Magnetometer suitable for Earth field measurement based on transient atomic response

We describe the development of a simple atomic magnetometer using $^{87}$Rb vapor suitable for Earth magnetic field monitoring. The magnetometer is based on time-domain determination of the transient precession frequency of the atomic alignment around the measured field. A sensitivity of 1.5 nT/$\sqrt{Hz}$ is demonstrated on the measurement of the Earth magnetic field in the laboratory. We discuss the different parameters determining the magnetometer precision and accuracy and predict a sensitivity of 30 pT/$\sqrt{Hz}$Comment: 6 pages, 5 figure

Polarization squeezing of light by single passage through an atomic vapor

We have studied relative-intensity fluctuations for a variable set of orthogonal elliptic polarization components of a linearly polarized laser beam traversing a resonant $^{87}$Rb vapor cell. Significant polarization squeezing at the threshold level (-3dB) required for the implementation of several continuous variables quantum protocols was observed. The extreme simplicity of the setup, based on standard polarization components, makes it particularly convenient for quantum information applications.Comment: Revised version. Minor changes. four pages, three figure

Universal dissipation scaling for non-equilibrium turbulence

It is experimentally shown that the non-classical high Reynolds number energy dissipation behaviour, $C_{\epsilon} \equiv \epsilon L/u^3 = f(Re_M)/Re_L$, observed during the decay of fractal square grid-generated turbulence is also manifested in decaying turbulence originating from various regular grids. For sufficiently high values of the global Reynolds numbers $Re_M$, $f(Re_M)\sim Re_M$.Comment: 5 pages, 6 figure

Pediatric Stroke: A Review

Stroke is relatively rare in children, but can lead to significant morbidity and mortality. Understanding that children with strokes present differently than adults and often present with unique risk factors will optimize outcomes in children. Despite an increased incidence of pediatric stroke, there is often a delay in diagnosis, and cases may still remain under- or misdiagnosed. Clinical presentation will vary based on the child's age, and children will have risk factors for stroke that are less common than in adults. Management strategies in children are extrapolated primarily from adult studies, but with different considerations regarding short-term anticoagulation and guarded recommendations regarding thrombolytics. Although most recommendations for management are extrapolated from adult populations, they still remain useful, in conjunction with pediatric-specific considerations

On-chip integrated silicon bulk-micromachined soil moisture sensor with electronics and bus interface

This paper presents an on-chip silicon bulkmicromachined Soil Moisture Sensor (SMS) for irrigation control in greenhouses. The system-on-a-chip includes the SMS, readout electronics, self-test, calibration facilities and a digital bus interface for external data transmission. Moreover, this low-cost device can be applied in several locations (e. g. per each plant root), and networked together with the 1-wire bus. The heat-pulse technique is used (for measuring the maximum temperature on a distant point) to determine the volumetric heat capacity and hence the water content of a porous media, such as soil. In order to validate this method, experimental results were achieved with a macrosensor based on the heat-pulse and capacitance methods. The capacitance method relates the volumetric water content with the capacitance change (dielectric properties) of a probe, inserted in the soil. Several tests were performed for different type of soils and water contents. These results are compared with the measurements achieved using the conventional thermogravimetric method

Firm exit during economic slowdowns: does foreign ownership matter?

Do multinationals’ activities contribute to the severity of global economic crisis by quickly closing down facilities or otherwise allow to mitigating some of the worst effects, by remaining rooted in the local economy and thus reducing lay-offs and output contraction in the host countries? The present paper provides an empirical analysis on the link between foreign ownership and firm survival over an almost 20-year period and during two economic downturns in particular, using an extensive firm-level database and applying hazard models. We analyse the determinants of exit of firms and investigate whether there are significant differences in the hazard rates of foreign and domestic firms when controlling for firm and industry specificities. Additionally we assess whether the foreignness effect alters during economic downturns and whether any spillovers arise from the multinationals’ presence in the industry. After controlling for several firm and industry specific characteristics, we find that foreign firms exhibit higher failure rates over the time period as a whole. However, during economic slowdowns domestic and foreign firms do not exhibit different chances of survival and exit. Finally, regarding potential spillovers, our results suggest that foreign presence may impact positively upon local firms’ survival