The purpose of the study was to evaluate the content of luteinizing hormone-releasing hormone (LHRH) and substance P (SP) in the brain and luteinizing hormone (LH) and follicle stimulating hormone (FSH) in the serum of normal and neonatally estrogenized male and female rats. Male and female Sprague Dawley pups were injected subcutaneously on day 2 of life with 1000 (mu)g estradiol benzoate or an equivalent volume of the oil vehicle. Between 80-90 days of age, the animals were decapitated and serum samples collected. Brain regions were dissected on ice, extracted in 2 N acetic acid, shell frozen, lyophilized and stored at -70(DEGREES) C until assayed. LHRH and SP content in the neonatally estrogenized rats, control males and control female rats during the estrous cycle were determined by radioimmunoassay in the organum vasculosum of the lamina terminalis-preoptic area (OVLT-POA), midbasal hypothalamus (MBH), thalamic-habenular (TH) region; SP content was also assayed in the pineal, anterior and posterior pituitary. Serum samples of all animals were assayed for LH and FSH concentration The mean concentrations of serum FSH and basal LH were significantly higher in males than control females. Serum LH varied significantly in females across the 4 days of the estrous cycle, with a marked increase in LH occurring on proestrus. LHRH content was significantly greater in the OVLT-POA of neonatally estrogenized females than estrogenized males whereas control male and female rats did not differ from each other. While no consistent male-female differences in SP content were observable in the OVLT-POA, TH, or posterior pituitary, males had significantly greater SP content in the anterior pituitary than their female littermates A significant linear correlation between OVLT SP concentration and OVLT LHRH concentration was found in all animals. Linear regression analysis of OVLT SP concentration and pineal SP content in control females revealed a relatively high significant correlation between these 2 SP values Exposure to neonatal estrogen reduced FSH concentrations in males and elevated it in females. Differences in LH normally found to exist between the sexes and in cycling females during the estrous cycle were diminished by neonatal estrogen treatment. In the OVLT-POA, the high dose of estrogen significantly decreased LHRH content in the male and increased it in the female. Higher contents of SP in the pineal and TH were measured in estrogenized males whereas SP contents in the pineal and TH region were suppressed in estrogenized females. In contrast, SP content in the anterior pituitary was significantly depressed below the level of controls in estrogenized males and significantly elevated in estrogenized females. Comparison of control and estrogenized rats indicated that LHRH content in the MBH and TH and SP content in the OVLT, MBH and posterior pituitary were not reliably altered by neonatal estrogen exposure The data are consistent with the concept that the hypothalamic-pituitary system is modified by estrogen circulating during the period of sexual differentiation. LHRH synthesis and perhaps, release, appear to be directly modified by neonatal estrogen LHRH and SP content were positively correlated. The fluctuations in ratio of the two peptides might be related to changes in dopamine (DA) content in the nerve terminals of the OVLT. The presence of SP changes of certain brain regions dependent upon animals' sex and neonatal estrogen treatment suggests that SP may function as a neurotransmitter in these extrahypothalamic regions and mediate DA-induced LHRH secretion and subsequent GTH release / acase@tulane.edu

acase@tulane.edu

acase@tulane.edu

Rapid subsidence and eustatic sea level rise are leading to increased flooding and perpetually waterlogged soils along the Gulf Coast. This study addresses the impact of this environmental change on coastal Louisiana bottomland hardwood forests. I employed a space-for-time substitution to compare seed banks, seedling banks, and seed rain in two sites of different hydroperiod, and to predict how small increase in hydroperiod may affect forested wetland community composition and dynamics Within terrestrial ecosystems, seed banks respond to disturbances by providing individuals for regeneration. In this study the wetter ('swamp') site's seed hank was more dense and species rich than the drier ('ridge') site's. Herbaceous species dominated both sites' seed banks. Tree and shrub seeds were most numerous and species rich in the ridge site, suggesting regeneration of the woody community requires a seed bank like that encountered in drier soils. Thus, as hydroperiod Continue to increase, seed of woody species will become unavailable for disturbance response Like seed banks, seedling hanks are active in disturbance response. While the cumulative number of seedlings censured over two years was equivalent at both sites, the ridge site hod greater seedling density, longer mean seedling lifespan, and greater seedling survivorship. In both sites, woody seedlings were denser and more species rich than herbaceous seedlings. Although a severe drought caused short-term decreases in seedling density, health, and leaf number regardless of site, the expected increase in hydroperiod will have long-term implications Lastly, I used the seed bank, seedling bank, and seed rain data to construct site-specific static life tables for selected woody species and life form groupings. These illustrate how individual species would respond to increases in hydroperiod. While some woody species, including Acer rubrum and Brunnichia ovata, will benefit from more hydric soils, most, including Celtis laevigata and Liquidambar styraciflua, will decline This study indicates that environmental changes already underway will lead to a loss of coastal plain bottomland hardwood forests as communities shift to species adapted to greater hydroperiod. If these trends are allowed t0 continue unabated, an eventual loss of all woody species, and therefore coastal forested wetlands, is expected / acase@tulane.edu

acase@tulane.edu

The effects of prenatal stress and maternal age on developmental indices and sexual differentiation in male and female rats were investigated. Pregnant females exposed to the stress of restraint and high intensity illumination during Days 14-21 of gestation produced fewer live pups and exhibited shorter gestation lengths than nonstressed control females. Male offspring of stressed mothers had lower body weights, lighter testes and delayed testes descent as compared to the male offspring of nonstressed mothers. These effects were greatest in male offspring of younger stressed mothers. Copulatory behaviors were also impaired in prenatally stressed males. Prenatally stressed males exhibited fewer mounts and ejaculations and longer latencies to intromission and ejaculation than nonstressed males. Prenatally stressed female offspring had shortened anogenital distance, delayed eye opening and lower body weights than nonstressed females. The effect of stress on eye opening and body weight was greatest in the offspring of younger mothers. Anogenital distance, however, was altered more in offspring of older stressed mothers. Regardless of the age of the mother, prenatally stressed offspring exhibited irregularities in estrus cycling and alterations in proceptive behaviors. Females injected on Day 3 with 3.5 (mu)g Testosterone Propionate (TP) had earlier vaginal opening, increased incidence of cystic ovaries and became anovulatory at an earlier age than oil-injected females. More TP-injected females of stressed mothers had cystic ovaries and were sterile at an earlier age than any other group. TP-injected females exhibited reduced levels of proceptive behavior which suggests similar effects of prenatal stress and neonatal androgenization / acase@tulane.edu

acase@tulane.edu

acase@tulane.edu

The prevalence of low bearing capacity soils in New Orleans has generated tremendous problems in street construction During the 1960's, trial use of a new material, a synthetic fabric now called Engineering Fabric or Geotextile, was attempted for road construction in the area of soft soil. Engineering applications of fabric first started in European countries such as France, West Germany and others, and later in the United States in the 1970's No previous study has been made of its use in the New Orleans area. The scope of this research is to learn how Engineering Fabric or Geotextile affects the pavement behavior when used as a pavement component This research was funded by the Louisiana Department of Transportation and Development, with some manufacturers participating in the cost of instrumentation including the instruments and their installation during construction The selection of the types of Engineering Fabric to be tested was based upon the willingness of the manufacturers to participate in the investigation. Six types of Engineering Fabric known to the Investigators at the time were considered for testing, including both woven and non-woven types, but only three manufacturers decided to participate The following functions of Engineering Fabric were tested: (1) Pavement reinforcement; (2) Separation of subgrade from base course; (3) Subgrade drainage; (4) Reflective cracking retardation To achieve the testing of these functions, the following arrangements were made: (1) Placing the fabric between the subgrade and the aggregate base course. (2) Placing fabric between the compacted subgrade and the new asphalt paving. (3) Placing fabric on existing cracked up asphalt paving and overlaying with two inches of bituminous concrete For all test sections, adjoining sections of street built without fabric were observed as control sections The following data were collected: (1) Strain in the base course and in the subgrade under traffic load. (2) Moisture content of the subgrade. (3) Pavement deflection by dynaflect. (4) Surface deformation by Mays Ridemeter. (5) Traffic Volume. (6) Surface cracks mapping by visual observation Conclusions were drawn and recommendations made on the use of Engineering Fabric in New Orleans / acase@tulane.edu

acase@tulane.edu