Effects of egg weight and length of storage on hatchability and subsequent growth performance of quail

This study was to investigate the effects of hatching egg weight and length of storage period on hatchability and subsequent growth performance of quail. A total of 2304 eggs was collected from a quail flock, aged 17 weeks. The eggs were divided into four groups on the basis of storage periods of 1, 3, 5 or 7 days. Prior to egg storage, the eggs in each group were classified according to egg weight, as small: 12.51 g. Hatchability of total and of fertile eggs increased significantly with an increase in egg weight but was not affected by duration of egg storage. There were no significant effects of egg storage period on body weight and feed conversion ratio of the progeny at six weeks of age. The average body weight of the quail produced from heavier eggs (large and jumbo) was significantly higher than those from the smaller eggs. It is recommended that the storage period should be no longer than 3 days. Eggs heavier than 11.50 g were found to be the most suitable for successful hatching and subsequent growth performance. Keywords: Quail, Egg weight, Storage period, Hatchability, Growth performance South African Journal of Animal Science Vol.33(4) 2003: 242-24

Dynamics of Excited Electrons in Copper: Role of Auger Electrons

Within a theoretical model based on the Boltzmann equation, we analyze in detail the structure of the unusual peak recently observed in the relaxation time in Cu. In particular, we discuss the role of Auger electrons in the electron dynamics and its dependence on the d-hole lifetime, the optical transition matrix elements and the laser pulse duration. We find that the Auger contribution to the distribution is very sensitive to both the d-hole lifetime tau_h and the laser pulse duration tau_l and can be expressed as a monotonic function of tau_l/tau_h. We have found that for a given tau_h, the Auger contribution is significantly smaller for a short pulse duration than for a longer one. We show that the relaxation time at the peak depends linearly on the d-hole lifetime, but interestingly not on the amount of Auger electrons generated. We provide a simple expression for the relaxation time of excited electrons which shows that its shape can be understood by a phase space argument and its amplitude is governed by the d-hole lifetime. We also find that the height of the peak depends on both the ratio of the optical transition matrix elements R=|M_{d \to sp}|^2/|M_{sp \to sp}|^2 and the laser pulse duration. Assuming a reasonable value for the ratio, namely R = 2, and a d-hole lifetime of tau_h=35 fs, we obtain for the calculated height of the peak Delta tau_{th}=14 fs, in fair agreement with Delta tau_{exp} \approx 17 fs measured for polycrystalline Cu.Comment: 6 pages, 6 figure

Do Newspapers Serve the State? Incumbent Party Influence on the US Press, 1869-1928

Using data from 1869 to 1928, we estimate the effect of party control of state governments on the entry, exit, circulation, prices, number of pages, and content of Republican and Democratic daily newspapers. We exploit changes over time in party control of the governorship and state legislatures in a differences-in-differences design. We exploit close gubernatorial elections and state legislatures with small majorities in a parallel regression-discontinuity design. Neither method reveals evidence that the party in power affects the partisan composition of the press. Our confidence intervals rule out modest effects, and we find little evidence of incumbent party influence even in times and places with high political stakes or low commercial stakes. The one exception is the Reconstruction South, an episode that we discuss in detail

Nonlinear lightwave circuits in chalcogenide glasses fabricated by ultrafast laser

This Letter reports a nonlinear directional waveguide coupler written by ultrafast laser in gallium lanthanum sulfide chalcogenide glass. The nonlinear waveguide device is tested with laser pulses input in two orthogonal polarizations, and all optical switching at 1040 nm between the two coupled waveguides is observed at a peak fluence of 16 GW?cm2. The spectra and autocorrelation measurement from the waveguide outputs show dominant nonlinear effects and negligible dispersion for light propagation in both channels. © 2014 Optical Society of America

Nonlinear optical localization in embedded chalcogenide waveguide arrays

We report the nonlinear optical localization in an embedded waveguide array fabricated in chalcogenide glass. The array, which consists of seven waveguides with circularly symmetric cross sections, is realized by ultrafast laser writing. Light propagation in the chalcogenide waveguide array is studied with near infrared laser pulses centered at 1040 nm. The peak intensity required for nonlinear localization for the 1-cm long waveguide array was 35.1 GW/cm 2, using 10-nJ pulses with 300-fs pulse width, which is 70 times lower than that reported in fused silica waveguide arrays and with over 7 times shorter interaction distance. Results reported in this paper demonstrated that ultrafast laser writing is a viable tool to produce 3D all-optical switching waveguide circuits in chalcogenide glass. © 2014 Author(s)

Teachers' understandings of projects and portfolios at Hacettepe University School of Foreign Languages Basic English Division

Cataloged from PDF version of article.In the last 40 years, traditional approaches in writing instruction and assessment have moved towards alternative instruction and assessment. Many institutions are going through changes to keep up with the developments in the field of ELT. Changes are generally undertaken to improve the quality of teaching both for the teachers and the students. Teachers play an important role in the changes proposed by institutions. These changes may require a change in the teachers’ practices. Teachers’ understandings of these practices play a vital role in the innovations proposed to be undertaken. The purpose of this study was to investigate teachers’ understandings of using projects and portfolios during the implementation of the new writing program at Hacettepe University School of Foreign Languages Basic English Division. By finding out the understandings of teachers towards the new writing program, its instruction and assessment tools, necessary improvements and changes can be prepared for the future of the program. iii Data was first collected through questionnaires distributed to 34 teachers in the School of Foreign Languages Basic English Division. The 40 questions in the questionnaire aimed at discovering the teachers’ interest in teaching writing, and their understandings of traditional writing assessment, projects, assessment of projects, the portfolio, and assessment of the portfolio. Secondly, in order to gather more in-depth information about the teachers’ understandings of the projects and the portfolio, interviews were conducted with five teachers and the director of the writing program. During the interviews, questions investigating the participants’ general and institutional understandings of the projects and the portfolio, and their views on the new program were asked in order to collect more in-depth information. Data collected through the questionnaire was analysed by employing descriptive statistics, such as frequencies and percentages. In order to support the results, the chi-square value of each question was also calculated using SPSS. Data collected through the interviews were analysed qualitatively through categorization. The categories were based on the research questions and grouped as teachers’ understanding of projects in general and in the institution, teachers’ understanding of the portfolio in general and in the institution, and teachers’ suggestions to improve the current writing program. The analysis of the data revealed that the teachers believe the new program is a good beginning; however, there is no clear understanding of the new writing program’s instruction and assessment tools, the project and the portfolio, or a consistent implementation of it among the staff. However, as this a new beginning, things can be improved through more in-depth teacher training.Subaşı, M. PetekM.S

Ultrafast electronic response of Ag(111) and Cu(111) surfaces: From early excitonic transients to saturated image potential

Under the terms of the Creative Commons Attribution License 3.0 (CC-BY).We investigate the evolution of attosecond to femtosecond screening and emergent potentials that govern the dynamics and energetics of electrons and holes excited in the various stages of multiphoton photoemission processes and control the photoelectron yield in recently reported experiments [X. Cui, C. Wang, A. Argondizzo, S. Garrett-Roe, B. Gumhalter, and H. Petek, Nat. Phys. 10, 505 (2014)1745-247310.1038/nphys2981]. The study is focused on the dynamical screening of holes created in preexistent quasi-two-dimensional Shockley state bands on Ag(111) and Cu(111) surfaces and of electrons excited to the intermediate and emerging screened states. Using the formalism of self-consistent electronic response, we analyze first the effects of screening on the dynamics of photoexcited electrons and holes and then of the Coulomb correlated photoexcited pair. Special attention is paid to the correlated primary electron-hole states, which commence as transient surface excitons and develop in the course of screening into uncorrelated electrons and holes propagating in the image potential and surface state bands, respectively. The obtained results enable to establish a consistent picture of transient electron dynamics at Ag(111) and Cu(111) surfaces that are becoming accessible by the time-, energy-, and momentum-resolved pump-probe multiphoton photoelectron spectroscopies.V.M.S. acknowledges partial support from the Basque Departamento de Educacion, UPV/EHU (Grant No. IT-756-13) and the Spanish Ministry od Economy and Competitiveness MINECO (Grant No. FIS2013-48286-C2-1-P). N.D. acknowledges the support of the Unity Through Knowledge Fund (UKF B1). H.P. was supported by the Division of Chemical Sciences, Geosciences and Biosciences, Office of Basic Energy Sciences of the U.S. Department of Energy through Grant DE-FG02-09ER 16056.Peer Reviewe

Dynamics of Excited Electrons in Copper and Ferromagnetic Transition Metals: Theory and Experiment

Both theoretical and experimental results for the dynamics of photoexcited electrons at surfaces of Cu and the ferromagnetic transition metals Fe, Co, and Ni are presented. A model for the dynamics of excited electrons is developed, which is based on the Boltzmann equation and includes effects of photoexcitation, electron-electron scattering, secondary electrons (cascade and Auger electrons), and transport of excited carriers out of the detection region. From this we determine the time-resolved two-photon photoemission (TR-2PPE). Thus a direct comparison of calculated relaxation times with experimental results by means of TR-2PPE becomes possible. The comparison indicates that the magnitudes of the spin-averaged relaxation time \tau and of the ratio \tau_\uparrow/\tau_\downarrow of majority and minority relaxation times for the different ferromagnetic transition metals result not only from density-of-states effects, but also from different Coulomb matrix elements M. Taking M_Fe > M_Cu > M_Ni = M_Co we get reasonable agreement with experiments.Comment: 23 pages, 11 figures, added a figure and an appendix, updated reference

Lifetime of d-holes at Cu surfaces: Theory and experiment

We have investigated the hole dynamics at copper surfaces by high-resolution angle-resolved photoemission experiments and many-body quasiparticle GW calculations. Large deviations from a free-electron-like picture are observed both in the magnitude and the energy dependence of the lifetimes, with a clear indication that holes exhibit longer lifetimes than electrons with the same excitation energy. Our calculations show that the small overlap of d- and sp-states below the Fermi level is responsible for the observed enhancement. Although there is qualitative good agreement of our theoretical predictions and the measured lifetimes, there still exist some discrepancies pointing to the need of a better description of the actual band structure of the solid.Comment: 15 pages, 7 figures, 1 table, to appear in Phys. Rev.