Multiple sclerosis (MS) is characterized by both acute and chronic intrathecal inflammation. A subset of MS lesions show paramagnetic rims on susceptibility-weighted MRI sequences, reflecting iron ...accumulation in microglia. These para-magnetic rim lesions have been proposed as a marker of compartmentalized smoldering disease. Paramagnetic rim lesions have been shown at 7 T and, more recently, at 3 T. As susceptibility effects are weaker at lower field strength, it remains unclear if paramagnetic rim lesions are visible at 1.5 T.
The purpose of our study was to compare visualization of paramagnetic rim lesions using susceptibility-weighted imaging at 1.5-T and 3-T MRI in patients with MS.
This retrospective study included nine patients (five women, four men; mean age, 46.8 years) with MS who underwent both 1.5-T and 3-T MRI using a comparable susceptibility-weighted angiography (SWAN) sequence from the same manufacturer. Lesions measuring greater than 3 mm were annotated. Two reviewers independently assessed images at each field strength in separate sessions and classified the annotated lesions as isointense, diffusely paramagnetic, or paramagnetic rim lesions. Discrepancies were discussed at consensus sessions including a third reviewer. Agreement was assessed using kappa coefficients.
Based on the 3-T consensus readings, 115 of 140 annotated lesions (82%) were isointense lesions, 16 (11%) were diffusely paramagnetic lesions, and nine (6%) were paramagnetic rim lesions; based on the 1.5-T consensus readings, 115 (82%) were isointense lesions, 14 (10%) were diffusely paramagnetic lesions, and 11 (8%) were para-magnetic rim lesions. The mean lesion diameter was 11.9 mm for paramagnetic rim lesions versus 6.4 mm for diffusely paramagnetic lesions (
= .006) and 7.8 mm for iso-intense lesions (
= .003). Interrater agreement for lesion classification as a paramagnetic rim lesion was substantial at 1.5 T (κ = 0.65) and 3 T (κ = 0.70). Agreement for paramagnetic rim lesions was also substantial between the consensus readings at the two field strengths (κ = 0.79).
We show comparable identification of paramagnetic rim lesions at 1.5-T and 3-T MRI with substantial interrater agreement at both field strengths and substantial consensus agreement between the field strengths.
Paramagnetic rim lesions may be an emerging marker of chronic neuroinflammation in MS. Their visibility at 1.5 T supports the translational potential of paramagnetic rim lesion identification to more widespread clinical settings, where 1.5-T scanners are prevalent.
Magmatic minerals record the pre-eruptive timescales of magma ascent and mixing in crustal reservoirs and conduits. Investigations of the mineral records of magmatic processes are fundamental to our ...understanding of what controls eruption style, as ascent rates and magma mixing processes are well known to control and/or trigger potentially hazardous explosive eruptions. Thus, amphibole reaction rims are often used to infer pre-eruptive magma dynamics, and in particular to estimate magma ascent rates. However, while several experimental studies have investigated amphibole destabilization during decompression, only two investigated thermal destabilization relevant to magma mixing processes. This study examines amphibole decomposition experimentally through isobaric heating of magnesio-hornblende phenocrysts within a natural high-silica andesite glass. The experiments first equilibrated for 24 h at 870 °C and 140 MPa at H2O-saturated conditions and ƒO2 ∼ Re–ReO prior to rapid heating to 880, 900, or 920 °C and hold times of 3–48 h. At 920 °C, rim thicknesses increased from 17 μm after 3 h, to 55 μm after 12 h, and became pseudomorphs after longer durations. At 900 °C, rim thicknesses increased from 7 μm after 3 h, to 80 μm after 24 h, to pseudomorphs after longer durations. At 880 °C, rim thicknesses increased from 7 μm after 3 h, to 18 μm after 36 h, to pseudomorphs after 48 h. Reaction rim microlites vary from 5–16 μm in size, with no systematic relationship between crystal size and the duration or magnitude of heating. Time-averaged rim microlite growth rates decrease steadily with increasing experimental duration (from 3.97×10−7 mms−1 to 3.1 to 3.5×10−8 mms−1). Time-averaged microlite nucleation rates also decrease with increasing experimental duration (from 1.2×103 mm−3s−1 to 5.3 mm−3 s−1). There is no systematic relationship between time-averaged growth or nucleation rates and the magnitude of the heating step. Ortho- and clinopyroxene together constitute 57–90 modal % mineralogy in each reaction rim. At constant temperature, clinopyroxene abundances decrease with increasing experimental duration, from 72 modal % (3 h at 900 °C) to 0% (48 h at 880 °C, and 36 h at 900 and 920 °C). Fe–Ti oxides increase from 6–12 modal % (after 3–6 h) to 26–34 modal % (after 36–48 h). Plagioclase occurs in relatively minor amounts (<1–11 modal %), with anorthite contents that increase from An56 to An88 from 3 to 36 h of heating. Distal glass compositions (>500 μm from reacted amphibole) are consistent with inter-microlite rim glasses (71.3–77.7 wt.% SiO2) within a given experiment and there is a weakly positive correlation between increasing run duration and inter-microlite melt SiO2 (68.9–78.5 wt.%). Our results indicate that experimental heating-induced amphibole reaction rims have thicknesses, textures, and mineralogies consistent with many of the natural reaction rims seen at arc-andesite volcanoes. They are also texturally consistent with experimental decompression reaction rims. On this basis it may be challenging to distinguish between decompression and heating mechanisms in nature.
•Amphibole reaction rims form rapidly (3–48 h) following 10–50 °C of heating.•Reaction rim growth rates increases with increasing temperature.•Rim microlites formed during heating are fine grained (<20 μm).•Rims microlites formed by heating include plagioclase, oxides, and pyroxene.•Unambiguous differentiation between heating and decompression rims is challenging.
Prehrana dojenčkov v antičnem Rimu Stemberger Flegar, Kaja
Keria: Studia Latina et Graeca,
12/2023, Letnik:
25, Številka:
1
Journal Article
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Materino mleko je običajno prva otrokova hrana, vendar dojenje zaradi različnih razlogov ni vedno možno. Že iz prazgodovine so tako izpričane posode, ki so verjetno služile za hranjenje otrok kot ...nadomestek dojenja. Iz rimskodobne Slovenije poznamo nekaj takih najdb, a doslej niso bile prepoznane kot posodice za dojenje. Značilne so po tankih stenah in dodatnem dulcu poleg ustja. Nalogo dojenja je lahko opravljala tudi dojilja, s čimer je povezanih več antičnih mitov, pa tudi posvetilni napisi in upodobitve dojilj v Petovioni. Razprave o prehrani dojenčkov in otrok najdemo tudi v delih antičnih piscev in zdravilcev.
The associated Buchsbaum-Rim multiplicities of a module are a descending sequence of non-negative integers. These invariants of a module are a generalization of the classical Hilbert-Samuel ...multiplicity of an ideal. In this article, we compute the associated Buchsbaum-Rim multiplicity of a direct sum of cyclic modules and give a formula for the second to last positive associated Buchsbaum-Rim multiplicity in terms of the ordinary Buchsbaum-Rim and Hilbert-Samuel multiplicities. This is a natural generalization of a formula given by Kirby and Rees.
•RIM Driven thrusters represent a valid alternative to ducted propellers.•Cavitation and tip vortexes have to be controlled already in the design phase, exploiting the potentialities of the RIM ...configuration.•Traditional design methods may fail with such unconventional geometries and requirements.•Simulation based design optimization tools based on accurate RANS calculations represent a feasible design alternative.
A simulation-based design optimization (SBDO) tool is proposed for the design of rim driven thrusters. The optimization framework consists of a parametric description of the rim blade geometry and a multi-objective optimization algorithm which makes use of the results from high-fidelity RANS calculations to drive the choice towards optimal blade shapes. Maximization of the propulsive efficiency and minimization of cavitation, monitored through the simplest cavitation inception criterion based on the analysis of the non-cavitating pressure distribution over the blade, are the contrasting objectives selected for the design. A constraint on the delivered thrust fixes the functioning condition of the devised propellers. Four distinct design runs, changing the number of blades, from three to six, are considered. The reference performance are those of a ducted propeller operating in a decelerating nozzle which is exactly used in the case of rim configuration. Results of the optimizations prove the flexibility and the reliability of the SBDO framework in dealing with unconventional configurations. A generalized reduction of the risk of cavitation is observed regardless the number of blades; five- and six-bladed propulsors ensure remarkable (about 40%) higher margins with respect to any (leading edge and midchord) cavitating phenomena at the cost only of a slight reduction of efficiency. Also, the structure of the tip vortexes results significantly modified.
Compared with on-road vehicles, emission from ships is one of the least-regulated anthropogenic emission sources and non-negligible source of primary aerosols and gas-phase precursors of PM2.5. The ...Bohai Rim Region in China hosts dozens of large ports, two of which ranked among the top ten ports in the world. To determine the impact of ship emissions on the PM2.5 concentrations over this region, two parts of works have been conducted in this study. First, a detailed ship emission inventory with high spatiotemporal resolution was developed based on Automatic Identification System (AIS) data. Then the WRF/Chem model was applied to modeling the impact of ship emissions by comparing two scenarios: with and without ship emissions. The results indicate that the total estimated ship emissions of SO2, NOX, PM10, PM2.5, CO, HC, and CO2 from Bohai Rim Region in 2014 are 1.9×105, 2.9×105, 2.6×104, 2.4×104, 2.5×104, 1.2×104, and 1.3×107tonnes, respectively. The modeling results indicate that the annual PM2.5 concentrations increased by 5.9% on land areas of Bohai Rim Region (the continent within 115.2°E–124.3°E and 36.1°N–41.6°N) due to ship emissions. The contributions show distinctive seasonal variations of contributions, presenting highest in summer (12.5%) followed by spring (6.9%) and autumn (3.3%), and lowest in winter (0.9%). The contribution reaches up to 10.7% along the shoreline and down to 1.0% 200km inland. After examining the statistics of the modeling results during heavy and non-heavy haze days in July, it was found that 6 out of 9 cities around the Bohai Rim Region were observed with higher contributions from ship emissions during heavy haze days compared with non-heavy haze days. These results indicate that the impacts of ship emissions on the ambient PM2.5 are non-negligible, especially for heavy haze days for most coastal cities in the Bohai Rim Region.
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•Impact of ship emissions on PM2.5 in Bohai Rim Region (BRR) was estimated by WRF/Chem.•Ship emission inventory with high spatiotemporal resolution was developed in the area.•Average contribution of ship emissions to PM2.5 in land areas of BRR was 5.9% in 2014.•The average contributions were 10.7% along the shoreline and down to 1.0% 200km inland.•Ship contributions in most coastal cities were bigger in haze period than other days.
Voltage‐gated calcium (CaV) channels and their regulation by proteins at the synaptic cleft play a critical role in neurotransmission. These interactions fine‐tune the synaptic response through the ...regulation of Ca2+ entry into the presynaptic terminal and trigger the fusion of vesicles filled with neurotransmitters and peptides. Regulation of CaV channel intrinsic properties and their numbers at the active zones shape the timing and strength of synaptic function. Here, we provide an overview of a number of proteins reported to be part of CaV channel nanodomains at the synaptic cleft and the repercussions of these interactions for CaV channel trafficking, tethering at the active zone, and regulation of their biophysical properties. We summarize the current state of knowledge by which CaV channels are regulated at presynaptic sites.
Voltage‐gated calcium channel nanodomains are formed through interactions with a number of different proteins that are involved in diverse functions. From the cytoskeleton to active zone proteins, each interaction has a specific role in neurotransmission. In this review, Gandini and Zamponi summarize current understanding of how calcium channels are trafficked, tethered at the active zone, and the functional implications of these interactions.
•For structural features of turbine cascade, width and inclined angle of rim seal exit geometry are investigated.•The mechanism of first-order and secondary-order cooling, and flow structure inside ...the gap and the passage are presented.•A decrease in the inclined angle benefits the inhibition of the cavity vortex, prevents the gas ingress.•The correlation fitting is constructed to quantify the second-order cooling performance, showing a good fit.
For a turbine blade endwall, the leakage (purge flow) exits through rim seal to prevent hot gas ingress and provide some cooling to the endwall. However, changes in the rim seal geometry will inevitably affect the leakage flow over the endwall. To obtain a clearer and quantitative understanding of the effect of rim seal variation on the cooling performance and flow structure, this paper investigated the effects of width and inclined angle of rim seal exit geometry, as well as the flow structure inside the gap and above the passage. A correlation fitting was constructed using the area-averaged cooling effectiveness to quantify the cooling performance on the suction side. The results indicate that the cooling performance of endwall is not sensitive to changes in width. However, a decrease in the inclined angle benefits the inhibition of the cavity vortex, prevents the gas ingress and improves the cooling performance overthe endwall. The cooling performance of blade suction side is sensitive to the leakage mass flow ratio. As the mass flow rate increases from 0.5 % to 1.0 % and 1.5 %, the area-averaged cooling effectiveness on suction side for original case increases by 44.4 % and 30.7 %. The correlation established for the cooling of suction side shows a good fit, which provide a possible evaluation method for cooling design.
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