Cluster Distance-Based Regression

2020 ◽  
pp. 385-397
Author(s):  
J. Fernando Vera ◽  
Eva Boj del Val
Keyword(s):  
Cluster Distance

scholarly journals A Precise Benchmark for Cluster Scaling Relations: Fundamental Plane, Mass Plane and IMF in the Coma Cluster from Dynamical Models

2020 ◽  
Author(s):  
Shravan Shetty ◽  
Michele Cappellari ◽  
Richard M McDermid ◽  
Davor Krajnović ◽  
P T de Zeeuw ◽  
...  
Keyword(s):  
Galaxy Formation ◽  
Scaling Relations ◽  
Coma Cluster ◽  
Dynamical Models ◽  
Fundamental Plane ◽  
Cluster Galaxies ◽  
Dynamical Scaling ◽  
Small Uncertainty ◽  
Cluster Distance ◽  
Using Data

Abstract We study a sample of 148 early-type galaxies in the Coma cluster using SDSS photometry and spectra, and calibrate our results using detailed dynamical models for a subset of these galaxies, to create a precise benchmark for dynamical scaling relations in high-density environments. For these galaxies, we successfully measured global galaxy properties, modeled stellar populations, and created dynamical models, and support the results using detailed dynamical models of 16 galaxies, including the two most massive cluster galaxies, using data taken with the SAURON IFU. By design, the study provides minimal scatter in derived scaling relations due to the small uncertainty in the relative distances of galaxies compared to the cluster distance. Our results demonstrate low (≤55% for 90th percentile) dark matter fractions in the inner 1Re of galaxies. Owing to the study design, we produce the tightest, to our knowledge, IMF-σe relation of galaxies, with a slope consistent with that seen in local galaxies. Leveraging our dynamical models, we transform the classical Fundamental Plane of the galaxies to the Mass Plane. We find that the coefficients of the mass plane are close to predictions from the virial theorem, and have significantly lower scatter compared to the Fundamental plane. We show that Coma galaxies occupy similar locations in the (M* - Re) and (M* - σe) relations as local field galaxies but are older. This, and the fact we find only three slow rotators in the cluster, is consistent with the scenario of hierarchical galaxy formation and expectations of the kinematic morphology-density relation.

scholarly journals Refining the true parameters of the open cluster NGC 4852

2009 ◽  
Vol 5 (S266) ◽  
pp. 539-539
Author(s):  
Gladys Solivella ◽  
Edgard Giorg ◽  
Rubén Vázquez ◽  
Giovanni Carraro
Keyword(s):  
Emission Line ◽  
Open Cluster ◽  
Open Clusters ◽  
Occurrence Rate ◽  
Hot Stars ◽  
Cluster Area ◽  
Young Object ◽  
Cluster Distance ◽  
Be Star ◽  
Compact Cluster

AbstractNGC 4852 is a moderately compact cluster centered at α2000 = 13 : 00 : 09; δ = −59 : 36 : 48, located near the center of an Hα superring. This cluster forms part of an extended region including young stellar aggregates inside a circle with a radius of 3 degrees, where many show an abundance of emission line stars. In the field of this cluster, two stars of known type exist: Wray 15–1039 (emission-line object) and CD −58:4845 (emission-line star). We do not yet know whether the Be phase is transient or whether it is just what randomly happens in some hot stars. It appears that Be star may be found even in clusters as old as 70 Myr with a high occurrence rate in clusters of 25–27 Myr old. A recent photometric survey in NGC 4852 down to V = 22 – 23 mag established that NGC 4852 is about 200 – 250 Myr old, located at 1.1 kpc from the Sun and with a mean E(B − V) = 0.45 mag. Since the presence of potential Be-type stars in the cluster area suggests it may be a very young object instead of moderately old, we decided to carry out spectroscopy for 33 selected stars and CCD UBVI photometry for the bright objects in the cluster area. This way, we attempt to clarify their evolutionary state and include them in the framework of emission-line stars and open clusters. From our analysis, we agree with the cluster distance and reddening determined by earlier studies, but we derive that the age of NGC 4852 is younger than 40 Myr.

Genetic divergence in Indian mustard (Brassica juncea L. Czern. & Coss.

2021 ◽  
Vol 50 (1) ◽  
pp. 37-44
Author(s):  
Nupur Malviya ◽  
K Kumar ◽  
DK Upadhyay
Keyword(s):  
Brassica Juncea ◽  
Genetic Divergence ◽  
Indian Mustard ◽  
Cluster Distance ◽  
Parental Lines

Genetic divergence was carried out in 15 Indian mustard varieties/strains, 4 testers and 60 F1s developed by crossing 15 lines with 4 testers. Based on D2 values between the pair of genotypes, 19 parental lines were grouped into five clusters in E1 (timely sown) & E2 (late sown) condition. In E1, cluster II was the largest having 8 genotypes followed by cluster I and IV with four genotypes. Whereas, in E2 cluster I was largest having 9 genotypes followed by cluster V which had four genotypes. In E1 the intra-cluster distance ranged from 0.00 (cluster V) to 581.64 (cluster IV). Cluster IV and V were the most diverse with inter-cluster distance of 7169.70 followed by cluster II and V (4829.11). Whereas, in E2 the intra-cluster distance ranged from 0.00 (cluster IV) to 296.03 (cluster V). Clusters IV and V were the most diverse with inter-cluster distance of 1894.16. The 60 F1s were grouped into eight clusters in E1 and E2. In E1, the maximum number of genotypes were grouped in clusters I and VI (12) and the intra-cluster distance ranged from 111.59 to 318.07. The maximum inter-cluster distance was observed between cluster IV and VIII (3554.76). Whereas, in E2 maximum number of genotypes grouped in cluster III (15) and intra-cluster distance ranged from 0.00 to 351.31. The maximum inter-cluster distance (D2) was observed between cluster V and VIII (43829.30).

scholarly journals Morphological characterization and genetic diversity in lentil (Lens culinaris medikus ssp. Culinaris) germplasm

2014 ◽  
Vol 4 (1) ◽  
pp. 70-76
Author(s):  
KU Ahamed ◽  
B Akhter ◽  
MR Islam ◽  
MR Humaun ◽  
MJ Alam
Keyword(s):  
Seed Weight ◽  
Female Flower ◽  
Morphological Characterization ◽  
Flower Initiation ◽  
Mean Values ◽  
Maximum Value ◽  
Cluster Distance ◽  
The Mean ◽  
100 Seed Weight ◽  
Number Of Seeds

Genetic divergence of 110 lentil germplasm with checks was assessed based on morphological traits using multivariate analysis. Mahalanobis generalized distance (D2) analysis was used to group the lentil genotypes. Significant variations among lentil genotypes were observed in respect of days to 1st flowering, days to 50% flowering, days to maturity, plant height, and number of pods per peduncle, number of pods per plant, number of seeds per plant, 100 seed weight and yield per plant. Considering the mean values, the germplasm were grouped into ten clusters. The highest number of genotypes (17) was in cluster X and lowest (5) both in cluster II and IV. Cluster IV had the highest cluster mean for number of pods per plant (297.08), number of seeds per plant (594.16), 100 seed weight (1.44 g) and yield per plant (8.53 g). Among them, the highest inter-cluster distance was obtained between the cluster IV and I (24.61) followed by IV and III (22.33), while the lowest was between IX and II (1.63). The maximum value of inter-cluster distance indicated that genotypes belonging to cluster IV were far diverged from those of cluster I. The first female flower initiation was earlier in BD-3812 (49 days) in cluster I and cluster IV had highest grain yield per plant (8.53). BD-3807 produced significant maximum number of pods per plant (298.40) in cluster IV. DOI: http://dx.doi.org/10.3329/ijarit.v4i1.21095 Int. J. Agril. Res. Innov. & Tech. 4 (1): 70-76, June, 2014

scholarly journals Genetic diversity analysis of parental lines for hybrid development in rice (Oryza sativa L.)

2013 ◽  
Vol 37 (4) ◽  
pp. 617-624 ◽  
Author(s):  
MJ Hasan ◽  
Umma Kulsum ◽  
MMH Rahman ◽  
MMH Chowdhury ◽  
AZMKA Chowdhury
Keyword(s):  
Genetic Diversity ◽  
Oryza Sativa L ◽  
Principal Component ◽  
Mean Value ◽  
Cluster Distance ◽  
Parental Lines ◽  
Almost All ◽  
Yield Maximization ◽  
Hybrid Development ◽  
Panicle Weight

Genetic divergence of 40 parental lines comprising 30 restorer and 10 maintainer lines were studied through Mohalanobis's D2 and principal component analysis for eleven characters. Genotypes were grouped into five different clusters. Cluster V comprised maximum number of genotypes (thirteen) followed by cluster I and II. The inter-cluster distance was maximum between clusters I and V (13.495) indicating wide genetic diversity between these two clusters followed by the distance between cluster I and 11 (9.489), cluster IV, and cluster V (8.969) and cluster I and cluster III (8.039). The minimum inter-cluster distance was observed between cluster II and cluster III (3.034) followed by cluster 111 and cluster IV (3.834) and cluster II and cluster V (4.945) indicating that the genotypes of these clusters were genetically close. The intra cluster distance in the entire five clusters was more or less low which indicated that the genotypes within the same cluster were closely related. Among the characters panicle weight contributed most for divergence in the studied parental lines. Difference in cluster means existed for almost all the characters studied. Highest mean value for number of effective tillers (7.8), days to 50% flowering (95.5), panicles/m2 (192.6), panicle weight (2.9), spikelet fertility (84.8), number of grains/panicle (177.8), days to maturity (123.6), and grain yield/plot (1065.5) were observed in cluster I indicated the parental lines fallen in this cluster having the genetic potentiality to contribute better for yield maximization of hybrid rice. DOI: http://dx.doi.org/10.3329/bjar.v37i4.14386 Bangladesh J. Agril. Res. 37(4): 617-624, December 2012

scholarly journals Genetic divergence in bitter gourd (Momordica charntia L.)

2013 ◽  
Vol 38 (2) ◽  
pp. 125-134
Author(s):  
BC Kundu ◽  
MM Hossain ◽  
MA Khaleque Mian ◽  
IH Mian
Keyword(s):  
Genetic Divergence ◽  
Seed Weight ◽  
Male Flower ◽  
Bitter Gourd ◽  
Flower Opening ◽  
Green Fruit ◽  
Fruit Maturity ◽  
Cluster Distance ◽  
Geographical Position ◽  
Seed Width

The genetic divergence among 36 genotypes of bitter gourd (Momordica charantia L.) was determined through PCA, PCO, CVA, Cluster analysis (CLSA) and Mohalanobis’s D2 analysis. Through multivariate analysis based on 22 characters 36 genotypes were grouped into six distant clusters. Cluster VI includes maximum genotypes (12) followed by cluster I (6) and cluster II (6). Cluster V, cluster III and cluster I comprised 5, 4 and 3 genotypes respectively. The inter-cluster distances were higher than the intra-cluster distances. The inter-cluster distance was maximum between cluster III and IV (28.71) followed by the distance between cluster I and cluster IV (23.61). The intra-cluster distances in all the 6 clusters were more or less low indicating the closeness of genotypes within the same cluster. The highest intra-cluster distance was observed for cluster III (1.84) followed by the cluster I (1.38). The genotypes within the same clusters were collected from different places and genotypes collected in the same place fall in different cluster, which indicated that genetic divergence are not dependent on its geographical position from where the genotypes were collected. The genetic diversity of 36 genotypes was also assessed through PCA. The first three components accounted for 60.04% of the total variation. Days to first male flower opening, number of primary branches per vine, fruit yield per vine, days to green fruit maturity, seed weight per fruit mature seed width had the highest contribution towards the divergence. Cluster diagram exhibited that the genotypes include in the cluster III were far diverse from the genotypes of cluster IV while the genotypes belonging to the cluster II and VI were least diversed. DOI: http://dx.doi.org/10.3329/jasbs.v38i2.15593 J. Asiat. Soc. Bangladesh, Sci. 38(2): 125-134, December 2012 J. Asiat. Soc. Bangladesh, Sci. 38(2): 125-134, December 2012

scholarly journals Magnetic properties of iron cluster/chromium matrix nanocomposites

2015 ◽  
Vol 6 ◽  
pp. 1158-1163 ◽  
Author(s):  
Arne Fischer ◽  
Robert Kruk ◽  
Di Wang ◽  
Horst Hahn
Keyword(s):  
Exchange Bias ◽  
Cluster Size ◽  
Complete Characterization ◽  
Blocking Temperature ◽  
Antiferromagnetic Coupling ◽  
Magnetic Characteristics ◽  
Iron Cluster ◽  
The Matrix ◽  
Cluster Distance ◽  
Matrix Nanocomposites

A custom-designed apparatus was used for the fine-tuned co-deposition of preformed Fe clusters into antiferromagnetic Cr matrices. Three series of samples with precisely defined cluster sizes, with accuracy to a few atoms, and controlled concentrations were fabricated, followed by a complete characterization of structure and magnetic performance. Relevant magnetic characteristics, reflecting the ferromagnetic/antiferromagnetic coupling between Fe clusters and the Cr matrix, i.e., blocking temperature, coercivity field, and exchange bias were measured and their dependence on cluster size and cluster concentration in the matrix was analyzed. It is evident that the blocking temperatures are clearly affected by both the cluster size and their concentration in the Cr matrix. In contrast the coercivity shows hardly any dependence on size or inter-cluster distance. The exchange bias was found to be strongly sensitive to the cluster size but not to the inter-cluster distances. Therefore, it was concluded to be an effect that is purely localized at the interfaces.

scholarly journals Identification of high yielding maize hybrids through genetic diversity analysis

2020 ◽  
Vol 11 (4) ◽  
Author(s):  
Chandrashekar Rangu ◽  
Sangilimuthu Alagar Yadav ◽  
Ghosh Syamal Krishna
Keyword(s):  
Morphological Character ◽  
Zea Mays L ◽  
Diversity Analysis ◽  
Genetic Diversity Analysis ◽  
Maize Hybrids ◽  
Commercial Cultivation ◽  
High Consumption ◽  
Food Shortages ◽  
Cluster Distance ◽  
High Yields

Maize (Zea mays L.) is one of the most important crops in cereals with respect to its uses, adaptability and potentiality. There is a great need for the development of high yielding hybrids, to fulfill the high consumption of the increasing population. The present study was designed to identify the superior hybrid combinations in maize through diversity analysis of 30 Maize lines and 5 testers. Morphological character values of these lines were subjected to D2 statistics. Based on the D2 values, the experimental material (30 lines & 5 testers) has been grouped in to 6 clusters. Toucher’s method was used for calculating inter-cluster distances. The highest value of inter-cluster distance (1625509) was observed from cluster V to cluster VI and next between cluster V & III (1169553) and followed by cluster I & V (1078876). More diversity observed in between these clusters since having more inter-cluster distances. When we cross the lines from V & VI clusters there are high chances for getting good heterotic hybrids. From this study we have recommended 16 hybrids for farmer cultivation. The recommended hybrids (L29 X T3), (L29 X T5), (L2 X T3), (L5 X T3), (L22 X T3), (L11 X T3), (L30 X T3), (L24 X T3), (L19 X T3), (L2 X T5), (L5 X T5), (L22 X T5), (L11 X T5), (L30 X T5), (L24 X T5), (L19 X T5) will support farmers in commercial cultivation to achieve good yields. To the society, these hybrids may be the source for over-coming food shortages and demand by their high yields.

scholarly journals Genetic Divergence (D2) Evaluation in Horsegram [Macrotyloma uniflorum (L) Verdcout] Genotypes

2021 ◽  
Vol 10 (9) ◽  
pp. 291-300
Author(s):  
Rakesh Singh ◽  
J. L. Salam Mahendra
Keyword(s):  
Seed Yield ◽  
Quantitative Traits ◽  
Research Station ◽  
College Of Agriculture ◽  
Mean Values ◽  
Macrotyloma Uniflorum ◽  
Days To Maturity ◽  
Cluster Distance ◽  
Check Variety ◽  
Total Divergence

The experiment was performed at Research cum Instructional Farm, Shaheed Gundadhoor College of Agriculture and Research Station, Kumhrawand, Jagdalpur, Chhattisgarh. A total of 56germplasm lines and 1 check variety of horsegram were assessed for 10 quantitative traits during kharif2018.Genotypes were grouped into eight clusters. Clusters VI had maximum intra cluster distance while inter cluster distance was maximum between cluster VI and cluster VIII. Cluster III and cluster VIII had highest mean values for seed yield per plant characters. The characters viz., pods per plant followed by days to maturity and seed yield per plant were main contribution to total divergence. Based on the result genotypes belonging to clusters II, III and VIII are recommended for hybridization, as these genotypes showed good performance for seed yield and belong to the diverse clusters.

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