Development of boron calibration via hybrid comparator method in prompt gamma activation analysis

The prompt gamma activation analysis (PGAA) facility at the Nuclear Engineering Teaching Laboratory at The University of Texas at Austin was utilized to quantify boron concentrations in boron carbide semiconductor films deposited on silicon substrates. Calibration was complicated by the unique and varying sample geometries analyzed. In addition, there was a dearth of solid materials available with quantified boron concentrations having comparable or readily modifiable dimensions to exploit for calibration purposes. Therefore, a novel hybrid comparator method was developed for the quantification of boron utilizing aluminum as an inexpensive and easily machinable reference material. Aluminum samples were manufactured with high tolerances to match the geometry of each sample of interest. Each boron carbide film sample and its congruent aluminum sample were measured in the PGAA system. The measured aluminum responses and relevant nuclear parameters were used to standardize the measurements. A boron standard was created using a procedure derived from a similar approach used by the National Institute of Standards and Technology. Quality control measurements using this standard show that the method provided accuracy to within 5% for boron quantification

Signal-Jamming in a Sequential Auction

In a recurring auction early bids may reveal bidders’ types, which in turn affects bidding in later auctions. Bidders take this into account and may bid in a way that conceals their private information until the last auction is played. The present paper analyzes the equilibrium of a sequence of ?rst-price auctions assuming bidders have stable private values. We show that signal-jamming occurs and explore the dynamics of equilibrium prices

Implantable Sensor System for Remote Detection of a Restenosis Condition

Part 7: Perceptional SystemsInternational audienceThe increase of life expectancy in the European Union, and the high risk of cardiovascular diseases associated with age, are some of the main factors to contribute to the rise of healthcare costs. An intelligent stent (e-stent), capable of obtaining and transmitting real-time measurements of physiological parameters for its clinical consultation, can be a useful tool for long-term monitoring, diagnostic, and early warning system for arterial blockage without patient hospitalization. In this paper, a behavioural model of capacitive Micro-Electro-Mechanical (MEMS) pressure sensor is proposed and simulated under several restenosis conditions. Special attention has been given to the need of an accurate fault model, obtained from realistic finite-element simulations,to ensure long-term reliability; particularly for those faults whose behavior cannot be easily described by an analytical model

Lack of Methyl-CpG Binding Protein 2 (MeCP2) Affects Cell Fate Refinement During Embryonic Cortical Development

During differentiation, neurons progressively restrict their fate repressing the expression of specific genes. Here we describe the involvement in such developmental steps of the methyl-CpG binding protein 2 (MeCP2), an epigenetic factor that participates to chromatin folding and transcriptional regulation. We previously reported that, due to transcriptional impairments, the maturation of Mecp2 null neurons is delayed. To evaluate whether this could stem from altered progenitors proliferation and differentiation, we investigated whether lack of Mecp2 affects these features both in vitro and in vivo. We show that in Mecp2 null embryonic cortexes the expression of genes defining the identity of proliferating neuroprogenitors is enriched and that their permanence in the G1 phase is prolonged. Moreover, the number of cells transitioning from a stage of maturation to a more mature one is increased in Mecp2 null embryonic cortices, in line with the central role of G1 for cell identity refinement. We thus suggest that, possibly due to the lack of proper transcriptional control normally exerted by Mecp2, fate refinement is impaired in developing null cells. We propose that the maturation delay affecting the developing Mecp2 null cortex originates, at least in part, from deranged mechanisms of cell fate refinement

Diamond deposition on modified silicon substrates: Making diamond atomic force microscopy tips for nanofriction experiments

Fine-crystalline diamond particles are grown on standard Si atomic force microscopy tips, using hot filament-assisted chemical vapor deposition. To optimize the conditions for diamond deposition, first a series of experiments is carried out using silicon substrates covered by point-topped pyramids as obtained by wet chemical etching. The apexes and the edges of the silicon pyramids provide favorable sites for diamond nucleation and growth. The investigation of the deposited polycrystallites is done by means of optical microscopy, scanning electron microscopy and micro-Raman spectroscopy. The resulting diamond-terminated tips are tested in ultra high vacuum using contact-mode atomic force microscope on a stepped surface of sapphire showing high stability, sharpness, and hardnes

A two-year participatory intervention project with owners to reduce lameness and limb abnormalities in working horses in Jaipur, India

Participatory methods are increasingly used in international human development, but scientific evaluation of their efficacy versus a control group is rare. Working horses support families in impoverished communities. Lameness and limb abnormalities are highly prevalent in these animals and a cause for welfare concern. We aimed to stimulate and evaluate improvements in lameness and limb abnormalities in horses whose owners took part in a 2-year participatory intervention project to reduce lameness (PI) versus a control group (C) in Jaipur, India.In total, 439 owners of 862 horses participated in the study. PI group owners from 21 communities were encouraged to meet regularly to discuss management and work practices influencing lameness and poor welfare and to track their own progress in improving these. Lameness examinations (41 parameters) were conducted at the start of the study (Baseline), and after 1 year and 2 years. Results were compared with control horses from a further 21 communities outside the intervention. Of the 149 horses assessed on all three occasions, PI horses showed significantly (P<0.05) greater improvement than C horses in 20 parameters, most notably overall lameness score, measures of sole pain and range of movement on limb flexion. Control horses showed slight but significantly greater improvements in four parameters, including frog quality in fore and hindlimbs.This participatory intervention succeeded in improving lameness and some limb abnormalities in working horses, by encouraging changes in management and work practices which were feasible within owners’ socioeconomic and environmental constraints. Demonstration of the potentially sustainable improvements achieved here should encourage further development of participatory intervention approaches to benefit humans and animals in other contexts

Second-price auctions with private entry costs

We study asymmetric second-price auctions under incomplete information. The bidders have potentially different, commonly-known, valuations for the object and private information about their entry costs. The seller, however, does not benefit from these entry costs. We calculate the equilibrium strategies of the bidders and analyze the optimal design for the seller in this environment

Risks of ozonated oil and ozonated water on human skin: A systematic review

Ozonated water and oil are emerging as potential dermatologic therapeutics, particularly for the treatment of various wounds. However, the safety of these liquids has not been extensively studied. The aim of this systematic review was to evaluate the risks of ozonated liquids to human skin tissue based on the available literature. We completed a structured search of five scientific databases and identified 378 articles for consideration. Based on pre-established inclusion/exclusion criteria, nine studies were included in this review. Two studies specifically evaluated the cytotoxicity of ozonated liquids on human cells, five studies evaluated ozonated liquids in randomised controlled trials(RCTs), one was a post-market surveillance study, and one was a cross over study in humans. None of the included studies found any significant human dermatologic risks associated with ozonated water or liquid. Because of the small sample size, however, additional short- and long-term RCTs specifically designed to evaluate the dermatological risks of ozonated liquids are recommended.This study was funded by an unrestricted grant from 3Oe Scientific, Inc., a technology company evaluating human applications for aqueous ozone

Improving polio vaccination during supplementary campaigns at areas of mass transit in India

<p>Abstract</p> <p>Background</p> <p>In India, children who are traveling during mass immunization campaigns for polio represent a substantial component of the total target population. These children are not easily accessible to health workers and may thus not receive vaccine. Vaccination activities at mass transit sites (such as major intersections, bus depots and train stations), can increase the proportion of children vaccinated but the effectiveness of these activities, and factors associated with their success, have not been rigorously evaluated.</p> <p>Methods</p> <p>We assessed data from polio vaccination activities in Jyotiba Phule Nagar district, Uttar Pradesh, India, conducted in June 2006. We used trends in the vaccination results from the June activities to plan the timing, locations, and human resource requirements for transit vaccination activities in two out of the seven blocks in the district for the July 2006 supplementary immunization activity (SIA). In July, similar data was collected and for the first time vaccination teams also recorded the proportion of children encountered each day who were vaccinated (a new monitoring system).</p> <p>Results</p> <p>In June, out of the 360,937 total children vaccinated, 34,643 (9.6%) received vaccinations at mass transit sites. In the July SIA, after implementation of a number of changes based on the June monitoring data, 36,475 children were vaccinated at transit sites (a 5.3% increase). Transit site vaccinations in July increased in the two intervention blocks from 18,194 to 21,588 (18.7%) and decreased from 16,449 to 14,887 (9.5%) in the five other blocks. The new monitoring system showed the proportion of unvaccinated children at street intersection transit sites in the July campaign decreased from 24% (1,784/7,405) at the start of the campaign to 3% (143/5,057) by the end of the SIA, consistent with findings from the more labor-intensive post-vaccination coverage surveys routinely performed by the program.</p> <p>Conclusions</p> <p>Analysis of vaccination data from transit sites can inform program management changes leading to improved outcomes in polio immunization campaigns. The number of vaccinated children encountered should be routinely recorded by transit teams and may provide a useful, inexpensive alternative mechanism to assess program coverage.</p