Increasing a Telescope's Field of View, and Subsequent Observations of Edge-On Galaxies NGC 4244 and NGC 5907

Abstract

ABSTRACT. A unique focal reducer for the Steward Observatory 2.3-m Ritchey-Chretien telescope on Kitt Peak was designed and built. It increased the field of view on a Loral 2048X2048 charged-coupled device (CCD) with 15 fim pixels from about 5' X5' to 24'X24'. The inverted-Cassegrainian, two-mirror design permits high efficiency of UV wavelengths and good broad-band image quality from 3500 to 8500 Â without significant chromatic aberrations. Other features include a coronagraph and a filter slide in the slow //9 beam which achieves the difficult and useful combination of narrow-band imaging with a wide field of view. The filter slide tilts to vary the center wavelength of narrow interference filters to accommodate different red shifts. The image quality is seeing-limited in the central 12' diameter, and degraded by about 0'.'8 in the central 18' diameter, and degraded by l"-2" at the edges of the field. The development of the optical system prescription is briefly discussed. The instrument is used to obtain continuum-corrected Ha and [S n] images of the edge-on galaxies NGC 4244 and NGC 5907. Interesting filamentary structure is evident. The distribution of ionized hydrogen gas in NGC 4244 and NGC 5907 is quantified. The data indicate those galaxies do not have an extended halo like that in NGC 891 and our Galaxy.

Lipoxin A4stable analogs inhibit leukocyte rolling and adherence in the rat mesenteric microvasculature: Role of P-selectin

“…Under such conditions, these eicosanoids transmit transcellular bioregulatory signals, as demonstrated in in vitro models of platelet-neutrophil interaction (28). In contrast to other lipid mediators, which are proinflammatory substances, lipoxins have anti-inflammatory properties that may serve a counterregulatory role limiting the effects of inflammatory signals in neutrophil recruitment and tissue destruction (1,11).…”

Gaseous Halos of Late-Type Spiral Galaxies

“…Not surprisingly, no indication has been found of any emission from its halo. For an image of the Ha/[S il] emission line ratio in NGC 4244 see Marcus (1997).…”

Increased leukotriene A4 hydrolase expression in the heart of angiotensin II‐induced hypertensive rat

“…Liberated arachidonic acid is then converted to LTA 4 through 5-hydroperoxy-6,8,11,14-eicosatetraenoic acid by the enzyme 5-lipoxygenase (5LO) [1] with 5LO activating protein. LTA 4 is further converted to LTB 4 by the action of LTA 4 hydrolase or is conjugated to form LTC 4 [2]. Although 5LO is thought to be exclusively present in leukocytes, exogenously produced LTA 4 can be metabolized to LTB 4 by the action of LTA 4 hydrolase [3,4], in non-leukocytes via transcellular LTA 4 metabolism.…”

“…LTA 4 is further converted to LTB 4 by the action of LTA 4 hydrolase or is conjugated to form LTC 4 [2]. Although 5LO is thought to be exclusively present in leukocytes, exogenously produced LTA 4 can be metabolized to LTB 4 by the action of LTA 4 hydrolase [3,4], in non-leukocytes via transcellular LTA 4 metabolism. Interestingly, exposure to substrate inactivates LTA 4 hydrolase as a consequence of the covalent binding of LTA 4 to the active site [5], implicating that LTA 4 -LTB 4 conversion is a self-limiting reaction unless LTA 4 hydrolase is synthesized de novo.…”

“…Of these, LTB 4 has the strongest chemotactic and chemoattracting activities on leukocytes and has been postulated to play an important role in a variety of pathological conditions including rheumatoid arthritis, psoriasis and in£ammatory bowel disease [6]. We have previously demonstrated that LTA 4 hydrolase is ubiquitously expressed in many tissues including heart, aorta, lung, intestinal tracts, liver [7] and kidney [8], as well as leukocytes. The wide distribution of LTA 4 hydrolase suggests a positive role of these non-leukocytic tissues in the generation of LTB 4 for the recruitment of leukocytes into the in£ammatory lesion.…”