臭蜣螂体壁表面结构及其与减粘脱附功能的关系

采用扫描电镜技术观察并描述了臭蜣螂Copris ochus头部、胸腹部和足部体表上的凹陷和刚毛的结构。发现有4种简单的凹陷,其三维结构、边缘类型和位于凹陷中央的带孔刚毛的长度在身体不同部位均有不同。体壁上还有中央具隆起的凹陷,其中心具带孔刚毛;或缺中心刚毛但在其半环状外边沿上具一小刚毛的凹陷。简单凹陷广泛分布于除腹部以外的各部分,但具中央隆起的凹陷仅出现在前胸背板,具半环状外边沿的凹陷出现在腿节上。在鞘翅纵沟纹的念珠状结中有管状开口。体壁上还有大小和形状不同的刚毛,它们不同于生于凹陷的刚毛。凹陷和刚毛的分布及形态构成体表的非光滑表面,作者探讨了这些结构与体表减粘脱附功能的关系。     

几种刚毛的结构及其仿生学

动物体表的刚毛形态各异,功能多样,不仅参与感觉器官的构成,还是重要的运动器官。刚毛在运动中的功能因结构不同而异。丈章主要介绍了蟑螂（Periplaneta americana）尾须的结构和仿生应用、强疏水性刚毛使得水黾（Gerris remigis）和捕鱼蛛（Dolomedes trition）在水面行走的机制、跳蛛（Evarcha arcuata）和壁虎（Gecko japoricus,Gekko gecko）脚底刚毛的粘附机制和仿生学研究,以及蜣螂（Copris ochus,Motschulsky）刚毛的减黏脱附功能及其仿生学应用。     

pH对紫膜表面电位的影响

用荧光标记物1,8-AMS与紫膜结合,测量了能化态和非能化态下紫膜表面电位随介质pH的变化.在pH5.5以下,紫膜表面电位随pH的降低而下降,但囊泡中的紫膜表面电位变化幅度较大;在pH5.5以上,处于非能化态的紫膜(无论是紫膜碎片还是处于囊泡中)的表面电位都没有明显变化,处于能化态时,紫膜碎片的表面电位在pH9.2出现一个峰.     

人体躯干模型中肺的存在对体表电位分布的影响

在所建三维人体躯干模型的基础上,给出了如何应用边界元方法对非均匀人体场域进行求解。在设定心外膜电位分别呈现为单偶极子和双偶极子时,求出相应非均匀场域中的体表电位分布,并将它们与相同情况下均匀场域的体表电位分布进行分析比较。结果表明：躯干模型中肺的存在虽然对体表电位中极值的大小和位置没有太大影响,但却较大程序地改变了整个体表电位的分布状况,具体地说,就是由于肺的存在使得体表电位值较均匀时的相对误差高     

基于小波变换的心肌梗塞体表电位特征分析

小波变换已被很多心电学者用于ＥＣＧ信号的特征分析检测,在虚拟心脏基础上,选取合适的小波,对心肌梗塞的仿真体表电位进行小波变换细节分量处理,提出了一种新的体表电位形态特征的分析方法。结果表明,基于小波变换处理后体表电位图可以更地提示不同部位心肌在体表电位分布的特征,其表征出的拓扑形态对体表电位和虚拟心脏方法用于心肌梗塞临床诊断提供了一种新的途径。     

臭蜣螂体壁的组织结构

对臭蜣螂Copris ochus Motschulsky体壁的组织学结构进行了光镜观察。用伊红和马洛赖氏三色法染色可见体壁尤其在腹壁的折叠处及膜翅壁中存在着胶原纤维。鞘翅中有内腔,具皮细胞,鞘翅背部表皮下陷形成桥墩状结构以支撑加固鞘翅腔并减轻重量。膜翅的背腹壁之间也具有内腔和皮细胞,并充满油脂腺（经分析是棕脂肪细胞腺）及其分泌物。足的肌肉束中被大量棕脂肪细胞腺环绕。棕脂肪细胞的存在为周围器官提供所需能量,并有减轻重量和润滑的作用。体壁表面具有大量突起、刚毛及大量粗细不等的管道与其下相通,加上大量油脂腺及其分泌机能,为其体表的减粘特性提供了形态和化学基础。鞘翅内腔的结构可为建筑仿生学提供一定参考。     

红螺菌吸附铜的动力学与脱附研究

研究了红螺菌(Rhodospirillum)对Cu~(2 )的吸附动力学行为,在一定的条件下,吸附在45 min达到平衡,吸附平衡时最大吸附量为48.23 mg·g~(-1)。应用准一级和准二级反应动力学模型进行数据分析,结果表明菌体对Cu~(2 )的吸附符合准二级动力学模型。比较分析了多种脱附剂对菌体脱附,EDTA和柠檬酸是较有效的洗脱剂,脱附率分别为86.4％、66.9％;无机酸及无机盐对菌体的脱附效果很差,脱附率在20％左右。X-射线衍射分析表明,菌体吸附Cu~(2 )后没有形成新晶相,并且菌体部分晶相转变为非晶相。     

新型温敏微载体用于无损收获贴附型细胞的研究

聚N-异丙基丙烯酰胺(PNIPAAm)接枝的微载体由于表面同时含有疏水性的异丙基和亲水性的酰胺基而成为一种典型的温敏性微载体。但是微载体表面PNIPAAm接枝浓度会很大地影响贴附型细胞在微载体上的贴附能力和脱附能力,限制了它在相关领域的应用效果。该实验运用原子转移自由基聚合作用(atom transfer radical polymerization,ATRP)合成法将PNIPAAm接枝到表面氯甲基化的聚苯乙烯微球[chloromethylated poly(styrene),CMPS]表面,合成不同PNIPAAm接枝浓度的温敏微载体,研究其细胞贴附、脱附以及在转瓶悬浮培养中的细胞增殖能力。同时,运用电子扫描电镜(scanning electron microscope,SEM)、原子力显微镜(atomic force microscope,AFM)、X-射线光电子能谱(X-ray photoelectron spectroscopy,XPS)对温敏微球表面形貌进行表征。实验结果表明,当PNIPAAm添加浓度是200 mmol/L时,温敏微球表现出60%的细胞脱附率及50%的细胞贴附率,并且在转瓶悬浮培养中具有持续稳定的增殖能力。另外,SEM与AFM表征结果显示,温敏微载体表面粗糙度有明显地增加;XPS结果表明,温敏微球表面N元素有显著增加。这些结果证明了微载体上温敏材料NIPAAm的成功接枝。以上实验结果表明,这种新型温敏微载体具有良好的细胞贴附和脱附能力,将会是大规模培养贴附型细胞的良好材料。     

怀头鲇胚胎发育过程卵膜形态结构变化及对孵化影响

采用扫描电镜和光学解剖镜,对黑龙江水域怀头鲇(Silirus soldatovi)成熟卵膜层次构造和受精卵胚胎发育过程中卵膜形态结构变化进行观察,并比较未脱黏和人工脱黏卵受精卵膜的表面超微结构变化.结果显示,受精卵膜的胶膜表面由一层薄而致密的物质组成,上有微孔构造.未脱黏受精卵膜表面胶膜光滑致密,多孔隙,内有小梁相连,随胚胎发育逐渐膨胀、展开、变薄,破膜期自然脱落.人工脱黏几乎全部脱去鱼卵的胶膜层,从而使卵失去黏性.脱去胶膜层的受精卵膜表面由不规则的颗粒状结构紧密嵌合而成,表面粗糙,胚胎发育过程中颗粒形状变化不大,但颗粒层逐渐变薄而且疏松,直至胚胎破膜而出:胚胎发育后期颗粒层有过早脱落和破洞出现.同时对活体鱼卵进行连续比较观察,讨论了卵膜结构及动态变化与孵化效果的关系.     

溶菌酶与α-MnO2间的界面吸附作用

研究了溶菌酶（LSZ）与α-MnO2的界面吸附作用及其影响因素。结果表明,体系pH值是影响LSZ在α-MnO2表面吸附、脱附的重要因素。在pH3.8～10.8范围内,LSZ的吸附率随着体系pH值的升高而大致呈上升趋势。在较低pH值范围内（pH〈7.1）,LSZ的脱附率随pH的升高增幅较大;在较高pH值范围内（pH〉7.1）,LSZ的脱附率则随pH的升高而略微下降。但是,LSZ自α-MnO2表面的脱附率在各pH值下均处于较低水平,吸附反应具有较高的不可逆性。LSZ在α-MnO2表面的吸附率随离子强度的增大而增大,然而Na^＋、Ca^2＋和Mg^2＋3种离子对LSZ吸附率的影响没有差别。LSZ的等温吸附曲线符合Langmuir吸附方程式,形状呈L型。FTIR进一步证明,α-MnO2表面的确有LSZ分子吸附;吸附态LSZ分子的空间构象发生了改变。     

Dung beetle activity affects rain forest seed bank dynamics and seedling establishment

Dung beetles relocate vertebrate feces under the soil surface, and this behavior has many ecological consequences. In tropical forests, for example, seeds defecated by mammals that are subsequently buried by dung beetles are less likely to suffer predation. While the effects of dung beetles on the fate of defecated seeds have been relatively well studied, their effect on seeds already buried in the soil has not. To contribute to fill this gap, we designed a study with three objectives: (a) Describe the vertical re‐distribution of soil seeds that occurs due to dung beetle activity; (b) Determine if beetle activity favors establishment of seedlings from the soil seed bank; and (c) Determine if the effect of dung beetles is stronger in sites of recurrent mammal defecation. We carried out three complementary field experiments, one with artificial seeds (plastic beads) of three sizes buried at known depths, one with two species of seeds buried at those same depths, and one with the natural soil seed bank in sites of single vs. recurrent defecation. Buried beads were moved by dung beetles along the vertical axis, both upwards (9.5%) and downwards (11.5%); smaller beads were more frequently moved downwards while the contrary occurred for larger beads. Dung beetle activity caused an increase in seedling establishment, both from experimentally buried seeds and from the natural seed bank. Defecation recurrence had no effect on seedling establishment. We conclude that dung beetle activity affects seed bank dynamics with important consequences for seedling establishment in tropical forests.Abstract in Spanish is available with online material.     

Linking Biodiversity,the Environment and Ecosystem Functioning: Ecological Functions of Dung Beetles Along a Tropical Elevational Gradient

Biodiversity loss and anthropogenic environmental changes are known to impact ecosystem functions and services. However, there are still some uncertainties such as confounding environmental factors other than community attributes that affect ecosystem functioning. Our goal was to understand what factors influence the performance of Scarabaeinae dung beetle functions, testing the hypothesis that both community attributes and environmental variables influence the performance. Toward this aim, we collected dung beetles along an elevational gradient (800–1400 m a.s.l.) in the Espinhaço mountain range (Brazil) and quantified dung beetle functions, that is, dung removal, soil excavation and secondary seed dispersal. We recorded data on environmental factors related to climate, soil and vegetation and evaluated their effects on dung beetle functions. Dung beetle ecological functions declined with elevation and the decrease was more pronounced than richness, indicating that there are other factors involved in functions performance besides diversity of beetles. Indeed, we found that the ecological functions measured were dependent on both dung beetle community attributes and environmental factors. Climate, soil and vegetation influenced dung beetle function performance as much as richness, abundance and body size. Dung beetle functional diversity did not explain any of the functions measured. Our study demonstrates that ecological functions are directly influenced by both community attributes and environmental variables and confirms the link between biodiversity, environment and ecosystem functioning.     

半干旱草原大中型土壤动物在畜粪分解中的作用

土壤动物是陆地生态系统的重要组分, 在有机质分解过程中具有重要作用。目前有关土壤动物在生态系统分解中的作用研究主要聚焦于植物凋落物的分解, 而对动物粪便分解的研究稀少。本研究在内蒙古典型草原设置了马粪和牛粪分解原位实验, 使用不同孔径的金属隔离网排除不同体型大小的土壤动物, 通过测定大中型土壤动物对畜粪分解过程中质量损失、碳氮含量和微生物呼吸以及土壤养分动态变化的影响, 解析其在分解中的作用。设置5个处理, 即CK, 仅土壤, 无粪; T0, 粪添加+0.425 mm隔离网(排除了粪居型和掘洞型粪金龟和中型土壤动物); T1, 粪添加+1 mm隔离网(排除了粪居型和掘洞型粪金龟); T2, 粪添加+2 mm隔离网(排除了掘洞型粪金龟); T3, 仅粪添加(不排除土壤动物)。结果表明: (1)在畜粪分解60天内, 土壤动物对畜粪的干质量损失没有显著的促进作用(P > 0.05); 相反, 在畜粪分解360天, 不隔离土壤动物处理(T3)显著地提高了牛粪干质量损失(P < 0.05), 而降低了马粪干质量损失(P < 0.05)。(2)在畜粪分解的60天内, 畜粪中碳和氮含量下降速度在有土壤动物存在的情况下(T3)快于隔离土壤动物(T0和T1)。(3)两种畜粪添加增加了土壤微生物的呼吸, 且这种增加趋势在实验的第15天和第30天在土壤动物存在时(T3)最明显。(4)与对照(CK)相比, 马粪添加处理提高了土壤速效氮、有机碳的含量和土壤含水量, 且这种增加趋势在排除掘洞型粪金龟(T2)和不排除土壤动物(T3)条件下表现更显著(P < 0.05), 而牛粪添加处理没有明显改变这些指标(P > 0.05)。研究表明, 分解初期粪金龟的取食和活动会改变畜粪的理化性质, 进而影响分解后期土壤生物在畜粪分解中的作用。     

蜣螂与壁虎刚毛的比较及改形对其功能的影响

脱附与粘附是工程作业的两个相互矛盾的难题,土壤和物料的粘附严重降低了机械的作业效率和质量,没有粘附又使某些机械无法工作或运行。目前世界流行的脱附技术,包括向界面注入空气的充气法、向界面注入溶液的充液法、利用机械或超声波的振动法、施加电场的电渗法、施加磁场的磁     

Restudies on Body Surface of Dung Beetle and Application of Its Bionics Flexible Technique

1　IntroductionTheadherencebetweenthesoilandthetouchingmachinecomponentscriticallyreducestheworkingeffi ciencyandqualityofthediggingmachinesandfarmtools.Therefore ,thenon adherenceisabigproblemintheindustry ,agriculturalproduction ,andmechanicalengineering[1- 4] .Thesurveyshaveshownthatthecar riagevolumeofdumptrucksworkinginstickyclaycanbereducedby 2 0 %to 5 0 %duetoadheredsoil[3] .Thus,itisanurgentdemandtodevelopaneffectivetechniqueforthereductionofadhesionanddraft.Thebodysurfacesoftheanimal…     

Use of habitat resources by scarab dung beetles in an savanna

In the Queen Elizabeth National Park, Uganda, we compared the scarab beetle assemblages in the dung of three wild ungulates (African buffalo, a ruminant foregut fermenter; hippopotamus, nonruminant foregut fermenter; and warthog, nonruminant hindgut fermenter). Dung was collected from two sandy-clay soils with different percentage of coarse sand. We aimed at investigating habitat resource selection by dung beetle species within a savanna natural contest with abundant and diverse food availability. Analyses were performed to detect differences for dung beetle assemblages in abundance, diversity, functional groups. Species richness in the three dung types and in the two soil types was similar. However, warthog dung and sandy-rich soil appeared the preferred habitat resources, in terms of abundance and biomass, while hippopotamus dung hosted the lowest values for these parameters. The analysis of functional groups revealed that slow-burying tunnellers held the major role, both in terms of abundance and biomass, and were mainly found in warthog dung.     

The effects of land use change on native dung beetle diversity and function in Australia's Wet Tropics

The impacts of land use change on biodiversity and ecosystem functions are variable, particularly in fragmented tropical rainforest systems with high diversity. Dung beetles (Scarabaeinae) are an ideal group to investigate the relationship between land use change, diversity and ecosystem function as they are easily surveyed, sensitive to habitat modification and perform many ecosystem functions. Although this relationship has been investigated for dung beetles in some tropical regions, there has been no study assessing how native dung beetles in Australia's tropical rainforests respond to deforestation, and what the corresponding consequences are for dung removal (a key ecosystem function fulfilled by dung beetles). In this study we investigated the relationship between dung beetle community attributes (determined through trapping) and function (using dung removal experiments that allowed different dung beetle functional groups to access the dung) in rainforest and cleared pasture in a tropical landscape in Australia's Wet Tropics. Species richness, abundance and biomass were higher in rainforest compared to adjacent pasture, and species composition between these land use types differed significantly. However, average body size and evenness in body size were higher in pasture than in rainforest. Dung removal was higher in rainforest than in pasture when both functional groups or tunnelers only could access the dung. Increased dung removal in the rainforest was explained by higher biodiversity and dominance of a small number of species with distinct body sizes, as dung removal was best predicted by the evenness in body size of the community. Our findings suggest that functional traits (including body size and dung relocation behaviour) present in a dung beetle community are key drivers of dung removal. Overall, our results show that deforestation has reduced native dung beetle diversity in Australian tropical landscapes, which negatively impacts on the capacity for dung removal by dung beetles in this region.     

Newly released non‐native dung beetle species provide enhanced ecosystem services in New Zealand pastures

1. Whether the release of non‐native insect species benefits or harms ecosystem services has been the subject of debate. In New Zealand, the release of new non‐native dung beetle species was intended to enhance ecosystem services but concerns were raised over possible negative effects. 2. Field cage trials used three newly released dung beetle species to investigate two concerns: that soil disturbance from dung beetle activity increases soil losses in runoff after rainfall; and that dung burial increases survival of infective parasitic nematodes on pasture. 3. Three treatments – dung + beetles, dung‐only, and controls (without dung or beetles) – were applied on each of three soil types with different permeability: sandy loam, clay loam, and compacted clay. 4. Dung beetle activity resulted in significant reductions of 49% and 81% in mean surface runoff volume, depending on simulated rainfall intensity. Amounts of sediment in the runoff did not change under an extreme rainfall simulation, but in a less extreme rainfall simulation the presence of dung beetles resulted in a 97% reduction in mean sediment amount in runoff. 5. The numbers of infective third‐stage nematode larvae recovered from foliage varied considerably between soil types and through time; however, dung beetle activity reduced overall mean nematode numbers on grass around the dung pats by 71%. 6. This study adds to global evidence that dung beetles can improve agricultural ecosystem services by providing data on services that have rarely been investigated: reduced runoff/soil losses through increased soil porosity, and reductions in parasitic nematodes.     

Monkey and dung beetle activities influence soil seed bank structure

In Neotropical forests, dung beetles act as efficient secondary dispersers of seeds that are dispersed primarily by red howler monkeys. Here, we investigated the origins of soil seed bank variability in relation to monkey and dung beetle activity, to assess the impact of dung beetles on seed fate, and their adaptability to resource availability. This question is important to better understand the process of tree regeneration, and is especially timely in the current context of threat to primates. We characterized soil seed bank structures in sites differing in monkey frequentation, and conducted field experiments with artificial beads to monitor bead fate. We also conducted experiments on specific roller and tunneller beetle species to examine bead processing behavior and its variability among and within species. We found that seed number and diversity increased with monkey frequentation, but seed viability was optimal under moderate monkey frequentation. We showed for the first time that dung provisioning yielded higher beetle activity in sites more often visited by monkeys, which calls for further investigation to understand the mechanisms of attraction to resource and potential spatial structuration of beetle populations. Although all beetle species involved in the experiments actively excluded beads from dung reserves, selectivity was higher for small than large beetle species, and for large compared to small bead sizes. It also increased when per-capita dung resource decreased, suggesting that intraspecific competition could alter seed fate. Altogether, our results support a major role of dung beetles in soil seed bank structure and dynamics. They reveal interesting interspecific variability within the dung beetle community and a complex interplay with primary dispersal.