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The focus of this book is the interactions between energy, ecology, and climate change, as well as a few of the responses of humanity to these interactions. It is not a textbook, but a series of chapters discussing subtopics in which the authors were interested and wished to write about. The basic material is cutting-edge science; technical journal articles published within the last year, selected for their relevance and interest. Each author selected eight or so technical papers representing his or her view of the most interesting current research in the field, and wrote summaries of them in a journalistic style that is free of scientific jargon and understandable by lay readers. This is the sort of science writing that you might encounter in the New York Times, but concentrated in a way intended to give as broad an overview of the chapter topics as possible. None of this research will appear in textbooks for a few years, so there are not many ways that readers without access to a university library can get access to this information.
This book is intended be browsed—choose a chapter topic you like and read the individual sections in any order; each is intended to be largely stand-alone. Reading all of them will give you considerable insight into what climate scientists concerned with energy, ecology, and human effects are up to, and the challenges they face in understanding one of the most disruptive—if not very rapid—event in human history; anthropogenic climate change. The Table of Contents follows: Continue reading →
The number of reported human tularemia cases will steadily increase from 2010 to 2100 in the five high-endemic counties of Dalarna, Gävleborg, Norrbotten, Värmland, and Örebro. The predicted increase in the incidences of human tularemia has been linked to the steadily warmer climate of Sweden enabling certain parasites to proliferate. The parasites that spread the bacterium Francisella tularensis include ticks, mosquitoes, fleas, horse flies, and deerflies. Though the level of precipitation was predicted to remain stable and constant throughout the 2010–2100 periods, indicating that the increase in parasites is not due to increased rainfall, the rate of tularemia still increased as the climate became warmer (Rydén et al. 2009). The high localization of tularemia, the population patterns of its vectors and its incidences on the local population will need to be further researched in order to understand the reasons why increased tularemia epidemics correlate with increased temperature. Kevon White
Rydén, P., Sjöstedt, A., Johansson, A., 2009. Effects of climate change on tularaemia disease activity in Sweden. Citation: Global Health Action. DOI: 10.3402/gha.v2i0.2063.
Patrick Rydén and colleagues from Umeå University analyzed data about human tularemia outbreaks in Sweden from 1997–2008. A 140-year model for simulation data was constructed and performed. Scenario data was taken using a climate model RCA3 and the IPCC Special Report on Emissions data. The data were arranged into 50 x 50 km square regions. Empirical data of disease onset from 379 individuals during 1981–2007 were collected from Dalarna County and used to determine the temperature and time parameters of human tularemia epidemics. The monthly average values were calculated for temperature and precipitation using the 50 x 50 km square regions. The duration of a tularemia epidemic was determined using the mean temperatures from May to October and time plots from the first and last human tularemia case for each year, region, and local outbreak area.
Investigations on the five high tularemia-endemic areas showed that the incidences of human tularemia from 1997–2008 ranged from 40.1 to 81.1% of the total tularemia incidences in Sweden. All five counties contain 14.61% of the Swedish population at 1,352,558 human inhabitants. The number of incidences during the 1997–2008 range from 0 in the Värmland and Örebro counties in 1997 to 216 in Dalarna County in 2003. However, the distribution in the five counties was uneven, mainly due to the high localization of the disease. The tularemia prediction model indicated that the summer conditions will last longer due to an increase in temperatures by 2° C during 2010–2100. The precipitation was stable throughout the period and did not increase significantly. The duration of the temperate sensitive outbreaks will vary from 3.5 weeks in Norrbotten to 6.6 weeks in Värmland during 2010–2100. An exact relationship between the temperature and the rate of transmission has not been clearly documented; however, because precipitation is stable throughout the 2010–2100 periods then the amount of rainfall is insignificant to the rate of transmission. More analyses will have to be taken in order to determine the exact causes of the disease’s restrictive locality, the vector populations that house the bacterium Francisella tularensis, and the responses of the flora, fauna, and transmission rates to increased
Leptospermum honey is effective against various types of antibiotic resistant bacteria including Staphylococcus aureus, (MRSA), Acinetobacter calcoaceticus, and Escherichia coli. Additionally the bacteria show no resistance to Leptospermum honey even after repeated exposure (Blair et al. 2009). Leptospermum honey was found to be effective at low concentrations from 4% to 14.8%. It acts differently from other antimicrobial agents by providing moisture, sugars, and hydrogen peroxide as well as an unprecedented number of compounds that have yet to be fully researched. As there are few scientific studies that support the use of honey in wound treatment, more will be needed to understand all of the effects of using honey to treat or prevent infections caused by antibiotic resistant diseases. Kevon White
Blair, E., Cokcetin, N., Harry E., Carter D., 2009. The unusual antibacterial activity of medical-grade Leptospermum honey: antibacterial spectrum, resistance and transcriptome analysis. Eur J Clin Microbiol Infect Dis 28, 1199–1208
S.E. Blair and Colleagues from the University of Sydney and the University of Technology in Sydney conducted several tests using four different types of honey: Medihoney®, Leptospermum honey, Lucerne Blueweed honey, and a controlled artificial honey made from several sugars. The Medihoney® was added slowly to various agar plates containing 13 different types of infectious bacteria. The MIC was then recorded from the results. A marcodilution method test was done later in which all four honeys were diluted with water and was slowly added to the bacteria to determine the MBC of the bacterium. The results of the different honeys were compared with those of Oxcallin, Tetracycline, and Ciprofloxacin. The different honeys along with the three antibiotic medicines were tested repeatedly over the bacterial strains to determine resistance capabilities. Lastly, a macroarray analysis was performed on 6% honey solutions of Medihoney® and the inactive Leptospermum honey. A culture of E. coli was then combined with the honeys to determine the gene expression of the two samples.
The Medihoney® inhibited the growth of bacteria significantly compared to the artificial control honey. The MIC for the Medihoney® ranged from 4%–16% while the artificial honey’s MIC ranged from 20% to beyond 25%. Of the bacteria in the first experiment, MRSA had the least resistance to honey, but it resisted the artificial honey by nearly five times that value. Though the honey is less effective at first, the bacteria do not seem to develop any resistance to it, even after being subjected to repeated trials of honey. When compared to Oxacillin, Tetracyclinen and Ciprofloxacin the percentage of honey needed to inhibit bacterial growth initially was much higher; however, unlike the previous three medicines, the honey does not allow the bacteria to develop a resistance to it. The expression of several E.coli genes when mixed with honey indicates that it may cause a significant change in the protein and binding structures of the bacteria. One-hundred-twenty-four genes were found to be upregulated or downregulated by the presence of honey. Of these genes, most were associated with stress responses in the bacteria. This indicates that honey may have an effect on the bacterial gene sequence and may interfere with protein synthesis. Another suggestion by Blair et al. is that the complex nature of the honey and a yet discovered compound could account for its effectiveness in eliminating antibiotic resistant bacteria. Leptospermum honey has demonstrated the ability to treat an unusually broad number of antibiotic resistant bacteria, and most importantly it is resilient against these strains. Thus its use in western medicine will be important in combating increasingly deadly strains of evolving bacteria.