Changing Patterns Of Relations Research Articles

Fluctuating climate and dietary innovation drove ratcheted evolution of proboscidean dental traits

Identification of the selective forces that shaped adaptive phenotypes generally relies on current habitat and function, but these may differ from the context in which adaptations arose. Moreover, the fixation of adaptive change in a fluctuating environment and the mechanisms of long-term trends are still poorly understood, as is the role of behaviour in triggering these processes. Time series of fossils can provide evidence on these questions, but examples of individual lineages with adequate fossil and proxy data over extended periods are rare. Here, we present new data on proboscidean dental evolution in East Africa over the past 26 million years, tracking temporal patterns of morphological change in relation to proxy evidence of diet, vegetation and climate (aridity). We show that behavioural experimentation in diet is correlated with environmental context, and that major adaptive change in dental traits followed the changes in diet and environment but only after acquisition of functional innovations in the masticatory system. We partition traits by selective agent, showing that the acquisition of high, multiridged molars was primarily a response to an increase in open, arid environments with high dust accumulation, whereas enamel folding was more associated with the amount of grass in the diet. We further show that long-term trends in these features proceeded in a ratchet-like mode, alternating between directional change at times of high selective pressure and stasis when the selective regime reversed. This provides an explanation for morphology adapted to more extreme conditions than current usage (Liem’s Paradox). Our study illustrates how, in fossil series with adequate stratigraphic control and proxy data, environmental and behavioural factors can be mapped on to time series of morphological change, illuminating the mode of acquisition of an adaptive complex.

Beyond pedagogy: the role of epistemic orientation and knowledge generation environments in early childhood science teaching

ABSTRACT Policy documents in many nations, as well as international policies indicate that the goal of improved student science learning requires teachers to learn to use knowledge generation environments for teaching science. This is a particular challenge for early childhood teachers (kindergarten through grade two), who have historically valued practices like active inquiry, but have received little Professional Development (PD) focused on theories of learning and orientations towards knowledge. This explanatory sequential quantitative study explored the relationship between 30 early childhood teachers’ Epistemic Orientations (EOs) and their use of knowledge generation practices for teaching science. In particular, we noted patterns of teacher change in relation to a multi-year PD programme focused on teaching through knowledge generation environments. Findings revealed that overall, PD was successful at shifting approximately two-thirds of the teachers’ EO towards knowledge generation. In addition, teachers’ change in EO score over three timepoints was significantly positively related to their implementation of knowledge generation practices. This research suggests that most early childhood teachers’ EO is open to change through PD and teaching experience, but the degree of this openness differs between individuals. The implications of these differences for PD and research are discussed.

Improvement of field fluorometry estimates of chlorophyll a concentration in a cyanobacteria‐rich eutrophic lake

AbstractInstrumented buoys are used to monitor water quality, yet there remains a need to evaluate whether in vivo fluorometric measures of chlorophyll a (Chl a) produce accurate estimates of phytoplankton abundance. Here, 6 years (2014–2019) of in vitro measurements of Chl a by spectrophotometry were compared with coeval estimates from buoy‐based fluorescence measurements in eutrophic Buffalo Pound Lake, Saskatchewan, Canada. Analysis revealed that fluorometric and in vitro estimates of Chl a differed both in terms of absolute concentration and patterns of relative change through time. Three models were developed to improve agreement between metrics of Chl a concentration, including two based on Chl a and phycocyanin (PC) fluorescence and one based on multiple linear regressions with measured environmental conditions. All models were examined in terms of two performance metrics; accuracy (lowest error) and reliability (% fit within confidence intervals). The model based on PC fluorescence was most accurate (error = 35%), whereas that using environmental factors was most reliable (89% within 3σ of mean). Models were also evaluated on their ability to produce spatial maps of Chl a using remotely sensed imagery. Here, newly developed models significantly improved system performance with a 30% decrease in Chl a errors and a twofold increase in the range of reconstructed Chl a values. Superiority of the PC model likely reflected high cyanobacterial abundance, as well as the excitation–emission wavelength configuration of fluorometers. Our findings suggest that a PC fluorometer, used alone or in combination with environmental measurements, performs better than a single‐excitation‐band Chl a fluorometer in estimating Chl a content in highly eutrophic waters.

Including Distorted Specimens in Allometric Studies: Linear Mixed Models Account for Deformation.

SynopsisAllometry—patterns of relative change in body parts—is a staple for examining how clades exhibit scaling patterns representative of evolutionary constraint on phenotype, or quantifying patterns of ontogenetic growth within a species. Reconstructing allometries from ontogenetic series is one of the few methods available to reconstruct growth in fossil specimens. However, many fossil specimens are deformed (twisted, flattened, and displaced bones) during fossilization, changing their original morphology in unpredictable and sometimes undecipherable ways. To mitigate against post burial changes, paleontologists typically remove clearly distorted measurements from analyses. However, this can potentially remove evidence of individual variation and limits the number of samples amenable to study, which can negatively impact allometric reconstructions. Ordinary least squares (OLS) regression and major axis regression are common methods for estimating allometry, but they assume constant levels of residual variation across specimens, which is unlikely to be true when including both distorted and undistorted specimens. Alternatively, a generalized linear mixed model (GLMM) can attribute additional variation in a model (e.g., fixed or random effects). We performed a simulation study based on an empirical analysis of the extinct cynodont, Exaeretodon argentinus, to test the efficacy of a GLMM on allometric data. We found that GLMMs estimate the allometry using a full dataset better than simply using only non-distorted data. We apply our approach on two empirical datasets, cranial measurements of actual specimens of E. argentinus (n = 16) and femoral measurements of the dinosaur Tawa hallae (n = 26). Taken together, our study suggests that a GLMM is better able to reconstruct patterns of allometry over an OLS in datasets comprised of extinct forms and should be standard protocol for anyone using distorted specimens.

Large Pelagic Fish Are Most Sensitive to Climate Change Despite Pelagification of Ocean Food Webs

Global climate change is expected to impact ocean ecosystems through increases in temperature, decreases in pH and oxygen, increased stratification, with subsequent declines in primary productivity. These impacts propagate through the food chain leading to amplified effects on secondary producers and higher trophic levels. Similarly, climate change may disproportionately affect different species, with impacts depending on their ecological niche. To investigate how global environmental change will alter fish assemblages and productivity, we used a spatially explicit mechanistic model of the three main fish functional types reflected in fisheries catches (FEISTY) coupled to an Earth system model (GFDL-ESM2M) to make projections out to 2100. We additionally explored the sensitivity of projections to uncertainties in widely used metabolic allometries and their temperature dependence. When integrated globally, the biomass and production of all types of fish decreased under a high emissions scenario (RCP 8.5) compared to mean contemporary conditions. Projections also revealed strong increases in the ratio of pelagic zooplankton production to benthic production, a dominant driver of the abundance of large pelagic fish vs. demersal fish under historical conditions. Increases in this ratio led to a “pelagification” of ecosystems exemplified by shifts from benthic-based food webs toward pelagic-based ones. The resulting pelagic systems, however, were dominated by forage fish, as large pelagic fish suffered from increasing metabolic demands in a warming ocean and from declines in zooplankton productivity that were amplified at higher trophic levels. Patterns of relative change between functional types were robust to uncertainty in metabolic allometries and temperature dependence, though projections of the large pelagic fish had the greatest uncertainty. The same accumulation of trophic impacts that underlies the amplification of productivity trends at higher trophic levels propagates to the projection spread, creating an acutely uncertain future for the ocean’s largest predatory fish.

Divergent long-term trends and interannual variation in ecosystem resource use efficiencies of a southern boreal old black spruce forest 1999-2017.

Long-term trends in ecosystem resource use efficiencies (RUEs) and their controlling factors are key pieces of information for understanding how an ecosystem responds to climate change. We used continuous eddy covariance and microclimate data over the period 1999-2017 from a 120-year-old black spruce stand in central Saskatchewan, Canada, to assess interannual variability, long-term trends, and key controlling factors of gross ecosystem production (GEP) and the RUEs of carbon (CUE=net primary production [NPP]/GEP), light (LUE=GEP/absorbed photosynthetic radiation [APAR]), and water (WUE=GEP/evapotranspiration [E]). At this site, annual GEP has shown an increasing trend over the 19years (p<0.01), which may be attributed to rising atmospheric CO2 concentration. Interannual variability in GEP, aside from its increasing trend, was most strongly related to spring temperatures. Associated with the significant increase in annual GEP were relatively small changes in NPP, APAR, and E, so that annual CUE showed a decreasing trend and annual LUE and WUE showed increasing trends over the 19years. The long-term trends in the RUEs were related to the increasing CO2 concentration. Further analysis of detrended RUEs showed that their interannual variation was impacted most strongly by air temperature. Two-factor linear models combining CO2 concentration and air temperature performed well (R2 ~0.60) in simulating annual RUEs. LUE and WUE were positively correlated both annually and seasonally, while LUE and CUE were mostly negatively correlated. Our results showed divergent long-term trends among CUE, LUE, and WUE and highlighted the need to account for the combined effects of climatic controls and the 'CO2 fertilization effect' on long-term variations in RUEs. Since most RUE-based models rely primarily on one resource limitation, the observed patterns of relative change among the three RUEs may have important implications for RUE-based modeling of C fluxes.

Genetic variation underlying local adaptation of diapause induction along a cline in a butterfly.

Diapause is a life history strategy allowing individuals to arrest development until favourable conditions return, and it is commonly induced by shortened day length that is latitude specific for local populations. Although understanding the evolutionary dynamics of a threshold trait like diapause induction provides insights into the adaptive process and adaptive potential of populations, the genetic mechanism of variation in photoperiodic induction of diapause is not well understood. Here, we investigate genetic variation underlying latitudinal variation in diapause induction and the selection dynamics acting upon it. Using a genomewide scan for divergent regions between two populations of the butterfly Pararge aegeria that differ strongly in their induction thresholds, we identified and investigated the patterns of variation in those regions. We then tested the association of these regions with diapause induction using between-population crosses, finding significant SNP associations in four genes present in two chromosomal regions, one with the gene period, and the other with the genes kinesin, carnitine O-acetyltransferase and timeless. Patterns of allele frequencies in these two regions in population samples along a latitudinal cline suggest strong selection against heterozygotes at two genes within these loci (period, timeless). Evidence for additional loci modifying the diapause decision was found in patterns of allelic change in relation to induction thresholds over the cline, as well as in backcross analyses. Taken together, population-specific adaptations of diapause induction appear to be due to a combination of alleles of larger and smaller effect size, consistent with an exponential distribution of effect sizes involved in local adaption.

Job polarization in European industries

AbstractJob polarization instead of pure upgrading is emerging in European industries. This article focuses on polarization of the employment structure and contributes empirical evidence to explain patterns of occupational change in relation to four major groups: managers, clerks, craft workers and manual workers. Building on the structural approach, the author aims to analyse employment dynamics at the sectoral level and shed light on job polarization trends in Europe. Job polarization clearly emerges, mainly in service sectors, and in some European countries it is leading to a rejection of the hypothesis of skill upgrading sustained by the skill‐biased technical change paradigm.

Contribution of lianas to community‐level canopy transpiration in a warm‐temperate forest

Summary Lianas (woody climbers) have a greater amount of leaves relative to basal area or standing biomass than trees, and very wide vessels that permit efficient water transport. These features suggest that lianas possibly consume proportionally more water through transpiration than trees. Despite their potential importance, researchers have made only limited attempts to evaluate effects of lianas on forest water dynamics. We conducted sap flow measurements for 1 year using a thermal dissipation method for four species each of lianas and trees in a liana‐rich, warm‐temperate forest in Japan and estimated the contribution of lianas to stand canopy transpiration. Based on a calibration measuring water uptake rates from cut‐stem ends, the actual sap flux (Fd) in liana stems was several times greater than those estimated from the original calibration provided for the method. In the field, lianas showed an average of 2–4 times greater Fd than trees throughout the year. Except for this difference, diurnal and seasonal patterns of relative changes of Fd were similar in both groups. The whole‐plant transpiration (Qt) of sample plants was exponentially related to basal diameter for both lianas and trees; Qt of lianas increased more steeply with basal diameter than that of trees. By extrapolating the relationships between Qt and basal diameter to the inventory data of the study plot, we estimated that lianas contributed 12·8% to the annual stand canopy transpiration while comprising 2·3% of stand basal area, which probably reflected the top‐heavy architecture of lianas. Our results indicate that the contribution of lianas to forest water dynamics may be several times greater than their contribution to forest basal area. This implies that a slight increase of liana abundance might have greater effects on water dynamics and, through competitions with trees for limited water, the carbon sequestration capacity of forests than expected from the increase in basal area. This study underlines the necessity of evaluating the relative importance of lianas to forest water dynamics in forests world‐wide. A lay summary is available for this article.

Changes in pitch height elicit both language-universal and language-dependent changes in neural representation of pitch in the brainstem and auditory cortex

Language experience shapes encoding of pitch-relevant information at both brainstem and cortical levels of processing. Pitch height is a salient dimension that orders pitch from low to high. Herein we investigate the effects of language experience (Chinese, English) in the brainstem and cortex on (i) neural responses to variations in pitch height, (ii) presence of asymmetry in cortical pitch representation, and (iii) patterns of relative changes in magnitude of pitch height between these two levels of brain structure. Stimuli were three nonspeech homologs of Mandarin Tone 2 varying in pitch height only. The frequency-following response (FFR) and the cortical pitch-specific response (CPR) were recorded concurrently. At the Fz-linked T7/T8 site, peak latency of Na, Pb, and Nb decreased with increasing pitch height for both groups. Peak-to-peak amplitude of Na–Pb and Pb–Nb increased with increasing pitch height across groups. A language-dependent effect was restricted to Na–Pb; the Chinese had larger amplitude than the English group. At temporal sites (T7/T8), the Chinese group had larger amplitude, as compared to English, across stimuli, but also limited to the Na–Pb component and right temporal site. In the brainstem, F0 magnitude decreased with increasing pitch height; Chinese had larger magnitude across stimuli. A comparison of CPR and FFR responses revealed distinct patterns of relative changes in magnitude common to both groups. CPR amplitude increased and FFR amplitude decreased with increasing pitch height. Experience-dependent effects on CPR components vary as a function of neural sensitivity to pitch height within a particular temporal window (Na–Pb). Differences between the auditory brainstem and cortex imply distinct neural mechanisms for pitch extraction at both levels of brain structure.

Abstract P210: Systolic Blood Pressure Trajectories From Childhood to Adulthood and Depression in Middle Age: The Bogalusa Heart Study

Introduction: Few studies have examined the long term patterns of blood pressure change in relation to depression in middle age. Methods: We examined data from the Bogalusa Heart Study, a long-term community-based observational study of a biracial cohort, with first measurements in childhood in 1973. Men and women (n=909) who completed the Center for Epidemiologic Studies Depression Scale (CES-D) in 2010 with at least two childhood and two adult SBP measurements were included. CES-D scores were categorized using established cut points (&lt;8, 8-15, &gt;15). Discrete mixture modeling was employed to identify trajectory groupings of (SBP), adjusted for race (time-independent) and body mass index (time-varying). The association between SBP trajectory and CES-D scores were determined using multivariable logistic regression adjusted for antihypertensive use, education, and physical activity in 2010. Results: Mean (±SD) age was 43.1±4.5 years, 57.9% were female, and 31.7% were Black. 27.7% of participants were current smokers in 2010. Mean (SD) BMI was 31.0 (7.7). We identified four SBP patterns: always low but slightly increasing (46.8%), low and modestly increasing (22.6%), healthy and stable (21.8%), and profoundly increasing (8.9%). Relative to the largest group, the multivariable adjusted odds ratio (OR) of higher CES-D categorization, i.e. more depressed, for the modestly increasing was 1.47 (95% CI, 1.01-2.15), for the stable, 0.96 (95% CI, 0.66-1.39), and for the profoundly increasing, 1.93 (95% CI, 0.66-1.39). Each additional year of education was associated with 33% decreased odds of higher CES-D categorization (OR=0.67, 95% CI 0.59-0.77). Conclusions: Trajectories of SBP from childhood through adulthood are associated with depression in middle age. Individuals with increasing SBP may benefit from depression screening in early adulthood.

Language-experience plasticity in neural representation of changes in pitch salience

Neural representation of pitch-relevant information at the brainstem and cortical levels of processing is influenced by language experience. A well-known attribute of pitch is its salience. Brainstem frequency following responses and cortical pitch specific responses, recorded concurrently, were elicited by a pitch salience continuum spanning weak to strong pitch of a dynamic, iterated rippled noise pitch contour—homolog of a Mandarin tone. Our aims were to assess how language experience (Chinese, English) affects i) enhancement of neural activity associated with pitch salience at brainstem and cortical levels, ii) the presence of asymmetry in cortical pitch representation, and iii) patterns of relative changes in magnitude along the pitch salience continuum. Peak latency (Fz: Na, Pb, and Nb) was shorter in the Chinese than the English group across the continuum. Peak-to-peak amplitude (Fz: Na–Pb, Pb–Nb) of the Chinese group grew larger with increasing pitch salience, but an experience-dependent advantage was limited to the Na–Pb component. At temporal sites (T7/T8), the larger amplitude of the Chinese group across the continuum was both limited to the Na–Pb component and the right temporal site. At the brainstem level, F0 magnitude gets larger as you increase pitch salience, and it too reveals Chinese superiority. A direct comparison of cortical and brainstem responses for the Chinese group reveals different patterns of relative changes in magnitude along the pitch salience continuum. Such differences may point to a transformation in pitch processing at the cortical level presumably mediated by local sensory and/or extrasensory influence overlaid on the brainstem output.

Sequential [F-18]FDG A mu PET whole-brain imaging of central vestibular compensation: a model of deafferentation-induced brain plasticity

Unilateral inner ear damage is followed by a rapid behavioural recovery due to central vestibular compensation. In this study, we utilized serial [F-18]Fluoro-deoxyglucose ([F-18]FDG)-A mu PET imaging in the rat to visualize changes in brain glucose metabolism during behavioural recovery after surgical and chemical unilateral labyrinthectomy, to determine the extent and time-course of the involvement of different brain regions in vestibular compensation and test previously described hypotheses of underlying mechanisms. Systematic patterns of relative changes of glucose metabolism (rCGM) were observed during vestibular compensation. A significant asymmetry of rCGM appeared in the vestibular nuclei, vestibulocerebellum, thalamus, multisensory vestibular cortex, hippocampus and amygdala in the acute phase of vestibular imbalance (4 h). This was followed by early vestibular compensation over 1-2 days where rCGM re-balanced between the vestibular nuclei, thalami and temporoparietal cortices and bilateral rCGM increase appeared in the hippocampus and amygdala. Subsequently over 2-7 days, rCGM increased in the ipsilesional spinal trigeminal nucleus and later (7-9 days) rCGM increased in the vestibulocerebellum bilaterally and the hypothalamus and persisted in the hippocampus. These systematic dynamic rCGM patterns during vestibular compensation, were confirmed in a second rat model of chemical unilateral labyrinthectomy by serial [F-18]FDG-A mu PET. These findings show that deafferentation-induced plasticity after unilateral labyrinthectomy involves early mechanisms of re-balancing predominantly in the brainstem vestibular nuclei but also in thalamo-cortical and limbic areas, and indicate the contribution of spinocerebellar sensory inputs and vestibulocerebellar adaptation at the later stages of behavioural recovery.

Which is the better proxy for paleo‐current strength: Sortable‐silt mean size () or sortable‐silt mean grain diameter (dSS)? A case study from the Nordic Seas

AbstractThe coarseness of the 10–63 μm terrigenous silt (i.e., sortable‐silt) fraction tends to vary independently of sediment supply in current‐sorted muds in the world's oceans, with coarser sediments representing relatively greater near‐bottom flow speeds. Traditionally, the coarseness of this size fraction is described using an index called sortable‐silt mean size ( ), which is an arithmetic average calculated from the differential volume or mass distribution of grains within the 10–63 μm terrigenous silt fraction, where the relative weights of the individual size bins become increasingly disproportionate, with respect to the actual number of grains within those size bins, toward the coarse end of the size range. This not only increases the absolute value of the apparent “mean size” within the 10–63 μm terrigenous silt fraction, but it may also affect the apparent pattern of relative changes in the coarseness of the sortable‐silt fraction along the core. In addition, it makes more prone to biases due to, for example, analytical errors. Here we present a detailed analysis of grain‐size distributions over three selected Holocene time intervals from two complementary sediment cores (JM97‐948/2A and MD95‐2011), extracted from the center of a high‐accumulation area along the flow path of the main branch of the Atlantic Inflow into the Nordic Seas and show that differential‐number‐based statistics, which likely better describes variations in the actual coarseness of the sortable‐silt fraction, may provide a more robust alternative to .

In search of lost time: the rise and fall of limits to growth in international sustainability policy

International environmental policy has failed to reverse climate change, resource depletion and the generalized decline of biodiversity and ecological life support systems. This paper traces economic roots of current environmental problems and examines the evolution of sustainability policy since the publication of Club of Rome’s report Limits to growth and the celebration of the first Earth summit in Stockholm in 1972 to the publication of UNEP’s Green economy report and the celebration of the last Earth summit in Rio 2012. Our emphasis is on the evolving framing of the relations between growth and the environment and the role of markets and states in the sustainability policy agenda. We review influential policy documents and Earth summit declarations since the early 1970s. Three major changes are identified in international sustainability discourse: (1) an analytical shift from a notion of growth versus the environment to a notion of growth for the environment, (2) a shift in focus from direct public regulation to market-based instruments, and (3) a shift from a political to a technocratic discourse. We note that attempts in sustainability policy to address the conflict between growth and the environment have pulled back severely since the 1970s and discuss the observed patterns of change in relation to changes in the balance of political and ideological forces. We conclude summarizing main insights from the review and discussing perspectives of the sustainability debate on growth and the environment.

Redistribution of forest biomass in an heterogeneous environment of subtropical Andes undergoing agriculture adjustment

Estimations of the carbon stored in the above-ground biomass are important from traditional, ecological and forestry to contemporary climate and land-use change perspectives. Carbon sequestration and storage is reduced by deforestation and degradation and enhanced by forest regrowth and expansion. Recent studies show that forests are experiencing redistribution at different scales. Regions with steep topographical gradients simultaneously experience these four processes, upon which the final carbon balance in forests depends, but large scale patterns of above-ground carbon changes within forests have generally been overlooked. We developed above-ground carbon maps for 2000 and 2012 in a heterogeneous environment of subtropical Andes to a) explore the patterns of change in relation to biophysical variables and forests types and b) calculate the relative contribution of within forest carbon change and of forest expansion/deforestation to total above-ground carbon balance. Above-ground carbon trends showed spatial variation: biomass losses occurred in dry forests at low-mid elevations, while gains were restricted to higher elevation forests. Within forest changes implied larger changes in carbon stocks (+361976 Mg C) and in an opposite direction than deforestation and reforestation (−56750.16 Mg C), and determined an overall stability in terms of above-ground carbon for the study period. These contrasting patterns of above-ground change may be representative of larger heterogeneous regions such as tropical and subtropical Andes, and highlight the need of explicitly accounting for within forests change in current carbon regional balances.

Sequential [(18)F]FDG µPET whole-brain imaging of central vestibular compensation: a model of deafferentation-induced brain plasticity.

Unilateral inner ear damage is followed by a rapid behavioural recovery due to central vestibular compensation. In this study, we utilized serial [(18)F]Fluoro-deoxyglucose ([(18)F]FDG)-µPET imaging in the rat to visualize changes in brain glucose metabolism during behavioural recovery after surgical and chemical unilateral labyrinthectomy, to determine the extent and time-course of the involvement of different brain regions in vestibular compensation and test previously described hypotheses of underlying mechanisms. Systematic patterns of relative changes of glucose metabolism (rCGM) were observed during vestibular compensation. A significant asymmetry of rCGM appeared in the vestibular nuclei, vestibulocerebellum, thalamus, multisensory vestibular cortex, hippocampus and amygdala in the acute phase of vestibular imbalance (4h). This was followed by early vestibular compensation over 1-2days where rCGM re-balanced between the vestibular nuclei, thalami and temporoparietal cortices and bilateral rCGM increase appeared in the hippocampus and amygdala. Subsequently over 2-7days, rCGM increased in the ipsilesional spinal trigeminal nucleus and later (7-9days) rCGM increased in the vestibulocerebellum bilaterally and the hypothalamus and persisted in the hippocampus. These systematic dynamic rCGM patterns during vestibular compensation, were confirmed in a second rat model of chemical unilateral labyrinthectomy by serial [(18)F]FDG-µPET. These findings show that deafferentation-induced plasticity after unilateral labyrinthectomy involves early mechanisms of re-balancing predominantly in the brainstem vestibular nuclei but also in thalamo-cortical and limbic areas, and indicate the contribution of spinocerebellar sensory inputs and vestibulocerebellar adaptation at the later stages of behavioural recovery.

Domains of Emergent Change: Making Sense of Emerging Patterns in the Midst of Change

This paper explores change leader sensemaking of emerging patterns in the midst of change. Drawing on complex adaptive systems theory, we argue that change leaders are neither prime movers, nor passive recipients of emergent organizational change. They actively co-create emerging macro-level patterns through everything they say and do as they interact with other organizational members. How change leaders make sense about emerging macro-level patterns plays an important role in emergence. Yet, we know little about the content or challenges of that sensemaking from the perspective of change leaders. Using a real- time, multi-level study of an organization and its change leaders in the midst of change, we followed the emerging patterns of change over a particularly dynamic 2-year period, and found that making sense of them is challenging work for change leaders. Although emergent change outcomes cannot be predicted, our identification of ‘domains of emergent organizational change’ (the ‘patterning of events’, ‘changing patterns of relations’, ‘changing patterns of attention’), and a multi-level typology for their classification, may help scholars and change leaders to theoretically anticipate and make sense of emerging organizational patterns.

Evaluation of diel patterns of relative changes in cell turgor of tomato plants using leaf patch clamp pressure probes

Relative changes in cell turgor of leaves of well-watered tomato plants were evaluated using the leaf patch clamp pressure probe (LPCP) under dynamic greenhouse climate conditions. LPCP changes, a measure for relative changes in cell turgor, were monitored at three different heights of transpiring and non-transpiring leaves of tomato plants on sunny and cloudy days simultaneously with whole plant water uptake. Clear diel patterns were observed for relative changes of cell turgor of both transpiring and non-transpiring leaves, which were stronger on sunny days than on cloudy days. A clear effect of canopy height was also observed. Non-transpiring leaves showed relative changes in cell turgor that closely followed plant water uptake throughout the day. However, in the afternoon the relative changes of cell turgor of the transpiring leaves displayed a delayed response in comparison to plant water uptake. Subsequent recovery of cell turgor loss of transpiring leaves during the following night appeared insufficient, as the pre-dawn turgescent state similar to the previous night was not attained.

Early to Middle Pleistocene dynamics of plant and mammal communities in South West Europe

For the first time, the general trends of large mammal fauna changes in SW Europe during the Middle Pleistocene Revolution (MPR) have been compared with the coeval vegetation dynamics. Both vegetation and animal communities significantly varied during the MPR, but with different regional timings and modes. A number of new and last appearances are found in mammals, so that there is no substantial loss of richness. By contrast, since at least 1.5Ma no new tree genera are recorded in SW Europe, while many taxa progressively disappeared and their range was occupied by taxa already present in the region. Compared to animals, plant communities show a remarkable persistence, so that in many cases many modern tree populations may be direct descendants of the Early Pleistocene ones in the same region. No such case of long-term persistence since at least the late Early Pleistocene is observed in the faunal record, which underwent a complex history of species turnovers, mainly related to dispersal events, and competitive exclusions, but also originations of endemic species. A comparison among regional trends in SW Europe shows a marked increase in regionalization during the MPR in the faunal record, while only modest differences are found in the vegetation dynamics of N Spain, S France and central Italy. On the whole, disentangling the relationships between vegetation and mammals at time scales of 105 years is a very complex task, due to different patterns of change in relation to climate oscillations.