2,215 research outputs found
Development of a Precision Metering System for Pregerminated Seed
Agricultural Engineerin
What is the Real Cost of a Cotton Module Tarp?
6 pp., 5 photos, 1 table, 1 graphCotton that is not well protected from the elements loses quality and value as it waits to be ginned. This publication explains the effect of a good cotton module tarp on turnout, ginning rate and lint value
Blood Parasite Infection Differentially Relates to Carotenoid-Based Plumage and Bill Color in the American Goldfinch
Male and female American goldfinches (Spinus tristis) express condition-dependent carotenoid-based plumage and bill coloration. Plumage color is relatively static, as pigments incorporated into feathers during the spring molt cannot be mobilized thereafter. In contrast, bill color is dynamic, reflecting changes in condition over short time periods. Previous studies have shown that male and female ornaments, though similar in expression, are differentially related to measures of immunocompetence, suggesting that the relationship between ornamentation and parasite infection may differ between the sexes. In this study, we evaluate the relationship between condition-dependent ornamentation (plumage and bill color) and blood parasite infection in male and female American goldfinches. We captured goldfinches after completion of the pre-alternate molt and prior to the onset of nesting and assessed prevalence of Trypanosoma parasites via blood smears. Plumage color strongly predicted trypanosome infection: Birds with more colorful plumage were less likely to present infections. In contrast, we detected no relationship between infection and bill color, which in other studies has been shown to dynamically reflect current condition. Sex did not affect the relationship between infection status and either ornament. Together, these results suggest that physiological pathways linking carotenoid ornamentation and infection may vary even within a single species
The evolutionary stability of attenuators that mask information about animals that social partners can exploit
Signals and cues are fundamental to social interactions. A well-established concept in the study of animal communication is an amplifier, defined as a trait that does not add extra information to that already present in the original cue or signal, but rather enhances the fidelity with which variation in the original cue or signal is correctly perceived. Attenuators as the logical compliment of amplifiers: attenuators act to reduce the fidelity with which variation in a signal or cue can be reliably evaluated by the perceivers. Where amplifiers reduce the effect of noise on the perception of variation, attenuators add noise. Attenuators have been subject to much less consideration than amplifiers, however they will be the focus of our theoretical study. We utilise an extension of a well-established model incorporated signal or cue inaccuracy and costly investments by emitter and perceiver in sending and attending to the signal or cue. We present broad conditions involving some conflict of interest between emitter and perceiver where it may be advantageous for emitters to invest in costly attenuators to mask cues from potential perceivers, and a subset of these conditions where the perceiver may be willing to invest in costly anti-attentuators to mitigate the loss of information to them. We demonstrate that attenuators can be evolutionary stable even if they are costly, even if they are sometimes disadvantageous, and even if a perceiver can mount counter-measures to them. As such, we feel that attenuators of cues may be deserving of much more research attention.PostprintPeer reviewe
Detecting Volunteer Cotton Plants in a Corn Field with Deep Learning on UAV Remote-Sensing Imagery
The cotton boll weevil, Anthonomus grandis Boheman is a serious pest to the
U.S. cotton industry that has cost more than 16 billion USD in damages since it
entered the United States from Mexico in the late 1800s. This pest has been
nearly eradicated; however, southern part of Texas still faces this issue and
is always prone to the pest reinfestation each year due to its sub-tropical
climate where cotton plants can grow year-round. Volunteer cotton (VC) plants
growing in the fields of inter-seasonal crops, like corn, can serve as hosts to
these pests once they reach pin-head square stage (5-6 leaf stage) and
therefore need to be detected, located, and destroyed or sprayed . In this
paper, we present a study to detect VC plants in a corn field using YOLOv3 on
three band aerial images collected by unmanned aircraft system (UAS). The
two-fold objectives of this paper were : (i) to determine whether YOLOv3 can be
used for VC detection in a corn field using RGB (red, green, and blue) aerial
images collected by UAS and (ii) to investigate the behavior of YOLOv3 on
images at three different scales (320 x 320, S1; 416 x 416, S2; and 512 x 512,
S3 pixels) based on average precision (AP), mean average precision (mAP) and
F1-score at 95% confidence level. No significant differences existed for mAP
among the three scales, while a significant difference was found for AP between
S1 and S3 (p = 0.04) and S2 and S3 (p = 0.02). A significant difference was
also found for F1-score between S2 and S3 (p = 0.02). The lack of significant
differences of mAP at all the three scales indicated that the trained YOLOv3
model can be used on a computer vision-based remotely piloted aerial
application system (RPAAS) for VC detection and spray application in near
real-time.Comment: 38 Page
Computer Vision for Volunteer Cotton Detection in a Corn Field with UAS Remote Sensing Imagery and Spot Spray Applications
To control boll weevil (Anthonomus grandis L.) pest re-infestation in cotton
fields, the current practices of volunteer cotton (VC) (Gossypium hirsutum L.)
plant detection in fields of rotation crops like corn (Zea mays L.) and sorghum
(Sorghum bicolor L.) involve manual field scouting at the edges of fields. This
leads to many VC plants growing in the middle of fields remain undetected that
continue to grow side by side along with corn and sorghum. When they reach
pinhead squaring stage (5-6 leaves), they can serve as hosts for the boll
weevil pests. Therefore, it is required to detect, locate and then precisely
spot-spray them with chemicals. In this paper, we present the application of
YOLOv5m on radiometrically and gamma-corrected low resolution (1.2 Megapixel)
multispectral imagery for detecting and locating VC plants growing in the
middle of tasseling (VT) growth stage of cornfield. Our results show that VC
plants can be detected with a mean average precision (mAP) of 79% and
classification accuracy of 78% on images of size 1207 x 923 pixels at an
average inference speed of nearly 47 frames per second (FPS) on NVIDIA Tesla
P100 GPU-16GB and 0.4 FPS on NVIDIA Jetson TX2 GPU. We also demonstrate the
application of a customized unmanned aircraft systems (UAS) for spot-spray
applications based on the developed computer vision (CV) algorithm and how it
can be used for near real-time detection and mitigation of VC plants growing in
corn fields for efficient management of the boll weevil pests.Comment: 39 page
Inter-annual decrease in pulse rate and peak frequency of Southeast Pacific blue whale song types
The decrease in the frequency of two southeast Pacific blue whale song types was examined over decades, usingacoustic data from several different sources ranging between the Equator and Chilean Patagonia. The pulse rate ofthe song units as well as their peak frequency were measured using two different methods (summed auto-correlationand Fourier transform). The sources of error associated with each measurement were assessed. There was a lineardecline in both parameters for the more common song type (southeast Pacific song type n ◦ 2). An abbreviated analysisalso showed a frequency decline in the scarcer southeast Pacific song type n ◦ 1 between 1970 to 2014, revealing thatboth song types are declining at similar rates. We discussed the use of measuring both pulse rate and peak frequencyto examine the frequency decline. Finally, a comparison of the rates of frequency decline with other song typesreported in the literature is presented.La décroissance en fréquence des deux chants de baleine bleue de l'océan pacifique sud est est examiné sur plusieurs décennies en utilisant comme source des données acoustiques de l'Equateur à la Patagonie chilienne. La fréquence de pulsation et la fréquence pic des signaux sont mesurés en utilisant deux méthodes distinctes (auto-corrélation sommée et transformée de Fourier rapide). Les sources d'erreur associées à chaque mesure sont estimées. Il y a un déclin linéaire de ces deux fréquences pour le chant le plus commun de cette zone (chant du Pacifique Sud Est n°2, SEP2). Un analyse plus rapide montre aussi une baisse linéaire, entre 1970 et 2014, de la fréquence du chant SEP1, plus rarement enregistré dans cette zone. Ces deux baisses ont des amplitudes similaires. L'intérêt de mesurer la fréquence de pulsation et la fréquence pic de façon concomitante est estimé. Enfin, une comparaison globale des déclins en fréquence de tous les types de chants de baleines bleues est fournie
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