Analysis of the biomechanical response of kidneys under blunt impact

OBJECTIVE: This study addresses the biomechanical response of isolated kidneys to traumatic insult. METHODS: Kidneys were subjected to blunt impact by using a freely swinging right cylindrical pendulum. Force-deformation characteristics were derived for 65 impacted adult pig kidneys. Renal injuries were classified by autopsy, and an injury risk analysis was performed. In addition a finite element model that simulated the experiments was implemented. RESULTS/CONCLUSIONS: The kidneys showed a viscoelastic response. An energy-based injury threshold was identified, with a strain energy density of 21 kJ/m(3) corresponding to a 50-percent risk of renal injury level AIS3 or higher. Finally, the impact tests were simulated using a finite element model of the kidney to investigate relevant injury mechanisms. The model predicted the renal capsule and underlying parenchyma to first fail at an impact energy level of 4.0 J, consistent with experimental results.     

Iron interference on matrix-assisted laser desorption/ionisation time-of-flight mass spectra of condensed tannins

Matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) was used to reveal the influence of iron on the detectability of condensed tannins extracted from Picea abies. Iron chloride mixed with condensed tannins suppresses the detection of tannins by MALDI-TOF MS in a dose-dependent manner. Total suppression is observed at concentrations of 250 and 500 mg FeCl₃ g^–1 of sample. At lower concentrations, spectrum quality is still greatly reduced, but short chain tannins are detected. At 100 mg FeCl₃ g^–1 of sample, iron increased the intensity of the tannin galloyl ester peaks above those of the corresponding tannin polymers. This points to an antagonistic effect of the galloyl ester moiety on iron complexation with condensed tannins and, thus, their reduced susceptibility to iron interference during MALDI-TOF MS.     

Clutch loss affects the operational sex ratio in the strawberry poison frog Dendrobates pumilio

Both modelling and field data from three breeding seasons show that an environmental factor, clutch loss (CL), affects the operational sex ratio (OSR) and therefore male mating frequency in strawberry poison frogs. Clutch loss affects the length of reproductive cycles of both sexes: with increasing clutch losses, males spend proportionately more time than females in parental investment activities. Because of this, males spend relatively less time in the mating pool, i.e. exhibit proportionately more time-out than females in comparison to a situation with low or no clutch loss. Hence, clutch loss leads to a less male-biased OSR, coupled with a decrease in the opportunity for sexual selection. Furthermore, this study resolves an apparent paradox, the negative correlation between mating frequency and reproductive success (=number of produced tadpoles) of individual males in one breeding season. Clutch loss decouples the correlation between mating frequency and reproductive success because females re-enter the mating pool when they lose their offspring. However, clutch loss diminishes the reproductive output. Similar consequences of clutch loss on the OSR may be true for many species where both sexes reproduce frequently in one breeding season.Communicated by J. Christensen-Dalsgaard     

The EU-project ERAPharm. Incentives for the further development of guidance documents?

- Triggered by the detection of a large variety of pharmaceuticals in surface waters, soils and groundwaters across the world (e.g. Halling- Sørensen et al. 1998, Daughton & Ternes 1999, Jones et al. 2001, Heberer 2002) and the widespread occurrence of endocrine active compounds and related effects in the environment (e.g. Purdom et al. 1994, Tyler et al. 1998, Vethaak et al. 2002), pharmaceuticals in the environment have become an issue for both the scientific and the public community. During the last few years, our understanding of the fate and effects of pharmaceuticals in the environment has progressed significantly. However, there are still a number of uncertainties concerning the effects of pharmaceuticals on the environment and the assessment of potential exposure (e.g. Hanisch et al. 2004, Salomon 2005). These uncertainties will be addressed by the EU-project ‘Environmental risk assessment of pharmaceuticals’ (ERAPharm). This project, a specific targeted research project, is carried out within the priority ‘Global change and ecosystems’ of the 6th framework programme of the European Union. ERAPharm has started on 1st October 2004; the project duration is three years.     

Consensus Conferences – A Case Study: Publiforum in Switzerland with Special Respect to the Role of Lay Persons and Ethics

This paper focuses on experiences from a case study dealing with the Swiss type of a consensus conference called “PubliForum” concerning “Genetic Technology and Nutrition” (1999). Societal and ethical aspects of genetically modified food meanwhile can be seen as prototypes of topics depending on the involvement of the public through a participatory process. The important role of the lay perspective in this field seems to be accepted in practice. Nevertheless, there is still some theoretical controversy about the necessity and democratic legitimacy of participatory processes in general, and especially about those dealing with technological or environmental problems (sustainable development) concerning society. From an ethical point of view, a lot of heterogeneous problems concerning contents and procedures of public participation can be pointed out, not only on the theoretical level but also in practice, e.g., concerning the communication process between laypersons and experts. The intention of our paper is to give hints and to clarify criteria that support the communication process leading to a dialog of autonomous citizens and which especially consider ethical aspects in the field. One important result is that there must be an orientation for all members of a consensus conference having clear rules and knowing their different roles that support transparency, credibility, and fairness of the whole procedure and a “good product”: a substantial final document or citizens’ report. This paper presents results of the project Ethical Bio-TA Tools as funded by the European Commission, DG Research, under FP5, Quality of Life Programme.     

Species recognition and species isolation in wandering spiders (Cupiennius spp.; Ctenidae)

Summary One of the roles ascribed to spider courtship is that of mate recognition and reproductive isolation. We describe behavioral mechanisms underlying these functions in three species of wandering spiders of the genus Cupiennius (Ctenidae). C. salei and the two sympatric species C. getazi and C. coccineus discriminate conspecifics and heterospecifics in a multistage process which covers three principal phases of courtship: (1) Chemical phase: male spiders initiate vibratory courtship communication less often upon contact with heterospecific than with conspecific female silk. (2) Vibratory phase: females respond with their own vibration less often and with increased delay to the vibratory courtship signals of heterospecific males than to those of conspecific males. (3) Tactile phase: in heterospecific pairings males and females interrupt the contact phase if their courtship has progressed thus far. The product of the probabilities of passing through each of the different stages of courtship is between 0.44 and 0.88 for conspecific pairings, but zero for most heterospecific pairings. This is to a greater extent due to the behavioral barriers of the vibratory and the tactile phase than to that of the chemical phase. Male taxis on tracks of female silk does not depend on the species-specificity of the silk. Female vibrations are not essential for species recognition: males increase their signal rates, orient toward and approach responding females in both con- and heterospecific pairings. Female attacks on males are similar to attacks on prey; males defend themselves with outstretched front legs and are caught and killed by the female in only 5% of the cases. In all phases of courtship, female C. salei are least and female C. getazi most selective. When female C. coccineus and C. getazi are involved in heterospecific pairings no copulation is attempted. In contrast, 13 copulations of C. salei with males of the other two species were observed; egg sacs never resulted from these copulations. Among males, those of C. getazi were least selective. The likelihood of heterospecific pairs passing through all phases of courtship is higher in case of the allopatric than in that of the sympatric species. This finding applies to the courtship as a whole, but not necessarily to each of its phases.Offprint requests to: F.G. Barth