Low Cardiorespiratory Fitness is an Independent Predictor of Metabolic Syndrome in Young Korean Adults

Objective: To investigate the relationship between cardio/respiratory fitness (CRF) and metabolic syndrome (MS) in young Korean men. Design: In a cross-sectional study, we examined 909 young Korean men (mean±SD age, 24.0±2 years) who were healthy and not taking any medications affecting blood pressure, glucose, or lipids concentrations. Body fatness, resting blood pressures, and fasting blood levels of lipids, glucose, and insulin were measured with our standardized laboratory protocols. CRF was quantified as the maximum volume of minute oxygen consumption measured during a graded treadmill test. Metabolic syndrome was defined with the National Cholesterol Education Program Adult Treatment Panel III criteria and a modified cut-off value of waist circumference from the Asia-Pacific Perspective: Redefining Obesity and its Treatment. Results: Group analyses showed significant and inverse dose-response trends between the metabolic syndrome markers and CRF levels such that men with high and moderate CRF levels had more favorable profiles in body fatness, resting blood pressures, mean values in fasting lipids, glucose, and insulin, and homeostasis model of assessment-insulin resistance than men with low CRF level. After adjusting for several potential confounders such as age, smoking, and body fatness variables, the low and moderate CRF groups had odds of 4.64 (95% CI, 2.00 to 10.79) and 2.57 (95% CI, 1.04 to 6.34) for having metabolic syndrome than the high CRF group. Conclusion: These findings suggest that low CRF is a significant and independent risk factor for metabolic syndrome in young Korean men

Forbidden Channels and SIMP Dark Matter

In this review, we focus on dark matter production from thermal freeze-out with forbidden channels and SIMP processes. We show that forbidden channels can be dominant to produce dark matter depending on the dark photon and / or dark Higgs mass compared to SIMP.Comment: 5 pages, Prepared for the proceedings of the 13th International Conference on Gravitation, 3-7 July 201

On thermal production of self-interacting dark matter

We consider thermal production mechanisms of self-interacting dark matter in models with gauged $Z_3$ symmetry. A complex scalar dark matter is stabilized by the $Z_3$, that is the remnant of a local dark $U(1)_d$. Light dark matter with large self-interaction can be produced from thermal freeze-out in the presence of SM-annihilation, SIMP and/or forbidden channels. We show that dark photon and/or dark Higgs should be relatively light for unitarity and then assist the thermal freeze-out. We identify the constraints on the parameter space of dark matter self-interaction and mass in cases that one or some of the channels are important in determining the relic density.Comment: 26 pages, 11 figures, Version to appear in Journal of High Energy Physic

Unitary inflaton as decaying dark matter

We consider the inflation model of a singlet scalar field (sigma field) with both quadratic and linear non-minimal couplings where unitarity is ensured up to the Planck scale. We assume that a $Z_2$ symmetry for the sigma field is respected by the scalar potential in Jordan frame but it is broken explicitly by the linear non-minimal coupling due to quantum gravity. We discuss the impacts of the linear non-minimal coupling on various dynamics from inflation to low energy, such as a sizable tensor-to-scalar ratio, a novel reheating process with quartic potential dominance, and suppressed physical parameters in the low energy, etc. In particular, the linear non-minimal coupling leads to the linear couplings of the sigma field to the Standard Model through the trace of the energy-momentum tensor in Einstein frame. Thus, regarding the sigma field as a decaying dark matter, we consider the non-thermal production mechanisms for dark matter from the decays of Higgs and inflaton condensate and show the parameter space that is compatible with the correct relic density and cosmological constraints.Comment: 36 pages, 7 figures, v2: minor corrections made and references added, v3: discussion on preheating added, accepted for Journal of High Energy Physics, v4: Lyman-alpha bound included and inflationary predictions refined for perturbative reheatin

A minimal flavored U(1)′U(1)' for BB-meson anomalies

We consider an anomaly-free $U(1)'$ model with favorable couplings to heavy flavors in the Standard Model(SM), as motivated by $B$-meson anomalies at LHCb. Taking the $U(1)'$ charge to be $Q'=y(L_\mu-L_\tau)+ x(B_3-L_3)$, we can explain the $B$-meson anomalies without invoking extra charged fermions or flavor violation beyond the SM. We show that there is a viable parameter space with a small $x$ that is compatible with other meson decays, tau lepton and neutrino experiments as well as the LHC dimuon searches. We briefly discuss the prospects of discovering the $Z'$ gauge boson at the LHC in the proposed model.Comment: 20 pages, 4 figures, v2: references and discussion on electroweak precision test added, v3: Version to appear in Physical Review

Chapter 1 Introduction

There is an increasing tendency to use the development experience of Asian countries as a reference point for other countries in the Global South. Korea’s condensed urbanization and industrialization, accompanied by the expansion of new cities and industrial complexes across the country, have become one such model, even if the fruits of such development may not have been equitably shared across geographies and generations. The chapters in this book critically reassess the Korean urban development experience from regional policy to new town development, demonstrating how these policy experiences were deeply rooted in Korea’s socioeconomic environment and discussing what can be learned from them when applying them in other developmental context