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Thorough Understanding (thorough + understanding)
Selected AbstractsReview: physical chemistry of solid dispersionsJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 12 2009Sandrien Janssens Abstract Objectives With poorly soluble drug candidates emerging in the drug discovery pipeline, the importance of the solid dispersion formulation approach is increasing. This strategy includes complete removal of drug crystallinity, and molecular dispersion of the poorly soluble compound in a hydrophilic polymeric carrier. The potential of this technique to increase oral absorption and hence bioavailability is enormous. Nevertheless, some issues have to be considered regarding thermodynamic instability, as well in supersaturated solutions that are formed upon dissolution as in the solid state. Key findings After a brief discussion on the historical background of solid dispersions and their current role in formulation, an overview will be given on the physical chemistry and stability of glass solutions as they form supersaturated solutions, and during their shelf life. Conclusions Thorough understanding of these aspects will elicit conscious evaluation of carrier properties and eventually facilitate rational excipient selection. Thus, full exploitation of the solid dispersion strategy may provide an appropriate answer to drug attrition due to low aqueous solubility in later stages of development. [source] An educational tool for controlling of SRMCOMPUTER APPLICATIONS IN ENGINEERING EDUCATION, Issue 4 2008Tuncay Yigit Abstract This article introduces an educational tool for a switched reluctance motor (SRM) drive system. It is prepared for undergraduate and graduate level students. Classical PI and Genetic PI controllers are used in SRM drive system. The Genetic PI controller was applied to the speed loop, replacing the classical PI controller. The tool software was implemented using C++ Builder on a PC. It has flexible structure and graphical interface. The students can be easily establishing a thorough understanding of both classical PI and genetic PI controller for a SRM drive system. The education tool allowed the student to interact with the SRM drive system and it is using controllers. Then it is responses on a dynamic and instantaneous basis under different operating conditions. © 2008 Wiley Periodicals, Inc. Comput Appl Eng Educ 16: 268,279, 2008; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae20148 [source] Teaching, Exploring, Learning,Developing Tutorials for In-Class Teaching and Self-LearningCOMPUTER GRAPHICS FORUM, Issue 4 2007S. Beckhaus Abstract This paper presents an experience report on a novel approach for a course on intermediate and advanced computer graphics topics. The approach uses Teachlet Tutorials, a combination of traditional seminar,type teaching with interactive exploration of the content by the audience, plus development of self-contained tutorials on the topic. In addition to a presentation, an interactive software tool is developed by the students to assist the audience in learning and exploring the topic's details. This process is guided through set tasks. The resulting course material is developed for two different contexts: (a) for classroom presentation and (b) as an interactive, self-contained, self-learning tutorial. The overall approach results in a more thorough understanding of the topic both for the student teachers as well as for the class participants. In addition to detailing the Teachlet Tutorial approach, this paper presents our experiences implementing the approach in our Advanced Computer Graphics course and presents the resultant projects. Most of the final Teachlet Tutorials were surprisingly good and we had excellent feedback from the students on the approach and course. [source] Introduction to Flap Movement: Reconstruction of Five Similar Nasal Defects Using Different FlapsDERMATOLOGIC SURGERY, Issue 2005Elbert H. Chen MD Background. There are several options for closure of a given surgical defect after tumor extirpation is confirmed. Flap reconstruction is one of these options. Objective. The purpose of this article is to introduce the three basic types of flap movement: advancement, rotation, and transposition. Methods. Five similar defects located on the nasal sidewall were repaired, each using a different flap design. Results. The optimal flap design for a given defect on a particular patient is based on the answers to a series of questions: Where is the available tissue reservoir? How can tissue be mobilized from the reservoir to cover the defect? How do the resulting tension vectors affect critical structures? Where are the final incision lines? Conclusion. Many factors must be evaluated before determining a method of reconstruction. Flap reconstruction requires a thorough understanding of anatomy and tissue movement. [source] Soft tissue augmentation 2006: filler fantasyDERMATOLOGIC THERAPY, Issue 3 2006Arnold William Klein ABSTRACT:, As an increasing number of patients seek esthetic improvement through minimally invasive procedures, interest in soft tissue augmentation and filling agents is at an all-time high. One reason for this interest is the availability of botulinum toxin type A, which works superbly in the upper face. The rejuvenation of the upper face has created much interest in injectable filling agents and implant techniques that work equally well in the restoration of the lower face. One of the central tenets of soft tissue augmentation is the concept of the three-dimensional face. The youthful face has a soft, full appearance, as opposed to the flat, pulled, two-dimensional look often achieved by more traditional surgical approaches. Injectable filling agents can augment and even at times, replace pulling. Additionally, with the lip as the focal center of the lower face, subtle lip enhancement is here to stay, and is in fact, the number one indication for injectable fillers. Moreover, minimally invasive soft tissue augmentation offers cosmetic enhancement without the cost and recovery time associated with more invasive procedures. As more and more physicians take interest in minimally invasive surgery, courses in cosmetic surgery techniques are becoming increasingly popular at the medical meetings of many specialties. Today, physicians have a much larger armamentarium of techniques and materials with which to improve facial contours, ameliorate wrinkles, and provide esthetic rejuvenation to the face. For a substance or device to be amenable for soft tissue augmentation in the medical community, it must meet certain criteria. It must have both a high "use" potential, producing cosmetically pleasing results with a minimum undesirable reactions, and have a low abuse potential in that widespread or incorrect or indiscriminate use would not result in significant morbidity. It must be nonteratogenic, noncarcinogenic, and nonmigratory. In addition, the agent must provide predictable, persistent correction through reproducible implantation techniques. Finally, the substance, agent or device must be approved by the U.S. Food and Drug Administration, which assures purity, safety, and accessibility, as well as much-needed information regarding use. Having a thorough understanding of the filling agents available, their indications and contraindications, as well as having thorough knowledge of implant technique are vital in providing the patient with an esthetically pleasing result. [source] Root canal morphology and its relationship to endodontic proceduresENDODONTIC TOPICS, Issue 1 2005Frank J. Vertucci The hard tissue repository of the human dental pulp takes on numerous configurations and shapes. A thorough knowledge of tooth morphology, careful interpretation of angled radiographs, proper access preparation and a detailed exploration of the interior of the tooth are essential prerequisites for a successful treatment outcome. Magnification and illumination are aids that must be utilized to achieve this goal. This article describes and illustrates tooth morphology and discusses its relationship to endodontic procedures. A thorough understanding of the complexity of the root canal system is essential for understanding the principles and problems of shaping and cleaning, for determining the apical limits and dimensions of canal preparations, and for performing successful microsurgical procedures. [source] Overview of the use of antimicrobials for the treatment of bacterial infections in horsesEQUINE VETERINARY EDUCATION, Issue 8 2008E. F. Haggett Summary Use of antimicrobial drugs is central to the treatment of primary and secondary bacterial infection in horses. When selecting an antimicrobial to treat confirmed or suspected bacterial infection multiple factors should be considered, including: the likely infectious agent; distribution and dosage of selected drugs; mechanisms of action; and potential side effects. Many of these issues will be covered in subsequent articles in this series. The aim of this paper is to aid the clinician in the rational selection of antimicrobials by reviewing the mode of action, spectrum of activity, pharmacokinetics, pharmacodynamics, indications and potential side effects of the main classes of antimicrobial drugs. Extralabel use of drugs is common in veterinary medicine due to a lack of licensed products. This increases the importance of a thorough understanding of antimicrobials and their possible adverse effects. [source] Comparison of dental licensure, specialization and continuing education in five countriesEUROPEAN JOURNAL OF DENTAL EDUCATION, Issue 4 2002Titus Schleyer Dental practice and education are becoming more globalized. Greater practitioner and patient mobility, the free flow of information, increasingly global standards of care and new legal and economic frameworks (such as European Union [EU] legislation) are forcing a review of dental licensure, specialization and continuing education systems. The objective of this study was to compare these systems in Canada, France, Germany, the UK and the US. Representatives from the five countries completed a 29-item questionnaire, and the information was collated and summarized qualitatively. Statutory bodies are responsible for licensing and re-licensing in all countries. In the two North American countries, this responsibility rests with individual states, and in Europe, with the countries themselves, mainly governed by the legal framework of the EU. In some countries, re-licensure requires completion of continuing education credits. Approaches to dental specialization tend to differ widely with regard to definition of specialities, course and duration of training, training facilities, and accreditation of training programmes. In most countries, continuing education is provided by a number of different entities, such as universities, dental associations, companies, institutes and private individuals. Accreditation and recognition of continuing education is primarily process-driven, not outcome-orientated. Working towards a global infrastructure for dental licensing, specialization and continuing education depends on a thorough understanding of the international commonalities and differences identified in this article. [source] Functional Adhesive Surfaces with "Gecko" Effect: The Concept of Contact Splitting,ADVANCED ENGINEERING MATERIALS, Issue 5 2010Marleen Kamperman Abstract Nature has developed reversibly adhesive surfaces whose stickiness has attracted much research attention over the last decade. The central lesson from nature is that "patterned" or "fibrillar" surfaces can produce higher adhesion forces to flat and rough substrates than smooth surfaces. This paper critically examines the principles behind fibrillar adhesion from a contact mechanics perspective, where much progress has been made in recent years. The benefits derived from "contact splitting" into fibrils are separated into extrinsic/intrinsic contributions from fibril deformation, adaptability to rough surfaces, size effects due to surface-to-volume ratio, uniformity of stress distribution, and defect-controlled adhesion. Another section covers essential considerations for reliable and reproducible adhesion testing, where better standardization is still required. It is argued that, in view of the large number of parameters, a thorough understanding of adhesion effects is required to enable the fabrication of reliable adhesive surfaces based on biological examples. [source] A plaidoyer for cutaneous enzymology: our view of some important unanswered questions on the contributions of selected key enzymes to epidermal homeostasisEXPERIMENTAL DERMATOLOGY, Issue 7 2008John M. Wood Abstract:, This review highlights the importance of enzymology, a field of great neglect in current cutaneous biology research. It was therefore the aim by using selected examples of epidermal enzymes and their action including some open questions to demonstrate the importance of this area. Clearly a thorough understanding of basic knowledge in this field is needed which in turn offers a plethora of innovative research projects for a curious mind. Moreover, in order to gain the closest understanding to the truth instead of generating esoteric results, emphasis is put forward on a holistic view utilizing a combination of modern and sometimes old methods to get the answer. Last but not least the bench work is only useful for the welfare of our patients if we can apply our basic knowledge. [source] Water availability controls microbial temperature responses in frozen soil CO2 productionGLOBAL CHANGE BIOLOGY, Issue 11 2009MATS G. ÖQUIST Abstract Soil processes in high-latitude regions during winter are important contributors to global carbon circulation, but our understanding of the mechanisms controlling these processes is poor and observed temperature response coefficients of CO2 production in frozen soils deviate markedly from thermodynamically predicted responses (sometimes by several orders of magnitude). We investigated the temperature response of CO2 production in 23 unfrozen and frozen surface soil samples from various types of boreal forests and peatland ecosystems and also measured changes in water content in them after freezing. We demonstrate that deviations in temperature responses at subzero temperatures primarily emanates from water deficiency caused by freezing of the soil water, and that the amount of unfrozen water is mainly determined by the quality of the soil organic matter, which is linked to the vegetation cover. Factoring out the contribution of water limitation to the CO2 temperature responses yields response coefficients that agree well with expectations based on thermodynamic theory concerning biochemical temperature responses. This partitioning between a pure temperature response and the effect of water availability on the response of soil CO2 production at low temperatures is crucial for a thorough understanding of low-temperature soil processes and for accurate predictions of C-balances in northern terrestrial ecosystems. [source] Opportunities for independent living using direct payments in mental healthHEALTH & SOCIAL CARE IN THE COMMUNITY, Issue 2 2006Helen Spandler PhD Abstract Mental health service users have yet to reap the benefits of greater choice, control and independent living, which direct payments have facilitated in other groups of community care users, particularly people with physical disabilities. To redress this imbalance a national pilot to promote direct payments to people with mental health needs in five local authority sites across England was set up and evaluated. The evaluation used a multi-method approach incorporating both qualitative and quantitative data, including individual semi-structured interviews and group discussions with key stakeholders across the pilot sites. This article draws on findings from the pilot evaluation to provide a preliminary understanding of how applicable the independent living philosophy is to mental health and what opportunities direct payments offer for service users. When given the opportunity, service users were able to use direct payments creatively to meet a range of needs in ways which increased their choice, control and independence. This suggests that the benefits of greater independent living through direct payments may be realisable in mental health. However, a number of ways in which the principles of direct payments in mental health could be ,downgraded' were identified. The evaluation results indicate that a thorough understanding of the independent living philosophy needs to be developed in the context of mental health. [source] Specific role for acyl CoA:Diacylglycerol acyltransferase 1 (Dgat1) in hepatic steatosis due to exogenous fatty acids,HEPATOLOGY, Issue 2 2009Claudio J. Villanueva Nonalcoholic fatty liver disease, characterized by the accumulation of triacylglycerols (TGs) and other lipids in the liver, often accompanies obesity and is a risk factor for nonalcoholic steatohepatitis and fibrosis. To treat or prevent fatty liver, a thorough understanding of hepatic fatty acid and TG metabolism is crucial. To investigate the role of acyl CoA:diacylglycerol acyltransferase 1 (DGAT1), a key enzyme of TG synthesis, in fatty liver development, we studied mice with global and liver-specific knockout of Dgat1. DGAT1 was required for hepatic steatosis induced by a high-fat diet and prolonged fasting, which are both characterized by delivery of exogenous fatty acids to the liver. Studies in primary hepatocytes showed that DGAT1 deficiency protected against hepatic steatosis by reducing synthesis and increasing the oxidation of fatty acids. In contrast, lipodystrophy (aP2-SREBP-1c436) and liver X receptor activation (T0901317), which increase de novo fatty acid synthesis in liver, caused steatosis independently of DGAT1. Pharmacologic inhibition of Dgat1 with antisense oligonucleotides protected against fatty liver induced by a high-fat diet. Conclusion: Our findings identify a specific role for hepatic DGAT1 in esterification of exogenous fatty acids and indicate that DGAT1 contributes to hepatic steatosis induced by this mechanism. (HEPATOLOGY 2009.) [source] Tomography of temperature gradient metamorphism of snow and associated changes in heat conductivityHYDROLOGICAL PROCESSES, Issue 18 2004Martin Schneebeli Abstract Temperature gradient metamorphism is one of the dominant processes changing the structure of natural dry snow. The structure of snow regulates the thermal and mechanical properties. Physical models and numerical simulations of the evolution of the snow cover require a thorough understanding of the interplay between structure and physical properties. The structure of snow and the heat conductivity were measured simultaneously without disturbance in a miniature snow breeder. The structure was measured by microtomography, and heat conductivity by measuring heat fluxes and temperatures. A temperature gradient from 25 to 100 K m,1 was applied to the snow. The snow density range of the samples varied from 150 to 500 kg m,3. The density in the observed volume remained constant during the experiments under temperature gradient conditions. The structure was analysed with respect to the size of typical ice structures and air pores, specific surface area, curvature and anisotropy of the ice matrix. The temporal changes in structure and heat conductivity are compared. The heat conductivity changed by as much as twice its initial value, caused by changes in structure and texture, but not due to changes in density. This shows the enormous importance of structure in the evolution of the heat conductivity. The observed changes are not in good agreement with the current understanding of the metamorphic process, because heat conductivity increased during temperature gradient metamorphism, instead of the expected decrease due to a shrinking of the bonds. We also observed a plateau in the evolution of the heat conductivity coefficient, which indicates a quasi-steady state of the structural evolution with respect to thermophysical properties of snow. Copyright © 2004 John Wiley & Sons, Ltd. [source] The Elusive Path to Cartilage RegenerationADVANCED MATERIALS, Issue 32-33 2009Ernst B. Hunziker Abstract Numerous attempts have been made to develop an efficacious strategy for the repair of articular cartilage. These endeavors have been undaunted, if not spurred, by the challenge of the task and by the largely disappointing outcomes in animal models. Of the strategies that have been lately applied in a clinical setting, the autologous-chondrocyte-transplantation technique is the most notorious example. This methodology, which was prematurely launched on the clinical scene, was greeted with enthusiasm and has been widely adopted. However, a recent prospective and randomized clinical trial has revealed the approach to confer no advantage over conventional microfracturing. Why is the repair of articular cartilage such a seemingly intractable problem? The root of the evil undoubtedly lies in the tissue's poor intrinsic healing capacity. But the failure of investigators to tackle the biological stumbling blocks systematically rather than empirically is hardly a less inauspicious circumstance. Moreover, it is a common misbelief that the formation of hyaline cartilage per se suffices, whereas to be durable and functionally competent, the tissue must be fully mature. An appreciation of this necessity, coupled with a thorough understanding of the postnatal development of articular cartilage, would help to steer investigators clear of biological cul-de-sacs. [source] Bioaccessibility studies of ferro-chromium alloy particles for a simulated inhalation scenario: A comparative study with the pure metals and stainless steelINTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT, Issue 3 2010Klara Midander Abstract The European product safety legislation, REACH, requires that companies that manufacture, import, or use chemicals demonstrate safe use and high level of protection of their products placed on the market from a human health and environmental perspective. This process involves detailed assessment of potential hazards for various toxicity endpoints induced by the use of chemicals with a minimum use of animal testing. Such an assessment requires thorough understanding of relevant exposure scenarios including material characteristics and intrinsic properties and how, for instance, physical and chemical properties change from the manufacturing phase, throughout use, to final disposal. Temporary or permanent adverse health effects induced by particles depend either on their shape or physical characteristics, and/or on chemical interactions with the particle surface upon human exposure. Potential adverse effects caused by the exposure of metal particles through the gastrointestinal system, the pulmonary system, or the skin, and their subsequent potential for particle dissolution and metal release in contact with biological media, show significant gaps of knowledge. In vitro bioaccessibility testing at conditions of relevance for different exposure scenarios, combined with the generation of a detailed understanding of intrinsic material properties and surface characteristics, are in this context a useful approach to address aspects of relevance for accurate risk and hazard assessment of chemicals, including metals and alloys and to avoid the use of in vivo testing. Alloys are essential engineering materials in all kinds of applications in society, but their potential adverse effects on human health and the environment are very seldom assessed. Alloys are treated in REACH as mixtures of their constituent elements, an approach highly inappropriate because intrinsic properties of alloys generally are totally different compared with their pure metal components. A large research effort was therefore conducted to generate quantitative bioaccessibility data for particles of ferro-chromium alloys compared with particles of the pure metals and stainless steel exposed at in vitro conditions in synthetic biological media of relevance for particle inhalation and ingestion. All results are presented combining bioaccessibility data with aspects of particle characteristics, surface composition, and barrier properties of surface oxides. Iron and chromium were the main elements released from ferro-chromium alloys upon exposure in synthetic biological media. Both elements revealed time-dependent release processes. One week exposures resulted in very small released particle fractions being less than 0.3% of the particle mass at acidic conditions and less than 0.001% in near pH-neutral media. The extent of Fe released from ferro-chromium alloy particles was significantly lower compared with particles of pure Fe, whereas Cr was released to a very low and similar extent as from particles of pure Cr and stainless steel. Low release rates are a result of a surface oxide with passive properties predominantly composed of chromium(III)-rich oxides and silica and, to a lesser extent, of iron(II,III)oxides. Neither the relative bulk alloy composition nor the surface composition can be used to predict or assess the extent of metals released in different synthetic biological media. Ferro-chromium alloys cannot be assessed from the behavior of their pure metal constituents. Integr Environ Assess Manag 2010;6:441,455. © 2009 SETAC [source] Response of small rodents to manipulations of vegetation height in agro-ecosystemsINTEGRATIVE ZOOLOGY (ELECTRONIC), Issue 1 2008Jens JACOB Abstract Some small mammal populations require human interference to conserve rare or threatened species or to minimize adverse effects in plant production. Without a thorough understanding about how small rodents behave in their environment and consideration of how they react to management efforts, management will not be optimal. Social behavior, spatial and temporal activity patterns, predator avoidance and other behavioral responses can affect pest rodent management. Some of these behavioral patterns and their causes have been well studied. However, their impact on pest rodent management, especially for novel management approaches, is not always clear. Habitat manipulation occurs necessarily through land use and intentionally to reduce shelter and food availability and to increase predation pressure on rodents. Rodents often respond to decreased vegetation height with reduced movements and increased risk sensitivity in their feeding behavior. This seems to result mainly from an elevated perceived predation risk. Behavioral responses may lessen the efficacy of the management because the desired effects of predators might be mediated. It remains largely unknown to what extent such responses can compensate at the population level for the expected consequences of habitat manipulation and how population size and crop damage are affected. It is advantageous to understand how target and non-target species react to habitat manipulation to maximize the management effects by appropriate techniques, timing and spatial scale without causing unwanted effects at the system level. [source] Defocused Wide-field Imaging Unravels Structural and Temporal Heterogeneity in Complex SystemsADVANCED MATERIALS, Issue 10-11 2009Peter Dedecker Abstract Today's miniature devices and biological systems share the fact that their dynamics and properties cannot be understood in terms of macroscopic concepts, but require a thorough understanding of the nanoscale structuring. This structuring is often very heterogeneous, both in time and in space, and is difficult or impossible to resolve with traditional approaches. In this Progress Report, we will discuss how single-molecule microscopy,and defocused wide-field imaging in particular,can be used to shed light on these phenomena. [source] A novel approach to the analysis of distributed shear banding in polymer blendsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 5 2003K. G. W. Pijnenburg Abstract The toughness of glassy polymers can be enhanced by blending with rubber particles. The consensus is that this toughening is due to massive plastic deformation of the matrix that takes place once the particles have cavitated. Micromechanical studies of regular stackings of particles in a polymer matrix have provided much insight into the localized plastic flow in blends at the microscale of individual particles (or voids, once cavitated). Even some steps towards macroscopic constitutive models have been made. However, at intermediate length scales (i.e. larger than several particles, but smaller than the scale at which the material may be regarded as homogeneous) the situation is unclear. It is this length scale that becomes important around crack tips, for example, where a thorough understanding of the toughening effect has to be derived from. In this paper, we therefore present a novel approach to the analysis of distributed shear banding in polymer,rubber blends. A coarse-grain description, in which much of the morphology is retained but the local shear banding is idealized into ,shear surfaces', will enable us to analyse ensembles with large numbers of particles. The parameters of this model will be validated with results from detailed cell analyses. Copyright © 2003 John Wiley Sons, Ltd. [source] Optimisation of hard pretzel productionINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 3 2007Ni Yao Summary Absence of a thorough understanding of the baking conditions on hard pretzel quality has resulted in considerable loss of production and on productivity. Baking time, oven zone 1 temperature, drying time and kiln drying temperature were identified as important factors affecting pretzel quality in modern pretzel production, from a total of eleven factors following a screening experiment design. A central composite circumscribe design was then employed to optimise these four variables. The test for lack of fit was not significant (P < 0.05) for the responses, except for colour a* values. The analysis of variance of the responses indicated that models explained 99%, 91% and 87% variability for moisture content, ,Eab and pasting time, respectively. The four variables were optimised when pretzel moisture content, ,Eab and pasting time were considered simultaneously using desirability function approach. Validation experiment results revealed that the two most important qualities of pretzel, moisture content and ,Eab could be reliably predicted. [source] Scapular development from the neonatal period to skeletal maturity: A preliminary studyINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 5 2007C. Rissech Abstract An understanding of the basic growth rates and patterns of development for each element of the human skeleton is important for a thorough understanding and interpretation of data in all areas of skeletal research. Yet surprisingly little is known about the detailed ontogenetic development of many bones, including the scapula. With the intention of describing the changes that accompany postnatal ontogeny in the scapula and algorithms to predict sub-adult age at death, this communication examines the development of the scapula through nine measurements (3 from the glenoidal area, 4 from the body and 2 related to the spinous process) by polynomial regression. Data were collected from 31 of the individuals that comprise the Scheuer Collection, which is housed at the University of Dundee (Scotland). Four of the derived mathematical curves (scapular length, infra- and suprascapular height and spine length) displayed linear growth, whilst three (maximum length of the glenoid mass, acromial width and scapular width) were best expressed by a second-degree polynomial and two (maximum and middle diameter of the glenoidal surface) by a third-degree polynomial. All single measurements proved useful in the prediction of age at death, although derived indices proved to be of limited value. In particular, scapular width, suprascapular height and acromial width showed reliable levels of age prediction until late adolescent years. Copyright © 2007 John Wiley & Sons, Ltd. [source] Use of vibrational spectroscopy to study protein and DNA structure, hydration, and binding of biomolecules: A combined theoretical and experimental approachINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 5 2006K. J. Jalkanen Abstract We report on our work with vibrational absorption, vibrational circular dichroism, Raman scattering, Raman optical activity, and surface-enhanced Raman spectroscopy to study protein and DNA structure, hydration, and the binding of ligands, drugs, pesticides, or herbicides via a combined theoretical and experimental approach. The systems we have studied systematically are the amino acids (L -alanine, L -tryptophan, and L -histidine), peptides (N -4271 acetyl L -alanine N,-methyl amide, N -acetyl L -tryptophan N,-methyl amide, N -acetyl L -histidine N,-methyl amide, L -alanyl L -alanine, tri- L -serine, N -acetyl L -alanine L -proline L -tyrosine N,-methyl amide, Leu-enkephalin, cyclo-(gly- L -pro)3, N -acetyl (L -alanine)nN,-methyl amide), 3-methyl indole, and a variety of small molecules (dichlobenil and 2,6-dochlorobenzamide) of relevance to the protein systems under study. We have used molecular mechanics, the SCC-DFTB, SCC-DFTB+disp, RHF, MP2, and DFT methodologies for the modeling studies with the goal of interpreting the experimentally measured vibrational spectra for these molecules to the greatest extent possible and to use this combined approach to understand the structure, function, and electronic properties of these molecules in their various environments. The application of these spectroscopies to biophysical and environmental assays is expanding, and therefore a thorough understanding of the phenomenon from a rigorous theoretical basis is required. In addition, we give some exciting and new preliminary results which allow us to extend our methods to even larger and more complex systems. The work presented here is the current state of the art to this ever and fast changing field of theoretical spectroscopic interpretation and use of VA, VCD, Raman, ROA, EA, and ECD spectroscopies. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2006 [source] Observing freeway ramp merging phenomena in congested trafficJOURNAL OF ADVANCED TRANSPORTATION, Issue 2 2007Majid Sarvi This work conducts a comprehensive investigation of traffic behavior and characteristics during freeway ramp merging under congested traffic conditions. On the Tokyo Metropolitan Expressway, traffic congestion frequently occurs at merging bottleneck sections, especially during heavy traffic demand. The Tokyo Metropolitan Expressway public corporation, generally applies different empirical strategies to increase the flow rate and decrease the accident rate at the merging sections. However, these strategies do not rely either on any behavioral characteristics of the merging traffic or on the geometric design of the merging segments. There have been only a few research publications concerned with traffic behavior and characteristics in these situations. Therefore, a three-year study is undertaken to investigate traffic behavior and characteristics during the merging process under congested situations. Extensive traffic data capturing a wide range of traffic and geometric information were collected using detectors, videotaping, and surveys at eight interchanges in Tokyo Metropolitan Expressway. Maximum discharged flow rate from the head of the queue at merging sections in conjunction with traffic and geometric characteristics were analyzed. In addition, lane changing maneuver with respect to the freeway and ramp traffic behaviors were examined. It is believed that this study provides a thorough understanding of the freeway ramp merging dynamics. In addition, it forms a comprehensive database for the development and implementation of congestion management techniques at merging sections utilizing Intelligent Transportation System. [source] Good Deaths, Bad Deaths, and Preferences for the End of Life: A Qualitative Study of Geriatric OutpatientsJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 9 2002Elizabeth K. Vig MD OBJECTIVES: Patient involvement in decision-making has been advocated to improve the quality of life at the end of life. Although the size of the oldest segment of the population is growing, with greater numbers of older adults facing the end of life, little is known about their preferences for the end of life. This study aimed to explore the attitudes of older adults with medical illness about the end of life, and to investigate whether current values could be extended to end-of-life preferences. DESIGN: Descriptive study with interviews using open- and closed-ended questions. SETTING: Patients attending two university-affiliated geriatric clinics were interviewed in a private conference room near the clinic they attended or in their homes. PARTICIPANTS: Sixteen older men and women identified by their physicians as having nonterminal heart disease or cancer. MEASUREMENTS: The interview contained open-ended questions such as: "What are the most important things in your life right now?" and "What would you consider a good/bad death?" The interview also contained closed-ended questions about symptoms, quality of life, and health status. Additional questions elicited preferences for the end of life, such as location of death and the presence of others. The open-ended questions were tape-recorded, transcribed, and analyzed using qualitative methods. The closed-ended questions were analyzed using descriptive statistics. RESULTS: Patients with heart disease and cancer provided similar responses. Participants' views about good deaths, bad deaths, and end-of-life scenarios were heterogeneous. Each participant voiced a unique combination of themes in describing good and bad deaths. Because each participant described a multifaceted view of a good death, for instance, no theme was mentioned by even half of the participants. Participants provided differing explanations for why given themes contributed to good deaths. Currently valued aspects of life were not easily translated into end-of-life preferences. For example, although the majority of participants identified their family as being important, many gave reasons why they did not want their family members present when they died. CONCLUSIONS: Because of the heterogeneity of views and the difficulty in inferring end-of-life preferences from current values, older adults should be asked not only questions about general values, but also specific questions about their end-of-life choices and the reasons for these choices. A thorough understanding of an individual's end-of-life preferences may help health professionals working with older adults develop patient-centered care plans for the end of life. [source] The responses of floodplain primary production to flood frequency and timingJOURNAL OF APPLIED ECOLOGY, Issue 1 2001A.I. Robertson Summary 1,River regulation and abstraction have dramatically altered the natural flow regime of many rivers world-wide, but experimental investigations of the biological effects are infrequent. In the mid-region of the Murray River, Australia, river regulation has reduced the frequency and duration of spring floods and increased the frequency of summer floods. We used controlled floods (treatments: no floods, spring floods, summer floods and spring + summer floods) to determine how the growth of river red gum Eucalyptus camaldulensis trees, aquatic macrophytes and biofilms varied with the seasonal timing and frequency of flooding. 2,After 6 years of controlled flooding, above-ground net production of wood by river red gum trees was equal and greatest in plots receiving spring + summer floods and summer floods (mean 496 g m,2 year,1). Production was significantly lower in plots receiving spring floods or no controlled floods, which had similar rates of production (mean 330 g m,2 year,1). 3,During 2 years of measurement in wetlands created by flooding, production and species richness of aquatic macrophyte were both greater in spring than in summer floods. The history of flood frequency at any experimental site did not affect macrophyte production or species richness. The aquatic macrophyte community in shallow regions of wetlands differed significantly with the seasonal timing of floods, but not flood frequency. 4,The accumulation of chlorophyll a and total mass of biofilm on wood surfaces in wetlands created by flooding were greater in spring (mean chlorophyll a, 0·88 µg cm,2; mean mass, 0·066 mg cm,2) than in summer floods (mean chlorophyll a, 0·09 µg cm,2; mean mass, 0·034 mg cm,2). The history of flood frequency at any experimental site did not affect accumulation of either the autotrophic or heterotrophic components of biofilms. 5,Spring flooding, while not as beneficial for tree growth, is critical for the growth of wetland macrophytes, the maintenance of macrophyte species richness, and favours better development of autotrophic biofilms. Maintenance of both the timber harvest and wetland conservation values of these floodplains will require the return of more natural flood flows in the spring period. Restoration of floodplain rivers requires a thorough understanding of the relationships between ecological functions and the natural flow regime. [source] Constructing life-tables for the invasive maize pest Diabrotica virgifera virgifera (Col.; Chrysomelidae) in EuropeJOURNAL OF APPLIED ENTOMOLOGY, Issue 4 2006S. Toepfer Abstract:, The western corn rootworm (Diabrotica virgifera virgifera LeConte, Col.; Chrysomelidae) is an alien invasive species in Europe. It is a univoltine species with eggs that overwinter in the soil and larvae that hatch in spring. Three larval instars feed on maize roots, which can cause plant lodging and yield loss of economic importance. Adults emerge between mid-June and early August and can reduce yields through intensive silk feeding. In order to provide a thorough understanding of the population dynamics of this invasive pest species in the invaded European region, complete age specific life-tables were constructed in two maize fields in southern Hungary assessing the significance of natural mortality factors acting on D. v. virgifera populations. This information provides a rational basis for devising sustainable integrated pest management programmes, in particular, by enabling the identification of vulnerable pest age intervals for the timely application of various management tools. The life-table for D. v. virgifera in Europe resulted in a total mortality of about 99% from the egg stage in the autumn to the emergence of adult females in the following year (KTotal = 2.48), which is comparable with North America. The highest reduction of D. v. virgifera numbers resulted from the mortality in first instar larvae (94% marginal death rate) and from the unrealized fecundity (80%). However, only the variation in mortality between years can change the generational mortality and thus influence population growth. High variation in the marginal death rate between fields and years was found in the second and third instar larval stages, and in the overwintering egg stage. These mortality factors therefore have the potential to cause changes in the total generational mortality. Furthermore, the life-table suggested that a high fecundity could compensate for a high generational mortality and would lead to population increase. [source] Effect of die geometry on foaming behaviors of high-melt-strength polypropylene with CO2JOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2008Patrick C. Lee Abstract This article reports on a systematic study that was conducted to investigate the effects of die geometry (i.e., pressure and pressure drop rate) on the cell nucleation and growth behaviors of noncrosslinked high-melt-strength (HMS) polypropylene (PP) foams blown with supercritical CO2. The experimental results showed that the cellular morphologies of PP foams were sensitive to the die geometry. Furthermore, the initial expansion behavior of the foam extrudate at the die exit was recorded using a high-speed CCD camera. This enabled us to achieve a more thorough understanding of the effect of die geometry on both the initial expansion behavior and the final cellular morphology of HMS PP foams. The effect of die temperature on cell morphology was also studied. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci 2008 [source] Empirical tests of life-history evolution theory using phylogenetic analysis of plant demographyJOURNAL OF ECOLOGY, Issue 2 2010Jean H. Burns Summary 1. A primary goal of evolutionary ecology is to understand factors selecting for the diversity of life histories. Life-history components, such as time-to-reproduction, adult survivorship and fecundity, might differ among species because of variation in direct and indirect benefits of these life histories in different environments or might have lower-than-expected variability because of phylogenetic constraints. Here, we present a phylogenetic examination of demography and life histories using a data base of 204 terrestrial plant species. 2. Overall, statistical models without phylogeny were preferred to models with phylogeny for vital rates and elasticities, suggesting that they lacked phylogenetic signal and are evolutionarily labile. However, the effect of phylogeny was significant in models including sensitivities, suggesting that sensitivities exhibit greater phylogenetic signal than vital rates or elasticities. 3. Species with a greater age at first reproduction had lower fecundity, consistent with a cost of delayed reproduction, but only in some habitats (e.g. grassland). We found no evidence for an indirect benefit of delayed reproduction via a decrease in variation in fecundity with age to first reproduction. 4. The greater sensitivity and lower variation in survival than in fecundity was consistent with buffering of more important vital rates, as others have also found. This suggests that studies of life-history evolution should include survival, rather than only fecundity, for the majority of species. 5.Synthesis. Demographic matrix models can provide informative tests of life-history theory because of their shared construction and outputs and their widespread use among plant ecologists. Our comparative analysis suggested that there is a cost of delayed reproduction and that more important vital rates exhibit lower variability. The absolute importance of vital rates to population growth rates (sensitivities) exhibited phylogenetic signal, suggesting that a thorough understanding of life-history evolution might require an understanding of the importance of vital rates, not just their means, and the role of phylogenetic history. [source] Behaviour and ecology of the western corn rootworm (Diabrotica virgifera virgifera LeConte)AGRICULTURAL AND FOREST ENTOMOLOGY, Issue 1 2009Joseph L. Spencer Abstract 1,The western corn rootworm (WCR) is a historic pest with a legacy of resistance and behavioural plasticity. Its behaviour and nutritional ecology are important to rootworm management. The success of the most effective and environmentally benign rootworm management method, annual crop rotation, was based on an understanding of rootworm behaviour and host,plant relationships. Enthusiastic adoption of crop rotation, provided excellent rootworm management, but also selected for behavioural resistance to this cultural control. 2,Though well-studied, significant gaps in WCR biology remain. Understanding the topics reviewed here (mating behaviour, nutritional ecology, larval and adult movement, oviposition, alternate host use, and chemical ecology) is a starting point for adapting integrated pest management and insect resistance management (IRM) to an expanding WCR threat. A presentation of significant questions and areas in need of further study follow each topic. 3,The expansion of WCR populations into Europe exposes this pest to new environmental and regulatory conditions that may influence its behaviour and ecology. Reviewing the state of current knowledge provides a starting point of reference for researchers and pest management decision-makers in North America and Europe. 4,The trend toward increasing adoption of transgenic maize will place an increasing premium on understanding WCR behaviour. IRM plans designed to promote sustainable deployment of transgenic hybrids are grounded on assumptions about WCR movement, mating and ovipositional behaviour. Preserving the utility of new and old management options will continue to depend on a thorough understanding of WCR biology, even as the ecological circumstances and geography of WCR problems become more complex. [source] A speculative bubble in commodity futures prices?AGRICULTURAL ECONOMICS, Issue 1 2010Cross-sectional evidence Commitment's of traders; Index funds; Commodity futures markets Abstract Recent accusations against speculators in general and long-only commodity index funds in particular include: increasing market volatility, distorting historical price relationships, and fueling a rapid increase and decrease in the level of commodity prices. Some researchers have argued that these market participants,through their impact on market prices,may have inadvertently prevented the efficient distribution of food aid to deserving groups. Certainly, this result,if substantiated,would counter the classical argument that speculators make prices more efficient and thus improve the economic efficiency of the food marketing system. Given the very important policy implications, it is crucial to develop a more thorough understanding of long-only index funds and their potential market impact. Here, we review the criticisms (and rebuttals) levied against (and for) commodity index funds in recent U.S. Congressional testimonies. Then, additional empirical evidence is added regarding cross-sectional market returns and the relative levels of long-only index fund participation in 12 commodity futures markets. The empirical results provide scant evidence that long-only index funds impact returns across commodity futures markets. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||