175 research outputs found

    Late Precontact Settlement on the Northern Seward Peninsula Coast: Results of Recent Fieldwork

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    Changing Arctic settlement patterns are associated with shifts in socioeconomic organization and interaction at both the inter- and intraregional levels; analysis of Arctic settlement patterns can inform research on the emergence and spread of Arctic maritime adaptations. Changes in late precontact settlement patterns in Northwest Alaska suggest significant shifts in subsistence and/or social organization, but the patterns themselves are not well understood. Prior research around Kotzebue Sound suggests three possible scenarios: (1) population decrease and dispersion from settlement centers after 550 cal bp, (2) population stability and dispersion after 550 cal bp, and (3) different settlement patterns in the northern and southern areas of Kotzebue Sound. We analyze site distribution and radiocarbon data from new research on the northern Seward Peninsula coast to address questions about local late precontact settlement patterns. Our results point to denser late precontact occupation of this region than previously understood, suggesting either population stability and dispersion after 550 cal bp or the development of differential settlement patterns around the Kotzebue Sound region. This research provides new information about late precontact settlement patterns in Northwest Alaska and contributes to the broader debate about the changing nature of Arctic maritime adaptations during the dynamic late Holocene period. Results also indicate that people in this region were well integrated into both Kotzebue Sound and more distant socioeconomic systems despite potential reduction or change in interaction spheres during the late precontact period

    Cultural Vulnerability and Resilience in the Arctic: Preliminary Report on Archeological Fieldwork at Cape Krusenstern, Northwest Alaska

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    While natural scientists track environmental change in response to global warming, less attention has been directed towards human interface with long term Arctic environmental dynamics. Current research at Cape Krusenstern, Alaska, seeks to address this deficit through investigation of human-environmental interactions recorded in archeological and paleoenvironmental data spanning the last 4,000-5,000 years at the Cape, building on the pioneering work conducted at Krusenstern by J. Louis Giddings and Douglas D. Anderson. Systematic survey and use of new mapping technology to record cultural and natural features are methods central to addressing these research questions. Discovery of new archeological features indicates occupation of the Cape was more extensive over the last 1,000 years than previously thought, although additional fieldwork and analysis are needed

    Using A Field Journal To Enhance Conceptual Understanding

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    Research Question: Is individual experience a significant factor in deepening conceptual understanding? Method: A Field Journal Assignment was given to two classes (1 grad and 1 undergrad) each of three terms over the course of the academic year. Students in each course were provided with a seminal reading which articulated the merits of deepening conceptual understanding by means of analyzing one’s beliefs about a particular concept and one’s reasons for holding those beliefs. (Wilson, J. 1998, “Seriousness and the Foundations of Education”, Educational Theory Vol 48: #2

    Dynamical quantum noise in Bose-Einstein condensates

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    We introduce the study of dynamical quantum noise in Bose-Einstein condensates through numerical simulation of stochastic partial differential equations obtained using phase space representations. We derive evolution equations for a single trapped condensate in both the positive-PP and Wigner representations, and perform simulations to compare the predictions of the two methods. The positive-PP approach is found to be highly susceptible to the stability problems that have been observed in other strongly nonlinear, weakly damped systems. Using the Wigner representation, we examine the evolution of several quantities of interest using from a variety of choices of initial state for the condensate, and compare results to those for single-mode models.Comment: 8 figures, submitted to Phys. Rev.

    Population-Based Correlates of Covid-19 infection: an analysis From the Dfw Covid-19 Prevalence Study

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    BACKGROUND: COVID-19 has resulted in over 1 million deaths in the U.S. as of June 2022, with continued surges after vaccine availability. Information on related attitudes and behaviors are needed to inform public health strategies. We aimed to estimate the prevalence of COVID-19, risk factors of infection, and related attitudes and behaviors in a racially, ethnically, and socioeconomically diverse urban population. METHODS: The DFW COVID-19 Prevalence Study Protocol 1 was conducted from July 2020 to March 2021 on a randomly selected sample of adults aged 18-89 years, living in Dallas or Tarrant Counties, Texas. Participants were asked to complete a 15-minute questionnaire and COVID-19 PCR and antibody testing. COVID-19 prevalence estimates were calculated with survey-weighted data. RESULTS: Of 2969 adults who completed the questionnaire (7.4% weighted response), 1772 (53.9% weighted) completed COVID-19 testing. Overall, 11.5% of adults had evidence of COVID-19 infection, with a higher prevalence among Hispanic and non-Hispanic Black persons, essential workers, those in low-income neighborhoods, and those with lower education attainment compared to their counterparts. We observed differences in attitudes and behaviors by race and ethnicity, with non-Hispanic White persons being less likely to believe in the importance of mask wearing, and racial and ethnic minorities more likely to attend social gatherings. CONCLUSION: Over 10% of an urban population was infected with COVID-19 early during the pandemic. Differences in attitudes and behaviors likely contribute to sociodemographic disparities in COVID-19 prevalence

    Development of 2nd generation aminomethyl spectinomycins that overcome native efflux in Mycobacterium abscessus

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    Mycobacterium abscessus (Mab), a nontuberculous mycobacterial (NTM) species, is an emerging pathogen with high intrinsic drug resistance. Current standard-of-care therapy results in poor outcomes, demonstrating the urgent need to develop effective antimycobacterial regimens. Through synthetic modification of spectinomycin (SPC), we have identified a distinct structural subclass of N-ethylene linked aminomethyl SPCs (eAmSPCs) that are up to 64-fold more potent against Mab over the parent SPC. Mechanism of action and crystallography studies demonstrate that the eAmSPCs display a mode of ribosomal inhibition consistent with SPC. However, they exert their increased antimicrobial activity through enhanced accumulation, largely by circumventing efflux mechanisms. The N-ethylene linkage within this series plays a critical role in avoiding TetV-mediated efflux, as lead eAmSPC 2593 displays a mere fourfold susceptibility improvement against Mab ΔtetV, in contrast to the 64-fold increase for SPC. Even a minor shortening of the linkage by a single carbon, akin to 1st generation AmSPC 1950, results in a substantial increase in MICs and a 16-fold rise in susceptibility against Mab ΔtetV. These shifts suggest that longer linkages might modify the kinetics of drug expulsion by TetV, ultimately shifting the equilibrium towards heightened intracellular concentrations and enhanced antimicrobial efficacy. Furthermore, lead eAmSPCs were also shown to synergize with various classes of anti-Mab antibiotics and retain activity against clinical isolates and other mycobacterial strains. Encouraging pharmacokinetic profiles coupled with robust efficacy in Mab murine infection models suggest that eAmSPCs hold the potential to be developed into treatments for Mab and other NTM infections

    Evidentialism and Moral Encroachment

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    Moral encroachment holds that the epistemic justification of a belief can be affected by moral factors. If the belief might wrong a person or group more evidence is required to justify the belief. Moral encroachment thereby opposes evidentialism, and kindred views, which holds that epistemic justification is determined solely by factors pertaining to evidence and truth. In this essay I explain how beliefs such as ‘that woman is probably an administrative assistant’—based on the evidence that most women employees at the firm are administrative assistants—motivate moral encroachment. I then describe weaknesses of moral encroachment. Finally I explain how we can countenance the moral properties of such beliefs without endorsing moral encroachment, and I argue that the moral status of such beliefs cannot be evaluated independently from the understanding in which they are embedded

    Detection of Heteroplasmic Mitochondrial DNA in Single Mitochondria

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    BACKGROUND: Mitochondrial DNA (mtDNA) genome mutations can lead to energy and respiratory-related disorders like myoclonic epilepsy with ragged red fiber disease (MERRF), mitochondrial myopathy, encephalopathy, lactic acidosis and stroke (MELAS) syndrome, and Leber's hereditary optic neuropathy (LHON). It is not well understood what effect the distribution of mutated mtDNA throughout the mitochondrial matrix has on the development of mitochondrial-based disorders. Insight into this complex sub-cellular heterogeneity may further our understanding of the development of mitochondria-related diseases. METHODOLOGY: This work describes a method for isolating individual mitochondria from single cells and performing molecular analysis on that single mitochondrion's DNA. An optical tweezer extracts a single mitochondrion from a lysed human HL-60 cell. Then a micron-sized femtopipette tip captures the mitochondrion for subsequent analysis. Multiple rounds of conventional DNA amplification and standard sequencing methods enable the detection of a heteroplasmic mixture in the mtDNA from a single mitochondrion. SIGNIFICANCE: Molecular analysis of mtDNA from the individually extracted mitochondrion demonstrates that a heteroplasmy is present in single mitochondria at various ratios consistent with the 50/50 heteroplasmy ratio found in single cells that contain multiple mitochondria

    Whole-genome sequence-based analysis of thyroid function

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    Tiina Paunio on työryhmän UK10K Consortium jäsen.Normal thyroid function is essential for health, but its genetic architecture remains poorly understood. Here, for the heritable thyroid traits thyrotropin (TSH) and free thyroxine (FT4), we analyse whole-genome sequence data from the UK10K project (N = 2,287). Using additional whole-genome sequence and deeply imputed data sets, we report meta-analysis results for common variants (MAF >= 1%) associated with TSH and FT4 (N = 16,335). For TSH, we identify a novel variant in SYN2 (MAF = 23.5%, P = 6.15 x 10(-9)) and a new independent variant in PDE8B (MAF = 10.4%, P = 5.94 x 10(-14)). For FT4, we report a low-frequency variant near B4GALT6/ SLC25A52 (MAF = 3.2%, P = 1.27 x 10(-9)) tagging a rare TTR variant (MAF = 0.4%, P = 2.14 x 10(-11)). All common variants explain >= 20% of the variance in TSH and FT4. Analysis of rare variants (MAFPeer reviewe
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