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Measurements in the infrared wavelength domain allow direct assessment of the physical state and energy balance of cool matter in space, enabling the detailed study of the processes that govern the formation and evolution of stars and planetary systems in galaxies over cosmic time. Previous infrared missions revealed a great deal about the obscured Universe, but were hampered by limited sensitivity.
SPICA takes the next step in infrared observational capability by combining a large 2.5-meter diameter telescope, cooled to below 8 K, with instruments employing ultra-sensitive detectors. A combination of passive cooling and mechanical coolers will be used to cool both the telescope and the instruments. With mechanical coolers the mission lifetime is not limited by the supply of cryogen. With the combination of low telescope background and instruments with state-of-the-art detectors SPICA provides a huge advance on the capabilities of previous missions.
SPICA instruments offer spectral resolving power ranging from R ~50 through 11 000 in the 17–230 μm domain and R ~28.000 spectroscopy between 12 and 18 μm. SPICA will provide efficient 30–37 μm broad band mapping, and small field spectroscopic and polarimetric imaging at 100, 200 and 350 μm. SPICA will provide infrared spectroscopy with an unprecedented sensitivity of ~5 × 10−20 W m−2 (5σ/1 h)—over two orders of magnitude improvement over what earlier missions. This exceptional performance leap, will open entirely new domains in infrared astronomy; galaxy evolution and metal production over cosmic time, dust formation and evolution from very early epochs onwards, the formation history of planetary systems.
Near IR total eclipse measurements have provided clear evidence during both 2nd and 3rd contacts for a limb extension of about 125 km for wavelengths in the range containing the CO fundamental vibration-rotation bands between 4.3 and 5.5 μm, when compared to the limb at nearby shorter wavelengths. This is interpreted as a “flash” spectrum in the CO lines, with the above extension representing the outer level of the CO emission layer. This height can be compared to the τCO = 1.0 level incorporated into recent representative atmospheric models (Ayres and Wiedemann, 1989) which is 90 km above the visible limb for a semi-empirical “hot chromosphere” model (Avrett, 1985) and 220 km for a “cool” radiative equilibrium model based upon work by Anderson (1989).
A two-beam Martin-Puplett polarizing interferometer has been used in the rapid-scan mode on the 15 meter JCMT in conjunction with the facility detector, UKT14, to survey the solar sub-millimeter and millimeter spectrum in the four wavebands at 7-11, 11-15, 21-24 and 27-30 cm–1 to a spectral resolution of 0.01 cm–1 and at spatial resolutions of 19″, 16″, 7″ and 6″, respectively. Overall atmospheric transmission through these windows has been evaluated by comparison with synthetic spectra generated with FASCOD/HITRAN. A search has been made for contributions to these spectra from high-n transitions of H and heavier elements by several methods, including the comparison of solar with lunar and limb with disk center spectra.
Atmospheric gas samples (0.1m3) were collected at ground level during January/February 1984 in Las Vegas, Nevada for 14C/13C accelerator mass spectrometry and total abundance measurements of CO and CH4. During winter months in this locale, CO concentrations can occur at 10 to 100 times background, occasionally exceeding the National Ambient Air Quality Standard (NAAQS). Methane concentrations show a slight enhancement (∼24%) above the background (non-urban troposphere) level. A comparison of CO and CH4 concentrations shows a good linear correlation which may indicate a common source. Preliminary 14C/13C results of the two species suggest that fossil emissions are the predominant source of excess CO and CH4 in the samples taken. Estimates of anthropogenic CO and CH4 are important for source apportionment of combustion emissions. In addition, this information is valuable for understanding the global CO and CH4 cycles and, therefore, human impact on climate and the stratospheric ozone layer.
We present optical and IR observations of the dwarf nova OY Car during the May 1985 superoutburst. From them we find that the superhump has a temperature of ~8000K and an area of order half the size of the red dwarf or accretion disk. We also compare the behaviour during two simultaneous optical/IR observations. Whilst the light curves in the two pass bands are similar during one observation, in the other observation they show marked differences that may be due to a cool region in the outer disk.
IP Peg is a U Gem-type dwarf nova with a very high orbital inclination such that the secondary star eclipses the white dwarf primary, accretion disc and hot spot in each orbit. An observing project was set up by ‘The Astronomer’ (TA) magazine and the British Astronomical Association Variable Star Section to make visual and CCD eclipse observations of IP Peg during outbursts in the 1994/95 season.
We present ultraviolet and X-ray observations of the eclipsing SU UMa dwarf nova OY Car early in the decline from a superoutburst. From the UV emission line spectrum and lack of X-ray eclipse, we deduce the presence of an extended coronal region.
The use of underground geological repositories, such as in radioactive waste disposal (RWD) and in carbon capture (widely known as Carbon Capture and Storage; CCS), constitutes a key environmental priority for the 21st century. Based on the identification of key scientific questions relating to the geophysics, geochemistry and geobiology of geodisposal of wastes, this paper describes the possibility of technology transfer from high-technology areas of the space exploration sector, including astrobiology, planetary sciences, astronomy, and also particle and nuclear physics, into geodisposal. Synergies exist between high technology used in the space sector and in the characterization of underground environments such as repositories, because of common objectives with respect to instrument miniaturization, low power requirements, durability under extreme conditions (in temperature and mechanical loads) and operation in remote or otherwise difficult to access environments.
The Magellanic System represents one of the best places to study the formation and evolution of galaxies. Photometric surveys of various depths, areas and wavelengths have had a significant impact on our understanding of the system; however, a complete picture is still lacking. VMC (the VISTA near-infrared YJKs survey of the Magellanic System) will provide new data to derive the spatially resolved star formation history and to construct a three-dimensional map of the system. These data combined with those from other ongoing and planned surveys will give us an absolutely unique view of the system opening up the doors to truly new science!
Herbicides are the primary method used to control exotic, invasive plants. This study evaluated restoration efforts applied to grasslands dominated by an invasive plant, sulfur cinquefoil, 6 yr after treatments. Of the five herbicides we evaluated, picloram continued to provide the best control of sulfur cinquefoil over 6 yr. We found the timing of picloram applications to be important to the native forb community. Plots with picloram applied in the fall had greater native forb cover. However, without the addition of native perennial grass seeds, the sites became dominated by exotic grasses. Seeding resulted in a 20% decrease in exotic grass cover. Successful establishment of native perennial grasses was not apparent until 6 yr after seeding. Our study found integrating herbicide application and the addition of native grass seed to be an effective grassland restoration strategy, at least in the case where livestock are excluded.
A new experimental technique for the characterisation of the thermal-morphological properties of materials has been developed at Daresbury. Many thermal events, for example melting endotherms, are signals of changes in morphology covering size scales from the atomic to the microscopic, that is Å to μm. There are obvious advantages in collecting both the wide angle (1-20Å) and small angle (20-1000Å) patterns simultaneously to unambiguously characterise such thermal events. The new apparatus comprises a Linkam hot-stage capable of controlled heating and cooling mounted in a combined SAXS/WAXS camera. The camera is equipped with a multiwire quadrant detector (SAXS) located 3.5 m from the sample position and a curved knifeedge detector (WAXS) that covers 120° of arc at a radius of 0.4 m. SAXSIWAXS is possible with a time resolution of 0.1 seconds and heating/cooling rates up to 120 °C min-1.
Tamarisk species are shrubs or small trees considered by some to be among the most aggressively invasive and potentially detrimental exotic plants in the United States. Although extensively studied in the southern and interior west, northwestern (Oregon, Washington, and Idaho) distribution and habitat information for tamarisk is either limited or lacking. We obtained distribution data for the northwest, developed a habitat suitability map, and projected changes in habitat due to climate change in a smaller case study area using downscaled climate data. Results show extensive populations of tamarisk east of the Cascade Mountains. Despite the perceived novelty of tamarisk in the region, naturalized populations were present by the 1920s. Major population centers are limited to the warmest and driest environments in the central Snake River Plain, Columbia Plateau, and Northern Basin and Range. Habitat suitability model results indicate that 21% of the region supports suitable tamarisk habitat. Less than 1% of these areas are occupied by tamarisk; the remainder is highly vulnerable to invasion. Although considerable uncertainty exists regarding future climate change, we project a 2- to 10-fold increase in highly suitable tamarisk habitat by the end of the century. Our habitat suitability maps can be used in “what if” exercises as part of planning, detection, restoration, management, and eradication purposes.
In the Cambridge area, 143 patients infected with Corynebacterium haemolyticum were found during the period May 1967 to December 1974. The pharynx was the commonest site of infection and 100 of the 137 pharyngeal infections were in patients aged between 15 and 25 years. Such patients usually had a sore throat; about half of them also had a maculopapular rash. The organism and the clinical features which we have come to regard as typical of this infection are briefly described.
SPIRE, the Spectral and Photometric Imaging Receiver, is Herschel's submillimetre camera and spectrometer. It comprises a three-band imaging photometer operating at 250, 350 and 500 μm, and an imaging Fourier Transform Spectrometer (FTS) covering 194–672 μm. The design of SPIRE is described, and the expected scientific performance is summarised, based on modelling and flight instrument test results.
Sulfur cinquefoil is an exotic, perennial forb that invades a wide range of ecosystems in western North America. It forms dense populations and often threatens native plant species and communities. In this study, we address the following questions: (1) what herbicides, rates, and application times are most effective at reducing sulfur cinquefoil abundance while having the least impact on native plants; and (2) does postherbicide seeding with native grass species increase native plant abundance? In 2002, we experimentally examined the effects of five herbicides (dicamba + 2,4-D; metsulfuron-methyl; triclopyr; glyphosate; and picloram) at two rates of application (low and high), three application times (early summer, fall, and a combined early summer–fall treatment), and two postherbicide seed addition treatments (seeded or not seeded) on sulfur cinquefoil abundance, plant community composition, and species richness. Experimental plots were monitored through 2005. Picloram was the most effective herbicide at reducing sulfur cinquefoil density, the proportion of remaining adult plants, and seed production. The effects of picloram continued to be evident after 3 yr, with 80% reduction of sulfur cinquefoil in 2005. In addition, seeding of native grass seeds alone (no herbicide application) reduced the proportion of sulfur cinquefoil plants that were reproductively active. Despite reductions in sulfur cinquefoil abundance, all treatments remained dominated by exotic species because treated areas transitioned from exotic forb- to exotic grass-dominated communities. However, a one-time herbicide application controlled sulfur cinquefoil for at least 3 yr, and therefore might provide a foundation to begin ecological restoration. Herbicide applications alone likely are to be insufficient for long-term sulfur cinquefoil control without further modification of sites through native grass or forb seeding. Integrating herbicides with native plant seeding to promote the development of plant communities that are resistant to sulfur cinquefoil invasion is a promising management approach to ecological restoration.
Free radicals and reactive species produced in vivo can trigger cell damage and DNA modifications resulting in carcinogenesis. Dietary antioxidants trap these species limiting their damage. The present study evaluated the role of vitamins C and E in the prevention of potentially premalignant modifications to DNA in the human stomach by supplementing patients who, because of hypochlorhydria and possible depletion of gastric antioxidants, could be at increased risk of gastric cancer. Patients undergoing surveillance for Barrett's oesophagus (n 100), on long-term proton pump inhibitors were randomized into two groups: vitamin C (500 mg twice/d) and vitamin E (100 mg twice/d) for 12 weeks (the supplemented group) or placebo. Those attending for subsequent endoscopy had gastric juice, plasma and mucosal measurements of vitamin levels and markers of DNA damage. Seventy-two patients completed the study. Plasma ascorbic acid, total vitamin C and vitamin E were elevated in the supplemented group consistent with compliance. Gastric juice ascorbic acid and total vitamin C levels were raised significantly in the supplemented group (P=0·01) but supplementation had no effect on the mucosal level of this vitamin. However, gastric juice ascorbic acid and total vitamin C were within normal ranges in the unsupplemented group. Mucosal malondialdehyde, chemiluminescence and DNA damage levels in the comet assay were unaffected by vitamin supplementation. In conclusion, supplementation does not affect DNA damage in this group of patients. This is probably because long-term inhibition of the gastric proton pump alone does not affect gastric juice ascorbate and therefore does not increase the theoretical risk of gastric cancer because of antioxidant depletion.
Three studies are reported. In study 1, vanadium concentration was estimated by neutron activation analysis in hair, whole blood, serum and urine from 13 patients suffering from depressive psychosis and then when on recovery- Vanadium concentration of hair, whole blood and serum decreased significantly with recovery, but there was no significant change in 24-h urinary excretion or in renal clearance of vanadium. In study 2, vanadium concentration was estimated by neutron activation analysis in serum and urine of 31 patients with depressive psychosis and of 27 normal controls. Mean renal clearance of vanadium was significantly lower and mean serum vanadium concentration significantly higher in depressed patients than in controls. Mean 24-h excretion of vanadium did not differ between the two groups. Vanadium excretion did not correlate with urine volume, with serum concentration or with age. In study 3, erythrocyte Na-K ATPase activity and serum vanadium concentrations were estimated in 58 patients. There was a strong negative correlation between the two, supporting the suggestion that changes in tissue vanadium concentration may explain the changes in sodium transport which occur in depressive psychosis.
A double-blind cross-over trial of depot flupenthixol in recurrent manic depressive psychosis was carried out. Ail patients continued on lithium. Eleven patients completed the two-year trial. Flupenthixol appeared to have no prophylactic effect.
Indalpine 150 mg per day and mianserin 60 mg per day were compared in a double-blind study of 65 depressed out-patients: 52 patients completed the 4-week trial. At the end of four weeks there was no significant difference in antidepressant effect between the two drugs; but in the first two weeks, improvement in the mianserin-treated group was significantly greater than that in the indalpine group. The mianserin-treated group reported more side-effects of sedation (eg. drowsiness, clumsiness, heaviness of limbs etc.) and one patient on indalpine developed a mild leucopenia.