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Effect of Melatonin on Neurobehavioral Functioning in Middle-aged Female Rats
Get PDFMiddle-aged female rats were purchased from a reputable breeding center (Charles River). Animals underwent either subcutaneous melatonin pellet implantation or a sham surgery. All rats were then tested on many behavioral tasks (measuring learning and memory). Upon completion of the project, animals were euthanized, and their brains removed and embedded in paraffin for future analyses. Using SPSS (statistical software) the data was analyzed to determine statistical significance.The percentage of Americans over 65 is expected to increase from 56 million to 72 million in 2050. Of importance will be to better understand normal age-related declines in neurocognitive functioning and develop potential interventions that aim to prevent or retard progression to pathological aging (such as Mild Cognitive Impairment or Alzheimer’s disease). Among those diagnosed with these neurodegenerative conditions, women exhibit faster cognitive decline compared to men. Melatonin is an important pineal hormone that not only has chronological properties but has also been found to be a potent neuroprotectant in the brain. Melatonin levels decline with age. Hence, when neurodegenerative conditions are at their peak, melatonin levels are at their lowest. A plethora of animal studies have demonstrated the effectiveness of melatonin in protecting against many central nervous system disorders such as stroke. There is scant information regarding whether melatonin supplementation affects neurobehavioral functioning in normal middle-aged rodents. Hence, the purpose of the present study was to examine whether chronic melatonin administration (50 mg, 90-day pellets implanted s.c.) impacts neurobehavioral functioning in middle-aged (12 months) female rats. Age-matched non-treated middle-aged female rats were also included (sham operated controls). Approximately 44 days following pellet or sham pellet implantation, rats were tested on an open field, object recognition, spatial recognition, Morris Water Maze, and Y-maze task. Melatonin at the dosage used, did not improve spatial or visual memory in middle-aged female rodents. Although melatonin did not affect behavior, further study will need to examine whether melatonin positively affected the brain. Melatonin is known to have neurogenic properties; hence it will be of interest to examine the brain of these animals to determine whether neurogenesis was positively impacted by treatment. As well, older women also show a decline in estrogen with age. Hence, it will be of interest to determine whether combined melatonin and estradiol replacement would affect neurobehavioral functioning
EFFECT OF A DIRECT-FED MICROBIAL ON FEEDLOT PERFMORMANCE, CARCASS CHARACTERISTICS AND PREVALENCE OF SALMONELLA IN FED-BEEF HEIFERS
No full textSalmonella is a naturally occurring bacteria that is known to cause upwards of 1.35 million cases of foodborne illnesses annually. Ground beef products may be manufactured from trimmings containing Salmonella infected lymph nodes, which has led to pending rulemaking by USDA-Food Safety and Inspection Service to declare Salmonella as an adulterant. Direct-fed microbials are a pre-harvest intervention for reduction of Salmonella. The objective of this study was to determine the efficacy of a direct-fed microbial upon the prevalence and enumeration of Salmonella in feces and lymph nodes. Heifers (n=1,394; 291 ± 9.9 kg) were blocked by day of arrival and randomly allocated to one of two treatments (0 or 2g/animal/d; CON and 10-G, respectively) with ten pens per treatment. Heifers fed 10-G were provided 1 billion CFUs per animal per day of Lactobacillus acidophilus, Enterococcus faecium, Pediococcus pentosaceus, Lactobacillus brevis and Lactobacillus plantarum. Twenty-four animals were randomly selected from each pen for Salmonella sampling. Rectoanal mucosal swab samples (RAMs) were obtained at initial processing and harvest; subiliac lymph nodes were collected at harvest. In addition, pen surface fecal pats were collected and composited by pen (10 pats per composite, 5 composites per pen) on days 0, 52, 120 and 170. Mixed models were used to analyze live performance, carcass characteristics and Salmonella prevalence and concentration with treatment used as fixed effect, block
used as random effect and pen as experimental unit. Repeated measures was used to analyze Salmonella prevalence and concentration across time using the unstructured covariance structure. Dry matter intake (P = 0.63), average daily gain (P = 0.69), gain:feed (P = 0.81) and final body weight (P = 0.79) did not differ between treatments. Neither morbidity (P = 0.90) nor mortality and railer rates (P = 0.55) were different between treatments. Hot carcass weight (P = 0.14), dressed carcass yield (P = 0.53), 12th rib fat depth (P = 0.73), ribeye area (P = 0.13), calculated empty body fat (P = 0.71) or marbling score (P = 0.20) were not different between treatments. Yield grade distributions did not differ between treatments (P ≥ 0.44), however cattle fed 10-G tended (P = 0.06; 15.78 vs 20.34%) to be represented by fewer USDA Select carcasses and more (P = 0.09; 73.62 vs 77.97%) USDA Choice carcasses. Livers from cattle fed 10-G tended (P = 0.10; 12.26 vs 9.23%) to have a lower frequency of abscesses when compared to CON. Heifers fed 10-G also had fewer (P = 0.04; 5.27 vs 8.51%) severe liver abscesses. Salmonella prevalence of RAMs did not differ between treatments at initial processing (P = 0.92; CON = 11.6%, 10-G = 11.5%) or at harvest (P = 0.92; CON = 99.0%, 10-G = 98.6%), however RAMs differed (P < 0.01) in Salmonella prevalence between the two collection times. Likewise, Salmonella log (mpn/g) of RAMs did not differ between treatments at initial processing (P = 0.63; CON = 0.28, 10-G = 0.30) or at harvest (P = 0.63; CON = 4.40, 10-G = 4.05), while log (mpn/g) of Salmonella increased (P < 0.01) over the feeding period. Moreover, composited pen level fecal pats were similar for Salmonella prevalence (P = 0.73; CON = 69.0%, 10-G = 67.0%) between treatments, but prevalence increased (P < 0.01) sharply during the initial 52 d then plateaued during the remainder of the finishing period. However, Salmonella prevalence differed (P < 0.01) among sampling days. Cattle fed 10-G had a lower frequency of Salmonella positive lymph nodes (P = 0.01; CON = 15.80%, 10-G = 7.41%) than CON. However, Salmonella log (mpn/g) of lymph nodes did not differ between treatments at harvest (P = 0.34; CON = 0.73, 10-G = 0.34). This data indicates that cattle fed 10-G decreased rates of severe liver abscesses without altering live animal performance or carcass characteristics as well as fewer Salmonella positive lymph nodes, which in turn can likely improve public health by reducing the number of foodborne illnesses caused by Salmonella
INVESTIGATION OF THE EFFECT OF AN ADDITIVE MANUFACTURING PROCESS ON THE MECHANICAL PROPERTIES OF 316L STAINLESS STEEL
No full textThis body of work provides a general analysis of the mechanical properties of 316L stainless steel prints that have been generated with laser powder bed fusion (LPBF). Powdered 316L stainless steel was utilized in the selective laser melting process to generate samples suitable for materials analysis. The aim of this body of work is to analyze how a specified LPBF process affects the material properties of 316L stainless steel. Thorough understanding of the effect that the LPBF process has on 316L stainless steel material properties may provide designers and engineers with information that aids in component design and reliability. The findings presented herein demonstrate that the LPBF process produces a state of material properties that are unlike its traditionally manufactured counterparts. Thorough investigation of the tensile properties, hardness, density, and microscopic properties of the material provide a material performance profile. This material profile was compared to the profile of a traditionally manufactured and annealed 316L steel samples. The results show that the use of LPBF can be used to generate high density, high strength components in the as-printed condition. Additionally, Anisotropic material performance was identified and measured in tensile tests, and in metallurgical microscopy
PERCEPTIONS OF PEER SOCIAL JUSTICE ACTIVISM IN REGIONAL UNIVERSITY STUDENT-ATHLETES
No full textHistorically speaking, sports and politics have always been intertwined, and in this current time, more attention has been given to this fact. As athletes and their followers continue to become more vocal, they have used their increased voice to highlight controversial issues such as alleged police brutality, voting rights, transgender rights, and other issues as well. While professional athletes often get the spotlight to draw awareness to the discussed topics, collegiate athletes have also drawn light to such issues in the past and are starting to do so more frequently in the modern day. Given this development, the current study surveyed 93 student-athletes at a university located in the Southwest region of the United States. A series of results showed that most student-athletes are open and willing to listen to their teammates and colleagues when they engage in social justice activism. Political affiliation was the strongest indicator for determining whether a student-athlete was open to listening to and engaging in social justice activism. Other strong indicators were race and gender; however, sex was not associated to the social justice activism. Future research may look to engage in whether time in college changes these feelings toward activism and whether chemistry and rapport between teammates play a significant role in affecting social justice activism attitudes on campus
ENGINEERING A MICROFLUIDIC DEVICE FOR THE INVESTIGATION OF ATMOSPHERIC ICE NUCLEATION
No full textAtmospheric ice-nucleating particles (INPs) promote the formation of ice particles in clouds. They usually modulate the properties of clouds, precipitation, and climate. The effect of INPs is predominant in low Arctic mixed-phase clouds. However, ambient ice nucleation in clouds is a complex process encompassing multiple freezing mechanisms. Limited knowledge about nature and the role of high-latitude INPs in the climate system is available. To fill the knowledge gap, this thesis project developed the West Texas A&M University Microfluidic Static Droplet Array (WT-MFSDA) platform for studying atmospheric ice nucleation, specifically immersion freezing. WT-MFSDA combines a microfluidic device containing interconnected droplet parking traps, a unique method of hand pipetting to create an array of INP-laden nanoliter-sized droplets, and a commercialized cooling unit for visualization and characterization of freezing events of hundreds of individual droplets. Each droplet is geometrically separated from each other and enveloped with a thin film of mineral oil. This spatial arrangement increases the reliability and reproducibility of the measurement by eliminating the artifacts due to surface contact, mass transfer, and/or evaporation. This platform is useful to simulate and investigate the immersion freezing of water and/or any INP-involved suspension down to the homogenous freezing temperature (below -35 °C) at a wide range of cooling rates from 0.01 to 30 ℃ per minute, which corresponds to atmospherically relevant cloud updraft velocities. A systematic uncertainty in terms of temperature is ± 0.3 °C. The device performance is verified with the known composition of bulk powder INP surrogates, such as illite NX, Snomax®, and microcrystalline cellulose. The results from nL-freezing assays of WT-MFSDA were compared and verified to/against the results of published immersion freezing results. The WT-MFSDA immersion freezing platform shows the potential as an affordable and handy tool for studying ice nucleation in clouds
Socio-psychological theories and contemporary research: Can unmet needs contribute to victimization in the workplace?
No full textThis study applied descriptive phenomenology using an inductive thematic analysis approach to explore women's online, public self-reflection about harassment in the workplace. Themes describing emotional experiences were created from the inductive analysis and compared with existing literature to identify any consistencies and discrepancies. The data was collected from the public website, InHerSight. InHerSight is a website that was developed so that women can share their experiences of disparities in their work environments.The following paper seeks to uncover potential support for workplace victimization through an examination of employee's needs and needs-based motivation theories. An inductive thematic analysis was utilized to explore a sample of 721 web-based comments relating to workplace harassment and conflict. The researchers conclude that if underlying workplace needs can be identified, victims of workplace harassment can be empowered through the development and attainment of unmet needs. The study calls for further research, and consideration of, a managerial shift in practice regarding workplace harassment. Specifically, based on the study's conclusions, managers should contemplate a proactive development approach to employees' needs by seeking to empower victims of workplace mistreatment
China's Import Demand Analysis of Grain Sorghum from USA
No full textThe data collection methodology was secondary Data Sources such as USDA-ERS, FAO Statistics, USDA-FAS, World Bank, and IMF.Sorghum is an ancient grain which is the most commonly used feed grain for livestock. The United States is the world's second largest producer and top exporter of grain sorghum. It is grown in more than a dozen states across the country and sorghum belt runs from South Dakota to Southern Texas. China, one of the fastest growing economy, is the major destination of U.S. grain sorghum. This research study examines the determinants of an import demand function for U.S. sorghum in China considering the macroeconomic variables such as Gross Domestic Products (GDP) and exchange rates (Yen-US$). The time series data from 1991-2020 were used for this analysis. This paper follows the single equation import demand model developed by Thursday and Thursday (1984). China's import demand for sorghum was determined as a function of derived demand of sorghum which is constructed as with the grain sorghum import price, domestic corn price, exchange rate, the country's GDP, and number of livestock production. In 2021, The United States produced about 448 million bushels of grain sorghum and exported 267.2 million bushes to China as chief importer (USDA ERS, 2021). These statistics indicates, U.S. sorghum export market is largely depending on China's sorghum import demand. It is projected that China will continue this import volume while sorghum is low cost feed grain and is substitute for high price corn. The results of this study will be an important sorghum trade analysis and recommendation for world sorghum trading countries, especially for China to implement favorable import policies for US sorghum. On the other hand, this analysis will also be beneficial for US sorghum producers in assessing their export potential not only to China's livestock industry but also other export markets
Entrevista a Daisy Pando
No full text"Interview with María Pando conducted by Daisy Pando as part of the Oral History Project "Forgotten Frontera."
Entrevista a María Pando realizada por Daisy Pando como parte del Proyecto de Historia Oral "Forgotten Frontera."Center for the Study of the American Wes
Antimicrobial Effectiveness of a Copper Surface Patch
Get PDFMicrobial resistance to traditional antibiotics and household cleaning chemicals is an increasing problem in today’s climate. The world was recently in a global pandemic, and alternative techniques and products that can kill microbial organisms are now in high demand. One new product is Copper Clean™, an EPA approved antimicrobial surface patch intended for use on high-contact surfaces. Copper Clean’s™ alloy is a patent-pending technology that contains >90% Copper by weight, produced by Buffalo Technology Group. Our objective was to test Copper Clean’s™ ability to kill representative organisms from the human microbiome and environment using a time-kill assay. Seven organisms were used, including Gram-positive (Staphylococcus epidermidis, Streptococcus mutans, Methicillin-Resistant Staphylococcus aureus, and Bacillus megaterium) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa, and Salmonella enterica). We observed a ≥5-log reduction of Staphylococcus epidermidis, Methicillin-Resistant Staphylococcus aureus, Streptococcus mutans, and Escherichia coli after 2-3 hours of contact with Copper Clean™ in an aqueous environment when compared to our control. Our results demonstrate the effectiveness of Copper Clean™ against representative environmental and human microbiome organisms
Entrevista a Alvina Briseño
Get PDF"Interview with Alvina “BB” Briseño conducted by Dr. Alex Hunt as part of the Oral History Project "Forgotten Frontera."
Entrevista a Alvina “BB” Briseño realizada por Dr. Alex Hunt como parte del Proyecto de Historia Oral "Forgotten Frontera."Center for the Study of the American Wes