Miracle-dz/UniFAR-FTUs huggingface dataset:
Mechanisms Controlling the Distribution and Transport of 14C in a Clay‐Rich Till Aquitard

The distribution and transport of radiocarbon in dissolved inorganic carbon (DIC) in a thick clay‐rich till aquitard was investigated. Radiocarbon activities decreased with depth from 109 percent modern carbon (pmC) in the surficial oxidized and fractured zone (at 1.5 m BG) through the thick underlying unoxidized and nonfractured aquitard, reaching minimum values of between 3 and 5 pmC at between 29 and 37 m depth. Numerical simulations of diffusive transport of radiocarbon from the oxidized zone into the unoxidized zone during the Holocene closely approximated the measured values and showed that diffusive transport and radioactive decay fully described the transport of radiocarbon in the aquitard. The lack of geochemical reactions involving DIC permitted the age of DIC in the pore water deposited with the till (between 29 and 37 m BG) to be estimated at 25 to 31 ka BP. Results of this study showed that the use of radiocarbon in the study of solute transport in aquitards provides age information that cannot be obtained from natural conservative tracers such δ2H and δ18. Our results also showed that the application of conventional radiocarbon age‐dating models based on piston‐flow transport assumptions, is inappropriate in diffusion‐dominated environments and considerably overestimates the age of the ground water.
Exploring a Possible Link Between ADHD and Inattentional Blindness

Attention Deficit Hyperactivity Disorder (ADHD) is characterized by impulsivity, hyperactivity, and inattention. These symptoms of inattention led us to wonder about a connection between ADHD and the phenomenon of inattentional blindness. We attempted to replicate a previous study done on this subject, and based on the results of that study, we hypothesized that people with ADHD would display more inattentional blindness in perceptually simple tasks and less inattentional blindness in perceptually complex tasks. Our results indicate that there is no significant correlation between ADHD and inattentional blindness in either type of task. This finding goes against our initial hypothesis and the conclusions from the only prior study on this topic. People with ADHD may not have the advantage of reduced inattentional blindness.
Geomagnetic episodes of the last 1.2 Myr recorded in Chinese loess

The Matuyama‐Brunhes (M/B) boundary, termination of Jaramillo normal subchron (J/M) as well as three young geomagnetic excursions has been revealed in the Weinan loess section [ Zhu et al., 1994 , 1998 , 1999 ]. Recently, we carried out further paleomagnetic directional studies on the same section and recovered the onset of the Jaramillo normal subchron (M/J) and four geomagnetic excursions, two in the Brunhes and two in the late Matuyama. The fact that all seven excursions found in this section are in loess units and expected excursions in paleosols are not found suggests that short‐lived geomagnetic signals could be only recorded in loess units, and may have been fully smoothed or wiped out in paleosol units by strong pedogenesis. Constrained by a new astronomical timescale (HLD00), ages of the geomagnetic excursions and reversal boundaries have been estimated. We tentatively correlated these excursions with previous results, indicating that a large lock‐in model may not be correct for the whole loess profile, although some apparently big positive age discrepancies were observed for the main boundaries.
A clockwise rotation of southern Apulia

New paleomagnetic results from 13 sites sampled in Eo-Oligocene autochthonous formations in the extreme South of the Apulian platform in southeastern Italy are presented. They suggest that this region has undergone a clockwise rotation of about 25° since the Eo-Oligocene. This rotation is opposite in sense to that obtained from the Cretaceous formations in the Gargano, which has generally been assumed to affect the entire foreland. These new data suggest that the Tertiary structural evolution of this region may be distinct from that of central peninsular Italy and related to that of northwestern Greece on the other side of the Southern Adriatic Sea.
A current velocity index of ocean variability

We use daily time series of the longshore component of residual (detided) current velocity υ(z, t) measured at several depths at a single location on the continental slope to construct a current velocity index, Iυ ≡ α|υ′s∂υ/∂z|∂υ/∂z, of coastal ocean variability. Here z is depth, t is time, and α = −sgn(f)[(f2 + δ2)συ]−1 is a normalization factor constructed from the local Coriolis parameter f, a friction parameter δ, and the standard deviation συ of the near-surface current velocity, , where υ′s is the fluctuation about the time series mean ; sgn(f) = +1 for the northern hemisphere and −1 for the southern hemisphere. The time series of vertical shear, ∂υ/∂z ≈ Δυ/Δz, is derived from the velocity difference Δυ between simultaneous current meter records separated by a vertical distance Δz within the upper half of the water column. The index characterizes low-frequency baroclinic variability over the continental margin and is linked, through use of the thermal wind relation, to instability processes that effect the transfer of potential energy stored in the mean cross-slope density field to the kinetic energy of mesoscale meanders and eddies. For eastern boundary regions the index ranges from large positive values during summer upwelling conditions to large negative values during winter downwelling conditions. The “transition” seasons, spring and fall, are characterized by Iυ ≈ 0. We demonstrate use of the index by applying it to the continental margin of southwest Vancouver Island using current velocity data collected from October 1989 to March 1995 at depths of 35, 100, 175, and 400 m at a long-term mooring site. Results enable us to specify the start and end times of the oceanic seasons and to quantify the summer upwelling and winter downwelling intensities for the region. Gaps in the current meter time series prompted us to examine records of coastal sea level, sea surface temperature, sea surface salinity, and “Bakun” upwelling index (the wind-driven cross-shore component of surface Ekman transport) as possible surrogates for the velocity index. None of these time series were acceptable. Although the Bakun index is a logical substitute for the velocity index, differences between the two indices are significant and suggest that current velocity data are needed for accurate delineation of seasonal oceanic variability along continental margins.
Combining satellite data and biogeochemical models to estimate global effects of human‐induced land cover change on carbon emissions and primary productivity

This study uses a global terrestrial carbon cycle model (the Carnegie‐Ames‐Stanford Approach (CASA) model), a satellite‐derived map of existing vegetation, and global maps of natural vegetation to estimate the effects of human‐induced land cover change on carbon emissions to the atmosphere and net primary production. We derived two maps approximating global land cover that would exist for current climate in the absence of human disturbance of the landscape, using a procedure that minimizes disagreements between maps of existing and natural vegetation that represent artifacts in the data. Similarly, we simulated monthly fields of the Normalized Difference Vegetation Index, required as input to CASA, for the undisturbed land cover case. Model results estimate total carbon losses from human‐induced land cover changes of 182 and 199 Pg for the two simulations, compared with an estimate of 124 Pg for total flux between 1850 and 1990 [Houghton, 1999], suggesting that land cover change prior to 1850 accounted for approximately one‐third of total carbon emissions from land use change. Estimates of global carbon loss from the two independent methods, the modeling approach used in this paper and the accounting approach of Houghton [1999], are comparable taking into account carbon losses from agricultural expansion prior to 1850 estimated at 48–57 Pg. However, estimates of regional carbon losses vary considerably, notably in temperate midlatitudes where our estimates indicate higher cumulative carbon loss. Overall, land cover changes reduced global annual net primary productivity (NPP) by approximately 5%, with large regional variations. High‐input agriculture in North America and Europe display higher annual NPP than the natural vegetation that would exist in the absence of cropland. However, NPP has been depleted in localized areas in South Asia and Africa by up to 90%. These results provide initial crude estimates, limited by the spatial resolution of the data sets used as input to the model and by the lack of information about transient changes in land cover. The results suggest that a modeling approach can be used to estimate spatially‐explicit effects of land cover change on biosphere‐atmosphere interactions.
Evaluation of persistent hydrophobic organic compounds in the Columbia River Basin using semipermeable‐membrane devices

Persistent hydrophobic organic compounds are of concern in the Columbia River because they have been correlated with adverse effects on wildlife. We analysed samples from nine main‐stem and six tributary sites throughout the Columbia River Basin (Washington and Oregon) for polychlorinated dibenzo‐p‐dioxins, dibenzofurans, polychlorinated biphenyls, organochlorine pesticides, and priority‐pollutant polycyclic aromatic hydrocarbons. Because these compounds may have important biological consequences at aqueous concentrations well below the detection limits associated with conventional sampling methods, we used semipermeable‐membrane devices to sample water and achieved parts‐per‐quintillion detection limits. All of these compound classes were prevalent within the basin, but concentrations of many analytes were highest in the vicinity of Portland–Vancouver, indicating that the Willamette subbasin—and perhaps the urban area in particular—is an important source of these compounds. Data collected during basin low‐flow conditions in 1997 and again during basin high‐flow conditions in 1998 indicate that in‐stream processes such as dilution by relatively clean inflows, and flow through island hyporheic zones may be important mechanisms for attenuating dissolved concentrations of hydrophobic compounds. Published in 2001 by John Wiley & Sons, Ltd.
Evolution of the late Cenozoic Chaco foreland basin, Southern Bolivia

Eastward Andean orogenic growth since the late Oligocene led to variable crustal loading, flexural subsidence and foreland basin sedimentation in the Chaco basin. To understand the interaction between Andean tectonics and contemporaneous foreland development, we analyse stratigraphic, sedimentologic and seismic data from the Subandean Belt and the Chaco Basin. The structural features provide a mechanism for transferring zones of deposition, subsidence and uplift. These can be reconstructed based on regional distribution of clastic sequences. Isopach maps, combined with sedimentary architecture analysis, establish systematic thickness variations, facies changes and depositional styles. The foreland basin consists of five stratigraphic successions controlled by Andean orogenic episodes and climate: (1) the foreland basin sequence commences between ∼27 and 14 Ma with the regionally unconformable, thin, easterly sourced fluvial Petaca strata. It represents a significant time interval of low sediment accumulation in a forebulge‐backbulge depocentre. (2) The overlying ∼14–7 Ma‐old Yecua Formation, deposited in marine, fluvial and lacustrine settings, represents increased subsidence rates from thrust‐belt loading outpacing sedimentation rates. It marks the onset of active deformation and the underfilled stage of the foreland basin in a distal foredeep. (3) The overlying ∼7–6 Ma‐old, westerly sourced Tariquia Formation indicates a relatively high accommodation and sediment supply concomitant with the onset of deposition of Andean‐derived sediment in the medial‐foredeep depocentre on a distal fluvial megafan. Progradation of syntectonic, wedge‐shaped, westerly sourced, thickening‐ and coarsening‐upward clastics of the (4) ∼6–2.1 Ma‐old Guandacay and (5) ∼2.1 Ma‐to‐Recent Emborozú Formations represent the propagation of the deformation front in the present Subandean Zone, thereby indicating selective trapping of coarse sediments in the proximal foredeep and wedge‐top depocentres, respectively.
Geospatially based distributed rainfall‐runoff modelling for simulation of internal and outlet responses in a semi‐forested lower Himalayan watershed

This study presents a Geographic Information System (GIS)‐based distributed rainfall‐runoff model for simulating surface flows in small to large watersheds during isolated storm events. The model takes into account the amount of interception storage to be filled using a modified Merriam ( 1960 ) approach before estimating infiltration by the Smith and Parlange ( 1978 ) method. The mechanics of overland and channel flow are modelled by the kinematic wave approximation of the Saint Venant equations which are then numerically solved by the weighted four‐point implicit finite difference method. In this modelling the watershed was discretized into overland planes and channels using the algorithms proposed by Garbrecht and Martz ( 1999 ). The model code was first validated by comparing the model output with an analytical solution for a hypothetical plane. Then the model was tested in a medium‐sized semi‐forested watershed of Pathri Rao located in the Shivalik ranges of the Garhwal Himalayas, India. Initially, a local sensitivity analysis was performed to identify the parameters to which the model outputs like runoff volume, peak flow and time to peak flow are sensitive. Before going for model validation, calibration was performed using the Ordered‐Physics‐based Parameter Adjustment (OPPA) method. The proposed Physically Based Distributed (PBD) model was then evaluated both at the watershed outlet as well as at the internal gauging station, making this study a first of its kind in Indian watersheds. The results of performance evaluation indicate that the model has simulated the runoff hydrographs reasonably well within the watershed as well as at the watershed outlet with the same set of calibrated parameters. The model also simulates, realistically, the temporal variation of the spatial distribution of runoff over the watershed and the same has been illustrated graphically. Copyright © 2011 John Wiley & Sons, Ltd.
Hydrocarbon Habitat in Main Producing Areas, Saudi Arabia: DISCUSSION

Current hydrocarbon production in Saudi Arabia is from reservoirs of Cretaceous and Jurassic age. Geochemical studies of the sediments and oils suggest that the hydrocarbons were derived from two separate source-rock provinces. Oil production from the large fields in the southern part of the area is from Jurassic carbonate reservoirs. Most of these oils were derived from thermally mature, thinly laminated, organic-rich carbonate rocks of Jurassic age (Callovian-Oxfordian). These source rocks were deposited in an intrashelf basin which is limited to the southern part of the main producing areas. Extensive vertical migration of oils originating in these sediments is prevented by superjacent evaporite seals deposited during the Late Jurassic. Fields in the northern producing areas appear to have derived their hydrocarbons from a source-rock province on the north. Production from Cretaceous clastic and carbonate reservoirs is limited to the northeastern part of the producing areas. This distribution may be explained by limitation of thermally mature Cretaceous source rocks to the northeastern areas or by the local lack of subjacent evaporite seals to separate these reservoirs from Jurassic source rocks. Thermal maturation studies indicate that the hydrocarbons in Mesozoic reservoirs migrated into the present traps during the early Tertiary.
The Effect of Clay Content on Liquid Limit from a Fall Cone and the British Cup Device

The many shortcomings of the Casagrande cup device, used almost univerally to determine the liquid limit of soils, led to the investigation of fall cones as alternatives. In two of the four types of fall cones in use, investigators have shown that the differences between fall cone liquid limit values and cup liquid limit values were not large. Evidence is produced to show that the fall cones of the same cone angle would give identical results if the appropriate depth of penetration is specified. Tests conducted using a British/French fall cone and a British cup device reveal that the difference in liquid limit values between these two devices is related to the amount of clay in the soil. A one point fall cone method is shown to be sufficiently accurate to deduce the liquid limit of soils. The fall cone method is a rational alternative to the cup device, and since engineers are interested in strength, the liquid limit could perhaps be defined as the water content at which a soil would have a specific undrained shear strength (say 1kN/m2).
Active tectonics of the Algerian Atlas Mountains‐evidence from aftershocks of the 1980 El Asnam earthquake

Summary The El Asnam (Algeria) earthquake of 1980 October is the largest earthquake to have occurred in North Africa since instrumental records began (Ms = 7.3). It was caused by movement on a segmented reverse fault which is part of the fault zone that separates the Chelif alluvial plains from the coastal range of the Atlas Mountains. The coastal range is the actively deforming plate boundary between Africa and Eurasia. In this paper, the results of an aftershock study carried out using a 28-station portable network in the epicentral area in the 5 weeks after the main shock are presented. A total of 4517 aftershocks have been located, using both P- and S-phases. Of these 4517 events, 1279 pass a set of quality criteria, and are used to discuss the detailed tectonics of the aftershock zone. The southwestern half of the aftershock zone has a relatively restricted band of seismicity running parallel to the main fault. In cross-section, this seismicity is observed to lie almost exclusively in the footwall of the main fault, and indicates both antithetic reverse faulting and extension parallel to the fault zone. The only exception to this pattern occurs at a junction of the main fault segments, where a distinct cluster of events with very variable focal mechanisms is located in the hangingwall. This cluster may be equated with a barrier that impeded the rupture of the main shock. Beyond the southwest end of the main fault, a mixture of strike-slip and reverse faulting occurred, and suggests a mechanism whereby this end of the fault can act as an asperity for earthquake generation. Aftershocks in the northeastern half of the study area indicate movement on a stack of listric reverse faults. The focal mechanisms of these events show that the N-dipping nodal planes (assumed to be the fault planes) flatten with depth. We suggest that the faults sole into a low-angle (20°) decollement at about 8-10 km depth, at the base of the aftershock zone. We argue that the northeastern part of the 1980 aftershock zone is typical of the actively deforming coastal belt of northwest Algeria. Subduction of the western Mediterranean basin beneath the north African margin does not seem to occur. Instead, the margin is absorbing the motion, with old normal faults being reactivated as thrusts.
Appalachia: A Comparison of the Cognitive and Appalachian Regional Commission Regions

A basic analytical tool in geography is the region, and defining appropriate regional boundaries is a useful but often difficult task. In the United States some regions, such as the Midwest, are amorphous and difficult to delimit. Others, such as Appalachia, are quite vivid and have been much studied yet lack definitive boundaries. This paper compares two types of regionalizations as they apply to Appalachia and addresses two questions: 1) how is the Appalachian region delimited by students who attend colleges and universities in or near the region and 2) to what degree do these cognitive regions agree with the region as defined by the Appalachian Regional Commission (ARC)? The ARC regionalization is the most recent and widely known of the various efforts to delimit Appalachia, and a comparison of the cognitive maps of residents from Appalachia and nearby with the ARC region seems appropriate. DEFINING THE APPALACHIAN REGION. The number ofattempts to objectively define the Appalachian region—and each attempt has been based upon somewhat different criteria—has prompted Whisnant to observe that "Appalachian boundaries have been drawn so many times by so many different hands that it is futile to look for a correct definition of the region. " (J ) One of the first to draw a boundary based upon physiography was Nevin Fenneman. (2) This region included the area from northern Alabama to Newfoundland, but geographers have often abbreviated it to include only that portion south of the Hudson and Mohawk valleys in New York. Fenneman's region includes all or parts of the Appalachian Plateaus, the Ridge and Valley, t_he Blue Ridge, and the
Evaluation of the TOPEX/POSEIDON dual-frequency ionosphere correction

The NASA altimeter on board TOPEX/POSEIDON exploits the difference in the delays of the Ku and C band radar pulses to estimate an ionosphere correction to the range measurement. The dependence of the ionosphere correction on ocean and satellite parameters is less than 1 cm. The standard deviation of the 1-s averaged ionosphere correction depends on the height of the ocean waves and ranges from 5 to 14 mm. The accuracy of the ionosphere correction is better than 1 cm at the 1σ confidence level. The ionosphere correction should be averaged over 140 km (20 s) along track in order to minimize its noise without sacrificing its accuracy. Ionosphere models must achieve an independent sample spacing of 900 km or less in order to allow a single-frequency altimeter to have an ionosphere correction comparable in accuracy to that of the NASA dual-frequency altimeter.
Comparing the Dietary Preference of Caenorhabditis elegans for Bacterial Probiotics vs. Escherichia coli.

The use of probiotics is on the rise as more people are learning about their possible health benefits. In this experiment, we used C. elegans as a simple model organism to observe the impact of probiotics on the human digestive system. In this investigation the dietary preference of C. elegans was tested using three different bacterial probiotics (Chobani, siggi's and Stonyfield) and the control nutrient source, E. coli. The results of the experiment showed that the C. elegans were, on average, most present in Chobani cultures. At the end of the observation period, there were, on average, about 1,207 C. elegans present in the E. coli quadrants, and about 1,314 C. elegans present in the Chobani quadrants, as compared to 1,133 C. elegans in the siggi's quadrants and 981 in the Stonyfield quadrants. There were about 8.9% more C. elegans present in the Chobani quadrants than in the E. coli quadrants. Additionally, the Chobani quadrants grew, on average, by 188 C. elegans/day, 9.3% more than the 172 C. elegans/day growth in the E. coli quadrants. While not statistically significant, these results still demonstrated that C. elegans might prefer Chobani cultures over other probiotic yogurts, which may also indicate greater gut benefits from Chobani over the other yogurt brands tested.