Search results for " Navigation"
showing 10 items of 138 documents
Over-expression of two different forms of the α-secretase ADAM10 affects learning and memory in mice
2006
Members of the ADAM family (adisintegrin and metalloprotease) are the main candidates for physiologically relevant alpha-secretases. The alpha-secretase cleaves in the non-amyloidogenic pathway the amyloid precursor protein within the region of the Abeta peptides preventing their aggregation in the brain. The increase of alpha-secretase activity in the brain provides a plausible strategy to prevent Abeta formation. Concerning this possibility two transgenic mouse lines (FVB/N) have been created: mice over-expressing the bovine form of the alpha-secretase (ADAM10) and mice over-expressing an inactive form of the alpha-secretase (ADAM10-E348A-HA; ADAM10-dn). For behavioral examination a F1 ge…
Long-term effects of delayed motherhood in mice on postnatal development and behavioural traits of offspring
2003
BACKGROUND: Some epidemiological evidence tentatively suggests that children born to older parents may have lower intellectual development and maturity than children whose parents are younger. This study aims to analyse the long-term effects of delayed motherhood in mice on postnatal development and behavioural traits later in life. METHODS: Hybrid females, either at the age of 10 weeks or 51 weeks, were individually housed with a randomly selected 12-14 week old hybrid male. After a postweaning resting period of 1 week, dams were caged again with a new randomly selected 12-14 week old male. This sequence of events was repeated until old females reached the end of their reproductive life. R…
Intraoperative Navigation in der Chirurgie der Nasennebenhöhlen und der vorderen Schädelbasis
2002
Hintergrund und Fragestellung. Beim Einsatz der computerassistierten Chirurgie im Bereich der Nasennebenhohlen und vorderen Schadelbasis sind einige Fehlerquellen zu beachten, die durch physikalische Gesetze, den technischen Entwicklungs- und individuellen Kenntnisstand des Anwenders bedingt sind. Patienten/Methodik. Anhand unserer Erfahrungen von 436 navigationsunterstutzten Eingriffen werden Hard- und Softwarefehler, Fehler der Bildgebung und des -transfers, Fehler der Patientenregistrierung, Anwenderfehler und strategische Fehler analysiert. Ergebnisse. Bei optischen CAS-Systemen fuhrt die Blockade des Sichtfeldes der Kamera zu Funktionseinschrankungen, wahrend elektromagnetische Systeme…
Fehlerquellen der Navigation in der lateralen Sch�delbasischirurgie
2003
Die Identifikation moglicher Storfaktoren navigationsunterstutzter Eingriffe an der lateralen Schadelbasis ermoglichen dem Anwender die Vermeidung und Behebung dieser Fehler. Anhand unserer Erfahrungen von 85 navigationsunterstutzten Eingriffen im Bereich der lateralen Schadelbasis werden Fehler der Hard- und Software, der Bildgebung und des -transfers, der Patientenregistrierung, durch den Anwender und solche strategischer Art analysiert. Bei optischen CAS-Systemen fuhrt eine Blockade des Sichtfelds der Kameras zu Funktionsbeschrankungen, wahrend elektromagnetische Systeme durch ferromagnetisch aktive Materialien beeinflusst werden konnen. Die bisherigen Verfahren der Patientenregistrierun…
Do Sign Language Videos Improve Web Navigation for Deaf Signer Users?
2010
The efficacy of video-based sign language (SL) navigation aids to improve Web search for Deaf Signers was tested by two experiments. Experiment 1 compared 2 navigation aids based on text hyperlinks linked to embedded SL videos, which differed in the spatial contiguity between the text hyperlink and SL video (contiguous vs. distant). Deaf Signers’ performance was similar in Web search using both aids, but a positive correlation between their word categorization abilities and search efficiency appeared in the distant condition. In Experiment 2, the contiguous condition was compared with a text-only hyperlink condition. Deaf Signers became less disorientated (used shorter paths to find the tar…
Hybrid nonlinear observer for Inertial Navigation
2016
This paper considers the problem of designing an observer for navigation and localization of inertial systems. Since the measurement systems used in this field have a low update rate with respect to the control algorithm, the design of a suitable observer with sampled measurements is required. Here a hybrid non-linear observer is proposed, combining two different observers with different characteristics. A theoretical treatment is given in order to prove the convergence of the observer and it will be contextualized in the framework of the hybrid systems, providing an elegant setting for the proposed solution. Finally experimental results show the feasibility of the proposed observer and the…
Locating Objects Away from Earth Surface: Positioning Accuracy
2013
The motion of the Galileo and GPS satellite constellations is simulated in Schwarzschild space-time, whereas photons travel in Minkowski space-time. This is a good enough approach to deal with the main goal of this paper: the study of positioning accuracy in the framework of the so-called relativistic positioning. Our study is based on numerical 4D simulations. In this meeting, the contribution of J.A. Morales-Lladosa contains some basic ideas which have been important to perform our numerical calculations. For four chosen emitters (satellites) of a certain constellation, many receivers located at different distances from Earth surface and in distinct directions are considered. Thus, we ver…
Universally Designed Beacon-Assisted Indoor Navigation for Emergency Evacuations
2019
International audience; The United Nations (UN) Convention on the Rights of Persons with Disabilities (CRPD) obligates national governments to ensure the protection and safety of persons with disabilities in emergency situations. This article examines the application and accessibility of state-of-the-art ICT solutions in emergency situations. Research has indeed shown that the design and implementation of evacuation procedures in emergency situations play a critical role in ensuring personal safety and protection. While research has examined the experiences of persons including persons with disabilities in emergency situations, research has yet to examine fully the role that cutting-edge in…
Kuģa vraka aizvākšanas tiesības zemūdens kultūras mantojuma aizsardzības kontekstā
2017
Promocijas darbā tiek padziļināti pētīta kuģošanas tiesību nozare un tās vēsturiskā attīstība Latvijā, un kuģošanas tiesību galvenā objekta – kuģa un ar tā vraka aizvākšanu saistītās tiesības zemūdens kultūras mantojuma aizsardzības kontekstā, kā arī tiek pievērsta uzmanība vraku aizvākšanas tiesiskajam regulējumam attiecībā uz kuģošanas drošību un jūras vides aizsardzību. Tiek analizēts kuģu vraku tiesiskais regulējums Latvijas Republikas nacionālajos tiesību aktos, ārvalstu tiesībās un starptautiskajos līgumos ar mērķi pilnveidot kuģu vraku aizvākšanas normatīvi tiesisko regulējumu Latvijas Republikā, lai nodrošinātu drošu kuģošanu, jūras vides aizsardzību un zemūdens kultūras mantojuma a…
The "Laparoscopic Neuro-Navigation" -- LANN: from a functional cartography of the pelvic autonomous neurosystem to a new field of laparoscopic surgery
2006
It is the objective of this study to etablish the technique of laparoscopic exposure of all pelvic somatic and autonomous nerves. In all our patients who underwent a laparoscopic surgical approach of the retroperitoneum, exposure and assessment of the exposed nerves using laparoscopic neuro-navigation were performed. Laparoscopic surgery allows the surgical approach to all pelvic nerves, particularly to the sciatic nerve, the pudendal nerve and the splanchnic pelvic nerves. We describe a cartography of the functional anatomy of the pelvic plexus and elaborate on the concept of "laparoscopic pelvic functional surgery". © 2004 Taylor & Francis.