Individual Life Cycle Research Articles

In Search of Systems “DNA"

General Systems Theory (GST) has been an attempt to put precision into the term system thereby making intelligent communication between its users more attractive, something that provides for migration of ideas and the possible resolution of issues by borrowing solutions from unfamiliar domains. We propose to build on GST and in particular, as von Bertalanffy once did, draw on the biological sciences, now hugely advanced beyond that ever imagined by von Bertalanffy and his peers, and use its findings, architectures and emergent behaviors, to argue for a biology of technology and enterprise systems. We do so by expanding on a system of “togetherness characteristics” and in particular explain how these can be applied to better understand familiar systems, e.g. the automobile, and how such systems form part of diverse wider communities (or containing systems). We seek a science and approach that we believe will provide richer insight into system failure, 'health' maintenance, repair, replication, growth, and mutation, all those features of the evolution of systems which constantly challenge us and which thus far we have only been able to explain via macro-level models and tools. We propose to go deeper into the structure of these systems and to discover the DNA (building blocks) of these systems. Thus establishing a foundation to understand their behavior using biological analogies which we believe will turn out to be more than metaphors. We assert that these systems have micro-structures which will explain their individual life cycle and their communal ecology.

The Life-Course Perspective and Social Policies: An Overview of the Issues

A number of trends are changing the nature of social risks and increase the importance of human capital, adaptability and flexibility. This paper discusses the usefulness of a lifecourse perspective in developing proactive social policies that better fit the changing life cycles of individuals who combine formal work with other activities on transitional labor markets. It pays special attention to the accumulation and maintenance of human capital over the life course and stresses that reconciliation of work and family goes beyond childcare facilities and parental leave, and involves the entire life course. In particular, longer and deeper involvement in paid employment allows people to exploit their longer life to reconcile the two ambitions of, first, investing in the next generation as a parent and, second, pursuing a fulfilling career in paid work in which one keeps learning. Greater flexibility of working time over the life course requires more individual responsibility for financing leave. Moreover, rather than shielding older insiders through employment protection, labor-market institutions should enable parents of young children to easily enter and remain in the labor market. Finally, more activating social assistance and inwork benefits should replace the passive income support for breadwinners that results in high minimum wage floors.

Development and validation of an individual based Daphnia magna population model: The influence of crowding on population dynamics

An individual-based model was developed to predict the population dynamics of Daphnia magna at laboratory conditions from individual life-history traits observed in experiments with different feeding conditions. Within the model, each daphnid passes its individual life cycle including feeding on algae, aging, growing, developing and – when maturity is reached – reproducing. The modelled life cycle is driven by the amount of ingested algae and the density of the Daphnia population. At low algae densities the population dynamics is mainly driven by food supply, when the densities of algae are high, the limiting factor is “crowding” (a density-dependent mechanism due to chemical substances released by the organisms or physical contact, but independent of food competition). The model was calibrated using data from life cycle tests at flow-through conditions with different levels of algae concentrations. In addition to the average life cycle parameters for different food levels, the variability between the individuals was considered by stochastic assignment of values from the observed distributions in the experiments to each individual property. The model was tested on the individual and the population level. Individual growth and reproduction were tested based on the results of life cycle tests conducted under semi-batch conditions; the population level was considered by testing at different food levels under flow-trough and static conditions, including extinction at starvation conditions. The model was not only able to predict the total abundance of the population over time, but also predicted the size structure in good accordance with the observations. The population dynamics emerge directly from the life cycle of the individual daphnids. It depends on the available food and–this had not been considered in other Daphnia models–on crowding effects due to high Daphnia abundances.

The Bare Bones of Race

In this paper I examine claims of racial difference in bone density and find that the use and definitions of race in medicine lack a theoretical foundation. My central argument is that the social produces the biological in a system of constant feedback between body and social experience. By providing a different angle of vision on claimed racial differences I hope to move the conversation away from an ultimately futile discussion of nature versus nurture, where time is held constant and place seen as irrelevant, and begin to build a new paradigm for examining the contributions of geographic ancestry, individual lifecycle experience, race, and gender to varied patterns of health and disease.

The Life-course Perspective and Social Policies: An Overview of the Issues

A number of trends are changing the nature of social risks and increase the importance of human capital, adaptability, and flexibility. This article discusses the usefulness of a life-course perspective in developing proactive social policies that better fit the changing life cycles of individuals who combine formal work with other activities on transitional labor markets. It pays special attention to the accumulation and maintenance of human capital over the life course and stresses that reconciliation of work and family goes beyond child care facilities and parental leave, and involves the entire life course. In particular, longer and deeper involvement in paid employment allows people to exploit their longer life to reconcile the two ambitions of, first, investing in the next generation as a parent and, second, pursuing a fulfilling career in paid work in which one keeps learning. Greater flexibility of working time over the life course requires more individual responsibility for financing leave. Moreover, rather than shielding older insiders through employment protection, labor market institutions should enable parents of young children to easily enter and remain in the labor market. Finally, more activating social assistance and in-work benefits should replace the passive income support for breadwinners that results in high minimum wage floors. (JEL codes: H30, J10, J20)

‘Settling back’? A biographical and life-course perspective on Ireland's recent return migration

Abstract This paper uses a biographical and life-course perspective to explore some of the key narratives of return among return migrants to Ireland, focusing in particular on the themes of family, child-rearing, relationship breakdown and ‘settling down’. The ways in which return migrants use the concept of life-course transitions in order to make sense of and narrate their migration stories is explored. I argue that their narratives reflect a normative association of life stage with place, and that return migration reflects the ways in which key events in the individual life course transitions and family life cycles of 1980s emigrants have intersected with processes of economic and social transformation in Ireland. This occurs within the context of heteronormative and kinship-based ideals of Irish culture and of powerful myths of return. The data used in the paper is taken from the Narratives of Migration and Return research project, a north–south cross-border project which assembled an oral archive of 92 return migrant life narratives. In the paper, I draw on 33 of the interviews conducted in the south, which focused on the cohort of return migrants who had emigrated in the 1980s.

Regional inequality in Spain: permanent income versus current income

The literature on inequality among economies has focused mainly on analysing the dispersion of indicators such as current income per capita. In this paper we adopt a different approach from the usual one. In order to analyse inequality and convergence among Spanish regions, we propose to use a measure of permanent income that takes into account the entire life cycle dimension. On the basis of this approach, we make various simulations to determine the influence on inequality and convergence in permanent income of variables, such as survival rates and the existence or non-existence of convergence in current income. The results indicate that inequality in permanent income is clearly lower than that observed when the full life cycle of individuals is not taken into account.

A Comparative Life Cycle Analysis of Two Different Juice Packages

Packaging wastes have a portion of 12–15% in total municipal solid waste (MSW) in Turkey, and they have to be evaluated from production to final disposal from the environmental point of view. The concern about the environmental impacts of packages has been dealt with using several approaches in environmental management, such as risk assessment, environmental impact assessment, environmental auditing, energy analysis, material flow analysis, and life cycle analysis (LCA). The main purpose of this research was to investigate the life cycle environmental impact of glass bottles and beverage cartons. This LCA study was performed by using SimaPro7 (PRè Consultants, The Netherlands) software. Individual and comparative life cycle analysis of two packages was performed depending on a consumer who lives in Eskisehir city. For that aim, SimaPro7 was used, and the data to run the software was gathered from package producers, the database of the software, and the literature. Life cycle comparisons of the two juice packages among themselves and also within themselves were carried out by using EcoIndicator 99 on the basis of climate change, ecotoxicity, acidification/eutrophication, and fossil fuels. Sensitivity analysis was performed to evaluate the effects of transportation. According to comparison figures, the environmental load of glass bottles is higher than beverage carton's load for all the impact categories. This result is also supported by the sensitivity analysis.

Defect classification for mechatronic products

Modern investment goods such as commercial vehicles show a rise in complexity due to an increase in mechatronic elements. As a result, such products are more sensitive to defects, often reflected in reduced reliability during product usage. Therefore, reliability is a quality feature that is gaining more importance throughout the entire product life cycle (PLC). However, rather than considering the complete PLC, traditional quality assurance techniques typically focus on individual life cycle phases. The following paper thus proposes a new approach for closing the resulting gap. Adapting a technique originating from the domain of software engineering for the life cycle of mechatronic products enables a consistent classification of product defects. Based on this classification, proper means for quality improvement can be developed and implemented. Consequently, an evolutionary increase in reliability becomes possible.

Cooperation and coordination among siblings: Brothers' migration in France, 1870–1940

Recent works emphasize the role of the family in migration decisions. They particularly insist on the specific schedule of mobility that depends not only on an individual life cycle but also on the situation of the whole family at a given time. French military registers provide us with very detailed longitudinal information on migrations, scarcely available in other sources. We consider the smallest family group, male siblings, and focus on their migration behaviours. We start by testing the simplest family indicator, birth rank, and we show that, by itself, it has no effect on migration decisions. We then study whether or not there is competition among siblings and, in particular, if the migration of one of them encourages or prevents mobility of the others. Comparing the chances for an individual to move before and after the migration of his brother, we show that brother mobility did have a positive influence on someone's own mobility. However, we find little evidence of the use of networks when looking at migrants' place of destination. Sons are more prone to move in a given family than in another but they don't go to the same places. Therefore, we argue that mobility appears as a collective decision that depends on family strategies. This approach sheds new light on the migration process while insisting on its family component.

Developmentally regulated expression, alternative splicing and distinct sub-groupings in members of the Schistosoma mansoni venom allergen-like (SmVAL) gene family.

BackgroundThe Sperm-coating protein/Tpx-1/Ag5/PR-1/Sc7 (SCP/TAPS) domain is found across phyla and is a major structural feature of insect allergens, mammalian sperm proteins and parasitic nematode secreted molecules. Proteins containing this domain are implicated in diverse biological activities and may be important for chronic host/parasite interactions.ResultsWe report the first description of an SCP/TAPS gene family (Schistosoma mansoni venom allergen-like (SmVALs)) in the medically important Platyhelminthes (class Trematoda) and describe individual members' phylogenetic relationships, genomic organization and life cycle expression profiles. Twenty-eight SmVALs with complete SCP/TAPS domains were identified and comparison of their predicted protein features and gene structures indicated the presence of two distinct sub-families (group 1 & group 2). Phylogenetic analysis demonstrated that this group 1/group 2 split is zoologically widespread as it exists across the metazoan sub-kingdom. Chromosomal localisation and PCR analysis, coupled to inspection of the current S. mansoni genomic assembly, revealed that many of the SmVAL genes are spatially linked throughout the genome. Quantitative lifecycle expression profiling demonstrated distinct SmVAL expression patterns, including transcripts specifically associated with lifestages involved in definitive host invasion, transcripts restricted to lifestages involved in the invasion of the intermediate host and transcripts ubiquitously expressed. Analysis of SmVAL6 transcript diversity demonstrated statistically significant, developmentally regulated, alternative splicing.ConclusionOur results highlight the existence of two distinct SCP/TAPS protein types within the Platyhelminthes and across taxa. The extensive lifecycle expression analysis indicates several SmVAL transcripts are upregulated in infective stages of the parasite, suggesting that these particular protein products may be linked to the establishment of chronic host/parasite interactions.

Vergrijzing, levensfasebeleid en de cao

Ageing, life cycle management and collective labour agreements Ageing, life cycle management and collective labour agreements Solutions for issues with respect to ageing are often searched for in Collective Labour Agreements (CLA). This article investigates the necessary conditions for concluding arrangements for ageing in a CLA. First the influence of government on the degrees of freedom of social partners is explored from the viewpoint of institutional economics. Next, the theoretical conditions are mapped that negotiating parties in companies can develop themselves, from the perspective of transaction costs, agency or stewardship. The various approaches are illustrated with some facts about Dutch CLAs. It appears that the management of individual life cycles is more appropriate as a concept than the issue of ageing. In a survey of 564 Dutch CLAs the aspects of a life cycle approach are listed. In the discussion the limitations of the present analysis are reviewed, the conditions are summarized, possibilities for further research are indicated. The conclusion is that under certain conditions the CLA can contribute to the management of one’s life course.

CGMP kinase and food-related behaviours

The repeated incorporation of common gene activities and pathways into diverse behavioural and environmental contexts throughout evolution is similar to findings in developmental biology showing that principle regulators have been co-opted to generate novel patterns [1]. Nevertheless, such genetic systems must be flexible enough to generate adaptive phenotypes in the midst of unique environmental and developmental constraints. For the foraging gene which encodes a cGMP dependent protein kinase (PKG), variation in gene activity has been associated with distinct alleles within populations in some species (e.g. D. melanogaster) and developmental transitions over the lifecycle of single individuals in others (e.g. honeybees [2] and ants). Here we show that the foraging gene in Drosophila also plays a role in behavioural plasticity within the lifetime of the individual. foraging affects food-related locomotion, food intake, responses to food deprivation, energy homeostasis, sucrose responsiveness [3] and learning. Recent immunohistochemical analysis of for expression combined with behaviour genetic analysis enables us to begin to draw parallels between PKG function in invetebrates and mammals.

Heterogeneity of individual roots within the fine root architecture: causal links between physiological and ecosystem functions

This review covers the heterogeneity in functions within the fine root architecture in order to clarify the multiple functions of fine roots. Many fine root characteristics, such as anatomy, physiology, morphology, and their consequences for the ecosystem, differ among root ages and ontogenetic branching hierarchies. Individual root age can be characterized by tissue development, with the main tissues developing from primary to secondary tissues. The physiological characteristics of individual roots, such as absorptivity and respiration rates, decrease with increasing branching order, mainly because of aging and tissue development. The C/N ratio and lignin and suberin contents also increase with branching order because of root aging. Morphological characteristics, such as diameter and specific root length, differ among root orders because of both aging and ontogenetic differences. The mortality of individual roots differs among branching orders and root diameters. The life cycles of roots in the fine root architecture, that is, ephemeral and perennial, indicate ontogenetic differences in functions and demographic traits, similar to those for leaves and branches in shoots. In addition, differences in individual root life cycles may affect the root chemical composition, in turn, affecting the decomposition rate. Future studies should seek to identify heterorhizic units in mortality related to anatomical, physiological, and morphological differences for various species. The decomposition processes of each mortality unit within the fine root architecture are also important in understanding the link between physiological and ecosystem functions.

Feather deuterium measurements reveal origins of migratory western loggerhead shrikes (Lanius ludovicianus excubitorides) wintering in Mexico

ABSTRACTUnderstanding the winter distributions of migrant birds is important because productivity and recruitment are influenced by conditions at several locations and periods in the life cycle of individuals. The western loggerhead shrike, Lanius ludovicianus excubitorides, is a threatened species in Canada, and its decline is attributed to potential limitations on the wintering grounds. We examined patterns of stable‐hydrogen isotope (δD) distributions in feathers of loggerhead shrikes, primarily of L. l. excubitorides, during winter at three regions in north and central Mexico, to establish relative abundance and origins of migrants. We also investigated potential movements of Mexican winter resident individuals. Using shrike museum specimens of known summer provenance, a shrike deuterium base map for Mexico was developed from isotopic measurement of feathers of resident shrikes and use of a recently established feather base map for raptors in North America. Stable hydrogen isotope analyses of inner secondary feather (s9) of all loggerhead shrikes examined in Mexico during winter indicated that north‐central (Region A), north‐eastern (Region B) and south‐central (Region C) sites in Mexico consisted of 28.1%, 73.7% and 63.8% of migrant individuals from northern breeding grounds, respectively. Isotopic evidence suggested movements of a few local residents birds (7.9%) into the Chihuahuan desert from south‐western USA and north‐eastern Mexico to winter.

Optimal Annuity Risk Management

We study the optimal consumption and portfolio choice problem over an individual's life-cycle taking into account annuity risk at retirement. Optimally, the investor allocates wealth at retirement to nominal, inflation-linked, and variable annuities and conditions this choice on the state of the economy. We also consider the case in which there are, either for behavioral or institutional reasons, limitations in the types of annuities that are available at retirement. We allow for the possibility of a government-provided annuity income. Subsequently, we determine how the investor optimally anticipates annuitization before retirement. We find that (i) using information on both term structure variables and risk premia significantly improves the annuity choice, (ii) annuity market incompleteness is economically costly, and (iii) adjustments in the optimal investment strategy before retirement induced by the annuity demand due to inflation risk and time-varying risk premia are significant in economic terms. This latter result holds as well for sub-optimal annuity choices. The adjustment to hedge real interest rate risk is negligible.

Human Capital over the Life Cycle: A European Perspective

This book makes a novel contribution to economics of education several key respects. It highlights a broad number of crucial factors over the individual's life cycle that underlie inequalities education and the labour market... It is amazing how limited our knowledge is about these interactions despite their high priority national as well as EU-level policy-making. This is a timely book concerned with topics of high policy relevance. Moreover, the authors have well succeeded their attempt to write in a style that makes this work accessible to a wider audience, using the editor's words. It is most important that academics as well as politicians are made aware of the considerable knowledge gaps that still prevail our understanding of the role of education and training for the individual's success or failure school and working life.

The mobility of university inventors in Europe

This paper analyses university patenting and academic mobility based on information in the PatVal database on European inventors in six European countries. We show that university participation in patenting activity is grossly underestimated when assessed on ownership exclusively: university-owned patents account for only 15% of patents with at least one academic inventor. Academic mobility is unevenly distributed across technologies (most is in biomedics) and across countries (mainly the UK, Germany and the Netherlands). Descriptive evidence highlights the high levels of patenting and mobility of UK academic inventors. We analyse labour mobility from academia to business. Multinomial models show the presence of a strong individual life cycle effect on mobility. Moreover, there are important differences in what determines mobility towards other universities or businesses. Inventors with more valuable patents, which embody more tacit knowledge, are more likely to go to private organisations. Scientific productivity has no impact on the probability of moving.

An algorithm for a decomposition of weighted digraphs: with applications to life cycle analysis in ecology

In the analysis of organism life cycles in ecology, comparisons of life cycles between species or between different types of life cycles within species are frequently conducted. In matrix population models, partitioning of the elasticity matrix is used to quantify the separate contributions of different life cycles to the population growth rate. Such partition is equivalent to a decomposition of the life cycle graph of the population. A graph theoretic spanning tree method to carry out the decomposition was formalized by Wardle [Ecology 79(7), 2539-2549 (1998)]. However there are difficulties in realizing a suitable decomposition for complex life histories using the spanning-tree method. One of the problems is the occurrence of life cycles that contain contradictory directions that defy biological interpretation. We propose an algorithmic approach for decomposing a directed, weighted graph. The graph is to be decomposed into two parts. The first part is a set of simple cycles that contain no contradictory directions and that consist of edges of equal weight. The second part of the decomposition is a subgraph in which no such simple cycles are obtainable. When applied to life cycle analysis in ecology, the proposed method will guarantee a complete decomposition of the life cycle graph into individual life cycles containing no contradictory directions.

A semiotic framework for evolutionary and developmental biology

This work aims at constructing a semiotic framework for an expanded evolutionary synthesis grounded on Peirce's universal categories and the six space/time/function relations [Taborsky, E., 2004. The nature of the sign as a WFF—a well-formed formula, SEED J. (Semiosis Evol. Energy Dev.) 4 (4), 5–14] that integrate the Lamarckian (internal/external) and Darwinian (individual/population) cuts. According to these guide lines, it is proposed an attempt to formalize developmental systems theory by using the notion of evolving developing agents (EDA) that provides an internalist model of a general transformative tendency driven by organism's need to cope with environmental uncertainty. Development and evolution are conceived as non-programmed open-ended processes of information increase where EDA reach a functional compromise between: (a) increments of phenotype's uniqueness (stability and specificity) and (b) anticipation to environmental changes. Accordingly, changes in mutual information content between the phenotype/environment drag subsequent changes in mutual information content between genotype/phenotype and genotype/environment at two interwoven scales: individual life cycle (ontogeny) and species time (phylogeny), respectively. Developmental terminal additions along with increment minimization of developmental steps must be positively selected.