The effect of ultrasound on polycyclic aromatic hydrocarbons in aqueous media

Thesis (Ph.D.) University of Alaska Fairbanks, 1992Polycyclic aromatic hydrocarbons (PAHs) are common environmental contaminants which pose a potential threat to human health and environmental quality. An investigation to determine the ability of ultrasonic radiation to desorb PAHs adsorbed on the surface of solid substrates and to chemically alter these chemicals in aqueous solutions and suspensions has been conducted. The data indicate that enhanced transport of adsorbed PAH from a glass surface can be induced by treatment with ultrasonic radiation of varying intensities. Furthermore, chemical alteration can be induced under intense (147 watts/cm\sp2) ultrasonic treatment. The extent of reaction is a function of irradation time at this ultrasonic intensity. Reaction products from ultrasonic treatment of aqueous solutions of biphenyl, analysed by gas chromatography (GC) and mass spectrometry (MS), include ortho-, meta-, and para-(1,1 biphenyl) -ol. The principal product from ultra-sonic treatment of aqueous phenanthrene appears to be a phenanthrenediol. The use of ultrasound to treat PAH contaminated aqueous solutions in tandem with other methodologies appears promising. However, the toxicity of reaction product mixtures produced by ultrasonic treatment remains to be determined

Compassion Fatigue Among Resident Assistants at Five Illinois Public Institutions : A Mixed Methods Approach

Compassion fatigue, a stress response caused by helping those who have experienced trauma, is a rapidly rising problem for student affairs professionals (Carter, 2019). Among student affairs professionals and paraprofessionals, the resident assistant (RA) is potentially one of the most susceptible populations to compassion fatigue, due to working where they live, which creates a constant need to be on. In addition, they are expected to support students who are increasingly presenting with mental health challenges. This explanatory mixed methods method study sought to first determine the prevalence of compassion fatigue, including its components burnout and secondary trauma, among RAs at five four-year public institutions in IL, then to understand the nature of compassion fatigue among those vital residence life student personnel. Findings suggest that about 75% of RAs experience at least moderate compassion fatigue. In addition, the expectation from students and supervisors that RAs be available 24/7, may contribute to this. Implications for practice and future research are also presented. Keywords: resident assistants, compassion fatigue, burnout, secondary traumatic stres

Those New Barley and Flax Varieties

Growers in northwestern Iowa will be hearing more about several new and improved varieties of barley and flax. Particularly promising varieties for Iowa are Traill and Liberty barley as well as Arny and Bolley flax

A Comparison Of Corruption Perceptions: The Czech Republic And Sloakia

When the Soviet Union disintegrated in 1989 Czechoslovakia regained its independence from Soviet domination as a result of a so called “velvet revolution.” Four years later in 1993 the two parts of Czechoslovakia separated in a “velvet divorce” to become two independent states:  The Czech Republic and Slovakia. Slovakia was at the time less developed than the Czech Republic. Previous studies of corruption indicate that the less developed a country is the more corruption would be expected. This study uses data from the Business Environment and Economic Performance Survey (BEEPS) of the World Bank and the European Bank for reconstruction and Development to explore perceptions of corruption in the two countries

Developing Effective Faculty Competencies For Teaching International Business Topics

Faculty are increasingly called upon to teach topics in international business. To ensure teaching success, faculty need to develop knowledge of countries, international organizations, economies, culture, interpersonal skills in international settings, and foreign business practices. The purpose of the paper is to demonstrate how faculty can obtain the skills and knowledge necessary to teach international topics efficiently and cost effectively

CORRUPTION AND OBSTACLES FOR CONDUCTING BUSINESS IN FORMER FRENCH WEST AFRICA

This study examines the extent of corruption and obstacles to conducting business in some former French West Africa countries. Methodology: This study uses business owner’s and mangers perceptions about the use of gifts or informal payments and obstacles to conducting business in five African countries.  Data comes from the World Bank Institute and the European Bank for Reconstruction and Development’s Business Environment and Economic Performance study.  Data from Benin, Burkina Faso, Niger, Senegal, and Togo were examined.  Univariate general linear analysis was used to discover statistical differences between factors by country. Main Findings: Results show Senegalese managers and owners perceived the lowest obstacles to conducting business among the five countries.  Togo business managers and owners are slightly less positive about obstacles they face in their businesses.  Businesses in the five countries on average pay about eight percent of their annual sales as gifts/informal payments. Limitations: The study uses data that is about ten years old.  The political and economic environment may have changed in these countries since data collection. Social Implications: The significant level of obstacles business faces in these countries may significantly reduce foreign direct investment in these countries.  Electricity is an obstacle in most of these countries reducing the ability if not the interest in conducting business. Originality/Novelty of the Study: The French strategy in this region for three hundred years was to rule through the military not the development of economic systems.  The results of this strategy may still be apparent in the number and degree of obstacles facing business only 50 years after independence

QUANTIFYING VARIABILITY IN COORDINATION DURING RUNNING

It has been suggested that within-participant variability in coordination may have a functional role to play in human movement. The purpose of this study was to compare the variability in coordination for one participant, quantified utilising two previously used techniques. Hip and knee flexion- xtension angles during the stance phase were calculated and interpolated to 100 data points, for 10 trials of running at 3.8 m/s. The standard deviation in continuous relative phase and coefficient of correspondence from vector coding were calculated at each data point. The two techniques gave similar indications of coordination variability in early stance, but were contradictory towards the end of stance. The results of this investigation suggest that authors conducting independent studies, using different analysis techniques, may draw conflicting conclusions about the variability in coordination

COORDINATION VARIABILITY DURING OVERGROUND, TREADMILL AND TREADMILL-ON-DEMAND RUNNING

The purpose of this study was to investigate differences in lower extremity coordination variability between overground, treadmill and treadmill-on-demand running. A modified normalised root mean square difference technique was used to quantify the variability in lower extremity coordination calculated from the kinematic data collected during ten strides of overground, treadmill and treadmill-on-demand running at 3.5 m.s". Although no significant differences were observed between the two types of treadmill, significantly reduced (p < 0.02) coordination variability was seen in the treadmill and treadmill-ondemand conditions compared to overground locomotion. Therefore, a constant belt speed during treadmill locomotion does not account for the differences seen between overground and treadmill running and further work is required to determine factors that cause the difference

HIV-1 infection and CD4 T cell depletion in the humanized Rag2(-/-)γc(-/- )(RAG-hu) mouse model

BACKGROUND: The currently well-established humanized mouse models, namely the hu-PBL-SCID and SCID-hu systems played an important role in HIV pathogenesis studies. However, despite many notable successes, several limitations still exist. They lack multi-lineage human hematopoiesis and a functional human immune system. These models primarily reflect an acute HIV infection with rapid CD4 T cell loss thus limiting pathogenesis studies to a short-term period. The new humanized Rag2(-/-)γc(-/- )mouse model (RAG-hu) created by intrahepatic injection of CD34 hematopoietic stem cells sustains long-term multi-lineage human hematopoiesis and is capable of mounting immune responses. Thus, this model shows considerable promise to study long-term in vivo HIV infection and pathogenesis. RESULTS: Here we demonstrate that RAG-hu mice produce human cell types permissive to HIV-1 infection and that they can be productively infected by HIV-1 ex vivo. To assess the capacity of these mice to sustain long-term infection in vivo, they were infected by either X4-tropic or R5-tropic HIV-1. Viral infection was assessed by PCR, co-culture, and in situ hybridization. Our results show that both X4 and R5 viruses are capable of infecting RAG-hu mice and that viremia lasts for at least 30 weeks. Moreover, HIV-1 infection leads to CD4 T cell depletion in peripheral blood and thymus, thus mimicking key aspects of HIV-1 pathogenesis. Additionally, a chimeric HIV-1 NL4-3 virus expressing a GFP reporter, although capable of causing viremia, failed to show CD4 T cell depletion possibly due to attenuation. CONCLUSION: The humanized RAG-hu mouse model, characterized by its capacity for sustained multi-lineage human hematopoiesis and immune response, can support productive HIV-1 infection. Both T cell and macrophage tropic HIV-1 strains can cause persistent infection of RAG-hu mice resulting in CD4 T cell loss. Prolonged viremia in the context of CD4 T cell depletion seen in this model mirrors the main features of HIV infection in the human. Thus, the RAG-hu mouse model of HIV-1 infection shows great promise for future in vivo pathogenesis studies, evaluation of new drug treatments, vaccines and novel gene therapy strategies

Pulmonary histoplasmosis presenting as chronic productive cough, fever, and massive unilateral consolidation in a 15-year-old immune-competent boy: a case report

Severe histoplasmosis is known to be among the AIDS-defining opportunistic infections affecting patients with very low CD4 cell counts in histoplasmosis-endemic areas. Histoplasma capsulatum var. duboisii is common in West and Central Africa, where it occurs in both HIV/AIDS and non-HIV patients. Few cases of life-threatening histoplasmosis in immune-competent individuals have been reported worldwide. We describe a case of pulmonary histoplasmosis diagnosed on the basis of autopsy and histological investigations. A 15-year old East African immune-competent boy with a history of smear-positive tuberculosis and a two-year history of rock cutting presented to our hospital with chronic productive cough, fever, and massive unilateral consolidation. At the time of presentation to our hospital, this patient was empirically treated for recurrent tuberculosis without success, and he died on the seventh day after admission. The autopsy revealed a huge granulomatous lesion with caseation, but no acid-fast bacilli were detected on several Ziehl-Neelsen stains. However, periodic acid-Schiff staining was positive, and the histological examination revealed features suggestive of Histoplasma yeast cells. Severe pulmonary histoplasmosis should be considered in evaluating immune-competent patients with risk factors for the disease who present with pulmonary symptoms mimicking tuberculosis