bluuebunny/crossref_metadata_2025_split huggingface dataset:
Altered cingulum bundle microstructure in autism spectrum disorder
Authors: Ameis Stephanie H. , Fan Jin , Rockel Conrad , Soorya Latha , Wang A. Ting , Anagnostou Evdokia 
Published: May 2013

ObjectiveHere, we examined the cingulum bundle, a long-range white matter tract mediating dorsal limbic connectivity, using diffusion tensor imaging (DTI) tractography, in children and adolescents with autism spectrum disorder (ASD) versus controls. We hypothesised that cingulum bundle microstructure would be altered in ASD, based on evidence implicating abnormal white matter connectivity in this disorder.MethodsDTI data were acquired for 19 ASD participants (IQ ⩾ 70; 7–18 years; mean = 12.4 ± 3.1) and 16 age-matched controls (7–18 years; mean = 12.3 ± 3.6) on a 3 T magnetic resonance imaging system. Deterministic tractography was used to isolate the cingulum bundle. Left and right cingulum bundles were examined for differences in several DTI metrics in ASD children/adolescents versus controls, including: fractional anisotropy (FA), mean, axial, and radial diffusivity.ResultsSignificant age × group interaction effects were found for all DTI metrics (mean diffusivity: F1,28 = 9.5, p = 0.005, radial diffusivity: F1,28 = 7.8, p = 0.009, axial diffusivity: F1,28 = 5.2, p = 0.03, FA: F1,28 = 4.4, p = 0.04). Interaction effects were driven by increases in cingulum bundle diffusivity (mean, radial, and axial diffusivity), and decreased FA, in younger ASD participants within our sample versus controls.ConclusionOur results point to immature microstructural organisation of the cingulum bundle in ASD, particularly during the early years of life, with implications for limbic network synchronisation and complex socio-emotional performance.
Depressive symptomatology and pineal epidermoid cyst: a case report
Authors: Kontoangelos Konstantinos , Economou Marina , Maltezou Maria , Kandaraki Anna , Papadimitriou George N. 
Published: May 2013

IntroductionIntracranial epidermoid cysts are congenital cysts. They comprise 0.2–1.8% of primary intracranial tumours and are four to nine times as common as dermoid cysts.Case reportWe here in present the case of a 32-year-old man who reported sudden onset of symptoms of a depressive symptomatology and particularly severe headache, accompanied by fatigue, depressed mood most of the day, marked diminished interest or pleasure in all or almost all activities, insomnia and diminished ability to think or concentrate. Brain magnetic resolution imaging examination revealed a pineal epidermoid cystic lesion, visualised in the posterior part of the third ventricle, with a maximum diameter of ∼2.8 cm and obstructing the aqueduct of Sylvius, causing obstructive hydrocephalus.DiscussionPineal cysts may enlarge over time, because of either increased cyst fluid or intracystic haemorrhage, and become symptomatic. Brain radiological investigations in patients with depressive symptomatology may be substantial.
Discrete kinematic synthesis of discretely actuated hyper-redundant manipulators
Authors: Motahari Alireza , Zohoor Hassan , Korayem M. Habibnejad 
Published: May 2013

SUMMARYDiscrete kinematic synthesis of discretely actuated hyper-redundant manipulators is a new practical problem in robotics. The problem concerns with determining the type of each manipulator module from among several specific types, so that the manipulator could reach several specified target frames with the lowest error. This paper suggests using a breadth-first search method and a workspace mean frame to solve this problem. To reduce errors, two heuristic ideas are proposed: two-by-two searching method and iteration. The effectiveness of the proposed method is verified through several numerical problems.
A generalized scheme for the global adaptive regulation of robot manipulators with bounded inputs
Authors: López-Araujo D. J. , Zavala-Río A. , Santibáñez V. , Reyes F. 
Published: May 2013

SUMMARYIn this work, a generalized adaptive control scheme for the global position stabilization of robot manipulators with bounded inputs is proposed. It gives rise to various families of bounded controllers with adaptive gravity compensation. Compared with the adaptive approaches previously developed in a bounded-input context, the proposed scheme guarantees the adaptive regulation objective: globally, avoiding discontinuities in the control expression as well as in the adaptation auxiliary dynamics, preventing the inputs to reach their natural saturation bounds, and imposing nosaturation-avoidancerestriction on the control gains. Experimental results corroborate the efficiency of the proposed adaptive scheme.
Minimum control effort trajectory planning and tracking of the CEDRA brachiation robot
Authors: Meghdari Ali , Lavasani Seyyed Mohammad H. , Norouzi Mohsen , Mousavi Mir Saman Rahimi 
Published: May 2013

SUMMARYThe control of a brachiation robot has been the primary objective of this study. A brachiating robot is a type of a mobile arm that is capable of moving from branch to branch similar to a long-armed ape. In this paper, to minimize the actuator work, Pontryagin's minimum principle was used to obtain the optimal trajectories for two different problems. The first problem considers “brachiation between fixed branches with different distance and height,” whereas the second problem deals with the “brachiating and catching of a moving target branch”. Theoretical results show that the control effort in the proposed method is reduced by 25% in comparison with the “target dynamics” method which was proposed by Nakanishi et al. (1998)16 for the same type of robot. As a result, the obtained optimal trajectory also minimizes the brachiation time. Two kinds of controllers, namely the proportional-derivative (PD) and the adaptive robust (AR), were investigated for tracking the proposed trajectories. Then, the previous method on a set-point controller for acrobat robots is improved to represent a new AR controller which allows the system to track the desired trajectory. This new controller has the capability to be used in systems which have uncertainties in the kinematic and dynamic parameters. Finally, theoretical results are presented and validated with experimental observations with a PD controller due to the no chattering phenomenon and small computational efforts.
Modeling tendon-sheath mechanism with flexible configurations for robot control
Authors: Wang Zheng , Sun Zhenglong , Phee Soo Jay 
Published: May 2013

SUMMARYSurgical and search/rescue robots often work in environments with very strict spatial constraints. The tendon-sheath mechanism is a promising candidate for driving such systems, allowing power sources and actuation motors placed outside to transmit force and energy to the robot at the distal end through the constrained environment. Having both compactness and high force capability makes it very attractive for manipulation devices. On the other hand, the friction attenuation of tendon tension is nonlinear and configuration-dependent due to tendon/sheath interactions throughout the transmission path. This is a major obstacle for the tendon-sheath mechanism to be widely adopted. Here, we focus on the friction analysis for flexible and time-varying tendon-sheath configurations: the most challenging but yet commonly encountered case for real-world applications. Existing results on fixed-path configurations are reviewed, revisited, and extended to flexible and time-varying cases. The effect of tendon length to friction attenuation is modeled. While focusing on tension transmission, tendon elongation is also discussed with the length effect applied. In the end, two-dimensional results are extended to three-dimensional tendon-sheath configurations. All propositions and theorems are validated on a dedicated experimental platform.
Walk-through programming for robotic manipulators based on admittance control
Authors: Bascetta Luca , Ferretti Gianni , Magnani Gianantonio , Rocco Paolo 
Published: May 2013

SUMMARYThe present paper addresses the issues that should be covered in order to develop walk-through programming techniques (i.e. a manual guidance of the robot) in an industrial scenario. First, an exact formulation of the dynamics of the tool the human should feel when interacting with the robot is presented. Then, the paper discusses a way to implement such dynamics on an industrial robot equipped with an open robot control system and a wrist force/torque sensor, as well as the safety issues related to the walk-through programming. In particular, two strategies that make use of admittance control to constrain the robot motion are presented. One slows down the robot when the velocity of the tool centre point exceeds a specified safety limit, the other one limits the robot workspace by way of virtual safety surfaces. Experimental results on a COMAU Smart Six robot are presented, showing the performance of the walk-through programming system endowed with the two proposed safety strategies.
Randomized path planning with preferences in highly complex dynamic environments
Authors: Belghith Khaled , Kabanza Froduald , Hartman Leo 
Published: May 2013

SUMMARYIn this paper we consider the problem of planning paths for articulated bodies operating in workplaces containing obstacles and regions with preferences expressed as degrees of desirability. Degrees of desirability could specify danger zones and desire zones. A planned path should not collide with the obstacles and should maximize the degrees of desirability. Region desirability can also convey search-control strategies guiding the exploration of the search space. To handle desirability specifications, we introduce the notion of flexible probabilistic roadmap (flexible PRM) as an extension of the traditional PRM. Each edge in a flexible PRM is assigned a desirability degree. We show that flexible PRM planning can be achieved very efficiently with a simple sampling strategy of the configuration space defined as a trade-off between a traditional sampling oriented toward coverage of the configuration space and a heuristic optimization of the path desirability degree. For path planning problems in dynamic environments, where obstacles and region desirability can change in real time, we use dynamic and anytime search exploration strategies. The dynamic strategy allows the planner to replan efficiently by exploiting results from previous planning phases. The anytime strategy starts with a quickly computed path with a potentially low desirability degree which is then incrementally improved depending on the available planning time.
Multibody modeling and vibration testing of 3R planar manipulators: effects of flexible installation frames
Authors: Mucchi Emiliano , Fiorati Stefano , Di Gregorio Raffaele , Dalpiaz Giorgio 
Published: May 2013

SUMMARYThis work presents the experimental validation and updating of a flexible multibody model ideated for taking into account installation conditions of industrial serial planar manipulators without resorting to cumbersome modeling. The flexibility of the frame, the manipulator is fixed, is modeled over the flexibility of joints, which is introduced as lumped stiffness. In particular, the flexible frame is included in the model by using the Component Mode Synthesis methodology, in which only the natural modes of vibration and the static constrain modes are accounted. The flexible multibody model has been developed because these commercial machines are mainly used to perform low-speed tasks, and they are designed by taking into account their flexibility at most in the joints. Unfortunately, there are particular installation conditions in which even low-speed tasks can generate low-frequency vibrations that highly interfere with the task. This aspect is considered here, and how to manage this problem is explained by using the developed multibody model. The model is validated through experimental measurements. The experimental tests consist of several modal analyses, together with acceleration and laser Doppler measurements in operational conditions. This methodology takes into account the installation conditions through the model of flexible frame, and gives a tool for studying ad hoc solutions which prevent the occurrence of unwanted low-frequency vibrations.
Intramuscular small vessel arteriovenous malformation of the left ventricle in an asymptomatic adolescent: a case report and literature review
Authors: McCammond Amy N. , Rudzinski Erin R. , Morrison Brian J. , Silberbach Michael 
Published: May 2013

AbstractPrimary vascular tumours of the heart are rare and heterogeneous in their presentation and classification. We present a primary intramuscular vascular malformation of the left ventricle in an asymptomatic 12-year-old girl. Characteristics on cardiac magnetic resonance imaging, specifically increased signal intensity on T2-weighted images, and marked contrast enhancement with gadolinium were suggestive of increased vascularity. Histologically, the mass was determined to be an intramuscular vascular malformation of the small vessel arteriovenous subtype. This represents one of a select few intramuscular vascular malformations of the left ventricle reported in children. Our patient remains completely asymptomatic and has had no change in the size and appearance of the mass after more than 30 months of follow-up.
Accidental finding of a giant right coronary artery aneurysm associated with a fistula to the right atrium
Authors: Vaz Silva Patrícia , Marinho Joana Castro , Pires António 
Published: May 2013

AbstractCoronary artery fistulae are uncommon but may be haemodynamically significant, being an incidental finding in 0.1–0.2% of coronary angiograms. Even rarer is the association between fistulae and non-atherosclerotic coronary artery aneurysms. They most frequently originate in the right coronary artery, and the right cardiac chambers are the most common draining chambers. Most children are asymptomatic, whereas those older than 20 years may present with signs of congestive heart failure, infective endocarditis, myocardial ischaemia, or aneurysm rupture. Management is either surgical or via percutaneous means. We report the case of a 5-year-old child referred for assessment of an asymptomatic cardiac murmur. The echocardiographic evaluation showed an enlarged right atrium, a fenestrated atrial septal defect, and a giant right coronary artery aneurysm with a fistulous tract that appeared to drain directly into the right atrium. Computed angiocardiac tomography and cardiac catherisation confirmed the presence of a large right coronary fistula originating from the right coronary aneurysm draining into the right atrium. The patient underwent surgical ligation of the fistula and the post-operative course has been uneventful. He is currently on double antiaggregation therapy.
The polyserine domain of the lysyl-5 hydroxylase Jmjd6 mediates subnuclear localization
Authors: Wolf Alexander , Mantri Monica , Heim Astrid , Müller Udo , Fichter Erika , Mackeen Mukram M. , Schermelleh Lothar , Dadie Gregory , Leonhardt Heinrich , Vénien-Bryan Catherine , Kessler Benedikt M. , Schofield Christopher J. , Böttger Angelika 
Published: May 2013

Jmjd6 (jumonji-domain-containing protein 6) is an Fe(II)- and 2OG (2-oxoglutarate)-dependent oxygenase that catalyses hydroxylation of lysine residues in proteins involved in pre-mRNA splicing. Jmjd6 plays an essential role in vertebrate embryonic development and has been shown to modulate alternative splicing in response to hypoxic stress. In the present study we show that an alternatively spliced version of Jmjd6 lacking the polyS (polyserine) domain localizes to the nucleolus, predominantly in the fibrillar centre. Jmjd6 with the polyS domain deleted also interacts with nucleolar proteins. Furthermore, co-immunoprecipitation experiments and F2H (fluorescent 2-hybrid) assays demonstrate that Jmjd6 homo-oligomerization occurs in cells. In correlation with the observed variations in the subnuclear distribution of Jmjd6, the structure of Jmjd6 oligomers in vitro changes in the absence of the polyS domain, possibly reflecting the role of the polyS domain in nuclear/nucleolar shuttling of Jmjd6.
First Report of Artichoke yellow ringspot virus in Globe Artichoke in Turkey
Authors: Paylan I. C. , Ergun M. , Erkan S. 
Published: May 2013

Turkey is one of the main globe artichoke (Cynara cardunculus L. subsp. scolymus (L.) Hayek) producers in the world. Cultivation of this crop is done mainly in the Aegean and Eastern Marmara regions with asexually propagated cultivars such as Bayrampasa and Sakiz. More than half of total globe artichoke production in Turkey is obtained from the provinces of Izmir, Aydin, and Mugla in the Aegean region. Surveys in 2011 and 2012 were carried out to look for the presence of Artichoke yellow ringspot virus (AYRSV), Tobacco mosaic virus (TMV), and Tomato spotted wilt virus (TSWV) in the globe artichoke production areas in these three provinces. Double antibody sandwich (DAS)-ELISA and reverse transcriptase (RT)-PCR assays conducted for TMV and TSWV showed that the samples were not infected with these two viruses. Due to the lack of commercial ELISA kits against AYRSV, RT-PCR and biological indexing were used for its identification. Leaf tissues from 35 symptomatic and 25 symptomless plants were sampled and analyzed by RT-PCR using as template total RNAs extracted by a silica gel method (1). RT-PCR was conducted as previously reported (1). A PCR product of the expected size (about 530 bp) was obtained from five plant samples that were collected from Izmir province and had symptoms of bright yellow spots and line patterns on the leaves. The incidence of diseased plants in the fields ranged from 1 to 5%. In previously conducted studies, these symptoms were defined as typical symptoms of AYRSV on artichokes (2,3,4). One of the PCR products was cloned and sequenced. BLASTn analysis of the obtained sequence (GenBank Accession No. KC622054) showed 92% nucleotide identity with the partial RNA1 sequence of an AYRSV isolate from Allium cepa (AM087671.2). Furthermore, selected test plants were mechanically inoculated with sap from plant samples that were positive in RT-PCR. Chlorotic local lesions and systemic mottling symptoms were observed on Chenopodium quinoa; chlorotic lesions, mosaic, and deformation on Cucumis sativus; and systemic mosaic, reddish necrotic local lesions, and malformation on Phaseolus vulgaris (French bean). Results of the biological tests were confirmed by RT-PCR. AYRSV has a wide host range including artichoke and six other cultivated plant species and can be easily transmitted by seed, plant sap, and vegetative propagation (3). To our knowledge, this is the first report of natural infection of globe artichoke by AYRSV in Turkey. AYRSV infections can have a detrimental effect on the growth and yield of artichoke plantings. This assay will be useful for further epidemiological studies. References: (1) X. Foissac et al. Acta Hortic. 550:37, 2001. (2) D. Galliitelli et al. Adv. Virus Res. 84:289, 2012. (3) P. E. Kyriakopoulou et al. Ann. Inst. Phytopathol. Benaki 14:139, 1985. (4) V. I. Maliogka et al. Phytopathology 96:622, 2006.
Comprehensive Dissection of Spatiotemporal Metabolic Shifts in Primary, Secondary, and Lipid Metabolism during Developmental Senescence in Arabidopsis
Authors: Watanabe Mutsumi , Balazadeh Salma , Tohge Takayuki , Erban Alexander , Giavalisco Patrick , Kopka Joachim , Mueller-Roeber Bernd , Fernie Alisdair R. , Hoefgen Rainer 
Published: May 2013

AbstractDevelopmental senescence is a coordinated physiological process in plants and is critical for nutrient redistribution from senescing leaves to newly formed sink organs, including young leaves and developing seeds. Progress has been made concerning the genes involved and the regulatory networks controlling senescence. The resulting complex metabolome changes during senescence have not been investigated in detail yet. Therefore, we conducted a comprehensive profiling of metabolites, including pigments, lipids, sugars, amino acids, organic acids, nutrient ions, and secondary metabolites, and determined approximately 260 metabolites at distinct stages in leaves and siliques during senescence in Arabidopsis (Arabidopsis thaliana). This provided an extensive catalog of metabolites and their spatiotemporal cobehavior with progressing senescence. Comparison with silique data provides clues to source-sink relations. Furthermore, we analyzed the metabolite distribution within single leaves along the basipetal sink-source transition trajectory during senescence. Ceramides, lysolipids, aromatic amino acids, branched chain amino acids, and stress-induced amino acids accumulated, and an imbalance of asparagine/aspartate, glutamate/glutamine, and nutrient ions in the tip region of leaves was detected. Furthermore, the spatiotemporal distribution of tricarboxylic acid cycle intermediates was already changed in the presenescent leaves, and glucosinolates, raffinose, and galactinol accumulated in the base region of leaves with preceding senescence. These results are discussed in the context of current models of the metabolic shifts occurring during developmental and environmentally induced senescence. As senescence processes are correlated to crop yield, the metabolome data and the approach provided here can serve as a blueprint for the analysis of traits and conditions linking crop yield and senescence.
Abnormal Glycosphingolipid Mannosylation Triggers Salicylic Acid–Mediated Responses inArabidopsis
Authors: Mortimer Jenny C. , Yu Xiaolan , Albrecht Sandra , Sicilia Francesca , Huichalaf Mariela , Ampuero Diego , Michaelson Louise V. , Murphy Alex M. , Matsunaga Toshiro , Kurz Samantha , Stephens Elaine , Baldwin Timothy C. , Ishii Tadashi , Napier Johnathan A. , Weber Andreas P.M. , Handford Michael G. , Dupree Paul 
Published: May 2013

AbstractThe Arabidopsis thaliana protein GOLGI-LOCALIZED NUCLEOTIDE SUGAR TRANSPORTER (GONST1) has been previously identified as a GDP-d-mannose transporter. It has been hypothesized that GONST1 provides precursors for the synthesis of cell wall polysaccharides, such as glucomannan. Here, we show that in vitro GONST1 can transport all four plant GDP-sugars. However, gonst1 mutants have no reduction in glucomannan quantity and show no detectable alterations in other cell wall polysaccharides. By contrast, we show that a class of glycosylated sphingolipids (glycosylinositol phosphoceramides [GIPCs]) contains Man and that this mannosylation is affected in gonst1. GONST1 therefore is a Golgi GDP-sugar transporter that specifically supplies GDP-Man to the Golgi lumen for GIPC synthesis. gonst1 plants have a dwarfed phenotype and a constitutive hypersensitive response with elevated salicylic acid levels. This suggests an unexpected role for GIPC sugar decorations in sphingolipid function and plant defense signaling. Additionally, we discuss these data in the context of substrate channeling within the Golgi.