检索结果-南通市图书馆

Spatial analysis of plant detritus processing in a Mediterranean River type: the case of the River Tirso Basin, Sardinia, Italy

引用

Journal of Environmental Sciences 2003年第2期15卷 227-240页

作者： maurizio pinna Franca Sangiorgio Alessio Fonnesu Alberto Basset Department of Biological and Environmental Sciences and Technologies University of LecceDepartment of Biological and Environmental Sciences and Technologies University of LecceDepartment of Biological and Environmental Sciences and Technologies University of LecceDepartment of Biological and Environmental Sciences and Technologies University of Lecce 73100 Lecce Italy73100 Lecce Italy73100 Lecce Italy73100 Lecce Italy

The river continuum concept represents the most general framework addressing the spatial variation of both structure and function in river ecosystems. In the Mediterranean ecoregion, summer drought events and dams constitute the main sources of local disturbance to the structure and functioning of river ecosystems occurring in the river basin. In this study, we analysed patterns of spatial variation of detritus processing in a 7th order river of the Mediterranean ecoregion(River Tirso, Sardinia-Italy) and in three 4th order sub-basins which were exposed to different summer drought pressures. The study was carried out on Phragmites australis and Alnus glutinosa leaf detritus at 31 field sites in seasonal field experiment Detritus processing rates were higher for Alnus glutinosa than for Phragmites australis plant detritus. Processing rates of Alnus glutinosa leaves varied among seasons and study sites from 0.006 d -1 to 0.189 d -1 and those of Phragmites australis leaves ranged from 0.0008 d -1 to 0.102 d -1, with the lowest values occurring at sites exposed to summer drought. Seasons and sites accounted for a significant proportion of such variability. Alder detritus decay rates generally decreased with increasing stream order, while reed detritus decay rates generally increased on the same spatial gradient. Summer drought events affected these spatial patterns of variation by influencing significantly the decay rates of both plant detritus. The comparisons among and within sub-basins showed strong negative influence of summer drought on detritus processing rates. Similarly, in the entire River Tirso basin decay rates were always lower at disturbed than at undisturbed sites for each stream order; decay rates of reed detritus remained lower at those sites even after the end of the disturbance events, while alder decay rates recovered rapidly from the summer drought perturbations. The different recovery of the processing rates of the two leaves could also

关键词： ecosystem processes spatial patterns disturbance Mediterranean ecosystem type

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Osmium complexes in catalysis of olefin hydrogenation and isomerization

引用

Chinese Journal of Catalysis 2016年第11期37卷 1824-1836页

作者： Giorgio Chelucci Gérard A.pinna Giansalvo pinna maurizio Solinas Barbara Sechi 意大利萨萨里大学农业系意大利萨萨里大学化学与药学系意大利生物化学研究所

This review focuses on the evolution of the use of osmium complexes as catalysts in the hydrogenation and isomerization of *** systems show good catalytic activities and selectivities in the hydrogenation of olefins via both dihydrogen and transfer *** systems therefore have significant potential to become a powerful tool in organic synthesis.

关键词： Osmium complexes Hydrogenation Transfer hydrogenation Alkene isomerization Olefins

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Acquired Pigmentation of Porcine Lymph Nodes: Dietary Polyphenolic Compounds as Biological Markers?

引用

Food and Nutrition Sciences 2012年第12期3卷 1703-1709页

作者： Walter pinna Maria Grazia Cappai Ilaria Sogos Giuseppa Nieddu maurizio Picciau Department of Agraria University of Sassari Sassari Italy Ex-Faculty of Veterinary Medicine University of Sassari Sassari Italy

The investigation aimed at exploring whether 1) high contents of natural polyphenols from the diet can induce pigment accumulation in lymph nodes (LNs);2) if so, whether polyphenolic compounds and derivates can be used as biological markers;3) and whether a lymph node from a specific anatomical region can be univocally identified, so as to be con sidered as a sentinel for the identification of the dietary origin of pigments. A paired match approach was used to switch 20 pigs (range of initial body weight, BW: 113 - 121 kg) to two experimental diets, for four weeks: ten pigs (pair housed) were fed with an experimental acorn based diet (acorns: 50% in the diet, as fed;total polyphenols, 78.1 g TP/Kg DM in the diet;tannic acid equivalent, 25.8 g TAE/kg DM);the remainder ten, received a pelleted complete diet for finishers (0% acorns in the diet). Daily feed intake in the last two weeks of the experimental feeding was recorded per pair of pigs in both groups of animals, showing an average intake of 610 mg TAE/kg BW/d. At an average final BW of between 127 to 137 kg, all pigs were slaughtered and LNs from different anatomical regions of the carcass were removed and analysed. At gross inspection, LNs from both groups displayed different grades of intensity and diffusion of pigmentation: a partial and incidental pigmentation was randomly detected in renal or sub-iliac LNs in the control group;a constant and uniform pigmentation of LNs was observed in acorns fed pigs: a dark brown staining diffused to the whole LN associated with a brownish colour of the muscles was found systematically. At light microscope intracytoplasmic granules were found in macrophages and dendritic cells from both groups, but, at confocal laser analysis, an intense auto-fluorescence was observed in medial-iliac LNs from the carcasses of acorn-fed pigs (green emission). However, intracellular sources of blue and green fluorescence at different wavelengths, likely due to tryptophan, indoleamine and der

关键词： Acorns Auto-Fluorescence Lymph Node Marker Total Polyphenols

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：