Effects of conventional and organic feed on the mineral composition of cultured European sea bass (Dicentrarchus labrax)

European sea bass (Dicentrarchus labrax) is a widely consumed marine fish in Mediterranean areas, and different farming techniques are applied for fish culturing to satisfy the growing demand for seafood. The aim of this study was to investigate the effects of conventional and organic feed on the quality of cultured European sea bass (Dicentrarchus labrax) collected during the growth period. The concentrations of ash, moisture, essential macro‐elements (Ca, K, Mg, Na and P), micro‐elements (Co, Cr, Cu, Fe, Mn, Ni and Zn) and toxic elements (As, Cd, and Pb) were determined in feeds and in fillets of cultured fish. The results were compared to those obtained from wild sea bass. Results showed that the differences between organic diet‐fed and conventional diet‐fed sea basses varied in relation to the specific element measured and the growth period. The former showed higher concentration of Fe, Mg and Cr, and lower Na content. The amount of P, Na, Fe, Cu and Cr in wild sea bass was significantly (P ≤ 0.05) higher than that found in farmed fish. The levels of toxic elements in cultured sea bass were always within the allowed limit for fishery products. Wild samples had significantly (P ≤ 0.05) higher content of arsenic and lead than farmed sea bass. Cultured fish represent a valuable dietary source of essential macro‐ and micro‐elements. Controlled rearing systems and feedings were related to a decrease in the presence of some toxic metals in cultured fish compared with wild fish.     

高尔夫球手地方依恋符号性元素的识别与运用

运用隐喻抽取技术对高尔夫球手地方依恋的符号性元素进行了识别与定量研究。结果表明,高尔夫球手地方依恋有22个符号性元素,这些元素可分为风格、地理、参与、接待和文化五类,它们给球手带来"友谊"、"健康"、"愉悦"、"品质高"、"风景美"的终极体验。经营者要充分利用符号性元素的意义,着重打造球场基础设施、园林景观、服务接待和球会文化;积极挖掘联结构念的耦合价值,实现球手与球场的符号互动;主动创设高尔夫球手游憩氛围情境,避免球手地方依恋的中断或转移;结合球会自身特点,适时进行符号化运作。     

海南岛甘什岭热带低地雨林植物组成与地理成分

为揭示海南岛甘什岭热带低地雨林区域植物群落特征、性质和规律,以期为进一步分析生物多样性保育与恢复策略及生态服务功能评估等提供科学依据,在海南岛南部甘什岭自然保护区选择典型低地雨林建立1 hm~2固定样地,进行立地因子和植被调查,并研究其物种组成与地理成分。结果表明:维管植物隶属于65科150属213种,种子植物63科148属211种,分别占海南岛和全国种子植物总科、属、种的32.66%、19.29%,13.56%、4.69%和7.65%、0.78%~0.81%;优势科明显,单种科36个,寡种科24个,共占总科数的92.31%;属内种的变化范围为1~6,单种属最多,占总数的76.00%;科和属的分布区类型均以泛热带分布为主,热带性质占绝对优势,这不同于尖峰岭山地雨林热带-亚热带过度性明显的特点;根据种-面积曲线研究表明,甘什岭热带低地雨林最小取样面积为范围在3 600~6 400 m~2之间,其上限高于海南岛霸王岭热带山地雨林的4 000 m~2最小面积;相较于山地雨林,其植物种类较丰富,地理成分更复杂。     

Effect of climate change on Spodoptera litura Fab. on peanut: A life table approach

Investigations were conducted to understand the direct effects of rising temperature and the host-mediated effects of elevated CO₂ (eCO₂) on Spodoptera litura (Fabricius) (Noctuidae: Lepidoptera). This study involved i. the construction of life tables of S. litura at six constant temperatures viz., 20, 25, 27, 30, 33 and 35°C ± 0.5 °C reared on peanut (Arachis hypogaea L.) grown under eCO₂ (550 ppm) concentration in open top chambers ii. Estimation of threshold temperatures and thermal constants and iii. Prediction of the pest scenarios during near and distant future climate change periods. Significantly lower leaf nitrogen, higher carbon and a higher relative proportion of carbon to nitrogen (C:N) were observed in peanut foliage grown under eCO₂ over ambient CO₂ (aCO₂). The mean development time (days) of each stage, egg, larva, pupa, pre-oviposition and total life span decreased from 20 to 35 °C temperature on eCO₂ foliage. The thermal requirement of S. litura from egg to egg (within the range of 20 °C–35 °C) was 538.5 DD on eCO₂ as against 494.5 DD on aCO₂ foliage. Finite (λ) and intrinsic rates of increase (r_m), net reproductive rate (R_o), mean generation time (T) and doubling time (DT) of S. litura varied significantly with temperature and CO₂ and were found to have quadratic relationships with temperature. The present results on life table parameters estimated by the bootstrap technique showed that the ‘r_m’ values of S. litura on eCO₂ foliage were higher than those in the literature indicating a significant influence of eCO₂. The reduction of ‘T’ was noticed from a maximum of 50 days at 20 °C to minimum of 22 days at 35 °C and ‘λ’ which is the indicator of reproductive value of new eggs was highest at 35 °C and showed a negative relationship with temperature. The data on these life table parameters were plotted against temperature and two non-linear models developed for both CO₂ conditions and used for predicting the pest scenarios. Prediction of pest scenarios based on PRECIS A1B emission scenario data at eleven peanut growing locations of the country during near future (NF) and distant future (DF) climate change periods showed an increase of ‘r_m’ and ‘λ’ with varied ‘R_o’ and reduced ‘T’. The present results indicate that temperature and CO₂ are vital in influencing the growth and life table parameters of S. litura and that pest incidence is likely to be higher in the future.     

马铃薯种植栽培管理技术要点研究

在粮食作物中，马铃薯属于关键，诸多国家都是马铃薯产国，我国马铃薯种植栽培面积也十 分广泛，所以，需要针对于马铃薯特征全面普及其种植与栽培技术，以此来保障马铃薯总产量。     

翁源青云山自然保护区维管束植物区系特征分析

青云山省级自然保护区位于韶关翁源县的东南部,本研究在查阅文献、历史标本的基础上,对本区进行全面踏查、标本采集并鉴定,从而进行植物物种多样性编目和区系分析。结果表明：青云山自然保护区有维管束植物1336种（含种下分类单位）,其中石松类和蕨类植物132种,隶属于62属24科,裸子植物6种,隶属于4属4科,被子植物1198种,隶属于588属148科;本区的表征科主要以樟科（Lauraceae）、壳斗科（Fagaceae）、冬青科（Aquifoliaceae）等为主。植物区系地理组成复杂,主要以热带、亚热带为主,且热带、亚热带的过渡性质明显。从中国特有种的分布情况来看,该地区与湖南南部、广西东北部、江西西南部联系较为紧密,体现了南岭山脉植物区系的一致性与整体性;珍稀濒危植物共计48种;植被具有中亚热带向南亚热带过渡的特征。青云山自然保护区植物物种丰富度高、植被类型多样,建议将园洞、青山口等珍稀濒危植物分布较集中的地区列为优先保护区域。     

Anthropogenically disturbed potentially toxic elements in roadside topsoils of a suburban region of Bishkek,Central Asia

The ecological environment in Central Asia is vulnerable to pressure from human activity due to the physical geography and climatic fragility of this region. A set of indicators suitable for the future assessment of this pressure needs to be proposed. Thirty‐six topsoil samples (0–5 cm) were collected from roadsides in a suburban region of Bishkek, the capital of the Kyrgyz Republic in Central Asia, and a risk assessment of anthropogenically disturbed potentially toxic elements (PTEs) was systematically conducted with classic statistical methods. The results of detrended correspondence analysis and principal component analysis clearly showed that topsoil samples with high contents of PTEs (Pb, Zn and Cu) were strongly affected by traffic within a distance threshold of 200 m and that anthropogenic effects decreased significantly with increasing distance from the highway. The enrichment factor and anthropogenic contribution for Pb were the highest among the three PTEs, with average values of 2.0% and 47.4%, respectively, suggesting enrichment. However, the results of the human health risk assessment also indicated that noncarcinogenic risks did not occur for any of the anthropogenic PTEs. The reported method provides a new systematic pathway to reveal anthropogenic influences on the geochemical composition of soil. The conclusions of this work will be highly valuable as important guidelines for agriculture, and the results of the PTE contents will provide a scientific basis for soil collection in future studies.     

传统图形元素在食用菌包装创意设计中的运用

通过研究食用菌包装中传统图形元素的创意设计,可以使食用菌产品与现代消费者的需求更加贴合,进一步拓展食用菌消费市场。融合地域特色传统文化,满足现代人的审美观念,对传统图形元素进行有效创新,并使用科学的方法进行设计,更好的凸显地域特色文化内涵。     

佛山岭南天地旧改项目中开放空间的特色分析

近年来,国内出现了不少基于城市老街区改造为商业街区的项目。通过对佛山岭南天地项目中有代表性的广场、街道、建筑等节点进行调研,选取开放空间的3个特色要素——空间形态和尺度,传统装饰元素,植物和水景布置,探析"新天地"模式中开放空间营造的特色手法,包括保持街巷形态和宜人尺度,增强街区公共属性;保护传统建筑构件,利用传统材料、技术;保留古树,并结合植物和水景布置,形成多层次的景观系统等。     

岩石-土壤-四川牡丹元素迁移体系中的微生物效应

[目的]研究四川牡丹岩土环境背景以及微生物在元素迁移过程中的作用,为了解营养元素的表生地球化学行为规律及微生物在元素迁移体系中的作用提供理论依据。[方法]利用ICP-OES测定四川牡丹生境母岩、土壤以及种子的大量(P,S,K,Ca,Na,Mg,Al)、微量(Fe,Mn,Cu)营养元素含量,同时利用Illumina高通量测序技术测定根际土壤中细菌、真菌的组成和结构。[结果](1)四川牡丹生长土壤以弱碱富钙为主要特征,元素组成基本保留了母岩特征;(2)元素从母岩到土壤中的迁移富集系数排序为:CaNaSPMgKAlFeMnCu,植物吸收系数排序为:PSKCuMgCaNaMnFeAl;(3)碱土金属淋溶率和铝铁率对土壤细菌的多样性(Alpha)影响显著,但对真菌的影响不显著;(4)P,Mn的迁移主要受母岩控制,而Ca,Mg,Fe,S等元素的迁移富集受到了微生物的影响。[结论]细菌和真菌在元素迁移体系中的作用相似,主要参与Fe,S,Mg,Ca的相关反应过程。