On the interaction of wind energy with climate and weather

This study focuses on the interaction of large-scale wind energy with the atmosphere; namely, the impact that a substantial development of the wind resource may have on climate and weather as well as the impact that anthropogenic global warming (AGW) may have on the amount of available energy in the wind. A large downstream climate response to wind turbines distributed throughout the central United States is shown in model results from the Community Atmosphere Model (CAM). The mean response takes the form of a stationary Rossby wave. Furthermore, a case study is shown where the wind turbines altered a storm system over the North Atlantic. The resulting magnitude of the anomalous 500 hPa geopotential height field is comparable to the range of forecast uncertainty, which indicates that impacts induced in weather systems may be forecastable Building on this work, a thorough examination of wind farm and atmospheric parameters, including wind farm size, position, and parameterization as well as atmospheric static stability and jet strength is carried out using an idealized version of the Weather Research and Forecasting (WRF) model. Downstream impacts were found to grow in magnitude as wind farm size and the value of damping used to parameterize the wind turbines was increased. Altering the position of the wind farm with respect to the westerlies and synoptic disturbances revealed that the interaction between baroclinic instabilities and the wind farm enables downstream propagation and growth of the wind farm impacts. However, far downstream impacts were observed to be somewhat independent of the wind farm position, i.e., similar downstream effects were noted for model runs initialized with wind farms 20° of longitude from each other. By increasing atmospheric static stability, a fast saturation of wind farm-induced anomalies was observed throughout the atmosphere. This observation is surprising in light of the increased phasing between surface and upper atmospheric anomalies when static stability is low. Anomalies were able to propagate farther downstream over a shorter period of time when jet strength was increased. To study projected climate change impacts on the wind resource, data from the third phase of the Coupled Model Intercomparison Project (CMIP3) and the North American Regional Climate Change Assessment Project (NARCCAP) were studied. The results are dominated by substantial intermodel variability; however, many of the models project an increase in wind speeds and energy over the central United States. This increase in wind energy is related to an increase in low-frequency, high-speed transient wind speeds, which have a high power density due to the cubic relationship between wind speed and power

Expectations in the field of the Internet and health: an analysis of claims about social networking sites in clinical literature

This article adopts a critical sociological perspective to examine the expectations surrounding the uses of social networking sites (SNSs) articulated in the domain of clinical literature. This emerging body of articles and commentaries responds to the recent significant growth in SNS use, and constitutes a venue in which the meanings of SNSs and their relation to health are negotiated. Our analysis indicates how clinical writing configures the role of SNSs in health care through a range of metaphorical constructions that frame SNSs as a tool, a conduit for information and a traversable space. The use of such metaphors serves not only to describe the new affordances offered by SNSs but also posits distinct lay and professional practices, while reviving a range of celebratory claims about the Internet and health critiqued in sociological literature. These metaphorical descriptions characterise SNS content as essentially controllable by autonomous users while reiterating existing arguments that e-health is both inherently empowering and risky. Our analysis calls for a close attention to these understandings of SNSs as they have the potential to shape future online initiatives, most notably by anticipating successful professional interventions while marginalising the factors that influence users’ online and offline practices and contexts

Toward Defining Literacy

Literacy is a topic much on the public\u27s mind these days. It is one of those subjects on which all laypersons think they are experts. When it comes time, however, to establish measures of illiteracy rates or to set policies, it becomes apparent that we know less than we thought we did. It is small comfort to know that specialists also have their differences

Pricing in C2C Sharing Platforms

Sharing platforms such as zilok.com enable sharing of durable goods among consumers, and seek to maximize profits by charging transaction-based platform fees. We develop a model in which consumers who have heterogeneous needs concerning the use of a durable good decide whether to purchase and share (i.e., be a lender) or borrow (i.e., be a borrower), and a monopoly sharing platform determines the platform fees. We find, first, that consumers with greater need to use a durable good purchase and share, and that consumers with lesser need borrow. Second, sharing platforms maximize profits only if the supply of a durable good matches demand—that is, the market must clear in order for platform fees to be profit maximizing. Third, the market-clearing condition requires lender and borrower fees are classic strategic complements. Fourth, to maintain the market-clearing condition, sharing platforms have to increase their lender fee or decrease their borrower fee in response to increases in the sharing price, increases in usage capacity, and decreases in the purchase price of a durable good, and vice versa. These findings indicate that commonly applied one-sided pricing models in sharing platforms can be improved

A two-minute paper and pencil test of symbolic and nonsymbolic numerical magnitude processing explains variability in primary school children’s arithmetic competence

Recently, there has been a growing emphasis on basic number processing competencies (such as the ability to judge which of two numbers is larger) and their role in predicting individual differences in school-relevant math achievement. Children’s ability to compare both symbolic (e.g. Arabic numerals) and nonsymbolic (e.g. dot arrays) magnitudes has been found to correlate with their math achievement. The available evidence, however, has focused on computerized paradigms, which may not always be suitable for universal, quick application in the classroom. Furthermore, it is currently unclear whether both symbolic and nonsymbolic magnitude comparison are related to children’s performance on tests of arithmetic competence and whether either of these factors relate to arithmetic achievement over and above other factors such as working memory and reading ability. In order to address these outstanding issues, we designed a quick (2 minute) paper-and-pencil tool to assess children’s ability to compare symbolic and nonsymbolic numerical magnitudes and assessed the degree to which performance on this measure explains individual differences in achievement. Children were required to cross out the larger of two, single-digit numerical magnitudes under time constraints. Results from a group of 160 children from grades 1–3 revealed that both symbolic and nonsymbolic number comparison accuracy were related to individual differences in arithmetic achievement. However, only symbolic number comparison performance accounted for unique variance in arithmetic achievement. The theoretical and practical implications of these findings are discussed which include the use of this measure as a possible tool for identifying students at risk for future difficulties in mathematics

Genome Sequence of the Acidophilic Iron Oxidizer Ferrimicrobium acidiphilum Strain T23T

Extremely acidophilic iron-oxidizing bacteria have largely been characterized for the phyla Proteobacteria and Nitrospira. Here, we report the draft genome of an iron-oxidizing and -reducing heterotrophic mesophile of the Actinobacteria, Ferrimicrobium acidiphilum, which was isolated from an abandoned pyrite mine. The genome sequence comprises 3.08 Mb

Genome Sequence of the Acidophilic Ferrous Iron-Oxidizing Isolate Acidithrix ferrooxidans Strain Py-F3, the Proposed Type Strain of the Novel Actinobacterial Genus Acidithrix

Extremely acidophilic iron-oxidizing Gram-positive bacteria comprise species within the phyla Firmicutes and Actinobacteria. Here, we report the 4.02-Mb draft genome of Acidithrix ferrooxidans Py-F3, which was isolated from a stream draining an abandoned copper mine and proposed as the type species of a new genus of Actinobacteria