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Drought compromises plants ability to replace transpired water vapor with water absorbed from the soil, leading to extensive xylem dysfunction and causing plant desiccation and death. Short-term plant responses to drought rely on stomatal closure, and on the plants ability to recover hydraulic functioning after drought relief. We hypothesize a key role for abscisic acid (ABA) not only in the control of stomatal aperture, but also in hydraulic recovery. SANT1 Young plants of Populus nigra L. were used to investigate possible relationships among abscisic acid (ABA), non-structural carbohydrates (NSC) and xylem hydraulic function under drought and after re-watering. In Populus nigra L. plants subjected to drought, water transport efficiency and hydraulic recovery after re-watering were monitored by measuring the percentage loss of hydraulic conductivity (PLC) and stem specific hydraulic conductivity (Kstem). In the same plants ABA and NSC were quantified in wood and bark. Drought severely reduced stomatal conductance (gL) and markedly increased the PLC. Leaf and stem water potential, and stem hydraulic efficiency fully recovered within 24 hours after re-watering, but gL values remained low. After re-watering, we found significant correlations between changes in ABA content and hexoses concentration both in wood and bark. Our findings suggest a role for ABA in the regulation of stem carbohydrate metabolism and starch mobilization upon drought relief, possibly promoting the restoration of xylem transport capacity. © The Author(s) 2020. Published by Oxford University Press. All rights reserved. For permissions, please e-mail journals.permission@oup.com.- Gas inside wood plays an important role in plant functioning, but there has been no study examining the adaptive nature of gas inside wood across plants differing in biomechanical demands. © The Author(s) 2020. Published by Oxford University Press. All rights reserved. For permissions, please e-mail journals.permission@oup.com.OBJECTIVE Air pollution had been reported to be associated with the reproductive health of women. However, the association of particulate matter (PM) and acid gases air pollution with premenstrual syndrome (PMS) warrants investigation. This study investigated the effects of air pollution on PMS risk. POPULATION We combined data from the Taiwan Air Quality-Monitoring Database (TAQMD) and the Longitudinal Health Insurance Database. In total, an observational cohort of 85078 Taiwanese women not diagnosed as having PMS. METHODS Air pollutant concentrations were grouped into four levels based on the concentration quartiles of several types of air pollutants.Main Outcome Measures We then applied univariable and multivariable Cox proportional hazard regression models to assess PMS risk in association with each pollutant type. RESULTS Women exposed to Q4-level SO2 exhibited a 7.77 times higher PMS risk compared with those to Q1-level SO2 (95% confidence interval [CI] = 6.22-9.71). Women exposed to Q4-level NOx exhibited a 2.86 times higher PMS risk compared with those exposed to Q1-level NOx (95% CI = 2.39-3.43). Women exposed to Q4-level NO exhibited a 3.17 times higher PMS risk compared with women exposed to Q1-level NO (95% CI = 2.68-3.75). Finally, women exposed to Q4-level PM with a ≤ 2.5-µm diameter (PM2.5) exhibited a 3.41 times higher PMS risk compared with those exposed to Q1-level PM2.5 (95% CI = 2.88-4.04). CONCLUSIONS High incidences of PMS were noted in women who lived in areas with higher concentrations of SO2, NOx, NO, NO2, and PM2.5. © The Author(s) 2020. Published by Oxford University Press on behalf of the Association of Physicians. All rights reserved. For Permissions, please email journals.permissions@oup.com.Drought limits the long-distance transport of water in the xylem due to the reduced leaf-to-soil water potential difference and possible embolism-related losses of conductance, and of sugars in the phloem due to the higher viscosity of the dehydrated sugary solution. This condition can have cascading effects in water and carbon fluxes that may ultimately cause tree death. We hypothesize that the maintenance of xylem and phloem conductances is fundamental for survival also under reduced resource availability, when trees may produce effective and low C cost anatomical adjustments in the xylem and phloem close to the treetop where most of the hydraulic resistance is concentrated. © The Author(s) 2020. Published by Oxford University Press. All rights reserved. For permissions, please e-mail journals.permission@oup.com.Arbuscular mycorrhizas (AM) prevail in warm and dry climates and ectomycorrhizas (EM) in cold and humid climates. We suggest that the fungal symbionts benefit their host plants especially in the corresponding conditions. The hypothesis tested was that AM plants are more drought resistant than EM or non-mycorrhizal (NM) plants. © The Author(s) 2020. Published by Oxford University Press. All rights reserved. For permissions, please e-mail journals.permission@oup.com.OBJECTIVE Given the changing political and social climate around opioids, we examined how clinicians in the outpatient setting made decisions about managing opioid prescriptions for new patients already on long-term opioid therapy. METHODS We conducted in-depth interviews with 32 clinicians in Southern California who prescribed opioid medications in the outpatient setting for chronic pain. The study design, interview guides, and coding for this qualitative study were guided by constructivist grounded theory methodology. RESULTS We identified three approaches to assuming a new patient's opioid prescriptions. Staunch Opposers, mostly clinicians with specialized training in pain medicine, were averse to continuing opioid prescriptions for new patients and often screened outpatients seeking opioids. Cautious and Conflicted Prescribers were wary about prescribing opioids but were willing to refill prescriptions if they perceived the patient as trustworthy and the medication fell within their comfort zone. Clinicians in the first two groups felt resentful about other clinicians "dumping" patients on opioids on them. Rapport Builders, mostly primary care physicians, were the most willing to assume opioid prescriptions and were strategic in their approach to transitioning patients to safer doses. CONCLUSIONS Clinicians with the most training in pain management were the least willing to assume responsibility for opioid prescriptions for patients already on long-term opioid therapy. In contrast, primary care clinicians were the most willing to assume this responsibility. However, primary care clinicians face barriers to providing high-quality care for patients with complex pain conditions, such as short visit times and less specialized training. © The Author(s) 2020. Published by Oxford University Press on behalf of the American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.