scholarly journals Optimizing Costs to Collect Local Infauna through Grabs: Effect of Sampling Size and Replication

Diversity ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 410
Author(s):  
Lidia N. Álvarez ◽  
Sara García-Sanz ◽  
Néstor E. Bosch ◽  
Rodrigo Riera ◽  
Fernando Tuya
Keyword(s):  
Sample Size ◽  
Cost Efficiency ◽  
Low Cost ◽  
Cost Benefit ◽  
Cost Effective ◽  
Wiener Index ◽  
Ecological Studies ◽  
Local Site ◽  
Optimal Sample ◽  
Size Accuracy

Most ecological studies require a cost-effective collection of multi-species samples. A literature review unravelled that (1) large-sized grabs to collect infauna have been used at greater depths, despite no consistent relationship between grab size and replication across studies; and (2) the total number of taxa and individuals is largely determined by the replication. Then, infauna from a sedimentary (sandy) seabed at Gran Canaria Island was collected through van Veen grabs of three sizes: 0.018, 0.042 and 0.087 m2 to optimize, on a simple cost-benefit basis, sample size and replication. Specifically, (1) the degree of representativeness in the composition of assemblages, and (2) accuracy of three univariate metrics (species richness, total infaunal abundances and the Shannon-Wiener index), was compared according to replication. Then, by considering mean times (a surrogate of costs) to process a sample by each grab, (3) their cost-efficiency was estimated. Representativeness increased with grab size. Irrespective of the grab size, accuracy of univariate metrics considerably increased when n > 10 replicates. Costs associated with the 0.087 m2 grab were consistently lower than costs by the other grabs. In conclusion, because of high representativeness and low cost, a 6.87 L grab appears to be the optimal sample size to assess infauna at our local site.

Optimal sample size for estimating the proportion of transgenic plants using the Dorfman model with a random confidence interval

2011 ◽  
Vol 21 (3) ◽  
pp. 235-245 ◽  
Author(s):  
Osval Antonio Montesinos-López ◽  
Abelardo Montesinos-López ◽  
José Crossa ◽  
Kent Eskridge ◽  
Ricardo A. Sáenz
Keyword(s):  
Transgenic Plants ◽  
Confidence Interval ◽  
Sample Size ◽  
Low Cost ◽  
Group Testing ◽  
Simulated Data ◽  
R Program ◽  
Optimal Sample ◽  
The Monte Carlo Method ◽  
Adventitious Presence

AbstractGroup testing is a procedure in which groups that contain several units (plants) are analysed without having to inspect individual plants, with the purpose of estimating the prevalence of genetically modified plants (adventitious presence of unwanted transgenic plants, AP) in a population at a low cost, without losing precision. When pool (group) testing is used to estimate the proportion of AP (p), there are several procedures that can be used for computing the confidence interval (CI); however, they usually do not ensure precision in the estimation of p. This research proposes a formula for determining the required number of pools (g), given a pool size (k), for estimating the proportion of AP plants using the Dorfman model. The proposed formula ensures precision in the estimated proportion of AP because it guarantees that the width (W) of the CI will be equal to, or narrower than, the desired width (ω), with a probability of γ. This probability accounts for the stochastic nature of the sample variance of p. We give examples to show how to use the proposed sample-size formula. Simulated data were created and tables are presented showing the different scenarios that a researcher may encounter. The Monte Carlo method was used to study the coverage and the level of assurance achieved by the proposed sample sizes. An R program that reproduces the results in the tables and makes it easy for the researcher to create other scenarios is given in the Appendix.

scholarly journals 3D Printing of Rapid, Low-Cost and Patient-Specific Models of Brain Vasculature for Use in Preoperative Planning in Clipping of Intracranial Aneurysms

2021 ◽  
Vol 10 (6) ◽  
pp. 1201
Author(s):  
Maciej Błaszczyk ◽  
Redwan Jabbar ◽  
Bartosz Szmyd ◽  
Maciej Radek
Keyword(s):  
3D Visualization ◽  
Low Cost ◽  
Cost Benefit ◽  
Image Data ◽  
Cost Effective ◽  
3D Models ◽  
Urgent Care ◽  
Patient Specific ◽  
Stl File ◽  
3D Printed

We developed a practical and cost-effective method of production of a 3D-printed model of the arterial Circle of Willis of patients treated because of an intracranial aneurysm. We present and explain the steps necessary to produce a 3D model from medical image data, and express the significant value such models have in patient-specific pre-operative planning as well as education. A Digital Imaging and Communications in Medicine (DICOM) viewer is used to create 3D visualization from a patient’s Computed Tomography Angiography (CTA) images. After generating the reconstruction, we manually remove the anatomical components that we wish to exclude from the print by utilizing tools provided with the imaging software. We then export this 3D reconstructions file into a Standard Triangulation Language (STL) file which is then run through a “Slicer” software to generate a G-code file for the printer. After the print is complete, the supports created during the printing process are removed manually. The 3D-printed models we created were of good accuracy and scale. The median production time used for the models described in this manuscript was 4.4 h (range: 3.9–4.5 h). Models were evaluated by neurosurgical teams at local hospital for quality and practicality for use in urgent and non-urgent care. We hope we have provided readers adequate insight into the equipment and software they would require to quickly produce their own accurate and cost-effective 3D models from CT angiography images. It has become quite clear to us that the cost-benefit ratio in the production of such a simplified model is worthwhile.

scholarly journals Curating Local Knowledge: Experimental Evidence from Small Retailers in Indonesia

2021 ◽  
Author(s):  
Patricio S Dalton ◽  
Julius Rüschenpöhler ◽  
Burak Uras ◽  
Bilal Zia
Keyword(s):  
Cost Benefit Analysis ◽  
Low Cost ◽  
Cost Benefit ◽  
Cost Effective ◽  
Business Practices ◽  
Performance Improvements ◽  
Effective Manner ◽  
Behavioral Constraints ◽  
And Performance ◽  
Outstanding Question

Abstract Business practices and performance vary widely across businesses within the same sector. A key outstanding question is why profitable practices do not readily diffuse. We conduct a field experiment among urban retailers in Indonesia to study whether alleviating informational and behavioral frictions can facilitate such diffusion in a cost-effective manner. Through quantitative and qualitative fieldwork, we curate a handbook that associates locally relevant practices with performance, and provides idiosyncratic implementation guidance informed by exemplary local retailers. We complement this handbook with two light-touch interventions to facilitate behavior change. A subset of retailers is invited to a documentary movie screening featuring the paths to success of exemplary peers. Another subset is offered two 30 minute personal visits by a local facilitator. A third group is offered both. Eighteen months later, we find significant impacts on practice adoption when the handbook is coupled with the two behavioral nudges, and up to a 35% increase in profits and 16.7% increase in sales. These findings suggest both informational and behavioral constraints are at play. The types of practices adopted map the performance improvements to efficiency gains rather than other channels. A simple cost-benefit analysis shows such locally relevant knowledge can be codified and scaled successfully at relatively low cost.

scholarly journals Cost comparison of different treatment approaches of dacryocystitis and dacrocystocele

2020 ◽  
Vol 12 ◽  
pp. 251584142092628
Author(s):  
Erin G. Sieck ◽  
Leonid Zukin ◽  
Jennifer L. Patnaik ◽  
Anne M. Lynch ◽  
Peggy Kelley ◽  
...  
Keyword(s):  
Chart Review ◽  
Low Cost ◽  
Operating Time ◽  
Cost Benefit ◽  
Retrospective Chart Review ◽  
Cost Effective ◽  
Nasolacrimal Duct ◽  
Cost Comparison ◽  
Nasal Endoscopy ◽  
Surgical Approaches

Purpose: Congenital dacrocystocele with potential for dacryocystitis are common ophthalmic findings in children. There are multiple surgical approaches to open the mucocele. In this study, we look at the financial impact of these different approaches. Methods: A retrospective chart review of 17 patients with dacrocystocele or dacryocystitis was performed. We examined four approaches: (1) bedside nasal endoscopy with marsupialization of nasolacrimal duct (NLD) cyst, (2) surgically performed nasal endoscopy with marsupialization of NLD cyst, (3) NLD probe, and (4) a combination of procedures. Cost of the procedure and length of anesthesia were collected. Reoccurrence of symptoms and disease post-procedure were also collected. Results: The lowest cost billed procedure was bedside nasal endoscopy performed by an otolaryngologist (US$435; n = 1). A nasal endoscopy ( n = 2) performed in the operating room (OR) had an average OR fee of US$14,557 [standard deviation (SD): US$7598] for 108.5 (SD: 87.0) min of operating time. An NLD probe ( n = 5) performed by pediatric ophthalmologists resulted in an average OR fee of US$5540 (SD: US$1752) for 31.0 min (SD: 8.6 min) of operating time. A combination of both nasal endoscopy and NLD probing ( n = 9) had an average OR fee US$10,325 (SD: US$4137) for 69 min (SD: 34.5 min) of operating time. Conclusion: This is the first study looking at cost benefit of four different approaches to treating dacrocystoceles/dacryocystitis. A NLD probe was a low-cost OR intervention and had the shortest operating time. The combination procedure was more cost-effective than nasal endoscopy or NLD probing alone.

Value of Information and Hypothesis Testing Approaches for Sample Size Determination in Engineering Component Inspection: A Comparison

2016 ◽  
Author(s):  
Eishiro Higo ◽  
Mahesh D. Pandey
Keyword(s):  
Sample Size ◽  
Value Of Information ◽  
Nuclear Power ◽  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
Sample Size Determination ◽  
Size Determination ◽  
Benefit Analysis ◽  
Current State ◽  
Optimal Sample

A sample size determination method is developed for a two-action problem that represents a component maintenance scenario requiring current state estimation. For safety and generation efficiency, each component of a nuclear power plant must be regularly inspected. In terms of safety, the larger the sample size inspected, the less the uncertainty about current and future states of the components; however, such inspections are expensive. Thus, sample size determination becomes an important problem. A key idea for solving this problem is the Value of Information (VoI) and its derivation: the Expected Net Gain of Sampling (ENGS). The ENGS is a function of sample size and represents by how much a decision maker benefits from the observed data. By maximizing the ENGS, the optimal sample size is determined in terms of cost-benefit analysis.

scholarly journals The High Cost of the Low-Cost Polybag System: A Review of Nursery Seedling Production Systems

Land ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 826
Author(s):  
Diane Haase ◽  
Karma Bouzza ◽  
Lucy Emerton ◽  
James Friday ◽  
Becca Lieberg ◽  
...  
Keyword(s):  
Production Systems ◽  
Low Cost ◽  
Field Performance ◽  
Cost Benefit ◽  
Holistic Approach ◽  
Cost Effective ◽  
Cultural Elements ◽  
Advantages And Disadvantages ◽  
Nursery Production ◽  
Survival And Growth

An important strategy for meeting global landscape restoration goals is nursery production of high-quality seedlings. Growing seedlings with attributes that promote post-planting survival and growth can be dramatically influenced by the nursery container system. In many countries, nurseries produce seedlings in polybags filled with excavated soil. These seedlings often develop deformed roots with limited fibrosity which can lead to poor survival and growth after outplanting. Polybags are initially inexpensive but using these single-use plastic containers accrues expenses that are often untracked. Comparisons among nursery production systems must account for factors such as container longevity, labor efficiency, and seedling field performance. A more holistic approach to account for environmental, economic, social, logistic, and cultural elements in the cost–benefit equation that influences nursery production systems is needed. Converting to a modern container system requires concomitant adjustments in nursery scheduling and culturing matched to the new stock type. Doing so provides an opportunity to align nursery production techniques and resulting seedling attributes with anticipated field conditions. This article describes and discusses the advantages and disadvantages of nursery production systems and provides recommendations and case studies to aid nurseries in improving seedling quality toward meeting restoration goals in a cost-effective and timely manner.

ASSESSMENT OF THE PLATELET COUNT IN THE PREGNANT WOMEN IN IGIMS, PATNA, BIHAR

2020 ◽  
Vol 4 (2) ◽  
Author(s):  
Tanwi Singh ◽  
Anshuman Sinha
Keyword(s):  
Platelet Count ◽  
Pregnant Women ◽  
Screening Test ◽  
Low Cost ◽  
Medical Science ◽  
Cost Effective ◽  
Platelet Indices ◽  
Increased Risk ◽  
Low Platelet Count ◽  
Severity Of The Disease

The major risk associated with low platelet count in pregnancy is the increased risk of bleeding during the childbirth or post that. There is an increased blood supply to the uterus during pregnancy and the surgical procedure requires cutting of major blood vessels. Women with thrombocytopenia are at increased risk of losing excessive blood. The risk is more in case of caesarean delivery as compared to vaginal delivery. Hence based on above findings the present study was planned for Assessment of the Platelet Count in the Pregnant Women in IGIMS, Patna, Bihar. The present study was planned in Department of Pathology, Indira Gandhi Institute of Medical Science, Patna, Bihar, India. The present study was planned from duration of January 2019 to June 2019. In the present study 200 pregnant females samples received for the platelet estimation were enrolled in the present study. Clinically platelet indices can be a useful screening test for early identification of preeclampsia and eclampsia. Also platelet indices can assess the prognosis of this disease in pregnant women and can be used as an effective prognostic marker because it correlates with severity of the disease. Platelet count is a simple, low cost, and rapid routine screening test. Hence the data generated from the present study concludes that platelet count can be used as a simple and cost effective tool to monitor the progression of preeclampsia, thereby preventing complications to develop during the gestational period. Keywords: Platelet Count, Pregnant Women, IGIMS, Patna, Bihar, etc.

Janus – A New Approach to Air Combat Pilot Training

2019 ◽  
Vol 2019 (4) ◽  
pp. 7-22
Author(s):  
Georges Bridel ◽  
Zdobyslaw Goraj ◽  
Lukasz Kiszkowiak ◽  
Jean-Georges Brévot ◽  
Jean-Pierre Devaux ◽  
...  
Keyword(s):  
Low Cost ◽  
Cost Effective ◽  
High Energy ◽  
Training System ◽  
Embedded Sensors ◽  
Pilot Training ◽  
New Approach ◽  
Combat Aircraft ◽  
Air Combat ◽  
The Cost

Abstract Advanced jet training still relies on old concepts and solutions that are no longer efficient when considering the current and forthcoming changes in air combat. The cost of those old solutions to develop and maintain combat pilot skills are important, adding even more constraints to the training limitations. The requirement of having a trainer aircraft able to perform also light combat aircraft operational mission is adding unnecessary complexity and cost without any real operational advantages to air combat mission training. Thanks to emerging technologies, the JANUS project will study the feasibility of a brand-new concept of agile manoeuvrable training aircraft and an integrated training system, able to provide a live, virtual and constructive environment. The JANUS concept is based on a lightweight, low-cost, high energy aircraft associated to a ground based Integrated Training System providing simulated and emulated signals, simulated and real opponents, combined with real-time feedback on pilot’s physiological characteristics: traditionally embedded sensors are replaced with emulated signals, simulated opponents are proposed to the pilot, enabling out of sight engagement. JANUS is also providing new cost effective and more realistic solutions for “Red air aircraft” missions, organised in so-called “Aggressor Squadrons”.

Cost-effective upgrading of the Arnsberg WWTP by post denitrification with a moving bed system

2000 ◽  
Vol 41 (9) ◽  
pp. 123-130
Author(s):  
N. Jardin ◽  
L. Rath ◽  
A. Sabin ◽  
F. Schmitt ◽  
D. Thöle ◽  
...  
Keyword(s):  
Carbon Source ◽  
Biological Process ◽  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
Cost Effective ◽  
Benefit Analysis ◽  
Moving Bed ◽  
Trickling Filters ◽  
Sludge Hydrolysis ◽  
Effective Integration

On the basis of a cost-benefit analysis it was decided to expand the Arnsberg WWTP by a multistage biological process which allows for cost-effective integration of the existing facilities. Carbon removal will then be accomplished in a high-loaded activated sludge stage for which the existing primary clarifier is to be reconstructed. The existing trickling filters will be used for nitrification during a midterm period and will be replaced later on either by a moving bed system or by new trickling filters. Line 3 of the existing secondary clarifiers will be reconstructed and used for post denitrification in a moving bed system. The carbon needed for denitrification will be provided by means of sludge hydrolysis and the use of an external carbon source.

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