Single- and multiple-trait index selection efficiencies in Fraser fir Christmas trees

1994 ◽  
Vol 24 (7) ◽  
pp. 1487-1494 ◽  
Author(s):  
R.J. Arnold ◽  
F.E. Bridgwater ◽  
J.B. Jett

Selection methods for Abiesfraseri (Pursh) Poir. for Christmas tree wholesale value were evaluated based on parameters from the species' first genetic field test. For single-trait individual selection, combined individual plus family selection at half rotation age (4 years) on total height (HT4) gave the greatest estimated full rotation (8-year) retail value (VALUE) gain of 24.3%. The best 8-year trait, crown diameter, resulted in a gain of only 22.4%. Incorporation of family mean information together with individual values in the selection process was important in maximizing gains. Only 8-year stem straightness (STR8) had unfavorable genetic and phenotypic correlations with other traits. With multitrait combined optimum index selection, use of Kempthorne restrictions to prevent adverse change in this trait seriously limited gains in other 8-year traits. Severity of this limitation increased for younger age indices, and for those with fewer traits. Unrestricted combined optimum indices offered substantial VALUE gain advantages and only small decreases in STR8. Initial selection among seed sources also increased VALUE gain, despite decreasing the effective additive genetic variation. VALUE gains through initial source selection exceeded gain reductions from the genetic variation decreases. The optimum selection strategy, with 30.5% VALUE gain, involved initial source selection followed by unrestricted combined optimum index selection on HT4, and 4-year density. Though slightly below the maximum, this strategy would provide substantial economic and technical advantage in conducting field tests.

2013 ◽  
Vol 368 (1628) ◽  
pp. 20130056 ◽  
Author(s):  
Matteo Toscani ◽  
Matteo Valsecchi ◽  
Karl R. Gegenfurtner

When judging the lightness of objects, the visual system has to take into account many factors such as shading, scene geometry, occlusions or transparency. The problem then is to estimate global lightness based on a number of local samples that differ in luminance. Here, we show that eye fixations play a prominent role in this selection process. We explored a special case of transparency for which the visual system separates surface reflectance from interfering conditions to generate a layered image representation. Eye movements were recorded while the observers matched the lightness of the layered stimulus. We found that observers did focus their fixations on the target layer, and this sampling strategy affected their lightness perception. The effect of image segmentation on perceived lightness was highly correlated with the fixation strategy and was strongly affected when we manipulated it using a gaze-contingent display. Finally, we disrupted the segmentation process showing that it causally drives the selection strategy. Selection through eye fixations can so serve as a simple heuristic to estimate the target reflectance.


FLORESTA ◽  
1999 ◽  
Vol 29 (12) ◽  
Author(s):  
SIMONE APARECIDA DE OLIVEIRA ◽  
MARIO LUIZ TEIXEIRA DE MORAES ◽  
SALATIÉR BUZETTI

Sementes de aroeira foram obtidas a partir de 30 árvores de polinização livre, localizadas na Estação Ecológica do Instituto Florestal em Paulo de Faria - SP, em setembro de 1996. Foram instalados dois testes de progênies de aroeira (consorciado com mutambo e angico do campo – Exp 1 e homogêneo – Exp 2), em março de 1997, na Fazenda de Ensino e Pesquisa da FEIS/UNESP, em Selvíria - MS. O delineamento experimental utilizado foram os blocos casualizados, tanto no experimento consorciado como no homogêneo. Os caracteres nutricionais avaliados foram o conteúdo de: N, P, K, Ca, Mg e S. As estimativas de parâmetros genéticos foram obtidas em nível de média de parcelas. A herdabilidade, aos dois anos, variou de 0,05 (para o Mg) a 0,63 (para o N). Foi encontrada variabilidade genética para o teor de nutrientes e a característica mais indicada para um processo de seleção seria o conteúdo de N. Nutrient aspects of genetic variation on progeny of Myracrodruon urundeuva Fr. All. under different condition of crop Abstract Aroeira seeds were obtained from 30 trees of open pollination, located in the Estação Ecológica do Instituto Florestal in Paulo de Faria – SP, in September, 1996. Two tests of Aroeira progeny were conducted (mutambo and angico together – Exp 1 and homogeneous – Exp 2), in March, 1997, at experimental station of FEIS/UNESP, in Selvíria – MS. A randomized completely block design, to both experiments was used. The nutrient content evaluated was: N, P, K, Ca, Mg, and S. The genetic estimates achieved to mean plot level and herdability on 2 year old trees was 0,05 to Mg and 0,63 to N. There was genetic variability to nutrient content and N was the better characteristic to selection process.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Liqiang Qiao

To cope with an exponentially increasing demand on mobile data traffic in cellular network, proximity-based opportunistic vehicular communications can be exploited as a complementary mean to offload and reduce the load of cellular network. In this paper, we propose a two-phase approach for mobile data traffic offloading, which exploits opportunistic contact and future utility with user mobility. The proposed approach includes one phase of initial source selection and subsequent phase of data forwarding. In phase 1, we build a weighted reachability graph, which is a very useful high-level abstraction for studying vehicular communication over time. Then, we propose an initial source selection algorithm, named VRank, and apply it in the weight reachability graph to identify some influential vehicles to serve as initial sources according to the rank of VRank. In phase 2, we formulate the forwarding schedule problem as a global utility maximization problem, which takes heterogeneous user interest and future utility contribution into consideration. Then, we propose an efficient scheme MGUP to solve the problem by providing a solution that decides which object should be broadcast. The effectiveness of our algorithm is verified through extensive simulation using real vehicular trace.


2020 ◽  
Vol 21 (1) ◽  
pp. 39-47
Author(s):  
Emiliana Sri Pudjiarti ◽  
Prihatin Tiyanto Priagung Hutomo

In relation to the problem of SME productivity, it is necessary to investigate whether there is a problem of mismatch between workers and work and groups and corporate cultural values. This study aims to analyze whether the concept of innovative work behavior can mediate the relationship of person-job fit, person-organization fit and person-group fit to job performance. The study was conducted in the metal SME industry in Tegal Regency, with 256 respondents. Data collection tools use questionnaires and interviews. Data analysis is done with a structural equation model. Based on the results of the analysis, there is a positive relationship between variables. This illustrates that the challenges of SMEs in the future are to maintain the best human resources to remain committed to the organization. In maintaining its existence, alignment of individual values with work, organization and groups is the best tool to achieve goals through innovative changes in employee behavior, and also to lay a solid foundation in the recruitment and selection process of new employees that have the potential to increase job performance.


2015 ◽  
Author(s):  
Jatan Bastola ◽  
Kenneth E. Findley ◽  
Nathan T. Woodward

1991 ◽  
Vol 21 (4) ◽  
pp. 439-445 ◽  
Author(s):  
G. W. Adams ◽  
E. K. Morgenstern

Open-pollinated jack pine (Pinusbanksiana Lamb.) families were evaluated at four sites in New Brunswick after seven growing seasons for height growth, crown quality, stem straightness, branch angle, and relative branch diameter. Variance and covariance components were estimated to determine heritability of traits and genetic correlations between traits. Results indicated that there is a negative genetic correlation between height growth and all other traits. Selection based on height growth alone would result in degradation of quality traits of secondary economic importance at this age. A restricted selection index approach was examined for family roguing in seedling seed orchards because of the adverse genetic relationships between traits. Such an approach may be used to hold secondary quality traits constant, although some loss in maximum potential genetic gain in height at 7 years is incurred.


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