bluuebunny/crossref_metadata_2025_split huggingface dataset:
Discrimination of stable isotopes in fin whale tissues and application to diet assessment in cetaceans
Authors: Borrell A. , Abad‐Oliva N. , Gómez‐Campos E. , Giménez J. , Aguilar A. 
Published: June 2012

RATIONALEIn stable isotope research, the use of accurate, species‐specific diet‐tissue discrimination factors (i.e., Δ13C and Δ15N) is central to the estimation of trophic position relative to primary consumers and to the identification of the dietary sources of an individual. Previous research suggested that the diet of fin whales from the waters off northwestern Spain is overwhelmingly based on krill, thus permitting reliable calculation of discrimination values in this wild population.METHODSAfter confirming that the stable isotope ratios (δ13C and δ15N values) in muscle from 65 aged fin whales remained constant through age classes (4–65 years), the signatures were determined in muscle, bone protein, skin, liver, kidney, baleen plates and brain, as well as food (krill), from a subset of individuals to calculate discrimination factors. Signatures were determined by means of elemental analysis isotope ratio mass spectrometry (EA‐IRMS) using a ThermoFinnigan Flash 1112.RESULTSThe isotopic values remained constant regardless of age. The mean Δ15N values between krill and whale tissues ranged from 2.04 in bone protein to 4.27‰ in brain, and those of Δ13C ranged from 1.28 in skin to 3.11‰ in bone protein. This variation was consistent with that found in other groups of mammals, and is attributed to variation in tissue composition and physiology.CONCLUSIONSBecause discrimination factors are relatively constant between taxonomically close species, the results here obtained may be reliably extrapolated to other cetaceans to improve dietary reconstructions. The skin discrimination factors are of particular relevance to monitoring diet through biopsies or other non‐destructive sampling methods. The large difference in bone protein discrimination factors from those of other tissues should be taken into consideration when bone collagen is used to determine trophic level or to assess diet in paleodietary isotopic reconstructions. Copyright © 2012 John Wiley & Sons, Ltd.
Flocking under hierarchical leadership with a free‐will leader
Authors: Dong Jiu‐Gang 
Published: June 2012

SUMMARYRecently, a model for flocking was introduced by Cucker and Smale together with a proof of convergence. This proof established unconditional convergence to flocking (i.e., to a common velocity), provided the interaction between agents was strong enough and conditional convergence otherwise. The strength of the interaction is measured by a parameter β, and the critical value at which unconditional convergence stops holding is β = 1 ∕ 2. This model was extended by Shen to allow for a hierarchical leadership structure among the agents, and similar convergence results were proved. But, for discrete time, convergence result was only for the flock with an overall leader moving with a constant velocity. In this note, we establish convergence result for the flock with a free‐will leader. Copyright © 2012 John Wiley & Sons, Ltd.
crimsonHex: a learning objects repository for programming exercises
Authors: Queirós Ricardo , Leal José Paulo 
Published: June 2012

SUMMARYA repository of learning objects is a system that stores electronic resources in a technology‐mediated learning process. The need for this kind of repository is growing as more educators become eager to use digital educational contents and more of it becomes available. The sharing and use of these resources relies on the use of content and communication standards as a means to describe and exchange educational resources, commonly known as learning objects. This paper presents the design and implementation of a service‐oriented repository of learning objects called crimsonHex. This repository supports new definitions of learning objects for specialized domains and we illustrate this feature with the definition of programming exercises as learning objects and its validation by the repository. The repository is also fully compliant with existing communication standards and we propose extensions by adding new functions, formalizing message interchange and providing a REST interface. To validate the interoperability features of the repository, we developed a repository plug‐in for Moodle that is expected to be included in the next release of this popular learning management system. Copyright © 2012 John Wiley & Sons, Ltd.
Stable Long-Term Blood Formation by Stem Cells in Murine Steady-State Hematopoiesis
Authors: Zavidij Oksana , Ball Claudia R. , Herbst Friederike , Oppel Felix , Fessler Sylvia , Schmidt Manfred , von Kalle Christof , Glimm Hanno 
Published: June 2012

Abstract
Hematopoietic stem cells (HSCs) generate all mature blood cells during the whole lifespan of an individual. However, the clonal contribution of individual HSC and progenitor cells in steady-state hematopoiesis is poorly understood. To investigate the activity of HSCs under steady-state conditions, murine HSC and progenitor cells were genetically marked in vivo by integrating lentiviral vectors (LVs) encoding green fluorescent protein (GFP). Hematopoietic contribution of individual marked clones was monitored by determination of lentiviral integration sites using highly sensitive linear amplification-mediated-polymerase chain reaction. A remarkably stable small proportion of hematopoietic cells expressed GFP in LV-injected animals for up to 24 months, indicating stable marking of murine steady-state hematopoiesis. Analysis of the lentiviral integration sites revealed that multiple hematopoietic clones with both myeloid and lymphoid differentiation potential contributed to long-term hematopoiesis. In contrast to intrafemoral vector injection, intravenous administration of LV preferentially targeted short-lived progenitor cells. Myelosuppressive treatment of mice prior to LV-injection did not affect the marking efficiency. Our study represents the first continuous analysis of clonal behavior of genetically marked hematopoietic cells in an unmanipulated system, providing evidence that multiple clones are simultaneously active in murine steady-state hematopoiesis.
Genotype by environment interaction effects on fibre components in potato (Solanum tuberosum L.)
Authors: Bach Stephanie , Yada Rickey Y. , Bizimungu Benoit , Sullivan J. Alan 
Published: June 2012

AbstractIncreasing awareness of heart health and disease prevention has led consumers to more proactive grocery food choices. Fibre and its associated health benefits remains an important area of research given the current interest in food, nutrition, and health. To position the potato as a good source of fibre, breeding efforts have focused on developing cultivars and germplasm with high fibre content. The current study examined eight elite potato clones and four commercial cultivars (checks) across six environments (three locations over two years) for their total dietary fibre (TDF), neutral detergent fibre (NDF), and soluble fibre (SF) content. Genotype by environment interaction (GEI) and stability analysis were conducted with SAS and GGE Biplot software. Significant genotypic (G), environmental (E) and GEI effects were found. The six environments differed in temperature and moisture levels, which were linked to levels of NDF and TDF. Some genotypes had high levels of stability for fibre content. GGE biplot analysis found no significant mega-environments for fibre components. Two elite clones (CV96044-3 and F05081) were identified as high fibre sources (13.3 and 14.4 %, respectively) compared to the other elite clones and commercial cultivars (e.g., Russet Burbank: 11.7 %). These lines may also be suitable as parents with high fibre and stability to breed into backgrounds with other desirable qualities.
Oral Administration of Oleic or Linoleic Acids Modulates the Production of Inflammatory Mediators by Rat Macrophages
Authors: Magdalon Juliana , Vinolo Marco A. R. , Rodrigues Hosana G. , Paschoal Vivian A. , Torres Rosângela P. , Mancini‐Filho Jorge , Calder Philip C. , Hatanaka Elaine , Curi Rui 
Published: June 2012

AbstractOleic (OLA) and linoleic (LNA) acids are commonly consumed fatty acids and they can modulate the inflammatory response, in which macrophages play an important role. The aim of this study was to investigate the effects of these two fatty acids on the production of inflammatory mediators by macrophages. Rats received oral administration of water (control), OLA or LNA (0.22 g/kg body weight) daily for 10 days and peritoneal resident macrophages were then isolated. Subsequently, they were seeded in culture plates and the production of various inflammatory mediators was assessed. Oral administration with OLA decreased the production of IL‐1β, IL‐6 and CINC‐2αβ by resident macrophages and LNA decreased the production of IL‐1β, IL‐6 and VEGF in the absence of lipopolysaccharide (LPS), although it accelerated IL‐1β release and decreased IL‐10 synthesis when cells were stimulated with LPS. Neither fatty acid affected the production of superoxide anion, hydrogen peroxide, nitrite, TNF‐α, PGE2, LTB4 or 15(S)‐HETE. Thus, OLA and LNA influence the production of several inflammatory mediators by macrophages.
Evaluating the In Vitro Metabolism of Docosahexaenoic Acid in Sheep Rumen Fluid
Authors: Aldai Noelia , Hervás Gonzalo , Belenguer Álvaro , Frutos Pilar , Mantecón Angel R. , Kramer John K. G. 
Published: June 2012

AbstractRumen metabolism (e.g., biohydrogenation) of dietary unsaturated fatty acids (FA) is one of the main reasons why ruminant fats tend to be highly saturated and contain many isomerized FA intermediates. The process by which long‐chain (20‐ to 24‐carbon FA) polyunsaturated FA (LC‐PUFA) are metabolized by rumen bacteria is not as well understood as that of linoleic or linolenic acids. In order to better understand the fate of LC‐PUFA in the rumen several concentrations of docosahexaenoic acid (DHA) were evaluated in in vitro batch incubations ranging from 100 to 1,500 μg per 6 mL of incubation volume using rumen fluid from sheep and incubated for 0, 1, 2, 3, and 6 h. From the results, it was shown that DHA was extensively metabolized at low (100 to 300 μg/6 mL incubation volume), but not at high level of inclusion (800 μg). At 300 μg of DHA most of the depleted DHA was recovered as LC‐DHA metabolites within the first 6 h of incubation, and at the lowest levels (100 μg of incubation volume) further metabolism is apparent at 6 h. Using SP‐2560 GC columns several LC‐DHA metabolites were shown to elute after 24:0 and just past DHA, a region generally free of interfering FA. The present in vitro study would appear to be a useful method to evaluate the production of DHA metabolites in combination with its depletion.
The co‐occurrence of substance use and bullying behaviors among U.S. adolescents: Understanding demographic characteristics and social influences
Authors: Luk Jeremy W. , Wang Jing , Simons‐Morton Bruce G. 
Published: June 2012

ABSTRACTThis study examined the co‐occurrence of subtypes of substance use and bullying behaviors using latent class analysis and evaluated latent class differences in demographic characteristics, peer and parental influences. Self‐reported questionnaire data were collected from a nationally representative sample (N = 7508) of 6–10th grade adolescents in the United States. Four latent classes were identified: the non‐involved (57.7%), substance users (19.4%), bullies (17.5%), and substance‐using bullies (5.4%). Older and Hispanic adolescents were more likely to be substance users and substance‐using bullies, whereas younger and African American adolescents were more likely to be bullies. Females were more likely to be substance users, whereas males were more likely to be bullies and substance‐using bullies. Spending more evenings with peers posed greater risks for substance use, bullying, and the co‐occurrence of both problem behaviors. Paternal knowledge exerted protective effects over‐and‐above the effects of maternal knowledge. Implications for prevention and intervention efforts are discussed.
Emergent clustering methods for empirical OM research
Authors: Brusco Michael J. , Steinley Douglas , Cradit J. Dennis , Singh Renu 
Published: June 2012

AbstractTo date, the vast majority of cluster analysis applications in OM research have relied on traditional hierarchical (e.g., Ward's algorithm) and nonhierarchical (e.g.,K‐means algorithms) methods. Although these venerable methods should continue to be employed effectively in the OM literature, we also believe there is a significant opportunity to expand the scope of clustering methods to emergent techniques. We provide an overview of some alternative clustering procedures (including advantages and disadvantages), identify software programs for implementing them, and discuss the circumstances where they might be employed gainfully in OM research. The implementation of emergent clustering methods in the OM literature should enable researchers to offer implications for practice that might not have been uncovered with traditional methods.
Feasibility of Using Active Video Gaming as a Means for Increasing Energy Expenditure in Three Nonambulatory Young Adults With Disabilities
Authors: Rowland Jennifer L. , Rimmer James H. 
Published: June 2012

ObjectiveTo examine the feasibility of adapting active video games (AVGs) for nonambulatory wheelchair users at functionally diverse levels and to examine these AVGs as a method for increasing energy expenditure (EE) for 3 young adults with severe (SEV), moderate (MOD), and no upper extremity limitation (NL).DesignCase study.SettingResidential special education school for youth and young adults with physical disabilities.ParticipantsTwo young adults with spastic cerebral palsy (SEV, MOD) and one young adult with spina bifida (NL). All participants were nonambulatory wheelchair users.MethodsEach participant performed Wii bowling and tennis and an adapted upper extremity version of a Dance Dance Revolution (DDR) game pad.Main Outcome MeasurementsEE was measured through indirect calorimetry (VO2). Heart rate data were collected with the use of a Polar Heart Rate Monitor.ResultsSEV and MOD participants showed a higher percentage increase in EE for the Wii games (SEV, 25.6%; MOD, 30.8%) compared with DDR (SEV, 10.8%; MOD, 29.1%), whereas the participant with NL had a greater EE increase for the DDR (173.5%) compared with Wii (59.5%).ConclusionsAVGs showed clinically significant increases in EE for all 3 participants and can be performed by nonambulatory wheelchair users ranging from those with NL to those with SEV upper extremity limitation with the appropriate adaptations.
The Immediate Effect of Kinesiology Taping on Muscular Imbalance for Infants With Congenital Muscular Torticollis
Authors: Öhman Anna M. 
Published: June 2012

ObjectiveTo investigate the immediate effect of kinesiology taping (KT) on muscular imbalance in the lateral flexors of the neck.DesignA retrospective study.ParticipantsTwenty‐eight infants with congenital muscular torticollis and muscular imbalance in the lateral flexors of the neck were chosen consecutively.MethodsData regarding the Muscle Function Scale (MFS) score before and after the first taping session were obtained from the records.ResultsA significant decrease in the difference between the MFS scores was found after KT was applied (P < .001). Significantly greater scores were noted on the unaffected side after KT (P = .02) and significantly lower scores were noted on the affected side after KT (P = .003). Multiple regression demonstrated that the MFS score on the unaffected side (P < .001) and use of the muscle‐relaxing technique (P = .009) were significantly associated with a decrease in the difference between the MFS scores of the 2 sides.ConclusionsKT has an immediate effect on muscular imbalance in infants with congenital muscular torticollis.
The Effect of a Prehabilitation Exercise Program on Quadriceps Strength for Patients Undergoing Total Knee Arthroplasty: A Randomized Controlled Pilot Study
Authors: McKay Carly , Prapavessis Harry , Doherty Timothy 
Published: June 2012

ObjectiveTo examine the effect of a 6‐week prehabilitation exercise training program on presurgical quadriceps strength for patients undergoing total knee arthroplasty (TKA).DesignTwo‐arm, parallel, randomized, controlled pilot trial.SettingPrivate exercise space in a research facility.ParticipantsTwenty‐two patients scheduled for primary TKA.MethodsParticipants completed a series of baseline questionnaires (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC], Short Form 36, and Arthritis Self‐efficacy Scale) and functional testing (isometric quadriceps strength assessment, flat‐surface walk test, and stair ascent‐descent test). The participants were randomized to a lower‐body strength training program or to a nonspecific upper‐body strength training program. The participants exercised 3 times per week for 6 weeks before TKA. Postintervention assessment occurred immediately before TKA, with follow‐up assessments at 6 and 12 weeks after surgery.OutcomesThe primary outcome was isometric quadriceps strength. Secondary outcomes were mobility, pain, self‐reported function, health‐related quality of life, and arthritis self‐efficacy.ResultsThere was no significant treatment condition–by‐time effect on quadriceps strength, but the effect size was large (F3,18 = 0.89, P = .47, η2 = 0.13). Similar findings were shown for walking speed (F3,18 = 1.47, P = .26, η2 = 0.20). There was a significant treatment‐by‐time effect for the Short Form 36 mental component score (F3,18 = 0.41, P = .02, η2 = 0.41), with differences emerging before surgery but not at either postoperative assessment. For all other secondary outcome measures, the treatment‐by‐time effect was nonsignificant and small.ConclusionThe intervention elicited clinically meaningful increases in quadriceps strength, walking speed, and mental health immediately before TKA. It did not impart lasting benefits to patients in the 12 weeks after surgery. Analysis of the results suggests that quadriceps strength may not drive functional improvements after surgery. These findings need to be replicated in larger trials before clinical recommendations are made about including strength training prehabilitation in everyday practice.
Amputation and Cardiac Comorbidity: Analysis of Severity of Cardiac Risk
Authors: Nallegowda Mallikarjuna , Lee Esther , Brandstater Murray , Kartono Alloysius B. , Kumar Guresh , Foster Gary P. 
Published: June 2012

ObjectiveTo evaluate population‐based cardiovascular risk scores and coronary artery calcification scores (CACS) in amputees.DesignA retrospective cohort study of 1300 veterans in a cardiac computed tomography database.Setting1B Veterans Administration medical center.ParticipantsA total of 76 amputees and similar number of age‐, gender‐, and Framingham Risk Scores (FRS)‐matched control subjects.MethodsThe amputee population was identified and compared for CACS and traditional cardiac risk factors. Two control groups were used: control group 1, with known risk factors including diabetes mellitus, and control group 2, with all risk factors without diabetes mellitus.Main Outcome MeasuresStatistical associations between amputee and control group FRS scores, CACS, and other cardiac risk factors were assessed.ResultsThe study included 57 nontraumatic and 19 traumatic amputees with an average age of 62.4 years. Sixty‐six amputees were in the low‐to‐intermediate cardiac risk groups according to FRS. Despite this classification, the mean CACS were significantly higher in amputees (1285 ± 18) than in either of the control groups: control group 1 (540 ± 84) and control group 2 (481 ± 11), P < .001. CACS also were significantly higher in the nontraumatic subject group (1595 ± 12) compared with the traumatic group (356 ± 57; P < .001). Upon categorization of CACS based on probability of coronary artery disease (CAD), 76% of amputees had a CACS >100 and 38% of amputees had a CACS >1000. Interestingly, CACS were almost the same in finger/toe amputations compared with an above‐knee amputation, indicating an already ongoing CAD process irrespective of level of amputation. The predominant clinical significant cardiac risk factors in amputees are hypertension (89.5%), P < .005; chronic kidney disease (31.6%), P < .001; dyslipidemia (72.4%), P < .04; and insulin resistance. Total cholesterol, low‐density lipoprotein, and high‐density lipoprotein levels were nonsignificantly low in all amputees. Triglycerides were particularly higher in traumatic patients compared with nontraumatic patients, with the triglycerides/high‐density lipoprotein ratio >7.ConclusionThis study demonstrates that amputees have a much greater burden of underlying atherosclerotic disease as detected by CACS than do control subjects matched by Framingham risk stratification. Early screening for CAD and aggressive targeted interventions may be an important part of management to reduce early mortality after amputation.
Vortex–wave interactions: long-wavelength streaks and spatial localization in natural convection
Authors: Hall Philip 
Published: June 2012

AbstractThe unidirectional shear flow driven by buoyancy effects in a vertical channel when a temperature difference is maintained between the walls of the channel is considered. The flow is unstable to waves which interact to reinforce the original flow and make it ‘streaky’. Such ‘vortex–wave’ interactions have been the subject of much recent research but little is yet known about what happens when the wavelength of the roll/streak flow becomes large. An asymptotic structure for long-wavelength interactions is derived and the tendency of the fluid to resist this state and the flow to become localized is revealed. Here the high-Grashof-number limit is considered and it is shown how a self-sustained process can occur with vortices interacting with a wave system in a manner similar to that discussed by Hall & Smith (J. Fluid Mech., vol. 227, 1991, pp. 641–666) and Hall & Sherwin (J. Fluid Mech., vol. 661, 2010, pp. 178–205). The work is closely related to numerical simulations of self-sustained processes in for example Couette flow but the fact that the basic flow here is generated by buoyancy effects enables us to make analytical progress. It is shown that the wave part of the interaction process has a flat critical layer and its wavelength is twice that of the streaky flow which supports it. Such subharmonic vortex–wave/self-sustained process interactions have not been previously identified.
The starting vortex in quiescent air induced by dielectric-barrier-discharge plasma
Authors: Whalley Richard D. , Choi Kwing-So 
Published: June 2012

AbstractThe flow field around an asymmetric dielectric-barrier-discharge (DBD) plasma actuator in quiescent air is studied using particle image velocimetry (PIV) and smoke-flow visualization. On initiation of DBD plasma a starting vortex is created, which rolls up to form a coherent structure. The starting vortex becomes self-similar when the maximum velocity induced by the DBD plasma actuator reaches a steady state. Here, the plasma jet momentum increases linearly with time, suggesting that the DBD plasma actuator entrains and accelerates the surrounding fluid with a constant force. The wall-parallel and wall-normal distances of the vortex core are observed to scale with ${t}^{2/ 3} $ as it travels at $3{1}^{\circ } $ to the wall. The velocity of the starting vortex is found to scale with ${t}^{- 1/ 3} $, while the circulation induced by the plasma actuator scales with ${t}^{1/ 3} $.