RESUMO
The Qinghai-Tibet Plateau (QTP) has the largest amount of permafrost in the low and middle latitudes, making it highly susceptible to the effects of global warming. In particular, the degradation of permafrost can be intensified by anomalous amplified warming. To accurately model the hydrothermal dynamics of permafrost and its future trends, the accumulation of high-precision, long-term data for the soil thermal conductivity (STC) in the active layer is crucial. However, no previous research has systematically investigated the spatio-temporal variation in the STC on the QTP over an extended period. Therefore, this study aims to fill this gap using the XGBoost model to analyze the STC in the permafrost on the QTP from 1980 to 2020. The findings of this study provide some preliminary insights. First, areas with high variation in the STC between the freeze-thaw periods over the 40 years gradually migrated from the western region to the central region. Second, since 2015, STC in more than 90 % of the permafrost region in the thawing period has shown positive growth. While, during the freezing period, the STC also exhibited an increase over most regions of the QTP, though the western region and parts of the northeastern region exhibited a decrease. Third, the spatial center of gravity for the STC during the freezing and thawing periods from 1980 to 2020 shifted. The mean STC was larger in the eastern and northeastern regions during the freezing period and larger in the western region during the thawing period. Fourth, both alpine swamp meadow and alpine meadow exhibited a gradual increase in the STC during the freeze-thaw period from 1980 to 2020. The conclusions and data products from this study are expected to support spatiotemporal modeling of the permafrost on the QTP and assist in the prognosis for its future.
RESUMO
<p><b>OBJECTIVE</b>To explore the incidence and genotypes of glucose-6-phosphate dehydrogenase (G6PD) gene mutations among infertile patients in Shenzhen.</p><p><b>METHODS</b>DNA samples from 851 infertile patients were tested for 25 G6PD gene mutation sites using a multiplex SNaPshot assay.</p><p><b>RESULTS</b>The incidence of G6PD gene mutations among infertile patients in Shenzhen was 17.63%. Male and female abnormal rates were 15.13% and 20.09% respectively. Most of the female abnormal cases were heterozygotes. Mutations involved 11 haplotypes in 10 sites. 1311C> T/IVS-11 93T> C was the most common mutation, accounting for 72.00% (108/150) abnormal cases. Forty three cases of missense mutations were detected, including 19 cases of 1376G> T, 9 cases of 1388G> A, 5 cases of 95A> G and 871G> A/1311C> T/IVS-11 93T> C, 1 case of 202G> A, 835A> T, 1360C> T, 1376G> T and 392G> T/1311C> T/IVS-11 93T> C.</p><p><b>CONCLUSION</b>The incidence of G6PD gene mutations among infertile patients in Shenzhen was high and the mutation types were various. Therefore, the G6PD deficiency genetic screening should be performed prior to assisted reproduction. This investigated results provided valuable basic data for genetic counseling, preimplantation genetic diagnosis and prenatal diagnosis.</p>
