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Volume change behaviour of expansive clays has been one of the leading causes of damage to civil infrastructures worldwide. Contributing factors that lead to failures relate to changes in water content within the soil. Variations of water content can vary significantly based on an area’s climate regime. Trinidad has two seasons, the dry season (January to June) and the wet season (July to December). This variation leads to volume changes of expansive clay, where they exist mainly within the central and south regions of Trinidad. These areas are densely populated by residential and commercial buildings, which can be susceptible to damages from unsaturated expansive clays. The Soil Water Characteristic Curve (SWCC) for expansive clays is critical to estimate their unsaturated properties for the analysis of water flow movement. This study investigates the SWCCs for two expansive clay soil types in Trinidad. A WP4-T (Water Potential Measurement) is used to measure soil suction. The shrinkage curve (SC) test is conducted to consider the volume change of soil. The Fredlund and Xing (1994) SWCC equation and Fredlund and Zhang (2013) SC equation are used to fit the measured data. The SWCCs in terms of gravimetric and volumetric water contents and degree of saturation are compared. It is found that the normalised degree of saturation SWCC can provide a better display of the SWCC and estimation of the air-entry value.

The Thornthwaite Moisture Index (TMI) has been traditionally used as a climatic index parameter to estimate annual moisture status of soils (deficit/surplus), primarily in the agricultural domain. Engineers have also adopted the TMI in efforts to estimate volume change potential in expansive clays, where seasonal (temporal) moisture changes can be correlated to soil matric suction and ultimately volume change via appropriate mechanistic models. In Trinidad and Tobago, approximately 60 % of the islands are covered with over-consolidated clays of medium to high plasticity. When combined with extreme variations in moisture status, these plastic clays have exhibited high volume change potential. This paper investigates the spatial distribution of this climatic index for Trinidad and Tobago, intending to develop an index map for the islands. Within the post-colonial era in Trinidad and Tobago (1962 ~ present), the availability of consistent climatic data is limited to just two recording stations within the islands. The Meteorological Services of Trinidad and Tobago (MET) manages both stations: Piarco, Trinidad and Crown Point, Tobago, where consistent data exists for 36 years (1981 ~ 2018). These two points and their limited data timeframe cannot support the development of a spatial TMI map for the islands. This research addresses this shortcoming by collecting and analysing historical climatic data collected at 28 stations over Trinidad and Tobago over the British Colonial era (1931 ~ 1964). These data are recorded in publications of the Land Capability Surveys of The Imperial College of Tropical Agriculture (ICTA). Data sets of monthly rainfall data from the historical and at present for the Piarco location showed strong statistical coherence, examined through a t-test. Having justified the historical data, TMI values are calculated at all locations. Using the calculated TMI values, a map was developed using the GIS software, Surfer, and interpolation method of Kriging. In Trinidad, the map indicates high TMI at the north-eastern side of the island, with a significant decrease going into the south-western side. Low TMI values are observed in the most western side of Trinidad indicating substantially long dry season period, during which the underlying expansive clay can experience significant shrinkage.

Oil spills continue to generate various issues and concerns regarding their effect and behavior in the marine environment, owing to the related potential for detrimental environmental, economic and social implications. It is essential to have a solid understanding of the ways in which oil interacts with the water and the coastal ecosystems that are located nearby. This study proposes a simplified model for predicting the plume-like transport behavior of heavy Bunker C fuel oil discharging downward from an acutely-angled broken pipeline located on the water surface. The results show that the spill overall profile is articulated in three major flow areas. The first, is the source field, i.e., a region near the origin of the initial jet, followed by the intermediate or transport field, namely, the region where the jet oil flow transitions into an underwater oil plume flow and starts to move horizontally, and finally, the far-field, where the oil re-surface and spreads onto the shore at a significant distance from the spill site. The behavior of the oil in the intermediate field is investigated using a simplified injection-type oil spill model capable of mimicking the undersea trapping and lateral migration of an oil plume originating from a negatively buoyant jet spill. A rectangular domain with proper boundary conditions is used to implement the model. The Projection approach is used to discretize a modified version of the Navier-Stokes equations in two dimensions. A benchmark fluid flow issue is used to verify the model and the results indicate a reasonable relationship between specific gravity and depth as well as agreement with the aerial data and a vertical temperature profile plot.

Steel drums, or pans, play an important role in Trinidad's Carnival. Johnson examines the history of steelbands in the world and in relation to Carnival.

Expansive clays are the major cause of differential movements in shallow foundations. In highway pavements they are responsible for cyclic distortion of the riding surface resulting in a loss of road handling ability and service life of the pavement structure. Such distortion of the pavement surface is quantified in terms of its roughness. This work is primarily concerned with the prediction of such roughness based on climatic and soil conditions so that rational decisions may be made regarding the method that may be used in the control of such roughness. Of particular interest is the use of moisture barriers. This work is accomplished in three parts. In the first part, programs that quantify roughness in terms of three different parameters are developed and used to analyze the development of roughness at ten sites at which moisture barriers are installed in expansive clays. Roughness is interpreted through the analysis of relative elevation surface profiles recorded over a period of time of up to ten years. In the second phase, a parameter, which may be directly correlated to the development of roughness and which may be predicted through the analysis of climate and soil conditions, is developed. In the third and final phase, the rate of roughness development based on the three measures of roughness are related through regression to the soil and climatic parameter, the maximum expected vertical movement $\\Delta$H. The disciplines encountered are the analysis of roughness in traveled surfaces, the interpretation of climate, the modelling of unsaturated moisture movement and the modelling of soil deformation.

MicroRNA (miRNA) species (miR) regulate mRNA translation and are implicated as mediators of disease pathology via coordinated regulation of molecular effector pathways. Unraveling miR disease-related activities will facilitate future therapeutic interventions. miR-155 recently has been identified with critical immune regulatory functions. Although detected in articular tissues, the functional role of miR-155 in inflammatory arthritis has not been defined. We report here that miR-155 is up-regulated in synovial membrane and synovial fluid (SF) macrophages from patients with rheumatoid arthritis (RA). The increased expression of miR-155 in SF CD14⁺ cells was associated with lower expression of the miR-155 target, Src homology 2-containing inositol phosphatase-1 (SHIP-1), an inhibitor of inflammation. Similarly, SHIP-1 expression was decreased in CD68⁺ cells in the synovial lining layer in RA patients as compared with osteoarthritis patients. Overexpression of miR-155 in PB CD14⁺ cells led to down-regulation of SHIP-1 and an increase in the production of proinflammatory cytokines. Conversely, inhibition of miR-155 in RA synovial CD14⁺ cells reduced TNF-α production. Finally, miR-155-deficient mice are resistant to collagen-induced arthritis, with profound suppression of antigen-specific Th17 cell and autoantibody responses and markedly reduced articular inflammation. Our data therefore identify a role of miR-155 in clinical and experimental arthritis and suggest that miR-155 may be an intriguing therapeutic target.

Violence against non-Hispanic Black youths continues to be a significant public health issue for many communities in the United States. For more than two decades, homicide has been the leading cause of death among non-Hispanic Black youths aged 10 to 24 years (http://bit.ly/2N3lXko). Also, the burden of exposure to community violence is disproportionately carried by people of color and people living in economically disadvantaged neighborhoods.1 Public health and allied disciplines have played a key role in raising awareness about the system of individual, interpersonal, and social factors that contribute to the development of youth violence and have conducted several decades of research seeking to understand youth violence and develop youth violence-prevention strategies. These efforts have resulted in an array of evidence-based interventions designed to promote a variety of positive outcomes, including promoting positive relationships, developing problem solving, and diffusing interpersonal conflict. However, these interventions have focused heavily on the individual and interpersonal factors while failing to address broader social and structural factors associated with violence.

Small ponds account for a disproportionately high percentage of carbon dioxide emissions relative to their small surface area. It is therefore crucial to understand carbon flow in these ponds to refine the current global carbon budget, especially because climate change is affecting pond hydrology. High elevation ponds in the Elk Mountains of western Colorado are drying more frequently as the timing of snowmelt advances. We compared CO 2 concentrations and fluxes among ponds of different hydroperiods over diel sampling periods during the course of the 2017 open-water period. CO 2 concentrations were significantly negatively correlated with pond depth and averaged 77.6 ± 24.5 μmol L −1 (mean ± S.E.) across all ponds and sampling events. Ponds were up to twenty times supersaturated in CO 2 with respect to the atmosphere. Flux was highly variable within individual ponds but correlated with time of sampling and was highest at night. Flux averaged 19.7 ± 18.8 mg CO 2 m −2  h −1 across all ponds and sampling events. We also compared flux values obtained using modeled and empirical methods and found that widely-applied models of gas exchange rates using wind-based gas exchange (K) values yielded estimates of CO 2 flux that were significantly higher than those obtained using the floating chamber approach, but estimates of CO 2 flux using globally averaged convection-based K values were lower than those obtained using the floating chambers. Lastly, we integrated soil vs. water efflux measurements with long-term patterns in hydrology to predict how total season-long efflux might change under the more rapid drying regimes and longer seasons that are already occurring in these systems. Because soil CO 2 efflux averaged 277.0 ± 49.0 mg CO 2 m −2  h −1 , temporary ponds emitted 674.1 ± 99.4 kg CO 2 m −2 over the course of the 2017 season from ice-out to refreezing, which was over twice as much as permanent and semi-permanent ponds. Our results emphasize that contributions of CO 2 from small ponds to the global carbon budget estimates will vary with pond hydroperiod and sampling methodology, which have been overlooked given that most previous estimates were collected from limited sampling periods and from pond waters alone. Furthermore, pond CO 2 contributions are predicted to increase over time as pond areas transition from efflux from water to efflux from soil.