Alfven waves in the solar corona

Alfvén waves, transverse incompressible magnetic oscillations, have been proposed as a possible mechanism to heat the Sun's corona to millions of degrees by transporting convective energy from the photosphere into the diffuse corona. We report the detection of Alfvén waves in intensity, line-of-sight velocity, and linear polarization images of the solar corona taken using the FeXIII 1074.7-nanometer coronal emission line with the Coronal Multi-Channel Polarimeter (CoMP) instrument at the National Solar Observatory, New Mexico. Ubiquitous upward propagating waves were seen, with phase speeds of 1 to 4 megameters per second and trajectories consistent with the direction of the magnetic field inferred from the linear polarization measurements. An estimate of the energy carried by the waves that we spatially resolved indicates that they are too weak to heat the solar corona; however, unresolved Alfvén waves may carry sufficient energy.     

Efficacy of different temperate pasture species to reduce nitrogen leaching from cattle urine applied in different seasons: A soil lysimeter study

A soil lysimeter field study assessed the efficacy of different pasture species to reduce nitrogen (N) leaching loss from cow urine deposited in different seasons. A single application of cow urine (¹⁵N‐labelled; equivalent to 622 kg N ha^?1) was applied in three different seasons (summer, autumn or winter) to three pasture species monocultures (perennial ryegrass, plantain or lucerne) on a free‐draining volcanic soil and monitored over 362 days. Leachate analyses revealed consistently large leaching losses of inorganic‐N from lucerne (>200 kg N ha^?1) across different urine application times due to the relatively low plant growth rates during winter (<15 kg DM ha^?1 day^?1) that led to low total recovery of urine‐N by lucerne plants (<20% of the applied urine‐¹⁵N). Conversely, plant uptake of the urine‐N was higher by plantain (ranging from 30% to 45% of that applied) driven by moderately higher winter plant growth rates (30 to 60 kg DM ha^?1 day^?1). Plantain exhibited large seasonal variation in its efficacy to reduce urine‐N leaching relative to ryegrass (ranging from 15% to 50% reduction for summer or winter urine applications, respectively) with an overall reduction of 39% in the total amount of inorganic‐N leached across the three seasons (53 vs. 87 kg N ha^?1 leached relative to ryegrass). This study has demonstrated the potential benefit of using plantain to reduce N leaching losses from urine deposited in the summer to winter grazing period. However, further research is required to quantify the effects of plantain on annual N leaching losses from grazed pastoral systems.     

Practical means for estimating pork carcass composition

Three hundred sixty-one market-weight barrow and gilt carcasses were physically dissected into bone, skin, fat and muscle. A three-variable multiple linear regression equation containing the same independent variables (warm carcass weight, 10th rib loin muscle area and 10th rib fat depth) used (U.S.) to determine pork carcass lean weight was found to be the most practical means for predicting weight of muscle standardized to 10% fat. Multiple linear regression equations containing more than three independent variables produced only slight improvements in R2 values; however, the standard deviation about the regression line was not greatly improved by the addition of more independent variables to this three-independent-variable regression model. A single multiple linear regression equation using the three independent variables above may not be adequate to describe variation over the entire live-weight range for all hogs marketed in the U.S. For most accurate muscle weight prediction, different equations should be used for weight subclasses with one equation for carcasses under 100 kg and another for those heavier than 100 kg. A single prediction equation for muscle weight was adequate for carcasses of both barrows and gilts.     

Relationships among intramuscular collagen, serum hydroxyproline and serum testosterone in growing rams and wethers

Concentration and maturation of collagen and serum concentrations of hydroxyproline and testosterone were determined in growing rams and wethers to characterize developmental changes in collagen associated with a representative testicular steroid. Groups of eight rams and eight wethers were slaughtered at 12, 18, 24 and 30 wk of age. Concentrations of collagen in longissimus, supraspinatus and infraspinatus muscles and serum hydroxyproline were greater (P less than .05) in rams than in wethers at all ages. Collagen stability, as measured by collagen solubility and thermal shrinkage temperature, was greater (P less than .05) in wethers than in rams. Differences in collagen stability and serum hydroxyproline concentration indicated that collagen synthesis and turnover were more rapid in rams than in wethers. Serum hydroxyproline decreased (P less than .05) and collagen solubility decreased (P less than .05) with age, indicating that collagen turnover was occurring most rapidly in 12-wk-old lambs and that collagen maturation was predominant in 24- to 30-wk old lambs. Testosterone parameters measured in rams were unrelated within groups to collagen characteristics, possibly reflecting the high variability in testosterone secretion and the slow development of collagen. However, rams as young as 12 wk of age were under the influence of testosterone, and differences in collagen between rams and wethers were apparent at that time.     

Influence of surface‐applied poultry manure on topsoil and subsoil acidity and salinity: A leaching column study

It has been suggested that surface applications of animal manure can ameliorate both top and subsoil acidity. For that reason, the effects of surface incorporation (0–5 cm) of a high rate of poultry manure to an acid soil on pH and exchangeable and soluble Al in the top‐ and subsoil were investigated in a leaching column study. During the experimental period of 108 d, columns received a total of 875 mm with leaching events occurring after 9, 37, 58, and 86 d. Incorporation of poultry manure into the surface 5 cm resulted in a large rise in pH measured in both 1M KCl and in soil solution. This liming effect was attributed primarily to the substantial CaCO₃ content of poultry manure. In the 15–45 cm layer, pH_KCl was not significantly different between poultry manure and control treatments but surprisingly, soil‐solution pH was substantially less in the poultry‐manure treatments. Exchangeable Al was significantly less in poultry manure than in control in all soil layers although the effect was most marked in the 0–5 cm layer. However, although concentrations and activities of monomeric Al (Al_mono), and the proportion of total Al present as Al_mono, in soil solution were lower under poultry manure than in control in the 0–5 cm layer, the reverse was, in fact, the case in lower soil horizons. This was attributed to a soluble‐salt effect, originating from the large cation content of poultry manure, displacing exchangeable Al³⁺ and H⁺ back into soil solution. Indeed, electrical conductivity and concentrations of Ca²⁺, Mg²⁺_, K⁺, and Na⁺ in soil solution were substantially higher in the poultry‐manure than in the control treatments at all soil depths. Poultry‐manure applications also resulted in substantial increases in the concentrations of Ca²⁺_, Mg²⁺_, K⁺, Na⁺, Al_mono, NH , and NO in leachates, particularly at the fourth leaching. It was concluded that although surface application of poultry manure can raise soil pH in the topsoil, increases in soluble‐salt concentrations in soil solution can greatly modify this effect in the subsoil.