A unit pipe pneumatic model to simulate gas kinetics during measurements of embolism in excised angiosperm xylem.

The pneumatic method has been introduced to quantify embolism resistance in plant xylem of various organs by applying a partial vacuum to cut-open xylem. Despite the similarity in vulnerability curves between the pneumatic and other methods, a modeling approach is needed to investigate if changes in xylem embolism during dehydration can be accurately quantified based on gas diffusion kinetics. Therefore, a unit pipe pneumatic (UPPn) model was developed to estimate gas extraction from intact conduits, which were axially interconnected by inter-conduit pit membranes to cut-open conduits. The physical laws used included Fick's law for diffusion, Henry's law for gas concentration partitioning between liquid and gas phases at equilibrium and the ideal gas law. The UPPn model showed that 91% of the extracted gas came from the first five series of embolized, intact conduits and only 9% from the aqueous phase after 15 s of simulation. Considering alternative gas sources, embolism resistance measured with a pneumatron device was systematically overestimated by 2-17%, which corresponded to a typical measuring error of 0.11 MPa for P50 (the water potential equivalent to 50% of the maximum amount of gas extracted). It is concluded that pneumatic vulnerability curves directly measure embolism of intact conduits due to the fast movement of gas across interconduit pit membranes, while gas extraction from sap and diffusion across hydrated cell walls is about 100 times slower. We expect that the UPPn model will also contribute to the understanding of embolism propagation based on temporal gas dynamics.

The theory behind vessel length determination using gas flow rates and comparison between two pneumatic methods based on seven woody species.

In plants, xylem vessel length is important for long-distance water transport; however, the currently used methods for vessel length measurement are inconvenient and time-consuming. The recently developed semi-automated Pneumatron is a device based on the pneumatic theory that is similar to the air-injection method, and can rapidly estimate vessel length. Mean vessel length was compared between the Pneumatron and the air-injection method in seven woody species with a wide range of vessel lengths (2.3-78.7 cm). The results were consistent between the two methods, regardless of whether the same or different samples were used. The theory underlying the gas flow in vessels was improved and expanded, and compared to that underlying the water flow in order to better understand the pneumatic processes within a stem sample. Moreover, a new and simple equation for gas flow in vessels was derived based on the molar gas flow (mol s-1) rather than volume flow, because the former remains constant with distance throughout the stem axis. We strongly recommend using the Pneumatron in future studies owing to its low cost, convenience, rapidity, and simple operation. However, a number of potential issues need to be considered to avoid artifacts during measurements.

Anti-Racism Strategies in Pediatric Psychology: Using STYLE Can Help Children Overcome Adverse Experiences With Police.

Black children are exposed to police violence at alarming rates. Such stress impacts development and treatment of physical health problems. In the current discourse, we introduce STYLE (Self-examination, Talk about community-police relations and racism, Yield space and time to anti-racism work, Learn about how structural racism impacts child health, Evaluate policies and practices through an anti-racism lens). STYLE offers a framework through which professionals in pediatric psychology can engage in anti-racist work across contexts from clinical care to academic and advocacy settings. Pediatric psychologists have a responsibility to be on the frontline as interventionists, educators, researchers, organizers, and advocates for racial justice through anti-racism practices. The current paper introduces STYLE in clinical care, community service, training/supervision, and academic and advocacy contexts. Case examples are provided. Professionals in pediatric psychology must first focus on changing their STYLE to promote individual and infrastructural change consistent with anti-racism work.

Improved clinical investigation and evaluation of high-risk medical devices: the rationale and objectives of CORE-MD (Coordinating Research and Evidence for Medical Devices).

In the European Union (EU) the delivery of health services is a national responsibility but there are concerted actions between member states to protect public health. Approval of pharmaceutical products is the responsibility of the European Medicines Agency, whereas authorizing the placing on the market of medical devices is decentralized to independent 'conformity assessment' organizations called notified bodies. The first legal basis for an EU system of evaluating medical devices and approving their market access was the medical device directives, from the 1990s. Uncertainties about clinical evidence requirements, among other reasons, led to the EU Medical Device Regulation (2017/745) that has applied since May 2021. It provides general principles for clinical investigations but few methodological details-which challenges responsible authorities to set appropriate balances between regulation and innovation, pre- and post-market studies, and clinical trials and real-world evidence. Scientific experts should advise on methods and standards for assessing and approving new high-risk devices, and safety, efficacy, and transparency of evidence should be paramount. The European Commission recently awarded a Horizon 2020 grant to a consortium led by the European Society of Cardiology and the European Federation of National Associations of Orthopaedics and Traumatology, that will review methodologies of clinical investigations, advise on study designs, and develop recommendations for aggregating clinical data from registries and other real-world sources. The CORE-MD project (Coordinating Research and Evidence for Medical Devices) will run until March 2024; here we describe how it may contribute to the development of regulatory science in Europe.

How trees thrive in a dry climate: diurnal and seasonal hydrology and water relations in a riparian cottonwood grove.

In semi-arid ecoregions, trees are restricted to river valley floodplains where river water supplements the limited precipitation. To characterize the associated diurnal and seasonal dynamics in hydrology and water relations, we studied narrowleaf cottonwoods (Populus angustifolia) along a prairie river in Canada. From June through August, the shallow soil moisture was depleted but moisture remained higher above the alluvial groundwater table, which dropped to 2.3 m along with river recession. Throughout the summer, with the daily rise in temperature and insolation, foliar stomatal conductance (gs) and transpiration (E) increased to midday and then fell, thus maintaining the midday leaf water potential (Ψmd) above ~-1.7 MPa. This Ψmd approximated the water potential associated with 12% loss of xylem conductivity due to cavitation for branches (P12); the Ψmd and P12 varied independently across eight trees, providing differences in relative hydraulic risk. Sap flux density (Fd) was measured with thermal dissipation probes, and revealed diurnal patterns similar to foliar E. In contrast to our expectation, the daily Fd maxima were consistent through the summer despite the seasonal recession in water supply. Canopy conductances (GS), derived from Fd, sapwood area and canopy area, declined with vapor pressure deficit (D) and fell slightly in late summer along with stomatal sensitivity, which reflects the magnitude of decrease in GS with increasing D. For spatial up-scaling, satellite-derived near-infrared reflectance of vegetation revealed the woodland phenology, with leaf expansion from May through June and gradual decline in photosynthetic productivity through the summer. Thus, the phreatophytic cottonwoods: (i) sustained substantial water use and productivity through the warm and dry summer, by (ii) accessing shallow soil moisture and then deeper alluvial groundwater, and (iii) providing diurnal stomatal regulation, to (iv) avoid xylem cavitation and (v) maintain fairly constant hydraulic conductance.

The hydraulic architecture of an arborescent monocot: ontogeny-related adjustments in vessel size and leaf area compensate for increased resistance.

Bamboos are arborescent monocotyledons that have no secondary growth, but can continually produce conduits with diameters appropriate to the current size of the plant. Here, we studied bamboo hydraulic architecture to address the mechanisms involved in compensating for the increase in hydraulic resistance during ontogeny. We measured the hydraulic weighted vessel diameters (Dh ) at different distances from the apex along the stem of Bambusa textilis. The hydraulic resistance of different components and individuals of different heights were quantified using the high-pressure flowmeter method. The Dh showed tip-to-base widening with a scaling exponent in the range of those reported for trees. Although theoretical hydraulic conductivity decreased from base-to-tip, leaf-specific conductivity did not change. Leaves contributed the most to the whole-shoot hydraulic resistance, followed by the leaf-bearing branches. Roots contributed c. 13% to whole-plant resistance. Interestingly, taller individuals showed lower whole-shoot resistance owing to an increased number of resistances in parallel (side-branches), while leaf-specific resistance was independent of plant size. Tip-to-base vessel widening and height-independent constant leaf-specific conductance could be mechanisms for hydraulic optimization in B. textilis. Similar patterns have also been found in woody plants with secondary growth, but this bamboo exhibits them without secondary growth.

Standard-Dose Osimertinib in EGFR-Mutated Non-Small-Cell Lung Adenocarcinoma With Leptomeningeal Disease.

PURPOSE: Leptomeningeal disease (LMD) in epidermal growth factor receptor (EGFR)-mutant lung adenocarcinoma is associated with a poor prognosis and limited treatment options. Osimertinib is a potent third-generation EGFR tyrosine kinase inhibitor with confirmed CNS penetration. This study reports on outcomes of patients with EGFR-mutated non-small-cell lung cancer who developed LMD and were subsequently treated with osimertinib. METHODS: We identified patients treated with osimertinib 80 mg PO daily under a compassionate access scheme across nine tertiary Australian institutes between July 2017 and July 2020. Patient demographics, tumor characteristics, and treatment history were collected. Median overall survival, median progression-free survival, disease control rates (DCR), and overall response rates (ORR) were assessed. Kaplan-Meier analysis was performed and descriptive statistics were used. RESULTS: Thirty-nine patients were analyzed of which 74% were female. Exon 19 deletions (49%) and L858R point mutations (41%) were the most common EGFR mutations. Forty-nine percentage of patients were Eastern Cooperative Oncology Group 1. The median duration of osimertinib therapy was 6 months. The extracranial DCR and ORR were 60% and 54%, and the intracranial DCR and ORR were 68% and 53%, respectively. Median overall survival was 10.5 months (95% CI, 8.17 to 15.05 months). CONCLUSION: There are limited treatment options for LMD in EGFR-positive lung cancer, and osimertinib at a dose of 80 mg daily is an active therapeutic option for these patients.

Complementary, Integrative, and Nondrug Therapy Use for Pain Among US Military Veterans on Long-term Opioids.

BACKGROUND: Long-term opioid therapy for chronic pain arose amid limited availability and awareness of other pain therapies. Although many complementary and integrative health (CIH) and nondrug therapies are effective for chronic pain, little is known about CIH/nondrug therapy use patterns among people prescribed opioid analgesics. OBJECTIVE: The objective of this study was to estimate patterns and predictors of self-reported CIH/nondrug therapy use for chronic pain within a representative national sample of US military veterans prescribed long-term opioids for chronic pain. RESEARCH DESIGN: National two-stage stratified random sample survey combined with electronic medical record data. Data were analyzed using logistic regressions and latent class analysis. SUBJECTS: US military veterans in Veterans Affairs (VA) primary care who received ≥6 months of opioid analgesics. MEASURES: Self-reported use of each of 10 CIH/nondrug therapies to treat or cope with chronic pain in the past year: meditation/mindfulness, relaxation, psychotherapy, yoga, t'ai chi, aerobic exercise, stretching/strengthening, acupuncture, chiropractic, massage; Brief Pain Inventory-Interference (BPI-I) scale as a measure of pain-related function. RESULTS: In total, 8891 (65%) of 13,660 invitees completed the questionnaire. Eighty percent of veterans reported past-year use of at least 1 nondrug therapy for pain. Younger age and female sex were associated with the use of most nondrug therapies. Higher pain interference was associated with lower use of exercise/movement therapies. Nondrug therapy use patterns reflected functional categories (psychological/behavioral, exercise/movement, manual). CONCLUSIONS: Use of CIH/nondrug therapies for pain was common among patients receiving long-term opioids. Future analyses will examine nondrug therapy use in relation to pain and quality of life outcomes over time.

Yoga Practice Among Veterans With and Without Chronic Pain: A Mixed Methods Study.

OBJECTIVES: The primary aim of this study was to examine differences in yoga practice between persons with and without chronic pain. Secondarily, we describe use of the Essential Properties of Yoga Questionnaire, Short Form (EPYQ-SF) for self-report. DESIGN: Participants were members of an existing cohort of veterans who completed a 2015-2016 survey focused on pain and nonpharmacological health practices. Cohort members who reported yoga in the past year [n=174 (9.4%) of 1850] were eligible for the present study, which used multiple-contact mixed-mode survey methodology to collect data on yoga practices. The EPYQ-SF was used to assess properties and context of yoga practice. Practice patterns were compared for participants with and without chronic pain. To explore potential reasons for reported yoga practice patterns, focused semistructured interviews were conducted with a subset of participants. RESULTS: Of 174 participants contacted, 141 (82%) returned the yoga questionnaire and 110 (78% of respondents) were still practicing yoga. Among yoga practitioners, 41 (37%) had chronic pain. Practitioners with chronic pain reported gentler (2.8 vs. 3.1, 5-point scale) and less active (2.9 vs. 3.3) yoga practice than those without. Those with chronic pain attended yoga studios less frequently and reported shorter yoga practices than those without. Most yoga practice was self-directed and at home. CONCLUSIONS: Differences in yoga practice of persons with and without chronic pain have implications for implementation of yoga interventions for chronic pain. Future interventions should focus on alternative individual delivery formats or addressing barriers to group practice among people with chronic pain.

The evaluating prescription opioid changes in veterans (EPOCH) study: Design, survey response, and baseline characteristics.

In the United States (US), long-term opioid therapy has been commonly prescribed for chronic pain. Since recognition of the opioid overdose epidemic, clinical practice guidelines have recommended tapering long-term opioids to reduced doses or discontinuation. The Effects of Prescription Opioid Changes for veterans (EPOCH) study is a national population-based prospective observational study of US Veterans Health Administration primary care patients designed to assess effects of evolving opioid prescribing practice on patients treated with long-term opioids for chronic pain. A stratified random sampling design was used to identify a survey sample from the target population of patients treated with opioid analgesics for ≥ 6 months. Demographic, diagnostic, visit, and pharmacy dispensing data were extracted from existing datasets. A 2016 mixed-mode mail and telephone survey collected patient-reported data, including the main patient-reported outcomes of pain-related function (Brief Pain Inventory interference; BPI-I scores 0-10, higher scores = worse) and health-related quality of life. Data on survey participants and non-participants were analyzed to assess potential nonresponse bias. Weights were used to account for design. Linear regression models were used to assess cross-sectional associations of opioid treatment with patient-reported measures. Of 14,160 patients contacted, 9253 (65.4%) completed the survey. Participants were older than non-participants (63.9 ± 10.6 vs. 59.6 ± 13.0 years). The mean number of bothersome pain locations was 6.8 (SE 0.04). Effectiveness of pain treatment and quality of pain care were rated fair or poor by 56.1% and 45.3%, respectively. The opioid daily dosage range was 1.6 to 1038.2 mg, with mean = 50.6 mg (SE 1.1) and median = 30.9 mg (IQR 40.7). Among the 73.2% of patients who did not receive long-acting opioids, the mean daily dosage was 30.4 mg (SE 0.6) and mean BPI-I was 6.4 (SE 00.4). Among patients who received long-acting opioids, the mean daily dosage was 106.2 mg (SE 2.8) and mean BPI-I was 6.8 (SE 0.07). Higher daily dosage was associated with worse pain-related function and quality of life among patients without long-acting opioids, but not among patients with long-acting opioids. Future analyses will use follow-up data to examine effects of opioid dose reduction and discontinuation on patient outcomes.

Inferring the role of pit membranes in solute transport from solute exclusion studies in living conifer stems.

The functional role of pits between living and dead cells has been inferred from anatomical studies but amassing physiological evidence has been challenging. Centrifugation methods were used to strip water from xylem conduits, permitting a more quantitative gravimetric determination of the water and solid contents of cell walls than is possible by more traditional methods. Quantitative anatomical evidence was used to evaluate the water volume in xylem conduits and the water content of living cells. Quantitative perfusion of stems with polyethylene glycol of different molecular weight was used to determine the solute-free space. We measured the portioning of water and solute-free space among anatomical components in stems and demonstrated that lignin impeded the free movement of solutes with molecular weight >300. Hence, movement of large solutes from living cells to xylem conduits is necessarily confined to pit structures that permit transmembrane solute transport via primary walls without lignin. The functional role of pits was additionally indicated by combining data in this paper with previous studies of unusual osmotic relationships in woody species that lack pits between dead wood fibers and vessels. The absence of pits, combined with the evidence of exclusion of solutes of molecular weight >300, explains the unexpected osmotic properties.

Sleep Disturbance Predicts Less Improvement in Pain Outcomes: Secondary Analysis of the SPACE Randomized Clinical Trial.

OBJECTIVE: Sleep disturbance may limit improvement in pain outcomes if not directly addressed in treatment. Moreover, sleep problems may be exacerbated by opioid therapy. This study examined the effects of baseline sleep disturbance on improvement in pain outcomes using data from the Strategies for Prescribing Analgesics Comparative Effectiveness (SPACE) trial, a pragmatic 12-month randomized trial of opioid vs nonopioid medication therapy. DESIGN: Participants with chronic back pain or hip or knee osteoarthritis pain were randomized to either opioid therapy (N = 120) or nonopioid medication therapy (N = 120). METHODS: We used mixed models for repeated measures to 1) test whether baseline sleep disturbance scores modified the effect of opioid vs nonopioid treatment on pain outcomes and 2) test baseline sleep disturbance scores as a predictor of less improvement in pain outcomes across both treatment groups. RESULTS: The tests for interaction of sleep disturbance by treatment group were not significant. Higher sleep disturbance scores at baseline predicted less improvement in Brief Pain Inventory (BPI) interference (ß = 0.058, P = 0.0002) and BPI severity (ß = 0.026, P = 0.0164). CONCLUSIONS: Baseline sleep disturbance adversely affects pain response to treatment regardless of analgesic regimen. Recognition and treatment of sleep impairments that frequently co-occur with pain may optimize outcomes.

The Pneumatron: An automated pneumatic apparatus for estimating xylem vulnerability to embolism at high temporal resolution.

Xylem vulnerability to embolism represents an important trait to determine species distribution patterns and drought resistance. However, estimating embolism resistance frequently requires time-consuming and ambiguous hydraulic lab measurements. Based on a recently developed pneumatic method, we present and test the "Pneumatron", a device that generates high time-resolution and fully automated vulnerability curves. Embolism resistance is estimated by applying a partial vacuum to extract air from an excised xylem sample, while monitoring the pressure change over time. Although the amount of gas extracted is strongly correlated with the percentage loss of xylem conductivity, validation of the Pneumatron was performed by comparison with the optical method for Eucalyptus camaldulensis leaves. The Pneumatron improved the precision of the pneumatic method considerably, facilitating the detection of small differences in the (percentage of air discharged [PAD] < 0.47%). Hence, the Pneumatron can directly measure the 50% PAD without any fitting of vulnerability curves. PAD and embolism frequency based on the optical method were strongly correlated (r2 = 0.93) for E. camaldulensis. By providing an open source platform, the Pneumatron represents an easy, low-cost, and powerful tool for field measurements, which can significantly improve our understanding of plant-water relations and the mechanisms behind embolism.

An improved centrifuge method for determining water extraction curves and vulnerability curves in the long-vessel species Robinia pseudoacacia.

Significant improvements to the centrifuge water-extraction method of measuring the percentage loss volume of water (PLV) and corresponding vulnerability curves (VCs) are reported. Cochard and Sperry rotors are both incapable of measuring the VCs of species with long vessels because of premature embolism induced by hypothetical nanoparticles that can be drawn into segments during flow measurement. In contrast, water extraction pushes nanoparticles out of the sample. This study focuses on a long-vessel species, Robinia pseudoacacia, for which many VCs have been constructed by different methods, and the daily water relations have been quantified. PLV extraction curves have dual Weibull curves, and this paper focuses on the second Weibull curve because it involves the extraction of water from vessels, as proven by staining methods. We demonstrate an improved water extraction method after evaporation correction that has accuracy to within 0.5%, shows good agreement with two traditional methods that are slower and less accurate, and is immune to nanoparticle artefacts. Using Poiseuille's Law and the geometry of vessels, we argue that the percentage loss of conductivity (PLC) equals 2PLV-PLV2 in a special case where all vessels, regardless of size, have the same vulnerability curve. In this special case, this equation predicts the data reasonably well.

How does water flow from vessel to vessel? Further investigation of the tracheid bridge concept.

Hydraulic safety and efficiency have become the central concept of the interpretation of the structure and function of vessels and their interconnections. Plants form an appropriate xylem network structure to maintain a balance of hydraulic safety vs efficiency. The term 'tracheid bridge' is used to describe a possible pathway of water transport between neighboring vessels via tracheids, and this pathway could also provide increased safety against embolisms. However, the only physiological study of such a structure thus far has been in Hippophae rhamnoides Linn. To test the function of tracheid bridges, this research examined four species that have relatively long and solitary vessels, which are two of the criteria for efficient tracheid bridges. Tracheids contributed less than 2.2% of the total conductance of the vessels in these species, but in theory, tracheids could serve as very efficient transport connector pathways that may or may not make direct vessel-to-vessel contact via pit fields between adjacent vessels. In some species, tracheid bridges may represent the dominant pathway for water flow between vessels, whereas in other species, tracheid bridges may be sub-dominant or virtually nil. Broader searches of woody taxa are needed to reveal the functional importance of tracheid bridges in vascular plants.

Do nano-particles cause recalcitrant vulnerability curves in Robinia? Testing with a four-cuvette Cochard rotor and with water extraction curves.

Cavitation resistance is a key trait for characterizing the drought adaption in plants and is usually presented in terms of vulnerability curves. Three principal techniques have been developed to produce vulnerability curves, but curves generated with centrifugation are reported to suffer from artifacts when applied to long-vesseled species. The main cause of this artifact is the issue of open vessels, resulting in a nano-particle effect that may seed premature embolism. We used two methods to test the potential mechanism behind the nano-particle effect in centrifuge-based vulnerability curves. A four-cuvette rotor system based on a traditional Cochard rotor was designed to inhibit effervescence while injecting water, but the recalcitrant vulnerability curves in Robinia could not be eliminated. There may be multiple sources, besides effervescence, of hypothetical nano-particles: they may arise from cut surfaces or they may be always present in the injected water, leading to the premature embolisms. To prevent the entry of the hypothetical nano-particles, water extraction curves in terms of PLV (percentage loss volume of extracted water from stems) vs tensions were constructed. The PLV curves of Robinia showed s-shaped characteristics after subtracting the first Weibull components from water extraction curves, which were not related to the water loss from vessels according to dye staining experiments. The differences between T50 (xylem tension at which 50% of hydraulic conductivity is lost) in mean PLV curve and T50 in percentage loss of conductivity curves determined by the four-cuvette rotor system and by the bench dehydration method were 3.9 MPa and 0.7 MPa, respectively. Hence, PLV curves may be a valid way to measure the cavitation resistance in long-vesseled species with centrifugation. Keeping bark intact in the process of measurement is recommended, otherwise it would increase evaporation from the entire system.

Patterns of conventional and complementary non-pharmacological health practice use by US military veterans: a cross-sectional latent class analysis.

BACKGROUND: Non-pharmacological therapies and practices are commonly used for both health maintenance and management of chronic disease. Patterns and reasons for use of health practices may identify clinically meaningful subgroups of users. The objectives of this study were to identify classes of self-reported use of conventional and complementary non-pharmacological health practices using latent class analysis and estimate associations of participant characteristics with class membership. METHODS: A mailed survey (October 2015 to September 2016) of Minnesota National Guard Veterans from a longitudinal cohort (n = 1850) assessed current pain, self-reported overall health, mental health, substance use, personality traits, and health practice use. We developed the Health Practices Inventory, a self-report instrument assessing use of 19 common conventional and complementary non-pharmacological health-related practices. Latent class analysis was used to identify subgroups of health practice users, based on responses to the HPI. Participants were assigned to their maximum-likelihood class, which was used as the outcome in multinomial logistic regression to examine associations of participant characteristics with latent class membership. RESULTS: Half of the sample used non-pharmacological health practices. Six classes of users were identified. "Low use" (50%) had low rates of health practice use. "Exercise" (23%) had high exercise use. "Psychotherapy" (6%) had high use of psychotherapy and support groups. "Manual therapies" (12%) had high use of chiropractic, physical therapy, and massage. "Mindfulness" (5%) had high use of mindfulness and relaxation practice. "Multimodal" (4%) had high use of most practices. Use of manual therapies (chiropractic, acupuncture, physical therapy, massage) was associated with chronic pain and female sex. Characteristics that predict use patterns varied by class. Use of self-directed practices (e.g., aerobic exercise, yoga) was associated with the personality trait of absorption (openness to experience). Use of psychotherapy was associated with higher rates of psychological distress. CONCLUSIONS: These observed patterns of use of non-pharmacological health practices show that functionally similar practices are being used together and suggest a meaningful classification of health practices based on self-directed/active and practitioner-delivered. Notably, there is considerable overlap in users of complementary and conventional practices.

"I Was a Little Surprised": Qualitative Insights From Patients Enrolled in a 12-Month Trial Comparing Opioids With Nonopioid Medications for Chronic Musculoskeletal Pain.

Chronic musculoskeletal pain is a major public health problem. Although opioid prescribing for chronic pain has increased dramatically since the 1990s, this practice has come under scrutiny because of increases in opioid-related harms and lack of evidence for long-term effectiveness. The Strategies for Prescribing Analgesics Comparative Effectiveness (SPACE) trial was a pragmatic 12-month randomized trial comparing the benefits and harms of opioid versus nonopioid medications for chronic musculoskeletal pain. The current qualitative study was designed to better understand trial results by exploring patients' experiences, including perceptions of medications, experiences with the intervention, and whether expectations were met. Thirty-four participants who were purposefully sampled based on treatment group and intervention response participated in semistructured interviews. The constant comparison method guided analysis. Results revealed that participants often held strong beliefs about opioid medications, which sometimes changed during the trial as they gained experience with medications; participants described a wide variety of experiences with treatment effectiveness, regardless of study group or their response to the intervention; and participants highly valued the personalized pain care model used in SPACE. PERSPECTIVE: SPACE trial results indicated no advantage for opioid over nonopioid medications. Qualitative findings suggest that, for both treatment groups, preexisting expectations and anticipated improvement in pain shaped experiences with and responses to medications. The personalized pain care model was described as contributing to positive outcomes in both groups.

Seasonality of cavitation and frost fatigue in Acer mono Maxim.

Although cavitation is common in plants, it is unknown whether the cavitation resistance of xylem is seasonally constant or variable. We tested the changes in cavitation resistance of Acer mono before and after a controlled cavitation-refilling and freeze-thaw cycles for a whole year. Cavitation resistance was determined from 'vulnerability curves' showing the percent loss of conductivity versus xylem tension. Cavitation fatigue was defined as a reduction of cavitation resistance following a cavitation-refilling cycle, whereas frost fatigue was caused by a freeze-thaw cycle. A. mono developed seasonal changes in native embolisms; values were relatively high during winter but relatively low and constant throughout the growing season. Cavitation fatigue occurred and changed seasonally during the 12-month cycle; the greatest fatigue response occurred during summer and the weakest during winter, and the transitions occurred during spring and autumn. A. mono was highly resistant to frost damage during the relatively mild winter months; however, a quite different situation occurred during the growing season, as the seasonal trend of frost fatigue was strikingly similar to that of cavitation fatigue. Seasonality changes in cavitation resistance may be caused by seasonal changes in the mechanical properties of the pit membranes.