Prenatal exposure to EDCs dis-integrates and reconstitutes neuromolecular-behavioral relationships in adult rats

Exposure to endocrine-disrupting chemicals (EDCs) is ubiquitous in all species, including humans. Previous studies have shown behavioral deficits caused by EDCs that have implications for social competence and sexual selection. The neuromolecular mechanisms for these behavioral changes induced by EDCs have not been thoroughly explored. Here, we tested the hypothesis that EDCs administered to rats during a critical period of embryonic brain development would lead to disruption of normal social preference behavior, and that this involves a network of underlying gene pathways in brain regions that regulate these behaviors. Rats were exposed prenatally to human-relevant concentrations of EDCs [polychlorinated biphenyls (PCB), an industrial chemical mixture; vinclozolin (VIN), a fungicide], or vehicle. In adulthood, a sociosexual preference test (choice between hormone-primed and hormone-depleted opposite-sex rats) was administered. We profiled gene expression of in three brain regions involved in these behaviors [preoptic area (POA), medial amygdala (MeA), ventromedial nucleus (VMN)]. Prenatal PCBs impaired sociosexual preference in both sexes, and VIN disrupted this behavior in males. Each brain region (POA, MeA, VMN) had unique sets of genes altered in a sex- and EDC-specific manner. Sexually dimorphic gene expression disruption was particularly prominent for gene modules pertaining to sex steroid hormones and nonapeptides in the MeA. EDC exposure also changed the relationships between gene expression and behavior in the mate preference test, a pattern we refer to as dis-integration and reconstitution. These findings underscore the profound effects that developmental exposure to EDCs can have on adult social behavior, highlight sex-specific and individual variation in responses, and provide a foundation for further work on the disruption of mate preference behavior after prenatal exposure to EDCs.

Joint financing and ordering decisions in a capital-constrained supply chain with risk preference

We consider a two-echelon supply chain consisting of one dominant supplier and one capital-constrained retailer. The retailer needs to solve the shortage of working capital either from a bank or from its core supplier, which offers trade credit when it is also beneficial to itself. We assume the retailer is risk-averse behavior and the supplier has different risk preference behaviors that jointly model risk-averse, risk-neutral, and risk-taking. With a wholesale price contract, we incorporate each member’s risk preference behavior into its objective function. Then we derive the optimal decisions in a Stackelberg game under bank credit financing and trade credit financing, respectively. We find that there exists a supplier’s risk preference threshold that distinguishes financing scheme. When the supplier is a relatively higher risk preference, trade credit financing makes both the retailer and the supplier better off and is a unique financing equilibrium. Otherwise, the members prefer bank credit financing . Besides, the supplier with relatively higher risk preference behavior prefers the retailer with a low initial capital as a partner; the supplier with relatively lower risk preference behavior prefers the retailer with a higher initial capital level. The above theoretical results are verified by numerical analysis.

Prenatal EDCs Impair Mate and Odor Preference and Activation of the VMN in Male and Female Rats

Environmental endocrine-disrupting chemicals (EDCs) disrupt hormone-dependent biological processes. We examined how prenatal exposure to EDCs act in a sex-specific manner to disrupt social and olfactory behaviors in adulthood and underlying neurobiological mechanisms. Pregnant rat dams were injected daily from embryonic day 8 to 18 with 1 mg/kg Aroclor 1221 (A1221), 1 mg/kg vinclozolin, or the vehicle (6% DMSO in sesame oil). A1221 is a mixture of polychlorinated biphenyls (weakly estrogenic) while vinclozolin is a fungicide (anti-androgenic). Adult male offspring exposed to A1221 or vinclozolin, and females exposed to A1221, had impaired mate preference behavior when given a choice between 2 opposite-sex rats that differed by hormone status. A similar pattern of impairment was observed in an odor preference test for urine-soaked filter paper from the same rat groups. A habituation/dishabituation test revealed that all rats had normal odor discrimination ability. Because of the importance of the ventrolateral portion of the ventromedial nucleus (VMNvl) in mate choice, expression of the immediate early gene product Fos was measured, along with its co-expression in estrogen receptor alpha (ERα) cells. A1221 females with impaired mate and odor preference behavior also had increased neuronal activation in the VMNvl, although not specific to ERα-expressing neurons. Interestingly, males exposed to EDCs had normal Fos expression in this region, suggesting that other neurons and/or brain regions mediate these effects. The high conservation of hormonal, olfactory, and behavioral traits necessary for reproductive success means that EDC contamination and its ability to alter these traits has widespread effects on wildlife and humans.

Foreign directors and corporate governance in Islamic banks

Purpose The purpose of this paper is to examine whether foreign directors’ influence on opportunistic behavior among managers varies between Islamic banks (IBs) and conventional banks (CBs). It also examines how religious ethics and morals guide foreign directors to be better monitors. Design/methodology/approach A panel fixed effects regression is used to analyze the effect of foreign directors on opportunistic behavior among managers in IBs and CBs. The authors use different proxies such as loss avoidance, discretionary loan loss provision and expense preference behavior to measure management opportunistic behavior. Findings Based on sample of 3,758 bank-year observations for 164 banks over the period 1993-2015, the authors show that the presence of foreign directors in IBs increases boards’ effectiveness in impeding management opportunistic behavior, whereas the presence of foreign directors in CBs reduces boards’ effectiveness in curbing management’s unethical acts. The authors also document that IBs (CBs) with foreign directors demonstrate less (more) earnings management and expense-preference behavior among managers. In addition, the authors’ evidence indicates that the existence of the Shari’ah supervisory boards helps foreign directors be more effective monitors. Research limitations/implications The current study focuses on banks only which makes its results subject to sample bias; there are many other forms of financial institutions (e.g. investments, real-estates and mutual funds) complying to the Shari’ah law. Second, owing to the lack of foreign board directors characteristics, the authors cannot investigate the intensity of the specific characteristics that could have specific directions in affecting managerial behavior. Practical implications The findings in this paper may help standards-setters, auditors, investors and regulators take appropriate measures and create better policies that reduce managers’ discretion. This could in turn improve information transparency decision-making, monitoring, advising and accounting quality. Originality/value The authors’ theoretical framework combines the agency, contingency, resource-dependence, stewardship and stakeholders’ theories and applies them to Shari’ah as an alternative ethical and internal governance mechanism. The authors find that the impact of foreign directors on management opportunistic behavior depends on the corporate religious norms within boards of directors, in particular, suggesting that religious values affect how foreign directors influence bank managers’ behavior.

Optimal Decisions of a Green Supply Chain under the Joint Action of Fairness Preference and Subsidy to the Manufacturer

Government subsidy promotes the development of green supply chain, and the influence of decision-makers’ behavioral preferences becomes increasingly prominent in green supply chain management. In order to further enrich the research content of green supply chain, we first use Stackelberg game theory to construct game models by taking the product green degree, wholesale price and retail price as the decision variables, then we work out the equilibrium strategies of the manufacturer and the retailer under four decision scenarios, and reveal the impact differences between the two parties’ fairness preference behaviors. Our research mainly has the following findings: Firstly, the government subsidy to the manufacturer can benefit these two parties and can have certain impact on the optimal decisions only by working with the green product market expansion efficiency. Secondly, these two parties’ fairness preference behaviors can cause serious damage to the other party’s profit and the overall profit of green supply chain, and increase the rate of their own profit in the overall profit of green supply chain, but the difference is that the retailer’s fairness preference behavior can cause a greater decline in product green degree and wholesale price, and when certain conditions are met, its own profit may rise compared to its fairness neutral, while the manufacturer’s fairness preference behavior can cause a greater damage to the overall profit of green supply chainand make its own profit always be lower than its fairness neutral. Thirdly, the government subsidy to the manufacturer and the fairness preference behaviors of both parties can cause a stack effect on the optimal solutions, which means that the subsidy government provides for the manufacturer can aggravate the negative influence caused by these two parties’ fairness preference behaviors.