Structural constraints on process explanations in cognitive aging.

Much of the current research in the area of cognitive aging has been focused on investigating specific processes presumed to be responsible for the age differences observed in particular cognitive tasks. A central thesis of this article is that age-related effects on cognitive variables seldom occur in isolation, and hence, they are best interpreted in the context of the structural interrelations that exist among variables and the relations of age on that organizational structure. Results from analyses of 2 separate data sets suggest that large proportions of the age-related effects across a wide range of cognitive variables are shared and that independent, or unique, age-related effects often contribute relatively little to the age differences observed in many cognitive variables. These findings imply that it is important to consider the structure within which a variable occurs when attempting to investigate the processes responsible for age-related differences on that variable. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Kritische Untersuchungen über Bildung und Entwicklung der Triticeen-Stärkekörner

Critical Examination of the Development of Triticeae Starch Grains. At the right time when the first antheres appear at the top of the ears large quantities of point-shaped starch grains are to be seen in the young ovary. From there the diameters of the small starch grains have been measured until milky maturity. In this way the identity and the growing of the small starch grains had been confirmed. After some days when diameters of the small starch grains reach 4–6 üm a second step of development begins. The starch grains are progressively surrounded in the equatorial planes by a consurrounded continually enlarging structure which resembles two lips with a furrow between them. When the two lips surround the „nucleus”︁ thickness and diameters of the granule continue to increase in such a way that the furrow becomes shallower and is present in the mature beconvex structure only as a shallow score.     

Proficiency testing for chemical analytical laboratories--general principles concerning organization and assessment of results

This brief overview outlines recent progress in our understanding of the regulation of cell population size, focusing on some important developments in cell cycle control and the recognition of the importance of growth arrest and cell death. Histopathologists, and others with an interest in tissue architecture, have much to offer to those who study the biochemical and molecular processes of proliferation, growth arrest and cell death, and these processes are unlikely to be understood simply by analysis of in vitro systems and cell lines. Such biochemical and histological information may well feed back into clinical medicine in terms of new approaches and techniques, new reagents and new paradigms. With regard to the application of measures of proliferation, growth arrest and cell death as prognostic factors or other diagnostic tools, we are sceptical. Methods for assessing cell proliferation seem unlikely to be implemented widely in practice since there is little direct evidence that they are really an improvement on conventional histological assessment, optimally employed. But, there again, we may be proved wrong! In particular, it may be that, if carefully employed, assays that integrate information about death, growth arrest and proliferation may be clinically valuable.     

Antinuclear antibodies and patterns of nuclear immunofluorescence in type 1 autoimmune hepatitis

To determine the significance of antinuclear antibodies and their patterns of indirect immunofluorescence in type 1 autoimmune hepatitis, sera from 99 patients were evaluated. Patients with antinuclear antibodies had a lower frequency of liver transplantation (6% vs 22%, P = 0.04) than seronegative patients. They were also more commonly HLA-DR4-positive than seronegative patients (56% vs 30%, P = 0.05) and normal subjects (56% vs 30%, P = 0.004). The 42 patients with antinuclear antibodies and a diffuse pattern of indirect immunofluorescence had higher serum titers of ANA (serum titers > or = 1:500, 71% vs 14%, P < 0.0001) and SMA (serum titers > or = 1:500, 69% vs 27%, P = 0.003) than the 22 patients with antinuclear antibodies and a speckled pattern. These patients, however, were otherwise not distinguished by clinical features and treatment response. Patients with a speckled pattern had A1-B8-DR3 more frequently than patients with a diffuse pattern (65% vs 23%, P = 0.005) and normal subjects (65% vs 13%, P < 0.0001), but they had no other salient features. We conclude that patients with antinuclear antibodies have a better long-term prognosis than seronegative patients, and they have HLA-DR4 more commonly. The patterns of indirect immunofluorescence associated with ANA positivity have no practical clinical implications.     

Applications of Judd–Ofelt theory to praseodymium and samarium ions in phosphate glass

The Judd–Ofelt (J–O) theory has had a remarkable success in the characterization of radiative transitions in lanthanide doped solids. The purpose of this paper is to review the applications of the J–O theory to the Pr³⁺ and Sm³⁺ ions and to use this system as an occasion to appraise its validity and to clarify its limits. In this paper we dwell at length on the absorption and luminescence measurements of two glass samples doped with Pr³⁺ and Sm³⁺, because they are basic for the J–O treatment. The results obtained for the J–O theory application to phosphate glasses doped with Pr³⁺ and Sm³⁺ present two undesirable outcomes: (1) a positive value of parameter Ω₂ and (2) large uncertainties with which the three Judd–Ofelt parameters were obtained. The validity of the J–O theory for intensity analysis was also tested for Sm³⁺ doped in phosphate glass. The resulting Ω₂ was much lower than Ω₄. The first set parameters were obtained using all the levels for which f_exp. was available. The second set parameter values were evaluated without the ⁶F_1/2 and ⁶H_15/2 levels. The Ω_2,4,6 values given in these two sets clearly suggest that particular care should be taken while evaluating the Judd–Ofelt parameters as well as when these parameters are compared to other systems due to their strong dependence on the nature of levels.     

Mikroskopische Untersuchung von Tomatenmark

Zusammenfassung 3 fach konzentriertes Tomatenmark in Tuben zeigt bei der mikroskopischen Untersuchung infolge weitgehenden Aufschlusses and guter Passierung nicht die zu erwartenden Gewebselemente der Frucht, sondern Cellulosefibrillen der Zellwände der Parenchymzellen des Fruchtmarkes in Bändern and Bündeln. Diese lassen zwischen gekreuzten Polarisatoren kurz vor dem Auslöschen in den Orthogonallagen grobe dunkle Querstreifen infolge von periodischen Knickungen erkennen. Vereinzelte Reste von Spiralgefäßen, zahllose winzige Oxalatkriställchen and rote Chromoplastenreste sind außerdem vorhanden.