Rate Of Introduction Research Articles

Applying engineering and fleet detail to represent passenger vehicle transport in a computable general equilibrium model

A well-known challenge in computable general equilibrium (CGE) models is to maintain correspondence between the forecasted economic and physical quantities over time. Maintaining such a correspondence is necessary to understand how economic forecasts reflect, and are constrained by, relationships within the underlying physical system. This work develops a method for projecting global demand for passenger vehicle transport, retaining supplemental physical accounting for vehicle stock, fuel use, and greenhouse gas (GHG) emissions. This method is implemented in the MIT Emissions Prediction and Policy Analysis Version 5 (EPPA5) model and includes several advances over previous approaches. First, the relationship between per-capita income and demand for passenger vehicle transport services (in vehicle-miles traveled, or VMT) is based on econometric estimates and modeled using quasi-homothetic preferences. Second, the passenger vehicle transport sector is structured to capture opportunities to reduce fleet-level gasoline use through the application of vehicle efficiency or alternative fuel vehicle technologies, introduction of alternative fuels, or reduction in demand for VMT. Third, alternative fuel vehicles (AFVs) are represented in the EPPA model. Fixed costs as well as learning effects that could influence the rate of AFV introduction are captured explicitly. This model development lays the foundation for assessing policies that differentiate based on vehicle age and efficiency, alter the relative prices of fuels, or focus on promoting specific advanced vehicle or fuel technologies.

An ontology learning system for customer needs representation in product development

The intense competition and high failure rate of product introduction necessitate a deeper understanding of customer needs for product design. The conventional process of interpreting customer statements relies on imprecise information, making it highly unlikely, if not impossible, to acquire accurate need statements for the front-end process of product development. To deal with this problem, an ontology-learning customer needs representation (OCNR) system is proposed in this paper. The system uses natural language processing tools to preprocess customer statements. The customer needs ontology is then established based on the key concepts and their relations that are extracted from the customer statements. A set of need statements are then generated using the established customer needs ontology. A word property-based method is proposed to extract more nontaxonomic relations. A case study was conducted to illustrate the proposed approach. Results of this study suggest that the customer needs ontology derived from the proposed OCNR system contains more semantics than those obtained from the existing ontology learning systems, and, therefore, might be able to generate more accurate need statements.

Alien mammals in Europe: updated numbers and trends, and assessment of the effects on biodiversity

This study provides an updated picture of mammal invasions in Europe, based on detailed analysis of information on introductions occurring from the Neolithic to recent times. The assessment considered all information on species introductions, known extinctions and successful eradication campaigns, to reconstruct a trend of alien mammals' establishment in the region. Through a comparative analysis of the data on introduction, with the information on the impact of alien mammals on native and threatened species of Europe, the present study also provides an objective assessment of the overall impact of mammal introductions on European biodiversity, including information on impact mechanisms. The results of this assessment confirm the constant increase of mammal invasions in Europe, with no indication of a reduction of the rate of introduction. The study also confirms the severe impact of alien mammals, which directly threaten a significant number of native species, including many highly threatened species. The results could help to prioritize species for response, as required by international conventions and obligations.

Evolution of resistance to quorum quenching in digital organisms.

Quorum sensing (QS) is a collective behavior whereby actions of individuals depend on the density of the surrounding population. Bacteria use QS to trigger secretion of digestive enzymes, formation and destruction of biofilms, and, in the case of pathogenic organisms, expression of virulence factors that cause disease. Investigations of mechanisms that prevent or disrupt QS, referred to as quorum quenching, are of interest because they provide a new alternative to antibiotics for treating bacterial infections. Traditional antibiotics either kill bacteria or inhibit their growth, producing selective pressures that promote resistant strains. In contrast, quorum quenching and other so-called anti-infective strategies focus on altering behavior. In this article we evolve QS in populations of digital organisms, a type of self-replicating computer program, and investigate the effects of quorum quenching on these populations. Specifically, we injected the populations with mutant organisms that were impaired in selected ways to disrupt the QS process. The experimental results indicate that the rate at which these mutants are introduced into a population influences both the evolvability of QS and the persistence of an existing QS behavior. Surprisingly, we also observed resistance to quorum quenching. Effectively, populations evolved resistance by reaching quorum at lower cell densities than did the parent strain. Moreover, the level of resistance was highest when the rate of mutant introduction increased over time. These results show that digital organisms can serve as a model to study the evolution and disruption of QS, potentially informing wet-lab studies aimed at identifying targets for anti-infective development.

Will extreme climatic events facilitate biological invasions?

Extreme climatic events (ECEs) – such as unusual heat waves, hurricanes, floods, and droughts – can dramatically affect ecological and evolutionary processes, and these events are projected to become more frequent and more intense with ongoing climate change. However, the implications of ECEs for biological invasions remain poorly understood. Using concepts and empirical evidence from invasion ecology, we identify mechanisms by which ECEs may influence the invasion process, from initial introduction through establishment and spread. We summarize how ECEs can enhance invasions by promoting the transport of propagules into new regions, by decreasing the resistance of native communities to establishment, and also sometimes by putting existing non‐native species at a competitive disadvantage. Finally, we outline priority research areas and management approaches for anticipating future risks of unwanted invasions following ECEs. Given predicted increases in both ECE occurrence and rates of species introductions around the globe during the coming decades, there is an urgent need to understand how these two processes interact to affect ecosystem composition and functioning.

Age of introduction of ten sentinel complementary foods as reported for 6 to 12 month old, low‐income infants in metropolitan, Quetzaltenango (Western Highlands), compared to Guatemala City and Santo Domingo Xenacoj (Central Highlands)

BackgroundThe WHO recommends exclusive breastfeeding (EBF) during the first 6 mo of life. Evidence complied in earlier studies of CeSSIAM documented that mixed feeding often occurs earlier.ObjectiveTo compare the pattern of age of introduction of commonly consumed foods in the western highlands with what has been reported from the central highlands of Guatemala.MethodsAge of introduction of 10 sentinel foods was queried by means of structured face‐to‐face interviews in 6 to 11 mo old infants living in 2 urban areas (Quetzaltenango, n=128 and Guatemala City, n=64) and 1 rural area (Santo Domingo Xenacoj, n=64).ResultsItems most frequently reported as introduced before 6 mo in Quetzaltenango were vegetables (28%), followed by fruits (27%), Incaparina® (23%), potatoes (20%), and sweet rolls (17%). These rates of premature introduction are higher than reported in a poor neighborhood in Guatemala City with a respective: fruits (18%); vegetables (17%); potatoes (14%); Incaparina® (13%); and rice (11%). The hierarchy in a Mayan village was: potatoes (15%); vegetables (13%); Incaparina® (13%); rice (12%); and oatmeal (11%).ConclusionDifferent patterns of early introduction of food and beverage items contribute to the precocious occurrence of mixed feeding in the first semester of infancy in distinct regions of Guatemala.Funded by the Nestlé Foundation, Switzerland

Rate of introduction of a low pathogenic avian influenza virus infection in different poultry production sectors in the Netherlands

Please cite this paper as: Gonzales et al. (2012) Rate of introduction of a low pathogenic avian influenza virus infection in different poultry production sectors in the Netherlands. Influenza and Other Respiratory Viruses DOI: 10.1111/j.1750‐2659.2012.00348.x. Background Targeted risk‐based surveillance of poultry types (PT) with different risks of introduction of low pathogenic avian influenza virus (LPAIv) infection may improve the sensitivity of surveillance. Objective To quantify the rate of introduction of LPAIv infections in different PT. Methods Data from the Dutch LPAIv surveillance programme (2007–2010) were analysed using a generalised linear mixed and spatial model. Results Outdoor‐layer, turkey, duck‐breeder and meat‐duck, farms had a 11, 8, 24 and 13 times higher rate of introduction of LPAIv than indoor‐layer farms, respectively. Conclusion Differences in the rate of introduction of LPAIv could be used to (re)design a targeted risk‐based surveillance programme.

A multi-agent system using iterative bidding mechanism to enhance manufacturing agility

The global market has become increasingly dynamic, unpredictable and customer-driven. This has led to rising rates of new product introduction and turbulent demand patterns across product mixes. As a result, manufacturing enterprises were facing mounting challenges to be agile and responsive to cope with market changes, so as to achieve the competitiveness of producing and delivering products to the market timely and cost-effectively. This paper introduces a currency-based iterative agent bidding mechanism to effectively and cost-efficiently integrate the activities associated with production planning and control, so as to achieve an optimised process plan and schedule. The aim is to enhance the agility of manufacturing systems to accommodate dynamic changes in the market and production. The iterative bidding mechanism is executed based on currency-like metrics; each operation to be performed is assigned with a virtual currency value and agents bid for the operation if they make a virtual profit based on this value. These currency values are optimised iteratively and so does the bidding process based on new sets of values. This is aimed at obtaining better and better production plans, leading to near-optimality. A genetic algorithm is proposed to optimise the currency values at each iteration. In this paper, the implementation of the mechanism and the test case simulation results are also discussed.

A model-based tool to predict the propagation of infectious disease via airports

SummaryEpidemics of novel or re-emerging infectious diseases have quickly spread globally via air travel, as highlighted by pandemic H1N1 influenza in 2009 (pH1N1). Federal, state, and local public health responders must be able to plan for and respond to these events at aviation points of entry.The emergence of a novel influenza virus and its spread to the United States were simulated for February 2009 from 55 international metropolitan areas using three basic reproduction numbers (R0): 1.53, 1.70, and 1.90. Empirical data from the pH1N1 virus were used to validate our SEIR model.Time to entry to the U.S. during the early stages of a prototypical novel communicable disease was predicted based on the aviation network patterns and the epidemiology of the disease. For example, approximately 96% of origins (R0 of 1.53) propagated a disease into the U.S. in under 75 days, 90% of these origins propagated a disease in under 50 days. An R0 of 1.53 reproduced the pH1NI observations.The ability to anticipate the rate and location of disease introduction into the U.S. provides greater opportunity to plan responses based on the scenario as it is unfolding. This simulation tool can aid public health officials to assess risk and leverage resources efficiently.

Aphids (Hemiptera: Aphididae and Adelgidae) of Hawai‘i: Annotated List and Key to Species of an Adventive Fauna

We provide a comprehensive compilation of 105 species of Aphidoidea adventive to the Hawaiian Islands based on literature records and a taxonomic analysis of available specimens. Seventeen species are recognized as new to the Islands. For each species information on synonyms, origins, distribution, and hosts is given. The average rate of introduction has been about 0.82 species per year. Approximately 35% of the species originate in East Asia, 35% from Europe and West Asia, and 21% from North America.

Determinants of inappropriate complementary feeding practices in young children in Nepal: secondary data analysis of Demographic and Health Survey 2006

Inappropriate complementary feeding increases the risk of undernutrition, illness and mortality in infants and children. This study uses a subsample of 1428 children of 6-23 months from Nepal Demographic and Health Survey (NDHS), 2006. The 2006 NDHS was a multistage cluster sample survey. The complementary feeding indicators were estimated according to the 2008 World Health Organization recommendations. The rate of introduction of solid, semi-solid or soft foods to infants aged 6-8 months was 70%. Minimum meal frequency and minimum dietary diversity rates were 82% and 34%, respectively, and minimum acceptable diet for breastfed infants was 32%. Multivariate analysis indicated that working mothers and mothers with primary or no education were significantly less likely to give complementary foods, to meet dietary diversity, minimum meal frequency and minimum acceptable diet. Children living in poor households were significantly less likely to meet minimum dietary diversity and minimum acceptable diet. Mothers who had adequate exposure to media, i.e. who watch television and who listen to radio almost every day, were significantly more likely to meet minimum dietary diversity and meal frequency. Infants aged 6-11 months were significantly less likely to meet minimum acceptable diet [adjusted odds ratio (OR)=3.13, confidence interval (CI)=2.16-4.53] and to meet minimum meal frequency (adjusted OR=4.46, CI=2.67-7.46). In conclusion, complementary feeding rates in Nepal are inadequate except for minimum meal frequency. Planning and promotion activities to improve appropriate complementary feeding practices should focus on illiterate mothers, those living in poor households, and those not exposed to media.

Phylogenetic beta diversity of native and alien species in European urban floras

ABSTRACTAim Human activities have weakened biogeographical barriers to dispersal, increasing the rate of introduction of alien plants. However, their impact on beta diversity and floristic homogenization is poorly understood. Our goal is to compare the phylogenetic beta diversity of native species with that of two groups of alien species, archaeophytes and neophytes (introduced before and after ad 1500, respectively), across European urban floras to explore how biological invasions affect phylogenetic turnover at a continental scale.Location Twenty European cities located in six countries between 49 and 53° N latitude in continental Europe and the British Isles.Methods To compare the phylogenetic beta diversity of native and alien species we use the average phylogenetic dissimilarity of individual floras from their group centroid in multivariate space. Differences in phylogenetic beta diversity among different species groups are then assessed using a randomization test for homogeneity of multivariate dispersions.Results Across European urban floras, and when contrasted with natives, archaeophytes are usually associated with lower levels of phylogenetic beta diversity while neophytes tend to increase phylogenetic differentiation.Main conclusions While archaeophytes tend to promote limited homogenization in phylogenetic beta diversity, because of their diverse geographical origin together with short residence times in the invaded regions, neophytes are not promoting biotic homogenization of urban floras across Europe. Therefore, in spite of the increasing rate of alien invasion, an intense phylogenetic homogenization of urban cities is not to be expected soon.

In-roads to the spread of antibiotic resistance: regional patterns of microbial transmission in northern coastal Ecuador.

The evolution of antibiotic resistance (AR) increases treatment cost and probability of failure, threatening human health worldwide. The relative importance of individual antibiotic use, environmental transmission and rates of introduction of resistant bacteria in explaining community AR patterns is poorly understood. Evaluating their relative importance requires studying a region where they vary. The construction of a new road in a previously roadless area of northern coastal Ecuador provides a valuable natural experiment to study how changes in the social and natural environment affect the epidemiology of resistant Escherichia coli. We conducted seven bi-annual 15 day surveys of AR between 2003 and 2008 in 21 villages. Resistance to both ampicillin and sulphamethoxazole was the most frequently observed profile, based on antibiogram tests of seven antibiotics from 2210 samples. The prevalence of enteric bacteria with this resistance pair in the less remote communities was 80 per cent higher than in more remote communities (OR = 1.8 [1.3, 2.3]). This pattern could not be explained with data on individual antibiotic use. We used a transmission model to help explain this observed discrepancy. The model analysis suggests that both transmission and the rate of introduction of resistant bacteria into communities may contribute to the observed regional scale AR patterns, and that village-level antibiotic use rate determines which of these two factors predominate. While usually conceived as a main effect on individual risk, antibiotic use rate is revealed in this analysis as an effect modifier with regard to community-level risk of resistance.

AlSi7Mg/SiC and Heterophase SiC<sub>P</sub>+C<sub>G</sub> Composite for Use in Cylinder-Piston System of Air Compressor

The article presents the results of the first phase of research on the development of manufacturing composites by pilot-scale technology. Producing of composite suspension in sufficient quantity to obtain approximately 50 casting pistons in one production cycle was the aim of this study. This allowed to assess the stability of the composite suspension manufacturing process and above all stability the casting process. Composite suspension (AlSi7Mg/SiCp and heterophase SiCp+Cg ) were prepared in one technological cycle including refining and modification of the alloy matrix, the introduction of ceramic particles and the homogenization of the suspension under reduced pressure. Objective of this study was to determine the basic parameters of the suspension of the manufacturing process, such as metal refining period, the rate of particles introduction and time of homogenization. In addition, as a evaluation criterion of quality the manufactured composite material accepted the possibility of pre-cast piston machining.

Vaccination strategies to conserve the endangered African wild dog ( Lycaon pictus)

Pathogens such as rabies virus and canine distemper virus present a significant risk to the long-term survival of some endangered African wild dog ( Lycaon pictus) populations. Vaccination of wild dogs is one approach that might reduce population extinction risks; however clear guidelines for how best to do this are lacking. Hence, we developed a mathematical model of wild dog population dynamics that integrates a pathogen transmission model and a vaccination process. Simulations indicated that the most effective vaccination strategy includes all age classes (when pups are 2-months old), prioritizes the breeding pair, and vaccinates at least 4 animals per pack included in the vaccination effort. In addition, populations for which an Allee effect, high rates of pathogen introduction, or low rates of recovery and immunity were simulated, required greater vaccination coverage (dogs/pack), to protect an equivalent number of packs compared to populations for which no Allee effect, low rates of pathogen introduction, or high rates of recovery and immunity were simulated. For populations in which some packs (high-risk) have a greater risk of pathogen exposure than others (low-risk), vaccinating both high- and low-risk packs, or only low-risk packs, is more effective than vaccinating only high-risk packs when pathogen introduction rates are high. Finally, model results suggest that vaccination of wild dog populations against pathogens, such as canine distemper virus, that do not cause 100% mortality and against which some wild dogs develop acquired immunity, may be unnecessary.

Marine alien species in Greek Seas: Additions and amendments by 2010

An update of the inventory of alien marine species from the coastal and offshore waters of Greece is presented. Records were compiled based on the existing scientific and grey literature, including the HCMR database of Greek alien species (ELNAIS), technical reports, scientific congresses, academic dissertations, websites, and unpublished/personal observations. 47 species were added to the inventory, including 34 invertebrates, one vertebrate (fish), three plants, eight protozoa, and one cyanobacterium. With the new records, the inventory of alien marine species of Greece now includes a total of 237 species (33 macrophytes, 131 invertebrates, 42 vertebrates, two bacteria and 29 protozoans). Among these, the presence of the gastropodHypselodoris infucata, the bivalvesDendrostrea frons and Septifer forskaliand the chondrichthyan Rhizoprionodon acutus is reported here for the first time. Based on molecular analysis, the occurrence of Bulla arabica in Greek waters is confirmed, and the suggestion that previous records of Bulla ampulla in the Mediterranean should be considered as misidentification of B. arabica is further supported. The acclimitization status of earlier records was revised in the light of new data, and thus the fishEnchelycore anatina, Seriola fasciata andTylerius spinosissimus, the red algaeHypnea cornuta and Sarconema scinaioides, the scyphomedusaCassiopea andromeda, the cephalopodSepioteuthis lessoniana, the nudibranchChromodoris annulata and the bivalvesGastrochaena cymbium andPseudochama corbieri were upgraded from casual records to established populations. The increased rate of introductions of warm water species confirms previous findings, which link the rate of introduction in the eastern Mediterranean to climate change.

The influence of hydrogenation on the electrical properties of the Cd x Hg1 − x Te epitaxial structures

The phenomenon of hydrogenation of the CdxHg1 − xTe films is studied. Hydrogenation was performed via either boiling the CdxHg1 − xTe films in deionized water or using the electrochemical treatment. It is established that, during contacts with aqueous media, the acceptor centers are introduced into the films; their concentration can exceed 1017 cm−3. It is shown that two types of hydrogen-based acceptors are introduced, namely, fast and slow acceptors, and their diffusivities are evaluated. It is found that hydrogen partially exists after treatment in an electrically inactive form and can be activated with further storage or during heating. After activation, the hole concentration can become as high as 1018 cm−3. The influence of pH of the medium on the rate of introduction of hydrogen into the material is discussed.

Economic Growth and Business Cycles: The Labor Supply Decision with Two Types of Technological Progress

An informal model is described that leads to multiple macroeconomic equilibria as a consequence of random variation in the relative amounts of technological change for new and existing goods. The novel observation is that the rate of introduction and market penetration of new goods (sometimes called product innovation) vis-à-vis technological advance for existing goods (sometimes called process innovation) importantly affects the labor supply decision. A relatively rapid influx of new goods will generally increase labor supply, while relatively more technological advance for existing goods will reduce labor supply to the market. These impacts are seen to provide insights into Rostow’s stages of growth. Short run variations in the relative importance of the two types of technological change are seen to imply unpredictable business cycle behavior of the type we observe. The welfare implications of national income accounting that fails to consider changes in leisure are discussed.

Innovation as an Emerging System Property: An Agent Based Simulation Model

The paper elaborates the notion of innovation as an emerging property of complex system dynamics and presents an agent-based simulation model (ABM) of an economy where systemic knowledge interactions among heterogeneous agents are crucial for the recombinant generation of new technological knowledge and the introduction of innovations. In this approach the organization of the system plays a crucial role in assessing the chances of individual firms to actually introduce innovations because it qualifies the access to external knowledge, an indispensable input, together with internal learning and research activities, into the recombinant generation of new knowledge. The introduction of innovations is analyzed as the result of systemic knowledge interactions among myopic agents that are credited with an extended procedural rationality that includes forms of creative reaction. The creative reaction of agents may lead to the introduction of productivity enhancing innovations. This takes place only when the structural, organizational and institutional characteristics of the system are such that agents, reacting to out-of-equilibrium conditions, can actually take advantage of external knowledge available within the innovation system into which they are embedded to generate new technological knowledge. The ABM enables one to explore effects of alternative organizational features of the systems, namely different configurations of the intellectual property right regimes and different architectural configurations of the regional structure into which knowledge interactions take place, on the rates of introduction of technological innovations. The results of the ABM suggest that the dissemination of knowledge favors the emergence of creative reactions and hence faster rates of introduction of technological innovations.

MODELOS DINÂMICOS DE ASSEMBLÉIA

The structure of an ecological community is shaped by several temporally varying mechanisms. Such mechanisms depend in a large extent on species interactions, which are themselves manifestations of the community's own structure. Dynamics and structure are then mutually determined. The assembly models are mathematical or computational models which simulate the dynamics of ecological communities resulting from a historical balance among colonizations and local extinctions, by means of sequential species introductions and their interactions with resident species. They allow analyzing that double relationship between structure and dynamics, recognizing its temporal dependence. It is assumed two spatiotemporal scales: (i) a local scale, where species co-occur and have their dynamics explicitly simulated and (ii) a regional scale without dynamics, representing the external environment which the potential colonizers come from. The mathematical and computational models used to simulate the local dynamics are quite variable, being distinguished according to the complexity mode of population representation, including or not intra or interspecific differences. They determine the community state, in terms of abundances, interactions, and extinctions between two successive colonization attempts. The schedules of species introductions also follow diverse (although arbitrary) rules, which vary qualitatively with respect to species appearance mode, whether by speciation or by immigration, and quantitatively with respect to their rates of introduction into the community. Combining these criteria arises a great range of approaches for assembly models, each with its own limitations and questions, but contributing in a complementary way to elucidate the mechanisms structuring natural communities. To present such approaches, still incipient as research fields in Brazil, to describe some methods of analysis and to discuss the implications of their assumptions for the understanding of ecological patterns are the objectives of the present review.