14 research outputs found

    The Late 1970's Bubble in Dutch Collectible Postage Stamps

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    Collectible postage stamp prices in the Netherlands witnessed a bubble in the late 1970’s, while prices rapidly floored in the mid 1980’s. We analyze 500 individual stamps prices (instead of a single index) to examine if the bubble could somehow have been predicted and whether there were early warning signals. Also, we study whether the characteristics of these stamps mediated the bubble and the price landing afterwards. Scarcity and initial price levels seem to have predictive value in various dimensions. Implications for recognizing bubbles in other asset prices are discussed

    Microautoradiographic Technique and Distribution of Radioactive Calcium by the Peanut Fruit

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    Peanut plants of the Virginia Runner Variety (Chiba 74) were grown in sand culture with the root and fruit zones isolated from each other as shown in Fig. 1. The top of each pot, which held the root of the plant, was placed 1 inch above the surface of the sand in the fruiting glass jug. When the gynophore reached the surface of the jug, (Ca)^-(Cl)_2 was added, at the rate of 10μc, to each jug containing250 gr. of sand. As regards the technique for microautoradiograph, the stripping emulsion method was tried by using fuji autoradiographic plate ET-2E in a dark room. And the slides were exposed to β-ray of (Ca)^ from 8 to 128 days in the light tight box. The best exposure time was about 2 months in the case of histological section of 25μ. And it was important to avoid overexposure, since this caused a loss of resolution as shown in Fig. 2 (a-d). The relationship between the deposition of (Ca)^ in peanut and the anatomical structure was presented in Fig. 2 (e-i). In the autoradiogram of the longitudinal sections of 10,30-day-old fruit, it was noted that the extent and nature of the (Ca)^ deposition was characteristic and was a reflection of the particular fruit structure, as follows; A, the (Ca)^-containing compounds were relatively concentrated in the cortex of the gynophore, especially in the single layer of endodermis. B, within the pod, they were found to be in the quantities in the tracheid and epidermis parts of the shell, while in the seed or seed coat scarcely any (Ca)^ was found. It seemed that from the basal region of shell a considerable amount of (Ca)^ entered the terminal one during the development of the fruit

    Guidelines for the use and interpretation of assays for monitoring autophagy

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    In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field

    Guidelines for the use and interpretation of assays for monitoring autophagy

    No full text
    In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field

    Guidelines for the use and interpretation of assays for monitoring autophagy

    No full text

    Guidelines for the use and interpretation of assays for monitoring autophagy

    No full text
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