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81.
82.
This paper reports on an antimicrobial finishing for polyamide with high washfastness. As antimicrobial agent modified silica sols containing silver components are used as coating agent and are applied to the polyamide fabric by using a semi-industrial procedure. The antimicrobial properties of coated polyamide fabrics are determined against the bacteria E. coli. Significant antimicrobial effects are observed even after 40 washing cycles. The amount of silver on the polyamide fabrics was measured by using ICP-OES. Besides this, samples are investigated by means of UV/Vis-spectroscopy and scanning electron microscopy. Furthermore textile properties as, e.g., air permeability and mechanical properties were measured. Due to high antimicrobial effect and the strong washfastness of this finishing, this reported method could be of high interest for industrial production processes. 相似文献
83.
Boris Schröder 《植物养料与土壤学杂志》2008,171(3):325-337
84.
85.
Boris Zeide 《Forest Ecology and Management》1985,11(3):225-229
A method is described to identify canopy trees which significantly affect regeneration at a given point, estimate the effect of these trees on the growth and survival of seedlings, and determine the maximum density of the canopy trees compatible with successful regeneration. All this information is obtained using point sampling done with several basal area factors from the same point. An example of the method's application is provided. 相似文献
86.
Ultrastructural characteristics of progenetic and monoxenic Archigetes sieboldi Leuckart, 1878 from the oligochaete Limnodrilus hoffmeisteri Claparède are described. Our observations demonstrate that progenetic Archigetes sieboldi shares characteristics of both larval (progenetic) and adult stages. The primary larval characteristics are: the presence of a cercomer; a surface filamentous coat covering the whole worm; the presence of the penetration glands and the absence of tegumental ones; wide sarcoplasmic processes connecting the circular and longitudinal external tegumental muscles; the absence of the dense homogenous zone of the basal lamina beneath the epithelial cytoplasm of all reproductive organs and ducts; non-functional gonopores; and an orthogonal plan of nervous system with three pairs of longitudinal nerve trunks. The principle adult characteristics are: oogenesis, spermiogenesis and vitellogenesis that produce fertilized eggs; the uterine glands; a well-developed longitudinal tegumental muscle layer between tegumental cytons; and the presence of different microtriches. As a result of this progenetic development there has been a secondary reduction in the life cycle of A. sieboldi. It is postulated that a similar process of progenesis may have played a major role in the early evolution of the Caryophyllidea by first appearing in a plerocercoid stage of an ancestral strobilate cestode from fish. 相似文献
87.
Boris R. KRASNOV Elena N. SURKOVA Georgy I. SHENBROT Irina S. KHOKHLOVA 《Integrative zoology》2023,18(3):414-426
We tested for the effects of latitude and geographic range size (GRS) on body size, leg length, and sexual size dimorphism (SSD) across 103 species of fleas, taking into account phylogenetic between-species relationships. When the data on body size were combined for males and females, the positive correlation between body size and latitude, but not GRS, was revealed. When the analysis was restricted to one sex only, the effect of latitude appeared to be non-significant for females, whereas male body size increased with an increase in latitude. Intraspecific body size variation was not associated with either the latitude or the latitudinal span of the geographic range, independently of which data subset was analyzed. No evidence of association between size-independent tibia length and latitude was found for either females, males, or both sexes combined. The degree of SSD decreased with a decrease in latitude but was not affected by GRS. We conclude that macroecological patterns might be manifested differently in males and females. This should be kept in mind while searching for these patterns. 相似文献
88.
Boris Adrien De Lapeyre Andreas Muller‐Belecke Gabriele Horstgen‐Schwark 《Aquaculture Research》2010,41(10):e561-e567
This study was conducted to evaluate the effects of stocking density and photoperiod in increasing the reproductive performance of Oreochromis niloticus. In experiment 1, a change in stocking density (from 47.7 to 6.8 kg m?3) was performed, with groups of 48 females moved to single compartments. In experiment 2, 36 females experienced a 6L:18D photoperiod for 21 or 28 days (stocking density: 31.3 kg m?3) before being placed in individual compartments (stocking density of 6.9 kg m?3, 12L:12D photoperiod). The spawning rates in experiment 1 (32.2%) and in experiment 2 (21 days: 65.2%, 28 days: 36.1%) were significantly higher than those in the control (17.7%). On the other hand, hatching and swim‐up fry rates were significantly lower in experiment 2 – 21 days (41.3%, 40.4%) but not in experiment 1 (64.0%, 56.3%) compared with the control (67.0%, 62.3%). The spawning rate in experiment 2 – 21‐day treatment group was the highest, while the number of eggs collected per female was significantly lower than that in the control. In experiments 1 (20.8%) and 2 (21 days: 44.4%, 28 days: 19.4%), the daily spawning rates were the highest 3 days after maintaining females in single compartments. The current experiment demonstrates how specific stocking density changes can be used to induce higher spawning rates in Nile tilapia. 相似文献
89.
In this study, a dynamic model is applied to giant barnacle (Austromegabalanus psittacus) spat collection from artificial substrates located in the wild. Semi-industrial culture of the giant barnacle, A. psittacus “picoroco” in southern Chile is an interesting option for aquaculture diversification. The model establishes relationships
between variables and carries out simulations to determine their effects on spat provision. The dynamic hypothesis proposes
that the number of giant barnacle spat obtained from the wild is influenced by competent larval abundance (cyprids) over time,
substrate availability and mortality after larval settlement. In the conceptual model, 15 variables were selected and related,
establishing the polarities of each causal relationship and of each feedback loop. The Stock & Flow diagram was undertaken
using STELLA 9.0 simulation software. Simulation tests were carried out to establish the consistency of the model using the
empirical background obtained from semi-industrial cultures in southern Chile. The model establishes relative quantity of
competent larvae, substrate area and the number of spat, as key variables. Synchrony between level of cyprid abundance and
location of artificial substrates in the water is critical to achieve maximum collector efficiency. A difference of less than
1 week out of synchronization produces significant losses (60–70%) in spat production. When the deployment of collectors and
maximum quantity of competent larvae are synchronized, sensitivity analysis establishes an increase of up to 49.4% in the
number of spat, as a result of the collector area released by spat early mortality. The application of dynamic models in aquaculture
constitutes a useful tool for optimizing the process. The model proposed enables us to understand the processes associated
with obtaining seed from the environment and can be applied to other similar processes, such as mytilid cultures. 相似文献
90.
Baum JK Myers RA Kehler DG Worm B Harley SJ Doherty PA 《Science (New York, N.Y.)》2003,299(5605):389-392
Overexploitation threatens the future of many large vertebrates. In the ocean, tunas and sea turtles are current conservation concerns because of this intense pressure. The status of most shark species, in contrast, remains uncertain. Using the largest data set in the Northwest Atlantic, we show rapid large declines in large coastal and oceanic shark populations. Scalloped hammerhead, white, and thresher sharks are each estimated to have declined by over 75% in the past 15 years. Closed-area models highlight priority areas for shark conservation, and the need to consider effort reallocation and site selection if marine reserves are to benefit multiple threatened species. 相似文献