7,404 research outputs found
Evaluating extreme rainfall changes over Taiwan using a standardized index
The annual daily maximum precipitation (rx1day) is widely used to represent extreme events and is an important parameter in climate change studies. However, the climate variability in rx1day is sensitive to outliers and has difficulty representing the characteristics of large areas. We propose to use the probability index (PI), based on the cumulative density function (CDF) of a generalized extreme value (GEV) distribution to fit and standardize the rx1day to represent extreme event records in this study. A good correlation between the area-averaged PIs of the observed stations and those of the gridded dataset can be found over Taiwan. From the past PI records, there is no distinct trend in western Taiwan before the end of the 20th century, but a climate regime change happened during 2002 - 2003. The dual change effects from both the variance and linear trend of extreme events are identified over the northeastern and southern parts of Taiwan, along with the island's central and southern regions, showing different abrupt changing trends and intensity. The PI can also be calculated using climate projection data to represent the characteristics of future extreme changes. The climate variability of PIs on the present (ALL) and future (RCP4.5 and RCP8.5) scenarios were evaluated using the 16 Couple Model Intercomparison Projects Phase-5 models (CMIP5). The simulated present fluctuations in PIs are smaller than those of actual observations. In the 21st century, the RCP8.5 scenario shows that the PI significantly increases by 10% during the first half of the century, and 14% by the end of the century.1112Ysciescopu
On safety, pharmacokinetics and dosage of bevacizumab in ROP treatment – a review
Off-label intravitreal use of the vascular endothelial growth factor (VEGF) antibody bevacizumab for retinopathy of prematurity (ROP) increases despite lack of studies on safety, pharmacokinetics and dosage in developing individuals. Systemic absorption has been considered negligible. A literature search was performed with emphasis on potential adverse systemic effects in developing individuals
AFLP analysis on genetic diversity and population structure of small yellow croaker Larimichthys polyactis
The population genetic structure and diversity of small yellow croaker Larimichthys polyactis in the Bohai Bay, Yellow Sea and East China Sea were analyzed using amplified fragment length polymorphism(AFLP). Ninety-one individuals were collected from six locations representing three stocks of small yellow croaker. A total of 218 putative loci were detected by 3 primer combinations, 148 of which were polymorphic (67.89%). The proportion of polymorphic loci and Nei’s genetic diversity for six populations ranged from 55.34 - 60.09%, and from 0.1244 - 0.1378. AMOVA analysis and pairwise FST revealedsignificant genetic differentiation among the three groups based on the breeding migration routes and over-wintering grounds, supporting separate stocks in this species. The result shows the migratorybehavior might be an important factor which influences the genetic structure of this species. The UPGMA tree also revealed the significant geographic structure in this species. Pattern of isolation bydistance was observed in this species, indicating that significant genetic differentiation among localities of small yellow croaker might be due to the geographic distance
The peaked response of transpiration rate to vapour pressure deficit in field conditions can be explained by the temperature optimum of photosynthesis
Leaf transpiration rate (E) frequently shows a peaked response to increasing vapour pressure deficit (D). The mechanisms for the decrease in E at high D, known as the 'apparent feed-forward response', are strongly debated but explanations to date have exclusively focused on hydraulic processes. However, stomata also respond to signals related to photosynthesis. We investigated whether the apparent feed-forward response of E to D in the field can be explained by the response of photosynthesis to temperature (T), which normally co-varies with D in field conditions. As photosynthesis decreases with increasing T past its optimum, it may drive a decrease in stomatal conductance (gs) that is additional to the response of gs to increasing D alone. If this additional decrease is sufficiently steep and coupling between A and gs occurs, it could cause an overall decrease in E with increasing D. We tested this mechanism using a gas exchange model applied to leaf-scale and whole-tree CO2 and H2O fluxes measured on Eucalyptus saligna growing in whole-tree chambers. A peaked response of E to D was observed at both leaf and whole-tree scales. We found that this peaked response was matched by a gas exchange model only when T effects on photosynthesis were incorporated. We conclude that field-based studies of the relationship between E and D need to consider signals related to changing photosynthetic rates in addition to purely hydraulic mechanisms. © 2014 Elsevier B.V
Faint young Sun paradox remains
The Sun was fainter when the Earth was young, but the climate was generally
at least as warm as today; this is known as the `faint young Sun paradox'.
Rosing et al. [1] claim that the paradox can be resolved by making the early
Earth's clouds and surface less reflective. We show that, even with the
strongest plausible assumptions, reducing cloud and surface albedos falls short
by a factor of two of resolving the paradox. A temperate Archean climate cannot
be reconciled with the low level of CO2 suggested by Rosing et al. [1]; a
stronger greenhouse effect is needed.Comment: 3 pages, no figures. In press in Nature. v2 corrects typo in author
list in original submissio
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Rapid detection of BRCA1/2 recurrent mutations in Chinese breast and ovarian cancer patients with multiplex SNaPshot genotyping panels.
BRCA1/2 mutations are significant risk factors for hereditary breast and ovarian cancer (HBOC), its mutation frequency in HBOC of Chinese ethnicity is around 9%, in which nearly half are recurrent mutations. In Hong Kong and China, genetic testing and counseling are not as common as in the West. To reduce the barrier of testing, a multiplex SNaPshot genotyping panel that targeted 25 Chinese BRCA1/2 mutation hotspots was developed, and its feasibility was evaluated in a local cohort of 441 breast and 155 ovarian cancer patients. For those who tested negative, they were then subjected to full-gene testing with next-generation sequencing (NGS). BRCA mutation prevalence in this cohort was 8.05% and the yield of the recurrent panel was 3.52%, identifying over 40% of the mutation carriers. Moreover, from 79 Chinese breast cancer cases recruited overseas, 2 recurrent mutations and one novel BRCA2 mutation were detected by the panel and NGS respectively. The developed genotyping panel showed to be an easy-to-perform and more affordable testing tool that can provide important contributions to improve the healthcare of Chinese women with cancer as well as family members that harbor high risk mutations for HBOC
Study on electrochemical properties of FeS2 in room temperature molten salt
In this paper, FeS2 electrodes have been prepared by using reactive codeposition methods. The electrochemical performances of FeS2 were studied in LiCl buffer Lewis neutral 1-methyl-3-ethylimidazolium chloride (MeEtImCl)/AlCl3 (room temperature molten salt) melts. The results show that FeS2 electrodes possess reversible Li ion intercalation and deintercalation behavior in the first step two electron processes.published_or_final_versio
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