Consider the plane as a checkerboard, with each unit square colored black or white in an arbitrary manner. We show that for any such coloring there are straight line segments, of arbitrarily large length, such that the difference of their white length minus their black length, in absolute value, is at least the square root of their length, up to a multiplicative constant. For the corresponding ...

We determine projected rotation velocities v sin i in DAZ white dwarfs, for the first time using the rotational broadening of the Ca II K line. The results confirm previous findings that white dwarfs are very slow rotators, and set even more stringent upper limits of typically less than 10 km s−1. The few exceptions include 3 stars known or suspected to be variable ZZ Ceti stars, where the line...

a field experiment was carried out during 2001 in the experimental fields of sugar beet seed institute in karaj. the objective of this study was to determine the response of some quantitative and qualitative traits of three sugar beet lines subjected to continuous water stress and normal conditions. three sugar beet lines 7219-p.69, bp-karaj and 7112 as tolerant, semi tolerant and sensitive to ...

A survey of some recent results on nonparametric on-line estimation is presented. The first result deals with an on-line estimation for a smooth signal S(t) in the classic ‘signal plus Gaussian white noise’ model. Then an analogous on-line estimator for the regression estimation problem with equidistant design is described and justified. Finally some preliminary results related to the on-line e...

An intervention trial by Hedges and others (2001) studying 1109 cow-years, in which every lame cow was examined and recorded by a veterinary surgeon, determined the four main causes of lameness to be sole ulcers, white line disease, digital dermatitis and interdigital necrobacillosis (‘foul’ or ‘foot rot’) (see graph on the right). Sole ulcers and white line disease are defects of the hoof and,...

We apply our technique for indirect imaging of the accretion stream to the polar HU Aquarii, using eclipse prooles observed when the system was in a high accretion state. The accretion stream is relatively luminous, contributing as much or more to the overall system brightness as the accretion region on the white dwarf. We model the eclipse prooles using a model stream consisting of a ballistic...

The Bio-Breeding/Worcester (BB/W) rat develops spontaneous autoimmune diabetes similar to human insulin-dependent diabetes mellitus. Transfusions of whole blood from the nondiabetic W-line of BB/W rats prevent the syndrome in diabetes-prone recipients. We report three experiments designed to determine which blood component is protective. In all experiments, diabetes-prone BB/W rats 23 to 35 d o...

A popular interpretation of recent microlensing studies of the line of sight towards the Large Magellanic Cloud invokes a population of old white dwarf stars in the Galactic halo. Below I review the basic properties of old white dwarf stars and the ongoing efforts to detect this population directly.

Line separators are used to segregate text-lines from one another in document image analysis. Finding the separator points at every line terminal in a document image would enable text-line segmentation. In particular, identifying the separators in handwritten text could be a thrilling exercise. Obviously it would be challenging to perform this in the compressed version of a document image and t...

The discovery of very large magnetic fields in white dwarf stars and neutron stars has stimulated interest in the spectroscopy of free atoms in high magnetic fields. We review the discovery of continuum polarization in certain white dwarf stars. We discuss the interpretation of the spectra of the magnetic white dwarfs and the confirmation of the presence of large fields. We describe recent inve...