Flowering period, thermogenesis, and pattern of visiting insects in Arisaema triphyllum (Araceae) in Quebec

Botany ◽  
2009 ◽  
Vol 87 (3) ◽  
pp. 324-329 ◽  
Author(s):  
Isabelle Barriault ◽  
Marc Gibernau ◽  
Denis Barabé
Keyword(s):  
Weather Conditions ◽  
Flowering Period ◽  
Eastern United States ◽  
Floral Trait ◽  
Male And Female ◽  
Arisaema Triphyllum ◽  
Significant Temperature ◽  
Variable Weather ◽  
Insect Visitors ◽  
Forest Herb

Jack-in-the-Pulpit ( Arisaema triphyllum (L.) Torr.) is a perennial forest herb of southern Canada and the eastern United States. The flowering periods of male and female inflorescences in relation to the temperature of the inflorescence and the activity pattern of visiting insects were studied in one population in western Montreal Island (Quebec, Canada). The flowering period of A. triphyllum was long (20 d in male and female plants), which is unusual in temperate Aroideae. This floral trait could have evolved secondarily as an adaptation to increase pollination efficiency under highly variable weather conditions at high latitude. In male and female plants, no significant temperature increase of the appendix was recorded. The warming effect of sunlight during the day could be sufficient for the emission of the attractive odour. Two Dipteran families, the Mycetophilidae and the Cecidomyiidae, were the most frequent insect visitors of A. triphyllum. Our observations showed that odour production is linked with the pollination activity beginning with insect visits.

scholarly journals VISIBILITY MONITORING USING MOBILE APPLICATION

2018 ◽  
Vol XLII-5 ◽  
pp. 883-891
Author(s):  
S. Purohit ◽  
P. Chauhan
Keyword(s):  
Mobile Application ◽  
Smart Phone ◽  
Quantitative Measure ◽  
Weather Conditions ◽  
Optical Instruments ◽  
Important Concern ◽  
Transport Safety ◽  
Continuous Power ◽  
Variable Weather ◽  
Solar Position

<p><strong>Abstract.</strong> Visibility is clarity with which the distant objects are perceived in the atmosphere with the naked eye. Visibility monitoring is an important concern in health, environment and transport safety context. Quantitative measures of visibility are increasingly becoming important in various areas as they are representative of the particles present in the environment that causes degradation of the visibility. Existing techniques of visibility estimation employ human observers, optical instruments, chemical sensors or combination of some of them. These techniques suffer from poor spatial and temporal resolution, high cost of installation and maintenance, need of specialized personnel, continuous power supply requirement and difficulty in portability. We propose a smart phone-based visibility monitoring system which estimates air visibility/quality in terms of a quantitative measure: Turbidity. In principle, the application calculates turbidity as difference of intensity of captured sky image and analytical value of sky luminance obtained by implementing Perez model. The estimated turbidity tagged with date, time, location, solar position and luminance is sent to the backend server generating consolidated database for mapping of turbidity and generating various analytical reports. The application can easily be deployed to be used by large number of people facilitating citizen science. The results from application were validated against the observations from SAFAR INDIA application at different stations in Ahmedabad, dates and under variable weather conditions.</p>

scholarly journals Stress-resilient maize for climate-vulnerable ecologies in the Asian tropics

2020 ◽  
pp. 1264-1274
Author(s):  
P.H. Zaidi ◽  
Thanh Nguyen ◽  
Dang N. Ha ◽  
Suriphat Thaitad ◽  
Salahuddin Ahmed ◽  
...  
Keyword(s):  
Climate Change ◽  
Agricultural Research ◽  
Weather Conditions ◽  
Climatic Conditions ◽  
Yield Potential ◽  
Specific Situation ◽  
Environment Interaction ◽  
Maize Germplasm ◽  
Growing Conditions ◽  
Variable Weather

Most parts of the Asian tropics are hotspots of climate change effects and associated weather variabilities. One of the major challenges with climate change is the uncertainty and inter-annual variability in weather conditions as crops are frequently exposed to different weather extremes within the same season. Therefore, agricultural research must strive to develop new crop varieties with inbuilt resilience towards variable weather conditions rather than merely tolerance to individual stresses in a specific situation and/or at a specific crop stage. C4 crops are known for their wider adaptation to range of climatic conditions. However, recent climatic trends and associated variabilities seem to be challenging the threshold limit of wider adaptability of even C4 crops like maize. In collaboration with national programs and private sector partners in the region, CIMMYT-Asia maize program initiated research for development (R4D) projects largely focusing on saving achievable yields across range of variable environments by incorporating reasonable levels of tolerance/resistance to major abiotic and biotic stresses without compromising on grain yields under optimal growing conditions. By integrating novel breeding tools like - genomics, double haploid (DH) technology, precision phenotyping and reducing genotype × environment interaction effects, a new generation of maize germplasm with multiple stress tolerance that can grow well across variable weather conditions were developed. The new maize germplasm were targeted for stress-prone environments where maize is invariability exposed to a range of sub-optimal growing conditions, such as drought, heat, waterlogging and various virulent diseases. The overarching goal of the stress-resilient maize program has been to achieve yield potential with a downside risk reduction.

scholarly journals Hybrid Wind–PV Frequency Control Strategy under Variable Weather Conditions in Isolated Power Systems

2020 ◽  
Vol 12 (18) ◽  
pp. 7750 ◽  
Author(s):  
Ana Fernández-Guillamón ◽  
Guillermo Martínez-Lucas ◽  
Ángel Molina-García ◽  
Jose-Ignacio Sarasua
Keyword(s):  
Renewable Energy ◽  
Power Systems ◽  
Control Strategy ◽  
Rotational Speed ◽  
Power Plants ◽  
Mean Squared Error ◽  
Frequency Control ◽  
Weather Conditions ◽  
Squared Error ◽  
Variable Weather

Over the last two decades, variable renewable energy technologies (i.e., variable-speed wind turbines (VSWTs) and photovoltaic (PV) power plants) have gradually replaced conventional generation units. However, these renewable generators are connected to the grid through power converters decoupled from the grid and do not provide any rotational inertia, subsequently decreasing the overall power system’s inertia. Moreover, the variable and stochastic nature of wind speed and solar irradiation may lead to large frequency deviations, especially in isolated power systems. This paper proposes a hybrid wind–PV frequency control strategy for isolated power systems with high renewable energy source integration under variable weather conditions. A new PV controller monitoring the VSWTs’ rotational speed deviation is presented in order to modify the PV-generated power accordingly and improve the rotational speed deviations of VSWTs. The power systems modeled include thermal, hydro-power, VSWT, and PV power plants, with generation mixes in line with future European scenarios. The hybrid wind–PV strategy is compared to three other frequency strategies already presented in the specific literature, and gets better results in terms of frequency deviation (reducing the mean squared error between 20% and 95%). Additionally, the rotational speed deviation of VSWTs is also reduced with the proposed approach, providing the same mean squared error as the case in which VSWTs do not participate in frequency control. However, this hybrid strategy requires up to a 30% reduction in the PV-generated energy. Extensive detailing of results and discussion can be also found in the paper.

scholarly journals An Automation of Collector Testing and Modification of ANSI/ASHRAE 93-1986 Standard

1990 ◽  
Vol 112 (4) ◽  
pp. 257-267 ◽  
Author(s):  
B. J. Huang ◽  
S. W. Hsieh
Keyword(s):  
Steady State ◽  
Performance Test ◽  
Weather Conditions ◽  
Testing System ◽  
Test Results ◽  
Time Basis ◽  
Variable Weather ◽  
Small Scatter ◽  
Selection Of ◽  
Steady State Performance

The steady-state performance test of solar collectors using ANSI/ASHRAE 93-1986 Standard was revised and an automation for the testing was carried out in the present study in order that the test can be easily performed outdoors in areas with variable weather conditions. It was shown that the 95 percent settling time of the collector τ95 can be adopted as the time basis in the selection of steady-state period for the test. To make the best use of the time available for the testing, the steady-state period defined by ANSI/ASHRAE 93-1986 Standard was changed to the τ95 plus five minutes, or ten minutes, whichever is larger. To reduce scatter uncertainty in the test results, the test period for the efficiency calculation was chosen as the segment of the last five minutes in the steady-state period and a steadiness condition defined statistically was adopted. To shorten the time for each test run a PC-based expert testing system, which is completely automatic and requires no operator, was developed in the present study. Using this expert system associated with the modified ANSI/ASHRAE 93-1986 Standard, we can effectively carry out the collector test at variable weather conditions with small scatter uncertainty and can substantially shorten the duration of a test.

Autogamy, allogamy, and pollination in some Canadian weeds

1972 ◽  
Vol 50 (8) ◽  
pp. 1767-1771 ◽  
Author(s):  
Gerald A. Mulligan
Keyword(s):  
Native Species ◽  
Single Species ◽  
The Self ◽  
Flowering Period ◽  
Perennial Weeds ◽  
Short Period ◽  
Winter Annual ◽  
Annual Weeds ◽  
Allogamous Species ◽  
Insect Visitors

This paper is concerned with insect visitors to some Canadian weeds. It shows that both self-pollinating (autogamous) and cross-pollinating (allogamous) weeds are visited during the flowering period. It was found that self-incompatible species were visited by insects frequently, whereas self-compatible weeds were not visited or were rarely visited. The self-compatible group showed some difference, in that autogamous annual and winter annual weeds were visited less than were autogamous biennial and short-lived perennial weeds. Most of the insect visitors, to both the autogamous and allogamous species of weeds, were native species, whereas the weeds themselves were mostly introduced species. The insects, also, evidently visited more than a single species of plant over a short period of time. The implications of the insect visits to the genetic structure of the plants and their colonizing abilities are then briefly discussed.

A less restrictive technique for the estimation of understory light under variable weather conditions

2007 ◽  
Vol 242 (2-3) ◽  
pp. 800-804 ◽  
Author(s):  
Alain Paquette ◽  
André Bouchard ◽  
Alain Cogliastro
Keyword(s):  
Weather Conditions ◽  
Variable Weather
Sign in / Sign up

Export Citation Format

Share Document