2,735 research outputs found

    Alien Registration- St Pierre, Joseph T. (Van Buren, Aroostook County)

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    https://digitalmaine.com/alien_docs/32406/thumbnail.jp

    On the relative importance of offshelf/onshelf drivers of variability in mCDW inventory on the Amundsen Shelf, Antarctica

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    Ice shelves in the Amundsen Sea (west Antarctica) are melting rapidly and may raise global sea levels substantially over the coming century through reduced buttressing. The high basal melt rates are associated with the presence of warm modified Circumpolar Deep Water (mCDW) that intrudes across the continental shelf and melts the floating portion of the ice sheet from its base near the grounding zone. How much mCDW is present on the continental shelf (its volume inventory) is thus thought to be a key proxy for the year-to-year variability in ice shelf melt rates. Over the past decade, the literature has linked this year-to-year variability to processes acting on the continental shelf (“onshelf”) as well as processes acting offshelf (or at the shelf break), but their relative influence remains unclear. Hydrographic surveys from 2007-2018 in the Dotson-Getz Trough reveal a smooth high/low/high pattern in annual mCDW inventories that could reflect processes acting offshelf, onshelf, or both. In the present work, a regional 3D sea ice-ice shelves-ocean model simulates the period 2006-2022 while using historical reanalysis meteorology but the same oceanic conditions offshelf throughout this period. The simulation effectively evaluates how much of the high/low/high pattern can be reproduced in absence of offshelf variability. Results indicate that the observed pattern is reproduced in the basal melt of Pine Island, Thwaites, Crosson, and Dotson ice shelves. The “low” represents a decrease of as much as ~25 Gt/yr for some of these ice shelves. While the “low” becomes apparent as early as summer 2012 for some ice shelves, the timing of the recovery varies. Ice shelves positioned in the east are the first ones to recover (circa mid-2016) and this recovery extends to Crosson and Dotson ~2 years later, reminiscent of the pathway of mCDW inside the Eastern Trough. The simulation supports the view that dynamical processes acting on the shelf (e.g. local Ekman pumping) can explain a substantial portion of the observed year-to-year variability

    Effects of reduced shoreline erosion on Chesapeake Bay water clarity

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    Shoreline erosion supplies sediments to estuaries and coastal waters, influencing water clarity and primary production. Globally, shoreline erosion sediment inputs are changing with anthropogenic alteration of coastlines in populated regions. Chesapeake Bay, a prime example of such a system where shoreline erosion accounts for a large proportion of sediments entering the estuary, serves here as a case study for investigating the effects of changing sediment inputs on water clarity. Long-term increases in shoreline armoring have contributed to decreased erosional sediment inputs to the estuary, changing the composition of suspended particles in surface waters. This study examined the impact of shoreline erosion on water clarity using a coupled hydrodynamic-biogeochemical model. Experiments were conducted to simulate realistic shoreline conditions representative of the early 2000s, increased shoreline erosion, and highly armored shorelines. Together, reduced shoreline erosion and the corresponding reduced rates of resuspension result in decreased concentrations of inorganic particles, improving water clarity particularly in the lower Bay and in dry years where/when riverine sediment influence is low. This clarity improvement relaxed light limitation, which increased organic matter production. Differences between the two extreme experiments revealed that in the mid-estuary in February-April, surface inorganic suspended sediment concentrations decreased 3-7 mg L-1, while organic suspended solids increased 1-3 mg L-1. The resulting increase in the organic-to-inorganic ratio often had opposite effects on clarity according to different metrics, improving clarity in mid-Bay central channel waters in terms of light attenuation depth, but simultaneously degrading clarity in terms of Secchi depth because the resulting increase in organic suspended solids decreased the water’s transparency. This incongruous water clarity effect, the spatial extent of which is defined here as an Organic Fog Zone, was present in February-April in all years studied, but occurred farther south in wet years

    Di[2,6-bis(5-phenylpyrazol-3-yl)pyridine]Co(II): an old coordination mode fora novel supramolecular assembly

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    CoCl2 was treated with 1, 2, and 6 eq. of 2,6-bis(5-phenylpyrazol-3-yl)pyridine (H2L) yielding respectively the monosubstituted [Co(H2L)Cl2], the disubstituted [Co(H2L)2][PF6]2, and a supramolecular assembly formed by a central disubstituted octahedral complex and four more hydrogen bonded peripheral ligands, [{Co(H2L)2}(H2L)4][PF6]2, as illustrated by X-ray crystal structure analysis

    High-throughput molecular imaging via deep-learning-enabled Raman spectroscopy.

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    Raman spectroscopy enables nondestructive, label-free imaging with unprecedented molecular contrast, but is limited by slow data acquisition, largely preventing high-throughput imaging applications. Here, we present a comprehensive framework for higher-throughput molecular imaging via deep-learning-enabled Raman spectroscopy, termed DeepeR, trained on a large data set of hyperspectral Raman images, with over 1.5 million spectra (400 h of acquisition) in total. We first perform denoising and reconstruction of low signal-to-noise ratio Raman molecular signatures via deep learning, with a 10× improvement in the mean-squared error over common Raman filtering methods. Next, we develop a neural network for robust 2-4× spatial super-resolution of hyperspectral Raman images that preserve molecular cellular information. Combining these approaches, we achieve Raman imaging speed-ups of up to 40-90×, enabling good-quality cellular imaging with a high-resolution, high signal-to-noise ratio in under 1 min. We further demonstrate Raman imaging speed-up of 160×, useful for lower resolution imaging applications such as the rapid screening of large areas or for spectral pathology. Finally, transfer learning is applied to extend DeepeR from cell to tissue-scale imaging. DeepeR provides a foundation that will enable a host of higher-throughput Raman spectroscopy and molecular imaging applications across biomedicine

    Nitrogen reductions have decreased hypoxia in the Chesapeake Bay: Evidence from empirical and numerical modeling

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    Seasonal hypoxia is a characteristic feature of the Chesapeake Bay due to anthropogenic nutrient input from agriculture and urbanization throughout the watershed. Although coordinated management efforts since 1985 have reduced nutrient inputs to the Bay, oxygen concentrations at depth in the summer still frequently fail to meet water quality standards that have been set to protect critical estuarine living resources. To quantify the impact of watershed nitrogen reductions on Bay hypoxia during a recent period including both average discharge and extremely wet years (2016–2019), this study employed both statistical and three-dimensional (3-D) numerical modeling analyses. Numerical model results suggest that if the nitrogen reductions since 1985 had not occurred, annual hypoxic volumes (O2 \u3c 3 mg L−1) would have been ~50–120% greater during the average discharge years of 2016–2017 and ~20–50% greater during the wet years of 2018–2019. The effect was even greater for O2 \u3c 1 mg L−1, where annual volumes would have been ~80–280% greater in 2016–2017 and ~30–100% greater in 2018–2019. These results were supported by statistical analysis of empirical data, though the magnitude of improvement due to nitrogen reductions was greater in the numerical modeling results than in the statistical analysis. This discrepancy is largely accounted for by warming in the Bay that has exacerbated hypoxia and offset roughly 6–34% of the improvement from nitrogen reductions. Although these results may reassure policymakers and stakeholders that their efforts to reduce hypoxia have improved ecosystem health in the Bay, they also indicate that greater reductions are needed to counteract the ever-increasing impacts of climate change

    Biocurators and Biocuration: surveying the 21st century challenges

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    Curated databases are an integral part of the tool set that researchers use on a daily basis for their work. For most users, however, how databases are maintained, and by whom, is rather obscure. The International Society for Biocuration (ISB) represents biocurators, software engineers, developers and researchers with an interest in biocuration. Its goals include fostering communication between biocurators, promoting and describing their work, and highlighting the added value of biocuration to the world. The ISB recently conducted a survey of biocurators to better understand their educational and scientific backgrounds, their motivations for choosing a curatorial job and their career goals. The results are reported here. From the responses received, it is evident that biocuration is performed by highly trained scientists and perceived to be a stimulating career, offering both intellectual challenges and the satisfaction of performing work essential to the modern scientific community. It is also apparent that the ISB has at least a dual role to play to facilitate biocurators’ work: (i) to promote biocuration as a career within the greater scientific community; (ii) to aid the development of resources for biomedical research through promotion of nomenclature and data-sharing standards that will allow interconnection of biological databases and better exploit the pivotal contributions that biocurators are making

    Neutron to proton ratios of quasiprojectile and midrapidity emission in the 64^{64}Zn + 64^{64}Zn reaction at 45 MeV/nucleon

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    Simultaneous measurement of both neutrons and charged particles emitted in the reaction 64^{64}Zn + 64^{64}Zn at 45 MeV/nucleon allows comparison of the neutron to proton ratio at midrapidity with that at projectile rapidity. The evolution of N/Z in both rapidity regimes with increasing centrality is examined. For the completely re-constructed midrapidity material one finds that the neutron-to-proton ratio is above that of the overall 64^{64}Zn + 64^{64}Zn system. In contrast, the re-constructed ratio for the quasiprojectile is below that of the overall system. This difference provides the most complete evidence to date of neutron enrichment of midrapidity nuclear matter at the expense of the quasiprojectile

    Identification of pannexin 1-regulated genes, interactome, and pathways in rhabdomyosarcoma and its tumor inhibitory interaction with AHNAK

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    Rhabdomyosarcoma (RMS), the most common soft tissue sarcoma in children, is an aggressive cancer with a poor prognosis. Despite current management, the 5-year survival rate for patients with metastatic RMS is ∌30%; underscoring the need to develop better treatment strategies. We have recently reported that pannexin 1 (PANX1) levels are downregulated in RMS and that restoring its expression inhibits RMS progression. Here, we have surveyed and characterized the molecular changes induced by PANX1 re-expression in RMS. We cataloged transcriptomic changes in this context by RNA sequencing. At the protein level, we unveiled PANX1 interactors using BioID, complemented by co-immunoprecipitation coupled to high-performance liquid chromatography/electrospray ionization tandem mass spectrometry performed in PANX1-enriched fractions. Using these data, we generated searchable public databases for the PANX1 interactome and changes to the RMS transcriptome occurring when PANX1 expression is restored. STRING network analyses revealed a PANX1 interactome involving plasma membrane and cytoskeleton-associated proteins including the previously undescribed interactor AHNAK. Indeed, AHNAK knockdown abrogated the PANX1-mediated reduction in RMS cell viability and migration. Using these unbiased approaches, we bring insight to the mechanisms by which PANX1 inhibits RMS progression, identifying the cell migration protein AHNAK as a key modifier of PANX1-mediated changes in RMS malignant properties

    Identification of pannexin 1-regulated genes, interactome, and pathways in rhabdomyosarcoma and its tumor inhibitory interaction with AHNAK

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    Rhabdomyosarcoma (RMS), the most common soft tissue sarcoma in children, is an aggressive cancer with a poor prognosis. Despite current management, the 5-year survival rate for patients with metastatic RMS is ∌30%; underscoring the need to develop better treatment strategies. We have recently reported that pannexin 1 (PANX1) levels are downregulated in RMS and that restoring its expression inhibits RMS progression. Here, we have surveyed and characterized the molecular changes induced by PANX1 re-expression in RMS. We cataloged transcriptomic changes in this context by RNA sequencing. At the protein level, we unveiled PANX1 interactors using BioID, complemented by co-immunoprecipitation coupled to high-performance liquid chromatography/electrospray ionization tandem mass spectrometry performed in PANX1-enriched fractions. Using these data, we generated searchable public databases for the PANX1 interactome and changes to the RMS transcriptome occurring when PANX1 expression is restored. STRING network analyses revealed a PANX1 interactome involving plasma membrane and cytoskeleton-associated proteins including the previously undescribed interactor AHNAK. Indeed, AHNAK knockdown abrogated the PANX1-mediated reduction in RMS cell viability and migration. Using these unbiased approaches, we bring insight to the mechanisms by which PANX1 inhibits RMS progression, identifying the cell migration protein AHNAK as a key modifier of PANX1-mediated changes in RMS malignant properties
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