519 research outputs found
Untersuchungen zu Fütterung, Milchleistung und Tiergesundheit von Milchkühen im Ökologischen Landbau
The breeding scheme entails yield differences of more than 2 000 kg energy corrected milk (ECM) per cow and year. On average, farms feeding less concentrate yielded slightly lower milk yields per cow and year, however, because of the longer productive life the cows showed similar milk yields over their lifetime. The farms investigated so far appeared to have healthy cows, even if fed low levels of concentrates or in the case of extremely low or high urea contents in the milk. These values could indicate the cows’ ability to compensate for short-dated changes
Kraftfuttergaben und Milchleistung bei Weidegang von Milchviehherden im ökologischen Landbau
During grazing, the efficiency of concentrate feeding on milk yields is low, especially when white clover is present in the sward (Wilkens et al., 1994). Clover in animal feed
enhances forage intake; feeding trials have shown increased intake rates by 15-30 % (Paul, 2003). These results are of special interest for organic farms, where clover has
a higher impact on the farming system. In the experimental organic farm of the Landwirtschaftskammer Nordrhein-Westfalen (Haus Riswick) the concentrate rate fed during grazing time showed no influence upon milk yields (2,6 resp.4,7 kg DM concentrate/ animal/day). In agreement with these results a three years investigation on 89 organic farms in Northwest Germany showed no effect of concentrate feeding on milk yield during the grazing season.
Furthermore, a reduction or increase of concentrate rates during the grazing season did not show any differences in animal health so far
A Virtual Conversational Agent for Teens with Autism: Experimental Results and Design Lessons
We present the design of an online social skills development interface for
teenagers with autism spectrum disorder (ASD). The interface is intended to
enable private conversation practice anywhere, anytime using a web-browser.
Users converse informally with a virtual agent, receiving feedback on nonverbal
cues in real-time, and summary feedback. The prototype was developed in
consultation with an expert UX designer, two psychologists, and a pediatrician.
Using the data from 47 individuals, feedback and dialogue generation were
automated using a hidden Markov model and a schema-driven dialogue manager
capable of handling multi-topic conversations. We conducted a study with nine
high-functioning ASD teenagers. Through a thematic analysis of post-experiment
interviews, identified several key design considerations, notably: 1) Users
should be fully briefed at the outset about the purpose and limitations of the
system, to avoid unrealistic expectations. 2) An interface should incorporate
positive acknowledgment of behavior change. 3) Realistic appearance of a
virtual agent and responsiveness are important in engaging users. 4)
Conversation personalization, for instance in prompting laconic users for more
input and reciprocal questions, would help the teenagers engage for longer
terms and increase the system's utility
Interaction of Stored, Cooled Proton Beams with Fiber Targets
This research was sponsored by the National Science Foundation Grant NSF PHY-931478
Spin Correlation Coefficients in pp-->pnpi+ from 325 to 400 MeV
The spin correlation coefficient combinations Axx + Ayy, Axx - Ayy and the
analyzing powers Ay(theta) were measured for pp-->pnpi+ at beam energies of
325, 350, 375 and 400 MeV. A polarized internal atomic hydrogen target and a
stored, polarized proton beam were used. These polarization observables are
sensitive to contributions of higher partial waves. A comparison with recent
theoretical calculations is provided.Comment: 8 Pages, 1 Table, 5 Figures. Accepted for publication in Phys. Lett.
Cross section and analyzing power of pol{p}p -> pn pi+ near threshold
The cross section and analyzing power of the pol{p}p -> pn pi+ reaction near
threshold are estimated in terms of data obtained from the pol{p}p -> d pi+ and
pp -> pp pi0 reactions. A simple final state interaction theory is developed
which depends weakly upon the form of the pion-production operator and includes
some Coulomb corrections. Within the uncertainties of the model and the input
data, the approach reproduces well the measured energy dependence of the total
cross section and the proton analyzing power at a fixed pion c.m. angle of
90deg, from threshold to T_p = 330 MeV. The variation of the differential cross
section with pion angle is also very encouraging.Comment: 20 pages, Latex including 4 eps figure
Recoil-Ion Detection System
This research was sponsored by the National Science Foundation Grant NSF PHY-931478
Differential Cross Section and Analyzing Power of p(p,pi+)d Near Threshold
This research was sponsored by the National Science Foundation Grant NSF PHY-931478
Photofission of heavy nuclei at energies up to 4 GeV
Total photofission cross sections for 238U, 235U, 233U, 237Np, 232Th, and
natPb have been measured simultaneously, using tagged photons in the energy
range Egamma=0.17-3.84 GeV. This was the first experiment performed using the
Photon Tagging Facility in Hall B at Jefferson Lab. Our results show that the
photofission cross section for 238U relative to that for 237Np is about 80%,
implying the presence of important processes that compete with fission. We also
observe that the relative photofission cross sections do not depend strongly on
the incident photon energy over this entire energy range. If we assume that for
237Np the photofission probability is equal to unity, we observe a significant
shadowing effect starting below 1.5 GeV.Comment: 4 pages of RevTex, 6 postscript figures, Submitted to Phys. Rev. Let
Emergent global oscillations in heterogeneous excitable media: The example of pancreatic beta cells
Using the standard van der Pol-FitzHugh-Nagumo excitable medium model I
demonstrate a novel generic mechanism, diversity, that provokes the emergence
of global oscillations from individually quiescent elements in heterogeneous
excitable media. This mechanism may be operating in the mammalian pancreas,
where excitable beta cells, quiescent when isolated, are found to oscillate
when coupled despite the absence of a pacemaker region.Comment: See home page http://lec.ugr.es/~julya
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