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The evolution of winged stick insects (phasmids) from secondarily wingless ancestors was proposed in recent studies. We explored
the cuticle of flying phasmids for wind sensors that could be involved in their flight control, comparable to those known
for locusts. Surprisingly, wind-sensitive hairs (wsH) occur on the palps of mouthparts and on the antennae of the winged phasmid
Sipyloidea sipylus which can fly in tethered position only when air currents blow over the mouthparts. The present study describes the morphology
and major functional properties of these “new” wsH with soft and bulging hair bases which are different from the beaker-like
hair bases of the wsH on the cerci of phasmids and the wsH described in other insects. The most sensitive wsH of antennae
and palps respond with phasic-tonic afferents to air currents exceeding 0.2 ms−1. The fields of wsH on one side of the animal respond mainly to ventral, lateral, and frontal wind on the ipsilateral side
of the head. Afferent inputs from the wsH converge but also diverge to a group of specific interneurons at their branches
in the suboesophageal ganglion and can send their integrated input from wsH fields of the palps and antennae to the thoracic
central nervous system. Response types of individual wsH-interneurons are either phasic or phasic-tonic to air puffs or constant
air currents and also, the receptive fields of individual interneurons differ. We conclude that the “new” wsH system and its
interneurons mainly serve to maintain flight activity in airborne phasmids and also, the “new” wsH must have emerged together
with the integrating interneurons during the evolution from wingless to the recent winged forms of phasmids. 相似文献
54.
Shiny Mathews Dawn Reinhold 《Environmental science and pollution research international》2013,20(7):4327-4338
Tetracyclines and sulfonamides used in human and animal medicine are released to terrestrial ecosystems from wastewater treatment plants or by direct manure application. The interactions between plants and these antibiotics are numerous and complex, including uptake and accumulation, phytometabolism, toxicity responses, and degradation in the rhizosphere. Uptake and accumulation of antibiotics have been studied in plants such as wheat, maize, potato, vegetables, and ornamentals. Once accumulated in plant tissue, organic contaminants can be metabolized through a sequential process of transformation, conjugation through glycosylation and glutathione pathways, and ultimately sequestration into plant tissue. While studies have yet to fully elucidate the phytometabolism of tetracyclines and sulfonamides, an in-depth review of plant and mammalian studies suggest multiple potential transformation and conjugation pathways for tetracyclines and sulfonamides. The presence of contaminants in the vicinity or within the plants can elicit stress responses and defense mechanisms that can help tolerate the negative effects of contaminants. Antibiotics can change microbial communities and enzyme activity in the rhizosphere, potentially inducing microbial antibiotic resistance. On the other hand, the interaction of microbes and root exudates on pharmaceuticals in the rhizosphere can result in degradation of the parent molecule to less toxic compounds. To fully characterize the environmental impacts of increased antibiotic use in human medicine and animal production, further research is essential to understand the effects of different antibiotics on plant physiology and productivity, uptake, translocation, and phytometabolism of antibiotics, and the role of antibiotics in the rhizosphere. 相似文献