A tri-level optimization model for inventory control with uncertain demand and lead time

We propose an inventory control model for an uncapacitated warehouse in a manufacturing facility under demand and lead time uncertainty. The objective is to make ordering decisions to minimize the total system cost. We introduce a two-stage tri-level optimization model with a rolling horizon to address the uncertain demand and lead time regardless of their underlying distributions. In addition, an exact algorithm is designed to solve the model. We compare this model in a case study with three decision-making strategies: optimistic, moderate, and pessimistic. Our computational results suggest that the performances of these models are either consistently inferior or highly sensitive to cost parameters (such as holding cost and shortage cost), whereas the new tri-level optimization model almost always results in the lowest total cost in all parameter settings

Anti-ulcerogenic efficacy and mechanisms of edible and natural ingredients in NSAID-induced animal models

Background: Nonsteroidal anti-inflammatory drugs (NSAIDs) are a class of the most commonly used medicines and proven to be effective for certain disorders. Some people use NSAIDs on daily basis for preventive purpose. But a variety of severe side effects can be induced by NSAIDs. Studies have shown that edible natural ingredients exhibit preventive benefit of gastric ulcer. This paper reviews the efficacy and safety of edible natural ingredients in preventing the development of gastric ulcer induced by NSAIDs in animal models.Methods: A systematic literature search was conducted on PubMed, using the terms “herbal medicines” and “gastric ulcer”, “herbal medicines” and “peptic ulcer”, “food” and “peptic ulcer”, “food” and “gastric ulcer”, “natural ingredient” and “peptic ulcer”, “natural ingredient” and “gastric ulcer”, “alternative medicine” and “peptic ulcer”, “alternative medicine” and “gastric ulcer”, “complementary medicine” and “peptic ulcer”, “complementary medicine” and “gastric ulcer” in papers published in English between January 1, 1960 and January 31, 2016, resulting in a total of 6146 articles containing these terms. After exclusion of studies not related prevention, not in NSAID model or using non-edible natural ingredients, 54 articles were included in this review.Results: Numerous studies have demonstrated that edible natural ingredients exhibit antiulcerogenic benefit in NSAIDinduced animal models. The mechanisms by which edible, ingredient-induced anti-ulcerogenic effects include stimulation of mucous cell proliferation, antioxidation, inhibition of gastric acid secretion, as well as inhibition of H(+), K(+)- ATPase activities. Utilization of edible, natural ingredients could be a safe, valuable alternative to prevent the development of NSAID-induced gastric ulcer, particularly for the subjects who are long-term users of NSAIDs.Keywords: Food, Gastric ulcer, Prevention, Animal models，Nonsteroidal anti-inflammatory drug

Regulation of Migration in Mythimna separata (Walker) in China: A Review Integrating Environmental, Physiological, Hormonal, Genetic, and Molecular Factors

Each year the Mythimna separate (Walker), undertakes a seasonal, long-distance, multigeneration roundtrip migration between southern and northern China. Despite its regularity, the decision to migrate is facultative, and is controlled by environmental, physiological, hormonal, genetic, and molecular factors. Migrants take off on days 1 or 2 after eclosion, although the preoviposition period lasts ≈7 d. The trade-offs among the competing physiological demands of migration and reproduction are coordinated in M. separata by the “oogenesis-flight syndrome.” Larvae that experience temperatures above or below certain thresholds accompanied by appropriate humidity, short photoperiod, poor nutrition, and moderate density tend to develop into migrants. However, there is a short window of sensitivity within 24 h after adult eclosion when migrants can be induced to switch to reproductive residents if they encounter extreme environmental factors including starvation, low temperature and long photoperiod. Juvenile hormone (JH) titer is low before migration but high titers are associated with termination of migratory behavior and the switch to reproduction. Early release of JH by the corpora allata in environmentally stressed 1-d old adults, otherwise destined by larval conditions to be migrants, switches them to residents. Offspring inherit parental additive genetic effects governing migratory behavior. However, they also retain flexibility in expression of both flight and reproductive life history traits. The insect neuropeptide, allatotropin, which activates corpora allata to synthesize JH, controls adult flight and reproduction. Future research directions to better understand regulation of migration in this species are discussed

Complementarity‐based selection strategy for genomic selection

Genomic selection is a technique that breeders use to select plant or animal individuals to mate and produce new generations of species. The conventional selection method is to select individuals that are either observed or predicted to be the best based on the assumption that parents with better phenotypes will produce better offspring. A major limitation of this method is its focus on the short‐term genetic gains at the cost of genetic diversity and long‐term growth potential. Recently, several new genomic selection methods were proposed to maximize the long‐term potential. Along this research direction, we propose a new method, the complementarity‐based selection strategy (CBS), to improve the tradeoff between short‐term genetic gain and long‐term potential. This approach is inspired by the genetic compatibility mate‐choice mechanism in animals. Our selection method selects the individual with the highest genomic estimated breeding value to emphasize short‐term achievement and then pairs it with the individual that is the most complementary to the one with highest genomic estimated breeding value to emphasize the long‐term growth potential. The CBS method allows favorable alleles to be accounted for within the selection and more of them to be included. We present simulation results that compare the performance of the new method against the state‐of‐the‐art methods in the literature and show that the CBS approach has a great potential to further improve long‐term response in genomic selection