Aspects of plant behaviour under anoxia and post-anoxia

All plants are able to survive anoxic periods, but the degree of tolerance shows large variation. The main injuries related to anoxia are eventually due to changes in energy metabolism. Low energy charge values indicate a cessation of many ATP consuming processes. Sugar starvation, lactic acid fermentation and proton release from leaky vacuoles are responsible for cell death. Long-term anoxia tolerance is dependent on storage products in the vicinity of sinks, on an adequate control of glycolysis, synthesis of essential proteins, and stability of membranes and organelles. However, no fundamental differences between the metabolic pathways of tolerant and non-tolerant tissues are known. It is rather a question of minor changes and the regulation of anaerobic metabolism. Re-exposure of anoxic tissues to air may even be more detrimental than anoxia itself. These injuries are mainly due to enhanced radical generation. Lipid peroxidation processes lead to membrane damage, disintegration, and leakage of solutes. Under natural conditions plants are equipped with radical-detoxifying systems (SOD, peroxidases and antioxidants). Natural detoxifying systems can be reduced in non-adapted plants under anoxia and they become more sensitive to post-anoxic damage. In addition, the rapid conversion of ethanol to extremely toxic acetaldehyde seems to be a cause of tissue injury and deat

Fermentation Rates and Ethanol Accumulation in Relation to Flooding Tolerance in Rhizomes of Monocotyledonous Species

Under anoxia an accumulation of ethanol took place in all species. Lactic fermentation was found to be of less importance in every case. The amount of ethanol accumulated depended on the ability of the rhizome to eliminate it from its tissues. Despite great variations in fermentative capacity as seen in the ADH measurements the wetland species did not accumulate ethanol to concentrations greater than 30 μmol g−1 fresh weight. This represented a plateau above which the ethanol concentration did not rise even with continued anaerobic incubation. No such plateau of ethanol accumulation was found in the dryland species Iris germanica which accumulated ethanol steadily reaching concentrations of 70 μmol g−1 fresh weight. If ethanol is toxic to higher plant tissues then the steady state condition of low ethanol accumulation found in wetland species will minimize this dange

Extensive spherical amyloid deposition presenting as a pituitary tumor

A 71-yr-old man was admitted for further evaluation and trans-sphenoidal surgery of a pituitary tumor. He complained of impotence and decreased libido over a period of about 40 yr. Thirty-eight yr ago he was treated for bilateral gynecomastia with galactorrhea. Endocrinological investigation at presentation revealed only mild hyperprolactinemia and hypogonadotropic hypogonadism. Pituitary magnetic resonance imaging (MRI) showed a tumor up to 2.5 cm in diameter with infiltration of the sphenoid sinus and right cavernous sinus. The tumor exhibited a heterogeneous hyperintense signal on T1-weighted images and hypointense signal on T2-weighted images. Standard trans-sphenoidal surgery was performed and a brownish mass was found inside the sella, which was removed. Histological examination of the mass revealed extensive spherical amyloid deposits with strongly positive immunohistochemical staining for prolactin. Therefore, a prolactinoma with extensive spherical amyloid deposition was diagnosed. Extensive spherical amyloid deposition is a rare finding in prolactin-secreting pituitary adenomas. So far, characteristic radiological findings by MRI have been described only twice. Due to characteristic MRI findings, the diagnosis of extensive intrasellar amyloid deposition can be entertained pre-operatively. Trans-sphenoidal surgical resection is essential to confirm the diagnosis histologically and because of the potential lack of tumor shrinkage under dopaminagonist therapy in this type of prolactinom

Five-Branes in Heterotic Brane-World Theories

The effective action for five-dimensional heterotic M-theory in the presence of five-branes is systematically derived from Horava-Witten theory coupled to an M5-brane world-volume theory. This leads to a five-dimensional N=1 gauged supergravity theory on S^1/Z_2 coupled to four-dimensional N=1 theories residing on the two orbifold fixed planes and an additional bulk three-brane. We analyse the properties of this action, particularly the four-dimensional effective theory associated with the domain-wall vacuum state. The moduli Kahler potential and the gauge-kinetic functions are determined along with the explicit relations between four-dimensional superfields and five-dimensional component fields.Comment: 19 pages, Latex, typos corrected, reference adde

Trait Aggressiveness Predicting Aggressive Behavior: The Moderating Role of Meta-Cognitive Certainty.

Research on aggression has benefitted from using individual-difference measures to predict aggressive behavior. Research on meta-cognition has recently identified that the predictive utility of individual-difference inventories can be improved by considering the certainty with which people hold their self-views. Merging these two frameworks, the present research examines whether assessing certainty in trait aggressiveness improves its ability to predict aggressive outcomes. Across two studies, participants reported their level of trait physical aggressiveness and the certainty with which they held their responses to the scale (predictor variables). Aggressive behavioral intentions (Study 1 and 2) and actual aggressive behavior (Study 2) were used as dependent measures. As hypothesized, results indicated that certainty moderated the effects of individual-differences in aggressiveness on both aggressive outcomes. Therefore, considering the certainty with which people hold their relevant traits can be useful for understanding aggression, and also for predicting the consistency between personality and behavior.pre-print741 K

Stability Walls in Heterotic Theories

We study the sub-structure of the heterotic Kahler moduli space due to the presence of non-Abelian internal gauge fields from the perspective of the four-dimensional effective theory. Internal gauge fields can be supersymmetric in some regions of the Kahler moduli space but break supersymmetry in others. In the context of the four-dimensional theory, we investigate what happens when the Kahler moduli are changed from the supersymmetric to the non-supersymmetric region. Our results provide a low-energy description of supersymmetry breaking by internal gauge fields as well as a physical picture for the mathematical notion of bundle stability. Specifically, we find that at the transition between the two regions an additional anomalous U(1) symmetry appears under which some of the states in the low-energy theory acquire charges. We compute the associated D-term contribution to the four-dimensional potential which contains a Kahler-moduli dependent Fayet-Iliopoulos term and contributions from the charged states. We show that this D-term correctly reproduces the expected physics. Several mathematical conclusions concerning vector bundle stability are drawn from our arguments. We also discuss possible physical applications of our results to heterotic model building and moduli stabilization.Comment: 37 pages, 4 figure

Extensive spherical amyloid deposition presenting as a pituitary tumor

A 71-yr-old man was admitted for further evaluation and trans-sphenoidal surgery of a pituitary tumor. He complained of impotence and decreased libido over a period of about 40 yr. Thirty-eight yr ago he was treated for bilateral gynecomastia with galactorrhea. Endocrinological investigation at presentation revealed only mild hyperprolactinemia and hypogonadotropic hypogonadism. Pituitary magnetic resonance imaging (MRI) showed a tumor up to 2.5 cm in diameter with infiltration of the sphenoid sinus and right cavernous sinus. The tumor exhibited a heterogeneous hyperintense signal on T1-weighted images and hypointense signal on T2-weighted images. Standard trans-sphenoidal surgery was performed and a brownish mass was found inside the sella, which was removed. Histological examination of the mass revealed extensive spherical amyloid deposits with strongly positive immunohistochemical staining for prolactin. Therefore, a prolactinoma with extensive spherical amyloid deposition was diagnosed. Extensive spherical amyloid deposition is a rare finding in prolactin-secreting pituitary adenomas. So far, characteristic radiological findings by MRI have been described only twice. Due to characteristic MRI findings, the diagnosis of extensive intrasellar amyloid deposition can be entertained pre-operatively. Trans-sphenoidal surgical resection is essential to confirm the diagnosis histologically and because of the potential lack of tumor shrinkage under dopaminagonist therapy in this type of prolactinom

The view of young Spaniards towards online activism: advantages, scepticism and supported causes

© 2022 The authors. This document is made available under the CC-BY-NC-SA 4.0 license http://creativecommons.org/licenses/by-nc-sa/4.0/ This document is the Accepted version of a Published Work that appeared in final form in EMPIRIA. Revista de Metodología de Ciencias Sociales. To access the final edited and published work see DOI/ Empiria.56.2022.34440Los nuevos procesos de comunicación pública entre los jóvenes han facilitado una nueva forma de entender la participación ciudadana colectiva: la llamada e- participación. No se ha publicado e investigado lo suficiente sobre este fenómeno que supone una nueva perspectiva de entender estos procesos sociales. Este estudio muestra opiniones de los jóvenes sobre la participación online y aporta las posibles ventajas e inconvenientes de esta vía de participación, así como se señalan las principales causas apoyadas y las plataformas más conocidas y utilizadas. Se analiza hasta qué punto el activismo online de los jóvenes es un activismo proactivo o no. Se trata de un trabajo exploratorio que apunta nuevas vías de investigación sobre una tendencia comunicativa y participativa que en el actual contexto de comunicación global se verá potenciada y justificada en años venideros. Se utilizan datos primarios en metodología mixta. Se recogen datos mediante una encuesta original (N=463) y se emplean grupos de discusión, buscando una triangulación metodológica en jóvenes entre 18 y 22 años. Los resultados muestran cómo el activismo online está arraigado entre los jóvenes estudiados y que lo ven como una forma complementaria a las vías tradicionales, y no como una alternativa. Además, destacan sobre todo el seguimiento decausas sociopolíticas y medioambientales como los grandes ejes en este tipo de e-participación frente a causas de carácter más tradicional.New public communication processes among young people have facilitated a new way of understanding collective citizen participation: the so-called e-participation. Not much has been published and researched on this phenomenon, which represents a new perspective for understanding these social processes. This study aims to present the general opinion of this phenomenon among young Spaniards and to provide the possible advantages and disadvantages of this new form of participation, as well as to point out the main causes supported and the most widely known and used platforms. Finally, the aim is to analyse to what extent young people's online activism is a proactive activism or not. It is an exploratory study that opens up new avenues of research into a communicative and participatory trend that, in the current context of global communication, will be strengthened and justified in the years to come. Primary data are used in a mixed methodology, using an original survey (N=463) and qualitative methodology based on discussion groups, seeking a methodological triangulation in youth people (18 to 22 years). The results show how this phenomenon is deeply rooted among young Spaniards, who see it as a complementary form of traditional methods, and not as a substitute. Moreover, they highlight above all the monitoring of socio-political and environmental causes as the main axes in this type of e-participation as opposed to more traditiona