Drought Tolerance Dissection and Molecular Breeding in Alfalfa

Drought stress is one of the leading impediments that limit the productivity of global alfalfa (Medicago sativa). The underlying molecular and genetic mechanisms for drought tolerance in alfalfa remain largely unclear. In order to fully reveal the transcriptional changes of alfalfa in response to abiotic stress, the alfalfa transcriptome database under mannitol (simulated drought stress), NaCl (simulated salt stress), or exogenous ABA application was built via various RNA-seq technologies. Through further screening of the transcriptome database, a number of genes significantly induced by drought stress, such as the Nuclear Transport Factor 2-like (MsNTF2L), Drought-Induced Unknown Protein 1 (MsDIUP1), and MsNST1, were identified. These three genes were transferred into alfalfa by overexpression and RNAi techniques, and their physiological characteristics and transcriptional level response were synthetically studied. Alfalfa MsNTF2L-OE plants have been approved by the Ministry of Agriculture of China to carry out the field test in Gansu Province. Furthermore, we constructed a GWAS population and obtained 50 excellent plants with strong drought tolerance and high hay-yield. These studies provide a theoretical foundation for drought-tolerant molecular breeding of alfalfa

Constraining Palatini-Horndeski theory with gravitational waves after GW170817

In this paper, we investigate the possible parameter space of Palatini-Horndeski theory with gravitational waves in a spatially flat Universe. We find that if the theory satisfies the following condition: in any spatially flat cosmological background, the tensor gravitational wave speed is the speed of light $c$, then only $S = \int d^4x \sqrt{-g} \big[K(\phi,X)-G_{3}(\phi,X){\tilde{\Box}}\phi+G_{4}(\phi)\tilde{R}\big]$ is left as the possible action in Palatini-Horndeski theory.Comment: 23 pages, no figur

The Impact of Sharing Economy on Local Employment: Evidence from Airbnb

A growing literature has documented the impact of home sharing. We study a new externality in which local people can enjoy more job opportunities because of the entry of home sharing. Using data from Airbnb and employing a quasi-experimental design, we find the following evidences. We find that home sharing provides more employment options to locals especially for lesseducation and low-income population. As home sharing becomes an incentive for local employment, our study provides important understanding of home sharing and its implications to local welfare, Airbnb hosts, and policy makers