bluuebunny/crossref_metadata_2025 huggingface dataset:
Warming differentially influences the effects of drought on stoichiometry and metabolomics in shoots and roots
Authors: Gargallo‐Garriga Albert , Sardans Jordi , Pérez‐Trujillo Míriam , Oravec Michal , Urban Otmar , Jentsch Anke , Kreyling Juergen , Beierkuhnlein Carl , Parella Teodor , Peñuelas Josep
Published: March 2015

Plants in natural environments are increasingly being subjected to a combination of abiotic stresses, such as drought and warming, in many regions. The effects of each stress and the combination of stresses on the functioning of shoots and roots have been studied extensively, but little is known about the simultaneous metabolome responses of the different organs of the plant to different stresses acting at once.

We studied the shift in metabolism and elemental composition of shoots and roots of two perennial grasses, Holcus lanatus and Alopecurus pratensis, in response to simultaneous drought and warming.

These species responded differently to individual and simultaneous stresses. These responses were even opposite in roots and shoots. In plants exposed to simultaneous drought and warming, terpenes, catechin and indole acetic acid accumulated in shoots, whereas amino acids, quinic acid, nitrogenous bases, the osmoprotectants choline and glycine betaine, and elements involved in growth (nitrogen, phosphorus and potassium) accumulated in roots. Under drought, warming further increased the allocation of primary metabolic activity to roots and changed the composition of secondary metabolites in shoots.

These results highlight the plasticity of plant metabolomes and stoichiometry, and the different complementary responses of shoots and roots to complex environmental conditions.
Impaired movement timing in neurological disorders: rehabilitation and treatment strategies
Authors: Hove Michael J. , Keller Peter E.
Published: March 2015

Timing abnormalities have been reported in many neurological disorders, including Parkinson's disease (PD). In PD, motor‐timing impairments are especially debilitating in gait. Despite impaired audiomotor synchronization, PD patients’ gait improves when they walk with an auditory metronome or with music. Building on that research, we make recommendations for optimizing sensory cues to improve the efficacy of rhythmic cuing in gait rehabilitation. Adaptive rhythmic metronomes (that synchronize with the patient's walking) might be especially effective. In a recent study we showed that adaptive metronomes synchronized consistently with PD patients’ footsteps without requiring attention; this improved stability and reinstated healthy gait dynamics. Other strategies could help optimize sensory cues for gait rehabilitation. Groove music strongly engages the motor system and induces movement; bass‐frequency tones are associated with movement and provide strong timing cues. Thus, groove and bass‐frequency pulses could deliver potent rhythmic cues. These strategies capitalize on the close neural connections between auditory and motor networks; and auditory cues are typically preferred. However, moving visual cues greatly improve visuomotor synchronization and could warrant examination in gait rehabilitation. Together, a treatment approach that employs groove, auditory, bass‐frequency, and adaptive (GABA) cues could help optimize rhythmic sensory cues for treating motor and timing deficits.
Musical tasks targeting preserved and impaired functions in two dementias
Authors: Halpern Andrea R. , Golden Hannah L. , Magdalinou Nadia , Witoonpanich Pirada , Warren Jason D.
Published: March 2015

Studies of musical abilities in dementia have for the most part been rather general assessments of abilities, for instance, assessing retention of music learned premorbidly. Here, we studied patients with dementias with contrasting cognitive profiles to explore specific aspects of music cognition under challenge. Patients suffered from Alzheimer's disease (AD), in which a primary impairment is in forming new declarative memories, or Lewy body disease (PD/LBD), a type of parkinsonism in which executive impairments are prominent. In the AD patients, we examined musical imagery. Behavioral and neural evidence confirms involvement of perceptual networks in imagery, and these are relatively spared in early stages of the illness. Thus, we expected patients to have relatively intact imagery in a mental pitch comparison task. For the LBD patients, we tested whether executive dysfunction would extend to music. We probed inhibitory skills by asking for a speeded pitch or timbre judgment when the irrelevant dimension was held constant or also changed. Preliminary results show that AD patients score similarly to controls in the imagery tasks, but PD/LBD patients are impaired relative to controls in suppressing some irrelevant musical dimensions, particularly when the required judgment varies from trial to trial.
Musical affect regulation in infancy
Authors: Trehub Sandra E. , Ghazban Niusha , Corbeil Mariève
Published: March 2015

Adolescents and adults commonly use music for various forms of affect regulation, including relaxation, revitalization, distraction, and elicitation of pleasant memories. Mothers throughout the world also sing to their infants, with affect regulation as the principal goal. To date, the study of maternal singing has focused largely on its acoustic features and its consequences for infant attention. We describe recent laboratory research that explores the consequences of singing for infant affect regulation. Such work reveals that listening to recordings of play songs can maintain 6‐ to 9‐month‐old infants in a relatively contented or neutral state considerably longer than recordings of infant‐directed or adult‐directed speech. When 10‐month‐old infants fuss or cry and are highly aroused, mothers’ multimodal singing is more effective than maternal speech at inducing recovery from such distress. Moreover, play songs are more effective than lullabies at reducing arousal in Western infants. We explore the implications of these findings along with possible practical applications.
Music training and speech perception: a gene–environment interaction
Authors: Schellenberg E. Glenn
Published: March 2015

Claims of beneficial side effects of music training are made for many different abilities, including verbal and visuospatial abilities, executive functions, working memory, IQ, and speech perception in particular. Such claims assume that music training causes the associations even though children who take music lessons are likely to differ from other children in music aptitude, which is associated with many aspects of speech perception. Music training in childhood is also associated with cognitive, personality, and demographic variables, and it is well established that IQ and personality are determined largely by genetics. Recent evidence also indicates that the role of genetics in music aptitude and music achievement is much larger than previously thought. In short, music training is an ideal model for the study of gene–environment interactions but far less appropriate as a model for the study of plasticity. Children seek out environments, including those with music lessons, that are consistent with their predispositions; such environments exaggerate preexisting individual differences.
Neuronal oscillations as a mechanistic substrate of auditory temporal prediction
Authors: Morillon Benjamin , Schroeder Charles E.
Published: March 2015

Neuronal oscillations are comprised of rhythmic fluctuations of excitability that are synchronized in ensembles of neurons and thus function as temporal filters that dynamically organize sensory processing. When perception relies on anticipatory mechanisms, ongoing oscillations also provide a neurophysiological substrate for temporal prediction. In this article, we review evidence for this account with a focus on auditory perception. We argue that such “oscillatory temporal predictions” can selectively amplify neuronal sensitivity to inputs that occur in a predicted, task‐relevant rhythm and optimize temporal selection. We elaborate this argument for a prototypic example, speech processing, where information is present at multiple time scales, with delta, theta, and low‐gamma oscillations being specifically and simultaneously engaged, enabling multiplexing. We then consider the origin of temporal predictions, specifically the idea that the motor system is involved in the generation of such prior information. Finally, we place temporal predictions in the general context of internal models, discussing how they interact with feature‐based or spatial predictions. We propose that complementary predictions interact synergistically according to a dominance hierarchy, shaping perception in the form of a multidimensional filter mechanism.
Emergence of biological markers of musicianship with school‐based music instruction
Authors: Kraus Nina , Strait Dana L.
Published: March 2015

Musician children and adults demonstrate biological distinctions in auditory processing relative to nonmusicians. For example, musician children and adults have more robust neural encoding of speech harmonics, more adaptive sound processing, and more precise neural encoding of acoustically similar sounds; these enhancements may contribute to musicians’ linguistic advantages, such as for hearing speech in noise and reading. Such findings have inspired proposals that the auditory and cognitive stimulation induced by musical practice renders musicians enhanced according to biological metrics germane to communication. Cross‐sectional methodologies comparing musicians with nonmusicians, however, are limited by the inability to disentangle training‐related effects from demographic and innate qualities that may predistinguish musicians. Over the past several years, our laboratory has addressed this problem by examining the emergence of neural markers of musicianship in children and adolescents using longitudinal approaches to track the development of biological indices of speech processing. This work was conducted in partnership with successful community‐based music programs, thus avoiding reliance on a synthetic program for the purposes of laboratory study. Outcomes indicate that many of musicians’ auditory‐related biological enhancements emerge with training and may promote the acquisition of language skills, including in at‐risk populations.
Dance experience sculpts aesthetic perception and related brain circuits
Authors: Kirsch Louise P. , Dawson Kelvin , Cross Emily S.
Published: March 2015

Previous research on aesthetic preferences demonstrates that people are more likely to judge a stimulus as pleasing if it is familiar. Although general familiarity and liking are related, it is less clear how motor familiarity, or embodiment, relates to a viewer's aesthetic appraisal. This study directly compared how learning to embody an action impacts the neural response when watching and aesthetically evaluating the same action. Twenty‐two participants trained for 4 days on dance sequences. Each day they physically rehearsed one set of sequences, passively watched a second set, listened to the music of a third set, and a fourth set remained untrained. Functional MRI was obtained prior to and immediately following the training period, as were affective and physical ability ratings for each dance sequence. This approach enabled precise comparison of self‐report methods of embodiment with nonbiased, empirical measures of action performance. Results suggest that after experience, participants most enjoy watching those dance sequences they danced or observed. Moreover, brain regions involved in mediating the aesthetic response shift from subcortical regions associated with dopaminergic reward processing to posterior temporal regions involved in processing multisensory integration, emotion, and biological motion.
Short‐ and long‐term rhythmic interventions: perspectives for language rehabilitation
Authors: Schön Daniele , Tillmann Barbara
Published: March 2015

This paper brings together different perspectives on the investigation and understanding of temporal processing and temporal expectations. We aim to bridge different temporal deficit hypotheses in dyslexia, dysphasia, or deafness in a larger framework, taking into account multiple nested temporal scales. We present data testing the hypothesis that temporal attention can be influenced by external rhythmic auditory stimulation (i.e., musical rhythm) and benefits subsequent language processing, including syntax processing and speech production. We also present data testing the hypothesis that phonological awareness can be influenced by several months of musical training and, more particularly, rhythmic training, which in turn improves reading skills. Together, our data support the hypothesis of a causal role of rhythm‐based processing for language processing and acquisition. These results open new avenues for music‐based remediation of language and hearing impairment.
Alignment strategies for the entrainment of music and movement rhythms
Authors: Moens Bart , Leman Marc
Published: March 2015

Theories of entrainment assume that spontaneous entrainment emerges from dynamic laws that operate via mediators on interactions, whereby entrainment is facilitated if certain conditions are fulfilled. In this study, we show that mediators can be built that affect the entrainment of human locomotion to music. More specifically, we built D‐Jogger, a music player that functions as a mediator between music and locomotion rhythms. The D‐Jogger makes it possible to manipulate the timing differences between salient moments of the rhythms (beats and footfalls) through the manipulation of the musical period and phase, which affect the condition in which entrainment functions. We conducted several experiments to explore different strategies for manipulating the entrainment of locomotion and music. The results of these experiments showed that spontaneous entrainment can be manipulated, thereby suggesting different strategies on how to embark. The findings furthermore suggest a distinction among different modalities of entrainment: finding the beat (the most difficult part of entrainment), keeping the beat (easier, as a temporal scheme has been established), and being in phase (no entrainment is needed because the music is always adapted to the human rhythm). This study points to a new avenue of research on entrainment and opens new perspectives for the neuroscience of music.
NICU music therapy: song of kin as critical lullaby in research and practice
Authors: Loewy Joanne
Published: March 2015

Music therapy can improve neonatal function and reduce anxiety in parents during neonatal intensive care unit (NICU) stays. Live music entrained to an infant's observed vital signs, provided by a certified music therapist with First Sounds RBL (rhythm, breath, and lullaby) training, enhanced bonding for infant–parent dyads and triads. The author's song of kin intervention, which employs parent‐selected songs, is compared to the presentation of a well‐known folk theme (“Twinkle”) in 272 neonates. Culturally based, parent‐selected, personalized musical tunes provided in song, as a noninvasive intervention, foster optimal, continuous quality of care. Music psychotherapy sessions for parents before working with their infants can instill a potent means of nonconfrontational support, allowing for expression of fear or anxiety related to the premature birth. Although most attention is typically directed to their infant, using music can support the parents’ grief and assist in the expression of hope that can instill a sense of security and containment. From the NICU to home, a familiar thread‐line theme can be resourced directly from the family and/or parent and applied effortlessly throughout the growing baby's transitional moments.
Sound‐induced stabilization of breathing and moving
Authors: Bardy Benoît G. , Hoffmann Charles P. , Moens Bart , Leman Marc , Dalla Bella Simone
Published: March 2015

In humans and other animals, the locomotor and respiratory systems are coupled together through mechanical, neurophysiological, and informational interactions. At a macroscopic observer–environment level, these three types of interactions produce locomotor–respiratory coupling (LRC), whose dynamics are evaluated in this paper. A formal analysis of LRC is presented, exploiting tools from synchronization theories and nonlinear dynamics. The results of two recent studies, in which participants were instructed to cycle or exhale at a natural frequency or in synchrony with an external rhythmic sound, are discussed. The metronome was either absent or present (study 1) and close to or far from the natural frequency of the cycling and breathing systems (study 2). The results evidenced a stabilization of cycling, breathing, and LRC when sound was present compared to when it was absent. A decrease in oxygen consumption was also observed, accompanying the increase in sound‐induced LRC stabilization. These results obtained with a simple rhythmic metronome beat have consequences for exercising while listening to music; the consequences are further explored here.
Can rhythmic auditory cuing remediate language‐related deficits in Parkinson's disease?
Authors: Kotz Sonja A. , Gunter Thomas C.
Published: March 2015

Neurodegenerative changes of the basal ganglia in idiopathic Parkinson's disease (IPD) lead to motor deficits as well as general cognitive decline. Given these impairments, the question arises as to whether motor and nonmotor deficits can be ameliorated similarly. We reason that a domain‐general sensorimotor circuit involved in temporal processing may support the remediation of such deficits. Following findings that auditory cuing benefits gait kinematics, we explored whether reported language‐processing deficits in IPD can also be remediated via auditory cuing. During continuous EEG measurement, an individual diagnosed with IPD heard two types of temporally predictable but metrically different auditory beat‐based cues: a march, which metrically aligned with the speech accent structure, a waltz that did not metrically align, or no cue before listening to naturally spoken sentences that were either grammatically well formed or were semantically or syntactically incorrect. Results confirmed that only the cuing with a march led to improved computation of syntactic and semantic information. We infer that a marching rhythm may lead to a stronger engagement of the cerebello–thalamo–cortical circuit that compensates dysfunctional striato–cortical timing. Reinforcing temporal realignment, in turn, may lead to the timely processing of linguistic information embedded in the temporally variable speech signal.
Perspectives on the rhythm–grammar link and its implications for typical and atypical language development
Authors: Gordon Reyna L. , Jacobs Magdalene S. , Schuele C. Melanie , McAuley J. Devin
Published: March 2015

This paper reviews the mounting evidence for shared cognitive mechanisms and neural resources for rhythm and grammar. Evidence for a role of rhythm skills in language development and language comprehension is reviewed here in three lines of research: (1) behavioral and brain data from adults and children, showing that prosody and other aspects of timing of sentences influence online morpho‐syntactic processing; (2) comorbidity of impaired rhythm with grammatical deficits in children with language impairment; and (3) our recent work showing a strong positive association between rhythm perception skills and expressive grammatical skills in young school‐age children with typical development. Our preliminary follow‐up study presented here revealed that musical rhythm perception predicted variance in 6‐year‐old children's production of complex syntax, as well as online reorganization of grammatical information (transformation); these data provide an additional perspective on the hierarchical relations potentially shared by rhythm and grammar. A theoretical framework for shared cognitive resources for the role of rhythm in perceiving and learning grammatical structure is elaborated on in light of potential implications for using rhythm‐emphasized musical training to improve language skills in children.
Motor responses to a steady beat
Authors: Schaefer Rebecca S. , Overy Katie
Published: March 2015

It is increasingly well established that music containing an isochronous pulse elicits motor responses at the levels of both brain and behavior. Such motor responses are often used in pedagogical and clinical practice to induce movement, particularly where motor functions are impaired. However, the complex nature of such apparently universal human responses has, arguably, not received adequate research attention to date. In particular, it should be noted that many adults, including those with disabilities, find it somewhat difficult to synchronize their movements with a beat with perfect accuracy; indeed, perfecting the skill of being musically “in time” can take years of training during childhood. Further research is needed on the nature of both the specificity and range of motor responses that can arise from the perception of a steady auditory pulse, with different populations, musical stimuli, conditions, and required levels of accuracy in order to better understand and capture the potential value of the musical beat as a pedagogical and therapeutic tool.
SCRUTINIZE ME, PLEASE! THE DRIVERS, MANIFESTATIONS AND IMPLICATIONS OF ACCOUNTABILITY‐SEEKING BEHAVIOUR
Authors: KARSTEN NIELS
Published: March 2015

Voluntary accountability, where people and organizations willingly subject themselves to scrutiny, seems counterintuitive. The common understanding is that increased accountability has negative consequences for the accountor; and so why would anyone voluntarily seek accountability when it is not required? Current explanations hold that external pressures can explain accountability‐seeking behaviour, and the proponents are not convinced by the argument that it is beneficial to the accountor. In contrast, this study finds that accountability often serves the accountor's interests. A six‐part typology of accountor‐beneficial motivations is developed, the empirical adequacy of which is tested through extensive case studies. The results show that public accountability can be a means rather than a burden in the hands of political executive leaders. These findings challenge the conventional principal–agent understanding of accountability and suggest that the study of the poorly understood practice of democratic accountability would benefit from a more leader‐centric perspective.
Locating Control Points In Aerial Images With A Multi‐Scale Approach Based On Terrestrial Image Patches
Authors: Berveglieri Adilson , Tommaselli Antonio M. G.
Published: March 2015

The objective of the proposed approach is to locate and measure ground control points in aerial images when large image search spaces are defined due to the use of inaccurate initial exterior orientation parameters, such as those provided by consumer‐grade navigation systems. Vertical terrestrial image patches covering control point areas are generated and compared with aerial patches using feature‐ and area‐based matching algorithms to automatically determine their corresponding positions in aerial images with sub‐pixel precision. The approach is based on techniques for both image search space reduction and adaptive least squares matching. Experiments with real data were performed with bundle block triangulation and the results were analysed using control and check points in both object and image spaces. The proposed technique enabled a significant reduction in the search space within which it was feasible to successfully locate control points. Compared with manual measurements, the results obtained by the automatic technique were more accurate, achieving one‐fifth of the ground sample distance in planimetric check point discrepancies.
Plant pathogenic bacteria in open irrigation systems: what risk for crop health?
Authors: Lamichhane J. R. , Bartoli C.
Published: March 2015

The current global area equipped for irrigation provides 30–40% of the world's gross food output. Water used for plant irrigation may harbour plant pathogens and foster their spread. This represents a serious risk for crop health, with heavy socio‐economic consequences. More specifically to plant pathogenic bacteria (PPB), a range of species have been reported from irrigation systems and their potential role in epidemic development has long been recognized. However, only a few studies have been performed to date on the ecology of PPB in the context of water habitats. Consequently, current knowledge of the biology, ecology and epidemiology of PPB in irrigation water is poor. In light of this, an attempt is made to describe the most relevant information concerning the role of open irrigation systems in the survival and dissemination of PPB throughout the range of cultivations and the possible consequences for crop health. The information described in this paper will help to improve understanding on the overlooked role of irrigation water as a reservoir of PPB.
Exporting and Productivity: The Effects of Multi‐Product and Multi‐Market Export Entry
Authors: Masso Jaan , Vahter Priit
Published: March 2015

Empirical studies on the micro‐level effects of exporting on productivity pay usually little attention to the potentially heterogeneous effects of the different modes of export market entry. We show that multi‐product export entry is associated with higher post‐entry productivity compared to other firms. This can imply significant benefits from experimentation with different products. Our analysis is based on detailed export data from full population of firms in Estonia, disaggregated for each firm by export markets and individual products.
Impact‐induced muscle damage and urinary pterins in professional rugby: 7,8‐dihydroneopterin oxidation by myoglobin
Authors: Lindsay A. , Healy J. , Mills W. , Lewis J. , Gill N. , Draper N. , Gieseg S. P.
Published: March 2015

Muscle damage caused through impacts in rugby union is known to increase oxidative stress and inflammation. Pterins have been used clinically as markers of oxidative stress, inflammation, and neurotransmitter synthesis. This study investigates the release of myoglobin from muscle tissue due to force‐related impacts and how it is related to the subsequent oxidation of 7,8‐dihydroneopterin to specific pterins. Effects of iron and myoglobin on 7,8‐dihydroneopterin oxidation were examined in vitro via strong cation‐exchange high‐performance liquid chromatography (SCX‐HPLC) analysis of neopterin, xanthopterin, and 7,8‐dihydroxanthopterin. Urine samples were collected from 25 professional rugby players pre and post four games and analyzed for myoglobin by enzyme‐linked immunosorbent assay, and 7,8‐dihydroneopterin oxidation products by HPLC. Iron and myoglobin oxidized 7,8‐dihydroneopterin to neopterin, xanthopterin, and 7,8‐dihydroxanthopterin at concentrations at or above 10 μM and 50 μg/mL, respectively. All four games showed significant increases in myoglobin, neopterin, total neopterin, biopterin, and total biopterin, which correlated between each variable (P < 0.05). Myoglobin and iron facilitate 7,8‐dihydroneopterin oxidation to neopterin and xanthopterin. In vivo delocalization of myoglobin due to muscle damage may contribute to oxidative stress and inflammation after rugby. Increased concentrations of biopterin and total biopterin may indicate production of nitric oxide and monoamine neurotransmitters in response to the physical stress.
Different Approaches, Different Results in Small State Studies: Complementary Views on the Monarchy and Traditional Governance in Liechtenstein
Authors: Wolf Sebastian
Published: March 2015

The research note comments on W. Veenendaal's article “A Big Prince in a Tiny Realm: Smallness, Monarchy, and Political Legitimacy in the Principality of Liechtenstein”. It is argued, inter alia, that the phenomenon of “princely self‐restraint” should not be underestimated in Liechtenstein's constitutional reality. The character of the microstate's actual political system strongly depends on the individual personality of the Reigning Prince. A strong monarch who acts as a political actor with his own agenda should not be conceptualized as a neutral traditional leader. From the perspective of many citizens of Liechtenstein, the principality's political system is legitimate since it combines traditional authority and legal‐rational authority in a unique way. Largely due to the powerful role of the government, the microstate is characterized by consensus‐oriented hierarchical governance. Elite surveys can be seen as a useful instrument to overcome some of the methodological pitfalls of the elite interview approach.
Combining tape stripping and non‐invasive reflectance confocal microscopy : an in vivo model to study skin damage
Authors: Peppelman M. , van den Eijnde W. A. J. , Jaspers E. J. , Gerritsen M‐J. P. , van Erp P. E. J.
Published: March 2015

Background

Evaluation of (immuno)histological and cell biological changes in damaged skin requires often an invasive skin biopsy, making in vivo models inappropriate to study skin damage. Reflectance confocal microscopy (RCM) might overcome this limitation. Therefore, we evaluated the use of a tape‐stripping model in combination with RCM to provide morphological data on skin damage and recovery.

Methods

In 25 volunteers, a tape‐stripping stimulus was applied. The skin was imaged with RCM during 1 week and 3 mm punch biopsies were obtained.

Results

Strong correlations between epidermal thickness determined by RCM and conventional histological measurements were found. RCM thickness measurements correlated well with epidermal proliferation. The 10× or 15× repeated tape‐stripping resulted in skin damage similar to acute stripping. Mild repeated tape‐stripping showed no skin damage.

Conclusion

Overall, we demonstrated that non‐invasive RCM in combination with tape‐stripping could be used as model to obtain morphological and cell biological data on skin‐material interactions.
Menthol concentration in topical cold gel does not have significant effect on skin cooling
Authors: Lasanen R. , Julkunen P. , Airaksinen O. , Töyräs J.
Published: March 2015

Background

Topical menthol gels are used in the treatment of various pain conditions. However, the effect of the menthol concentration to skin cooling or cooling sensation is not clear. We hypothesized that increasing menthol concentration enhances skin cooling and causes elevated cooling sensation.

Methods

Ten healthy male volunteers (age range 25–30 years) were recruited for this study. Application of three gels with different menthol concentrations (0.5%, 4.6% and 10.0%) was tested in random sequence on the left thigh of the subjects. Skin cooling was recorded with a digital infrared camera (FLIR Systems Inc., USA), and cooling sensation was measured with the visual analogue scale rating.

Results

All gels decreased skin temperature significantly (P < 0.05) at least for one hour. However, the variation in menthol concentration seemed not to have a significant effect on skin cooling. Subjects experienced that gel with 4.6% menthol concentration caused significantly stronger cooling effect than 0.5% and 10.0% gels. Gel application had no significant effect on skin temperature in surrounding skin areas.

Conclusion

In contrast to our hypothesis, menthol concentration was not connected to skin cooling, while moderate menthol concentration of 4.6% may induce stronger cooling sensation compared to low (0.5%) or high (10.0%) concentration gels.
Symmetric Merge and Local Instability: Evidence from Split Topics
Authors: Ott Dennis
Published: March 2015

In this paper, I argue against the standard analysis of so‐called split topics in German as discontinuous noun phrases (van Riemsdijk 1989). Building in part on Fanselow 1988, I show that the construction rather involves two morphosyntactically autonomous nominal constituents that are predicatively related in underlying form. This predication is syntactically unstable, however. Merge of twoXPs within a single argument or adjunct position yields a symmetric structure for which no label (“head”) can be detected by Minimal Search (“for any syntactic object {α,β},αis the head if α is a lexical item”; see Chomsky 2008). Therefore, one of the two noun phrases must move at the phase level in order to render the structure asymmetric; in case the stranded noun phrase is elliptical, the impression of a discontinuous constituent arises. By providing a principled explanation for split topicalization in these terms, the analysis furnishes evidence for an architecture in which Merge applies freely (pacerecent claims to the contrary, e.g., in Kayne 2010), and as an asymmetrizing device when applying internally (as movement), in the spirit of Moro 2000 and Chomsky 2013.
Biomathematical Conferences and Schools for Young Scientists at the Bulgarian Academy of Sciences
Authors: Anguelov Roumen , Markov Svetoslav
Published: March 2015

This is a brief report on some international meetings В in the field of biomathematics and scientific computations organized within the frames of the В Bulgarian Academy of Sciences. Most В meetings involved both a scientific conference and a School for Young Scientists aiming to attract doctoral students and young scientists and to promote the В  В integration between learning and research activities.
On the Numerical Computation of Enzyme Kinetic Parameters
Authors: Dimitrov Stanko , Velikova Gergana , Beschkov Venko , Markov Svetoslav
Published: March 2015

We consider the enzyme kinetic reaction scheme originally proposed by V. HenriВ  of single enzyme-substrate dynamics where two fractions of the enzyme - free and bound - are involved. Henri's scheme involves four concentrations and three rate constants and via the mass action law it is translated into a systemВ  of four ODE's. On two case studies we demonstrate how the rate constants can be computed whenever time course experimental data are available. The obtained results are compared with analogous results implied by classical Michaelis-Menten model. Our approach focuses on the uncertainties in the experimental data, as well as on the use of contemporary computational tools such as CAS Mathematica.
Sigmoidal Functions: Some Computational and Modelling Aspects
Authors: Kyurkchiev Nikolay , Markov Svetoslav
Published: March 2015

We В focus on some computational, modelling and approximation issues related to the logistic sigmoidal function and to Heaviside step function. В  The Hausdorff approximation of the Heaviside interval step function by sigmoidal functions is discussed from various computational and modelling aspects. Some relations between Verhulst model and certain biochemical reaction equations are discussed and analyzed. Numerical examples are presented using CAS Mathematica.
Development of an Oil and Gas Refinery Inspection Robot
Authors: Steele John P. H. , Han Qi , Karki Hamad , Al-Wahedi Khaled , Ayoade Adewole A. , Sweatt Marshall R. , Albert Daniel P. , Yearsley W. Alex
Published: March 2015

Oil and gas refineries present challenging environments in which to work and operate, especially in places like the Middle East where temperatures can reach 50 °C and sand storms which can reduce visibility to a few meters. In addition, there can be gas or steam leaks which present health and safety hazards to the workers. At present, continuous operation of these plants requires that human workers venture out into these conditions in order to observe and report on the conditions within the plant. The goal of this work is to design, fabricate, assemble, and test an inspection robot in an effort to reduce the exposure and risks to human operators while increasing the flexibility and range of remote observations provided by a mobile robot.

In this paper, we will report on the design approach taken, the subsystems identified and developed, the software environment chosen, and the application tasks envisioned. We will also report on the challenges of developing a robust localization algorithm for use in the challenging environment of a refinery as well as the needs for robust wireless communications in order to maintain command and control from the operators control room. An overview of the five-degree-of-freedom arm designed and fabricated, and its real-time control will also be presented. Results from GPS navigation and localization experiments will be presented. While average errors during parked operations were often less than one meter for the WAAS enabled GPS system, locational errors during dynamic operations were often more than three meters. This is due to multi-path signals near building structures and piping infrastructure. Real-time arm control has been implemented using FPGAs and while tuning presented some challenge, the FPGA has provided smooth and repeatable operation. Sensors include gas detectors, acoustic sensors, thermal imaging, and video camera streaming. In addition, we will report on a multi-faceted approach to localization using three different sensor technologies and integrated using a Kalman filter.
Optimization Design for Normal Direction Measurement in Robotic Drilling
Authors: Gao Y. , Wu D. , Nan C. , Ma X. , Chen K.
Published: March 2015

In large assemblies, the perpendicularity of a bolting hole has remarkable effects on the fatigue life and fluid dynamic configuration. While the Computer Aided Design (CAD) model of complexly curved workpieces is hardly satisfied because of manufacturing errors, it is very necessary to measure the normal direction in robotic drilling. One advisable approach is to arrange four laser displacement sensors at the vertices of a rhombus whose center aims at the drilling position. The influencing factors of the measurement precision are firstly discussed in this study, and a novel method to optimize the arrangement size of the displacement sensors for higher precision is introduced. The measurement error for the normal direction consists of the principle error and instrumental error, caused by inconstant curvature of the surfaces and distance measuring errors of instruments, respectively. When the displacement sensors are arranged closer to each other, the principle error will be decreased, whereas the instrumental error will be increased. After the curvature feature of the surface is obtained with the introduced method, the graph of the measurement precision and the arrangement size is plotted. Then, the graph can contribute to developing an optimized design of arrangement size for higher precision. Finally, an example of the curvature obtainment and the arrangement optimization is given. The experimental results show that the optimized design has achieved a higher precision of ± 0.17° for αY and ± 0.26° for αX, whereas the precision of another design is about ± 0.21° for αY and ± 0.29° for αX. The proposed optimization method will bring greater benefit for complexly curved surfaces in practical products and it offers a chance to optimize the arrangement during design phase with little costs.
Dynamic Analysis of a Novel Geared Infinitely Variable Transmission
Authors: Li Z. R. , Wang X. F. , Zhu W. D.
Published: March 2015

A novel geared infinitely variable transmission (IVT) that can generate a continuous output-to-input speed ratio from zero to a certain value is studied for vehicle and wind turbine applications. The principle of changing the output-to-input speed ratio is to use a crank-slider mechanism; the output-to-input speed ratio is controlled by adjusting the crank length. Since the crank-slider mechanism can lead to relatively large variation of the output-to-input speed ratio in one rotation of the crank, the instantaneous input and output speeds and accelerations have variations and the corresponding forces exerted on each part of the IVT can have obvious changes in one rotation of the crank. Since forces on some parts of the IVT are critical and can cause failure of the IVT, a dynamic analysis of the IVT is necessary to simulate the input and output speeds and accelerations. A method that combines Lagrangian dynamics and Newtonian dynamics is developed in this work to analyze the motion of the IVT. The dynamic analysis results can be used to evaluate the design of the IVT.
Nonlinear Dynamics of a Pendulum Excited by a Crank-Shaft-Slider Mechanism
Authors: Avanço Rafael H. , Navarro Hélio A. , Brasil Reyolando M. L. R. F. , Balthazar José M.
Published: March 2015

In this analysis, we consider the dynamics of a pendulum under vertical excitation of a crank-shaft-slider mechanism. The nonlinear model approaches that of a classical parametrically excited pendulum when the ratio of the length of the shaft to the radius of the crank is very large. Numerical techniques are employed to investigate the results for different parameters and initial conditions. Lyapunov exponents, bifurcation diagrams, time histories and phase portraits are presented to explore conditions when the pendulum performs or not full rotations. Of special interest are the resonance regions. Rotations together with oscillations and chaos were observed in some resonance zones.
Cost Optimization of FDM Additive Manufactured Parts
Authors: Singh Hargurdeep , Rayegani Farzad , Onwubolu Godfrey
Published: March 2015

This paper describes the experiments carried out on fused deposition modelling (FDM) machine to investigate the effects of process parameters on the cost of producing suspension arm and articulated rod. The process parameters considered include build orientation, raster width, and air gap. Using the cost estimation procedure described in this paper, the best option for part orientation, raster width, and air gap is realized which impact on the cost of manufacturing the part. Consequently, before committing to run the FDM machine, users can anticipate process parameters that will minimize manufacturing cost. However, in some cases, other objectives need be considered such as functionality since the configuration that leads to minimum cost may not necessarily result in optimum functionality.
Experimental Investigation to Study Cutting Temperature During Milling of Unidirectional Carbon Fiber Reinforced Plastic
Authors: Ghafarizadeh Seyedbehzad , Chatelain Jean-François , Lebrun Gilbert
Published: March 2015

The surface machining of Carbon Fiber Reinforced Plastics (CFRP) materials is a challenging process, given the heterogeneity and anisotropic nature of these composites, which, combined with the abrasiveness of the fibers involved, can produce some surface damage and extensive tool wear. The cutting temperature is one of the most important factors associated with the tool wear rate and machinability of these materials, which are also affected by the mechanical and thermal properties of the work material and the cutting conditions. In this work, the cutting temperature, forces and surface roughness were measured under different cutting conditions during the ball-end milling of unidirectional CFRP. Cutting speeds ranging from 200 to 350 m/min, a feed rate of 0.063 mm/rev, fiber orientation of (the angle between carbon fibers and feed direction) 0, 45, 90 and 135 degrees, and a 0.5 mm depth of cut were used. The results show that the cutting speed and fiber orientation have a significant influence on the cutting temperature and cutting force. The maximum and minimum cutting forces and temperature were achieved for fiber orientations of 90 and 0 degrees, respectively.
Analysis and Design of the 2PRU-1PRS Manipulator for Vibration Testing
Authors: Herrero Saioa , Pinto Charles , Altuzarra Oscar , Roldan-Paraponiaris Constantino
Published: March 2015

Parallel manipulators, compared to serial manipulators, have some interesting properties, such as high stiffness, low inertia, high velocity, good accuracy and large payload capacity. Thus, parallel manipulators, especially the ones with one translation and two rotations as outputs (1T2R), are being increasingly studied. The 3PRS mechanism is a very typical example of this category, but it has accuracy problems caused by the parasitic motion, and low orientation capability. To overcome these problems, new mechanisms are being studied, such as the 2PRU-1PRS manipulator. As the 3PRS manipulator, the degrees of freedom of the 2PRU-1PRS are one translation along the Z-axis and two rotations about the X- and Y-axes. The advantages are that the parasitic motion appears only in one direction instead of in three and that the orientation capability is higher. In this paper we present the design of a 2PRU-1PRS mechanism suitable for vibration tests. In order to do this, we develop a code with an intuitive GUI (graphical user interface) that, for given variable limits, solves the inverse kinematic and dynamic problem for all the variable combinations and obtains the combination that consumes less power for an harmonic trajectory. Taking the simulations results into account, we propose a design that fulfils all the requirements for vibration tests in the three axes.
Validation of Complementary Filter Based IMU Data Fusion for Tracking Torso Angle and Rifle Orientation
Authors: McGinnis Ryan S. , Cain Stephen M. , Davidson Steven P. , Vitali Rachel V. , McLean Scott G. , Perkins N. C.
Published: March 2015

Up-down and rifle aiming maneuvers are common tasks employed by soldiers and athletes. The movements underlying these tasks largely determine performance success, which motivates the need for a noninvasive and portable means for movement quantification. We answer this need by exploiting body-worn and rifle-mounted miniature inertial measurement units (IMUs) for measuring torso and rifle motions during up-down and aiming tasks. The IMUs incorporate MEMS accelerometers and angular rate gyros that measure translational acceleration and angular velocity, respectively. Both sensors enable independent estimates of the orientation of the IMU and thus, the orientation of a subject’s torso and rifle. Herein, we establish the accuracy of a complementary filter which fuses these estimates for tracking torso and rifle orientation by comparing IMU-derived and motion capture-derived (MOCAP) torso pitch angles and rifle elevation and azimuthal angles during four up-down and rifle aiming trials for each of 16 subjects (64 trials total). The up-down trials consist of five maximal effort get-down-get-up cycles (from standing to lying prone back to standing), while the rifle aiming trials consist of rapidly aiming five times at two targets 15 feet from the subject and 180 degrees apart. Results reveal that this filtering technique yields warfighter torso pitch angles that remain within 0.55 degrees of MOCAP estimates and rifle elevation and azimuthal angles that remain within 0.44 and 1.26 degrees on average, respectively, for the 64 trials analyzed. We further examine potential remaining error sources and limitations of this filtering approach. These promising results point to the future use of this technology for quantifying motion in naturalistic environments. Their use may be extended to other applications (e.g., sports training and remote health monitoring) where noninvasive, inexpensive, and accurate methods for reliable orientation estimation are similarly desired.
Development of a Variable Diameter Synthetic Jet Actuator
Authors: Albright Spencer O. , Solovitz Stephen A.
Published: March 2015

Synthetic jet actuators use oscillating motion near a fixed orifice to produce a net axial momentum flux with zero net mass flux. Through strategic application, these devices can provide flow control, propulsive thrust, and impingement cooling. To improve this performance, a new actuator has been designed with a variable orifice size, which can potentially increase exit flow speeds. The jet is generated using a pneumatic cylinder, which is oscillated linearly near an orifice. The opening consists of a camera aperture, whose diameter can decrease by a factor of 18 with the aid of a second pneumatic cylinder. The system is capable of operating at frequencies up to 5 Hz while maintaining full piston stroke, and the phase between the piston and orifice motion can be varied from 0 to 180 degrees. The flow structure is investigated using phase-locked particle image velocimetry (PIV), which shows that simultaneous constriction of the exit can substantially increase the exit speed. The initial design is used with air flow but will be extended to water applications in the future.