Observational constraints of an anisotropic boost due to the projection effects using redMaPPer clusters

Optical clusters identified from red-sequence galaxies suffer from projection effects, where interloper galaxies along the line-of-sight to a cluster are mistaken as genuine members of the cluster. In the previous study (Sunayama et al. 2020), we found that the projection effects cause the boost on the amplitudes of clustering and lensing on large scale compared to the expected amplitudes in the absence of any projection effects. These boosts are caused by preferential selections of filamentary structure aligned to the line-of-sight due to distance uncertainties in photometric surveys. We model the projection effects with two simple assumptions and develop a novel method to quantify the size of the boost using cluster-galaxy cross-correlation functions. We validate our method using mock cluster catalogs built from cosmological N-body simulations and find that we can obtain unbiased constraints on the boost parameter with our model. We then apply our analysis on the SDSS redMaPPer clusters and find that the size of the boost is roughly 20% for all the richness bins except the cluster sample with the richness bin $\lambda \in [30,40]$. This is the first study to constrain the boost parameter independent from cluster cosmology studies and provides a self-consistency test for the projection effects.Comment: 13 pages, 11 figure

Bispectrum as Baryon Acoustic Oscillation Interferometer

The galaxy bispectrum, measuring excess clustering of galaxy triplets, offers a probe of dark energy via baryon acoustic oscillations (BAOs). However up to now it has been severely underused due to the combinatorically explosive number of triangles. Here we exploit interference in the bispectrum to identify triangles that amplify BAOs. This approach reduces the computational cost of estimating covariance matrices, offers an improvement in BAO constraints equivalent to lengthening BOSS by 30%, and simplifies adding bispectrum BAO information to future large-scale redshift survey analyses.Comment: 6 pages, 3 figures; revised to match published versio

Over-abundance of orphan galaxies in the UniverseMachine

Orphan galaxies that have lost a large fraction of the dark matter subhaloes have often been invoked in semi-analytical as well as empirical models of galaxy formation. We run a mock cluster finder that mimics the optical cluster finding technique of the redMaPPer algorithm on a catalogue of galaxies with quenched star formation from one such empirical model, the UniverseMachine, and obtain the prevalence of orphan galaxies in these clusters as a function of their cluster-centric distance. We compare the fraction of orphan galaxies with the upper limits derived based on our prior observations of the weak lensing signals around satellite galaxies from SDSS redMaPPer clusters. Although the orphan fraction from the UniverseMachine is marginally consistent with the upper limits in the innermost regions of galaxy clusters spanning [0.1, 0.3] $h^{-1}$ Mpc, we observe that the orphan fractions substantially violate the upper limits in the outer regions of galaxy clusters beyond 0.3 $h^{-1}$ Mpc. We discuss the reasons, plausible improvements to the model and how observations can be used to constrain such models further.Comment: 6 pages, 5 figure

Syria and Saudi Arabia, 1978-1990: A study of the role of shared identities in alliance-making.

Syrian-Saudi relations have been a paradox in inter-Arab politics during the oil era. The two states pursued mutually conflicting aims in almost every major regional or international foreign policy issue and often propagated contrasting ideological banners over the past thirty years; yet both acted as though some form of an alignment existed between themselves. The most obvious proof for the existence and endurance of this link can be observed in the enormous financial transaction from Saudi Arabia to Syria, which came to form a lifeline for Syria's national economy. Besides the economic sphere, the two countries have consulted each other on major regional political and security issues, such as the Middle East peace process, the Lebanese civil war and Gulf security. This thesis is an empirical study of the paradoxical relations with a special emphasis on the period between the 1978 Egyptian-Israeli Camp David Accords and the 1990 Iraqi invasion of Kuwait. In the history of the bilateral relations since 1946, this twelve-year period was marked by exceptionally abundant sources of disagreements between the two actors. The examination of this period, therefore, highlights the logic behind the longevity of the cooperative relationship despite the occasional tensions and conflicting interests. The complexity of the case partly arises from the fact that neither of the two actors has occupied a central place in the other's primary security concerns, but at the same time, neither has been able to realise its own regional objectives without being concerned about what the other does. The thesis concludes that this ultimate indispensability of each other is a condition created by the historical appeal of 'shared ideologies', be they Arabism or Islam. In the politics of the Arab world, these ideologies have been transformed from shared inspirations into disciplinary standards-of what the acceptable behaviours are for the regional political actors

The River-Rafting System for Knowledge Discovery Related to Persuasion Process Conversation Logs

The purpose of this research is to develop aframework to represent the content and process of persuasion communications for overdue payment collection, thus making it possible to examine how the skilled operators have used theme related keywords concerning motivations to pay, the payment methods and the payment confirmation in their negotiation to achieve higher collection success. This paper describes a basis for modeling a persuasion process. There has been no research or methods for dealing with large amounts of conversation logs for discovering useful knowledge about persuasion processes. In this paper, we report our successful efforts in discovering a part of the distinctive features of skilled worker techniques as indicated in their conversations related to overdue payment collection and the application of our methods to communication data related to a Japanese telecommunications company.December 18-22, 2006 Hong Kong, Chin

Robustness of Baryon Acoustic Oscillations Measurements with Photometric Redshift Uncertainties

We investigate the robustness of baryon acoustic oscillations (BAO) measurements with a photometric galaxy sample using mock galaxy catalogs with various sizes of photometric redshift (photo-$z$) uncertainties. We first investigate the robustness of BAO measurements, assuming we have a perfect knowledge of photo-$z$ uncertainties. We find that the BAO shift parameter $\alpha$ can be constrained in an unbiased manner for various sizes of photometric redshift uncertainties at $z=0.251$, $0.617$, and $1.03$ as long as the number density of galaxies is high. A sparse galaxy sample causes additional noise in the covariance matrix calculation and it can bias the constraint on $\alpha$. Next, we investigate the scenario where incorrect photometric redshift uncertainties are assumed in the fitting model and find that underestimating the photo-$z$ uncertainty leads to a degradation in the constraining power on $\alpha$. In addition, we investigate BAO measurements with a cross-correlation signal between a spec-$z$ sample and a photo-$z$ sample. We find BAO constraints are unbiased and slightly tighter than the auto-correlation signal of a photo-$z$ sample. We also quantify the constraining power on $\Omega_{\rm m0}$ assuming the LSST-like covariance and find that the 95\% confidence level is $\sigma(\Omega_{\rm m0})\sim0.03$-$0.05$ corresponding to the photo-$z$ uncertainties of 1\% to 3\% respectively. Finally, we examine whether the skewness in the photometric redshift can bias the constraint on $\alpha$ and confirm that the constraint on $\alpha$ is unbiased even if we use a fitting model assuming a Gaussian photo-$z$ uncertainty.Comment: 10 pages, 11 figures, 3 table

JNK antagonizes Akt-mediated survival signals by phosphorylating 14-3-3

Life and death decisions are made by integrating a variety of apoptotic and survival signals in mammalian cells. Therefore, there is likely to be a common mechanism that integrates multiple signals adjudicating between the alternatives. In this study, we propose that 14-3-3 represents such an integration point. Several proapoptotic proteins commonly become associated with 14-3-3 upon phosphorylation by survival-mediating kinases such as Akt. We reported previously that cellular stresses induce c-Jun NH2-terminal kinase (JNK)–mediated 14-3-3ζ phosphorylation at Ser184 (Tsuruta, F., J. Sunayama, Y. Mori, S. Hattori, S. Shimizu, Y. Tsujimoto, K. Yoshioka, N. Masuyama, and Y. Gotoh. 2004. EMBO J. 23:1889–1899). Here, we show that phosphorylation of 14-3-3 by JNK releases the proapoptotic proteins Bad and FOXO3a from 14-3-3 and antagonizes the effects of Akt signaling. As a result of dissociation, Bad is dephosphorylated and translocates to the mitochondria, where it associates with Bcl-2/Bcl-xL. Because Bad and FOXO3a share the 14-3-3–binding motif with other proapoptotic proteins, we propose that this JNK-mediated phosphorylation of 14-3-3 regulates these proapoptotic proteins in concert and makes cells more susceptible to apoptotic signals