The effect of entomopathogenic nematodes and fungi against four xylophagous pests

The effects of entomopathogenic nematodes EPN (Steinernematidae and Heterorhabditidae) and fungi EPF (Beauveria bassiana) strains were evaluated in laboratory assays against larvae of four xylophagous pests: the Asparagus moth Parahypopta caestrum, the European goat moth Cossus cossus, the pine longhorn Arhopalus syriacus and the black Buprestid Capnodis tenebrionis. Due to their biology and ethology, these insects may be included in the category of pests residing in cryptic habitats. The control of these species is considered difficult, due to the inability of chemical pesticides to penetrate the cryptic habitats and reach the targets. The pathogenicity of the entomopathogenic nematodes and fungi was tested in vitro against the pests. Two experimental models were considered and aimed to imitate the natural environment of the pests, in Petri dishes filled with plant material and inside wood galleries respectively. Main results showed that the majority of the tested strains of nematodes and fungi affected the insects’ survival rate. Steinernema feltiae and B. bassiana caused the highest percentage of larval mortality (80–100%). Considering the lack of effective chemical control means, the microbial control of the xylophagous pests by EPN and EPF reveals promising perspectives. Nematodes and fungi are able to penetrate the cryptic habitats because they are living organisms and may be horizontally transmitted by infected hosts. The distribution of EPF as preventive control method and the injection of EPN suspensions to reach and infect the larvae inside the wood galleries can be a combined sustainable control system

Fixed-frequency beam-steerable leaky-wave antennas

grantor: University of TorontoA detailed description of the fundamentals of operation of two fixed-frequency beam-steerable leaky-wave antennas developed during the course of this research is presented. This is accompanied by measurements used to validate the theories developed herein. A study is presented of the wave propagation along the first of these antennas, a periodically loaded leaky-wave microstrip. The theoretical predictions linking the phase velocity along such an antenna to the values of the voltage-controlled capacitors placed at regular intervals along it are verified experimentally. It is found that the phase velocity along the antenna can be varied continuously by properly adjusting the DC voltage across its capacitors. This effect is used to achieve continuous fixed-frequency main-beam steering. Analysis is also given of the wave propagation along the second antenna, a leaky waveguide made up of a set of parallel strips periodically loaded with voltage-controlled capacitors and printed on a grounded dielectric slab. It is found that the phase velocity along such an antenna, and thus the direction of its main-beam maximum can be controlled continuously at constant frequency by properly adjusting the DC voltage across its capacitors. Finally, the effect of the dielectric constant on the scan range of fixed-frequency periodically loaded leaky-wave microstrip and leaky-waveguide antennas is addressed. Expressions for the radiation efficiency, power gain, radiated power, and power dissipated in the various parts of these antennas are derived. In addition, the response of these antennas to harmonic and intermodulation interference is experimentally investigated, and is followed by a set of measurements that address the issue of radiation from the sides of leaky-waveguide antennas.Ph.D

Decompression and Enucleation of a Mandibular Radicular Cyst, Followed by Bone Regeneration and Implant-Supported Dental Restoration

Odontogenic cysts are usually treated by enucleation (cystectomy). Limited cysts (less than 5 cm) are usually managed by primary excision (total cystectomy), whereas larger ones (exceeding 5 cm) are often decompressed or marsupialized. Because it consists only of opening a much smaller surgical window, decompression is regarded as a more conservative method of treatment: this method associates the creation of an opening (window) into the cystic cavity with the suturing of a decompressing device (plastic tube or stent) at the periphery of the cyst. Apart from releasing intraluminal pressure in the pathological cavity, this procedure helps the lesion to progressively decrease in volume “with a gradual increase in bone apposition” and preserves pulp vitality and periodontal integrity of the adjacent teeth. We are reporting a case of a mandibular radicular cyst that was treated by decompression, followed by enucleation, bone reconstruction, and restoration with two osseointegrated dental implants. The cystic cavity progressively decreased in volume and increased in bone density

Effect of Temperature on the Infectivity of different Entomopathogenic Nematodes (Steinernematidae and Heterorhabditidae) Isolated from Natural Ecosystems

International audienc

Diagnosis of external root resorption in teeth close and distant to zirconium implants : influence of acquisition parameters and artefacts produced during cone beam computed tomography

To assess the influence of artefacts, the metal artefact reduction (MAR) tool and kilovoltage (kVp) on the diagnosis of simulated external root resorption (ERR) in teeth close and distant to zirconium implants in cone beam computed tomography (CBCT) images. Methodology Cavities (0.62 mm in diameter and 0.19 mm deep) were created in the apical thirds of 12 roots on the buccal, lingual, distal or mesial surface; ten roots served as controls. The roots were randomly positioned in the first and second right and left premolar sockets of a dry human mandible, and a zirconium implant was placed in the socket of the first right molar. A ProMax 3D unit varying kVp (70, 80, or 90 kVp) and with the MAR tool activated or not was used to obtain CBCT scans. Five examiners evaluated all images to determine the area under the receiver operating characteristic (ROC) curve, sensitivity and specificity. The ROC values and sensitivity were not affected by MAR or artefacts regardless of the distance to the implant (P > 0.05), whilst increasing kVp from 70 to 90 led to a significant increase in these values (P = 0.0202 and 0.0199, respectively). Specificity was not affected by the factors studied (P > 0.05). Amongst the factors studied, only kVp influenced the diagnosis of simulated external root resorption in CBCT images. Increasing kVp from 70 to 90 improved the accuracy in diagnosing the simulated lesions526866873COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES88881.118874/2016-0

Potential microbial control of xylophagous pests with entomopathogenic nematodes and fungi.

The effects of entomopathogenic nematodes (Steinernematidae and Heterorhabditidae) and fungi strains (Beauveria bassiana) were evaluated in laboratory assays against larvae of four xylophagous pests: the Asparagus moth Parahypopta caestrum, the European goat moth Cossus cossus, the pine longhorn Arhopalus syriacus and the black Buprestid Capnodis tenebrionis. Due to their biology and ethology, these insects may be included in the category of pests residing in cryptic habitats. The control of these species is very difficult, due to the inability of chemical pesticides to penetrate the cryptic habitats and reach the targets. The results showed that all the nematodes and fungal strains affected the insect survival. Steinernema feltiae and Beauveria bassiana showed the best performances. Considering the lack of effective chemical control means, the microbial control of the xylophagous pests by EPNs and EPFs reveals promising perspectives. Nematodes and fungi are able to penetrate the cryptic habitats because they are living organisms and may be horizontally transmitted by infected hosts. The distribution of EPF as preventive control method and the injection of EPNs suspensions to reach and infect the larvae inside the wood galleries can be a combined sustainable control system