A Cold-Strontium Laser in the Superradiant Crossover Regime

Recent proposals suggest that lasers based on narrow dipole-forbidden transitions in cold alkaline earth atoms could achieve linewidths that are orders of magnitude smaller than linewidths of any existing lasers. Here, we demonstrate a laser based on the 7.5 kHz linewidth dipole forbidden $^3$P$_1$ to $^1$S$_0$ transition in laser-cooled and tightly confined $^{88}$Sr. We can operate this laser in the bad-cavity regime, where coherence is primarily stored in the atoms, or continuously tune to the more conventional good-cavity regime, where coherence is primarily stored in the light field. We show that the cold-atom gain medium can be repumped to achieve quasi steady-state lasing, and demonstrate up to an order of magnitude suppression in the sensitivity of laser frequency to changes in cavity length, the primary limitation for the most frequency stable lasers today.Comment: 5 pages, 4 figure

How does a bicycle work? A new instrument to assess mechanical reasoning in school aged children

This study demonstrated that a brief interview can reveal the mechanical reasoning that could not be assessed via the Bicycle Drawing Test. This study, conducted on 190 children (6 to 11 years old), shows that mechanical reasoning improves with age. It shows correlations with spatial reasoning and motor control, and with visual reasonin

How Emotional, Economic and Material Dependency May Produce Poverty for Women

Dependencies, mainly for women, represent a factor that studies from \u2770s on have detected as originating a greater risk of social exclusion and vulnerability and, ultimately, of poverty. Main dimensions of dependency emerged from literature regard following aspects: 1) economic (income sources); 2) material (non-economic help in the management of the household from family of origin and friends); 3) emotional (need of an external emotional support). This contribution originates from a 2012 research on poverty and social exclusion, conducted in Italy by National Research Council, involving almost 1000 subjects. Three indexes have been built, referring to different dependencies detected by literature: Economic Dependency Index (EDI), Material Dependency Index (MDI) and Emotional Dependency Index (EDI). These indexes, together with other indicators, have been used with the aim of comparing female versus male respondents. Furthermore, women\u27 profiles have been drawn out that are potentially vulnerable to poverty and social exclusion (elderly women, women with precarious jobs and divorcees) more than others