Severe ischaemic colitis secondary to microvenular thrombosis in a hypercoagulable patient.

A young patient with multifactorial prothrombotic risk factors presented with signs and symptoms of ischaemic colitis, without evidence of bowel hypoperfusion on imaging. She deteriorated with trial of conservative management and required operative management. Intraoperative findings demonstrated severe, confluent large bowel necrosis, sparing the rectum. A total colectomy was performed, with return to intensive care unit due to intraoperative hemodynamic instability. A return to theatre the following day allowed for formation of ileostomy and definitive closure. Histopathological findings of microvenular thrombosis were confirmed. Venous causes of ischaemic colitis present diagnostic challenges due to variable presentation and imaging findings. Microvascular venous thrombosis is likely secondary to multifactorial prothrombotic risk factors including positive autoantibodies and variable compliance with warfarin therapy for aortic value replacement. We present this case of ischemic colitis secondary to an unusual aetiology to emphasize the need to remain clinically suspicious of severe abdominal pain despite relatively benign imaging findings.

Identifying genetic variation associated with environmental gradients and drought-tolerance phenotypes in ponderosa pine.

As climate changes, understanding the genetic basis of local adaptation in plants becomes an ever more pressing issue. Combining genotype-environment association (GEA) with genotype-phenotype association (GPA) analysis has an exciting potential to uncover the genetic basis of environmental responses. We use these approaches to identify genetic variants linked to local adaptation to drought in Pinus ponderosa. Over 4 million Single Nucleotide Polymorphisms (SNPs) were identified using 223 individuals from across the Sierra Nevada of California. 927,740 (22.3%) SNPs were retained after filtering for proximity to genes and used in our association analyses. We found 1374 associated with five major climate variables, with the largest number (1151) associated with April 1st snowpack. We also conducted a greenhouse study with various drought-tolerance traits measured in first-year seedlings of a subset of the genotyped trees grown in the greenhouse. 796 SNPs were associated with control-condition trait values, while 1149 were associated with responsiveness of these traits to drought. While no individual SNPs were associated with both the environmental variables and the measured traits, several annotated genes were associated with both, particularly those involved in cell wall formation, biotic and abiotic stress responses, and ubiquitination. However, the functions of many of the associated genes have not yet been determined due to the lack of gene annotation information for conifers. Future studies are needed to assess the developmental roles and ecological significance of these unknown genes.

North American tree migration paced by climate in the West, lagging in the East.

Tree fecundity and recruitment have not yet been quantified at scales needed to anticipate biogeographic shifts in response to climate change. By separating their responses, this study shows coherence across species and communities, offering the strongest support to date that migration is in progress with regional limitations on rates. The southeastern continent emerges as a fecundity hotspot, but it is situated south of population centers where high seed production could contribute to poleward population spread. By contrast, seedling success is highest in the West and North, serving to partially offset limited seed production near poleward frontiers. The evidence of fecundity and recruitment control on tree migration can inform conservation planning for the expected long-term disequilibrium between climate and forest distribution.

Continent-wide tree fecundity driven by indirect climate effects.

Indirect climate effects on tree fecundity that come through variation in size and growth (climate-condition interactions) are not currently part of models used to predict future forests. Trends in species abundances predicted from meta-analyses and species distribution models will be misleading if they depend on the conditions of individuals. Here we find from a synthesis of tree species in North America that climate-condition interactions dominate responses through two pathways, i) effects of growth that depend on climate, and ii) effects of climate that depend on tree size. Because tree fecundity first increases and then declines with size, climate change that stimulates growth promotes a shift of small trees to more fecund sizes, but the opposite can be true for large sizes. Change the depresses growth also affects fecundity. We find a biogeographic divide, with these interactions reducing fecundity in the West and increasing it in the East. Continental-scale responses of these forests are thus driven largely by indirect effects, recommending management for climate change that considers multiple demographic rates.

Simulating the effects of local adaptation and life history on the ability of plants to track climate shifts.

Many studies have examined the impact of dispersal on local adaptation, but much less attention has been paid to how local adaptation influences range shifts. The aim of this study was to test how local adaptation might affect climate-driven range shifts in plants, and if this might differ between plants with different life histories. Simulated range shift dynamics were compared for hypothetical annual, perennial and tree species, each comprised of either one plastic genotype or six locally adapted genotypes. The landscape consists of shifting climate bands made up of 20 × 20 m patches containing multiple individuals. Effects of seed dispersal, breadth of the plastic species' tolerance, steepness of the climate gradient and rate of the climate shift are also examined. Local adaptation increased the equilibrium range size and aided range shifts by boosting fitness near range edges. However, when the rate of climate change was doubled on a steep gradient, locally adapted trees exhibited a higher percent loss of range during the climate shift. The plastic annual species with short dispersal was unable to recover its range size even after the climate stabilized, while the locally adapted annuals tracked climate change well. The results suggest that in most situations local adaptation and longer dispersal distances will be advantageous, though not necessarily sufficient, for tracking suitable climates. However, local adaptation might put species with long generation times at greater risk when climate shifts are very rapid. If confirmed by empirical tests, these results suggest that identifying variation between species in how fitness varies along climate gradients and in these key demographic rates might aid in prioritizing management actions.

Global Disease Burden Estimates of Respiratory Syncytial Virus-Associated Acute Respiratory Infection in Older Adults in 2015: A Systematic Review and Meta-Analysis.

Respiratory syncytial virus-associated acute respiratory infection (RSV-ARI) constitutes a substantial disease burden in older adults aged ≥65 years. We aimed to identify all studies worldwide investigating the disease burden of RSV-ARI in this population. We estimated the community incidence, hospitalization rate, and in-hospital case-fatality ratio (hCFR) of RSV-ARI in older adults, stratified by industrialized and developing regions, using data from a systematic review of studies published between January 1996 and April 2018 and 8 unpublished population-based studies. We applied these rate estimates to population estimates for 2015 to calculate the global and regional burdens in older adults with RSV-ARI in the community and in hospitals for that year. We estimated the number of in-hospital deaths due to RSV-ARI by combining hCFR data with hospital admission estimates from hospital-based studies. In 2015, there were about 1.5 million episodes (95% confidence interval [CI], .3 million-6.9 million) of RSV-ARI in older adults in industrialized countries (data for developing countries were missing), and of these, approximately 14.5% (214 000 episodes; 95% CI, 100 000-459 000) were admitted to hospitals. The global number of hospital admissions for RSV-ARI in older adults was estimated at 336 000 hospitalizations (uncertainty range [UR], 186 000-614 000). We further estimated about 14 000 in-hospital deaths (UR, 5000-50 000) related to RSV-ARI globally. The hospital admission rate and hCFR were higher for those aged ≥65 years than for those aged 50-64 years. The disease burden of RSV-ARI among older adults is substantial, with limited data from developing countries. Appropriate prevention and management strategies are needed to reduce this burden.

Fight or flight? Potential tradeoffs between drought defense and reproduction in conifers.

Plants frequently exhibit tradeoffs between reproduction and growth when resources are limited, and often change these allocation patterns in response to stress. Shorter-lived plants such as annuals tend to allocate relatively more resources toward reproduction when stressed, while longer-lived plants tend to invest more heavily in survival and stress defense. However, severe stress may affect the fitness implications of allocating relatively more resources to reproduction versus stress defense. Increased drought intensity and duration have led to widespread mortality events in coniferous forests. In this review, we ask how potential tradeoffs between reproduction and survival influence the likelihood of drought-induced mortality and species persistence. We propose that trees may exhibit what we call 'fight or flight' behaviors under stress. 'Fight' behaviors involve greater resource allocation toward survival (e.g., growth, drought-resistant xylem and pest defense). 'Flight' consists of higher relative allocation of resources to reproduction, potentially increasing both offspring production and mortality risk for the adult. We hypothesize that flight behaviors increase as drought stress escalates the likelihood of mortality in a given location.

Primary palliative care research: opportunities and challenges.

INTRODUCTION: Primary care has a central role in palliative and end of life care: 45.6% of deaths in England and Wales occur under the care of primary care teams at home or in care homes. The Community Care Pathways at the End of Life (CAPE) study investigated primary care provided for patients in the final 6 months of life. This paper highlights the opportunities and challenges associated with primary palliative care research in the UK, describing the methodological, ethical, logistical and gatekeeping challenges encountered in the CAPE study and how these were addressed. THE STUDY METHODS: Using a mixed-methods approach, quantitative data were extracted from the general practitioner (GP) and district nurse (DN) records of 400 recently deceased patients in 20 GP practices in the East of England. Focus groups were conducted with some GPs and DNs, and individual interviews held with bereaved carers and other GPs and DNs. THE CHALLENGES ADDRESSED: Considerable difficulties were encountered with ethical permissions, with GP, DN and bereaved carer recruitment and both quantitative and qualitative data collection. These were overcome with flexibility of approach, perseverance of the research team and strong user group support. This enabled completion of the study which generated a unique primary palliative care data set.

The genetics of drought tolerance in conifers.

Contents 1034 I. 1034 II. 1035 III. 1037 IV. 1038 V. 1042 VI. 1043 VII. 1045 References 1045 SUMMARY: As temperatures warm and precipitation patterns shift as a result of climate change, interest in the identification of tree genotypes that will thrive under more arid conditions has grown. In this review, we discuss the multiple definitions of 'drought tolerance' and the biological processes involved in drought responses. We describe the three major approaches taken in the study of genetic variation in drought responses, the advantages and shortcomings of each, and what each of these approaches has revealed about the genetic basis of adaptation to drought in conifers. Finally, we discuss how a greater knowledge of the genetics of drought tolerance may aid forest management, and provide recommendations for how future studies may overcome the limitations of past approaches. In particular, we urge a more direct focus on survival, growth and the traits that directly predict them (rather than on proxies, such as water use efficiency), combining research approaches with complementary strengths and weaknesses, and the inclusion of a wider range of taxa and life stages.

Population genetics and adaptation to climate along elevation gradients in invasive Solidago canadensis.

Gene flow between populations may either support local adaptation by supplying genetic variation on which selection may act, or counteract it if maladapted alleles arrive faster than can be purged by selection. Although both such effects have been documented within plant species' native ranges, how the balance of these forces influences local adaptation in invasive plant populations is less clear, in part because introduced species often have lower genetic variation initially but also tend to have good dispersal abilities. To evaluate the extent of gene flow and adaptation to local climate in invasive populations of Solidago canadensis, and the implications of this for range expansion, we compared population differentiation at microsatellite and chloroplast loci for populations across Switzerland and assessed the effect of environmental transfer distance using common gardens. We found that while patterns of differentiation at neutral genetic markers suggested that populations are connected through extensive pollen and seed movement, common-garden plants nonetheless exhibited modest adaptation to local climate conditions. Growth rate and flower production declined with climatic distance from a plant's home site, with clones from colder home sites performing better at or above the range limit. Such adaptation in invasive species is likely to promote further spread, particularly under climate change, as the genotypes positioned near the range edge may be best able to take advantage of lengthening growing seasons to expand the range.

Intraspecific trait variation across scales: implications for understanding global change responses.

Recognition of the importance of intraspecific variation in ecological processes has been growing, but empirical studies and models of global change have only begun to address this issue in detail. This review discusses sources and patterns of intraspecific trait variation and their consequences for understanding how ecological processes and patterns will respond to global change. We examine how current ecological models and theories incorporate intraspecific variation, review existing data sources that could help parameterize models that account for intraspecific variation in global change predictions, and discuss new data that may be needed. We provide guidelines on when it is most important to consider intraspecific variation, such as when trait variation is heritable or when nonlinear relationships are involved. We also highlight benefits and limitations of different model types and argue that many common modeling approaches such as matrix population models or global dynamic vegetation models can allow a stronger consideration of intraspecific trait variation if the necessary data are available. We recommend that existing data need to be made more accessible, though in some cases, new experiments are needed to disentangle causes of variation.

Simulating the Interacting Effects of Intraspecific Variation, Disturbance, and Competition on Climate-Driven Range Shifts in Trees.

Climate change is expected to favor shifts in plant distributions; some such shifts are already being observed along elevation gradients. However, the rate of such shifts may be limited by their ability to reach newly suitable areas and by competition from resident species. The degree of local adaptation and genetic variation may also play a role in the interaction between migrants and residents by affecting relative fitness. We used a simulation model to explore the interacting effects of dispersal, fecundity, disturbance, and genetic variation on range-edge dynamics between a pair of demographically similar tree species. Ideal climate for an individual is determined by genotype. The simulated landscape undergoes an 80-year period of climate change in which climate bands shift upslope; subsequently, climate is held constant for 300 years. The presence of a high-elevation competitor caused a significant lag in the range shift of the low-elevation species relative to competition-free scenarios. Increases in fecundity and dispersal distance both helped to speed up the replacement of the high-elevation species by the low-elevation species at their range boundary. While some disturbance scenarios facilitated this transition, frequent canopy disturbance inhibited colonization by removing reproductive adults and led to range contractions in both species. Differences between dispersal scenarios were more pronounced when disturbance was frequent (15 vs. 25 year return interval) and dispersal was limited. When the high-elevation species lacked genetic variation, its range was more-easily invaded by the low-elevation species, while a similar lack of variation in the low-elevation species inhibited colonization-but only when this lack of variation decreased the fitness of the affected species near the range boundary. Our model results support the importance of measuring and including dispersal/fecundity, disturbance type and frequency, and genetic variation when assessing the potential for range shifts and species vulnerability to climate change.

Evolutionary responses to global change: lessons from invasive species.

Biologists have recently devoted increasing attention to the role of rapid evolution in species' responses to environmental change. However, it is still unclear what evolutionary responses should be expected, at what rates, and whether evolution will save populations at risk of extinction. The potential of biological invasions to provide useful insights has barely been realised, despite the close analogies to species responding to global change, particularly climate change; in both cases, populations encounter novel climatic and biotic selection pressures, with expected evolutionary responses occurring over similar timescales. However, the analogy is not perfect, and invasive species are perhaps best used as an upper bound on expected change. In this article, we review what invasive species can and cannot teach us about likely evolutionary responses to global change and the constraints on those responses. We also discuss the limitations of invasive species as a model and outline directions for future research.

Do the elderly have a voice? Advance care planning discussions with frail and older individuals: a systematic literature review and narrative synthesis.

BACKGROUND: Recent years have seen marked improvements in end-of-life care, however concerns have been expressed that services are focused on the needs of patients with cancer. This review focuses on conversations about end-of-life care with frail and older people who have no main overriding diagnosis who are estimated to account for around 40% of deaths. AIM: To investigate the attitudes of the public and healthcare professionals to advance care planning discussions with frail and older people. DESIGN AND SETTING: Systematic literature review and narrative synthesis. METHOD: Articles that related to frail or older individuals and either advance care plans or discussions on end-of-life care were included. Studies of specific conditions or that focused on prognosis, capacity, or resuscitation decisions were excluded. RESULTS: While a significant minority of frail older individuals would find them unwelcome, the majority would appreciate the chance to discuss end-of-life care, yet most do not have this opportunity. Attitudes to the timing of these discussions were variable, but most perceived the risk of leaving them too late. Most doctors believed it was their professional responsibility to initiate discussions, but felt limited by time pressures and the absence of a precipitating event. A wide range of barriers were identified including the reluctance of family members to discuss end-of-life care, the passive expectation that someone else would decide on an individual's behalf, and significant uncertainty concerning future illness and decline. CONCLUSION: The marked disparity between the majority of older individuals who would like the opportunity to discuss their end-of-life care and the minority that currently have this opportunity raises important questions if the wishes of this large group in society are to be respected. The challenge is to find effective ways of encouraging dialogue and choice within the constraints of the current healthcare systems and personal circumstances.

Can elevated CO2 and ozone shift the genetic composition of aspen (Populus tremuloides) stands?

The world's forests are currently exposed to increasing concentrations of carbon dioxide (CO2) and ozone (O3). Both pollutants can potentially exert a selective effect on plant populations. This, in turn, may lead to changes in ecosystem properties, such as carbon sequestration. Here, we report how elevated CO2 and O3 affect the genetic composition of a woody plant population via altered survival. Using data from the Aspen free-air CO2 enrichment (FACE) experiment (in which aspen clones were grown in factorial combinations of CO2 and O3), we develop a hierarchical Bayesian model of survival. We also examine how survival differences between clones could affect pollutant responses in the next generation. Our model predicts that the relative abundance of the tested clones, given equal initial abundance, would shift under either elevated CO2 or O3 as a result of changing survival rates. Survival was strongly affected by between-clone differences in growth responses. Selection could noticeably decrease O3 sensitivity in the next generation, depending on the heritability of growth responses and the distribution of seed production. The response to selection by CO2, however, is likely to be small. Our results suggest that the changing atmospheric composition could shift the genotypic composition and average pollutant responses of tree populations over moderate timescales.

Effects of plant genotype and insect dispersal rate on the population dynamics of a forest pest.

It has been shown that plant genotype can strongly affect not only individual herbivore performance, but also community composition and ecosystem function. Few studies, however, have addressed how plant genotype affects herbivore population dynamics. In this paper, we used a simulation modeling approach to ask how the genetic composition of a forest influences pest outbreak dynamics, using the example of aspen (Populus tremuloides) and forest tent caterpillars (FTC; Malacosoma disstria). Specifically, we examined how plant genotype, the relative size of genotypic patches, and the rate of insect dispersal between them, affect the frequency, amplitude, and duration of outbreaks. We found that coupling two different genotypes does not necessarily result in an averaging of insect dynamics. Instead, depending on the ratio of patch sizes, when dispersal rates are moderate, outbreaks in the two-genotype case may be more or less severe than in forests of either genotype alone. Thresholds for different dynamic behaviors were similar for all genotypic combinations. Thus, the qualitative behavior of a stand of two different genotypes can be predicted based on the response of the insect to each genotype, the relative sizes of the two patches, and the scale of insect dispersal.

Causes and consequences of unequal seedling production in forest trees: a case study in red oaks.

Inequality in reproductive success has important implications for ecological and evolutionary dynamics, but lifetime reproductive success is challenging to measure in long-lived species such as forest trees. While seed production is often used as a proxy for overall reproductive success, high mortality of seeds and the potential for trade-offs between seed number and quality draw this assumption into question. Parentage analyses of established seedlings can bring us one step closer to understanding the causes and consequences of variation in reproductive success. In this paper we demonstrate a new method for estimating individual seedling production and average percentage germination, using data from two mixed-species populations of red oaks (Quercus rubra, Q. velutina, Q. falcata, and Q. coccinea). We use these estimates to examine the distribution of female reproductive success and to test the relationship between seedling number and individual seed production, age, and growth rate. We show that both seed and seedling production are highly skewed, roughly conforming to zero-inflated lognormal distributions, rather than to the Poisson or negative-binomial distributions often assumed by population genetics analyses. While the number of established offspring is positively associated with mean annual seed production, a lower proportion of seeds from highly fecund individuals become seedlings. Our red oak populations also show evidence of trade-offs between growth rate and reproductive success. The high degree of inequality in seedling production shown here for red oaks, and by previous studies in other species, suggests that many trees may be more vulnerable to genetic drift than previously thought, if immigration in limited by fragmentation or other environmental changes.

Fine specificity and cross-reactions of monoclonal antibodies to group B streptococcal capsular polysaccharide type III.

Group B streptococcus (GBS) is a major cause of neonatal sepsis and meningitis. Despite aggressive campaigns using antenatal prophylactic antibiotic therapy, infections continue. Developing an effective maternal vaccine is a public health priority. Antibody (Ab) to the capsular polysaccharide (CPS) is considered the dominant "protective" immune mediator. Here we study the fine specificity and potential host reactivity of a panel of well-characterized murine monoclonal Abs against the type III CPS by examining the binding of the Abs to intact and neuraminidase-digested GBS, purified CPS, synthetic carbohydrate structures, and cells. The results showed marked differences in the fine specificity among these mAbs to a single carbohydrate structure. Cross-reactions with synthetic GD3 and GT3 carbohydrates, representing structures found on surfaces of neural and developing cells, were demonstrated using carbohydrate array technology. The anti-CPS(III) mAbs did not react with cells expressing GD3 and GT3, nor did mAbs specific for the host carbohydrates cross-react with GBS, raising questions about the physiological relevance of this cross-reaction. But in the process of these investigations, we serendipitously demonstrated cross-reactions of some anti-CPS(III) mAbs with antigens, likely carbohydrates, found on human leukocytes. These studies suggest caution in the development of a maternal vaccine to prevent infection by this important human pathogen.