EFFECTS OF A VISUAL HORIZON ON DROSOPHILA MELANOGASTER OBJECT-TRACKING RESPONSES

To navigate effectively in three-dimensional space, flying insects must approximate distances to nearby objects. Humans are able to use an array of cues to guide depth perception in the visual world. However, some of these cues are not available to insects that are constrained by their rigid eyes and relatively small body size. Flying fruit flies can use motion parallax to gauge the distance of nearby objects, but using this cue becomes a less effective strategy as objects become more remote. Humans are able to infer depth across far distances by comparing the angular distance of an object to the horizon. This study tested if flying fruit flies, like humans, use the relative position of the horizon as a depth cue. Fruit flies in tethered flight were stimulated with a virtual environment that displayed vertical bars of varying elevation relative to a horizon, and their tracking responses were recorded. This study showed that tracking responses of the flies were strongly increased by reducing the apparent elevation of the bar against the horizon, indicating that fruit flies may be able to assess the distance of far off objects in the natural world by comparing them against a visual horizon.

Immigrant high school students' in-depth understandings of the value of heritage language and bilingualism

The purpose of this research was to explore perceptions among 9 th through 12th grade students from Brazil, Haiti and Jamaica, with respect to their heritage languages: Portuguese, Haitian Creole, and Jamaican Patois. An additional purpose was to understand in greater detail possible variations of perception with respect to heritage language maintenance (or loss) in relation to one’s gender, first language, and place of birth. The research implemented semi-structured interviews with male and female adolescents with these heritage language backgrounds. Participants’ responses were recorded and transcribed. The transcriptions were analyzed via a categorizing of themes emerging from the data. Data were analyzed using inductive analysis. Three categories emerged from the inductive analysis of the data: (a) heritage language, (b) bilingualism, and (c) English as a second language. The analysis reveals that as participants learn English, they continue to value their heritage language and feel positively toward bilingualism, but differ in their preference regarding use of native language and English in a variety of contexts. There seems to be a mismatch between a positive attitude and an interest in learning their heritage language. Families and teachers, as agents, may not be helping students fully understand the advantages of bilingualism. Students seem to have a lack of understanding of bilingualism’s cognitive and bi-literacy benefits. Instead, employment seems to be perceived as the number one reason for becoming bilingual. Also, the students have a desire to add culture to the heritage language curriculum. The study was conducted at one of the most diverse and largest high schools in Palm Beach, in Palm Beach County, Florida. The results of this study imply that given the positive attitude toward heritage language and bilingualism, students need to be guided in exploring their understanding of heritage language and bilingualism. Implications for teaching and learning, as well as recommendations for further research, are included.