The utility of energy storage to improve the economics of wind–diesel power plants in Canada

Wind energy systems have been considered for Canada's remote communities in order to reduce their costs and dependence on diesel fuel to generate electricity. Given the high capital costs, low-penetration wind–diesel systems have been typically found not to be economic. High-penetration wind–diesel systems have the benefit of increased economies of scale, and displacing significant amounts of diesel fuel, but have the disadvantage of not being able to capture all of the electricity that is generated when the wind turbines operate at rated capacity.Two representative models of typical remote Canadian communities were created using HOMER, an NREL micro-power simulator to model how a generic energy storage system could help improve the economics of a high-penetration wind–diesel system. Key variables that affect the optimum system are average annual wind speed, cost of diesel fuel, installed cost of storage and a storage systems overall efficiency. At an avoided cost of diesel fuel of 0.30 $Cdn/kWh and current installed costs, wind generators are suitable in remote Canadian communities only when an average annual wind speed of at least 6.0 m/s is present. Wind energy storage systems become viable to consider when average annual wind speeds approach 7.0 m/s, if the installed cost of the storage system is less than 1000 $Cdn/kW and it is capable of achieving at least a 75% overall energy conversion efficiency. In such cases, energy storage system can enable an additional 50% of electricity from wind turbines to be delivered.     

Is diurnal variation of mood associated with parasympathetic activity?

70 patients older than 50 years (mean age: 60.2 years) underwent a CD-spondylodesis from 1987 to 1991 for degenerative changes of the lumbar spine, and were followed for 2 years. 88.2% improved, but only 47.1% showed a good-to-excellent result. Patients with fair and poor outcomes had had significantly more operations on the lumbar spine (p < 0.001), had a greater extent of preoperative lumbar kyphosis (p < 0.05), motor weakness (p < 0.05), had less vertebral slips (p < 0.01), had less posterior distraction postoperatively (p < 0.001), and had a greater extent of postoperative motor weakness compared to patients with good-to-excellent outcomes. Age, sex, duration of back/leg pain, taking of analgetic drugs, preoperative pain status, profession, range of walking, time of operation, number of fused segments, blood loss, blood transfusion, postoperative profile of the spine did not show any significant influence upon clinical results. Already at 6-months-follow-up there was significant difference of the clinical outcome (p < 0.001), making improvement of a then fair or poor result unlikely.     

Combining ion mobility spectrometry, mass spectrometry, and photoelectron spectroscopy in a high-transmission instrument

We have developed a novel instrument that combines ion mobility spectrometry, mass spectro-metry, and photoelectron spectroscopy. The instrument couples an electrospray ion source, a high-transmission ion mobility cell based on ion funnels, a quadrupole mass filter, and a time-of-flight (magnetic bottle) photoelectron spectrometer operated with a pulsed detachment laser. We show that the instrument can resolve highly structured anion arrival time distributions and at the same time provide corresponding photoelectron spectra-using the DNA oligonucleotide ion [dC(6) - 5H](5-) as a test case. For this multianion we find at least four different, noninterconverting isomers (conformers) simultaneously present in the gas phase at room temperature. For each of these we record well-resolved and remarkably different photoelectron spectra at each of three different detachment laser wavelengths. Two-dimensional ion mobility/electron binding energy plots can be acquired with an automated data collection procedure. We expect that this kind of instrument will significantly improve the capabilities for structure determination of (bio)molecular anions in the gas phase.     

Ca2+-dependent structural changes in C-type mannose-binding proteins

C-type animal lectins are a diverse family of proteins which mediate cell-surface carbohydrate-recognition events through a conserved carbohydrate-recognition domain (CRD). Most members of this family possess a carbohydrate-binding activity that depends strictly on the binding of Ca2+ at two sites, designated 1 and 2, in the CRD. The structural transitions associated with Ca2+ binding in C-type lectins have been investigated by determining high-resolution crystal structures of rat serum mannose-binding protein (MBP) bound to one Ho3+ in place of Ca2+, and the apo form of rat liver MBP. The removal of Ca2+ does not affect the core structure of the CRD, but dramatic conformational changes occur in the loops. The most significant structural change in the absence of Ca2+ is the isomerization of a cis-peptide bond preceding a conserved proline residue in Ca2+ site 2. This bond adopts the cis conformation in all Ca2+-bound structures, whereas both cis and trans conformations are observed in the absence of Ca2+. The pattern of structural changes in the three loops that interact with Ca2+ is dictated in large part by the conformation of the prolyl peptide bond. The highly conserved nature of Ca2+ site 2 suggests that the transitions observed in MBPs are general features of Ca2+ binding in C-type lectins.     

Preparations for Y2K: Revisiting the Behavioral Component of the Third-Person Effect

Although the behavioral component was an integral part of the original formulation of the third-person effect hypothesis, little research has examined the impact of biased media effect perceptions on behaviors that assume others have already been affected. The present study examines how third-person perceptions (the belief that other people are particularly vulnerable to media messages) contributed to intentions to prepare for problems stemming from Y2K, also known as the "millennium bug." Analyses using data from 2 regional probability samples taken in late 1999 show that perceptions about the potential effects of news messages influenced public anxiety about the Y2K situation and beliefs that other people would overprepare for the new year. These 2 variables, in turn, predicted intentions to stockpile supplies of food, water, gasoline, and cash. The article discusses the implications of these findings for understanding the relationship between perceptions of media effects and an extended range of behaviors.