936 research outputs found

    Geometric Morphometrics of Gary Dart Points from the Davy Crockett National Forest

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    Three-dimensional scans of Gary dart points recovered from the Davy Crockett National Forest are employed in tests of basal morphology by site, size (allometry), and asymmetry. Variability in basal morphology for Gary points from sites on the Davy Crockett National Forest is presented and compared to specimens from the published type books. The hypothesis that Gary basal morphology differs between sites containing Woodland-era sand temped ceramics and those where no sand tempered ceramics were recovered is then tested and the results discussed

    Report on a collecting trip of the British Myriapod Group to Hungary in 1994

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    During a collecting trip participated jointly by the members of the British Myriapod Group and by Hungarian experts in 1994, 34 species of millipedes, 14 of centipedes, 8 of woodlice and 73 of spiders were recorded from Hungary. Two records of the millipede species Boreoiulus tenuis (Bigler, 1913) and Styrioiulus styricus (Verhoeff, 1896) were new to the fauna of Hungary

    Addressing Survey Bias: Maxent Models and Public Archaeology at the Davy Crockett National Forest

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    Over the past 30+ years, compliance-based archaeological projects conducted on the Davy Crockett National Forest have yielded an impressive contribution to the archaeological record. However, those efforts were limited to specific survey areas based upon specific needs. To begin to address survey bias and the impact that it can have on site probability models, a stratified random sample of 50 locations was generated for the forest. In early 2018, a public archaeology (Passport-in-Time) project was used to engage interested volunteers who assisted in testing these sample locations. These results, as well as other new data, were added to the maxent site probability model in advance of running a second iteration. A second call for volunteers in early 2019 will aid with site relocation and delineation of known resources, as well as an additional test using a new stratified random sample

    First Test of Habitat Suitability Models for the Davy Crockett National Forest

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    The test for this suite of models was conducted as a double-blind survey since neither the United States Forest Service personnel (excepting Garcia) nor the participants were provided with any information regarding the model in advance of testing. Input from the model was shared with the crew the day after each location was tested. Enlistment of the double-blind survey method aids in reducing survey bias. Collection of data for this project begins with the stratified random sample. The sample consists of random locations throughout compartments of the Davy Crockett National Forest. Those locations not visited in the first test of the model will be surveyed following the Passport-in-Time project. To test the stratified random sample, a three-by-three grid of nine shovel tests were excavated at each location. Those resources discovered during the survey were assigned a forest-specific number, were documented, and the collections were subsequently transferred to the Center for Regional Heritage Research at Stephen F. Austin State University for analysis and processing

    Experimental and Computational Study of Area and Perimeter Contributions to Radiometer Forces

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    The relative contribution to the radiometric force of the area and perimeter of the vane is studied experimentally and numerically. Experimentally, a circular vane, a low-aspect rectangular vane, and a high-aspect rectangular vane were all tested on a force balance, with nano-Newton resolution, placed in a stagnant gas. The computational results were obtained through 2-D simulations using the direct simulation Monte Carlo method, as well as a discrete ordinate solution of the ES model kinetic equation. Gas pressure was varied from 0.006 to 6 Pa, which was a broad enough range to observe the characteristic peak force production of a radiometer in the transition regime, where the peak occurs at Kn ~ 0.1. It was found that the area of a radiometer vane is responsible for a significant amount ofthe total force production through a wide range of operating pressures. It is only at the highest background pressures, well after force production has peaked, that the vane perimeter appears to dominate the operation of the radiometer

    A golden orb-weaver spider (Araneae: Nephilidae: Nephila) from the Middle Jurassic of China

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    Nephila are large, conspicuous weavers of orb webs composed of golden silk, in tropical and subtropical regions. Nephilids have a sparse fossil record, the oldest described hitherto being Cretaraneus vilaltae from the Cretaceous of Spain. Five species from Neogene Dominican amber and one from the Eocene of Florissant, CO, USA, have been referred to the extant genus Nephila. Here, we report the largest known fossil spider, Nephila jurassica sp. nov., from Middle Jurassic (approx. 165 Ma) strata of Daohugou, Inner Mongolia, China. The new species extends the fossil record of the family by approximately 35 Ma and of the genus Nephila by approximately 130 Ma, making it the longest ranging spider genus known. Nephilidae originated somewhere on Pangaea, possibly the North China block, followed by dispersal almost worldwide before the break-up of the supercontinent later in the Mesozoic. The find suggests that the palaeoclimate was warm and humid at this time. This giant fossil orb-weaver provides evidence of predation on medium to large insects, well known from the Daohugou beds, and would have played an important role in the evolution of these insects

    Historic Image Gallery for the National Forests and Grasslands in Texas

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    Historic images curated at the National Forests and Grasslands in Texas (NFGT) have been digitized and uploaded to the collections of the Center for Regional Heritage Research in the institutional repository of Stephen F. Austin State University. Searchable metadata is included with each image, and metadata can be harvested through the Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH). All images are made available at three resolutions; full, medium, and thumbnail, and are available for download under a Creative Commons Attribution-No Derivative Works 4.0 International License (https://creativecommons.org/licenses/by-nd/4.0/). Data in the collection is compliant with the new European Union General Data Protection Regulation, ensuring compliance with the most recent privacy guidelines

    Microplastics and nanoplastics in haemodialysis waters: Emerging threats to be in our radar

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    Microplastics are present in the environment, in drinking water, in human blood and there is evidence of nanoplastics in tap water. The objective of this work was to analyze the possibility of hemodialysis patients being contaminated by micro and nanoplastics (MNPs) during dialysis treatment. The motivation for this investigation is the fact that hemodialysis patients use about 300–600 L of drinking water per week, which may be contaminated by MNPs. A literature review, a field investigation in a London hospital and an estimation of MNPs intake in patients were carried out. The results showed potential points of risk of contamination of patients by MNPs in hemodialysis. It was also estimated that for a filtration efficiency of 99 % for MNPs, the amount of microplastics that can penetrate the kidneys of patients is 0.0021–3768 particles/week. The assessment concludes that hemodialysis patients are at high risk of MNP contamination

    A case of recurrent epilepsy-associated rosette-forming glioneuronal tumor with anaplastic transformation in the absence of therapy.

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    Rosette-forming glioneuronal tumor (RGNT) most commonly occurs adjacent to the fourth ventricle and therefore rarely presents with epilepsy. Recent reports describe RGNT occurrence in other anatomical locations with considerable morphologic and genetic overlap with the epilepsy-associated dysembryoplastic neuroepithelial tumor (DNET). Examples of RGNT or DNET with anaplastic change are rare, and typically occur in the setting of radiation treatment. We present the case of a 5-year-old girl with seizures, who underwent near total resection of a cystic temporal lobe lesion. Pathology showed morphologic and immunohistochemical features of RGNT, albeit with focally overlapping DNET-like patterns. Resections of residual or recurrent tumor were performed 1 year and 5 years after the initial resection, but no adjuvant radiation or chemotherapy was given. Ten years after the initial resection, surveillance imaging identified new and enhancing nodules, leading to another gross total resection. This specimen showed areas similar to the original tumor, but also high-grade foci with oligodendroglial morphology, increased cellularity, palisading necrosis, microvascular proliferation, and up to 13 mitotic figures per 10 high power fields. Ancillary studies the status by sequencing showed wild-type of the isocitrate dehydrogenase 1 (IDH1), IDH2, and human histone 3.3 (H3F3A) genes, and BRAF studies were negative for mutation or rearrangement. Fluorescence in situ hybridization (FISH) showed codeletion of 1p and 19q limited to the high-grade regions. By immunohistochemistry there was loss of nuclear alpha-thalassemia mental retardation syndrome, X-linked (ATRX) expression only in the high-grade region. Next-generation sequencing showed an fibroblast growth factor receptor receptor 1 (FGFR1) kinase domain internal tandem duplication in three resection specimens. ATRX mutation in the high-grade tumor was confirmed by sequencing which showed a frameshift mutation (p.R1427fs), while the apparent 1p/19q-codeletion by FISH was due to loss of chromosome arm 1p and only partial loss of 19q. Exceptional features of this case include the temporal lobe location, 1p/19q loss by FISH without true whole-arm codeletion, and anaplastic transformation associated with ATRX mutation without radiation or chemotherapy
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