Developing Keywords Using Automated Clustering of Event Descriptions

This study investigated the use of automated clustering of event descriptions as a tool for developing a keyword taxonomy for a database product. Automatically-generated cluster labels were translated into keywords and domain experts reviewed the keywords alongside corresponding event descriptions. The experts evaluated the keywords for a) relevance to the event descriptions and b) goodness or use value as keywords. The results show that the keywords performed better in terms of goodness than in terms of relevance. In addition, data mining techniques showed that many of the keywords correlated closely with classifications already in use for the database

Risk Factors of Sexual Assault Victimization within the U.S. Military

INTRODUCTION: Sexual assault (SA) victimization affects thousands of service members in the military each year and identifying risk factors of SA is essential to inform prevention efforts. AIM: To synthesize literature on SA within the military to determine risk factors of SA incidence. METHODS: Risk factors from 6 epidemiological studies were compared via meta-analysis using R. Odds ratios and tests of heterogeneity were calculated to illustrate the collective odds of SA given each risk factor across the studies and to show variability. Odds ratios were calculated separately for risk factors only mentioned in one study. RESULTS: Women (OR =16.37), persons reporting sexual harassment during service (OR = 14.54), persons with a SA history (OR = 3.99), enlisted rank (OR = 2.47), non-married persons (OR = 2) and persons with no college experience were at greater risk of SA (OR = 1.32). Being White was found to be a protective factor (OR = 0.76). Our descriptive analysis found that experiencing stalking (OR = 11.84), being a sexual minority (OR = 2.15) or transgender increased the risk of SA (OR = 1.91). However, transgender womxn were at lower risk of SA than transgender mxn (OR = 0.42). DISCUSSION: It may be useful to develop tailored prevention programs for those identified as at risk according to our findings. Further, more needs to be done to address the environmental and cultural factors specific to the military that perpetuate SA incidence

Mechanical properties of the rigid and hydrostatic skeletons of molting blue crabs, Callinectes sapidus Rathbun

Molting in crustaceans involves significant changes in the structure and function of the exoskeleton as the old cuticle is shed and a new one is secreted. The flimsy new cuticle takes several days to harden and during this time crabs rely on a hydrostatic skeletal support system for support and movement. This change from a rigid to a hydrostatic skeletal support mechanism implies correlated changes in the function, and thus mechanical properties, of the cuticle. In particular, it must change from primarily resisting compression, bending and torsional forces to resisting tension. This study was designed to explore the changes in the mechanical properties of the crustacean cuticle as the animals switch between two distinct skeletal support mechanisms. Samples of cuticle were removed from blue crabs

Auditory cortical responses in the cat to sounds that produce spatial illusions

Humans and cats can localize a sound source accurately if its spectrum is fairly broad and flat(1-3), as is typical of most natural sounds. However, if sounds are filtered to reduce the width of the spectrum, they result:in illusions of sources that are very different from the actual locations, particularly in the up/down and front/back dimensions(4-6). Such illusions reveal that the auditory system relies on specific characteristics of sound spectra to obtain cues for localization(7). In the-auditory cortex of cats, temporal firing patterns of neurons can signal the locations of broad-band sounds(8-9). Here we show that such spike patterns systematically mislocalize sounds that have been passed through a narrow-band filter. Both correct and incorrect locations signalled by neurons can be predicted quantitatively by a model of spectral processing that also predicts correct and incorrect localization judgements by human listeners(6). Similar cortical mechanisms, if present in humans, could underlie human auditory spatial perception.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62778/1/399688a0.pd

MetaMesh: A hierarchical computational model for design and fabrication of biomimetic armored surfaces

Many exoskeletons exhibit multifunctional performance by combining protection from rigid ceramic components with flexibility through articulated interfaces. Structure-to-function relationships of these natural bioarmors have been studied extensively, and initial development of structural (load-bearing) bioinspired armor materials, most often nacre-mimetic laminated composites, has been conducted. However, the translation of segmented and articulated armor to bioinspired surfaces and applications requires new computational constructs. We propose a novel hierarchical computational model, MetaMesh, that adapts a segmented fish scale armor system to fit complex “host surfaces”. We define a “host” surface as the overall geometrical form on top of which the scale units are computed. MetaMesh operates in three levels of resolution: (i) locally—to construct unit geometries based on shape parameters of scales as identified and characterized in the Polypterus senegalus exoskeleton, (ii) regionally—to encode articulated connection guides that adapt units with their neighbors according to directional schema in the mesh, and (iii) globally—to generatively extend the unit assembly over arbitrarily curved surfaces through global mesh optimization using a functional coefficient gradient. Simulation results provide the basis for further physiological and kinetic development. This study provides a methodology for the generation of biomimetic protective surfaces using segmented, articulated components that maintain mobility alongside full body coverage.Massachusetts Institute of Technology. Institute for Soldier Nanotechnologies (Contract No. W911NF-13-D-0001)United States. Army Research Office (Institute for Collaborative Biotechnologies (ICB), contract no. W911NF-09-D-0001)United States. Department of Defense (National Security Science and Engineering Faculty Fellowship Program (Grant No. N00244-09-1-0064)

The locomotor system of the ocean sunfish Mola mola (L.): role of gelatinous exoskeleton, horizontal septum, muscles and tendons

Adult ocean sunfish are the heaviest living teleosts. They have no axial musculature or caudal fin. Propulsion is by unpaired dorsal and anal fins; a pseudocaudal fin (‘clavus’) acts as a rudder. Despite common perception, young sunfish are active predators that swim quickly, beating their vertical fins in unison to generate lift‐based propulsion and attain cruising speeds similar to salmon and marlin. Here we show that the thick subcutaneous layer (or ‘capsule’), already known to provide positive buoyancy, is also crucial to locomotion. It provides two compartments, one for dorsal fin musculature and one for anal fin muscles, separated by a thick, fibrous, elastic horizontal septum that is bound to the capsule itself, the roof of the skull and the dorsal surface of the short vertebral column. The compartments are braced sagittally by bony haemal and neural spines. Both fins are powered by white muscles distributed laterally and red muscles located medially. The anal fin muscles are mostly aligned dorso‐ventrally and have origins on the septum and haemal spines. Dorsal fin muscles vary in orientation; many have origins on the capsule above the skull and run near‐horizontally and some bipennate muscles have origins on both capsule and septum. Such bipennate muscle arrangements have not been described previously in fishes. Fin muscles have hinged tendons that pass through capsular channels and radial cartilages to insertions on fin rays. The capsule is gelatinous (89.8% water) with a collagen and elastin meshwork. Greasy in texture, calculations indicate capsular buoyancy is partly provided by lipid. Capsule, septum and tendons provide elastic structures likely to enhance muscle action and support fast cruising

THE MECHANICS OF FISH SKIN: LACK OF AN "EXTERNAL TENDON" ROLE IN TWO TELEOSTS

Volume: 171Start Page: 236End Page: 24

Supraleitende Niob-Tunnelkontakte und ihre Verwendung als Strahlungsdetektoren

Supraleitende Tunnelkontakte eignen sich zur Verwendung als Teilchen- und Strahlungsdetektoren mit hoher Energieaufloesung. Die Bestrahlung mit Elektronen im Tieftemperatur-Rasterelektronenmikroskop (TTREM) erlaubt die Untersuchung der Detektoreigenschaften mit hoher raeumlicher und zeitlicher Aufloesung. Nb/AlO_x/Nb-Tunnelkontakte unterschiedlicher Geometrie wurden mit Elektronen einer Energie von 6-35 keV im TTREM bestrahlt. Bei der Bestrahlung mit Elektronen niedriger Energie war das Detektorsignal der Proben raeumlich homogen, waehrend bei der Verwendung von hoeherenergetischen Elektronen das beobachtete Signal mit dem Strahlort variierte. In zeitaufgeloesten Bestrahlungsexperimenten wurde die effektive Quasiteilchen-Lebensdauer in Nb/AlO_x/Nb-Tunnelkontakten im Temperaturbereich von 2.6 - 4.5 K bestimmt. Die gemessenen Zeiten lagen zwischen 51 ns und 231 ns und hingen von der Qualitaet der Proben ab. Fuer Tunnelkontakte mit normalleitenden Leckstroemen war die Lebensdauer der Quasiteilchen erniedrigt. Die minimale Energie, die zur Anregung und zum Nachweis eines zusaetzlichen Quasiteilchens notwendig war, wurde durch Integration des zeitaufgeloesten Detektorsignals bestimmt und betrug 15.9 meV. Durch die Realisierung von sehr kurzen Strahlpulsen konnten im TTREM erstmals Einzelelektronen nachgewiesen werden. (orig./MM)Superconducting tunnel junctions are suitable for uses as high-resolution particle and radiation detectors. Irradiation with electrons in the low-temperature scanning electron microscope is a method ensuring high local and temporal resolutions in investigations of their detecting properties. Nb/AlO_x/Nb tunnel junctions with varying geometric characteristics were irradiated with electrons from the 6 - 35 keV energy range using the low-temperature scanning electron microscope. During the irradiation with low-energy electrons the detector signals of the tested samples remained uninfluenced by local factors, while they varied according to irradiaton sites in tests using electrons of a higher energy. During time-independent irradiation experiments the actual life-span of quasi-particles in Nb/AlO_x/Nb tunnel junctions was determined at temperatures between 2.6 and 4.5 K. The measure life-spans ranged from 51 ns to 231 ns and were seen to be linked to the quality of the samples. Life-spans of quasi-particles were seen to be reduced for tunnel junctions showing flux creep of normal conductivity. The minimum amount of energy needed to excite and detect an additional quasi-particle, determined in this study by integration of the time-independent detector signal, was 15.9 mev. Owing to the availability of extremely short radiation pulses individual electrons could for the first time be detected in the low-temperature scanning electron microscope. (orig./MM)SIGLEAvailable from TIB Hannover: H94B419 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman