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71.
Measures of population productivity and individual survival are essential for effective conservation management and scientific investigations. In studies of birds, individuals are often marked with unique colour band combinations to enable estimates of population vital rates. If birds are banded in the nest this must be done at the correct stage in nestling development. If nestlings are banded too early it can lead to leg damage. If they are banded too late it can cause early fledging and reduced survival. Here, we use photographs to guide estimation of the best stage to band North Island robin (Petroica longipes), or toutouwai, nestlings, which is typically at 9–12 days of age. 相似文献
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Konstantin A. Lusta Il Kyung Chung Ill Whan Sul Hee Sung Park Dong Ill Shin 《Process Biochemistry》2000,35(10):543-1182
Aerobic cells of a fungus isolate Aspergillus sp. CX-1 have been immobilized in macroporous cryoPAG and in different composite cryoPAGs — fibrous adjunct carriers. The productivity of the extracellular enzymes (exo-1.4-β-glucanase, endo-1.4-β-glucanase, β-glucosidase and xylanase), and the viability, growth and ultrastructure of the immobilized fungus have been studied. The enzyme activities and stability during long-term repeated batch cultivation in the immobilized fungus were higher than in free mycelia when batch cultivated. The fungus immobilized in the composite cryoPAG, containing polypropylene non-woven fabric, possessed the highest exo-1.4-β-glucanase activity, the longest durability of enzyme production (85 days) and the most reliable mechanical strength. The fungus immobilized in porous composite cryogel possessed a variety of advantages including easy control of cryogel porosity, improved mechanical strength and durability, simplicity of construction, high enzyme productivity and high stability. 相似文献
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ZDENK IKA 《The Journal of eukaryotic microbiology》1978,25(1):50-56
SYNOPSIS. The fine structure of schizonts and free merozoites of the neogregarine Farinocystis tribolii Weiser, and their development in the fat body of larval Tribolium castaneum were studied.
The surface of a multinucleate schizont and that of a uninucleate merozoite is covered by a double-layered membrane. Rhoptries and micronemes are present. The cytoplasm is packed with ribosomes and also contains dark bodies. Mitochondria are of the vesicular type. The spherical nucleus of the schizont and merozoite contains a large nucleolus. The anterior end of the merozoite has a typical conoidal complex composed of a conoid and a polar ring with 22 subpellicular mirotubules projecting from it.
New findings are a membranous septum across the body of the merozoite at 2/3 of its length below the nucleus and a highly osmiophilic spiral structure in the perinuclear space close to the Golgi complex. In addition, we found some "developmental stages" of the latter structure. 相似文献
The surface of a multinucleate schizont and that of a uninucleate merozoite is covered by a double-layered membrane. Rhoptries and micronemes are present. The cytoplasm is packed with ribosomes and also contains dark bodies. Mitochondria are of the vesicular type. The spherical nucleus of the schizont and merozoite contains a large nucleolus. The anterior end of the merozoite has a typical conoidal complex composed of a conoid and a polar ring with 22 subpellicular mirotubules projecting from it.
New findings are a membranous septum across the body of the merozoite at 2/3 of its length below the nucleus and a highly osmiophilic spiral structure in the perinuclear space close to the Golgi complex. In addition, we found some "developmental stages" of the latter structure. 相似文献
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Repeated epilation (Er) is a radiation-induced, autosomal, incomplete dominant mutation in mice which is expressed in heterozygotes but is lethal in the homozygous condition. Many effects of the mutation occur in skin: the epidermis in Er/Er mice is adhesive (oral and nasal orifices fuse, limbs adhere to the body wall), hyperplastic, and fails to undergo terminal differentiation. Skin from fetal +/+, Er/+ and Er/Er mice at ages pre- and postkeratinization examined by light, scanning, and transmission electron microscopy showed marked abnormalities in tissue architecture, differentiation, and cell structure; light and dark basal epidermal cells were separated by wide intercellular spaces, joined by few desmosomes, and contained phagolysomes. The numbers of spinous, granular, and superficial layers were highly variable within any given region and among various regions of the body. In some areas, 2-8 layers of granular cells, containing large or diminutive keratohyalin granules, extended to the epidermal surface; in others, the granular layers were covered by several layers of partially keratinized or nonkeratinized cells. In rare instances, a single or small group of cornified cells was present among the granular layers but was not associated with the epidermal surface. Both the granular and nonkeratinized/partially keratinized upper epidermal layers Er/Er skin gave positive immunofluorescence with antiserum to the histidine-rich, basic protein, filaggrin. Proteins in epidermal extracts from +/+, Er/+ and Er/Er mice were separated and identified by radio- and immunolabeling techniques. The Er/Er extract was missing a 26.5- kdalton protein and had an altered ratio of bands in the keratin region. The 26.5-kdalton band was histidine-rich and cross-reacted with the antiserum to rat filaggrin. Several high molecular weight bands present in both Er/Er and +/+ extracts also reacted with the antiserum. These are presumed to be the precursors of filaggrin and to account for the immunofluorescence om Er/Er epidermis even though the product protein is absent. The morphologic and biochemical data indicated that the genetic defect has a general and profound influence on epidermal differentiation, including alteration of two proteins (filaggrin and keratin) important in normal terminal differentiation, tissue architecture, and cytology. Identification of epidermal abnormalities at early stages of development (prekeratinization) and defective structure of other tissues and gross anatomy suggest that the mutation is responsible for a defect in same regulatory step important in many processes of differentiation and development. 相似文献
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