RESUMEN
Recently, the World Health Organization recognized that efforts to interrupt schistosomiasis transmission through mass drug administration have been ineffective in some regions; one of their new recommended strategies for global schistosomiasis control emphasizes targeting the freshwater snails that transmit schistosome parasites. We sought to identify robust indicators that would enable precision targeting of these snails. At the site of the world's largest recorded schistosomiasis epidemic-the Lower Senegal River Basin in Senegal-intensive sampling revealed positive relationships between intermediate host snails (abundance, density, and prevalence) and human urogenital schistosomiasis reinfection (prevalence and intensity in schoolchildren after drug administration). However, we also found that snail distributions were so patchy in space and time that obtaining useful data required effort that exceeds what is feasible in standard monitoring and control campaigns. Instead, we identified several environmental proxies that were more effective than snail variables for predicting human infection: the area covered by suitable snail habitat (i.e., floating, nonemergent vegetation), the percent cover by suitable snail habitat, and size of the water contact area. Unlike snail surveys, which require hundreds of person-hours per site to conduct, habitat coverage and site area can be quickly estimated with drone or satellite imagery. This, in turn, makes possible large-scale, high-resolution estimation of human urogenital schistosomiasis risk to support targeting of both mass drug administration and snail control efforts.
Asunto(s)
Bulinus , Vectores de Enfermedades , Ecosistema , Esquistosomiasis/transmisión , Animales , Humanos , Densidad de Población , Imágenes Satelitales , Esquistosomiasis/epidemiología , Senegal/epidemiología , Análisis EspacialRESUMEN
Across four experiments (N = 1,923), this research provides converging evidence of a talisman effect of insurance-consumers who have an insurance policy feel that the covered mishap is less likely to occur. Although such an effect has previously been proposed, empirical evidence for it is limited, in part because the talisman effect has often been conflated with a related but distinct magical-thinking phenomenon, the tempting-fate effect. By disentangling these two effects, we are better able to isolate the talisman effect and show that it is a robust phenomenon in its own right. We also provide support for a mechanism underlying the talisman effect: Insurance reduces anxiety and repetitious thoughts related to the mishap; with fewer thoughts about the mishap, its cognitive availability is lower and so it seems less likely to occur.
Asunto(s)
Ansiedad , Seguro , Humanos , Ansiedad/psicología , Magia , Pensamiento , CogniciónRESUMEN
The recovery of whale populations from centuries of exploitation will have important management and ecological implications due to greater exposure to anthropogenic activities and increasing prey consumption. Here, a Bayesian population model integrates catch data, estimates of abundance, and information on genetics and biology to assess the recovery of western South Atlantic (WSA) humpback whales (Megaptera novaeangliae). Modelling scenarios evaluated the sensitivity of model outputs resulting from the use of different data, different model assumptions and uncertainty in catch allocation and in accounting for whales killed but not landed. A long period of exploitation drove WSA humpback whales to the brink of extinction. They declined from nearly 27 000 (95% PI = 22 800-33 000) individuals in 1830 to only 450 (95% PI = 200-1400) whales in the mid-1950s. Protection led to a strong recovery and the current population is estimated to be at 93% (95% PI = 73-100%) of its pre-exploitation size. The recovery of WSA humpback whales may result in large removals of their primary prey, the Antarctic krill (Euphausia superba), and has the potential to modify the community structure in their feeding grounds. Continued monitoring is needed to understand how these whales will respond to modern threats and to climate-driven changes to their habitats.
RESUMEN
The South American gymnophthalmid genus Euspondylus is distributed from Venezuela through Peru, with its highest diversity occurring in Peru. Euspondylus paxcorpus sp. nov. is a new species from Junín, Peru possessing prefrontal scales and represented by 60 specimens. The new species differs from all other species by the combination of four supraoculars with supraocular/supraciliary fusion, 5-7 occipitals, a single palpebral scale, five supralabials and infralabials, quadrangular dorsal scales with low keels arranged in transverse series only, 40-45 in a longitudinal count and 22-28 in a transverse count, 12 rows of ventrals in a transverse count and 23-25 in a longitudinal count, and no sexual dimorphism in coloration. The discovery of E. paxcorpus increases the known number of Euspondylus species to 13. Because the coloration patterns of the specimens were greatly different after preservation in alcohol, caution should be used when identifying Euspondylus species from museum specimens.
Asunto(s)
Lagartos/anatomía & histología , Lagartos/clasificación , Animales , Femenino , Masculino , Perú , Pigmentación , Especificidad de la EspecieRESUMEN
Schroederichthys chilensis, the redspotted catshark or chilean catshark, is an endemic species to Peruvian and Chilean waters. Observations on its behavior in the National Reserve System of Guano Islands, Islets, and Capes - Punta San Juan and Paracas National Reserve reveal that it curls when threatened. This hypothesized survival strategy has not been previously documented in this species and we recommend further studies to elucidate this behavior.
Schroederichthys chilensis, tiburón gato o tollo gato, es una especie endémica de las aguas peruanas y chilenas. Observaciones sobre su comportamiento en el medio natural de la Reserva Nacional Sistema de Islas, Islotes y Puntas Guaneras - Punta San Juan y Reserva Nacional de Paracas, revelan que se enroscan ante la presencia de peligro inminente. Esta estrategia de sobrevivencia no ha sido documentada para esta especie y se sugiere la realización de estudios que permitan conocer más sobre este comportamiento.