Reply to the comment on 'Validity of certain soft photon amplitudes'

We respond to the accompanying Comment on our paper, 'Validity of certain soft photon amplitudes'. While we hope the discussion here clarifies the issues, we have found nothing which leads to a change in the original conclusions of our paper.Comment: 6 pages, Latex, uses ReVTeX, now publishe

Using an identity lens : constructive working with children in the criminal justice system

Research has shown that identity, and how you feel about yourself, can be key to moving forward with life and away from crime. Working with the University of Salford, Youth Offending Teams and supported by the Barrow Cadbury Trust, this resource has been developed to promote a constructive, identity-focused approach to ultimately help divert children away from progressing further through the criminal justice system. Using the principles of the Nacro-led Beyond Youth Custody programme, this toolkit outlines how these can be applied to working with children before custody to support them towards positive outcomes and prevent further offending

Comment on ``Validity of certain soft-photon amplitudes''

The criteria suggested by Welsh and Fearing (nucl-th/9606040) to judge the validity of certain soft-photon amplitudes are examined. We comment on aspects of their analysis which lead to incorrect conclusions about published amplitudes and point out important criteria which were omitted from their analysis.Comment: 6 pages plus 1 postscript figure, Revte

Inhibition of cytotoxic T lymphocyte-induced target cell DNA fragmentation, but not lysis, by inhibitors of DNA topoisomerases I and II

Cytotoxic T lymphocytes (CTL) kill their target cells via a contact-dependent mechanism that results in the perturbation of the target cell\u27s plasma membrane and the fragmentation of the target cell\u27s DNA into nucleosomal particles. The membrane disruption is presumed to be due to the action of perforin, while the DNA fragmentation is thought to be by the activation of an endogenous nuclease(s). DNA topoisomerases I and II are nuclear enzymes with inherent endonuclease activities. We have investigated their role in the CTL-induced DNA fragmentation process. We report that in CTL killing assays, the treatment of target cells with topoisomerase I and II inhibitors blocks the CTL-induced DNA fragmentation process, but not the lysis of the target cell

Susceptibility to cytotoxic T lymphocyte-induced apoptosis is a function of the proliferative status of the target

Cytotoxic T lymphocytes (CTL) kill cells by perturbing the target\u27s plasma membrane and by inducing the disintegration of the target cell\u27s DNA into oligonucleosomal fragments, a process characteristic of apoptosis. We show that the DNA fragmentation event is distinct from the membrane lysis event and is dependent on the state of target cell activation or commitment into the mitotic cycle. Quiescent cells were refractory to DNA fragmentation, but not to membrane lysis. Log phase growth, transformation with c-myc, or infection of quiescent G0 targets with herpes simplex virus-1, which induces a competent state for DNA synthesis, all enhanced target cell susceptibility to CTL-induced DNA fragmentation without altering the membrane lysis. These results suggest that G0 cells are resistant to CTL-induced apoptosis, but that entry into G1 or a G1-like state by growth factors, cellular transformation, or DNA virus infection renders them competent to enter the apoptotic pathway(s)

Analysis of complete positivity conditions for quantum qutrit channels

We present an analysis of complete positivity (CP) constraints on qutrit quantum channels that have a form of affine transformations of generalized Bloch vector. For diagonal (damping) channels we derive conditions analogous to the ones that in qubit case produce tetrahedron structure in the channel parameter space.Comment: 12 pages, 8 figures (.eps), minor changes in the text and formula

Androgen action via testicular arteriole smooth muscle cells is important for leydig cell function, vasomotion and testicular fluid dynamics

Regulation of blood flow through the testicular microvasculature by vasomotion is thought to be important for normal testis function as it regulates interstitial fluid (IF) dynamics which is an important intra-testicular transport medium. Androgens control vasomotion, but how they exert these effects remains unclear. One possibility is by signalling via androgen receptors (AR) expressed in testicular arteriole smooth muscle cells. To investigate this and determine the overall importance of this mechanism in testis function, we generated a blood vessel smooth muscle cell-specific AR knockout mouse (SMARKO). Gross reproductive development was normal in SMARKO mice but testis weight was reduced in adulthood compared to control littermates; this reduction was not due to any changes in germ cell volume or to deficits in testosterone, LH or FSH concentrations and did not cause infertility. However, seminiferous tubule lumen volume was reduced in adult SMARKO males while interstitial volume was increased, perhaps indicating altered fluid dynamics; this was associated with compensated Leydig cell failure. Vasomotion was impaired in adult SMARKO males, though overall testis blood flow was normal and there was an increase in the overall blood vessel volume per testis in adult SMARKOs. In conclusion, these results indicate that ablating arteriole smooth muscle AR does not grossly alter spermatogenesis or affect male fertility but does subtly impair Leydig cell function and testicular fluid exchange, possibly by locally regulating microvascular blood flow within the testis

Protective Heterologous Antiviral Immunity and Enhanced Immunopathogenesis Mediated by Memory T Cell Populations

A basic principle of immunology is that prior immunity results in complete protection against a homologous agent. In this study, we show that memory T cells specific to unrelated viruses may alter the host's primary immune response to a second virus. Studies with a panel of heterologous viruses, including lymphocytic choriomeningitis (LCMV), Pichinde (PV), vaccinia (VV), and murine cytomegalo (MCMV) viruses showed that prior immunity with one of these viruses in many cases enhanced clearance of a second unrelated virus early in infection. Such protective immunity was common, but it depended on the virus sequence and was not necessarily reciprocal. Cell transfer studies showed that both CD4 and CD8 T cell populations from LCMV-immune mice were required to transfer protective immunity to naive hosts challenged with PV or VV. In the case of LCMV-immune versus naive mice challenged with VV, there was an enhanced early recruitment of memory phenotype interferon (IFN) γ–secreting CD4+ and CD8+ cells into the peritoneal cavity and increased IFN-γ levels in this initial site of virus replication. Studies with IFN-γ receptor knockout mice confirmed a role for IFN-γ in mediating the protective effect by LCMV-immune T cell populations when mice were challenged with VV but not PV. In some virus sequences memory cell populations, although clearing the challenge virus more rapidly, elicited enhanced IFN-γ–dependent immunopathogenesis in the form of acute fatty necrosis. These results indicate that how a host responds to an infectious agent is a function of its history of previous infections and their influence on the memory T cell pool

Identification of a nearby stellar association in the Hipparcos catalog: implications for recent, local star formation

The TW Hydrae Association (~55 pc from Earth) is the nearest known region of recent star formation. Based primarily on the Hipparcos catalog, we have now identified a group of 9 or 10 co-moving star systems at a common distance (~45 pc) from Earth that appear to comprise another, somewhat older, association (``the Tucanae Association''). Together with ages and motions recently determined for some nearby field stars, the existence of the Tucanae and TW Hydrae Associations suggests that the Sun is now close to a region that was the site of substantial star formation only 10-40 million years ago. The TW Hydrae Association represents a final chapter in the local star formation history.Comment: 5 pages incl figs and table