Modeling of Photocurrent in Planar Organic Solar Cells

International audienceThis work deals with the modeling of photocurrent in organic solar cells, taking into account simultaneously collection probability and exciton generation rate in the active layers. A simple model for collection probability in the active layers is presented, which takes into account the exciton diffusion length and the distance to the interfaces. Interface passivation is also considered in the model. The influence of exciton diffusion length on device optimization is analyzed

Pawikan on FB: Facebook as a Source of Information on the Current State of Sea Turtles in the Philippines with an Emphasis on Mortality

Sea turtles or “pawikan” are threatened and protected species in the Philippines. In fact, since 1979, the Philippine government has enacted several laws and policies and implemented programs for the conservation of the five of the seven species of sea turtles that could be found in the Philippines. However, reports on poaching, egg collecting, stranding, by-catch, and even slaughtering of sea turtles become more evident than ever, especially on social media (SM) despite these efforts. SM has proven to be one of the most effective platforms for information sharing as anyone who has an account, and an internet connection could easily share information. This study will present data on the threats facing sea turtles in the Philippines by analyzing Facebook (FB) posts of organizations, communities, and individuals about sea turtles from 2008-2019. Only posts that contain visual evidence such as photos and/or videos will be considered. Information on the species, location, and status of the sea turtles will be provided. Moreover, the mortality causes for dead specimens will also be presented. Furthermore, to determine the awareness of the public on the status of sea turtles as threatened and protected species, sentiment analysis will be done to the reactions, comments, and opinions on every post that will be considered in the study.2020-02-1

An analysis of the effectiveness of Quisqualis indica L. (Niyog-Niyogan) stem and leaf ethanolic extracts as antimicrobial agents against common pathogens Escherichia coli and Salmonella typhi

The plant locally referred to as niyog-niyogan has been known to posssess pharmacologic activity. The part of the plant with the most active phytochemicals are the flowers. There have been extended studies performed on the flowers of the plant thus the study focused on the leaves and stem to determine if pharmacologic activity may be comparable through an experimental determination of the Quisualis indica Linn. minimum inhibitory concentration and minimum bactericidal concentration. Herbal extraction, maceration with 95% ethanol and ROTAVAP extraction was performed on the sample for a standard agar dilution test. The inhibitory property exhibited by the Quisqualis leaf extract, was significant in inhibiting the growth of E. coli and S. typhi. Both extracts exhibited antimicrobial properties, but the leaf extracts possessed a greater antimicrobial property than the stems

Treating missing values in INAR(1) models

Time series models for count data have found increased interest in recent days. The existing literature refers to the case of data that have been fully observed. In the present paper, methods for estimating the parameters of the first-order integer-valued autoregressive model in the presence of missing data are proposed. The first method maximizes a conditional likelihood constructed via the observed data based on the k-step-ahead conditional distributions to account for the gaps in the data. The second approach is based on an iterative scheme where missing values are imputed in order to update the estimated parameters. The first method is useful when the predictive distributions have simple forms. We derive in full details this approach when the innovations are assumed to follow a finite mixture of Poisson distributions. The second method is applicable when there are not closed form expressions for the conditional likelihood or they are hard to derive. Simulation results and comparisons of the methods are reported. The proposed methods are applied to a data set concerning syndromic surveillance during the Athens 2004 Olympic Games

The random intrinsic fast initial response of two-sided CUSUM charts

Average run length, cumulative sum charts, Gaussian quadrature, Markov chains, run-length distribution, statistical process control, AMS subject classification, 62N10, 60J20, 62L15,

A tale of worldwide success: Behind the scenes of Carex (Cyperaceae) biogeography and diversification

Martin-Bravo S, Jimenez-Mejias P, Villaverde T, et al. A tale of worldwide success: Behind the scenes of Carex (Cyperaceae) biogeography and diversification. JOURNAL OF SYSTEMATICS AND EVOLUTION. 2019;57(6):695-718.The megadiverse genus Carex (c. 2000 species, Cyperaceae) has a nearly cosmopolitan distribution, displaying an inverted latitudinal richness gradient with higher species diversity in cold-temperate areas of the Northern Hemisphere. Despite great expansion in our knowledge of the phylogenetic history of the genus and many molecular studies focusing on the biogeography of particular groups during the last few decades, a global analysis of Carex biogeography and diversification is still lacking. For this purpose, we built the hitherto most comprehensive Carex-dated phylogeny based on three markers (ETS-ITS-matK), using a previous phylogenomic Hyb-Seq framework, and a sampling of two-thirds of its species and all recognized sections. Ancestral area reconstruction, biogeographic stochastic mapping, and diversification rate analyses were conducted to elucidate macroevolutionary biogeographic and diversification patterns. Our results reveal that Carex originated in the late Eocene in E Asia, where it probably remained until the synchronous diversification of its main subgeneric lineages during the late Oligocene. E Asia is supported as the cradle of Carex diversification, as well as a "museum" of extant species diversity. Subsequent "out-of-Asia" colonization patterns feature multiple asymmetric dispersals clustered toward present times among the Northern Hemisphere regions, with major regions acting both as source and sink (especially Asia and North America), as well as several independent colonization events of the Southern Hemisphere. We detected 13 notable diversification rate shifts during the last 10My, including remarkable radiations in North America and New Zealand, which occurred concurrently with the late Neogene global cooling, which suggests that diversification involved the colonization of new areas and expansion into novel areas of niche space