494 research outputs found
Transmission Oscillator Ultrasonic Spectrometer (TOUS): A new research instrument
TOUS is capable for measuring very small changes in acoustic attenuation and phase velocity. Its high sensitivity to small changes in ultrasonic absorption results in part from operation under marginal conditions. In spite of high sensitivity, TOUS system is relatively simple, inexpensive, and compact
The white-fly of greenhouses, Bulletin, no. 100
The Bulletin is a publication of the New Hampshire Agricultural Experiment Station, College of Life Sciences and Agriculture, University of New Hampshire, Durham, New Hampshire
An operational definition of the biome for global change research
CITATION: Conradi, T. et al. 2020. An operational definition of the biome for global change research. New Phytologist, 227:1294–1306, doi:10.1111/nph.16580.The original publication is available at https://nph.onlinelibrary.wiley.comBiomes are constructs for organising knowledge on the structure and functioning of the world’s ecosystems, and serve as useful units for monitoring how the biosphere responds to anthropogenic drivers, including climate change. The current practice of delimiting biomes relies on expert knowledge. Recent studies have questioned the value of such biome maps for comparative ecology and global-change research, partly due to their subjective origin. Here we propose a flexible method for developing biome maps objectively. The method uses range modelling of several thousands of plant species to reveal spatial attractors for different growth-form assemblages that define biomes. The workflow is illustrated using distribution data from 23 500 African plant species. In an example application, we create a biome map for Africa and use the fitted species models to project biome shifts. In a second example, we map gradients of growth-form suitability that can be used to identify sites for comparative ecology. This method provides a flexible framework that (1) allows a range of biome types to be defined according to user needs and (2) enables projections of biome changes that emerge purely from the individualistic responses of plant species to environmental changes.Publisher's versio
Boolean Models of Bistable Biological Systems
This paper presents an algorithm for approximating certain types of dynamical
systems given by a system of ordinary delay differential equations by a Boolean
network model. Often Boolean models are much simpler to understand than complex
differential equations models. The motivation for this work comes from
mathematical systems biology. While Boolean mechanisms do not provide
information about exact concentration rates or time scales, they are often
sufficient to capture steady states and other key dynamics. Due to their
intuitive nature, such models are very appealing to researchers in the life
sciences. This paper is focused on dynamical systems that exhibit bistability
and are desc ribedby delay equations. It is shown that if a certain motif
including a feedback loop is present in the wiring diagram of the system, the
Boolean model captures the bistability of molecular switches. The method is
appl ied to two examples from biology, the lac operon and the phage lambda
lysis/lysogeny switch
Quantum Cosmology of Kantowski-Sachs like Models
The Wheeler-DeWitt equation for a class of Kantowski-Sachs like models is
completely solved. The generalized models include the Kantowski-Sachs model
with cosmological constant and pressureless dust. Likewise contained is a
joined model which consists of a Kantowski-Sachs cylinder inserted between two
FRW half--spheres. The (second order) WKB approximation is exact for the wave
functions of the complete set and this facilitates the product structure of the
wave function for the joined model. In spite of the product structure the wave
function can not be interpreted as admitting no correlations between the
different regions. This problem is due to the joining procedure and may
therefore be present for all joined models. Finally, the {s}ymmetric {i}nitial
{c}ondition (SIC) for the wave function is analyzed and compared with the ``no
bouindary'' condition. The consequences of the different boundary conditions
for the arrow of time are briefly mentioned.Comment: 21 pages, uses LaTeX2e, epsf.sty and float.sty, three figures (50
kb); changes: one figure added, new interpretation of quantizing procedure
for the joined model and many minor change
Guidance on global interprofessional education and collaborative practice research : discussion paper
Transcripts coding the VWF cleaving protease are decreased under proinflammatory conditions, which is reversed by co-incubation with activated protein C and selenate
In search of the origins and enduring impact of agile software development
The Agile Manifesto is a philosophical touchpoint for all agile
software development (ASD) methods. We examine the manifesto
and some of its associated agile methods in an effort to identify
the major impacts of ASD. We have encountered some difficulty
in delineating agile and non-agile software processes, which is
partially the result of terminological confusion. It is clear from the
volume of published research that ASD has made a significant
contribution, and we have identified two lasting and important
impacts. Firstly, the reduction in iteration durations and secondly,
the push for reduced levels of documentation (especially in
relation to software requirements). Other aspects of the Agile
Manifesto may not have exerted a significant impact; for example,
the use of tooling to automate processes has become central to
continuous software engineering (CSE) and may not be wholly
congruent with the manifesto. Furthermore, many organisations
may still rely on business contracts despite calls in the manifesto
for greater levels of informal customer collaboration
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