Context Of Environmental Change Research Articles

Hot debate: Identifying heat treatment in Australian archaeology using science and modern indigenous knowledge

The deliberate heat treatment of lithic material for stone tools is a critical and hotly debated subject in human evolution and archaeology, representing a major technological innovation. This engineering of material has proven hard to demonstrate with archaeological data, although experimental data back early records from southern Africa. There is scant evidence of heat treatment from records representing early modern human migrations out of Africa and along the migration routes through Sunda to Sahul. The long cultural sequences found in Australian archaeology, have rarely been assessed for heat treatment, although it was practised in recent times by Indigenous peoples. Using modern Indigenous knowledge and a comprehensive review of the latest heat treatment identification methods, we assess a Pleistocene to Holocene record spanning some 47,000 years, for signals of deliberate heat treatment. We find unambiguous evidence for heat treatment to occur only in the mid to late Holocene, corresponding to a time of significant change. We discuss these findings concerning stone tool technology as an adaptive response to changing environmental, economic and social contexts. Our unique approach offers global relevance to the study of deliberate heat treatment in prehistory and engages with global debates on technological organization theory.

Wild Meat in Changing Times

Across the Global South, wildlife is harvested for food and livelihoods and for cultural and medicinal purposes, yet the dynamics of the wild meat sector are changing as remote areas become more accessible, more people are living in urban areas, and the world is becoming increasingly connected. The research articles in this special issue explore the contemporary use of wild meat in the lives and livelihoods of people across a rural-urban gradient, provide examples of how use may be evolving in relation to the changing social, political, economic, cultural, and environmental contexts, and what this means for sustainable wildlife management and biodiversity conservation. Urbanization, social change, and cultural dynamics contribute to the diversity of, and motivation for, wild meat uses, while human population growth and the changing state of the natural environment can ultimately influence sustainability. Given the diversity of wild meat uses across social-ecological contexts, and the potential for inequitable management decisions, incorporating social justice in wild meat management will ensure human-wellbeing while curbing biodiversity loss.

Comments on ‘U-Pb dated flowstones restrict South African early hominin record to dry climate phases’ (Pickering et al. Nature 2018;565:226–229)

Pickering et al. (Nature 2018;565:226–229) utilised calcium carbonate flowstone deposits (i.e. speleothems) from eight Pliocene and Pleistocene South African Cradle of Humankind cave sites to propose that biases were created within the fossil record due to absent clastic sedimentation phases during wet periods, when caves were closed and only speleothems accumulated. Such a scenario has significant implications for our understanding of variability in hominin mobility, resource exploitation, functional repertoires and interactions with competitors in changing environmental and ecological contexts. We find considerable issues with the article. First, Pickering et al.’s contribution omits crucial fossil evidence from various stratigraphic units of the Sterkfontein Caves that indicates conditions were not always arid when the caves were open and sediments were deposited. Second, Pickering et al.’s proposal that clastic and speleothemic deposits (including faunal and floral material) form mutually exclusively is an overly simplified, binary depositional (and in this case environmental) framework that demonstrates an inherent bias in the sampling of cave deposits for dating. This creates the impression that either speleothems or clastic sediments are deposited and does not take into account the full spectrum of sedimentary complexity in karst caves. Third, closure of the caves across the Cradle of Humankind landscape during wet periods is not substantiated geomorphologically or speleologically; identification of the responsible process is critical to the proposed infilling scenario.
 Significance:
 
 We propose that Pickering et al.’s interpretation of the environmental context of the South African early hominin record is problematic in that it omits crucial faunal and floral fossil evidence associating hominins with non-arid climates, is geomorphologically unsupported, and perpetuates biases against temporally and climatically representative clastic sediments due to challenges related to their dating.

Multiple independent chromosomal fusions accompanied the radiation of the Antarctic teleost genus Trematomus (Notothenioidei:Nototheniidae)

BackgroundChromosomal rearrangements are thought to be an important driving force underlying lineage diversification, but their link to speciation continues to be debated. Antarctic teleost fish of the family Nototheniidae (Notothenioidei) diversified in a changing environmental context, which led to ecological, morphological, and genetic differentiation among populations. In addition, extensive chromosomal repatterning accompanied species divergence in several clades. The most striking karyotypic changes involved the recent species radiation (about 10 My) of the genus Trematomus, with chromosomal pair numbers ranging between 29 and 12. These dramatic reductions in chromosome number resulted mostly from large-scale chromosome fusions. Multiple centric and/or tandem fusions have been hypothesized in at least seven of the twelve recognized Trematomus species. To reconstruct their evolutionary history, we employed comparative cytogenomics (BAC-FISH and chromosome painting) to reveal patterns of interspecific chromosomal orthologies across several notothenioid clades.ResultsWe defined orthologous chromosomal segments of reference, termed Structural Units (SUs). SUs were identified in a total of 18 notothenioid species. We demonstrated for the first time that SUs were strongly conserved across every specimen examined, with chromosomal syntenies highlighting a paucity of intrachromosomal macro-rearrangements. Multiple independent fusions of these SUs were inferred in the Trematomus species, in contrast to the shared SU fusions in species of the sister lineage Notothenia.ConclusionsThe SU segments were defined units of chromosomal rearrangement in the entire family Nototheiidae, which diverged from the other notothenioid families 20 My ago. Some of the identified chromosomal syntenies within the SUs were even conserved in their closest relatives, the family Eleginopsidae. Comparing the timing of acquisition of the fusions in the closely related genera Notothenia and Trematomus of the nototheniid species family, we conclude that they exhibit distinct chromosomal evolutionary histories, which may be relevant to different speciation scenarios.

Situation Analytics and Model-based User Interface Development: A Synergetic Approach for Building Runtime-Adaptive Business Applications

Situation analytics can be used to recognize the changing behavior, emotional state, cognitive load and environmental context of a user during complex task processing. This article discusses the SitAdapt 2.0 architecture that combines a situation analytics platform with pattern- and model-based user interface construction tools in order to build runtime-adaptive interactive business applications with enhanced user experience and task-accomplishment characteristics. The article focuses on the software components and tools for observing and tracking the user, data types for modeling situations, recognizing situations, and modeling structural changes and actions for generating the dynamic adaptations. The situation recognition capabilities and adaptive functionality of the system are demonstrated for web-applications for long-distance travel booking and a beauty products web-portal.

Applying Brantingham's neutral model of stone raw material procurement to the Pinnacle Point Middle Stone Age record, Western Cape, South Africa

The Palaeo-Agulhas Plain (PAP), when exposed, presented Middle Stone Age (MSA) foragers at Pinnacle Point (PP) on the South Coast of South Africa with new sources of raw materials to make stone tools. Sea-level fluctuations and the changing size of the Paleo-Agulhas Plain throughout the Pleistocene PP record ∼165 ka to 50 ka would have altered the availability of different resources, thus potentially forcing new raw material procurement strategies. The relative frequencies of raw material throughout the PP sequence shows that frequencies of raw material types did change, especially after 90 ka. What caused these changing frequencies is debated and centers on whether targeted procurement of specific raw materials was the cause, or if simple raw material availability and abundance due to the changing environmental context in conjunction with opportunistic procurement drove such shifts. The application of a neutral model of stone raw material procurement presented here evaluates whether random walk in the region surrounding the PP site during different coastline configurations (Marine Isotope Stage 6, 5, and 4) explains the observed shifts in raw material usage. Put differently, did opportunistic acquisition of raw materials during random walk in these different environments cause the observed raw material pattern? Model simulations and a sensitivity analysis provide no convincing evidence that observed raw material frequencies at PP resulted from opportunistic acquisition during random walk.

Consistency in boldness expression varies with ecological context in a jumping spider

AbstractAnimals can adjust their behaviours depending on ecological context (i.e., behavioural plasticity), and an individual's response to a given context may also vary from occasion to occasion (intra‐individual variability). Recognizing the roles of both behavioural plasticity and intra‐individual variability is important in understanding how behavioural diversity is maintained within populations. However, how the ecological context itself influences the individual behavioural response and intra‐individual variability (e.g., how variable an individual is in their behavioural expression) remains largely unexplored. Here, we examine boldness expression (the duration of startle response) in a specialised spider‐eating jumping spider, Portia labiata, across three contexts following a mild disturbance: presence of a conspecific intruder (most dangerous), environmental change but no conspecific intruder, and no conspecific intruder or environmental change (safest). We found that context does not significantly influence the average boldness expression at the population level. However, each individual responded to each context differently, and the repeatability of boldness expression—the proportion of behavioural variation attributable to the between ‐individual level—is context‐dependent. We also found that in the presence of a conspecific intruder, spiders behave less predictably than in the environmental change context, but not differently from the safest context. These findings may suggest that the presence of conspecifics influences behavioural consistency in individuals, but that this may occur without influencing the population average behaviour.

A nonnative habitat-former mitigates native habitat loss for endemic reef fishes.

Animals that select the best available habitats are most likely to succeed in degraded environments, but ecological change can create evolutionarily unfamiliar habitats that may be under- or over-utilized by native fauna. In temperate coastal waters, eutrophication and grazing have driven a global decline in native seaweeds and facilitated the establishment of nonnative seaweeds that provide novel macrophyte habitat. We tested whether a nonnative kelp canopy (wakame Undaria pinnatifida) functions as a viable habitat or ecological trap for several endemic reef fishes on urchin-grazed reefs in southern Australia. We assessed the willingness of fish to utilize native vs. wakame kelp canopy via a laboratory habitat choice experiment and by recording natural recruitment to specially constructed boulder reefs with manipulated kelp canopy. We also compared fish communities on natural reefs using a before-after-control-impact survey of wakame patches, and to assess the quality of wakame habitat for resident fish, compared fitness metrics for fish collected from habitats with native vs. wakame kelp canopy. Endemic fishes did not distinguish between the native or wakame canopy but preferred both to barren reef habitats. On urchin-grazed natural reefs, fish occurred in higher abundance and diversity where seasonal wakame canopy was present. Fitness metrics in fish collected from wakame patches were comparable to those in fish from adjacent native kelp patches. These findings indicate that the nonnative canopy provides a viable habitat for endemic fish and may play a role in sustaining native fauna populations in this degraded ecosystem. More broadly, we recommend that managers consider the role of nonnative habitats within the context of environmental change, as endemic fauna may benefit from nonnative habitat-formers in areas where their native counterparts cannot persist.

Towards Dynamically Reconfigurable IoT Camera Virtualization for Video Analytics Edge Cloud Services

Video analytics edge computing exploiting IoT cameras has gained high attention. Running such tasks on the network edge is very challenging since video and image processing are bandwidth-hungry and computationally intensive. IoT cameras are heavily dependent on environmental factors such as the brightness of the view. In this paper, we propose an edge IoT camera virtualization architecture that enables an IoT camera to accommodate multiple application operation semantics and dynamically adjust its configuration to preserve them in the presence of environment context changes. For this, we develop an ontology-based application description model, a virtualization architecture with the container technology, and a context-aware dynamic reconfiguration scheme.

Maintenance Objective Selection Framework Applicable to Designing and Improving Maintenance Programs

Maintenance optimization is applied by organizations to develop robust maintenance programs while attempting to establish a trade-off between competing maintenance requirements and resources. For this reason, maintenance decisions derived from maintenance optimization models are adversely affected, if (a) the maintenance objective(s) applied as input to the optimization models is not dynamically reviewed as the organizations environment context changes, and (b) there is continued use of historical maintenance objectives, oftentimes the practice for organizations lacking a framework for selecting maintenance objectives (MO’s). To address this, an interactive maintenance objective selection framework for stakeholders that aligns with and considers changes in the organization’s business, operational, and technical context, where dynamic maintenance objectives are selected and prioritized for application in real-life maintenance optimization models is proposed. The framework uses an analytic network process (ANP) based methodology, for selecting the relevant MO’s in view of competing dynamic criteria, for instance, employing remanufactured spares to optimize availability and maintenance cost. The applicability of the framework is demonstrated in case studies of companies operating in diverse industries like aviation and manufacturing in Africa. The study highlights the effects of dependencies between competing maintenance objectives, where the dependencies invariably influence how organizations prioritize MO’s to use for maintenance optimization programs. The additional value of the proposed framework lies in assisting organizations select maintenance objectives applicable to the organization while considering competing objectives and evolving business context.

Flexibility, variability and constraint in energy management patterns across vertebrate taxa revealed by long‐term heart rate measurements

Abstract Animals are expected to be judicious in the use of the energy they gain due to the costs and limits associated with its intake. The management of energy expenditure (EE) exhibited by animals has previously been considered in terms of three patterns: the constrained, independent and performance patterns of energy management. These patterns can be interpreted by regressing daily EE against maintenance EE measured over extended periods. From the multiple studies on this topic, there is equivocal evidence about the existence of universal patterns in certain aspects of energy management. The implicit assumption that animals exhibit specifically one of three discrete energy management patterns, and without variation, seems simplistic. We suggest that animals can exhibit gradations of different energy management patterns and that the exact pattern will fluctuate as their environmental context changes. To investigate these ideas, and for possible large‐scale patterns in energy management, we analysed long‐term heart rate data—a strong proxy for EE—across and within individuals in 16 species of birds, mammals and fish. Our analyses of 292 individuals representing 46,539 observation‐days suggest that vertebrates typically exhibit predominantly the independent or performance energy patterns at the across‐individual level, and that the pattern does not associate with taxonomic group. Within individuals, however, animals generally exhibit some degree of energy constraint. Together, these findings indicate that across diverse species, some individuals supply more energy to all aspects of their life than do others, however all individuals must trade‐off deployment of their available energy between competing functions. This demonstrates that within‐individual analyses are essential for the interpretation of energy management patterns. We also found that species do not necessarily exhibit a fixed energy management pattern but rather temporal variation in their energy management over the year. Animals’ energy management exhibited stronger energy constraint during periods of higher EE, which typically coincided with clear and key life cycle events such as reproduction, suggesting an adaptive plasticity to respond to fluctuating energy demands. A plain language summary is available for this article.

Context and Change: A Longitudinal Analysis of Attitudes about Immigrants in Adolescence

Research has explored many different relationships between contextual influences, such as levels of immigration or economic condition, and attitudes about immigrants, with mixed results. These have largely been international comparative studies using cross-sectional data, therefore they have been unable to make claims about changes in environmental context translating to changes in attitudes of respondents. Furthermore, the previous literature has almost exclusively tested these relationships using data from adults, despite research showing that attitudes are most subject to change during adolescence. This study addresses these issues by using a longitudinal data set of repeated measures of 2,328 German adolescents (about 14–18 years old) over four response waves (2010–2014). Using a multilevel analysis, results show that contextual changes, including the percentage of foreign-born people and unemployment rates within respondents’ states, correspond to changes in attitudes toward immigrants consistent with group threat theory. These results were stable even when controlling individual-level factors.

Percepciones del cambio climático en la Isla de Chiloé: Desafíos para la gobernanza local

Chiloe is an island in the south of Chile that presents multiple issues associated with the nonsustainableuse of natural resources and high levels of poverty and inequality. Using qualitative methods,this article explores how keys stakeholders are perceiving and responding to climate change in such acomplex social and environmental context. Results show this phenomenon is perceived as an emergentissue, whose social and environmental impacts are already happening. Generally individual responsesare implemented, prevailing power asymmetries and competition over cooperation, coordination andexchange of experiences between stakeholders. A climate change governance system for the islandshould deal not only with institutional barriers but also promote social and cultural transformations.

Area-specific Modulation of Functional Cortical Activity During Block-based and Trial-based Proactive Inhibition

Animals can suppress their behavioral response in advance according to changes in environmental context (proactive inhibition: delaying the start of response), a process in which several cortical areas may participate. However, it remains unclear how this process is adaptively regulated according to contextual changes on different timescales. To address the issue, we used an improved stop-signal task paradigm to behaviorally and electrophysiologically characterize the temporal aspect of proactive inhibition in head-fixed rats. In the task, they must respond to a go cue as quickly as possible (go trial), but did not have to respond if a stop cue followed the go cue (stop trial). The task alternated between a block of only go trials (G-block) and a block of go-and-stop trials (GS-block). We observed block-based and trial-based proactive inhibition (emerging in GS-block and after stop trial, respectively) by behaviorally evaluating the delay in reaction time in correct go trials depending on contextual changes on different timescales. We electrophysiologically analyzed task-related neuronal activity in the primary and secondary motor, posterior parietal, and orbitofrontal cortices (M1, M2, PPC, and OFC, respectively). Under block-based proactive inhibition, spike activity of cue-preferring OFC neurons was attenuated continuously, while M1 and M2 activity was enhanced during motor preparation. Subsequently, M1 activity was attenuated during motor decision/execution. Under trial-based proactive inhibition, the OFC activity was continuously enhanced, and PPC and M1 activity was also enhanced shortly during motor decision/execution. These results suggest that different cortical mechanisms underlie the two types of proactive inhibition in rodents.

CEO adaptive capacity and performance over time

The dynamic managerial capabilities framework posits that CEOs differ in their ability to deal with a changing environmental context. However, little is known empirically about what enables some but not other CEOs to maintain fit with an evolving environmental context over their tenure. Using a large data sample of 16805 CEO-year observations encompassing 3,482 CEOs in 2,094 firms, we find evidence that CEOs differ in their capacity to respond to changes in their firms’ environment, that this adaptive capacity is rooted in the nature of their prior experience, and it is evident in their performance trajectories over time. We discuss the implications of our findings for the dynamic managerial capabilities literature and renewal at the upper-echelons in practice.

Association between internal migration and epidemic dynamics: an analysis of cause-specific mortality in Kenya and South Africa using health and demographic surveillance data

BackgroundMany low- and middle-income countries are facing a double burden of disease with persisting high levels of infectious disease, and an increasing prevalence of non-communicable disease (NCD). Within these settings, complex processes and transitions concerning health and population are underway, altering population dynamics and patterns of disease. Understanding the mechanisms through which changing socioeconomic and environmental contexts may influence health is central to developing appropriate public health policy. Migration, which involves a change in environment and health exposure, is one such mechanism.MethodsThis study uses Competing Risk Models to examine the relationship between internal migration and premature mortality from AIDS/TB and NCDs. The analysis employs 9 to 14 years of longitudinal data from four Health and Demographic Surveillance Systems (HDSS) of the INDEPTH Network located in Kenya and South Africa (populations ranging from 71 to 223 thousand). The study tests whether the mortality of migrants converges to that of non-migrants over the period of observation, controlling for age, sex and education level.ResultsIn all four HDSS, AIDS/TB has a strong influence on overall deaths. However, in all sites the probability of premature death (45q15) due to AIDS/TB is declining in recent periods, having exceeded 0.39 in the South African sites and 0.18 in the Kenyan sites in earlier years. In general, the migration effect presents similar patterns in relation to both AIDS/TB and NCD mortality, and shows a migrant mortality disadvantage with no convergence between migrants and non-migrants over the period of observation. Return migrants to the Agincourt HDSS (South Africa) are on average four times more likely to die of AIDS/TB or NCDs than are non-migrants. In the Africa Health Research Institute (South Africa) female return migrants have approximately twice the risk of dying from AIDS/TB from the year 2004 onwards, while there is a divergence to higher AIDS/TB mortality risk amongst female migrants to the Nairobi HDSS from 2010.ConclusionResults suggest that structural socioeconomic issues, rather than epidemic dynamics are likely to be associated with differences in mortality risk by migrant status. Interventions aimed at improving recent migrant’s access to treatment may mitigate risk.

Māori oral traditions record and convey indigenous knowledge of marine and freshwater resources

ABSTRACT Whakataukī are part of a strongly developed Māori oral tradition that conveys critical information about aspects of life, society and tribal memory, including ecological knowledge. Such codified knowledge depends on language use and structure as a key mechanism for cultural transmission. Additionally, many meanings may not be apparent without knowing the historical, cultural and linguistic context from which the whakataukī originated. We examined a primary dataset of c. 3500 versions of whakataukī, drawn from collections published after European arrival c. 200 years ago, to determine how marine and freshwater principles, practices and knowledge bases have developed in response to changing environmental and societal contexts in Aotearoa. We present information on marine and freshwater resources contained in whakataukī to shed light on the connections between humans and their environment that transcend prosaic uses and enlighten deeper social and behavioural engagement with the surrounding environment. Understanding past engagement can help shape future marine and freshwater relationships in Aotearoa.

The Qualitative Stage of Building Bayesian Belief Networks in a Focus Group Setting: Decision-Making under Uncertainty among Vietnamese Rice Farmers

An innovative mixed-methods approach to exploratory focus group design is presented using a case study conducted with smallholder rice farmers in Vietnam. Understanding human decision-making under the uncertainties of a complex and changing social and environmental context requires a flexible yet structured and theoretically grounded approach. Using Bayesian belief networks as the architecture of our model allows the study to incorporate both qualitative and quantitative data, the former gathered at this stage in a participatory focus group setting and the latter to be collected in a subsequent survey. This framework further lends itself well to incorporating systematic behavioral approaches to decision-making analysis using Ajzen’s theory of planned behavior framework, a symbiosis that remains underexplored in the literature. The visual nature of the networks makes them easily accessible to participants, and the proposed technical solutions to field implementation are flexible, inexpensive, and shown in practice to mitigate issues of co-moderating discussion across language barriers. The tools and methods described are transparent, reproducible in comparative contexts, and transferable to a range of research topics and questions.

The Effect of Practice Schedule on Context-Dependent Learning

ABSTRACTIt is well established that random practice compared to blocked practice enhances motor learning. Additionally, while information in the environment may be incidental, learning is also enhanced when an individual performs a task within the same environmental context in which the task was originally practiced. This study aimed to disentangle the effects of practice schedule and incidental/environmental context on motor learning. Participants practiced three finger sequences under either a random or blocked practice schedule. Each sequence was associated with specific incidental context (i.e., color and location on the computer screen) during practice. The participants were tested under the conditions when the sequence-context associations remained the same or were changed from that of practice. When the sequence-context association was changed, the participants who practiced under blocked schedule demonstrated greater performance decrement than those who practiced under random schedule. The findings suggested that those participants who practiced under random schedule were more resistant to the change of environmental context.

Computational model for behavior shaping as an adaptive health intervention strategy.

Adaptive behavioral interventions that automatically adjust in real-time to participants' changing behavior, environmental contexts, and individual history are becoming more feasible as the use of real-time sensing technology expands. This development is expected to improve shortcomings associated with traditional behavioral interventions, such as the reliance on imprecise intervention procedures and limited/short-lived effects. JITAI adaptation strategies often lack a theoretical foundation. Increasing the theoretical fidelity of a trial has been shown to increase effectiveness. This research explores the use of shaping, a well-known process from behavioral theory for engendering or maintaining a target behavior, as a JITAI adaptation strategy. A computational model of behavior dynamics and operant conditioning was modified to incorporate the construct of behavior shaping by adding the ability to vary, over time, the range of behaviors that were reinforced when emitted. Digital experiments were performed with this updated model for a range of parameters in order to identify the behavior shaping features that optimally generated target behavior. Narrowing the range of reinforced behaviors continuously in time led to better outcomes compared with a discrete narrowing of the reinforcement window. Rapid narrowing followed by more moderate decreases in window size was more effective in generating target behavior than the inverse scenario. The computational shaping model represents an effective tool for investigating JITAI adaptation strategies. Model parameters must now be translated from the digital domain to real-world experiments so that model findings can be validated.