Miracle-dz/UniFAR-FTUs huggingface dataset:
Air–Sea Interaction in the Equatorial Atlantic Region

Abstract Using a dynamically motivated analysis of observations, and an intermediate-level coupled model, the interannual variability within the equatorial Atlantic is studied. It is found that a significant part of the observed variability can be described by an equatorial coupled mode akin to ENSO (El Nino–Southern Oscillation). The Atlantic mode signature is even more tightly focused on the equator and is situated proportionally farther to the west within the basin than its Pacific counterpart. Model simulations capture the equatorial coupled mode in relatively pure form and, for what are thought to be the most realistic parameter choices, show interannual oscillations favoring a 4-year period, which are not self-sustaining. The simulated spatial patterns agree well with those extracted from observations, including those features that distinguish the Atlantic from the Pacific. Sensitivity experiments show that the Atlantic coupled-mode signal is less robust than the corresponding Pacific ENSO signal bu.
Efecto de la aclimatación precoz sobre la termotolerancia en pollos de engorde sometidos a un estrés térmico tardío en condiciones de clima tropical

The early-age acclimation was evaluated as a technique lo generate resistance lo heat stress under real tropical conditions. Two groups of 120 five-days-age chickens were exposed during 24 hours at 36 ± 2° C (acclimatized group) or at 30 ± 1° C (no acclimatized group), respectively. After this treatment, both groups were divided in 12 groups of 10 chickens each one. Fed intake, gain of weight, body temperature, body composition and the behavior were measured. The day 40 of age, the temperature was rose up lo 36° C lo produce a heat stress and then besides the previous parameters it was measured the number of animals that hyperventilate and also the breathing rate. The early-age acclimation did not change the performance neither the body composition of broilers. The body temperature of the acclimatized chickens was lower (P < 0.001) than those no acclimatized (41.41 ± 0.47°C vs 41.52 ± 0.43°C) in a consistent way through the time. During the acclimation treatment, the acclimatized chickens decreased their presence lo the feeder but increased those lo the drinker. This behavior was not showed during late heat stress. The number of animals that hyperventilate and breathing rate rose during late heat stress for both treatments, however breathing rate increased more rapidly in the acclimatized chickens. The earlyage acclimation increased the resistance lo heat stress, reducing the mortality rate by about 50%.
Enhanced particle scavenging in deep water of the Aleutian Basin revealed by 210Po‐210Pb disequilibria

The high sedimentation rate but low primary production in surface ocean raised a question whether particles from local upper water column could support high deposition in the Aleutian Basin. Here we first present large 210Po-210Pb disequilibria in deep water of the Aleutian Basin. Dissolved 210Po and 210Pb were depleted relative to 210Pb and 226Ra, respectively, in deep water below 1000 m, as well as decreased with depth, suggesting enhanced particle scavenging in the deep water. The 210Po residence times (1–2 a) in deep water were comparable to those in the upper water column, indicating that 210Po scavenging rates were high in deep water of the Aleutian Basin. The export fluxes of 210Po from the upper 100 m were estimated to be 0.2–0.8 Bq/m2/d, much lower than those in the deep water (7–8 Bq/m2/d). Similarly, POC export fluxes in deep water (24–80 mmolC/m2/d) were higher than those in the upper 100 m (∼1 mmolC/m2/d). Such a large discrepancy between the upper and deep water suggested that particles from local upper water column could not totally meet the enhanced scavenging in the deep water. Based on mass balance calculations, the extra fluxes of 210Pb and POC imported to deep water were estimated to be 8–12 Bq/m2/d and 22–79 mmolC/m2/d, respectively. The ratio of POC to particulate 210Pb (i.e., POC/PPb) in the extra source was estimated to be 6.5 mmol/Bq, which was lower than that in the Bering Shelf with a mean POC/PPb ratio of 10.9 mmol/Bq, implying that particles in the Bering Shelf could be a potential source for the enhanced particle scavenging in deep water of the Aleutian Basin. However, quantitative and detailed role of ridges and manganese from sediments in particle scavenging in the deep water was unclear, and further studies are necessary.
Charge transfer during multiple large ice crystal interactions with a riming target

Laboratory studies of charge transfer between ice crystals and riming soft hailstones (graupel) have been extended using ice crystals of several hundred micrometers in diameter. The sign of the charge transfer is affected by cloud water content and temperature, being positive to soft hailstones at temperatures higher than about −18°C with typical values of cloud liquid water content. The d4 dependence of charge transfer on crystal size reported previously for smaller ice crystals decreases with larger crystals. The new data can be included in numerical models of thunderstorm electrification.
Thermal regime of the NW shelf of the Gulf of Mexico. Part A: Thermal and pressure fields

The thermal field of the Gulf of Mexico (GoM) is analyzed from a comprehensive temperature-depth database of about 8500 bottom hole temperatures and reservoir temperatures. Our stochastic analysis reveals a widespread, systematic sharp thermal gradient increase between 2500 and 4000 m. The analysis of the pressure regime indicates a systematic correlation between the pressure and temperature fields.
An entrainment model for non‐uniform sediment

A model was developed for the prediction of the entrainment rate of non‐uniform sediment considering the movement of bedforms. Laboratory experiments were conducted to advance the formulations of the proposed model and to validate and estimate the model parameters. The model parameters were related to the hydraulic conditions of the flow and the properties of the sediment mixtures using dimensional analysis and gene expression programming. The model incorporated four parameters on its formulation, namely the Shields stress and critical Shields stress to describe the hydraulic and sediment conditions of the flow, the Kramer coefficient of uniformity to describe the grain size distribution of a particular sediment mixture, and the relative position of a particular grain size fraction to the geometric mean to describe the entrainment rate of that fraction within the sediment mixture. The proposed model provided satisfactorily predictions with a deviation less than 25% between the measured and predicted values for most of the fractions, which confirms the validity of the proposed approach and model in predicting of the entrainment rates of various fractions. The model predictions were also compared with other models available for the prediction of the entrainment rate of non‐uniform sediment. The model predictions were within the same order of magnitude of the other models’ predictions. Copyright © 2015 John Wiley & Sons, Ltd.
Trends in Prevalence , Awareness , Management , and Control of Hypertension Among United States Adults , 1999 to 2010

Methods The study used regression models to assess the trends in hypertension prevalence, awareness, management, and control from 1999 to 2010 among 28,995 male and female adults with BP measurements from a nationally representative sample of the noninstitutionalized U.S. population (National Health and Nutrition Examination Survey [NHANES] 1999 to 2010), with special attention given to 5,764 participants in NHANES 2009 to 2010.
Material characterisation of nanowires with intrinsic stress

When fabricating nanowires (NWs) in a doubly-clamped beam configuration it is possible for a residual axial stress to be generated. Here, we show that material characterisation of metal and semiconductor NWs subjected to residual axial stress can be problematic. Benchmark measurements of the Young’s modulus of NWs are performed by sectioning a doubly-clamped NW into two cantilevered wires, eliminating residual axial stress. Use of models for doubly-clamped beams that incorporate the effects of residual stress are found to lead to ambiguity in the extracted Young’s modulus as a function of displacement fit range, even for NWs with no residual stress. This is due to coupling of bending and axial stress effects at small displacements, and the limited displacement range of force curves prior to fracture or plastic deformation. This study highlights the importance of fabricating metal and semiconductor NWs that exhibit little or no residual axial stress for materials characterisation.
Carotid intima-media thickness is associated with incidence of hospitalized atrial fibrillation

Objective Carotid intima-media thickness (IMT) is a measure of arterial thickening and a risk predictor for myocardial infarction and stroke. It is unclear whether IMT also predicts atrial fibrillation (AF). We explored the association between IMT and incidence of first AF hospitalization in a population-based cohort.
Forecasting U.S. hurricanes 6 months in advance

Katrina is a grim reminder of the serious social and economic threat that hurricanes pose to the United States. Recent advances in hurricane climate science provide skillful forecasts of the U.S. hurricane threat at (or near) the start of the season. Predictions of hurricane landfalls at longer lead times (forecast horizons) for the complete hurricane season would greatly benefit risk managers and others interested in acting on these forecasts. Here we show a model that provides a 6‐month forecast horizon for annual hurricane counts along the U.S. coastline during the June through November hurricane season using the North Atlantic Oscillation (NAO) and Atlantic sea‐surface temperature (SST) as predictors. Forecast skill exceeds that of climatology. The long‐lead skill is linked to the persistence of Atlantic SST and to teleconnections between North Atlantic sea‐level pressures and precipitation variability over North America and Europe. The model is developed using Bayesian regression and therefore incorporates the full set of Atlantic hurricane data extending back to 1851.
Dinantian sedimentation and the basement structure of the Derbyshire Dome

The depositional history of the Dinantian on the Derbyshire Dome can be divided into three phases: (1) pre-Holkerian: onlap of an irregular basement surface by evaporite and carbonate sediments, (2) Holkerian to Asbian: sedimentation on a carbonate shelf formed by the merging of early Dinantian depocentres following burial of the basement topography, and (3) Brigantian: formation of intrashelf basins and the development of a carbonate ramp on part of the pre-existing shelf. A model of the basement structure underlying the Derbyshire Dome is presented to explain the location of the Brigantian intrashelf basins and carbonate ramp. The basement consists of two main tilted fault blocks separated by a smaller tilt block. Movement on faults bounding the tilt blocks caused the development of intrashelf basins. The basin margins were controlled by structures which developed in the cover sediments. The carbonate ramp present during the late Brigantian developed in response to an eastward tilting of the basement.
How does the initial configuration of oceanic ridge segments affect their interaction? Insights from analogue models

[1] Oceanic ridge segments interact forming different types of structures, of which transform faults and overlapping spreading centers represent the most common end-members. This study uses analogue models for testing the role of the initial configuration of the ridges on the geometry and kinematics of the resulting interaction zones. The models, run in a centrifuge, consist of a lighter silicone (LDS), rising within a denser silicone (HDS) below a brittle layer simulating the oceanic lithosphere. Precut fractures in the brittle layer simulate the initial configuration of oceanic ridges. The rise and lateral spreading of the LDS induce the propagation, widening, interaction, and linkage of the fractures. We varied the offset and overlap between the fractures, obtaining 10 distinctive types of interaction. Variations in fracture overlap and offset define several interaction types. Increase of fracture overlap leads to interaction zones of lower aspect ratio, with fractures propagating at lower angles to the mean extension direction. Increase of offset leads to the elongation of the interaction zones with the new fractures propagating subparallel to the extension direction. The comparison with several examples of natural ridges shows close geometric similarities, confirming the existence of predominant types of ridge interaction. Among these, ridges with smaller offsets develop interactions similar to overlapping spreading centers, whereas ridges with larger offsets have geometries reminiscent of transform zones. The comparison between experimental and natural examples suggests that the observed wide spectrum of ridge interaction types in nature results from the initial configuration of the divergent plate boundary.
Emissions of CO2, CO, and hydrocarbons from fires in diverse African savanna ecosystems

Emissions of CO2, CO, and hydrocarbons from 13 savanna fires (∼7 ha) were investigated in Zambia and South Africa in August and September 1992. The experiments were conducted at two moist woodland savanna sites, a moist grassland savanna site, and a semiarid woodland savanna site in Zambia, and nine semiarid woodland savanna sites in South Africa. The hydrocarbons measured were CH4, C2–C6 alkanes, alkenes, and alkynes, and aromatic compounds. The linear relationship between the emission factor of CH4 and the combustion efficiency is similar regardless of the phase of combustion (flaming or smoldering), the climatic zone, the herbaceous species, or the amount of aboveground biomass. Concentrations of emitted nonmethane hydrocarbons are linearly correlated with those of CH4. The emission ratio of a trace gas to CH4 is constant for either phase of combustion in these ecosystems. Biomass burning in African savannas is a significant source of CO, ethyne, propene, and benzene in the atmosphere. The amount of CO, ethene, ethane, ethyne, propene, propane, and benzene emitted per year from these fires is about 20–95% of the amount released from global industrial activities.
Modeling long-term soil losses on agricultural fields due to ephemeral gully erosion

It is now recognized worldwide that soil erosion on agricultural fields due to ephemeral gullies may be greater than those losses attributed to sheet and rill erosion processes. Yet it is not known whether the common practice of repairing or obliterating these gullies during annual tillage activities exacerbates or mitigates soil losses over long time periods. Here, a numerical model is used to demonstrate the potential effects of annual tillage on cumulative soil losses from four geographic regions plagued by ephemeral gullies as compared to no-till conditions where the gullies are free to grow and evolve over time and space. Historical precipitation data and field measurements were compiled for specific sites in Belgium, Mississippi, Iowa, and Georgia, and the model simulated ephemeral gully development and evolution during the growing seasons over a continuous 10-year period. When agricultural fields are not tilled annually, the simulations suggest that gullies attain their maximum dimensions during the first few years in response to several relatively large runoff events. During subsequent runoff events, the gullies no longer erode their channels significantly, and soil losses due to gully erosion decrease markedly. When agricultural fields are tilled annually, the ephemeral gully channels are reactivated, thus causing significant soil losses each year in response to runoff events. Over the 10-year simulation, the modeling results suggest that erosion rates in these four geographic regions can be 250% to 450% greater when gullies are tilled and reactivated annually as opposed to the no-till condition. These results reveal that routine filling of ephemeral gully channels during tillage practices may result in markedly higher rates of soil loss as compared to allowing these gullies to persist on the landscape, demonstrating a further advantage of adopting no-till management practices.
Tropospheric Biennial Oscillation (TBO) indistinguishable from white noise

Previous studies proposed that the year‐to‐year variability of seasonal monsoon indices is partly determined by a Tropospheric Biennial Oscillation (TBO). Invoking coupled ocean‐atmosphere‐land processes and the presence of an annual memory, the TBO mechanism describes how a relatively strong monsoon is followed by a year with weaker monsoon and vice versa. Here we revisit the issue of preferred biennial timescales in tropical monsoon systems, by testing the biennial tendencies in observed and simulated monsoon indices against the white noise null hypothesis. According to an analytical expression for the null hypothesis, we expect the probability for this biennial tendency to be 2/3, which is in close agreement with observations, reanalysis products, and Atmospheric Model Intercomparison Project/Coupled Model Intercomparison Project general circulation model simulations. Thus, it is concluded that biennial tendencies in these monsoon indices and the associated TBO are fully consistent with a white noise process and do not require the presence of a preferred biennial timescale.
Tracks and Substrate Reworking by Terrestrial Vertebrates in Quaternary Sediments of Kenya

ABSTRACT Reworking of sedimentary substrates by terrestrial vertebrates, especially hoofed herbivores, has stratigraphic significance comparable to the bioturbation of marine sediments by benthic invertebrates. Environmental analysis of the Pliocene-Pleistocene Koobi Fora Formation in northern Kenya reveals many vertebrate footprints and trackways in fluvial and lake-margin strata. Some beds are completely reworked by trampling of many animals, presumably ungulates, with subsequent disarrangement of primary grain fabric and sedimentary structures. Examination of tracks and game trails in similar modern Kenyan environments, and comparison with those in older sediments, indicate characteristics useful for their recognition elsewhere. Preservation is best in mud and sand interbeds of medium thickness where the animal foot punches out a plug of coherent surface sediment (usually mud) and presses it into underlying units of contrasting lithology (usually sand). Thicker and less coherent muds simply mold the foot. In both situations the track is flat to concave upward with a discontinuous rim that surrounds a low spot where later wind- or water-laid sediments and bone fragments may concentrate. Trampling of coherent surface mud disturbs the ground surface allowing wind and water to remove the loose sand below. thereby creating shallow erosional depressions on the landscape. Heavy trampling in wet interbeds of sand and mud homogenizes the previously distinct layers into a thicker, more massive unit, typically without any obvious tracks preserved. Although we have identified individual tracks of hippo, antelope, and bird (and a seven print trackway of an early hominid), exact taxonomic assignments are not easily made.
Albedo over the boreal forest

Using the Boreal Ecosystem-Atmosphere Study mesonet data, we show the annual cycle of albedo for 1994 and 1995 at 10 sites; two over grass, one over an aspen forest, and an average of seven over coniferous forests. Representative daily average albedo values in summer are 0.2 over grass, 0.15 for aspen, and 0.083 for the conifer sites. In winter the corresponding mean albedo for snow-covered grass, aspen, and conifer sites with snow under the canopy are 0.75, 0.21, and 0.13. The jack pine sites have a higher mean winter albedo of 0.15 than the predominantly spruce sites for which mean albedo is only 0.11. Forest albedo increases at all sites in winter (with snow on the ground under the canopy) as the ratio of diffuse to total solar flux increases. The albedo of the conifer sites in winter rarely reaches 0.3.
Full-field ultrasonic measurement (ultrasonic tomography) in experimental geomechanics

Whilst ultrasonic wave measurements have been used for a relatively long time as a non-destructive method in laboratory soil and rock mechanics. However, such measurements can have significant limitations in the presence of heterogeneities, either pre-exisiting or evolving in the form of deformation structures, which are common in geomaterials. With heterogeneity, measurement of wave propagation along just a few directions in a sample can not provide a good characterisation of a material’s elastic properties nor of the changes in them associated with deformation; only averages along the (limited number of) propagation paths can be described. Ultrasonic tomography provides the possibility to assess the spatial, and eventually temporal, variations in ultrasonic velocity (and attenuation) within geomechanics test specimens and thus overcome the spatial sampling limitations of standard approaches. This paper provides an overview of ultrasonic tomography and its application as a full-field measurement tool in experimental geomechanics plus provides demonstration of the power of the method with two examples.
Effects of lake acidification on rates of organic matter decomposition in sediments

Summer hypolimnetic and whole-lake under-ice measurements in an experimentally acidified lake suggested that rates of in situ decomposition in sediments (measured as methane and inorganic carbon release) were unaffected over an epilimnetic pH range of 6.7-5.1. This was apparently because microbial processes kept the pH at 6.0 or above just a few millimeters below the sediment surface even after lake water had been acidified for 8 years. In laboratory studies where the pH of mixed, fresh lake sediment was controlled at reduced levels, decomposition rates of carbon that had been in the sediments for several months were unaffected at pH values as low as 4.0. However, decomposition rates of newly sedimented material began to decrease at pH 5.25-5.0. Decomposition processes were less affected during the acidification of Lake 223 than were higher life forms.