The effects of regional angling effort, angler behavior, and harvesting efficiency on landscape patterns of overfishing

2011 ◽  
Vol 21 (7) ◽  
pp. 2555-2575 ◽  
Author(s):  
Len M. Hunt ◽  
Robert Arlinghaus ◽  
Nigel Lester ◽  
Rob Kushneriuk
Keyword(s):  
Landscape Patterns ◽  
Harvesting Efficiency ◽  
Angler Behavior

USE OF ATTRACTED GRAIN HARVESTERS

2020 ◽  
Author(s):  
G.N. Erokhin ◽  
◽  
W.W. Konovsky ◽  
Keyword(s):  
Third Party ◽  
Decisive Influence ◽  
Agricultural Enterprise ◽  
Efficiency Losses ◽  
Harvesting Efficiency

A model for the use of own and attracted combines in an agricultural enterprise is developed. Estimated indicator of the model is the loss of grain harvesting efficiency. The dependences of efficiency losses on the volume of work of attracted combines were obtained for various loading of their own combines. It was revealed that loading of own combines has a decisive influence on the efficiency of using third-party combines.

Changes and driving forces of land use/cover and landscape patterns in Beijing-Tianjin-Hebei region

2012 ◽  
Vol 19 (5) ◽  
pp. 1182-1189 ◽  
Author(s):  
Qiao-Li HU ◽  
Yong-Qing QI ◽  
Yin-Cui HU ◽  
Yu-Cui ZHANG ◽  
Cheng-Ben WU ◽  
...  
Keyword(s):  
Land Use ◽  
Driving Forces ◽  
Landscape Patterns

scholarly journals Autonomous Identification and Positioning of Trucks during Collaborative Forage Harvesting

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1166
Author(s):  
Wei Zhang ◽  
Liang Gong ◽  
Suyue Chen ◽  
Wenjie Wang ◽  
Zhonghua Miao ◽  
...  
Keyword(s):  
Field Experiments ◽  
Absolute Error ◽  
Identification Accuracy ◽  
Depth Image ◽  
Dynamic Identification ◽  
Random Sample Consensus ◽  
Harvesting Efficiency ◽  
Value Decomposition ◽  
Forage Harvester ◽  
Ransac Algorithm

In the process of collaborative operation, the unloading automation of the forage harvester is of great significance to improve harvesting efficiency and reduce labor intensity. However, non-standard transport trucks and unstructured field environments make it extremely difficult to identify and properly position loading containers. In this paper, a global model with three coordinate systems is established to describe a collaborative harvesting system. Then, a method based on depth perception is proposed to dynamically identify and position the truck container, including data preprocessing, point cloud pose transformation based on the singular value decomposition (SVD) algorithm, segmentation and projection of the upper edge, edge lines extraction and corner points positioning based on the Random Sample Consensus (RANSAC) algorithm, and fusion and visualization of results on the depth image. Finally, the effectiveness of the proposed method has been verified by field experiments with different trucks. The results demonstrated that the identification accuracy of the container region is about 90%, and the absolute error of center point positioning is less than 100 mm. The proposed method is robust to containers with different appearances and provided a methodological reference for dynamic identification and positioning of containers in forage harvesting.

scholarly journals Wake-foil interactions and energy harvesting efficiency in tandem oscillating foils

2021 ◽  
Vol 6 (7) ◽  
Author(s):  
Bernardo Luiz R. Ribeiro ◽  
Yunxing Su ◽  
Quentin Guillaumin ◽  
Kenneth S. Breuer ◽  
Jennifer A. Franck
Keyword(s):  
Energy Harvesting ◽  
Harvesting Efficiency ◽  
Energy Harvesting Efficiency ◽  
Oscillating Foils

scholarly journals Ultrafast Electron/Energy Transfer and Intersystem Crossing Mechanisms in BODIPY-Porphyrin Compounds

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 312
Author(s):  
Yusuf Tutel ◽  
Gökhan Sevinç ◽  
Betül Küçüköz ◽  
Elif Akhuseyin Yildiz ◽  
Ahmet Karatay ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Fluorescence Spectra ◽  
Visible Region ◽  
Energy Transfer Mechanism ◽  
Free Base ◽  
Pump Probe ◽  
Harvesting Efficiency ◽  
Probe Spectroscopy ◽  
Absorption Features ◽  
Transfer Mechanisms

Meso-substituted borondipyrromethene (BODIPY)-porphyrin compounds that include free base porphyrin with two different numbers of BODIPY groups (BDP-TTP and 3BDP-TTP) were designed and synthesized to analyze intramolecular energy transfer mechanisms of meso-substituted BODIPY-porphyrin dyads and the effect of the different numbers of BODIPY groups connected to free-base porphyrin on the energy transfer mechanism. Absorption spectra of BODIPY-porphyrin conjugates showed wide absorption features in the visible region, and that is highly valuable to increase light-harvesting efficiency. Fluorescence spectra of the studied compounds proved that BODIPY emission intensity decreased upon the photoexcitation of the BODIPY core, due to the energy transfer from BODIPY unit to porphyrin. In addition, ultrafast pump-probe spectroscopy measurements indicated that the energy transfer of the 3BDP-TTP compound (about 3 ps) is faster than the BDP-TTP compound (about 22 ps). Since the BODIPY core directly binds to the porphyrin unit, rapid energy transfer was seen for both compounds. Thus, the energy transfer rate increased with an increasing number of BODIPY moiety connected to free-base porphyrin.

scholarly journals Persistence of the Swiss Needle Cast Outbreak in Oregon Coastal Douglas-Fir and New Insights from Research and Monitoring

2021 ◽  
Author(s):  
David C Shaw ◽  
Gabriela Ritóková ◽  
Yung-Hsiang Lan ◽  
Doug B Mainwaring ◽  
Andrew Russo ◽  
...  
Keyword(s):  
Climate Change ◽  
Regional Scale ◽  
Emerging Diseases ◽  
Douglas Fir ◽  
Landscape Patterns ◽  
Needle Cast ◽  
Plantation Management ◽  
Environmental Controls ◽  
Swiss Needle Cast ◽  
Improvement Programs

Abstract Swiss needle cast (SNC), caused by Nothophaeocryptopus gaeumannii, is a foliage disease of Douglas-fir (Pseudotsuga menziesii), that reduces growth in native stands and exotic plantations worldwide. An outbreak of SNC began in coastal Oregon in the mid-1990s and has persisted since that time. Here we review the current state of knowledge after 24 years of research and monitoring, with a focus on Oregon, although the disease is significant in coastal Washington and has recently emerged in southwestern British Columbia. We present new insights into SNC distribution, landscape patterns, disease epidemiology and ecology, host-pathogen interactions, trophic and hydrologic influences, and the challenges of Douglas-fir plantation management in the presence of the disease. In Oregon, the SNC outbreak has remained geographically contained but has intensified. Finally, we consider the implications of climate change and other recently emerged foliage diseases on the future of Douglas-fir plantation management. Study Implications: Douglas-fir tree growers need to consider Swiss needle cast (SNC) and other emerging foliage diseases as SNC has not abated over the past 24 years, and along with other emerging diseases, it continues to pose a threat to Douglas-fir plantation productivity. Douglas-fir management in western Oregon remains important, such that a knowledge of disease impacts and effective silvicultural responses is key. Managers should carefully consider whether alternative species may be ecologically or economically beneficial in some situations while tree improvement programs must continue to breed for tolerance to SNC. Research shows that regional scale foliage disease outbreaks can result in trophic cascades and hydrologic changes that affects more than just the trees. The environmental controls on the SNC epidemic imply that climate change could strongly influence future directions of the outbreak, with the greatest threats to trees at higher elevations.

scholarly journals Setting the Flow Accumulation Threshold Based on Environmental and Morphologic Features to Extract River Networks from Digital Elevation Models

2021 ◽  
Vol 10 (3) ◽  
pp. 186
Author(s):  
HuiHui Zhang ◽  
Hugo A. Loáiciga ◽  
LuWei Feng ◽  
Jing He ◽  
QingYun Du
Keyword(s):  
Spatial Scales ◽  
Digital Elevation Models ◽  
Regional Scale ◽  
Drainage Density ◽  
River Network ◽  
Landscape Patterns ◽  
Estimation Methods ◽  
River Networks ◽  
Flow Accumulation ◽  
Digital Elevation

Determining the flow accumulation threshold (FAT) is a key task in the extraction of river networks from digital elevation models (DEMs). Several methods have been developed to extract river networks from Digital Elevation Models. However, few studies have considered the geomorphologic complexity in the FAT estimation and river network extraction. Recent studies estimated influencing factors’ impacts on the river length or drainage density without considering anthropogenic impacts and landscape patterns. This study contributes two FAT estimation methods. The first method explores the statistical association between FAT and 47 tentative explanatory factors. Specifically, multi-source data, including meteorologic, vegetation, anthropogenic, landscape, lithology, and topologic characteristics are incorporated into a drainage density-FAT model in basins with complex topographic and environmental characteristics. Non-negative matrix factorization (NMF) was employed to evaluate the factors’ predictive performance. The second method exploits fractal geometry theory to estimate the FAT at the regional scale, that is, in basins whose large areal extent precludes the use of basin-wide representative regression predictors. This paper’s methodology is applied to data acquired for Hubei and Qinghai Provinces, China, from 2001 through 2018 and systematically tested with visual and statistical criteria. Our results reveal key local features useful for river network extraction within the context of complex geomorphologic characteristics at relatively small spatial scales and establish the importance of properly choosing explanatory geomorphologic characteristics in river network extraction. The multifractal method exhibits more accurate extracting results than the box-counting method at the regional scale.

scholarly journals Potential for Mycorrhizae-Assisted Phytoremediation of Phosphorus for Improved Water Quality

2020 ◽  
Vol 18 (1) ◽  
pp. 7
Author(s):  
Jessica A. Rubin ◽  
Josef H. Görres
Keyword(s):  
Water Quality ◽  
Animal Health ◽  
Phosphorus Uptake ◽  
Agricultural Practices ◽  
Fold Increase ◽  
Landscape Patterns ◽  
Cyanobacterial Blooms ◽  
Terrestrial Plants ◽  
Source Reduction ◽  
Water Ecosystems

During this 6th Great Extinction, freshwater quality is imperiled by upland terrestrial practices. Phosphorus, a macronutrient critical for life, can be a concerning contaminant when excessively present in waterways due to its stimulation of algal and cyanobacterial blooms, with consequences for ecosystem functioning, water use, and human and animal health. Landscape patterns from residential, industrial and agricultural practices release phosphorus at alarming rates and concentrations threaten watershed communities. In an effort to reconcile the anthropogenic effects of phosphorus pollution, several strategies are available to land managers. These include source reduction, contamination event prevention and interception. A total of 80% of terrestrial plants host mycorrhizae which facilitate increased phosphorus uptake and thus removal from soil and water. This symbiotic relationship between fungi and plants facilitates a several-fold increase in phosphorus uptake. It is surprising how little this relationship has been encouraged to mitigate phosphorus for water quality improvement. This paper explores how facilitating this symbiosis in different landscape and land-use contexts can help reduce the application of fertility amendments, prevent non-point source leaching and erosion, and intercept remineralized phosphorus before it enters surface water ecosystems. This literature survey offers promising insights into how mycorrhizae can aid ecological restoration to reconcile humans’ damage to Earth’s freshwater. We also identify areas where research is needed.

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