The impact of beam deconvolution on noise properties in CMB measurements: Application to Planck LFI

We present an analysis of the effects of beam deconvolution on noise properties in CMB measurements. The analysis is built around the artDeco beam deconvolver code. We derive a low-resolution noise covariance matrix that describes the residual noise in deconvolution products, both in harmonic and pixel space. The matrix models the residual correlated noise that remains in time-ordered data after destriping, and the effect of deconvolution on it. To validate the results, we generate noise simulations that mimic the data from the Planck LFI instrument. A $\chi^2$ test for the full 70 GHz covariance in multipole range $\ell=0-50$ yields a mean reduced $\chi^2$ of 1.0037. We compare two destriping options, full and independent destriping, when deconvolving subsets of available data. Full destriping leaves substantially less residual noise, but leaves data sets intercorrelated. We derive also a white noise covariance matrix that provides an approximation of the full noise at high multipoles, and study the properties on high-resolution noise in pixel space through simulations.Comment: 22 pages, 25 figure

Relative fitness of alternative male reproductive tactics in a mammal varies between years

1. In many species, males can use different behavioural tactics to achieve fertilization, so called alternative reproductive tactics (ARTs). Few field studies have measured fitness consequences of ARTs under varying environmental conditions. 2. Here we describe fitness consequences of three phenotypically plastic ARTs in the African striped mouse (Rhabdomys pumilio), and show that relative fitness of ARTs differs between years. Each year represents a different generation. 3. For the generation living under high population density tactics differed in relative fitness in accordance with the theory of conditional strategies, with highly successful territorial breeding males having 10 times higher success than solitary roaming males and 102 times higher success than adult natally philopatric males. 4. For the generation living under intermediate population density the territorial breeding and roaming tactics yielded similar fitness which would be in agreement with the theory of mixed strategies. No philopatric males occurred. 5. For the generation living under low population density roaming was the only tactic used and some roamers had very high fitness. 6. The main prediction of status dependent selection for conditional strategies is a correlation between fitness and status, often measured as body mass, but we did not find this correlation within tactics when more than one tactic was expressed in the population. 7. Female distribution seems to have an effect on which reproductive tactics male chose: female defence polygyny when females are clumped (interference competition), but a searching tactic when females are dispersed (scramble competition). In contrast to predictions arising from theory on scramble competition, male body mass was important in determining fitness only in the year when females were dispersed, but not in other years. 8. Our results indicate that the differentiation between conditional and mixed strategies is not an absolute one. In many other species environmental conditions might fluctuate temporally and spatially so that the normally sub-optimal tactic yields similar fitness to the (usually) dominant tactic, or that only a single tactic prevails. 9. We suggest the term single strategy, independent of current fitness consequences, for systems where tactics are not genetically determined, in contrast to genetically determined alternative strategies

Phenotypic matching by spot pattern potentially mediates female giraffe social associations

Animal color pattern is a phenotypic trait that may mediate assortative mixing (also known as homophily), whereby similar looking individuals have stronger social associations. Masai giraffe (Giraffa camelopardalis tippelskirchi) coat spot patterns show high variation and some spot traits appear to be heritable. Giraffes also have high visual acuity, which may facilitate intraspecific communication and recognition based on spot patterns. Giraffe groupings are dynamic, merging and splitting throughout the day, but females form long-term associations. We predicted that adult female giraffes show stronger associations with other females that have similar spot pattern traits. We quantified the spot pattern characteristics of 399 adult female Masai giraffes and determined the pattern similarity among pairs (dyads) in their social network. We then tested for an association between coat pattern similarity (spot size, shape, and orientation) and dyadic association strength, and quantified assortative mixing. The strength of social associations was positively correlated with similarity in spot shape. Our results are compatible with assortativity by coat patterns that are similar between mother and offspring, potentially reflecting an effect of relatedness on both pattern similarity and female social associations. These results offer evidence that spot pattern could function as a visual cue for intraspecific communication and kin or individual recognition in a fission-fusion species

Genes or Culture: Are Mitochondrial Genes Associated with Tool Use in Bottlenose Dolphins ( Tursiops sp.)?

Some bottlenose dolphins use marine sponges as foraging tools (‘sponging'), which appears to be socially transmitted from mothers mainly to their female offspring. Yet, explanations alternative to social transmission have been proposed. Firstly, the propensity to engage in sponging might be due to differences in diving ability caused by variation of mitochondrial genes coding for proteins of the respiratory chain. Secondly, the cultural technique of sponging may have selected for changes in these same genes (or other autosomal ones) among its possessors. We tested whether sponging can be predicted by mitochondrial coding genes and whether these genes are under selection. In 29 spongers and 54 non-spongers from two study sites, the non-coding haplotype at the HVRI locus was a significant predictor of sponging, whereas the coding mitochondrial genes were not. There was no evidence of selection in the investigated genes. Our study shows that mitochondrial gene variation is unlikely to be a viable alternative to cultural transmission as a primary driver of tool use in dolphin

Measurements of hybrid fertility and a test of mate preference for two house mouse races with massive chromosomal divergence

Abstract Background Western house mice Mus musculus domesticus are among the most important mammalian model species for chromosomal speciation. Hybrids between chromosomal races of M. m. domesticus suffer various degrees of fertility reduction between full fertility and complete sterility, depending on the complexity of the chromosomal differences between the races. This complexity presents itself in hybrids as meiotic configurations of chromosome chains and rings, with longer configurations having a stronger impact on fertility. While hybrids with short configurations have been intensively studied, less work has been done on hybrids with very long configurations. In this study, we investigated laboratory-reared wild mice from two chromosomally very different races in Switzerland found in close proximity. Hybrids between these races form a meiotic chain of fifteen chromosomes. We performed a detailed analysis of male and female hybrid fertility, including three generations of female backcrosses to one of the parental races. We also tested for possible divergence of mate preference in females. Results While all male F1 hybrids were sterile with sperm counts of zero, 48% of female F1 hybrids produced offspring. Their litter sizes ranged from one to three which is significantly lower than the litter size of parental race females. When hybrid females were backcrossed to a parental race, half of the offspring resembled the parental race in karyotype and fertility, while the other half resembled the F1 hybrids. In the preference test, females of both races indicated a lack of a preference for males of their own karyotype. Conclusions Although the fertility of the F1 hybrids was extremely low because of the complexity of the chromosomal differences between the races, reproductive isolation was not complete. As we did not find assortative female preferences, we expect that contact between these races would lead to the production of hybrids and that gene flow would occur eventually, as fertility can be restored fully after one backcross generation

Exploring cosmic origins with CORE : Gravitational lensing of the CMB

Lensing of the cosmic microwave background (CMB) is now a well-developed probe of the clustering of the large-scale mass distribution over a broad range of redshifts. By exploiting the non-Gaussian imprints of lensing in the polarization of the CMB, the CORE mission will allow production of a clean map of the lensing deflections over nearly the full-sky. The number of high-SAN modes in this map will exceed current CMB lensing maps by a factor of 40, and the measurement will be sample-variance limited on all scales where linear theory is valid. Here, we summarise this mission product and discuss the science that will follow from its power spectrum and the cross-correlation with other clustering data. For example, the summed mass of neutrinos will be determined to an accuracy of 17 meV combining CORE lensing and CMB two-point information with contemporaneous measurements of the baryon acoustic oscillation feature in the clustering of galaxies, three times smaller than the minimum total mass allowed by neutrino oscillation measurements. Lensing has applications across many other science goals of CORE, including the search for B-mode polarization from primordial gravitational waves. Here, lens-induced B-modes will dominate over instrument noise, limiting constraints on the power spectrum amplitude of primordial gravitational waves. With lensing reconstructed by CORE, one can "delens" the observed polarization internally, reducing the lensing B-mode power by 60 %. This can be improved to 70 % by combining lensing and measurements of the cosmic infrared background from CORE, leading to an improvement of a factor of 2.5 in the error on the amplitude of primordial gravitational waves compared to no delensing (in the null hypothesis of no primordial B-modes). Lensing measurements from CORE will allow calibration of the halo masses of the tens of thousands of galaxy clusters that it will find, with constraints dominated by the clean polarization-based estimators. The 19 frequency channels proposed for CORE will allow accurate removal of Galactic emission from CMB maps. We present initial findings that show that residual Galactic foreground contamination will not be a significant source of bias for lensing power spectrum measurements with CORE.Peer reviewe

Collisional perturbation of radio-frequency E1 transitions in an atomic beam of dysprosium

We have studied collisional perturbations of radio-frequency (rf) electric-dipole (E1) transitions between the nearly degenerate opposite-parity levels in atomic dysprosium (Dy) in the presence of 10 to 80 $\mu$Torr of H$_\text{2}$, N$_\text{2}$, He, Ar, Ne, Kr, and Xe. Collisional broadening and shift of the resonance, as well as the attenuation of the signal amplitude are observed to be proportional to the foreign-gas density with the exception of H$_2$ and Ne, for which no shifts were observed. Corresponding rates and cross sections are presented. In addition, rates and cross sections for O$_2$ are extracted from measurements using air as foreign gas. The primary motivation for this study is the need for accurate determination of the shift rates, which are needed in a laboratory search for the temporal variation of the fine-structure constant [A. T. Nguyen, D. Budker, S. K. Lamoreaux, and J. R. Torgerson, Phys. Rev. A \textbf{69}, 22105 (2004)].Comment: 11 pages, 8 figure

Popular Culture, Radical Egalitarianism, and Formations of Muslim Selfhood in South Asia

In early twentieth century leftist politics on the geographical fringes of South Asia, Islam played a major role. Were activists in these movements leftist despite their understandings of Islam, or because of them? This essay introduces the project represented in the essays of this special section of South Asian History and Culture, as well as the essays that will appear in a complementary section in a subsequent issue this year. The editors of this project reconstruct a conversation on surprising resonances in subaltern sources in Pashto and Bengali of early twentieth-century grassroots indigenous traditions of radical Muslim egalitarianism. What should we make of these resonances? Building on Latin American decolonisation theory in the wake of Subaltern Studies, we introduce a series of articles that together illustrate what Ramon Grosfoguel calls a ‘pluriverse’ of perspectives on the ethical self: some rooted in the local lifeworlds of Bengal and some in the Afghan borderland; all interlinked through a series of ‘middle actors’. In so doing, we excavate some dense but hidden two-way traffic between subaltern worlds of Muslim piety and devotion on two distant ends of South Asia, and all-India, international or cosmopolitan politics. These together helped constitute a surprising amount of what we know as the South Asian left, from what are usually seen as its geographical, social, and especially intellectual peripheries

Female-biased dispersal in the solitarily foraging slender mongoose, Galerella sanguinea, in the Kalahari

Sex-biased dispersal is common in most mammals, but a female bias is less so and exceptionally rare in solitary mammals. Here we present genetic and observational evidence for strong female-biased dispersal in a solitary foraging small carnivore, the slender mongoose. We suggest that females benefit from dispersal by avoiding kin competition over local resources and inbreeding, while males can benefit from philopatry through kin cooperation leading to an increased success in female defence. The comparison between our observations and those of a previous study in Tanzania suggest that there is ecologically influenced flexibility in dispersal patterns within this species, influencing sex-specific benefits of dispersal and philopatry. Comparing our results with those on the closely related, more social mongoose species in which both sexes commonly disperse suggests that dispersal patterns are linked to a species' social system by the opportunity, or lack of it, in philopatry to obtain unrelated mating partners and gain indirect fitness benefits

Manipulating mud: (re-)constructing cosmogonical landscapes in the Nile Valley, Thebes, Egypt

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