Foraging Behavior of Anastrepha Ludens, A. obliqua, and A. serpentina in Response to Feces Extracts Containing Host Marking Pheromone

Following oviposition, females of many Tephritid flies deposit host marking pheromones (HMPs) to indicate that the host fruit has been occupied. We describe the foraging behavior of these three economically important species (Anastrepha ludens and A. obliqua from the fraterculus species group and A. serpentina from the serpentina species group) when they encounter an artificial fruit (green agar spheres wrapped in Parafilm) marked with intra- and interspecific feces extracts that contain, among other substances, host marking pheromone. When flies encountered fruit treated with either 1 or 100 mg/ml feces extract, there were drastic and statistically significant reductions in tree residence time, mean time spent on fruit, and in the number of oviposition attempts or actual ovipositions when compared to the control treatment (clean fruit). These responses were almost identical irrespective of extract origin (i.e., fly species), indicating complete interspecific HMP cross-recognition by all three Anastrepha species tested. We discuss the ecological and practical implications of our findings.     

Restricting time at pasture: Effects on dairy cow herbage intake, foraging behavior, hunger-related hormones, and metabolite concentration during the first grazing session

This study investigated the effect of restricting grazing time on circulating concentrations of ghrelin, nonesterified fatty acids (NEFA), and glucose before, and foraging behavior of dairy cows during, the first grazing session of the day (GS, 0800-1200 h). Forty-eight Holstein-Friesian cows (470 ± 47 kg of BW; 35 ± 9 d in milk) were strip-grazed on a perennial ryegrass pasture for either 4 h after each milking (2 × 4), 8 h between milkings (1 × 8), or the 24-h period excluding milking times (CTL). Cows were bled before the GS; plasma was analyzed for ghrelin and serum for glucose and NEFA. Herbage mass was measured pregrazing (0730 h), during and at the end of the GS (1200 h), and postgrazing (24 h after the first measurement). Herbage mass data were fitted to a model to estimate herbage disappearance rates. Herbage intake and bite mass were calculated using herbage mass disappearance and behavioral measurements. Bite rate, eating, searching, ruminating, and idling time were determined during the GS for each cow. No difference in glucose concentration was found between treatments. Concentrations of NEFA and ghrelin were the greatest for cows in the 1 × 8 treatment. Daily herbage intake did not differ between treatments; however, during the GS 1 × 8 had a greater herbage intake than 2 × 4 and CTL. Bite mass differed between treatments and throughout the GS. Bite mass was smallest for CTL during the first 60 min and greatest during the last 90 min, when cows in the 2 × 4 treatment had the smallest bite mass. Cows in 1 × 8 spent the longest time eating and the least time searching and ruminating. Eating time was greatest for 1 × 8 during the first 60 and last 90 min of the GS. Searching time only differed in the second 60 min, when it was the lowest for 1 × 8. Cows from all treatments did not ruminate during the first 120 min. Cows in CTL had the greatest rumination time during the last 90 min. The model fitted to represent dynamics of herbage mass disappearance presented differences in the fractional herbage disappearance rate. There was an interaction between treatment and time in herbage depletion rate. The results of this study present a fuller picture of foraging dynamics during the first 4 h of grazing and its potential relationship with physiological markers of hunger as affected by grazing management.     

Efficient Object Detection and Classification Approach Using HTYOLOV4 and M²RFO-CNN

Object detection and classification are the trending research topics in the field of computer vision because of their applications like visual surveillance. However, the vision-based objects detection and classification methods still suffer from detecting smaller objects and dense objects in the complex dynamic environment with high accuracy and precision. The present paper proposes a novel enhanced method to detect and classify objects using Hyperbolic Tangent based You Only Look Once V4 with a Modified Manta-Ray Foraging Optimization-based Convolution Neural Network. Initially, in the pre-processing, the video data was converted into image sequences and Polynomial Adaptive Edge was applied to preserve the Algorithm method for image resizing and noise removal. The noiseless resized image sequences contrast was enhanced using Contrast Limited Adaptive Edge Preserving Algorithm. And, with the contrast-enhanced image sequences, the Hyperbolic Tangent based You Only Look Once V4 was trained for object detection. Additionally, to detect smaller objects with high accuracy, Grasp configuration was observed for every detected object. Finally, the Modified Manta-Ray Foraging Optimization-based Convolution Neural Network method was carried out for the detection and the classification of objects. Comparative experiments were conducted on various benchmark datasets and methods that showed improved accurate detection and classification results.     

Application of bacteria foraging algorithm for the design optimization of multi‐objective Yagi‐Uda array

The design of antenna array with desirable multiple performance parameters such as directivity, input impedance, beam width, and side‐lobe level using any optimization algorithm is a highly challenging task. Bacteria Foraging Algorithm (BFA), as reported by electrical engineers, is the most robust and efficient algorithm in comparison with other presently available algorithms for global optimization of multi‐objective, multi‐parameter design problems. The objective of this article is to apply this new optimization technique, BFA, in the design of Yagi‐Uda array for multi‐objective design parameters. We optimize length and spacing for 6 and 15 elements array to achieve higher directivity, pertinent input impedance, minimum 3‐dB beam width, and maximum front to back ratio both in the E and H planes of the array. At first, we develop a Method of Moments code in MATLAB environment for the Yagi‐Uda array structure for obtaining the above design parameters and then coupled with the BFA for the evaluation of the optimized design parameters. Detail simulation results are included to confirm the design criteria. © 2010 Wiley Periodicals, Inc. Int J RF and Microwave CAE , 2010.     

改进粒子群优化算法的移动机器人路径规划

针对单一智能优化算法求解机器人路径规划时易陷入局部误区的问题,提出改进粒子群优化算法(GB_PSO)用于机器人路径规划.该算法以粒子群优化算法(particle swarm optimization,PSO)为主体,由于遗传算法(genetic algorithm,GA)和细菌觅食算法(bacterial foraging optimization algorithm,BFO)更新策略所受环境影响的不同,拟合两种环境参数;然后计算粒子与不同环境参数之间的相关性将粒子群划分为两类,分别通过GA的选择、交叉、变异算子和BFO的趋化操作并行加强局部优化;最后通过改进的粒子群更新公式对粒子进行更新,实现机器人全局和局部路径的优化.实验结果表明,改进粒子群优化算法进行路径规划提高了局部和整体的搜索能力,路径规划速度快且路径距离短,同时具备更强的鲁棒性.     

惯性稳定平台单神经元/PID自适应复合控制与参数优化

针对成像载荷对惯性稳定平台高稳定精度控制的要求,提出一种基于改进型细菌觅食优化算法的单神经元/PID自适应复合控制方法。首先将单神经元与PID控制结合组成单神经元/PID自适应复合控制器,实现惯性稳定平台自适应控制,提高系统控制精度;其次,针对传统试凑法难以获得控制器最优控制参数的不足,采用改进型细菌觅食优化算法对复合控制器进行参数寻优,实现控制参数最优化;最后,对提出方法进行仿真分析和实验验证。实验结果表明:采用参数优化的单神经元/PID自适应复合控制后,稳定平台稳定精度和扰动抑制能力都得到明显提高,静基座和动基座条件下角位置误差分别为0.003 8°和0.290 4°,与传统PID控制相比分别提高19.1%和39.9%。     

基于细菌觅食算法的嵌入式机械臂角度控制器设计

进行机械臂角度控制器设计过程中,为提高机器人机械臂灵活性,降低关节角度控制误差,设计一种细菌觅食算法的嵌入式机械臂角度控制器。首先,构建机械臂动力学模型以获取机械臂的柔性特征及其关节位置,根据获取的信息确定角度控制器的硬件逻辑结构和算法。然后,使用ARM微处理器嵌入式操作系统,设计包含移动控制终端和机械臂控制端的控制器硬件结构。最后,采用细菌觅食算法优化控制器参数,并实现代码完成机器人机械臂角度的精准跟踪控制。仿真分析结果表明:所提方法具有较高的位姿跟踪精度、角度控制误差小、稳定性强,能够保证机械臂关节角度无超调,具有极高的机器工程应用价值。     

FORAGING IN CHEMICALLY DIVERSE ENVIRONMENTS: ENERGY,PROTEIN, AND ALTERNATIVE FOODS INFLUENCE INGESTION OF PLANT SECONDARY METABOLITES BY LAMBS

Interactions among nutrients and plant secondary metabolites (PSM) may influence how herbivores mix their diets and use food resources. We determined intake of a food containing a mix of terpenoids identified in sagebrush (Artemisia tridentata) when present in isoenergetic diets of increasing concentrations of protein (6, 9, 15, or 21% CP) or in isonitrogenous diets of increasing concentrations of energy (2.17, 2.55, 3.30, or 3.53 Mcal/kg). Lambs were offered choices between those diets with or without terpenes or between diets with terpenes and alfalfa hay. Intake of the diets with terpenes was lowest with the lowest concentrations of protein (6%) and energy (2.17 Mcal/kg) in the diets, and highest with diets of 15% CP and 3.53~Mcal/kg. In contrast, when terpenes were absent from the diets, lambs consumed similar amounts of all four diets with different concentrations of protein, and more of the diets with intermediate amounts of energy. When given a choice between the diet with or without terpenes, lambs preferred the diet without terpenes. When lambs were offered choices between terpene-containing diets and alfalfa, energy and protein concentrations influenced the amount of terpenes animals ingested. Energy densities higher than alfalfa, and protein concentrations higher than 6%, increased intake of the terpene-containing diet. Thus, the nutritional environment interacted with terpenes to influence preference such that lambs offered diets of higher energy or protein concentration ate more terpenes when forced, but not when offered alternative food without terpenes. The nutrients supplied by a plant and its neighbors likely influence how much PSM an animal can ingest, which in turn may affect the dynamics of plant communities, and the distribution of herbivores in a landscape. We discuss implications of these findings for traditional views of grazing refuges and varied diets in herbivores.     

Effects of predator chemical cues and behavioral biorhythms on foraging activity of terrestrial salamanders

Red-backed salamanders, Plethodon cinereus, show a variety of alarm responses to chemical cues from eastern garter snakes, Thamnophis sirtalis. We measured the foraging activity of red-backed salamanders exposed to water soiled by a garter snake (fed P. cinereus) or to unsoiled water. Salamanders exposed to snake-soiled water showed less foraging activity than salamanders exposed to unsoiled water; therefore, predators could have nonlethal effects on salamander populations. Our results also show additional factors influenced salamander foraging activity. Salamander foraging activity and responsiveness to chemical cues do not appear to have been affected by sex or food deprivation. Salamander foraging activity does appear to have been influenced by activity biorhythms. Foraging activity of animals in both treatments showed a bimodal periodicity that is consistent with natural activity patterns controlled by internal biorhythms. Exposure to snake-soiled water significantly reduced foraging activity during periods of peak foraging activity, but had a subtler effect0 on foraging activity during natural lulls in activity. We suggest that both activity biorhythms and exposure to chemical cues are important factors affecting salamander foraging behavior.