Nonlinear sufficient dimension reduction for distribution-on-distribution regression.

We introduce a new approach to nonlinear sufficient dimension reduction in cases where both the predictor and the response are distributional data, modeled as members of a metric space. Our key step is to build universal kernels (cc-universal) on the metric spaces, which results in reproducing kernel Hilbert spaces for the predictor and response that are rich enough to characterize the conditional independence that determines sufficient dimension reduction. For univariate distributions, we construct the universal kernel using the Wasserstein distance, while for multivariate distributions, we resort to the sliced Wasserstein distance. The sliced Wasserstein distance ensures that the metric space possesses similar topological properties to the Wasserstein space, while also offering significant computation benefits. Numerical results based on synthetic data show that our method outperforms possible competing methods. The method is also applied to several data sets, including fertility and mortality data and Calgary temperature data.

Autoregressive optimal transport models.

Series of univariate distributions indexed by equally spaced time points are ubiquitous in applications and their analysis constitutes one of the challenges of the emerging field of distributional data analysis. To quantify such distributional time series, we propose a class of intrinsic autoregressive models that operate in the space of optimal transport maps. The autoregressive transport models that we introduce here are based on regressing optimal transport maps on each other, where predictors can be transport maps from an overall barycenter to a current distribution or transport maps between past consecutive distributions of the distributional time series. Autoregressive transport models and their associated distributional regression models specify the link between predictor and response transport maps by moving along geodesics in Wasserstein space. These models emerge as natural extensions of the classical autoregressive models in Euclidean space. Unique stationary solutions of autoregressive transport models are shown to exist under a geometric moment contraction condition of Wu & Shao [(2004) Limit theorems for iterated random functions. Journal of Applied Probability 41, 425-436)], using properties of iterated random functions. We also discuss an extension to a varying coefficient model for first-order autoregressive transport models. In addition to simulations, the proposed models are illustrated with distributional time series of house prices across U.S. counties and annual summer temperature distributions.

Two new Ptychoptera Meigen, 1803 (Diptera, Ptychopteridae) from the Western Palaearctic.

Ptychopteraxanthopleura Dvorák, Obona & Manko, sp. nov. from Azerbaijan and Georgia, and Ptychopterastaryi Dvorák, Obona & Manko, sp. nov. from Bulgaria are described. P.xanthopleurasp. nov. differs from the other member of the lacustris group mainly by having almost completely yellow pleurae, and by the shape of the epandrium and gonocoxites. The diagnostics of P.staryisp. nov. and P.incognita Török, Kolcsár & Keresztes, 2015 based on male genitalia are provided.

EphemBrazil: a curated online database and dashboard to explore the distribution of mayflies (Insecta: Ephemeroptera) from Brazil

ABSTRACT Despite the growing number of studies on mayflies (Ephemeroptera), especially in terms of description of new species and distributional records, the knowledge generated remains scattered across specialized literature. This dispersion poses a challenge for non-specialists, such as ecologists, hindering their ability to promote studies and conservation actions. In order to fill this gap, we are launching EphemBrazil: an online database focusing on the distribution of mayflies in Brazil. The main objectives of this platform are to compile a dataset of distributional information for the valid species of Ephemeroptera in Brazil, provide open access to this dataset through an interactive and easily updated website, and offer dynamic distributional maps for species, genera, and families of Brazilian mayflies. EphemBrazil aims to facilitate the retrieval and access of distributional and basic taxonomic information for the order.

Glucodensities: A new representation of glucose profiles using distributional data analysis.

Biosensor data have the potential to improve disease control and detection. However, the analysis of these data under free-living conditions is not feasible with current statistical techniques. To address this challenge, we introduce a new functional representation of biosensor data, termed the glucodensity, together with a data analysis framework based on distances between them. The new data analysis procedure is illustrated through an application in diabetes with continuous-time glucose monitoring (CGM) data. In this domain, we show marked improvement with respect to state-of-the-art analysis methods. In particular, our findings demonstrate that (i) the glucodensity possesses an extraordinary clinical sensitivity to capture the typical biomarkers used in the standard clinical practice in diabetes; (ii) previous biomarkers cannot accurately predict glucodensity, so that the latter is a richer source of information and; (iii) the glucodensity is a natural generalization of the time in range metric, this being the gold standard in the handling of CGM data. Furthermore, the new method overcomes many of the drawbacks of time in range metrics and provides more in-depth insight into assessing glucose metabolism.

A contribution to the knowledge of the genus Lacvietina Herman (Coleoptera: Staphylinidae: Tachyporinae) from China.

The tachyporine genus Lacvietina Herman is represented in China by two species: L. punctatissima (Hayashi) from Taiwan and L. lii (Li, Tang Zhu) from Guizhou. Here we described a third species, L. nabanhensis Chang, Li Yin, sp. nov., from Yunnan. Moreover, new collecting data and a redescription of L. lii are provided.

Assessing drug effect from distributional data: A population approach with application to Duchenne Muscular Dystrophy treatment.

BACKGROUND AND OBJECTIVE: In Duchenne Muscular Dystrophy (DMD) treatment, muscle fiber size can be considered as an indicator of muscle health and function. In particular, the statistical distribution of fibers cross-sectional areas (CSAs) has been used as quantitative efficacy endpoint. For each patient, assessment of treatment effect relies on the comparison of pre- and post-treatment biopsies. Since biopsies provide "distributional data", i.e. empirical distributions of fibers CSA, the comparison must be carried out between the empirical pre- and post-treatment distributions. METHODS: Here, distributional fiber CSA data are analyzed by means of a hierarchical statistical model based on the population approach, considering both the single patient and the population level. RESULTS: The proposed method was used to assess the histological clinical effects of Givinostat, a compound under study for DMD treatment. At the single patient level, a two-component Gaussian mixture adequately represents pre- and post-treatment distributions of log-transformed CSAs; drug effect is described via a dose-dependent multiplicative increase of muscle fiber size. The single patient model was also validated via muscle composition data. At the patient population level, typical model parameters and inter-patient variabilities were obtained. CONCLUSIONS: The proposed methodological approach completely characterizes fiber CSA distributions and quantifies drug effect on muscle fiber size, both at the single patient and at the patient population level. This approach might be applied also in other contexts, where outcomes measured in terms of distributional data are to be assessed.

Invasion of the Indo-Pacific blenny Omobranchus punctatus (Perciformes: Blenniidae) on the Atlantic Coast of Central and South America

We examined 308 specimens of the Indo-Pacific blenniid Omobranchus punctatus deposited in four museum collections, and analyzed data on their collection locations to assess its invasion on the Atlantic coast of Central and South America. This species occurs in shoreline estuarine and marine habitats in the Indo-West Pacific. Previous sampling and recent records in the Tropical West Atlantic from 1930 to 2004 produced 20 records for: Panamá, Colombia, Venezuela, Trinidad and Brazil. In this work, we provide data on 17 new records for the Gulfs of Venezuela and Paria in Venezuela, as well as four records for Maranhão and Pará states in NE Brazil. The temporal pattern of collections (1930 - 2009) and the proximity of most localities to ports and zones of ship traffic indicate that O. punctatus was initially introduced to the Atlantic by ships travelling from India to Trinidad. Within Brazil the introduction is linked to shipping connected to petroleum platforms. In Maranhão and Pará the introduction may have occurred as a result of fish sheltering in fouling on hulls of ships moving between ports around the mouth of the Amazon River. Alternatively, the spread of this species along of the American coast may reflect the expansion of the range of O. puntactus through larval dispersal in northward flowing currents. We recommend monitoring of this introduced species, and studies of its ecology in West Atlantic areas.

Nós examinamos 308 espécimes do blenídeo Omobranchus punctatus, de origem Indo-Pacífica, depositados em coleções de quatro museus. Os dados de distribuição foram analisados com o objetivo de avaliar a invasão das águas costeiras do Oceano Atlântico nas Américas do Sul e Central. Em sua área de distribuição original, O. punctatus ocorre em ambientes marinhos e estuarinos. Amostragens datadas de 1930 e de 2004 produziram 20 registros da espécie no Atlântico Oeste tropical, incluindo amostras do Panamá, Colômbia, Venezuela, Trinidade e Brasil. Neste trabalho nós apresentamos 17 novos registros em áreas da Venezuela e nordeste do Brasil. O padrão temporal dos dados (1930-2009) e a proximidade da maioria das áreas de amostragem a regiões portuárias indicam que a espécie foi inicialmente introduzida no Atlântico pela água de lastro de navios navegando na rota India-Trinidade. No Brasil, a introdução parece estar associada ao movimento de navios em torno das plataformas de petróleo. No Maranhão e no Pará, a introdução está associada ao movimento de navios entre os portos próximos à foz do rio Amazonas. Alternativamente, a expansão de área desta espécie ao longo da costa da América pode ter acontecido através de dispersão larval, acompanhando as correntes em direção ao norte. Nós recomendamos o monitoramento desta espécie, bem como o desenvolvimento de estudos sobre sua ecologia em ambientes do Atlântico ocidental agora ocupos por ela.