Miracle-dz/UniFAR-FTUs huggingface dataset:
LA‐ICP‐MS depth profiling perspective on cleaning protocols for elemental analyses in planktic foraminifers

Measurements of trace metal ratios in foraminiferal calcite are routinely used to reconstruct paleoceanographic conditions. Analyses using solution‐based inductively coupled plasma mass spectrometry (ICP‐MS) require dissolution of the entire foraminifer shell. The potential exists for contamination from adherent clays, mineralized coatings, and other diagenetic components that confound the biogenic trace metal signal. We present results from a cleaning experiment on fossil specimens of the planktic foraminifer Orbulina universa that were cracked into several shell fragments and subjected to different cleaning protocols. We use laser ablation ICP‐MS (LA‐ICP‐MS) depth profiling to evaluate the effects of reductive, oxidative, and chelating (diethylene‐triamine pentaacetic acid) cleaning protocols on shell Mg/Ca and Ba/Ca ratios. Using the natural pattern of intrashell Mg/Ca heterogeneity exhibited by O. universa, we demonstrate that reductive and oxidative cleaning can dissolve shell calcite from available surfaces, although intrashell Mg/Ca minima and maxima are unaffected. High‐resolution depth profiles can be used to identify areas of heterogeneous intrashell Ba/Ca, which can be excluded from computations of whole‐shell Ba/Ca. The size and density of shell pores plays a major role in the degree of contamination from sedimentary material. We demonstrate an approach for computing whole‐shell Me/Ca ratios from LA‐ICP‐MS depth profiles that accounts for potential contamination and diagenetic overprinting.
Leaf area index estimation of bamboo forest in Fujian province based on IRS P6 LISS 3 imagery

Leaf area index (LAI) is an important surface biophysical parameter as an input to many process-oriented ecosystem models. Much work has been reported in the literature on LAI estimation in boreal forests using remotely sensed imagery. However, few if any explicit LAI retrieval studies on bamboo forests in Asian subtropical monsoon-climate regions based on remote sensing technology have been performed. Our goal is to carry out a comparative study on the LAI estimation methods of bamboo forest in Fujian province, China, based on IRS P6 LISS 3 imagery. Both the traditional empirical–statistical approach and the newly proposed normalized distance (ND) method were employed in this study, and a total of 18 modelling parameters were regressed against ground-based LAI measurements. The results show that simple ratio (SR) is the best predictor for LAI estimation in this study area, with the highest R 2 (coefficient of determination) value of 0.68; modified simple ratio (MSR) and normalized difference vegetation index (NDVI) ranked second and third, respectively. The good performance of these three vegetation indices (VIs) can be explained by the ratioing principle. The overall good modelling performance of the ND method in our study area also indicates it is a promising method.
Situated learning of kitesurfing in university teaching.

This article focuses on learning physical activities on the sea and focuses on windsurfing. We highlight the construction of knowledge by students from the University of Alicante, studying the course called “Learning sea sports” in the natural setting of the Province of Alicante (Spain). To this end, we identified the negotiations and cultural exchanges that took place between the participants for one academic year, while they were improving their skills in the magnificent setting of the Mediterranean Sea. During this learning process we detected a complex structure of didactic and social experiences that make these sea-based activities (kitesurfing) very different from physical activities in the natural environment that are learnt in more traditional contexts.
Changes in Temporal and Spatial Pattern of Road Kills Along the Lusaka-Mongu (M9) Highway, Kafue National Park, Zambia

This study examined the extent to which traffic volume and road kills changed after rehabilitation of the Lusaka—Mongu highway (M9), which traverses the Kafue National Park. It also assessed the impact of the road kills on the wildlife populations in the park. The study revealed that traffic volume increased by 45% after rehabilitation of the M9 road. Consequently, sighting rates of road kills increased by >50%. The majority of the collisions occurred in the late wet season (January–March). These months coincide with dense vegetation cover and rutting season of impala (Aepyceros melampus), the species that was killed most frequently. Reduced visibility because of dense vegetation cover, and pronounced animal activity during the rut inevitably enhanced chances of wildlife colliding with vehicles. With regard to impacts of the road kills on the wildlife populations, the majority (>86%) of the animals involved in the road accidents are the young and subadults. The collisions, therefore, are affecting the reproductive potential of the species affected. To mitigate against the wildlife-vehicle collisions, the study recommends various measures, such as slashing of verges at the appropriate time, use of speed cameras, and educational and public-awareness campaigns.
A statistical study of low latitude F region irregularities at Brazilian longitudinal sector response to geomagnetic storms during post‐sunset hours in solar cycle 23

[1] Effects of intense geomagnetic storms (Dst index < −100) to low latitude F region irregularities in the post-sunset hours are statistically studied by the total electron content (TEC) phase fluctuation observations obtained from the ground-based global positioning system (GPS) receivers in the Brazilian longitude sector during a 7.5-year period of 1 April 1998–31 October 2005. Results show that the low latitude irregularities are significantly suppressed during the main and recovery phases of the intense geomagnetic storms in the months (September–March) that normally have high irregularity activity. In contrast, the post-sunset triggering signatures are pronounced in the low irregularity activity season (April–August) during storms. To further understand the storm-produced behaviors in the low latitude F region irregularity in the post-sunset hours, the relationship between the intensity of GPS phase fluctuations and the occurrence time of the of IMF Bz turnings is examined and discussed.
Systematic Variations in Stress State in the Southern San Joaquin Valley: Inferences Based on Well-Bore Data and Contemporary Seismicity

Analysis of stress-induced well-bore breakouts in 35 wells from 10 production fields in the southern San Joaquin Valley (SSJV) indicates systematic spatial variations in the direction of the maximum horizontal stresses at three different scales. First, the regional northeast-southwest compressional stress direction seen along the western margin of the San Joaquin Valley in the Elk Hills, Kettleman Hills, and Coalinga areas, gradually changes to approximately north-south compression over a distance of 10-20 km in the SSJV. This major excursion in the stress field seen in the Yowlumne, Yowlumne North, Paloma, and Rio Viejo production fields represents an approximately 40° counterclockwise rotation in the direction of the maximum horizontal stress (SHmax). Th s systematic reorientation is consistent with approximately north-south convergence as seen in the local fold axes and reverse faults of Pliocene age and younger. Second, at the extreme southern reaches of the SSJV in the San Emidio, Los Lobos, Pleito, Wheeler Ridge, and North Tejon fields, another systematic, but localized, reorientation in the stress field indicates an abrupt change to an approximately east-northeast--west-southwest compression over a distance of a few kilometers. This latter reorientation of SHmax stress direction, which is inconsistent with the local east-west--trending fold axes and thrust faults, represents a 40-50° clockwise rotation in the stresses; this reorientation appears to be limited to production fields located within the inferred hanging w ll of the White Wolf fault that ruptured during the 1952 Ms 7.8 Kern County earthquake. Inversion of earthquake focal mechanisms of events located below the perturbed stress field indicates approximately north-south compression. The stress drop associated with the 1952 earthquake may have been responsible for rotating the SHmax stress direction from the regional approximately north-south to approximately east-northeast--west-southwest in the southernmost SSJV, implying that the remote horizontal stresses are comparable in magnitude. Finally, localized stress perturbations observed at the scale of a few meters in several wells may reflect local perturbations in the stress field, resulting from slip along small faults penetrated by the borehole. Knowledge of the nonun formity in the SSJV stress field is important for designing development programs for production fields in terms of borehole stability, propagation of hydraulic fractures, and fluid transport properties.
Covariation in subskin‐bulk temperature difference with environmental parameters in the north Indian Ocean

This study aims to explore the dependence of the ocean subskin–bulk temperature difference ΔT (T subskin−T 2.5m) on environmental parameters over the north Indian Ocean. This was possible because of the fortuitous concurrence of two parallel programmes, viz., the Tropical Rainfall Measuring Mission (TRMM) carrying a Microwave Imager (TMI) and the Indian moored buoy programme, over 6 years (1998–2003). The environmental parameters considered in this study are total water vapour (TWV), cloud liquid water content (CLW), sea surface wind speed, bulk temperature (T 2.5m) and T 2.5m−T air temperature difference, consisting of a composite data matrix of more than 3000 sets. The study revealed absence of any perceptible dependence on TWV and CLW. For T 2.5m between 24°C and 28°C, the mean Δ T is a decreasing function of T 2.5m. Data classification indicates that most of the cases of T 2.5m<28°C belong to Bay of Bengal during December to February. For the T 2.5m>28°C, Δ T is very small. Our results on the variation of Δ T with T 2.5m−T air are linear and in opposite phase. The daytime Δ T variation over the north Indian Ocean displays a decreasing trend with increasing wind. The night‐time Δ T pattern, especially over the Bay of Bengal, is found to be very unusual: it remains insensitive to the variations in wind speed, and it is predominantly positive. Diurnal variation of Δ T under wind speed below 6 m s−1 is studied for overall data set as well as for the individual season data set. The low wind cases reproduce onset of warming at 9 h local time and a peak around 15 h local time. The average maximum amplitude of Δ T is more than 0.34°C with a standard deviation of greater than 0.7°C. Diurnal warming during pre‐monsoon (post‐monsoon) is highest (lowest).
Modified Gulf of California model for South Georgia,north Scotia Ridge, and implications for the Rocas Verdes back-arc basin, southern Andes

New field mapping and an integrated trace element and Nd isotopic study have been undertaken on the Jurassic-Cretaceous Larsen Harbour Complex on the island of South Georgia, recognized as a displaced part of the southern Andes ensialic, autochthonous Rocas Verdes marginal basin. Five basalt groups (Groups I-V) are identified from trace element data; initial Nd isotopic compositions suggest that they are derived from only two sources. Magmas produced during early stages of continental lithospheric attenuation (Groups I-III) were derived by varying degrees of partial melting and fractional crystallization from a large ion lithophile element (LILE)-enriched, low-{epsilon}{sub Nd} mantle source relative to normal (N)-type mid-ocean ridge basalt (MORB). Magmas produced during later stages of rifting (Groups IV and V) were, however, derived from a high-{epsilon}{sub Nd} asthenospheric mantle source similar to N-type MORB, unaffected by earlier LILE enrichment. Our data do not occur with previous suggestions that the Larsen Harbour Complex and, by implication, the Rocas Verdes formed in a supra-subduction-zone setting. On the basis of geologic and geochemical evidence, we favor basin formation along an oblique-slip margin akin to that of the Gulf of California.
Holocene volcanic history as recorded in the sulfate stratigraphy of the European Project for Ice Coring in Antarctica Dome C (EDC96) ice core

[1] A detailed history of Holocene volcanism was reconstructed using the sulfate record of the European Project for Ice Coring in Antarctica Dome C (EDC96) ice core. This first complete Holocene volcanic record from an Antarctic core provides a reliable database to compare with long records from Antarctic and Greenland ice cores. A threshold method based on statistical treatment of the lognormal sulfate flux distribution was used to differentiate volcanic sulfate spikes from sulfate background concentrations. Ninety-six eruptions were identified in the EDC96 ice core during the Holocene, with a mean of 7.9 events per millennium. The frequency distribution (events per millennium) showed that the last 2000 years were a period of enhanced volcanic activity. EDC96 volcanic signatures for the last millennium are in good agreement with those recorded in other Antarctic ice cores. For older periods, comparison is in some cases less reliable, mainly because of dating uncertainties. Sulfate depositional fluxes of individual volcanic events vary greatly among the different cores. A volcanic flux normalization (volcanic flux/Tambora flux ratio) was used to evaluate the relative intensity of the same event recorded at different sites in the last millennium. Normalized flux variability for the same event showed the highest value in the 1100–1500 AD period. This pattern could mirror changes in regional transport linked to climatic variations such as slight warming stages in the Southern Hemisphere (Southern Hemisphere Medieval Warming–like period? ).
Perturbative nonlinear feedback forces for optical levitation experiments

Feedback control can be used to generate well-determined nonlinear effective potentials in an optical trap, a goal whose applications may range from non-equilibrium thermodynamics to the generation of non-Gaussian states of mechanical motion. Here, we investigate the action of an effective feedback-generated quartic potential on a levitated nanoparticle within the perturbation regime. The effects of feedback delay are discussed and predictions from the perturbation theory of a Brownian particle subjected to a quartic anharmonicity are experimentally verified.
A remark on randomization of a general function of negative regularity

In the study of partial differential equations (PDEs) with random initial data and singular stochastic PDEs with random forcing, we typically decompose a classically ill-defined solution map into two steps, where, in the first step, we use stochastic analysis to construct various stochastic objects. The simplest kind of such stochastic objects is the Wick powers of a basic stochastic term (namely a random linear solution, a stochastic convolution, or their sum). In the case of randomized initial data of a general function of negative regularity for studying nonlinear wave equations (NLW), we show necessity of imposing additional Fourier-Lebesgue regularity for constructing Wick powers by exhibiting examples of functions slightly outside $L^2(\mathbb T^d)$ such that the associated Wick powers do not exist. This shows that probabilistic well-posedness theory for NLW with general randomized initial data fails in negative Sobolev spaces (even with renormalization). Similar examples also apply to stochastic NLW and stochastic nonlinear heat equations with general white-in-time stochastic forcing, showing necessity of appropriate Fourier-Lebesgue $\gamma$-radonifying regularity in the construction of the Wick powers of the associated stochastic convolution.
High-dimensional robust regression under heavy-tailed data: Asymptotics and Universality

We investigate the high-dimensional properties of robust regression estimators in the presence of heavy-tailed contamination of both the covariates and response functions. In particular, we provide a sharp asymptotic characterisation of M-estimators trained on a family of elliptical covariate and noise data distributions including cases where second and higher moments do not exist. We show that, despite being consistent, the Huber loss with optimally tuned location parameter $\delta$ is suboptimal in the high-dimensional regime in the presence of heavy-tailed noise, highlighting the necessity of further regularisation to achieve optimal performance. This result also uncovers the existence of a curious transition in $\delta$ as a function of the sample complexity and contamination. Moreover, we derive the decay rates for the excess risk of ridge regression. We show that, while it is both optimal and universal for noise distributions with finite second moment, its decay rate can be considerably faster when the covariates' second moment does not exist. Finally, we show that our formulas readily generalise to a richer family of models and data distributions, such as generalised linear estimation with arbitrary convex regularisation trained on mixture models.
Late Quaternary evolution of Riverine Plain paleochannels, southeastern Australia

The Riverine Plain of southeastern Australia is the result of prolonged Cenozoic fluvial activity associated with the Murray River and its major southern tributaries, the Murrumbidgee, Goulburn and Lachlan. Single thread, distributary and anabranching channels and floodplains with associated eolian dunes and lunette-bordered lake basins characterise the uppermost sequences of the Late Quaternary. Following 30 years of detailed mapping and stratigraphic investigation, more recently supported by luminescence dating, the Pels sequential model of prior streams and ancestral rivers on the Riverine Plain was replaced with the Page & Nanson model of alternating migrational and aggradational paleochannels. Despite some sub-catchment variability the emerging picture of climatic and hydrological change since the Last Interglacial shows many common themes that are in accord with findings in other parts of Australia including the Lake Eyre Basin and the coastal rivers of New South Wales. Enhanced fluvial activity is apparent in much of Oxygen Isotope Stage (OIS) 5 between 110 and 80 ka and in OIS 3 from 55 to 25 ka. The intervening OIS 4 represents a definite pause between pluvial episodes with an almost complete absence of luminescence dates from both riverine and lacustrine environments supported by evidence of enhanced dune mobilisation and high Antarctic dust flux. OIS 2 from 24 to 12 ka remains somewhat enigmatic with evidence for intense aridity in the Willandra Lakes and elsewhere at the Last Glacial Maximum apparently contradicted by evidence of higher flows in the Darling and Lachlan Rivers and high water levels at Lakes Tandou, Urana and Cullivel. The question of the persistence of the Lachlan River's connection with the Willandra Lakes at this time remains an unresolved issue in urgent need of further study. Despite uncertainty about the nature of the Last Glacial Maximum, it is now clear that higher stream discharges and lake levels occurred later in OIS 2 from about 20 to 12 ka. Dating evidence shows that the transition to essentially modern river regimes occurred early in the Holocene, but may have been somewhat asynchronous between the various Murray Basin sub-catchments.
anisotropic strips Multi-stability of free spontaneously curved

References ml#ref-list-1 http://rspa.royalsocietypublishing. org/content/468/2138/511.full. ht This article cites 16 articles, 5 of which can be accessed free Subject collections (94 articles) mechanics  (252 articles) applied mathematics  Articles on similar topics can be found in the following collections Email alerting service here the box at the top right-hand corner of the article or click Receive free email alerts when new articles cite this article sign up in
Effects of Diet Fed in Drylot on Subsequent Grazing Performance of Growing Cattle1

Two experiments were conducted to determine the effects of diet and rate of BW gain in drylot before grazing on subsequent grazing performance. In Experiment 1, 154 calves (initial BW ± SE = 181 ± 1.98 kg) were fed bermudagrass (Cynodon dactylon (L.) Pers. ) hay or were program-fed for an ADG of 0.23, 0.57, or 0.91 kg/d. In Experiment 2, 96 calves (initial BW ± SE = 211 ± 1.63 kg) were fed bermudagrass hay with either a dry (DS) or a molasses-based supplement (MBS) or were program-fed a diet containing either a dry (PFD) or molasses- based (PFM) supplement (2 × 2 factorial). Regression analysis of grazing performance during Experiment 1 suggested that pasture ADG was reduced by 0.10 kg for every kilogram increase in gain during the feeding period (P<0.01; r2 = 0.13). During the first 41 d of grazing small grains or tall fescue, calves program fed in drylot gained 0.31 kg/d (P<0.01) or tended (P=0.07) to gain 0.26 kg/d, respectively, more than calves fed hay in drylot. In Experiment 2, during the first 14 d of the grazing period, program-fed calves (PFD and PFM) gained 0.74 kg/d more (P<0.01) than calves fed hay-based diets (DS or MBS), and calves on the MBS and PMBS treatments gained 0.23 kg/d more (P=0.01) than calves on the DS and PFD treatments. Program feeding is an economical alternative to feeding calves hay and supplement, and diet fed in drylot can influence performance of calves adapting to high quality pasture.
Major Element Analysis of the Target Rocks at Meteor Crater, Arizona

We collected ~ 400 rock chips in continuous vertical profile at Meteor Crater, Arizona, representing---from bottom to top--the Coconino, Toroweap, Kaibab, and Moenkopi Formations. These rock chips were subsequently pooled into 23 samples for compositional analysis by X-ray fluorescence methods, each sample reflecting a specific stratigraphic "subsection" 5-10 m thick. In addition, the modal abundance of quartz, dolomite, and calcite was determined for the entire Kaibab Formation at vertical resolutions of 1-2 meters using 57 samples. The purpose of these investigations was to support ongoing compositional analyses of the impact melts and their stratigraphic source depth(s) and other studies at Meteor Crater that depend on the composition of the target rocks. The Coconino Formation comprises the lower half of the crater cavity, from 90 m below the original target surface to the bottom of the crater. It is an exceptionally pure sandstone composed of > 97 wt % SiO2. The Toroweap is only 2 m thick and compositionally similar to Coconino; therefore, it is not a good compositional marker horizon. The Kaibab Formation, ~ 80 m thick, is highly variable in SiO2, MgO, and CaO. On a CO2-free basis, the average Kaibab contains 53 wt % SiO2, 16 wt % MgO, and 26 wt % CaO. X-ray diffraction studies show that the Kaibab Formation at Meteor Crater is dominated by dolomite and quartz, albeit in highly variable proportions; calcite is a minor phase at best. The Kaibab at Meteor Crater is therefore a sandy dolomite rather than a limestone, consistent with pronounced facies changes in the Permian of southeast Arizona over short vertical and horizontal distances. The Moenkopi forms the 12-m-thick cap rock and is a calcareous silt that has the highest AI203 (~ 7.5 wt %) and FeO (~ 4 wt %) concentrations of all target rocks. With several examples, we illustrate how this systematic compositional and modal characterization of the target lithologies may contribute to an understanding of Meteor Crater, such as the depth of its melt zone, and to impact cratering in general, such as the liberation of CO2 from shocked carbonates.