P-FLUX: A phosphorus budget dataset spanning diverse agricultural production systems in the United States and Canada.

Quantifying spatial and temporal fluxes of phosphorus (P) within and among agricultural production systems is critical for sustaining agricultural production while minimizing environmental impacts. To better understand P fluxes in agricultural landscapes, P-FLUX, a detailed and harmonized dataset of P inputs, outputs, and budgets, as well as estimated uncertainties for each P flux and budget, was developed. Data were collected from 24 research sites and 61 production systems through the Long-term Agroecosystem Research (LTAR) network and partner organizations spanning 22 U.S. states and 2 Canadian provinces. The objectives of this paper are to (a) present and provide a description of the P-FLUX dataset, (b) provide summary analyses of the agricultural production systems included in the dataset and the variability in P inputs and outputs across systems, and (c) provide details for accessing the dataset, dataset limitations, and an example of future use. P-FLUX includes information on select site characteristics (area, soil series), crop rotation, P inputs (P application rate, source, timing, placement, P in irrigation water, atmospheric deposition), P outputs (crop removal, hydrologic losses), P budgets (agronomic budget, overall budget), uncertainties associated with each flux and budget, and data sources. Phosphorus fluxes and budgets vary across agricultural production systems and are useful resources to improve P use efficiency and develop management strategies to mitigate environmental impacts of agricultural systems. P-FLUX is available for download through the USDA Ag Data Commons (https://doi.org/10.15482/USDA.ADC/1523365).

[Decision-making support in Intensive Care to facilitate organ donation : Position paper of the Ethics Section and the Organ Donation and Transplantation Section of the German Interdisciplinary Association of Critical Care and Emergency Medicine (DIVI) in collaboration with the Ethics Section of the German Society of Medical Intensive Care Medicine and Emergency Medicine (DGIIN)]. / Entscheidungshilfe bei erweitertem intensivmedizinischem Behandlungsbedarf auf dem Weg zur Organspende : Positionspapier der Sektion Ethik und der Sektion Organspende und -transplantation der Deutschen Interdisziplinären Vereinigung für Intensiv- und Notfallmedizin (DIVI) unter Mitarbeit der Sektion Ethik der Deutschen Gesellschaft für Internistische Intensivmedizin und Notfallmedizin (DGIIN).

BACKGROUND AND CHALLENGE: Injuries, especially traumatic brain injury, or specific illnesses and their respective sequelae can result in the demise of the patients afflicted despite all efforts of modern intensive care medicine. If in principle organ donation is an option after a patient's death, intensive therapeutic measures are regularly required in order to maintain the homeostasis of the organs. These measures, however, cannot benefit the patient afflicted anymore-which in turn might lead to an ethical conflict between dignified palliative care for him/her and expanded intensive treatment to facilitate organ donation for others, especially if the patient has opted for the limitation of life-sustaining therapies in an advance directive. METHOD: The Ethics Section and the Organ Donation and Transplantation Section of the German Interdisciplinary Association of Critical Care and Emergency Medicine (DIVI) have convened several meetings and a telephone conference and have arrived at a decision-making aid as to the extent of treatment for potential organ donors. This instrument focusses first on the assessment of five individual dimensions regarding organ donation, namely the certitude of a complete and irreversible loss of all brain function, the patient's wishes as to organ donation, his or her wishes as to limiting life-sustaining therapies, the intensity of expanded intensive treatment for organ protection and the odds of its successful attainment. Then, the combination of the individual assessments, as graphically shown in a {Netzdiagramm}, will allow for a judgement as to whether a continuation or possibly an expansion of intensive care measures is ethically justified, questionable or even inappropriate. RESULT: The aid described can help mitigate ethical conflicts as to the extent of intensive care treatment for moribund patients, when organ donation is a medically sound option. NOTE: Gerald Neitzke und Annette Rogge contributed equally to this paper and should be considered co-first authors.

[Amendment to the documentation of decisions to withhold or withdraw life-sustaining therapies in consideration of wish to donate organs : Recommendation of the Ethics Section and the Organ Donation and Transplantation Section of the German Interdisciplinary Association of Critical Care and Emergency Medicine (DIVI) in collaboration with the Ethics Section of the German Society of Medical Intensive Care Medicine and Emergency Medicine (DGIIN)]. / Ergänzung des Dokumentationsbogens "Therapiebegrenzung" unter Berücksichtigung eines möglichen Organspendewunsches : Empfehlung der Sektion Ethik sowie der Sektion Organspende und Organtransplantation der Deutschen Interdisziplinären Vereinigung für Intensiv- und Notfallmedizin (DIVI) unter Mitarbeit der Sektion Ethik der Deutschen Gesellschaft für Internistische Intensivmedizin und Notfallmedizin (DGIIN).

The Ethics Section of the German Interdisciplinary Association of Critical Care and Emergency Medicine (DIVI) recently published a documentation for decisions to withhold or withdraw life-sustaining therapies. The wish to donate organs was not considered explicitly. Therefore the Ethics Section and the Organ Donation and Transplantation Section of the DIVI together with the Ethics Section of the German Society of Medical Intensive Care Medicine and Emergency Medicine worked out a supplementary footnote for the documentation form to address the individual case of a patient's wish to donate organs.

Advancing the Sustainability of US Agriculture through Long-Term Research.

Agriculture in the United States must respond to escalating demands for productivity and efficiency, as well as pressures to improve its stewardship of natural resources. Growing global population and changing diets, combined with a greater societal awareness of agriculture's role in delivering ecosystem services beyond food, feed, fiber, and energy production, require a comprehensive perspective on where and how US agriculture can be sustainably intensified, that is, made more productive without exacerbating local and off-site environmental concerns. The USDA's Long-Term Agroecosystem Research (LTAR) network is composed of 18 locations distributed across the contiguous United States working together to integrate national and local agricultural priorities and advance the sustainable intensification of US agriculture. We explore here the concept of sustainable intensification as a framework for defining strategies to enhance production, environmental, and rural prosperity outcomes from agricultural systems. We also elucidate the diversity of factors that have shaped the past and present conditions of cropland, rangeland, and pastureland agroecosystems represented by the LTAR network and identify priorities for research in the areas of production, resource conservation and environmental quality, and rural prosperity. Ultimately, integrated long-term research on sustainable intensification at the national scale is critical to developing practices and programs that can anticipate and address challenges before they become crises.

Simulated Soil Organic Carbon Responses to Crop Rotation, Tillage, and Climate Change in North Dakota.

Understanding how agricultural management and climate change affect soil organic carbon (SOC) stocks is particularly important for dryland agriculture regions that have been losing SOC over time due to fallow and tillage practices, and it can lead to development of agricultural practice(s) that reduce the impact of climate change on crop production. The objectives of this study were: (i) to simulate SOC dynamics in the top 30 cm of soil during a 20-yr (1993-2012) field study using CQESTR, a process-based C model; (ii) to predict the impact of changes in management, crop production, and climate change from 2013 to 2032; and (iii) to identify the best dryland cropping systems to maintain or increase SOC stocks under projected climate change in central North Dakota. Intensifying crop rotations was predicted to have a greater impact on SOC stocks than tillage (minimum tillage [MT], no-till [NT]) during 2013 to 2032, as SOC was highly correlated to biomass input ( = 0.91, = 0.00053). Converting from a MT spring wheat (SW, L.)-fallow rotation to a NT continuous SW rotation increased annualized biomass additions by 2.77 Mg ha (82%) and SOC by 0.22 Mg C ha yr. Under the assumption that crop production will stay at the 1993 to 2012 average, climate change is predicted to have a minor impact on SOC (approximately -6.5%) relative to crop rotation management. The CQESTR model predicted that the addition of another SW or rye ( L.) crop would have a greater effect on SOC stocks (0- to 30-cm depth) than conversion from MT to NT or climate change from 2013 to 2032.

Introducing the GRACEnet/REAP Data Contribution, Discovery, and Retrieval System.

Difficulties in accessing high-quality data on trace gas fluxes and performance of bioenergy/bioproduct feedstocks limit the ability of researchers and others to address environmental impacts of agriculture and the potential to produce feedstocks. To address those needs, the GRACEnet (Greenhouse gas Reduction through Agricultural Carbon Enhancement network) and REAP (Renewable Energy Assessment Project) research programs were initiated by the USDA Agricultural Research Service (ARS). A major product of these programs is the creation of a database with greenhouse gas fluxes, soil carbon stocks, biomass yield, nutrient, and energy characteristics, and input data for modeling cropped and grazed systems. The data include site descriptors (e.g., weather, soil class, spatial attributes), experimental design (e.g., factors manipulated, measurements performed, plot layouts), management information (e.g., planting and harvesting schedules, fertilizer types and amounts, biomass harvested, grazing intensity), and measurements (e.g., soil C and N stocks, plant biomass amount and chemical composition). To promote standardization of data and ensure that experiments were fully described, sampling protocols and a spreadsheet-based data-entry template were developed. Data were first uploaded to a temporary database for checking and then were uploaded to the central database. A Web-accessible application allows for registered users to query and download data including measurement protocols. Separate portals have been provided for each project (GRACEnet and REAP) at nrrc.ars.usda.gov/slgracenet/#/Home and nrrc.ars.usda.gov/slreap/#/Home. The database architecture and data entry template have proven flexible and robust for describing a wide range of field experiments and thus appear suitable for other natural resource research projects.

Grazing management contributions to net global warming potential: a long-term evaluation in the Northern Great Plains.

The role of grassland ecosystems as net sinks or sources of greenhouse gases (GHGs) is limited by a paucity of information regarding management impacts on the flux of nitrous oxide (N(2)O) and methane (CH(4)). Furthermore, no long-term evaluation of net global warming potential (GWP) for grassland ecosystems in the northern Great Plains (NGP) of North America has been reported. Given this need, we sought to determine net GWP for three grazing management systems located within the NGP. Grazing management systems included two native vegetation pastures (moderately grazed pasture [MGP], heavily grazed pasture [HGP]) and a heavily grazed crested wheatgrass [Agropyron desertorum (Fisch. ex. Link) Schult.] pasture (CWP) near Mandan, ND. Factors evaluated for their contribution to GWP included (i) CO(2) emissions associated with N fertilizer production and application, (ii) literature-derived estimates of CH(4) production for enteric fermentation, (iii) change in soil organic carbon (SOC) over 44 yr using archived soil samples, and (iv) soil-atmosphere N(2)O and CH(4) fluxes over 3 yr using static chamber methodology. Analysis of SOC indicated all pastures to be significant sinks for SOC, with sequestration rates ranging from 0.39 to 0.46 Mg C ha(-1) yr(-1). All pastures were minor sinks for CH(4) (<2.0 kg CH(4)-C ha(-1) yr(-1)). Greater N inputs within CWP contributed to annual N(2)O emission nearly threefold greater than HGP and MGP. Due to differences in stocking rate, CH(4) production from enteric fermentation was nearly threefold less in MGP than CWP and HGP. When factors contributing to net GWP were summed, HGP and MGP were found to serve as net CO(2equiv.) sinks, while CWP was a net CO(2equiv.) source. Values for GWP and GHG intensity, however, indicated net reductions in GHG emissions can be most effectively achieved through moderate stocking rates on native vegetation in the NGP.

Effects of the veterinary pharmaceutical ivermectin on soil invertebrates in laboratory tests.

As part of the risk assessment of veterinary pharmaceuticals, the potential impact of these chemicals on soil ecosystems has to be determined according to European law. However, almost no data from standardized laboratory tests are available. Therefore, in the EU FP6 ERAPharm, the effects of the widely used veterinary pharmaceutical ivermectin, an anthelminthic, were studied in chronic laboratory tests performed according to OECD (Organisation for Economic Co-operation and Development) and ISO (International Organization for Standardization) guidelines. In detail, three soil invertebrate species--the earthworm Eisenia fetida, the springtail Folsomia candida, and the predatory mite Hypoaspis aculeifer--were tested. The nominal concentrations of ivermectin mixed into the test substrate artificial soil was verified using residue analysis, which indicated that the test substance is persistent for at least up to 28 days. As expected when considering the mode of action of this substance, survival and reproduction of collembolans were clearly affected [LC(50) = 8.4 mg/kg soil dry weight (dw); NOEC(repro) = 0.3 mg/kg soil (dw)]. Predatory mites reacted less sensitively [LC(50) > or = 31.6 mg/kg soil (dw); NOEC(repro) = 3.2 mg/kg soil (dw)]. Earthworm survival and reproduction were affected in the same order of magnitude as the predatory mites [LC(50) > or = 10 mg/kg soil (dw); NOEC(repro) = 2.5 mg/kg soil (dw)]. These results are in good agreement with the few data known from nonstandardized tests for the same or related soil invertebrate species. The results of these tests indicate that the effects of ivermectin on soil invertebrates--in particular, collembolans--cannot be excluded at field-relevant concentrations, as determined in a risk assessment according to VICH guidelines. More sophisticated higher-tier tests (e.g., in multispecies or semifield test systems) are recommended in order to assess the potential risk more accurately.

Modelling long-term ecotoxicological effects on an algal population under dynamic nutrient stress.

We study the effects of toxicants on the functioning of phototrophic unicellular organism (an algae) in a simple aquatic microcosm by applying a parameter-sparse model. The model allows us to study the interaction between ecological and toxicological effects. Nutrient stress and toxicant stress, together or alone, can cause extinction of the algal population. The modelled algae consume dissolved inorganic nitrogen (DIN) under surplus light and use it for growth and maintenance. Dead algal biomass is mineralized by bacterial activity, leading to nutrient recycling. The ecological model is coupled with a toxicity-module that describes the dependency of the algal growth and death rate on the toxicant concentration. Model parameter fitting is performed on experimental data from Liebig, M., Schmidt, G., Bontje, D., Kooi, B.W., Streck, G., Traunspurger, W., Knacker, T. [2008. Direct and indirect effects of pollutants on algae and algivorous ciliates in an aquatic indoor microcosm. Aquatic Toxicology 88, 102-110]. These experiments were especially designed to include nutrient limitation, nutrient recycling and long-term exposure to toxicants. The flagellate species Cryptomonas sp. was exposed to the herbicide prometryn and insecticide methyl parathion in semi-closed Erlenmeyers. Given the total limiting amount of nitrogen in the system, the estimated toxicant concentration at which a long-term steady population of algae goes extinct will be derived. We intend to use the results of this study to investigate the effects of ecological (environmental) and toxicological stresses on more realistic ecosystem structure and functioning.

Model analysis of a simple aquatic ecosystems with sublethal toxic effects.

The dynamic behaviour of simple aquatic ecosystems with nutrient recycling in a chemostat, stressed by limited food availability and a toxicant, is analysed. The aim is to find effects of toxicants on the structure and functioning of the ecosystem. The starting point is an unstressed ecosystem model for nutrients, populations, detritus and their intra- and interspecific interactions, as well as the interaction with the physical environment. The fate of the toxicant includes transport and exchange between the water and the populations via two routes, directly from water via diffusion over the outer membrane of the organism and via consumption of contaminated food. These processes are modelled using mass-balance formulations and diffusion equations. At the population level the toxicant affects different biotic processes such as assimilation, growth, maintenance, reproduction, and survival, thereby changing their biological functioning. This is modelled by taking the parameters that described these processes to be dependent on the internal toxicant concentration. As a consequence, the structure of the ecosystem, that is its species composition, persistence, extinction or invasion of species and dynamics behaviour, steady state oscillatory and chaotic, can change. To analyse the long-term dynamics we use the bifurcation analysis approach. In ecotoxicological studies the concentration of the toxicant in the environment can be taken as the bifurcation parameter. The value of the concentration at a bifurcation point marks a structural change of the ecosystem. This indicates that chemical stressors are analysed mathematically in the same way as environmental (e.g. temperature) and ecological (e.g. predation) stressors. Hence, this allows an integrated approach where different type of stressors are analysed simultaneously. Environmental regimes and toxic stress levels at which no toxic effects occur and where the ecosystem is resistant will be derived. A numerical continuation technique to calculate the boundaries of these regions will be given.

Carnitine supplementation induces long-chain acylcarnitine production--studies in the VLCAD-deficient mouse.

Carnitine supplementation does not affect carnitine concentrations in tissues of wild-type and very long-chain acyl-CoA dehydrogenase-deficient mice, but results in an increase in long-chain acylcarnitine production.