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  • 1
    Electronic Resource
    Electronic Resource
    Tertiary and Quaternary vegetation history of the Great Salt Lake, Utah, USA (1998)
    Springer
    Journal of paleolimnology 19 (1998), S. 417-427 
    Details
    ISSN: 1573-0417
    Keywords: palynology ; Great Salt Lake ; climate ; Pliocene ; Pleistocene ; pluvial
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences
    Notes: Abstract Pollen analysis of 5 wells drilled to bedrock in the Great Salt Lake, Utah, USA provide a record vegetation change over the last ca 13.5 Ma. Over 440 pollen samples have been counted. The longest record presented is for the mid-lake Bridge Well. Close-interval (3–10 Ka) sampling is presented for the upper Indian Cove well. Chronologic control is provided by identification volcanic tephra and by K/Ar, Ar/Ar, and fission-track dates. Ash determinations are based on electron microprobe analyses of iron, calcium, and other elements compared to Neogene ash data at the University of Utah. Sedimentation begins 38 Ma, with good pollen preservation is sediments younger than 13.5 Ma, and no obvious gaps in sedimentation after 6 Ma. The upland vegetation is desert from the late Miocene onward, with Sarcobatus and Ephedra pollen dominance during the late Miocene (〈5 Ma). Chenopodiaceae-Amaranthus, and Artemisia gain dominance during the Pliocene (5–2.5 Ma) and early Pleistocene. Pinus and Artemisia sharply increase in the late Pleistocene (0.75 Ma). The pollen of 'Tertiary exotics' (elm, hickory, Ostrya-Carpinus) is rare, but persists into the Pleistocene. Major vegetation – climatic events occur 3.7 and 2.5 Ma. Increased pollen concentration and sedimentation rate after 310 Ka are attributed to the diversion of the Bear River into the Bonneville Basin. Glacial-interglacial cycles appear as alternations of Chenopodiaceae-Amaranthus (interglacial) vs Artemisia (glacial) during the Pliocene and early Pleistocene, and of Cupressaceae, Sarcobatus, and Gramineae (interglacial) vs Picea, Abies, and Pseudotsuga (glacial) during the late Pleistocene. Pluvial cycles are separated by interpluvial peaks in percentages of wetground and aquatic types. Six interpluvials are indicated during the last 759 Ka, with pluvial cycles of ca 100 Ka cyclicity back to 1.5 Ma.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007959203433
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  • 2
    Electronic Resource
    Electronic Resource
    Orbital history and seasonality of regional precipitation (1994)
    Springer
    Human ecology 22 (1994), S. 97-113 
    Details
    ISSN: 1572-9915
    Keywords: Holocene ; Pluvial ; monsoon ; paleoclimate ; southwest ; model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Energy, Environment Protection, Nuclear Power Engineering , Ethnic Sciences
    Notes: Abstract The Arizona monsoon, a major source of precipitation in the Southwest, shares many features with the monsoons of other continents. Computer modeling and fossil data indicate maximum extent of the African and Asian monsoons 9000 years ago. Fossil data indicate increased summer precipitation 9000 years ago, synchronous with the maxima of the African and Asian monsoons and, paradoxically, with the early-Holocene xerothermic of the Pacific Northwest. Climate model runs for 6000, 9000, 11,500, 13,000, and 18,000 years ago indicate increased summer precipitation 9000 years ago and a reciprocal relationship between precipitation in the Northwest and Southwest, but they relegate insolation to a role secondary to the North American ice sheet in regulating climate, and suggest a non-monsoon source for much of the summer precipitation in the Southwest prior to 9000 years ago.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02168765
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  • 3
    Electronic Resource
    Electronic Resource
    Clomiphene citrate and hMG: An alternative stimulation protocol for selected failed in vitro fertilization patients (1995)
    Springer
    Journal of assisted reproduction and genetics 12 (1995), S. 8-12 
    Details
    ISSN: 1573-7330
    Keywords: in vitro fertilization ; clomiphene citrate ; ovarian stimulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Purpose This study was carried out to evaluate the potential role of the combination clomiphene citrate/human menopausal gonadotropin (CC/hMG) for patients who failed previous in vitrofertilization (IVF) attempts with gonadotropin-releasing hormone analogs (GnRH- a) and/ or exogenous gonadotropins. Methods Patients were stimulated with CC/hMG (n=93) after unsuccessfully undergoing 182 gonadotropin cycles with (n=106) or without (n=76) luteal-phase GnRH- a. Cancellation rate, length of stimulation, and peak estradiol levels did not differ significantly between the two regimens. Results Although fewer oocytes were retrieved when the CC/hMG combination was used, 16 patients were able to successfully achieve a pregnancy (26.2% delivery rate/ transfer). When daily follicle stimulating hormone (FSH) levels were measured in two successive cycles in those women who conceived with the CC/hMG stimulation, baseline levels did not differ when compared with a previous GnRH-a/hMG cycle. Nevertheless, serum FSH levels rose rapidly and remained higher in the GnRH- a/hMG cycle, reaching significantly higher levels on day of human chorionic gonadotropin (hCG) administration. Conclusion Selected patients who failed previous IVF attempts with gonadotropins with or without GnRH analogs may benefit from the addition of CC to their ovarian stimulation protocol.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02214121
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  • 4
    Electronic Resource
    Electronic Resource
    Expression of Apoptosis-Related Genes in Human Oocytes and Embryos (2000)
    Springer
    Journal of assisted reproduction and genetics 17 (2000), S. 521-533 
    Details
    ISSN: 1573-7330
    Keywords: single-cell reverse transcriptase–polymerase chain reaction ; human embryos ; apoptosis related genes ; Tunel labeling ; annexin V staining
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Purpose: The objective was to study whether apoptosis occurs in human embryogenesis. Methods: Human viable, arrested, and nonviable embryos and immature, and nonfertilized oocytes donated by our patients were used to detect apoptosis by Tunel labeling, annexin staining, and single-cell reverse transcriptase–polymerase chain reaction (RT-PCR). Results: DNA fragmentation and phosphotidylserine translocation, the two markers for apoptosis, were detected frequently in fragmented human embryos derived from in vitro fertilization–embryo transfer (IVF-ET). Using RT-PCR, apoptotic genes also were detected in these embryos. The frequencies of gene expression in viable embryos, arrested embryos, nonviable embryos, immature oocytes, and nonfertilized oocytes were: 7/8, 5/5, 5/6, 0/6, 0/3, for Bax; 8/8, 5/5, 7/7, 0/4, 0/5 for Fas; 2/8, 0/2, 0/3, 0/5, 0/3 for BCL-2; 0/8, 1/3, 0/2, 0/3, 0/2 for Fas-ligand; and 8/8, 17/17, 21/21, 24/24, 15/15 for actin, respectively. Conclusions: Our preliminary data did not show a significant difference in the expression frequency of all studied genes between viable embryos and nonviable or arrested embryos. However, the expression of Bax and Fas was noticeably higher in nonviable embryos than in viable embryos as judged by the intensities of amplicons visualized after ethidium bromide staining. In addition, BCL-2 was only detected in viable embryos. Whether embryos quality is related to the regulation of BCL-2, Bax, and Fas expressions requires further study.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009497925862
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  • 5
    Electronic Resource
    Electronic Resource
    Microsurgical fertilization procedures: The absence of stringent criteria for patient selection (1992)
    Springer
    Journal of assisted reproduction and genetics 9 (1992), S. 197-206 
    Details
    ISSN: 1573-7330
    Keywords: subzonal sperm insertion ; partial zona dissection ; sperm factors ; oligoasthenoteratozoospermia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Subzonal sperm insertion and partial zona dissection were applied in 250 in vitro fertilization cycles in couples (n =200) with abnormal semen analyses; 61 clinical pregnancies were established (24% per egg retrieval). Patients were selected without using minimal cutoff criteria. The study included patients with 0% normal sperm forms (strict criteria), no motile sperm (but some live cells), and sperm counts which could be assessed only after centrifugation. Patients were categorized into three subsets. Group A (n =116 cycles) failed to fertilize in a previous cycle. Group B (n =40) was excluded from IVF due to the severity of sperm profiles, such as a maximum of 2% normal forms. Group C (n =94) constitutes those patients for whom a standard cycle could possibly result in failure. Monospermic fertilization rates were 18% (A), 19% (B), and 24% (C). The incidences of embryo replacement were 63% (A), 53% (B), and 69% (C). Rates of clinical pregnancy were 22% (A), 23% (B), and 28% (C). The presence of one, two, or three semen abnormalities did not correlate with the outcome of microsurgical fertilization. Twenty-two percent of patients with combined oligoasthenoteratozoospermia became pregnant. Moreover, ongoing pregnancies were established in instances with 0% normal sperm forms and no progressively motile spermatozoa. It is concluded that stringent cutoff criteria may not be necessary when both partial zona dissection and subzonal sperm insertion are performed efficiently.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01203813
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  • 6
    Electronic Resource
    Electronic Resource
    Improved pregnancy outcome with gonadotropin releasing hormone agonist (GnRH-a) stimulation is due to the improvement in oocyte quantity rather than quality (1992)
    Springer
    Journal of assisted reproduction and genetics 9 (1992), S. 338-344 
    Details
    ISSN: 1573-7330
    Keywords: embryo quality ; embryo quantity ; gonadotropin releasing hormone agonist ; implantation rate ; multiple pregnancy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The impact of gonadotropin releasing hormone agonist (GnRH-a) on the quality and quantity of oocytes harvested in in vitro fertilization—embryo transfer (IVF-ET) patients was studied by comparing the results for patients stimulated with gonadotropin alone and with gonadotropin plus GnRH-a. Adding GnRH-a significantly improved the viable pregnancies per transfer and reduced the spontaneous abortions, which seemed to improve oocyte quality. However, when oocyte quality was evaluated by the fertilization rate and the implantation and delivery rates per embryos transferred, there were no significant difference in the results, indicating that GnRH-a did not improve the oocyte quality. On the other hand, GnRH-a significantly increased the average number of oocytes harvested, fertilized, and transferred, and this increased number of oocytes transferred has been demonstrated to increase pregnancy and multiple-pregnancy rates. Multiple pregnancy with more embryos implanted would significantly reduce the abortion rate. Abortion rates decreased inversely to the number of embryos implanted. Our data strongly suggest that the efficacy of GnRH-a on IVF-ET patients was due more to the quantity increase than the quality of embryos transferred.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01203956
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  • 7
    Electronic Resource
    Electronic Resource
    Preimplantation Genetic Diagnosis: Considerations for Use in Elective Human Embryo Sex Selection (1999)
    Springer
    Journal of assisted reproduction and genetics 16 (1999), S. 509-511 
    Details
    ISSN: 1573-7330
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1020588902509
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  • 8
    Electronic Resource
    Electronic Resource
    Expression of Inhibin/Activin Subunits and Their Receptors and Binding Proteins in Human Preimplantation Embryos (1999)
    Springer
    Journal of assisted reproduction and genetics 16 (1999), S. 73-80 
    Details
    ISSN: 1573-7330
    Keywords: activin ; activin receptors ; semiquantitative RT-PCR ; gene expression ; embryo-endometrium interaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Purpose: Our purpose was to study the role of inhibin/activin during embryogenesis. Methods: Transcripts of inhibin/activin subunits (α, β A , β B ), activin receptors (types I and II), and follistatin were detected by a reverse transcriptase–polymerase chain reaction in human reproductive cells and preembryos cultured alone or co-cultured with human endometrial cells. Results: Transcripts of α, β A , β B subunits were all detected in granulosa luteal cells, but only β A units were detected in endometrial stromal and decidualized cells. In human preimplantation embryos, none of these subunits were detected in embryos from the four-cell to the morula stage and only β A subunits were detectable in blastocyst embryos. Activin receptors were detectable in all of the studied embryos and cells. Transcripts of β A , activin receptors, and follistatin were differentially expressed in human preimplantation embryos cultured in vitro and their expressions were significantly enhanced with the presence of endometrial stromal cells. Conclusions: Our data suggest that there is a possible endometrium–embryo interaction via endometrial activins and preimplantation embryo receptors and that the embryonic expressions of these activins, their receptors, and binding proteins are dependent on embryonic stage.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1022564722353
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  • 9
    Electronic Resource
    Electronic Resource
    The correlation of summer precipitation in the southwestern U.S.A. with isotopic records of solar activity during the medieval warm period (1994)
    Springer
    Climatic change 26 (1994), S. 271-287 
    Details
    ISSN: 1573-1480
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Decreased solar activity correlates with positive cosmogenic isotope anomalies, and with cool, wet climate in temperate regions of the world. The relationship of isotope anomalies to climate may be the opposite for areas influenced by monsoonal precipitation, i.e., negative anomalies may be wet and warm. Petersen (1988) has found evidence for increased summer precipitation in the American Southwest that can be shown to be coincident with negative14C anomalies during the Medieval Warm Period. The present study compares palynological indicators of lake level for the Southwest with Petersen's data and with the14C isotope chronology. Percentages of aquatic pollen and algae from three sites within the Arizona Monsoon record greater lake depth or fresher water from A.D. 700–1350, between the Roman IV and Wolf positive isotope anomalies, thereby supporting Petersens's findings. Maximum summer moisture coincides with maximum population density of prehistoric people of the Southwest. However, water depth at a more northern site was low at this time, suggesting a climateisotope relationship similar to that of other temperate regions. Further analysis of latitudinal patterns is hampered by inadequate14C dating.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01092418
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  • 10
    Electronic Resource
    Electronic Resource
    Preparation of the endometrium for oocyte donation (1993)
    Springer
    Journal of assisted reproduction and genetics 10 (1993), S. 457-459 
    Details
    ISSN: 1573-7330
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01212931
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