Species’ geographical range, environmental range and traits lead to specimen collection preference of dominant plant species of grasslands in Northern China

Many different factors,such as species traits,socio-economic factors,geographical and environmental factors,can lead to specimen collection preference.This study aims to determine whether grassland specimen collection in China is preferred by species traits(i.e.,plant height,flowering and fruiting period),environmental range(i.e.,the temperature and precipitation range)and geographical range(i.e.,distribution range and altitudinal range).Ordinary least squares models and phylogenetic generalized linear mixed models were used to analyze the relationships between specimen number and the explanatory variables.Random Forest models were then used to find the most parsimonious multivariate model.The results showed that interannual variation in specimen number between 1900 and 2020 was considerable.Specimen number of these species in southeast China was notably lower than that in northwest China.Environmental range and geographical range of species had significant positive correlations with specimen number.In addition,there were relatively weak but significant associations between specimen number and species trait(i.e.,plant height and flowering and fruiting period).Random Forest models indicated that distribution range was the most important variable,followed by flowering and fruiting period,and altitudinal range.These findings suggest that future floristic surveys should pay more attention to species with small geographical range,narrow environmental range,short plant height,and short flowering and fruiting period.The correction of specimen collection preference will also make the results of species distribution model,species evolution and other works based on specimen data more accurate.

Bird specimen number linked with species trait and climate niche breadth

Biological specimens are fundamental for taxonomy and flora/fauna research.More importantly,they also play crucial roles in recording environmental impacts on morphology and behavior,which is vital for biodiversity research and conservation.However,there are few systematic studies on the patterns and drivers of bird specimen number at regional scales.This study is the first attempt to examine the relationships between bird specimen number and species traits as well as climate niche breadth in China,aiming to answer two questions:1)how do species’temperature niche breadth and precipitation niche breadth influence specimen number?2)which trait is most associated with bird specimen number?The associations between bird specimen number and explanatory variables were examined using ordinary least squares,generalized linear models,phylogenetic generalized linear mixed models,and multiple comparisons.The results showed that Muscicapidae was the family with the highest specimen number,and Passeriformes was the order with the highest specimen number.Bird specimen number significantly increased with larger temperature niche breadth and precipitation niche breadth.Specimen number was also positively associated with geographic range size,habitat specificity,hunting vulnerability and clutch size,but negatively associated with body size.These findings suggest that future bird specimen collection should pay more attention to birds with limited ecological niches,large body sizes,and small clutch sizes.This research enhances the use of bird specimen data to study and preserve biodiversity.

Transcriptome and metabolomics analysis revealed that CmWRKY49 regulating CmPSY1 promotes β-carotene accumulation in orange fleshed oriental melon

The flesh color of oriental melons is an important commercial trait that affects consumer preferences.To explore the mechanisms underlying the flesh color formation and regulation during fruit ripening,carotenoid-targeted metabolomic and RNA-seq analysis were conducted between white-fleshed(WF) and orange-fleshed(OF) oriental melon cultivars at different stages.The carotenoid-targeted metabolomic analysis indicated that β-carotene was the major metabolite that caused differences in flesh color between the two cultivars.Additionally,through KEGG pathway enrichment and weighted gene co-expression network(WGCNA) analysis,metabolic pathways and related transcription factors that are associated with carotenoid metabolism were selected and transcriptome data was verified using RT-qPCR.Finally,the yeast one hybrid and luciferase activity showed that the transcription factor CmWRKY49 could directly bind to the CmPSY1 promoter to activate its expression in the ’OF’ cultivar.Transient overexpression of CmWRKY49 in ’OF’ cultivar increased the β-carotene content,while the β-carotene content decreased when it was silenced in the same cultivar.This study provides insights into the underlying regulatory network of carotenoid metabolism in oriental melon fruit.

Experimental Investigation on Shock Wave Characteristics of Aluminized Explosives in Air Blast

To investigate the shock wave characteristics of RDX-based aluminized explosives,air blast tests were conducted for measuring the parameters of 10 kg aluminized explosives which contained 0-40% aluminum.The results showed that with the increasing of aluminum content,the overpressures and impulses increase at first and then decrease within 7 m or 5 m,which reached the maximum when aluminum content was 20% or 30%.Power exponential formulas are used to fit the shock wave parameters vs scaled distance,where an equal weight of TNT is used to calculate the scaled distance.The overpressures of HL0 and TNT in tested locations not only conform to the similar law,but also conform to the same attenuation law after gaining the scaled distances of equal TNT mass.The pre-exponential factors of overpressure and impulse,kp and kI,decrease along with the increasing of Al content and keep the same pace as the calculated PCJ）.The attenuation coefficients a_P and aIincrease at first and decrease later with the increasing of aluminum content,and they reached the maximal values with30% Al containing,which keeps the same pace as the calculated QV.

A Generative Adversarial Networks for Log Anomaly Detection

Detecting anomaly logs is a great significance step for guarding system faults.Due to the uncertainty of abnormal log types,lack of real anomaly logs and accurately labeled log datasets.Existing technologies cannot be enough for detecting complex and various log point anomalies by using human-defined rules.We propose a log anomaly detection method based on Generative Adversarial Networks(GAN).This method uses the Encoder-Decoder framework based on Long Short-Term Memory(LSTM)network as the generator,takes the log keywords as the input of the encoder,and the decoder outputs the generated log template.The discriminator uses the Convolutional Neural Networks(CNN)to identify the difference between the generated log template and the real log template.The model parameters are optimized automatically by iteration.In the stage of anomaly detection,the probability of anomaly is calculated by the Euclidean distance.Experiments on real data show that this method can detect log point anomalies with an average precision of 95%.Besides,it outperforms other existing log-based anomaly detection methods.

Joint Design of Content Delivery and Recommendation in Wireless Caching Networks

Although content caching and recommendation are two complementary approaches to improve the user experience,it is still challenging to provide an integrated paradigm to fully explore their potential,due to the high complexity and complicated tradeoff relationship.To provide an efficient management framework,the joint design of content delivery and recommendation in wireless content caching networks is studied in this paper.First,a joint transmission scheme of content objects and recommendation lists is designed with edge caching,and an optimization problem is formulated to balance the utility and cost of content caching and recommendation,which is an mixed integer nonlinear programming problem.Second,a reinforcement learning based algorithm is proposed to implement real time management of content caching,recommendation and delivery,which can approach the optimal solution without iterations during each decision epoch.Finally,the simulation results are provided to evaluate the performance of our proposed scheme,which show that it can achieve lower cost than the existing content caching and recommendation schemes.

Morphological Characteristics and Nutrient Content of Fine Roots of 2-Year-Old and 3-Year-Old Eucalyptus grandis Plantation

[ Objective] This study aimed to explore the morphological characteristics and nutrient content of f＇me roots of 2-year-old and 3-year-old Euca/yptus grand/s plantation and investigate the correlation. [ Method] Fine roots of 2-year-old and 3-year-old Eucalyptus grandis plantation were collected as experimental materials, to determine the root diameter （D）, root length （L）, specific root length （SRL） and contents of major nutrient elements N, P, K, Ca, Mg and C of fine roots （level 1 -5）, study the morphological characteristics and major nutrient element content and investigate the correlation. [ Result] The results showed that morphological differences of fine roots （ level 1 - 5 ） of Eucalyptus grandis plantation were great with the increase of root order, to be specific, D and L increased and SRL decreased with the increasing root order; SRL, L and D of 3-year-old Eucalyptus grauclis plantation were greater than those of 2-year-old Euca/yptus grand/s plantation. Contents of N, Ca, Mg and C of fine roots of 2-year-old and 3-year-old Eucalyptus grandis plantation showed consistent orders with the increase of root order： N and Mg contents were reduced, while Ca and C contents were enhanced; P and K contents varied with different forest ages; both 2-year-old and 3-year- old Eucalyptus grandis showed an order of C 〉 K 〉 Ca （Mg） 〉 N. Major nutrient element content and morphological characteristics of Eucalyptus grand/s fine roots （level 1 -5 ） were extremely significantly correlated （P 〈0.01 ）, SRL, L and D could be adopted as reference indices to evaluate nutrient status of Eucalyptus grand/s. Required nutrients and fine root morphology of Eucalyptus grandis plantation changed with the increase of forest age, and the nutrient cycling and energy flow patterns also changed; major nutrient dements in fine roots of 2-year-old and 3-year-old Eucalyptus grandis plantation transferred in a different order from the growth order, therefore N fertilizer could be applied to improve the growth of fine roots. [ Condusion] This study laid the foundation for understanding the fine root morphology and nutrient variation pattern of Eucalyptus grandis plantation and enriching the response and adaptation mechanism theory of roots to environment, pos- sessing important reference significance for the sustainable development of Eucalyptus grand/s plantation.

Effects of Silicon on Physiology and Biochemistry of Dendrobium moniliforme Plantlets under Cold Stress

[ Objective] The study aimed to investigate the effects of silicon on physiology and biochemistry of Dendrobium moniliforme plantlets under low tempera- ture stress. [ Method ] By using Dendrobium monilforme as the experimental material, different concentrations of Na2SiO3 （0, O. 2, 0.4, 0.6, 0.8, 1.0, 5.0 and 10.0 mmol/L） was added to the basic medium[ 1/2MS ＋ 6-BA （0.1mg/L） ＋ NAA （ 1 mg/L） ＋ agar （7.2 g/L） ＋ sucrose （30 g/L） ] for tissue culture; af- ter hardening and transplanting, Dendrobium moniliforme plantlets were treated under low temperature stress at 4 ~C for 0, 24 and 48 h, in order to investigate the physiological response of Dendrobium ranniliforme leaves to different concentrations of Na2SiO3. [ Result] Under low temperature stress at 4℃, Dendrob/um mon//i- fortns leaves have certain osmotic regulation ability, and the three osmotic regulation substances show different variation trends at different stages. Appropriate con- centration of NshSiO3 can increase the contents of free proline, soluble sugar and soluble protein to varying degrees, reduce MDA content and further improve the cold resistance of Dendrobium moniliforme plantlets. The order of the effects of Na2SiO~ on various physiological indicators is ： free proline 〉 MDA 〉 soluble sugar （or soluble protein）. According to the correlation analysis among various physiological indicators, free proline, soluble sugar, soluble protein and MDA contents can all be used as reference indicators to identify the cold resistance of Dendrobium moniliforme. [ Conclusion] The addition of Na2SiO3 （0.4 retool/L） can moder- ately decrease the thermal energy for normal growth of Dendrobium moniliforme, which is conducive to reducing the cost of cultivation. Key words Na2SiO3 ;Dendrobium monlifforme;Low temperature stress;Physiological and biochemical characteristics

Effects of Silicon on the Growth of Cymbidium grandiflorium Plantlets from Tissue Culture

[ Objective] This study aimed to explore the effects of silicon on the growth of Cymbidium grandiflorium plantlets from silicon. [ Method] The test was carried out by adding different concentrations of Na~ SiO3 （0,1,2,3,4 and 5 mmol/L ） into the media of culturing Cymbidium grandiflorium plantlets. [ Result ] The results showed that silicon promoted the increase in plantlet height, root length, root number, leaf number and rooting percentage remarkably. And the promotion was affected by the concentration of Na2SiO3 with optimum concentration of 3 mmol/L. [ Conclusion] This study provides bases for improving the quality of C. grandifloorium plantlets from tissues culture and promoting their growth in late stage.