共查询到20条相似文献,搜索用时 15 毫秒
1.
Using BEES to select cost-effective green products 总被引:1,自引:0,他引:1
Barbara C. Lippiatt Amy S. Boyles 《The International Journal of Life Cycle Assessment》2001,6(2):76-80
The BEES (Building for Environmental and Economic Sustainability) software brings to your fingertips a powerful technique
for balancing the environmental and economic performance of building products. The tool is based on consensus standards and
designed to be practical, flexible, and transparent. Version 2.0 of the Windows™-based decision support software, aimed at
designers, builders, and product manufacturers, includes actual environmental and economic performance data for 65 building
products. The purpose is to support purchasing decisions by providing key science-based information often lacking in ‘green’
product selection. The intended result is a cost-effective reduction in building-related contributions to environmental problems.
Contribution of the National Institute of Standards and Technology (NIST) and not subject to copyright in the United States.
NIST does not endorse any particular brand, product, or service. 相似文献
2.
Harold White 《Bulletin of mathematical biology》1962,24(4):351-359
Quantitative aspects of the photochemistry of visual adaptation are considered. A simplied model is given that fits data on
changes of rhodopsin concentration during and following strong illumination. A variation on Wald’s compartment hypothesis
is shown to fit the quasilinear dependence of log threshold upon pigment concentration. Finally, there is a brief review of
pertinent data on cone pigments.
This research was supported in part by the United States Air Force through the Air Force Office of Scientific Research of
the Air Research Development Command under Contract No. AF(638)-414, and in part by the United States Public Health Service
Training Grant 2G-833. 相似文献
3.
The Ecology of Infectious Diseases (EID) program is a joint National Science Foundation–National Institutes of Health initiative
to produce predictive understanding of disease dynamics, with a focus on diseases with an environmental component. The interdisciplinary
research projects funded by this program take advantage of the wide range of theoretical and methodological advances developed
over the past 30 years. The challenge for disease ecology is to unravel these systems, discover how complex they truly are,
and to determine if they can be predicted and controlled using targeted environmental, public health, or medical interventions.
Between 1999 and 2005, a total of 42 research awards were made under the EID program. EID projects have had affects on policy
in two areas: adoption of novel interventions on a local scale and use of models by government agencies for the purpose of
allocating public health resources. The past 6 years have been an exciting time for the field of disease ecology; we expect
the coming years to be even more exciting and productive.
As US federal government employees writing an article as part of our official duties, copyright of all publications is retained
by the US government.
The views expressed here by Samuel M. Scheiner and Joshua P. Rosenthal are those of the authors and do not represent official
views or policies of the National Science Foundation, the National Institutes of Health, or the United States Government. 相似文献
4.
Evolutionary trees from DNA sequences: A maximum likelihood approach 总被引:129,自引:0,他引:129
Joseph Felsenstein 《Journal of molecular evolution》1981,17(6):368-376
Summary The application of maximum likelihood techniques to the estimation of evolutionary trees from nucleic acid sequence data is discussed. A computationally feasible method for finding such maximum likelihood estimates is developed, and a computer program is available. This method has advantages over the traditional parsimony algorithms, which can give misleading results if rates of evolution differ in different lineages. It also allows the testing of hypotheses about the constancy of evolutionary rates by likelihood ratio tests, and gives rough indication of the error of the estimate of the tree.By acceptance of this article, the publisher and/or recipient acknowledges the U.S. government's right to retain a nonexclusive, royalty-free licence in and to any copyright covering this paperThis report was prepared as an account of work sponsored by the United States Government. Neither the United States nor the United States Department of Energy, nor any of their employees, nor any of their contractors, subcontractors, or their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness or usefulness of any information, apparatus, product or process disclosed, or represents that its use would not infringe privately-owned rights 相似文献
5.
Distal embolization of particulate matter complicates percutaneous coronary and peripheral interventions more often than had been recognized until recently. A number of distal protection devices are under development. The PercuSurge GuardWire™ is a balloon occlusion thrombectomy device approved by the United States Food and Drug Administration for saphenous vein graft intervention. A number of filter devices utilize an expandable filter mounted on the angioplasty guidewire to facilitate entrapment of particles and safe removal. The Parodi Anti-Emboli System™ is an example of a catheter occlusion device that establishes protection by reversing blood flow in the target vessel. 相似文献
6.
Garland E. Allen 《Genetica》1997,99(2-3):77-88
Eugenics, the attempt to improve the genetic quality of the human species by ‘better breeding’, developed as a worldwide movement
between 1900 and 1940. It was particularly prominent in the United States, Britain and Germany, and in those countries was
based on the then-new science of Mendelian genetics. Eugenicists developed research programs to determine the degree to which
traits such as Huntington's chorea, blindness, deafness, mental retardation (feeblemindedness), intelligence, alcoholism,
szhiophrenia, manic depression, rebelliousness, nomadism, prostitution and feeble-inhibition were genetically determined.
Eugenicists were also active in the political arena, lobbying in the United States for immigration restriction and compulsory
sterilization laws for those deemed genetically unfit; in Britain they lobbied for incarceration of genetically unfit and
in Germany for sterilization and eventually euthanasia. In all these countries one of the major arguments was that of efficiency:
that it was inefficient to allow genetic defects to be multiplied and then have to try and deal with the consequences of state
care for the offspring. National Socialists called genetically defective individuals ‘useless eaters’ and argued for sterilization
or euthanasia on economic grounds. Similar arguments appeared in the United States and Britain as well. At the present time
(1997) much research and publicity is being given to claims about a genetic basis for all the same behaviors (alcoholism,
manic depression, etc), again in an economic context – care for people with such diseases is costing too much. There is an
important lesson to learn from the past: genetic arguments are put forward to mask the true – social and economic – causes
of human behavioral defects.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
7.
Robert Rosen 《Bulletin of mathematical biology》1962,24(3):279-290
It is shown informally that Cohn’s theory of Optimal Forms can be construed as a comparative theory, and that when this is
done the celebrated theory of transformations of D’Arcy Thompson follows as a consequence. The implications of this type of
theoretical foundation for the Thompson theory with regard to problems of comparative morphology are discussed, and some suggestions
for the further implementation of the theory are described.
This research was supported by the United States Air Force through the Air Force Office of Scientific Research of the Air
Research and Development Command, under Contract No. AF 49(638)-917. 相似文献
8.
Tubificid worms did not accumulate radionuclides bound to sediments, but did accumulate dissolved radionuclides. The level
of accumulation of dissolved 65Zn by the worms was dependent upon temperature and concentration of the radionuclide.
This paper is based on work performed under United States Atomic Energy Commission Contract AT(45-1)-1830.
This paper is based on work performed under United States Atomic Energy Commission Contract AT(45-1)-1830. 相似文献
9.
Potential Changes in Tree Species Richness and Forest Community Types following Climate Change 总被引:3,自引:0,他引:3
Potential changes in tree species richness and forest community types were evaluated for the eastern United States according
to five scenarios of future climate change resulting from a doubling of atmospheric carbon dioxide (CO2). DISTRIB, an empirical model that uses a regression tree analysis approach, was used to generate suitable habitat, or potential
future distributions, of 80 common tree species for each scenario. The model assumes that the vegetation and climate are in
equilibrium with no barriers to species migration. Combinations of the individual species model outcomes allowed estimates
of species richness (from among the 80 species) and forest type (from simple rules) for each of 2100 counties in the eastern
United States. Average species richness across all counties may increase slightly with climatic change. This increase tends
to be larger as the average temperature of the climate change scenario increases. Dramatic changes in the distribution of
potential forest types were modeled. All five scenarios project the extirpation of the spruce–fir forest types from New England.
Outputs from only the two least severe scenarios retain aspen–birch, and they are largely reduced. Maple–beech–birch also
shows a large reduction in area under all scenarios. By contrast, oak–hickory and oak–pine types were modeled to increase
by 34% and 290%, respectively, averaged over the five scenarios. Although many assumptions are made, these modeled outcomes
substantially agree with a limited number of predictions from researchers using paleoecological data or other models.
Received 12 May 2000; accepted 20 October 2000. 相似文献
10.
Robert Rosen 《Bulletin of mathematical biology》1961,23(2):165-171
It is shown that a wide variety of structural alterations in both the “metabolic” and “genetic” apparatus of (
, ℜ)-systems can result from specific changes in the environment of such systems. A number of specific examples are investigated
in order to demonstrate the scope of these alterations. Certain biological applications of this discussion are suggested,
including a suggestion for a possible interpretation of the mitotic cycle.
This research was supported by the United States Air Force through the Air Force Office of Scientific Research of the Air
Research and Development Command, under Contract #AF 49 (638)-917. 相似文献
11.
12.
In the 1950s Charles Elton hypothesized that more diverse communities should be less susceptible to invasion by exotic species
(biodiversity–invasibility hypothesis). The biodiversity–invasibility hypothesis postulates that species-rich communities
are less vulnerable to invasion because vacant niches are less common and the intensity of interspecific competition is more
severe. Field studies were conducted at two sites, a logged site and an unlogged site in Santa Rosa County, Florida, U.S.A,
to test Elton’s hypothesis using cogongrass (Imperata cylindrica), a non-indigenous grass invading large areas of the Southeastern United States. The logged site was under 17-year-old loblolly
pine prior to clear cutting. The unlogged site, a longleaf pine forest, was at the Blackwater River State Forest. Both the
logged site and unlogged site showed no significant relationship between the rate of cogongrass spread and native plant species
richness, functional richness, and cover of the invaded community. Increased species or functional richness may increase the
use of resources; however, the extensive rhizome/root network possessed by cogongrass and its ability to thrive under shade
may allow for its persistence in a diverse community. The results from both the logged and unlogged sites do not support the
general hypothesis of Elton that invasion resistance and compositional stability increase with diversity. Biodiversity does
not appear to be an important factor for cogongrass invasion in the southern United States. Extrinsic factors in this study
prevent the ability to draw a defined causal relationship between native plant diversity and invasibility. Underlying reasons
for why no relationship was observed may be simply due to the tremendous competitive ability of cogongrass or the narrow range
of species richness, functional richness and cover observed in our study. 相似文献
13.
Craig R. Allen Ahjond S. Garmestani Jill A. LaBram Amanda E. Peck Luanna B. Prevost 《Biological invasions》2006,8(2):169-176
Woodlots are forest islands embedded within an urban matrix, and often represent the only natural areas remaining in suburban
areas. Woodlots represent critical conservation areas for native plants, and are important habitat for wildlife in urban areas.
Invasion by non-indigenous (NIS) plants can alter ecological structure and function, and may be especially severe in remnant
forests where NIS propagule pressure is high. Woody shrubs in the Family Berberidaceae have been well documented as invaders
of the forest–urban matrix in North America. Mahonia bealei (Berberidaceae) is a clonal shrub native to China, and is a popular ornamental in the Southeastern United States. Mahoni bealei is listed as “present” on some local and state floras, but almost nothing is known regarding its invasion potential in the
United States. We sampled 15 woodlots in Clemson, South Carolina, to assess the invasion of M. bealei and other woody non-indigenous species (NIS). M. bealei invaded 87% of the woodlots surveyed and species richness of NIS on these woodlots varied from 5 to 14. Stepwise-multiple
regression indicated that less canopy cover and older M. bealei predicted greater abundance of M. bealei , and that not all subdivisions were equally invaded (P < 0.0001; r2 = 0.88). The impact of M. bealei on native flora and fauna may be considerable, and it is likely to continue to spread in the Southeastern United States.
M. bealei should be recognized as an aggressive invader in the Southeastern United States, with the potential for negative impacts
on native flora and fauna. 相似文献
14.
Robert Rosen 《Bulletin of mathematical biology》1963,25(1):41-50
The environmentally induced alterations in structure of (M, ℜ) which were described previously (R. Rosen,Bull. Math. Biophysics,23, 165–171, 1961) are examined from the standpoint of determining under what circumstances they can be reversed by further
environmental interactions. For simplicity we consider only the case of (M, ℜ)-systems possessing one “metabolic” and one “genetic” component. In the case of environmentally induced alteration of
the “metabolic” component alone, a necessary and sufficient condition is given for the reversibility of the alteration. In
the case of alteration of the “genetic” component, the situation becomes more complex; several partial results are given,
but a full analysis is not available at this time. Some possible biological implications of this analysis are discussed.
This research was supported by the United States Air Force through the Air Force Office of Scientific Research of the Air
Research and Development Command, under Contract no. AF-49(638)-917 and Grant no. AF-AFOSR-9-63. 相似文献
15.
Erica Caple James 《Culture, medicine and psychiatry》2009,33(1):153-159
The term ‘asylum’ has a dual connotation that generates opposing but related forms of intervention: providing sanctuary and
protection vs. imposing confinement and quarantine. The proliferation of “neomodern insecurity”—intrastate violence and the
specter of transnational terrorism, arising within many postcolonial, postauthoritarian and postsocialist states—generates
intervention practices that reflect the dual connotations of asylum. In fragile states like Haiti, national insecurity (ensekirite) often results in the flight of traumatized populations across and within national borders. For these individuals, ‘asylum’
connotes the attainment of political recognition and inclusion outside Haiti’s space of ensekirite. Ironically, these vulnerable persons may be viewed as threats to the nations they seek to enter. In so-called secure states
like the United States, the threat of insecurity often engenders interventions to contain, manage and rehabilitate states
of disorder, as well as their disordered subjects. By chronicling the case of a young Haitian refugee who sought asylum in
the United States, was detained and then repatriated after manifesting the disordered signs of insecurity, I argue that the
Haitian trope of ensekirite captures and prefigures the subjective experience of neomodernity, one for which there is no asylum. 相似文献
16.
Heinrich Kroeger 《Development genes and evolution》1959,151(2):113-135
Ohne ZusammenfassungOperated by Union Carbide Corporation for the United States Atomic Energy Commission.Appointment supported by the International Cooperation Administration under a program administered by the National Academy of Sciences of the United States. 相似文献
17.
Torbjørn Pedersen 《Ocean Development & International Law》2013,44(1-2):120-135
This article explains the position(s) of the United States in the maritime dispute adjacent to Svalbard. While the United States has regarded Norway's exclusive claim to the natural resources outside Svalbard as everything from “wishful thinking” to legally plausible, Washington maintains that it may have rights under the 1920 Svalbard Treaty to exploit the maritime zones adjacent to the archipelago. The U.S. reservation is the result of assessments and reassessments of legal considerations as well as national interests. 相似文献
18.
Electron-microscopic evidence showing the location of strontiumand calcium deposits on the lamellae of spinach chloroplastsis presented. The chloroplast limiting membrane did not actas a barrier for this ion accumulation, since the chloroplastswere ruptured during the isolation and incubation, especiallyin the light. The grana stacks also were extensively swollen.The number of electrondense deposits attached on the lamellaewas greatly increased by light under conditions favoring thehydrolysis of ATP. The average diameter of the deposits aftera 6 minute illumination with 1 mM SrCl2 was 14 mµ, after15 minutes with 1 mM SrCl2 was 21 mµ, and after 15 minuteswith 20 µM SrCl2 was 13 mµ. The findings are inharmony with the results of ion-uptake experiments using radioactivestrontium and calcium.
1 United States National Science Foundation Postdoctoral Fellow. 相似文献
19.
Bionomical and host-range studies of the lacebug,Oncochila simplex (Herrich-Shaeffer) (Hemiptera: Tingidae), a candidate for the biological control of leafy spurge (Euphorbia esula L. “complex”) in the United States, were made during the years 1979 to 1982 at the USDA-ARS Rome Laboratory, and during 1981
and 1982 at the USDA-ARS Albany, California laboratory. A total of 26 test plant species, varieties, or population was used.
Oncochila simplex overwinters as adults and nymphs at the base of its host, 4 to 5 cm below the soil surface. In the Piacenza area (northern
Italy) adults first appeared at the end of March and were present as 5 successive generations until the end of September.
In the laboratory, under long day (L: D-16: 8) conditions, reproduction was continuous, amounting to 11 generations during
1981. Each life cycle was completed in 33 to 40 days. The ♀♀ laid eggs under the mesophyll of stems. An average of 175±10.93
eggs per female were produced. Of a sample of 1,580 eggs, 83% were fertile.Oncochila simplex has 4 nymphal instars. Adults lived 50–70 days.
In no-choice tests, neonate nymphs ofO. simplex developed on plants of the genusEuphorbia (subgenusEsula) and on lettuce and corn. In field trials, this lacebug completed a generation onEuphorbia lathyris L., but not on lettuce and corn. The development of neonate nymphs under forced conditions on lettuce and corn does not necessarily
indicate that these plants are suitable hosts in nature. Our hypothesis of the restricted host range ofO. simplex is also supported by the literature, in which there are no reports of this species from lettuce, corn or other plants of
agricultural importance. We conclude thatO. simplex should be introduced as a biological control agent against leafy spurge in the United States.
相似文献
20.
Patrik Krebs Gianni B. Pezzatti Stefano Mazzoleni Lee M. Talbot Marco Conedera 《Theorie in den Biowissenschaften》2010,129(1):53-69
“Fire regime” has become, in recent decades, a key concept in many scientific domains. In spite of its wide spread use, the
concept still lacks a clear and wide established definition. Many believe that it was first discussed in a famous report on
national park management in the United States, and that it may be simply defined as a selection of a few measurable parameters
that summarize the fire occurrence patterns in an area. This view has been uncritically perpetuated in the scientific community
in the last decades. In this paper we attempt a historical reconstruction of the origin, the evolution and the current meaning
of “fire regime” as a concept. Its roots go back to the 19th century in France and to the first half of the 20th century in
French African colonies. The “fire regime” concept took time to evolve and pass from French into English usage and thus to
the whole scientific community. This coincided with a paradigm shift in the early 1960s in the United States, where a favourable
cultural, social and scientific climate led to the natural role of fires as a major disturbance in ecosystem dynamics becoming
fully acknowledged. Today the concept of “fire regime” refers to a collection of several fire-related parameters that may
be organized, assembled and used in different ways according to the needs of the users. A structure for the most relevant
categories of parameters is proposed, aiming to contribute to a unified concept of “fire regime” that can reconcile the physical
nature of fire with the socio-ecological context within which it occurs. 相似文献