Dynamic flight stability of a bumblebee in forward flight

The longitudinal dynamic flight stability of a bumblebee in forward flight is studied. The method of computational fluid dynamics is used to compute the aerodynamic derivatives and the techniques of eigenvalue and eigenvector analysis are employed for solving the equations of motion. The primary findings are as the following. The forward flight of the bumblebee is not dynamically stable due to the existence of one （or two） unstable or approximately neutrally stable natural modes of motion. At hovering to medium flight speed [flight speed Ue = （0-3.5）m s^-1; advance ratio J = 0-0.44], the flight is weakly unstable or approximately neutrally stable; at high speed （Ue = 4.5 m s^-1; J = 0.57）, the flight becomes strongly unstable （initial disturbance double its value in only 3.5 wingbeats）.

Geographic Variation in Flower Size and Flower-Visitor Composition of Two Bumblebee-Pollinated, Spring-Flowering Herbs, <i>Lamium album</i>L. var. <i>barbatum</i>(Lamiaceae) and <i>Meehania urticifolia</i>(Lamiaceae)

Geographic variation of flower size is potentially affected by various biotic and abiotic factors such as pollinator size, abundance of nectar robbers, and temperature. To elucidate the effect of geographic variation of flower-visitor fauna on flower size, we investigated two spring-flowering, bumblebee-pollinated herbs, Lamium album L. var. barbatum (seven populations) and Meehania urticifolia (five populations), in central Japan. Flower-size variations were not correlated with altitude (an index of abiotic environmental change) in either species, but in both species they were related to the local species composition of flower visitors. In L. album, flowers were bigger in populations visited by long-tongued Bombus consobrinus and B. diversus queens, whereas they were smaller in populations visited by short-tongued bees such as Apis mellifera. Flower size did not vary much among populations of M. urticifolia visited by long-tongued bumblebees, but it was uniquely small in a population whose flowers were predominantly visited by the nectar-robbing bee Megachile japonica. In conclusion, both the size and nectar-robbing behavior of bees affect local flower-size adaptation in these two long-tubed, spring-flowering herbs.

A different gut microbial community between larvae and adults of a wild bumblebee nest （Bombus pascuorum）

Although the gut microbial communities in adult bumblebees and their as- sociated functionalities are widely studied, descriptive data on the larval gut microbiota are still limited. The gut microbiota of a fully sampled wild Bombus pascuorum nest has been characterized, using the multiplexed Illumina MiSeq 16S ribosomal RNA ampli- con sequencing technique. The nesters and foragers inhabiting the same nest showed the typical core bacterial sequences and only marginal differences in their characterized gut microbiota. The gut microbial communities within the adult and larval specimens differed strongly, as the typical core gut bacteria in the adult bumblebees are absent in the larval bumblebees. The bacterial communities within the larval gut are dominated by bacterial phylotypes of Enterobacteriaceae and Lactobacillaceae, supplemented with genera be- longing to Corynebacteriales and Bacillales. The function of this larval gut microbiota, being different from the adult, remains to be determined.

Diversity and functional analysis of Chinese bumblebee gut microbiota reveal the metabolic niche and antibiotic resistance variation of Gilliamella

Bumblebees play an important role in maintaining the balance of natural and agricultural ecosystems,and the characteristic gut microbiota of bumblebees exhibit significant mutualistic functions.China has the highest diversity of bumblebees;however,gut microbiota of Chinese bumblebees have mostly been investigated through cultureindependent studies.Here,we analyzed the gut communities of bumblebees from Sichuan,Yunnan,and Shaanxi provinces in China through 16S ribosomal RNA amplicon sequencing and bacterial isolation.It revealed that the bumblebees examined in this study harbored two gut enterotypes as previously reported:one is dominated by Gilliamella and Snodgrassella,and the other is distinguished by prevalent environmental species.The gut compositions obviously varied among different individual bees.We then isolated 325 bacterial strains and the comparative genomic analysis of Gillianiella strains revealed that galactose and pectin digestion pathways were conserved in strains from bumblebees,while genes for the utilization of arabinose,mannose,xylose,and rhamnose were mostly lost.Only two strains from the Chinese bumblebees possess the multidrug-resistant gene emrB,which is phylogenetically closely related to that from the symbionts of soil entomopathogenic nematode.In contrast,tetracycline-resistant genes were uniquely present in three strains from the USA.Our results illustrate the prevalence of strain-level variations in the metabolic potentials and the distributions of antibiotic-resistant genes in Chinese bumblebee gut bacteria.

Interspecific pollen transfer between two coflowering species was minimized by bumblebee fidelity and differential pollen placement on the bumblebee body

Aims When sympatric flowering plant species in a natural community share pollinators,study of plant-plant interactions via interspecific pollen transfer(iPT)is essential for understanding species coexistence.However,little is known about the extent of iPT between interactive species and its causes.Methods To explore how sympatric flowering plants sharing pollinators mini-mize deleterious effects of iPT,we investigated the pollination ecol-ogy of two endemic species,Salvia przewalskii and Delphinium yuanum,in an alpine meadow in the Hengduan mountains,southwest China.We quantified conspecific and interspecific visits by shared bumblebee pollinators,amounts of pollen placed on different body sites of the pollinators and stigmatic pollen loads on open-pollinated flowers.To examine whether iPT affects female fitness,we measured pollen germination and seed production in the two species in an artificial pollination experiment.Important Findingsone bumblebee species,Bombus trifasciatus,was found to be the sole effective pollinator for the two coflowering species.Pollination experiments indicated that deposition of heterospecific pollen could significantly decrease seed set in both species.Experiments showed that S.przewalskii pollen could germinate well on stigmas of D.yuanum,inhibiting conspecific pollen germination in D.yuanum.However,seed set was not lower under open pollination than under cross-pollination within species,suggesting that no female fitness loss was caused by iPT.in foraging bouts with pollinator switches,switches from S.przewalskii to D.yuanum were relatively more fre-quent(8.27%)than the converse(1.72%).However,iPT from S.prze-walskii to D.yuanum accounted for only 1.82%of total stigmatic pollen loads while the reverse iPT to S.przewalskii was 8.70%,indi-cating that more switches of bumblebees to D.yuanum did not result in higher iPT.by contrast,selection for reduced iPT to S.przewalskii would limit pollinator switches from D.yuanum.We found that a bumblebee generally carried pollen grains from both species but the two species differed in the position of pollen placement on the bum-blebee’s body;S.przewalskii’s pollen was concentrated on the dorsal thorax while D.yuanum’s pollen was concentrated ventrally on the head.This differential pollen placement along with pollinator fidelity largely reduced iPT between the two species with a shared pollinator.

Bumblebees with the socially transmitted microbiome:A novel model organism for gut microbiota research

Eusocial bumble and honey bees are important pollinators for global ecology and the agricultural economy.Although both the bumble and honey bees possess similar and host-restricted gut microbiota,they differ in aspects of morphology,autonomy,physiology,behavior,and life cycle.The social bee gut bacteria exhibit host specificity that is likely a result of long-term co-evolution.The unique life cycle of bumblebees is key for the acquisition and development of their gut microbiota,and affects the strain-level diversity of the core bacterial species.Studies on bumblebee gut bacteria show that they retain less functional capacity for carbohydrate metabolism compared with that of the honeybee.We discuss the potential roles of the bumblebee gut microbiota against pathogenic threats and the application of host-specific probiotics for bumblebees.Given the advantages of the bumblebee microbiome,including the simple structure and host specificity,and the ease of manipulating bumblebee colonies,we propose that bumblebees may provide a valuable system for understanding the general principles of host-microbe interactions,gut-brain axis,and vertical transmission.

Colony contact contributes to the diversity of gut bacteria in bumblebees （Bombus terrestris）

Social bees, like honeybees and bumblebees, have a close contact with nest mates of different developmental stages and generations. This could enhance bacterial transfer between nest mates and offers opportunities for direct transfer of symbionts from one generation to the next, resulting in a stable host specific gut microbiota. Gut sym- bionts of honeybees and bumblebees have been suggested to contribute in digestion and protection against parasites and pathogens. Here we studied the impact of contact with the bumblebee colony on the colonization potential of the bacterial families （i.e., Neisseri- aceae, Orbaceae, Lactobacillaceae and Bifidobacteriaceae） occurring in the gut of adult bumblebees （Bombus terrestris）. Bacterial profiles of the gut microbiota of B. terrestris were determined based on the hypervariable V4 region of the 16S rRNA using paired-end Illumina sequencing. In our experiments, we created different groups in which we grad- ually reduced the contact with nest mates and hive material. We made 3 observations： （i） reducing the contact between the colony and the bumblebee during adult life resulted in a significant drop in the relative abundance ofLactobacillus bombicola and Lactobacillus bombi; （ii） Bifidobacteriaceae required contact with nest mates to colonize the gut of B. terrestris and a significant lower bacterial diversity was observed in bumblebees that were completely excluded from colony contact during the adult life; （iii） Snodgrassella and Gilliamella were able to colonize the gut of the adult bumblebee without any direct contact with nest mates in the adult life stage. These results indicate the impact of the colony life on the diversity of the characteristic bumblebee gut bacteria.

Sensitivities of three bumblebee species to four pesticides applied commonly in greenhouses in China

This study was conducted to evaluate the effects of four pesticides （Mosplian, Kingbo, Score and Lvrtong） applied commonly in greenhouses in China, on three bumblebee species （Bombus hypocrita, Bombus ignitus and Bombuspatagiatus）. The study used a contact experiment and oral toxicity LD50 values. The results showed that the mortality for B. hypocrita after contacting the four pesticides was significantly lower than B. patagiatus and B. ignitus, but there was no significant difference between B. patagiatus and B. ignitus. The oral toxicity median lethal dose （LD50） value of Mosplian to B. hypocrita （0.0028/zg active ingredient/bee） was significantly higher than that to B. ignitus （0.0023μg active ingredient/bee） and B. patagiatus （0.0021μg active ingredient/bee）. Of the bee species, it can be concluded that B. hypocrita was the least susceptible to the four pesticides. The mortality rates of each bumblebee species after contact with Mosplian were significantly higher than for the other three pesticides and the control group. For Kingbo, the rates were significantly higher than the control group, but Score and Lvrtong exposed groups showed no significant increase in mortality relative to the control group. It can therefore be concluded that the pesticides differ in their negative influences on bumblebees, and that Mosplian is the most harmful.

A Three-axis PD Control Model for Bumblebee Hovering Stabilization

Flight stabilization in insects is normally achieved through a closed-loop system integrating the intemal dynamics and feedback control. Recent studies have reported that flight instability may exist in most flying insects but how insects achieve the flight stabilization still remains poorly understood. Here we propose a control model specified for bumblebee hovering stabilization by applying a three-axis PD （proportional-derivative）-controller to a free-flying bumblebee computational model with six Degrees of Freedom （DoFs）. Morphological and kinematic models of a realistic bumblebee in hovering are built up based on measurements whereas a versatile bio-inspired dynamic flight simulator is employed in simulations. A simplified flight dynamic model is further developed as a fast model for control parameter tuning. Our results demonstrate that the stabilizing control model is capable of achieving the hovering stabilization with small perturbations in terms of 6-DoF, implying that the simplified linear algorithms can still work reasonably for bumblebee hovering. A further sensitivity analysis of the control parameters reveals that yaw control via manipulating pitch angle of the wing is mostly sensitive, implicating that bumblebee may utilize alternative yaw control strategies.

High dimensional AdS-like black hole and phase transition in Einstein-bumblebee gravity

In this study,we obtained an exact high dimensional anti-de Sitter(AdS)black hole solution in Einsteinbumblebee gravity theory.This AdS-like black hole can only exist with a linear functional potential of the bumblebee field.We found that the Smarr formula and the first law of black hole thermodynamics can still be constructed in this Lorentz symmetry breaking black hole spacetime,but the conceptions of the black hole horizon area/entropy and the volume inside the horizon should be renewed due to its anisotropy.We also found that two types of phase transition exist:small-large black hole phase transition and Hawking-Page phase transition,like those of the Schwarzschild AdS black hole.After Lorentz symmetry breaking,the black hole mass at the divergent point of heat capacity becomes small,and the Gibbs free energy of the meta-stable large black hole is also smaller,showing that the large stable black hole can be more easily formed.

Chemical reproductive traits of diploid Bombus terrestris males： Consequences on bumblebee conservation

The current bumblebee decline leads to inbreeding in populations that fosters a loss of allelic diversity and diploid male production. As diploid males are viable and their offspring are sterile, bumblebee populations can quickly fall in a vortex of extinction. In this article, we investigate for the first time a potential premating mechanism through a major chemical reproductive trait （male cephalic labial gland secretions） that could prevent monandrous virgin queens from mating with diploid males. We focus our study on the cephalic labial gland secretions of diploid and haploid males ofBombus terrestris （L.）. Contrary to initial expectations, our results do not show any significant differentiation of cephalic labial gland secretions between diploid and haploid specimens. Queens seem therefore to be unable to avoid mating with diploid males based on their compositions of cephalic labial gland secretions. This suggests that the vortex of extinction of diploid males could not be stopped through premating avoidance based on the cephalic labial gland secretions but other mechanisms could avoid mating between diploid males and queens.

Slowly rotating Einstein-bumblebee black hole solution and its greybody factor in a Lorentz violation model

We obtain an exact slowly rotating Einstein-bumblebee black hole solution by solving the corresponding rr and tθ components of the gravitational field equations for both cases:A)b u=(0,b(r),0,0) and B) bu=(0,b(r),b(θ),0) .Then,we check the other gravitational field equations and the bumblebee field motion equations using this solution.We find that for case A,there indeed exists a slowly rotating black hole solution for an arbitrary LV(Lorentz violation)coupling constant l;however,for case B,this slowly rotating solution exists if and only if coupling constant l is as small as or smaller than angular momentum a.Thus far,no full rotating black hole solution has been published;hence,the Newman-Janis algorithm cannot be used to generate a rotating solution in the Einstein-bumblebee theory.This is similar to the Einstein-aether theory,wherein only some slowly rotating black hole solutions exist.To study the effects of this broken Lorentz symmetry,we consider the black hole greybody factor and find that,for angular index l=0 ,LV constant l decreases the effective potential and enhances the absorption probability,which is similar to the results for the non-minimal derivative coupling theory.

The cephalic labial gland secretions of two socially parasitic bumblebees Bombus hyperboreus （Alpinobombus） and Bombus inexspectatus （ Thoracobombus） question their inquiline strategy

Social parasitic Hymenopterans have evolved morphological, chemical, and behavioral adaptations to overcome the sophisticated recognition and defense systems of their social host to invade host nests and exploit their worker force. In bumblebees, so- cial parasitism appeared in at least 3 subgenera independently： in the subgenus Psithyrus consisting entirely of parasitic species, in the subgenus Alpinobombus with Bombus hy- perboreus, and in the subgenus Thoracobombus with B. inexspectatus. Cuckoo bumblebee males utilize species-specific cephalic labial gland secretions for mating purposes that can impact their inquiline strategy. We performed cephalic labial gland secretions in B. hyperboreus, B. inexspectatus and their hosts. Males of both parasitic species exhibited high species specific levels of cephalic gland secretions, including different main com- pounds. Our results showed no chemical mimicry in the cephalic gland secretions between inquilines and their host and we did not identify the repellent compounds already known in other cuckoo bumblebees.

Bumblebee

剧情简介:拥有一位战斗力爆表、又萌又暖的汽车人朋友会是一种怎样独特的体验呢?18岁的少女Charlie(查莉)和汽车人Bumblebee(大黄蜂)——B-127之间上演了一个温暖诙谐又惊险刺激的故事。

基于模板识别的高精度自动定位系统

为满足机器人辅助医疗手术中高精度自动识别物体的需要,利用Bumblebee 2摄像头拍摄图像,把黑白交互的椭圆和圆作为一个模板,用改进的角点提取方法提取出图像中的角点;在对图像进行增强之后,利用模板黑白格的几何对称性特征提取模板中的角点,然后区分出椭圆中的角点和圆中的角点,最后利用向量垂直关系提取出椭圆中的目标角点,识别出模板.通过Bumblebee 2自带的深度函数,提取模板的深度,得到模板在摄像头空间中的坐标,达到高精度自动定位物体的目的,克服传统摄像机需要标定内外参数的步骤.实验表明,定位误差在0.42 mm之内,基本上可以满足手术的要求.

Conservation genomics analysis reveals recent population decline and possible causes in bumblebee Bombus opulentus

Bumblebees are a genus of pollinators(Bombus)that play important roles in natural ecosystem and agricultural production.Several bumblebee species have been recorded as under population decline,and the proportion of species experiencing popula-tion decline within subgenus Thoracobombus is higher than average.Bombus opulentus is 1 species in Thoracobombus,but little is known about its recent population dynamics.Here,we employed conservation genomics methods to investigate the population dynam-ics of B.opulentus during the recent past and identify the likely environmental factors that may cause population decline.Firstly,we placed the scaffold-level of B.opulentus ref-erence genome sequence onto chromosome-level using Hi-C technique.Then,based on this reference genome and whole-genome resequencing data for 51 B.opulentus samples,we reconstructed the population structure and effective population size(Ne)trajectories of B.opulentus and identified genes that were under positive selection.Our results revealed that the collected B.opulentus samples could be divided into 2 populations,and 1 of them experienced a recent population decline;the declining population also exhibited lower ge-netic diversity and higher inbreeding levels.Genes related to high-temperature tolerance,immune response,and detoxication showed signals of positive selection in the declining population,suggesting that climate warming and pathogen/pesticide exposures may con-tribute to the decline of this B.opulentus population.Taken together,our study provided insights into the demography of B.opulentus populations and highlighted that popula-tions of the same bumblebee species could have contrasting Ne trajectories and population decline could be caused by a combination of various stressors.

人工智能在工程采购招投标系统中的应用分析

"互联网+"时代下,新一代信息技术的普及和大数据应用的推广能够促进交易性电子招投标系统的构建,解决传统招投标服务中存在的信息不对称、以人为核心的决策机制存在的主观决策风险等问题。因此,明晰交易性电子招投标系统的建设要点,并对已有研发系统进行探索分析,有助于完善交易性电子招投标系统的各项应用功能。采筑联合华侨城和哈尔滨工业大学研发的招标机器人BumbleBee及其在商业锅炉联合采购中成功应用,能够助推交易性电子招投标系统的智慧化发展。

RISC-V MCU的FreeRTOS移植与应用开发

具有相同的RISC-V指令集的处理器实现并不相同。本文将针对基于RISC-V开源指令集的处理器芯片GD32VF103 MCU,介绍FreeRTOS在IAR EWRISC-V编译和开发环境下的移植过程。采用RTOS后,嵌入式系统很难监控系统的运行时行为、发现应用存在的问题,本文基于Tracealyzer分析工具直观地跟踪系统行为,分析系统中可能的错误,提高代码的鲁棒性。

A “Living” Machine

Biomimetics (or bionics) is the engineering discipline that constructs artificial systems using biological principles. The ideal final result in biomimetics is to create a living machine. But what are the desirable and non-desirable properties of biomimetic product? Where can natural prototypes be found? How can technical solutions be transferred from nature to technology? Can we use living nature like LEGO bricks for construction our machines? How can biology help us? What is a living machine? In biomimetic practice only some “part” (organ, part of organ, tissue) of the observed whole organism is utilized. A possible template for future super-organism extension for biomimetic methods might be drawn from experiments in holistic ecological agriculture (ecological design, permaculture, ecological engineering, etc.). The necessary translation of these rules to practical action can be achieved with the Russian Theory of Inventive Problem Solving (TRIZ), specifically adjusted to biology. Thus, permaculture, reinforced by a TRIZ conceptual framework, might provide the basis for Super-Organismic Bionics, which is hypothesized as necessary for effective ecological engineering. This hypothesis is supported by a case study-the design of a sustainable artificial nature reserve for wild pollinators as a living machine.

Elevational Floral Size Variation in <i>Prunella vulgaris</i>

Floral size is potentially influenced by local pollinators’ body size. As pollinator fauna and size often change with elevation, correlation between elevational variation of pollinator size and floral size is expected. We investigated the variation of floral size in Prunella vulgaris L. (Laminaceae) and the variation of their pollinator fauna along an elevational gradient. We measured the floral size of four traits: corolla length (CL), corolla tube length (CTL), corolla width (CW), and calyx length (CAL), in 23 populations, and found that CL and CTL were negatively correlated with elevation, and CW and CAL were not. Six bumblebee species visited the flower, and the visiting bee fauna differed among populations;the smallest and the largest bumblebee species visited the high elevational range (above 1800 m a. s. l.) populations, and the largest and the second largest bumblebee species visited the middle elevational range (1400 - 1800 m a. s. l.). Although abiotic factors can potentially affect floral size, the fact that we do not find an elevational decrease in CW and CAL suggests that the elevational change in P. vulgaris’s CL and CTL reflects the local pollinator size.