Bacterially enriched diet improves sexual performance of sterile male Mediterranean fruit flies

The Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), (medfly) is a polyphagous and cosmopolitan agricultural pest, targeted in many areas for control by the Sterile Insect Technique (SIT). Our objective in the present study was to test the hypothesis that a bacterially enriched diet provided to sterile males will improve their sexual performance in competitive settings that emulate natural conditions. Specifically we determined how feeding on diets enriched with Klebsiella oxytoca affected the ability of sterile males to compete for wild females against wild males, their ability to inhibit female receptivity, and their survival. We found that enriching the sterile male diet with K.oxytoca significantly improved mating competitiveness in the laboratory and in field cages. In addition, bacterially enriched sterile males inhibited female receptivity more efficiently than sugar fed males and survived longer duration of starvation. We conclude that inoculating mass reared sterile flies with bacteria prior to their release is a valid approach to improve the efficacy of SIT.     

Managing invasive crayfish: use of X-ray sterilisation of males

1. In the last decade, many attempts have been made to contain the spread of the North American crayfish Procambarus clarkii , an invader of many European water bodies, but none has been successful.
2. This study investigates the effects that ionising irradiation has on the reproduction of P. clarkii males by analysing the behaviour of the treated individuals, their reproductive output, the vitality and survival of their offspring and the damages induced to their gonads.
3. We found that a dose of 20 Gy X-rays did not compromise either the survival or the mating ability of males, but reduced the size of their testes and significantly altered spermatogenesis. The number of aborted eggs was larger in clutches sired by treated males, with a consequent reduction (by 43%) in the number of offspring.
4. These results foster hopes in our efforts to control invasive crayfish, showing the potential effectiveness of ionising irradiation to reduce male fertility in the perspective of adopting the Sterile Male Release Technique to control P. clarkii populations.     

Release of Sterile Mediterranean Fruit Flies, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), Using an Automated Ground Release Vehicle

A trial was conducted in Tampa, Florida to test an automated ground release machine as an alternative to aerial methods for release of sterile Mediterranean fruit flies, Ceratitis capitata (Wiedemann). Twenty-four Jackson traps baited with trimedlure at three release sites yielded lower than expected numbers of ground released Medflies. Recaptures per trap ranged from 2.8 (±0.7 S.E.) to 6.8 (±1.7 S.E.). Average recovery of sterile flies at each site for all releases combined (144 observations) was similar, 3.4 (±0.5 S.E.), 4.4 (±0.5 S.E.), 4.5 (±0.5 S.E.) for sites 1, 2 and 3 respectively. There was a significant reduction in flight ability from 67.5 (±2.1 S.E.) to 53.6 (±2.9 S.E.)%, from the time of pre-chilling to when immobilized flies were released after 2.5 h in the release container. Further tests are needed to determine what mortality factors may influence recovery and how the automated ground release machine compares to the aerial release method.     

Some aspects of the Upper Palaeolithic period in Sindh,Pakistan

The study of the Upper Palaeolithic of Sindh is still in its infancy. Although it has slightly improved during the last twenty years, and a few more sites have been discovered in different parts of the province, we are still far from achieving a good knowledge of the sequence of the events that took place during the final stages of the Pleistocene in this region of the Indian Subcontinent. Despite the archaeological importance of the southern part of the country, the Arabian Sea coast in particular, which represents the suggested route followed by Modern Humans to move to India and farther east, most of this territory has not yielded any tangible trace of their passage. The scope of this paper is to update the evidence available for the Upper Palaeolithic of Sindh, and to discuss it within the general framework of the Upper Palaeolithic period of the Indian Subcontinent.     

IPM计算机决策技术简述

害虫综合管理的对象是一个复杂的生态系统。计算机已成为操纵这种复杂系统的有效决策工具。ＩＰＭ统计分析,模型生成,生态过程模拟和数据管理是计算机辅助决策的初级形式。在此基础上,ＩＰＭ决策过程的计算机化在近几年达到了很高的程度,出现了ＩＰＭ决策支持和专家系统。这标志着ＩＰＭ科学决策时代的到来。在某种意义上,计算机软硬件的技术进步改变了ＩＰＭ的过去,影响着ＩＰＭ的现在,决定着ＩＰＭ的未来。     

Surgical Technique for the Implantation of Tissue Engineered Vascular Grafts and Subsequent In Vivo Monitoring

The development of Tissue Engineered Vessels (TEVs) is advanced by the ability to routinely and effectively implant TEVs (4-5 mm in diameter) into a large animal model. A step by-step protocol for inter-positional placement of the TEV and real-time digital assessment of the TEV and native carotid arteries is described here. In vivo monitoring is made possible by the implantation of flow probes, catheters and ultrasonic crystals (capable of recording dynamic diameter changes of implanted TEVs and native carotid arteries) at the time of surgery. Once implanted, researchers can calculate arterial blood flow patterns, invasive blood pressure and artery diameter yielding parameters such as pulse wave velocity, augmentation index, pulse pressures and compliance. Data acquisition is accomplished using a single computer program for analysis throughout the duration of the experiment. Such invaluable data provides insight into TEV matrix remodeling, its resemblance to native/sham controls and overall TEV performance in vivo.     

The control of twisting somersaults

In the takeoff and early flight phase of a twisting somersault, joint coordination is based on feed-forward control whereas in the late stages of the flight phase configuration adjustments are made using feedback control to ensure accurate completion of the movement and appropriate landing orientation. The aim of this study was to use a computer simulation model of aerial movement to investigate the extent to which arm and hip movements can control twist and somersault rotation in the flight phase of a twisting somersault. Two mechanisms were considered for the control of twist in simulated target trampoline movements with flight times of 1.4 s. In the first case a single symmetrical arm adduction correction was made using delayed feedback control based on the difference between the twist rate in a perturbed simulation and the twist rate in a target movement comprising a forward somersault with 1½ twists. Final corrections were made using symmetrical arm abduction and hip flexion to adjust the twist and somersault angles. In the second case continual asymmetrical arm adduction/abduction adjustments were used to remove the tilt from a perturbed full twisting backward somersault using delayed feedback control based on twist angle and angular velocity. The first method was able to cope with perturbations to a forward somersault with 1½ twists providing the feedback time delay was less than 200 ms. The second method was able to correct a perturbed full twisting backward somersault providing the feedback time delay was less than 125 ms.     

The influence of touchdown conditions and contact phase technique on post-flight height in the straight handspring somersault vault

In vaulting the gymnast must generate sufficient linear and angular momentum during the approach and table contact in order to complete the rotational requirements in the post-flight phase. This study investigated the effects of touchdown conditions and contact technique on peak post-flight height of a straight handspring somersault vault. A planar seven-segment torque-driven computer simulation model of the contact phase in vaulting was evaluated by varying joint torque activation time histories to match three performances of a straight handspring somersault vault by an elite gymnast. The closest matching simulation was used as a starting point to optimise peak post-flight height of the mass centre for a straight handspring somersault. It was found that optimising either the touchdown conditions or the contact technique increased post-flight height by 0.1 m whereas optimising both together increased post-flight height by 0.4 m above that of a simulation matching the recorded performance. Thus touchdown technique and contact technique make similar contributions to post-flight height in the straight handspring somersault vault. Increasing touchdown velocity and angular momentum lead to additional post-flight height although there was a critical value of vertical touchdown velocity beyond which post-flight height decreased.     

Muscle activity and spine load during pulling exercises: Influence of stable and labile contact surfaces and technique coaching

This study examined pulling exercises performed on stable surfaces and unstable suspension straps. Specific questions included: which exercises challenged particular muscles, what was the magnitude of resulting spine load, and did technique coaching influence results. Fourteen males performed pulling tasks while muscle activity, external force, and 3D body segment motion were recorded. These data were processed and input to a sophisticated and anatomically detailed 3D model that used muscle activity and body segment kinematics to estimate muscle force, in this way the model was sensitive to each individual’s choice of motor control for each task. Muscle forces and linked segment joint loads were used to calculate spine loads. There were gradations of muscle activity and spine load characteristics to every task. It appears that suspension straps alter muscle activity less in pulling exercises, compared to studies reporting on pushing exercises. The chin-up and pull-up exercises created the highest spine load as they required the highest muscle activation, despite the body “hanging” under tractioning gravitational load. Coaching shoulder centration through retraction increased spine loading but undoubtedly adds proximal stiffness. An exercise atlas of spine compression was constructed to help with the decision making process of exercise choice for an individual.