Characterizing variations in soil particle size distribution in oasis farmlands-A case study of the Cele Oasis

Characterizing soil particle size distributions (PSD) and their variation is an important issue in environmental research. In this study, fractal theory was used to analyse the soil PSD and its variations in the Cele Oasis, which is located at the southern margin of the Tarim Basin. The characteristics of the soil PSD were then evaluated to identify the primary factors that influence soil PSD. The results showed that the fractal dimension (D) values ranged from 2.11 to 2.27, and that there were significant differences among groups. Furthermore, the D values showed a significant positive correlation with fine particles (<50 mu m) and soil organic matter contents. According to a comparative analysis of D values, the utilization years of farmlands had a significant influence on PSD, while the difference in the spatial distribution of farmlands did not. These results indicated that long-term and effective tillage management of the farmlands will be beneficial to keeping and improving the states of the soil PSD and other soil properties. (C) 2009 Elsevier Ltd. All rights reserved

Ordination as a tool to characterize soil particle size distribution, applied to an elevation gradient at the north slope of the Middle Kunlun Mountains

Soil particle-size distribution (PSD) is one of the most fundamental physical attributes of soil due to its strong influence on other soil properties related to water movement, productivity, and soil erosion. Characterizing variation of PSD in soils is an important issue in environmental research. Using ordination methods to characterize particle size distributions (PSDs) on a small-scale is very limited. In this paper, we selected the Cele River Basin on the north slope of the Middle Kunlun Mountains as a study area and investigated vegetation and soil conditions from 1960 to 4070 m a.s.l. Soil particle-size distributions obtained by laser diffractometry were used as a source data matrix. The Canonical Correspondence Analysis (CCA) ordination was applied to analyse the variation characteristics of PSDs and the relationships between PSDs and environmental factors. Moreover, single fractal dimensions were calculated to support the interpretation of the ordination results. Our results indicate that a differentiation of 16 particle fractions can sufficiently characterize the PSDs in CCA biplots. Elevation has the greatest effect on PSDs: the soil fine fractions increase gradually with increasing elevation. In addition, soil pH, water and total salt content are significantly correlated with PSDs. CCA ordination biplots show that soil and vegetation patterns correspond with one another, indicating a tight link between soil PSDs and plant communities on a small scale in arid regions. The results of fractal dimensions analysis were rather similar to CCA ordination results, but they yielded less detailed information about PSDs. Our study shows that ordination methods can be beneficially used in research into PSDs and, combined with fractal measures, can provide comprehensive information about PSDs. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved

Comprehensive eco-environmental effects of the shelter-forest ecological engineering along the Tarim Desert Highway

In this work, we report a comprehensive study about the eco-environmental effects of the shelter forest along the Tarim Desert Highway, including the effects on aeolian environment, soil, micro-climate, biodiversity, and groundwater. The results show that: (1) The movement of windblown sand near the ground surface was affected by the shelter forest. The wind speed and sediment transport rate in the shelter forest decreased by 64%-80% and 87.45%-99.02%, respectively. In addition, there were also significant changes in the sand flux structure, the sand grain size, and the deflation and deposition on the ground surface. (2) Compared to the natural mobile sand, the soil bulk density in the forest area decreased while the total salt content, the total porosity, and the water content increased. In addition, the soil fertility was significantly improved in the forest area, and showed the "first rapid, then slow" variation pattern. (3) The shelter forest showed positive effects on the micro-climate. Within the 6 m height above the ground, the air temperature in the shelter forest at different heights was lower than that in the mobile sand, while the air humidity was higher, while, the soil temperature was also lower in the shelter forest than mobile sand. (4) The number of soil microbial species increased significantly with the improvement of habitat in the shelterbelt. However, the population of different species was not distributed evenly across the surveyed area. (5) Currently, no significant effects of groundwater-pumping and forest-irrigation water have been found on the groundwater level and its salinity. The variation amplitude of both groundwater level and salinity was at the level of centimeters and 1g/L, respectively. No obvious variation trend has been observed

Epidemiology of Angiostrongylus cantonensis and eosinophilic meningitis in the People's Republic of China

Background: Human eosinophilic meningitis is mainly caused by the rat lungworm Angiostrongylus cantonensis, especially in tropical and subtropical regions. Since the mid-1940s, more than 2800 cases of eosinophilic meningitis have been reported in at least 30 countries. Of note, A. cantonensis is one of a few helminths that can cause an outbreak within a short time period (usually within 2 weeks). Fatal cases, particular among young children, have been reported in heavily infected subjects. Eosinophilic meningitis is paradoxically an emerging infectious disease in the People¡¯s Republic of China (P.R. China). Indeed, while the rat lungworm was discovered in Guangzhou (formerly Canton) in 1933, there were only few cases reported until the mid 1990s. However, the biological invasion of two exotic snail species, namely the African land snail Achatina fulica and the South American freshwater snail Pomacea spp., drove the emergence of this disease. Thus far, more than three-quarter of human cases could definitely be related to the consumption of these snail species, particularly Pomacea spp. The seven outbreaks that occurred between 1997 and 2006 in P.R. China were all attributed to these two invasive snail species. Due to the emergence of eosinophilic meningitis and the issue of outbreaks that occurred at a growing frequency in P.R. China, there as a felt need to deepen our understanding of the epidemiology and control of this disease. Although several small-scale surveys pertaining to A. cantonensis had been carried out in P.R. China, the exact distribution of the parasite, and the invasive snail species that act as intermediate hosts remained to be determined. Goal and objectives: The overarching goal of this thesis is to improve our knowledge on the epidemiology of A. cantonensis and eosinophilic meningitis in P.R. China. There are six specific and interlinked objectives: (i) to identify the control priorities in eosinophilic meningitis by observing and analyzing outbreaks; (ii) to reveal the geographical distribution of A. cantonensis and to identify the major intermediate hosts; (iii) to characterize the mitochondrial (mt) genome of A. cantonensis and its close relative A. costaricensis in order to identify genetic marker that might give rise to novel diagnostic assays and population genetic studies; (iv) to evaluate the intraspecific differentiation of A. cantonensis and explore the potential dynamic scenarios in P.R. China; (v), to assess the genetic diversity of the invasive snail species Pomacea spp. and explore potential spread scenarios; and (vi) to assess the interplay between invasive snails, climate change and transmission dynamics. Methodology and principal findings: In 2008, we had the opportunity to study an outbreak of angiostrongyliasis that occurred in Dali due to the consumption of Pomacea spp. We found a prolonged period (8 months) of this outbreak with the peak occurring in February 2008, owing to a traditional festival. Only 11 out of 33 patients with complete data records were categorized into clinically diagnosed cases, whereas the others were grouped into suspected cases according to the existing diagnosis criteria. None of the patients was parasitologically diagnosed. Some important information for diagnosis was missing, which reflected the ignorance of clinicians on this disease. The existing diagnosis criteria for clinically diagnosed case requested an elevated eosinophil count both in peripheral blood and in cerebrospinal fluid (CSF), which was rather restrict. Interestingly, not all patients simultaneously experienced a marked change in eosinophil count, both in peripheral blood and CSF. Our findings called for further standardization of diagnosis and generalization of the clinical criteria. Surveillance system in endemic areas should be established for both security of snail food and human cases in hospitals. We had access to data obtained from the first national survey pertaining to A. cantonensis which was implemented using a geographical grid sampling approach. Our results showed that the rat lungworm was endemic in 59 of the 164 surveyed counties (36.0%), which represented seven south provinces in the mainland of P.R. China. Two of these provinces were newly confirmed. Two invasive snail species were identified as the key intermediate hosts. On average, the prevalence of A. cantonensis among A. fulica and Pomacea spp. was 13.4% and 6.8%, respectively. The prevalence among other terrestrial mollusks range from 0.3% (snail) to 6.5% (slugs), while that among freshwater snails was only 0.05%. Pomacea snails were found in 11 provinces, whereas A. fulica was encountered in six provinces. The complete mt genomes of A. cantonensis and A. costaricensis are 13,497 bp and 13,585 bp in length, respectively. Hence, these two closely related nematodes have the smallest mt genomes in the class of Chromadorea characterized thus far. Overall nucleotide identity of these two mt genomes was 81.6%, with a range from 77.7% to 87.1% in individual gene pairs. These findings provide a sound basis for screening potential genetic markers for diagnosis and further in-depth population genetic studies. The mt genome-wide analysis identified three major gene arrangement patterns from 48 nematode mt genomes. The gene arrangement, coupled with a phylogenetic tree based on concatenated amino acid sequence, supported a closer relationship between Ascaridida and Strongylida rather than Spirurida, which is inconsistent with findings of previous studies according to the nuclear small ribosomal subunit DNA. A. cantonensis specimens obtained from 33 collection sites were used to study the intraspecific differentiation based on the mitochondrial nad1 gene. A total of 73 haplotypes of A. cantonensis were identified from 143 sequences, which resulted in seven distinctive clades (Mainland, Hainan, Sanya, Tiane, Nanao, Zixing and Thailand). Geographical distance and natural isolation played a role in the spatial distribution of these clades, which supported the Southeast Asian origin from a molecular point of view. A considerable haplotype invasion was noted, which indicated the impact of human activities on biodiversity. The potential invasion routes for the clades Hainan, Sanya and Tiane were inferred based on a network analysis. The conflict between the presumptive origin of the clades Hainan and Tiane and those of the clades Nanao and Sanya call for further research. A total of 523 sequences of mt gene cox1 of Pomacea spp. were obtained from 56 collection sites. Twenty-five haplotypes were identified with an overall diversity of 0.702, which was higher than those observed in previous studies. From a global point of view, only five out of 98 haplotypes, which were determined by the currently 228 available sequences in GenBank as well as the 523 sequences described in the present thesis, were shared between introduced (Southeast Asia) and native (South America) ranges. The 98 haplotypes were clustered into 10 groups. Six groups occurred in the mainland of P.R. China, among only two can be traced back to the South Americas, whereas were two also occurred in other countries in Southeast Asia. The remaining two groups only occurred in P.R. China. A phylogenetic analysis showed that two species (i.e. P. canaliculata and P. insularum) coexist in the mainland of P.R. China, although the phylogenetic position of group B is still pending. The definite spread route of this snail species was not determined, but the increased diversity in single collection sites indicated multiple and secondary introductions. Finally, we developed a biology-driven model to determined potential impacts of climate change on the distribution of Pomacea spp., and hence the transmission of A. cantonensis. Mean January temperature and snail generation intensity (generation number) were identified as key factors determining the distribution of Pomacea spp.. The model predicted an increase of 56.9% for the ¡®spread¡¯ and a decrease of 40.9% for the ¡®establishment¡¯ regions (¡®spread¡¯ and ¡®establishment¡¯ defined according to the aforementioned national sampling survey) by the 2030s relative to the present day. Key determinants of A. cantonensis transmission were identified as the generation intensity in the intermediate host, the longevity of A. cantonensis-infected rats and the dormant period of Pomacea spp. Importantly, transmission of A. cantonensis occurs only in areas where the snail¡¯s dormant period is below 173.2 days. The potential endemic area of A. cantonensis was predicted to double by the 2030s relative to the present day. Conclusions/significance: Outbreaks of eosinophilic meningitis are of particular and growing concern in P.R. China. Standardization and generalization of diagnosis and treatment are therefore urgently required to be better equipped for future outbreaks. The first national survey deepened our understanding of the distribution of A. cantonensis and two invasive snail species that have been identified as the key intermediate hosts. Our in-depth population genetic studies of A. cantonensis revealed that human activities changed the original distribution and might have facilitated long-distance dispersal. The well divergent clades implied that the mt genes are promising candidates for novel diagnostic markers and population genetic studies. Our research also showed that two species of Pomacea coexist in P.R. China. The current distribution indicated multiple and secondary introductions. Although the definite role of these snail in the current distribution pattern of A. cantonensis is not clear, the potential impact is considerable in a future warmer P.R. China

Advances in Plant Breeding Strategies : Nut and Beverage Crops

Peer reviewe

Meclatis in Clematis: yellow flowering Clematis species : systematic studies in Clematis L. (Ranunculaceae), inclusive of cultonomic aspects

The general classification of the genus Clematis (Ranunculaceae) was subject of study in chapter 1. Based on species character scores, the infrageneric classification was analyzed by applying Hennig86 as phylogenetical analysis package. As result of this analysis Clematis was subdivided into 18 sections, one of them subdivided in 3 subsections.The world distribution of Clematis was also studied with Hennig86. It was not possible to postulate the area of origin of the genus Clematis with the available data set.A interspecific cross polygon was made and analyzed by seed set and pollen tube growth. Its systematic significance with regard to Clematis and in general was discussed. Dependent on the adopted species concept, these crosses are crucial or just academic. The adoption of the phylogenetic species concept made that this choice for Clematis is academic. Nevertheless, it is useful information for plant breeders.A general description of the genus Clematis was presented with some background information on certain characters, such as overall habitus, nectar leaves and the position of nectaries.Chapter 2 was devoted to Clematis sect. Meclatis . This particular section consists of the yellow-flowering Clematis spp., that are gaining popularity in gardening. Many efforts were directed to reveal the species delimitation. It appeared that the phenetic methodology is of restricted value in such a complex of quite similar species. Using a combination of methods, the phylogenetic analysis by Hennig86 finally revealed the species delimitation: Clematis orientalis , C. graveolens , C. intricata , C. ispahanica , and C. tibetana . C. tibetana was subdivided into three subspecies: subsp. tibetana , subsp. tangutica and subsp. vernayi . Well-known 'horticultural species' such as C. tangutica and C. vernayi were reduced in rank and others such as C. glauca and C. akebioides were reduced to synonymy. A summary of chromosome, pollen and isozyme data was presented.Chapter 3 was focusing on more fundamental aspects of systematics of cultivated plants. It has been shown that the cultivar group is of crucial importance in classifying cultivars, that the classification principle for cultivated plants is open instead of closed and consequently that the basal term in systematics of cultivated plants for an entity cannot be taxon, but should be a new term culton (plur. culta; cultonomy for culta vs. taxonomy for taxa).Clematis is one of the first genera for which a cultivar group classification was presented in a systematic way, as was outlined in chapter 4. A short survey was given of the introduction into cultivation of yellow-flowering Clematis spp., and a major part of the yellow-flowering Clematis cultivar assortment has been described. So far no cultivar groups are needed for these cultivars.</p

Plant Extracts

Society has recently demonstrated a high level of awareness and responsibility concerning environmental issues. The interest in bioactive compounds extracted from natural sources has increased due to their potential application as active ingredients in several industries, particularly the cosmetic, food, and pharmaceutical industries. Plants are rich sources of phenolic compounds that have been widely studied due to their health-promoting properties, namely antioxidant, anti-carcinogenic, and anti-inflammatory activities, among others. Extraction is usually the limiting analytical step in the yield of bioactive compounds. From a green point of view, many extraction techniques have been employed as potential candidates to replace conventional methods, such as ultrasound-assisted extraction (UAE), pressurized liquid extraction (PLE), microwave-assisted extraction (MAE), supercritical fluid extraction (SFE), pulsed electric field extraction, and enzyme-assisted extraction. In this Special Issue, we focus our attention on the chemical characterization of plant extracts and their bioactive composition, focusing also on in-vitro cell assays and molecular tools. The issue comprises original research articles, as well as a review, on topics such as phenolic profile, radical scavenging capacity, in vitro cell assays, comet assay, and antimicrobial capacity. We close this Special Issue with a review paper that focuses on the pharmacological activities of quercetin, one of the principal polyphenols. With this, we aim to provide a contemporary overview of the advantages of bioactive compounds extracted from plants

Urban Informatics

This open access book is the first to systematically introduce the principles of urban informatics and its application to every aspect of the city that involves its functioning, control, management, and future planning. It introduces new models and tools being developed to understand and implement these technologies that enable cities to function more efficiently – to become ‘smart’ and ‘sustainable’. The smart city has quickly emerged as computers have become ever smaller to the point where they can be embedded into the very fabric of the city, as well as being central to new ways in which the population can communicate and act. When cities are wired in this way, they have the potential to become sentient and responsive, generating massive streams of ‘big’ data in real time as well as providing immense opportunities for extracting new forms of urban data through crowdsourcing. This book offers a comprehensive review of the methods that form the core of urban informatics from various kinds of urban remote sensing to new approaches to machine learning and statistical modelling. It provides a detailed technical introduction to the wide array of tools information scientists need to develop the key urban analytics that are fundamental to learning about the smart city, and it outlines ways in which these tools can be used to inform design and policy so that cities can become more efficient with a greater concern for environment and equity

Plant Growth Promoting Actinobacteria : A New Avenue for Enhancing the Productivity and Soil Fertility of Grain Legumes

Global yields of legumes have been relatively stagnant for the last five decades, despite the adoption of conventional and molecular breeding approaches. The use of plant growth-promoting (PGP) bacteria for improving agricultural production, soil and plant health has become one of the most attractive strategies for developing sustainable agriculture. Actinomycetes are bacteria that play an important role in PGP and plant protection, produce secondary metabolites of commercial interest, and their use is well documented in wheat, rice, beans, chickpeas and peas. In order to promote legumes, the general assembly of the UN recently declared 2016 the “International Year of Pulses.” In view of this development, this book illustrates how PGP actinomycetes can improve grain yield and soil fertility, improve control of insect pests and phytopathogens, and enhance host-plant resistance. It also addresses special topics of current interest, e.g. the role of PGP actinomycetes in the biofortification of legume seeds and bioremediation of heavy metals