Miracle-dz/UniFAR-FTUs huggingface dataset:
Spherical and columnar, septarian, 18O‐depleted, calcite concretions from Middle–Upper Permian lacustrine siltstones in northern Mozambique: evidence for very early diagenesis and multiple fluids

Calcite septarian concretions from the Permian Beaufort Group in the Maniamba Graben (NW Mozambique) allow controls on the composition and nature of diagenetic fluids to be investigated. The concretions formed in lacustrine siltstones, where they occur in spherical (1 to 70 cm in diameter) and columnar (up to 50 cm long) forms within three closely spaced, discrete beds totalling 2·5 m in thickness. Cementation began at an early stage of diagenesis and entrapped non‐compacted burrows and calcified plant roots. The cylindrical concretions overgrew calcified vertical plant roots, which experienced shrinkage cracking after entrapment. Two generations of concretionary body cement and two generations of septarian crack infill are distinguished. The early generation in both cases is a low‐Mn, Mg‐rich calcite, whereas the later generation is a low‐Mg, Mn‐rich calcite. The change in chemistry is broadly consistent with a time (burial)‐related transition from oxic to sub‐oxic/anoxic conditions close to the sediment–water interface. Geochemical features of all types of cement were controlled by the sulphate‐poor environment and by the absence of bacterial sulphate reduction. All types of cement present have δ13C ranging between 0‰ and −15‰(Vienna Peedee Belemnite, V‐PDB), and highly variable and highly depleted δ18O (down to 14‰ Vienna Standard Mean Ocean Water, V‐SMOW). The late generation of cement is most depleted in both 13C and 18O. The geochemical and isotopic patterns are best explained by interaction between surface oxic waters, pore waters and underground, 18O‐depleted, reducing, ice‐meltwaters accumulated in the underlying coal‐bearing sediments during the Permian deglaciation. The invariant δ13C distribution across core‐to‐rim transects for each individual concretion is consistent with rapid lithification and involvement of a limited range of carbon sources derived via oxidation of buried plant material and from dissolved clastic carbonates. Syneresis of the cement during an advanced stage of lithification at early diagenesis is considered to be the cause of development of the septarian cracks. After cracking, the concretions retained a small volume of porosity, allowing infiltration of anoxic, Ba‐bearing fluids, resulting in the formation of barite. The results obtained contribute to a better understanding of diagenetic processes at the shallow burial depths occurring in rift‐bound, lacustrine depositional systems.
BORON SORPTION ON CALCAREOUS SOILS AND REFERENCE CALCITES

Boron sorption on two calcareous soils, one noncalcareous soil, and two reference calcites was investigated in batch systems both as a function of solution pH (5.5–12) and as a function of initial B concentration (1–250 g B m−3). Boron sorption was investigated on untreated soil samples, and soil samples treated with dilute acid to remove soil calcite. Boron sorption on the soil samples increased from pH 5.5 to 9, exhibited a peak near pH 9.5, and decreased from pH 10 to 11.5. Boron sorption on the two reference calcites exhibited an adsorption envelope with maximum sorption occurring near pH 9.5. The magnitude of the B adsorption maximum was significantly lower for the soil samples treated for calcite removal than for the untreated soil samples. This result indicates that calcite plays an important role in B sorption by calcareous soils. Boron sorption as a function of equilibrium B concentration could be described by both the Freundlich and Langmuir adsorption isotherms over the entire concentration range studied on all materials. Goodness of fit of the Langmuir adsorption isotherm equation was much improved over linear transformations by using the program ISOTHERM with its nonlinear least squares optimization routine.
Discovery of Bacteroides uniformis F18-22 as a Safe and Novel Probiotic Bacterium for the Treatment of Ulcerative Colitis from the Healthy Human Colon

Previous studies have demonstrated that the intestinal abundance of Bacteroides uniformis is significantly higher in healthy controls than that in patients with ulcerative colitis (UC). However, what effect B. uniformis has on the development of UC has not been characterized. Here, we show for the first time that B. uniformis F18-22, an alginate-fermenting bacterium isolated from the healthy human colon, protects against dextran-sulfate-sodium (DSS)-induced UC in mice. Specifically, oral intake of B. uniformis F18-22 alleviated colon contraction, improved intestinal bleeding and attenuated mucosal damage in diseased mice. Additionally, B. uniformis F18-22 improved gut dysbiosis in UC mice by increasing the abundance of anti-inflammatory acetate-producing bacterium Eubacterium siraeum and decreasing the amount of pro-inflammatory pathogenetic bacteria Escherichia-Shigella spp. Moreover, B. uniformis F18-22 was well-tolerated in mice and showed no oral toxicity after repeated daily administration for 28 consecutive days. Taken together, our study illustrates that B. uniformis F18-22 is a safe and novel probiotic bacterium for the treatment of UC from the healthy human colon.
In-flight monitoring and calibration of the x-ray polarimeters on board IXPE: year two

The Imaging X-ray Polarimetry Explorer (IXPE) mission, done in collaboration between NASA and the Italian Space Agency (ASI), has been successfully detecting x-ray polarization from celestial sources for more than one year. This mission comprises three x-ray optics and three x-ray polarization sensitive detectors. Four calibration sources based on 55Fe nuclides, one producing polarized radiation (at two energies) and three producing unpolarized radiation, are present on board with each detector. In this contribution we present the in-flight monitoring and calibration of IXPE using these sources, with particular regard to the calibrations of the spectral and polarization response. We also show the monitoring of the optics half-power diameter.
Three-dimensional ground movements in the vicinity of a mining activated geological fault

Abstract This paper investigates the circumstances and conditions that lead to the activation of a particular geological fault when longwall panel extraction occurs in the vicinity. Three-dimensional ground movements were observed at survey stations located across a fault as these were being influenced by active mining. The development of ground movements is defined be recording the subsidence, strain and horizontal displacements of the survey stations. The measured ground movements are compared to the predicted Subsidence Engineer's Handbook and in-house Subsidence Prediction Program subsidence and strain profiles, and the visual damage evident along the testline. Conclusions are drawn which suggest that surface geology heavily influences the location and magnitude of sustained surface damage.
Capital Structure and Earnings Management Practices: Empirical Analysis in Sub-Sahara Africa

: This study assesses the impact of capital structure (CS) on Earnings Management Practices (EMP) in selected firms in sub-Sahara Africa. EMP was proxied by real EMP using Rowchodhury's (2006) model and accrual EMP measured by Khothari et al . (2005) model. The study applied the Generalized Method of Moments (GMM) estimator to data collected from the financial statements of two hundred and seventy-six (276) firms purposively selected from Nigeria, Ghana, Kenya, Tanzania, South Africa, and Zimbabwe from 2010 to 2020, given 3,069 observations firm-years. The results show that firms in Kenya, Nigeria, and Tanzania partake in real EMP through the structure of their capital. However, firms in Ghana, South Africa
Exploring Students’ Academic Emotions Through a Conservation Education Program

Research and practice in educational settings should consider exploring the rich diversity of emotions experienced by students outside classroom settings, including nature clubs, as a conservation education program. This study aimed to conduct an exploratory case study to explore students' academic emotions during conservation education programs. The case study was carried out for four weeks to determine what can be learned from a single case about the students’ emotional aspects of the conservation education program in the Nature Club. Data collection is conducted through observation, interview, and collection of documents at the end of every activity. The data consisted of field notes and videotapes from observation, interview transcripts, and student emotions diary (SED). The research participant was 21 elementary students aged 9 to 11 who joined the Nature Club conducted by the Little Fire Pace (LFP) Community as one of their conservation education programs. The result shows that conservation content which is also part of science, can be learned and stimulate the emergence of students' academic emotions, both positive and negative. The dominant emotion in nature club activities is the happy emotion, and the slightest emotion arising from this activity is disgust. Then the results of student interest in all activities were more remarkable than boredom. Finally, suggestions are made on implications for teacher or pre-service teacher education for conservation or science education.
Southern Argentina Agile Meteor Radar: Initial assessment of gravity wave momentum fluxes

[1] The Southern Argentina Agile Meteor Radar (SAAMER) was installed on Tierra del Fuego (53.8°S) in May 2008 and has been operational since that time. This paper describes tests of the SAAMER ability to measure gravity wave momentum fluxes and applications of this capability during different seasons. Test results for specified mean, tidal, and gravity wavefields, including tidal amplitudes and gravity wave momentum fluxes varying strongly with altitude and/or time, suggest that the distribution of meteors throughout the diurnal cycle and averaged over a month allows characterization of both monthly mean profiles and diurnal variations of the gravity wave momentum fluxes. Applications of the same methods for real data suggest confidence in the monthly mean profiles and the composite day diurnal variations of gravity wave momentum fluxes at altitudes where meteor counts are sufficient to yield good statistical fits to the data. Monthly mean zonal winds and gravity wave momentum fluxes exhibit anticorrelations consistent with those seen at other midlatitude and high-latitude radars during austral spring and summer, when no strong local gravity wave sources are apparent. When stratospheric variances are significantly enhanced over the Drake Passage “hot spot” during austral winter, however, MLT winds and momentum fluxes over SAAMER exhibit very different correlations that suggest that MLT dynamics are strongly influenced by strong local gravity wave sources within this “hot spot. ” SAAMER measurements of mean zonal and meridional winds at these times and their differences from measurements at a conjugate site provide further support for the unusual momentum flux measurements.
Origin of the Ninety East Ridge from studies near the equator

A part of the Ninety East ridge near the equator was examined in 1971 by seismic profiling and gravity and magnetic observations. In the area examined, the topography of the ridge consists of blocklike or en echelon mountainous masses. A fracture zone trending north-south parallel to the overall trend was found along the eastern margin of the ridge topography. This fracture zone probably marks the principal boundary between the central Indian Ocean plate and the Wharton basin plate. The free air gravity anomalies associated with the Ninety East ridge are small, and thus the mass of the ridge must in some way be compensated at depth. The Ninety East ridge may have originated as a result of emplacement of gabbro and serpentinized peridotite beneath normal oceanic crustal layers. The lower density of the gabbro and serpentinized peridotite with respect to normal mantle at equivalent depths provides for both the uplift of the ridge and its compensation at depth.
Lagrangian eddy statistics from surface drifters in the eastern North Atlantic

En 1976-1977, 16 flotteurs derivant en surface avaient ete disperses sur une aire de 100 km de diametre, pour etudier la diffusion induite par des courants basse frequence associes aux tourbillons de mesoechelle presents dans la region est de l'ocean Atlantique nord. Il a ete trouve que la formule de Taylor reliant la diffusivite (taux de dispersion) des parcelles marquees de fluide, a l'integrale de la fonction de correlation de Lagrange, est precise jusqu'a 30 jours. La diffusivite, initiallement nulle, atteint un plateau apres 10 jours. Les diffusivites associees a l'echelle de temps des tourbillons energetiques (30 jours) sont egales a 2,3×10 7 cm 2 /1 et a 1,7×10 7 cm 2 /s, respectivement dans les directions zonale et meridienne. Apres 30 jours, la diffusivite decroit et la dispersion se sature. Le contenu en energie turbulente lagrangienne est alors faible aux basses frequences, par opposition au contenu en energie eulerienne en subsurface, dans la meme aire. Le centre de gravite du spectre d'energie lagrangienne et eulerienne fournit les echelles respectives; 12 et 26 jours. Aux frequences superieures a 0,1 cycle/jour, le spectre de vitesse lagrangienne se termine par une pente en −2
Joint estimation of afterslip rate and postseismic relaxation following the 1989 Loma Prieta earthquake

Global Positioning System (GPS) data from campaigns carried out over the 5 years following the 1989 Loma Prieta earthquake and leveling data measured in 1990 and 1992 define the postseismic velocity field around the Loma Prieta rupture zone. Subtraction of a background velocity field yields a residual velocity pattern which we interpret as the product of two physical processes: (1) slow afterslip along distinct planes in the upper cru, st and (2) viscoelastic relaxation of the lower crust and upper mantle. Biirgmann et al. (1997) previously derived an afterslip model involving uniform afterslip on two optimally determined planes, in- cluding oblique reverse slip on the coseismic rupture and reverse slip on a shallow thrust fault to the northeast of the San Andreas fault. We further consider models of distributed slip on these two fault planes plus a viscoelastic relaxation pattern which depends on a suitable cose- ismic rupture model and crust and mantle viscosities. Several fault models from the literature were considered for the 1989 coseismic rupture, with nearly identical impact on the results. Simultaneous maximum likelihood inversion of the GPS and leveling data for afterslip distri- bution and viscosity yields the following results: (1) A good fit to the data is obtained by smooth afterslip distributions without any viscoelastic relaxation being required. (2) Tangible broad-scale viscoelastic relaxation of the lower crust and upper mantle are present in this data set at 97% confidence, and a lower crustal viscosity of- 1029 Pa s is obtained; however, the viscosity of both the lower crust and upper mantle are poorly constrained. (3) For a given misfit, 20% less integrated afterslip and smoother afterslip distributions result when viscoelas- tic relaxation is included. (4) Maximum slip rates on the slip-distributed models are 3-5 crn/yr, the dominant patches estimated on the two planes fill in the entire depth range 4-13 km without significant overlap, and deeper afterslip is not required. The afterslip distribution on the coseismic rupture plane is strongly dominated by reverse slip immediately southeast of the main center of coseismic reverse slip.
Frequency of Mine Dust Episodes and the Influence of Meteorological Parameters on the Witwatersrand Area, South Africa

Aeolian dispersal of dust from gold mine tailing storage facilities impacts negatively on amenities, human health, and the environment of the Witwatersrand region, South Africa. The present study adopted a multivariate analytical method to quantify the effect of specific meteorological parameters on dust fall emissions, monitored at 22 sites in the central Witwatersrand area. Using meteorological and dust fall data from 2001 to 2010, the relationships between weather and dust fallout deposition rates were explored across the sites at different seasons. Dust deposition rate varied among seasons, with spring months showing the highest levels and frequency. Atmospheric humidity had negative correlations () with dust fall while wind speed showed positive correlations () at the selected sites (). Sites with low influence of relative humidity had higher impact on wind speed. Mean relative humidity below 50% and mean wind speed above 4 m/s were predicted as critical levels for dust episodes incidence at sites that recorded “heavy” and “very heavy” dust fall. For environmental planning purposes, current mitigation measures should be manipulated in relation to levels of air humidity and wind speed for dust emission reduction, especially during spring.
Evaluation of Methods for Estimating Net Nitrogen Mineralization in a Semiarid Grassland

Methods for estimating net N mineralization in semiarid grasslands are not well tested. We compared three in situ incubation methods to evaluate (i) effects of root density and length of incubations on methodological artifacts involving N immobilization, (ii) effects of sieving on estimates of net N mineralization, and (iii) effects of containment on soil water dynamics. We incubated intact soils and sieved soils with or without roots for 15 to 90 d in uncovered tubes and determined changes in NO₃ and NH₄. Net N mineralization was transient and usually declined after 15 to 30 d. Nitrogen immobilization may have contributed to decreases in extractable N, but root abundance was not a dominant control of net N mineralization. Greater root mass under blue grama grass [Bouteloua gracilis (Willd. ex Kunth) Lagasca ex Griffiths] plants was expected to promote immobilization, but net N mineralization was higher under plants than in bare areas. Removing roots from sieved soil enhanced net mineralization, but not consistently. Sieving soil caused problematic changes in N dynamics. Under plants, for example, N concentrations were higher in sieved than intact soil after 15 d, but lower after 60 d. Effects of sieving may reflect accelerated depletion of a small, biologically active organic matter pool during prolonged incubations. Soil in tubes was slightly wetter than bulk soil during moist periods, but water content in tubes tracked ambient conditions well. We recommend 15- to 30-d incubations of intact cores to avoid artificially high rates of net mineralization caused by soil disturbance and to capture effects of environmental variation. Research was performed at Colorado State Univ., Fort Collins, CO 80523.
Spatial Variation of Intertidal Macrofauna on a Sandy Ocean Beach in Australia

Abstract Spatial variation of macrofauna on a sandy beach was examined simultaneously over two scales across-shore (among and within zones) and three nested scales along-shore over the entire length of the beach. Prior to the main study, pilot studies were performed to determine: (1) the relative efficiency, accuracy and precision of combinations of core size, depth of sampling, and sieve mesh size; and (2) the likely distribution of macrofauna across-shore so that stratification of sampling in the main study would be meaningful. From this, three zones were defined across-shore, namely: (1) the high-shore zone which extended 10 m downshore of the drift line and was dominated by two species of isopod; (2) the mid-shore zone which extended across the beach from the bottom of the high-shore zone to the top of the swash zone and was dominated by the glycerid polychaete Hemipodus sp. ; and (3) the swash zone which contained more species than the other two zones and was dominated by amphipods, Hemipodus sp. , the bivalve Donax deltoides and a species of cumacean. In the main study, multivariate analyses confirmed that assemblages of macrofauna varied significantly among zones despite smaller scale variation within zones and along-shore variation. Significant along-shore variation was detected in assemblages of macrofauna from each zone and occurred at different scales for different zones. Only assemblages in the swash zone showed a pattern of along-shore variation that was consistent with a gradient in wave exposure along the beach. Univariate analyses showed that significant variation in populations of individual taxa occurred at both large and small scales. Significant variation was detected across-shore within zones for nearly all variates and this demonstrated the importance of formally assessing variation within zones when making comparisons among zones. Significant variation was also detected along-shore in analyses of particular taxa, and interactions of across- and along-shore variation also occurred. These results illustrate the necessity of considering both across- and along-shore variation for describing spatial patterns in assemblages or individual species of macrofauna. Unfortunately, sampling a single transect across a beach, which is common in many published descriptions of spatial patterns, will not provide an adequate nor representative description of the macrofauna of that beach because this approach fails to consider all important sources of variation and confounds large- and small-scale variation. The authors conclude that a better understanding of small-scale variation, both along- and across-shore within beaches, is required in order to provide better descriptions of patterns, provide a basis for larger scale studies, allow unconfounded comparisons among beaches and, ultimately, to improve our understanding of the ecology of sandy beaches.
An experimental test of whether bar instability contributes to the formation, periodicity and maintenance of pool–riffle sequences

Pool–riffle sequences (PRSs) are periodic river‐bed morphologies with wavelengths several times the channel width. Causes of PRS formation and maintenance are not clearly understood, which may limit the effectiveness of protection and rehabilitation measures. Some confusion has existed about whether the PRS morphology is the same as or distinct from alternate bars. In this paper we investigate whether the bar instability forming alternate bars also contributes to PRS formation, periodicity and maintenance. This was unclear because bar instability occurs only when the ratio of channel width/depth exceeds a critical value, generally understood to be approximately 10, which is larger than the width‐to‐depth ratio of many PRSs. A mobile‐bed physical model is used to test whether bar instability occurs in channels characteristic of PRS morphology, with low width‐to‐depth ratio, and high relative roughness. The physical model was scaled from a prototype PRS in a gravel and cobble bed river. Alternate bars formed in the model at channel width‐to‐depth ratios as low as 3·8. The wavelength of the alternate bars formed was generally 2·2–5 times channel width, which was similar to the prototype PRS. Therefore, bar instability can occur in virtually all PRSs, and it contributes to the widespread formation of periodic PRS morphology. The model showed that maintenance of the bar height in the prototype PRS also depends on variations in channel width. It is concluded that periodic PRSs are formed and maintained by the interaction between bar instability, and flow deflections associated with variations in channel geometry such as width variation. Resonance between bar instability and three‐dimensional bed forms such as alternate bars and variations in channel geometry. Variations in channel geometry are also important in determining the location and dimensions of individual pools and bars. Copyright © 2008 John Wiley & Sons, Ltd.