bluuebunny/crossref_metadata_2025 huggingface dataset:
Plasma ghrelin is positively associated with body fat, liver fat and milk fat content but not with feed intake of dairy cows after parturition
Authors: Börner Sabina , Derno Michael , Hacke Sandra , Kautzsch Ulrike , Schäff Christine , ThanThan Sint , Kuwayama Hideto , Hammon Harald M , Röntgen Monika , Weikard Rosemarie , Kühn Christa , Tuchscherer Armin , Kuhla Björn
Published: November 2012

Ghrelin is a gastrointestinal peptide hormone that is present in blood mostly in a non-posttranslationally modified form, with a minor proportion acylated at Ser3. Both ghrelin forms were initially assigned a role in the control of food intake but there is accumulating evidence for their involvement in fat allocation and utilization. We investigated changes in the ghrelin system in dairy cows, exhibiting differences in body fat mobilization and fatty liver, from late pregnancy to early lactation. Sixteen dairy cows underwent liver biopsy and were retrospectively grouped based on high (H) or low (L) liver fat content post-partum. Both groups had a comparable feed intake in week −6 (before parturition) and week 2 (after parturition). Only before parturition was preprandial total ghrelin concentration higher in L than in H cows and only after parturition was the basal plasma concentration of non-esterified fatty acids higher in H than in L cows. Both before and after parturition, H cows had higher preprandial plasma concentrations of acyl ghrelin, a higher acyl:total ghrelin ratio, lower plasma triacylglyceride concentrations and a lower respiratory quotient compared with L cows. These group differences could not be attributed to an allelic variant of the acyl ghrelin receptor. Rather, the ratio of acyl:total ghrelin correlated with several aspects of fat metabolism and with respiratory quotient but not with feed intake. These results show that endogenous ghrelin forms are associated with fat allocation, fatty liver, and utilization of fat during the periparturient period.
Validation of the Volumetric Measurement of a Simulated Maxillary Alveolar Bone Defect Using Cone-Beam Computed Tomography
Authors: Kasaven C.P. , Ivekovic S. , McIntyre G.T. , Gillgrass T. , Thomson D.A. , Menhinick A. , Mossey P.A.
Published: November 2012

Objective

To determine the accuracy of volumetric measurement of a simulated alveolar bone defect using cone-beam computed tomography (CBCT) scans.

Design

Laboratory-based observational study.

Setting

University dental teaching hospital.

Methods

Scans of a dried skull with an artificially created maxillary bone defect.

Main Outcome Measures

The skull was scanned using an i-CAT CBCT scanner (Imaging Sciences International, Hatfield, PA) at 0.2 mm resolution. The superior and inferior aspects of the void were identified, and the volume was calculated by three-dimensional (3D) computational analysis of the CBCT scan using an algorithm created with MATLAB software (The Mathworks Inc., R2009a, Natick, MA). The skull was then scanned using micro computed tomography (micro-CT) at 0.0934 mm resolution, and the volume of the defect was determined using the Studio Max 2.2 program (Volume Graphics, 2012, Heidelberg, Germany). The process was repeated two additional times, and the volumes were compared using a two-sample t test ( P < .05). To determine the interobserver reproducibility of the identification of the superior and inferior aspects of the defect, the slices chosen to represent these extremities were selected by four separate observers and the data assessed using an F-test ( P < .05).

Results

The interobserver reproducibility of the identification of the superior and inferior boundaries of the defect was good ( P = .18). The volumes computed from the i-CAT CBCT images were 4.11% lower than those computed from the micro-CT images; however, the difference was not statistically significant ( P = .71).

Conclusions

3D volumetric measurement of simulated alveolar bone defects using i-CAT CBCT scans is similar to the volumes determined using micro-CT.
META: A Suite of SAS Programs to Analyze Multienvironment Breeding Trials
Authors: Vargas Mateo , Combs Emily , Alvarado Gregorio , Atlin Gary , Mathews Ky , Crossa Jose
Published: November 2012

Multienvironment trials (METs) enable the evaluation of the same genotypes under a variety of environments and management conditions. We present META (Multi Environment Trial Analysis), a suite of 33 SAS programs that analyze METs with complete or incomplete block designs, with or without adjustment by a covariate. The entire program is run through a graphical user interface. The program can produce boxplots or histograms for all traits, as well as univariate statistics. It also calculates best linear unbiased estimators (BLUEs) and best linear unbiased predictors (BLUPs) for the main response variable and BLUEs for all other traits. For all traits, it calculates variance components by restricted maximum likelihood, least significant difference, coefficient of variation, and broad‐sense heritability using PROC MIXED. The program can analyze each location separately, combine the analysis by management conditions, or combine all locations. The flexibility and simplicity of use of this program makes it a valuable tool for analyzing METs in breeding and agronomy. The META program can be used by any researcher who knows only a few fundamental principles of SAS.
Description of Wheat Straw Relaxation Behavior Based on a Fractional‐Order Constitutive Model
Authors: Chen Longjian , Liao Na , Xing Li , Han Lujia
Published: November 2012

Stress relaxation behavior is an important mechanical property of wheat (Triticum aestivum L.) straw densified biofuel. In this study, 21 cultivars of wheat straw were collected and their lignocellulose components (cellulose, hemicellulose, and lignin) were analyzed. The cellulose, hemicellulose, and lignin contents in these wheat straws ranged from 39.46 to 47.56%, from 30.39 to 35.98%, and from 5.54 to 12.12%, respectively. Stress relaxation tests of wheat straw were performed on an Instron testing machine. It was found that the wheat straw stress relaxation data had a two‐stage characteristic, in which >80% of the total relaxed stress was rapidly released in the initial 10 s, and the stress relaxation was subsequently dominated by a slow stage until an equilibrium stress was reached. Four constitutive models including the Peleg model, the generalized Maxwell model, the Zener model, and the fractional Zener model were proposed to describe this stress relaxation behavior. The results showed that the fractional Zener model gave the best predictions of the wheat straw stress relaxation behavior, followed by the generalized Maxwell model, the Peleg model, and the Zener model. The relationship between stress relaxation behavior and wheat straw lignocellulose components was also further investigated. The fractional derivative coefficient decreased and increased with the increase of cellulose and hemicellulose + lignin contents, respectively. We suggest that the elasticity and viscosity of the wheat straw stress relaxation behavior is closely related with its lignocellulose components.
Quality of zeolit from Vranjska banja deposit according to size classes
Authors: Sekulic Zivko , Dakovic Aleksandra , Kragovic Milan , Markovic Marija , Ivosevic Branislav , Kolonja Bozo
Published: November 2012

This paper presents results of investigations of the quality of the natural
zeolite as well as the quality of particular particle size classes of the
natural zeolite. The aim of the investigations was to determine if the
different classes possess different qualitys. The starting material used in
experiements was the natural zeolite from Zlatokop deposit (Vranjska Banja,
Serbia).. The classes -0.2+0.8 mm; -0.8+0.6 mm; -0.6+0.4 mm; -0.4+0.1 mm were
obtained by wet sieving of the natural zeolite. Grinding processes of the
natural zeolite gave classes -0.3+0.63 mm; -0.63+0 mm; -0,43+0 mm. Chemical
composition , mineralogical XRPD analysis and cation exchange capacity (CEC)
were performed on the starting sample and the obtained particle size classes.
It was determined that all particle size classes possess similar quality. The
highest cation exchange capacity was observed in classes -0,043+0mm (166,5
meq/100g) and -0,063+0mm (158, 8 meq/100g).
Pharmacological inhibition of GSK3 attenuates DNA damage-induced apoptosis via reduction of p53 mitochondrial translocation and Bax oligomerization in neuroblastoma SH-SY5Y CELLS
Authors: Ngok-Ngam Patchara , Watcharasit Piyajit , Thiantanawat Apinya , Satayavivad Jutamaad
Published: November 2012

Glycogen synthase kinase-3 (GSK3) and p53 play crucial roles in the mitochondrial apoptotic pathway and are known to interact in the nucleus. However, it is not known if GSK3 has a regulatory role in the mitochondrial translocation of p53 that participates in apoptotic signaling following DNA damage. In this study, we demonstrated that lithium and SB216763, which are pharmacological inhibitors of GSK3, attenuated p53 accumulation and caspase-3 activation, as shown by PARP cleavage induced by the DNA-damaging agents doxorubicin, etoposide and camptothecin. Furthermore, each of these agents induced translocation of p53 to the mitochondria and activated the mitochondrial pathway of apoptosis, as evidenced by the release of cytochrome C from the mitochondria. Both mitochondrial translocation of p53 and mitochondrial release of cytochrome C were attenuated by inhibition of GSK3, indicating that GSK3 promotes the DNA damage-induced mitochondrial translocation of p53 and the mitochondrial apoptosis pathway. Interestingly, the regulation of p53 mitochondrial translocation by GSK3 was only evident with wild-type p53, not with mutated p53. GSK3 inhibition also reduced the phosphorylation of wild-type p53 at serine 33, which is induced by doxorubicin, etoposide and camptothecin in the mitochondria. Moreover, inhibition of GSK3 reduced etoposide-induced association of p53 with Bcl2 and Bax oligomerization. These findings show that GSK3 promotes the mitochondrial translocation of p53, enabling its interaction with Bcl2 to allow Bax oligomerization and the subsequent release of cytochrome C. This leads to caspase activation in the mitochondrial pathway of intrinsic apoptotic signaling.
Synthesis and keto-enol tautomerism of ethyl 4-oxo-3,4-dihydro-1H-pyrano[3,4-b]quinoline-3-carboxylate
Authors: Chang Ming-Qin , Gao Feng , Li Yang , Gao Wen-Tao
Published: November 2012

An efficient method has been developed for the synthesis of a novel β-keto ester-containing pyranoquinoline compound, i.e., ethyl 4-oxo-3,4-dihydro-1H-pyrano[3,4-b]quinoline-3-carboxylate. The method entails a two-step synthesis. The first step involves the Williamson-type reaction of ethyl 2-bromomethyl-3-quinoline-3-carboxylate with ethyl hydroxyacetate in anhydrous benzene to afford the intermediate ethyl 2-[(2-ethoxy-2-oxoethoxy)methyl]quinoline-3-carboxylate. The second step includes the Dieckmann condensation reaction of the resulting intermediate in the presence of sodium ethoxide in anhydrous toluene to afford the desired pyranoquinoline containing β-keto ester moiety. Keto-enol tautomerism of the compound thus obtained was investigated by spectroscopic methods.
Prediction of anti-tuberculosis activity of 3-phenyl-2H-1,3-benzoxazine-2,4(3H)-dione derivatives
Authors: Nemeček Peter , Mocák Ján , Lehotay Jozef , Waisser Karel
Published: November 2012

Correlation analysis and, in particular, artificial neural networks (ANN) were used to predict the anti-mycobacterial activity of substituted 3-phenyl-2H-1,3-benzoxazine-2,4(3H)-diones (PBODs) by quantitative structure — activity relationship (QSAR) calculations. Initially, sixty-four derivatives were synthesised and biologically tested; ten further derivatives were proposed for future synthesis on the basis of the prediction results. The biological activity was originally expressed by minimum inhibitory concentration (MIC) against Mycobacterium tuberculosis; however, its transformed pMIC form was found to be more informative. Theoretical molecular descriptors of several types were selected to establish a primary drug model of the species which was expected to exhibit a substantial anti-mycobacterial effect. Lipophilicity and solubility indices, several basic molecular properties, quantum chemistry quantities as well as 1H and 13C NMR chemical shifts, were employed as the descriptors, enabling a very successful prediction of the pMIC values. The utilisation of in silico variables and simulated NMR data is highly advantageous in the first phase of the drug design, as they permit prediction of the compounds with a high expected activity, minimising the risk of synthesising less active species. The MIC values predicted at less than 4 μmol L−1 for six of the ten compounds suggested for further synthesis are better than the best value for the original set of compounds.
Which Exercises Target the Gluteal Muscles While Minimizing Activation of the Tensor Fascia Lata? Electromyographic Assessment Using Fine-Wire Electrodes
Authors: Selkowitz David M. , Beneck George J. , Powers Christopher M.
Published: November 2012

Study Design

Controlled laboratory study, repeated-measures design.

Objectives

To compare hip abductor muscle activity during selected exercises using fine-wire electromyography, and to determine which exercises are best for activating the gluteus medius and the superior portion of the gluteus maximus, while minimizing activity of the tensor fascia lata (TFL).

Background

Abnormal hip kinematics (ie, excessive hip adduction and internal rotation) has been linked to certain musculoskeletal disorders. The TFL is a hip abductor, but it also internally rotates the hip. As such, it may be important to select exercises that activate the gluteal hip abductors while minimizing activation of the TFL.

Methods

Twenty healthy persons participated. Electromyographic signals were obtained from the gluteus medius, superior gluteus maximus, and TFL muscles using fine-wire electrodes as subjects performed 11 different exercises. Normalized electromyographic signal amplitude was compared among muscles for each exercise, using multiple 1-way repeated-measures analyses of variance. A descriptive gluteal-to-TFL muscle activation index was used to identify preferred exercises for recruiting the gluteal muscles while minimizing TFL activity.

Results

Both gluteal muscles were significantly (P<.05) more active than the TFL in unilateral and bilateral bridging, quadruped hip extension (knee flexed and extending), the clam, sidestepping, and squatting. The gluteal-to-TFL muscle activation index ranged from 18 to 115 and was highest for the clam (115), sidestep (64), unilateral bridge (59), and both quadruped exercises (50).

Conclusion

If the goal of rehabilitation is to preferentially activate the gluteal muscles while minimizing TFL activation, then the clam, sidestep, unilateral bridge, and both quadruped hip extension exercises would appear to be the most appropriate. J Orthop Sports Phys Ther 2013;43(2):54–64. Epub 16 November 2012. doi:10.2519/jospt.2013.4116
Ways of Experiencing Participation and Factors Affecting the Activity Level After Nonreconstructed Anterior Cruciate Ligament Injury: A Qualitative Study
Authors: Österberg Annika , Kvist Joanna , Dahlgren Madeleine Abrandt
Published: November 2012

Study Design

Phenomenographic, cross-sectional.

Objectives

To describe ways of experiencing participation in activities of individuals with a nonreconstructed anterior cruciate ligament injury and to describe the emotional aspects related to participation. Further, the objective was to explore factors affecting the activity level.

Background

The importance of assessing different factors (knee status, muscle performance, psychological factors, performance-based tests, and subjective rating of knee function) after an anterior cruciate ligament injury has been emphasized. However, the results of these assessments do not answer the question of how the individuals themselves experience their participation in activities.

Methods

Semi-structured interviews were conducted with 19 strategically selected informants (age range, 18–43 years) who had sustained an anterior cruciate ligament injury 18 to 67 months previously. A phenomenographic approach, which describes individuals' ways of experiencing a phenomenon, was used.

Results

Five qualitatively different categories were identified: (A) unconditioned participation, (B) participation as conditioned by risk appraisal, (C) participation as conditioned by experienced control of the knee, (D) participation as conditioned by experienced knee impairment, and (E) participation as conditioned by neglecting the knee injury. Within each category, 5 interrelated aspects were discerned: focus, level of performance, activities, strategies, and feelings. Categories A, C, and E reflected experiences of full participation, whereas categories B and D reflected experiences of modified participation. There were mostly positive feelings regarding participation. Negative feelings were expressed in category D. Factors affecting the activity level were grouped according to the framework of the International Classification of Functioning, Disability and Health and described as facilitating or hindering the activity level. Facilitating factors included regaining and maintaining physical function, regaining confidence in knee function, and learning/relearning movement patterns. Hindering factors included fear of injury/reinjury, uncontrollable giving way, and loss of motivation.

Conclusion

With different strategies, most of the informants achieved a satisfactory activity level, despite impairments and decreased activity level. Both physical and psychological factors were described to affect the activity level, as well as time since injury. J Orthop Sports Phys Ther 2013;43(3):172–183. Epub 16 November 2012. doi:10.2519/jospt.2013.4278
Conscious Correction of Scapular Orientation in Overhead Athletes Performing Selected Shoulder Rehabilitation Exercises: The Effect on Trapezius Muscle Activation Measured by Surface Electromyography
Authors: De Mey Kristof , Danneels Lieven , Cagnie Barbara , Huyghe Lies , Seyns Elien , Cools Ann M.
Published: November 2012

Study Design

Controlled laboratory study.

Objectives

To assess the effect of conscious correction of scapular orientation on the activation of the 3 sections of the trapezius muscle during shoulder exercises in overhead athletes with scapular dyskinesis.

Background

Previous research has led to the recommendation of 4 exercises for training of the trapezius muscle: prone extension, sidelying external rotation, sidelying forward flexion, and prone horizontal abduction with external rotation. However, the extent to which conscious correction of scapular orientation impacts trapezius muscle activation levels during these exercises is unknown.

Methods

Absolute (upper trapezius [UT], middle trapezius [MT], lower trapezius [LT]) and relative (UT/MT and UT/LT) muscle activation levels were determined with surface electromyography in 30 asymptomatic overhead athletes with scapular dyskinesis, during 4 selected exercises performed with and without conscious correction of scapular orientation. Repeated-measures analyses of variance were used to determine if a voluntary scapular orientation correction strategy influenced the activation levels of the different sections of the trapezius during each exercise.

Results

With conscious correction of scapular orientation, activation levels of the 3 sections of the trapezius muscle significantly increased during prone extension (mean ± SD difference: UT, 5.9% ± 8.6% maximal voluntary isometric contraction [MVIC]; MT, 13.8% ± 11.0% MVIC; LT, 9.8% ± 10.8% MVIC; P<.05) and sidelying external rotation (UT, 2.2% ± 4.4% MVIC; MT, 6.7% ± 10.6% MVIC; LT, 13.3% ± 24.4% MVIC; P<.05). There was no difference between conditions for sidelying forward flexion and prone horizontal abduction with external rotation. The UT/MT and UT/LT ratios were similar between conditions for all 4 exercises.

Conclusion

Conscious correction of scapular orientation during the prone extension and sidelying external rotation exercises can be used to increase the activation level in the 3 sections of the trapezius in overhead athletes with scapular dyskinesis. Although lack of kinematic data limits the interpretation of the results, this study suggests that conscious correction of scapular orientation can be performed without altering the favorable UT/MT and UT/LT ratios that have been previously reported for these exercises. J Orthop Sports Phys Ther 2013;43(1):3–10. Epub 16 November 2012. doi:10.2519/jospt.2013.4283
Comparison of the Sonographic Features of the Abdominal Wall Muscles and Connective Tissues in Individuals With and Without Lumbopelvic Pain
Authors: Whittaker Jackie L. , Warner Martin B. , Stokes Maria
Published: November 2012

Study Design

Cross-sectional, case-control study.

Objectives

To measure and compare the resting thickness of the 4 abdominal wall muscles, their associated perimuscular connective tissue (PMCT), and interrecti distance (IRD) in persons with and without lumbopelvic pain (LPP), using ultrasound imaging.

Background

The muscles and PMCT of the abdominal wall assist in controlling the spine. Functional deficits of the abdominal wall muscles have been detected in populations with LPP. Investigations of the abdominal wall in those with LPP are primarily concerned with muscle, most commonly the transversus abdominis (TrA) and internal oblique (IO). Because the abdominal wall functions as a unit, all 4 abdominal muscles and their associated connective tissues should be considered concurrently.

Methods

B-mode ultrasound imaging was used to measure the resting thickness of the rectus abdominis (RA), external oblique, IO, and TrA muscles; the PMCT planes; and IRD in 50 male and female subjects, 25 with and 25 without LPP (mean ± SD age, 36.3 ± 9.4 and 46.6 ± 8.0 years, respectively). Univariate correlation analysis was used to identify covariates. Analyses of covariance (ANCOVAs) and the Kruskal-Wallis test (IRD) were used to compare cohorts (α = .05).

Results

The LPP cohort had less total abdominal muscle thickness (LPP mean ± SD, 18.9 ± 3.0 mm; control, 20.3 ± 3.0 mm; ANCOVA adjusted for body mass index, P = .03), thicker PMCT (LPP, 5.5 ± 0.2 mm; control, 4.3 ± 0.2 mm; ANCOVA adjusted for body mass index, P = .007), and wider IRD (LPP, 11.5 ± 2.0 mm; control, 8.4 ± 1.8 mm; Kruskal-Wallis, P = .005). Analysis of individual muscle thickness revealed no difference in the external oblique, IO, and TrA, but a thinner RA in the LPP cohort (LPP mean ± SD, 7.8 ± 1.5 mm; control, 9.1 ± 1.2 mm; ANCOVA adjusted for body mass index, P<.001).

Conclusion

To our knowledge, this is the first study to investigate the morphological characteristics of all 4 abdominal muscles and PMCT in individuals with LPP. The results suggest that there may be altered loading of the PMCT and linea alba secondary to an altered motor control strategy involving a reduced contribution of the RA. Further, the change in RA and connective tissue morphology may be more evident than changes in external oblique, IO, and TrA thickness in persons with LPP. The causes and functional implications of these changes warrant further investigation, as does the role of the RA muscle in the development and persistence of LPP. J Orthop Sports Phys Ther 2013;43(1):11–19. Epub 16 November 2012. doi:10.2519/jospt.2013.4450
Cognitive Treatment of Illness Perceptions in Patients With Chronic Low Back Pain: A Randomized Controlled Trial
Authors: Siemonsma Petra C. , Stuive Ilse , Roorda Leo D. , Vollebregt Joke A. , Walker Marion F. , Lankhorst Gustaaf J. , Lettinga Ant T.
Published: November 2012

Background

Illness perceptions have been shown to predict patient activities. Therefore, studies of the effectiveness of a targeted illness-perception intervention on chronic nonspecific low back pain (CLBP) are needed.

Objective

The purpose of this study was to compare the effectiveness of treatment of illness perceptions against a waiting list for patients with CLBP.

Design

This was a prospectively registered randomized controlled trial with an assessor blinded for group allocation.

Setting

The study was conducted in an outpatient rehabilitation clinic.

Participants

The participants were 156 patients (18–70 years of age) with CLBP (>3 months).

Intervention

Patients were randomly assigned to either a treatment group or to a waiting list (control) group. Trained physical therapists and occupational therapists delivered 10 to 14 one-hour treatment sessions according to the treatment protocol.

Measurements

The primary outcome measure was change in patient-relevant physical activities (Patient-Specific Complaints questionnaire). The secondary outcome measures were changes in illness perceptions (Illness Perceptions Questionnaire) and generic physical activity level (Quebec Back Pain Disability Scale). Measurements were taken at baseline (0 weeks) and after treatment (18 weeks).

Results

A baseline-adjusted analysis of covariance showed that there were statistically significant differences between intervention and control groups at 18 weeks for the change in patient-relevant physical activities. This was a clinically relevant change (19.1 mm) for the intervention group. Statistically significant differences were found for the majority of illness perception scales. There were no significant differences in generic physical activity levels.

Limitations

Longer-term effectiveness was not studied.

Conclusions

This first trial evaluating cognitive treatment of illness perceptions concerning CLBP showed statistically significant and clinically relevant improvements in patient-relevant physical activities at 18 weeks.
The Big-Fish-Little-Pond Effect and a National Policy of Within-School Ability Streaming
Authors: Liem Gregory Arief D. , Marsh Herbert W. , Martin Andrew J. , McInerney Dennis M. , Yeung Alexander S.
Published: November 2012

The big-fish-little-pond effect (BFLPE) was evaluated with 4,461 seventh to ninth graders in Singapore where a national policy of ability streaming is implemented. Consistent with the BFLPE, when prior achievement was controlled, students in the high-ability stream had lower English and mathematics self-concepts (ESCs and MSCs) and those in the lower-ability stream had higher ESCs and MSCs. Consistent with the local-dominance effect, the effect of stream-average achievement on ESCs and MSCs was more negative than—and completely subsumed—the negative effect of school-average achievement. However, stream-average achievement was stronger than, or as strong as, the more local class-average achievement. Taken together, findings highlight the potential interplay of a local dominance effect with variability and/or salience of target comparisons in academic self-concept formations.
Dual-Mode and New Diesel Locomotive Developments
Authors: Vitins Janis
Published: November 2012

The integration of electric and diesel traction into a single rail vehicle is technically challenging because of weight and space restrictions, particularly for AC catenary power. Through the combination of recent developments in power converter technology, diesel engine design, and mechanical lightweight structures, dual-mode locomotives are now feasible for railroad applications. Apart from the different modes of traction, such locomotives must also fulfill the latest vehicle standards in regard to safety, environmental impact, and interoperability. A key component is the DC link of the traction converter, which interfaces to electric and diesel power supply systems. In addition, batteries, supercaps, or both can be interfaced to this DC link. All electric power flow is bidirectional and thus permits many possibilities for energy savings and reductions in exhaust emissions. The performance of a dual-mode locomotive is greatly enhanced by the latest high-speed diesel engines developed for off-road and industrial applications. Not only do the engines provide high diesel power at low weight, but they also meet the new Tier 3 and upcoming Tier 4 exhaust emission standards. For maximum vehicle performance in both modes, the car body and truck must be lightweight. A monocoque car body and fabricated truck are the obvious solutions, as used on the dual-powered ALP-45DP and the European TRAXX AC3, which is an electric locomotive with a diesel engine for operation on nonelectrified sidings and terminals. The above technologies also lend themselves to new diesel–electric locomotives, by yielding a high vehicle performance at low axle loads, as required for passenger services at 125 mph.
Portable Emission Measurement System for Emissions of Passenger Rail Locomotives
Authors: Frey H. Christopher , Choi Hyung-Wook , Kim Kangwook
Published: November 2012

The purpose of this study was to demonstrate a method for measuring passenger railroad locomotive emissions with the use of a portable emission measurement system (PEMS) based on rail yard load tests of three locomotives, including one GP40 and two F59PHIs. These locomotives have mechanically governed diesel prime mover engines (PMEs) with an approximately 3,000-hp output. Each locomotive has a head end power (HEP) engine that produces approximately 600 hp for generating electricity used in the passenger cars. The engine measurements were based on ultralow sulfur diesel fuel. Each engine was instrumented to measure manifold absolute pressure, engine revolutions per minute, intake air temperature, and exhaust concentrations of selected gases and particles. These data were used to quantify exhaust and fuel flow. The exhaust concentrations of nitric oxide, carbon monoxide (CO), carbon dioxide, hydrocarbons, and particulate matter were measured. The PMEs are operated at each of many throttle notch settings. For the HEP engines, three electrical loads were applied on the basis of power usage for one, two, and four passenger cars, respectively. More than 97% of the raw data survived a multistep quality assurance process. The data obtained from the PEMS for the main engines were found to be comparable on a fuel basis to data reported by others, particularly for oxides of nitrogen and CO. The key results from this work are the establishment of a simplified methodology for future tests and the development of baseline data.
Source of Ballast Fouling and Influence Considerations for Condition Assessment Criteria
Authors: Sussmann Ted R. , Ruel Mario , Chrismer Steven M.
Published: November 2012

Railway ballast is a critical element in the railway track support structure. The ballast is often overlooked when inspection tools are developed for track. When ballast is not functioning correctly, the strength of the track structure may be inadequate and thus compromise track stability. Track stability–related failures vary from rapid deterioration with little warning to slow and progressive deterioration with often predictable required maintenance. Ballast-related deterioration is progressive and usually provides visual evidence to warn maintenance personnel of needed rehabilitation. However, the blocked drainage that develops with fouled ballast can result in a saturated roadbed that is not stable and could rapidly deteriorate to an unsafe condition with little warning. Although massive failures are rare, if a side hill fill or embankment deteriorates to the point of becoming susceptible to massive failure, then the challenge becomes evaluation. More detailed knowledge of the track support condition will be needed for a thorough evaluation than can be provided by current track inspections, except for costly detailed visual inspections. The current standard of practice for ballast inspection and maintenance can be improved to reduce the risk of sudden failure. Much of the required technology, knowledge, and resources is already available and being utilized under the current system. A more precise evaluation of ballast condition is essential to identify thresholds related to unsafe track support conditions and to support effective maintenance plans.
Ground-Penetrating Radar Data to Develop Wavelet Technique for Quantifying Railroad Ballast–Fouling Conditions
Authors: Shangguan Pengcheng , Al-Qadi Imad L. , Leng Zhen
Published: November 2012

Ballast fouling is detrimental to railroad track functions. Ground-penetrating radar (GPR), a nondestructive testing tool, has been used to assess ballast-fouling conditions. However, processing the extensive amount of data to quantify ballast conditions is challenging. Although several approaches have been developed, each of them has certain disadvantages, such as being unable to detect fouling without a clear interface between clean and fouled ballast and being user dependent. To overcome these disadvantages, a new approach based on wavelet transform was investigated. Laboratory tests were conducted to collect GPR data on ballast with controlled fouling levels. The data were processed by choosing the proper mother wavelet, selecting appropriate wavelet decomposition coefficients, and de-noising the signal. Standard deviation (SD) values of the processed wavelet detail coefficients were calculated. On the basis of the scattering theory, the resulting SD value, which represents the scattering intensity of the signal, is an indication of the fouling level. The laboratory results clearly show that the SD value decreases as the fouling level increases. The effectiveness of the proposed approach was then validated by field data from the Orin subdivision in Wyoming. By a comparison of in situ ground truth data and GPR measurements, the wavelet transform was proved to be an effective approach to quantifying ballast-fouling conditions. This approach allows for fouling assessment without the presence of a clear interface between clean and fouled ballast and reduces user dependency. In addition, the new approach is capable of processing GPR data automatically and continuously and provides the entire fouling profile along the tracks.
Asset Condition Assessment at Regional Transportation Authority in Chicago, Illinois
Authors: Gallucci Grace , Goodworth John , Allen John G.
Published: November 2012

Traditionally, transit systems managed their assets on an as-needed basis, but the urgency of overcoming deferred maintenance in the 1980s brought about an interest in capital programming to systematize the modernization of the physical plant better. Since the early 21st century, efforts to plan for capital maintenance needs have taken the form of the more ongoing process of asset management. Responding to several critical needs in the transit infrastructure of the Chicago, Illinois, area since the late 1980s, the Regional Transportation Authority (RTA) commissioned an asset condition assessment for transit in northeastern Illinois. The resulting study, released in 2010, is an industry leader in taking stock of an entire region's transit capital assets. The study establishes an estimated replacement cost for the system and 10-year state-of-good-repair needs. RTA intends to make an annual revision of this assessment into an ongoing process and is using the data as part of its overall performance measurement process. A decision tool is being developed in cooperation with other transit systems to help prioritize investments on the basis of the condition, importance, and impact of different assets.
Methodological Framework for Analyzing Ability of Freight Rail Customers to Forecast Short-Term Volumes Accurately
Authors: Moll Stephan , Weidmann Ulrich , Nash Andrew
Published: November 2012

The freight transport business is extremely challenging for railways because transport by truck has intrinsic advantages in flexibility and quality. Providing freight customers with flexible scheduling is particularly difficult because optimizing an interconnected rail operating plan is more difficult than arranging for shipment by truck. In this environment it would be helpful if shippers could provide railways with accurate demand forecasts. However, the ability to forecast rail freight transport differs strongly by shipper and commodity type. The goal of this research is to develop a methodological framework to understand better the characteristics that influence the ability of freight shippers to prepare accurate forecasts of rail demand. This information will help railways increase productivity by improving their ability to develop optimized schedules. It will help railways decide when to rely on shipper forecasts and provide a benchmark for identifying shippers that can provide accurate forecasts. The paper describes the methodological framework and presents results from a case study application to illustrate the practical applicability of the proposed framework.
Value for Railway Capacity
Authors: Sameni Melody Khadem , Preston John M.
Published: November 2012

Growth in rail traffic has not been matched by increases in railway infrastructure. Given this capacity challenge and the current restrictions on public spending, the allocation and the utilization of existing railway capacity are more important than ever. Great Britain has had the greatest growth in rail passenger kilometers of European countries since 1996. However, costs are higher and efficiency is lower than European best practice. This paper provides an innovative methodology for assessing the efficiency of passenger operators in capacity utilization. Data envelopment analysis (DEA) is used to analyze the efficiency of operators in transforming inputs of allocated capacity of infrastructure and franchise payments into valuable passenger service outputs while avoiding delays. By addressing operational and economic aspects of capacity utilization simultaneously, the paper deviates from existing DEA work on the economic efficiency of railways by considering a new combination of input–output that also incorporates quality of service. The constant and variable returns to scale models are applied to the case study of franchised passenger operators in Great Britain. The follow-up Tobit regression model shows positive correlation between serving London and the efficiency scores. There is negative correlation between offering regional services (average length of journeys less than 40 mi) and the efficiency scores. The overall study and the results can provide helpful insights for railway authorities into the tactical and strategic planning of railways needed to increase efficiency.
Development and Assessment of Taxonomy for Performance-Shaping Factors for Railway Operations
Authors: Kyriakidis Miltos , Majumdar Arnab , Grote Gudela , Ochieng Washington Y.
Published: November 2012

Human performance is a significant contributor to railway incidents and accidents. The literature shows that train drivers, signalers, and controllers most affect network safety. Several studies have been conducted in the field of human factors and human performance in the railway domain to investigate operators' influence on the railway system. However, most studies are based on previous studies from other domains, which are not well suited and can be difficult to apply reliably to railway-specific operations. In light of the current limitations, this paper proposes a new approach referred to as the human performance railway operational index (HuPeROI). HuPeROI aims not only to estimate the human error probability for railway operations but also to propose mitigation strategies to minimize phenomena such as operators' degraded performance. HuPeROI is based on a performance-shaping factors taxonomy designed for the rail industry, referred to as the railway performance-shaping factor (R-PSF) taxonomy. The R-PSF taxonomy was developed on the basis of an extensive literature review of the field of human factors and subsequently validated against the findings derived from the analysis of 179 railway accident and incident reports, as well as targeted interviews with subject matter experts. This paper presents the taxonomy and the underlying theory, as well as the results of the validation process based on the analysis of 179 reports and the assessment of R-PSFs for four different scenarios based on a subject matter expert elicitation process. The R-PSF taxonomy and HuPeROI should enable researchers to address and deal with the effect of degraded performance of railway operators.
Inferring Infection-Spreading Links in an Air Traffic Network
Authors: Gardner Lauren M. , Fajardo David , Waller S. Travis
Published: November 2012

The objective of this paper is to present a network-based optimization method for identifying links in an air traffic network responsible for carrying infected passengers into previously unexposed regions. The required data include individual infection reports (i.e., when the disease was first reported in a region), travel pattern data, and other geographic properties. The network structure is defined by nodes and links, which represent regions (cities, states, countries) and travel routes, respectively. The proposed methodology is novel in its attempt to replicate an outbreak pattern atop a transportation network by exploiting regional infection data. The problem parallels a related problem in phylodynamics, which uses genetic sequencing data to reconstruct the most likely spatiotemporal path of infection.
Characterization of Surface and Aloft Winds for Advanced Parallel Runway Operations
Authors: Audenaerd Laurence
Published: November 2012

The increase in demand for air travel throughput has resulted in an effort to identify novel techniques for improving efficiency. One such effort targets the barrier imposed by wake turbulence separation standards—reducing interaircraft spacing during radar operations. Recently, concepts have focused on exploiting the effects of wake transport under wind fields by developing wind-dependent procedures that mitigate wake hazards during favorable wind conditions. However, the challenge with regard to computing benefits during conditional time epochs requires methodology designed for a niche modeling area that even sophisticated airport capacity simulation models lack. This work attempts to augment the capacity computation by presenting a characterization of the favorable crosswind availability across a range of thresholds and aloft monitoring heights based on Rapid Update Cycle and aviation system performance measure weather data. The focus is on presenting a generalization of wind behavior and on providing insight into the effects of the wind on the applicability of wind-dependent wake-based procedures. Data for nine major U.S. airports currently operating closely spaced parallel runways are analyzed.
Mind the Gap
Authors: Kisia Duncan
Published: November 2012

Airport employees often account for a substantial share of daily airport access trips, yet current planning for airport landside access in the United States focuses almost exclusively on identifying and addressing the needs of air passengers. Airport worker travel patterns are normally studied by using the standard journey-to-work components of travel demand models and generally do not capture the unique factors affecting this group's commuting behavior. The Port Authority Trans-Hudson (PATH) commissioned a preliminary study evaluating the economic feasibility of extending PATH rail service to Newark Liberty International Airport, New Jersey. An empirical analysis of survey data collected during this effort suggests that the traditional travel demand model approaches to studying airport worker commuting patterns often mischaracterize the travel patterns and attitudes of a large airport access market segment. This research finds that the omission of airport worker input in the planning process is likely to result in the overestimation of public transit demand and may only exacerbate the optimism bias that has typically affected rail transportation investments in the United States.
Landing Fees in Portuguese Airports
Authors: Morgado Frederico , Macário Rosário
Published: November 2012

How the real costs of maintenance and renewal of runways and related taxiways and aprons can be assigned to users on the basis of aircraft classification number (ACN) is analyzed, following previous work by Hogan and Starkie, who compared their results with actual fees charged in Dublin, Ireland. This paper furthers the consideration of off-peak charges per marginal induced damage costs with data from Lisbon, Porto, and Faro, Portugal, in 2009. A fairness factor is defined to assess what each aircraft type pays versus the damage it inflicts on pavements. Huge relative unfairness is highlighted under the current maximum takeoff weight fee scheme among various aircraft types at the three airports. A linear relationship between marginal cost per €1,000,000 and induced damage by each aircraft type is derived. Finally, a new and fair landing fee scheme is proposed that is based on ACN-related marginal costs. Simplifications and assumptions with regard to full cost recovery with marginal cost pricing are considered. The conclusion is that a strong case can be made for application to large and medium aircraft, but perhaps not to small aircraft.
Trade Space Analysis of Surface Alternatives for Short-Haul Passenger Air Travel
Authors: Audenaerd Laurence , Boyce David , Schofer Joseph
Published: November 2012

Intercity passenger transportation is a time- and energy-intensive activity. Despite a growing social consciousness of “green” alternatives, travelers continue to choose routes and modes primarily on the basis of travel time and cost. Although long-distance trips of more than 500 mi (800 km) are dominated by air travel, short- and medium-haul trips compete with surface modes when total travel time and cost are compared. Because of hub-and-spoke air transport networks, short-haul air travel is bundled with long-haul itineraries. At congested hubs, passengers can experience lengthy transfer times, which can provide an opportunity for competitive mode substitution. This paper focuses on the travel time trade-offs between air and surface modes and the implications for short-haul air trip substitutability through an analysis of 17 short-haul markets transferring through O'Hare International Airport, Chicago, Illinois. The results suggest that when transfer times are considered, mode substitutability is not directly associated with distance and that there are competitive opportunities for ground modes that may offer cost, energy, and environmental benefits.
Postshunting corpus callosum swelling with depiction on tractography
Authors: Ginat Daniel T. , Prabhu Sanjay P. , Madsen Joseph R.
Published: November 2012

Alterations in the appearance of the corpus callosum occasionally occur following successful ventricular decompression in patients with chronic hydrocephalus. There are certain features on imaging that suggest the diagnosis of what the authors propose be termed “postshunting corpus callosum swelling,” including diffuse high T2 signal predominantly affecting the body of the corpus callosum, with transverse orientation along the crossing white matter tracts and scalloping along the posterior margin of the structure. In this report, the authors demonstrate preservation of the corpus callosum white matter fiber tracts by using diffusion tensor imaging with tractography.