COCCINELLIDS (COLEOPTERA: COCCINELLIDAE) AND SYRPHIDS (DIPTERA: SYRPHIDAE) AS PREDATORS OF APHIDS IN CEREAL CROPS: A COMPARISON OF SAMPLING METHODS

1987 ◽  
Vol 119 (9) ◽  
pp. 815-822 ◽  
Author(s):  
L. Lapchin ◽  
A. Ferran ◽  
G. Iperti ◽  
J.M. Rabasse ◽  
J.P. Lyon
Keyword(s):  
Large Scale ◽  
Sampling Method ◽  
Sampling Methods ◽  
Cereal Crops ◽  
Predator Density ◽  
Wheat Field ◽  
Searching Method ◽  
Plant Sampling ◽  
Syrphid Larvae ◽  
Full Height

AbstractThe reliability of three methods for sampling aphidophagous coccinellids and syrphids in a winter wheat field was compared.In the first method, an observer recorded predators seen during 2 min per 25-m2 sub-plot. In the second, two observers worked successively through each plot, scanning the full height of wheat plants and collecting predators. This method enables calculation of predator density using De Lury’s technique. The third method consisted of collecting wheat plants from each sub-plot for examination in the laboratory.The first method may be used for appraising populations of adult coccinellids on a large scale. The detailed searching method is appropriate for studies of the population dynamics of adult and fourth-instar coccinellids. The plant sampling method is the most accurate for assesssing densities of syrphid larvae and pupae.

Comparison of Two Soil Sampling Methods for Estimating Population Densities of Heterodera glycines Cysts

2016 ◽  
Vol 17 (3) ◽  
pp. 167-171 ◽  
Author(s):  
Ethan Smrtnik ◽  
Terry Niblack ◽  
Pierce Paul ◽  
Anne Dorrance ◽  
Dain Bruns
Keyword(s):  
Soybean Cyst Nematode ◽  
Large Scale ◽  
Sampling Method ◽  
Sampling Methods ◽  
Management Program ◽  
Soil Sampling ◽  
Population Densities ◽  
Added Benefit ◽  
Automation Technology ◽  
Economic Pest

Soybean cyst nematode (SCN) is a significant economic pest of soybean in Ohio and the Midwest, in which yield losses are directly linked to the population density and distribution of cysts within a field. Advances in automation technology have been used to expedite soil fertility sampling for large-scale and high-density field maps. In this study, we explored the use of this technology as an option for sampling for SCN. There was a significant positive correlation for the number of SCN cysts between soil samples collected with an Automated Precision Soil Sampler and those collected using the traditional soil sampling method from three separate fields (P < 0.05, r values of 0.79 to 0.93). These results suggest that expedited soil sampling in fields with high population densities could be an added benefit for soybean farmers to encourage more sampling for SCN to monitor population levels as part of their overall management program. Accepted for publication 18 July 2016. Published 12 August 2016.

The estimation of yield in cereal crops by sampling methods

1929 ◽  
Vol 19 (2) ◽  
pp. 214-235 ◽  
Author(s):  
A. R. Clapham
Keyword(s):  
Statistical Theory ◽  
Random Sampling ◽  
Sampling Method ◽  
Sampling Methods ◽  
Total Variance ◽  
Cereal Crops ◽  
Sampling Errors ◽  
Random Location

1. Cereal plots were sampled by three different methods; two systematic, and one involving a random location of sampling units.2. The disadvantages of the systematic methods as compared with random sampling, emerged clearly.3. These disadvantages were further emphasised in an analysis of earlier data on sampling methods. For this purpose the methods and. results of certain recent contributions to statistical theory were used.4. By the use of a random sampling method, the variance due to sampling errors may be made a satisfactorily small fraction of the total variance of cereal plots one-fortieth of an acre in area.

Invasive Cereal Aphids of North America: Ecology and Pest Management

2019 ◽  
Vol 64 (1) ◽  
pp. 73-93 ◽  
Author(s):  
Michael J. Brewer ◽  
Frank B. Peairs ◽  
Norman C. Elliott
Keyword(s):  
North America ◽  
Pest Management ◽  
Great Plains ◽  
Large Scale ◽  
Production Systems ◽  
Cereal Crops ◽  
Cereal Aphids ◽  
Sugarcane Aphid ◽  
Cereal Production ◽  
Abundance And Diversity

Aphid invasions of North American cereal crops generally have started with colonization of a new region or crop, followed by range expansion and outbreaks that vary in frequency and scale owing to geographically variable influences. To improve understanding of this process and management, we compare the invasion ecology of and management response to three cereal aphids: sugarcane aphid, Russian wheat aphid, and greenbug. The region exploited is determined primarily by climate and host plant availability. Once an area is permanently or annually colonized, outbreak intensity is also affected by natural enemies and managed inputs, such as aphid-resistant cultivars and insecticides. Over time, increases in natural enemy abundance and diversity, improved compatibility among management tactics, and limited threshold-based insecticide use have likely increased resilience of aphid regulation. Application of pest management foundational practices followed by a focus on compatible strategies are relevant worldwide. Area-wide pest management is most appropriate to large-scale cereal production systems, as exemplified in the Great Plains of North America.

The Estimation of the Efficiency of Sampling, with Special Reference to Sampling for Yield in Cereal Experiments

1935 ◽  
Vol 25 (4) ◽  
pp. 545-577 ◽  
Author(s):  
F. Yates ◽  
I. Zacopanay
Keyword(s):  
Standard Deviation ◽  
Special Reference ◽  
Analysis Of Variance ◽  
Sampling Methods ◽  
Cereal Crops ◽  
Loss Of Information ◽  
Preliminary Discussion ◽  
Experimental Errors ◽  
Series Of Experiments ◽  
The Mean

The estimation of the experimental yields of cereal crops by sampling methods is considered in the light of results of eighteen experiments which were harvested by these methods at Rothamsted and its associated centres. The harvesting results of the Crop-Weather series of experiments are also included.A preliminary discussion of the interpretation of the analysis of variance as applied to sampling results is given, and an expression is found for the loss of information arising out of sampling. The results of the discussion are applicable to all types of sampling carried out on replicated experiments.The sampling and experimental errors of all the experiments have been calculated. The variation between sampling units in the same subplot (usually between l/100th and l/200th acre) was found to be such as would arise if each metre length of row had a standard deviation (about the plot mean) of the order of 25–30 per cent. of the mean yield.

scholarly journals Reference genome assemblies reveal the origin and evolution of allohexaploid oat

2021 ◽  
Author(s):  
Yuanying Peng ◽  
Honghai Yan ◽  
Laichun Guo ◽  
Cao Deng ◽  
Lipeng Kang ◽  
...  
Keyword(s):  
Large Scale ◽  
Molecular Mechanisms ◽  
Higher Plants ◽  
Cereal Crops ◽  
Origin And Evolution ◽  
Avena Species ◽  
Oxford Nanopore ◽  
Reference Quality ◽  
Phylogenomic Analyses ◽  
Reference Genomes

Abstract Common oat (Avena sativa) is one of the most important cereal crops serving as a valuable source of forage and human food. While reference genomes of many important crops have been generated, such work in oat has lagged behind, primarily owing to its large, repeat-rich, polyploid genome. By using Oxford Nanopore ultralong sequencing and Hi-C technologies, we have generated the first reference-quality genome assembly of hulless common oat with a contig N50 of 93 Mb. We also assembled the genomes of diploid and tetraploid Avena ancestors, which enabled us to identify oat subgenome, large-scale structural rearrangements, and preferential gene loss in the C subgenome after hexaploidization. Phylogenomic analyses of cereal crops indicated that the oat lineage descended before wheat, offering oat as a unique window into the early evolution of polyploid plants. The origin and evolution of hexaploid oat is deduced from whole-genome sequencing, plastid genome and transcriptomes assemblies of numerous Avena species. The high-quality reference genomes of Avena species with different ploidies and the studies of their polyploidization history will facilitate the full use of crop gene resources and provide a reference for the molecular mechanisms underlying the polyploidization of higher plants, helping us to overcome food security challenges.

Non-Probabilistic Sampling in Quantitative Clinical Research

2022 ◽  
Vol 7 (1) ◽  
pp. 0-0
Keyword(s):  
Best Practices ◽  
Quantitative Research ◽  
Sampling Method ◽  
Sampling Methods ◽  
Early Career ◽  
Probability Sampling ◽  
Probabilistic Sampling ◽  
Quantitative Studies ◽  
Health Studies ◽  
Probabilistic Sample

Quantitative researchers need a probabilistic sample to generalise their findings, but research constraints often compel them to use non-probabilistic samples. The use of non-probability sampling methods in quantitative studies has therefore become a norm. Interestingly, even studies published in top-quality journals compromise best practices that the use of non-probabilistic samples requires. Based on a thorough review of relevant studies, we developed a typology of non-probability sampling methods used in quantitative health studies. An attempt was made to discuss the limit of inference under each type of non-probability sampling method. Non-probability sampling in quantitative research was also delineated as a way to maximise response rate. This study is expected to guide students and early career epidemiologists to understand how to apply non-probabilistic sampling methods in quantitative approaches and plausibly document or report their chosen methods.

Digital instruments for reporting of gastrointestinal symptoms in clinical trials: comparison of end-of-day diaries versus experience sampling method (Preprint)

2021 ◽  
Author(s):  
Abraham B. Beckers ◽  
Johanna T.W. Snijkers ◽  
Zsa Zsa R.M. Weerts ◽  
Lisa Vork ◽  
Tim Klaassen ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Randomized Controlled Trial ◽  
Irritable Bowel Syndrome ◽  
Sampling Method ◽  
Sampling Methods ◽  
Controlled Trial ◽  
Smartphone Application ◽  
Randomized Controlled ◽  
Pre Treatment ◽  
Irritable Bowel

BACKGROUND Questionnaires are necessary tools for assessing symptoms of disorders of the brain-gut interaction in clinical trials. We previously reported on the excellent compliance to a smartphone app used as symptom diary in a randomized clinical trial in irritable bowel syndrome (IBS). Other sampling methods, such as the experience sampling method (ESM), are better equipped to measure symptom variability over time, provide useful information regarding possible symptom triggers and are free of ecological and recall bias. The high frequency of measurements, however, could limit the feasibility of ESM in clinical trials. OBJECTIVE This study aimed to compare compliance rates of a smartphone-based end-of-day diary and ESM for symptom assessment in irritable bowel syndrome and functional dyspepsia (FD). METHODS Data from four studies were included. Patients with IBS participated in a randomized controlled trial, which involved a smartphone end-of-day diary of 2+8 weeks (pre-treatment + treatment period), and an observational study, during which patients completed ESM assessments using a smartphone application for one week. Patients with FD participated in a randomized controlled trial, which involved a smartphone end-of-day diary of 2+12 weeks (pre-treatment + treatment period), and an observational study, during which patients completed ESM assessments using a smartphone application for one week. Compliance rates were compared between these two symptom sampling methods. RESULTS Twenty-five patients with IBS and fifteen patients with FD were included. Overall compliance rates for the end-of-day diaries were significantly higher than for ESM (IBS: 92.7% versus 69.8%, FD: 90.1% versus 61.4%, respectively). CONCLUSIONS We here demonstrate excellent compliance rates for smartphone application-based end-of-day diaries as used in two separate clinical trials. Overall compliance rates for ESM were significantly lower, rendering it more suitable for intermittent sampling periods rather than continuously during longer clinical trials.

Sukuk as an Infrastructure-Financing Tool

2020 ◽  
pp. 770-787
Author(s):  
Ahliddin Malikov
Keyword(s):  
Developing Countries ◽  
Data Analysis ◽  
Large Scale ◽  
Qualitative Data ◽  
Sampling Method ◽  
Islamic Finance ◽  
Infrastructure Projects ◽  
Potential Benefits ◽  
Potential Risks ◽  
Depth Interviews

Although many studies have stressed potential benefits of using Sukuk for funding large-scale infrastructure projects, several technical, legal, and political obstacles that are encountered by new sovereign and corporate issuers, investors, and Shari'ah boards remain largely unexplored. This research evaluates the opportunities, barriers, and potential risks for future Sukuk issuances that are proposed for funding large-scale infrastructure projects in developing countries. A purposive sampling method was employed to conduct in-depth interviews with several Islamic finance experts in support of the qualitative data analysis. Using the maximal variation and snowball approach, the researcher identifies the key challenges for large-scale Sukuk issuances and provides useful interpretations that can contribute to the expansion of Sukuk structures for a wider international investor base.

Sampling Methods and Frozen Storage of Samples for Detection of Campylobacter jejuni on Freshly Processed Broiler Carcasses

1983 ◽  
Vol 46 (6) ◽  
pp. 510-513 ◽  
Author(s):  
L. C. BLANKENSHIP ◽  
S. E. CRAVEN ◽  
J. Y. CHIU ◽  
G. W. KRUMM
Keyword(s):  
Campylobacter Jejuni ◽  
Sampling Method ◽  
Sampling Methods ◽  
Frozen Storage ◽  
Test Tube ◽  
Tissue Samples ◽  
Defibrinated Sheep Blood ◽  
Cryoprotective Agents ◽  
Plastic Bags ◽  
Sampling Locations

Swab, rinse and excision sampling methods are commonly used for detection of microorganisms on poultry carcasses. Swabbing has been the most frequently reported sampling method for Campylobacter jejuni on poultry. We evaluated the three methods for C. jejuni detection on freshly processed poultry in the following ways: (a) the interior and exterior surfaces of half of a carcass were each thoroughly rubbed with separate swabs which were combined in a test tube containing 2 ml of appropriate medium; (b) 25 g of skin and tissue samples from neck and abdominal opening cut areas were deposited in a stomacher bag with 5 ml of brucella broth (BB) and stomached for 2 min; and (c) half carcasses were shaken for 1 min with 100 ml BB in plastic bags. One drop of each sample was streaked for isolation on brucella agar containing 10% defibrinated sheep blood and Skirrow antibiotics. Isolates were identified by microscopy and appropriate cultural tests. All three sampling techniques were essentially equivalent for detection of C. jejuni on fresh carcasses. However, when samples were stored frozen for 7 to 10 d to simulate transport conditions from sampling locations to the laboratory, the incidence of detection was significantly reduced. Use of cryoprotective agents was an effective method to preserve swab samples during frozen storage.

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