E7(7) invariant Lagrangian of d=4 N=8 supergravity

We present an E7(7) invariant Lagrangian that leads to the equations of motion of d=4 N=8 supergravity without using Lagrange multipliers. The superinvariance of this new action and the closure of the supersymmetry algebra are proved explicitly for the terms that differ from the Cremmer--Julia formulation. Since the diffeomorphism symmetry is not realized in the standard way on the vector fields, we switch to the Hamiltonian formulation in order to prove the invariance of the E7(7) invariant action under general coordinate transformations. We also construct the conserved E7(7)-Noether current of maximal supergravity and we conclude with comments on the implications of this manifest off-shell E7(7)-symmetry for quantizing d=4 N=8 supergravity, in particular on the E7(7)-action on phase space.Comment: 45 pages, references adde

Domain walls in three dimensional gauged supergravity

We explicitly construct two Chern-Simons gauged supergravities in three dimensions with N=4 and N=8 supersymmetries and non-semisimple gauge groups. The N=4 theory has scalar manifold $SO(4,3)/SO(4)\times SO(3)$ with the gauge group $SO(3)\ltimes (\mathbf{T}^3,\hat{\mathbf{T}}^3)$. The theory describes (1,0) six dimensional supergravity reduced on an SU(2) group manifold. The equivalent Yang-Mills type gauged supergravity has SO(3) gauge group coupled to three massive vector fields. The N=8 theory is described by $SO(8,8)/SO(8)\times SO(8)$ scalar manifold, and the gauge group is given by $SO(8)\ltimes \mathbf{T}^{28}$. The theory is a truncation of the $SO(8)\ltimes \mathbf{T}^{28}$ gauged N=16 theory with scalar manifold $E_{8(8)}/SO(16)$ and can be obtained by an S^7 compactification of type I theory in ten dimensions. Domain wall solutions of both gauged supergravities are analytically found and can be uplifted to higher dimensions. These provide domain wall vacua in the three dimensional gauged supergravity framework which might be useful for the study of Domain Wall$_3$/QFT$_2$ correspondence.Comment: 19 pages, no figures, typoes and a mistake in a sign corrected, clarifications on the notations adde

On the perturbative S-matrix of generalized sine-Gordon models

Motivated by its relation to the Pohlmeyer reduction of AdS_5 x S^5 superstring theory we continue the investigation of the generalized sine-Gordon model defined by SO(N+1)/SO(N) gauged WZW theory with an integrable potential. Extending our previous work (arXiv:0912.2958) we compute the one-loop two-particle S-matrix for the elementary massive excitations. In the N = 2 case corresponding to the complex sine-Gordon theory it agrees with the charge-one sector of the quantum soliton S-matrix proposed in hep-th/9410140. In the case of N > 2 when the gauge group SO(N) is non-abelian we find a curious anomaly in the Yang-Baxter equation which we interpret as a gauge artifact related to the fact that the scattered particles are not singlets under the residual global subgroup of the gauge group

Retrograde semaphorin-plexin signalling drives homeostatic synaptic plasticity.

Homeostatic signalling systems ensure stable but flexible neural activity and animal behaviour. Presynaptic homeostatic plasticity is a conserved form of neuronal homeostatic signalling that is observed in organisms ranging from Drosophila to human. Defining the underlying molecular mechanisms of neuronal homeostatic signalling will be essential in order to establish clear connections to the causes and progression of neurological disease. During neural development, semaphorin-plexin signalling instructs axon guidance and neuronal morphogenesis. However, semaphorins and plexins are also expressed in the adult brain. Here we show that semaphorin 2b (Sema2b) is a target-derived signal that acts upon presynaptic plexin B (PlexB) receptors to mediate the retrograde, homeostatic control of presynaptic neurotransmitter release at the neuromuscular junction in Drosophila. Further, we show that Sema2b-PlexB signalling regulates presynaptic homeostatic plasticity through the cytoplasmic protein Mical and the oxoreductase-dependent control of presynaptic actin. We propose that semaphorin-plexin signalling is an essential platform for the stabilization of synaptic transmission throughout the developing and mature nervous system. These findings may be relevant to the aetiology and treatment of diverse neurological and psychiatric diseases that are characterized by altered or inappropriate neural function and behaviour

Intensive induction chemotherapy with C-BOP/BEP for intermediate- and poor-risk metastatic germ cell tumours (EORTC trial 30948)

New chemotherapy regimens are continuously explored in patients with high-risk malignant germ cell tumours (MGCTs). This multicentre phase II trial assessed the efficacy and toxicity of C-BOP/BEP chemotherapy in intermediate and poor prognosis MGCT (IGCCCG criteria). C-BOP/BEP treatment consisted of cycles of cisplatin, vincristine, bleomycin and carboplatin, followed by one cycle of vincristine and bleomycin and three cycles of BEP (bleomycon, etoposide, cisplatin). The trial was designed to demonstrate a 1-year progression-free survival rate of 80%, that is, to exclude a 1-year rate of 70% or less, with a one-sided significance level of 5%. Secondary end points included toxicity, overall survival and the postchemotherapy complete response rate. In total, 16 European hospitals entered 66 eligible patients (intermediate prognosis group: 37; poor prognosis group: 29). A total of 45 patients (68.2%, 95% confidence interval (95% CI): 56.9–79.4%) achieved a complete response (intermediate prognosis: 30; poor prognosis: 15). After a median observation time of 40.4 months (range: 13.7–66.3), the 1-year progression-free survival rate was 81.8% 95% CI: 72.5–91.1%). The 2-year overall survival was 84.5% (95% CI: 75.6–93.3%). In all, 51 patients experienced at least one episode of WHO grade 3/4 leucopenia, and at least one event of grade 3/4 thrombocytopenia occurred in 30 patients. There was no toxic death. With an 82% 1-year progression-free survival and a lower limit of the 95% CI above 70%, the efficacy of C-BOP/BEP is comparable to that of published alternative chemotherapy schedules in high-risk MGCT patients. The treatment's toxicity is manageable in a multicentre setting. In poor prognosis patients, C-BOP/BEP should be compared to standard chemotherapy of four cycles of BEP

Effects of a short individually tailored counselling session for HIV prevention in gay and bisexual men receiving Hepatitis B vaccination

Background. There is currently a trend towards unsafe unprotected anal intercourse (UAI) among men who have sex with men. We evaluated a short individual counselling session on reducing UAI among gay and bisexual men. Methods. A quasi-experimental design was used to evaluate the counselling session. This session was conducted during consulting hours at four municipal health clinics during a Hepatitis B vaccination campaign. These clinics offered free vaccination to high-risk groups, such as gay and bisexual men. All gay and bisexual men attending health clinics in four cities in the Netherlands were asked to participate. Each participant in the intervention group received a fifteen-minute individual counselling based on the Theory of Planned Behaviour and Motivational Interviewing. Changes in UAI were measured over a 5-months period, using self-administered questionnaires. UAI was measured separately for receptive and insertive intercourse in steady and casual partners. These measures were combined in an index-score (range 0-8). Results. While UAI in the counselling group remained stable, it increased in the controls by 66% from 0.41 to 0.68. The results show that the intervention had a protective effect on sexual behaviour with steady partners. Intervention effects were strongest within steady relationships, especially for men whose steady-relationship status changed during the study. The intervention was well accepted among the target group. Conclusion. The fifteen-minute individually tailored counselling session was not only well accepted but also had a protective effect on risk behaviour after a follow-up of six months

Prevalence and impact of alcohol and other drug use disorders on sedation and mechanical ventilation: a retrospective study

BACKGROUND: Experience suggests that patients with alcohol and other drug use disorders (AOD) are commonly cared for in our intensive care units (ICU's) and require more sedation. We sought to determine the impact of AOD on sedation requirement and mechanical ventilation (MV) duration. METHODS: Retrospective review of randomly selected records of adult patients undergoing MV in the medical ICU. Diagnoses of AOD were identified using strict criteria in Diagnostic and Statistical Manual of Mental Disorders, and through review of medical records and toxicology results. RESULTS: Of the 70 MV patients reviewed, 27 had AOD (39%). Implicated substances were alcohol in 22 patients, cocaine in 5, heroin in 2, opioids in 2, marijuana in 2. There was no difference between AOD and non-AOD patients in age, race, or reason for MV, but patients with AOD were more likely to be male (21 versus 15, p < 0.0001) and had a lower mean Acute Physiology and Chronic Health Evaluation II (22 versus 26, p = 0.048). While AOD patients received more lorazepam equivalents (0.5 versus 0.2 mg/kg.day, p = 0.004), morphine equivalents (0.5 versus 0.1 mg/kg.day, p = 0.03) and longer duration of infusions (16 versus 10 hours/day. medication, p = 0.002), they had similar sedation levels (Richmond Agitation-Sedation Scale (RASS) -2 versus -2, p = 0.83), incidence of agitation (RASS ≥ 3: 3.0% versus 2.4% of observations, p = 0.33), and duration of MV (3.6 versus 3.9 days, p = 0.89) as those without AOD. CONCLUSION: The prevalence of AOD among medical ICU patients undergoing MV is high. Patients with AOD receive higher doses of sedation than their non-AOD counterparts to achieve similar RASS scores but do not undergo longer duration of MV