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Soil porosity and its reciprocal bulk density are important environmental state variables that enable modelers to represent hydraulic function and carbon storage. Biotic effects and their 'dynamic' influence on such state variables remain largely unknown for larger scales and may result in important, yet poorly quantified environmental feedbacks. Existing representation of hydraulic function is often invariant to environmental change and may be poor in some systems, particularly non-arable soils. Here we assess predictors of total porosity across two comprehensive national topsoil (0-15 cm) data sets, covering the full range of soil organic matter (SOM) and habitats (n = 1385 & n = 2570), using generalized additive mixed models and machine learning. Novel aspects of this work include the testing of metrics on aggregate size and livestock density alongside a range of different particle size distribution metrics. We demonstrate that porosity trends in Great Britain are dominated by biotic metrics, soil carbon and land use. Incorporating these variables into porosity prediction improves performance, paving the way for new dynamic calculation of porosity using surrogate measures with remote sensing, which may help improve prediction in data sparse regions of the world. Moreover, dynamic calculation of porosity could support representation of feedbacks in environmental and Earth System Models. Representing the hydrological feedbacks from changes in structural porosity also requires data and models at appropriate spatial scales to capture conditions leading to near-saturated soil conditions. Classification. Environmental Sciences.

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The thin layer of soil at the earth's surface supports life, storing water and nutrients for plant uptake. These processes occur in the soil pore space, often half the soil volume, but our understanding of how this volume responds to environmental change is poor. Convention, has been to predict soil porosity, or its reciprocal bulk density (BD), from soil texture using pedotransfer functions (PTFs). A texture based approach, invariant to environmental change, prevents feedback from land use or climate change to soil porosity. Moreover, PTFs are often limited to mineral soils with < 20% soil organic matter (SOM) content. Here, we develop an analytical model to predict soil porosity, or BD, as a function of SOM. We test it on two comprehensive, methodologically consistent, temperate national-scale topsoil data sets (0-15 cm) (Wales, n = 1385; Great Britain, n = 2570). The purpose of the approach is to generate an analytical function suitable for predicting soil porosity change with SOM content, while providing insight into the main grain-scale factors determining the porosity emergence. The newly developed function covering the entire SOM gradient allows for impacts of land use, management or climate change to feedback on soil porosity or bulk density through decadal dynamic changes in SOM.

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Soil organic carbon (SOC) concentration is the fundamental indicator of soil health, underpinning food production and climate change mitigation. SOC storage is highly sensitive to several dynamic environmental drivers, with approximately one third of soils degraded and losing carbon worldwide. Digital soil mapping illuminates where hotspots of SOC storage occur and where losses to the atmosphere are most likely. Yet, attempts to map SOC often disagree. Here we compare national scale SOC concentration map products to reveal agreement of data in mineral soils, with progressively poorer agreement in organo-mineral and organic soils. Divergences in map predictions from each other and survey data widen in the high SOC content land types we stratified. Given the disparities are highest in carbon rich soils, efforts are required to reduce these uncertainties to increase confidence in mapping SOC storage and predicting where change may be important at national to global scales. Our map comparison results could be used to identify SOC risk where concentrations are high and should be conserved, and where uncertainty is high and further monitoring should be targeted. Reducing inter-map uncertainty will rely on addressing statistical limitations and including covariates that capture convergence of physical factors that produce high SOC contents.

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The UK Countryside Survey (CS) is a national long-term survey of soils and vegetation that spans three decades (1978-2007). Past studies using CS data have identified clear contrasting trends in topsoil organic carbon (tSOC) concentrations (0-15 cm) related to differences between habitat types. Here we firstly examine changes in tSOC resulting from land use change, and secondly construct mixed models to describe the impact of indirect drivers where land use has been constant. Where it occurs, land use change is a strong driver of SOC change, with largest changes in tSOC for transitions involving SOC-rich soils in upland and bog systems. Afforestation did not always increase tSOC, and the effect of transitions involving woodland was dependent on the other vegetation type. The overall national spatial pattern of tSOC concentration where land use has been constant is most strongly related to vegetation type and topsoil pH, with contributions from climate variables, deposition and geology. Comparisons of models for tSOC across time periods suggest that declining SO4 deposition has allowed recovery of topsoils from acidification, but that this has not resulted in the increased decomposition rates and loss of tSOC which might be expected. As a result, the relationship between pH and tSOC in UK topsoils has changed significantly between 1978 and 2007. The contributions of other indirect drivers in the models suggest negative relationships to seasonal temperature metrics and positive relationships to seasonal precipitation at the dry end of the scale. The results suggest that the CS approach of long-term collection of co-located vegetation and soil biophysical data provides essential tools both for identifying trends in tSOC at national and habitat levels, and for identifying areas of risk or areas with opportunities for managing topsoil SOC and vegetation change.

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The majority of the Earth's terrestrial carbon is stored in the soil. If anthropogenic warming stimulates the loss of this carbon to the atmosphere, it could drive further planetary warming. Despite evidence that warming enhances carbon fluxes to and from the soil, the net global balance between these responses remains uncertain. Here we present a comprehensive analysis of warming-induced changes in soil carbon stocks by assembling data from 49 field experiments located across North America, Europe and Asia. We find that the effects of warming are contingent on the size of the initial soil carbon stock, with considerable losses occurring in high-latitude areas. By extrapolating this empirical relationship to the global scale, we provide estimates of soil carbon sensitivity to warming that may help to constrain Earth system model projections. Our empirical relationship suggests that global soil carbon stocks in the upper soil horizons will fall by 30 ± 30 petagrams of carbon to 203 ± 161 petagrams of carbon under one degree of warming, depending on the rate at which the effects of warming are realized. Under the conservative assumption that the response of soil carbon to warming occurs within a year, a business-as-usual climate scenario would drive the loss of 55 ± 50 petagrams of carbon from the upper soil horizons by 2050. This value is around 12-17 per cent of the expected anthropogenic emissions over this period. Despite the considerable uncertainty in our estimates, the direction of the global soil carbon response is consistent across all scenarios. This provides strong empirical support for the idea that rising temperatures will stimulate the net loss of soil carbon to the atmosphere, driving a positive land carbon-climate feedback that could accelerate climate change.

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BACKGROUND: Identifying fall-related injuries and costs using healthcare claims data is cost-effective and easier to implement than using medical records or patient self-report to track falls. We developed a comprehensive four-step algorithm for identifying episodes of care for fall-related injuries and associated costs, using fee-for-service Medicare and Medicare Advantage health plan claims data for 2,011 patients from 5 medical groups between 2005 and 2009. METHODS: First, as a preparatory step, we identified care received in acute inpatient and skilled nursing facility settings, in addition to emergency department visits. Second, based on diagnosis and procedure codes, we identified all fall-related claim records. Third, with these records, we identified six types of encounters for fall-related injuries, with different levels of injury and care. In the final step, we used these encounters to identify episodes of care for fall-related injuries. RESULTS: To illustrate the algorithm, we present a representative example of a fall episode and examine descriptive statistics of injuries and costs for such episodes. Altogether, we found that the results support the use of our algorithm for identifying episodes of care for fall-related injuries. When we decomposed an episode, we found that the details present a realistic and coherent story of fall-related injuries and healthcare services. Variation of episode characteristics across medical groups supported the use of a complex algorithm approach, and descriptive statistics on the proportion, duration, and cost of episodes by healthcare services and injuries verified that our results are consistent with other studies. CONCLUSIONS: This algorithm can be used to identify and analyze various types of fall-related outcomes including episodes of care, injuries, and associated costs. Furthermore, the algorithm can be applied and adopted in other fall-related studies with relative ease.

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BACKGROUND: The aim of this study was to explore the effect of kidney transplantation (KT) on psychological distress and quality of life (QoL) in patients with end-stage kidney disease using the Common Sense Model of illness adjustment. MATERIALS AND METHODS: A total of 52 individuals (35 men and 17 women) with an average age of 53.54 years from a large metropolitan nephrology outpatient clinic participated. RESULTS: Poorer health status, illness perceptions and increased engagement in maladaptive coping were associated with psychological distress (specifically anxiety and depression) and poorer QoL. Hierarchical regression, after correcting for KT characteristics (years since most recent KT, number of transplants) indicated that poorer illness status and illness perception predicted QoL. After controlling for KT characteristics, poorer illness status and greater engagement in maladaptive coping predicted depression. In contrast, poorer illness perceptions and greater engagement in maladaptive coping predicted anxiety. Adaptive problem-focused and emotion-focused coping styles were not found to predict anxiety, depression or QoL. CONCLUSIONS: The finding of the present study emphasize on the importance of exploring and understanding the effect of illness status, illness perceptions and coping patterns in patients who have underwent KT.

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BACKGROUND: Appendectomy remains the gold standard in the treatment of acute, uncomplicated appendicitis in the United States. Nonetheless, there is growing evidence that nonoperative management is safe and efficacious. METHODS: We constructed a decision tree to compare nonoperative management of appendicitis with laparoscopic appendectomy in otherwise healthy adults. Model variables were abstracted from a literature review, data from the Healthcare Cost and Utilization Project data, the Medicare Physician Fee schedule, and the American College of Surgeons Surgical Risk Calculator. Uncertainty surrounding parameters of the model was assessed via 1-way and probabilistic sensitivity analyses. RESULTS: Operative management cost $12,213 per patient. Nonoperative management without interval appendectomy (IA) was the dominant strategy, costing $1,865 less and producing 0.03 more quality-adjusted life-years (QALYs). Nonoperative management with IA cost $4,271 more than operative management, but yielded only 0.01 additional QALY. One-way sensitivity analysis suggested operative management would become the preferred strategy if the recurrence rate was >40.5% or the total cost of appendectomy was decreased to <$5,468. Probabilistic sensitivity analysis confirmed nonoperative management without IA was the preferred strategy in 95.6% of cases. CONCLUSION: Nonoperative management without IA is the least costly, most effective treatment for acute, uncomplicated appendicitis and warrants further evaluation in a disease thought to be definitively surgical.

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OBJECTIVES: To determine whether a program that improves the quality of care for falls reduces the number of episodes of care for serious fall-related injuries. DESIGN: Nonrandomized controlled trial. SETTING: Four community-based primary care practices. PARTICIPANTS: Individuals aged 75 and older who screened positive for fall risk. INTERVENTION: A multicomponent quality improvement program (Assessing Care of Vulnerable Elders Practice Redesign for Improved Medical Care for Elders) involving face-to-face clinician education about falls and decision support to prompt primary care providers to implement appropriate care, including referral to appropriate community resources, in response to individuals screening positive for fall risk. MEASUREMENTS: Episodes of care for selected fall-related injuries, based on healthcare claims. RESULTS: Of 1,791 individuals with data available for analysis, 1,187 were in the intervention group, and 604 were in the control group. Mean age was 83, and more than two-thirds of the sample were women. After adjusting for potential confounders, there were no statistically significant differences between intervention and control groups in episodes of care for fall-related injuries during the 12-month (incidence rate ratio (IRR) 1.27, 95% confidence interval (CI) = 0.93-1.73) or 24-month (IRR 1.18, 95% CI = 0.93-1.49) period after initiation of the intervention. CONCLUSION: Despite improving the care of falls, this quality improvement initiative did not result in a change in the number of episodes of care for serious fall-related injuries. Future work in community-based settings should test higher-intensity interventions to reduce fall-related injuries.

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BACKGROUND: The National Lung Screening Trial (NLST) showed that screening with low-dose computed tomography (CT) as compared with chest radiography reduced lung-cancer mortality. We examined the cost-effectiveness of screening with low-dose CT in the NLST. METHODS: We estimated mean life-years, quality-adjusted life-years (QALYs), costs per person, and incremental cost-effectiveness ratios (ICERs) for three alternative strategies: screening with low-dose CT, screening with radiography, and no screening. Estimations of life-years were based on the number of observed deaths that occurred during the trial and the projected survival of persons who were alive at the end of the trial. Quality adjustments were derived from a subgroup of participants who were selected to complete quality-of-life surveys. Costs were based on utilization rates and Medicare reimbursements. We also performed analyses of subgroups defined according to age, sex, smoking history, and risk of lung cancer and performed sensitivity analyses based on several assumptions. RESULTS: As compared with no screening, screening with low-dose CT cost an additional $1,631 per person (95% confidence interval [CI], 1,557 to 1,709) and provided an additional 0.0316 life-years per person (95% CI, 0.0154 to 0.0478) and 0.0201 QALYs per person (95% CI, 0.0088 to 0.0314). The corresponding ICERs were $52,000 per life-year gained (95% CI, 34,000 to 106,000) and $81,000 per QALY gained (95% CI, 52,000 to 186,000). However, the ICERs varied widely in subgroup and sensitivity analyses. CONCLUSIONS: We estimated that screening for lung cancer with low-dose CT would cost $81,000 per QALY gained, but we also determined that modest changes in our assumptions would greatly alter this figure. The determination of whether screening outside the trial will be cost-effective will depend on how screening is implemented. (Funded by the National Cancer Institute; NLST ClinicalTrials.gov number, NCT00047385.).

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Plant production is a key process in semi-natural ecosystems, affecting resource provision, carbon storage, and habitat suitability for species of conservation concern. There is debate over whether nitrogen (N) or phosphorus (P) limits productivity more widely, and whether the pattern of limitation has been affected by widespread atmospheric N pollution. In a national-scale survey, floristic composition was used to derive mean Ellenberg N score (EN) for use as an independent metric of productivity. Much of the variation in EN within extensively-managed habitats could be explained by bulk-soil properties such as total C and moisture contents, reflecting the axis from wet, organic, infertile soils to drier, mineral, fertile soils. However, this main axis of variation was also explained well by bicarbonate-extractable P stock, and P stock was included in the best 88 of 255 possible models for all habitats, or the best 55 of 255 models for extensively-managed habitats. The stock of mineralisable N was much less well able to explain variation in the productivity metric, particularly in extensively-managed habitats. This suggests that P availability is a more widespread constraint to the productivity of semi-natural ecosystems in the UK than is N availability.

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Despite rapid growth in the rate of adoption of health information technology (HIT), and in the volume of evaluation studies, the existing knowledge base for the value of HIT is not advancing at a similar rate. Most evaluation articles are limited in that they use incomplete measures of value and fail to report the important contextual and implementation characteristics that would allow for an adequate understanding of how the study results were achieved. To address these deficiencies, we present a conceptual framework for measuring HIT value and we propose a checklist of characteristics that should be considered in HIT evaluation studies. The framework consists of 3 key principles: 1) value includes both costs and benefits; 2) value accrues over time; and 3) value depends on which stakeholder's perspective is used. Through examples, we show how these principles can be used to guide and improve HIT evaluation studies. The checklist includes a list of contextual and implementation characteristics that are important for interpretation of results. These improvements will make future studies more useful for policy makers and more relevant to the current needs of the healthcare system.

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New medical technologies are a leading driver of U.S. health care spending. This article identifies promising policy options to change which medical technologies are created, with two related policy goals: (1) Reduce total health care spending with the smallest possible loss of health benefits, and (2) ensure that new medical products that increase spending are accompanied by health benefits that are worth the spending increases. The analysis synthesized information from peer-reviewed and other literature, a panel of technical advisors convened for the project, and 50 one-on-one expert interviews. The authors also conducted case studies of eight medical products. The following features of the U.S. health care environment tend to increase spending without also conferring major health benefits: lack of basic scientific knowledge about some disease processes, costs and risks of U.S. Food and Drug Administration (FDA) approval, limited rewards for medical products that could lower spending, treatment creep, and the medical arms race. The authors identified ten policy options that would help advance the two policy goals. Five would do so by reducing the costs and/or risks of invention and obtaining FDA approval: (1) Enable more creativity in funding basic science, (2) offer prizes for inventions, (3) buy out patents, (4) establish a public-interest investment fund, and (5) expedite FDA reviews and approvals. The other five options would do so by increasing market rewards for products: (1) Reform Medicare payment policies, (2) reform Medicare coverage policies, (3) coordinate FDA approval and Centers for Medicare & Medicaid Services coverage processes, (4) increase demand for technologies that decrease spending, and (5) produce more and more-timely technology assessments.

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Countryside Survey is a unique large scale long-term monitoring programme investigating stock and change of habitats, landscape features, vegetation, soil and freshwaters of Great Britain. Repeat field surveys combine policy and scientific objectives to provide evidence on how multiple aspects of the environment are changing over time, a key goal of international science in the face of profound human impacts on ecosystems. Countryside Survey 2007 (CS2007), the fifth survey since 1978, retained consistency with previous surveys, whilst evolving in line with technological and conceptual advances in the collection and integration of data to understand landscape change. This paper outlines approaches taken in the 2007 survey and its subsequent analysis and presents some of the headline results of the survey and their relevance for national and international policy objectives. Key changes between 1998 and 2007 included: a) significant shifts in agricultural land cover from arable to grassland, accompanied by increases in the area of broadleaved woodland, b) decreases in the length of managed hedges associated with agricultural land, as a proportion deteriorated to lines of trees and c) increases in the areas and numbers of wet habitats (standing open water, ponds) and species preferring wetter conditions (1998-2007 and 1978-2007). Despite international policy directed at maintaining and enhancing biodiversity, there were widespread decreases in species richness in all linear and area habitats, except on arable land, consistent with an increase in competitive and late successional species between 1998 and 2007 and 1978 and 2007. Late successional and competitive species: Stinging nettle (Urtica dioica), Hawthorn (Cratageous monogyna) and Bramble (Rubus fruticosus), in the top ten recorded species recorded in 2007, all increased between 1998 and 2007. The most commonly recorded species in CS (1990, 1998 and 2007) was agricultural Ryegrass (Lolium perenne). Increases in both water quality and soil pH were in line with policy aimed at addressing previous deterioration of both. Headwater streams broadly showed continued improvements in biological quality from 1998 to 2007, continuing trends seen since 1990. In soils, there were significant increases in soil pH between 1998 and 2007 consistent with recovery from acidification.

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Effects of anthropogenic nitrogen (N) deposition and the ability of terrestrial ecosystems to store carbon (C) depend in part on the amount of N retained in the system and its partitioning among plant and soil pools. We conducted a meta-analysis of studies at 48 sites across four continents that used enriched 15N isotope tracers in order to synthesize information about total ecosystem N retention (i.e., total ecosystem 15N recovery in plant and soil pools) across natural systems and N partitioning among ecosystem pools. The greatest recoveries of ecosystem 15N tracer occurred in shrublands (mean, 89.5%) and wetlands (84.8%) followed by forests (74.9%) and grasslands (51.8%). In the short term (< 1 week after 15N tracer application), total ecosystem 15N recovery was negatively correlated with fine-root and soil 15N natural abundance, and organic soil C and N concentration but was positively correlated with mean annual temperature and mineral soil C:N. In the longer term (3-18 months after 15N tracer application), total ecosystem 15N retention was negatively correlated with foliar natural-abundance 15N but was positively correlated with mineral soil C and N concentration and C:N, showing that plant and soil natural-abundance 15N and soil C:N are good indicators of total ecosystem N retention. Foliar N concentration was not significantly related to ecosystem 15N tracer recovery, suggesting that plant N status is not a good predictor of total ecosystem N retention. Because the largest ecosystem sinks for 15N tracer were below ground in forests, shrublands, and grasslands, we conclude that growth enhancement and potential for increased C storage in aboveground biomass from atmospheric N deposition is likely to be modest in these ecosystems. Total ecosystem 15N recovery decreased with N fertilization, with an apparent threshold fertilization rate of 46 kg N x ha(-1) x yr(-1) above which most ecosystems showed net losses of applied 15N tracer in response to N fertilizer addition.

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Fertilization represents the culmination of a series of complex interactions between male and female gametes. Despite advances in our understanding, the precise molecular mechanisms underlying these fundamental interactions remain largely uncharacterized. There is however growing recognition that this process requires the concerted action of multiple sperm receptors that possess affinity for complementary zona pellucida ligands and those that reside on the surface of the oolemma. Among the candidate sperm proteins that have been implicated in fertilization, those belonging to the ADAM (a disintegrin and metalloprotease) family of proteases have received considerable attention. The focus of the studies described herein has been the characterization of a closely related member of this protease family, ADAMTS10 (a disintegrin and metalloprotease with thrombospondin type 1 motifs number 10). We have demonstrated that ADAMTS10 is expressed during the later stages of mouse spermatogenesis and incorporated into the acrosomal domain of developing spermatids. During sperm maturation, the protein appears to be processed before being expressed on the surface of the peri-acrosomal region of the head. Our collective data suggest that, from this position, ADAMTS10 participates in sperm adhesion to the zona pellucida. Indeed, pre-incubation of capacitated spermatozoa with either galardin, a broad spectrum inhibitor of metalloprotease activity, or anti-ADAMTS10 antisera elicited a significant reduction in their ability to engage in zona adhesion. Overall, these studies support the notion that sperm-oocyte interactions involve considerable functional redundancy and identify ADAMTS10 as a novel candidate in the mediation of these fundamentally important events.

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The amount of plant-available nitrogen (N) in soil is an important indicator of eutrophication of semi-natural habitats, but previous studies have shown contrasting effects of N deposition on mineralisable N in different habitats. The stock of readily mineralisable N (N(rm)) was measured in 665 locations across Britain from a range of intensively and extensively managed habitats, allowing N availability to be studied in relation to soil and vegetation type, and also to variation in climate and in reactive N deposition from the atmosphere. Mineralisable N contents were correlated with deposition in extensively managed habitats but not in intensively managed habitats. The following statements apply only to extensively managed habitats. All habitats showed a similar increase in N(rm) with N deposition. However, soil characteristics affected the relationship, and soil carbon content in particular was a major control on mineralisation. The N(rm) stock increased more with N deposition in organic than in mineral soils. The nitrate proportion of N(rm) also increased with N deposition but, conversely, this increase was greater in mineral than in organic soils. The measurements could be used as indicators of eutrophication, e.g. deposition rates of over 20 kg N ha(-1) y(-1) are associated with nitrate proportions of >41% in a mineral soil (2% carbon), and with N(rm) stocks of over 4.8 kg N ha(-1) in an organic soil (55% carbon). Both N(rm) and nitrate proportion increased with mean annual temperature of the sampling location, despite consistent incubation temperature, suggesting that increasing temperatures are likely to increase the eutrophying effects of N pollution on semi-natural ecosystems.

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Falls are a major health concern for elderly people and cause substantial health care costs. The authors used meta-analytic findings on the effectiveness of fall prevention interventions to determine cost-effectiveness of a proposed Medicare fall prevention program for people who experience a recent fall. Using published clinical trial data, the authors constructed a population-based economic model and estimated that, in the base case, the program could prevent a half million people from falling again within a year. From the model, under most circumstances the cost-effectiveness ratio is less than $1500 per person prevented from experiencing a recurrent fall. Paying for a fall prevention program to increase the use of evidence-based interventions would be a cost-effective use of Medicare dollars.

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OBJECTIVE: To examine whether physicians' use of information technology (IT) was associated with better knowledge of drug costs. STUDY DESIGN/METHODS: A 2007 statewide survey of 247 primary care physicians in Hawaii regarding IT use and self-reported knowledge of formularies, copayments, and retail prices. RESULTS: Approximately 8 in 10 physicians regularly used IT in clinical care: 60% Internet, 54% e-prescribing, 43% electronic health records (EHRs), and 37% personal digital assistants (PDAs). However, fewer than 1 in 5 often knew drug costs when prescribing, and more than 90% said lack of knowledge of formularies and copayments remained a barrier to considering drug costs for patients. In multivariate analyses adjusting for sex, practice size, years in practice, number of formularies, and use of clinical resources (eg, pharmacists), use of the Internet -- but not e-prescribing, EHRs, or PDAs -- was associated with physicians reporting slightly better knowledge of copayments (adjusted predicted percentage of 23% vs 11%; P = .04). No type of IT was associated with better knowledge of formularies or retail prices. CONCLUSIONS: Despite high rates of IT use, there was only a modest association between physicians' use of IT and better knowledge of drug costs. Future investments in health IT should consider how IT design can be improved to make it easier for physicians to access cost information at the point of care.

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