Versatile Cold Atom Source for Multi-Species Experiments

We present a dual-species oven and Zeeman slower setup capable of producing slow, high-flux atomic beams for loading magneto-optical traps. Our compact and versatile system is based on electronic switching between different magnetic field profiles and is applicable to a wide range of multi-species experiments. We give details of the vacuum setup, coils and simple electronic circuitry. In addition, we demonstrate the performance of our system by optimized, sequential loading of magneto-optical traps of lithium-6 and cesium-133.Comment: 7 pages, 10 figure

The effects of a mid-morning bout of exercise on adolescents' cognitive function

The aim of the present study was to examine the effects of a mid-morning bout of exercise on adolescents’ cognitive function in a randomised crossover design where each participant completed two experimental trials. Forty-five adolescents (13.3±0.3 years old), undertook a bout of exercise (ten repeats of level one of the multi-stage fitness test, 30s rest between repeats; exercise trial) or continued to rest (resting trial). A battery of cognitive function tests assessing visuo-motor speed, executive function and working memory (visual search test, Stroop test and Sternberg paradigm, respectively) was completed 30 min before and 45 min following the exercise. Average heart rate during exercise was 172±17 beats/min. On the visual search test, there was a greater improvement in response times across the morning on the exercise trial (t=2.6, p=0.009). However, this improvement in response times was combined with a greater decrease in accuracy on the exercise trial (z=2.0, p=0.044). On the Sternberg paradigm there was a greater improvement in response times across the morning following exercise when compared to resting (t=2.6, p=0.010). The mid-morning bout of exercise did not affect Stroop test performance. These improvements in response times are most likely the result of a general speeding up of responses across several cognitive domains, because response times were improved similarly across two different domains and across all test complexity levels, rather than being restricted to the specific high cognitive load levels. Accordingly, exercise in school settings may help to improve cognitive function in adolescents during the school morning

Breakfast glycaemic index and cognitive function in adolescent school children

It has been suggested that a low-glycaemic index (GI) breakfast may be beneficial for some elements of cognitive function (e.g. memory and attention), but the effects are not clear, especially in adolescents. Thus, the aim of the present study was to examine the effects of a low-GI breakfast, a high-GI breakfast and breakfast omission on cognitive function in adolescents. A total of fifty-two adolescents aged 12–14 years were recruited to participate in the study. Participants consumed a low-GI breakfast, a high-GI breakfast or omitted breakfast. A battery of cognitive function tests was completed 30 and 120 min following breakfast consumption and capillary blood samples were taken during the 120 min postprandial period. The findings show that there was a greater improvement in response times following a low-GI breakfast, compared with breakfast omission on the Stroop (P=0·009) and Flanker (P=0·041) tasks, and compared with a high-GI breakfast on the Sternberg paradigm (P=0·013). Furthermore, accuracy on all three tests was better maintained on the low-GI trial compared with the high-GI (Stroop: P=0·039; Sternberg: P=0·018; Flanker: P=0·014) and breakfast omission (Stroop: P<0·001; Sternberg: P=0·050; Flanker: P=0·014) trials. Following the low-GI breakfast, participants displayed a lower glycaemic response (P<0·001) than following the high-GI breakfast, but there was no difference in the insulinaemic response (P=0·063) between the high- and low-GI breakfasts. Therefore, we conclude that a low-GI breakfast is most beneficial for adolescents' cognitive function, compared with a high-GI breakfast or breakfast omission

Enhanced Raman sideband cooling of caesium atoms in a vapour-loaded magneto-optical trap

We report enhanced three-dimensional degenerated Raman sideband cooling (3D DRSC) of caesium (Cs) atoms in a standard single-cell vapour-loaded magneto-optical trap. Our improved scheme involves using a separate repumping laser and optimized lattice detuning. We load 1.5 × 107 atoms into the Raman lattice with a detuning of −15.5 GHz (to the ground F = 3 state). Enhanced 3D DRSC is used to cool them from 60 µK to 1.7 µK within 12 ms and the number of obtained atoms is about 1.2 × 107. A theoretical model is proposed to simulate the measured number of trapped atoms. The result shows good agreement with the experimental data. The technique paves the way for loading a large number of ultracold Cs atoms into a crossed dipole trap and efficient evaporative cooling in a single-cell system

Collimated dual species oven source and its characterisation via spatially resolved fluorescence spectroscopy

We describe the design, construction and characterisation of a collimated, dual-species oven source for generating intense beams of lithium and caesium in UHV environments. Our design produces full beam overlap for the two species. Using an aligned microtube array the FWHM of the output beam is restricted to ~ 75 milliradians, with an estimated axial brightness of 3.6x10[superscript]14 atoms s[superscript]-1 sr[superscript]-1 for Li and 7.4x10[superscript]15 atoms s[superscript]-1 sr[superscript]-1 for Cs. We measure the properties of the output beam using a spatially-resolved fluorescence technique, which allows for the extraction of additional information not accessible without spatial resolution

BIO Logical Agents: Norms, Beliefs, Intentions in Defeasible Logic

In this paper we follow the BOID (Belief, Obligation, Intention, Desire) architecture to describe agents and agent types in Defeasible Logic. We argue, in particular, that the introduction of obligations can provide a new reading of the concepts of intention and intentionality. Then we examine the notion of social agent (i.e., an agent where obligations prevail over intentions) and discuss some computational and philosophical issues related to it. We show that the notion of social agent either requires more complex computations or has some philosophical drawbacks

Evaluation of three commercial metal artifact reduction methods for CT simulations in radiation therapy

Purpose: To evaluate the success of three commercial metal artifact reduction methods (MAR) in the context of radiation therapy treatment planning.Methods: Three MAR strategies were evaluated: Philips O-MAR, monochromatic imaging using Gemstone Spectral Imaging (GSI) dual energy CT, and monochromatic imaging with metal artifact reduction software (GSI-MARs). The Gammex RMI 467 tissue characterization phantom with several metal rods and two anthropomorphic phantoms (pelvic phantom with hip prosthesis and head phantom with dental fillings), were scanned with and without metals (baseline). Each MAR method was evaluated based on CT number accuracy, metal size accuracy, and reduction in the severity of streak artifacts. CT number difference maps between the baseline and metal scan images were calculated, and the severity of streak artifacts was quantified using the percentage of pixels with &gt; 40 HU error (“bad pixels”).Results: Philips O-MAR generally reduced HU errors in the RMI phantom. However, increased errors and induced artifacts were observed for lung materials. GSI monochromatic 70keV images generally showed similar HU errors as conventional 120kVp imaging, while 140keV images reduced HU errors. All the imaging techniques represented the diameter of a stainless steel rod to within ±1.6mm (2 pixels). For the hip prosthesis, O-MAR reduced the average % bad pixels from 47% to 32%. For GSI 140keV imaging, the % bad pixels was reduced from 37% to 29% compared to 120kVp imaging, and GSI-MARs further reduced it to 12%. For the head phantom, none of the MAR methods was particularly successful.Conclusion: O-MAR resulted in consistent artifact reduction but exhibited induced artifacts for metals located near lung tissue. GSI imaging at 140keV gave consistent reduction in HU errors and severity of artifacts. GSI-MARs at 140keV was the most successful MAR method for the hip prosthesis but exhibited induced artifacts at the edges of metals in some cases.---------------------------------Cite this article as: Huang JY, Kerns JR, Nute JL, Liu X, Stingo FC, Followill DS, Mirkovic D, Howell RM, Kry SF. Evaluation of three commercial metal artifact reduction methods for CT simulations in radiation therapy. Int J Cancer Ther Oncol 2014; 2(2):020224. DOI: 10.14319/ijcto.0202.2

Normative Autonomy and Normative Co-ordination: Declarative Power, Representation, and Mandate

In this paper we provide a formal analysis of the idea of normative co-ordination. We argue that this idea is based on the assumption that agents can achieve flexible co-ordination by conferring normative positions to other agents. These positions include duties, permissions, and powers. In particular, we explain the idea of declarative power, which consists in the capacity of the power-holder of creating normative positions, involving other agents, simply by "proclaiming" such positions. In addition, we account also for the concepts of representation, namely the representative's capacity of acting in the name of his principal, and of mandate, which is the mandatee's duty to act as the mandator has requested. Finally, we show how the framework can be applied to represent the contract-net protocol. Some brief remarks on future research and applications conclude this contribution