scholarly journals Generalization of Foraging Experience Biases Bees Toward Flowers With Complex Morphologies

2021 ◽  
Vol 9 ◽  
Author(s):  
Shivani Krishna ◽  
Tamar Keasar

The importance of pollinators as selective agents for many floral traits is well established, but understanding their role in the evolution of complex floral shapes remains challenging. This is because pollinators often need much practice to efficiently handle morphologically complex flowers and extract their food rewards. What induces foragers to persistently visit and pollinate complex flowers despite their initial low profitability? We previously found that naive bumblebees, and unsuccessful feeding attempts of experienced ones, contribute to the pollination of complex flowers. Here we tested a complementary hypothesis, positing that successful foraging on flowers of one complex shape prepares pollinators to visit other species of different complex morphologies. We trained bumblebees to computer-controlled artificial flowers that were either simple, complex or both simple and complex. We then recorded their feeding choices and handling times on a second array of simple and complex flowers that had different shapes and required another handling technique. Bees trained on a single flower type (whether simple or complex) preferred flowers of the same type in the testing array. The foragers’ preferences after training on both flower types depended on the reward schedule during training: when both flower types rewarded equally, simple flowers were preferred at the test phase; when complex flowers provided higher reward during training, they became the preferred flower type during testing. These results suggest that successful foraging on complex flowers, especially when highly rewarding, can indeed induce insect pollinators to attempt additional flower species with other complex shapes.

2013 ◽  
Vol 21 (2) ◽  
pp. 101-104
Author(s):  
Ju Chean Hwang ◽  
◽  
Young Don Chin ◽  
Yong Mo Chung ◽  
Byeong Jeong Lee
Keyword(s):  

Robotica ◽  
1995 ◽  
Vol 13 (5) ◽  
pp. 499-506 ◽  
Author(s):  
M. A. Rodrigues ◽  
Y. E. Li ◽  
M. H. Lee ◽  
J. J. Rowland

SummaryThis paper aims at contributing to a sub-symbolic, feedback-based “theory of robotic grasping” where no full geometrical knowledge of the shape is assumed. We describe experimental results on grasping 2D generic shapes without traditional geometrical processing. Grasping algorithms are used in conjunction with a vision system and a robot manipulator with a three-fingered gripper is used to grasp several different shapes. The altorithms are run on the shape as it appears on the computer screen (i.e. directly from a vision system). Simulated gripper ringer with virtual sensors are configured and positioned on the screen whose inputs are controlled by moving their position relative to the image until an equilibrium is reached among the control systems involved.


Author(s):  
Raed T. Aldahdooh ◽  
Wesam Ashour

Abstract Clustering is widely used to explore and understand large collections of data. K-means clustering method is one of the most popular approaches due to its ease of use and simplicity to implement. This paper introduces Density-based Split- and -Merge K-means clustering Algorithm (DSMK-means), which is developed to address stability problems of standard K-means clustering algorithm, and to improve the performance of clustering when dealing with datasets that contain clusters with different complex shapes and noise or outliers. Based on a set of many experiments, this paper concluded that developed algorithms “DSMK-means” are more capable of finding high accuracy results compared with other algorithms especially as they can process datasets containing clusters with different shapes, densities, or those with outliers and noise.


2006 ◽  
Vol 5 (4) ◽  
pp. 363-367 ◽  
Author(s):  
Takashi Onozaki ◽  
Tsutomu Yoshinari ◽  
Tadahisa Yoshimura ◽  
Masafumi Yagi ◽  
Satoshi Yoshioka ◽  
...  

HortScience ◽  
2009 ◽  
Vol 44 (2) ◽  
pp. 250-255 ◽  
Author(s):  
Guo-Gui Ning ◽  
Xue-Ping Shi ◽  
Hui-Rong Hu ◽  
Yan Yan ◽  
Man-Zhu Bao

A set of Petunia hybrida plants encompassing a range of ploidy levels was developed through colchicine-mediated induction of chromosome doubling. The resulting double-flower tetraploid plants were cross-hybridized with inbred single-flower diploid lines to generate F1 populations with segregation for ploidy level and flower type. The initial in vivo application of colchicine to seedling apical tips produced mixoploid plants of petunia at a high rate of efficiency. Thus, 95% of the shoot tips treated with colchicine for 48 h resulted in polyploid mutant plants, and no difference in this efficiency was observed using concentrations of colchicine between 0.2 and 2.0 mg·mL−1. Of the polyploid plants, 10% were found to be tetraploid and 85% were mixoploid (chimeric). Compared with their diploid counterparts, polyploid plants underwent reduced elongation growth during the first 2 weeks and had thicker stems and shorter internodes resulting in dwarfing of the whole plant. In extreme cases, very slow growth rates produced stunted plantlets. Polyploid plants also had larger, thicker leaves and, in some cases, the leaves that developed after 1 month of growth appeared seriously malformed. Octoploid plants were also obtained and these tended to have more extreme phenotypes. Pure tetraploid plants of double-flower petunia were isolated by the in vitro culture of explants from the initial chimeric tetraploid mutants. These were crossed with three inbred single-flower diploid lines (S1, S2, and S3) thereby generating F1 populations that showed segregation for flower type and ploidy level and included the generation of triploid plants. In the tetraploid plants, flower diameter and the number of flower petals were not changed significantly (P > 0.05) compared with the original diploid double-flower plants, but observation of the pollen grains revealed segregation for size consistent with the increased ploidy level. Analysis of the F1 progeny plants also indicated that chromosome number is not necessary but sufficient to cause the production of semidouble-flowered plants. Flower color and flower diameter were also analyzed in the F1 progeny and complex patterns of inheritance were inferred. In addition to single and double flowers, semidouble-flowered plants were also suggested to be generated by the hybridization of 2n or 3n pollen from the double-flower tetraploid plants with the single-flower diploid lines.


2012 ◽  
Vol 30 (1) ◽  
pp. 101-105 ◽  
Author(s):  
Jin-Hee Lim ◽  
Hak-Ki Shin ◽  
Sang-Kun Park ◽  
Hae-Ryong Cho ◽  
Hye-Kyung Rhee ◽  
...  

1985 ◽  
Vol 107 (4) ◽  
pp. 343-348 ◽  
Author(s):  
M. A. Fugelso

Recently developed computer-controlled twist drill grinding machines have allowed the production of precisely defined points of widely different shapes. The design methodology used for these machines has yielded machines that have up to seven separate axes. This paper shows that in a machine where all the axes can move simultaneously only two rotations and one translation are required to grind drill points. The design methodology employed in this paper uses modern matrix kinematic methods. The kinematic equations developed are simple enough to be solved iteratively on a desktop computer. In addition, the requirement to preset the drill in the drill holder with a fixture is eliminated in this machine.


2021 ◽  
Vol 22 (7) ◽  
Author(s):  
Saifudin SAIFUDIN ◽  
Syalwa Shafira ◽  
Astari Dwiranti ◽  
Andi Salamah

Abstract. Saifudin, Shafira S, Dwiranti A, Salamah A. 2021. Short Communication: Analysis of the chromosome numbers of Zinnia elegans Jacq. in single, double, and pom-pom flowers. Biodiversitas 22: 2771-2777. Zinnia elegans Jacq. is highly valued as an ornamental plant with a variety of flower colors, sizes, and shapes. Polyploidization has been reported in Z. elegans with pom-pom flowers, nevertheless, the variation in chromosome numbers of various flower shapes has yet to be investigated. This study aimed to analyze the chromosome numbers of Z. elegans Jacq. cultivar “California Giant,” “Lilliput,” and “Cactus Flowered Mix” with single, double, and pom-pom flowers to determine their variations and identify the morphology of the flowers. Chromosomes were prepared using the squashing method, and images were analyzed using the Chromosome Image Analyzing System (CHIAS) IV. The minimum of 5 slides was prepared for each flower type from each cultivar. The results show that the three cultivars are diploid plants (2n = 24) with varying flower morphology. The single and double flowers of Z. elegans “Lilliput” and the single flower of “Cactus Flowered Mix” showed no variation in chromosome numbers. In contrast, chromosome number variation was found in the pom-pom flower of Z. elegans “California Giant” (2n = 22, 24, 48) and the double flower of “Cactus Flowered Mix” (2n = 9, 13, 15, 24). Two cultivars, Z. elegans “California Giant” and Z. elegans “Cactus Flowered Mix,” were successfully analyzed using CHIAS IV. Statistical analysis using a t-test (? = 0.05) showed that the total chromosome length of Z. elegans “California Giant” (2n = 24) was significantly greater than that of Z. elegans “Cactus Flowered Mix” (2n = 24). Chromosome satellites were found in both cultivars.


Author(s):  
Rajkumar Velu ◽  
Sarat Singamneni

Polymethylmethacrylate (PMMA) is a synthetic resin, widely used for bio-medical applications and is usually mixed with some other ingredients to form a soft substrate, which gradually hardens. Medical implants and other products of different shapes are generated either by moulding while it is still soft or by machining further to hardening. While these methods limit the freedom to achieve the much needed geometrical complexities, porosity also gets adversely affected. Rapid prototyping or additive manufacturing techniques allow for complex shapes to be easily produced together with a degree of control over the porosity. Though fused deposition modelling was attempted earlier with PMMA, more promising approaches such as selective laser sintering attained very little attention in this regard. In particular, the mechanism of material consolidation and the effects of significant process parameters on critical responses need sufficient attention, and this paper attempts this by experimental means.


2021 ◽  
Author(s):  
Amy S. Harrison ◽  
Sean A. Rands

Flowers produce local humidity that is often greater than that of the surrounding environment, and studies have shown that insect pollinators may be able to use this humidity difference to locate and identify suitable flowers. However, environmental humidity is highly heterogeneous, and is likely to affect the detectability of floral humidity, potentially constraining the contexts in which it can be used as a salient communication pathway between plants and their pollinators. In this study, we use differential conditioning techniques on bumblebees Bombus terrestris audax (Harris) to explore the detectability of an elevated floral humidity signal when presented against different levels of environmental noise. Artificial flowers were constructed that could be either dry or humid, and individual bumblebees were presented with consistent rewards in either the humid or dry flowers presented in an environment with four levels of constant humidity, ranging from low (~20% RH) to highly saturated (~95% RH). Ability to learn was dependent upon both the rewarding flower type and the environment: the bumblebees were able to learn rewarding dry flowers in all environments, but their ability to learn humid rewarding flowers was dependent on the environmental humidity, and they were unable to learn humid rewarding flowers when the environment was highly saturated. This suggests that floral humidity might be masked from bumblebees in humid environments, suggesting that it may be a more useful signal to insect pollinators in arid environments.


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