Spatial Cournot equilibrium: do branches matter?

This paper aims to contribute to the literature of Cournot spatial equilibria in two-dimensional spaces by considering branching. We study the case in which two firms compete on a circle and each one has the possibility of opening one or more branches. An innovative method—polar coordinates—is employed to obtain the complex profit functions. We show that there exists a symmetric subgame perfect Nash equilibrium where both firms place their n branches alternately and at the same distance from the center of the circle. Additionally, we show that this is, up to rotation, the unique symmetric equilibrium location.     

Indications and outcomes of strabismus repair in visually mature patients

OBJECTIVE: To identify and examine the indications, outcomes and potential risks of strabismus surgery in visually mature patients. DESIGN: Case series. SETTING: University-based referral practice in Edmonton. PATIENTS: A total of 222 patients (115 females and 107 males) aged 9 to 69 (mean 29) years who underwent strabismus surgery for various types of strabismus (as grouped by original diagnosis). All patients were followed for at least 6 weeks postoperatively. OUTCOME MEASURES: Previous surgery and deviation in prism dioptres (delta) (distance and near), sensory status (measured by the Titmus stereotest at near) and the presence of symptoms (diplopia, abnormal head posture or asthenopia), recorded preoperatively, 6 weeks postoperatively and at the last postoperative visit. RESULTS: The patients were followed for an average of 14 months postoperatively. At the last postoperative visit 187 patients (84%) were aligned to within 15 delta of orthotropia. Overall, 116 patients (52%) demonstrated some degree of stereopsis postoperatively, compared with 78 (35%) preoperatively. A total of 116 patients (52%) had symptoms preoperatively, including diplopia, abnormal head posture or asthenopia; 88 (76%) of the 116 had complete resolution of their symptoms. Six patients (4%) without diplopia preoperatively were found to have this symptom postoperatively. CONCLUSIONS: The findings suggest that most visually mature patients under-going strabismus surgery can expect functional benefits, including improvement of alignment, preservation and occasionally restoration of sensory fusion, and elimination of diplopia, abnormal head posture and asthenopia.     

Chemically dependent doctors

Overcoming denial and admitting to having a chemical dependency problem is a hurdle that is extraordinarily difficult for anyone to handle without professional assistance. Addicted health care professionals often become even more deeply enmeshed in denial of their problem. They refuse help because they see themselves as educated beyond the level of those who are attempting to help them, and because they fear professional humiliation. Dental professionals who become aware of a colleague's chemical dependence, have an ethical duty to intervene in a constructive way. Reporting to a dental society wellness committee will accomplish this goal while protecting patients, the profession, the addicted provider, and the provider's family. Nonetheless, assisting chemically dependent colleagues to seek treatment can be an enormous burden. Thus, the dental hygienist in the case presented has few choices. She clearly has sufficient evidence of the dentist's chemical dependency problem and, ethically, she must act to prevent harm to patients. If a wellness program is available, it will help her. However, she should not expect gratitude from the dentist at the time of her intervention. Addicted persons rarely thank those who try to help them until much later and whistle-blowers are rarely appreciated. As is often the case, doing the right thing may be a challenge that risks losing a relationship or, as in the case presented, a job.     

Management of R&D projects under uncertainty: a multidimensional approach to managerial flexibility

In this paper, we describe the practical application of a flexibility-based management approach to new product development, highlighting advantages, and limitations of this methodology. The model is concerned with the resolution of uncertainty over the product development life cycle and deals with technical, market, and cost factors all together. To this end, we consider a real options model, which uses multidimensional decision trees, to assess the development process of a high-technology product, namely, the Adaptive Optics Scanning Laser Ophthalmoscope. Moreover, we show how this project could be managed by estimating its value and determining optimal managerial actions to be taken at each review stage of the new product development process. Finally, we draw conclusions about this model's general utility and particular challenges associated with its use as a product development tool, and emphasize the need to consider a multidimensional model, instead of a single dimensional one.     

Study of the luminescent properties of KMgF3:Sm

The photoluminescence (PL), radioluminescence (RL) and thermoluminescence (TL) of KMgF₃ doped at several Sm concentrations have been investigated. The maximum TL and RL yield under beta irradiation has been observed in KMgF₃:Sm 0.02 mol%. The glow curve of this doped perovskite is made up of at least five peaks located at 95, 120, 160, 270, and 330 °C. The third peak appears to be the most convenient for personal or environmental dosimetry, since it shows no fading and good linearity within the investigated dose range (0.020-200 Gy). From the RL and PL spectra it has been found that most of KMgF₃:Sm emission is located at wavelengths higher than 650 nm. This emission, which is characteristic of Sm²⁺, makes this doped compound attractive for fiber-optic dosimetry.     

A multispectral imaging technique to determine concentration profiles of myoglobin derivatives during meat oxygenation

We have designed a multispectral imaging acquisition system to measure the relative concentration values of myoglobin forms inside meat during oxygenation. Images at 474, 525, 572 and 610 nm are used to compute the concentration of reduced myoglobin, oxymyoglobin and metmyoglobin with a spatial resolution of 0.0125 mm/pixel. From these images, pigment concentration profiles as a function of oxygenation time and depth beneath the surface were obtained. A model describing the diffusion of oxygen and the consumption of reduced myoglobin is numerically tested versus the measured concentration profiles. The model accurately fits the data with a Mean Root Squared Error equal to 0.253%. Precise definitions for position and width of pigment layers based in concentration profiles are given. The results suggest that multispectral imaging techniques combined with precise control and measurement of sample temperature and oxygen partial pressure will permit detailed studies of the myoglobin chemistry during oxygenation.     

Polymer Cocktail: A Multitask Supported Ionic Liquid‐Like Species to Facilitate Multiple and Consecutive C?C Coupling Reactions

Polymer‐supported ionic liquid‐like species (SILLPs) with different functionalities have been combined to obtain new catalytic systems (polymer cocktail) with improved properties towards their application for C C coupling reactions. The SILLPs have been synthesized in a simple way and combined to play different functions in the reaction medium. Those roles involve simultaneously (or consecutively) their actuation as supported reagents, precatalysts and scavengers of undesired reaction side‐products. The system has been tested by employing three different C C coupling reactions for 8 consecutive cycles. Moreover, different aryl bromides and iodides have proved to be efficiently transformed by the catalytic cocktail. Finally, the Heck reaction has been conducted in continuous‐flow conditions using a packed bed of this polymer cocktail and employing supercritical carbon dioxide (scCO₂) as a solvent, which cannot be carried out with the use of soluble bases as this would lead to the clogging of the reactor. Finally, the SILLPs cocktail enables one to combine different reaction steps and purification in a single vessel, which represents a significant improvement in terms of process intensification and green chemistry. This is particularly true in the case of the use of scCO₂ as this allows the direct production of crude materials not contaminated either by salts or by solvents.     

Polycyclic N-benzamido imides with potent activity against vaccinia virus

The synthesis and antiviral activity of a series of novel polycyclic analogues of the orthopoxvirus egress inhibitor tecovirimat (ST‐246) is presented. Several of these compounds display sub‐micromolar activity against vaccinia virus, and were more potent than cidofovir (CDV). The more active compounds were about 10‐fold more active than CDV, with minimum cytotoxic concentrations above 100 μM . Chemical manipulations of the two carbon–carbon double bonds present in the compounds were carried out to further explore the structure–activity relationships of these new polycyclic imides. Hydrogenation of the two carbon–carbon double bonds decreases antiviral activity, whereas either cyclopropanation or epoxidation of the double bonds fully eliminates the antiviral activity.     

Effect of maturity, processing, and storage on the furanocoumarin composition of grapefruit and grapefruit juice

Since the early 1990's, grapefruit juice has been implicated in drug interaction with various furanocoumarins (FCs) now associated with the effect. Although FCs are present in various fruits and vegetables, it is their presence in grapefruit that has attracted the most attention. Studies have shown that FCs in grapefruit juice can vary significantly and from multiple causes. Most of all, FCs are stress-induced molecules, their levels affected by many factors ranging from UV exposure to insect infestation. There are also varietal and seasonal factors. In this study, juice processing and storage parameters were investigated. Prolonged fruit storage prior to processing and most steps involved in juice processing had little influence on the levels of 6',7'-dihydroxybergamottin (DHB), paradisin C, or bergamottin. However, products that were hot filled or stored at room temperature had lower amounts of DHB and paradisin C and higher amounts of bergaptol compared to juices that were not hot filled and stored at refrigerated temperatures. Both DHB and paradisin C are potent CYP3A4 inhibitors, while bergaptol is a very weak inhibitor. Bergamottin amounts decreased to a lesser extent. Therefore, grapefruit juice products that were hot filled or have been stored at room temperature for an extended period of time will have a reduced drug interaction potential.     

Effects of storage in slurry ice on the microbial,chemical and sensory quality and on the shelf life of farmed turbot (Psetta maxima)

The application of slurry ice, a binary mixture of small spherical ice crystals surrounded by seawater at subzero temperature, is a potentially new preservation method for farmed turbot (Psetta maxima), a flat fish species of increasing commercial interest. Comparative biochemical, microbiological and sensory analyses were carried on turbot specimens stored in either slurry ice or flake ice for up to 40 days. The results obtained in the sensory analysis correlated well with the observed chemical and microbial changes. Storage of turbot in slurry ice resulted in a slowing-down of the nucleotide degradation pathway and lipid oxidation mechanisms. A good stabilisation of the high molecular weight protein fraction of turbot muscle was also achieved as a consequence of storage in slurry ice. A slower production of both trimethylamine and total volatile bases was also observed. Likewise, low levels of total aerobes, anaerobes, coliforms, and proteolytic bacteria were attained. The application of slurry ice to farmed turbot is advisable to achieve better quality maintenance during storage and distribution.