instruction:
Given a passage with a context and an answer, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.
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Context: Stomatal guard cells monitor and respond to environmental and endogenous signals such that the stomatal aperture is continually optimised for water use efficiency. A key signalling molecule produced in guard cells in response to plant hormones, light, carbon dioxide and pathogen-derived signals is hydrogen peroxide (H(2)O(2)). The mechanisms by which H(2)O(2) integrates multiple signals via specific signalling pathways leading to stomatal closure is not known.', 'Here, we identify a pathway by which H(2)O(2), derived from endogenous and environmental stimuli, is sensed and transduced to effect stomatal closure. Histidine kinases (HK) are part of two-component signal transduction systems that act to integrate environmental stimuli into a cellular response via a phosphotransfer relay mechanism. There is little known about the function of the HK AHK5 in Arabidopsis thaliana. Here we report that in addition to the predicted cytoplasmic localisation of this protein, AHK5 also appears to co-localise to the plasma membrane. Although AHK5 is expressed at low levels in guard cells, we identify a unique role for AHK5 in stomatal signalling. Arabidopsis mutants lacking AHK5 show reduced stomatal closure in response to H(2)O(2), which is reversed by complementation with the wild type gene. Over-expression of AHK5 results in constitutively less stomatal closure. Abiotic stimuli that generate endogenous H(2)O(2), such as darkness, nitric oxide and the phytohormone ethylene, also show reduced stomatal closure in the ahk5 mutants. However, ABA caused closure, dark adaptation induced H(2)O(2) production and H(2)O(2) induced NO synthesis in mutants. Treatment with the bacterial pathogen associated molecular pattern (PAMP) flagellin, but not elf peptide, also exhibited reduced stomatal closure and H(2)O(2) generation in ahk5 mutants.
Answer: Our findings identify an integral signalling function for AHK5 that acts to integrate multiple signals via H(2)O(2) homeostasis and is independent of ABA signalling in guard cells.
answer:
Does the histidine kinase AHK5 integrate endogenous and environmental signals in Arabidopsis guard cells?

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Context: Chronic stress is generally known to exacerbate the development of numerous neuropsychiatric diseases such as fear and anxiety disorders, which is at least partially due to the disinhibition of amygdala subsequent to the prolonged stress exposure. GABA receptor A (GABAAR) mediates the primary component of inhibition in brain and its activation produces two forms of inhibition: the phasic and tonic inhibition. While both of them are critically engaged in limiting the activity of amygdala, their roles in the amygdala disinhibition subsequent to chronic stress exposure are largely unknown.', 'We investigated the possible alterations of phasic and tonic GABAAR currents and their roles in the amygdala disinhibition subsequent to chronic stress. We found that both chronic immobilization and unpredictable stress led to long lasting loss of tonic GABAAR currents in the projection neurons of lateral amygdala. By contrast, the phasic GABAAR currents, as measured by the spontaneous inhibitory postsynaptic currents, were virtually unaltered. The loss of tonic inhibition varied with the duration of daily stress and the total days of stress exposure. It was prevented by pretreatment with metyrapone to block corticosterone synthesis or RU 38486, a glucocorticoid receptor antagonist, suggesting the critical involvement of glucocorticoid receptor activation. Moreover, chronic treatment with corticosterone mimicked the effect of chronic stress and reduced the tonic inhibition in lateral amygdala of control mice. The loss of tonic inhibition resulted in the impaired GABAergic gating on neuronal excitability in amygdala, which was prevented by metyrapone pretreatment.
Answer: Our study suggests that enduring loss of tonic but not phasic GABAAR currents critically contributes to the prolonged amygdala disinhibition subsequent to chronic stress. We propose that the preferential loss of tonic inhibition may account for the development of stress-related neuropsychiatric diseases.
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Does chronic stress impair GABAergic control of amygdala through suppressing the tonic GABAA receptor currents?

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Context: This study investigated whether off-pump coronary bypass graft operations on the beating heart under normothermic conditions reduces the systemic oxidative stress and inflammatory reaction seen in patients operated under cardiopulmonary bypass (CPB).', 'A cardiac stabilizer (Octopus Tissue Stabilizer; Medtronic Inc, Minneapolis, MN) was used to perform the coronary anastomoses on the normothermic beating heart with or without CPB. Serial blood samples were taken at various intervals. Plasma was analyzed for several oxidative stress and inflammatory markers.', 'Significant increases from prior anesthesia values of lipid hydroperoxides (190% at 4 hours), protein carbonyls (250% at 0.5 hours) and nitrotyrosine (510% at 0.5 hours) were seen in the CPB group, but they were abolished or significantly reduced in the off-pump group. Complement C3a and elastase levels were rapidly increased upon the institution of CPB, and this was followed by increases in IL-8, TNF-alpha, and sE-selectin. In contrast, the rise of these factors was blunted in patients operated without CPB.
Answer: Off-pump coronary bypass graft operation on a beating heart significantly reduces oxidative stress and suppresses the inflammatory reaction associated with the use of CPB.
answer:
Does off-pump bypass graft operation significantly reduce oxidative stress and inflammation?