7,070 research outputs found
The Economics of Wind Power: Destabilizing an Electricity Grid with Renewable Power
In this paper, we examine the impact policy choices, including a carbon tax, on the optimal allocation of power across different generation sources and on future investments in generating facilities. The focus in on the Alberta power grid as it is heavily dependent on fossil fuels and has only limited ties to other power grids, although the model could be extended to a larger and even multiple grids. Results indicate that, as wind penetrates the extant generating mix characterizing the grid, cost savings and emission reductions do not decline linearly, but at a decreasing rate. However, if flexibility is allowed then, as the carbon tax increases to 170/tCO2. The associated high capital costs of new generating facilities may thus not be an ideal use of funds for addressing climate change.Economics of wind power, grid system modeling, operations research, carbon taxes and coal power plants
The effects of spacecraft environments on some hydrolytic enzyme patterns in bacteria
The effects of space flight on the production and characteristics of proteolytic enzymes are studied for a number of bacterial species isolated from crew members and spacecraft. Enzymatic make-up and cultural characteristics of bacteria isolated from spacecraft crew members are determined. The organism Aeromonas proteolytica and the proteolytic enzymes which it produces are used as models for future spacecraft experiments
The Potential for Wind Energy Meeting Electricity Needs on Vancouver Island
In this paper, an in-depth analysis of power supply and demand on Vancouver Island is used to provide information about the optimal allocation of power across âgeneratingâ sources and to investigate the economics of wind generation and penetrability into the Island grid. The methodology developed can be extended to a region much larger than Vancouver Island. Results from the model indicate that Vancouver Island could experience blackouts in the near future unless greater name-plate capacity is developed. While wind-generated energy has the ability to contribute to the Islandâs power needs, the problem with wind power is its intermittency. The results indicate that wind power may not be able to prevent shortfalls, regardless of the overall name-plate capacity of the wind turbines. Further, costs of reducing CO2 emissions using wind power are unacceptably large, perhaps more than $100 per t CO2, although this might be attributable to the mix of power sources making up the Islandâs grid.Economics of wind power, grid system modeling, operations research
Depression and anxiety in prostate cancer: a systematic review and meta-analysis of prevalence rates
ObjectivesTo systematically review the literature pertaining to the prevalence of depression and anxiety in patients with prostate cancer as a function of treatment stage.DesignSystematic review and meta-analysis.Participants4494 patients with prostate cancer from primary research investigations.Primary outcome measureThe prevalence of clinical depression and anxiety in patients with prostate cancer as a function of treatment stage.ResultsWe identified 27 full journal articles that met the inclusion criteria for entry into the meta-analysis resulting in a pooled sample size of 4494 patients. The meta-analysis of prevalence rates identified pretreatment, on-treatment and post-treatment depression prevalences of 17.27% (95% CI 15.06% to 19.72%), 14.70% (95% CI 11.92% to 17.99%) and 18.44% (95% CI 15.18% to 22.22%), respectively. Pretreatment, on-treatment and post-treatment anxiety prevalences were 27.04% (95% CI 24.26% to 30.01%), 15.09% (95% CI 12.15% to 18.60%) and 18.49% (95% CI 13.81% to 24.31%), respectively.ConclusionsOur findings suggest that the prevalence of depression and anxiety in men with prostate cancer, across the treatment spectrum, is relatively high. In light of the growing emphasis placed on cancer survivorship, we consider that further research within this area is warranted to ensure that psychological distress in patients with prostate cancer is not underdiagnosed and undertreated
Some bog denizens
Tucked away in the bogs and swamps of Wisconsin, and in similar habitats throughout the world, thrive a myriad of unicellular plants known as Desmids. They are among the most aesthetic of all microorganisms and vie with the glassywalled Diatoms as Jewel Plants. If it were not for the inquisitive biologist and the students of the microscopic cosmos, Desmids well might exist unnoticed. For although they have highly intriguing biological features they play no role in water spoilage problems, nor are they important in the food cycle of aquatic animals. Hence they do not attract attention nor invite the condemnations that are directed toward some other groups of algae such as the blue-greens
A Brief Summary of Work on Iowa Algae
My part in the taxonomic survey of the algal flora of Iowa began in the fall of 1924. It may be of interest at this time to summarize briefly the work done on the algae of Iowa, including my unpublished notes
Preregistration house officers in general practice: review of evidence
OBJECTIVES: To examine the strengths and weaknesses
of the national and local schemes for preregistration
house officers to spend four months in general
practice, to identify any added value from such
placements, and to examine the impact on career
choices.
DESIGN: Review of all studies that reported on
placements of preregistration house officers in
general practice.
SETTING: 19 accounts of preregistration house officersâ
experience in general practice, ranging from single
case reports to a national evaluation study, in a variety
of locations in Scotland and England.
PARTICIPANTS: Views of 180 preregistration house
officers, 45 general practitioner trainers, and 105
consultant trainers.
MAIN OUTCOME MEASURES: Main findings or themes
weighted according to number of studies reporting
them and weighted for sample size.
RESULTS: The studies were unanimous about the
educational benefits of the placements. The
additional learning included communication skills,
social and psychological factors in illness, patient
centred consultations, broadening of knowledge base,
and dealing with uncertainty about diagnosis and
referral.
CONCLUSIONS: Despite the reported benefits and
recommendations of the scheme, it is not expanding.
General practitioner trainers reported additional
supervision that was unremunerated. The reforms of
the senior house officer grade may resolve this
problem by offering the placements to senior house
officers, who require less supervision
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