Fundamental issues in the geology and geophysics of venus

A number of important and currently unresolved issues in the global geology and geophysics of Venus will be addressable with the radar imaging, altimetry, and gravity measurements now forthcoming from the Magellan mission. Among these are the global volcanic flux and the rate of formation of new crust; the global heat flux and its regional variations; the relative importance of localized hot spots and linear centers of crustal spreading to crustal formation and tectonics; and the planform of mantle convection on Venus and the nature of the interactions among interior convective flow, near-surface deformation and magmatism.     

Lunar impact basins and crustal heterogeneity: new Western limb and far side data from galileo

Multispectral images of the lunar western limb and far side obtained from Galileo reveal the compositional nature of several prominent lunar features and provide new information on lunar evolution. The data reveal that the ejecta from the Orientale impact basin (900 kilometers in diameter) lying outside the Cordillera Mountains was excavated from the crust, not the mantle, and covers pre-Orientale terrain that consisted of both highland materials and relatively large expanses of ancient mare basalts. The inside of the far side South Pole-Aitken basin (>2000 kilometers in diameter) has low albedo, red color, and a relatively high abundance of iron- and magnesium-rich materials. These features suggest that the impact may have penetrated into the deep crust or lunar mantle or that the basin contains ancient mare basalts that were later covered by highlands ejecta.     

Galileo multispectral imaging of the north polar and eastern limb regions of the moon

Multispectral images obtained during the Galileo probe's second encounter with the moon reveal the compositional nature of the north polar regions and the northeastern limb. Mare deposits in these regions are found to be primarily low to medium titanium lavas and, as on the western limb, show only slight spectral heterogeneity. The northern light plains are found to have the spectral characteristics of highlands materials, show little evidence for the presence of cryptomaria, and were most likely emplaced by impact processes regardless of their age.     

Technique and Preliminary Observations on Growth of the Roots of Glasshouse Tomatoes in Relation to That of the Tops

The use of glass-sided boxes and trenches for observing the growth of the roots of glasshouse tomatoes has been investigated. Marked seasonal trends have been found with two varieties in two years. There was a rise to a peak followed by a rapid fall in total root length, due to death and disappearance of the roots, with a subsequent recovery. This trend occurred in all horizons of soil.

Growth of the stem and leaves was relatively steady from planting-out (March) until mid-May, when there was a slight decrease with subsequent recovery until the main stem and laterals were “stopped” in July.

The number of flowers per truss was high in the bottom five or six trusses, in which fruit set was high, fell in the median trusses which had low set, and rose in the uppermost trusses accompanied by increased set. The resulting production of fruit weight was high in the bottom trusses and low in the top.

The peak of root length development coincided with the swelling of the fruit in the bottom trusses; a trough occurred when the number of flowers per truss and the number set were low, and root length recovered when the first trusses were picked.     

Farrier services at veterinary teaching hospitals in the USA

Horse health is best served when farriers and veterinarians collaborate in the care of their patients. Veterinary Teaching Hospitals (VTHs) provide an environment that can nurture that collaboration. While VTH veterinary services are well known, VTH farrier activities are undocumented. To characterise farrier services at VTHs in the USA, 27 VTH Diplomates of the American College of Veterinary Surgeons and/or VTH farriers completed a multiple choice questionnaire characterising VTH farrier details, training, certification, remuneration method, and clinical, teaching and research responsibilities; and farrier service prevalence, facilities and financial viability. Questionnaire response rate was 81%. Eighteen of 22 (82%) responding VTHs had in‐house farrier services. Twenty‐one of 22 (95%) VTH farriers were male. Farriers' ages ranged from <30 years (n = 1, 5%) to >50 years (n = 7, 32%). At 11 (61%) VTHs the farriers were paid by the client and at 7 (39%) by the VTH. Five farriers (23%) received a VTH salary. Eighteen of 22 (82%) farriers had a professional certification. At 5 (28%) VTHs the farrier service made a profit and operational costs were met at 13 (72%). Fifteen (83%) farrier services provided professional education in clinical settings and 13 (72%) in lecture settings. Nine (41%) VTH farriers participated in research activities. In the USA, VTH farrier services vary considerably in both nature and extent. The farriers' potential contributions to VTH operations are often recognised but not consistently exploited. VTH farriers are a valuable resource who can contribute effectively toward VTH patient care, veterinary education and research.     

Susceptibility of Cry1Ab-susceptible and -resistant sugarcane borer to transgenic corn plants containing single or pyramided Bacillus thuringiensis genes

Multiple independent trials were conducted to evaluate the performance of Cry1Ab-susceptible (Cry1Ab-SS), -heterozygous (Cry1Ab-RS), and -resistant (Cry1Ab-RR) genotypes of the sugarcane borer, Diatraea saccharalis (F.), on eight commercial hybrids and six experimental corn lines. The commercial varieties included two non-Bt and six Bt corn hybrids that expressed a single Bt protein (either Cry1Ab or Cry1F) targeting above-ground lepidopteran pests. The six experimental lines consisted of two non-Bt and four Bt corn lines, two expressing just the Cry1Ab protein and two containing the pyramided-genes Cry1A.105 and Cry2Ab2 (event MON 89034). Larval mortality on non-Bt corn leaf tissue ranged from 6 to 45% after 12 d across insect genotypes. The 12 d mortality of Cry1Ab-SS on leaf tissue of commercial Cry1Ab or Cry1F corn was 96-100%, whereas it was 80-96% for Cry1Ab-RS and 68-78% for Cry1Ab-RR. On intact plants, 39-64% of larvae survived on non-Bt corn plants after 21-25 d. Larval survivorship on intact plants of commercial Cry1Ab or Cry1F corn was 0-8.1% for Cry1Ab-SS, 1.3-34% for Cry1Ab-RS, and 19-51% for Cry1Ab-RR. Larvae of Cry1Ab-RR and -RS also caused significant plant injury to most of the commercial Bt corn hybrids, especially to the Cry1Ab corn. Cry1Ab resistance in D. saccharalis was incompletely dominant on commercial Bt corn hybrids. However, both experimental lines with pyramided genes of Cry1A.105 and Cry2Ab2 provided complete control of all three insect genotypes in both leaf tissue and intact plant tests. Results of this study suggest that MON 89034 should offer a means for Bt resistance management in D. saccharalis.     

Effects of level of energy intake and energy demand on growth hormone, insulin, and metabolites in Targhee and Suffolk ewes.

Yearling ewes (n = 32) were used in a 2x2x2 factorial experiment to determine effects of breed (Targhee vs. Suffolk), energy intake (1x vs. 3x NEm requirements, and physiological status (nonpregnant, nonlactating vs. lactating) on serum GH, insulin, NEFA, glucose, and blood urea nitrogen (BUN) concentrations. Blood collections were made in two periods that began 21 and 32 d after ewes lambed. Lactating ewes had more GH peaks (P<.10), higher (P<.01) mean GH concentration, and greater (P<.01) area under the GH curve (AUC) than nonlactating ewes. The AUC was greater (P<.01) in ewes fed 1x NEm than in ewes fed 3x NEm. Energy intake had no effect on serum GH before feeding (P>.23) when evaluated within physiological statuses. After feeding, GH concentrations were greater (P<.10) for ewes fed 1x NEm than for those fed 3x NEm. Insulin and glucose did not differ (P>.23) between energy intake levels. Insulin and glucose were greater (P<.001) in nonlactating than in lactating ewes when evaluated within breed. Lactating and Targhee ewes fed 1x NEm had greater (P<.001) NEFA concentration than nonlactating and Targhee ewes fed 3x NEm, respectively. Ewes fed 3x NEm and Targhee ewes had greater (P<.005) BUN concentrations than ewes fed 1x NEm and Suffolk ewes, respectively. Physiological status seems to play a more important role in the regulation of GH than does energy intake. Higher BUN concentrations in Targhee than in Suffolk ewes demonstrates one metabolic event that distinguishes a breed's adaptation to the environment in which it originated.