Asymmetric Beams and CMB Statistical Anisotropy

Beam asymmetries result in statistically-anisotropic cosmic microwave background (CMB) maps. Typically, they are studied for their effects on the CMB power spectrum, however they more closely mimic anisotropic effects such as gravitational lensing and primordial power asymmetry. We discuss tools for studying the effects of beam asymmetry on general quadratic estimators of anisotropy, analytically for full-sky observations as well as in the analysis of realistic data. We demonstrate this methodology in application to a recently-detected 9 sigma quadrupolar modulation effect in the WMAP data, showing that beams provide a complete and sufficient explanation for the anomaly.Comment: updated to match PRD version + typo correction in Eq. B

Linear effects of perturbed recombination

Perturbations in the ionization fraction after recombination affect the Compton cooling of density perturbations. Once the gas temperature starts to decouple from the CMB temperature, ionization fraction perturbations can have a significant influence on the subsequent gas temperature perturbation evolution. This directly affects the 21cm spin temperature of the gas, and also modifies the small-scale baryon perturbation evolution via the difference in baryon pressure. The effect on the gas temperature perturbations can be significant on all scales, and galactic-scale baryon perturbations are modified at the percent level at redshifts z >~ 100 where numerical simulations are typically started.Comment: 5 pages; for more details of effect on 21cm see astro-ph/0702600; code available at http://camb.info/sources

Design of experiments for non-manufacturing processes : benefits, challenges and some examples

Design of Experiments (DoE) is a powerful technique for process optimization that has been widely deployed in almost all types of manufacturing processes and is used extensively in product and process design and development. There have not been as many efforts to apply powerful quality improvement techniques such as DoE to improve non-manufacturing processes. Factor levels often involve changing the way people work and so have to be handled carefully. It is even more important to get everyone working as a team. This paper explores the benefits and challenges in the application of DoE in non-manufacturing contexts. The viewpoints regarding the benefits and challenges of DoE in the non-manufacturing arena are gathered from a number of leading academics and practitioners in the field. The paper also makes an attempt to demystify the fact that DoE is not just applicable to manufacturing industries; rather it is equally applicable to non-manufacturing processes within manufacturing companies. The last part of the paper illustrates some case examples showing the power of the technique in non-manufacturing environments

Implementing the Lean Sigma Framework in an Indian SME: a case study

Lean and Six Sigma are two widely acknowledged business process improvement strategies available to organisations today for achieving dramatic results in cost, quality and time by focusing on process performance. Lately, Lean and Six Sigma practitioners are integrating the two strategies into a more powerful and effective hybrid, addressing many of the weaknesses and retaining most of the strengths of each strategy. Lean Sigma combines the variability reduction tools and techniques from Six Sigma with the waste and non-value added elimination tools and techniques from Lean Manufacturing, to generate savings to the bottom-line of an organisation. This paper proposes a Lean Sigma framework to reduce the defect occurring in the final product (automobile accessories) manufactured by a die-casting process. The proposed framework integrates Lean tools (current state map, 5S System, and Total Productive Maintenance (TPM)) within Six Sigma DMAIC methodology to enhance the bottom-line results and win customer loyalty. Implementation of the proposed framework shows dramatic improvement in the key metrics (defect per unit (DPU), process capability index, mean and standard deviation of casting density, yield, and overall equipment effectiveness (OEE)) and a substantial financial savings is generated by the organisation

The 21cm angular-power spectrum from the dark ages

At redshifts z >~ 30 neutral hydrogen gas absorbs CMB radiation at the 21cm spin-flip frequency. In principle this is observable and a high-precision probe of cosmology. We calculate the linear-theory angular power spectrum of this signal and cross-correlation between redshifts on scales much larger than the line width. In addition to the well known redshift-distortion and density perturbation sources a full linear analysis gives additional contributions to the power spectrum. On small scales there is a percent-level linear effect due to perturbations in the 21cm optical depth, and perturbed recombination modifies the gas temperature perturbation evolution (and hence spin temperature and 21cm power spectrum). On large scales there are several post-Newtonian and velocity effects; although negligible on small scales, these additional terms can be significant at l <~ 100 and can be non-zero even when there is no background signal. We also discuss the linear effect of reionization re-scattering, which damps the entire spectrum and gives a very small polarization signal on large scales. On small scales we also model the significant non-linear effects of evolution and gravitational lensing. We include full results for numerical calculation and also various approximate analytic results for the power spectrum and evolution of small scale perturbations.Comment: 29 pages; significant extensions including: self-absorption terms (i.e. change to background radiation due to 21cm absorption); ionization fraction perturbations; estimates of non-linear effects; approximate analytic results; results for sharp redshift window functions. Code available at http://camb.info/sources

Aerosol chemistry in GLOBE

This task addresses the measurement and understanding of the physical and chemical properties of aerosol in remote regions that are responsible for aerosol backscatter at infrared wavelengths. Because it is representative of other clean areas, the remote Pacific is of extreme interest. Emphasis is on the determination size dependent aerosol properties that are required for modeling backscatter at various wavelengths and upon those features that may be used to help understand the nature, origin, cycling and climatology of these aerosols in the remote troposphere. Empirical relationships will be established between lidar measurements and backscatter derived from the aerosol microphysics as required by the NASA Doppler Lidar Program. This will include the analysis of results from the NASA GLOBE Survey Mission Flight Program. Additional instrument development and deployment will be carried out in order to extend and refine this data base. Identified activities include participation in groundbased and airborne experiments. Progress to date includes participation in, analysis of, and publication of results from Mauna Loa Backscatter Intercomparison Experiment (MABIE) and Global Backscatter Experiment (GLOBE)

Low Sputum Smear Positive Tuberculosis among Pulmonary Tuberculosis Suspects in a Tertiary Hospital in Mwanza, Tanzania

Early diagnosis of tuberculosis (TB) and prompt initiation of treatment are essential for an effective tuberculosis control programme. In many resource limited settings microscopic diagnosis is still the pivotal tool in the diagnosis of pulmonary TB. This study aimed at evaluating laboratory microscopic diagnosis of tuberculosis in a tertiary hospital in Mwanza, Tanzania. This retrospective hospital based study reviewed consecutively from TB registry and patients’ files a total of 5,922 TB suspects who submitted their sputum for examination between January 2007 and May 2010 at Bugando Medical Centre (BMC). Among TB suspects (mean age=36.1±13.6 years) female accounted for 54.1% of the patients. The prevalence of HIV among TB patients was 59.4%. The sputum smear positivity rate among the TB suspects was 6.1%; the rate was higher in HIV positive than in HIV negative patients (9.9 % versus 3.2%, P-value < 0.001). The overall positivity rate for the first smear was 94.2% with an incremental percentage yield of 5.2% and 0.6% for the second and third smears, respectively. The study found that 28.6% of patients who were positive in the first smear did not return for the second smear. The risk factors among smear positive TB patients were co-illness (32.5%), previous history of TB (7.5%) and history of positive TB contact (4.7%). These findings also show that as CD4+ T Cells count increases, the quantity AFB in sputum smear also increase although not statistically significant. The sputum smear positivity rate at Bugando Medical Centre is low and more than a quarter of initial TB suspects who were positive in the first smear were lost to follow up posing a threat of continuous transmission of tuberculosis to the community. The finding of more sputum smear positivity rate among HIV positive than HIV negative patients at BMC requires a prospective study to ascertain whether it is a reality or a coincidence.\u

Emotion recognition in simulated social interactions

Social context plays an important role in everyday emotional interactions, and others' faces often provide contextual cues in social situations. Investigating this complex social process is a challenge that can be addressed with the use of computergenerated facial expressions. In the current research, we use synthesized facial expressions to investigate the influence of socioaffective inferential mechanisms on the recognition of social emotions. Participants judged blends of facial expressions of shame-sadness, or of anger-disgust, in a target avatar face presented at the center of a screen while a contextual avatar face expressed an emotion (disgust, contempt, sadness) or remained neutral. The dynamics of the facial expressions and the head/gaze movements of the two avatars were manipulated in order to create an interaction in which the two avatars shared eye gaze only in the social interaction condition. Results of Experiment 1 revealed that when the avatars engaged in social interaction, target expression blends of shame and sadness were perceived as expressing more shame if the contextual face expressed disgust and more sadness when the contextual face expressed sadness. Interestingly, perceptions of shame were not enhanced when the contextual face expressed contempt. The latter finding is probably attributable to the low recognition rates for the expression of contempt observed in Experiment 2