Phase Stable RF-over-fiber Transmission using Heterodyne Interferometry

New scientific applications require phase-stabilized RF distribution to multiple remote locations. These include phased-array radio telescopes and short pulse free electron lasers. RF modulated onto a CW optical carrier and transmitted via fiber is capable of low noise, but commercially available systems aren't long term stable enough for these applications. Typical requirements are for less than 50fs long term temporal stability between receivers, which is 0.05 degrees at 3GHz. Good results have been demonstrated for RF distribution schemes based on transmission of short pulses, but these require specialized free-space optics and high stability mechanical infrastructure. We report a method which uses only standard telecom optical and RF components, and achieves less than 20fs RMS error over 300m of standard single-mode fiber. We demonstrate stable transmission of 3GHz over 300m of fiber with less than 0.017 degree (17fs) RMS phase error. An interferometer measures optical phase delay, providing information to a feed-forward correction of RF phase

Developing LGBT+ Inclusive Supporter Groups in the Big Bash League

Sport is an integral part of both Australian culture and identity. However, the lesbian, gay, bisexual and transgender communities (LGBT+) face extra barriers and challenges to engagement and participation in sport. This study, formed through a partnership between Western Sydney University and Cricket Victoria, aimed to better understand how LGBT+ supporter/ coterie groups could be initiated and supported in the Big Bash League. Twenty-Four key stakeholders and informants drawn from Australian Football League (AFL) LGBT+ supporter groups, AFL administrators, cricket administrators, and LGBT+ cricket fans were interviewed to collect comprehensive data on the requirements for successful LGBT+ supporter group formation in cricket and the Big Bash League. Our results reveal a strong desire to include more LGBT+ communities in cricket, with the Big Bash League identified as an ideal opportunity due to its family-oriented nature. However, it was felt by participants that there was a lack of understanding and education of LGBT+-related issues within the cricket community. The experiences of those involved in AFL support groups have been overwhelmingly positive and provide a compelling case for the introduction of LGBT+ supporter groups in cricket, from both a social inclusion and financial management perspective. We conclude that the introduction of LGBT+ supporter groups in cricket has the potential to impact positively the lives of LGBT+ communities, providing a platform for them to engage with sport in a meaningful and positive way. Three key messages were identified for those wishing to set up LGBT+ supporter groups: 1. Groups should be developed from the bottom up, being driven by LGBT+ fans and members rather than purely from the organisation. A partnership approach between Cricket Victoria/Big Bash League clubs and local LGBT+ communities also provides an avenue to facilitate training and education on LGBT+-related issues for staff and players. 2. Institutional support is crucial for such an initiative to succeed; 3. Clear policies are needed to support supporter groups and to address any negative responses. This policy should also address behaviour by players and staff to ensure that the institutional commitment to inclusion is not undermined

Intensive Rotational Grazing Systems for Dairying in a Subtropical Environment: Animal, Plant, and Soil Responses

Forage species, stocking rate, and supplementation rate effects upon performance of lactating dairy cows were studied. Forage mass and nutritive value and nutrient concentration in shallow groundwater also were measured. Cows (n = 44) grazed bermudagrass (Cynodon dactylon) or rhizoma peanut (Arachis glabrata), stocked at 4.9 or 7.4 cows ha-1, and 2.5 or 4.9 cows ha-1, respectively. Pelleted concentrate:whole cottonseed (80:20) was offered twice daily post milking at 1 kg per 2 or 3 kg of daily milk production. Cows grazing rhizoma peanut produced more (P = .076) milk per day but had greater (P = .028) loss of body condition. Higher stocking rates caused greater (P \u3e .070) weight loss. Greater supplementation increased (P \u3c .05) production of milk, fat and protein, but also increased (P \u3c .044) weight and body condition losses. Higher stocking rates and lower supplementation reduced pasture (P \u3c .001) herbage mass. Rhizoma peanut herbage was higher in nutritive value than bermudagrass. Nutrient concentrations in shallow groundwater were not affected by treatments. Use of pasture for lactating cows has potential in Florida, but low milk production and loss of body condition during summer pose management challenges

Analysis of the crystal structures of 1,3-di-tert-butyl-2,3-dihydro-1H-1,3,2-diazasilol-2-ylidene and 1,3-di-tert-butyl-2,2-dichloro-1,3-diaza-2-sila-4-cyclopentene

The crystal structures of the title compounds, 1,3-di-tert-butyl-2,3-dihydro-1H-1,3,2-diazasilol-2-ylidene, C 10 H 20 N 2 Si (1) and 1,3-di-tert-butyl-2,2-dichloro-1,3-diaza-2-sila-4-cyclopentene, C 10 H 20 N 2 SiCl 2 (3) were solved and are reported. Compound (1) crystallized in space group P mmn and each molecule has a mirror plane, which bisects the C-C backbone of the N-C-C-N framework. Compound (1) was also found to have a 2-fold twin component. In compound (3) the space group P 2 1 /m results with the mirror plane passing through the N-C-C-N backbone. We compare these structures with the gas phase determination previously reported for (1) and the incomplete single crystal data for (3)