Cryptographic Protocols Based on Nielsen Transformations

We introduce in this paper cryptographic protocols which use combinatorial group theory. Based on a combinatorial distribution of shares we present secret sharing schemes and cryptosystems using Nielsen transformations. Nielsen transformations are a linear technique to study free groups and general infinite groups. In addition the group of all automorphisms of a free group F, denoted by ( )Aut F, is generated by a regular Nielsen transformation between two basis of F, and each regular Nielsen transformation between two bases of F defines an automorphism of F

Secure Passwords Using Combinatorial Group Theory

Password security is a crucial component of modern internet security. In this paper, we present a provably secure method for password verification using combinatorial group theory. This method relies on the group randomizer system, a subset of the MAGNUS computer algebra system and corrects most of the present problems with challenge response systems, the most common types of password verification. Theoretical security of the considered method depends on several results in asymptotic group theory. We mention further that this method has applications for many other password situations including container security

Hematopoietic progenitor cells and interleukin-stimulated endothelium: expansion and differentiation of myeloid precursors

<p>Abstract</p> <p>Background</p> <p>Cytokine-stimulated endothelial cells (EC) propagate hematopoietic progenitor cell (HPC) expansion. However, the effects on the functional capacities of cultured progenitors have not been evaluated. HPC were assessed by flow cytometry, colony and cobblestone assays and long-term cultures (LTC) after culturing in the supernatant of EC stimulated by IL-1β, IL-3 or IL-6.</p> <p>Results</p> <p>EC incubation with IL-6 did not improve cell expansion in comparison to non-stimulated EC supernatant, while the HPCs' phenotype and functional capacities were retained. In contrast, IL-1β and IL-3 stimulation resulted in a 10- and 100-fold increase in cell numbers with more than 90% of these cells being CD33(+). Plating efficiencies and LTC initiating cells were greatest in IL-6 supernatants, whereas the highest numbers of burst-forming units were observed using IL-3. IL-1β supernatants diminished the number of 5-week cobblestone-areas, whereas the number of 2-week cobblestone areas remained equal to freshly isolated HPC. Fewer 2-week cobblestones and greater amounts of 5-week cobblestones were observed with IL-6 and IL-3. Expanded progenitors from all interleukin conditions were further matured into functional granulocytes.</p> <p>Conclusion</p> <p>IL-1β and IL-3 stimulated endothelium induces proliferation and differentiation of myeloid precursors, while IL-6 treatment induced a benefit of HPC survival.</p

ЕВОЛЮЦІЯ МЕТОДОЛОГІЧНИХ ЗАСАД ДОСЛІДЖЕННЯ НОВОЇ ЕКОНОМІКИ: ВІД СТОХАСТИЧНОЇ ПЕРЦЕПЦІЇ ДО АЛГОРИТМІЗАЦІЇ ПІЗНАННЯ

Структуровані основні методологічні підходи до організації фундаментальних досліджень динаміки нової економіки; парадигма глобального еволюці-онізму визначена як найбільш адекватної та гносеологічно перспективної методологічної основи таких досліджень. Сучасна версія глобального еволюціонізму розглядається як результат інтеграції системного підходу, синергетики і еволюціонізму.; The basic methodological approaches to organization of fundamental researches of dynamics of new economy are considered and structured; the paradigm of global evolutionism is determined as the most adequate and agnostically perspective methodological basis of similar researches. The modern version of global evolutionism is examined as a result of integration of system approach, synergetic and evolutionism

Neurofascin as a novel target for autoantibody-mediated axonal injury

Axonal injury is considered the major cause of disability in patients with multiple sclerosis (MS), but the underlying effector mechanisms are poorly understood. Starting with a proteomics-based approach, we identified neurofascin-specific autoantibodies in patients with MS. These autoantibodies recognize the native form of the extracellular domains of both neurofascin 186 (NF186), a neuronal protein concentrated in myelinated fibers at nodes of Ranvier, and NF155, the oligodendrocyte-specific isoform of neurofascin. Our in vitro studies with hippocampal slice cultures indicate that neurofascin antibodies inhibit axonal conduction in a complement-dependent manner. To evaluate whether circulating antineurofascin antibodies mediate a pathogenic effect in vivo, we cotransferred these antibodies with myelin oligodendrocyte glycoprotein–specific encephalitogenic T cells to mimic the inflammatory pathology of MS and breach the blood–brain barrier. In this animal model, antibodies to neurofascin selectively targeted nodes of Ranvier, resulting in deposition of complement, axonal injury, and disease exacerbation. Collectively, these results identify a novel mechanism of immune-mediated axonal injury that can contribute to axonal pathology in MS

The dendritic cell

In den hier zusammengefassten Publikationen werden Verfahren zur Herstellung dendritischer Zellen mit dem Ziel einer Verwendung als Krebsvakzin vorgestellt. Als Quelle dienten Monozyten des peripheren Bluts, CD34(+) hämatopoetische Vorläuferzellen sowie leukämische Blasten. DZ aller drei Typen waren von vergleichbarer Natur hinsichtlich der Morphologie, des Immunphänotyps und der allostimulatorischen Kapazität. Signifikante Unterschiede fanden sich jedoch in ihrer Fähigkeit, entlang eines Chemokingradienten zu wandern, die bei den leukämischen DZ nicht mehr vorhanden war. Demnach müssten DZ unterschiedlicher Herkunft verschieden appliziert werden. Monozytären DZ und DZ aus hämatopoetischen Vorläuferzellen können intravenös oder intratumorös angewendet werden, während leukämische DZ intralymphatisch appliziert werden sollten.The publications summarized in here introduce various procedures for the manufacturing of dendritic cell (DC) vaccines as anti-cancer agents. DC were generated from peripheral blood monocytes, CD34(+) hematopoietic progenitor cells an leukemic blasts. DC from all three sources were of comparable morphologies, immune phenotypes and allostimulatory capacities. Their migratory capacities in response to chemotactic gradients, however, varied significantly. Leukemic DC, in particular, could not migrate at all. Therefore, DC of different origin need to be applied differently in vivo. Monocytic DC and DC from hematopoietic progenitors can be administered intravenuously or intalesionally, whereas leukemic DC need to be injected directly into the lymphatic system

"für mich sind medien ein WERKzeug". Zum Sprechen über digitale Medien im Anspruch von Schulentwicklung

Ausgehend von der Frage, wie es im Kontext von Prozessen der Digitalisierung zu einem Wandel von Schule und Unterricht kommt, richtet sich der Fokus dieses Beitrages auf das Sprechen von Lehrer*innen über digitale Medien. Zunächst thematisieren die Autorinnen gängige Relationierungen von Digitalisierung, (digitalen) Medien und Pädagogik, um knapp den diskursiven Rahmen zu skizzieren, vor dessen Hintergrund die Lehrer*innen potentiell sprechen, einander adressieren und dessen hegemoniale Ordnung sie zitieren bzw. iterieren. Daran anschließend konkretisieren sie ihre Perspektive auf das Sprechen über Schule und digitale Medien als Praxis sozialer Ordnungsbildung, die in vielerlei Hinsicht durch ein näher zu bestimmendes Transformationspotential gekennzeichnet ist. Für die Spezifizierung dieses Transformationspotentials greifen sie zunächst auf das kulturtheoretische Konzept der Übersetzung zurück, bevor sie sich nachfolgend einer Analyse des Adressierungsgeschehens in schulischen Teamgesprächen zuwenden, in denen im Anspruch von Schulentwicklung über digitale Medien gesprochen wird. In der Diskussion der Analyseergebnisse erläutern die Verfasserinnen, inwiefern die sich im Sprechen über digitale Medien zeigenden Irritationen pädagogischer Ordnungsbildungsprozesse als Trans-Formationen gelesen werden können. (DIPF/Orig.

Comparison of platelet function tests for the in vitro quality assessment of platelet concentrates produced under real-life conditions

Platelet quality in different platelet concentrates (PCs) has been the subject of several studies. Nonetheless, there is a lack of robust data on the correlation and agreement among platelet function tests as a prerequisite for the association of PC functionality in vitro with platelet function in vivo post PC transfusion. The purpose of our study was to correlate a larger panel of platelet function assays in PCs and to assess whether the methods agree sufficiently and can be used interchangeably. Twelve apheresis platelet concentrates in plasma (APC), 16 pooled platelet concentrates in plasma (PPC), and 12 PPC in T-sol (PPCA) were examined on days 1 and 4 after production. PCs were tested for platelet count, light transmission aggregation (LTA) induced by ADP, collagen, or TRAP; platelet ATP release induced by collagen; and spontaneous and ADP and TRAP-induced increase in CD62P and PAC1 expression measured by flow cytometry. All tests were performed in undiluted platelet-rich plasma, recalcified and mixed with an inhibitor of factor Xa and thrombin. Most platelet function parameters correlated significantly with each other, but agreement among methods was insufficient. A proper inverse correlation was observed between ADP-induced LTA and spontaneous platelet activation assessed by CD62P expression (r = −0.61, p < 0.0001). Spontaneous CD62P correlated also significantly with spontaneous PAC1 (r = 0.69, p < 0.0001) and inversely with TRAP-induced CD62P expression (r = −0.86, p < 0.0001). We found significant correlations among all flow cytometric assays measuring platelet CD62P and PAC1 expression induced by ADP or TRAP. Subsequent Bland Altman analysis revealed insufficient agreement between methods. With one exception (collagen-induced LTA compared with TRAP-induced LTA, percentage error = 16%) the limits of agreement expressed as percentage error exceeded the chosen acceptable difference of 30%. In APC, platelet count was 41% and 44% higher, respectively, than in PPC and PPCA (p < 0.0001). Spontaneous CD62P and PAC1 expression were significantly greater, and ADP-induced aggregation and agonist-induced increase in CD62P and PAC1 were significantly lower in PPCA compared to APC and PPC on day 4 of storage. ADP and TRAP-induced CD62P and PAC1 activatability fell significantly during storage between day 1 and day 4 in APC and PPCA, but not in PPC. In conclusion, different platelet function tests capture different aspects of platelet function and do not correlate and agree sufficiently to be used interchangeably