6,249 research outputs found
Clonal mixing in the soldier-producing aphid <i>Pemphigus spyrothecae</i> (Hemiptera: Aphididae)
Illuminating the genetic relationships within soldier-producing aphid colonies is an essential element of any attempt to explain the evolution of the altruistic soldier caste. Pemphigus spyrothecae is a soldier-producing aphid that induces galls on the leaf petioles of its host (trees of the genus Populus). At least a quarter of the aphids within the clonally produced gall population are morphologically and behaviourally distinct first-instar soldiers that defend the gall population from predation. Using field trapping and microsatellites, we investigated the degree of clonal mixing within natural gall populations. Field trapping in the UK showed that all the migrants of P. spyrothecae and of two other Pemphigus species were wingless first-instar soldiers. The average degree of mixing estimated from trapping P. spyrothecae migrants was 0.68% (range = 0–15%). Microsatellite genotyping of 277 aphids from 13 galls collected in Italy revealed an average mixing level of 10.4% (range = 0–59%). Six galls contained more than one clone (range = 2–5 clones). Non-kin aphids were not restricted to the soldier caste but were evenly distributed across instars. An additional gall, from which 527 occupants were genotyped, contained 12 non-kin aphids distributed among nine clones, showing that clonal diversity can be high even when mixing is very low. These observations suggest that although soldiers migrate regularly and can moult and reproduce within foreign galls, clonal mixing in this species is generally low and is unlikely to provide a barrier to the evolution of investment by the aphid clones in an altruistic soldier caste
Khotbah yang “Diurapi” oleh Roh Kudus
Pada satu sisi, setiap pengkhotbah yang rindu kuasa Roh Kudus nyata melalui khotbahnya akan bergumul untuk melihat “urapan” Roh Kudus itu. Di sisi lain, ada juga pengkhotbah-pengkhotbah yang malah takut untuk mengalami kuasa Roh Kudus dalam khotbah mereka. Seperti apakah khotbah yang “diurapi” oleh Roh Kudus itu? Mengapa juga ada para pengkhotbah malah sepertinya takut untuk mengalami kuasa Roh Kudus dalam khotbah mereka? Dan bagaimanakah menumbuhkembangkan keyakinan atau iman seseorang kepada Roh Kudus untuk berkarya melalui khotbahnya? Artikel ini berusaha menjawab pertanyaan-pertanyaan tersebut.
Kata-kata kunci: Khotbah, Urapan, Iman, Roh Kudus
English :
On the one hand, every preacher who desires to experience the power of the Holy Spirit in the sermon will struggle to see “the anointing” of the Spirit. On the other, there are preachers who even afraid of experiencing that power in their sermon. What is a Spirit-anointed sermon? Why also are there preachers who are even afraid of that anointing power? And how does a preacher nurture his/her faith in the Holy Spirit to empower a sermon? This article attempts to answer those question.
Keywords: Sermon, Anointing, Faith, Holy Spiri
Fabrication and test of a space power boiler feed electromagnetic pump. Part 2: Test facility and performance test
A three-phase helical induction electromagnetic pump, designed for the boiler-feed pump of a potassium Rankine-cycle space power system, was built and tested. The pump was tested over a range of potassium temperatures from 900 to 1400 F, flow rates from 0.75 to 4.85 lb/sec, developed pressures up to 340 psi, net positive suction heads (NPSH) from 1 to 22 psi, and NaK coolant temperatures from 800 to 950 F. The maximum efficiency at the pump design point of 3.25 lb/sec flow rate, 240 psi developed pressure, 1000 F potassium inlet temperature, and 800 F NaK coolant temperature was 16.3 percent. The tests also showed successful operation of the pump at an NPSH as low as 1.5 psi without cavitating
Radiation-reaction-induced evolution of circular orbits of particles around Kerr Black Holes
It is demonstrated that, in the adiabatic approximation, non-Equatorial
circular orbits of particles in the Kerr metric (i.e. orbits of constant
Boyer-Lindquist radius) remain circular under the influence of gravitational
radiation reaction. A brief discussion is given of conditions for breakdown of
adiabaticity and of whether slightly non-circular orbits are stable against the
growth of eccentricity.Comment: 23 pages. Revtex 3.0. Inquiries to [email protected]
Eikonal profile functions and amplitudes for and scattering
The eikonal profile function obtained from the Model of the Stochastic
Vacuum is parametrized in a form suitable for comparison with experiment. The
amplitude and the extended profile function (including imaginary and real
parts) are determined directly from the complete pp and p elastic
scattering data at high energies. Full and accurate representation of the data
is presented, with smooth energy dependence of all parameters. The changes
needed in the original profile function required for description of scattering
beyond the forward direction are described.Comment: Latex, 28 pages and 16 figure
High Energy Hadron-Nucleus Cross Sections and Their Extrapolation to Cosmic Ray Energies
Old models of the scattering of composite systems based on the Glauber model
of multiple diffraction are applied to hadron-nucleus scattering. We obtain an
excellent fit with only two free parameters to the highest energy
hadron-nucleus data available. Because of the quality of the fit and the
simplicity of the model it is argued that it should continue to be reliable up
to the highest cosmic ray energies. Logarithmic extrapolations of proton-proton
and proton-antiproton data are used to calculate the proton-air cross sections
at very high energy. Finally, it is observed that if the exponential behavior
of the proton-antiproton diffraction peak continues into the few TeV energy
range it will violate partial wave unitarity. We propose a simple modification
that will guarantee unitarity throughout the cosmic ray energy region.Comment: 8 pages, 9 postscript figures. This manuscript replaces a partial
manuscript incorrectly submitte
A Theoretical Study of Performance Measures in the Strategic and Corporate Entrepreneurships of Firms
This paper compares performance measures in the corporate and strategic entrepreneurial activities of firms. The paper develops the concepts of strategic entrepreneurship and that of corporate entrepreneurship with the aim of identifying the measures suitable for determining their “end-points” and hence, performance, with respect to the firm\u27s activities. The paper concludes the performance measures for both entrepreneurial processes need to consider and exploit the salient differences in their operations. When this is done, a “balanced” picture of the firm\u27s strategic as well as corporate entrepreneurial performance that aligns itself with the dynamic environment, operational processes and stakeholders and such that can enhance continuous improvement will be attainable
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