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991.
992.
The attractiveness of herbivore-induced plant volatiles (HIPVs) from a specific plant species to natural enemies has been well established. However, under natural conditions and polycultural agriculture systems, the interactions among trophic levels are thought to be more complex. For instance, complex mixtures of volatiles emitted from diverse host plant species infested by polyphagous herbivores might affect responses of natural enemies. In this study, we investigated whether a mixture of HIPVs emitted from herbivore-damaged multiple host plant species affect responses of a predatory bug. Therefore, we report (1) olfactory responses of the predatory bug (Orius strigicollis) to volatiles emitted from cotton bollworm (Helicoverpa armigera) first instar larvae-damaged multiple plant species (tomato, French bean and sweet corn), (2) chemical analyses of volatiles emitted from the three plant species exposed to different treatments and (3) olfactory responses of the predators to a reconstituted HIPV blend from multiple plant species based on chemical analyses. O. strigicollis significantly preferred volatiles emanating from H. armigera-damaged multiple plant species to volatiles emanating from a single plant species. In all the three plant species, H. armigera-damaged seedlings emitted significantly a greater amount of volatiles as well as a larger number of volatile compounds than an undamaged or a mechanically injured seedling. The predators preferred the reconstituted HIPVs from multiple plant species to the reconstituted HIPVs from a single plant species. Thus, the mixture of HIPVs from multiple plant species enhanced the attractiveness to the predators. 相似文献
993.
Amy Rose Deal 《Morphology》2016,26(3-4):313-339
This paper analyzes two patterns of number marking in the DP in Nez Perce (Sahaptian) within the framework of Distributed Morphology. The first involves under-realization of plural on nouns. Number has classically been understood as a feature inherent to nouns, rather than to adjectives that modify them. In Nez Perce, however, only a small set of nouns show number morphology, whereas number morphology is highly productive on adjectival modifiers. Adjectives in fact may realize the plural more than once per word—an instance of multiple exponence. I show that the puzzle of under-realization for nouns can be solved through conditioned allomorphy, providing new evidence for the presence of gender features on n (Lowenstamm 2007; Kramer 2014). The puzzle of multiple exponence (over-realization) for adjectives can be solved through Local Dislocation (Embick and Noyer 2001) combined with very late insertion of reduplicative content (Haugen 2008, 2011), demonstrating one way the DM architecture may produce multiple exponence without recourse to dedicated mechanisms. 相似文献
994.
Building on previous work, we derive an optimization model for a two-state stochastic environment and evaluate the fitnesses of five reproductive strategies across generations. To do this, we characterize spatiotemporal variation and define grain (=patch) size as the scale of fitness autocorrelation. Fitness functions of environmental condition are Gaussian. The strategies include two specialists on each of the environmental conditions; two generalists that each fare equally well under both conditions, but one (a conservative bet hedger) optimizes the shape of the fitness function; and a diversified bet hedger producing an optimal mix of the two specialists within individual broods. When the environment is primarily in one of the two states, the specialist on that state achieves the highest fitness. In the more interesting situation where the two environments are equally prevalent in the long term, with low-moderate environmental variation, a generalist strategy (that copes with both states well) does best. Higher variation favors diversified bet hedgers, or surprisingly, specialists, depending mainly on whether spatial or temporal variation predominates. These strategies reduce variance in fitness and optimize the distribution of offspring among patches differently: specialists by spreading offspring among many independently varying patches, while diversified bet hedgers put all offspring into a few patches or a single patch. We distinguish features consistent with strategies like diversified bet hedgers that spread risk in time from features linked to strategies like specialists that spread risk in space. Finally, we present testable hypotheses arising from this study and suggest directions for future work. 相似文献
995.
996.
Terrence W. Deacon 《Biosemiotics》2016,9(1):121-128
Contemporary textbooks often define evolution in terms of the replication, mutation, and selective retention of DNA sequences, ignoring the contribution of the physical processes involved. In the closing line of The Origin of Species, however, Darwin recognized that natural selection depends on prior more basic living functions, which he merely described as life’s “several powers.” For Darwin these involved the organism’s capacity to maintain itself and to reproduce offspring that preserve its critical functional organization. In modern terms we have come to recognize that this involves the continual generation of complex organic molecules in complex configurations accomplished with the aid of persistent far-from-equilibrium chemical self-organizing and self-assembling processes. But reliable persistence and replication of these processes also requires constantly available constraints and boundary conditions. Organism autonomy further requires that these constraints and co-dependent dynamics are reciprocally produced, each by the other. In this paper I argue that the different constraint-amplifying dynamics of two or more self-organizing processes can be coupled so that they reciprocally generate each other’s critical supportive boundary conditions. This coupling is a higher-order constraint (which can be distributed among components or offloaded onto molecular structures) that effectively constitutes a sign vehicle “interpreted” by the synergistic dynamics of these co-dependent self-organizing process so that they reconstitute this same semiotic-dynamic relationship and its self-reconstituting potential in new substrates. This dynamical co-dependence constitutes Darwin’s “several powers” and is the basis of the biosemiosis that enables evolution. 相似文献
997.
Kalevi Kull 《Biosemiotics》2016,9(1):61-71
Any biological species of biparental organisms necessarily includes, and is fundamentally dependent on, sign processes between individuals. In this case, the natural category of the species is based on family resemblances (in the Wittgensteinian sense), which is why a species is not a natural kind. We describe the mechanism that generates the family resemblance. An individual recognition window and biparental reproduction almost suffice as conditions to produce species naturally. This is due to assortativity of mating which is not based on certain individual traits, but on the difference between individuals. The biosemiotic model described here explains what holds a species together. It also implies that boundaries of a species are fundamentally fuzzy, and that character displacement occurs in case of sympatry. Speciation is a special case of discretisation that is an inevitable result of any communication system in work. The biosemiotic mechanism provides the conditions and communicative restrictions for the origin and persistence of diversity in the realm of living (communicative and semiotic) systems. 相似文献
998.
Background
The mechanism of db-cAMP regulating fat deposition and improving lean percentage is unclear and needs to be further studied.Methods
Eighteen 100-day-old Duroc × Landrance × Large White barrows (49.75?±?0.75 kg) were used for experiment 1, and 15 eighteen 135-day-old barrows (78.34?±?1.22 kg) were used for experiment 2 to investigate the effects of dietary dibutyryl-cAMP (db-cAMP) on fat deposition in finishing pigs. Pigs were fed with a corn-soybean meal-based diet supplemented with 0 or 15 mg/kg db-cAMP, and both experiments lasted 35 days, respectively.Results
The results showed that db-cAMP decreased the backfat thickness, backfat percentage, and diameter of backfat cells without changing the growth performance or carcass characteristics in both experiments, and this effect was more marked in experiment 1 than in experiment 2; db-cAMP enhanced the activity of the growth hormone–insulin-like growth factor-1 (GH-IGF-1) axis and pro-opiomelanocortin (POMC) system in both experiments, which suppressed the accumulation of backfat deposition; microarray analysis showed that db-cAMP suppressed the inflammatory system within the adipose tissue related to insulin sensitivity, which also reduced fat synthesis.Conclusions
In summary, the effect of db-cAMP on suppressing fat synthesis and accumulation is better in the earlier phase than in the later phase of finishing pigs, and db-cAMP plays this function by increasing the activity of the GH-IGF-1 axis and POMC system, while decreasing the inflammatory system within the adipose tissue related to insulin sensitive or lipolysis.999.
1000.
Starch extracted from ensete (Ensete ventricosum, Musaceae) also called false banana, was modified by hydrothermal methods of annealing (ANN) and heat moisture treatment (HMT) processes. The effects of treatments on functional, pasting properties, morphology and diffraction pattern of the starch were studied. Swelling power and solubility changed significantly (p < 0.05) with modification. Water absorption (89.3–152.4 %) and oil absorption (105.0–161.3 %) capacities increased significantly (p < 0.05) with ANN and HMT. Alkaline water retention decreased with ANN but increased significantly (p < 0.05) with HMT. Hydrothermal modifications led to reduction in least gelation capacity of ensete starch. In terms of the pasting properties studied, the hydrothermal modifications imparted improved gel strength, increased paste stability, reduced retrogradation tendency and slowed staling rate on ensete starch. Scanning electron micrographs depicted fairly angular and elliptical shapes with diverse sizes for the starch granules. Clustering of granules, mucilage formation, fissures and surface indentation which were gaining prominence with increasing moisture level and temperature of treatment were the hallmarks of modified samples. Native and modified ensete starches showed similar type-B diffraction pattern with maximum peak range of 19.8–20.0o (2θ). Findings of this work showed that hydrothermally modified ensete starches possess excellent value-added potentials for utilization in pharmaceuticals and food applications. 相似文献