A Rhetorical Analysis of the Scientific-Romantic Synthesis in the Popular Scientific Writings of Lewis Thomas.

As physician, educator, former medical administrator, and member of the National Academy of Sciences, Lewis Thomas has been one of the most eloquent spokespersons for the scientific community. This dissertation analyzes twenty-four of Thomas\u27 popular scientific essays. These essays reveal a union of traditional scientific values and popular romantic themes, what is called here a rhetorical synthesis. The term synthesis is understood as the putting of two or more things together to form a whole, particularly suggesting a reconciliation of two philosophically opposing forces. Thomas\u27 essays reflect a synthesis insofar as they merge what have traditionally been thought to be two opposing philosophical views of reality, science and romanticism. This synergistic reconciliation of two opposing philosophical forces is understood to produce a third philosophical view of reality, which combines elements from the two original views of reality yet is a separate, independent philosophical perspective. Thomas\u27 synthesis of traditional scientific values and popular romantic themes produces a particularly humane version of science, and is rhetorical insofar as it is purposefully designed to produce a romantic science capable of mitigating the long-standing dispute between science and humanism and to allay the public\u27s fear about the social consequences of science. Thomas\u27 romantic orientation toward the world is characterized by six major themes: (1) faith in the unconscious mind, (2) a vindication of the individual, (3) a predilection for diversity, ambiguity, and imperfection, (4) a preoccupation with qualities that are different, remote or mysterious in humans, (5) wonder and awe of nature, and (6) a concern for humankind\u27s moral characteristics. These six romantic tenets are identified as they appear in Thomas\u27 essays; the themes\u27 strategic location, function and rhetorical significance is assessed. In addition, this dissertation examines the scientific world view as it is set against the romantic world view in Thomas\u27 overall rhetorical design. This study also investigates how Thomas\u27 romantic version of science clarifies the moral role of science in society. This dissertation concludes that Thomas\u27 scientific-romantic synthesis operates as an effective rhetorical form for mediating the traditional controversy between science and humanism, and for establishing a more cooperative relationship between the scientific community and the general public

Spatial Memory in Black-capped Chickadees: Studies of Adult Hippocampal Neurogenesis and Win-Shift/Win-Stay Spatial Search

Two cognitive adaptations were studied in Black-capped chickadees through tests of adult hippocampal neurogenesis and Win-shift/Win-stay spatial search. Neurogenesis has been proposed to aid memory, therefore it was hypothesized that birds with decreased neurogenesis would perform poorer than controls in hippocampal-dependent spatial working and reference memory tasks followed by a reversal. Subjects with decreased neurogenesis, caused by the neurotoxin MAM, reversed slower than controls, suggesting that neurogenesis may contribute to differentiating similar memories, although this effect was nonsignificant. Win-shift/Win-stay foraging behavior is an adaptation to the replenishing and depleting nature of food. Since chickadees forage on food that depletes quickly and slowly, it was hypothesized that chickadees would change their foraging strategy in response to reward contingency in a spatial working memory task. I found that chickadees did not respond to reward contingency and instead relied on individual preferences. Sweeping general models do not always apply to complex foraging birds

Vector-borne pathogens found in carnivores in wild Namibia

Dissertação de Mestrado Integrado em Medicina VeterináriaThis dissertation aimed to identify and molecularly characterize vector-borne pathogens from several parasite families, all possessing stages found in peripheral blood, from a wide variety of free-ranging carnivores living in Namibia, in the southern part of Africa. Blood samples collected from 9 bat-eared foxes (Otocyon megalotis), 17 brown hyenas (Parahyaena brunnea), 19 spotted hyenas (Crocuta crocuta) and 85 cheetahs (Acinonyx jubatus) were screened by Polymerase Chain Reactions (PCRs) and tested for pathogens of the Onchocercidae family, the order Piroplasmida, bacteria from the Anaplasmataceae and the Rickettsiaceae families and, lastly, the Hepatozoidae family. The PCRs targeted both the ITS-2 and 12S, 18S, 16S, 18S and 18S rRNA genes respectively and were followed by nucleotide sequencing. In total, sampled animals showed a 43.1% rate of Onchocercidae infection, 67.7% of Piroplasmida, 60% of them were positive for Anaplasmataceae, 10% for Rickettsiaceae and Hepatozoidae were detected in 47.7% of them. Obtained filaroid sequences showed high homologies with both Acanthocheilonema reconditum and Acanthocheilonema dracunculoides and further phylogenetic analysis were performed in both brown and spotted hyenas, with the construction of a phylogenetic tree. Piroplasmida results were not studied any further. For Anaplasmataceae, subsequent sequencing results indicated high similarity with both Anaplasma phagocytophilum and Anaplasma platys and varied PCR protocols were conducted in order to differentiate between these organisms, but no conclusions were reached. The Rickettsiaceae found displayed high homologies with Rickettsia raoultii. And finally, the Hepatozoidae infection showed to be a mixed one with both Hepatozoon canis and Hepatozoon felis. These results are important not only on a conservation level for the infected host species, but are also relevant for domestic animals coexisting in the surrounding areas, as well as humans, especially since a few of the parasites found may have zoonotic potential. Future studies should focus on understanding vectors, transmission routes, infection dynamics and host specificity in order to better evaluate the possible danger these infections may withhold.RESUMO - Agentes patogénicos transmitidos por vetores presentes em carnívoros na Namíbia - Esta dissertação teve como principal objetivo identificar e caracterizar molecularmente agentes patogénicos transmitidos por vetores de várias famílias parasitárias, com o aspeto em comum de todas possuírem fases do desenvolvimento encontradas no sangue, de espécies variadas de carnívoros selvagens que habitam na Namíbia, no Sul de África. Foram testadas amostras sanguíneas de 9 raposas-orelhas-de-morcego (Otocyon megalotis), 17 hienas-castanhas (Parahyaena brunnea), 19 hienas-malhadas (Crocuta crocuta) e 85 chitas (Acinonyx jubatus) por PCR e analisadas para pesquisa de parasitas da família Onchocercidae, da ordem Piroplasmida, bactérias das famílias Anaplasmataceae e Rickettsiaceae e, finalmente, da família Hepatozoidae. Os PCRs foram direcionados aos genes do rRNA ITS-2 e 12S, 18S, 16S, 18S e 18S respetivamente e foram seguidos de sequenciação de nucleótidos. Na totalidade, os animais testados mostraram uma taxa de infeção de 43.1% por Onchocercidae, de 67.7% de Piroplasmida, 60% deles tiveram resultados positivos para Anaplasmataceae, 10% para Rickettsiaceae e Hepatozoidae foram detetados em 47.7% da população. As sequências obtidas de filarídeos, mostraram possuir elevadas homologias com Acanthocheilonema reconditum e Acanthocheilonema dracunculoides, e estudos filogenéticos mais intensivos foram realizados, nomeadamente uma árvore filogenética que inclui ambas as espécies de hienas. Os resultados relativos a Piroplasmida não foram aprofundados. Para as Anaplasmataceae, as sequenciações subsequentes indicaram elevada similaridade com Anaplasma phagocytophilum e Anaplasma platys e múltiplos protocolos de PCRs foram efetuados, com o intuito de diferenciar entre estas duas espécies, mas não foram retiradas quaisquer conclusões. As Rickettsiaceae presentes evidenciaram fortes semelhanças com Rickettsia raoultii. E finalmente, as infeções por Hepatozoidae mostraram ser uma infeção mista por ambos Hepatozoon canis e Hepatozoon felis. A importância destes resultados não se limita apenas à conservação das espécies animais em causa, mas são também relevantes em termos dos animais domésticos coabitantes na mesma região, assim como humanos, especialmente tendo em conta o possível potencial zoonótico de algumas espécies parasitárias. Estudos futuros devem ter como principais objetivos o estudo dos vetores respetivos, tipo de transmissão, dinâmica da infeção e especificidade parasitária, para melhor avaliar os possíveis perigos que podem advir da presença destes parasitas.N/

2024 Student Symposium Program and Book of Abstracts

The mission of the UMaine Student Symposium is to give graduate and undergraduate students from UMaine and UMaine Machias the opportunity to showcase their work, research, and creative activities to the greater community, fostering conversations and collaborations that will benefit the future of Maine and beyond

Gene and Genome Parameters of Mammalian Liver Circadian Genes (LCGs)

The mammalian circadian system controls various physiology processes and behavior responses by regulating thousands of circadian genes with rhythmic expressions. In this study, we redefined circadian-regulated genes based on published results in the mouse liver and compared them with other gene groups defined relative to circadian regulations, especially the non-circadian-regulated genes expressed in liver at multiple molecular levels from gene position to protein expression based on integrative analyses of different datasets from the literature. Based on the intra-tissue analysis, the liver circadian genes or LCGs show unique features when compared to other gene groups. First, LCGs in general have less neighboring genes and larger in both genomic and 3′-UTR lengths but shorter in CDS (coding sequence) lengths. Second, LCGs have higher mRNA and protein abundance, higher temporal expression variations, and shorter mRNA half-life. Third, more than 60% of LCGs form major co-expression clusters centered in four temporal windows: dawn, day, dusk, and night. In addition, larger and smaller LCGs are found mainly expressed in the day and night temporal windows, respectively, and we believe that LCGs are well-partitioned into the gene expression regulatory network that takes advantage of gene size, expression constraint, and chromosomal architecture. Based on inter-tissue analysis, more than half of LCGs are ubiquitously expressed in multiple tissues but only show rhythmical expression in one or limited number of tissues. LCGs show at least three-fold lower expression variations across the temporal windows than those among different tissues, and this observation suggests that temporal expression variations regulated by the circadian system is relatively subtle as compared with the tissue expression variations formed during development. Taken together, we suggest that the circadian system selects gene parameters in a cost effective way to improve tissue-specific functions by adapting temporal variations from the environment over evolutionary time scales

The Genetics of Familial Leukaemia and Myelodysplasia

PhDBackground & Aim: While the majority of myelodysplasia and acute myeloid leukaemia (MDS/AML) cases are sporadic, rare familial predisposition syndromes have been delineated and are regarded a separate disease entity in the 2016 WHO classification system. Germline mutations in 14 disease genes have been uncovered thus far, with GATA2 representing one of the key transcriptional regulators commonly mutated in inherited leukaemias. The rarity of these familial cases opens the door to fundamental questions in biology, one of which is the phenomenon of reduced penetrance posing a clinical challenge particularly when identifying “silent” mutation carriers for genetic screening and exclusion as potential stem cell transplant donors. We have noted that this is indeed a feature within certain GATA2-mutated families, especially those carrying germline missense mutations such as (p.Thr354Met). In our example, two first-degree cousins developed MDS/AML with monosomy 7 while a third cousin presented with significant monocytopenia and neutropenia. This contrasted with the parental generation mutation carriers who all remain symptom free into their mid-late 60s. This thesis therefore sets out to investigate the molecular mechanisms underlying the reduced penetrance and clinical heterogeneity observed within a GATA2-mutated family with a view of identifying molecular features that distinguish between these two groups of mutation carriers. Results: Deep targeted sequencing of 33 genes frequently mutated in MDS/AML revealed acquisition of somatic ASXL1 mutation (p.Gly646TrpfsTer12) in all affected cousins with no mutations detected in asymptomatic family members. It was noteworthy that the variant allele frequency was lower (12%) in the third cousin symptomatic carrier and remained stable (range 12-6%) over a 6-year monitoring period. Total GATA2 expression was lower in the symptomatic compared with asymptomatic carriers as assessed by RT-qPCR and remarkably this was associated with monoallelic expression favouring the mutant GATA2 allele with loss of the wild-type (WT) allele expression. Temporal analysis of the symptomatic carrier over a 6-year disease period demonstrated a reactivation of the WT allele expression 3 years later, coinciding with a persistent improvement in haematological parameters. We believe these allele-specific changes in GATA2 expression are driven by dynamic epigenetic reprogramming that include changes in DNA methylation and chromatin mark deposition. Using a SNP (rs1806462 [C/A]) that generates/removes a CpG dinucleotide within GATA2 promoter region, we first assessed allele-specific differences in DNA methylation by bisulphite sequencing. This demonstrated a significant increase in promoter methylation in the WT allele that returned to normal levels at later time-points. We then assessed allele-specific deposition of H3K4me3 and H3K27me3 chromatin marks by chromatin immunoprecipitation (ChIP). Sanger sequencing revealed a significant enrichment in the deposition of H3K4me3 activating mark on the mutant allele at diagnosis that was reversed at later follow-up, correlating with reactivation of the WT allele expression. Conclusion: Reduced penetrance is a feature of many families with inherited forms of MDS/AML which may be governed by the acquisition of additional co-operating mutations (e.g. ASXL1). In this thesis, however, we show that changes in the WT:mutant GATA2 allele expression ratio as a result of local and allele-specific changes in DNA methylation and chromatin mark deposition may also influence the penetrance of the germline mutation, adding another layer of complexity to the (epi)genetic basis of familial MDS/AML

The Influence of Diet on the Mammalian Gut Microbiome

The mammalian gut is residence to a large microbial community whose collective set of millions of genes: microbiome) encodes a vast array of functions, including many that process dietary components. Few tools are available to change the microbiome\u27s properties to promote host health because the factors governing community assembly and operation are poorly understood. My thesis focused on the impact of one factor, host diet. I used a variety of experimental and computational methods to perform a comparative metagenomic study of the fecal communities of 39 diverse mammals to assess microbiome variation. These animals included herbivores, omnivores and carnivores representing different portions of the mammalian tree, Targeted sequencing of the bacterial 16S rRNA gene and shotgun gene sequencing of total fecal DNA revealed that animals with similar diets possessed similar microbiomes, both in terms of bacterial species detected and the functions that their genomes encoded. A large number of genes were found in all gut microbiomes, but the relative abundance of many traits was differentially represented in carnivorous compared to herbivorous hosts, demonstrating that diet can shape a microbiome. We next studied microbiome variation within a single host species consuming a range of diets, using a population of 18 calorie-restricted adult humans with carefully recorded dietary intake. Even in these free-living, unrelated individuals, the amount of protein and dietary fiber consumed was significantly correlated with the variation in the gut metagenomes. My second study addressed the period of dramatic dietary variation in human life when breast fed infants are weaned. The study population was a birth cohort of 103 children born in Bangladesh, some of who developed malnutrition during the first two years of life. My results demonstrate that despite large inter-personal variation, common patterns are found in the establishment of bacterial species and functions as the children age. The data revealed a developmental pattern of human gut microbiome functional assembly. This was exemplified by the emergence of glycan degradation capacity in all children studied. Some of the taxonomic and functional changes can be correlated with the host\u27s diet, but many properties of the developing infant microbiome cannot be explained by diet alone

Grand Celebration: 10th Anniversary of the Human Genome Project

In 1990, scientists began working together on one of the largest biological research projects ever proposed. The project proposed to sequence the three billion nucleotides in the human genome. The Human Genome Project took 13 years and was completed in April 2003, at a cost of approximately three billion dollars. It was a major scientific achievement that forever changed the understanding of our own nature. The sequencing of the human genome was in many ways a triumph for technology as much as it was for science. From the Human Genome Project, powerful technologies have been developed (e.g., microarrays and next generation sequencing) and new branches of science have emerged (e.g., functional genomics and pharmacogenomics), paving new ways for advancing genomic research and medical applications of genomics in the 21st century. The investigations have provided new tests and drug targets, as well as insights into the basis of human development and diagnosis/treatment of cancer and several mysterious humans diseases. This genomic revolution is prompting a new era in medicine, which brings both challenges and opportunities. Parallel to the promising advances over the last decade, the study of the human genome has also revealed how complicated human biology is, and how much remains to be understood. The legacy of the understanding of our genome has just begun. To celebrate the 10th anniversary of the essential completion of the Human Genome Project, in April 2013 Genes launched this Special Issue, which highlights the recent scientific breakthroughs in human genomics, with a collection of papers written by authors who are leading experts in the field

Evaluating genetic diversity in the critically endangered orange-bellied parrot: informing species management

The orange-bellied parrot (Neophema chrysogaster) is a critically endangered small Australian parrot. It was the first species in Australia to have a single species Recovery Plan developed, and efforts to conserve the species have been active for over 35 years. Despite this, the wild population has declined to fewer than 20 individuals. Approximately 450 birds are maintained in a captive insurance population. This thesis investigated genetic diversity across both wild and captive populations of the OBP between 2010 and 2018. Relatively low genome-wide diversity was found across the species, as measured with 7768 SNP markers. Low functional diversity was also found at immune genes the Toll-like receptors, consistent with other studies of critically endangered birds. Although genetic diversity in the wild population decreased following removal of 21 fledglings in 2010/11 to supplement the captive population, annual releases of captive birds since 2013, and their successful breeding post-release, have improved wild diversity levels. Wild and captive populations were not found to be genetically distinct. Inbreeding depression was investigated by modelling correlations between genetic diversity and 1) differential responses to infectious disease agents, and 2) reproductive success. No evidence of inbreeding depression was found, but a relationship between younger age and greater reproductive success was identified. Finally, a preliminary phylogeny of the genus Neophema was produced using two mitochondrial markers, and was found to support some of the current structure within the genus, but was ultimately inconclusive as to placement of the OBP. This work has explored genetic diversity in the OBP to a greater extent than ever previously. It has helped inform management of the species and will act as a foundation for future studies