Solvent Effects are Important in Elucidating Radical-Scavenging Mechanisms of Antioxidants. A Case Study on Genistein

Abstract

In two recent researches on antioxidant mechanisms of flavonoids and isoflavonoids, quantum chemical method was employed to calculate the proton dissociation energies, the bond dissociation energies and the ionization potentials for the phenols and derived radicals to help determine the radical-scavenging mechanisms. As the solvent effect was left out of consideration, the conclusion drawn from the calculation incurred some controversies. In the current study, we re-calculated the parameters for genistein and its anion by employing a B3LYP/6–311+G(d,p)//6–31G(d,p) method with solvent effect. Accordingly, a more reasonable explanation on the experimentally observed behavior of genistein as a radical scavenger was obtained. Therefore, solvent effect should be considered in the investigation of radical-scavenging mechanisms of antioxidants in polar solvents.     

Effects of Canopy Cover and Ground Disturbance on Establishment of an Invasive Grass in an Australia Savanna1

Andropogon gayanus (gamba grass) is an introduced pasture grass that threatens Australia's tropical savannas by modifying fire regimes and species composition. To understand the establishment requirements of A. gayanus, we undertook a field experiment to determine the effect of canopy cover and ground layer disturbance on seedling emergence and survival. Seed was sown under three canopy treatments (undisturbed, artificial canopy gap, and natural canopy gap) and under three ground layer treatments (Control, Vegetation disturbed, and Soil disturbed). Results have shown that A. gayanus can establish and survive regardless of canopy cover or ground disturbance, although such site disturbances will increase establishment success. Disturbance of both the overstorey canopy and the ground layer increased A. gayanus emergence, whereas seedling survival to 12 mo after seed sowing was affected by ground layer disturbance alone. Disturbance of the canopy increased light transmission, which may have promoted germination. Ground layer disturbance may also have increased light transmission and suitable sites for establishment, and reduced competition for resources, such as water and nutrients. The ability of A. gayanus to spread along disturbed areas, establish in relatively undisturbed savannas, and resprout after fire within 6 mo after seedling emergence suggests that this species will become increasingly widespread in Australia's tropical savannas. Its control is urgently required.     

农田边界生物多样性保护功能的初步研究——以北京东北旺步甲群落多样性研究为例

农田边界是农田间的过渡带 ,包含了树篱、防护林、草皮 (带 )、墙、篱笆、沟渠、道路、作物边界带等景观要素[3] 。许多研究表明 ,农田边界在保护生物多样性方面有着重要的作用。Ｄｅｎｎｉｓ等[7] 的研究表明 ,通过为节肢动物提供多样、稳定的栖息地和越冬场所 ,增加农田中节肢动物的多样性。Ｈｏｌｌａｎｄ等[12 ] 的研究也表明 ,林地边界在农业生态系统中能起到保护生物多样性的作用 ,这种作用不仅使林地中有较高的多样性 ,而且还使相邻农田生物多样性增加。同时 ,多样化的农田生态系统比纯作系统具有更为丰富和多样的害虫天敌[6 ] 。国…     

Biodiversity and Nutrition in Rice-Based Ecosystems; the Case of Lao PDR

This paper presents results from a year-long household survey in which the aquatic resource collection and consumption activities of 240 households across Lao PDR were studied to assess the diversity of species used, their role in household food security and the overall importance of ricefield habitats in this respect. Results show that aquatic biodiversity, under threat in rice-based ecosystems, plays a larger role in household consumption than previous estimates. More than 90 % of these resources are collected by households themselves and the greatest quantities from ricefield habitats. This seasonal aquatic environment is therefore the principal habitat from which households acquire aquatic animals, both to eat fresh and to process and store for use during nutritionally vulnerable times of year. The importance of these habitats therefore goes far beyond their use for rice production and this multi-functionality needs to be understood and addressed in agricultural, conservation and food security policy.     

Reconstructing Anthropogenic Disturbance Regimes in Forest Ecosystems: A Case Study from the Swiss Rhone Valley

Anthropogenic disturbances of forest ecosystems are increasingly recognized as fundamental ecological processes with important long-term implications for biogeochemical cycles and vegetation patterns. This article aims at reconstructing the extent and intensity of the two most common types of traditional forest uses—forest litter collecting and wood pasture—in the Swiss Rhone valley (Valais) by (i) identifying the spatiotemporal patterns, and (ii) modeling the biomass removal through these practices. Detailed information on agricultural practices and socio-economic context were essential to develop reliable estimates of anthropogenic disturbance regimes. In the Valais, predominately goats and sheep grazed in the forests. The intensity of grazing was a function of the number of grazing animals and the available grazing area. Forest litter was used as bedding for farm animals during the winter. Key factors determining the intensity of litter collecting were the number of animal units, the amount of available substitute products (straw), and the area where litter raking could be practiced. The results show that wood pasture and forest litter collecting were practiced on a significant proportion of the forested landscape in the Valais up to the second half of the 20th century. Until the implementation of forest management plans in the 1930s, almost half of the forests in the study area were affected by wood pasture and/or forest litter collecting. The regulations in the management plans led to an essential reduction of the area available for these traditional practices but likewise to an increased pressure on the remaining areas. The results suggest that the notion of a slow but steady disappearance of traditional non-timber forest uses and the associated effects on forest ecosystems is oversimplified. Quantitative reconstructions of biomass output resulting from these practices confirm the importance of traditional non-timber forest uses for ecosystem development in this region. Furthermore, it is very likely that similar effects have been widespread throughout regions with similar natural and socio-economic context, for example, throughout a significant proportion of the European Alps. This study underlines the importance of environmental history for ecological sciences as well as for forest management and conservation planning.     

Gravel Bars Can Be Critical for Biodiversity Conservation: A Case Study on Scaly-Sided Merganser in South China

Gravel bars are characteristic components of river landscapes and are increasingly recognized as key sites for many waterbirds, though detailed studies on the ecological function of gravel bars for waterbirds are rare. In this study, we surveyed the endangered Scaly-sided Merganser Mergus squamatus along a 40 km river section of Yuan River, in Central China, for three consecutive winters. We derived the landscape metrics of river gravel bars from geo-rectified fine resolution (0.6 m) aerial image data. We then built habitat suitability models (Generalized Linear Models—GLMs) to study the effects of landscape metrics and human disturbance on Scaly-sided Merganser presence probability. We found that 1) the Scaly-sided Merganser tended to congregate at river segments with more gravel patches; 2) the Scaly-sided Merganser preferred areas with larger and more contiguous gravel patches; and 3) the number of houses along the river bank (a proxy for anthropogenic disturbance) had significantly negative impacts on the occurrence of the Scaly-sided Merganser. Our results suggest that gravel bars are vital to the Scaly-sided Merganser as shelters from disturbance, as well as sites for feeding and roosting. Therefore, maintaining the exposure of gravel bars in regulated rivers during the low water period in winter might be the key for the conservation of the endangered species. These findings have important implications for understanding behavioral evolution and distribution of the species and for delineating between habitats of different quality for conservation and management.     

A Case Study on Human Upper Limb Modelling for Dynamic Simulation

Modelling consists of developing a representation of the properties of an object or a phenomenon with respect to the goals of its analysis. In this paper, the procedure presented is that followed in the CHARM project for human upper limb modelling with respect to the project constraints on the model implementation and simulation. The objective is to develop a Comprehensive Human Animation Resource Model allowing the simulation of human motion, including the finite element simulation of soft tissue deformation and muscular contraction. Generally, models are presented based on assumptions left for a fortiori validation. The a priori considerations which lead to these assumptions are rarely detailed. Here, the aim is to form a basis for the choices and assumptions which are to be made prior to the validation. The analysis is based on the general approach for the modelling of multi-body deformable systems as well as on previous studies on the human upper limb.     

Analysis of Photosynthetic Activity at the Leaf and Canopy Levels from Reflectance Measurements: A Case Study

The photochemical reflectance index (PRI), based on reflectance signatures at 531 and 570 nm, and associated with xanthophyll pigment inter-conversion and related thylakoid energisation, was evaluated as an indicator of photosynthetic function in a Mediterranean holm oak (Quercus ilex L.) coppice. The chlorophyll fluorescence pulse-amplitude-modulation and the eddy correlation techniques were used to estimate the photosystem 2 photochemical efficiency of leaves and the CO₂ flux over the canopy, respectively. The reflectance and fluorescence techniques yielded identical estimates of the photosynthetic activity in leaves exposed to dark-light-dark cycles or to a variable irradiance in laboratory. However, there was no such correlation between photosynthetic performance and PRI when applied to a sun-exposed canopy in field conditions. Fluorescence profiles inside the canopy and especially a helpful use of multispectral reflectance imaging highlight the limitations of such method.     

Risk Assessment of Human Activities on Protected Areas: A Case Study

No study has been done on the impact of anthropogenic risks on protected areas. This may be due to complexity and diversity of risk assessment indices. In this research, using multicriteria decision-making methods, qualitative and complex indices were converted to simple and quantitative indices by which anthropogenic risks affecting the Helleh Protected Area in Iran were analyzed. To this end, a questionnaire was prepared and delivered to Delphi panelists consisting of environmental expertise. In order to prioritize the identified risks, Technique for Order Preference by Similarity to Ideal Solution (TOPSIS), Analytical Hierarchy Process (AHP), and Simple Additive Weighting Technique (SAW) were used as a subset of Multiple Attribute Decision-making methods (MADM). In this study, risk factors were evaluated using three criteria of severity, probability of occurrence, and sensitivity of the recipient environment. In order to reach enough transcendence (consensus on priority of risks), an integrated approach comprising average, Borda, and Copeland methods was used. The obtained results suggested that “dam inundation upstream of the study area” is a top-priority risky factor threatening the wetland. “Stopping water pumps from the wetland” and “use of modern irrigation systems” were recommended as the most effective managerial strategies to control the identified risk.     

广州市蕨类植物物种多样性研究

依据文献、标本与野外调查,简要回顾了历史上记录的广州蕨类植物,阐明了广州目前分布的蕨类植物的种类、区系特点、生态与地理分布、以及珍稀蕨类植物的种类与保护现状.广州地区有蕨类植物37科82属176种,其中乔芒萁(Dicranopteris gigantea)、刺边膜蕨(Hymenophyllm spinosum)和裸果鳞毛蕨(Dryopteris gymnosora)为广东分布新记录.广州蕨类植物区系以金星蕨科(Thelypteridaceae)、鳞毛蕨科(Dryopteridaceae)、水龙骨科(Polypo-diaceae)、蹄盖蕨科(Athyriaceae)和风尾蕨科(Pteridaceae)的植物最为丰富,没有本地特有种,亚洲热带亚热带分布成分和东亚分布成分占绝对优势.这176种蕨类植物中,约80%的种类生活在密林阴湿生境,约20%生活在疏林或灌草丛干旱生境,只有2种水生蕨类植物.在水平分布上,广州蕨类植物呈北多南少的分布格局,约90%的种类汇集在广州东北部的从化山区,74种在广州仅见于该山区.从物种多度上看,个体数量多(Cop2)的有33种,尚多(Cop1)的有48种,稀少(Sp)的有53种,很少(So1)的有41种.华南马尾杉(Phlegmariurus austrosbzicus)、福建观音座莲(Angiopteris fokiensis)、刺边膜蕨(Hymenophy llum spmosum)、粗齿桫椤(Alsophila denticulata)、小黑桫椤(A.m etteniana)、黑桫椤(A.podophylla)、桫椤(A.spinulosa)、水蕨(Ceratopteris thdictroides)、羽裂叶双盖蕨(Diplazium tomitaroanum)、闽浙圣蕨(Dictyocline mingchegensts)、微毛凸轴蕨(Metathelypteris adscendens)、峨眉茯蕨(Leptogramma scdlanll)、苏铁蕨(Brainea insignis)、珠芽狗脊(Woodwardia prolifera)和黑鳞复叶耳蕨(Arachniodes nigrospinosa)等15种被评估为广州的珍稀植物,它们亟待有效的保护.     

Past Climate Change and Plant Evolution in Western North America: A Case Study in Rosaceae

Species in the ivesioid clade of Potentilla (Rosaceae) are endemic to western North America, an area that underwent widespread aridification during the global temperature decrease following the Mid-Miocene Climatic Optimum. Several morphological features interpreted as adaptations to drought are found in the clade, and many species occupy extremely dry habitats. Recent phylogenetic analyses have shown that the sister group of this clade is Potentilla section Rivales, a group with distinct moist habitat preferences. This has led to the hypothesis that the ivesioids (genera Ivesia, Horkelia and Horkeliella) diversified in response to the late Tertiary aridification of western North America. We used phyloclimatic modeling and a fossil-calibrated dated phylogeny of the family Rosaceae to investigate the evolution of the ivesioid clade. We have combined occurrence- and climate data from extant species, and used ancestral state reconstruction to model past climate preferences. These models have been projected into paleo-climatic scenarios in order to identify areas where the ivesioids may have occurred. Our analysis suggests a split between the ivesioids and Potentilla sect. Rivales around Late Oligocene/Early Miocene (∼23 million years ago, Ma), and that the ivesioids then diversified at a time when summer drought started to appear in the region. The clade is inferred to have originated on the western slopes of the Rocky Mountains from where a westward range expansion to the Sierra Nevada and the coast of California took place between ∼12-2 Ma. Our results support the idea that climatic changes in southwestern North America have played an important role in the evolution of the local flora, by means of in situ adaptation followed by diversification.     

A Systematic Review on the Contributions of Edible Plant and Animal Biodiversity to Human Diets

The sustainable use of natural and agricultural biodiversity in the diet can be instrumental to preserve existing food biodiversity, address malnutrition, and mitigate adverse effects of dietary changes worldwide. This systematic review of literature summarizes the current evidence on the contribution of plant and animal biodiversity to human diets in terms of energy intake, micronutrient intake, and dietary diversification. Peer-reviewed studies were searched in ten databases using pre-defined search terms. Only original studies assessing food biodiversity and dietary intake were included, resulting in a total of 34 studies. 7, 14, and 17 studies reported information in relation to energy intake, micronutrient intake, and dietary diversification, respectively. In general, locally available foods were found to be important sources of energy, micronutrients, and dietary diversification in the diet of particularly rural and forest communities of highly biodiverse ecosystems. The current evidence shows local food biodiversity as important contributor of nutritious diets. Findings are, however, limited to populations living in highly biodiverse areas. Research on the contribution of biodiversity in diets of industrialized and urban settings needs more attention. Instruments are needed that would more appropriately measure the dietary contribution of local biodiversity.     

Conservation Planning for Offsetting the Impacts of Development: A Case Study of Biodiversity and Renewable Energy in the Mojave Desert

Balancing society’s competing needs of development and conservation requires careful consideration of tradeoffs. Renewable energy development and biodiversity conservation are often considered beneficial environmental goals. The direct footprint and disturbance of renewable energy, however, can displace species’ habitat and negatively impact populations and natural communities if sited without ecological consideration. Offsets have emerged as a potentially useful tool to mitigate residual impacts after trying to avoid, minimize, or restore affected sites. Yet the problem of efficiently designing a set of offset sites becomes increasingly complex where many species or many sites are involved. Spatial conservation prioritization tools are designed to handle this problem, but have seen little application to offset siting and analysis. To address this need we designed an offset siting support tool for the Desert Renewable Energy Conservation Plan (DRECP) of California, and present a case study of hypothetical impacts from solar development in the Western Mojave subsection. We compare two offset scenarios designed to mitigate a hypothetical 15,331 ha derived from proposed utility-scale solar energy development (USSED) projects. The first scenario prioritizes offsets based precisely on impacted features, while the second scenario offsets impacts to maximize biodiversity conservation gains in the region. The two methods only agree on 28% of their prioritized sites and differ in meeting species-specific offset goals. Differences between the two scenarios highlight the importance of clearly specifying choices and priorities for offset siting and mitigation in general. Similarly, the effects of background climate and land use change may lessen the durability or effectiveness of offsets if not considered. Our offset siting support tool was designed specifically for the DRECP area, but with minor code modification could work well in other offset analyses, and could provide continuing support for a potentially innovative mitigation solution to environmental impacts.     

Unveiling the Diet of Elusive Rainforest Herbivores in Next Generation Sequencing Era? The Tapir as a Case Study

Characterizing the trophic relationships between large herbivores and the outstanding plant diversity in rainforest is a major challenge because of their elusiveness. This is crucial to understand the role of these herbivores in the functioning of the rainforest ecosystems. We tested a non-invasive approach based on the high-throughput sequencing of environmental samples using small plant plastid sequences (the trnL P6 loop) and ribosomal ITS1 primers, referred to as DNA metabarcoding, to investigate the diet of the largest neotropical herbivore, the lowland tapir. Sequencing was performed on plant DNA extracted from tapir faeces collected at the Nouragues station, a protected area of French Guiana. In spite of a limited sampling, our approach reliably provided information about the lowland tapir''s diet at this site. Indeed, 95.1% and 74.4% of the plant families and genera identified thanks to the trnL P6 loop, respectively, matched with taxa already known to be consumed by tapirs. With this approach we were able to show that two families and eight new genera are also consumed by the lowland tapir. The taxonomic resolution of this method is limited to the plant family and genera. Complementary barcodes, such as a small portion of ITS1, can be used to efficiently narrow identifications down to the species in some problematic families. We will discuss the remaining limitations of this approach and how useful it is at this stage to unravel the diet of elusive rainforest herbivores and better understand their role as engineers of the ecosystem.     

海南铜铁岭热带低地雨林群落特征研究

根据样方调查的结果,分析了海南岛铜铁岭热带低地雨林群落的种类组成、区系成分、外貌特征和年龄结构.结果表明,在2600m2样方中,有维管束植物88科186属258种;优势科为番荔枝科、大戟科、茜草科、樟科、芸香科、桃金娘科等.区系地理成分可分为10种类型,热带分布的属占绝对优势,达94.89%.群落的生活型以高位芽为主,群落外貌主要由革质、单叶和中型叶为主的常绿阔叶林高位芽植物决定.群落成层现象明显,可分为乔木层、灌木层、草本层,乔木层可再划分为2～3个亚层.种群频度分布规律为A>B>C>D>E 按Raunkiaer将频度指数划分 ,属于A级的种类占优势,为总种数的70.54%,大部分种类具有10个以下个体.乔木径级分布呈金字塔形,小径级占优势.     

Investigating the Use of Fractional Replication and Taguchi Techniques in Cryopreservation: A Case Study Using Orthodox Seeds of a Tropical Rainforest Tree Species

Cryopreservation is increasingly important for conserving endangered species including tropical rain forest germplasm where optimal cryopreservation protocols must be established rapidly sacrificing little germplasm. Currently, full factorial experiments analysed by ANOVA establish optimal conditions. However, these experiments can contain many treatment combinations whilst ANOVA identifies significant effects without guaranteeing to find robust optimal conditions. Taguchi optimization techniques efficiently identify robust conditions through fractional factorial experiments with an appropriate signal to noise ratio (SNR). This paper reports for the first time the use of Taguchi techniques in cryopreservation. An orthodox seed (Cassia siamea Lam.) was used to guarantee sufficient data to compare full and fractionally replicated experiments analysed using both ANOVA and SNR. For sprouting day (smaller is better), identical significant main effects were found for all experimental sizes for ANOVA and SNR. The 1/4 replicate did not allow investigation of interaction terms, but the significant main effects were the same for larger experiments. For shoot to root ratio (nominal is best), a significant main effect was found for all experimental sizes using ANOVA. This was also found using SNR, which identified additional significant main effect and interactions. No significant effects were found for dry weight (larger is better). We show smaller experiments are possible, provided important two level interactions are analysed. Differences determining the optimal treatment combination were found between ANOVA and SNR; with the Taguchi choice provides more robust solutions. Taguchi optimization techniques are recommended when germplasm is scarce and/or the experiment needs to be conducted rapidly.     

天津盘山风景名胜区人类干扰对野生动物活动节律影响的初步研究

2019年7月—2020年8月,应用红外相机技术研究天津盘山风景名胜区人类干扰对野生动物活动节律的影响效应,比较分析相对多度指数(RAI)前5位的留鸟和哺乳动物在有、无人类干扰位点区域之间的活动节律差异,以及不同强度人类干扰区域之间的活动节律差异.结果发现:1)人类干扰对留鸟活动节律的影响较小,RAI最大的红嘴蓝鹊Ur...     

四平转山湖水库地区昆虫多样性的初步研究

昆虫个体虽小,但种类繁多,全世界约有140万种生物,而昆虫约占53.57%.昆虫与人类有着极为密切的关系,如害虫对人类健康和国民经济有着重要影响,但绝大多数种类的昆虫对人类是有益或中性的,有的是显花植物的传粉者;有的是害虫的天敌;生活在土壤内的昆虫能促进腐殖质形成与土壤通气,提高土地的肥力;而有些昆虫的产物,如蜂蜜、丝、白蜡等是食品、医药及工业原料;还有许多昆虫用于环境净化和科学研究等多个领域[1].     

Effects of Litter Inputs on N<Subscript>2</Subscript>O Emissions from a Tropical Rainforest in Southwest China

Litter inputs are expected to have a strong impact on soil N₂O efflux. This study aimed to assess the effects of the litter decomposition process and nutrient efflux from litter to soil on soil N₂O efflux in a tropical rainforest. A paired study with a control (L) treatment and a litter-removed (NL) treatment was followed for 2 years, continuously monitoring the effects of these treatments on soil N₂O efflux, fresh litter input, decomposed litter carbon (LCI) and nitrogen (LNI), soil nitrate (NO₃ ^?–N), ammonium (NH₄ ⁺–N), dissolved organic carbon (DOC), and dissolved nitrogen (DN). Soil N₂O flux was 0.48 and 0.32 kg N₂O–N ha^?1 year^?1 for the L and NL treatments, respectively. Removing the litter caused a decrease in the annual soil N₂O emission by 33%. The flux values from the litter layer were higher in the rainy season as compared to the dry season (2.10 ± 0.28 vs. 1.44 ± 0.35 μg N m^?2 h^?1). The N₂O fluxes were significantly correlated with the soil NO₃ ^?–N contents (P < 0.05), indicating that the N₂O emission was derived mainly from denitrification as well as other NO₃ ^? reduction processes. Suitable soil temperature and moisture sustained by rainfall were jointly attributed to the higher soil N₂O fluxes of both treatments in the rainy season. The N₂O fluxes from the L were mainly regulated by LCI, whereas those from the NL were dominated jointly by soil NO₃ ^? content and temperature. The effects of LCI and LNI on the soil N₂O fluxes were the greatest in the 2 months after litter decomposition. Our results show that litter may affect not only the variability in the quantity of N₂O emitted, but also the mechanisms that govern N₂O production. However, further studies are still required to elucidate the impacting mechanisms of litter decomposition on N₂O emission from tropical forests.