Development of rainbow trout microsatellite markers from repeat enriched libraries.

The efficiency of developing polymorphic microsatellite markers from 2 repeat enriched libraries was evaluated. Thirty-six polymorphic microsatellite markers were developed for rainbow trout, 27 of which were informative in a mapping family. The ability of each marker to amplify genomic DNA from other salmonids was also observed.

Haptic estimates of discordant visual-haptic size vary developmentally.

In two size-conflict experiments, children viewed various squares through a reducing (1/2) lens while manually grasping them through a hand-concealing cloth. Then, using either vision or touch, they selected a match from a set of comparison squares. Forty 6-, 9-, and 12-year-olds participated in Experiment 1. Vision dominated the visual estimates of all three age groups; however, for the haptic estimates, the dominant modality varied developmentally: Vision dominated the 6-year-olds' haptic estimates, whereas neither modality dominated the 9-year-olds' haptic estimates, and touch dominated the 12-year-olds' haptic estimates. In Experiment 2, 24 six-year-olds were tested, as in Experiment 1; however, half of them were shown the size-distorting effects of the lens just prior to testing. Although this reduced the visual dominance of their haptic estimates, the effect was weak and short-lived. The haptic dominance seen in the data of the 12-year-olds was conspicuously absent.

Visualizing the perisaccadic shift of spatiotopic coordinates.

A point light source flickering on and off during a horizontal saccade projects a horizontal array onto the retina. The apparent visual direction of the tail end of the perceived (phantom) array reflects the amount of perisaccadic shift of spatiotopic coordinates that has been completed by the end of the saccade. Four men, saccading 8 degrees to the right across a flashing light, judged the horizontal visual direction of the left (tail) end of the phantom array relative to the left end of a standard 8 degrees array that had projected an image onto the retina before the saccade began. On average, the left ends appeared to be aligned when the last flash in the phantom array was imaged on the retina 7.4 degrees to the right of the image of the left end of the standard array. This result implies that the shift of spatiotopic coordinates is virtually complete by the end of the saccade.

Germinability of Teliospores of Tilletia indica after Hot Water and Sodium Hypochlorite Treatments.

Hot water and sodium hypochlorite (NaOCl) were evaluated to eradicate teliospores of the Karnal bunt fungus, Tilletia indica, for the purpose of decontaminating grain storage and handling equipment. The germinability of free teliospores and teliospores within the sori of infected wheat was assessed. Temperatures of 25, 60, and 80°C, NaOCl concentrations (wt/vol, pH 11.5) of 0, 0.53, and 1.60%, and immersion periods of 1, 5, 15, and 30 min were evaluated. In other tests, the influence of pH on NaOCl potency and of a delay between treatment and water rinsing were evaluated. Immersion at 80°C in water alone or with NaOCl killed both free teliospores and those within the sori of infected seeds within 1 min. NaOCl at 1.60% at 25°C killed teliospores suspended in water within 15 min, but some teliospores inside sori survived 30 min of this treatment. NaOCl adjusted to pH 8 before use was superior to NaOCl at pH 11.5. An application of 1.60% NaOCl at 25°C for 5 min followed by a 10-min delay before the seeds were rinsed in fresh water killed free teliospores but not all teliospores within sori. This treatment was more effective than the 5-min treatment alone but inferior to the 15-min treatment with NaOCl at a concentration of 1.60%. Because teliospores within the sori of infected seeds are partially protected and much more resistant to NaOCl, we recommend the removal and disposal of seeds from equipment before the treatments are applied. NaOCl radically altered the appearance of the teliospores, leaving a persistent visual indication that they had been treated, while hot water treatment alone did not. Therefore, it is beneficial to add NaOCl to hot water, although the improvement in the sporicidal efficacy was often small.

Touch dominates haptic estimates of discordant visual-haptic size.

Observers (72 college students) estimated the size of plastic squares that they held in their fingers and simultaneously viewed through a reducing lens that halved the squares' visual size. The squares were grasped from below through a cloth that prevented direct sight of the hand. Each estimate was a match selected later, either haptically or visually, from a set of comparison squares. Vision dominated the visual estimates and touch dominated the haptic estimates, whether or not the observers knew in advance which type of estimate they would be asked to make. Neither modality inherently dominates perceived size.

Genetics of size and growth rate through sexual maturity in freshwater-reared coho salmon (Oncorhynchus kisutch).

Genetic parameters of size through sexual maturity have been relatively unexplored for Pacific salmon. In this study, individually tagged coho salmon were raised in freshwater, and the heritabilities of size and growth rate were estimated at several intervals between 13 and 24 months of age (spawning). Heritability estimates for size were moderate to high from 13 to 19 months of age, ranging from 0.36 to 0.50, and lower from 21 months to spawning at 24 months, ranging from 0.17 to 0.32. Heritabilities of specific growth rates estimated over 3-month intervals were moderate from 16 to 21 months of age, ranging from 0.21 to 0.34. Genetic and phenotypic correlations between sizes measured at different ages were moderate to high, ranging from about 0.7 to 1.0. Correlations between growth rate and size indicated that the larger fish were the fastest growing between 16 and 19 months of age and were slower growing between 19 and 21 months of age.

Timing the shift in retinal local signs that accompanies a saccadic eye movement.

The phantom array was used to probe the time course of the shift in retinal local signs that accompanies a saccadic eye movement. The phantom array materializes when one saccades in the dark across a point light source blinking 120 times per second. One sees a stationary array of flashes--the first materializes discretely near the intended endpoint of the saccade, and subsequent flashes materialize progressively closer to the actual position of the blinking light. Four trained observers indicated the perceived location, relative to the phantom array, of a 1-msec marker flash (M) produced by two LEDs (light-emitting diodes) that vertically bracketed the blinking light. The marker was seen as spatially coincident with the first flash when it flashed 80 to 0 msec before the saccade, and was seen as spatially coincident with either the first flash or the actual position of the blinking light when it flashed more than 80 msec before the saccade, indicating, respectively, that the shift is presaccadic and rather abrupt.

Genetic Consequences of Blocking Polar Body I with Cytochalasin B in Fertilized Eggs of the Pacific Oyster, Crassostrea gigas: I. Ploidy of Resultant Embryos.

The effect of blocking polar body I (PB1) with cytochalasin B (CB) on the ploidy of embryos was studied in the Pacific oyster, Crassostrea gigas. To block the release of PB1, fertilized eggs were treated with CB (1.0 µg/ml) for 15 min beginning at 5 min post-fertilization at 25°C. The CB treatment and its control were repeated in three crosses. Ploidy of 8-h-old embryos was determined with karyological analysis. In control groups, the majority of the cells (89.3%) had a diploid number of 20 chromosomes, although spontaneous haploids (0.7%), triploids (1.3%) and aneuploids (8.7%) were also encountered. In CB-treated groups, only 4.5% of the cells remained as diploid, and the majority were either triploid (15.6%), tetraploid (19.4%) or aneuploid (57.6%). Despite variation among the three crosses, contingency Chi-square analysis showed that the occurrence of triploids, tetraploids and aneuploids had a significant (P = 0.0001) dependence on the CB treatment. The majority of the aneuploids fell into two groups containing either 23-25 or 35-37 chromosomes. The production of triploids, tetraploids and aneuploids in specific distributions suggests that blocking PB1 complicates subsequent chromosome segregation.

Genetic Consequences of Blocking Polar Body I with Cytochalasin B in Fertilized Eggs of the Pacific Oyster, Crassostrea gigas: II. Segregation of Chromosomes.

The effect of blocking polar body I (PB1) with cytochalasin B (CB) on subsequent chromosome segregation was studied in fertilized eggs of the Pacific oyster, Crassostrea gigas. To block the release of PB1, fertilized eggs were treated with CB (1.0 µg/ml) for 15 min beginning at 5 min post-fertilization at 25{deg}C. Chromosome segregation in both control and CB-treated eggs was analyzed with an acetic orcein stain. In untreated eggs, ten maternal tetrad chromosomes went through meiosis I and II, and released two polar bodies, reaching a haploid number of 10 chromatids. In CB-treated eggs, meiosis I proceeded normally and produced two groups of dyads, ten in each group. However, blocking PB1 dramatically changed chromosome segregation in meiosis II. In the majority of the treated eggs (68%), the two groups of dyads from meiosis I entered meiosis II through a "tripolar segregation", although two other types of segregation, namely "united bipolar" (7%) and "separated bipolar" (12%) were also observed. After anaphase II, chromatids at the peripheral pole were released as polar body II (PB2). The release of two sets of chromatids as PB2 through either a united bipolar or a separated bipolar segregation resulted in the formation of meiosis I triploids (14%). The release of one set of chromatids as PB2 from an unmixed tripolar or a separated bipolar segregation formed meiosis I tetraploids (20%). Aneuploids (56%) were produced, primarily when the two groups of dyads from meiosis I united or overlapped before entering the tripolar segregation.

Development of visual attention: a stereoscopic view.

Five-year-olds, 8-year-olds, and adults (20 each) tachistoscopically viewed random-dot stereograms containing either uniform depth or an elevated disk whose perimeter fell 1.5 degrees, 2.5 degrees, or 4 degrees beyond fixation. When subjects were forewarned as to the size of the disk to look for (precued trials), signal detection improved (d' increased) for all three groups, and 5-year-olds improved the most. Without forewarning (self-cued trials), the 5-year-olds performed more poorly than the other two groups, which performed alike. Although young children are able to allocate their visual attention selectively, they do not appear to deploy it as quickly or as effectively as their elders when the focus of attention is theirs to choose.

Hormonal Regulation, and Intracellular Localization of a 33-kD Cationic Peroxidase in Excised Cucumber Cotyledons.

Ethylene enhanced chlorosis and levels of 33-kilodalton cationic peroxidase (33-CPO) in excised cucumber (Cucumis sativus L. cv ;Poinsett 76') cotyledons. Compared to other hormones, such as kinetin, indoleacetic acid, gibberellic acid, and abscisic acid, ethylene was the only effective promoter of 33-CPO synthesis. The hypothesis that peroxidase plays a role in chlorophyll degradation was tested by comparing levels of 33-CPO in cotyledons treated with compounds thought to either retard (kinetin, indoleacetic acid and gibberellic acid), or promote (abscisic acid and methyl jasmonate [MJ]) senescence. It was concluded that 33-CPO did not play a role in senescence since no direct correlation between chlorophyll content and 33-CPO was observed. MJ was as effective as ethylene in inducing senescence. However, ethylene did not appear to be involved in the action of MJ. Using immunocytochemistry, 33-CPO was found to be located primarily around starch grains and near the plasmalemma. High levels of 33-CPO were also found in cells destined to be vascular tissue.

Effects of impaired hearing and favorable vs. unfavorable personal feedback on negative emotional reactions.

Eighty college females listened to one of four taped conversations, which they were led to believe were personality evaluations of themselves. The content of the evaluations varied in feedback, which described either strengths or weaknesses in adjustment, and in form, in that each recording was either completely intelligible or partially unintelligible to simulate normal and impaired hearing, respectively. The emotional reactivity of the subjects was assessed with several psychometric instruments once before and again immediately after they listened to the tapes; the pre/post difference scores reflected the negative emotions elicited by the experimental manipulations. Factorial analyses of variance yielded significant main effects for each variable, hearing and feedback, but no interaction. Anxiety, depression, negative attribution, and paranoid reactions were increased by both impaired hearing and unfavorable feedback, and their adverse effects were independent and additive.

Changes in the hemoglobin system of the coho salmon Oncorhynchus kisutch during smoltification and triiodothyronine and propylthiouracil treatment.

Three electrophoretically separable forms of blood hemoglobin were found in fry of coho salmon (Oncorhynchus kisutch). Ten hemoglobin forms were found in juvenile and adult salmon. Treatment of yearling salmon with triiodothyronine (T3) at 12 ppm in the diet accelerated the increase in concentration of adult forms of hemoglobin, while treatment with T3 at 4 ppm had no effect. Dietary propylthiouracil (1.5 or 5 mg/g) reduced the increases in adult forms of hemoglobin during smoltification. These results implicate thyroid hormones in the expression of adult forms of hemoglobin during the parr to smolt transformation of juvenile salmon.