Influences on bicycle use HUNT, J. D; ABRAHAM, J. E
Transportation (Dordrecht),
07/2007, Letnik:
34, Številka:
4
Journal Article
Recenzirano
A stated preference experiment was performed in Edmonton in Canada to both examine the nature of various influences on bicycle use and obtain ratios among parameter values to be used in the ...development of a larger simulation of household travel behaviour. A total of 1128 questionnaires were completed and returned by current cyclists. Each questionnaire presented a pair of possible bicycle use alternatives and asked which was preferred for travel to a hypothetical all-day meeting or gathering (business or social). Alternatives were described by specifying the amounts of time spent on three different types of cycling facility and whether or not showers and/or secure bicycle parking were available at the destination. Indications of socio-economic character and levels of experience and comfort regarding cycling were also collected. The observations thus obtained were used to estimate the parameter values for a range of different utility functions in logit models representing this choice behaviour. The results indicate, among other things, that time spent cycling in mixed traffic is more onerous than time spent cycling on bike lanes or bike paths; that secure parking is more important than showers at the destination; and that cycling times on roadways tend to become less onerous as level of experience increases. Some of these results are novel and others are consistent with findings regarding bicycle use in work done by others, which is seen to add credence to this work. A review of previous findings concerning influences on cycling behaviour is also included. Copyright Springer Science+Business Media, LLC 2007
Urban centres acquire and accumulate many materials from their hinterland, among these are nutrient elements such as nitrogen (N). The popular North American vision of a peri-urban setting is one ...where urban food production, composting and re-cycling are assumed to limit urban accumulation of nutrients. This study quantifies this assumption using the Lower Fraser Valley (LFV) of British Columbia as an example, ideal because it is surrounded by mountains, ocean and an international border which collectively delimit the peri-urban boundaries. Nitrogen influxes are dominated by livestock feed imports to support dairy and poultry production (18000 tonnes N), followed by human food imports (9210 tonnes N), as well as 5410 tonnes N as fertilizer and 4690 tonnes N in atmospheric deposition. There is a transfer of 6700 tonnes N from agricultural to urban ecosystems displacing food imports, but food production contributes to the N footprint of the LFV. Nitrogen effluxes are dominated by sewage disposal (10400 tonnes N), solid waste disposal (7020 tonnes N) and atmospheric emissions (9460 tonnes N). The total influx is 15 kg N per person, the net influx is 3.1 kg N per person. Per unit land area, these are a total influx of 24 kg N/ha and a net influx of 4.7 kg N/ha. The atmospheric emissions are 4.7 kg N per person and 7.2 kg/ha. The N in soil is mobile and it is assumed soil N is at a steady state concentration, thus the surplus N is lost from the soil, probably by leaching and runoff. The Fraser River is estimated to acquire and transport 5230 tonnes N from the region into the ocean each year, in addition to 10300 tonnes N from sewage outfall. This is coupled with effluxes of phosphorus (estimated previously), and the result probably has an impact on the coastal waters. There is little reuse of imported N and current waste management practices including composting and combustion do little to improve N efficiency.
•The N budget is presented for a physically isolated peri-urban region.•N influxes were dominated by livestock feed to support local dairy and poultry.•N influxes for human food were the next most important.•N effluxes were dominated by sewage, atmospheric emissions and solid waste.•The total annual influx was 15 kg N per person, the net was 3.1 kg N per person.
Three streams of strategic thought, (1) the “adaptive marketing capabilities” works, (2) the “dynamic capabilities” view, and (3) resource-advantage (R-A) theory, are converging on the view that, in ...today's dynamic, hypercompetitive, global economy, strategy must focus on firms' constantly renewing themselves in the marketplace. In turn, these three streams have implications for the controversies over whether strategy's focus should be “outside-in or inside-out” and whether strategy should be static or dynamic. This article addresses the three streams of strategic thought and the two controversies by (1) explicating their nature, (2) showing how strategies related to them have evolved through time, and (3) pointing toward the controversies' resolution. The article argues that all theories of strategy assume a theory of how competition works. In turn, theories of competition are housed within disciplinary research traditions. Therefore, understanding the controversies in contemporary strategy is furthered by understanding both the theories of competition that underlie each strategic approach and their respective research traditions.
•Modern theories of strategy are converging on the view that strategy must focus on firms constantly renewing themselves.•All theories of strategy presume a theory of how competition works.•Business and marketing strategy have been influenced strongly by the neoclassical economics research tradition.•Marketing concept-based strategy and market orientation strategy can provide a strong foundation for marketing strategy.•Resource-advantage (R-A) theory provides a solid theoretical foundation for strategy in today’s hyper-competitive economy.
With growing gas and oil prices, electricity generation based on these fossil fuels is becoming increasingly expensive. Furthermore, the vision of natural gas as a transition fuel is subject to many ...constraints and uncertainties of economic, environmental, and geopolitical nature. Consequently, renewable energies such as solar and wind power are expected to reach new records of installed capacity over the upcoming years. Considering the above, North Africa is one of the regions with the largest renewable resource potential globally. While extensively studied in the literature, these resources remain underutilized. Thus, to contribute to their future successful deployment and integration with the power system, this study presents a spatial and temporal analysis of the nature of solar and wind resources over North Africa from the perspective of energy droughts. Both the frequency and maximal duration of energy droughts are addressed. Both aspects of renewables’ variable nature have been evaluated in the North Atlantic Oscillation (NAO) context. The analysis considers the period between 1960 and 2020 based on hourly reanalysis data (i.e., near-surface shortwave irradiation, wind speed, and air temperature) and the Hurrel NAO index. The findings show an in-phase relationship between solar power and winter NAO index, particularly over the coastal regions in western North Africa and opposite patterns in its eastern part. For wind energy, the connection with NAO has a more zonal pattern, with negative correlations in the north and positive correlations in the south. Solar energy droughts dominate northern Tunisia, Algeria, and Morocco, while wind energy droughts mainly occur in the Atlas Mountains range. On average, solar energy droughts tend not to exceed 2–3 consecutive days, with the longest extending for five days. Wind energy droughts can be as prolonged as 80 days (Atlas Mountains). Hybridizing solar and wind energy reduces the potential for energy droughts significantly. At the same time, the correlation between their occurrence and the NAO index remains low. These findings show the potential for substantial resilience to inter-annual climate variability, which could benefit the future stability of renewables-dominated power systems
The global food system is essential for the health and wellbeing of society, but is also a major cause of environmental damage. Some impacts, such as on climate change, have been the subject of ...intense recent inquiry, but others, such as on air quality, are not as well understood. Here, we systematically synthesize the literature to identify the impacts on ambient PM2.5 (particulate matter with diameter ⩽2.5 μm), which is the strongest contributor to premature mortality from exposure to air pollution. Our analysis indicates that the life-cycle of the global food system (pre-production, production, post-production, consumption and waste management) accounts for 58% of anthropogenic, global emissions of primary PM2.5, 72% of ammonia (NH3), 13% of nitrogen oxides (NO x ), 9% of sulfur dioxide (SO2), and 19% of non-methane volatile organic compounds (NMVOC). These emissions result in at least 890 000 ambient PM2.5-related deaths, which is equivalent to 23% of ambient PM2.5-related deaths reported in the Global Burden of Disease Study 2015. Predominant contributors include livestock and crop production, which contribute >50% of food-related NH3 emissions, and land-use change and waste burning, which contribute up to 95% of food-related primary PM2.5 emissions. These findings are largely underestimated given the paucity of data from the post-production and consumption stages, total underestimates in NH3 emissions, lack of sector-scale analysis of PM2.5-related deaths in South America and Africa, and uncertainties in integrated exposure-response functions. In addition, we identify mitigation opportunities—including shifts in food demand, changes in agricultural practices, the adoption of clean and low-energy technologies, and policy actions—that can facilitate meeting food demand with minimal PM2.5 impacts. Further research is required to resolve sectoral-scale, region-specific contributions to PM2.5-related deaths, and assess the efficiency of mitigation strategies. Our review is positioned to inform stakeholders, including scientists, engineers, policymakers, farmers and the public, of the health impacts of reduced air quality resulting from the global food system.
The aim of this study was to image tibio-femoral movement during flexion in the living knee. Ten loaded male Caucasian knees were initially studied using MRI, and the relative tibio-femoral motions, ...through the full flexion arc in neutral tibial rotation, were measured. On knee flexion from hyperextension to 120°, the lateral femoral condyle moved posteriorly 22
mm. From 120° to full squatting there was another 10
mm of posterior translation, with the lateral femoral condyle appearing almost to sublux posteriorly. The medial femoral condyle demonstrated minimal posterior translation until 120°. Thereafter, it moved 9
mm posteriorly to lie on the superior surface of the medial meniscal posterior horn. Thus, during flexion of the knee to 120°, the femur rotated externally through an angle of 20°. However, on flexion beyond 120°, both femoral condyles moved posteriorly to a similar degree. The second part of this study investigated the effect of gender, side, load and longitudinal rotation. The pattern of relative tibio-femoral movement during knee flexion appears to be independent of gender and side. Femoral external rotation (or tibial internal rotation) occurs with knee flexion under loaded and unloaded conditions, but the magnitude of rotation is greater and occurs earlier on weight bearing. With flexion plus tibial internal rotation, the pattern of movement follows that in neutral. With flexion in tibial external rotation, the lateral femoral condyle adopts a more anterior position relative to the tibia and, particularly in the non-weight bearing knee, much of the femoral external rotation that occurs with flexion is reversed.
Development of radio‐holographic inversion methods that solve for multipath propagation of radio occultation signals in the moist lower troposphere resulted in significant reduction of inversion ...errors of the bending angle and refractivity. Still, inversion errors depend on the length of recorded radio occultation signals, additive noise, and some tunable inversion parameters. These errors have components with nonzero mean (biases) and thus must be understood and quantified for weather and climate applications. In this study a physical explanation of the above mentioned inversion biases is given and their magnitude is evaluated (about 1% in the tropical lower troposphere). Assuming data with 50 Hz sampling rate and a noise level that is typical for the COSMIC GPS radio occultation observations, this magnitude can be considered as the measure of uncertainty of radio holographic inversions below ∼5 km in the moist tropical troposphere.
The subject of branding, customer-brand relationships, brand equity strategies, and branding as a societal institution has become so controversial that an anti-branding movement has become widespread ...across several continents. This movement maintains that branding is not just problematic, but ethically wrong. This article uses the Hunt-Vitell theory of ethics to provide a framework for explicating people's personal moral codes, which in turn, helps us to understand the ethical controversy over branding. The article (1) provides a brief discussion of the nature of branding, (2) identifies major arguments that support the view that branding is morally wrong, (3) overviews the H–V theory of marketing ethics, (4) explicates the H–V theory's “personal moral codes” framework, and (5) shows how it provides a starting point for those who seek to understand, evaluate, and investigate the ethics of branding.
Genetically resistant or susceptible chickens to Marek's disease (MD) have been widely used models to identify the molecular determinants of these phenotypes. However, these prior studies lacked the ...basic identification and understanding of immune cell types that could be translated toward improved MD control. To gain insights into specific immune cell types and their responses to Marek's disease virus (MDV) infection, we used single-cell RNA sequencing (scRNAseq) on splenic cells from MD resistant and susceptible birds. In total, 14,378 cells formed clusters that identified various immune cell types. Lymphocytes, specifically T cell subtypes, were the most abundant with significant proportional changes in some subtypes upon infection. The largest number of differentially expressed genes (DEG) response was seen in granulocytes, while macrophage DEGs differed in directionality by subtype and line. Among the most DEG in almost all immune cell types were granzyme and granulysin, both associated with cell-perforating processes. Protein interactive network analyses revealed multiple overlapping canonical pathways within both lymphoid and myeloid cell lineages. This initial estimation of the chicken immune cell type landscape and its accompanying response will greatly aid efforts in identifying specific cell types and improving our knowledge of host response to viral infection.
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