1,225 research outputs found

    Comparative anatomy of the rostrosoma of Solifugae, Pseudoscorpiones and Acari

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    We compare the microscopic anatomy of the mouthparts of representative species of Solifugae, Pseudoscorpiones and Parasitiformes (Acari). Specifically, we focus on the epistome, the labrum, the lateral lips (= endites of the pedipalpal coxae) and the musculature of the pharyngeal suction pump. We provide evidence that the labrum is reduced in Solifugae, but present and functional in Pseudoscorpiones and Acari. The epistome constitutes the entire dorsal face of the rostrosoma in Solifugae, but is internalized into the prosoma in Pseudoscorpiones. In Acari, the epistome shows an ancestral morphology, probably close to the ground pattern of chelicerates. The lateral lips of Solifugae contribute to the ventral face of the rostrosoma and the two lips of the mouth opening. In Solifugae, the ventral rostrosoma also includes a sclerite that might derive from a tritosternum. In Pseudoscorpiones, the lateral lips remain independent of the rostrosoma, they interlock ventral to the rostrosoma forming a perioral space. Here, the rostrosoma has an unpaired ventral lip of unresolved morphological origin, which is, however, clearly distinct from the lateral lips of Solifugae. The pharyngeal suction pump differs in all three clades in attachment, number of muscles and origin of muscles. We interpret the data as evidence for independent, parallel evolution of elements of the ground pattern of the (eu)chelicerate mouth parts. Based on the morphological elements of a common euchelicerate ground plan, the rostrosoma evolved independently in the three clades. We reject earlier hypotheses that consider the rostrosoma a character to support a phylogenetic relationship of the three clades

    Sakrale Neuromodulation bei neurogenen Blasenfunktionsstörungen

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    Zusammenfassung: Die sakrale Neuromodulation (SNM) stellt bei therapierefraktären neurogenen Blasenfunktionsstörungen eine vielversprechende Therapieoption dar. Es bleibt allerdings zu zeigen, welche Typen der neurogenen Blasenfunktionsstörungen und welche zugrunde liegenden neurologischen Erkrankungen am besten auf die SNM ansprechen. Die SNM wurde ständig weiterentwickelt und ist heute ein minimal-invasives, in Lokalanästhesie durchführbares Therapieverfahren, das vor größeren rekonstruktiven Eingriffen zumindest erwogen werden sollte. Es wird eine Elektrodenimplantation ins Sakralforamen S3 oder S4 durchgeführt und in einer Testphase über Tage bis Wochen unter Führen eines Blasentagebuches geprüft, ob die SNM dem Patienten einen relevanten Nutzen bringt. Wenn sich eine positive Testphase zeigt, wird der Neuromodulator gluteal (oder seltener in die Bauchdecke) implantiert. Der Wirkmechanismus der SNM ist nicht gänzlich geklärt, doch Afferenzen dürften eine Schlüsselrolle spielen. So scheint die SNM via periphere Afferenzen eine Modulation von Rückenmarkreflexen und Gehirnzentren zu bewirken. Das implantierte Neuromodulationssystem führt zu keiner Einschränkung der Aktivitäten der Patienten. Allerdings gilt es zu beachten, dass bei Neuromodulatorträgern Hochfrequenzwärmetherapie und unipolare Elektrokauterisation kontraindiziert sind, dass bei einer extrakorporellen Stoßwellenlithotripsie der Brennpunkt nicht in unmittelbarer Nähe des Neuromodulators oder der Elektrode liegen darf, dass Ultrasonographie und Strahlentherapie im Bereich der Implantatkomponenten vermieden werden sollten, dass bei Schwangerschaft der Neuromodulator auszuschalten ist und dass MR-Untersuchungen nur bei zwingender Indikation und bei ausgeschaltetem Neuromodulator durchgeführt werden solle

    Verification of Snapshotable Trees using Access Permissions and Typestate

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    Abstract. We use access permissions and typestate to specify and verify a Java library that implements snapshotable search trees, as well as some client code. We formalize our approach in the Plural tool, a sound modular typestate checking tool. We describe the challenges to verifying snapshotable trees in Plural, give an abstract interface specification against which we verify the client code, provide a concrete specification for an implementation and describe proof patterns we found. We also relate this verification approach to other techniques used to verify this data structure.

    A personal identification biometric system based on back-of-hand vein patterns

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    This report describes research on the use of back-of-hand vein patterns as a means of uniquely identifying people. In particular it describes a prototype biometric system developed by the Australian Institute of Security and Applied Technology (AISAT). This system comprises an infrared cold source, a monochrome CCD camera, a monochrome frame-grabber, a personal computer, and custom image acquisition, processing, registration, and matching software. The image processing algorithms are based on Mathematical Morphology. Registration is performed using rotation and translation with respect to the centroid of the two-dimensional domain of a hand. Vein patterns are stored as medial axis representations. Matching involves comparing a given medial axis pattern against a library of patterns using constrained sequential correlation. The matching is two-fold: a newly acquired signature is matched against a dilated library signature, and then the library signature is matched against the dilated acquired signature; this is necessary because of the positional noise exhibited by the back-of-hand veins. The results of a cross-matching experiment for a sample of 20 adults and more than 100 hand images is detailed. In addition preliminary estimates of the false acceptance rate (FAR) and false rejection rate (FRR) for the prototype system are given. Fuzzy relaxation on an association graph is discussed as an alternative to sequential correlation for the matching of vein signatures. An example is provided (including a C program) illustrating the matching process for a pair of signatures obtained from the same hand. The example demonstrates the ability of the fuzzy relaxation method to deal with segmentation errors

    Image matching of firearm fingerprints

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    A spent cartridge case exhibits characteristic markings (firearm fingerprint) that can be used to identify the type and possibly make of weapon in which the cartridge was fired. This report details research into the use of discriminant analysis for the purpose of matching spent rim-fire cartridge cases to specific make and model firearms. The discrimination and classification are based on several scalar shape parameters for the two-dimensional silhouette of the firing pin (FP) impression-- shape factor calculated from the second order moment of inertia, G factor calculated from the distance transform, and the P2A factor- as well as the distance between the centre of the cartridge case and the centroid of the FP impression, and the orientation of the principal centroidal axes associated with the FP impression. Classification results for two case studies are detailed: (i) 3 different make/model weapons producing different shaped FP impressions, and (ii) 5 different make/model weapons each producing a rectangular FP impression

    Enhanced performance by a hybrid NIRS–EEG brain computer interface

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    Noninvasive Brain Computer Interfaces (BCI) have been promoted to be used for neuroprosthetics. However, reports on applications with electroencephalography (EEG) show a demand for a better accuracy and stability. Here we investigate whether near-infrared spectroscopy (NIRS) can be used to enhance the EEG approach. In our study both methods were applied simultaneously in a real-time Sensory Motor Rhythm (SMR)-based BCI paradigm, involving executed movements as well as motor imagery. We tested how the classification of NIRS data can complement ongoing real-time EEG classification. Our results show that simultaneous measurements of NIRS and EEG can significantly improve the classification accuracy of motor imagery in over 90% of considered subjects and increases performance by 5% on average (p < 0:01). However, the long time delay of the hemodynamic response may hinder an overall increase of bit-rates. Furthermore we find that EEG and NIRS complement each other in terms of information content and are thus a viable multimodal imaging technique, suitable for BCI

    Verifying object-oriented programs with higher-order separation logic in Coq

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    We present a shallow Coq embedding of a higher-order separation logic with nested triples for an object-oriented programming language. Moreover, we develop novel specification and proof patterns for reasoning in higher-order separation logic with nested triples about programs that use interfaces and interface inheritance. In particular, we show how to use the higher-order features of the Coq formalisation to specify and reason modularly about programs that (1) depend on some unknown code satisfying a specification or that (2) return objects conforming to a certain specification. All of our results have been formally verified in the interactive theorem prover Coq

    Reshaping cortical activity with subthalamic stimulation in Parkinson's disease during finger tapping and gait mapped by near infrared spectroscopy

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    Exploration of motor cortex activity is essential to understanding the pathophysiology in Parkinson's Disease (PD), but only simple motor tasks can be investigated using a fMRI or PET. We aim to investigate the cortical activity of PD patients during a complex motor task (gait) to verify the impact of deep brain stimulation in the subthalamic nucleus (DBS-STN) by using Near-Infrared-Spectroscopy (NIRS). NIRS is a neuroimaging method of brain cortical activity using low-energy optical radiation to detect local changes in (de)oxyhemoglobin concentration. We used a multichannel portable NIRS during finger tapping (FT) and gait. To determine the signal activity, our methodology consisted of a pre-processing phase for the raw signal, followed by statistical analysis based on a general linear model. Processed recordings from 9 patients were statistically compared between the on and off states of DBS-STN. DBS-STN led to an increased activity in the contralateral motor cortex areas during FT. During gait, we observed a concentration of activity towards the cortex central area in the "stimulation-on" state. Our study shows how NIRS can be used to detect functional changes in the cortex of patients with PD with DBS-STN and indicates its future use for applications unsuited for PET and a fMRI

    Formalized Verification of Snapshotable Trees: Separation and Sharing

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    Abstract. We use separation logic to specify and verify a Java program that implements snapshotable search trees, fully formalizing the specification and verification in the Coq proof assistant. We achieve local and modular reasoning about a tree and its snapshots and their iterators, although the implementation involves shared mutable heap data structures with no separation or ownership relation between the various data. The paper also introduces a series of four increasingly sophisticated implementations and verifies the first one. The others are included as future work and as a set of challenge problems for full functional specification and verification, whether by separation logic or by other formalisms.
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