AGRICULTURAL BIRD PROBLEMS IN THE SOUTHEAST

Our chairman has wisely asked that we not spend all of our time here telling each other about our bird problems. In the Southeast, our difficulties with blackbirds are based upon the same bird habits that cause trouble elsewhere: they flock, they roost and they eat, generally taking advantage of the readily available handouts that today's agricul¬tural practices provide. Those of us on the receiving end of these de¬predations of course think that damage in our own particular area must be far the worst, anywhere. Because of the location of our meeting place today, perhaps it is worthwhile to point out that a report prepared by our Bureau's Washington office this year outlined the problem of blackbird damage to corn in the Middle Atlantic States, the Great Lakes Region and in Florida, and then followed with this statement--"An equally serious problem occurs in rice and grain sorghum fields of Arkansas, Mississippi, Texas and Louisiana." The report also men¬tions that the largest winter concentrations of blackbirds are found in the lower Mississippi Valley. Our 1963-64 blackbird-starling survey showed 43 principal roosts totaling approximately 100 million of these birds in Virginia, the Carolinas, Georgia, Alabama, Tennessee and Kentucky. We have our own birds during the summer plus the "tourist" birds from up here and elsewhere during the winter, and all of these birds must eat, so suffice it to say that we, too, have some bird problems in the Southeast. I'm sure you're more interested in what we're doing about them. To keep this in perspective also, please bear in mind that against the magnitude of these problems, our blackbird control research staff at Gainesville consists of 3 biologists, 1 biochemist and one technician. And unfortunately, none of us happens to be a miracle worker. I think, though, we have made great progress toward solving the bird problems in the Southeast for the man-hours that have been expended in this re¬search. My only suggestion to those who are impatient about not having more answers is that they examine the budget that has been set up for this work. Only then could we intelligently discuss what might be expected as a reasonable rate of research progress. When I think about what we have accomplished in a short span of time, with very small expenditure, I can assure you that I am very proud of our small research crew at Gainesville--and I say this quite sincerely. At the Gainesville station, we work under two general research approaches to the bird damage problem. These projects have been assigned to us. The first is research on management of birds, particularly blackbirds and starlings destructive to crops or in feedlots, and, secondly, the development and the adaptation of those chemical compounds found to be toxic to birds but relatively safe to mammals. These approaches both require laboratory and field work that is further subdivided into several specific research projects. Without describing the details of these now, I want to mention some of our recent results. From the results, I'm sure you will gather the general objectives and some of the procedures used.

Do Students Progress if They Self-Assess? A Study in Small-Group Work

In this action research study of my classroom of 8th grade mathematics, I investigated the effects of self-assessment on student group work. Data was collected to see how self-assessment affected small-group work, usage of precise mathematical vocabulary, and student attitudes toward mathematics. Self-assessment allowed the students to periodically evaluate their own learning and their involvement in math class. I discovered that the vast majority of students enjoy working in small-groups, and they feel they are good group members. Evidence in regard to use of precise mathematical vocabulary showed an increased awareness in the importance of its usage. Student attitudes toward mathematics remained positive and unchanged throughout the research. As a result of this research, I plan to continue use of small-group work and selfassessment. I will continue emphasis on the inclusion of precise mathematical vocabulary as well as on training on cooperative learning strategies.

I. Development of the In Situ Reductive Ozonolysis of Alkenes with Tertiary Amine N-Oxides. II. Progress toward the Asymmetric Synthesis of Peroxyplakoric Acid A3.

Ozone, first discovered in the mid 1800’s, is a triatomic allotrope of oxygen that is a powerful oxidant. For over a century, research has been conducted into the synthetic application and mechanism of reactions of ozone with organic compounds. One of the major areas of interest has been the ozonolysis of alkenes. The production of carbonyl compounds is the most common synthetic application of ozonolysis. The generally accepted mechanism developed by Rudolf Criegee for this reaction involves the 1,3-electrocyclic addition of ozone to the π bond of the alkene to form a 1,2,3-trioxolane or primary ozonide. The primary ozonide is unstable at temperatures above -100 °C and undergoes cycloreversion to produce the carbonyl oxide and carbonyl intermediates. These intermediates then recombine in another 1,3-electrocyclic addition step to form the 1,2,4-trioxolane or final ozonide. While the final ozonide is often isolable, most synthetic applications of ozonolysis require a subsequent reductive or oxidative step to form the desired carbonyl compound. During investigations into the nucleophilic trapping of the reactive carbonyl oxide, it was discovered that when amines were used as additives, an increased amount of reaction time was required in order to consume all of the starting material. Surprisingly, significant amounts of aldehydes and a suppression of ozonide formation also occurred which led to the discovery that amine N-oxides formed by the ozonation of the amine additives in the reaction were intercepting the carbonyl oxide. From the observed production of aldehydes, our proposed mechanism for the in situ reductive ozonolysis reaction with amine N-oxides involves the nucleophilic trapping of the carbonyl oxide intermediate to produce a zwitterionic adduct that fragments into 1O2, amine and the carbonyl thereby avoiding the formation of peroxidic intermediates. With the successful total syntheses of peroxyacarnoates A and D by Dr. Chunping Xu, the asymmetric total synthesis of peroxyplakorate A3 was investigated. The peroxyplakoric acids are cyclic peroxide natural products isolated from the Plakortis species of marine sponge that have been found to exhibit activity against malaria, cancer and fungi. Even though the peroxyplakorates differ from the peroxyacarnoates in the polyunsaturated tail and the head group, the lessons learned from the syntheses of the peroxyacarnoates have proven to be valuable in the asymmetric synthesis of peroxyplakorate A3. The challenges for the asymmetric synthesis of peroxyplakorate A3 include the stereospecific formation of the 3-methoxy-1,2-dioxane core with a propionate head group and the introduction of oxidation sensitive dienyl tail in the presence of a reduction sensitive 1,2-dioxane core. It was found that the stereochemistry of two of the chiral centers could be controlled by an anti-aldol reaction of a chiral propionate followed by the stereospecific intramolecular cyclization of a hydroperoxyacetal. The regioselective ozonolysis of a 1,2-disubstituted alkene in the presence of a terminal alkyne forms the required hydroperoxyacetal as a mixture of diastereomers. Finally, the dienyl tail is introduced by a hydrometallation/iodination of the alkyne to produce a vinyl iodide followed by a palladium catalyzed coupling reaction. While the coupling reaction was unsuccessful in these attempts, it is still believed that the intramolecular cyclization to introduce the 1,2-dioxane core could prove to be a general solution to many other cyclic peroxides natural products.