Applying Early Existential Critiques to Contemporary Themes in American Culture

Charles Taylor, Carl Elliot, Alexis De Tocqueville, and Lionel Trilling have presented and critically analyzed a number of ideals that animate currents in contemporary American Culture, which include authenticity, sincerity, pluralism, subjectivism, and self-actualization, but these ideals do not harmoniously coexist; rather, they inevitably conflict. These notions have been realized in a way that is unique in their current understandings. Though there is the appearance of some homogeneity amongst these themes, they inevitably clash and contain internal tensions. The philosophers Kierkegaard and Nietzsche respond to many of the ideas that underlie these modern notions. Though differing in degrees, these critiques anticipate many of the problems that have arisen within discussion of contemporary culture. The themes that Taylor, Elliot, De Tocqueville, and Trilling outline are not limited to those notions that Kierkegaard and Nietzsche criticized. Rather, some cultural attitudes find their lineage in their respective philosophies. Both the historical tradition behind, and the contemporary definitions of these themes, need to be understood in order to explain the fragmented nature of contemporary culture. Kierkegaard and Nietzsche offer a historical perspective to the definitions given by Taylor, Elliot, and Trilling. Understanding the multifarious and contradictory foundations of contemporary culture is essential to demonstrating the potential paradox of realizing a consistent language of contemporary culture, and may include the inability to uphold these themes

Aspects of Biological Explanation

This dissertation is an evaluation of some strategies used for understanding the biological world. It argues that the complexity of living systems challenges the adequacy of traditional approaches to scientific explanation. An examination of the empirical details—especially those at the microscopic and nano scales—highlights the limitations of mechanistic explanation, common habits of causal reasoning, and theories of individuality. According to this analysis, starting with broad generalizations of how the world is, or a single universal theory of how it ought to be investigated or explained, has things entirely backwards. Instead, we ought to start by looking at the important processes, relations, and interactions uncovered by the sciences, carefully building towards general claims. In chapter one, I examine and challenge a dominant characterization of mechanistic explanation. I develop an alternative approach that situates biological processes as falling along a multidimensional gradient—with some processes being paradigmatic cases of mechanisms and some being marginal cases. In chapter two I trace recent developments in biology where the study of robustness has become increasingly important. I develop a general taxonomy of robustness to help clarify links between the study of robustness in different fields, and argue for a shift towards incorporating more top-down, system-level approaches into general accounts of explanation. In chapter three I examine aspects of causal reasoning in biology. I provide a novel distinction between two types of difficulties encountered while reasoning about biological systems. In the face of these problems I argue that approaches to explanation are best seen as heuristics, which focuses our attention on both how our conceptual tools resolve problems, and when and where they can break down. In the final chapter I turn to a debate at the interface of philosophy and biology about whether we need to reevaluate our understanding of the biological world because we—along with every other multicellular organism—are, and always have been, multispecies entities

Gateways to Hawai‘i: Genetic Population Structure of the Tropical Sea Cucumber Holothuria atra

Holothuria atra is one of the most common and widest ranging tropical, coral reef sea cucumbers in the world, and here we examine population genetic structure based on mitochondrial COI to aid in determining the appropriate scale for coral reef management. Based on SAMOVA, AMOVA and BARRIER analyses, we show that despite its large range, H. atra has hierarchical, fine-scale population structure driven primarily by between-archipelago barriers, but with significant differences between sites within an archipelago as well. Migrate analyses along with haplotype networks and patterns of haplotype diversity suggest that Hawai‘i and Kingman reef are important centers of the genetic diversity in the region rather than an evolutionary dead-end for migrants from the Indo-Pacific. Finally we show that for H. atra Kingman Reef is the most likely stepping stone between Hawai‘i and the rest of the Pacific, not Japan or Johnston Atoll as previously presumed. Based on our data, Johnston Atoll can instead be seen as an outpost of the Northwestern Hawaiian Islands rather than a gateway to the Hawaiian Archipelago

Ice ages and butterflyfishes: Phylogenomics elucidates the ecological and evolutionary history of reef fishes in an endemism hotspot

For tropical marine species, hotspots of endemism occur in peripheral areas furthest from the center of diversity, but the evolutionary processes that lead to their origin remain elusive. We test several hypotheses related to the evolution of peripheral endemics by sequencing ultraconserved element (UCE) loci to produce a genome-scale phylogeny of 47 butterflyfish species (family Chaetodontidae) that includes all shallow water butterflyfish from the coastal waters of the Arabian Peninsula (i.e., Red Sea to Arabian Gulf) and their close relatives. Bayesian tree building methods produced a well-resolved phylogeny that elucidated the origins of butterflyfishes in this hotspots of endemism. We show that UCEs, often used to resolve deep evolutionary relationships, represent an important tool to assess the mechanisms underlying recently diverged taxa. Our analyses indicate that unique environmental conditions in the coastal waters of the Arabian Peninsula probably contributed to the formation of endemic butterflyfishes. Older endemic species are also associated with narrow versus broad depth ranges, suggesting that adaptation to deeper coral reefs in this region occurred only recently (<1.75 Ma). Even though deep reef environments were drastically reduced during the extreme low sea level stands of glacial ages, shallow reefs persisted, and as such there was no evidence supporting mass extirpation of fauna in this region

Responses to environmental enrichment differ with sex and genotype in a transgenic mouse model of Huntington's disease.

BACKGROUND: Environmental enrichment (EE) in laboratory animals improves neurological function and motor/cognitive performance, and is proposed as a strategy for treating neurodegenerative diseases. EE has been investigated in the R6/2 mouse model of Huntington's disease (HD), where increased social interaction, sensory stimulation, exploration, and physical activity improved survival. We have also shown previously that HD patients and R6/2 mice have disrupted circadian rhythms, treatment of which may improve cognition, general health, and survival. METHODOLOGY/PRINCIPAL FINDINGS: We examined the effects of EE on the behavioral phenotype and circadian activity of R6/2 mice. Our mice are typically housed in an "enriched" environment, so the EE that the mice received was in addition to these enhanced housing conditions. Mice were either kept in their home cages or exposed daily to the EE (a large playground box containing running wheels and other toys). The "home cage" and "playground" groups were subdivided into "handling" (stimulated throughout the experimental period) and "no-handling" groups. All mice were assessed for survival, body weight, and cognitive performance in the Morris water maze (MWM). Mice in the playground groups were more active throughout the enrichment period than home cage mice. Furthermore, R6/2 mice in the EE/no-handling groups had better survival than those in the home cage/no-handling groups. Sex differences were seen in response to EE. Handling was detrimental to R6/2 female mice, but EE increased the body weight of male R6/2 and WT mice in the handling group. EE combined with handling significantly improved MWM performance in female, but not male, R6/2 mice. CONCLUSIONS/SIGNIFICANCE: We show that even when mice are living in an enriched home cage, further EE had beneficial effects. However, the improvements in cognition and survival vary with sex and genotype. These results indicate that EE may improve the quality of life of HD patients, but we suggest that EE as a therapy should be tailored to individuals

There's No Place Like Home: Crown-of-Thorns Outbreaks in the Central Pacific Are Regionally Derived and Independent Events

One of the most significant biological disturbances on a tropical coral reef is a population outbreak of the fecund, corallivorous crown-of-thorns sea star, Acanthaster planci. Although the factors that trigger an initial outbreak may vary, successive outbreaks within and across regions are assumed to spread via the planktonic larvae released from a primary outbreak. This secondary outbreak hypothesis is predominantly based on the high dispersal potential of A. planci and the assertion that outbreak populations (a rogue subset of the larger population) are genetically more similar to each other than they are to low-density non-outbreak populations. Here we use molecular techniques to evaluate the spatial scale at which A. planci outbreaks can propagate via larval dispersal in the central Pacific Ocean by inferring the location and severity of gene flow restrictions from the analysis of mtDNA control region sequence (656 specimens, 17 non-outbreak and six outbreak locations, six archipelagos, and three regions). Substantial regional, archipelagic, and subarchipelagic-scale genetic structuring of A. planci populations indicate that larvae rarely realize their dispersal potential and outbreaks in the central Pacific do not spread across the expanses of open ocean. On a finer scale, genetic partitioning was detected within two of three islands with multiple sampling sites. The finest spatial structure was detected at Pearl & Hermes Atoll, between the lagoon and forereef habitats (<10 km). Despite using a genetic marker capable of revealing subtle partitioning, we found no evidence that outbreaks were a rogue genetic subset of a greater population. Overall, outbreaks that occur at similar times across population partitions are genetically independent and likely due to nutrient inputs and similar climatic and ecological conditions that conspire to fuel plankton blooms

Mechanisms of adverse effects of anti-VEGF therapy for cancer

Advances in understanding the role of vascular endothelial growth factor (VEGF) in normal physiology are giving insight into the basis of adverse effects attributed to the use of VEGF inhibitors in clinical oncology. These effects are typically downstream consequences of suppression of cellular signalling pathways important in the regulation and maintenance of the microvasculature. Downregulation of these pathways in normal organs can lead to vascular disturbances and even regression of blood vessels, which could be intensified by concurrent pathological conditions. These changes are generally manageable and pose less risk than the tumours being treated, but they highlight the properties shared by tumour vessels and the vasculature of normal organs

Defining Boundaries for Ecosystem-Based Management: A Multispecies Case Study of Marine Connectivity across the Hawaiian Archipelago

Determining the geographic scale at which to apply ecosystem-based management (EBM) has proven to be an obstacle for many marine conservation programs. Generalizations based on geographic proximity, taxonomy, or life history characteristics provide little predictive power in determining overall patterns of connectivity, and therefore offer little in terms of delineating boundaries for marine spatial management areas. Here, we provide a case study of 27 taxonomically and ecologically diverse species (including reef fishes, marine mammals, gastropods, echinoderms, cnidarians, crustaceans, and an elasmobranch) that reveal four concordant barriers to dispersal within the Hawaiian Archipelago which are not detected in single-species exemplar studies. We contend that this multispecies approach to determine concordant patterns of connectivity is an objective and logical way in which to define the minimum number of management units and that EBM in the Hawaiian Archipelago requires at least five spatially managed regions