RX J1643.7+3402: a new bright cataclysmic variable

We report the discovery of a new bright (V$\sim$12.6) cataclysmic variable star identified with the ROSAT X-ray source RX J1643.7+3402. Spectroscopic and photometric observations show it to be a novalike variable sharing some of the characteristics of the SW Sex sub-class of novalike CVs. The spectroscopic period may be either 2\fh575 or 2\fh885, within the period "gap." A photometric modulation with a probable period of 2\fh595 and an amplitude of $\sim$ 0.1 mag in V is present on most nights and could be either a "positive" or a "negative" superhump modulation (depending on the exact spectroscopic period), indicating the presence of a precessing accretion disk in this system. Rapid variations of 0.1 to 0.2 mag amplitude in V repeat with a time scale of $\sim$ 15 min

A Large Outbreak of Hepatitis E Among a Displaced Population in Darfur, Sudan, 2004: The Role of Water Treatment Methods.

BACKGROUND: The conflict in Darfur, Sudan, was responsible for the displacement of 1.8 million civilians. We investigated a large outbreak of hepatitis E virus (HEV) infection in Mornay camp (78,800 inhabitants) in western Darfur. METHODS: To describe the outbreak, we used clinical and demographic information from cases recorded at the camp between 26 July and 31 December 2004. We conducted a case-cohort study and a retrospective cohort study to identify risk factors for clinical and asymptomatic hepatitis E, respectively. We collected stool and serum samples from animals and performed a bacteriological analysis of water samples. Human samples were tested for immunoglobulin G and immunoglobulin M antibody to HEV (for serum samples) and for amplification of the HEV genome (for serum and stool samples). RESULTS: In 6 months, 2621 hepatitis E cases were recorded (attack rate, 3.3%), with a case-fatality rate of 1.7% (45 deaths, 19 of which involved were pregnant women). Risk factors for clinical HEV infection included age of 15-45 years (odds ratio, 2.13; 95% confidence interval, 1.02-4.46) and drinking chlorinated surface water (odds ratio, 2.49; 95% confidence interval, 1.22-5.08). Both factors were also suggestive of increased risk for asymptomatic HEV infection, although this was not found to be statistically significant. HEV RNA was positively identified in serum samples obtained from 2 donkeys. No bacteria were identified from any sample of chlorinated water tested. CONCLUSIONS: Current recommendations to ensure a safe water supply may have been insufficient to inactivate HEV and control this epidemic. This research highlights the need to evaluate current water treatment methods and to identify alternative solutions adapted to complex emergencies

Optically bright Active Galactic Nuclei in the ROSAT-Faint Source Catalogue

To build a large, optically bright, X-ray selected AGN sample we have correlated the ROSAT-FSC catalogue of X-ray sources with the USNO catalogue limited to objects brighter than O=16.5 and then with the APS database. Each of the 3,212 coincidences was classified using the slitless Hamburg spectra. 493 objects were found to be extended and 2,719 starlike. Using both the extended objects and the galaxies known from published catalogues we built up a sample of 185 galaxies with O_APS < 17.0 mag, which are high-probability counterparts of RASS-FSC X-ray sources. 130 galaxies have a redshift from the literature and for another 34 we obtained new spectra. The fraction of Seyfert galaxies in this sample is 20 %. To select a corresponding sample of 144 high-probability counterparts among the starlike sources we searched for very blue objects in an APS-based color-magnitude diagram. Forty-one were already known AGN and for another 91 objects we obtained new spectra, yielding 42 new AGN, increasing their number in the sample to 83. This confirms that surveys of bright QSOs are still significantly incomplete. On the other hand we find that, at a flux limit of 0.02 count /-1 and at this magnitude, only 40 % of all QSOs are detected by ROSAT.Comment: 17 pages, 16 figures, accepted by A&

Catalog of Radio Galaxies with z>0.3. I:Construction of the Sample

The procedure of the construction of a sample of distant ($z>0.3$) radio galaxies using NED, SDSS, and CATS databases for further application in statistical tests is described. The sample is assumed to be cleaned from objects with quasar properties. Primary statistical analysis of the list is performed and the regression dependence of the spectral index on redshift is found.Comment: 9 pages, 6 figures, 2 table

Результаты комбинированного антиангиогенного воздействия на новообразованные сосуды роговицы. экспериментально-морфологическое исследование

Results of comparative experimental and morphological study of activity on corneal neovascularization in rabbit’s eye of photodynamic therapy with Photosense and antiangiogenic therapy with Avastin (bevacizumab) alone, and in its combination are represented. The treatment was performed in regimens: 1) photodynamic therapy with Photosense (single intravenous injection in dose of 0.3 mg/kg 72 h prior to laser irradiation, power density of irradiation 500 mW/cm2, wavelength 675 nm); 2) drug antiangiogenic therapy with Avastin (single subconjuctival introduction at dose of 1.25 mg); 3) photodynamic therapy with Photosense (in described regimen) in combination with subconjuctival introduction of Avastin at dose of 1.25 mg immediately prior to irradiation. Combined photodynamic therapy with antiangiogenic therapy allows to obtain almost complete occlusion in all regions of corneal neovascular bed with shorter time interval comparing with those for monoregimens. In case of blood flow retention in great vessels courses of combined modality treatment may be repeated. The absence of side-effects on surrounding tissues and the recovery of optical characteristics of cornea may allow to use this upcoming method in clinical practice. Приведены результаты сравнительного экспериментально-морфологического исследования влияния на новообразованные сосуды роговицы глаза кролика фотодинамической терапии с препаратом фотосенс и медикаментозной антиангиогенной терапии с препаратом авастин (бевацизумаб) в режиме монотерапии, а также их сочетанного применения. Лечение проводили в режимах: 1) фотодинамическая терапия с препаратом фотосенс (однократное внутривенное введение в дозе 0,3 мг/кг за 72 ч до лазерного облучения, плотность мощности лазерного облучения 500 мВт/см2, длина волны 675 нм); 2) медикаментозная анти- ангиогенная терапия с препаратом авастин (однократное субконьюнктивальное введение в дозе 1,25 мг); 3) фотодинамическая терапия с препаратом фотосенс (в указанном режиме) в сочетании с субконьюнктивальным введением препарата авастин в дозе 1,25 мг непосредственно перед проведением облучения. Показано, что при сочетанном применении фотодинамической и антиогенной терапии можно добиться практически полной окклюзии во всех отделах новообразованного сосудистого русла роговицы, причем в более короткий промежуток времени по сравнению со временем лечения в монорежимах. В случае сохранения кровотока в крупных магистральных сосудах возможно проведение повторных курсов комбинированного лечения. Отсутствие побочного воздействия на окружающие ткани и восстановление оптических свойств роговицы возможно позволит в перспективе использовать предложенный метод в клинической практике.

Prevalence of Hepatitis E Virus in Swine Fed on Kitchen Residue

The aim of this study was to investigate the prevalence of swine hepatitis E virus (HEV) in pigs fed different feedstuffs (kitchen residue or mixed feeds) and genetic identification of HEV isolated in Hebei province, China. Serum and fecal samples were collected from adult swine. Anti-HEV antibody was evaluated by double sandwich antigen enzyme immunoassay. HEV RNA was extracted from fecal samples and amplified by nested RT-PCR. The reaction products were sequenced, and the sequence analyzed. Virus-like particles were distinguishable by negative staining in the electron microscope. Histopathological observation and immunohistochemical localization were used in the animal models. Overall, the anti-HEV positive percentage of serum samples from pigs fed on kitchen residue was 87.10% (27/31), and 53.06% (130/245) from pigs fed on complete feed. The HEV RNA positivity rate of fecal samples from pigs fed on kitchen residue was 61.54% (8/13), but zero for pigs fed on complete feed. Sequence analysis of these eight samples and comparison with the published sequence showed that there were eight groups that belonged to genotype 4 d and the nucleotide identity was 95.6–99.3%. swHE11 is most closely related to strain CCC220, and the other seven HEV isolates were most closely related to strains swGX40, SwCH189 and V0008ORF3, which are isolates from human and pigs. Histopathological observation showed that there was liver damage in the experimental group, and immunohistochemistry indicated that the HEV antigens were strongly positive at 7 days after infection. The results demonstrated that the prevalence of HEV in pigs fed on kitchen residue was higher than in those fed on complete feed (P<0.05)

Superhumps in Cataclysmic Binaries. XXIV. Twenty More Dwarf Novae

We report precise measures of the orbital and superhump period in twenty more dwarf novae. For ten stars, we report new and confirmed spectroscopic periods - signifying the orbital period P_o - as well as the superhump period P_sh. These are GX Cas, HO Del, HS Vir, BC UMa, RZ Leo, KV Dra, KS UMa, TU Crt, QW Ser, and RZ Sge. For the remaining ten, we report a medley of P_o and P_sh measurements from photometry; most are new, with some confirmations of previous values. These are KV And, LL And, WX Cet, MM Hya, AO Oct, V2051 Oph, NY Ser, KK Tel, HV Vir, and RX J1155.4-5641. Periods, as usual, can be measured to high accuracy, and these are of special interest since they carry dynamical information about the binary. We still have not quite learned how to read the music, but a few things are clear. The fractional superhump excess epsilon [=(P_sh-P_o)/P_o] varies smoothly with P_o. The scatter of the points about that smooth curve is quite low, and can be used to limit the intrinsic scatter in M_1, the white dwarf mass, and the mass-radius relation of the secondary. The dispersion in M_1 does not exceed 24%, and the secondary-star radii scatter by no more than 11% from a fixed mass-radius relation. For the well-behaved part of epsilon(P_o) space, we estimate from superhump theory that the secondaries are 18+-6% larger than theoretical ZAMS stars. This affects some other testable predictions about the secondaries: at a fixed P_o, it suggests that the secondaries are (compared with ZAMS predictions) 40+-14% less massive, 12+-4% smaller, 19+-6% cooler, and less luminous by a factor 2.5(7). The presence of a well-defined mass-radius relation, reflected in a well-defined epsilon(P_o) relation, strongly limits effects of nuclear evolution in the secondaries.Comment: PDF, 62 pages, 7 tables, 21 figures; accepted, in press, to appear November 2003, PASP; more info at http://cba.phys.columbia.edu