Phenomenon In Life Cycle Research Articles

Multiscale oscillations of the annual course of temperature affect the spawning events of rudd (Scardinus erythrophthalmus)

Identifying climate impacts on ecosystems and their components requires observing time series of sufficient length to ensure adequate statistical power and reasonable coverage of the historical range of variability inherent in the system. The complexity of the hierarchy of climate effects reflected in temporal patterns in time series creates a need to be accurately modeled. The life cycle phenomena of living organisms, including fish spawning, have the character of one-time or time-limited events in time. An approach to finding the relationship between continuous components of time dynamics of environment properties and life cycle events of living organisms was proposed. This approach allowed us to evaluate the role of temperature patterns in the phenology of spawning rudd (Scardinus erythrophthalmus Linnaeus, 1758) in the Dnipro River basin water bodies. The atmospheric temperature time series may be decomposed into the following components: trend, annual cycle, episodic component, harmonic component, extreme events, and noise. Systematically low water temperatures at the beginning of the spawning period were observed in the Protoka River system and the Obukhov floodplain, and systematically elevated temperatures were recorded in the Dnipro River. The annual temperature dynamics was shown to be presented as a composition of oscillatory processes of different scale levels. The sinusoidal trend was previously extracted from the temperature series data. The average annual temperature, amplitude, and phase shift were calculated on the basis of the sinusoidal regression model. The residuals of the sinusoidal trend were processed by means of redundancy analysis with variables derived from symmetric distance-based Moran’s eigenvector maps as explanatory predictors. A set of 104 orthogonal dbMEM variables was extracted from the annual time series. These temporal variables were divided into the broad-, medium-, and fine-scale components. The parameters of temperature dynamics and biotope type are able to explain 51–72% of variability of spawning event. The time of spawning in water bodies corresponds to the time of spawning start: the earlier spawning starts, the earlier it ends. The duration of the spawning season is influenced by the patterns of different scale levels, as well as the amplitude and shift of phases. In this case, the duration of spawning in all water bodies does not differ. Spawning temperature depends on medium- and fine-scale temperature patterns, but does not depend on the characteristics of the sinusoidal annual trend. The annual temperature variation has been shown to be such that it can be decomposed into a sinusoidal trend, patterns of a multiscale nature, and a random fraction. Over the time range studied, the trend of increasing mean annual temperature was not statistically significant for spawning events. The sinusoidal trend explains 78.3–87.6% of the temperature variations and depends on the mean annual temperature, the amplitude of temperature variations during the year, and the earlier or later seasons of the year. Amplitude and phase shift play a role in describing spawning phenology. The residuals of the sinusoidal trend have been explained using dbMEM variables. This variation was decomposed into large-scale, medium-scale, and small-scale components. Winter and spring temperature fluctuations prior to spawning initiation had the greatest effect on spawning. Water temperature determines the lower possible limit for the start of spawning, but the actual start of spawning is determined by the preceding temperature dynamics. The results of the study have implications for understanding the dynamics of fish populations and assessing the influence of environmental conditions on the harmonization of the various components of ecosystems.

Pre-service Elementary Science Teacher Preparation through Children’s Literature

We investigated pre-service elementary teachers’ engagement in science and English language arts (ELA) instruction integrated in the context of a children’s book. Teachers developed models and conducted a compare-and-contrast analysis after exposure to different accounts of the butterfly life cycle: a popular children’s book, The Very Hungry Caterpillar, and a scientific account from National Geographic called “Butterfly: A Life.” The mixed-methods research was guided by the following question: What are the affordances and limitations of children’s literature toward engendering an understanding of the butterfly life cycle for pre-service elementary teachers? Content analysis indicated that pre-service elementary teachers’ abilities to compare and contrast the two accounts were not exceptional, as they failed to discriminate between ideas offered in the accounts and missed details of the key aspect of the butterfly life-cycle phenomenon: metamorphosis. However, the quality of participants’ butterfly life-cycle models significantly increased after exposure to the scientific account. We suggest the potential for an additional ELA standard, asking and answering such questions as who, what, where, when, why, and how to demonstrate understanding of key details in a text, as a means for enhancing compare-and-contrast skills following these activities.

Optimization of EOQ Model for New Products Under Multi-Stage Adoption Process

The available literature on new product sales growth models mostly ignores two important aspects of technology diffusion: diffusion of awareness and the actual adoption. This characteristic of technology adoption is extremely important from inventory management perspective as buying decision is often influenced due to time lag between information propagation and actual adoptions. As high-technology market is extremely unpredictable, interactions between technological evolutions and customer feedback effects play an important role in technology diffusion. The demand models mostly considered in inventory literature to develop economic order quantity (EOQ) model ignore this important element of technology diffusion. In this paper, we proposed an EOQ model for high-technology products by incorporating customer feedback effects along with market heterogeneity to optimize the total inventory cost. The demand model considered in the paper follows lifecycle phenomenon and is sensitive to unit selling price. To remove any ambiguity pertaining to costs, fuzzy nature of ordering and inventory carrying cost is considered in the paper.

Optimisation of fuzzy EOQ model for advertising and price sensitive demand model under dynamic ceiling on potential adoption

ABSTRACTMarketing strategies such as advertising and pricing can play an important role in the acceptance of technology products by consumers. This phenomenon indicates that diffusion of technology products in the society may have strong linkages with unit selling price and advertisement effort. Therefore, management should sincerely reflect on pricing and advertising strategy during formulation of the inventory policies. This paper aims to develop an economic order quantity model for finding strategy for a firm that sells technology products' over a finite planning horizon. Demand is considered to follow a lifecycle phenomenon with dynamic ceiling on the potential adoptions and sensitive to advertising expenditure and unit selling price. The fuzzy criterion has also been incorporated to address the problems of uncertain nature of marketing parameters. The model is illustrated with a numerical example and a comprehensive sensitivity analysis of the optimal solution with respect to different parameters has also been performed.

Introduction: The Mediterranean Voyage

Introduction: The Mediterranean Voyage

Does Profit Maximization Impact Sustainability? - An Examination

This paper examines the relationship between profit maximization and sustainability within the framework of the life cycle phenomenon for a corporation. It appears a pattern becomes the norm regarding business entities as well as other organizational forms regarding sustainability.

Workforce Planning over the Service Life Cycle

Services usually have a limited life under modern conditions of competition. The life cycle phenomenon is characterized by time-varying demand and a learning curve of workforce efficiency, making it difficult to determine staffing requirements. This paper initiates a study of the service life cycle phenomenon, from which the learning curve is found to be manageable through workforce planning. Therefore, optimal control is employed to model workforce planning over a service life cycle. An iterative approach is developed, allowing for an optimal trajectory of staff size that can be efficiently identified. Results from this study suggest that the learning curve should be considered in service workforce planning if the learning process lasts sufficiently long, in comparison to the service's life. Under such conditions, staffing requirements are determined by the dynamics of demand, workforce efficiency, and learning efficiency. Compared to the practice of allowing learning to occur autonomously, the control approach has the ability to strategically turn a small incremental investment in service workers into attractive savings in life cycle costs. Merits of the proposed methodology are also highlighted by its robustness in various life cycle conditions. This paper establishes a foundation for studying advanced problems, including training of a service workforce under life cycle conditions, planning the workforce for a complex service system, and managing the workforce under the uncertainties in service delivery, demand, learning, and turnover. [Service Science, ISSN 2164-3962 (print), ISSN 2164-3970 (online), was published by Services Science Global (SSG) from 2009 to 2011 as issues under ISBN 978-1-4276-2090-3.]

Historical lessons to watch your assumptions about aging: relevance to the role of International Psychogeriatrics

For too long, too many in science and society alike viewed aging as offering little that was of value. There was a collective illusion of knowledge that aging was characterized by inevitable, unalterable decrements in functioning that led to a dismal destiny in later life. This was a widespread perspective on aging, especially in the scientific community. To the extent that scientists considered aging as a wasteland of scientific opportunity, they had little interest in studying it. By not studying aging, little new was discovered about it, thereby preserving negative assumptions about what later life held for all of us. Both Freud and Piaget, for example, viewed development of the mind as essentially a first quarter of the life-cycle phenomenon – psychologically for Freud, intellectually for Piaget (Freud, 1978; Piaget, 1972).

Lean, six sigma and lean sigma: fads or real process improvement methods?

PurposeThe purpose of this paper is to explore if six sigma and lean are new methods, or if they are repackaged versions of previously popular methods – total quality management (TQM) and just‐in‐time (JIT).Design/methodology/approachThe study is based on a critical comparison of lean with JIT and six sigma with TQM, a study of the measure of the publication frequency – the number of academic articles published every year of the previous 30 years – for each topic, and a review of critical success factors (CSF) for change efforts.FindingsThe more recent concepts of lean and six sigma have mainly replaced – but not necessarily added to – the concepts of JIT and TQM. lean and six sigma are essentially repackaged versions of the former, and the methods seem to follow the fad (product) life cycle. The literature offers fairly similar and rather general CSF for these methods, e.g. top management support and the importance of communication and information. What seems to be missing, however, is the need for a systemic approach to organizational change and improvement.Practical implicationsA prediction is, given the fad or product life cycle phenomenon, that there will be a new method promoted soon, something perhaps already experienced with the borderline preposterous concept of lean six sigma. On the other hand, based on the gap in time between both JIT and lean, and TQM and six sigma – a gap filled by BRP/reengineering – the next method will be process oriented. This paper concludes with the discussion of the need for a process‐based approach to organizational improvement efforts.Originality/valueThis paper is of value in that it analyzes what lessons can be learnt from organizational change and improvement efforts. The analysis includes a comparison of CSF for any change project before discussing the need for a process (systems) perspective for successful organizational improvement efforts.

When does the majority become a majority? Empirical analysis of the time at which main market adopters purchase the bulk of our sales

The idea of a dual-market structure in the early stages of a product's life cycle has become one of the most widely accepted ideas among new product marketing practitioners in the past decade. Concepts such as “Early Market/Main Market” and “Visionaries/Pragmatists” have entered the lexicon of high-tech executives to express the notion that the market for new products is composed of early and main markets with a discontinuity in the diffusion process in between them. Moreover, these concepts have been at least partially tested and verified in the marketing academic literature in the past few years. We extend this branch of research by investigating the timing issues in dual-market cases. We define Change-of-Dominance Time (CD-Time) as the number of years it takes main market adopters to outnumber early market adopters. We empirically investigate this timing issue on a comprehensive data set of new product sales in the consumer electronics industry. We find that regarding explanatory determinants of CD-Time, external influence, such as advertising, to the early market is the most important explanatory variable. We examine the relationship between CD-Time and other early product life cycle phenomena: Takeoff, Saddle, and Rogers' size of adopter categories. We found relatively high correlations between these phenomena and CD-Time. The answer to the question “When does the majority become a majority?” is indeed “at 16%”! In a dual-market setting, the average time at which the main market outnumbers the early market is when 16% of the market has already adopted the product. In terms of time, in 75% of the cases the majority becomes a majority in 5 to 10 years.

Modeling Pfiesteria piscicida population dynamics: a new approach for tracking size and mass in mixotrophic species

We have developed a generalized dynamic, numerical model to study Pfiesteria popu- lation dynamics based on available observations and literature. We have incorporated formulations into this model which allow us to track changes in cell size in relation to food availability and other environmental conditions, which can be used for modeling a variety of cell-size dependent physio- logical functions. With this model, we are able to follow the time dependency of both individual size and abundance of Pfiesteria zoospores in cultures. We also have developed a general, starvation- based trigger mechanism for cyst formation for mixotrophic species like Pfiesteria, which is based on the size of zoospores determined by previous food conditions and the decrease or increase in size determined by the current food conditions. The model results suggest that zoospore concentration can be regulated effectively by both bottom-up control by food availability and the top-down control by zooplankton grazing. Model sensitivity analysis shows that the results are fairly robust with respect to changes in the model parameter values. This paper represents a significant step forward in our efforts to model complicated life-cycle phenomena in dinoflagellates like Pfiesteria and, in so doing, also provides some important new approaches for tracking cell size and cyst formation.

Generational and age-based differences in attitudes towards jury service.

Analysis of surveys of jurors, potential jurors, and the general public show significant differences in attitudes towards jury service by the age of the respondent. This study analyzes the degree to which these differences are the result of generational effects, in which younger citizens are likely to continue in their beliefs about jury service as they age, and the degree to which they are a result of a respondent's life circumstances-income, employment status, or family status-and are thus not likely to be carried with jurors as they age. The article shows that, while there are differences in confidence in the courts by age group, younger jurors are more confident in their own abilities to serve well as jurors but more skeptical of the court as a whole; most differences in attitudes towards jury service are linked to life-cycle phenomena. As such, courts should work to provide assistance to particular age groups within the jury pool, including child care and appropriate compensation, if they are to attract jurors who are representative by age of the general public.

A computational model of economies of scale and market share instability

Replicator dynamics and computer simulation techniques are used to construct a reduced-form model which explores negative and positive feedback between the rate of a firm's cost reduction and its market share (‘dynamic’ returns to scale). Life-cycle phenomena are explored by combining positive and negative feedback in a firm's cost function. The objective of the model is to reproduce the patterns of concentration and instability found across a wide set of industries. Simulation results find that dynamic decreasing returns to scale produce instability and multiple equilibria in market shares, very different from the results generated from ‘static’ decreasing returns to scale.

The senescence of oat leaf segments is promoted under simulated microgravity condition on a three-dimensional clinostat.

Plants have evolved on the earth, indicating the morphology, growth and development, and life cycle of plants are highly influenced by gravity as well as other environmental stimuli. Indeed, simulated microgravity on a clinostat or hypergravity on a centrifuge has recently been reported to change the growth and development of plants (Hoson et al. 1992, 1993, 1995, Rasmussen et al. 1994, Kasahara et al. 1995). Senescence is a final drastic phenomenon in life cycle of plants, which is characterized by the loss of total chlorophyll and protein, and/or the formation of the abscission (Osborne 1973, Thimann 1977, Addicott 1982). Many environmental stimuli as well as the qualitative and quantitative changes of plant hormones have been reported to affect plant senescence. Among those stimuli, light is the most important factor to regulate plant senescence (Leopold 1964). Dark condition promotes leaf senescence due to the decrease in endogenous level of cytokinin and/or the increase in that of abscisic acid or ethylene (Tetley and Thimann 1974, Gepstein and Thimann 1980). However, there are few reports concerning the effect of gravity on leaf senescence. Strenuous effort to learn leaf senescence under microgravity condition has been done using a three-dimensional (3-D) clinostat. In this paper, we report that simulated microgravity condition on a 3-D clinostat promoted the senescence of oat leaf segments in the dark. A possible mechanism of microgravity condition on promoting the senescence is also discussed.

A household life cycle model for residential relocation behaviour

In this paper a dynamic household model in connection with a comprehensive urban housing market model for Amsterdam is presented. Household dynamics is modelled here by using the methodology of multidimensional demography. A consistent analysis of the components of a dynamic spatial housing market system incorporating various submodules, multiple factors, spatial aggregation levels and degrees of precision of available data requires the use of an accounting framework. The paper shows the analytical structure and empirical estimation of an accounting model developed for investigating the dynamics on an urban housing market, with a particular focus on changes in household compositions caused by the household life cycle phenomenon. The linkage between the life cycle concept and the demand on the housing market is established by using an explanatory nested logit model. Apart from the few exceptions in a more limited context, this is a rather unique attempt at modelling, in a consistent way, the dynamic allocation of household demand for dwellings in a zonal urban system based on a large-scale socio-economic data set concerning spatial residential relocation behaviour in Amsterdam. On the basis of the empirical outcomes obtained, of various model testing procedures, and of a comparison of observed and predicted outcomes, this housing market model appears to reproduce housing market developments in the past satisfactorily, so that it can likely be used as a tool for predicting future paths of urban housing market demand.

A Diffusion Model Incorporating Product Benefits, Price, Income and Information

We start by assuming that a major benefit of many new durable products such as dishwashers and microwave ovens is time savings. Others, such as VCRs, also enhance the value of our leisure time. Using a household production framework we demonstrate that a utility maximizing individual will have a reservation price for the product which is a function of the product benefits and his wage rate. By assuming that the wage rate has an extreme value distribution across the population, we are able to derive, for the aggregate process, an income-price dependent logistic adoption equation. We then allow for the possibility that certain eligible consumers may delay their purchase of the product because they are unaware that it exists, are suspicious of its quality, or expect its price to fall. Unawareness, uncertainty and hope for further price declines are assumed to decrease with the increase in the number of previous adopters. The resulting diffusion model has the property that the product life cycle phenomenon can be explained jointly or separately by the income-price process, and the awareness-uncertainty-expectations process. Using data on household income, on durable penetration within different income classes, and on first-purchase sales the aggregate diffusion model and its premises are tested and supported. It is found that both the income-price and awareness-uncertainty-expectations processes are at work. However, the dependence of the awareness-uncertainty-expectations delay process on the number of previous adopters (e.g., word-of-mouth type effect) exists only in certain product categories and is usually relatively weak. It is demonstrated that if the word-of-mouth type effects are weak, a price skimming strategy is optimal for a monopolist and also is likely to be implemented by oligopolists. The sales forecasting implications of the model also are pursued.

Habitual routines in task-performing groups

Groups, like individuals, often develop habitual routines for dealing with frequently encountered stimuli. Although such routines are consequential for group life and work, little is known about them. This paper reconnoiters the territory of habitual behavior in groups that perform work within organizations. We offer a definition of group habits, identify their functions and dysfunctions, suggest how they develop and are maintained, and identify the circumstances when they are likely to be altered or abandoned. Throughout, we give special attention to the social nature of habitual routines in groups, to the interaction between habitual behavior and group life cycle phenomena, and to the role of the organizational context in prompting, shaping, and terminating habitual routines.

Ecological investigations of blooms of colonial Phaeocystis pouchetti. II. The role of life-cycle phenomena in bloom termination

Ecological investigations of blooms of colonial <i>Phaeocystis pouchetti</i>. II. The role of life-cycle phenomena in bloom termination

A study of reproduction and other life cycle phenomena in planktonic protists using an acridine orange fluorescence technique

The percentage of dividing individuals and temporal reproductive patterns were determined for natural populations of several planktonic protists including five species of tintinnids, a dinoflagellate, and a diatom. To obtain these data, a method was used in which the nuclei of planktonic ciliates and phytoplankters can be fluorescently stained with acridine orange at the time of collection and fixation. The technique is simple and can be used routinely in studies of reproduction or other life cycle phenomena of natural protistan populations. For the tintinnids, often more than half of the individuals were in some recognizable stage of fission; periodicity in the division process was only observed once and apparently followed a pulse of conjugation in the population. With the diatom Ditylum brightwellii the fluorescent staining technique yielded data on the extent and timing of division which were consistent with, but more complete than, previous enumerations of paired cells.

Advertising Budgeting, Wearout and Copy Replacement

In this paper we offer a formulation for the Copy Life Cycle phenomenon. In particular, we introduce simultaneously three decision variables, the optimal advertising expenditures during a given planning horizon, the optimal times for copy replacements and the optimal investments in the new copies. The analysis and the solution of the problem is carried out by a mixed optimization technique based on dynamic programming and optimal control theory.