A Survey of Experimental Research on Contests, All-Pay Auctions and Tournaments

Many economic, political and social environments can be described as contests in which agents exert costly efforts while competing over the distribution of a scarce resource. These environments have been studied using Tullock contests, all-pay auctions and rankorder tournaments. This survey provides a review of experimental research on these three canonical contests. First, we review studies investigating the basic structure of contests, including the contest success function, number of players and prizes, spillovers and externalities, heterogeneity, and incomplete information. Second, we discuss dynamic contests and multi-battle contests. Then we review research on sabotage, feedback, bias, collusion, alliances, and contests between groups, as well as real-effort and field experiments. Finally, we discuss applications of contests to the study of legal systems, political competition, war, conflict avoidance, sales, and charities, and suggest directions for future research. (author's abstract

Ultralight vector dark matter search using data from the KAGRA O3GK run

Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM

The controversial efficacy of vitamin E for human male infertility

Vitamin E (VE) is major lipophilic chain-breaking antioxidant which protects tissue polyunsaturated fatty acids (PUFA) against peroxidation, a property that could be beneficial in the male reproductive physiology because the membranes of germ cells and spermatozoa are very sensitive to oxidation because of their high content of PUFA. Some of the available data on the efficacy of VE as an oral drug for male infertility or as an additive during in vitro manipulations of spermatozoa were reviewed here, observing that they are often contradictory, possibly because: (1) antioxidant therapy could be ineffective in certain studies not concentrated on men in whom oxidative stress is implicated as an infertility factor, and (2) the VE antioxidant therapy is a double-edged sword strictly depending on the dosage or the in vitro concentration of the vitamin. Thus, further laboratory and clinical studies with better-defined experimental conditions should be performed to establish the in vitro and in vivo efficacy of VE for human male infertility

Evaluation of brominated diphenyl ether-99 toxicity with Raphidocelis subcapitata and Daphnia magna

Brominated flame retardants belong to a new class of environmental contaminants. To obtain new information regarding the effects of 2,2',4,4',5-brominated diphenyl ether (BDE-99), one of the most frequently reported congeners in freshwater biota, the inhibition of algal growth of Raphidocelis subcapitara (also known as Selenastrum capricornutum) and acute toxicity to Daphnia magna were examined. The experimental design also involved a comparison with the polychlorinated biphenyl (PCB) Aroclor 1254. The uptake of BDE-99 by R. subcapitata and the transfer to D. magna (i.e., a higher level of aquatic biota in the food chain) was also assessed to verify the bioaccumulation phenomenon. After 24 h, BDE-99 appeared to be less toxic than Aroclor 1254 to D. magna, but the two compounds showed a similar toxicity at 48 h. In contrast to Aroclor 1254, BDE-99 was nontoxic to R. subcapitata at up to 100 microM, the highest tested concentration. However, the dose-dependent decrease in survival and impairment of reproduction of D. magna fed with BDE-99-treated algal culture demonstrate uptake by R. subcapitata. Because of the high persistence and bioconcentration, polybrominated diphenyl ethers as well as PCBs might be of environmental concern for years

A comparative study of Atropa belladonna and atropine on an animal model of urinary retention

The ability of Atropa belladonna L. and atropine to produce urinary retention has been studied in the rat. Our results suggest that A. belladonna is more effective than expected on the basis of its alkaloidic content

In vitro assessment of mutagenicity and clastogenicity of BDE-99, a pentabrominated diphenyl ether flame retardant

Polybrominated diphenyl ethers (PBDEs), which are widely used as flame retardants, are considered persistent organic pollutants. To date, the available toxicological data on PBDEs are limited and were primarily obtained by studying technical blends. The present study was undertaken to investigate the genotoxicity of the pure congener 2,2â\u80²,4,4â\u80²,5-brominated diphenyl ether (BDE-99), one of the major isomers present in penta-commercial products. Bacterial reverse mutation assays in Salmonella typhimurium strains TA98 and TA100 and in Escherichia coli WP2 uvrA, and the Allium cepa chromosome aberration test were carried out to evaluate mutagenicity and clastogenicity. The experimental design also involved testing a well-known polychlorinated biphenyl (PCB) mixture, Aroclor® 1254, which is structurally related to PBDEs. BDE-99 was negative in the bacterial mutagenicity assays, with and without S9 mix. Also, the frequency of structural chromosome aberrations was not significantly higher than the control and no signs of cytotoxicity were observed in BDE99-treated A. cepa. Aroclor® 1254 was not mutagenic, but it induced a significant increase in chromosomal aberrations in A. cepa. In conclusion, BDE-99 was not mutagenic in S. typhimurium or E. coli, or clastogenic in A. cepa; however, the possibility that PBDEs might act through an epigenetic mechanism cannot be excluded. © 2003 Wiley-Liss, Inc

ANTIINFLAMMATORY ACTIVITY OF PFAFFIA PANICULATA (MARTIUS) KUNTZE AND PFAFFIA STENOPHYLLA (SPRENGEL) STUCHL

Ethanolic extracts of Pfaffia paniculata and Pfaffia stenophylla have been tested for their possible anti-inflammatory activity in rats and mice. Both the extracts showed to inhibit the carrageenin-induced oedema in rats and the acetic acid-induced writhing in mice at doses devoid of behavioural effects

Effects of Panax ginseng and Ginkgo biloba on in vitro prolactin secretion

The extracts of Ginkgo biloba and Panax giniseng inhibited the prolactin release in rat cultured pituitary cells. The inhibition was antagonized by haloperidol thus suggesting that the two drugs interact with dopaminergic receptors in pituitary cells