Spectral ecophysiology: hyperspectral pressure-volume curves to estimate leaf turgor loss.

Turgor loss point (TLP) is an important proxy for plant drought tolerance, species habitat suitability, and drought-induced plant mortality risk. Thus, TLP serves as a critical tool for evaluating climate change impacts on plants, making it imperative to develop high-throughput and in situ methods to measure TLP. We developed hyperspectral pressure-volume curves (PV curves) to estimate TLP using leaf spectral reflectance. We used partial least square regression models to estimate water potential (Ψ) and relative water content (RWC) for two species, Frangula caroliniana and Magnolia grandiflora. RWC and Ψ's model for each species had R2 ≥ 0.7 and %RMSE = 7-10. We constructed PV curves with model estimates and compared the accuracy of directly measured and spectra-predicted TLP. Our findings indicate that leaf spectral measurements are an alternative method for estimating TLP. F. caroliniana TLP's values were -1.62 ± 0.15 (means ± SD) and -1.62 ± 0.34 MPa for observed and reflectance predicted, respectively (P > 0.05), while M. grandiflora were -1.78 ± 0.34 and -1.66 ± 0.41 MPa (P > 0.05). The estimation of TLP through leaf reflectance-based PV curves opens a broad range of possibilities for future research aimed at understanding and monitoring plant water relations on a large scale with spectral ecophysiology.

Hyperspectral signals in the soil: Plant-soil hydraulic connection and disequilibrium as mechanisms of drought tolerance and rapid recovery.

Predicting soil water status remotely is appealing due to its low cost and large-scale application. During drought, plants can disconnect from the soil, causing disequilibrium between soil and plant water potentials at pre-dawn. The impact of this disequilibrium on plant drought response and recovery is not well understood, potentially complicating soil water status predictions from plant spectral reflectance. This study aimed to quantify drought-induced disequilibrium, evaluate plant responses and recovery, and determine the potential for predicting soil water status from plant spectral reflectance. Two species were tested: sweet corn (Zea mays), which disconnected from the soil during intense drought, and peanut (Arachis hypogaea), which did not. Sweet corn's hydraulic disconnection led to an extended 'hydrated' phase, but its recovery was slower than peanut's, which remained connected to the soil even at lower water potentials (-5 MPa). Leaf hyperspectral reflectance successfully predicted the soil water status of peanut consistently, but only until disequilibrium occurred in sweet corn. Our results reveal different hydraulic strategies for plants coping with extreme drought and provide the first example of using spectral reflectance to quantify rhizosphere water status, emphasizing the need for species-specific considerations in soil water status predictions from canopy reflectance.

Evidence of combined flower thermal and drought vulnerabilities portends reproductive failure under hotter-drought conditions.

Despite the abundant evidence of impairments to plant performance and survival under hotter-drought conditions, little is known about the vulnerability of reproductive organs to climate extremes. Here, by conducting a comparative analysis between flowers and leaves, we investigated how variations in key morphophysiological traits related to carbon and water economics can explain the differential vulnerabilities to heat and drought among these functionally diverse organs. Due to their lower construction costs, despite having a higher water storage capacity, flowers were more prone to turgor loss (higher turgor loss point; ΨTLP) than leaves, thus evidencing a trade-off between carbon investment and drought tolerance in reproductive organs. Importantly, the higher ΨTLP of flowers also resulted in narrow turgor safety margins (TSM). Moreover, compared to leaves, the cuticle of flowers had an overall higher thermal vulnerability, which also resulted in low leakage safety margins (LSM). As a result, the combination of low TSMs and LSMs may have negative impacts on reproduction success since they strongly influenced the time to turgor loss under simulated hotter-drought conditions. Overall, our results improve the knowledge of unexplored aspects of flower structure and function and highlight likely threats to successful plant reproduction in a warmer and drier world.

Hydraulic variability of tropical forests is largely independent of water availability.

Tropical rainforest woody plants have been thought to have uniformly low resistance to hydraulic failure and to function near the edge of their hydraulic safety margin (HSM), making these ecosystems vulnerable to drought; however, this may not be the case. Using data collected at 30 tropical forest sites for three key traits associated with drought tolerance, we show that site-level hydraulic diversity of leaf turgor loss point, resistance to embolism (P50 ), and HSMs is high across tropical forests and largely independent of water availability. Species with high HSMs (>1 MPa) and low P50 values (< -2 MPa) are common across the wet and dry tropics. This high site-level hydraulic diversity, largely decoupled from water stress, could influence which species are favoured and become dominant under a drying climate. High hydraulic diversity could also make these ecosystems more resilient to variable rainfall regimes.

Rooting depth and xylem vulnerability are independent woody plant traits jointly selected by aridity, seasonality, and water table depth.

Evolutionary radiations of woody taxa within arid environments were made possible by multiple trait innovations including deep roots and embolism-resistant xylem, but little is known about how these traits have coevolved across the phylogeny of woody plants or how they jointly influence the distribution of species. We synthesized global trait and vegetation plot datasets to examine how rooting depth and xylem vulnerability across 188 woody plant species interact with aridity, precipitation seasonality, and water table depth to influence species occurrence probabilities across all biomes. Xylem resistance to embolism and rooting depth are independent woody plant traits that do not exhibit an interspecific trade-off. Resistant xylem and deep roots increase occurrence probabilities in arid, seasonal climates over deep water tables. Resistant xylem and shallow roots increase occurrence probabilities in arid, nonseasonal climates over deep water tables. Vulnerable xylem and deep roots increase occurrence probabilities in arid, nonseasonal climates over shallow water tables. Lastly, vulnerable xylem and shallow roots increase occurrence probabilities in humid climates. Each combination of trait values optimizes occurrence probabilities in unique environmental conditions. Responses of deeply rooted vegetation may be buffered if evaporative demand changes faster than water table depth under climate change.

A bitter future for coffee production? Physiological traits associated with yield reveal high vulnerability to hydraulic failure in Coffea canephora.

The increase in frequency and intensity of drought events have hampered coffee production in the already threatened Amazon region, yet little is known about key aspects underlying the variability in yield potential across genotypes, nor to what extent higher productivity is linked to reduced drought tolerance. Here we explored how variations in morphoanatomical and physiological leaf traits can explain differences in yield and vulnerability to embolism in 11 Coffea canephora genotypes cultivated in the Western Amazon. The remarkable variation in coffee yield across genotypes was tightly related to differences in their carbon assimilation and water transport capacities, revealing a diffusive limitation to photosynthesis linked by hydraulic constraints. Although a clear trade-off between water transport efficiency and safety was not detected, all the studied genotypes operated in a narrow and/or negative hydraulic safety margin, suggesting a high vulnerability to leaf hydraulic failure (HF), especially on the most productive genotypes. Modelling exercises revealed that variations in HF across genotypes were mainly associated with differences in leaf water vapour leakage when stomata are closed, reflecting contrasting growth strategies. Overall, our results provide a new perspective on the challenges of sustaining coffee production in the Amazon region under a drier and warmer climate.

Aridity-dependent sequence of water potentials for stomatal closure and hydraulic dysfunctions in woody plants.

The sequence of physiological events during drought strongly impacts plants' overall performance. Here, we synthesized the global data of stomatal and hydraulic traits in leaves and stems of 202 woody species to evaluate variations in the water potentials for key physiological events and their sequence along the climatic gradient. We found that the seasonal minimum water potential, turgor loss point, stomatal closure point, and leaf and stem xylem vulnerability to embolism were intercorrelated and decreased with aridity, indicating that water stress drives trait co-selection. In xeric regions, the seasonal minimum water potential occurred at lower water potential than turgor loss point, and the subsequent stomatal closure delayed embolism formation. In mesic regions, however, the seasonal minimum water potential did not pose a threat to the physiological functions, and stomatal closure occurred even at slightly more negative water potential than embolism. Our study demonstrates that the sequence of water potentials for physiological dysfunctions of woody plants varies with aridity, that is, xeric species adopt a more conservative sequence to prevent severe tissue damage through tighter stomatal regulation (isohydric strategy) and higher embolism resistance, while mesic species adopt a riskier sequence via looser stomatal regulation (anisohydric strategy) to maximize carbon uptake at the cost of hydraulic safety. Integrating both aridity-dependent sequence of water potentials for physiological dysfunctions and gap between these key traits into the hydraulic framework of process-based vegetation models would improve the prediction of woody plants' responses to drought under global climate change.

Leaf habit affects the distribution of drought sensitivity but not water transport efficiency in the tropics.

Considering the global intensification of aridity in tropical biomes due to climate change, we need to understand what shapes the distribution of drought sensitivity in tropical plants. We conducted a pantropical data synthesis representing 1117 species to test whether xylem-specific hydraulic conductivity (KS ), water potential at leaf turgor loss (ΨTLP ) and water potential at 50% loss of KS (ΨP50 ) varied along climate gradients. The ΨTLP and ΨP50 increased with climatic moisture only for evergreen species, but KS did not. Species with high ΨTLP and ΨP50 values were associated with both dry and wet environments. However, drought-deciduous species showed high ΨTLP and ΨP50 values regardless of water availability, whereas evergreen species only in wet environments. All three traits showed a weak phylogenetic signal and a short half-life. These results suggest strong environmental controls on trait variance, which in turn is modulated by leaf habit along climatic moisture gradients in the tropics.

Survival and Scoliosis Following Resection of Chest Wall Tumors in Children and Adolescents: A Single-center Retrospective Analysis.

OBJECTIVE: We reviewed our experience with pediatric chest wall tumors (CWTs) to identify variables associated with survival, scoliosis development, and need for corrective scoliosis surgery. BACKGROUND: Chest wall neoplasms in children or adolescents are rare. Consequently, there are few large series that detail survival or quality of life indicators, like scoliosis. METHODS: Medical records were reviewed for all chest wall resections for primary and metastatic CWT performed from October 1, 1986 to September 30, 2016 on patients 21 years or younger at diagnosis. Kaplan-Meier distributions were compared using the log-rank test. Variables correlated with survival, scoliosis development, or need for corrective surgeries were analyzed using competing-risk analysis. RESULTS: Seventy-six cases [57 (75%) primary, 19 (25%) metastatic] were identified. Median age at diagnosis was 15.6 years (range: 0.5-21 years). Tumor types were Ewing sarcoma family tumors (54%), other soft tissue sarcomas (21%), osteosarcoma (11%), rhabdomyosarcoma (7%), and other (8%). A median of 3 (range: 1-5) contiguous ribs were resected. Surgical reconstruction included composite Marlex mesh and methyl-methacrylate, Gore-Tex, or primary closure in 57%, 28%, and 14% of procedures, respectively. Overall 5-year survival was 61% (95% confidence interval: 50%-75%). Scoliosis developed in 19 (25%) patients; 6 patients required corrective surgery. Variables associated with overall survival were the presence of metastatic disease at diagnosis, and whether the chest tumor itself was a primary or metastatic lesion. Younger age at chest wall resection was associated with the need for corrective surgery in patients who developed scoliosis. CONCLUSIONS: Among pediatric and adolescent patients with CWTs, survival depends primarily on the presence of metastases. Age, type of chest wall reconstruction, and tumor size are not associated with scoliosis development. Among patients who develop scoliosis, younger patients are more likely to require corrective surgery.

A thin line between life and death: Radial sap flux failure signals trajectory to tree mortality.

This article comments on: Seeking the "point of no return" in the sequence of events leading to mortality of mature trees.

Addition of chemotherapy to local therapy in women aged 70 years or older with triple-negative breast cancer: a propensity-matched analysis.

BACKGROUND: There is a scarcity of data exploring the benefits of adjuvant or neoadjuvant chemotherapy in the treatment of breast cancer in older women. We aimed to explore the effect of adding chemotherapy to local therapy on overall survival in older women with triple-negative breast cancer. METHODS: For this propensity-matched analysis, we used data from the National Cancer Database, a joint project of the Commission on Cancer of the American College of Surgeons and the American Cancer Society. We included data from women aged 70 years or older with surgically treated, American Joint Committee on Cancer (AJCC) Stage I-III invasive triple-negative breast cancer diagnosed from 2004 to 2014. Patients with T1aN0M0 disease and those with incomplete data on oestrogen receptor status, progesterone receptor status, or HER2 status were excluded. To reduce bias, patients were subdivided into three groups: those who were recommended chemotherapy but did not receive it; those who received chemotherapy; and those for whom chemotherapy was not recommended and not given. The primary outcome was overall survival. Multivariate Cox regression analysis and propensity score matching were done to minimise bias. FINDINGS: Between Jan 1, 2004, and Dec, 31, 2014, 16 062 women with triple-negative breast cancer in the database met the inclusion criteria for this analysis. Median follow-up was 38·3 months (IQR 20·7-46·1, range 0-138·0; 95% CI 37·8-38·7). Collectively, the 5-year overall survival estimate of the 16 062 patients in the study cohort was 62·3% (95% CI 59·7-64·4). 5-year estimated overall survival was 68·5% (95% CI 66·4-70·6) for patients receiving chemotherapy, 61·1% (59·0-63·2) for patients recommended but not given chemotherapy, and 53·7% (51·8-55·8) for patients not recommended chemotherapy and not given chemotherapy (pooled log rank p<0·0001). Multivariate Cox regression analysis of a propensity score-matched sample comparing those who received chemotherapy with those who were recommended but not given chemotherapy (n=1884 matched pairs) identified improved overall survival with chemotherapy (hazard ratio [HR] 0·69 [95% CI 0·60-0·80]; p<0·0001). After stratifying the propensity score matching sample, this benefit persisted for node-negative women (HR 0·80 [95% CI 0·66-0·97]; p=0·007), node-positive women (0·76 [0·64-0·91]; p=0·006), and those with a comorbidity score greater than 0 (HR 0·74 [95% CI 0·59-0·94]; p=0·013). INTERPRETATION: These data support consideration of chemotherapy in the treatment of women aged 70 years or older with triple-negative breast cancer. FUNDING: None.

Understanding of Contemporary Regional Sea-Level Change and the Implications for the Future.

Global sea level provides an important indicator of the state of the warming climate, but changes in regional sea level are most relevant for coastal communities around the world. With improvements to the sea-level observing system, the knowledge of regional sea-level change has advanced dramatically in recent years. Satellite measurements coupled with in situ observations have allowed for comprehensive study and improved understanding of the diverse set of drivers that lead to variations in sea level in space and time. Despite the advances, gaps in the understanding of contemporary sea-level change remain and inhibit the ability to predict how the relevant processes may lead to future change. These gaps arise in part due to the complexity of the linkages between the drivers of sea-level change. Here we review the individual processes which lead to sea-level change and then describe how they combine and vary regionally. The intent of the paper is to provide an overview of the current state of understanding of the processes that cause regional sea-level change and to identify and discuss limitations and uncertainty in our understanding of these processes. Areas where the lack of understanding or gaps in knowledge inhibit the ability to provide the needed information for comprehensive planning efforts are of particular focus. Finally, a goal of this paper is to highlight the role of the expanded sea-level observation network-particularly as related to satellite observations-in the improved scientific understanding of the contributors to regional sea-level change.

Uplift and seismicity driven by groundwater depletion in central California.

Groundwater use in California's San Joaquin Valley exceeds replenishment of the aquifer, leading to substantial diminution of this resource and rapid subsidence of the valley floor. The volume of groundwater lost over the past century and a half also represents a substantial reduction in mass and a large-scale unburdening of the lithosphere, with significant but unexplored potential impacts on crustal deformation and seismicity. Here we use vertical global positioning system measurements to show that a broad zone of rock uplift of up to 1-3 mm per year surrounds the southern San Joaquin Valley. The observed uplift matches well with predicted flexure from a simple elastic model of current rates of water-storage loss, most of which is caused by groundwater depletion. The height of the adjacent central Coast Ranges and the Sierra Nevada is strongly seasonal and peaks during the dry late summer and autumn, out of phase with uplift of the valley floor during wetter months. Our results suggest that long-term and late-summer flexural uplift of the Coast Ranges reduce the effective normal stress resolved on the San Andreas Fault. This process brings the fault closer to failure, thereby providing a viable mechanism for observed seasonality in microseismicity at Parkfield and potentially affecting long-term seismicity rates for fault systems adjacent to the valley. We also infer that the observed contemporary uplift of the southern Sierra Nevada previously attributed to tectonic or mantle-derived forces is partly a consequence of human-caused groundwater depletion.

Dead or dying? Quantifying the point of no return from hydraulic failure in drought-induced tree mortality.

Determining physiological mechanisms and thresholds for climate-driven tree die-off could help improve global predictions of future terrestrial carbon sinks. We directly tested for the lethal threshold in hydraulic failure - an inability to move water due to drought-induced xylem embolism - in a pine sapling experiment. In a glasshouse experiment, we exposed loblolly pine (Pinus taeda) saplings (n = 83) to drought-induced water stress ranging from mild to lethal. Before rewatering to relieve drought stress, we measured native hydraulic conductivity and foliar color change. We monitored all measured individuals for survival or mortality. We found a lethal threshold at 80% loss of hydraulic conductivity - a point of hydraulic failure beyond which it is more likely trees will die, than survive, and describe mortality risk across all levels of water stress. Foliar color changes lagged behind hydraulic failure - best predicting when trees had been dead for some time, rather than when they were dying. Our direct measurement of native conductivity, while monitoring the same individuals for survival or mortality, quantifies a continuous probability of mortality risk from hydraulic failure. Predicting tree die-off events and understanding the mechanism involved requires knowledge not only of when trees are dead, but when they begin dying - having passed the point of no return.

Treatment and outcome of adult-onset neuroblastoma.

Adult-onset neuroblastoma is rare and little is known about its biology and clinical course. There is no established therapy for adult-onset neuroblastoma. Anti-GD2 immunotherapy is now standard therapy in children with high-risk neuroblastoma; however, its use has not been reported in adults. Forty-four adults (18-71 years old) diagnosed with neuroblastoma between 1979 and 2015 were treated at Memorial Sloan Kettering Cancer Center. Five, 1, 5 and 33 patients had INSS stage 1, 2, 3 and 4 diseases, respectively. Genetic abnormalities included somatic ATRX (58%) and ALK mutations (42%) but not MYCN-amplification. In the 11 patients with locoregional disease, 10-year progression-free (PFS) and overall survival (OS) was 35.4 ± 16.1% and 61.4 ± 15.3%, respectively. Among 33 adults with stage 4 neuroblastoma, 7 (21%) achieved complete response (CR) after induction chemotherapy and/or surgery. Seven patients with primary refractory neuroblastoma (all with osteomedullary but no soft tissue disease) received anti-GD2 antibodies, mouse or humanized 3F8. Antibody-related adverse events were similar to those in children, response rate being 71.4%. In patients with stage 4 disease at diagnosis, 5-year PFS was 9.7± 5.3% and most patients who were alive with disease at 5 years died of neuroblastoma over the next 5 years, 10-year OS being only 19.0 ± 8.2%. Patients who achieved CR after induction had superior PFS and OS (p = 0.006, p = 0.031, respectively). Adult-onset neuroblastoma appeared to have different biology from pediatric or adolescent NB, and poorer outcome. Complete disease control appeared to improve long-term survival. Anti-GD2 immunotherapy was well tolerated and might be beneficial.

Intracranial metastasis in fibrolamellar hepatocellular carcinoma.

Fibrolamellar hepatocellular carcinoma (FLHCC) is a rare liver malignancy in adolescents and young adults. Surgery is the mainstay of therapy for primary and metastatic disease. Most patients relapse, with development of both local and distant metastases. Brain metastases from solid tumors are rare in the pediatric and young adult population. Here, we document three patients with brain metastases from FLHCC, confirmed by histology and molecular characterization of the chimeric fusion DNAJB1-PRKACA, each necessitating neurosurgical intervention. These observations highlight the ability of FLHCC to metastasize to the brain and suggest the need for surveillance neuroimaging for patients with advanced-stage disease.

Evaluation of Nursing Documentation Completion of Stroke Patients in the Emergency Department: A Pre-Post Analysis Using Flowsheet Templates and Clinical Decision Support.

The primary aim of this performance improvement project was to determine whether the electronic health record implementation of stroke-specific nursing documentation flowsheet templates and clinical decision support alerts improved the nursing documentation of eligible stroke patients in seven stroke-certified emergency departments. Two system enhancements were introduced into the electronic record in an effort to improve nursing documentation: disease-specific documentation flowsheets and clinical decision support alerts. Using a pre-post design, project measures included six stroke management goals as defined by the National Institute of Neurological Disorders and Stroke and three clinical decision support measures based on entry of orders used to trigger documentation reminders for nursing: (1) the National Institutes of Health's Stroke Scale, (2) neurological checks, and (3) dysphagia screening. Data were reviewed 6 months prior (n = 2293) and 6 months following the intervention (n = 2588). Fisher exact test was used for statistical analysis. Statistical significance was found for documentation of five of the six stroke management goals, although effect sizes were small. Customizing flowsheets to meet the needs of nursing workflow showed improvement in the completion of documentation. The effects of the decision support alerts on the completeness of nursing documentation were not statistically significant (likely due to lack of order entry). For example, an order for the National Institutes of Health Stroke Scale was entered only 10.7% of the time, which meant no alert would fire for nursing in the postintervention group. Future work should focus on decision support alerts that trigger reminders for clinicians to place relevant orders for this population.

Climate-induced tree-mortality pulses are obscured by broad-scale and long-term greening.

Vegetation greening has been suggested to be a dominant trend over recent decades, but severe pulses of tree mortality in forests after droughts and heatwaves have also been extensively reported. These observations raise the question of to what extent the observed severe pulses of tree mortality induced by climate could affect overall vegetation greenness across spatial grains and temporal extents. To address this issue, here we analyse three satellite-based datasets of detrended growing-season normalized difference vegetation index (NDVIGS) with spatial resolutions ranging from 30 m to 8 km for 1,303 field-documented sites experiencing severe drought- or heat-induced tree-mortality events around the globe. We find that severe tree-mortality events have distinctive but localized imprints on vegetation greenness over annual timescales, which are obscured by broad-scale and long-term greening. Specifically, although anomalies in NDVIGS (ΔNDVI) are negative during tree-mortality years, this reduction diminishes at coarser spatial resolutions (that is, 250 m and 8 km). Notably, tree-mortality-induced reductions in NDVIGS (|ΔNDVI|) at 30-m resolution are negatively related to native plant species richness and forest height, whereas topographic heterogeneity is the major factor affecting ΔNDVI differences across various spatial grain sizes. Over time periods of a decade or longer, greening consistently dominates all spatial resolutions. The findings underscore the fundamental importance of spatio-temporal scales for cohesively understanding the effects of climate change on forest productivity and tree mortality under both gradual and abrupt changes.

Cholecystoappendiceal Fistula From Appendiceal Adenocarcinoma Requiring a Right Hemicolectomy With Cytoreduction and Hyperthermic Intraperitoneal Chemotherapy.

Bilioenteric fistulae are rare and difficult to manage complications of chronic cholecystitis. While cholecystoduodenal and cholecystocolic fistulae are more common, a cholecystoappendiceal fistula is an extremely rare finding. We report the presentation and operative management of a 59-year-old male with cholecystoappendiceal fistula and associated abscess in the gallbladder fossa. The patient was appropriately resuscitated, the abscess drained by interventional radiology, and after a complete workup, underwent a laparoscopic appendectomy and cholecystectomy. Pathology revealed moderately differentiated appendiceal adenocarcinoma requiring a right hemicolectomy with cytoreduction and hyperthermic intraperitoneal chemotherapy (HIPEC). He has recovered well postoperatively with no complications. This case highlights the importance of having a very high index of suspicion for underlying malignancy when managing a fistula of any kind. To the best of our understanding, this is only the second reported case of a cholecystoappendiceal fistula.