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1. chinaXiv:202005.00089 [pdf]

Uncertainty assessment of potential evapotranspiration in arid areas, as estimated by the Penman-Monteith method

HUA Ding; HAO Xingming; ZHANG Ying; QIN Jingxiu
Subjects: Biology >> Botany >> Applied botany

The Penman-Monteith (PM) method is the most widely used technique to estimate potential worldwide evapotranspiration. However, current research shows that there may be significant errors in the application of this method in arid areas, although questions remain as to the degree of this estimation error and how different surface conditions may affect the estimation error. To address these issues, we evaluated the uncertainty of the PM method under different underlying conditions in an arid area of Northwest China by analyzing data from 84 meteorological stations and various Moderate Resolution Imaging Spectroradiometer (MODIS) products, including land surface temperature and surface albedo. First, we found that when the PM method used air temperature to calculate the slope of the saturation vapor pressure curve, it significantly overestimated the potential evapotranspiration; the mean annual and July–August overestimation was 83.9 and 36.7 mm, respectively. Second, the PM method usually set the surface albedo to a fixed value, which led to the potential evapotranspiration being underestimated; the mean annual underestimation was 27.5 mm, while the overestimation for July to August was 5.3 mm. Third, the PM method significantly overestimated the potential evapotranspiration in the arid area. This difference in estimation was closely related to the underlying surface conditions. For the entire arid zone, the PM method overestimated the potential evapotranspiration by 33.7 mm per year, with an overestimation of 29.0 mm from July to August. The most significant overestimation was evident in the mountainous and plain non-vegetation areas, in which the annual mean overestimation reached 5% and 10%, respectively; during July, there was an estimation of 10% and 20%, respectively. Although the annual evapotranspiration of the plains with better vegetation coverage was slightly underestimated, overestimation still occurred in July and August, with a mean overestimation of approximately 5%. In order to estimate potential evapotranspiration in the arid zone, it is important that we identify a reasonable parameter with which to calibrate the PM formula, such as the slope of the saturation vapor pressure curve, and the surface albedo. We recommend that some parameters must be corrected when using PM in order to estimate potential evapotranspiration in arid regions.

submitted time 2020-05-31 From cooperative journals:《Journal of Arid Land》 Hits11045Downloads712 Comment 0

2. chinaXiv:201908.00118 [pdf]

Five new species of Arvicolinae and Myospalacinae from the?Late Pliocene?Early Pleistocene of Nihewan Basin

ZHENG Shao-Hua; ZHANG Ying-Qi; ?CUI Ning
Subjects: Biology >> Zoology

The Nihewan Basin has been well known for its Cezonoic fossiliferous fluviolacustrine deposits and paleolithic sites for almost a century. There have been considerable research efforts devoted to the understanding of the geology, chronology, and stratigraphy of this?complex of sedimentary body. The current fundamental problem lies in the chronological aspect?of the Nihewan Beds. Arvicolinae and Myospalacinae are two groups of rodents characterized?by rapid evolutionary rates and quantifiable evolutionary trends, and hence particularly helpful?in Late Cenozoic biostratigraphic correlations. Therefore, we briefly describe three new species?of Arvicolinae and two new species of Myospalacinae that mainly came from the selected?sections in the Nihewan Basin. Hopefully, they would contribute towards the establishment of the?biostratigraphic framework of the Nihewan Basin and provide new evidence on the chronological?understanding of the Nihewan Beds from an evolutionary point of view.

submitted time 2019-08-26 From cooperative journals:《古脊椎动物学报》 Hits7794Downloads737 Comment 0

3. chinaXiv:201711.02434 [pdf]

A?Machine?Learning?Assisted,?Label-free,?Non-invasive?Approach?for?Somatic?Reprogramming?inInduced?Pluripotent?Stem?Cell?Colony?Formation?Detection?and?Prediction

Fan, K?(Fan, Ke); Zhang, S?(Zhang, Sheng); Zhang, Y?(Zhang, Ying); Lu, J?(Lu, Jun); Holcombe, M?(Holcombe, Mike); Zhang, X?(Zhang, Xiao)
Subjects: Biology >> Ecology

During cellular?reprogramming, the mesenchymal-to-epithelial transition is accompanied by changes?in?morphology, which occur prior to iPSC?colony?formation. The current?approach?for?detecting morphological changes associated with?reprogramming?purely relies on human experiences, which involve intensive amounts of upfront training, human error with limited quality control and batch-to-batch variations. Here, we report?a?time-lapse-based bright-field imaging analysis system that allows us to implement?a?label-free,?non-invasive?approach?to measure morphological dynamics. To automatically analyse and determine iPSC?colony?formation,?a?machine?learning-based classification, segmentation, and statistical modelling system was developed to guide?colony?selection. The system can detect and monitor the earliest cellular texture changes after the induction of?reprogramming?in?human?somatic?cells on day 7 from the 20-24 day process. Moreover, after determining the?reprogramming?process and iPSC?colony?formation?quantitatively,?a?mathematical model was developed to statistically predict the best iPSC selection phase independent of any other resources. All the computational?detection?and?prediction?experiments were evaluated using?avalidation dataset, and biological verification was performed. These algorithm-detected colonies show no significant differences (Pearson Coefficient)?in?terms of their biological features compared to the manually processed colonies using standard molecular approaches.

submitted time 2017-11-17 Hits719Downloads436 Comment 0

4. chinaXiv:201605.01244 [pdf]

Structural Insights into the Molecular Recognition between Cerebral Cavernous Malformation 2 and Mitogen-Activated Protein Kinase Kinase Kinase 3

Wang, Xiaoyan; Hou, Yanjie; Deng, Kai; Zhang, Ying; Wang, Da-Cheng; Ding, Jingjin; Wang, Xiaoyan; Deng, Kai
Subjects: Biology >> Biophysics >> Biochemistry & Molecular Biology

Cerebral cavernous malformation 2 (CCM2) functions as an adaptor protein implicated in various biological processes. By interacting with the mitogen-activated protein kinase MEKK3, CCM2 either mediates the activation of MEKK3 signaling in response to osmotic stress or negatively regulates MEKK3 signaling, which is important for normal cardiovascular development. However, the molecular basis governing CCM2-MEKK3 interaction is largely unknown. Here we report the crystal structure of the CCM2 C-terminal part (CCM2ct) containing both the five-helix domain (CCM2ct(s)) and the following C-terminal tail. The end of the C-terminal tail forms an isolated helix, which interacts intramolecularly with CCM2ct(s). By biochemical studies we identified the N-terminal amphiphilic helix of MEKK3 (MEKK3-n(helix)) as the essential structural element for CCM2ct binding. We further determined the crystal structure of CCM2ct(s)-MEKK3-n(helix) complex, in which MEKK3-n(helix) binds to the same site of CCM2ct(s) for CCM2ct intramolecular interaction. These findings build a structural framework for understanding CCM2ct-MEKK3 molecular recognition.

submitted time 2016-05-11 Hits1074Downloads557 Comment 0

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