1,025 research outputs found
Effektivität und histologische Auswertung von Gewebeproben nach Bearbeitung mit einem 445nm Halbleiterlaser
Bei Gewebeinzisionen mit einem 445nm Halbleiterlaser wird eine effektive Schnittführung mit räumlich begrenzter Hitzewirkung beschrieben. Daher war das Ziel der vorliegenden Studie die histologische Beurteilung von Gewebeproben nach Inzision mit einem 445nm Diodenlaser.
Vierzig Mukosalappen aus dem Vestibulum von zwanzig Schweinekiefern wurden präpariert, die anschließend auf den Träger einer mechanischen Lineareinheit gespannt wurden. Das Handstück eines HF-Chirurgie-Geräts, 970nm- und 445nm Halbleiterlasers wurde auf dem Verfahrschlitten der Lineareinheit befestigt, so dass alle Gewebeinzisionen mit gleicher Geschwindigkeit und im gleichen Abstand von der Gewebeoberfläche durchgeführt werden konnten. Auf den jeweils zwei Mukosalappen eines Kiefers wurden acht Inzisionen durchgeführt: (I-III): 445nm Laser ohne konditionierte Spitze, 90°, mit Gewebekontakt bei 1, 2 und 4W, (IV-V): 445nm Laser ohne konditionierte Spitze, 90°, ohne Kontakt (1mm) zum Gewebe bei 2 und 4W cw, (VI): 445nm Laser ohne konditionierte Spitze, 45°, mit Kontakt zum Gewebe bei 2W cw, (VII): 970nm Laser mit konditionierter Spitze, 90°, mit Gewebekontakt bei 3W cw, (VIII): HF-Chirurgie-Gerät mit gerader Spitze, 90°, mit Gewebekontakt bei 50W. Die histologische Auswertung erfolgte nach H.E.-Färbung der eingebetteten Präparate bei 35-facher Vergrößerung.
Der Vergleich der Inzisionstiefen zeigte einen signifikanten Unterschied in Abhängigkeit von der Laserwellenlänge und den gewählten Laserparametern. Dabei konnte die größte Inzisionstiefe mit dem 445nm Laser im direkten Gewebekontakt mit einer Leistungseinstellung von 2W erreicht werden (p<0,05). Die geringste Inzisionstiefe wurde nach Verwendung des HF-Chirurgie-Geräts gemessen.
Bei Verwendung eines 445nm Halbleiterlasers kann im Vergleich zu einem 970nm Diodenlaser und einem Elektrotom mit einer höheren Schneideffizienz gerechnet werden. Auch eine Anwendung im Nicht-Kontakt-Modus zeigt klinisch akzeptable Inzisionstiefen ohne Anzeichen ausgedehnter Nekrosezonen
The Predictive Power of Social Media Sentiment for Short-Term Stock Movements
Ever since modern-day financial markets existed, people have been trying to forecast movements in stock prices, as accurate predictions would entail economic benefits and the reduction of risks. This paper examines whether social media sentiment can be used to predict short-term stock movements. Using more than two years of data from Twitter, we assess the effect the extracted sentiment holds for 10 companies listed in the S&P500. Applying different sentiment analysis approaches and forecasting models, we find that for three out of the ten companies, sentiment does significantly improve the forecasting performance. A custom-built sentiment model outperforms an off-the-shelf VADER model, and tree-based models deliver better performance than linear ones. On the theoretical front, this provides evidence against the Efficient Market Hypothesis and warrants future research regarding the circumstances under which stock returns might be predictable
The highly rearranged mitochondrial genomes of the crabs Maja crispata and Maja squinado (Majidae) and gene order evolution in Brachyura
Abstract
We sequenced the mitochondrial genomes of the spider crabs Maja crispata and Maja squinado (Majidae, Brachyura). Both genomes contain the whole set of 37 genes characteristic of Bilaterian genomes, encoded on both \u3b1- and \u3b2-strands. Both species exhibit the same gene order, which is unique among known animal genomes. In particular, all the genes located on the \u3b2-strand form a single block. This gene order was analysed together with the other nine gene orders known for the Brachyura. Our study confirms that the most widespread gene order (BraGO) represents the plesiomorphic condition for Brachyura and was established at the onset of this clade. All other gene orders are the result of transformational pathways originating from BraGO. The different gene orders exhibit variable levels of genes rearrangements, which involve only tRNAs or all types of genes. Local homoplastic arrangements were identified, while complete gene orders remain unique and represent signatures that can have a diagnostic value. Brachyura appear to be a hot-spot of gene order diversity within the phylum Arthropoda. Our analysis, allowed to track, for the first time, the fully evolutionary pathways producing the Brachyuran gene orders. This goal was achieved by coupling sophisticated bioinformatic tools with phylogenetic analysis
UAVs for Industries and Supply Chain Management
This work aims at showing that it is feasible and safe to use a swarm of
Unmanned Aerial Vehicles (UAVs) indoors alongside humans. UAVs are increasingly
being integrated under the Industry 4.0 framework. UAV swarms are primarily
deployed outdoors in civil and military applications, but the opportunities for
using them in manufacturing and supply chain management are immense. There is
extensive research on UAV technology, e.g., localization, control, and computer
vision, but less research on the practical application of UAVs in industry. UAV
technology could improve data collection and monitoring, enhance
decision-making in an Internet of Things framework and automate time-consuming
and redundant tasks in the industry. However, there is a gap between the
technological developments of UAVs and their integration into the supply chain.
Therefore, this work focuses on automating the task of transporting packages
utilizing a swarm of small UAVs operating alongside humans. MoCap system, ROS,
and unity are used for localization, inter-process communication and
visualization. Multiple experiments are performed with the UAVs in wander and
swarm mode in a warehouse like environment.Comment: Accpeted at the XXIV INTERNATIONAL CONFERENCE ON "MATERIAL HANDLING,
CONSTRUCTIONS AND LOGISTICS
Hardy's inequality for functions vanishing on a part of the boundary
We develop a geometric framework for Hardy's inequality on a bounded domain
when the functions do vanish only on a closed portion of the boundary.Comment: 26 pages, 2 figures, includes several improvements in Sections 6-8
allowing to relax the assumptions in the main results. Final version
published at http://link.springer.com/article/10.1007%2Fs11118-015-9463-
Possibility of electric arc detection in power transformers by directly embedded photoconductive elements in the transformer tank
In this article, an application of potential light-sensitive semiconductive elements, including photoresistors and photodiodes as electric arc detection sensors in the transformer tank, is comprehensively investigated. Conventionally, a Buchholz relay (BHR) is implemented for arc fault detection in power transformers. Unfortunately, in some cases, the tripping of the transformer
is not fast enough in order to prevent a tank rupture and catastrophic collateral damages. Therefore, an application of light-sensitive elements as optical sensors is investigated for detecting an arc inside a transformer tank faster under various operational conditions. This contribution focuses on the performance of sensors, which are inserted in the transformer tank. Apart from consideration of different factors such as stochastic nature of light in the arc, thermal cycling, the distance effect on the light sensitivity and possibility of light reflection by the tank, challenges and limitations of arc sensing with light sensors in the mentioned approach are comprehensively discussed. The deficiencies and limitations of the arc sensors are revealed through the experimental investigations conducted
Development of a virtual reality simulation for exposure based addiction therapy
After the success of virtual reality (VR) applications in supporting exposure-based and psychoeducational cognitive behavioural therapy for various mental illnesses, the technology is also gaining traction in addiction medicine. This paper will describe the concept behind a custom-developed VR simulation for this application with a particular emphasis on alcohol-related addictive disorders. Using Unreal Engine 4, an exposure simulation and a scenario for learning and applying coping strategies were developed for the Oculus Quest. Because of the common association of supermarkets with the procurement of alcohol among addicts, a small shop was implemented as initial scenario. Since the feeling of presence is an important parameter in the quality assessment of a simulation, the degree of immersion was evaluated in initial practical tests after development. In surveys with ten healthy testers, the majority showed a feeling of immersion. Cybersickness and unrealistic collision physics were identified as disruptive factors to the extent of immersion. This work provides the basis for a novel concept for addiction therapy which focusses on a fusion of playful psychoeducation, adjustable exposure, and the internalization of coping strategies with the help of multisensory biofeedback as well as the documentation of the objective physiological measurements for assessment of therapy success. The aim is to best possible address the specific requirements for clinical and home use in terms of self-containment, immersion, and ease of use. To evaluate and exploit the scientific potential of this concept scientific studies and technical improvements to both simulation and hardware are required
Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at s√=8 TeV with the ATLAS detector
The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1fb−1 of proton–proton collision data at √s = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via t˜→tχ˜01 or t˜→ bχ˜±1 →bW(∗)χ˜01 , where χ˜01 (χ˜±1 ) denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction of t˜ → tχ˜01 . For a branching fraction of 100%, top squark masses in the range 270–645 GeV are excluded for χ˜01 masses below 30 GeV. For a branching fraction of 50% to either t˜ → tχ˜01 or t˜ → bχ˜±1 , and assuming the χ˜±1 mass to be twice the χ˜01 mass, top squark masses in the range 250–550 GeV are excluded for χ˜01 masses below 60 GeV
Potential effects of oilseed rape expressing oryzacystatin-1 (OC-1) and of purified insecticidal proteins on larvae of the solitary bee Osmia bicornis
Despite their importance as pollinators in crops and wild plants, solitary bees have not previously been included in non-target testing of insect-resistant transgenic crop plants. Larvae of many solitary bees feed almost exclusively on pollen and thus could be highly exposed to transgene products expressed in the pollen. The potential effects of pollen from oilseed rape expressing the cysteine protease inhibitor oryzacystatin-1 (OC-1) were investigated on larvae of the solitary bee Osmia bicornis (= O. rufa). Furthermore, recombinant OC-1 (rOC-1), the Bt toxin Cry1Ab and the snowdrop lectin Galanthus nivalis agglutinin (GNA) were evaluated for effects on the life history parameters of this important pollinator. Pollen provisions from transgenic OC-1 oilseed rape did not affect overall development. Similarly, high doses of rOC-1 and Cry1Ab as well as a low dose of GNA failed to cause any significant effects. However, a high dose of GNA (0.1%) in the larval diet resulted in significantly increased development time and reduced efficiency in conversion of pollen food into larval body weight. Our results suggest that OC-1 and Cry1Ab expressing transgenic crops would pose a negligible risk for O. bicornis larvae, whereas GNA expressing plants could cause detrimental effects, but only if bees were exposed to high levels of the protein. The described bioassay with bee brood is not only suitable for early tier non-target tests of transgenic plants, but also has broader applicability to other crop protection products
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