29 research outputs found
American Muslim School Leadership: Principal and Teacher Perspectives
This study employed a quantitative research design using a mail survey to explore leadership style in Islamic schools in the United States. The purpose of the study was to describe levels of transformational and transactional leadership of American Muslim principals. Correlational analyses were used to determine the relationship between principal and teacher reports of principals\u27 use of transformational leadership and the relationship of demographic variables to perceptions of transformational leadership. Multiple regression analyses showed that none of the six demographic variables were significant predictors of the variance in principal- or teacher-reported use of transformational leadership. Thirty-three principals responded to the MLQ 5X selfrating form and 143 teachers responded to the MLQ 5X otherrating form. Principals rated themselves higher than their teachers on transformational leadership and lower than their teachers on transactional leadership. Both principals and teachers ranked principals highest in Inspirational Motivation and lowest in Management-by-Exception Passive. Principals rated themselves as being more intellectually stimulating and less often using contingent reward. In schools where teachers were more congruent in their ratings of the principal, they tended to perceive the principals as more transformational than did teachers in schools where teachers were less congruent in their ratings. It appears that where principals are more consistent in their interactions with teachers, teachers have higher opinions of the principal as a transformational leader. Both teachers and principals rated principals of American Muslim schools as fairly high in the use of both transformational and transactional leadership. Comparisons of these findings to other research in the U.S. suggest that American Muslim principals exhibit leadership characteristics very similar to those of other U.S. principals
Preliminary Experiments on Photo-Electro Catalytic Oxidation of Recalcitrant Organic Compounds Dissolved in Water
This thesis presents the design and analysis of photo-electro catalytic oxidation technology for its potential use in water treatment applications. Doping titanium dioxide can effectively improve oxidative reactions. Using minute reactor design adjustments, such as electrolysis, the bases of degrading soluble organic compounds can be improved within the reactor. Applications of doping and secondary catalysis are effective in increasing the process of photoactivity within the catalytic reactor, theoretically increasing the production of sacrificial electron acceptors. Higher degradation\u27s were accomplished using doped chromium titanium dioxide photocatalyst, which degraded significantly larger amounts of organics compared with pure titanium dioxide. Techniques used to accomplish the increased photo-reactivity were doping chromium (III) ion into titanium dioxide crystal lattices and silver ions into the photocatalytic coat. Degradation curves were determined by total organic carbon and the chemical oxygen demand. Calculations of the final rate constants show that lighter molar concentrations have higher rates of degradation
American Muslim School Leadership: Principal and Teacher Perspectives
This study employed a quantitative research design using a mail survey to explore leadership style in Islamic schools in the United States. The purpose of the study was to describe levels of transformational and transactional leadership of American Muslim principals. Correlational analyses were used to determine the relationship between principal and teacher reports of principals\u27 use of transformational leadership and the relationship of demographic variables to perceptions of transformational leadership. Multiple regression analyses showed that none of the six demographic variables were significant predictors of the variance in principal- or teacher-reported use of transformational leadership. Thirty-three principals responded to the MLQ 5X selfrating form and 143 teachers responded to the MLQ 5X otherrating form. Principals rated themselves higher than their teachers on transformational leadership and lower than their teachers on transactional leadership. Both principals and teachers ranked principals highest in Inspirational Motivation and lowest in Management-by-Exception Passive. Principals rated themselves as being more intellectually stimulating and less often using contingent reward. In schools where teachers were more congruent in their ratings of the principal, they tended to perceive the principals as more transformational than did teachers in schools where teachers were less congruent in their ratings. It appears that where principals are more consistent in their interactions with teachers, teachers have higher opinions of the principal as a transformational leader. Both teachers and principals rated principals of American Muslim schools as fairly high in the use of both transformational and transactional leadership. Comparisons of these findings to other research in the U.S. suggest that American Muslim principals exhibit leadership characteristics very similar to those of other U.S. principals
THE EFFECTS OF ANTI-CD20 THERAPY ON SUSCEPTIBILITY TO PNEUMOCYSTIS INFECTION AND THE CD4+ T-CELL SIGNALS THAT MEDIATE CLEARANCE
Pneumocystis is an opportunistic fungal pathogen that presents as a pulmonary pneumonia. Originally characterized as an AIDs-defining illness, Pneumocystis has now reemerged in non-HIV immunocompromised patients. It has been shown that Pneumocystis prophylaxis of can reduce the incidence of infection, severity of disease, and mortality rate in immunocompromised patients. However, prophylaxis is relatively toxic, and only prescribed to defined at risk populations. Anti-CD20 was originally a therapy for B-cell non-Hodgkin lymphomas, but now it’s also used to treat hematological malignancies, autoimmune diseases, and post-transplant lymphoproliferative disease. Studies have shown that up to 30% of patients receiving anti-CD20 antibodies developed Pneumocystis pneumonia, however, many of these patients were also on concomitant immunosuppressive drugs which complicates any analyses of clinical studies. Thus, we generated a murine model of anti-CD20 therapy, and demonstrated treatment does induce susceptibility to Pneumocystis infection. This correlated to an overall decrease in immune response, but more specifically a loss in CD4+ T-cell mediated protection.
The predominant factor required for immunity against Pneumocystis infection is the presence of CD4+ T-cells. This has been validated several times over by clinical data and experimental animal models. Early on, studies have examined the role of T helper 1 (Th1), T helper 2 (Th2), and T helper 17 (Th17) cells. To briefly summarize these studies, Th1, Th2, and Th17 cells can all be detected in the lung during infection, however, removal of their classically defined effector molecules only delayed clearance or had no effect. We examined the importance of each subset of T helper cells by deleting the Stat transcription factors that mediated differentiation. We found that specifically Stat3 was required, however, it was independent of IL-17 and IL-23 signals. We also identified IL-21 as a key cytokine required to mediate clearance. Using a variety of approaches, we determined that GM-CSF and IL-22 play important roles during Pneumocystis infection. GM-CSF+ CD4+ T-cells are critical for T-cell mediated clearance, however, it alone is not sufficient. While IL-22, although not required, was sufficient to reduce burden in IL-21 receptor knockout mice. These data suggest a model of clearance, requiring non-classical T helper cell function
Aspergillus fumigatus preexposure worsens pathology and improves control of Mycobacterium abscessus pulmonary infection in mice
ABSTRACT
Cystic fibrosis (CF) is an autosomal recessive disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. Mutations in this chloride channel lead to mucus accumulation, subsequent recurrent pulmonary infections, and inflammation, which, in turn, cause chronic lung disease and respiratory failure. Recently, rates of nontuberculous mycobacterial (NTM) infections in CF patients have been increasing. Of particular relevance is infection with
Mycobacterium abscessus
, which causes a serious, life-threatening disease and constitutes one of the most antibiotic-resistant NTM species. Interestingly, an increased prevalence of NTM infections is associated with worsening lung function in CF patients who are also coinfected with
Aspergillus fumigatus
. We established a new mouse model to investigate the relationship between
A. fumigatus
and
M. abscessus
pulmonary infections. In this model, animals exposed to
A. fumigatus
and coinfected with
M. abscessus
exhibited increased lung inflammation and decreased mycobacterial burden compared with those of mice infected with
M. abscessus
alone. This increased control of
M. abscessus
infection in coinfected mice was mucus independent but dependent on both transcription factors T-box 21 (Tbx21) and retinoic acid receptor (RAR)-related orphan receptor gamma t (RORÎł-t), master regulators of type 1 and type 17 immune responses, respectively. These results implicate a role for both type 1 and type 17 responses in
M. abscessus
control in
A. fumigatus
-coinfected lungs. Our results demonstrate that
A. fumigatus
, an organism found commonly in CF patients with NTM infection, can worsen pulmonary inflammation and impact
M. abscessus
control in a mouse model.
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Intestinal Interleukin-17 Receptor Signaling Mediates Reciprocal Control of the Gut Microbiota and Autoimmune Inflammation
Interleukin-17 (IL-17) and IL-17 receptor (IL-17R) signaling are essential for regulating mucosal host defense against many invading pathogens. Commensal bacteria, especially segmented filamentous bacteria (SFB), are a crucial factor that drives T helper 17 (Th17) cell development in the gastrointestinal tract. In this study, we demonstrate that Th17 cells controlled SFB burden. Disruption of IL-17R signaling in the enteric epithelium resulted in SFB dysbiosis due to reduced expression of α-defensins, Pigr and Nox1. When subjected to experimental autoimmune encephalomyelitis, IL-17R signaling deficient mice demonstrated earlier disease onset and worsened severity that was associated with increased intestinal Csf2 expression and elevated systemic GM-CSF cytokine concentrations. Conditional deletion of IL-17R in the enteric epithelium demonstrated that there was a reciprocal relationship between the gut microbiota and enteric IL-17R signaling that controlled dysbiosis, constrained Th17 development, and regulated the susceptibility to autoimmune inflammation
Immunology of Cryptococcal Infections: Developing a Rational Approach to Patient Therapy
Cryptococcal meningoencephalitis is responsible for upwards of 15% of HIV-related deaths worldwide and is currently the most common cause of non-viral meningitis in the US, affecting both previously healthy and people with immune suppression caused by cancer chemotherapy, transplantation, and biologic therapies. Despite a continued 30–50% attributable mortality, recommended therapeutic strategies have remained largely unchanged since the 1950s. Recent murine models and human studies examining the role of the immune system in both susceptibility to the infection as well as host damage have begun to influence patient care decisions. The Damage Framework Response, originally proposed in 1999, was recently used to discuss dichotomous etiologies of host damage in cryptococcal disease. These include patients suffering microbiological damage with low host immunity (especially those immunosuppressed with HIV) and those having low (live) microbiological burden but high immune-mediated damage (HIV-related immune reconstitution syndrome and non-HIV-related postinfectious inflammatory response syndrome). Cryptococcal disease in previously healthy hosts, albeit rare, has been known for a long time. Immunophenotyping and dendritic cell-T cell signaling studies on cerebral spinal fluid of these rare patients reveal immune capacity for recognition and T-cell activation pathways including increased levels of HLA-DR and CD56. However, despite effective T-cell signals, brain biopsy and autopsy specimens demonstrated an M2 alternative macrophage polarization and poor phagocytosis of fungal cells. These studies expand the paradigm for cryptococcal disease susceptibility to include a prominent role for immune-mediated damage and suggest a need for careful individual consideration of immune activation during therapy of cryptococcal disease in diverse hosts