Development of transient habitat modeling for stream Macrozoobenthos

In addition to the hydromorphological pressure on the ecological conditions of free-flowing river courses, increasing water temperature is affecting the water bodies, particularly by changing freshwater community compositions. The low discharge of numerous European rivers in the dry and hot hydrological year 2022 proves this relevance. Therefore, ecological assessment tools such as habitat modeling should take these factors into account when assessing the quantity and quality of habitats. In this paper, the habitat modeling tool “Transient River Habitat Modeling for Macrozoobenthos” (TRiMM) is improved by incorporating a fuzzy logic approach and adding water temperature to the set of parameters determining habitat suitability for macrozoobenthos. Habitat-relevant parameters, including hydromorphological factors (depth, velocity, mineral and organic substrate) and a water quality factor (temperature), are combined in the habitat model so that it can more broadly characterize river physical conditions and their interactions with biological indicators. Habitat modeling employed the mentioned parameters to simulate suitability for the macrozoobenthos in a small river in central Saxony, Germany. Due to its deteriorated condition, this river was selected as a representative for thousands of kilometers of small rivers across the region, which have been restored. The model simulated the status quo of river conditions from spring to summer for three macrozoobenthos species (Ancylus fluviatilis, Ephemera danica and Gammarus fossarum). The results showed that the natural flow resulted in dynamic habitat suitability both spatially and temporally, which differs for each species. Remarkably, the five-parameter model (depth, velocity, temperature, mineral, and organic substrate) generally performed better compared to a similar model without temperature.     

Gesundheitsethische Kenntnisse im Verlauf der Pflegeausbildung – Ergebnisse einer Querschnittsstudie in Deutschland

Background and Aims

The provision of knowledge in nursing ethics enables future nurses to contribute to the health professional’s decision-making processes when it comes to ethical issues in nursing. This paper is a report of a study on the development of moral positions as well as student nurses’ knowledge of nursing ethics.

Methods

Within the context of a panel study, we conducted the first cross-sectional study collecting data of student nurses at two nursing schools (Berlin and Fürth) between August 2010 and March 2011. The study used a structured questionnaire. Participation in the study was voluntary. Prior to the study, all participants had attended classes in nursing ethics to varying degrees.

Results

At both locations, participants showed increased knowledge of nursing ethics. At the same time, students who had not gained any practical experience with euthanasia to date had difficulties finding a theoretical approach to corresponding measures. There was a general trend in all participants to advocate the shared-decision model, and hence to promote patient autonomy. At the same time, patients’ capacity to make competent decisions about their medical care was estimated as being low.

Conclusion

Education in nursing ethics has great potential for imparting knowledge, thus increasing the development of personal ethical competence. Our results raise the question of whether incorporation of practical experience with nursing ethical issues is required to guarantee practice-oriented and scientifically sound knowledge.     

Motion of nano-objects on polymer brushes

In this paper we review a new method to move nano-objects on a polymer surface that is made from diblock-copolymer and mixed brushes. Such brush systems consist of polymer chains covalently attached to a surface with high grafting density. If the two polymeric components the brush consists of are incompatible with each other, it shows microphase separation into nanopatterns of well defined size. Such a system possesses the unique property of changing the surface topography in response to different external conditions. Motion of nano objects adsorbed on the brush is induced by having the external conditions and thus the brush topography vary over time. This is shown by studying the distribution of silica nanoparticles adsorbed on several types of brushes while changing the external conditions. We identify parameters required for motion of nano objects, and discuss potential applications of the proposed technique for nano engineering.     

Mycotoxins in foodstuffs VI. Formation of sterigmatocystin in bread by Aspergillus versicolor

Sterigmatocystin was formed on different kinds of bread (whole wheat bread, whole rye bread, whole rye bread with shredded wheat, whole wheat bread with wheat germs and whole wheat bread with linseed) by two strains ofAspergillus versicolor. The highest yields were in the range of 0,1–0,4 rg/g. The growth of the moulds and the toxin production were influenced by the total acid content (Säuregrad; must be less than approximately 9) and by the temperature (optimal growth temperature: 20–30° C, optimal temperature for toxin synthesis: 20° C). After 10 days of incubation most of the toxin was already formed.     

Fatigue of Lead Zirconate Titanate Ceramics II: Sesquipolar Loading

Piezoelectric actuators generally are driven with unipolar electric load cycles. Although the obtainable strain is increased by small excursions into the negative field regime, this type of load cycle is rarely considered, as its long-time reliability has been questioned. Here, we investigate the degradation of lead zirconate titanate during cycling between high positive and low negative electric fields. Measurements of the large and small signal parameters are used to quantify changes of the material. The fatigue behavior shifts from one best described with existing models of unipolar fatigue to bipolar-like fatigue with increasing field amplitude.     

Photo cross-linkable poly(N-isopropylacrylamide) copolymers III: micro-fabricated temperature responsive hydrogels

Micro-fabricated temperature responsive poly(N-isopropylacrylamide) (PNIPAAm) hydrogels were produced by photolithographic patterning of photo cross-linkable polymers. These polymers were synthesized by copolymerization of N-isopropylacrylamide (NIPAAm) and 2-(dimethyl maleimido)-N-ethyl-acrylamide (DMIAAm). The patterning process of polymers with 9.2 mol% DMIAAm and film thickness below 5 μm in the dry state was able to depict a lateral resolution of 4 μm with insignificant shape change. In order to increase the adhesion of the swollen hydrogels, and thus, the resolution of a particular pattern, a special adhesion promoter based on a monochlorosilane anchor group and a chromophore head group was synthesized. If a silicon wafer surface was pretreated with the adhesion promoter, the structures were stable and well adhered even at lower cross-linking densities. The hydrogels are suitable as working substances for micro-actuators because of their thermally induced volume changes. The swelling ratio of the pattern at low temperatures increased with a decreased cross-linking density. As expected from the chemical composition of the gels, the phase transition temperature (T_c) decreased with increasing DMIAAm content. The swelling of microstructures in water in comparison to macroscopic objects occured significantly faster. This behavior was attributed to the small gel dimension but it was even more pronounced because of the sponge-like nanostructure of the hydrogels characterized by high-resolution field emission scanning electron microscopy. Suitable applications of these hydrogels are adjusting limbs in fluid micro-systems such as micro-pumps and micro-valves.     

Untersuchungen zur übermolekularen Struktur in Polybutylenterephthalat/Polycarbonat-Blends

Light-microscopic, X-ray and calorimetric investigations were carried out to characterize the morphology of melt-mixed poly(butylene terephthalate)(PBT)/polycarbonate(PC)-blends. A completely spherulitic structure up to a concentration of about 20 wt.-% PC was found by polarizing microscopy. A second separate, amorphous phase appears at higher PC concentrations. By differential scanning calorimetry, a shift of the glass transition temperature of PBT as well as PC, a slight melting point depression of the crystalline PBT-phase and different crystallization temperatures depending on the concentration of the pure components were measured. Wide-angle X-ray studies and additional density measurements gave reason to believe that the crystallinity of PBT in the blend is decreasing and that there is a possibility of crystallization of PC, particularly by a thermal post-treatment.     

Ärztliches Handeln bei Mittelknappheit

Background

Financial resources in German and international health care systems are limited. Financial scarcity leads to medical, economical, judicial, and ethical problems in medical decision making. These problems will probably increase in the following years. From an ethical point of view the challenges of just allocation of scarce resources and moral conflicts of clinical decision makers are of special importance. Qualitative research allows the investigation of how different physicians deal with clinical decision making in the face of financial scarcity and what kind of ethical dilemmas occur.

Method

We conducted semi-structured in-depth interviews with fifteen senior and chief clinicians in the fields of intensive care and cardiology at five German primary, secondary, and tertiary care hospitals. All interviews were audio taped, transcribed verbatim and analysed using open and axial coding from the grounded theory approach.

Results

The physicians reported a wide and heterogeneous range of influencing factors, strategies and consequences when explaining the daily practice of dealing with scarce resources. Prioritization criteria such as effectiveness or cost-effectiveness were interpreted differently between physicians and thus might lead to inconsistent allocation decisions. At the same time our research confirmed that physicians do not trifle with rationing decisions. In contrast, financial scarcity and the related practical and theoretical challenges of allocation can lead to moral conflicts, emotional distress and experiences of excessive demands.

Conclusion

Practical recommendations and ethical frameworks that aim to guide and change the clinical practice of decision making in the face of financial scarcity should acknowledge the influencing factors and consequences that are presented systematically in this article.