613 research outputs found
Charging of highly resistive granular metal films
We have used the Scanning Kelvin probe microscopy technique to monitor the
charging process of highly resistive granular thin films. The sample is
connected to two leads and is separated by an insulator layer from a gate
electrode. When a gate voltage is applied, charges enter from the leads and
rearrange across the sample. We find very slow processes with characteristic
charging times exponentially distributed over a wide range of values, resulting
in a logarithmic relaxation to equilibrium. After the gate voltage has been
switched off, the system again relaxes logarithmically slowly to the new
equilibrium. The results cannot be explained with diffusion models, but most of
them can be understood with a hopping percolation model, in which the
localization length is shorter than the typical site separation. The technique
is very promising for the study of slow phenomena in highly resistive systems
and will be able to estimate the conductance of these systems when direct
macroscopic measurement techniques are not sensitive enough.Comment: 8 pages, 7 figure
Weakly uniformly rotund Banach spaces
summary:The dual space of a WUR Banach space is weakly K-analytic
Correction coefficients of distortion and vibration period for buildings due to soil-structure interaction
The present research analyzed the influence of the soil structure interaction (SSI) in buildings, varying geotechnical parameters and height, considering 3 international codes. The responses obtained from the structures taking into account the SSI, were compared with the responses of fixed-base buildings, being the main control variables: the period and the drift. It was determined that the estimated range in which the period of the structure increases is from 30 to 98%, demonstrating the influence of considering soil flexibility. Due to the variability of the responses obtained, an adjustment factor is proposed to predict said amplification of the control variables, depending on the height of the building and the ground
Modelling and identification of an autonomous surface vehicle
This work aims to provide technical information regarding the identification and modelling of the Yellowfish Autonomous Surface Vehicle (ASV) developed at Universidad Loyola Andalucía. The goal is to have a simple model of the vehicle that can be later exploited for estimation and control, either as an individual vessel, or as part of a coordinated fleet.Peer Reviewe
Acoustic characteristics of vocalisations emitted by the domestic rabbit (Oryctolagus cuniculus) during copula ejaculation and electro-ejaculation with or without anaesthesia
[EN] Vocalisations can be used as reliable indicators of pain, but little information is available in rabbits, where acoustic tools for farming environments can be used for welfare judgements. The aim of this study was to compare vocalisations produced during copula ejaculation and electro-ejaculation (EE), with or without general anaesthesia, in domestic rabbits. Vocalisations of nine New Zealand white adult males were digitally recorded. The number of males vocalising and vocal characteristics including high, low, maximum and fundamental frequencies and duration of the vocalisations were analysed. There were no differences in the number of males vocalising or any vocalisation parameter between the 1st and 2nd ejaculation while copulating, even though the fundamental frequency increased in all males in the 2nd ejaculation (P=0.008). More males vocalised while mating than while being electro-ejaculated (P=0.03), and all vocalisation parameters were greater during EE than while mating (P=0.004). The use or not of anaesthesia during EE did not modify any of the parameters evaluated. It was concluded that: 1) more males vocalised during copula ejaculation than while being electro-ejaculated; 2) bio-acoustic analysis allowed us to identify aversive utterance vocalisations, which are characterised with higher frequencies, that those from non-aversive stimulus; and 3) at least with the anaesthetic combination and the responses studied, anaesthesia had no effect on the acoustic characteristics of the vocalisation emitted during EE in rabbits.Orihuela, A.; Ungerfeld, R. (2019). Acoustic characteristics of vocalisations emitted by the domestic rabbit (Oryctolagus cuniculus) during copula ejaculation and electro-ejaculation with or without anaesthesia. World Rabbit Science. 27(3):157-162. https://doi.org/10.4995/wrs.2019.10809SWORD157162273Abril-Sánchez S., Freitas-de-Melo A., Damián, J.P., Giriboni J., Villagrá-García A., Ungerfeld R. 2017. Ejaculation does not contribute to the stress response to electroejaculation in sheep. Reprod. Domest. Anim., 52: 403-408. https://doi.org/10.1111/rda.12922Abril-Sánchez S., Crosignani N., Freitas-de-Melo A., Terrazas A., Damián J.P., Beracochea R., Silveira P., Ungerfeld R. 2018. Sedation or anaesthesia decrease the stress response to eletroejacuation and improve the quality of the collected semen in goat bucks. Animal, 12: 2598-2608. https://doi.org/10.1017/s1751731118000320Aguirre F.V., Vázquez R.R., Hallal C.C., Orihuela A., Flores S.M., Flores P.I. 2015. Stress induced by electro-ejaculation in domestic rabbits. XXIV Congress of the Latin American Association of Animal Production. November 9-13. Puerto Varas, Chile. pp. 271.Cools R., Roberts A.C., Robbins T.W. 2008. Serotoninergic regulation of emotional and behavioural control processes. Trends Cogn. Sci., 12: 31-40. https://doi.org/10.1016/j.tics.2007.10.011da Silva Cordeiro A., Näs I.D., Oliveira S., Violaro F., Almeida A.D., Neves D. 2013. Understanding vocalization might help to assess stressful conditions in piglets. Animals, 3: 923-934. https://doi.org/10.3390/ani3030923Damián J.P., Ungerfeld R. 2011. The stress response of frequently electroejaculated rams to electroejaculation: hormonal, physiological, biochemical, haematological and behavioural parameters. Reprod. Domest. Anim., 46: 646-650. https://doi.org/10.1111/j.1439-0531.2010.01722.xDamián J.P., Ungerfeld R. 2010. Vocalizations are reliable indicators of pain during electroejaculation in rams. In Proc.: 44th Congress of the International Society for Applied Ethology, 4-7, August, Uppsala, Sweden, pp.184.Dawkins M.S. 1998. Evolution and animal welfare. Q. Rev. Biol., 73: 305-328.Donovan J., Brown P. 1998. Anesthesia. Curr. Protoc. Immunol., 27: 141-145.Fumagalli F., Damián J.P., Ungerfeld R. 2015. Vocalizations during electroejaculation in anaesthetized adult and young Pampas Deer (Ozotoceros bezoarticus) males. Reprod. Domest. Anim., 50: 321-326. https://doi.org/10.1111/rda.12494Giuliano F., Allard J. 2001. Dopamine and Male Sexual Function. Eur. Urol., 40: 601-608. https://doi.org/10.1159/000049844Hull E.M., Muschamp J.W., Sato S. 2004. Dopamine and serotonin: influences on male sexual behavior. Physiol. Behav., 83: 291-307. https://doi.org/10.1016/s0031-9384(04)00357-9Jürgens U. 1979. Vocalization as an emotional indicator a Neuroethological Study in the Squirrel Monkey. Behaviour, 69: 88-117.Manteuffel G., Puppe B., Schön P.C. 2004. Vocalization of farm animals as a measure of welfare. Appl. Anim. Behav. Sci., 88: 163-182. https://doi.org/10.1016/j.applanim.2004.02.012Morton E.S. 1977. On the occurrence and significance of motivation-structural rules in some birds and mammals sound. Am. Nat., 111: 855-869. https://doi.org/10.1086/283219Ohl, D.A., 1993. Electroejaculation. Urol. Clin. North Am., 20: 181-188.Orihuela A., Aguirre V., Hernández C., Flores-Pérez I., Vázquez R. 2009a. Effect of Anesthesia on Welfare Aspects of Hair Sheep (Ovis aries) During Electro-Ejaculation. J. Anim. Vet. Adv., 8: 305-308.Orihuela A., Aguirre V., Hernández C., Flores-Pérez I., Vázquez R. 2009b. Ejaculation on the Serum Cortisol Response, Heart and Respiratory Rates in Hair Sheep (Ovis aries). J. Anim. Vet. Adv., 8: 1968-1972.Seyfart R.M., Cheney D.L. 2003. Meaning and emotion in animal vocalizations. Annals of the New York Academy of Sciences 1000: 32-55.Watts J.M., Stookey J.M. 1999. Effects of restraint and branding on rates and acoustic parameters of vocalization in beef cattle. Appl. Anim. Sci., 62: 125-135. https://doi.org/10.1016/s0168-1591(98)00222-6Watts J.M., Stookey J.M. 2000. Vocal behaviour in cattle: the animal's commentary on its biological processes and welfare. Appl. Anim. Behav. Sci., 67: 15-33. https://doi.org/10.1016/s0168-1591(99)00108-2White R.G., DeShazer J.A., Tressler C.J., Borcher G.M., Davey S., Waninge A., Parkhurst A.M., Milanuk M.J., Clemens E.T. 1995. Vocalization and physiological response of pigs during castration with or without a local anesthetic. J. Anim. Sci., 73: 381-386. https://doi.org/10.2527/1995.732381
Visual gaze patterns reveal surgeons' ability to identify risk of bile duct injury during laparoscopic cholecystectomy
BACKGROUND: Bile duct injury is a serious surgical complication of laparoscopic cholecystectomy. The aim of this study was to identify distinct visual gaze patterns associated with the prompt detection of bile duct injury risk during laparoscopic cholecystectomy. METHODS: Twenty-nine participants viewed a laparoscopic cholecystectomy that led to a serious bile duct injury ('BDI video') and an uneventful procedure ('control video') and reported when an error was perceived that could result in bile duct injury. Outcome parameters include fixation sequences on anatomical structures and eye tracking metrics. Surgeons were stratified into two groups based on performance and compared. RESULTS: The 'early detector' group displayed reduced common bile duct dwell time in the first half of the BDI video, as well as increased cystic duct dwell time and Calot's triangle glances count during Calot's triangle dissection in the control video. Machine learning based classification of fixation sequences demonstrated clear separability between early and late detector groups. CONCLUSION: There are discernible differences in gaze patterns associated with early recognition of impending bile duct injury. The results could be transitioned into real time and used as an intraoperative early warning system and in an educational setting to improve surgical safety and performance
Compactness in Banach space theory - selected problems
We list a number of problems in several topics related to compactness in
nonseparable Banach spaces. Namely, about the Hilbertian ball in its weak
topology, spaces of continuous functions on Eberlein compacta, WCG Banach
spaces, Valdivia compacta and Radon-Nikod\'{y}m compacta
Quantitative analysis of multi-spectral fundus images
We have developed a new technique for extracting histological parameters from multi-spectral images of the ocular fundus. The new method uses a Monte Carlo simulation of the reflectance of the fundus to model how the spectral reflectance of the tissue varies with differing tissue histology. The model is parameterised by the concentrations of the five main absorbers found in the fundus: retinal haemoglobins, choroidal haemoglobins, choroidal melanin, RPE melanin and macular pigment. These parameters are shown to give rise to distinct variations in the tissue colouration. We use the results of the Monte Carlo simulations to construct an inverse model which maps tissue colouration onto the model parameters. This allows the concentration and distribution of the five main absorbers to be determined from suitable multi-spectral images. We propose the use of "image quotients" to allow this information to be extracted from uncalibrated image data. The filters used to acquire the images are selected to ensure a one-to-one mapping between model parameters and image quotients. To recover five model parameters uniquely, images must be acquired in six distinct spectral bands. Theoretical investigations suggest that retinal haemoglobins and macular pigment can be recovered with RMS errors of less than 10%. We present parametric maps showing the variation of these parameters across the posterior pole of the fundus. The results are in agreement with known tissue histology for normal healthy subjects. We also present an early result which suggests that, with further development, the technique could be used to successfully detect retinal haemorrhages
Participation of the oviductal s100 calcium binding protein G in the genomic effect of estradiol that accelerates oviductal embryo transport in mated rats
<p>Abstract</p> <p>Background</p> <p>Mating changes the mechanism by which E2 regulates oviductal egg transport, from a non-genomic to a genomic mode. Previously, we found that E2 increased the expression of several genes in the oviduct of mated rats, but not in unmated rats. Among the transcripts that increased its level by E2 only in mated rats was the one coding for an s100 calcium binding protein G (s100 g) whose functional role in the oviduct is unknown.</p> <p>Methods</p> <p>Herein, we investigated the participation of s100 g on the E2 genomic effect that accelerates oviductal transport in mated rats. Thus, we determined the effect of E<sub>2 </sub>on the mRNA and protein level of s100 g in the oviduct of mated and unmated rats. Then, we explored the effect of E<sub>2 </sub>on egg transport in unmated and mated rats under conditions in which s100 g protein was knockdown in the oviduct by a morpholino oligonucleotide against s100 g (s100 g-MO). In addition, the localization of s100 g in the oviduct of mated and unmated rats following treatment with E<sub>2 </sub>was also examined.</p> <p>Results</p> <p>Expression of <it>s100 g </it>mRNA progressively increased at 3-24 h after E2 treatment in the oviduct of mated rats while in unmated rats <it>s100 g </it>increased only at 12 and 24 hours. Oviductal s100 g protein increased 6 h following E<sub>2 </sub>and continued elevated at 12 and 24 h in mated rats, whereas in unmated rats s100 g protein increased at the same time points as its transcript. Administration of a morpholino oligonucleotide against <it>s100 g </it>transcript blocked the effect of E<sub>2 </sub>on egg transport in mated, but not in unmated rats. Finally, immunoreactivity of s100 g was observed only in epithelial cells of the oviducts of mated and unmated rats and it was unchanged after E2 treatment.</p> <p>Conclusions</p> <p>Mating affects the kinetic of E2-induced expression of s100 g although it not changed the cellular localization of s100 g in the oviduct after E<sub>2 </sub>. On the other hand, s100 g is a functional component of E2 genomic effect that accelerates egg transport. These findings show a physiological involvement of s100 g in the rat oviduct.</p
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