Research into the causes of civilian abuse during civil conflict has increased significantly in recent years, yet the mechanisms responsible for changes in actors' tactics remain poorly understood. I ...investigate how the outcomes of discrete conflict interactions influence subsequent patterns of rebel violence against civilians. Two competing logics suggest opposite influences of material loss on violence. A stylized model of rebel-civilian bargaining illustrates how acute resource demands resulting from recent severe conflict losses may incentivize insurgent violence and predation. I also identify several factors that might condition this relationship. I evaluate hypotheses based on these expectations by first analyzing the behaviors of the Lord's Resistance Army using subnational conflict data and then analyzing a cross-sectional sample of post–Cold War African insurgencies. Results from both the micro- and macrolevel analyses suggest that rising battlefield costs incentivize attacks on civilians in the period immediately following the accrual of losses. However, group-level factors such as effective control over territory and the sources of rebel financing condition this relationship. The findings suggest potential benefits from examining the interaction of strategic conditions and more static organizational characteristics in explaining temporal and geographic variation in rebel violence.
In the environment, bacteria live in complex multispecies communities. These communities span in scale from small, multicellular aggregates to billions or trillions of cells within the ...gastrointestinal tract of animals. The dynamics of bacterial communities are determined by pairwise interactions that occur between different species in the community. Though interactions occur between a few cells at a time, the outcomes of these interchanges have ramifications that ripple through many orders of magnitude, and ultimately affect the macroscopic world including the health of host organisms. In this review we cover how bacterial competition influences the structures of bacterial communities. We also emphasize methods and insights garnered from culture-dependent pairwise interaction studies, metagenomic analyses, and modeling experiments. Finally, we argue that the integration of multiple approaches will be instrumental to future understanding of the underlying dynamics of bacterial communities.
Tired and stressed: Examining the need for sleep Hill, Vanessa M.; O'Connor, Reed M.; Shirasu-Hiza, Mimi
The European journal of neuroscience,
January 2020, Letnik:
51, Številka:
1
Journal Article
Recenzirano
Odprti dostop
A key feature of circadian rhythms is the sleep/wake cycle. Sleep causes reduced responsiveness to the environment, which puts animals in a particularly vulnerable state; yet sleep has been conserved ...throughout evolution, indicating that it fulfils a vital purpose. A core function of sleep across species has not been identified, but substantial advances in sleep research have been made in recent years using the genetically tractable model organism, Drosophila melanogaster. This review describes the universality of sleep, the regulation of sleep, and current theories on the function of sleep, highlighting a historical and often overlooked theory called the Free Radical Flux Theory of Sleep. Additionally, we summarize our recent work with short‐sleeping Drosophila mutants and other genetic and pharmacological tools for manipulating sleep which supports an antioxidant theory of sleep and demonstrates a bi‐directional relationship between sleep and oxidative stress.
The state of the art for optimal water reservoir operations is rapidly evolving, driven by emerging societal challenges. Changing values for balancing environmental resources, multisectoral human ...system pressures, and more frequent climate extremes are increasing the complexity of operational decision making. Today, reservoir operations benefit from technological advances, including improved monitoring and forecasting systems as well as increasing computational power. Past research in this area has largely focused on improving solution algorithms within the limits of the available computational power, using simplified problem formulations that can misrepresent important systemic complexities and intersectoral interactions. In this study, we review the recent literature focusing on how the operation design problem is formulated, rather than solved, to address existing challenges and take advantage of new opportunities. This paper contributes a comprehensive classification of over 300 studies published over the last years into distinctive categories depending on the adopted problem formulation, which clarifies consolidated methodological approaches and emerging trends. Our analysis also suggests that control policy design methods may benefit from broadening the types of information that is used to condition operational decisions, and from using emulation modeling to identify low‐order, computationally efficient surrogate models capturing realistic representations of river basin systems' complexity in order to isolate key decision‐relevant processes. These advances in reservoir operations hold significant promise for better addressing the challenges of conflicting human pressures and a changing world, which is particularly important, given the renewed interest in dam construction globally.
Key Points
We review the evolution of water reservoir operation studies driven by emerging societal challenges
Simulation‐based control methods facilitate realistic problem formulations that are able to handle system uncertainties
Research opportunities remain to combine policy design with more information sources and emulation modeling
Post-translational modifications of p53 are critical in modulating its tumor suppressive functions. Ubiquitylation, for example, plays a major role in dictating p53 stability, subcellular ...localization and transcriptional vs. non-transcriptional activities. Less is known about p53 acetylation. It has been shown to govern p53 transcriptional activity, selection of growth inhibitory vs. apoptotic gene targets, and biological outcomes in response to diverse cellular insults. Yet recent in vivo evidence from mouse models questions the importance of p53 acetylation (at least at certain sites) as well as canonical p53 functions (cell cycle arrest, senescence and apoptosis) to tumor suppression. This review discusses the cumulative findings regarding p53 acetylation, with a focus on the acetyltransferases that modify p53 and the mechanisms regulating their activity. We also evaluate what is known regarding the influence of other post-translational modifications of p53 on its acetylation, and conclude with the current outlook on how p53 acetylation affects tumor suppression. Due to redundancies in p53 control and growing understanding that individual modifications largely fine-tune p53 activity rather than switch it on or off, many questions still remain about the physiological importance of p53 acetylation to its role in preventing cancer.
The sustainable use of natural resources is an important global challenge, and improved metal sustainability is a crucial goal for the 21st century in order to conserve the supply of critical metals ...and mitigate the environmental and health issues resulting from unrecovered metals. Metal Sustainability: Global Challenges, Consequences and Prospects discusses important topics and challenges associated with sustainability in metal life cycles, from mining ore to beneficiation processes, to product manufacture, to recovery from end-of-life materials, to environmental and health concerns resulting from generated waste. The broad perspective presented highlights the global interdependence of the many stages of metal life cycles. Economic issues are emphasized and relevant environmental, health, political, industrial and societal issues are discussed. The importance of applying green chemistry principles to metal sustainability is emphasized. Topics covered include: •Recycling and sustainable utilization of precious and specialty metals •Formal and informal recycling from electronic and other high-tech wastes •Global management of electronic wastes •Metal reuse and recycling in developing countries •Effects of toxic and other metal releases on the environment and human health •Effect on bacteria of toxic metal release •Selective recovery of platinum group metals and rare earth metals •Metal sustainability from a manufacturing perspective •Economic perspectives on sustainability, mineral development, and metal life cycles •Closing the Loop – Minerals Industry Issues The aim of this book is to improve awareness of the increasingly important role metals play in our high-tech society, the need to conserve our metal supply throughout the metal life cycle, the importance of improved metal recycling, and the effects that unhindered metal loss can have on the environment and on human health.
Humanitarian assistance is intended to ameliorate the human costs of war by providing relief to vulnerable populations. Yet the introduction of aid resources into conflict zones may influence ...subsequent violence patterns and expose intended recipients to new risks. Here we investigate the potential negative externalities associated with humanitarian aid. We argue that aid can create incentives for armed actors to intentionally target civilians for violence. Aid encourages rebel violence by providing opportunities for looting and presenting challenges to rebel authority. It potentially encourages state violence where it augments rebel capabilities or provides rebels a resource base. We evaluate both arguments using spatially disaggregated data on aid and conflict violence for a sample of nearly two dozen post–Cold War African countries. The results of multiple statistical analyses provide strong support for the argument that humanitarian aid is associated with increased rebel violence but less support for the relationship between aid and state violence.
•New definitions of research impact and impact evaluation are proposed.•A typology of research impact evaluation designs is provided.•A methodological framework is proposed to guide evaluations of ...the significance and reach of impact that can be attributed to research.•These enable evaluation design and methods to be selected to evidence the impact of research from any discipline.
Interest in impact evaluation has grown rapidly as research funders increasingly demand evidence that their investments lead to public benefits.
This paper analyses literature to provide a new definition of research impact and impact evaluation, develops a typology of research impact evaluation designs, and proposes a methodological framework to guide evaluations of the significance and reach of impact that can be attributed to research.
An adapted Grounded Theory Analysis of research impact evaluation frameworks drawn from cross-disciplinary peer-reviewed and grey literature.
Recognizing the subjective nature of impacts as they are perceived by different groups in different times, places and cultures, we define research impact evaluation as the process of assessing the significance and reach of both positive and negative effects of research.
Five types of impact evaluation design are identified encompassing a range of evaluation methods and approaches: i) experimental and statistical methods; ii) textual, oral and arts-based methods; iii) systems analysis methods; iv) indicator-based approaches; and v) evidence synthesis approaches.
Our guidance enables impact evaluation design to be tailored to the aims and context of the evaluation, for example choosing a design to establish a body of research as a necessary (e.g. a significant contributing factor amongst many) or sufficient (e.g. sole, direct) cause of impact, and choosing the most appropriate evaluation design for the type of impact being evaluated.
Using the proposed definitions, typology and methodological framework, researchers, funders and other stakeholders working across multiple disciplines can select a suitable evaluation design and methods to evidence the impact of research from any discipline.
The diagnosis of mental disorder initially appears relatively straightforward: Patients present with symptoms or visible signs of illness; health professionals make diagnoses based primarily on these ...symptoms and signs; and they prescribe medication, psychotherapy, or both, accordingly. However, despite a dramatic expansion of knowledge about mental disorders during the past half century, understanding of their components and processes remains rudimentary. We provide histories and descriptions of three systems with different purposes relevant to understanding and classifying mental disorder. Two major diagnostic manuals—the International Classification of Diseases and the Diagnostic and Statistical Manual of Mental Disorders—provide classification systems relevant to public health, clinical diagnosis, service provision, and specific research applications, the former internationally and the latter primarily for the United States. In contrast, the National Institute of Mental Health's Research Domain Criteria provides a framework that emphasizes integration of basic behavioral and neuroscience research to deepen the understanding of mental disorder. We identify four key issues that present challenges to understanding and classifying mental disorder: etiology, including the multiple causality of mental disorder; whether the relevant phenomena are discrete categories or dimensions; thresholds, which set the boundaries between disorder and nondisorder; and comorbidity, the fact that individuals with mental illness often meet diagnostic requirements for multiple conditions. We discuss how the three systems' approaches to these key issues correspond or diverge as a result of their different histories, purposes, and constituencies. Although the systems have varying degrees of overlap and distinguishing features, they share the goal of reducing the burden of suffering due to mental disorder.
The World Health Organization's proposals for posttraumatic stress disorder (PTSD) in the 11th edition of the International Classification of Diseases, scheduled for release in 2018, involve a very ...brief set of symptoms and a distinction between two sibling disorders, PTSD and Complex PTSD. This review of studies conducted to test the validity and implications of the diagnostic proposals generally supports the proposed 3-factor structure of PTSD symptoms, the 6-factor structure of Complex PTSD symptoms, and the distinction between PTSD and Complex PTSD. Estimates derived from DSM-based items suggest the likely prevalence of ICD-11 PTSD in adults is lower than ICD-10 PTSD and lower than DSM-IV or DSM-5 PTSD, but this may change with the development of items that directly measure the ICD-11 re-experiencing requirement. Preliminary evidence suggests the prevalence of ICD-11 PTSD in community samples of children and adolescents is similar to DSM-IV and DSM-5. ICD-11 PTSD detects some individuals with significant impairment who would not receive a diagnosis under DSM-IV or DSM-5. ICD-11 CPTSD identifies a distinct group who have more often experienced multiple and sustained traumas and have greater functional impairment than those with PTSD.
•Structural analyses suggest PTSD can be measured with 6 symptoms and 3 factors.•Analyses distinguish a 3-factor PTSD from a 6-factor Complex PTSD.•ICD-11 CPSTD is associated with greater functional impairment than PTSD.•Rates of PTSD in adults under ICD-11 are likely to be lower than under DSM-5.
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