Diskussion ethischer Aspekte zahnärztlicher Altersschätzung bei jungen Flüchtlingen durch Röntgendiagnostik

Definition of the problem

An increasing number of young refugees whose ages are not reliably known is thrusting the problem of medical and dental age estimation via x?ray examinations to the forefront of public discussion. Despite continual criticism of the organised German medical profession for this procedure and its associated radiation exposure for nonmedical purposes, x?raying the carpal bone, the clavicle or the teeth to determine age remains common practice. Consequently, the official verification of asylum seekers’ ages has considerable ramifications since refugee minors have particular rights.

Arguments

In previous discourse(s) about the proportionality of approximating the age of young asylum seekers via x?rays, the relevance of the radiological examination of the wisdom teeth is indeed always referred to; however, the specific role of dentists is by comparison rarely discussed from a medical–ethical perspective. As a matter of fact, in 2001 and 2008 the Deutsche Gesellschaft für Zahn-, Mund- und Kieferheilkunde (DGZMK; English: German Association for Dentistry, Stomatology and Orthodontics) published scientific position papers in which the comprehensive radiological verification of the age of young refugees is endorsed – with the distinct omission of an ethical discussion.

Conclusion

In light of these disparate findings, it should be investigated just how suitable, necessary and ethically appropriate dental procedures for the purposes of age determination are. The methodical foundations of this paper are (1) a comprehensive evaluation of available specialist literature, in addition to (2) a critical normative analysis of the main arguments presented by the named specialist society. Especially ethically discussing these position papers is a desideratum for ethics in dentistry. This discussion also serves as an opportunity to apply the international debate on age determination to Germany’s framework.

     

Oral tissue response to ovine grafting biomaterial: Morphological and morphometric study using scanning electron and light microscopy tissue response to ovine grafting biomaterial

OBJECTIVE: To evaluate the oral tissue response to an experimental particle ovine biomaterial by scanning electron microscopy (SEM) and light microscopy (LM). MATERIAL AND METHODS: Forty‐eight rats had surgical periodontal defects treated with either blood clotting (control), bovine biomaterial? (B), or an experimental ovine biomaterial (O). Data from SEM analysis (defect exposure, root surface exposure, diameter of matrix fibers and bundles, and globuli areas; n = 5) were applied to Shapiro–Wilk, Kruskal–Wallis, and Dunn's test, whereas LM analysis (tissue cicatrization characteristics and diameter defect; n = 3) had data applied to two‐way analysis of variance. Animals were monitored for 1 and 3 weeks. RESULTS: By SEM, the O samples showed significant differences from B and C in the area of defect exposure (H_2,15 = 8.66; P < 0.05). In both periods, O and B samples showed similar results for matrix fiber diameters, differently than C samples (H_2,15 = 14.0; P < 0.05). All other SEM variables were considered equivalent among the groups (P > 0.05). Under LM, an acute and chronic granulomatous inflammation was seen in the presence of both biomaterials (B and O, 1 week); both the control and the ovine grafting samples showed mature bone in the repair site (3 weeks); the defect diameter showed similar values among groups, at both monitoring periods (F_2,12 = 1.0401; P > 0.05). CONCLUSION: The ovine particles of this study showed a favorable response to oral tissue repair, demonstrating to be a potential source for the development of bone grafting biomaterials. Microsc. Res. Tech. 2012. © 2012 Wiley Periodicals, Inc.     

Ultrastructural changes in the ovary cells of engorged Rhipicephalus sanguineus female ticks treated with esters of ricinoleic acid from castor oil (Ricinus communis)

Rhipicephalus sanguineus is a widely distributed tick species that has adapted to the urban environment, and the dog is its main host. This species is also known as a vector and reservoir of diseases caused by bacteria, protozoa, and viruses. Currently, acaricides of synthetic chemical origin have been widely and indiscriminately used, leading to the development of resistance to these products by ticks and causing damage to the environment. Thus, these issues have made it necessary to seek other forms of controlling these ectoparasites. R. sanguineus was artificially infested in host New Zealand White rabbits, which were divided into four treatment groups: control (CG1 and CG2) and treatment (TG1 and TG2) groups. TG1 and TG2 hosts were provided with feed supplemented with esters of ricinoleic acid from castor oil at a concentration of 5 g/kg of feed for 7 and 15 days. Afterward, the ovaries of the female ticks were removed for analysis by transmission electron microscopy. The results showed ultrastructural changes in the somatic and germ cells of ovaries from TG1 and TG2 females, particularly with respect to chorion deposition, a protective membrane of the oocyte, as well as in the transport process of vitellogenic materials via the hemolymph and pedicel cells. Moreover, the mitochondria were less electron-dense and had cristae that were more disorganized than the mitochondria from CG1 and CG2 individuals. Thus, this study demonstrated the action of esters on the ovaries of R. sanguineus, signaling the prospect of a way to control this ectoparasite without affecting nontarget organisms or the environment.     

Fipronil (active ingredient of acaricide Frontline®) acting on the mice thyroid

Fipronil, active ingredient of Frontline® acaricide, is a phenyl‐pyrazolic derivative, and its efficacy in the elimination of several plagues, even in lower concentrations, has already been demonstrated; however, its effect on nontarget organisms has not been thoroughly explained. In this sense, the present study had the objective to evaluate the effects of different doses of fipronil in mice and determine its cytotoxic potential and possible compromises on nontarget organisms in artificial conditions. The results showed that animals exposed to fipronil presented significant alterations in the thyroidean tissue with evident follicular disorganization, decreased in the size of most follicles culminating with the rupture of smaller follicles and still with posterior fusion in a big and irregular “follicle” filled with colloid. The present study also revealed that the action of fipronil not only causes disorganization in the thyroidean tissue but alsoalters the chemical composition of the colloid itself (prehormone), modifying its proteic basis, which was confirmed by histochemical test for protein detection, making it clear that, in thyroids exposed to fipronil, the colloid was weakly positive or even negative for the presence of proteins in its constitution. Microsc. Res. Tech. 2011. © 2011 Wiley Periodicals, Inc.     

On the completeness of the semigraphoid axioms for deriving arbitrary from saturated conditional independence statements

Conditional independence (CI) statements occur in several areas of computer science and artificial intelligence, e.g., as embedded multivalued dependencies in database theory, disjunctive association rules in data mining, and probabilistic CI statements in probability theory. Although, syntactically, such constraints can always be represented in the form I(A,B|C)$I(A,B|C)$, with A, B, and C subsets of some universe S, their semantics is very dependent on their interpretation, and, therefore, inference rules valid under one interpretation need not be valid under another. However, all aforementioned interpretations obey the so-called semigraphoid axioms. In this paper, we consider the restricted case of deriving arbitrary CI statements from so-called saturated ones, i.e., which involve all elements of S. Our main result is a necessary and sufficient condition under which the semigraphoid axioms are also complete for such derivations. Finally, we apply these results to the examples mentioned above to show that, for these semantics, the semigraphoid axioms are both sound and complete for the derivation of arbitrary CI statements from saturated ones.     

Photopolymerized low‐surface‐energy coatings based on a novel fluorinated ether acrylate

The synthesis, characterization, and polymerization of a perfluoroalkyl ether substituted methacrylic acid (C8F7) were investigated. C8F7 was photopolymerized at different temperatures, higher double‐bond conversions being achieved at higher polymerization temperatures. The polymerization rates were fast in comparison with those of typical methacrylate esters. Thermogravimetric analysis of the obtained polymers showed thermal stabilities up to 270–290°C. The initial degradation at 200°C involved the loss of water and the partial loss of the perfluoroalcohol via the intramolecular formation of anhydride and lactone groups. The surface properties of coatings obtained with C8F7 coatings on various substrates were evaluated with water and hexadecane contact‐angle measurements, which confirmed that low‐surface‐energy polymeric coatings were obtained. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3301–3314, 2004     

Morphological organization of the dorsal protuberance of Linepithema humile (Mayr, 1868) ant's larvae (Hymenoptera, Formicidae)

The Argentine ant Linepithema humile is an important invasive species because of the levels of infestation that it can reach; however, there is little information about its presence, histological organization, and function of the dorsal protuberance, which is found exclusively in their larvae. The objective of this study was to describe it in L. humile through scanning electron microscopy and transmission electron microscopy, bringing information about this structure. The epidermis of these larvae have cuticles covering the whole body, and is formed by a sequence of overlapping lamellas where the inner ones were thicker and presented lower electron density, whereas the outer ones were thinner and highly electron dense. Pores or pore-like channels were not observed. A thick and acellular region composed of granular material was found under the cuticular layer. Out of this region, the flattened epidermic cells formed an epithelial layer. For the dorsal protuberance region, these cells become prismatic, and similarly to the cuticle, presents significant thickening. These cells presented extended microvilli, as well as a great amount of lamellar rough endoplasmic reticulum. Under this epithelium was observed a concentration of fat body cells, more numerous in the dorsal protuberance region. This study indicated that the dorsal protuberance present in the first segment of L. humile larvae has apparently no secretory function because no pores were found. This fact allowed to conclude that in L. humile larvae the dorsal protuberance would have the function to make it easier for the worker ants to carry them within the colony.     

Topology optimization based on finite strain plasticity

In this paper infinitesimal elasto-plastic based topology optimization is extended to finite strains. The employed model is based on rate-independent isotropic hardening plasticity and to separate the elastic deformation from the plastic deformation, use is made of the multiplicative split of the deformation gradient. The mechanical balance laws are solved using an implicit total Lagrangian formulation. The optimization problem is solved using the method of moving asymptotes and the sensitivity required to form convex separable approximations is derived using a path-dependent adjoint strategy. The optimization problem is regularized using a PDE-type filter. A simple boundary value problem where the plastic work is maximized is used to demonstrate the capability of the presented model. The numerical examples reveal that finite strain plasticity successfully can be combined with topology optimization.     

Variable Resolution Search with Quadrotors: Theory and Practice

This paper presents a variable resolution framework for autonomously searching stationary targets in a bounded area. Theoretical formulations are also described for using a probabilistic quadtree data structure, which incorporates imperfect Bayesian (false positive and false negative) detections and informs the searcher's route based on optimizing information gain. Live‐fly field experimentation results using a quadrotor unmanned aerial vehicle validate the proposed methodologies and demonstrate an integrated system with autonomous control and embedded object detection for probabilistic search in realistic operational settings. Lessons learned from these field trials include characterization of altitude‐dependent detection performance, and we also present a benchmark data set of outdoor aerial imagery for search and detection applications.     

Pushing personhood into place: Situating media in rural knowledge in Africa

Designing interactions with technologies that are compatible with rural wisdom and skills can help to digitally enfranchise rural people and, thus, contribute to community cohesion in the face of Africa's urbanization. Oral information has been integral to rural identity and livelihood in Africa for generations. However, the use of technology can inadvertently displace the knowledge of communities with practices that differ from the knowledge traditions in which technology is designed. We propose that devices that are sensitive to users' locations, combined with platforms for social networking and user-generated content, offer intriguing opportunities for rural communities to extend their knowledge practices digitally. In this paper we present insights on the way rural people of the Herero tribe manage information spatially and temporally during some of our design activities in Namibia. We generated these insights from ethnography and detailed analysis of interactions with media in our ongoing Ethnographic Action Research. Rural participants had not depicted their wisdom graphically by photography or video before, rarely use writing materials and some cannot read. Thus, we gathered 30 h of observer-and participant-recorded video and participants' interpretations and interactions with thumbnail photos from video, photography and paper. We describe insights into verbal and bodily interactions and relationships between bodies, movements, settings, knowledge and identity. These findings have made us more sensitive to local experiences of locations and more aware of assumptions about space and time embedded in locative media. As a result, we have started to adopt an approach that emphasizes connectors rather than points and social–relational and topokinetic rather than topographic spaces. In the final section of the paper we discuss applying this approach in design by responding to the ways that participants use social relationships to orient information and use voice, gesture and movement to incorporate locations into this “dialogic”. In conclusion we outline why we hope our reflections will inspire others to examine the spatial, temporal and social affordances of technologies within the bonds of rural, and other, communities.