Multiuser detection with an unknown number of active users: receiver design

In multiuser detection, the set of users active at any time may be unknown to the receiver. In these conditions, optimum reception consists of detecting simultaneously the set of activeusers and their data, problem that can be solved exactly by applying random-set theory (RST) and Bayesian recursions (BR). However, implementation of optimum receivers may be limited by their complexity, which grows exponentially with the number of potential users. In this paper we examine three strategies leading to reduced-complexity receivers.In particular, we show how a simple approximation of BRs enables the use of Sphere Detection (SD) algorithm, whichexhibits satisfactory performance with limited complexity.

From a pattern-language to a pattern ontology approach for CSCL script design

Collaborative activities, in which students actively interact with each other, have proved to provide significant learning benefits. In Computer-Supported Collaborative Learning (CSCL), these collaborative activities are assisted by technologies. However, the use of computers does not guarantee collaboration, as free collaboration does not necessary lead to fruitful learning. Therefore, practitioners need to design CSCL scripts that structure the collaborative settings so that they promote learning. However, not all teachers have the technical and pedagogical background needed to design such scripts. With the aim of assisting teachers in designing effective CSCL scripts, we propose a model to support the selection of reusable good practices (formulated as patterns) so that they can be used as a starting point for their own designs. This model is based on a pattern ontology that computationally represents the knowledge captured on a pattern language for the design of CSCL scripts. A preliminary evaluation of the proposed approach is provided with two examples based on a set of meaningful interrelated patters computationally represented with the pattern ontology, and a paper prototyping experience carried out with two teaches. The results offer interesting insights towards the implementation of the pattern ontology in software tools.

Vaccination Strategies against Highly Pathogenic Arenaviruses: The Next Steps toward Clinical Trials.

Vaccination is one of the most valuable weapons against infectious diseases and has led to a significant reduction in mortality and morbidity. However, for most viral hemorrhagic fevers caused by arenaviruses, no prophylactic vaccine is available. This is particularly problematic as these diseases are notoriously difficult to diagnose and treat. Lassa fever is globally the most important of the fevers caused by arenaviruses, potentially affecting millions of people living in endemic areas, particularly in Nigeria. Annually, an estimated 300,000 humans are infected and several thousands succumb to the disease. The successful development of the vaccine "Candid#1" against Junin virus, the causative agent of Argentine hemorrhagic fever, proved that an effective arenavirus vaccine can be developed. Although several promising studies toward the development of a Lassa fever vaccine have been published, no vaccine candidate has been tested in human volunteers or patients. This review summarizes the immunology and other aspects of existing experimental arenavirus vaccine studies, discusses the reasons for the lack of a vaccine, and proposes a plan for overcoming the final hurdles toward clinical trials.

Design and Construction Procedures for Concrete Overlay and Widening of Existing Pavements, September 2005

State Highway Departments and local street and road agencies are currently faced with aging highway systems and a need to extend the life of some of the pavements. The agency engineer should have the opportunity to explore the use of multiple surface types in the selection of a preferred rehabilitation strategy. This study was designed to look at the portland cement concrete overlay alternative and especially the design of overlays for existing composite (portland cement and asphaltic cement concrete) pavements. Existing design procedures for portland cement concrete overlays deal primarily with an existing asphaltic concrete pavement with an underlying granular base or stabilized base. This study reviewed those design methods and moved to the development of a design for overlays of composite pavements. It deals directly with existing portland cement concrete pavements that have been overlaid with successive asphaltic concrete overlays and are in need of another overlay due to poor performance of the existing surface. The results of this study provide the engineer with a way to use existing deflection technology coupled with materials testing and a combination of existing overlay design methods to determine the design thickness of the portland cement concrete overlay. The design methodology provides guidance for the engineer, from the evaluation of the existing pavement condition through the construction of the overlay. It also provides a structural analysis of various joint and widening patterns on the performance of such designs. This work provides the engineer with a portland cement concrete overlay solution to composite pavements or conventional asphaltic concrete pavements that are in need of surface rehabilitation.

Phenotypes influencing low physical activity in maintenance dialysis.

OBJECTIVE: The "Pas à Pas" initiative aimed at evaluating the weekly physical activity (PA) and its determinants in a large cohort of dialysis patients. SETTING: Physical inactivity is a risk factor for mortality in maintenance dialysis patients and is still poorly documented in this population. DESIGN: A prospective national epidemiological study was performed. SUBJECTS: A total of 1,163 patients on maintenance dialysis (hemodialysis and peritoneal dialysis) were included. INTERVENTION AND MAIN OUTCOME MEASURE: PA was recorded during seven consecutive days using a pedometer to measure daily step numbers. RESULTS: Median age was 63 years (Q1 51-Q3 75). Sixty-three percent were sedentary (<5000 steps/day) with a median of 3,688 steps/day (1,866-6,271)]. PA level was similar between hemodialysis patients and those on peritoneal dialysis (3,693 steps [1,896-6,307] vs. 3,320 [1,478-5,926], P = .33). In hemodialysis patients, PA was lower on dialysis days compared with nondialysis days (2,912 [1,439-5,232] vs. 4,054 [2,136-7,108], respectively, P < .01). PA gradually decreased with age, 57% being sedentary between 50 and 65 years and 83% of patients after 80 years. Beyond this age effect, we identified, for the first time, specific phenotypes of patients with lower PA, such as inflammation, cardiovascular disease, protein energy wasting, obesity, and diabetes. By contrast, previous kidney transplantation and a higher muscle mass were associated with higher PA. CONCLUSIONS: Dialysis patients present a very low level of PA with high sedentary. Acting on patient's modifiable phenotypes may help to increase PA to improve morbidity, mortality, and quality of life.

Universal Design for Better Living The Essential Bathroom, May 2004

An easy-living home requires a full-sized bathroom on the main level. Family members will appreciate the extra space and guests of all ages and abilities will feel more welcome. At a minimum, you’ll need a five foot circle of open floor space for maneuvering a wheelchair between bathroom fixtures. A small powder room won’t work for guests who use walkers or wheelchairs. A shower stall—with no curb to step over—is more convenient than a tub for most guests. Make sure the doorway opening for the bathroom is at least 32 inches wide (preferably 36 inches). Universal design features, such as these, make homes better for everyone.

Universal Design for Better Living: “Where to Get Gadgets and Gizmos”, May 2004

If they don’t carry the item, ask them to order it for you. Look at discount stores, such as Target, Wal-Mart, K-Mart, or Menard’s (they are more likely to carry items with universal design features). Look at the “Gadgets and Gizmos” section of the Iowa State University Extension Web site on “Universal Design & Home Accessibility.”

Influence of a lifestyle intervention in preschool children on physiological and psychological parameters (Ballabeina): study design of a cluster randomized controlled trial.

Childhood obesity and physical inactivity are increasing dramatically worldwide. Children of low socioeconomic status and/or children of migrant background are especially at risk. In general, the overall effectiveness of school-based programs on health-related outcomes has been disappointing. A special gap exists for younger children and in high risk groups. This paper describes the rationale, design, curriculum, and evaluation of a multicenter preschool randomized intervention study conducted in areas with a high migrant population in two out of 26 Swiss cantons. Twenty preschool classes in the German (canton St. Gallen) and another 20 in the French (canton Vaud) part of Switzerland were separately selected and randomized to an intervention and a control arm by the use of opaque envelopes. The multidisciplinary lifestyle intervention aimed to increase physical activity and sleep duration, to reinforce healthy nutrition and eating behaviour, and to reduce media use. According to the ecological model, it included children, their parents and the teachers. The regular teachers performed the majority of the intervention and were supported by a local health promoter. The intervention included physical activity lessons, adaptation of the built infrastructure; promotion of regional extracurricular physical activity; playful lessons about nutrition, media use and sleep, funny homework cards and information materials for teachers and parents. It lasted one school year. Baseline and post-intervention evaluations were performed in both arms. Primary outcome measures included BMI and aerobic fitness (20 m shuttle run test). Secondary outcomes included total (skinfolds, bioelectrical impedance) and central (waist circumference) body fat, motor abilities (obstacle course, static and dynamic balance), physical activity and sleep duration (accelerometry and questionnaires), nutritional behaviour and food intake, media use, quality of life and signs of hyperactivity (questionnaires), attention and spatial working memory ability (two validated tests). Researchers were blinded to group allocation. The purpose of this paper is to outline the design of a school-based multicenter cluster randomized, controlled trial aiming to reduce body mass index and to increase aerobic fitness in preschool children in culturally different parts of Switzerland with a high migrant population. Trial Registration: (clinicaltrials.gov) NCT00674544.

Design Guide and Construction Specifications for National Pollutant Discharge Elimination System (NPDES) Site Runoff Control, 2006

According to the 1972 Clean Water Act, the Environmental Protection Agency (EPA) established a set of regulations for the National Pollutant Discharge Elimination System (NPDES). The purpose of these regulations is to reduce pollution of the nation’s waterways. In addition to other pollutants, the NPDES regulates stormwater discharges associated with industrial activities, municipal storm sewer systems, and construction sites. Phase II of the NPDES stormwater regulations, which went into effect in Iowa in 2003, applies to construction activities that disturb more than one acre of ground. The regulations also require certain communities with Municipal Separate Storm Sewer Systems (MS4) to perform education, inspection, and regulation activities to reduce stormwater pollution within their communities. Iowa does not currently have a resource to provide guidance on the stormwater regulations to contractors, designers, engineers, and municipal staff. The Statewide Urban Design and Specifications (SUDAS) manuals are widely accepted as the statewide standard for public improvements. The SUDAS Design manual currently contains a brief chapter (Chapter 7) on erosion and sediment control; however, it is outdated, and Phase II of the NPDES stormwater regulations is not discussed. In response to the need for guidance, this chapter was completely rewritten. It now escribes the need for erosion and sediment control and explains the NPDES stormwater regulations. It provides information for the development and completion of Stormwater Pollution Prevention Plans (SWPPPs) that comply with the stormwater regulations, as well as the proper design and implementation of 28 different erosion and sediment control practices. In addition to the design chapter, this project also updated a section in the SUDAS Specifications manual (Section 9040), which describes the proper materials and methods of construction for the erosion and sediment control practices.

Optimal Design of Permit Markets with an Ex Ante Pollution Target, August 2006

In this paper, we examine the design of permit trading programs when the objective is to minimize the cost of achieving an ex ante pollution target, that is, one that is defined in expectation rather than an ex post deterministic value. We consider two potential sources of uncertainty, the presence of either of which can make our model appropriate: incomplete information on abatement costs and uncertain delivery coefficients. In such a setting, we find three distinct features that depart from the well-established results on permit trading: (1) the regulator’s information on firms’ abatement costs can matter; (2) the optimal permit cap is not necessarily equal to the ex ante pollution target; and (3) the optimal trading ratio is not necessarily equal to the delivery coefficient even when it is known with certainty. Intuitively, since the regulator is only required to meet a pollution target on average, she can set the trading ratio and total permit cap such that there will be more pollution when abatement costs are high and less pollution when abatement costs are low. Information on firms’ abatement costs is important in order for the regulator to induce the optimal alignment between pollution level and abatement costs.

The GTPase RalA regulates different steps of the secretory process in pancreatic beta-cells.

BACKGROUND: RalA and RalB are multifuntional GTPases involved in a variety of cellular processes including proliferation, oncogenic transformation and membrane trafficking. Here we investigated the mechanisms leading to activation of Ral proteins in pancreatic beta-cells and analyzed the impact on different steps of the insulin-secretory process. METHODOLOGY/PRINCIPAL FINDINGS: We found that RalA is the predominant isoform expressed in pancreatic islets and insulin-secreting cell lines. Silencing of this GTPase in INS-1E cells by RNA interference led to a decrease in secretagogue-induced insulin release. Real-time measurements by fluorescence resonance energy transfer revealed that RalA activation in response to secretagogues occurs within 3-5 min and reaches a plateau after 10-15 min. The activation of the GTPase is triggered by increases in intracellular Ca2+ and cAMP and is prevented by the L-type voltage-gated Ca2+ channel blocker Nifedipine and by the protein kinase A inhibitor H89. Defective insulin release in cells lacking RalA is associated with a decrease in the secretory granules docked at the plasma membrane detected by Total Internal Reflection Fluorescence microscopy and with a strong impairment in Phospholipase D1 activation in response to secretagogues. RalA was found to be activated by RalGDS and to be severely hampered upon silencing of this GDP/GTP exchange factor. Accordingly, INS-1E cells lacking RalGDS displayed a reduction in hormone secretion induced by secretagogues and in the number of insulin-containing granules docked at the plasma membrane. CONCLUSIONS/SIGNIFICANCE: Taken together, our data indicate that RalA activation elicited by the exchange factor RalGDS in response to a rise in intracellular Ca2+ and cAMP controls hormone release from pancreatic beta-cell by coordinating the execution of different events in the secretory pathway.

Problematizing the multidisciplinary residency in oncology: a practical teaching protocol from the perspective of nurse residents

Objective: To investigate practical teaching of nurse residents in a multidisciplinary residency in oncology. Method: A qualitative descriptive study grounded in the problematization methodology and its steps, represented by the Maguerez Arch. Data were analyzed using content analysis. Results: Potentiating and limiting elements of the residency guided the design of a practical teaching protocol from the perspective of residents, structured in three stages: Welcoming and ambience; Nursing care for problem situations; and, Evaluation process. Conclusion: Systematization of practical teaching promoted the autonomy of individuals and the approximation of teaching to reality, making residency less strenuous, stressful and distressing.



Development and validating an educational booklet for childbirth companions

Objective The article describes the steps in producing and validating an educational booklet for childbirth companions. Method Methodological study conducted in 2011 consisting of the following steps: situational assessment; establishing brochure content; content selection and referencing; drafting the text; design of illustrations; layout; consultation of specialists; consultation of target audience; amendments; proofreading; evaluation using the Flesch Reading Ease Formula. The topics portrayed the sequence of events involving support from gestation to the postpartum period. Results The concordance rate among companions was greater than or equal to 81.8% for the topics organisation, writing style, presentation and motives. The overall Content Validity Index of the booklet was 0.94. The booklet was classified as easy reading or very easy reading according to the results of the Flesch Reading Ease Formula. Conclusion The presentation and content of the manual were validated for use with the target audience by the specialists and representatives of the target audience.

Experimental design on the simplex

Optimum experimental designs depend on the design criterion, the model andthe design region. The talk will consider the design of experiments for regressionmodels in which there is a single response with the explanatory variables lying ina simplex. One example is experiments on various compositions of glass such asthose considered by Martin, Bursnall, and Stillman (2001).Because of the highly symmetric nature of the simplex, the class of models thatare of interest, typically Scheff´e polynomials (Scheff´e 1958) are rather differentfrom those of standard regression analysis. The optimum designs are also ratherdifferent, inheriting a high degree of symmetry from the models.In the talk I will hope to discuss a variety of modes for such experiments. ThenI will discuss constrained mixture experiments, when not all the simplex is availablefor experimentation. Other important aspects include mixture experimentswith extra non-mixture factors and the blocking of mixture experiments.Much of the material is in Chapter 16 of Atkinson, Donev, and Tobias (2007).If time and my research allows, I would hope to finish with a few comments ondesign when the responses, rather than the explanatory variables, lie in a simplex.ReferencesAtkinson, A. C., A. N. Donev, and R. D. Tobias (2007). Optimum ExperimentalDesigns, with SAS. Oxford: Oxford University Press.Martin, R. J., M. C. Bursnall, and E. C. Stillman (2001). Further results onoptimal and efficient designs for constrained mixture experiments. In A. C.Atkinson, B. Bogacka, and A. Zhigljavsky (Eds.), Optimal Design 2000,pp. 225–239. Dordrecht: Kluwer.Scheff´e, H. (1958). Experiments with mixtures. Journal of the Royal StatisticalSociety, Ser. B 20, 344–360.1