The passage from the integral to the rational group ring in algebraic K-theory

In this dissertation we investigate a conjecture proposed by W. Lück and H. Reich that asserts for an arbitrary group G that the map K_0 ZG to K_0 QG given by rationalization is trivial in reduced K-theory or in other words, that any finitely generated projective ZG-module is stably free after rationalization. We show that this statement is false and give a concrete counterexample of a virtually group G for which there exists a finitely generated projective ZG-module P which is not stably free after rationalization, however P+P is. We also show that for groups G satisfying the Farrell-Jones conjecture the image in reduced K-theory is always 2-torsion and we give vanishing conditions in terms of the structure of the finite subgroups of G. We also give a comparison to the strong Bass conjecture and show, using our results, that it follows from the Farrell-Jones conjecture. One of the necessities for constructing an infinite group G such that K_0 ZG to K_0 QG is non-trivial in reduced K-theory is the existence of finite subgroups H which have torsion in the negative K-theory group K_{-1} ZH. This goes back to results of D. Carter, who showed that K_{-1} ZH = Z^r + (Z/2)^s. We give an explicit algorithm for computing s for a finite group using the computer algebra system GAP and compute all such groups with non-trivial s for small orders.In dieser Dissertation untersuchen wir eine Vermutung, welche von W. Lück und H.Reich aufgestellt wurde und besagt, dass für eine Gruppe G, nicht notwendigerweise endlich, die Abbildung K_0 ZG nach K_0 QG, gegeben durch die Rationalisierung, in reduzierter K-Theorie verschwindet. Anders ausgedrückt soll jeder endlich erzeugte projektive ZG-Modul nach Rationalisierung stabil frei sein. Wir zeigen, dass diese Vermutung falsch ist, und konstruieren eine virtuell zyklische Gruppe G mit der Eigenschaft, dass ein ZG-Modul P existiert, welcher nicht stabil frei nach Rationalisierung ist, wobei dies allerdings für P+P gilt. Wir zeigen weiters, dass für Gruppen G, welche die Farrell-Jones Vermutung erfüllen gilt, dass das Bild der Abbildung in reduzierter K-Theorie immer eine 2-Torsionsgruppe ist, und wir geben Bedingungen für das Verschwinden ebenjener Abbildung an, in Bezug auf die Struktur der endlichen Untergruppen von G. Wir vergleichen ebenfalls mit der starken Bass Vermutung und zeigen, durch Verwendung unserer Ergebnisse, dass die Bass Vermutung aus der Farrell-Jones Vermutung folgt. Eine der Notwendigkeiten für das Konstruieren einer unendlichen Gruppe G, für die die Abbildung K_0 ZG nach K_0 QG in reduzierter K-Theorie nicht trivial wirkt, ist die Existenz von endlichen Untergruppen H mit der Eigenschaft, dass die negative K-Theorie-Gruppe K_{-1} ZH nicht-triviale 2-Torsion besitzt. Diese Frage wurde ursprünglich von D.Carter behandelt, welcher zeigte, dass K_{-1} ZH = Z^r + (Z/2)^s. Wir geben einen expliziten Algorithmus an, welcher den Koeffizienten s für endliche Gruppen mit dem Computeralgebrasystem GAP berechnet und berechnen alle Gruppen mit nicht-trivialem s für kleine Ordnungen

Group completion via the action ∞\infty-category

We give a generalization of Quillen's $S^{-1}S$ construction for arbitrary $E_n$-monoids as an $E_{n-1}$-monoidal $\infty$-category and show that its realization models the group completion provided that $n \geq 2$. We will also show how this construction is related to a variety of other constructions of the group completion

Enchondromas and atypical cartilaginous tumors at the proximal humerus treated with intralesional resection and bone cement filling with or without osteosynthesis: retrospective analysis of 42 cases with 6 years mean follow-up

Background: Enchondromas and atypical cartilaginous tumors (ACT) are often located at the proximal humerus. Most lesions can be followed conservatively, but surgical resection may alleviate pain, avoid pathological fractures, and prevent transformation into higher grade chondrosarcomas. Rigorous intralesional resection and filling with polymethylmethacrylate bone cement has been proposed for enchondromas but also for ACT, as an alternative for extralesional resection. We intended to analyze radiological, clinical, and functional outcome of this strategy and compare bone cement without osteosynthesis to bone cement compound osteosynthesis, which has not been analyzed so far. Methods: We retrospectively analyzed 42 consecutive patients (mean follow-up 73 months; range 8–224) after curettage and bone cement filling with or without osteosynthesis. Exclusion criteria were Ollier’s disease and cancellous bone filling. Twenty-five patients only received bone cement. Seventeen patients received additional proximal humerus plate for compound osteosynthesis to increase stability after curettage. Demographics and radiological and clinical outcome were analyzed including surgery time, blood loss, hospitalization, recurrences, and complications. An additional telephone interview at the final follow-up assessed postoperative satisfaction, pain, and function in the quick disabilities of the arm, shoulder, and hand (DASH) score and the Musculoskeletal Tumor Society (MSTS) score. Statistics included the Student T tests, Mann-Whitney U tests, and chi-square tests. Results: No osteosynthesis compared to compound osteosynthesis showed smaller tumors (4.2 (± 1.5) cm versus 6.6 (± 3.0) cm; p = 0.005) and smaller bone cement fillings after curettage (5.7 (± 2.1) cm versus 9.6 (± 3.2) cm; p = 0.0001). A score evaluating preoperative scalloping and soft-tissue extension did not significantly differ (1.9 (± 0.9) versus 2.0 (± 1.0); rating scale 0–4; p = 0.7). Both groups showed high satisfaction (9.2 (± 1.5) versus 9.2 (± 0.9); p = 0.5) and low pain (1.0(±1.7) versus 1.9(±1.8); p = 0.1) in a rating scale from 0 to 10. Clinical and functional outcome was excellent for both groups in the DASH score (6.0 (± 11.8) versus 11.0 (± 13.2); rating scale 0–100; p = 0.2) and the MSTS score (29.0 (± 1.7) versus 28.7 (± 1.1); rating scale 0–30; p = 0.3). One enchondroma recurrence was found in the group without osteosynthesis. Complications (one fracture and one intra-articular screw) were only detected after osteosynthesis. Osteosynthesis had longer surgery time (70 (± 21) min versus 127 (± 22) min; p < 0.0001), more blood loss (220 (± 130) ml versus 460 (± 210) ml; p < 0.0001), and longer stay in the hospital (6 (± 2) days versus 8 (± 2) days; p = 0.004). Conclusions: Intralesional tumor resection was oncologically safe and clinically successful with or without osteosynthesis. Osteosynthesis did not reduce the risk for fracture but was more invasive

The project-oriented organization and its contribution to innovation

This paper presents a new conceptualization of the project-oriented organization. The project-oriented organization is conceptualized as an entrepreneurial, future- and stakeholder-oriented innovating organization, which uses projects as temporary, task-focused organizations, to define, develop, and implement its strategies, to transform its structure, culture and behavior, and to define and develop new products, services, and business models. The concept of the project-oriented organization consists of the three segments (1) values, (2) structures, and (3) people. For each segment three important areas are described, which characterize a project-oriented organization. The model is theoretically based on a wide spectrum of management disciplines: (1) The orientations in the value segment have been developed in entrepreneurship, strategic management and technology and innovation management; (2) The foundations for the design of the socio-technical artefacts in the structure segment of derived from organizational design, planning and controlling, and ICT systems theory; (3) The foundations for the elements of the human side come from organizational behavior, human resource management, and knowledge management theories. Our model shows a clear linkage to these theories, references key articles, and gives special consideration to empirical studies in the realm of projects, programs, project portfolios, and project-based or project-oriented organizations. Thus, our assumption that the elements of our model are supposed to increase project success, innovation success, and business success is based on empirical evidence.acceptedVersion1, forfatterversjo

Quantitative wave-particle duality and non-erasing quantum erasure

The notion of wave-particle duality may be quantified by the inequality V^2+K^2 <=1, relating interference fringe visibility V and path knowledge K. With a single-photon interferometer in which polarization is used to label the paths, we have investigated the relation for various situations, including pure, mixed, and partially-mixed input states. A quantum eraser scheme has been realized that recovers interference fringes even when no which-way information is available to erase.Comment: 6 pages, 4 figures. To appear in Phys. Rev.

Heterozygous DSP in-frame deletion in a poodle with syndromic ichthyosis involving additional hair and tooth abnormalities.

Ichthyoses comprise a large heterogeneous group of skin disorders, characterized by generalized scaly and hyperkeratotic skin. We investigated a miniature poodle with early onset generalized scaling, dry and irregularly thickened skin, paw pad hyperkeratosis and abnormalities in hair and teeth. The clinical signs of ichthyosis were confirmed by histopathological examination, which revealed mild epidermal hyperplasia and lamellar orthokeratotic hyperkeratosis. A hereditary condition was suspected and a genetic investigation was initiated. We sequenced the whole genome of the affected dog and searched for potentially causative variants in functional candidate genes for the observed phenotype. The analysis revealed a heterozygous in-frame deletion in DSP, NC_049256.1:g.8804542_8804544del resulting from a de novo mutation event as evidenced by genotyping leukocyte DNA from both parents. The 3 bp deletion is predicted to remove one aspartic acid without disrupting the open reading frame (XM_038584124.1:c.1821_1823del, XP_038440052.1:p.(Asp608del)). The DSP gene encodes desmoplakin, a desmosomal plaque protein, responsible for cell-cell adhesion to provide resistance to mechanical stress in epidermal and cardiac tissues. We hypothesize that the deletion of one amino acid in the N-terminal globular head domain acts in a dominant negative manner and thus impairs the proper connection with other proteins. Several variants in DSP in humans and cattle have been described to result in different phenotypes associated with hair and skin abnormalities, sometimes in combination with variable cardiac and/or dental manifestations. In conclusion, we characterized a new syndromic ichthyosis phenotype in a dog and identified a de novo 3 bp deletion in the DSP gene as causal variant

Somatic gene therapy for cancer. The utility of transferrinfection in generating ‘tumor vaccines’

The last few years have seen the development of a branch of somatic gene therapy which aims at strengthening the immune surveillance of the body, leading to eradication of disseminated cancer tumor cells and occult micrometastases after surgical removal of the primary tumor. Such a tumor vaccination protocol calls for cultivation of the primary tumor tissue and the insertion of one of three types of genes into the isolated cultured tumor cells followed by irradiation of the transfected or transduced cells to render them incapable of further proliferation. The cells so treated constitute the ‘tumor vaccine’. A review of the literature suggests that for mouse models, in the initial period after inoculation, rejection of the tumor cells is usually effected by non-T-cell immunity, whereas the long-term systemic immune response is based on cytotoxic T-cells. High expression of the gene inserted into the tumor cells may be critical for the success of the vaccination procedure. Examples are given which indicate that transferrinfection, a procedure to introduce genes by adenovirus-augmented receptor-mediated endocytosis, meets some important prerequisites for successful application of this type of gene therapy

Therapy preference of 131 parents confronted with a pediatric femoral fracture.

BACKGROUND: The management of femoral fractures in children between 3 and 5 years of age is still vividly debated. Therefore, we aimed to assess the basic attitude of parents if confronted with a hypothetical femoral fracture of their toddler. MATERIALS AND METHODS: Parents of children aged between 12 and 36 months were asked for their preference after receiving detailed information on conservative and surgical treatment of femoral shaft fractures. Furthermore, we obtained information regarding the parents gender, marital status, medical background, highest level of education and profession in a leading or non-leading position and if any of their children already had undergone any operations. The Freiburg Personality Inventory (FPI-R) questionnaire was used to assess parents personality traits. RESULTS: In total, 131 participants were included in this study. The vast majority (n = 116, 88.5%) preferred surgical treatment. The most frequently mentioned reasons for this decision were lack of acceptance, followed by faster reconvalescence, shorter hospital stay, less deformity or growth disorders and less stress on the child. The only reason stated against surgical treatment was the need of general anesthesia. A significantly higher rate of conservative procedures was noticed in self-employed participants and stress was found to significantly influence the treatment decision of the parents toward conservative treatment. CONCLUSION: The majority of parents confronted with a hypothetical femoral fracture of their child questioned in this study opted for a surgical approach with elastic stable intramedullary nailing (ESIN). This corresponds with trends toward surgery in these cases in major trauma centers in Europe