High energy behaviour and supersymmetry

Imperial Users onl

Insulin-like factor 3 and the HPG axis in the male

The hypothalamic–pituitary–gonadal (HPG) axis comprises pulsatile GnRH from the hypothalamus impacting on the anterior pituitary to induce expression and release of both LH and FSH into the circulation. These in turn stimulate receptors on testicular Leydig and Sertoli cells, respectively, to promote steroidogenesis and spermatogenesis. Both Leydig and Sertoli cells exhibit negative feedback to the pituitary and/or hypothalamus via their products testosterone and inhibin B, respectively, thereby allowing tight regulation of the HPG axis. In particular, LH exerts both acute control on Leydig cells by influencing steroidogenic enzyme activity, as well as chronic control by impacting on Leydig cell differentiation and gene expression. Insulin-like peptide 3 (INSL3) represents an additional and different endpoint of the HPG axis. This Leydig cell hormone interacts with specific receptors, called RXFP2, on Leydig cells themselves to modulate steroidogenesis, and on male germ cells, probably to synergize with androgen-dependent Sertoli cell products to support spermatogenesis. Unlike testosterone, INSL3 is not acutely regulated by the HPG axis, but is a constitutive product of Leydig cells, which reflects their number and/or differentiation status and their ability therefore to produce various factors including steroids, together this is referred to as Leydig cell functional capacity. Because INSL3 is not subject to the acute episodic fluctuations inherent in the HPG axis itself, it serves as an excellent marker for Leydig cell differentiation and functional capacity, as in puberty, or in monitoring the treatment of hypogonadal patients, and at the same time buffering the HPG output

Observation of the Josephson effect in Pb/(Ba,K)Fe2As2 single crystal junctions

We have fabricated c-axis Josephson junctions on single crystals of (Ba,K)Fe2As2 by using Pb as the counter electrode in two geometries, planar and point contact. Junctions in both geometries show resistively shunted junction I-V curves below the Tc of the counter electrode. Microwave induced steps were observed in the I-V curves, and the critical currents are suppressed with an in-plane magnetic field in a manner consistent with the small junction limit. ICRN products of up to 0.3 mV have been observed in these junctions at 4.2 K. The observation of Josephson coupling along the c-axis between (Ba,K)Fe2As2 and a conventional superconductor suggests the existence of a s-wave superconducting order parameter in this class of iron pnictide superconductors.Comment: 16 pages and 3 figure

DAMPENING STATUS INFLUENCE USING A GROUP SUPPORT SYSTEM: AN EMPIRICAL STUDY

This study investigates the effects of a GSS and task type on status influence in a group decision making setting. Three support levels were examined: manual support. face-to-face GSS support, and dispersed GSS support. Intellective and preference tasks were studied. The dependent variables were status influence, sustained influence, and residual disagreement. Status influence and sustained influence were higher but residual disagreement was lower in manual groups than in face-to-face GSS groups and dispersed GSS groups. Preference task groups also experienced higher status influence, higher sustained influence, and lower residual disagreement compared to intelle(live task groups. These findings suggest that a GSS dampens status influence and sustained influence, though at the expense of creating greater residual disagreement, especially for a preference task

Consumers\u27 Repurchase Probability in Online Marketplace: A Belief Updating Perspective

It is commonly recognized that online transactions are “one-shot” transactions. However, a contemporary dataset from a dominant online marketplace in China reveals that averagely 24.3% transactions are repurchase transactions. Given that consumers already have purchase experience with a specific seller, their repurchase behavior may be influenced by both the seller’s reputation and their perceived seller performance. A consequent research question is: Whether and how do these two streams of information jointly affect consumers’ repurchase behavior? We adopt a belief update model, and also collect actual transaction data to examine this research question. Our findings include: (1) both seller reputation and consumers’ perceived seller performance have positive effects on consumers’ repurchase probability; (2) the effect of seller reputation is positively moderated by performance ambiguity; (3) consumers’ perceived seller performance has stronger effects on their repurchase probability when the seller has low reputation (vs. high reputation)

Effects of Antibiotics and Floor Types on Weaned Pig Performance

Proper environment for young pigs after early weaning and the most desirable floor type for maximum performance of the young pig have not been established . The effectiveness of antibiotics under ideal conditions has been the subject of considerable discussion. The relationship between floor type and pig response to antibiotics at this stage of growth is still unclear. The four trials reported herein were designed to evaluate the effect of antibiotics on pig performance under controlled conditions, to evaluate the effect of several different types of floors on pig performance and, in one trial, to look at the interaction between antibiotics and floor types as measured by pig performance

SEARCH AND PURCHASE IN INFORMATION-OVERLOADED RETAIL ELECTRONIC MARKETPLACE: DOES PRICE AND REPUTATIOIN MATTER?

This study explores buyers\u27 search and purchase behavior in an information-overloaded retail Electronic Marketplace (EMP). Two instrumental variables, i.e. number of visitors and number of sales for an item, are used to represent buyers\u27 search and purchase behavior. Price and reputation, two of the most frequently researched independent variables in EMP studies, are considered. The relationships between the two IVs and the two DVs are verified when transaction items are of search-type and of experience-type. This study is conducted using field data collected from Taobao (the most dominant retail EMP in China). It is found that reputation has consistent positive relationships with two DVs. Price has negative effects on two DVs. However, it might have no impacts in the case of experience-type items. Conclusively, in information overloaded EMP, reputation always matters in influencing buyers\u27 search and purchase behavior, while price only matters in the case of search-type items