佳木斯台形变观测对东北地区几次浅震“场兆”异常的探讨

大地震在主破裂前往往行成地壳变形,高应力作用下进入峰值后的变形阶段,反映到地倾斜观测日均值曲线上,表现为固体潮形变趋势异常,这些异常能否指示远距离的地震,近年来不少研究者发现,远场前兆往往出现在对应力、应变变化反应灵敏的特殊构造部位。佳木斯台可能处于这种特殊的构造部位,对东北地区浅源地震短期前兆异常“场兆”的趋势性变化具有一定的意义。     

Utilization of selected area electron diffraction patterns for characterization of air submicron particulate matter collected by a thermophoretic precipitator

A thermophoretic precipitator (TP) that uses a novelty of direct sampling of ambient air particulate matter (PM) onto transmission electron microscopy (TEM) grids was designed and utilized to determine its potential applicability for the collection and consequent qualitative analyses of representative PM in the air, especially those with aerodynamic diameter less than 1 microm (PM1.0). After a calibration process, preliminary field tests were performed under different weather conditions, locations, and time frames. TEM, selected area electron diffraction (SAED), and electron energy-dispersive X-ray spectrometry (EDS) analyses were performed on individual samples, and chemical species were analyzed. During this investigation, individual air PM with different sizes ranging from 10 microm to 10 nm for TEM analysis was collected. Two observations were made: (1) a large fraction of collected particulates were aggregates of very small particles of both organic and inorganic origin, and (2) a large fraction of the collected particulates were crystalline or polycrystalline. This study has demonstrated, by utilization of SAED patterns from TEM on air particles collected by a TP, the potential to analyze and identify individual air PM in a nanometer regime qualitatively by combining SAED and EDS data.     

Functional interactions among tortoise beetle larval defenses reveal trait suites and escalation

Whereas the “escape-and-radiate” plant-herbivore scenario predicts that reciprocating cycles of defense-counter defense foster the evolution of traits with increasing efficacy that accumulate during clade diversification, coevolutionary models of herbivore responses to their enemies remain unexplored. Quantitative information is scarce about how defensive traits perform, interact and become functionally integrated. Moreover, there are few studies that have combined performance and phylogenetic information to detect patterns of trait assembly and trends in defense efficacy. Using field demonstrations of effectiveness and phylogenetic reconstructions, we evaluated patterns of trait precedence and suite assembly by comparing the larval defenses of two beetles, Acromis sparsa and Chelymorpha alternans, which both feed on the leaf surfaces of the same plant, have shields containing host-derived deterrent chemicals and form aggregations. Additionally, female A. sparsa guard their larvae. Using an ecologically relevant bioassay, we quantified the extent to which: (1) gregariousness, size, maternal care and shields affected survival; (2) defenses interacted, and; (3) derived traits and suites outperformed ancestral ones. Regression models ranked traits revealing synergistic interactions. Shields interacted with gregariousness to form the strongest suite. Maternal care contributed to overall higher survival in A. sparsa, an advantage lost after female removal. Phylogenetic reconstruction revealed a sequence of trait accumulation and suite formation. The combined performance-phylogenetic approach revealed: (1) multi-trait interactions amplified effectiveness; (2) a sequence of novel trait origins was followed by suite assembly, and; (3) an incremental trend in defense efficacy congruent with escalation. Multi-trait interactions fostered suite assembly that likely conferred the advantage of enhanced survival in the precarious leaf surface adaptive zone.     

Silk wrapping of nuptial gifts as visual signal for female attraction in a crepuscular spider

An extensive diversity of nuptial gifts is known in invertebrates, but prey wrapped in silk is a unique type of gift present in few insects and spiders. Females from spider species prefer males offering a gift accepting more and longer matings than when males offered no gift. Silk wrapping of the gift is not essential to obtain a mating, but appears to increase the chance of a mating evidencing a particularly intriguing function of this trait. Consequently, as other secondary sexual traits, silk wrapping may be an important trait under sexual selection, if it is used by females as a signal providing information on male quality. We aimed to understand whether the white color of wrapped gifts is used as visual signal during courtship in the spider Paratrechalea ornata. We studied if a patch of white paint on the males’ chelicerae is attractive to females by exposing females to males: with their chelicerae painted white; without paint; and with the sternum painted white (paint control). Females contacted males with white chelicerae more often and those males obtained higher mating success than other males. Thereafter, we explored whether silk wrapping is a condition-dependent trait and drives female visual attraction. We exposed good and poor condition males, carrying a prey, to the female silk. Males in poor condition added less silk to the prey than males in good condition, indicating that gift wrapping is an indicator of male quality and may be used by females to acquire information of the potential mate.