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Highlights • VBM demonstrates cortical structural reorganization after vestibulo-cerebellar infarcts. • Structural reorganization extends beyond the cortical vestibular hubs. • Structural reorganization mirrors functional connectivity in healthy controls. • Reveals the multifaceted interconnection between cerebellum und cerebral cortex., Objective Structural reorganization following cerebellar infarcts is not yet known. This study aimed to demonstrate structural volumetric changes over time in the cortical vestibular and multisensory areas (i.e., brain plasticity) after acute cerebellar infarcts with vestibular and ocular motor symptoms. Additionally, we evaluated whether structural reorganization in the patients topographically correlates with cerebello-cortical connectivity that can be observed in healthy participants. Methods We obtained high-resolution structural imaging in seven patients with midline cerebellar infarcts at two time points. These data were compared to structural imaging of a group of healthy age-matched controls using voxel-based morphometry (2×2 ANOVA approach). The maximum overlap of the infarcts was used as a seed region for a separate resting-state functional connectivity analysis in healthy volunteers. Results Volumetric changes were detected in the multisensory cortical vestibular areas around the parieto-opercular and (retro-) insular cortex. Furthermore, structural reorganization was evident in parts of the frontal, temporal, parietal, limbic, and occipital lobes and reflected functional connections between the main infarct regions in the cerebellum and the cerebral cortex in healthy individuals. Conclusions This study demonstrates structural reorganization in the parieto-opercular insular vestibular cortex after acute vestibulo-cerebellar infarcts. Additionally, the widely distributed structural reorganization after midline cerebellar infarcts provides additional in vivo evidence for the multifaceted contribution of cerebellar processing to cortical functions that extend beyond vestibular or ocular motor function.

Objective Functional dizziness syndromes are among the most common diagnoses made in patients with chronic dizziness, but their underlying neural characteristics are largely unknown. The aim of this neuroimaging study was to analyze the disease-specific brain changes in patients with phobic postural vertigo (PPV). Methods We measured brain morphology, task response, and functional connectivity in 44 patients with PPV and 44 healthy controls. Results The analyses revealed a relative structural increase in regions of the prefrontal cortex and the associated thalamic projection zones as well as in the primary motor cortex. Morphological increases in the ventrolateral prefrontal cortex positively correlated with disease duration, whereas increases in dorsolateral, medial, and ventromedial prefrontal areas positively correlated with the Beck depression index. Visual motion stimulation caused an increased task-dependent activity in the subgenual anterior cingulum and a significantly longer duration of the motion aftereffect in the patients. Task-based functional connectivity analyses revealed aberrant involvement of interoceptive, fear generalization, and orbitofrontal networks. Interpretation Our findings agree with some of the typical characteristics of functional dizziness syndromes, for example, excessive self-awareness, anxious appraisal, and obsessive controlling of posture. This first evidence indicates that the disease-specific mechanisms underlying PPV are related to networks involved in mood regulation, fear generalization, interoception, and cognitive control. They do not seem to be the result of aberrant processing in cortical visual, visual motion, or vestibular regions.

Previous unimodal PET and fMRI studies in humans revealed a reproducible vestibular brain activation pattern, but with variations in its weighting and expansiveness. Hybrid studies minimizing methodological variations at baseline conditions are rare and still lacking for task-based designs. Thus, we applied for the first time hybrid 3T PET-MRI scanning (Siemens mMR) in healthy volunteers using galvanic vestibular stimulation (GVS) in healthy volunteers in order to directly compare H215O-PET and BOLD MRI responses. List mode PET acquisition started with the injection of 750 MBq H215O simultaneously to MRI EPI sequences. Group-level statistical parametric maps were generated for GVS vs. rest contrasts of PET, MR-onset (event-related), and MR-block. All contrasts showed a similar bilateral vestibular activation pattern with remarkable proximity of activation foci. Both BOLD contrasts gave more bilateral wide-spread activation clusters than PET; no area showed contradictory signal responses. PET still confirmed the right-hemispheric lateralization of the vestibular system, whereas BOLD-onset revealed only a tendency. The reciprocal inhibitory visual-vestibular interaction concept was confirmed by PET signal decreases in primary and secondary visual cortices, and BOLD-block decreases in secondary visual areas. In conclusion, MRI activation maps contained a mixture of CBF measured using H215O-PET and additional non-CBF effects, and the activation-deactivation pattern of the BOLD-block appears to be more similar to the H215O-PET than the BOLD-onset.

Cylindrical springs have been commonly exploited in mechanical systems for years. While the behavior of compression springs can be considered as well identified, the understanding of the behavior of extension springs still needs improvement as it appears that the influence of the loops on the global stiffness is not yet taken into account properly. Moreover, it would be of key interest to analyze how initial tension in extension springs influences the beginning of the load-length curve. The paper investigates these topics using analytical and experimental approaches in order to help engineers design extension springs with greater accuracy. Several loop geometries are tested and Castigliano’s theorem is exploited to propose an analytical formula for the stiffness of each. Experimental tests have been performed on a set of extension springs with non-basic loops in order to evaluate the accuracy of the formulae.

Aviation industry and governing bodies have set out to significantly reduce the environmental footprint of aviation. The visions brought forward request such low emissions that continuous optimization and advancement of current technology alone are not sufficient. This has led research groups to explore disruptive paths of innovation for aircraft and a trend to the electrification of onboard systems in more electric aircraft. Providing the required electric power using fuel cells and batteries not only promises the reduction of carbon emissions and noise but also allows for system level optimizations using synergy effects from a multi-functional system-integration that aircraft design could benefit from. At the same time using fuel cells in aircraft environments provides great challenges towards system design. System weight and size constraints require the use of air breathing fuel cells in commercial aircraft and airliners. This results in operation at low pressure and temperature which in term confronts the system design with two problems. First the low air density makes cooling of power systems difficult especially considering the low operating temperatures of PEM Fuel Cells. Second the low ambient temperature means the ingested air will heat up much more than during ground operation and in term will remove more water from the fuel cells, making water management and fuel cell operation strategies more important and complicated than in other applications. Also ambient conditions very rapidly change in air, adding even more complexity to the application. Taking into consideration possibilities of advanced aerodynamic concepts like distributed propulsion and propulsion/wing vortex interaction, that electric propulsion could enable, Fuel cells could be of even larger benefit for aviation when considering a larger time-frame. All-electric aircraft could potentially be emissions-free and very low noise, thus enabling sustainable, environmentally friendly aviation. While not yet feasible for large passenger aircraft, application of such systems is currently being researched in aircraft like the HY4 enroute to this goal. This presentation will discuss the challenges of fuel cell operation in-flight, as well as introduce the concepts for multifunctional fuel cell APU replacements for A320 type aircraft and drive-trains for all-electric aircraft. Finally results from ground- and flight-testing of the all-electric fuel cell powered HY4 aircraft will be discussed.

International audience; Cylindrical extension springs have been commonly exploited in mechanical systems for years and their behavior could be considered as well identified. Nevertheless, it appears that the influence of the loops on the global stiffness is not yet taken into account properly. Moreover, it would be of key interest to analyze how initial tension in extension springs influences the beginning of the load-length curve. The paper investigates these topics using analytical, simulation and experimental approaches in order to help engineers design extension springs with greater accuracy. As a result, the stiffness of the loops has been analytically defined. It enables to calculate the global stiffness of extension springs with more accuracy and it is now possible to determine the effective beginning of the linear load-length relation of extension springs and thus to enlarge the operating range commonly defined by standards. Moreover, until now manufacturers had to define by a try and error process the axial pitch of the body of extension springs in order to obtain the required initial tension. Our study enables for the first time to calculate quickly this key parameter saving time on the manufacturing process of extension springs.

This paper presents an overview of the challenges encountered in underwater sensing. Two state-of-the-art approaches are presented dealing with optic and acoustic sensor data processing. Employing suitable methods for the different modalities enables fusion of the information contained in the optic radiative transfer and acoustic reflectivity.

Some blind humans have developed echolocation, as a method of navigation in space. Echolocation is a truly active sense because subjects analyze echoes of dedicated, self-generated sounds to assess space around them. Using a special virtual space technique, we assess how humans perceive enclosed spaces through echolocation, thereby revealing the interplay between sensory and vocal-motor neural activity while humans perform this task. Sighted subjects were trained to detect small changes in virtual-room size analyzing real-time generated echoes of their vocalizations. Individual differences in performance were related to the type and number of vocalizations produced. We then asked subjects to estimate virtual-room size with either active or passive sounds while measuring their brain activity with fMRI. Subjects were better at estimating room size when actively vocalizing. This was reflected in the hemodynamic activity of vocal-motor cortices, even after individual motor and sensory components were removed. Activity in these areas also varied with perceived room size, although the vocal-motor output was unchanged. In addition, thalamic and auditory-midbrain activity was correlated with perceived room size; a likely result of top-down auditory pathways for human echolocation, comparable with those described in echolocating bats. Our data provide evidence that human echolocation is supported by active sensing, both behaviorally and in terms of brain activity. The neural sensory-motor coupling complements the fundamental acoustic motor-sensory coupling via the environment in echolocation.SIGNIFICANCE STATEMENTPassive listening is the predominant method for examining brain activity during echolocation, the auditory analysis of self-generated sounds. We show that sighted humans perform better when they actively vocalize than during passive listening. Correspondingly, vocal motor and cerebellar activity is greater during active echolocation than vocalization alone. Motor and subcortical auditory brain activity covaries with the auditory percept, although motor output is unchanged. Our results reveal behaviorally relevant neural sensory-motor coupling during echolocation.

Measuring the volume of dirt particles within the context of technical cleanliness is a crucial task, because the measured 3D shape yields important information concerning the risks those particles might cause while operating the technical component in the intended application. The production process therefore needs to be optimized to take care, that such particles are not introduced into the final product during fabrication. Measuring 3D volume in the range of a few microns concerning the area of a particle implies expensive microscope measuring devices. In this paper we describe a hardware approach combined with software algorithms using eight LED lights for illuminating the specimen from various known directions. The LEDs are used to produce cast shadows of the specimen to be inspected. The circular layout of the LEDs takes care to illuminate the particles out of different directions to yield shadows surrounding the whole object. The brightness of the LEDs can be manipulated to adapt for various specimen with different reflection properties. Our model driven approach uses a grid, which is aligned to the image data in order to sample the surface for estimating the height at those discrete positions. The model-driven approach incorporates the measurement results given by established state-of-the-art microscopes for initial calibration. The estimated heights are illustrated in a 2.5D pseudo-color representation and evaluated from a quality point of view. The approach described in this paper yields a practical solution for estimating 3D shape and volume with little hardware requirements and therefore low maintenance costs.

The free-field response of NordicNeuroLab AudioSystem electrostatic headphones for use in functional magnetic resonance imaging (fMRI) is determined by loudness comparisons with free-field equalized Beyerdynamic DT 48 headphones. Based on these measurements, an active equalizer with resonances at 0.55, 1.5, and 6.9 kHz is developed, realized, and tested. A free-field equivalent level independent of frequency within ±3 dB between 63 Hz and 10 kHz is obtained when using the AudioSystem headphones with the described free-field equalizer.

In functional magnetic resonance imaging (fMRI) studies, brain areas that are commonly associated with the processing of olfactory stimuli, i.e., piriform cortex and orbitofrontal cortex, are often obscured by susceptibility-induced signal loss. The authors hypothesized that using a short echo time (TE) should not only reduce susceptibility artifacts but also increase the overall signal-to-noise ratio and allow to retrieve a blood oxygenation level-dependent (BOLD) signal in regions normally affected by these artifacts. Two sequences with TEs of 60 and 32 ms were compared using a 1.5-T MRI scanner: in a standard motor paradigm, activations of the contralateral motor cortex were measured. In an olfactory stimulation paradigm, activations in piriform cortex were compared. Reducing TE from 60 to 32 ms reduced the observed signal intensity changes in the motor paradigm by 51%. Concomitant to this, geometric distortions and signal dropout artifacts were decreased at orbitofrontal and temporomesial brain areas in both paradigms. Contrary to the authors’ expectations, the signal intensity changes in the piriform cortex were also reduced by 48% in the olfactory paradigm. Moreover, piriform cortex activation was detected in less subjects at TE = 32 ms than at TE = 60 ms. Changes in cortical activation were significant in the right, but not in the left piriform cortex. Although a shorter TE reduces signal dropouts due to susceptibility artifacts, this shorter TE is not sufficient to recover the BOLD signal from regions affected by susceptibility artifacts such as the piriform cortex. Thus, reducing the TE to the T2* of the investigated region is not an effective approach to improve the results of olfactory fMRI studies.

During fixation of a stationary, dim light-emitting diode (LED) in complete darkness, a subtle, apparent motion is perceived which is called autokinesis. This autokinetic illusion increases with increasing fixation time. Eleven healthy subjects were examined by fMRI while fixating an LED in darkness for 35 s. BOLD signal changes of the first and the second half of the fixation period were compared. While the stimulus was the same for both periods, perception differed in that autokinesis was more pronounced in the second half. This second half of the period was associated with bilateral activations in the motion-sensitive middle occipito-temporal area known as MT/V5. Our finding suggests that area MT/V5 is involved in the mediation of autokinesis.

Mass responses that are obtained using electrophysiological or psychophysical techniques are inadequate to characterize motion detectors at the single-unit level. Therefore, we have modelled a population of motion detectors and fitted their mass response to motion-onset EEG data. By examining a single unit of the modelled population we could assess the range of directions and the level of adaptation an individual motion detector responded to. Stimuli were patterns of randomly distributed dots. After subjects had adapted to either a non-moving pattern or to motion in one fixed direction, the pattern moved in one of seven possible test directions. The population model assumed elementary motion detectors with a Gaussian angle-selectivity profile. The population response was calculated as the sum of all adaptation-weighted individual responses to the test direction. In all subjects, we observed sizeable effects of adaptation on test directions close to the adapted direction and small amounts of direction-independent adaptation for all test directions. The model fit explained 75% (Oz) and 94% (lateral derivation) of the total variance and revealed a motion detector bandwidth (full width at half maximum) of 72 degrees (Oz) and 62 degrees (lateral derivation). The maximal adaptation depth was estimated as 72% (Oz) and 66% (lateral derivation). Estimates inferred from the population model representing human motion detectors were found to be close to those obtained by single-cell data from non-human primates.

When technical goods, like mainboards and other electronic components, are produced, quality assurance (QA) is very important. To achieve this goal, different optical microscopes can be used to analyze a variety of specimen to gain comprehensive information by combining the acquired sensor data. In many industrial processes, cameras are used to examine these technical goods. Those cameras can analyze complete boards at once and offer a high level of accuracy when used for completeness checks. When small defects, e.g. soldered points, need to be examined in detail, those wide area cameras are limited. Microscopes with large magnification need to be used to analyze those critical areas. But microscopes alone cannot fulfill this task within a limited time schedule, because microscopic analysis of complete motherboards of a certain size is time demanding. Microscopes are limited concerning their depth of field and depth of focus, which is why additional components like XY moving tables need to be used to examine the complete surface. Yet today’s industrial production quality standards require a 100 % control of the soldered components within a given time schedule. This level of quality, while keeping inspection time low, can only be achieved when combining multiple inspection devices in an optimized manner. This paper presents results and methods of combining industrial cameras with microscopy instrumenting a classificatory based approach intending to keep already deployed QA processes in place but extending them with the purpose of increasing the quality level of the produced technical goods while maintaining high throughput.

Visual imaging under water is characterized by low range of visibility and poor image quality. Light interacts with water and its inherent particles in the form of absorption and scattering, causing image degradations, which have to by considered by underwater imaging systems. This can be done by optimizing the image acquisition and image post processing with respect to the properties of water and scene. Therefore a physically based computer graphical model is presented which describes the occurring effects of blurring, loss of contrast, color shift and brightening through backscattering. This model can be used for both: efficient simulation of underwater images and model based image restoration. Furthermore, the presented model can be used to answer theoretical questions on visibility range and imaging performance.

Outlining two ways of thinking about the relationship between speaking and writing—one which holds speech as anterior and superior to writing, which it sees as a secondary system of representation, and the other which views speech as being a form of writing itself operating within the play of difference and deferral that is language as such; the essay suggests that the two novels in question propose a third position that contains elements of both the previous two. This position is captured in key instances in both The English Patient and Divisadero of the written word being read out loud in a communal setting. In view of Lucien and Marie-Neige’s and Hana and the English patient’s practice of reading out loud to each other, Divisaderoand The English Patientsuggest that reading—whether it be studious, curious, or otherwise escapist in nature—is a vital act of incorporation, a political act of consumption wherein words become flesh and the stories in books come into confrontation with the texts of our selves in an explosion of intertextuality.

Functional magnetic resonance imaging blood-oxygenation-level-dependent (BOLD) signal increases (activations) and BOLD signal decreases (“deactivations”) were compared in six healthy volunteers during galvanic vestibular (mastoid) and galvanic cutaneous (neck) stimulation in order to differentiate vestibular from ocular motor and nociceptive functions. By calculating the contrast for vestibular activation minus cutaneous activation for the group, we found activations in the anterior parts of the insula, the paramedian and dorsolateral thalamus, the putamen, the inferior parietal lobule [Brodmann area (BA) 40], the precentral gyrus (frontal eye field, BA 6), the middle frontal gyrus (prefrontal cortex, BA 46/9), the middle temporal gyrus (BA 37), the superior temporal gyrus (BA 22), and the anterior cingulate gyrus (BA 32) as well as in both cerebellar hemispheres. These activations can be attributed to multisensory vestibular and ocular motor functions. Single-subject analysis in addition showed distinctly nonoverlapping activations in the posterior insula, which corresponds to the parieto-insular vestibular cortex in the monkey. During vestibular stimulation, there was also a significant signal decrease in the visual cortex (BA 18, 19), which spared BA 17. A different “deactivation” was found during cutaneous stimulation; it included upper parieto-occipital areas in the middle temporal and occipital gyri (BA 19/39/18). Under both stimulation conditions, there were signal decreases in the somatosensory cortex (BA 2/3/4). Stimulus-dependent, inhibitory vestibular-visual, and nociceptive-somatosensory interactions may be functionally significant for processing perception and sensorimotor control.

We discuss the inherent difficulties that arise during "ground truth" characterization of the Stardust interstellar dust collector. The challenge of identifying contemporary interstellar dust impact tracks in aerogel is described within the context of background spacecraft secondaries and possible interplanetary dust particles and beta-meteoroids. In addition, the extraction of microscopic dust embedded in aerogel is technically challenging. Specifically, we provide a detailed description of the sample preparation techniques developed to address the unique goals and restrictions of the Interstellar Preliminary Exam. These sample preparation requirements and the scarcity of candidate interstellar impact tracks exacerbate the difficulties. We also illustrate the role of initial optical imaging with critically important examples, and summarize the overall processing of the collection to date.

The inspection of offshore parks, dam walls and other infrastructure under water is expensive and time consuming, because such constructions must be inspected manually by divers. Underwater buildings have to be examined visually to find small cracks, spallings or other deficiencies. Automation of underwater inspection depends on established water-proved imaging systems. Most underwater imaging systems are based on acoustic sensors (sonar). The disadvantage of such an acoustic system is the loss of the complete visual impression. All information embedded in texture and surface reflectance gets lost. Therefore acoustic sensors are mostly insufficient for these kind of visual inspection tasks. Imaging systems based on optical sensors feature an enormous potential for underwater applications. The bandwidth from visual imaging systems reach from inspection of underwater buildings via marine biological applications through to exploration of the seafloor. The reason for the lack of established optical systems for underwater inspection tasks lies in technical difficulties of underwater image acquisition and processing. Lightening, highly degraded images make a computational postprocessing absolutely essential.

The Institute of Technical Thermodynamics of the German Aerospace Center (DLR e.V) has been conducting research on fuel cell systems for aircraft applications for several years. Aim of this work is the qualification of fuel cell systems for usage in aeronautical environment. In this paper two projects of the department of Electrochemical Energy Conversion are presented: Firstly the fuel cell powered nose wheel drive, which has been demonstrated successfully in July 2011. Secondly the Antares DLR-H2 – the flying test bed for fuel cell research under aeronautical conditions – which had completed initial long distance flight testing in September 2012.

Fuel cell systems provide a zero-emission and low noise solution for on-board power generation in aircraft. To assure safe and reliable fuel cell operation in aircraft, system testing has to be conducted under realistic operating conditions. On the one hand these conditions can hardly be simulated in laboratory; on the other hand evaluation of the systems with a wide-body aircraft like an Airbus A320 is inflexible, time and cost consuming. Therefore the aerodyne Antares DLR-H2 has been developed as a flying test bed to provide a system carrier for time and cost effective airborne fuel cell system testing. In this presentation the test platform Antares DLR-H2 will be described with the new fuel cell system generation and latest results, comprising laboratory measurements (fuel consumption, power output) and insights on the system design, especially focusing on the concept of direct hybridization, allowing a simple and therefore reliable possibility of coupling fuel cells and batteries.

In this contribution we present a method for handling merged detections in video-based Multi-Target-Tracking applications. Merged detections occur when two or more objects evoke one joint detection, i.e. when measurements stemming from multiple objects cannot be resolved by the sensor. In video-based applications this is the case when the segmentation fails to separate blobs belonging to different objects. The proposed approach is based on the specification of candidate merge events and resulting data association events. We propose a concept which allows recognition of the merge events and a correct track update in case of identified merges. This is done by generating artificial (virtual) measurements (measurement reconstruction) through decomposition of respective detections. The globally optimal solution is achieved by weighting different candidate hypotheses according to their a-posteriori probabilities.

The paper describes the layout of a new research aircraft for security applications. The typical applications for such an aircraft are outlined and the system requirements are derived. Furthermore, the performance of the system and a first mission is described.

Motion correction algorithms are commonly used to correct for involuntary head motions in fMRI. We found that lid closure increased signal intensity of the eyes by a factor of 1.6 to 2 in EPI-fMRI. If the eyes were included in the scanning volume, transitions from eyes open to eyes closed in darkness were regularly associated with erroneously detected head translations along the z-axis and head rotations around the x-axis in Talairach's coordinate system. These artefacts could be avoided by masking the eyes in the images during the estimation of movement parameters.

In this study we attempted to differentiate distinct components of the saccade network, namely cortical ocular motor centers and parieto-occipital brain regions, by means of a “minimal design” approach. Using a blocked design fMRI paradigm we evaluated the BOLD changes in a 2 × 2 factorial design experiment which was performed in complete darkness: while looking straight ahead with eyes open (OPEN) or closed (CLOSED) as well as during the execution of self-initiated horizontal to-and-fro saccades with the eyes open (SACCopen) or closed (SACCclosed). Eye movements were monitored outside the scanner via electro-oculography and during scanning using video-oculography. Unintentional eye-drifts did not differ during OPEN and CLOSED and saccade frequencies, and amplitudes did not vary significantly between the two saccade conditions. The main findings of the functional imaging study were as follows: (1) Saccades with eyes open or closed in complete darkness lead to distinct differences in brain activation patterns. (2) A parieto-occipital brain region including the precuneus, superior parietal lobule, posterior part of the intraparietal sulcus (IPS), and cuneus was relatively deactivated during saccades performed with eyes closed but not during saccades with eyes open or when looking straight ahead. This could indicate a preparatory state for updating spatial information, which is active during saccades with eyes open even without actual visual input. The preparatory state is suppressed when the eyes are closed during the saccades. (3) Selected ocular motor areas, not including the parietal eye field (PEF), show a stronger activation during SACCclosed than during SACCopen. The increased effort involved in performing saccades with eyes closed, perhaps due to the unusualness of the task, may be the cause of this increased activation.

The center of mass (COM) in functional MRI studies is defined as the center of a cerebral activation cluster. Although the COM is a well-accepted parameter for exactly localizing brain function, the reliability of COMs has not received much attention until now. Our goal was to investigate COM reliability as a function of the thresholding technique, the threshold level, and the type of COM calculation. Therefore 15 subjects were examined repeatedly using simple hand and tongue movement paradigms. Postprocessing was performed with uncorrected, corrected, and proportional thresholding as well as different threshold levels. Geometric and T-weighted COMs of left-hemispheric primary hand and tongue motor clusters were calculated. The COM variation was evaluated within and between repeated sessions depending on the different postprocessing setups. Mean COM variations over three repeated sessions varied between 1.6 mm and 9.8 mm for the hand paradigm and between 7.0 mm and 14.4 mm for the tongue task. Stringent thresholding techniques and high threshold levels were required to assess reliable results, whereas the kind of COM calculation was of lesser relevance. Thus, COM reliability cannot be presupposed; it depends strongly on the individual postprocessing techniques. This should be considered when using COMs for localizing brain function.

SolFocus? is developing two generations of photovoltaic concentrator systems, both based on reflective, Cassegrain ? like architectures. Generation 1 is being readied for manufacturing, and is poised for roll out to test fields this year. Generation 2, a solid dielectric system, is under joint development by SolFocus and PARC, with prototype components under evaluation. The status of generation 1 is presented for background, and we discuss technical aspects of generation 2.

The differential effects of visual hemifield motion stimulation during fixation of a stationary target were compared under two conditions: fixation straight ahead without any further instructions and fixation straight ahead with attention shifted to the "dark hemifield." Data from nine right-handed volunteers revealed that striate and extrastriate right hemispheric visual areas exhibited larger activations during left hemifield motion stimulation when attention was shifted to the right dark hemifield. Montreal Neurological Institute (MNI) coordinates (26, -98, -4) of the additional clusters activated in the latter condition corresponded best to the kinetic occipital region, which is known to process both shape and motion information, and to parts of area V3 posterior to V3A, which has been shown repeatedly to mediate motion perception. A simple computational model of transhemispheric visuovisual interaction is proposed. The basic mechanism of this model is a central predictor formed by a feedback loop that detects a mismatch between input to the two hemispheres. Predicted stimulation is then compared with the actual input. If the sensed motion of a visual hemifield is larger than the predicted net motion in the model, activation of the respective neural population is increased; conversely, a smaller actual motion causes less activation.

We used BOLD fMRI to study the differential effects of the direction of gaze on the visual and the ocular motor systems. Fixation of a target straight ahead was compared to fixation of a target 10 degrees to the right and 10 degrees to the left from gaze straight ahead, and to eyes open in complete darkness in thirteen healthy volunteers. While retinotopic coordinates remained the same in all fixation conditions, the fixation target shifted with respect to a head-centered frame of reference. During lateral fixation, deactivations in higher-order visual areas (one ventral cluster in the lingual and fusiform gyri and one dorsal cluster in the postero-superior cuneus) and, as a trend, activations in early visual cortical areas were found predominantly in the hemisphere contralateral to the fixation target. We propose that visual processing is performed predominantly in the hemisphere contralateral to gaze direction, even during small gaze shifts into one visual hemifield. The excitability of visual neurons may be modulated depending on eye position to construct a head-centered frame of reference from a retinotopic input, thus allowing perceptual stability of space during eye movements. A further finding was that BOLD signal increases in fronto-parietal ocular motor and attentional structures were more pronounced during lateral than central fixation.

Contrast adaptation occurs in both the retina and the cortex. Defining its spatial dependence is crucial for understanding its potential roles. We thus asked to what degree contrast adaptation depends on spatial frequency, including cross-adaptation. Measuring the pattern electroretinogram (PERG) and the visual evoked potential (VEP) allowed separating retinal and cortical contributions. In ten subjects we recorded simultaneous PERGs and VEPs. Test stimuli were sinusoidal gratings of 98% contrast with spatial frequencies of 0.5 or 5.0 cpd, phase reversing at 17 reversals/s. Adaptation was controlled by prolonged presentation of these test stimuli or homogenous gray fields of the same luminance. When adaptation and test frequency were identical, we observed significant contrast adaptation only at 5 cpd: an amplitude reduction in the PERG (−22%) and VEP (−58%), and an effective reduction of latency in the PERG (−0.95 ms). When adapting at 5 cpd and testing at 0.5 cpd, the opposite effect was observed: enhancement of VEP amplitude by +26% and increase in effective PERG latency by +1.35 ms. When adapting at 0.5 cpd and testing at 5 cpd, there was no significant amplitude change in PERG and VEP, but a small effective PERG latency increase of +0.65 ms. The 0.5-cpd channel was not adapted by spatial frequencies of 0.5 cpd. The adaptability of the 5-cpd channel may mediate improved detail recognition after prolonged blur. The existence of both adaptable and nonadaptable mechanisms in the retina allows for the possibility that by comparing the adaptational state of spatial-frequency channels the retina can discern between overall low contrast and defocus in emmetropization control.

Introduction: JI-101 is a highly selective and potent angiogenesis inhibitor with unique EphB4 activity that distinguishes it from other agents in clinical development. We report the preclinical pharmacology and early clinical experience with this compound. Procedures: Lead optimization was used to identify cgi1842 (now JI-101) with a targeted activity profile that is selective and unique. JI-101 was tested in binding, enzymatic, and cell-based assays for activity against kinase and non-kinase targets. Preclinical in vivo testing for PK, PD, efficacy, and safety pharmacology was performed in mouse, rat, guinea pig, and dog. A Phase I clinical trial is underway: 9 patients, 3/cohort, are being treated with 28-day oral daily dosing at 100 mg, 200 mg, and 400 mg. PK, PD, and imaging analyses are being performed. Data: JI-101 has a MW of 466D and high ( Conclusions: JI-101 potently inhibits 3 critical angiogenic kinases (VEGFR2, EphB4, and PDGFR) and is the only such “triple” angiogenesis inhibitor currently in development. JI-101 shows robust preclinical and clinical pharmacology and is well-tolerated to date in human trials. In tumors where EphB4 may play an oncogenic role, such as head and neck cancer, JI-101 may have anti-proliferative effects in addition to anti-angiogenic effects and should be amenable to combination therapy. Citation Information: Mol Cancer Ther 2009;8(12 Suppl):B11.

The scientific community has expressed strong interest to re-fly Stardust-like missions with improved instrumentation. We propose a new mission concept, SARIM, that collects interstellar and interplanetary dust particles and returns them to Earth. SARIM is optimised for the collection and discrimination of interstellar dust grains. Improved active dust collectors on-board allow us to perform in-situ determination of individual dust impacts and their impact location. This will provide important constraints for subsequent laboratory analysis. The SARIM spacecraft will be placed at the L2 libration point of the Sun–Earth system, outside the Earth’s debris belts and inside the solar-wind charging environment. SARIM is three-axes stabilised and collects interstellar grains between July and October when the relative encounter speeds with interstellar dust grains are lowest (4 to 20 km/s). During a 3-year dust collection period several hundred interstellar and several thousand interplanetary grains will be collected by a total sensitive area of 1 m2. At the end of the collection phase seven collector modules are stored and sealed in a MIRKA-type sample return capsule. SARIM will return the capsule containing the stardust to Earth to allow for an extraction and investigation of interstellar samples by latest laboratory technologies.