Efficient and automatic methods for flexible regression on spatiotemporal data, with applications to groundwater monitoring

Fitting statistical models to spatiotemporal data requires finding the right balance between imposing smoothness and following the data. In the context of P-splines, we propose a Bayesian framework for choosing the smoothing parameter which allows the construction of fully-automatic data-driven methods for fitting flexible models to spatiotemporal data. An implementation, which is highly computationally efficient and which exploits the sparsity of the design and penalty matrices, is proposed. The findings are illustrated using a simulation study and two examples, all concerned with the modelling of contaminants in groundwater. This suggests that the proposed strategy is more stable that competing methods based on the use of criteria such as GCV and AIC

The number and profile of reactive NADH-d and NADPH-d neurons of myenteric plexus of six-month-old rats are different in the cecum portions

Whole-mount preparations were prepared and submitted to NADH-diaphorase and NADPH-diaphorase histochemistry techniques. The myenteric plexus arrangement and the number of neurons were comparatively evaluated among the different portions of the cecum. The neurons from the apical and basal regions were distributed in classes at intervals of 100µm², the means of the corresponding intervals being compared. The ganglia, in both techniques, were often connected by fine bundles, which became thicker in the mesenteric region and in the region next to the cecal ampulla. The number of positive NADH-d neurons was higher than that of NADPH-d neurons in all portions, from both regions. The numbers of reactive NADH-d e NADPH-d neurons were significantly different among the different portions of the cecum, except for the antimesenteric basal and intermediate basal regions, considering the NADH-d neurons. The profile area for the reactive NADH-d e NADPH-d neurons was higher in the apical region than in the basal area. Differences in arrangement, distribution and size of positive NADH-d e NADPH-d neurons in the different cecum portions evidenced the importance of the subdivision of the analyzed organ.Estudaram-se o arranjo do plexo mioentérico, o número de neurônios e a área do perfil do corpo celular (µm²) dos neurônios mioentéricos, nas regiões apical e basal do ceco de ratos Wistar com 6 meses de idade. Estas regiões foram subdivididas nas seguintes porções: apical mesentérica (AM); apical intermediária (AI); apical antimesentérica (AA); próximo à ampola cecal (PA); basal intermediária (BI), e basal antimesentérica (BA). Foram montados preparados de membrana que receberam as técnicas histoquímica de NADH-diaforase (NADH-d) e NADPH-diaforase (NADPH-d). O arranjo do plexo mioentérico e o número de neurônios foram avaliados comparativamente entre as diferentes porções das regiões do ceco. Os neurônios das regiões apical e basal foram distribuídos em classes com intervalos de 100µm², sendo comparadas às médias da mensuração dos pares. Os gânglios, em ambas as técnicas, apresentavam-se, em geral, conectados por feixes delicados, tornando-se mais espessos na porção mesentérica e naquela próxima à ampola cecal. O número de neurônios NADH-d positivos foi maior do que o de NADPH-d em todas as porções, de ambas as regiões. O número de neurônios reativos a NADH-d e NADPH-d foi significativamente diferente entre as diferentes porções do ceco, com exceção das comparações entre as porções basal antimesentérica e basal intermediária, para os primeiros; e entre a basal intermediária e porção próxima à ampola cecal, e comparando-se a apical mesentérica e porção próxima à ampola cecal, para os neurônios NADPH-d positivos. A área do perfil dos neurônios NADH-d e NADPH-d reativos foi maior na região apical do que na basal. Pela primeira vez, o número de neurônios do plexo mioentérico é reportado em porções pré-estabelecidas do ceco de ratos. Nossos resultados reiteram a importância da indicação precisa da porção estudada em pesquisas envolvendo este segmento intestinal

A pair of tess planets spanning the radius valley around the nearby mid-m dwarf ltt 3780

We present the confirmation of two new planets transiting the nearby mid-M dwarf LTT 3780 (TIC 36724087, TOI-732, V = 13.07, K s = 8.204, R s = 0.374 R o˙, M s = 0.401 M o˙, d = 22 pc). The two planet candidates are identified in a single Transiting Exoplanet Survey Satellite sector and validated with reconnaissance spectroscopy, ground-based photometric follow-up, and high-resolution imaging. With measured orbital periods of P b = 0.77, P c = 12.25 days and sizes r p,b = 1.33 ± 0.07, r p,c = 2.30 ± 0.16 R ⊕, the two planets span the radius valley in period-radius space around low-mass stars, thus making the system a laboratory to test competing theories of the emergence of the radius valley in that stellar mass regime. By combining 63 precise radial velocity measurements from the High Accuracy Radial velocity Planet Searcher (HARPS) and HARPS-N, we measure planet masses of mpb 2.62+ 0.48 and-0.46= mpc 8.6+1.6-1.3 M⊕, which indicates that LTT 3780b has a bulk composition consistent with being Earth-like, while LTT 3780c likely hosts an extended H/He envelope. We show that the recovered planetary masses are consistent with predictions from both photoevaporation and core-powered mass-loss models. The brightness and small size of LTT 3780, along with the measured planetary parameters, render LTT 3780b and c as accessible targets for atmospheric characterization of planets within the same planetary system and spanning the radius valley

Building scientific workflows for Earth system modelling with Windows Workflow Foundation

The GENIE project has built a Grid enabled framework that facilitates the integration, execution and management of component models for the study of the Earth system over millennial timescales. The existing framework supports collaborative study of GENIE models across heterogeneous compute grids through scripted workflows in the Matlab environment. In this paper, Windows Workflow Foundation technologies are applied to demonstrate the benefits of an environment that provides rapid composition, event driven logic and reliable hosting of scientific workflows. These improvements are demonstrated through a parametric study of bistability of the oceanic thermohaline circulation in a GENIE model

Modified Kocks-Mecking-Estrin Model to Account Nonlinear Strain Hardening

The dislocation density-based model after Kocks-Mecking-Estrin (KME) is widely used to characterize the thermally activated plastic deformation and dislocation kinetics. According to the model, the slope of the stress-strain curve decreases linearly with stress, which contradicts the experimental observation. In the current study, the evolution of dislocation density in the model is generalized to account for the nonlinearity of the slope.11Nsciescopu