Estimators for CMB Statistical Anisotropy

We use quadratic maximum-likelihood (QML) estimators to constrain models with Gaussian but statistically anisotropic Cosmic Microwave Background (CMB) fluctuations, using CMB maps with realistic sky-coverage and instrumental noise. This approach is optimal when the anisotropy is small, or when checking for consistency with isotropy. We demonstrate the power of the QML approach by applying it to the WMAP data to constrain several models which modulate the observed CMB fluctuations to produce a statistically anisotropic sky. We first constrain an empirically motivated spatial modulation of the observed CMB fluctuations, reproducing marginal evidence for a dipolar modulation pattern with amplitude 7% at L < 60, but demonstrate that the effect decreases at higher multipoles and is 1% at L~500. We also look for evidence of a direction-dependent primordial power spectrum, finding a very statistically significant quadrupole signal nearly aligned with the ecliptic plane; however we argue this anisotropy is largely contaminated by observational systematics. Finally, we constrain the anisotropy due to a spatial modulation of adiabatic and isocurvature primordial perturbations, and discuss the close relationship between anisotropy and non-Gaussianity estimators.Comment: add missed ref. to Gordon et. al. 200

Weak lensing of the CMB

The cosmic microwave background (CMB) represents a unique source for the study of gravitational lensing. It is extended across the entire sky, partially polarized, located at the extreme distance of z=1100, and is thought to have the simple, underlying statistics of a Gaussian random field. Here we review the weak lensing of the CMB, highlighting the aspects which differentiate it from the weak lensing of other sources, such as galaxies. We discuss the statistics of the lensing deflection field which remaps the CMB, and the corresponding effect on the power spectra. We then focus on methods for reconstructing the lensing deflections, describing efficient quadratic maximum-likelihood estimators and delensing. We end by reviewing recent detections and observational prospects.Comment: 21 pages, 5 figures. Invited review for GRG special issue on gravitational lensin

On the joint analysis of CMB temperature and lensing-reconstruction power spectra

Gravitational lensing provides a significant source of cosmological information in modern CMB parameter analyses. It is measured in both the power spectrum and trispectrum of the temperature fluctuations. These observables are often treated as independent, although as they are both determined from the same map this is impossible. In this paper, we perform a rigorous analysis of the covariance between lensing power spectrum and trispectrum analyses. We find two dominant contributions coming from: (i) correlations between the disconnected noise bias in the trispectrum measurement and sample variance in the temperature power spectrum; and (ii) sample variance of the lenses themselves. The former is naturally removed when the dominant N0 Gaussian bias in the reconstructed deflection spectrum is dealt with via a partially data-dependent correction, as advocated elsewhere for other reasons. The remaining lens-cosmic-variance contribution is easily modeled but can safely be ignored for a Planck-like experiment, justifying treating the two observable spectra as independent. We also test simple likelihood approximations for the deflection power spectrum, finding that a Gaussian with a parameter-independent covariance performs well.Comment: 25+11 pages, 14 figure

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

Prefeasibility study for a small hydro project

Includes bibliographical references (p. 116-119).A prefeasibility study for the production of hydroelectricity on the Kruisvallei 190 farm was conducted. The work progression included a site assessment, preliminary layout design, a basic technical specification, and production and financial analyses

“Viewed with suspicion, considered idle and mocked-working caregiving fathers and fatherhood forfeits”

Existing academic literature consistently points to a changing role for modern fathers in which they take an egalitarian role in the caregiving responsibilities for their children. Despite this, fathers are observed to continue to dominate the realms of full-time working, aligning to more traditional breadwinning mentalities than such trends might suggest, raising questions around inequality. Fathers at work have previously been found to encounter challenges within the workplace when they alter, or consider altering their work patterns due to caregiving responsibilities. Employing a sample of working parents and managers, this paper explores how caregiving fathers are perceived within organizations and in considering their experiences, provides a nuanced and detailed understanding of the ways in which mistreatment for caregiving fathers manifests within contemporary UK workplaces. Caregiving fathers are found to face specific challenges termed “fatherhood forfeits” such as perceived idleness, suffering mockery, and being viewed with suspicion by male and female co-workers. Actions are proposed to address “fatherhood forfeits” that include specific organizational training interventions and the importance of workplace role modeling

Trouble at Work

This book is available as open access through the Bloomsbury Open Access programme and is available on www.bloomsburycollections.com. Trouble in the workplace - whether it is bullying, harassment or stress - is always in the headlines. Yet, in many discussions, the research and statistics that are cited prove unreliable. This book summarizes the largest specialist research programme on ill-treatment in the workplace so far undertaken. It provides a powerful antidote to half-truths and misinformation and offers a new way of conceptualizing trouble at work, moving the discussion away from individualized explanations - and talk of 'bullies' and 'victims' - towards the workplace characteristics that cause trouble at work. The biggest problems arise where organisations fail to create a workplace culture in which individuals really matter. Paradoxically, these are often the organizations which are well-versed in modern management practices

Openness about sexual orientation and exposure to workplace bullying

Previous studies of workplace bullying have not investigated whether Lesbian, Gay and Bisexual (LGB) employees experience bullying in similar or different ways to their heterosexual counterparts. This study reports on how and to what extent sexuality or sexual orientation influences the experience of workplace bullying and whether openness about sexual orientation elevates risks and shapes exposure to bullying. Using a large and rigorously compiled sample of the British working population comprising 500 non-heterosexuals and 722 heterosexuals (N = 1,222) and applying latent Class Cluster Analysis, a similar behavioural pattern of bullying for LGB employees emerged as for heterosexuals, although LGB employees were 1.34 times more likely to be bullied, and not being open about their sexual orientation elevated the risk of bullying. LGB employees were also more likely to be exposed to intrusive, sexualized behaviours and behaviours of an exclusionary nature. Altogether, this suggests that prejudices and stereotyping towards LGB people persist. Whilst being open about their sexual orientation did not make LGB people more likely to become a target of bullying as hypothesized, those who only reveal their sexual orientation when asked, were significantly more likely to be exposed to negative acts than those who were totally open. This indicates that non-disclosure does not prevent others at work making assumptions of sexual orientation, indicating that stereotyping of LGBs plays a greater part in disclosure than has previously been acknowledged

Taxonomic Features and Comparison of the Gut Microbiome from Two Edible Fungus-Farming Termites (Macrotermes falciger, M. natalensis) Harvested in the Vhembe District of Limpopo, South Africa

Background Termites are an important food resource for many human populations around the world, and are a good supply of nutrients. The fungus-farming ‘higher’ termite members of Macrotermitinae are also consumed by modern great apes and are implicated as critical dietary resources for early hominins. While the chemical nutritional composition of edible termites is well known, their microbiomes are unexplored in the context of human health. Here we sequenced the V4 region of the 16S rRNA gene of gut microbiota extracted from the whole intestinal tract of two Macrotermes sp. soldiers collected from the Limpopo region of South Africa. Results Major and minor soldier subcastes of M. falciger exhibit consistent differences in taxonomic representation, and are variable in microbial presence and abundance patterns when compared to another edible but less preferred species, M. natalensis. Subcaste differences include alternate patterns in sulfate-reducing bacteria and methanogenic Euryarchaeota abundance, and differences in abundance between Alistipes and Ruminococcaceae. M. falciger minor soldiers and M. natalensissoldiers have similar microbial profiles, likely from close proximity to the termite worker castes, particularly during foraging and fungus garden cultivation. Compared with previously published termite and cockroach gut microbiome data, the taxonomic representation was generally split between termites that directly digest lignocellulose and humic substrates and those that consume a more distilled form of nutrition as with the omnivorous cockroaches and fungus-farming termites. Lastly, to determine if edible termites may point to a shared reservoir for rare bacterial taxa found in the gut microbiome of humans, we focused on the genus Treponema. The majority of Treponemasequences from edible termite gut microbiota most closely relate to species recovered from other termites or from environmental samples, except for one novel OTU strain, which clustered separately with Treponema found in hunter-gatherer human groups. Conclusions Macrotermes consumed by humans display special gut microbial arrangements that are atypical for a lignocellulose digesting invertebrate, but are instead suited to the simplified nutrition in the fungus-farmer diet. Our work brings to light the particular termite microbiome features that should be explored further as avenues in human health, agricultural sustainability, and evolutionary research