1,932 research outputs found
On the Ethical Significance of Ecological Restoration: Domination or Collaboration?
Ecological restoration is essential both to a sustainable human culture and to the well being of the more-than-human world. Yet some philosophers criticize enthusiasm for restoration as yet another manifestation of human domination and anthropocentric arrogance. The paper critiques this view as persistently presented by Eric Katz, and offers an alternative view of restoration’s ethical significance. Rather than seeing restoration as a unilateral human imposition on nature, restoration deserves defense as an expression of an interspecies etiquette, attentive to collaboration with the more-than-human world. But the full ethical significance of ecological restoration will not be realized without deep change in the surrounding culture
The endocytic pathways of Dictyostelium discoideum
The formation and processing of vesicles from the cell surface serves many important cellular functions ranging from nutrient acquisition to regulating the turnover of membrane components and signalling. In this article, we summarise the endocytic pathways of the social amoeba Dictyostelium from the clathrin-dependent and independent internalisation of surface components to the engulfment of bacteria or fluid by phagocytosis and macropinocytosis respectively. Due to similarities with the professional phagocytes of the mammalian immune system Dictyostelium has been extensively used to investigate the complex remodelling and trafficking events that occur as phagosomes and macropinosomes transit through the cell. Here we discuss what is known about this maturation process in order to kill any potential pathogens and obtain nutrients for growth. Finally, we aim to put these studies in evolutionary context and highlight some of the many questions that remain in our understanding of these complex and important pathways
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Agricultural development prospects in Belize (NRI Bulletin 48)
This report is one ofthree documents completing the land resource assessment of Belize undertaken by the Natural Resources Institute (NRI)from 1986-90. The other documents are: (i) a revised national soil classification (Baillie et al., 1993) (ii) an update on 'Land in British Honduras' (Wright et al., 1959), which will present inter alia much of the NRI land resource assessment findings in a more easily readable format (Wright et al., 1993). The aim of this report is to assess the entire··agricultural resources of the country, present an assessment of how they can be used to best effect, both in the short(economically) and long terms (by protecting the environment), and present a 1:500 000 scale map indicating the preferred use for each part of the country (Map 1 ). Map 1 does not take into account current ownership, except in the case of Programme for Belize, where it is assumed that organization will continue to manage the Rio Bravo Conservation Management Area. This report also includes advice on how a Geographical Information System (GIS) can be used to update the NRI surveys and provide additional data so that the suitability of new crops and the effect of changed economic circumstances can be determined from the land resource assessment database
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Land resource assessment of Northern Belize (NRI Bulletin 43, Volume 1 of 2)
The land resource assessment was undertaken from July 1989 to June 1990 by the Natural Resources Institute (NRI) of the Overseas Development Administration (ODA), assisted by Mr. A. C. S. Wright, and Dr. M. Holder of Central Farm. The main object of the survey was to produce an updated land suitability assessment of Orange Walk, Corozal, Belize and Cayo districts which had not already been surveyed by Jenkin et al. (1976) and King et al. (1989). In addition, this survey would provide a land suitability assessment for the Belize Valley based on the soil mapping of )en kin et al. Thus, together with the land resource assessments of Toledo and Stann Creek districts (King et al., 1986, 1989 respectively), a land suitability assessment for the whole of Belize is now available
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Land resource assessment of Northern Belize (NRI Bulletin 43, Volume 2 of 2)
The land resource assessment was undertaken from July 1989 to June 1990 by the Natural Resources Institute (NRI) of the Overseas Development Administration (ODA), assisted by Mr. A. C. S. Wright, and Dr. M. Holder of Central Farm. The main object of the survey was to produce an updated land suitability assessment of Orange Walk, Corozal, Belize and Cayo districts which had not already been surveyed by Jenkin et al. (1976) and King et al. (1989). In addition, this survey would provide a land suitability assessment for the Belize Valley based on the soil mapping of )en kin et al. Thus, together with the land resource assessments of Toledo and Stann Creek districts (King et al., 1986, 1989 respectively), a land suitability assessment for the whole of Belize is now available
Comparative analysis of full genomic sequences among different genotypes of dengue virus type 3
<p>Abstract</p> <p>Background</p> <p>Although the previous study demonstrated the envelope protein of dengue viruses is under purifying selection pressure, little is known about the genetic differences of full-length viral genomes of DENV-3. In our study, complete genomic sequencing of DENV-3 strains collected from different geographical locations and isolation years were determined and the sequence diversity as well as selection pressure sites in the DENV genome other than within the E gene were also analyzed.</p> <p>Results</p> <p>Using maximum likelihood and Bayesian approaches, our phylogenetic analysis revealed that the Taiwan's indigenous DENV-3 isolated from 1994 and 1998 dengue/DHF epidemics and one 1999 sporadic case were of the three different genotypes – I, II, and III, each associated with DENV-3 circulating in Indonesia, Thailand and Sri Lanka, respectively. Sequence diversity and selection pressure of different genomic regions among DENV-3 different genotypes was further examined to understand the global DENV-3 evolution. The highest nucleotide sequence diversity among the fully sequenced DENV-3 strains was found in the nonstructural protein 2A (mean ± SD: 5.84 ± 0.54) and envelope protein gene regions (mean ± SD: 5.04 ± 0.32). Further analysis found that positive selection pressure of DENV-3 may occur in the non-structural protein 1 gene region and the positive selection site was detected at position 178 of the NS1 gene.</p> <p>Conclusion</p> <p>Our study confirmed that the envelope protein is under purifying selection pressure although it presented higher sequence diversity. The detection of positive selection pressure in the non-structural protein along genotype II indicated that DENV-3 originated from Southeast Asia needs to monitor the emergence of DENV strains with epidemic potential for better epidemic prevention and vaccine development.</p
Soil and Nutrient Losses from Small Sprinkler and Furrow Irrigated Watersheds in Southern Idaho
Sediment and associated nutrients flowing to the Snake River with furrow irrigation runoff and unused irrigation water have been a concern in the Twin Falls irrigation tract in southern Idaho. Converting furrow irrigated fields to sprinkler irrigation is one practice that has been promoted, and received financial assistance, to reduce sediment loss. Five small watersheds (330 to 1480 acres) with 10 to 70% sprinkler irrigation were monitored from 2005 to 2008 to determine if converting to sprinkler irrigation reduced sediment and nutrient losses from these watersheds. Eliminating runoff from furrow irrigated fields by converting to sprinkler irrigation will reduce sediment and nutrient losses from fields. However, there were no significant correlations between the amount of sprinkler irrigation and the sediment or nutrient loads from these watersheds. Potential reasons for these results are the flow rate allocation system used by the TFCC, the amount and location of furrow irrigated fields in each watershed, and the management of furrow irrigated fields within each watershed. One significant correlation was decreasing dissolved phosphorus concentrations as relative amount of sprinkler irrigated land increased, presumably because less water flowed across fields in furrows as sprinkler irrigated area increased. A water quality model for irrigated watersheds is needed for more thorough assessment of the variety conditions and management practices within these watersheds
An assessment of the strength of knots and splices used as eye terminations in a sailing environment
Research into knots, splices and other methods of forming an eye termination has been limited, despite the fact that they are essential and strongly affect the performance of a rope. The aim of this study was to carry out a comprehensive initial assessment of the breaking strength of eye terminations commonly used in a sailing environment, thereby providing direction for further work in the field. Supports for use in a regular tensile testing machine were specially developed to allow individual testing of each sample and a realistic spread of statistical data to be obtained. Over 180 break tests were carried out on four knots (the bowline, double bowline, figure-of-eight loop and perfection loop) and two splices (three-strand eye splice and braid-on-braid splice). The factors affecting their strength were investigated. A statistical approach to the analysis of the results was adopted. The type of knot was found to have a significant effect on the strength. This same effect was seen in both types of rope construction (three-strand and braid-on-braid). Conclusions were also drawn as to the effect of splice length, eye size, manufacturer and rope diameter on the breaking strength of splices. Areas of development and further investigation were identified
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