Applications of chitosan in food,pharmaceuticals, medicine,cosmetics, agriculture,textiles, pulp and paper,biotechnology, and environmental chemistry

Environmental Chemistry Letters - Chitosan is a biopolymer obtained from chitin, one of the most abundant and renewable materials on Earth. Chitin is a primary component of cell walls in fungi, the...     

六六六热解废渣中2,3,7,8—取代PCDDs和PCDFs的测定

采用ＨＰＬＣ和ＧＣ／ＭＳ法对六六六热解废渣中的ＰＣＤＤｓ和ＰＣＤＦｓ进行了测定，使用此种方法，于废渣中检出了所有２，３，７，８－取代的同系物。此外，还根据各ＣＤＤｓ，ＣＤＦｓ的毒性当量因子ＴＥＦｓ，计算了废渣的毒性当量ＴＥＱｓ，约为６１２－９２４μｇ／ｇ。分析表明，ＯＣＤＤ是含量最丰富的导构体，而１，２，３，４，６，７，８－ＨｐＣＤＤ，１，２，３，４，６，７，８－ＨｐＣＤＦ和１，２，３，４，７，８     

Mammal Diversity and Conservation in the Selva Lacandona, Chiapas, Mexico

The Selva Lacandona region of Chiapas, Mexico, has high biodiversity, represents the last large portion of tropical rainforest in México, and faces imminent destruction. Through fieldwork and literature searches I found a total of 112 mammal species (including 17 Middle-American endemics) on the Lacandona's 331,200 ha Montes Azules Biosphere Reserve. This inventory plus those from eight additional Neotropical localities show local mammal species richness in the Neotropics to be in the range of 70–116 species. Richness is primarily correlated with the amount of annual rainfall, but within rainforest areas species richness is probably not correlated with rainfall, latitude, altitude, or area size. Rather, above a certain limit of rainfall and below a critical level of latitude and altitude, mammal species richness seem to reach an asymptotic maximum. Areas covered with tropical rainforest and with a well-known, relatively intact fauna have about 112–116 mammal species. In the Montes Azules Reserve most mammals (57%) are bats. The most heavily occupied feeding guilds are frugivores/herbivores and insectivores/omnivores. Large species and carnivores appear most vulnerable to local extinction. Montes Azules (and thus the Selva Lacandona) is especially noteworthy because (1) it contains a greater proportion of species facing conservation problems than expected from a random draw of Mexican mammals; (2) it is probably the most diverse ecosystem in Mexico; (3) many species sustain their only Mexican populations in this area; and (4) it is the largest remnant of tropical rainforest in Mexico and is part of the largest expanse of that vegetation type in Central America.     

Hydrogen production from wastewater,storage, economy,governance and applications: a review

Environmental Chemistry Letters - In the context of climate change, most of the actual dihydrogen production is not sustainable with about 96% of the 60 million tons of dihydrogen produced annually...     

Are breaking waves,bores, surges and jumps the same flow?

The flow structure in the aerated region of the roller generated by breaking waves remains a great challenge to study, with large quantities of entrained air and turbulence interactions making it very difficult to investigate in details. A number of analogies were proposed between breaking waves in deep or shallow water, tidal bores and hydraulic jumps. Many numerical models used to simulate waves in the surf zone do not implicitly simulate the breaking process of the waves, but are required to parameterise the wave-breaking effects, thus relying on experimental data. Analogies are also assumed to quantify the roller dynamics and the energy dissipation. The scope of this paper is to review the different analogies proposed in the literature and to discuss current practices. A thorough survey is offered and a discussion is developed an aimed at improving the use of possible breaking proxies. The most recent data are revisited and scrutinised for the use of most advanced numerical models to educe the surf zone hydrodynamics. In particular, the roller dynamics and geometrical characteristics are discussed. An open discussion is proposed to explore the actual practices and propose perspectives based on the most appropriate analogy, namely the tidal bore.     

Assessing the potential ecological risk of Co,Cr, Cu,Fe and Zn in the sediments of Hooghly–Matla estuarine system,India

Environmental Geochemistry and Health - Hooghly–Matla estuarine system along with the Sundarbans mangroves forms one of the most diverse and vulnerable ecosystems in the world. We have...     

Sea otters,social justice,and ecosystem‐service perceptions in Clayoquot Sound,Canada

We sought to take a first step toward better integration of social concerns into empirical ecosystem service (ES) work. We did this by adapting cognitive anthropological techniques to study the Clayoquot Sound social‐ecological system on the Pacific coast of Canada's Vancouver Island. We used freelisting and ranking exercises to elicit how locals perceive ESs and to determine locals’ preferred food species. We analyzed these data with the freelist‐analysis software package ANTHROPAC. We considered the results in light of an ongoing trophic cascade caused by the government reintroduction of sea otters (Enhydra lutris) and their spread along the island's Pacific coast. We interviewed 67 local residents (n = 29 females, n = 38 males; n = 26 self‐identified First Nation individuals, and n = 41 non‐First Nation individuals) and 4 government managers responsible for conservation policy in the region. We found that the mental categories participants—including trained ecologists—used to think about ESs, did not match the standard academic ES typology. With reference to the latest ecological model projections for the region, we found that First Nations individuals and women were most likely to perceive the most immediate ES losses from the trophic cascade, with the most certainty. The inverse was found for men and non‐First Nations individuals, generally. This suggests that 2 historically disadvantaged groups (i.e., First Nations and women) are poised to experience the immediate impacts of the government‐initiated trophic cascade as yet another social injustice in a long line of perceived inequities. Left unaddressed, this could complicate efforts at multistakeholder ecosystem management in the region.     

云南临沧地区公路两侧紫茎泽兰分布格局

云南省临沧地区是我国紫茎泽兰(Eupatorium adenophorum)传入最早和入侵危害最严重的地区。文章在该地区选取典型路段并设置了10个样地,以等级、路宽、路面状况、路龄、人类活动干扰不同的7条公路为研究对象,分析了紫茎泽兰生物量、株高和株数与距公路距离、公路宽度、景观类型、坡向及海拔的关系。结果表明,公路对紫茎泽兰生物量和株高有显著影响的最远距离为24m,而对株数的影响达34m;6m宽的公路对紫茎泽兰生物量和株数影响最显著,且路龄越长、交通干扰越大的公路两侧的紫茎泽兰入侵危害越严重;紫茎泽兰在公路附近的撂荒地和次生林两个景观类型中入侵危害严重,景观类型对生物量与坡向对株高的影响不显著,位于南坡公路附近的紫茎泽兰生物量和株数最高,研究发现公路附近紫茎泽兰总生物量随海拔升高而增加,在1700m达最大,随后则降低。     

粤港澳地区多环芳烃的多介质归趋

以广东省及港澳两地为研究区域,在完全混合和稳态假设下采用多介质逸度模型估算了目前状况下16种优控多环芳烃(PAH16)在环境各相中的质量浓度及跨界面迁移通量,并采用实测质量浓度数据进行模型验证。除个别数据外,预测质量浓度与验证质量浓度的差别在一个数量级以下,且多数在半个量级之内。模型计算结果表明:化石燃料燃烧是当地PAH16的主要来源,大气和土壤中的降解是其消失的主要途径,PAH16在该地区的最重要界面迁移过程是气地(水)交换。     

Fractionation of trace metals (Mn,Zn, Cu,Pb) in Red Sea sediments,Gulf of Aden,Yemen

A sequential extraction technique was applied to estimate the chemical association of Mn, Zn, Cu and Pb in five chemical phases (exchangeable, carbonate, Fe–Mn oxides, organic matter and residual) in sediments of the Gulf of Aden, Yemen. The results indicated that a higher level of Mn was associated with the residual fraction (natural sources) than the non-residual fraction (anthropogenic sources). Zn fractionations revealed that it was associated more with Fe–Mn oxides and organic fractions than exchangeable and carbonate fractions. Most of the Cu was present in the residual form (60–72%) except for in the main port area (zone III), where it was associated with the organic phase (77% of the total Cu content, the organic matter content was 5%). Similarly, most Pb was bound in the residual fraction (56–71%) except the main port area where ～ 62% of the total Pb was bound in non-residual fractions. It was also found that the Pb concentration in the exchangeable fraction was very high compared with other metals. The risk assessment code for the metals showed a low risk for Zn and Cu, but low to medium risk for Mn. Fractionation of Pb showed medium risk at most of the regions except at the eastern area, which revealed a high risk for the aquatic environment.     

Breed Structures of for Conservation of Middle Rare Pigs: Implications the Berkshire, Tamworth, White, Large Black, Gloucester Old Spot, British Saddleback, and British Lop

Abstract: Registration details of seven rare British breeds of pig w e studied over the period 1978–1986 inclusive. For four breeds, numbers of pigs registered have shown a slight upward trend. About 70% of males and 40% of females that breed, do so in herds other than the natal herd In the breed for which most pedigree data were analysed (the British Lop), 95–100% of recent pig crops were inbred In the rare breeds generally, mean inbreeding at around 6% signifies an inbreeding rate of about 1 % per generation, higher than has been found in commercial breeds. Breeds did not differ greatly in the ways they were structured.
About a third of herds supplied boars to other herds, a relatively high proportion, indicating that the breeds have a structure that is not completely hierarchical, and this is favorable for genetic conservation. Pigs whose parents were from different herds were significantly less inbred than those with both parents from the same herd In some breeds it was clear that pigs sharing the same bloodline name were more closely related than pigs within the same herd but with different bloodline names.
Conservation procedures applied to these pigs have been designed to conform with the customs and procedures of the British pedigree livestock industry. The most important single such procedure is the registration, with a central authority, of breeding stock.     

Aspects of the community ecology of deep-sea,benthopelagic plankton,with special attention to gymnopleid copepods

Benthopelagic plankton was collected 10 to 100 m above the bottom of the deep sea (1100 to 3200 m) with an opening-closing net. Five samples were taken from the San Diego Trough, 2 from the eastern tropical Pacific and 2 from the northeast Atlantic. Roughly 80% of the individual organisms collected were copepods; the next most abundant groups were usually isopods, ostracods, and chaetognaths. Within the depth range studied, absolute abundances of most animal groups decreased with depth, but relative abundances (%) did not change. Of over 100 species of adult gymnopleid copepods collected, a few species were abundant, but most were rare. Copepod exoskeletons were more abundant than living copepods. For the gymnopleids, similarities among the 3 geographical regions were strong at the family and genus level but weak at the species level. Species that were widely distributed horizontally tended to occupy different positions (in terms of rank order of abundance) in each community. Gut content analysis indicated that the most abundant gymnopleids were generalized particle feeders. However, size-frequency distributions provided indirect evidence for niche separation. The deep-sea benthopelagic plankton was divisible into a truly planktonic component and a bottom-associated component. Abundances of some copepods changed relative to distance off the bottom. Several copepods and other animals, previously described as epibenthic or bottom-associated, were collected more that 10 m above the bottom and thus appeared to move freely between the bottom and lower water column.     

Unexpected behavior of Zn,Cd, Cu,and Pb in soils contaminated by ore processing after 70 years of burial

Environmental Chemistry Letters - Heavy metals in contaminated ore processing areas present a risk of contamination of waters and life. Therefore, the most mobile fractions of metals, which can be...     

Mating system,optimal number of matings,and sperm transfer in the Argentine ant Iridomyrmex humilis

Summary In ants, because males have a finite sperm supply and females mate only at the beginning of their reproductive lives, it is possible to infer which is the limiting sex from a few parameters: the amount of sperm produced by males, the amount of sperm stored by females, and the numerical sex ratio. In the Argentine ant Iridomyrmex humilis mating takes place in the nest. Laboratory experiments and field data showed that the numerical sex ratio is heavily male-biased (10.1:1) and that the maximum number of sperm a female can store is similar to the number of sperm a male possesses. Thus females are the limiting sex in this species. In a set of mating experiments, one queen was presented with 1–20 males. The highest proportion of successful matings occurred when females were presented with two males. There was a significant negative correlation between the amount of sperm queens stored and the number of males present in the mating arena. This relationship most likely resulted from male interference during the copulation process. When several males were present in the arena, the mating pair was frequently disturbed by other males trying to copulate. Newly mated queens collected from the field stored 172,000 ± 76,000 sperm, a quantity most similar to that measured in laboratory mating experiments with a ratio of 5 or 10 males per queen. Because the operational sex ratio in I. humilis is highly male-biased, male interference may also decrease the amount of sperm queens store in the field. In many ants, fewer sperm stored by queens should decrease their reproductive success because they would run out of sperm earlier in their reproductive lifetimes. However, comparison of the amount of sperm present in young and old I. humilis queens collected in the field suggests that most use only a small proportion of their sperm supply during their lifetimes. Males mate once and discharge all their sperm during a single mating. Females may mate with several males but dissection of these males indicated that in most cases only one of them had empty seminal vesicles thus suggesting that a single male is responsible for most of the sperm transfer. Thus caution should be exercised in inferring multiple inseminations, as is frequently done in eusocial insects, from the observation of multiple copulations. Correspondence to: L. Keller     

Perception,knowledge and attitude towards environmental issues and management among residents of Al-Suwaiq Wilayat,Sultanate of Oman

The purpose of this study was to determine residents’ perception, knowledge and attitude towards environmental issues and management in the Al-Suwaiq Wilayat (administrative zone) of Al-Batinah North, Sultanate of Oman. For this purpose, a questionnaire was used with questions on issues related to environment and surveyed across 109 households in the Wilayat following a random sampling method in early 2015. The results show that education, health-related infrastructure and unemployment are ranked as most important issues for government attention today and in coming 10 years besides their concern for the environment. Resident’s perceptions on most important environmental issues were concerned about solid-waste pollution, degradation of coastal areas, saltwater intrusion and land degradation. The sources for environmental information, government agencies, local media and schools were regarded as most reliable. Top environmental priorities were suggested to deal with enforcement of regulations, provide effective environmental awareness and education programs. Further, it is suggested that additional studies should be conducted such as ‘State of Environment Reporting’, thereby such reporting, for instance would provide some form of verification of reported behaviour and improved knowledge.     

喜旱莲子草在中国的入侵机理及其生物防治

喜旱莲子草为全球性恶性杂草,也是中国生物多样性国家报告中首批9种重要外来入侵植物之一.本文综述了喜旱莲子草的起源、分布以及在我国的传播扩散和危害,并分析了入侵机制.鉴于这是我国生物防治外来杂草最成功的项目,还介绍了利用昆虫天敌生物防治的过程、实践和经验,讨论了存在的问题及应对策略. 参60     

Hydrogen sulfide, bacteria, and fish: a unique, subterranean food chain

Photoautotrophs are generally considered to be the base of food webs, and habitats that lack light, such as caves, frequently rely on surface-derived carbon. Here we show, based on analysis of gut contents and stable isotope ratios of tissues (13C:12C and 15N:14N), that sulfur-oxidizing bacteria are directly consumed and assimilated by the fish Poecilia mexicana in a sulfide-rich cave stream in Tabasco state, Mexico. Our results provide evidence of a vertebrate deriving most of its organic carbon and nitrogen from in situ chemoautotrophic production, and reveals the importance of alternative energy production sources supporting animals in extreme environments.     

Understanding Trait‐Dependent Community Disassembly: Dung Beetles,Density Functions,and Forest Fragmentation

Abstract: Anthropogenic disturbances such as fragmentation are rapidly altering biodiversity, yet a lack of attention to species traits and abundance patterns has made the results of most studies difficult to generalize. We determined traits of extinction‐prone species and present a novel strategy for classifying species according to their population‐level response to a gradient of disturbance intensity. We examined the effects of forest fragmentation on dung beetle communities in an archipelago of 33 islands recently created by flooding in Venezuela. Species richness, density, and biomass all declined sharply with decreasing island area and increasing island isolation. Species richness was highly nested, indicating that local extinctions occurred nonrandomly. The most sensitive dung beetle species appeared to require at least 85 ha of forest, more than many large vertebrates. Extinction‐prone species were either large‐bodied, forest specialists, or uncommon. These explanatory variables were unrelated, suggesting at least 3 underlying causes of extirpation. Large species showed high wing loading (body mass/wing area) and a distinct flight strategy that may increase their area requirements. Although forest specificity made most species sensitive to fragmentation, a few persistent habitat generalists dispersed across the matrix. Density functions classified species into 4 response groups on the basis of their change in density with decreasing species richness. Sensitive and persistent species both declined with increasing fragmentation intensity, but persistent species occurred on more islands, which may be due to their higher baseline densities. Compensatory species increased in abundance following the initial loss of sensitive species, but rapidly declined with increasing fragmentation. Supertramp species (widespread habitat generalists) may be poor competitors but strong dispersers; their abundance peaked following the decline of the other 3 groups. Nevertheless, even the least sensitive species were extirpated or rare on the smallest and most isolated islands.     

Contamination and source assessment of metals,polychlorinated biphenyls,and polycyclic aromatic hydrocarbons in urban soils from Addis Ababa,Ethiopia

Urban areas in developing countries are facing vast environmental problems as a result of rapid urbanization and industrialization. Of major concern is the contamination of soils which are increasingly becoming sinks for environmental pollutants. However, to date only little is known about the pollution in the megalopolises of developing countries. The aim of this study was to assess the contamination and potential sources of metals, polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) in the urban environment of Addis Ababa, the capital of Ethiopia. The investigation revealed the presence of most of the analyzed pollutants in soil and sediment samples with total concentrations (dry wt) of PAHs ranging from 186 to 3150?µg?kg^?1, PCBs from 0.4 to 19?µg?kg^?1, Cu from 14 to 173?mg?kg^?1, Zn from 36 to 440?mg?kg^?1, Pb from 9 to 700?mg?kg^?1, and Ni from 16 to 72?mg?kg^?1. In addition, polyaromatic sulfur heterocycles, typical for oil and petrol residues, were detected in several soil samples. Source identification approaches revealed that Pb, Zn, and Cu are most likely derived from pyrolytic sources, with elevated values in samples related to waste combustion and traffic emissions. Ni is most probably of geogenic origin. For PCBs it is indicated that they are derived from a single source. However, correlations with technical PCB mixtures were inconsistent. PAHs originate from the combustion of biomass, vehicular exhausts, and petrogenic sources.     

Hunting, law enforcement, and African primate conservation

Abstract: Primates are regularly hunted for bushmeat in tropical forests, and systematic ecological monitoring can help determine the effect hunting has on these and other hunted species. Monitoring can also be used to inform law enforcement and managers of where hunting is concentrated. We evaluated the effects of law enforcement informed by monitoring data on density and spatial distribution of 8 monkey species in Taï National Park, Côte d’Ivoire. We conducted intensive surveys of monkeys and looked for signs of human activity throughout the park. We also gathered information on the activities of law‐enforcement personnel related to hunting and evaluated the relative effects of hunting, forest cover and proximity to rivers, and conservation effort on primate distribution and density. The effects of hunting on monkeys varied among species. Red colobus monkeys (Procolobus badius) were most affected and Campbell's monkeys (Cercopithecus campbelli) were least affected by hunting. Density of monkeys irrespective of species was up to 100 times higher near a research station and tourism site in the southwestern section of the park, where there is little hunting, than in the southeastern part of the park. The results of our monitoring guided law‐enforcement patrols toward zones with the most hunting activity. Such systematic coordination of ecological monitoring and law enforcement may be applicable at other sites.