
University of Maine at Farmington
UniversityFarmington, Maine, United States
Research output, citation impact, and the most-cited recent papers from University of Maine at Farmington (United States). Aggregated across the NobleBlocks index of 300M+ scholarly works.
Top-cited papers from University of Maine at Farmington
High-resolution radar images reveal near-Earth asteroid (66391) 1999 KW4 to be a binary system. The approximately 1.5-kilometer-diameter primary (Alpha) is an unconsolidated gravitational aggregate with a spin period approximately 2.8 hours, bulk density approximately 2 grams per cubic centimeter, porosity approximately 50%, and an oblate shape dominated by an equatorial ridge at the object's potential-energy minimum. The approximately 0.5-kilometer secondary (Beta) is elongated and probably is denser than Alpha. Its average orbit about Alpha is circular with a radius approximately 2.5 kilometers and period approximately 17.4 hours, and its average rotation is synchronous with the long axis pointed toward Alpha, but librational departures from that orientation are evident. Exotic physical and dynamical properties may be common among near-Earth binaries.
A new method of measuring reproductive success was used to test Van Horne's (1983) contention that reliance on population density as a measure of habitat quality can produce misleading results. None of the three emberizine sparrows in this study showed a clear correlation between high territory density and high reproductive success Grasshopper Sparrows(Ammodramus savannarum) were most successful in medium-density plots, and did poorly when territory density was low. Savannah Sparrows (Passerculus sandwichensis) were significantly more successful at low density, and were least successful at high density. Vesper Sparrows (Pooecetes gramineus) were the only species whose reproductive success was unaffected By territory density and, thus, for which density would have been a reasonable measure of habitat quality. These results lend support to Van Horne's thesis that the singular use of density may be a poor indicator of habitat quality and that additional factors should be considered.
Radar observations of the main-belt, M-class asteroid 216 Kleopatra reveal a dumbbell-shaped object with overall dimensions of 217 kilometers by 94 kilometers by 81 kilometers (+/-25%). The asteroid's surface properties are consistent with a regolith having a metallic composition and a porosity comparable to that of lunar soil. Kleopatra's shape is probably the outcome of an exotic sequence of collisional events, and much of its interior may have an unconsolidated rubble-pile structure.
Several studies of telecommuting and working at home have alluded to the blurring line between work and family that can result from such highly integrated work-family arrangements. However, little is known about working parents’ perceptions of the integration and blurring of their work and family roles. In this study, the authors created and validated the Work-Family Integration-Blurring Scale using a national sample of business professors raising children in two-parent families. Based on boundary theory and work-family border theory, the authors expected scores on this scale to be associated with the number of hours worked at home and on campus, the number of work-family transitions made when working at home, the presence of distractions when working at home, and the presence of work-family conflict. The scale’s significant and moderately high correlations with these variables supported its construct validity. The research implications and practical implications of the findings are discussed.
Radar and optical observations reveal that the continuous increase in the spin rate of near-Earth asteroid (54509) 2000 PH5 can be attributed to the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect, a torque due to sunlight. The change in spin rate is in reasonable agreement with theoretical predictions for the YORP acceleration of a body with the radar-determined size, shape, and spin state of 2000 PH5. The detection of asteroid spin-up supports the YORP effect as an explanation for the anomalous distribution of spin rates for asteroids under 10 kilometers in diameter and as a binary formation mechanism.
Background Since the 1950s, there has been a growing body of research dealing with perceptions children have of scientists. Typically, research studies in this area have utilized children's drawings in an effort to discern what those perceptions are. Studies assessing perceptions children have of scientists have shown that children have stereotypical images of scientists. Although there is no direct evidence to demonstrate the link between children's images of science and scientists with their career choice, several researchers (including this researcher) have assumed that children's attitudes towards science are greatly influenced by their perceptions of science and scientists. Purpose This study aimed to find out if there was a difference in the way 5- to 8-year-old children drew scientists, taking account of age, gender and socio-economic status. Sample For this study a convenience sample of 30 young children was used. Participants included young children between the ages of 5 and 8 years from a public elementary school in Ankara, the capital city of Turkey. Although the sample of the study was obtained from one school in a metropolitan area, children involved in this preliminary study were from very different socio-economic backgrounds. As the sample size is very small for making comparisons, it was intended to have a similar number of children from different age groups and socio-economic backgrounds and both genders. Design and methods The researcher worked individually with each child who participated in this study in an interview setting. Although each child was asked a set of standard questions, and given a standard set of directions, each interview session was informal enough to allow the researcher to gain additional information about children's drawings and to clarify any of their responses. During the interview sessions, children's responses were noted by the researcher. Before the children were asked to draw their picture of a scientist, they were offered a set of coloured pencils or crayons and told to feel free to colour their drawing or any parts of it they would like to accentuate. At the end of the interview and drawing sessions, the researcher went through all the drawings and notes to get a ‘feel’ for and ascertain what was being said, identifying key themes in each drawing. Results The most common scientist type drawn in this study was the stereotypical scientist type: someone who conducts research, or someone who tries to invent a new material. But unlike previous studies, around 35% of the scientist figures drawn (n = 15) were of the social scientist type. Stereotypical images drawn by the current study participants included symbols of research, such as scientific instruments and laboratory equipment of all kinds, and symbols of knowledge, principally books and cabinets, technology and the products of science. An interesting finding of this study was that perceptions of young children differed due to their age. Children at the age of 8 years drew non-stereotypical scientist images, and they drew more detail than did their younger peers. When children were compared in terms of their gender, no significant differences were observed between girls and boys. But on the other hand, none of the boys drew female scientists, and five out of 30 children who were girls drew female scientists. While children of parents with lower socio-economic status drew more stereotypical scientist images, children of parents with higher economic status drew different images of scientists, a result which showed us that the scientist perceptions of young children differ with socio-economic status. Conclusions Emergent from this research has been a non-stereotypical perception of scientists, and some evidence exists that such a non-stereotypical perception differs due to age and socio-economic status. While these images may seem amusing, they also provide a reflection of the image that children have about what a scientist looks like. These images may have a powerful impact on present functioning and future plans of young children.
Abstract Long‐term lake ice phenological records from around the Northern Hemisphere provide unique sensitive indicators of climatic variations, even prior to the existence of physical meteorological measurement stations. Here, we updated ice phenology records for 60 lakes with time‐series ranging from 107–204 years to provide the first re‐assessment of Northern Hemispheric ice trends since 2004 by adding 15 additional years of ice phenology records and 40 lakes to our study. We found that, on average, ice‐on was 11.0 days later, ice‐off was 6.8 days earlier, and ice duration was 17.0 days shorter per century over the entire record for each lake. Trends in ice‐on and ice duration were six times faster in the last 25‐year period (1992–2016) than previous quarter centuries. More extreme events in recent decades, including late ice‐on, early ice‐off, shorter periods of ice cover, or no ice cover at all, contribute to the increasing rate of lake ice loss. Reductions in greenhouse gas emissions could limit increases in air temperature and abate losses in lake ice cover that would subsequently limit ecological, cultural, and socioeconomic consequences, such as increased evaporation rates, warmer water temperatures, degraded water quality, and the formation of toxic algal blooms.
Radar is a uniquely powerful source of information about the physical properties and orbits of asteroids.Measurements of the distribution of echo power in time delay (range) and Doppler frequency (radial velocity) produce two-dimensional images that can provide spatial resolution as fine as a decameter if the echoes are strong enough.With adequate orientational coverage, such images can be used to construct detailed three-dimensional models, define the rotation state precisely, and constrain the object's internal density distribution.As of May 2002, radar signatures have been measured for 75 main-belt asteroids (MBAs) and 105 near-Earth asteroids (NEAs).We summarize specific results for radar-detected asteroids, which span 4 orders of magnitude in diameter and rotation period.Radar has revealed both stony and metallic objects, principal-axis and complex rotators, smooth and extremely rough surfaces, objects that must be monolithic and objects that probably are not, spheroids and highly elongated shapes, contact-binary shapes, and binary systems.Radar also has expanded accurate orbit-prediction intervals for NEAs by as much as several centuries.
A new method of measuring reproductive success is proposed that uses a composite of breeding-behavior observations (for behaviors that reflect different stages in the reproductive cycle) as an index of fitness. This reproductive index does not rely on discovery of nests, but is comprehensive in that it includes information on all monitored territories. The reproductive index was applied to three co-occurring grassland emberizine sparrows, two of which required special care because of their regional rarity. Ranks derived from this reproductive index were used to distinguish territories of birds of known high success(i .e. those that fledged young in at least one brood) from territories of birds with known low success(unpaired males), and were compared with findings for "spot-mapped" territories. Principal-components analyse s of habitat measurements for these territory types revealed a similar pattern for all three species: spot-mapped territories overlapped broadly with non territory (unoccupied) plots, whereas high-success territories formed a discrete, isolated cluster within the spot-map matrix. Univariate analyses revealed that high-success territories were described b y 15 vegetation features that differed (P 0.01) from non territory values, whereas in spot-mapped territories only 8 vegetation measures differed and in low success territories only 2 differed. The ability to distinguish high-success territories allowed us to identify a greater number of habitat features that were correlated with reproductive success If. we had relied on the spot-mapping method, we would have been unable to identify many of these important habitat features. Yet, the ability to make such discriminations is likely to be critical in the management of threatened species.
Dynamical simulations of the coupled rotational and orbital dynamics of binary near-Earth asteroid 66391 (1999 KW4) suggest that it is excited as a result of perturbations from the Sun during perihelion passages. Excitation of the mutual orbit will stimulate complex fluctuations in the orbit and rotation of both components, inducing the attitude of the smaller component to have large variation within some orbits and to hardly vary within others. The primary's proximity to its rotational stability limit suggests an origin from spin-up and disruption of a loosely bound precursor within the past million years.
Medical cannabis (MC) is used for a variety of conditions including chronic pain. The goal of this report was to provide an in-depth qualitative exploration of patient perspectives on the strengths and limitations of MC. Members of MC dispensaries (N = 984) in New England including two-thirds with a history of chronic pain completed an online survey. In response to "How effective is medical cannabis in treating your symptoms or conditions?," with options of 0% "no relief" to 100% "complete relief," the average was 74.6% ± 0.6. The average amount spent on MC each year was $3064.47 ± 117.60, median = $2320.23, range = $52.14 to $52,140.00. Open-ended responses were coded into themes and subthemes. Analysis of answers to "What is it that you like most about MC?" (N = 2592 responses) identified 10 themes, including health benefits (36.0% of responses, eg, "Changes perception and experience of my chronic pain."), the product (14.2%, eg, "Knowing exactly what strain you are getting"), nonhealth benefits (14.1%), general considerations (10.3%), and medications (7.1%). Responses (N = 1678) to "What is it that you like least about MC?" identified 12 themes, including money (28.4%, eg, "The cost is expensive for someone on a fixed income"), effects (21.7%, eg, "The effects on my lungs"), the view of others (11.4%), access (8.2%), and method of administration (7.1%). These findings provide a patient-centered view on the advantages (eg, efficacy in pain treatment, reduced use of other medications) and disadvantages (eg, economic and stigma) of MC.
Abstract The paper investigates the development and use of corporate social and environmental reporting by businesses within a large municipality in South Africa. There is a strong call for improved CSR, and a greater degree of accountability and transparency by business. The survey was conducted through the use of interviews following a structured questionnaire with the Global Reporting Initiative used as an appropriate framework. This approach allowed us to determine the challenges businesses face in implementing a comprehensive CSR system in the South African context and why, other than companies which are part of a group, businesses are unable or unwilling to increase external reporting. We suggest that implementation of a comprehensive and externally controlled and certified standard, such as ISO 14001 would not only reduce environmental impacts, but facilitate increased CSR. Copyright © 2008 John Wiley & Sons, Ltd and ERP Environment.
Intravenous infusion of T-MSCs alleviated colitis in mice by elevating the circulating IGF-1 level. Increased IGF-1 maintained the integrity of epithelial cells and contributed to their repair and regeneration. Our study has identified T- MSCs as a potential cell resource for IBD treatment.
Large vertebrates affect fire regimes in several ways: by consuming plant matter that would otherwise accumulate as fuel; by controlling and varying the density of vegetation; and by engineering the soil and litter layer. These processes can regulate the frequency, intensity and extent of fire. The evidence for these effects is strongest in environments with intermediate rainfall, warm temperatures and graminoid-dominated ground vegetation. Probably, extinction of Quaternary megafauna triggered increased biomass burning in many such environments. Recent and continuing declines of large vertebrates are likely to be significant contributors to changes in fire regimes and vegetation that are currently being experienced in many parts of the world. To date, rewilding projects that aim to restore large herbivores have paid little attention to the value of large animals in moderating fire regimes. Rewilding potentially offers a powerful tool for managing the risks of wildfire and its impacts on natural and human values.This article is part of the theme issue 'Trophic rewilding: consequences for ecosystems under global change'.
The technological, pedagogical, and content knowledge (TPACK) framework considers the role of technology in teaching. Although TPACK is grounded in context, one limitation is the lack of understanding about the interactions between particular contexts, knowledge development, and instruction. This qualitative multiple-case study was designed to explore the contextual factors that contribute to teachers' development of technological, pedagogical, and content knowledge and practice. Researchers focused on the Catholic educational environment to develop a more refined understanding of specific, and unique, contextual factors within the TPACK framework. Individual case analysis of interview and observation data pointed toward microlevel, or teacher-centric, factors, including background, attitudes, and personal conceptualization of contemporary education, to be primary influences of the development and use of technological knowledge. Recommendations are made for educators to think about how changes in context influence the distinct overlapping components of the TPACK framework, and accordingly their individual TPACK. (Keywords: TPACK, educational technology, teacher practice, teacher context)
BACKGROUND: This study was designed to measure the involvement of eosinophils, neutrophils, and mast cells in the middle ear of patients with OME and to see whether that inflammatory response differed depending on whether or not the patient was atopic. METHODS: Levels of ECP, MPO, and tryptase were measured in effusion from 97 patients whose atopic status was determined by in vitro testing with 12 inhalants and five foods. RESULTS: Seventy-nine of 97 OME patients (81%) were atopic, among whom 86% (68/79) had elevated levels of effusion ECP, and 64% (23/36) had elevated tryptase. Mean ECP was 166 microg/l vs 3.38 microg/l, mean MPO was 6231 microg/l vs 116 microg/l, and mean tryptase was 4.8 microg/l vs 1.34 microg/l in atopic vs nonatopic ears. Total serum IgE did not differ between atopics and nonatopics (P=0.28). CONCLUSIONS: The inflammatory response by eosinophils, neutrophils, and mast cells in the middle ear was distinctly different between atopic and nonatopic patients (P < 0.001). This study provides evidence that eosinophils and mast cells, both essential to a Th-2 driven immune response, are present in the majority of ears with chronic OME, and supports the hypothesis that middle-ear mucosa, like that of the rest of the upper respiratory tract, is capable of an allergic response.
Through this case study the author explores how an exemplary teacher utilized social studies curriculum and pedagogy to engage English language learners (ELLs) in learning in a culturally relevant and meaningful way and discusses practical implications for teaching and learning.
Abstract— Radar data enable us to estimate an asteroid's near‐surface bulk density, thus providing a joint constraint on near‐surface porosity and solid density. We investigate two different approaches to simplifying this joint constraint: estimating solid densities by assuming uniform porosities for all asteroids; and estimating porosities by assuming uniform mineralogy within each taxonomic class. Methods used to estimate asteroids' near‐surface solid densities from radar data have not previously been calibrated via independent estimates. Recent spacecraft results on the chondritic nature of 433 Eros now permit such a check, and also support porosity estimation for S‐class objects. We use radar albedos and polarization ratios estimated for 36 main‐belt asteroids and nine near‐Earth asteroids to estimate near‐surface solid densities using two methods, one of which is similar to the uncalibrated algorithms used in previous studies, the other of which treats Eros as a calibrator. We also derive porosities for the same sample by assigning solid densities for each taxonomic class in advance. Density‐estimation results obtained for Eros itself are consistent with the uncalibrated method being valid in the mean; those derived for the full sample imply that uncalibrated solid densities are, at most, a few tens of percent too large on average. However, some derived densities are extremely low, whereas most porosity estimates are physically plausible. We discuss the relative merits of these two approaches.
Abstract This paper reviews the historical and theoretical contexts that have contributed to the concept of readiness, in particular reading readiness. It provides a comparison of influential emerging perspectives on early literacy and suggests that an exploration of the assumptions that undergird early literacy instruction can be a useful starting point for discussion of the nature of literacy and the processes of learning. Further, because these perspectives have varied perceptions about how children are viewed in American society and suggest different futures for young children's education, their implications for research and practice are of interest.
Abstract— We observed 25143 Itokawa, the target of Japan's Hayabusa (MUSES‐C) sample‐return mission, during its 2001 close approach at Arecibo on twelve dates during March 18‐April 9 and at Goldstone on nine dates during March 20‐April 2. We obtained delay‐Doppler images with range resolutions of 100 ns (15 m) at Arecibo and 125 ns (19 m) at Goldstone. Itokawa's average circular polarization ratio at 13 cm, 0.26 ± 0.04, is comparable to that of Eros, so its cm‐to‐m surface roughness probably is comparable to that on Eros. Itokawa's radar reflectivity and polarization properties indicate a near‐surface bulk density within 20% of 2.5 g cm −3 . We present a preliminary estimate of Itokawa's shape, reconstructed from images with rather limited rotation‐phase coverage, using the method of Hudson (1993) and assuming the lightcurve‐derived spin period (12.132 hr) and pole direction (ecliptic long., lat. = 355°, −84°) of Kaasalainen et al. (2003). The model can be described as a slightly asymmetrical, slightly flattened ellipsoid with extents along its principal axes of 548 times 312 times 276 m ± 10%. Itokawa's topography is very subdued compared to that of other asteroids for which spacecraft images or radar reconstructions are available. Similarly, gravitational slopes on our Itokawa model average only 9° and everywhere are less than 27°. The radar‐refined orbit allows accurate identification of Itokawa's close planetary approaches through 2170. If radar ranging planned for Itokawa's 2004 apparition succeeds, then tracking of Hayabusa during its 2005 rendezvous should reveal Yarkovsky perturbation of the asteroid's orbit.