991 research outputs found
statistics of vertical backscatter profiles of cirrus clouds
Abstract. A nearly global statistical analysis of vertical backscatter and extinction profiles of cirrus clouds collected by the CALIOP lidar, on-board of the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation, is presented. Statistics on frequency of occurrence and distribution of bulk properties of cirrus clouds in general and, for the first time, of horizontally homogeneous (on a 5-km field of view) cirrus clouds only are provided. Annual and seasonal backscatter profiles (BSP) are computed for the horizontally homogeneous cirri. Differences found in the day/night cases and for midlatitudes and tropics are studied in terms of the mean physical parameters of the clouds from which they are derived. The relationship between cloud physical parameters (optical depth, geometrical thickness and temperature) and the shape of the BSP is investigated. It is found that cloud geometrical thickness is the main parameter affecting the shape of the mean CALIOP BSP. Specifically, cirrus clouds with small geometrical thicknesses show a maximum in mean BSP curve located near cloud top. As the cloud geometrical thickness increases the BSP maximum shifts towards cloud base. Cloud optical depth and temperature have smaller effects on the shape of the CALIOP BSPs. In general a slight increase in the BSP maximum is observed as cloud temperature and optical depth increase. In order to fit mean BSPs, as functions of geometrical thickness and position within the cloud layer, polynomial functions are provided. The impact on satellite radiative transfer simulations in the infrared spectrum when using either a constant ice-content (IWC) along the cloud vertical dimension or an IWC profile derived from the BSP fitting functions is evaluated. It is, in fact, demonstrated that, under realistic hypotheses, the mean BSP is linearly proportional to the IWC profile
Two-Particle Schroedinger Equation Animations of Wavepacket-Wavepacket Scattering (revised)
A simple and explicit technique for the numerical solution of the
two-particle, time-dependent Schr\"{o}dinger equation is assembled and tested.
The technique can handle interparticle potentials that are arbitrary functions
of the coordinates of each particle, arbitrary initial and boundary conditions,
and multi-dimensional equations. Plots and animations are given here and on the
World Wide Web of the scattering of two wavepackets in one dimension.Comment: 13 pages, 8 figures, animations at
http://nacphy.physics.orst.edu/ComPhys/PACKETS
The paradoxical role of emotional intensity in the perception of vocal affect
Vocalizations including laughter, cries, moans, or screams constitute a potent source of information about the affective states of others. It is typically conjectured that the higher the intensity of the expressed emotion, the better the classification of affective information. However, attempts to map the relation between affective intensity and inferred meaning are controversial. Based on a newly developed stimulus database of carefully validated non-speech expressions ranging across the entire intensity spectrum from low to peak, we show that the intuition is false. Based on three experiments (Nâ=â90), we demonstrate that intensity in fact has a paradoxical role. Participants were asked to rate and classify the authenticity, intensity and emotion, as well as valence and arousal of the wide range of vocalizations. Listeners are clearly able to infer expressed intensity and arousal; in contrast, and surprisingly, emotion category and valence have a perceptual sweet spot: moderate and strong emotions are clearly categorized, but peak emotions are maximally ambiguous. This finding, which converges with related observations from visual experiments, raises interesting theoretical challenges for the emotion communication literature
Terragni sono io!
Testo ufficiale letto prima della cerimonia della consegna del Diploma Honoris Causa all'architetto americano Peter Eisenman
Total orthotopic small bowel transplantation in swine under FK 506
Previous experimental studies in rodents and in dogs have established the efficacy of FK 506 in controlling the immunologic events following small bowel or multivisceral transplantation.1â5 To complete the assessment of FK 506 in experimental small bowel transplantation, we present here our experience with the frequently used swine model
Perception of Nigerian DĂčndĂșn talking drum performances as speech-like vs. music-like: The role of familiarity and acoustic cues
It seems trivial to identify sound sequences as music or speech, particularly when the sequences come from different sound sources, such as an orchestra and a human voice. Can we also easily distinguish these categories when the sequence comes from the same sound source? On the basis of which acoustic features? We investigated these questions by examining listenersâ classification of sound sequences performed by an instrument intertwining both speech and music: the dĂčndĂșn talking drum. The dĂčndĂșn is commonly used in south-west Nigeria as a musical instrument but is also perfectly fit for linguistic usage in what has been described as speech surrogates in Africa. One hundred seven participants from diverse geographical locations (15 different mother tongues represented) took part in an online experiment. Fifty-one participants reported being familiar with the dĂčndĂșn talking drum, 55% of those being speakers of YorĂčbĂĄ. During the experiment, participants listened to 30 dĂčndĂșn samples of about 7s long, performed either as music or YorĂčbĂĄ speech surrogate (n = 15 each) by a professional musician, and were asked to classify each sample as music or speech-like. The classification task revealed the ability of the listeners to identify the samples as intended by the performer, particularly when they were familiar with the dĂčndĂșn, though even unfamiliar participants performed above chance. A logistic regression predicting participantsâ classification of the samples from several acoustic features confirmed the perceptual relevance of intensity, pitch, timbre, and timing measures and their interaction with listener familiarity. In all, this study provides empirical evidence supporting the discriminating role of acoustic features and the modulatory role of familiarity in teasing apart speech and music
Brexit: Modes of Uncertainty and Futures in an Impasse
Alongside the emergence of various populisms, Brexit and other contemporary geopolitical events have been presented as symptomatic of a generalizing and intensifying sense of uncertainty in the midst of a crisis of (neo)liberalism. In this paper we describe what kind of event Brexit is becoming in the impasse between the UKâs EU referendum in 2016 and its anticipated exit from the EU in 2019. Based on 108 interviews with people in the NorthâEast of England, we trace how Brexit is variously enacted and felt as an end, advent, a harbinger of worse to come, nonâevent, disaster, and betrayed promise. By following how these incommensurate versions of Brexit take form and coâexist we supplement explanatory and predictive approaches to the geographies of Brexit and exemplify an approach that traces what such geopolitical events become. Specifically, we use the concept of âmodes of uncertaintyâ as a way of discerning patterns in how present uncertainties are lived. A âmode of uncertaintyâ is a shared set of practices animated by a distinctive mood through which futures are made present and felt. Rather than treat uncertainty as a static, explanatory context, we thus follow how different versions of Brexit are constituted through specific âmodes of (un)certaintyâ â negative hope, national optimisms, apprehensive hopefulness and fantasies of action â that differentiate within a seemingly singular, shared sense of uncertainty
The DĂčndĂșn Drum helps us understand how we process speech and music
Every day, you hear many sounds in your environment, like speech, music, animal calls, or passing cars. How do you tease apart these unique categories of sounds? We aimed to understand more about how people distinguish speech and music by using an instrument that can both âspeakâ and play music: the dĂčndĂșn talking drum. We were interested in whether people could tell if the sound produced by the drum was speech or music. People who were familiar with the dĂčndĂșn were good at the task, but so were those who had never heard the dĂčndĂșn, suggesting that there are general characteristics of sound that define speech and music categories. We observed that music is faster, more regular, and more variable in volume than âspeech.â This research helps us understand the interesting instrument that is dĂčndĂșn and provides insights about how humans distinguish two important types of sound: speech and music
Poly (ethyl 2-cyanoacrylate) nanoparticles (PECA-NPs) as possible agents in tumor treatment
Tumor eradication has many challenges due to the difficulty of selectively delivering anticancer drugs to malignant cells avoiding contact with healthy tissues/organs. The improvement of antitumor efficacy and the reduction of systemic side effects can be achieved using drug loaded nanoparticles. In this study, poly (ethyl 2-cyanoacrylate) nanoparticles (PECA-NPs) were prepared using an emulsion polymerization method and their potential for cancer treatment was investigated. The size, polydispersity index and zeta potential of prepared nanoparticles are about 80 nm, 0.08 and â39.7 mV, respectively. The stability test shows that the formulation is stable for 15 days, while an increase in particle size occurs after 30 days. TEM reveals the spherical morphology of nanoparticles; furthermore, FTIR and 1 H NMR analyses confirm the structure of PECA-NPs and the complete polymerization. The nanoparticles demonstrate an in vitro concentration-dependent cytotoxicity against human epithelial colorectal adenocarcinoma cell lines (Caco-2), as assessed by MTT assay. The anticancer activity of PECA-NPs was studied on 3D tumor spheroids models of hepatocellular carcinoma (HepG2) and kidney adenocarcinoma cells (A498) to better understand how the nanoparticles could interact with a complex structure such as a tumor. The results confirm the antitumor activity of PECA-NPs. Therefore, these systems can be considered good candidates in tumor treatment
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