Apollo 16 exploration of descartes: a geologic summary

The Cayley Plains at the Apollo 16 landing site consist of crudely stratified breccias to a depth of at least 200 meters, overlain by a regolith 10 to 15 meters thick. Samples, photographs, and observations by the astronauts indicate that most of the rocks are impact breccias derived from an anorthositegabbro complex. The least brecciated members of the suite include coarse-grained anorthosite and finer-grained, more mafic rocks, some with igneous and some with metamorphic textures. Much of the traverse area is covered by ejecta from North Ray and South Ray craters, but the abundance of rock fragments increases to the south toward the younger South Ray crater. The Descartes highlands, a distinct morphologic entity, differ from the adjacent Cayley formation more in physiographic expression than in lithologic character.     

Large wind speeds: Modeling and outlier detection

This article addresses the problem of modeling extreme wind speeds with the aim of developing procedures that can be used to reliably identify outliers. There are several approaches to fitting extremes, including using maxima over a fixed time period or taking all observations over a threshold. Using two sets of oceanic wind data from buoys, we use robust estimation methods to estimate the parameters of the asymptotic distribution for extremes over fixed time periods and peaks over threshold. For both cases we also use a gh distribution which focuses on modeling the quantiles and propose a robust method for fitting the data to the gh distribution. Weights from the robust fits are used to identify outliers with P values being computed by resampling. We also evaluate the fits of the data to the model distributions according to several criteria concluding that the gh distribution is at least as effective in fitting the tail behavior as the more classical generalized extreme value distribution and the generalized Pareto distribution.     

Linking vegetation patterns to environmental gradients and human impacts in a mediterranean-type island ecosystem

Vegetation patterns at the landscape scale are shaped by myriad processes and historical events, and understanding the relative importance of these processes aids in predicting current and future plant distributions. To quantify the influence of different environmental and anthropogenic patterns on observed vegetation patterns, we used simultaneous autoregressive modeling to analyze data collected by the Carnegie Airborne Observatory over Santa Cruz Island (SCI; California, USA). SCI is a large continental island, and its limited suite of species and well documented land use history allowed us to consider many potential determinants of vegetation patterns, such as topography, substrate, and historical grazing intensity. As a metric of vegetation heterogeneity, we used the normalized difference vegetation index (NDVI) stratified into three vegetation height classes using LiDAR (short, medium, and tall). In the SAR models topography and substrate type were important controls, together explaining 8–15 % of the total variation in NDVI, but historical grazing and spatial autocorrelation were also key components of the models, together explaining 17–21 % of the variation in NDVI. Optimal spatial autocorrelation distances in the short and medium height vegetation models (600–700 m) were similar to the home range sizes of two crucial seed dispersers on the island– the island fox (Urocyon littoralis santacruzae) and the island scrub-jay (Aphelocoma insularis)—suggesting that these animals may be important drivers of the island’s vegetation patterns. This study highlights the importance of dynamic processes like dispersal limitation and disturbance history in determining present-day vegetation patterns.     

The immune modifying effects of amino acids on gut-associated lymphoid tissue

The intestine and the gut-associated lymphoid tissue (GALT) are essential components of whole body immune defense, protecting the body from foreign antigens and pathogens, while allowing tolerance to commensal bacteria and dietary antigens. The requirement for protein to support the immune system is well established. Less is known regarding the immune modifying properties of individual amino acids, particularly on the GALT. Both oral and parenteral feeding studies have established convincing evidence that not only the total protein intake, but the availability of specific dietary amino acids (in particular glutamine, glutamate, and arginine, and perhaps methionine, cysteine and threonine) are essential to optimizing the immune functions of the intestine and the proximal resident immune cells. These amino acids each have unique properties that include, maintaining the integrity, growth and function of the intestine, as well as normalizing inflammatory cytokine secretion and improving T-lymphocyte numbers, specific T cell functions, and the secretion of IgA by lamina propria cells. Our understanding of this area has come from studies that have supplemented single amino acids to a mixed protein diet and measuring the effect on specific immune parameters. Future studies should be designed using amino acid mixtures that target a number of specific functions of GALT in order to optimize immune function in domestic animals and humans during critical periods of development and various disease states.     

The ‘Turbulometer’—An Apparatus for Measuring Relative Exposure to Wave Action on Shores

The growth and development of the stomach, gastric epithelia and associated microflora of M. albicaudatus have been quantified and a chronology of morphological, histological and ultrastructural events documented. In neonates, a monogastric stomach was present with distinct separation of glandular (antral) and cornified (fornical) regions. Development of the fornix ventricularis and ‘grenzfalte’ characterized the transitional period and gave rise to the bilocular condition. An early autochthonous microflora of facultative cocci and cocco-bacilli became established. In the infantile phase, fornical papillae developed and provided microhabitats for colonization by symbiotic anaerobic bacilli. Cocci and cocco-bacilli remained attached to (or successive populations colonized) the folded fornical epithelium and pregastric pouch. All common bacteria , were attached to the gastric epithelium by a capsular (slime) layer in palisade formation. The synchrony of events in gastric development (appearance of papillae, ingestion of solid food and the colonization of papillae by bacilli), the numerical abundance of papillae bacilli, and the absence of epithelial damage, suggest that the bacilli are autochthonous, symbiotic and aid the digestive processes of M. albicaudatus.     

A Study of the Feeding Habits of the Hippopotamus (Hippopotamus Amphibius Linn.) in the Queen Elizabeth National Park,Uganda, With Some Management Implications

This paper reports on the effects of varying the concentration of sea water dosed at a rate of 10% of body mass on the handling of fluid and solutes by jackass penguins (Spheniscus demersus). The salt gland only secreted when the seawater dosed was hypertonic to the plasma and caused a rise in plasma osmotic concentration of at least 7,5%. The gland reacts to different marginal osmotic loads (equivalent to 40 and 50% seawater) by varying the flow rate and total concentration to match the degree of osmotic stress. High osmotic loads resulted in maximum flow rates and concentration from the onset of secretion. The relative composition of the ions was not affected by flow rate. Cloacal excretion decreased with a decreasing osmotic load, especially at those seawater concentrations that failed to stimulate the salt gland. This cloacal control is interpreted as a graded mechanism to dispose of osmotic loads. The cloacal system is stimulated to excrete by the same stimuli as the salt gland. Apparent selective Na* absorption by the cloaca was also noted.     

Numerical Methods in Marine Ecology 2. Gradient Analysis of Rocky Shore Samples from False Bay

The ability of small mammals to select Protea neriifolia seeds containing embryos (full seeds) was examined. Full and empty seeds were glued to wooden boards and placed at three sites in young fynbos. Small mammals were able to select and remove significantly more full seeds than expected. Seed removal rates varied between the study sites but this was not related to the density of small mammals trapped at those sites. Selective feeding greatly increases the feeding efficiency of small mammals because 90% or more of the seed dispersed after fires may be empty.     

Respiration and ecological energetics of the sea urchin Parechinus angulosus

Respiration rates of Parechinus angulosus collected from intertidal pools at Dalebrook, False Bay, were measured in the laboratory at 16 #x00B0;C using the sealed-vessel method. No respiratory rhythms were detected over three 26-hour runs each Involving eight animals of different sizes. Respiration rates, expressed for an animal of standard diameter, increased proportionally to gonad Index. Annual production of the intertidal P. angulosus population was calculated from the respiration and population data using the P/R regression of Miller, Mann and Scarratt (1971), and was estimated to be about 1200 kJ m^-2 year^-1.     

The interactions between piperonyl butoxide and E4, a resistance‐associated esterase from the peach‐potato aphid,Myzus persicae Sulzer (Hemiptera: Aphididae)

BACKGROUND: It has been reported previously that piperonyl butoxide (PBO) can inhibit both P450 and esterase activity. Although the method by which PBO combines with cytochrome P450 has been identified, the way in which it acts as an esterase inhibitor has not been established. This paper characterises the interactions between PBO and the resistance‐associated esterase in Myzus persicae, E4. RESULTS: After incubation with PBO/analogues, hydrolysis of 1‐naphthyl acetate by E4 is increased, but sequestration of azamethiphos is reduced. Rudimentary in silico modelling suggests PBO docks at the lip of the aromatic gorge. CONCLUSIONS: PBO binds with E4 to accelerate small substrates to the active‐site triad, while acting as a blockade to larger, insecticidal molecules. Structure–activity studies with analogues of PBO also reveal the essential chemical moieties present in the molecule. © 2012 Society of Chemical Industry