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The Science of Nature - 相似文献
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Dr J. L. Carrasco Juan A. Otero Gómez M. C. Vilar Mesa J. L. García Miranda J. M. Troyano Luque O. Morales Ruiz J. Parache Hernández 《黑龙江环境通报》1989,9(6):443-445
A dicentric X chromosome was found in a female fetus during cytogenetic studies performed on amniotic cells. Blood samples from the parents showed normal karyotypes and the pregnancy was terminated. The mechanism for the formation of this ‘de novo’ rearrangement is discussed. 相似文献
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D. Costa A. Borrell E. Margarit A. Carrió A. Soler I. Balmes X. Estivill A. Fortuny 《黑龙江环境通报》1995,15(2):141-148
Fluid from pleural effusion (n=2) and cystic hygroma (n=7) was obtained from eight fetuses, between 13 and 32 weeks of pregnancy at the time when a conventional prenatal diagnosis procedure was carried out. As these fluids contain lymphocytes, they were processed like peripheral blood. A karyotype was obtained in 4 days in both cases of pleural effusion and in four out of seven samples of cystic hygroma. An abnormal karyotype was detected in three of the four samples of cystic hygroma: two trisomies 21 and a monosomy X. Different parameters were evaluated in order to predict the feasibility of obtaining a cytogenetic diagnosis. Our data showed that if the amount of fluid obtained was ⩾4 ml and the initial lymphocyte count (ILC) was >0.2 × 106 cells/ml, a cytogenetic diagnosis was possible from an initial concentration of cultured lymphocytes )ICCL) of >0.06 × 106 cells/ml. 相似文献
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Catherine Potvin Petra Tschakert Frédéric Lebel Kate Kirby Hector Barrios Judith Bocariza Jaime Caisamo Leonel Caisamo Charianito Cansari Juan Casamá Maribel Casamá Laura Chamorra Nesar Dumasa Shira Goldenberg Villalaz Guainora Patrick Hayes Tim Moore Johana Ruíz 《Mitigation and Adaptation Strategies for Global Change》2007,12(8):1341-1362
This paper is part of a two-year study to investigate the feasibility of initiating a Clean Development Mechanism (CDM) project
in an indigenous community of Eastern Panamá, Ipetí-Emberá. We use participatory mapping and matrices as well as household
surveys to develop a land-use/land-cover baseline scenario and examine the role of local participation in assessing land-use
change. In Ipetí, land-use change has not occurred in a linear way over the last decades, and our data unveils socio-economic
factors as potential key drivers of change. The concordance that we observed between geographic information and individual
and collective perceptions of land-use change substantiates the possibility of using local knowledge in the establishment
of baseline data for CDM projects. Our calculations suggest that the total carbon (C) stocks in the Tierra Colectiva (TC) of Ipetí-Emberá in 2004 represents a 47% reduction from the estimated C stock at the onset of settlement in the early
1970’s. Results from the participatory assessments predict that, in 2024 and in absence of a CDM project, the C stocks will
decline from 301,859 t C in 2004 to 155,730 t C, which constitutes a reduction of 52%. The scenario with CDM estimates C stocks
of 305,853 t C for 2024, a value slightly superior to the 2004 value. In the TC there is ground to believe that cattle ranching
is likely to become an ever more important activity as the population is young and growing and cannot easily move elsewhere.
Forests tend to be cleared for cultivation while pastures are established on short fallows. Our baseline scenario underlines
the potential for a CDM project to make a significant difference in the future C stocks of this landscape. 相似文献
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Kevin Summers Leroy Folmar Miriam Rodón-Naveira 《Environmental monitoring and assessment》1997,47(3):275-301
As part of the Environmental Monitoring and Assessment Programin 1991, the field efficacy of six research indicators wasexamined in the estuarine systems of the Gulf of Mexico. Theutility of these indicators was tested by examining thoseresponses at both ends of multiple environmental gradients;namely, under minimally impacted conditions (reference) andheavily impacted conditions (by hypoxia, industrialdischarges, agricultural runoff). In addition, the geographiceffects of location (east and west of the Mississippi River)were examined. Numbers and frequencies of pathologies,abundance of splenic macrophage aggregates, and vertebralabnormalities showed response patterns that suggest widerfield testing along full gradients rather than simply theextremes of the gradient are warranted. Selected bloodproteins showed some promise but logistical constraints inestuarine environments may limit its utility. Concentrationsof selected organic compounds in bile showed no differences inthis study between references and contaminated sites.Molecular bioindicators are discussed with regard to theirpotential utility as indicators of ecosystem conditions. Ofthese potential indicators, the use of vitellogenin assays asa measure of reproductive impairment and frequency of shelldisease in selected crustaceans as an indicator ofimmunological aberrations deserve further examination. 相似文献