Observational prospects for gravitational waves from hidden or dark chiral phase transitions

We study the gravitational wave (GW) signature of first-order chiral phase transitions ($\chi$PT) in strongly interacting hidden or dark sectors. We do so using several effective models in order to reliably capture the relevant non-perturbative dynamics. This approach allows us to explicitly calculate key quantities characterizing the $\chi$PT without having to resort to rough estimates. Most importantly, we find that the transition's inverse duration $\beta$ normalized to the Hubble parameter $H$ is at least two orders of magnitude larger than typically assumed in comparable scenarios, namely $\beta/H\gtrsim\mathcal{O}(10^4)$. The obtained GW spectra then suggest that signals from hidden $\chi$PTs occurring at around 100 MeV can be in reach of LISA, while DECIGO and BBO may detect a stochastic GW background associated with transitions between roughly 1 GeV and 10 TeV. Signatures of transitions at higher temperatures are found to be outside the range of any currently proposed experiment. Even though predictions from different effective models are qualitatively similar, we find that they may vary considerably from a quantitative point of view, which highlights the need for true first-principle calculations such as lattice simulations.Comment: 35 pages, 9 figures. Extended discussion and updated calculation of gravitational wave spectra, main results unchanged; references added; matches published versio

Quantized Friction across Ionic Liquid Thin Films

Ionic liquids, salts in the liquid state under ambient conditions, are of great interest as precision lubricants. Ionic liquids form layered structures at surfaces, yet it is not clear how this nano-structure relates to their lubrication properties. We measured the friction force between atomically smooth solid surfaces across ionic liquid films of controlled thickness in terms of the number of ion layers. Multiple friction-load regimes emerge, each corresponding to a different number of ion layers in the film. In contrast to molecular liquids, the friction coefficients differ for each layer due to their varying composition

A how-to guide for the Smith College Proxy Carbon Life Cycle Cost Calculator

Detailed written guide for using the LCC calculator for Smith College. A similar guide can be adapted for users of the calculator at your institution. The Smith College Proxy Carbon Life Cycle Cost Calculator is a tool designed to include climate impacts in the evaluation of present and future costs of projects on campus. At the request of the Study Group on Climate Change, this Excel tool was developed as part of the implementation of a proxy carbon price at Smith College

Expanding Institutional Arrangements for Acquiring Water for Environmental Purposes: Transactions Evidence for the Western United States

Market purchases of water rights for environmental purposes in the western United States have involved purchases by public agencies of at least 88 850 acre feet of water over the last five years. Annual water leasing for environmental purposes has been more active, with 1.72 million acre feet leased in the western United States. The most frequent reasons for these transactions are for wildlife (primarily waterfowl), recreation and fisheries. The average price paid for a water right is $609 per acre foot, while it is$30 per acre foot for an annual water lease. As evidenced by the ability of government agencies to purchase water in voluntary transactions, environmental uses of water are often competitive with many low-value agricultural crops in the western United States

Phytophthora pathogens threaten rare habitats and conservation plantings

Phytophthora pathogens are damaging native wildland vegetation including plants in restoration areas and botanic gardens. The infestations threaten some plants already designated as endangered and degrade high-value habitats. Pathogens are being introduced primarily via container plant nursery stock and, once established, they can spread to adjacent areas where plant species not previously exposed to pathogens may become infected. We review epidemics in California – caused by the sudden oak death pathogen Phytophthoraramorum Werres, De Cock & Man in ‘t Veld and the first USA detections of P. tentaculata Kröber & Marwitz, which occurred in native plant nurseries and restoration areas – as examples to illustrate these threats to conservation plantings

Expanding Institutional Arrangements for Acquiring Water for Environmental Purposes: Transactions Evidence for the Western United States

Market purchases of water rights for environmental purposes in the western United States have involved purchases by public agencies of at least 88 850 acre feet of water over the last five years. Annual water leasing for environmental purposes has been more active, with 1.72 million acre feet leased in the western United States. The most frequent reasons for these transactions are for wildlife (primarily waterfowl), recreation and fisheries. The average price paid for a water right is $609 per acre foot, while it is$30 per acre foot for an annual water lease. As evidenced by the ability of government agencies to purchase water in voluntary transactions, environmental uses of water are often competitive with many low-value agricultural crops in the western United States

The lesbian, gay, bisexual and transgender community online: discussions of bullying and self-disclosure in YouTube videos

Computer-mediated communication has become a popular platform for identity construction and experimentation as well as social interaction for those who identify as lesbian, gay, bisexual or transgender (LGBT). The creation of user-generated videos has allowed content creators to share experiences on LGBT topics. With bullying becoming more common amongst LGBT youth, it is important to obtain a greater understanding of this phenomenon. In our study, we report on the analysis of 151 YouTube videos which were identified as having LGBT- and bullying-related content. The analysis reveals how content creators openly disclose personal information about themselves and their experiences in a non-anonymous rhetoric with an unknown public. These disclosures could indicate a desire to seek friendship, support and provide empathy

Tendon reattachment to bone in an ovine tendon defect model of retraction using allogenic and xenogenic demineralised bone matrix incorporated with mesenchymal stem cells

BACKGROUND: Tendon-bone healing following rotator cuff repairs is mainly impaired by poor tissue quality. Demineralised bone matrix promotes healing of the tendon-bone interface but its role in the treatment of tendon tears with retraction has not been investigated. We hypothesized that cortical demineralised bone matrix used with minimally manipulated mesenchymal stem cells will result in improved function and restoration of the tendon-bone interface with no difference between xenogenic and allogenic scaffolds. MATERIALS AND METHODS: In an ovine model, the patellar tendon was detached from the tibial tuberosity and a complete distal tendon transverse defect measuring 1 cm was created. Suture anchors were used to reattach the tendon and xenogenic demineralised bone matrix + minimally manipulated mesenchymal stem cells (n = 5), or allogenic demineralised bone matrix + minimally manipulated mesenchymal stem cells (n = 5) were used to bridge the defect. Graft incorporation into the tendon and its effect on regeneration of the enthesis was assessed using histomorphometry. Force plate analysis was used to assess functional recovery. RESULTS: Compared to the xenograft, the allograft was associated with significantly higher functional weight bearing at 6 (P = 0.047), 9 (P = 0.028), and 12 weeks (P = 0.009). In the allogenic group this was accompanied by greater remodeling of the demineralised bone matrix into tendon-like tissue in the region of the defect (p = 0.015), and a more direct type of enthesis characterized by significantly more fibrocartilage (p = 0.039). No failures of tendon-bone healing were noted in either group. CONCLUSION: Demineralised bone matrix used with minimally manipulated mesenchymal stem cells promotes healing of the tendon-bone interface in an ovine model of acute tendon retraction, with superior mechanical and histological results associated with use of an allograft