Miracle-dz/UniFAR-FTUs huggingface dataset:
Secure Summation: Capacity Region, Groupwise Key, and Feasibility

The secure summation problem is considered, where <inline-formula> <tex-math notation="LaTeX">$K$ </tex-math></inline-formula> users, each holds an input, wish to compute the sum of their inputs at a server securely, i.e., without revealing any information beyond the sum even if the server may collude with any set of up to <inline-formula> <tex-math notation="LaTeX">$T$ </tex-math></inline-formula> users. First, we prove a folklore result for secure summation - to compute 1 bit of the sum securely, each user needs to send at least 1 bit to the server, each user needs to hold a key of at least 1 bit, and all users need to hold collectively some key variables of at least <inline-formula> <tex-math notation="LaTeX">$K-1$ </tex-math></inline-formula> bits. Next, we allow any arbitrary group of users to share an independent key and any arbitrary group of users to collude with the server. For such a general groupwise key and colluding user setting, we show that secure summation is feasible if and only if the hypergraph, where each node is a user and each edge is a group of users sharing the same key, is connected after removing the nodes corresponding to any colluding set of users and their incident edges. Finally, we focus on the symmetric groupwise key setting, where every group of <inline-formula> <tex-math notation="LaTeX">$G$ </tex-math></inline-formula> users share an independent key. We show that for symmetric groupwise keys with group size <inline-formula> <tex-math notation="LaTeX">$G$ </tex-math></inline-formula>, if <inline-formula> <tex-math notation="LaTeX">$G =1$ </tex-math></inline-formula> or <inline-formula> <tex-math notation="LaTeX">$G > K-T$ </tex-math></inline-formula>, the secure summation problem is not feasible; else <inline-formula> <tex-math notation="LaTeX">$1 < G \leq K-T$ </tex-math></inline-formula>, to compute 1 bit of the sum securely, each user needs to send at least 1 bit to the server and the size of each groupwise key is at least <inline-formula> <tex-math notation="LaTeX">$(K-T-1)/\binom {K-T}{G}$ </tex-math></inline-formula> bits.
Monotonicity Regularization: Improved Penalties and Novel Applications to Disentangled Representation Learning and Robust Classification

We study settings where gradient penalties are used alongside risk minimization with the goal of obtaining predictors satisfying different notions of monotonicity. Specifically, we present two sets of contributions. In the first part of the paper, we show that different choices of penalties define the regions of the input space where the property is observed. As such, previous methods result in models that are monotonic only in a small volume of the input space. We thus propose an approach that uses mixtures of training instances and random points to populate the space and enforce the penalty in a much larger region. As a second set of contributions, we introduce regularization strategies that enforce other notions of monotonicity in different settings. In this case, we consider applications, such as image classification and generative modeling, where monotonicity is not a hard constraint but can help improve some aspects of the model. Namely, we show that inducing monotonicity can be beneficial in applications such as: (1) allowing for controllable data generation, (2) defining strategies to detect anomalous data, and (3) generating explanations for predictions. Our proposed approaches do not introduce relevant computational overhead while leading to efficient procedures that provide extra benefits over baseline models.
Asymptotically stable matchings and evolutionary dynamics of preference revelation games in marriage problems

The literature on centralized matching markets often assumes that a true preference of each player is known to herself and ﬁxed, but empirical evidence casts doubt on its plausibility. To circumvent the problem, we consider evolutionary dynamics of preference revelation games in marriage problems. We formulate the asymptotic stability of a matching, indicating the dynamical robustness against suﬃciently small changes in players’ preference reporting strategies, and show that asymptotically stable matchings are stable when they exist. The simulation results of replicator dynamics are presented to demonstrate the asymptotic stability. We contribute a practical insight for market designers that a stable matching may be realized by introducing a learning period in which participants ﬁnd appropriate reporting strategies through trial and error. We also open doors to a novel area of research by demonstrating ways to employ evolutionary game theory in studies on centralized markets.
Perceptual Evaluation on Audio-Visual Dataset of 360 Content

To open up new possibilities to assess the multimodal perceptual quality of omnidirectional media formats, we proposed a novel open source 360 audiovisual (AV) quality dataset. The dataset consists of high-quality 360 video clips in equirectangular (ERP) format and higher-order ambisonic (4th order) along with the subjective scores. Three subjective quality experiments were conducted for audio, video, and AV with the procedures detailed in this paper. Using the data from subjective tests, we demonstrated that this dataset can be used to quantify perceived audio, video, and audiovisual quality. The diversity and discriminability of subjective scores were also analyzed. Finally, we investigated how our dataset correlates with various objective quality metrics of audio and video. Evidence from the results of this study implies that the proposed dataset can benefit future studies on multimodal quality evaluation of 360 content.
Newton and interior-point methods for (constrained) nonconvex-nonconcave minmax optimization with stability guarantees

We address the problem of ﬁnding a local solution to a nonconvex-nonconcave minmax optimization using Newton type methods, including interior-point ones. We modify the Hessian matrix of these methods such that, at each step, the modiﬁed Newton update direction can be seen as the solution to a quadratic program that locally approximates the minmax problem. Moreover, we show that by selecting the modiﬁcation in an appropriate way, the only stable points of the algorithm’s iterations are local minmax points. Using numerical examples, we show that the computation time of our algorithm scales roughly linearly with the number of nonzero elements in the Hessian. For minmax control problems with per-stage costs, this generally leads to computation times that scale linearly with the horizon length. can be appropriately modiﬁed. These results 2) directly motivate the design of novel Newton-type algorithms for minmax optimizationsTheNewton-type algorithms proposed in this paper are motivated by a quadratic local approximation to the optimization criteria to which we add terms to make it have a ﬁnite minmax solution (without necessarily becoming convex-concave). Any additive terms that guarantee this are said to satisfy the Local Quadratic Approximation Condition (LQAC). We show that contrary to minimization, such modiﬁcation does not lead to Newton-type iterations with desired stability: a local minmax can be unstable and an equilibrium point that is not a local minmax can be stable. Our ﬁrst minmax result shows that additional conditions are needed to guarantee that every locally asymptotically stable equilibrium point of a Newton-type iteration is a local minmax. This additional condition is expressed in terms of the inertia of the modiﬁed Hessian matrix, i.e., in terms of the number of positive, negative, and zero eigenvalues.
First BGG operators on homogeneous conformal geometries

We study first BGG operators and their solutions on homogeneous conformal geometries. We focus on conformal Killing tensors, conformal Killing–Yano forms and twistor spinors in particular. We develop an invariant calculus that allows us to find solutions explicitly using only algebraic computations. We also discuss applications to holonomy reductions and conserved quantities of conformal circles. We demonstrate our result on examples of homogeneous conformal geometries coming mostly from general relativity.
Outage Analysis of Energy Efficiency in a Finite-Element-IRS Aided Communication System

In this paper, we study the performance of an energy efficient wireless communication system, assisted by a finite-element-intelligent reflecting surface (IRS). With no instantaneous channel state information (CSI) at the transmitter, we characterize the system performance in terms of the outage probability (OP) of energy efficiency (EE). Depending upon the availability of line-of-sight (LOS) paths, we analyze the system for two different channel models, viz. Rician and Rayleigh. For an arbitrary number of IRS elements $(N)$, we derive the approximate closed-form solutions for the OP of EE, using Laguerre series and moment matching methods. The analytical results are validated using the Monte-Carlo simulations. Moreover, we also quantify the rate of convergence of the derived expressions to the central limit theorem (CLT) approximations using the \textit{Berry-Esseen} inequality. Further, we prove that the OP of EE is a strict pseudo-convex function of the transmit power and hence, has a unique global minimum. To obtain the optimal transmit power, we solve the OP of EE as a constrained optimization problem. To the best of our knowledge, the OP of EE as a performance metric, has never been previously studied in IRS-assisted wireless communication systems.
SAMU-XLSR: Semantically-Aligned Multimodal Utterance-Level Cross-Lingual Speech Representation

We propose the (<inline-formula><tex-math notation="LaTeX">$\tt SAMU\text{-}XLSR$</tex-math></inline-formula>): <underline>S</underline>emantically-<underline>A</underline>ligned <underline>M</underline>ultimodal <underline>U</underline>tterance-level <underline>Cross</underline>-<underline>L</underline>ingual <underline>S</underline>peech <underline>R</underline>epresentation learning framework. Unlike previous works on speech representation learning, which learns multilingual contextual speech embedding at the resolution of an acoustic frame (10–20 ms), this work focuses on learning multimodal (speech-text) multilingual speech embedding at the resolution of a sentence (5–10 s) such that the embedding vector space is semantically aligned across different languages. We combine state-of-the-art multilingual acoustic frame-level speech representation learning model <inline-formula><tex-math notation="LaTeX">$\tt XLSR$</tex-math></inline-formula> with the Language Agnostic BERT Sentence Embedding (<inline-formula><tex-math notation="LaTeX">$\tt LaBSE$</tex-math></inline-formula>) model to create an utterance-level multimodal multilingual speech encoder <inline-formula><tex-math notation="LaTeX">$\tt SAMU\text{-}XLSR$</tex-math></inline-formula>. Although we train <inline-formula><tex-math notation="LaTeX">$\tt SAMU\text{-}XLSR$</tex-math></inline-formula> with only multilingual transcribed speech data, cross-lingual speech-text and speech-speech associations emerge in its learned representation space. To substantiate our claims, we use <inline-formula><tex-math notation="LaTeX">$\tt SAMU\text{-}XLSR$</tex-math></inline-formula> speech encoder in combination with a pre-trained <inline-formula><tex-math notation="LaTeX">$\tt LaBSE$</tex-math></inline-formula> text sentence encoder for cross-lingual speech-to-text translation retrieval, and <inline-formula><tex-math notation="LaTeX">$\tt SAMU\text{-}XLSR$</tex-math></inline-formula> alone for cross-lingual speech-to-speech translation retrieval. We highlight these applications by performing several cross-lingual text and speech translation retrieval tasks across several datasets.
Moduli spaces of $\mathbb{Z}/k\mathbb{Z}$-constellations over $\mathbb{A}^2$

Let $\rho:\mathbb{Z}/k \mathbb{Z}\rightarrow \text{SL}(2,\mathbb{C})$ be a representation of a finite abelian group and let $\Theta^{\text{gen}}\subset \text{Hom}_\mathbb{Z}(R(\mathbb{Z}/k\mathbb{Z}),\mathbb{Q})$ be the space of generic stability conditions on the set of $G$-constellations. We provide a combinatorial description of all the chambers $C\subset\Theta^{\text{gen}}$ and prove that there are $k! $ of them. Moreover, we introduce the notion of simple chamber and we show that, in order to know all toric $G$-constellations, it is enough to build all simple chambers. We also prove that there are $k\cdot 2^{k-2} $ simple chambers. Finally, we provide an explicit formula for the tautological bundles $\mathscr{R}_C$ over the moduli spaces $\mathscr{M} _C$ for all chambers $C\subset \Theta^{\text{gen}}$ which only depends upon the chamber stair which is a combinatorial object attached to the chamber $C$.
Method to measure the quality of a neuron model compared to recorded data

In this thesis, a method for evaluating the accuracy of mathematical neuron models is developed, with the objective to both improve the quality and the speed of parameter optimization. To evaluate the method, we used a conductance based model of the cuneate nucleus. The model behavior was evaluated against neurons recorded in vivo. A big challenge when modeling neurons is the timing of the action potentials, since the initiation is stochastic. Therefore, the model artificially inserts the spikes at the recorded spike times. The accuracy of the model is evaluated as its capacity to capture the time evolution of the membrane potential both following and preceding the spikes. The evaluation method uses the L2-norm when comparing a few important time windows of the recording and the model. The method was used to optimize the parameters of the model. Sensitivity analysis is used to learn which model parameters affect the model accuracy the most. The results from the optimization showed that the developed method well describes the quality of the neuron model for different parameters. This tool will make it easier to build models that capture the responsive properties of the membrane potential in neuronal in vivo recordings. (Less)
Age-dependent genetic architecture across ontogeny of body size in sticklebacks

Heritable variation in traits under natural selection is a prerequisite for evolutionary response. While it is recognized that trait heritability may vary spatially and temporally depending on which environmental conditions traits are expressed under, less is known about the possibility that genetic variance contributing to the expected selection response in a given trait may vary at different stages of ontogeny. Specifically, whether different loci underlie the expression of a trait throughout development and thus providing an additional source of variation for selection to act on in the wild, is unclear. Here we show that body size, an important life-history trait, is heritable throughout ontogeny in the nine-spined stickleback (Pungitius pungitius). Nevertheless, both analyses of quantitative trait loci and genetic correlations across ages show that different chromosomes/loci contribute to this heritability in different ontogenic time-points. This suggests that body size can respond to selection at different stages of ontogeny but that this response is determined by different loci at different points of development. Hence, our study provides important results regarding our understanding of the genetics of ontogeny and opens an interesting avenue of research for studying age-specific genetic architecture as a source of non-parallel evolution.
Property Rights to Land and Agricultural Organization: An Argentina–United States Comparison

The contributions of Harold Demsetz offer key insights on how property rights and transaction costs shape economic organization. These guide our comparison of agricultural organization in the early 20th century in two comparable regions, the Argentine Pampas and the US Midwest. In the United States, land was distributed in small parcels and actively traded. In the Pampas, land was distributed in large plots, and trade was limited because land was a social and political asset, as well as a commercial one. We analyze why the absence of trade led to persistently larger farms, specialization in ranching, and peculiar tenancy contracts in Argentina relative to the United States. Our empirical analysis, based on county-level data for both regions, shows that geoclimatic factors cannot explain the observed differences in agricultural organization. We discuss implications for long-term economic development in Argentina.
Contemporary sea-level changes from global to local scales: a review

Sea-level variations spread over a very broad spectrum of spatial and temporal scales as a result of complex processes occurring in the Earth System in response to natural variability of the climate system, as well as to external forcing due to natural phenomena and anthropogenic factors. Here, we address contemporary sea-level changes, focusing on the satellite altimetry era (since the early 1990s), for which various observing systems from space and in situ allow precise monitoring of sea-level variations from global to local scales, as well as improved understanding of the components responsible for the observed variations. This overview presents the most recent results on observed global and regional sea-level changes and on associated causes, focusing on the interannual to decadal time scale. Recent progress in measuring sea level at the coast are presented. Finally, a summary of the most recent sea-level projections from the Intergovernmental Panel on Climate Change is also provided.
Using Metabolic Theory to Describe Temperature and Thermal Acclimation Effects on Parasitic Infection

Predicting temperature effects on species interactions can be challenging, especially for parasitism, where it is difficult to experimentally separate host and parasite thermal performance curves. Prior authors proposed a possible solution based on the metabolic theory of ecology (MTE), using MTE-based equations to describe the thermal mismatch between host and parasite performance curves and account for thermal acclimation responses. Here, we use published infection data, supplemented with experiments measuring metabolic responses to temperature in each species, to show that this modeling framework can successfully describe thermal acclimation effects on two different stages of infection in a tadpole-trematode system. All thermal acclimation effects on host performance manifested as changes in one key model parameter (activation energy), with measurements of host respiration generating similar MTE parameter estimates and acclimation effects compared with measurements of the host’s ability to clear encysted parasites. This result suggests that metabolic parameter estimates for whole-body metabolism can sometimes be used to estimate temperature effects on host and parasite performance curves. However, we found different thermal patterns for measurements of host prevention of initial parasite encystment emphasizing potential challenges when applying MTE-based models to complex parasite-host systems with multiple distinct stages of infection.
Phagocytosis of exogenous bacteria by gill epithelial cells in the deep-sea symbiotic mussel Bathymodiolus japonicus

Animals that live in nutrient-poor environments, such as the deep sea, often establish intracellular symbiosis with beneficial bacteria that provide the host with nutrients that are usually inaccessible to them. The deep-sea mussel Bathymodiolus japonicus relies on nutrients from the methane-oxidizing bacteria harboured in epithelial gill cells called bacteriocytes. These symbionts are specific to the host and transmitted horizontally, being acquired from the environment by each generation. Morphological studies in mussels have reported that the host gill cells acquire the symbionts via phagocytosis, a process that facilitates the engulfment and digestion of exogenous microorganisms. However, gill cell phagocytosis has not been well studied, and whether mussels discriminate between the symbionts and other bacteria in the phagocytic process remains unknown. Herein, we aimed to investigate the phagocytic ability of gill cells involved in the acquisition of symbionts by exposing the mussel to several types of bacteria. The gill cells engulfed exogenous bacteria from the environment indiscriminately. These bacteria were preferentially eliminated through intracellular digestion using enzymes; however, most symbionts were retained in the bacteriocytes without digestion. Our findings suggest that regulation of the phagocytic process after engulfment is a key mechanism for the selection of symbionts for establishing intracellular symbiosis.
Unexpected morphological diversity in ancient dogs compared to modern relatives

Dogs are among the most variable species today, but little is known about the morphological variability in the early phases of their history. The Neolithic transition to farming may have resulted in an early morphological diversification as a result of changes in the anthropic environment or intentional selection on specific morphologies. Here, we describe the variability and modularity in mandible form by comparing 525 dog mandibles from European archaeological sites ranging from 8100 to 3000 cal. BC to a reference sample of modern dogs, wolves, and dingoes. We use three-dimensional geometric morphometrics to quantify the form of complete and fragmented mandibles. We demonstrate that an important morphological variability already existed before the Bronze Age in Europe, yet the largest, smallest, most brachycephalic or dolichocephalic extant dogs have no equivalent in the archaeological sample, resulting in a lower variation compared to modern relatives. The covariation between the anterior and posterior parts of the mandible is lower in archaeological dogs, suggesting a low degree of intentional human selection in early periods. The mandible of modern and ancient dogs differs in functionally important areas, possibly reflecting differences in diet, competition, or the implication of ancient dogs in hunting or defence.
Local mechanical stimuli correlate with tissue growth in axolotl salamander joint morphogenesis

Movement-induced forces are critical to correct joint formation, but it is unclear how cells sense and respond to these mechanical cues. To study the role of mechanical stimuli in the shaping of the joint, we combined experiments on regenerating axolotl (Ambystoma mexicanum) forelimbs with a poroelastic model of bone rudiment growth. Animals either regrew forelimbs normally (control) or were injected with a transient receptor potential vanilloid 4 (TRPV4) agonist during joint morphogenesis. We quantified growth and shape in regrown humeri from whole-mount light sheet fluorescence images of the regenerated limbs. Results revealed significant differences in morphology and cell proliferation between groups, indicating that TRPV4 desensitization has an effect on joint shape. To link TRPV4 desensitization with impaired mechanosensitivity, we developed a finite element model of a regenerating humerus. Local tissue growth was the sum of a biological contribution proportional to chondrocyte density, which was constant, and a mechanical contribution proportional to fluid pressure. Computational predictions of growth agreed with experimental outcomes of joint shape, suggesting that interstitial pressure driven from cyclic mechanical stimuli promotes local tissue growth. Predictive computational models informed by experimental findings allow us to explore potential physical mechanisms involved in tissue growth to advance our understanding of the mechanobiology of joint morphogenesis.