Angiosperm leaf fossils (16.7-25 x 10(6) years by potassium/argon dating) referable to Zelkova were isolated from pyroclastic deposits in the Succor Creek Formation, Oregon. These fossils reveal a three-dimensional structure in mesophyll cell layers and vascular bundles, while transmission electron microscopy of fixed tissues reveals well-preserved chloroplasts with grana stacks and starch, as ...

Freezing, dehydration, and supercooling cause microtubules in mesophyll cells of spinach (Spinacia oleracea L. cv Bloomsdale) to depolymerize (ME Bartolo, JV Carter [1991] Plant Physiol 97: 175-181). The objective of this study was to gain insight into the question of whether microtubules depolymerize as a direct response to environmental stresses or as an indirect response to cellular changes ...

Background and Aims Nebbiolo grapes are used to produce Sfursat wine, following partial dehydration. This research aimed clarify the influence of fruit exposure light postharvest water loss on concentration green leaf volatiles (GLVs) lipoxygenase (LOX) alcohol dehydrogenase (ADH) activity grapes. Methods Results from Control vines (no defoliation) (ND) defoliated at fruitset (DFS) or post-vera...

In this paper, we propose a novel heuristic algorithm for the volumetric-modulated arc therapy treatment planning problem, optimizing the trade-off between delivery time and treatment quality. We present a new mixed integer programming model in which the multi-leaf collimator leaf positions, gantry speed, and dose rate are determined simultaneously. Our heuristic is based on column generation; ...

conclusions it is reasonable to evaluate blood urea nitrogen, potassium, and hemoglobin of children with gastroenteritis. moreover, conducting white blood cell, stool exam, and urine analysis is recommended for those with febrile gastroenteritis, especially in girls younger than two years of age. overall, conducting all the mentioned tests for these patients is not necessary as a routine, and d...

OBJECTIVE The fluid recommendation for adults aged 70+ years has been criticised on the basis of a low prevalence of dehydration in community-dwelling older adults. This study explores whether the low prevalence might reflect limitations of individual dehydration indices. DESIGN Cross-sectional data on plasma sodium, blood urea nitrogen (BUN), creatinine, glucose and potassium were used to cl...

We have an Electronic Field Guide which contains an image database with thousands of leaf images. We have a system which can take a photo of a leaf and use this image to query the database and bring out a set of leaf images which have the most similar shape as the query leaves from different species. The existing query algorithm is based on a brute force approach, and it does not have a very at...

Voltage-elicited action potentials (APs) have been reproducibly obtained in Arabidopsis thaliana ecotype col. Excitations pulses (voltage-duration: V-t) were given in the 0- to 18-V and 0- to 35-s ranges, respectively, by two galvanically isolated Pt/Ir small wires inserted trough the main vein in the distal part of the leaf. Conventional liquid junction Ag/AgCl electrodes were placed at the zo...

Limited information is available regarding the effects of mild dehydration on cognitive function. Therefore, mild dehydration was produced by intermittent moderate exercise without hyperthermia and its effects on cognitive function of women were investigated. Twenty-five females (age 23.0 ± 0.6 y) participated in three 8-h, placebo-controlled experiments involving a different hydration state ea...