Ovulation and spawning induction in Caspian kutum Rutilus frisii kutum by administration of GnRHa and catecholaminergic pharmaceutical compounds with Ovaprim

The acceleration of final oocyte maturation and ovulation is recognized as a principal process in Caspian kutum Rutilus frisii kutum, a commercial and valuable species in Caspian Sea. The aim of this study was to evaluate the effects of catecholaminergic pharmaceutics which include Salbutamol (β₂‐adrenergic receptor agonist), Metoprolol (β₁‐adrenergic receptor antagonist), Clozapine and Olanzapine (the third generation of D₄ and D₂ dopamine receptor antagonists) which can be more efficient than the first and second generations, in combination with Buserelin ([D‐Ser(tBu)⁶,Pro⁹‐NEt]‐GnRHa) and Ovaprim (D‐Ala⁶,Pro⁹‐Net)‐sGnRH+Domperidone on ovulation and spawning induction in Caspian kutum. One hundred eight adult females were injected once with Buserelin Acetate (BUS) 5 μg kg^?1 BW, Ovaprim 0.5 mL kg^?1 BW, Salbutamol Sulphate (SLB) 4 mg kg^?1 BW, Olanzapine (OLZ) 5 mg kg^?1 BW, Clozapine (CZ) 12 mg kg^?1 BW and Metoprolol Tartrate (MTP) 5 mg kg^?1 BW, being divided into 12 groups: group 1, intact (negative control); group 2, Ovaprim (positive control); group 3, OLZ+SLB; group 4, OLZ+MTP; group 5, OLZ+BUS; group 6, CZ+SLB; group 7, CZ+MTP; group 8, CZ+BUS; group 9, OLZ+BUS+SLB; group 10, OLZ+BUS+MTP; group 11, CZ+BUS+SLB and group 12, CZ+BUS+MTP (N = 9). The results showed that the highest mean value in ovulation success, ovulation index, fertilization success, relative fecundity and the number of eggs belonged to Ovaprim treatment. On the other hand, spawning was successful in OLZ+BUS+SLB and CZ+BUS treatments (P < 0.05), whereas it was lower in CZ+MTP, CZ+BUS+MTP and OLZ+BUS than the other treatments. Therefore, it could be concluded that Clozapine and Olanzapine potentiated the effect of Buserelin treatment in ovulation and spawning induction, while Metoprolol blocked the stimulatory effects of GnRHa, Clozapine and Olanzapine. Salbutamol also can amplify stimulatory effect of all mentioned pharmaceutics.     

An assessment of carcass counting surveys with increasing time lapse following a simulated fish kill on a small upland stream

A simulated fish kill was conducted on a small upland stream in Northern Ireland by planting out hatchery‐produced brown trout Salmo trutta L. carcasses of various size categories. Standard, post‐fish kill, assessment walkover surveys were conducted over time intervals to determine the number of carcasses visible. The sample variance between individual surveyors was generally low, with good agreement between the observed counts for the three, discrete, size fractions of fish up to 72 hr after the simulated fish kill. Despite low discharge rates, shallow water and good accessibility to the experimental stream, only 52% of the small category fish (<8 cm L_F) were recorded 4 hr after the start of the simulated fish kill. Larger carcasses (>17 cm L_F) were more visible, and >90% were detected 48 hr after the start of the simulated fish kill. After 96 hr, all size fractions of carcasses had reduced significantly, and the variability between replicate surveys increased markedly.     

西藏鱼类增殖放流初报

西藏土著鱼类生长缓慢、性成熟晚并对环境变化高度敏感。近年来,受过度捕捞、水利工程建设等人类活动的影响,西藏渔业资源面临越来越大的压力。开展增殖放流活动是恢复当地渔业资源和生态平衡的重要手段。本文介绍了西藏鱼类增殖放流概况、苗种来源、放流实施、效果评估情况,分析了目前存在的基础研究不足、苗种来源不稳定、缺乏技术规范、效果评估有待加强等问题。提出了加强增殖放流基础设施建设和基础理论研究、建立西藏鱼类增殖放流与效果评估技术规范、重视放流后的管理与评估工作、加强专业技术人才队伍建设的建议。     

The role of lignin and cellulose in the carbon-cycling of degraded soils under semiarid climate and their relation to microbial biomass

A high level of biological degradation is usually observed in soils under semiarid climate where the low inputs of vegetal debris constraint the development of microbiota. Among vegetal inputs, cellulose and lignin are dominant substrates but their assimilation by the microbial community of semiarid soils is yet not understood. In the present study, ¹³C-labeled cellulose and ¹³C-labeled lignin (75 μg ¹³C g⁻¹ soil) were added to two semiarid soils with different properties and degradation level. Abanilla soil is a bare, highly degraded soil without plant cover growing on it and a total organic C content of 5.0 g kg⁻¹; Santomera soil is covered by plants (20% coverage) based on xerophytic shrubs and has a total organic C content of 12.0 g kg⁻¹. The fate of added carbon was evaluated by analysis of the carbon isotope signature of bulk soil-derived carbon and extractable carbon fractions (water and sodium-pyrophosphate extracts). At long-term (120 days), we observed that the stability of cellulose- and lignin-derived carbon was dependent on their chemical nature. The contribution of lignin-derived carbon to the pool of humic substances was higher than that of cellulose. However, at short-term (30 days), the mineralization of the added substrates was more related to the degradation level of soils (i.e. microbial biomass). Stable isotope probing (SIP) of phospholipid fatty acids (PLFA-SIP) analysis revealed that just a minor part of the microbial community assimilated the carbon derived from cellulose and lignin. Moreover, the relative contribution of each microbial group to the assimilation of lignin-derived carbon was different in each soil.     

Exploring connectivity between spawning and nursery areas of Mullus barbatus (L., 1758) in the Mediterranean through a dispersal model

Connectivity between spawning and nursery areas plays a major role in determining the spatial structure of fish populations and the boundaries of stock units. Here, the potential effects of surface current on a red mullet population in the Central Mediterranean were simulated using a physical oceanographic model. Red mullet larvae were represented as Lagrangian drifters released in known spawning areas of the Strait of Sicily (SoS), which represents one of the most productive demersal fishing‐grounds of the Mediterranean. To consider the effect of inter‐annual variability of oceanographic patterns, numerical simulations were performed for the spawning seasons from 1999 to 2012. The main goal was to explore connectivity between population subunits, in terms of spawning and nursery areas, inhabiting the northern (Sicilian‐Maltese) and southern (African) continental shelves of the SoS. The numerical simulations revealed a certain degree of connectivity between the Sicilian–Maltese and the African sides of the SoS. Connectivity is present in both directions, but it is stronger from the Sicilian–Maltese spawning areas to the African nurseries owing to the marine circulation features of the region. However, because the majority of the larvae are transported to areas unsuitable for settlement or outside the SoS, the dispersal process is characterized by a strong loss of potential settlers born in the spawning areas. These results are in agreement with the low genetic heterogeneity reported for this species in the Mediterranean Sea and support the existence of a metapopulation structure of red mullet in the SoS and the adjacent areas.     

猪粪施用量对红壤旱地理化性质及酶活性的影响

为研究猪粪的合理施用及其对红壤旱地地力提升的效应,利用在第四纪红壤旱地中连续3年分别施用0、7.5、15、30、45 t·hm~(-2)猪粪的小区定位试验,比较不同处理下菠菜和玉米地上部生物量、土壤相关理化性质、碳氮磷循环相关酶活性的差异。结果表明:菠菜和玉米地上部生物量、土壤有机质、土壤全量和速效态氮磷钾含量均随猪粪施用量的增加呈线性增加。当猪粪施用量达45 t·hm~(-2)时菠菜、玉米平均地上部生物量分别达到11.48、20.84 t·hm~(-2),土壤有机质和全氮、全磷含量分别达14.6、1.07、0.73 g·kg~(-1),土壤碱解氮、有效磷、速效钾含量分别达85.47、106.9、411.7 mg·kg~(-1),但与猪粪施用量为15和30t·hm~(-2)时土壤养分含量的差异不显著,而土壤中与碳氮磷循环相关的6种酶活性则与猪粪施用量呈线性相关,且在施用量为30或45t·hm~(-2)时出现显著差异;6种酶活性与土壤有机质、养分含量间均具有显著或极显著正相关关系。研究结果显示,第四纪红壤旱地在本试验猪粪施用量范围内,土壤有机质和养分含量、酶活性等指标均随施用量的增加而相应提高,作物地上部生物量亦呈线性增加,但同时须注意土壤速效态养分含量过高可能带来的氮磷流失加剧等问题。     

河北太行山区典型水土保持林乔木层生物量及碳储量研究

以河北太行山区4种典型水土保持林为研究对象,对混交林(栓皮栎-侧柏)、油松林、栓皮栎林和刺槐林的乔木层各器官生物量、含碳率以及碳储量进行比较研究。结果表明:混交林、油松林、栓皮栎林和刺槐林生物量分别为51.94,86.40,90.19,18.08t/hm^2,栓皮栎林和油松林生物量高于4种水土保持林生物量的均值(61.65t/hm^2),而混交林和刺槐林生物量分别占生物量均值的84.25%,29.33%。不同林分各器官在乔木层生物量中分配顺序均表现为树干>树根>树枝>树叶。4种典型林分各器官含碳率分别为45.16%~58.93%,58.48%~64.61%,51.16%~58.37%,52.35%~62.30%。4种典型林分碳储量为10.10~53.85t/hm^2。不同林分类型各器官碳储量与生物量呈正比关系,与生物量趋势基本相同,碳储量大小表现为油松林>栓皮栎林>混交林>刺槐林。     

γ-戊内酯/水复合溶剂体系中金属硫酸盐催化半纤维素定向转化制备糠醛

以廉价金属硫酸盐为催化剂,在γ-戊内酯/水复合溶剂中催化半纤维素定向转化制备糠醛,糠醛得率高达50.2%,半纤维素液化转化率达95.5%。在γ-戊内酯/水复合溶剂中,以金属硫酸盐为催化剂进一步研究了直接催化木质纤维生物质原料玉米芯和竹粉定向转化制备糠醛,其中糠醛得率分别达39.5%、29.7%,木质纤维原料液化转化率分别达86.5%、80.5%。     

基于宗地尺度的土地集约利用潜力评价及存量用地挖潜研究——以重庆市渝北区为例

为探究渝北区未来存量用地的挖潜方向,通过构建商服圈,并利用建筑、人口经济、交通和公共服务设施数据,从功能、强度和区位潜力3方面选取评价指标,结合层次分析法和熵权法确定其权重,计算渝北区城镇建设用地集约利用潜力,并依此识别可用于二次开发的宗地.结果表明:①渝北区划定商服圈总面积15 827.25 hm~2,因受地形、政策和城市双核心发展因素影响商服圈呈不规则形状;②用于潜力评价的宗地因城市开发过程中各类用地并存且未实现更新而未呈现同心圆模式;③渝北区可用于二次开发的城镇建设用地总面积为1 178.88 hm~2,主要布局于两路老城区南部、龙山—龙溪—龙塔街道西北部和创新经济走廊中部等区域.④渝北区公共管理与公共服务用地和商业服务业设施用地土地集约利用潜力较大,是未来改造盘活的主要用地类型.