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1.
A flexible multi-dimensional QoS performance measure framework for distributed heterogeneous systems
Jong-Kook Kim Debra A. Hensgen Taylor Kidd Howard Jay Siegel David St. John Cynthia Irvine Tim Levin N. Wayne Porter Viktor K. Prasanna Richard F. Freund 《Cluster computing》2006,9(3):281-296
When users’ tasks in a distributed heterogeneous computing environment (e.g., cluster of heterogeneous computers) are allocated
resources, the total demand placed on some system resources by the tasks, for a given interval of time, may exceed the availability
of those resources. In such a case, some tasks may receive degraded service or be dropped from the system. One part of a measure
to quantify the success of a resource management system (RMS) in such a distributed environment is the collective value of
the tasks completed during an interval of time, as perceived by the user, application, or policy maker. The Flexible Integrated
System Capability (FISC) measure presented here is a measure for quantifying this collective value. The FISC measure is a
flexible multi-dimensional measure such that any task attribute can be inserted and may include priorities, versions of a
task or data, deadlines, situational mode, security, application- and domain-specific QoS, and task dependencies. For an environment
where it is important to investigate how well data communication requests are satisfied, the data communication request satisfied
can be the basis of the FISC measure instead of tasks completed. The motivation behind the FISC measure is to determine the
performance of resource management schemes if tasks have multiple attributes that needs to be satisfied. The goal of this
measure is to compare the results of different resource management heuristics that are trying to achieve the same performance
objective but with different approaches.
This research was supported by the DARPA/ITO Quorum Program, by the DARPA/ISO BADD Program and the Office of Naval Research
under ONR grant number N00014-97-1-0804, by the DARPA/ITO AICE program under contract numbers DABT63-99-C-0010 and DABT63-99-C-0012,
and by the Colorado State University George T. Abell Endowment. Intel and Microsoft donated some of the equipment used in
this research.
Jong-Kook Kim is pursuing a Ph.D. degree from the School of Electrical and Computer Engineering at Purdue University (expected in August
2004). Jong-Kook received his M.S. degree in electrical and computer engineering from Purdue University in May 2000. He received
his B.S. degree in electronic engineering from Korea University, Seoul, Korea in 1998. He has presented his work at several
international conferences and has been a reviewer for numerous conferences and journals. His research interests include heterogeneous
distributed computing, computer architecture, performance measure, resource management, evolutionary heuristics, and power-aware
computing. He is a student member of the IEEE, IEEE Computer Society, and ACM.
Debra Hensgen is a member of the Research and Evaluation Team at OpenTV in Mountain View, California. OpenTV produces middleware for set-top
boxes in support of interactive television. She received her Ph.D. in the area of Distributed Operating Systems from the University
of Kentucky. Prior to moving to private industry, as an Associate Professor in the systems area, she worked with students
and colleagues to design and develop tools and systems for resource management, network re-routing algorithms and systems
that preserve quality of service guarantees, and visualization tools for performance debugging of parallel and distributed
systems. She has published numerous papers concerning her contributions to the Concurra toolkit for automatically generating
safe, efficient concurrent code, the Graze parallel processing performance debugger, the SAAM path information base, and the
SmartNet and MSHN Resource Management Systems.
Taylor Kidd is currently a Software Architect for Vidiom Systems in Portland Oregon. His current work involves the writing of multi-company
industrial specifications and the architecting of software systems for the digital cable television industry. He has been
involved in the establishment of international specifications for digital interactive television in both Europe and in the
US. Prior to his current position, Dr. Kidd has been a researcher for the US Navy as well as an Associate Professor at the
Naval Postgraduate School. Dr Kidd received his Ph.D. in Electrical Engineering in 1991 from the University of California,
San Diego.
H. J. Siegel was appointed the George T. Abell Endowed Chair Distinguished Professor of Electrical and Computer Engineering at Colorado
State University (CSU) in August 2001, where he is also a Professor of Computer Science. In December 2002, he became the first
Director of the CSU Information Science and Technology Center (ISTeC). ISTeC is a university-wide organization for promoting,
facilitating, and enhancing CSU’s research, education, and outreach activities pertaining to the design and innovative application
of computer, communication, and information systems. From 1976 to 2001, he was a professor at Purdue University. He received
two BS degrees from MIT, and the MA, MSE, and PhD degrees from Princeton University. His research interests include parallel
and distributed computing, heterogeneous computing, robust computing systems, parallel algorithms, parallel machine interconnection
networks, and reconfigurable parallel computer systems. He has co-authored over 300 published papers on parallel and distributed
computing and communication, is an IEEE Fellow, is an ACM Fellow, was a Coeditor-in-Chief of the Journal of Parallel and Distributed
Computing, and was on the Editorial Boards of both the IEEE Transactions on Parallel and Distributed Systems and the IEEE
Transactions on Computers. He was Program Chair/Co-Chair of three major international conferences, General Chair/Co-Chair
of four international conferences, and Chair/Co-Chair of five workshops. He has been an international keynote speaker and
tutorial lecturer, and has consulted for industry and government.
David St. John is Chief Information Officer for WeatherFlow, Inc., a weather services company specializing in coastal weather observations
and forecasts. He received a master’s degree in Engineering from the University of California, Irvine. He spent several years
as the head of staff on the Management System for Heterogeneous Networks project in the Computer Science Department of the
Naval Postgraduate School. His current relationship with cluster computing is as a user of the Regional Atmospheric Modeling
System (RAMS), a numerical weather model developed at Colorado State University. WeatherFlow runs RAMS operationally on a
Linux-based cluster.
Cynthia Irvine is a Professor of Computer Science at the Naval Postgraduate School in Monterey, California. She received her Ph.D. from
Case Western Reserve University and her B.A. in Physics from Rice University. She joined the faculty of the Naval Postgraduate
School in 1994. Previously she worked in industry on the development of high assurance secure systems. In 2001, Dr. Irvine
received the Naval Information Assurance Award. Dr. Irvine is the Director of the Center for Information Systems Security
Studies and Research at the Naval Postgraduate School. She has served on special panels for NSF, DARPA, and OSD. In the area
of computer security education Dr. Irvine has most recently served as the general chair of the Third World Conference on Information
Security Education and the Fifth Workshop on Education in Computer Security. She co-chaired the NSF workshop on Cyber-security
Workforce Needs Assessment and Educational Innovation and was a participant in the Computing Research Association/NSF sponsored
Grand Challenges in Information Assurance meeting. She is a member of the editorial board of the Journal of Information Warfare
and has served as a reviewer and/or program committee member of a variety of security related conferences. She has written
over 100 papers and articles and has supervised the work of over 80 students. Professor Irvine is a member of the ACM, the
AAS, a life member of the ASP, and a Senior Member of the IEEE.
Timothy E. Levin is a Research Associate Professor at the Naval Postgraduate School. He has spent over 18 years working in the design, development,
evaluation, and verification of secure computer systems, including operating systems, databases and networks. His current
research interests include high assurance system design and analysis, development of models and methods for the dynamic selection
of QoS security attributes, and the application of formal methods to the development of secure computer systems.
Viktor K. Prasanna received his BS in Electronics Engineering from the Bangalore University and his MS from the School of Automation, Indian
Institute of Science. He obtained his Ph.D. in Computer Science from the Pennsylvania State University in 1983. Currently,
he is a Professor in the Department of Electrical Engineering as well as in the Department of Computer Science at the University
of Southern California, Los Angeles. He is also an associate member of the Center for Applied Mathematical Sciences (CAMS)
at USC. He served as the Division Director for the Computer Engineering Division during 1994–98. His research interests include
parallel and distributed systems, embedded systems, configurable architectures and high performance computing. Dr. Prasanna
has published extensively and consulted for industries in the above areas. He has served on the organizing committees of several
international meetings in VLSI computations, parallel computation, and high performance computing. He is the Steering Co-chair
of the International Parallel and Distributed Processing Symposium [merged IEEE International Parallel Processing Symposium
(IPPS) and the Symposium on Parallel and Distributed Processing (SPDP)] and is the Steering Chair of the International Conference
on High Performance Computing(HiPC). He serves on the editorial boards of the Journal of Parallel and Distributed Computing
and the Proceedings of the IEEE. He is the Editor-in-Chief of the IEEE Transactions on Computers. He was the founding Chair
of the IEEE Computer Society Technical Committee on Parallel Processing. He is a Fellow of the IEEE.
Richard F. Freund is the originator of GridIQ’s network scheduling concepts that arose from mathematical and computing approaches he developed
for the Department of Defense in the early 1980’s. Dr. Freund has over twenty-five years experience in computational mathematics,
algorithm design, high performance computing, distributed computing, network planning, and heterogeneous scheduling. Since
1989, Dr. Freund has published over 45 journal articles in these fields. He has also been an editor of special editions of
IEEE Computer and the Journal of Parallel and Distributed Computing. In addition, he is a founder of the Heterogeneous Computing
Workshop, held annually in conjunction with the International Parallel Processing Symposium. Dr. Freund is the recipient of
many awards, which includes the prestigious Department of Defense Meritorious Civilian Service Award in 1984 and the Lauritsen-Bennet
Award from the Space and Naval Warfare Systems Command in San Diego, California. 相似文献
2.
The capacity needs of online services are mainly determined by the volume of user loads. For large-scale distributed systems
running such services, it is quite difficult to match the capacities of various system components. In this paper, a novel
and systematic approach is proposed to profile services for resource optimization and capacity planning. We collect resource
consumption related measurements from various components across distributed systems and further search for constant relationships
between these measurements. If such relationships always hold under various workloads along time, we consider them as invariants
of the underlying system. After extracting many invariants from the system, given any volume of user loads, we can follow
these invariant relationships sequentially to estimate the capacity needs of individual components. By comparing the current
resource configurations against the estimated capacity needs, we can discover the weakest points that may deteriorate system
performance. Operators can consult such analytical results to optimize resource assignments and remove potential performance
bottlenecks. In this paper, we propose several algorithms to support capacity analysis and guide operator’s capacity planning
tasks. Our algorithms are evaluated with real systems and experimental results are also included to demonstrate the effectiveness
of our approach.
相似文献
Kenji YoshihiraEmail: |
3.
Discovering likely invariants of distributed transaction systems for autonomic system management 总被引:1,自引:0,他引:1
Large amount of monitoring data can be collected from distributed systems as the observables to analyze system behaviors.
However, without reasonable models to characterize systems, we can hardly interpret such monitoring data effectively for system
management. In this paper, a new concept named flow intensity is introduced to measure the intensity with which internal monitoring
data reacts to the volume of user requests in distributed transaction systems. We propose a novel approach to automatically
model and search relationships between the flow intensities measured at various points across the system. If the modeled relationships
hold all the time, they are regarded as invariants of the underlying system. Experimental results from a real system demonstrate
that such invariants widely exist in distributed transaction systems. Further we discuss how such invariants can be used to
characterize complex systems and support autonomic system management.
Guofei Jiang received the B.S. and Ph.D. degrees in electrical and computer engineering from Beijing Institute of Technology, China, in
1993 and 1998, respectively. During 1998–2000, he was a postdoctoral fellow in computer engineering at Dartmouth College,
NH. He is currently a research staff member with the Robust and Secure Systems Group in NEC Laboratories America at Princeton,
NJ. During 2000–2004, he was a research scientist in the Institute for Security Technology Studies at Dartmouth College. His
current research focus is on distributed system, dependable and secure computing, system and information theory. He has published
over 50 technical papers in these areas. He is an associate editor of IEEE Security and Privacy magazine and has served in
the program committees of many conferences.
Haifeng Chen received the BEng and MEng degrees, both in automation, from Southeast University, China, in 1994 and 1997 respectively,
and the PhD degree in computer engineering from Rutgers University, New Jersey, in 2004. He has worked as a researcher in
the Chinese national research institute of power automation. He is currently a research staff member at NEC laboratory America,
Princeton, NJ. His research interests include data mining, autonomic computing, pattern recognition and robust statistics.
Kenji Yoshihira received the B.E. in EE at University of Tokyo in 1996 and designed processor chips for enterprise computer at Hitachi Ltd.
for five years. He employed himself in CTO at Investoria Inc. in Japan to develop an Internet service system for financial
information distribution through 2002 and received the M.S. in CS at New York University in 2004. He is currently a research
staff member with the Robust and Secure Systems Group in NEC Laboratories America, inc. in NJ. His current research focus
is on distributed system and autonomic computing. 相似文献
4.
《Animal : an international journal of animal bioscience》2013,7(5):714-720
Genetically reducing boar taint using low-taint lines is considered the most sustainable and economic long-term alternative to surgical castration of male pigs. Owing to the high heritability of the main boar taint components (androstenone, skatole and indole), breeding is an excellent tool for reducing the number of tainted carcasses. To incorporate boar taint into breeding programmes, standardized performance testing is required. The objective of this study was to develop and formally present a performance test for the main boar taint compounds on live breeding candidates. First, a standardized performance test for boar taint was established. A biopsy device was developed to extract small tissue samples (200 to 300 mg) from breeding candidates. Quantification of boar taint components from these small samples using specialized chemical extraction methods proved accurate and repeatable (r = 0.938). Following establishment of the method, biopsy samples of 516 live boars (100 to 130 kg live weight) were collected in the second step. Various mixed linear models were tested for each boar taint compound; models were ranked in terms of their information content. Pedigree information of 2245 ancestors of biopsied animals was included, and genetic parameters were estimated using univariate and multivariate models. Androstenone (in μg/g liquid fat (LF): mean = 0.578, σ = 0.527), skatole (in μg/g LF: mean = 0.033, σ = 0.002) and indole (in μg/g LF: mean = 0.032, σ = 0.002) levels obtained by biopsy were plausible. Heritability estimates for androstenone calculated with univariate (0.453) and multivariate (0.452) analyses were comparable to those in the literature. Heritabilities for skatole (0.495) and indole (0.550) were higher than that for androstenone. Genetic and phenotypic correlations were similar to those published previously. Our results show that data on boar taint compounds from small adipose samples obtained by biopsy provide similar genetic parameters as that described in the literature for larger samples and are therefore a reliable performance test for boar taint in live breeding candidates. 相似文献
5.
6.
采用固相微萃取法和水蒸气蒸馏法提取出贵州产辣蓼的挥发性成分,运用GC-MS联用技术对挥发性成分进行分析鉴定,并采用峰面积归一法确定各成分的相对含量。固相微萃取物中鉴定出48个化合物,主要有β-石竹烯(27.02%),正癸醇(14.39%),十二醛(12.96%)等,水蒸气蒸馏物中鉴定出27个化合物,β-红没药烯(19.00%),补身树醇(15.25%),十二醛(14.41%)等。辣蓼中挥发性成分经两种不同提取方法成分存在明显差异。与文献数据比较,不同省区产的辣蓼挥发性成分差异很大。体外抗菌试验表明,辣蓼挥发性成分具有抑菌作用,这些研究结果为辣蓼的有效利用提供了依据。 相似文献
7.
高山峡谷地区森林流域分布式降雨-径流模型的构建与验证 总被引:1,自引:0,他引:1
根据岷江上游杂谷脑河流域典型的高山峡谷地区主要水文特点,选择通用性较强的水文过程模式,构建高山峡谷地区森林流域分布式降雨-径流过程模型,避免过多复杂的区域性模型参数率定,保证模型在相似地区的可移植性;并选择杂谷脑水文站上游地区进行降雨-径流过程模拟,得到1999年和2000年模拟时段长度为1000 h的两个径流过程,对模拟与实测的径流过程、累积径流量、洪峰流量与峰现时间等进行比较,其拟合效果较好.该模型结构简单,引入的经验参数较少,可推广应用到其它尺度流域. 相似文献
8.
Anita Dobek Hanna Zygmunt Kaczmarek H. Kielczewska 《Biometrical journal. Biometrische Zeitschrift》1989,31(6):753-757
The theory which analyses the progenies of line X tester crossing procedure and one group of homozygous parents is presented. This analysis allows to conclude on genetics of a quantitative character of parents included in the experiment. The statistics like variance among parents, mean variance of progenies of lines, variance of tester progeny means and covariance of testers with means of their progenies can be derived. On that base one can get four different genetic parameters of variance. In a special case of experiment, it is possible to test the significance of additive variance. 相似文献
9.
David W. Cameron 《Primates; journal of primatology》1991,32(3):329-343
This paper examines the pattern(s) of sexual dimorphism within the upper dentition ofProconsul specimens from the early Miocene of east Africa. These fossils are compared against the corresponding dentition ofPan troglodytes andGorilla gorilla using principal components and cluster analyses. This paper demonstrates that both sexes ofPan andGorilla are characterized by their own distinctive shape patterns. It is also demonstrated that someProconsul specimens examined here display a pattern that is dissimilar from otherProconsul specimens also examined. This suggests that at least two species ofProconsul may have to be recognized as having lived in this region during the early Miocene. The identification of distinct patterns
withinProconsul also suggests that their overall shape and size range are more similar toPan than toGorilla. 相似文献
10.
以同域分布于新疆南部的早春开花植物短穗柽柳(Tamarix laxa Willd)和紫杆柽柳(T.androssowii Litw)为材料,对它们的开花式样、花部特征、花报酬特点、传粉特性及交配方式进行比较研究。结果表明,2种植物居群和个体水平的花期及单花寿命间存在显著差异;紫杆柽柳的居群花期比短穗柽柳短,而短穗柽柳个体花期和单花寿命比紫杆柽柳长。2种柽柳的花瓣、雌雄蕊长度、花粉胚珠数及花粉/胚珠比值(P/O)间也存在显著差异。二者的花瓣、雌雄蕊均能分泌香味,访花频率与花蜜量均存在正相关。主要传粉者在短穗柽柳上的访花频率和沉积花粉效率高于紫杆柽柳,且存在显著差异。2种植物通过自花和异花授粉均可结实,属于混合交配系统;二者的自交不亲和指数及花粉限制程度间存在显著差异;紫杆柽柳的自交亲和性高于短穗柽柳,而短穗柽柳的花粉限制指数高于紫杆柽柳。因此,2种柽柳的开花式样、花部特征及花报酬的差异,是它们在传粉者受限的早春环境中为吸引更多的访花昆虫、提高雌性繁殖率所形成的繁殖对策。 相似文献
11.
12.
《Animal : an international journal of animal bioscience》2021,15(7):100255
Owing to the high concentrations of crude protein and beneficial fatty acids, hempseed cake could be a high-quality feedstuff for ruminants. The aim of the present study was to evaluate the effects of hempseed cake on milk production and quality, as well as haemato-chemical parameters in Alpine goats. In total, 28 French Alpine dairy goats were evaluated over 45 days. All goats were fed meadow hay supplemented with 1.2 kg/day feed mixture. The feed mixture in control group contained soybean meal and extruded soybean. In the first experimental group, soybean meal and extruded soybean were partially replaced with 60 g/kg of hempseed cake (HC6). In the second experimental group, soybean meal and extruded soybean were partially replaced with 120 g/kg of hempseed cake (HC12). Feeding goats with HC6 and HC12 did not influence milk yield, although the concentration of milk urea was higher in the HC12 compared to control group. The HC12 decreased the linoleic acid (LA)/linolenic acid (ALA) ratio and glutathione peroxidase activity in the serum. Under the conditions evaluated in this study, the inclusion of HC6 in the diet was optimal with respect to chemical composition of milk and haemato-chemical parameters. Even though HC12 resulted in lowered LA/ALA ratio, which confers functional properties to goat milk, HC12 increased milk urea concentrations, and worsened serum antioxidant status. 相似文献
13.
Genetic parameters, character association and path analysis for yield components of microtuber production in vitro and their field performance were studied in 37 potato (Solanum tuberosum L.) genotypes. Among the microtuber yield components, average microtuber weight had maximum genotypic (or phenotypic) coefficient of variation, heritability and predicted genetic advance; however, the estimated values of these genetic parameters were maximum for tuber yield among the field yield components. The heritability estimates of field yield components were higher than that of their corresponding in vitro yield components of microtuber production. The highest correlation coefficients between average microtuber weight and microtuber yield suggested that microtuber weight was more important than microtuber number in determining microtuber yield potential in vitro. However, tuber number was found to be more important than tuber weight in determining tuber yield potential under field conditions. Average microtuber weight had maximum direct effect on microtuber yield, whereas tuber number had maximum direct effect on tuber yield under field conditions. The study showed that the relative importance of the components of microtuber production in vitro differed from that of corresponding field yield components. The expression of a genotype for microtuber production in vitro is different from that of tuber production under field situation i.e. the performance of a genotype in vitro is not a measure of its field performance. 相似文献
14.
《Animal : an international journal of animal bioscience》2017,11(6):920-928
Objective of this study was to estimate genetic parameters of milk coagulation properties (MCPs) and individual laboratory cheese yield (ILCY) in a sample of 1018 Sarda breed ewes farmed in 47 flocks. Rennet coagulation time (RCT), curd-firming time (k20) and curd firmness (a30) were measured using Formagraph instrument, whereas ILCY were determined by a micromanufacturing protocol. About 10% of the milk samples did not coagulate within 30 min and 13% had zero value for k20. The average ILCY was 36%. (Co)variance components of considered traits were estimated by fitting both single- and multiple-trait animal models. Flock-test date explained from 13% to 28% of the phenotypic variance for MCPs and 26% for ILCY, respectively. The largest value of heritability was estimated for RCT (0.23±0.10), whereas it was about 0.15 for the other traits. Negative genetic correlations between RCT and a30 (−0.80±0.12), a30 and k20 (−0.91±0.09), and a30 and ILCY (−0.67±0.08) were observed. Interesting genetic correlations between MCPs and milk composition (rG>0.40) were estimated for pH, NaCl and casein. Results of the present study suggest to use only one out of three MCPs to measure milk renneting ability, due to high genetic correlations among them. Moreover, negative correlations between ILCY and MCPs suggest that great care should be taken when using these methods to estimate cheese yield from small milk samples. 相似文献
15.
Anders Wennström 《Plant Ecology》1999,141(1-2):93-97
This paper focuses on the effects of systemic rust and smut fungi on non-crop clonal plants and on the role of clonal growth in disease escape. Systemic rusts and smuts have a major effect on individual plants and populations as they affect growth and survival. Diseased plants may become distorted, stunted and/or elongated. However, the results are very variable. For example, growth and competitive ability may be reduced or increased, and survival may or may not be affected. Furthermore, clonal plants are able to escape systemic diseases by vigorous growth or by the production of long rhizomes. It is argued that a better understanding of the effects of systemic rusts and smuts on clonal individuals and populations requires not only more studies but ones that particularly focus on the life history of both host plant and pathogen and the mechanisms that allow parts of the clonal system to escape disease. 相似文献
16.
Hasan Fazli Mohammad Reza Behrouz Khoshghalb Mahmoud Tavakoli Mehdi Ghodrati Shojaei Gholam Reza Daryanabard Abdollah Soleimani Roudi 《Zeitschrift fur angewandte Ichthyologie》2021,37(6):857-867
The Caspian Sea (CS) is a unique ecosystem known for its several fish species, especially sturgeons. To exhaustively manage the fish stocks of this ecosystem, detailed knowledge of species composition, abundance, distribution, and the habitat traits of the living organisms is necessary. This study analyzed the diversity, spatial, and seasonal distribution of commercial demersal fish species, and examined the relationships between community structure and environmental variability in Iranian shelf waters of the CS. For this purpose, seasonally fish sampling took place between 2009 and 2011 with a bottom trawl. Among 11 fish species captured, Chelon spp., Rutilus kutum, and Vimba vimba showed the highest abundances (i.e. 88.49%, 10.67%, and 0.69%, respectively). Univariate and multivariate analyses showed differences in commercial fish assemblages (abundance and species richness) according to seasons and regions. Distance-based Linear Model (DisTLM) showed that eight environmental variables display significant linear relationships with the fauna resemblance matrix (p < .05). Based on AIC criteria, the combination of silt&clay, TOM, longitude, depth, bottom, and surface temperature used to build the parsimonious DisTLM model explain 67.03% of the total variability. The results revealed a biogeographical and temporal gradient from the west to the east and summer to winter, in terms of commercial demersal fish assemblages and species diversity, as a consequence of different geomorphological, bottom substratum conditions and benthic communities. 相似文献
17.
Although phospholipase C (PLC) is known to be activated by water-insoluble organic solvents, most activity assays have been designed to work in an aqueous milieu. Here a sensitive method is described for the determination of PLC activity in two-phase systems. The assay is based on the hydrolysis of phosphatidylcholine (PC) in chloroform/buffer. The initial rates of the reaction are determined by densitometric quantification of the product 1,2-diacylglycerol after its separation by high-performance TLC and staining with a CuSO4/H3PO4 or p-methoxybenzaldehyde/H2SO4 reagent. The method is examined for the determination of Vmax and Km values of PCs with varying length acyl chains (C10-C18). The comparison of the kinetic parameters with the Vmax and Km values of the same substrates in the conventional titrimetric assay, using sodium deoxycholate for micellization of PC, demonstrates the high efficiency of PLC in the two-phase emulsion system. 相似文献
18.
J. B. St. Clair W. T. Adams 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1991,81(4):541-550
Summary Open-pollinated Douglas-fir (Pseudotsuga menziesii var menziesii (Mirb.) Franco) families were tested in three contrasting competitive environments to test the hypothesis that relative performance as measured by total seedling dry weight is dependent upon distance or genotype of neighbors. The three competitive environmnts included (1) a mixture of individuals from all families planted at close spacing, (2) single (pure) family blocks planted at close spacing, and (3) individuals from all families planted at a wide, non-competitive spacing. Despite occasional large changes in rank between competitive environments and only moderate correlations of family means between competitive environments, the family x competitive environment interaction was non-significant. Furthermore, families did not differ significantly in competitive ability or density tolerance. The competitive environment in which seedlings were grown, however, had a large effect on estimates of variance components, which in turn led to large differences in estimates of heritability and genetic gain. Evaluation of families in mixture resulted in the largest estimates of heritability, while evaluation in pure family blocks resulted in the lowest. Analysis of correlated response to selection indicated that testing and selection in mixture result in the largest estimated gain, even if progeny of selected individuals are subsequently grown in a pure or non-competitive environment.Paper No. 2659 of the Forest Research Laboratory, Oregon State University 相似文献
19.
Estimation of genetic parameters for growth performance and carcass traits in Mukota pigs 总被引:1,自引:0,他引:1
The objective of the study was to determine genetic parameters for growth and carcass traits in Mukota pigs, maintained on a fibrous diet. Records (n = 1961) were obtained from a population housed at the University of Zimbabwe Farm (Harare, Zimbabwe) between January 1998 and August 2003. Backfat thickness was measured at 50 and 75 mm (K5 and K7.5), respectively. Carcass length (CL) was measured from the anterior edge of the first rib to the pubic bone using a measuring tape. Variance components were estimated using a model that accounted for direct, common environmental litter and maternal genetic effects, using average information restricted maximum likelihood. Heritability estimates for average daily gain from birth to weaning (ADGW) and average daily gain from weaning to 12 weeks (ADG1) were 0.15 and 0.27, respectively. Maternal genetic effects accounted for 2.6% of variation for ADG1. Heritability for average daily gain from 12 weeks to slaughter (ADG2) was 0.20. Common environmental litter effects accounted for 18% of phenotypic variance for cold dressed mass (CDM). Heritability estimates for CDM and CL were 0.32 and 0.62, respectively. Maternal genetic effects accounted for 10.5% of variance in CL. Heritability estimates for K5 and K7.5 were 0.64 and 0.40, respectively. The CDM was positively genetically correlated to K5, but negative to K7.5. The K5 and K7.5 had a high genetic correlation (0.88). Genetic correlations between ADGW and K5, K7.5 and CL were 0.30, 0.05 and 0.35, respectively. The existence of sufficient genetic variation makes genetic improvement for many growth and carcass traits in the Mukota breed possible through effective selection methods. 相似文献