University of Houston

About: University of Houston is a education organization based out in Houston, Texas, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 23074 authors who have published 53903 publications receiving 1641968 citations.

Hyperspectral and LiDAR Data Fusion: Outcome of the 2013 GRSS Data Fusion Contest

Abstract: The 2013 Data Fusion Contest organized by the Data Fusion Technical Committee (DFTC) of the IEEE Geoscience and Remote Sensing Society aimed at investigating the synergistic use of hyperspectral and Light Detection And Ranging (LiDAR) data. The data sets distributed to the participants during the Contest, a hyperspectral imagery and the corresponding LiDAR-derived digital surface model (DSM), were acquired by the NSF-funded Center for Airborne Laser Mapping over the University of Houston campus and its neighboring area in the summer of 2012. This paper highlights the two awarded research contributions, which investigated different approaches for the fusion of hyperspectral and LiDAR data, including a combined unsupervised and supervised classification scheme, and a graph-based method for the fusion of spectral, spatial, and elevation information.

Investigating grit and its relations with college students’ self-regulated learning and academic achievement

Abstract: We investigated grit and its relations with students’ self-regulated learning (SRL) and academic achievement. An ethnically diverse sample of 213 college students completed an online self-report survey that included the Grit Short scale (Duckworth and Quinn Journal of Personality Assessment, 91(2), 166–174, 2009), seven indicators of SRL and their past and present academic achievement. Results indicated that one aspect of grit, perseverance of effort, was a consistent and adaptive predictor for all indicators of SRL including value, self-efficacy, cognitive, metacognitive, motivational, time and study environment management strategies, and procrastination. A second aspect of grit, consistency of interest, was associated only with the latter two facets of SRL. Perseverance of effort predicted achievement before, but not after, accounting for SRL; hence, students’ engagement in SRL may serve as a mediating pathway through which this aspect of grit is associated with improved academic outcomes. In contrast, consistency of interest showed no relation to achievement. Implications of the findings for additional research and instruction are discussed.

Ultraviolet radiation and coral bleaching

Abstract: EPISODES of coral bleaching resulting from dissociation of endosymbiotic algae (zooxanthellae) from host coral tissues have occurred with increasing frequency over the past decade on reefs throughout the tropics1,2. These episodes have usually been attributed to increases in sea water temperatures3–10, but the mass bleaching events that occurred throughout the Caribbean during 1987 and 1990 were not readily explained by temperature alone11,12. An additional factor that may have contributed to these bleaching episodes is ultraviolet radiation in the 280–400-nm band. At many localities where bleaching occurred in 1987 and 1990, sea conditions were described as extremely calm with exceptionally clear water13. In the absence of suspended organic and inorganic matter in the water column, higher than average intensities of ultraviolet radiation probably reached all depths within the photic zone for several consecutive months. Evidence for a possible link between ultraviolet radiation and coral bleaching has not been forthcoming2. Here we report results of a field experiment showing that, irrespective of high water temperatures, short-term (three weeks) increases in ultraviolet radiation of a magnitude possible under calm, clear water column conditions can readily induce bleaching in reef-building corals.

Why Do Option Introductions Depress Stock Prices? A Study of Diminishing Short Sale Constraints

Abstract: Early studies find that option introductions tend to raise the price of underlying stocks. More recent research indicates that post-1980 option introductions are associated with negative abnormal returns in underlying stocks. Other studies document increased short sale activities following option listing. This paper provides evidence that the documented abnormal returns and changes in short interest around option listings are consistent with the mitigation of short sale constraints resulting from the option introduction, and that both the abnormal returns and short interest changes around listing dates can be predicted using ex ante characteristics of the underlying stock.

Planktonic larval duration of one hundred species of Pacific and Atlantic damselfishes (Pomacentridae)

Abstract: The plankton larval duration for 100 species of Pacific and Atlantic damselfishes was estimated from daily growth increments on the otolith of juvenile fish collected at various localities between July 1987 and September 1988. For newly-settled fishes, larval duration was determined by counting the entire number of increments present on the otolith, while for older juveniles estimates were made by counting the number of increments between the center of the otolith and a mark corresponding to settlement. We document the development of otolith formation during the period when eggs are incubated on the reef and show that daily increments are only accreted after larvae hatch and enter the planktonic phase. The planktonic larval duration for damselfish is shorter and less variable, both between and within species, compared to other groups of reef fishes such as wrasses and surgeonfishes. Larval duration ranged from 12 to 39 d. Average duration between species ranged from 13.1 to 35.2 d. The time spent in the plankton was not significantly correlated with geographic distribution when evaluated among species, however, genera with confined regional distribution have a shorter mean larval life than do widely distributed genera. Size at settlement was positively correlated with time spent in the plankton among species, but a significant correlation between these variables was only evident within one of ten species. The low variance in planktonic larval duration within species indicates that most damselfish are unable to delay metamorphosis following competency. This inability to postpone settlement limits the potential for dispersal, especially when dispersal time between suitable habitats is greater than about 30 d.