The present taxonomical study was undertaken with the view of obtaining additional information on the occurrence and distribution of algae in Kentucky. The investigation was begun in February 1934 under the direction of Dr. H.L. Stephens of the Western Kentucky State Teachers College. During the next three months 110 collections of algae were made and analyzed.

A large degree of variation in fiber tracheid length, wood specific gravity, and time of apical bud formation existed within two populations of Liquidambar styraciflua L. from south central Kentucky. The variation exhibited by these populations may be attributed to the self-sterility of Liquidambar and the variable environment of south central Kentucky. Variation of fiber tracheid length and wood specific gravity within the two populations was significant. Fiber tracheid length was dependent on temperature and photoperiod while wood specific gravity was primarily dependent on temperature. A significant level of variation was also evident between the two populations regarding tracheid length. Phenologically the populations shod a very large amount of variation in the total number of hours darkness required for bud formation. A pattern of decreasing photoperiods resulting in a decrease in the total number of hours darkness required for bud formation is also suggested. Limited studies revealed a period of cold temperature is required for bud bursting.

A circadian rhythm in eye sensitivity to light has been previously reported for Leucophaea maderae. Temporal changes in eye cell morphology that could be correlated with those changes in eye sensitivity to light were examined. Rhabdom area, screening pigment organization and palisade layer area about the rhabdom were the parameters measured to detect structural change through time. Measurements of those parameters from tissue samples obtained from the anterior one-third of compound eyes surgically removed at midday, light offset, midnight and light onset from roaches entrained to a 12-h light / 12-h dark photoperiodic cycle were used to assess the daily pattern of morphological changes. Eyes were removed at subjective midday and subjective midnight from roaches free-running under constant conditions of temperature and darkness to detect circadian changes. All roaches received food and water ad libitum. Tissue samples were fixed, embedded, sectioned and the sections were examined and photographed using a Zeiss transmission electron microscope to test for time-related morphological differences. The extent of pigment organization was determined by counting the number of pigment granules found within a 10µm diameter circle centered about the rhabdom. The rhabdom area and the palisade layer area were determined by the Jandel PC3-D computer program. The rhabdom area did not vary throughout the day. The organization of screening pigment granules and the palisade layer area did vary on a daily basis. In animals maintained under constant environmental conditions the rhythm of the organization of the pigment granules did not persist. In contrast, temporal changes in the palisade layer area did persist for three cycles with a pattern similar to that in roaches held under LD12:12 and thus could be considered a circadian rhythm controlled by a pacemaker.

Tailwater fishes of the Green, Barren, and Rough River Lakes, Kentucky, were sampled in the fall of 1978, spring 1979, and summer 1979. Fish per acre estimates were greatest in the fall and least in the spring, while standing crop estimates were similar in the fall and spring but markedly lower in the summer. Cyprinidae was the predominant family represented in the entire study. Rough species comprised the greatest component of biomass in each tailwater, while forage and/or game fish represented the majority of individuals. Barren River tailwater fishes exhibited the greatest average standing crop estimates, while the greatest variety of species was observed in the Green River tailwater. Habitat differences were concluded to be responsible for the observed differences between the Green and Barren River tailwaters. The Rough River tailwater included a pool six miles in length and was considered an atypical tailwater. Standing crop estimates were highest in the fall on Green and Rough River tailwaters and in the spring on Barren River tailwater. Numerically, the most abundant species in the Green River tailwater were the bluntnose minnow and white crappie. Longear sunfish and spotfin shiner predominated in the Barren, while white crappie and gizzard shad were most abundant in the Rough. A decrease in average standing crop estimates was observed between the most upstream and downstream stations on Rough River tailwater, but, due to similarity of habitat between the stations, no explanation was available. Rainbow trout were generally found in close proximity to stocking points for each tailwater.

Candida albicans is a pathogenic yeast often encountered in the medical laboratory. A survey taken by mail of 110 Kentucky hospital and clinical laboratories demonstrated that the germ tube test is the most frequently used method for the identification of this organism. Earlier workers have found that this technique does not distinguish between C. albicans and C. stellatoidea. Various modifications of the germ tube test that could possibly be used in the differentiation of these two taxa were investigated. Parameters examined included the effects of oxygen tension, CO2, increased temperature, serum dilution, glucose concentration, and a synthetic medium upon germ tube formation. The results indicated that the germ tube test cannot be satisfactorily used to differentiate these two organisms. An evaluation of the use of cultural characteristics on commonly used media and agglutination by C. albicans and antiserum demonstrated that these cannot be used to dependably identify C. albicans. The response of C. albicans and C. stellatoidea to various antimycotic agents and to other microorganisms were compared and the pathogenicity of C. albicans and C. stellatoidea was discussed.

Goldfish of the wild-strain variety, Carassius auratus, were used in the study of caudal fin regeneration. The purpose of this study was to determine the effects of denervation on caudal fin regeneration. In the experimental groups, it was evident that denervation did not prevent regeneration, although it was significantly reduced. Statistical analysis using the Duncan's Multiple Range Test showed a highly significant difference (0.01 % level) in the mean percentage of regeneration between the denerved group and the other three groups. Caudal fins having proximal amputations regenerated at a faster rate than those having distal amputations, producing a higher mean percentage of regeneration. The results of this study indicated that denervation did not prevent regeneration of the caudal fin in the goldfish and suggested the possibility that this process might be controlled by a combination of several factors.

Immature Orconectes rusticus rusticus (Girard) were collected from Doe Run, Meade Co., Ky. on January 16, June 1, and October 21, 1972, for the purpose of examining the effects of three different temperatures (14C, 18C, and 22C) and three different photo, eriods (6L:18D, 15L:9D, and 24LL) on seasonal molting patterns. For each seasonal experiment, 144 crayfish were placed in 3 x 3 experimental units and maintained for a 90-day period. In Experiment 1 (January 18-April 18), 98 molts were attempted with 98% of the molts being successfully completed. Arrangement of these molts within the separate treatments of this experiment indicated that there was a highly significant linear relationship between increasing temperature and increasing populational molt frequency as well as a significant linear relationship between increasing length of photophase and increasing molt frequency. No crayfish molted during the first 15 days of this experiment and animals in the warmest temperature molted an average of 17.06 days earlier than those in the coldest temperature. Crayfish in Experiment 3 (October 23-January 20) molted in similar patterns with respect to temperature and photoperiod but molted in fewer numbers (43 molts attempted) than those in Experiment 1. Animals molted immediately upon initiation of this experiment and crayfish kept at 22C molted in highest numbers toward the end of the experiment. Ninety five percent of the molts attempted by these crayfish were successful. Crayfish in Experiment 2 (June 3-September 1) molted in the highest total number of all of the experiments (144 molts attempted) but with the lowest percentage of molts successfully completed (30%). Although molt mortalities were high in this experiment, they appeared to occur independent of temperature and photoperiod treatments. Crayfish molt frequency showed a significant quadratic relationship with temperature but no relationship between successful or unsuccessful molt frequencies and increasing photophase was noted. Two auxiliary experiments were also completed in which 46 adults collected in June were tested for molt frequency in three different light intensities (10, 40, and 110 f.c.) and 48 adults collected in October were compared directly with the molt frequency of 48 immatures. In both experiments, adults molted in fewer numbers than immatures tested at the same time, the greatest difference being found in the October experiment (3 adult molts vs. 19 molts by immatures). No relationship between light intensity and molt frequency was found. No sex differences or interactions between treatments were found in any of these experiments. Discussion of these results centered around the characterization of a proposed molt control mechanism for this population of O. r. rusticus. Such a mechanism was characterized as being most sensitive, on a populational level, to temperature and photoperiod during the spring and fall seasons and less sensitive or insensitive to these same signals during the summer. The linear aspect of the relationship between treatments and molt frequencies in Experiments 1 and 3 was interpreted as an indication that either this molt control mechanism is less sensitive to environmental signals than the one previously characterized for more northern populations of O. virilis or that more individual variation exists in this population of O. r. rusticus. The large number of mortalities that occurred in Experiment 2 was discussed but not explained.

This study was undertaken in order to identify the approximate times of recruitment of the senses of vision, mechanoreception and chemoreception into the feeding behavior of the fathead minnow, Pimephales promelas, during the first 15 days of life. Larvae were reared on diets of live or freshly killed brine shrimp nauplii and their feeding activity observed daily under light and dark conditions. On every third day during the feeding trials, the larvae were reverse-fed the type of food upon which they were reared. The first evidence of feeding occurred on Day 3, when larvae conditioned on dead food ingested live food in the dark. Larvae in all groups tested exhibited some degree of feeding on Day 4. Larvae tested under dark conditions exhibited maximum feeding capabilities earlier than their counterparts tested in the light. Larvae showed an earlier ability to locate and ingest live prey over dead prey in both light and dark conditions suggesting that the sense of mechanoreception was functional in the larvae at the time of commencement of feeding. Although the sense of vision is functional at or soon after hatching, there appeared to be a lack of coordination or integration between the eyes and the lateral line system. The sense of chemoreception appeared to be the last major sense to become fully functional. Locomotor activity increased with age under all test conditions in conjunction with the developing sense organs.

Various aspects of the biology of the southern redbelly dace, Chrosomus erythrogaster Rafinesgue, were intensively studied on a population in Ivy Creek, Warren County, Kentucky from 1971 to 1972. Reproduction in the southern redbellv dace occurred from May through June. Older, sexually mature individuals spawned early in the reproductive period while those in their first year of life spawned during late June. The number of eggs shed annually ranged from 140 to 681 with an average of 385. A positive correlation existed between the number of eggs shed and standard length. Differences between the sexes of the species were marked and included intensity and distribution of pigmentation, breeding tubercle development and length and shape of the pectoral fins. Males were most distinctive, having prominent scarlet ventral surfaces and breeding tubercles on the head and fins during the reproductive period. Males had more distinctive coloration as well as longer and broader pectoral fins. While more females than males were collected during this study, no significant deviation from the theoretical 1:1 sex ratio was observed. The normal life span of the southern redbelly dace was about two years with a few individuals living into the autumn of their third year (26-30 months). Males disappeared from the populations slightly earlier than females. Age Group 0, or individuals in their first year, constituted the dominant age group. Growth in length was greatest during the first year of life while growth in weight was greatest during the second year and that portion of the third year survived. No statistically significant deviation was observed between the theoretical cubic response of growth in weight to length and that observed among the specimens in Ivy Creek. Coefficient of Condition values were greater for males than females when gonad weight was excluded. Converse results were observed when the gonads of both sexes were included in the condition determinations. Seasonally, condition coefficients for both sexes combined were greatest during the spawning season, lower during the warm-water months and lowest during the cold-water months. Food habits were generally non-specific with combinations of algal forms, (filamentous chlorophytes and diatoms) and organic detritus constituting the major dietary components. Aquatic insects were commonly found in the guts of larger specimens. Southern redbelly dace existed as a part of a larger assemblage of fish species and because of their food habits and reproductive behavior co-existed successfully. Parasitism of the species was not obvious.

Southern Bean Mosaic Virus (SBMV) codes for a large polyprotein which is subsequently cleaved into smaller functional proteins. A virally encoded protease is suspected of mediating the cleavages. SBMV, picornaviruses and picornavirus-like viruses appear to have similar genomic organizations, which would place the protease region of the genome between the VPg and RNA dependen,, RNA polymerase regions. Protein sequence comparisons revealed homology between SBMV putative protease and the known proteases from foot and mouth disease virus, encephlamyocarditis virus, poliovirus, and cowpea mosaic virus. Experimental evidence provides little information on the exact location of the protease; however, protein sequence analysis suggests that the protease is indeed located between the VPg and RNA polymerase regions of SBMV. Comparisons of known cleavages sites to SBMV suggests that the QS amino acid pairs, at postions 539-540 and 664-665, are the most likely site for cleavage. The QS pair is present on the surface, in a region with high flexibility, which is in a turn. This evidence, although circumstantial, is supported by the deletion of the C-terminal end of the protein.