Miracle-dz/UniFAR-FTUs huggingface dataset:
Petrology and chemistry of MIL 03346 and its significance in understanding the petrogenesis of nakhlites on Mars

Abstract— Antarctic meteorite Miller Range (MIL) 03346 is a nakhlite composed of 79% clinopyroxene, ˜1% olivine, and 20% vitrophyric intercumulus material. We have performed a petrological and geochemical study of MIL 03346, demonstrating a petrogenetic history similar to previously discovered nakhlites. Quantitative textural study of MIL 03346 indicates long (>1 × 101 yr) residence times for the cumulus augite, whereas the skeletal Fe‐Ti oxide, fayalite, and sulfide in the vitrophyric intercumulus matrix suggest rapid cooling, probably as a lava flow. From the relatively high forsterite contents of olivine (up to Fo43) compared with other nakhlites and compositions of augite cores (Wo38–42En35–40Fs22–28) and their hedenbergite rims, we suggest that MIL 03346 is part of the same or a similar Martian cumulate‐rich lava flow as other nakhlites. However, MIL 03346 has experienced less equilibration and faster cooling than other nakhlites discovered to date. Calculated trace element concentrations based upon modal abundances of MIL 03346 and its constituent minerals are identical to whole rock trace element abundances. Parental melts for augite have REE patterns that are approximately parallel with whole rock and intercumulus melt using experimentally defined partition coefficients. This parallelism reflects closed‐system crystallization for MIL 03346, where the only significant petrogenetic process between formation of augite and eruption and emplacement of the nakhlite flow has been fractional crystallization. A model for the petrogenesis of MIL 03346 and the nakhlites (Nakhla, Governador Valadares, Lafayette, Yamato‐000593, Northwest Africa (NWA) 817, NWA 998) would include: 1) partial melting and ascent of melt generated from a long‐term LREE depleted mantle source, 2) crystallization of cumulus augite (± olivine, ± magnetite) in a shallow‐level Martian magma chamber, 3) eruption of the crystal‐laden nakhlite magma onto the surface of Mars, 4) cooling, crystal settling, overgrowth, and partial equilibration to different extents within the flow, 5) secondary alteration through hydrothermal processes, possibly immediately succeeding or during emplacement of the flow. This model might apply to single—or multiple—flow models for the nakhlites. Ultimately, MIL 03346 and the other nakhlites preserve a record of magmatic processes in volcanic rocks on Mars with analogous petrogenetic histories to pyroxene‐rich terrestrial lava flows and to komatiites.
ON THE STREAM FUNCTION FOR VARIABLE-DENSITY GROUNDWATER FLOW

When the stream function is used to describe variable-density ground water flow, it should be defined in terms of mass flux. The historic use of the stream function describes volume flux and implicitly invokes the Boussinesq assumption. A comparison of the flow equations for mass-based and volume-based stream functions indicates that this assumption can lead to significant errors in the calculated flow field, especially when flow parallels large density gradients.
The effect of long‐term water table manipulations on dissolved organic carbon dynamics in a poor fen peatland

Dissolved organic carbon (DOC) production, consumption, and quality displayed differences after long‐term (~55 years) hydrological alterations in a poor fen peatland in northern Michigan. The construction of an earthen levee resulted in areas of a raised and lowered water table (WT) relative to an unaltered intermediate WT site. The lowered WT site had greater peat aeration and larger seasonal vertical WT fluctuations that likely elevated peat decomposition and subsidence with subsequent increases in bulk density, vertical hydraulic gradient, decreased hydraulic conductivity (Ksat), and a greater pore water residence time relative to the unaltered site. The raised WT site displayed a decreased Ksat combined with seasonal upwelling events that contributed to a longer residence time in comparison to the unaltered site. These differences are potentially contributing to elevated DOC concentrations at the lowered and raised WT site relative to the unaltered site. Additionally, spectrophotometric indices and chemical constituent assays indicated that the lowered site DOC was more aromatic and contained elevated concentrations of phenolics compared to the intermediate site. The raised site DOC was less aromatic, less humified, and also had a greater phenolic content than the intermediate site. Furthermore, an incubation experiment showed that DOC in the raised site contained the greatest labile carbon source. Based on our results, long‐term WT alterations will likely impose significant effects on DOC dynamics in these peatlands; however, WT position alone was not a good predictor of DOC concentrations, though impoundment appears to produce a more labile DOC whereas drainage increases DOC aromaticity.
On the relationship between continuing current and positive leader growth

It has long been speculated that the source of continuing current (CC) for a negative cloud‐to‐ground flash is provided by the growth of its positive leader into negative charge regions. In this study, data from the Langmuir Electric Field Array (LEFA) and Lightning Mapping Array (LMA) are used to investigate these speculations. LEFA and LMA data provide a way to estimate the occurrence and duration of CC and channel growth throughout a flash, respectively. By connecting LMA VHF sources onto contiguous channels, the growth of the positive leader associated with each return stroke is inferred. A linear correlation between positive‐channel growth and CC duration is found, providing evidence that the positive leader grows with a constant velocity, but no obvious correlation of this velocity with CC occurrence is found. Each return stroke is then sorted by its channel growth rate and further identified by its CC type. This analysis also provides no identifiable correlation linking the positive‐channel growth rate to CC occurrence or duration. Finally, the positive‐channel growth rate for the whole flash is calculated in 10 ms windows so that any trends occurring before, during, or after the CC can be observed. This analysis too shows no correlation, which implies that positive‐channel growth is not the primary mechanism that determines CC occurrence and duration.
A tritium budget for the North Atlantic

We develop a new model bomb-3H budget for the North Atlantic between 1950 and 1986. The model, which calculates the atmospheric and continental 3H delivery as well as the advective 3H transports from the South Atlantic and Arctic, agrees within about 10% with the 3H inventories computed from the 1972 GEOSECS and the 1981–1983 Transient Tracers in the Ocean (TTO) observations. The decay-corrected 3H inventory for the North Atlantic increased by about 43% between the GEOSECS and TTO programs (1972 to 1981), and the inflow of high 3H polar water from the Arctic into the North Atlantic is found to be crucial for correctly simulating this increase. Key aspects of the model that differ from previous studies include the treatment of vapor/rain isotopic equilibrium, the continental vapor flux, and the downward flux of water vapor into the ocean. The sensitivity of the atmospheric 3H delivery to model parameters and to seasonal and interannual variability are explored.
A new tool to trace past human presence from lake sediments: the human‐specific molecular marker Bacteroides strain HF 183

This study presents the results of molecular and palynological analyses of 172 lake sediment samples. By employing a protocol for the semi‐nested polymerase chain reaction using primers for the human‐specific Bacteroides strain HF 183, the DNA of this group of bacteria, which are highly specific markers of faecal pollution of human origin, was identified. The DNA of this bacteria group identified in the sediment bears witness to the past presence of human groups near the lake. The results of completed molecular analyses were collated with palynological data, allowing the vegetation transformations to be reconstructed, including transformations occurring under the influence of human activity. The results obtained show that genetic markers of human presence deposited in lake sediments can form a source of valuable information, allowing phases of human presence in the past, and thus the impact of human on plant associations, to be reconstructed in detail. The combination of both palynological and molecular data originating from the same source (lake sediments) allows for comparison of information about anthropogenic changes to the environment at a regional scale (palynological data) with those recorded at the local scale in the immediate vicinity of the studied lake (molecular data).
Evolution of the Precambrian lithosphere: Seismological and geochemical constraints

Several recent models of crustal evolution are based on the belief that the thickness of the continental crust is proportional to its age, with ancient crust being the thickest. A worldwide review of seismic structure contradicts this belief and falsifies these models, at least for the Archean. Proterozoic crust has a thickness of 40–55 km and a substantial high-velocity (>7 km/s) layer at its base, while Archean crust is only 27–40 km thick (except at the site of younger rifts and collisional boundaries) and lacks the basal high-velocity layer. Seismology also provides evidence that the lithosphere is thickest beneath Archean cratons, while diamond ages show that this lithospheric keel must have already existed in the Archean. Geochemical data also indicate significant differences between Archean and Proterozoic lithosphere. Major and trace element studies of sediments show a change in upper crustal composition between the Archean and Proterozoic. Archean rocks are depleted in Si and K and enriched in Na, Ca, and Mg. There is also a marked change in the Eu/Eu* ratio. Mantle xenoliths and continental flood basalts show that the mantle lithosphere beneath Archean crust is ultradepleted in FeO compared to that beneath post-Archean crust. The secular change in the crust-forming process is attributed to a decline in mantle temperature, leading to a change in the composition of the lithospheric mantle. The higher temperature of the Archean mantle led to the eruption of komatiitic lavas, producing a refractory lithospheric mantle which is ultradepleted in FeO and volatiles. The resultant lithospheric keel is intrinsically less dense than the surrounding mantle and thus not susceptible to delamination. It was sufficiently thick and cool for diamonds to form during the Archean. In contrast, Proterozoic crust developed above fertile mantle. The eruption of continental flood basalts and underplating of basaltic sills is attributed to subsequent heating and partial melting of the lithospheric mantle. Consequently, Proterozoic crust is thickened and has a high-velocity basal layer.
Settling of Fine Sediment in a Channel with Emergent Vegetation

The potential for enhanced removal of sediment from flowing water in a channel by means of settling on vegetation was studied theoretically and experimentally. Settling on vegetation was modeled as a distributed sink of sediment with vegetation spread throughout depth and length of the channel. Sediment-capture experiments were performed in a laboratory channel using model vegetation and well-sorted silt. The theory predicts that settling on vegetation has the potential to increase sediment-capture efficiency considerably, and this was demonstrated in the experiments. The enhancement of sediment removal was greater for artificial vines than for inclined strips. For the runs with flow velocities >10 mm/s the sedimentation efficiency was less than predicted. The reduced efficiency could be related to bed destabilization (which was observed in some runs), re-entrainment from the vegetation, or sediment sliding off the vegetation.
Temperature, oxygen, and vegetation controls on decomposition in a James Bay peatland

The biochemical composition of a peat core from James Bay Lowland, Canada, was used to assess the extent of peat decomposition and diagenetic alteration. Our goal was to identify environmental controls on peat decomposition, particularly its sensitivity to naturally occurring changes in temperature, oxygen exposure time, and vegetation. All three varied substantially during the last 7000 years, providing a natural experiment for evaluating their effects on decomposition. The bottom 50 cm of the core formed during the Holocene Climatic Optimum (~7000–4000 years B.P.), when mean annual air temperature was likely 1–2°C warmer than present. A reconstruction of the water table level using testate amoebae indicated oxygen exposure time was highest in the subsequent upper portion of the core between 150 and 225 cm depth (from ~2560 to 4210 years B.P.) and the plant community shifted from mostly Sphagnum to vascular plant dominance. Several independent biochemical indices indicated that decomposition was greatest in this interval. Hydrolysable amino acid yields, hydroxyproline yields, and acid:aldehyde ratios of syringyl lignin phenols were higher, while hydrolysable neutral sugar yields and carbon:nitrogen ratios were lower in this zone of both vascular plant vegetation and elevated oxygen exposure time. Thus, peat formed during the Holocene Climatic Optimum did not appear to be more extensively decomposed than peat formed during subsequent cooler periods. Comparison with a core from the West Siberian Lowland, Russia, indicates that oxygen exposure time and vegetation are both important controls on decomposition, while temperature appears to be of secondary importance. The low apparent sensitivity of decomposition to temperature is consistent with recent observations of a positive correlation between peat accumulation rates and mean annual temperature, suggesting that contemporary warming could enhance peatland carbon sequestration, although this could be offset by an increasing contribution of vascular plants to the vegetation.
Analysis of monthly and seasonal rainfall trends using the Holt's test

Climate change is a global issue that has impact on every living being in the world. One of the most noticeable consequences of these global phenomena is the inevitable water cycle modification, with precipitation being a major component in these processes. Consequently, research into the occurrence and distribution of precipitation has increased over the past few decades. As Malaysia is located in the tropical area where there is no distinct four seasons, analysing rainfall has therefore become one of the common assessment tools for climate change. In this study, rainfall trends of Langat River Basin were examined on a monthly and seasonal basis (monsoon and non‐monsoon) for the period of 1970–2012. Only rainfall time series with duration more than 25 years and missing data less than 10% have been considered for this study. The Holt's test has been employed to model the rainfall trends for the 10 selected time series; while Kendall's Tau test and Spearman's Rho test were used to test, compare and support for the significance of the trends. For monthly rainfall trends analysis, it was found that March, July and November are among the months those have most of the stations with increasing rainfall trends; while May and September are the months with the highest number of stations showing decreasing rainfall trends. Specifically, station 2815001 shows the highest number of months with changing rainfall trends throughout the year; while station 44255 has the least number of months with changing rainfall trends. Based on the seasonal rainfall trend analysis, there are seven stations during the Northeast Monsoon that revealed upward trends and the result is found to be consistent with the monthly rainfall trend analysis.
Transect across the northwestern Grenville orogen, Georgian Bay, Ontario: Polystage convergence and extension in the lower orogenic crust

The Grenville orogenic cycle, between ∼ 1190 and 980 Ma, involved accretion of magmatic arcs and/or continental terranes to the Laurentian craton. A transect across the western Central Gneiss Belt, Georgian Bay, Ontario, which crosses the boundary between parautochthonous and allochthonous units at an inferred orogenic depth of 20–30 km, offers some insights on the thermal and mechanical behavior of the lower crust during the development of the Grenville orogen. Prior to Grenvillian metamorphism, this part of Laurentia consisted largely of Meso‐proterozoic (∼ 1450 Ma) granitoid orthogneisses, granulites, and subordinate mafic and supracrustal rocks. Grenvillian convergence along the transect began with transport of the previously deformed and metamorphosed (∼ 1160 Ma) Parry Sound domain over the craton sometime between 1120 Ma and 1080 Ma. This stage of transport was followed by out‐of‐sequence thrusting and further convergence along successively deeper, foreland‐propagating ductile thrust zones. A major episode of extension at ∼ 1020 Ma resulted in southeast directed transport of allochthonous rocks along the midcrustal Shawanaga shear zone. The final stage of convergence involved deformation and metamorphism in the Grenville Front Tectonic Zone at ∼ 1000–980 Ma. Peak metamorphism along most of the transect at 1065–1045 Ma followed initial transport of allochthonous rocks over the craton by 15–35 m.y. Regional cooling, which postdated peak metamorphism by >70 m.y. , was probably delayed by the combined effects of late‐stage extension and convergence. Transport of allochthons at least 100 km over the craton was accomplished along a weak, migmatitic decollement; further propagation of the orogen into the craton followed partial melting and weakening of parautochthonous rocks below this decollement. Extensional deformation was associated with distributed ductile flow, the formation of regional transverse folds with axes parallel to the stretching direction, and reactivation of the allochthon‐parautochthon thrust boundary as an extensional decollement. The extensional lower crustal flow was likely the primary cause of the subhorizontal attitude of many structures and seismic reflectors in this part of the Central Gneiss Belt.
Experimental Approach to the Hydraulics of Vertical Slot Fishways

The performance of two particular designs of vertical slot fishways for two different slopes was studied in a wide range of discharges. Water depths were measured in almost the whole surface of pools. A linear relation between dimensionless discharge and depth of flow, and the same flow patterns for each design were found. With an acoustic Doppler velocimeter, three-dimensional velocities were measured at several levels in the entire pool to detect the structure of the flow and quantify velocity distribution. Two different regions in flow patterns were found: a direct flow region characterized by maximum velocities; and a recirculation region, defined by low velocities and horizontal eddies. For a given slope, the velocity at any point of the pool (particularly at the slot) may be considered independent of the discharge and constant with the depth. Some suggestions on kinetic turbulent energy are also made.
Ecología y comportamiento de ungulados en simpatria en un ambiente mediterráneo: interacciones entre especies nativas y exóticas de interés cinegético.

La introduccion de ungulados exoticos es una practica comun en ambientes mediterraneos. Sin embargo, sorprende el escaso numero de estudios que abordan la ecologia y el comportamiento de especies nativas y exoticas en condiciones de simpatria. Esta tesis pretende ampliar el conocimiento de las interacciones inter- e intraespecificas en este tipo de comunidades, abordando aspectos relacionados con el uso de habitat a una escala espacial del paisaje, asi como determinados comportamientos implicados en las mismas. El estudio se llevo a cabo en una finca privada de caza situada en la provincia de Ciudad Real, donde una especie nativa (ciervo iberico Cervus elaphus hispanicus) convive con dos exoticas (muflon europeo Ovis orientalis musimon, y arrui Ammotragus lervia) en un ambiente mediterraneo. Se ha estudiado el grado de solapamiento espacio-temporal y de nicho como medida de una potencial competencia interespecifica. En este sentido se espera competencia entre el ciervo y el muflon, explicada por un solapamiento en la seleccion de determinados recursos durante la epoca de escasez del verano, unido a una alta coincidencia espacio-temporal en los habitats preferidos. Por el mismo motivo, tambien se espera competencia entre el arrui y el muflon, aunque la frecuencia de encuentros entre ambas especies es siempre relativamente alta, independientemente del tipo de habitat. Por otra parte, y a un nivel intraespecifico, se han examinado los patrones de segregacion sexual y las estrategias anti-depredatorias en las diferentes especies. De esta forma, la segregacion sexual es mas evidente en el ciervo que en el muflon, lo cual podria relacionarse con el mayor grado de dimorfismo sexual del primero. El habitat explica parcialmente los patrones de segregacion para las dos especies, aunque de forma mas notable en el caso del ciervo. Las estrategias anti-depredatorias presentan variaciones tanto inter- como intraespecificas: en el ciervo se basan en diferencias en los ritmos de actividad segun el tipo de individuo y el estado reproductivo, mientras que en el arrui estas estan mas relacionadas con el tamano de grupo. En definitiva, el conocimiento de los patrones de solapamiento interespecifico y del comportamiento intraespecifico en especies de ungulados en simpatria aporta informacion util para el manejo de sus poblaciones, asi como para la toma de decisiones en relacion a la gestion de especies exoticas.
A time series of infectious-like events in Australia between 2000 and 2013 leading to extended periods of increased deaths (all-cause mortality) with possible links to increased hospital medical admissions

Background and aims: Trends in deaths and medical admissions in the UK and Europe show evidence for a series of infectious-like events. These events have been overlooked by traditional surveillance methodologies. Preliminary evidence points to a rise in medical admissions in Australia around the same time as those observed in Europe, and this study was aimed to evaluate whether the deaths are occurred in similar way. Methods: Both monthly and annually deaths in the states of Australia and smaller local authority geographies were analyzed for evidence of large and abrupt step-like increases which endured for a minimum of 12 months. Monthly data were analyzed using a 12-month running total of deaths, while annual data compared one year to the next by converting changes in deaths into standard deviation equivalents in an assumed Poisson distribution. Results: At State and Local government level, there was evidence for spatial spread of an agent causing step-like changes in deaths which endured for 12 to 18 months before returning to the expected time-trajectory for deaths. The maximum step-like change ranged from 4.1% in New South Wales to 11.7% in the Northern Territory. The magnitude of the step-change was reduced with the size of the spatial geography and followed a power law function with size. Conclusion: The same events leading to increased deaths and medical admissions in the UK and Europe (Northern Hemisphere), also appeared to be operating in Australia (Southern Hemisphere) at roughly the same points in time. A common infectious source appeared to be implicated.