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Purpose: Infertility remains a human health burden globally. Only a fraction of embryos produced via assisted reproductive technologies (ARTs) develop to the blastocyst stage in vitro. lncRNA abundance changes significantly during human early embryonic development, indicating vital regulatory roles of lncRNAs in this process. The aim of this study is to obtain insights into the transcriptional basis of developmental events. Methods: scRNA-seq data and SUPeR-seq data were used to investigate the lncRNA profiles of human preimplantation embryos. The top 50 highly expressed unique and shared lncRNAs in each stage of preimplantation development were identified. Comparative analysis of the two datasets was used to verify the consistent expression patterns of the lncRNAs. Differentially expressed lncRNAs were identified and subjected to functional enrichment analysis. Results: The lncRNA profiles of human preimplantation embryos in the E-MTAB-3929 dataset were similar to those in the GSE71318 dataset. The ratios of overlap among the top 50 highly expressed lncRNAs between two pairs of stages (2-cell stage vs. 4-cell stage and 8-cell stage vs. morula) were aberrantly low compared with those between other stages. Each stage of preimplantation development exhibited unique and shared lncRNAs among the top 50 highly expressed lncRNAs. Among the between-group comparisons, the 2-cell stage vs. 4-cell stage showed the highest number of differentially expressed lncRNAs. Functional enrichment analysis revealed that differentially expressed lncRNAs and their associated super enhancers and RNA binding proteins (RBPs) are closely involved in regulating embryonic development. These lncRNAs could function as important cell markers for distinguishing fetal germ cells. Conclusions: Our study paves the way for understanding the regulation of developmental events, which might be beneficial for improved reproductive outcomes. [ABSTRACT FROM AUTHOR]

The Unsupervised Domain Adaptation (UDA) methods aim to enhance feature transferability possibly at the expense of feature discriminability. Recently, contrastive representation learning has been applied to UDA as a promising approach. One way is to combine the mainstream domain adaptation method with contrastive self-supervised tasks. The other way uses contrastive learning to align class-conditional distributions according to the semantic structure information of source and target domains. Nevertheless, there are some limitations in two aspects. One is that optimal solutions for the contrastive self-supervised learning and the domain discrepancy minimization may not be consistent. The other is that contrastive learning uses pseudo label information of target domain to align class-conditional distributions, where the pseudo label information contains noise such that false positive and negative pairs would deteriorate the performance of contrastive learning. To address these issues, we propose Noise-robust cross-domain Contrastive Learning (NaCL) to directly realize the domain adaptation task via simultaneously learning the instance-wise discrimination and encoding semantic structures in intra- and inter-domain to the learned representation space. More specifically, we adopt topology-based selection on the target domain to detect and remove false positive and negative pairs in contrastive loss. Theoretically, we demonstrate that not only NaCL can be considered an example of Expectation Maximization (EM), but also accurate pseudo label information is beneficial for reducing the expected error on target domain. NaCL obtains superior results on three public benchmarks. Further, NaCL can also be applied to semi-supervised domain adaptation with only minor modifications, achieving advanced diagnostic performance on COVID-19 dataset. Code is available at https://github.com/jingzhengli/NaCL [ABSTRACT FROM AUTHOR]

Learning from multiple annotators aims to induce a high-quality classifier from training instances, where each of them is associated with a set of observed labels provided by multiple annotators under the impact of their varying abilities and own biases. When modeling the probability transition process from latent true labels to observed labels, most existing methods adopt class-level confusion matrices of annotators which assume that observed labels do not depend on the instance features and are just determined by the true labels. However, in practice the labeling process of annotators is impacted not only by the correlation between classes but also by the content of instances. Thus using only class-level confusion matrices to characterize the probability transition process may limit the performance that the classifier can achieve. In this work, we propose the noise transition matrix, that incorporates the impact of instance features on annotators' performance based on confusion matrices. Furthermore, we propose a simple and effective learning framework, which consists of a classifier module and a noise transition matrix module in a unified neural network architecture. Experimental results on synthetic and real datasets demonstrate the noise transition matrix is better than the confusion matrix for modeling multiple annotators and the superiority of our method in comparison with state-of-the-art methods. [ABSTRACT FROM AUTHOR]

This study aims to describe the epidemiological characteristics of scrub typhus, detect the spatio-temporal patterns of scrub typhus at county level, and explore the associations between the environmental variables and scrub typhus cases in Anhui Province. Time-series analysis, spatial autocorrelation analysis, and space–time scan statistics were used to explore the characteristics and spatiotemporal patterns of the scrub typhus in Anhui Province. Negative binomial regression analysis was used to explore the association between scrub typhus and environmental variables. A total of 16,568 clinically diagnosed and laboratory-confirmed cases were reported from 104 counties of 16 prefecture-level cities. The number of female cases was higher than male cases, with a proportion of 1.32:1. And the proportion of cases over 65 years old was the highest, accounting for 33.8% of the total cases. Two primary and five secondary high-risk clusters were detected in the northwestern, northeastern, and central-eastern parts of Anhui Province. The number of cases in primary and secondary high-risk clusters accounted for 60.27% and 3.00%, respectively. Scrub typhus incidence in Anhui Province was positively correlated with the population density, normalized difference vegetation index, and several meteorological variables. The mean monthly sunshine duration with 3 lags (SSD_lag3), mean monthly ground surface temperature with 1 lag (GST_lag1), and mean monthly relative humidity with 3 lags (RHU_lag3) had the most significant association with increased cases of scrub typhus. Our findings indicate that public health interventions need to be focused on the elderly farmers in north of the Huai River in Anhui Province. [ABSTRACT FROM AUTHOR]

The study aims to optimize the mix proportion of self-compacting concrete according to the workability and compressive strength. Firstly, based on computational fluid dynamics, the flowability and filling ability of self-compacting concrete were simulated by the single-fluid model to verify the single-fluid model. And then, the simulation of casting a pre-cambered composite beam was carried out. In the end, the mix proportion was optimized considering the filling ability and the compressive strength of self-compacting concrete. The results showed that increasing sand rate can improve the workability and decrease the rheological parameters of self-compacting concrete. The mixture with a 45% sand ratio in the case of 3% silica fume alone or 43% sand ratio in the case of 30% granulated blast furnace slag and 3% silica fume had adequate filling ability and excellent long term compressive strength. Moreover, the model can be used to simulate the filling ability and passing capacity of self-compacting concrete and the maximum error between the simulation results and the actual measured value is 4.80%. When the concrete mixture is considered to be uniform, namely, without considering the effect of the aggregates, the single-fluid model can simulate the casting of self-compacting concrete. [ABSTRACT FROM AUTHOR]

Symptom phenotypes have continuously been an important clinical entity for clinical diagnosis and management. However, non-specificity of symptom phenotypes for clinical diagnosis is one of the major challenges that need be addressed to advance symptom science and precision health. Network medicine has delivered a successful approach for understanding the underlying mechanisms of complex disease phenotypes, which will also be a useful tool for symptom science. Here, we extracted symptom co-occurrences from clinical textbooks to construct phenotype network of symptoms with clinical co-occurrence and incorporated high-quality symptom-gene associations and protein–protein interactions to explore the molecular network patterns of symptom phenotypes. Furthermore, we adopted established network diversity measure in network medicine to quantify both the phenotypic diversity (i.e., non-specificity) and molecular diversity of symptom phenotypes. The results showed that the clinical diversity of symptom phenotypes could partially be explained by their underlying molecular network diversity (PCC = 0.49, P-value = 2.14E-08). For example, non-specific symptoms, such as chill, vomiting, and amnesia, have both high phenotypic and molecular network diversities. Moreover, we further validated and confirmed the approach of symptom clusters to reduce the non-specificity of symptom phenotypes. Network diversity proposes a useful approach to evaluate the non-specificity of symptom phenotypes and would help elucidate the underlying molecular network mechanisms of symptom phenotypes and thus promotes the advance of symptom science for precision health. [ABSTRACT FROM AUTHOR]

Software systems are present all around us and playing their vital roles in our daily life. The correct functioning of these systems is of prime concern. In addition to classical testing techniques, formal techniques like model checking are used to reinforce the quality and reliability of software systems. However, obtaining of behavior model, which is essential for model-based techniques, of unknown software systems is a challenging task. To mitigate this problem, an emerging black-box analysis technique, called Model Learning, can be applied. It complements existing model-based testing and verification approaches by providing behavior models of blackbox systems fully automatically. This paper surveys the model learning technique, which recently has attracted much attention from researchers, especially from the domains of testing and verification. First, we review the background and foundations of model learning, which form the basis of subsequent sections. Second, we present some well-known model learning tools and provide their merits and shortcomings in the form of a comparison table. Third, we describe the successful applications of model learning in multidisciplinary fields, current challenges along with possible future works, and concluding remarks. [ABSTRACT FROM AUTHOR]

The rheometer was used to test the rheology of cement paste with and without nano-silica, and the fluidity and free water content were tested, the isothermal calorimetry of cement and C3S was tested and hydration products were monitored using Raman spectroscopy. A modified Bingham model was used to describe the rheological properties of the paste, and the effects of nano-silica with different particle sizes on rheological parameters including yield stress, plastic viscosity and thixotropy were derived. The results show that the fresh state properties of the cement paste vary with the particle size of nano-silica at the same dosage. The decrease in the particle size of nano-silica reduces the fluidity and free water content, but increases the yield stress and plastic viscosity. The flocculation and surface water absorption of nano-silica reduce the free water content at 5 minutes, which results in a decrease in flow diameter and an increase in yield stress. During the time evolution, the heat of hydration and Raman spectroscopy show that nano-silica with smaller particle size has higher nucleation and pozzolanic effect, that is, with the same dosage, nano-silica with small particle size provides more nucleation sites to form calcium silicate hydrate (C-S-H) seeds and to promote the hydration of C3S and the formation of C-S-H. [ABSTRACT FROM AUTHOR]

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The coupled carbonate weathering represents a significant carbon sink and can be controlled by the riverine hydrochemical variations. However, magnitudes, variations, and mechanisms responsible for the carbon sink produced by coupled carbonate weathering are unclear. In view of this, temperature, pH, dissolved oxygen, turbidity, electrical conductivity, and discharge of the Xijiang River at Wuzhou Hydrologic Gauging Station was recorded during October 2013 to September 2015 to elucidate the temporal variations in riverine hydrochemistry and their controlling mechanisms. To obtain the complete carbon sink flux (CSF) produced by coupled carbonate weathering with terrestrial aquatic photosynthesis in the river basin, the fluxes of dissolved inorganic carbon (DIC), autochthonous organic carbon (AOC, sourced from the transformation of DIC via aquatic photosynthesis), and sedimentary AOC were all considered. The results show that seasonal hydrochemical variations in the Xijiang River were related not only to dilution effects but also aquatic primary production. These results demonstrate that the variations in discharge caused by rainfall played a dominant role in controlling the variations in the CSF due to the chemostatic behavior of DIC and dissolved organic carbon (DOC). The CSF of the Xijiang River produced by coupled carbonate weathering was calculated as 11.06 t C km−2 a−1, including DIC carbon sink flux of 6.56 t C km−2 a−1, AOC flux (FAOC) of 2.25 t C km−2 a−1, and sedimentary AOC flux (FSAOC) of 2.25 t C km−2 a−1. The FAOC and FSAOC together accounted for approximately 69% of DIC carbon sink flux, or approximately 41% of the CSF, indicating that the riverine AOC flux may be high and must be considered in the estimation of rock weathering-related carbon sinks. [ABSTRACT FROM AUTHOR]

Crowdsourcing Software Development (CSD) has emerged as a new software development paradigm. Topcoder is now the largest competition-based CSD platform. Many organizations use Topcoder to outsource their software tasks to crowd developers in the form of open challenges. To facilitate timely completion of the crowdsourced tasks, it is important to find right developers who are more likely to win a challenge. Recently, many developer recommendation methods for CSD platforms have been proposed. However, these methods often make unrealistic assumptions about developer status or application scenarios. For example, they consider only skillful developers or only developers registered with the challenges. In this paper, we propose a meta-learning based policy model, which firstly filters out those developers who are unlikely to participate in or submit to a given challenge and then recommend the top k developers with the highest possibility of winning the challenge. We have collected Topcoder data between 2009 and 2018 to evaluate the proposed approach. The results show that our approach can successfully identify developers for posted challenges regardless of the current registration status of the developers. In particular, our approach works well in recommending new winners. The accuracy for top-5 recommendation ranges from 30.1% to 91.1%, which significantly outperforms the results achieved by the related work. [ABSTRACT FROM AUTHOR]

Biological carbon pumping (BCP) is a key process in which dissolved inorganic carbon in terrestrial aquatic ecosystems is utilized by aquatic autotrophs for photosynthesis and transformed into autochthonous organic matter (AOC). However, the mechanisms underlying BCP and the amount of generated AOC deposited effectively, are still poorly understood. Therefore, we conducted a systematic study combining modern hydrochemical monitoring and a sediment trap experiment in Fuxian Lake (Yunnan, SW China), the second-deepest plateau, oligotrophic freshwater lake in China. Temperature, pH, EC (electrical conductivity), DO (dissolved O2), [HCO3−], [Ca2+], SIc, partial CO2 (pCO2) pressure, and carbon isotopic compositions of HCO3− (δ13CDIC) in water from Fuxian Lake all displayed distinct seasonal and vertical variations. This was especially apparent in an inverse correlation between pCO2 and DO, indicating that variations of hydrochemistry in the lake water were mainly controlled by the metabolism of the aquatic phototrophs. Furthermore, the lowest C/N ratios and highest δ13Corg were recorded in the trap sediments. Analyses of the C/N ratio demonstrated that the proportions of AOC ranged from 30% to 100% of all OC, indicating that AOC was an important contributor to sedimentary organic matter (OC). It was calculated that the AOC flux in Fuxian Lake was 20.43 t C km−2 in 2017. Therefore, AOC produced by carbonate weathering and aquatic photosynthesis could potentially be a significant carbon sink and may have an important contribution to solving the lack of carbon sinks in the global carbon cycle. [ABSTRACT FROM AUTHOR]

Asian cold-based glacier yeasts with respect to their abundance, distribution, and taxonomy, in contrast to other continental cryosphere areas, have been little investigated. The present study reports the diversity and phylogeny of culturable cold-adapted yeasts in six cold habitats of the Glacier No.1 in the Tianshan Mountains (northwestern China). Of the total 591 yeast isolates, 401 were identified as basidiomycetous yeasts represented by 41 species of 15 genera, while 190 ascomycetous yeast isolates were assigned to the 8 species of 7 genera. The most prevalent species was Candida akabanensis with a 19.8% frequency of occurrence, followed by Vishniacozyma victoriae (16.4%) and Diutina rugosa (9.98%), of which V. victoriae was the only yeast species common to all six glacial habitats. Variability on the component and abundance of yeast taxa among glacial habitats primarily displayed in four dominant yeast genera, namely Candida, Vishniacozyma, Filobasidium, and Naganishia. However, network analysis illustrated that most of 32 rare yeast populations were habitat-specific, implying that the low-abundance yeast population was more easily influenced by the local habitat conditions (species sorting). Based on indicator species analyses, the subglacial habitat was characterized by psychrotolerant and/or psychrophilic yeast taxa. [ABSTRACT FROM AUTHOR]

Data items are usually replicated in modern distributed data stores to obtain high performance and availability. However, the availability-consistency and latencyconsistency trade-offs exist in data replication, thus system designers intend to choose weak consistency models, such as eventual consistency, which may result in stale reads. Since stale data items may lead to serious application semantic problems, we consider how to increase the probability of data recency which provides a uniform view on recent versions of data items for all clients. In this work, we propose HARP, a framework that can enhance data recency of eventually consistent distributed data stores in an efficient and highly available way. Through detecting possible stale reads under failures or not, HARP can perform reread operations to eliminate stale results only when needed based on our analysis on write/read processes. We also present solutions on how to deal with some practical anomalies in HARP, including delayed, reordered and dropped messages and clock drift, and show how to extend HARP to multiple datacenters. Finally we implement HARP based on Cassandra, and the experiments show that HARP can effectively eliminate stale reads, with a low overhead (less than 6.9%) compared with original eventually consistent Cassandra. [ABSTRACT FROM AUTHOR]

Nutrient retranslocation in trees is important in nutrient budgets and energy flows in forest ecosystems. We investigated nutrient retranslocation in the fine roots of a Manchurian Ash ( Fraxinus mandshurica) and a Larch ( Larix olgensis) plantation in northeastern China. Nutrient retranslocation in the fine roots was investigated using three methods, specifically, nutrient concentration, the ratio of Ca to other elements (Ca/other elements ratio) and nutrient content. The method based on nutrient content proved most suitable when investigating nutrient retranslocation from fine roots of the two species. The nutrient-content-based method showed that there were retranslocations of N, P, K and Mg from the fine roots of Manchurian Ash, with retranslocation efficiencies of 13, 25, 65, and 38 %, respectively, whereas there were no Ca retranslocations. There were retranslocations of N, P, K, Ca and Mg from the fine roots of Larch, with retranslocation efficiencies of 31, 40, 52, 23 and 25 %, respectively. [ABSTRACT FROM AUTHOR]

The abnormal pistils widely occur in Japanese apricot ( Prunus mume Sieb. et Zucc) and seriously affect the fruit production. In this study, a CCoAOMT homologue, PmCCoAOMT, was cloned in Japanese apricot and the bioinformatics software analyzed the structural characteristics. The PmCCoAOMT protein was detected to be located in the cell cytoplasm by onion transient expression experiment. Analysis of the real-time PCR data showed that PmCCoAOMT gene expressed in the prophase development of pistil and the expression level in 'Daqiandi' was higher than 'Longyan.' The expression level in 'Longyan' was higher than 'Daqiandi' in the late period development of pistil, and the expression level of perfect flower (perfect pistil) was higher than imperfect flower (pistil deformity and no pistil). Compared with the control, the over-expression of PmCCoAOMT transgenic tobacco lines showed bigger flowers, darker petals. The lignin monomer composition in transgenic tobacco lines was also measured, and the results showed that transgenic tobacco lines had a higher S (Syringyl)/G (Guaiacyl) ratio (22.3 %) than control lines (11.8 %). Also, the perfect flower buds contained more S/G ratio (92.62 %) than imperfect flower buds (83.55 %) in 'Daqiandi.' Our results indicated that the PmCCoAOMT gene might have function in lignin accumulation, which contributed to pistil development in Japanese apricot. [ABSTRACT FROM AUTHOR]

The rapid development of online services and information overload has inspired the fast development of recommender systems, among which collaborative filtering algorithms and model-based recommendation approaches are wildly exploited. For instance, matrix factorization (MF) demonstrated successful achievements and advantages in assisting internet users in finding interested information. These existing models focus on the prediction of the users' ratings on unknown items. The performance is usually evaluated by the metric root mean square error (RMSE). However, achieving good performance in terms of RMSE does not always guarantee a good ranking performance. Therefore, in this paper, we advocate to treat the recommendation as a ranking problem. Normalized discounted cumulative gain (NDCG) is chosen as the optimization target when evaluating the ranking accuracy. Specifically, we present three ranking-oriented recommender algorithms, NSMF, AdaMF and AdaNSMF. NSMF builds a NDCG approximated loss function for Matrix Factorization. AdaMF is based on an algorithm by adaptively combining component MF recommenders with boosting method. To combine the advantages of both algorithms, we propose AdaNSMF, which is a hybird of NSMF and AdaMF, and show the superiority in both ranking accuracy and model generalization. In addition, we compare our proposed approaches with the state-of-the-art recommendation algorithms. The comparison studies confirm the advantage of our proposed approaches. [ABSTRACT FROM AUTHOR]

Services composition technology provides a promising way to create new services in services-oriented architecture. However, some challenges are hindering the application of services composition. One of the major challenges encountered by composite services developer is how to effectively select a set of services across different autonomous regions (e.g., organization or business) to instantiate a composite service which can satisfy user's QoS constraints. To solve QoS-aware Web service composition problem, this paper proposes a global optimization selection (GOS) approach based on prediction mechanism for QoS values of local services. The GOS includes two parts. First, the local preprocessing service selection algorithm can be used to increase composite services performance in run-time by predicting the change of service quality parameters. Second, GOS aims at enhancing the run-time performance of global selection by reducing QoS aggregation operations. The simulation results show that the GOS has excellent selection and lower execution cost than existing approaches. [ABSTRACT FROM AUTHOR]

Field pull-out and laboratory tests were applied to investigate the effect of metal bolts and wire netting on plant root distribution and anchorage characteristics of 9-year-old Vitex negundo L. growing on a weakly weathered rocky slope (38°). Root number, length and diameter were recorded and single root specimens were classified and tested for tensile strength. The results show that root anchorage is different between the two constructions by bolts and wire. Under limited soil condition, root anchorage ability is 80% lower than when there is sufficient soil due to the reduction of the diameter and number of all second-order lateral roots, as well as the reduction of the tensile strength of the embedded second-order and first-order lateral roots on limited soil. We conclude that the distribution and anchorage of Vitex negundo L. is affected by limited soil availability on rocky slopes. [ABSTRACT FROM AUTHOR]

The Zoige wetland is the biggest alpine wetland in the world, and an important water resource of the Yellow River. Due to natural and human factors, the Zoige wetland has been seriously degraded. Existing studies on the Zoige wetland mainly focus on the macro features of the wetland, while the influence of the surrounding faults on the Zoige wetland degradation is rarely studied. This study uses terrain data to analyze the cover change and the water loss caused by the Wqie-Seji fault based on the distributed hydrological model. The simulated water loss demonstrates that the Normalized Difference Vegetation Index (NDVI) is the most important factor for inducing water loss. The fault is also a factor that cannot be neglected, which has caused 33% of the wetland water loss. Therefore, it is of importance to study the influence of the fault on the wetland degradation. [ABSTRACT FROM AUTHOR]

In addition to rainfall, high-resolution measurements of water level, pH, specific conductivity and temperature of Landiantang epikarst spring at Nongla, Mashan county in Guangxi Province, China were recorded in summer rainy season by using a data logger with time interval of fifteen minutes. Water from the spring issues along a karst conduit. During the rainstorms in summer, it was found that the pH and temperature of Landiantang spring increased while its specific conductivity decreased. As HCO3 −, Ca2+ and Mg2+ are the dominant ions, linear relationships between concentrations of those ions and specific conductivity were developed. According to the ion concentrations from the linear relationships, the saturation indexes of calcite (SIC), the saturation indexes of dolomite (SID) and CO2 partial pressure (Log $$ {\text{P}}_{{{\text{CO}}_{{\text{2}}} }} $$ ) of the spring were calculated. Results indicated that the Log $$ {\text{P}}_{{{\text{CO}}_{{\text{2}}} }} $$ of the spring during the rainstorms was lower than that without rain, and its SIC and SID was also lower. Combined with the characteristics of the epikarst zone, it was inferred that the above results were caused by the dilution of rainwater, because overland flow with high pH (due to neutralization of carbonate rock dusts in the air to rainwater) and low specific conductivity traveling through the conduit rapidly during rainstorms, showed greater influences on the hydrochemical variations of the epikarst spring. [ABSTRACT FROM AUTHOR]

Based on a proposed Web service-based grid architecture, a service grid middleware system called CROWN is designed in this paper. As the two kernel points of the middleware, the overlay-based distributed grid resource management mechanism is proposed, and the policy-based distributed access control mechanism with the capability of automatic negotiation of the access control policy and trust management and negotiation is also discussed in this paper. Experience of CROWN testbed deployment and application development shows that the middleware can support the typical scenarios such as computing-intensive applications, data-intensive applications and mass information processing applications. [ABSTRACT FROM AUTHOR]

A continuous high-resolution (monthly) record of stable isotopes (δ13C and δ18O) in a well-laminated freshwater travertine deposited at Baishuitai, SW China from May 1998 to November 2001 was presented. The travertine exhibits clear annual bands with coupled brown/white color laminations. Throughout field investigation, it was found that the thin (1.5–2.2 mm), brown porous lamina was formed in the monsoonal rainy season from April to September, whereas the thick (5–8 mm), dense white lamina was formed in the dry season from October to March. The comparisons of lamina thickness and stable isotope signals in the travertine with the meteorological records allow us to constrain the relevant geochemical processes in the travertine formation under different climate conditions and to relate climate variables to their physicochemical proxies in the travertine record. Sympathetic variations in lamina thickness, δ13C and δ18O along the sampled profile reflect changes in hydrogeochemistry, showing that thin lamina and low δ13C and δ18O values occur in warm and rainy seasons. The decreased amount of calcite precipitation and low δ13C values during the warm and rainy seasons is caused by dilution of overland flow after rainfall. The low δ18O values are believed to be related to the rainfall amount effect in subtropical monsoonal regions. This process is thought to be markedly subdued whenever the amount of rainfall is lower than a given threshold. Accordingly, distinct minima in lamina thickness, δ13C and δ18O are interpreted to reflect events with above-average rainfall, possibly heavy floods, and vice versa. This study demonstrates the potential of freshwater travertine to provide valuable information on seasonal or even monthly rainfall variations. [ABSTRACT FROM AUTHOR]

Absorbing water from soil by roots in vascular plants is an important physiological function and plays an essential role on their water balance. The root hydraulic conductance ( L P) determined by radical water transport inside the root is a major influence on the shoot water status, plant growth, and development. However, a few studies have focused on the effect of different substances on L P of roots, and the role of radical water transport was poorly understood. Based on the pressure-flux approach, this study used the roots of Fraxinus mandshurica seedlings with different treatments, i.e., distilled water, NH4NO3 solution, and HgCl2 to determine the effect of various substances on L P of roots. The objectives are: 1) to evaluate the difference in L P occurred between distilled water and NH4NO3 solution with various concentrations; and 2) to examine the changes of L P under distilled water and NH4NO3 solution with various concentrations after HgCl2 treatment. The results showed that L P of roots were 18.85×10−8 m/(s·MPa) in distilled water, 31.25–34.15×10−8 m/(s·MPa) in four NH4NO3 solutions (2, 4, 8 and 16 mmol/L), 14.69×10−8 m/(s·MPa) in distilled water after HgCl2-treated, and 9.63–13.57×10−8 m/(s·MPa) in four NH4NO3 solutions after HgCl2-treated, respectively. Aquaporins play an important role in regulating water uptake and transport in roots. NH4 + and NO3 − could stimulate activity of aquaporins, and L P of roots in NH4NO3 solution was distinctly 77% higher than in distilled water. Nevertheless, Hg2+ can inhibit activity of aquaporins, and and L P of roots decreased 22% in distilled water and 68% in NH4NO3 solution after treatment by HgCl2 respectively. These evidences suggested that both Hg2+-sensitive aquaporins and ion channels existing in the protoplasm and vacuole membranes could regulate root water uptake, transport, and integral plant water balance. [ABSTRACT FROM AUTHOR]

In our experiments, one-year-old Larix olgensis seedlings were cultivated in sand, and supplied with solutions with different concentrations of nitrate or phosphate. The effects of nitrogen and phosphorus supply on chlorophyll biosynthesis, total nitrogen content, and photosynthetic rate were studied. The experimental results are listed below: 1) 5-aminolevulinic acid (ALA) synthetic rate increased as nitrate concentrations supplied to larch seedlings increased from 1 to 8 mmol/L. But the rate decreased by 17% when nitrate concentration increased to 16 mmol/L, in contrast to the control. Under phosphate treatments, ALA synthetic rates were similar to those under nitrate treatments. The activities of porphobilinogen (PBG) synthase reached a maximum when larch seedlings were supplied with 8 mmol/L of nitrate or 1 mmol/L of phosphate. 2) when larch seedlings were supplied with 8 mmol/L of nitrate and 0.5 mmol/L of phosphate, the contents of chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids reached a maximum. The total nitrogen contents in leaves increased as nitrate concentrations increased. 3) When phosphate concentrations increased from 0.125 to 1 mmol/L, the total nitrogen contents in leaves slightly increased; however, continuous increase of phosphate concentrations resulted in the decrease in total nitrogen contents in leaves. When nitrate concentrations increased from 1 to 8 mmol/L, soluble protein contents in leaves increased in general, and continuous increase of nitrate concentrations induced a decrease in soluble protein contents in leaves. Under treatment of 0.25 mmol/L of phosphate, the soluble protein contents reached a maximum. 4) In general, Fv/ Fm increased as nitrate concentrations increased from 1 to 8 mmol/L, and continuous increase of nitrate concentration resulted in decrease in Fv/ Fm. The similar changes occurred under phosphate treatments. As nitrate concentrations increased from 1 to 8 mmol/L, photosynthetic rates gradually increased, but when nitrate concentrations increased to 16 mmol/L, photosynthetic rate reduced by 16%, in contrast to the control. Photosynthetic rates reached a maximum when seedlings were supplied with 1 mmol/L, and an oversupply of phosphate (2 mmol/L) resulted in decrease in photosynthetic rates. The results suggested that supply levels of nitrogen affected ALA biosynthetic rates, activities of PBG synthase, and affected contents of chlorophyll and carotenoids. Moreover, nitrogen supply levels affected contents of total nitrogen and soluble proteins in leaves, and net photosynthetic rates. ALA biosynthesis rates and activities of PBG synthase were affected by phosphate supply, but contents of chlorophyll and carotenoids were not affected. And net photosynthetic rates were affected little by phosphate supply. [ABSTRACT FROM AUTHOR]

Crowdsourcing has been a helpful mechanism to leverage human intelligence to acquire useful knowledge. However, when we aggregate the crowd knowledge based on the currently developed voting algorithms, it often results in common knowledge that may not be expected. In this paper, we consider the problem of collecting specific knowledge via crowdsourcing. With the help of using external knowledge base such as WordNet, we incorporate the semantic relations between the alternative answers into a probabilistic model to determine which answer is more specific. We formulate the probabilistic model considering both worker's ability and task's difficulty from the basic assumption, and solve it by the expectation-maximization (EM) algorithm. To increase algorithm compatibility, we also refine our method into semi-supervised one. Experimental results show that our approach is robust with hyper-parameters and achieves better improvement than majority voting and other algorithms when more specific answers are expected, especially for sparse data. [ABSTRACT FROM AUTHOR]