Miracle-dz/UniFAR-FTUs huggingface dataset:
Acoustic propagation in a vortical homentropic flow

This paper is devoted to the theoretical and the numerical studies of the radiation 4 of an acoustic source in a general homentropic flow. As a linearized model, we consider Goldstein's 5 Equations, which extend the usual potential model to vortical flows. The equivalence between 6 Linearized Euler's Equations with general source terms and Goldstein's Equations is established, 7 and the relations between unknowns, in each model, are analysed. A closed-form relation between 8 the hydrodynamic phenomena and the acoustics is derived. Finally, numerical results are presented 9 and the relevance of using Goldstein's Equations compared to the potential model is illustrated.
Initial trials of convective‐scale data assimilation with a cheaply tunable ensemble filter

Ensemble methods are an attractive option for data assimilation (DA) in convection‐permitting models, providing flow‐dependent covariances which respect the complex balances that apply at these scales. The Met Office deterministic UK forecast currently uses variational assimilation based on predominantly climatological covariances, whilst the MOGREPS‐UK ensemble interpolates its initial perturbations from the corresponding global members. An experimental convective‐scale ensemble DA system has now been built based on a serial ensemble filter, where observations are assimilated sequentially. This has been tested in a series of one month trials assimilating sonde, surface and aircraft observations, exploring issues such as cycle length, filter type, localization and inflation. The tests use 44 perturbed ensemble members, plus an unperturbed control forecast that is updated using the same Kalman gain as the ensemble mean. The best configurations provide control forecasts which are competitive with interpolating global initial states like MOGREPS‐UK did at the time, even though the local assimilation has seen fewer observation types than the global DA. An hourly cycle performs much better than a 6‐hourly one, as suggested by theoretical arguments, even though both see the same boundary conditions and essentially the same total set of observations.
Design , characterization , in vitro antibacterial , antitubercular evaluation and structure – activity relationships of new hydrazinyl thiazolyl coumarin derivatives

Herein, we describe the synthesis of 11new thiazolyl coumarin derivatives and evaluation of their potential role as antibacterial and antituberculosis agents. The structures of the synthesized compounds were established by extensive spectroscopic studies (Fourier transform infrared spectroscopy, H-nuclear magnetic resonance, Cnuclear magnetic resonance, 2D-nuclear magnetic resonance and liquid chromatography–mass spectrometry) and elemental analysis. All synthesized compounds were assayed for their in vitro antibacterial activity against a few gram positive and gram negative bacteria and antituberculosis activity against Mycobacterium tuberculosis H37Rv ATCC 25618 by using colorimetric microdilution assay method. Nine derivatives showed moderate antibacterial and anti-tuberculosis activities against all the tested strains. The highest activity against all the pathogens including Mycobacterium tuberculosis was observed by compound 7c with MIC values ranging between 31.25–62.5 μg/mL, indicating that coumarin skeleton could indeed provide useful scaffold for the development of new anti-microbial drugs.
Source and coefficient identification problems for the wave equation on graphs

Avdonin and Kurasov proposed a leaf peeling method based on the boundary control to recover a potential for the wave equation on a tree. Avdonin and Nicaise considered a source identification problem for the wave equation on a tree. This paper extends the methodology to the wave equation with unknown potential and source distributed parameters defined on a general tree graph.
Distributed adaptive output consensus control of a class of uncertain nonlinear multiagents systems

This paper addresses the leader‐follower output consensus problem for a class of uncertain nonlinear multiagent systems in a directed communication topology. By employing the backstepping method, the dynamic surface control technique, neutral networks, and the graph theory, a distributed adaptive control scheme is developed recursively for each follower using its own and neighbors' information. The key features of this strategy are that it reduces the computational burden by introducing the dynamic surface control approach and there is no requirement for a priori knowledge about uncertain dynamics of the system. Moreover, in theory, it is proved that the designed control approach can steer the output signals of followers in a directed graph to track the desired trajectory of the leader and guarantee all signals in the closed‐loop system cooperatively semiglobally uniformly ultimately bounded. Furthermore, two examples are included, and the simulation results demonstrate the effectiveness of the proposed strategy.
Hyperbolic hypergeometric monodromy groups and geometric finiteness

The subject of this thesis is hyperbolic hypergeometric monodromy groups. I studied the monodromy groupsH(α, β) for nFn−1 hypergeometric differential equation Du = 0, where D = (θ+β1−1) · · · (θ+βn−1)−z(θ+α1) · · · (θ+αn) and θ = z d dz , α, β ∈ Q. H(α, β) is generated by the local monodromies A,B,C which correspond to 0, 1,∞ respectively. Let G is the zariski closure of H(α, β). In the self-dual case, G is either finite, Sp(n), or O(n). I focus on G orthogonal and of signature (n − 1, 1) over R. The first result is that the odd hyperbolic hypergeometric monodromy groups H(α, β) are of infinite index in G(Z). In this case H(α, β) is called ’thin’, which is equivalent to saying that the fundamental domain has infinite volume. It was shown that there are three families of odd hyperbolic hypergeometric monodromy groups, and we show that H(α, β) is thin for all but one case by showing that a finite index subgroup of H(α, β) is commensurable with a reflection subgroup of an infinite index subgroup of G(Z). In the remaining case, I used an algorithm from [5] to show that the fundamental domain for a finite index reflection subgroup of H(α, β) is thin. This covers the second chapter. In the third chapter, I investigated the full reflection subgroup of G(Z), the 2reflection subgroup containing all 2-reflections, and H(α, β). When Γ be one of them, I looked at limit set Λ(Γ), the exponent of divergence δ(Γ) of the Poincare series, and the bottom of the spectrum of the Laplacian on L2(Γ\Hn−1). The second result is ’geometric finiteness’ for discrete groups generated by finitely many reflections, which means its fundamental domain has finitely many faces. It follows that H(α, β)’s which were shown to be thin in [5] and in the second chapter are not only thin, but have ’sparse’ limit sets. In the last chapter, the first example for which the monodromy group is geometrically finite and thin is given. I found a fundamental domain using numerical com-
On the $U_p$ operator acting on $p$-adic overconvergent modular forms when $X_0(p)$ has genus 1

In this article we will show how to compute $U_p$ acting on spaces of overconvergent $p$-adic modular forms when $X_0(p)$ has genus 1. We first give a construction of Banach bases for spaces of overconvergent $p$-adic modular forms, and then give an algorithm to approximate both the characteristic power series of the $U_p$ operator and eigenvectors of finite slope for $U_p$, and present some explicit examples. We will also relate this to the conjectures of Clay on the slopes of overconvergent modular forms.
UvA-DARE ( Digital Academic Repository ) Herbivory and dominance shifts among exotic and congeneric native plant species during plant community establishment

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Elastic least-squares reverse time migration with hybrid l1/l2 misfit function

ABSTRACT We have developed the theory and synthetic tests of elastic least-squares reverse time migration (ELSRTM). In this method, a least-squares reverse time migration algorithm is used to image multicomponent seismic data based on the first-order elastic velocity-stress wave equation, in which the linearized elastic modeling equations are used for forward modeling and its adjoint equations are derived based on the adjoint-state method for back propagating the data residuals. Also, we have developed another ELSRTM scheme based on the wavefield separation technique, in which the P-wave image is obtained using P-wave forward and adjoint wavefields and the S-wave image is obtained using P-wave forward and S-wave adjoint wavefields. In this way, the crosstalk artifacts can be minimized to a significant extent. In general, seismic data inevitably contain noise. We apply the hybrid l1/l2 misfit function to the ELSRTM algorithm to improve the robustness of our ELSRTM to noise. Numerical tests on synthetic dat.
Emergence of cosmic space in Tsallis modiﬁed gravity from equilibrium and non-equilibrium thermodynamic perspective

The profound connection between the law of emergence and the thermodynamic laws provides a new thermodynamic perspective on the accelerated expansion of the universe. In this paper, we explore this connection in the context of Tsallis entropy in both equilibrium and non-equilibrium perspectives. From an equilibrium perspective, we derive the law of emergence by considering Tsallis entropy as the horizon entropy from the uniﬁed ﬁrst law of thermodynamics and the Clausius relation and is found to be consistent with the earlier proposals [1, 2]. However, when one uses Tsallis entropy as the horizon entropy, the thermal evolution of the system becomes non-equilibrium [3], which results in the generation of additional entropy, and the ﬁrst law of thermodynamics will get modiﬁed accordingly compared to its usual equilibrium version. We obtained the law of emergence from this modiﬁed form of the ﬁrst law of thermodynamics. The law of emergence thus obtained have a simple form, which explains the emergence of the universe, in terms of the rate of change of the areal volume of the horizon, instead of the eﬀective volume as in the equilibrium case. We have further shown that the law of emergence also satisﬁes the condition of the maximization of entropy; thus, the entropy of the universe evolves to a bounded value in the asymptotic future.
Effect of Background Synaptic Activity on Excitatory-Postsynaptic Potential-Spike Coupling

Neurons receive large amount of synaptic inputs n vivo, which may impact the coupling between EPSPs and spikes. We mimicked the in vivo synaptic activity of the cell with the dynamic clamp system. We recorded from pyramidal cells in neocortical slices in vitro to investigate how timing and probability of spike generation in response to an EPSP is affected by background synaptic conductance under these conditions. We found that near threshold, background synaptic conductance improved the precision of spike timing by reducing the depolarization-related prolongation of the EPSP. In cells with ongoing spike activity and background synaptic conductances, an EPSP rapidly increased the probability of firing. The time window of the spike probability increase was comparable to the EPSP rise time and was followed by a long period of reduced firing. We found that the net synaptic gain was determined not only by the amplitude of the EPSP, but also by the firing frequency of the cell. In addition, a background fluctuating conductance reduced the time window of perturbation of spike patterns generated by EPSP related spikes. Taken together, these results indicate that in vivo, the level of the background synaptic activity may regulate spike-timing precision and affect synaptic gain.
Learning Probabilistic Rules from Experience

Before we attempt to design algorithms for learning first-order models, it is important to understand the propositional case. In a propositional model, states of the world are described by state variables (also sometimes called aspects or fluents). The state variables in a factory control domain might be, for example, the temperature and pressure at different points in the factory. It is popular to represent probabilistic propositional models of the world dynamics as dynamic Bayesian networks (dbns). dbns consist of two parts: a graph and a set of probability tables. The graph encodes the dependence relationships between the state variables at some generic time t and the state variables on the next time step, t + 1. The tables encode the conditional probability distributions describing exactly how the value of a variable depends on its parents in the graph. (For more detail, see Dean and Kanazawa (1989). ) dbns (and Bayesian networks, in general) have been successful representationally because they take advantage of the fact that in most large domains, not all variables are dependent on all others. By making independence an unstated default, dbns often provide very compact representations of complex domains. In this project, we are going to explore an alternative, rule-based representation language, inspired by the work of Drescher (1991). There are two reasons for this shift. First, we believe that rules will, in general, provide an even more compact representation of typical dynamic domains. Second, it seems more straightforward to to extend a rule-based representation to the first-order case. Our rules will be of the form P a,p −→ Q, with approximate semantics: if P is true at time t, R is false at time t, and action a is taken, then R will be true at time t + 1 with probability p. There is a major implicit default assumption here: If there is no rule to indicate otherwise, then state variables retain their values over time. This is the solution
Land of Addicts? An Empirical Investigation of Habit-Based Asset Pricing Models

A popular explanation of aggregate stock market behavior suggests that assets are priced as if there were a representative investor whose utility is a power function of the di¤erence between aggregate consumption and a habit level, where the habit is some function of lagged and (possibly) contemporaneous consumption. But theory does not provide precise guidelines about the parametric functional relationship between the habit and aggregate consumption. This makes formal estimation and testing challenging; at the same time, it raises an empirical question about the functional form of the habit that best explains asset pricing data. This paper studies the ability of a general class of habit-based asset pricing models to match the conditional moment restrictions implied by asset pricing theory. Our approach is to treat the functional form of the habit as unknown, and to estimate it along with the rest of the models nite dimensional parameters. This semiparametric approach allows us to empirically evaluate a number of interesting hypotheses about the speci cation of habit-based asset pricing models. Using stationary quarterly data on consumption growth, assets returns and instruments, our empirical results indicate that the estimated habit function is nonlinear, the habit formation is internal, and the estimated time-preference parameter and the power utility parameter are sensible. In addition, our estimated habit function generates a positive stochastic discount factor (SDF) proxy and performs well in explaining cross-sectional stock return data . We nd that an internal habit SDF proxy can explain a cross-section of size and book-market sorted portfolio equity returns better than (i) the Fama and French (1993) three-factor model, (ii) the Lettau and Ludvigson (2001b) scaled consumption CAPM model, (iii) an external habit SDF proxy, (iv) the classic CAPM, and (v) the classic consumption CAPM. JEL: G12, C14, C52
Continuous higher order sliding mode observers for a class of uncertain nonlinear systems

Two nonlinear state observers are proposed to reconstruct the system states for a class of uncertain nonlinear systems. Both state observers are designed based on continuous higher order sliding mode and terminal sliding mode concepts. The proposed observers are chattering-free and constructed without any detailed model knowledge of the system. Desirable features of the proposed observers include that they are immune to noise and can be designed separately from a controller. Lyapunov stability theory is employed to prove the finite-time convergent and uniformly ultimately bounded observation. Simulation results are provided to demonstrate the effectiveness and improved performance of the developed observers.
Les normes fondamentales du travail contribuent-elles à réduire les inégalités ?

Cet article propose une investigation empirique des liens qu’entretiennent normes sociales et inegalite de revenus. Dans un premier temps, un indice de normes sociales du travail (travail des enfants, travail force, discrimination, liberte syndicale, conventions OIT) est determine. Aucun lien n’est trouve a priori avec l’inegalite. Ceci s’explique par la difference entre la ratification des traites internationaux sur les normes sociales et la mise en place effective de ces normes par les pays signataires. C’est pourquoi, dans un second temps les normes sociales sont endogeneisees au moyen de variables instrumentales. Un nouvel indicateur de normes effectives est obtenu comme un output de l’efficacite du systeme politique et juridique. Il est en effet plus probable que les pays qui jouissent de meilleures institutions soient plus aptes a mettre en place effectivement des normes sociales. L’endogeneisation des normes sociales permet de mettre en evidence l’existence d’une courbe de Kuznets entre les normes et les inegalites de revenu pour 90 pays sur la periode 1990-2001. Les normes sociales sont ainsi mobilisees comme facteur explicatif intermediaire pour interpreter la courbe de Kuznets. This study empirically investigates the impact of core labour standards on income inequality for a range of 90 countries from 1990 to 2001. We focus on the four core labour standards (prohibition of child labour, freedom of association and collective bargaining, prohibition of discrimination, and prohibition of forced labour) defined by ILO and OECD. The number of ILO conventions ratified is added to the four previous variables with the aim to compute a synthetic index of labour standards by means of a Multiple Correspondence Analysis (MCA). This index is then inserted as an independent variable in an econometric model to test for its relationships with the Gini index. No significant correlation is found among the different econometric specifications. One of the reasons pointed out is that there is a difference between norms de jure and de facto. In other words, the exogeneity of the index does not distinguish countries that implement effective social norms from those that just ratify the treaties. We actually assume that the effective implementation of core labour standards depends on the quality of the country’s political and legal systems. The endogeneity bias in the first step models is corrected using instrumental variables in a TSLS model. We found that the relationship between the new endogenous index of core labour standards and income inequality follows a inversed ‘U’ shaped curve. This result let us think of a social Kuznets curve. (Full text in french)
emerging role of cell polarity proteins in breast cancer progression and metastasis

: Breast cancer is a heterogeneous group of diseases that frequently exhibits loss of growth control, and disrupted tissue organization and differentiation. Several recent studies indi-cate that apical–basal polarity provides a tumor-suppressive function, and that disrupting polarity proteins affects many stages of breast cancer progression from initiation through metastasis. In this review we highlight some of the recent advances in our understanding of the molecular mechanisms by which loss of apical–basal polarity deregulates apoptosis, proliferation, and promotes invasion and metastasis in breast cancer.
Mommy tracks and public policy: on self-fulfilling prophecies and gender gaps in promotion

Consider a model with two types of jobs. The profitability of promoting a worker to a fast-track job depends not only on his or her observable talent, but also on incontractible effort. We investigate whether self-fulfilling expectations may lead to higher promotion standards for women. If employers expect women to do more household work than men, thereby exerting less effort in their paid job, then women must be more talented to make promotion profitable. Moreover, specialization in the family will then result in women doing most of the household work. Such self-fulfilling prophecies can be defeated: both affirmative action and family policy can make women spend more effort in the market, which can lead the economy to a non-discriminatory equilibrium. However, we find that it is unlikely that temporary policy can move the economy to a symmetric equilibrium: policy must be made permanent. Anti-discrimination policy need not enhance efficiency, and from a distribution viewpoint this is a policy with both winners and losers.
Protocol for a Cluster Randomised Controlled Trial to Compare the “Taste & See” Programme—A Church-Based Programme to Develop a Healthy Relationship with Food—With a Wait-List Control

(1) Background: Obesity is strongly associated with poor mental-health. Spiritual and religious wellbeing is associated with improved mental well-being and reduced emotional eating. “Taste & See”, a church based programme to help develop a healthy relationship with food has been successfully tested for feasibility in the UK but an adequately powered randomised controlled trial is needed to test efficacy. This paper reports on the protocol for such a trial; (2) Method: A cluster, randomised controlled trial where Christian churches (any denomination) are the unit of randomisation. 150 overweight adults will be recruited from approximately 15 churches (clusters) in the UK, each church (cluster) will recruit approximately 10 participants. Churches will be randomised 2:1 to either begin the “Taste & See” programme immediately or in 10 weeks’ time. Data on eating habits, mental and spiritual health will be collected online before and after the intervention and control period and follow-up will continue until 2 years; (3) Implication of Results: Should the programme prove effective it will provide strong clinical evidence of the role of churches in improving the health and well-being of those struggling with food and weight issues.