1,721,185 research outputs found
Investigation on Photosystem II functional antenna size and excitonic connectivity in Selaginella martensii.
No full textEhrhart polynomials of rank two matroids
Full text linkOver a decade ago De Loera, Haws and Köppe conjectured that Ehrhart polynomials of matroid polytopes have only positive coefficients and that the coefficients of the corresponding h⁎-polynomials form a unimodal sequence. The first of these intensively studied conjectures has recently been disproved by the first author who gave counterexamples in all ranks greater than or equal to three. In this article we complete the picture by showing that Ehrhart polynomials of matroids of lower rank have indeed only positive coefficients. Moreover, we show that they are coefficient-wise bounded by the Ehrhart polynomials of minimal and uniform matroids. We furthermore address the second conjecture by proving that h⁎-polynomials of matroid polytopes of sparse paving matroids of rank two are real-rooted and therefore have log-concave and unimodal coefficients. In particular, this shows that the h⁎-polynomial of the second hypersimplex is real-rooted, thereby strengthening a result of De Loera, Haws and Köppe
La diagnosi di laboratorio delle infezioni da virus herpes simplex, varicella/zoster e citomegalico
No full textI disturbi dell’elaborazione pragmatica
No full textIl lavoro è dedicato ad una discussione dei disturbi dell'elaborazione pragmatica, delle possibili sedi neurali coinvolte e della valutazione e riabilitazione di questi disturbi
Embryo tranfer nella specie bovina: trattamento superovulatorio con P.M.S.G. e siero anti P.M.S.G.
No full textThe Soil–Plant Continuity of Rare Earth Elements: Insights into an Enigmatic Class of Xenobiotics and Their Interactions with Plant Structures and Processes
No full textRare earth elements (REEs) are increasingly present in the environment owing to their extensive use in modern industries, yet their interactions with plants remain poorly understood. This review explores the soil–plant continuum of REEs, focusing on their geochemical behavior in soil, the mechanisms of plant uptake, and fractionation processes. While REEs are not essential for plant metabolism, they interact with plant structures and interfere with the normal functioning of biological macromolecules. Accordingly, the influence of REEs on the fundamental physiological functions of plants is reviewed, including calcium-mediated signalling and plant morphogenesis. Special attention is paid to the interaction of REEs with photosynthetic machinery and, particularly, the thylakoid membrane. By examining both the beneficial effects at low concentrations and toxicity at higher levels, this review provides some mechanistic insights into the hormetic action of REEs. It is recommended that future research should address knowledge gaps related to the bioavailability of REEs to plants, as well as the short- and long-range transport mechanisms responsible for REE fractionation. A better understanding of REE–plant interactions will be critical in regard to assessing their ecological impact and the potential risks in terms of agricultural and natural ecosystems, to ensure that the benefits of using REEs are not at the expense of environmental integrity or human health
“The Tremendous Power of the Negative”: A Note on Aristotle<i>Sophistical Refutations</i>165B17
No full textPhotosynthesis under Environmental Fluctuations: A Challenge for Plants, a Challenge for Researchers
No full textThe ability of plants to cope successfully with environmental fluctuations is a result of their evolution in subaerial environments, where fluctuations in parameters such as temperature, light, and water availability, are the norm and stable states are the exception [...
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