Signatures of Self-Interacting Dark Matter in the Matter Power Spectrum and the CMB

We consider a self-interacting dark matter model in which the massive dark photon mediating the self-interaction decays to light dark fermions to avoid over-closing the universe. We find that if the model is constrained to explain the dark matter halos inferred for spiral galaxies and galaxy clusters simultaneously, there is a strong indication that dark matter is produced asymmetrically in the early universe. It also implies the presence of dark radiation, late kinetic decoupling for dark matter, and a suppressed linear power spectrum due to dark acoustic damping. The Lyman-$\alpha$ forest power spectrum measurements put a strong upper limit on the damping scale and the model has little room to reduce the abundances of satellite galaxies. Future observations in the matter power spectrum and the CMB, in tandem with the impact of self-interactions in galactic halos, makes it possible to measure the gauge coupling and masses of the dark sector particles even when signals in conventional dark matter searches are absent.Comment: 5 pages, 7 figures, published version in PL

How Green Public Procurement Contributes to Sustainable Development in China: Evidence from the IISD Green Public Procurement Model

The People's Republic of China spent more than CNY 1.6 trillion (USD 252 billion) on procurement in 2013, accounting for 11.7 per cent of all national spending (Ministry of Finance of the People's Republic of China, 2014). In light of these numbers, the potential environmental, social and economic multipliers of greening government purchases become evident. The benefits of a comprehensive and efficient green public procurement (GPP) policy are not limited to the green products and services the public sector buys, but will have a ripple effect that encourages green consumption nationwide. The significant purchasing power of the government will provide the much-needed incentives in order for businesses to invest and innovate in green products and services to meet the government's guaranteed long-term and high-volume demand. Additionally, GPP is in line with China's national plans to pioneer "eco-civilisation" and with the upcoming 13th Five-Year Plan (FYP), which underlines the importance of GPP.This paper is the second and final component of IISD's contribution to greening public procurement in China. Our discussion paper Green Public Procurement in China: Quantifying the Benefits, published in April 2015, analyzed China's GPP landscape, taking a closer look at current practices, actors at different levels of government and the underlying legal framework. In addition, the paper introduced the IISD GPP Model, discussing its potential for quantifying and communicating the benefits of GPP, while providing a high-level overview of the modelling approach used and of the scope of the model envisioned. Building on the results of the IISD GPP Model, consultations with stakeholders and an extensive literature review, this paper provides targeted recommendations addressing the development areas identified to improve GPP in China. The recommendations follow a multiphase approach offering more immediate solutions as well as more ambitious, larger-scale overhauls of the GPP framework for the long term. The results of the IISD GPP Model will be shared for the first time as part of this paper, making the case for green procurement through analyzing five product categories: air conditioners, lighting, cars, paper and cement. These categories were selected because they represent significant financial flows in procurement, have notable environmental impacts and domestic production, and have sufficient data available to facilitate their analysis. A detailed overview of the key elements of the modelling approach will be provided, in addition to an explanation of the model setup and the range of externalities monetised for each product category. Finally, we will look at how to use the model at the different levels of government as well as how its scope can be extended and customised in order to leverage its potential under a wider range of circumstances and areas of procurement

Cerebellar nuclei neurons show only small excitatory responses to optogenetic olivary stimulation in transgenic mice: in vivo and in vitro studies

BACKGROUND: To study the olivary input to the cerebellar nuclei (CN) we used optogenetic stimulation in transgenic mice expressing channelrhodopsin-2 (ChR2) in olivary neurons. We obtained in vivo extracellular Purkinje cell (PC) and CN recordings in anesthetized mice while stimulating the contralateral inferior olive (IO) with a blue laser (single pulse, 10 - 50 ms duration). Peri-stimulus histograms were constructed to show the spike rate changes after optical stimulation. Among 29 CN neurons recorded, 15 showed a decrease in spike rate of variable strength and duration, and only 1 showed a transient spiking response. These results suggest that direct olivary input to CN neurons is usually overridden by stronger Purkinje cell inhibition triggered by climbing fiber responses. To further investigate the direct input from the climbing fiber collaterals we also conducted whole cell recordings in brain slices, where we used local stimulation with blue light. Due to the expression of ChR2 in Purkinje cell axons as well as the IO in our transgenic line, strong inhibitory responses could be readily triggered with optical stimulation (13 of 15 neurons). After blocking this inhibition with GABAzine, only in 5 of 13 CN neurons weak excitatory responses were revealed. Therefore our in vitro results support the in vivo findings that the excitatory input to CN neurons from climbing fiber collaterals in adult mice is masked by the inhibition under normal conditions

Design and fabrication of robust broadband extreme ultraviolet multilayers

The random layer thickness variations can induce a great deformation of the experimental reflection of broadband extreme ultraviolet multilayer. In order to reduce this influence of random layer thickness fluctuations, the multiobjective genetic algorithm has been improved and used in the robust design of multilayer with a broad angular bandpass. The robust multilayer with a lower sensitivity to random thickness errors have been obtained and the corresponding multilayer mirrors were fabricated. The experimental results of robust Mo/Si multilayer with a wide angular band were presented and analyzed, and the advantage of robust multilayer design was demonstrated

The First Study of Mating Mistakes in Stoneflies (Plecoptera) from China, with Remarks on Their Biological Implications

Currently, information on the biology of Plecoptera from China is scarce, particularly on mating behavior. In this paper, the existence of mating mistakes (erroneous mating attempts) involving 13 Chinese stonefly species (belonging to nine genera and three families) is reported. These erroneous mating behaviors can be included into three different categories: mating attempts between conspecific males (including the formation of erroneous mating balls), mating attempts between different taxa (including displacement attempts during copulation), and mating-related behaviors with non-living objects. From these behaviors, some aspects of stoneflies during mating, such as the physical competition between males, the sensorial mechanisms implied in triggering a mating behavior, the conditions favoring the mating mistakes, and the possible consequences of interspecific mating in the hybrid production, are discussed.National Natural Science Foundation of China (No. 32170459; 31872266; 31071958)China Scholarship Council, the Project of Biological Resources Survey in Wuyishan National Park, Investigation and Evaluation of Insect Resources in Huangshan Scenic Spot (Phase I)Insect fauna of Qilian Mountain National Park (Qinghai)Volume of Lepidoptera and Diptera (procurement contract No. QHTX-2021-006, Administration of Qilian Mountain Nature Reserve, Qinghai Province

Sample Imbalance Adjustment and Similar Object Exclusion in Underwater Object Tracking

Although modern trackers exhibit competitive performance for underwater image degradation assessment, two problems remain when these are applied to underwater object tracking (UOT). A single-object tracker is trained on open-air datasets, which results in a serious sample imbalance between underwater objects and open-air objects when it is applied to UOT. Moreover, underwater targets such as fish and dolphins usually have a similar appearance, and it is challenging for models to discriminate weak discriminative features. Existing detection-based post-processing approaches struggle to distinguish a tracked target from similar objects. In this study, the UOSTrack is proposed, which involves the use of underwater images and open-air sequence hybrid training (UOHT), and motion-based post-processing (MBPP). The UOHT training paradigm is designed to train the sample-imbalanced underwater tracker. In particular, underwater object detection (UOD) images are converted into image pairs through customised data augmentation, such that the tracker is exposed to more underwater domain training samples and learns the feature expressions of underwater objects. The MBPP paradigm is proposed to exclude similar objects near the target. In particular, it employs the estimation box predicted using a Kalman filter and the candidate boxes in each frame to reconfirm the tracked target that is hidden in the candidate area when it has been lost. UOSTrack provides an average performance improvement of 3.5 % compared to OSTrack on similar object challenge attribute in UOT100 and UTB180. The average performance improvements provided by UOSTrack are 1 % and 3 %, respectively. The results from two UOT benchmarks demonstrate that UOSTrack sets a new state-of-the-art benchmark, and the effectiveness of UOHT and MBPP, and the generalisation and applicability of the MBPP for use in UOT