The chloroplast thylakoid membrane of green plants is organized in stacked grana membranes and unstacked stroma membranes. We investigated the structural organization of Photosystem II (PSII) in paired grana membrane fragments by transmission electron microscopy. The membrane fragments were obtained by a short treatment of thylakoid membranes with the mild detergent n-dodecyl-alpha, d-maltoside...

The carotenoid content was examined in leaf and berry tissues of grapevines (cv. Cabernet Sauvignon) grown either under ambient conditions or under a polyester film to reduce UV light by 98%. Total carotenoids in leaves were less in vines grown under the UV screen. Levels of beta-carotene decreased with berry development around veraison. This effect was more pronounced in vines grown under redu...

Of the commonly accepted tools for assessing habitual dietary intake in epidemiological studies, the one that is most often used in population surveys is the food frequency questionnaire (FFQ) (Briefel et al., 1992; Kushi, 1994). When using the FFQ, the results generally represent usual intakes over an extended period and are easier to collect and process. The FFQ is then used to study associat...

We present results of mid-infrared λ = 5.0 − 16.5 µm spectrophotometric imaging of the starburst galaxies M 82, NGC 253, and NGC 1808 from the ISOCAM instrument on board the Infrared Space Observatory. The mid-infrared spectra of the three galaxies are very similar in terms of features present. The λ > ∼ 11 µm continuum attributed to very small dust grains (VSGs) exhibits a large spread in inte...

A single item is sold to two bidders by way of a sealed bid second price auction in which bids are restricted to a set of discrete values. Restricting attention to symmetric pure strategy behavior on the part of bidders, a unique equilibrium exists. When following these equilibrium strategies bidders may bid strictly above or below their valuation, implying that the item may be awarded to a bid...

the best diet for a healthy life. One characteristic these examples all share is that they fade quickly, only to be replaced by a new ultimate answer. Sometimes rather than fading, the thrilling discovery has a second life in checkout-line tabloids. A few of these items are hoaxes, some are merely consequences of over-enthusiasm about preliminary results, but many are honest mistakes carried to...

NGC 253 is a nearby spiral galaxy that is currently undergoing a nuclear burst of star formation in a 100 pc diameter region. We present spatially resolved 8–13 μm lowresolution spectra at four positions along the ridge of 8–13 μm emission. We find that the relative strengths of the ionic, dust emission features, and dust continuum emission vary with position in the galaxy but can be accounted ...

The two nearby starburst galaxies M82 and NGC 253 were observed for ∼ 100 ksec over a 10-month period in 1997. An increase of the M82 flux by a factor ∼ 2 was measured during the period July-November, when compared with the flux measured earlier in 1997. The flux measured in the field centered on M82 includes ∼ 38% of the emission from the Seyfert 1 galaxy M81. The best-fitting model for the ea...