Spectroscopic determination of the phase composition and temperature of nitrogen ice on triton

Laboratory spectra of the first overtone band (2.1480 micrometers, 4655.4 reciprocal centimeters) of solid nitrogen show additional structure at 2.1618 micrometers (4625.8 reciprocal centimeters) over a limited temperature range. The spectrum of Neptune's satellite Triton shows the nitrogen overtone band as well as the temperature-sensitive component. The temperature dependence of this band may be used in conjunction with ground-based observations of Triton as an independent means of determining the temperature of surface deposits of nitrogen ice. The surface temperature of Triton is found to be 38.0(+2.0)(-1.0) K, in agreement with previous temperature estimates and measurements. There is no spectral evidenceforthe presence of alpha-nitrogen on Triton's surface, indicating thatthere is less than 10 percent carbon monoxide in solid solution with the nitrogen on the surface.     

Encounter with saturn: voyager 1 imaging science results

As Voyager 1 flew through the Saturn system it returned photographs revealing many new and surprising characteristics of this complicated community of bodies. Saturn's atmosphere has numerous, low-contrast, discrete cloud features and a pattern of circulation significantly different from that of Jupiter. Titan is shrouded in a haze layer that varies in thickness and appearance. Among the icy satellites there is considerable variety in density, albedo, and surface morphology and substantial evidence for endogenic surface modification. Trends in density and crater characteristics are quite unlike those of the Galilean satellites. Small inner satellites, three of which were discovered in Voyager images, interact gravitationally with one another and with the ring particles in ways not observed elsewhere in the solar system. Saturn's broad A, B, and C rings contain hundreds of "ringlets," and in the densest portion of the B ring there are numerous nonaxisymmetric features. The narrow F ring has three components which, in at least one instance, are kinked and crisscrossed. Two rings are observed beyond the F ring, and material is seen between the C ring and the planet.     

Estimating the mass of asteroid 253 mathilde from tracking data during the NEAR flyby

The terminal navigation of the Near Earth Asteroid Rendezvous (NEAR) spacecraft during its close flyby of asteroid 253 Mathilde involved coordinated efforts to determine the heliocentric orbits of the spacecraft and Mathilde and then to determine the relative trajectory of the spacecraft with respect to Mathilde. The gravitational perturbation of Mathilde on the passing spacecraft was apparent in the spacecraft tracking data. As a result of the accurate targeting achieved, these data could be used to determine Mathilde's mass as 1.033 (+/- 0.044) x 10(20) grams. Coupled with a volume estimate provided by the NEAR imaging team, this mass suggests a low bulk density for Mathilde of 1.3 grams per cubic centimeter.     

Volatile organic compounds in the roots and rhizosphere of Pinus spp.

Plant roots normally release a complex mixture of chemicals which have important effects in the rhizosphere. Among these different root-emitted compounds, volatile isoprenoids have received very little attention, yet they may play important and diverse roles in the rhizosphere, contributing to the regulation of microbial activity and nutrient availability. It is therefore important to estimate their abundance in the rhizosphere, but so far, there is no reliable sampling method that can be used to measure realistic rates of root emissions from plants growing in field conditions, or even in pots. Here, we measured root content of volatile isoprenoids (specifically monoterpenes) for Pinus pinea, and explored the feasibility of using a dynamic bag enclosure method to measure emissions from roots of intact pot-grown plants with different degrees of root cleaning. We also investigated a passive diffusion method for exploring monoterpenes in soil at incremental distances from mature Pinus sylvestris trees growing in field conditions. Total monoterpene content of P. pinea roots was 415±50 μg g⁻¹ fresh wt in an initial screening study, and between 688±103 and 1144±208 μg g⁻¹ dry wt in subsequent investigations. Emissions from shaken-clean roots of intact plants and roots of intact plants washed to remove remaining soil after shaken-clean experiments were 119±14 and 26±5 μg g⁻¹ dry wt h⁻¹, respectively. Emissions from intact roots in soil-balls were an order of magnitude lower than from shaken-clean roots, and probably reflected the amount of emitted compounds taken up by physical, chemical or biological processes in the soil matrix surrounding the roots. Although monoterpene content was not significantly different in droughted roots, emission rates from droughted roots were generally significantly lower than from well-watered roots. Finally, passive sampling of monoterpenes in the soil at different distances from mature P. sylvestris trees in field conditions showed significantly decreasing sampling rates with increasing distance from the trunk. We conclude that it is feasible to measure volatile isoprenoid emissions from roots but the method of root preparation affects magnitude of measured emissions and therefore must be decided according to the application. We also conclude that the rhizosphere of Pinus species is a strong and previously un-characterized source of volatile isoprenoid emissions and these are likely to impact significantly on rhizosphere function.     

An investigation into the effects of storage on the diagnosis of crystalluria in cats

Urinalysis was performed on 41 cats with no history of urinary tract disease. Samples were divided into aliquots, stored under differing condition and then examined for the presence of crystalluria. Crystalluria was detected in at least one stored sample in 92% of cats fed a mixed wet/dry food diet compared to 24% in the fresh sample. Crystalluria was not detected in any sample or aliquot from cats fed all wet food diets.     

Concurrent gastro-oesophageal intussusception,trichobezoar and hiatal hernia in a cat

CASE HISTORY: An adult male Birman cat was evaluated for recurrent, intermittent vomiting or regurgitation, occasionally associated with abdominal discomfort.

CLINICAL FINDINGS AND DIAGNOSIS: Radiographs, including an oesophogram, indicated an oesophageal obstruction. Prior to treatment, the cat's condition deteriorated and it was euthanised at the owner's request. Post-mortem examination revealed a gastro-oesophageal intussusception, a trichobezoar impacted into the intussusceptum, and a dilated oesophageal hiatus consistent with a chronic hiatal hernia.

CLINICAL RELEVANCE: Gastro-oesophageal intussusception is a rare condition in cats. Its aetiology in relation to a pre-existing hiatal hernia and a trichobezoar is discussed.