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Genetic diversity is one of the useful tools to select appropriate lines for hybridization. Twenty short-statured maize inbred lines were taken for present study, which were collected from CIMMYT India and Mexico through Plant Breeding Division, Bangladesh Agricultural Research Institute (BARI), Gazipur. This experiment was conducted from November 2015 to April 2016 to identify parental lines to produce single cross short statured maize hybrids. From the genetic diversity studies, the importance of both additive and non-additive gene actions for the expression of yield and yield contributing characters were found. Values of vector I and II revealed that both the vectors had positive values for date of silking, plant height, rows/cob, grains/row and yield. These results indicated that these five characters had highest contribution towards divergence. Based on the relative magnitude of D2 values; 20 inbred lines were grouped into five clusters. Seven inbred lines were selected on the basis of genetic diversity and per se performance which will be crossed separately in a half-diallel fashion to develop hybrids.

The present investigation was carried out at the research farm of the Division of Plant Breeding & Genetics, SKUAST –Jammu, Chatha. The experimental material of the present study comprised 20 true breeding facultative type winter wheat lines which were evaluated under rainfed conditions in a RBD. The best ten winter wheat lines (Arkaan, Blue boy, China 4435893, Drina, Drina NS 720, Nordersprez, WW12, WW21, WW23 and WW25) used as females and three spring wheat (PBW175, PBW 644 and WH 1080) were used as male parents to develop the experimental material for line x tester mating design. 30F1s and advanced 30F2 seeds along with 13 parents were sown in the Rabi 2016-17 in a RBD under rainfed conditions. Observations were recorded on yield traits. The mean squares for comparisons of parents’ vs crosses were significant. Combining ability analysis carried over F1 and F2 generation revealed that variance for crosses, testers and partly in lines was significant for almost all the traits. The GCA effects were greater than SCA effects for most of the traits. The compassion of relative magnitude of GCA and SCA variances indicated greater magnitude of GCA variance than SCA variance yield traits indicating the presence of additive gene action for the inheritance of these traits. On the basis of overall ranking of the parents for GCA, the lines Arkaan, Blue boy, Nordersprez, Drina and WW25 and in testers WH1080, PBW 175 revealed desirable significant effect for many traits.).

The objective of this work was to evaluate four parental lines of cucumber which included: ‘Zeina’ (Zna), ‘Beit Alpha’ (BA), ‘Straight 8’ (Strght 8) and ‘Calypso’ (Capso) and six F1s generated by diallel cross, using randomized complete block design with three replications to study heterosis and combining ability for yield and yield component traits. Estimated heterosis showed that cross ‘Zna × Capso’ had the highest Better Parent (BP) heterosis in total fruit yield/ha while ‘BA × Capso’ had the highest Mid Parent (MP) heterosis in the same trait. Significant general (GCA) and specific (SCA) combining ability variances were obtained in all the traits implying that both the additive and non-additive gene effects operated in the genetic expression of the traits. Relative magnitude of GCA and SCA variances indicated preponderance of additive gene action for all the traits. ‘Beit Alpha’ and ‘Straight 8’ are best general combiners while ‘BA × Capso’ and ‘Capso × Strght 8’ were the best specific combiners for total fruit yield. Keywords: Cucumber, Hybrid vigour, Half diallel crosses, GCA, SCA

With the aim of increasing interest in exploitation of heterosis in rice, there is an urgent need to make available various CMS lines and good restoration capability lines for combining ability tests. The knowledge of combining ability is useful to assess nicking ability in self-pollinated crops and at the same time elucidate the nature and magnitude of gene actions involved, provides to the breeder about insight of nature and relative magnitude of fixable and non-fixable genetic variances i.e. due to dominance or epistatic components. This study provides useful information for the selection of donor parents for effective breeding programme. Such informations are required to design efficient breeding programmes for rapid dynamic and strategic crop improvement for quantitative along with qualitative nature of traits. Variation with in crosses and parents were significant for all the characters and also magnitude of variance among parents vs crosses were also significantly for all characters except day to 50% flowering. The SCA variances were higher than the corresponding GCA variances for all the traits. The significant and positive gca effects for grain yield per plant were exhibited only by 3 males namely, Swarna, NDRK 5026 and NDRK 5032 which were found to be good general combiners. Among 24 hybrids studied, none of the hybrids exhibited high sca effects for all 10 characters.

Background: In the present study, we have investigated the morphological variation in a set of five Opuntia species from the Algerian steppes using 49 UPOV descriptors. Questions: which of the 49 descriptors that can be used as powerful estimators of the phenotypic diversity within Opuntia species? How is the morphological diversity patterned in Algerian Opuntia ? Species study/ Mathematical model: Opuntia ficus-indica, Opuntia amycleae, Opuntia streptacantha, Opuntia engelmannii, Opuntia robusta . Principal Components Analysis (PCA) and Hierarchical Cluster Analysis were used. Study site: Four counties were studied located in the Algerian steppes. The present research was carried out during 2014. Methods: 49 descriptors adopted by the International Union for the Protection of New Varieties of Plants (UPOV) were employed in the present research, where cladode, flower and fruit traits were used to determine the overall degree of polymorphism among 5 Opuntia species. Results: Principal Component Analysis and Hierarchical Cluster Analysis indicated a consistent differentiation between all studied species. The relative magnitude of the first two PCA eigenvectors showed that 8 descriptors out of 49 were identified as the most important descriptors for the classification of the species. The dendrogram performed on the calculated Euclidean distances between all species pairs allowed the identification of 3 groups, unlike the PCA that identified 4 groups. The species Opuntia ficus-indica and Opuntia amycleae were identified as very close morphologically. Conclusions: The present outcome represents a paramount step towards the fast selection of interesting species and for their best management and conservation.

An insight knowledge nature and relative magnitude of gene actions involved and combining ability is useful for a breeder to assess nicking ability in self-pollinated crops. In this connection, an attempt was made to esti- mate the gene action and combining ability of 70 newly developed CMS based heterotic rice hybrids developed from ten newly developed CMS lines and seven testers were evaluated for grain yield and its components at Hybrid rice scheme, ZARS, V. C. Farm, Mandya. Among the lines, CMS 2 had significant gca effects at 1% level of significance in desired direction for four traits viz., panicle weight, pollen fertility, spikelet fertility and number of spikelets per pan- icle. Out of seven testers, KMR 3 found to be good general combiner for five traits viz., days to 50 per cent flower- ing, plant height, number of tillers per plant, number of panicles per plant and grain L/B ratio. Among the 70 hybrids, CMS1 × KMR3 was good specific combiner for grain yield per plant and grain L/B ratio. It further revealed that SCA variances were higher than the GCA variances for all the characters which indicated preponderance of non-additive gene action. Hence, CMS 2 and KMR 3 are identified as promising lines which can be used in further breeding pro- gramme.

In special dietary products for people intolerant to gluten, gluten content is not supposed to exceed the regulatory thresholds. Enzyme-linked immunosorbent assays (ELISAs) are routinely used to quantitate gluten in these products. They measure gliadin/gluten with high specificity and sensitivity, but they have some limitations. Quantitative and qualitative variability of the target proteins among wheat cultivars is a factor that may cause inaccurate results. One of the aims of this work was to characterize the protein composition of five wheat cultivars grown in multiple harvest years and their blends by reversed-phase high-performance liquid chromatography (RP-HPLC). The gliadin/gluten content of these wheat flours was also analysed with two commercial ELISA kits. The effect of differences in protein profiles between the flours from an individual cultivar and the blend of five cultivars, harvest years, as well as processing procedures (dough forming and baking) on the results of two ELISA kits was investigated and their relative magnitude was determined. Among the factors investigated, the differences between flours had the greatest impact on gliadin recoveries.

The purpose of the research is Hereford breed calves meat quality improvement by harnessing the potential of the canadian selection bulls. Experiments were performed in LLC «K. H. Polanskoe» Bolshechernigovsk district of Samara region. The subject of investigations was the carcasses of Hereford steers of the breed obtained in the cows insemination of populations of canadian selection bulls stair: Wide Load 391W (group 1), upper Cut 20U (group 2), absolute 49S (group 3) and the descendants of domestic breeding bulls (control group). It was found that the calves of Hereford breed have good meat qualities. Exit steam carcasses in all groups was not less than 56.0% and the yield of pulp – not less than 79.0%. In calves, obtained from canadian selection bulls , meat quality was better expressed. The descendants of imported bulls by mass of steam carcass exceeded the indicators of the descendants of domestic bulls by the figure of 3.7-7.0% on exit of the flesh – 4.3 to 7.7%, they also had the advantage of index meat 2.1-4.2 percent. Canadian Herefords bulls were characterized by a greater mass of most valuable cuts of the carcass. They have plenty of hip part was 4.2 to 10.7 kg more than the domestic descendents. In the relative magnitude of this difference was 13.6 and 5.3%. The researches have allowed to draw a conclusion about expediency of use of canadian selection sires Hereford for improvement of meat quality of local Hereford farms, where this species are bred.

The maintenance of hydraulic function during and after a drought event is crucial for tree survival, but the importance of non-structural carbohydrates (NSCs) in the recovery phase is still debated. We tested whether higher NSC availability facilitates post-drought hydraulic recovery, by applying a short-term drought (Sdr) and a long-term drought combined with shading (Ldr+sh) in Fraxinus ornus and Ostrya carpinifolia. Plants were then re-irrigated and recovery was checked 24 h later, by measuring water potential, stem percentage loss of hydraulic conductance (PLC) and NSC content. The relative magnitude of hydraulic and carbon constraints was also assessed in desiccated plants. During drought, PLC increased only in F. ornus, while it was maintained almost constant in O. carpinifolia due to tighter stomatal control of xylem pressure (i.e. more isohydric). In F. ornus, only Sdr plants maintained high NSC contents at the end of drought and, when re-irrigated, recovered PLC to control values. Whereas hydraulic failure was ubiquitous, only F. ornus depleted NSC reserves at mortality. Our results suggest that preserving higher NSC content at the end of a drought can be important for the hydraulic resilience of trees.

Variation in individual growth rates contributes to changes over time in compensatory population growth and surplus production for marine fishes. However, there is little evidence regarding the prevalence and magnitude of time-varying growth for exploited marine fishes in general, whether it is best approximated using changes in length-at-age or weight-at-length parameters, or how it can be represented parsimoniously. We therefore use a database of average weight in each year and age for 91 marine fish stocks from 25 species, and fit models with random variation in length and weight parameters by year, age, or cohort (birth-year). Results show that year effects are more parsimonious than age or cohort effects and that variation in length and weight parameters provide roughly similar fit to average weight-at-age data, although length parameters show a greater magnitude of variability than weight parameters. Finally, the saturated model can explain nearly 2/3 of total variability, while a single time-varying factor can explain nearly 1/2 of variability in weight-at-age data. We conclude that time-varying growth can often be estimated parsimoniously using a single time-varying factor, either internally or prior to including ‘empirical’ weight at age in population dynamics models.

Background/Aim: Diet is the main source of exposure to several environmental contaminants, but the relative magnitude of various food groups is unknown. Our aim was to identify dietary determinants...

The effect of free mate choice on the relative magnitude of fitness benefits has been examined among various species. The majority of the data show significant fitness benefits of mating with partners of an individual’s own choice, highlighting elevated behavioral compatibility between partners with free mate choice. Similarities between humans and other species that benefit from free mate choice led us to hypothesize that it also confers reproductive benefits in Homo sapiens. To test this hypothesis, we conducted a study among three indigenous societies—the Tsimane’, Yali, and Bhotiya—who employ natural birth control. In all three samples, we compared the marriages arranged by parents with the non-arranged ones in terms of number of offspring. Here, we show that there were no significant relationships between type of marriage and the total number of alive children and number of dead children among the three sampled groups. The presented study is the first to date to examine the fitness benefits of free mate choice in humans. In discussion we present limitations of our research and discuss the possibility of love having a beneficial influence in terms of the number of offspring.

Combining ability study was carried out in a 10 x 10 diallel set of dry beans (Phaseolus vulgaris L.) for seed yield and its component characters. The 45 F1s generated by crossing ten diverse lines and their parents were evaluated in Randomized Block Design (RBD) in two replications at three locations during Kharif, 2008. Analysis of variance revealed that both gca and sca were influenced by environments, which suggested that studies be conducted over environments to get unbiased estimates. The sca x environment interaction was greater than gca x environment interaction for most of the traits. The relative magnitude of gca and sca variation indicated that greater magnitude of sca variances for all the traits, indicating greater importance of non additive gene action for the inheritance of these traits. SKUA-R-607 and SKUA-R-608 showed high combining ability for seed yield and yield attributing traits. The most promising crosses in order of merit for seed yield were Shalimar Rajmash 1 x SKUA-R-607, SKUA-R-608 x SKUA-R-106 and Shalimar Rajmash -1 x SKUA- R-612. These promising crosses may be improved through conventional breeding methods such as biparental mating and diallel selective meeting, thereafter followed by pedigree method of selection, so as the tight linkage, if any, may be broken and transgressive segregants may be isolated. DOI: http://dx.doi.org/10.3329/sja.v10i2.18324 SAARC J. Agri., 10(2): 61-69 (2012)

An efficiency analysis revealed the relative magnitude of wood traits that distinguishes efficient radiata pine logs to produce New Zealand structural grades. Technical and cost efficiencies were obtained by using data envelopment analysis (DEA). Wood trait prices used to perform the cost efficiency corresponded to economic weights derived from a partial regression. These values were 1.1, 29.7, 0.3 and −0.4 NZ $/m 3 for small end diameter (cm), stiffness (GPa), basic density (kg/m 3 ) and largest branch (mm) respectively. The most efficient logs were those with the highest difference between recovery value and price. There were positive and significant correlations between technical efficiency and wood stiffness (0.46, p p

We assessed the relative magnitude of various factors (year, preservation method, continent, investigator, and taxonomic level) affecting prediction of invertebrate dry mass (DM) in light of the variability of assessments of invertebrate density. We developed 34 length (L)–DM relationships for Oligochaeta and 17 freshwater invertebrate families belonging to Mollusca, Crustacea, and Insecta. Comparison of our predicted DM for reference-size individuals with values from 120 other published equations revealed that 31% of predicted values were within our 95% CI and 73% were within a 2× DM range (i.e., between 0.5× and 2×). Interannual differences in exponent (slope) or scale factor (intercept) of L–DM relationships were detected for 6 of the 7 taxa investigated, but represented only 3% of total variance in predicted DM. Similarly, preservation methods and measured body dimension each accounted for a small (0–3%) fraction of total variance. Variation among investigators (12–50%) and continents (1–17%) ...

It is increasingly realized that the potential for male mate choice is widespread across many taxa. However, measurements of the relative magnitude of the fitness benefits that such choice can confer are lacking. Here, we directly measured, in a comprehensive set of tests that manipulated key variables, the fitness benefits of male mate choice in Drosophila melanogaster by measuring egg production in females that were chosen or rejected by males. The results provided significant evidence for male mate choice. In absolute terms, the observed degree of choice increased male fitness by an average of only 1.59 eggs. However, using a novel technique we show that this benefit of choice represented 14.5% of the maximum potential fitness benefit of choice. The magnitude of mate choice was not significantly altered by variation in (1) mate compatibility, (2) phenotypic plasticity in male mate choice, or (3) whether choosing males were preferred or nonpreferred by females. Overall, we show that male mate choice represents a subtle but significant opportunity for sexual selection, and we offer a novel and widely applicable method for quantifying mate choice.

The objective of this research was to estimate the relative magnitude of effects included in contemporary groups (CG) and their interactions with adjusted and actual 120 d and 210 d weights in 72, 731 male and female Nelore calves born from 1985 to 2005 in 40 herds from PMGRN (Genetic Improvement Program of Nelore). Ten models with different CG structures were compared. The analyses were done using the general linear models (GLM) procedure run in SAS software. All of the effects included in the CG for each model were significant (p < 0.001) for the four traits analyzed. Inclusion of semester or trimester of birth as part of a CG was more appropriate than its use as an independent effect in the model because it accounted for interactions with the other effects in the CG. Calf sex (CS) and dam age at calving (DAC) had similar effects across the models, which suggested independence from other effects in these models. The corresponding age deviation effect had a larger impact on actual weight at 120 d than any other effect in all of the models tested. The use of actual weights in models with no CS effect in CG provides an alternative that would allow better genetic connectedness among CGs and greater accuracy in genetic evaluations.

The assimilation of PCDD/Fs and PCBs in chickens, pigs and sheep was investigated in studies using conventional animal husbandry practices. Closely matched samples of muscle (meat), liver, kidneys, eggs, milk, feed, soil and grass were collected of which 105 were analysed. The data obtained were consistent with the PCB and PCDD/F TEQ concentrations to be expected in rural background locations. A slight decline in TEQ values in meat with increasing age was evident in pigs, sheep and broiler chickens. Higher TEQ values in meat from outdoor pigs compared to those raised indoors, and an increase in TEQs in eggs as a result of free-range conditions might be attributable to additional contaminant intakes from soil. TEQ values in samples of sheep meat were slightly higher than those for pigs and chickens and market ready lowland sheep showed higher meat TEQs than the highland species. PCDD/F TEQs were considerably higher in the liver than meat. Contaminant transfer from dietary sources was investigated using biotransfer factors (BTFs) which tended to be higher in chickens than in sheep or pigs. BTFs for all animals declined in magnitude with age, but on average, BTFs for pigs and chickens showed a sharper initial decline than for sheep. The relative magnitude of the BTFs usually followed the order: (highest first) PCB 153, PCB 169, PCB 126, 1,2,3,7,8-PeCDD/2,3,4,7,8-PeCDF and 2,3,7,8-TCDD. This may suggest that higher chlorinated congeners accumulate more readily in meat tissues. Congener-specific BTF variations were found to be associated with variables such as dietary composition during rearing, differences between feed and animal species.

The study of avian eggshell structure, including composition, pigmentation, thickness, and strength,hasimportantecologicalandeconomicimplications.Previousinvestigatorshaveusedavarietyoftechniques to derive either direct measures or indirect estimates of eggshell thickness. Assessing the repeatability and method agreement of different techniques is necessary to permit comparison of eggshell thickness values from different studies on various genetic stocks, populations, and species. We recorded and analyzed measurements of eggshell thickness using two methods, micrometers and scanning electron microscopy (SEM), for several Palaeognathae and Neognathae taxa, including nonpasserines and passerines. Applying a tolerance-interval approach, we found that repeatability of measurements for eggs with thinner shells (

Discord in the estimated gene trees among loci can be attributed to both the process of mutation and incomplete lineage sorting. Effectively modeling these two sources of variation—mutational and coalescent variance—provides two distinct challenges for phylogenetic studies. Despite extensive investigation on mutational models for gene-tree estimation over the past two decades and recent attention to modeling of the coalescent process for phylogenetic estimation, the effects of these two variances have yet to be evaluated simultaneously. Here, we partition the effects of mutational and coalescent processes on phylogenetic accuracy by comparing the accuracy of species trees estimated from gene trees (i.e., the actual coalescent genealogies) with that of species trees estimated from estimated gene trees (i.e., trees estimated from nucleotide sequences, which contain both coalescent and mutational variance). Not only is there a significant contribution of both mutational and coalescent variance to errors in species-tree estimates, but the relative magnitude of the effects on the accuracy of species-tree estimation also differs systematically depending on 1) the timing of divergence, 2) the sampling design, and 3) the method used for species-tree estimation. These findings explain why using more information contained in gene trees (e.g., topology and branch lengths as opposed to just topology) does not necessarily translate into pronounced gains in accuracy, highlighting the strengths and limits of different methods for species-tree estimation. Differences in accuracy scores between methods for different sampling regimes also emphasize that it would be a mistake to assume more computationally intensive species-tree estimation procedures that will always provide better estimates of species trees. To the contrary, the performance of a method depends not only on the method per se but also on the compatibilities between the input genetic data and the method as determined by the relative impact of mutational and coalescent variance. (Coalescence; gene tree; lineage sorting; mutation; phylogenetics; sample design; species tree.)

The experiment was conducted at the experimental farm of Olericulture Division, Horticulture Research Centre, Bangladesh Agricultural Research Institute, Joydebpur, Gazipur from May to August 2003. Combining ability effects were estimated for yield and component traits in a 8 x 8 diallel design excluding reciprocals in tomato. The variances for general combining ability (GCA) and specific combining ability (SCA) were highly significant indicating the presence of additive as well as non-additive gene effects in the traits studied. The relative magnitude of these variances indicated that additive gene effects were more prominent for all the characters under study. The tomato genotype P1 (TM051) proved to be the best general combiner for yield followed by P2 (TM053) and the combinations P1xP3, P1xP5 and P5xP7 were identified as the best specific combiner for earliness, yield per plant, number of fruits per plant and individual fruit weight.

The effects of cultivar mixtures on the evolution of aggressiveness of barley powdery mildew (Blumeria graminis f.sp. hordei) were modelled. It was found that the rate and direction of evolution of pathogen aggressiveness in a race-non-specific system and value at equilibrium, depends on initial resistance levels, proportions of component cultivars, autodeposition rates, the relative magnitude of the benefit of autoinfection, and the cost of alloinfection of spores. In the model, mixing cultivars in any proportions tended to reduce the aggressiveness of pathogens at equilibrium compared with pure stands, but this effect decreased when two mixture components were extremely unbalanced in proportion. Under low and medium autodeposition rates, the best control of the evolution of the pathogen was achieved by mixing two components in roughly equal proportions. The magnitude of aggressiveness at equilibrium increased as autodeposition rates increased. Though the level of initial resistance of mixture components did not have an impact on the aggressiveness of pathogens at equilibrium, it strongly influenced the transient values of aggressiveness and therefore the total amount of disease caused over an evolutionary period. The cost to the pathogen of alloinfection and benefit of autoinfection per se did not affect the final level of aggressiveness, but did affect the time to reach equilibrium. However, the ratio of the cost to the benefit did influence the final aggressiveness of the pathogen.

Guazuma crinita Mart. is a fast-growing timber tree in the Peruvian Amazon. A trial of 11 Peruvian provenances was established in three planting zones. Tree growth at 6, 12, 18 and 30 months and wood density at 32 months were analyzed across and within zones. Zones accounted for more variation than provenances. Density varied significantly due to provenances in the analysis across zones, whereas growth exhibited strong provenance by zone interactions. The local provenance grew well and produced relatively dense wood in all zones. The relative magnitude of variation due to provenances depended on the planting zone. Density was greater in the lower than in the upper stem. Density increased with longitude from the more humid to the drier part of the sample region. In general, correlations indicated that larger trees had lower density and a larger difference in density between the lower and upper stem, but the strength of these relationships depended on the provenance and zone. Results suggest that fast-growing provenances can be selected at an early age without significantly reducing wood density. The local provenance is recommended for reforestation pending future research demonstrating the superiority of foreign provenances. Some practical implications for tree-improvement programs are discussed.

The kinematic gait characteristics of six species of birds in three groups were compared. The groups studied were herons (Gray Herons and Little Egrets), ground-feeders (Domestic Pigeons and Gray Starlings), and waterfowl (Pintails and Black-headed Gulls). The results showed that the relative stride frequency was greater in the waterfowl than in the other species. Complementary to this, the amplitude of the movements was smaller in the waterfowl than in the others. These differences between the waterfowl and the other species might be caused by their morphological and/or physiological adaptation to swimming. Another possible cause for these differences was the magnitude of head bobbing, as the ground-feeders and herons, which walk with head bobbing, showed a large relative stride length and excursion angle, while the waterfowl, which do not head-bob, walk with a relatively short stride length and small excursion angle. Moreover, the relative magnitude of head movement during walking was especially large in Little Egrets, which showed an especially large relative stride length and excursion angle. These parameters may have some mechanical relationships with each other.

Swallowing and biting responses in the marine mollusk Aplysia are both mediated by a cyclical alternation of protraction and retraction movements of the grasping structure, the radula and underlying odontophore, within the feeding apparatus of the animal, the buccal mass. In vivo observations demonstrate that Aplysia biting is associated with strong protractions and rapid initial retractions, whereas Aplysia swallowing is associated with weaker protractions and slower initial retractions. During biting, the musculature joining the radula/odontophore to the buccal mass (termed the "hinge") is stretched more than in swallowing. To test the hypothesis that stretch of the hinge might contribute to rapid retractions observed in biting, we analyzed the hinge's passive properties. During biting, the hinge is stretched sufficiently to assist retraction. In contrast, during swallowing, the hinge is not stretched sufficiently for its passive forces to assist retraction, because the odontophore's anterior movement is smaller than during biting. A quantitative model demonstrated that steady-state passive forces were sufficient to generate the retraction movements observed during biting. Experimental measures of the relative magnitude of the hinge's active and passive forces at the protraction displacements of biting suggest that passive forces are at least a third of the total force.

The performance of 21 sugarcane progenies (Saccharum spp.) obtained in a diallel cross between three and seven varieties was evaluated from progeny tests conducted in Jau Agronomy Experimental Station, Instituto Agronomico de Campinas, Sao Paulo State, Brazil. Measurements for average Brix, stool weight, stalk height, stalk diameter and stalk number were analyzed to obtain estimates of the relative magnitude of general (GCA) and specific combining ability (SCA) effects. Significant differences among GCA of the varieties were obtained for all characters, except stalk height, while significant differences among SCA effects were not expressed only for stalk height. An evaluation of variance components revealed that the variances of GCA for average Brix was almost the same of the component for SCA effects. A similar ratio for the two effects was obtained for stalk diameter. For average Brix, the ratio of GCA/SCA effects was bigger than the ratio observed for the other characters. This indicated that with the relatively bigger proportion of the genetic variance resulting from general effects, parental breeding value can be estimated from progeny of open-pollinated or polycross seed. The proportion of the genetic variance resulting from GCA effects of the other studied characters, the parental breeding value could be estimated from control-pollinated progeny tests.

The causes of individual variability in the length of time between human immunodeficiency virus (HIV) infection and the development of AIDS are incompletely understood. Here, we present a novel hypothesis: that the relative magnitude of responses to HIV mediated by CD4+ T regulatory (Treg) cells vs. CD4+ T effector (Teff) cells is a critical determinant of variability in AIDS progression rates. We use a simple mathematical model to show that this hypothesis can plausibly explain three qualitatively different outcomes of HIV infection – fast or slow progression to AIDS, and long-term non-progression to AIDS – based on individual variation in underlying T-cell response. This hypothesis also provides a unifying explanation for various other empirical observations, suggesting in particular that both aging and certain dual infections increase the rate of AIDS progression because they increase the strength of the Treg cell response. We discuss potential therapeutic implications of our results.

Finite element models of the proximal femur at birth, 2 years of age, and at 8 years of age were constructed to investigate stress patterns under different loading conditions. These loading conditions represent typical activities of a normal developing child and abnormal activity associated with muscle spasticity. The hypothesis is that the shear stresses in the growth plate correlate with the neckshaft angle as associated with valgus and normal development. Loads for the finite element models were derived from a separate muscle model used to calculate the forces across the hip joint for an arbitrary subject and activity. Results show there is an inverse relationship between the relative magnitude of the shear stress in the growth plate and the developing neck-shaft angle. The relatively high shear stresses generated by normal activity in the 2-year-old’s growth plate correlate with the decrease in neck-shaft angle that accompanies normal development. Alternatively, lower shear stresses are generated in the growth plate by loading conditions representing spasticity. These lower magnitude shear stresses correlate with a valgus deformity, which is often observed clinically.

The diffusion gradient chamber (DGC) has proven to be a useful experimental tool for studying population-level microbial growth and chemotaxis. A mathematical model capable of reproducing the population-level patterns formed as a result of cellular growth and chemotaxis in the DGC has been developed. The model consists of coupled partial differential balance equations for cells, chemoattractants, and a nutrient, which are solved simultaneously by the alternating direction implicit method. Modeling simulation results were compared with population-level migration patterns of Escherichia coli growing on glycerol and responding to a gradient of the chemoattractant aspartate for two different initial conditions. To accurately reproduce the experimental results, a second chemoattractant equation was necessary. The second chemoattractant has been identified as oxygen by directly measuring oxygen gradients in the DGC. Important trends observed experimentally and reproduced by the model include the formation of a chemotactic wave, a reduction in the wave velocity as it encounters higher chemoattractant concentrations, and chemotaxis in response to two different chemoattractants simultaneously. The model was also used to study the relative magnitude of cell fluxes due to random motility and chemotaxis, and the suppression of chemotaxis due to receptor saturation.

1. The Latin square design (LSD) is usually preferred over the randomized complete block design (RCBD) in insect trapping experiments because of its ability to cater for variations due to both sites and days in addition to treatments. 2. The efficiency of LSD relative to RCBD is quantified for tsetse trapping experiments using a data set comprising 2200 trap-days. LSD was found to be more efficient than RCBD when blocks ≅ days, but less efficient when blocks ≅ sites, especially when experiments involve only three or four treatments. 3. The importance of sites relative to days as sources of variation in tsetse trapping experiments is quantified. Effects due to site differences were shown to be more important than day to day variability. 4. By relating LSD relative efficiency to the relative importance of sites, it was found that LSD efficiency depended on the relative magnitude of effects of sites and days.

Despite years of research on small mammal disturbance effects on plant diversity, predicting the direction and magnitude of these effects remains elusive. Models such as the intermediate disturbance hypothesis, the perturbation hypothesis, or the ecosystem engineering hypothesis of small mammal disturbance, show considerable overlap but fail to account for key variable interactions and thus provide mainly post hoc explanations. Recent reviews have emphasized the importance of small mammals to basic and applied ecology. Re‐examining the mechanisms underlying their disturbance effects is thus timely. Here I present the Slope‐Hump Model, which integrates previous models and insights from the literature, and which is capable of predicting the direction and relative magnitude of disturbance effects on plant diversity. These predictions qualitatively match the results of recent meta‐analyses. The model also suggests new patterns and predictions that can stimulate both pure and applied ecology research.

The challenge hypothesis posits that acute increases in testosterone (T) during male–male competition enhance performance and survivability while limiting the physiological costs of consistently high T. Human challenge hypothesis research focuses on young men in industrial populations, who have higher baseline T levels than men in subsistence populations. We tested whether the Tsimane, pathogenically stressed forager-horticulturalists of the Bolivian Amazon, would express acute T increases in response to physical competition. Saliva was collected from 88 Tsimane men (aged 16–59 years) before and after a competitive soccer match. Tsimane men had significantly lower baseline levels of T ( β = −0.41, p < 0.001) when compared with age-matched United States (US) males. Linear mixed-effects models were used to establish that T increased significantly immediately following competition ( β = 0.23, p < 0.001), remaining high 1 h later ( β = 0.09, p = 0.007); equivalent to 30.1 and 15.5 per cent increases in T, respectively. We did not find larger increases in T among winners ( p = 0.412), although T increases were positively associated with self-rated performance ( β = 9.07, p = 0.004). These results suggest that despite lower levels of T than US males, Tsimane males exhibit acute increases in T at the same relative magnitude reported by studies in industrialized settings, with larger increases in T for those who report better individual performance.

It is often assumed that oviposition rate is the currency that parasitoids should maximize in order to maximize reproductive success. Female parasitoids foraging in a patchy environment face a variety of mortality risks that influence the survival of both themselves and their offspring. Maximizing oviposition rate ignores these risks. A model is developed to analyse the influence of female and offspring mortality risks on optimal patch residence time in time-limited solitary parasitoids. The optimal compromize between minimizing a female's own mortality risks and the mortality risks of her offspring in characterized. The optimal patch residence time is shown to be dependent on the relative magnitude of these mortality risks, as well as the rate with which reproductive success accumulates while on a patch. If travel time between patches is not fixed but a random variable, the optimal patch residence time decreases. However, variability in travel time increases expectations of total reproductive success. The model is illustrated with a case study in two aphid parasitoids.

Herbicides with new modes of action are badly needed to manage the evolution of resistance of weeds to existing herbicides. Yet no major new mode of action has been introduced to the market place for about 20 years. There are probably several reasons for this. New potential products may have remained dormant owing to concerns that glyphosate-resistant (GR) crops have reduced the market for a new herbicide. The capture of a large fraction of the herbicide market by glyphosate with GR crops led to significantly diminished herbicide discovery efforts. Some of the reduced herbicide discovery research was also due to company consolidations and the availability of more generic herbicides. Another problem might be that the best herbicide molecular target sites may have already been discovered. However, target sites that are not utilized, for which there are inhibitors that are highly effective at killing plants, suggests that this is not true. Results of modern methods of target site discovery (e.g. gene knockout methods) are mostly not public, but there is no evidence of good herbicides with new target sites coming from these approaches. In summary, there are several reasons for a long dry period for new herbicide target sites; however, the relative magnitude of each is unclear. The economic stimulus to the herbicide industry caused by the evolution of herbicide-resistant weeds, especially GR weeds, may result in one or more new modes of action becoming available in the not too distant future. Copyright © 2011 Society of Chemical Industry

To elucidate the pattern of inheritance and determine the relative magnitude of various genetic effects for maturity and flowering attributes in subtropical maize.Four white grain maize inbred lines from flint group of corn, two with late maturity and two with early maturity, were used. These contrasting inbred lines were crossed to form four crosses. Six generations (P1, P2, F1, F2, BC1, and BC2) were developed for each individual cross. These were evaluated in triplicate trial for two consecutive years.Both dominance gene action and epistatic interaction played major role in governing inheritance of days to pollen shedding, 50% silking, anthesis silking interval and maturity.Preponderance of dominance gene action for these traits indicated their usefulness in hybrid programs of subtropical maize.

In this paper, we reconsider the issue of the relative magnitude of the optimal capacity of a congestible facility, under optimal congestion tolling, as compared to the second-best capacity with less than optimal tolling, when such tolling is the result of distributional objectives. We show that the previous literature does not address this issue, because it is always based on formulations of the problem that, at least implicitly, assume that the high cost of tolling is the reason for less than optimal tolls. We present a formulation of the problem adequate to distributional objectives. In this formulation, second-best tolls and capacities are chosen together, and characteristic outcomes show that the extant analyses do not apply to cases with distributional objectives.

Crop interference with weed growth is a fundamental method of nonchemical weed control. Crop interference, entailing weed suppression, should be distinguished from crop tolerance of weeds, i.e., relatively small yield loss due to the presence of weeds. Tolerance is less desirable than interference in that it may lead to increases in weed seed populations that can cause future yield losses. Ideally, interference should occur as early as possible in growth to prevent resource consumption by weeds. A path analysis of crop-weed interference is presented. The model can be used to estimate the relative magnitude of early vs. later crop interference with weed growth, and to identify crop traits that contribute to the interference with weed growth. Such analysis can identify crop varieties that show strong early interference with weed growth, and traits associated with strong early interference. For illustrative purposes, the model is applied to characterize differences among soybean varieties in interference with common cocklebur. Weed control by crop interference could be enhanced by crop breeding and management. However, several benefits and costs of interference should be evaluated before undertaking such approaches. First, the degree to which crop interference can substitute for other forms of weed control must be determined. Second, yield costs associated with interference should be measured; these may occur in crop varieties that interfere strongly with weeds, particularly when water, temperature, and mineral nutrients are limiting. A more mechanistic understanding of crop interference is needed so that interference can be enhanced through crop breeding and management while minimizing yield costs.

1. The effect of extirpation of the optic ganglion on the ERG and on electrical oscillations recorded from the compound eye was determined. 2. Extirpation of the optic ganglion prevents the occurrence of oscillations, and it is concluded that they originate in the ganglion. 3. Extirpation of the optic ganglion changes the wave form of the ERG. The sharpness of the b-wave is decreased, the relative magnitude of the c-wave is increased, and the d-wave is obliterated. These changes can be explained by assuming that the ERG is the algebraic sum of two potential changes, one in the compound eye, and another, of opposite sign in the ganglion. This assumption is supported by data from a number of experiments in which the electrode positions were varied. 4. The explanation of the present data (which indicates two sites of origin of the ERG) is similar to the three-component theory which accounts for the complex wave form of the vertebrate ERG.

A method to study the kinetics of protein foam decay has been evaluated. The method involves monitoring of pressure change as a function of time in a closed system containing a foam, which then is converted to decay of the interfacial area of the foam as a function of time. The method provides a means to estimate the initial surface area of foams. Studies with bovine serum albumin (BSA) foam, as a model, revealed that the instability of protein foams generally follows either monophasic or biphasic first-order kinetics. Two microscopic processes, namely, gravitational drainage and interbubble gas diffusion, are fundamentally responsible for protein foam instability. The relative magnitude of the rate constants of these two processes is affected by environmental factors such as temperature, pH, and the presence of reducing agents.

Hatchery-reared fingerlings of striped bass Morone saxatilis were tagged, stocked, and recovered in the Patuxent River, Maryland, to estimate their survival and abundance relative to wild young of the year and to compare the costs and benefits of stocking phase-I (35–50 mm, total length) and phase-II (150–200 mm) fish. About 100,000 phase-I fingerlings were tagged and released each year during midsummer 1988 and 1989. Both tagged and untagged (wild) young of the year were recovered by alongshore seining in the river through 80 d poststocking. Mortality rates of wild and hatchery-reared young of the year were not significantly different-about 3%/d. Wild young of the year were more abundant in 1989 than in 1988. In 1988, phase-I fingerlings composed 56% of all young-of-the-year striped bass in the river. In 1989 wild young-of-the-year striped bass outnumbered hatchery-reared fingerlings by about 11 to 1. Whether phase-I or phase-II stocking was more cost-effective depended on the relative magnitude...

We develop a mathematical model to delimit the role of natural selection in maintaining nuclear and cytoplasmic polymorphisms in selfing populations. We provide explicit time-dependent solutions for joint cytonuclear frequencies under any combination of constant fertility, viability, and gametic selection and exact analytical conditions for the maintenance of polymorphisms under joint cytonuclear selection. The equilibrium structure is determined by the relative magnitude of echo fitnesses, defined as the rate at which individuals survive and produce offspring with their own genotype. Both nuclear and cytoplasmic polymorphisms can be maintained under biologically meaningful conditions, although the majority of the parameter combinations will lead to fixation. The theoretical framework developed here should be very useful in formally dissecting the form and strength of selection on cytonuclear genotypes in populations with negligible levels of outcrossing.

Background: Head-up tilt testing (HUTT) is a well-established diagnostic tool in patients with suspected vaso-vagal syncope (VVS). However, it is time-consuming and requires special equipment. Thus, identification of simple parameters which could predict the outcome of HUTT could simplify diagnostic steps by obviating the need for HUTT. Aim: To assess which symptoms associated with spontaneous syncope or other details from medical history can predict HUTT results. Methods: The study group consisted of 202 unselected patients (69 males, mean age 43 ± 20 years) who were admitted to our syncope unit for HUTT due to suspected VVS. They filled in a detailed questionnaire including 34 standard questions concerning medical history as well as circumstances and symptoms associated with syncopal episodes. Patients were tilted to 70° for 45 minutes or the test was stopped earlier if syncope occurred. A stepwise multiple logistic regression was performed in order to assess which parameters independently predicted the results of HUTT. A point-score was developed by assigning ±1, ±2, or ±3 points to each of the factors based on the relative magnitude of the estimated regression coefficient. The points were then summed and a diagnostic threshold chosen using plots of sensitivity and specificity curves. Results: Syncope was induced by HUTT in 67 (33%) patients. In the whole study group, a point-score identified patients with positive HUTT with a sensitivity of 87.9%, and specificity of 36.3%. When the analysis was confined to the subgroup with >4 syncopal episodes in the past, the sensitivity of a point-score was 94.4%, and specificity—60%, and in the subgroup with >2 syncopal episodes occurring within 1 month preceding HUTT, sensitivity values reached 88.2% at the specificity level of 90.9%. Conclusions: In patients with frequent syncopal episodes, especially clustered shortly before performing HUTT, in whom symptoms are very suggestive of VVS, a simple point-score system based on medical history accurately predicts HUTT results. Thus, HUTT may not be necessary for establishing diagnosis in this group of patients.

Publisher Summary Gene regulation can be studied using a large number of molecular biological techniques. However, only in situ hybridization (ISH) histochemistry permits the precise regional and cellular localization of gene expression in a particular tissue, especially in morphologically and functionally complex tissues such as the nervous system. Because changes in gene transcription, indicated by altered levels of mRNA encoding specific peptides or proteins, are physiologically relevant markers of cellular activity, the ability to perceive these changes and to determine their magnitude accurately is of great importance. When comparing levels of mRNA in different anatomical locations or developmental stages, or in response to pharmacological and physiological/surgical manipulations, or to pathology, quantitative analysis of ISH not only allows the identification of localized changes, but also measurement of their relative magnitude. Many of the techniques used in the quantitative analysis of ISH are derived from those devised for neurotransmitter-receptor autoradiography. An understanding of how X-ray films and nuclear emulsions respond to radioactivity is also useful in the design and analysis of ISH experiments. This chapter reviews the theoretical considerations that should be observed to allow the accurate and meaningful quantification of ISH, and presents practical advice and instructions for this analysis. This chapter focuses on convenient computerized methods for the quantification of ISH results, as these are now very commonly used and are usually more efficient than manual methods.

In vivo electrophysiological recordings in the sea catfish, Arius felis, showed that the magnitude of the integrated facial taste responses to binary mixtures of amino acids was predictable with knowledge obtained from previous cross-adaptation studies of the relative independence of the respective binding sites of the component stimuli. Each component from which equal aliquots were drawn to form the mixtures was adjusted in concentration to provide for approximately equal response magnitudes. The magnitude of the taste responses to binary mixtures whose component amino acids showed minimal cross-adaptation was significantly greater than that to binary mixtures whose components exhibited considerable cross-reactivity. There was no evidence for mixture suppression. The relative magnitude of the taste responses in the sea catfish to stimulus mixtures is similar to that previously reported for olfactory receptor responses in the freshwater channel catfish and chorda tympani taste responses in the hamster.

We have previously demonstrated that basolateral addition of the gastric H-K-adenosinetriphosphatase (H-K-ATPase) inhibitor Sch-28080 (10 microM) profoundly reduced net total CO2 flux (JtCO2) in the inner stripe of the outer medullary collecting duct (OMCDi) of K-replete rabbits. In the present studies, we first addressed whether the inhibitory effect of Sch-28080 is dependent on the side of the membrane to which it is added. Second, we reassessed the relative magnitude of contribution of H-K-ATPase. Third, we formally tested whether a bafilomycin-A1 (BAF)-sensitive H-ATPase also contributes to luminal acidification in the OMCDi under K-replete dietary conditions. We found that luminal addition of the structurally and functionally dissimilar gastric H-K-ATPase inhibitor A80915A (10 microM) profoundly reduced JtCO2 while transepithelial voltage (VT) was unchanged. This degree of inhibition was statistically indistinguishable from our previous results when Sch-28080 was applied basolaterally. Inhibition of JtCO2 by the less membrane-permeable N-methyl cation of Sch-28080, H224/25, was significant when applied luminally but was not significant when applied basolaterally. VT was not significantly affected by either the luminal or basolateral addition of H224/25. To evaluate the possible contribution of an H-ATPase, the effect of both 5.0 nM and 10.0 nM luminal BAF on JtCO2 and VT was examined. At 5.0 nM, BAF significantly inhibited JtCO2). However, this observation was significantly less (P < 0.05) than the inhibition observed with 10 microM A80915A. No additional inhibition was observed by increasing the concentration of BAF to 10.0 nM.(ABSTRACT TRUNCATED AT 250 WORDS)

This project had three major goals. The first was to assist the Oregon Department of Fish and Wildlife with predation indexing as part of an effort to estimate the relative magnitude of juvenile salmonid losses to northern squawfish Ptychocheilus oregonensis in reservoirs throughout the Columbia River Basin. The second goal was to evaluate the northern squawfish control program and test critical assumptions about mid-reservoir predation processes. The final goal was to determine mechanisms underlying northern squawfish recruitment and factors affecting year-class strength.

Territory owners often respond less aggressively towards intruding neighbors than towards intruding floaters, an observation termed “the dear enemy phenomenon.” Comparisons of territory owners' responses to intruding neighbors versus their responses to intruding floaters usually have been made for owners of multi-purpose and/or breeding territories. Here, I describe responses of female northern harriers Circus cyaneus (owners) on winter feeding territories towards three types of intruders (female neighbors, female floaters, and male floaters) and show that the dear enemy phenomenon does not occur. Owners' responses towards neighbors were more intense (mostly flights rather than calls) than responses towards female floaters, which in turn were more intense than responses towards male floaters. The greater intensity of owners' responses towards neighbors compared to owners' responses towards male and female floaters may be related to differences in the threat posed by each of the three intruder types in terms of fighting ability (RHP) and potential losses from intrusion. Hence, whether owners respond more aggressively towards neighbors or floaters, and whether the dear enemy phenomenon is observed, may depend upon the relative magnitude of threat presented by neighbors and floaters to owners in terms of fighting ability and potential losses from intrusion.

Much previous research has reported increased token‐to‐token variability in children relative to adults, but the sources and implications of this variability remain matters of debate. Recently, functional data analysis has been used as a tool to gain greater insight into the nature of variability in children’s and adults’ speech data. In FDA, signals are time‐normalized using a smooth function of time. The magnitude of the time‐warping function provides an index of phasing (temporal) variability, and a separate index of amplitude variability is calculated from the time‐normalized signal. Here, oral airflow data are analyzed from 5‐year‐olds, 10‐year‐olds, and adult women producing laryngeal and oral fricatives (/h, s, z/). The preliminary FDA results show that children generally have higher temporal and amplitude indices than adults, suggesting greater variability both in gestural timing and magnitude. However, individual patterns are evident in the relative magnitude of the two indices, and in which consonants show the highest values. The time‐varying patterns of flow variability over time in /s/ are also explored as a method of inferring relative variability among laryngeal and oral gestures. [Work supported by NIH and CNPq, Brazil.]

Nachman and Heller recently suggested that previous estimates of the relative magnitude of fluctuating asymmetry in morphological characters have been biased because non-linear relationships between asymmetry and size have not been considered. This suggestion cannot generally be very important because (1) inclusion of a non-linear size term in regression models relating fitness components to asymmetry does not change the general conclusion that asymmetry is an important predictor of fitness components, and (2) experimental studies uncoupling the relationship between asymmetry and size have generally found significant effects of asymmetry independent of body size on mating success and locomotion.