46 research outputs found
Temperature Influences Selective Mortality during the Early Life Stages of a Coral Reef Fish
For organisms with complex life cycles, processes occurring at the interface between life stages can disproportionately impact survival and population dynamics. Temperature is an important factor influencing growth in poikilotherms, and growth-related processes are frequently correlated with survival. We examined the influence of water temperature on growth-related early life history traits (ELHTs) and differential mortality during the transition from larval to early juvenile stage in sixteen monthly cohorts of bicolor damselfish Stegastes partitus, sampled on reefs of the upper Florida Keys, USA over 6 years. Otolith analysis of settlers and juveniles coupled with environmental data revealed that mean near-reef water temperature explained a significant proportion of variation in pelagic larval duration (PLD), early larval growth, size-at-settlement, and growth during early juvenile life. Among all cohorts, surviving juveniles were consistently larger at settlement, but grew more slowly during the first 6 d post-settlement. For the other ELHTs, selective mortality varied seasonally: during winter and spring months, survivors exhibited faster larval growth and shorter PLDs, whereas during warmer summer months, selection on PLD reversed and selection on larval growth became non-linear. Our results demonstrate that temperature not only shapes growth-related traits, but can also influence the direction and intensity of selective mortality
Contrasted Patterns of Molecular Evolution in Dominant and Recessive Self-Incompatibility Haplotypes in Arabidopsis
Self-incompatibility has been considered by geneticists a model system for reproductive biology and balancing selection, but our understanding of the genetic basis and evolution of this molecular lock-and-key system has remained limited by the extreme level of sequence divergence among haplotypes, resulting in a lack of appropriate genomic sequences. In this study, we report and analyze the full sequence of eleven distinct haplotypes of the self-incompatibility locus (S-locus) in two closely related Arabidopsis species, obtained from individual BAC libraries. We use this extensive dataset to highlight sharply contrasted patterns of molecular evolution of each of the two genes controlling self-incompatibility themselves, as well as of the genomic region surrounding them. We find strong collinearity of the flanking regions among haplotypes on each side of the S-locus together with high levels of sequence similarity. In contrast, the S-locus region itself shows spectacularly deep gene genealogies, high variability in size and gene organization, as well as complete absence of sequence similarity in intergenic sequences and striking accumulation of transposable elements. Of particular interest, we demonstrate that dominant and recessive S-haplotypes experience sharply contrasted patterns of molecular evolution. Indeed, dominant haplotypes exhibit larger size and a much higher density of transposable elements, being matched only by that in the centromere. Overall, these properties highlight that the S-locus presents many striking similarities with other regions involved in the determination of mating-types, such as sex chromosomes in animals or in plants, or the mating-type locus in fungi and green algae
Geographic genetic structure of Iberian columbines (gen. Aquilegia)
Southern European columbines (genus Aquilegia)are involved in active processes of diversification, and the Iberian Peninsula offers a privileged observatory to witness the process. Studies on Iberian columbines have provided significant advances on species diversification,but we still lack a complete perspective of the genetic diversification in the Iberian scenario. This work explores how genetic diversity of the genus Aquilegia is geographically structured across the Iberian Peninsula. We used Bayesian clustering methods, principal coordinates analyses, and NJ phenograms to assess the genetic relationships among 285 individuals from 62 locations and detect the main lineages. Genetic diversity of Iberian columbines consists of five geographically structured lineages, corresponding to different Iberian taxa. Differentiation among lineages shows particularly complex admixture patterns at Northeast and highly homogeneous toward Northwest and Southeast. This geographic genetic structure suggests the existence of incomplete lineage sorting and interspecific hybridization as could be expected in recent processes of diversification under the influence of quaternary postglacial migrations. This scenario is consistent with what is proposed by the most recent studies on European and Iberian columbines, which point to geographic isolation and divergent selection by habitat specialization as the main diversification drivers of the Iberian Aquilegia complex
The people dimension in manufacturing strategy: contextual factors influencing a joint view
This paper explicates the contextual factors influencing the workers’ perceptions of theMS, and hence, the possibilities for a joint view between workers and managers. Thepaper is based on in depth interviews with 16 workers in four metal working SMEs inSweden. The contextual factors can be viewed at two levels: individual andorganisational. This paper contributes to richer descriptions of what the individual andorganisational contextual factors incorporate, and to the clarification of the importantrole communication channels plays for the possibilities of a joint view. Thereby,contributing to increased knowledge on the manufacturing strategy formation process
The people dimension in manufacturing strategy: contextual factors influencing a joint view
This paper explicates the contextual factors influencing the workers’ perceptions of theMS, and hence, the possibilities for a joint view between workers and managers. Thepaper is based on in depth interviews with 16 workers in four metal working SMEs inSweden. The contextual factors can be viewed at two levels: individual andorganisational. This paper contributes to richer descriptions of what the individual andorganisational contextual factors incorporate, and to the clarification of the importantrole communication channels plays for the possibilities of a joint view. Thereby,contributing to increased knowledge on the manufacturing strategy formation process
Strategic Consensus in SMEs: Behavioral Operations Perspective on Manufacturing Strategy
Previous manufacturing strategy (MS) studies have to a limited extent incorporated the people dimension emphasized in the behavioral operations field. This paper aims to empirically examine the relationship between managers’ and operators’ perceptions of MS from a behavioral operations perspective. Interviews with both managers and operators at three Swedish metalworking small and medium enterprises (SMEs) were conducted. The results show a higher level of strategic consensus, compared to earlier research. Strategic consensus is primarily seen within the intra-organizational dimensions. Lack of consensus seems to be caused primarily by poor communication about strategic objectives and long-term plans. By emphasizing the people dimension of MS, this paper contributes to increased knowledge about strategic consensus at SMEs and the importance of strategic commitment and strategic consensus for a successful MS process
Strategic Consensus in SMEs: Behavioral Operations Perspective on Manufacturing Strategy
Previous manufacturing strategy (MS) studies have to a limited extent incorporated the people dimension emphasized in the behavioral operations field. This paper aims to empirically examine the relationship between managers’ and operators’ perceptions of MS from a behavioral operations perspective. Interviews with both managers and operators at three Swedish metalworking small and medium enterprises (SMEs) were conducted. The results show a higher level of strategic consensus, compared to earlier research. Strategic consensus is primarily seen within the intra-organizational dimensions. Lack of consensus seems to be caused primarily by poor communication about strategic objectives and long-term plans. By emphasizing the people dimension of MS, this paper contributes to increased knowledge about strategic consensus at SMEs and the importance of strategic commitment and strategic consensus for a successful MS process
Strategic consensus on manufacturing strategy content: including the operators\u27 perceptions
Purpose – Strategic consensus between operators and managers is an important means toaccomplish a successful manufacturing strategy (MS) process. Previous studies largely leftout individual operators from this concept. Therefore, the purpose of this paper was toempirically examine the level of strategic consensus on the MS within the operationsfunction, that is, the operators’ and managers’ perceptions of MS.Design/methodology/approach – Interviews were conducted with both operators andmanagers at three small and medium-sized enterprises in Sweden. The MS dimensions wereselected based on previous research; the data was analysed by using thematic coding.Findings – The study shows that the levels of strategic consensus on the MS vary amongcompanies. Even when strategic consensus exists between operators and managers, theirunderlying reasons often differ. Furthermore, the levels of strategic consensus vary amongMS dimensions. The companies’ usage of information-sharing channels, along with their sizeand position in the supply chain, can be important for the level of strategic consensus.Originality/value – This paper contributes to the body of knowledge in three ways. First, itexpands the scope of the MS dimensions under study, thus offering a stronger, resource-basedperspective on MS and strategic consensus than what earlier studies showed. Second, it goesbeyond the management level by including both managers and operators as the unit ofanalysis. Third, compared to previous research, it focuses on a new context and is based on indepthcase studies