Environmental change and the phenology of European aphids

Aphids, because of their short generation time and low developmental threshold temperatures, are an insect group expected to respond particularly strongly to environmental changes. Forty years of standardized, daily data on the abundance of flying aphids have been brought together from countries throughout Europe, through the EU Thematic Network 'EXAMINE'. Relationships between phenology, represented by date of first appearance in a year in a suction trap, of 29 aphid species and environmental data have been quantified using the residual maximum likelihood (REML) methodology. These relationships have been used with climate change scenario data to suggest plausible changes in aphid phenology. In general, the date of first record of aphid species in suction traps is expected to advance, the rate of advance varying with location and species, but averaging 8 days over the next 50 years. Strong relationships between aphid phenology and environmental variables have been found for many species, but they are notably weaker in species living all year on trees. Canonical variate analysis and principal coordinate analysis were used to determine ordinations of the 29 species on the basis of the presence/absence of explanatory variables in the REML models. There was strong discrimination between species with different life cycle strategies and between species feeding on herbs and trees, suggesting the possible value of trait-based groupings in predicting responses to environmental changes.     

硫酸镁微量气泵吸入治疗毛细支气管炎患儿的疗效及对肺功能的影响

目的:探讨硫酸镁微量气泵吸入治疗毛细支气管炎患儿的疗效及对肺功能的影响。方法:选择2012年1月-2014年8月我院收治的毛细支气管炎患儿120例,随机分为研究组和对照组各60例。两组均给予吸氧、吸痰、镇静、止咳、抗感染和支气管扩张剂治疗,研究组再加用25%硫酸镁溶液0.1~0.2ml/(kg.次)气泵吸入治疗,比较两组临床疗效及患儿肺功能变化。结果:研究组总有效率为98.3%,显著高于对照组的88.3%(P0.05);研究组患儿咳嗽、气促、喘息、肺部哮鸣音/啰音消失时间及住院时间显著短于对照组(P0.05);治疗后两组患儿潮气量(VT)、达峰时间比(t PTEF/t E)和v PTEF/v E均明显升高,吸呼比(Ti/Te)明显降低(P0.05),研究组VT、t PTEF/t E和v PTEF/v E显著高于对照组,Ti/Te显著低于对照组(P0.05)。结论:硫酸镁微量气泵吸入治疗小儿毛细支气管炎可以改善患儿喘憋、气促、呼吸困难等症状以及肺功能,临床效果较好。     

Randomized study comparing endoscopic ultrasound-guided Trucut biopsy and fine needle aspiration with high suction

H. Gerke, M. K. Rizk, A. D. Vanderheyden and C. S. Jensen
Randomized study comparing endoscopic ultrasound-guided Trucut biopsy and fine needle aspiration with high suction
Objectives:  Endoscopic ultrasound (EUS)-guided Trucut biopsy (TCB) enables acquisition of tissue cores for histological assessment. Because of the rigid needle and the spring mechanism, tissue acquisition can be difficult from regions that require sharp angulation of the echoendoscope. Fine needle aspiration with high suction (FNAHS) has been proposed as a method to obtain histological tissue cores while affording the flexibility to obtain specimens even with extreme endoscope angulation. The objective was to compare prospectively these two methods in their ability to obtain specimens for histological assessment and in their diagnostic accuracy, including cytological diagnosis when achieved.
Methods:  Eighty lesions in 77 patients were amenable to transoesophageal, transgastric or transrectal biopsy and were randomized to TCB ( n  = 44) or FNAHS ( n  = 36). Each specimen was assessed for adequacy (scoring system where a score of 0 was no material, 1–2 was considered cytological, and 3–5 was considered histological). Follow-up information was obtained to establish a gold standard final diagnosis.
Results:  The median histological scores for FNAHS and TCB were 2 and 5, respectively. Histological cores were obtained in 95.3% of TCB, as opposed to 27.8% in the FNAHS group ( P  < 0.0001). Although the diagnostic accuracy for TCB was greater than that for FNAHS (88.3% and 77.8%, respectively), this was not statistically significant ( P  = 0.24).
Conclusion:  If histological information is required, TCB is superior to FNAHS. The difference in diagnostic accuracy did not reach statistical significance due to low numbers and the fact that FNAHS often enabled a cytological diagnosis.     

Maximizing collection and minimizing risk: does vacuum suction sampling increase the likelihood for misinterpretation of food web connections?

Molecular tools that characterize the structure of complex food webs and identify trophic connectedness in the field have become widely adopted in recent years. However, characterizing the intensity of predator-prey interactions can be prone to error. Maximizing collection success of small, fast-moving predators with vacuum suction samplers has the potential to increase the likelihood of prey DNA detection either through surface-level contamination with damaged prey or direct consumption within the sampling device. In this study, we used PCR to test the hypothesis that vacuum suction sampling will not cause an erroneous increase in the detection of 'predation', thereby incorrectly assigning trophic linkages when evaluating food web structure. We utilized general (1) Aphidoidea and (2) Collembola primers to measure the predation rates of Glenognatha foxi (Araneae: Tetragnathidae) on these prey collected by hand versus those sampled with a vacuum suction device. With both primer pairs, there was no significant increase in predators screening positive for prey DNA when sampled by vacuum suction versus those predators collected, in parallel, by hand. These results clearly validate the application of vacuum suction sampling during molecular gut-content analysis of predator-prey feeding linkages in the field. Furthermore, we found no evidence that predation was occurring inside the suction sampler because specimens collected were never observed to be feeding nor did they screen positive at greater frequencies than hand-collected individuals. Therefore, it can be concluded that the use of vacuum suction sampling devices (in this case a Modified CDC Backpack Aspirator Model 1412) is suitable for molecular gut-content analysis.     

How do sucker‐footed bats hold on,and why do they roost head‐up?

Individuals of most bat species hang head‐down by their toenails from rough surfaces, but Madagascar's endemic sucker‐footed bat (Myzopoda aurita) clings head‐up to smooth leaves using specialized pads on its wrists and ankles. We investigated the adhesive performance of 28 individuals and found that attachment performance on brass was not affected by the presence or absence of a seal around the pad–surface interface. Furthermore, on smooth acrylic, the wrist pads were more than nine‐fold weaker when lifted perpendicular to the surface than when pulled parallel to it. The unimportance of a seal and the difference in strength in those directions on a smooth surface are characteristic of wet adhesion, but not of suction. Thus, despite its name, the sucker‐footed bat appears to adhere using wet adhesion. We observed that when wrist pads were pushed anteriorly, they unpeeled easily from the surface because of deformation of the pads. This most likely permits rapid detachment during crawling, but would also cause passive detachment if bats roosted head‐down. This provides an ecomorphological explanation to the head‐up roosting behaviour of these unique bats. The results obtained in the present study thus link morphology, behaviour, and roosting ecology for an enigmatic Malagasy endemic. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99 , 233–240.     

Large‐scale migration synchrony between parasitoids and their host

1. Parasitoids are a valuable group for conservation biological control. In their role as regulators of aphid pests, it is critical that their lifecycle is synchronised with their hosts in both space and time. This is because a synchronised parasitoid community is more likely to strengthen the overall conservation biological control effect, thus damping aphid numbers and preventing potential outbreaks. One component of this host–parasitoid system was examined, that of migration, and the hypothesis that peak summer parasitoid and host migrations are synchronised in time was tested. 2. Sitobion avenae Fabricius and six associated parasitoids were sampled from 1976 to 2013 using 12.2‐m suction‐traps from two sites in Southern England. The relationship between peak weekly S. avenae counts and their parasitoids was quantified. 3. Simple regression models showed that the response of the peak parasitoids to the host was positive: generally, more parasitoids migrated with increasing numbers of aphids. Further, when averaged over time, the parasitoid migration peak date corresponded with the aphid migration peak. The co‐occurrence of the peaks was between 51% and 64%. However, the summer peak in aphid migration is not steadily shifting forward with time unlike spring first flights of aphids. Cross‐correlation analysis showed that there were no between‐year lagged effects of aphids on parasitoids. 4. These results demonstrate that the peak in migration phenology between host and parasitoid is broadly synchronised within a season. Because the threshold temperature for flight (> 12 °C) was almost always exceeded in summer, the synchronising agent is likely to be crop senescence, not temperature. Studies are needed to assess the effects of climate change on the mismatch potential between parasitoids and their hosts.     

Using dive behavior and active acoustics to assess prey use and partitioning by fin and humpback whales near Kodiak Island,Alaska

Near the Kodiak Archipelago, fin (Balaenoptera physalus) and humpback (Megaptera novaeangliae) whales frequently overlap spatially and temporally. The Gulf Apex Predator‐prey study (GAP) investigated the prey use and potential prey partitioning between these sympatric species by combining concurrent analysis of vertical whale distribution with acoustic assessment of pelagic prey. Acoustic backscatter was classified as consistent with either fish or zooplankton. Whale dive depths were determined through suction cup tags. Tagged humpback whales (n = 10) were most often associated with distribution of fish, except when zooplankton density was very high. Associations between the dive depths of tagged fin whales (n = 4) and the vertical distribution of either prey type were less conclusive. However, prey assessment methods did not adequately describe the distribution of copepods, a potentially significant resource for fin whales. Mean dive parameters showed no significant difference between species when compared across all surveys. However, fin whales spent a greater proportion of dive time in the foraging phase than humpbacks, suggesting a possible difference in foraging efficiency between the two. These results suggest that humpback and fin whales may target different prey, with the greatest potential for diet overlap occurring when the density of zooplankton is very high.     

A large improved rotary trap for sampling aerial invertebrates

A large rotary trap designed to measure aerial spider density is described. A comparison of the rotary trap catch and a suction trap catch of spiders and other invertebrate groups showed that the rotary trap was operating at a greater efficiency for most groups. For spiders and non-staphylinid beetles the two traps caught equal numbers. There were no differences in the species composition of spiders between the rotary and suction trap catch.     

Modified micro suction cup/rhizobox approach for the in-situ detection of organic acids in rhizosphere soil solution

Root–soil interactions can strongly influence the soil solution chemistry in the rhizosphere. In the present study we propose a modification of the classical rhizobox/micro suction cup system to make it suitable for the collection and analysis of organic acids in the rhizosphere. In order to show the potential of the method, we tested the modified system with Lupinus albus L. as a model plant known to exude large amounts of citrate. The suction cups were installed through the transparent front plate of the rhizoboxes just after the emergence of cluster roots in order to allow optimal localized collection of soil solution. A small dead-volume allowed almost immediate stabilisation with formaldehyde of the sampled soil solutions in the collection container to prevent microbial degradation. The concentrations of organic acids were significantly larger in the rhizosphere soil solution of active cluster roots of Lupinus albus L. than in the bulk soil solution (about 400 μM of citrate versus <0.05 μM). We were able to follow the exudation process in-situ, which occurred during 2–3 days. Also the concentrations of other organic acids and inorganic anions differed between the bulk soil and the rhizosphere of cluster roots, normal roots, and nodules.     

Detection of feeding behaviour in common carp Cyprinus carpio by using an acceleration data logger to identify mandibular movement

Miniaturized acceleration data loggers were attached to the lower mandible of common carp Cyprinus carpio to remotely identify feeding behaviour. Whether the acceleration signal could distinguish the quantity and quality of food was also investigated. The frequency and amplitude of the lower mandible stroke, calculated from surging acceleration determined by continuous wavelet transformation, significantly increased during the feeding period compared to that during the non-feeding period. These characteristic movement patterns were maintained for mean ±s.e. 187·3 ± 38·2 s when the fish were fed a single item of food and for mean ±s.e. 419·3 ± 28·6 s when they consumed multiple items. The dominant cycle and amplitude calculated according to feeding event duration, however, did not differ significantly between the two types of diets the fish consumed. Surging acceleration could detect mean ±s.e. 89·8 ± 13·5% of feeding events, although the false detection rate was mean ±s.e. 25·9 ± 10·9%. The results indicate that the mandible acceleration measurement method could be utilized to detect and record the feeding events in fishes that use a suction feeding mode similar to C. carpio.