Collaboration in R&D activities: Firm-specific decisions

In this paper, we study the strategic R&D collaboration by introducing a virtual player to reveal cooperative incentives and keeping investment share and market share independent of each other. Not consistently with the traditional opinions, we show that the superiority of the R&D cartel is due to the coexistence of cooperation and competition when spillovers are exogenous. Moreover, we conclude that high R&D input share must be reflected implicitly by high market share, and that firms’ R&D decisions vary with firms’ specific characteristics when spillovers is endogenous.     

烟台经济可持续发展能力的定量研究

建立了评价烟台经济可持续发展能力的指标体系,对其可持续发展能力进行定量评价,根据综合指标的得分值对烟台各市(县)区可持续发展能力进行了排序,结合各市(县)区的地域分布划分出不同的可持续发展类型区,并对各类型区可持续发展能力的主要构成因素进行了分析,为烟台地区经济可持续发展的决策、管理和调控提供重要的依据.     

LC‐APCI mass spectrometric method development and validation for the determination of atovaquone in human plasma

A newly developed LC—APCI mass spectrometric method is described for human plasma determination of atovaquone using lapachol internal standard. A single‐step protein precipitation technique for plasma extraction of atovaquone achieving mean recovery of 94.17% (CV 8%) without compromising sensitivity (limit of quantitation 50.3 ng/mL) or linearity (50.3 ng/mL—23924.6 ng/mL) is delineated in this paper. Heated nebulizer in negative multiple reaction monitoring mode was employed with transitions m/z 365.2 → m/z 337.1 and m/z 240.9 → m/z 185.7 for atovaquone and lapachol respectively in this liquid chromatographic–tandem mass spectrometric method. Excellent chromatographic separation on a Synergi 4 μ Polar‐RP 80A (150 × 2.0 mm) column, using 100 μL of plasma extraction volume along with 10 μL of injection load, completing analysis run‐time within 2.5 min, highlights this simple yet unique bioanalytical method. The developed method can be successfully applied to pharmacokinetic studies on atovaquone suspension administered in healthy volunteers or HIV‐infected patients. Moreover full method validation results not published before are presented and discussed in detail for the first time in this article. Copyright © 2009 John Wiley & Sons, Ltd.     

Managing the exchange of information in product development

In the present paper, we develop a dynamic programming (DP) model of the product development (PD) process. We conceptualize product development as a sequence of decisions: whether to incorporate a piece of information that just arrived (i.e. became available) or wait longer. We utilize this formulation to analyze different situations that depend on the type, and nature of information that is exchanged: stationary versus dynamic information. We derive optimal decision rules to determine whether (and when) to incorporate for each case. An analysis of the model results in several important findings. First, we must not necessarily incorporate all available information that is related to the design activity. Specifically, once the information collection exceeds certain value, the design team should stop collecting further information. Second, only when past design work accumulates to a certain threshold value should the team include the latest information and perform rework. Large uncertainty of the information and large sensitivity of the design activity makes the incorporation of new information less likely. Finally, managerial implications are discussed with several numerical examples.     

Modeling methods and a branch and cut algorithm for pharmaceutical clinical trial planning using stochastic programming

We discuss methods for the solution of a multi-stage stochastic programming formulation for the resource-constrained scheduling of clinical trials in the pharmaceutical research and development pipeline. First, we present a number of theoretical properties to reduce the size and improve the tightness of the formulation, focusing primarily on non-anticipativity constraints. Second, we develop a novel branch and cut algorithm where necessary non-anticipativity constraints that are unlikely to be active are removed from the initial formulation and only added if they are violated within the search tree. We improve the performance of our algorithm by combining different node selection strategies and exploring different approaches to constraint violation checking.     

Protection of aluminum hydroxide during lyophilisation as an adjuvant for freeze-dried vaccines

Lyophilisation of an aluminum hydroxide adjuvant containing formulation for use in vaccine development has been investigated. Novel formulation approaches using disaccharides, polysaccharides, polyols and polymers have been investigated as stabilising excipients to prevent aluminum hydroxide adjuvant from aggregation during a freeze–thaw cycle or the lyophilisation process itself. Amorphous character of the lyophilisates was investigated by wide angle X-ray diffraction. Sedimentation assay, particle size analysis and optical microscopy could show that aluminum adjuvant gel character of selected formulations could be maintained within acceptable quality or stayed the same in some cases. In principle, it could be demonstrated that not less than 10% excipient is necessary to yield good results within applied analytics evaluating the excipients’ protecting qualities. Based on results obtained by this study, the formulations containing trehalose at a concentration of 15 or 20%, dextran, PVP K 25, HES 450 and 200, saccharose and sorbitole along with polysorbate 80 and buffer promise to be good candidates for the protection of aluminum adjuvanted vaccines during exposure to coldness stresses as during freezing or lyophilisation.     

我国钢铁行业上市公司可持续增长状况的实证分析

高速增长,快速扩张是许多企业追求的目标,但理论和实践均证明企业增长或扩张速度并非越快越好,企业的增长速度只有与自身的经营效率、财务政策相匹配,才具有可持续性。本文选取沪深两市32家钢铁行业上市公司为样本,以罗伯特·希金斯和詹姆斯·范霍恩的可持续增长模型作为理论基础,通过描述性统计、Wilcoxon Signed Ranks检验等统计方法检验钢铁行业的增长现状及其增长的可持续性。研究结果表明:近年我国钢铁行业上市公司的实际增长率远远超过了可持续增长率,如此高速增长并不具有可持续性;在整个行业高速增长的背景下,其可持续增长率却逐年下滑;盈利能力下降是导致可持续增长率下滑的主要原因。只有采取增加产品技术含量和附加值,降低运营成本,提高技术装备水平等措施提高盈利能力,进而提高可持续增长率,并使企业实际增长率与可持续增长率相匹配,钢铁企业才可能实现快速可持续发展。     

Independence for full conditional probabilities: Structure,factorization, non-uniqueness,and Bayesian networks

This paper examines concepts of independence for full conditional probabilities; that is, for set-functions that encode conditional probabilities as primary objects, and that allow conditioning on events of probability zero. Full conditional probabilities have been used in economics, in philosophy, in statistics, in artificial intelligence. This paper characterizes the structure of full conditional probabilities under various concepts of independence; limitations of existing concepts are examined with respect to the theory of Bayesian networks. The concept of layer independence (factorization across layers) is introduced; this seems to be the first concept of independence for full conditional probabilities that satisfies the graphoid properties of Symmetry, Redundancy, Decomposition, Weak Union, and Contraction. A theory of Bayesian networks is proposed where full conditional probabilities are encoded using infinitesimals, with a brief discussion of hyperreal full conditional probabilities.     

The application of a mathematical model of sustainability to the results of a semi-quantitative Environmental Impact Assessment of two iron ore opencast mines in Iran

The paper outlines the application of a mathematical model of sustainability to an Environmental Impact Assessment (EIA) of two opencast iron ore mines in Iran. The model’s application to the EIA, which used the Folchi method, was undertaken for the purpose of indicating the potential level and nature of sustainability (if appropriate) of the two mines.The results indicated that both Chogart and Gol-e-Gohar iron ore mine were deemed to be potentially unsustainable. The results suggests the delicate balance and failure of achieving some form of sustainability in regards to mining in Iran, due to the impacts it has upon the local environment and community affected. The paper concludes as to the potential significance of the model’s application in the attainment of the goal of sustainable mining.