5,858 research outputs found
Observations of Six Glitches in PSR B1737-30
Six glitches have been recently observed in the rotational frequency of the
young pulsar PSR B1737-30 (J1740-3015) using the 25-m Nanshan telescope of
Urumqi Observatory. With a total of 20 glitches in 20 years, it is one of the
most frequently glitching pulsars of the about 1750 known pulsars. Glitch
amplitudes are very variable with fractional increases in rotation rate ranging
from 10^{-9} to 10^{-6}. Inter-glitch intervals are also very variable, but no
relationship is observed between interval and the size of the preceding glitch.
There is a persistent increase in |\dot\nu|, opposite in sign to that expected
from slowdown with a positive braking index, which may result from changes in
the effective magnetic dipole moment of the star during the glitch.Comment: 7 pages, 10 figure
A Comparison of Various Methods of Estimating Digestibility, Voluntary Intake and Average Daily Gains for Beef Cattle fed Mixed Rations
Calculating response functions in time domain with non-orthonormal basis sets
We extend the recently proposed order-N algorithms (cond-mat/9703224) for
calculating linear- and nonlinear-response functions in time domain to the
systems described by nonorthonormal basis sets.Comment: 4 pages, no figure
Partnership, ownership and control: the impact of corporate governance on employment relations
Prevailing patterns of dispersed share ownership and rules of corporate governance for UK listed companies appear to constrain the ability of managers to make credible, long-term commitments to employees of the kind needed to foster effective labour-management partnerships. We present case study evidence which suggests that such partnerships can nevertheless emerge where product market conditions and the regulatory environment favour a stakeholder orientation. Proactive and mature partnerships may also be sustained where the board takes a strategic approach to mediating between the claims of different stakeholder groups, institutional investors are prepared to take a long-term view of their holdings, and strong and independent trade unions are in a position to facilitate organisational change
The use of indigenous knowledge in development: problems and challenges
The use of indigenous knowledge has been seen by many as an alternative way of promoting development in poor rural communities in many parts of the world. By reviewing much of the recent work on indigenous knowledge, the paper suggests that a number of problems and tensions has resulted in indigenous knowledge not being as useful as hoped for or supposed. These include problems emanating from a focus on the (arte)factual; binary tensions between western science and indigenous knowledge systems; the problem of differentiation and power relations; the romanticization of indigenous knowledge; and the all too frequent decontextualization of indigenous knowledge
Optical properties of perovskite alkaline earth titanates : a formulation
In this communication we suggest a formulation of the optical conductivity as
a convolution of an energy resolved joint density of states and an
energy-frequency labelled transition rate. Our final aim is to develop a scheme
based on the augmented space recursion for random systems. In order to gain
confidence in our formulation, we apply the formulation to three alkaline earth
titanates CaTiO_3, SrTiO_3 and BaTiO_3 and compare our results with available
data on optical properties of these systems.Comment: 19 pages, 9 figures, Submitted to Journal of Physics: Condensed
Matte
Field Blue Stragglers and Related Mass Transfer Issues
This chapter contains my impressions and perspectives about the current state
of knowledge about field blue stragglers (FBS) stars, drawn from an extensive
literature that I searched. I conclude my review of issues that attend FBS and
mass transfer, by a brief enumeration of a few mildly disquieting observational
facts.Comment: Chapter 4, in Ecology of Blue Straggler Stars, H.M.J. Boffin, G.
Carraro & G. Beccari (Eds), Astrophysics and Space Science Library, Springe
Functional Locomotor Consequences of Uneven Forefeet for Trot Symmetry in Individual Riding Horses
ABSTRACT: Left-right symmetrical distal limb conformation can be an important prerequisite for a successful performance, and it is often hypothesized that asymmetric or uneven feet are important enhancing factors for the development of lameness. On a population level, it has been demonstrated that uneven footed horses are retiring earlier from elite level competition, but the biomechanical consequences are not yet known. The objectives of this study were to compare the functional locomotor asymmetries of horses with uneven to those with even feet. Hoof kinetics and distal limb kinematics were collected from horses (n = 34) at trot. Dorsal hoof wall angle was used to classify horses as even or uneven (1.5° difference between forefeet respectively) and individual feet as flat (55°). Functional kinetic parameters were compared between even and uneven forefeet using MANOVA followed by ANOVA. The relative influences of differences in hoof angle between the forefeet and of absolute hoof angle on functional parameters were analysed using multiple regression analysis (P<0.05). In horses with uneven feet, the side with the flatter foot showed a significantly larger maximal horizontal braking and vertical ground reaction force, a larger vertical fetlock displacement and a suppler fetlock spring. The foot with a steeper hoof angle was linearly correlated with an earlier braking-propulsion transition. The conformational differences between both forefeet were more important for loading characteristics than the individual foot conformation of each individual horse. The differences in vertical force and braking force between uneven forefeet could imply either an asymmetrical loading pattern without a pathological component or a subclinical lameness as a result of a pathological development in the steeper foot
CD4+ T cell activation and tolerance induction in B cell knockout mice.
B cell knockout mice microMT/microMT were used to examine the requirement for B cell antigen (Ag) presentation in the establishment of CD4+ T cell tolerance. CD4+T cells from microMT mice injected with exogenous protein Ag in adjuvant responded to in vitro challenge by transcription of cytokine mRNA, cytokine secretion, and proliferation. Peripheral tolerance could be established in microMT mice with a single dose of deaggragated protein. This tolerance was manifested by a loss of T cell proliferation and cytokine production (including both T helper cell type 1 [Th1]- and Th2-related cytokines), indicating that B cells are not required for the induction of peripheral T cell tolerance and suggesting that the dual zone tolerance theory is not applicable to all protein Ags and is not mediated through Ag presentation by B cells
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