Photoelectric sensing device for recording mosquito host-seeking behavior in the laboratory

A new automatic device for recording the host-seeking behavior of mosquitoes was designed using photoelectric sensors. The host-seeking rhythms of several species of mosquitoes were recorded under laboratory conditions. Use of CO2, in addition to heating and black color to activate mosquito flight proved to be important for evaluation of the present recording device. The diel rhythms of non bloodfed Aedes albopictus, Ae. aegypti, Culex quinquefasciatus, Cx. tritaeniorhynchus, and Anopheles stephensi females recorded by the device corresponded well with known flight and activity rhythms in field for the same mosquito species. This simple automatic recording device provided accurate information on the flight behaviors of colonized and field collected mosquitoes

Metal-supported SOFC Fabricated by Tape Casting and Its Characterization: A Study of the Co-sintering Process

Metal-supported SOFC consists of metallic and ceramic multilayers. Since the cell has to be flat, interaction between the layers that results in a flat sintered layer needs to be studied. The method used here was changing the starting materials through several experiments. Here, we highlight the effects of pore former in metal slurry on the sintered half-cell multilayer of a 430L metallic support, an NiO-8YSZ anode, and an 8YSZ electrolyte. The results show that by changing the amount of pore former in the 430L metal slurry changed the sinterability of the metal layer. This change of the sinterability of the metal support affected the final warpage state of the cell. This study aid in explaining the sintering phenomena between layers of metal-supported SOFCs

Field trial of the spatial repellency of metofluthrin-impregnated plastic strip against mosquitoes in shelters without walls (Beruga) in Lombok, Indonesia.

Field trials on the spatial repellency of metofluthrin-impregnated plastic strips for mosquitoes present in shelters without walls (beruga) were carried out in Lombok, Indonesia. A major reduction in the incidence of human biting by Culex quinquefasciatus was achieved, and the use of two strips per beruga repelled >60% of the mosquitoes for at least 11 wk while four strips repelled >60% of the mosquitoes for more than 15 weeks. The technique was found to be a practical long-term solution for the prevention of mosquito bites without using electricity or heat to evaporate the metofluthrin

Dengue Vectors and their Spatial Distribution

The distribution of dengue vectors, Ae. aegypti and Ae. albopictus, is affected by climatic factors. In addition, since their life cycles are well adapted to the human environment, environmental changes resulting from human activity such as urbanization exert a great impact on vector distribution. The different responses of Ae. aegypti and Ae albopictus to various environments result in a difference in spatial distribution along north-south and urban-rural gradients, and between the indoors and outdoors. In the north-south gradient, climate associated with survival is an important factor in spatial distribution. In the urban-rural gradient, different distribution reflects a difference in adult niches and is modified by geographic and human factors. The direct response of the two species to the environment around houses is related to different spatial distribution indoors and outdoors. Dengue viruses circulate mainly between human and vector mosquitoes, and the vector presence is a limiting factor of transmission. Therefore, spatial distribution of dengue vectors is a significant concern in the epidemiology of the disease

摂食障害と多発性自己破壊行動という特徴を有した症例における行動の遺伝学的研究について

Among a group of patients (n=65) , the majority of whom had been introduced to us by　eating-disorder specialists elsewhere because of difficulties in their treatment, we defined a　subgroup (n=39) characterized by eating disorders and multiple behavioral problems. In addition　to the disordered eating behavior, problematical behavior relating to the use of alcohol and other substances, shoplifting, promiscuity, and suicidal tendencies were seen in 74%, 36%, 33%, and 15% of the patients, respectively. Further, this subgroup showed an extremely worse outcome, when compared with the subgroup of patients with pure eating disorders (n =26). With regard to the intrafamilial traits examined among the first- and second-degree relatives, 49% of the patients had the trait for alcohol dependence, 28% had the trait for problematical behaviors. The physically or socially self-destructive types of behavior, which seemed to be attributable to vigorous and uncontrollable intrinsic impulses of the patients, tended to emerge in the respective patients in revolving or alternating manners. Therefore, enduring efforts should be taken to support the personality development of such patients rather than to struggle with respective problematical behaviors, which may be considered merely as facets of a single disorder. 多発性問題行動を有する摂食障害(EDMUL)39例を対象とし,標記検討を行った。これら症例は純粋な摂食障害に比べ予後不良であった。家族内形質としてはアルコール依存性を49%,問題行動を28%で認めた。EDMULにおける問題行動は身体的,社会的観点からの自己破壊行動であり,コントロールできない固有の衝動に基づいている可能性を示唆した。よってEDMULではそれぞれの問題行動に取り組むよりも,むしろ人間性の成長を支援する努力をすべきであると考えた

ソロモン島における昆虫成長制御剤ピリプロキシフェンの Anopheles farauti に対する野外効力評価

金沢大学留学生センター昆虫に対して高い幼若ホルモン様活性を示すピリプロキシフェン(S-31183)のAnopheles farautiに対する野外効力試験を, ソロモン諸島国, ガダルカナル島北部の淡水および半塩水の発生源で行った。その結果, ピリプロキシフェン乳剤の0.1ppm施用により, 淡水, 半塩水のいずれの発生源においても約2カ月以上にわたって70%以上の防除効果が得られた。ピリプロキシフェンの散布後に採集された幼虫および蛹が白色化しているのが観察され, 羽化阻害効果が持続する期間, この現象が続いた。 A field study to control the malarian vector, Anopheles farauti, with an insect growth regulator, pyriproxyfen (S-31183), was carried out in northern Guadalcanal in the Solomon Islands. An emulsifiable concentrate of 1% pyriproxyfen was applied to two breeding sites : one with fresh water and another with brackish water. Pyriproxyfen at a dosage of 0.1ppm inhibited emergence of An. farauti completely, at both test sites, for at least 5 weeks after treatment and the efficacy (more than 70% inhibition) lasted for ca. 2 months. The body color of the larvae and pupae in the test sites whitened noticeably after the application of the compound

Comparative study on the relationship between photoperiodic host-seeking behavioral patterns and the eye parameters of mosquitoes.

Relationships between the ommatidial structure and photoperiodic behavior of several mosquito species were investigated. Host-seeking behavioral patterns of mosquitoes were classified into 4 main groups based on previously compiled reports on field or laboratory biting activity. These groups were pattern I and I\u27 (nocturnal), pattern II (crepuscular and nocturnal), pattern III (crepuscular and diurnal), and pattern IV (diurnal). Eye parameters (product of facet diameter and interommatidial angle) of mosquitoes that belong to the pattern I and I\u27 group were higher (2.7 to 4.2) than those of mosquitoes that belong to the pattern IV group (0.8 to 2.3). Eye parameters of the mosquitoes categorized in the pattern II and III groups were intermediate (2.3 to 2.6). These result suggest that the crepuscular behavior of mosquitoes undergoes a transition in the course of evolution from nocturnal behavior to diurnal behavior. Large variations in the eye parameters were observed even within the same genus depending on their photoperiodic behavior. Therefore, the ommatidial structure of mosquitoes appears to be determined, not taxonomically, but evolutionarily by the photo-environment in which the mosquitoes are most active

Comparative study on nocturnal behavior of Aedes aegypti and Aedes albopictus.

Nocturnal behavior of non-bloodfed females of Aedes aegypti and Aedes albopictus was studied using an automatic recording device equipped with a photoelectric sensor. Carbon dioxide, heating, and the contrast of the black and white colors were used as attractive cues for mosquitoes. The nocturnal host seeking activity positively correlated with the increasing light intensity in both species. Ae. aegypti was found to be more sensitive to light than Ae. albopictus. The threshold of light intensity for the activation of the nocturnal host seeking activity was 10 lx (ca. 1 foot candle) in Ae. albopictus, respectively. Complete darkness during the daytime deactivated the host seeking activity of both species, irrespective of their increasing flight activity controlled by their intrinsic circadian rhythms. This suggested that visual cues are indispensable for host seeking behavior. The eye parameter value, the product of the ommatidial diameter, and the interommatidial angle were significantly larger in Ae. aegypti than those in Ae. albopictus, indicating that the eye of Ae. aegypti is more adapted to a darker environment.長崎大学学位論文 学位記番号:博（医）乙第1,782号 学位授与年月日:平成19年10月31

GlmS and NagB Regulate Amino Sugar Metabolism in Opposing Directions and Affect Streptococcus mutans Virulence

Streptococcus mutans is a cariogenic pathogen that produces an extracellular polysaccharide (glucan) from dietary sugars, which allows it to establish a reproductive niche and secrete acids that degrade tooth enamel. While two enzymes (GlmS and NagB) are known to be key factors affecting the entrance of amino sugars into glycolysis and cell wall synthesis in several other bacteria, their roles in S. mutans remain unclear. Therefore, we investigated the roles of GlmS and NagB in S. mutans sugar metabolism and determined whether they have an effect on virulence. NagB expression increased in the presence of GlcNAc while GlmS expression decreased, suggesting that the regulation of these enzymes, which functionally oppose one another, is dependent on the concentration of environmental GlcNAc. A glmS-inactivated mutant could not grow in the absence of GlcNAc, while nagB-inactivated mutant growth was decreased in the presence of GlcNAc. Also, nagB inactivation was found to decrease the expression of virulence factors, including cell-surface protein antigen and glucosyltransferase, and to decrease biofilm formation and saliva-induced S. mutans aggregation, while glmS inactivation had the opposite effects on virulence factor expression and bacterial aggregation. Our results suggest that GlmS and NagB function in sugar metabolism in opposing directions, increasing and decreasing S. mutans virulence, respectively