Miracle-dz/UniFAR-FTUs huggingface dataset:
The VLT-FLAMES Tarantula Survey. XIII: On the nature of O Vz stars in 30 Doradus

Context. O Vz stars, a subclass of O-type dwarfs characterized by having He ii λ4686 stronger in absorption than any other helium line in their blue-violet spectra, have been suggested to be on or near the zero-age main sequence (ZAMS). If their youth were confirmed, they would be key objects with which to advance our knowledge of the physical properties of massive stars in the early stages of their lives. Aims. We test the hypothesis of O Vz stars being at a different (younger) evolutionary stage than are normal O-type dwarfs. Methods. We have performed the first comprehensive quantitative spectroscopic analysis of a statistically meaningful sample of O Vz and O V stars in the same star-forming region, exploiting the large number of O Vz stars identified by the VLT-FLAMES Tarantula Survey in the 30 Doradus region of the Large Magellanic Cloud (LMC). We obtained the stellar and wind parameters of 38 O Vz stars (and a control sample of 46 O V stars) using the FASTWIND stellar atmosphere code and the IACOB-GBAT, a grid-based tool developed for automated quantitative analysis of optical spectra of O stars. In the framework of a differential study, we compared the physical and evolutionary properties of both samples, locating the stars in the log g vs. log Teff, log Q vs. log Teff, and log L/L⊙ vs. log Teff diagrams. We also investigated the predictions of the FASTWIND code regarding the O Vz phenomenon. Results. We find a differential distribution of objects in terms of effective temperature, with O Vz stars dominant at intermediate values. The O Vz stars in 30 Doradus tend to be younger (i.e., closer to the ZAMS) and less luminous, and they have weaker winds than the O V stars, but we also find examples with ages of 2−4 Myr and with luminosities and winds that are similar to those of normal O dwarfs. Moreover, the O Vz stars do not appear to have higher gravities than the O V stars. In addition to effective temperature and wind strength, our FASTWIND predictions indicate how important it is to take other stellar parameters (gravity and projected rotational velocity) into account for correctly interpreting the O Vz phenomenon. Conclusions. In general, the O Vz stars appear to be on or very close to the ZAMS, but there are some examples where the Vz classification does not necessarily imply extreme youth. In particular, the presence of O Vz stars in our sample at more evolved phases than expected is likely a consequence of modest O-star winds owing to the low-metallicity environment of the LMC.
VERTICAL TEMPERATURE, THE FATE OF UP WELLING AND SPATIAL DISTRIBUTION OF FISH BIOMASS OF NORTH PAPUA WATERS

The increasing need to introduce and highlight the analysis of deep water temperature (both horizontal and vertical) profile for up welling process and its relationship to fish biomass spatial distribution was inevitable. Especially to avoid the misleading interpretation of using only surface water temperature data for deep water fish biomass analysis. The paper analyze and revealed the fate / occurrence of up welling zone in adjacent of Halmahera islands through the analysis of both multi-layer horizontal and vertical temperature data. Further analysis on the temperature and fish biomass data revealed the close relationship of horizontal temperature pattern especially at depth of 80m with spatial distribution of total fish biomass (acoustic numeric data : in dB unit) and fish biomass (ton/mile square) with fish total-length above 30cm.
Anthropogenic and climatic influences on carbon fluxes from eastern North America to the Atlantic Ocean: A process‐based modeling study

The magnitude, spatiotemporal patterns, and controls of carbon flux from land to the ocean remain uncertain. Here we applied a process‐based land model with explicit representation of carbon processes in streams and rivers to examine how changes in climate, land conversion, management practices, atmospheric CO2, and nitrogen deposition affected carbon fluxes from eastern North America to the Atlantic Ocean, specifically the Gulf of Maine (GOM), Middle Atlantic Bight (MAB), and South Atlantic Bight (SAB). Our simulation results indicate that the mean annual fluxes (±1 standard deviation) of dissolved organic carbon (DOC), particulate organic carbon (POC), and dissolved inorganic carbon (DIC) in the past three decades (1980–2008) were 2.37 ± 0.60, 1.06 ± 0.20, and 3.57 ± 0.72 Tg C yr−1, respectively. Carbon export demonstrated substantial spatial and temporal variability. For the region as a whole, the model simulates a significant decrease in riverine DIC fluxes from 1901 to 2008, whereas there were no significant trends in DOC or POC fluxes. In the SAB, however, there were significant declines in the fluxes of all three forms of carbon, and in the MAB subregion, DIC and POC fluxes declined significantly. The only significant trend in the GOM subregion was an increase in DIC flux. Climate variability was the primary cause of interannual variability in carbon export. Land conversion from cropland to forest was the primary factor contributing to decreases in all forms of C export, while nitrogen deposition and fertilizer use, as well as atmospheric CO2 increases, tended to increase DOC, POC, and DIC fluxes.
Holocene glacier variation chronology of the Smørstabbtindan massif, Jotunheimen, southern Norway, and the recognition of century- to millennial-scale European Neoglacial Events

New stratigraphic evidence for the Holocene history of three glaciers in central Jotunheimen, southern Norway, is presented and the implications for century- to millennial-scale glacier and climatic variability are considered. Minerogenic layers in seven stream-bank mires, flooded episodically by glaciofluvial meltwater, are dated by 79 new radiocarbon age estimates. A revised chronology for glacier variations in Smørstabbtindan suggests a three-phase Holocene: (1) an early-Holocene deglaciation phase (11500—9500 cal. BP) characterized by readvances of ice-sheet remnants; (2) a mid-Holocene phase with relatively small or absent glaciers (9500—5000 cal. BP); and (3) a late-Holocene phase of enlarged and fluctuating glaciers (the last 5000 years). Seven millennial-scale neoglacial events (Smørstabbtindan I—VII), during which glaciers were larger than at present for most of the time, are dated to: >10 400—9600 (Erdalen Event), 8400—7650 (Finse Event), 4800—3900, 3200—2550, 2350—1700, 1400—750 and 500—0 cal. BP (`Little Ice Age'). Two or more century-scale events are nested within each millennial-scale event. Based on the timing of neoglacial maxima, the record from Smørstabbtindan is combined with comparable reconstructions from southern Norway to indicate at least 17 century- to millennial-scale Southern Norwegian Neoglacial Events. A similar approach to records from the Swiss and Austrian Alps identifies around 23 Alpine Neoglacial Events. This leads to the recognition of 13 European Neoglacial Events that are at least continental in extent but seem to be imperfectly correlated with episodes of low solar irradiance, which suggests that other climatic forcing factors are also involved, including volcanic aerosols and, in the early Holocene, freshwater outbursts into the northern Atlantic Ocean. Local to regional patterns in glacier behaviour, particularly in relation to century-scale events, may be accounted for by differences in glacier size and geometry, topography and atmospheric circulation patterns; whereas the three Holocene multimillennial phases appear to reflect the Earth's orbital variations.
Understanding the contrasting North Atlantic Oscillation anomalies of the winters of 2010 and 2014

The present study investigates the two contrasting winters of 2010 and 2014 during which the North Atlantic Oscillation (NAO) was mainly negative and positive, respectively. In the North Pacific, contrasting anomalies were also present, with a straight zonal Pacific jet in 2010 and a strong poleward deviation of the Pacific jet in its exit region in 2014. Using reanalysis data sets and adopting a nonlinear initial‐value approach with a quasi‐geostrophic model, we show that the Pacific‐North American anomalies are responsible for shaping synoptic wave trains propagating across North America. This in turn largely determines the nature of wave breaking and the synoptic eddy feedback onto the mean flow in the North Atlantic and finally the NAO phase. In such a proposed mechanism, synoptic wave activity forms the cornerstone of the dynamical relationship between the North Pacific and North Atlantic large‐scale anomalies during the contrasting winters of 2010 and 2014.
Low Cost, Open-Source Testbed to Enable Full-Sized Automated Vehicle Research

An open-source vehicle testbed to enable the exploration of automation technologies for road vehicles is presented. The platform hardware and software, based on the Robot Operating System (ROS), are detailed. Two methods are discussed for enabling the remote control of a vehicle (in this case, an electric 2013 Ford Focus). The first approach used digital filtering of Controller Area Network (CAN) messages. In the case of the test vehicle, this approach allowed for the control of acceleration from a tap-point on the CAN bus and the OBD-II port. The second approach, based on the emulation of the analog output(s) of a vehicle's accelerator pedal, brake pedal, and steering torque sensors, is more generally applicable and, in the test vehicle, allowed for the full control vehicle acceleration, braking, and steering. To demonstrate the utility of the testbed for vehicle automation research, system identification was performed on the test vehicle and speed and steering controllers were designed to allow the vehicle to follow a predetermined path. The resulting system was shown to be differentially flat, and a high level path following algorithm was developed using the differentially flat properties and state feedback. The path following algorithm is experimentally validated on the automation testbed developed in the paper.
Management of point source discharges into rivers: Where do environmental quality standards in the new EC‐water framework directive apply?

Abstract The “combined approach” in the new EC‐Water Framework Directive (WFD) consisting of environmental quality standards in addition to emission limit values promises improvements in the quality characteristics of surface waters. However, the specification of where in the water body the environmental quality standards apply is missing in the WFD. This omission will limit its administrative implementation. A clear mixing zone regulation is needed so that the quality objectives of the WFD are not jeopardized. This need is demonstrated using the examples of point source discharges into rivers. Furthermore, water authorities will have to make increased use of predictive modeling techniques for the implementation of the “combined approach”.
Monthly gravity field models derived from GRACE Level 1B data using a modified short‐arc approach

In this study, a new time series of Gravity Recovery and Climate Experiment (GRACE) monthly solutions, complete to degree and order 60 spanning from January 2003 to August 2011, has been derived based on a modified short‐arc approach. Our models entitled Tongji‐GRACE01 are available on the website of International Centre for Global Earth Models (http://icgem.gfz-potsdam.de/ICGEM/). The traditional short‐arc approach, with no more than 1 h arcs, requires the gradient corrections of satellite orbits in order to reduce the impact of orbit errors on the final solution. Here the modified short‐arc approach has been proposed, which has three major differences compared to the traditional one: (1) All the corrections of orbits and range rate measurements are solved together with the geopotential coefficients and the accelerometer biases using a weighted least squares adjustment; (2) the boundary position parameters are not required; and (3) the arc length can be extended to 2 h. The comparisons of geoid degree powers and the mass change signals in the Amazon basin, the Antarctic, and Antarctic Peninsula demonstrate that our model is comparable with the other existing models, i.e., the Centre for Space Research RL05, Jet Propulsion Laboratory RL05, and GeoForschungsZentrum RL05a models. The correlation coefficients of the mass change time series between our model and the other models are better than 0.9 in the Antarctic and Antarctic Peninsula. The mass change rates in the Antarctic and Antarctic Peninsula derived from our model are −92.7 ± 38.0 Gt/yr and −23.9 ± 12.4 Gt/yr, respectively, which are very close to those from other three models and with similar spatial patterns of signals.
A late Middle Devensian interstadial site at Sourlie, near Irvine, Strathclyde

Sourlie, near Irvine (Fig. 1), is certainly one of the few and probably the only site in the whole of Scotland where, to date, irrefutable stratigraphical evidence demonstrates that during the Quaternary period the country was subjected to glaciation in both Late Devensian and pre-Late Devensian times (cf. Mitchell et al. 1973; Lowe 1984; Bowen et al. 1986, pp. 320–3; Bowen and Sykes 1988). The relevant field evidence, preliminary results of laboratory analysis and some conclusions concerning the significance of the site at Sourlie are presented below. Temporary, open-cast coal excavations at Sourlie in 1986 exposed thin (to 0.6 m) lenses of organic-rich sediments (unit D1, Table 1 and Fig. 2) contained within local pockets on the upper surface of a layer of glacio-fluvial deposits (C). The latter sediments overlie an ablation deposit (B), which rests on a basal grey lodgement till (A) that contains clasts of (mainly) local sedimentary rocks. Units D1 and D2 are overlain by two distinctly different deposits. The lower of these, a thinly developed pink-brown diamicton (E), contains a mixture of clasts of local and far-travelled sedimentary, igneous and metamorphic rocks, together with occasional fragments and rare complete valves of marine molluscs. The overlying, thicker, upper grey lodgement till (F) is devoid of shell fragments. In grain-size characteristics, clay mineralogy and geochemistry its matrix closely resembles that of unit A, but, in addition to containing clasts of local sedimentary rocks, unit F contains basic igneous rock fragments that have been transported at least a .
Snow depth controls palsa growth

When a young palsa has risen sufficiently above a mire (bog) and has developed steep sides, drifting snow collects against these sides and inhibits freezing of adjacent ground. Measurement of the temperature regime on the top surface, and at the foot, of the northern edge of a 2.6 m high palsa in Utsjoki, Finland supports this hypothesis. The minimum temperature recorded in the winter of 1992–93 on the uncovered palsa summit was −23.4°C. After snowfall, the temperature stayed at +0.1°C at the foot of the palsa for over six months, until 20 June 1993. At the edge of the palsa, thick snow cover prevents the establishment of permafrost. Quand une jeune palse s'est elevee assez au dessus d'un marais pour que ses flancs soient en forte pente, la neige remaniee par le vent est accumulee contre ses flancs raides et empěche le gel du sol voisin. Des mesures de temperature sur la surface et au pied de la bordure septentrionale d'une palse haute de 2,60m a Utsjoki (Finlande) confirment cette hypothese. La temperature minimum enregistree lors de l'hiver 1992–1993 sur le sommet decouvert de la palse a ete de −23,4°C. Apres des chutes de neige, la temperature est restee a +0,1°C au pied de la palse pendant plus de 6 mois jusqu'au 20 juin 1993. En bordure de la palse, l'epaisse couverture de neige empěche la formation du pergelisol.
Absorption of light in the atmosphere by collision pairs of oxygen (O2)2

Atmospheric absorption bands by collision complexes of oxygen have been measured in long path optical experiments. About 1.5×10−3 of the incoming solar energy is absorbed by the O4 bands in the near uv, visible and near infrared spectral regions. A larger fraction of this energy goes into the 2 km layer above the surface. The possible consequences of excited metastable (O2)2 molecules for atmospheric chemistry are discussed.
The distribution of stress and velocity in glaciers and ice-sheets

A block of ice resting upon a rough slope forms a theoretical model of a glacier or an ice-sheet, the sides of the glacier valley being ignored. Previous papers have described two types of steady flow in this model: (a) laminar flow, in which the longitudinal velocity gradient r is zero, and (b) extending or compressive flow, in which r is non-zero, (a) was derived under the assumption of a general flow law for ice, but (b) was only derived under the assumption of perfect plasticity. In the present paper a general flow law is used throughout, and the equations for steady flow, with r allowed to be non-zero, are found. The previous results (a) and (b) appear as special cases. Possible variations of density, temperature or flow law with depth are allowed for. If the density and the flow law are known as functions of depth in any region, and if the surface slope, the surface velocity, and the value of r are known, the equations give the stresses and velocity as functions of depth. The borehole experiment on the Jungfraufirn (1948-50) allows an experimental test. From the observed value of r, and Glen’s laboratory flow law for ice, a theoretical curve for the result of the experiment is calculated which is compared with the experimental curve. At a depth of 50 m the effect of ignoring r, as has been done hitherto, is to underestimate the shear rate by a factor of 50; on the present theory it is overestimated by a factor of 1∙33. The remaining discrepancy is probably mainly due to the effect of the glacier sides.
A new crocodylian (Archosauria) from the basal Paleocene of the Red Deer River Valley, southern Alberta

Borealosuchus griffithi, sp. nov., is described on the basis of an incomplete skeleton from the basal Paleocene, southern Alberta. This new species records one of a few basal Cenozoic occurrences of Crocodylia so far known. B. griffithi is most distinctive in having a markedly laterally concavo-convex snout; a deep, elongate recess or fossa on the anteroventral surface of the jugal; and a large, nearly rectangular incisive foramen. Within Borealosuchus, B. griffithi probably takes a "more crownward" position than does B. sternbergii of the late Late Cretaceous. With additional information from the new species, the diagnosis of Borealosuchus is revised.
Variants of Wilson's functional equation on semigroups.

Given a semigroup $S$ generated by its squares equipped with an involutive automorphism $\sigma$ and a multiplicative function $\mu:S\to\mathbb{C}$ such that $\mu(x\sigma(x))=1$ for all $x\in S$, we determine the complex-valued solutions of the following functional equations \begin{equation*}f(xy)+\mu(y)f(\sigma(y)x)=2f(x)g(y),\, x,y\in S\end{equation*} and \begin{equation*}f(xy)+\mu(y)f(\sigma(y)x)=2f(y)g(x),\, x,y\in S\end{equation*}
Lowest-Low Fertility: Signs of a recovery in Italy?

This study aims to describe the process of birth postponement and recovery in Italy, a country with persistent very low fertility levels. The case of Italy is particularly significant given that this country carries great demographic weight in "Southern Europe"; an area characterized by cultural and institutional specificities which have important implications for the timing of family formation and the final number of children. We use data recently published by the Italian National Institute of Statistics (Istat), applying a cohort approach to show changes in CTFRs and the timing of births for the 1950-1980 cohorts. In order to further evaluate the evolution of Italian “fertility ageing” across social groups (with a focus on female education) we also use individual level data from the 2003 Istat multipurpose survey “Famiglia e soggetti sociali”. We find that a recovery is presently in progress in the northern regions of Italy, even if not all postponed births are recovered. As expected, signs of recovery are above all evident among the youngest generations and more educated women.
Elastic, vibrational, and thermodynamic properties of MgGeO3 postperovskite investigated by first principles simulation

[1] Elastic, vibrational and thermodynamic properties of MgGeO3 perovskite (Pv) and postperovskite (PPv) were calculated based on the density functional first principles methods. We found that the calculated properties of MgGeO3 are quite similar to those of MgSiO3 in particular for anomalously large c66 and small c55 of PPv, but not fully comparable in particular for the velocity contrasts across the phase change, which are all negative in compressional, shear and bulk velocities at the transition pressure unlike the typical features of the D″ seismic discontinuity. MgGeO3 PPv has larger elastic anisotropy than MgSiO3, but their style is quite similar. Significant orientational preference is needed for PPv polycrystalline aggregate to reproduce seismic shear wave polarization anisotropy observed in D″ except for a case with the c direction aligned vertically. Lattice dynamics calculations indicate that the both phases are vibrationally stable under high pressure, and quasi-harmonic thermodynamics provides the Clapeyron slope of PPv phase boundary of ∼+7.8 MPa/K, which is quite comparable to that reported for MgSiO3. While the calculated Raman frequencies are in excellent agreement with experimental values in Pv, those are found less consistent in PPv.
Herschel observations of water vapour in Markarian 231

The Ultra luminous infrared galaxy (ULIRG) Mrk 231 reveals up to seven rotational lines of water (H2O) in emission, including a very high-lying (Eupper = 640 K) line detected at a 4 sigma level, within the Herschel/SPIRE wavelength range (190 < lambda(mu m) < 640), whereas PACS observations show one H2O line at 78 mu m in absorption, as found for other H2O lines previously detected by ISO. The absorption/emission dichotomy is caused by the pumping of the rotational levels by far-infrared radiation emitted by dust, and subsequent relaxation through lines at longer wavelengths, which allows us to estimate both the column density of H2O and the general characteristics of the underlying far-infrared continuum source. Radiative transfer models including excitation through both absorption of far-infrared radiation emitted by dust and collisions are used to calculate the equilibrium level populations of H2O and the corresponding line fluxes. The highest-lying H2O lines detected in emission, with levels at 300-640 K above the ground state, indicate that the source of far-infrared radiation responsible for the pumping is compact (radius = 110-180 pc) and warm (T-dust = 85-95 K), accounting for at least 45% of the bolometric luminosity. The high column density, N(H2O) similar to 5 x 10(17) cm(-2), found in this nuclear component, is most probably the consequence of shocks/cosmic rays, an XDR chemistry, and/or an "undepleted chemistry" where grain mantles are evaporated. A more extended region, presumably the inner region of the 1-kpc disk observed in other molecular species, could contribute to the flux observed in low-lying H2O lines through dense hot cores, and/or shocks. The H2O 78 mu m line observed with PACS shows hints of a blue-shifted wing seen in absorption, possibly indicating the occurrence of H2O in the prominent outflow detected in OH (Fischer et al. 2010, A&A, 518, L41). Additional PACS/HIFI observations of H2O lines are required to constrain the kinematics of the nuclear component, as well as the distribution of H2O relative to the warm dust.