Low-Energy Constraints on New Physics Revisited

It is possible to place constraints on non-Standard-Model gauge-boson self-couplings and other new physics by studying their one-loop contributions to precisely measured observables. We extend previous analyses which constrain such nonstandard couplings, and we present the results in a compact and transparent form. Particular attention is given to comparing results for the light-Higgs scenario, where nonstandard effects are parameterized by an effective Lagrangian with a linear realization of the electroweak symmetry breaking sector, and the heavy-Higgs/strongly interacting scenario, described by the electroweak chiral Lagrangian. The constraints on nonstandard gauge-boson self-couplings which are obtained from a global analysis of low-energy data and LEP/SLC measurements on the Z pole are updated and improved from previous studies. Replaced version: tables and figures of Section VIb recalculated. There were roundoff problems, especially in Fig. 8. Text unchanged.Comment: \documentstyle[preprint,aps,floats,psfig]{revtex}, 10 figures, postscript version available from ftp://ftp.kek.jp/kek/preprints/TH/TH-51

Exploring alternative symmetry breaking mechanisms at the LHC with 7, 8 and 10 TeV total energy

In view of the annnouncement that in 2012 the LHC will run at 8 TeV, we study the possibility of detecting signals of alternative mechanisms of ElectroWeak Symmetry Breaking, described phenomenologically by unitarized models, at energies lower than 14 TeV. A complete calculation with six fermions in the final state is performed using the PHANTOM event generator. Our results indicate that at 8 TeV some of the scenarios with TeV scale resonances are likely to be identified while models with no resonances or with very heavy ones will be inaccessible, unless the available luminosity will be much higher than expected

CD28 between tolerance and autoimmunity: The side effects of animal models [version 1; referees: 2 approved]

Regulation of immune responses is critical for ensuring pathogen clearance and for preventing reaction against self-antigens. Failure or breakdown of immunological tolerance results in autoimmunity. CD28 is an important co-stimulatory receptor expressed on T cells that, upon specific ligand binding, delivers signals essential for full T-cell activation and for the development and homeostasis of suppressive regulatory T cells. Many in vivo mouse models have been used for understanding the role of CD28 in the maintenance of immune homeostasis, thus leading to the development of CD28 signaling modulators that have been approved for the treatment of some autoimmune diseases. Despite all of this progress, a deeper understanding of the differences between the mouse and human receptor is required to allow a safe translation of pre-clinical studies in efficient therapies. In this review, we discuss the role of CD28 in tolerance and autoimmunity and the clinical efficacy of drugs that block or enhance CD28 signaling, by highlighting the success and failure of pre-clinical studies, when translated to humans

Ambulatório Pais-Bebês: experiência em um hospital escola

The objective of this article is to present the work developed at the parent-baby clinic(Ambulatório Pais-Bebês) at Hospital de Clínicas de Porto Alegre, so as to emphasizethe importance of this assistance modality to professionals of related areas within thehospital environment. The authors emphasize the experience developed by aninterdisciplinary group of professionals who are dedicated to research, teaching andproviding assistance for babies and their families for about 10 years. It is hoped thatthe both research and practice will be stimulated in this area of childhood and adolescentpsychiatry, still little explored in Brazil. This collaboration among professionals resultedfrom the need to assist a growing number of babies who present development-relatedhealth problems, as well as to prevent gaps in the relationship with the caretakers. Ingeneral, although most cases are serious, intervention tends to be brief and withfavorable results. The authors believe that this may result from the fact that, between0 and 3 years of age, babies are extremely responsive to environmental changes.Therapeutic interventions that focus on such changes elicit responses from the babieswho, in turn, also stimulate their caretakers to provide better qualified care. The clinicalexperience throughout our experience has shown that the cost of such interventionsis extremely low, and as a consequence such actions should be prioritized as part ofthe effort to prevent mental problems in children.O presente artigo tem por objetivo apresentar o trabalho que vem sendo realizado noambulatório pais-bebês, enfatizando a importância desta modalidade de atendimentopara os profissionais de áreas afins, em âmbito hospitalar. Os autores destacam aexperiência desenvolvida por um grupo multidisciplinar de profissionais, que se dedicaà pesquisa, ao ensino e ao atendimento de bebês e suas famílias há cerca de 10anos. Visa-se estimular a prática e a pesquisa nessa área de conhecimento dapsiquiatria da infância e adolescência, ainda pouco exploradas em nosso país. Surgiuda necessidade de atender uma demanda crescente de bebês com problemas desaúde em diversas áreas do desenvolvimento, bem como de prevenir falhas na relaçãocom seus cuidadores. Em geral, apesar dos casos serem graves, as intervençõescostumam ser breves e com bons resultados. Os autores acreditam que isso possaocorrer em função de que, entre 0 e 3 anos de idade, os bebês são muito responsivosàs mudanças em seu ambiente. Intervenções terapêuticas, que focalizam taismudanças, provocam respostas nos bebês que, por sua vez, também estimulam seuscuidadores a proporcionarem uma maternagem mais qualificada. A experiência clínica,ao longo deste tempo, tem demonstrado que tais intervenções são de baixíssimocusto e, conseqüentemente adquirem uma magnitude prioritária na prevenção deproblemas mentais em crianças

Probing Anomalous Quartic Couplings in e-gamma and gamma-gamma Colliders

We analyze the potential of the e+e- Linear Colliders, operating in the e-gamma and gamma-gamma modes, to probe anomalous quartic vector--boson interactions through the multiple production of W's and Z's. We examine all $SU(2)_L \otimes U(1)_Y$ chiral operators of order p^4 that lead to new four--gauge--boson interactions but do not alter trilinear vertices. We show that the e-gamma and gamma-gamma modes are able not only to establish the existence of a strongly interacting symmetry breaking sector but also to probe for anomalous quartic couplings of the order of 10^{-2} at 90% CL. Moreover, the information gathered in the e-gamma mode can be used to reduced the ambiguities of the e+e- mode.Comment: Revtex, 18 pages, 6 figure

The e+e- -> Z gamma gamma -> q q gamma gamma Reaction at LEP and Constraints on Anomalous Quartic Gauge Boson Couplings

The cross section of the process e^+ e^- -> Z \gamma\gamma -> qq \gamma \gamma is measured with 215 pb^-1 of data collected with the L3 detector during the final LEP run at centre-of-mass energies around 205 GeV and 207 GeV. No deviation from the Standard Model expectation is observed. The full data sample of 713 pb^-1, collected above the Z resonance, is used to constrain the coefficients of anomalous quartic gauge boson couplings to: -0.02 GeV^-2 < a_0/\Lambda^2 < 0.03 GeV^-2 and -0.07 GeV^-2 < a_c/\Lambda^2 < 0.05 GeV^-2, at 95% confidence level

Tests of Anomalous Quartic Couplings at the NLC

We analyze the potential of the Next Linear $e^+e^-$ Collider to study anomalous quartic vector-boson interactions through the processes $e^+ e^- \to W^+W^-Z$ and $ZZZ$. In the framework of $SU(2)_L \otimes U(1)_Y$ chiral Lagrangians, we examine all effective operators of order $p^4$ that lead to four-gauge-boson interactions but do not induce anomalous trilinear vertices. In our analysis, we take into account the decay of the vector bosons to fermions and evaluate the efficiency in their reconstruction. We obtain the bounds that can be placed on the anomalous quartic interactions and we study the strategies to distinguish the possible couplings.Comment: 18 pages, ReVTeX, 3 figures, typos corrected and references adde

Combined effects of bevacizumab with erlotinib and irradiation: a preclinical study on a head and neck cancer orthotopic model

Clinical benefit has been demonstrated in patients with head and neck tumours receiving an anti-epidermal growth factor receptor (EGFR) agent in combination with radiotherapy (RT). Recent preclinical and clinical studies suggest beneficial effects from combining anti-angiogenic drugs with RT. To investigate the effect of combining these approaches, we evaluated in vivo the anti-tumour efficacy of the anti-angiogenic compound bevacizumab, a highly specific monoclonal antibody directed against the vascular endothelial growth factor (VEGF), erlotinib, an EGFR tyrosine kinase inhibitor, and irradiation given alone and in combination. Investigations were performed using a VEGF-secreting human head and neck tumour cell line, CAL33, with a high EGFR content, injected as orthotopic xenografts into the mouth floor of nude mice. Three days after tumour cell injection, bevacizumab (5 mg kg−1, 5 days a week, i.p.), erlotinib (100 mg kg−1, 5 days a week, orally) and irradiation (6 Gy, 3 days a week) were administered alone and in combination for 10 days. As compared with the control, concomitant administration of drugs produced a marked and significant supra-additive decrease in tumour mass; the addition of irradiation almost completely abolished tumour growth. The drug association markedly reduced the number of metastatic nodes and the triple combination significantly reduced the total number of pathologically positive lymph nodes as compared with controls. The RT-induced proliferation, reflected by Ki67 labelling, was reduced to control level with the triple combination. Radiotherapy induced a strong and very significant increase in tumour angiogenesis, which was no longer observed when combined with erlotinib and bevacizumab. The efficacy of the combination of bevacizumab+erlotinib and RT may be of clinical importance in the management of head and neck cancer patients

Strongly Interacting Vector Bosons at the LHC: Quartic Anomalous Couplings

We analyze the potential of the CERN Large Hadron Collider to study anomalous quartic vector--boson interactions through the production of vector--boson pairs accompanied by jets. In the framework of $SU(2)_L \otimes U(1)_Y$ chiral Lagrangians, we examine all effective operators of order $p^4$ that lead to new four--gauge--boson interactions but do not alter trilinear vertices. In our analyses, we perform the full tree level calculation of the processes leading to two jets plus vector--boson pairs, $W^+W^-$, $W^\pm W^\pm$, $W^\pm Z$, or $ZZ$, taking properly into account the interference between the standard model and the anomalous contributions. We obtain the bounds that can be placed on the anomalous quartic interactions and we study the strategies to distinguish the possible new couplings.Comment: 12 pages, ReVTeX, 5 figure

Novel regulatory therapies for prevention of Graft-versus-host disease

Graft-versus-host disease is one of the major transplant-related complications in allogeneic hematopoietic stem cell transplantation. Continued efforts have been made to prevent the occurrence of severe graft-versus-host disease by eliminating or suppressing donor-derived effector T cells. Conventional immunosuppression does not adequately prevent graft-versus-host disease, especially in mismatched transplants. Unfortunately, elimination of donor-derived T cells impairs stem cell engraftment, and delays immunologic reconstitution, rendering the recipient susceptible to post-transplant infections and disease relapse, with potentially lethal consequences. In this review, we discuss the role of dynamic immune regulation in controlling graft-versus-host disease, and how cell-based therapies are being developed using regulatory T cells and other tolerogenic cells for the prevention and treatment of graft-versus-host disease. In addition, advances in the design of cytoreductive conditioning regimens to selectively target graft-versus-host disease-inducing donor-derived T cells that have improved the safety of allogeneic stem cell transplantation are reviewed. Finally, we discuss advances in our understanding of the tolerogenic facilitating cell population, a phenotypically and functionally distinct population of bone marrow-derived cells which promote hematopoietic stem cell engraftment while reducing the risk of graft-versus-host disease