High power coupled CO2 waveguide laser array

A hollow-bore ridge waveguide technique for phase locking arrays of coupled CO2 rf excited waveguide lasers was demonstrated. Stable phase-locked operation of two- and three-channel arrays has been demonstrated at the 50 W output level. Preliminary experiments with a five-element array generated an output power of 95 W but phase-locked operation was not conclusively demonstrated

Kink-induced symmetry breaking patterns in brane-world SU(3)^3 trinification models

The trinification grand unified theory (GUT) has gauge group SU(3)^3 and a discrete symmetry permuting the SU(3) factors. In common with other GUTs, the attractive nature of the fermionic multiplet assignments is obviated by the complicated multi-parameter Higgs potential apparently needed for phenomenological reasons, and also by vacuum expectation value (VEV) hierarchies within a given multiplet. This motivates the rigorous consideration of Higgs potentials, symmetry breaking patterns and alternative symmetry breaking mechanisms in models with this gauge group. Specifically, we study the recently proposed ``clash of symmetries'' brane-world mechanism to see if it can help with the symmetry breaking conundrum. This requires a detailed analysis of Higgs potential global minima and kink or domain wall solutions interpolating between the disconnected global minima created through spontaneous discrete symmetry breaking. Sufficiently long-lived metastable kinks can also be considered. We develop what we think is an interesting, albeit speculative, brane-world scheme whereby the hierarchical symmetry breaking cascade, trinification to left-right symmetry to the standard model to colour cross electromagnetism, may be induced without an initial hierarchy in vacuum expectation values. Another motivation for this paper is simply to continue the exploration of the rich class of kinks arising in models that are invariant under both discrete and continuous symmetries.Comment: 12 pages, RevTex, references adde

Unification via intermediate symmetry breaking scales with the quartification gauge group

The idea of quark-lepton universality at high energies has been introduced as a natural extension to the standard model. This is achieved by endowing leptons with new degrees of freedom -- leptonic colour, an analogue of the familiar quark colour. Grand and partially unified models which utilise this new gauge symmetry SU(3)_\ell have been proposed in the context of the quartification gauge group SU(3)^4. Phenomenologically successful gauge coupling constant unification without supersymmetry has been demonstrated for cases where the symmetry breaking leaves a residual SU(2)_\ell unbroken. Though attractive, these schemes either incorporate ad hoc discrete symmetries and non-renormalisable mass terms, or achieve only partial unification. We show that grand unified models can be constructed where the quartification group can be broken fully [i.e. no residual SU(2)_\ell] to the standard model gauge group without requiring additional discrete symmetries or higher dimension operators. These models also automatically have suppressed nonzero neutrino masses. We perform a systematic analysis of the renormalisation-group equations for all possible symmetry breaking routes from SU(3)^4 --> SU(3)_q x SU(2)_L x U(1)_Y. This analysis indicates that gauge coupling unification can be achieved for several different symmetry breaking patterns and we outline the requirements that each gives on the unification scale. We also show that the unification scenarios of those models which leave a residual SU(2)_\ell symmetry are not unique. In both symmetry breaking cases, some of the scenarios require new physics at the TeV scale, while others do not allow for new TeV phenomenology in the fermionic sector.Comment: 25 page

A Pilot Study of Mifepristone in Combat-Related PTSD

Background. We obtained pilot data to examine the clinical and neuroendocrine effects of short-term mifepristone treatment in male veterans with PTSD. Methods. Eight male veterans with military-related PTSD completed a randomized, double-blind trial of one week of treatment with mifepristone (600 mg/day) or placebo. The primary clinical outcome measures were improvement in PTSD symptoms and dichotomously defined clinical responder status as measured by the CAPS at one-month follow-up. Additional outcome measures included self-reported measures of PTSD symptom severity, CAPS-2 symptom subscale scores, and morning plasma cortisol and ACTH levels. Results. Mifepristone was associated with significant improvements in total CAPS-2 score. At one-month follow-up, all four veterans in the mifepristone group and one of four veterans in the placebo group achieved clinical response; three of four veterans in the mifepristone group and one of four veterans in the mifepristone group remitted. Mifepristone treatment was associated with acute increases in cortisol and ACTH levels and decreases in cytosolic glucocorticoid receptor number in lymphocytes. Conclusions. Further controlled trials of the effects of mifepristone and their durability are indicated in PTSD. If effective, a short-term pharmacological treatment in PTSD could have myriad uses

Early ageing after cytotoxic treatment for testicular cancer and cellular senescence: Time to act

Treatment of testicular cancer (TC) has an exceptionally high success rate compared to other cancer types; even in case of metastasized disease, 80-90 % of TC patients can be cured. Consequently, attention has been drawn to a potential downside of this treatment success: late adverse treatment effects such as the accelerated development of otherwise age-associated features like cardiovascular disease and second malignancies. Underlying mechanisms are poorly understood. Emerging data suggest that cytotoxic treatment induces cellular senescence, resulting in secretion of inflammatory factors contributing to this early ageing phenotype. Molecular and cellular characterization of this early ageing will enhance understanding the pathogenesis of TC treatment-induced morbidity and contribute to better recognition and prevention of late effects. In this review, we describe clinical manifestations of the early ageing phenotype among TC survivors, and subsequently focus on potential underlying mechanisms. We discuss the clinical implications and describe perspectives for future research and intervention strategies

Spaces of Memory

In the last decade, museums, memorials and monuments have become the battlefield for competing and conflicting visions of the past and the hegemonic or counter memories of the so-called “difficult heritage” or “traumatic heritage”. Far from being mere spaces of musealization that freeze and fix dominant narratives of the past, spaces of memory are increasingly turning into sites of negotiations and reconfigurations of meaning in which social and political identities are debated, strengthened, or weakened in reference to the traumatic experiences of the past which they “represent”. Yet, what does it mean to spatially represent a (traumatic) memory, and what is a space of memory? In expanding and, simultaneously, problematizing Pierre Nora’s (Nora 1996) category of lieu de mémoire, the way we think of spaces of memory aims at an in-depth examination of the peculiar yet specific ways of re-thinking the nexus between space and memory: how do we elaborate, activate, and make visible spaces for memory? This question points to the dynamic construction that underlines the production and connection of spatiality and memory, as well as to the coexistence of a plurality of meanings and experiences that characterize spaces of memory

Assessment of left atrial volume before and after pulmonary thromboendarterectomy in chronic thromboembolic pulmonary hypertension.

BackgroundImpaired left ventricular diastolic filling is common in chronic thromboembolic pulmonary hypertension (CTEPH), and recent studies support left ventricular underfilling as a cause. To investigate this further, we assessed left atrial volume index (LAVI) in patients with CTEPH before and after pulmonary thromboendarterectomy (PTE).MethodsForty-eight consecutive CTEPH patients had pre- & post-PTE echocardiograms and right heart catheterizations. Parameters included mean pulmonary artery pressure (mPAP), pulmonary vascular resistance (PVR), cardiac index, LAVI, & mitral E/A ratio. Echocardiograms were performed 6 ± 3 days pre-PTE and 10 ± 4 days post-PTE. Regression analyses compared pre- and post-PTE LAVI with other parameters.ResultsPre-op LAVI (mean 19.0 ± 7 mL/m2) correlated significantly with pre-op PVR (R = -0.45, p = 0.001), mPAP (R = -0.28, p = 0.05) and cardiac index (R = 0.38, p = 0.006). Post-PTE, LAVI increased by 18% to 22.4 ± 7 mL/m2 (p = 0.003). This change correlated with change in PVR (765 to 311 dyne-s/cm5, p = 0.01), cardiac index (2.6 to 3.2 L/min/m2, p = 0.02), and E/A (.95 to 1.44, p = 0.002).ConclusionIn CTEPH, smaller LAVI is associated with lower cardiac output, higher mPAP, and higher PVR. LAVI increases by ~20% after PTE, and this change correlates with changes in PVR and mitral E/A. The rapid increase in LAVI supports the concept that left ventricular diastolic impairment and low E/A pre-PTE are due to left heart underfilling rather than inherent left ventricular diastolic dysfunction

È VIVO: Virtual eruptions at Vesuvius; A multimedia tool to illustrate numerical modeling to a general public

Dissemination of scientific results to the general public has become increasingly important in our society. When science deals with natural hazards, public outreach is even more important: on the one hand, it contributes to hazard perception and it is a necessary step toward preparedness and risk mitigation; on the other hand, it contributes to establish a positive link of mutual confidence between scientific community and the population living at risk. The existence of such a link plays a relevant role in hazard communication, which in turn is essential to mitigate the risk. In this work, we present a tool that we have developed to illustrate our scientific results on pyroclastic flow propagation at Vesuvius. This tool, a CD-ROM that we developed joining scientific data with appropriate knowledge in communication sciences is meant to be a first prototype that will be used to test the validity of this approach to public outreach. The multimedia guide contains figures, images of real volcanoes and computer animations obtained through numerical modeling of pyroclastic density currents. Explanatory text, kept as short and simple as possible, illustrates both the process and the methodology applied to study this very dangerous natural phenomenon. In this first version, the CD-ROM will be distributed among selected categories of end-users together with a short questionnaire that we have drawn to test its readability. Future releases will include feedback from the users, further advancement of scientific results as well as a higher degree of interactivity