8,430 research outputs found
Recommended from our members
Reinhard Keiser and His Opera Fredegunda : a Study in the History of Early German Opera
The purpose of this investigation is to trace briefly the development of opera in Germany during and after the Thirty Year's War as a background for the understanding of the milieu in which Keiser's Pregunda was created, and to study in detail this work as a representative of contemporary North German opera
On the reliability of linear band structure methods
We discuss an efficiency of various band structure algorithms in determining
the Fermi surface (FS) of the paramagnetic ErGa3. The linear muffin-tin orbital
(LMTO) in the atomic sphere approximation (ASA) method and three full potential
(FP) codes: FP-LMTO, FP linear augmented plane wave (FLAPW), and FP local
orbitals (FPLO) methods are employed. Results are compared with
electron-positron (e-p) momentum densities reconstructed from two dimensional
angular correlation of annihilation radiation (2D ACAR). Unexpectedly, none of
used modern FP codes is able to give satisfying description of the experimental
data that are in perfect agreement with LMTO-ASA results. We suspect that it
can be connected with a different choice of the linearization energy.Comment: 6 pages, 2 figure
Gait and Force Analysis of Provoked Pig Gait on Clean and Fouled Concrete Surfaces
Gait and force analysis have proven to be useful methods in linking claw injuries to surface material conditions. To determine the relationship between claw disorder and floor properties such as friction and surface abrasiveness, the factors controlling gait must be characterised. The effects of fouled concrete floor conditions on the gait of 10 pigs walking in a curve, using kinematics and kinetics to record gait parameters and slip frequency are described and compared with clean conditions. Pigs adapted to fouled floor conditions by reducing their walking speed and stride length, using a higher number of 3-foot support phases and by lowering diagonality. This adaption produced lower vertical forces, a twofold reduction in propulsion and outward stabilisation force and a threefold increase in braking force, without reducing the peak utilised coefficient of friction (UCOF). The UCOF values for both limbs of the curve walking pigs exceeded the recorded dynamic coefficient of friction and the corresponding UCOF values for pigs walking a straight line in fouled floor condition. As UCOF increased and available friction from the fouled floor surface decreased, this resulted in higher forward and backward slip frequency in both limbs for pigs walking in a curve. Pigs provoked to walk in a curve can adapt to fouled floor condition, but if the floor is heavily fouled this adaption is not sufficient to ensure safe walking
Recommended from our members
Direction of visual apparent motion driven solely by timing of a static sound
In temporal ventriloquism, auditory events can illusorily attract perceived timing of a visual onset [1,2,3]. We investigated whether timing of a static sound can also influence spatio-temporal processing of visual apparent motion, induced here by visual bars alternating between opposite hemifields. Perceived direction typically depends on the relative interval in timing between visual left-right and right-left flashes (e.g., rightwards motion dominating when left-to-right interflash intervals are shortest [4]). In our new multisensory condition, interflash intervals were equal, but auditory beeps could slightly lag the right flash, yet slightly lead the left flash, or vice versa. This auditory timing strongly influenced perceived visual motion direction, despite providing no spatial auditory motion signal whatsoever. Moreover, prolonged adaptation to such auditorily driven apparent motion produced a robust visual motion aftereffect in the opposite direction, when measured in subsequent silence. Control experiments argued against accounts in terms of possible auditory grouping, or possible attention capture. We suggest that the motion arises because the sounds change perceived visual timing, as we separately confirmed. Our results provide a new demonstration of multisensory influences on sensory-specific perception [5], with timing of a static sound influencing spatio-temporal processing of visual motion direction
A multivariate approach to human mate preferences
Human mate choice is complicated, with various individual differences and contextual factors influencing preferences for numerous traits. However, focused studies on human mate choice often do not capture this multivariate complexity. Here, we consider multiple factors simultaneously to demonstrate the advantages of a multivariate approach to human mate preferences. Participants (N = 689) rated the attractiveness of opposite-sex online dating profiles that were independently manipulated on facial attractiveness, perceived facial masculinity/femininity, and intelligence. Participants were also randomly instructed to either consider short- or long-term relationships. Using fitness surfaces analyses, we assess the linear and nonlinear effects and interactions of the profiles' facial attractiveness, perceived facial masculinity/femininity, and perceived intelligence on participants' attractiveness ratings. Using hierarchical linear modeling, we were also able to consider the independent contribution of participants' individual differences on their revealed preferences for the manipulated traits. These individual differences included participants' age, socioeconomic status, education, disgust (moral, sexual, and pathogen), sociosexual orientation, personality variables, masculinity, and mate value. Together, our results illuminate various previously undetectable phenomena, including nonlinear preference functions and interactions with individual differences. More broadly, the study illustrates the value of considering both individual variation and population-level measures when addressing questions of sexual selection, and demonstrates the utility of multivariate approaches to complement focused studies
Gaze following in human infants depends on communicative signals
Humans are extremely sensitive to ostensive signals, like eye contact or having their name called, that indicate someone's communicative intention toward them [1,2,3]. Infants also pay attention to these signals [4,5,6], but it is unknown whether they appreciate their significance in the initiation of communicative acts. In two experiments, we employed video presentation of an actor turning toward one of two objects and recorded infants' gaze-following behavior [7,8,9,10,11,12,13] with eye-tracking techniques [11,12]. We found that 6-month-old infants followed the adult's gaze (a potential communicative-referential signal) toward an object only when such an act is preceded by ostensive cues such as direct gaze (experiment 1) and infant-directed speech (experiment 2). Such a link between the presence of ostensive signals and gaze following suggests that this behavior serves a functional role in assisting infants to effectively respond to referential communication directed to them. Whereas gaze following in many nonhuman species supports social information gathering [14,15,16,17,18], in humans it initially appears to reflect the expectation of a more active, communicative role from the information source
What influences the speed of prototyping? An empirical investigation of twenty software startups
It is essential for startups to quickly experiment business ideas by building
tangible prototypes and collecting user feedback on them. As prototyping is an
inevitable part of learning for early stage software startups, how fast
startups can learn depends on how fast they can prototype. Despite of the
importance, there is a lack of research about prototyping in software startups.
In this study, we aimed at understanding what are factors influencing different
types of prototyping activities. We conducted a multiple case study on twenty
European software startups. The results are two folds, firstly we propose a
prototype-centric learning model in early stage software startups. Secondly, we
identify factors occur as barriers but also facilitators for prototyping in
early stage software startups. The factors are grouped into (1) artifacts, (2)
team competence, (3) collaboration, (4) customer and (5) process dimensions. To
speed up a startups progress at the early stage, it is important to incorporate
the learning objective into a well-defined collaborative approach of
prototypingComment: This is the author's version of the work. Copyright owner's version
can be accessed at doi.org/10.1007/978-3-319-57633-6_2, XP2017, Cologne,
German
Prevalence of laceration injuries in professional and amateur rugby union: a systematic review and meta-analysis
Background: Studded footwear can cause severe lacerations in rugby union; the prevalence of these injuries is currently unknown.
Objective: To summarise the skin and laceration injury prevalence in published epidemiological studies and to investigate any differences in skin injury risk between amateur and professional players.
Design: Systematic literature review and meta-analysis of epidemiological studies.
Data sources: Pubmed, Web of Science, Scopus and Ovid.
Eligibility criteria for selecting studies: Prospective, epidemiological studies published in English after 1995, measuring a minimum of 400 match or 900 training exposure hours. Participants should be adult rugby union players (amateur or professional). The study should report a separate skin or laceration injury category and provide sufficient detail to calculate injury prevalence within this category.
Results: Twelve studies were included. Mean skin injury prevalence during matches was 2.4 injuries per 1000 exposure hours; during training sessions the prevalence was 0.06 injuries per 1000 exposure hours. Skin injuries accounted for 5.3% of match injuries and 1.7% of training injuries. Skin injury risk was similar for amateur compared to professional players during matches (odds ratio: 0.63, p = 0.46.), but higher during training sessions (odds ratio: 9.24, p = 0.02).
Summary/conclusions: The skin injury prevalence of 2.4 injuries per 1000 exposure hours is equivalent to one time-loss injury sustained during matches per team, per season. Amateur players are more likely to sustain skin injuries during training sessions than professional players. There is a need for more studies observing injuries among amateur players
- …