Let H be an ample line bundle on a non-singular projective surface X , and M(H) the coarse moduli scheme of rank-two H-semistable sheaves with fixed Chern classes on X . We show that if H changes and passes through walls to get closer to KX , then M(H) undergoes natural flips with respect to canonical divisors. When X is minimal and κ(X) ≥ 1, this sequence of flips terminates in M(HX); HX is an...

We discuss the feasibility of the detection of the 21 cm forest in the diffuse intergalactic medium (IGM) with the radio telescope LOFAR. The optical depth to the 21 cm line has been derived using simulations of reionization which include detailed radiative transfer of ionizing photons. We find that the spectra from reionization models with similar total comoving hydrogen ionizing emissivity bu...

We present Chandra X-ray images of Tycho’s supernova remnant that delineate its outer shock as a thin, smooth rim along the straight northeastern edge and most of the circular western half. The images also show that the Si and S ejecta are highly clumpy, and have reached near the forward shock at numerous locations. Most of the X-ray spectra that we examine along the rim show evidence of line e...

The existence of a Kähler form give strong topological constraints via Hodge theory. Can we get similar constraints on algebraic maps? Let f : X → Y a proper morphism. Our goal is going to be to linearize the problem. For this lecture, we will assume f is projective and smooth, to simplify the problem. In fact, we will assume X and Y are nonsingular. So our map factors X → P × Y → Y and df is s...

Chandra X-ray imaging spectroscopy of the nearby Herbig Ae star HD 163296 at 100 AU angular resolution is reported. A point-like, soft (kT∼0.5 keV), emission-line source is detected at the location of the star with an X-ray luminosity of 4 × 10 ergs s (logLX/Lbol = −5.48). In addition, faint emission along the direction of a previously-detected Lyα-emitting jet and Herbig-Haro outflow may be pr...

This paper describes a method to enhance line structures in a gray level image. For this purpose, we blur the image using anisotropic gaussian filters along the directions of each line structures. In a line structure region the gradients of image gray levels have a uniform direction. To find such line structures, we evaluate the uniformity of the directions of the local gradients. Before this e...

for values of x > 0. For values of x < 0, if r is an integer then one can employ the solution given by eq. (2) without modification. If r is not an integer, then one can obtain the solution from eq. (2) by analytic continuation in the complex plane. In particular, for non-integer r there is a branch point at x = 0 and it is convenient to choose the branch cut to lie along the negative real axis...

poor stand establishment of canola (brassica napus l.) under flatland mechanized planting and crust-forming soil is a major problem for farmers in central iran. previous research there showed that irrigated cotton emergence on crust-forming soils under flatland planting can be significantly improved using a double-disk planter with zero-pressure press wheel tires and no crust-breaking. in that ...

Background and objectives: Because of the importance of breast cancer as a first cause of morbidity and mortality among females, also the limitation of chemotherapy and based on literature of the use of herbal medicines against cancer, the current study was aimed to determine the efficacy of Berbers vulgaris fruit ethanol extract against MCF-7 breast cancer cell line. ...