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Electroencephalography (EEG) coherence analysis, based on measurement of synchronous oscillations of neuronal clusters, has been used extensively to evaluate functional connectivity in brain networks. EEG coherence studies have used a variety of analysis variables (e.g., time and frequency resolutions corresponding to the analysis time period and frequency bandwidth), regions of the brain (e.g., connectivity within and between various cortical lobes and hemispheres) and experimental paradigms (e.g., resting state with eyes open or closed; performance of cognitive tasks). This variability in study designs has resulted in difficulties in comparing the findings from different studies and assimilating a comprehensive understanding of the underlying brain activity and regions with abnormal functional connectivity in a particular disorder. In order to address the variability in methods across studies and to facilitate the comparison of research findings between studies, this paper presents the structure and utilization of a comprehensive hierarchical electroencephalography (EEG) coherence analysis that allows for formal inclusion of analysis duration, EEG frequency band, cortical region, and experimental test condition in the computation of the EEG coherences. It further describes the method by which this EEG coherence analysis can be utilized to derive biomarkers related to brain (dys)function and abnormalities. In order to document the utility of this approach, the paper describes the results of the application of this method to EEG and behavioral data from a social synchrony paradigm in a small cohort of adolescents with and without Autism Spectral Disorder.

This work was funding by local grant (Clinical research funding from CHU Montpellier), CNRS RHIAPS Project and DGA (Direction Générale des Armées).; International audience; The goal of this study was to analyze the interpersonal coordination of patients suffering from schizophrenia (SZ) using a humanoid robot NAO. NAO was controlled by a neurally-inspired model that enables motions synchronization between robot and human. Using a robot has the advantage in that it can be modified and controlled without being influenced by the human with whom they are interacting. More specifically, we were interested in non-intentional interpersonal coordination which has been found in previous studies to be preserved for SZ. We performed an experiment in which we asked patients and control participants to jointly perform fitness movements with the robot which was programmed to either synchronize with the human (a bidirectional condition) or move at a fixed frequency with them (a unidirectional condition). We showed that non-intentional interpersonal coordination was preserved for SZ during Human/Robot interaction (as for human/human interaction). Also, the best synchronization, stability and the best performance in term of speed were obtained with the bidirectional condition. Our results showed that, in this specific context of an interaction at preferential frequency of subject, there were only a few differences between SZ and controls in terms of interpersonal synchronization skills. Nevertheless, we observed more variability for SZ which could partly be explained by the weaker intrapersonal coordination that they exhibited.

The elementary optical excitations in two-dimensional semiconductors hosting itinerant electrons are attractive and repulsive polarons—excitons that are dynamically screened by electrons. Exciton polarons have hitherto been studied in translationally invariant degenerate Fermi systems. Here, we show that periodic distribution of electrons breaks the excitonic translational invariance and leads to a direct optical signature in the exciton-polaron spectrum. Specifically, we demonstrate that new optical resonances appear due to spatially modulated interactions between excitons and electrons in an incompressible Mott-like correlated state. Our observations demonstrate that resonant optical spectroscopy provides an invaluable tool for studying strongly correlated states, such as Wigner crystals and density waves, where exciton-electron interactions are modified by the emergence of charge order. ISSN:2160-3308

Alternative and more intuitive input methods for the control of consumer devices (e.g. tablets, smart-phones and home automation systems), vehicle entertainment systems and industrial machines and robots are on the rise. In this contribution, we propose a body worn setup, which supplements the omnipresent 3 DoF motion sensors with a set of ultrasound transceivers. This allows for an active time–of–flight based measurement of distances between independent nodes on upper limbs and torso without requiring calibration or remote reference sensors like video cameras. A body worn demonstrator is introduced, which consists of three independent but synchronized nodes, equipped with motion sensors and Capacitive Micromachined Ultrasonic Transceivers. Results of an initial test series using eight wide arm gestures show, that combining ultrasound distance measurements and motion data improves the classification accuracy.

Wigner crystals are prime candidates for the realization of regular electron lattices under minimal requirements on external control and electronics. However, several technical challenges have prevented their detailed experimental investigation and applications to date. We propose an implementation of two-dimensional electron lattices for quantum simulation of Ising spin systems based on self-assembled Wigner crystals in transition-metal dichalcogenides. We show that these semiconductors allow for minimally invasive all-optical detection schemes of charge ordering and total spin. For incident light with optimally chosen beam parameters and polarization, we predict a strong dependence of the transmitted and reflected signals on the underlying lattice periodicity, thus revealing the charge order inherent in Wigner crystals. At the same time, the selection rules in transition-metal dichalcogenides provide direct access to the spin degree of freedom via Faraday rotation measurements., Comment: 15 pages, 12 figures

The JUICE (JUpiter ICy moon Explorer) mission is characterized by a severe environmental condition, as the spacecraft will mainly operate in the Jovian region of the solar system. Low intensity, low temperatures and high radiation doses are the challenging factors for the solar array and especially for the photovoltaic assembly. Following a technology research program [1], the $3\mathrm{G}28$ bare solar cell by Azur Space has been selected; moreover, dedicated acceptance criteria were defined to screen the devices for highest and predictable performance under the harsh Jovian condition. Leonardo has then started a pre-qualification at solar cell and protection diode assembly level (cell and diode with coverglass and interconnectors). This pre-qualification identified the technology to be finally tested in accordance to the relevant ECSS standard, specifically including also a test in low intensity low temperature (LILT) condition also for the full-scale photovoltaic assembly qualification model.

Quantum light sources in solid-state systems are of major interest as a basic ingredient for integrated quantum photonic technologies. The ability to tailor quantum emitters via site-selective defect engineering is essential for realizing scalable architectures. However, a major difficulty is that defects need to be controllably positioned within the material. Here, we overcome this challenge by controllably irradiating monolayer MoS2 using a sub-nm focused helium ion beam to deterministically create defects. Subsequent encapsulation of the ion exposed MoS2 flake with high-quality hBN reveals spectrally narrow emission lines that produce photons in the visible spectral range. Based on ab-initio calculations we interpret these emission lines as stemming from the recombination of highly localized electron–hole complexes at defect states generated by the local helium ion exposure. Our approach to deterministically write optically active defect states in a single transition metal dichalcogenide layer provides a platform for realizing exotic many-body systems, including coupled single-photon sources and interacting exciton lattices that may allow the exploration of Hubbard physics. Light emitters can be induced in transition metal dichalcogenides by defect engineering, but challenges remain in their controlled spatial positioning. Here, the authors irradiate monolayer MoS2 with a sub-nm focused helium ion beam to deterministically create defects, and obtain spectrally narrow emission lines that produce photons in the visible spectral range

he realization of mixtures of excitons and charge carriers in van der Waals materials presents a frontier for the study of the many-body physics of strongly interacting Bose-Fermi mixtures. In order to derive an effective low-energy model for such systems, we develop an exact diagonalization approach based on a discrete variable representation that predicts the scattering and bound state properties of three charges in two-dimensional transition metal dichalcogenides. From the solution of the quantum mechanical three-body problem we thus obtain the bound state energies of excitons and trions within an effective mass model which are in excellent agreement with quantum Monte Carlo predictions. The diagonalization approach also gives access to excited states of the three-body system. This allows us to predict the scattering phase shifts of electrons and excitons that serve as input for a low-energy theory of interacting mixtures of excitons and charge carriers at finite density. To this end we derive an effective exciton-electron scattering potential that is directly applicable for quantum Monte Carlo or diagrammatic many-body techniques. As an example, we demonstrate the approach by studying the many-body physics of exciton Fermi polarons in transition-metal dichalcogenides, and we show that finite-range corrections have a substantial impact on the optical absorption spectrum. Our approach can be applied to a plethora of many-body phenomena realizable in atomically thin semiconductors ranging from exciton localization to induced superconductivity., Physical Review B, 101 (19), ISSN:1098-0121, ISSN:0163-1829, ISSN:1550-235X, ISSN:0556-2805, ISSN:2469-9969, ISSN:1095-3795, ISSN:2469-9950

Functionally stable and robust interpersonal motor coordination has been found to play an integral role in the effectiveness of social interactions. However, the motion-tracking equipment required to record and objectively measure the dynamic limb and body movements during social interaction has been very costly, cumbersome, and impractical within a non-clinical or non-laboratory setting. Here we examined whether three low-cost motion-tracking options (Microsoft Kinect skeletal tracking of either one limb or whole body and a video-based pixel change method) can be employed to investigate social motor coordination. Of particular interest was the degree to which these low-cost methods of motion tracking could be used to capture and index the coordination dynamics that occurred between a child and an experimenter for three simple social motor coordination tasks in comparison to a more expensive, laboratory-grade motion-tracking system (i.e., a Polhemus Latus system). Overall, the results demonstrated that these low-cost systems cannot substitute the Polhemus system in some tasks. However, the lower-cost Microsoft Kinect skeletal tracking and video pixel change methods were successfully able to index differences in social motor coordination in tasks that involved larger-scale, naturalistic whole body movements, which can be cumbersome and expensive to record with a Polhemus. However, we found the Kinect to be particularly vulnerable to occlusion and the pixel change method to movements that cross the video frame midline. Therefore, particular care needs to be taken in choosing the motion-tracking system that is best suited for the particular research.

Past research has revealed that an individual's rhythmic limb movements become spontaneously entrained to an environmental rhythm if visual information about the rhythm is available and its frequency is near that of the individual's movements. Research has also demonstrated that if the eyes track an environmental stimulus, the spontaneous entrainment to the rhythm is strengthened. One hypothesis explaining this enhancement of spontaneous entrainment is that the limb movements and eye movements are linked through a neuromuscular coupling or synergy. Another is that eye-tracking facilitates the pick up of important coordinating information. Experiment 1 investigated the first hypothesis by evaluating whether any rhythmic movement of the eyes would facilitate spontaneous entrainment. Experiments 2 and 3 (respectively) explored whether eye-tracking strengthens spontaneous entrainment by allowing the pickup of trajectory direction change information or allowing an increase in the amount of information to be picked-up. Results suggest that the eye-tracking enhancement of spontaneous entrainment is a consequence of increasing the amount of information available to be picked-up.

Screening for lung cancer with a low-dose computed tomography (CT) scan is estimated to prevent 3 deaths per 1000 individuals at high risk; however, false positive results and radiation exposure are relevant harms and deserve careful consideration. Screening candidates can only make an autonomous decision if doctors correctly inform them of the pros and cons of the method; therefore, this study aimed to evaluate whether doctors understand the test characteristics of lung cancer screening. In a randomized trial 556 doctors (members of the Austrian Respiratory Society) were invited to answer questions regarding lung cancer screening based on online case vignettes. Half of the participants were randomized to the group ‘solutions provided’ and received the correct solutions in advance. The group ‘solutions withheld’ had to rely on prior knowledge or estimates. The primary endpoint was the between-group difference in the estimated number of deaths preventable by screening. Secondary endpoints were the between-group differences in the prevalence of lung cancer, prevalence of a positive screening results, sensitivity, specificity, positive predictive value, and false negative rate. Estimations were also compared with current data from the literature. The response rate was 29% in both groups. The reduction in the number of deaths due to screening was overestimated six-fold (95% confidence interval CI: 4–8) compared with the actual data, and there was no effect of group allocation. Providing the correct solutions to doctors had no systematic effect on their answers. Doctors poorly understand the test characteristics of lung cancer screening. Providing the correct solutions in advance did not improve the answers. Continuing education regarding lung cancer screening and the interpretation of test characteristics may be a simple remedy. Clinical trial registered with www.clinicaltrials.gov (NCT02542332).

Background: Lung cancer screening with CT scan is increasingly being offered to individuals at high risk. However, false-positive results and low mortality reduction are relevant disadvantages that should be explained to screening candidates. This study evaluated whether doctors understand the test characteristics of lung cancer screening. Methods: 556 doctors were invited to answer questions regarding lung cancer screening based on online case vignettes. Half of the participants were randomized to the group 9solutions provided9 and received the correct solutions in advance. The group 9solutions withheld9 had to rely on prior knowledge or estimates. Results: Response rate was 29%. The reduction in the number of deaths due to screening was overestimated six-fold (95%CI: 4 to 8) compared with the actual data. Providing the correct solutions to doctors had no systematic effect on their answers. Compared with actual data from the literature, the prevalence of lung cancer was overestimated three-fold, while the prevalence of suspicious screening results, specificity, positive predictive value, and false-negative rate were underestimated. Conclusion: Doctors poorly understand the test characteristics of lung cancer screening. Offering the correct solutions in advance did not improve the answers. Continuing education regarding screening and the interpretation of test characteristics may be a remedy.

Past research has revealed that natural social interactions contain interactional synchrony. The present study describes new methods for measuring interactional synchrony in natural interactions and evaluates whether the behavioral synchronization involved in social interactions is similar to dynamical synchronization found generically in nature. Two methodologies, a rater-coding method and a computational video image method, were used to provide time series representations of the movements of the co-actors as they enacted a series of jokes (i.e., knock–knock jokes). Cross-spectral and relative phase analyses of these time series revealed that speakers’ and listeners’ movements contained rhythms that were not only correlated in time but also exhibited phase synchronization. These results suggest that computational advances in video and time series analysis have greatly enhanced our ability to measure interactional synchrony in natural interactions. Moreover, the dynamical synchronization in these natural interactions is commensurate with that found in more stereotyped tasks, suggesting that similar organizational processes constrain bodily activity in natural social interactions and, hence, have implications for the understanding of joint action generally.

Rhythmic limb movements have been shown to spontaneously coordinate with rhythmic environmental stimuli. Previous research has demonstrated how such entrainment depends on the difference between the movement periods of the limb and the stimulus, and on the degree to which the actor visually tracks the stimulus. Here we present an experiment that investigated how stimulus amplitude influences unintended visuomotor entrainment. Participants performed rhythmic forearm movements while visually tracking an oscillating stimulus. The amplitude and period of stimulus motion were manipulated. Larger stimulus amplitudes resulted in stronger entrainment irrespective of how participants visually tracked the movements of the stimulus. Visual tracking, however, did result in increased entrainment for large, but not small, stimulus amplitudes. Collectively, the results indicate that the movement amplitude of environmental stimuli plays a significant role in the emergence of unintended visuomotor entrainment.

Experimental treatment strategies using human umbilical cord blood mononuclear cells (hUCB MNCs) represent a promising option for alternative stroke therapies. An important point for clinical translation of such treatment approaches is knowledge on the therapeutic time window. Although expected to be wider than for thrombolysis, the exact time window for hUCB MNC therapy is not known. Our study aimed to determine the time window of intravenous hUCB MNC administration after middle cerebral artery occlusion (MCAO). Male spontaneously hypertensive rats underwent MCAO and were randomly assigned to hUCB MNC administration at 4, 24, 72, and 120 or 14 days. Influence of cell treatment was observed by magnetic resonance imaging on days 1, 8, and 29 following MCAO and by assessment of functional neurological recovery. On day 30, brains were screened for glial scar development and presence of hUCB MNCs. Further, influence of hUCB MNCs on necrosis and apoptosis in postischemic neural tissue was investigated in hippocampal slices cultures. Transplantation within a 72-h time window resulted in an early improvement of functional recovery, paralleled by a reduction of brain atrophy and diminished glial scarring. Cell transplantation 120 h post-MCAO only induced minor functional recovery without changes in the brain atrophy rate and glial reactivity. Later transplantation (14 days) did not show any benefit. No evidence for intracerebrally localized hUCB MNCs was found in any treatment group. In vitro hUCB MNCs were able to significantly reduce postischemic neural necrosis and apoptosis. Our results for the first time indicate a time window of therapeutic hUCB MNC application of at least 72 h. The time window is limited, but wider than compared to conventional pharmacological approaches. The data furthermore confirms that differentiation and integration of administered cells is not a prerequisite for poststroke functional improvement and lesion size reduction.

This research evaluated how the inertial properties of a tool influence tool-using actions. Grip patterns and movements of 3-, 4-, and 5-year-old children and adults were recorded while hammering. Results revealed that both number of pegs driven and movement amplitude increased developmentally and changed as a function of inertial properties of the tool but other aspects of motor control (i.e., period, grip position) did not. This suggests that both children and adults were able to discriminate and modulate only those parameters that had the largest impact on performance (i.e., the delivery of force with the hammer). Even though the ability to adjust tool movements as tool characteristics change is evident during preschool years, the ability to do so did not reach adult levels and appears to continue to develop beyond preschool.

Recently there has been much interest in social coordination of motor movements, or as it is referred to by some researchers, joint action. This paper reviews the cognitive perspective's common coding/mirror neuron theory of joint action, describes some of its limitations and then presents the behavioral dynamics perspective as an alternative way of understanding social motor coordination. In particular, behavioral dynamics' ability to explain the temporal coordination of interacting individuals is detailed. Two experiments are then described that demonstrate how dynamical processes of synchronization are apparent in the coordination underlying everyday joint actions such as martial art exercises, hand-clapping games, and conversations. The import of this evidence is that emergent dynamic patterns such as synchronization are the behavioral order that any neural substrate supporting joint action (e.g., mirror systems) would have to sustain.

In the first few months of 2010 the news media reported numerous instances of "unintended acceleration". Vehicles were recalled because a floor mat was thought to be snagging the accelerator pedal. However, some vehicles that had gone through the recall still experienced unintended accelerations, indicating that the problem also lay elsewhere. In the 1980s there were recalls of over 100,000 Audi vehicles with automatic transmissions in which drivers had reported unintended accelerations. Earlier cases had also been reported (Mortimer, 2011), so the issue is an old one. As a result of such runaway events, primarily in vehicles with automatic transmissions, automakers equipped them with shift-interlocks, so that the vehicle could not be moved into either a forward or reverse gear after starting the engine unless the driver's foot was depressing the brake pedal. About 83% of unintended acceleration events were reduced by this device (Schmidt, 1993), confirming the role of driver pedal misapplication when starting out. Other studies found that drivers show pedal confusions also when the vehicle is under way. Those events are not reduced by the shift-interlock. Rogers & Wierwille (1988) found about 0.2% of foot movements resulted in a "serious" pedal misapplication error in a simulator. Tomerlin & Vernoy (1990) found that 1 of 169 of their drivers stepped on the accelerator instead of the brake and continued to do so in a driving test. Such results show that drivers "frequently" make pedal errors, especially when considering that there is about one brake application per mile (Mortimer et al, 1970) in the U.S. The panel members will discuss the human factors issues that cause pedal misapplication in various types of vehicles and their frequency, including crashes that result. The thrust of the discussions will be on how our present knowledge can be used to reduce these hazardous events and to discern what additional information is needed to solve the "unintended acceleration" problem. Language: en

The paper explains basic ideas related to the design of a sliding-mode controller for an electromechanic drive system consisting of an induction motor and a three-level voltage-source inverter. A comprehensive investigation of possible “switched structures” of the drive was carried out. Based on this analysis an original two-step design procedure allows to use the “classical” result of sliding-mode theory for the real switched system with more then 2m switched structures (m is the control space order). The performance of the considered control structure has been examined by simulation.

Understanding stable patterns of interpersonal movement coordination is essential to understanding successful social interaction and activity (i.e., joint action). Previous research investigating such coordination has primarily focused on the synchronization of simple rhythmic movements (e.g., finger/forearm oscillations or pendulum swinging). Very few studies, however, have explored the stable patterns of coordination that emerge during task-directed complementary coordination tasks. Thus, the aim of the current study was to investigate and model the behavioral dynamics of a complementary collision-avoidance task. Participant pairs performed a repetitive targeting task in which they moved computer stimuli back and forth between sets of target locations without colliding into each other. The results revealed that pairs quickly converged onto a stable, asymmetric pattern of movement coordination that reflected differential control across participants, with 1 participant adopting a more straight-line movement trajectory between targets, and the other participant adopting a more elliptical trajectory between targets. This asymmetric movement pattern was also characterized by a phase lag between participants and was essential to task success. Coupling directionality analysis and dynamical modeling revealed that this dynamic regime was due to participant-specific differences in the coupling functions that defined the task-dynamics of participant pairs. Collectively, the current findings provide evidence that the dynamical coordination processes previously identified to underlie simple motor synchronization can also support more complex, goal-directed, joint action behavior, and can participate the spontaneous emergence of complementary joint action roles.

Background. Deep wound infection (DWI) in total knee (TKA) and total hip (THA) arthroplasty has been shown to highly correlate with superficial surgical site infection (SSSI). Although several studies have reported hospital factors that predispose to SSSI, patient factors have not been clearly elucidated. Methods. All patients undergoing TKA (n=1181) and THA (n=1124) surgery during the period 1977–1995 at our institution were observed at the end of a 30-day post-operative period. Thirty-three patients that developed SSSI during this period constituted the study group. The control group was composed of 64 matched subjects that did not develop SSSI. A chart review was applied to abstract DWI cases during the first 18 post-operative months for the study group and for an average of 6.7 years for the control group (range 5–18.2 years). Potential risk factors for SSSI were used as predictors of SSSI in a logistic regression analysis. Results. During the 18-month observation period 19 out of the 33 study subjects (58%) developed DWI. No DWI was registered in the control group (the difference was significant, p

For many everyday sensorimotor tasks, trained dancers have been found to exhibit distinct and sometimes superior (more stable or robust) patterns of behavior compared to non-dancers. Past research has demonstrated that experts in fields requiring specialized physical training and behavioral control exhibit superior interpersonal coordination capabilities for expertise-related tasks. To date, however, no published studies have compared dancers' abilities to coordinate their movements with the movements of another individual-i.e., during a so-called visual-motor interpersonal coordination task. The current study was designed to investigate whether trained dancers would be better able to coordinate with a partner performing short sequences of dance-like movements than non-dancers. Movement time series were recorded for individual dancers and non-dancers asked to synchronize with a confederate during three different movement sequences characterized by distinct dance styles (i.e., dance team routine, contemporary ballet, mixed style) without hearing any auditory signals or music. A diverse range of linear and non-linear analyses (i.e., cross-correlation, cross-recurrence quantification analysis, and cross-wavelet analysis) provided converging measures of coordination across multiple time scales. While overall levels of interpersonal coordination were influenced by differences in movement sequence for both groups, dancers consistently displayed higher levels of coordination with the confederate at both short and long time scales. These findings demonstrate that the visual-motor coordination capabilities of trained dancers allow them to better synchronize with other individuals performing dance-like movements than non-dancers. Further investigation of similar tasks may help to increase the understanding of visualmotor entrainment in general, as well as provide insight into the effects of focused training on visual-motor and interpersonal coordination.

Advances in video and time series analysis have greatly enhanced our ability to study the bodily synchronization that occurs in natural interactions. Past research has demonstrated that the behavioral synchronization involved in social interactions is similar to dynamical synchronization found generically in nature. The present study investigated how the bodily synchronization in a joke telling task is spread across different nested temporal scales. Pairs of participants enacted knock–knock jokes and times series of their bodily activity were recorded. Coherence and relative phase analyses were used to evaluate the synchronization of bodily rhythms for the whole trial as well as at the subsidiary time scales of the whole joke, the setup of the punch line, the two-person exchange and the utterance. The analyses revealed greater than chance entrainment of the joke teller’s and joke responder’s movements at all time scales and that the relative phasing of the teller’s movements led those of the responder at the longer time scales. Moreover, this entrainment was greater when visual information about the partner’s movements was present but was decreased particularly at the shorter time scales when explicit gesturing in telling the joke was performed. In short, the results demonstrate that a complex interpersonal bodily “dance” occurs during structured conversation interactions and that this “dance” is constructed from a set of rhythms associated with the nested behavioral structure of the interaction.

Pediatric rhinosinusitis is very common. Chronic rhinosinusitis (CRS) in children, as in adults, is defined as 12 weeks or more of signs and symptoms of inflammation of the sinuses. First-line therapy for pediatric CRS should be medical, including management of any underlying conditions causing mucosal congestion leading to sinus ostium obstruction.

(1999). Coordination Dynamics of Abdomen and Chest During Infant Breathing: A Comparison of Full-Term. Ecological Psychology: Vol. 11, No. 3, pp. 209-232.

Studies of bimanual coordination have found that only two stable relative phases (0 degree and 180 degrees) are produced when a participant rhythmically moves two joints in different limbs at the same frequency. Increasing the frequency of oscillation causes an increase in relative phase variability in both of these phase modes. However, relative phasing at 180 degrees is more variable than relative phasing at 0 degree, and when the frequency of oscillation reaches a critical frequency, a transition to 0 degree occurs. These results have been replicated when 2 people have coordinated their respective limb movements using vision. This inspired us to investigate the visual perception of relative phase. In Experiment 1, recordings of human interlimb oscillations exhibiting different frequencies, mean relative phases, and different amounts of phase variability were used to generate computer displays of spheres oscillating either side to side in a frontoparallel plane or in depth. Participants judged the stability of relative phase. Judgments covaried with phase variability only when the mean phase was 0 degree or 180 degrees. Otherwise, judgments covaried with mean relative phase, even after extensive instruction and demonstration. In Experiment 2, mean relative phase and phase variability were manipulated independently via simulations, and participants were trained to perceive phase variability in testing sessions in which mean phase was held constant. The results of Experiment 1 were replicated. The HKB model was fitted to mean judgment standard deviations.

This paper illustrates the advantages of laboratory research into SLA by describing two studies of acquisition of second language syntax. The first addresses the question of whether human morphological abilities can be understood in terms of associative processes or whether it is necessary to postulate rule-based symbol processing systems underlying these skills. We demonstrate that acquisition of L2 morphology shows frequency effects for both regular and irregular forms and that the acquisition course of learners' accuracy and reaction time can be accurately simulated by connectionist systems. The second concerns a bootstrapping account of SLA whereby processes of chunking in phonological memory underpin the acquisition of long-term memory for utterances and abstractions of grammatical regularities. It shows that phonological short-term memory is particularly important in the acquisition of long-distance dependencies. In both cases, it is argued that these aspects of SLA reflect associative learning processes. When SLA research is properly focused on acquisition, laboratory research allows investigation of the learners' exposure to evidence, their processes of perception and learning, and their resultant language representations.

Background. Chronic renal failure has been described only rarely in patients treated with the alkylating agent ifosfamide, which is known to cause renal tubular dysfunction and acute renal failure, and the associated histopathologic features have not been well characterized. Methods. This report describes the clinical course and renal histopathologic features in two patients in whom irreversible renal failure occurred requiring permanent dialysis after treatment with ifosfamide. Results. Irreversible renal failure developed in a 60-year-old man with malignant fibrohistiocytoma, requiring chronic dialysis within several months after he received two cycles of ifosfamide in a cumulative dose of 28 g/m2. The second patient, a 53-year-old man with osteogenic sarcoma, received two cycles of ifosfamide with a cumulative dose of 26 g/m2, after initial therapy with cisplatin and doxorubicin. His renal function worsened over the next 11 months, at which time permanent dialysis was initiated. In neither patient were other causes of renal failure apparent. Renal biopsies in both patients showed diffuse tubular epithelial damage with degenerative and regenerative epithelial changes, diffuse interstitial fibrosis, and arterial and arteriolar sclerosis. Conclusions. Irreversible severe renal failure, which appears due to nephrotoxic damage of renal tubular epithelium and/or the renal microvasculature may develop after treatment with ifosfamide. Neither large cumulative doses of ifosfamide nor prior cisplatin treatment are necessary for this toxicity to occur. Because a rising serum creatinine may develop months after completion of treatment with ifosfamide, renal function should be monitored closely both during and after ifosfamide treatment. Cancer 1995; 76:497-500.

Perception of whether a slanted surface supports upright stance was evaluated visually and haptically. Observers stood approximately 1 m from a 1 m by 1 m plywood board whose angle of inclination varied randomly among seven settings (12, 17, 22, 27, 33, 39, and 45 deg.). For visual trials, observers looked at the surface. For haptic trials, the observers were blindfolded and explored the surface with a hand-held wooden dowel. The perceived behavioral category boundary (i.e., the slope that received 50% yes responses) did not differ for visual and haptic judgments. Although the two perceptual systems did not differ in the mean, participants took longer to make haptic judgments and were less confident in doing so. For both perceptual systems, response time increased and confidence decreased at the category boundary. A second experiment used ascending and descending methods of limits and found both enhanced contrast and hysteresis effects for both perceptual systems. Differences between perceptual systems we...

Higher education customers can be defined as either the faculty, students or administration. The key stakeholder often has been identified as the student. Selecting a college is the first step the student undertakes in the educational process of a higher education. The educational value perception to be earned has an important impact on the student’s choice of a particular college. The value‐added concept of an organized activity originated in Europe. Applying the concept was difficult in manufacturing operations and it is even more difficult to apply it to a service operation such as higher education. Working through the application difficulties should provide valuable insights into why a student chooses a particular college over another similar institution. The out‐of‐pocket costs to attend a college may be a useful surrogate for the perceived value for the student in valuing the education from individual colleges.

At the level of tasks the problem of coordination is relating families of potential circumstances to families of potential movement patterns. Major theoretical efforts to address this problem hypothesize that any task-specific coordination is a function which generates for any given circumstance a movement pattern satisfying the task criteria. In three experiments spanning approximately two years, the same three subjects were required to achieve a 1:1 frequency locking of rhythmic motions about the wrists under variable circumstances comprising different loadings of the two limb segments. Mappings between measures of the coordination problem and measures of the coordination solution were determined. Similar single-valued functions spanning the period of investigation were observed for each subject. The results are discussed in terms of the parameterization of an oscillatory control structure by the magnitude and asymmetry of the inertial loadings at the wrists.

The beneficial effects of bone marrow-derived mesenchymal stromal cell (MSC) administration following experimental stroke have already been described. Despite several promising characteristics, placenta-derived MSC have not been used in models of focal ischemia. The aim of the current study is to investigate the impact of intravenously transplanted placenta-derived MSC on post-stroke recovery. Permanent occlusion of the middle cerebral artery was induced in spontaneously hypertensive rats. MSC were obtained from the human maternal or fetal placenta and intravenously administered after 24 h (single transplantation) or after 8 h and 24 h (dual transplantation). Sensorimotor deficits were quantified for 60 days using the beam walk test and the modified Neurological Severity Score system. Infarct volume was determined in vivo by means of magnetic resonance imaging on days 1, 8, 29 and 60. Astroglial reactivity was semiquantitatively ascertained within a small and a broad region adjacent to the lesion border. The double infusion of placental MSC was superior to single transplantation in the functional tests. However, a significant difference to the control group in all outcome parameters was observed only for maternally derived MSC. These findings suggest that placental tissue constitutes a promising source for experimental stroke therapies.

Previous research has demonstrated that when an actor coordinates with spatially incompatible movements of another individual that motor interference occurs-the rhythmic arm movements of the actor exhibit increased movement variability in the plane orthogonal (non-instructed) to the instructed plane of motion. Here we examine whether this motor contagion reflects not error but the spontaneous recruitment of additional task-specific movement degrees of freedom employed to withstand increasing task difficulty. Participants coordinated congruent and incongruent forearm movements with a confederate moving at a fast, moderate, and slow target frequency. Examining the variability in the non-instructed plane revealed oscillatory non-instructed plane movements that were coordinated with the instructed plane movements of the confederate. The results suggest motor interference during incongruent coordination can be understood as an emergent, task-specific property of the coordination goal.

Previous research has demonstrated that intra- and interpersonal rhythmic interlimb coordination are both constrained by the self-organizing entrainment process of coupled oscillators. Despite intra- and interpersonal coordination exhibiting the same stable macroscopic movement patterns the variability of the coordination is typically found to be much greater for inter- compared to intrapersonal coordination. Researchers have assumed that this is due to the interpersonal visual-motor coupling producing a weaker attractor dynamic than the intrapersonal neuromuscular coupling. To determine whether this assumption is true, two experiments were conducted in which pairs of participants coordinated hand-held pendulums swung about the wrist, either intra- and interpersonally. Using the cross-recurrence statistics of percent recurrence and maxline to independently index the level of noise and the attractor strength of the coordination, respectively, the results confirmed that the attractor strength was significantly weaker for inter- compared to intrapersonal coordination and that a similar magnitude of noise underlies both.

This study investigated the role that visual tracking plays in coupling rhythmic limb movements to an environmental rhythm. Two experiments were conducted in which participants swung a hand-held pendulum while tracking an oscillating stimulus or while keeping their eyes fixed on a stationary location directly above an oscillating stimulus. It was expected that the participants' rhythmic movements would become entrained to the oscillating stimulus in both conditions but that visual tracking would strengthen this entrainment. Experiment 1 investigated the role of visual tracking in establishing unintentional entrainment. Experiment 2 investigated the role of visual tracking in intentional entrainment. As predicted, participants exhibited greater unintentional coordination and more stable intentional coordination when they tracked the stimulus. These findings highlight the importance of understanding the role of eye movements in environmental coordination.

Alterations of video monitor and laparoscopic camera position may create perceptual distortion of the operative field, possibly leading to decreased laparoscopic efficiency. We aimed to determine the influence of monitor/camera position on the laparoscopic performance of surgeons of varying skill levels.Twelve experienced and 12 novice participants performed a one-handed task with their dominant hand in a modified laparoscopic trainer. Initially, the camera was fixed directly in front of the participant (0 degrees) and the monitor location was varied between three positions, to the left of midline (120 degrees), directly across from the participant (180 degrees), and to the right of the midline (240 degrees). In the second experiment monitor position was constant straight across from the participant (180 degrees) while the camera position was adjusted between the center position (0 degrees), to the left of midline (60 degrees), and to the right of midline (300 degrees). Participants completed five trials in each monitor/camera setting. The significance of the effects of skill level and combinations of camera and monitor angle were evaluated by analysis of variance (ANOVA) for repeated measures using restricted maximum likelihood estimation.Experienced surgeons completed the task significantly faster at all monitor/camera positions. The best performance in both groups was observed when the monitor and camera were located at 180 degrees and 0 degrees, respectively. Monitor positioning to the right of midline (240 degrees) resulted in significantly worse performance compared to 180 degrees for both experienced and novice surgeons. Compared to 0 degrees (center), camera position to the left or the right resulted in significantly prolonged task times for both groups. Novice subjects also demonstrated a significantly lower ability to adjust to suboptimal camera/monitor positions.Experienced subjects demonstrated superior performance under all study conditions. Optimally, the camera should be directly in front and the monitor should be directly across from a surgeon. Alternatively, the monitor/camera could be placed opposite to the surgeon's non-dominant hand. The suboptimal camera/monitor conditions are especially difficult to overcome for inexperienced subjects. Monitor and camera positioning must be emphasized to ensure optimal laparoscopic performance.

New therapeutic concepts of cell and tissue replacement therapies have been introduced in treatment of neurological disorders which require robust and sensitive sensomotoric behavioral diagnostic test systems for experimental research. However, most test arrays available are either expensive and/or sensitive to environmental disturbances. Moreover, an extensive training phase for experimental animals is often required by conventional tests to get reproducible data. In this study, we describe a new test array, the Stairway, that is robust, cost-effective, and needs only a minimum training phase. Its efficiency is evaluated in comparison to the well-established RotaRod and modified neurological severity score. Stroke was induced by middle cerebral artery occlusion. Human umbilical cord blood transplantation (n = 18) was performed 24 h after stroke by intravenous injection of suspended cells in comparison to control injections (n = 18), while behavioral assessment was carried out continuously for 29 days. Furthermore, development of lesions was monitored by magnetic resonance imaging. The results reveal the Stairway test as a simple, highly reproducible, and easy manageable test system thus reflecting therapeutic benefits precisely.

Unfortunately, this paper represents the inadvertent republication of a paper already published in Experimental Brain Research in 2009. This inadvertent double publication resulted from a technical error in Springer’s content management system. The original article, identical to this one, was published in Experimental Brain Research in Volume 199, Issue 1, pp 89–93, in 2009. Please always cite this original version in all future work.

Publisher Summary This chapter discusses a low-dimensional nonlinear dynamic governing interlimb rhythmic coordination. The standard circle map studied originally by Arnold has been used to provide a general theory of phase locking in two-oscillator systems via nonlinear coupling, and its potential application to coordination patterns in biological movement systems has been duly recognized. The particular mode of 1:1 frequency coordination—in-phase versus anti-phase—depends on the sign of the coupling coefficient K. The research program initiated by von Hoist suggests three major requirements for an experimental method directed at the dynamics of inter-appendage rhythmic coordinations. A major implication of von Hoist's perspective is that an interlimb rhythmic coordination is a pattern-selection process. Competition and cooperation among different attractors, both within a level and between levels, select the order parameter dynamics of the interlimb system.

Learning a bimanual rhythmic task is explored from the perspective that motor skill acquisition involves the successive reparameterization of a dynamical control structure in the direction of increasing stability, where the intentional process of reparameterization is itself dynamical. Subjects learned to oscillate pendulums held in the right and left hands such that the right hand frequency was twice that of the left (2:1 frequency lock). Over 12 learning sessions of 20 trials each, we interpreted the decreasing fluctuations in the frequency locking to be an index of the increasing concavity of the underlying potential, a measure of stability; the time required to achieve the 2: 1 pattern was interpreted as indexing the relaxation time of an intentional dynamic. Power spectral analyses of the phase velocity ratio exhibited two strategies for acquiring the interlimb movement pattern: (a) adding spectral peaks at integer multiples of the left hand frequency or (b) distributing power across many frequencies in a l/f-like manner. Results are discussed in terms of the promise of a dynamical approach to learning coordinated movements.

The lipid fraction constituents as well as evaluation of anti-anaphylactic activity of Prunus mahaleb L. Kernels were studied. Prunus mahaleb L. kernels were obtained from the local market in Cairo, Egypt. Investigation of the fatty acids revealed that oleic and linoleic acids are the major constituents. 12 compounds were identified from the hydrocarbon fraction. The sterol fraction comprises of cholesterol, stigmasterol, β-sitosterol and campesterol. The pharmacotoxicity studies were carried out on total and defatted ethanolic extracts as well as the oil fraction. The oil fraction proved to be extremely safe and free from any acute lethal toxicity in intraperitoneal (i.p.) and oral doses up to 100 ml/kg. Invivo assessment of prophylactic efficacy was afforded by 7 days course of daily medication schedule of sensitized adult male guinea pigs against ovalbumin bronchospasm. The prophylactic anti-inflammatory activity of the total ethanolic extract was higher than that of the defatted ethanolic extract. In addition, the lipid fraction of Prunus mahaleb L. kernels evoked complete anti-inflammatory efficacy among the survival animals receiving low and medium doses.

The article discusses the results of a study pertaining to the dominance of financial interest representation on the boards of directors of nonfinancial corporations. The inside-outside composition...

Forequarter amputation combined with chest wall resection may present a difficult closure problem. In a recent case, the defect was satisfactorily closed with a free flap from the amputated extremity, employing the entire soft tissue of the forearm.