An optically activated cantilever using photomechanical effects in dye-doped polymer fibers

We report on what we believe is the first demonstration of an optically activated cantilever due to photomechanical effects in a dye-doped polymer optical fiber. The fiber is observed to bend when light is launched off-axis. The displacement angle monotonically increases as a function of the distance between the illumination point and the fiber axis, and is consistent with differential light-induced length changes. The photothermal and photo-reorientation mechanisms, each with its own distinct response time, are proposed to explain the observed time dependence. The measured degree of bending is consistent with a model that we have proposed which includes coupling between photoisomerization and heating. Most importantly, we have discovered that at high light intensity, a cooperative release of stress results in cis-to-trans isomerization that yields a large and abrupt length change.Comment: 13 pages, 16 figure

Pets as Sentinels of Human Exposure to Neurotoxic Metals

The idea that animals may be used as sentinels of environmental hazards pending over humans and the associated public health implications is not a new one. Nowadays pets are being used as bioindicators for the effects of environmental contaminants in human populations. This is of paramount importance due to the large increase in the worldwide distribution of synthetic chemicals, particularly in the built environment. Companion animals share the habitat with humans being simultaneously exposed to and suffering the same disease spectrum as their masters. Moreover, their shorter latency periods (due to briefer lifespans) enable them to act as early warning systems, allowing timely public health interventions. The rise on ethical constraints on the use of animals and, consequently, on the sampling they can be subjected to has led to the preferential use of noninvasive matrices, and in this case we are looking into hair. This chapter focuses in three non-essential metals: mercury, lead, and cadmium, due to their ubiquitous presence in the built environment and their ability of affecting the mammal nervous system. There is a fairly short amount of studies reporting the concentrations of these metals in pets’ hair, particularly for cats. These studies are characterized, and the metal concentrations corresponding to different parameters (e.g., age, sex, diet, rearing) are described in order to provide the reader with a general vision on the use of this noninvasive matrix on the studies conducted since the last two decades of the twentieth century.publishe

Der rupsen begin, voedzel en wonderbaare verandering : waar in de oorspronk, spys en gestaltverwisseling : als ook de tyd, plaats en eigenschappen der rupsen, wormen, kapellen, uiltjes, vliegen, en andere diergelyke bloedelooze beesjes vertoond word : ten dienst van alle liefhebbers der insecten, kruiden, bloemen en gewassen : ook schilders, borduurders &c. : naauwkeurig onderzogt, na \u27t leven geschildert, in print gebragt, eu in \u27t kort beschreven /

Pagination: v. 1: 30 p., [51] leaves of plates; v. 2: [4], 30 p., [51] leaves of plates; v. 3: 24 p., [51] p. of plates.Signatures: v. 1: A-C⁴ D⁴(-D4); v. 2: *² A-C⁴ D⁴(-D4); v. 3: A-C⁴.Publication dates from Nissen."Derde en laaste deel der Rupsen begin, voedzel en wonderbaare verandering ... door Maria Sibilla Merian, saalr. In print gebracht en in't licht gegeven door haar jongste dochter Dorothea Maria Henricie. Amsterdam, Gedruckt voor de uytgeefster ... als mede alle de andere werken en nagelaatene schilderkonst, van bovengemelde haare Moeder saalr."--T.p., v. 3.Added engraved frontispiece to each volume.Nissen, C. Botanische Buchillustration (2. Aufl.),Mode of access: Internet.Binding: contemporary sprinkled calf; boards, edges of boards and spine gilt tooled; marbled edges.Vol. 3 is a gift of Tania Norris. Includes additional handcolored print, a variariant of pl. [26] in v. 3