Marginal analysis and cost effectiveness in seed orchard management

1987 ◽  
Vol 17 (6) ◽  
pp. 510-515 ◽  
Author(s):  
Thomas A. Thomson ◽  
Donald T. Lester ◽  
Jeanne A. Martin

We use marginal analysis for three seed orchard management decisions. First we consider the roguing of a seed orchard established with many untested trees. We show that inferior parents should be rogued to the point where the number of orchard trees times the average expected volume gain of trees from seed produced by that orchard is maximized. Marginal analysis also is useful where one must choose the number of trees to establish in an orchard planted after progeny tests have identified superior parents. The cost of establishing many ramets to meet early seed production goals can be balanced with the projected value of seed. For the example presented, an additional orchard tree is cost effective if its seed is needed at an orchard age of 12 to 15 years. Finally, we use marginal analysis to determine whether to induce a seed orchard to increase its seed production when there is an excess demand for seed. This decision is guided by balancing the cost of the induction treatment with the combined effect of expected increase in seed harvest, the amount of genetic gain, and the discount rate. We present a four-quadrant decision diagram for estimating this balance. In designing tree improvement programs, these analytical techniques can be applied to proposed alternatives as one way to structure decision making and to provide comparable economic assessments from which cost-effective choices can be made.

Author(s):  
Young-Jin Park ◽  
Frank F. Saccomanno

Various countermeasures can be introduced to reduce collisions at highway–railway grade crossings. Existing improvements to crossings include the installation of flashing lights or gates, the addition of extra warning devices such as four-quadrant barriers or wayside horns, and the enforcement of speed limits on the approaching highway. Statistical models are needed to ensure that countermeasures introduced at a given crossing are both cost-effective and practicable. However, in large part because of issues of colinearity, poor statistical significance, and parametric bias, many existing statistical models are simple in structure and feature few statistically significant explanatory variables. Accordingly, they fail to reflect the full gamut of factor inputs that explain variation in collision frequency at individual crossings over a given period of time. Before statistical models can be used to investigate the cost-effectiveness of specific countermeasures, models must be developed that more fully reflect the complex relationships that link a specific countermeasure to collision occurrence. This study presents a sequential modeling approach based on data mining and statistical methods to estimate the main and interactive effects of introducing countermeasures at individual grade crossings. This paper makes use of Canadian inventory and collision data to illustrate the potential merits of the model in decision support.


Author(s):  
Jan-Olof Löfdahl

This paper is a summary of 35 years experience from maintenance, overhaul and repair of the ROLLS-ROYCE Marine PROTEUS Gas Turbine in the Swedish Navy. The 54 installed PROTEUS Gas Turbines in 18 ships have accumulated nearly 300 000 running hours. The reliability has steadily improved thanks to careful monitoring and intensive improvement programs. The initial, less than 500 hours average between engine removals has been extended to nearly 3000 hours as of today. Also the number of catastrophic engine failures has decreased. Although the Spare Parts prices and the Labor Costs per hour have increased over the years the maintenance cost per fired Gas Turbine hour has decreased. The paper describes the technical and economical aspects together with the cost reducing efforts. The information derives from the Swedish Navy Maintenance and Failure Reporting System, named “MARIS”, and from the VOLVO overhaul workshop annual technical and economical activity report.


1996 ◽  
Vol 72 (5) ◽  
pp. 469-473 ◽  
Author(s):  
J. P. Barnett

Tree improvement programs have influenced significantly the quality of southern pine seeds produced when compared to collections from native stands. Seed orchard management practices such as fertilization can increase seed size and reduce seed dormancy. These result in the need for less complex pregermination treatments. Repeated cone collections from the same clones facilitate collections according to ripening (cone specific gravity), which can improve seed germination and storage. However, cultural practices may result in seed properties that are more sensitive to damage during processing procedures and result in lower quality unless special care is provided during this stage of handling. The effect of orchard management practices on seed quality also varies by species, with loblolly pine being less affected than longleaf pine. Key words: Pinus spp., seed germination, seed dormancy, seed storage, cone maturity


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1735-1735 ◽  
Author(s):  
Tom Kouroukis ◽  
Darrell White ◽  
Morgan Kruse ◽  
Donna Lawrence ◽  
Cristina Trambitas ◽  
...  

Abstract Introduction The effectiveness of bortezomib for induction treatment prior to ASCT in multiple myeloma (MM) patients has been demonstrated in a number of randomized, open-label phase III trials, including the IFM 2005-01 trial (Harousseau et al., J Clin Oncol 2010;28(30):4621-9). This trial showed that the addition of bortezomib as part of an induction treatment prior to ASCT resulted in statistically significant improvements in post-induction response rates and longer progression-free survival (PFS) compared to a non-bortezomib containing regimen (NBCR). The objective of this study was to assess the cost-utility of a bortezomib-containing regimen (BCR) vs. a NBCR for induction treatment in previously untreated MM patients prior to ASCT from a Canadian public payer perspective, based on the results of the IFM 2005-01 study. Methods A Markov model was developed to estimate the cost-utility over a lifetime horizon (50 years) in previously untreated MM patients undergoing induction and ASCT. The model simulated disease progression of patients with previously untreated MM through three health states: “progression-free”, “progression” and “death”, with all patients beginning in the progression-free state. The PFS and overall survival (OS) curves from the IFM 2005-01 trial were extrapolated beyond the study follow-up period to estimate the timeframe spent in each health state. Each health state was associated with a utility value and direct medical costs. Utilities for the progression-free and progression health states were derived from a previous cost-utility analysis for bortezomib and were 0.81 and 0.645, respectively (Hornberger et al., Eur J Haematol 2010;85(6):484-91). Transition probabilities between health states were estimated by calibrating the model to the PFS and OS curves from the IFM 2005-01 trial. In the base case, transition probabilities beyond the trial follow-up period were conservatively assumed to be equal for both treatment groups. Medical resource utilization was estimated using the IFM 2005-01 trial, and supplemented by published literature and clinical advisors. Clinical advisors also provided input on management of adverse events (> grade 3) and treatment of patients who progressed after induction and ASCT. Resource costs were estimated using Canadian sources ($CAN 2012) and costs and outcomes were discounted at 5% annually. Because patients in each group incurred similar costs (i.e. cost of an ASCT), only incremental costs between the two arms were included in the analysis. One-way sensitivity analyses and probabilistic sensitivity analyses were performed to test the robustness of the model. Results The mean total MM-related cost over the lifetime analysis in the model was $68,800 per patient treated with a BCR and $47,000 per patient treated with a NBCR. Addition of bortezomib to the induction regimen increased costs by $21,700 (see table). Over the model lifetime, a delay in progression with a BCR led to 0.25 years of additional survival compared to a NBCR and a quality-adjusted life-year (QALY) gain of 0.22 years. The incremental cost-utility ratio for induction using a BCR compared to a NBCR approach was $99,200/QALY. Sensitivity analyses identified the major factors impacting the cost-utility ratio as: transition probabilities beyond the trial follow-up period, discounting, utilities and bortezomib costs. The probability of a BCR being cost-effective compared to a NBCR was 43.9% at a threshold of $100,000/QALY. Conclusions A number of phase 3 trials have demonstrated the effectiveness of bortezomib as part of an induction regimen prior to ASCT. This analysis indicates that, from a Canadian perspective, induction treatment with a BCR in previously untreated MM patients prior to ASCT can be cost-effective at conventional decision thresholds with a cost-utility ratio of $99,200/QALY. Disclosures: Kouroukis: Janssen Inc.: Honoraria. White:Janssen Inc.: Consultancy, Honoraria. Kruse:OptumInsight: Employment. Lawrence:OptumInsight: Employment. Trambitas:Janssen Inc.: Employment.


1994 ◽  
Vol 18 (3) ◽  
pp. 122-127 ◽  
Author(s):  
Gregory L. Powell ◽  
Timothy L. White

Abstract The Cooperative Forest Genetics Research Program (CFGRP) initiated a slash pine (Pinus elliottii Engelm. var. elliottii) seed orchard management recording system (SOMRS) in 1985 to quantify cone and seed yields of slash pine orchards in the cooperative program. First, historical data were obtained from CFGRP slash pine seed orchards. Secondly, starting in 1985, cultural treatments and production yield data have been collected annually from 56 slash pine seed orchards located throughout Florida, Georgia, and Alabama. The vast majority of these orchards are intensively managed for seed production including the use of fertilizer, herbicide, and up to 10 applications of insecticide annually. From 1980 through 1990, the average seed yield from mature orchards (orchards greater than 14 yr old) was 25.1 bushels of cones, and 27.3 lb of seed/ac. For pounds per acre, orchards reach 50% and 90% of full production at ages 11 and 18 yr from grafting, respectively. The use of insecticides in slash pine seed orchards approximately doubles orchard yields. The CFGRP slash pine seed orchard management recording system (SOMRS) can aid orchard managers in determining factors that limit or promote seed production. South. J. Appl. For. 18(3):122-127.


2021 ◽  
Author(s):  
Heather A.M. Shepherd ◽  
Matt T. Trentman ◽  
Jennifer L. Tank ◽  
Jennifer Praner ◽  
Anissa Cervantes ◽  
...  

ABSTRACTPreventing eutrophication of inland freshwater ecosystems requires quantifying the phosphorous (P) content of the streams and rivers that feed them. Typical methods for measuring P assess soluble reactive P (SRP) or total P (TP) and require expensive analytical techniques that produce hazardous waste. Here we present a novel method for measuring the more relevant bioavailable P (BAP); this assay utilizes the growth of familiar baker’s yeast, avoids production of hazardous waste, and reduces cost relative to measurements of SRP and TP. The yeast BAP (yBAP) assay takes advantage of the observation that yeast density at saturating growth increases linearly with provided P. We show that this relationship can be used to measure P in freshwater in concentration ranges relevant to eutrophication. In addition, we measured yBAP in water containing known amount of fertilizer and in samples from agricultural waterways. We observed that the majority of yBAP values were between those obtained from standard SRP and TP measurements, demonstrating that the assay is compatible with real-world settings. The cost-effective and nonhazardous nature of the yeast-based assay suggests that it could have utility in a range of settings, offering added insight to identify water systems at risk of eutrophication from excess phosphorus.


2016 ◽  
Vol 25 (2) ◽  
pp. e063 ◽  
Author(s):  
J-Jesus Vargas-Hernandez ◽  
Jeniffer-Ivette Vargas-Abonce

Aim of study: Seed production in forest tree species commonly takes a long time due to the length of the juvenile stage. Even though several treatments have been used to induce early flowering in conifer species, experience on their use in subtropical Pinus species is limited. This study aimed to evaluate the effect of GA4/7 dose (0, 1.27 and 2.54 mg cm-2) and application time (July-October), alone or in combination with partial stem girdling, on male and female strobili production in young Pinus patula Schiede ex Schltdl. et Cham. clones.  Area of study: Nine clones with different flowering background of high-elevation Pinus patula growing in a six-year old seed orchard established in Central México (Aquixtla, Puebla) at 2,800 m elevation.Material and methods: Two independent flowering trials (FT1 and FT2) were carried out in the seed orchard during the 2009 and 2010 flowering cycles; similar factors were evaluated at both trials but time of application, clones tested, and experimental design used varied for each of them. Partial stem girdling was done at the base of the trunk and the GA4/7 solution was injected into the xylem above the point of girdling. The following spring, the percentage of trees with strobili and the number of strobili per tree were determined for both male and female structures.Main results: Significant differences (p ≤ 0.05) among clones in flowering capacity were found at both trials. None of the treatments applied in FT1 resulted in an increase of strobili formation, most probably because they were applied too late in the growing season. In FT2, however, application of GA4/7 combined with partial stem girdling increased the percentage of trees with strobili and the number of strobili of both sexes, particularly when applied in early July. Partial stem girdling was more effective on promoting male strobili than female ones in gibberellin-treated grafts.Research highlights: Timing of GA4/7 application and stem girdling was important, with a significant interaction with clones tested in FT2 on production of male strobili but not on female strobili. Application of 1.27 mg cm-2 GA4/7 and stem girdling in July promoted the highest percentage of trees with strobili, and increased 25-fold the number of female strobili and 5-fold the number of male strobili per tree as compared to the control treatment. Thus, operational use of this induction treatment would be valuable to increase and accelerate seed production in Pinus patula seed orchards in the region.Keywords: early flowering; gibberellins; juvenile stage; seed orchard; seed production.Abbreviations: GA: Gibberellic acid; GA4: Gibberellic acid 4; GA7: Gibberellic acid 7; GA4/7: Mix of gibberellic acids 4 and 7; FT1: Flowering trial carried out in the 2009 season; FT2: Flowering trial carried out in the 2010 season.


1996 ◽  
Vol 72 (5) ◽  
pp. 467-467 ◽  
Author(s):  
G.-É. Caron ◽  
R. Smith ◽  
D. Kolotelo

Author(s):  
James F. Mancuso

IBM PC compatible computers are widely used in microscopy for applications ranging from control to image acquisition and analysis. The choice of IBM-PC based systems over competing computer platforms can be based on technical merit alone or on a number of factors relating to economics, availability of peripherals, management dictum, or simple personal preference.IBM-PC got a strong “head start” by first dominating clerical, document processing and financial applications. The use of these computers spilled into the laboratory where the DOS based IBM-PC replaced mini-computers. Compared to minicomputer, the PC provided a more for cost-effective platform for applications in numerical analysis, engineering and design, instrument control, image acquisition and image processing. In addition, the sitewide use of a common PC platform could reduce the cost of training and support services relative to cases where many different computer platforms were used. This could be especially true for the microscopists who must use computers in both the laboratory and the office.


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