Temperature response measurements from eucalypts give insight into the impact of Australian isoprene emissions on air quality in 2050

Predicting future air quality in Australian cities dominated by eucalypt emissions requires an understanding of their emission potentials in a warmer climate. Here we measure the temperature response in isoprene emissions from saplings of four different Eucalyptus species grown under current and future average summertime temperature conditions. The future conditions represent a 2050 climate under Representative Concentration Pathway 8.5, with average daytime temperatures of 294.5 K. Ramping the temperature from 293 to 328 K resulted in these eucalypts emitting isoprene at temperatures 4–9 K higher than the default maximum emission temperature in the Model of Emissions of Gases and Aerosols from Nature (MEGAN). New basal emission rate measurements were obtained at the standard conditions of 303 K leaf temperature and 1000 µmol m−2 s−1 photosynthetically active radiation and converted into landscape emission factors. We applied the eucalypt temperature responses and emission factors to Australian trees within MEGAN and ran the CSIRO Chemical Transport Model for three summertime campaigns in Australia. Compared to the default model, the new temperature responses resulted in less isoprene emission in the morning and more during hot afternoons, improving the statistical fit of modelled to observed ambient isoprene. Compared to current conditions, an additional 2 ppb of isoprene is predicted in 2050, causing hourly increases up to 21 ppb of ozone and 24-hourly increases of 0.4 µg m−3 of aerosol in Sydney. A 550 ppm CO2 atmosphere in 2050 mitigates these peak Sydney ozone mixing ratios by 4 ppb. Nevertheless, these forecasted increases in ozone are up to one-fifth of the hourly Australian air quality limit, suggesting that anthropogenic NOx should be further reduced to maintain healthy air quality in future

Extreme heat increases stomatal conductance and drought-induced mortality risk in vulnerable plant species

Tree mortality during global-change-type drought is usually attributed to xylem dysfunction, but as climate change increases the frequency of extreme heat events, it is necessary to better understand the interactive role of heat stress. We hypothesized that some drought-stressed plants paradoxically open stomata in heatwaves to prevent leaves from critically overheating. We experimentally imposed heat (>40°C) and drought stress onto 20 broadleaf evergreen tree/shrub species in a glasshouse study. Most well-watered plants avoided lethal overheating, but drought exacerbated thermal damage during heatwaves. Thermal safety margins (TSM) quantifying the difference between leaf surface temperature and leaf critical temperature, where photosynthesis is disrupted, identified species vulnerability to heatwaves. Several mechanisms contributed to high heat tolerance and avoidance of damaging leaf temperatures—small leaf size, low leaf osmotic potential, high leaf mass per area (i.e., thick, dense leaves), high transpirational capacity, and access to water. Water-stressed plants had smaller TSM, greater crown dieback, and a fundamentally different stomatal heatwave response relative to well-watered plants. On average, well-watered plants closed stomata and decreased stomatal conductance (gs) during the heatwave, but droughted plants did not. Plant species with low gs, either due to isohydric stomatal behavior under water deficit or inherently low transpirational capacity, opened stomata and increased gs under high temperatures. The current paradigm maintains that stomata close before hydraulic thresholds are surpassed, but our results suggest that isohydric species may dramatically increase gs (over sixfold increases) even past their leaf turgor loss point. By actively increasing water loss at high temperatures, plants can be driven toward mortality thresholds more rapidly than has been previously recognized. The inclusion of TSM and responses to heat stress could improve our ability to predict the vulnerability of different tree species to future droughts

The impact of a history of child abuse on cognitive performance:a cross-sectional study in older patients with a depressive, anxiety, or somatic symptom disorder

Background: Child abuse is a major global burden with an enduring negative impact on mental and physical health. A history of child abuse is consistently associated with worse cognitive performance among adults; data in older age groups are inconclusive. Since affective symptoms and cognitive functioning are interrelated among older persons, a synergistic effect can be assumed in patients with affective symptoms who also have suffered from child abuse. This study examines the association between a history of child abuse and cognitive performance in such patients. Methods: Cross-sectional data were collected from the ‘Routine Outcome Monitoring for Geriatric Psychiatry & Science’ project, including 179 older adults (age 60–88 years) with either a unipolar depressive, any anxiety, or somatic symptom disorder referred to specialized geriatric mental health care. A history of physical, sexual, and psychological abuse, and emotional neglect was assessed with a structured interview. Cognitive functioning was measured with three paper and pencils tests (10-words verbal memory test, Stroop Colour-Word test, Digit Span) and four tests from the computerized Cogstate Test Battery (Detection Test, Identification Test, One Card Learning Test, One Back Test). The association between a history of child abuse and cognitive performance was examined by multiple linear regression analyses adjusted for covariates. Results: Principal component analyses of nine cognitive parameters revealed four cognitive domains, i.e., visual-verbal memory, psychomotor speed, working memory and interference control. A history of child abuse was not associated with any of these cognitive domains. However, when looking at the specific types of child abuse separately, a history of physical abuse and emotional neglect were associated with poorer interference control. A history of physical abuse was additionally associated with better visual-verbal memory. Conclusions: The association between a history of child abuse and cognitive performance differs between the different types of abuse. A history of physical abuse might particularly be a key determinant of cognitive performance in older adults with a depressive, anxiety, or somatic symptom disorder. Future studies on the impact of these disorders on the onset of dementia should take child abuse into account. Trial registration: ROM-GPS is registered at the Dutch Trial Register (NL6704 at www.trialregister.nl)

Increasing aridity will not offset CO2_{2} fertilization in fast-growing eucalypts with access to deep soil water

Rising atmospheric [CO$_{2}$] (C$_{a}$) generally enhances tree growth if nutrients are not limiting. However, reduced water availability and elevated evaporative demand may offset such fertilization. Trees with access to deep soil water may be able to mitigate such stresses and respond more positively to C$_{a}$. Here, we sought to evaluate how increased vapor pressure deficit and reduced precipitation are likely to modify the impact of elevated C$_{a}$ (eC$_{a}$) on tree productivity in an Australian Eucalyptus saligna Sm. plantation with access to deep soil water. We parameterized a forest growth simulation model (GOTILWA+) using data from two field experiments on E. saligna: a 2‐year whole‐tree chamber experiment with factorial C$_{a}$ (ambient =380, elevated =620 μmol mol$^{-1}$) and watering treatments, and a 10‐year stand‐scale irrigation experiment. Model evaluation showed that GOTILWA+ can capture the responses of canopy C uptake to (1) rising vapor pressure deficit (D) under both C$_{a}$ treatments; (2) alterations in tree water uptake from shallow and deep soil layers during soil dry‐down; and (3) the impact of irrigation on tree growth. Simulations suggest that increasing C$_{a}$ up to 700 μmol mol$^{-1}$ alone would result in a 33% increase in annual gross primary production (GPP) and a 62% increase in biomass over 10 years. However, a combined 48% increase in D and a 20% reduction in precipitation would halve these values. Our simulations identify high D conditions as a key limiting factor for GPP. They also suggest that rising Ca will compensate for increasing aridity limitations in E. saligna trees with access to deep soil water under non‐nutrient limiting conditions, thereby reducing the negative impacts of global warming upon this eucalypt species. Simulation models not accounting for water sources available to deep‐rooting trees are likely to overestimate aridity impacts on forest productivity and C stocks

Sub-dekahertz ultraviolet spectroscopy of 199Hg+

Using a laser that is frequency-locked to a Fabry-Perot etalon of high finesse and stability, we probe the 5d10 6s 2S_1/2 (F=0) - 5d9 6s 2D_5/2 (F=2) Delta-m_F = 0 electric-quadrupole transition of a single laser-cooled 199Hg+ ion stored in a cryogenic radio-frequency ion trap. We observe Fourier-transform limited linewidths as narrow as 6.7 Hz at 282 nm (1.06 X 10^15 Hz), yielding a line Q = 1.6 X 10^14. We perform a preliminary measurement of the 5d9 6s2 2D_5/2 electric-quadrupole shift due to interaction with the static fields of the trap, and discuss the implications for future trapped-ion optical frequency standards.Comment: 4 pages, 4 figures, submitted for publicatio

Mapping the climate risk to urban forests at city scale

Climate change represents a threat to the performance and persistence of urban forests and the multiple benefits they provide to city dwellers. Here, we use a novel approach to identify species and areas at high risk of climate change using the city of Melbourne, Australia, as a case study. We derive a safety margin, calculated based on climatic tolerance to two extreme climate variables (maximum temperature of the warmest month, MTWM; precipitation of the driest quarter, PDQ), for 474 tree species recorded in Melbourne for baseline (average for 2011–2020) and future (2041–2070) climatic conditions. For MTWM, 218 species (46%) are exceeding baseline climatic safety margins; this number is predicted to increase to 322 species (68%) by 2055 under the Shared Socioeconomic Pathway 5–8.5. For PDQ, 255 and 257 species (54%) are identified as at risk for baseline and future climates, respectively. Using georeferenced locations of trees and high-resolution climate data, we map spatial patterns in climate risk, showing high risk areas across the city. We demonstrate how using urban tree inventories and climate risk metrics can aid in the identification of vulnerable species and locations at high climate risk to prioritise areas for monitoring and assist urban planning

Chicken IgL gene rearrangement involves deletion of a circular episome and addition of single nonrandom nucleotides to both coding segments

Chicken immunoglobulin light chain (IgL) gene rearrangement has been characterized. Rearrangement of the single variable (VL) segment with the single joining (JL) segment within the chicken IgL locus results in the deletion of the DNA between VL and JL from the genome. This deletion is accomplished by a molecular mechanism in which a precise joining of the IgL recombination signal sequences leads to the formation of a circular episomal element. The circular episome is an unstable genetic element that fails to be propagated during B cell development. Evidence was obtained that the formation of the circular episome is accompanied by the addition of a single nonrandom base to both the VL and JL coding segments. The subsequent joining of the VL and JL segments appears to occur at random, as we observed at least 25 unique V-J junction sequences, 11 of which are out-of-frame. A novel recombination mechanism that accounts for the observed features of chicken IgL gene rearrangement is discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28019/1/0000455.pd

TRY plant trait database - enhanced coverage and open access

Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

DAMP production by human islets under low oxygen and nutrients in the presence or absence of an immunoisolating-capsule and necrostatin-1

In between the period of transplantation and revascularization, pancreatic islets are exposed to low-oxygen and low-nutrient conditions. In the present study we mimicked those conditions in vitro to study the involvement of different cell death processes, release of danger-associated molecular patterns (DAMP), and associated in vitro immune activation. Under low-oxygen and low-nutrient conditions, apoptosis, autophagy and necroptosis occur in human islets. Necroptosis is responsible for DAMP-release such as dsDNA, uric acid, and HMGB1. The sensors of the innate immune system able to recognize these DAMPs are mainly TLR, NOD receptors, and C-type lectins. By using cell-lines with a non-functional adaptor molecule MyD88, we were able to show that the islet-derived DAMPs signal mainly via TLR. Immunoisolation in immunoprotective membranes reduced DAMP release and immune activation via retention of the relative large DAMPs in the capsules. Another effective strategy was suppressing necroptosis using the inhibitor nec-1. Although the effect on cell-survival was minor, nec-1 was able to reduce the release of HMGB1 and its associated immune activation. Our data demonstrate that in the immediate post-transplant period islets release DAMPs that in vitro enhance responses of innate immune cells. DAMP release can be reduced in vitro by immunoisolation or intervention with nec-1

Nocturnal plant respiration is under strong non-temperature control

This is the final version. Available on open access from Nature Research via the DOI in this recordData availability: The leaf respiration data measured as part of this study and collected from the literature together with annual gridded JULES output generated in simulations of this study are available at https://doi.org/10.5281/zenodo.7037530. WFDEI meteorological forcing data is available at the DATAGURU website for climate-related data at Lund University (https://DATAGURU.lu.se, then go to “Explore available datasets”). This allows extraction of data from the global domain, a user-defined grid box or region for a specified time interval. Ftp downloads are possible via the unix/linux command line, site = ftp.iiasa.ac.at, username = rfdata and password = forceDATA, this takes the user to the WATCH Forcing DATA files, then switch to the WFDEI directory using: ‘cd WFDEI’. The /WFDEI directory includes files listing grid box elevations and locations Annual CO2 concentrations are available at https://gml.noaa.gov/ccgg/trends/gl_data.html Source data are provided with this paper.Code availability: Python code for data analysis is available under https://doi.org/10.5281/zenodo.7037530. This study uses JULES, two branches of JULES-vn5.2. https://code.metoffice.gov.uk/trac/jules/browser/main/branches/dev/linamercado/r14338_circadian at revision 22682 for TDQ10 simulations and https://code.metoffice.gov.uk/trac/jules/browser/main/branches/dev/douglasclark/vn5.2_diurnal_resp at revision 22681 for simulations with constant Q10 which are available on the Met Office Science Repository System (MOSRS; https://code.metoffice.gov.uk/trac/jules; registration required https://jules.jchmr.org/content/getting-started). Simulations were performed using Rose suites u-ce999 (new formulation) and u-ce859 for simulations with constant Q10, and u-bs101 (with new formulation) and u-ce767 for simulations with TDQ10 also available through MOSRS.Most biological rates depend on the rate of respiration. Temperature variation is typically considered the main driver of daily plant respiration rates, assuming a constant daily respiration rate at a set temperature. Here, we show empirical data from 31 species from temperate and tropical biomes to demonstrate that the rate of plant respiration at a constant temperature decreases monotonically with time through the night, on average by 25% after 8 h of darkness. Temperature controls less than half of the total nocturnal variation in respiration. A new universal formulation is developed to model and understand nocturnal plant respiration, combining the nocturnal decrease in the rate of plant respiration at constant temperature with the decrease in plant respiration according to the temperature sensitivity. Application of the new formulation shows a global reduction of 4.5 -6 % in plant respiration and an increase of 7-10% in net primary production for the present-day.Natural Environment Research Council (NERC)University of ExeterMet Office Hadley Centre Climate Programm