The Combined Release and Radiation Effects Satellite (CRRES) program: A unique series of scientific experiments

The Defense Department and NASA have joined in a program to study the space environment which surrounds the earth and the effects of space radiation on modern satellite electronic systems. The Combined Release and Radiation Effects Satellite (CRRES) will carry an array of active experiments including chemical releases and a complement of sophisticated scientific instruments to accomplish these objectives. Other chemical release active experiments will be performed with sub-orbital rocket probes. The chemical releases will 'paint' the magnetic and electric fields of earthspace with clouds of glowing ions. Earthspace will be a laboratory, and the releases will be studied with an extensive network of ground-, aircraft-, and satellite-based diagnostic instruments. Some of the topics discussed include the following: the effects of earthspace; the need for active experiments; types of chemical releases; the CRRES program schedule; international support and coordinated studies; photographing chemical releases; information on locating chemical releases for observation by the amateur; and CRRES as a program

Spitzer 24 um Images of Planetary Nebulae

Spitzer MIPS 24 um images were obtained for 36 Galactic planetary nebulae (PNe) whose central stars are hot white dwarfs (WDs) or pre-WDs with effective temperatures of ~100,000 K or higher. Diffuse 24 um emission is detected in 28 of these PNe. The eight non-detections are angularly large PNe with very low H-alpha surface brightnesses. We find three types of correspondence between the 24 um emission and H-alpha line emission of these PNe: six show 24 um emission more extended than H-alpha emission, nine have a similar extent at 24 um and H-alpha, and 13 show diffuse 24 um emission near the center of the H-alpha shell. The sizes and surface brightnesses of these three groups of PNe and the non-detections suggest an evolutionary sequence, with the youngest ones being brightest and the most evolved ones undetected. The 24 um band emission from these PNe is attributed to [O IV] 25.9 um and [Ne V] 24.3 um line emission and dust continuum emission, but the relative contributions of these three components depend on the temperature of the central star and the distribution of gas and dust in the nebula.Comment: 24 pages, 8 figures, to appear in the Astronomical Journal, September issue. Relace previous file; two references are added and typos are correcte

The Torino Observatory Parallax Program: White Dwarf Candidates

We present parallax determinations for six white dwarf candidates in the Torino Observatory Parallax Program. The absolute parallaxes are found with precisions at the 2-3 milliarcsecond level. For WD 1126+185 we find a distance incompatible with being a white dwarf, implying an incorrect classification. For WD 2216+484 we find our distance is consistent with a simple DA white dwarf rather than a composite system as previously proposed in the literature. In general it is found that the published photometric distance is an overestimate of the distance found here.Comment: AA paper, 7 pages, 4 figure

Doom and Boom on a Resilient Reef: Climate Change, Algal Overgrowth and Coral Recovery

Background: Coral reefs around the world are experiencing large-scale degradation, largely due to global climate change, overfishing, diseases and eutrophication. Climate change models suggest increasing frequency and severity of warming-induced coral bleaching events, with consequent increases in coral mortality and algal overgrowth. Critically, the recovery of damaged reefs will depend on the reversibility of seaweed blooms, generally considered to depend on grazing of the seaweed, and replenishment of corals by larvae that successfully recruit to damaged reefs. These processes usually take years to decades to bring a reef back to coral dominance

C-C Chemokine Receptor 5 on Pulmonary Mesenchymal Cells Promotes Experimental Metastasis via the Induction of Erythroid Differentiation Regulator 1

C-C Chemokine receptor five knockout (Ccr5-/-) mice develop fewer experimental pulmonary metastases than wild type (WT) mice. This phenomenon was explored by applying gene-expression profiling to the lungs of mice with these metastases. Consequently, Erythroid Differentiation Regulator 1 (Erdr1) was identified as upregulated in the WT mice. Though commonly associated with bone marrow stroma, Erdr1 was differentially expressed in WT pulmonary mesenchymal cells (PMCs) and murine embryonic fibroblasts (MEFs). Moreover, the Ccr5 ligand Ccl4 increased its expression by 3.36 ± 0.14 fold. Ccr5 signaling was dependent on the Map2k but not the Pi3k pathway since treatment with U0126 inhibited upregulation of Erdr1 but treatment with LY294002 increased the expression by 3.44 ± 0.92 fold (p < 0.05). Erdr1's effect on B16-F10 melanoma metastasis was verified by the adoptive transfer of WT MEFs into Ccr5-/- mice. In this model, MEFs that had been transduced with Erdr1 shRNA lowered metastasis by 33% compared to control transduced MEFs. The relevance of ERDR1 on human disease was assessed by co-culturing chronic lymphocytic leukemia (CLL) cells with M2-10B4 stromal cells that had been transfected with shRNA or control plasmids. After 96 hours of co-culture, the cell counts were higher with control cell lines compared with Erdr1 knockdown lines (OR 1.88 ± 0.27, 2.52 ± 0.66 respectively). This increase was associated with a decrease in apoptotic cells (OR 0.69 ± 0.18, 0.58 ± 0.12 respectively)

Effects of pretreatment hypothermia during resuscitated porcine hemorrhagic shock

OBJECTIVES: Accidental hypothermia increases mortality and morbidity after hemorrhage, but controversial data are available on the effects of therapeutic hypothermia. Therefore, we tested the hypothesis whether moderate pretreatment hypothermia would beneficially influence organ dysfunction during long-term, porcine hemorrhage and resuscitation. DESIGN: Prospective, controlled, randomized study. SETTING: University animal research laboratory. SUBJECTS: Twenty domestic pigs of either gender. INTERVENTIONS: Using an extracorporeal heat exchanger, anesthetized and instrumented animals were maintained at 38 degrees C, 35 degrees C, or 32 degrees C core temperature and underwent 4 hours of hemorrhage (removal of 40% of the blood volume and subsequent blood removal/retransfusion to maintain mean arterial pressure at 30 mm Hg). Resuscitation comprised of hydroxyethyl starch and norepinephrine infusion titrated to maintain mean arterial pressure at preshock values. MEASUREMENTS AND MAIN RESULTS: Before, immediately at the end of, and 12 and 22 hours after hemorrhage, we measured systemic and regional hemodynamics (portal vein, hepatic and right kidney artery ultrasound flow probes) and oxygen transport, and nitric oxide and cytokine production. Hemostasis was assessed by rotation thromboelastometry. Postmortem biopsies were analyzed for histomorphology (hematoxylin and eosin staining) and markers of apoptosis (kidney Bcl-xL and caspase-3 expression). Hypothermia at 32 degrees C attenuated the shock-related lactic acidosis but caused metabolic acidosis, most likely resulting from reduced carbohydrate oxidation. Although hypothermia did not further aggravate shock-related coagulopathy, it caused a transitory attenuation of kidney and liver dysfunction, which was ultimately associated with reduced histological damage and more pronounced apoptosis. CONCLUSIONS: During long-term porcine hemorrhage and resuscitation, moderate pretreatment hypothermia was associated with a transitory attenuation of organ dysfunction and less severe histological tissue damage despite more pronounced metabolic acidosis. This effect is possibly due to a switch from necrotic to apoptotic cell death, ultimately resulting from reduced tissue energy deprivation during the shock phase

The stellar content of the Hamburg/ESO survey. II. A large, homogeneously-selected sample of high latitude carbon stars

We present a sample of 403 faint high latitude carbon (FHLC) stars selected from the digitized objective prism plates of the Hamburg/ESO Survey (HES). Because of the ~15 Angstroem spectral resolution and high signal-to-noise ratio of the HES prism spectra, our automated procedure based on the detection of C_2 and CN molecular bands permits high-confidence identification of carbon stars without the need for follow-up spectroscopy. From a set of 329 plates (87% of the survey), covering 6400 square degrees to a magnitude limit of V~16.5, we analyze the selection efficiency and effective surface area of the HES FHLC survey to date. The surface density of FHLC stars that we detect (0.072 +/- 0.005 square degrees) is 2-4 times higher than that of previous objective prism and CCD surveys at high galactic latitude, even though those surveys claimed a limiting magnitude up to 1.5 magnitudes fainter. This attests to the highest selection sensitivity yet achieved for these types of stars.Comment: 8 pages, 6 figures; A&A in pres

Synthesis of current knowledge of the biophysical impacts of dredging and disposal on the Great Barrier Reef: report of an Independent Panel of Experts

[Extract] This report provides an independent synthesis of the current knowledge of the effects of dredging and sediment disposal on the physico-chemical environment and the biological values of the Great Barrier Reef World Heritage Area (World Heritage Area), as assessed by an Expert Panel. Dredging and sediment disposal can change the physical and chemical environment and affect the biological values of the World Heritage Area. Many of these effects will be context dependent and will differ between locations, types and extent of dredging and sediment disposal activities. The Expert Panel's evaluation identified the following key direct and indirect effects

On the nature of the FBS blue stellar objects and the completeness of the Bright Quasar Survey. II

In Paper I (Mickaelian et al. 1999), we compared the surface density of QSOs in the Bright Quasar Survey (BQS) and in the First Byurakan Survey (FBS) and concluded that the completeness of the BQS is of the order of 70% rather than 30-50% as suggested by several authors. A number of new observations recently became available, allowing a re-evaluation of this completeness. We now obtain a surface density of QSOs brighter than B = 16.16 in a subarea of the FBS covering ~2250 deg^2, equal to 0.012 deg^-2 (26 QSOs), implying a completeness of 53+/-10%.Comment: LaTeX 2e, 11 pages, 3 tables and 3 figures (included in text). To appear in Astrophysics. Uses a modified aaspp4.sty (my_aaspp4.sty), included in packag