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1.
Leccinum scabrum sporocarps and associated topsoils from two areas in Poland have been characterized for contents and bioconcentration potential of Ag, Al, Ba, Ca, Cd, Co, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, P, Pb, Rb, Sr and Zn. Topsoil and fruitbody element composition varied between the two study sites, most likely as a result of local soil geochemistry. Element content of the labile fraction in topsoil from both sites followed the ‘pseudo‐total’ fraction and median values (mg kg?1 dry matter) were: K 380 and 340, Mg 760 and 840, P 1100 and 920, Al 3800 and 8100, Ag 0.31 and 0.28, Ba 28 and 37, Ca 920 and 790, Cd 0.23 and 0.23, Co 2.0 and 1.7, Cu 3.2 and 3.6, Fe 2800 and 6300, Mn 280 and 180, Na 99 and 110, Ni 7.8 and 8.8, Pb 12 and 18, Rb 1.3 and 2.1, Sr 4.8 and 4.0 and Zn 22 and 19, respectively. Only for some elements such as K, Mg, Al, Ag, Ca, Co, Mn, Na, Ni, Sr and Zn we found concentration differences between the two study sites for the caps of sporocarps. With the exception of Al, Mn, Na and Pb, stipes showed a similar tendency. Caps had a higher concentration of K, Rb, P, Mg, Al, Ag, Cu, Fe, Zn, Cd, Pb and Ni compared to stipes, while Na, Ba and Sr contents were higher in stipes. The comparison of soil and fruitbody concentrations indicates that L. scabrum bioconcentrate some elements while others are bioexcluded.  相似文献   

2.
The Hierarchical Taxonomy of Psychopathology (HiTOP) is a scientific effort to address shortcomings of traditional mental disorder diagnoses, which suffer from arbitrary boundaries between psychopathology and normality, frequent disorder co‐occurrence, heterogeneity within disorders, and diagnostic instability. This paper synthesizes evidence on the validity and utility of the thought disorder and detachment spectra of HiTOP. These spectra are composed of symptoms and maladaptive traits currently subsumed within schizophrenia, other psychotic disorders, and schizotypal, paranoid and schizoid personality disorders. Thought disorder ranges from normal reality testing, to maladaptive trait psychoticism, to hallucinations and delusions. Detachment ranges from introversion, to maladaptive detachment, to blunted affect and avolition. Extensive evidence supports the validity of thought disorder and detachment spectra, as each spectrum reflects common genetics, environmental risk factors, childhood antecedents, cognitive abnormalities, neural alterations, biomarkers, and treatment response. Some of these characteristics are specific to one spectrum and others are shared, suggesting the existence of an overarching psychosis superspectrum. Further research is needed to extend this model, such as clarifying whether mania and dissociation belong to thought disorder, and explicating processes that drive development of the spectra and their subdimensions. Compared to traditional diagnoses, the thought disorder and detachment spectra demonstrated substantially improved utility: greater reliability, larger explanatory and predictive power, and higher acceptability to clinicians. Validated measures are available to implement the system in practice. The more informative, reliable and valid characterization of psychosis‐related psychopathology offered by HiTOP can make diagnosis more useful for research and clinical care.  相似文献   

3.
Polyamines are fundamental molecules of life, and their deep evolutionary history is reflected in extensive biosynthetic diversification. The polyamines putrescine, agmatine, and cadaverine are produced by pyridoxal 5′-phosphate-dependent L-ornithine, L-arginine, and L-lysine decarboxylases (ODC, ADC, LDC), respectively, from both the alanine racemase (AR) and aspartate aminotransferase (AAT) folds. Two homologous forms of AAT-fold decarboxylase are present in bacteria: an ancestral form and a derived, acid-inducible extended form containing an N-terminal fusion to the receiver-like domain of a bacterial response regulator. Only ADC was known from the ancestral form and limited to the Firmicutes phylum, whereas extended forms of ADC, ODC, and LDC are present in Proteobacteria and Firmicutes. Here, we report the discovery of ancestral form ODC, LDC, and bifunctional O/LDC and extend the phylogenetic diversity of functionally characterized ancestral ADC, ODC, and LDC to include phyla Fusobacteria, Caldiserica, Nitrospirae, and Euryarchaeota. Using purified recombinant enzymes, we show that these ancestral forms have a nascent ability to decarboxylate kinetically less preferred amino acid substrates with low efficiency, and that product inhibition primarily affects preferred substrates. We also note a correlation between the presence of ancestral ODC and ornithine/arginine auxotrophy and link this with a known symbiotic dependence on exogenous ornithine produced by species using the arginine deiminase system. Finally, we show that ADC, ODC, and LDC activities emerged independently, in parallel, in the homologous AAT-fold ancestral and extended forms. The emergence of the same ODC, ADC, and LDC activities in the nonhomologous AR-fold suggests that polyamine biosynthesis may be inevitable.  相似文献   

4.
Tentacles are remarkable anatomical structures in invertebrates for their diversity of form and function. In bivalves, tentacular organs are commonly associated with protective, secretory, and sensory roles. However, anatomical details are available for only a few species, rendering the diversity and evolution of bivalve tentacles still obscure. In Pteriomorphia, a clade including oysters, scallops, pearl oysters, and relatives, tentacles are abundant and diverse. We investigated tentacle anatomy in the group to understand variation, infer functions, and investigate patterns in tentacle diversity. Six species from four pteriomorphian families (Ostreidae, Pinnidae, Pteriidae, and Spondylidae) were collected and thoroughly investigated with integrative microscopy techniques, including histology, scanning electron microscopy, and confocal microscopy. Tentacles can be classified as middle fold tentacles (MFT) and inner fold tentacles (IFT) according to their position with respect to the folds of the mantle margin. While MFT morphology indicates intense secretion of mucosubstances, no evidence for secretory activity was found for IFT. However, both tentacle types have appropriate ciliary distribution and length to promote mucus transportation for cleaning and lubrication. Protective and sensory functions are discussed based on different lines of evidence, including secretion, cilia distribution, musculature, and innervation. Our results support the homology of MFT and IFT only for Pterioidea and Ostreoidea, considering their morphology, the presence of ciliated receptors at the tips, and branched innervation pattern. This is in accordance with recent phylogenetic hypotheses that support the close relationship between these superfamilies. In contrast, major structural differences indicate that MFT and IFT are probably not homologous across all pteriomorphians. By applying integrative microscopy, we were able to reveal anatomical elements that are essential for the understanding of homology and function when dealing with such superficially similar structures.  相似文献   

5.
Athyrisinine brachiopods from the Upper Silurian of Russia and the Lower–Middle Devonian of China and north Vietnam include over 70 species belonging to Athyrisina and Parathyrisina ; generic and subfamilial diagnoses are emended. Five genera are considered synonyms of Athyrisina and three of Parathyrisina . A neotype is selected and illustrated for Athyrisina squamosa , the type species of Athyrisina . Four nomina nova , Athyrisina xui , Parathyrisina wani , P. minima , and P. cheni , are suggested as new substitute names for Athyrisina tumida Wang, in Xu et al. 1978 (primary homonymy), Athyrisinoides ganxiensis Wan, in Xu et al. 1978, Parathyrisina minor Zhang, in Zhang and Fu 1983, and Athyrisinoides tudilingensis Chen, 1979 (secondary homonyms) respectively. A new genus, Bruntosina , is described from the Emsian to Eifelian of the Qinling region. A new subfamily, Homeathyridinae, is erected within the Athyrididae with Homeathyris , Pseudohomeospira , and Squamathyris included, revised and their diagnoses emended. Homeathyris incisus sp. nov. is described from the Ludfordian of Novaya Zemlya. Ikella is revised and excluded from the athyrisinins. The origin and dispersal of the homeathyridins and the athyrisinins are discussed.  相似文献   

6.
Regulation of angiogenesis by nitric oxide (NO) is controversial since NO has been shown to have both pro- and anti-angiogenic effects. In this study, we examined the effect of the NO donor, S-nitro-N-acetyl-penicillamine (SNAP), on in vitro angiogenesis, and the mechanisms involved: PKC activity, ERK and c-Jun phosphorylation, and AP-1 DNA binding activity, in microvascular endothelial cells. SNAP, at 0.5-4 mM, significantly and dose-dependently inhibited angiogenesis, PKC activity, and ERK and c-Jun phosphorylation up to 80%, 83%, and 63% and 73%, respectively. SNAP at concentrations > 2mM also abolished AP-1 binding activity. Lower concentrations of SNAP (0.1-0.3 mM) significantly increased angiogenesis, PKC activity, and ERK and c-Jun phosphorylation up to 46%, 60%, and 61% and 180%, respectively. These findings indicate that the dual pro- and anti-angiogenic actions of NO are dose-dependent and suggest that they are mediated by PKC and ERK acting on AP-1.  相似文献   

7.
自然保护区生态旅游对野生动物的影响   总被引:17,自引:2,他引:15  
马建章  程鲲 《生态学报》2008,28(6):2818-2818~2827
目前中国的很多自然保护区开展了生态旅游,但这类活动对野生动物的影响研究却十分薄弱,因此十分有必要在介绍欧美、澳洲学者的研究进展基础上,针对我国的研究现状,提出该领域的研究方向、监测和管理策略.自然保护区的生态旅游活动主要有野生动物观赏、徒步行走、摄影、野外宿营、山地车或雪地车、电动或机动艇游湖、溪涧漂流、环境教育、社区访问等,旅游活动类型、范围、强度、时空分布等是影响对野生动物干扰大小的主要因素.生态旅游对野生动物的影响包括直接影响(个体的行为反应和生理指标改变、繁殖力降低、种群分布和物种组成的改变等)和间接影响(生境破坏、外来种散布和环境污染等).国外生态旅游对鸟类的影响研究较多,主要集中鸟类的惊飞反应、取食、能量消耗、繁殖等方面;对兽类影响的研究主要集中在行为、生理指标改变、种群数量等方面.我国未来的研究应注重收集基础性研究数据和深入探讨一些理论与应用问题,要运用多种技术手段对自然保护区野生动物的行为、生理、种群动态、物种多样性、生境质量、游客的时空分布、态度和行为等进行长期监测,而后将其结果应用到野生动物、生境以及游客的管理决策中去.另外,研究中应重视自然科学和社会科学的多学科交叉融合.  相似文献   

8.
Twenty carbohydrates (C), 18 nitrogen compounds (N), and 9 vitamins were examined for their effects on the growth and conidiation of the nematode-egg-parasitic fungi Arkansas Fungus 18 (ARF18, isolate 908) and Pochonia chlamydospora var. chlamydospora in solid and liquid cultures. Glycogen was the best, and inulin, D-(+)-galactose, and soluble starch were good C sources for the growth of ARF18 in both solid and liquid cultures. ARF18 could not utilize alpha-cellulose in liquid; alpha-lactose and D-mannitol in solid; and D-(+)-xylose, L-(-)-sorbose, and D-(-)-ribose in both solid and liquid cultures. Casein was the best N source for ARF18 growth in both solid and liquid cultures and L-aspartic acid, DL-glutamic acid, peptone, and L-histidine were good in solid culture. ARF18 could not utilize L-cystine and L-tyrosine in solid culture, and L-cystine, DL-methionine, peptone, L-proline, and ammonium nitrate in liquid culture. Supplement of vitamins appeared to be unnecessary for ARF18 to grow. For P. chlamydospora var. chlamydospora growth, all test C sources, except L-(-)-sorbose, alpha-cellulose, citric acid, and D-(+)-glucose, were good in both solid and liquid cultures. Most N compounds were good for P. chlamydospora var. chlamydospora growth with casein and peptone the best. Vitamins had limited effect on P. chlamydospora var. chlamydospora growth. P. chlamydospora var. chlamydospora conidiation was well supported by D-(-)-ribose, D-(-)-fructose, melibiose, and D-(+)-galactose as C sources and by L-aspartic acid, DL-glutamic acid, and L-arginine as N sources. Excluding myo-inositol from the medium containing all other test vitamins increased P. chlamydospora var. chlamydospora conidiation, while excluding pyridoxine appeared to reduce its conidiation.  相似文献   

9.
Olson, G. A., R. D. Olson and A. J. Kastin. Endogenous opiates: 1996. Peptides 18(10) 1651–1688, 1997.—This paper is the nineteenth installment of our annual review of research concerning the opiate system. It summarizes papers published during 1996 reporting the behavioral effects of the opiate peptides and antagonists, excluding the purely analgesic effects, although stress-induced analgesia is included. The specific topics covered this year include stress, tolerance and dependence; eating; drinking; gastrointestinal, renal, and hepatic function; mental illness and mood; learning, memory, and reward; cardiovascular responses; respiration and thermoregulation; seizures and other neurological disorders; electrical-related activity; general activity and locomotion; sex, pregnancy, and development; immunological responses; and other behaviors.  相似文献   

10.
贵州罗甸纳水上石炭统(宾夕法尼亚亚系)地层的再研究   总被引:5,自引:0,他引:5  
本文详细描述了贵州罗甸纳水上石炭统(宾夕法尼亚亚系)剖面的生物地层和年代地层,其牙形刺序列自上而下可详细划分为:Streptognathodus isolatus, S. wabaunsensis, S. tenuialveus, S. firmus, Idiognathodus nashuiensis , Streptognathodus simulator, S. guizhouensis , S. gracilis-S, excelsus , S. cancellosus , S. clavatulus , S. nodocarinatus , Idiognathodus podolskensis , Mesogondolella clarki -Idiognathodus robustus , Diplognathodus ophanus-D, ellesmerensis, Idiognathoides ouachitensis, Streptognathodus expansus, Idiognathoides sulcatus parva, Idiognathodus primulus-Neognathodus bassleri, Idiognathodus primulus-Neognathodus symmetricus, Neognathodus symmetricus, Idiognathoides corrugatus-I, pacificus, I. sinuatus, I. sulcatus sulcatus, Declinognathodus noduli ferus 和 Gnathodus bilineatus bollandensis 等带。 Declinognathodus noduliferus 和 Streptognathodus isolatus 的首次出现分别代表上石炭统(宾夕法尼亚亚系)和二叠系的开始。根据牙形刺和有孔虫的序列,罗甸纳水剖面的上石炭统(宾夕法尼亚亚系)地层自下而上可划分为罗苏阶(Luosuan)、滑石板阶(Huashibanian)、达拉阶(Dalaan)和马平阶(Mapingian),并可与俄罗斯的巴什基尔阶(Bashkirian)、莫斯科阶(Moscovian)、卡西莫夫阶(Kasimovian)和格舍尔阶(Gzhelian),北美的莫罗阶(Morrowan)、阿托克阶(Atokan)、得梅因阶(Desmoinesian)、密苏里阶(Missourian)和弗吉尔阶(Virgilian)进行对比。另外,本文也详细讨论了剖面中的石炭系中间界线及石炭-二叠系界线。  相似文献   

11.
B. A. Manny  D. Kenaga 《Hydrobiologia》1991,219(1):269-279
Despite extensive urbanization of its watershed, the Detroit River still supports diverse fish and wildlife populations. Conflicting uses of the river for waste disposal, water withdrawals, shipping, recreation, and fishing require innovative management. Chemicals added by man to the Detroit River have adversely affected the health and habitats of the river's plants and animals. In 1985, as part of an Upper Great Lakes Connecting Channels Study sponsored by Environment Canada and the U.S. Environmental Protection Agency, researchers exposed healthy bacteria, plankton, benthic macroinvertebrates, fish, and birds to Detroit River sediments and sediment porewater. Negative impacts included genetic mutations in bacteria; death of macroinvertebrates; accumulation of contaminants in insects, clams, fishes, and ducks; and tumor formation in fish. Field surveys showed areas of the river bottom that were otherwise suitable for habitation by a variety of plants and animals were contaminated with chlorinated hydrocarbons and heavy metals and occupied only by pollution-tolerant worms. Destruction of shoreline wetlands and disposal of sewage and toxic substances in the Detroit River have reduced habitat and conflict with basic biological processes, including the sustained production of fish and wildlife. Current regulations do not adequately control pollution loadings. However, remedial actions are being formulated by the U.S. and Canada to restore degraded benthic habitats and eliminate discharges of toxic contaminants into the Detroit River.Contribution 738 of the National Fisheries Research Center-Great Lakes, 1451 Green Road, Ann Arbor, MI 48105, U.S.A.  相似文献   

12.
Chemical basis of inflammation-induced carcinogenesis   总被引:11,自引:0,他引:11  
Chronic inflammation induced by biological, chemical, and physical factors has been associated with increased risk of human cancer at various sites. Inflammation activates a variety of inflammatory cells, which induce and activate several oxidant-generating enzymes such as NADPH oxidase, inducible nitric oxide synthase, myeloperoxidase, and eosinophil peroxidase. These enzymes produce high concentrations of diverse free radicals and oxidants including superoxide anion, nitric oxide, nitroxyl, nitrogen dioxide, hydrogen peroxide, hypochlorous acid, and hypobromous acid, which react with each other to generate other more potent reactive oxygen and nitrogen species such as peroxynitrite. These species can damage DNA, RNA, lipids, and proteins by nitration, oxidation, chlorination, and bromination reactions, leading to increased mutations and altered functions of enzymes and proteins (e.g., activation of oncogene products and/or inhibition of tumor-suppressor proteins) and thus contributing to the multistage carcinogenesis process. Appropriate treatment of inflammation should be explored further for chemoprevention of human cancers.  相似文献   

13.
ABSTRACT Waterfowl frequently acquire high-energy agricultural seeds in harvested and unharvested croplands during migration and winter. Estimates of agricultural seed biomass in harvested and unharvested corn, soybean, and grain sorghum fields do not exist or are outdated for the southeastern United States. Therefore, we estimated seed biomass in 105 harvested and 59 unharvested corn, soybean, and grain sorghum fields across 4 climate regions in Tennessee, USA, from September through January 2006 and 2007. We also used estimates of seed biomass to calculate duck-energy days (DEDs) in December and January when migratory waterfowl abundance peaks in the southeastern United States. Mean biomass of corn, soybean, and grain sorghum seed in harvested fields declined 239 kg/ha to 39 kg/ha, 118 kg/ha to 26 kg/ha, and 392 kg/ha to 19 kg/ha, respectively, from postharvest to January. Continuous monthly rates of decline were 64% for corn, 84% for soybean, and 74% for grain sorghum. Agricultural seed biomass in harvested corn and grain sorghum fields dropped below the waterfowl giving-up density (i.e., 50 kg/ha) in 3 months; soybean dropped below this threshold 1 month postharvest. Mean DEDs/ha in harvested corn, soybean, and grain sorghum fields were low (274, 90, and 27, respectively) in January, and DEDs were zero in >85% of fields. In unharvested corn, soybean, and grain sorghum fields, mean DEDs/ha in January were high (69,000, 18,000, and 26,000, respectively), and continuous rates of decline (3%, 7%, and 18%, respectively) were much lower than for harvested crops. Waterfowl biologists in the Southeast should use our estimates of agricultural seed biomass in DED calculations. We also recommend that biologists provide unharvested grain fields and natural wetlands for migrating and wintering waterfowl because seed resources are low in harvested agricultural fields.  相似文献   

14.
采用液相色谱研究白藜芦醇在紫斑牡丹、花生和巨峰葡萄几种经济植物各部位的分布情况。结果表明紫斑牡丹籽和果荚的含量远高于花生和巨峰葡萄。花生白藜芦醇含量最低。紫斑牡丹、花生和巨峰葡萄各部位白藜芦醇分布情况如下:紫斑牡丹叶、紫斑牡丹侧枝、紫斑牡丹茎和紫斑牡丹根中均不含有白藜芦醇,而紫斑牡丹籽和紫斑牡丹果荚中含有白藜芦醇,其中紫斑牡丹籽白藜芦醇含量为0.87‰,紫斑牡丹果荚白藜芦醇含量为0.26‰。花生叶、花生胚乳和花生胚芽中均不含有白藜芦醇,而花生侧枝、花生壳、花生皮、花生茎、花生侧根、花生主根中含有白藜芦醇含有白藜芦醇,其含量为花生侧枝3 mg·kg-1、花生茎11 mg·kg-1、花生壳12 mg·kg-1、花生皮15 mg·kg-1、花生侧根5 mg·kg-1、花生主根10 mg·kg-1。经检测发现葡萄肉,葡萄皮,葡萄籽,葡萄蒂四部分中含有白藜芦醇,其中葡萄肉白藜芦醇含量为0.017‰,葡萄皮白藜芦醇含量为0.028‰,葡萄籽白藜芦醇含量为0.005‰,葡萄蒂和其邻近枝白藜芦醇含量为0.12‰。检测说明这几种植物中花生皮、花生壳、葡萄皮、葡萄籽、葡萄蒂、牡丹籽、牡丹荚具有一定的药用价值和经济价值。  相似文献   

15.
Anthocyanins from tart cherries, Prunus cerasus L. (Rosaceae) cv. Balaton and Montmorency; sweet cherries, Prunus avium L. (Rosaceae); bilberries, Vaccinum myrtillus L. (Ericaceae); blackberries, Rubus sp. (Rosaceae); blueberries var. Jersey, Vaccinium corymbosum L. (Ericaceae); cranberries var. Early Black, Vaccinium macrocarpon Ait. (Ericaceae); elderberries, Sambucus canadensis (Caprifoliaceae); raspberries, Rubus idaeus (Rosaceae); and strawberries var. Honeoye, Fragaria x ananassa Duch. (Rosaceae), were investigated for cyclooxygenase inhibitory and antioxidant activities. The presence and levels of cyanidin-3-glucosylrutinoside 1 and cyanidin-3-rutinoside 2 were determined in the fruits using HPLC. The antioxidant activity of anthocyanins from cherries was comparable to the commercial antioxidants, tert-butylhydroquinone, butylated hydroxytoluene and butylated hydroxyanisole, and superior to vitamin E, at a test concentration of 125 microg/ml. Anthocyanins from raspberries and sweet cherries demonstrated 45% and 47% cyclooxygenase-I and cyclooxygenase-II inhibitory activities, respectively, when assayed at 125 microg/ml. The cyclooxygenase inhibitory activities of anthocyanins from these fruits were comparable to those of ibuprofen and naproxen at 10 microM concentrations. Anthocyanins 1 and 2 are present in both cherries and raspberry. The yields of pure anthocyanins 1 and 2 in 100 g Balaton and Montmorency tart cherries, sweet cherries and raspberries were 21, 16.5; 11, 5; 4.95, 21; and 4.65, 13.5 mg, respectively. Fresh blackberries and strawberries contained only anthocyanin 2 in yields of 24 and 22.5 mg/100 g, respectively. Anthocyanins 1 and 2 were not found in bilberries, blueberries, cranberries or elderberries.  相似文献   

16.
高程  郭良栋 《生物多样性》2022,30(10):22429-23168
微生物主要包括细菌、真菌、古菌、病毒等类群, 是地球上出现时间最早、分布最广泛、个体数量最多, 以及物种和基因多样性十分丰富的生物类群。为了适应各种生境, 微生物衍生出腐生、寄生、共生等多样的生存策略, 在生物地球化学循环、生态系统演替与稳定性、环境修复以及人类健康等方面发挥着重要作用。传统的微生物监测方法限制了我们对微生物多样性的认知; 但是, 近年来高通量测序技术和生物信息学的发展极大推动了微生物多样性的研究进展。本文概述了近年来在微生物多样性分布格局与维持、群落构建以及功能属性多样性的最新进展; 总结分析了细菌、古菌、真菌的多样性纬度分布格局及其驱动因子, 选择、扩散、成种、漂变等过程对细菌、古菌、真菌的群落构建的贡献, 以及细菌和真菌的形态、生理生化、生长繁殖、扩散、基因组等功能性状的多样性; 提出了未来微生物多样性研究的重要领域: 环境宏真菌组研究, 微生物多样性与生态系统多功能性的关系研究, 以及微生物互作网络的生态功能研究。  相似文献   

17.
The wetlands of 21 countries and territories of the Pacific Islands region are reviewed: American Samoa, Cook Islands, Federated States of Micronesia, Fiji, French Polynesia, Guam, Kiribati, Marshall Islands, Nauru, New Caledonia, Niue, Northern Mariana Islands, Palau, Papua New Guinea, Samoa, Solomon Islands, Tokelau, Tonga, Tuvalu, Vanuatu, and Wallis and Futuna. The regions’ wetlands are classified into seven systems: coral reefs, seagrass beds, mangrove swamps, riverine, lacustrine, freshwater swamp forests and marshes. The diversity of species in each of these groups is at near global maxima at the west of the region, with decline towards the east with increasing isolation, and decreasing island size and age. The community structure is unique in each country, and many have endemic species with the habitat isolation that epitomises this island region. There remain, however, some serious gaps in basic inventory, particularly in freshwater biodiversity. Threats to wetlands include introduced freshwater species, loss of wetlands adjacent to urban growth, downstream effects of mining and land clearance, and over-use of mangrove, seagrass and coral reef resources by predominant subsistence economies that remain in this region. Only five countries are signatories to the Ramsar convention on wetlands, and this only recently with seven sites. Wetland managers have identified the need for community education, baseline surveys and monitoring, better legislation and policy for wetland management, and improved capacity of local communities to allow the wise use of their wetlands.  相似文献   

18.
Biosorbents for heavy metals removal and their future   总被引:5,自引:0,他引:5  
A vast array of biological materials, especially bacteria, algae, yeasts and fungi have received increasing attention for heavy metal removal and recovery due to their good performance, low cost and large available quantities. The biosorbent, unlike mono functional ion exchange resins, contains variety of functional sites including carboxyl, imidazole, sulphydryl, amino, phosphate, sulfate, thioether, phenol, carbonyl, amide and hydroxyl moieties. Biosorbents are cheaper, more effective alternatives for the removal of metallic elements, especially heavy metals from aqueous solution. In this paper, based on the literatures and our research results, the biosorbents widely used for heavy metal removal were reviewed, mainly focusing on their cellular structure, biosorption performance, their pretreatment, modification, regeneration/reuse, modeling of biosorption (isotherm and kinetic models), the development of novel biosorbents, their evaluation, potential application and future. The pretreatment and modification of biosorbents aiming to improve their sorption capacity was introduced and evaluated. Molecular biotechnology is a potent tool to elucidate the mechanisms at molecular level, and to construct engineered organisms with higher biosorption capacity and selectivity for the objective metal ions. The potential application of biosorption and biosorbents was discussed. Although the biosorption application is facing the great challenge, there are two trends for the development of the biosorption process for metal removal. One trend is to use hybrid technology for pollutants removal, especially using living cells. Another trend is to develop the commercial biosorbents using immobilization technology, and to improve the biosorption process including regeneration/reuse, making the biosorbents just like a kind of ion exchange resin, as well as to exploit the market with great endeavor.  相似文献   

19.
We present an updated worldwide phylogenetic classification of Poaceae with 11 783 species in 12 subfamilies, 7 supertribes, 54 tribes, 5 super subtribes, 109 subtribes, and 789 accepted genera. The subfamilies (in descending order based on the number of species) are Pooideae with 4126 species in 219 genera, 15 tribes, and 34 subtribes; Panicoideae with 3325 species in 242 genera, 14 tribes, and 24 subtribes; Bambusoideae with 1698 species in 136 genera, 3 tribes, and 19 subtribes; Chloridoideae with 1603 species in 121 genera, 5 tribes, and 30 subtribes; Aristidoideae with 367 species in three generaand one tribe; Danthonioideae with 292 species in 19 generaand 1 tribe; Micrairoideae with 192 species in nine generaand three tribes; Oryzoideae with 117 species in 19 genera, 4 tribes, and 2 subtribes; Arundinoideae with 36 species in 14 genera and 3 tribes; Pharoideae with 12 species in three generaand one tribe; Puelioideae with 11 species in two generaand two tribes; and the Anomochlooideae with four species in two generaand two tribes. Two new tribes and 22 new or resurrected subtribes are recognized. Forty-five new (28) and resurrected (17) genera are accepted, and 24 previously accepted genera are placed in synonymy. We also provide an updated list of all accepted genera including common synonyms, genus authors, number of species in each accepted genus, and subfamily affiliation. We propose Locajonoa, a new name and rank with a new combination, L. coerulescens. The following seven new combinations are made in Lorenzochloa: L. bomanii, L. henrardiana, L. mucronata, L. obtusa, L. orurensis, L. rigidiseta, and L. venusta.  相似文献   

20.
The Cuban species of Calisto are reviewed based on the morphology of adult and immature stages, as well as DNA sequences of six genes (COI, EF1α, wingless, GAPDH, RpS5, CAD). A new species, Calisto occultasp. n., is described from the northeastern Cuban mountains. Calisto smintheus Bates, 1935 and Calisto bruneri, Michener 1949 are revised and revalidated. A new status, the species level, is proposed for Calisto brochei, Torre 1973, Calisto muripetens, Bates 1939 and Calisto bradleyi, Munroe 1950. The immature stages of Calisto smintheus, Calisto brochei,and Calisto occulta are described for the first time, and those of Calisto herophile, Hübner 1823 are redescribed. Useful morphological characters for adults are the shape and conspicuousness of androconial patch, the number and relative size of white dots on underside of hindwing, the shape of aedeagus, the shape of digitiform projection of genitalia valve, the shape and relative size of tegumen and uncus, the relative size of female genitalia, the height of sterigmal ring dorsal crown of the latter, and the relative size of corpus bursae and ductus bursae. For the immature stages, the most important characters are the color pattern of head capsule, the number and width of longitudinal lines of body, in the larvae; and the color pattern and the absence or presence of dorsal ridges on the abdomen of pupae. The phylogenetic relationships between the Cuban Calisto species are quite robust and well-supported; however, conflict between mitochondrial and nuclear datasets was detected in Calisto brochei, Calisto muripetens and to a lesser degree in Calisto bradleyi.  相似文献   

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