Forage Response and Economic Benefits to Weed Management in Grasslands

A common question among managers of grazing operations is “At what level of weed pressure does it become economical to apply herbicides on pastures?” Unfortunately, there isn’t just one answer to this question as production goals and practices differ between operations and even within an operation over time. Regardless, the real question being ask is if weed control will increase profit per acre. There are three basic avenues that may be taken to improve profit per acre through weed control. The first is to increase the carrying capacity of the grazing operation by controlling weeds and replacing them with desirable forage species that will support the required increase in animal units. The second is to use weed control to improve forage availability to the existing herd to support higher average daily gains (ADG) or improve body condition (BCS) of animals. The third is to simply improve animal health through control of toxic plants that may suppress animal performance or increase mortality. Here we will only focus on weed control for increased carrying capacity and improved animal performance

A Phase Lag between Disk and Corona in GRMHD Simulations of Precessing Tilted Accretion Disks

In the course of its evolution, a black hole (BH) accretes gas from a wide range of directions. Given a random accretion event, the typical angular momentum of an accretion disc would be tilted by $\sim$60$^\circ$ relative to the BH spin. Misalignment causes the disc to precess at a rate that increases with BH spin and tilt angle. We present the first general-relativistic magnetohydrodynamic (GRMHD) simulations spanning a full precession period of highly tilted (60$^\circ$), moderately thin ($h/r=0.1$) accretion discs around a rapidly spinning ($a\simeq0.9$) BH. While the disc and jets precess in phase, we find that the corona, sandwiched between the two, lags behind by $\gtrsim 10^{\circ}$. For spectral models of BH accretion, the implication is that hard non-thermal (corona) emission lags behind the softer (disc) emission, thus potentially explaining some properties of the hard energy lags seen in Type-C low frequency quasi-periodic oscillations in X-Ray binaries. While strong jets are unaffected by this disc-corona lag, weak jets stall when encountering the lagging corona at distances $r \sim 100$ black hole radii. This interaction may quench large-scale jet formation.Comment: 5 pages, 4 figures, submitted to MNRAS, see YouTube playlist for 3D renderings: https://www.youtube.com/playlist?list=PLDO1oeU33GwmwOV_Hp9s7572JdU8JPSS

The Spectrum of Sulphur, S II

One hundred and eighty-three lines are classified in the spectrum of S II. Thirty-three terms of the quartet system and thirty-six of the doublet system are determined and correlated with the electron configurations by means of the Hund theory. The ionization potential of the S II ion is fixed at 23.3±0.1 volts

Managing Vegetation In Grassland Habitats To Enhance Livestock Or Wildlife Objectives

Sustainably stewarding grassland systems involves applying various practices to manipulate forage interactions with other plants, the environment, and grazing animals to meet resource manager objectives. These interactions can result in invasion or encroachment and increased abundance of weeds which hinder attainment of management objectives. Weeds influence the structure and function of pasture ecosystems whether forages are grown in improved pastures, rangeland, or grassland communities. They degrade pasture quality and reduce livestock performance by interfering with forage establishment, yield, and quality by competing for resources. Weeds reduce the feed value of forage, decrease pasture carrying capacity, and can be toxic or unpalatable to livestock. Managing weeds requires use of vegetation management tools that favor desirable forages. Herbicides can be a catalyst that expedite grassland renovation, improve the forage resource, and increase carrying capacity. Corteva Agriscience has a variety of herbicide products that provide superior control of herbaceous and woody weeds, while maintaining the desirable vegetation. These herbicides were designed and developed specifically for selective broadleaf weed control in rangeland, pastures, rights-of-way, non-cropland, and natural areas. Active ingredients historically used include aminopyralid, triclopyr, fluroxypyr, clopyralid, and picloram. Rinskor™ active and Arylex™ active are new herbicide active ingredients from Corteva Agriscience™ and are members of a unique synthetic auxin chemotype, the arylpicolinates (HRAC group O / WSSA group 4). Members of the arylpicolinate family demonstrate novel and differentiated characteristics in terms of use rate, spectrum, weed symptoms, environmental fate, and molecular interaction as compared to other auxin chemotypes. When applied as a stand-alone treatment or in various mixes these products are safe to desirable grass species and control key herbaceous and woody weeds in the genera Ambrosia, Acacia, Carduus, Centaurea, Cirsium, Mimosa, Prosopis, Ranunculus, Rumex, Sida, Solanum, Taraxacum, and more

Paradoxes and Innovation in Family Firms: The Role of Paradoxical Thinking

Scholars stress that family firms are inherently paradoxical, and that tensions, such as tradition versus change, family liquidity versus business growth, and founder control versus successor autonomy, can both inhibit and foster innovation. Further, theorists propose that firms led by paradoxical thinkers are more likely to manage these tensions and fuel innovative behavior. Leveraging family business and organizational paradox literatures, this multi-stage exploratory study develops measures of paradoxical tensions and paradoxical thinking in family firms, and tests these propositions. Findings indicate that paradoxical tensions may stymie innovative behavior, but that leaders' paradoxical thinking is positively related to innovative behavior

Wave-length standards in the extreme ultra-violet spectra of carbon, nitrogen, oxygen and aluminum

Wave-length determinations.—The wave-lengths of lines in the extreme ultra-violet spectra of carbon, nitrogen, oxygen and aluminum have been determined with an accuracy of .01 to .04 A by direct comparison with iron standards. pp′ groups in carbon CIII and nitrogen NIV-pp′ Groups of carbon CIII and nitrogen NIV have been completely resolved into six components and the ratio p1p2/p2p3 found to be 2.47 and 2.33 respectively