41 research outputs found

    Volatile Organic Compounds Emitted by Fungal Associates of Conifer Bark Beetles and their Potential in Bark Beetle Control

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    Conifer bark beetles attack and kill mature spruce and pine trees, especially during hot and dry conditions. These beetles are closely associated with ophiostomatoid fungi of the Ascomycetes, including the genera Ophiostoma, Grosmannia, and Endoconidiophora, which enhance beetle success by improving nutrition and modifying their substrate, but also have negative impacts on beetles by attracting predators and parasites. A survey of the literature and our own data revealed that ophiostomatoid fungi emit a variety of volatile organic compounds under laboratory conditions including fusel alcohols, terpenoids, aromatic compounds, and aliphatic alcohols. Many of these compounds already have been shown to elicit behavioral responses from bark beetles, functioning as attractants or repellents, often as synergists to compounds currently used in bark beetle control. Thus, these compounds could serve as valuable new agents for bark beetle management. However, bark beetle associations with fungi are very complex. Beetle behavior varies with the species of fungus, the stage of the beetle life cycle, the host tree quality, and probably with changes in the emission rate of fungal volatiles. Additional research on bark beetles and their symbiotic associates is necessary before the basic significance of ophiostomatoid fungal volatiles can be understood and their applied potential realized

    The interrelation between premenstrual syndrome and major depression : results from a population-based sample

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    BACKGROUND: Research about the relationship between premenstrual syndrome (PMS) and major depression is limited. This study examined the relationship between moderate to severe PMS and major depression in a population-based sample of women of reproductive age. The objectives of the study were to assess the association between premenstrual syndrome and major depression, to analyse how PMS and major depression differ and to characterise the group of women who report both PMS and major depression. METHODS: Data were obtained from the Swiss Health Survey 2007. Included in the analysis was data from women under the age of 55 without hysterectomy and who answered the questions on PMS symptoms. The population-based sample consisted of 3518 women. Weighted prevalence rates were calculated and relative risk ratios for PMS, major depression and women who reported both PMS and major depression, were calculated with logistic multinominal logit regression. RESULTS: The prevalence of major depression was 11.3% in women screening positive for moderate PMS and 24.6% in women screening positive for severe PMS. Compared to women without any of these conditions, women who reported moderate to severe alcohol consumption had a lower risk for PMS. Women reporting use of antidepressants, and use of oral contraceptives had a higher risk for major depression compared to women without any of these conditions. Women reporting work dissatisfaction had a higher risk for PMS. A higher relative risk to report both PMS and major depression compared to women without PMS or major depression was related to factors such as high psychological distress, low mastery, psychotropic drug consumption, and low self-rated health. CONCLUSIONS: The results suggested that women who suffer from both PMS and major depression are more impaired compared to women with only one disorder. The results further indicated that PMS and major depression are different disorders that can, however, co-occur
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