Posts Tagged ‘analysis’
Replication Versus Realism: The Need for Ecosystem-Scale Experiments
David W. Schindler
ABSTRACT
The results of bottle and mesocosm experiments
were compared with those obtained in whole-
ecosystem experiments at the Experimental Lakes
Area. Unless they can be cleverly designed to mimic
major ecosystem processes and community compo-
sitions, smaller-scale experiments often give highly
replicable, but spurious, answers. Problems with
appropriate scaling are difficult to deduce without
direct comparisons with whole-ecosystem experi-
ments. Reasons aremany, but include inappropriate
spatial scales to include whole communities, in
particular predators and nocturnally active animals;
temporal scales that are too short to assess accu-
rately the response of slow-responding organisms
and biogeochemical processes; and elimination of
key littoral–pelagic and catchment–lake interac-
tions. Identical studies of limnological processes in
lakes of a large …
Do Forests Receive Occult Inputs of Nitrogen?
Dan Binkley,
Yowhan Son,
and David W. Valentine
ABSTRACT
The nitrogen (N) cycle of forest ecosystems is un-
derstood relatively well, and few scientists expect
that major revisions will be necessary; most current
work on N cycling focuses on improving the preci-
sion estimates of pools and fluxes, or measuring the
magnitudes of well-known pools in response to
management or disturbances. However, in the past
few decades more than a dozen articles in refereed
journals have claimed very high rates of N input, far
beyond the rates expected for known sources of N.
In this review, we summarize the literature on N
accretion rates in forests that lack substantial con-
tributions from symbiotic N-fixing plants. We …
Energetic Basis for of Ecosystem Services Valuation
Howard T. Odum
and Eugene P. Odum
Valuation is one mechanism by which humans
organize occupancy and use of large-scale ecosys-
tems and regions, such as watersheds, estuaries,
cities, states, nations, and ultimately the whole
earth (the global perspective). When human valua-
tions do not measure the real contributions of
natural ecosystems, as is currently the case, ecosys-
tems are not protected, and the larger systems
produce less when the natural ecosystems are lost to
development. Ecologists working on small-scale
studies are concerned with the loss of their study
areas and biodiversity. Ecologists working at large
scales, and society in general, have to be concerned
that poor valuation is delaying the organization of a
sustainable pattern …
Valuation of Ecosystem Services in Institutional Context
Lowell Pritchard Jr.,
Carl Folke,
and Lance Gunderson
INTRODUCTION
As long as we are forced to make choices, we are
doing valuation. But different approaches to valua-
tion are based on qualitatively different assump-
tions. For example, the economics approach to
valuation is based on the ethical principle of con-
sumer sovereignty, and it privileges the kinds of
decisions individuals make in the marketplace. We
accept the economics approach as a useful partial
approach to decision making in relation to ecosys-
temservices if one is interested in what people think
about and want from services; if one believes that
human preferences are the basis for the value of
services; if one accepts the assumption that adding
individual …
Effects of Mismatch Strain and Alloy Composition on the Formation of InAs Islands on InAlAs Templates
Y. CORDIER,
1,3 P. MISKA,
1 and D. FERRE2
1.—Institut d’Electronique et de Microélectronique du Nord, U.M.R.-C.N.R.S 8520,
Avenue Poincaré, Université de Lille 1, BP 69, 59652 Villeneuve d’Ascq Cedex, France.
2.—Laboratoire Structure et Propriétés de l’Etat Solide, URA 234, Université de Lille 1,
59650 Villeneuve d’Ascq, France. 3.—e-mail: yvon.cordier@iemn.univ-lille1.fr
InAs islands self-assembled on InAlAs layers lattice mismatched on GaAs
substrates have been grown by molecular beam epitaxy. Both pseudomorphic
and metamorphic InAlAs buffer layers were used as a template to investigate the
effects of strain relaxation on the formation of the islands. The effect of alloy
composition in the metamorphic templates is shown on the density and the shape
of …
eLearning Critical Analysis
Over recent years, we’ve been increasingly amazed by technology that provides us with easier ways of accomplishing many things. Doing business, shopping, researching, holding meetings, dating and keeping in touch with our distant friends can now all be done electronically.
Elearning is one of these technological advances that allows us to learn anywhere anytime. Elearning institutions afford us professional instructors and comprehensive online courses over the Internet and can be taken up by using a single computer. These new learning opportunities were brought in by thoughtful people committed in making life easier.
However, there are people who are critical of elearning …
eLearning Companies
Elearning companies can provide you services and assistance to your elearning institution to accomplish your business objectives. Their job is to assist you in your leadership, organizational, human capital development and success strategies, and offer coaching and mentoring services and management solutions.
The services that these companies offer are unique in themselves because they serve you in line with their fields of specialization. Thus, some or most of them may include strategic planning for training and associated consultancy services that help you in needs assessment and analysis of your objectives.
They may also afford web-based learning programs and content management, corporate …
The automation of Science
Ross D. King,
Jem Rowland,
Stephen G. Oliver,
Michael Young,
Wayne Aubrey,
Emma Byrne,
Maria Liakata,
Magdalena Markham,
Pınar Pir,
Larisa N. Soldatova,
Andrew Sparkes,
Kenneth E. Whelan,
Amanda Clare
The basis of science is the hypothetico-deductive method and the recording of experiments in
sufficient detail to enable reproducibility. We report the development of Robot Scientist “Adam,”
which advances the automation of both. Adam has autonomously generated functional genomics
hypotheses about the yeast Saccharomyces cerevisiae and experimentally tested these hypotheses
by using laboratory automation. We have confirmed Adam’s conclusions through manual
experiments. To describe Adam’s research, we have developed an ontology and logical language.
The resulting formalization involves over 10,000 different research units in a nested treelike
structure, 10 levels …
Al2O3 Physical properties
W. Y. Ching,
Lizhi Ouyang,
Paul Rulis,
and Hongzhi Yao1
Department of Physics, University of Missouri-Kansas City, Kansas City, Missouri 64110, USA
Department of Physics and Mathematics, Tennessee State University, Nashville, Tennessee 37211, USA
Based on the most recently determined noncubic structure for -Al2O3 by Menendez-Proupin and Gutierrez,
a comprehensive list of physical properties is investigated theoretically. These include lattice dynamics and
phonon spectra, elastic constants and bulk structural parameters, electronic structure and interatomic bonding,
optical properties, and x-ray absorption near-edge structure XANES spectra. Compared to similar calcula-
tions of -Al2O3, we find a smaller lowest zone-center vibrational mode at 97.6 cm−1
, a lower heat capacity,
a smaller bulk modulus, and …