1,336 research outputs found
Drosophila olfactory receptors as classifiers for volatiles from disparate real world applications
Olfactory receptors evolved to provide animals with ecologically and behaviourally relevant information. The resulting extreme sensitivity and discrimination has proven useful to humans, who have therefore co-opted some animals' sense of smell. One aim of machine olfaction research is to replace the use of animal noses and one avenue of such research aims to incorporate olfactory receptors into artificial noses. Here, we investigate how well the olfactory receptors of the fruit fly, Drosophila melanogaster, perform in classifying volatile odourants that they would not normally encounter. We collected a large number of in vivo recordings from individual Drosophila olfactory receptor neurons in response to an ecologically relevant set of 36 chemicals related to wine ('wine set') and an ecologically irrelevant set of 35 chemicals related to chemical hazards ('industrial set'), each chemical at a single concentration. Resampled response sets were used to classify the chemicals against all others within each set, using a standard linear support vector machine classifier and a wrapper approach. Drosophila receptors appear highly capable of distinguishing chemicals that they have not evolved to process. In contrast to previous work with metal oxide sensors, Drosophila receptors achieved the best recognition accuracy if the outputs of all 20 receptor types were used
4135 Age and gender differences in optic disc area, cup area and vertical cup-to-discratio? The rotterdam study
Onderzoek naar risicoselectie met de basisset kwaliteitsindicatoren ziekenhuizen: op weg naar verantwoorde keuzes
Onderzoek naar risicoselectie met de basisset kwaliteitsindicatoren ziekenhuizen: op weg naar verantwoorde keuzes
Quantification of valvular regurgitation by cardiac blood pool scintigraphy: correlation with catheterization
The diagnosis of valvular regurgitation (R) is usually based on clinical signs. Quantification conventionally requires catheterization (C). We have quantified R with cardiac blood pool scintigraphy (CBPS) and compared the results with those obtained by C. Regurgitant fraction (RF) determined by C was calculated with the technique of Dodge. Forward output was measured by thermodilution or cardiogreen dilution. The RF at CBPS was obtained by the stroke index ratio (SIR) minus 1.2 divided by SIR, where SIR is the ratio of the stroke counts of left venticle over those of the right ventricle. Stroke counts are calculated directly from the time-activity curves. Each time-activity curve was obtained by drawing one region of interest around each diastolic image. The correction factor (1.2) was calculated from a large normal population. 22 patients had aortic R, 7 mitral R, 12 both, 8 patients had no evidence of regurgitation. RF of the patients with R varied from 27 to 71% (x = 42%) at C and from 26 to 74% (Y = 41%) at CBPS. Linear regression shows a good correlation coefficient (r = 0.82). The regression equation is y = 0.93x + 1.8. No correlation was found between RF (CBPS or C) and the severity of R assessed visually from angiography. In conclusion: CBPS, a non-invasive method, allows easy and repeatable determination of RF and correlates well with data obtained at catheterizatio
Acute Pancreatitis Complicated with Choledochal Duct Rupture
Recurrent acute pancreatitis is a rare clinical entity in childhood with unknown incidence (Rosendahl et al., 2007) and often occurring in a familial context. Genetic factors such as PRSS1 mutations (cationic trypsinogen gene) can be found in some patients. However, many remain idiopathic. The natural history remains poorly documented and the most frequent complications reported are pain, exocrine pancreatic insufficiency, diabetes mellitus, and pancreatic adenocarcinoma after long-standing hereditary pancreatitis. We describe a patient with hereditary pancreatitis in whom a mild pancreatitis episode was complicated by a perforation of the ductus choledochus
Compressed-domain shot boundary detection for H.264/AVC using intra partitioning maps
In this paper, a novel technique for shot boundary detection operating on H.264/AVC-compressed sequences is presented. Due to new and improved coding tools in H.264/AVC, the characteristics of the obtained sequences differ from former video coding standards. Although several algorithms working on this new standard are already proposed, the presence of IDR frames can still lead to a low accuracy for abrupt transitions. To solve this issue, we present the motion-compensated intra partitioning map which relies on the intra partitioning modes and the motion vectors present in the compressed video stream. Experimental results show that this motion-compensated map achieves a high accuracy and exceeds related work
Under-reporting bicycle accidents to police in the COST TU1101 international survey: Cross-country comparisons and associated factors
Police crash reports are often the main source for official data in many countries. However, with the exception of fatal crashes, crashes are often underreported in a biased manner. Consequently, the countermeasures adopted according to them may be inefficient. In the case of bicycle crashes, this bias is most acute and it probably varies across countries, with some of them being more prone to reporting accidents to police than others. Assessing if this bias occurs and the size of it can be of great importance for evaluating the risks associated with bicycling. This study utilized data collected in the COST TU1101 action âTowards safer bicycling through optimization of bicycle helmets and usageâ. The data came from an online survey that included questions related to bicyclists' attitudes, behaviour, cycling habits, accidents, and patterns of use of helmets. The survey was filled by 8655 bicyclists from 30 different countries. After applying various exclusion factors, 7015 questionnaires filled by adult cyclists from 17 countries, each with at least 100 valid responses, remained in our sample. The results showed that across all countries, an average of only 10% of all crashes were reported to the police, with a wide range among countries: from a minimum of 0.0% (Israel) and 2.6% (Croatia) to a maximum of a 35.0% (Germany). Some factors associated with the reporting levels were type of crash, type of vehicle involved, and injury severity. No relation was found between the likelihood of reporting and the cyclist's gender, age, educational level, marital status, being a parent, use of helmet, and type of bicycle. The significant under-reporting â including injury crashes that do not lead to hospitalization â justifies the use of self-report survey data for assessment of bicycling crash patterns as they relate to (1) crash risk issues such as location, infrastructure, cyclists' characteristics, and use of helmet and (2) strategic approaches to bicycle crash prevention and injury reduction.Fil: Shinar, D.. Ben Gurion University of the Negev; IsraelFil: Valero Mora, Pedro. Universidad de Valencia; EspañaFil: van Strijp Houtenbos, M.. Institute For Road Safety Research; PaĂses BajosFil: Haworth, N.. Queensland University of Technology; AustraliaFil: Schramm, A.. Queensland University of Technology; AustraliaFil: de Bruyne, G.. Universiteit Antwerp; BĂ©lgicaFil: Cavallo, V.. No especifĂca;Fil: Chliaoutakis, J.. No especifĂca;Fil: Pereira Dias, Joao. Instituto Superior Tecnico; PortugalFil: Ferraro, Ottavia Eleonora. Universita Degli Studi Di Pavia; ItaliaFil: Fyhri, Aslak. No especifĂca;Fil: Sajatovic, Anika Hursa. No especifĂca;Fil: Kuklane, Kalev. Lund University; SueciaFil: Ledesma, Ruben Daniel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Mar del Plata. Instituto de PsicologĂa BĂĄsica, Aplicada y TecnologĂa. Universidad Nacional de Mar del Plata. Facultad de PsicologĂa. Instituto de PsicologĂa BĂĄsica, Aplicada y TecnologĂa.; ArgentinaFil: CalvĂ© Mascarell, Oscar. Ben Gurion University of the Negev; IsraelFil: Morandi, A.. Universita Degli Studi Di Pavia; ItaliaFil: Muser, Markus. No especifĂca;Fil: Otte, Diettmar. No especifĂca;Fil: Papadakaki, M.. No especifĂca;Fil: SanmartĂn, J.. Universidad de Valencia; EspañaFil: Dulf, D.. No especifĂca;Fil: Saplioglu, M.. No especifĂca;Fil: Tzamalouka, Georgia. No especifĂca
Analytical expressions for the deprojected Sersic model
The Sersic model has become the standard to parametrize the surface
brightness distribution of early-type galaxies and bulges of spiral galaxies. A
major problem is that the deprojection of the Sersic surface brightness profile
to a luminosity density cannot be executed analytically for general values of
the Sersic index. Mazure & Capelato (2002) used the Mathematica computer
package to derive an expression of the Sersic luminosity density in terms of
the Meijer G function for integer values of the Sersic index. We generalize
this work using analytical means and use Mellin integral transforms to derive
an exact, analytical expression for the luminosity density in terms of the Fox
H function for all values of the Sersic index. We derive simplified expressions
for the luminosity density, cumulative luminosity and gravitational potential
in terms of the Meijer G function for all rational values of the Sersic index
and we investigate their asymptotic behaviour at small and large radii. As
implementations of the Meijer G function are nowadays available both in
symbolic computer algebra packages and as high-performance computing code, our
results open up the possibility to calculate the density of the Sersic models
to arbitrary precision.Comment: 9 pages, accepted for publication in Astronomy and Astrophysic
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