Venera 13 and venera 14: sedimentary rocks on venus?

Venera 13 and Venera 14 transmitted almost complete panoramic views of their landing sites. Analyses of the photographs show the presence of rock formations undergoing geomorphic degradation. The formations display ripple marks, thin layering, differential erosion, and curvilinear fracturings. Some of them are interpreted as lithified clastic sediments. The lithification could have taken place at depth or at the surface, resulting in a type of duricrust. The origin of the sediments is unknown but could be aeolian, volcanic, or related to impacts or to turbidity currents.     

Do the tropical freshwater fishes feed on aquatic fungi?

Consumption and processing of allochthonous plant litter by fishes is more common in tropical than temperate streams and rivers. Therefore, aquatic hyphomycetes in water (filtration), leaf litter (bubble chamber incubation), and fecal pellets (direct observation and inoculation to sterile leaf litter) of three dominant fishes belonging to the family Cyprinidae (Aplocheilus lineatus, Puntius filamentosus, and Rasbora daniconius) in two locations of the River Kali of the Western Ghats, India, were evaluated during postmonsoon season. Spores of 14 and 9 species of aquatic hyphomycetes were recovered on filtering water samples of Kaiga stream and Kadra dam with equal number of spores (32 spores · 100 mL⁻¹) and high Shannon diversity in Kaiga stream. In a bubble chamber incubation of leaf litter, 16 and 9 species were recovered from Kaiga stream and Kadra dam with high spore output (1122 versus 324 spores per mg dry mass) and high Shannon diversity in Kaiga stream. Both direct and indirect methods of examination of fecal pellets of fishes revealed more species in Kaiga stream than Kadra dam (4–7 versus 1–4 species). The spore release in leaf litter incubated with fecal pellets ranged from 2.3 to 98 spores·mg⁻¹·d⁻¹ with the highest Aplocheilus lineatus in Kaiga stream; while in Kadra dam, it was from 0.02 to 22.9 spores·mg⁻¹·d⁻¹ with the highest in Puntius filamentosus. The Shannon diversity of aquatic hyphomycetes was high in fecal pellets of Aplocheilus lineatus of Kaiga stream and Rasbora daniconius of Kadra dam. The top-ranked five species of aquatic hyphomycetes differed in water, leaf litter, and fish fecal pellets; however, Triscelophorus konajensis was common for all. All five top-ranked species of aquatic hyphomycetes in feces produced multicelled spores; thus, they were likely to have a better chance of viability through gut passage than single-celled spores. Preferential feeding, fungi in gut and feces, and survival and dissemination of spores by invertebrates and fishes with reference to aquatic hyphomycetes were discussed.     

Deep oxygenated ground water: anomaly or common occurrence?

Contrary to the prevailing notion that oxygen-depleting reactions in the soil zone and in the aquifer rapidly reduce the dissolved oxygen content of recharge water to detection limits, 2 to 8 milligrams per liter of dissolved oxygen is present in water from a variety of deep (100 to 1000 meters) aquifers in Nevada, Arizona, and the hot springs of the folded Appalachians and Arkansas. Most of the waters sampled are several thousand to more than 10,000 years old, and some are 80 kilometers from their point of recharge.     

Oceans on titan?

If global oceans of methane exist on Titan, the atmosphere above them must be within 2 percent of saturation. The two Voyager radio occultation soundings, made at low latitudes, probably occurred over land, since they imply a relative humidity less, similar 70 percent near the surface. Oceans might exist at other low-latitude locations if the zonal wind velocities in the lowest 3 kilometers are 相似文献   

Effect of rare earth application on the growth of Trichoderma spp. and several plant pathogenic fungi

Rare earth elements (REEs) enriched fertilisers are currently used in China for soil and foliar applications to crops, but little is known about the effect of REEs applications on the growth of beneficial and detrimental soilborne microorganisms. The growth of biological control agents Trichoderma atroviride strain P1, Trichoderma harzianum strain A6 and strain T22, plant pathogens Botrytis cinerea, Alternaria alternata, Fusarium solani, Rhizoctonia solani and Sclerotinia scleroti…