Assessing the contribution of vegetation to slope stability

Many embankments and cuttings associated with the transportation infrastructure in the UK are only marginally stable. Engineering techniques such as soil nailing, geosynthetic reinforcement, improved drainage and ground improvement by stabilisation are available to improve stability but the cost can be high. A lower cost solution may be to utilise vegetation, either self seeded or planted. The benefits and drawbacks associated with vegetation have been the subject of some debate. The problems caused by vegetation in relation to building foundations are well documented and confirm that vegetation can have very significant influences on geotechnical parameters. Appropriate properly maintained vegetation can have the same significant influence to help provide additional stability to soil slopes. This paper considers the potential engineering influences of vegetation and how it can be characterised on site within a geotechnical framework for stability assessments. The direct reinforcement available from the roots of trees and shrubs is identified as providing one of the most significant contributions to slope stability. Case studies in the UK, Greece and Italy demonstrate how results from in-situ root pull out tests may be used to estimate the potential reinforcement forces available from the roots. A scheme is presented to designate zones of influence within the soil according to the size and nature of the vegetation

FACTORS INFLUENCING SUPPORT FOR RURAL LAND USE CONTROL : A COMMENT

Land ownership characteristics such as the quantity of land owned, quality of land parcels, and location of land describe important dimensions of landed wealth. Landed wealth is expected to be an important factor influencing support for rural land use control. This factor was not discussed in the April (1999) article by McLeod, Woirhaye, and Menkhaus (1999). We suggest that this factor contributes to understanding variation in support for rural land use control.Land Economics/Use,

UNDERSTANDING THE DEMAND FOR FARMLAND PRESERVATION: IMPLICATIONS FOR MICHIGAN POLICIES

The diversity of opinion on farmland preservation suggests that a close look at the issue is warranted as state and local governments consider how best to preserve the state's farmland resource. Public support for farmland preservation programs will be required if those programs are to be successful and will only be forthcoming if there is greater agreement about questions that underlie the policy debate. These questions include whether farmland loss is occurring, whether farmland preservation is needed, how farmland preservation programs should be designed, and what farmland should be preserved. This paper discusses each of these issues, in turn, and describes how current Michigan farmland preservation efforts are or are not addressing them.Land Economics/Use,

PUBLIC OPINIONS ABOUT FARMLAND AND FARMLAND PRESERVATION: RESULTS FROM A SURVEY IN KENT COUNTY, MICHIGAN

Retention of agricultural land has become a principal goal for Michigan and its local governments. Purchase of Development Rights is one farmland preservation policy option being considered by many local units of government. Maximizing the benefits from such a program requires an understanding of why the public is interested in farmland preservation. The type and magnitude of benefit will differ depending upon which land is targeted for preservation. This paper reports the results of a survey conducted to ask residents of Kent County, Michigan, what characteristics of farmland are important and how farmland preservation programs should be targeted. The survey also asked whether respondents would support farmland preservation. Results indicate that characteristics of farmland do matter and that support of a farmland preservation program is likely driven by program cost.Land Economics/Use,

China Foreign Direct Investment: Greenfield, Mergers & Acquisition, Or Joint-Venture

Foreign investment in China is once again beginning to grow as the economy sees signs of recovery.  Companies looking to establish a presence in mainland China, have three options to evaluate and choose between 1) entering into a joint-venture, 2) acquiring an existing company, or3) developing an organization via Green Field development.  This paper delves deeper into these three options, outlining the benefits and pitfalls of each approach.  The purpose is to provide the reader with a general overview of investment vehicles available in China and to guide the business professional in a course of action, including the social impact of these options

An Evaluation for Modification (Shorter) of the Kirby-Bauer Susceptibility Test

The Kirby-Bauer test for determining antibiotic effectiveness is widely used in laboratories. The 10 to 20 hour incubation time needed to obtain useful results is a disadvantage of that test. This experimental research was developed to test a modification which could provide useful results in 5 hours. The modification employed in this experimental technique used an increased inoculum at a 1.0 McFarland standard instead of the customary 0.5 standard. The 2 to 5 hour incubation period in the trypticase soy broth was deleted. The Mueller Hinton plates were incubated for 5 hours and then observed for resistant and/or sensitive patterns. Controls for this experimental study were the results of the standard Kirby-Bauer test as recorded by the day and night shift personnel of the Medical Center at Bowling Green. Bowling Green, Kentucky. Tested were 33 cultures of Escherichia coil, 33 cultures of Pseudomonas aeruginosa, and 33 cultures of Staphylococcus aureus. The same cultures of each organism were tested using the 5 hour experimental procedure. A pure culture was inoculated in a tube of trypticase soy broth to a final turbidity equal to a 1.0 McFarland standard. A portion of this inoculum was swabbed onto the entire surface of a Mueller Hinton plate. Antibiotic discs were placed on the agar surface and tapped gently to insure contact. The plates were put into a 37°C incubator for 5 hours then removed to observe zones of no growth. Results were classified as either resistant or sensitive ; intermediate was deleted. If a zone of no growth was closer to the sensitive reading than the resistant reading for an antibiotic, the bacterium was considered sensitive to that antibiotic. The same was true for resistant readings. Measurements were taken with a caliper dial. For the two procedures, identical results occurred 99.7% of the time for Pseudomonas aeruginosa. For Escherichia coli 96.8% of the tests were identical, and with Staphylococcus aureus 93.2% of the tests were identical. Strains of Staphylococcus aureus that were sensitive to penicillin G and ampicillin with the standard Kirby-Bauer test were resistant with the 5 hour test. It occurred 10 times with a quality control stock culture and 1 time with a clinical isolate for ampicillin. It occurred 9 times with a quality control stock culture and 1 time with a clinical isolate for penicillin G. It is likely that the differences with Staphylococcus aureus for ampicillin and penicillin G are due to the interaction between the organism and the two antibiotics. Further studies are needed to determine whether or not a 1 to 2 hour extension of the incubation time could alleviate this problem

(A) survey of the Irish theater ..

Typewritten sheets in cover. Thesis (M.A.)--Boston University Bibliography: 2 p. at end