Miracle-dz/UniFAR-FTUs huggingface dataset:
Linear and nonlinear Thellier paleointensity behavior of natural minerals

[1] We tested single-domain (SD) and multidomain (MD) theories of the acquisition and thermal demagnetization of thermoremanent magnetization (TRM) and partial TRM (pTRM) in Thellier paleointensity determination, using as samples plagioclase and mafic minerals extracted from Matachewan diabase dikes. Susceptibility, hysteresis, and coercivity data indicate that the plagioclase contains mainly SD grains of magnetite while the mafic minerals (clinopyroxene, biotite, and actinolite) contain mainly MD magnetite. The extracted minerals were used in simulated Thellier experiments with laboratory TRM as a proxy for natural remanent magnetization (NRM). The plagioclase behaved ideally, as predicted by Neel SD theory, giving a linear NRM-pTRM (Arai) plot with positive pTRM checks. The mafic minerals behaved nonideally, with strongly curved Arai plots sagging below the ideal SD line, in accord with observations for MD magnetites and with predictions that in heating to moderate temperatures T, more TRM is lost than can be regained as pTRM, causing convex-down Arai plots. In experiments with pTRM parallel to NRM, all pTRM tail checks were zero, but pTRM checks increasingly deviated from the Arai curve toward the SD line as T increased. However, in repeat Thellier experiments, pTRMs at all T agreed with the original pTRMs. The negative pTRM checks were therefore not due to physicochemical alteration but rather to departure from initial states with different magnetic histories than those of the original pTRMs. The inability of pTRM checks to reliably distinguish between MD behavior and irreversible alteration could lead to overestimates of paleointensity from straight-line fits to the low-T “unaltered” part of the Arai curve or underestimates from fits to high-T data. Alternating field cleaning to 15 mT before each Thellier step made the Arai plot only marginally less curved. Low-temperature demagnetization (LTD, zero-field cycling through the 120 K Verwey transition) hardly changed the curvature of the Arai plot for pTRM parallel to NRM. For pTRM perpendicular to NRM, LTD led to an inflected Arai curve straddling the ideal SD line. Data of either form would not give reliable paleointensity values. No presently available pretreatment renders the paleointensity data of MD grains usable. SD and nearly SD grains which behave ideally in the Thellier experiment remain the only useful recorders of absolute paleointensity.
Broadband and narrowband RF interferometers for lightning observations

Two‐dimensional locations of VHF/UHF radiation sources emitted by lightning discharges are measured by both conventional narrowband and recently developed broadband interferometers during a field campaign in Darwin, Australia. Lightning channel images are recorded by an all sky video camera simultaneously. Observation results are compared with each other to confirm the function of the broadband interferometer. The conclusion of comparisons is that these observations show excellent agreement from the aspects of accuracy in azimuth and elevation. The potential capability of the broadband interferometer is evaluated. Advantages and disadvantages of both interferometers are discussed by introducing 2D mapping for additional flashes. It is shown that the broadband interferometer can locate multiple radiation sources, which propagate simultaneously through branching, in time and space.
Inhibition of NFAT Signaling Restores Microvascular Endothelial Function in Diabetic Mice

Central to the development of diabetic macro- and microvascular disease is endothelial dysfunction, which appears well before any clinical sign but, importantly, is potentially reversible. We previously demonstrated that hyperglycemia activates nuclear factor of activated T cells (NFAT) in conduit and medium-sized resistance arteries and that NFAT blockade abolishes diabetes-driven aggravation of atherosclerosis. In this study, we test whether NFAT plays a role in the development of endothelial dysfunction in diabetes. NFAT-dependent transcriptional activity was elevated in skin microvessels of diabetic Akita (Ins2+/−) mice when compared with nondiabetic littermates. Treatment of diabetic mice with the NFAT blocker A-285222 reduced NFATc3 nuclear accumulation and NFAT-luciferase transcriptional activity in skin microvessels, resulting in improved microvascular function, as assessed by laser Doppler imaging and iontophoresis of acetylcholine and localized heating. This improvement was abolished by pretreatment with the nitric oxide (NO) synthase inhibitor l-NG-nitro-l-arginine methyl ester, while iontophoresis of the NO donor sodium nitroprusside eliminated the observed differences. A-285222 treatment enhanced dermis endothelial NO synthase expression and plasma NO levels of diabetic mice. It also prevented induction of inflammatory cytokines interleukin-6 and osteopontin, lowered plasma endothelin-1 and blood pressure, and improved mouse survival without affecting blood glucose. In vivo inhibition of NFAT may represent a novel therapeutic modality to preserve endothelial function in diabetes.
Impact of marine biogeochemistry on the chemical mixing state and cloud forming ability of nascent sea spray aerosol

The composition and properties of sea spray aerosol, a major component of the atmosphere, are often controlled by marine biological activity; however, the scope of impacts that ocean chemistry has on the ability for sea spray aerosol to act as cloud condensation nuclei (CCN) is not well understood. In this study, we utilize a mesocosm experiment to investigate the impact of marine biogeochemical processes on the composition and mixing state of sea spray aerosol particles with diameters < 0.2 µm produced by controlled breaking waves in a unique ocean‐atmosphere facility. An increase in relative abundance of a distinct, insoluble organic particle type was observed after concentrations of heterotrophic bacteria increased in the seawater, leading to an 86 ± 5% reduction in the hygroscopicity parameter (κ) at 0.2% supersaturation. Aerosol size distributions showed very little change and the submicron organic mass fraction increased by less than 15% throughout the experiment; as such, neither of these typical metrics can explain the observed reduction in hygroscopicity. Predictions of the hygroscopicity parameter that make the common assumption that all particles have the same bulk organic volume fractions lead to overpredictions of CCN concentrations by 25% in these experiments. Importantly, key changes in sea spray aerosol mixing state that ultimately influenced CCN activity were driven by bacteria‐mediated alterations to the organic composition of seawater.
An intermediate nepheloid layer associated with high microbial metabolic rates and denitrification in the northwest Indian Ocean

Extensive optical, physical, chemical, and biochemical measurements made simultaneously in the northwest Indian Ocean reveal the occurrence of an intermediate nepheloid layer (INL) invariably associated with the secondary nitrite maximum. Maxima in particulate protein and the activity of the respiratory electron transport system (ETS) are also found within the INL. Since the INL persists long distances from the continental margin with an offshore intensification, it may not be related to the transport of material resuspended along the continental margin. An apparent correlation of the INL with the previously reported subsurface maximum in bacterial abundance suggests that a local increase in the abundance of bacteria may be responsible for the increased turbidity. Positive correlations of the beam attenuation anomaly with nitrite and nitrate deficit suggest that most of these bacteria may be denitrifiers. The organic carbon demand within the denitrifying layer, computed from the observed ETS activity, appears to be severalfold higher than the sinking carbon fluxes to the denitrifying layer, requiring additional modes of supply of the biodegradable organic matter. It is proposed that a bacterial maximum could be maintained with efficient utilization of the dissolved organic matter within the denitrifying waters.
Severe radiation thyroiditis after radioactive iodine for treatment of Graves’ disease

Radiation thyroiditis resulting from radioactive iodine-131 treatment for Graves’ disease is an uncommon complication. Although a majority of patients are asymptomatic or manifest mild symptoms that can be managed conservatively, published literature describing severe radiation thyroiditis resulting in significant morbidity is lacking. We herein report on six patients with severe radiation thyroiditis that resulted in hospitalisation, including an unusual complication of myopericarditis.
Deuterium‐hydrogen exchange in olivine: Implications for point defects and electrical conductivity

Knowledge about hydrogen self diffusion (DH) is critical for determining mantle hydrogen distribution and understanding point defects. Also, chemical diffusion of hydrogen in olivine, such as redox exchange with polarons (DRedox), depends on DH. In this study deuterium 2H was exchanged into hydrogen 1H saturated single crystals of San Carlos olivine between 750 and 900°C at 2 GPa. We measured and fit the resulting 2H profiles to obtain DH,[100] = 10(−4.9±1.4)*e(−140±30kJ/mol)/(RT) m2/s, which is ∼1 log unit lower than DRedox,[100], with similar activation enthalpy Ha. By comparing these two diffusion coefficients, we estimate the small polaron diffusion coefficient. Additionally, we estimate DH in the [010] and [001] orientations, demonstrating that DH is highly anisotropic in olivine. These DHvalues were used with the Nernst‐Einstein relation to estimate the electrical conductivity by hydrogen in olivine (σH = 101.1*e(−130kJ/mol)/(RT) S/m for 10−2 wt % H2O) that is lower in magnitude than previous measurements. Our results suggest that hydrogen alone cannot account for high electrical conductivity anomalies observed at asthenospheric depths (∼10−2 to ∼10−1 S/m). The maximum anisotropic variation of DH and σHin olivine is ∼2 log units between 750 and 900°C and increases when extrapolated to higher temperature (∼3.3 at 1400°C). Anisotropy observed in the mantle may indicate substantial amounts of hydrogen in olivine with lattice‐preferred orientation.
Monitoring Aseismic Forcing in Fault Zones Using Earthquake Time Series

The dynamics of earthquake occurrences is controlled both by fault in- teraction processes and by long-term, tectonic loading of the faults. In addition, tran- sient loading can be caused by aseismic deformation episodes, for example during crustal fluid migration or slow slip events. These forcing transients are best revealed by geodetic measurements. However, this type of instrumentation is not always avail- able, or is not always sensitive enough to detect significant anomalies. In such cases, one is better off exploiting the seismicity signature of these transients in order to char- acterize them. We here explore different ways to do so. Interearthquake time statistics are found to be prone to damping out fluctuations in forcing rate. A more accurate method is developed by comparing the data with a triggering model that accounts for earthquake interactions. The changes in fault loading rates are then well recovered, both in duration and in intensity.
A laboratory investigation into the seismic velocities of methane gas hydrate‐bearing sand

Remote seismic methods, which measure the compressional wave (P wave) velocity (Vp) and shear wave (S wave) velocity (Vs), can be used to assess the distribution and concentration of marine gas hydrates in situ. However, interpreting seismic data requires an understanding of the seismic properties of hydrate-bearing sediments, which has proved problematic because of difficulties in recovering intact hydrate-bearing sediment samples and in performing valid laboratory tests. Therefore a dedicated gas hydrate resonant column (GHRC) was developed to allow pressure and temperature conditions suitable for hydrate formation to be applied to a specimen with subsequent measurement of both Vp and Vs made at frequencies and strains relevant to marine seismic investigations. Thirteen sand specimens containing differing amounts of evenly dispersed hydrate were tested. The results show a bipartite relationship between velocities and hydrate pore saturation, with a marked transition between 3 and 5% hydrate pore saturation for both Vp and Vs. This suggests that methane hydrate initially cements sand grain contacts then infills the pore space. These results show in detail for the first time, using a resonant column, how hydrate cementation affects elastic wave properties in quartz sand. This information is valuable for validating theoretical models relating seismic wave propagation in marine sediments to hydrate pore saturation.
Late Eocene‐Oligocene Te Kuiti Group at Mount Roskill, Auckland, New Zealand

Abstract A 592 m deep water bore drilled at Mount Roskill in central Auckland, New Zealand, intersected products of the Auckland Volcanic Field (0–12 m), pumiceous sediments of the Tauranga Group (12–23 m), interbedded sandstone and mudstone of the Waitemata Group (23–475 m), and Te Kuiti Group sediments (475–592 m). This first record of Te Kuiti Group in the central Auckland area comprises erosionally truncated Glen Massey Formation beneath the Waitemata Group, a complete section through Mangakotuku Formation, and an incomplete Waikato Coal Measures section. Drilling stopped in Waikato Coal Measures, probably less than 30 m short of Paleozoic or Mesozoic basement. Vitrinite reflectance measurements indicate a lignite rank for coal fragments collected from the coal measures, and suggest a maximum burial depth of c. 800 m. Six Te Kuiti Group samples examined for palynomorphs and foraminifers gave ages ranging from Runangan to early Whaingaroan and show a transition from a predominantly terrestrial late Eoc.
The titanium contents of lunar mare basalts

Abstract— Lunar mare basalt sample data suggest that there is a bimodal distribution of TiO2 concentrations. Using a refined technique for remote determination of TiO2, we find that the maria actually vary continuously from low to high values. The reason for the discrepancy is that the nine lunar sample return missions were not situated near intermediate basalt regions. Moreover, maria with 2–4 wt% TiO2 are most abundant, and abundance decreases with increasing TiO2. Maria surfaces with TiO2 >5 wt% constitute only 20% of the maria. Although impact mixing of basalts with differing Ti concentrations may smear out the distribution and decrease the abundance of high‐Ti basalts, the distribution of basalt Ti contents probably reflects both the relative abundances of ilmenite‐free and ilmenite‐bearing mantle sources. This distribution is consistent with models of the formation of mare source regions as cumulates from the lunar magma ocean.
Potential Sources of Decadal Climate Variability over Southern Africa

AbstractPotential sources of decadal climate variability over southern Africa are examined by conducting in-depth analysis of available datasets and coupled general circulation model (CGCM) experiments. The observational data in recent decades show a bidecadal variability noticeable in the southern African rainfall with its positive phase of peak during 1999/2000. It is found that the rainfall variability is related to anomalous moisture advection from the southwestern Indian Ocean, where the anomalous sea level pressure (SLP) develops. The SLP anomaly is accompanied by anomalous sea surface temperature (SST). Both SLP and SST anomalies slowly propagate eastward from the South Atlantic to the southwestern Indian Ocean. The analysis of mixed layer temperature tendency reveals that the SST anomaly in the southwestern Indian Ocean is mainly due to eastward advection of the SST anomaly by the Antarctic Circumpolar Current. The eastward propagation of SLP and SST anomalies are also confirmed in the 270-yr outp.
Olive yield as a function of soil moisture dynamics

This study introduces a water‐driven crop model aiming to quantitatively link olive yield to climate and soil moisture dynamics using an ecohydrological approach. A mathematical model describing soil moisture, evapotranspiration and assimilation dynamics of olive orchards is developed here. The model is able to explicitly reproduce two different hydroclimatic phases in Mediterranean areas: the well‐watered conditions in which evapotranspiration and assimilation assume their maximum values and the real conditions where the limitations induced by soil moisture availability are taken into account. Annual olive yield is obtained by integrating the carbon assimilation during the growing season, including the effects of vegetation water stress on biomass allocation. This numerical model has been tested on an olive orchard located in Sicily (Italy) obtaining a satisfactory reproduction of historical olive yield data. This model is useful for simulating the influence of soil moisture dynamic on biomass growth, fruit productivity, also in a context of climatic change. Copyright © 2011 John Wiley & Sons, Ltd.
Seismic waves velocities and anisotropy in serpentinized peridotites from xigaze ophiolite: Abundance of serpentine in slow spreading ridge

The effect of serpentinization on seismic wave velocity and anisotropy has been analysed in 6 peridotite samples of the Xigaze ophiolite, having harzburgitic composition and a degree of serpentinization ranging from 3% to 70%. We found: i) P- and S- wave velocities are linearly correlated with serpentine content; ii) anisotropy of P- and S-waves decreases with increasing serpentinization (while in fresh peridotites anisotropy is of the order of 6%, for 70% of serpentinization it drops to 1% for P-waves, and to 2%, for S-waves). Comparison of published laboratory velocity data in oceanic lithologies, like gabbros and dolerites, with serpentinized peridotite data shows the difficulty of distinguishing between gabbros and peridotites having a percentage of serpentine between 10 and 40% by seismic waves velocities only. This comparison suggests that seismic velocity data are consistent with the existence of partialy serpentinized peridotites (up to 40% of serpentinization) in the oceanic crust formed at slow-spreading ridges in accordance with geological observation.
Speciation with gene flow across an elevational gradient in New Guinea kingfishers

The role of environmental gradients in speciation remains contentious. Theory suggests speciation without geographic isolation is plausible if divergent natural selection is strong enough to counteract gene flow, but empirical examples are elusive. Tropical mountains provide strong and temporally stable environmental gradients that can promote local adaptation and population genetic structure. Pairs of closely related species with adjacent but divergent elevational ranges are common in these environments, a pattern that suggests parapatric speciation (i.e. speciation with moderate gene flow), but have rarely been studied in a speciation genomics framework. Here we use genomic data from modern and historical museum specimens to provide evidence for speciation with gene flow across an elevational gradient in a pair of New Guinea kingfishers. We find that the lowland species Syma torotoro and montane species S. megarhyncha form discrete genotypic clusters with bimodal variance in phenotypic traits. Despite this, demographic inference, D-statistics, and phylogenetic networks indicate range-wide gene flow over long time periods, with divergence concentrated in small regions of the genome shaped by positive selection. We propose these data can be explained by a “magic trait” model of ecological speciation where selection on body size also affects mate choice. Our results provide a rare validation of theoretical models of adaptive speciation and are consistent with a strong influence of tropical thermal stability on diversification. We suggest the primary role of selection across elevational gradients is the maintenance of species boundaries in the face of incomplete reproductive isolation, a mechanism for generating high tropical biodiversity.
Numerical simulation of the tidal flow and suspended sediment transport in the Qiantang Estuary

AbstractResults from a numerical modeling study are presented to investigate the tidal elevations, tidal current velocity, bed deformation, and suspended sediment concentration in the Qiantang Estuary, China. The Qiantang Estuary is well-known for its macrotide, which generates a hydrodynamically complex environment. This presents challenges for numerical modelers to accurately simulate the flow field and sediment transport in the region. This paper presents a mathematical model using finite volume method with unstructured mesh to simulate the tide-induced water elevation, current velocity, bed deformation, and suspended sediment transport in the Qiantang Estuary. The parameters in the model were determined using the long-term observed field data of the Qiantang Estuary. The simulated tidal elevations and current velocities agree well with the field observations. The numerical prediction of the bed deformation in 5 months is reasonably compared with the field measurements carried out in the same period. H.
Provenance of North American Phanerozoic sandstones in relation to tectonic setting

Framework modes of terrigenous sandstones reflect derivation from various types of provenance terranes that depend upon plate-tectonic setting. Triangular QFL and QmFLt compositional diagrams for plotting point counts of sandstones can be subdivided into fields that are characteristic of sandstone suites derived from the different kinds of provenance terranes controlled by plate tectonics. Three main classes of provenance are termed “continental blocks,” “magmatic arcs,” and “recycled orogens. ” Sandstone suites from each include three variants, of which the subfields lie within the larger subdivisions. Average modes for sandstone suites can be classified provisionally according to tectonic setting using the subdivided QFL and QmFLt plots. To test the validity of the classification, average modes for 233 Phanerozoic sandstone suites from North America were plotted on the triangular compositional diagrams and accompanying paleotectonic maps. Paired maps and ternary diagrams were prepared for eight different time slices, for each of which the tectonic setting of each major region within the continent remained relatively unchanged. Time slices are unequal in length but are controlled by the timing of major orogenic and rifting events that affected North America during the Phanerozoic. Comparison of the sandstone compositions with inferred tectonic setting through the Phanerozoic indicates that the proposed classification scheme is generally valid and yields satisfactory results when applied on a broad scale. Its application, together with other approaches, in regions of the world where over-all trends of geologic history are less well known could lead to important conclusions about the timing and nature of major tectonic events.