Investigation of Pressure and Pressure Gradients along the LA/TX Inner Shelf and their Relationships to Wind Forcing and Current Variability

Summary describing the work completed at Louisiana State University (Baton Rouge, La.). Coastal Studies Institute. for Pressure Gauge and Moored CTD Array along the Louisiana Coastal Current. It includes background information on the project funding and sponsorship, goals, methodology, and findings

High-Resolution Integrated Hydrology-Hydrodynamic Model: Development and Application to Barataria Basin, Louisiana

Report summary describing the work completed at Louisiana State University (Baton Rouge, La.) Coastal Studies Institute and Department of Oceanography & Coastal Sciences for 'Coastal Marine Environmental Modeling: Part III'. It includes background information on the project funding and sponsorship, goals, methodology, and findings

Mitigation Strategies of Reflection Cracking in Pavements

LTRC project Number: 14-4PFReflection cracking is a serious challenge associated with pavement rehabilitation. Practical experience shows that reflection cracking propagates at a rate of 1 in. per year. The primary objective of this synthesis study is to conduct an in-depth literature review of research projects on reflection cracking and a survey of the practices of highway agencies with regard to the types of cracking mitigation strategy used. Based on the results of the literature review and the survey questionnaire, a summarized assessment is presented for each reviewed treatment method. Further, a number of treatment methods were identified for further evaluation. For existing hot mix asphalt (HMA) pavements, crack sealing and overlay, chip seal and open-graded interlayers, full-depth reclamation, and cold-in place recycling are the most promising treatment methods. For existing Portland cement concrete (PCC) pavements, saw and seal, chip seal and open-graded interlayer systems, and rubblization are the most promising treatment methods. Based on the results of this study, the research team recommends that a follow-up study be conducted in order to evaluate the cost-effectiveness of the most promising treatment methods and to develop guidelines for the control of reflection cracking. The developed crack control guidelines will present recommended treatment methods for different classes of rehabilitated pavements in order to achieve adequate control of reflection cracking in a cost effective manner

The impact of low erythrocyte density in human blood on the fitness and energetic reserves of the African malaria vector Anopheles gambiae

Background Anaemia is a common health problem in the developing world. This condition is characterized by a reduction in erythrocyte density, primarily from malnutrition and/or infectious diseases such as malaria. As red blood cells are the primary source of protein for haematophagous mosquitoes, any reduction could impede the ability of mosquito vectors to transmit malaria by influencing their fitness or that of the parasites they transmit. The aim of this study was to determine the impact of differences in the density of red blood cells in human blood on malaria vector (Anopheles gambiae sensu stricto) fitness. The hypotheses tested are that mosquito vector energetic reserves and fitness are negatively influenced by reductions in the red cell density of host human blood meals commensurate with those expected from severe anaemia. Methods Mosquitoes (An. gambiae s.s.) were offered blood meals of different packed cell volume(PCV) of human blood consistent with those arising from severe anaemia (15%) and normalPCV (50%). Associations between mosquito energetic reserves (lipid, glucose and glycogen)and fitness measures (reproduction and survival) and blood meal PCV were investigated. Results The amount of protein that malaria vectors acquired from blood feeding (indexed by haematin excretion) was significantly reduced at low blood PCV. However, mosquitoes feeding on blood of low PCV had the same oviposition rates as those feeding on blood of normal PCV, and showed an increase in egg production of around 15%. The long-term survival of An. gambiae s.s was reduced after feeding on low PCV blood, but PCV had no significant impact on the proportion of mosquitoes surviving through the minimal period required to develop and transmit malaria parasites (estimated as 14 days post-blood feeding). The impact of blood PCV on the energetic reserves of mosquitoes was relatively minor. Conclusions These results suggest that feeding on human hosts whose PCV has been depleted due to severe anaemia does not significantly reduce the fitness or transmission potential of malaria vectors, and indicates that mosquitoes may be able exploit resources for reproduction more efficiently from blood of low rather than normal PCV

Minimum Intersection Illumination

20-3SASIO No. DOTLT1000373Numerous prior studies indicated that street lighting improves nighttime traffic safety. However, lighting at unsignalized intersections (e.g., stop-controlled intersections and roundabouts) is not mandatory in some states such as Louisiana. This study aimed to examine whether Louisiana has traffic safety problems due to lack of lighting at its rural and suburban roundabouts and stop-controlled intersections. Underlying this goal, this study set out to (1) record the lessons learned from other states that had implemented partial or full lighting policies or other potentially low-cost countermeasures at their intersections; (2) explore whether the lighting at intersections has a significant impact on the behavior and safety of drivers; and (3) determine the viability of installing lighting at these types of intersections in Louisiana. To achieve these goals, four different approaches were employed: (1) crash data analysis, (2) online national survey among professionals working at the departments of transportation (DOTs) in the US, (3) driving simulator experiment, and (4) cost-benefit analysis

Development of Geopolymers Based Cement and Soil Stabilizers for Transportation Infrastructure

69A3551747106Geopolymer Cement (GPC) has drawn much attention in the recent years as an alternative to Ordinary Portland Cement (OPC) for soil stabilization, pavements, bridges and other transportation structures due to their good mechanical properties in comparison to OPC. In addition, GPC can be processed at room temperatures from aqueous solutions of waste materials (e.g. fly ash) or abundant natural sources (e.g. clay), thereby significantly reducing CO2 production associated with processing of OPC. As such, GPC proves to be a more sustainable and environmentally friendly alternative than OPC. This research explores methods to develop GPC with desired properties and evaluate their durability characteristics as part of their long-term performance based on real service conditions when exposed to significant water intake during flooding or torrential rainfall. Teams from Texas A&M University (TAMU) and University of Texas at Arlington (UTA) collaborated in this study to understand GPC, propose different methods to synthesize GPC, and to effectively synthesize a GPC composition

Development of Freeway Corridor Capacity Measure to Improve Transportation Resilience

69A3551747130Conventional methods to assess the quality of service on freeways are based on the comparison of a specific peak hour traffic demand to the capacity of the facility, which is usually measured at a single uniform bottleneck section. However, estimating the quality of service of one bottleneck section may not be sufficient to assess the performance of an entire freeway facility. A driver travelling along a freeway corridor may actually encounter multiple flow breakdowns at independent bottleneck sections, which affect the overall quality of service. This paper introduces a comprehensive approach that considers an entire freeway corridor as a system consisting of successive independent bottlenecks with different characteristics and can be used to estimate the optimum sustainable volume. The methodology is based on the Sustained Flow Index (SFI), which is defined as the product of traffic volume and the probability of survival at this volume. Optimum volumes of two real-world corridors are estimated based on the new derivations. The empirical results reveal that the optimum volume and the capacity of an entire corridor is less than those of its most restrictive bottleneck

An Epithelial Serine Protease, AgESP, Is Required for Plasmodium Invasion in the Mosquito Anopheles gambiae

Background: Plasmodium parasites need to cross the midgut and salivary gland epithelia to complete their life cycle in the mosquito. However, our understanding of the molecular mechanism and the mosquito genes that participate in this process is still very limited. Methodology/Principal Findings: We identified an Anopheles gambiae epithelial serine protease (AgESP) that is constitutively expressed in the submicrovillar region of mosquito midgut epithelial cells and in the basal side of the salivary glands that is critical for Plasmodium parasites to cross these two epithelial barriers. AgESP silencing greatly reduces Plasmodium berghei and Plasmodium falciparum midgut invasion and prevents the transcriptional activation of gelsolin, a key regulator of actin remodeling and a reported Plasmodium agonist. AgESP expression is highly induced in midgut cells invaded by Plasmodium, suggesting that this protease also participates in the apoptotic response to invasion. In salivary gland epithelial cells, AgESP is localized on the basal side–the surface with which sporozoites interact. AgESP expression in the salivary gland is also induced in response to P. berghei and P. falciparum sporozoite invasion, and AgESP silencing significantly reduces the number of sporozoites that invade this organ. Conclusion: Our findings indicate that AgESP is required for Plasmodium parasites to effectively traverse the midgut and salivary gland epithelial barriers. Plasmodium parasites need to modify the actin cytoskeleton of mosquito epithelial cells t