| 2741. |
- Teal, C., et al.
(author)
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Triaxial strongly deformed bands in Tm-160,Tm-161
- 2008
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In: Physical Review C (Nuclear Physics). - 0556-2813. ; 78:1
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Journal article (peer-reviewed)abstract
- High-spin states in Tm-160,Tm-161 were populated using the Te-128(Cl-37, 5n and 4n) reactions at a beam energy of 170 MeV. Emitted gamma rays were detected in the Gammasphere spectrometer. Two rotational bands with high moments of inertia were discovered, one assigned to Tm-160, while the other tentatively assigned to Tm-161. These sequences display features similar to bands observed in neighboring Er, Tm, Yb, and Lu nuclei which have been discussed in terms of triaxial strongly deformed structures. Cranked Nilsson Strutinsky calculations have been performed that predict well-deformed triaxial shapes at high spin in Tm-160,Tm-161.
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| 2742. |
- Thijssen, E. H., et al.
(author)
-
Diagnostic value of plasma phosphorylated tau181 in Alzheimer's disease and frontotemporal lobar degeneration
- 2020
-
In: Nature Medicine. - : Springer Science and Business Media LLC. - 1078-8956 .- 1546-170X. ; 26, s. 387-397
-
Journal article (peer-reviewed)abstract
- Plasma pTau181 concentrations are elevated specifically in patients diagnosed with Alzheimer's disease compared to those diagnosed with frontotemporal lobar degeneration or elderly controls, supporting its further development as a blood-based biomarker for AD. With the potential development of new disease-modifying Alzheimer's disease (AD) therapies, simple, widely available screening tests are needed to identify which individuals, who are experiencing symptoms of cognitive or behavioral decline, should be further evaluated for initiation of treatment. A blood-based test for AD would be a less invasive and less expensive screening tool than the currently approved cerebrospinal fluid or amyloid beta positron emission tomography (PET) diagnostic tests. We examined whether plasma tau phosphorylated at residue 181 (pTau181) could differentiate between clinically diagnosed or autopsy-confirmed AD and frontotemporal lobar degeneration. Plasma pTau181 concentrations were increased by 3.5-fold in AD compared to controls and differentiated AD from both clinically diagnosed (receiver operating characteristic area under the curve of 0.894) and autopsy-confirmed frontotemporal lobar degeneration (area under the curve of 0.878). Plasma pTau181 identified individuals who were amyloid beta-PET-positive regardless of clinical diagnosis and correlated with cortical tau protein deposition measured by F-18-flortaucipir PET. Plasma pTau181 may be useful to screen for tau pathology associated with AD.
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| 2743. |
- Thoram, S., et al.
(author)
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Nature and Origin of Magnetic Lineations Within Valdivia Bank : Ocean Plateau Formation by Complex Seafloor Spreading
- 2023
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In: Geophysical Research Letters. - 0094-8276. ; 50:13
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Journal article (peer-reviewed)abstract
- Valdivia Bank (VB) is a Late Cretaceous oceanic plateau formed by volcanism from the Tristan-Gough hotspot at the Mid-Atlantic Ridge (MAR). To better understand its origin and evolution, magnetic data were used to generate a magnetic anomaly grid, which was inverted to determine crustal magnetization. The magnetization model reveals quasi-linear polarity zones crossing the plateau and following expected MAR paleo-locations, implying formation by seafloor spreading over ∼4 Myr during the formation of anomalies C34n-C33r. Paleomagnetism and biostratigraphy data from International Ocean Discovery Program Expedition 391 confirm the magnetic interpretation. Anomaly C33r is split into two negative bands, likely by a westward ridge jump. One of these negative anomalies coincides with deep rift valleys, indicating their age and mechanism of formation. These findings imply that VB originated by seafloor spreading-type volcanism during a plate reorganization, not from a vertical stack of lava flows as expected for a large volcano.
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| 2744. |
- Tian, Wenlong, et al.
(author)
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mu J-level multi-cycle terahertz generation in a periodically poled Rb:KTP crystal
- 2021
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In: Optics Letters. - : The Optical Society. - 0146-9592 .- 1539-4794. ; 46:4, s. 741-744
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Journal article (peer-reviewed)abstract
- We demonstrate multi-cycle terahertz (MC-THz) generation in a 15.5 mm long periodically poled rubidium (Rb)-doped potassium titanyl phosphate (Rb:PPKTP) crystal with a poling period of 300 mu m. By cryogenically cooling the crystal to 77 K, up to 0.72 mu J terahertz energy is obtained at a frequency of 0.5 THz with a 3 GHz bandwidth. A maximum internal optical-to-terahertz conversion efficiency of 0.16% is achieved, which is comparable with results achieved using periodically poled lithium niobate crystal. Neither photorefractive effects nor damage was observed with up to 900 mJ/cm(2), showing the great potential of Rb:PPKTP for multi-millijoule-level MC-THz generation.
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| 2745. |
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| 2746. |
- Tiegs, Scott D., et al.
(author)
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Global patterns and drivers of ecosystem functioning in rivers and riparian zones
- 2019
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In: Science Advances. - Washington : American Association of Advancement in Science. - 2375-2548. ; 5:1
-
Journal article (peer-reviewed)abstract
- River ecosystems receive and process vast quantities of terrestrial organic carbon, the fate of which depends strongly on microbial activity. Variation in and controls of processing rates, however, are poorly characterized at the global scale. In response, we used a peer-sourced research network and a highly standardized carbon processing assay to conduct a global-scale field experiment in greater than 1000 river and riparian sites. We found that Earth's biomes have distinct carbon processing signatures. Slow processing is evident across latitudes, whereas rapid rates are restricted to lower latitudes. Both the mean rate and variability decline with latitude, suggesting temperature constraints toward the poles and greater roles for other environmental drivers (e.g., nutrient loading) toward the equator. These results and data set the stage for unprecedented "next-generation biomonitoring" by establishing baselines to help quantify environmental impacts to the functioning of ecosystems at a global scale.
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| 2747. |
- Tinyanont, S., et al.
(author)
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Keck Infrared Transient Survey. I. Survey Description and Data Release 1
- 2024
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In: Publications of the Astronomical Society of the Pacific. - 0004-6280 .- 1538-3873. ; 136:1
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Journal article (peer-reviewed)abstract
- We present the Keck Infrared Transient Survey, a NASA Key Strategic Mission Support program to obtain near-infrared (NIR) spectra of astrophysical transients of all types, and its first data release, consisting of 105 NIR spectra of 50 transients. Such a data set is essential as we enter a new era of IR astronomy with the James Webb Space Telescope (JWST) and the upcoming Nancy Grace Roman Space Telescope (Roman). NIR spectral templates will be essential to search JWST images for stellar explosions of the first stars and to plan an effective Roman SN Ia cosmology survey, both key science objectives for mission success. Between 2022 February and 2023 July, we systematically obtained 274 NIR spectra of 146 astronomical transients, representing a significant increase in the number of available NIR spectra in the literature. Here, we describe the first release of data from the 2022A semester. We systematically observed three samples: a flux-limited sample that includes all transients <17 mag in a red optical band (usually ZTF r or ATLAS o bands); a volume-limited sample including all transients within redshift z < 0.01 (D ≈ 50 Mpc); and an SN Ia sample targeting objects at phases and light-curve parameters that had scant existing NIR data in the literature. The flux-limited sample is 39% complete (60% excluding SNe Ia), while the volume-limited sample is 54% complete and is 79% complete to z = 0.005. Transient classes observed include common Type Ia and core-collapse supernovae, tidal disruption events, luminous red novae, and the newly categorized hydrogen-free/helium-poor interacting Type Icn supernovae. We describe our observing procedures and data reduction using PypeIt, which requires minimal human interaction to ensure reproducibility.
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| 2748. |
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| 2749. |
- Toreti, A, et al.
(author)
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Narrowing uncertainties in the effects of elevated CO2 on crops
- 2020
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In: Nature Food. - : Springer Science and Business Media LLC. - 2662-1355. ; 1, s. 775-782
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Journal article (peer-reviewed)abstract
- Plant responses to rising atmospheric carbon dioxide (CO2) concentrations, together with projected variations in temperature and precipitation will determine future agricultural production. Estimates of the impacts of climate change on agriculture provide essential information to design effective adaptation strategies, and develop sustainable food systems. Here, we review the current experimental evidence and crop models on the effects of elevated CO2 concentrations. Recent concerted efforts have narrowed the uncertainties in CO2-induced crop responses so that climate change impact simulations omitting CO2 can now be eliminated. To address remaining knowledge gaps and uncertainties in estimating the effects of elevated CO2 and climate change on crops, future research should expand experiments on more crop species under a wider range of growing conditions, improve the representation of responses to climate extremes in crop models, and simulate additional crop physiological processes related to nutritional quality.
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| 2750. |
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