Transport Properties of d-Wave Superconductors in the Vortex State

We calculate the magnetic field dependence of quasiparticle transport properties in the vortex state of a d-wave superconductor arising solely from the quasiparticle's Doppler shift in the superflow field surrounding the vortex. Qualitative features agree well with experiments on cuprate and heavy fermion superconductors at low fields and temperatures. We derive scaling relations in the variable $T/H^{1/2}$ valid at sufficiently low temperatures $T$ and fields $H$, but show that these relations depend on the scattering phase shift, and are in general fulfilled only approximately even in the clean limit, due to the energy dependence of the quasiparticle relaxation time.Comment: 5 pages, 2 Postscript figure

RNA with chemotherapeutic base analogues as a dual-functional anti-cancer drug

Nanoparticles of different sizes formulated with unmodified RNA and Protamine differentially engage Toll-like Receptors (TLRs) and activate innate immune responses in vitro. Here, we report that similar differential immunostimulation that depends on the nanoparticle sizes is induced in vivo in wild type as well as in humanized mice. In addition, we found that the schedule of injections strongly affects the magnitude of the immune response. Immunostimulating 130 nm nanoparticles composed of RNA and Protamine can promote lung metastasis clearance but provides no control of subcutaneous tumors in a CT26 tumor model. We further enhanced the therapeutic capacity of Protamine-RNA nanoparticles by incorporating chemotherapeutic base analogues in the RNA; we coined these immunochemotherapeutic RNAs (icRNAs). Protamine-icRNA nanoparticles were successful at controlling established subcutaneous CT26 and B16 tumors as well as orthotopic glioblastoma. These data indicate that icRNAs are promising cancer therapies, which warrants their further validation for use in the clinic. Keywords: 5FU; Chemotherapy; RNA; immunotherapy; toll like receptor; type I interferon

Long-term leukocyte reconstitution in NSG mice transplanted with human cord blood hematopoietic stem and progenitor cells

Abstract Background Humanized mice (hu mice) are based on the transplantation of hematopoietic stem and progenitor cells into immunodeficient mice and have become important pre-clinical models for biomedical research. However, data about their hematopoiesis over time are scarce. We therefore characterized leukocyte reconstitution in NSG mice, which were sublethally irradiated and transplanted with human cord blood-derived CD34+ cells at newborn age, longitudinally in peripheral blood and, for more detailed analyses, cross-sectionally in peripheral blood, spleen and bone marrow at different time points. Results Human cell chimerism and absolute human cell count decreased between week 16 and 24 in the peripheral blood of hu mice, but were stable thereafter as assessed up to 32 weeks. Human cell chimerism in spleen and bone marrow was maintained over time. Notably, human cell chimerism in peripheral blood and spleen as well as bone marrow positively correlated with each other. Percentage of B cells decreased between week 16 and 24, whereas percentage of T cells increased; subsequently, they levelled off with T cells clearly predominating at week 32. Natural killer cells, monocytes and plasmacytoid dendritic cells (DCs) as well as CD1c + and CD141+ myeloid DCs were all present in hu mice. Proliferative responses of splenic T cells to stimulation were preserved over time. Importantly, the percentage of more primitive hematopoietic stem cells (HSCs) in bone marrow was maintained over time. Conclusions Overall, leukocyte reconstitution was maintained up to 32 weeks post-transplantation in our hu NSG model, possibly explained by the maintenance of HSCs in the bone marrow. Notably, we observed great variation in multi-lineage hematopoietic reconstitution in hu mice that needs to be taken into account for the experimental design with hu mice

Self-organisation in LTE networks : an investigation

Mobile telecommunications networks based on Long Term Evolution (LTE) technology promise faster throughput to their users. LTE networks are however susceptible to a phenomenon known as inter-cell interference which can greatly reduce the throughput of the network causing unacceptable degradation of performance for cell edge users. A number of approaches to mitigating or minimising inter-cell interference have been presented in the literature such as randomisation, cancellation and coordination. The possibility of coordination between network nodes in an LTE network is made possible through the introduction of the X2 network link. This thesis explores approaches to reducing the effect of inter-cell interference on the throughput of LTE networks by using the X2 link to coordinate the scheduling of radio resources. Three approaches to the reduction of inter-cell interference were developed. Localised organisation is a centralised scheme in which a scheduler is optimised by a Genetic Algorithm (GA) to reduce interference. Networked organisation makes use of the X2 communications link to enable the network nodes to exchange scheduling information in a way that lowers the level of interference across the whole network. Finally a more distributed and de-centralised approach is taken in which each of the network nodes optimises its own scheduling in coordination with its neighbours. An LTE network simulator was built to allow for experimental comparison between these techniques and a number of existing approaches and to serve as a test bed for future algorithm development. These approaches were found to significantly improve the throughput of the cell edge users who were most affected by intereference. In particular the networked aspect of these approaches yielded the best initial results showing clear improvement over the existing state of the art. The distributed approach shows significant promise given further development.EPSR

Altering an Artificial Gagpolnef Polyprotein and Mode of ENV Co-Administration Affects the Immunogenicity of a Clade C HIV DNA Vaccine

HIV-1 candidate vaccines expressing an artificial polyprotein comprising Gag, Pol and Nef (GPN) and a secreted envelope protein (Env) were shown in recent Phase I/II clinical trials to induce high levels of polyfunctional T cell responses; however, Env-specific responses clearly exceeded those against Gag. Here, we assess the impact of the GPN immunogen design and variations in the formulation and vaccination regimen of a combined GPN/Env DNA vaccine on the T cell responses against the various HIV proteins. Subtle modifications were introduced into the GPN gene to increase Gag expression, modify the expression ratio of Gag to PolNef and support budding of virus-like particles. I.m. administration of the various DNA constructs into BALB/c mice resulted in an up to 10-fold increase in Gag- and Pol-specific IFNγ+ CD8+ T cells compared to GPN. Co-administering Env with Gag or GPN derivatives largely abrogated Gag-specific responses. Alterations in the molar ratio of the DNA vaccines and spatially or temporally separated administration induced more balanced T cell responses. Whereas forced co-expression of Gag and Env from one plasmid induced predominantly Env-specific T cells responses, deletion of the only H-2d T cell epitope in Env allowed increased levels of Gag-specific T cells, suggesting competition at an epitope level. Our data demonstrate that the biochemical properties of an artificial polyprotein clearly influence the levels of antigen-specific T cells, and variations in formulation and schedule can overcome competition for the induction of these responses. These results are guiding the design of ongoing pre-clinical and clinical trials

Modulation der Immunogenität einer auf Gag, Pol und Nef basierenden HIV-1-Vakzine

Als Ausgangspunkt dieser Arbeit dienten die klinischen Studien EuroVacc01 und 02, bei denen gezeigt werden konnte, dass das getestete 97CN54 GagPolNef (GPN) Konstrukt in Kombination mit 97CN54 Env gp120 zwar gute Env-spezifische, aber nur in geringerem Umfang Gag-, Pol- und Nef-spezifische polyfunktionelle Antworten auf T-Zellebene induzierte. So waren die Studien hinsichtlich der Induktion Env-spezifischer Immunantworten ein Erfolg, hinsichtlich GPN wäre ein balancierteres Verhältnis der T-Zellantworten wünschenswerter gewesen. In dieser Arbeit sollte das GPN Konstrukt weiterentwickelt werden, um vor allem die in den Studien beobachteten schwachen Gag-spezifischen T-Zellantworten zu verstärken, ohne die Env-spezifischen Immunantworten zu beeinträchtigen. Die Modifikationen des Ausgangskonstrukts sollten i) die Wiederherstellung des Myristylierungssignals, ii) des viralen, ribosomalen Leserastersprungs und iii) der Aktivität der viralen Protease umfassen, um Partikelfreisetzung und Prozessierung des GPN-Polyproteins zu ermöglichen. Durch die verstärkte Freisetzung von GPN Partikeln sollte vor allem über cross-presentation die Immunogenität gesteigert werden. Während der Herstellung des modifizierten Konstrukts wurde festgestellt, dass das 97CN54 Pr55gag nicht in der Lage war, virus-ähnliche Partikel (VLP) zu bilden. Nach einem Aminosäurensequenzabgleich mit dem Gag des 97CN001 Virus, welches derselben Patientenprobe entstammt wie 97CN54, wurden 7 Aminosäuresubstitionen identifiziert, welche die Partikelbildung beeinträchtigen könnten. Aus diesem Grunde wurde das 97CN54 Gag im Konstrukt durch 97CN001 Gag ersetzt. Im Anschluss konnten die geplanten Konstrukte generiert werden, welche die gewünschten Eigenschaften aufwiesen. In Immunisierungsstudien mit Balb/C Mäusen wurde dann gezeigt, dass durch die Resubstitution des Myristylierungssignals am N-Terminus des Polyproteins und das Einfügen eines ribosomalen Leserastersprungs das GPN in seinen immunologischen Eigenschaften deutlich verbessert ist. Aufgrund einer nichtbeschriebene Punktmutation in der viralen Protease, welche deren Funktion inhibierte, verzögerte sich die Herstellung des Konstrukts mit aktiver viraler Protease und konnte nicht mehr in Immunisierungsstudien getestet werden. Ein weiterer wesentlicher Aspekt dieser Arbeit war die Generierung eines kodonoptimiertes 97CN001 Gag und eines 97CN54 PolNef Konstrukts, mit denen sich bei Immunisierungen verschiedenste Kombinationen, wie unterschiedliche Mischungsverhältnisse oder räumlich bzw. zeitlich getrennte Vakzinierungen, analysieren ließen. Zudem konnten nun 97CN001 Gag basierte VLP zu produziert werden, was mit dem ursprünglichen 97CN54 Gag aufgrund der ungenügenden Partikelbildung nicht möglich war. Dies eröffnet neue Optionen für künftige Immunisierungsstudien. Desweiteren konnten neue Impfstrategien für eine Koimmunisierung von 97CN001 Gag bzw. GPN mit 97CN54 Env gp120 DNA getestet werden, um eine beobachtete immunologische Konkurrenz von Gag- und Env-spezifischen CD8+ T-Zellantworten zu vermeiden. So ließen sich bei einer räumlichen Trennung der Env gp120 von der Gag/Pol Vakzinierung bzw. einer Reduktion der applizierten Menge an Env gp120 DNA deutlich bessere Gag-spezifische CD8+ T-Zellantworten als bei einer äquimolaren Koapplikation induzieren. Hinsichtlich der Entwicklung einer CD40L Variante als molekulares Adjuvans wurde erfolgreich eine membranständige Version des oligomeren MegaCD40L generiert. Diese Variante (MCD40L-MB) konnte auf der Oberfläche von VLP verankert werden und erwies sich im Aktivierungs- und Proliferationsexperiment mit murinen B-Zellen als fast ebenso so stimulatorisch wie wildtyp CD40L (wtCD40L) bzw. teilweise stimulatorischer als der lösliche, rekombinant hergestellte MCD40L. In einer ersten Immunisierungsstudie mit 97CN54 Env gp145 pseudotypisierten VLP wurden multivalente Immunantworten gegen Gag und Env untersucht. Jedoch konnten hier weder seitens wtCD40L noch seitens des MCD40L-MB deutliche Adjuvanseigenschaften bezüglich der Induktion spezifischer zellulärer und humoraler Antworten gemessen werden. Dies konnte auf die zu geringen Mengen an CD40L in den VLP Präparationen zurückgeführt werden. In einer auf 97CN001Gag/97CN54 Env gp145 Plasmid-DNA basierten Immunisierungstudie konnte ein positiver Einfluss des MCD40L auf die Induktion von Env-spezifischen CD8+ T-Zell und humoralen Immunantworten gezeigt werden. So ließ sich beobachten, dass eine Adjuvierung mit MCD40L zwar die Env-spezifischen Antworten verstärkt, die Gag-spezifischen CD8+ T-Zell Antworten hingegen abgeschwächt wurden. Dennoch konnten Strategien über die Dosierung des MCD40L erschlossen werden, um optimale Gag- und Env-spezifische Immunantworten induzieren zu können. In dieser Arbeit konnten also nicht nur verbesserte Immunogene und mögliche Kandidaten für molekulare Adjuvantien entwickelt werden, sondern auch verbesserte Strategien, diese im Rahmen von Immunisierungen applizieren zu können

The Humanized Mouse Model: What Added Value Does It Offer for HIV Research?

In the early 2000s, novel humanized mouse models based on the transplantation of human hematopoietic stem and progenitor cells (HSPCs) into immunocompromised mice were introduced (hu mice). The human HSPCs gave rise to a lymphoid system of human origin. The HIV research community has greatly benefitted from these hu mice. Since human immunodeficiency virus (HIV) type 1 infection results in a high-titer disseminated HIV infection, hu mice have been of great value for all types of HIV research from pathogenesis to novel therapies. Since the first description of this new generation of hu mice, great efforts have been expended to improve humanization by creating other immunodeficient mouse models or supplementing mice with human transgenes to improve human engraftment. Many labs have their own customized hu mouse models, making comparisons quite difficult. Here, we discuss the different hu mouse models in the context of specific research questions in order to define which characteristics should be considered when determining which hu mouse model is appropriate for the question posed. We strongly believe that researchers must first define their research question and then determine whether a hu mouse model exists, allowing the research question to be studied

ESTIMACIÓN DEL VALOR EN RIESGO DE UN PORTAFOLIO: UN COMPARATIVO ENTRE LOS METODOS DELTA-NORMAL Y MONTECARLO IMPLEMENTANDO UNA ESTRATEGIA DE COBERTURA

El presente trabajo se conforma de 4 capítulos y un apartado de conclusiones, donde se le dará el veredicto final a nuestra hipótesis formulada al inicio de este trabajo. En nuestro primer capítulo abordaremos toda la información referente al sistema financiero mexicano ya que es de suma importancia conocer su estructura, funcionamiento y el gran papel que juega respecto a la regulación en los mercados financieros. En mencionado capitulo abordaremos la descripción de los organismos que lo conforman, sus funciones y a su vez también sus limitantes. De igual manera contemplaremos los mercados financieros, su clasificación y poniendo mayor atención en el mercado de capitales, con todo lo que este este mercado necesita y requiere para su buen funcionamiento. En nuestro segundo capítulo abordaremos el concepto de riesgo, así como definiremos el riesgo financiero y sus clasificaciones. Trataremos algunos otros conceptos como rendimiento de los activos ya que es primario para un inversionista. Así mismo Dentro de este capítulo nos adentraremos en lo que es un portafolio de inversiones y como es que se conforma. Por ultimo en este capítulo trataremos el CAPM, puesto lo ocuparemos para la creación de nuestro portafolio y la teoría de markowitz. Se hablara del Valor en riesgo como tal “VaR” y sus metodologías para su estimación Para el tercer capítulo abordaremos nuestra investigación central que se concentra en la realización de la estimación del VaR por el método Montecarlo y el método delta normal contemplando la elección del portafolio y su diversificación. Ya para el cuarto capítulo y ultimo de esta investigación se aborda lo que es la estrategia de cobertura por medio de contratos futuros. Por ultimo tendremos nuestras conclusiones en donde se compararan los resultados de la estimación del valor en riesgo para nuestros 2 métodos y cuál es el resultado que se obtuvo con la aplicación de la estrategia de cobertura

Expression of Gag and Env in co-transfected 293T cells and the effect of administrating Gag-2a-Env on Gag- and Env-specific CD8⁺ T cell responses.

<p>(A) 293T cells were transiently transfected with 3 µg of the indicated plasmid DNA constructs. Following 48 h incubation, TCA-precipitated supernatants and cell lysates were separated by SDS-PAGE and analyzed by immunoblotting using p24-specific (Gag) mouse mAb (CB-4/1), and gp120-specific mouse mAb (MH23), as indicated. Molecular weight markers and positions of the detected proteins are indicated. mock: non-transfected 293T cells. (B) 293T cells were transiently transfected with equimolar amounts of the indicated plasmid DNA constructs. At 48 h post transfection, cells were permeabilized, stained with anti-p24-PE and/or anti-gp120-ALEXA 488 and analyzed by flow cytometry. (C) BALB/c mice (n = 6 per group) were inoculated i.m. with (i) an equimolar mixture of ^MGag and gp120 in both legs, (ii) ^MGag in the left, and gp120 in the right leg, or (iii) ^MGag-2a-gp120. After 12 days, spleen cells were isolated and tested for specific cellular immune responses by measuring IFNγ production after stimulation with Gag (black) and Env (hatched) specific peptides as above. IFNγ production was determined using FACS analysis after intracellular staining of IFNγ. Cell culture medium served as negative control. Data shown are representative of two experiments.</p

Protein expression from the modified constructs.

<p>293T cells were transiently transfected with the indicated plasmid DNA constructs using jetPEI. Cells and supernatants were harvested after 48 h. Cell lysates, and supernatants processed by TCA/acetone precipitation, were separated by 8.0% SDS-PAGE and analyzed by immunoblotting using p24-specific (Gag) mouse mAb (CB-4/1), HIV-1 RT (Pol)-specific mouse mAb (5B2B2), and gp120-specific mouse mAb (MH23) to specifically detect the corresponding recombinant polypeptides. Molecular weight markers and positions of the specifically detected proteins are indicated. mock: non-transfected 293T cells.</p