Strong CMB Constraint On P-Wave Annihilating Dark Matter

We consider a dark sector consisting of dark matter that is a Dirac fermion and a scalar mediator. This model has been extensively studied in the past. If the scalar couples to the dark matter in a parity conserving manner then dark matter annihilation to two mediators is dominated by the P-wave channel and hence is suppressed at very low momentum. The indirect detection constraint from the anisotropy of the Cosmic Microwave Background is usually thought to be absent in the model because of this suppression. In this letter we show that dark matter annihilation to bound states occurs through the S-wave and hence there is a constraint on the parameter space of the model from the Cosmic Microwave Background.Comment: 5 pages, 3 figure

Strong CMB Constraint On P-Wave Annihilating Dark Matter

We consider a dark sector consisting of dark matter that is a Dirac fermion and a scalar mediator. This model has been extensively studied in the past. If the scalar couples to the dark matter in a parity conserving manner then dark matter annihilation to two mediators is dominated by the P-wave channel and hence is suppressed at very low momentum. The indirect detection constraint from the anisotropy of the Cosmic Microwave Background is usually thought to be absent in the model because of this suppression. In this letter we show that dark matter annihilation via bound state formation occurs through the S-wave and hence there is a constraint on the parameter space of the model from the Cosmic Microwave Background

Effects of Bound States on Dark Matter Annihilation

We study the impact of bound state formation on dark matter annihilation rates in models where dark matter interacts via a light mediator, the dark photon. We derive the general cross section for radiative capture into all possible bound states, and point out its nontrivial dependence on the dark matter velocity and the dark photon mass. For indirect detection, our result shows that dark matter annihilation inside bound states can play an important role in enhancing signal rates over the rate for direct dark matter annihilation with Sommerfeld enhancement. The effects are strongest for large dark gauge coupling and when the dark photon mass is smaller than the typical momentum of dark matter in the Galaxy. As an example, we show that for thermal dark matter the Fermi gamma ray constraint is substantially increased once bound state effects are taken into account. We also find that bound state effects are not important for dark matter annihilation during the freeze-out and recombination epochs

Strong CMB Constraint On P-Wave Annihilating Dark Matter

We consider a dark sector consisting of dark matter that is a Dirac fermion and a scalar mediator. This model has been extensively studied in the past. If the scalar couples to the dark matter in a parity conserving manner then dark matter annihilation to two mediators is dominated by the P-wave channel and hence is suppressed at very low momentum. The indirect detection constraint from the anisotropy of the Cosmic Microwave Background is usually thought to be absent in the model because of this suppression. In this letter we show that dark matter annihilation via bound state formation occurs through the S-wave and hence there is a constraint on the parameter space of the model from the Cosmic Microwave Background

Assessing Patient Experience and Orientation in the Emergency Department with Virtual Windows

Patients have benefitted from increasingly sophisticated diagnostic and therapeutic innovations over the years. However, the design of the physical hospital environment has garnered less attention. This may negatively impact a patient’s experience and health. In areas of the hospital, such as the emergency department (ED), patients may spend hours, or even days, in a windowless environment. Studies have highlighted the importance of natural light and imagery, as they are essential in providing important stimuli to regulate circadian rhythm and orientation, and to mitigate the onset of certain medical conditions. In hospital locations where standard windows may be infeasible, the use of a virtual window may simulate the benefits of an actual window. In this pilot study, we assessed patient experience and orientation with virtual windows in the ED. We demonstrated that virtual windows are an acceptable technology that may improve patient experience and orientation

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Ecological Afforestation in China: A Market-based Approach

This article focuses on the program of Ecological Afforestation on barren lands, degraded arable lands, harvested sites and sloped farmland in Sichuan, China. Farmers were given the opportunity to propose afforestation activities for which they would be paid an specified amount. These bids and predictions of the expected environmental benefits to be generated were used to assess the net benefit of each proposal. Most features of the bidding scheme were successfully implemented and improvements in the economic efficiency of the afforestation scheme were observed. The market-based approach is demonstrated to be a practical way forward for Ecological Afforestation in China. The bidding scheme showed savings of approximately 110,000 Yuan when compared to past grant based programs. However, the bidding scheme is shown to increase the transaction costs of achieving the policy goal, by about 30 per cent compared to the previous ‘command and control’ regime. When transaction costs are accounted for there are still cost savings when compared to the command and control approach. Finding effective methods to reduce transaction costs will be key to any future implementation of the Ecological Afforestation bidding scheme