Extraction of flood-modelling related base-data from multisource remote sensing imagery

Flooding is one of the most destructive natural hazards, accounting for over a third of all disaster damage worldwide. In particular in less developed countries (LDCs) this is typically attributed to poor planning, lack of warning systems and limited awareness of the hazard. A number of flood risk models have been developed, but have as yet contributed little to mapping and quantifying the risk in LDCs, for several reasons. In addition to limited human and technical capacity, these models require considerable amounts of current spatial information that is widely lacking, such as landcover, elevation and elements at risk basedata. Collecting those with ground-based methods is difficult, but remote sensing technologies have the potential to acquire them economically. To account for the variety of required information, data from different sensors are needed, some of which may not be available or affordable. Therefore, data interchangeability needs to be considered. Thus we test the potential of high spatial resolution optical imagery and laser scanning data to provide the information required to run such flood risk models as SOBEK. Using segmentation-based analysis in eCognition, Quickbird and laser scanning data were used to extract building footprints as well as the boundaries of informal settlements. Additionally, a landcover map to provide roughness values for the model was derived from the Quickbird image. These basedata were used in model simulations to assess their actual utility, as well as the sensitivity of the model to variations in basedata quality. The project shows that existing remote sensing data and image analysis methods can match the input requirements for flood models, and that, given the unavailability of one dataset, alternative images can fill the gap.</p

Synthesis writing in science orientation classes:An instructional design study

This study tested an instructional design to improve students' synthesis performance in a specific academic subject, Science Orientation, which aimed to teach students how to critically evaluate scientific debates. The design included three components: 1) students construct a task definition via a learning strategy based on comparing and contrasting texts and processes, 2) students comprehend source information via a read-stop-think-note strategy, and 3) students connect source information critically via a semantic-textual transformation strategy. After several design iterations, the instructional design was tested in a quasi-experimental experiment with a pretest-posttest. Seven 10th grade classes participated in the intervention (n=129), four in the control condition (n=86). The design seemed feasible for teachers, students completed most learning tasks as intended and evaluated the course positively. Furthermore, texts written in the experimental condition at posttest were rated significantly higher than those written in the control condition on the instructed aspects: representation of source information, intertextual integration, and critical stance. This instructional design appears to have potential for helping students improve their comprehension of scientific debates and comprehensive writing. In the discussion we propose that the instructional design might be a general format for learning to synthesize domain specific information from contrasting sources.</p

A comparison of flash flood response at two different watersheds in Grenada, Caribbean Islands

Grenada is one of the susceptible areas to flooding. It is due to the high intensity of rainfall in each year and Grenada often hit by hurricanes and tropical storms. Flash-flood often occur in Grenada, specifically in two areas (Gouyave and St. John's watershed). Both of them have different characteristics. Gouyave watershed represents rural area, whereas St. John's watershed is an urban area. This paper aims to understand the flash-flood response of Gouyave and St. John's watershed in different return periods. It is emphasized that urbanization is an important factor related to flash-flood. This paper uses quantitative methods with flood modelling using OpenLISEM software. Input data to develop flood modelling are DEM (Digital Elevation Model), saturated hydraulic conductivity (Ksat), initial soil moisture, surface roughness (Manning's n), and random roughness. The result shows that St. John's watershed is more sensitive and has higher response to flash-flood than Gouyave. St. John's watershed is more urbanized which decreases water infiltration. So, it increases the potential run-off and flash-flood events become more massive

Corollary discharge promotes a sustained motor state in a neural circuit for navigation

Animals exhibit behavioral and neural responses that persist on longer timescales than transient or fluctuating stimulus inputs. Here, we report that Caenorhabditis elegans uses feedback from the motor circuit to a sensory processing interneuron to sustain its motor state during thermotactic navigation. By imaging circuit activity in behaving animals, we show that a principal postsynaptic partner of the AFD thermosensory neuron, the AIY interneuron, encodes both temperature and motor state information. By optogenetic and genetic manipulation of this circuit, we demonstrate that the motor state representation in AIY is a corollary discharge signal. RIM, an interneuron that is connected with premotor interneurons, is required for this corollary discharge. Ablation of RIM eliminates the motor representation in AIY, allows thermosensory representations to reach downstream premotor interneurons, and reduces the animal\u27s ability to sustain forward movements during thermotaxis. We propose that feedback from the motor circuit to the sensory processing circuit underlies a positive feedback mechanism to generate persistent neural activity and sustained behavioral patterns in a sensorimotor transformation

Co-option of neurotransmitter signaling for inter-organismal communication in C. elegans

Biogenic amine neurotransmitters play a central role in metazoan biology, and both their chemical structures and cognate receptors are evolutionarily conserved. Their primary roles are in cell-to-cell signaling, as biogenic amines are not normally recruited for communication between separate individuals. Here, we show that in the nematode C. elegans, a neurotransmitter-sensing G protein-coupled receptor, TYRA-2, is required for avoidance responses to osas#9, an ascaroside pheromone that incorporates the neurotransmitter, octopamine. Neuronal ablation, cell-specific genetic rescue, and calcium imaging show that tyra-2 expression in the nociceptive neuron, ASH, is necessary and sufficient to induce osas#9 avoidance. Ectopic expression in the AWA neuron, which is generally associated with attractive responses, reverses the response to osas#9, resulting in attraction instead of avoidance behavior, confirming that TYRA-2 partakes in the sensing of osas#9. The TYRA-2/osas#9 signaling system represents an inter-organismal communication channel that evolved via co-option of a neurotransmitter and its cognate receptor

Estimating the Under-Five Mortality Rate Using a Bayesian Hierarchical Time Series Model

Background: Millennium Development Goal 4 calls for a reduction in the under-five mortality rate by two-thirds between 1990 and 2015, which corresponds to an annual rate of decline of 4.4%. The United Nations Inter-Agency Group for Child Mortality Estimation estimates under-five mortality in every country to measure progress. For the majority of countries, the estimates within a country are based on the assumption of a piece-wise constant rate of decline. Methods and Findings: This paper proposes an alternative method to estimate under-five mortality, such that the underlying rate of change is allowed to vary smoothly over time using a time series model. Information about the average rate of decline and changes therein is exchanged between countries using a Bayesian hierarchical model. Cross-validation exercises suggest that the proposed model provides credible bounds for the under-five mortality rate that are reasonably well calibrated during the observation period. The alternative estimates suggest smoother trends in under-five mortality and give new insights into changes in the rate of decline within countries. Conclusions: The proposed model offers an alternative modeling approach for obtaining estimates of under-five mortality which removes the restriction of a piece-wise linear rate of decline and introduces hierarchy to exchange information between countries. The newly proposed estimates of the rate of decline in under-5 mortality and the uncertaint

RegPredict: an integrated system for regulon inference in prokaryotes by comparative genomics approach

RegPredict web server is designed to provide comparative genomics tools for reconstruction and analysis of microbial regulons using comparative genomics approach. The server allows the user to rapidly generate reference sets of regulons and regulatory motif profiles in a group of prokaryotic genomes. The new concept of a cluster of co-regulated orthologous operons allows the user to distribute the analysis of large regulons and to perform the comparative analysis of multiple clusters independently. Two major workflows currently implemented in RegPredict are: (i) regulon reconstruction for a known regulatory motif and (ii) ab initio inference of a novel regulon using several scenarios for the generation of starting gene sets. RegPredict provides a comprehensive collection of manually curated positional weight matrices of regulatory motifs. It is based on genomic sequences, ortholog and operon predictions from the MicrobesOnline. An interactive web interface of RegPredict integrates and presents diverse genomic and functional information about the candidate regulon members from several web resources. RegPredict is freely accessible at http://regpredict.lbl.gov