1,208 research outputs found
Authentic tasks online: Two experiences
This chapter presents an exploration of the design and methods of two instantiations of authentic learning tasks in online learning environments. The first case employs a service learning orientation involving a distance learning project taught to students in four sites in two countries, while the second case is of a multimedia-based learning environment employing a scenario to engage students in realistic, simulated learning activities. The two approaches are examined through reference to characteristics of authentic tasks. The chapter demonstrates a range of possibilities for the instructor interested in more informed design of technology-based learning environments in higher education, and in particular, the design and creation of authentic learning tasks
Self-Focusing Dynamics of Coupled Optical Beams
We theoretically and experimentally investigate the mutual collapse dynamics
of two spatially separated optical beams in a Kerr medium. Depending on the
initial power, beam separation, and the relative phase, we observe repulsion or
attraction, which in the latter case reveals a sharp transition to a single
collapsing beam. This transition to fusion of the beams is accompanied by an
increase in the collapse distance, indicating the effect of the nonlinear
coupling on the individual collapse dynamics. Our results shed light on the
basic nonlinear interaction between self-focused beams and provide a mechanism
to control the collapse dynamics of such beams.Comment: 5 pages, 4 figure
Implementation and Evaluation of Power Consumption of an Iris Pre-processing Algorithm on Modern FPGA
In this article, the efficiency and applicability of several power reduction techniques applied on a modern 65nm FPGA is described. For image erosion and dilation algorithms, two major solutions were tested and compared with respect to power and energy consumption. Firstly the algorithm was run on a general purpose processor (gpp) NIOS and then hardware architecture of an Intellectual Property (IP) was designed. Furthermore IPs design was improved by applying a number of power optimization techniques. They involved RTL level clock gating, power driven synthesis with fitting and appropriate coding style. Results show that hardware implementation is much more energy efficient than a general purpose processor and power optimization schemes can reduce the overall power consumption on an FPGA
Enhancement of Optical Coherence Tomography Images of the Retina by Normalization and Fusion
This paper describes an image processing method applied to Optical Coherence Tomography (OCT) images of the retina. The aim is to achieve improved OCT images from the fusion of sequential OCT scans obtained at identical retinal locations. The method is based on the normalization of the acquired images and their fusion. As a result, a noise reduction and an image enhancement are reached. Thanks to the resulting improvement in retinal imaging, clinical specialists are able to evaluate more efficiently eyes pathologies and anomalies. This paper presents the proposed method and gives some evaluation results
Effect of pancreatic and/or renal transplantation on diabetic autonomic neuropathy
Thirty-nine Type 1 (insulin-dependent) diabetic patients were studied prospectively after simultaneous pancreas and kidney (n=26) and kidney grafting alone (n=13) by measuring heart rate variation during various manoeuvers and answering a standardized questionnaire every 6 to 12 months post-transplant. While age, duration of diabetes, and serum creatinine (168.1±35.4 vs 132.7±17.7 mgrmol/l) were comparable, haemoglobin A1 levels were significantly lower (6.6±0.2 vs 8.5±0.3%; p<0.01) and the mean observation time longer (35±2 vs 25±3 months; p<0.05) in the pancreas recipients when compared with kidney transplanted patients. Heart rate variation during deep breathing, lying/standing and Valsalva manoeuver were very similar in both groups initially and did not improve during follow-up. However, there was a significant reduction in heart rate in the pancreas recipient group. Autonomic symptoms of the gastrointestinal and thermoregulatory system improved more in the pancreas grafted subjects, while hypoglycaemia unawareness deteriorated in the kidney recipients. This study suggests that long-term normoglycaemia by successful pancreatic grafting is able to halt the progression of autonomic dysfunction
Perinatal mental health service provision in Switzerland and the UK
Questions under study: The epidemiology of maternal perinatal-psychiatric disorders as well as their effect on the baby is well recognised. Increasingly well researched specialised treatment methods can reduce maternal morbidity, positively affect mother-baby bonding and empower women’s confidence as a mother.
Here, we aimed to compare guidelines and the structure of perinatal-psychiatric service delivery in the United Kingdom and in Switzerland from the government’s perspective.
Methods: Swiss cantons provided information regarding guidelines and structure of service delivery in 2000. A subsequent survey using the same questionnaire was carried out in 2007. In the UK, similar information was accessed through published reports from 2000-2012.
Results: Guidelines for perinatal psychiatry exist in the UK, whereas in Switzerland in 2000 none of the 26 cantons had guidelines, and in 2007 only one canton did. Joint mother-baby admissions on general psychiatric wards were offered by 92% of the Swiss cantons. In the UK, pregnant women and joint mother-baby admissions are only advised onto specialised perinatal-psychiatric units. In Switzerland, in 2007, three specialised units (max. 24 beds) were in place corresponding to 1 unit per 2.5 million people, while in the UK there were 22 mother-baby units (168 beds) in 2012 (1 unit per 2.8 million). In the UK, less than 50% of trusts provided specialised perinatal-psychiatric health care.
Conclusions: The main difference between the UK and Switzerland was the absence of guidelines, regular assessment and plans for future development of perinatal psychiatry in Switzerland. There are still geographical differences in the provision of perinatal-psychiatric services in the UK
Mitochondrial respiratory capacity is a critical regulator of CD8<sup>+</sup> T cell memory development
CD8+ T cells undergo major metabolic changes upon activation, but how metabolism influences the establishment of long-lived memory T cells after infection remains a key question. We have shown here that CD8+ memory T cells, but not CD8+ T effector (Teff) cells, possessed substantial mitochondrial spare respiratory capacity (SRC). SRC is the extra capacity available in cells to produce energy in response to increased stress or work and as such is associated with cellular survival. We found that interleukin-15 (IL-15), a cytokine critical for CD8+ memory T cells, regulated SRC and oxidative metabolism by promoting mitochondrial biogenesis and expression of carnitine palmitoyl transferase (CPT1a), a metabolic enzyme that controls the rate-limiting step to mitochondrial fatty acid oxidation (FAO). These results show how cytokines control the bioenergetic stability of memory T cells after infection by regulating mitochondrial metabolism
Psychosocial aspects of closed- and open-loop insulin delivery: closing the loop in adults with Type 1 diabetes in the home setting.
AIMS: To explore the psychosocial experiences of closed-loop technology and to compare ratings of closed- and open-loop technology for adults with Type 1 diabetes taking part in a randomized crossover study. METHODS: Adults (aged > 18 years) on insulin pump therapy were recruited to receive a first phase of either real-time continuous glucose monitoring with overnight closed-loop or real-time continuous glucose monitoring alone (open-loop) followed by a second phase of the alternative treatment in random order, at home for 4 weeks, unsupervised. Participants were invited to share their views in semi-structured interviews. The impact of the closed-loop technology, positive and negative aspects of living with the device overnight, along with the hopes and anxieties of the participants, were explored. RESULTS: The participants in the trial were 24 adults with a mean (sd) age of 43 (12) years, of whom 54% were men. The mean (range) interview duration was 26 (12-46) min. Content and thematic analysis showed the following key positive themes: improved blood glucose control (n = 16); reassurance/reduced worry (n = 16); improved overnight control leading to improved daily functioning and diabetes control (n = 16); and improved sleep (n = 8). The key negative themes were: technical difficulties (n = 24); intrusiveness of alarms (n = 13); and size of equipment (n = 7). Of the 24 participant, 20 would recommend the closed-loop technology. CONCLUSIONS: Closed-loop therapy has positive effects when it works in freeing participants from the demands of self-management. The downside was technical difficulties, particularly concerning the pump and 'connectivity', which it is hoped will improve. Future research should continue to explore the acceptability of the closed-loop system as a realistic therapy option, taking account of user concerns as new systems are designed. Failure to do this may reduce the eventual utility of new systems.Diabetes UKThis is the accepted manuscript. The final version is available at http://dx.doi.org/10.1111/dme.12706
Ionizing Photon Emission Rates from O- and Early B-type Stars and Clusters
We present new computations of the ionizing spectral energy distributions
(SEDs) and Lyman continuum (Lyc) and HeI continuum photon emission rates, for
hot O-type and early B-type stars. We consider solar metallicity stars, with
effective temperatures ranging from 25,000 to 55,000 K and surface gravities
(cm s^-2) logg ranging from 3 to 4, covering the full range of spectral types
and luminosity classes for hot stars. We use our updated (WM-basic) code to
construct radiation-driven wind atmosphere models for hot stars. Our models
include the coupled effects of hydrodynamics and non-LTE radiative transfer in
spherically outflowing winds, including the detailed effects of metal line
blocking and line blanketing on the radiative transfer and energy balance. We
incorporate our hot-star models into our population synthesis code (STARS), and
we compute the time-dependent SEDs and resulting Lyc and HeI emission rates for
evolving star clusters. We present results for continuous and impulsive star
formation for a range of assumed stellar initial mass functions.Comment: 23 pages, 7 figures. To appear in the Astrophysical Journal. For grid
of star models see ftp://wise3.tau.ac.il/pub/star
Commitment to glycolysis sustains survival of NO-producing inflammatory dendritic cells
TLR agonists initiate a rapid activation program in dendritic cells (DCs) that requires support from metabolic and bioenergetic resources. We found previously that TLR signaling promotes aerobic glycolysis and a decline in oxidative phosphorylation (OXHPOS) and that glucose restriction prevents activation and leads to premature cell death. However, it remained unclear why the decrease in OXPHOS occurs under these circumstances. Using real-time metabolic flux analysis, in the present study, we show that mitochondrial activity is lost progressively after activation by TLR agonists in inflammatory blood monocyte–derived DCs that express inducible NO synthase. We found that this is because of inhibition of OXPHOS by NO and that the switch to glycolysis is a survival response that serves to maintain ATP levels when OXPHOS is inhibited. Our data identify NO as a profound metabolic regulator in inflammatory monocyte–derived DCs
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