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Institution

University of Maine

EducationOrono, Maine, United States
About: University of Maine is a education organization based out in Orono, Maine, United States. It is known for research contribution in the topics: Population & Ice sheet. The organization has 8637 authors who have published 16932 publications receiving 590124 citations. The organization is also known as: University of Maine at Orono.


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Journal ArticleDOI
TL;DR: In this article, the ages of Little Ice Age moraines suggest fluctuating glacier expansion between ad 1500 and the early 20th century, with a culmination about 2600 and 2800 14C yr BP.

142 citations

Journal ArticleDOI
TL;DR: Results of the present study support the recommendation to avoid rotating imidacloprid with thiamethoxam as a part of a resistance management plan and substantial cross-resistance among the three tested neonicotinoid insecticides.
Abstract: One of the major challenges in managing the Colorado potato beetle, Leptinotarsa decemlineata (Say) is its remarkable ability to develop resistance to virtually every insecticide that has ever been used against it Resistance is particularly common throughout northeastern USA as far north as Maine The first instances of resistance to imidacloprid have already been reported from several locations in New York, Delaware and southern Maine Rotating insecticides with different modes of action may delay insecticide resistance, but successful implementation of this technique depends on a good understanding of resistance and cross-resistance patterns in populations of target pests LC(50) values were measured for imidacloprid and thiamethoxam in Colorado potato beetle populations from a variety of locations in the USA and Canada using diet incorporation bioassays The field performance of imidacloprid, thiamethoxam and clothianidin against imidacloprid-resistant beetles on a commercial potato farm in southern Maine was also evaluated Correlation between LC(50) values for imidacloprid and thiamethoxam was highly significant, even when populations previously exposed to thiamethoxam were excluded from the analysis There was no statistically detectable difference in the LC(50) values between populations exposed to both insecticides and to imidacloprid alone Applications of neonicotinoid insecticides at planting delayed build-up of imidacloprid-resistant beetle populations on field plots by 1-2 weeks but failed to provide adequate crop protection Consistently with bioassay results, there was also substantial cross-resistance among the three tested neonicotinoid insecticides Results of the present study support the recommendation to avoid rotating imidacloprid with thiamethoxam as a part of a resistance management plan

142 citations

Journal ArticleDOI
TL;DR: The RLD and leaf area index (LAI) at all four sample dates during 1994 were significantly correlated with final tuber yields, indicating that growth patterns early in the season were important in establishing the productivity of the potato crop.
Abstract: This study was conducted to determine if supplemental irrigation and/or application of soil amendments rich in organic matter can improve root growth of potato (Solanum tuberosum L.). Root length density (RLD) and root dry matter production of potato were studied under two levels of supplemental irrigation (nonirrigated check vs. moderate irrigation) and two levels of soil amendments [none vs. amended with compost and manure from beef cattle (Bos taurus L.)] during 1993 and 1994. Ameudments significantly increased RLD during both growing seasons and these increases occurred consistently throughout each growing season. Irrigation effects were not observed in 1993, while irrigation significantly increased RLD during 1994. Approximately 85% of the root length was concentrated in the upper 30-cm layer of the soil. The supplemental irrigation and soil amendment treatments did not affect the proportional distribution of roots among the soil layers. Root-to-shoot ratio was not affected by irrigation or amendment during either growing season. The RLD and leaf area index (LAI) at all four sample dates during 1994 were significantly correlated with final tuber yields, indicating that growth patterns early in the season were important in establishing the productivity of the potato crop. Root length density tended to have a higher correlation with yields than did LAI (r = 0.58 * to 0.80 ** vs. 0.51 * to 0.68 ** ).

142 citations

Journal ArticleDOI
TL;DR: In this paper, the authors identify ecological principles for MSP based on a synthesis of previously suggested and/or operationalized principles, along with recommendations generated by a group of twenty ecologists and marine scientists with diverse backgrounds and perspectives on MSP.
Abstract: The declining health of marine ecosystems around the world is evidence that current piecemeal governance is inadequate to successfully support healthy coastal and ocean ecosystems and sustain human uses of the ocean. One proposed solution to this problem is ecosystem-based marine spatial planning (MSP), which is a process that informs the spatial distribution of activities in the ocean so that existing and emerging uses can be maintained, use conflicts reduced, and ecosystem health and services protected and sustained for future generations. Because a key goal of ecosystem-based MSP is to maintain the delivery of ecosystem services that humans want and need, it must be based on ecological principles that articulate the scientifically recognized attributes of healthy, functioning ecosystems. These principles should be incorporated into a decision-making framework with clearly defined targets for these ecological attributes. This paper identifies ecological principles for MSP based on a synthesis of previously suggested and/or operationalized principles, along with recommendations generated by a group of twenty ecologists and marine scientists with diverse backgrounds and perspectives on MSP. The proposed four main ecological principles to guide MSP—maintaining or restoring: native species diversity, habitat diversity and heterogeneity, key species, and connectivity—and two additional guidelines, the need to account for context and uncertainty, must be explicitly taken into account in the planning process. When applied in concert with social, economic, and governance principles, these ecological principles can inform the designation and siting of ocean uses and the management of activities in the ocean to maintain or restore healthy ecosystems, allow delivery of marine ecosystem services, and ensure sustainable economic and social benefits.

142 citations

Journal ArticleDOI
TL;DR: In this paper, annealing was identified as a suitable post-processing method to improve the interlayer tensile strength of extrusion-based 3D printed composites, and two different thermoplastic polymers, which are common in 3D printing, were selected to study the enhancement of interlayer strength of composites by additive manufacturing: an amorphous polyethylene terephthalate-glycol (PETG), and a semi-crystalline poly (lactic acid) (PLA).
Abstract: Previous studies have shown that 3D printed composites exhibit an orthotropic nature with inherently lower interlayer mechanical properties. This research work is an attempt to improve the interlayer tensile strength of extrusion-based 3D printed composites. Annealing was identified as a suitable post-processing method and was the focus of this study. Two distinct thermoplastic polymers, which are common in 3D printing, were selected to study the enhancement of interlayer tensile strength of composites by additive manufacturing: a) an amorphous polyethylene terephthalate-glycol (PETG), and b) a semi-crystalline poly (lactic acid) (PLA). It was determined that short carbon fiber reinforced composites have lower interlayer tensile strength than the corresponding neat polymers in 3D printed parts. This reduction in mechanical performance was attributable to an increase in melt viscosity and the consequential slower interlayer diffusion bonding. However, the reduction in interlayer tensile strength could be recovered by post-processing when the annealing temperature was higher than the glass transition temperature of the amorphous polymer. In the case of the semi-crystalline polymer, the recovery of the interlayer tensile strength was only observed when the annealing temperature was higher than the glass transition temperature but lower than the cold-crystallization temperature. This study utilized rheological and thermal analysis of 3D printed composites to provide a better understanding of the interlayer strength response and, therefore, overcome a mechanical performance limitation of these materials.

142 citations


Authors

Showing all 8729 results

NameH-indexPapersCitations
Clifford J. Rosen11165547881
Juan S. Bonifacino10830346554
John D. Aber10720448500
Surendra P. Shah9971032832
Charles T. Driscoll9755437355
Samuel Madden9538846424
Lihua Xiao9349532721
Patrick G. Hatcher9140127519
Pedro J. J. Alvarez8937834837
George R. Pettit8984831759
James R. Wilson89127137470
Steven Girvin8636638963
Peter Marler8117422070
Garry R. Buettner8030429273
Paul Andrew Mayewski8042029356
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202332
2022134
2021834
2020756
2019738
2018725