Implications For Future Change Research Articles

Editorial preface to special issue: Neogene-Quaternary changes of the Indo-Pacific Warm Pool encompassing oceanic, hydrologic and carbon cycles, and their implications for future change

The Indo-Pacific Warm Pool (IPWP) is the primary supplier of heat and moisture to the global atmosphere, and exerts a significant impact on tropical and worldwide climate variability. This special issue expands our understanding of the paleoceanographic and paleoclimatic evolution of the IPWP since Neogene times with implications for understanding future change. It contains fifteen research articles addressing two primary themes: (1) Ocean-atmosphere coupled processes via the ocean water-column, sea surface, atmospheric evaporation/precipitation; and (2) Sediment source-to-sink and biogeochemical carbon-cycles, and their interactions with oceanographic, hydrological, tectonic and other factors. These contributions improve our understanding of thermocline temperature, salinity, oxygenation, hydrography, carbon cycle, biological productivity, and sedimentary response in the IPWP across Neogene and Quaternary time scales, as well as aiding in the forecast of future climate responses in the context of current global warming. The special issue will capture the attention of geologists, climatologists, and anybody else interested in global climate change.

Financial Implications of Evolving Breast Cancer Radiotherapy Treatment Protocols

Adjuvant radiotherapy for breast cancer represents a significant portion of radiotherapy (RT) treatments. The resource implications of evidence-based changes in treatment protocols must be defined to facilitate RT service planning. We designed a study to calculate the impact of past changes and create a model to allow prediction of costs implications for future changes. Changes in RT treatment (shown in table 1) in the past 3 years were identified in consultation with clinical staff and by reviewing institutional treatment guidelines. Resource and infrastructure costs were calculated for each protocol. Staff time was calculated using standard time slots where known (e.g., CT simulation appointment) and estimates based on discussion with staff (e.g., time to plan whole breast RT). Cost / Gy was calculated based on Linac cost of €2.5M, 10% annual service charge over 12-year lifetime, 2.7 patients treated / hour (verified institutional metric) and standard 2Gy fraction, giving €37.72 / Gy. We did not include facilities costs nor account for differing treatment outcomes. We collected relevant data on a consecutive 6-month sample (Jan - Jun 2019) of women receiving adjuvant RT for breast cancer (n = 224). Total costs were calculated by applying costs for each protocol change to the women in this cohort eligible for the changes. Protocol changes and costs are summarized in table 1. The use of DIBH for women <60 years receiving IMN RT (left and right sided) added a cost. The largest cost saving resulted from more selective tumor bed boost, a saving of €462,138. The potential impact of a 5-fraction boost for women with non-low risk DCIS was estimated. In the cohort analyzed, identified changes in adjuvant breast radiotherapy resulted in overall savings due to updated indications for boost and the implementation of ultra-hypofractionated radiotherapy. We are now analyzing the impact of introducing simultaneous integrated boost and partial breast radiotherapy.

Investigating the representation of heatwaves from an ensemble of km-scale regional climate simulations within CORDEX-FPS convection

AbstractHeatwaves (HWs) are high-impact phenomena stressing both societies and ecosystems. Their intensity and frequency are expected to increase in a warmer climate over many regions of the world. While these impacts can be wide-ranging, they are potentially influenced by local to regional features such as topography, land cover, and urbanization. Here, we leverage recent advances in the very high-resolution modelling required to elucidate the impacts of heatwaves at these fine scales. Further, we aim to understand how the new generation of km-scale regional climate models (RCMs) modulates the representation of heatwaves over a well-known climate change hot spot. We analyze an ensemble of 15 convection-permitting regional climate model (CPRCM, ~ 2–4 km grid spacing) simulations and their driving, convection-parameterized regional climate model (RCM, ~ 12–15 km grid spacing) simulations from the CORDEX Flagship Pilot Study on Convection. The focus is on the evaluation experiments (2000–2009) and three subdomains with a range of climatic characteristics. During HWs, and generally in the summer season, CPRCMs exhibit warmer and drier conditions than their driving RCMs. Higher maximum temperatures arise due to an altered heat flux partitioning, with daily peaks up to ~ 150 W/m2 larger latent heat in RCMs compared to the CPRCMs. This is driven by a 5–25% lower soil moisture content in the CPRCMs, which is in turn related to longer dry spell length (up to double). It is challenging to ascertain whether these differences represent an improvement. However, a point-scale distribution-based maximum temperature evaluation, suggests that this CPRCMs warmer/drier tendency is likely more realistic compared to the RCMs, with ~ 70% of reference sites indicating an added value compared to the driving RCMs, increasing to 95% when only the distribution right tail is considered. Conversely, a CPRCMs slight detrimental effect is found according to the upscaled grid-to-grid approach over flat areas. Certainly, CPRCMs enhance dry conditions, with knock-on implications for summer season temperature overestimation. Whether this improved physical representation of HWs also has implications for future changes is under investigation.

Centralisation of specialist cancer surgery services in two areas of England: the RESPECT-21 mixed-methods evaluation

Background Centralising specialist cancer surgical services is an example of major system change. High-volume centres are recommended to improve specialist cancer surgery care and outcomes. Objective Our aim was to use a mixed-methods approach to evaluate the centralisation of specialist surgery for prostate, bladder, renal and oesophago-gastric cancers in two areas of England [i.e. London Cancer (London, UK), which covers north-central London, north-east London and west Essex, and Greater Manchester Cancer (Manchester, UK), which covers Greater Manchester]. Design Stakeholder preferences for centralising specialist cancer surgery were analysed using a discrete choice experiment, surveying cancer patients (n = 206), health-care professionals (n = 111) and the general public (n = 127). Quantitative analysis of impact on care, outcomes and cost-effectiveness used a controlled before-and-after design. Qualitative analysis of implementation and outcomes of change used a multisite case study design, analysing documents (n = 873), interviews (n = 212) and non-participant observations (n = 182). To understand how lessons apply in other contexts, we conducted an online workshop with stakeholders from a range of settings. A theory-based framework was used to synthesise these approaches. Results Stakeholder preferences – patients, health-care professionals and the public had similar preferences, prioritising reduced risk of complications and death, and better access to specialist teams. Travel time was considered least important. Quantitative analysis (impact of change) – only London Cancer’s centralisations happened soon enough for analysis. These changes were associated with fewer surgeons doing more operations and reduced length of stay [prostate –0.44 (95% confidence interval –0.55 to –0.34) days; bladder –0.563 (95% confidence interval –4.30 to –0.83) days; renal –1.20 (95% confidence interval –1.57 to –0.82) days]. The centralisation meant that renal patients had an increased probability of receiving non-invasive surgery (0.05, 95% confidence interval 0.02 to 0.08). We found no evidence of impact on mortality or re-admissions, possibly because risk was already low pre-centralisation. London Cancer’s prostate, oesophago-gastric and bladder centralisations had medium probabilities (79%, 62% and 49%, respectively) of being cost-effective, and centralising renal services was not cost-effective (12% probability), at the £30,000/quality-adjusted life-year threshold. Qualitative analysis, implementation and outcomes – London Cancer’s provider-led network overcame local resistance by distributing leadership throughout the system. Important facilitators included consistent clinical leadership and transparent governance processes. Greater Manchester Cancer’s change leaders learned from history to deliver the oesophago-gastric centralisation. Greater Manchester Cancer’s urology centralisations were not implemented because of local concerns about the service model and local clinician disengagement. London Cancer’s network continued to develop post implementation. Consistent clinical leadership helped to build shared priorities and collaboration. Information technology difficulties had implications for interorganisational communication and how reliably data follow the patient. London Cancer’s bidding processes and hierarchical service model meant that staff reported feelings of loss and a perceived ‘us and them’ culture. Workshop – our findings resonated with workshop attendees, highlighting issues about change leadership, stakeholder collaboration and implications for future change and evaluation. Limitations The discrete choice experiment used a convenience sample, limiting generalisability. Greater Manchester Cancer implementation delays meant that we could study the impact of only London Cancer changes. We could not analyse patient experience, quality of life or functional outcomes that were important to patients (e.g. continence). Future research Future research may focus on impact of change on care options offered, patient experience, functional outcomes and long-term sustainability. Studying other approaches to achieving high-volume services would be valuable. Study registration National Institute for Health and Care Research (NIHR) Clinical Research Network Portfolio reference 19761. Funding This project was funded by the NIHR Health and Social Care Delivery Research programme and will be published in full in Health and Social Care Delivery Research; Vol. 11, No. 2. See the NIHR Journals Library website for further project information.

Concordant changes in late Holocene hydroclimate across southern Patagonia modulated by westerly winds and the El Niño–Southern Oscillation

AbstractThe southern westerly winds influence weather patterns and water resources across the southern high-latitude regions, with important socioeconomic impacts. The strengthening and poleward migration of these winds since the late 20th century also have implications for regional environmental change, including drought, wildfire, and sea-ice loss. However, it is challenging to recognize the natural variability of the westerlies and predict their future behavior, as those recent changes have been influenced by anthropogenic factors. We present a 4200-yr-long record from a southern Patagonian peatland in a location that is sensitive to changes in the position and/or strength of the westerlies. Our δ13C record shows a 6‰ increasing trend from 4200 to 1200 cal. yr B.P., indicating a progressive, millennial-scale increase in peatland moisture. This long-term trend is attributed to an increase in moisture induced by strengthening southern westerly winds associated with a change in the mean state of the El Niño–Southern Oscillation (ENSO) system. Superimposed on this millennial trend, centennial-scale shifts in hydroclimate persist into modern times. We suggest that a “paleo”–Southern Annular Mode, which is linked to tropical Pacific climate, with dry events contemporaneous with positive phases and La Niña–like conditions, is responsible for this enhanced hydroclimate variability. Overall, our results point to millennial- and centennial-scale changes in hydroclimate during the late Holocene that link tropical Pacific climate variability with the Southern Annular Mode and the southern westerlies, with far-reaching implications for future changes in the southern high latitudes, including CO2 ventilation from the Southern Ocean.

Future Amplification of Sea Surface Temperature Seasonality Due To Enhanced Ocean Stratification

AbstractIn many regions the projected future sea surface temperature (SST) response to greenhouse warming is larger in summer than in winter. What causes this amplification of the SST seasonal cycle has remained unclear. To determine robustness of the projected seasonal cycle intensification and ascertain underlying physical mechanisms we analyze a suite of historical and greenhouse warming simulations conducted with 13 coupled general circulation models in the Coupled Model Intercomparison Project Phase 5. In the Representative Concentration Pathway 8.5 scenario, the amplitude of SST seasonal cycle, defined as the difference between climatological maximum and minimum temperature, increases by 30% ± 20% on average by the end of 21st century. Analysis of a simplified mixed layer heat budget demonstrates that the amplification can be attributed to the increasing upper ocean stratification and hence shoaling of the annual‐mean mixed layer. The projected intensification of SST seasonality may have important implications for future changes in marine ecosystems.

Increased Large‐Scale Convective Aggregation in CMIP5 Projections: Implications for Tropical Precipitation Extremes

AbstractConvective aggregation refers to the clustering of convective events and occurs on a wide range of spatial scales. It has been suggested that the behavior of convective aggregation may change under global warming, with potential implications for future changes in precipitation extremes. Here, convective regions of the tropics are defined from a percentile threshold on gridded daily precipitation data and used to quantify large‐scale convective aggregation in an ensemble of global climate models. Applying three separate indices for aggregation, it is found that large‐scale convective aggregation increases in 17 of the 19 analyzed models under future warming. However, aggregation is found not to be correlated with tropical‐mean precipitation extremes, either climatologically or with respect to the sensitivity to warming. The large model spread in aggregation indices across the ensemble suggests the possible utility of large‐scale convective aggregation as a target for model evaluation.

Discharge and Temperature Controls of Dissolved Organic Matter (DOM) in a Forested Coastal Plain Stream

Streams in the southeastern United States Coastal Plains serve as an essential source of energy and nutrients for important estuarine ecosystems, and dissolved organic matter (DOM) exported from these streams can have profound impacts on the biogeochemical and ecological functions of fluvial networks. Here, we examined hydrological and temperature controls of DOM during low-flow periods from a forested stream located within the Coastal Plain physiographic region of Alabama, USA. We analyzed DOM via combining dissolved organic carbon (DOC) analysis, fluorescence excitation–emission matrix combined with parallel factor analysis (EEM-PARAFAC), and microbial degradation experiments. Four fluorescence components were identified: terrestrial humic-like DOM, microbial humic-like DOM, tyrosine-like DOM, and tryptophan-like DOM. Humic-like DOM accounted for ~70% of total fluorescence, and biodegradation experiments showed that it was less bioreactive than protein-like DOM that accounted for ~30% of total fluorescence. This observation indicates fluorescent DOM (FDOM) was controlled primarily by soil inputs and not substantially influenced by instream production and processing, suggesting that the bulk of FDOM in these streams is transported to downstream environments with limited in situ modification. Linear regression and redundancy analysis models identified that the seasonal variations in DOM were dictated primarily by hydrology and temperature. Overall, high discharge and shallow flow paths led to the enrichment of less-degraded DOM with higher percentages of microbial humic-like and tyrosine-like compounds, whereas high temperatures favored the accumulation of high-aromaticity, high-molecular-weight, terrestrial, humic-like compounds in stream water. The flux of DOC and four fluorescence components was driven primarily by water discharge. Thus, the instantaneous exports of both refractory humic-like DOM and reactive protein-like DOM were higher in wetter seasons (winter and spring). As high temperatures and severe precipitation are projected to become more prominent in the southeastern U.S. due to climate change, our findings have important implications for future changes in the amount, source, and composition of DOM in Coastal Plain streams and the associated impacts on downstream carbon and nutrient supplies and water quality.

Retreat of the Antarctic Ice Sheet During the Last Interglaciation and Implications for Future Change

AbstractThe Antarctic Ice Sheet (AIS) response to past warming consistent with the 1.5–2°C “safe limit” of the United Nations Paris Agreement is currently not well known. Empirical evidence from the most recent comparable period, the Last Interglaciation, is sparse, and transient ice‐sheet experiments are few and inconsistent. Here, we present new, transient, GCM‐forced ice‐sheet simulations validated against proxy reconstructions. This is the first time such an evaluation has been attempted. Our empirically constrained simulations indicate that the AIS contributed 4 m to global mean sea level by 126 ka BP, with ice lost primarily from the Amundsen, but not Ross or Weddell Sea, sectors. We resolve the conflict between previous work and show that the AIS thinned in the Wilkes Subglacial Basin but did not retreat. We also find that the West AIS may be predisposed to future collapse even in the absence of further environmental change, consistent with previous studies.

Explaining the Spatial Pattern of U.S. Extreme Daily Precipitation Change

AbstractObserved United States trends in the annual maximum 1-day precipitation (RX1day) over the last century consist of 15%–25% increases over the eastern United States (East) and 10% decreases over the far western United States (West). This heterogeneous trend pattern departs from comparatively uniform observed increases in precipitable water over the contiguous United States. Here we use an event attribution framework involving parallel sets of global atmospheric model experiments with and without climate change drivers to explain this spatially diverse pattern of extreme daily precipitation trends. We find that RX1day events in our model ensembles respond to observed historical climate change forcing differently across the United States with 5%–10% intensity increases over the East but no appreciable change over the West. This spatially diverse forced signal is broadly similar among three models used, and is positively correlated with the observed trend pattern. Our analysis of model and observations indicates the lack of appreciable RX1day signals over the West is likely due to dynamical effects of climate change forcing—via a wintertime atmospheric circulation anomaly that suppresses vertical motion over the West—largely cancelling thermodynamic effects of increased water vapor availability. The large magnitude of eastern U.S. RX1day increases is unlikely a symptom of a regional heightened sensitivity to climate change forcing. Instead, our ensemble simulations reveal considerable variability in RX1day trend magnitudes arising from internal atmospheric processes alone, and we argue that the remarkable observed increases over the East has most likely resulted from a superposition of strong internal variability with a moderate climate change signal. Implications for future changes in U.S. extreme daily precipitation are discussed.

Sensitivity of the Atlantic Meridional Overturning Circulation to Model Resolution in CMIP6 HighResMIP Simulations and Implications for Future Changes

AbstractA multimodel, multiresolution ensemble using Coupled Model Intercomparison Project Phase 6 (CMIP6) High Resolution Model Intercomparison Project (HighResMIP) coupled experiments is used to assess the performance of key aspects of the North Atlantic circulation. The Atlantic Meridional Overturning Circulation (AMOC), and related heat transport, tends to become stronger as ocean model resolution is enhanced, better agreeing with observations at 26.5°N. However, for most models the circulation remains too shallow compared to observations and has a smaller temperature contrast between the northward and southward limbs of the AMOC. These biases cause the northward heat transport to be systematically too low for a given overturning strength. The higher‐resolution models also tend to have too much deep mixing in the subpolar gyre. In the period 2015–2050 the overturning circulation tends to decline more rapidly in the higher‐resolution models, which is related to both the mean state and to the subpolar gyre contribution to deep water formation. The main part of the decline comes from the Florida Current component of the circulation. Such large declines in AMOC are not seen in the models with resolutions more typically used for climate studies, suggesting an enhanced risk for Northern Hemisphere climate change. However, only a small number of different ocean models are included in the study.

Fluvial CO2 and CH4 patterns across wildfire-disturbed ecozones of subarctic Canada: Current status and implications for future change.

Despite occupying a small fraction of the landscape, fluvial networks are disproportionately large emitters of CO2 and CH4 , with the potential to offset terrestrial carbon sinks. Yet the extent of this offset remains uncertain, because current estimates of fluvial emissions often do not integrate beyond individual river reaches and over the entire fluvial network in complex landscapes. Here we studied broad patterns of concentrations and isotopic signatures of CO2 and CH4 in 50 streams in the western boreal biome of Canada, across an area of 250,000km2 . Our study watersheds differ starkly in their geology (sedimentary and shield), permafrost extent (sporadic to extensive discontinuous) and land cover (large variability in lake and wetland extents). We also investigated the effect of wildfire, as half of our study streams drained watersheds affected by megafires that occurred 3years prior. Similar to other boreal regions, we found that stream CO2 concentrations were primarily associated with greater terrestrial productivity and warmer climates, and decreased downstream within the fluvial network. No effects of recent wildfire, bedrock geology or land cover composition were found. The isotopic signatures suggested dominance of biogenic CO2 sources, despite dominant carbonate bedrock in parts of the study region. Fluvial CH4 concentrations had a high variability which could not be explained by any landscape factors. Estimated fluvial CO2 emissions were 0.63 (0.09-6.06, 95% CI) and 0.29 (0.17-0.44, 95% CI) g C m-2 year-1 at the landscape scale using a stream network modelling and a mass balance approach, respectively, a small but potentially important component of the landscape C balance. These fluvial CO2 emissions are lower than in other northern regions, likely due to a drier climate. Overall, our study suggests that fluvial CO2 emissions are unlikely to be sensitive to altered fire regimes, but that warming and permafrost thaw will increase emissions significantly.

Contingent Behavior and Asymmetric Preferences for Baltic Sea Coastal Recreation

In this study, we augment the traditional travel cost approach with contingent behavior data for coastal recreation. The objective is to analyze the welfare implications of future changes in the conditions of the Baltic Sea due to climate change and eutrophication. Adding to the literature, we assess the symmetricity of welfare effects caused by improvements and deteriorations in environmental conditions for a set of quality attributes. Responses are derived from identical online surveys in Finland, Germany and Latvia. We estimate recreational benefits using linear and non-linear negative binomial random-effects models. The calculated annual consumer surpluses are considerably influenced by the magnitude of the environmental changes in the three countries. We also observe asymmetries in the effects of environmental improvements and deteriorations on the expected number of visits. In particular, the results indicate that deteriorations lead to larger or more significant impacts than improvements in the case of blue-green algal blooms and algae onshore for Finland, water clarity for Germany, and water clarity and blue-green algal blooms for Latvia. For the remaining attributes, the effects are ambiguous.

Private versus Public Corporate Ownership: Implications for Future Changes in Profitability

ABSTRACTWe investigate the association between public versus private ownership and future changes in profitability. Managers have long debated the implications of public and private corporate ownership; however, little empirical research has provided insight into the issue. We find robust evidence that public firms are associated with significantly lower future changes in operating profitability compared to private firms matched on current profitability, size, growth, and industry. We also find that the differential future changes in profitability of public and private firms manifests in both future changes in profit margins and changes in asset turnovers. Additionally, we find evidence consistent with an association between short-termism, competition, and agency costs and the lower future changes in profitability for public versus private firms. The results provide insight for managers and investors into the differential future changes in profitability of public versus private firms and into the factors that drive the differential profitability.JEL Classifications: M41; M42; M44.Data Availability: Data are available from sources identified in the paper.

SNAP benefit levels and enrollment rates by race and place: evidence from Georgia, 2007–2013

ABSTRACTThe U.S. Department of Agriculture’s Supplemental Nutrition Assistance Program (SNAP) decreases poverty and food insecurity for millions of Americans. Yet not all eligible households participate, and disparities in participation exist by household size, race, ethnicity, and place. We examine the county-level associations between maximum benefit levels and SNAP enrollment by household size, race, ethnicity, and metropolitan status from 2007 to 2013 in the state of Georgia. National county-level data on participation in SNAP by racial or ethnic group are not available, but Georgia features substantial variation by race and ethnicity as well as metropolitan status at the county level that make it well suited for our analysis. Maximum SNAP benefit levels were associated with increases in county-level SNAP enrollment across the board but especially for single-person households, Hispanics, and rural Whites. These findings have implications for future changes to SNAP benefits.

Engaging stakeholders in research to address water\u2013energy\u2013food (WEF) nexus challenges

The water–energy–food (WEF) nexus has become a popular, and potentially powerful, frame through which to analyse interactions and interdependencies between these three systems. Though the case for transdisciplinary research in this space has been made, the extent of stakeholder engagement in research remains limited with stakeholders most commonly incorporated in research as end-users. Yet, stakeholders interact with nexus issues in a variety of ways, consequently there is much that collaboration might offer to develop nexus research and enhance its application. This paper outlines four aspects of nexus research and considers the value and potential challenges for transdisciplinary research in each. We focus on assessing and visualising nexus systems; understanding governance and capacity building; the importance of scale; and the implications of future change. The paper then proceeds to describe a novel mixed-method study that deeply integrates stakeholder knowledge with insights from multiple disciplines. We argue that mixed-method research designs—in this case orientated around a number of cases studies—are best suited to understanding and addressing real-world nexus challenges, with their inevitable complex, non-linear system characteristics. Moreover, integrating multiple forms of knowledge in the manner described in this paper enables research to assess the potential for, and processes of, scaling-up innovations in the nexus space, to contribute insights to policy and decision making.

How climate model biases skew the distribution of iceberg meltwater

The discharge of icebergs into the polar oceans is expected to increase over the coming century, which raises the importance of accurate representations of icebergs in global climate models (GCMs) used for future projections. Here we analyze the prospects for interactive icebergs in GCMs by forcing an iceberg drift and decay model with circulation and temperature fields from (i) state‐of‐the‐art GCM output and (ii) an observational state estimate. The spread of meltwater is found to be smaller for the GCM than for the observational state estimate, despite a substantial high wind bias in the GCM—a bias that is similar to most current GCMs. We argue that this large‐scale reduction in the spread of meltwater occurs primarily due to localized differences in ocean currents, which may be related to the coarseness of the horizontal resolution in the GCM. The high wind bias in the GCM is shown to have relatively little impact on the meltwater distribution, despite Arctic iceberg drift typically being dominated by the wind forcing. We find that this is due to compensating effects between faster drift under stronger winds and larger wind‐driven wave erosion. These results may have implications for future changes in the Atlantic meridional overturning circulation simulated with iceberg‐enabled GCMs.

Compression of Morbidity and Mortality: New Perspectives

Compression of morbidity is a reduction over time in the total lifetime days of chronic disability, reflecting a balance between (1) morbidity incidence rates and (2) case-continuance rates, generated by case-fatality and case-recovery rates. Chronic disability includes limitations in activities of daily living and cognitive impairment, which can be covered by long-term-care insurance. Morbidity improvement can lead to a compression of morbidity if the reductions in age-specific prevalence rates are sufficiently large to overcome the increases in lifetime disability due to concurrent mortality improvements and progressively higher disability prevalence rates with increasing age. Compression of mortality is a reduction over time in the variance of age at death. Such reductions are generally accompanied by increases in the mean age at death; otherwise, for the variances to decrease, the death rates above the mean age at death would need to increase, and this has rarely been the case. Mortality improvement is a reduction over time in the age-specific death rates and a corresponding increase in the cumulative survival probabilities and age-specific residual life expectancies. Mortality improvement does not necessarily imply concurrent compression of mortality. This article reviews these concepts, describes how they are related, shows how they apply to changes in mortality over the past century and to changes in morbidity over the past 30 years, and discusses their implications for future changes in the United States. The major findings of the empirical analyses are the substantial slowdowns in the degree of mortality compression over the past half century and the unexpectedly large degree of morbidity compression that occurred over the morbidity/disability study period 1984–2004; evidence from other published sources suggests that morbidity compression may be continuing.

National Outbreak of Multidrug Resistant Salmonella Heidelberg Infections Linked to a Single Poultry Company.

ImportanceThis large outbreak of foodborne salmonellosis demonstrated the complexity of investigating outbreaks linked to poultry products. The outbreak also highlighted the importance of efforts to strengthen food safety policies related to Salmonella in chicken parts and has implications for future changes within the poultry industry.ObjectiveTo investigate a large multistate outbreak of multidrug resistant Salmonella Heidelberg infections.DesignEpidemiologic and laboratory investigations of patients infected with the outbreak strains of Salmonella Heidelberg and traceback of possible food exposures.SettingUnited States. Outbreak period was March 1, 2013 through July 11, 2014PatientsA case was defined as illness in a person infected with a laboratory-confirmed Salmonella Heidelberg with 1 of 7 outbreak pulsed-field gel electrophoresis (PFGE) XbaI patterns with illness onset from March 1, 2013 through July 11, 2014. A total of 634 case-patients were identified through passive surveillance; 200/528 (38%) were hospitalized, none died.ResultsInterviews were conducted with 435 case-patients: 371 (85%) reported eating any chicken in the 7 days before becoming ill. Of 273 case-patients interviewed with a focused questionnaire, 201 (74%) reported eating chicken prepared at home. Among case-patients with available brand information, 152 (87%) of 175 patients reported consuming Company A brand chicken. Antimicrobial susceptibility testing was completed on 69 clinical isolates collected from case-patients; 67% were drug resistant, including 24 isolates (35%) that were multidrug resistant. The source of Company A brand chicken consumed by case-patients was traced back to 3 California production establishments from which 6 of 7 outbreak strains were isolated.ConclusionsEpidemiologic, laboratory, traceback, and environmental investigations conducted by local, state, and federal public health and regulatory officials indicated that consumption of Company A chicken was the cause of this outbreak. The outbreak involved multiple PFGE patterns, a variety of chicken products, and 3 production establishments, suggesting a reservoir for contamination upstream from the production establishments. Sources of bacteria and genes responsible for resistance, such as farms providing birds for slaughter or environmental reservoir on farms that raise chickens, might explain how multiple PFGE patterns were linked to chicken from 3 separate production establishments and many different poultry products.

The characteristics of summer sub-hourly rainfall over the southern UK in a high-resolution convective permitting model

Flash flooding is often caused by sub-hourly rainfall extremes. Here, we examine southern UK sub-hourly 10 min rainfall from Met Office state-of-the-art convective-permitting model simulations for the present and future climate. Observational studies have shown that the duration of rainfall can decrease with temperature in summer in some regions. The duration decrease coincides with an intensification of sub-hourly rainfall extremes. This suggests that rainfall duration and sub-hourly rainfall intensity may change in future under climate change with important implications for future changes in flash flooding risk. The simulations show clear intensification of sub-hourly rainfall, but we fail to detect any decrease in rainfall duration. In fact, model results suggest the opposite with a slight (probably insignificant) lengthening of both extreme and non-extreme rainfall events in the future. The lengthening is driven by rainfall intensification without clear changes in the shape of the event profile. Other metrics are also examined, including the relationship between intense 10 min rainfall and temperature, and return levels changes; all are consistent with results found for hourly rainfall. No evaluation of model performance at the sub-hourly timescale is possible, highlighting the need for high-quality sub-hourly observations. Such sub-hourly observations will advance our understanding of the future risks of flash flooding.