Very Complex (very + complex)

Distribution by Scientific Domains


Selected Abstracts


An Approximate Bayesian Algorithm for Combining Forecasts,

DECISION SCIENCES, Issue 3 2001
Kim-Hung Li
Abstract In this paper we propose a consensus forecasting method based on a convex combination of individual forecast densities. The exact Bayesian updating of the convex combination weights is very complex and practically prohibitive. We propose a simple sequential updating alternative method based on function approximation. Several examples illustrate the method. [source]


The evolution of Chinese policies and governance structures on environment, energy and climate

ENVIRONMENTAL POLICY AND GOVERNANCE, Issue 3 2010
Stephen Tsang
Abstract Although a successor to the 1997 Kyoto Protocol has not yet materialized, the 2009 Copenhagen meeting underlined the importance of China in international debates on climate and energy. This is based not only on China's current climate emissions, but also on its expected energy use and economic growth. Within China, climate issues have, like environmental pollution more generally, received increasing government and societal attention, but so has energy , topics that relate to one other but also have different priorities and actor interests behind them. However, while climate change has become more prominent, as shown in the targets included in the current five-year plan, its institutional embeddedness in relation to particularly energy issues has received limited attention. This paper aims to help shed some light on how Chinese policies and governance structures on energy, climate and environment have evolved, particularly considering the roles of national and provincial authorities. Administrative structures and policy-making processes turn out to be very complex, with a range of units and bodies at different levels with distinct responsibilities as well as inter-linkages. Moreover, tensions and conflicts can be found regarding climate change and environmental policies on the one hand, and prevailing objectives to further economic development on the other. Energy policies serve the same economic goals, with climate change being most often operationalized in terms of energy conservation. Copyright © 2010 John Wiley & Sons, Ltd and ERP Environment. [source]


The Space Mission MIR'97: operational aspects

EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 12 2000
R. Ewald
Background A German astronaut visited the MIR space station between 10 February and 2 March 1997. Together with his Russian colleagues, he conducted a series of scientific investigations before, during and after his stay aboard the MIR station. Research performed during this flight was part of a global space life sciences programme and focused on metabolic homeostasis, fluid balance, calcium homeostasis and cardiovascular regulatory mechanisms. The main goal of the scientific experiments was to use this mission as a milestone to establish international networks of scientific collaboration using space research as a tool for focused research in respective fields. Thus, in most cases the results obtained from the astronaut complemented a series of results obtained on ground and from other flights. In other cases, they extended previous results and opened new fields for future research. Participants Human space flight with astronauts serving as operators and at the same time as test subjects is very complex. Many people, including mission control, a science management team, medical operations, ethics committees and a medical board, participated to harmonize the different requirements, thus making a maximal scientific outcome possible. Conclusion In summary, this space mission may be seen as a model for focused long-term multidisciplinary international research, and demonstrates that space medicine is no longer adventure but science. [source]


A heterogeneous computing system for data mining workflows in multi-agent environments

EXPERT SYSTEMS, Issue 5 2006
Ping Luo
Abstract: The computing-intensive data mining (DM) process calls for the support of a heterogeneous computing system, which consists of multiple computers with different configurations connected by a high-speed large-area network for increased computational power and resources. The DM process can be described as a multi-phase pipeline process, and in each phase there could be many optional methods. This makes the workflow for DM very complex and it can be modeled only by a directed acyclic graph (DAG). A heterogeneous computing system needs an effective and efficient scheduling framework, which orchestrates all the computing hardware to perform multiple competitive DM workflows. Motivated by the need for a practical solution of the scheduling problem for the DM workflow, this paper proposes a dynamic DAG scheduling algorithm according to the characteristics of an execution time estimation model for DM jobs. Based on an approximate estimation of job execution time, this algorithm first maps DM jobs to machines in a decentralized and diligent (defined in this paper) manner. Then the performance of this initial mapping can be improved through job migrations when necessary. The scheduling heuristic used considers the factors of both the minimal completion time criterion and the critical path in a DAG. We implement this system in an established multi-agent system environment, in which the reuse of existing DM algorithms is achieved by encapsulating them into agents. The system evaluation and its usage in oil well logging analysis are also discussed. [source]


Life-history strategies in freshwater macroinvertebrates

FRESHWATER BIOLOGY, Issue 9 2008
WILCO C. E. P. VERBERK
Summary 1Explaining spatial and temporal differences in species assemblages is a central aim of ecology. It requires a sound understanding of the causal mechanisms underlying the relationship of species with their environment. A species trait is widely acknowledged to be the key that links pattern and process, although the enormous variety of traits hampers generalization about which combination of traits are adaptive in a particular environment. 2In three steps, we used species traits to match species and environment, and chose lentic freshwater ecosystems to illustrate our approach. We first identified key environmental factors and selected the species traits that enable the organism to deal with them. Secondly, we investigated how investments in these traits are related (e.g. through trade-offs). Thirdly, we outlined 13 life-history strategies, based on biological species traits, their interrelations known from life-history theory and their functional implications. 3Species traits and environmental conditions are connected through life-history strategies, with different strategies representing different solutions to particular ecological problems. In addition, strategies may present an integrated response to the environment as they are based on many different traits and their interrelationships. The presence and abundance of (species exhibiting) different life-history strategies in a location may therefore give direct information about how a particular environment is experienced by the species present. 4Life-history strategies can be used to (i) explain differences in species assemblages either between locations or in different periods; (ii) compare waterbodies separated by large geographical distances, which may comprise different regional species pools or span species distribution areas and (iii) reduce often very complex, biodiverse assemblages into a few meaningful, easily interpretable relationships. [source]


Crustal structure of the Newfoundland rifted continental margin from constrained 3-D gravity inversion

GEOPHYSICAL JOURNAL INTERNATIONAL, Issue 2 2007
J. Kim Welford
ABSTRACT The rifting history of the Atlantic continental margin of Newfoundland is very complex and so far has been investigated at the crustal scale primarily with the use of 2-D seismic surveys. While informative, the results generated from these surveys cannot easily be interpreted in a regional sense due to their sparse sampling of the margin. A 3-D gravity inversion of the free air data over the Newfoundland margin allows us to generate a 3-D density anomaly model that can be compared with the seismic results and used to gain insight into regions lacking seismic coverage. Results of the gravity inversion show good correspondence with Moho depths from seismic results. A shallowing of the Moho to 12 km depth is resolved on the shelf at the northern edge of the Grand Banks, in a region poorly sampled by other methods. Comparisons between sediment thickness and crustal thickness show deviations from local isostatic compensation in locations which correlate with faults and rifting trends. Such insights must act as constraints for future palaeoreconstructions of North Atlantic rifting. [source]


Different methods for modelling the areal infiltration of a grass field under heavy precipitation

HYDROLOGICAL PROCESSES, Issue 7 2002
Bruno Merz
Abstract The areal infiltration behaviour of a grass field is studied using a data set of 78 sprinkler infiltration experiments. The analysis of the experimental data shows a distinct event dependency: once runoff begins, the final infiltration rate increases with increasing rainfall intensity. This behaviour is attributed to the effects of small-scale variability. Increasing rainfall intensity increases the ponded area and therefore the portion of the plot which infiltrates at maximum rate. To describe the areal infiltration behaviour of the grass field the study uses two different model structures and investigates different approaches for consideration of subgrid variability. It is found that the effective parameter approach is not suited for this purpose. A good representation of the observed behaviour is obtained by using a distribution function approach or a parameterization approach. However, it is not clear how the parameters can be derived for these two approaches without a large measurement campaign. The data analysis and the simulations show the great importance of considering the effects of spatial variability for the infiltration process. This may be significant even at a small scale for a comparatively homogeneous area. The consideration of heterogeneity seems to be more important than the choice of the model type. Furthermore, similar results may be obtained with different modelling approaches. Even the relatively detailed data set does not seem to permit a clear model choice. In view of these results it is questionable to use very complex and detailed simulation models given the approximate nature of the problem. Although the principle processes may be well understood there is a lack of models that represent these processes and, more importantly, there is a lack of techniques to measure and parameterize them. Copyright © 2002 John Wiley & Sons, Ltd. [source]


Seismic response of slopes subjected to incident SV wave by an improved boundary element approach

INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 10 2007
Behrouz Gatmiri
Abstract In this paper, an improved boundary element approach for 2D elastodynamics in time-domain is presented. This approach consists in the truncation of time integrations, based on the rapid decrease of the fundamental solutions with time. It is shown that an important reduction of the computation time as well as the storage requirement can be achieved. Moreover, for half-plane problems, the size of boundary element (BE) meshes and the computation time can be significantly reduced. The proposed approach is used to study the seismic response of slopes subjected to incident SV waves. It is found that large amplifications take place on the upper surface close to the slope, while attenuations are produced on the lower surface. The results also show that surface motions become very complex when the incident wavelength is comparable with the size of the slope or when the slope is steep. Copyright © 2006 John Wiley & Sons, Ltd. [source]


Effects of Differentially Time-Consuming Tests on Computer-Adaptive Test Scores

JOURNAL OF EDUCATIONAL MEASUREMENT, Issue 2 2004
Brent Bridgeman
Time limits on some computer-adaptive tests (CATs) are such that many examinees have difficulty finishing, and some examinees may be administered tests with more time-consuming items than others. Results from over 100,000 examinees suggested that about half of the examinees must guess on the final six questions of the analytical section of the Graduate Record Examination if they were to finish before time expires. At the higher-ability levels, even more guessing was required because the questions administered to higher-ability examinees were typically more time consuming. Because the scoring model is not designed to cope with extended strings of guesses, substantial errors in ability estimates can be introduced when CATs have strict time limits. Furthermore, examinees who are administered tests with a disproportionate number of time-consuming items appear to get lower scores than examinees of comparable ability who are administered tests containing items that can be answered more quickly, though the issue is very complex because of the relationship of time and difficulty, and the multidimensionality of the test. [source]


Perceived Creaminess and Viscosity of Aggregated Particles of Casein Micelles and ,-Carrageenan

JOURNAL OF FOOD SCIENCE, Issue 5 2010
Kelly L. Flett
Abstract:, Creaminess, in terms of sensory science, is a very complex and multifaceted term. It is a descriptor often reserved for fat-containing dairy emulsions, however, has also been used to describe nondairy food emulsions. In the food industry, it is a great challenge to decrease fat content while maintaining the original quality and sensory characteristics of a food product. An aggregated particle consisting of casein micelles and ,-carrageenan has the potential to enhance the perceived creaminess of a low-fat food product, due to its colloidal size. In this study, these aggregates were incorporated into nonfat dairy beverages and subjected to sensory studies. In the 1st sensory study, the aggregates, either as a powdered ingredient or a fresh ingredient, were added to thickened dairy beverages and compared to similar beverages containing skim milk powder and either no fat or 2% dairy fat. The panelists found the aggregate-containing beverages to be creamier and more viscous in comparison to the control beverages. In the 2nd sensory study, fresh and powdered aggregates, at 2 concentrations, were added to a sweetened nonfat dairy beverage and compared to a similar beverage containing 2% dairy fat. The results of this panel showed that aggregates, especially at increased concentrations, were perceived as more creamy than the fat-containing beverage. Panelists described the creaminess of the aggregates as more thick and viscous while the dairy fat was described more in terms of mouth-coating. Thus, we have developed a nonfat milk ingredient that can contribute creaminess to a food product. Practical Application:, This study shows potential applications of aggregates of casein micelles and ,-carrageenan as a fat-mimetic or creaminess-enhancing ingredient. These particles may be produced as either fresh aggregates directly formed in a dairy product or as powdered aggregates added to dairy or nondairy products. [source]


A simple model for vapor-moisture equilibrium in biomass subtrates

AICHE JOURNAL, Issue 6 2009
V. R. Vásquez
Abstract Equilibrium moisture content (EMC) plays a fundamental role on the properties of bioderived solids such as food, waste biomass, seeds, and many others. For foods, the moisture content affects flavor, texture, and the way the food is stored. In other applications, moisture affects drying conditions and energy requirements for biomass processing. Adequate modeling of EMC in biomass as a function of the water activity is very important in many engineering applications. Most models used to correlate EMC with water activity are based on traditional adsorption models which take into account the adsorption energy of water with the substrate only and do not consider other nonadsorption interactions of water within the substrate such as mixing and swelling effects. Many other models are empirical, which are commonly used for interpolation. Although a detailed description of this type of substrate is very complex, we present a simple model based on standard molecular-thermodynamic models and standard statistical mechanics formulations to correlate the EMC with water activity that attempts to consider both adsorption and nonadsorption interactions of the water with the substrate. Although the model is basic, it captures the behavior of water in this type of systems fairly well and it can be used to fit experimental data with parameters that provide better physical insight on the nature of system. We suggest how to improve the model fundamentally if better knowledge of the water interactions in the substrate are available. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source]


Living with a spouse with chronic obstructive pulmonary disease: the meaning of wives' experiences

JOURNAL OF NURSING AND HEALTHCARE OF CHRONIC ILLNE SS: AN INTERNATIONAL INTERDISCIPLINARY JOURNAL, Issue 4 2009
Anne H Boyle PhD
Aim., To describe and understand the meaning of the experience of living with a spouse who has chronic obstructive pulmonary disease. Background., Living with a spouse with a chronic illness may have a profound effect on women's lives since society expects families, and especially women, to care for the chronically ill. The family member providing care and support is usually the wife. Design., This study investigated the wife's experience of living with a husband's chronic illness. A hermeneutic phenomenological approach was used to describe and understand the experience of women living with a spouse who has chronic obstructive pulmonary disease to determine the meaning this experience has for their lives. Methods., In-depth interviews were conducted with ten women whose husbands had mild to severe obstructive lung disease. Thematic analysis was based on interpretive methods. Data were collected in 1997. Results., The findings are presented as two clusters, living with everyday illness and surviving the illness. Everyday illness includes monitoring, regulating activity, integrating illness effects, and managing technologies. Surviving the illness includes riding the roller coaster, keep on going, garnering support and finding explanations. Conclusions., The spouse's illness had a major influence on these women's lives, and the effects are very complex and interwoven with one another. Relevance to clinical practice., Health professionals can have a major role in assisting women to both live with the everyday illness and to survive its effects. Women were eager to tell their stories. Health professionals can help women deal with the experience by forming support groups and by asking the ,How can I help?' question more often and then actively listening to expressed concerns. Supporting women in their monitoring and regulating role is especially critical. [source]


Effects of tooth loss and denture wear on tongue-tip motion in elderly dentulous and edentulous people

JOURNAL OF ORAL REHABILITATION, Issue 12 2008
M. YOSHIKAWA
Summary, The purpose of this study was to clarify quantitatively the differences in tongue-tip motion among the dentulous elderly people and also among the elderly edentulous, both with and without their dentures and, to identify the influence of tooth loss and denture wear on tongue-tip motion. Fourteen young dentulous people, 12 elderly dentulous people and 13 elderly edentulous people participated in this study. Subjects were asked to swallow a 10 mL barium sulfate solution three times. The elderly edentulous people were asked to swallow the solution while wearing dentures and with dentures removed. Functional swallowing was recorded on cine-film with a digital subtraction angiography system. Lateral cinefluorography images were obtained from seated subjects. Using a cine-projector, the movements of the tongue surface were traced as dots and lines frame by frame on a single tracing sheet within a definite period of time from the beginning of the oral phase to the end of the pharyngeal phase. With counting the number of ,trajectories' of tongue-tip motion, tongue movements were classified as ,stable' and ,hyperactive' types. The results was that significantly more ,hyperactive' type subjects were found among the elderly edentulous who were not wearing dentures (12 of 13) compared with the dentulous young (1 of 14), the elderly dentulous (1 of 13) or the elderly edentulous wearing dentures (1 of 13) (P < 0.001). The tongue-tip motion for the ,hyperactive' type was very complex and the tongue-tip anchoring against the palate was always instable. [source]


Occlusion , time to reflect?

JOURNAL OF ORAL REHABILITATION, Issue 6 2005
A personal view
summary, The topic of occlusion presents a conundrum to many practitioners. To some the topic is very complex and yet to others, although important, it illustrates how adaptive the dentition is to change. This commentary presents some arguments as to how the importance of occlusion and its understanding have evolved since the Journal of Oral Rehabilitation was first published. [source]


Financial Reporting of Small Business Entities in Canada,

JOURNAL OF SMALL BUSINESS MANAGEMENT, Issue 4 2006
Michael Maingot
Financial reporting for small business entities (SBEs) has been the subject of much debate and concern by the accounting bodies (institutes) in Canada, the United States, the United Kingdom, Ireland, Australia, New Zealand, and other countries. The main issue for the standard setters is whether they should have one set of standards for all companies or two sets of standards (one for big companies and one for SBEs). The main objective of our study is to examine whether SBEs in Canada should have their own new set of Generally Accepted Accounting Principles (GAAP) or should they continue to use big GAAP used by public companies. To address this issue in the Canadian environment, we sent out a questionnaire to a sample of managers and owners of small businesses, preparers, auditors, and users of small business accounts. These stakeholders were asked to identify the purposes of SBE financial statements, their levels of satisfaction or dissatisfaction with the present accounting standards for SBEs, the burdens imposed on the preparers of the financial statements, and the weaknesses of the present standards. Furthermore, they were asked to give the expected advantages of adopting new standards, after having ranked four models of financial reporting of SBEs. The results are quite interesting. Stakeholders indicated that financial statements of SBEs are prepared mainly for taxation purposes and borrowing. They are not satisfied with the present standards because they are costly to comply with and very complex. The burden of producing SBE financial statements can be reduced by simplifying the present standards. The new standards would mean a shorter and simpler form of financial statements. It is hoped that the results of this study will provide the standard setters in Canada and other countries with an indication of the future direction for SBE reporting and accounting. [source]


A primary care provider's guide to preventive and acute care management of adults and children with sickle cell disease

JOURNAL OF THE AMERICAN ACADEMY OF NURSE PRACTITIONERS, Issue 5 2009
Ardie Pack-Mabien RNC, CRNP (Clinical Nurse Practitioner & Nurse Manager)
Abstract Purpose: To familiarize primary care providers (PCPs) with the pathophysiological processes, diagnostic evaluation, and medical management of sickle hemoglobinopathies and their complications. Current standards of care, clinical research advances, and new treatment options will also be addressed to assist PCPs in the management of sickle cell disease (SCD). Data sources: A selective search and review of the current literature on SCD and the authors' experience. Conclusions: Management of individuals with SCD is very complex, requiring a multidisciplinary approach that includes the patient or parent, PCP, specialist, nurse, and social worker. More patients living with SCD are relying on PCPs in nonspecialty practices for comprehensive disease management. Implications for practice: Newborn screening detects new cases of SCD annually. The median life expectancy has more than doubled for individuals with sickle cell anemia. Healthcare providers are now in an era of increased routine screening, assessment, and management of chronic complications from this illness not previously seen in the care of adults with SCD. [source]


EAACI/GA2LEN/EDF/WAO guideline: definition, classification and diagnosis of urticaria

ALLERGY, Issue 10 2009
T. Zuberbier
This guideline, together with its sister guideline on the management of urticaria [Zuberbier T, Asero R, Bindslev-Jensen C, Canonica GW, Church MK, Giménez-Arnau AM et al. EAACI/GA²LEN/EDF/WAO Guideline: Management of urticaria. Allergy, 2009; 64:1427,1443] is the result of a consensus reached during a panel discussion at the 3rd International Consensus Meeting on Urticaria, Urticaria 2008, a joint initiative of the Dermatology Section of the European Academy of Allergology and Clinical Immunology (EAACI), the EU-funded network of excellence, the Global Allergy and Asthma European Network (GA²LEN), the European Dermatology Forum (EDF) and the World Allergy Organization (WAO). Urticaria is a frequent disease. The life-time prevalence for any subtype of urticaria is approximately 20%. Chronic spontaneous urticaria and other chronic forms of urticaria do not only cause a decrease in quality of life, but also affect performance at work and school and, as such, are members of the group of severe allergic diseases. This guideline covers the definition and classification of urticaria, taking into account the recent progress in identifying its causes, eliciting factors, and pathomechanisms. In addition, it outlines evidence-based diagnostic approaches for different subtypes of urticaria. The correct management of urticaria, which is of paramount importance for patients, is very complex and is consequently covered in a separate guideline developed during the same consensus meeting. This guideline was acknowledged and accepted by the European Union of Medical Specialists (UEMS). [source]


Age-dependent changes in the nervous and endocrine control of the thymus

MICROSCOPY RESEARCH AND TECHNIQUE, Issue 2 2004
Jonas Hannestad
Abstract The immune system, especially the thymus, undergoes age-related modifications leading to structural and functional changes in the lymphoid organs and immunocompetent cells. Nevertheless, the consequences of thymic involution in the peripheral pool of T-cells are still a matter of controversy. The control of the thymic function is very complex and involves intrathymic signals, the autonomic nervous system, and the endocrine system. Both thymocytes and thymic stromal cells express receptors for a wide range of hormones, as well as for neurotransmitters and neuropeptides, thus affecting thymocytes maturation. This review summarizes the age-dependent variations in the extrathymic components of the thymic microenvironment, i.e., vegetative nerves and hormones, and the possible effects of those changes in the immune function. Microsc. Res. Tech. 63:94,101, 2004. © 2004 Wiley-Liss, Inc. [source]


The effect of drought and heat stress on reproductive processes in cereals

PLANT CELL & ENVIRONMENT, Issue 1 2008
BEÁTA BARNABÁS
ABSTRACT As the result of intensive research and breeding efforts over the last 20 years, the yield potential and yield quality of cereals have been greatly improved. Nowadays, yield safety has gained more importance because of the forecasted climatic changes. Drought and high temperature are especially considered as key stress factors with high potential impact on crop yield. Yield safety can only be improved if future breeding attempts will be based on the valuable new knowledge acquired on the processes determining plant development and its responses to stress. Plant stress responses are very complex. Interactions between plant structure, function and the environment need to be investigated at various phases of plant development at the organismal, cellular as well as molecular levels in order to obtain a full picture. The results achieved so far in this field indicate that various plant organs, in a definite hierarchy and in interaction with each other, are involved in determining crop yield under stress. Here we attempt to summarize the currently available information on cereal reproduction under drought and heat stress and to give an outlook towards potential strategies to improve yield safety in cereals. [source]


A composite model for municipal solid waste

PROCEEDINGS IN APPLIED MATHEMATICS & MECHANICS, Issue 1 2005
Volker Krase
The mechanical behaviour of municipal solid waste is very complex due to the internal structure and differs considerably from ordinary materials. The fundamental idea of the presented mechanical constitutive model is the split of the material into two solid phases, justified by experimental observations, where fibrous particles signi.cantly influence the composite behaviour. Constitutive laws are independently introduced for each phase. A .nite deformation theory is applied, whereas the concept of elastoplasticity allows reproducing the highly non-linear stress-strain relations. A creep law describes time-depending deformation under compression loads. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


Large-scale phosphoproteome analysis of human liver tissue by enrichment and fractionation of phosphopeptides with strong anion exchange chromatography

PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 7 2008
Guanghui Han
Abstract The mixture of phosphopeptides enriched from proteome samples are very complex. To reduce the complexity it is necessary to fractionate the phosphopeptides. However, conventional enrichment methods typically only enrich phosphopeptides but not fractionate phosphopeptides. In this study, the application of strong anion exchange (SAX) chromatography for enrichment and fractionation of phosphopeptides was presented. It was found that phosphopeptides were highly enriched by SAX and majority of unmodified peptides did not bind onto SAX. Compared with Fe3+ immobilized metal affinity chromatography (Fe3+ -IMAC), almost double phosphopeptides were identified from the same sample when only one fraction was generated by SAX. SAX and Fe3+ -IMAC showed the complementarity in enrichment and identification of phosphopeptides. It was also demonstrated that SAX have the ability to fractionate phosphopeptides under gradient elution based on their different interaction with SAX adsorbent. SAX was further applied to enrich and fractionate phosphopeptides in tryptic digest of proteins extracted from human liver tissue adjacent to tumorous region for phosphoproteome profiling. This resulted in the highly confident identification of 274 phosphorylation sites from 305 unique phosphopeptides corresponding to 168 proteins at false discovery rate (FDR) of 0.96%. [source]


PROSPECT lost: when a pilot project does not look to learn

PUBLIC ADMINISTRATION & DEVELOPMENT, Issue 2 2008
Michael Mattingly
Abstract If a development project is destined to reach only a selection of its intended beneficiaries or to give them only momentary or uncertain benefits, there is a strong rationale for making it instead a project of trials from which lessons can be taken for obtaining the impact that it may not otherwise have. Because the fundamental problems and opportunities of development are very complex by their nature, interventions that seek to test practice knowledge and to learn above all else may have the greatest potential for benefit in the long term. A project that wishes to create experience from which others can learn will engage in research, so it must be conceived, led and conducted as such. This means it must be designed with knowledge of research. It must be led with an appreciation and understanding of research method. Specific research activities must be conducted that produce knowledge and promote its up-take, so that learning is a principle project outcome. The large urban anti-poverty project, PROSPECT, conducted in Lusaka, Zambia, illustrates this argument. Copyright © 2008 John Wiley & Sons, Ltd. [source]


Mitochondrial DNA diversity and origins of South and Central American goats

ANIMAL GENETICS, Issue 3 2009
M. Amills
Summary We have analysed the genetic diversity of South and Central American (SCA) goats by partially sequencing the mitochondrial control region of 93 individuals with a wide geographical distribution. Nucleotide and haplotype diversities reached values of 0.020 ± 0.00081 and 0.963 ± 0.0012 respectively. We have also observed a rather weak phylogeographic structure, with almost 69% of genetic variation included in the within-breed variance component. The topology of a median-joining network analysis including 286 European, Iberian, Atlantic and SCA mitochondrial sequences was very complex, with most of the haplotypes forming part of independent small clusters. SCA sequences showed a scattered distribution throughout the network, and clustering with Spanish and Portuguese sequences occurred only occasionally, not allowing the distinguishing of a clear Iberian signature. Conversely, we found a prominent cluster including Canarian, Chilean, Argentinian and Bolivian mitochondrial haplotypes. This result was independently confirmed by constructing a Bayesian phylogenetic tree (posterior probability of 0.97). Sharing of mitochondrial haplotypes by SCA and Canarian goats suggests that goat populations from the Atlantic archipelagos, where Spanish and Portuguese ships en route to the New World used to stow food and supplies, participated in the foundation of SCA caprine breeds. [source]


Comparison of multivariate methods for robust parameter design in sheet metal spinning

APPLIED STOCHASTIC MODELS IN BUSINESS AND INDUSTRY, Issue 3 2004
Corinna Auer
Abstract Sheet metal spinning is a very complex forming process with a large number of quality characteristics. Within the scope of a joint project of the Department of Statistics and the Chair of Forming Technology the impact of process parameters (design factors) on important quality characteristics has been investigated both theoretically and experimentally. In the past, every response has been treated individually and uncontrollable disturbances (noise factors) have been neglected. Now this approach has been extended to robust multiresponse parameter design. For this, a review of common multivariate approaches for robust parameter design has been carried out, which also leads to the proposal of some new variants. In addition to the theoretical comparison, the methods were applied to data gained in the sheet metal spinning process. The obtained results were evaluated in terms of applicability, limitations and quality accuracy. Practical experiments confirmed the high degree of efficiency that the finally proposed method based on desirabilities promises. Copyright © 2004 John Wiley & Sons, Ltd. [source]


Neurohormonal regulation of feed intake and response to nutrients in fish: aspects of feeding rhythm and stress

AQUACULTURE RESEARCH, Issue 5 2010
Ewa Kulczykowska
Abstract The regulation of feed intake is very complex and involves interaction among the circadian and homeostatic control systems within the central nervous system, the gastrointestinal tract and the environment. The hypothalamus, which receives, integrates and transmits relevant internal and external signals, is recognized as the primary centre of regulation of feed intake. The neuroendocrine factors that originate from the hypothalamus either stimulate or inhibit feed intake so that nutritional demands of the organism can be fulfilled and energy balance can be achieved. Appetite regulation is a physiological mechanism in which a variety of neurohormones interact and fish show different feeding behaviour (e.g. diurnal, nocturnal). This complicated system is very sensitive to any disturbance. Fish in farms and fish in a natural environment are equipped with the same combination of neurohormones to regulate feed intake, but they meet different challenges, particularly with regard to the type of feed and feeding schedule. In this review, the neurohormonal regulation of feed intake is analysed in fish in terms of entrainment of their circadian feeding rhythms and while exposed to different stressors in captivity. [source]


A novel approach for the kinetic and mechanistic modeling of acid-catalyzed degradation of polymers

ASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 2 2009
Y.-H. Lin
Abstract A new approach is presented that combines kinetic and mechanistic considerations which take into account chemical reactions and catalyst deactivation in the modeling of the catalytic degradation of polymers. Though acid-catalyzed hydrocarbon cracking reactions involve a large number of compounds, reactions and catalyst deactivation and are very complex, the model gives a good representation of experimental results from the degradation of polypropylene over fluidized acidic catalysts. This model provides the benefits of product selectivity for the chemical composition, such as alkanes, alkenes, aromatics and coke, in relation to the effect of structurally different polymer feeds, and the performance of the catalyst used. It is an improvement of the currently available empirical ,lumping' techniques which usually are severely restricted in terms of product definitions. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source]


X-chromosome upregulation and inactivation: two sides of the dosage compensation mechanism in mammals

BIOESSAYS, Issue 1 2009
Elena V. Dementyeva
Abstract Mammals have a very complex, tightly controlled, and developmentally regulated process of dosage compensation. One form of the process equalizes expression of the X-linked genes, present as a single copy in males (XY) and as two copies in females (XX), by inactivation of one of the two X-chromosomes in females. The second form of the process leads to balanced expression between the X-linked and autosomal genes by transcriptional upregulation of the active X in males and females. However, not all X-linked genes are absolutely balanced. This review is focused on the recent advances in studying the dosage compensation phenomenon in mammals. [source]


Metagenomic studies reveal the critical and wide-ranging ecological importance of uncultivated archaea: the role of ammonia oxidizers

BIOESSAYS, Issue 1 2007
Ricardo Cavicchioli
Microbial genome sequencing has entered a new phase, where DNA sequence information is gathered from entire microbial communities (metagenomics or environmental genomics) rather than from individual microorganisms. By providing access to the genetic material of vast numbers of organisms, most of which are organisms that have never been isolated or cultivated, a new level of insight is being gained into the diversity and extent of the microbial processes that are presently occuring in environmental communities. By extending metagenomic-based approaches to the study of very complex and methodologically recalcitrant soil environments, a recent study has found that ammonia-oxidizing archaea are more abundant in many soils than bacteria.1 These findings not only highlight the undoubtedly critical yet unknown roles that archaea play in global nutrient cycles but illustrate the importance of genomic studies for informing us about the functional capacity of life on Earth. BioEssays 29: 11,14, 2007. © 2006 Wiley Periodicals, Inc. [source]


Origin and Distribution of Hydrogen Sulfide in Oil-Bearing Basins, China

ACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 6 2009
ZHU Guangyou
Abstract: The concentration of hydrogen sulfide gas (H2S) varies greatly in the oil-bearing basins of China, from zero to 90%. At present, oil and gas reservoirs with high H2S concentration have been discovered in three basins, viz. the Bohai Bay Basin, Sichuan Basin and the Tarim Basin, whereas natural gas with low H2S concentration has been found in the Ordos Basin, the Songliao Basin and the Junggar Basin. Studies suggest that in China H2S origin types are very complex. In the carbonate reservoir of the Sichuan Basin, the Ordos Basin and the Tarim Basin, as well as the carbonate-dominated reservoir in the Luojia area of the Jiyang depression in the Bohai Bay Basin, Wumaying areas of the Huanghua depression, and Zhaolanzhuang areas of the Jizhong depression, the H2S is of Thermochemical Sulfate Reduction (TSR) origin. The H2S is of Bacterial Sulphate Reduction (BSR) origin deduced from the waterflooding operation in the Changheng Oilfield (placanticline oil fields) in the Songliao Basin. H2S originates from thermal decomposition of sulfur-bearing crude oil in the heavy oil area in the Junggar Basin and in the Liaohe heavy oil steam pilot area in the western depression of the Bohai Bay Basin. The origin types are most complex, including TSR and thermal decomposition of sulfcompounds among other combinations of causes. Various methods have been tried to identify the origin mechanism and to predict the distribution of H2S. The origin identification methods for H2S mainly comprise sulfur and carbon isotopes, reservoir petrology, particular biomarkers, and petroleum geology integrated technologies; using a combination of these applications can allow the accurate identification of the origins of H2S. The prediction technologies for primary and secondary origin of H2S have been set up separately. [source]


Status of Observational Models Used in Design and Control of Products and Processes

COMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY, Issue 1 2008
Shyam S. Sablani
This article is part of a collection entitled "Models for Safety, Quality, and Competitiveness of the Food Processing Sector," published in Comprehensive Reviews in Food Science and Food Safety. It has been peer-reviewed and was written as a follow-up of a pre-IFT workshop, partially funded by the USDA NRI grant 2005-35503-16208. ABSTRACT:, Modeling techniques can play a vital role in developing and characterizing food products and processes. Physical, chemical, and biological changes that take place during food and bioproduct processing are very complex and experimental investigation may not always be possible due to time, cost, effort, and skills needed. In some cases even experiments are not feasible to conduct. Often it is difficult to visualize the complex behavior of a data set. In addition, modeling is a must for process design, optimization, and control. With the rapid development of computer technology over the past few years, more and more food scientists have begun to use computer-aided modeling techniques. Observation-based modeling methods can be very useful where time and resources do not allow complete physics-based understanding of the process. This review discusses the state of selected observation-based modeling techniques in the context of industrial food processing. [source]