Peripheral visual cues contribute to the perception of object movement during self-movement

Safe movement through the environment requires us to monitor our surroundings for moving objects or people. However, identification of moving objects in the scene is complicated by self-movement, which adds motion across the retina. To identify worldrelative object movement the brain thus has to “compensate for” or “parse out” the components of retinal motion that are due to self-movement. We have previously demonstrated that retinal cues arising from central vision contribute to solving this problem. Here we investigate the contribution of peripheral vision, commonly thought to provide strong cues to self-movement. Stationary participants viewed a large field of view display, with radial flow patterns presented in the periphery, and judged the trajectory of a centrally presented probe. Across two experiments, we demonstrate andquantify the contribution of peripheral optic flow to flow parsing during forward and backward movement

Observation of playa salts as nuclei in orographic wave clouds

During the Ice in Clouds Experiment-Layer Clouds (ICE-L), dry lakebed, or playa, salts from the Great Basin region of the United States were observed as cloud nuclei in orographic wave clouds over Wyoming. Using a counterflow virtual impactor in series with a single-particle mass spectrometer, sodium-potassium-magnesium-calcium-chloride salts were identified as residues of cloud droplets. Importantly, these salts produced similar mass spectral signatures to playa salts with elevated cloud condensation nuclei (CCN) efficiencies close to sea salt. Using a suite of chemical characterization instrumentation, the playa salts were observed to be internally mixed with oxidized organics, presumably produced by cloud processing, as well as carbonate. These salt particles were enriched as residues of large droplets (>19 μm) compared to smaller droplets (>7 μm). In addition, a small fraction of silicate-containing playa salts were hypothesized to be important in the observed heterogeneous ice nucleation processes. While the high CCN activity of sea salt has been demonstrated to play an important role in cloud formation in marine environments, this study provides direct evidence of the importance of playa salts in cloud formation in continental North America has not been shown previously. Studies are needed to model and quantify the impact of playas on climate globally, particularly because of the abundance of playas and expected increases in the frequency and intensity of dust storms in the future due to climate and land use changes

Culturally Relevant Practices and Community: Increasing Minority Leadership in School Administration to Improve School Climate

This dissertation and research looks into the area of Culturally Relevant Practices and Leadership in K-12 schools and the potential effect on all students in having minority leadership present. The research dives into interviews of teachers, hiring leaders, district leaders and building leaders. It also uses survey results from over 700 students, with the central theme of the questions around school safety, climate, culture, support, academics and a sense of belonging. The research purpose was to look into the potential positive effect on students and staff, if Culturally Relevant Practices and hiring of minority leadership was in place within school districts, classrooms and buildings

Response of neural reward regions to food cues in autism spectrum disorders

BACKGROUND: One hypothesis for the social deficits that characterize autism spectrum disorders (ASD) is diminished neural reward response to social interaction and attachment. Prior research using established monetary reward paradigms as a test of non-social reward to compare with social reward may involve confounds in the ability of individuals with ASD to utilize symbolic representation of money and the abstraction required to interpret monetary gains. Thus, a useful addition to our understanding of neural reward circuitry in ASD includes a characterization of the neural response to primary rewards. METHOD: We asked 17 children with ASD and 18 children without ASD to abstain from eating for at least four hours before an MRI scan in which they viewed images of high-calorie foods. We assessed the neural reward network for increases in the blood oxygenation level dependent (BOLD) signal in response to the food images RESULTS: We found very similar patterns of increased BOLD signal to these images in the two groups; both groups showed increased BOLD signal in the bilateral amygdala, as well as in the nucleus accumbens, orbitofrontal cortex, and insula. Direct group comparisons revealed that the ASD group showed a stronger response to food cues in bilateral insula along the anterior-posterior gradient and in the anterior cingulate cortex than the control group, whereas there were no neural reward regions that showed higher activation for controls than for ASD. CONCLUSION: These results suggest that neural response to primary rewards is not diminished but in fact shows an aberrant enhancement in children with ASD

The role of peripheral vision in flow parsing

Identifying moving objects while we are moving is an important everyday skill. This ability allows us to monitor our surroundings, successfully interact with objects or people, and avoid potential hazards. Self-movement generates optical flow on the retina that complicates the recognition of moving objects from retinal motion alone. Rushton and Warren (2005) proposed a purely visual solution to this problem. They suggest that, in order to assess scene-relative object movement, the brain identifies and parses out (globally subtracts) patterns of visual flow that are consistent with self-movement. Existing research has demonstrated evidence of this flow parsing process in central vision (i.e. Warren & Rushton, 2008). This thesis aims to characterise the role of peripheral visual flow in this process. Research from the wider self-motion literature has often distinguished between central and peripheral vision. Some researchers have claimed that peripheral vision is specialised for self-motion perception, whilst more recent studies have challenged this assertion. This thesis investigates whether peripheral visual motion, traditionally considered to be a strong cue to self-movement, also contributes to flow parsing. The experimental work employed a simulated self-movement paradigm to isolate retinal motion from other non-visual cues. Thus, observers remained stationary whilst computer generated stimuli moved to produce patterns of retinal motion associated with actual self-movement. In the first set of experiments, I demonstrate that peripheral flow simulating forward or backward self-movement gives rise to characteristic flow parsing effects. This finding generalises to rotational observer motion (Chapter 3). Chapter 4 considers whether peripheral flow contributes to parsing for judgements of object size change. Finally, Chapter 5 investigates whether there is a benefit of peripheral information under conditions where central flow is potentially ambiguous. The results indicate that peripheral visual flow contributes to the flow parsing process. The contribution of flow in the near periphery appears to be maximally important

State Legislative Update

Senate Bill 1970 was introduced in the Florida Senate on March 2, 2004. It was initially referred to the Senate Judiciary Committee where it passed on April 19 with an 8-0 vote. Senate Bill 1970 was read for the first time in the Senate on April 21. The bill passed the full Senate on April 24 with a 39-0 vote. It was then sent to the full House on April 26 where it was substituted for House Bill 1765. Senate Bill 1970 was read and passed in the House on April 27 with a 114-0 vote. The bill was presented to Govenor Bush for signature on June 9 and signed into law on June 10, 2004

Understanding the Relationship between Substrate Cover and Seedling Abundance of the Santa Rosa Torrey Pine (Pinus torreyana var insularis)

The Santa Rosa Island Torrey pine (Pinus torreyana var insularis) is the rarest endemic pine species on the North American continent (Hall and Brinkman 2013). These pines exists within four stands on Santa Rosa Island (North, Cogan, Main, and Box), which is located 42 km off the coast of southern California. Over the past 150 years, much of the native vegetation on Santa Rosa Island (SRI) was heavily degraded by non-native grazing ungulates. These grazers were eradicated in 2011, prompting a unique opportunity to document vegetation regrowth patterns in the SRI Torrey Pine stands. My research was conducted jointly with the 2018/19 SRI Torrey Pines Demography Survey. Following the first survey in 2014, this survey is completed every 4 years to monitor regrowth within the groves. In order to better understand the reproductive health of SRI Torrey Pines, I compared seedling abundance within the groves from 2014 to 2018. Because the first demography survey documented substrate and soil, My research serves to establish baseline datasets for seedling height and substrate categorized by ranks. I hypothesized that if a grove is composed mainly of leaf litter and woody canopy, then it will support the highest abundance of seedlings