169 research outputs found
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An Overview of University of Texas at Austin 2009-2012 Investigations of the Rogers Spring Archaeological Site
The purpose of this thesis is to examine the artifact assemblages of the Rogers Spring (41TV39)
Archaeological Site excavations from the University of Texas field school in 2009-2012. These
excavations were led by Fred Valdez, Jr. under Texas Antiquities Permit 5289. The Roger
Springs Archaeological Site is rich in history and includes both historic and prehistoric contexts.
I begin with a brief introduction to the Roger Springs Site focusing on the general site location
and burned rock middens. I then discuss the historic settlement by the Roger family and all
of the previous excavations at the site in 1933, 1972, and 2008. This will provide an
understanding of the artifacts discussed in previous projects as well as give a general overview
of which middens had already been examined prior to the 2009-2012 excavations.
After establishing the background of the site, I then explain the methods of inventorying the
artifacts at the Texas Archeological Research Laboratory (TARL). This also includes the process
of locating additional excavation materials such as lot forms and student notes. I utilize
information from these forms to create an overview of the excavationâs location and general
descriptions of the units represented in the report (soil consistency, proximity to midden 5, and
ash content).
In the final analysis, I examine the materials uncovered during the field school and describe them
within the prehistoric and historic context of Central Texas. I will focus on the typed projectile
points found at the site and give an overview of the time periods that they are associated with.
Based solely on the projectile points, there is evidence of human occupation from the Early
Archaic through the Transitional Archaic. The final section discusses the possibility of further
research with the material currently being housed at TARL.Anthropolog
Linear plasmids and the rate of sequence evolution in plant mitochondrial genomes
Includes bibliographical references (pages 373-374).The mitochondrial genomes of flowering plants experience frequent insertions of foreign sequences, including linear plasmids that also exist in standalone forms within mitochondria, but the history and phylogenetic distribution of plasmid insertions is not well known. Taking advantage of the increased availability of plant mitochondrial genome sequences, we performed phylogenetic analyses to reconstruct the evolutionary history of these plasmids and plasmid-derived insertions. Mitochondrial genomes from multiple land plant lineages (including liverworts, lycophytes, ferns, and gymnosperms) include fragmented remnants from ancient plasmid insertions. Such insertions are much more recent and widespread in angiosperms, in which approximately 75% of sequenced mitochondrial genomes contain identifiable plasmid insertions. Although conflicts between plasmid and angiosperm phylogenies provide clear evidence of repeated horizontal transfers, we were still able to detect significant phylogenetic concordance, indicating that mitochondrial plasmids have also experienced sustained periods of (effectively) vertical transmission in angiosperms. The observed levels of sequence divergence in plasmid-derived genes suggest that nucleotide substitution rates in these plasmids, which often encode their own viral-like DNA polymerases, are orders of magnitude higher than in mitochondrial chromosomes. Based on these results, we hypothesize that the periodic incorporation of mitochondrial genes into plasmids contributes to the remarkable heterogeneity in substitution rates among genes that has recently been discovered in some angiosperm mitochondrial genomes. In support of this hypothesis, we show that the recently acquired ÏtrnP-trnW gene region in a maize linear plasmid is evolving significantly faster than homologous sequences that have been retained in the mitochondrial chromosome in closely related grasses.Published with support from the Colorado State University Libraries Open Access Research and Scholarship Fund
Rewiring of Aminoacyl-tRNA Synthetase Localization and Interactions in Plants With Extensive Mitochondrial tRNA Gene Loss
The number of tRNAs encoded in plant mitochondrial genomes varies considerably. Ongoing loss of bacterial-like mitochondrial tRNA genes in many lineages necessitates the import of nuclear-encoded counterparts that share little sequence similarity. Because tRNAs are involved in highly specific molecular interactions, this replacement process raises questions about the identity and trafficking of enzymes necessary for the maturation and function of newly imported tRNAs. In particular, the aminoacyl-tRNA synthetases (aaRSs) that charge tRNAs are usually divided into distinct classes that specialize on either organellar (mitochondrial and plastid) or nuclear-encoded (cytosolic) tRNAs. Here, we investigate the evolution of aaRS subcellular localization in a plant lineage (Sileneae) that has experienced extensive and rapid mitochondrial tRNA loss. By analyzing full-length mRNA transcripts (PacBio Iso-Seq), we found predicted retargeting of many ancestrally cytosolic aaRSs to the mitochondrion and confirmed these results with colocalization microscopy assays. However, we also found cases where aaRS localization does not appear to change despite functional tRNA replacement, suggesting evolution of novel interactions and charging relationships. Therefore, the history of repeated tRNA replacement in Sileneae mitochondria reveals that differing constraints on tRNA/aaRS interactions may determine which of these alternative coevolutionary paths is used to maintain organellar translation in plant cells
Evolution by Any Other Name: Antibiotic Resistance and Avoidance of the E-Word
The word "evolution" is rarely used in papers from medical journals describing antimicrobial resistance, which may directly impact public perception of the importance of evolutionary biology in our everyday lives
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PATH-38. ROSETTE-FORMING GLIONEURONAL TUMOR IS DEFINED BY FGFR1 ACTIVATING ALTERATIONS WITH FREQUENT ACCOMPANYING PI3K AND MAPK PATHWAY MUTATIONS
Abstract
BACKGROUND
Rosette-forming glioneuronal tumor (RGNT) is an uncommon CNS tumor originally described in the fourth ventricle characterized by a low-grade glial neoplasm admixed with a rosette-forming neurocytic component.
METHODS
We reviewed clinicopathologic features of 42 patients with RGNT. Targeted next-generation sequencing was performed, and genome-wide methylation profiling is underway.
RESULTS
The 20 male and 22 female patients had a mean age of 25 years (range 3â47) at time of diagnosis. Tumors were located within or adjacent to the lateral ventricle (n=16), fourth ventricle (15), third ventricle (9), and spinal cord (2). All 31 tumors assessed to date contained FGFR1 activating alterations, either in-frame gene fusion, kinase domain tandem duplication, or hotspot missense mutation in the kinase domain (p.N546 or p.K656). While 7 of these 31 tumors harbored FGFR1 alterations as the solitary pathogenic event, 24 contained additional pathogenic alterations within PI3-kinase or MAP kinase pathway genes: 5 with additional PIK3CA and NF1 mutations, 4 with PIK3CA mutation, 3 with PIK3R1 mutation (one of which also contained focal RAF1 amplification), 5 with PTPN11 mutation (one with additional PIK3R1 mutation), and 2 with NF1 deletion. The other 5 cases demonstrated anaplastic features including hypercellularity and increased mitotic activity. Among these anaplastic cases, 3 harbored inactivating ATRX mutations and two harbored CDKN2A homozygous deletion, in addition to the FGFR1 alterations plus other PI3-kinase and MAP kinase gene mutations seen in those RGNT without anaplasia.
CONCLUSION
Independent of ventricular location, RGNT is defined by FGFR1 activating mutations or rearrangements, which are frequently accompanied by mutations involving PIK3CA, PIK3R1, PTPN11, NF1, and KRAS. Whereas pilocytic astrocytoma and ganglioglioma are characterized by solitary activating MAP kinase pathway alterations (e.g. BRAF fusion or mutation), RGNT are genetically more complex with dual PI3K-Akt-mTOR and Ras-Raf-MAPK pathway activation. Rare anaplastic examples may show additional ATRX and/or CDKN2A inactivation
Gene content evolution in the arthropods
Arthropods comprise the largest and most diverse phylum on Earth and play vital roles in nearly every ecosystem. Their diversity stems in part from variations on a conserved body plan, resulting from and recorded in adaptive changes in the genome. Dissection of the genomic record of sequence change enables broad questions regarding genome evolution to be addressed, even across hyper-diverse taxa within arthropods. Using 76 whole genome sequences representing 21 orders spanning more than 500 million years of arthropod evolution, we document changes in gene and protein domain content and provide temporal and phylogenetic context for interpreting these innovations. We identify many novel gene families that arose early in the evolution of arthropods and during the diversification of insects into modern orders. We reveal unexpected variation in patterns of DNA methylation across arthropods and examples of gene family and protein domain evolution coincident with the appearance of notable phenotypic and physiological adaptations such as flight, metamorphosis, sociality, and chemoperception. These analyses demonstrate how large-scale comparative genomics can provide broad new insights into the genotype to phenotype map and generate testable hypotheses about the evolution of animal diversity
âWe Used to Say Rats Fell from the Sky After a Flood:â Temporary Recovery of Muskrat Following Ice Jams in the Peace-Athabasca Delta
Elders and Indigenous land users in the Peace-Athabasca Delta (PAD) have observed a dramatic decline in the relative abundance of muskrat in recent decades (~1935â2014). The main explanation for the decline has been reduction in suitable habitat as a result of decades with reduced frequency of ice-jam flooding on the Peace River. Under favourable conditions, ice jams can cause flooding of perched basins within the PAD that would otherwise receive no recharge from floodwaters. To examine whether abundance of muskrat in the PAD is driven by flooding, we tested the predictions that the density of muskrat (estimated by winter counts of houses) (1) was inversely related to the number of years since major ice jam floods and (2) increased with water depth. An ongoing collaborative monitoring program initiated in 2011, combined with analysis of data from past surveys (1973â2015), allowed Indigenous land users and scientists to document a 10 to 100-fold increase in the density of muskrat houses in 24 basins, over the two years following ice-jam flood events in the PAD. During 1973â2015, in the periods between major floods, density of houses dropped by approximately 79% for every year after a significant flood. In 27 basins surveyed from 2011 to 2015, density of muskrat houses increased by two orders of magnitude in the two years following a flood in the spring of 2014. Density of muskrat houses had a non-linear relationship with estimated depth of water at the time of fall freeze-up; the highest densities of muskrat houses were in basins with about 60 â 250 cm of water at the time of freeze-up. The depth of snow at the time of surveys did not have a strong relationship with the density of muskrat houses. However, few houses were counted in basins with more than 20 cm of snow, likely because deeper snow made it more difficult to conduct surveys and spot houses. Factors other than an increase in the depth of water at fall freeze-up may provide the mechanisms by which flooding affects muskrat. Density of muskrat houses is clearly tied to ice-jam flooding in the PAD. However, the local mechanisms by which floods affect muskrat are best understood by Indigenous land users and remain poorly understood by Western science. Indigenous peoples continue to regard muskrat as an indicator of ecological and cultural health of the PAD. This study highlights the value of consistent ecological monitoring that includes Indigenous knowledge.Les aĂźnĂ©s et les utilisateurs des terres autochtones du delta des riviĂšres de la Paix et Athabasca ont observĂ© une baisse draconienne de lâabondance du rat musquĂ© au cours des derniĂšres dĂ©cennies (~1935-2014). La principale explication du dĂ©clin est la diminution dâabris convenables, et ce, en raison de plusieurs dĂ©cennies marquĂ©es par la frĂ©quence rĂ©duite dâinondations causĂ©es par des embĂącles dans la riviĂšre de la Paix. Dans des conditions favorables, les embĂącles peuvent causer lâinondation des bassins perchĂ©s au sein du delta des riviĂšres de la Paix et Athabasca qui autrement ne recevraient pas de recharge des eaux de crue. Afin dâexaminer si lâabondance du rat musquĂ© dans le delta des riviĂšres de la Paix et Athabasca est favorisĂ©e par les inondations, nous avons testĂ© des prĂ©visions selon lesquelles la densitĂ© du rat musquĂ© (estimĂ©e par le nombre dâabris en hiver) 1) Ă©tait inversement liĂ©e au nombre dâannĂ©es depuis les derniĂšres importantes inondations causĂ©es par des embĂącles et 2) augmentait avec la profondeur de lâeau. Un programme collaboratif de suivi continu lancĂ© en 2011, combinĂ© Ă lâanalyse de donnĂ©es des relevĂ©s antĂ©rieurs (1973-2015), a permis aux utilisateurs des terres autochtones et aux scientifiques de multiplier de 10 Ă 100 fois la densitĂ© dâabris du rat musquĂ© dans 24 bassins, au cours des deux annĂ©es suivant des Ă©vĂ©nementsdâinondation causĂ©s par des embĂącles dans le delta des riviĂšres de la Paix et Athabasca. Entre 1973 et 2015, durant les pĂ©riodes se situant entre les inondations importantes, la densitĂ© dâabris a diminuĂ© dâenviron 79 % chaque annĂ©e suivant une inondation importante. Dans 27 bassins sondĂ©s entre 2011 et 2015, la densitĂ© dâabris du rat musquĂ© a augmentĂ© de deux ordres de grandeur au cours des deux annĂ©es ayant suivi une inondation survenue au printemps de 2014. La densitĂ© dâabris du rat musquĂ© avait une relation non linĂ©aire avec la profondeur de lâeau estimĂ©e au moment de la prise des glaces en automne; les plus fortes densitĂ©s dâabris du rat musquĂ© se trouvaient dans les bassins ayant de 60 Ă 250 cm dâeau au moment de la prise des glaces. La profondeur de la neige au moment des relevĂ©s nâavait pas de relation solide avec la densitĂ© dâabris du rat musquĂ©. Cependant, nous avons comptĂ© peu dâabris dans les bassins comptant plus de 20 cm de neige, probablement parce quâil Ă©tait plus difficile dâeffectuer des relevĂ©s et de trouver les abris dans la neige plus Ă©paisse. Des facteurs autres que lâaugmentation de la profondeur de lâeau au moment de la prise des glaces en automne pourraient fournir les mĂ©canismes par lesquels les inondations se rĂ©percutent sur les rats musquĂ©s. La densitĂ© dâabris du rat musquĂ© est manifestement liĂ©e aux inondations causĂ©es par des embĂącles dans le delta des riviĂšres de la Paix et Athabasca. Toutefois, les utilisateurs des terres autochtones comprennent mieux les mĂ©canismes locaux par lesquels les inondations se rĂ©percutent sur les rats musquĂ©s, tandis quâils demeurent mal compris par la science occidentale. Les peuples autochtones continuent de considĂ©rer le rat musquĂ© comme un indicateur de la santĂ© Ă©cologique et culturelle du delta des riviĂšres de la Paix et Athabasca. Cette Ă©tude fait ressortir la valeur dâun suivi Ă©cologique constant qui tient compte des connaissances autochtones
Enterococcus faecalis demonstrates pathogenicity through increased attachment in an ex vivo polymicrobial pulpal infection
This study investigated the host response to a polymicrobial pulpal infection consisting of Streptococcus anginosus and Enterococcus faecalis, bacteria commonly implicated in dental abscesses and endodontic failure, using a validated ex vivo rat tooth model. Tooth slices were inoculated with planktonic cultures of S. anginosus or E. faecalis alone or in co-culture at ratios of 50:50 and 90:10 S. anginosus to E. faecalis. Attachment was semi-quantified by measuring area covered by fluorescently labelled bacteria. Host response was established by viable histological cell counts and inflammatory response using RT-qPCR and immunohistochemistry. A significant reduction in cell viability was observed for single and polymicrobial infections, with no significant differences between infection types (â2000cells/mm2 for infected pulps compared to â4000cells/mm2 for uninfected pulps). E. faecalis demonstrated significantly higher levels of attachment (6.5%) compared to S. anginosus alone (2.3%) and mixed species infections (3.4% for 50:50 and 2.3% for 90:10), with a remarkable affinity to the pulpal vasculature. Infections with E. faecalis demonstrated the greatest increase in TNF-α (47.1 fold for E. faecalis, 14.6 fold for S. anginosus, 60.1 fold for 50:50 and 25.0 fold for 90:10) and IL-1ÎČ expression (54.8 fold for E. faecalis, 8.8 fold for S. anginosus, 54.5 fold for 50:50 and 39.9 fold for 90:10) when compared to uninfected samples. Immunohistochemistry confirmed this with the majority of inflammation localised to the pulpal vasculature and odontoblast regions. Interestingly, E. faecalis supernatant and heat killed E. faecalis treatment was unable to induce the same inflammatory response, suggesting E. faecalis pathogenicity in pulpitis is linked to its greater ability to attach to the pulpal vasculature
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Recurrent non-canonical histone H3 mutations in spinal cord diffuse gliomas.
2016 Research & Innovation Day Program
A one day showcase of applied research, social innovation, scholarship projects and activities.https://first.fanshawec.ca/cri_cripublications/1003/thumbnail.jp
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