bluuebunny/crossref_metadata_2025 huggingface dataset:
Changes in plasma fatty acid composition after intake of a standardised breakfast in prepubertal obese children
Authors: Gil-Campos M. , Larqué E. , Ramírez-Tortosa M. C. , Linde J. , Villada I. , Cañete R. , Gil A.
Published: October 2007

Obese patients typically show a pattern of dyslipidaemia and changes in plasma fatty acid composition reflecting abnormalities in lipoprotein metabolism and dietary habits. Animals and obese adults have been widely studied; however, contradictory results have been published in children. The objective was to assess changes in plasma fatty acid composition in total plasma lipids and plasma lipid fractions in obese prepubertal children compared with those of normal weight and to evaluate changes in postprandial plasma fatty acids during a 3 h period after intake of a standardised breakfast. The study was a case–control study with thirty-four obese and twenty normal-weight prepubertal children (Tanner 1). Anthropometric and metabolic variables and fatty acid concentrations were measured in plasma and its fractions. Liquid chromatography was used to separate lipid fractions and GLC to quantify fatty acids. Plasma total fatty acids (TFA), SFA, MUFA and PUFA concentrations were higher in obese than in control children. Except for 18 : 0, 18 : 3n-3, 20 : 4n-6 andn-3 PUFA, all fatty acids in TAG were also elevated in the obese group. Fatty acids 16 : 1n-7, 18 : 0, 18 : 1n-9, 20 : 2n-6, TFA and MUFA significantly decreased between the 2nd and 3rd hour in normal-weight v. obese children. The concentration of 16 : 1n-7 was positively and the proportion of 20 : 4n-6 inversely associated with a significant increase in risk of obesity. Obese prepubertal children show an altered plasma fatty acid profile and concentrations, mainly related to the TAG fatty acid profile, with a lower clearance of fatty acids v. normal-weight prepubertal children.
Lie methods for color robot vision
Authors: Lenz Reiner
Published: October 2007

We describe how Lie-theoretical methods can be used to analyze color related problems in machine vision. The basic observation is that the nonnegative nature of spectral color signals restricts these functions to be members of a limited, conical section of the larger Hilbert space of square-integrable functions. From this observation, we conclude that the space of color signals can be equipped with a coordinate system consisting of a half-axis and a unit ball with the Lorentz groups as natural transformation group. We introduce the theory of the Lorentz group SU(1, 1) as a natural tool for analyzing color image processing problems and derive some descriptions and algorithms that are useful in the investigation of dynamical color changes. We illustrate the usage of these results by describing how to compress, interpolate, extrapolate, and compensate image sequences generated by dynamical color changes.
Perfectionism in People who Stutter: Preliminary Findings Using a Modified Cognitive-Behavioral Treatment Approach
Authors: Amster Barbara J. , Klein Evelyn R.
Published: October 2007

Perfectionistic people set unrealistic goals and, when they fail to reach them, experience self-criticism and blame. Preliminary research revealed that perfectionism appears to be a characteristic of people who stutter (PWS) (Amster, 1995). The purpose of the present study was to explore perfectionism in PWS and to determine if a modified cognitive behavioral therapy approach alone and combined with Stuttering Modification could help reduce perfectionistic tendencies and stuttering behaviors. Degree of perfectionism and scores of stuttering severity were measured with eight adult PWS and compared at pre-treatment, mid-treatment, after 6-weeks of treatment, and at 15 weeks follow-up, after treatment was withdrawn. Initial open-trial testing showed promising results as perfectionism and stuttering severity were reduced and communication attitudes improved. CBT significantly reduced perfectionism by mid-point. Stuttering decreased significantly throughout all phases of the study. Possible implications are discussed.
Are Depressed Adolescents Routinely Offered CBT? A Brief Review of Current Practice
Authors: Ross Gill , Brannigan Chris
Published: October 2007

An increasing body of research in support of cognitive-behavioural therapy (CBT) for adolescent depression has emerged during the last two decades. However, it has been suggested that empirically supported treatments are seldom carried out in clinical practice. Although the reasons for this are likely to be diverse, it is argued that mental health services have an ethical responsibility to offer evidence-based interventions. Whether empirically supported interventions, such as CBT, are consistently offered to depressed adolescents attending Child and Adolescent Mental Health Services (CAMHS) is currently unknown. A primary aim of this study was to survey the use of CBT for depression in a number of United Kingdom (UK) CAMHS settings. A postal questionnaire was sent to 117 members of the BABCP Children, Adolescents and Families Special Interest Branch, of which 44 completed questionnaires were returned. Descriptive statistics indicate that just over half of the organizations represented routinely offered CBT to depressed adolescents. CBT practice and the transportation of evidence-based research findings to CAMHS settings are discussed.
A cost analysis of alternative culling strategies for the eradication of classical swine fever in wildlife
Authors: BOLZONI LUCA , DE LEO GIULIO A.
Published: October 2007

In the epidemiological literature, the eradication of a wildlife disease through culling is usually described in terms of a constant hunting rate to simulate the selective removal of animals from the population. By using simple SI (susceptible–infected) models, it is easy to prove that, if the hunting rate is high enough, the population eventually drops below a critical threshold level under which the pathogen is deemed to be extinct. However, hunting costs as well as the monetary benefits of disease control are almost systematically neglected. Moreover, the hunting rate is usually assumed to be constant over time, while in reality health authorities can implement more flexible culling policies. In this work we examine a class of more realistic time-variant culling strategies in a cost–benefit framework. Culling strategies differ in the way decisions are made about when and how much to cull; that is, whether hunting occurs when disease prevalence, host population density, or the number of carcasses exceeds (or is below) a given threshold. For each culling strategy, the optimal value of the control parameters and the hunting rate are those that minimize the sum of the culling costs and the sanitary costs associated with infection over a specific period of time. Classical swine fever (CSF) in wild boar populations has been taken as a reference example because of its potential economic impact on industrialized and developing countries.

We show that the optimal time-flexible culling strategy is invariably more efficient than the best traditional strategy in which the hunting rate is held constant through time. We also show that the type of hunting strategy that is selected as optimal depends on the shape of the cost functions.
NONLINEARITY IN THE CANADIAN AND U.S. LABOR MARKETS: UNIVARIATE AND MULTIVARIATE EVIDENCE FROM A BATTERY OF TESTS
Authors: PANAGIOTIDIS THEODORE , PELLONI GIANLUIGI
Published: October 2007

The nonlinearity of macroeconomic processes is becoming an increasingly important issue at both the theoretical and empirical levels. This trend holds for labor market variables as well. The reallocation theory of unemployment relies on nonlinearities. At the same time there is mounting empirical evidence of business cycles asymmetries. Thus the assumption of linearity/nonlinearity becomes crucial for the corroboration of labor market theories. This paper turns the microscope on the assumption of linearity and investigates the presence of asymmetries in aggregate and disaggregate labor market variables. The assumption of linearity is tested using five statistical tests for U.S. and Canadian unemployment rates and growth rates of the employment sectoral shares of construction, finance, manufacturing, and trade. An AR(p) model was used to remove any linear structure from the series. Evidence of nonlinearity is found for the sectoral shares with all five statistical tests in the U.S. case but not at the aggregate level. The results for Canada are not clear-cut. Evidence of unspecified nonlinearity is found in the unemployment rate and in the sectoral shares. Overall, important asymmetries are found in disaggregated labor market variables in the univariate setting. The linearity hypothesis was also examined in a multivariate framework. Evidence is provided that important asymmetries exist and a linear VAR cannot capture the dynamics of employment reallocation.
INTRODUCTION
Authors: KIRMAN ALAN
Published: October 2007

This issue contributes to the discussion of the relation between individual and aggregate behavior. The basic feature of all the models presented is that they allow for direct interaction between the individuals. This, it is shown, leads to a number of interesting phenomena that are difficult to account for in standard models. The basic message is that the inclusion of heterogeneous interacting agents allows us to escape from the pitfalls associated with the reduction to a representative individual and furthermore to show that aggregates will, in general, have behavior that is different from that of the component individuals. Lastly, complex aggregate behavior is not necessarily the result of complicated individual reasoning, it can emerge from very simple rule following by individuals.
WHAT WE DON'T KNOW ABOUT THE MONETARY TRANSMISSION MECHANISM AND WHY WE DON'T KNOW IT
Authors: BEYER ANDREAS , FARMER ROGER E.A.
Published: October 2007

We study identification in a class of linear rational expectations models. For any given exactly identified model, we provide an algorithm that generates a class of equivalent models that have the same reduced form. We use our algorithm to show that a model proposed by Jess Benhabib and Roger Farmer is observationally equivalent to the standard new-Keynesian model when observed over a single policy regime. However, the two models havedifferentimplications for the design of an optimal policy rule.
NOTE ON CONVERGENCE UNDER INCOME TAX PROGRESSIVITY
Authors: PINTUS PATRICK
Published: October 2007

Building on the theoretical prediction that income tax progressivity increases the speed of convergence in neoclassical, open-economy growth models, this paper asks whether tax progressivity is a potential source of differences across regions in convergence rates. In a sample of U.S. data, over the period 1920–1990, regional convergence and tax progressivity are found to be positively correlated, which supports the theoretical results. Moreover, some data on six OECD countries also accord with such a positive relationship. Overall, the model is successful in predicting the large range of available convergence estimates when the tax rate is elastic enough with respect to the tax base.
Evidenz-basierte Pflege am Beispiel von Kälteanwendungen nach ausgewählten orthopädischen Eingriffen – eine Literaturstudie
Authors: Cina-Tschumi Barbara
Published: October 2007

Kälte wird in der postoperativen Pflege nach orthopädischen Eingriffen häufig verwendet, um den Heilungsverlauf zu unterstützen. Mit dem Ziel, evidenzbasierte Empfehlungen zur Anwendung von Coldpacks (ColdHot Gelpack/Silikatbeutel) zu geben, wurde eine umfassende Literaturrecherche durchgeführt. In den Datenbanken Medline, Cinahl und Cochrane Library wurde nach Meta-Analysen oder klinischen, kontrollierten Untersuchungen von Kälteanwendungen nach Eingriffen an Knie, Hüfte, Schulter und Wirbelsäule gesucht. Der Fokus lag dabei auf der schmerzlindernden, abschwellenden und blutstillenden Wirkung sowie der Toleranz der Patienten. Die beschriebenen Erkenntnisse der 17 eingeschlossenen Artikel waren von unterschiedlicher Qualität und widersprachen sich zum Teil. Generell konnte einzig eine analgetische Wirkung bei kontinuierlicher Kühlung nachgewiesen werden. Kälte über 4°C wird im Allgemeinen als angenehm empfunden. Abschwellende oder blutstillende Effekte konnten nicht nachgewiesen werden. Brucheis, Silikatbeutel oder elektrisch betriebenen Kältepumpen als Kältequellen unterscheiden sich in der Handhabung, Wirkung und Wirtschaftlichkeit. Exakte Empfehlungen bezügliche Applikationsdauer und Temperatur können nicht ausgesprochen werden. Kompression und Verbandart wirken sich ebenfalls unterschiedlich auf den Kälteeffekt aus und müssen bei der Anwendung berücksichtigt werden.
A Confirmatory Factor Analytic Study of Anxiety, Fear, and Behavioral Inhibition System Measures
Authors: Cooper Andrew J. , Perkins Adam M. , Corr Philip J.
Published: October 2007

Abstract. Recent revisions to the reinforcement sensitivity theory (RST) of personality have highlighted the distinction between the emotions of fear and anxiety. These revisions have substantial implications for self-report measurement; in particular, they raise the question of whether separate traits of fear and anxiety exist and, if so, their interrelationship. To address this question, the current study used confirmatory factor analytic procedures to examine the convergent and discriminant validity of measures of trait anxiety, fear, and the behavioral inhibition system (BIS). We also examined measurement and structural invariance across gender in 167 males and 173 females who completed the Spielberger State-Trait Anxiety Inventory (STAI), the Carver and White BIS Scale, and the Fear Survey Schedule (FSS). The findings suggested that trait anxiety and the BIS scale are relatively distinct from Tissue Damage Fear (FSS). Further, the final model showed measurement and structural invariance across gender. The implications of the results for future self-report assessment in RST research are discussed.
Psychometric Properties of the Behavioral Inhibition Scale in Young Adults
Authors: Muris Peter , Rassin Eric , Franken Ingmar , Leemreis Willem
Published: October 2007

Abstract. The Behavioral Inhibition Scale (BIS) is a brief questionnaire for measuring Kagan's (1994) temperamental characteristic of children and adolescents to be unusually shy and to react with fear and withdrawal in situations that are novel and/or unfamiliar. The present study examined the psychometric properties of the BIS in two separate samples of undergraduate students (Ns = 124 and 73). The students of Sample 1 completed the BIS as well as questionnaires for measuring personality traits, anxiety, and other psychopathological symptoms, whereas students of Sample 2 completed the scale as well as a widely used anxiety inventory on two separate occasions, some 4 weeks apart. The results showed that the BIS was reliable in terms of internal consistency and test-retest stability. Further, the scale was predominantly correlated with general levels of anxiety symptoms and not with other psychopathological symptoms. Finally, the BIS was related to other personality factors in a theoretically meaningful way, and essentially seems to reflect a combination of high neuroticism/behavioral inhibition and low extraversion/behavioral approach.
Bayesian uncertainty analysis in distributed hydrologic modeling: A case study in the Thur River basin (Switzerland)
Authors: Yang Jing , Reichert Peter , Abbaspour Karim C.
Published: October 2007

Calibration and uncertainty analysis in hydrologic modeling are affected by measurement errors in input and response and errors in model structure. Recently, extending similar approaches in discrete time, a continuous time autoregressive error model was proposed for statistical inference and uncertainty analysis in hydrologic modeling. The major advantages over discrete time formulation are the use of a continuous time error model for describing continuous processes, the possibility of accounting for seasonal variations of parameters in the error model, the easier treatment of missing data or omitted outliers, and the opportunity for continuous time predictions. The model was developed for the Chaohe Basin in China and had some features specific for this semiarid climatic region (in particular, the seasonal variation of parameters in the error model in response to seasonal variation in precipitation). This paper tests and extends this approach with an application to the Thur River basin in Switzerland, which is subject to completely different climatic conditions. This application corroborates the general applicability of the approach but also demonstrates the necessity of accounting for the heavy tails in the distributions of residuals and innovations. This is done by replacing the normal distribution of the innovations by a Studenttdistribution, the degrees of freedom of which are adapted to best represent the shape of the empirical distribution of the innovations. We conclude that with this extension, the continuous time autoregressive error model is applicable and flexible for hydrologic modeling under different climatic conditions. The major remaining conceptual disadvantage is that this class of approaches does not lead to a separate identification of model input and model structural errors. The major practical disadvantage is the high computational demand characteristic for all Markov chain Monte Carlo techniques.
Goulburn River experimental catchment data set
Authors: Rüdiger Christoph , Hancock Greg , Hemakumara Herbert M. , Jacobs Barry , Kalma Jetse D. , Martinez Cristina , Thyer Mark , Walker Jeffrey P. , Wells Tony , Willgoose Garry R.
Published: October 2007

This paper describes the data set from the 6540‐km2 Goulburn River experimental catchment in New South Wales, Australia. Data have been archived from this experimental catchment since its inception in September 2002. Land use in the northern half of the catchment is predominantly cropping and grazing on basalt‐derived soils, with the south being cattle and sheep grazing on sandstone‐derived soils; only the floodplains are cleared of trees in the south. Monitoring sites are mainly concentrated in the nested Merriwa (651 km2) and Krui (562 km2) subcatchments in the northern half of this experimental catchment with a few monitoring sites located in the south. The data set comprises soil temperature and moisture profile measurements from 26 locations; meteorological data from two automated weather stations (data from a further three stations are available from other sources) including precipitation, atmospheric pressure, air temperature and relative humidity, wind speed and direction, soil heat flux, and up‐ and down‐welling short‐ and long‐wave radiation; streamflow observations at five nested locations (data from a further three locations are available from other sources); a total of three surface soil moisture maps across a 40 km × 50 km region in the north from ∼200 measurement locations during intensive field campaigns; and a high‐resolution digital elevation model (DEM) of a 175‐ha microcatchment in the Krui catchment. These data are available on the World Wide Web at http://www.sasmas.unimelb.edu.au.
Circulation and thermodynamics in a subglacial geothermal lake under the Western Skaftá cauldron of the Vatnajökull ice cap, Iceland
Authors: Jóhannesson Tómas , Thorsteinsson Thorsteinn , Stefánsson Andri , Gaidos Eric J. , Einarsson Bergur
Published: October 2007

The subglacial, geothermal lake beneath the Western Skaftá cauldron (depression) in the Vatnajökull ice cap, Iceland, was accessed by hot water drilling through the overlying 300 m‐thick ice shelf. Most of the ca. 100‐m water column was near 4.7°C, but was underlain by a distinct ∼10 m‐deep water mass at 3.5°C. The sensible heat content of the lake water is approximately twice the potential energy dissipated in outburst floods, and the temperature of the lake may be an important factor in the development of subglacial water courses of jökulhlaups from the lake. The lake temperature is higher than the temperature of maximum density, implying that convective heat transfer can take place in the lake. The vertical temperature structure suggests a large‐scale recirculating flow in the lake, the rate of which was estimated from the lake temperatures and the chemical composition of a water sample.
Far‐reaching transient motions after Mojave earthquakes require broad mantle flow beneath a strong crust
Authors: Freed Andrew M. , Bürgmann Roland , Herring Thomas
Published: October 2007

Geodetically observed postseismic surface displacements in the 7 years following the 1999 Hector Mine earthquake demonstrate a previously unrecognized broad pattern of transient deformation throughout southern California and into Nevada, more than 200 km from the epicenter. Unlike previous postseismic observations in which trade‐offs between postseismic mechanisms and the depth of flow lead to non‐unique solutions, this deformation pattern can only be explained by viscoelastic flow in a region of the mantle 100s of km wide and below a depth of 40 km. This result enables two robust conclusions regarding the nature of lithospheric strength in this region: the mantle is weaker than the lower crust, and flow occurs over a wide region of mantle as opposed to within a narrow shear zone beneath the fault.
Long‐term probabilistic forecast of climate impact on air quality: Model development andt* distribution
Authors: Chu Shao‐Hang
Published: October 2007

Models are great tools to test ideas. Their usefulness, however, depends on their ability to simulate the current reality and to predict the future. In this study, I have derived a newt* distribution. I show that a statistical model based on thet* distribution of station temporal data is capable of predicting the probability of any future outcome to exceed a specific value using only the currently available sample statistics assuming a normal random variable. In an air quality management application the model has demonstrated categorically an average success rate of over 80% both in simulating the current ozone nonattainment areas and in forecasting the rate of future violation of the 8‐hour ozone National Ambient Air Quality Standards in the United States for up to 12 years. While the predictability of deterministic climate models is still limited by large uncertainties, the probabilistic forecast by this model provides a promising alternative in assessing the climate impact on environment for decades.
The anticancer drug cisplatin induces an intrinsic apoptotic pathway inside the inner ear
Authors: García‐Berrocal J R , Nevado J , Ramírez‐Camacho R , Sanz R , González‐García J A , Sánchez‐Rodríguez C , Cantos B , España P , Verdaguer J M , Trinidad Cabezas A
Published: October 2007

Background and purpose:

Ototoxicity is a known adverse effect of cisplatin (CDDP). Since apoptosis is involved in the development of some pathological conditions associated with the administration of anticancer drugs, we examined, using immunohistochemical and electrophysiological techniques, the apoptotic changes in the cochlea of Sprague‐Dawley (SD) rats after an injection of CDDP (5 mgkg‐1 body weight).

Experimental approach:

Luciferase assays were used to determine the different caspase activities and ATP levels in protein extracts of whole cochleae. The expression of several apoptotic‐related proteins was measured by means of Western blotting. These analyses were performed 2, 7 and 30 days after the CDDP injection. The auditory brain stem response was obtained before and at the different times after the injection of CDDP, before the animals were killed.

Key results:

CDDP significantly increased the levels of caspase‐3/7 activity and active caspase‐3 protein expression and caspase‐3 immunofluorescence staining, caspase‐9 activity, and Bax protein expression but decreased Bcl‐2 protein expression within the rat cochleae. Threshold shifts were significantly elevated 2 days after CDDP treatment.

Conclusions and implications:

These findings support the hypothesis that cisplatin‐related apoptosis evokes an intrinsic pathway of pro‐apoptotic signalling within the rat cochleae. Thus, selective inhibition of the sequence of events involved in the intrinsic apoptotic pathway could provide a strategy to minimize cisplatin‐induced ototoxicity.

British Journal of Pharmacology (2007) 152, 1012–1020; doi:10.1038/sj.bjp.0707405; published online 1 October 2007
Biology and therapeutic potential of cannabinoid CB2receptor inverse agonists
Authors: Lunn C A , Reich E‐P , Fine J S , Lavey B , Kozlowski J A , Hipkin R W , Lundell D J , Bober L
Published: October 2007

Evidence has emerged suggesting a role for the cannabinoid CB2receptor in immune cell motility. This provides a rationale for a novel and generalized immunoregulatory role for cannabinoid CB2receptor‐specific compounds. In support of this possibility, we will review the biology of a class of cannabinoid CB2receptor—specific inverse agonist, the triaryl bis‐sulfones. We will show that one candidate, Sch.414319, is potent and selective for the cannabinoid CB2receptor, based on profiling studies using biochemical assays for 45 enzymes and 80 G‐protein coupled receptors and ion channels. We will describe initial mechanistic studies using this optimized triaryl bis‐sulfone, showing that the compound exerts a broad effect on cellular protein phosphorylations in human monocytes. This profile includes the down regulation of a required phosphorylation of the monocyte‐specific actin bundling protein L‐plastin. We suggest that this observation may provide a mechanism for the observed activity of Sch.414319in vivo. Our continued analysis of thein vivoefficacy of this compound in diverse disease models shows that Sch.414319 is a potent modulator of immune cell mobilityin vivo, can modulate bone damage in antigen‐induced mono‐articular arthritis in the rat, and is uniquely potent at blocking experimental autoimmune encephalomyelitis in the rat.

British Journal of Pharmacology(2008)153, 226–239; doi:10.1038/sj.bjp.0707480; published online 1 October 2007
Enhanced angiotensin converting enzyme 2 regulates the insulin/Akt signalling pathway by blockade of macrophage migration inhibitory factor expression
Authors: Zhong J‐C , Yu X‐Y , Lin Q‐X , Li X‐H , Huang X‐Z , Xiao D‐Z , Lin S‐G
Published: October 2007

Background and purpose:

Macrophage migration inhibitory factor (MIF) is now known to be a pro‐inflammatory cytokine associated with insulin resistance. Our aim was to investigate whether angiotensin converting enzyme 2 (ACE2) could modulate the expression of MIF and the insulin/Akt‐endothelial nitric oxide (NO) synthase (eNOS) signalling in a human endothelial cell line (EAhy926).

Experimental approach:

A recombinant plasmid encompassing human ACE2 gene was constructed and transfected into the EAhy926 cells. The mRNA, phosphorylation and protein levels of p22phox, MIF, Akt and eNOS in endothelial cells were determined by real‐time PCR and Western blot analysis, respectively.

Key results:

Gene transfer of ACE2 suppressed the expression of p22phox and MIF induced by angiotensin (Ang) II and Ang IV, accompanied by a decreased level of malondialdehyde in cells. In addition, Ang II diminished insulin‐stimulated phosphorylation of Akt (at Ser473) and eNOS (at Ser1177) and NO generation, effects which were reversed by ACE2 gene transfer and anti‐MIF treatment in endothelial cells.

Conclusions and implications:

The results reveal that gene transfer of ACE2 regulated Ang II‐mediated impairment of insulin signalling and involved the Akt‐eNOS phosphorylation pathway. These beneficial effects of ACE2 overexpression appear to result mainly from blocking MIF expression in endothelial cells, suggesting that the ACE2 gene may be a novel therapeutic target for diseases related to inflammation and insulin resistance.

British Journal of Pharmacology (2008) 153, 66–74; doi:10.1038/sj.bjp.0707482; published online 1 October 2007
Interventional Nephrology and Dialysis: The Initial Creation of Native Arteriovenous Fistulas: Surgical Aspects and Their Impact on the Practice of Nephrology
Authors: Konner Klaus
Published: October 2007

A highly welcomed, increasing number of arteriovenous fistulas (AVFs) has been noted in recent years as has a high rate of early failure. The latter is not an inevitable consequence of the former. Potential contributors may be identified by an analysis of surgical strategies and details of the creation of arteriovenous (AV) anastomoses. The “simple” AVF is all but simple. Construction of the anastomosis is a tool, not the aim of access surgery. The aim is a rapidly maturing and well‐functioning fistula, a high flow construct that can be cannulated easily and repeatedly for adequate hemodialysis (HD) therapy. Surgical details are illustrated to clarify verbal descriptions. The impact of a high quality of initial vascular access on the practice of nephrology is mentioned. Closing remarks try to define a vascular access team as the optimal option for future management of vascular access.
Interventional Nephrology and Dialysis: Continuous Flow Peritoneal Dialysis: Principles and Applications
Authors: Amerling Richard , Glezerman Ilya , Savransky Eric , Dubrow Alan , Ronco Claudio
Published: October 2007

Continuous flow peritoneal dialysis (CFPD) is a technique of renal replacement therapy (RRT) dating back to the 1960s. Its essential features are a fixed intraperitoneal volume and rapid, continuous movement of dialysis solution into and out of the peritoneal cavity. Inlet and outlet catheters and a means of generating a large volume of sterile dialysate are required. External regeneration of dialysate via conventional hemodialysis (HD) equipment or sorbent technology mitigates the need for large volumes of sterile fluid and makes the technique feasible. Clearance depends on the peritoneal mass transfer coefficient, rate of dialysate flow, and efficiency of external regeneration. Studies to date all demonstrate small solute clearances three to eight times greater than conventional automated peritoneal dialysis (PD). Catheter design is crucial to the clinical success of the technique and will be discussed. Potential applications include daily home dialysis, treatment of acute renal failure in the intensive care unit (ICU), and ultrafiltration of ascites. Clinical experience with the latter will be presented in detail.
Interventional Nephrology and Dialysis: Access Flow Measurement During Surveillance and Percutaneous Transluminal Angioplasty Intervention
Authors: Krivitski Nikolai M.
Published: October 2007

The introduction of routine access flow measurement methodology has enabled accurate identification of problematic accesses and provided a means for follow‐up evaluation. These methods have uncovered, in some cases, that interventions are either immediately unsuccessful or that they fail within 3 months to maintain flow above preintervention levels. The purpose of this article is to analyze the main problems that occur at each step in the loop of flow surveillance–intervention–follow‐up and to provide suggestions for improving outcomes. Analysis of published access flow data suggests that the main problems lie in the areas of inadequate analysis of flow surveillance data, lack of objective technology for quantifying intervention effectiveness, and lack of follow‐up flow measurements in the hemodialysis (HD) unit after the intervention. The following three recommendations may improve surveillance outcomes: 1) using a reliable access flow technology combined with analysis of all hemodynamic data (including mean arterial pressure) before referring patients for angiography to decrease surveillance false positives; 2) performing intra‐access blood flow measurement during angioplasty, which may improve outcomes by giving warning of errors before the patient leaves the intervention suite. Success achieved in restoring flow as measured during the intervention usually predicts good immediate outcomes in the HD unit; 3) measuring access flows during the next week after angioplasty. If the results are unsatisfactory, the patient should be further evaluated to avoid a potential thrombotic event.
Pore-scale simulations of drainage of heterogeneous and anisotropic porous media
Authors: Tartakovsky Alexandre M. , Ward Andy L. , Meakin Paul
Published: October 2007

A numerical model, based on smoothed particle hydrodynamics, was used to simulate pore-scale liquid and gas flow in synthetic two-dimensional porous media consisting of nonoverlapping grains. The model was used to study the effects of pore-scale heterogeneity and anisotropy on the relationship between the average saturation and the Bond number (strength of the gravitational field acting on fluid density differences relative to capillary forces). Pore-scale anisotropy was created by using co-oriented nonoverlapping elliptical grains, and heterogeneity was created by inserting a microfracture in the middle of the porous domain consisting of nonoverlapping circular grains. The effect of the wetting fluid properties on drainage was also investigated. It is shown that pore-scale heterogeneity and anisotropy can give rise to saturation/Bond number relationships and entry (bubbling) pressures that depend on the flow direction, suggesting that these properties should be described by tensor rather than scalar quantities.
ZnO field-effect transistors prepared by aqueous solution-growth ZnO crystal thin film
Authors: Li Chensha , Li Yuning , Wu Yiliang , Ong Beng S. , Loutfy Rafik O.
Published: October 2007

A ZnO thin-film transistor (TFT) with a channel layer formed via aqueous solution-growth at low temperature is demonstrated. This ZnO thin-film semiconductor has a well-controlled crystalline form, exhibiting n-channel, enhancement-mode behavior with a channel mobility as large as 0.56 cm2 V−1 s−1. Low-cost, superior transistor characteristics and low-temperature processing makes ZnO TFT attractive for flexible electronics on temperature sensitive substrates.
Oxygen K-edge fine structures of water by x-ray Raman scattering spectroscopy under pressure conditions
Authors: Fukui Hiroshi , Huotari Simo , Andrault Denis , Kawamoto Tatsuhiko
Published: October 2007

Fine structure of the oxygen K edge was investigated for water at ambient pressure, 0.16, 0.21, 0.27, 0.47, and 0.60GPa using x-ray Raman scattering spectroscopy (XRS). Similarity in near-edge structures at 0.16 and 0.60GPa suggests little difference in the electronic state of oxygen in the low-pressure and high-pressure forms of water. Yet, we observed significant variation of preedge structure of the XRS spectra with compression. The intensity of the preedge peak at 535.7eV has a minimal value at around 0.3GPa, indicating that the number of hydrogen bonding increases first and then decreases as a function of pressure.
Study of nonlinear processes of a large experimental thermoacoustic-Stirling heat engine by using computational fluid dynamics
Authors: Yu G. Y. , Luo E. C. , Dai W. , Hu J. Y.
Published: October 2007

This article focuses on using computational fluid dynamics (CFD) method to study several important nonlinear phenomenon and processes of a large experimental thermoacoustic-Stirling heat engine. First, the simulated physical model was introduced, and the suitable numerical scheme and algorithm for the time-dependent compressible thermoacoustic system was determined through extensive numerical tests. Then, the simulation results of the entire evolution process of self-excited thermoacoustic oscillation and the acoustical characteristics of pressure and velocity waves were presented and analyzed. Especially, the onset temperature and the saturation process of dynamic pressure were captured by the CFD simulation. In addition, another important nonlinear phenomenon accompanying the acoustic wave, which is the steady mass flow through the traveling-wave loop inside the thermoacoustic engine, was studied. To suppress the steady mass flow numerically, a fan model was adopted in the simulation. Finally, the multidimensional effects of vortex formation in the thermal buffer tube and other components were displayed numerically. Most importantly, a substantial comparison between the simulation and experiments was made, which demonstrated well the validity and powerfulness of the CFD simulation for characterizing several complicated nonlinear phenomenon involved in the self-excited thermoacoustic heat engine.
Film thickness dependence of electro-optic effects in epitaxial Ba0.7Sr0.3TiO3 thin films
Authors: Qiu J. H. , Jiang Q.
Published: October 2007

Based on the phenomenological Landau-Devonshire thermodynamic theory, the film thickness dependence of ferroelectric and electro-optic properties of epitaxial Ba0.7Sr0.3TiO3 thin films is investigated. Theoretical analysis shows that the films of 600 nm thick grown on (001) LaAlO3 and (001) (LaAlO3)0.3(Sr2AlTaO6)0.35 substrates have the large linear electro-optic effects, which are in good quantitative agreement with the experimental ones reported for the Ba0.7Sr0.3TiO3 thin films. Moreover, the obvious quadratic electro-optic effect is theoretically predicted for the film of 600 nm thick on (001) MgO substrate.
Thin-film evolution equation for a strained solid film on a deformable substrate: Numerical steady states
Authors: Tekalign W. T. , Spencer B. J.
Published: October 2007

We consider the nonlinear behavior of the thin-film evolution equation for a strained solid film on a substrate. The evolution equation describes morphological changes to the film by surface diffusion in response to elastic energy, surface energy, and wetting energy. Due to the thin-film approximation, the elastic response of the film is determined analytically, resulting in a self-contained evolution equation which does not require separate numerical solution of the full three-dimensional elasticity problem. Using a pseudospectral predictor-corrector method we numerically determine the family of steady state solutions to this evolution equation which correspond to quantum dot and quantum ridge morphologies.
Wideband impedance spectrum analyzer for process automation applications
Authors: Doerner Steffen , Schneider Thomas , Hauptmann Peter R.
Published: October 2007

For decades impedance spectroscopy is used in technical laboratories and research departments to investigate effects or material characteristics that affect the impedance spectrum of the sensor. Establishing this analytical approach for process automation and stand-alone applications will deliver additional and valuable information beside traditional measurement techniques such as the measurement of temperature, flow rate, and conductivity, among others. As yet, most of the current impedance analysis methods are suited for laboratory applications only since they involve stand-alone network analyzers that are slow, expensive, large, or immobile. Furthermore, those systems offer a large range of functionality that is not being used in process control and other fields of application. We developed a sensor interface based on high speed direct digital signal processing offering wideband impedance spectrum analysis with high resolution for frequency adjustment, excellent noise rejection, very high measurement rate, and convenient data exchange to common interfaces. The electronics has been implemented on two small circuit boards and it is well suited for process control applications such as monitoring phase transitions, characterization of fluidal systems, and control of biological processes. The impedance spectrum analyzer can be customized easily for different measurement applications by adapting the appropriate sensor module. It has been tested for industrial applications, e.g., dielectric spectroscopy and high temperature gas analysis.
Ferromagnetism of Co-doped TiO2(B) nanotubes
Authors: Wang X. W. , Gao X. P. , Li G. R. , Gao L. , Yan T. Y. , Zhu H. Y.
Published: October 2007

The Co-doped titanate nanotubes, synthesized via a hydrothermal reaction, are calcined at 300, 400, and 500°C for 2h in an argon atmosphere to yield Co-doped TiO2(B) nanotubes and anatase nanotubes with a dark gray color. It is shown that all calcined titania nanotubes have a stronger absorption in visible region, attributed to the formation of oxygen vacancies. The saturation magnetization of all Co-doped titania nanotubes is stronger than that of as-prepared Co-doped titanate nanotubes. In particular, Co-doped TiO2(B) nanotubes calcined at 300°C exhibit the strongest ferromagnetism due to the existence of oxygen vacancies, as confirmed further by electron paramagnetic resonance spectra.
Unexpected formation of ε iron nitride by gas nitriding of nanocrystalline α-Fe films
Authors: Wohlschlögel M. , Welzel U. , Mittemeijer E. J.
Published: October 2007

Polycrystalline iron thin films exhibiting different crystallite sizes, which were deposited on α-Al2O3 substrates by molecular beam epitaxy, were nitrided in a NH3∕H2 gas mixture. After different nitriding treatments the specimens were prepared and analyzed by focused ion beam microscopy and x-ray diffraction. It was found that formation of ε-Fe3N1+x occurs upon nitriding of specimens exhibiting a small crystallite size at values of the thermodynamic nitriding parameters for which pure γ′-Fe4N1−x is predicted to form according to bulk thermodynamics. This unexpected phenomenon is explained as a consequence of the nanocrystalline nature on the thermodynamics of the binary system iron-nitrogen.
A very low temperature single crystal germanium growth process on insulating substrate using Ni-induced lateral crystallization for three-dimensional integrated circuits
Authors: Park Jin-Hong , Kapur Pawan , Saraswat Krishna C. , Peng Hailin
Published: October 2007

Metal (Ni)-induced lateral crystallization (MILC) of amorphous (α)-germanium (Ge) films on silicon dioxide (SiO2) is investigated on α-Ge planar films, annealing at 350–380°C in a N2 ambient. MILC is not observed after annealing for 1h at 350°C, and self-nucleation with its small, deleterious microcrystals plagues the process at 380°C. 360°C is determined to be an optimum annealing temperature. These conditions are subsequently applied to a patterned nanowire to obtain a single-crystal Ge wire on SiO2. The method is promising for integrating high quality Ge transistors at low temperatures as required by three-dimensional integrated circuits.
Medium resolution off-axis electron holography with millivolt sensitivity
Authors: Cooper David , Truche Robert , Rivallin Pierrette , Hartmann Jean-Michel , Laugier Frederic , Bertin Francois , Chabli Amal , Rouviere Jean-Luc
Published: October 2007

Focused ion beam prepared silicon calibration specimens with boron doped layers have been examined using off-axis electron holography. By using a state-of-the-art FEI Titan microscope with unprecedented stability, we have been able to record holograms for time periods of 128s with contrast levels of almost 40% and an average signal on the charge coupled device camera of 30 000 counts. A consequence of this is a significant improvement of the signal-to-noise ratio in the phase images allowing steps in potential of less than 0.030±0.003V to be measured if sufficient care is taken during specimen preparation.
Intersubband absorption in AlN∕GaN∕AlGaN coupled quantum wells
Authors: Driscoll Kristina , Bhattacharyya Anirban , Moustakas Theodore D. , Paiella Roberto , Zhou Lin , Smith David J.
Published: October 2007

Al N ∕ Ga N ∕ Al Ga N coupled quantum wells grown by molecular beam epitaxy have been developed and characterized via intersubband absorption spectroscopy. In these structures, an AlGaN layer of sufficiently low Al content is used to achieve strong interwell coupling without the need for ultrathin inner barriers. At the same time, AlN is used in the outer barriers to provide the large quantum confinement required for near-infrared intersubband transitions. The composition of the inner barriers also provides a continuously tunable parameter to control the coupling strength. Double intersubband absorption peaks are measured in each sample, at photon energies in good agreement with theoretical expectations.
Fullerene nanostructure-induced excellent mechanical properties in hydrogenated amorphous carbon
Authors: Wang Qi , Wang Chengbing , Wang Zhou , Zhang Junyan , He Deyan
Published: October 2007

Hydrogenated amorphous carbon films were deposited by dc-pulse plasma chemical vapor deposition. The structure of as-prepared films, characterized by transmission electron microscopy, Raman spectra, and x-ray photoelectron spectra, is considered as nanocomposite thin films with C60 and fullerene crystalline nanoparticles embedded in amorphous sp2 and sp3 carbon matrices. The high hardness and high elastic recovery of as-prepared films are attributed to the unique structure that C60 and fullerene nanocrystalline grains (soft) dispersed in amorphous carbon phase (hard) to form a network structure, which restrains the dislocation migration, assists the stress relaxation, and hence, enhances the mechanical properties of the films.
Symmetric and asymmetric domain wall diodes in magnetic nanowires
Authors: Bryan M. T. , Schrefl T. , Allwood D. A.
Published: October 2007

Micromagnetic simulations reveal how transverse domain walls couple with triangular diodes in magnetic nanowires. For symmetric diodes, the coupling explains the observed differences in the magnetic field required to depin domain walls traveling in opposite directions. In asymmetric diodes, the wall-triangle interaction can lead to order-of-magnitude differences in the depinning fields of oppositely magnetized walls traveling in the same direction. The asymmetric structures therefore combine the diode function of the symmetric structures with domain wall chirality filtering. We also show how two back-to-back diodes may be used to trap a domain wall and form a memory element.
Magnetic field tuning of hot electron resonant capture in a semiconductor device
Authors: Spasov S. , Allison G. , Patanè A. , Ignatov A. , Eaves L. , Maude D. K. , Hopkinson M. , Airey R.
Published: October 2007

We study hot-electron capture on resonant N-impurities in the dilute nitride Ga(AsN) alloy under high magnetic fields up to 23T. We show that when the ratio of electric and magnetic fields reaches a critical value, the trajectory of conduction electrons becomes fully localized in real space; this leads to a negative differential conductance and current instabilities tuneable by magnetic field.
High temperature operation of λ≈3.3μm quantum cascade lasers
Authors: Devenson J. , Cathabard O. , Teissier R. , Baranov A. N.
Published: October 2007

We report quantum cascade lasers emitting at a wavelength near 3.3μm up to a temperature of 400K in pulsed mode. A fine tuning of the InAs∕AlSb active region design allowed to maintain efficient electron injection and to reduce thermal backfilling at high temperatures. The threshold current density is 3kA∕cm2 at 300K with characteristic temperature T0 of 175K. The lasers emitted up to 1W peak power in a single lateral mode at room temperature.
Design and formation mechanism of self-organized core/shell structure composite powder in immiscible liquid system
Authors: Wang Cui Ping , Liu Xing Jun , Shi Rong Pei , Shen Chen , Wang Yunzhi , Ohnuma Ikuo , Kainuma Ryosuke , Ishida Kiyohito
Published: October 2007

Under the guidance of the calculation of phase diagrams method, the self-organized Cu alloy/stainless steel composite powders with a core/shell microstructure were developed based on the gas atomization process, and the formation evolution of self-organized core/shell structure composite powders was modeled by the phase field method. This paper gives a more detailed explanation for the formation of self-organized core/shell structure composite powders from the viewpoints of thermodynamics and kinetics. Such core/shell structure composite powders have good combination of high strength and corrosion resistance (Fe-rich phase) and high electric and thermal conductivities (Cu-rich phase) with many potential advanced applications in electronic devices.