Continued availability and sale of pangolins in a major urban bushmeat market in Cameroon despite national bans and the COVID-19 outbreak

First paragraph: Bushmeat (or ‘wild meat’, defined as the meat of wild animals) is a major source of protein for rural people across sub-Saharan Africa (Ingram et al., 2021), yet some species suffer unsustainable levels of exploitation often to meet the demands of increasing urban populations (Coad et al., 2019; Wilkie et al., 2016). As in the rest of Central Africa, Cameroon has a long history of bushmeat consumption and trade (Bahuchet & Ioveva, 1999; Randolph, 2016). Pangolins (Family: Manidae) have been one of the many groups of species exploited as they are highly valued for food and, in some countries, used as traditional remedies (Soewu et al., 2020). Pangolin meat is favoured for its taste and it remains commonly offered for sale in Cameroonian markets and restaurants (Ingram et al., 2018; Nguyen et al., 2021). Furthermore, Cameroon has become one of the major export countries for the illegal trade in pangolin scales from Africa to Asia (Ingram et al., 2019a), to supply the market for Asian traditional medicines, for example in traditional Chinese medicine (Wang et al., 2020). All African pangolin species are now considered to have declining population trends (Ingram et al., 2019b; Nixon et al., 2019; Pietersen et al., 2019a, 2019b)

Crop pests and predators exhibit inconsistent responses to surrounding landscape composition

The idea that noncrop habitat enhances pest control and represents a win–win opportunity to conserve biodiversity and bolster yields has emerged as an agroecological paradigm. However, while noncrop habitat in landscapes surrounding farms sometimes benefits pest predators, natural enemy responses remain heterogeneous across studies and effects on pests are inconclusive. The observed heterogeneity in species responses to noncrop habitat may be biological in origin or could result from variation in how habitat and biocontrol are measured. Here, we use a pest-control database encompassing 132 studies and 6,759 sites worldwide to model natural enemy and pest abundances, predation rates, and crop damage as a function of landscape composition. Our results showed that although landscape composition explained significant variation within studies, pest and enemy abundances, predation rates, crop damage, and yields each exhibited different responses across studies, sometimes increasing and sometimes decreasing in landscapes with more noncrop habitat but overall showing no consistent trend. Thus, models that used landscape-composition variables to predict pest-control dynamics demonstrated little potential to explain variation across studies, though prediction did improve when comparing studies with similar crop and landscape features. Overall, our work shows that surrounding noncrop habitat does not consistently improve pest management, meaning habitat conservation may bolster production in some systems and depress yields in others. Future efforts to develop tools that inform farmers when habitat conservation truly represents a win–win would benefit from increased understanding of how landscape effects are modulated by local farm management and the biology of pests and their enemies

Wake-Up RF Communication Node Design and Use for Communal Living and Emergency Alert in Remote Areas of Developing Countries

International audienceWe proposed in this paper a free communication system for restoring a communal living and a minimum autonomy of operating in remote areas of developing countries. This system also intends to restore the return to local values, to strengthen the links between the populations, and to facilitate communication during epidemic or arm robber’s attacks in remote localities of developing countries; it also helps in a follow up of old people. Commercial Off-The-Shelf (COTS) components are used for global system nodes design. A covered area of 260m is reached and can be extended with dedicated additional antenna

The Mount Cameroon stratovolcano (Cameroon Volcanic Line, Central Africa): Petrology, geochemistry, isotope and age data

International audienceMount Cameroon, a Plio-Quaternary stratovolcano, is the most important volcano along the Cameroon Volcanic Line, located at the boundary between the continental and oceanic lithosphere. Effusive, explosive and hydromagmatic eruptions were the three main types of volcanic activity. Mount Cameroon has a weakly differentiated alkaline series: mainly basanites, alkaline basalts, hawaiites, and mugearites. Mount Cameroon lavas are a typical alkaline series, characteristic of the interior of plates: high TiO$_2$ contents (2.4-3.7 wt.%), Na$_2$O between 2.9 and 5.2 wt.%, K$_2$O between 1.1 and 3.0 wt.%. Trace element patterns confirm the general evolution by fractional crystallization from a source in a mantle plume. Magmas beneath Mount Cameroon were generated at great depths from a garnet-lherzolite mantle, with an additional contribution from spinel-lherzolite, with small amounts (0.2-2 %) of melting. $^{40}$ K-$^{40}$Ar analyses have yielded ages of 2.83 to 0 Ma. The $^{87}$Sr/$^{86}$Sr ratios of mafic lavas are low (0.703198-0.703344), and $^{143}$Nd/ $^{144}$Nd ratios are intermediate (0.512851-0.512773), as typical of a mantle origin with a HIMU component. $^{206}$Pb/$^{204}$Pb, $^{207}$Pb/$^{204}$Pb and $^{208}$Pb/$^{204}$Pb ratios are respectively 18.8270-20.3911, 15.5999-15.6793 and 40.2093-38.6517

Can deuterium stable isotope values be used to assign the geographicorigin of an auxiliary hoverfly in south-western France?

International audienc

Can Deuterium stable isotopes be used to infer geographical origins of an auxiliary hoverfly and a pest moth?

Deuterium δD isotopic analysis is increasingly being used to trace wildlife movement, and undoubtedly has much to offer in this respect but questions still remain as to the feasibility and practicality of the method in ecology. Here we report our attempt to determine the geographic origin of an auxiliary hoverfly, Episyrphus balteatus, in South-western France and a pest moth, Helicoverpa armigera in Western Africa. We used quantile regression to calculate the minimum separation distance, based on the International Atomic Energy Agency / World Meteorological Organization (IAEA / WMO) data, at which two insects could be said to originate from different latitudes with a given degree of confidence. Our results revealed greater variability of hoverfly adults δD in autumn than in spring. From this we infer an autumnal migration of the auxiliary hoverfly species. Despite the complications encountered in Europe, the minimum separation distance model proved a useful first step to get a first range of possible origins of E. balteatus and its application to other arthropod species in Europe warrants investigation. The lack of IAEA /WMO data in western Africa prevents the calculation of a minimum separation distance for the pest moth. The interpretation of water simulated δD in the study area in Western Africa and preliminary results on wild moth advocate for a restricted use of stable isotope to infer the geographical origin of the pest moth

A Novel Compound-Coupled Hyperchaotic Map for Image Encryption

Considering a nonlinear dynamic oscillator, a high Lyapunov exponent indicates a high degree of randomness useful in many applications, including cryptography. Most existing oscillators yield very low Lyapunov exponents. The proposed work presents a general strategy to derive an n-D hyperchaotic map with a high Lyapunov exponent. A 2D case study was analyzed using some well-known nonlinear dynamic metrics including phase portraits, bifurcation diagrams, finite time Lyapunov exponents, and dimension. These metrics indicated that the state of the novel map was more scattered in the phase plane than in the case of some traditional maps. Consequently, the novel map could produce output sequences with a high degree of randomness. Another important observation was that the first and second Lyapunov exponents of the proposed 2D map were both positive for the whole parameter space. Consequently, the attractors of the map could be classified as hyperchaotic attractors. Finally, these hyperchaotic sequences were exploited for image encryption/decryption. Various validation metrics were exploited to illustrate the security of the presented methodology against cryptanalysts. Comparative analysis indicated the superiority of the proposed encryption/decryption protocol over some recent state-of-the-art methods

Evaluation of Polylactic Acid Polymer as a Substrate in Rectenna for Ambient Radiofrequency Energy Harvesting

This work details the design and experimental characterization of a 2D rectenna for scavenging radio frequency energy at 2.45 GHz (WiFi band), fabricated on polylactic acid polymer (PLA) using a plastronics approach. PLA is the RF substrate of both antenna and rectifier. The two transmission line (TTL) approach is used to characterize the substrate properties to be considered during design. A linearly polarized patch antenna with microstrip transmission feeding is connected to a single series diode rectifier through a T-matching network. The antenna has simulated and measured gain of 7.6 dB and 7.5 dB, respectively. The rectifier has a measured DC output power of 0.96 μW at an optimal load of 2 kΩ under RF input power of −20 dBm at 2.45 GHz. The power conversion efficiency is 9.6% in the latter conditions for a 54 × 36 mm patch antenna of a 1.5 mm thick PLA substrate obtained from additive manufacturing. The power conversion efficiency reaches a value of 28.75% when the input power is −10 dBm at 2.45 GHz. This corresponds to a peak DC power of 28.75 μW when the optimal load is 1.5 kΩ. The results compare significantly with the ones of a similar rectenna circuit manufactured on preferred RF substrate

A genome-wide investigation of the worldwide invader Sargassum muticum shows high success albeit (almost) no genetic diversity

Twenty years of genetic studies of marine invaders have shown that successful invaders are often characterized by native and introduced populations displaying similar levels of genetic diversity. This pattern is presumably due to high propagule pressure and repeated introductions. The opposite pattern is reported in this study of the brown seaweed, Sargassum muticum, an emblematic species for circumglobal invasions. Albeit demonstrating polymorphism in the native range, microsatellites failed to detect any genetic variation over 1,269 individuals sampled from 46 locations over the Pacific-Atlantic introduction range. Single-nucleotide polymorphisms (SNPs) obtained from ddRAD sequencing revealed some genetic variation, but confirmed severe founder events in both the Pacific and Atlantic introduction ranges. Our study thus exemplifies the need for extreme caution in interpreting neutral genetic diversity as a proxy for invasive potential. Our results confirm a previously hypothesized transoceanic secondary introduction from NE Pacific to Europe. However, the SNP panel unexpectedly revealed two additional distinct genetic origins of introductions. Also, conversely to scenarios based on historical records, southern rather than northern NE Pacific populations could have seeded most of the European populations. Finally, the most recently introduced populations showed the lowest selfing rates, suggesting higher levels of recombination might be beneficial at the early stage of the introduction process (i.e., facilitating evolutionary novelties), whereas uniparental reproduction might be favored later in sustainably established populations (i.e., sustaining local adaptation).Agence Nationale de la Recherche - ANR-10-BTBR-04; European Regional Development Fund; Fundacao para a Ciencia e a Tecnologia - SFRH/BPD/107878/2015, UID/Multi/04326/2016, UID/Multi/04326/2019; Brittany Region;info:eu-repo/semantics/publishedVersio