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Ayami Hayashi Fuminori Sano Yasuhide Nakagami Keigo Akimoto 《Mitigation and Adaptation Strategies for Global Change》2018,23(8):1179-1205
The Paris agreement adopted at the 21st Conference of Parties of the United Nations Framework Convention on Climate Change stipulates 2 and 1.5 °C targets, but their consistency with sustainable development is poorly understood. This study focuses on water stress defined by annual water consumption-to-availability ratio (CAR) and analyzes the CAR changes for 32 global regions during this century for scenarios of the 2 and 1.5 °C targets. It also estimates contributions of major factors behind such change for addressing the adaptation planning. The results show that the CARs in many (i.e., 25) regions remain very small (less than 0.1) regardless of the future temperature level. For the other seven regions, the CARs undergo significant changes, while the changes and contributing factors to them are different by region and the future temperature level. Possible adaptation strategies are given for regions of significantly increasing CARs. For instance, in Afghanistan and Pakistan and South Africa, the CARs increase mainly due to increases in irrigation water associated with socioeconomic development (i.e., food demand growth). Decreases in water availability and increases in irrigation water due to climate change also contribute to the CAR increases after 2030. The contributions of other factors (i.e., demand changes in municipal water, water for electricity generation, other industrial water, and water for livestock) are small. In these regions, securing water resources as well as irrigation water conservation are important to avoid worsening of the CAR. Adaptation strategy recommendations for other regions are also presented. 相似文献
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In Acanthomyrmex ferox, two distinct egg-types are produced: reproductive eggs that give rise to offspring and trophic eggs that serve to distribute
nutrients. Queens lay both reproductive and trophic eggs, while major and minor workers lay only trophic eggs in the presence
of the queen. The queen lays on average 17% of the trophic eggs in a colony, while majors and minors produce 42% and 41%,
respectively. The large proportion of trophic egg production by the queen and soldiers is quite remarkable, since ant queens
are expected to focus entirely on reproduction and majors, which have a defensive function in many species, to be sterile.
Received: 25 April 2000 / Accepted in revised form: 16 June 2000 相似文献
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Workers never mate in the large majority of ants, and they have usually lost the spermatheca, an organ specialized for long-term
storage of sperm. Such ‘non-sexual’ workers are restricted to laying unfertilized eggs that give rise to males, and they cannot
compete with the queens for the production of female offspring. In sharp contrast, workers in 200–300 species from phylogenetically
basal subfamilies can reproduce sexually (‘gamergates’) because they retain a functional spermatheca like the queens. Importantly,
‘non-sexual’ workers in closely related species have a vestigial spermatheca. In this study, we compared the reservoir epithelium
of ‘sexual’ workers to that of congeneric queens and ‘non-sexual’ workers using 21 species of Amblyoponinae, Ponerinae and
Ectatomminae. We show that a pronounced thickening of the epithelium near the opening of the sperm duct is strictly associated
with sexual reproduction in both castes. This is unlike ‘non-sexual’ workers in which this epithelium is always very thin,
with few organelles; but all other structures remain intact. We discuss this evolutionary degeneration of the spermatheca
and how it relates to behavioural or physiological modifications linked to mating. Our results help understand the loss of
sexual reproduction by ant workers, a critical step in the extreme specialization of their phenotype. 相似文献
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Kondo Monami Sakamoto Yasuhide Kawabe Yoshishige Nakamura Kengo Watanabe Noriaki Komai Takeshi 《Environmental Modeling and Assessment》2022,27(2):251-273
Environmental Modeling & Assessment - This work developed a model for predicting the volatilization flux from the unsaturated soil contaminated by volatile chemical substances (VCSs) such as... 相似文献