Global mineralogical and aqueous mars history derived from OMEGA/Mars Express data

Global mineralogical mapping of Mars by the Observatoire pour la Mineralogie, l'Eau, les Glaces et l'Activité (OMEGA) instrument on the European Space Agency's Mars Express spacecraft provides new information on Mars' geological and climatic history. Phyllosilicates formed by aqueous alteration very early in the planet's history (the "phyllocian" era) are found in the oldest terrains; sulfates were formed in a second era (the "theiikian" era) in an acidic environment. Beginning about 3.5 billion years ago, the last era (the "siderikian") is dominated by the formation of anhydrous ferric oxides in a slow superficial weathering, without liquid water playing a major role across the planet.     

Influence of Cow Age on Grazing Distribution in a Mixed-Conifer Forest

Optimal distribution of cattle on forested rangelands has long been a subject of concern specifically related to uniform and sustainable use of forage resources. Our objective was to determine if cow age influenced distribution and resource use on forested rangelands. This study was conducted from 1991 to 2001 at the US Department of Agriculture Starkey Experimental Forest and Range, northeastern Oregon, a mixed-conifer forested rangeland. We used 43 039 locations of cattle taken from 1 h prior to sunrise until 4 h after sunrise and 4 h prior to sundown until 1 h after sundown from 15 July to 30 August to evaluate cattle distribution patterns during peak foraging time. Cattle were grouped into four age classes: 2- and 3-yr-old cattle, 4- and 5-yr-old cattle, 6- and 7-yr-old cattle, and cattle ≥ 8 yr old. All age classes preferred areas with gentler slopes (P &spilt; 0.05), westerly aspects (P &spilt; 0.05), farther from water (P &spilt; 0.05), and with greater forage production (P &spilt; 0.05) than pasture averages. Cattle older than 3 yr of age selected areas with less canopy closure (P &spilt; 0.05) than the mean value for the pasture. Young cows (&spilt; 4 yr old) selected lower elevations and steeper slopes than the oldest cows (P &spilt; 0.05). In summary, cow age and correspondingly its experience directly influences distribution patterns and forage resource use of cattle at the Starkey Experimental Forest and Range.     

Production performance of sheep and goat breeds at a farm in a semi-arid region of Namibia

Tropical Animal Health and Production - This study retrospectively investigated the effect of breed and season on the lambing/kidding dynamics, growth performance, neonatal viability, and weaning...     

Changes In Moisture Retention Properties Of Five Waste Materials During Short-Term Mesophilic Composting

The effect of composting for a maximum period of 90 days on the water retention characteristics of five waste materials — coconut dust (CD) (also known as coir), mixed sawdust (SD), rice hulls (RH), sapwood sawdust (SW) and heartwood sawdust (HW) was investigated with or without the addition of nitrogen. Total porosity (TP), easily available water (EAW) and water buffering capacity (WBC) were increased with time in all five materials, while air space (AS) was decreased in all the materials except in rice hulls, where it increased. Of all the materials, CD retained the most moisture and RH the least after 90 days. SD, SW and HW had similar characteristics, and separation for utilization is unnecessary. Nitrogen addition did not affect TP and AS but slightly increased EAW and WBC. Formulation and management of potting media using these materials should take into account these moisture retention changes for maximum benefit to plants grown in them.