bluuebunny/crossref_metadata_2025 huggingface dataset:
Boundedly rational equilibrium and risk premium
Authors: He Xue‐Zhong , Shi Lei
Published: April 2011

When people agree to disagree, the impact of the disagreement among agents on the market is the main concern of this paper. With the standard mean variance framework, this paper considers a market of two risky assets and two agents who have different preference and disagreement about the mean and variance/covariance of the asset returns. By constructing a consensus belief, the paper develops an concept of boundedly rational equilibrium (BRE) to characterize the market equilibrium and examines explicitly the impact of heterogeneity on the market equilibrium and risk premium when the disagreements among the two agents are mean preserved spreads of a benchmark homogeneous belief. It shows that, in market equilibrium, the biased mean preserved spreads in beliefs among the two agents have significant impact on the risk premium of the risky assets and market portfolio, and adding a riskless asset in the market magnifies the impact of the heterogeneity on the market. The results show that both optimism/pessemism and confidence/doubt can increase the market risk premium and reduce the riskfree rate.
HUMAN ENHANCEMENT AND SEXUAL DIMORPHISM
Authors: SPARROW ROB
Published: April 2011

I argue that the existence of sexual dimorphism poses a profound challenge to those philosophers who wish to deny the moral significance of the idea of ‘normal human capacities’ in debates about the ethics of human enhancement. The biological sex of a child will make a much greater difference to their life prospects than many of the genetic variations that the philosophical and bioethical literature has previously been concerned with. It seems, then, that bioethicists should have something to say about the choice between a male and a female embryo. Either, 1) parents have reason to choose boys over girls; (2) parents have reason to choose girls over boys; or, (3) parents have neither reason to choose girls over boys nor reason to choose boys over girls. Embracing either of the first two alternatives has strongly counterintuitive – and arguably morally repugnant – consequences. To motivate the third option we must either make reference to the idea of ‘normal human capacities’ or argue that parents should consider the interests of society when thinking about what sort of children they should bring into the world – an implication that should be extremely controversial in debates about the ‘new eugenics’. I conclude, then, that the idea of ‘normal human capacities’ is properly crucial to reasoning about the ethics of shaping future persons.
CULTURAL HISTORY, THE POSSIBLE, AND THE PRINCIPLE OF PLENITUDE1
Authors: SALMI HANNU
Published: April 2011

Cultural historical research has deliberately challenged “historical realism,” the view that history is comprised entirely of observable actions that actually occurred, and instead has emphasized the historical significance of thoughts, emotions, and representations; it has also focused on the invisible, the momentary, and the perishable. These latter elements introduce the notion of the possible in history. This article examines the ways in which cultural history has approached the notion of the possible, as well as the methodological and theoretical implications of this approach. Its chief claim is that the idea of possibility is fundamental for the concept of culture and ineliminable from its historical study.

The question of possibility is present in multiple ways in the study of history; it is important to distinguish among different levels of possibility. The possible may mean, for instance, what it is possible for historians to know about the past, or the possibilities open to historical agents themselves, or, indeed, the possibilities they perceived themselves as having even if these seem impossible from the point of view of the historian. The article starts with the first aspect and moves on toward the possibilities that existed in the past world either in fact or in the minds of those in the past.

The article argues that the study of past cultures always entails the mapping of past possibilities. The first strand of the essay builds on the metaphor of the black hole and intends to solve one of the central problems faced by cultural historians, namely, how to access the horizon of the people of the past, their experience of their own time, especially when the sources remain silent. The second, more speculative strand builds on the notion of plenitude and is designed to open up avenues for further discussion about the concept of culture in particular.
1. DECENTERING HISTORY: LOCAL STORIES AND CULTURAL CROSSINGS IN A GLOBAL WORLD
Authors: DAVIS NATALIE ZEMON
Published: April 2011

This essay was first presented at the 2010 Ludwig Holberg Prize Symposium in Bergen, Norway, where I, as the prize recipient, was asked to describe my work and its import for our period of globalization. The essay first traces the interconnected processes of “decentering” history in Western historiography in the half century after World War II: the move to working people and “subaltern classes”; to women and gender; to communities defined by ethnicity and race; to the study of non‐Western histories and world or global history, in which the European trajectory is only one of several models. Can the historian hold onto the subjects of “decentered” social and cultural history, often local and full of concrete detail, and still address the perspectives of global history? To suggest an answer to this question, I describe my own decentering path from work on sixteenth‐century artisans in the 1950s to recent research on non‐European figures such as the Muslim “Leo Africanus” (Hasan al‐Wazzan). I then offer two examples in which concrete cases can serve a global perspective. One is a comparison of the literary careers of Ibn Khaldun and Christine de Pizan in the scribal cultures on either side of the Mediterranean in the late fourteenth and early fifteenth centuries. The other is the transmission and transformation of practices of divination, healing, and detection from Africa to the slave communities of Suriname in the seventeenth and eighteenth centuries.
4. MEDITERRANEAN HISTORY AS GLOBAL HISTORY
Authors: ABULAFIA DAVID
Published: April 2011

Mediterranean history, and the history of other closed seas, is seen here as the experience of those who traversed the sea and arrived as decentered aliens on the other side. Mainly these have been men, with merchants generally as pioneers who introduced the goods, ideas, and religion of one region to another. From antiquity onwards, port cities such as Carthage, Alexandria, Smyrna, and Livorno acted as links among the three continents facing the Mediterranean, and visitors from other lands were sometimes free to roam, sometimes ghettoized.
1. CONSTRUCTING A SELECTIONIST PARADIGM
Authors: Stuart‐Fox Martin
Published: April 2011

In his latest contribution to the application of Darwinian evolutionary thinking to the social sciences, W. G. Runciman conceives of human behavior as resulting from three levels of selection—biological, cultural, and social. These give rise, respectively, to evoked, acquired, and imposed patterns of behavior. The biological level is hardly controversial, but to draw a distinction between separate cultural and social selective processes is more problematic. Runciman takes memes to be the variants competitively selected at the cultural level and the practices constituting rule‐governed roles to be the variants competitively selected at the social level—thus preserving separate spheres of research for anthropology and sociology. It is not clear, however, what drives cultural and social evolution. Nor are the three levels theoretically well integrated. The book's strength lies in the numerous examples provided of how the application of selectionist theory illuminates and enriches sociological and historical explanations and contributes to the construction of historical narrative.
CALIFORNIA IRREDENTA
Authors: CHYTRY JOSEF
Published: April 2011

Kevin Starr's Golden Dreams is the culmination to some forty years of scholarship on the unfolding theme of a “California Dream,” that imaginal component to the growth of the self‐identity and increasing international economic power of the most populous state in the American Union. Indeed, the period 1950–1963 that the book meticulously covers forms in many ways the most imposing manifestation of that Dream. This essay reviews the central features of Starr's account, particularly the infrastructural foundations in transportation, water supply, and higher education realized by a triumvirate of California governors, both Republican and Democrat, who regarded themselves as nonpartisan members of the “Party of California”; the expansion of California's major cities: Los Angeles, San Diego, and San Francisco; the characteristics of the Silent Generation and the culture of “cool Jazz” that dominated the period; as well as the rise of dissident elements among environmentalists, minorities, and Beats, that foretold the protest period of the 1960s. This essay then asks whether Starr has avoided the larger implications of his own narrative that California from this period on had become in most respects a putative nation‐state in its own right. From the global impact of its major media industry—Hollywood—to the continued advances of its economic clout throughout the rest of the century as at times the fifth largest economic entity in the world, California may need to be increasingly regarded as a world civilization in itself rather than as a regional civilization to which Starr's historical narrative has so far constricted it.
BETWEEN GENOCIDE AND “GENOCIDE”
Authors: Lang Berel
Published: April 2011

The two books discussed here join a current pushback against the concept (thus also against claims for the historical occurrence) of genocide. Nichanian focuses on the Armenian “Aghed” (“Catastrophe”), inferring from his view of that event's undeniability that “genocide is not a fact” (since all facts are deniable). May's critique assumes that groups don't really—“objectively”—exist, as (by contrast) individuals do; thus, genocide—group murder—also has an “as if” quality so far as concerns the group victimized. On the one hand, then, uniqueness and sacralization; on the other hand, reductionism and diffusion. Alas, the historical and moral claims in “defense” of both genocide and “genocide” survive.
FORECASTING THE YIELD CURVE USING PRIORS FROM NO‐ARBITRAGE AFFINE TERM STRUCTURE MODELS*
Authors: Carriero Andrea
Published: April 2011

I propose a strategy for forecasting the term structure of interest rates that may produce significant gains in predictive accuracy. The key idea is to use the restrictions implied by Gaussian, no‐arbitrage, affine term structure models on a vector autoregression as prior information instead of imposing the restrictions dogmatically. This allows us to account for possible model misspecification. We use the proposed method to forecast a system of five U.S. yields up to 12 months ahead, and we find it provides significant gains in forecast accuracy.
A THEORY OF MIGRATION AS A RESPONSE TO OCCUPATIONAL STIGMA*
Authors: Fan C. Simon , Stark Oded
Published: April 2011

A theory is developed of labor migration that is prompted by a desire to avoid “social humiliation.” In a general‐equilibrium framework, it is shown that as long as migration can reduce humiliation sufficiently, migration will occur even between two identical economies. Migration increases the number of individuals who choose to perform degrading jobs and consequently, migration lowers the price of the good produced in the sector that is associated with low social status. Moreover, the greater an individual's aversion to performing degrading jobs, the more likely it is that he will experience a welfare gain when the economy opens up.
BARRIERS TO ENTRY AND DEVELOPMENT*
Authors: Herrendorf Berthold , Teixeira Arilton
Published: April 2011

We ask whether barriers to entry are a quantitatively important reason for the income gap between developing countries and the United States. We develop a tractable general equilibrium model that captures the effects of barriers to entry and the other main distortions typically considered in the development literature. We carry our model to the data and ask it to match the main development facts from the Penn World Table. We find that this requires large barriers to entry in developing countries, which account for about half of the income gap with the United States.
The measurement of lactate threshold in resistance exercise: a comparison of methods
Authors: de Sousa Nuno Manuel Frade , Magosso Rodrigo Ferro , Pereira Guilherme Borges , Leite Richard Diego , Arakelian Vivian Maria , Montagnolli Arlindo Neto , Perez Sérgio Andrade , Baldissera Vilmar
Published: April 2011

Resistance incremental tests (IT) make it possible to determine critical metabolic and cardiovascular changes, such as the lactate threshold (LT). Different methods are frequently used to improve the exactness of LT identification. The objective of the study was to identify LT by four different methods (visual inspection, log–log, algorithmic adjustment and QLac) during resistance exercise and to evaluate which methods present more precision. Twelve men performed a maximal IT on the leg press at relative intensities of 10%, 20%, 25%, 30%, 35%, 40%, 50%, 60%, 70%, 80% and 90% of 1RM with 1‐min stages. During the 2‐min interval between stages, capillary blood was collected for blood lactate analysis. LT was detected using each of the four methods. The intensity of LT by visual inspection method was 26·9 (5·2)% of 1RM, adjustment algorithmic method was 27·8 (3·6)% of 1RM, log–log method was 23·3 (3·5)% of 1RM and QLac method was 31·6 (9·8)% of 1RM, with significant difference only between log–log and QLac methods. Bland and Altman analysis shows better concordance for visual inspection versus adjustment algorithmic methods. The visual inspection, algorithmic and log–log methods detected the LT at the same intensity. The mathematical models, specially the algorithmic method, provide more precision.
The soothing effects of forgiveness on victims' and perpetrators' blood pressure
Authors: HANNON PEGGY A. , FINKEL ELI J. , KUMASHIRO MADOKA , RUSBULT CARYL E.
Published: April 2011

A laboratory experiment tested whether conciliatory behavior predicts lower blood pressure following spouses' discussion of a recent marital transgression. Sixty‐eight married couples discussed unresolved transgressions—with random assignment determining whether the husband or the wife was in the victim role—and then rated victim and perpetrator conciliatory behavior (with the former akin to forgiveness and the latter akin to amends) while watching a videotape of their just‐completed discussion. Participants' blood pressure was measured 40 min later. Actor–partner interdependence modeling analyses revealed that victim conciliatory behavior during the discussion predicted not only lower victim blood pressure but also lower perpetrator blood pressure after the discussion. Perpetrator conciliatory behavior during the discussion was not associated with victim or perpetrator blood pressure.
Cannabinoid CB1 receptors transactivate multiple receptor tyrosine kinases and regulate serine/threonine kinases to activate ERK in neuronal cells
Authors: Dalton George D , Howlett Allyn C
Published: April 2011

BACKGROUND AND PURPOSE

Signalling networks that regulate the progression of cannabinoid CB1 receptor‐mediated extracellular signal‐regulated kinase (ERK) activation in neurons are poorly understood. We investigated the cellular mechanisms involved in CB1 receptor‐stimulated ERK phosphorylation in a neuronal cell model.

EXPERIMENTAL APPROACH

Murine N18TG2 neuronal cells were used to analyse the effect of specific protein kinase and phosphatase inhibitors on CB1 receptor‐stimulated ERK phosphorylation. The LI‐COR In Cell Western assay and immunoblotting were used to measure ERK phosphorylation.

KEY RESULTS

The time‐course of CB1 receptor‐stimulated ERK activation occurs in three phases that are regulated by distinct cellular mechanisms in N18TG2 cells. Phase I (0–5 min) maximal ERK phosphorylation is mediated by CB1 receptor‐stimulated ligand‐independent transactivation of multiple receptor tyrosine kinases (RTKs). Phase I requires Gi/oβγ subunit‐stimulated phosphatidylinositol 3‐kinase activation and Src kinase activation and is modulated by inhibition of cAMP‐activated protein kinase A (PKA) levels. Src kinase activation is regulated by the protein tyrosine phosphatases 1B and Shp1. The Phase II (5–10 min) rapid decline in ERK phosphorylation involves PKA inhibition and serine/threonine phosphatase PP1/PP2A activation. The Phase III (>10 min) plateau in ERK phosphorylation is mediated by CB1 receptor‐stimulated, ligand‐independent, transactivation of multiple RTKs.

CONCLUSIONS AND IMPLICATIONS

The complex expression of CB1 receptor‐stimulated ERK activation provides cellular selectivity, modulation of sensitivity to agonists, and coincidence detection with RTK signalling. RTK and PKA pathways may provide routes to novel CB1‐based therapeutic interventions in the treatment of addictive disorders or neurodegenerative diseases.

LINKED ARTICLES This article is part of a themed section on Cannabinoids in Biology and Medicine. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue‐8. To view Part I of Cannabinoids in Biology and Medicine visit http://dx.doi.org/10.1111/bph.2011.163.issue‐7
Cyclopeptide RA‐V inhibits angiogenesis by down‐regulating ERK1/2 phosphorylation in HUVEC and HMEC‐1 endothelial cells
Authors: Yue Grace GL , Fan Jun‐Ting , Lee Julia KM , Zeng Guang‐Zhi , Ho Tina WF , Fung Kwok‐Pui , Leung Ping‐Chung , Tan Ning‐Hua , Lau Clara BS
Published: April 2011

BACKGROUND AND PURPOSEAnti‐angiogenic agents have recently become one of the major adjuvants for cancer therapy. A cyclopeptide, RA‐V, has been shown to have anti‐tumour activities. Itsin vitroanti‐angiogenic activities were evaluated in the present study, and the underlying mechanisms were also assessed.

EXPERIMENTAL APPROACHTwo endothelial cell lines, human umbilical vein endothelial cells (HUVEC) and human microvascular endothelial cells (HMEC‐1), were used. The effects of RA‐V on the proliferation, cell cycle phase distribution, migration, tube formation and adhesion were assessed. Western blots and real‐time PCR were employed to examine the protein and mRNA expression of relevant molecules.

KEY RESULTSRA‐V inhibited HUVEC and HMEC‐1 proliferation dose‐dependently with IC50values of 1.42 and 4.0 nM respectively. RA‐V inhibited migration and tube formation of endothelial cells as well as adhesion to extracellular matrix proteins. RA‐V treatment down‐regulated the protein and mRNA expression of matrix metalloproteinase‐2. Regarding intracellular signal transduction, RA‐V interfered with the activation of ERK1/2 in both cell lines. Furthermore, RA‐V significantly decreased the phosphorylation of JNK in HUVEC whereas, in HMEC‐1, p38 MAPK was decreased.

CONCLUSIONS AND IMPLICATIONSRA‐V exhibited anti‐angiogenic activities in HUVEC and HMEC‐1 cell lines with changes in function of these endothelial cells. The underlying mechanisms of action involved the ERK1/2 signalling pathway. However, RA‐V may regulate different signalling pathways in different endothelial cells. These findings suggest that RA‐V has the potential to be further developed as an anti‐angiogenic agent.
How to Optimize Drug Delivery in Renal Replacement Therapy
Authors: Awdishu Linda , Bouchard Josée
Published: April 2011

Drug dosing in the setting of acute kidney injury (AKI) is complicated by several factors such as pharmacokinetic changes in renal failure, inaccuracy of renal estimating equations in this setting, lack of therapeutic drug monitoring capability for most drugs, and use of extracorporeal renal replacement. Pharmacokinetic changes include decreases in protein binding and drug metabolism. Renal estimating equations most often overestimate renal clearance in AKI. Additionally, it is well recognized that some drugs are significantly cleared by extracorporeal therapy. Patients with AKI are therefore at risk for adverse outcomes of drug therapy. It has been reported that approximately half of patients with reduced renal clearance receive drug doses that are 2.5 times higher than the recommended maximum dose. To ensure efficacy and prevent toxicity, therapeutic drug monitoring is highly recommended. However, in the absence of drug monitoring, adequate concentrations can only be inferred from clinical response. A clinician must weigh the risks and benefits of possible over‐dosing or under‐dosing based on the therapeutic index of the drug and the clinical situation. This article will review the important factors to consider for drug dosing in patients with AKI receiving continuous renal replacement therapy and sustained low‐efficiency dialysis.
Renal Replacement Therapy in Special Settings: Extracorporeal Support Devices in Liver Failure
Authors: Cerdá Jorge , Tolwani Ashita , Gibney Noel , Tiranathanagul Khajohn
Published: April 2011

Hepatorenal syndrome (HRS) type I is a unique form of acute kidney injury resulting from renal vasoconstriction in the setting of systemic and splanchnic arterial vasodilation in patients with end‐stage liver disease. The only definitive treatment currently available is liver or liver–kidney transplantation. The goal of extracorporeal support (ECS) systems in HRS is to bridge eligible liver failure patients to transplantation or functional recovery by means of detoxification, assistance with biosynthesis of key metabolic products, and regulation of inflammation. ECS systems in liver disease can be divided into two broad categories: cell‐based and noncell‐based systems. While cell‐based systems aim to provide functions similar to those of normal hepatocytes, noncell‐based systems do not incorporate tissue; they provide detoxification utilizing membranes and adsorbents. There are no standard guidelines for the application of ECS systems. Published studies are too small and show considerable differences in primary indication, primary endpoint, and treatment protocols for “intervention” and “standard” treatment groups. This article reviews the available evidence regarding the optimal use of ECS devices in HRS, makes evidence‐based practice recommendations, and delineates key questions for future studies.
Management of Complications in Renal Replacement Therapy
Authors: Shingarev Roman , Wille Keith , Tolwani Ashita
Published: April 2011

Renal replacement therapies (RRTs) are frequently employed for treatment of patients suffering from acute kidney injury in the intensive care unit (ICU). Multiple modalities of RRT are currently available. These include intermittent hemodialysis, continuous renal replacement therapies, and hybrid therapies, such as sustained low‐efficiency dialysis. Because of the high complexity of ICU patients, physicians must be aware of the limitations and complications of both intermittent and continuous dialysis modalities that can contribute to patient morbidity and mortality. In this article, we highlight the recognized complications of RRTs and the treatment approach to these complications.
Biomarker Strategies to Predict Need for Renal Replacement Therapy in Acute Kidney Injury
Authors: Cruz Dinna N. , de Geus Hilde R. , Bagshaw Sean M.
Published: April 2011

The early detection and diagnosis of acute kidney injury (AKI) with the standardization of novel kidney‐injury‐specific biomarkers is one of the highest research priorities in nephrology. Accordingly, the majority of studies of novel AKI biomarkers have focused on the early diagnosis of AKI using serum creatinine‐based definitions as the gold standard. However, another potential application of kidney‐injury‐specific biomarkers is for guiding decisions on when to initiate renal replacement therapy (RRT). The purpose of this review is to summarize recent findings concerning some of the more promising AKI biomarkers on their capacity, either alone or integrated with traditional surrogate measures of kidney injury, for early prediction of whether patients will develop severe AKI requiring RRT. Some studies that have examined neutrophil gelatinase‐associated lipocalin, cystatin‐C, N‐acetyl‐β‐d‐glucosaminidase, kidney injury molecule‐1, and α1‐microglobulin, among others, have suggested that these novel biomarkers have the potential to distinguish patients in whom RRT will be needed. This would imply that these biomarkers may be integrated into clinical decision algorithms and could synergistically improve our current ability to predict worsening AKI and need for RRT. However, published studies have many recognized limitations, which preclude our ability to adapt their findings into clinical practice today. While currently available data are not sufficient to conclude that biomarkers should be used routinely for clinical decision making for RRT initiation, additional data may in the future significantly modify the clinical variability for initiation of RRT, and potentially translate into improved outcomes and cost‐effectiveness. Finally, we propose a potential approach to future biomarker strategies for RRT initiation, integrating these biomarkers with “traditional” clinical factors.
Advances in Pediatric Renal Replacement Therapy for Acute Kidney Injury
Authors: Goldstein Stuart L.
Published: April 2011

The disease spectrum leading to pediatric renal replacement therapy (RRT) provision has broadened over the last decade. In the 1980s, intrinsic renal disease and burns comprised the most common pediatric acute renal failure etiologies; more recent data demonstrate that pediatric acute kidney injury (AKI) most often results from complications of other systemic diseases resulting from the advancements in congenital heart surgery, neonatal care, and bone marrow and solid organ transplantation. In addition, RRT modality preferences to treat critically ill children have shifted from peritoneal dialysis to continuous renal replacement therapy (CRRT) as a result of improvements in CRRT technologies. In this article, we aim to review the pediatric specific causes for RRT provision, emphasizing the emerging practice patterns with respect to modality and timing of treatment. We will focus on the application of different RRT modalities and related outcome of children with AKI who receive RRT.
When Should Renal Replacement Therapy be Initiated for Acute Kidney Injury?
Authors: Macedo Etienne , Mehta Ravindra L.
Published: April 2011

Acute kidney injury (AKI) is now well recognized as an independent risk factor for increased morbidity and mortality particularly when dialysis is needed. Although renal replacement therapy (RRT) has been used in AKI for more than five decades, there is no standard methodology to predict which AKI patients will need dialysis and who will recover renal function without requiring dialysis. The lack of consensus on what parameters should guide the decision to start dialysis has led to a wide variation in dialysis utilization. A contributing factor is the lack of studies in the modern era evaluating the relationship of timing of dialysis initiation and outcomes. Although listed as one of the top priorities in research on AKI, timing of dialysis initiation has not been included as a factor in large, randomized controlled trials in this area. In this review we will discuss the criteria that have been used to define early vs. late initiation in previous studies on dialysis initiation. In addition, we propose a patient‐centered approach to define early and late initiation that could serve as framework for managing patients and for future studies in this area.
Technical Advances in Renal Replacement Therapy
Authors: Ricci Zaccaria , Ronco Claudio
Published: April 2011

Critically ill patients are subject to several risk factors for organ injury: surgical intervention, trauma, rhabdomyolysis, hemodynamic instability, organ hypoperfusion, bacteremia and endotoxemia, sepsis and septic shock. These conditions may cause acute kidney injury (AKI), myocardial dysfunction, liver failure, coagulation abnormalities, acute lung injury (ALI), adult respiratory distress syndrome (ARDS), bone marrow depression, loss of acid/base homeostasis, and finally, brain dysfunction. The resulting picture of multiple organ dysfunction syndrome (MODS) is a lethal clinical entity that is refractory to all therapies in the majority of cases. According to the “humoral theory of sepsis”, soluble substances circulate in blood and participate in the generation of the different disorders of MODS; thus, AKI is not the only clinical disorder observed in intensive care unit (ICU) patients nor is it an isolated syndrome. Current extracorporeal management of such patients focuses mainly on renal replacement therapy (RRT). Nevertheless, in recent years, technical evolution of extracorporeal devices led to the potential creation of multiple organ support therapy (MOST) in order to provide a comprehensive replacement of multiorgan dysfunction: hence, other organs (liver, heart, lungs) and syndromes (abdominal sepsis, septic shock) can today be consistently supported and bridged. The technical advances of extracorporeal equipment, moreover, might allow today the design of a dedicated pediatric RRT device in order to treat patients below 10 kg, with the safety and adequacy standards that are currently granted to the adult population. This review will describe the technical evolution of MOST machines and current literature available on MOST.
Clinical Management of Dialysis Catheter‐Related Bacteremia with Concurrent Exit‐Site Infection
Authors: Sychev Dmitri , Maya Ivan D. , Allon Michael
Published: April 2011

Dialysis catheter‐related bacteremia (CRB) can frequently be treated with systemic antibiotics, in conjunction with an antibiotic lock, in an attempt to salvage the catheter. It is unknown whether CRB associated with an exit‐site infection can be treated with such an approach. We retrospectively queried a prospective, computerized vascular access database, and identified 1436 episodes of CRB, of which 64 cases had a concurrent exit site. The frequency of concurrent exit‐site infection was 9.6% with Staphylococcus epidermidis, 6.1% with Staphylococcus aureus, and only 0.7% with Gram negative CRB (p < 0.001 for Staphylococcus vs. Gram negative rods). Five serious complications (four major sepses and one endocarditis) occurred in 24 patients with S. aureus infection, but none in 32 episodes of S. epidermidis infection (p = 0.01). Catheter survival was significantly shorter in patients with S. aureus infections. The median catheter survival (without infection or dysfunction) was 14 days with S. aureus vs. 30 days with S. epidermidis infection (p = 0.035). In conclusion, concurrent exit‐site infection is seen most commonly in association with Staphylococcal CRB. When the infecting organism is S. epidermidis, attempted salvage with systemic antibiotics and an antibiotic lock is reasonable. However, prompt catheter removal is indicated when the pathogen is S. aureus.
Origin of Neointimal Cells in Arteriovenous Fistulae: Bone Marrow, Artery, or the Vein Itself?
Authors: Skartsis Nikolaos , Manning Eddie , Wei Yuntao , Velazquez Omaida C. , Liu Zhao‐Jun , Goldschmidt‐Clermont Pascal J. , Salman Loay H. , Asif Arif , Vazquez‐Padron Roberto I.
Published: April 2011

To elucidate the source of neointimal cells, experimental fistulas were created in Lewis wild‐type (WT) and transgenic rats that constitutively expressed the green fluorescent protein (GFP) in all tissues. Arteriovenous fistula (AVFs) were created by anastomosing the left renal vein to the abdominal aorta. The contribution of bone marrow (BM)‐derived cells to the AVF neointima was examined in lethally irradiated WT rats that had been rescued with GFP BM cells. Neointimal cells in these chimeric rats were mostly GFP negative indicating the non‐BM origin of those cells. Then, the contribution of arterial cells to the AVF neointima was assessed in a fistula made with a GFP aorta that had been implanted orthotopically into a WT rat. Most of the neointimal cells were also GFP negative demonstrating that AVF neointimal cells are not derived from the feeding artery. Finally to study local resident cells contribution to the formation of neointimal lesions, a composite fistula was created by interposing a GFP vein between the renal vein and the aorta in a WT recipient rat. GFP neointimal cells were only found in the transplanted vein. This study suggests that neointimal cells originate from the local resident cells in the venous limb of the fistula.
Prospective Study of the Frequency of Hepatic Hemangiomas in Infants with Multiple Cutaneous Infantile Hemangiomas
Authors: Horii Kimberly A. , Drolet Beth A. , Frieden Ilona J. , Baselga Eulalia , Chamlin Sarah L. , Haggstrom Anita N. , Holland Kristen E. , Mancini Anthony J. , McCuaig Catherine C. , Metry Denise W. , Morel Kimberly D. , Newell Brandon D. , Nopper Amy J. , Powell Julie , Garzon Maria C. ,   for the Hemangioma Investigator Group
Published: April 2011

Abstract:  Multiple cutaneous infantile hemangiomas have been associated with hepatic hemangiomas. Screening of infants with five or more cutaneous infantile hemangiomas with abdominal ultrasound is often recommended. The aim of this study was to determine the frequency with which hepatic hemangiomas occur in infants with five or more cutaneous infantile hemangiomas compared to those with one to four cutaneous infantile hemangiomas and to characterize the clinical features of these hepatic hemangiomas. A multicenter prospective study of children with cutaneous infantile hemangiomas was conducted at pediatric dermatology clinics at Hemangioma Investigator Groups sites in the United States, Canada, and Spain between October 2005 and December 2008. Data were collected, and abdominal ultrasonography was performed on infants younger than 6 months old with five or more cutaneous infantile hemangiomas and those with one to four cutaneous infantile hemangiomas. Twenty‐four (16%) of the 151 infants with five or more cutaneous infantile hemangiomas had hepatic hemangiomas identified on abdominal ultrasound, versus none of the infants with fewer than five (p = 0.003). Two of the 24 infants with hepatic hemangiomas received treatment specifically for their hepatic hemangiomas. Infants with five or more cutaneous infantile hemangiomas have a statistically significantly greater frequency of hepatic hemangiomas than those with fewer than 5. These findings support the recommendation of five or more cutaneous infantile hemangiomas as a threshold for screening infants younger than 6 months old for hepatic hemangiomas but also demonstrate that the large majority of these infants with hepatic hemangiomas do not require treatment.
Diffuse Infantile Hepatic Hemangiomas: A Report of Four Cases Successfully Managed with Medical Therapy
Authors: Yeh Iwei , Bruckner Anna L. , Sanchez Rosa , Jeng Michael R. , Newell Brandon D. , Frieden Ilona J.
Published: April 2011

Abstract:  We report four cases of diffuse infantile hepatic hemangioma, a rare but potentially life‐threatening subset of hepatic hemangiomas. All patients demonstrated distinctive dome‐shaped red–purple cutaneous hemangiomas. Two patients responded to steroids and propranolol (one in combination with vincristine), and two responded to steroids and vincristine. After a systematic literature review, we identified 26 previously reported cases of diffuse infantile hepatic hemangioma. Diffuse infantile hepatic hemangioma had a mortality rate of 17% and a >70% incidence of hypothyroidism, often severe (n = 30). More than one‐third of patients developed heart failure (high output in half the cases). Based on our experience, early aggressive medical management, as well as thyroid replacement when indicated, should be initiated early in the course of diffuse infantile hepatic hemangioma pending evaluation for liver transplant.
Computational Fluid Dynamics‐Based Hydraulic and Hemolytic Analyses of a Novel Left Ventricular Assist Blood Pump
Authors: Yang Xiao‐Chen , Zhang Yan , Gui Xing‐Min , Hu Sheng‐Shou
Published: April 2011

The advent of various technologies has allowed mechanical blood pumps to become more reliable and versatile in recent decades. In our study group, a novel structure of axial flow blood pump was developed for assisting the left ventricle. The design point of the left ventricular assist blood pump 25 (LAP‐25) was chosen at 4 Lpm with 100 mm Hg according to our clinical practice. Computational fluid dynamics was used to design and analyze the performance of the LAP‐25. In order to obtain a required hydraulic performance and a satisfactory hemolytic property in the LAP‐25 of a smaller size, a novel structure was developed including an integrated shroud impeller, a streamlined impeller hub, and main impeller blades with splitter blades; furthermore, tandem cascades were introduced in designing the diffuser. The results of numerical simulation show the LAP‐25 can generate flow rates of 3–5 Lpm at rotational speeds of 8500–10 500 rpm, producing pressure rises of 27.5–148.3 mm Hg with hydraulic efficiency points ranging from 13.4 to 27.5%. Moreover, the fluid field and the hemolytic property of the LAP‐25 were estimated, and the mean hemolysis index of the pump was 0.0895% with Heuser's estimated model. In conclusion, the design of the LAP‐25 shows an acceptable result.
Roads Impact the Distribution of Noxious Weeds More Than Restoration Treatments in a Lodgepole Pine Forest in Montana, U.S.A.
Authors: Birdsall Jennifer L. , McCaughey Ward , Runyon Justin B.
Published: April 2011

A century of fire suppression has created unnaturally dense stands in many western North American forests, and silviculture treatments are being increasingly used to reduce fuels to mitigate wildfire hazards and manage insect infestations. Thinning prescriptions have the potential to restore forests to a more historically sustainable state, but land managers need to be aware of the potential impacts of such treatments on invasion by exotic plants. However, the effects of these activities on the introduction and spread of invasive plants are not well understood. We evaluated noxious weed occurrence over a 9‐year period (2001–2009) following thinning and burning treatments in a lodgepole pine forest in central Montana. Surveys were made in the treatment units and along roads for two shelterwood‐with‐reserve prescriptions, each with and without prescribed burning, burned only, and untreated controls. Five species listed as noxious weeds in Montana were recorded: spotted knapweed (Centaurea stoebe), oxeye daisy (Leucanthemum vulgare), Canada thistle (Cirsium arvense), common tansy (Tanacetum vulgare), and houndstongue (Cynoglossum officinale). With the exception of Canada thistle, noxious weeds were confined to roadsides and did not colonize silvicultural treatment areas. Roadside habitats contributed more to the distribution of noxious plant species than did silvicultural treatments in this relatively uninvaded forest, indicating the importance of weed control tactics along roads and underscoring the need to mitigate exotic plant dispersal by motorized vehicles. In addition, these findings suggest that roadways should be considered when evaluating the potential for invasion and spread of exotic plants following forest restoration treatments.
Movement of Weed Seeds in Reclamation Areas
Authors: Johnston Danielle B.
Published: April 2011

The presence or absence of obstructions can affect seed dispersal. Reclamation activities often cause changes in the type and amount of such obstructions. The consequences of removing obstructions on the dispersal of undesirable species are unknown. In western North America, reclamation may often proceed in areas surrounded by the invasive Bromus tectorum L. (cheatgrass). The importance of preventing cheatgrass seed dispersal from surrounding landscapes is an unknown factor in reducing cheatgrass competition in these areas. I quantified cheatgrass seed dispersal in the early stages of reclamation, when soils were bare. Four groups of 100 sterilized, fluorescently marked cheatgrass seeds were released in each of three areas in NW Colorado, USA. Seeds were located at night using blacklights four times over 14 days, and the distance between each seed and the point of release was measured. Across sites, dispersal distance averaged 2.4 m, 5% of seeds traveled further than 7.6 m, and maximum recorded distance was 20.8 m. Maximum distances reported in this study are 50‐fold higher than previously reported for intact sagebrush ecosystems. I suggest that the difference is due to a lack of impediments to secondary dispersal on bare soil. When reclamation areas are surrounded by weeds such as cheatgrass, seeds dispersing from the perimeter may influence restoration outcome.
Investigating the Vegetation–Soil Relationships on the Copper–Cobalt Rock Outcrops of Katanga (D. R. Congo), an Essential Step in a Biodiversity Conservation Plan
Authors: Saad Layla , Parmentier Ingrid , Colinet Gilles , Malaisse François , Faucon Michel‐Pierre , Meerts Pierre , Mahy Grégory
Published: April 2011

Plant communities of soils naturally enriched in copper and cobalt in Katanga (D. R. Congo) are critically threatened in the short term due to mining activities. For biodiversity conservation and ecosystem restoration purposes, there is an urgent need to acquire more knowledge on those plant communities including their diversity and their relationships to environmental factors. The classification of 62 vegetation plots located in 6 metal‐rich rocky hills in the Tenke Fungurume mining area resulted in 3 well‐defined steppic and steppic savanna communities. Canonical analysis showed that the community comprising the largest proportion of strictly endemic metallophytes (i.e. species that only occur on metal‐rich soils) developed in the soils with the most elevated concentrations of Cu and Co. However, contrasting species assemblages in the two other plant communities were explained by soil nutrients and percentage rocks in addition to heavy metal concentrations. The results of this study will assist with restoration efforts because they (1) provide a rigorous assessment of communities before a disturbance and (2) define essential edaphic conditions needed for the reestablishment of critical communities.
Prevalence and Burden of Chronic Migraine in Adolescents: Results of the Chronic Daily Headache in Adolescents Study (C‐dAS)
Authors: Lipton Richard B. , Manack Aubrey , Ricci Judith A. , Chee Elsbeth , Turkel Catherine C. , Winner Paul
Published: April 2011

(Headache 2011;51:693‐706)

Objective.— To estimate the prevalence of chronic migraine (CM) among adolescents and to describe the epidemiologic profile, headache characteristics, disability, and healthcare utilization of adolescents with CM in the USA.

Background.— Chronic daily headache (CDH) and CM occur in children and adolescents, but are poorly understood in these populations because their presentation is different from that in adults. It may be difficult to assign a definitive diagnosis to young people suffering from CDH because symptoms may fail to meet the criteria for one of the CDH subtypes.

Methods.— A large sample of households with at least one resident aged 12 to 19 years was selected in balance with the US Census. Data were collected in 3 phases: (1) mailed questionnaire; (2) telephone interview; and (3) 30‐day interactive voice response system diary. CM prevalence was estimated by adapting the second edition of the International Classification of Headache Disorders criteria for CM to include pediatric migraine diagnostic criteria. The population was stratified for medication overuse. Medication overuse was defined as 15 or more days per month of acute medication use. Included in the study were measures of headache characteristics, headache impact (Headache Impact Test), disability (Pediatric Migraine Disability Assessment), and healthcare and medication use. Data are reported on subjects 12 to 17 years of age only.

Results.— The US adolescent (12‐17 years) prevalence rate for CM was 0.79% (0.00‐1.70) excluding those with medication overuse and 1.75% (0.62‐2.89) when adolescents with medication overuse were included. The majority of adolescents with CM had Headache Impact Test scores greater than or equal to 60, indicating severe headache impact, and mean Pediatric Migraine Disability Assessment scores greater than 17, indicating severe headache and disability. The majority of adolescents with CM (approximately 60%) had not visited a healthcare provider in the previous year and less than one in 5 reported taking medications to prevent headaches during the last month.

Conclusions.— Results suggest that CM occurs less frequently in adolescents than adults, but like adults, adolescents are severely burdened by the disorder. Data support an unmet medical need; however, the development of optimal criteria for diagnosing adolescents with CM is critical to fully understanding how medical needs can be met within this complex population.
One Hundred Years of Migraine Research: Major Clinical and Scientific Observations From 1910 to 2010
Authors: Tfelt‐Hansen Peer C. , Koehler Peter J.
Published: April 2011

(Headache 2011;51:752‐778)

Pain research, and headache research in particular, during the 20th century, has generated an enormous volume of literature promulgating theories, questions, and temporary answers. This narrative review describes the most important events in the history of migraine research between 1910 and 2010. Based on the standard textbooks of headache: Wolff's Headache (1948 and 1963) and The Headaches (1993, 2000, and 2006) topics were selected for a historical review. Most notably these included: isolation and clinical introduction of ergotamine (1918); further establishment of vasodilation in migraine and the constrictive action of ergotamine (1938); identification of pain‐sensitive structures in the head (1941); Lashley's description of spreading scotoma (1941); cortical spreading depression (CSD) of Leão (1944); serotonin and the introduction of methysergide (1959); spreading oligemia in migraine with aura (1981); oligemia in the wake of CSD in rats (1982); neurogenic inflammation theory of migraine (1987); a new headache classification (1988); the discovery of sumatriptan (1988); migraine and calcitonin gene‐related peptide (1990); the brainstem “migraine generator” and PET studies (1995); migraine as a channelopathy, including research from the genetic perspective (1996); and finally, meningeal sensitization, central sensitization, and allodynia (1996). Pathophysiological ideas have evolved within a limited number of paradigms, notably the vascular, neurogenic, neurotransmitter, and genetic/molecular biological paradigm. The application of various new technologies played an important role within these paradigms, in particular neurosurgical techniques, EEG, methods to measure cerebral blood flow, PET imaging, clinical epidemiological, genetic, and molecular biological methods, the latter putting migraine (at least hemiplegic migraine) within a completely new classification of diseases.