We have searched for infrared excesses around a well defined sample of 69 FGK main-sequence field stars. These stars were selected without regard to their age, metallicity, or any previous detection of IR excess; they have a median age of ∼4 Gyr. We have detected 70 µm excesses around 7 stars at the 3-σ confidence level. This extra emission is produced by cool material (< 100 K) located beyond 10 AU, well outside the "habitable zones" of these systems and consistent with the presence of Kuiper Belt analogs with ∼100 times more emitting surface area than in our own planetary system. Only one star, HD 69830, shows excess emission at 24 µm, corresponding to dust with temperatures > ∼ 300 K located inside of 1 AU. While debris disks with L dust /L ⋆ ≥ 10 −3 are rare around old FGK stars, we find that the disk frequency increases from 2 ± 2% for L dust /L ⋆ ≥ 10 −4 to 12 ± 5% for L dust /L ⋆ ≥ 10 −5 . This trend in the disk luminosity distribution is consistent with the estimated dust in our solar system being within an order of magnitude, greater or less, than the typical level around similar nearby stars.

Recent images of the disks of dust around the young stars HR 4796A (Jayawardhana et al. 1998;Koerner et al. 1998;Schneider et al. 1999;Telesco et al. 1999) and Fomalhaut (Holland et al. 1998) show, in each case, a double-lobed feature that may be asymmetric (one lobe may be brighter than the other). A symmetric double-lobed structure is that expected from a disk of dust with a central hole that is observed nearly edge-on (i.e., close to the plane of the disk). This paper shows how the gravitational influence of a second body in the system with an eccentric orbit would cause a brightness asymmetry in such a disk by imposing a "forced eccentricity" on the orbits of the constituent dust particles, thus shifting the center of symmetry of the disk away from the star and causing the dust near the forced pericenter of the perturbed disk to glow. Dynamic modeling of the HR 4796 disk shows that its ∼ 5% brightness asymmetry could be the result of a forced eccentricity as small as 0.02 imposed on the disk by either the binary companion HR 4796B, or by an unseen planet close to the inner edge of the disk. Since it is likely that a forced eccentricity of 0.01 or higher would be imposed on a disk in a system in which there are planets, but no binary companion, the corresponding asymmetry in the disk's structure could serve as a sensitive indicator of these planets that might otherwise remain undetected.

The impact of cancer on the Canadian population and health care systems is substantial. Cancer is the leading cause of death in Canada 1,2 and previous estimates have shown that 43% of all people in Canada are expected to receive a cancer diagnosis in their lifetime. 3 With an aging and growing population, the number of new cancer cases and deaths in Canada is also increasing. 4 In addition to its impact on health, cancer is costly. The economic burden of cancer care in Canada rose from $2.9 billion in 2005 to $7.5 billion in 2012, annually. 5 Given the considerable health and economic impact of cancer in Canada, comprehensive and reliable surveillance information is necessary for identifying where progress has been made and where more attention and resources are needed. To meet these needs, the Canadian Cancer Statistics Advisory Committee, in collaboration with the Canadian Cancer Society, Statistics Canada and the Public Health Agency of Canada, produces the latest surveillance statistics on cancer in Canada.Cancer data often lag the current date by several years, owing to the time associated with collecting, verifying and analyzing the data. Short-term cancer incidence and mortality rates can be projected by extrapolating past trends to estimate future trends, using statistical models. These short-term projections provide a more up-to-date estimate of the cancer landscape in Canada. Incidence and mortality counts, along with age-standardized rates, provide a picture of the impact of cancer in Canada, which is essential for resource planning, research and informing cancer-control programs.Canadian Cancer Statistics 2021 3 provided detailed estimates of cancer incidence, mortality and survival in Canada by age, sex, geographic region and over time for 22 cancer types. 3 Here, we provide updated estimates of the counts and age-standardized rates of new cancer cases (incidence) and cancer deaths (mortality) expected in 2022 by sex and province and territory, for all ages combined.