bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental assessment of the network properties of the Drosophila circadian clock
Authors: Beckwith Esteban J. , Ceriani M. Fernanda 
Published: December 2014

ABSTRACTCircadian rhythms are conserved across kingdoms and coordinate physiology and behavior for appropriate time‐keeping. The neuronal populations that govern circadian rhythms are described in many animal models, and the current challenge is to understand how they interact to control overt rhythms, remaining plastic enough to respond and adapt to a changing environment. In Drosophila melanogaster, the circadian network comprises about 150 neurons, and the main synchronizer is the neuropeptide pigment‐dispersing factor (PDF), released by the well‐characterized central pacemaker neurons, the small ventral lateral neurons (sLNvs). However, the rules and properties governing the communication and coupling between this central pacemaker and downstream clusters are not fully elucidated. Here we genetically manipulate the speed of the molecular clock specifically in the central pacemaker neurons of Drosophila and provide experimental evidence of their restricted ability to synchronize downstream clusters. We also demonstrate that the sLNv‐controlled clusters have an asymmetric entrainment range and were able to experimentally assess it. Our data imply that different clusters are subjected to different coupling strengths, and display independent endogenous periods. Finally, the manipulation employed here establishes a suitable paradigm to test other network properties as well as the cell‐autonomous mechanisms running in different circadian‐relevant clusters. J. Comp. Neurol. 523:982–996, 2015. © 2014 Wiley Periodicals, Inc.
Functional beverage of Garcinia mangostana (mangosteen) enhances plasma antioxidant capacity in healthy adults
Authors: Xie Zhuohong , Sintara Marsha , Chang Tony , Ou Boxin 
Published: December 2014

AbstractThis study was to investigate the absorption and antioxidant effect of a mangosteen‐based functional beverage in humans. The beverage contained mangosteen, aloe vera, green tea, and multivitamins. A randomized, double‐blind, placebo‐controlled clinical trial was conducted with generally healthy male and female subjects between 18 and 60 years of age. Ten men and 10 women participated in this study. Participants were randomly divided into two groups, treatment and placebo group. Participants received either a daily single dose (245 mL) of the beverage or a placebo. Blood samples were collected from each participant at time points 0, 1, 2, 4, and 6 h. The plasma samples were analyzed by LC/MS for α‐mangostin and vitamins B2 and B5. Results indicated that the three analytes were bioavailable, with observed Cmax at around 1 h. The antioxidant capacity measured with the oxygen radical absorbance capacity (ORAC) assay was increased with a maximum effect of 60% after 1 h, and the elevated antioxidant level lasted at least 6 h. This study demonstrated the bioavailability of α‐mangostin and B vitamins from a xanthone‐rich beverage and the mechanisms of the increase in plasma antioxidant may be direct effects from antioxidants, enhancement of endogenous antioxidant activity through activation of Nrf2 pathway, and synergism of the antioxidants.
Genetic Data Simulators and their Applications: An Overview
Authors: Peng Bo , Chen Huann‐Sheng , Mechanic Leah E. , Racine Ben , Clarke John , Gillanders Elizabeth , Feuer Eric J. 
Published: December 2014

ABSTRACTComputer simulations have played an indispensable role in the development and applications of statistical models and methods for genetic studies across multiple disciplines. The need to simulate complex evolutionary scenarios and pseudo‐datasets for various studies has fueled the development of dozens of computer programs with varying reliability, performance, and application areas. To help researchers compare and choose the most appropriate simulators for their studies, we have created the genetic simulation resources (GSR) website, which allows authors of simulation software to register their applications and describe them with more than 160 defined attributes. This article summarizes the properties of 93 simulators currently registered at GSR and provides an overview of the development and applications of genetic simulators. Unlike other review articles that address technical issues or compare simulators for particular application areas, we focus on software development, maintenance, and features of simulators, often from a historical perspective. Publications that cite these simulators are used to summarize both the applications of genetic simulations and the utilization of simulators.
Imaging distributed and massed repetitions of natural scenes: Spontaneous retrieval and maintenance
Authors: Bradley Margaret M. , Costa Vincent D. , Ferrari Vera , Codispoti Maurizio , Fitzsimmons Jeffrey R. , Lang Peter J. 
Published: December 2014

AbstractRepetitions that are distributed (spaced) across time prompt enhancement of a memory‐related event‐related potential, compared to when repetitions are massed (contiguous). Here, we used fMRI to investigate neural enhancement and suppression effects during free viewing of natural scenes that were either novel or repeated four times with massed or distributed repetitions. Distributed repetition was uniquely associated with a repetition enhancement effect in a bilateral posterior parietal cluster that included the precuneus and posterior cingulate and which has previously been implicated in episodic memory retrieval. Unique to massed repetition, conversely, was enhancement in a right dorsolateral prefrontal cluster that has been implicated in short‐term maintenance. Repetition suppression effects for both types of spacing were widespread in regions activated during novel picture processing. Taken together, the data are consistent with a hypothesis that distributed repetition prompts spontaneous retrieval of prior occurrences, whereas massed repetition prompts short‐term maintenance of the episodic representation, due to contiguous presentation. These processing differences may mediate the classic spacing effect in learning and memory. Hum Brain Mapp 36:1381–1392, 2015. © 2014 Wiley Periodicals, Inc.
Accessing orthographic representations from speech: The role of left ventral occipitotemporal cortex in spelling
Authors: Ludersdorfer Philipp , Kronbichler Martin , Wimmer Heinz 
Published: December 2014

AbstractThe present fMRI study used a spelling task to investigate the hypothesis that the left ventral occipitotemporal cortex (vOT) hosts neuronal representations of whole written words. Such an orthographic word lexicon is posited by cognitive dual‐route theories of reading and spelling. In the scanner, participants performed a spelling task in which they had to indicate if a visually presented letter is present in the written form of an auditorily presented word. The main experimental manipulation distinguished between an orthographic word spelling condition in which correct spelling decisions had to be based on orthographic whole‐word representations, a word spelling condition in which reliance on orthographic whole‐word representations was optional and a phonological pseudoword spelling condition in which no reliance on such representations was possible. To evaluate spelling‐specific activations the spelling conditions were contrasted with control conditions that also presented auditory words and pseudowords, but participants had to indicate if a visually presented letter corresponded to the gender of the speaker. We identified a left vOT cluster activated for the critical orthographic word spelling condition relative to both the control condition and the phonological pseudoword spelling condition. Our results suggest that activation of left vOT during spelling can be attributed to the retrieval of orthographic whole‐word representations and, thus, support the position that the left vOT potentially represents the neuronal equivalent of the cognitive orthographic word lexicon. Hum Brain Mapp, 36:1393–1406, 2015. © 2014 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.
Functional connectivity associated with gait velocity during walking and walking‐while‐talking in aging: A resting‐state fMRI study
Authors: Yuan Jennifer , Blumen Helena M. , Verghese Joe , Holtzer Roee 
Published: December 2014

AbstractGait decline is common among older adults and is a risk factor for adverse outcomes. Poor gait performance in dual‐task conditions, such as walking while performing a secondary cognitive interference task, is associated with increased risk of frailty, disability, and death. Yet, the functional neural substrates that support locomotion are not well established. We examined the functional connectivity associated with gait velocity in single‐ (normal pace walking) and dual‐task (walking while talking) conditions using resting‐state functional Magnetic Resonance Imaging (fMRI). We acquired 6 minutes of resting‐state fMRI data in 30 cognitively healthy older adults. Independent components analyses were performed to separate resting‐state fMRI data into group‐level statistically independent spatial components that correlated with gait velocity in single‐ and dual‐task conditions. Gait velocity in both task conditions was associated with similar functional connectivity in sensorimotor, visual, vestibular, and left fronto‐parietal cortical areas. Compared to gait velocity in the single‐task condition, the networks associated with gait velocity in the dual‐task condition were associated with greater functional connectivity in supplementary motor and prefrontal regions. Our findings show that there are partially overlapping functional networks associated with single‐ and dual‐task walking conditions. These initial findings encourage the future use of resting‐state fMRI as tool in developing a comprehensive understanding of age‐related mobility impairments. Hum Brain Mapp 36:1484–1493, 2015. © 2014 Wiley Periodicals, Inc.
Cerebellar white matter pathways are associated with reading skills in children and adolescents
Authors: Travis Katherine E. , Leitner Yael , Feldman Heidi M. , Ben‐Shachar Michal 
Published: December 2014

AbstractReading is a critical life skill in the modern world. The neural basis of reading incorporates a distributed network of cortical areas and their white matter connections. The cerebellum has also been implicated in reading and reading disabilities. However, little is known about the contribution of cerebellar white matter pathways to major component skills of reading. We used diffusion magnetic resonance imaging (dMRI) with tractography to identify the cerebellar peduncles in a group of 9‐ to 17‐year‐old children and adolescents born full term (FT, n = 19) or preterm (PT, n = 26). In this cohort, no significant differences were found between fractional anisotropy (FA) measures of the peduncles in the PT and FT groups. FA of the cerebellar peduncles correlated significantly with measures of decoding and reading comprehension in the combined sample of FT and PT subjects. Correlations were negative in the superior and inferior cerebellar peduncles and positive in the middle cerebellar peduncle. Additional analyses revealed that FT and PT groups demonstrated similar patterns of reading associations within the left superior cerebellar peduncle, middle cerebellar peduncle, and left inferior cerebellar peduncle. Partial correlation analyses showed that distinct sub‐skills of reading were associated with FA in segments of different cerebellar peduncles. Overall, the present findings are the first to document associations of microstructure of the cerebellar peduncles and the component skills of reading. Hum Brain Mapp 36:1536–1553, 2015. © 2014 Wiley Periodicals, Inc.
Antenatal sonographic diagnosis of choledochal cyst: Case report and imaging review
Authors: Jensen Kyle K. , Sohaey Roya 
Published: December 2014

ABSTRACTIn this report, we present the antenatal two‐ and three‐dimensional sonographic findings from a fetus with choledochal cyst as well as confirmatory postnatal MRI. A delayed diagnosis of choledochal cyst is common, leading to significant morbidity and mortality. Visualizing bile ducts entering a right upper quadrant cyst is pathognomonic, and early diagnosis can facilitate definitive treatment with Roux‐en‐Y hepaticojejunostomy. © 2014 Wiley Periodicals, Inc. J Clin Ultrasound 43:581–583, 2015
Submandibular venous hemangioma: Case report and review of the literature
Authors: Wallace Adam N. , Vyhmeister Ross , Kamran Mudassar , Teefey Sharlene A. 
Published: December 2014

ABSTRACTHemangiomas of the submandibular space are very rare. Only 11 cases have been reported in the English literature, all of which were cavernous hemangiomas. In this report, we describe the case of a venous hemangioma in a 70‐year‐old woman. Ultrasound examination revealed a lobulated, homogeneous, hypoechoic mass, and minimal flow was detected on power Doppler evaluation. The mass and the submandibular gland were surgically excised, and the endothelium was found to be positive for CD31 and D2‐40 markers, consistent with venous hemangioma. To our knowledge, this is the first reported case of a venous hemangioma in the submandibular space. © 2014 Wiley Periodicals, Inc. J Clin Ultrasound 43:516–519 2015
Solid pseudopapillary tumors of the pancreas: Findings from routine screening sonographic examination and the value of contrast‐enhanced ultrasound
Authors: Jiang Ling , Cui Ligang , Wang Jinrui , Chen Wen , Miao Liying , Jia Jianwen 
Published: December 2014

ABSTRACTBackgroundSolid pseudopapillary tumors (SPTs) are rare neoplasms of the pancreas. We describe the features of these small tumors identified on routine screening sonographic (US) examination and the potential value of using contrast‐enhanced ultrasound (CEUS) scanning.MethodsWe retrospectively reviewed records from 17 patients who had undergone screening via US examination at Peking University Third Hospital between January 2000 and June 2011. Each of these patients had been confirmed by a pathologist to have an SPT. Six patients had undergone CEUS prior to surgery. We recorded all features on both gray‐scale US and CEUS.ResultsAll patients (4 men and 13 women; ages 23–35 years; mean age, 27.2 years) were initially screened by US. The largest mass identified was 5.0 cm in diameter (mean diameter, 4.2 cm), and most tumors showed homogeneous hypoechogenicity. A hyperechoic rim was detected in four masses. CEUS showed peripheral‐rim hyperenhancement in the arterial phase of all six masses.ConclusionsRoutine screening US examinations are capable of identifying small (<5.0 cm) SPTs. These screening examinations allow diagnosis on the basis of typical imaging features, such as a homogeneously hypoechoic mass with a hyperechoic rim. CEUS shows greater detail of the rim and cystic areas in the tumor, which significantly improves the proper diagnosis. © 2014 Wiley Periodicals, Inc. J Clin Ultrasound, 2014 © 2014 Wiley Periodicals, Inc. J Clin Ultrasound 43:277–282, 2015
Comparison of noncontrast MRI magnetization transfer and T2‐Weighted signal intensity ratios for detection of bowel wall fibrosis in a Crohn's disease animal model
Authors: Dillman Jonathan R. , Swanson Scott D. , Johnson Laura A. , Moons David S. , Adler Jeremy , Stidham Ryan W. , Higgins Peter D.R. 
Published: December 2014

PurposeTo compare the abilities of magnetization transfer magnetic resonance imaging (MT‐MRI) and T2‐weighted signal intensity (T2WSI) ratios to detect intestinal fibrosis in a Crohn's disease animal model.Materials and MethodsTen rats ("Group 1") received one trinitrobenzenesulfonic acid enema to induce acute colonic inflammation, while 10 additional animals ("Group 2") received multiple enemas to induce colonic inflammation and fibrosis. Gradient recalled‐echo MT‐MRI (5 and 10 kHz off‐resonance) and T2‐weighted spin‐echo imaging were performed 2 days after the last enema. MT ratios (MTR) and T2WSI ratios were calculated in the area of greatest colonic thickening. Bowel wall MTR, bowel wall MTR normalized to paraspinous muscle MTR ("normalized MTR"), and T2WSI ratios were compared between animal groups using Student's t‐test.ResultsAt 10 kHz off‐resonance, mean bowel wall MTR for Group 1 was 24.8 ± 3.1% vs. 30.3 ± 3.2% for Group 2 (P = 0.001). Mean normalized MTR was 0.45 ± 0.05 for Group 1 and 0.58 ± 0.08 for Group 2 (P = 0.0003). At 5 kHz off‐resonance, mean bowel wall MTR for Group 1 was 34.7 ± 5.2% vs. 40.3 ± 3.6% for Group 2 (P = 0.015). Mean normalized MTR was 0.53 ± 0.08 for Group 1 and 0.64 ± 0.07 for Group 2 (P = 0.003). Mean T2WSI ratio was 5.32 ± 0.98 for Group 1 and 3.01 ± 0.66 for group 2 (P < 0.0001). Mean T2WSI ratio/MTR (10 kHz off‐resonance) was 12.06 ± 2.70 for Group 1 and 5.22 ± 1.29 for Group 2 (P < 0.0001), with an ROC c‐statistic of 0.98.ConclusionMTR and T2WSI ratios detect bowel wall fibrosis in a Crohn's disease animal model. J. Magn. Reson. Imaging 2015;42:801–810.
Post‐activation potentiation: The neural effects of post—activation depression
Authors: Xenofondos Anthi , Patikas Dimitrios , Koceja David M. , Behdad Tahayori , Bassa Eleni , Kellis Eleftherios , Kotzamanidis Christos 
Published: December 2014

ABSTRACTIntroduction: Our knowledge of the neurophysiology of post‐activation potentiation (PAP) is limited. The purpose of this study was to examine the effect of PAP on twitch torque and H‐reflex amplitude after a 10‐s maximal voluntary contraction (MVC). Methods: PAP measurements were assessed with the plantarflexors in a relaxed state and during a tonic contraction at 10% MVC. Results: The H‐reflex/maximum M‐wave ratio (H/M) decreased significantly (P < 0.05) and returned to baseline levels after 1 min. The decrement in H/M was depressed when the plantarflexors were active at 10% MVC, and the depression was more obvious in the lateral gastrocnemius than in the soleus muscle. Conclusions: The inhibition induced immediately after contraction could be attributed to post‐activation depression. We conclude that PAP after a 10‐s MVC cannot be attributed to increased motor neuron excitability through the reflex pathway as assessed by the H‐reflex technique. Muscle Nerve 52: 252–259, 2015
A learning tabu search for a truck allocation problem with linear and nonlinear cost components
Authors: Schindl David , Zufferey Nicolas 
Published: December 2014

AbstractThe two‐level problem studied in this article consists of optimizing the refueling costs of a fleet of locomotives over a railway network. The goal consists of determining: (1) the number of refueling trucks contracted for each yard (truck assignment problem denoted TAP) and (2) the refueling plan of each locomotive (fuel distribution problem denoted FDP). As the FDP can be solved efficiently with existing methods, the focus is put on the TAP only. In a first version of the problem (denoted (P1)), various linear costs (e.g., fuel, fixed cost associated with each refueling, weekly operating costs of trucks) have to be minimized while satisfying a set of constraints (e.g., limited capacities of the locomotives and the trucks). In contrast with the existing literature on this problem, two types of nonlinear cost components will also be considered, based on the following ideas: (1) if several trucks from the same fuel supplier are contracted for the same yard, the supplier is likely to propose discounted prices for that yard (Problem (P2)); (2) if a train stops too often on its route, a penalty is incurred, which represents the dissatisfaction of the clients (Problem (P3)). Even if exact methods based on a mixed integer linear program formulation are available for (P1), they are not appropriate anymore to tackle (P2) and (P3). Various methods are proposed for the TAP: a descent local search, a tabu search, and a learning tabu search (LTS). The latter is a new type of local search algorithm. It involves a learning process relying on a trail system, and it can be applied to any combinatorial optimization problem. Results are reported and discussed for a large set of instances (for (P1), (P2), and (P3)), and show the good performance of LTS. © 2014 Wiley Periodicals, Inc. 62:32–45, 2015
NURBS based least‐squares finite element methods for fluid and solid mechanics
Authors: Kadapa C. , Dettmer W.G. , Perić D. 
Published: December 2014

SummaryThis contribution investigates the performance of a least‐squares finite element method based on non‐uniform rational B‐splines (NURBS) basis functions. The least‐squares functional is formulated directly in terms of the strong form of the governing equations and boundary conditions. Thus, the introduction of auxiliary variables is avoided, but the order of the basis functions must be higher or equal to the order of the highest spatial derivatives. The methodology is applied to the incompressible Navier–Stokes equations and to linear as well as nonlinear elastic solid mechanics. The numerical examples presented feature convective effects and incompressible or nearly incompressible material. The numerical results, which are obtained with equal‐order interpolation and without any stabilisation techniques, are smooth and accurate. It is shown that for p and h refinement, the theoretical rates of convergence are achieved. Copyright © 2014 John Wiley & Sons, Ltd.
Structural and morphological studies on the deformation behavior of polypropylene/multi‐walled carbon nanotubes nanocomposites prepared through ultrasound‐assisted melt extrusion process
Authors: Mata‐Padilla José M. , Ávila‐Orta Carlos A. , Medellín‐Rodríguez Francisco J. , Hernández‐Hernández Ernesto , Jiménez‐Barrera Rosa M. , Crúz‐Delgado Víctor J. , Valdéz‐Garza Janett , Solís‐Rosales Silvia G. , Torres‐Martínez Adriana , Lozano‐Estrada Myriam , Díaz‐Barriga Castro Enrique 
Published: December 2014

ABSTRACTStructural and morphological behavior under stress–strain of polypropylene/multi‐walled carbon nanotubes (PP/MWCNTs) nanocomposites prepared through ultrasound‐assisted melt extrusion process was studied by means of optical microscopy, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, small angle X‐ray scattering (SAXS), and wide angle X‐ray scattering (WAXS). A high ductile behavior was observed in the PP/MWCNT nanocomposites with low concentration of MWCNTs. This was related to an energy‐dissipating mechanism, achieved by the formation of an ordered PP‐CNTs interphase zone and crystal oriented structure in the undeformed samples. Different strain‐induced‐phase transformations were observed by ex situ SAXS/WAXS, characterizing the different stages of structure development during the deformation of PP and PP/MWCNTs nanocomposites. The high concentration of CNTs reduced the strain behavior of PP due to the agglomeration of nanoparticles. A structural pathway relating the deformation‐induced phase transitions and the dissipation energy mechanism in the PP/MWCNTs nanocomposites at low concentration of nanoparticles was proposed. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015, 53, 475–491