水稻体细胞无性系农艺性状播期响应指数的变异

系统研究了2个播期条件下24个水稻体细胞无性系及其1个供体亲本主要农艺性状播期响应指数（RITSD）的变异特点,主要结论如下：①株高、着粒密度、每穗实粒数、每穗着粒数及单株粒重5个性状的RITSD均值相对较大（大于1）,对播期反应较敏感,其性状值随播期推迟而增大;而播始天数、单株穗数、穗长、结实率及千粒重RITSD均值相对较小。②体细胞无性系各性状RITSD均发生了遗传变异,但不同性状间RITSD的变异频率及变异方向有较大差异：始播天数和株高的RITSD变异频率较高,而穗长的RITSD变异的机率较低;株高及千粒重的RITSD值变小,而单株穗数、穗长、着粒密度、每穗实粒数、每穗着粒数及结实率的RITSD值变大,播始天数和单株粒重RITSD的变异方向为双向变异。③供试的24个体细胞无性系中,有20个株系与供体亲本RITSD呈显著差异,RITSD的变异率达83.3%,但约75%的体细胞无性系仅1-2个性状的RITSD发生了显著变异。④聚类分析表明,体细胞无性系农艺性状RITSD存在不同的变异组合。

模拟降水变化下黄土丘陵区草地群落特征及其物候期响应

在全球气候变化背景下,黄土高原降水格局呈现出季节波动增强和极端降水事件增加趋势,降水格局变化势必会引起草地群落特征和物候期发生重要改变。为研究黄土丘陵区草地生态系统对降水改变的响应,选取黄土丘陵区退耕草地为研究对象,连续定位观测自然恢复小区不同降雨梯度下(0,±20%,±40%,±60%)物候动态变化,探究了物候期和群落结构对降水变化的响应状况。结果表明:(1)不同降水条件下群落物种组成及丰度存在明显差异,与对照组相比,增雨与减雨均提高了物种的种类。增雨60%群落种类最多,为18种。(2)降水梯度递增处理下,群落盖度呈先增加后降低趋势,地上生物量随呈单峰趋势。增雨20%处理和减雨20%处理均能够显著提高群落植被盖度和地上生物量,地上生物量在增雨处理下明显高于减雨处理。(3)丰富度和Shannon-Wiener指数总体上都呈增加趋势,减雨20%,40%,60%均使Pielou均匀度指数降低。(4)不同降水条件对物种物候期的影响显著(p<0.05),群落返青期、繁殖期和和枯黄期在减雨处理下显著提前,而增雨处理则使其繁殖期和枯黄期发生推迟。综上,群落物种组成、植被盖度和地上生物量在不同降水处理下表现出显著差异,而物种多样性对降水变化响应不敏感。

缶汾气候变化对蚱蝉始鸣期的影响初探

利用临汾市气象局观测站1981年-2010年的蚱蝉物候期观测资料和同期气象资料，采用统计和一元回归方法，分析了蚱蝉物候期变化及其对气候变化的响应情况。结果表明，在气候变暖的背景下，30年间临汾气温、地温均呈上升趋势，同时期内蚱蝉始鸣期呈提早趋势，蚱蝉的始鸣期与降水相关性不显著。蚱蝉始鸣期的变化规律与气候变化的趋势相对应，说明动物物候期对气候变暖能够作出一定的响应。

探究民宿的亲子主题在线评论有用性影响因素

在线评论可以帮助消费者了解商品的信息,但随着评论信息数量的增加,会导致信息过载,从而降低评论的有用性。本研究以“携程”网站上的13,840条在线评论为基础,采用负二项回归模型,探讨影响亲子主题的民宿(B&Bs)在线评论有用性驱动因素和机制。结果表明:评论照片、评论内容长度、文本情感以及历史评论数量对评论的有用性具有显著的正向影响。此外,从多情感角度分析,无论评论情感为积极、消极还是中立,响应期时间间隔越长,评论的有用性就越低。本文通过亲子主题的民宿在线评论,探讨了评论的有用性影响因素,拓展了在线评论的研究。根据研究结果,提出了针对性的建议措施,这些建议对于促进民宿的经济发展具有一定的参考价值。

RITSD Analysis of the Agronomic Traits of Somaclonal in Rice

[Objective]The aim was to study the sensitive response characteristics of the main agronomic traits of somaclonal and the variation of sensitive response of the lines of somaclonal to sowing date. [Method]The RITSD changing of agronomic traits was studied by using 24 rice somaclonal and its donor parent under two sowing dates. [Result]The average values of RITSD were higher （over one） for the traits of pant height （PH）,density of spikelets （DS）,filled spikelets per panicle （FSP）,spikelets per panicle （SP） and grain weight per plant （GWP）,but lower for days of sowing to heading （DSH）,effective panicles （EP）,panicle length （PL）,seed setting rate （SS） and 1 000-grain weight （1 000-GW）. These showed that PH,DS,FSP,SP and GWP were easily affected by sowing date and tended to higher with the later sowing; the RITSD of somaclonal changed with the agronomic traits. The frequency of RITSD＇ variation of DSH and PH was higher than that of PL. The RITSD＇ value of EP,PL,DS,FSP,SP and SS became higher,and higher or lower for DSH and GWP in different somaclonal; compared with the donor,20 of 24 was significantly different,and the frequency of RITSD variation was over 83. 3%,however,RITSD of the most lines （75%） changed only for 1-2 characters; cluster analysis showed that the RITSD of agronomic traits belonged to different combinations of somaclonal in rice. [Conclusion]the study had provided a theoretical basis for the screening and using of the somaclonal.

Response of Invasive Plant Alligatorweed to Salt Stress at Early Growth Stage

[Objective] The study aimed to investigate the early growth stage＇s response of invasive plant alligatorweed（Alternanthera philoxeroides） under salt stress.[Method] The alligatorweed was cultivated with four different NaCl concentrations 0（control）, 100, 200, 300 mmol/L diluted in 1/2 Hoagland＇s solution at early stage.During the period, we measured the number of nodes and leaves, length, fresh weight, dry weight and water content of stems to determine the effect of salt on alligatorweed growth. [Result] Compared with control, the node number, leaf number,length, fresh weight and dry weight of the stems significantly changed in NaCl solution, and the difference was positively related to NaCl concentration. We concluded that middle and high concentrations of NaCl significantly inhibited the growth of alligatorweed, by suppressing the node number, leaf number, length, fresh weight and dry weight of the stems. Among them, the stem length and fresh weight were more sensitive to NaCl stress. [Conclusion] The present result is helpful to understand the alligatorweed＇s adaptability to saline environment, and also helpful to prevent its invasion in such environment.

Potentially probiotic bacteria induce efficient maturation but differential cytokine production in human monocyte-derived dendritic cells

AIM： To analyze the ability of nine different potentially probiotic bacteria to induce maturation and cytokine production in human monocyte-derived dendritic cells （moDCs）. METHODS： Cytokine production and maturation of moDCs in response to bacterial stimulation was analyzed with enzyme-linked immunosorbent assay （ELISA） and flow cytometric analysis （FACS）, respectively. The kinetics of mRNA expression of cytokine genes was determined by Northern blotting. The involvement of different signaling pathways in cytokine gene expression was studied using specific pharmacological signaling inhibitors. RESULTS： All studied bacteria induced the maturation of moDCs in a dose-dependent manner. More detailed analysis with S. thermophilus THS, B. breve Bb99, and L. lactis subsp, cremoris ARH74 indicated that these bacteria induced the expression of moDC maturation markers HLA class Ⅱ and CD86 as efficiently as pathogenic bacteria. However, these bacteria differed in their ability to induce moDC cytokine gene expression. S. thermophilus induced the expression of pro-inflammatory （TNF-α, IL-12, IL-6, and CCL20） and Thl type （IL-12 and IFN-γ） cytokines, while B. breve and L. lactis were also potent inducers of antiinflammatory IL-10. Mitogen-activated protein kinase （MAPK） p38, phosphatidylinositol 3 （PI3） kinase, and nuclear factor-kappa B （NF-κB） signaling pathways were shown to be involved in bacteria-induced cytokine production. CONCLUSION： Our results indicate that potentially probiotic bacteria are able to induce moDC maturation, but their ability to induce cytokine gene expression varies significantly from one bacterial strain to another,

Second-line therapy for gemcitabine-pretreated advanced or metastatic pancreatic cancer

AIM： To investigate second-line chemotherapy in gemcitabine-pretreated patients with advanced or metastat- ic pancreatic cancer [（frequency, response, outcome, course of carbohydrate antigen 19-9 （CA 19-9）].METHODS： This retrospective study included all patients with advanced or metastatic pancreatic cancer （adenocarcinoma or carcinoma） treated with secondline chemotherapy in our center between 2000 and 2008. All patients received first-line chemotherapy with gemcitabine, and prior surgery or radiotherapy was permitted. We analyzed each chemotherapy protocol for second-line treatment, the number of cycles and the type of combination used. The primary endpoint was overall survival. Secondary endpoints included progression-free survival, response rate, grade 3-4 toxicity, dosage modifications and CA 19-9 course.a second-line therapy among 206 patients who had initially received first-line treatment with a gemcitabi- ne-based regimen. Median number of cycles was 4 （range： 1-12） and the median duration of treatment was 2.6 mo （range： 0.3-7.4）. The overall disease control rate was 40.0%. The median overall survival and progression-free survival from the start of second-line therapy were 5.8 （95% CI： 4.1-6.6） and 3.4 mo （95% CI： 2.4-4.2）, respectively. Toxicity was generally acceptable. Median overall survival of patients with a CA 19-9 level declining by more than 20% was 10.3 mo （95% CI： 4.5-11.6） vs 5.2 mo （95% CI： 4.0-6.4） for others （P = 0.008）.CONCLUSION： A large proportion of patients could benefit from second-line therapy, and CA 19-9 allows efficient treatment monitoring both in first and secondline chemotherapy.

The Short-term Effects of Temperature and Free Ammonia on Ammonium Oxidization in Granular and Floccular Nitrifying System

The short-term effects of temperature and free ammonia (FA) on ammonium oxidization were investigated in this study by operating several batch tests with two different partial nitrification aggregates, formed as either granules or flocs. The results showed that the rate of ammonium oxidation in both cultures increased significantly as temperature increased from 10 to 30 °C. The specific ammonium oxidation rate with the granules was 2-3 times higher than that with flocs at the same temperature. Nitrification at various FA concentrations and temperatures combination exhibited obvious inhibition in ammonium oxidation rate when FA was 90 mg·L 1 and tempera- ture dropped to 10 °C in the two systems. However, the increase in substrate oxidation rate of ammonia at 30 °C was observed. The results suggested that higher reaction temperature was helpful to reduce the toxicity of FA. Granules appeared to be more tolerant to FA attributed to the much fraction of ammonia oxidizing bacteria (AOB) and higher resistance to the transfer of ammonia into the bacterial aggregates, whereas in the floc system, the bacteria distributed throughout the entire aggregate. These results may contribute to the applicability of the nitrifying granules in wastewater treatment operated at high ammonium concentration.

Sedimentary response to volcanic activity in the Okinawa Trough since the last deglaciation

To investigate the relationship between volcanic activity and sediment record on regional and temporal scales,158 surface sediment samples were collected from the East China Sea Shelf to the northern Okinawa Trough (OT),and two cores recovered in the northern and southern OT,respectively.Mineralogy,grain-size,and geochemical analyses of those samples show that:1) volcanic glass,volcanic-type pyroxene,hypersthenes,and magnetite increase in sediment influenced by volcanic activity;2) sediment grain sizes (and also silt content) increase in ash layers;and 3) the contents of Na2O and Zr are higher,while terrigenous elements,e.g.,TFe2O3 and K2O,and biogenous compositions,e.g.,CaO and Sr,are relatively lower in ash layers than those of non-ash layers.The distribution of volcanic ash has three distinguishing characteristics:1) volcanic ash is more abundant in the northern and central OT than the southern OT;2) volcanic ash increases from continental shelf to the trough;3) the sediment during the last 12 000 a suggests stronger volcanic events than during 15 000-12 000 a.The eruptive locations,frequency,and volume of calderas are among the most important factors controlling the distributions of volcanic ash.In addition,the main Kuroshio warm current that extends northward probably impeded the diffusion of volcanic ash to the west and south in the OT.However,a southward current probably carried some volcanic ash toward southern OT.

Preliminary Analysis of the Relationship between the Magnitude Deviation of the Station and Site Response in the Fujian Digital Seismic Network

Using the records of 3,069 regional earthquake events from the Fujian Digital Seismic Network from October 2008 to December 2015,in which the magnitude of each of the events was measured by at least six stations,statistics are taken on the deviation between the magnitude of a single station and the average magnitude of the network. It is found that the magnitudes average deviation of each station is-0. 31-0. 68. Statistics are also taken for the period corresponding to the maximum amplitude of the record measured in each station for calculating the magnitude,and the dominant period gained is 0. 06s-0. 38s; site response of each seismic station is inverted using the Moya method,and it is found that the site response of 98 stations is in the bands of 1-20 Hz,suggesting that the site has an amplifying or suppressing effect on the signals in certain frequency bands;Considering the site response corresponding to the inherent 0. 8s period of the WoodAnderson pendulum seismograph,and comparing the magnitude deviation caused by the site response corresponding to the dominant period time of each station with the average magnitude deviation, we obtain that there is a good linear relationship between the magnitude deviation from the dominant period site response and the average deviation of the magnitude of each station,indicating that the magnitude deviation of a single station has a close relationship with the site response of the period corresponding to the maximum amplitude measured for calculating the magnitude.

Response Spectrum Method for Extreme Wave Loading With Higher Order Components of Drag Force

Response spectra of fixed offshore structures impacted by extreme waves are investigated based on the higher order components of the nonlinear drag force. In this way, steel jacket platforms are simplified as a mass attached to a light cantilever cylinder and their corresponding deformation response spectra are estimated by utilizing a generalized single degree of freedom system. Based on the wave data recorded in the Persian Gulf region, extreme wave loading conditions corresponding to different return periods are exerted on the offshore structures. Accordingly, the effect of the higher order components of the drag force is considered and compared to the linearized state for different sea surface levels. When the fundamental period of the offshore structure is about one third of the main period of wave loading, the results indicate the linearized drag term is not capable of achieving a reliable deformation response spectrum.

Dynamic response characteristics of super high-rise buildings subjected to long-period ground motions

Spectrum characteristics of different types of seismic waves and dynamic response characteristics of super high-rise building structures under long-period ground motions were comparatively analyzed. First, the ground response wave （named LS-R wave） of a soft soil site with deep deposit, taking long-period bedrock seismic record as input, was calculated by wave propagation method. After that, a TOMAKOMAI station long-period seismic record from the Tokachi-Oki earthquake and conventional E1-Centro wave were also chosen. Spectrum characteristics of these waves were analyzed and compared. Then, a series of shaking table tests were performed on a 1：50 scale super high-rise structural model under these seismic waves. Furthermore, numerical simulation of the prototype structure under these excitations was conducted, and structure damages under different intensive ground motions were discussed. The results show that： 1） Spectrum characteristics of ground response wave are significantly influenced by soft soil site with deep deposit, and the predominant period has an increasing trend. 2） The maximum acceleration amplification factor of the structure under the TOM wave is two times that under the E1-Centro wave; while the maximum displacement response of the structure under the TOM wave is 4.4 times that under the E1-Centro wave. Long-period ground motions show greater influences on displacement responses than acceleration responses for super high-rise building structures. 3） Most inelastic damage occurs at the upper 1/3 part of the super high-rise building when subjected to long-period ground motions.

Optimization of electrical discharge machining process parameters for Al6061/cenosphere composite using grey-based hybrid approach

Fly ash has congregated considerable attention as a potential reinforcement for aluminum matrix composites(AMCs)to enhance selective properties and reduce the cost of fabrication.However,poor machinability of such AMCs limits their application.The present study focuses on the preparation of cenosphere fly ash reinforced Al6061alloys by compo casting method.X-ray diffraction analysis of the prepared AMCs exposes the presence of cenosphere particles without any formation of other intermetallic compounds.In this study,electrical discharge machining(EDM)was engaged to examine the machinability of the prepared metal matrix composite(MMCs).The measured performance characteristics for the various combinations of input process parameters were considered to be MRR,EWR and SR.Face centered central composite design(CCD)of response surface method(RSM)was employed to design the number of experimental trials required and a hybrid approach of grey-based response surface methodology(GRSM)was imposed for predicting the optimal combination of processing parameter in EDM process.Generous improvement was observed in the performance characteristics obtained by employing both the optimal setting of machining parameters.The optical3D surface profile graphs of the ED machined surface also revealed the improvement in surface quality and texture employing the optimal processing conditions proposed by hybrid GRSM approach.

Comparison of two different kinds of regimens in treatment of advanced non-small cell lung cancer

Objective： The aim of this study was to analyze and compare the recent efficacy and toxicity of a three-drug platinum-based regimen （A regimen）： [cisplatin （DDP） ＋ gemcitabine （GEM） ＋ vinorelbine （NVB）] and a two-drug combination without a platinum drug （B regimen）： GEM ＋ NVB, which were used to treat 55 advanced non-small cell lung cancer （NSCLC） patients, in a bid to provide a guidance for clinical treatment. Methods： Twenty-four cases of advanced NSCLC （stage Ill-IV） patients were treated with A regimen （DDP 35 mg/m^2 d1-3; GEM 1250 mg/m^2 d1, 8 ）. The other 31 cases were treated with B （GEM 1250 mg/m^2 d1,8; NVB 25 mg/m^2 d1, 8 ）. Repeat every 3 weeks for 6 courses. Results： In A regimen group, the overall response rate was 45.8% （CR ＋ PR = 11）, median response time was 5.5 months, median survival time was 11 months and 1-year survival rate was 41.7%. In B regimen group, the overall response rate was 48.4% （CR ＋ PR = 15） and median response time, survival time and 1-year survival rate were respectively 6.5 and 10 months and 41.9%. The major toxicities were nausea/vomiting, myelosuppression in A regimen group, myelosuppression and phlebitis in B regimen group, respectively. Conclusion： A regimen and B regimen for advanced NSCLC have similar response rate （P 〉 0.05）. B regimen, a two-drug combination without a platinum drug is of less toxicity and more safety than A regimen, a three-drug platinum-based regimen and is recommended to be a regimen in the first-line treatment for advanced NSCLC.

Single-Ga Sb-nanowire-based room temperature photodetectors with broad spectral response

Single-gallium antimonide （GaSb）-nanowire- based photodetectors were fabricated on both rigid SiO2/Si substrate and flexible polyethylene terephthalate （PET） substrates, both of which exhibited high responsivity, fast- response, and long-term stability in photoswitching over a broad spectral range from ultraviolet to near infrared. Besides, the as-fabricated rigid device exhibited high responsivity of 7,350 A/W under illumination of 2 = 350 nm and light intensity P = 0.2 mW/cm^2, while the flexible device displays higher detectivity of 9.67 × 10^9 jones at 700 nm than the rigid one and lower noise equivalent power （NEP, NEP＊700 nm = 2.0 × 10^-12 W/Hz^1/2） for the much lower dark current on PET. The high responsivity, broad spectral detection from ultraviolet to near-infrared and long-term stability make GaSb nanowire one of the most important candidates to construct advanced optical sensors or other optoelectronic devices.

Facile preparation of self-assembled MXene@Au@CdS nanocomposite with enhanced photocatalytic hydrogen production activity

Photocatalytic hydrogen production is considered a promising approach to generating clean sustainable energy.However,the conventional co-catalyst(e.g.,Pt)used in photocatalytic hydrogen production is high-cost and difficult to obtain.Here,we designed and prepared a ternary nanocomposite MXene@Au@Cd S,which can be used in the field of efficient and excellent photocatalytic hydrogen production.The MXene@Au@Cd S has a hydrogen production rate of 17,070.43μmol g^-1h^-1(tested for 2 h),which is 1.85 times that of pure Cd S nanomaterials.The improved hydrogen production performance of the MXene@Au@Cd S is attributed to:(i)MXene provides more active adsorption sites and reaction centers for Au and Cd S nanoparticles;(ii)the synergistic effect of Au’s strong surface plasmon resonance expands the optical response range of Cd S.Therefore,this work solves the problem of the solid connection between the surface functional groups of photocatalyst,and achieves rapid interface charge transfer and long-term stability during the hydrogen production.

Numerical simulation study of temperature change over East China in the past millennium

Despite many studies on reconstructing the climate changes over the last millennium in China,the cause of the China's climate change remains unclear.We used the UVic Earth System Climate Model(UVic Model),an Earth system model of intermediate complexity,to investigate the contributions of climate forcings(e.g.solar insolation variability,anomalous volcanic aerosols,greenhouse gas,solar orbital change,land cover changes,and anthropogenic sulfate aerosols) to surface air temperature over East China in the past millennium.The simulation of the UVic Model could reproduce the three main characteristic periods(e.g.the Medieval Warm Period(MWP),the Little Ice Age(LIA),and the 20th Century Warming Period(20CWP)) of the northern hemisphere and East China,which were consistent with the corresponding reconstructed air temperatures at century scales.The simulation result reflected that the air temperature anomalies of East China were larger than those of the global air temperature during the MWP and the first half of 20CWP and were lower than those during the LIA.The surface air temperature of East China over the past millennium has been divided into three periods in the MWP,four in the LIA,and one in the 20CWP.The MWP of East China was caused primarily by solar insolation and secondarily by volcanic aerosols.The variation of the LIA was dominated by the individual sizes of the contribution of solar insolation variability,greenhouse gas,and volcano aerosols.Greenhouse gas and volcano aerosols were the main forcings of the third and fourth periods of the LIA,respectively.We examined the nonlinear responses among the natural and anthropogenic forcings in terms of surface air temperature over East China.The nonlinear responses between the solar orbit change and anomalous volcano aerosols and those between the greenhouse gases and land cover change(or anthropogenic sulfate aerosols) all contributed approximately 0.2℃ by the end of 20th century.However,the output of the energy-moisture balance atmospheric model from UVic showed no obvious nonlinear responses between anthropogenic and natural forcings.The nonlinear responses among all the climate forcings(both anthropogenic and natural forcings) contributed to a temperature increase of approximately 0.27℃ at the end of the 20th century,accounting for approximately half of the warming during this period;the remainder was due to the climate forcings themselves.

Phase-response synchronization in neuronal population

In this study,we have formulated the phase description of the neuronal oscillator with non-instantaneous synaptic inputs and external periodic stimulus by using the phase sensitivity function.By numerical simulation,we have found that the phase of a neuronal oscillator undergoes periodic evolution or locked state,which is determined by the synaptic time constant.The synaptic time constant is also an important condition under which the global network is synchronized.When the synaptic time constant is relatively small,perfectly synchronized behavior quickly occurs in the neuronal population.As the synaptic time constant becomes slightly larger,periodic synchronization emerges in the neuronal population.However,synchronized activity in the neuronal population is lost for larger synaptic time constant.The external periodic stimulus can change the synchronization patterns in the neuronal population.With a weak low-frequency stimulus,the neuronal populations quick synchronized bursting;whereas a high-frequency stimulus can produce synchronized overlapping bursting.We have also found that neuronal oscillators with type-II phase response curves are more susceptible to synchronization than those with type-I phase response curves.