Effect of progesterone on the expression of estrus at the first postpartum ovulation in dairy cattle.

Fifty-two lactating Holstein cows were randomly assigned to receive either a progesterone-releasing (2 g of progesterone) or a control-releasing intravaginal device (0 g of progesterone). Intravaginal devices were inserted on d 10 and removed on d 15 postpartum. Daily blood samples were collected from d 10 to 90 postpartum for subsequent determination of progesterone concentrations. Observations for estrus were conducted three times daily in a dirt paddock containing a testosterone-treated cow. Serum concentrations of progesterone in the progesterone-releasing intravaginal device group were elevated on d 11, 12, 13, 14, and 15 compared with those of the control group. The days to first post-partum ovulation were similar between the treated and control groups, respectively (30.6 vs. 30.5 d). Also similar was the proportion of cows expressing estrus at first, second, and third postpartum ovulations (9/27 vs. 3/24, 14/23 vs. 15/21, and 14/21 vs. 9/15, respectively), length of the first postpartum estrous cycle (17.9 vs. 18.3 d), and peak serum concentrations of progesterone during the first estrous cycle (3.5 vs. 2.9 ng/ml). These data indicate that administration of progesterone early postpartum did not increase the proportion of cows expressing estrus at the first ovulation.     

Development of the PCRV steam generator cavity closure for the GCFR

One phase of the program to develop a prestressed concrete reactor vessel for the gas-cooled fast reactor consists of the design, analysis and testing of models of the steam generator cavity and central core cavity closure . The analytical and experimental results for a model of the steam generator cavity closure plug will be presented. This test which is designed to measure pressure response and ultimate capacity of the plug will be followed by tests of models to provide design verification of the combined plug, seal and toggle-type hold-down system response.     

Polymeric catenanes

A crosslinked polybutadiene containing a cyclic depsipeptide (Valinomycin) has been synthesized in which there is some possibility of threading to produce a catenated structure (polymeric catenane). Unthreaded rings were removed by extraction with toluene. An elemental analysis indicated the yield of threaded rings to be greater than the calculated expected yield. The total amount of threaded Valinomycin present was 0.37 percent. The rings showed no effect on the calorimetric glass transition temperature, but did result in an increase in the tensile modulus.     

Progressive volume rendering of large unstructured grids

We describe a new progressive technique that allows real-time rendering of extremely large tetrahedral meshes. Our approach uses a client-server architecture to incrementally stream portions of the mesh from a server to a client which refines the quality of the approximate rendering until it converges to a full quality rendering. The results of previous steps are re-used in each subsequent refinement, thus leading to an efficient rendering. Our novel approach keeps very little geometry on the client and works by refining a set of rendered images at each step. Our interactive representation of the dataset is efficient, light-weight, and high quality. We present a framework for the exploration of large datasets stored on a remote server with a thin client that is capable of rendering and managing full quality volume visualizations.     

Resonant two-photon ionization mass spectrometry of jet-cooled phenolic acids and polyphenols

A method for analyzing phenolic acids and polyphenols by means of resonant two-photon ionization (R2PI) mass spectrometry coupled with laser desorption and supersonic jet cooling is described. The R2PI spectra of gallic acid, 3-O-methylgallic acid, protocatechuic acid, syringic acid, vanillic acid, and trans-resveratrol are vibronically resolved and distinct to allow for unambiguous identification. For vanillic acid, its R2PI spectrum can be separated into contributions of two rotational isomers based on UV-UV and IR-UV double-resonance spectroscopy. Since R2PI spectra display sharp and well-resolved peaks, the laser wavelength can be tuned for selective ionization of targeted molecules. The mass spectrum recorded under jet-cooled conditions and at the resonant wavelength displays only the molecular ion peak with no fragmentation or background peaks. Picogram sensitivity and linear response over a nanogram range allows trace quantitative measurements of target molecules in complex matrixes. These techniques were applied to detect syringic acid in a model archaeological wine vessel.     

Venezuelan equine encephalitis and Oropouche virus infections among Peruvian army troops in the Amazon region of Peru

An outbreak of a febrile illness characterized by headache, ocular pain, myalgia, and arthralgia occurred during June 1994 among Peruvian army troops in Northern Peru. On June 14-16, 1994, clinical data and blood samples were obtained from eight soldiers with a febrile illness, and from 26 others who had a history of febrile illness during the past three months. A follow-up blood sample was obtained 107 days later from four of the febrile and seven of the afebrile soldiers. Serum samples were tested for dengue (DEN), Oropouche (ORO), and Venezuelan equine encephalitis (VEE) IgM and IgG antibodies by an enzyme-linked immunosorbent assay (ELISA). Virus isolation was performed by inoculation of newborn mice and Vero cell cultures. Viral isolates were identified by immunofluorescence, ELISA, and nucleotide sequencing. A VEE virus infection was confirmed in three of the eight febrile soldiers, two by virus isolation, and one by serology. Antigenic analysis indicated that one of the virus isolates was similar to VEE subtype I, variety ID, viruses previously isolated in Colombia and Venezuela. Nucleotide sequence data showed that both viral isolates were identical to one another and closely related to VEE ID viruses previously isolated in Peru, Colombia, and Venezuela. Serologic results showed that two of 26 afebrile soldiers had IgM antibody to VEE and four had IgG antibody to VEE; two febrile soldiers had IgG antibody in their first serum samples. Oropouche-specific IgM antibody was detected in one of the eight febrile and five of the afebrile soldiers, and 18 of the 34 soldiers had low titers of ORO IgG antibody titers, which did not meet the diagnostic criteria for confirmed cases. All soldiers were negative for DEN IgM antibody, and 10 had flavivirus IgG antibody that reacted with DEN antigens. These data indicated that VEE ID virus was one of the causes of illness among Peruvians soldiers and that this was the first association of this VEE subtype with human disease in Peru.