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1.
Waicheim María Agustina Mendes Marques Taísa Rauque Carlos Alejandro Viozzi Gustavo 《Systematic parasitology》2021,98(2):131-139
Systematic Parasitology - A new parasitic copepod, Ergasilus yandemontei n. sp., is described based on 10 adult females collected from the gills of the atherinid silverside Odontesthes hatcheri... 相似文献
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Samples of microphytobenthos from the Tagus estuary were analysed for photosynthetic pigments by spectrophotometry and High
Performance Liquid Chromatography (HPLC). Chlorophyll a values obtained with HPLC and spectrophotometry methods presented a highly significant positive correlation for both spectrophotometric
methods used (with and without the correction for pheopigments), but this relationship depended on the type of sediment. We
concluded that spectrophotometric methods give reliable Chl-a values, being suited for routine analysis, when a vast number of replicates is needed. However, for the correct estimation
of pheopigments, HPLC analysis is indispensable. In the literature, Chl-a estimations are expressed per content (μg g−1) or concentration (mg m−2). We discuss the influence of sediment type on the results depending on the type of unit used, and propose a simple conversion
factor based on sediment water content. 相似文献
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Cristiana Leite N. Tatiana Silva Sandrine Mendes Andreia Ribeiro Joana Paes de Faria Tania Louren?o Francisco dos Santos Pedro Z. Andrade Carla M. P. Cardoso Margarida Vieira Artur Paiva Cláudia L. da Silva Joaquim M. S. Cabral Jo?o B. Relvas Mário Gr?os 《PloS one》2014,9(10)
Mesenchymal stem cells (MSCs) are viewed as safe, readily available and promising adult stem cells, which are currently used in several clinical trials. Additionally, their soluble-factor secretion and multi-lineage differentiation capacities place MSCs in the forefront of stem cell types with expected near-future clinical applications. In the present work MSCs were isolated from the umbilical cord matrix (Wharton''s jelly) of human umbilical cord samples. The cells were thoroughly characterized and confirmed as bona-fide MSCs, presenting in vitro low generation time, high proliferative and colony-forming unit-fibroblast (CFU-F) capacity, typical MSC immunophenotype and osteogenic, chondrogenic and adipogenic differentiation capacity. The cells were additionally subjected to an oligodendroglial-oriented step-wise differentiation protocol in order to test their neural- and oligodendroglial-like differentiation capacity. The results confirmed the neural-like plasticity of MSCs, and suggested that the cells presented an oligodendroglial-like phenotype throughout the differentiation protocol, in several aspects sharing characteristics common to those of bona-fide oligodendrocyte precursor cells and differentiated oligodendrocytes. 相似文献
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Sarah E. Smith Boris Rubinstein Inês Mendes Pinto Brian D. Slaughter Jay R. Unruh Rong Li 《The Journal of cell biology》2013,202(7):1091-1106
The ability to break symmetry and polarize through self-organization is a fundamental feature of cellular systems. A prevailing theory in yeast posits that symmetry breaking occurs via a positive feedback loop, wherein the adaptor protein Bem1 promotes local activation and accumulation of Cdc42 by directly tethering Cdc42GTP with its guanine nucleotide exchange factor (GEF) Cdc24. In this paper, we find that neither Bem1 nor the ability of Bem1 to bind Cdc42GTP is required for cell polarization. Instead, Bem1 functions primarily by boosting GEF activity, a role critical for polarization without actin filaments. In the absence of actin-based transport, polarization of Cdc42 is accomplished through Rdi1, the Cdc42 guanine nucleotide dissociation inhibitor. A mathematical model is constructed describing cell polarization as a product of distinct pathways controlling Cdc42 activation and protein localization. The model predicts a nonmonotonic dependence of cell polarization on the concentration of Rdi1 relative to that of Cdc42. 相似文献
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Savio de Siqueira Ferreira Milton Yutaka Nishiyama Jr Andrew H Paterson Glaucia Mendes Souza 《Genome biology》2013,14(6):210
The Saccharinae, especially sugarcane, Miscanthus and sorghum, present remarkable characteristics for bioenergy production. Biotechnology of these plants will be important for a sustainable feedstock supply. Herein, we review knowledge useful for their improvement and synergies gained by their parallel study. 相似文献
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Titimbera n. gen. is erected based on the males of three new species from South and Central America: T. amazonica n. sp. from the Amazon region, Brazil; T. titi n. sp. from Venezuela and T. laselvensis n. sp. from Costa Rica. The combination of bare eyes and wing membrane; antenna without strong apical seta; scalpellate acrostichals in mid scutum; costa strongly extended; R4+5 ending opposite to M3+4; Cu1 strongly curved to slightly sinuous; anal point sitting high on tergite IX, nearly parallel-sided with bluntly rounded apex; and club-shaped to subtriangular gonostylus with distinct heel will separate the genus from all other orthoclads. 相似文献
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One of the unresolved questions in the field of cell division is how the actomyosin cytoskeleton remains structurally organized while generating the contractile force to divide one cell into two. In analogy to the actomyosin-based force production mechanism in striated muscle, it was originally proposed that contractile stress in the actomyosin ring is generated via a sliding filament mechanism within an organized sarcomere-like array. However, over the last 30 years, ultrastructural and functional studies have noted important distinctions between cytokinetic structures in dividing cells and muscle sarcomeres. Myosin-II motor activity is not always required, and there is evidence that actin depolymerization contributes to contraction. In this Review, the architecture and contractile dynamics of the actomyosin ring at the cell division plane will be discussed. We will report the interdisciplinary advances in the field as well as their integration into a mechanistic understanding of contraction in cell division and in other biological processes that rely on an actomyosin-based force-generating system. 相似文献