264 research outputs found

    Nest size variation reflecting anti-predator strategies in social spider mites of Stigmaeopsis (Acari: Tetranychidae)

    Get PDF
    The social spider mites (Acari: Tetranychidae) of Stigmaeopsis weave dense nests on the underside of host leaves. Four species occur on the leaves of bamboo in Japan: Stigmaeopsis longus, S. celarius, S. takahashii and S. saharai. We initially reconfirmed the occurrence of distinct variation in nest size among the species. Based on the hypothesis that this variation plays a role in protecting the spider mites from predators, we looked at the behavior of the natural enemies that occur on the host plants along with members of Stigmaeopsis. We found considerable variation in the ability of nests to protect the spider mite eggs. The smallest nests protected the eggs against 3 predators, whereas the largest nests protected the eggs only against one predator species. In other words, decreases in nest size increased egg defense. Thus we concluded that nest size variation reflects a strategy for reducing predation

    Where does male-to-male aggression compromise cooperation?

    Get PDF
    We discuss how the diverse nature of aggression and cooperation can be understood if we focus our attention on where aggression reaches a compromise with non-aggression and/or cooperation in response to the relatedness between interactors. First we address whether Hamiltons rule explains the variation in male-to-male aggressiveness. Next we show that the variation in aggression and cooperation known in males of social spider mites (Saito, Evolution 49:413–417, 1995) can be explained by the change in relatedness (i.e. inclusive fitness) and effect of cooperative defence (synergistic effect). Then we learn that there is a sufficient condition of cooperation, which is determined primarily by two factors: the relatedness and synergistic effect of males. Furthermore, we expect that there is a condition where the aggression between males varies, depending upon how close the values of relatedness are to those of the sufficient condition of cooperation

    Salvage endovascular embolization of the left pulmonary artery for recurrent pseudoaneurysm

    Get PDF
    Background: Pulmonary pseudoaneurysm (PPA) is a potentially lethal complication of lung resection with a high risk of recurrence after endovascular coiling. Case presentation: We report a case in which recurrent hemoptysis due to PPA after left lower lobe sleeve resection was treated by endovascular embolization of the left main pulmonary artery as a salvage treatment. The first hemoptysis was managed by endovascular coil embolization with extracorporeal membrane oxygenation, but refractory hemorrhage occurred 3 months later due to penetration of the endovascular coil into the bronchial anastomosis site. Because left completion pneumonectomy was considered too high risk, the left main pulmonary artery was palliatively embolized using an Amplatzer vascular plug (St. Jude Medical, MN, USA) to totally disrupt the left pulmonary arterial flow. Conclusions: Total embolization of the left main pulmonary artery for repeated PPA rupture may be useful as a palliative treatment in patients unable to tolerate pneumonectomy

    Response time differences during hand mental rotation

    Get PDF
    This study explored gender differences in correct response rates and response times on a task involving left or right arrow selection and another involving the transformation of mental rotation of the hand. We recruited 15 healthy, right-handed men (age 24.5 ± 6.4) and 15 healthy, right-handed women (age 21.3 ± 4.9). For the tasks, we used pictures of left and right arrows and 32 hand pictures (left and right, palm and back) placed in cons (each at 45° from 0° to 315°). Hand and arrow pictures alternated and were shown at random. Participants decided as quickly as possible whether each picture was left or right. To compare the time taken for the transformation of mental rotation of the hand, we subtracted the average arrow response time from that for the left and right hand pictures for each participant. Correct response rates did not differ significantly between men and women or left and right for either arrow or hand pictures. Regardless of gender, the response time was longer for the left arrow picture than right arrow picture. The response time for the hand picture was longest for both men and women for pictures at rotation angles that were most difficult to align with participants’ hands. While there was no difference between men’s responses for left and right hand pictures, the responses of women were longer for left than right hand pictures and also than those of men. These findings suggest that both men and women mainly perform the hand mental rotation task with implicit motor imagery. On the other hand, the gender difference in performance might be explained by the difference in balance with other strategies, such as visual imagery, and by cognitive, neurophysiological, and morphological differences

    The potential hazard of a non-slip element balloon causing distal longitudinal stent deformation: the first clinical experience and in vitro assessment

    Get PDF
    Background: A new complication, longitudinal stent deformation (LSD), is increasingly reported withrecent intracoronary stent designs. There have been experiences of unusual cases of distal LSD causedby entrapment of a Lacrosse® non-slip element (NSE) balloon (Goodman Co., Ltd., Nagoya, Japan),which has three flexible nylon elements to prevent slippage. Accordingly, the aim of this study is to reportthe clinical experience of distal LSD caused by the NSE in the documented center and to investigate theincidence and mechanisms involved.Methods: Coronary intervention cases were retrospectively reviewed using the NSE balloon in hospitalbetween May 2014 and June 2017. In bench testing, distal LSD was reproduced in a silicon tube modelto identify its mechanism.Results: A total of 95 patients with 107 lesions underwent coronary interventions with NSE. Of these,72 lesions (12 de-novo lesions and 60 in-stent restenosis) were treated using in-stent dilatation. Twodistal LSD cases occurred, representing an incidence of 2.78% (2/72) among all procedures; 16.7%(2/12) of the de-novo lesions developed LSD. In vitro experimentation allowed indentification of themechanisms involved and bailout strategies.Conclusions: This is the first study to evaluate NSE balloon catheter entrapment complicated by distalLSD in which reconstruction of the deformed stent and retrieval of the NSE could be achieved successfully.There is a potential hazard for distal LSD during post-dilatation using the NSE balloon due to itsstructural characteristics. Careful assessment is needed to prevent this complication
    corecore