Meniscus-climbing insects

Water-walking insects and spiders rely on surface tension for static weight support and use a variety of means to propel themselves along the surface. To pass from the water surface to land, they must contend with the slippery slopes of the menisci that border the water's edge. The ability to climb menisci is a skill exploited by water-walking insects as they seek land in order to lay eggs or avoid predators; moreover, it was a necessary adaptation for their ancestors as they evolved from terrestrials to live exclusively on the water surface. Many millimetre-scale water-walking insects are unable to climb menisci using their traditional means of propulsion. Through a combined experimental and theoretical study, here we investigate the meniscus-climbing technique that such insects use. By assuming a fixed body posture, they deform the water surface in order to generate capillary forces: they thus propel themselves laterally without moving their appendages. We develop a theoretical model for this novel mode of propulsion and use it to rationalize the climbers' characteristic body postures and predict climbing trajectories consistent with those reported here and elsewhere.     

Rossby waves on the Sun as revealed by solar 'hills'

It is a long-standing puzzle that the Sun's photosphere--its visible surface--rotates differentially, with the equatorial regions rotating faster than the poles. It has been suggested that waves analogous to terrestrial Rossby waves, and known as r-mode oscillations, could explain the Sun's differential rotation: Rossby waves are seen in the oceans as large-scale (hundreds of kilometres) variations of sea-surface height (5-cm-high waves), which propagate slowly either east or west (they could take tens of years to cross the Pacific Ocean). Calculations show that the solar r-mode oscillations have properties that should be strongly constrained by differential rotation. Here we report the detection of 100-m-high 'hills' in the photosphere, spaced uniformly over the Sun's surface with a spacing of (8.7 +/- 0.6) x 10(4) km. If convection under the photosphere is organized by the r-modes, the observed corrugated photosphere is a probable surface manifestation of these solar oscillations.     

Use of the exo-β-(1→3) glucanase from basidiomycete QM 806 in studies on yeast

Résumé L'exo--(13) glucanasem isolée duBasidiomycete QM 806 a été utilisée avec succès pour l'analyse des polysaccharides de la paroi cellulaire de la levureSaccharomyces cerevisiae et pour la formation de protoplastes à partir deSaccharomyces cerevisiae etWickerhamia fluorescens.

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Acknowledgments. We are indepted to MissE. Sigarlakie and MissE. Wespi for technical assistance during the course of this investigation.     

The 11-oxygen function in steroid metabolism

Zusammenfassung Es wird versucht, die möglichen Zusammenhänge zwischen den physiko-chemischen Eigenschaften der C₁₁-Gruppe, dem Stoffwechsel und der biologischen Wirkung der 11-Oxysteroide aufzuzeigen. Die Bedeutung der reversiblen Oxydationreduktion dieser Gruppe wird besonders hervorgehoben.

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Dedicated to ProfessorF. Verzár, for his 70th birthday on September 18, 1956.     

Characterization of the role of metallothionein-3 in an animal model of Alzheimer’s disease

Among the dementias, Alzheimer’s disease (AD) is the most commonly diagnosed, but there are still no effective drugs available for its treatment. It has been suggested that metallothionein-3 (MT-3) could be somehow involved in the etiology of AD, and in fact very promising results have been found in in vitro studies, but the role of MT-3 in vivo needs further analysis. In this study, we analyzed the role of MT-3 in a mouse model of AD, Tg2576 mice, which overexpress human Amyloid Precursor Protein (hAPP) with the Swedish mutation. MT-3 deficiency partially rescued the APP-induced mortality of females, and mildly affected APP-induced changes in behavior assessed in the hole-board and plus-maze tests in a gender-dependent manner. Amyloid plaque burden and/or hAPP expression were decreased in the cortex and hippocampus of MT-3-deficient females. Interestingly, exogenously administered Zn₇MT-3 increased soluble Aβ40 and Aβ42 and amyloid plaques and gliosis, particularly in the cortex, and changed several behavioral traits (increased deambulation and exploration and decreased anxiety). These results highlight that the control of the endogenous production and/or action of MT-3 could represent a powerful therapeutic target in AD.     

和谐就是力量--兼评培根的"知识就是力量"

和谐--无论是结构状态的分布有序还是功能状态的进化有道,都蕴涵着无与伦比的力量与神奇.自我和谐是个人身心微观和谐发展的调适力,人我和谐是社会中观和谐发展的协和力,物我和谐是人与自然宏观和谐发展的自然力,以至在某种意义上我们不得不说,和谐是发展之源,和谐就是力量;反之,自我失衡是身心微观灾变之端,人我失衡是社会中观模糊或畸形运作之始,物我失衡是一场没有胜利的逆变,以至在某种意义上我们不得不说,失衡是畸变之兆,失衡就是耗散."知识就是力量"是一个工具理性张扬的命题,而"和谐就是力量"则是"知识就是力量"的合理升华,是东方智慧的集大成.通过物理学与伦理学的二维证明我们发现,"和谐就是力量"不仅是一个长期被忽视的物理学定律,而且是一个重要的和谐伦理命题.