Special Characteristics (special + characteristic)

Distribution by Scientific Domains


Selected Abstracts


Upper Eyelid Full-Thickness Skin Graft in Facial Reconstruction

DERMATOLOGIC SURGERY, Issue 1 2005
Dogan Tuncali MD
Background The potentially available upper eyelid skin, as an alternative donor site, deserves more attention in clinical use. Objective The objective of this study was to prospectively evaluate the clinical behavioral characteristics of upper eyelid full-thickness skin grafts in facial reconstruction. Methods Sixteen patients who concluded the 12-month follow-up period were included in the study. Graft dimensions were measured in place before the graft harvest. Defect sizes were measured following lesion excision and postgrafting. Graft sizes were measured postoperatively at 1, 3, 6, and 12 months. Results The largest and smallest grafts were 46 × 22 mm and 40 × 15 mm (average 43.1 × 19.3 mm) in size, respectively. The largest and smallest defect dimensions were 33 × 23 mm and 17 × 9 mm (average 22.6 × 15.6 mm), respectively. The average postgrafting size was 21.1 × 14.6 mm. Grafts and donor sites healed very well. Generally, an acceptable to good texture and color match was observed beyond 6 months. Wound bed contraction was not observed beyond the first month (p < .05). Conclusion Special characteristics of hairless skin, good color and texture matching, and inconspicuous and hidden donor scar make the upper eyelid a good alternative donor site for small- to medium-sized facial skin defects. The main disadvantages that limit its clinical use are the age of the patient, a lack of adnexal structures, comparatively limited sun exposure, and possible insufficient thickness, especially when deep defects are of concern. DOGAN TUNCALI, MD, LEVENT ATES, MD, AND GÜRCAN ASLAN, MD, HAVE INDICATED NO SIGNIFICANT INTEREST WITH COMMERCIAL SUPPORTERS. [source]


Development and implementation of new educational concepts in a dental curriculum

EUROPEAN JOURNAL OF DENTAL EDUCATION, Issue 1 2007
H. W. Kersten
Abstract, The Academic Centre for Dentistry Amsterdam introduced a fully renewed 5-year dental curriculum in September 2003. In this article, the educational principles and didactic choices that form the basis of the curriculum development are presented and attention is given to the process of development and the implementation strategy that constitute such an important part of the success of introducing a new curriculum. Special characteristics of the new curriculum are the clinical training practice, professional conduct, the elective profiles and academic education. In clinical practice, groups of students from different levels run a group practice in which they learn to work together, delegate tasks, solve clinical problems and apply evidence-based dentistry. In the new curriculum students learn to conduct themselves as professionals. In the third and in the fifth year, students choose an elective profile oriented, respectively, on research and on clinical knowledge and skills. Academic education is an important spearhead in this curriculum in which students not only learn why research is important to dentistry but also how dentists can use research to their own benefit. In development and implementation, a stepwise approach was used in which as many people as logistically possible were involved. [source]


Comedication related to comorbidities: a study in 1203 hospitalized patients with severe psoriasis

BRITISH JOURNAL OF DERMATOLOGY, Issue 5 2008
S. Gerdes
Summary Background, Psoriasis is a common dermatological disorder characterized by an immune-mediated chronic inflammation which is associated with a variety of other diseases commonly referred to as comorbidities. The treatments for these diseases may interfere with the course and the treatment of psoriasis. Little is known on the general drug intake of patients with psoriasis. Objectives, To gain more insight into the general drug intake of patients with severe psoriasis. A correlation of comedication to respective diseases could lead to a better knowledge of comorbidities. Methods, Data on demographics, comedication and comorbidities from 1203 patients with severe psoriasis in Germany were analysed. As a control group data from 7099 subjects from the German National Health Survey 1998 were used. Results, Patients with severe psoriasis are receiving significantly more different systemic drugs on average than the general population, with the most prominent difference in multidrug treatment. Drugs used in the treatment of arterial hypertension, diabetes mellitus and other diseases of the metabolic syndrome as well as oral anticoagulants and anticonvulsant agents showed the greatest differences. Special characteristics of antihypertensive drug treatments could be determined. Conclusions, The data obtained in this study provide the basis for an improved management of patients with psoriasis. Knowledge of existing comedication and comorbidities may lead to the ability to treat psoriasis and comorbidities at the same time more safely and to use possible synergistic effects. [source]


Handwritten Thai Character Recognition Using Fourier Descriptors and Genetic Neural Networks

COMPUTATIONAL INTELLIGENCE, Issue 3 2002
Pisit Phokharatkul
This article presents a method to solve the rotated and scaling character recognition problem using Fourier descriptors and genetic neural networks. The contours of character image are extracted and separated between the outer contour and inner or loop contours. The loop contours are a special characteristic of Thai characters, called the head of the character. The special features of Thai characters (loop contours) are used at the rough classification stage, and Fourier descriptors with genetic neural networks are used at the fine classification stage. The Fourier descriptors detect the outer contour of a character and it is fed to network. These features are recognized by a multilayer neural network. Genetic algorithms (GAs) are utilized to help compute the weights of the neural network optimally and reduce uncertain states in the neural networks output. Experimental results have shown that the combination of the Fourier descriptors with genetic neural networks, loop features, and local curvature charateristics of similar characters are powerful tools for successfully classifying Thai characters. The recognition rate by this method is 99.12% for 1200 examples of handwritten Thai words (a total of 13,500 characters) written by 60 persons. [source]


The common patterns of nature

JOURNAL OF EVOLUTIONARY BIOLOGY, Issue 8 2009
S. A. FRANK
Abstract We typically observe large-scale outcomes that arise from the interactions of many hidden, small-scale processes. Examples include age of disease onset, rates of amino acid substitutions and composition of ecological communities. The macroscopic patterns in each problem often vary around a characteristic shape that can be generated by neutral processes. A neutral generative model assumes that each microscopic process follows unbiased or random stochastic fluctuations: random connections of network nodes; amino acid substitutions with no effect on fitness; species that arise or disappear from communities randomly. These neutral generative models often match common patterns of nature. In this paper, I present the theoretical background by which we can understand why these neutral generative models are so successful. I show where the classic patterns come from, such as the Poisson pattern, the normal or Gaussian pattern and many others. Each classic pattern was often discovered by a simple neutral generative model. The neutral patterns share a special characteristic: they describe the patterns of nature that follow from simple constraints on information. For example, any aggregation of processes that preserves information only about the mean and variance attracts to the Gaussian pattern; any aggregation that preserves information only about the mean attracts to the exponential pattern; any aggregation that preserves information only about the geometric mean attracts to the power law pattern. I present a simple and consistent informational framework of the common patterns of nature based on the method of maximum entropy. This framework shows that each neutral generative model is a special case that helps to discover a particular set of informational constraints; those informational constraints define a much wider domain of non-neutral generative processes that attract to the same neutral pattern. [source]


Special considerations for haematology patients in relation to end-of-life care: Australian findings

EUROPEAN JOURNAL OF CANCER CARE, Issue 2 2007
P. MCGRATH bsocwk, senior research fellow
Recent haematology clinical guidelines recommend that palliative care specialists should have central roles in haemato-oncology teams. However, the available research evidence indicates there are presently significant obstacles to the integration of palliative care in haematology. The following discussion presents findings from an Australian study designed to address the problems associated with lack of referral of haematology patients to the palliative system through the development of a best-practice model for end-of-life care for these diagnostic groups. The preliminary step in the development of such a model is to document the factors that denote the special characteristics of the end-of-life stage of haematological conditions and their treatments. This article presents the list of special considerations from a nursing perspective, including issues associated with the high-tech nature of treatments, the speed of change to a terminal event, the need for blood products and possibility of catastrophic bleeds, the therapeutic optimism based on a myriad of treatment options and the clinical indices of the terminal trajectory. The nursing insights provide an important foundation for building a practical, patient-centred model for terminal care in haematology. [source]


Modified methodology for computing interference in LEO satellite environments

INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING, Issue 6 2003
Raúl Chávez Santiago
Abstract Computing interference is very important in satellite networks design in order to assure the electromagnetic compatibility (EMC) with other radiocommunication systems. There are different methods to compute interference in geostationary (GEO) satellite systems including conventional methods using link budget equations and alternate methods such as increase in noise temperature. However, computing interference in low earth orbit (LEO) systems represents a different problem. Due to the special characteristics of this kind of orbits, the elevation angle at any site changes continuously over time, meaning a time dependent change of the propagation path length between an interfering transmitter and an interfered-with receiver, and of the discrimination provided by the transmitting and/or the receiving antenna. Thus, conventional interference prediction methods developed for fixed links must be adapted to the case of LEO systems. To overcome this problem a mathematical model that characterizes the path length variations by an average value obtained from the probability density function of the varying distance between an interfering transmitter and an interfered- with receiver is proposed in this paper. This average path length enables the use of conventional link budget methods to reduce the computation time for the evaluation of interference in LEO satellite environments. Two practical examples show the possible applications of the proposed model. Copyright © 2003 John Wiley & Sons, Ltd. [source]


The European Union as a Protagonist to the United States on Climate Change

INTERNATIONAL STUDIES PERSPECTIVES, Issue 1 2006
JOHN VOGLER
The European Union (EU) has established itself as the moving force in the development of the international climate-change regime. By proceeding with the ratification of the Kyoto Protocol and building its own carbon emissions trading system, it has directly confronted the United States. Contemporary commentaries on the politics of climate change center upon the conflict between the EU and the U.S., but the precise nature of the EU as a protagonist remains elusive. It is neither a state nor an orthodox international organization but it can be regarded as an actor. This article investigates what it means for the EU to be an actor and develops a conceptualization based upon presence, opportunity, and capability. This is applied to the analysis of how the Union became an actor in climate-change politics, and its special characteristics, strengths, and vulnerabilities. The final part of the article then proceeds to consider the differences between the European actor and the United States over the development of the climate-change regime. [source]


Genetic structure and differentiation of 12 African Bos indicus and Bos taurus cattle breeds, inferred from protein and microsatellite polymorphisms

JOURNAL OF ANIMAL BREEDING AND GENETICS, Issue 1 2005
E.M. Ibeagha-Awemu
Summary Level of genetic differentiation, gene flow and genetic structuring of nine Bos indicus and three Bos taurus cattle breeds in Cameroon and Nigeria were estimated using the genetic information from 16 microsatellite, five blood protein and seven milk protein markers. The global heterozygote deficit across all populations (Fit) amounted to 11.7% (p < 0.001). The overall significant (p < 0.001) deficit of heterozygotes because of inbreeding within breeds (Fis) amounted to 6.1%. The breeds were moderately differentiated (Fst = 6%, p < 0.001) with all loci except CSN1S2 contributing significantly to the Fst value. The 12 populations belong to two genetic clusters, a zebu and a taurine cluster. While inferred sub-clusters within the taurine group corresponded extremely well to predefined breed categorizations, no real sub-clusters, corresponding to predefined breeds, existed within the zebu cluster. With the application of prior population information, cluster analysis achieved posterior probabilities from 0.962 to 0.994 of correctly assigning individuals to their rightful populations. High gene flow was evident between the zebu populations. Positive and negative implications of the observed genetic structure of the breeds on their development, improvement and conservation are discussed. The study shows that the breeds are threatened by uncontrolled breeding and therefore are at risk to become genetically uniform in the future. This situation can be avoided by putting in place effective breeding and management measures aimed at limiting uncontrolled mating between the breeds and to preserve special characteristics, genetic as well as breed biodiversity. The first step towards realizing these goals might be to geographically demarcate the breeds. [source]


Hydrogen bonding strength,measures based on geometric and topological parameters,

JOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 1 2004
awomir Janusz Grabowski
Abstract Different methods of estimating H-bond strength are presented. The studies are based on the results of MP2/6,311++G** calculations and the binding energies are corrected for the basis set superposition error (BSSE). The wavefunctions were further applied to localize bond critical points and ring critical points. The characteristics based on the Bader theory are also applied as indicators and measures of hydrogen bonding. This study compares samples of different compounds. The H-bond strength measures such as the proton,acceptor distance (H···Y), the length of the proton donating bond, the electron density at H···Y bond critical point, the H-bond energy and others are analysed. The case of the intramolecular hydrogen bonding is also analysed, and its special characteristics are given. Copyright © 2003 John Wiley & Sons, Ltd. [source]


Polymer-Derived Ceramics: 40 Years of Research and Innovation in Advanced Ceramics

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 7 2010
Paolo Colombo
Preceramic polymers were proposed over 30 years ago as precursors for the fabrication of mainly Si-based advanced ceramics, generally denoted as polymer-derived ceramics (PDCs). The polymer to ceramic transformation process enabled significant technological breakthroughs in ceramic science and technology, such as the development of ceramic fibers, coatings, or ceramics stable at ultrahigh temperatures (up to 2000°C) with respect to decomposition, crystallization, phase separation, and creep. In recent years, several important advances have been achieved such as the discovery of a variety of functional properties associated with PDCs. Moreover, novel insights into their structure at the nanoscale level have contributed to the fundamental understanding of the various useful and unique features of PDCs related to their high chemical durability or high creep resistance or semiconducting behavior. From the processing point of view, preceramic polymers have been used as reactive binders to produce technical ceramics, they have been manipulated to allow for the formation of ordered pores in the meso-range, they have been tested for joining advanced ceramic components, and have been processed into bulk or macroporous components. Consequently, possible fields of applications of PDCs have been extended significantly by the recent research and development activities. Several key engineering fields suitable for application of PDCs include high-temperature-resistant materials (energy materials, automotive, aerospace, etc.), hard materials, chemical engineering (catalyst support, food- and biotechnology, etc.), or functional materials in electrical engineering as well as in micro/nanoelectronics. The science and technological development of PDCs are highly interdisciplinary, at the forefront of micro- and nanoscience and technology, with expertise provided by chemists, physicists, mineralogists, and materials scientists, and engineers. Moreover, several specialized industries have already commercialized components based on PDCs, and the production and availability of the precursors used has dramatically increased over the past few years. In this feature article, we highlight the following scientific issues related to advanced PDCs research: (1) General synthesis procedures to produce silicon-based preceramic polymers. (2) Special microstructural features of PDCs. (3) Unusual materials properties of PDCs, that are related to their unique nanosized microstructure that makes preceramic polymers of great and topical interest to researchers across a wide spectrum of disciplines. (4) Processing strategies to fabricate ceramic components from preceramic polymers. (5) Discussion and presentation of several examples of possible real-life applications that take advantage of the special characteristics of preceramic polymers. Note: In the past, a wide range of specialized international symposia have been devoted to PDCs, in particular organized by the American Ceramic Society, the European Materials Society, and the Materials Research Society. Most of the reviews available on PDCs are either not up to date or deal with only a subset of preceramic polymers and ceramics (e.g., silazanes to produce SiCN-based ceramics). Thus, this review is focused on a large number of novel data and developments, and contains materials from the literature but also from sources that are not widely available. [source]


Characterization of xylanolytic bacteria present in the bract phyllosphere of the date palm Phoenix dactylifera

LETTERS IN APPLIED MICROBIOLOGY, Issue 2 2007
R. Rivas
Abstract Aims:, Despite the interest of phyllosphere microbiology, no studies have addressed the bacteria present in bract phyllosphere, an ecosystem that has special characteristics in palm trees because the dry bracts remain on the plant until pruning and may contain polymer-degrading bacteria involved in plant degradation. Therefore, the aim of this work was to characterize xylanolytic bacteria isolated from palm bract phyllosphere. Methods and Results:, Twelve xylanolytic strains were isolated and characterized by phenotypic features and complete sequencing of 16S rRNA gene. The results showed that the isolates were phenotypically and genotypically diverse. Gram-positive isolates were classified into genus Paenibacillus some of them belonging to hitherto undescribed species of this genus. Gram-negative isolates were classified into genera Pseudomonas and Acinetobacter. Conclusions:, The results of this work confirm the complexity of the bacterial populations present in phyllospheric ecosystems and suggest that bacteria involved in plant degradation are present at the early degradation steps of this process in dry palm tree bracts. Significance and Impact of the Study:, This is the first study on bract phyllospheric bacteria able to hydrolyse vegetal polymers and offers a new perspective in the search of unexplored sources of xylanase-producing strains. [source]


Microbial status in seawater and coastal sediments during pre- and post-tsunami periods in the Bay of Bengal, India

MARINE ECOLOGY, Issue 3 2006
Subramani Ramesh
Abstract Tsunami, the natural disaster, which occurred on December 26, 2004 in the Indian Ocean, caused severe damage to mankind in the coastal areas. Total loss of life and economic loss because of this disaster have been estimated by various agencies but its effect on microbial density has not been probed. With our previous results on microbial populations in four locations of the Chennai coast of the Bay of Bengal, India in the pre-tsunami period, the change in microbial populations was studied after the tsunami at regular intervals in the same locations. Coastal sediment and seawater samples were collected from four different locations after 5,10 h and thereafter at intervals of every 7 days up to 28 days post-tsunami. Bacteria, fungi and actinomycetes were isolated from the marine samples by serial dilution on respective media. Before the tsunami, the bacterial population was higher in seawater samples than the sediments, whereas fungi and actinomycetes were recorded only in the sediments. The microbial population remarkably increased 5,10 h post-tsunami in all the marine samples irrespective of the location. However, it slowly declined in the subsequent days and became similar to that of the population recorded before the tsunami. The population of gram-positive bacteria increased whereas the gram-negative bacterial population decreased after the tsunami. Further, populations of pathogenic bacteria such as coliform and vibrios did not increase after the tsunami. It has been observed that the increase in populations of bacteria and actinomycetes even after 28 days of tsunami may be due to the introduction of foreign microorganisms that developed the ability to survive in the extreme environment by exhibiting special characteristics such as pigmentation and production of exopolysaccharides. [source]


Synthesis and characterization of hydrogels containing biodegradable polymers

POLYMER INTERNATIONAL, Issue 7 2008
Adina Cretu
Abstract BACKGROUND: Amphiphilic block and graft copolymers constitute a very interesting class of polymers with potential for biomedical applications, due to their special characteristics, which derive from the combination of properties of hydrophilic and hydrophobic moieties. In this work, the synthesis and biodegradation of poly(2-hydroxyethyl methacrylate)- graft -poly(L -lactide) are studied. RESULTS: The graft copolymers were synthesized using the macromonomer technique. In a first step, methacryloyl-terminated poly(L -lactide) macromonomers were synthesized in a wide molecular weight range using different catalysts. Subsequently, these macromonomers were copolymerized with 2-hydroxyethyl methacrylate in order to obtain a graft copolymer. These new materials resemble hydrogel scaffolds with a biodegradable component. The biodegradation was studied in hydrolytic and enzymatic environments. The influence of different parameters (molecular weight, crystallinity, ratio between hydrophilic and hydrophobic components) on the degradation rate was investigated. CONCLUSION: Based on this study it will be possible to tailor the release properties of biodegradable materials. In addition, the materials will show good biocompatibility due to the hydrophilic poly(2-hydroxyethyl methacrylate) hydrogel scaffold. This kind of material has potential for many applications, like controlled drug-delivery systems or biodegradable implants. Copyright © 2008 Society of Chemical Industry [source]


Benchmarking competitiveness in transition economies

THE ECONOMICS OF TRANSITION, Issue 2 2001
Clifford Zinnes
This paper constructs an indicator for the current level of international competitiveness of countries in transition. We find that Hungary is the most competitive country in the group while Turkmenistan is the least. Competitiveness measurement, in our view, is a way to use uniform criteria to gauge the extent to which a country makes use of various levers to promote sustained improvements in its well-being. We construct our measure of competitiveness drawing upon both the popular literature on competitiveness as well as modern economic theory. The approach acknowledges the importance of synergies between firms, markets, and government and, above all, the crucial role of institutions. Our choice of variables stresses the special characteristics of transition countries. By bringing to bear all the existing data on these countries, together with new survey data collected for the purpose, we are able to go beyond the mere ranking of countries to decompose the sources of competitiveness into their constituent parts. This allows policy makers to identify areas where their countries are lagging behind relative to other countries in their region. Our indicator is also compatible with the Global Competitiveness Report series categories, thus allowing us to benchmark transition countries against the rest of the world. JEL classification: C82, O47, O57, P27, P52. [source]


Olfactory Neural Cells: An Untapped Diagnostic and Therapeutic Resource

THE LARYNGOSCOPE, Issue 4 2002
Christopher Perry MBBS, FRACS
Abstract Objective This is an overview of the cellular biology of upper nasal mucosal cells that have special characteristics that enable them to be used to diagnose and study congenital neurological diseases and to aid neural repair. Study Design After mapping the distribution of neural cells in the upper nose, the authors' investigations moved to the use of olfactory neurones to diagnose neurological diseases of development, especially schizophrenia. Olfactory-ensheathing glial cells (OEGs) from the cranial cavity promote axonal penetration of the central nervous system and aid spinal cord repair in rodents. The authors sought to isolate these cells from the more accessible upper nasal cavity in rats and in humans and prove they could likewise promote neural regeneration, making these cells suitable for human spinal repair investigations. Methods The schizophrenia-diagnosis aspect of the study entailed the biopsy of the olfactory areas of 10 schizophrenic patients and 10 control subjects. The tissue samples were sliced and grown in culture medium. The ease of cell attachment to fibronectin (artificial epithelial basement membrane), as well as the mitotic and apoptotic indices, was studied in the presence and absence of dopamine in those cell cultures. The neural repair part of the study entailed a harvesting and insertion of first rat olfactory lamina propria rich in OEGs between cut ends of the spinal cords and then later the microinjection of an OEG-rich suspension into rat spinal cords previously transected by open laminectomy. Further studies were done in which OEG insertion was performed up to 1 month after rat cord transection and also in monkeys. Results Schizophrenic patients' olfactory tissues do not easily attach to basement membrane compared with control subjects, adding evidence to the theory that cell wall anomalies are part of the schizophrenic "lesion" of neurones. Schizophrenic patient cell cultures had higher mitotic and apoptotic indices compared with control subjects. The addition of dopamine altered these indices enough to allow accurate differentiation of schizophrenics from control patients, leading to, possibly for the first time, an early objective diagnosis of schizophrenia and possible assessment of preventive strategies. OEGs from the nose were shown to be as effective as those from the olfactory bulb in promoting axonal growth across transected spinal cords even when added 1 month after injury in the rat. These otherwise paraplegic rats grew motor and proprioceptive and fine touch fibers with corresponding behavioral improvement. Conclusions The tissues of the olfactory mucosa are readily available to the otolaryngologist. Being surface cells, they must regenerate (called "neurogenesis"). Biopsy of this area and amplification of cells in culture gives the scientist a "window to the developing brain," including early diagnosis of schizophrenia. The "Holy Grail" of neurological disease is the cure of traumatic paraplegia and OEGs from the nose promote that repair. The otolaryngologist may become the necessary partner of the neurophysiologist and spinal surgeon to take the laboratory potential of paraplegic cure into the day-to-day realm of clinical reality. [source]


Post-summer heavy rainfall events in Southeast Brazil associated with South Atlantic Convergence Zone

ATMOSPHERIC SCIENCE LETTERS, Issue 1 2010
Kellen Carla Lima
Abstract Heavy rainfall events (HREs) in the post-summer month of March in Southeast Brazil cause disasters such as floods, mudslides and landslides, mainly because the soil becomes saturated by February. Forty-five years of rainfall data show that heavy rainfall frequency increases again in the month of March. The composite anomaly fields of the atmospheric circulation during and before HREs associated with the formation of South Atlantic Convergence Zone show some special characteristics that may be used as a guide for early warning. The convergence of moisture flux in the troposphere over the region grows 40% during the 48 h before the HRE in March. Copyright © 2010 Royal Meteorological Society [source]


Teilsicherheitsfaktoren für die Berechnung von Großkraftwerken

BETON- UND STAHLBETONBAU, Issue 7 2010
Simon Glowienka Dr.-Ing.
Normen, Vorschriften, Richtlinien; Berechnungs- und Bemessungsverfahren Abstract Die Baustrukturen von Großkraftwerken werden in Deutschland u. a. auf Basis der VGB-Richtlinie R 602 U berechnet und bemessen. In dieser Richtlinie sind unter Berücksichtigung der Besonderheiten des Großkraftwerksbaus Einwirkungen und Teilsicherheitsfaktoren definiert. Während die Lasten auf diese Randbedingungen abgestimmt wurden, hat man die Teilsicherheitsfaktoren auf der Lastseite aus der DIN 1055-100 entnommen und lediglich die Kombinationsbeiwerte angepasst. Diese Sicherheitsbeiwerte tragen jedoch den speziellen Randbedingungen eines Kraftwerks oder Schwerindustriebaus nur bedingt Rechnung. Im Rahmen des Beitrags werden die Teilsicherheitsbeiwerte auf der Einwirkungsseite , insbesondere für das Konstruktionseigengewicht , für die Bemessung von Stahlbetonteilen vor diesem Hintergrund kritisch diskutiert und ein optimierter, wissenschaftlich abgesicherter Vorschlag unterbreitet. Partial Safety Factors for the Design of Power Plants In Germany power plants are designed in accordance to VGB regulation R 602 U. In this code load actions and partial safety factors are applied taking the special characteristics of power plants into consideration. The actions are defined regarding these circumstances, however the safety coefficients are assumed according to DIN 1055-100 and only the combination coefficients are adjusted. However it has to be recognized that the partial safety factors in DIN 1055-100 are calibrated for building constructions and thus do not consider the specialities of power plants in an adequate manner. In this paper the partial safety factors for the design of power plants and other heavy industry buildings are discussed for structural concrete elements and a scientific based optimized approach for the safety factor for dead load is presented. [source]


A Comparison of the Soil Water, Nutrient Status, and Litterfall Characteristics of Tropical Heath and Mixed-Dipterocarp Forest Sites in Brunei,

BIOTROPICA, Issue 1 2000
Jonathan A. Moran
ABSTRACT Two of the main hypotheses to explain the distribution and special characteristics of tropical heath forest are nutrient and water limitation. A study was undertaken to investigate both factors on two sites under tropical heath forest (Badas Forest Reserve) and mixed-dipterocarp forest (Andulau Forest Reserve) in Brunei. Soil water potentials were monitored at depths of 20, 50, and 90 cm over wet and dry periods for five months at each site. The results showed the mixed-dipterocarp forest site to be drier at 50 cm depth compared to the tropical heath forest site. There was no significant difference in water potentials between sites at 20 or 90 cm. Nutrient concentrations in the soil solution were monitored at the same depths over a seven-month period at the same sites. A 12-month litterfall study was also undertaken to monitor nutrient returns from the canopy at each site. The results of both studies suggest that the tropical heath forest site is poorer in nitrogen, but richer in calcium, than the mixed-dipterocarp forest site. The results for phosphorus are less clear, but do not suggest that its limitation is a significant factor at the tropical heath forest site compared to the mixed-dipterocarp forest site. Phosphorus and magnesium concentrations in the soil solution showed a strong positive correlation with sliding 30-day rainfall totals at both sites. [source]


The impact of childhood chronic neurological diseases on Greek families

CHILD: CARE, HEALTH AND DEVELOPMENT, Issue 1 2005
M. Tzoufi
Abstract Background, Although the impact of childhood chronic neurological diseases (CND) on patients' psychological well-being has been increasingly addressed, little attention has been given to the influence of these conditions on family members and family functioning. The purpose of the present study was to investigate the family characteristics of Greek children suffering from CND. Methods, A total of 52 parents of children with CND were studied by using the Family Environmental Scale (FES), the Family Burden Scale, the General Health Questionnaire (GHQ-28) and a questionnaire on the knowledge of their children's illness, their coping strategies and their satisfaction with our services. During the same period, 30 parents of hospitalized children for common paediatric illnesses completed the FES. In both groups social and demographic features were registered. Appropriate statistical processes were applied to compare the above-mentioned family groups and to study the differences between the families of children with epilepsy (n = 37) and the families of children with other CND (n = 15). Results, Parents of children with CND discuss their problems less freely, talk less openly around home, score highly on FES subscale of Conflict and, pay more attention to ethical and religious issues and values. Furthermore, the families of children with other CND were more burdened regarding the financial state and the health status of other family members in comparison with families of children with epilepsy. In addition, families of children with epilepsy were more involved in social and recreational activities, appeared to be more knowledgeable on the availability of help in critical conditions and were more satisfied with rendered medical services, in comparison with families of children with other CND. Conclusion, These preliminary findings provide important information concerning the special characteristics of Greek families of children suffering from CND, which may prove especially helpful in organizing specific support services. [source]