Use of cryopreserved spermatozoa for caprine in vitro fertilization (IVF).

Proceedings Annual Conference of the International Embryo Transfer Society, Nice Acropolis, Nice, France, Jan., 1997

Development of bovine embryos cultured with media containing glucose.

Blastocyst (BL) expansion and blastocoel formation are coupled with increase in the glucose (GLU) metabolism, which is higher in morphologically normal than in degenerate embryos (Rieger et aI., 1992). This study aimed to determine the dose levei and duration of addition of GLU to culture medium that ensures the best results in development of in vitro produced bovine embryos

Effects of EGTA and cytochalasin-B during freezing and vitrification of immature and mature bovine and rhesus monkey (M. mulatta) oocytes.

Cryopreservation procedures have been shown to be extremely disruptive to the plasma membrane and intracellular organization of mammalian oocyte. Cytochalasin-B (Cyt-B) or EGT A may stabilize oocyte cytoskeletal elements prior to Cryopreservation and make the plasma membrane less rigid and more elastic to avoid injury during the osmotic stresses of freezing. Experiments were conducted to assess the morphological viability and developmental potential of bovine and rhesus monkey oocytes roter exposure to Cyt-B or EGTA prior to freezing and vitrification. ln the bovine experiments: The methods of oocyte isolation, in vitro maturation (IVM), in vitro fertilization (IVF) , and embryonic development (IVC) were as described elsewhere (Biol Reprod. 55:333-339, 1996). AIl data were analyzed by ANOV A and Chi-square using "StatMost" for Windows. ln an initial experiment, a group of ilnmature (GV) oocytes and oocytes roter IVM (ova) were randomly selected and pretreated for 5 min with EGTA (O.IM) or Cyt-B (Img/ml) without cryoprotectant (CPA), and another group were equilibrated for 15 min with the CPA (1.5 M ethylene glycol mixed with 0.5 M glycerol in PHS) roter pretreatment with EGTA or Cyt-B. AIl oocytes were diluted and/or washed and immediately used for IVM and/or IVF and IVC. No significant differences in cleavage (C) development and blastocyst (B) hatching among treatments in the GV oocytes group. Percentages of early C, morula (M), B, and expanded B (EB) development ranged 72-82%, 53-65%, 40-47% and 25-35% respectively. Ova treated with EGTA without CPA produced significantly (P<.05) higher C (31/41,75%), M (48.8%), B (40%) and EB (24.4%) than with Cyt-B. ln the slow freezing experiment, a total of 105 GV oocytes and 155 ova were exposed to (a) zero (b EGTA, or ~) Cyt-B before equilibration with CPA + 0.5 sucrose in PHS plus 15% Fetal bovine serum (PBS/FBS). Gametes were loaded into sterile cryovials, cooled at 2°Chnin to -7°C, seeded, cooled at 0.3°Chnin to -32°C, then plunged in LN2. They were thawed.in air (10 sec), then wann water (35°C), and diluted out of CPA in 3 steps (1, 0.5, 0.2 M sucrose). Three replicated showed that although many of the frozen-thawed oocytes/ova survived as judged by morphology (range 70-80%), their developmental potential was severely retarded. C ranged between 0% to 14.3%. ln the vitrification experiment, a total of 135 GV oocytes and 90 ova were grouped as above and vitrified in straws containing a mixture of 3.25M glycerol and 4.5M ethylene glycol plus 0.5 sucrose in PBS/FBS. Here, higher (P<.05) morphological survival rates (98%) foIlowed pretreatment with EGT A. However, the developmental potential was very low among aIl groups ranging between 0% to 17.7%. ln the monkey experiments: The methods of oocyte isolation, IVM and IVF was as described ( Theriogenology 43:362, 1995). A total of 72 GV oocytes and 42 ova were subjected to slow rate freezing and vitrification in groups as described for cow oocytes above. Pretreatment of both GV oocytes or ova with EGTA or Cyt-B prior to freezing or vitrification resulted in 77.6% morphological survival which was significantly (P<.OI) higher than for the control (50%). No differen?s in fertilization and development were detected mnong treatment. Per?ntages of C to 4-?Il stage ranged from 50-67%. Results suggest prefreeze treatment with EGTA and/or Cyt-B may be useful in enhancement of oocyte/ovum cryopreservation.Proceedings Annual Conference of the International Embryo Transfer Society, Nice Acropolis, Nice, France, Jan., 1997

Volcanic-aerosol-induced changes in stratospheric ozone following the eruption of Mount Pinatubo

Measurements of lower stratospheric ozone in the Tropics using electrochemical concentrations cell (ECC) sondes and the airborne UV Differential Absorption Lidar (DIAL) system after the eruption of Mt. Pinatubo are compared with the Stratospheric Aerosol and Gas Experiment 2 (SAGE 2) and ECC sonde measurements from below the eruption to determine what changes have occurred as a result. Aerosol data from the Advanced Very High Resolution Radiometer (AVHRR) and the visible and IR wavelengths of the lidar system are used to examine the relationship between aerosols and ozone changes. Ozone decreases of 30 percent at altitudes between 19 and 26 km, partial column (16-28 km) decreases of about 27 D.U., and slight increases (5.4 D.U.) between 28 and 31 km are found in comparison with SAGE 2 climatological values

Does rumination mediate the relationship between emotion regulation ability and posttraumatic stress disorder?

Background and objectives: Trauma-related rumination has been suggested to be involved in the maintenance of posttraumatic stress disorder (PTSD). This view has empirically been supported by extensive evidence using cross-sectional, prospective, and experimental designs. However, it is unclear why trauma survivors engage in rumination despite its negative consequences. The current study aimed to explore the hypothesis that low emotion regulation ability underlies trauma-related rumination. Methods: Emotion regulation ability and trauma-related rumination were assessed in 93 road traffic accident survivors 2 weeks post-trauma. In addition, symptom levels of PTSD were assessed at 2 weeks as well as 1, 3, and 6 months follow-up. Results: Emotion regulation ability was significantly related to trauma-related rumination as well as levels of PTSD symptoms. In addition, the association between low emotion regulation ability and PTSD was mediated by rumination. Conclusions: The findings support the view that rumination is used as a dysfunctional emotion regulation strategy by trauma survivors

Calculation of The Band Gap Energy and Study of Cross Luminescence in Alkaline-Earth Dihalide Crystals

The band gap energy as well as the possibility of cross luminescence processes in alkaline-earth dihalide crystals have been calculated using the ab initio Perturbed-Ion (PI) model. The gap is calculated in several ways: as a difference between one-electron energy eigenvalues and as a difference between total energies of appropriate electronic states of the crystal, both at the HF level and with inclusion of Coulomb correlation effects. In order to study the possibility of ocurrence of cross luminescence in these materials, the energy difference between the valence band and the upmost core band for some representative crystals has been calculated. Both calculated band gap energies and cross luminescence predictions compare very well with the available experimental results.Comment: LaTeX file containing 8 pages plus 1 postscript figure. Final version accepted for publication in The Journal of the Physical Society of Japan. It contains a more complete list of references, as well as a more detailed comparison with previous theoretical investigations on the subjec

Large-scale ozone and aerosol distributions, air mass characteristics, and ozone fluxes over the western Pacific Ocean in late winter/early spring

Large‐scale measurements of ozone (O3) and aerosol distributions were made from the NASA DC‐8 aircraft during the Transport and Chemical Evolution over the Pacific (TRACE‐P) field experiment conducted in February–April 2001. Remote measurements were made with an airborne lidar to provide O3 and multiple‐wavelength aerosol backscatter profiles from near the surface to above the tropopause along the flight track. In situ measurements of O3, aerosols, and a wide range of trace gases were made onboard the DC‐8. Five‐day backward trajectories were used in conjunction with the O3 and aerosol distributions on each flight to indicate the possible origin of observed air masses, such as from biomass burning regions, continental pollution, desert regions, and oceanic regions. Average latitudinal O3 and aerosol scattering ratio distributions were derived from all flights west of 150°E, and these distributions showed the average latitude and altitude dependence of different dynamical and chemical processes in determining the atmospheric composition over the western Pacific. TRACE‐P (TP) showed an increase in the average latitudinal distributions of both O3 and aerosols compared to PEM‐West B (PWB), which was conducted in February–March 1994. O3, aerosol, and potential vorticity levels were used to identify nine air mass types and quantify their frequency of occurrence as a function of altitude. This paper discusses the characteristics of the different air mass types encountered during TP and compares them to PWB. These results confirmed that most of the O3 increase in TP was due to photochemistry. The average latitudinal eastward O3 flux in the western Pacific during TP was found to peak near 32°N with a total average O3 flux between 14 and 46°N of 5.2 Tg/day. The eastward total CO flux was calculated to be 2.2 Tg‐C/day with ∼6% estimated from Asia. The Asian flux of CO2 and CH4 was estimated at 4.9 and 0.06 Tg‐C/day

Ozone, aerosol, potential vorticity, and trace gas trends observed at high‐latitudes over North America from February to May 2000

Ozone (O3) and aerosol scattering ratio profiles were obtained from airborne lidar measurements on thirty‐eight flights over seven deployments covering the latitudes of 40°–85°N between 4 February and 23 May 2000 as part of the Tropospheric Ozone Production about the Spring Equinox (TOPSE) field experiment. Each deployment started from Broomfield, Colorado, with bases in Churchill, Canada, and on most deployments, Thule Air Base, Greenland. Nadir and zenith lidar O3 measurements were combined with in situ O3 measurements to produce vertically continuous O3 profiles from near the surface to above the tropopause. Potential vorticity (PV) distributions along the flight track were obtained from several different meteorological analyses. Ozone, aerosol, and PV distributions were used together to identify the presence of pollution plumes and stratospheric intrusions. Ozone was found to increase in the middle free troposphere (4–6 km) at high latitudes (60°–85°N) by an average of 4.6 ppbv/mo (parts per billion by volume per month) from about 54 ppbv in early February to over 72 ppbv in mid‐May. The average aerosol scattering ratios at 1064 nm in the same region increased rapidly at an average rate of 0.36/mo from about 0.38 to over 1.7. Ozone and aerosol scattering were highly correlated over the entire field experiment, and PV and beryllium (7Be) showed no significant positive trend over the same period. The primary cause of the observed O3 increase in the mid troposphere at high latitudes was determined to be the photochemical production of O3 in pollution plumes with less than 20% of the increase from stratospherically‐derived O3

Two years survival rate of class II composite resin restorations prepared by ART with and without a chemomechanical caries removal gel in primary molars

The aim was to test the null hypotheses that there is no difference: (1) in carious lesion development at the restoration margin between class II composite resin restorations in primary molars produced through the atraumatic restorative treatment (ART) with and without a chemomechanical caries removal gel and (2) in the survival rate of class II composite resin restorations between two treatment groups after 2 years. Three hundred twenty-seven children with 568 class II cavitated lesions were included in a parallel mouth study design. Four operators placed resin composite (Filtek Z 250) restorations bonded with a self-etch adhesive (Adper prompt L pop). Two independent examiners evaluated the restorations after 0.5, 1, and 2 years using the modified Ryge criteria. The Kaplan–Meier survival method was applied to estimate survival percentages. A high proportion of restorations were lost during the study period. Therefore, the first hypothesis could not be tested. No statistically significant difference was observed between the cumulative survival percentages of restorations produced by the two treatment approaches over the 2-year period (ART, 54.1 ± 3.4%; ART with Carisolv™, 46.0 ± 3.4%). This hypothesis was accepted. ART with chemomechanical gel might not provide an added benefit increasing the survival percentages of ART class II composite resin restorations in primary teeth