Miracle-dz/UniFAR-FTUs huggingface dataset:
Remarks on the ill-posedness of the Prandtl equation

In the lines of a recent paper by Gerard-Varet and Dormy, we establish various ill-posedness results for the Prandtl equation. By considering perturbations of stationary shear flows, we show that for some linearizations of the Prandtl equation and some $C^\infty$ initial data, local in time $C^\infty$ solutions do not exist. At the nonlinear level, we prove that if a flow exists in the Sobolev setting, it cannot be Lipschitz continuous. Besides ill-posedness in time, we also establish some ill-posedness in space, that casts some light on the results obtained by Oleinik for monotonic data.
Search for Gravitational Waves Associated with Gamma-Ray Bursts During the First Advanced LIGO Observing Run and Implications for the Origin of GRB 150906B

We present the results of the search for gravitational waves (GWs) associated with $\gamma$-ray bursts detected during the first observing run of the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO). We find no evidence of a GW signal for any of the 41 $\gamma$-ray bursts for which LIGO data are available with sufficient duration. For all $\gamma$-ray bursts, we place lower bounds on the distance to the source using the optimistic assumption that GWs with an energy of $10^{-2}M_\odot c^2$ were emitted within the $16$-$500\,$Hz band, and we find a median 90% confidence limit of 71$\,$Mpc at 150$\,$Hz. For the subset of 19 short/hard $\gamma$-ray bursts, we place lower bounds on distance with a median 90% confidence limit of 90$\,$Mpc for binary neutron star (BNS) coalescences, and 150 and 139$\,$Mpc for neutron star-black hole coalescences with spins aligned to the orbital angular momentum and in a generic configuration, respectively. These are the highest distance limits ever achieved by GW searches. We also discuss in detail the results of the search for GWs associated with GRB 150906B, an event that was localized by the InterPlanetary Network near the local galaxy NGC 3313, which is at a luminosity distance of 54$\,$Mpc ($z=0.0124$). Assuming the $\gamma$-ray emission is beamed with a jet half-opening angle $\leq 30^{\circ}$, we exclude a BNS and a neutron star-black hole in NGC 3313 as the progenitor of this event with confidence $>99$%. Further, we exclude such progenitors up to a distance of 102$\,$Mpc and 170$\,$Mpc, respectively.
Evolution of Flood Frequency Analysis with Bulletin 17

The current methodology recommended for flood-frequency analyses by U.S. Federal agencies is presented in Bulletin 17B. Bulletin 17 was first published in 1976, minor corrections were made in 1977 resulting in Bulletin 17A, which was later succeeded by Bulletin 17B published in 1982. Bulletin 17B sought to resolve ambiguities in the recommended procedures, including the treatment of low outliers, and the use of both regional skew and historical flood information. As the 25th anniversary of the publication of Bulletin 17B approaches, this paper provides a discussion and evaluation of the procedures that document recommends. The fields of hydrology and flood frequency analysis have substantially evolved since Bulletin 17 was first published. New techniques are now available which should become part of these standard procedures. A comparison is provided which demonstrates how the standard and weighted Bulletin 17B quantile estimators perform relative to alternative LP3 quantile estimators that also make use .
Determining Methods used in Teaching Geography in Secondary Schools in Rongo District, Kenya

This article dealt with methods of teaching Geography in Kenya but also the world over. The importance of Geography in secondary school curriculum cannot be overemphasized. Improving the performance of Geography education is a great societal need in Kenya not only for industrialization of the country as contained in the vision 2030 but also for ensuring food security in the country through practices like land reclamation and irrigation farming The objective of this article was; to find out the teaching methods used by various Geography teachers in secondary schools in Rongo district. The research question was: Which are the teaching methods used by secondary school Geography teachers in Rongo district? This study was guided by the B.F Skinner’s (1971) theory of Operant Conditioning which states that learning is based on consequences-reward. The respondent’s behaviour (R) is under the control of stimulus (S). It is therefore a process through which organisms learn to repeat behaviour that yields positive outcomes. The study adopted the descriptive survey design and targeted students taking Geography in the district. Female students were 302 while male students were 704 in secondary schools in Rongo District, Kenya. The study sample consisted of 308 students and 11 Geography teachers drawn from 11 secondary schools in Rongo district. The eleven schools is equivalent to thirty two per cent of secondary schools in Rongo district, which is considered statistically representative enough. Stratified random sampling was used to choose the schools to be included in the sample by using divisions as units of study. In order to identify the schools to be used from each division, simple random sampling was used. Purposive sampling was used to ensure that there is gender equity. The researcher used a questionnaire, observation and document content analysis as the main instruments for data collection. Data was collected using closed and open ended questionnaires. The questionnaires were pre-tested by being administered to 30 respondents from two schools which were not included in the study. The scores obtained from the first and second tests were 0.76 and 0.77 respectively. The descriptive statistics including percentages mean and frequency tables were used to analyse the data. Data was also analysed using the Statistical Package for Social Sciences (SPSS) version 15.0 computer programme.
COMPLEXITY IN THE RURAL CANADIAN HOUSING LANDSCAPE

Rural housing conditions and needs across Canada are as complex as the rural landscape itself, yet within the research literature rural housing is often treated as a single and unproblematic unit. This paper makes two arguments about rural housing research in Canada. The first is that the ‘rural’ is a complex housing landscape, not simply an undifferentiated ‘other’ in comparison to urban housing. The second is that this complexity has important implications for assessing changes to the local housing stock. The empirical content of the paper is drawn from three study areas in Canada where there is a mix of rural / agricultural and cottage area properties. Questions of housing stock change within these rural-recreational countryside examples are examined using questionnaire and building permit data. The findings presented here support the contention that the rural landscape is in fact a complex housing landscape, and also support the view that unless this complexity is recognized, a coherent portrait of rural housing will not emerge. Les conditions et les besoins d'habitations rurales au Canada, sont aussi complexes que le paysage lui-meme, meme si la litterature traite I'habitat rural en tant qu'unite“unique, denuee de problemes. Cet article presente deux arguments concernant la recherche sur I'habitat rural au Canada. En premier lieu, ‘rural’ decrit un paysage contenant des habitations complexes et pas simplement une ‘autre chose’ non-destincte par rapport a I'habitat urbain. Deuxidmement, cette complexite a des consequences importantes qui ont un rapport avec les changements dans I'inventaire local des habitations. Le contenu de l'article est base sur trois Etudes de cas au Canada ou il y a un melange de proprietes rurales, agricoles et vacancyeres. Les questions concernant le changement dans I'inventaire des habitations pour ces examples ruraux et vacanciers, sont reliees a des donnes de questionnaires et aux permis de construction. Les resultats presentes ici, confirment l'argument qu'un paysage rural est en fait un paysage complexe d'habitations. lis confirment aussi I'idee qu'un portrait coherent de I'habitat rural n'apparaitra pas, sauf si cette complexity est reconnue.
Analysis of atrazine and four degradation products in the pore water of the vadose zone, central Indiana

A new method is described for the analysis of atrazine and four of its degradation products (desethylatrazine, deisopropylatrazine, didealkylatrazine, and hydroxyatrazine) in water. This method uses solid-phase extraction on a graphitized carbon black cartridge, derivatization of the eluate with N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide (MTBSTFA), and analysis by gas chromatography/mass spectrometry (GC/MS). This method was used to analyze lysimeter samples collected from a field in central Indiana in 1994 and 1995. Atrazine and its degradation products were transported rapidly through the vadose zone. Maximum values of atrazine ranged from 2.61 to 8.44 μg/L and occurred from 15 to 57 days after application. Maximum concentrations of the degradation products occurred from 11 to 140 days after atrazine application. The degradation products were more persistent than atrazine in pore water. Desethylatrazine was the dominant degradation product detected in the first year, and didealkylatrazine wa.
Active Predicting Coding: Brain-Inspired Reinforcement Learning for Sparse Reward Robotic Control Problems

In this article, we propose a backpropagation-free approach to robotic control through the neuro-cognitive computational framework of neural generative coding (NGC), designing an agent built completely from powerful predictive coding/processing circuits that facilitate dynamic, online learning from sparse rewards, embodying the principles of planning-as-inference. Concretely, we craft an adaptive agent system, which we call active predictive coding (ActPC), that balances an internally-generated epistemic signal (meant to encourage intelligent exploration) with an internally-generated instrumental signal (meant to encourage goal-seeking behavior) to ultimately learn how to control various simulated robotic systems as well as a complex robotic arm using a realistic robotics simulator, i.e., the Surreal Robotics Suite, for the block lifting task and can pick-and-place problems. Notably, our experimental results demonstrate that our proposed ActPC agent performs well in the face of sparse (extrinsic) reward signals and is competitive with or outperforms several powerful backprop-based RL approaches.
Degrees $d \geqslant \big( \sqrt{n}\, \log\, n\big)^n$ and $d \geqslant \big( n\, \log\, n\big)^n$ in the Conjectures of Green-Griffiths and of Kobayashi

Once first answers in any dimension to the Green-Griffiths and Kobayashi conjectures for generic algebraic hypersurfaces $\mathbb{X}^{n-1} \subset \mathbb{P}^n(\mathbb{C})$ have been reached, the principal goal is to decrease (to improve) the degree bounds, knowing that the `celestial' horizon lies near $d \geqslant 2n$. For Green-Griffiths algebraic degeneracy of entire holomorphic curves, we obtain: \[ d \,\geqslant\, \big(\sqrt{n}\,{\sf log}\,n\big)^n, \] and for Kobayashi-hyperbolicity (constancy of entire curves), we obtain: \[ d \,\geqslant\, \big(n\,{\sf log}\,n\big)^n. \] The latter improves $d \geqslant n^{2n}$ obtained by Merker in arxiv.org/1807/11309/. Admitting a certain technical conjecture $I_0 \geqslant \widetilde{I}_0$, the method employed (Diverio-Merker-Rousseau, Berczi, Darondeau) conducts to constant power $n$, namely to: \[ d\ ,\geqslant\, 2^{5n} \qquad \text{and, respectively, to:} \qquad d \,\geqslant\, 4^{5n}. \] In Spring 2019, a forthcoming prepublication based on intensive computer explorations will present several subconjectures supporting the belief that $I_0 \geqslant \widetilde{I}_0$, a conjecture which will be established up to dimension $n = 50$.
First all-flavor search for transient neutrino emission using 3-years of IceCube DeepCore data

Since the discovery of a flux of high-energy astrophysical neutrinos, searches for their origins have focused primarily at TeV-PeV energies. Compared to sub-TeV searches, high-energy searches benefit from an increase in the neutrino cross section, improved angular resolution on the neutrino direction, and a reduced background from atmospheric neutrinos and muons. However, the focus on high energy does not preclude the existence of sub-TeV neutrino emission where IceCube retains sensitivity. Here we present the first all-flavor search from IceCube for transient emission of low-energy neutrinos, focusing on the energy region of 5.6-100 GeV using three years of data obtained with the IceCube-DeepCore detector. We find no evidence of transient neutrino emission in the data, thus leading to a constraint on the volumetric rate of astrophysical transient sources in the range of $\sim 705-2301\, \text{Gpc}^{-3}\, \text{yr}^{-1}$ for sources following a subphotospheric energy spectrum with a mean energy of 100 GeV and a bolometric energy of $10^{52}$ erg.
A global inventory of lakes based on high‐resolution satellite imagery

An accurate description of the abundance and size distribution of lakes is critical to quantifying limnetic contributions to the global carbon cycle. However, estimates of global lake abundance are poorly constrained. We used high‐resolution satellite imagery to produce a GLObal WAter BOdies database (GLOWABO), comprising all lakes greater than 0.002 km2. GLOWABO contains geographic and morphometric information for ~117 million lakes with a combined surface area of about 5 × 106 km2, which is 3.7% of the Earth's nonglaciated land area. Large and intermediate‐sized lakes dominate the total lake surface area. Overall, lakes are less abundant but cover a greater total surface area relative to previous estimates based on statistical extrapolations. The GLOWABO allows for the global‐scale evaluation of fundamental limnological problems, providing a foundation for improved quantification of limnetic contributions to the biogeochemical processes at large scales.
Equilibrium and transient global warming scenario implications for water resources in Wales

: A methodology has been developed to predict the responses of a range of water supply sources in Wales to global warming scenarios. Hydrologically effective rainfall is predicted from temperature and precipitation for each season based on site specific formulae developed using the Meteorological Office Rainfall and Evaporation Calculation System (MORECS) and UK Surface Water Archive databases. Comparisons are then made between the effects predicted for the scenarios established from equilibrium simulations and the new Hadley Centre High Resolution Model (UKHI) transient mode results. Though very different, both suggest increased stress on water resources late in the hydrological year.
Anomaly of heat content in the northern Atlantic in the last 7 years: Is the ocean warming or cooling?

Whether the North Atlantic Ocean is warming or cooling is an important question both in physical oceanography and climate change. The Argo profiling buoys provide an accurate and stable instrument for determining the tendencies in heat content from the surface to 2000 m from 1999 to 2005. To calculate temperature and heat content anomalies two reference climatologies are used. These are the well known WOA2001 climatology (Stephens et al., 2002), and a new WOCE Global Hydrographic climatology (Gouretski and Koltermann, 2004). The former climatology is used for our main results, and the latter is used for evaluating the sensitivity of our results to the climatology. Our scheme allows us to estimate the anomaly of heat content (AHC) in the North Atlantic and its smaller sub‐domains (i.e. 10° boxes) for the period 1999–2005. We have found a dipole structure in the time averaged AHC: negative values are concentrated in the southern and middle latitudes of the North Atlantic whilst positive values are found north of 50°N. The upper 1500 m of the North Atlantic is warming throughout the period 1999 to 2005.
Field-impressed anisotropies of magnetic susceptibility and remanence in minerals

The application of alternating (AF) or direct (DF) magnetic fields to samples containing dispersed particles of magnetite, titanomagnetite, or maghemite has been found to alter significantly the measured low-field susceptibility anisotropy even though the particle orientation is unchanged. The acquisition of isothermal remanent magnetization (IRM) is also strongly dependent on the previous AF treatment given to the samples. A method of quantifying the changes brought about by application of the fields is described. The samples studied were intrinsically isotropic or only weakly anisotropic, and the computed impressed susceptibility or IRM ellipsoids produced by the applied fields were ellipsoids of revolution with the unique axis aligned with the applied field axis. The size and shape of the field-impressed ellipsoids were strongly dependent upon particle size. These effects might thus form the basis of a rapid, nondestructive means of estimating particle size in rocks. The results also have important implications for magnetic fabric analysis and the static AF demagnetization of rocks. In particular, to ensure that the intrinsic magnetic fabric is measured without any field-impressed component of anisotropy, samples should not be subjected to static AF demagnetization prior to the determination of either low field susceptibility anisotropy or IRM anisotropy. Samples should also not carry a significant remanence (such as an IRM acquired in a field greater than about 5 mT) prior to low field susceptibility anisotropy analysis.
Geospatial-temporal analysis of land-use changes in the Yellow River Delta during the last 40 years

Comprehensive study on land-use change of spatial pattern and temporal process is the key component in land use/land cover changes (LUCC) study nowadays. According to the theories and methods of Geo-information Tupu (Carto-methodology in Geo-information, CMGI) for geospatial and temporal analysis and integration models of spatial pattern and temporal processes in GIS, the paper puts forward Tupu methodology of land-use change and names the basic synthetic unit of spatial-temporal information Tupu unit. Tupu unit is the synthetic unit for geospatial-temporal analysis, which is synthesized by “space·attribute·process” features and composed of relatively homogeneous geographic unit and temporal unit. Based on the spatial features of 4 stages of land-use change in 1956, 1984, 1991, and 1996, a series of Tupu on land-use change in the Yellow River Delta (YRD) are created and studied in the paper, which includes 3 temporal units of spatial-temporal Tupu, process Tupu of land-use changes during the last 40 years, and reconstructions of a series of “arisen” Tupu, “arisen” process Tupu and pattern Tupu on land-use changes in the last 40 years by remapping tables of a reclassifying system. There are 3 methods of Tupu analysis on land-use change that are used to disclose change processes of land-use spatial conversion in YRD, such as spatial query and statistics, order of Tupu units by area and land-use conversion matrixes. In order to reveal the spatial pattern of land-use change processes, we analyze spatial-temporal changes of each Tupu above in various temporal units and spatial difference of pattern Tupu in the last 40 years by dynamic Tupu units. Tupu analysis on regional land-use is a promising trial on the comprehensive research of “spatial pattern of dynamic process” and “temporal process of spatial pattern” in LUCC research. The geo-information Tupu methodology would be a powerful and efficient tool on integrated studies of spatial pattern and temporal process in geoscience.
Large 6300‐Å airglow intensity enhancements observed in Ionosphere Heating Experiments are excited by thermal electrons

It is shown that the 6300-A airglow intensity enhancements observed in ionosphere heating experiments, by high-power HF waves, which have been hitherto attributed to excitation by energetic electrons accelerated in plasma instabilities, are excited by energetic electrons from the tail of the heated thermal (maxwellian) electron gas. In addition, a plausible explanation for the inadequacy of the electron temperatures observed in the early ionosphere heating experiments at Arecibo to account for the observed oxygen red line enhancements is presented. In the light of these developments, electron acceleration in ionosphere HF heating experiments might be more scarce than is commonly believed.
The Shanderman eclogites: a Late Carboniferous high-pressure event in the NW Talesh Mountains (NW Iran)

Abstract The Shanderman Metamorphic Complex, exposed along the Caspian foothills of the Talesh Mountain, western Alborz, Iran, has always been interpreted as an ophiolitic fragment of the Palaeotethys Ocean. According to our new data, this unit consists of metamorphic rocks mainly represented by garnet–staurolite micaschists with large bodies of metabasites containing well-preserved eclogitic-phase assemblages. The Shanderman Complex (SC) was later intruded at middle crustal levels by intermediate–basic intrusive bodies. New Ar/Ar ages of paragonitic white micas in equilibrium with the high-pressure assemblages have given a Late Carboniferous age (315±9 Ma). Our new data suggest that the SC was equilibrated in high-pressure conditions during an orogenic event that predates the Eo-Cimmerian orogeny by more than 100 Ma and that may be tentatively ascribed to the Variscan orogeny sensu latu. We suggest that the Shanderman Complex represents a fragment of the Upper Palaeozoic European continental crust. The occurrence of eclogites in these regions can be explained by two different hypotheses: (1) the SC high-pressure rocks can be related to the accretion of Gondwana-related Transcauscasian–Moesian microplate to the southern margin of Eurasia; or (2) the SC eclogites can represent a fragment of the Late Palaeozoic ‘Variscan belt’ sensu latu of central Europe, which has been translated eastwards during Permian along a dextral megashear zone taking from a Pangea-B to a Pangea-A plate configuration. This metamorphic unit was stacked southwards on the northern edge of the Iran Plate during the Eo-Cimmerian events occurring at the end of the Triassic. The eclogite-bearing basement of the SC was finally exhumed at the end of the Eo-Cimmerian orogeny, as suggested by the composition of the basal layers of the Shemshak Group dated here Middle Jurassic, that cover the crystalline rocks of the SC along a regional non-conformity. The SC was probably displaced further southwards during the Mesozoic opening of the South Caspian Basin and the Tertiary thrust stacking and dextral shearing accompanying the formation of the Alborz intracontinental belt.
X ray and visible light transmission for laboratory measurement of two‐dimensional saturation fields in thin‐slab systems

Two independent techniques, X ray absorption and light transmission, are developed and demonstrated for imaging transient saturation fields in thin-slab porous systems. The techniques yield full two-dimensional saturation fields with high spatial and temporal resolution. In the time required to make a single measurement by one of the traditional methods (e.g., gravimetric or gamma densitometry) an entire image consisting of hundreds of thousands of points is acquired by either the X ray or light technique. These methods are also very sensitive, capable of resolving a hundred or more levels of saturation at each of these points. Evaluation of these techniques is accomplished by direct comparison of X ray and light data as well as comparison with gravimetric and gamma densitometry data. Results of the comparison show very close agreement between the four techniques (on average within 5% saturation). These techniques represent useful tools for investigating processes governing unsaturated flow and transport through porous media.