1,868 research outputs found
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Parallel changes in gut microbiome composition and function in parallel local adaptation and speciation
The processes of local adaptation and ecological speciation are often strongly shaped by biotic interactions such as competition and predation. One of the strongest lines of evidence that biotic interactions drive evolution comes from repeated divergence of lineages in association with repeated changes in the community of interacting species. Yet, relatively little is known about the repeatability of changes in gut microbial communities and their role in adaptation and divergence of host populations in nature. Here we utilize three cases of rapid, parallel adaptation and speciation in freshwater threespine stickleback to test for parallel changes in associated gut microbiomes. We find that features of the gut microbial communities have shifted repeatedly in the same direction in association with parallel divergence and speciation of stickleback hosts. These results suggest that changes to gut microbiomes can occur rapidly and predictably in conjunction with host evolution, and that host-microbe interactions might play an important role in host adaptation and diversification
Takeover defenses, ownership structure and stock returns in the Netherlands: an empirical analysis
This study empirically examines the relationships between a firmâs takeover defenses and its ownership structure and stock returns. Analyzing data of Dutch listed companies, we find that multiple antitakeover defenses are increasingly adopted when firms are characterized by relatively lower ownership concentration. The evidence supports the hypothesis that more concentrated ownership of shares provides more effective monitoring of managers. As defense\ud
by issuing preferred share has recently been the most widely adopted mechanism in the Netherlands, its impact on shareholdersâ wealth is also analyzed. We observe the presence of two opposing effects of this antitakeover measur
Passive mode-locking theory for conventional and colliding-pulse lasers
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Genetics of adaptation: Experimental test of a biotic mechanism driving divergence in traits and genes.
The genes underlying adaptations are becoming known, yet the causes of selection on genes-a key step in the study of the genetics of adaptation-remains uncertain. We address this issue experimentally in a threespine stickleback species pair showing exaggerated divergence in bony defensive armor in association with competition-driven character displacement. We used semi-natural ponds to test the role of a native predator in causing divergent evolution of armor and two known underlying genes. Predator presence/absence altered selection on dorsal spines and allele frequencies at the Msx2a gene across a generation. Evolutionary trajectories of alleles at a second gene, Pitx1, and the pelvic spine trait it controls, were more variable. Our experiment demonstrates how manipulation of putative selective agents helps to identify causes of evolutionary divergence at key genes, rule out phenotypic plasticity as a sole determinant of phenotypic differences, and eliminate reliance on fitness surrogates. Divergence of predation regimes in sympatric stickleback is associated with coevolution in response to resource competition, implying a cascade of biotic interactions driving species divergence. We suggest that as divergence proceeds, an increasing number of biotic interactions generate divergent selection, causing more evolution in turn. In this way, biotic adaptation perpetuates species divergence through time during adaptive radiation in an expanding number of traits and genes
We need an Anne Frankâs Diary for the Residential Schools
Though the Alberta Governmentâs list of novels authorized for use in grade-school classrooms seemingly values presenting unpleasant historical events to students, narratives by and about First Nations cultures and history are underrepresented, particularly in reference to the residential schools. I discuss how this underrepresentation impedes education and understanding of First Nations cultures and history, and the importance of it being rectified.
 
Terrorism Versus the Right to Privacy: Apple Takes on the DOJ
The long-simmering struggle between two essential American interests came to a dramatic head this week when Apple indicated its intent to appeal a court order directing the company to unlock an iPhone used by Syed Rizwan Farook, one of the San Bernardino terrorists. The case brought to light the enduring and intense battle between privacy rights and national security. For over a decade, Americans have grappled with how to prevent acts of terrorism on American soil without contravening our highly valued right to privacy.
This post was originally published on the Cardozo Arts & Entertainment Law Journal website on April 9, 2016. The original post can be accessed via the Archived Link button above
Perception and Mitigation of Artifacts in a Flat Panel Tiled Display System
Flat panel displays continue to dominate the display market. Larger, higher resolution flat panel displays are now in demand for scientific, business, and entertainment purposes. Manufacturing such large displays is currently difficult and expensive. Alternately, larger displays can be constructed by tiling smaller flat panel displays. While this approach may prove to be more cost effective, appropriate measures must be taken to achieve visual seamlessness and uniformity.
In this project we conducted a set of experiments to study the perception and mitigation of image artifacts in tiled display systems. In the first experiment we used a prototype tiled display to investigate its current viability and to understand what critical perceptible visual artifacts exist in this system. Based on word frequencies of the survey responses, the most disruptive artifacts perceived were ranked. On the basis of these findings, we conducted a second experiment to test the effectiveness of image processing algorithms designed to mitigate some of the most distracting artifacts without changing the physical properties of the display system. Still images were processed using several algorithms and evaluated by observers using magnitude scaling. Participants in the experiment noticed statistically significant improvement in image quality from one of the two algorithms. Similar testing should be conducted to evaluate the effectiveness of the algorithms on video content. While much work still needs to be done, the contributions of this project should enable the development of an image processing pipeline to mitigate perceived artifacts in flat panel display systems and provide the groundwork for extending such a pipeline to realtime applications
Assessing the Efficacy of International Peacekeeping in Bosnia
This specific research seeks to determine which international mechanisms exist to protect human rights and what factors influence the efficacy of these mechanisms. Assessing the efficacy of international peacekeeping in the Bosnian genocide is immensely significant as the actions taken in Bosnia have set the precedent for humanitarian intervention since that time. In order to gain a broad and encompassing understanding of the complexities of the Bosnian genocide I broke my research down into five categories. Initially, this research seeks to explain the background and context out of which the Bosnian genocide arose. Then it addresses the controversial question of humanitarian intervention, through seeking to understand the main arguments for and against intervention in the given timeframe and analyzing the effect they had on humanitarian intervention in Bosnia.
It also addresses global diplomatic climate in the wake of the Cold War to determine its role in shaping international involvement in the Bosnian crisis. Once the framework had been established, this research seeks to understand the role of three prominent peacekeeping bodies; the United Nations (UN), the North Atlantic Treaty Organization (NATO) and the United States. It addresses the role that each peacekeeping body played, the factors, which influenced their involvement, and the ramifications of their actions. Most importantly, this research seeks to understand and emphasize the importance of an engaged and active citizenry in protecting human rights. The efficacy of all three peacekeeping bodies addressed in this research is dependent on the level of pressure and support from the citizenry. A disengaged citizenry is detrimental to the process of humanitarian intervention, regardless of the other mechanisms in place, as intervention is typically oppositional to national and economic interests.
Therefore, without an engaged citizenry governments and other international organizations are not held accountable for neglecting humanitarian intervention. The genocide in Bosnia serves as a model situation illuminating the consequences of a disengaged citizenry. In an era where human rights were on the forefront, but public support for global involvement was diminishing the importance of an engaged citizenry become irrefutably clear
Third Nature: Landscape And Ethics In The Early Modern Iberian World
How do the rituals of poetic language refashion and provision our creaturely needs for nourishment, shelter, and community at moments when these seem to overwhelm natureâs capacities? What are the spaces most sensitive to the incursion of new structures for thinking and displaying the self upon traditional forms that are local, communal, and sacred? And how does pastoralâthe courtly literature of poet-shepherdsâemploy stylized, figurative landscapes to inscribe an ethics for inhabiting the natural environment? The systematic exploration of the world in the early modern period (ca. 1500â1700 AD) transformed how the human condition and its place in nature were represented in the topographies, natural histories, and herbals that I argue constituted an early modern practice of ecology. In this project, I argue that pastoral literature takes part in this practice, a position that challenges conventional interpretations of its landscapes as idealized backdrops that retreat from political and environmental concerns. I propose instead that as a form of ecological thought (that is, as a resource for apprehending nature and its relationship to the human), pastoral expresses not a withdrawal but an engagement with nature. The persistent invocation of a âthirdâ natureâagainst first (organic, intrinsic) or second (cultural, habitual) naturesâin the pastoral of early modern Spain represents an awareness of how its characters remake and renew their relationships to each other and to their surroundings: their habits of care and rituals of attention are not empty forms but respond meaningfully to their passage through a range of natural and built environments. Not just green pastures but sheepwalks and forests, wastelands and walled gardens, ruined cities and barren shores are some of the landscapes that embody the shepherdsâ efforts to give voice to the complexity of desire, the fragility of memory, the pain of aging, the fluidity of gender, and the nature of community
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