Controlling Purple Jewelweed (Impatiens glandulifera): Assessment of Feasibility and Costs

2017 ◽  
Vol 10 (3) ◽  
pp. 254-261
Author(s):  
Michaël Leblanc ◽  
Claude Lavoie
Keyword(s):  
Riparian Vegetation ◽  
Stem Density ◽  
Impatiens Glandulifera ◽  
Work Time ◽  
Exotic Invasive Species ◽  
Exotic Invasive ◽  
Time Required ◽  
Density And Biomass ◽  
The Relationship ◽  
Control Campaign

We experimentally tested the feasibility of a control campaign of purple jewelweed (Impatiens glandulifera), an exotic invasive species in Europe and North America. We evaluated the amount of time and money required to control the plant along riverbanks, with particular attention paid to the recovery of riparian vegetation following hand pulling and bagging. Work time was directly and significantly related to stem density and fresh biomass of the invader, but the relationship was stronger for density. Density and biomass were strongly reduced by the first hand-pulling operation from a mean of 45 to 2 stems m−2 and from a mean of 0.95 kg m−2 to nearly zero, a good performance but not enough to negate the need for a second hand pulling later in the summer. A single hand pulling significantly reduced the cover of purple jewelweed from to 30% to 7%. Riparian vegetation disturbed by the first hand pulling largely recovered during the following 30 d. Expressed over an area of 1 ha, the total amount of time required to control purple jewelweed is 1,400 work hours over 2 yr, or a minimum investment of Can$21,000 (US$17,000). Although controlling a well-established purple jewelweed population is expensive, to properly evaluate the benefits, we must also consider the costs of soil erosion caused by this species.

scholarly journals Influence of Features on Accuracy of Anomaly Detection for an Energy Trading System

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4237
Author(s):  
Hoon Ko ◽  
Kwangcheol Rim ◽  
Isabel Praça
Keyword(s):  
Anomaly Detection ◽  
Real Time ◽  
Feature Detection ◽  
Trading System ◽  
Judgment Accuracy ◽  
Energy Trading ◽  
Real Time Processing ◽  
Detection Model ◽  
Time Required ◽  
The Relationship

The biggest problem with conventional anomaly signal detection using features was that it was difficult to use it in real time and it requires processing of network signals. Furthermore, analyzing network signals in real-time required vast amounts of processing for each signal, as each protocol contained various pieces of information. This paper suggests anomaly detection by analyzing the relationship among each feature to the anomaly detection model. The model analyzes the anomaly of network signals based on anomaly feature detection. The selected feature for anomaly detection does not require constant network signal updates and real-time processing of these signals. When the selected features are found in the received signal, the signal is registered as a potential anomaly signal and is then steadily monitored until it is determined as either an anomaly or normal signal. In terms of the results, it determined the anomaly with 99.7% (0.997) accuracy in f(4)(S0) and in case f(4)(REJ) received 11,233 signals with a normal or 171anomaly judgment accuracy of 98.7% (0.987).

scholarly journals Impact of an Exotic Invasive Pest, Spodoptera frugiperda (Lepidoptera: Noctuidae), on Resident Communities of Pest and Natural Enemies in Maize Fields in Kenya

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1074
Author(s):  
Bonoukpoè Mawuko Sokame ◽  
Boaz Musyoka ◽  
Julius Obonyo ◽  
François Rebaudo ◽  
Elfatih M. Abdel-Rahman ◽  
...  
Keyword(s):  
Natural Enemies ◽  
Spodoptera Frugiperda ◽  
Fall Armyworm ◽  
Invasive Pest ◽  
Growth Stages ◽  
Insect Communities ◽  
Exotic Invasive Species ◽  
Before And After ◽  
Exotic Invasive ◽  
Lepidoptera Noctuidae

The interactions among insect communities influence the composition of pest complexes that attack crops and, in parallel, their natural enemies, which regulate their abundance. The lepidopteran stemborers have been the major maize pests in Kenya. Their population has been regulated by natural enemies, mostly parasitoids, some of which have been used for biological control. It is not known how a new exotic invasive species, such as the fall armyworm (FAW), Spodoptera frugiperda (Lepidoptera, Noctuidae), may affect the abundance and parasitism of the resident stemborers. For this reason, pest and parasitism surveys have been conducted, before and after the FAW invaded Kenya, in maize fields in 40 localities across 6 agroecological zones (AEZs) during the maize-growing season, as well as at 3 different plant growth stages (pre-tasseling, reproductive, and senescence stages) in 2 elevations at mid-altitude, where all maize stemborer species used to occur together. Results indicated that the introduction of the FAW significantly correlated with the reduction of the abundance of the resident communities of maize stemborers and parasitoids in maize fields; moreover, the decrease of stemborer density after the arrival of FAW occurred mostly at both reproductive and senescent maize stages. It also suggests a possible displacement of stemborers by FAW elsewhere; for example, to other cereals. However, since this study was conducted only three years after the introduction of the FAW, further studies will need to be conducted to confirm such displacements.

Response of Deeproot Sedge (Cyperus entrerianus) to Herbicide and Prescribed Fire in Texas Coastal Prairie

2015 ◽  
Vol 8 (1) ◽  
pp. 15-31 ◽  
Author(s):  
Jonathan R. King ◽  
Andrew J. Bennett ◽  
Warren C. Conway ◽  
David J. Rosen ◽  
Brian P. Oswald
Keyword(s):  
Prescribed Fire ◽  
Treatment Options ◽  
Rapid Expansion ◽  
Coastal Prairie ◽  
Multiple Treatment ◽  
Exotic Invasive Species ◽  
Plant Groups ◽  
Exotic Invasive ◽  
Dormant Season ◽  
In Fire

AbstractIntroduced accidentally from South America, deeproot sedge is rapidly expanding in a variety of habitats throughout the southeastern United States. Of particular concern is its rapid expansion, naturalization, and formation of monocultures in Texas coastal prairie, one of the most imperiled temperate ecoregions in North America. The objective of this research was to examine how deeproot sedge responds to prescribed fire, to the herbicide imazapic, and to treatment combinations of both. Combinations of prescribed fire and imazapic treatments and imazapic-only treatments effectively reduced deeproot sedge cover and frequency. However, plots exposed to dormant season fires (with no imazapic) had greater deeproot sedge cover after burn treatments were applied, indicating that coastal prairie management using only dormant season prescribed fire will not work toward reduction or management of this exotic invasive species. Although deeproot sedge cover was often reduced in fire–imazapic treatment combinations, it was still present in treatment plots. Moreover, desirable functional plant groups (i.e., native bunchgrasses) did not respond positively to the fire–imazapic treatments, but in some instances, woody plant coverage increased. Repeated, long-term approaches using integrated and coordinated efforts with multiple treatment options will be necessary to restore community structure to desired compositional levels. Such integrated approaches should be effective in reducing deeproot sedge frequency, cover, and extent to more manageable levels throughout its introduced geographic range.

Understanding Learning Environments, Personality, and Proctoring During Mandatory Remote Delivery

2021 ◽  
Vol 65 (1) ◽  
pp. 767-770
Author(s):  
Nancy J. Stone
Keyword(s):  
Online Learning ◽  
Online Education ◽  
Learning Environments ◽  
Online Survey ◽  
Campus Housing ◽  
Learning Success ◽  
Time Required ◽  
Relationship Of ◽  
The Impact ◽  
The Relationship

To evaluate students’ online learning environments, the relationship between personality and online learning success, and students’ perceptions about online proctoring during mandatory remote delivery due to the pandemic, students responded to an online survey. Learning environments generally included houses and rarely included on-campus housing. The specific room type was predominantly the bedroom. Only conscientiousness was related positively to anticipated semester GPA. The positive relationship between anticipated and overall GPA supports the notion that more conscientious students tend to be successful in online learning situations, as online education was rated as slightly ineffective. A majority of students did not see a need for online proctoring due to the inability or time required to search for materials, which would only harm one’s performance. There is a need to research further the impact of the study environment, relationship of the students’ personality to learning success, and consequences of online proctoring during remote learning.

scholarly journals Characterizing and Mitigating Work Time Inflation in Task Parallel Programs

2013 ◽  
Vol 21 (3-4) ◽  
pp. 123-136 ◽  
Author(s):  
Stephen L. Olivier ◽  
Bronis R. de Supinski ◽  
Martin Schulz ◽  
Jan F. Prins
Keyword(s):  
Poor Performance ◽  
Data Access ◽  
Parallel Applications ◽  
Task Parallelism ◽  
Improve Performance ◽  
Additional Time ◽  
Work Time ◽  
Task Parallel ◽  
Time Required ◽  
Data Access Latency

Task parallelism raises the level of abstraction in shared memory parallel programming to simplify the development of complex applications. However, task parallel applications can exhibit poor performance due to thread idleness, scheduling overheads, andwork time inflation– additional time spent by threads in a multithreaded computation beyond the time required to perform the same work in a sequential computation. We identify the contributions of each factor to lost efficiency in various task parallel OpenMP applications and diagnose the causes of work time inflation in those applications. Increased data access latency can cause significant work time inflation in NUMA systems. Our locality framework for task parallel OpenMP programs mitigates this cause of work time inflation. Our extensions to the Qthreads library demonstrate that locality-aware scheduling can improve performance up to 3X compared to the Intel OpenMP task scheduler.

scholarly journals Quantifying the Feeding Periods Required by Corn Flea Beetles to Acquire and Transmit Pantoea stewartii

Plant Disease ◽  
2006 ◽  
Vol 90 (3) ◽  
pp. 319-324 ◽  
Author(s):  
B. Menelas ◽  
C. C. Block ◽  
P. D. Esker ◽  
F. W. Nutter
Keyword(s):  
Nalidixic Acid ◽  
Growth Models ◽  
Flea Beetle ◽  
Feeding Time ◽  
Feeding Period ◽  
Selective Media ◽  
Pantoea Stewartii ◽  
Flea Beetles ◽  
Time Required ◽  
The Relationship

The feeding periods required by corn flea beetles to acquire and transmit Pantoea stewartii were investigated in the Stewart's disease of corn pathosystem. To quantify the effect of acquisition feeding period on percentage of acquisition, field-collected corn beetles were allowed to feed for 6, 12, 24 36, 48, and 72 h on corn seedlings previously inoculated with a rifampicin- and nalidixic acid-restraint strain of P. stewartii. Acquisition of P. stewartii by corn flea beetles was considered positive if the rifampicin- and nalidixic acid-marked strain was recovered on selective media. To quantity the effect of transmission feeding period on percent transmission of P. stewartii by corn flea beetles, P. stewartii- infested corn flea beetles were allowed to feed on healthy corn seedlings for periods of 3, 6, 12, 24, 36, 48, and 72 h. After the appropriate transmission feeding period, leaf tissues surrounding the sites of feeding scars were cultured for the presence of the P. stewartii-marked strain. Transmission of P. stewartii was considered positive if the marked strain was recovered on selective media. Acquisition of P. stewartii occurred within 6 h and the percentage of corn flea beetles that had acquired P. stewartii after 72 h ranged from 68 to 94%. The change in P. stewartii acquisition by corn flea beetles (Y) with respect to acquisition feeding period (X) was best described by the Gompertz model, with R2 values ranging from 91 to 99%. The mean time for acquisition by 50% of the corn flea beetles was 36.5 ± 11.6 h. The minimum transmission feeding time required for corn flea beetles to transmit P. stewartii following a 48-h acquisition feeding period was less than 3 h. The percent transmission of P. stewartii by corn flea beetles was nearly 100% after a 48-h transmission feeding period and was 100% by 72 h. Among population growth models evaluated, the monomolecular model best described the relationship between percent transmission (Y) and transmission feeding periods (X), with R 2 values of up to 84%. However, a nonlinear form of the monomolecular model better quantified the relationship between percent transmission and transmission feeding period, because pseudo-R2 values ranged between 98.1 and 99.5%. The predicted transmission feeding time required for 50% of P. stewartii-infested corn flea beetles to transmit the pathogen was 7.6 ± 0.87 h. These results suggest that the corn flea beetle is a highly efficient vector that can quickly acquire and transmit P. stewartii, thereby requiring insecticide seed treatments and foliar insecticides that act quickly to prevent corn flea beetles from acquiring and transmitting P. stewartii to corn plants.

scholarly journals Cuttings of Lippia alba with emphasis on time for seedling formation, substrates and plant growth regulators

2015 ◽  
Vol 33 (2) ◽  
pp. 230-235 ◽  
Author(s):  
Cristina B Lima ◽  
Ana C Boaventura ◽  
Marli M Gomes
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Dry Mass ◽  
Mineral Fertilizers ◽  
Shoot Height ◽  
Lippia Alba ◽  
Statistical Designs ◽  
Time Required ◽  
The Relationship

We aimed to establish the period of time required for seedlings formation, as well as to evaluate the effect of substrates and plant growth regulators in cuttings of L. alba. Three experiments were performed, with statistical designs chosen according to each test objectives. Rooting (%), shoot height (cm), longest root length (cm), leaves number, fresh and dry matter masses (g), were analyzed. The absolute rate of shoot and root system growth, together with the relationship between dry mass of roots and shoots were efficient in predicting the period of greatest speed and accumulation of organic matter in plants. The plant growth regulators favored the vegetative performance of seedlings, with better development 30 days after the cuttings containing mineral fertilizers, vermicompost, clay soil and sand commercially known as 'medium sand'.

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