Like Parent, Like Child: Intergenerational Patterns of Cardiovascular Risk Factors at Midlife

Purpose: We aimed to assess the prevalence of four cardiovascular risk factors (obesity, diabetes, excessive alcohol intake, and cigarette smoking) for parents and their adult children at the same approximate midlife age. We also evaluated associations of parents' cardiovascular risk factors, childhood health exposures, and social contexts (i.e., family, school, and neighborhood) during adolescence with adult children's cardiovascular health at midlife. Methods: We used data from respondents at Wave V of the National Longitudinal Study of Adolescent to Adult Health who had corresponding parent (mostly mothers) data from Wave I. The final sample included 10,466 adult children with a mean age of 37.8 years. Descriptive statistics and logistic regression models were estimated, accounting for the National Longitudinal Study of Adolescent to Adult Health sampling design. Results: At similar ages (i.e., 35–45 years) to their parents, adult children had higher rates of excessive drinking and obesity than their parents, lower rates of diabetes, and similar rates of smoking. Adult children's health largely converged and correlated with their parents' health at similar ages. Cardiovascular risks for adult children were also significantly associated with their childhood health exposures and social contexts during adolescence. Some associations varied with respect to the health status of parents at Wave I. Conclusions: The cardiovascular risk of parents at midlife is strongly associated with the cardiovascular risk of their adult children at midlife. The status of parents' health during adolescence can also modify the significance and magnitude of associations between childhood health exposures or adolescent social contexts and adult children's cardiovascular risk factors

The Role of Family Health History in Predicting Midlife Chronic Disease Outcomes

Introduction: The generational relevance for determining disease risk for the leading causes of morbidity and mortality for U.S. adults is a source of debate. Methods: Data on 12,300 adults (Add Health Study Members) participating in Wave V (2016–2018) of the National Longitudinal Study of Adolescent to Adult Health (also known as Add Health) were merged with data from respondents’ parents (n=2,013) participating in the Add Health Parent Study (2015–2017). Analyses beginning in January 2020 examined the concordance in lifetime occurrence of chronic conditions across 4 generations, including cardiovascular disease, diabetes, hypertension, hyperlipidemia, obesity, cancer, and depression and examined the associations between individual disease history and ones’ family health history for the same condition. Results: Mean ages were 37.4 years for Add Health Study Members and 62.9 years for Add Health Parent Study mothers. The histories of mothers from the Add Health Parent Study on hyperlipidemia (AOR=1.61, 95% CI=1.04, 2.48), obesity (AOR=1.77, 95% CI=1.27, 2.48), and depression (AOR=1.87, 95% CI=1.19, 2.95) were significantly associated with increased odds of Add Health Study Member report of these conditions. Maternal great grandparent hyperlipidemia history was significantly associated with the Add Health Study Member hyperlipidemia (AOR=2.81, 95% CI=1.51, 5.21). Histories of diabetes in maternal grandfather (AOR=2.41, 95% CI=1.24, 4.69) and maternal great grandparent (AOR=3.05, 95% CI=1.45, 6.43) were significantly associated with Add Health Study Member diabetes. Each additional point in the Add Health Parent Study mothers’ cardiometabolic risk factor index was associated with an 11% increase (incidence rate ratio=1.11, 95% CI=1.04, 1.19) in the expected count of cardiometabolic risk conditions for the Add Health Study Members. Conclusions: Multigenerational health histories have value for quantifying the probability of diabetes, obesity, depression, and hyperlipidemia in early mid-adulthood. Family health history knowledge is relevant for health promotion and disease prevention strategies

Sliding Luttinger liquid phases

We study systems of coupled spin-gapped and gapless Luttinger liquids. First, we establish the existence of a sliding Luttinger liquid phase for a system of weakly coupled parallel quantum wires, with and without disorder. It is shown that the coupling can {\it stabilize} a Luttinger liquid phase in the presence of disorder. We then extend our analysis to a system of crossed Luttinger liquids and establish the stability of a non-Fermi liquid state: the crossed sliding Luttinger liquid phase (CSLL). In this phase the system exhibits a finite-temperature, long-wavelength, isotropic electric conductivity that diverges as a power law in temperature $T$ as $T \to 0$. This two-dimensional system has many properties of a true isotropic Luttinger liquid, though at zero temperature it becomes anisotropic. An extension of this model to a three-dimensional stack exhibits a much higher in-plane conductivity than the conductivity in a perpendicular direction.Comment: Revtex, 18 pages, 8 figure

Changes in Optical Conductivity due to Readjustments in Electronic Density of States

Within the model of elastic impurity scattering, we study how changes in the energy dependence of the electronic density of states (EDOS) $N(\epsilon)$ around the Fermi energy $\epsilon_F$ are reflected in the frequency-dependent optical conductivity $\sigma(\omega)$. While conserving the total number of states in $N(\epsilon)$ we compute the induced changes in $\sigma(\omega)$ as a function of $\omega$ and in the corresponding optical scattering rate $1/\tau_{\rm op}(\omega)$. These quantities mirror some aspects of the EDOS changes but the relationship is not direct. Conservation of optical oscillator strength is found not to hold, and there is no sum rule on the optical scattering rate although one does hold for the quasiparticle scattering. Temperature as well as increases in impurity scattering lead to additional changes in optical properties not seen in the constant EDOS case. These effects have their origin in an averaging of the EDOS around the Fermi energy $\epsilon_F$ on an energy scale set by the impurity scattering.Comment: 13 pages, 7 figure

Sum rules and energy scales in the high-temperature superconductor YBa2Cu3O6+x

The Ferrell-Glover-Tinkham (FGT) sum rule has been applied to the temperature dependence of the in-plane optical conductivity of optimally-doped YBa_2Cu_3O_{6.95} and underdoped YBa_2Cu_3O_{6.60}. Within the accuracy of the experiment, the sum rule is obeyed in both materials. However, the energy scale \omega_c required to recover the full strength of the superfluid \rho_s in the two materials is dramatically different; \omega_c \simeq 800 cm^{-1} in the optimally doped system (close to twice the maximum of the superconducting gap, 2\Delta_0), but \omega_c \gtrsim 5000 cm^{-1} in the underdoped system. In both materials, the normal-state scattering rate close to the critical temperature is small, \Gamma < 2\Delta_0, so that the materials are not in the dirty limit and the relevant energy scale for \rho_s in a BCS material should be twice the energy gap. The FGT sum rule in the optimally-doped material suggests that the majority of the spectral weight of the condensate comes from energies below 2\Delta_0, which is consistent with a BCS material in which the condensate originates from a Fermi liquid normal state. In the underdoped material the larger energy scale may be a result of the non-Fermi liquid nature of the normal state. The dramatically different energy scales suggest that the nature of the normal state creates specific conditions for observing the different aspects of what is presumably a central mechanism for superconductivity in these materials.Comment: RevTeX 4 file, 9 pages with 7 embedded eps figure

Pulsed Magnetic Field Measurements of the Composite Fermion Effective Mass

Magnetotransport measurements of Composite Fermions (CF) are reported in 50 T pulsed magnetic fields. The CF effective mass is found to increase approximately linearly with the effective field $B^*$, in agreement with our earlier work at lower fields. For a $B^*$ of 14 T it reaches $1.6m_e$, over 20 times the band edge electron mass. Data from all fractions are unified by the single parameter $B^*$ for all the samples studied over a wide range of electron densities. The energy gap is found to increase like $\sqrt{B^*}$ at high fields.Comment: Has final table, will LaTeX without error

A Theory for High-TcT_c Superconductors Considering Inhomogeneous Charge Distribution

We propose a general theory for the critical $T_c$ and pseudogap $T^*$ temperature dependence on the doping concentration for high-$T_c$ oxides, taking into account the charge inhomogeneities in the $CuO_2$ planes. The well measured experimental inhomogeneous charge density in a given compound is assumed to produce a spatial distribution of local $\rho(r)$. These differences in the local charge concentration is assumed to yield insulator and metallic regions, possibly in a stripe morphology. In the metallic region, the inhomogeneous charge density yields also spatial distributions of superconducting critical temperatures $T_c(r)$ and zero temperature gap $\Delta_0(r)$. For a given sample, the measured onset of vanishing gap temperature is identified as the pseudogap temperature, that is, $T^*$, which is the maximum of all $T_c(r)$. Below $T^*$, due to the distribution of $T_c(r)$'s, there are some superconducting regions surrounded by insulator or metallic medium. The transition to a superconducting state corresponds to the percolation threshold among the superconducting regions with different $T_c(r)$'s. To model the charge inhomogeneities we use a double branched Poisson-Gaussian distribution. To make definite calculations and compare with the experimental results, we derive phase diagrams for the BSCO, LSCO and YBCO families, with a mean field theory for superconductivity using an extended Hubbard Hamiltonian. We show also that this novel approach provides new insights on several experimental features of high-$T_c$ oxides.Comment: 7 pages, 5 eps figures, corrected typo

Magnetotransport in the Normal State of La1.85Sr0.15Cu(1-y)Zn(y)O4 Films

We have studied the magnetotransport properties in the normal state for a series of La1.85Sr0.15Cu(1-y)Zn(y)O4 films with values of y, between 0 and 0.12. A variable degree of compressive or tensile strain results from the lattice mismatch between the substrate and the film, and affects the transport properties differently from the influence of the zinc impurities. In particular, the orbital magnetoresistance (OMR) varies with y but is strain-independent. The relations for the resistivity and the Hall angle and the proportionality between the OMR and tan^2 theta are followed about 70 K. We have been able to separate the strain and impurity effects by rewriting the above relations, where each term is strain-independent and depends on y only. We also find that changes in the lattice constants give rise to closely the same fractional changes in other terms of the equation.The OMR is more strongly supressed by the addition of impurities than tan^2 theta. We conclude that the relaxation ratethat governs Hall effect is not the same as for the magnetoresistance. We also suggest a correspondence between the transport properties and the opening of the pseudogap at a temperature which changes when the La-sr ratio changes, but does not change with the addition of the zinc impurities

Role of Inter-Electron Interaction in the Pseudo-Gap Opening in High T c_c Tunneling Experiments

The analysis of tunneling experiments showing the pseudogap type behavior is carried out based on the idea of the renormalization of density of states due to the inter-electron interaction in the Cooper channel (superconducting fluctuations contribution in tunneling current). It is demonstrated that the observed kink of the zero-bias conductance $G(0,T)$ of $YBaCuO/Pb$ junctions in the vicinity of $T_c$ can be explained in terms of fluctuation theory in a quite wide range of temperature above $T_c$, using the values of microscopic parameters of the $YBaCuO$ electron spectrum taken from independent experiments. The approach proposed also permits to explain qualitatively the shape of the tunneling anomalies in $G(V,T)$ and gives a correct estimate for the pseudogap position and amplitude observed in the experiments on $BiSrCaCuO$ junctions.Comment: 5 pages, 3 figure