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1.
Valeria L. Martin-Albarracin Guillermo C. Amico Daniel Simberloff Martin A. Nu?ez 《PloS one》2015,10(11)
Introduction and naturalization of non-native species is one of the most important threats to global biodiversity. Birds have been widely introduced worldwide, but their impacts on populations, communities, and ecosystems have not received as much attention as those of other groups. This work is a global synthesis of the impact of nonnative birds on native ecosystems to determine (1) what groups, impacts, and locations have been best studied; (2) which taxonomic groups and which impacts have greatest effects on ecosystems, (3) how important are bird impacts at the community and ecosystem levels, and (4) what are the known benefits of nonnative birds to natural ecosystems. We conducted an extensive literature search that yielded 148 articles covering 39 species belonging to 18 families -18% of all known naturalized species. Studies were classified according to where they were conducted: Africa, Asia, Australasia, Europe, North America, South America, Islands of the Indian, of the Pacific, and of the Atlantic Ocean. Seven types of impact on native ecosystems were evaluated: competition, disease transmission, chemical, physical, or structural impact on ecosystem, grazing/ herbivory/ browsing, hybridization, predation, and interaction with other non-native species. Hybridization and disease transmission were the most important impacts, affecting the population and community levels. Ecosystem-level impacts, such as structural and chemical impacts were detected. Seven species were found to have positive impacts aside from negative ones. We provide suggestions for future studies focused on mechanisms of impact, regions, and understudied taxonomic groups. 相似文献
2.
An Ustilago maydis ergosterol biosynthesis mutant (A14) which is partially blocked in sterol 14alpha-demethylase (P45014DM) activity is described. This mutant accumulated the abnormal 14alpha-methyl sterols, eburicol, 14alpha-methylfecosterol, and obtusifoliol, along with significant amounts of ergosterol. Although the A14 mutant grew nearly as well as the wild type, it was impaired in cell extension growth, which indicated a dysfunction in apical cell wall synthesis. The mutant was also found to be hypersensitive to the azole fungicides penconazole and tebuconazole. 相似文献
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4.
Antisera raised against vimentin, the protein subunit of nonspecific intermediate-sized filaments (IFs), were used in conjunction with neurofilament (NF) antisera to study the early development of neurons and glia in the rat embryo. Vimentin-positive fibers spanning the entire thickness of the neural tube including the cerebral vesicles were first observed on Day 12, concomitant with the appearance of NF protein in more confined areas (anterolateral regions of spinal cord and brain stem; motor roots emerging from the NF-positive areas). From Day 15 onwards vimentin and NF antisera selectively decorated glia and neurons, respectively, both in vivo and in vitro. Before Day 15 it appeared that NF-positive structures also stained with antivimentin in cryostat sections. In vitro experiments confirmed the presence of vimentin in early differentiating neurons. NF-positive cells were observed which also reacted with antivimentin in cultures obtained from 13- and 14-day embryos, but not later in development. Most neurons in these cultures became vimentin negative after 2–3 days in vitro. 相似文献
5.
The signal produced by fluorescence in situ hybridization (FISH) often is inconsistent among cells and sensitivity is low. Small DNA targets on the chromatin are difficult to detect. We report here an improved nick translation procedure for Texas red and Alexa Fluor 488 direct labeling of FISH probes. Brighter probes can be obtained by adding excess DNA polymerase I. Using such probes, a 30 kb yeast transgene, and the rp1, rp3 and zein multigene clusters were clearly detected. 相似文献
6.
Daniele De Simone Lorella D’Amico Daniela Bressanin Emma Motta Tiziana Annesi 《Mycological Progress》2011,10(3):301-306
Thirteen isolates of Inonotus rickii/Ptychogaster cubensis, from different geographic provenances, were analyzed by sequencing ITS1, ITS 2 and 5,8S ribosomal RNA region. A phylogenetic
tree, also including sequences available in Genbank database, showed that the strains enclosed in this study fall into two
well-separated groups, one formed by isolates from Florida (USA) and the other one by isolates from Europe, Argentina and
China. Differences were also highlighted on the growth rate of mycelial cultures at different temperatures. In fact, although
the tested isolates generally attained the best growth at 30°C, isolates from Europe seem well adapted to higher temperatures
and went on growing at 40°C whilst the growth of isolates from Florida significantly decreased at 35°C. Since the teleomorph
I. rickii was never detected in Florida, and in this study noticeable differences were detected by analysis of ITS region, the existence
of two possible distinct species, not discriminated solely on the basis of morphological characters, could be suggested. 相似文献
7.
Vincenzo Amico Rosario Currenti Giovanna Oriente Mario Piattelli Corrado Tringali 《Phytochemistry》1981,20(6):1451-1453
The major lipid component of the brown seaweed Zonaria tournefortii was identified as the acylphlorogluconol (all Z)-2′-icosa-5,8,11,14,17-pentae 相似文献
8.
JA Kiernan 《Biotechnic & histochemistry》2013,88(5-6):203-210
Hexazonium pararosaniline is a valuable reagent that has been used in enzyme activity histochemistry for 50 years. It is an aqueous solution containing the tris-diazonium ion derived from pararosaniline, an aminotriarylmethane dye, and it contains an excess of nitrous acid that was not consumed in the diazotization reaction. Other investigators have found that immersion for 2 min in an acidic (pH 3.5) 0.0015 M hexazonium pararosaniline solution can protect cryostat sections of unfixed animal tissues from the deleterious effects of aqueous reagents such as buffered solutions used in immunohistochemistry, while preserving specific affinities for antibodies. In the present investigation hexazonium pararosaniline protected lymphoid tissue and striated muscle against the damaging effects of water or saline. The same protection was conferred on unfixed sections treated with dilute nitrous or hydrochloric acid in concentrations similar to those in hexazonium pararosaniline solutions. Model tissues (solutions, gels or films containing gelatin and/or bovine albumin) responded predictably to well known cross-linking (formaldehyde) or coagulant (mercuric chloride) fixatives. Hexazonium pararosaniline solutions prevented the dissolution of protein gels in water only after 9 or more days of contact, during which time considerable swelling occurred. It is concluded that there is no evidence for a “fixative” action of hexazonium pararosaniline. The protective effect on frozen sections of unfixed tissue is attributable probably to the low pH of the solution. 相似文献
9.
Anton Orlin Dolan Sondhi Matthew T. Witmer Matthew M. Wessel Jason G. Mezey Stephen M. Kaminsky Neil R. Hackett Kaleb Yohay Barry Kosofsky Mark M. Souweidane Michael G. Kaplitt Donald J. D’Amico Ronald G. Crystal Szilárd Kiss 《PloS one》2013,8(8)
Background
Late infantile neuronal ceroid lipofuscinosis (LINCL), one form of Batten’s disease is a progressive neurodegenerative disorder resulting from a CLN2 gene mutation. The spectrum of ophthalmic manifestations of LINCL and the relationship with neurological function has not been previously described.Methods
Patients underwent ophthalmic evaluations, including anterior segment and dilated exams, optical coherence tomography, fluorescein and indocyanine green angiography. Patients were also assessed with the LINCL Neurological Severity Scale. Ophthalmic findings were categorized into one of five severity scores, and the association of the extent of ocular disease with neurological function was assessed.Results
Fifty eyes of 25 patients were included. The mean age at the time of exam was 4.9 years (range 2.5 to 8.1). The mean ophthalmic severity score was 2.6 (range 1 to 5). The mean neurological severity score was 6.1 (range 2 to 11). Significantly more severe ophthalmic manifestations were observed among older patients (p<0.005) and patients with more severe neurological findings (p<0.03). A direct correlation was found between the Ophthalmic Severity Scale and the Weill Cornell Neurological Scale (p<0.002). A direct association was also found between age and the ophthalmic manifestations (p<0.0002), with older children having more severe ophthalmic manifestations.Conclusions
Ophthalmic manifestations of LINCL correlate closely with the degree of neurological function and the age of the patient. The newly established LINCL Ophthalmic Scale may serve as an objective marker of LINCL severity and disease progression, and may be valuable in the evaluation of novel therapeutic strategies for LINCL, including gene therapy. 相似文献10.