Charles E. Schmidt College of Science

Public lecture series. Florida is at the forefront of many of the national and global pressures that can result in degraded water quality. Among these are nutrient, plastics, and other pollution into watersheds and the oceans, ocean warming and acidification, changes in land use associated with increased runoff and environmental damage, extreme climate events, sea level rise and saltwater intrusion, harmful algal blooms and other ecotoxicity in waters, seagrass and coral die offs, and more.

This study was a partial replication of one previously
reported by Nash and Michels (1966). The purpose was to investigate
perceptual form discrimination behavior of young
squirrel monkeys as affected by contextual variables of the
stimulus. The variables examined were Redundancy, Position
and, of the form itself, Complexity. In addition, a sequential
method of testing and recording was compared with
the conventional 50-trial block procedure. Two 17 month old monkeys were tested on eight twochoice
problems in a Purdue General Test Apparatus. The
problems each consisted of two slides on which pairs of
random shapes were presented. The shapes within each pair
of slides were held constant on the parameters investigated.
One slide was designated as the positive stimulus and presented
in either the right or left position in random order. The number of correct responses for the 50-trial
blocks, as examined by an analysis of variance, failed to
reach statistical significance for any of the variables
investigated. However, graphic inspection of the data
suggests general agreement with the findings of Nash and
Michels (1966). In comparing the two methods of testing,
the sequential test of performance (STOP) was equally as
effective as the conventional method and could have provided
a substantial savings in test time. Comparison of
scores obtained by the two procedures shows good correlation. Although no strong conclusions can be drawn from the
data, they do lead to the speculation that there is a relationship
between effect and extent of redundancy, and
that failure of S to make a correct response in the test
situation may be the result of cue sampling rather than a
failure to discriminate.

In the present experiment possible developmental differences in the
timing of organization in children's free recall were examined. It was
hypothesized that children who organize information at input would show
a smaller decrement in recall as a result of delayed testing with
related than with unrelated materials. If the categorical similarity
among items is discovered at input, the resulting organizational scheme(s)
would make the individual items more resistant to forgetting over time.
However, since no organizational scheme could be imposed upon unrelated
items, many items would be lost as a result of delayed testing. This
pattern of data was predicted only for junior high students and not
for second and third graders. However, contrary to expectation, both
the younger and older groups of subjects showed this pattern, indicating
that children of both age groups organize categorically related
information at input. The possibility of a semantic facilitative effect
for the younger subjects was discussed.

Brain glutamic acid decarboxylase 65 (GAD65) catalyzes the rate-limiting step in the biosynthesis of the major inhibitory neurotransmitter-amino butyric acid (GABA) from the substrate L-glutamic acid. Severe lapse in GABA neurotransmission is one of the etiologies documented in the manifestation of certain neurodegenerative diseases such as epilepsy, Parkinson's disease, Huntington's disease etc. Because GAD65 synthesizes GABA, any modulation of GAD65, therefore, has direct implications on the quanta of GABA released at the synapse. Hence, the major objective of this study was to focus on the regulation of GAD65, with special emphasis on investigating the proteolytic cleavage of fGAD65. Previously, we have shown in vitro that GAD65 was cleaved to form its truncated form (tGAD65), which was more active than the full length form (fGAD65). The enzyme responsible for cleavage was later identified as calpain. Calpain is known to cleave its substrates either under a transient physiologica l stimulus or upon a sustained pathological insult. However, the precise role of calpain cleavage of fGAD65 is poorly understood. In this study, we examined the cleavage of fGAD65 under a range of conditions encompassing both physiological and pathological aspects, including rats under ischemia/reperfusion insult, rat brain synaptosomes or primary neuronal cultures subjected to excitotoxic stimulation with KCl. It was observed that the formation of tGAD65 progressively increased with increasing stimulus concentration. More importantly, cleavage of synaptic vesicle (SV) - associated fGAD65 by calpain was demonstrated, and the resulting tGAD65 harboring the active site of the enzyme was detached from the SVs. Vesicular uptake of the newly synthesized GABA into the SVs was found to be reduced in calpain treated SVs. Furthermore, we also observed that the levels of tGAD65 in the focal cerebral ischemic rat brain tissue increased corresponding to the elevation of local glutamate indica

Recent research in visual object recognition has shown that context can facilitate object recognition. This study assessed the effect of self-relevant familiarity of context in object recognition. Participants performed a task in which they had to recognize degraded objects shown under varying levels of contextual information. The level of degradation at which they could successfully recognize the target object was used as a measure of performance. There were five contextual conditions: (1) no context, (2) context, (3) context and size, (4) context and location, (5) context, size and location. Within each contextual condition, we compared the performance of "Expert" participants who viewed objects in the context of their own house and "Novice" participants who viewed those particular settings for the first time. Ratings were performed to assess each object's consistency, frequency, position consistency, typicality and shape distinctiveness. Object's size was the only contextual info rmation that did not affect performance. Contextual information significantly reduced the amount of bottom-up visual information needed for object identification for both experts and novices. An interaction (Contextual Information x Level of Familiarity) was observed. Expert participants' performance improved significantly more than novice participants' performance by the presence of contextual information. Location information affected the performance of expert participants, only when objects that occupied stable positions were considered. Both expert and novice participants performed better with objects that rated high in typicality and shape distinctiveness. Object's consistency, frequency and position consistency did not seem to affect expert participants' performance but did affect novice participants' performance.

Longitudinals lacking gene (LOLA) is a transcription factor that is involved in a variety of axon guidance decisions in Drosophila melanogaster nervous system. Besides having a role as an epigenetic silencer and in the programmed cell death in Drosophila's ovary, this gene is also an example of complex transcription unit. LOLA is a transcription repressor and can generate 17 DNA - binding isoforms, through alternative splicing, each containing distinct zinc-finger proteins. This unique DNAbinding binding sequence to which LOLA-ZFP binds has been determined for four of the lola isoforms F, J, P and K. Also, bioinformatics' tool approach has been taken to identify the target genes that are regulated by these four LOLA splice variants. Future work will be done for the five other LOLA isoforms to categorize their putative DNA-binding sequences and subsequently their protein interactions.