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Copyright of Revue Internationale PME is the property of Institue de Recherche sur les PME and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

It is a challenge for mathematics teachers to provide activities for their students at a high level of cognitive demand. In this article, we explore the possibilities that history of mathematics has to offer to meet this challenge. History of mathematics can be applied in mathematics education in different ways. We offer a framework for describing the appearances of history of mathematics in curriculum materials. This framework consists of four formats that are entitled speck, stamp, snippet, and story. Characteristic properties are named for each format, in terms of size, content, location, and function. The formats are related to four ascending levels of cognitive demand. We describe how these formats, together with design principles that are also derived from the history of mathematics, can be used to raise the cognitive level of existing tasks and design new tasks. The combination of formats, cognitive demand levels, and design principles is called the 4S-model. Finally, we advocate that this 4S-model can play a role in mathematics teacher training to enable prospective teachers to reach higher cognitive levels in their mathematics classrooms. [ABSTRACT FROM AUTHOR]

The optimization of production processes is even in 2021 still an up-to-date topic, where the use of data is discussed, and the utilization has proven to be effective in specific applications in the last 10 years. Despite increasing access to information directly from the production process and more available computing resources, the data still holds unused potential. Even ongoing digitalization does not replace a deep understanding of the underlying processes and a focus on online automation misses the potential including expertise of shop floor employees. Thus, besides automation and data-driven improvements it is important to support employees with innovative methods to exploit the full potential of the Internet of Things. Principles of gamification offer an opportunity to incorporate the shop floor personnel, to take their full attention on optimization of the process supporting them in their day-to-day job. Appropriate visualization creates incentives for continuous process optimization. [ABSTRACT FROM AUTHOR]

In recent years, the use of student data has become increasingly concerned with management of teacher performance. However, when teachers become aware of specific student data directly related to their approach of teaching, it could inform them about possible strengths, weaknesses or challenges. Unfortunately, teachers generally have little time and encounter significant problems in the interpretation and use of data for change. In this article, we put forward that such problems can be avoided by offering teachers practical frames that are aimed at the interpretation and productive use of student data. We report on an extensive study that was done in the setting of reform implementation where teachers were asked to change their teaching practices. Participating teachers performed multiple PDCA(Plan-Do-Check-Act) cycles in which they designed and taught lessons where student data were collected. To interpret and make use of such student data for change, we provided participants with practical frames. We examined to what extent and in what way participants used these frames and how this influenced professional development. Results showed that participants used frames to both interpret student data and make changes to their teaching practices towards that required by the reform in a stepwise, rather independent way. [ABSTRACT FROM AUTHOR]

We have measured axially channeled Rutherford backscattering spectra of Si[sub 1-x]Ge[sub x] nanofilms in silicon(001). A step in the yield of the host crystal was found for off-normal axes at the depth of the nanofilm. The step was measured as a function of the angle between the incoming beam and the [011] axis and shows two maxima. It is found that Monte Carlo simulations assuming tetragonal distortion reproduce the experimental results. A universal curve was derived which enables determination of the tetragonal distortion from ion-channeling experiments, for a given film thickness. The results are compared with XRD measurements. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Copyright of Pedagogische Studien is the property of Vereniging Onderwijsresearch and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In 2014, potato spindle tuber viroid (PSTVd) was identified in a potato clone originating from a breeding company in the Netherlands. This clone was submitted for micro propagation and therefore tested for PSTVd and a number of other pathogens. This finding of PSTVd initiated actions to track and eradicate the infections. In addition to the finding at the breeding company, PSTVd was also found at a research institute. At both locations the viroid was eradicated following extended testing and discarding of infected plants. Additional surveys including testing of each individual plant in all crossing glasshouses and random samples of pre-basic and basic seed potatoes, revealed no further infections in the Netherlands. This result concurred with the fact that mechanical spread of PSTVd in the field is not likely under climatic conditions in the Netherlands. Therefore, vegetative propagation seems the most important pathway for maintaining and spreading of PSTVd. Based on the evaluation of this outbreak, it was concluded that potato germplasm poses the highest risk of introducing this viroid in potatoes in the Netherlands. [ABSTRACT FROM AUTHOR]

The implementation of educational reforms requires behavioral changes from the teachers involved. Theories on successful behavioral change prescribe the following conditions: teachers need to possess the necessary knowledge and skills, form strong positive intentions to perform the new behavior, and have a supporting environment for change. However, existing approaches to teacher professional development in the context of educational reforms are predominantly aimed at the development of knowledge and skills and at creating a supporting environment, but lack attention to teachers’ intentions to change. In the study described in this article, we performed “motivating-for-educational-change” interviews (MECI) and explored the influence on teachers’ intentions to change in the direction of the proposed national biology education reform, that is, the introduction of a context-based curriculum. The MECI comprised two tools: building on earlier successful experiences and using lesson segments to rearrange instructional approaches. We explored the influence of the MECI technique on the strength and specificity of participating teachers’ intentions. When conducting the MECI, many participants expressed that they now realized how they had already implemented aspects of the reform in their regular instructional approaches. Furthermore, all the participants formulated stronger and more specific intentions to change their regular instructional approach towards that of the proposed reform while taking their regular instructional approach as a starting point. [ABSTRACT FROM AUTHOR]

For understanding and forecasting of hydrodynamics in coastal regions, numerical models have served as an important tool for many years. In order to assess the model performance, we compared simulations to observational data of water temperature and salinity. Observations were available from FerryBox transects in the southern North Sea and, additionally, from a fixed platform of the MARNET network. More detailed analyses have been made at three different stations, located off the English eastern coast, at the Oyster Ground and in the German Bight. FerryBoxes installed on ships of opportunity (SoO) provide high-frequency surface measurements along selected tracks on a regular basis. The results of two operational hydrodynamic models have been evaluated for two different time periods: BSHcmod v4 (January 2009 to April 2012) and FOAM AMM7 NEMO (April 2011 to April 2012). While they adequately simulate temperature, both models underestimate salinity, especially near the coast in the southern North Sea. Statistical errors differ between the two models and between the measured parameters. The root mean square error (RMSE) of water temperatures amounts to 0.72 °C (BSHcmod v4) and 0.44 °C (AMM7), while for salinity the performance of BSHcmod is slightly better (0.68 compared to 1.1). The study results reveal weaknesses in both models, in terms of variability, absolute levels and limited spatial resolution. Simulation of the transition zone between the coasts and the open sea is still a demanding task for operational modelling. Thus, FerryBox data, combined with other observations with differing temporal and spatial scales, can serve as an invaluable tool not only for model evaluation, but also for model optimization by assimilation of such high-frequency observations. [ABSTRACT FROM AUTHOR]

The outer Western Crimean Shelf of the Black Sea is a natural laboratory to investigate effects of stable oxic vs. varying hypoxic conditions on seafloor biogeochemical processes and benthic community structure. Bottom water oxygen concentrations varied between normoxic (175 μmol O2 L-1) and hypoxic (< 63 µmol O2 L-1) or even anoxic/sulfidic conditions within a few kilometres distance. Variations in oxygen concentrations between 160 and 10 µmol L-1 even occurred within hours close to the chemocline at 134 m water depth. Total oxygen uptake, including diffusive as well as fauna-mediated oxygen consumption, decreased from > 15 mmol m-2 d-1 in the oxic zone to < 9 mmol m-2 d-1 in the hypoxic zone, correlating with changes in macrobenthos composition. Benthic diffusive oxygen uptake rates, comprising microbial respiration plus reoxidation of inorganic products, were around 4.5 mmol m-2 d-1, but declined to 1.3 mmol m-2 d-1 at oxygen concentrations below 20 µmol L-1. Measurements and modelling of pore water profiles indicated that reoxidation of reduced compounds played only a minor role in the diffusive oxygen uptake, leaving the major fraction to aerobic degradation of organic carbon. Remineralization efficiency decreased from 100% in the oxic zone, to 50% in the oxic-hypoxic, to 10% in the hypoxic-anoxic zone. Overall the faunal remineralization rate was more important, but also more influenced by fluctuating oxygen concentrations than microbial and geochemical oxidation processes. [ABSTRACT FROM AUTHOR]

The outer Western Crimean Shelf of the Black Sea is a natural laboratory to investigate e_ects of stable oxic vs. varying hypoxic conditions on seafloor biogeochemical processes and benthic community structure. Bottom water oxygen concentrations varied between normoxic (175 µmolO2L-1) and hypoxic (<63 µmolO2 L-1) or even anoxic/sulfidic conditions within a few kilometres distance. Variations in oxygen concentrations between 160 and 10 µmol L-1 even occurred within hours close to the chemocline at 134m water depth. Total oxygen uptake, including di_usive as well as fauna-mediated oxygen consumption, decreased from >15 mmolm-2 d-1 in the oxic zone to <9 mmolm-2 d-1 in the hypoxic zone, correlating with changes in macrobenthos composition. Benthic diffusive oxygen uptake rates, comprising microbial respiration plus reoxidation of inorganic products, were around 4.5 mmolm-2 d-1, but declined to 1.3 mmolm-2 d-1 at oxygen concentrations below 20 µmol L-1. Measurements and modelling of pore water profiles indicated that reoxidation of reduced compounds played only a minor role in the diffusive oxygen uptake, leaving the major fraction to aerobic degradation of organic carbon. Remineralization efficiency decreased from 100% in the oxic zone, to 50% in the oxic-hypoxic, to 10% in the hypoxic-anoxic zone. Overall the faunal remineralization rate was more important, but also more influenced by fluctuating oxygen concentrations than microbial and geochemical oxidation processes. [ABSTRACT FROM AUTHOR]

Philosophy of science education can play a vital role in the preparation and professional development of science teachers. In order to fulfill this role a philosophy of science education should be made practical for teachers. First, multiple and inherently incomplete philosophies on the teacher and teaching on what, how and why should be integrated. In this paper we describe our philosophy of science education (ASSET approach) which is composed of bounded rationalism as a guideline for understanding teachers' practical reasoning, liberal education underlying the why of teaching, scientific perspectivism as guideline for the what and educational social constructivism as guiding choices about the how of science education. Integration of multiple philosophies into a coherent philosophy of science education is necessary but not sufficient to make it practical for teachers. Philosophies are still formulated at a too abstract level to guide teachers' practical reasoning. For this purpose, a heuristic model must be developed on an intermediate level of abstraction that will provide teachers with a bridge between these abstract ideas and their specific teaching situation. We have developed and validated such a heuristic model, the CLASS model in order to complement our ASSET approach. We illustrate how science teachers use the ASSET approach and the CLASS model to make choices about the what, the how and the why of science teaching. [ABSTRACT FROM AUTHOR]

FerryBoxes installed on ships of opportunity (SoO) provide high-frequency surface biogeochemical measurements along selected tracks on a regular basis. Within the European FerryBox Community, several FerryBoxes are operated by different institutions. Here we present a comparison of model simulations applied to the North Sea with FerryBox temperature and salinity data from a transect along the southern North Sea and a more detailed analysis at three different positions located o the English East coast, at the Oyster Ground and in the German Bight. In addition to the FerryBox data, data from a Fixed Platform of the MARNET network are applied. Two operational hydrodynamic models have been evaluated for different time periods: results of BSHcmod v4 are analysed for 2009-2012, while simulations of FOAM AMM7 NEMO have been available from MyOcean data base for 2011 and 2012. The simulation of water temperatures is satisfying; however, limitations of the models exist, especially near the coast in the southern North Sea, where both models are underestimating salinity. Statistical errors differ between the models and the measured parameters, as the root mean square error (rmse) accounts for BSHcmod v4 to 0.92 K, for AMM7 only to 0.44 K. For salinity, BSHcmod is slightly better than AMM7 (0.98 and 1.1 psu, respectively). The study results reveal weaknesses of both models, in terms of variability, absolute levels and limited spatial resolution. In coastal areas, where the simulation of the transition zone between the coasts and the open ocean is still a demanding task for operational modelling, FerryBox data, combined with other observations with differing temporal and spatial scales serve as an invaluable tool for model evaluation and optimization. The optimization of hydrodynamical models with high frequency regional datasets, like the FerryBox data, is beneficial for their subsequent integration in ecosystem modelling. [ABSTRACT FROM AUTHOR]

Oil spill modeling is considered to be an important part of a decision support system (DeSS) for oil spill combatment and is useful for remedial action in case of accidents, as well as for designing the environmental monitoring system that is frequently set up after major accidents. Many accidents take place in coastal areas, implying that low resolution basin scale ocean models are of limited use for predicting the trajectories of an oil spill. In this study, we target the oil spill in connection with the "Full City" accident on the Norwegian south coast and compare operational simulations from three different oil spill models for the area. The result of the analysis is that all models do a satisfactory job. The "standard" operational model for the area is shown to have severe flaws, but by applying ocean forcing data of higher resolution (1.5 km resolution), the model system shows results that compare well with observations. The study also shows that an ensemble of results from the three different models is useful when predicting/analyzing oil spill in coastal areas. [ABSTRACT FROM AUTHOR]

Social entrepreneurship has recently received greater recognition from the public sector, as well as from scholars. However, the lack of a unifying paradigm in the field has lead to a proliferation of definitions. Moreover, several approaches of the phenomenon, as well as different schools of thought, have emerged in different regions of the world. At first glance, because of different conceptions of capitalism and of the government's role, there seems to be a difference between the American and the European conceptions of social entrepreneurship. The objective of this paper is to clarify the concepts of 'social entrepreneurship', 'social entrepreneur' and 'social entrepreneurship organization' and to examine whether there is a transatlantic divide in the way these are conceived and defined. After having justified the need for a definition, we present the different geographical perspectives. North American and European literatures on social entrepreneurship are critically analysed by means of Gartner's four differentiating aspects: the individual, the process, the organization and the environment. We show that there is no clear-cut transatlantic divide, but that, even within the US, different conceptions coexist. We propose definitions for the main concepts associated with social entrepreneurship and, finally, discuss implications for future research. [ABSTRACT FROM AUTHOR]

Oil spill modeling is considered to be an important decision support system (DeSS) useful for remedial action in case of accidents, as well as for designing the environmental monitoring system that is frequently set up after major accidents. Many accidents take place in coastal areas implying that low resolution basin scale ocean models is of limited use for predicting the trajectories of an oil spill. In this study, we target the oil spill in connection with the Full City accident on the Norwegian south coast and compare three different oil spill models for the area. The result of the analysis is that all models do a satisfactory job. The "standard" operational model for the area is shown to have severe flaws but including an analysis based on a higher resolution model (1.5km resolution) for the area the model system show results that compare well with observations. The study also shows that an ensemble using three different models is useful when predicting/analyzing oil spill in coastal areas. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To examine the effectiveness of aripiprazole in schizophrenia in a naturalistic setting in 14 European countries. METHODS: This multicentre, open-label study of aripiprazole evaluated outpatients with schizophrenia for whom a medication switch was clinically reasonable or antipsychotic initiation was required. Patients (n = 833) were randomized in a 4:1 ratio to aripiprazole (recommended starting dose 15 mg/day, permitted adjustment 10-30 mg/day) (n = 680) or another antipsychotic (safety control [SC] group) (n = 153) for 8 weeks. The control group received an antipsychotic different to their recent pre-study medication. The primary effectiveness measure was the Clinical Global Impression - Improvement (CGI - I) score of aripiprazole-treated patients at Week 8 (last observation carried forward [LOCF]). Patients' and caregivers' medication preference was assessed using the Preference of Medication (POM) questionnaire. The Investigator Assessment Questionnaire (IAQ) was used to record investigators' assessments of their patients' responses to the study antipsychotic. Adverse events (AEs) were recorded. RESULTS: At endpoint (Week 8, LOCF), the mean CGI - I score of 3.16 (95% confidence interval, [CI]: 3.04, 3.28) demonstrated the effectiveness of aripiprazole. At endpoint, 43% of aripiprazole-treated patients showed a response (CGI - I score = 1/2). Aripiprazole was rated as slightly or much better than previous antipsychotic at endpoint by 68% of patients and 65% of caregivers. The mean CGI - I score (Week 8, LOCF) for the SC group was 3.37 (95% CI: 3.14, 3.60). No major differences in the occurrence of AEs were noted between aripiprazole- and SC-treated patients. LIMITATIONS: As this is an open-label design, there may have been a bias. Secondly, the study was not powered to show differences between treatment groups and no statistical comparisons were planned. Thirdly, 8 weeks is too short to evaluate long-term effectiveness. CONCLUSIONS: Aripiprazole was effective, well tolerated and well accepted by patients and caregivers in this naturalistic study. [ABSTRACT FROM AUTHOR]

The structures of the α, β and γ polymorphs of quinacridone (Pigment Violet 19) were predicted using Polymorph Predictor software in combination with X-ray powder diffraction patterns of limited quality. After generation and energy minimization of the possible structures, their powder patterns were compared with the experimental ones. On this basis, candidate structures for the polymorphs were chosen from the list of all structures. Rietveld refinement was used to validate the choice of structures. The predicted structure of the γ polymorph is in accordance with the experimental structure published previously. Three possible structures for the β polymorph are proposed on the basis of X-ray powder patterns comparison. It is shown that the α structure in the Cambridge Structural Database is likely to be in error, and a new α structure is proposed. The present work demonstrates a method to obtain crystal structures of industrially important pigments when only a low-quality X-ray powder diffraction pattern is available. [ABSTRACT FROM AUTHOR]

Insight in the biogeochemistry and ecology of sandy sediments crucially depends on a quantitative description of pore water flow and the associated transport of various solutes and particles. Here, we compare and analyse existing models of tracer dynamics in permeable sediments. We show that all models can be derived from a generic backbone, consisting of the same flow and tracer equations. The principal difference between model applications concerns the geometry of the sediment-water interface and the pressure conditions that are specified along this boundary. We illustrate this commonality with four different case studies. These include biologically and physically induced pore water flows, as well as simplified laboratory set-ups versus more complex field-like conditions: [1] lugworm bio-irrigation in laboratory set-up, [2] interaction of bio-irrigation and groundwater seepage on a tidal flat, [3] pore water flow induced by rotational stirring in benthic chambers, and [4] pore water flow induced by unidirectional flow over a ripple sequence. To illustrate the potential of the generic model approach, the same two example simulations are performed in all four cases: (a) the time-dependent spreading of an inert tracer in the pore water, and (b) the computation of the steady-state distribution of oxygen in the sediment. Overall, our model comparison indicates that model development is promising, but within an early stage. Clear challenges remain in terms of model development, model validation, and model implementation. [ABSTRACT FROM AUTHOR]

STUDY OBJECTIVE: To test whether mortality selection was a dominant factor in determining trends in old age mortality, by empirically studying the existence of a negative correlation between trends in late middle age mortality and trends in old age mortality among the same cohorts. DESIGN AND METHODS: A cohort approach was applied to period data on total and cause specific mortality for Denmark, England and Wales, Finland, France, the Netherlands, Norway, and Sweden, in 1950-1999. The study described and correlated mortality trends for five year centralised cohorts from 1895 to 1910 at ages 55-69, with the trends for the same cohorts at ages 80-89. The research distinguished between circulatory diseases, cancers, and diseases specifically related to old age. MAIN RESULTS: All cause mortality changes at ages 80-89 were strongly positively correlated with all cause mortality changes at ages 55-69, especially among men, and in all countries. Virtually the same correlations were seen between all cause mortality changes at ages 80-89 and changes in circulatory disease mortality at ages 55-69. Trends in mortality at ages 80-89 from infectious diseases, pneumonia, diabetes mellitus, symptoms, or external causes showed no clear negative correlations with all cause mortality trends at ages 55-69. CONCLUSIONS: The consistently positive correlations seen in this study suggest that trends in old age mortality in north western Europe in the late 20th century were determined predominantly by the prolonged effects of exposures carried throughout life, and not by mortality selection. [ABSTRACT FROM AUTHOR]

Study objective: To test whether mortality selection was a dominant factor in determining trends in old age mortality, by empirically studying the existence of a negative correlation between trends in late middle age mortality and trends in old age mortality among the same cohorts. Design and methods: A cohort approach was applied to period data on total and cause specific mortality for Denmark, England and Wales, Finland, France, the Netherlands, Norway, and Sweden, in 1950-1999. The study described and correlated mortality trends for five year centralised cohorts from 1895 to 1910 at ages 55-69, with the trends for the same cohorts at ages 80-89. The research distinguished between circulatory diseases, cancers, and diseases specifically related to old age. Main results: All cause mortality changes at ages 80-89 were strongly positively correlated with all cause mortality changes at ages 55-69, especially among men, and in all countries. Virtually the same correlations were seen between all cause mortality changes at ages 80-89 and changes in circulatory disease mortality at ages 55-69. Trends in mortality at ages 80-89 from infectious diseases, pneumonia, diabetes mellitus, symptoms, or external causes showed no clear negative correlations with all cause mortality trends at ages 55-69. Conclusions: The consistently positive correlations seen in this study suggest that trends in old age mortality in north western Europe in the late 20th century were determined predominantly by the prolonged effects of exposures carried throughout life, and not by mortality selection. [ABSTRACT FROM AUTHOR]

This contribution presents total oxygen uptake (TOU) rates and nutrient fluxes of organically poor permeable shelf sands of the German Bight. Measurements have been made in situ with the novel autonomous benthic chamber system Sandy under controlled conditions of advective pore-water exchange. Average oxygen consumption rates of 31.3 ± 18.2 mmol m-2 d-1 measured in this study were relatively high as compared with rates reported from shelf sediments with much higher organic contents. TOU of highly permeable medium and coarse grained sands was substantially enhanced in the presence of advection. This indicates that advective oxygen supply contributed significantly to respiration in these sediments and that advection has to be considered when assessing oxygen consumption and organic matter mineralization in shelf areas. In fine-grained, less permeable sands, no effect of advection could be measured. A lower advective oxygen supply in these sediments is in agreement with a release of ammonium instead of nitrate and a shallower oxygen penetration depth. Scaled up to the entire German Bight, the results imply that in 40% of the area an effect of advection on benthic oxygen uptake and other advection-related processes can be largely excluded, while in the remaining 60% significant pore-water advection potentially takes place. However, because permeabilities of the sediments investigated in this study were widely spaced, a significant effect on oxygen supply was only verified for highly permeable sands that are likely to cover approximately 3% of the area. [ABSTRACT FROM AUTHOR]

This contribution introduces the benthic chamber system Sandy that was developed for studying in situ solute fluxes in permeable sandy sediments where advective pore-water transport can dominate solute exchange across the sediment--water interface. The Sandy system can be deployed at the seafloor, where it autonomously performs measurements of sediment--water solute fluxes. The innovative features include an insertion mechanism that permits gentle and deep penetration of the chamber into hard consolidated sands with minimum disturbance, and an adjustable stirrer that generates a rotationally symmetric pressure gradient between the center and the circumference of the enclosed sediment surface. In contrast to similar systems, Sandy takes advective pore-water exchange into account. Through adjustment of the stirring rate, defined pressure gradients can be established that are similar in shape and magnitude to natural pressure gradients that develop at topographical structures of current-exposed sediment surfaces. Solute fluxes measured in the chamber at a specific "advective" stirrer setting can be compared with those obtained at reduced stirring, where pressure gradients are absent and solute exchange therefore is restricted to diffusion and bioirrigation. Rates of pore-water exchange that were determined by means of tracer experiments at different stirrer settings in natural coarse-grained North Sea deposits demonstrate the feasibility of this approach. This permits, for the first time, an evaluation of the contribution of advective exchange to the total interfacial solute flux in situ and makes Sandy a valuable tool to study advection-related processes in permeable shelf sediments. [ABSTRACT FROM AUTHOR]

Catalytic activity of platinum catalysts such as Pt/graphite, Pt/TiO2, Pt/Al2O3, and Pt/active carbon was studied using a slurry phase CSTR. Three model reactions, namely, phenol, maleic acid, and malonic acid oxidation were investigated in the temperature range from 120 to 170 °C and at a total reactor pressure of 1.7 MPa. Platinum on graphite was found to be most suitable for aqueous phase oxidation of phenol, maleic acid, and malonic acid. Complete conversion for both phenol oxidation as well as maleic acid oxidation to CO2 was observed with Pt/graphite at stoichiometric oxygen excess close to 0% and at 150 °C. Deactivation due to over-oxidation is gradual for Pt/graphite with a metal dispersion of 5.3% as compared to Pt/TiO2, Pt/Al2O3 and Pt/AC, which have metal dispersions of 15.3%, 19.5% and 19.0%, respectively. It was further found that in the presence of Pt/graphite catalyst and oxygen, malonic acid reaction proceeds via non-catalysed decarboxylation, and catalytic decarboxylation to CO2 and acetic acid, and catalytic oxidation to CO2 and H2O. Acetic acid was found to be difficult to oxidise at temperatures below 200 °C. [ABSTRACT FROM AUTHOR]

Abstract Background Unsaturated fatty acids are known as neutrophil activators. In the present study we investigated whether saturated triglycerides and fatty acids may also contribute to the previously observed activation of neutrophils by nutritional lipid emulsions. Furthermore we tested the hypothesis that carbon-chain length is of importance in this respect. Materials and methods Neutrophils (1 × 106 mL-1 ) were isolated from the blood of nine volunteers. Chemiluminescence was used to evaluate neutrophil activation, characterized by the production of oxygen radicals by neutrophils during incubation with 1 mmol L-1 saturated fatty acid (6–20 carbon) or triglycerides (6–12 carbon fatty acid), dissolved in aqueous medium by preparing micelles with dipalmitoyl phosphatidylcholine (DPPC). Results were expressed as means ± SEMs of the overall luminescence signal relative to the signal of cells incubated in medium. Results Similar to a positive control, the polyunsaturated fatty acid arachidonic acid (C20 : 4), the triglycerides tricaproin (TC6 : 0), tricaprylin (TC8 : 0) and trilaurin (TC12 : 0) as well as the fatty acids lauric acid (C12 : 0), palmitic acid (C16 : 0), stearic acid (C18 : 0) and arachidic acid (C20 : 0) all induced oxygen radical production in neutrophils, while the medium-chain triglyceride tricaprin (TC10 : 0) and fatty acids caproic acid (C6 : 0), caprylic acid (C8 : 0) and capric acid (C10 : 0) exerted no clear effects, similar to negative controls (DPPC and glycerol). Conclusions Besides their (poly)-unsaturated counterparts, saturated triglycerides and fatty acids also activate neutrophils. Carbon chain-length is pivotal in the interaction of fatty acids and triglycerides and cells of the immune system. [ABSTRACT FROM AUTHOR]

Presents information on a study which investigated the concept of delivery splitting. Cost savings obtained by suppliers using the concept of delivery splitting; Model description; Numerical validation; Conclusions.

Copyright of Ocean Dynamics is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Focuses on a study which considered the determination of the reorder point s in an (R, s, Q) inventory model subject to fill rate service level constraint. (R, s, Q) model description; Details on compound renewal method and discrete time method; Experiments which compared the reorder point s calculated by both methods and the associated actual service level; Conclusion.

A temperature induced helix inversion in a single component system has been observed by investigating a lattice system of chiral molecules using Monte Carlo (MC) computer simulations. The molecules were considered to interact as derived by van der Meer et al. taking into account fourth-order terms describing an anharmonic interaction. On cooling from an isotropic system, a cholesteric phase with a temperature dependent pitch was obtained. The cholesteric phase changed its handedness through an infinite-pitch system as a function of temperature. The study of systems with a small chiral energy contributionnd a large pitch was enabled using self-determined boundary conditions. [ABSTRACT FROM AUTHOR]

The 'Gregg phenomenon' implies that myocardial function and oxygen consumption ( $$M\dot VO_2 $$ ) increase when coronary perfusion is enhanced within or above the autoregulatory range. We have recently demonstrated that the 'Gregg phenomenon' has no significance for regional myocardial function and $$M\dot VO_2 $$ in anesthetized swine in situ. There is, however, some evidence that the 'Gregg phenomenon' may exist within stunned myocardium. To test whether coronary hyperperfusion increases regional myocardial function and $$M\dot VO_2 $$ in stunned myocardium, in six anesthetized swine the left anterior descending coronary artery (LAD) was cannulated and perfused at constant pressure (CAP) using an extracorporal circuit. The coronary vein which parallels the LAD was cannulated to allow measurement of regional $$M\dot VO_2 $$ and regional systolic wall thickening (WT%) of the anterior myocardium was assessed using sonomicrometry. Blood flow (CBF) to the LAD was increased by increasing CAP within the extracorporal circuit or by intracoronary adenosine infusion (150 μg/min). In normal myocardium, increasing CBF from 71.4 ± 19.7 (SD) to 156.7 ± 48.8 ml/min/100 g by increasing CAP from 100 ± 10 to 190 ± 10 mm Hg or increasing CBF from 75.1 ± 29.1 to 189.2 ± 45.8 ml/min/100 g by intracoronary adenosine infusion did not increase WT% (34.3 ± 12.2 % vs 32.1 ± 10.6 % and 32.3 ± 10.7 % vs 30.1 ± 13.2 %, respectively). $$M\dot VO_2 $$ was not changed during enhanced CAP (6.94 ± 1.05 vs 8.10 ± 1.08 ml/min/100 g) and during intracoronary adenosine infusion (6.67 ± 1.45 vs 7.30 ± 2.23 ml/min/100 g). Twenty min of hypoperfusion followed by 30 min of reperfusion depressed WT% by 47 % (p < 0.05). However, $$M\dot VO_2 $$ was only decreased by 23 % (NS). In the stunned myocardium, increasing CBF from 62.1 ± 36.4 to 157.1 ± 60.0 ml/min by increasing CAP was not associated with an increase in WT%. $$M\dot VO_2 $$ , however, increased from 5.14 ± 1.07 to 8.88 ± 1.83 ml/min/100 g (p < 0.05). Comparable results were achieved when CBF was increased from 60.3 ± 28.7 to 176.9 ± 48.5 ml/min by intracoronary adenosine infusion. WT% was unaffected, while $$M\dot VO_2 $$ increased from 4.69 ± 0.92 to 9.46 ± 3.39 ml/min/100 g (p < 0.05). Thus, increasing coronary perfusion within or above the autoregulatory range increases $$M\dot VO_2 $$ in stunned myocardium, but without a simultaneous increase in regional myocardial function. [ABSTRACT FROM AUTHOR]

Copyright of Zeitschrift für Kinderheilkunde is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)