scholarly journals The Selection, Testing, and Application of Ecological Bioindicator Birds: A Case Study of the Bale Mountains, Southeast Ethiopia

1970 ◽  
Vol 11 (2) ◽  
pp. 187-208
Author(s):  
Asefa Addisu ◽  
Mengesha Girma
Keyword(s):  
Effective Means ◽  
Cost Effective ◽  
Sampling Period ◽  
Ecological Monitoring ◽  
Grazing Pressure ◽  
Livestock Grazing ◽  
Bioindicator Species ◽  
Heavy Grazing ◽  
Southeast Ethiopia ◽  
Selection Testing

The interest in using ecological bioindicators - species or higher taxa, whose presence/absence or abundance reflect the abiotic or biotic state of an ecosystem - as cost-effective means of ecological monitoring has been globally increasing. The main aim of this study was to assess if such ecological bioindicator species could be identified within Afromontane grassland avifauna that would be used for monitoring the effects of livestock grazing on ecosystem in the Bale Mountains of Ethiopia. We collected data on birds and vegetation structure along 14 transects each in the light (protected) and heavy (unprotected) grazing sites in June 2014 (referred to as the first sampling period) and in December 2014 (the second sampling period). Then, we (i) initially identified potential bioindicator species for the light grazing site, based on data collected during the first sampling period; (ii) examined relationships between abundance of these bioindicators and level of grazing pressure; (iii) tested the consistency of those initially selected bioindicator species, based on independent data collected during the second sampling period. We used the Indicator Value (IndVal) Analysis method to identify bioindicator species for the light grazing site. Species with significant IndVal>60% were considered as potential bioindicator for the site compared to the heavy grazing site. Six species were initially identified as potential bioindicators from the first sampling period dataset, and four of these species were again consistently identified from the second sampling period. Furthermore, abundance of the bioindicators had significantly declined with increasing grazing pressure, but positively correlated with four habitat variables (i.e. heights of shrub, herb and grass, and cover of shrub). These findings suggest that those consistently identified four species represent suite of reliable bioindicators that can successfully be used for monitoring of changes in habitat structure in the site. Recommendations on how to apply these findings for ecological monitoring are provided.

Effect of livestock grazing on physical properties of a cracking and self-mulching Vertisol

2002 ◽  
Vol 42 (2) ◽  
pp. 129 ◽  
Author(s):  
G. Taddese ◽  
M. A. Mohamed Saleem ◽  
W. Ayalneh
Keyword(s):  
Moisture Content ◽  
Physical Properties ◽  
Addis Ababa ◽  
Grazing Pressure ◽  
Livestock Grazing ◽  
Control Treatment ◽  
Soil Matrix ◽  
Heavy Grazing ◽  
The Impact ◽  
Grazing Pressures

The impact of grazing on physical properties of Vertisol was studied from 1996 to 2000 in the Ethiopian highlands. The study was conducted at 2 sites with 0–4 and 4–8% slopes at Tero Jemjem watershed in Ginchi, 80 km west of Addis Ababa. The objective of the study was to compare selected soil physical properties at different grazing pressures and slopes. The stocking rate was moderate grazing 1.8 animal-unit months per hectare (1.8 AUM/ha), heavy grazing 3.0 AUM/ha and a control treatment with no grazing. The result showed that heavy grazing pressure removed grass cover, which consequently enhanced soil cracking. Effect of livestock trampling on soil resistance to penetration (indicated by penetrometer readings) was higher in the heavily grazed plots than in non-grazed plots. Penetrometer readings were influenced by soil moisture content. Low moisture content was observed in the heavily grazed plots at both sites. The infiltration of accumulated water to the soil matrix was lower in heavily grazed plots.

Parallel Computing for Tire Simulations

2011 ◽  
Vol 39 (3) ◽  
pp. 193-209 ◽  
Author(s):  
H. Surendranath ◽  
M. Dunbar
Keyword(s):  
High Performance ◽  
Effective Means ◽  
Cost Effective ◽  
Turnaround Time ◽  
Careful Consideration ◽  
Rolling Contact ◽  
Element Analysis ◽  
Parallel Solvers ◽  
Design Changes ◽  
Highly Nonlinear

Abstract Over the last few decades, finite element analysis has become an integral part of the overall tire design process. Engineers need to perform a number of different simulations to evaluate new designs and study the effect of proposed design changes. However, tires pose formidable simulation challenges due to the presence of highly nonlinear rubber compounds, embedded reinforcements, complex tread geometries, rolling contact, and large deformations. Accurate simulation requires careful consideration of these factors, resulting in the extensive turnaround time, often times prolonging the design cycle. Therefore, it is extremely critical to explore means to reduce the turnaround time while producing reliable results. Compute clusters have recently become a cost effective means to perform high performance computing (HPC). Distributed memory parallel solvers designed to take advantage of compute clusters have become increasingly popular. In this paper, we examine the use of HPC for various tire simulations and demonstrate how it can significantly reduce simulation turnaround time. Abaqus/Standard is used for routine tire simulations like footprint and steady state rolling. Abaqus/Explicit is used for transient rolling and hydroplaning simulations. The run times and scaling data corresponding to models of various sizes and complexity are presented.

Exploring the Benefits of Early Contractor Involvement (ECI) and the Mechanism for Automated 5D BIM Quantification Process in Offsite Modular Construction

2016 ◽  
Author(s):  
Tochukwu Moses ◽  
David Heesom ◽  
David Oloke ◽  
Martin Crouch
Keyword(s):  
Effective Means ◽  
Cost Effective ◽  
Modular Construction ◽  
Automated Quantification ◽  
Building Information ◽  
Project Risks ◽  
Value Add ◽  
The Uk ◽  
The Impact ◽  
Level 2

The UK Construction Industry through its Government Construction Strategy has recently been mandated to implement Level 2 Building Information Modelling (BIM) on public sector projects. This move, along with other initiatives is key to driving a requirement for 25% cost reduction (establishing the most cost-effective means) on. Other key deliverables within the strategy include reduction in overall project time, early contractor involvement, improved sustainability and enhanced product quality. Collaboration and integrated project delivery is central to the level 2 implementation strategy yet the key protocols or standards relative to cost within BIM processes is not well defined. As offsite construction becomes more prolific within the UK construction sector, this construction approach coupled with BIM, particularly 5D automated quantification process, and early contractor involvement provides significant opportunities for the sector to meet government targets. Early contractor involvement is supported by both the industry and the successive Governments as a credible means to avoid and manage project risks, encourage innovation and value add, making cost and project time predictable, and improving outcomes. The contractor is seen as an expert in construction and could be counter intuitive to exclude such valuable expertise from the pre-construction phase especially with the BIM intent of äóÖbuild it twiceäó», once virtually and once physically. In particular when offsite construction is used, the contractoräó»s construction expertise should be leveraged for the virtual build in BIM-designed projects to ensure a fully streamlined process. Building in a layer of automated costing through 5D BIM will bring about a more robust method of quantification and can help to deliver the 25% reduction in overall cost of a project. Using a literature review and a case study, this paper will look into the benefits of Early Contractor Involvement (ECI) and the impact of 5D BIM on the offsite construction process.

scholarly journals mRNA-Based Vaccines

Vaccines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 390
Author(s):  
Frank Kowalzik ◽  
Daniel Schreiner ◽  
Christian Jensen ◽  
Daniel Teschner ◽  
Stephan Gehring ◽  
...  
Keyword(s):  
Large Scale ◽  
New Technologies ◽  
Vaccine Development ◽  
Effective Means ◽  
Cost Effective ◽  
Clinical Applications ◽  
Cell Mediated Immunity ◽  
Healthy Individuals ◽  
Emerging Pathogens ◽  
Cell Genome

Increases in the world’s population and population density promote the spread of emerging pathogens. Vaccines are the most cost-effective means of preventing this spread. Traditional methods used to identify and produce new vaccines are not adequate, in most instances, to ensure global protection. New technologies are urgently needed to expedite large scale vaccine development. mRNA-based vaccines promise to meet this need. mRNA-based vaccines exhibit a number of potential advantages relative to conventional vaccines, namely they (1) involve neither infectious elements nor a risk of stable integration into the host cell genome; (2) generate humoral and cell-mediated immunity; (3) are well-tolerated by healthy individuals; and (4) are less expensive and produced more rapidly by processes that are readily standardized and scaled-up, improving responsiveness to large emerging outbreaks. Multiple mRNA vaccine platforms have demonstrated efficacy in preventing infectious diseases and treating several types of cancers in humans as well as animal models. This review describes the factors that contribute to maximizing the production of effective mRNA vaccine transcripts and delivery systems, and the clinical applications are discussed in detail.

Rangeland responses to pastoralists' grazing management on a Tibetan steppe grassland, Qinghai Province, China

2016 ◽  
Vol 38 (1) ◽  
pp. 1 ◽  
Author(s):  
Richard B. Harris ◽  
Leah H. Samberg ◽  
Emily T. Yeh ◽  
Andrew T. Smith ◽  
Wang Wenying ◽  
...  
Keyword(s):  
Plant Species ◽  
Temporal Trends ◽  
Winter Season ◽  
Grazing Pressure ◽  
Livestock Grazing ◽  
Western China ◽  
Permanent Plots ◽  
Sheep Grazing ◽  
Qinghai Province ◽  
Preferred Species

Livestock grazing is the principal land use in arid central Asia, and range degradation is considered a serious problem within much of the high-elevation region of western China termed the Qinghai-Tibetan Plateau (QTP). Rangeland degradation on the QTP is variously attributed to poor livestock management, historical-cultural factors, changing land tenure arrangements or socioeconomic systems, climate change, and damage from small mammals. Few studies have examined currently managed pastures using detailed data capable of isolating fine-scale livestock–vegetation interactions. The aim of the study was to understand how differences among livestock (primarily sheep) management strategies of pastoralists during winter affected subsequent rangeland condition and productivity. Plant species composition, annual herbage mass, and indicators of erosion were quantified during four summers (2009–2012) on winter pastures managed by 11 different pastoralists on QTP steppe rangeland in Qinghai Province, China. Data came from repeated-measurements on 317 systematically located permanent plots, as well as pastoralist interviews and the use of GPS-equipped livestock. Relationships between annual weather variation and herbage mass were modelled using an independent set of vegetation measurements obtained from livestock exclosures. Account was taken of inherent site differences among pastures. Annual variation in herbage mass was found to be best fitted by a model containing a negative function of winter-season temperature and a positive function of spring-season temperature. Accounting for annual and site effects, significant differences among pastoralists were found for most response variables, suggesting that individual heterogeneity among management approaches had consequences, even among neighbouring pastoralists. Annual herbage mass of preferred plant species was positively associated, whereas that of unpreferred species was negatively associated, with mean sheep density and intensity of use. However, the proportion of bare soil, an index of erosion, and annual herbage mass of unpreferred forbs were found to have positive relationships with sheep grazing pressure during the preceding winter, whereas live vegetation cover and annual herbage mass of preferred grasses were negatively related. Thus, on a spatial scale, pastoralists responded adaptively to the cover of preferred plant species while not responding to total annual herbage mass. Pastoralists stocked pastures more heavily, and livestock used regions within pastures more intensively, where preferred species had a higher cover. However, where sheep grazing pressure was high, downward temporal trends in the herbage mass of preferred species were exacerbated. Pastures that were stocked at a lower density did not experience the negative trends seen in those with a higher density.

Persistence and growth of Lotononis bainesii–Digitaria decumbens pastures: 1. Sheep stocking rate

1983 ◽  
Vol 101 (1) ◽  
pp. 1-7 ◽  
Author(s):  
A. Pott ◽  
L. R. Humphreys
Keyword(s):  
Bulk Density ◽  
Soil Bulk Density ◽  
Grazing Pressure ◽  
Stocking Rate ◽  
Digitaria Decumbens ◽  
Heavy Grazing ◽  
Cotton South ◽  
Seed Reserves ◽  
Stocking Rates

SUMMARYSheep were grazed for 2 years at stocking rates of 7, 14, 21 and 28/ha on a pasture comprising Lotononis bainesii and Digitaria decumbens cv. Pangola at Mt Cotton, south–east Queensland. There were six replicates of each treatment grazed in rotation with 3 days' grazing followed by 15 days' rest.The initial dominance of lotononis was lost after 6 months of grazing and lotononis failed to persist satisfactorily at any stocking rate. Demographic studies showed that lotononis behaved as a short-lived plant, predominantly annual, with some vegetative perennation as stolon-rooted units under heavy grazing. Soil seed reserves varied from 5800 to 400 m2 at the lightest and heaviest stocking rates respectively. Lotononis failed to regenerate under Pangola shading or inopportune high grazing pressure. Soil bulk density (0–7 cm) increased from 1·2 to 1·4 g/cm3 according to stocking rate.

A method for correcting acoustic finite-difference amplitudes for elastic effects

Geophysics ◽  
2014 ◽  
Vol 79 (4) ◽  
pp. T243-T255 ◽  
Author(s):  
James W. D. Hobro ◽  
Chris H. Chapman ◽  
Johan O. A. Robertsson
Keyword(s):  
Wave Equation ◽  
Finite Difference ◽  
Effective Means ◽  
Cost Effective ◽  
P Wave ◽  
S Waves ◽  
Velocity Models ◽  
Acoustic Simulation ◽  
Wide Range ◽  
Elastic Simulation

We present a new method for correcting the amplitudes of arrivals in an acoustic finite-difference simulation for elastic effects. In this method, we selectively compute an estimate of the error incurred when the acoustic wave equation is used to approximate the behavior of the elastic wave equation. This error estimate is used to generate an effective source field in a second acoustic simulation. The result of this second simulation is then applied as a correction to the original acoustic simulation. The overall cost is approximately twice that of an acoustic simulation but substantially less than the cost of an elastic simulation. Because both simulations are acoustic, no S-waves are generated, so dispersed converted waves are avoided. We tested the characteristics of the method on a simple synthetic model designed to simulate propagation through a strong acoustic impedance contrast representative of sedimentary geology. It corrected amplitudes to high accuracy for reflected arrivals over a wide range of incidence angles. We also evaluated results from simulations on more complex models that demonstrated that the method was applicable in realistic sedimentary models containing a wide range of seismic contrasts. However, its accuracy was reduced for wide-angle reflections from very high impedance contrasts such as a shallow top-salt interface. We examined the influence of modeling at coarse grid resolutions, in which converted S-waves in the equivalent elastic simulation are dispersed. These results provide some validation for the accuracy of the method when applied using finite-difference grids designed for acoustic modeling. The method appears to offer a cost-effective means of modeling elastic amplitudes for P-wave arrivals in a useful range of velocity models. It has several potential applications in imaging and inversion.

A Study on Small Scale Associated Gas FLNG Utilizing Small Scale LNG Carriers to Near-By Onshore LNG Plant

2016 ◽  
Author(s):  
X. C. Nguyen ◽  
Komla Miheaye ◽  
Mun-gyu Kim ◽  
Howard Newman ◽  
Dong-hoon Yoo ◽  
...  
Keyword(s):  
Short Range ◽  
Storage Capacity ◽  
Effective Means ◽  
Production Capacity ◽  
Cost Effective ◽  
Oil Fields ◽  
Small Scale ◽  
Associated Gas ◽  
Small Capacity ◽  
Stranded Gas

This study describes a FLNG specifically designed to monetize Associated Gas (AG) of producing oil fields located within convenient distance of an existing LNG Plant or Port with LNG storage facility. Limited production capacity combined with short range small capacity shuttles and limited LNG storage capacity, provide a cost effective means for LNG production. This FLNG is designed to service an existing industry and does not require development of stranded gas discoveries.

Yard-to-Mill Woodflow Scheduling by Microcomputer

1983 ◽  
Vol 7 (1) ◽  
pp. 50-53
Author(s):  
R. H. Hokans ◽  
W. B. Stuart
Keyword(s):  
Computer Program ◽  
Effective Means ◽  
Cost Effective ◽  
Scheduling Problem ◽  
Wood Procurement

Abstract Scheduling yard-to-mill woodflows requires the regular attention of wood procurement managers. While the calculations are routine, they are sufficiently time consuming to preclude evaluation of more than a first-guess schedule. A computer program implemented on a microcomputer provides a cost-effective means of doing the calculations and choosing an operationally feasible least-cost solution to the scheduling problem.

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