The neutral silicon-vacancy center in diamond: spin polarization and lifetimes

We demonstrate optical spin polarization of the neutrally-charged silicon-vacancy defect in diamond ($\mathrm{SiV^{0}}$), an $S=1$ defect which emits with a zero-phonon line at 946 nm. The spin polarization is found to be most efficient under resonant excitation, but non-zero at below-resonant energies. We measure an ensemble spin coherence time $T_2>100~\mathrm{\mu s}$ at low-temperature, and a spin relaxation limit of $T_1>25~\mathrm{s}$. Optical spin state initialization around 946 nm allows independent initialization of $\mathrm{SiV^{0}}$ and $\mathrm{NV^{-}}$ within the same optically-addressed volume, and $\mathrm{SiV^{0}}$ emits within the telecoms downconversion band to 1550 nm: when combined with its high Debye-Waller factor, our initial results suggest that $\mathrm{SiV^{0}}$ is a promising candidate for a long-range quantum communication technology

Neutral Silicon-Vacancy Center in Diamond: Spin Polarization and Lifetimes

We demonstrate optical spin polarization of the neutrally charged silicon-vacancy defect in diamond (SiV0), an S ¼ 1 defect which emits with a zero-phonon line at 946 nm. The spin polarization is found to be most efficient under resonant excitation, but nonzero at below-resonant energies. We measure an ensemble spin coherence time T2 > 100 μs at low-temperature, and a spin relaxation limit of T1 > 25 s. Optical spin-state initialization around 946 nm allows independent initialization of SiV0 and NV− within the same optically addressed volume, and SiV0 emits within the telecoms down-conversion band to 1550 nm: when combined with its high Debye-Waller factor, our initial results suggest that SiV0 is a promising candidate for a long-range quantum communication technology

Home media and science performance:A cross-national study

This study examines the effects of media resources in the parental home on the science performance of 15-year-old students. It employs data from the 2006 Programme for International Student Assessment (PISA) containing information on 345,967 respondents from 53 countries. Results show that media assets in the family home are indeed meaningful for children’s science performance, as a beneficial resource but also as a disadvantage. A positive reading climate in the parental home and the availability of computers benefits science performance. However, a television-rich home seems to hinder children’s school success. Furthermore, results indicate that, compared to less developed countries, in more modernized societies parental reading investments are even more beneficial to their children’s science performance, whereas a television-rich parental home is even more disadvantageous

Interactions between Natural Populations of Human and Rodent Schistosomes in the Lake Victoria Region of Kenya: A Molecular Epidemiological Approach

One of the world's most prevalent neglected diseases is schistosomiasis, which infects approximately 200 million people worldwide. Schistosoma mansoni is transmitted to humans by skin penetration by free-living larvae that develop in freshwater snails. The origin of this species is East Africa, where it coexists with its sister species, S. rodhaini. Interactions between these species potentially influence their epidemiology, ecology, and evolutionary biology, because they infect the same species of hosts and can hybridize. Over two years, we examined their distribution in Kenya to determine their degree of overlap geographically, within snail hosts, and in the water column as infective stages. Both species were spatially and temporally patchy, although S. mansoni was eight times more common than S. rodhaini. Both species overlap in the time of day they were present in the water column, which increases the potential for the species to coinfect the same host and interbreed. Peak infective time for S. mansoni was midday and dawn and dusk for S. rodhaini. Three snails were coinfected, which was more common than expected by chance. These findings indicate a lack of obvious isolating mechanisms to prevent hybridization, raising the intriguing question of how the two species retain separate identities

Theorieën omtrent het ontstaan van wanen bij schizofrene psychose

status: publishe

Young people and music television in the Netherlands

When on 1 May 1995 TMF (The Music Factory) started off as the first local popular music television station on Dutch cable, it tried right away to compete with MTV. This article, based upon a telephone survey among a national sample of 400 people, shows ample evidence that people not only watch TMF more frequently than MTV, but that on average they like TMF a lot more. Moreover, TMF seems to be better able to fulfil the music needs of Dutch teenage viewers. TMF programming fits the youth subcultures of the 'gabbers' and the hip-hoppers. The subcultures that are best served by MTV are those whose members like rock music: punk, alto, metal and skater. Hence the subcultures which TMF serves are much larger in number than MTV's. Therefore it seems that TMF has been able to adjust better to local conditions and that its programming is better suited to the local target groups than MTV's.status: publishe

De cognitieve beperkingen van schizofrene patienten, een duurzaam kenmerk van hun aandoening

status: publishe

Auditieve hallucinaties bij schizofrene patiënten

status: publishe