THE ANTIBACTERIAL ACTIVITY OF CLAUSENA ANISATA HOOK, A SOUTH AFRICAN MEDICINAL PLANT

Background: Clausena anisata Hook also known as Iperepesi in Xhosa language is a medicinal plant used traditionally for the treatment of various ailments and some opportunistic infections associated with tuberculosis (TB). Patients in South Africa based on the phytotherapeutic information on this species in the Eastern Cape, use this medicinal plant. Hence, the antibacterial activity of various solvent extracts of the leaves and barks were respectively, evaluated using selected bacterial strains. Method: The leaves and stem bark were tested against 10 selected strains of Gram - positive and Gram - negative bacteria through the agar dilution method. Acetone, dichloromethane and water extracts were used for the extraction. MIC was determined at different concentrations (0.1mg/ml, 0.5mg/ml, 1mg/ml and 5mg/ml) and the results obtained were compared to that of standard antibiotics. Result: The acetone extract of the leaves were more active against both Gram-positive and Gram –negative bacteria with MIC ranging from 0.1 mg/ml - 0.5 mg / ml. The dichloromethane extract of the bark showed appreciable activities against Staphylococcus aureus (ATCC 6538) (MIC: 0.1mg /ml) Escherichia coli and, Streptococcus pyogenes with an MIC of 5mg/ml respectively. On the other hand, the aqueous extract of the leaves showed no activity against the tested organisms with the exception of the aqueous bark extract which inhibited Staphylococcus aureus (MIC: 0.5mg/ml) and Pseudomonas aeruginosa (MIC: 5mg/ml). Conclusion: This study confirmed the antibacterial activities of acetone extract of the leaves of Clausena anisata. The capability of this extract to inhibit both Gram positive and negative bacteria is an indication that the extract is a potential broad spectrum antibacterial. The result of this study further justified its indigenous use for the treatment of bacteria commonly associated with TB especially among the people of Nkonkobe Municipality

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No abstract.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78300/1/20291_ftp.pd

A peptide trivalent arsenical inhibits tumor angiogenesis by perturbing mitochondrial function in angiogenic endothelial cells

AbstractMitochondria are the powerhouse of the cell and their disruption leads to cell death. We have used a peptide trivalent arsenical, 4-(N-(S-glutathionylacetyl)amino) phenylarsenoxide (GSAO), to inactivate the adenine nucleotide translocator (ANT) that exchanges matrix ATP for cytosolic ADP across the inner mitochondrial membrane and is the key component of the mitochondrial permeability transition pore (MPTP). GSAO triggered Ca2+-dependent MPTP opening by crosslinking Cys160 and Cys257 of ANT. GSAO treatment caused a concentration-dependent increase in superoxide levels, ATP depletion, mitochondrial depolarization, and apoptosis in proliferating, but not growth-quiescent, endothelial cells. Endothelial cell proliferation drives new blood vessel formation, or angiogenesis. GSAO inhibited angiogenesis in the chick chorioallantoic membrane and in solid tumors in mice. Consequently, GSAO inhibited tumor growth in mice with no apparent toxicity at efficacious doses

The mediating roles of workplace support and ethical work environment in associations between leadership and moral distress: a longitudinal study of Canadian health care workers during the COVID-19 pandemic

IntroductionThe COVID-19 pandemic has resulted in heightened moral distress among health care workers (HCWs) worldwide. Past research has shown that effective leadership may mitigate potential for the development of moral distress. However, no research to date has considered the mechanisms by which leadership might have an influence on moral distress. We sought to evaluate longitudinally whether Canadian HCWs’ perceptions of workplace support and ethical work environment would mediate associations between leadership and moral distress.MethodsA total of 239 French- and English-speaking Canadian HCWs employed during the COVID-19 pandemic were recruited to participate in a longitudinal online survey. Participants completed measures of organizational and supervisory leadership at baseline and follow-up assessments of workplace support, perceptions of an ethical work environment, and moral distress.ResultsAssociations between both organizational and supervisory leadership and moral distress were fully mediated by workplace supports and perceptions of an ethical work environment.DiscussionTo ensure HCW well-being and quality of care, it is important to ensure that HCWs are provided with adequate workplace supports, including manageable work hours, social support, and recognition for efforts, as well as an ethical workplace environment

UV Absorption Lines from High-Velocity Gas in the Vela Supernova Remnant: New insights from STIS Echelle Observations of HD72089

The star HD72089 is located behind the Vela supernova remnant and shows a complex array of high and low velocity interstellar absorption features arising from shocked clouds. A spectrum of this star was recorded over the wavelength range 1196.4 to 1397.2 Angstroms at a resolving power lambda/Delta lambda = 110,000 and signal-to-noise ratio of 32 by STIS on the Hubble Space Telescope. We have identified 7 narrow components of C I and have measured their relative populations in excited fine-structure levels. Broader features at heliocentric velocities ranging from -70 to +130 km/s are seen in C II, N I, O I, Si II, S II and Ni II. In the high-velocity components, the unusually low abundances of N I and O I, relative to S II and Si II, suggest that these elements may be preferentially ionized to higher stages by radiation from hot gas immediately behind the shock fronts.Comment: 11 pages, 2 figures, Latex. Submitted for the special HST ERO issue of the Astrophysical Journal Letter

The roles of personality and resilience in associations between combat experiences and posttraumatic stress disorder among Canadian Armed Forces Veterans

Canadian Armed Forces (CAF) Veterans encounter unique challenges associated with their service. Exposure to service-related traumatic events places them at risk for developing adverse mental health outcomes, including posttraumatic stress disorder (PTSD). Our research aimed to assess whether the HEXACO personality model and resilience impacted associations between combat experiences and PTSD symptomatology in CAF Veterans in the past month. We recruited a sample of 245 CAF Veterans (81 % men; Mage = 48.47, SDage = 10.34) to complete a battery of questionnaires. PTSD symptoms were significantly associated with more combat experience, lower resilience, lower extraversion, higher emotionality, and lower agreeableness. However, personality traits did not moderate the relationship between combat experiences and PTSD symptoms. Overall, this research can be used to enhance researchers\u27 and clinicians\u27 understanding of personality traits as risk and protective factors for PTSD symptoms

The mediating roles of workplace support and ethical work environment in associations between leadership and moral distress:a longitudinal study of Canadian health care workers during the COVID-19 pandemic

Introduction: The COVID-19 pandemic has resulted in heightened moral distress among health care workers (HCWs) worldwide. Past research has shown that effective leadership may mitigate potential for the development of moral distress. However, no research to date has considered the mechanisms by which leadership might have an influence on moral distress. We sought to evaluate longitudinally whether Canadian HCWs’ perceptions of workplace support and ethical work environment would mediate associations between leadership and moral distress.Methods: A total of 239 French- and English-speaking Canadian HCWs employed during the COVID-19 pandemic were recruited to participate in a longitudinal online survey. Participants completed measures of organizational and supervisory leadership at baseline and follow-up assessments of workplace support, perceptions of an ethical work environment, and moral distress.Results: Associations between both organizational and supervisory leadership and moral distress were fully mediated by workplace supports and perceptions of an ethical work environment.Discussion: To ensure HCW well-being and quality of care, it is important to ensure that HCWs are provided with adequate workplace supports, including manageable work hours, social support, and recognition for efforts, as well as an ethical workplace environment

Superficial simplicity of the 2010 El Mayor–Cucapah earthquake of Baja California in Mexico

The geometry of faults is usually thought to be more complicated at the surface than at depth and to control the initiation, propagation and arrest of seismic ruptures. The fault system that runs from southern California into Mexico is a simple strike-slip boundary: the west side of California and Mexico moves northwards with respect to the east. However, the M_w 7.2 2010 El Mayor–Cucapah earthquake on this fault system produced a pattern of seismic waves that indicates a far more complex source than slip on a planar strike-slip fault. Here we use geodetic, remote-sensing and seismological data to reconstruct the fault geometry and history of slip during this earthquake. We find that the earthquake produced a straight 120-km-long fault trace that cut through the Cucapah mountain range and across the Colorado River delta. However, at depth, the fault is made up of two different segments connected by a small extensional fault. Both segments strike N130° E, but dip in opposite directions. The earthquake was initiated on the connecting extensional fault and 15 s later ruptured the two main segments with dominantly strike-slip motion. We show that complexities in the fault geometry at depth explain well the complex pattern of radiated seismic waves. We conclude that the location and detailed characteristics of the earthquake could not have been anticipated on the basis of observations of surface geology alone

Toward Open and Reproducible Environmental Modeling by Integrating Online Data Repositories, Computational Environments, and Model Application Programming Interfaces

Cyberinfrastructure needs to be advanced to enable open and reproducible environmental modeling research. Recent efforts toward this goal have focused on advancing online repositories for data and model sharing, online computational environments along with containerization technology and notebooks for capturing reproducible computational studies, and Application Programming Interfaces (APIs) for simulation models to foster intuitive programmatic control. The objective of this research is to show how these efforts can be integrated to support reproducible environmental modeling. We present first the high-level concept and general approach for integrating these three components. We then present one possible implementation that integrates HydroShare (an online repository), CUAHSI JupyterHub and CyberGIS-Jupyter for Water (computational environments), and pySUMMA (a model API) to support open and reproducible hydrologic modeling. We apply the example implementation for a hydrologic modeling use case to demonstrate how the approach can advance reproducible environmental modeling through the seamless integration of cyberinfrastructure services