1,476 research outputs found
A review of periodical literature on merit rating.
Thesis (Ed.M.)--Boston Universit
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Interrogating cellular perception and decision making with optogenetic tools.
Optogenetics promises to deepen our understanding of how cells perceive and respond to complex and dynamic signals and how this perception regulates normal and abnormal function. In this study, we present our vision for how these nascent tools may transform our view of fundamental cell biological processes
Modelling the Gross Cost of Transporting Pig Slurry to Tillage Spread Lands in a Post Transition Arrangement within the Nitrates Directive.
working paperThe context of this paper is in the phasing out of the transitional arrangement under
the Nitrates Directive. As there is relatively little grassland capable of taking
significant amounts of pig slurry available in the vicinity of the main pig production
areas, in this paper we attempt to quantify the cost of transporting this slurry to the
nearest available tillage land. The approach taken was to examine the geographic
structure underlying the pig sector in Ireland using Geographic Information Systems
(GIS) technology. The study highlighted the differential cost with, amounting to 10%
of gross margin on average and as high in major pig producing areas as 21.5% in
Longford and 16.6% in Cavan, while lower at 7-9% in South Tipperary and Cork.
Thus while the problem is significant, the impact is not constant across the country,
highlighting the value of a spatial analytical approach. Future work should assess the
existing cost of spreading manure in order to be able to ascertain the net cost of
spreading on tillage lands. The robustness of the results also need to be tested to
assess the implications of changes in the prices of fossil fuels and fertilisers, both in
terms of the cost function and in terms of the cost of substitutable mineral fertilise
Analysis of repeated high-intensity running performance in professional soccer
The aims of this study conducted in a professional soccer team were two-fold: to characterise repeated high-intensity movement activity profiles in official match-play; b) to inform and verify the construct validity of tests commonly used to determine repeated-sprint ability in soccer by investigating the relationship between the results from a test of repeated-sprint ability and repeated high-intensity performance in competition. High-intensity running performance (movement at velocities >19.8 km/h for a minimum of 1-s duration) in 20 players was measured using computerised time motion analysis. Performance in 80 French League 1 matches was analysed. In addition, 12 out of the 20 players performed a repeated-sprint test on a non-motorized treadmill consisting of 6 consecutive 6s sprints separated by 20s passive recovery intervals. In all players, the majority of consecutive high-intensity actions in competition were performed after recovery durations ≥61s, recovery activity separating these efforts was generally active in nature with the major part of this spent walking, and players performed 1.1±1.1 repeated high-intensity bouts (a minimum of 3 consecutive high-intensity with a mean recovery time ≤20s separating efforts) per game. Players reporting lowest performance decrements in the repeated-sprint ability test performed more high-intensity actions interspersed by short recovery times (≤20s, p<0.01 and ≤30s, p<0.05) compared to those with higher decrements. Across positional roles, central-midfielders performed a greater number of high-intensity actions separated by short recovery times (≤20s) and spent a larger proportion of time running at higher intensities during recovery periods while fullbacks performed the most repeated high-intensity bouts (statistical differences across positional roles from p<0.05 to p<0.001). These findings have implications for repeated high-intensity testing and physical conditioning regimens
Searching for Serendipitous Analogies
Analogical reasoning is an acknowledged process
behind many episodes of creativity. Typically, the creator chances
upon information unrelated to the given problem – and solves the
problem by analogy with this accidental source of inspiration.
Current models of analogical retrieval do not explain how
semantically unrelated source domains are retrieved. We present
the RADAR algorithm that maps domains into a separate structure
space, where domains with similar topological attributes are colocated.
Each axis in structure space records the occurrence
frequency of that feature in each domain. Nearest neighbour
retrieval in structure space identifies structurally similar domains -
from a diversity of semantic backgrounds. Structure based retrieval
opens the possibility for creating an analogy model with far greater
creativity potential than human reasoning
Features of Structure for Anaology Retrieval
Spontaneously retrieving analogies from
presented problem data is an important phase of
analogical reasoning, influencing many related
cognitive processes. Existing models have
focused on semantic similarity, but structural
similarity is also a necessary requirement of any
analogical comparison. We present a new
technique for performing structure based analogy
retrieval. This is founded upon derived attributes
that explicitly encode elementary structural
qualities of a domains representation. Crucially,
these attributes are unrelated to the semantic
content of the domain information, and encode
only its structural qualities. We describe a
number of derived attributes and detail the
computation of the corresponding attribute
values. We examine our models operation,
detailing how it retrieves both semantically
related and unrelated domains. We also present a
comparison of our algorithms performance with
existing models, using a structure rich but
semantically impoverished domai
Simultaneous X-ray/optical observations of GX 9+9 (4U 1728-16)
We report on the results of the first simultaneous X-ray (RXTE) and optical
(SAAO) observations of the luminous low mass X-ray binary (LMXB) GX 9+9 in 1999
August. The high-speed optical photometry revealed an orbital period of 4.1958
hr and confirmed previous observations, but with greater precision. No X-ray
modulation was found at the orbital period. On shorter timescales, a possible
1.4-hr variability was found in the optical light curves which might be related
to the mHz quasi-periodic oscillations seen in other LMXBs. We do not find any
significant X-ray/optical correlation in the light curves. In X-rays, the
colour-colour diagram and hardness-intensity diagram indicate that the source
shows characteristics of an atoll source in the upper banana state, with a
correlation between intensity and spectral hardness. Time-resolved X-ray
spectroscopy suggests that two-component spectral models give a reasonable fit
to the X-ray emission. Such models consist of a blackbody component which can
be interpreted as the emission from an optically thick accretion disc or an
optically thick boundary layer, and a hard Comptonized component for an
extended corona.Comment: 19 pages, 13 figures; accepted for publication in MNRA
L'antitesi Diocleziano-martiri nel cristianesimo copto
A cura di Gherardo Gnoli e Giulia Sfameni Gasparro
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