ABSTRACT
Parathyroid hormone 2 (Pth2) is a vertebrate-specific neuropeptide for which thalamic expression is upregulated by social contact with conspecifics. However, social interactions fail to ...stimulate pth2 expression in isolated zebrafish in which lateral line hair cells have been chemically ablated. These results suggest that modulation of pth2 by social context is acutely dependent on mechanosensory information from the lateral line. However, it is unclear how a congenital loss of lateral line function influences the ability of zebrafish to interpret their social environment. In this study, we measure pth2 levels in zebrafish mutants lacking hair cell function in either the lateral line only, or in both the inner ear and lateral line. Socially raised lateral line mutants express lower levels of pth2 relative to wild-type siblings, but there is no further reduction when all sensory hair cells are nonfunctional. However, social isolation of hair cell mutants causes a further reduction in pth2 expression, pointing to additional unidentified sensory cues that influence pth2 production. Lastly, we report that social context modulates fluorescent transgenes driven by the pth2 promoter. Altogether, these data suggest that lateral line mutants experience a form of isolation, even when raised in a social environment.
This article has an associated First Person interview with the first author of the paper.
Treatment decisions for men diagnosed with prostate cancer depend on a range of clinical and patient characteristics such as disease stage, age, general health, risk of side effects and access. ...Associations between treatment patterns and area-level factors such as remoteness and socioeconomic disadvantage have been observed in many countries. To model spatial differences in interventional treatment rates for prostate cancer at high spatial resolution to inform policy and decision-making. Hospital separations data for interventional treatments for prostate cancer (radical prostatectomy, low dose rate and high dose rate brachytherapy) for men aged 40 years and over were modelled using spatial models, generalised linear mixed models, maximised excess events tests and k-means statistical clustering. Geographic differences in population rates of interventional treatments were found (p<0.001). Separation rates for radical prostatectomy were lower in remote areas (12.2 per 10 000 person-years compared with 15.0-15.9 in regional and major city areas). Rates for all treatments decreased with increasing socioeconomic disadvantage (radical prostatectomy 19.1 /10 000 person-years in the most advantaged areas compared with 12.9 in the most disadvantaged areas). Three groups of similar areas were identified: those with higher rates of radical prostatectomy, those with higher rates of low dose brachytherapy, and those with low interventional treatment rates but higher rates of excess deaths. The most disadvantaged areas and remote areas tended to be in the latter group. The geographic differences in treatment rates may partly reflect differences in patients' physical and financial access to treatments. Treatment rates also depend on diagnosis rates and thus reflect variation in investigation rates for prostate cancer and presentation of disease. Spatial variation in interventional treatments may aid identification of areas of under-treatment or over-treatment.
A forward atmospheric transport modeling experiment has been coordinated by the TransCom group to investigate synoptic and diurnal variations in CO2. Model simulations were run for biospheric, ...fossil, and air‐sea exchange of CO2 and for SF6 and radon for 2000–2003. Twenty‐five models or model variants participated in the comparison. Hourly concentration time series were submitted for 280 sites along with vertical profiles, fluxes, and meteorological variables at 100 sites. The submitted results have been analyzed for diurnal variations and are compared with observed CO2 in 2002. Mean summer diurnal cycles vary widely in amplitude across models. The choice of sampling location and model level account for part of the spread suggesting that representation errors in these types of models are potentially large. Despite the model spread, most models simulate the relative variation in diurnal amplitude between sites reasonably well. The modeled diurnal amplitude only shows a weak relationship with vertical resolution across models; differences in near‐surface transport simulation appear to play a major role. Examples are also presented where there is evidence that the models show useful skill in simulating seasonal and synoptic changes in diurnal amplitude.
This paper documents the biogeochemistry configuration of the Energy Exascale Earth System Model (E3SM), E3SMv1.1‐BGC. The model simulates historical carbon cycle dynamics, including carbon losses ...predicted in response to land use and land cover change, and the responses of the carbon cycle to changes in climate. In addition, we introduce several innovations in the treatment of soil nutrient limitation mechanisms, including explicit dependence on phosphorus availability. The suite of simulations described here includes E3SM contributions to the Coupled Climate‐Carbon Cycle Model Intercomparison Project and other projects, as well as simulations to explore the impacts of structural uncertainty in representations of nitrogen and phosphorus limitation. We describe the model spin‐up and evaluation procedures, provide an overview of results from the simulation campaign, and highlight key features of the simulations. Cumulative warming over the twentieth century is similar to observations, with a midcentury cold bias offset by stronger warming in recent decades. Ocean biomass production and carbon uptake are underpredicted, likely due to biases in ocean transport leading to widespread anoxia and undersupply of nutrients to surface waters. The inclusion of nutrient limitations in the land biogeochemistry results in weaker carbon fertilization and carbon‐climate feedbacks than exhibited by other Earth System Models that exclude those limitations. Finally, we compare with an alternative representation of terrestrial biogeochemistry, which differs in structure and in initialization of soil phosphorus. While both configurations agree well with observational benchmarks, they differ significantly in their distribution of carbon among different pools and in the strength of nutrient limitations.
Plain Language Summary
A new state‐of‐the‐art Earth System Model has been funded by the United States Department of Energy (DOE) to explore questions relevant to DOE's mission. The Energy Exascale Earth System Model version 1.1 (E3SMv1.1) represents nitrogen and phosphorous controls on the carbon cycle and extends the recently released E3SMv1 to include active biogeochemistry in the land, ocean, and ice components. E3SMv1.1 also includes an alternative representation of terrestrial carbon and nutrient cycles that is used to explore model structural uncertainties. E3SMv1.1's capabilities are demonstrated through a set of experiments described by the Coupled Climate‐Carbon Cycle Model Intercomparison Project, aimed at understanding the influence of changes in climate and CO2 on the carbon cycle. Simulations of the land surface properties and terrestrial carbon cycle compare well with observations, as does the simulated global and regional climate. Nutrient limitations result in less land carbon uptake compared to models that exclude these limitations. However, variations in model structure and initialization influence the magnitude of those limitations and carbon cycle dynamics. The ocean biogeochemistry in E3SMv1.1 simulates less biomass and slightly lower anthropogenic carbon uptake than is observed. Future efforts will aim to reduce model biases as well as to include additional aspects of global carbon cycle dynamics.
Key Points
Introduces the U.S. DOE's Energy Exascale Earth System Model‐Biogeochemistry version, E3SMv1.1‐BGC, is introduced
Ecosystem‐climate responses are characterized in a standard set of C4MIP‐type simulations
The impacts of terrestrial nitrogen and phosphorus limitations and their structural uncertainties are explored
Measurements of the 14C content of carbon dioxide in air collected by high‐altitude balloon flights in 2003–2005 reveal the contemporary radiocarbon distribution in the northern midlatitude ...stratosphere, four decades after the Limited Test Ban Treaty restricted atmospheric testing of nuclear weapons. Comparisons with results from a 3‐D chemical‐transport model show that the 14CO2 distribution is now largely governed by the altitude/latitude dependence of the natural cosmogenic production rate, stratospheric transport, and propagation into the stratosphere of the decreasing radiocarbon trend in tropospheric CO2 due to fossil fuel combustion. From the observed correlation of 14CO2 with N2O mixing ratios, an annual global mean net flux of 14CO2 to the troposphere of 1.6(±0.4) × 1017‰ mol CO2 yr−1 and a global production rate of 2.2(±0.6) × 1026 atoms 14C yr−1 are empirically derived. The results also indicate that contemporary 14CO2 observations provide highly sensitive diagnostics for stratospheric transport and residence times in models.
Key Points
Stratospheric 14C is governed by cosmogenic production, transport, and stratosphere‐troposphere exchange
Global annual mean 14C production rate and net flux to the troposphere are determined empirically
14C is a sensitive tracer of stratospheric transport and residence times
Abstract Objective To compare the health status of people claiming compensation for injuries sustained in road traffic crashes (RTC), with people who do not claim compensation. Design Prospective ...cohort study. Setting Australian Capital Territory, Australia and a fault based common law compensation scheme. Subjects People presenting to the emergency department with mild to moderate musculoskeletal injury following RTC. Main outcome measures Physical Component Score (PCS) and Mental Component Score (MCS) of the Short Form 36 (SF-36) health status measure, Hospital Anxiety and Depression Scale (HADS) and the Functional Rating Index (FRI). These measures are recorded immediately post crash, at 6 and 12 months post crash. Results 95 people participated in the study and were enrolled a mean of 8.6 (median 8) days following the crash. 86% were followed up to 12 months after injury. Mean age was 37 years, 61% were female and 91% were employed at the time of their injury. 33% ultimately claimed compensation, and 25% engaged a lawyer. There were no major differences in baseline personal characteristics or injury related factors between the groups. As expected, involvement as a passenger and in multiple vehicle crashes, were more frequent in the group claiming compensation. Over the duration of the study claiming compensation was associated with lower SF-36 PCS (−5.5 (95%CI −8.6 to −2.4), p = 0.001), greater HADS-Anxiety (1.7 (95%CI 0.2–3.3), p = 0.048), and worse FRI (11.2 (95%CI 3.9–18.5), p = 0.003). There was a highly significant improvement in health status between baseline and 6 months after injury, but no further significant change between 6 and 12 months after injury. There was no difference in rate of improvement between the groups. Claiming compensation and psychological factors were independent predictors of worse health status at 12 months. Conclusion In this study the group claiming compensation had overall worse health status following mild to moderate musculoskeletal injuries over the course of the study. There was no difference in rate of improvement between the groups. However, it is not possible to determine whether this negative effect was due to claiming compensation itself or the presence of other unmeasured factors.
Efficient and effective nutrient management decisions are critical to profitable and sustainable milk production on modern Australian dairy farms. Whole-farm nutrient balances are commonly used as ...nutrient management tools and also for regulatory assessment on dairy farms internationally, but are rarely used in Australia. In this study, nitrogen (N), phosphorus (P), potassium (K), and sulfur (S) imports and exports were measured during a standardised production year on 41 contrasting Australian dairy farms, representing a broad range of geographic locations, milk production, herd and farm size, reliance on irrigation, and soil types. The quantity of nutrients imported varied markedly – with feed and fertiliser generally the most substantial imports – and were principally determined by stocking rate and type of imported feed. Milk exports were the largest source of nutrient exports. Nitrogen balance ranged from 47 to 601 kg N/ha.year. Nitrogen-use efficiency ranged from 14 to 50%, with a median value of 26%. Phosphorus balance ranged from –7 to 133 kg P/ha.year, with a median value of 28 kg P/ha. Phosphorus-use efficiencies ranged from 6 to 158%, with a median value of 35%. Potassium balances ranged from 13 to 452 kg K/ha, with a median value of 74 kg K/ha; K-use efficiency ranged from 9 to 48%, with a median value of 20%. Sulfur balances ranged from –1 to 184 kg S/ha, with a median value of 27 kg S/ha; S-use efficiency ranged from 6 to 110%, with a median value of 21%. Nitrogen, P, K and S balances were all positively correlated (P < 0.001) with stocking rate and milk production per ha. Poor relationship between P, K and S fertiliser inputs and milk production from home-grown pasture reflected the already high soil fertility levels measured on many of these farms. The results from this study demonstrate that increasing milk production per ha will be associated with greater nutrient surpluses at the farm scale, with the potential for greater environmental impacts. We suggest that simplified and standardised nutrient balance methodologies should be used on dairy farms in Australia to help identify opportunities for improvements in nutrient management decisions and to develop appropriate industry benchmarks and targets.
There is a growing body of empirical evidence documenting the expansion of shrub vegetation in the circumpolar Arctic in response to climate change. Here, we conduct a series of idealized experiments ...with the Community Climate System Model to analyze the potential impact on boreal climate of a large-scale tundra-to-shrub conversion. The model responds to an increase in shrub abundance with substantial atmospheric heating arising from two seasonal land-atmosphere feedbacks: a decrease in surface albedo and an evapotranspiration-induced increase in atmospheric moisture content. We demonstrate that the strength and timing of these feedbacks are sensitive to shrub height and the time at which branches and leaves protrude above the snow. Taller and aerodynamically rougher shrubs lower the albedo earlier in the spring and transpire more efficiently than shorter shrubs. These mechanisms increase, in turn, the strength of the indirect sea-ice albedo and ocean evaporation feedbacks contributing to additional regional warming. Finally, we find that an invasion of tall shrubs tends to systematically warm the soil, deepen the active layer, and destabilize the permafrost (with increased formation of taliks under a future scenario) more substantially than an invasion of short shrubs.
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