user: In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.

Input: Consider Input: Context: Extracellular histones exert part of their prothrombotic activity through the stimulation of blood cells. Besides platelets, histones can bind to red blood cells (RBCs), which are important contributors to thrombogenesis, but little is known about the functional consequences of this interaction.', 'To evaluate the effect of histones on the procoagulant potential of human RBCs with particular regard to the expression of surface phosphatidylserine (PS).', 'PS exposure on human RBCs treated with a natural mixture of histones or recombinant individual histones was evaluated with fluorescein isothiocyanate-annexin-V binding and measured with flow cytometry. Calcium influx in RBCs loaded with the calcium-sensitive fluorophore Fluo-4\xa0AM was assessed with flow cytometry. The procoagulant potential of histone-treated RBCs was evaluated with a purified prothrombinase assay and a one-stage plasma recalcification clotting test.', 'Natural histones induced PS exposure on RBCs in a dose-dependent manner, and neutralization or cleavage of histones by heparin or activated protein\xa0C, respectively, abolished PS externalization. H4 was mainly responsible for the stimulating activity of histones, whereas the other subtypes were almost ineffective. Similarly, natural histones and H4 induced influx of calcium into RBCs, whereas the other individual histones did not. Histone-induced exposure of PS on RBCs translated into increased prothrombinase complex-mediated prothrombin activation and accelerated fibrin formation in plasma.\Question: Do histones induce phosphatidylserine exposure and a procoagulant phenotype in human red blood cells?

Output: Histones induce RBCs to express a procoagulant phenotype through the externalization of PS. This finding provides new insights into the prothrombotic activity of extracellular histones.


Input: Consider Input: Context: Accumulation in the brain of small aggregates of amyloid beta-protein 42 (Abeta42) is the major pathogenic event of Alzheimer disease (AD). In familial early-onset AD this event is likely the result of Abeta42 overproduction; in the most common sporadic late-onset form of the disease the mechanisms of Abeta42 accumulation are unknown.', 'To address this issue the authors analyzed plasma levels of Abeta42 in 88 elderly patients with amnestic mild cognitive impairment (MCI), chosen as paradigm of preclinical sporadic AD.', 'The authors found a significant increase of Abeta42 plasma levels in women with MCI, in comparison to the affected men and 72 cognitively normal age-matched subjects. The levels were independent of variables in education, apolipoprotein E genotype, cholesterol, and creatinine plasma concentrations, as well as hemoglobin content.\Question: Are plasma levels of amyloid beta-protein 42 increased in women with mild cognitive impairment?

Output: The elevation of Abeta42 plasma levels in women with MCI may represent a biologic explanation for the sex-dependent increased incidence of late-onset AD in women identified by epidemiologic studies.


Input: Consider Input: Context: Induced aboveground plant defenses against pathogens can have negative effects on belowground microbial symbionts. While a considerable number of studies have utilized chemical elicitors to experimentally induce such defenses, there is surprisingly little evidence that actual aboveground pathogens affect root-associated microbes. We report here that an aboveground fungal pathogen of common bean (Phaseolus vulgaris) induces a defense response that inhibits both the belowground formation of root nodules elicited by rhizobia and the colonization with arbuscular mycorrhizal fungi (AMF).', 'Foliage of plants inoculated with either rhizobia or AMF was treated with both live Colletotrichum gloeosporioides-a generalist hemibiotrophic plant pathogen-and C. gloeosporioides fragments. Polyphenol oxidase (PPO), chitinase and β-1,3-glucanase activity in leaves and roots, as well as the number of rhizobia nodules and the extent of AMF colonization, were measured after pathogen treatments. Both the live pathogen and pathogen fragments significantly increased PPO, chitinase and β-1,3-glucanase activity in the leaves, but only PPO activity was increased in roots. The number of rhizobia nodules and the extent of AMF colonization was significantly reduced in treatment plants when compared to controls.\Question: Does an aboveground pathogen inhibit belowground rhizobia and arbuscular mycorrhizal fungi in Phaseolus vulgaris?



assistant: Output: We demonstrate that aboveground fungal pathogens can affect belowground mutualism with two very different types of microbial symbionts-rhizobia and AMF. Our results suggest that systemically induced PPO activity is functionally involved in this above-belowground interaction. We predict that the top-down effects we show here can drastically impact plant performance in soils with limited nutrients and water; abiotic stress conditions usually mitigated by microbial belowground mutualists.