580 research outputs found
Population and community responses to anthropogenic environmental changes
Humans are dramatically altering the planet. I use classic ecological theory, original conceptual models, and a novel analytical tool (Rank Occupancy-Abundance Profiles; ROAPs) to explore the effects anthropogenic changes have on plant communities and bird populations. Chapter one investigates the influence of nutrient deposition on native prairie grass communities. I show that soil phosphorus levels alter plant diversity by changing the degree to which mycorrhizae benefit plant species. Chapter two investigates plant extinctions in a fragmented landscape. Extinction rates of early-successional plant species on large versus small habitat patches vary according to species' life history traits. In Chapter three I quantify declines in North American bird species over the past 30 years. Nearly 20% of the 209 birds sampled are declining significantly; local densities tend to decline prior to occupancy. Results from this dissertation confirm that humans are dramatically altering the relative abundance of species--at local, landscape, and continental scales
Fixed-shop retailing: Shrewsbury and Woverhampton 1660-1900
A thesis submitted in partial fulfilment of the requirements of the University of Wolverhampton for the degree of Doctor of PhilosophyDisregard for the everyday and the ordinary often leads to unwarranted neglect. This for many decades was the fate of shop retailing in terms of historical investigation and even intellectual debate. Yet, more recently research concerned with identifying the emergence of a consumer society has stimulated interest in the development of the retail sector in terms of the timing of growth and the extent of change. Within this context this thesis investigates the structure and organisation of shop retailing, and the gender of shop retailers in two contrasting communities: Shrewsbury and Wolverhampton 1660-1900. The aims of this research are twofold. First it will be demonstrated that a longitudinal perspective is not only possible but also imperative in determining the nature of short-term change in the retail sector. Diverse sources are used comparatively to address the conceptual and methodological difficulties, which have previously hindered analyses of existing research. A numerical analysis of the number of shops, trades within shops, specialist nature and scale of shops indicates that the move towards a modem system of retailing was determined as much by factors of demand as changes in supply. An evaluation has also been made of the impact of retail change on the gender of shop owners, employers and employees. Throughout the period men owned-more shops, employed more shop workers and had access to more trades than women. Yet, by 1900 they served apprenticeships less often, were less likely to become shop owners than two centuries earlier and faced increasing competition for employment in large-scale drapery stores. The pattern was somewhat reversed for women. With the exception of the millinery trades women only became shop owners c1700 when they were widowed. In this capacity they were not restricted regarding the trades they could enter. Single women rarely owned shops and had no access to the great majority of trades. By c1900 single, married and widowed women owned shops but are found in a limited number of trades. This study shows that not only is it possible to adopt a longitudinal framework but also necessary if the extent and pace of change recorded for the nineteenth century is to be accurately assessed. Thus it has been possible to determine that despite the move to modernity, and this was more incremental than rapid, most shops were still owner or family run, small rather than large-scale and with the exception of one or two trades the province of male ownership and male labour
Modality Switching in a Property Verification Task: An ERP Study of What Happens When Candles Flicker after High Heels Click
The perceptual modalities associated with property words, such as flicker or click, have previously been demonstrated to affect subsequent property verification judgments (Pecher et al., 2003). Known as the conceptual modality switch effect, this finding supports the claim that brain systems for perception and action help subserve the representation of concepts. The present study addressed the cognitive and neural substrate of this effect by recording event-related potentials (ERPs) as participants performed a property verification task with visual or auditory properties in key trials. We found that for visual property verifications, modality switching was associated with an increased amplitude N400. For auditory verifications, switching led to a larger late positive complex. Observed ERP effects of modality switching suggest property words access perceptual brain systems. Moreover, the timing and pattern of the effects suggest perceptual systems impact the decision-making stage in the verification of auditory properties, and the semantic stage in the verification of visual properties
Teacher Strategies for Reducing the Achievement Gap for ELL Students
AbstractAn influx in Hispanic English language learners (ELLs) in Atlanta public schools has led to a broadening of the achievement gap between ELLs and native English speakers, causing higher failure rates and fewer career possibilities for Hispanic ELLs upon school completion. The purpose of this basic qualitative study was to investigate the kinds of strategies K through eighth grade teachers use to reduce this achievement gap, specifically in English and math. Vygotsky’s social learning theory guided this study, a key aspect of which is the role dialect and language play in determining a student’s development. The study focused on how social foundations (e.g., identity, language, culture, and class) shape ELL students’ learning processes from the teachers’ perspective. Purposeful sampling identified K through eighth grade teachers whose instructional strategies focused specifically on their personal scaffolding techniques. The findings indicated that participants frequently use language and culture scaffolding to help Hispanic ELL students in English and mathematics close/reduce the achievement gap. To achieve excellent academic standards, participants established diversified instruction and student modeling, promoted cultural diversity, collaborated with students, observed them, and ensured ongoing involvement. Participants also used gestures, images, translators or interpreters, student collaboration, and technology support to communicate with students who do not speak English well. To effect positive social change, participants identified a variety of resources, skills, knowledge, and professional assistance to improve the effectiveness of ELL teaching strategies in closing/reducing the achievement gaps for Hispanic ELLs in English and mathematics
Patch size effects on plant species decline in an experimentally fragmented landscape
This is the publisher's version, also available electronically from http://www.esa.org/esa.Understanding local and global extinction is a fundamental objective of both basic and applied ecology. Island biogeography theory (IBT) and succession theory provide frameworks for understanding extinction in changing landscapes. We explore the relative contribution of fragment size vs. succession on species' declines by examining distributions of abundances for 18 plant species declining over time in an experimentally fragmented landscape in northeast Kansas, USA. If patch size effects dominate, early-successional species should persist longer on large patches, but if successional processes dominate, the reverse should hold, because in our system woody plant colonization is accelerated on large patches. To compare the patterns in abundance among patch sizes, we characterize joint shifts in local abundance and occupancy with a new metric: rank occupancy–abundance profiles (ROAPs). As succession progressed, statistically significant patch size effects emerged for 11 of 18 species. More early-successional species persisted longer on large patches, despite the fact that woody encroachment (succession) progressed faster in these patches. Clonal perennial species persisted longer on large patches compared to small patches. All species that persisted longer on small patches were annuals that recruit from the seed bank each year. The degree to which species declined in occupancy vs. abundance varied dramatically among species: some species declined first in occupancy, others remained widespread or even expanded their distribution, even as they declined in local abundance. Consequently, species exhibited various types of rarity as succession progressed. Understanding the effect of fragmentation on extinction trajectories requires a species-by-species approach encompassing both occupancy and local abundance. We propose that ROAPs provide a useful tool for comparing the distribution of local abundances among landscape types, years, and species
Extraction of Volatiles from Regolith or Soil on Mars, the Moon, and Asteroids
NASA's Advanced Exploration Systems ISRU Technology Project is evaluating concepts to extract water from all resource types Near-term objectives: Produce high-fidelity mass, power, and volume estimates for mining and processing systems Identify critical challenges for development focus Begin demonstration of component and subsystem technologies in relevant environment Several processor types: Closed processors either partially or completely sealed during processing Open air processors operates at Mars ambient conditions In-situ processors Extract product directly without excavation of raw resource Design features Elimination of sweep gas reduces dust particles in water condensate Pressure maintained by height of soil in hopper Model developed to evaluate key design parameters Geometry: conveyor diameter, screw diameter, shaft diameter, flight spacing and pitch Operational: screw speed vs. screw length (residence time) Thermal: Heat flux, heat transfer to soil Testing to demonstrate feasibility and performance Agglomeration, clogging Pressure rise forced flow to condenser
Exploring the Experiences of Black/African American Students in Entry Level Occupational Therapy and Occupational Therapy Assistant Programs: A Survey Study
Black/African American students account for 6.5% of the enrollment in entry-level occupational therapy (OT) and occupational therapy assistant (OTA) programs (AOTA, 2019). OT and OTA programs serve as the entry point to increasing diversity in the profession and contribute to a diverse healthcare workforce. Limited research exists that offers insight into the experiences of minority students enrolled in OT and OTA programs. The purpose of this study was to explore the academic experiences of Black/African American students enrolled in entry-level OT and OTA programs to identify supports and barriers in the educational experience. Eligible participants were asked to complete an anonymous survey that explored the experiences in the recruitment and admissions processes, interactions with faculty and peers, and other factors that influenced their learning experience. 124 respondents completed the nationwide survey. The respondents listed faculty and staff support, the use of diverse learning materials, and a supportive fieldwork environment as very important to a positive educational experience. A lack of faculty and staff support, financial concerns, and level of comfort sharing their life and cultural perspectives with classmates were listed as barriers to the educational experience. Results of this study provide insight on important factors that affect the student learning experience and can inform OT and OTA programs about potential areas of strength and identify areas of need to develop learning environments that encourage supportive and inclusive experiences for the next generation of OT practitioners
Efficacy of treatment in an opioid –dependent population group using the Maudsley Addiction Profile (MAP) tool
A pilot study was performed to assess the effectiveness of treatment in an opioid dependent population using the Maudsley Addiction Profile (MAP) tool1
Geotechnical Observations of the November 3, 2002 M7.9 Denali Fault Earthquake
The M 7.9 earthquake of November 3, 2002 event ruptured more than 340 kilometers on three fault, causing widespread liquefaction in the fluvial deposits of steep alpine valleys of the Alaska Range and eastern lowlands of the Tanana River. The event occurred in a remote and largely undeveloped portion of the rugged Alaskan central range, with few seismometer recordings. The areas affected by liquefaction are largely confined to native Holocene river deposits, areas bounded by stiffer ground moraine, Pleistocene uplands, and bedrock. Liquefaction affected areas of alluvial river valleys draining mountainous and glacier-proximal rivers. The most noteworthy observations are that liquefaction damage was focused towards the eastern end of the rupture area. In the western portion of the rupture zone, localized liquefaction developed in recent deposits of the Susitna and Delta rivers in the immediate vicinity of the surface rupture of the fault. More abundant and severe liquefaction occurred on the eastern Robertson, Slana, Tok, Chisana and, especially, Nabesna Rivers. In the Tanana lowland, liquefaction features were sparse on the western bars of the Tanana River in the vicinity of Fairbanks to west of Delta, but became pervasive throughout the eastern region from Delta to Northway. Though liquefaction observations were abundant, there was a dearth of instrumental recordings useful to relate damage effects to measured intensity. To characterize soil properties and stiffness of liquefaction evaluation sites, we used a portable spectral analysis of surface waves (SASW) apparatus to profile the shear wave velocity of the ground. On the Nabesna and Delta rivers that cross the fault, we only observe liquefaction features in soil deposits where normalized shear wave velocities fall below 230 m/s. Severity of sand boils, fissuring and lateral displacement of liquefied ground dramatically increase in soils of lower shear wave velocity, especially below 170 m/s. Some of the most pronounced ground failures are far from the fault zone (60-100 km) in extremely loose, low velocity (~120 m/s) fine sands of the bars of the Tanana River. Strong motion instrumentation was sparse within 150 kilometers of the fault rupture and the seismometers of Alyeska pump stations PS9 (PGA=0.09), PS10 (PGA=0.36g), and PS11 (PGA=0.09) serve as the principal strong motion recordings. Insufficient strong motion instrumentation is available to identify areas of amplified ground motio
Perception of academic learning environments and perceived impact on articulation of employability; a mixed methods study
This study reports on the findings of a mixed methods study that was undertaken to
establish student perceptions of academic learning environments and the perceived
impact of these on their articulation of employability skills. This was so student
perspectives on employability could be used to inform reflection on pedagogic practices for
their educators in higher education. Using a purposive sample of 250 students based in a
recently modernised Sciences Complex Building in a Higher Education Institution (HEI),
the study was cross sectional and descriptive by design. The social learning spaces
researched were perceived by participants to provide optimal academic learning
environments for their development of knowledge, skills and professionalism through
certain signature pedagogies as they progressed through their programmes of study.
Students also expressed the view that their acquisition of functional skills were significantly
more important than any personal attributes/characteristics that they brought to
programmes. What also mattered was whether the importance of certain graduate skills to
the workplace had been made explicit to them so that they could see the relevance of their
studies to practice. In defining ‘graduateness’, in employability terms the research
Hayes et al. Perception of academic learning environments and perceived impact on articulation of employability skills
Journal of Learning Development in Higher Education, Issue 10: November 2016 2
concluded that it was necessary to consider how it was shaped by the context of delivery
of subject disciplines, stages of academic progression, and the use of social learning
spaces, as they all had a significant impact on the perceptions students held about their
potential employability upon completion of their academic programmes.
Keywords: learning environments; employability; signature pedagogies; situated
cognition; problem based learning
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