scholarly journals Phenotypical resistance correlation networks for 10 non-typhoidalSalmonellasubpopulations in an active antimicrobial surveillance programme

2018 ◽  
Vol 146 (8) ◽  
pp. 991-1002 ◽  
Author(s):  
W. J. Love ◽  
K. A. Zawack ◽  
J. G. Booth ◽  
Y. T. Gröhn ◽  
C. Lanzas

AbstractAntimicrobials play a critical role in treating cases of invasive non-typhoidal salmonellosis (iNTS) and other diseases, but efficacy is hindered by resistant pathogens. Selection for phenotypical resistance may occur via several mechanisms. The current study aims to identify correlations that would allow indirect selection of increased resistance to ceftriaxone, ciprofloxacin and azithromycin to improve antimicrobial stewardship. These are medically important antibiotics for treating iNTS, but these resistances persist in non-TyphiSalmonellaserotypes even though they are not licensed for use in US food animals. A set of 2875Salmonella entericaisolates collected from animal sources by the National Antimicrobial Resistance Monitoring System were stratified in to 10 subpopulations based on serotype and host species. Collateral resistances in each subpopulation were estimated as network models of minimum inhibitory concentration partial correlations. Ceftriaxone sensitivity was correlated with otherβ-lactam resistances, and less commonly resistances to tetracycline, trimethoprim-sulfamethoxazole or kanamycin. Azithromycin resistance was frequently correlated with chloramphenicol resistance. Indirect selection for ciprofloxacin resistance via collateral selection appears unlikely. Density of the ACSSuT subgraph resistance aligned well with the phenotypical frequency. The current study identifies several important resistances in iNTS serotypes and further research is needed to identify the causative genetic correlations.

2021 ◽  
Vol 11 (2) ◽  
pp. 31-50
Author(s):  
S.L. Artemenkov

Network modeling, which has emerged in recent years, can be successfully applied to the consideration of relationships between measurable psychological variables. In this context, psychological variables are understood as directly affecting each other, and not as a consequence of a latent construct. The article describes regularization methods that can be used to effectively assess the sparse and interpretable network structure based on partial correlations of psychological indicators. An overview of the glasso regularization procedure using EBIC model selection for evaluating an ordered sparse network of partial correlations is presented. The issues of performing this analysis in R in the presence of normal and non-normal data distribution are considered, taking into account the influence of the hyperparameter, which is manually set by the researcher. The considered approach is also interesting as a way to visualize possible causal connections between variables. This review bridges the gap related to the lack of an accessible description in Russian of this approach, which is still uncommon in Russia and at the same time promising.


1983 ◽  
Vol 36 (2) ◽  
pp. 277-283
Author(s):  
J. S. Cheema ◽  
S. B. Basu

ABSTRACTThe study was based on 1156 lactation records of 545 Murrah buffaloes. Initial milk yield, peak yield, ascending phase milk yield and days to attain peak daily production, the means of which were 26·7 kg, 10·3 kg, 407 kg and 58·9 days respectively, were all affected by period, season and parity of calving. Heifers recorded the least initial milk yield and peak yield and took the longest time to reach peak production. Peak yield was the most important single factor (R2 = 0·41) in causing variation in 43-week milk yield. The heritability estimates for initial, peak and ascending phase milk yields and days to attain peak yield were 0·35, 0·51, 0·27 and 0·13 respectively, whilst that for 43-week milk yield was 0·18. Peak yield had the highest phenotypic (rP = 0·64) and genetic correlations (ra = 0·68 ± 0·19) with the 43-week milk yield. Other genetic correlations with the 43-week milk yield were low and non-significant. The results indicated that indirect selection for peak yield would be more effective than direct selection for improving the 43-week milk yield in buffaloes.


2007 ◽  
Vol 58 (5) ◽  
pp. 432 ◽  
Author(s):  
M. A. Babar ◽  
M. van Ginkel ◽  
M. P. Reynolds ◽  
B. Prasad ◽  
A. R. Klatt

The objectives of this study were to assess the potential of using spectral reflectance indices (SRIs) as an indirect selection tool for grain yield in wheat under irrigated conditions. This paper demonstrates the genetic correlation between grain yield and SRIs, heritability and expected response to selection for grain yield and SRIs, correlated response to selection for grain yield estimated from SRIs, and efficiency of indirect selection for grain yield using SRIs in different spring wheat populations. Four field experiments, GHIST (15 CIMMYT globally adapted genotypes), RLs1 (25 random F3-derived families), RLs2 (36 random F3-derived families), and RLs3 (64 random F5-derived families) were conducted under irrigated conditions at the CIMMYT research station in north-west Mexico in 3 different years. Spectral reflectance was measured at 3 growth stages (booting, heading, and grain filling) and 7 SRIs were calculated using average values of spectral reflectance at heading and grain filling. Five previously developed SRIs (PRI, WI, RNDVI, GNDVI, SR), and 2 newly calculated SRIs (NWI-1 and NWI-2) were evaluated in the experiments. In general, the within- and between-year genetic correlations between grain yield and SRIs were significant. Three NIR-based indices (WI, NWI-1, and NWI-2) showed higher genetic correlations (0.73–0.92) with grain yield than the other indices (0.35–0.67), and these observations were consistent in all populations. Broad-sense heritability estimates for all indices were in general moderate to high (0.60–0.80), and higher than grain yield (0.45–0.70). The realised heritability for the 3 NIR-based indices was higher than for the other indices and for grain yield itself. Expected response to selection for all indices was moderate to high (0.54–0.85). The correlated response for grain yield estimated from the 3 NIR-based indices (0.59–0.64) was much higher than the correlated response for grain yield estimated from the other indices (0.31–0.46), and the efficiency of indirect selection for these 3 NIR-based indices was 90–96% of the efficiency of direct selection for grain yield. These results demonstrate the potential for using the 3 NIR-based SRI tools in breeding programs for selecting for increased genetic gains for yield.


2021 ◽  
Vol 17 (1) ◽  
pp. 79-92
Author(s):  
Alessandra Ferraiolo de Freitas ◽  
Ricardo Lopes ◽  
Raimundo Nonato Vieira da Cunha ◽  
Antônio José de Abreu Pina ◽  
Marcos Deon Vilela Resende ◽  
...  

Interspecific hybridization between Elaeis oleiferaand Elaeisguineensis(HIE OxG) is explored in plant breeding programs to meet the demand for resistant cultivars to fatal yellowing, which is the biggest phytosanitary problem in E. guineensisplants in South America, including Brazil. In addition to resistance to fatal yellowing, cultivars should have high oil yield, which depends directly on bunch production and oil content in the bunches (O/FFB). The obtaining of genetic gains in O/FFBfor OxG requires information on the genotypic values of the breeding population and the understanding of how the components of the bunch are related to this characteristic in this type of material. Thus, the objective of this work was toestimate genotypic values and genetic correlations for bunch components and analyze the potential of using these components in the selection of gains for O/FFB. The physical composition and oil content in mesocarp of 840 bunches from 39 HIE OxG F1 progenies were analyzed. Genotypic values for bunch components were estimated using the procedure REML/BLUP andwere obtained from genetic correlations between them. All evaluated components presented genetic variation with possibility of gains through selection, especially the oil content in the bunch (O/FFB), which presented variability above 23%. The selection for O/FFBwill mainly result in bunches with a higher fruit proportion over the weight of the bunch (TF/FFB), greater oil contents in mesocarp of normal and parthenocarpic fruits, and lower proportion of empty spikelets. Considering the high and positive correlations between O/FFBand the evaluated characteristics and the practicality of evaluation, the characteristics with higher potential for indirect selection to increase O/FFBare TF/FFBand proportion of mesocarp in normal fruits.


2021 ◽  
Vol 11 (3) ◽  
pp. 36-56
Author(s):  
S.L. Artemenkov

In the context of network modeling, psychological variables are understood as directly affecting each other, and not as a consequence of latent constructs. An efficient assessment of networks showing relationships between measured variables can be carried out using the methods of regularization of the network of partial correlations. This article provides an example of constructing a regularized network of partial correlations in the R software environment (it is showing the relationship between the personality traits of adolescents and their behavior in virtual space using the example of the social network VKontakte) and examines the features of constructing and analyzing ordered networks of partial correlations. A list of potential problems arising when using the considered network methodology is presented. The issues related to sample size and reproducibility of the network, difficulties in interpreting networks, and comparing different networks with each other, including both network models and models of latent variables, are considered.


1996 ◽  
Vol 26 (9) ◽  
pp. 1643-1650 ◽  
Author(s):  
B.L. Greaves ◽  
N.M.G. Borralho ◽  
C.A. Raymond ◽  
A. Farrington

Six hundred 7-year-old Eucalyptusnitens (Dean & Maid.) trees from 50 open-pollinated families were measured for wood density and Pilodyn penetration across two contrasting sites in eastern Victoria, Australia. Eight Pilodyn observations, two from each of four aspects, were made at a height of 1.3 m. Density was measured on whole disks cut from 1.3 m. Heritability of Pilodyn penetration and disk density at 1.3 m were 0.60 and 0.73, respectively. Phenotypic and genetic correlations between Pilodyn penetration and density at 1.3 m were −0.59 and −0.92, respectively. The high repeatability of Pilodyn penetration (0.90) suggests that only two observations per tree would be required for indirect selection of density. Direct index selection for density gave an expected 13% gain (assuming a selection intensity of 1%), compared with a 11% gain by using indirect Pilodyn selection, a selection efficiency of 84%. However, Pilodyn sampling is faster, cheaper, and not destructive, thus resulting in overall higher expected gains for selection of trees or culling of seedling seed orchards in comparison with the more destructive direct assessment of density.


1965 ◽  
Vol 16 (6) ◽  
pp. 997 ◽  
Author(s):  
SSY Young ◽  
GH Brown ◽  
Turner H Newton ◽  
CHS Dolling

Genetic and phenotypic parameters for body weight and greasy fleece weight at weaning were estimated in a flock of Australian Merinos. Maternal handicaps were found to be more severe at weaning than at the older age of 15–16 months. Lambs born to 2-year-old ewes were 2–3 lb lighter in body weight at weaning and 0.2 lb lighter in greasy fleece weight than the offspring of adult ewes. Twin lambs were on the average 6–7 lb lighter than singles and cut 0.5 lb less greasy wool. Greasy fleece weight at weaning was found to be fairly highly heritable but only moderately repeatable. The repeatability and heritability of weaning body weight were both low. The genetic correlations estimated here were associated with appreciable sampling errors, but the estimates strongly suggested high and positive correlations between measurements at weaning and at 15–16 months for both traits. A general consideration of the relative efficiency of direct versus indirect selection, based on the information obtained in this study, leads to the conclusion that for greater genetic gains, mass selection for greasy wool weight and body weight at weaning should be carried out on measurements at 15–16 months of age, rather than at weaning.


HortScience ◽  
1990 ◽  
Vol 25 (11) ◽  
pp. 1357F-1358
Author(s):  
Yiran Yu ◽  
James Harding ◽  
Thomas Byrne

Genetic components of variance and heritability of flowering time were estimated for five generations of the Davis Populationof Gerbera hybrids, Composite, Estimates of narrow-sense heritability averaged 0.50 and broad-sense heritability averaged 0.77 using the NCII design. Narrow-sense heritability was also estimated with two models of parent-offspring regression, resulting in average heritability of 0.49 and 0.51. Estimates of components of variance indicated that the major genetic effect controlling flowering time is additive. However, the dominance component accounted for 28% of the total variance; the environmental component was only 23%. Flowering time is negatively correlated with cut-flower yield. The phenotypic coefficient was –0.34; genetic correlations were –0.47 when estimated from the NCII design, and –0.72 when estimated from the parent-off-spring method. A practical model was constructed to assess the efficiency of indirect selection for cut-flower yield using flowering time as a marker trait. The advantages of indirect selection accruing from increased population size and reduced generation time are discussed.


2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 18-18
Author(s):  
Leticia P Sanglard ◽  
Felipe Hickmann ◽  
Yijian Huang ◽  
Kent A Gray ◽  
Daniel Linhares ◽  
...  

Abstract Immunoglobulin G antibody response, measured as sample-to-positive (S/P) ratio, to Porcine Reproductive and Respiratory Syndrome virus (PRRSV) has been proposed as an indicator trait for improved reproductive performance in PRRSV-infected purebred sows and PRRSV-vaccinated crossbred gilts. In this study, we investigated the genetic correlations (rg) of S/P ratio following a PRRSV outbreak and PRRSV-vaccination with performance in non-exposed and PRRSV-exposed sows. PRRSV outbreak phase was defined based on previously described methodologies after the detection of typical clinical signs of PRRSV infection. 541 Landrace sows had S/P ratio measured at ~54 days after the beginning of the PRRSV outbreak (S/Poutbreak), and 906 Landrace x Large White naïve F1 gilts had S/P ratio measured at ~50 days after vaccination with a commercial modified live PRRSV vaccine (S/PVx). 711 and 428 Landrace sows had reproductive performance recorded before and during the PRRSV outbreak, respectively. 811 vaccinated F1 animals had farrowing performance for up to 3 parities. All animals were genotyped for ~28K SNPs. The estimate of rg of S/Poutbreakwith S/PVx was high (rg±SE = 0.72±0.18). Estimates of rg of S/Poutbreak with reproductive performance in F1 sows were low to moderate, ranging from 0.05±0.23 (number stillborn) to 0.30±0.20 (total number born). Estimates of rg of S/PVxwith reproductive performance in non-infected purebred sows were moderate and favorable with number born alive (0.50±0.23), but low (0 to -0.11±0.23) with litter mortality traits. Estimates of rg of S/PVx were moderate and negative (-0.47±0.18) with the number of mummies in PRRSV-infected purebred sows and low with other traits (-0.29±0.18 for total number born to 0.05±0.18 for number stillborn). These results indicate that selection for antibody response following a PRRSV outbreak collected in purebred sows and to PRRSV vaccination collected in commercial crossbred gilts may increase litter size of non-infected and PRRSV-exposed purebred and commercial crossbred sows.


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