Prolactin is an important endocrine activator of lactogenesis. This study investigated the function and mechanism of miR-135b in the enhancement of lactation by prolactin in goat mammary epithelial tissue. We utilized S-Poly (T) sequencing to evaluate changes in gene regulation in the goat mammary gland after incubation with 2.5 μg/ml prolactin and 2.5 μg/ml IGF-1 by examining highly expressed miRNAs during early lactation and late-lactation. The results illustrated that miR-135b is highly expressed in the goat mammary gland during early lactation and late-lactation, and also after treatment with 2.5 μg/ml prolactin and 2.5 μg/ml IGF-1. We used Q-RT PCR, Western Blot, immunofluorescence, and luciferase reporter assay analysis, and found that PRL was significantly down-regulated in response to the expression of miR-135b in a manner that was functionally related to TAG synthesis via the large tumor suppressor 2 gene (Lats2), an important regulator of adipocyte proliferation via Hippo Signaling. Furthermore, using bisulfite-sequencing PCR (BSP), Q-PCR, and Western Blot we discovered an increase in expression of DNMT I (DNA methyl transferase I) in goat mammary epithelial cells with the 2.5 μg/ml PRL incubation, which led to DNA methylation of the CpG island upstream of miR-135b and inhibited the transcription and expression of miR-135b. K E Y W O R D Sfat metabolism, LATS2, methylation, miR-135b | INTRODUCTIONMilk provides optimal nutrition for growth and development of humans. Compared with cow milk, goat milk (the milk of Capra hircus) has a higher level of unsaturated fatty acids, total fat, calcium, vitamins, carbohydrates, and proteins (Han et al., 2004;Hinrichs, 2004;Luna, Bach, Juarez, & de la Fuente, 2008;Qu, Chen, Fan, Sun, & Zeng, 2016).Prolactin (PRL) plays a key role in the process of lactation and is secreted by the hypothalamus. PRL is an important hormone for the initiation of lactation in ruminants, can stimulate mammary epithelial cell metabolism, and stimulate milk protein synthesis (Inaba et al., 2016). In non-ruminants, PRL promotes mammary development during early pregnancy by stimulation of the ovaries to produce estrogen and progesterone (Campo Verde Arbocco et al., 2016).During pregnancy, PRL concentrations in plasma are significantly elevated and it can promote the secretion of IGF 1 and enhance the activity of the PKB/AKt (protein kinase) pathway (Roman, Seres, Herichova, Zeman, & Jurcovicova, 2003; Milewicz et al., 2011;Xiong et al., 2016). In addition, PRL-PRLR complexes (PRL combined with PRLR) can enter cells and elicit physiological effects through the JAK/ STAT and PKB/AKt pathway (Akers, 2006). Numerous studies have revealed that PRL plays an indispensable role in the process of lactation. However, how PRL works at the molecular level and the related molecular mechanism remain a "black box" that requires careful research (Akers, 2006;Erb et al., 1976;Hart, Bines, Morant, & Ridley, 1978;Kazmer & Oyler, 1991 Wang et al., 2014). MiRNA regulation is precise and its expression has stri...

The shear strength prediction model for fiber-reinforced polymer (FRP) bar-reinforced concrete beams without stirrups in ACI440.1R-2015 does not consider the “size effect” and the effect of shear span-to-depth ratio and predicts the zero-shear strength for concrete members without longitudinal reinforcement. A modified shear strength prediction model for FRP bar-reinforced concrete beams without stirrups was presented in this paper. The proposed model takes into account the effect of concrete strength, size of the beam, shear span-to-depth ratio, reinforcement ratio, and modulus of elasticity of the longitudinal reinforcement and the “size effect.” The superiority of the proposed model has been evaluated by comparing the calculated shear strength of FRP bar-reinforced concrete beams without stirrups by the proposed model with the experimental results and calculated values by the models in design codes, respectively. It confirmed that the shear strength of FRP bar-reinforced concrete beams without stirrups by the proposed model was in better agreement with the experimental results.

No abstract

Based on the tests of six reinforced concrete slabs strengthened with fibre reinforced plastic (FRP) sheets and one reference slab without the sheet, the influences of factors such as type of FRP sheets (CFRP and GFRP), amount of FRP sheets and strengthening scheme upon the crack resistant performance were presented and discussed in this paper. In the end, a calculation method was put forward, which can be used to calculate cracking moment and crack width in reinforced concrete slabs strengthened with FRP sheets.