Miracle-dz/UniFAR-FTUs huggingface dataset:
What's wrong with the growth of simple closed geodesics on nonorientable hyperbolic surfaces

A celebrated result of Mirzakhani states that, if $(S,m)$ is a finite area \emph{orientable} hyperbolic surface, then the number of simple closed geodesics of length less than $L$ on $(S,m)$ is asymptotically equivalent to a positive constant times $L^{\dim\mathcal{ML}(S)}$, where $\mathcal{ML}(S)$ denotes the space of measured laminations on $S$. We observed on some explicit examples that this result does not hold for \emph{nonorientable} hyperbolic surfaces. The aim of this article is to explain this surprising phenomenon. Let $(S,m)$ be a finite area \emph{nonorientable} hyperbolic surface. We show that the set of measured laminations with a closed one--sided leaf has a peculiar structure. As a consequence, the action of the mapping class group on the projective space of measured laminations is not minimal. We determine a partial classification of its orbit closures, and we deduce that the number of simple closed geodesics of length less than $L$ on $(S,m)$ is negligible compared to $L^{\dim\mathcal{ML}(S)}$. We extend this result to general multicurves. Then we focus on the geometry of the moduli space. We prove that its Teichm\"uller volume is infinite, and that the Teichm\"uller flow is not ergodic. We also consider a volume form introduced by Norbury. We show that it is the right generalization of the Weil--Petersson volume form. The volume of the moduli space with respect to this volume form is again infinite (as shown by Norbury), but the subset of hyperbolic surfaces whose one--sided geodesics have length at least $\varepsilon>0$ has finite volume. These results suggest that the moduli space of a nonorientable surface looks like an infinite volume geometrically finite orbifold. We discuss this analogy and formulate some conjectures.
On Fano Schemes of Toric Varieties

Let $X_\mathcal{A}$ be the projective toric variety corresponding to a finite set of lattice points $\mathcal{A}$. We show that irreducible components of the Fano scheme $\mathbf{F}_k(X_\mathcal{A})$ parametrizing $k$-dimensional linear subspaces of $X_\mathcal{A}$ are in bijection to so-called maximal Cayley structures for $\mathcal{A}$. We explicitly describe these irreducible components and their intersection behaviour, characterize when $\mathbf{F}_k(X_\mathcal{A})$ is connected, and prove that if $X_\mathcal{A}$ is smooth in dimension $k$, then every component of $\mathbf{F}_k(X_\mathcal{A})$ is smooth in its reduced structure. Furthermore, in the special case $k=\dim X_\mathcal{A}-1$, we describe the non-reduced structure of $\mathbf{F}_k(X_\mathcal{A})$. Our main result is closely related to concurrent work done independently by Furukawa and Ito.
Effects of rapidly diverging flow, heat addition, and momentum addition in the solar wind and stellar winds

The roles of rapid flow tube divergence and heat and momentum addition in one-fluid models of the solar wind and stellar winds and the role of heat addition in two-fluid models of the solar wind ae explored. It is found that under certain circumstances heat addition, momentum addition, or the rapid divergence of a flow tube can produce more than one critical point in the solution topologies of the solar and stellar wind equations. For the solar wind, additional critical points associated with rapid flow tube divergence (e.g., in coronal holes) and/or with momentum addition can lead to high expansion speeds near the coronal base, and these high speeds, in conjuction with a rapid flow tube divergence, may in certain cases produce an increased conductive energy supply to the solar wind. If such an increased conductive energy supply is produced, the need for energy addition above the coronal base is correspondingly reduced. In addition, the high flow speeds at low altitudes make it possible for any required energy addition to occur relatively near the coronal base, so that the need for extended heating of the solar wind may be substantially less than has been suggested in the past. For radiation-drivenmore » stellar winds the additional critical points associated with rapid flow tube divergence can lead to supersonic flow much deeper in the stellar atmosphere than is predicted by radial, spherically symmetric flow models, and this might resolve the apparent conflict between radiation-driven wind models and certain observations of Of stars. In two-fluid solar wind models including proton heat addition it is shown that the radial electron temperature profile has a sufficiently important dynamical influence that the accurate treatment of electron energy transport is a primary prerequisite to obtaining quantitatively significant results. (AIP)« less
A Stronger Convergence Result on the Proximal Incremental Aggregated Gradient Method

We study the convergence rate of the proximal incremental aggregated gradient (PIAG) method for minimizing the sum of a large number of smooth component functions (where the sum is strongly convex) and a non-smooth convex function. At each iteration, the PIAG method moves along an aggregated gradient formed by incrementally updating gradients of component functions at least once in the last $K$ iterations and takes a proximal step with respect to the non-smooth function. We show that the PIAG algorithm attains an iteration complexity that grows linear in the condition number of the problem and the delay parameter $K$. This improves upon the previously best known global linear convergence rate of the PIAG algorithm in the literature which has a quadratic dependence on $K$.
Close-Packed Quad-Element Triple-Band-Notched UWB MIMO Antenna With Upgrading Capability

A close-packed 4-port multiple-input multiple-output (MIMO) antenna with three notched bands (NBs) is designed for ultra-wideband (UWB) applications. The presented antenna contains four monopole antenna elements (AEs) with rectangular radiators, each fed by an L-shaped microstrip line. The compact size of <inline-formula> <tex-math notation="LaTeX">$35.9\times 35.9\times0.8$ </tex-math></inline-formula> mm is attained by cropping the lower axis of the antenna and optimization. The isolation greater than 19 dB is accomplished by the orthogonal direction of AEs and cross-shaped decoupling structure (CSDS). The designed antenna can realize wireless local area network (WLAN) and X-band NBs by etching two C-shaped slits from each radiator and Worldwide Interoperability for Microwave Access (WiMAX) NB by introducing an L-shaped slit in the ground. By placing these NBs in appropriate positions, their efficiencies are decreased for their better rejection. The value of <inline-formula> <tex-math notation="LaTeX">$\vert \text{S}_{\mathrm {ii}}\vert < -10$ </tex-math></inline-formula> dB is from 3.2 to 10.8 GHz (except for three NBs). Also, the 4-port MIMO antenna is upgraded to a 16-port MIMO antenna by arranging the four identical 4-port MIMO antennas side by side with a small gap of 8 mm. The upgraded antenna gives bandwidths from 3.38 to 10.56 GHz with three NBs, isolation >20.9 dB, and size <inline-formula> <tex-math notation="LaTeX">$79.8\times79.8$ </tex-math></inline-formula> mm2, which is appropriate for future wireless communications.
Continuum Space Limit of the Genealogies of Interacting Fleming-Viot Processes on $\Z$

We study the evolution of genealogies of a population of individuals, whose type frequencies result in an interacting Fleming-Viot process on $\Z$. We construct and analyze the genealogical structure of the population in this genealogy-valued Fleming-Viot process as a marked metric measure space, with each individual carrying its spatial location as a mark. We then show that its time evolution converges to that of the genealogy of a continuum-sites stepping stone model on $\R$, if space and time are scaled diffusively. We construct the genealogies of the continuum-sites stepping stone model as functionals of the Brownian web, and furthermore, we show that its evolution solves a martingale problem. The generator for the continuum-sites stepping stone model has a singular feature: at each time, the resampling of genealogies only affects a set of individuals of measure $0$. Along the way, we prove some negative correlation inequalities for coalescing Brownian motions, as well as extend the theory of marked metric measure spaces (developed recently by Depperschmidt, Greven and Pfaffelhuber [DGP12]) from the case of probability measures to measures that are finite on bounded sets.
The Asymptotic Existence of Resolvable Group Divisible Designs

A group divisible design (GDD) is a triple (X,G,B) which satisfies the following properties: (1) G is a partition of X into subsets called groups; (2) B is a collection of subsets of X, called blocks, such that a group and a block contain at most one element in common; and (3) every pair of elements from distinct groups occurs in a constant number λ blocks. This parameter λ is usually called the index. A k‐GDD of type gu is a GDD with block size k, index λ=1 , and u groups of size g. A GDD is resolvable if the blocks can be partitioned into classes such that each point occurs in precisely one block of each class. We denote such a design as an RGDD. For fixed integers g≥1 and k≥2 , we show that the necessary conditions for the existence of a k‐RGDD of type gu are sufficient for all u≥u0(g,k) . As a corollary of this result and the existence of large resolvable graph decompositions, we establish the asymptotic existence of resolvable graph GDDs, G‐RGDDs, whenever the necessary conditions for the existence of (v,G,1) ‐RGDs are met. We also show that, with a few easy modifications, the techniques extend to general index. © 2012 Wiley Periodicals, Inc. J. Combin. Designs 21: 112–126, 2013
Towards Theory and Applications of Generalized Categories to Areas of Type Theory and Categorical Logic

Motivated by potential applications to theoretical computer science, in particular those areas where the Curry-Howard correspondence plays an important role, as well as by the ongoing search in pure mathematics for feasible approaches to higher category theory, we undertake a detailed study of a new mathematical abstraction, the generalized category. It is a partially defined monoid equipped with endomorphism maps defining sources and targets on arbitrary elements, possibly allowing a proximal behavior with respect to composition. We first present a formal introduction to the theory of generalized categories. We describe functors, equivalences, natural transformations, adjoints, and limits in the generalized setting. Next we indicate how the theory of monads extends to generalized categories. Next, we present a variant of the calculus of deductive systems developed by Lambek, and give a generalization of the Curry-Howard-Lambek theorem giving an equivalence between the category of typed lambda-calculi and the category of cartesian closed categories and exponential-preserving morphisms that leverages the theory of generalized categories. Next, we develop elementary topos theory in the generalized setting of ideal toposes, utilizing the formalism developed for the Curry-Howard-Lambek theorem. In particular, we prove that ideal toposes possess the same Heyting algebra structure and squares of adjoints that ordinary toposes do. Finally, we develop generalized sheaves, and show that such categories form ideal toposes. We extend Lawvere and Tierney's theorem relating $j$-sheaves and sheaves in the sense of Grothendieck to the generalized setting.
Social Service Workers’ Use of Social Media to Obtain Client Information: Current Practices and Perspectives on a Potential Informatics Platform

Abstract To gain insight into current use of social-media platforms in human services delivery, we systematically surveyed 172 social-service workers from six agencies in a Midwest US city to gather data about social-media usage among social-service providers, potential challenges and benefits of using social media, and whether a social-media-based informatics platform could be valuable. Quantitative analyses showed that approximately half of participants have used social media to collect client-related information; nearly one-quarter indicated “often” or “nearly daily” use. Adjusting for the effects of worker characteristics, social-media use was associated with the type of agency involved and with increased tenure in social services. Adjusted results also showed that participants’ comfort with using the potential application was greater in those agencies substantially involved with investigative/legal work. However, trust in the information collected by the potential application was a stronger, independent predictor of comfort using the tool. Qualitative analyses identified numerous challenges and ethical concerns, and positive and negative aspects of a social-media-based informatics platform. If the platform is to be created, work must be done carefully, fully considering ethical issues rightly raised by social service workers, existing agency policies, and professional standards. Future research should investigate ways to negotiate these complex challenges.
Recent Trends in Transport of Surface Carbonaceous Aerosols to the Upper‐Troposphere‐Lower‐Stratosphere Linked to Expansion of the Asian Summer Monsoon Anticyclone

Using Modern‐Era Retrospective analysis for Research and Applications Version‐2 (MERRA‐2) re‐analyses, we have examined recent trends (2000–2019) in transport of surface carbonaceous aerosols (CAs), that is, organic carbon and black carbon, to the upper troposphere and lower stratosphere (UTLS) during the Asian summer monsoon (ASM). We find a significant increased concentration of UTLS CA, linked to a linear trend in an expansion of the Asian Summer Monsoon Anticyclone (ASMA). Over core monsoon latitudes (25°–35°N), the trends in UTLS CA are enabled by increased upward transport from surface sources via an intensified monsoon meridional circulation, with increased latent heating over the southern Tibetan Plateau and foothill regions, enhanced by feedback processes associated with radiative heating by UTLS CA. In the extra‐tropics, increased UTLS CA stems primarily from an extended source of increased wildfire emissions over eastern Siberia and northern Asia, coincident with a large‐scale anomalous anticyclone with enhanced surface warming and drying near (80°–120°E, 55°–70°N). Here, CAs are transported upward from the surface to the ULS, likely by increased pyro‐convection associated with enhanced wildfires, and enter the tropical UTLS via increased equatorward transport on the eastern flanks of anomalous upper‐level anticyclones, coupled to the expanded ASMA. Overall, the increasing UTLS CA trends associated with expansion of the ASMA are consistent with a hydrostatic expansion of a warming troposphere, reflected in a rise in the tropical tropopause and consequential dynamical adjustments of the ASM subtropical jetstream, modulating the climate of the greater ASM region.
Reciprocal Effects of Career Adaptability and Occupational Self-Efficacy: A Three-Wave Longitudinal Study With Varying Time Lags

Researchers widely agree upon the pivotal role of career self-management in vocational development. Yet, little is known about how core self-management constructs denoting agentic capacity affect each other reciprocally over time. We address the shortage of existing longitudinal change investigations by proposing and testing a reciprocal model in which career adaptability and occupational self-efficacy as core career self-management constructs are reciprocally interrelated. Cross-lagged panel analyses of three-wave data from a large and heterogeneous sample of employees indicate support for the presence of substantial reciprocal effects of career adaptability and occupational self-efficacy across time lags of three, six, and nine months. From a series of exploratory multigroup analyses, this pattern of results emerges as robust across a range of sociodemographic variables, including gender, age, education, leadership position, and organizational tenure. Moreover, the results remained stable after considering further controls (e.g., future temporal focus, grade point average). Our findings broaden the scope of dynamic vocational research by demonstrating the utility of a change-oriented approach in elucidating the emergence of individuals’ career self-management. We discuss practical implications concerning career intervention strategies, study limitations, and prospects for future research.
Search and Rescue Ships as Exceptional Spaces in the Mediterranean: Navigating Emergencies, Threats and Governmental Actions

ABSTRACT Since 2014, there has been an increase in non-governmental Search and Rescue activities (SAR) on the Central Mediterranean Route (CMR). Scholarly attention has focused on refugees’ and migrants’ lived experiences on the route. When engaging with non-governmental SAR ships, recent migration scholarship mostly concentrated on their function to rescue and to be a symbol for political activism. What is currently missing is a thorough exploration of rescue ships exceeding their function to rescue through the lens of humanitarian action. Scholarship has to expand on mechanisms and dynamics of political interference and the rejection thereof. Hence, I explore how SAR vessels can be conceptualized as exceptional spaces and how this affects NGO activists on those ships. This article is based on semi-structured interviews with activists that worked with SAR NGOs and on participatory observation on a SAR vessel. The article offers specific insights into the dynamics and mechanisms of rescue ships as exceptional spaces on the CMR and engages with wider debates about exceptional spaces.
Baire class 1 selectors for upper semicontinuous set-valued maps

Let T be a metric space and X a Banach space. Let F: T → X be a set-valued map assuming arbitrary values and satisfying the upper semicontinuity condition: {t ∈ T: F(t) ∩ C ¬= O} is closed for each weakly closed set C in X. Then there is a sequence of norm-continuous functions converging pointwise (in the norm) to a selection for F. We prove a statement of similar precision and generality when X is a metric space
Efficient tensor tomography in fan-beam coordinates. II: Attenuated transforms

This article extends the author's past work [Inv. Probl. Imaging, 10:2 (2016), 433--459] to attenuated X-ray transforms, where the attenuation is complex-valued and only depends on position. We give a positive and constructive answer to the attenuated tensor tomography problem on the Euclidean unit disc in fan-beam coordinates. For a tensor of arbitrary order, we propose an equivalent tensor of the same order which can be uniquely and stably reconstructed from its attenuated transform, as well as an explicit and efficient procedure to do so.
Terminal Uridylyltransferases TUT4/7 Regulate microRNA and mRNA Homeostasis

The terminal nucleotidyltransferases TUT4 and TUT7 (TUT4/7) regulate miRNA and mRNA stability by 3′ end uridylation. In humans, TUT4/7 polyuridylates both mRNA and pre-miRNA, leading to degradation by the U-specific exonuclease DIS3L2. We investigate the role of uridylation-dependent decay in maintaining the transcriptome by transcriptionally profiling TUT4/7 deleted cells. We found that while the disruption of TUT4/7 expression increases the abundance of a variety of miRNAs, the let-7 family of miRNAs is the most impacted. Eight let-7 family miRNAs were increased in abundance in TUT4/7 deleted cells, and many let-7 mRNA targets are decreased in abundance. The mRNAs with increased abundance in the deletion strain are potential direct targets of TUT4/7, with transcripts coding for proteins involved in cellular stress response, rRNA processing, ribonucleoprotein complex biogenesis, cell–cell signaling, and regulation of metabolic processes most affected in the TUT4/7 knockout cells. We found that TUT4/7 indirectly control oncogenic signaling via the miRNA let-7a, which regulates AKT phosphorylation status. Finally, we find that, similar to fission yeast, the disruption of uridylation-dependent decay leads to major rearrangements of the transcriptome and reduces cell proliferation and adhesion.
African Swine Fever Modified Live Vaccine Candidates: Transitioning from Discovery to Product Development through Harmonized Standards and Guidelines

The recent centennial anniversary of R.E. Montgomery’s seminal published description of “a form of swine fever” disease transmitted from wild African pigs to European domestic pigs is a call to action to accelerate African Swine Fever (ASF) vaccine research and development. ASF modified live virus (MLV) first-generation gene deleted vaccine candidates currently offer the most promise to meet international and national guidelines and regulatory requirements for veterinary product licensure and market authorization. A major, rate-limiting impediment to the acceleration of current as well as future vaccine candidates into regulatory development is the absence of internationally harmonized standards for assessing vaccine purity, potency, safety, and efficacy. This review summarizes the asymmetrical landscape of peer-reviewed published literature on ASF MLV vaccine approaches and lead candidates, primarily studied to date in the research laboratory in proof-of-concept or early feasibility clinical safety and efficacy studies. Initial recommendations are offered toward eventual consensus of international harmonized guidelines and standards for ASF MLV vaccine purity, potency, safety, and efficacy. To help ensure the successful regulatory development and approval of ASF MLV first generation vaccines by national regulatory associated government agencies, the World Organisation for Animal Health (WOAH) establishment and publication of harmonized international guidelines is paramount.
Effect of the Binder during Ultra-Precision Polishing of Tungsten Carbide Using a Semirigid Bonnet Tool

Tungsten carbide (WC) has the characteristics of high hardness, high strength, corrosion resistance, wear resistance and excellent fracture toughness. Accordingly, it has been commonly used as the material for cutting tools and molds in glass-forming techniques. To obtain ultra-smooth surfaces, fine polishing of WC is indispensable. However, the efficiency of WC polishing is low using the existing polishing methods, and the mechanism behind the polishing process requires further investigation. Specifically, the effect of the binder in WC polishing is not clear since there are different kinds of WC with various weight percentages of the binder. In this paper, we present the findings of a study on the polishing performance of two kinds of WC material, with and without the binder, using a semi-rigid (SR) bonnet polishing tool. A series of experiments were performed on a 6-DOF robotic polishing instrument to investigate the material-removal characteristics, surface integrity and sub-surface damage after polishing. The results demonstrate that the SR bonnet polishing tool successfully reduced the surface roughness of WC with and without the binder to the nanometric level, though the lowest surface roughness was obtained on binder-less WC. No obvious sub-surface damage was observed under SEM inspection, while the processing efficiency was greatly improved owing to the high material removal rate of the tool. Based on our analysis of key polishing parameters and corresponding surface integrities, the effect of the binder on the polishing performance is explained, which offers excellent guidance for WC polishing.