Social isolation, as evidenced by objective indicators such as having a small social network,¹ being unmarried,^2,3 participating in few activities with others,^4-6 or some combination of these,^7,8 has been associated with increased risk of dementia and cognitive decline in several prospective studies. In contrast, little is known about the association of dementia with emotional isolation, or loneliness, which refers to perceived social isolation and feeling disconnected from others, that is, to dissatisfaction with social interactions rather than their absence. Although loneliness is related to social isolation, the correlation is far from perfect.⁹ The only previous study of which we are aware was based on brief measures of loneliness and cognition and had mixed results, with loneliness related to increased risk of cognitive decline in some analyses but not others.¹⁰ Thus, as previously noted,¹¹ it is uncertain how much feeling alone (ie, loneliness), as distinct from being alone (ie, social isolation), contributes to risk of dementia in old age.

Alzheimer disease (AD) is the leading cause of dementia in older persons, but few risk factors for the disease have been identified. Frequent participation in cognitively stimulating activities has been hypothesized to reduce risk of AD,^1-3 but this hypothesis has not been tested prospectively in longitudinal studies of incident disease. Support for the hypothesis now comes mainly from retrospective case-control studies suggesting that mid-life cognitive activity is associated with disease risk^4,5 and from cross-sectional research showing an association between frequency of cognitive activity and level of cognitive function in old age.^6-8 In the current study, we used a previously established measure of frequency of participation in common cognitive activities⁸ and tested its association with incident AD and decline in cognitive function in a large cohort of older Catholic clergy members examined annually for up to 7 years.

We study initial-state radiation events, $e^{+}{e}^{-}\to {\gamma }_{\mathrm{ISR}}{\pi }^{+}{\pi }^{-}J/\psi$, with data collected with the BABAR detector. We observe an accumulation of events near $4.26\mathrm{GeV}/c^2$ in the invariant-mass spectrum of ${\pi }^{+}{\pi }^{-}J/\psi$. Fits to the mass spectrum indicate that a broad resonance with a mass of about $4.26\mathrm{GeV}/c^2$ is required to describe the observed structure. The presence of additional narrow resonances cannot be excluded. The fitted width of the broad resonance is 50 to $90\mathrm{MeV}/c^2$, depending on the fit hypothesis.

We have observed a narrow state near $2.32\mathrm{G}\mathrm{e}\mathrm{V}/c^2$ in the inclusive $D_s^{+}{\pi }^0$ invariant mass distribution from $e^{+}{e}^{-}$ annihilation data at energies near 10.6 GeV. The observed width is consistent with the experimental resolution. The small intrinsic width and the quantum numbers of the final state indicate that the decay violates isospin conservation. The state has natural spin-parity and the low mass suggests a $J^P=0^{+}$ assignment. The data sample corresponds to an integrated luminosity of $91{\mathrm{f}\mathrm{b}}^{-1}$ recorded by the BABAR detector at the SLAC PEP-II asymmetric-energy $e^{+}{e}^{-}$ storage ring.