mlsa-iai-msu-lab/ru_sci_bench_zho_cite_reranking huggingface dataset:
Mutation in the gene encoding 1-aminocyclopropane-1-carboxylate synthase 4 (CitACS4) led to andromonoecy in watermelon

Although it has been reported previously that ethylene plays a critical role in sex determination in cucurbit species, how the andromonoecy that carries both the male and hermaphroditic flowers is determined in watermelon is still unknown. Here we showed that the watermelon gene 1-aminocyclopropane-1-carboxylate synthase 4 (CitACS4), expressed specifically in carpel primordia, determines the andromonoecy in watermelon. Among four single nucleotide polymorphism (SNPs) and one InDel identified in the coding region of CitACS4, the C364W mutation located in the conserved box 6 was cosegregated with andromonoecy. Enzymatic analyses showed that the C364W mutation caused a reduced activity in CitACS4. We believe that the reduced CitACS4 activity may hamper the programmed cell death in stamen primordia, leading to the formation of hermaphroditic flowers.
探析妊娠滋养细胞疾病中VE-cadherin的表达及其临床意义

目的探析妊娠滋养细胞疾病中血管内皮钙黏蛋白的表达及其临床意义。方法选取2010年12月至2015年4月在新疆医科大学第一附属医院就诊的50例妊娠滋养细胞疾病患者和20例行人工流产手术的正常早孕者作为本次研究的对象。其中,将妊娠滋养细胞疾病患者按照疾病类型分为A组、B组、C组以及D组,将正常早孕者作为本次研究的E组。结果E组与A组的差异无统计学意义(P > 0.05)。E组VE-cadherin mRNA的表达量均明显高于B组、C组以及D组,A组VE-cadherin mRNA的表达量均明显高于B组、C组以及D组,B组VE-cadherin mRNA的表达量均明显高于C组和D组, C组VE-cadherin mRNA的表达量明显高于D组;且差异均具有统计学意义(P < 0.05)。结论VE-cadherin mRNA的表达量与葡萄胎有着非常密切的关系,其下调与葡萄胎的恶变有着直接的关系;由此可知VE-cadherin mRNA的表达可成为检测妊娠滋养细胞疾病的参考指标,有着重大的临床意义。
Seismic damage analysis of the outlet piers of arch dams using the finite element sub-model method

This study aims to analyze seismic damage of reinforced outlet piers of arch dams by the nonlinear finite element (FE) sub-model method. First, the dam–foundation system is modeled and analyzed, in which the effects of infinite foundation, contraction joints, and nonlinear concrete are taken into account. The detailed structures of the outlet pier are then simulated with a refined FE model in the sub-model analysis. In this way the damage mechanism of the plain (unreinforced) outlet pier is analyzed, and the effects of two reinforcement measures (i.e., post-tensioned anchor cables and reinforcing bar) on the dynamic damage to the outlet pier are investigated comprehensively. Results show that the plain pier is damaged severely by strong earthquakes while implementation of post-tensioned anchor cables strengthens the pier effectively. In addition, radiation damping strongly alleviates seismic damage to the piers.
Seismic performance of buildings during 2011 Van earthquakes and rebuilding efforts

The October 23, 2011 M7.2 Tabanli - Van and November 9, 2011 M5.2 Edremit – Van earthquakes caused damage in a widespread area across the Van province in Turkey. The ground motions, the damage caused by these earthquakes and the recent progress related to recovery efforts are presented herein. First, the key properties of the recorded strong ground motions like spectral amplitudes and directionality are evaluated. The observed damage in the affected reinforced concrete and masonry structures are discussed. The set of common structural damage mechanisms (i.e., soft story failure, torsional response due to plan irregularity, short column failure, pull out failure, pounding) observed in the damaged buildings were identified. The relationship between the key structural properties and the extent of damage is investigated. The primary loss drivers across the region were identified to be the poor quality of workmanship and improper use of building materials. The results from the investigation suggest that a large portion of the loss could have been prevented if sufficient attention and care were given to the implementation of the design regulations and in particular to the construction practice. Lastly, the recent progress in the ongoing rebuilding activities is presented.
组织定居巨噬细胞起源及稳态维持和功能研究进展

组织定居巨噬细胞广泛存在于各种组织器官中,具有高度的异质性。组织定居巨噬细胞参与胚胎及个体的生长发育,并介导炎症反应和组织损伤修复,在维持组织稳态中具有十分重要的作用。近年来借助体内遗传示踪技术,组织定居细胞的来源,维持稳态机制以及组织定居巨噬细胞与疾病关系的研究均有了突破性进展,本文拟从组织定居巨噬细胞的起源,稳态维持及其生理病理功能等最新研究进展进行综述,以丰富我们对组织定居巨噬细胞维持机体稳态机制的理解,并探索以组织定居巨噬细胞为靶点治疗相关疾病的新策略。
Synthesis and characterization of poppy seed oil methyl esters

Response surface methodology (RSM) was used to determine the optimum conditions of the methanolysis of crude poppy seed oil using NaOCH_3 as catalyst. The experiments were run according to five levels, four variable central composite rotatable design (CCRD) using RSM. The reaction variables, i.e., molar ratio of methanol/oil (3:1–9:1), catalyst concentration (0.5 wt%–1.25 wt% NaOCH_3), reaction temperature (25–65 °C), and reaction time (20–90 min) were studied. We demonstrated that the molar ratio of methanol/oil, catalyst concentration, and reaction temperature were the significant parameters affecting the yield of poppy seed oil methyl esters (PSOMEs). The optimum transesterification reaction conditions, established using the RSM, which offered a 89.35% PSOME yield, were found to be 7.5:1 molar ratio of methanol/oil, 0.75% catalyst concentration, 45 °C reaction temperature, and 90 min reaction time. The proposed process provided an average biodiesel yield of more than 85%. A linear correlation was constructed between the observed and predicted values of the yield. The gas chromatography (GC) analyses have shown that PSOMEs contain linoleic-, oleic-, palmitic-, and stearic-acids asmain fatty acids. The FTIR spectrum of the PSOMEs was also analyzed to confirm the completion of the transesterification reaction. The fuel properties of the PSOMEs were discussed in light of biodiesel standards (ASTM D 6751 and EN 14214).
Modeling and simulation of urea-water-solution droplet evaporation and thermolysis processes for SCR systems

A reliablemathematicalmodel of urea-water-solution (UWS) droplet evaporation and thermolysis is developed. The well known Abramzon–Sirignano evaporation model is corrected by introducing an adjustment coefficient considering the different evaporation behaviors of UWS droplet at different ambient temperatures. A semidetailed kinetic scheme of urea thermolysis is developed based on Ebrahimian'swork. Sequentially, the evaporation characteristics, decomposition efficiency of a single UWS droplet and deposit formation are simulated. As a result, the relation of evaporation time, relative velocity, exhaust temperature and droplet initial diameter is presented. Synchronously, it indicates that temperature is the decisive factor for urea thermolysis. Different temperatures result in different deposit components, and deposit yield is significantly influenced by temperature and decomposition time. The currentwork can provide guidance for designing urea injection strategy of SCR systems.
中医综合化腐生肌法治疗坏疽性脓皮病合并红斑型天疱疮1例

坏疽性脓皮病是一类复发性破坏性的溃疡,属难治性皮肤病,天疱疮是一种以皮肤、黏膜损害为主要表现的自身免疫性大疱性疾病,目前临床上糖皮质激素是其治疗最有效药物之一。笔者采用化腐生肌中医综合疗法治疗坏疽性脓皮病合并红斑型天疱疮1例,取得良好临床疗效,现报告如下。
改良顺行旗帜皮瓣修复手指指端缺损的疗效观察

目的探讨改良顺行旗帜皮瓣修复手指指端缺损的疗效。方法2012年3月- 2015年12月,收治21例(21指)指端缺损患者。男15例,女6例;年龄18 ~ 58岁,平均34岁。致伤原因:挤压伤11例,电锯伤6例,车床切削伤4例。损伤指别:示指9例,中指6例,环指4例,小指2例。指端创面均伴骨组织及肌腱外露,软组织缺损范围为1.0 cm×0.8 cm ~ 2.2 cm×1.8 cm。受伤至手术时间1.5 ~ 6.5 h,平均5.5 h。采用大小为1.1 cm×0.9 cm ~ 2.5 cm×2.0 cm的改良顺行旗帜皮瓣修复创面,并吻合指固有神经背侧支。供区植皮修复。结果术后除1例皮瓣远端出现水疱、结痂外,其余皮瓣顺利成活,创面均Ⅰ期愈合。供区植皮均顺利成活,切口Ⅰ期愈合。21例均获随访,随访时间6 ~ 18个月,平均14个月。皮瓣外观良好,术后6个月皮瓣两点辨别觉为6 ~ 9 mm,平均7.2 mm。末次随访时,按中华医学会手外科学会上肢部分功能评定试用标准评定:优14例,良6例,可1例;优良率95.2%。结论改良顺行旗帜皮瓣扩大了皮瓣切取面积,改善了皮瓣血管蒂旋转角度,是修复手指指端缺损较好方法。
The effect of laser surface texturing on the tribological performance of different Sialon ceramic phases

A tribological performance was carried out on different types of hot press Sialon ceramics regarding the phases, i.e., the α-Sialon phase, the β-Sialon phase, and the α/β-Sialon composite phase. The different phases of Sialon ceramics were analyzed by XRD patterns. For the tribological performance, the Sialon ceramics were laser textured and the starved lubrication method was applied with different dimple pitches under a load of 10 N at room temperature. The material having a dimple pitch of 200 mm shows the lowest coefficient of friction. The α/β-Sialon composite phase shows the least coefficient of friction i.e. 0.04 and 0.1 for the textured and polished (without being textured) samples, respectively. The Sialon ceramics show mild wear and therefore, the wear rate of the steel ball (mating partner) was taken into account for the wear analysis. The α-Sialon phase having a higher hardness shows the least wear in comparison to the α/β-Sialon composite phase and the β-Sialon phase.
Fabrication of a TiO_2-P25/(TiO_2-P25tTiO_2 nanotubes) junction for dye sensitized solar cells

The dye sensitized solar cell (DSSC), which converts solar light into electric energy, is expected to be a promising renewable energy source for today's world. In this work, dye sensitized solar cells, one containing a single layer and one containing a double layer, were fabricated. In the double layer DSSC structure, the under-layer was TiO_2-P25 film, and the top layer consisted of a mixture of TiO_2-P25 and TiO_2 nanotubes. The results indicated that the efficiency of the DSSC with the double layer structure was a significant improvement in comparison to the DSSC consisting of only a single film layer. The addition of TiO_2-P25 in the top layer caused an improvement in the adsorption of dye molecules on the film rather than on the TiO_2 nanotubes only. The presence of the TiO_2 nanotubes together with TiO_2-P25 in the top layer revealed the enhancement in harvesting the incident light and an improvement of electron transport through the film.
3种抗氧化剂对杜仲籽油的抗氧化作用

目的研究天然维生素E、特丁基对苯二酚、茶多酚对杜仲籽油的抗氧化作用。方法采用Schaal烘箱法,以过氧化值为指标,研究3种抗氧化剂的抗氧化作用。结果特丁基对苯二酚对杜仲籽油的抗氧化作用最强,并且与质量分数成正比,茶多酚次之,天然维生素E最弱。后两者作为特丁基对苯二酚的增效剂,对其协同作用也不明显。结论0.015%特丁基对苯二酚最适合作为杜仲籽油的抗氧化剂。
HPLC法比较河南8个产地葛根中5种成分

目的采用HPLC法比较河南8个产地(林州、焦作、嵩县、方城、信阳、禹州、西峡和淅川)葛根Pueraria lobata (Willd.) Ohwi中5种成分的含有量。方法分析采用Phenomenex Luna C_(18)色谱柱(250 mm × 4.6 mm,5 μm);以甲醇-0.1%甲酸为流动相,梯度洗脱;体积流量1.0 mL/min;检测波长250 nm;柱温25 ℃。结果3'-羟基葛根素、葛根素、3'-甲氧基葛根素、大豆苷、大豆苷元分别在0.029 ~ 0.86 μg (r = 0.999 8) 、0.050 ~ 1.5 μg (r = 0.999 4) 、 0.024 ~ 0.72 μg (r = 0.999 6) 、0.021 ~ 0.62 μg (r = 0.999 9) 、0.001 2 ~ 0.037 μg (r = 0.999 9)范围内线性关系良好,平均加样回收率(n = 6) 98.1% ~ 100.1%,RSD值1.03% ~ 1.95%。结论各成分含有量均具有一定差异,其中以嵩县和林州产者较高。
一种新型的具有“质谱标签”转移功能的光交联探针

蛋白质-蛋白质相互作用贯穿于整个生命进程,对其进行研究是生命科学领域的重点,并极具挑战性。光交联技术已经成为活体研究蛋白质-白质相互作用的一项有力工具。尤其是位点特异性的光交联技术,其利用遗传密码子扩增技术将光交联探针引入到目的蛋白的特定氨基酸位点上,可以在活细胞内实现实时高效地捕捉与诱饵蛋白相互作用的底物蛋白。
Effects of Cataract Surgery on Endothelium in Transplanted Corneal Grafts: Comparison of Extracapsular Cataract Extraction and Phacoemulsification for Complicated Cataract after Penetrating Keratoplasty

Background: The endothelium should be carefully evaluated when choosing a surgical technique for cataract removal. Therefore, we aimed to study the effects of different cataract surgery techniques on endothelial cell loss in transplanted corneal grafts. Methods: A total of 54 patients who received complicated cataract surgery in post-penetrating keratoplasty (PKP) eyes at the Shandong Eye Institute between February 2001 and June 2014 were included, and clinical records were reviewed. Baseline demographic details, clinical characteristics, endothelial cell density (ECD), and best-corrected visual acuity (BCVA) were recorded. Wilcoxon rank-sum test and Wilcoxon signed-rank test were used to test the equality of medians. A regression model was constructed to compare the reduced rate of ECD. Results: Of the 54 eyes included in this study, extracapsular cataract extraction (ECCE) was performed in 34 eyes of 33 patients (ECCE group) whereas phacoemulsification was performed in 20 eyes of 20 patients (phacoemulsification group). There was no significant difference in the median age (P = 0.081) or preoperative ECD (P = 0.585) between the two groups. At 6 months after cataract surgery, ECD in ECCE group was significantly higher than that in phacoemulsification group (P = 0.043). In addition, the endothelial cell loss rate in ECCE group was significantly lower than that in phacoemulsification group at 2 months (P = 0.018), 4 months (P < 0.001), and 6 months (P < 0.001) after cataract surgery. Endothelial cell loss rate after cataract surgery increased over the 6-month study duration in both ECCE group (P < 0.001) and phacoemulsification group (P < 0.001), but phacoemulsification resulted in a greater reduction in ECD than that of ECCE in transplanted corneal grafts (P < 0.001). There was no significant difference in postoperative BCVA between the two groups (P = 0.065). Conclusion: ECCE is more suitable than phacoemulsification in cataract surgery in complicated cataract after PKP.
Macrophage Inhibitory Cytokine-1 as a Novel Diagnostic and Prognostic Biomarker in Stage I and II Nonsmall Cell Lung Cancer

Background: Increased level of serum macrophage inhibitory cytokine-1 (MIC-1), a member of transforming growth factor-β superfamily, was found in patients with epithelial tumors. This study aimed to evaluate whether serum level of MIC-1 can be a candidate diagnostic and prognostic indicator for early-stage nonsmall cell lung cancer (NSCLC). Methods: A prospective study enrolled 152 patients with Stage I–II NSCLC, who were followed up after surgical resection. Forty-eight patients with benign pulmonary disease (BPD) and 105 healthy controls were also included in the study. Serum MIC-1 levels were measured using an enzyme-linked immunosorbent assay, and the association with clinical and prognostic features was analyzed. Results: In patients with NSCLC, serum protein levels of MIC-1 were significantly increased compared with healthy controls and BPD patients (all P < 0.001). A threshold of 1000 pg/ml of MIC-1 was found in patients with early-stage (Stage I and II) NSCLC, with sensitivity and specificity of 70.4% and 99.0%, respectively. The serum levels of MIC-1 were associated with age (P = 0.001), gender (P = 0.030), and T stage (P = 0.022). Serum MIC-1 threshold of 1465 pg/ml was found in patients with poor early outcome, with sensitivity and specificity of 72.2% and 66.1%, respectively. The overall 3-year survival rate of NSCLC patients with high serum levels of MIC-1 (≥1465 pg/ml) was lower than that of NSCLC patients with low serum MIC-1 levels (77.6% vs. 94.8%). Multivariate Cox regression survival analysis showed that a high serum level of MIC-1 was an independent risk factor for reduced overall survival (hazard ratio = 3.37, 95% confidential interval: 1.09–10.42, P = 0.035). Conclusion: The present study suggested that serum MIC-1 may be a potential diagnostic and prognostic biomarker for patients with early-stage NSCLC.
Monoclonal B-cell Lymphocytosis in a Patient with Wegener Granulomatosis: A Case Report and Update on 2016 World Health Organization Classification

The association between autoimmune disease and risk of monoclonal malignancy is well studied. However, monoclonal B-cell lymphocytosis (MBL) in patients with autoimmune diseases has rarely been reported. The newly published 2016 revision of the World Health Organization (WHO) classification of lymphoid neoplasms has officially accepted MBL as an independent disease entity. Herein, we present a case of Wegener granulomatosis (WG) with MBL. Through this case, the diagnosis and management of MBL as a less known condition to rheumatologists, especially under the background of an autoimmune disorder, is reviewed. Moreover, the association between autoimmune disease and risk of monoclonal malignancy is discussed.
土地利用格局优化管理信息系统的设计与开发

基于GIS技术的土地利用格局优化管理信息系统可以为土地资源开发管理和高效利用提供决策咨询平台。本文以黑龙江省为例,在分析其土地资源可持续利用需求的基础上,讨论了土地利用格局优化管理信息系统的架构和功能目标,分析了系统设计流程和实现技术。通过运用C#语言和ArcGIS Engine组件技术,并基于.NET框架的Microsoft Visual Studio 2010集成开发环境,实现了黑龙江省土地利用格局的查询、展示、分析及其重要的驱动力因素评价等功能,为土地资源可持续利用提供了技术支持。
智慧城市建设中建筑物数据库的设计

随着经济的飞速发展、城市化的不断推进,以及城市数量的增加和质量的提高,建设智慧城市已成为城市发展的必由之路,而建筑物管理是其核心建设内容之一。本文提出了一种建筑物数据库建设研究方案,讨论了建筑物数据库数据内容、数据库逻辑结构及物理结构设计,此外还对具体数据库系统分析设计方案进行了进一步论述,以供相关研究人员参考、讨论。
一种已知点不通视条件下的施工放样新方法

建筑场地往往狭小且变化快,导致施工前设置的已知点的通视性发生变化;同时,由于场地条件限制,难以找到一个同时与两个已知点都通视的点,导致无法采用后方交会法确定一个合适的临时工作基点来进行放样工作。本文提出了一种虚拟后方交会的方法,通过几何关系,确定了两个满足通视条件的临时基点的坐标值,进而指导施工放样。该方法可以利用常用的全站仪完成放样工作,工艺简单,为建筑密集区施工放样提供了一种新的选择。
面阵数字航测相机实验室校准装置的设计与实现

随着面阵数字航测相机在航空摄影领域的广泛使用,其参数校准成为亟待解决的关键问题。本文首先阐述了精密测角法的校准原理,在此基础上设计了基于大口径长焦距平行光管、精密测角转台和亚像素目标定位算法的面阵数字航测相机校准装置;其次通过对装置的误差分析,证明了该装置精度满足测绘行业标准中对数字航测相机的校准精度的要求;最后验证了该装置对面阵数字航测相机的实验室校准是可行的。
北京市空气质量时空特征分析

近年来,随着我国经济持续迅速发展,环境问题日益突出,空气污染日益严重,灰霾现象频发。研究空气质量演变的时空特征,揭示空气污染的成因具有十分重要的意义。本文基于自然正交函数(EOF)分析了北京市空气质量变化的时空特征,借助地理加权回归(GWR)揭示了其驱动力。研究结果表明:①北京市PM2.5 AQI年均空间分布由南到北有减小趋势;②北京市PM2.5 AQI异常呈现西北、东南反向分布;③POI特征对PM2.5 AQI的影响具有显著的南北差异,且在中心城区的影响作用比郊区大;④土地利用特征对PM2.5 AQI影响具有显著的南北差异;⑤路网特征对PM2.5 AQI具有正向作用,在中心城区的影响比郊区大。
精密三维测边网在FAST基准控制网中的应用

针对纯几何意义下的三维短边测边网中观测时段、仪器结构、量高误差及气象参数等因素对测距的影响进行了分析研究,提出了旨在提高斜距测量精度的措施,并在以FAST为例的全组合精密测边三维网的设计中得到了有效检验,通过精度估算,满足了FAST几何基准控制网精度需求,也为类似的大型工程中的精密几何测量提供了参考。
Dendroclimatic response of Abies spectabilis at treeline ecotone of Barun Valley, eastern Nepal Himalaya

A dendroclimatic study was conducted in the treeline ecotone of Barun Valley, eastern Nepal, to determine the tree-ring climate response and ring width trend of Abies spectabilis. A 160-year-old chronology, from 1850 to 2010, was developed from 38 tree-ring samples. No higher growth in recent decades was observed in tree-ring width in this area. The mean temperature of the current year in February and in the combined winter months of December, January, and February showed significant positive correlation with tree-ring width, although no significant correlation was found between tree-ring width and the precipitation pattern of the region. This tree-ring climate response result is different from that in other studies in Nepal, which could be attributed to location and elevation.
Characterization of a collection of Chinese fir elite genotypes using sequence-related amplified polymorphism markers

Chinese fir [Cunninghamia lanceolata (Lamb.) Hook] is a major timber tree species in China. In the present study, sequence-related amplified polymorphism(SRAP) markers were used to evaluate the polymorphisms, diversity, and relationships in a collection of Chinese fir elite genotypes (n = 103) from the Lechang provenance, an endangered provenance. Thirty-five SRAP primer combinations produced 620 bands among the tested 103 Lechang provenance genotypes and 17 non-Lechang provenance genotypes; 577 (93.1 %) of these were polymorphic, yielding an average of 16.5 polymorphic bands per primer combination. Of the SRAP primer combinations(n = 35), 14 ones identified C70.0 % of the 120 genotypes. The Me12–Em19 combination had the strongest discriminatory ability with 93.3 % of the genotypes identified. An UPGMA dendrogram further showed that most of the Lechang provenance genotypes (87.4 %) grouped together (Cluster A). The Lechang genotypes had a considerable amount of genetic variation with genetic similarity from 0.40 to 0.81. The current work may facilitate the management of the endangered Lechang Chinese fir provenance.
Estimating the production and mortality of fine roots using minirhizotrons in a Pinus densiflora forest in Gwangneung, Korea

The aim of this study was to estimate fine root production (FP) and fine root mortality (FM) at 0–10, 10–20, and 20–30 cm soil depths using minirhizotrons in a 75-year-old Pinus densiflora Sieb. et Zucc. forest located in Gwangneung, Korea. We developed the conversion factors(frame cm~(-2)) of three soil depths (0.158 for 0–10 cm, 0.120 for 10–20 cm, and 0.131 for 20–30 cm) based on soil coring and minirhizotron data. FP and FM were estimated using conversion factors from March 26, 2013 to March 2, 2014. The annual FP and FM values at the 0–30 cm soil depth were 3200.2 and 2271.5 kg ha~(-1) yr ~(-1), respectively. The FP estimate accounted for approximately 17 % of the total net primary production at the study site. FP was highest in summer (July 31–September 26), and FM was highest in autumn (September 27–November 29). FP was positively correlated with seasonal change in soil temperature, while FM was not related to that change. The seasonality of FP and FM might be linked to above-ground photosynthetic activity. Both FP and FM at the 0–10 cm depth were significantly higher than at 10–20 and 20–30 cm depths, and this resulted from the decrease in nutrient availability with increasing soil depth. The minirhizotron approach and conversion factors developed in this study will enable fast and accurate estimation of the fine root dynamics in P. densiflora forest ecosystems.
Tree encroachment into savannas alters soil microbiological and chemical properties facilitating forest expansion

Forests have been expanding over typical savanna sites for the past 3000 years in the Neotropics. Such invasion can produce a series of environmental modifications on typical savanna; however, it remains unclear how modifications in soil properties, caused by the encroachment of woody species, facilitate the expansion of forest ecosystems under dystrophic conditions. Here we examined chemical and microbiological changes associated with tree encroachment in oxisols of a Neotropical Savanna at Assis Ecological Station, Southeastern Brazil. We predicted that tree encroachment caused by typical forest species would cause significant changes in the chemical and microbiological properties of savanna soils. Soils were sampled at Assis Ecological Station, from savanna sites differing in tree encroachment (typical, dense and forested savanna) caused by decades of fire exclusion. We analysed vegetation leaf area index and leaf litter volume deposited in the studied plots and chemical (pH, organic matter, P, K, Ca, Mg, Al, NO_3~-, NH_4~+) and microbiological (microbial C biomass and dehydrogenase activity) properties of soils under distinct encroachment conditions. Most soil chemical properties did not change along the tree encroachment gradient; however, total P, soil organic matter, soil microbial C and dehydrogenase activity increased from typical savanna to forested savanna. The changes in soil organic matter and dehydrogenase activity were correlated with the values of leaf area index and litter volume along the encroachment gradient. Our results demonstrate that forest species can increase carbon and phosphorus supplies in tropical savanna soils.
Litterfall, decomposition and nutrient release of Shorea robusta and Tectona grandis in a sub-tropical forest of West Bengal, Eastern India

We studied leaf litter fall, decomposition and nutrient release patterns of Shorea robusta and Tectona grandis by using a litter bag technique to better understand the release pattern of nutrients to soil from leaf litter. Annual litterfall varied from 13.40 ± 2.56 t ha~(-1) a~(-1) for S. robusta to 11.03 ± 3.72 t ha~(-1) a~(-1) for T. grandis and the decay constant (k) of decomposed leaf litter was distinctly higher for T. grandis (2.70 ± 0.50 a~(-1)) compared to S. robusta (2.41 ± 0.30 a~(-1)). Biomass loss was positively correlated with the initial litter C, WSC, C/N and ash content in S. robusta and N, P and K concentration for T. grandis. Biomass was negatively correlated with lignin and L/N ratio for S. robusta and L, WSC, L/N and C/N ratio for T. grandis (P<0.01). Nutrient use efficiency (NUE) and nutrient accumulation index (NAI) of S. robusta was higher than for T. grandis. The retranslocation of bioelements from senescent leaves ranked as P>N>K. Annual N, P and K input to soil through litterfall differed significantly between the two species in the following order: N>K>P. S. robusta was superior in terms of K and P return and T. grandis was superior in terms of N return. The two tree species showed a similar patterns of nutrient release(K>P>N) during decomposition of their leaf litter. Nutrients of N, K and P were the primary limiting nutrients returned to soil through litterfall with important roles in soil fertility and forest productivity.