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71.
David Wool 《Population Ecology》1973,15(2):90-98
Summary A quantitative method is suggested for measuring the similarity of seasonal abundance patterns of different animal species.
The method was applied to two sets of field data and produced biologically meaningful and interesting results. 相似文献
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74.
为研究南海柳珊瑚共附生草酸青霉SCSGAF0023的聚酮合酶(PKS)生物学功能,采用农杆菌介导法构建草酸青霉SCSGAF0023的Pks敲除株ΔPks,比较野生菌株及ΔPks的生长发育及环境适应性差异。以草酸青霉SCSGAF0023分生孢子为受体,p0380-hygB为双元载体,成功实现草酸青霉SCSGAF0023的遗传转化。结果表明:农杆菌浓度为OD600=0.5,在200μmol/L 乙酰丁香酮(AS)诱导下与107个/ml草酸青霉SCSGAF0023孢子于25℃共孵育时转化效率最高。基于上述转化体系,成功获得Pks敲除株ΔPks,并首次证实Pks正向调控草酸青霉SCSGAF0023产孢,但不影响其对环境的适应性。这为进一步系统研究真菌PKSs及聚酮化合物对真菌生长发育与环境适应性的影响提供素材。 相似文献
75.
Alkyl phenol polyethoxylates (APEOs) are a major group of high production volume chemicals, extensively used as nonionic surfactants in industrial, agricultural and domestic sectors. These surfactants and its respective metabolites are found to be persistent and toxic. Mainly, they act as endocrine disruptors by mimicking the natural hormones. India being a developing country, witnesses pollution due to various industries including tannery. In the present study, sediment samples were collected from the Vellore district of Tamil Nadu, India to investigate the occurrence of APEOs. The sediments were extracted by ultrasonication and analyzed in a liquid chromatography mass spectrometer. Octyl phenol ethoxylates (OPEOs) were not observed in any of the samples. Nonyl phenol ethoxylates (NPEOs) were detected in the range of ND – 36 mg/kg with 85 % detection frequency. The occurrence of NPEOs in sediment indicates its wide usage in tannery and its partitioning behavior in environment. The levels of NPEOs in the study were found to be unsafe according to the sediment guidelines of various studies. Since NPEOs were observed in sediment samples, possibilities of occurrence of their monomers and metabolites cannot be ruled out. Therefore, further studies are warranted for understanding the levels of monomers and metabolites in order to ascertain the environmental risks more appropriately. 相似文献
76.
Changwei Bi Na Lu Zhen Huang Junyuan Chen Chunpeng He Zuhong Lu 《Ecology and evolution》2020,10(15):8210-8224
Global climatic fluctuations governed the ancestral demographic histories of species and contributed to place the current population status into a more extensive ecological and evolutionary context. Genetic variations will leave unambiguous signatures in the patterns of intraspecific genetic variation in extant species since the genome of each individual is an imperfect mosaic of the ancestral genomes. Here, we report the genome sequences of 20 Branchiostoma individuals by whole‐genome resequencing strategy. We detected over 140 million genomic variations for each Branchiostoma individual. In particular, we applied the pairwise sequentially Markovian coalescent (PSMC) method to estimate the trajectories of changes in the effective population size (Ne) of Branchiostoma population during the Pleistocene. We evaluated the threshold of sequencing depth for proper inference of demographic histories using PSMC was ≥25×. The PSMC results highlight the role of historical global climatic fluctuations in the long‐term population dynamics of Branchiostoma. The inferred ancestral Ne of the Branchiostoma belcheri populations from Zhanjiang and Xiamen (China) seawaters was different in amplitude before the first (mutation rate = 3 × 10?9) or third glaciation (mutation rate = 9 × 10?9) of the Pleistocene, indicating that the two populations most probably started to evolve in isolation in their respective seas after the first or third glaciation of the Pleistocene. A pronounced population bottleneck coinciding with the last glacial maximum was observed in all Branchiostoma individuals, followed by a population expansion occurred during the late Pleistocene. Species that have experienced long‐term declines may be especially vulnerable to recent anthropogenic activities. Recently, the industrial pollution and the exploitation of sea sand have destroyed the harmonious living environment of amphioxus species. In the future, we need to protect the habitat of Branchiostoma and make full use of these detected genetic variations to facilitate the functional study of Branchiostoma for adaptation to local environments. 相似文献
77.
Selenium (Se) is an essential micronutrient in living organisms, having a narrow margin between essential and potentially toxic intake/exposure. Thus, the biochemistry of Se in living organisms must be studied in-depth to determine the underlying mechanism of Se cytotoxicity. In this study, we report the emergence of selenium nanovirus (SeNVs) in selenite-exposed fish (freshwater and saltwater) and plants (dryland) and its toxicity in them. SeNVs were found in both the abdomen and tail of Oryzias melastigma and saltwater Rhodeus ocellatus, which led to their death. The occurrence of the intracellular assembly of SeNVs was observed in the roots and leaves of corn Zea mays, but not in those of Limnobium laevigatum. SeNVs led to the death of Z. mays but caused chronic toxicity in L. laevigatum. SeNVs should be a system or structure that dissipates the intracellular redox gradients of the host cells, with simple information consisting Se–O, Se–N, or Se–S bond, that would ensure elemental Se ligand binding with nearly specific biomolecules in host cells, thereby maintaining their composition and stabilizing their structure. The multiple toxic effects of Se, therefore, could be the consequence of increase of entropy in the host cells caused by the intracellular assembly of SeNVs. This study may provide an insight into the underlying mechanism of Se in environmental toxicology and its applications in human health. 相似文献
78.
Chang-Li Yang Jian-Yu Meng Lv Zhou Meng-Shuang Yao Chang-Yu Zhang 《Cell stress & chaperones》2021,26(3):527
Spodoptera frugiperda (J. E. Smith) is a highly adaptable polyphagous migratory pest in tropical and subtropical regions. Small heat shock proteins (sHsps) are molecular chaperones that play important roles in the adaptation to various environment stressors. The present study aimed to clarify the response mechanisms of S. frugiperda to various environmental stressors. We obtained five S. furcifera sHsp genes (SfsHsp21.3, SfsHsp20, SfsHsp20.1, SfsHsp19.3, and SfsHsp29) via cloning. The putative proteins encoded by these genes contained a typical α-crystallin domain. The expression patterns of these genes during different developmental stages, in various tissues of male and female adults, as well as in response to extreme temperatures and UV-A stress were studied via real-time quantitative polymerase chain reaction. The results showed that the expression levels of all five SfsHsp genes differed among the developmental stages as well as among the different tissues of male and female adults. The expression levels of most SfsHsp genes under extreme temperatures and UV-A-induced stress were significantly upregulated in both male and female adults. In contrast, those of SfsHsp20.1 and SfsHsp19.3 were significantly downregulated under cold stress in male adults. Therefore, the different SfsHsp genes of S. frugiperda play unique regulatory roles during development as well as in response to various environmental stressors. 相似文献
79.
80.
Huda Ahmed Alghamdi 《Saudi Journal of Biological Sciences》2021,28(7):4082-4088
Since the first case report on COVID-19, its transmission took place rapidly across the globe. Currently, it is reported to be spread into a total of 216 countries and territories. The suppression on industrial and gasoline burning activities accompanied after COVID-19 lock down favorably boosted the nature to restore its deteriorated sections such as in air with the improved Air quality index and in water bodies with the natural tone of purity. Increased use of anti-viral drugs along with herbal therapies has been observed at mass scale as global intervention to prevent the disease. The use of personal protective equipment and disinfection strategies for the control of pandemic has dramatically increased the pollution of plastic and medical waste. This article aims to forecast and highlight the evidence-based impact/changes (+ive and -ive) of coronavirus on the environment, global interventions to prevent the disease along with the levels of effectiveness of personal used protective equipment to stop the spread of coronavirus. 相似文献