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Plants are able to actively detect and respond to the presence in neighboring plants, in order to optimize their physiology to promote survival and reproduction despite the presence of competing organisms. A key but still poorly understood mechanism for neighbor detection is through the perception of root exudates. In this review, we explore recent findings on the role of root exudates in plant–plant interactions, focusing both on general interactions and also the highly specialized example of root parasite–host plant interactions. [ABSTRACT FROM AUTHOR]

Many aspects of development in the model plant Arabidopsis thaliana involve regulated distribution of the hormone auxin by the PIN-FORMED (PIN) family of auxin efflux carriers. The role of PIN-mediated auxin transport in other plants is not well understood, but studies in a wider range of species have begun to illuminate developmental mechanisms across land plants. In this review, I discuss recent progress in understanding the evolution of PIN-mediated auxin transport, and its role in development across the green plant lineage. I also discuss the idea that changes in auxin biology led to morphological novelty in plant development: currently available evidence suggests major innovations in auxin transport are rare and not associated with the evolution of new developmental mechanisms. [ABSTRACT FROM AUTHOR]

Strigolactones are an ancient and major class of endogenous plant growth regulators. Although only recently identified, rapid progress has been made in understanding strigolactone biology, including the identification of a signalling pathway involving DWARF14 α/β-fold proteins, the SCF MAX2 ubiquitin ligase and SMAX1-LIKE (SMXL) family of chaperonin-like proteins. Several rapid effects of strigolactone signalling have also been identified, including endocytosis of the PIN-FORMED1 (PIN1) auxin efflux carrier and transcript accumulation of the BRANCHED1 (BRC1) transcription factor. Here we assess our current knowledge of strigolactone signalling, and discuss how increased understanding of the cell biology of the system can help to resolve some of the current uncertainties in the field. [ABSTRACT FROM AUTHOR]

Background In patients with pulmonary arterial hypertension (PAH) the relationship between hemodynamic impairment experienced during daily activity and that during exercise testing is not known. Methods and Results Ten PAH patients received an implantable hemodynamic monitor that continuously recorded and stored right ventricular systolic (RVSP) and mean pulmonary arterial (MPAP) pressures. Before starting a new PAH treatment (baseline) and after 12 weeks on treatment, a 6-minute walk test (6MWT) and a maximal walk test (MAXWT) were performed. Exercise pressure range was measured as the difference between rest before exercise and maximal pressure during 6MWT or MAXWT. Ambulatory range (AMB) was measured as the difference between the lowest (4th percentile) and highest (96th percentile) values recorded over 24 hours. One week of AMBs were averaged for each patient before each exercise test. Mean age was 54 ±18 years, 9 were female, and all were in World Health Organization functional class III. At baseline, RVSP and MPAP increased, respectively, 136 ± 49% and 164 ± 49% during AMB, 63 ± 26% and 79 ± 30% during MAXWT, and 59 ± 32% and 69 ± 33% during 6MWT. There was no difference in pressure change at 12 weeks. Conclusions Changes in RV and PA pressures during exercise tests were relatively small compared with the range seen during ambulatory conditions. [ABSTRACT FROM AUTHOR]

Highlights: [•] Modeling has provided insight into the self-organization of plant development and auxin transport. [•] Realistic patterns of PIN auxin transporter accumulation can be modeled by using either net auxin flux across the plasma membrane or by auxin concentration in neighboring cells to drive PIN localization. [•] The biological mechanisms that polarize auxin transporters are not well understood. [•] The same molecular mechanisms may underlie both theoretical heuristics. [•] Improved experimental systems for studying canalization, and feedback-driven PIN polarization in general, are required. [Copyright &y& Elsevier]

Abstract: Background: The purpose of this study was to develop an automated surveillance system, using pressure-based hemodynamic factors that would detect which patients were making the transition from compensated to decompensated heart failure before they developed worsening symptoms and required acute medical care. Methods and Results: Intracardiac pressures in 274 patients with heart failure were measured using an implantable hemodynamic monitor (IHM) and were analyzed in a retrospective manner. An automated pressure change detection (PCD) algorithm was developed using the cumulative sum method. The performance characteristics of the PCD algorithm were defined in all patients who developed a heart failure–related event (HFRE); patients without HFRE served as controls. Optimal PCD threshold values were chosen using a receiver operator curve analysis. Each of the pressures measured with the IHM were evaluated using the PCD analysis. All had sensitivities ≥80% and false-positive rates <4.7/patient-year; however, estimated pulmonary artery diastolic pressure (ePAD) had the best performance. An ePAD based on the optimized PCD threshold of 6.0 yielded a sensitivity of 83% and a false-positive rate of 4.1/patient-year for detecting patients making the transition from compensated to decompensated heart failure. These performance characteristics were not significantly different for patients with an ejection fraction > vs. <50%, estimated glomerular filtration rate > vs. <60 mL/min/1.73 m2, or age > vs. <60 years. Conclusions: The automated PCD algorithm had high sensitivity and acceptable false-positive rates in detecting the development of decompensated heart failure before the patient developed worsening symptoms and required acute medical care. These data support the development of a prospective study to examine the utility of adding an automated PCD algorithm to IHM-based management strategies to prevent decompensated heart failure. [Copyright &y& Elsevier]

Abstract: Background: The purpose of this study was to determine which pressure-based hemodynamic factor was most closely associated with the transition from chronic compensated to acute decompensated heart failure. Methods and Results: Intracardiac pressures were retrospectively examined in 274 heart failure patients using an implantable hemodynamic monitor. The relationship between the development of a heart failure–related event (HFRE) and 3 pressure variables were analyzed: peak estimated pulmonary artery diastolic pressure (ePAD) at the time of an HFRE, change in ePAD from baseline to peak pressure, and the product of ePAD pressure and time (P×T) calculated as the area under the pressure-versus-time curve from baseline to peak pressure. Patients without an HFRE served as control subjects. Peak ePAD and change in ePAD were not closely associated with the development of an HFRE. In patients with an HFRE, P×T was 221 ± 130 mm Hg·days with only 4% of the P×T values <60 mm Hg·days. In contrast, in patients without an HFRE, the P×T was 5 ± 23 with only 4% of the P×T values >60 mm Hg·days. Conclusions: The product of small increases in pressure that occur over an extended period of time (P×T) is the pressure-based hemodynamic factor most closely associated with the transition to acute decompensated heart failure. [Copyright &y& Elsevier]

Abstract: Background: Nearly half of all patients with chronic heart failure (HF) have a normal ejection fraction (EF), and abnormal diastolic function (ie, diastolic heart failure [DHF]). However, appropriate management of DHF patients remains a difficult and uncertain challenge. Methods and Results: The Chronicle Offers Management to Patients with Advanced Signs and Symptoms of Heart Failure (COMPASS-HF) trial was designed to evaluate whether an implantable hemodynamic monitor (IHM) was safe and effective in reducing the number of heart failure–related events (HFRE) in patients with chronic HF. The current study presents data on a prespecified and planned subgroup analysis from the COMPASS-HF trial: 70 patients with an EF ≥50% (ie, DHF). As such, this represents a subgroup analysis of the COMPASS-HF Trial. DHF patients were randomized to IHM-guided care (treatment) vs. standard care (control) for 6 months. All 70 patients received optimal medical therapy, but the hemodynamic information from the IHM was used to guide patient management only in the treatment group. The HFRE rate in DHF patients randomized to treatment was 0.58 events/6 months compared with DHF patients randomized to control, which was 0.73 events/6 months; this represented a 20% nonsignificant reduction in the overall HFRE rate in the treatment group (95% CI = –46, 56, P = .66). There was a 29% nonsignificant reduction in the relative risk of a HF hospitalization in the DHF patients randomized to treatment compared with DHF patients randomized to control (95% CI = –69, 70, P = .43). Conclusions: The IHM was shown to be safe and was associated with a very low system-related and procedure-related complication rate in DHF patients. However, in this subgroup analysis limited to 70 DHF patients, the addition IHM-guided care did not significantly lower the rate of HFR events. The results of this subgroup analysis in DHF patients, for whom there are currently no proven, effective management strategies, will be used to design future studies defining the effects of IHM-guided care in patients with DHF. [Copyright &y& Elsevier]

Background: Childhood obesity has become a serious global healthcare challenge. No UK data currently define its anaesthetic and perioperative implications. We aimed to determine obesity prevalence amongst UK children undergoing general anaesthesia and the incidence of predefined adverse perioperative events, and to compare perioperative obesity rates with National Child Measurement Programme (NCMP) data.Methods: During a site-selected consecutive 7-day study period, all children (2-16 yr) undergoing general anaesthesia were included. Anonymised hospital, surgical, and procedural details; demographic data; and adverse perioperative events were collected prospectively by Paediatric Anaesthesia Trainee Research Network (PATRN) collaborators.Results: For this study, 102 UK hospitals participated and 4232 cases were included in the final analysis; 76% of hospitals did not routinely calculate BMI. In addition, 3030 (71.6%; 95% confidence interval [CI]: 70.2-73.0%) children of healthy weight were compared with 537 (12.7%; 11.7-13.7%) children who were overweight and 478 (11.3%; 10.3-12.2%) children with obesity. Children with obesity (n=71; 14.9%) more commonly underwent (adeno)tonsillectomy than children of healthy weight (n=282; 9.3%; P<0.001; odds ratio [OR] 2.15; 95% CI: 1.58-2.92). Fewer children with obesity (n=365; 77% vs n=2552; 85%) were anaesthetised by consultant anaesthetists (OR 0.62; 95% CI: 0.48-0.79). Mask ventilation was difficult for 3.7% of children with obesity vs 0.6% of children of healthy weight (difference 3.0%; 95% CI: 1.3-4.7%; P<0.001). Comparison with NCMP data demonstrated an over-representation of obesity amongst the paediatric surgical population.Conclusions: This large multicentre cohort study suggests a concerning prevalence of children with obesity presenting for anaesthesia. These results should be used to inform optimal provision of care for this population and support perioperative healthcare initiatives to address the burden of childhood obesity.Clinical Trial Registration: ClinicalTrials.gov Identifier: NCT03994419. [ABSTRACT FROM AUTHOR]

The reproduction of flowering plants is an incredibly important process, both ecologically and economically. A huge body of work has examined the mechanisms by which flowering plants correctly time their entry into the reproductive phase (the 'floral transition'). However, the corresponding mechanisms by which plants exit the reproductive phase remain relatively neglected. In this review, we identify four developmental processes that contribute to the end-of-flowering; floral arrest, inflorescence meristem arrest, inflorescence activation and 'vegetative transition'. We highlight that, due to the highly divergent nature of reproductive systems among flowering plants, these processes are differently important for end-of-flowering in different species. For each of these processes, we examine recent advances in understanding the regulatory mechanisms that govern the process, and how these mechanisms determine the timing of end-of-flowering. [ABSTRACT FROM AUTHOR]

• Whole-core multi-physics modelling framework developed. • New framework couples PARCS, RELAP, CTF and ENIGMA codes via the NEXUS platform. • Framework demonstrated via model of uprated Zion PWR with modern fuel assembly design. • Various uncontrolled RCCA bank withdrawal at power faults investigated with model. • Effects of prior load-following (extended reduced power operation) also examined. The increasing deployment of renewable energy sources and greater electrification of demand is requiring more frequent use of load following in pressurised water reactors (PWRs). A limiting aspect with respect to load following is the thermo-mechanical behaviour of the fuel. Hence a greater use of best-estimate multi-physics tools that can more accurately capture such behaviour during load following manoeuvres – in particular, extended reduced power operation (ERPO) – has become important in recent years. To this end, we have developed a coupled, whole-core analysis framework and demonstrated it with a new generic PWR model. The demonstration is for uncontrolled RCCA bank withdrawal at power (URWAP) faults following a period of ERPO, since such scenarios are often limiting with respect to fuel integrity. The coupled, whole-core analysis framework that was developed consists of the PARCS neutronics code, the RELAP and CTF thermal–hydraulics codes, the ENIGMA fuel performance code, and the NEXUS platform for whole-core fuel performance. The generic PWR model constructed is for a 1240 MWe plant with a modern core design (maximum assembly burnup of 51.0 GWd/tHM, cycle length of 16 months, and an average fuel residence time of 2.3 cycles per assembly). Previous work in the literature on URWAP faults has focused on coupled neutronics and thermal–hydraulics analysis, with fuel performance assessment and the effects of load following neglected. These shortcomings are therefore addressed here. From a fuel performance perspective no fuel was predicted to fail due to pellet-clad interaction (PCI). Of the remaining failure indicators, margin to clad yield stress was most limiting, although no failure was predicted in all cases under the scenarios considered. [ABSTRACT FROM AUTHOR]

Summary: Because plant cells do not migrate, cell division planes are crucial determinants of plant cellular architecture. In Arabidopsis roots, stringent control of cell divisions leads to a virtually invariant division pattern, including those that create new tissue layers. However, the mechanisms that control oriented cell divisions are hitherto poorly understood. Here, we reveal one such mechanism in which FEZ and SOMBRERO (SMB), two plant-specific NAC-domain transcription factors, control the delicately tuned reorientation and timing of cell division in a subset of stem cells. FEZ is expressed in root cap stem cells, where it promotes periclinal, root cap-forming cell divisions. In contrast, SMB negatively regulates FEZ activity, repressing stem cell-like divisions in the root cap daughter cells. FEZ becomes expressed in predivision stem cells, induces oriented cell division, and activates expression of its negative regulator, SMB, thus generating a feedback loop for controlled switches in cell division plane. [Copyright &y& Elsevier]

Background: The purpose of this study was to determine whether an implantable hemodynamic monitor (IHM) could be used to judge the response of pulmonary arterial hypertension (PAH) patients to changes in therapy. Methods: A prospective, non-randomized, multi-center study evaluated physical examination, functional class, echocardiography, brain natriuretic peptide (BNP) levels, exercise capacity assessed by 6-minute walk and cardiopulmonary exercise tests, and quality of life at baseline and at 12 weeks. IHM measurements were continuously available to clinicians between clinic visits. Based on a priori, pre-specified analyses, the relationships between hemodynamic values, PAH treatments and clinical parameters were tracked in an observational fashion. Results: Twenty-four PAH patients underwent IHM implantation prior to a change in PAH therapy. IHM data identified 13 of the 15 patients who improved their 6-minute walk distance by >30 m at 12 weeks (+48 ± 65 m, p < 0.05), whereas the others walked less (−78 ± 115 m, not statistically significant). In addition, peak Vo 2, BNP levels and Minnesota Living with Heart Failure Questionnaire scores only improved in the former group. The change in mean pulmonary artery pressure correlated with the change in 6-minute walk distance at 12 weeks (r = −0.71, p < 0.001). Device-related adverse events were comparable to those known to occur with a pacemaker-like device. Conclusions: Changes in ambulatory continuous hemodynamic measurements predicted changes in 6-minute walk distance after the start or addition of PAH therapy. The IHM also identified patients who had improved exercise tolerance, BNP levels and quality of life. The IHM appeared to be well tolerated and allowed rapid hemodynamic feedback between clinic visits. [Copyright &y& Elsevier]

: ObjectivesThis study examined the characteristics of continuously measured right ventricular (RV) hemodynamic information derived from an implantable hemodynamic monitor (IHM) in heart failure patients.: BackgroundHemodynamic monitoring might improve the day-to-day management of patients with chronic heart failure (CHF). Little is known about the characteristics of long-term hemodynamic information in patients with CHF or how such information relates to meaningful clinical events.: MethodsThirty-two patients with CHF received a permanent RV IHM system similar to a single-lead pacemaker. Right ventricular systolic and diastolic pressures, heart rate, and pressure derivatives were continuously measured for nine months without using the data for clinical decision-making or management of patients. Data were then made available to clinical providers, and the patients were followed up for 17 months. Pressure characteristics during optimal volume, clinically determined volume-overload exacerbations, and volume depletion events were examined. The effect of IHM on hospitalizations was examined using the patients’ historical controls.: ResultsLong-term RV pressure measurements had either marked variability or minimal time-related changes. During 36 volume-overload events, RV systolic pressures increased by 25 ± 4% (p < 0.05) and heart rate increased by 11 ± 2% (p < 0.05). Pressure increases occurred in 9 of 12 events 4 ± 2 days before the exacerbations requiring hospitalization. Hospitalizations before using IHM data for clinical management averaged 1.08 per patient year and decreased to 0.47 per patient-year (57% reduction, p < 0.01) after hemodynamic data were used.: ConclusionsLong-term ambulatory pressure measurements from an IHM may be helpful in guiding day-to-day clinical management, with a potentially favorable impact on CHF hospitalizations. [Copyright &y& Elsevier]