The Energy Problem: Choices for an Uncertain Future

Analyzes discussions from National Issues Forums to assess how the public defines the energy problem, what it sees as the causes and solutions, where confusion and tensions over the energy problem lie, and why there is no consensus on how to resolve it

Advanced photovoltaic solar array design assessment

The Advanced Photovoltaic Solar Array (APSA) program seeks to bring to flight readiness a solar array that effectively doubles the specific power of the Solar Array Flight Experiment/Solar Electric Propulsion (SAFE/SEP) design that was successfully demonstrated during the Shuttle 41-D mission. APSA is a critical intermediate milestone in the effort to demonstrate solar array technologies capable of 300 W/kg and 300 W/square m at beginning of life (BOL). It is not unreasonable to anticipate the development of solar array designs capable of 300 W/kg at BOL for operational power levels approx. greater than 25 kW sub e. It is also quite reasonable to expect that high performance solar arrays capable of providing at least 200 W/kg at end of life for most orbits now being considered by mission planners will be realized in the next decade

Free Primary Education in Kenya: An Impact Evaluation Using Propensity Score Methods

This paper attempts to evaluate the impact of the free primary education programme in Kenya, which is based on the premise that government intervention can lead to enhanced access to education especially by children from poor parental backgrounds. Primary education system in Kenya has been characterised by high wastage in form of low enrolment, high dropout rates, grade repetition as well as poor transition from primary to secondary schools. This scenario was attributed to high cost of primary education. To reverse these poor trends in educational achievements, the government initiated free primary education programme in January 2003. This paper therefore analyzes the impact of the FPE programme using panel data. Results indicate primary school enrolment rate has improved especially for children hailing from higher income categories; an indication that factors that prevent children from poor backgrounds from attending primary school go beyond the inability to pay school fees. Grade progression in primary schools has slightly dwindled. The results also indicate that there still exist constraints hindering children from poorer households from transiting to secondary school. The free primary education programme was found to be progressive, with the relatively poorer households drawing more benefits from the subsidy.Primary education, Programme evaluation, Propensity score, benefit incidence analysis, Kenya

Developing a structural brand equity model for cultural destinations

Purpose – This paper aims to investigate the structural relationships between the brand equity (BE) dimensions, when the fifth dimension of cultural brand assets is incorporated. The paper seeks to establish and validate a five-dimensional BE measure for cultural urban destination, by comparing findings in two destinations. Design/methodology/approach – The structural model was tested from the perspective of 399 international tourists visiting Athens. Confirmatory factor analysis and structural equation modeling analysis are used to test and validate an integrated BE model for cultural destinations. Findings are compared with respective ones in the case of Rome. Findings – Findings reveal the significance of cultural brand assets for the BE of cultural urban destinations. Further, the study provides useful insight into the theory of reasoned action by investigating the structural relationships developed between BE dimensions and their impact on loyalty. Research limitations/implications – The study argues that the summative valence of associations, as described in the theory of reasoned action, can be applied in the case of a cultural destination as well. Research directions, including additional place brand dimensions, additional destinations, stakeholders groups or multi-group analysis, are advised to verify and generalise the application of the five-dimensional BE model. Practical implications – Findings reveal those cultural brand assets which can help practitioners build up coherent and successful proprietary brand assets. Quality is a necessary pre-requisite to enhance loyalty. In the case of Athens, associations influence only indirect loyalty through their impact on quality. Originality/value – This study offers to the limited literature concerning structural relationships developed among all five BE dimensions and consumer decision-making models in a tourism context. Moreover, the study contributes to the under-researched dimension of cultural brand assets.</p

Assessing destination brand equity: An integrated approach

Commonly, when referring to destination brand equity, four dimensions are taken into consideration: awareness, image, quality and loyalty. Building on product and corporate brand equity and the definition of destination branding, the present paper includes a marketing approach towards developing a structural model incorporating a fifth dimension; that of cultural brand assets. The proposed model, focused on cultural urban destinations, was tested from the perspective of international tourists visiting Rome. Findings indicate that the five dimensions are interrelated and important for the customers' evaluation of a cultural destination. Consistent with place and destination branding literature, the significance of specific cultural brand assets is emphasized. The study provides practitioners with a better understanding of the dimensions which may lead to favorable brand evaluations. Finally, it describes the structural relationships which are developed between assets, awareness, associations and quality, and links them with the intention to re-visit and recommend as outcomes leading to destination loyalty

Predator functional responses and the biocontrol of aphids and mites

Biocontrol with predators is a key tool for controlling agricultural pests and preserving the productive efficiency of crops. Determining which predators to use for biocontrol often involves measuring their functional response—the relationship between foraging rate and prey abundance, yet comparisons of functional responses across predators are complicated by differences in experimental procedures. Here we use a compilation of functional responses standardized for time and space units to illustrate key sources of variation in functional responses for predators being tested for control of aphids and mites. Our results show that arena size (as a proxy for habitat structure) is a crucial predictor of predator performance, indicating that assessments of functional responses on the crops of interest may be necessary for accurate comparisons. Our results also suggest that larger predators may generally be more efficient, and that warming linked to climate change could make biocontrol using predators more effective when pests are abundant

Third-Wave Feminist Linguistics: A Discursive Approach to Female Specific Interests in Maya Angelou’s Gather Together in My Name

This paper used the Discursive Approach to Language and Gender studies to examine all-female linguistic choices and how linguistic variation amongst female interlocutors is a representation of each female’s individual and cultural identity and feminist ideology. The study revealed that linguistic variability abounds between individual women as well as amongst women as a social group and further showed that each individual woman’s talk-style reflects her linguistic idiolect and translates to her individual feminist ideology. The study also showed that the interactional style of Black American women and the use of their peculiar Black vernacular English called Ebonics identify them as a separate socio-cultural group with a separate feminist ideology different from that of their white counterparts. The study concluded that individual women’s linguistic choices and socio-cultural background militates against a universal feminist ideology but rather makes feminism multicultural / pluralist in theory and practice.Keywords: Discursive approach, Ebonics, Multicultural, Pluralist, Third-wave feminist linguistic

Functional responses are maximized at intermediate temperatures

Functional responses describe how consumer foraging rates change with resource density. Despite extensive research looking at the factors underlying foraging interactions, there remains ongoing controversy about how temperature and body size control the functional response parameters space clearance (or attack) rate and handling time. Here, we investigate the effects of temperature, consumer mass, and resource mass using the largest compilation of functional responses yet assembled. This compilation contains 2,083 functional response curves covering a wide range of foragers and prey types, environmental conditions, and habitats. After accounting for experimental arena size, dimensionality of the foraging interaction, and consumer taxon, we find that both space clearance rate and handling time are optimized at intermediate temperatures (a unimodal rather than monotonic response), suggesting that the response to global climate change depends on the location of the consumer’s current temperature relative to the optimum. We further confirm that functional responses are higher and steeper for large consumers and small resources, and models using consumer and resource masses separately outperformed models using consumer:resource mass ratios, suggesting that consumer and resource body mass act independently to set interaction strengths. Lastly, we show that the extent to which foraging is affected by temperature or mass depends on the taxonomic identity of the consumer and the dimensionality of the consumer–resource interaction. We thus argue that although overall body size and temperature effects can be identified, they are not universal, and therefore food web and community modeling approaches could be improved by considering taxonomic identity along with body size and unimodal temperature effects

Estimating large-scale general linear and seemingly unrelated regressions models after deleting observations

A new numerical method to solve the downdating problem (and variants thereof), namely removing the effect of some observations from the generalized least squares (GLS) estimator of the general linear model (GLM) after it has been estimated, is extensively investigated. It is verified that the solution of the downdated least squares problem can be obtained from the estimation of an equivalent GLM, where the original model is updated with the imaginary deleted observations. This updated GLM has a non positive definite dispersion matrix which comprises complex covariance values and it is proved herein to yield the same normal equations as the downdated model. Additionally, the problem of deleting observations from the seemingly unrelated regressions model is addressed, demonstrating the direct applicability of this method to other multivariate linear models. The algorithms which implement the novel downdating method utilize efficiently the previous computations from the estimation of the original model. As a result, the computational cost is significantly reduced. This shows the great usability potential of the downdating method in computationally intensive problems. The downdating algorithms have been applied to real and synthetic data to illustrate their efficiency

A recursive three-stage least squares method for large-scale systems of simultaneous equations

A new numerical method is proposed that uses the QR decomposition (and its variants) to derive recursively the three-stage least squares (3SLS) estimator of large-scale simultaneous equations models (SEM). The 3SLS estimator is obtained sequentially, once the underlying model is modified, by adding or deleting rows of data. A new theoretical pseudo SEM is developed which has a non positive definite dispersion matrix and is proved to yield the 3SLS estimator that would be derived if the modified SEM was estimated afresh. In addition, the computation of the iterative 3SLS estimator of the updated observations SEM is considered. The new recursive method utilizes efficiently previous computations, exploits sparsity in the pseudo SEM and uses as main computational tool orthogonal and hyperbolic matrix factorizations. This allows the estimation of large-scale SEMs which previously could have been considered computationally infeasible to tackle. Numerical trials have confirmed the effectiveness of the new estimation procedures. The new method is illustrated through a macroeconomic application