Chemical Weed Control in Shelterbelts

The most important single factor in successful shelter-belt establishment in the Northern Great Plains is elimination of weed and grass competition. While removal if competing vegetation between the tree rows can readily be accomplished with machinery, removal of such vegetation in the tree rows is a different problem. Hand hoeing is effective, but involves a great deal of time and labor. No mechanical means of removing competing vegetation from the row has proven entirely satisfactory

Administrators\u27 Capacity for Supporting Reform-Oriented Science Instruction: An Urban School District Case Study

Secondary school administrators play a vital role as instructional leaders, but little is known about their knowledge of science practices and perceptions of strategies for supporting reform-oriented science instruction. This multiphase, mixed-methods Q-Methodology study explored administrators\u27 perceptions of instructional leadership and, in particular, high-quality science instruction. After a concourse of 40 items was developed through a review of literature and an expert panel, n = 22 administrators from one urban school district completed a Q-sort and a post-sort questionnaire in which they commented on a lesson excerpt. Principal components analysis with varimax rotation was used to assimilate the participants into three factors or groups explaining 40% of the variance. A subsample (n = 14) of administrators then participated in focus groups to engage in collective sensemaking. Although administrators consistently valued positive teacher-student relationships and had high expectations for all students over other managerial duties, perceptions of how to support teachers and their ability to detect evidence-based science pedagogy (NGSS), differed. Administrators with a science background or more experience as an administrator were more familiar with some of the evidence-based instructional strategies for science included in the sample lesson. Administrators without such a background tended to emphasize general pedagogical techniques. We discuss implications for the development of school leaders with varying disciplinary backgrounds as one component of building districts\u27 capacity for high-quality science instruction

Chemical Control of Woody Plants

Many woody plants are problems in rangeland, along roadsides, under utility lines, and along irrigation and drainage ditches. It is often desirable to control these plants on rights-of-way, but it is advisable to study the situation before controlling them on rangeland. Chemicals used to control undesirable woody species may also kill desirable range £orbs and woody plants. One should be certain that the range forage will be improved before he does any large-scale spraying. It may be advisable to conduct a few small-area trials before the entire range is treated. To make spraying pay on rangeland it is desirable to follow good range management so that grasses will take over as the woody plants die out. Even though the grasses are present, they will not spread after the woody plants have been killed except under light grazing or no grazing conditions. Many of the grass plants should be allowed to produce seed. In South Dakota research has been limited to the use of chemicals for the control of buckbrush, sagebrush and poison ivy. Therefore, most of the information presented was obtained from the North Central Weed Control Conference and from states that have more woody plant problems than South Dakota. Most of the suggestions offered here have not been tried extensively in South Dakota, but they have proved to be satisfactory under similar conditions

Thinning Black Hills Pine

Guide to thinning Black Hills pine trees to eliminate the least productive, low quality trees giving room to remaining trees and increased rate of growth. Discusses are reason not to clear-cut, types of thinning, spacing guides, slash disposal, equipment needed, and government cost-share programs

Cutting Posts and Poles for Profit

Guide to cutting posts and poles for profit discusses thinning a timber stand and how to cut an acceptable product

Cutting Posts and Poles for Profit

This publication provides guidance on harvesting timber for posts and poles. It includes suggestions to check with the farm forester for technical assistance, secure a market for the product before cutting, cut the post to the proper length with square-cut ends, and limb smoothly

Pruning Black Hills Pine

Guide to pruning Black Hills pine addresses selecting crop trees, equipment needed for pruning, safety, and government cost-share

Spatio-temporal correlations can drastically change the response of a MAPK pathway

Multisite covalent modification of proteins is omnipresent in eukaryotic cells. A well-known example is the mitogen-activated protein kinase (MAPK) cascade, where in each layer of the cascade a protein is phosphorylated at two sites. It has long been known that the response of a MAPK pathway strongly depends on whether the enzymes that modify the protein act processively or distributively: distributive mechanism, in which the enzyme molecules have to release the substrate molecules in between the modification of the two sites, can generate an ultrasensitive response and lead to hysteresis and bistability. We study by Green's Function Reaction Dynamics, a stochastic scheme that makes it possible to simulate biochemical networks at the particle level and in time and space, a dual phosphorylation cycle in which the enzymes act according to a distributive mechanism. We find that the response of this network can differ dramatically from that predicted by a mean-field analysis based on the chemical rate equations. In particular, rapid rebindings of the enzyme molecules to the substrate molecules after modification of the first site can markedly speed up the response, and lead to loss of ultrasensitivity and bistability. In essence, rapid enzyme-substrate rebindings can turn a distributive mechanism into a processive mechanism. We argue that slow ADP release by the enzymes can protect the system against these rapid rebindings, thus enabling ultrasensitivity and bistability

Pruning Shade Trees

This publication provides guidance on when and how to prune and the necessary equipment, as well as shaping the cuts, wound dressing and safety precautions