SELF-DUAL ANYONS IN UNIFORM BACKGROUND FIELDS

We study relativistic self-dual Chern-Simons-Higgs systems in the presence of uniform background fields that explicitly break CTP. A rich, but discrete vacuum structure is found when the gauge symmetry is spontaneously broken, while the symmetric phase can have an infinite vacuum degeneracy at tree level. The latter is due to the proliferation of neutral solitonic states that cost zero energy. Various novel self-dual solitons, such as these, are found in both the symmetric and the asymmetric phases. Also by considering a similar system on a two-sphere and the subsequent large sphere limit, we isolate sensible and finite expressions for the conserved angular and linear momenta, which satisfy anomalous commutation relations. We conclude with a few remarks on unresolved issues.Comment: LaTeX, 20 pages, 4 uuencoded figures included

Vortex Pull by an External Current

In the context of a dynamical Ginzburg-Landau model it is shown numerically that under the influence of a homogeneous external current J the vortex drifts against the current with velocity $V= -J$ in agreement to earlier analytical predictions. In the presence of dissipation the vortex undergoes skew deflection at an angle $90^{\circ} < \delta < 180^{\circ}$ with respect to the external current. It is shown analytically and verified numerically that the angle $\delta$ and the speed of the vortex are linked through a simple mathematical relation.Comment: 19 pages, LATEX, 6 Postscript figures included in separate compressed fil

Finding of widespread viral and bacterial revolution dsDNA translocation motors distinct from rotation motors by channel chirality and size

BACKGROUND: Double-stranded DNA translocation is ubiquitous in living systems. Cell mitosis, bacterial binary fission, DNA replication or repair, homologous recombination, Holliday junction resolution, viral genome packaging and cell entry all involve biomotor-driven dsDNA translocation. Previously, biomotors have been primarily classified into linear and rotational motors. We recently discovered a third class of dsDNA translocation motors in Phi29 utilizing revolution mechanism without rotation. Analogically, the Earth rotates around its own axis every 24 hours, but revolves around the Sun every 365 days. RESULTS: Single-channel DNA translocation conductance assay combined with structure inspections of motor channels on bacteriophages P22, SPP1, HK97, T7, T4, Phi29, and other dsDNA translocation motors such as bacterial FtsK and eukaryotic mimiviruses or vaccinia viruses showed that revolution motor is widespread. The force generation mechanism for revolution motors is elucidated. Revolution motors can be differentiated from rotation motors by their channel size and chirality. Crystal structure inspection revealed that revolution motors commonly exhibit channel diameters larger than 3 nm, while rotation motors that rotate around one of the two separated DNA strands feature a diameter smaller than 2 nm. Phi29 revolution motor translocated double- and tetra-stranded DNA that occupied 32% and 64% of the narrowest channel cross-section, respectively, evidencing that revolution motors exhibit channel diameters significantly wider than the dsDNA. Left-handed oriented channels found in revolution motors drive the right-handed dsDNA via anti-chiral interaction, while right-handed channels observed in rotation motors drive the right-handed dsDNA via parallel threads. Tethering both the motor and the dsDNA distal-end of the revolution motor does not block DNA packaging, indicating that no rotation is required for motors of dsDNA phages, while a small-angle left-handed twist of dsDNA that is aligned with the channel could occur due to the conformational change of the phage motor channels from a left-handed configuration for DNA entry to a right-handed configuration for DNA ejection for host cell infection. CONCLUSIONS: The revolution motor is widespread among biological systems, and can be distinguished from rotation motors by channel size and chirality. The revolution mechanism renders dsDNA void of coiling and torque during translocation of the lengthy helical chromosome, thus resulting in more efficient motor energy conversion

Reciprocal Metabolic Reprogramming through Lactate Shuttle Coordinately Influences Tumor-Stroma Interplay

Cancer-associated fibroblasts (CAF) engage in tumor progression by promoting the ability of cancer cells to undergo epithelial-mesenchymal transition (EMT), and also by enhancing stem cells traits and metastatic dissemination. Here we show that the reciprocal interplay between CAFs and prostate cancer cells goes beyond the engagement of EMT to include mutual metabolic reprogramming. Gene expression analysis of CAFs cultured ex vivo or human prostate fibroblasts obtained from benign prostate hyperplasia revealed that CAFs undergo Warburg metabolism and mitochondrial oxidative stress. This metabolic reprogramming toward a Warburg phenotype occurred as a result of contact with prostate cancer cells. Intercellular contact activated the stromal fibroblasts, triggering increased expression of glucose transporter GLUT1, lactate production, and extrusion of lactate by de novo expressed monocarboxylate transporter-4 (MCT4). Conversely, prostate cancer cells, upon contact with CAFs, were reprogrammed toward aerobic metabolism, with a decrease in GLUT1 expression and an increase in lactate upload via the lactate transporter MCT1. Metabolic reprogramming of both stromal and cancer cells was under strict control of the hypoxia-inducible factor 1 (HIF1), which drove redox-and SIRT3-dependent stabilization of HIF1 in normoxic conditions. Prostate cancer cells gradually became independent of glucose consumption, while developing a dependence on lactate upload to drive anabolic pathways and thereby cell growth. In agreement, pharmacologic inhibition of MCT1-mediated lactate upload dramatically affected prostate cancer cell survival and tumor outgrowth. Hence, cancer cells allocate Warburg metabolism to their corrupted CAFs, exploiting their byproducts to grow in a low glucose environment, symbiotically adapting with stromal cells to glucose availability. Cancer Res; 72(19); 5130-40. (C)2012 AACR

Gene Expression Dynamics During Bone Healing and Osseointegration

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141010/1/jper1007.pd

Promuovere la competenza genitoriale in madri a rischio di breakdown genitoriale

In questo contributo viene presentata una ricerca condotta su un campione di giovani donne italiane che, in adolescenza e nell'infanzia, hanno vissuto un lungo periodo di istituzionalizzazione in collegi tradizionali o in comunità per minori. Sulla base della letteratura internazionale queste donne sono più esposte al breakdown genitoriale in quanto hanno avuto più difficoltà a interiorizzare un legame di attaccamento di tipo sicuro e dispongono di minori capacità nell'esercizio delle funzioni genitoriali. In accordo con gli studi di Rutter e Quinton, 1984, è possibile potenziare il funzionamento genitoriale delle donne istituzionalizzate sulla base di processi protettivi messi in atto dagli ambienti di vita, inclusi quelli istituzionali. La ricerca, utilizzando interviste qualitative e report sulla propria storia di vita, ha confermato i risultati di Rutter e Quinton evidenziando che laddove ci siano state esperienze precoci funzionali all'interiorizzazione di un modello di attaccamento sicuro, nonostante le separazioni successive e periodi più o meno prolungati di istituzionalizzazione, le donne sono più capaci nell'infanzia di affidarsi ad altre persone significative, a pianificare un proprio personale percorso di vita, e successivamente a programmare la generatività e la coniugalità che le preserva dall'incorrere nelle fragilità e nelle incompetenze genitoriali che caratterizzano, al contrario, la storia di donne istituzionalizzate che non hanno usufruito della stessa protezione esercitata dagli ambienti di vita