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Commercially available and cheap disulfides proved to be excellent thiyl-radical sourcesfor the mild desilylation of arylsilanes under visible-light irradiation. This method relying in a radical chain mechanism shows a broad applicability and functional group tolerance, allowing for the effective reaction of simple arylsilanes, as well as complex structures and therapeutic derivatives.

A straightforward, visible-light triggered desilylation of arylsilanes by thiyl radicals is presented. Silyl groups are often used to block a reactive position in multi-step organic synthesis, for which a mild cleavage at a late-stage will provide new possibilities and disconnection routes by CAr-Si cleavage/deprotection. In this work, commercially available and cheap disulfides are employed for the first time in this type of C(sp2)-Si bond cleavage reactions. Thus, upon irradiation with visible-light, homolytic cleavage of the disulfide give rise to the corresponding thiyl radical that allows for a radical chain mechanism. This methodology represents a mild, fast and simple approach suitable for a broad variety of simply substituted arylsilanes. Moreover, the procedure could be easily extended to natural products and therapeutic derivatives, showing its robustness and synthetic application potential.

Introduction: Nurses’ attitudes and beliefs may impact pain management. This study investigated nurses’ perceptions regarding their own and patients’ pain experiences by examining relationships between pain cautiousness and stoicism, cultural sensitivity, and personal pain attitudes. Methodology: A correlational methodology examined nursing staff in a Midwestern private hospital. The sample included 102 primarily female (95.1%), Caucasian (97%), and married (66%) nursing staff. Measures included the Intercultural Sensitivity Scale, Pain Attitudes Questionnaire to Assess Stoicism and Cautiousness, and the Pain Management: Nurses’ Knowledge and Attitude Survey. Results: Cultural sensitivity was a significant predictor of pain knowledge and attitudes total score ( R2 = .081, β = .244, p = .040), while pain stoicism and pain cautiousness were not predictive. Discussion: Findings highlight the importance of nurses being aware of personal attitudes, beliefs, and cultural sensitivity in pain management. Results also demonstrate a gap between the knowledge and utilization of nonpharmacologic pain management interventions among nursing staff.

The first visible-light-mediated photocatalytic, metal- and base-free protodesilylation of arylsilanes is presented. The C(sp

Introduction: Here we report our results of a multi-center, open cohort study ("COVID-Kids-Bavaria") investigating the distribution of acute SARS-CoV-2 infections among children and staff in 99 daycare facilities and 48 elementary schools in Bavaria, Germany. Materials and Methods: Overall, 2,568 children (1,337 school children, 1,231 preschool children) and 1,288 adults (466 teachers, 822 daycare staff) consented to participate in the study and were randomly tested in three consecutive phases (September/October 2020, November/December 2020, March 2021). In total, 7,062 throat swabs were analyzed for SARS-CoV-2 by commercial RT-PCR kits. Results: In phase I, only one daycare worker tested positive. In phase II, SARS-CoV-2 was detected in three daycare workers, two preschool children, and seven school children. In phase III, no sample tested positive. This corresponds to a positive test rate of 0.05% in phase I, 0.4% in phase II and 0% in phase III. Correlation of a positive PCR test result with the local-7-day incidence values showed a strong association of a 7-day-incidence of more than 100/100,000 as compared to

Introduction Aligning expectations during the informed consent process before a child's surgery is an important element of good communication that benefits both surgical staff and families. We developed and evaluated a 2-hour pilot interprofessional workshop to improve the communication and relational skills of pediatric surgeons and nurse practitioners. Methods Focus groups with families identified key challenges in the process of informed consent. An interprofessional team, including parents whose children had experienced complex surgeries, developed the workshop collaboratively. A realistic simulation with professional actors portraying parents allowed surgical staff to practice communication skills and receive feedback about the parent perspective. Participants completed a postworkshop evaluation to determine whether the workshop met its objectives and whether they would change practice. Results Five key themes identified for the workshop included customize communication; align expectations; share clinical uncertainty; recognize/attend to emotions; and identify team members. Thirty-five clinicians participated in a workshop, and 89% completed evaluations. Three-quarters reported the learning to be valuable, and 64% were likely to change practice. Eighty-seven percent would recommend the workshop to other colleagues, and 58 to 74% felt more prepared to achieve each of eight specific skills. Discussion An innovative workshop for pediatric surgical practitioners to align family-clinician expectations can help improve clinician communication skills and comfort with informed consent. Keys to workshop development included involving parents to identify themes and participate as workshop co-faculty; enlisting leadership and recruiting surgical champions; and using pre-existing meetings to ease scheduling challenges of busy practitioners. Booster sessions may facilitate the desired cultural changes.

The potential of nitrogen (N) fertilizer forms to mitigate N 2 O emissions from agricultural fields is not very well understood. It is known that both reduced and oxidized N forms can be beneficial, depending on site-specific edaphic and climatic conditions. In the present study four laboratory incubation experiments were conducted under conditions that should minimize denitrification to investigate N 2 O emissions during the nitrification of solid N fertilizers. It was found that on two loamy sand soils with pH values slightly above pH 5, urea caused 2.7–3.8 fold higher cumulative N 2 O emissions than ammonium sulphate (AS). N 2 O emission rates from urea were accompanied by elevated soil nitrite levels, while those of AS were not. The direct addition of a NaNO 2 solution revealed an exponential relationship between soil nitrite levels and cumulative N 2 O emissions, indicating that soil nitrite induces N 2 O emissions, probably by nitrite reduction via nitrifier denitrification. When the soil pH was increased to 6.3 (soil from a long-term liming experiment) nitrite accumulation during nitrification was observed for both N forms. Cumulative N 2 O emissions did not differ between N forms on the latter soil, but N 2 O emission kinetics were faster for urea. Cumulative N 2 O emissions from AS at soil pH 6.3 were significantly higher than those of AS at pH values around 5. It was concluded that i) nitrite accumulation during nitrification of reduced N fertilizer forms can significantly contribute to N 2 O emissions under non-denitrifying conditions, ii) the risk of nitrite accumulation increases with higher soil pH values, and iii) that the alkalizing hydrolysis of urea increases the risk of nitrite accumulation and thus higher N 2 O emissions as well. This mechanism would explain why urea causes higher N 2 O emissions than fertilizers in the form of ammonium salts.

In this work we demonstrate the superiority of the IDDES turbulence model approach compared to the RANS formulation at the application of a Francis pump turbine flow simulation at part load conditions. At this operating point strongly swirling flow occurs in the draft tube, which leads to the vortex rope phenomenon, a rotating vortex around the stagnant region in the centre of the diffuser flow leading to a local low pressure zone. This hybrid RANS-LES turbulence model approach – based on the SST turbulence model – was implemented in OpenFOAM®-1.6-ext open source code and successfully validated for different test cases, like the decay of isotropic turbulence, periodic channel flow, flow over an abrupt expansion and a periodic hill flow. With these test cases constants were calibrated, a good prediction of boundary layer flow was proven and the ability to predict the flow correctly for numerically more difficult flow configurations. The flow in the pump turbine draft tube was analysed with laser measurements (LDA and PIV) and wall pressure sensors, as well as torque, hydraulic head and discharge measurements. All measurements serve as validation for the flow simulations. The results of the flow simulations with the IDDES turbulence model fit quite well with the measurements for the velocity components and especially for the second order statistics. This means that the turbulence is well resolved. The shape of the vortex rope is better predicted, leading to better conformity with the measurements, even for high frequencies. The hybrid turbulence model resolves the inertial range of turbulence.

Nitrogen fertilizers are supposed to be a major source of nitrous oxide (N2O) emissions from arable soils. The objective of this study was to compare the effect of N forms on N2O emissions from arable fields cropped with winter wheat (Triticum aestivum L.). In three field trials in North-West Germany (two trials in 2011/2012, one trial in 2012/2013), direct N2O emissions during a one-year measurement period, starting after application of either urea, ammonium sulfate (AS) or calcium ammonium nitrate (CAN), were compared at an application rate of 220 kg N ha−1. During the growth season (March to August) of winter wheat, N2O emission rates were significantly higher in all three field experiments and in all treatments receiving N fertilizer than from the non-fertilized treatments (control). At two of the three sites, cumulative N2O emissions from N fertilizer decreased in the order of urea > AS > CAN, with emissions ranging from 522–617 g N ha−1 (0.24–0.28% of applied fertilizer) for urea, 368–554 g N ha−1 (0.17–0.25%) for AS, and 242–264 g N ha−1 (0.11–0.12%) for CAN during March to August. These results suggest that mineral nitrogen forms can differ in N2O emissions during the growth period of winter wheat. Strong variations in the seasonal dynamics of N2O emissions between sites were observed which could partly be related to weather events (e.g., precipitation). Between harvest and the following spring (post-harvest period) no significant differences in N2O emissions between fertilized and non-fertilized treatments were detected on two of three fields. Only on one site post-harvest emissions from the AS treatment were significantly higher than all other fertilizer forms as well as compared to the control treatment. The cumulative one-year emissions varied depending on fertilizer form across the three field sites from 0.05% to 0.51% with one exception at one field site (AS: 0.94%). The calculated overall fertilizer induced emission averaged for the three fields was 0.38% which was only about 1/3 of the IPCC default value of 1.0%.

Nitrogen fertilizers are a major source of nitrous oxide (N2O) emissions from arable soils. The relationship between nitrogen application rates and N2O emissions was evaluated during the growth period of winter wheat (~140 days) at six field sites in north-western Germany. Nitrogen was applied as calcium–ammonium–nitrate, with application rates ranging between 0 and 400 kg N ha−1. One trial was conducted in 2010, three trials in 2011 and two trials in 2012. Additionally, post-harvest N2O emissions were evaluated at two field sites during autumn and winter (2012–2013). The emission factors (during the growth period) varied between 0.10 and 0.37 %. Annual N2O emissions ranged between 0.46 and 0.53 % and were consistently lower across all sites and years than to the IPCC Tier 1 default value (1.0 %). Across all sites and years, the relationship between N2O and N application rate was best described by linear regression even if nitrogen amounts applied were higher than the nitrogen uptake of the crop. Additionally, annual N2O emissions per unit of harvested wheat grain were calculated for two field sites to assess the environmental impact of wheat grain production. Yield-scaled N2O emissions followed a hyperbolic function with a minimum of 177 and 191 g N2O–N t grain yield−1 at application rates of 127 and 150 kg N ha−1, followed by an increase at higher N application rates. This relationship indicates that wheat crop fertilization does not necessarily harm the environment through N2O emissions compared to zero fertilization. Thus, improving nitrogen use efficiency may be the best management practice for mitigating yield-scaled N2O emissions.

The leaching of nitrate is an important way of N losses from agricultural soils in humid regions. Nitrate leaching is difficult to control as most soils under crop production do not have anion-exchange properties, and nitrate remains mobile in the solution. The present work evaluated the potential use of a synthetic layered double-hydroxide (LDH) mineral as a nitrate exchanger in soil. The LDH used was a chloride form of a magnesium-aluminum layered double hydroxide with the formula: [Mg2+0.82Al3+0.18(OH)2]0.18+[(Cl–)0.18 0.5(H2O)]0.18–. Experiments were carried out in aqueous solutions as well as in soil with the following objectives: (1) to characterize the nitrate adsorption capacity on the LDH, (2) to study its selectivity for nitrate adsorption in solution, (3) to evaluate the reversibility for nitrate exchange, and (4) to study the nitrate adsorption capacity and nitrate diffusion towards the LDH in soil.

The potential use of a layered double hydroxide (LDH) to act as a nitrate buffer system in soil in order to reduce the movement of nitrate was investigated. Long-term plant and soil experiments were carried out under greenhouse conditions with the following objectives: (i) evaluate the nitrate adsorption capacity of the LDH during crop growth, and its influence on N uptake, (ii) study the ability of the LDH to adsorb nitrate mineralized during fallow periods, and its influence on nitrate leaching, (iii) evaluate the reversibility for nitrate exchange of the LDH under cultivation conditions, and (iv) determine the nitrate buffer capacity of the soil after LDH application. The LDH adsorbed nitrate from the soil solution during the growth period without affecting plant N uptake. As a result of the adsorption of nitrate on the LDH, the nitrate-N concentration in the soil solution at harvest was reduced by a factor of ten compared to a soil without LDH. The LDH efficiently adsorbed nitrate that was mineralized in the soil during periods without cultivation, reduced nitrate-N leaching losses by about 80%, and kept this nitrate available for a following crop. The nitrate buffer capacity of the soil after 15months increased from 0.3 (without LDH) to 2.7 with the application of 10g LDH kg−1 soil. It is concluded that the LDH has a potential to be used as a long-term nitrate exchanger to control the movement of nitrate in soil, and thereby reduce risks of nitrate leaching in crop production in sensible areas.

Clearance determination by compartmental analysis of hippurate renograms was compared in 30 cases to the conventional PAH and to the partly shielded whole body counting technique. Good correlations between compartmental analysis and PAH method (r = 0.96) as well as the whole body technique (r = 0.94) were found. Correlation between PAH and whole body method was not always satisfactory (r = 0.85). In an additional study influence of greater count rates become obvious: correlation coefficients increase from 0.89 (131I-hippurate, n = 97) to 0.95 (123I-hippurate, n = 38). Determination of the divided clearance correlates well (r = 0.95). Using 123I-hippurate all the information available by radioisotopic kidney investigations can be obtained in a one-step procedure.

A new life cycle assessment (LCA) method is presented, which is specifically tailored to plant nutrition in arable crop production. Generally, LCA is a methodology to assess all environmental impacts associated with a product or a process by accounting and evaluating its resource consumption and emissions. In LCA studies the entire production system should be considered, i.e. for crop production systems the analysis includes not only the on-field activities, but also all impacts related to the production of raw materials (minerals, fossil fuels) and farm inputs like fertilizers, plant protection substances, machinery or seeds. The LCA method developed in this study evaluates the impact of emissions and resource consumption associated with crop production on the following environmental effects: depletion of abiotic resources, land use, climate change, toxicity, acidification, and eutrophication. In order to enable conclusions on the overall environmental impact of alternative crop nutrition systems, an aggregation procedure to calculate indicators for resource depletion (RDI) and environmental impacts (EcoX) has been developed. The higher the EcoX value, the higher is the overall environmental burden associated with the product under investigation. An environmental analysis of arable crop production systems based on this LCA method is especially appropriate in order to: (1) detect environmental hot spots in the system; (2) trace back environmental impacts of arable farming products to their sources and on that basis to suggest options for improvement; and (3) contribute to the debate on the environmental preference of alternative cropping systems in an informed way.

This study examined the environmental impact of different nitrogen (N) fertilizer rates in winter wheat production by using a new life cycle assessment (LCA) method, which was specifically tailored to crop production. The wheat production system studied was designed according to “good agricultural practice”. Information on crop yield response to different N rates was taken from a long-term field trial in the UK (Broadbalk Experiment, Rothamsted). The analysis considered the entire system, which was required to produce 1 ton of wheat grain. It included the extraction of raw materials (e.g. fossil fuels, minerals), the production and transportation of farming inputs (e.g. fertilizers) and all agricultural operations in the field (e.g. tillage, harvest). In a first step, all emissions and the consumption of resources connected to the different processes were listed in a Life Cycle Inventory (LCI) and related to a common unit, which is 1 ton of grain. Next a Life Cycle Impact Assessment (LCIA) was done, in which the inventory data are aggregated into indicators for environmental effects, which included resource depletion, land use, climate change, toxicity, acidification, and eutrophication. After normalization and weighting of the indicator values it was possible to calculate summarizing indicators for resource depletion and environmental impacts (EcoX). At N rates of 48, 96, 144 or 192 kg N/ha the environmental indicator “EcoX” showed similar values per ton of grain (0.16–0.22 EcoX/ton of grain). At N rates of zero, 240 and 288 kg N/ha the EcoX values were 100–232% higher compared with the lowest figure at an N rate of 96 kg N/ha. At very low N rates, ‘land use’ was the key- environmental-factor, whereas at high N rates ‘eutrophication’ was the major problem. The results revealed that agronomical optimal arable farming does not necessarily come into conflict with economic and environmental boundary conditions.

The study was carried out to quantitate the transfer of toxaphene and chlordane compounds from commercial fish feed into the edible part of rainbow trout, Oncorhynchus mykiss (Walbaum) under normal rearing conditions. Trout were fed with unspiked high energy feed for salmon (fat content 26–30%) over a period of 19 months. The average weight of trout increased from 10 g to more than 2092 g, reaching sizes of 51 cm length. Considerable amounts of toxaphene and chlordane residues were transferred from fish feed into trout muscle. Toxaphene concentrations increased up to 8.6 µg (Σ toxaphene indicator compounds 1–3) kg−1 wet weight (w.w.) and chlordane reached 5.3 µg Σoxy-, trans-, cis-chlordane + t-nonachlor kg−1 w.w. Results are also discussed on the contaminant levels based on the fat content and the effect of sexual maturation is considered in this study. The data allow the establishment of transfer rates for toxaphene and chlordane congeners from high energy diet into the edible part of farmed rainbow trout.

The impact assessment of the consumption of abiotic resources, such as fossil fuels or minerals, is usually part of the Life Cycle Impact Assessment (LCIA) in LCA studies. The problem with the consumption of such resources is their decreasing availability for future generations. In currently available LCA methods (e.g. Eco-indicator’ 99/Goedkoop and Spriensma 1999, CML/Guinee 2001), the consumption of various abiotic resources is aggregated into one summarizing indicator within the characterization phase of the LCIA. This neglects that many resources are used for different purposes and are not equivalent to each other. Therefore, the depletion of reserves of functionally non-equivalent resources should be treated as separate environmental problems, i.e. as separate impact sub-categories. Consequently, this study proposes assigning the consumption of abiotic resources to separate impact sub-categories and, if possible, integrating them into indicators only according to their primary function (e.g. coal, natural gas, oil → consumption of fossil fuels; phosphate rock → consumption of phosphate). Since this approach has been developed in the context of LCA studies on agricultural production systems, the impact assessment of the consumption of fossil fuels, phosphate rock, potash salt and lime is of particular interest and serves as an example. Following the general LCA framework (Consoli et al. 1993, ISO 1998), a normalization step is proposed separately for each of the subcategories. Finally, specific weighting factors have been calculated for the sub-categories based on the ’distance-to-target’ principle. The weighting step allows for further interpretation and enables the aggregation of the consumption of different abiotic resources to one summarizing indicator, called the Resource Depletion Index (RDI). The proposed method has been applied to a wheat production system in order to illustrate the conceptual considerations and to compare the approach to an established impact assessment method for abiotic resources (CML method, Guinee 2001).

Recovery of fertilizer nitrogen (N) applied to winter wheat crops at tillering in spring is lower than that of N applied at later growth stages because of higher losses and immobilization of N. Two strategies to reduce early N losses and N immobilization and to increase N availability for winter wheat, which should result in an improved N use efficiency (= higher N uptake and/or increased yield per unit fertilizer N), were evaluated. First, 16 winter wheat trials (eight sites in each of 1996 and 1997) were conducted to investigate the effects of reduced and increased N application rates at tillering and stem elongation, respectively, on yield and N uptake of grain. In treatment 90-70-60 (90 kg N ha−1 at tillering, 70 kg N ha−1 at stem elongation and 60 kg N ha−1 at ear emergence), the average values for grain yield and grain N removal were up to 3.1 and 5.0 % higher than in treatment 120-40-60, reflecting conventional fertilizer practice. Higher grain N removal for the treatment with reduced N rates at tillering, 90-70-60, was attributed to lower N immobilization (and N losses), which increased fertilizer N availability. Secondly, as microorganisms prefer NH4+ to NO3− for N immobilization, higher net N immobilization would be expected after application of the ammonium-N form. In a pot experiment, net N immobilization was higher and dry matter yields and crop N contents at harvest were lower with ammonium (ammonium sulphate + nitrification inhibitor Dicyandiamide) than with nitrate (calcium nitrate) nutrition. Five field trials were then conducted to compare calcium nitrate (CN) and calcium ammonium nitrate (CAN) nutrition at tillering, followed by two CAN applications for both treatments. At harvest, crop N and grain yield were higher in the CN than in the CAN treatment at each N supply level. In conclusion, fertilizer N use efficiency in winter wheat can be improved if N availability to the crops is increased as a result of reduced N immobilization (and N losses) early in the growth period. N application systems could be modified towards strategies with lower N applications at tillering compensated by higher N dressing applications later. An additional advantage is expected to result from use of nitrate-N fertilizers at tillering. Strategien zur Verbesserung der Effizienz von Dungerstickstoff in Winterweizen Aus fruheren Versuchen mit Winterweizen ist bekannt, das zur Ernte die Wiederfindung von im Fruhjahr zur Bestokkung gedungtem Stickstoff (N) geringer ist, als die von N aus Spatgaben. Die Ursachen liegen in einer hoheren mikrobiell-bedingten Netto-N-Immobilisation, aber auch N-Verlusten zwischen Bestockung und Schosbeginn im Vergleich zu spateren Wachstumstadien begrundet. In den vorliegenden Versuchen wurden zwei Strategien getestet, um insbesondere die fruh in der Vegetation auftretende Netto-N-Immobilisation zu vermindern. Die dadurch erwartete erhohte N-Verfugbarkeit sollte zu einer erhohten N-Effizienz (hoherer N-Entzug/Ertrag bezogen auf die N-Dungung) fuhren. 1996 und 1997 wurden jeweils 8 Feldversuche mit Winterweizen durchgefuhrt, um den Einflus einer reduzierten Andungung bei gleichzeitig erhohter Schossergabe im Vergleich zur konventionellen N-Dungung zu untersuchen. Tatsachlich wurden in dem Prufglied 90-70-60 (N-Sollwertdungung: 90 kg N ha−1, Schossergabe: 70 kg N ha−1, Ahrengabe: 60 kg N ha−1) im Mittel bis zu 3.1 % hohere Ertrage und 5.0 % hohere N-Abfuhren mit dem Korn im Vergleich zur konventionellen Variante 120-40-60 (N-Sollwertdungung: 120 kg N ha−1, Schossergabe: 40 kg N ha−1 und Ahrengabe: 60 kg N ha−1) erzielt. Die hohere N-Abfuhr kann auf eine erhohte N-Verfugbarkeit infolge geringerer mikrobieller N-Festlegung zuruckgefuhrt werden. Da die vornehmlich heterotrophen Bodenmikroorganismen bevorzugt NH4+ gegenuber NO3− immobilisieren, kann eine hohere N-Immobilisation bei Ammonium-Dungung erwartet werden. Tatsachlich wurden in einem Gefasversuch nach Dungung von Ammoniumsulfat (+ Nitrifikationshemmer Dicyandiamid) geringere Trokkenmasseertrage und N-Aufnahmen von Weizenpflanzen erzielt als mit Calciumnitrat. Fur die Ammoniumsulfatvariante ergab sich eine hohere Netto-N-Immobilisation. Danach wurde in funf Feldversuchen mit Winterweizen der Einflus einer Andungung mit Nitrat (Calciumnitrat) im Vergleich zur Verwendung des ammoniumhaltigen Kalkammonsalpeters (KAS) auf die N-Aufnahme und den Kornertrag untersucht (beide Varianten erhielten KAS als Spatgaben). In der nitratangedungten Variante wurden zum Teil signifikant hohere Ertage und N-Aufnahmen in Korn und Stroh ermittelt. Aus den dargestellten Versuchen kann gefolgert werden, das die Dungerstickstoff-Effizienz verbessert werden kann, wenn vor allem die N-Immobilisation (und eventuell auch N-Verluste) in fruhen Wachstumsstadien zwischen Bestockung und Schosbeginn verringert und so die N-Verfugbarkeit erhoht wird. Es kann empfohlen werden Winterweizenbestande mit geringeren N-Mengen – als nach N-Sollwert 120 kg N ha−1 vorgesehen – anzudungen und die Schossergabe entsprechend zu erhohen. Die Verwendung von nitrathaltigen Dungern bei der Andungung ist von Vorteil.

The suitability of the Life Cycle Assessment (LCA) methodology to analyse the environmental impact of agricultural production is investigated. The first part of an LCA is an inventory of all the resources used and emissions released due to the system under investigation. In the following step, i.e. the Life Cycle Impact Assessment the inventory data were analysed and aggregated in order to finally get one index representing the total environmental burden. For the Life Cycle Impact Assessment (LCIA) the Eco-indicator 95 method has been chosen, because this is a well-documented and regularly applied impact assessment method. The resulting index is called Eco-indicator value. The higher the Eco-indicator value the stronger is the total environmental impact of an analysed system. A sugar beet field experiment conducted in northeastern Germany was chosen as an example for the analysis. In this experiment three different nitrogen fertilisers (calcium ammonium nitrate=CAN, urea ammonium nitrate solution=UAN, urea) were used at optimum N rates. The obtained Eco-indicator values were clearly different for the N fertilisers used in the sugar beet trial. The highest value was observed for the system where urea was used as N source. The lowest Eco-indicator value has been calculated for the CAN system. The differences are mainly due to different ammonia volatilisation after application of the N fertilisers. For all the systems the environmental effects of acidification and eutrophication contributed most to the total Eco-indicator value. The results show that the LCA methodology is basically suitable to assess the environmental impact associated with agricultural production. A comparative analysis of the system, contribution to global warming, acidification, eutrophication and summer smog is possible. However, some important environmental issues are missing in the Eco-indicator 95 method (e.g. the use of resources and land).

Pot and field experiments were conducted to determine microbial immobilization of N fertilizer during growth periods of winter wheat and winter barley. In a pot experiment with winter wheat, Ca(15NO3)2 was applied at tillering [Zadok's growth stage (GS) 25)], stem elongation (GS 31) and ear emergence (GS 49). Rates of 100 mg N pot–1, 200 mg N pot–1 or 300 mg N pot–1 were applied at each N application date. At crop maturity, 15N-labelled fertilizer N immobilization was highest at the highest N rate (3×300 mg N pot–1). For each N-rate treatment about 50% of the total immobilized fertilizer N was immobilized from the first N dressing, and 30% and 20% of the total 15N immobilized was derived from the second and third applications, respectively. In field trials with winter wheat (three sites) and winter barley (one site) N was applied at the same growth stages as for the pot trial. N was also applied to fallow plots, but only at GS 25. N which was not recovered (neither in crops nor in soil mineral N pools) was considered to represent net immobilized N. A clear effect of N rate (51–255 kg N ha–1) on net N immobilization was not found. The highest net N immobilization was found for the period between GS 25 (March) and GS 31 (late April) which amounted to 54–97% of the total net N immobilized at harvest (July/August). At GS 31, non-recovered N was found to be of similar magnitude for cropped and fallow plots, indicating that C from roots did not affect net N immobilization. Microbial biomass N (Nmic) was determined for cropped plots at GS 31. Although Nmic tended to be higher in fertilized than in unfertilized plots, fertilizer-induced increases in Nmic and net N immobilization were poorly correlated. It can be concluded that microbial immobilization of fertilizer N is particularly high after the first N application when crop growth and N uptake are low.

The effect of increasing rates of 15N-labelled Ca(NO3)2 (N0 = no N application, N300 = 300 mg N/pot; N600 = 600 mg N/pot; N900 = 900 mg N/pot) on recovery of fertilizer N in winter wheat plants and soil (total soil N, soil microbial biomass N [Nmic], extractable organic N [Norg]) and on N mineralization (NMsoil) was investigated at milk-ripe growth stage in a pot experiment. The N rates were equally split at tillering, stem elongation and ear emergence. Fertilizer N recovered in crops increased with increasing N rates (N300: 223.5 mg N/pot [74.5% of applied fertilizer N], N600: 445.6 mg N/pot [74.3%], N900: 722.1 mg N/pot [80.2%]). NMsoil slightly increased from N0 (43.8 mg N/pot) to N900 (75.6 mg N/pot) indicating that N application enhanced availability of soil-derived N for the plants. However, in fertilized treatments NMsoil is balanced by immobilization and losses (non-recovered fertilizer N). Therefore the effective soil N mineralization is indicated by apparent net N mineralization (ANNM = NMsoil — fertilizer N immobilization — lost fertilizer N). Fertilizer N immobilization in soil increased from N300 (38.7 mg N/pot) to N600 (60.7 mg N/pot) and N900 (65.5 mg N/pot). Lost fertilizer N increased from N300 (14.8 mg N/pot) to N600 (56.7 mg N/pot) and N900 (62.1 mg N/pot). As a consequence negative ANNM values were calculated at N600 and N900. Due to the small differences between N600 and N900 fertilizer N immobilization and lost fertilizer N did not increase linearly with increasing N rates, i.e. both processes were limited by factors other than N rate. Only 5.6—7.4% of the immobilized fertilizer N was recovered in Norg and 5.4—9.3% in Nmic soil pools. It is assumed that most of the immobilized fertilizer N was in non-extractable organic N forms. Nmic and Norg were weak indicators for the extent of fertilizer N immobilization. Einfluss steigender 15N-Dungermengen auf die Wiederfindung von Dungerstickstoff in Winterweizenpflanzen und N-Fraktionen des Bodens im Gefasversuch In einem Gefasversuch wurde der Einfluss steigender Mengen von 15N-markiertem Ca(NO3)2 (N0 = ungedungt, N300 = 300 mg N/Gefas, N600 = 600 mg N/Gefas, N900 = 900 mg N/Gefas) auf die Wiederfindung dieses 15N-markierten Dungerstickstoffs in Winterweizenpflanzen und N-Fraktionen des Bodens (gesamter N im Boden, mikrobieller Biomasse N [Nmic], extrahierbarer organischer N [Norg]) sowie auf die N-Mineralisation aus dem Bodenvorrat (NMsoil) untersucht. Die Dungung wurde zu gleichen Teilen zur Bestockung, zum Schossen und zum Ahrenschieben appliziert. Der Versuch wurde zur Milchreife geerntet. Die Wiederfindung des Dungerstickstoffs nahm mit steigender N-Dungung zu (N300: 223,5 mg N/Gefas [74,5% des Dunger-N], N600: 445,6 mg N/Gefas [74,3%], N900: 722,1 mg N/Gefas [80,2%]). Auch NMsoil nahm durch die N-Dungung zu (75,6 mg N/Gefas fur N900 gegenuber 43,8 mg N/Gefas fur N0). In gedungten Prufgliedern wird NMsoil durch Immobilisation und Verluste von Dunger-N ausgeglichen. Die den Pflanzen effektiv zur Verfugung stehende N-Mineralisation wird daher durch die apparente Netto-N-Mineralisation (ANNM = NMsoil — Dunger-N-Immobilisation — Dunger-N-Verluste) beschrieben. Fur N600 und N900 wurden negative ANNM-Werte errechnet. Die Dunger-N-Immobilisation nahm zwischen N300 (38,7 mg N/Gefas) uber N600 (60,7 mg N/Gefas) bis N900 (65,5 mg N/Gefas) zu und die Dunger-N-Verluste stiegen von N300 (14,8 mg N/Gefas) uber N600 (56,7 mg N/Gefas) bis N900 (62,1 mg N/Gefas). Die geringen Unterschiede zwischen N600 und N900 zeigen an, dass weder die Immobilisation noch Verluste von Dunger-N stetig linear mit steigender N-Dungung zunahmen und andere Faktoren als die N-Dungermenge limitierend waren. Nur 5,6—7,4% des immobilisierten Dunger-N konnten als Norg und 5,4—9,3% im Nmic gefunden werden. Der Rest des immobilisierten Dunger-N lag in nicht-extrahierbaren organischen N-Fraktionen vor. Nur anhand von Nmic oder Norg konnte daher nicht auf die Hohe der Dunger-N-Immobilisation geschlossen werden.

Field trials were conducted over two years to investigate the effect of increasing N supply on apparent fertilizer N recovery by winter cereal crops (4 × wheat and 2 × barley) and on non-recovered N. Apparent fertilizer N recovery was calculated by comparing N in fertilized and unfertilized crops. Non-recovered N is defined as N which was neither found in crops nor soil mineral N (N min = NH 4 -N + NO 3 -N). At N supply levels according to common farming practice (N cfp = 190 to 220 kg N/ha), 60- 93% of the fertilizer N was recovered in crops at harvest, while at high N supply levels of 265 to 273 kg N/ha 58-76% of fertilizer N was recovered. There were small differences in soil N min in 0-200 cm between N cfp and unfertilized plots, but substantial increases in N min occurred at the highest N supply. Amounts of non-recovered N differed substantially between sites (maximum value of 84 kg N/ ha). Non-recovered N increased with increasing N rate on only 3 out of the 6 sites, indicating that N immobilization was not necessarily dependent on N rate. The fate of non-recovered N was studied for a further year by growing catch crops on the sites after cereal harvest. N re-mineralization deduced from changes in catch crop N and in N min indicated that non-recovered N had been immobilized in the soil. At three sites, crop N uptake was found between milk-ripe stage and harvest (19 to 60 kg N/ha) suggesting substantial uptake of N mineralized from soil. However, grain yields were lower with N rates below N cfp , indicating that late net soil N mineralization could not compensate for reductions in N fertilizer rate in these trials.

Wave filters and absorbers are important coastal structures. Their efficiency depends on wave reflection and transmission as well as on energy dissipation. Because of their nonlinear characteristics, wave filters and absorbers must be analyzed and optimized experimentally. In a more general approach, two universally valid coefficients are determined for each individual filter element. Based on these data, arbitrary, multi-layer wave absorbers can be evaluated. Filter hydrodynamics mainly depend on porosity and wave kinematics, i.e., the profiles of horizontal velocity and acceleration. With reference to an initial wave, the related near-field velocity and acceleration at the filter element are expressed as functions of a drag and an inertia term. The corresponding coefficients, which are universally applicable, in connection with the relevant horizontal velocity and acceleration at the filter area are used to calculate the reflection, transmission, energy dissipation, and wave forces on arbitrary filter or absorber components, elements, and systems. The numerical analysis is validated by an experimental program in regular and irregular seas, and transient wave trains. Transient wave trains are efficiently used for: 1) Separate measurements of the initial wave group, as well as its reflection and transmission. Due to the short duration, the incoming wave train is easily separated from the reflected and the transmitted wave. This allows an accurate analysis of the associated flow fields and energies. For a variety of wave filters, the paper presents the evaluation of the foregoing characteristic coefficients, based on experiments with representative transient wave groups. 2) Model tests in extreme wave conditions (freak waves). Tests with breaking transient wave packets prove that the obtained maximum wave force on a structure is much higher than the long-term model test results in irregular waves, for a given spectrum.

Apparent net N mineralization (mineralization minus immobilization) in fertilized and unfertilized treatments was determined in 133 fertilizer trials with cereals and sugar beet over 3 years (1988-90). Apparent net mineralization was defined as follows: Apparent net N mineralization = (crop N at harvest - crop N in spring) - (Nmin in spring - Nmin at harvest) - N fertilizer applied. Results can be summarised as follows: 1 For both crop species, apparent net N mineralization decreased in the following order: unfertilized > optimally fertilized > overfertilized. 2 The decrease in apparent net mineralization of N with increasing rate of N fertilizer was attributed to immobilization. This was confirmed by measurements of increased remineralization during the following autumn, winter and during the growing season in the following year. 3 Both the soil Nmin at harvest and fertilizer N which was immobilized and remineralized during autumn and winter, is at risk of being leached. At optimal fertilizer doses 30 kg N/ha and 74 kg N/ha were leached on average over winter from loamy and sandy soils respectively. 4 Apparent net mineralization was not important for optimally fertilized cereals and therefore does not need to be considered for fertilizer recommendations for winter cereals. This does not apply to land receiving slurry applications before or during the growth period. 5 In contrast to cereals, apparent net mineralization contributed considerably to the nutrition of sugar beet. Approximately 140 kg N/ha were mineralized at the optimum rate of N fertilizer application. However, the EUF- and CaCl2-methods were unable to predict N mineralization and were therefore unable to improve the prediction of fertilizer requirement even in combination with the NO3 soil N fraction. Auswirkungen der N-Dungerhohe auf die apparente N-Nettomineralisation wahrend und nach der Vegetationszeit von Getreide und Zuckerruben In 133 Dungungsversuchen zu Getreide und Zuckerruben wurde die apparente N-Nettomineralisation (Mineralisation minus Immobilisation) in gedungten und ungedungten Varianten ermittelt. Sie entspricht der Differenz zwischen der N-Aufnahme der Pflanzen (Fruhjahr bis Ernte) und dem Nmin-Angebot plus Dungung (Nmin im Fruhjahr minus Nmin zur Ernte plus N-Dungung). Folgende Ergebnisse wurden erzielt: 1 Bei allen Kulturarten verringerte sich die N-Nettonachlieferung in der nachstehenden Reihenfolge: ungedungt > optimal gedungt > uber-dungt. 2 Die bei steigendem N-Angebot abnehmende Nettomineralisation ist vor allem auf eine zunehmende N-Immobilisation zuruckzufuhren. Dies ergab sich aus der erhohten Remineralisation, die sowohl uber Herbst und Winter als auch in der nachsten Vegetationsperiode bei steigendem N-Angebot zur Vorkultur gemessen wurde. 3 Der zur Ernte vorhandene Nmin-Rest und auch der kurzfristig immobilisierte und uber Herbst und Winter remineralisierte Stickstoff kann auf Boden mit geringer Wasserkapazitat ausgewaschen werden. Wahrend auf Lehmstandorten bei optimaler N-Dungung 30 kg N/ha ausgewaschen wurden, betrug der mittlere N-Austrag auf Sandboden 74 kg N/ha. 4 Die Nettomineralisation war bei Getreide mit optimaler Dungungshohe unbedeutend. Eine Bestimmung und Berucksichtigung der N-Nachlieferung fur die Bemessung der N-Dungung bei Wintergetreide ist daher in vielen Fallen nicht erforderlich. Dies gilt fur Flachen auf denen keine Gulleapplikation kurz vor oder wahrend der Vegetationsperiode erfolgte. 5 Im Gegensatz zu Getreide tragt bei Zuckerruben die Nettomineralisation masgeblich zur Ernahrung des Bestandes bei. Bei optimaler N-Dungung wurden zusatzlich ca. 140 kg N/ha mineralisiert. Allerdings konnten Methoden zur Bestimmung der N-Nachlieferung (EUF-, CaCl2-Norg) die bodenburtige N-Freisetzung nicht vorhersagen und verbesserten auch in Kombination mit der NO3-N-Fraktion des Bodens die Dungerbedarfsermittlung nicht.

A method is described which allowed the quantification of the potential uptake of P and Mg from the subsoil (>30cm) by spring wheat. Wheat was grown on an artificial topsoil (sand with no plant available P or Mg) which was superimposed on loess subsoils in N. Germany. The supply of P and Mg in the topsoil was varied by application of different quantities of P and Mg fertilizer. Uptake of P and Mg from the subsoil was calculated as the difference between total plant uptake (determined by plant analysis) and the quantities of P and Mg removed from the topsoil (determined by soil analysis). P uptake from the subsoil increased from 37% to 85% of total P uptake, with decreasing P supply in the topsoil. Calculations of potential supply by diffusion showed that, with a CAL-extractable P2O5 content in the subsoil of 9 mg 100g-1, supply from the subsoil was only possible if the influence of root hairs was considered. The method also showed that the total demand for Mg by spring wheat could be satisfield from the supply of Mg from the subsoil of typical loess soils. Mg uptake from the subsoil decreased to 33% of total uptake with increasing Mg supply in the topsoil.

Background The functional outcome after stroke is improved by more intensive or sustained therapy. When the affected hand has no functional movement, therapy is mainly passive movements. A novel device for repeating controlled passive movements of paralysed fingers has been developed, which will allow therapists to concentrate on more complicated tasks. A powered cam shaft moves the four fingers in a physiological range of movement. Methods After refining the training protocol in 2 chronic patients, 8 sub-acute stroke patients were randomised to receive additional therapy with the Finger Trainer for 20 min every work day for four weeks, or the same duration of bimanual group therapy, in addition to their usual rehabilitation. Results In the chronic patients, there was a sustained reduction in finger and wrist spasticity, but there was no improvement in active movements. In the subacute patients, mean distal Fugl-Meyer score (0–30) increased in the control group from 1.25 to 2.75 (ns) and 0.75 to 6.75 in the treatment group (p < .05). Median Modified Ashworth score increased 0/5 to 2/5 in the control group, but not in the treatment group, 0 to 0. Only one patient, in the treatment group, regained function of the affected hand. No side effects occurred. Conclusion Treatment with the Finger Trainer was well tolerated in sub-acute & chronic stroke patients, whose abnormal muscle tone improved. In sub-acute stroke patients, the Finger Trainer group showed small improvements in active movement and avoided the increase in tone seen in the control group. This series was too small to demonstrate any effect on functional outcome however.

A K/Rb isotope dilution method was used to determine the uptake of K from undisturbed subsoils. Rb was applied to the topsoil (0–30 cm) to trace the K taken up from the topsoil by crops. The K/Rb ratio in the crops increases when roots contact the Rb-free subsoil. This change in the K/Rb ratio enables the calculation of the uptake of K from the subsoil. Results of 34 field experiments on loess-parabrown soils in N. Germany showed that the subsoil (>30 cm) supplied, on average, 34% of the total K uptake by spring wheat (range 9–70%). The range between the experimental sites is considered in relation to the contents of K in the top and subsoils (as extracted by 0.025 N CaCl2 solution), the proportion of the total root length in the subsoils, and competition for K between roots in the top and subsoil. In subsoils with similar K contents, uptake from the subsoil decreased significantly from 65 to 21% of total K uptake, as K contents in the topsoils increased from 4 to 8 mg K/100 g. On sites with the same K contents in topsoils (9 mg K/100 g), the subsoil supplied 12 to 61% of total K uptake as the K contents of the subsoil increased from 2 to 27 mg K/100 g. The contribution of uptake of K from the subsoil increased with the development of the crop, from 8% at first node stage to 35% at ear emergence, as the proportion of total root length in the subsoil increased. High root length densities in the topsoil (9 cm/cm3) resulted in competition for K between roots and increased uptake of K from the subsoil.

SummaryPatients received 2,000 ml of dialysate intraperitoneally with five exchanges per day during continuous peritoneal dialysis (CAPD) for the treatment of terminal renal insufficiency. During a dwell time of 4 h the dialysate reached a total protein concentration up to 100 mg/dl by mass transfer of intravascular proteins. The composition is dependent on the molecular weight of the proteins. This results in an intraperitoneal hemostatic system of low concentration and different composition.We found an intraperitoneal fibrinogen cleavage and thrombin- antithrombin Ill-complex formation leading to increased levels of fibrinopeptide A (FPA: 33.3 ± 7.0 ng/ml) and thrombin-antithrombin Ill-complex (TAT: 4.7 ± 0.4 ng/ml) in plasma by mass transfer from dialysate to plasma. t-PA (tissue plasminogen activator) and PAI-1 (plasminogen activator inhibitor type 1) concentrations in plasma were within the normal range. The dialysate concentrations indicated a low local secretion. The fibrinolytic fibrin fragment D-dimer and the fibrinogen degradation product concentrations in plasma were greater than in dialysate. But the relations of the proteins between plasma and dialysate refer to a local intraperitoneal production as well.The results show that intraperitoneal coagulation predominates over fibrinolysis which is accompanied by an intravascular fibrinolysis in patients undergoing CAPD. Neoantigens produced in dialysate and diffused to plasma are comparable to changes seen in disseminated intravascular coagulation.

Cyanide-Catalyzed Conjugate Addition of Aryl Aldehydes: 4-OXO-4-(3-PYRIDYL)BUTYRONITRILE reactant: 107.1 g. (1.001 mole) of 3-pyridinecarboxaldehyde product: 4-oxo-4-(3-pyridyl)butyronitrile product: R1 = C6H5, R2 = R3 = H product: R1 = C6H5, R2 = H, R3 = CH3 product: R1 = C6H5, R2 = CH3, R3 = H product: R1 = R2 = C6H5, R3 = H product: R1 = 4-ClC6H4, R2 = R3 = H Keywords: addition, to CC; N,N-dimethylformamide; 3-pyridinecarboxaldehyde, purification of; sodium cyanide, poison

Acyloin condensation by thiazolium ion catalysis: butyroin catalyst: 13.4 g (0.05 mol) of 3-benzyl-5-(2-hydroxyethyl)-4-methyl-1,3-thiazolium chloride product: butyroin product: furoin Keywords: addition, to CO; acetonitrile; 3-benzyl-5-(2-hydroxyethyl)-4-methyl-1,3-thiazolium chloride

The Stetter reaction: 2,5-undecanedione and 3-methyl-2-pentyl-2-cyclopenten-1-one (dihydrojasmone) product: 3-Methyl-2-pentyl-2-cyclopenten-1-one (Dihydrojasmone). product: 2,5-Undecanedione (92.1 g, 0.5 mol) Keywords: acylation; addition, to CC; addition, to CO; addition, to CO; annulation, carbocyclic-[5]; cyclization, condensation; enamine or imine formation; halogenation, bromination; rearrangements; chromic acid on silica gel, preparation; triethylamine; benzene; nitrosyl chloride; sodium ethoxide

The impact category ‘land use’ describes in the Life Cycle Assessment (LCA) methodology the environmental impacts of occupying, reshaping and managing land for human purposes. Land use can either be the long-term use of land (e.g. for arable farming) or changing the type of land use (e.g. from natural to urban area). The impact category ‘land use’ comprises those environmental consequences, which impact the environment due to the land use itself, for instance through the reduction of landscape elements, the planting of monocultures or artificial vegetation, or the sealing of surfaces. Important environmental consequences of land use are the decreasing availability of habitats and the decreasing diversity of wildlife species. The assessment of the environmental impacts of land use within LCA studies is the objective of this paper. Land use leads to a degradation of the naturalness of the area utilised. In this respect the naturalness of any area can be defined as the sum of land actually not influenced by humans and the remaining naturalness of land under use. To determine the remaining naturalness of land under use, this study suggests applying the Hemeroby concept. “Hemeroby is a measure for the human influence on ecosystems” (Kowarik 1999). The Hemeroby level of an area describes the intensity of land use and can therefore be used to characterise different types of land use. Characterization factors are proposed, which allow calculating the degradation of the naturalness of an area due to a specific type of land use. Since the resource ‘nature/naturalness’ is on a larger geographical scale by far not homogeneous, the assessment of land use needs to be regionalised. Therefore, the impact category ‘land use’ has been subdivided into the impact sub-categories ‘land use in European biogeographic regions’. Following the general LCA framework, normalization values for the impact sub-categories are calculated in order to facilitate the evaluation of the characterization results with regard to their share in a reference value. Weighting factors, which enable an aggregation of the results of the different land use sub-categories and make them comparable to other impact categories (e.g. climate change or acidification) are suggested based on the assumption that the current land use pattern in the European biogeographic regions is acceptable.

In this study the environmental impact of a reduced (Nopt-40%) and an optimum (Nopt) N fertilisation in a crop rotation is investigated using the Life Cycle Assessment (LCA) methodology. This method allows for an inventory and evaluation of all environmental impacts associated with the entire crop production system inclusive of all pre-chain processes. The study is based on a long-term field trial with cereals and maize. The study reveals that the Nopt-40% fertilisation is preferable to the Nopt fertilisation concerning climate change, human toxicity, acidification and eutrophication. On the other hand the Nopt application rate shows lower indicator values for abiotic resource depletion, land use, ecotoxicity and formation of photo-oxidants. It can be concluded that none of the compared N fertiliser regimes is clearly preferable from an environmental point of view. To determine a distinct environmentally optimum N application rate, it is first necessary to identify an environmental indicator that summarises all environmental effects.