Texas A&M University-Kingsville: AKM Digital Repository
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The effect of phosphate in the production of tetracycline by the fermentation of Streptomyces aureofaciens
No full textTetracycline is a well-known antibiotic that is used against gram-positive and gram-negative bacteria. Being a broad-spectrum antibiotic, tetracycline can be used to treat against multiple different pathogens present. The production of antibiotics is important to the
pharmaceutical industry, looking at different ways to optimize the production to get the highest concentration of production with the lowest cost can be beneficial. Manipulating certain factors in the fermentation process can change the outcome of what is produced. The key nutrients that are in the fermentation broth also play a big role in the later outcome of the production of any
antibiotic. Slight changes to the amount of these key nutrients can play a role during the growth phase and the production phase of the bacteria. The key nutrients in a fermentation broth is everything that is essential for the bacteria to survive, one of which is phosphate. By looking at how the phosphate can affect the overall process of the production of tetracycline, there can be a better understanding of the process and how to improve the production. It has been shown that there needs to be a limited amount of phosphate in the later stages of production in order to get an increased amount of tetracycline in the end. This research uses experimental and mathematical modeling techniques to observe how different amounts of phosphate present in the
fermentation broth affected the outcome of tetracycline production
A comparative study of alternative energy usage in the global logistics sector
No full textLogistics is a key driver in supply chain management and the goal of the driver is to meet the customers’ demands timely and cost-effectively. The advancement of the driver plays a crucial role in promoting the growth of the economy. However, all logistics vehicles are still heavily relying on fossil fuel-based sources and are responsible for approximately a quarter of global CO2 emissions. Therefore, one of the major ways to address the impact of logistics on climate change is to study the statistical data, identify the trend of adopting alternative energy sources in this sector, and adopt necessary measures to accelerate the efforts. In this research, the data related to the logistic performance index, greenhouse gas emissions change, renewable energy consumption rate, etc. from the sources such as World Bank and OurWorldinData.org are explored, and a comparative study among the most populated nations across all continents is conducted. To identify the rate of transition among the countries, different statistical tools such as mean, standard deviation, and regression are applied. The result shows that the adoption of alternative energy sources in the logistics industry is independent of population size and economic growth. The rate of adoption of alternative energy sources among the studied countries can be arranged in the following order: Brazil>USA>Australia>China>Russia>Nigeria
Novel snake venom serine protease (SVSP) isolated from the Mohave rattlesnake venom plays a role in hemostasis and inflammation
No full textSnake venoms are complex mixtures of toxins with diverse biologically active peptides and proteins. Among these toxins, the snake venom serine proteases (SVSPs) are found globally in the Viperidae family. Though the SVSPs have been well characterized regarding their effects
on the disruption of hemostasis and hypotension, more investigation is needed to explore their abundance in medically relevant snakes, identify their molecular targets, mechanism of action, and determine their therapeutic value. This study aimed to determine the biological activities of a SVSP from the Mohave rattlesnake. We purified a SVSP from the venom Crotalus scutulatus
scutulatus type A rattlesnake, named Css-SVSP, using two chromatography steps on a C18 reverse phase and followed by an anionic exchange diethylaminoethy (DEAE) column chromatography. After validation by N-terminal sequencing, and mass spectrometry analysis,
Css-SVSP shared 96.6% homology with a SVSP from Crotalus atrox. Css-SVSP was tested for hemostatic activities using whole human blood on a Sonoclot analyzer and determined its fribrino(geno)lytic and amidolytic activities. Css-SVSP had pro-coagulant activity in whole
blood and showed fibrino(geno)lytic, thrombin-like, and kallikrein-like activities. The effects on cell viability and cell activation were measured in vitro using monocyte-derived macrophages (MDM) obtained from the U937 and myotubes C2C12 cell lines. Css-SVSP modulated cell viability of myotubes, cell activation in MDM and measured cytokine release in MDM. Next, Css-SVSP was injected intravenously in the tail with doses of 5 μg, 10 μg, and 20 μg/mouse, and the effects on mice behavior were monitored for 1 hour. All mice injected with the toxin showed episodes of “face washing.” However, at the highest dose, myoclonus consisting of laterally
directed movements of the hind limbs, were noted in the first minutes post-injection. These results reveal new features for this SVSP in biological systems beyond blood coagulation, thus contributing to understanding the pathophysiology of snake envenoming by Mohave
rattlesnakes
The community of the Japanese Americans in the Rio Grande Valley
No full textMany studies have recently been made concerning Japanese Americans. However, these studies have been forcused on Japanese Americans who lived on the west coast of the United States, particularly in California. In spite of the fact that since the early 1900's other Japanese communities have developed outside of the west coast, very little has been written about them.
The community of Japanese Americans in the Rio Grande Valley is no exception. Although a large number of Japanese Americans have been living in the area for more than sixty years, nothing has been done on them except by Shinichi Kato who included a brief description in his book, History of Japanese Immigration to the United States. The purpose of this paper, therefore, is to repair that omission
Thermal stratification in hot water tanks: a review, an empirical fit, a novel model and a prototype diffuser
No full textThe main purpose of a temperature stratified storage system is to keep the hot and cold storage layers separate from each other for increased system thermal energy efficiency of engineered systems. Systems connected to the thermal storage (i.e. trans-critical CO2 heat pumps, solar-thermal fields, chilled-water turbines, etc.) benefit from having two available temperatures (i.e. cold and hot) and a lower overall temperature of the thermal storage which results in less energy loss to the environment. This study develops empirical correlations for a model that represents the thermocline behavior for inlet Reynolds numbers (170 to 22,300) and inlet tank Richardson numbers (0.01 to 376), commonly experienced in residential-scale hot water tanks. The vertical-tube inlet correlation work allows modeling of the vertical-tubes impact on the thermocline and for one type of diffuser, the correlations are valid as a function of insertion depth in thermally stratified tanks for inlet tank Richardson number > 2.5. Eddy diffusivity correlations (Table 11, section 2) were developed for residential-style thermal energy storage tanks that will help impact the design of inlets for tanks based on efficiency (e.g. first-hour rating or extraction efficiency) as well as information on which type of vertical-tube inlet should be used to maximize (lower tank epsilon) or minimize stratification (higher tank epsilon). The difference of 3 to 8 % extraction efficiency was found based on the type of vertical-tube inlet used at the same installation height with an inlet Ri > 2.5. A vertical-inlet tube was prototyped and tested that may be of interested to the industry as it shows lower epsilon values at higher Reynolds number than some vertical-inlet tubes on the market and similar extraction efficiencies to those on the market when an anti-siphon orifice is added to the tube
Evaluation of the effectiveness of Texas Community Futures Forums
No full textWith the establishment of the Texas A&M AgriLife Extension Service, communities have depended on Extension Agents to address relevant needs. Extension Agents have used different approaches such as the Texas Community Futures Forum to obtain information on issues affecting people. The problem was that Texas Community Futures Forums have never been evaluated from the perception of Extension Agents. The purpose of this concurrent multi-modal cross-sectional survey research was to evaluate the perceptions of Texas A&M AgriLife Extension Agents (Extension Agents) regarding the effectiveness of the Texas Community Futures Forum (TCFF) in their communities. A process evaluation framework and five research questions guided the study. Two of the research questions posed asked whether there was a significant difference among how well AgriLife Extension programs meet the four program areas of needs and the importance among the four program areas identified in the Community Forum. A third question asked the extent to which competing priorities keep Extension Agents from meeting the needs identified in the Community Forum. The last two open-ended questions requested responses from participants regarding changes the community experienced from conducting the Community Forum and the support necessary for Extension Agent to further conduct the Community Forum. A concurrent multi-modal survey research design approach was taken. Closed and opened questions were asked of 459 Extension Agents throughout Texas; 161 Agents responded. Descriptive and inferential statistics were used to analyze numeric data. A one-way ANOVA was employed to test null hypotheses of no differences. Narrative comments were coded using open and axial methods, and themes were identified. For research question 1, a one-way ANOVA indicated a statistically significant difference among how well AgriLife Extension programs met the four program areas of needs identified in the Community Forum with a moderate to large effect size. Tukey HSD post hoc test indicated significant pairwise differences between CED and ANR, CED and FCH, CED and 4-H/Youth, and ANR and FCH. For research question 2, a one-way ANOVA indicated a statistically significant difference in importance among the four program areas identified in the Community Forum with a moderate to large effect size. Games-Howell post hoc test disclosed significant pairwise differences between ANR and FCH, ANR and CED, FCH and 4-H/Youth, and 4-H/Youth and CED. For research question 3, other competing priorities were most noted for keeping Extension Agents from meeting the needs identified in the Community Forum. The theme that emerged was additional expectations beyond daily workload which included two categories administrative and other daily tasks and expectations, and 4-H responsibilities. The theme that emerged from research question 4 which was consistent throughout all program areas was new programming. Several themes emerged from the final research question on the type(s) of support necessary to further conduct the TCFF at the county, district, and state level: Involvement from community and stakeholders, additional resources, support and guidance, prioritize administrative directives to avoid impacting local programming needs, and provide resources to effectively administer the TCFF
Design and simulation of mobile robot with slam and path planning algorithm
No full textIn this thesis, the simulation-based investigation of a Turtlebot mobile robot in an environment created in ROS using methods such as an Occupancy Grid SLAM (Simultaneous Localization and Mapping) and performed navigation using RRT* path planning. Also, the ability of an autonomous robot to navigate in conflict situations from one point to another in an unknown environment has been addressed while assuring collision avoidance. The navigation of the autonomous robot in an environment with random and live obstacles is one of the main challenges faced by mobile robot technology. Robotic navigation path planning is an axial problem because it is complex and time-consuming for the robot to select an ideal path. Before starting the navigation, the robot must achieve self-localization in an unknown environment known as SLAM. Simultaneous Localization and Mapping (SLAM) and path planning are the main factors that decide efficient path planning for an autonomous robot. SLAM problems can be solved using various methods but mainly rely on the sensors' accuracy, such as camera, LIDAR, etc. Even after successfully mapping the environment, navigating through the obstacles to find the optimum path to a goal location is challenging. In this simulation, a map is constructed using Gazebo software. Then, localization of the robot on the map is achieved using the LIDAR sensor data and using the Occupancy grid SLAM method while controlling the robot manually. The next step was to develop the ROS nodes needed for navigation using python language, which establishes the communication between the client and the navigation server. Different ROS nodes required to perform the navigation are initiated by creating the navigation launch file. The RRT* algorithm is implemented to find the global path from an initial location to a goal location. The navigation of the mobile robot is performed, and the data obtained during the navigation are stored in a ROS bag file. These data are then plotted to understand the robot's behavior under different conditions
Coordinating pre-and post-disaster resource allocation at multiple locations
No full textResearchers, government agencies and relief organizations continually seek ways to minimize the impact of disasters by coordinating preparedness and relief efforts. This study aims to determine the optimal resource allocation of preparedness and relief at Multiple Distribution Centers (MDCs) and Potential Affected Locations (PALs). To tackle this resource allocation problem stated above, we develop a two-stage stochastic mixed-integer programming model that optimally allocates pre-disaster preparedness and post-disaster relief at multiple locations, subject to a fixed budget. The correlation of disaster occurrence at multiple locations is described by the model with conditional probability. Disaster magnitudes are parametrically described as discrete probability distributions. The effectiveness parameters are integrated into the model to represent the mitigation effect of preparedness and relief. We numerically solve the model and carry out sensitivity analyses to compare the effects of different parameters such as unit cost of pre-disaster preparedness and relief, effectiveness of preparedness and relief, disaster uncertainty, and disaster magnitude. This research provides new insights on resource allocation at multiple locations for disaster loss minimization
Mormon migrations, 1846-1848
No full textWhen thinking of the Mormons the average person average person only thinks of Utah, Brigham Young, polygamy, and the great migration. The vast effect the saints, as they came to be called, had on America is seldom realized. The founder of the church, Joseph Smith, is little heard of; yet he is known as one of the most remarkable figures of the nineteenth century
Bank deposit insurance in the United States
No full textIn the United States the protection of depositors through the use of insurance or guarantee plans dates back to 1829 when the Safety-Fund banking system was inaugurated in the New York State. Under the New York Safety-Fund system, which is known as the "grandfather" of the Federal Deposit Insurance Corporation, each bank paid into a guarantee of Safety-Fund an amount equal to three percent of its capital stock. While the law specifically stated that safety- fund was to be used for the guaranty of all the debts of the banks, it appears that the intention of the law was to provide security for note issues. At that time deposit banking was so little developed that the farmers of the law apparently overlooked the fact that bank debts might be occasioned by deposits