On the manipulability of dual cooperative robots

The definition of manipulability ellipsoids for dual robot systems is given. A suitable kineto-static formulation for dual cooperative robots is adopted which allows for a global task space description of external and internal forces, and relative velocities. The well known concepts of force and velocity manipulability ellipsoids for a single robot are formally extended and the contributions of the two single robots to the cooperative system ellipsoids are illustrated. Duality properties are discussed. A practical case study is developed

24,4,8-Trioxa-21-aza-1,3,6(1,2)-tri­benzena-2(2,3)-bicyclo­[3.3.0]octa­na­cyclo­octa­phane

The crystal structure of the title compound, C26H25NO3, was determined as part of an investigation of host–guest and electron donor–acceptor complexes. The oxazole and the pyrrole rings both adopt envelope conformations. The dihedral angle between the two benzene rings directly linked to the oxazole ring is 49.5 (1)°. The crystal structure is stabilized by a C—H⋯π inter­action

Tropical cyclone activity enhanced by Sahara greening and reduced dust emissions during the African Humid Period

Tropical cyclones (TCs) can have devastating socioeconomic impacts. Understanding the nature and causes of their variability is of paramount importance for society. However, historical records of TCs are too short to fully characterize such changes and paleo-sediment archives of Holocene TC activity are temporally and geographically sparse. Thus, it is of interest to apply physical modeling to understanding TC variability under different climate conditions. Here we investigate global TC activity during a warm climate state (mid-Holocene, 6,000 yBP) characterized by increased boreal summer insolation, a vegetated Sahara, and reduced dust emissions. We analyze a set of sensitivity experiments in which not only solar insolation changes are varied but also vegetation and dust concentrations. Our results show that the greening of the Sahara and reduced dust loadings lead to more favorable conditions for tropical cyclone development compared with the orbital forcing alone. In particular, the strengthening of the West African Monsoon induced by the Sahara greening triggers a change in atmospheric circulation that affects the entire tropics. Furthermore, whereas previous studies suggest lower TC activity despite stronger summer insolation and warmer sea surface temperature in the Northern Hemisphere, accounting for the Sahara greening and reduced dust concentrations leads instead to an increase of TC activity in both hemispheres, particularly over the Caribbean basin and East Coast of North America. Our study highlights the importance of regional changes in land cover and dust concentrations in affecting the potential intensity and genesis of past TCs and suggests that both factors may have appreciable influence on TC activity in a future warmer climate.National Science Foundation (U.S.) (Grant AGS-1461517

Distant but similar: Simultaneous drop in the abundance of three independent amphibian communities

Amphibian species are declining worldwide, with a negative trend affecting both rare and widespread species. There is increasing evidence that resources must be allocated not only toward the monitoring of rare and charismatic species; however, the attention toward abundant species has often been minimal. Here, we describe the strong reduction in the numbers of several widespread amphibian species over the last 3 years observed in three independent amphibian monitoring studies conducted in an alpine, floodplain, and urban landscape in Italy, Germany, and Russia, respectively. The decline was particularly strong in juveniles, but adults and egg clutches were also affected. Such declining rates, if prolonged in the future years, will likely pose a serious threat to the populations' ability to recover and might increase extinction risk also in abundant and widespread species. © 2022 The Authors. Conservation Science and Practice published by Wiley Periodicals LLC on behalf of Society for Conservation Biology.European Herpetological SocietyInstitute of Plant and Animal EcologyItalian Ministry of Environment, (PNM‐EU‐2018‐0009926)Paneveggio-Pale di San Martino Nature ParkPaneveggio‐Pale di San Martino Nature ParkSEH, (DP‐615, RA‐485/19)Ural Branch, Russian Academy of Sciences, UB RASFunding text 1: The study in Italy was authorized by the Italian Ministry of Environment (authorization PNM-EU-2018-0009926) and supported by Paneveggio-Pale di San Martino Nature Park. Part of funding was provided by the European Herpetological Society (SEH). The study in Germany has been authorized through a nature conservation exemption from the prohibitions of § 44 para. 1 no. 1, 2 BNatSchG (Federal Nature Conservation Act) and § 4 para. 1 no. 1 BArtSchV (Federal Species Protection Ordinance) by the respective responsible lower nature conservation authorities that allowed catching and handling native amphibian species. Parts of the research in Germany have been paid through the Helmholtz International Fellow Award, grant number DP-615, RA-485/19. The study in Russia was performed within the framework of the state contract number 122021000082-0 with the Institute of Plant and Animal Ecology, Ural Branch of the Russian Academy of Sciences.Funding text 2: The study in Italy was authorized by the Italian Ministry of Environment (authorization PNM‐EU‐2018‐0009926) and supported by Paneveggio‐Pale di San Martino Nature Park. Part of funding was provided by the European Herpetological Society (SEH). The study in Germany has been authorized through a nature conservation exemption from the prohibitions of § 44 para. 1 no. 1, 2 BNatSchG (Federal Nature Conservation Act) and § 4 para. 1 no. 1 BArtSchV (Federal Species Protection Ordinance) by the respective responsible lower nature conservation authorities that allowed catching and handling native amphibian species. Parts of the research in Germany have been paid through the Helmholtz International Fellow Award, grant number DP‐615, RA‐485/19. The study in Russia was performed within the framework of the state contract number 122021000082‐0 with the Institute of Plant and Animal Ecology, Ural Branch of the Russian Academy of Sciences

New tools for detecting latent tuberculosis infection: evaluation of RD1-specific long-term response

<p>Abstract</p> <p>Background</p> <p>Interferon-gamma (IFN-γ) release assays (IGRAs) were designed to detect latent tuberculosis infection (LTBI). However, discrepancies were found between the tuberculin skin test (TST) and IGRAs results that cannot be attributed to prior Bacille Calmètte Guerin vaccinations. The aim of this study was to evaluate tools for improving LTBI diagnosis by analyzing the IFN-γ response to RD1 proteins in prolonged (long-term response) whole blood tests in those subjects resulting negative to assays such as QuantiFERON-TB Gold In tube (QFT-IT).</p> <p>Methods</p> <p>The study population included 106 healthy TST⁺individuals with suspected LTBI (recent contact of smear-positive TB and homeless) consecutively enrolled. As controls, 13 healthy subjects unexposed to <it>M. tuberculosis </it>(TST^-, QFT-IT^-) and 29 subjects with cured pulmonary TB were enrolled. IFN-γ whole blood response to RD1 proteins and QFT-IT were evaluated at day 1 post-culture. A prolonged test evaluating long-term IFN-γ response (7-day) to RD1 proteins in diluted whole blood was performed.</p> <p>Results</p> <p>Among the enrolled TST⁺subjects with suspected LTBI, 70/106 (66.0%) responded to QFT-IT and 64/106 (60.3%) to RD1 proteins at day 1. To evaluate whether a prolonged test could improve the detection of LTBI, we set up the test using cured TB patients (with a microbiologically diagnosed past pulmonary disease) who resulted QFT-IT-negative and healthy controls as comparator groups. Using this assay, a statistically significant difference was found between IFN-γ levels in cured TB patients compared to healthy controls (p < 0.006). Based on these data, we constructed a receiver operating characteristic (ROC) curve and we calculated a cut-off. Based on the cut-off value, we found that among the 36 enrolled TST+ subjects with suspected LTBI not responding to QFT-IT, a long term response to RD1 proteins was detected in 11 subjects (30.6%).</p> <p>Conclusion</p> <p>These results indicate that IFN-γ long-term response to <it>M. tuberculosis </it>RD1 antigens may be used to detect past infection with <it>M. tuberculosis </it>and may help to identify additional individuals with LTBI who resulted negative in the short-term tests. These data may provide useful information for improving immunodiagnostic tests for tuberculosis infection, especially in individuals at high risk for active TB.</p