bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of a trigonometric approach to the regionalization of precipitation for a complex small‐scale terrain in a GIS environment
Authors: Franke Johannes , Häntzschel Janet , Goldberg Valeri , Bernhofer Christian 
Published: August 2008

AbstractTo regionalize precipitation on a small‐scale, complex, low mountain range terrain, trigonometric relationships were constructed in a geographical information system (GIS) environment using a digital elevation model (DEM). The large‐scale orographic effect and small‐scale windward and leeward effects on precipitation were recorded and quantified using a grid‐based combination of a terrain vector (slope angle, aspect) with a wind vector (wind direction, speed). This was based on the parameterization of a longer‐term wind‐precipitation distribution. Both effects were mapped for the meso‐scale Weißeritz River catchment in the Ore Mountains of Germany, using an estimate of spatially distributed slope precipitation. It was shown that the small‐scale windward and leeward effects modify the larger‐scale orographic effect spatially. It was determined that both the amount and the phase of the small‐scale windward and leeward effect correlates with the height above sea level. During the 1971–2003 growing seasons the amount of precipitation increased by 4% per 100 m, and for the 1971–2000 statistically heavy precipitation (SHP) (duration: 24 h, return period: 100 years) the increase was 1% per 100 m. The phase shift occurred because the main wind veered south‐west to west to north‐west with elevation increase, and it was more pronounced for mean than for heavy precipitation. Spatial slope precipitation was estimated to be within the 390–715 mm range for mean adjusted precipitation and 100–140 mm for SHP. The maximum of the windward and leeward effect on precipitation amounts to ± 25% of fallen precipitation. Copyright © 2008 Royal Meteorological Society
Clinical outcomes from a physiotherapist‐led intra‐articular hyaluronic acid injection clinic
Authors: Birchall Dolina , Ismail A. Mobeen , Peat George 
Published: August 2008

AbstractObjectives: To describe the clinical course of knee osteoarthritis following a single course of intra‐articular hyaluronic acid (HA) injection clinic, and specifically to explore treatment withdrawal.Design: Prospective consecutive case series with follow‐up, set in an innovative physiotherapist‐led clinic, based in a hospital orthopaedic surgery department.Participants: A total of 100 patients with knee osteoarthritis referred to the clinic received a single course of five injections of Hyalgan®. Patients were followed up in clinic at five, 13, 26 and 52 weeks. The primary outcome measures were Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) Likert 3.0 pain (0–20) and physical function (0–68) scores. In addition, at 13 and 26 weeks, patients were reviewed independently by an orthopaedic surgeon, with the option of withdrawing for alternative management those patients who had not responded.Results: Ninety (90%) patients were successfully followed to study endpoint. Improvements were seen at five weeks and, to a lesser extent, at 13 weeks (mean reduction in WOMAC pain at 13 weeks = 1.3; 95% confidence interval [CI] 0.5, 2.0; mean reduction in WOMAC Physical Function at 13 weeks = 5.6; 95% CI 3.0, 8.1). Of 34 treatment withdrawals, most had returned to baseline levels by 13 weeks. The remaining 56 patients maintained improvements up to 52 weeks, although the pattern of outcome was highly variable between individuals. Withdrawals and non‐responders had higher initial pain severity.Conclusions: Physiotherapist‐led intra‐articular HA clinics are feasible. Clinical outcomes for individual patients are highly heterogeneous up to one year after injections. Patients with initially high levels of pain may be less likely to benefit. Copyright © 2008 John Wiley & Sons, Ltd.
Anxiety disorders: a comprehensive review of pharmacotherapies
Authors: Hoffman Ellen J. , Mathew Sanjay J. 
Published: August 2008

AbstractThis article reviews the evidence from randomized, placebo‐controlled trials and meta‐analyses of pharmacological treatments of the following anxiety disorders: generalized anxiety disorder, panic disorder, social anxiety disorder, and post–traumatic stress disorder. There is evidence from multiple randomized, placebo‐controlled trials to support the use of selective serotonin reuptake inhibitors as first‐line pharmacotherapy in these disorders, and a number of the selective serotonin reuptake inhibitors have received US Food and Drug Administration approval for these indications. Serotonin‐norepinephrine reuptake inhibitors are now emerging as first‐line treatments for these anxiety disorders alongside the selective serotonin reuptake inhibitors and have been US Food and Drug Administration–approved for some of these indications as well. Benzodiazepines are also effective treatments for anxiety disorders, and although this medication class has the advantage of a rapid onset of action, their use is limited by their potential for abuse and lack of antidepressant properties. In addition to reviewing the clinical trials that have investigated the anxiolytic effects of these commonly used medications, we review the evidence for novel uses of other agents, including anticonvulsants and atypical antipsychotics, in anxiety disorders. Mt Sinai J Med 75:247–262, 2008. © 2008 Mount Sinai School of Medicine
Major depression: emerging therapeutics
Authors: Sen Srijan , Sanacora Gerard 
Published: August 2008

AbstractThe first effective antidepressants, monoamine oxidase inhibitors and tricyclic antidepressants, were identified 50 years ago, largely through serendipity. These medications were found to improve mood in a little more than half of depressed patients after a few weeks of chronic use. Almost all antidepressants prescribed today were developed through minor modifications of these original antidepressants and, like monoamine oxidase inhibitors and tricyclic antidepressants, act primarily through monoaminergic mechanisms. Although there have been improvements in side‐effect profiles and overdose toxicity, these newer medications have not provided substantial advances in the efficacy and speed of the antidepressant effect for patients. Over the last 2 decades, our understanding of the neurobiology underlying depression has expanded exponentially. Given this expansion, we may be nearing an inflection point in antidepressant drug development, at which useful medicines will be designed through a rational understanding of the biological systems. In this review, we discuss the biological basis and preclinical and clinical evidence for a series of promising classes of antidepressants developed primarily out of a pathophysiologically informed approach. Mt Sinai J Med 75:203–224, 2008. © 2008 Mount Sinai School of Medicine
Neurostimulatory therapeutics in management of treatment‐resistant depression with focus on deep brain stimulation
Authors: Dumitriu Dani , Collins Kate , Alterman Ron , Mathew Sanjay J. 
Published: August 2008

AbstractTreatment‐resistant depression continues to pose a major medical challenge, as up to one‐third of patients with major depressive disorder fail to have an adequate response to standard pharmacotherapies. An improved understanding of the complex circuitry underlying depressive disorders has fostered an explosion in the development of new, nonpharmacological approaches. Each of these treatments seeks to restore normal brain activity via electrical or magnetic stimulation. In this article, the authors discuss the ongoing evolution of neurostimulatory treatments for treatment‐resistant depression, reviewing the methods, efficacy, and current research on electroconvulsive therapy, repetitive transcranial magnetic stimulation, magnetic seizure therapy, focal electrically administered stimulated seizure therapy, transcranial direct current stimulation, chronic epidural cortical stimulation, and vagus nerve stimulation. Special attention is given to deep brain stimulation, the most focally targeted approach. The history, purported mechanisms of action, and current research are outlined in detail. Although deep brain stimulation is the most invasive of the neurostimulatory treatments developed to date, it may hold significant promise in alleviating symptoms and improving the quality of life for patients with the most severe and disabling mood disorders. Mt Sinai J Med 75:263–275, 2008. © 2008 Mount Sinai School of Medicine
Type 1 diabetes mellitus: primary, secondary, and tertiary prevention
Authors: Bollyky Jennifer , Sanda Srinath , Greenbaum Carla J. 
Published: August 2008

AbstractWe have entered the era of clinical trials to prevent type 1 diabetes mellitus (T1DM). Before 1922, when insulin was first given to a patient with diabetes, a diagnosis of T1DM was considered a death sentence. Advances in treatment for subjects with diabetes are not yet sufficient to prevent the deleterious impact of diabetes on both day‐to‐day activities and the early morbidity and mortality still associated with the disease. We now understand a great deal about blood glucose regulation and potential health complications associated with long‐term T1DM, but the mystery of why, or the pathogenesis of this devastating disease, remains elusive. Great strides toward unraveling this mystery have been made over the past several decades. Even without definitive answers, we are moving from the period of discovery and animal research to the era of clinical trials. In this review, we wish to convey the palpable excitement in the field. It is time to determine if we can safely change the course of T1DM. Mt Sinai J Med 75:385–397, 2008. © 2008 Mount Sinai School of Medicine
Toward a cell‐based cure for diabetes: advances in production and transplant of beta cells
Authors: Claiborn Kathryn C. , Stoffers Doris A. 
Published: August 2008

AbstractType 1 diabetes results from autoimmune destruction of the insulin‐producing beta cells of the pancreatic islets of Langerhans. Although developments in exogenous insulin therapy have greatly improved clinical outcomes in patients with diabetes, the ability of the pancreatic beta cell to exquisitely regulate the delivery of insulin and maintain normal levels of blood glucose is still far superior to what can be achieved by external delivery of insulin. As a result, the majority of patients with type 1 diabetes still experience the complications of chronic hyperglycemia or serious and potentially life‐threatening hypoglycemia. The shortcomings of medical therapy have driven research toward more direct approaches of beta cell replacement. Indeed, the specificity of beta cell loss in type 1 diabetes makes this disease a particularly attractive candidate for cell‐based therapies. In order for significant progress to be made, however, a thorough understanding of beta cell biology and more broadly islet biology is necessary. This review addresses recent advances in developmental biology that have expanded our understanding of islet cell differentiation, assesses the promise and limitations of islet transplantation, and discusses the future of alternative sources of beta cells, including directed differentiation of stem cells, replication of adult beta cells, and transdifferentiation of nonislet cells to a beta cell fate. Mt Sinai J Med 75:362–371, 2008. © 2008 Mount Sinai School of Medicine
Dynamic capacity reservation and due date quoting in a make‐to‐order system
Authors: Pibernik Richard , Yadav Prashant 
Published: August 2008

AbstractWe consider a make‐to‐order manufacturer facing random demand from two classes of customers. We develop an integrated model for reserving capacity in anticipation of future order arrivals from high priority customers and setting due dates for incoming orders. Our research exhibits two distinct features: (1) we explicitly model the manufacturer's uncertainty about the customers' due date preferences for future orders; and (2) we utilize a service level measure for reserving capacity rather than estimating short and long term implications of due date quoting with a penalty cost function.We identify an interesting effect (“t‐pooling”) that arises when the (partial) knowledge of customer due date preferences is utilized in making capacity reservation and order allocation decisions. We characterize the relationship between the customer due date preferences and the required reservation quantities and show that not considering the t‐pooling effect (as done in traditional capacity and inventory rationing literature) leads to excessive capacity reservations. Numerical analyses are conducted to investigate the behavior and performance of our capacity reservation and due date quoting approach in a dynamic setting with multiple planning horizons and roll‐overs. One interesting and seemingly counterintuitive finding of our analyses is that under certain conditions reserving capacity for high priority customers not only improves high priority fulfillment, but also increases the overall system fill rate. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008
An optimal critical level policy for inventory systems with two demand classes
Authors: Möllering Karin T. , Thonemann Ulrich W. 
Published: August 2008

AbstractTraditional inventory systems treat all demands of a given item equally. This approach is optimal if the penalty costs of all customers are the same, but it is not optimal if the penalty costs are different for different customer classes. Then, demands of customers with high penalty costs must be filled before demands of customers with low penalty costs. A commonly used inventory policy for dealing with demands with different penalty costs is the critical level inventory policy. Under this policy demands with low penalty costs are filled as long as inventory is above a certain critical level. If the inventory reaches the critical level, only demands with high penalty costs are filled and demands with low penalty costs are backordered. In this article, we consider a critical level policy for a periodic review inventory system with two demand classes. Because traditional approaches cannot be used to find the optimal parameters of the policy, we use a multidimensional Markov chain to model the inventory system. We use a sample path approach to prove several properties of this inventory system. Although the cost function is not convex, we can build on these properties to develop an optimization approach that finds the optimal solution. We also present some numerical results. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008
DEA models for two‐stage processes: Game approach and efficiency decomposition
Authors: Liang Liang , Cook Wade D. , Zhu Joe 
Published: August 2008

AbstractData envelopment analysis (DEA) is a method for measuring the efficiency of peer decision making units (DMUs). This tool has been utilized by a number of authors to examine two‐stage processes, where all the outputs from the first stage are the only inputs to the second stage. The current article examines and extends these models using game theory concepts. The resulting models are linear, and imply an efficiency decomposition where the overall efficiency of the two‐stage process is a product of the efficiencies of the two individual stages. When there is only one intermediate measure connecting the two stages, both the noncooperative and centralized models yield the same results as applying the standard DEA model to the two stages separately. As a result, the efficiency decomposition is unique. While the noncooperative approach yields a unique efficiency decomposition under multiple intermediate measures, the centralized approach is likely to yield multiple decompositions. Models are developed to test whether the efficiency decomposition arising from the centralized approach is unique. The relations among the noncooperative, centralized, and standard DEA approaches are investigated. Two real world data sets and a randomly generated data set are used to demonstrate the models and verify our findings. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008
Scheduling multiple products on parallel machines with setup costs
Authors: Krasik Vladimir , Leung Joseph , Pinedo Michael , Zhang Jiawei 
Published: August 2008

AbstractWe consider a class of production scheduling models with m identical machines in parallel and k different product types. It takes a time pi to produce one unit of product type i on any one of the machines. There is a demand stream for product type i consisting of ni units with each unit having a given due date. Before a machine starts with the production of a batch of products of type i a setup cost c is incurred. We consider several different objective functions. Each one of the objective functions has three components, namely a total setup cost, a total earliness cost, and a total tardiness cost. In our class of problems we find a relatively large number of problems that can be solved either in polynomial time or in pseudo‐polynomial time. The polynomiality or pseudo‐polynomiality is achieved under certain special conditions that may be of practical interest; for example, a regularity pattern in the string of due dates combined with earliness and tardiness costs that are similar for different types of products. The class of models we consider includes as special cases discrete counterparts of a number of inventory models that have been considered in the literature before, e.g., Wagner and Whitin (Manage Sci 5 (1958), 89–96) and Zangwill (Oper Res 14 (1966), 486–507; Manage Sci 15 (1969), 506–527). © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008
A novel modeling approach for express package carrier planning
Authors: Root Sarah , Cohn Amy 
Published: August 2008

AbstractExpress package carrier networks have large numbers of heavily‐interconnected and tightly‐constrained resources, making the planning process difficult. A decision made in one area of the network can impact virtually any other area as well. Mathematical programming therefore seems like a logical approach to solving such problems, taking into account all of these interactions. The tight time windows and nonlinear cost functions of these systems, however, often make traditional approaches such as multicommodity flow formulations intractable. This is due to both the large number of constraints and the weakness of the linear programming (LP) relaxations arising in these formulations. To overcome these obstacles, we propose a model in which variables represent combinations of loads and their corresponding routings, rather than assigning individual loads to individual arcs in the network. In doing so, we incorporate much of the problem complexity implicitly within the variable definition, rather than explicitly within the constraints. This approach enables us to linearize the cost structure, strengthen the LP relaxation of the formulation, and drastically reduce the number of constraints. In addition, it greatly facilitates the inclusion of other stages of the (typically decomposed) planning process. We show how the use of templates, in place of traditional delayed column generation, allows us to identify promising candidate variables, ensuring high‐quality solutions in reasonable run times while also enabling the inclusion of additional operational considerations that would be difficult if not impossible to capture in a traditional approach. Computational results are presented using data from a major international package carrier. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008
Replacing nonidentical vital components to extend system life
Authors: Shechter Steven M. , Bailey Matthew D. , Schaefer Andrew J. 
Published: August 2008

AbstractWe consider a system that depends on a single vital component. If this component fails, the system life will terminate. If the component is replaced before its failure then the system life may be extended; however, there are only a finite number of spare components. In addition, the lifetimes of these spare components are not necessarily identically distributed. We propose a model for scheduling component replacements so as to maximize the expected system survival. We find the counterintuitive result that when comparing components' general lifetime distributions based on stochastic orderings, not even the strongest ordering provides an a priori guarantee of the optimal sequencing of components. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008
Competitive location and capacity decisions for firms serving time‐sensitive customers
Authors: Kwasnica Anthony M. , Stavrulaki Euthemia 
Published: August 2008

AbstractIn this article we explore how two competing firms locate and set capacities to serve time‐sensitive customers. Because customers are time‐sensitive, they may decline to place an order from either competitor if their expected waiting time is large. We develop a two‐stage game where firms set capacities and then locations, and show that three types of subgame perfect equilibria are possible: local monopoly (in which each customer is served by a single firm, but some customers may be left unserved), constrained local monopoly (in which firms serve the entire interval of customers but do not compete with each other), and constrained competition (in which firms also serve the entire interval of customers, but now compete for some customers). We perform a comparative statics analysis to illustrate differences in the equilibrium behavior of a duopolist and a coordinated monopolist. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008
Minimising the effects of bolus dispersion in bolus‐tracking MRI
Authors: Willats L. , Connelly A. , Calamante F. 
Published: August 2008

AbstractBolus‐tracking perfusion measurements in patients with vascular abnormalities are often unreliable, because delay and/or dispersion of the bolus within the vessels distorts the measured arterial input function (AIF). Erroneous measurements of perfusion can be identified by examining the measured response function, the shape of which is determined by both the tissue and arterial retention. In this work, an accurate response function is extracted by combining maximum‐likelihood expectation‐maximisation deconvolution, regularised using an oscillation index, with subsequent wavelet thresholding. Simulations show that this method recovers both the smooth‐dispersed and the sharp‐delayed response functions. This enables regions where the bolus is delayed and/or dispersed to be identified when the methodology is applied to data from patients with vascular abnormalities. Simulations also demonstrate robust and accurate perfusion estimates when there is no bolus delay and/or dispersion. The presence of delay and/or dispersion in the response function suggests that the perfusion measurements are erroneous, and that the global AIF is an inaccurate approximation to the true AIF in these regions. Perfusion measurements are corrected within the affected regions by defining a regional AIF from the independent component analysis of the dynamic susceptibility contrast MRI data. The regional AIF is shown to remove the delay and dispersion, improving the accuracy of the perfusion maps. Copyright © 2008 John Wiley & Sons, Ltd.