Even prey that successfully evade attack incur costs when responding to predators. These nonlethal costs can impact their reproductive success and survival. One strategy that prey can use to minimize these costs is to adjust their antipredator behavior based on the perceived level of risk. We tested whether humans adopt this strategy by presenting participants with photographic arrays of predators (lions) that varied in their level of risk. While their eye movements were recorded, the participants searched for a forward-facing predator (signifying potential predator interest; high-risk target) among an array of inattentive predators that were facing away (low-risk distractors) or searched for a predator that was facing away from them among an array of forward-facing predators. As a control, participants also searched through similar arrays that displayed a potential prey species (impalas) rather than predators. Participants detected forward-facing predators more quickly than predators facing away from them. Unexpectedly, they were also quicker at detecting forward-facing prey versus prey facing away from them, but slower to detect these forward-facing prey compared with forward-facing predators. They were slower to detect predators and prey facing away from them because they spent more time looking at the forward-facing distractors and looked at more of those distractors. The results indicate that human attention is drawn toward dangerous predators with forward-facing orientations, and this could allow humans to quickly assess predator intentions. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

No abstract

The Hylesia genus comprises a group of Neotropical moths ubiquitous in the Americas from Arizona to Argentina. One of the species of the Hylesia genus in Venezuela, French Guyana, and Trinidad has been identified as Hylesia metabus (Cramer 1775) (Lepidoptera: Saturniidae). In Venezuela, these moths are found in abundance in the mangrove (Avicennia spp.) swamps surrounding the Gulf of Paria and the Orinoco Delta in the eastern part of the country. During the mating season, the female adults shed copious amounts of urticating setae in the air, producing a severe papulovesicular dermatitis among the population in the affected areas. The females also use their urticating setae to protect the eggs during the hatching period. In the current study, we have isolated and partially characterized proteins with proinflammatory properties from the urticating setae in the egg-nests by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and anionic exchange-high-performance liquid chromatography (HPLC). We also have studied the biological response of the egg-nest extract and the HPLC purified fractions by inoculation in guinea pigs; and, analyzing the tissue samples by means of histopathological methods. The results of this study show that the extracted venom and HPLC purified subcomponents give rise to an intense inflammatory reaction characterized by massive infiltration of inflammatory cells, echymoses, and vascular degeneration. Chromatographic separation showed that the venom was made up of proteins having selectively vasodegenerative-fibrinolytic or proinflammatory-quimotactic properties.

The effect of subculture cycles on somaclonal variation of V. planifolia using intersimple sequence repeat (ISSR) markers was analyzed. Nodal segments of 2 cm in length were established in vitro and multiplied by 10 subculture cycles in Murashige and Skoog (MS) medium supplemented with 8.86 lM BAP (benzylaminopurine). After 45 days in each culture, the length and number of shoots per explant were evaluated. For ISSR markers, ten shoots per each subculture and the mother plant were used. Ten ISSR primers were used and a total of 118 bands were obtained. The polymorphism (%) was calculated and a dendrogram based on Jaccard's genetic distance between the subcultures and the donor plant was obtained. These results show that the multiplication rate tends to increase until subculture five, whereas shoot length decreases as the number of subcultures increases. The ISSR markers revealed an increase in the polymorphism percentage after the fifth culture cycle. The dendrogram showed the formation of two groups. The first group, with less genetic variability, is the donor plant and subcultures 1-5; the second group has greater genetic distance and is formed by subcultures 6-10. The results revealed that the number of subcultures with 8.86 lM BAP is a factor that affects the somaclonal variation during in vitro regeneration of V. planifolia. In conclusion, the subculture number affects somaclonal variation and in vitro development of V. planifolia.

The Hylesia genus comprises a group of Neotropical moths ubiquitous in the Americas from Arizona to Argentina. One of the species of the Hylesia genus in Venezuela, French Guyana, and Trinidad has been identified as Hylesia metabus (Cramer 1775) (Lepidoptera: Saturniidae). In Venezuela, these moths are found in abundance in the mangrove (Avicennia spp.) swamps surrounding the Gulf of Paria and the Orinoco Delta in the eastern part of the country. During the mating season, the female adults shed copious amounts of urticating setae in the air, producing a severe papulovesicular dermatitis among the population in the affected areas. The females also use their urticating setae to protect the eggs during the hatching period. In the current study, we have isolated and partially characterized proteins with proinflammatory properties from the urticating setae in the egg-nests by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and anionic exchange-high-performance liquid chromatography (HPLC). We also have studied the biological response of the egg-nest extract and the HPLC purified fractions by inoculation in guinea pigs; and, analyzing the tissue samples by means of histopathological methods. The results of this study show that the extracted venom and HPLC purified subcomponents give rise to an intense inflammatory reaction characterized by massive infiltration of inflammatory cells, echymoses, and vascular degeneration. Chromatographic separation showed that the venom was made up of proteins having selectively vasodegenerative-fibrinolytic or proinflammatory-quimotactic properties.