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The sea surface temperature (SST) is not only a crucial external factor in the evolution of the atmosphere, but also a primary factor and premonition signal used in climate prediction. It is challenging to obtain a precise SST for generating accurate initial and boundary conditions in numerical models. This study employs a machine learning approach, that is, a convolutional neural network (CNN) algorithm, to predict SST on a seasonal scale. In particular, the subsurface ocean temperature (OT) and ocean salinity (OS) at depths of 5.02, 15.08, 25.16, 35.28, 45.45 and 76.55 m were used as training factors in developing a CNN prediction model. The results indicate that subsurface OT and OS can persist for 6 months or longer, with a maximum persistence of up to 12 months. Using the CNN prediction model, the SST can be reliably predicted 6 months in advance in most cases. The predicted SST has a mean bias of approximately 0–0.8 K on the globe. The bias is small (below 0.5 K) in the open ocean. The root mean square errors (RMSEs) of hindcasting for Interdecadal Pacific Oscillation, North Atlantic Oscillation (NAO) and Atlantic Multidecadal Oscillation indices are all less than 1.0 K. Specifically, the RMSE for El Niño prediction is less than 0.5 K. This study provides a viable method for establishing initial and boundary conditions for climate prediction. [ABSTRACT FROM AUTHOR]

In this paper, the effects of spring soil moisture (SM) anomalies in the mid‐latitudes on the atmospheric circulation in summer over the Northern Hemisphere (NH) are investigated. The results show that there are two regions of maximum interannual variability of the spring SM in the mid‐latitudes, which are located in central North America (CNA) and Europe and central Asia (ECA). In addition, the interannual variation of spring SM anomalies between CNA and ECA exhibits a seesaw pattern. The CNA–ECA seesaw pattern of the spring SM anomalies leads to the surface heat anomalies having opposite phases in CNA and ECA from spring to summer, which subsequently cause the opposite phase of baroclinicity anomalies in spring. The anomalous meridional temperature advections in spring cause the baroclinicity anomalies to have the same phase around CNA and ECA in summer. Corresponded with the same phase of baroclinicity anomalies, the anomalous centers of the stationary Rossby wave train (RWT) and Rossby wave source (RWS) have the same phase in CNA and ECA in summer. Through analysis of the vorticity budgets, the maintenance mechanism of the RWT in summer is considered as a positive feedback that anomalous meridional winds characterized by a RWT, transport the mean absolute vorticity and subsequently lead to an anomalous RWS, which in turn maintains the stationary RWT. Numerical experiments further demonstrate the effects of CNA–ECA seesaw pattern of spring SM anomalies on stationary RWT and RWS in summer. Plain Language Summary: The interannual variation of soil moisture (SM) anomalies in mid‐latitudes exhibits a seesaw pattern in central North America (CNA) and Europe and central Asia (ECA). When spring SM anomalies are negative in CNA and positive in ECA, positive (negative) sensible heat flux anomalies are observed in CNA (ECA) while negative (positive) latent heat flux anomalies are observed in CNA (ECA) from spring to summer, or vice versa. Influenced by surface heat anomalies, baroclinicity anomalies exhibit a seesaw pattern in CNA and ECA in spring, and have same phase in CNA and ECA in summer due to anomalous meridional temperature advections. The baroclinicity anomalies in CNA and ECA in summer contribute to the same variation of wave‐flow interactions. The Rossby wave train (RWT) induced and maintained by CNA–ECA seesaw pattern of spring SM anomalies in spring can be maintained by its meridional transportation of the mean absolute vorticity in summer. Apparently, spring SM anomalies in the middle latitudes can persistently influence the large‐scale atmospheric circulations over the Northern Hemisphere by maintaining RWT. Key Points: Seesaw pattern of spring soil moisture anomalies in central North America (CNA) and Europe and central Asia (ECA)Baroclinicity anomalies change from opposite to same phase in CNA and ECA during the transition from spring to summerRossby wave train induced by spring CNA–ECA seesaw pattern is maintained by its meridional mean absolute vorticity transportation in summer [ABSTRACT FROM AUTHOR]

Water‐heat transport in frozen soil influences the energy and water exchanges between land and atmosphere. However, frozen soil water‐heat transport simulation biases remaining in land surface model (LSM) result in uncertainties of climate model performance. In this study, the biases of the Noah with multi‐parameterization (Noah‐MP) land surface model in simulating soil water‐heat transport in freeze‐thaw (FT) process were investigated. On this basis, three parameterizations that were effective in other LSMs were implemented into Noah‐MP to optimize its performance. The results show that Noah‐MP still exhibits biases in simulating soil temperature and moisture in FT process. Even with various combinations of current parametrizations, the soil water–heat coupling relationship simulated by Noah‐MP does not align with observations. Nevertheless, the implementation of a virtual temperature parameterization, a liquid water‐dependent soil permeability parameterization, and modifications to soil hydraulic and thermal properties through considering the influences of organic matter and gravel, led to improvements in soil moisture and temperature simulations during both completely frozen and thawing periods. These enhancements resulted in a reduction of bias by approximately 20%–50%, and the simulated soil water–heat coupling relationship with implemented parameterizations closely matches observations. Global simulations further validate the improvements brought about by the implemented frozen‐thawing parameterizations in Noah‐MP. Plain Language Summary: Simulation biases in frozen soil water‐heat transport can introduce uncertainties in climate modeling and predictions for cold regions. How to improve the frozen soil hydrothermal parameterization is still an urgent issue. In this study, to optimize the frozen‐thawing parameterizations in Noah‐MP, a virtual temperature parameterization was implemented to redefine the phase change criteria, a liquid water‐dependent frozen soil permeability parameterization was adopted to recalculate the hydraulic conductivity, and influences of organic matter and gravel on soil hydraulic and thermal properties were considered in Noah‐MP. Through these enhancements, simulations of soil moisture and temperature during completely frozen and thawing periods were effectively improved. The findings of this study underscore the importance of frozen‐thawing parameterizations in land surface models for simulating water‐heat transport in frozen soil, which provide a potential way to improve the climate simulations in cold regions. Key Points: Noah‐MP with current frozen soil parameterizations combinations still have biases in simulating water‐heat transport in the FT processThe soil water‐heat coupling relationship simulated by Noah‐MP is not consistent with observation during soil thawing periodSimulations of soil moisture and temperature were effectively improved by optimized parameterizations [ABSTRACT FROM AUTHOR]

The fragile ecology of the Yellow River basin (YRB) is vulnerable to global warming and human activities. As the second largest river in China, the YRB covers the subhumid, semi‐arid, arid and alpine climate zones, with considerably spatial differences in vegetation cover (VC), thus demonstrating substantial variations in response to climate change. In this study, characteristics of VC variations in different climate zones of the YRB during 1982–2019 were analysed, impacts of climate change and human activities on VC variations were identified, and possible VC variations in the future were projected under different climate scenarios. Results show that NDVI in the YRB significantly increased at a rate of 2.3 × 10−3 year−1 from 1982 to 2019, especially in the middle reaches of the YRB. Temperature is the main driver of VC variations in the source region of the YRB (alpine zone), wherein the warming trend contributes to the greening. The internal variability of VC is also influenced by temperature, with a marginal effect of precipitation minus evaporation (P − E). In the middle and lower reaches of the YRB consisting of arid, semi‐arid, and subhumid zones, VC benefited only from the warming trend and had a less relationship with the internal variability of temperature, whereas the internal variability of VC was influenced by P − E and had a weaker relationship with the P − E trend. Contributions of climate change to VC variations in the source region and middle and lower reaches of the YRB are approximately 62%, 42%, and 27%, respectively. Human activities considerably impact the ecological environment but mostly play a positive role. In the future, VC will increase in the YRB, especially under the SSP5‐8.5 scenario, and VC reveals the most prominent changes in the lower reaches. This study suggests that climate change might be favourable to VC in YRB, and emphasizes that human activities should adapt to climate change in an orderly manner. [ABSTRACT FROM AUTHOR]

Soil moisture can be an important preceding signal in seasonal precipitation prediction because of its persistence and influence on the energy and water balance between land and atmosphere. The thawing process of frozen ground on the Tibetan Plateau (TP) during spring makes it difficult to accurately simulate soil variables (e.g., soil moisture and temperature) due to defective parameterizations in numerical models during spring. In this study, we investigate the effectiveness of soil moisture correction using an indirect nudging scheme to simulate the coupling between spring soil moisture and the subsequent precipitation with an advanced research version of the weather research and forecasting (WRF) model. The results without assimilation show that extreme cold and dry land surface states during spring cause a large bias in the spatial pattern of summer precipitation over almost the entire TP. However, the experiments with indirect assimilation in spring show that the spatial pattern of summer precipitation improved significantly. This comparison emphasizes the importance of correcting the spring soil moisture during the freeze–thaw period to significantly adjust the heat and water vapour exchange between the land and atmosphere. Additionally, changes in the circulation of the subtropical–tropical jet, vertical ascent, and region‐related moisture recycling can support an active convection environment over the eastern TP, thereby increasing summer precipitation. Furthermore, the pattern shift in water vapour convergence in summer highlights the regional horizontal transportation of water vapour. The differences between experiments with and without deep‐soil temperature nudging illustrate the significance of soil temperature in soil moisture simulation in the freeze–thaw process. More so, the deep‐soil temperature nudging scheme requires in‐depth studies to correct its variation and quantify its degree of impact on soil moisture. [ABSTRACT FROM AUTHOR]

The impact of soil moisture (SM) and precipitation coupling (SM‐P‐C) on the subsequent climate at daily to seasonal scales over the Tibetan Plateau (TP) is a critical issue. In this study, the spring SM and summer precipitation coupling (SSM‐SP‐C) were investigated using multi‐reanalysis and validated with 13 global climate models (GCMs) in Coupled Model Intercomparison Project Phase 5, and its relationship with the wet bias in GCMs was explored. The results reveal that SSM‐SP‐C shows an east–west reversal, with positive coupling in eastern and central TP and negative coupling in the western TP. The spring surface sensible heat has significantly negative effects on the strength of SSM‐SP‐C in eastern and central TP, while significantly positive effects in western TP; whereas, the SM shows the reverse effects in eastern and western TP. The concurrent SM‐P‐C over TP shows a positive trend from spring to summer, but coupling strength has significant spatial differences. The 13 GCMs ensemble mean underestimates the positive SSM‐SP‐C in eastern TP and can't reproduce the negative SSM‐SP‐C in western TP. The wet bias of summer precipitation is significantly associated with the model's failure in capturing SSM‐SP‐C. This study highlights the impacts of SM‐P‐C on subsequent climate in the alpine cold region and provides a potential way for reducing precipitation biases by improving SM‐P‐C parameterizations in GCMs. Key Points: Spring soil moisture and summer precipitation coupling (SSM‐SP‐C) shows an east‐west reversal, with positive coupling in eastern and central Tibetan Plateau (TP) and negative coupling in the western TPThe SSM‐SP‐C has elevation‐dependent variations, the maximum coupling strength appears over regions with 3–4 km elevationWet bias of summer precipitation is significantly associated with the model's failure in capturing SSM‐SP‐C [ABSTRACT FROM AUTHOR]

The sudden turn from drought to flood (STDF) is an extreme climate event that frequently occurs over the middle and lower reaches of the Yangtze River Basin (MLYR) in China. This study investigates the role of the intraseasonal oscillation (ISO) in a STDF event in 2011 over the MLYR and analyses its dynamic characteristics. A wavelet analysis of the rainfall evolution shows that there are two ISO modes (10–20 days and 30–60 days) during the STDF event. When rainfall turns from drought to flood, both ISO modes of rainfall simultaneously convert from the negative phase to the positive phase. Further investigation on the two intraseasonal time scales illustrates that a meridionally‐propagated Rossby wave train (RWT) propagates northward along the eastern China, and meets a zonally‐propagated RWT from the North Atlantic to the North Pacific over the MLYR. The interaction of the two RWTs above is the key factor that causes the STDF event in 2011 over the MLYR. [ABSTRACT FROM AUTHOR]

After a tropical storm makes landfall, its vortex interacts with the surrounding environment and the underlying surface. It is expected that diurnal variation over land will affect storm structures. However, this has not yet been explored in previous studies. In this paper, numerical simulation of postlandfall Tropical Storm Bill (2015) is conducted using a research version of the NCEP Hurricane Weather Research and Forecasting (HWRF) model. Results indicate that during the storm's interaction with midlatitude westerlies over the Great Plains, the simulated storm with the SLAB land‐surface scheme is stronger, with faster eastward movement and attenuation, and more asymmetric structures than that with the NOAH land‐surface scheme. More symmetric structures correspond with a slower weakening and slower eastward movement of the storm over land. Further diagnoses suggest an obvious response of the storm's asymmetric structures to diurnal effects over land. Surface diabatic heating in the storm environment is important for the storm's symmetric structures and intensity over land. Specifically, during the transition from nighttime to daytime, the evident strengthening of convective instability, atmospheric baroclinicity, and the lateral advection of high θe air in the storm environment, associated with the rapid increase in surface diabatic heating, are conducive to the development of vertical vorticity and storm‐relative helicity, thus contributing to the maintenance of the storm's symmetric structures and intensity after landfall. Key Points: An evident response of the storm's asymmetric structures to diurnal effects over land are revealedSurface diabatic heating in the storm environment is important for the evolution of the storm's symmetric structures and intensity over landEffects of surface diabatic heating storm's symmetric structure and intensity over land are mainly manifested in storm's upshear quadrants [ABSTRACT FROM AUTHOR]

This study used a multi‐model ensemble (MME) simulation to project changes in extreme precipitation (EP) over the next century based on four relevant indexes (R95P, FRE, total precipitation [PRCPTOT] and PPER) during the monsoon period (May–September) over eastern Asia. The ensemble model was built from three global climate models from the Coupled Model Inter‐comparison Project Phase 5. The results indicate that the MME results can reproduce observations of the spatial distribution characteristics of EP indexes in eastern Asia. Compared with the reference period of 1986–2005, the EP (R95P), PRCPTOT and the ratio of EP to PRCPTOT (PPER) in eastern Asia will increase during the monsoon period under the three emission scenarios in three durations (the early period: 2020–2039, middle period: 2050–2069 and late period: 2080–2099) throughout the 21st century. This feature is especially strong in southeast China and the Malay Islands. Meanwhile, the variation in the frequency of EP events (FRE) has prominent regional differences, including a decrease in the Yellow River Basin and the Indochina Peninsula and an increase in southeast China. All projected increasing were most significant under high emissions (RCP8.5). This study also suggests that EP would not generally increase in frequency but rather in intensity. With an increase in emissions concentration, the temperature threshold at which EP occurs is likely to rise, so the EP might need triggered by the higher temperatures. [ABSTRACT FROM AUTHOR]

Objective: To explore the effects of patellectomy on the bony and cartilaginous morphology of the trochlear groove in growing rabbits. Methods: Forty‐eight 4‐week‐old New Zealand white rabbits were randomly assigned to two groups. The control group underwent a sham surgical procedure, whereas the patellectomy group underwent patella excision surgery. Half of the rabbits in each group were sacrificed 3 months postoperatively; the rest were sacrificed 6 months postoperatively. Hematoxylin and eosin staining was performed on collected samples. Measurements included the bony and cartilaginous sulcus angles of the trochlear groove. In addition, the thickness of the articular cartilage at the deepest sulcus position (central thickness) and at the mid‐position of the medial and lateral facets was measured and compared between groups. Results: Three months after surgery, histological images revealed significant differences between the control group and the patellectomy group in cartilaginous sulcus angle (144.2° ± 1.5° vs 151.9° ± 2.4°, respectively; P < 0.001). No obvious difference in bony sulcus angle was found between the groups. Six months after surgery, significant between‐group differences were observed in cartilaginous sulcus angle (136.3° ± 2.5° in control group vs 160.7° ± 3.0° in patellectomy group, P < 0.001) and bony sulcus angle (136.2° ± 2.2° in control group vs 160.4° ± 2.6° in patellectomy group, P < 0.001). However, there were no significant intra‐group differences between cartilaginous and bony sulcus angles in either group. Three months after surgery, significant between‐group differences were detected in articular cartilage thickness at the three different positions (medial facet: 324.3 ± 14.0 μm in control group vs 391.7 ± 98.8 μm in patellectomy group, P = 0.029; central position: 362.1 ± 13.6 μm in control group vs 730.3 ± 76.8 μm in patellectomy group, P < 0.001; lateral facet: 324.6 ± 12.7 μm in control group vs 358.5 ± 38.7 μm in patellectomy group, P = 0.009). No between‐group differences in cartilage thickness were found at 6 months. Conclusions: Abnormal mechanical stress (patellectomy) during a rabbit's development can cause flattening of the femoral trochlear cartilage, followed by changes in the subchondral osseous layer. Abnormal mechanical stress is a crucial factor in the development of trochlear groove dysplasia. [ABSTRACT FROM AUTHOR]

Ural blocking (UB) event is an important large‐scale weather system dominating cold waves in East Asia. This paper investigates the thermal‐dynamical variation characteristics associated with UB evolution via 32 UB events in winter during 1979–2016. The results show that transport of stationary heat and momentum changes prominently from 3 and 6 days before and after UB establishment. Specifically, on 3 days prior to the UB event establishment, an apparent convergence of stationary heat flux ({v*T*}), which can extend from lower‐middle troposphere to the tropopause, is observed at around 60°N in the Urals region. The diagnosis shows that the convergence of stationary heat flux weakens the meridional temperature gradient (−∂T∂y) and thermal wind, and thus the zonal westerly weakens. The convergence of ({v*T*}) also support formation of the warm centre structure of UB event. Meanwhile, convergence of momentum flux reverses to be a divergence in the Urals region (60°N), which contributes to decrease of the zonal wind. The heat and momentum flux reduce the intensity of the westerly and are beneficial for the establishment of UB event. Along with UB event establishment, the convergence of stationary heat flux weakens, and the divergence of momentum flux strengthens, accompanying with decrease of wind speed at middle latitudes and maintaining of the UB event. Six days later, the convergence of stationary heat flux disappears and divergence of momentum flux changes to be convergence and then the UB event collapses. Further analyses also suggest that the polar front jet (PFJ) enhances (weakens) coincidently before (after) the establishment of UB, which is attributed to the strengthening (weakening) of the convergence of ({u*v*}) around 70°N. [ABSTRACT FROM AUTHOR]

There is general uncertainty about the representation of clouds and convective precipitation in almost all models. Efforts to handle the convective parametrization scheme (CPS) in the grey zone (∼1–5 km horizontal grid spacing) are still imperative to the community, especially for the case of weakly forced deep convection. This study proposes a new convective adjustment time‐scale (τ) for the Kain–Fritsch eta (KFeta) scheme in the Weather Research and Forecasting (WRF) model at high resolution, which differs from the current scale‐aware function. The validation was made in three cases of weakly forced deep convection over the Tibetan Plateau. The results confirmed that modifying τ improves the simulation performance. In particular, the modified τ improved the simulated precipitation pattern, horizontal scale and intensity over the original scheme, which could be attributed to the enhanced rate at which convective instability generated by external factors (e.g. large‐scale advection and surface turbulent fluxes) is removed by the parametrized convection. When τ is appropriately chosen, the CPS can be implemented in high‐resolution simulations. [ABSTRACT FROM AUTHOR]

Frequently occurring extreme precipitation events have caused severe disasters over the years, especially in monsoon regions such as Southeast Asia and East China (SAEC). Understanding the characteristics of extreme precipitation in SAEC on annual and monthly scales is essential for improving predictions extreme precipitation events. In this study, the temporal and spatial distribution characteristics of extreme precipitation events in the summer half‐year (May to September) are analysed from 1986 to 2015 over SAEC, based on the threshold of extreme precipitation defined with a percentile method and the daily precipitation data from 190 meteorological stations. The results indicate that the precipitation in annual and summer half‐year over the SAEC are mainly attributed to extreme precipitation events. The frequency and amount of extreme precipitation are significant in South China and Southeast Asia, the Yangtze River region, and North China; specifically, the duration of high extreme precipitation events are longer in South China and Southeast Asia compared to those in other areas. The frequency and amount of extreme precipitation increased in South China, Southeast Asia and North China while have a decreasing trend in Yangtze River basin. Further investigation of the possible relationship between summer extreme precipitation events and the activity of the Asian summer monsoon (ASM) indicate that, the movements of extreme precipitation are consistent with the northward advance and southward withdrawal of summer monsoon and are commonly located in the vicinity of the front of the ASM. This phenomenon suggests that summer extreme precipitation events over SAEC are closely connected with ASM activity and may be the products of ASM. The spatial distribution of (a) mean annual extreme precipitation (R95P), (b) mean annual extreme precipitation frequency, (c) annual total precipitation (PRCPTOT) and (d) the proportion of annual extreme precipitation to annual precipitation (PPER) over Southeast Asia and East China during 1986–2015. The black dots denote geographic distribution of 190 stations in Southeast Asia and East China. [ABSTRACT FROM AUTHOR]

Abstract: Land surface models (LSMs) have developed significantly over the past few decades, with the result that most LSMs can generally reproduce the characteristics of the land surface. However, LSMs fail to reproduce some details of soil water and heat transport during seasonal transition periods because they neglect the effects of interactions between water movement and heat transfer in the soil. Such effects are critical for a complete understanding of water‐heat transport within a soil thermohydraulic regime. In this study, a fully coupled water‐heat transport scheme (FCS) is incorporated into the Community Land Model (version 4.5) to replaces its original isothermal scheme, which is more complete in theory. Observational data from five sites are used to validate the performance of the FCS. The simulation results at both single‐point and global scale show that the FCS improved the simulation of soil moisture and temperature. FCS better reproduced the characteristics of drier and colder surface layers in arid regions by considering the diffusion of soil water vapor, which is a nonnegligible process in soil, especially for soil surface layers, while its effects in cold regions are generally inverse. It also accounted for the sensible heat fluxes caused by liquid water flow, which can contribute to heat transfer in both surface and deep layers. The FCS affects the estimation of surface sensible heat (SH) and latent heat (LH) and provides the details of soil heat and water transportation, which benefits to understand the inner physical process of soil water‐heat migration. [ABSTRACT FROM AUTHOR]

Ultraconserved regions (UCRs) are non-protein coding gene sequences that are strictly conserved across among different species. Emerging evidence demonstrates that transcribed ultraconserved regions (TUCRs) encoding noncoding RNAs serve as regulators of gene expression. In recent decades, increasing evidence implicates the involvement of UCRs in carcinogenesis. The role of TUC.338 in cervical cancers was an oncogene in previous studies. Until now, the role of TUC.338 in colorectal cancers remains undefined. This study revealed that TUC.338 is significantly up-regulated in colorectal cancers (CRC) tissue and CRC cell lines, and the up-regulated TUC.338 is associated with lymph node metastasis. Transfection with small interfering RNA (siRNA) markedly inhibited cell migration and invasion in SW480 and HCT116 colorectal cancer cell lines. TIMP-1 was demonstrated to be negatively regulated by TUC.338 at the posttranscriptional level, via a specific target site within the 3' untranslated region by dual-luciferase reporter assay. The expression of TIMP-1 was also observed to inversely correlate with TUC.338 expression in CRC tissues. Over-expression of TIMP-1 with migRI-TIMP-1-GFP inhibited CRC cell migration and invasion and down-regulates MMP9, resembling that of TUC.338-siRNA. Thus, these findings suggested that TUC.338 acts as a novel oncogene by targeting the TIMP-1 gene thus promoting colorectal cancer cell migration and invasion. [ABSTRACT FROM AUTHOR]

ABSTRACT An empirical orthogonal function ( EOF) analysis of upper troposphere thickness between 200 and 300 hPa reveals a north-south dipole over the Asian-Australian (A-A) monsoon region in boreal winter (December-February, DJF). The dipole centres are located above the exit of the polar jet in the north and over the equatorial 'warm pool' in the south. The structure is defined as the Asia-Australia dipole ( AAD) in this study. Its intensity reflects the temperature gradient and interaction of the circulation between the Southern and Northern Hemispheres, as well as illustrating the relations between the polar front jet and the 'warm pool' climate. The results show that the AAD strongly affects the climate in the A-A region after excluding the El Niño Southern Oscillation ( ENSO) signal in the upper troposphere. The precipitation in the western Eurasian continent and the surface temperature in most of the A-A region are closely linked through the AAD, while the ENSO signal in the upper troposphere influences the climate at lower latitudes. Furthermore, the AAD index ( AADI) signal can be found in most 5th Phase of the Coupled Model Intercomparison Project ( CMIP5) model results. Thus, both observational analysis and modelling results demonstrate that the AAD is an important structure in the upper troposphere, largely reflecting differences in the upper troposphere between the Northern and Southern Hemispheres. [ABSTRACT FROM AUTHOR]

ABSTRACT The interaction of hydroxyethyl starch 130/0.4 (Voluven) with human serum albumin (HSA) has been investigated by fluorescence (steady state and synchronous), Fourier transforms infrared (FT-IR), and circular dichroism (CD) spectroscopies. Analysis of the fluorescence quenching data of HSA by Voluven using the Stern-Volmer method revealed the formation of 1:1 ground-state complex. Evaluation of binding parameters and binding energy indicated that the binding reaction was exothermic. On the basis of fluorescence measurements, it was concluded that electrostatic forces play a crucial role in stabilizing the complex. The binding distance was calculated by using Förster resonance energy transfer (FRET) theory. The conformational changes of HSA were obtained qualitatively as well as quantitatively using synchronous fluorescence, FT-IR, and CD. The HSA underwent partial unfolding in the presence of Voluven. [ABSTRACT FROM AUTHOR]

Long noncoding RNAs (Lnc RNAs) are longer than 200 nucleotide noncoding RNAs without apparent functional coding capacity that function as regulators of cell growth and development. In recent years, increasing evidence implicates the involvement of Lnc RNAs in erythropoiesis. shlnc- EC6 is a Lnc RNA associated with erythroid differentiation but the mechanism remains undefined. In this study, we found that knockdown of shlnc- EC6 in purified mouse fetal liver erythroid progenitor and hematopoietic stem cells ( FLEPHSCs) significantly blocked erythroid enucleation. We also showed that Rac1 was negatively regulated by shlnc- EC6 at the posttranscriptional level via specific binding to sites within the 3′ UTR of Rac1 m RNA. Moreover, we found that knockdown of shlnc- EC6 led to upregulation of Rac1, followed by the activation of the downstream protein PIP5K, and subsequently resulted in the inhibition of enucleation in cultured mouse fetal erythroblasts. Thus, our findings suggest that shlnc- EC6 acts as a novel modulator to regulate mouse erythropoiesis via Rac1/ PIP5K signaling pathway. [ABSTRACT FROM AUTHOR]

ABSTRACT The WRF model is applied to simulate the low-level wind field for a wind farm located in a typical arid region in northwest China for February 2008. The selected region has complex terrain with sparse vegetation. Overall, the WRF model reproduced the variation features of wind speeds and wind directions. However, the model overestimated the observed low-level wind speeds, and there were large discrepancies for the low wind velocity (i.e. the errors of simulated winds increase with height and will be larger when the observed wind speeds are lower than 2.5 m/s). The features of the simulated errors and the possible causes in the model were analysed. The simulated low-level wind in the afternoon is more accurate than that in early morning, which is usually unstable. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In this article, the trends and variability of precipitation and precipitable water (PW) over the Qinghai-Xizang (Tibet) Plateau (QXP) (1970-2009) were analysed by using ERA-40 (The European Center for Medium-Range Weather Forecasts (ECMWF) 40 years Re-analysis) and NCEP (The National Centers for Environmental Prediction)/NCAR reanalyses data and the ground observed precipitation data from 60 sites. The results showed that the precipitation over the QXP had an overall increasing trend; however, a slight decreasing trend was observed over the southeast. This decreasing precipitation trend might be related to the South Asia monsoon degradation. Since 1970, a decreasing PW trend has occurred over the QXP in which the southeast is the most significant region. Because of the rising temperatures in the QXP, a remarkable PW conversion rate (PWCR) increase of 0.87% per decade has occurred over the past 40 years. Because of its steep terrain, the PWCR in the middle eastern region of the QXP increased faster than that of the other regions. The mean PWCR in the wet southern region of the QXP was higher than that of the dry northern region, which was higher in the winter than that in the summer. Although much precipitation occurred in the summer, in the wet regions, the PWCR was higher in the winter than in the summer. The PWCR peak in the wet and dry regions occurred during the precipitation-short and precipitation-sufficient seasons, respectively. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Soil freezing‐thawing cycle is a hallmark feature of the land surface over cold regions. Variations in soil moisture and temperature during frozen‐thawing (FT) process are important for water and energy exchange between land and atmosphere. Results of regional simulations by Community Land Model version 4.5 (CLM4.5) over the Tibetan Plateau show that error of daily soil temperature is within 3 °C and error of daily soil moisture is with 0.10 mm3/mm3 in FT process, averaged at 10 sites of whole Tibetan Plateau. Single‐point simulations show that model biases partly attribute to uncertainties of initial condition and soil category data; excluding impacts of model setting, large biases of soil moisture still exist during soil thawing, and CLM4.5 fails to simulate the diurnal cycle of soil moisture in this period. Modifications of the FT parameterizations in CLM4.5 are proposed, which include (1) use of virtual temperature (Tv) instead of constant freezing point to determine occurring of phase change, (2) introduction of phase change efficiency (ε) to optimize variation rate of soil temperature and moisture in FT process, and (3) consideration of inferred impacts of phase change on soil heat conduction. Single‐point and global simulations show that compared to original parameterizations in CLM4.5, these modifications can reproduce the features of daily and diurnal variations in soil moisture and make simulation in FT process closer to the observations. Key Points: Simulation errors are evident in FT process, and CLM4.5 fails to simulate daily and diurnal variation features of soil moistureUse of virtual temperature and phase change efficiency effectively improves daily and diurnal variations of soil moisture in FT processConsideration of the impact of phase change on soil heat conduction can reduce some soil temperature biases [ABSTRACT FROM AUTHOR]

A short‐lived (less than 2 days) inner Tibetan Plateau vortex (TPV) with heavy precipitation was simulated using the Weather Research and Forecasting model, and the sensitivity experiments with and without surface diabatic heating and atmospheric latent heating released by precipitation were conducted to investigate the roles of surface and atmospheric diabatic heating on the genesis and development of TPV. Results show that before the genesis of the TPV, there is an anomalous increase of surface heating flux; while a disturbance of potential vorticity (PV) at 500 hPa moves over this region, the PV is enhanced and induces the generation of TPV. The precipitation in turn reduces the surface heating flux. The release of condensation latent heating by precipitation during the development of TPV does not further contribute to its reinforcement. Instead, it is more likely a result of precipitation, tending to stabilize the atmosphere and conducive to the decay of TPV. The PV diagnoses further reveal that in the early phase, the strong diabatic heating in the lower levels associated with the increasing surface heating flux has a significantly positive contribution to the generation of the TPV. The precipitation results in the decrease of positive diabatic heating contribution at low levels. Inversely, the diabatic heating in the middle levels associated with the released latent heating of precipitation condensation tends to have the negative contribution to TPV, resulting in the decay of TPV. The study of this case can deepen our understanding on the mechanism of TPV and its precipitation. Key Points: The surface diabatic heating prior to the precipitation is crucial to the formation of TPVThe condensation latent heating caused by precipitation only seems to be a result of precipitation [ABSTRACT FROM AUTHOR]