593 research outputs found
Recent Evidence on Improved Inventory Control: A quarterly Model of the US Economy for the period 1959-2001
This Paper aimed to re-test the hypothesis whether the improved inventory control affects the inventory investment or not. This paper used Bechter and Stanley (1992) model. The contribution of this letter has two dimensions; first, this paper extends the time horizon by using a quarterly data of the U.S. economy for the period 1959-2001. Also, it modifies Bechter and Stanley model under certain assumption and use the adjusted model to re-exam the hypothesis. The results of the paper support the idea that improved inventory control has a significant impact on the behavior of inventory investment. In addition, it shows that the improvement vary from one sector to another. Further, the paper showed that the speed of adjustment will be faster if the firms ignore holding inventories as a buffer stock.inventory control, model, economy, USA
Does Inflation Harm Economic Growth in Jordan?. An Econometric Analysis for the Period 1970-2000.
It is expected that inflation we will be an important issue in Jordan because the central bank of Jordan is adopting an easy monetary policy to help promoting the financial market.Therefore, this paper explores the relation between inflation and economic growth to check whether if this relation has a structural breakpoint effect or not.This paper shows that the structural breakpoint effect occurs at inflation rate equal to 2% and after this level the effect turns to be negative. This result says that the maneuver of the monetary policy will be very limited. And, the central bank of Jordan should pay attention to the inflation phenomenon while conducting the new monetary policy.Inflation, Economic Growth, Jordan, Arch Models
The central bank cost constraint and output-inflation variability: a note on Cecchetti and Ehrmann 2000
The goal of this paper is to extend the model of Cecchetti and Ehrmann 2000 to study the case of developing countries that have a constraint in conducting their monetary policies. Contrary to Cecchetti and Ehrmann 2000 model, our model shows that the existence of such a constraint i.e. cost restriction allows the aggregate demand shock to affect the output-inflation variability. Our model also shows that adding a monetary policy cost restriction to the central bank loss function leads to either a steeper or flatter efficient frontier. This implies that the effect of monetary policy to offset aggregate demand and supply shocks is reduced.Central bank losses
Nodular Sarcoidosis Masquerading as Cancer.
Nodular lung disease is a rare pulmonary manifestation of sarcoidosis and resembles metastatic neoplasm disease. Nodular sarcoidosis is rare, varying from 1.6% to 4% of patients with sarcoidosis. Radiographic nodules measure from 1 to 5 cm in diameter that typically consist of coalescent granulomas. There is limited data on this form of sarcoidosis and its presentation can mimic primary or metastatic pulmonary neoplasms. Nodular sarcoidosis has a favorable prognosis, and resolution can be seen with oral corticosteroids. Herein, we present such a case of nodular pulmonary sarcoidosis with a lung nodule measured up to 6 cm
Amiodarone-Induced Pulmonary Toxicity - A Frequently Missed Complication.
IntroductionAmiodarone is often used in the suppression of tachyarrhythmias. One of the more serious adverse effects includes amiodarone pulmonary toxicity (APT). Several pulmonary diseases can manifest including interstitial pneumonitis, organizing pneumonia, acute respiratory distress syndrome, diffuse alveolar hemorrhage, pulmonary nodules or masses, and pleural effusion. Incidence of APT varies from 5-15% and is correlated to dosage, age of the patient, and preexisting lung disease.DescriptionA 56-year-old male with a past medical history of coronary artery disease and chronic obstructive pulmonary disease was admitted for a coronary artery bypass graft. Post-operatively, the patient was admitted to the ICU for ventilator management and continued to receive his home dose of amiodarone 400 mg orally twice daily, which he had been taking for the past 3 months. The patient was found to be hypoxemic with a PaO2 52 mmHg and bilateral infiltrates on chest x-ray. Patient also complained of new onset dyspnea. Physical exam found bilateral rhonchi with bibasilar crackles and subcutaneous emphysema along the left anterior chest wall. Daily chest x-rays showed worsening of bilateral interstitial infiltrates and pleural effusions. A chest high-resolution computed tomography on post-operative day 3 showed extensive and severe bilateral ground glass opacities. APT was suspected and amiodarone was discontinued. A course of oral prednisone without antibiotics was initiated, and after one week of treatment the chest film cleared, the PaO2 value normalized and dyspnea resolved.DiscussionAPT occurs via cytotoxic T cells and indirectly by immunological reaction. Typically the lungs manifest a diffuse interstitial pneumonitis with varying degrees of fibrosis. Infiltrates with a 'ground-glass' appearance appreciated on HRCT are more definitive than chest x-ray. Pulmonary nodules can be seen, frequently in the upper lobes. These are postulated to be accumulations of amiodarone in areas of previous inflammation. Those undergoing major cardiothoracic surgery are known to be predisposed to APT. Some elements require consideration: a baseline pulmonary function test (PFT) did not exist prior. APT would manifest a restrictive pattern of PFTs. In APT diffusing capacity (DLCO) is generally >20 percent from baseline. A DLCO was not done in this patient. Therefore, not every type of interstitial lung disease could be ruled out. Key features support a clinical diagnosis: (1) new dyspnea, (2) exclusion of lung infection, (3) exclusion of heart failure, (4) new radiographic features, (5) improvement with withdrawal of amiodarone. Our case illustrates consideration of APT in patients who have extensive use of amiodarone and new onset dyspnea
Diagnostic and therapeutic considerations in idiopathic hypereosinophilia with warm autoimmune hemolytic anemia.
Hypereosinophilic syndrome (HES) encompasses numerous diverse conditions resulting in peripheral hypereosinophilia that cannot be explained by hypersensitivity, infection, or atopy and that is not associated with known systemic diseases with specific organ involvement. HES is often attributed to neoplastic or reactive causes, such as chronic eosinophilic leukemia, although a majority of cases remains unexplained and are considered idiopathic. Here, we review the current diagnosis and management of HES and present a unique case of profound hypereosinophilia associated with warm autoimmune hemolytic anemia requiring intensive management. This case clearly illustrates the limitations of current knowledge with respect to hypereosinophilia syndrome as well as the challenges associated with its classification and management
A Case of Statin-Associated Autoimmune Myopathy.
A 70-year-old previously independent man developed progressive proximal leg weakness resulting in a fall at home suffering traumatic brain injury. He was prescribed a statin medication two years prior, but this was discontinued on admission to the hospital due to concern for statin myopathy. His weakness continued to progress while in acute rehabilitation, along with the development of dysphagia requiring placement of gastrostomy tube and respiratory failure requiring tracheostomy. Corticosteroids and intravenous immunoglobulin were administered without response. Nerve conduction study demonstrated no evidence of neuropathy; electromyography revealed spontaneous activity suggestive of myopathy. A muscle biopsy was performed and demonstrated myonecrosis. Serology was positive for autoantibodies to 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR), verifying our diagnosis of statin-associated autoimmune myopathy (SAM). The patient was subsequently treated with rituximab and methotrexate and demonstrated mild clinical improvement. He was eventually liberated from the ventilator. However, later in the course of treatment, he developed respiratory distress and required ventilator support. The patient was discharged to long-term acute care two months after his initial presentation and died due to ventilator-acquired pneumonia three months later. Since their introduction 30 years ago, statin medications have been widely prescribed to prevent cardiovascular diseases. Myalgias and/or myopathic symptoms are among the most recognized side effects of the medication. Statin-associated autoimmune myopathy is a very rare complication of statin use and estimated to affect two to three for every 100,000 patients treated. Clinically, the condition presents as progressive symmetric weakness, muscle enzyme elevations, necrotizing myopathy on muscle biopsy, and the presence of autoantibodies to HMGCR. These findings will often persist and even progress despite discontinuation of the statin. Very few cases of SAM have been described in the literature. Describing this rare condition and the ultimately fatal outcome of our patient, we aim to further understanding of SAM, its presentation and clinical course to promote earlier diagnosis and prompt management
PHEN : parkinson helper emergency notification system using Bayesian Belief Network
Context-aware systems are used to aid users in their daily lives. In the recent years, researchers are exploring how context aware systems can benefit humanity through assist patients, specifically those who suffer incurable diseases, to cope with their illness. In this paper, we direct our work to help people who suffer from Parkinson disease. We propose PHEN, Parkinson Helper Engine Network System, a context-aware system that aims to support Parkinson disease patients on m any levels. We use ontology is for context representation and modeling. Then the ontology based context model is used to learn with Bayesian Belief network (BBN) which is beneficial in handling the uncertainty aspect of context-aware systems
Resource Optimization in Wireless Sensor Networks for an Improved Field Coverage and Cooperative Target Tracking
There are various challenges that face a wireless sensor network (WSN) that mainly originate from the limited resources a sensor node usually has. A sensor node often relies on a battery as a power supply which, due to its limited capacity, tends to shorten the life-time of the node and the network as a whole. Other challenges arise from the limited capabilities of the sensors/actuators a node is equipped with, leading to complication like a poor coverage of the event, or limited mobility in the environment. This dissertation deals with the coverage problem as well as the limited power and capabilities of a sensor node.
In some environments, a controlled deployment of the WSN may not be attainable. In such case, the only viable option would be a random deployment over the region of interest (ROI), leading to a great deal of uncovered areas as well as many cutoff nodes. Three different scenarios are presented, each addressing the coverage problem for a distinct purpose. First, a multi-objective optimization is considered with the purpose of relocating the sensor nodes after the initial random deployment, through maximizing the field coverage while minimizing the cost of mobility. Simulations reveal the improvements in coverage, while maintaining the mobility cost to a minimum. In the second scenario, tracking a mobile target with a high level of accuracy is of interest. The relocation process was based on learning the spatial mobility trends of the targets. Results show the improvement in tracking accuracy in terms of mean square position error. The last scenario involves the use of inverse reinforcement learning (IRL) to predict the destination of a given target. This lay the ground for future exploration of the relocation problem to achieve improved prediction accuracy. Experiments investigated the interaction between prediction accuracy and terrain severity.
The other WSN limitation is dealt with by introducing the concept of sparse sensing to schedule the measurements of sensor nodes. A hybrid WSN setup of low and high precision nodes is examined. Simulations showed that the greedy algorithm used for scheduling the nodes, realized a network that is more resilient to individual node failure. Moreover, the use of more affordable nodes stroke a better trade-off between deployment feasibility and precision
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