1,362 research outputs found
The COVID-19 Pandemic Endangers Africa’s Indigenous Pygmy Populations
Forest-dependent populations are affected by environmental pressures that include deforestation and forest degradation. Their lives and livelihoods have also been transformed by political decisions in the countries where they live. In Africa, the Pygmy peoples living in the dense tropical forests (4 million km2) that span west–east along the central African belt of the Congo Basin are made up of genetically and ethno-linguistically distinct groups (Bahuchet 2014). They are broadly subdivided into western groups, including Baka and Aka, and eastern groups including Mbuti, Efe, and Asua. All have a similar way of life associated with forest hunting and gathering even though some have taken up some form of agriculture. Additionally to their mode of subsistence, they share distinctive cultural and phenotypic traits such as the “Pygmy phenotype” of small adult body size (Perry and Dominy 2009). The demographic and evolutionary split between Pygmy and non-Pygmy populations is amongst the oldest for modern humans with the divergence estimated from genetic data to be roughly between 60,000 and over 100,000 years ago and the split between Western and Eastern Pygmy groups about 20,000 years ago (Hsieh et al. 2016). The Baka in south-eastern Cameroon, formerly strict hunters-gatherers, still practice a subsistence economy, but also maintain a close association with sedentary Bantu-speaking swidden agriculturalists with whom they have a complex social, economic, and symbolic relationship (Joiris 1998). Although less isolated than other Pygmy groups, especially the Mbuti and Efe, the Baka, like other forest-dependent populations in the Congo Basin, have been affected by a plethora of environmental pressures that include direct impacts from extractive industries (logging, mining), conflict with conservation areas, encroachment into their territories both peacefully along roads or aggressively by poachers and militias, as well as the effects of resettlement and sedentarization (Olivero et al. 2016). Such combination of threats impacts their health and food security. Currently, COVID-19 has reached Africa though apparently with an overall surprisingly low prevalence and mortality (Mbow et al. 2020). We argue that Pygmy communities may be silently ravaged by the disease yet there is a lack of policies or initiatives to monitor their health systematically throughout the Congo Basin. Understanding the impact of COVID-19 on these forest-dependent peoples has never been more important to develop ways of helping them
Attitudes and Perceptions of Local Communities towards Nile Crocodiles (Crocodylus niloticus) in the Sudd Wetlands, South Sudan
Conflicts between human populations and Nile crocodiles are widespread with crocodiles posing significant threats to fisherfolk and riverine communities across r-Saharan Africa. Hundreds of deadly attacks take place annually, and mortality rates may range from 50% to 100%. Attitudes and perceptions towards crocodiles were studied using structured questionnaires among fisherfolk along the River Nile and the Sudd wetlands in South Sudan. Local communities used crocodiles for their meat and skin/leather trades. The meat is regarded to enhance longevity, sexual potency, and protection against witchcraft. Crocodiles are perceived as a main threat to lives and livelihoods as they restrict people’s freedom of movement along water bodies, attack livestock and humans, and devastate fishing equipment. To assess whether responses were influenced by the intensity of crocodile threats, published data on fatal crocodile attacks on humans and livestock were analysed using Generalised Linear Models (GLMs). This analysis indicated a direct link between the number of crocodile attacks and human attitudes. Crocodiles were generally feared and hated, and there was the agreement of the need to destroy breeding habitats. However, some attitudes were complex and nuanced as highlighted by the agreement of local communities on the need to destroy Nile Crocodile breeding habitats on the one hand and the need to establish crocodile sanctuaries as the the preferred strategy to mitigate risks and conflict on the other hand. There is a need for the creation of a crocodile sanctuary in the Sudd wetlands to minimise the risks of illegal hunting and to buffer the increasing pressure on crocodiles due to human population growth and economic upturn after the civil war
Food and livelihoods in park-adjacent communities: The case of the Odzala Kokoua National Park
Protected areas (PAs) in Central Africa provide unprecedented opportunities to maintain ecosystem integrity and safeguard the unique wildlife of one of the most biodiverse regions in the world. However, conflicts exist between wildlife protection, and the needs of human populations adjacent to PAs. Although the use of wildlife resources within PAs is nominally regulated, wildlife exploitation in the areas surrounding parks benefit human nutrition and livelihoods of adjacent populations. In 2013–2014, we interviewed 28% of all known households in 37 villages surrounding the Odzala Kokoua National Park (OKNP), Republic of Congo. We gathered information on bushmeat consumption, income, material assets, and hunter perception of the state of wildlife. We show that bushmeat species (mostly duikers, small monkeys and porcupine) were consumed in 38–48% of meals, and 20–30% of households earned cash from hunting wildlife in most villages; more than any other single source of revenue, except cocoa. Although it remains unknown whether the park was a reservoir for wildlife for areas around the studied villages, we showed that more bushmeat was consumed closer to OKNP. By contrast, income from bushmeat sales in villages closer to markets was greater, and as a corollary, market access and household wealth were positively correlated. Overall, total household income, income from bushmeat sales, travel time, and distance to the OKNP were good predictors of household wealth. Wildlife, although considered more abundant around villages closest to the park, was perceived as generally declining around all village groups. Our results highlight the possible importance of PAs and adjacent areas as reservoirs of wildlife and in maintaining wild meat resources used by the surrounding human populations
After the sunset: the residual effect of temporary legislation
The difference between permanent legislation and temporary legislation is the default rule of termination: permanent legislation governs perpetually, while temporary legislation governs for a limited time. Recent literature on legislative timing rules considers the effect of temporary legislation to stop at the moment of expiration. When the law expires, so does its regulatory effect. This article extends that literature by examining the effect of temporary legislation beyond its expiration. We show that in addition to affecting compliance behavior which depends on statutory enforcement, temporary legislation also affects compliance behavior which does not depend on statutory enforcement, and more generally, organizational behavior after a sunset. When temporary legislation expires therefore, it can continue to administer regulatory and other effects. We specify the conditions for this process and give the optimal legislative response
A westward extension of the warm pool leads to a westward extension of the Walker circulation, drying eastern Africa
Observations and simulations link anthropogenic greenhouse and aerosol emissions with rapidly increasing Indian Ocean sea surface temperatures (SSTs). Over the past 60 years, the Indian Ocean warmed two to three times faster than the central tropical Pacific, extending the tropical warm pool to the west by ~40° longitude (><4,000 km). This propensity toward rapid warming in the Indian Ocean has been the dominant mode of interannual variability among SSTs throughout the tropical Indian and Pacific Oceans (55°E–140°W) since at least 1948, explaining more variance than anomalies associated with the El Niño-Southern Oscillation (ENSO). In the atmosphere, the primary mode of variability has been a corresponding trend toward greatly increased convection and precipitation over the tropical Indian Ocean. The temperature and rainfall increases in this region have produced a westward extension of the western, ascending branch of the atmospheric Walker circulation. Diabatic heating due to increased mid-tropospheric water vapor condensation elicits a westward atmospheric response that sends an easterly flow of dry air aloft toward eastern Africa. In recent decades (1980–2009), this response has suppressed convection over tropical eastern Africa, decreasing precipitation during the ‘long-rains’ season of March–June. This trend toward drought contrasts with projections of increased rainfall in eastern Africa and more ‘El Niño-like’ conditions globally by the Intergovernmental Panel on Climate Change. Increased Indian Ocean SSTs appear likely to continue to strongly modulate the Warm Pool circulation, reducing precipitation in eastern Africa, regardless of whether the projected trend in ENSO is realized. These results have important food security implications, informing agricultural development, environmental conservation, and water resource planning
Testing hypotheses of habitat use and temporal activity in relation to body plan in a mediterranean lizard community
A body plan (bauplan) is a suite of morphological characters shared by phylogenetically related animals at some point during their development. Despite its value, the bauplan concept is still rarely employed to characterize functional groups in community ecology. Here, we examine habitat use and spatio-temporal activity correlates of an entire sevenspecies community of lizards with different bauplans. The study was carried out in three locations in central Italy, encompassing a complex landscape with a patchy mosaic of a wide variety of habitats and microclimates. We tested four hypotheses regarding niche breadth, habitat use, and activity patterns. The first hypothesis, niche complementarity, in which species with similar body shapes should non-randomly partition available habitats, was not supported. By contrast, the hypotheses that larger bodied species should have a wider niche breadth, that slower species should inhabit habitat types of higher cover, and species inhabiting open sunny habitats should exhibit more seasonally variable activity patterns, were all supported by the data. Sympatric lizard communities in our study area were clearly organized by autecological constraints and eco-physiological attributes
Gender and line size factors modulate the deviations of the subjective visual vertical induced by head tilt
<p>Abstract</p> <p>Background</p> <p>The subjective visual vertical (SVV, the visual estimation of gravitational direction) is commonly considered as an indicator of the sense of orientation. The present study examined the impact of two methodological factors (the angle size of the stimulus and the participant's gender) on deviations of the SVV caused by head tilt. Forty healthy participants (20 men and 20 women) were asked to make visual vertical adjustments of a light bar with their head held vertically or roll-tilted by 30° to the left or to the right. Line angle sizes of 0.95° and 18.92° were presented.</p> <p>Results</p> <p>The SVV tended to move in the direction of head tilt in women but away from the direction of head tilt in men. Moreover, the head-tilt effect was also modulated by the stimulus' angle size. The large angle size led to deviations in the direction of head-tilt, whereas the small angle size had the opposite effect.</p> <p>Conclusions</p> <p>Our results showed that gender and line angle size have an impact on the evaluation of the SVV. These findings must be taken into account in the growing body of research that uses the SVV paradigm in disease settings. Moreover, this methodological issue may explain (at least in part) the discrepancies found in the literature on the head-tilt effect.</p
Phylogeny and Classification of the Trapdoor Spider Genus Myrmekiaphila: An Integrative Approach to Evaluating Taxonomic Hypotheses
Background: Revised by Bond and Platnick in 2007, the trapdoor spider genus Myrmekiaphila comprises 11 species. Species delimitation and placement within one of three species groups was based on modifications of the male copulatory device. Because a phylogeny of the group was not available these species groups might not represent monophyletic lineages; species definitions likewise were untested hypotheses. The purpose of this study is to reconstruct the phylogeny of Myrmekiaphila species using molecular data to formally test the delimitation of species and species-groups. We seek to refine a set of established systematic hypotheses by integrating across molecular and morphological data sets. Methods and Findings: Phylogenetic analyses comprising Bayesian searches were conducted for a mtDNA matrix composed of contiguous 12S rRNA, tRNA-val, and 16S rRNA genes and a nuclear DNA matrix comprising the glutamyl and prolyl tRNA synthetase gene each consisting of 1348 and 481 bp, respectively. Separate analyses of the mitochondrial and nuclear genome data and a concatenated data set yield M. torreya and M. millerae paraphyletic with respect to M. coreyi and M. howelli and polyphyletic fluviatilis and foliata species groups. Conclusions: Despite the perception that molecular data present a solution to a crisis in taxonomy, studies like this demonstrate the efficacy of an approach that considers data from multiple sources. A DNA barcoding approach during the species discovery process would fail to recognize at least two species (M. coreyi and M. howelli) whereas a combine
Thyrotropin-releasing hormone (TRH) promotes wound re-epithelialisation in frog and human skin
There remains a critical need for new therapeutics that promote wound healing in patients suffering from chronic skin wounds. This is, in part, due to a shortage of simple, physiologically and clinically relevant test systems for investigating candidate agents. The skin of amphibians possesses a remarkable regenerative capacity, which remains insufficiently explored for clinical purposes. Combining comparative biology with a translational medicine approach, we report the development and application of a simple ex vivo frog (Xenopus tropicalis) skin organ culture system that permits exploration of the effects of amphibian skin-derived agents on re-epithelialisation in both frog and human skin. Using this amphibian model, we identify thyrotropin-releasing hormone (TRH) as a novel stimulant of epidermal regeneration. Moving to a complementary human ex vivo wounded skin assay, we demonstrate that the effects of TRH are conserved across the amphibian-mammalian divide: TRH stimulates wound closure and formation of neo-epidermis in organ-cultured human skin, accompanied by increased keratinocyte proliferation and wound healing-associated differentiation (cytokeratin 6 expression). Thus, TRH represents a novel, clinically relevant neuroendocrine wound repair promoter that deserves further exploration. These complementary frog and human skin ex vivo assays encourage a comparative biology approach in future wound healing research so as to facilitate the rapid identification and preclinical testing of novel, evolutionarily conserved, and clinically relevant wound healing promoters
Methods for specifying the target difference in a randomised controlled trial : the Difference ELicitation in TriAls (DELTA) systematic review
Peer reviewedPublisher PD
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