scholarly journals A field experiment to assess passage of juvenile salmonids across beaver dams during low flow conditions in a tributary to the Klamath River, California, USA

2019 ◽  
Author(s):  
Michael Moritz Pollock ◽  
Shari Witmore ◽  
Erich Yokel
Keyword(s):  
Field Experiment ◽  
Field Experiments ◽  
Coho Salmon ◽  
Effective Means ◽  
Late Summer ◽  
Cost Effective ◽  
Low Flow ◽  
Steelhead Trout ◽  
Juvenile Salmonids ◽  
Beaver Dams

ABSTRACTAcross Eurasia and North America, beaver (Castor spp), their dams and their human-built analogues are becoming increasingly common restoration tools to facilitate recovery of streams and wetlands, providing a natural and cost-effective means of restoring dynamic fluvial ecosystems. Although the use of beaver ponds by numerous fish and wildlife species is well documented, debate continues as to the benefits of beaver dams, primarily because dams are perceived as barriers to the movement of fishes, particularly migratory species such as salmonids. In this study, through a series of field experiments, we tested the ability of juvenile salmonids to cross constructed beaver dams (aka beaver dam analogues). Two species, coho salmon (Oncorhynchus kisutch) and steelhead trout (O. mykiss), were tracked using passive integrated transponder tags (PIT tags) as they crossed constructed beaver dams. We found that when we tagged and moved late-summer parr from immediately upstream of the dams to immediately downstream of them, most of them were detected upstream within 36 hours of displacement. By the end of a 21-day field experiment, 91% of the displaced juvenile coho and 54% of the juvenile steelhead trout were detected on antennas upstream of the dams while <1% of the coho and 15% of the steelhead trout were detected on antennas in the release pool below the dams. A similar but shorter 4-day pilot experiment with only steelhead trout produced similar results. In contrast, in a non-displacement experiment, juveniles of both species that were captured, tagged and released in a pool 50 m below the dams showed little inclination to move upstream. Finally by measuring hydraulic conditions at the major flowpaths over and around the dams, we provide insight into conditions under which juvenile salmonids are able to cross these constructed beaver dams, which should help guide future restoration efforts.

scholarly journals Effect of pesticide treatment of spring wheat plots on seed yields

2021 ◽  
pp. 117-125
Author(s):  
O. A. Demydov ◽  
A. A. Siroshtan ◽  
V. P. Kavunets ◽  
O. A. Zaima ◽  
S. F. Liskovskiy
Keyword(s):  
Spring Wheat ◽  
Field Experiments ◽  
Effective Means ◽  
Cost Effective ◽  
Initial Growth ◽  
Seeding Rate ◽  
Coleoptile Length ◽  
Wheat Varieties ◽  
Pesticide Treatment ◽  
Wheat Seeds

Introduction. High-quality varietal seeds, which can ensure a gain of 0.2–0.4 t/ha in the yields from their offspring, is one of the most important and cost-effective means to increase the gross grain collection of grain. Purpose. To study productive capacities of spring wheat seeds depending on treatment of fields with fungicides and insecticides. Materials and methods. The following indicators were evaluated: swelling activity, germination energy, laboratory germinability, initial growth strength, coleoptile length and the number of radicles. Seed samples that after pesticide treatment had showed the best results were tested in field experiments for productive capacities. The experimental plot area was 10 m2, in six replications. Seeds were sown with a seeder SN-10Ts after soybean with a seeding rate of 5 million germinable seeds per hectare. Spring wheat seeds produced in the experimental plots, which were treated with fungicides Akula (0.6 L/ha) and Soligor 425 EC (0.6 L/ha) and insecticides Fas (0.15 L/ha) and Karate Zeon 050 CS (0.15 L/ha) in organogenesis stages VI, VIII and X, were evaluated for productive capacities. The study was carried out on varieties MIP Zlata, Bozhena, MIP Raiduzhna and Diana. Results and discussion. Over the study years, the gain in the yields of spring wheat varieties grown from seeds of fungicide-treated plants was 0.23–0.36 t/ha; the gain in the yields of spring wheat varieties grown from seeds of insecticide-treated plants was – 0.24-0.31 t/ha. Pesticide-treated parental plants produced seeds with increased productive capacities: when such seeds were sown, the field germinability increased by 3-5%, and the plant survival – by 5-7%. Conclusions. The results indicate that the treatment of vegetating plants of spring wheat varieties in seed plots with fungicides and insecticides is a reliable way to obtain seeds with high productive capacities

scholarly journals Dry season survival of juvenile salmonids in an intermittent coastal stream

2018 ◽  
Vol 75 (5) ◽  
pp. 746-758 ◽  
Author(s):  
Jason L. Hwan ◽  
Albert Fernández-Chacón ◽  
Mathieu Buoro ◽  
Stephanie M. Carlson
Keyword(s):  
Coho Salmon ◽  
Late Summer ◽  
Dry Season ◽  
Steelhead Trout ◽  
Apparent Survival ◽  
Seasonal Drought ◽  
Antecedent Precipitation ◽  
Significant Survival Advantage ◽  
Significant Survival ◽  
Dry Seasons

We estimated dry season survival of imperiled salmonids in an intermittent coastal stream in California across 4 years (2009–2012). Our study encompassed two dry and two wet winters, allowing us to explore patterns of survival across and within dry seasons with different antecedent precipitation. Apparent survival of age-0+ steelhead trout (Oncorhynchus mykiss) was higher following wet winters compared with dry winters. Moreover, antecedent precipitation was positively correlated with cumulative survival of age-0+ steelhead. Within years, apparent survival of steelhead varied among weeks with a tendency to decrease in the late summer, indicating that fish exhibited some resistance to seasonal drought. Additionally, we found a slight but significant survival advantage for age-0+ coho salmon (Oncorhynchus kisutch) compared with equal-aged steelhead. Our results emphasize the influence of antecedent precipitation in driving the survival of imperiled salmonids and highlight that these fishes are somewhat resistant to seasonal drought, at least to a point.

Winter habitat preferences of juvenile salmonids in two interior rivers in British Columbia

1986 ◽  
Vol 64 (7) ◽  
pp. 1506-1514 ◽  
Author(s):  
S. Swales ◽  
R. B. Lauzier ◽  
C. D. Levings
Keyword(s):  
British Columbia ◽  
Chinook Salmon ◽  
Coho Salmon ◽  
Habitat Preferences ◽  
Main Channel ◽  
Steelhead Trout ◽  
Winter Habitat ◽  
Main Species ◽  
Juvenile Salmonids ◽  
Side Channels

The winter distribution and abundance of juvenile salmonids was investigated in various main channel and off-channel habitats in the Coldwater and Nicola rivers in the southern interior region of British Columbia. Catches were generally low in all main channel habitats, with coho salmon and steelhead trout being most abundant and chinook salmon and Dolly Varden char being present in smaller numbers. Coho salmon and steelhead trout catches were generally highest in pools with abundant instream and riparian cover. Steelhead trout was the main species in riprap bank protected areas, although catches were generally low. Highest overall catches were recorded in side channels and off-channel ponds, where water temperatures were usually several degrees higher than in the main river. Coho salmon was the main species in the two Coldwater off-channel ponds with overwintering populations of approximately 4000 and 1000 in 1- and 0.1-ha ponds, respectively (0.4–1.5 fish/m2): overwinter survival of coho salmon in the ponds was estimated to be 87 and 54%, respectively. High densities of coho salmon were also recorded in side channels on the Nicola River (1.5–1.8 fish/m2), together with smaller numbers of chinook salmon and steelhead trout (0.2–0.3 fish/m2). Growth in ponds and side channels appeared to be faster than in main channel habitats. We conclude that juvenile salmonids in the rivers investigated showed considerable habitat segregation during the winter. As in coastal rivers, juvenile coho salmon made extensive use of off-channel ponds, while rainbow trout and chinook salmon were generally most abundant in riprap and deep pools containing log debris, respectively.

Evaluation of visual survey methods for monitoring Pacific salmon (Oncorhynchus spp.) escapement in relation to conservation guidelines

2008 ◽  
Vol 65 (2) ◽  
pp. 212-226 ◽  
Author(s):  
Kendra R Holt ◽  
Sean P Cox
Keyword(s):  
Coho Salmon ◽  
Pacific Salmon ◽  
Survey Methods ◽  
Effective Means ◽  
Area Under The Curve ◽  
Cost Effective ◽  
Trend Detection ◽  
Conservation Units ◽  
Visual Survey ◽  
Wide Range

Canada’s Wild Salmon Policy requires that biological status of conservation units of Pacific salmon (Oncorhynchus spp.) be assessed regularly in relation to abundance-based benchmarks. Visual survey methods, in which periodic counts of spawning fish are made throughout a season, will likely be used for this purpose because they provide a cost-effective means of monitoring interannual trends in escapement. Trend detection performance for visual survey methods depends mainly upon consistency in (i) the ability of observers to detect fish and (ii) the annual timing of fish presence in the survey area. We developed a Monte Carlo simulation procedure to evaluate the ability of four visual survey methods (peak count, mean count, trapezoidal area-under-the-curve (AUC), and likelihood AUC) to detect 30% declines in coho salmon (Oncorhynchus kisutch) escapement over 10 years (i.e., the magnitude of trend that would warrant listing a coho population as threatened using the listing criteria of the Committee on the Status of Endangered Wildlife in Canada (COSEWIC)) given realistic levels of variability in these two factors. The mean count outperformed all other approaches across a wide range of scenarios about true population dynamics and survey designs, suggesting that a simple mean count method is suitable for monitoring coho escapements in relation to COSEWIC guidelines.

Detection of subbottom ice‐bonded permafrost on the Canadian Beaufort Shelf by ground electromagnetic measurements

Geophysics ◽  
1992 ◽  
Vol 57 (11) ◽  
pp. 1419-1427 ◽  
Author(s):  
G. J. Palacky ◽  
L. E. Stephens
Keyword(s):  
Field Experiments ◽  
Effective Means ◽  
Cost Effective ◽  
Bottom Layer ◽  
Accurate Estimate ◽  
The Arctic ◽  
Seismic Surveys ◽  
Reflection Seismic ◽  
Electromagnetic Measurements ◽  
Cost Effective Alternative

Accurate knowledge of the location of subbottom ice‐bonded permafrost is essential in planning major infrastructure projects such as pipelines in the Arctic. A combination of refraction and shallow reflection seismic surveys and drilling has been considered the most effective means of permafrost detection in offshore environments. Field experiments recently carried out on the Beaufort Shelf by the Geological Survey of Canada indicate that multifrequency horizontal‐loop electromagnetic (HLEM) measurements are a fast and cost‐effective alternative. During test surveys, 60 to 80 soundings were completed in a day. Analysis of HLEM field data shows that a four‐layer model is appropriate for the local geologic conditions. The first layer in the model, sea ice, is highly resistive (5000 Ω ⋅ m). The second layer consists of seawater and seawater‐saturated sediments (estimated resistivity 1 Ω ⋅ m). Because their true resistivities are not significantly different, it was not possible to separate the two highly conductive layers by inversion. The target of the survey, subbottom ice‐bonded permafrost, was the third layer in the section (resistivity 5000 Ω ⋅ m). The bottom layer is formed by unfrozen sediments (average resistivity 2 Ω ⋅ m). Comparison with seismic and drilling results indicates that detection of ice‐bonded permafrost by the HLEM method is reliable; the outlines of its upper boundary given by seismic and HLEM measurements are in good agreement. At the only borehole available, unconstrained inversion of HLEM data provided an accurate estimate of permafrost depth and thickness, but there is not enough drilling information to objectively assess the reliability of the technique.

scholarly journals Local food sales and point of sale priming: evidence from a supermarket field experiment

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ružica Brečić ◽  
Dubravka Sinčić Ćorić ◽  
Andrea Lučić ◽  
Matthew Gorton ◽  
Jelena Filipović
Keyword(s):  
Field Experiment ◽  
Field Experiments ◽  
Low Cost ◽  
Cost Effective ◽  
Economic Incentives ◽  
Local Foods ◽  
Content Type ◽  
Point Of Sale ◽  
Effective Manner ◽  
Responsible Consumption

Purpose An intention-behavior gap often occurs for socially responsible consumption, where despite positive consumer attitudes, sales remain disappointing. This paper aims to test the ability of in-store priming to increase sales of local foods vis-à-vis imported, cheaper equivalents. Design/methodology/approach Laboratory and field experiments in three countries (Croatia, Slovenia and Serbia), working with an international grocery retailer, assess the ability of textual and pictorial-based point of sale (PoS) materials to increase the purchase of local foods. Field sales data, for the purchase of local apples and cherries and their imported equivalents, are complemented by an analysis of loyalty card transactions. Findings Field data indicate that both pictorial and textual PoS materials, significantly increase the likelihood of purchasing local foods, against cheaper imported equivalents. Pictorial PoS materials appear more effective than textual equivalents. Laboratory study data indicate that PoS materials increase the salience of goal consistent mechanisms in decision-making at the expense of mechanisms to achieve non-primed goals. Research limitations/implications The field experiment lasted for only two weeks and focused on seasonal produce. Practical implications PoS materials offer a low cost intervention for modifying consumer behavior in stores. Originality/value The paper develops a theory regarding how priming works and its application in a supermarket setting. This is investigated and validated in the context of local foods. The study offers encouragement for the usefulness of other in-store primes, such as relating to diet, to improve socially desirable outcomes without economic incentives or coercion and in a cost-effective manner.

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.

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