9,045 research outputs found
Understanding behaviour in problem structuring methods interventions with activity theory
This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.This article argues that OR interventions, particularly problem structuring methods (PSM), are complex events that cannot be understood by conventional methods alone. In this paper an alternative approach is introduced, where the units of analysis are the activity systems constituted by and constitutive of PSM interventions. The paper outlines the main theoretical and methodological concerns that need to be appreciated in studying PSM interventions. The paper then explores activity theory as an approach to study them. A case study describing the use of this approach is provided
Quantifying the value of problem structuring interventions?
We review the current work on measuring and evaluating PSM interventions and return to the paradox of trying to determine a specific monetary value. In an attempt to resolve the paradox, we have borrowed freely from economic theory and constructed a scenario where the question of value can be investigated through the effect that a problem structuring intervention will have on information asymmetry in contract formation. This suggests an avenue of research where the value of problem structuring interventions can be investigated empirically. We discuss the difficulties of research design to investigate this question but also the potential benefits.European Commissio
Construction of two whole genome radiation hybrid panels for dromedary (Camelus dromedarius): 5000RAD and 15000RAD
The availability of genomic resources including linkage information for camelids has been very limited. Here, we describe the construction of a set of two radiation hybrid (RH) panels (5000RAD and 15000RAD) for the dromedary (Camelus dromedarius) as a permanent genetic resource for camel genome researchers worldwide. For the 5000RAD panel, a total of 245 female camel-hamster radiation hybrid clones were collected, of which 186 were screened with 44 custom designed marker loci distributed throughout camel genome. The overall mean retention frequency (RF) of the final set of 93 hybrids was 47.7%. For the 15000RAD panel, 238 male dromedary-hamster radiation hybrid clones were collected, of which 93 were tested using 44 PCR markers. The final set of 90 clones had a mean RF of 39.9%. This 15000RAD panel is an important high-resolution complement to the main 5000RAD panel and an indispensable tool for resolving complex genomic regions. This valuable genetic resource of dromedary RH panels is expected to be instrumental for constructing a high resolution camel genome map. Construction of the set of RH panels is essential step toward chromosome level reference quality genome assembly that is critical for advancing camelid genomics and the development of custom genomic tools
Superfluid current disruption in a chain of weakly coupled Bose-Einstein Condensates
We report the experimental observation of the disruption of the superfluid
atomic current flowing through an array of weakly linked Bose-Einstein
condensates. The condensates are trapped in an optical lattice superimposed on
a harmonic magnetic potential. The dynamical response of the system to a change
of the magnetic potential minimum along the optical lattice axis goes from a
coherent oscillation (superfluid regime) to a localization of the condensates
in the harmonic trap ("classical" insulator regime). The localization occurs
when the initial displacement is larger than a critical value or, equivalently,
when the velocity of the wavepacket's center of mass is larger than a critical
velocity dependent on the tunnelling rate between adjacent sites.Comment: 8 pages, 4 figure
Spontaneous emission of atoms via collisions of Bose-Einstein condensates
The widely used Gross-Pitaevskii equation treats only coherent aspects of the
evolution of a Bose-Einstein condensate. However, inevitably some atoms scatter
out of the condensate. We have developed a method, based on the field theory
formulation, describing the dynamics of incoherent processes which are due to
elastic collisions. We can therefore treat processes of spontaneous emission of
atoms into the empty modes, as opposed to stimulated processes, which require
non-zero initial occupation.
In this article we study two counter-propagating plane waves of atoms,
calculating the full dynamics of mode occupation, as well as the statistics of
scattered atoms. The more realistic case of Gaussian wavepackets is also
analyzed.Comment: 5 pages, 2 figure
Annual Variation in Northern Bobwhite Survival and Raptor Migration
We estimated survival of radio-marked northern bobwhite (Colinus virginianus) on a managed prairie site in northeast Mississippi during 2 disparate winters (15 Sep-14 Apr 2000–2002). We retrospectively examined factors that may influence bobwhite survival. Pooled survival rates differed substantially between years (S 1⁄4 0.03 6 0.02 in 2000–2001 and S 1⁄4 0.36 6 0.16 in 2001–2002). Regional relative abundance of 3 species of raptors thought to be important predators of bobwhite was greater during 2000 compared to 2001 based on kriging of Christmas Bird Count (CBC) data. We demonstrate an approach for characterizing annual variation in spatial distribution of migratory raptors and suggest that annual variation in local winter predator context may be useful for explaining annual variation in winter survival of local bobwhite populations
The thermal QCD transition with two flavours of twisted mass fermions
We investigate the thermal QCD transition with two flavors of maximally
twisted mass fermions for a set of pion masses, 300 MeV \textless
\textless 500 MeV, and lattice spacings \textless 0.09 fm. We determine the
pseudo-critical temperatures and discuss their extrapolation to the chiral
limit using scaling forms for different universality classes, as well as the
scaling form for the magnetic equation of state. For all pion masses considered
we find resonable consistency with O(4) scaling plus leading corrections.
However, a true distinction between the O(4) scenario and a first order
scenario in the chiral limit requires lighter pions than are currently in use
in simulations of Wilson fermions.Comment: 11 pages, 11 figure
Multilingual assessment of early child development: Analyses from repeated observations of children in Kenya.
In many low- and middle-income countries, young children learn a mother tongue or indigenous language at home before entering the formal education system where they will need to understand and speak a countrys official language(s). Thus, assessments of children before school age, conducted in a nations official language, may not fully reflect a childs development, underscoring the importance of test translation and adaptation. To examine differences in vocabulary development by language of assessment, we adapted and validated instruments to measure developmental outcomes, including expressive and receptive vocabulary. We assessed 505 2-to-6-year-old children in rural communities in Western Kenya with comparable vocabulary tests in three languages: Luo (the local language or mother tongue), Swahili, and English (official languages) at two time points, 5-6 weeks apart, between September 2015 and October 2016. Younger children responded to the expressive vocabulary measure exclusively in Luo (44%-59% of 2-to-4-year-olds) much more frequently than did older children (20%-21% of 5-to-6-year-olds). Baseline receptive vocabulary scores in Luo (β = 0.26, SE = 0.05, p < 0.001) and Swahili (β = 0.10, SE = 0.05, p = 0.032) were strongly associated with receptive vocabulary in English at follow-up, even after controlling for English vocabulary at baseline. Parental Luo literacy at baseline (β = 0.11, SE = 0.05, p = 0.045) was associated with child English vocabulary at follow-up, while parental English literacy at baseline was not. Our findings suggest that multilingual testing is essential to understanding the developmental environment and cognitive growth of multilingual children
Understanding front-end project workshops with Social Practice Theory
This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.Stimulated by the growing interest in understanding the actuality of project managing and the need to better understand how front-end project workshops can be efficacious, we aim to turn workshops-as-practice into a meaningful object of inquiry. We operationalise Social Practice Theory by studying the intertwining of materials, skills and meaning in video-recorded micro-episodes in a front-end project workshop. Our findings illustrate how material elements provide sensitive assistance as professional skills are enacted in structuring the project-specific urban development challenge. Our theoretical, methodological and empirical approach makes the characteristic tension of practice between transformation and reproduction accessible for empirical inquiry and theorising from practice, thereby helping to develop project management knowledge that resonates with the experience of the project practitioner.This work was supported in part by the EU FP7-ENERGY- SMARTCITIES-2012 (314277) project STEEP (Systems Thinking for Comprehensive City Efficient Energy Planning) and the EPSRC funded Industrial Doctorate Centre in Systems (Grant EP/G037353/1)
Atomic Bose-Fermi mixtures in an optical lattice
A mixture of ultracold bosons and fermions placed in an optical lattice
constitutes a novel kind of quantum gas, and leads to phenomena, which so far
have been discussed neither in atomic physics, nor in condensed matter physics.
We discuss the phase diagram at low temperatures, and in the limit of strong
atom-atom interactions, and predict the existence of quantum phases that
involve pairing of fermions with one or more bosons, or, respectively, bosonic
holes. The resulting composite fermions may form, depending on the system
parameters, a normal Fermi liquid, a density wave, a superfluid liquid, or an
insulator with fermionic domains. We discuss the feasibility for observing such
phases in current experiments.Comment: 4 pages, 1 eps figure, misprints correcte
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