‘Guaranteed lowest prices: do they facilitate collusion?’: Revisited

We examine the effect of guaranteed lowest price clauses (G.L.P.). First, we correct the proof of Logan and Lutter’s main result that it is the unique equilibrium outcome for firms adopting G.L.P. to charge collusive prices in a simultaneous pricing game, if one uses the trembling-hand perfect equilibrium as the solution concept. Second, we extend their argument to a sequential pricing game in which one firm chooses its price before the other, given that both firms adopt G.L.P. We show that collusive prices is the unique equilibrium outcome in this game even without resorting to any stringent refinement like the trembling-hand perfect equilibrium

Strategic delegation and second mover advantage in duopoly

We consider a duopoly in which each firm has one owner and one manager playing a multi-stage delegation game. The decision of each firm consists of two stages. In the first stage, the owner offers his manager a contract based on profits and sales. In the second stage, the manager chooses its output or price. Several possible sequential games will be analysed, depending on the sequence of the strategic variables. In the first scenario in which firm 1 makes a contract decision and a producing decision sequentially, and firm 2 follows in the same fashion, we show that any delegation equilibrium in which both owners commit their managers to profit-maximising behaviour disappears. In the second scenario in which the firms first enter into the contract stage and then Stackelberg competition follows in the second stage, sales-based delegation occurs. If firms compete in quantities, second mover advantage appears if firms make simultaneous delegation contracts, while first mover advantage is recovered if they make sequential contracts. If firms compete in prices, the results are reversed

CT Evidence for Subchondral Trabecular Injury of the Femoral Head in Transient Osteoporosis of the Hip: A Case Report

A 28-yr-old woman presented with both hip pain that started sequentially during the peripartum period. Diagnosis of transient osteoporosis of the hip (TOH) was made based on typical findings of plain radiographs and magnetic resonance images. The subchondral trabeculae of the femoral head were evaluated on serially taken coronal multiplanar reformation computerized tomogram images. At 4 weeks after pain onset, marked decrease in the sclerotic density with irregular discontinuation was observed in the primary compression trabeculae. At 12 weeks, a focal area of irregular thickening of trabeculae was observed. At 20 weeks, sclerotic density of trabeculae recovered markedly and the focal area of irregular trabecular thickening disappeared. At 1 yr, subchondral trabeculae recovered almost completely. The evidence of subchondral trabecular injury was observed in the femoral heads of TOH

The role of 99mTc-DPD bone SPECT/CT in the management of growth disturbance of the long bones in pediatric patients: a retrospective observational study

Backgrounds Determining the precise localization of diseased physes is crucial for guiding the treatment of growth disturbances. Conventional radiography, computed tomography (CT), and magnetic resonance imaging only provide information on physeal anatomy. Planar bone scintigraphy and bone single-photon emission computed tomography (SPECT) resolutions are suboptimal for clinically managing growth disturbances. Bone SPECT/CT, which provides high-resolution functional information, can be a useful tool for evaluating growth disturbances. The purposes of this study were to identify the conditions in which bone SPECT/CT outperforms planar scintigraphy or SPECT for evaluating the location and activity of diseased physes and to assess surgical outcomes using bone SPECT/CT findings in pediatric patients experiencing long bone growth disturbances. Methods Fifty-nine patients who underwent bone SPECT/CT between January 2018 and January 2021 to evaluate physeal activity using technetium-99 m-labeled 2,3-dicarboxypropane-1,1-diphosphonate (99mTc-DPD) were included. The proportions of patients for whom certain modalities provided sufficient data for selecting treatment plans for growth disturbances were compared based on the site of the diseased physis, growth disturbance cause, and shape of deformity (i.e., SPECT/CT vs. planar scintigraphy and SPECT/CT vs. SPECT). For assessing surgical outcomes, progression of post-surgical deformity was investigated by measuring the angles reflecting the degree of deformity, iliac crest height difference, or ulnar variance on radiographs. Results Bone SPECT/CT was sufficient for selecting a treatment plan, but planar scintigraphy or SPECT alone was insufficient in every 10 patients with diseased physes inside the femoral head (p = 0.002) and in every six with physes that were severely deformed or whose locations were unclear on conventional radiography (p = 0.03). In the proximal or distal tibia, where the tibial and fibular physes often overlapped on planar scintigraphy due to leg rotation, bone SPECT/CT was sufficient in 33/34 patients (97%), but planar scintigraphy and SPECT were sufficient in 10/34 (29%) (p < 0.001) and 24/34 (71%) patients, respectively (p = 0.004). No progression or deformity recurrence occurred. Conclusions Bone SPECT/CT may be indicated in proximal femoral growth disturbance, when the physis is unclear on conventional radiography or severely deformed, the leg exhibits rotational deformity, or the patient is noncompliant

Sequences of the Cytochrome C Oxidase Subunit I (COI) Gene are Suitable for Species Identification of Korean Calliphorinae Flies of Forensic Importance (Diptera: Calliphoridae)

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75068/1/j.1556-4029.2009.01126.x.pd

Optimization of protoplast regeneration in the model plant Arabidopsis thaliana

Background Plants have a remarkable reprogramming potential, which facilitates plant regeneration, especially from a single cell. Protoplasts have the ability to form a cell wall and undergo cell division, allowing whole plant regeneration. With the growing need for protoplast regeneration in genetic engineering and genome editing, fundamental studies that enhance our understanding of cell cycle re-entry, pluripotency acquisition, and de novo tissue regeneration are essential. To conduct these studies, a reproducible and efficient protoplast regeneration method using model plants is necessary. Results Here, we optimized cell and tissue culture methods for improving protoplast regeneration efficiency in Arabidopsis thaliana. Protoplasts were isolated from whole seedlings of four different Arabidopsis ecotypes including Columbia (Col-0), Wassilewskija (Ws-2), Nossen (No-0), and HR (HR-10). Among these ecotypes, Ws-2 showed the highest potential for protoplast regeneration. A modified thin alginate layer was applied to the protoplast culture at an optimal density of 1 × 106 protoplasts/mL. Following callus formation and de novo shoot regeneration, the regenerated inflorescence stems were used for de novo root organogenesis. The entire protoplast regeneration process was completed within 15 weeks. The in vitro regenerated plants were fertile and produced morphologically normal progenies. Conclusion The cell and tissue culture system optimized in this study for protoplast regeneration is efficient and reproducible. This method of Arabidopsis protoplast regeneration can be used for fundamental studies on pluripotency establishment and de novo tissue regeneration.This work was supported by the Samsung Science and Technology Foundation under Project Number SSTF-BA2001-10

Optimization of protoplast regeneration in the model plant Arabidopsis thaliana

Background Plants have a remarkable reprogramming potential, which facilitates plant regeneration, especially from a single cell. Protoplasts have the ability to form a cell wall and undergo cell division, allowing whole plant regeneration. With the growing need for protoplast regeneration in genetic engineering and genome editing, fundamental studies that enhance our understanding of cell cycle re-entry, pluripotency acquisition, and de novo tissue regeneration are essential. To conduct these studies, a reproducible and efficient protoplast regeneration method using model plants is necessary. Results Here, we optimized cell and tissue culture methods for improving protoplast regeneration efficiency in Arabidopsis thaliana. Protoplasts were isolated from whole seedlings of four different Arabidopsis ecotypes including Columbia (Col-0), Wassilewskija (Ws-2), Nossen (No-0), and HR (HR-10). Among these ecotypes, Ws-2 showed the highest potential for protoplast regeneration. A modified thin alginate layer was applied to the protoplast culture at an optimal density of 1 x 10(6) protoplasts/mL. Following callus formation and de novo shoot regeneration, the regenerated inflorescence stems were used for de novo root organogenesis. The entire protoplast regeneration process was completed within 15 weeks. The in vitro regenerated plants were fertile and produced morphologically normal progenies. Conclusion The cell and tissue culture system optimized in this study for protoplast regeneration is efficient and reproducible. This method of Arabidopsis protoplast regeneration can be used for fundamental studies on pluripotency establishment and de novo tissue regeneration.Y

Femoral Head Fracture without Dislocation by Low-Energy Trauma in a Young Adult

We describe the case of a healthy young man with a femoral head fracture by low-energy trauma that occurred without evidence of hip dislocation. While plain radiographs showed no definite fracture or dislocation, computed tomography (CT) and magnetic resonance imaging (MRI) revealed a femoral head fracture with a wedge-shaped cortical depression at the superomedial aspect of the femoral head. Our patient reported feeling that the right hip had been displaced from its joint for a moment. This probably represented subluxation with spontaneous relocation. The characteristic findings and possible mechanisms of this fracture were postulated on the basis of the sequential 3 dimensional-CT and MRI. The clinical results of conservative treatment were better than those of previously reported indentation fractures

Diffuse Interstitial Infiltrative Lung Metastasis of Malignant Melanoma: a Case Report

A diffuse interstitial infiltrative pattern of lung metastasis in a patient with malignant melanoma is rare and can be confused with benign conditions such as pulmonary edema or drug-induced pneumonitis. We experienced a case of diffuse interstitial infiltrative lung metastasis in malignant melanoma in a 37-year-old man. This case was confirmed by a transbronchial lung biopsy. We herein describe the findings on CT and positron emission tomography scan