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Fluorescence, the absorption of short-wavelength electromagnetic radiation reemitted at longer wavelengths, has been suggested to play several biological roles in metazoans. This phenomenon is uncommon in tetrapods, being restricted mostly to parrots and marine turtles. We report fluorescence in amphibians, in the tree frog Hypsiboas punctatus, showing that fluorescence in living frogs is produced by a combination of lymph and glandular emission, with pigmentary cell filtering in the skin. The chemical origin of fluorescence was traced to a class of fluorescent compounds derived from dihydroisoquinolinone, here named hyloins. We show that fluorescence contributes 18−29% of the total emerging light under twilight and nocturnal scenarios, largely enhancing brightness of the individuals and matching the sensitivity of night vision in amphibians. These results introduce an unprecedented source of pigmentation in amphibians and highlight the potential relevance of fluorescence in visual perception in terrestrial environments.Amphibia | Anura | Hylidae | visual ecology | fluorophore F luorescence occurs when short-wavelength electromagnetic radiation is absorbed and then reemitted at longer wavelength. This phenomenon is broadly distributed in marine and terrestrial environments and is found in distantly related organisms (1). Among aquatic vertebrates, fluorescence is widespread phylogenetically within cartilaginous and ray-finned fishes (2) and has been documented in sea turtles (3), whereas among terrestrial vertebrates, it is only known to occur in parrots (4). With few exceptions (5-7), the molecular basis of most of those reports remains unstudied. Many roles have been suggested for fluorescence in animals, such as photoprotection (8), antioxidation (9), and visual communication (10)(11)(12)(13)(14).Amphibians (frogs, toads, salamanders, newts, and caecilians) have a wide range of skin coloration (15) caused by an integumental pigmentary system in which the combination of different types of chromatophore cells create coloration through the integration of chemical and structural features (16). Although the chemical nature and distribution of chromophores has been studied (16), fluorescence has not been reported in any of the 7,600 species of amphibians (17). Here we report a case of fluorescence in this highly diverse group, introduce a class of fluorescent compounds, and assess its importance by quantifying its contribution to overall coloration under natural light conditions. Results and DiscussionFluorescence in Hypsiboas punctatus. The South American tree frog H. punctatus (Family Hylidae) is unusual among amphibians in possessing a translucent skin, a crystal-containing layer in the peritonea and bladder, and a high concentration of biliverdin in lymph and tissues. We observed that living adults and juveniles illuminated with UV-A blue light produced a bright blue/green fluorescent emission (Fig. 1 A-C) that was clearly discernible from the body surface of the specimens. To characterize the fluorescence of f...

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International audienceAs the supply chains get more complex, the variety of indicators and tools to measure warehouse performance has alsoincreased. Furthermore, the metrics that are used for performance evaluation are assessed in different manners and hencethere is not clear definition for some of these metrics. To address these issues, this literature review focuses on operationalwarehouse performance measurement, for which the warehouse managers need to carry out periodic analysis. Using thecontent analysis method, performance indicators are acquired from selected papers and are classified according to time, cost,quality and productivity dimensions. The contributions of this literature review are as follows: we present a synthesis of theliterature on operational warehouse performance, we provide the definitions for the performance indicators and a frameworkto demonstrate their boundaries and, finally, based on the literature analysis, we also provide some discussions on currenttrends in warehouses and propose future research directions on warehouse performance evaluation

Economic activity today is still based on a linear model of production and consumption: extract/produce and consume/throw, which exhausts natural resources and generates waste. The current linear economy does not optimize materials nor favour their recycling, reuse or recovery. Hence, the concept of Circular Economy (CE) has received increasing attention between policymakers and stakeholders worldwide. However, the literature on CE was mainly developed for the manufacturing sector, and only a few references are found on the tourism sector even though it is a sector where huge consumption of energy and water, food waste, congestion problems and CO2 emissions take place. This work aims to evaluate the importance of tourism in the CE literature and to identify current research trends and possible gaps in the literature on CE and tourism. In order to identify papers for this, the authors carried out a literature review of papers in the social science citation index (Web of Science) and Scopus. The keywords used are related to the tourism sector and CE, and the last search was made at the end of January 2020. Only papers published in English have been considered in the sample, which totals to 55 articles. Each contribution is analysed and, according to its content, classified into eight streams; then, the paper identifies two knowledge areas in tourism that this scientific production covers and the areas with lack of knowledge generated. Findings show that more research is needed about tourism’s intersection with CE in order to generate possible solutions towards a more sustainable tourism industry.

All living organisms emit, detect, and respond to chemical stimuli, thus creating an almost limitless number of interactions by means of chemical signals. Technological and intellectual advances in the last two decades have enabled chemical signals analyses at several molecular levels, including gene expression, molecular diversity, and receptor affinity. These advances have also deepened our understanding of nature to encompass interactions at multiple organism levels across different taxa. This tutorial review describes the most recent analytical developments in 'omics' technologies (i.e., genomics, transcriptomics, proteomics, and metabolomics) and provide recent examples of its application in studies of chemical signals. We highlight how studies have integrated an enormous amount of information generated from different omics disciplines into one publicly available platform. In addition, we stress the importance of considering different signal modalities and an evolutionary perspective to establish a comprehensive understanding of chemical communication.

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