at a point 5.5 mm from their tips. At specific power‐settings, ET40D ultrasonic tips were activated against the peripheral surface of the fragment coronal part (1 mm) for 30 s with/without Air‐Active function according to each group; (i) without Air‐Active function at power‐setting 1.5 against NiTi fragments, (ii) without Air‐Active function at power‐setting 1.5 against SS fragments, (iii) without Air‐Active function at power‐setting 3 against SS fragments, (iv) with Air‐Active function at power‐setting 3 against SS fragments, and (v) with Air‐Active at power‐setting 3 against NiTi fragments. Temperature rises were inspected at 15 and 30 s using the thermocouples.

Results

With no Air‐Active function and power‐setting 1.5, the temperature rises induced on NiTi fragments at 15 and 30 s (36.33 and 55.44 °C, respectively) were significantly greater than those induced on SS fragments at 15 and 30 s (26.08 and 35.27 °C, respectively) (P = 0.001 and <0.001, respectively). When ultrasonic tips were activated against SS fragments without Air‐Active, the temperature rises induced by power‐setting 3 at 15 and 30 s (35.25 and 45.32 °C, respectively) were significantly greater than those induced by power‐setting 1.5 at the same intervals (26.08 and 35.27 °C, respectively) (P = 0.006 and 0.012, respectively). At 30 s, the overall temperature rise induced with Air‐Active (25.56 °C) was significantly lower than that induced without Air‐Active (45.34 °C) (P < 0.001).

Conclusions

Lower power‐settings and shorter application times are recommended when using ultrasonics for removal of NiTi fragments compared with SS ones. Air‐Active function, as a coolant, is recommended when dealing with both types of fragments.
Evaluation of the mechanical behaviour of PathFile and ProGlider pathfinding nickel–titanium rotary instruments
Authors: Elnaghy A. M. , Elsaka S. E.
Published: September 2014

Aim

To assess and compare the resistance to cyclic fatigue, torsional stress, bending and buckling of ProGlider (PG; Dentsply Maillefer, Ballaigues, Switzerland) instruments with PathFile (PF; Dentsply Maillefer) pathfinding nickel–titanium rotary instruments.

Methodology

Size 16, .02 taper PG and PF instruments were rotated in simulated canals until failure, and the number of cycles to failure (NCF) was recorded to evaluate their cyclic fatigue resistance. Torsional strength was measured using a torsiometer after fixing rigidly the apical 5 mm of the instrument. A scanning electron microscope was used to characterize the topographic features of the fracture surfaces of the instruments. The instruments were evaluated for bending resistance using a cantilever‐bending test. The buckling resistance was measured by recording the maximum load required to form a lateral elastic displacement along the file axis using a universal testing machine. Data were statistically analysed using independent t‐tests. Statistical significance was set at P < 0.05.

Results

ProGlider instrument had a significantly higher flexibility, higher resistance to cyclic fatigue and torsional stress than PF instruments (P < 0.05). The fractured cross‐sectional surfaces revealed typical features of cyclic fatigue and torsional fractures. There was no significant difference in the maximum load needed to buckle the two instruments tested (P = 0.082).

Conclusions

ProGlider NiTi pathfinding instrument manufactured from M‐Wire alloy had enhanced mechanical properties, including higher flexibility, higher resistance to cyclic fatigue and torsional stress compared with PathFile instrument made of conventional NiTi alloy.
Polymorphisms in the TNF‐α, TNFR1 gene and risk of rheumatoid arthritis in Chinese Han population
Authors: Li F. , Gao J. , Sokolove J. , Xu J. , Zheng J. , Zhu K. , Pan Z.
Published: September 2014

Recent advances have highlighted a major genetic contribution to the pathogenesis of rheumatoid arthritis (RA).The aim of this study was to investigate whether polymorphisms of TNF‐α (rs1800630, rs1800629) and TNFR1 (rs767455) were associated with susceptibility to and clinical outcome of RA in Chinese Han population. The target gene polymorphisms were genotyped in 256 patients with RA and 331 healthy controls using a high resolution melting (HRM) method. ESR, CRP, RF anti‐CCP and anti‐GPI level were also assayed and compared in genotypes of each polymorphism. Significant difference was observed in the genotype distributions and allele frequencies of TNF‐α rs1800629 (P = 0.001, P < 0.001, respectively) between patients with RA and controls. There is no evidence to suggest an association between genotypes of the 3 SNPs according to age, gender, disease duration, DAS28 and serum level of autoantibodies. This study identifies a potentially important role for TNF‐α rs1800629 polymorphisms in the susceptibility to RA.However, further studies in larger cohorts are required.
The effect of various backfilling techniques on the fracture resistance of simulated immature teeth performed apical plug with Biodentine
Authors: Topçuoğlu Hüseyin Sİnan , Kesİm Bertan , Düzgün Salih , Tuncay Öznur , Demİrbuga Sezer , Topçuoğlu Gamze
Published: September 2014

Aim

To evaluate the fracture resistance of simulated immature teeth that had been backfilled using different materials after using Biodentine as the apical plug material.

Design

Seventy‐five single‐rooted teeth were divided into five groups (n = 15). The 15 teeth in group 1 served as a negative control group and received no treatment. The remaining 60 teeth were instrumented to a #6 Peeso reamer to obtain a standard internal diameter of 1.5 mm. The apical 4 mm of 60 teeth was filled with Biodentine. The backfilling was then performed on each group as follows: group 2 – no backfilling (positive control), group 3 – gutta‐percha, group 4 – fiber post, and group 5 – Biodentine. Specimens were then subjected to fracture testing. The force required to fracture each specimen was recorded, and the data were statistically analyzed.

Results

The mean fracture values of groups 1 and 4 were significantly higher than groups 2, 3, and 5 (P < 0.05). The values of groups 3 and 5 were significantly higher than group 2 (P < 0.05).

Conclusions

The backfilling with fiber post after an apical Biodentine plug provided the highest fracture resistance among all experimental groups.
Effects of the N/L‐Type Calcium Channel Blocker Cilnidipine on Nephropathy and Uric Acid Metabolism in Hypertensive Patients With Chronic Kidney Disease (J‐CIRCLE Study)
Authors: Uchida Shunya , Takahashi Masato , Sugawara Masahiro , Saito Tomoaki , Nakai Kazuhiko , Fujita Masami , Mochizuki Koichi , Shin Isu , Morita Takashi , Hikita Tomoyuki , Itakura Hironao , Takahashi Yuko , Mizuno Shigeki , Ohno Yasumi , Ito Kageki , Ito Takafumi , Soma Masayoshi
Published: September 2014

This study assessed the urinary albumin/creatinine ratio (ACR) and uric acid metabolism in 70 hypertensive patients with chronic kidney disease in whom urinary ACR had remained ≥30 mg/g under the treatment of the L‐type calcium channel blocker amlodipine. Three months after switching to the N/L‐type calcium channel blocker cilnidipine, blood pressure (BP) did not change; however, urinary ACR significantly decreased with cilnidipine. Serum uric acid levels showed no significant change. In cases where uric acid production had been high (urinary uric acid/creatinine ratio ≥0.5), the urinary uric acid/creatinine ratio decreased significantly after cilnidipine treatment, suggesting that cilnidipine can suppress excessive uric acid formation. These results suggest that switching from amlodipine to cilnidipine results in a significant reduction in urinary ACR as well as significant reduction in uric acid production. Thus, cilnidipine is more useful than amlodipine in improving albuminuria and uric acid metabolism in hypertensive patients with chronic kidney disease.
How do child and adolescent mental health problems influence public sector costs? Interindividual variations in a nationally representative British sample
Authors: Knapp Martin , Snell Tom , Healey Andrew , Guglani Sacha , Evans‐Lacko Sara , Fernandez Jose‐Luis , Meltzer Howard , Ford Tamsin
Published: September 2014

Background

Policy and practice guidelines emphasize that responses to children and young people with poor mental health should be tailored to needs, but little is known about the impact on costs. We investigated variations in service‐related public sector costs for a nationally representative sample of children in Britain, focusing on the impact of mental health problems.

Methods

Analysis of service uses data and associated costs for 2461 children aged 5–15 from the British Child and Adolescent Mental Health Surveys. Multivariate statistical analyses, including two‐part models, examined factors potentially associated with interindividual differences in service use related to emotional or behavioural problems and cost. We categorized service use into primary care, specialist mental health services, frontline education, special education and social care.

Results

Marked interindividual variations in utilization and costs were observed. Impairment, reading attainment, child age, gender and ethnicity, maternal age, parental anxiety and depression, social class, family size and functioning were significantly associated with utilization and/or costs.

Conclusions

Unexplained variation in costs could indicate poor targeting, inequality and inefficiency in the way that mental health, education and social care systems respond to emotional and behavioural problems.
A simple logistic model to understand the occurrence of flood events into the Biobío River Basin in central Chile
Authors: Fustos I. , Abarca‐del‐Rio R. , Ávila A. , Orrego R.
Published: September 2014

We predict flood events by fitting two simple logistic regression models between mesoscale rainfall and El Niño‐Southern Oscillation (ENSO) index with local scale flooding into the Biobío River Basin in Chile from 1948 to 2002. Two different and complementary logistic models were studied: Logit and Probit. The models perform alike suggesting that the methodology is robust. The best model is most accurate during the autumn over 80% hit rate and in winter 66% hit rate, which are the seasons with high risk of floods. This work represents a first step in the development of a complete hydrological framework for the Biobío River Basin. The Logit distribution shows better results; thus, we suggest to use this distribution to relate flood events with mesoscale precipitation and ENSO index in the Biobío River Basin. Finally, these results explain the flood events and its relation with risk management. In forthcoming studies we will extend the methodology over this region and Chile taking advantage of the availability of higher resolution (temporal and spatial) weather products along with investigating climatic patterns and Intergovernmental Panel on Climate Change (IPCC) climate change scenarios.
Molecular epidemiology of and genetic susceptibility to esophageal cancer
Authors: Bajpai Manisha , Das Kiron M. , Lefferts Joel , Lisovsky Mikhail , Mashimo Hiroshi , Phillips Wayne A. , Srivastava Amitabh , To Henry
Published: September 2014

The following, from the 12th OESO World Conference: Cancers of the Esophagus, includes commentaries on clonal evolution in Barrett's carcinogenesis; biomarkers for early detection of esophageal cancer; the role of the methylguanine methyl transferase biomarker in the management of adenocarcinoma; and the discovery of high‐risk genes in families.
Immune signaling and regulation in esophageal cancer
Authors: Calpe Silvia , Compare Debora , Mari Luigi , Nardone Gerardo , Parikh Kaushal
Published: September 2014

The following, from the 12th OESO World Conference: Cancers of the Esophagus, includes commentaries on signaling pathways that can be targeted with immunotherapy; the role of micro‐RNAs in the immune response to esophageal cancer; and the association between obesity, the immune system, and esophageal adenocarcinoma.
Progression of esophageal dysplasia to cancer
Authors: Appelman Henry D. , Matejcic Marco , Parker M. Iqbal , Riddell Robert H. , Salemme Marianna , Swanson Paul E. , Villanacci Vincenzo
Published: September 2014

The following, from the 12th OESO World Conference: Cancers of the Esophagus, includes commentaries on the evolution of low‐grade squamous and glandular dysplasia to invasive carcinoma; the mutational spectra of Barrett's esophagus and adenocarcinoma; the risk of p53‐immunoreactive glandular dysplasia compared to non‐immunoreactive mucosa for progression to cancer; the role of lectins in progression to adenocarcinoma; and the role of racemase immunoreactivity in the prediction of risk of adenocarcinoma.
Strategy for prevention of cancers of the esophagus
Authors: Akiyama Junichi , Alexandre Leo , Baruah Anushka , Buttar Navtej , Chandra Raghav , Clark Allan B. , Hart Andrew R. , Hawk Ernest , Kandioler Daniela , Kappel Sonja , Krishnadath Sheila K. , Sharma Anamay , Singh Ishtpreet , Straub Danielle , Triadafilopoulos George , Umar Asad , Wolf Brigitte
Published: September 2014

The following, from the 12th OESO World Conference: Cancers of the Esophagus, includes commentaries on the animal reflux–inflammation models for Barrett's esophagus and esophageal adenocarcinoma; genomic/epigenomic analyses; eflornithine‐based combinations; the molecular derangements that promote neoplastic transformation; the role of COX‐2 inhibitors, proton pump inhibitors, and phase II trials in Barrett's adenocarcinoma; statins in chemoprevention and treatment of esophageal cancer; and biomarkers as potential targets in Barrett's adenocarcinoma.
Benign and precursor lesions in the esophagus
Authors: Akiyama Junichi , Bertelé Anna , Brock Christina , Hvid‐Jensen Frederik , Ichiya Tamaki , Krarup Anne Lund , Majewski Marek , Rubio Carlos A. , Sarosiek Jerzy , Scarpignato Carmelo , Schmidt Peter Thelin , Teich Steven , Triadafilopoulos George , Wallner Grzegorz
Published: September 2014

The following, from the 12th OESO World Conference: Cancers of the Esophagus, includes commentaries on the role of salivary stimulation and esophageal secretion of protective factors in prevention of adenocarcinoma sequelae in gastroesophageal reflux disease; the pediatric conditions associated with esophageal cancer; the relationship of achalasia and pseudoachalasia with esophageal cancer; the potential for malignant transformation in eosinophilic esophagitis and overlap syndromes; the role of lymphocytic esophagitis as an overlapping phenotype; the role of Barrett's esophagus as a premalignant condition; the indications and type of treatment of premalignant conditions of the esophagus; and the decision for use of endoscopical procedures in premalignant conditions of the esophagus.
Impact of weight cycling on risk of morbidity and mortality
Authors: Mehta T. , Smith D. L. , Muhammad J. , Casazza K.
Published: September 2014

Unintentional weight gain is commonly observed in adult humans, often provoking intentional weight loss attempts followed by unintentional weight regain. This episodic variation in body weight over a period of time has been referred to as ‘weight cycling’. Over the last two decades, weight cycling has been associated with a number of morbid health conditions and increased mortality. This article provides a comprehensive evaluation of recent weight‐cycling evidence, looks to understand design differences between studies and study outcomes, assesses the need for further research on particular health outcomes, and proposes alternative methodologies that will bridge the needs and capabilities of research. Searches were conducted per PRISMA guidelines. Articles on weight cycling in the literature were initially identified using search strings in PubMed. Eligibility assessment of the remaining articles was performed independently by three reviewers to identify publications that presented direct evidence. Twenty human studies (in addition to seven animal studies) were selected and retained; 12 accounted for the intentionality of weight loss. Although weight regain following successful weight loss remains one of the most challenging aspects of body‐weight regulation, evidence for an adverse effect of weight cycling appears sparse, if it exists at all.
Comparison of Templating Abilities of Urea and Thioruea During Photodimerization of Bipyridylethyelene and Stilbazole Crystals
Authors: Bhogala Balakrishna R. , Captain Burjor , Ramamurthy Vaidhyanathan
Published: September 2014

Photodimerization of cocrystals of four bispyridylethylenes and two stilbazoles with urea as a template in the solid state has been investigated following our success with thiourea. Four investigated olefins photodimerized quantitatively to a single dimer in the crystalline state only. The reactivity of urea–olefin crystals is understood on the basis of their packing arrangements in the crystalline state. In reactive crystals the adjacent reactive molecules are within 4.2 Å and parallel, whereas the unreactive ones have their adjacent molecules are farther than 4.6Å and nonparallel. Thus, with the knowledge of crystal packing the reactivity of urea–olefin crystals is predictable on the basis of Schmidt's topochemical postulates. The templating property of urea, similar to thiourea, derives from its ability to form hydrogen bonds with itself and the guest olefins. Despite the similarities in molecular structures of urea and thiourea their subtle electronic properties, yet to be fully understood, affect the crystal packing and consequently their reactivity in the crystalline state. Further work is needed to fully exploit the templating properties of urea.
Supply Contract Design for Competing Heterogeneous Suppliers under Asymmetric Information
Authors: Li Zhaolin , Ryan Jennifer K. , Shao Lusheng , Sun Daewon
Published: September 2014

This study considers a supply chain with two heterogeneous suppliers and a common retailer whose type is either low‐volume or high‐volume. The retailer's type is unknown to the suppliers. The flexible supplier has a high variable cost and a low fixed cost, while the efficient supplier has a low variable cost and a high fixed cost. Each supplier offers the retailer a menu of contracts. The retailer chooses the contract that maximizes its expected profit. For this setting, we characterize the equilibrium contract menus offered by the suppliers to the retailer. We find that the equilibrium contract menus depend on which supplier–retailer match can generate the highest supply chain profit and on how much information rent the supplier may need to pay. An important feature of the equilibrium contract menus is that the contract assigned to the more profitable retailer will coordinate the supply chain, while the contract assigned to the less profitable retailer may not. In addition, in some circumstances, the flexible supplier may choose not to serve the high‐volume retailer, in order to avoid excessive information rent.
Zircon U–Pb Age and Deformation Characteristics of the Jiama Porphyry Copper Deposit, Tibet: Implications for Relationships between Mineralization, Structure and Alteration
Authors: Duan Jilin , Tang Juxing , Mason Russell , Zheng Wenbao , Ying Lijuan
Published: September 2014

The Jiama copper deposit is one of the largest deposits recently found in Tibet and is composed of three types of mineralization including skarn, hornfels and porphyry. To investigate the relationship between mineralization, structure and alteration, we report new zircon U–Pb age and present field observations on the deformation characteritics associated with the copper mineralization in Jiama. Two main periods of deformation were identified, represented by D1 and D2 in Jiama. The first deformation (D1) occurred around 50 Ma, whereas the second deformation (D2) that was closely related to mineralization occurred later. Previous zircon U–Pb and molybnite Re–Os dating results indicate that the mineralizatoin occurred at ∼15 Ma and thus the D1 regional deformation significantly occurred before the mineralization time, although the D1 deformation probably provided important space for the development of significant copper deposition. Our new mapping and observations on the D2 deformation demonstrate that the mineralization was closely coeval with or slightly later than the time of D2 deformation. The new U–Pb zircon age further indicates that the aplite formed in ∼17.0 Ma and thus the D2 deformation happened later than this time because the D2 deformation cut across the aplite, which is proposed to be the key control for copper mineralization. Altered laminated hornfels including three types of alteration (A‐, K‐ and S‐type) were found spatially associated with the D2 deformation. The type‐A is mainly silicification, with fine sericite or chlorite, as well as abundant disseminated sulphides on fracture surfaces; the type‐S is mainly fine‐grained silicification with patches of chlorite, epidote and common sulphides; the type‐K (potassic alteration) appears to be fine‐grained biotite. Such types of alteration indicate the presence of skarns at depth where ore shoots are located. Taken together, the multiple structural‐magmatic‐mineralization events contributed to the formation of the supergiant Jiama porphyry copper deposit in Tibet. The results have general implication for regional exploration.
Some Pertinent Features of Mo‐Mineralized Granitoids in the Circum‐Pacific Region
Authors: Ishihara Shunso , Qing Kezhang
Published: September 2014

Petrological characteristics of granitic rocks related to the world large molybdenum deposits are studied. The granitoids are evaluated by Fe2O3+TiO2‐FeO+MnO‐MgO diagrams, and found to all plot to the magnetite‐series field. They are all high silica and high‐K series, but not A‐type, except for the Climax‐type porphyries and some others in the Colorado mineral belt. By‐product molybdenum contained in porphyry copper deposits, lower grade but huge tonnage, occurs with calc‐alkaline I‐type magnetite‐series granodiorite and monzogranite.

Felsic intrusive rocks of the Climax mine are A‐type and are exceptionally high in trace elements such as F and Rb, which are generally enriched with W and Sn‐related granitoids that originated in crustal source rocks. The by‐product molybdenites in porphyry copper deposits appear to originate in adakitic granodiorite or monzogranite, having deep origins with the subducted slab or thickened juvenile mafic lower crust. Therefore, there is no single magma type but the magnetite series, which concentrates a large volume of molybdenum in the ore deposits.
Magnetite Dyke in Precambrian Banded Iron Formation, Singhbhum Craton, India: Mineralogical and Chemical Characteristics
Authors: Nayak Prasanta Kumar , Mohapatra Birendra Kumar , Singh Prem Prakash
Published: September 2014

Banded iron formation (BIF) of the Gorumahisani–Sulaipat–Badampahar (GSB) belt in Singhbhum Craton, India, consists predominantly of magnetite. This BIF is intruded by a magnetite dyke. The magnetite dyke is massive and compact with minor sulphide minerals while the host banded magnetite ore, a component of the BIF, shows thin lamination. The magnetite ore of the dyke is fine to medium grained and exhibits interlocking texture with sharp grain boundaries, which is different from the banded magnetite that is medium to coarse grained and show irregular martitised and goethitised grain boundaries. Relics of Fe–Ca–Mn–Mg‐carbonate and iron silicates (grunerite and cummingtonite) are observed in the banded magnetite. The intrusive magnetite is distinctly different in minor, trace and REE geochemistry from the banded magnetite. The banded magnetite contains higher amounts of Si, Al, Mn, Ca, Mg, Sc, Ga, Nb, Zr, Hf, Co, Rb and Cu. In contrast, the massive magnetite is enriched in Cr, Zn, V, Ni, Sr, Pb, Y, Ta, Cs and U with higher abundance of HREE. In the chondrite normalized plot, the massive magnetite shows a slight positive Eu anomaly while the banded ore does not show any Eu anomaly. Field disposition, morphology, mineralogy and chemistry show that the intrusive magnetite dyke is of igneous origin, while magnetite in BIF formed from a carbonate protolith through the process of sedimentation.
Acute effect of Snus on physical performance and perceived cognitive load on amateur footballers
Authors: Morente‐Sánchez J. , Zandonai T. , Mateo‐March M. , Sanabria D. , Sánchez‐Muñoz C. , Chiamulera C. , Zabala Díaz M.
Published: September 2014

Smokeless tobacco (Snus) is a substance that contains nicotine, which has been placed on World Anti‐Doping Agency's 2014 Monitoring Program. A proliferation of nicotine use in sport has been observed in recent years, but little is known regarding its effects, especially on football players' performance. Therefore, the aim of this study was to assess the effect of Snus on physical performance, heart rate variability, subjective activation, mental fatigue, and perceived readiness before a physical test in non‐smoker, non‐Snus user, amateur football players. Participants were administered either Snus or placebo 40 min prior to a fitness test battery (handgrip test, countermovement jump, agility test, and Yo‐Yo intermittent recovery test). Results showed that Snus intake (compared with placebo) increased perceived mental fatigue level and mental load, and reduced perceived readiness level and heart rate variability. No significant differences between the two experimental conditions were found in either performance in the physical tests or perceived physical fatigue levels. In light of these results, Snus could not be considered an ergogenic substance. On the contrary, based on the extant evidence linking mental load and fatigue with physical performance, we argue that the observed negative effects on mental fatigue, perceived readiness, and heart rate variability should be considered.
Adjustments of muscle capillarity but not mitochondrial protein with skiing in the elderly
Authors: van Ginkel S. , Amami M. , Dela F. , Niederseer D. , Narici M. V. , Niebauer J. , Scheiber P. , Müller E. , Flück M.
Published: September 2014

Downhill skiing in the elderly increases maximal oxygen uptake (VO2max) and carbohydrate handling, and produces muscle hypertrophy. We hypothesized that adjustments of the cellular components of aerobic glucose combustion in knee extensor muscle, and cardiovascular adjustments, would increase in proportion to VO2max. Nineteen healthy elderly subjects (age 67.5 ± 2.9 years) who completed 28.5 days of guided downhill skiing over 3 months were assessed for anthropometric variables, cardiovascular parameters (heart rate, hematocrit), VO2max, and compared with controls (n = 20). Biopsies of vastus lateralis muscle were analyzed for capillary density and expression of respiratory chain markers (NDUFA9, SDHA, UQCRC1, ATP5A1) and the glucose transporter GLUT4. Statistical significance was assessed with a repeated analysis of variance and Fisher's post‐hoc test at a P value of 5%. VO2max increased selectively with ski training (+7 ± 2%). Capillary density (+11 ± 5%) and capillary‐to‐fiber ratio (12 ± 5%), but not the concentration of metabolic proteins, in vastus lateralis were increased after skiing. Cardiovascular parameters did not change. Fold changes in VO2max and capillary‐to‐fiber ratio were correlated and were under genetic control by polymorphisms of the regulator of vascular tone, angiotensin converting enzyme. The observations indicate that increased VO2max after recreational downhill ski training is associated with improved capillarity in a mainly recruited muscle group.
DISPERSAL PATTERN OF INJECTATE FOLLOWING CT‐GUIDED PERINEURAL INFILTRATION IN THE CANINE THORACOLUMBAR SPINE: A CADAVER STUDY
Authors: Kneissl Sibylle , Breit Sabine , Willmitzer Florian , Thalhammer Johann , Dengg Sabine
Published: September 2014

An increasing proportion of canine patients are presented with chronic thoracolumbar back pain and without compressive spinal lesions. In humans, spinal perineural infiltrations have been reported to have a favorable effect on pain control. The purpose of this prospective cadaver study was to describe the dispersal pattern of injectate following CT‐guided spinal perineural infiltration in the canine thoracolumbar region. Seven fresh canine cadavers were first scanned using multislice CT and then CT‐guided spinal perineural infiltration was performed at 42 sites from T13/L1 to L6/L7. The injectate for each site was a mixture of new methylene blue and iodinated contrast medium. Immediately following CT‐guided injection, cadavers were frozen, cut, and dissected macro‐ and mesoscopically (using a magnifying glass) to identify anatomic structures that were infiltrated. In the majority of sites (64.3%), complete epidural and hypaxial staining of spinal nerve components (including the spinal ganglion, trunk, and ventral branch) was successfully achieved. However, no (11.9%) or unpredictable staining (9.5%) of nervous tissue occurred in some sites despite careful CT guidance and the application of relatively large volumes of injectate. Optimal results were achieved when the needle tip was positioned periforaminally ventral to the cranial contour of the cranial articular process. Findings from this ex vivo study indicated that CT‐guided spinal perineural infiltration is feasible for testing in the canine thoracolumbar region and that successful nerve tissue infiltration would likely occur in the majority of sites. Future in vivo studies are needed to determine the safety and efficacy of this technique.
Development of an Innovative Multisensor Waveguide Probe With Improved Measurement Capabilities
Authors: Lenzi Giulio , Fioravanti Andrea , Ferrara Giovanni , Ferrari Lorenzo
Published: September 2014

Currently, waveguide probes are widely used in several turbomachinery applications ranging from the analysis of flow instabilities to the investigation of thermoacoustic phenomena. There are many advantages to using a waveguide probe. For example, the same sensor can be adopted for different measurement points, thus reducing the total number of sensors or a cheaper sensor with a lower operating temperature capability can be used instead of a more expensive one in case of high temperature applications. Typically, a waveguide probe is made up of a transmitting duct which connects the measurement point with a sensor housing and a damping duct which attenuates the pressure fluctuations reflected by the duct end. If properly designed (i.e., with a very long damping duct), the theoretical response of a waveguide has a monotone trend with an attenuation factor that increases with the frequency and the length of the transmitting duct. Unfortunately, the real geometry of the waveguide components and the type of connection between them have a strong influence on the behavior of the system. Even the smallest discontinuity in the duct connections can lead to a very complex frequency response and a reduced operating range. The geometry of the sensor housing itself is another element which contributes to increasing the differences between the expected and real frequency responses of a waveguide, since its impedance is generally unknown. Previous studies developed by the authors have demonstrated that the replacement of the damping duct with a properly designed termination could be a good solution to increase the waveguide operating range and center it on the frequencies of interest. In detail, the termination could be used to balance the detrimental effects of discontinuities and sensor presence. In this paper, an innovative waveguide system leading to a further increase of the operating range is proposed and tested. The system is based on the measurement of the pressure oscillations propagating in the transmitting duct by means of three sensors placed at different distances from the pressure tap. The pressures measured by the three sensors are then combined and processed to calculate the pressure at the transmitting duct inlet. The arrangement of the sensing elements and the geometry of the termination are designed to minimize the error of this estimation. The frequency response achieved with the proposed arrangement turns out to be very flat over a wide range of frequencies. Thanks to the minor errors in the estimation of pressure modulus and phase, the probe is also suitable for the signal reconstruction both in frequency and time domain.
Test Results and Analytical Predictions for MIL-STD-167 Vibration Testing of a Direct Drive Compressor Supported on Magnetic Bearings
Authors: Hawkins Lawrence A. , Khatri Rasish K. , Nambiar Koman B.
Published: September 2014

External vibration testing was performed on a semihermetic, direct drive compressor on magnetic bearings intended for U.S. Navy Shipboard use. The compressor was placed on a U.S. Navy MIL-STD-167 shaker platform and driven at sinusoidal frequencies from 4 to 33 Hz at graduated displacements equal to a maximum of 1.5 Gs. During the machine design phase, a linear forced response analysis of the coupled rotordynamic system model of the rotor, housing, and magnetic bearings was performed to predict rotor/housing displacements and actuator loads. The results were used to guide bearing sizing and control algorithm design. The measured rotor motion and actuator currents correlated well with predictions at all tested frequencies, amplitudes, and orientations. Analysis methodology, test results, and comparisons are reported here.
Dynamic Response of a Metal and a CMC Turbine Blade During a Controlled Rub Event Using a Segmented Shroud
Authors: Langenbrunner Nisrene , Weaver Matt , Dunn Michael G. , Padova Corso , Barton Jeffery
Published: September 2014

Ceramic matrix composites (CMCs) provide several benefits over metal blades including weight and increased temperature capability, and have the potential for increased engine performance by reduction of the cooling flow bled from the compressor and by allowing engines to run at higher turbine inlet temperatures. These CMC blades must be capable of surviving fatigue (high cycle and low cycle), creep, impact, and any tip rub events due to the engine missions or maneuvers that temporarily close blade tip/shroud clearances. As part of a cooperative research program between GE Aviation and the Ohio State University Gas Turbine Laboratory, OSU GTL, the response of a CMC stage 1 low-pressure turbine blade has been compared with the response of an equivalent metal turbine blade using the OSU GTL large spin-pit facility (LSPF) as the test vehicle. Load cells mounted on the casing wall, strain gages mounted on the airfoils, and other instrumentation are used to assess blade tip rub interactions with a 120-deg sector of a representative turbine stationary casing. The intent of this paper is to present the dynamic response of both the CMC and the metal blades with the turbine disk operating at design speed and with representative incursion rates and depths. Casing wear and blade tip wear are both characterized for several types of rub conditions including a light, medium, and heavy rub at room temperature. For each condition, the rub primary dynamic modes have been evaluated, and the corresponding blade tip loads have been calculated. The preliminary results suggest that a CMC blade has similar abilities to a metal blade during a rub event.
Experiments on an Axial Fan Stage: Time-Resolved Analysis of Rotating Instability Modes
Authors: Pardowitz Benjamin , Tapken Ulf , Neuhaus Lars , Enghardt Lars
Published: September 2014

Rotating instability (RI) occurs at off-design conditions in axial compressors, predominantly in rotor configurations with large tip clearances. Characteristic spectral signatures with side-by-side peaks below the blade passing frequency (BPF) are typically referred to RI located in the clearance region next to the leading edge (LE). Each peak can be assigned to a dominant circumferential mode. RI is the source of the clearance noise (CN) and an indicator for critical operating conditions. Earlier studies at an annular cascade pointed out that RI modes of different circumferential orders occur stochastically distributed in time and independently from each other, which is contradictory to existing explanations of RI. Purpose of the present study is to verify this generally with regard to axial rotor configurations. Experiments were conducted on a laboratory axial fan stage mainly using unsteady pressure measurements in a sensor ring near the rotor LE. A mode decomposition based on cross spectral matrices was used to analyze the spectral and modal RI patterns upstream of the rotor. Additionally, a time-resolved analysis based on a spatial discrete-Fourier-transform (DFT) was applied to clarify the temporal characteristics of the RI modes and their potential interrelations. The results and a comparison with the previous findings on the annular cascade corroborate a new hypothesis about the basic RI mechanism. This hypothesis implies that instability waves of different wavelengths are generated stochastically in a shear layer resulting from a backflow in the tip clearance region.
Cooperative Optimal Synchronization of Networked Uncertain Nonlinear Euler–Lagrange Heterogeneous Multi-Agent Systems With Switching Topologies
Authors: Mehrabian A. R. , Khorasani K.
Published: September 2014

This paper is concerned with design of distributed optimal synchronization control strategies for a class of networked nonlinear heterogeneous multi-agent (HMA) systems whose dynamics are governed by Euler–Lagrange (EL) equations. We employ optimal control techniques to design synchronization (consensus seeking) and set-point regulation controllers for HMA systems through optimization of individual cost functions. We introduce an analytical solution to the optimization problem and show that the developed optimal control laws can manage switchings in the communication network topology. Additionally, we propose two control strategies (namely, adaptive and robust) to modify and generalize the developed optimal control laws in presence of parametric uncertainties in the HMA systems. Simulation results for the attitude synchronization control of a network of eight spacecraft are presented to demonstrate the effectiveness and capabilities of our proposed control algorithms.
Modeling and Synchronous Control of Dual Mechanically Coupled Linear Servo System
Authors: Yao Wu-Sung
Published: September 2014

This paper presents a system modeling technique for a high-speed gantry-type machine tool driven by linear motors. One feed axis of the investigated machine tool is driven by the joint thrust from two parallel linear motors. These two parallel motors are coupled mechanically to form the Y-axis while another standalone motor fixed to a support forms the X-axis. The components in the X-axis, which is treated as the mechanical coupling, are carried by the slides of the Y-axis motors. This configuration is applied to improve the dynamic stiffness of the system and operation speed/acceleration. However, the precise synchronous control of the two parallel and coupled motors would be the major challenge. To overcome this challenge, a multivariable system identification method is developed in this paper. This method is used to construct an accurate system mathematical model for the target coupled system. A synchronous control scheme is then applied to the model obtained using the proposed technique. The performance of the system is experimentally verified with a high-speed S-curve motion profile. The results substantiate the constructed system model and demonstrate the effectiveness of the control scheme.