Coupled Bunch Instabilities in the LHC

In the LHC, the coupled bunch instabilities will be mainly driven by the RF cavities and the resistive wall effect. The growth times of these instabilities have been estimated taking into consideration the undamped and damped higher order modes of these cavities. These estimates show that the rise times of the longitudinal coupled bunch instabilities are under control. The proposed transverse feed-back system allows the same conclusion to be drawn for the transverse resistive wall instability

Intermediate Review of Single Bunch Collective Effects in the LHC

This paper presents an intermediate review of the single bunch collective effects in the LHC. It first reviews the LHC impedance budget including all elements for which a design is presently available. Then, based on this updated budget, the corresponding rise times and thresholds for single bunch instabilities are evaluated and discussed

IgG light chain-independent secretion of heavy chain dimers: consequence for therapeutic antibody production and design

Rodent monoclonal antibodies with specificity towards important biological targets are developed for therapeutic use by a process of humanisation. This process involves the creation of molecules, which retain the specificity of the rodent antibody but contain predominantly human coding sequence. Here we show that some humanised heavy chains can fold, form dimers and be secreted even in the absence of light chain. Quality control of recombinant antibody assembly in vivo is thought to rely upon folding of the heavy chain CH1 domain. This domain acts as a switch for secretion, only folding upon interaction with the light chain CL domain. We show that the secreted heavy-chain dimers contain folded CH1 domains and contribute to the heterogeneity of antibody species secreted during the expression of therapeutic antibodies. This subversion of the normal quality control process is dependent upon the heavy chain variable domain, is prevalent with engineered antibodies and can occur when only the Fab fragments are expressed. This discovery will impact on the efficient production of both humanised antibodies as well as the design of novel antibody formats

Machine-Related Backgrounds in the SiD Detector at ILC

With a multi-stage collimation system and magnetic iron spoilers in the tunnel, the background particle fluxes on the ILC detector can be substantially reduced. At the same time, beam-halo interactions with collimators and protective masks in the beam delivery system create fluxes of muons and other secondary particles which can still exceed the tolerable levels for some of the ILC sub-detectors. Results of modeling of such backgrounds in comparison to those from the e+ e- interactions are presented in this paper for the SiD detector.Comment: 29 pages, 34 figures, 7 table

Design of the beam delivery system for the International Linear Collider

online : http://pac07.org/proceedings/PAPERS/WEOCAB01.PDFInternational audienceThe beam delivery system for the linear collider focuses beams to nanometer sizes at its interaction point, collimates the beam halo to provide acceptable background in the detector and has a provision for state-of-the-art beam instrumentation in order to reach the ILCs physics goals. this paper describes the design details and status of the baseline configuration considered for the reference design and also lists alternatives

The conceptual design of CLARA, a novel fel test facility for ultra-short pulse generation

CLARA will be a novel FEL test facility focussed on the generation of ultra-short photon pulses with extreme levels of stability and synchronisation. The principal aim is to experimentally demonstrate that sub-cooperation length pulse generation with FELs is viable, and to compare the various schemes being championed. The results will translate directly to existing and future X-ray FELs, enabling them to generate attosecond pulses, thereby extending their science capabilities. This paper gives an overview of the motivation for CLARA, describes the facility design (reported in detail in the recently published Conceptual Design Report [1]) and proposed operating modes and summarises the proposed areas of FEL research

ATF2 Proposal

ATF2 Group Accelerator Physic

Toxoplasmosis in HIV and non HIV prisoners in Malaysia

This is the first Malaysian study to determine the trend and risk factors of Toxoplasma gondii infection in HIV and non-HIV among prisoners in terms of socio-demographic and behavioural characteristics, clinical presentations and haematological distributions. Blood samples from 303 participants, comprising 133 HIV positive and 170 HIV negative inmates were collected in EDTA and plain tubes. Two mls of each blood sample in plain tubes were centrifuged at 1500 rpm for 10 minutes and the sera obtained were subjected to ELISA for detection of Toxoplasma IgM and IgG antibody towards Toxoplasma antigen. Seropositive samples for Toxoplasma IgM or both Toxoplasma IgM and IgG were further tested with Novalisa Toxoplasma gondii IgG avidity test to rule out acute from latent infections. Blood in EDTA tubes were sent to Clinical Diagnostic Lab (CDL), University Malaya Medical Centre (UMMC), Kuala Lumpur for complete blood count and differential count analysis. Overall seroprevalence of anti-T. gondii antibodies was detected in 41.9% (127 out of 303) of the participants. Anti-T. gondii antibodies was detected in 63.2% (84 out of 133) of HIV positive subjects and in 25.3% (43 out of 170) of HIV negative subjects. Seroprevalence of anti-T. gondii antibodies was significantly higher in HIV positive than in HIV negative subjects (OR = 5.06; 95% CI = 3.09-8.30; p < 0.001). The rate of T. gondii seropositivity increased significantly in those aged 40 years and above, HIV positive individuals and those with history of drug abuse. White blood cells (WBCs), neutrophils and basophils counts decreased significantly in those infected with Toxoplasma. Creating awareness about T. gondii infection and follow-up of their status is recommended. Moreover, screening of T. gondii infection in HIV-infected individuals should be considered for better treatment and management, including control and prevention