Kisspeptin, a neuropeptide and the master controller of reproductive axis upstream to GnRH neurons, and its receptor are also expressed in extrahypothalamic tissues, such as ovaries. As systemic kisspeptin has been shown to modulate follicular dynamics in cattle, we hypothesized that kisspeptin has direct actions on the ovarian follicular development. We also hypothesized that kisspeptin regulation of primordial follicle development is via modulation of VEGF expression. In order to test these hypotheses, we cultured caprine ovarian cortical strips in vitro for 7 days with supplementation of kisspeptin at 1, 10 and 100 μM concentration and observed the development of primordial follicles into intermediate, primary and secondary follicles. We also studied the alteration in the expression profile of VEGF and VEGF transcript variant 2 mRNA during follicular development in the presence of kisspeptin. We confirmed the presence of GPR54 in goat ovaries in our preliminary studies. Supplementation of kisspeptin at 1 and 10 μM concentration facilitated the development of primordial follicles into intermediate, primary and secondary follicles with less number of degenerated follicles while the same at 100 μM resulted in degeneration of follicles. We observed a drastic increase in the expression profile of VEGF and VEGF transcript variant 2 mRNA upon culture which was independent of kisspeptin treatment. In conclusion, our studies show that kisspeptin facilitates ovarian primordial development in vitro.

Kisspeptin is a key player in the central control of reproductive axis. Central administration of kisspeptin has been shown to advance puberty in rats. Stimulation of hypothalamic GnRH pulse generating mechanism by kisspeptin has been proposed to be the mechanism behind the onset of puberty. We hypothesized that chronic high doses of kisspeptin administration suppresses the reproductive axis and hence delays the pubertal onset. Hence, we investigated the effect of peripheral administration of chronic high doses of kisspeptin on pubertal onset, feed intake and body weight in female rats. Rats were treated with saline or kisspeptin (100 nmoles per day; intraperitoneal) for 26 days (day 25 to day 50 postnatal) and the day of vaginal opening was marked as day of puberty. Kisspeptin treated rats had delayed pubertal onset and reduced feed intake and body weight. Gonadal GPR54 mRNA was reduced suggesting that chronic high doses of kisspeptin may suppress the reproductive functions possibly by downregulation of GPR54 receptor. However, delay in puberty due to reduction in feed intake and body weight could not be ruled out in this study. Further, our study emphasizes the importance of dosage and duration of kisspeptin administration in the manipulation of reproductive axis. Our study, for the first time, suggests that kisspeptin and its analogues, if proven beneficial, could be used to treat precocious puberty in children. It appears that, though a promising tool for enhancing fertility, kisspeptin acts as a double-edged sword and has to be cautiously used to manipulate reproduction.

By adopting a usage-based approach to language acquisition, this study investigated the emergence and development of L2 constructional knowledge. A total of 19 English verb-argument constructions (VACs) and their associated verbs were extracted from a learner corpus and three verbal fluency tasks, each conducted in L1 and L2 English and L1 Korean. We compared verb usage in the target VACs across proficiency levels between the L1 and L2 groups and between data types for VAC productivity and verb-VAC associations. The results identified three stages through which Korean learners’ VAC knowledge develops in L2 English: emerging through the frequent use of a few general verbs, expanding the range of verbs associated with a VAC to include more specific and prototypical verb types, and then developing them into a creative constructional schema. Moreover, we determined similarities between L1 and L2 English VAC knowledge in higher L2 proficiency levels, as well as L1 Korean influences related to L1 typology and L1 collocational transfer.

Graphene is an unconventional material with a two-dimensional hexagonal crystalline array of elemental carbon atoms and outstanding properties; accordingly, a desirable objective in the line of research of graphene is the development of novel and more productive methods of synthesis, validating its properties and applications. In our exploratory research, we have effectively exfoliated graphene from graphite using supercritical fluids (water, ethanol and carbon dioxide). The exfoliated graphene was properly characterized; via scanning electron microscopy, the morphology of graphene was observed; Raman spectra confirmed the exfoliation of graphene depicting the characteristic shift towards smaller Raman number in the 2D band (2676 cm−1) compared to that of graphite (≈ 2700 cm−1); transmission electron microscopy analysis exhibited the crystalline structure of graphene attesting also the expected transparency of exfoliated layers. Graphene exfoliation from graphite by supercritical fluids promises to be a simple large-scale method for graphene production.

Background/Aim: Endoscopic retrograde cholangiopancreatography (ERCP) training requires varying degrees of staff assistance regarding operation of the fluoroscopy machine via a foot pedal. Efficiency is important to acquire during this training due to radiation risks. In this study, we evaluate the effect of controlling endoscopy and fluoroscopy unit on duct cannulation rates (CRs) and total fluoroscopy time (FT) for fellows in training. Methods: 204 patients undergoing ERCP were randomized to one of two groups: 1) “Endoscopist Driven” group in which the endoscopist controlled the foot pedal for fluoroscopy, and 2) “Assistant Driven” group in which attending or fellow controlled the foot pedal while the other team member controlled the endoscope. Various measures including selective duct CR and total FT were recorded. Results: There was no significant difference in mean procedure duration between the two groups (32 minutes vs. 33 minutes, p=0.70). There was also no statistically significant difference in CR (83.7% vs. 77.4%, p=0.25) or FT (3.27 minutes vs. 3.54 minutes, p=0.48). Conclusions: ERCP is a technically challenging procedure which requires extensive supervision. This study demonstrates that CR and FT are not affected by who controls the fluoroscopy.

We report the discovery of a giant exoplanet in the microlensing event OGLE-2017-BLG-1049, with a planet―host star mass ratio of q = 9.53 ± 0.39 × 10-3 and a caustic crossing feature in Korea Microlensing Telescope Network (KMTNet) observations. The caustic crossing feature yields an angular Einstein radius of θE = 0.52 ± 0.11 mas. However, the microlens parallax is not measured because the time scale of the event, tE ≃ 29 days, is too short. Thus, we perform a Bayesian analysis to estimate physical quantities of the lens system. We find that the lens system has a star with mass Mh = 0.55+0.36 -0.29 M⊙ hosting a giant planet with Mp = 5.53+3.62 -2.87 MJup, at a distance of DL = 5.67+1.11 -1.52 kpc. The projected star{planet separation is aㅗ = 3.92+1.10 -1.32 au. This means that the planet is located beyond the snow line of the host. The relative lens{source proper motion is μrel ~ 7 mas yr-1, thus the lens and source will be separated from each other within 10 years. After this, it will be possible to measure the flux of the host star with 30 meter class telescopes and to determine its mass.

A combination of Polycarbonate (PC) material and Polymethylmethacrylate (PMMA), fabricated using an injection molding machine, has been investigated to determine its advantages, as studied in Ref. 1). This paper aims to investigate the optimization of PMMA/PC blend for both tensile yield strength and impact strength. Furthermore, interaction effects of process conditions on mechanical properties including tensile yield strength and impact strength of PMMA/PC blend by injection molding process are interpreted in this study. Tensile and impact specimens are designed following ASTM, type V, and are fabricated by injection molding process. The processing conditions such as melt temperature, mold temperature, packing pressure, and cooling time are applied; each factor has three levels. As a result, in comparison with optimization of separated responses, mechanical properties of PMMA/PC are found to decrease when optimizing both tensile and impact strengths simultaneously. The melt temperature is found to be the most significant interaction parameter with the mold temperature and packing pressure. In addition, there is more interaction between the mold temperature and cooling time. This investigation provides a useful understanding of the control of injection molding processing of polymer blends in optical application.

We investigated the cytotoxic potential of three different commercially available absorbent feminine hygiene products and one transdermal patch using direct contact and extract exposure methods. Two different cell lines were used – mouse fibroblast L929 and normal human skin fibroblast CCD-986sk cell lines. The test samples were extracted using three different methods in accordance to International Organization for Standardization (ISO). Viability of cells was analyzed using MTT assay and morphology of the cells were also observed using phase contrast microscopy. Overall, the direct contact method using L929 cells showed that all the test samples had no toxic effect when exposed to extracts for 1 h. For the exposure method, no toxic effect was observed in both L929 and CCD986sk cells incubated with all the test samples regardless of the extraction methods used.

This research aims to assess the current status of online trade relations between Kuwait and Portugal. To do so, we examine how firm managers from Portugal and Kuwait use online platforms to engage customers to enhance firm performance. A set of existing constructs was chosen (Online Experience, Customer Inspiration, Online Customer Engagement, Firm Performance, National Culture), which were included in a proposed model of structural equations, in order to assess the contribution of Online Experience and Customer inspiration to the current status of online trade relations (through Online Customer Engagement), and how these can be improved to the further development of e-commerce between the two countries.

This paper analyses the determinants of schoolchildren’s food preferences, paying attention to the relative importance of child/parent, school and locality factors, using multilevel modelling. Urbanisation, location in a poorer neighbourhood, having a school lunch and some specific parental practices positively affect the range of foods and vegetables liked by children.

This research seeks to unveil how YouTube influencers and digital interaction can contribute to the process of customer-brand relationship and engagement. Based on in-depth interviews of female Youtubers devoted to the lifestyle categories, we aim to comprehend the engagement factors that influencers should rely on to promote engagement between their followers and the brands they advocate.

The study builds and tests a framework investigating the determinants of customer engagement with luxury brands on social media platforms.