Knowledge Of Limits Research Articles

Interdisciplinary perspectives on dose limits in radioactive waste management. A research paper developed within the ENTRIA project

Within the ENTRIA project, an interdisciplinary group of scientists developed a research paper aiming at a synthesis of the technical, sociology of knowledge, legal, societal, and political aspects of dose limits within the field of radioactive waste management. In this paper, the ENTRIA project is briefly introduced and the work on dose limits is put into the perspective of this much larger project. Selected aspects of the ENTRIA work on dose limits related to the different roles such limits play for different actors as well as to the specific case of nuclear waste disposal are presented. The work recognizes that such limits are indispensable for technological developments and legal security but, at the same time, depend on country and project specific circumstances. This may result in serious conflicts and concerns in public debates as well as in the political realm. In order to better understand the interaction and interdependencies of these various contexts in which debates about dose limits play out, future interdisciplinary research is needed. This research should contribute to an open discourse on dose limits which reflects underlying values, objectives, actors and procedures that have defined present dose limit regimes. Additionally, this research should indicate paths for potential alternatives and complements to these established regimes.

Differences between Groups of Family Physicians with Different Attitudes towards At-Risk Drinkers: A Post Hoc Study of the ODHIN Survey in Portugal.

Introduction. We have recently shown that family physicians can be classified into two groups based on their attitudes towards at-risk drinkers: one with better and the other with worse attitudes. Objective. To compare the two groups regarding demographics, alcohol-related clinical practice, knowledge of sensible drinking limits, and barriers and facilitators to working with at-risk drinkers. Methods. A random sample of 234 Portuguese family physicians who answered the Optimizing Delivery of Health Care Interventions survey was included. The questionnaire asked questions on demographics, alcohol-related clinical practice, knowledge of sensible drinking limits, and barriers and facilitators to working with at-risk drinkers. Results. Family physicians with better attitudes were younger (p = 0.005) and less experienced (p = 0.04) and with higher male proportion (p = 0.01). This group had more hours of postgraduate training (p < 0.001), felt more prepared to counsel risky drinkers (p < 0.001), and considered themselves to have better counselling efficacy (p < 0.001). More family physicians in the group with worse attitudes considered that doctors cannot identify risky drinkers without symptoms (p = 0.01) and believed counselling is difficult (p = 0.005). Conclusions. Family physicians with better attitudes had more education on alcohol and fewer barriers to work with at-risk drinkers. These differences should be taken into account when designing implementation programs seeking to increase alcohol screening and brief advice.

Site Suitability Analysis for Cork Oak Regeneration Using GIS Based Multicriteria Evaluation Techniques in Maamora Forest-Morocco

Following the assumption that some soils are less suitable for the development of cork oak, a substitution of cork oak by exotic species has been carried out on a large part of Maamora forest. However, soil is not the only factor to consider in assessing the suitability. Therefore, some areas might just suit to cork oak but to what extent? To answer this question, major factors known to influence the regeneration of cork oak have been identified and mapped using multicriteria evaluation. Therefore, factors were incorporated by weighted linear combination to determine suitability indices for the regeneration of cork oak. The weight of each factor was estimated by expert judgment using the AHP (Analytic Hierarchy Process) approach. The main factors influencing the cork oak regeneration suitability in Maamora forest are climate expressed by “continentality”, terrainslope, thickness of the sand, slope of the clay floor layer, and plant communities and soil types. These factors were mapped by incorporating fuzzy logic in order to avoid crisp classes and ensure a smooth transition between the preference and indifference. This allowed then to integrate uncertainty in the knowledge of the exact class limits. Finally, four classes of regeneration suitability were obtained. These classes are good, medium, low and very low suitability and which represent 17.40%, 40.18%, 34.84% and 4.28% of the forest area respectively.

Simulation and experimental study of aspect ratio limitation in Fresnel zone plates for hard-x-ray optics.

For acquiring high-contrast and high-brightness images in hard-x-ray optics, Fresnel zone plates with high aspect ratios (zone height/zone width) have been constantly pursued. However, knowledge of aspect ratio limits remains limited. This work explores the achievable aspect ratio limit in polymethyl methacrylate (PMMA) by electron-beam lithography (EBL) under 100 keV, and investigates the lithographic factors for this limitation. Both Monte Carlo simulation and EBL on thick PMMA are applied to investigate the profile evolution with exposure doses over 100 nm wide dense zones. A high-resolution scanning electron microscope at low acceleration mode for charging free is applied to characterize the resultant zone profiles. It was discovered for what we believe is the first time that the primary electron-beam spreading in PMMA and the proximity effect due to extra exposure from neighboring areas could be the major causes of limiting the aspect ratio. Using the optimized lithography condition, a 100 nm zone plate with aspect ratio of 15/1 was fabricated and its focusing property was characterized at the Shanghai Synchrotron Radiation Facility. The aspect ratio limit found in this work should be extremely useful for guiding further technical development in nanofabrication of high-quality Fresnel zone plates.

Custom Implants: Manufacturing Principles and Determination of Psychological Price

This paper presents the basic principle for achieving a custom implant from biocompatible materials with the human body using Additive Manufacturing technologies. Due the fact that is a new product which will be introduced on the market, a marketing study was needed. This study presents also the mathematical, analytical and graphical modeling of the psychological price, for a custom implant type cranioplasty / hip prosthesis / spinal implant. The assessment of psychological price for a custom cranioplasty implant, that is not the object through curative Romanian health programs, bring relevant information on the knowledge of maximum and minimum limits that the purchasers, potential consumers, are willing to accept, so the price at which the proportion of consumers potential is the greatest.

The Brazilian Atlantic Forest: new findings, challenges and prospects in a shrinking hotspot

The Brazilian Atlantic Forest has been explored and degraded for more than 500 years (Morellato and Haddad 2000; Ribeiro et al. 2011). The forest fragments that still exist, except in protected areas such as National Reserves and Biological Reserves, are concentrated on the tops of mountains and/or steeper slopes, where agricultural activity is difficult or unfeasible, either for access or due to the generally low soil fertility (Moreno et al. 2003). This biome is, however, recognized as one of the 35 world hotspots for conservation priorities (Myers et al. 2000; Zachos and Habel 2011), and has even been referred as a ‘‘hottest hotspot’’ (Laurance 2009), ‘‘shrinking hotspot’’ (Ribeiro et al. 2011), or ‘‘top hotspot’’ (Eisenlohr et al. 2013). It is for this reason that a special issue is devoted to these forests here. Researchers have responded to this scenario, addressing important floristic and phytogeographic features of the Atlantic Forest vegetation, and producing works revealing major implications for biodiversity conservation (e.g. Oliveira-Filho and Fontes 2000; Marques et al. 2011; Werneck et al. 2011). These studies focused on tree species, the component on which there is far more available data than on most other plant types. However, in recent years, the number of surveys dealing with other growth forms has increased, along with the inclusion of life-forms other than trees in sampling protocols and floristic surveys. Including non-tree life-forms in investigations contributes to our knowledge of the geographic limits and the historical processes acting in the Atlantic Forest, in addition to providing a sounder basis for the development and technical planning of conservation policies.

Childhood long-term conditions in primary care: a qualitative study of practitioners' views.

Improving child health and wellbeing in England was the key focus of the Chief Medical Officer's Annual Report 2012, which recommended that all children with long-term conditions (LTCs) have a named GP responsible for their care. Little is known, however, about practitioners' views and experiences of supporting children with LTCs in primary care. To explore practitioners' views of supporting children with LTCs and their families in primary care. Qualitative interview study in primary care settings in South Yorkshire, England. Interviews explored practitioners' views and experiences of supporting children with asthma, cystic fibrosis, type 1 diabetes, and epilepsy. Interviews were audiotaped, transcribed verbatim, and analysed using the framework approach. Nineteen practitioners were interviewed: 10 GPs, five practice nurses, and four nurse practitioners. The GPs' clinical roles included prescribing and concurrent illness management; nurse practitioners held minor illness clinics; and practice nurses conduct asthma clinics and administer immunisations. GPs were coordinators of care and provided a holistic service to the family. GPs were often unsure of their role with children with LTCs, and did not feel they had overall responsibility for these patients. Confidence was dependent on experience; however, knowledge of GPs' own limits and accessing help were felt to be more important than knowledge of the condition. Primary care has a valuable role in the care of children with LTCs and their families. This study suggests that improving communication between services would clarify roles and help improve the confidence of primary care practitioners.

Impact of the Brine Disposal on Scapharca Subcrenata

Desalination of seawater accounts for a worldwide water production. Despite the many benefits the technology has to offer, concerns rise over potential negative impacts on the environment. We studied the effect of brine on scapharca subcrenata exposed to brine discharge from desalination plant. The results show that individuals grew best at temperature from 18°C to 20°C. When the temperature exceeded 20°C, the survival rate of the individuals decreased significantly. Therefore, it is necessary to develop effective means of reducing the negative influence of brine discharged on the marine environment. The knowledge of scapharca subcrenata limits can help not only to locate desalination plants but to design disposal devices.

The population biology of fungal invasions.

Fungal invasions are increasingly recognized as a significant component of global changes, threatening ecosystem health and damaging food production. Invasive fungi also provide excellent models to evaluate the generality of results based on other eukaryotes. We first consider here the reasons why fungal invasions have long been overlooked: they tend to be inconspicuous, and inappropriate methods have been used for species recognition. We then review the information available on the patterns and mechanisms of fungal invasions. We examine the biological features underlying invasion success of certain fungal species. We review population structure analyses, revealing native source populations and strengths of bottlenecks. We highlight the documented ecological and evolutionary changes in invaded regions, including adaptation to temperature, increased virulence, hybridization, shifts to clonality and association with novel hosts. We discuss how the huge census size of most fungi allows adaptation even in bottlenecked, clonal invaders. We also present new analyses of the invasion of the anther-smut pathogen on white campion in North America, as a case study illustrating how an accurate knowledge of species limits and phylogeography of fungal populations can be used to decipher the origin of invasions. This case study shows that successful invasions can occur even when life history traits are particularly unfavourable to long-distance dispersal and even with a strong bottleneck. We conclude that fungal invasions are valuable models to contribute to our view of biological invasions, in particular by providing insights into the traits as well as ecological and evolutionary processes allowing successful introductions.

Organic Reserves in ropical Grasses under Grazing

Inadequate management in recent times has been considered the main factor contributing to pasture degradation. A major reason for this is related to gross errors of grazing management as a consequence of the lack of knowledge of ecophysiological limits of forage. This review aimed to approach the importance of organic reserves for grasses under grazing. Therefore, the predominant effect of animal grazing is the reduction of leaf area which impacts on carbohydrate and nitrogen reserves and consequently the growth of tillers, leaves and roots. Grass growth after defoliation is related to organic reserves and rate of photosynthesis. The latter is affected by the level of canopy light interception of and by the reminiscent leaf area index. When grazing management is carried out with respect to the physiological limits of grass growth, the rate of dry matter accumulation will be quick and constant. In this aspect, grazing management consists of seeking an efficient balance between plant growth and consumption which will reflect on animal productivity. Therefore, a balance point among frequency and intensity of defoliation must be found to achieve greater animal production concerning the ecophysiological limits of the forage plants. So the challenge will be to find a balance between frequency and intensity of grazing to achieve greater production of animals respecting the eco-physiological limits of forage plants for each forage grass individually.

College students’ personal listening device usage and knowledge

Objective: To determine the usage and knowledge of safe limits on personal listening devices (PLD) among college students. Design: First, information on health history was collected. Second, microphone in real ear techniques determined eardrum to free-field correction factors. Third, hearing levels were evaluated and information gathered about knowledge of safe listening behaviors. Study sample: 180 college students participated in a one-hour session using their PLDs and earphones set to their personal preference. Results: Virtually all participants reported knowledge of hearing loss risk due to PLD use and accurately recognized their own PLD listening levels (p = .01) as either within or exceeding safe sound limits. Forty-four subjects listened at greater than 80-dBA free-field equivalent levels. Only 7% of these participants were aware of these hazardous levels and 15% of participants’ exposure surpassed free-field equivalent levels normalized to eight hours. Conclusions: Despite reported knowledge of hearing loss risk due to PLD use in virtually all college students, 1 in 4 were found to listen to their PLDs at free-field equivalent levels greater than 80-dBA, with 94% unaware of their potential risk. Further research is needed to provide accurate PLD listening information and evaluate the possibility of long term PLD intensities that surpass recommended safety levels on hearing loss in adults over time.

Reliability-Based Replacement of Polyethylene Gas Pipeline Networks

Lifetime management of underground pipelines is mandatory for safe hydrocarbon transmission and distribution systems. The use of high- density polyethylene tubes under pressure with the presence of external loading requires a reliability study to seek for the ideal operating conditions and the knowledge of the service limits, as reliability analysis is recognized as a powerful decision-making tool for risk-based design and maintenance. During the pipe life, the time-dependent phenomena, especially creep, take place, leading to a reduction of the pipe capacity. The reliability-based assessment of residual stress effects is carried out for underground polyethylene pipelines, under creep deterioration. This work is then applied to define optimal replacement for a gas distribution network, subjected to various operating conditions. The optimization of the total expected cost allows us to define the grouping strategy.

Detection of enterovirus in environmental waters: A new optimized method compared to commercial real-time RT-qPCR kits

Despite the progress in water and wastewater treatment technologies, waterborne diseases are still a major concern of public health. In the reported water-related outbreaks, viruses constitute one of the main causal agents. Enteroviruses are one of the most viruses monitored in water and are often used as an indicator of viral pollution. Isolation and identification of this virus are now regularly based on molecular tools. However published or commercial protocols for detection of these viruses in water are frequently lacking of validation processes and performance evaluation in such complex samples. A method for enterovirus detection in environmental water has been developed, its performance has been evaluated and compared with several commercial kits.The sensitivity of commercial methods in clinical samples, ranged between 89% and 100%, while the sensitivity in seeded environmental matrices fell between 16% and 91%. This method showed the best performance in environmental samples and was subsequently applied on surface and treated wastewater. The results showed the large dissemination of enteroviruses in an urbanized river. The results also emphasized the importance of good knowledge of the method's limits for its utilization in environmental samples in order to minimize false negatives and to avoid underestimating viral concentration.

Normal Values of Aortic Root Dimensions in Healthy Adults

The reported ranges of aortic root (AR) diameters are limited by small sample size, different measurement sites, and heterogeneous cohorts. The aim of this study was to explore the full spectrum of AR diameters by 2-dimensional transthoracic color Doppler echocardiography (TTE) in a large cohort of healthy adults. From June 2007 to December 2013, a total of 1,043 Caucasian healthy volunteers (mean age 44.7 ± 15.9 years, range 16 to 92 years, 503 men [48%]) underwent comprehensive TTE. TTE measurements of the AR were made at end-diastole in parasternal long-axis views at 4 levels: (1) annulus, (2) sinuses of Valsalva, (3) sinotubular junction, and (4) proximal ascending aorta. The absolute aortic diameters were significantly greater in men than in women at all levels, whereas body surface area-indexed aortic diameters were greater in women (p = 0.0001). No significant gender differences were registered for sinuses of Valsalva and sinotubular junction to annulus diameter ratios (p = 0.9), whereas ascending aorta to annulus diameter ratio was higher in women (p = 0.0001). There was a straight correlation between aortic diameters (absolute and indexed values), their ratios, and age in both genders (p = 0.0001). In conclusion, we provide the full range of AR diameters by TTE. Knowledge of upper physiological limits of aortic dimensions is mandatory to detect aorta dilatation, follow up the disease over time, and plan appropriate therapeutic interventions.

Osmotic tolerance limits of red blood cells from umbilical cord blood

Effective methods for long-term preservation of cord red blood cells (RBCs) are needed to ensure a readily available supply of RBCs to treat fetal and neonatal anemia. Cryopreservation is a potential long-term storage strategy for maintaining the quality of cord RBCs for the use in intrauterine and neonatal transfusion. However, during cryopreservation, cells are subjected to damaging osmotic stresses during cryoprotectant addition and removal and freezing and thawing that require knowledge of osmotic tolerance limits in order to optimize the preservation process. The objective of this study was to characterize the osmotic tolerance limits of cord RBCs in conditions relevant to cryopreservation, and compare the results to the osmotic tolerance limits of adult RBCs. Osmotic tolerance limits were determined by exposing RBCs to solutions of different concentrations to induce a range of osmotic volume changes. Three treatment groups of adult and cord RBCs were tested: (1) isotonic saline, (2) 40% w/v glycerol, and (3) frozen–thawed RBCs in 40% w/v glycerol. We show that cord RBCs are more sensitive to shrinkage and swelling than adult RBCs, indicating that osmotic tolerance limits should be considered when adding and removing cryoprotectants. In addition, freezing and thawing resulted in both cord and adult RBCs becoming more sensitive to post-thaw swelling requiring that glycerol removal procedures for both cell types ensure that cell volume excursions are maintained below 1.7 times the isotonic osmotically active volume to attain good post-wash cell recovery. Our results will help inform the development of optimized cryopreservation protocol for cord RBCs.

Sonography of the ankle.

The idea for this special number of Journal of Ultrasound arose from the Editor in chief of the journal, Ferdinando Draghi, and myself as a result of our longstanding friendship and previous publication in 2012 of a monothematic musculoskeletal number written by Italian authors and French speaking authors of the SIMS (Societe Imagerie Musculosqueletique). We choose the ankle and foot region since, because of the superficial position of most of their structures, it can be optimally explored by ultrasound (US). All the tendons, most of the nerves and vessels of this region can be accurately assessed, statically and dynamically, when using a high-definition modern US equipment by a well-trained examiner. Essential prerequisites for successful assessment include in depth knowledge of the normal anatomy and variations, realization of the US examination based on clinical findings and knowledge of intrinsic limits of US. The first article describes the sonographic anatomy of the ankle. Following articles deal with US appearance of a wide variety of pathologic conditions including ankle impingement syndrome, mid-portion Achilles tendon injury, tibialis anterior muscle and tendon disorders, peroneal tendon tear and, finally, evaluation of hindfoot disorders. All the articles have been written by well-renowned sonologits including not only radiologists but also clinicians (orthopedic surgeons and family medicine doctors). Authors are from Europe (Italy, France and England) and also from North America (USA and Canada) thus reflecting the widespread diffusion of Journal of Ultrasound. The articles were written with an effort to help the readers in their every day US practice. We hope you will appreciate our effort during scanning your next ankle and foot region! Have a good lecture.

Modeling Practical Performance Limits of Photoelectrochemical Water Splitting Based on the Current State of Materials Research

Photoelectrochemical (PEC) water splitting is a means to store solar energy in the form of hydrogen. Knowledge of practical limits for this process can help researchers assess their technology and guide future directions. We develop a model to quantify loss mechanisms in PEC water splitting based on the current state of materials research and calculate maximum solar-to-hydrogen (STH) conversion efficiencies along with associated optimal absorber band gaps. Various absorber configurations are modeled considering the major loss mechanisms in PEC devices. Quantitative sensitivity analyses for each loss mechanism and each absorber configuration show a profound impact of both on the resulting STH efficiencies, which can reach upwards of 25 % for the highest performance materials in a dual stacked configuration. Higher efficiencies could be reached as improved materials are developed. The results of the modeling also identify and quantify approaches that can improve system performance when working with imperfect materials.

Evaluating single-scale and/or non-planar diagrams by differential equations

We apply a recently suggested new strategy to solve differential equations for Feynman integrals. We develop this method further by analyzing asymptotic expansions of the integrals. We argue that this allows the systematic application of the differential equations to single-scale Feynman integrals. Moreover, the information about singular limits significantly simplifies finding boundary constants for the differential equations. To illustrate these points we consider two families of three-loop integrals. The first are form-factor integrals with two external legs on the light cone. We introduce one more scale by taking one more leg off-shell, $p_2^2\neq 0$. We analytically solve the differential equations for the master integrals in a Laurent expansion in dimensional regularization with $\epsilon=(4-D)/2$. Then we show how to obtain analytic results for the corresponding one-scale integrals in an algebraic way. An essential ingredient of our method is to match solutions of the differential equations in the limit of small $p_2^2$ to our results at $p_2^2\neq 0$ and to identify various terms in these solutions according to expansion by regions. The second family consists of four-point non-planar integrals with all four legs on the light cone. We evaluate, by differential equations, all the master integrals for the so-called $K_4$ graph consisting of four external vertices which are connected with each other by six lines. We show how the boundary constants can be fixed with the help of the knowledge of the singular limits. We present results in terms of harmonic polylogarithms for the corresponding seven master integrals with six propagators in a Laurent expansion in $\epsilon$ up to weight six.

Prediction of Wear Behaviour of Almg1sicu Hybrid MMC Using Taguchi with Grey Rational Analysis

In this paper, investigation focuses on preparing hybrid metal matrix composites of AlMg1SiCu alloy as base material by incorporating 9% SiC and varying 3 to 9% of graphite particulates varying insteps of 3 by vortex method. The wear and frictional properties of metal matrix hybrid composites were studied by performing dry sliding wear test using pin on disc wear test apparatus as per ASTM standards G – 99. Experiments were conducted based on the plan of experiments generated through Taguchi's technique. A L9 Orthogonal array was selected for analysis of data. Investigation to find the influence of applied load, sliding speed and track diameter on wear rate as well as coefficient of friction during wearing process was carried out using ANOVA. A mathematical model has been made for all cases that were studied depending on the method of least squares which helps in foretelling about the wear rate through the knowledge of limits as a variable with fixing the other variables Objective of the model was chosen as smaller the better characteristics to analyses the dry sliding wear resistance. The parametric studies indicate that on increase in the percentage of reinforcement; wear rate and coefficient of friction decreases.

Visceral adiposity index: an indicator of adipose tissue dysfunction.

The Visceral Adiposity Index (VAI) has recently proven to be an indicator of adipose distribution and function that indirectly expresses cardiometabolic risk. In addition, VAI has been proposed as a useful tool for early detection of a condition of cardiometabolic risk before it develops into an overt metabolic syndrome. The application of the VAI in particular populations of patients (women with polycystic ovary syndrome, patients with acromegaly, patients with NAFLD/NASH, patients with HCV hepatitis, patients with type 2 diabetes, and general population) has produced interesting results, which have led to the hypothesis that the VAI could be considered a marker of adipose tissue dysfunction. Unfortunately, in some cases, on the same patient population, there is conflicting evidence. We think that this could be mainly due to a lack of knowledge of the application limits of the index, on the part of various authors, and to having applied the VAI in non-Caucasian populations. Future prospective studies could certainly better define the possible usefulness of the VAI as a predictor of cardiometabolic risk.