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Large ground-dwelling Neotropical gamebirds are highly threatened by habitat loss and hunting, but conservationists rarely attempt to distinguish between these two threats in the management of populations. We used three different types of species records to determine the status (i.e. persistence level) of the Endangered red-billed curassow Crax blumenbachii in 14 forest remnants in north-east Brazil, as either persistent, precarious or extirpated. We related these persistence levels to variables measured in a 2-km buffer radius, including variables associated with habitat quality (proportion of forest cover, length of rivers, patch density, distance from rivers) and hunting pressure (proportion of cacao agroforests and farmlands, length of roads, total area occupied by settlements, distance from roads and from settlements). Curassows were more persistent in forest patches located (1) more distant from settlements, (2) in landscapes with few settlements, (3) in landscapes with a high incidence of roads, (4) in a mosaic with a high proportion of forest, shaded cacao agroforest and farmland, and (5) more distant from other forest patches. Hunting pressure potentially exerts more influence on persistence than habitat quality: (1) hunting pressure submodels had a higher explanatory power than habitat quality submodels, (2) final models comprised four hunting pressure variables but only two habitat quality variables, and (3) hunting pressure variables appeared in all models whereas habitat quality variables appeared in only one final model. If hunting pressure is driving declines in curassows, regions with low human presence and a high proportion of forest cover are recommended for establishing new reserves.
Criminal groups often avoid the limelight, shunning publicity. However, in some instances, they overtly communicate, such as with banners or signs. This article explains the competition dynamics behind public criminal communication and provides theory and evidence of the conditions under which it emerges. Relying on a new dataset of approximately 1,800 banners publicly deployed by Mexican criminal groups from 2007 to 2010, the study identifies the conditions behind such messaging. The findings suggest that criminal groups “go public” in the presence of interorganizational contestation, violence from authorities, antagonism toward the local media, local demand for drugs, and local drug production. Some of these factors are associated only with communication toward particular audiences: rivals, the state, or the public. An interesting finding is that the correlates of criminal propaganda are sometimes distinct from those of criminal violence, suggesting that these phenomena are explained by separate dynamics.
The Chilean species traditionally assigned to the genera Chlamys Röding, 1798 or Zygochlamys Ihering, 1907 are now placed in two new endemic South American taxa: Dietotenhosen n. gen. (middle Miocene–early middle Pliocene), to include the southeastern Pacific Ocean species D. hupeanus (Philippi, 1887) n. comb. and D. remondi (Philippi, 1887) n. comb., and Ckaraosippur n. gen. (earliest middle Miocene–Pliocene), for C. calderensis (Möricke, 1896) n. comb. (Chile) and C. camachoi n. sp. (Argentina). Both genera are the youngest survivors of the tribe Chlamydini in southern South America. None of them is related to the circumpolar genus Psychrochlamys Jonkers, 2003, and the previous proposal of the dispersal through the Antarctic Circumpolar Current for the species included herein in Dietotenhosen is rejected.
We present a model for capillary-scale objects that bounce on a fluid bath as they also translate horizontally. The rebounding objects are hydrophobic spheres that impact the interface of a bath of incompressible fluid whose motion is described by linearised quasi-potential flow. Under a quasi-normal impact assumption, we demonstrate that the problem can be decomposed into an axisymmetric impact onto a quiescent bath surface, and the unforced evolution of the surface waves. We obtain a walking model that is free of impact parametrisation and we apply this formulation to model droplets walking on a vibrating bath. We show that this model accurately reproduces experimental reports of bouncing modes, impact phases and time-dependent wave field topography for bouncing and walking droplets. Moreover, we revisit the modelling of horizontal drag during droplet impacts to incorporate the effects of the changes in the pressed area during droplet–surface contacts. Finally, we show that this model captures the recently discovered phenomenon of superwalkers.
There is a long history of exploitation of the South American river turtle Podocnemis expansa. Conservation efforts for this species started in the 1960s but best practices were not established, and population trends and the number of nesting females protected remained unknown. In 2014 we formed a working group to discuss conservation strategies and to compile population data across the species’ range. We analysed the spatial pattern of its abundance in relation to human and natural factors using multiple regression analyses. We found that > 85 conservation programmes are protecting 147,000 nesting females, primarily in Brazil. The top six sites harbour > 100,000 females and should be prioritized for conservation action. Abundance declines with latitude and we found no evidence of human pressure on current turtle abundance patterns. It is presently not possible to estimate the global population trend because the species is not monitored continuously across the Amazon basin. The number of females is increasing at some localities and decreasing at others. However, the current size of the protected population is well below the historical population size estimated from past levels of human consumption, which demonstrates the need for concerted global conservation action. The data and management recommendations compiled here provide the basis for a regional monitoring programme among South American countries.
We investigated the distribution of comorbidities among adult tuberculosis (TB) patients in Chiapas, the poorest Mexican state, with a high presence of indigenous population, and a corridor for migrants from Latin America. Secondary analysis on 5508 new adult TB patients diagnosed between 2010 and 2014 revealed that the most prevalent comorbidities were diabetes mellitus (DM; 19.1%) and undernutrition (14.4%). The prevalence of DM in these TB patients was significantly higher among middle aged (41–64 years) compared with older adults (⩾65 years) (38.6% vs. 23.2%; P < 0.0001). The prevalence of undernutrition was lower among those with DM, and higher in communities with high indigenous presence. Immigrants only comprised 2% of all TB cases, but were more likely to have unfavourable TB treatment outcomes (treatment failure, death and default) when compared with those born in Chiapas (29.5% vs. 11.1%; P < 0.05). Unfavourable TB outcomes were also more prevalent among the TB patients with undernutrition, HIV or older age, but not DM (P < 0.05). Our study in Chiapas illustrates the challenges of other regions worldwide where social (e.g. indigenous origin, poverty, migration) and host factors (DM, undernutrition, HIV, older age) are associated with TB. Further understanding of these critical factors will guide local policy makers and health providers to improve TB management.
This work combines very detailed measurements from terrestrial laser scanner (TLS), ground-based interferometry radar (GB-SAR) and ground-penetrating radar (GPR) to diagnose current conditions and to analyse the recent evolution of the Monte Perdido Glacier in the Spanish Pyrenees from 2011 to 2017. Thus, this is currently one of the best monitored small glacier (<0.5 km2) worldwide. The evolution of the glacier surface was surveyed with a TLS evidencing an important decline of 6.1 ± 0.3 m on average, with ice losses mainly concentrated over 3 years (2012, 2015 and 2017). Ice loss is unevenly distributed throughout the study period, with 10–15 m thinning in some areas while unchanged areas in others. GB-SAR revealed that areas with higher ice losses are those that are currently with no or very low ice motion. In contrast, sectors located beneath the areas with less ice loss are those that still exhibit noticeable ice movement (average 2–4.5 cm d─1 in summer, and annual movement of 9.98 ma─1 from ablation stakes data). GPR informed that ice thickness was generally <30 m, though locally 30–50 m. Glacier thinning is still accelerating and will lead to extinction of the glacier over the next 50 years.
Zygochlamys Ihering, 1907 is revised and three new genera of tribe Chlamydini are named: the monospecific early Miocene genera Pixiechlamys new genus (type species: Pecten quemadensis Ihering, 1897) and Chokekenia n. gen. (type species: Zygochlamys nicolasi Morra, 1985), and the late Miocene–early Pliocene Moirechlamys n. gen., containing Pecten actinodes Sowerby, 1846 (type species) and Chlamys aurorae Feruglio, 1954. Zygochlamys is restricted to include Z. geminata (Sowerby, 1846) (type species), Z. jorgensis Ihering, 1907, and Z. sebastiani Morra, 1985. The present analysis increases the biostratigraphic usefulness of the group and improves taxonomic knowledge of the Neogene molluscan assemblages defined previously for Patagonia. Zygochlamys geminata is confined to the latest Oligocene–early Miocene interval of the Austral Basin of Patagonia (Argentina) and to the early Miocene of Chile, Z. jorgensis is restricted to the early to middle Miocene of the Golfo San Jorge and northern Austral Basins, and Moirechlamys n. gen., the most widespread genus, occurs in the late Miocene–early Pliocene of the Austral, Golfo San Jorge, Valdés, and Colorado basins. All these genera are endemic to southern South America; Zygochlamys is not related to other circumpolar genera such as Austrochlamys Jonkers, 2003 or Psychrochlamys Jonkers, 2003, rejecting its dispersal in the Antarctic Circumpolar Current, as has been proposed previously.
Androgens have been shown to exert a cysticidal effect upon Taenia crassiceps, an experimental model of cysticercosis. To further inquire into this matter, the Taenia crassiceps model was used to evaluate the expression of several proteins after testosterone (T4) and dihydrotestosterone (DHT) in vitro treatment. Under 2-D proteomic maps, parasite extracts were resolved into approximately 130 proteins distributed in a molecular weight range of 10–250 kDa and isoelectrical point range of 3–10. The resultant proteomic pattern was analysed, and significant changes were observed in response to T4 and DHT. Based on our experience with electrophoretic patterns and proteomic maps of cytoskeletal proteins, alteration in the expression of isoforms of actin, tubulin and paramyosin and of other proteins was assessed. Considering that androgens may exert their biological activity in taeniids through the non-specific progesterone receptor membrane component (PGRMC), we harnessed bioinformatics to propose the identity of androgen-regulated proteins and establish their hypothetical physiological role in the parasites. These analyses yield a possible explanation of how androgens exert their cysticidal effects through changes in the expression of proteins involved in cytoskeletal rearrangement, dynamic vesicular traffic and transduction of intracellular signals.
Organic compounds such as azo dyes have been detected in wastewater due to their use in industries without regulation. Conventional wastewater treatments are not always effective in the removal of these pollutants. Among the innovative materials that deal with this problem, are the polymer-zeolitic composites used as adsorbents. Modified natural zeolites have been proven to be efficient for the removal of yellow 6; on the other hand, biopolymers such as alginate offer their potential use as a polymer matrix for the synthesis of biocomposites. In this study, the adsorbent properties of a ferric zeolite and an alginate-ferric zeolite composite were determined for the removal of yellow 6 dye from aqueous solutions. The X-ray diffraction (XRD) results of both natural and modified zeolites indicated the presence of clinoptilolite. The characteristic bands of these materials were identified through the Fourier Transform Infrared Spectroscopy (FTIR) technique. Moreover, the presence of iron in the ferrous zeolite was verified by elemental analysis (EDS). Adsorption tests showed that the composite has a lower removal capacity than the zeolitic material; however, in the case of water treatment systems, the composite would be easier to handle than the zeolite without supporting it in a polymer matrix.
In this essay, we discuss the under-representation of women in leadership positions in global health (GH) and the importance of mentorship to advance women's standing in the field. We then describe the mentorship model of GROW, Global Research for Women. We describe the theoretical origins of the model and an adapted theory of change explaining how the GROW model for mentorship advances women's careers in GH. We present testimonials from a range of mentees who participated in a pilot of the GROW model since 2015. These mentees describe the capability-enhancing benefits of their mentorship experience with GROW. Thus, preliminary findings suggest that the GROW mentorship model is a promising strategy to build women's leadership in GH. We discuss supplemental strategies under consideration and next steps to assess the impact of GROW, providing the evidence to inform best practices for curricula elsewhere to build women's leadership in GH.
The first systematic analysis of the Danian carditids of Patagonia is presented, which includes four genera—one new genus and the first records of three other genera in South America. They consist of Claibornicardia paleopatagonica (Ihering, 1903), a widely distributed species occuring in the Jagüel, Roca and Salamanca formations (Neuquén, Río Negro and Chubut Provinces); Rotundicardia Heaslip, 1968, represented by the new species R. mariobrosorum n. sp., which is restricted to the Roca Formation (Río Negro Province); Cardites feruglioi (Petersen, 1846) (Roca and Lefipán formations, Río Negro and Chubut Provinces); and by Kalelia new genus, which includes K. burmeisteri (Böhm, 1903) from the Salamanca and Roca formations (Río Negro and Chubut Provinces), which is related to the Paris Basin species K. multicostata (Lamarck, 1806) n. comb. and K. pectuncularis (Lamarck, 1806) n. comb. ‘Venericardia’ iheringi (Böhm, 1903), a species known only from internal molds, is described and regarded as a carditid with uncertain affinities. The presence of Claibornicardia, Rotundicardia, and Cardites in Patagonia constitutes the most ancient record of these genera and confirms biogeographical connections previously established between the Danian Argentinian and North American/European fossil faunas.
We present a fully predictive model for the impact of a smooth, convex and perfectly hydrophobic solid onto the free surface of an incompressible fluid bath of infinite depth in a regime where surface tension is important. During impact, we impose natural kinematic constraints along the portion of the fluid interface that is pressed by the solid. This provides a mechanism for the generation of linear surface waves and simultaneously yields the pressure applied on the impacting masses. The model compares remarkably well with data of the impact of spheres and bouncing droplet experiments, and is completely free of any of impact parametrisation.