bluuebunny/crossref_metadata_2025 huggingface dataset:
InAs nanostructures on InGaAsP/InP(001): Interaction of InAs quantum-dash formation with InGaAsP decomposition
Authors: Genz F. , Lenz A. , Eisele H. , Ivanova L. , Timm R. , Pohl U. W. , Dähne M. , Franke D. , Künzel H.
Published: July 2010

Cross-sectional scanning tunneling microscopy is used to study the spatial structure and composition of self-assembled InAs nanostructures grown on InGaAsP lattice matched to the InP substrate. Images of the (110) and (1¯10) cleavage surfaces reveal InAs quantum dashes of different lateral extensions. They are found to be about 60 nm long, about 15 nm wide, about 2 nm high, and to consist of pure InAs. Furthermore, the quaternary InGaAsP matrix material below, in between, and above the quantum-dash layers shows a strong lateral contrast variation, which is related to a partial decomposition into columns of more InAs-rich and more GaP-rich regions. The effect is particularly pronounced along the [110] direction. A quantitative analysis of this strain-induced contrast yields a decomposition characterized by variations of the group-III and/or group-V concentrations in the order of ±10%. The data strongly indicate that the strain at the growth surface induced by the decomposition of the underlying matrix material plays an important role for the nucleation and formation of the quantum dashes as well as for their unexpected stacking over interlayer distances as large as 40 nm. Despite of the observation that the quantum dashes enforce the decomposition, which was already developed directly at the InGaAsP/InP interface without any influence of the subsequently grown InAs quantum dashes.
Terrestrial Gross Carbon Dioxide Uptake: Global Distribution and Covariation with Climate
Authors: Beer Christian , Reichstein Markus , Tomelleri Enrico , Ciais Philippe , Jung Martin , Carvalhais Nuno , Rödenbeck Christian , Arain M. Altaf , Baldocchi Dennis , Bonan Gordon B. , Bondeau Alberte , Cescatti Alessandro , Lasslop Gitta , Lindroth Anders , Lomas Mark , Luyssaert Sebastiaan , Margolis Hank , Oleson Keith W. , Roupsard Olivier , Veenendaal Elmar , Viovy Nicolas , Williams Christopher , Woodward F. Ian , Papale Dario
Published: July 2010

Carbon Cycle and Climate Change

As climate change accelerates, it is important to know the likely impact of climate change on the carbon cycle (see the Perspective by

Reich

). Gross primary production (GPP) is a measure of the amount of CO
2
removed from the atmosphere every year to fuel photosynthesis.

Beer
et al.

(p.
834
, published online 5 July) used a combination of observation and calculation to estimate that the total GPP by terrestrial plants is around 122 billion tons per year; in comparison, burning fossil fuels emits about 7 billion tons annually. Thirty-two percent of this uptake occurs in tropical forests, and precipitation controls carbon uptake in more than 40% of vegetated land. The temperature sensitivity (Q10) of ecosystem respiratory processes is a key determinant of the interaction between climate and the carbon cycle.

Mahecha
et al.

(p.
838
, published online 5 July) now show that the Q10 of ecosystem respiration is invariant with respect to mean annual temperature, independent of the analyzed ecosystem type, with a global mean value for Q10 of 1.6. This level of temperature sensitivity suggests a less-pronounced climate sensitivity of the carbon cycle than assumed by recent climate models.
Research ethics in dissertations: ethical issues and complexity of reasoning
Authors: Kjellström S , Ross S N , Fridlund B
Published: July 2010

Background

Conducting ethically sound research is a fundamental principle of scientific inquiry. Recent research has indicated that ethical concerns are insufficiently dealt with in dissertations.

Purpose

To examine which research ethical topics were addressed and how these were presented in terms of complexity of reasoning in Swedish nurses' dissertations.

Methods

Analyses of ethical content and complexity of ethical reasoning were performed on 64 Swedish nurses' PhD dissertations dated 2007.

Results

A total of seven ethical topics were identified: ethical approval (94% of the dissertations), information and informed consent (86%), confidentiality (67%), ethical aspects of methods (61%), use of ethical principles and regulations (39%), rationale for the study (20%) and fair participant selection (14%). Four of those of topics were most frequently addressed: the majority of dissertations (72%) included 3–5 issues. While many ethical concerns, by their nature, involve systematic concepts or metasystematic principles, ethical reasoning scored predominantly at lesser levels of complexity: abstract (6% of the dissertations), formal (84%) and systematic (10%).

Conclusions

Research ethics are inadequately covered in most dissertations by nurses in Sweden. Important ethical concerns are missing, and the complexity of reasoning on ethical principles, motives and implications is insufficient. This is partly due to traditions and norms that discount ethical concerns but is probably also a reflection of the ability of PhD students and supervisors to handle complexity in general. It is suggested that the importance of ethical considerations should be emphasised in graduate and post-graduate studies and that individuals with capacity to deal with systematic and metasystematic concepts are recruited to senior research positions.
Non-equivalent stringency of ethical review in the Baltic States: a sign of a systematic problem in Europe?: Figure 1
Authors: Gefenas E , Dranseika V , Cekanauskaite A , Hug K , Mezinska S , Peicius E , Silis V , Soosaar A , Strosberg M
Published: July 2010

We analyse the system of ethical review of human research in the Baltic States by introducing the principle of equivalent stringency of ethical review, that is, research projects imposing equal risks and inconveniences on research participants should be subjected to equally stringent review procedures. We examine several examples of non-equivalence or asymmetry in the system of ethical review of human research: (1) the asymmetry between rather strict regulations of clinical drug trials and relatively weaker regulations of other types of clinical biomedical research and (2) gaps in ethical review in the area of non-biomedical human research where some sensitive research projects are not reviewed by research ethics committees at all. We conclude that non-equivalent stringency of ethical review is at least partly linked to the differences in scope and binding character of various international legal instruments that have been shaping the system of ethical review in the Baltic States. Therefore, the Baltic example could also serve as an object lesson to other European countries which might be experiencing similar problems.
Ethical considerations for classifying patients as ‘palliative’ when calculating Hospital Standardised Mortality Ratios
Authors: Downar James , Sibbald Robert , Lazar Neil M
Published: July 2010

The Hospital Standardised Mortality Ratio (HSMR) is a commonly used measure of hospital mortality that is standardised for age, comorbidities and other factors. By tradition, this statistic has always excluded patients classified as ‘palliative’. The HSMR has never been validated as a reliable measure of quality of care, and it can be very hard to interpret, partly due to difficulties with defining and applying the term ‘palliative’. In this paper, we review the Canadian experience with the palliative status flag, and explain why it is so difficult to define and apply consistently. We also highlight some potential concerns about clinicians labelling inpatients as ‘palliative’ during their admission. Finally, we propose an organisational ethics framework, and six specific suggestions for hospitals to use when publishing statistics such as the HSMR.
TOPOLOGICAL 1-SOLITON SOLUTION OF THE GENERALIZED RADHAKRISHNAN, KUNDU, LAKSHMANAN EQUATION WITH NONLINEAR DISPERSION
Authors: STURDEVANT BENJAMIN , LOTT DAWN A. , BISWAS ANJAN
Published: July 2010

This paper talks about obtaining an exact 1-soliton solution of the generalized Radhakrishnan, Kundu, Lakshmanan equation with nonlinear dispersion. The solitary wave ansatz will be used to carry out the integration. It will be proved that dark optical solitons can exist only when the power law nonlinearity reduces to Kerr law.
SECONDARY CONVERGENCE IN FEMTOSECOND LASER TRAPPING
Authors: JIANG YUQIANG , MA CUNGEN , OH ISAMU , HOSOKAWA YOICHIROH , MASUHARA HIROSHI
Published: July 2010

When femtosecond laser pulses pass through a trapped polystyrene bead, water breakdown is induced even though the energy of laser pulse is much lower compared to the threshold value of breakdown when the femtosecond laser directly irradiates in water. This mechanism is assigned to the secondary convergence of the laser by the trapped bead.
ON NEW EXACT SPECIAL SOLUTIONS OF THEGNLS(m,n,p,q) EQUATIONS
Authors: INÇ MUSTAFA
Published: July 2010

In this paper, we establish exact special solutions of the generalized nonlinear Schrödinger equation with nonlinear dispersion (called the GNLS (m,n,p,q) equation) by using a sn - cn method. Some new Jacobi elliptic, envelope compacton and solitary pattern solutions of GNLS (m,n,p,q) equations are obtained.
FILTERING AND DENOISING IN LINEAR REGRESSION ANALYSIS
Authors: HASSANI HOSSEIN , MAHMOUDVAND RAHIM , YARMOHAMMADI MASOUD
Published: July 2010

In this paper we examine the effect of outlier/leverage point on the accuracy measures in the linear regression models. We use the coefficient of determination, which is a measure of model adequacy, to compare the effect of filtering approach on the least squares estimates. We also compare the performance of the filter-based approach with several resistant methods in a situation where there are several outliers in the data sets. Specifically, we examine the sensitivity of the resistant methods and the proposed approach in the circumstances where there are several leverage points in the data sets. To gain a better understanding of the effect of filtering and evaluating the performance of the proposed approach, we consider real data and simulation studies with several sample sizes, different percentage of outliers, and various noise levels.
EXPERIMENTAL EVALUATION OF THE TESTING CONDITIONS INFLUENCE ON SHOULDER PROSTHESES SUBLUXATION AND EDGE DISPLACEMENT DURING ASTM F2028-05 TESTING
Authors: CIOFFI MARGHERITA , NECCHI SILVIA , VILLA TOMASO , PENNATI GIANCARLO
Published: July 2010

Glenoid failure is one of the major indications for revision in total shoulder arthroplasty. Glenoid components should be carefully designed to improve the reliability of the prostheses, and mechanical testing can be a key tool to compare the performances of different designs. The most relevant guidelines for mechanical testing of glenoid prostheses are included in the ASTM F2028-05 Standard. The Standard refers to glenoid subluxation tests, designed to evaluate the intrinsic stability of the prosthesis system, and to glenoid edge displacement tests, which estimate the risk of micro-motions at the bone-glenoid interface. However, some indications given by the Standard are not mandatory, leaving the possibility to choose some parameters of the testing set-up and procedure. The main goal of this study was to investigate how different testing parameters (i.e. loads, velocities and bone-glenoid conformity) may affect the test results. In order to reach this target an experimental apparatus was developed and mechanical tests were performed on a keeled glenoid. The study showed that the applied load and the bone-glenoid conformity have a significant effect on the tests results, because of bone and glenoid deformation. Contrarily, the testing velocity was not found to be an influencing testing parameter.
RELATIONSHIP BETWEEN SAGITTAL SPINAL CURVES AND BACK SURFACE PROFILES OBTAINED WITH RADIOGRAPHS
Authors: BERTHONNAUD E. , FOUGIER P. , HILMI R. , LABELLE H. , DIMNET J.
Published: July 2010

The purpose of this article is to introduce a novel approach, by using coupled video and radiographic analysis of back surface and spinal curves in the sagittal plane to decrease the ionizing radiation exposure for subjects requiring long-term follow-up of their spinal deformity. This approach is specifically designed for the use in a clinical set-up for the follow-up of subjects with progressive spinal deformities. The subjects are radiographed with nine steel balls embedded in circular markers evenly distributed on the subject's back surface over the spinous processes of C7 to S1. A technique allows to draw the external back profile and the spinal curve. Patient-specific transfer functions are defined moving the back profile to the spinal curve. Sixteen adult volunteers were tested to validate the concepts proposed. For each of them, the values of transfer functions between radiographic back surface profile and corresponding spinal curve have been calculated. Each internal curve is correctly simulated when based upon the back profile. Our research is now focused on the prediction of the internal curve of patients from their back surface profile based on patient-specific transfer functions.
A density functional investigation of hydrogen peroxide activation by high-valent heme centers: implications for the catalase catalytic cycle
Authors: Silaghi-Dumitrescu Radu
Published: July 2010

Catalases employ a tyrosinate-ligated ferric heme in order to catalyze the dismutation of hydrogen peroxide to O2 and water. In the first half of the catalytic cycle, H2O2 oxidizes Fe(III) to the formally Fe(V) state commonly referred to as Compound I. The second half of the cycle entails oxidation of a second hydrogen peroxide molecule by Compound I to dioxygen. The present study employs density functional (DFT) calculations to examine the nature of this second step of the catalatic reaction. In order to account for the unusual choice of tyrosinate as an axial ligand in catalases, oxidation of hydrogen peroxide by an imidazole-ligated Compound I is also examined, bearing in mind that imidazole-ligated hemoproteins such as myoglobin or horseradish peroxidase tend to display little, if any, catalatic activity. Furthermore, in order to gauge the importance of the cation radical of Compound I in peroxide activation, the performance of Compound II (the one-electron reduced version of Compound I, formally Fe(IV) ), is also examined. It is found that hydrogen peroxide oxidation occurs in a quasi-concerted manner, with two hydrogen-atom transfer reactions, and that the tyrosinate ligand is in no way required at this stage. We propose that the role of the tyrosinate is purely thermodynamic, in avoiding accumulation of the much less peroxide-reactive ferrous form in vivo – all in line with the predominantly thermodynamic role of the cysteinate ligands in enzymes such as cytochromes P450.
Ionic self-assembly of porphyrin nanostructures on the surface of charge-altered track-etched membranes
Authors: Mongwaketsi Nametso , Ndungu Patrick G. , Nechaev Alexander , Maaza Malik , Sparrow Raymond
Published: July 2010

Track-etched polymer membranes are typically used as templates in the synthesis of various nanowires or nanotubes arrays. The unique advantages of track-etched membranes, such as uniform pore structure, excellent porosity, easily tailored pore sizes, and a well characterized surface chemistry, may find use in self-assembly strategies where colloidal nanostructures can be tethered to a suitable substrate to produce devices of interest. Meso-tetrakis(4-phenylsulfonicacid)porphyrin dihydrochloride and Sn(IV) tetrakis(4-pyridyl)porphyrin were used to synthesize ionic self-assembled porphyrin nanorods. The track-etched membranes surface charge was changed from negative to positive using polyethyleneimine. The porphyrin nanorods were either filtered through or self-assembled onto the surface of track-etched membranes. Comparisons were made with track-etched membranes modified with, and without, polyethyleneimine. Assembly of the porphyrin nanotubes only occurred on the surface of positively charged track-etched membranes, and filtration of the porphyrin nanorods produced a mesh-like structure on the surface of the membrane irrespective of the track-etched membrane pore diameter. In each case the characteristic absorbance profiles of the porphyrin nanorods was maintained. Transmission electron microscopy, scanning electron microscopy, atomic force microscopy, and UV-vis spectroscopy were used to characterize the various systems.
LOCAL MEAN AGES OF AIR IN A ROOM WITH MULTIPLE INLETS
Authors: HAN HWATAIK , SHIN CHEOL-YONG , LEE IN-BOK , KWON KYEONG-SEOK
Published: July 2010

This paper considers the age of air in a ventilated space with multiple supply inlets; the local mean age (LMA) of air is different from one inlet to another in multiple supply inlet situations. The purpose of this paper is to investigate theoretically the relations between the LMAs arising from each supply inlet and the overall combined LMA for all inlets. Transient concentration distributions are calculated using a CFD package in a simple room configuration with two inlets and one outlet, to verify the relations. Tracer gases are injected with a step-up method at each supply inlet individually, and at both inlets simultaneously. As a result, it can be found that the steady state concentration, with a continuous tracer injection at each supply inlet, works as a weighting factor for the corresponding LMA in calculating the overall combined LMA for the multiple inlet situations.
A FIELD APPLICATION CASE OF THE DIRECT ICE SLURRY TRANSPORTING SYSTEM FOR DISTRICT COOLING
Authors: YOO HOSEON , LEE SANG HOON , LEE YOON PYO
Published: July 2010

In order to investigate the feasibility of the direct ice slurry transporting system for the purpose of district cooling, a case study of field application is performed. The research aims to include the field measurement of ice packing factor, the performance of cold energy delivery, and the branching characteristics of ice slurry in which the additive is propylene glycol wt 10%. Two representative types of pipe branch are dealt with in this work. For the slurry flow with ice volume fraction of 0.16 or less, the pipe blocking due to aggregation is not observed. It is confirmed that the mass flow rate of ice slurry per unit cooling load markedly decreases with the increase of the ice content. The pumping power also decreases, but remains unchanged when the ice fractions are higher than a certain level.
EVALUATION OF THE SIMPLE THERMODYNAMIC MODEL (GORDON AND NG UNIVERSAL CHILLER MODEL) AS A FAULT DETECTION AND DIAGNOSIS TOOL FOR ON-SITE CENTRIFUGAL CHILLERS
Authors: SATHTHASIVAM JAYAPRAKASH , TANG GARY , NG KIM CHOON
Published: July 2010

The application of Fault Detection and Diagnosis (FDD) could play a key role in operating chillers at optimum efficiency. As air-conditioning consumes a significant proportion (approximately 30% to 50%) of the total power consumption of a commercial building, an effective FDD tool is very much required for a reliable and economic chiller operation. In this paper, the renowned Simple Thermodynamic Model, STM (also known as Gordon and Ng Universal Chiller Model) was utilized to detect and diagnose some of the common faults in centrifugal chillers. Based on the readily available, nonintrusive, steady state measurements extracted from the on-site chillers, the STM model was regressed to obtain two physically meaningful coefficients, namely, Thermal Resistance and Internal Entropy Generation. These information-rich coefficients were then analyzed to evaluate the performances and the conditions of the chillers. Despite the large and yet complex on-site chiller operations, equipped with built-in heat recovery, such as economizer and intricate control mechanisms, the predictive and diagnostic capabilities of STM in detecting chiller faults has been successfully tested and evaluated based on the data collected from on-site centrifugal chillers. Faults like condenser fouling and reduction in condenser cooling water flow rate were succinctly captured by the STM model.
STEADY STATE AND DYNAMIC MODELING OF AN INDIRECT DISTRICT HEATING SYSTEM
Authors: LI L. , ZAHEERUDDIN M. , CHO SUNG-HWAN , JUNG SANG-HOON
Published: July 2010

An indirect district heating system (IDHS) with heated floor area of 851 031 m2 and ten heat exchange stations was modeled in this study. An aggregated steady state model for the system was developed to study the impact of important system parameters. A dynamic model of the IDHS was developed based on energy balance principles. The dynamic model consists of sub-system models such as boiler, pipe network, heat exchanger, terminal heater and zone models. Simulation results of the dynamic responses show that the overall efficiency of the IDHS system is 78.7%, and the two highest heat loss components are the boiler heat losses and the secondary water makeup loss.
EXPERIMENTAL STUDY ON A NOVEL DEFROST CYCLE FOR AIR SOURCE HEAT PUMP
Authors: GUO XIAN-MIN , WANG YA-JING , FU WEN-CHENG , TAO XIANG-CHENG
Published: July 2010

On the basis of the hot-gas bypass defrost cycle, a new defrost method for air source heat pump is proposed. In the new defrost cycle, the outdoor heat exchanger is divided into two parts which are connected by a capillary tube. The front and rear parts of the heat exchanger are used as the evaporator and condenser respectively during defrosting, and can be defrosted orderly by using the four-way valve. The defrosting performance of the new cycle is investigated experimentally and the results are compared with that of the reverse-cycle defrost system. The experimental results indicate that the energy is used more efficiently in the new defrost cycle, therefore, the defrosting duration and losses are less than those of the reverse-cycle defrost system. Moreover, it does not extract heat from the indoor space during defrosting in terms of the new defrost cycle. Compared with the reverse-cycle defrost system, it is found that the switching times of the four-way valve in the new defrost system are the same, and the fluctuation of the discharge and suction pressures during the defrosting is much less than that in the reverse-cycle defrosting, hence, the mechanical impact on the system is much less.
Functional Context of Scent-Marking in Callithrix penicillata
Authors: Oliveira Danilo G.R. , Macedo Regina H.
Published: July 2010

Most mammals use olfactory signals for communicating identity, reproductive status and group-related dynamics. Callitrichids produce secretions as olfactory signals, the functional context of which is poorly known, especially in the wild. We analysed the functional significance of scent-marking in a free-ranging group of Callithrix penicillata in central Brazil. We recorded all occurrences of scent-marking according to context and conducted 10-min focal observations of adults and ‘scan sampling’ of the focal tree. We recorded the sex of scent-marking individuals and the location of occurrence within the home range, and found that there was no variation in rate of marking relative to either variable. However, females marked more along areas of contact with other groups in the home range and less in the core (non-contact) areas. Scent-marking in intergroup encounters, even when in agonistic contexts, was not associated with territorial disputes between groups. This suggests distinct functions for scent-marking for intra- versus intergroup communication. We also found a positive correlation between rate of scent-marking and height in the resource tree and between exudativory and air humidity.
How to Handle Genetic Information: A Comparison of Attitudes among Patients and the General Population
Authors: Wolff K. , Brun W. , Kvale G. , Ehrencrona H. , Soller M. , Nordin K.
Published: July 2010

Background: So far there are no studies comparing the attitudes of patients with hereditary conditions to the attitudes of the general public on how to handle genetic risk information which mutation carriers refuse to disclose to relevant family members. The purpose of the present study was to investigate whether such patients and members of the general public want to be informed about the existence of hereditary conditions within their family, and under which conditions they want healthcare providers to breach confidentiality. Methods: It was hypothesized that the desire to be informed would be influenced by characteristics of both the disease and the individual. Systematically varying 3 disease characteristics (fatality, penetrance and treatment availability) yielded 8 versions of a questionnaire, which was administered to general population samples in Norway and Sweden (N = 3,207) and to patient samples in both countries (N = 822). Individual differences in uncertainty avoidance, coping style and consideration for future consequences were also assessed. Results and Conclusion: A majority of both patients and the general public want to be informed about the existence of hereditary conditions within their family. However, patients are more positive towards being informed, both with and without the relative’s consent, than the general public. The main predictor of the desire to be informed was uncertainty avoidance in both samples.
Evaluation of the Symptomatic Treatment of Residual Neurological Symptoms in Wilson Disease
Authors: Hölscher Sara , Leinweber Barbara , Hefter Harald , Reuner Ulrike , Günther Peter , Weiss Karl Heinz , Oertel Wolfgang H. , Möller Jens Carsten
Published: July 2010

The intention of this analysis was to identify patients with treated Wilson disease (WD) and residual neurological symptoms in order to determine whether or not they were undergoing any treatment in addition to the common decoppering medication. Moreover, the effects of any symptomatic medication were analyzed. Two samples of WD patients were investigated either by a mailed questionnaire survey (n = 135) or by a retrospective analysis (n = 75). A considerable proportion of patients still suffered from neurological symptoms (n = 106, 50.5%), of whom a relatively small proportion was treated symptomatically (n = 33, 31.1%). The documented effects varied substantially, with anticholinergics and botulinum toxin (against dystonia) and primidone (against tremor) apparently being the most promising compounds. Further studies are required to analyze the symptomatic treatment of WD patients with residual neurological symptoms in more detail.
Downstream Exposure to Growth Factors Causes Elevated Velocity and Dilation in Arteriolar Networks
Authors: Georgi Melissa K. , Dewar Anthony M. , Frame Mary D.
Published: July 2010

Our goal was to characterize changes in flow and diameter with vascular endothelial cell growth factor A (VEGF-A) and fibroblast growth factor 2 (FGF2). Observations were made in arteriolar networks of the cheek pouch tissue in anesthetized hamsters (pentobarbital 70 mg/kg, i.p., n = 45). Local and remote dilation responses to micropipette-applied VEGF or FGF2 yielded similar EC50 values. The role of gap junctions in the remote response was tested by applying sucrose, halothane or 18αGA to the feed arteriole midway between the remote stimulation and upstream observation sites; all remote dilation to FGF2 was prevented, while only the early dilation to VEGF was blocked. The remote dilation to VEGF displayed a second rheologic mechanism. The second mechanism involved an abrupt increase in upstream velocity and shear rate, followed by nitro-arginine sensitive dilation. To test whether the abrupt increase in shear could be caused by other agents known to cause edema, remote responses to histamine and thrombin were tested. Each caused an abrupt increase in velocity followed by nitro-arginine-sensitive dilation. This study shows that VEGF or agents that increase permeability can initiate an upstream velocity increase with dilation that recruits flow to the network; this is in addition to simultaneous gap junction-mediated dilation.
Transcription Profiles of Aortic Smooth Muscle Cells from Atherosclerosis-Prone and -Resistant Regions in Young Apolipoprotein E-Deficient Mice before Plaque Development
Authors: Van Assche Tim , Hendrickx Jan , Crauwels Herta M. , Guns Pieter-Jan , Martinet Wim , Fransen Paul , Raes Martine , Bult Hidde
Published: July 2010

Background/Aims: Site-specific atherosclerosis is generally attributed to differential gene expression in endothelial cells. We investigated whether the transcriptome of smooth muscle cells is different between atherosclerosis-prone and atherosclerosis-resistant regions in apolipoprotein E-deficient (apoE–/–) mice before plaque development, and in C57Bl/6 mice. Methods: De-endothelialized aortas (both strains: 3 males, 3 females, age 4 months) were divided into atherosclerosis-prone (AA: ascending aorta, aortic arch and proximal 2 mm of thoracic aorta) and -resistant (CTA: central thoracic aorta, i.e. 6 mm distal from the proximal 2 mm) regions. The transcriptome of these two regions was compared using whole-genome mouse microarrays. Results: Microarray analysis revealed differential expression (>2-fold difference) of 70 and 244 genes in C57Bl/6 and apoE–/– mice. This was confirmed for 6 genes using the real-time quantitative polymerase chain reaction. Up- or downregulation in the AA was observed for 33 and 37 genes in C57Bl/6, and for 186 and 58 genes in apoE–/– mice, respectively. The 201 genes that showed exclusively differential expression in apoE–/– mice were related to atherosclerotic processes, such as cell adhesion, proliferation, differentiation, motility, cell death, lipid metabolism and immune responses. Conclusion: Our findings indicate that smooth muscle cells display an altered transcriptome at atherosclerosis-prone locations before actual lesion development.
Pro-Inflammatory Effects of Interleukin-17A on Vascular Smooth Muscle Cells Involve NAD(P)H- Oxidase Derived Reactive Oxygen Species
Authors: Pietrowski Eweline , Bender Bianca , Huppert Jula , White Robin , Luhmann Heiko J. , Kuhlmann Christoph R.W.
Published: July 2010

T cells are known for their contribution to the inflammatory element of atherosclerosis. Recently, it has been demonstrated that the Th17 derived cytokine IL-17 is involved in the pro-inflammatory response of vascular smooth muscle cells (VSMC). The aim of the present study was to examine whether reactive oxygen species (ROS) might be involved in this context. The effect of IL-17A on ROS generation was examined using the fluorescent dye 2′7′-dichlorodihydrofluorescein (H2DCF) in primary murine VSMC. IL-17A induced an increase in H2DCF fluorescence in VSMC, and this effect was blocked by the NAD(P)H-oxidase inhibitor apocynin and siRNA targeting Nox2. The p38-MAPK inhibitors SB203580 and SB202190 dose-dependently reduced the IL-17A induced ROS production. The IL-17A induced release of the pro-inflammatory cytokines IL-6, G-CSF, GM-CSF and MCP-1 from VSMC, as detected by the Luminex technology, was completely abolished by NAD(P)H-oxidase inhibition. Taken together, our data indicate that IL-17A causes the NAD(P)H-oxidase dependent generation of ROS leading to a pro-inflammatory activation of VSMC.
Vasopressin and Its Immune Effects in Septic Shock
Authors: Russell James A. , Walley Keith R.
Published: July 2010

Vasopressin is a stress hormone. However, vasopressin levels are inappropriately low in septic shock. Vasopressin stimulates AVPR1a, AVPR1b, AVPR2 and purinergic receptors. Vasopressin increases blood pressure by occupying AVPR1a receptors on vascular smooth muscle. An increase in ventricular afterload due to vasopressor administration limits ventricular systolic ejection, an effect that becomes increasingly important as systolic contractility is decreased. Stimulation of AVPR1a receptors may also decrease edemagenesis. Stimulation of AVPR1b by vasopressin releases ACTH and cortisol. AVPR2 stimulation increases retention of water by increasing cyclic AMP. Yet, vasopressin infusion may increase urine output, creatinine clearance and improve renal function in septic shock. Vasopressin has many effects on immune function such as altering cytokines, neuroimmunity, prostaglandins, humoral immunity and immune cells. For example, vasopressin decreases sepsis-induced pulmonary inflammation, could have renal anti-inflammatory effects and may decrease prostaglandin levels in a dose-dependent manner. Vasopressin may also modulate responses to stress by expression and release from immune cells. Interestingly, there are vasopressin receptors on immune cells. Many small clinical studies of vasopressin infusion in septic shock have shown that vasopressin infusion increases blood pressure, decreases requirements for norepinephrine and improves renal function. However, vasopressin could decrease coronary, cerebral and mesenteric perfusion. A multicenter trial of vasopressin versus norepinephrine in septic shock found no overall difference in mortality. Vasopressin may decrease mortality in patients with less severe septic shock. Vasopressin plus corticosteroid treatment may decrease mortality compared to corticosteroids plus norepinephrine. Potential mechanisms are that vasopressin plus corticosteroids beneficially alter immunity in septic shock.
Children’s rights education and social work: Contrasting models and understandings
Authors: Reynaert Didier , Bouverne-De Bie Maria , Vandevelde Stijn
Published: July 2010

Despite the adoption of the United Nations Convention on the Rights of the Child, the interest in developing a theoretical grounding for children’s rights education seems to be rather limited. This article argues for a better understanding of children’s rights education as a distinctive practice in social work. Two different conceptions of children’s rights education are identified: as an implementation strategy and as social action. Their relevance to both social work theory and practice are examined.
Rheology of Perfluorinated Polyether-based MR Fluids with Nanoparticles
Authors: Jonsdottir F. , Gudmundsson K.H. , Dijkman T.B. , Thorsteinsson F. , Gutfleisch O.
Published: July 2010

Motivated by the use of magneto-rheological (MR) technology in prosthetic devices, the goal of this study is to develop a MR fluid composition that is tailored for the requirements of a prosthetic knee actuator. A MR fluid composition is sought with a suitable balance between the field-induced shear stress, the off-state viscosity, and sedimentation stability for the proposed application. Rheological characteristics are investigated for samples with monodisperse micron-sized particles and bidisperse fluids with a mixture of micron- and nanosized particles. Two types of nanosized particles are used. All fluid samples employ a novel perfluorinated polyether oil as carrier liquid which enhances stability. The samples are investigated with respect to both field-induced and off-state characteristics. The results are compared to analytical and empirical models that exist in the literature. The monodisperse fluids are shown to give a favorable trade-off between field-induced strength and off-state viscosity. The addition of a small concentration of nanoparticles is found to moderately increase the field-induced shear-yield stress. However, for a larger concentration of nanoparticles, the yield stress begins to decrease. Nanoparticles exhibit an undesirable effect on the off-state viscosity. The results reveal valuable information for the designers of MR fluids and designers of prosthetic actuators.
HOLLOWS: A Power-aware Task Scheduler for Energy Harvesting Sensor Nodes
Authors: Piorno Joaquín Recas , Bergonzini Carlo , Atienza David , Rosing Tajana Simunic
Published: July 2010

Energy harvesting sensor nodes (EHSNs) have stringent low-energy consumption requirements, but they need to concurrently execute several types of tasks (processing, sensing, actuation, etc.). Furthermore, no accurate models exist to predict the energy harvesting income in order to adapt at run-time the executing set of prioritized tasks. In this article, we propose a novel power-aware task scheduler for EHSNs, namely, HOLLOWS: Head-of-Line Low-Overhead Wide-priority Service. HOLLOWS uses an energy-constrained prioritized queue model to describe the residence time of tasks entering the system and dynamically selects the set of tasks to execute, according to system accuracy requirements and expected energy. Moreover, HOLLOWS includes a new energy harvesting prediction algorithm, that is, weather-conditioned moving average (WCMA), which we have developed to estimate the solar panel energy income. We have tested HOLLOWS using the real-life working conditions of Shimmer, a sensor node for structural health monitoring. Our results indicate that HOLLOWS accurately predicts the energy available in Shimmer to guarantee a certain damage monitoring quality for long-term autonomous scenarios. Also, HOLLOWS is able to adjust the use of the incoming energy harvesting to achieve high accuracy for rapid event damage assessment (after earthquakes, fires, etc.).
Kindergarten attendance may reduce developmental impairments in children: Results from the Bavarian Pre-School Morbidity Survey
Authors: Caniato Riccardo N. , Alvarenga Marlies E. , Stich Heribert L. , Jansen Holger , Baune Berhard T.
Published: July 2010

Background: The relative risks and benefits of children attending kindergarten or pre-school remain uncertain and controversial. We used data from the Bavarian Pre-School Morbidity Survey (BPMS) to look at the prevalence of developmental impairments in pre-school children entering primary school and to assess if these were correlated with the duration of kindergarten attendance. Methods: We collected data from all school beginners in the district of Dingolfing, Bavaria from 2004 to 2007 (n = 4,005) and utilised a retrospective cross-sectional study design to review the information. The children were assessed for motor, cognitive, language and psychosocial impairments using a standardized medical assessment. Point prevalence of impairments of speech, cognition, motor functioning and psychosocial functioning were compared by χ2-test for the variable of time spent in kindergarten. Results: We detected a high incidence of impairments, with boys showing higher rates than girls in all the areas assessed. Longer length of time spent in kindergarten was associated with reduced rates of motor, cognitive and psychosocial impairments. There was no clear correlation between length of kindergarten attendance and speech disorders. Conclusions: Kindergarten attendance may have a positive effect on a number of domains of development including motor, cognitive and psychosocial development, but no significant effect on speech impairments. Implications for public health policies are discussed.
Review: Angiotensin II type 1 receptor blockers: class effects versus molecular effects
Authors: Miura Shin-ichiro , Karnik Sadashiva S. , Saku Keijiro
Published: July 2010

Highly selective angiotensin II (Ang II) type 1 (AT1) receptor blockers (ARBs) are now available. The AT1receptor is a member of the G protein-coupled receptor (GPCR) superfamily and block the diverse effects of Ang II. Several ARBs are available for clinical use. Most ARBs have common molecular structures (biphenyl-tetrazol and imidazole groups) and it is clear that ARBs have ‘class effects’. On the other hand, recent clinical studies have demonstrated that not all ARBs have the same effects, and some benefits conferred by ARBs may not be class effects, and instead may be ‘molecular effects’. In addition, each ARB has been clearly shown to have specific molecular effects in basic experimental studies, and these effects may be due to small differences in the molecular structure of each ARB. However, it is controversial whether ARBs have molecular effects in a clinical setting. Although the presence of molecular effects for each ARB based on experimental studies may not directly influence the clinical outcome, this possibility has not been adequately evaluated. This review focuses on the class effects versus molecular effects of ARBs from bench to bedside.
Surgical site infection following hip fracture surgery - the role of wound surveillance
Authors: Thyagarajan David , Sunderamoorthy Dakshinamurthy , Haridas Samarthjoy , Beck Sue , Praveen Pathmanaban , Johansen Anthony
Published: July 2010

In a prospective study we assessed 440 patients, sequentially admitted to the trauma unit with hip fracture. The superficial infection rate was 7.7% and the deep infection was 1.8%. The commonest organism responsible for surgical site infection was MRSA (47.6%). 45.2% of the patients with SSI and 50 % of the patients with MRSA wound infection were admitted from institutional care or other hospital. The high prevalence of MRSA wound infection and increased mortality rate in this subgroup highlights the need for a good surveillance programme in place, to monitor trends and identify risk factors with an emphasize on minimising infection rates. Using the National Hip Fracture Database (NHFD) to make surveillance for surgical site infection a routine part of hip fracture care would be best practice in monitoring the trend and comparing care and outcomes against national benchmarks and quality standards. We recommend a close surveillance of wound in this vulnerable group.
Platelet-derived growth factor (PDGF)–PDGF receptor interaction activates bone marrow–derived mesenchymal stromal cells derived from chronic lymphocytic leukemia: implications for an angiogenic switch
Authors: Ding Wei , Knox Traci R. , Tschumper Renee C. , Wu Wenting , Schwager Susan M. , Boysen Justin C. , Jelinek Diane F. , Kay Neil E.
Published: July 2010

Malignant cells are capable of influencing the microenvironment in a manner that facilitates tumor cell survival. Bidirectional crosstalk between chronic lymphocytic leukemic (CLL) cells and marrow-derived mesenchymal stromal cells (MSCs) activates both cell types. In this study, we observed that the conditioned medium (CM) obtained from CLL cells was able to induce Akt activation in MSC. Subsequent studies investigated the mechanism of MSC activation mediated by CLL-CM. Platelet-derived growth factor receptors (PDGFRs) were selectively activated in MSCs by CLL-CM and found to be critical receptors for CLL-CM–driven MSC proliferation and MSC Akt activation. The known ligands of PDGFR, platelet-derived growth factor (PDGF) and vascular endothelial growth factor (VEGF), were detected in CLL-CM, but PDGF was the predominant ligand involved in the CM-mediated PDGFR activation. Both PDGF and VEGF were found to be elevated in the plasma of CLL patients with a positive association for high-risk factors and more advanced stage. Finally, we demonstrated that PDGF induced MSC VEGF production through a phosphatidylinositol 3-kinase (PI3K)–dependent mechanism. These results show that PDGF-PDGFR signaling influences at least the MSC in the microenvironment of CLL and may play a role in the induction of an angiogenic switch known to be permissive for disease progression.
Patterns of nucleotides that flank substitutions in human orthologous genes
Authors: Ma Lei , Zhang Tingting , Huang Zhuoran , Jiang Xiaoqian , Tao Shiheng
Published: July 2010

Background

Sequence context is an important aspect of base mutagenesis, and three-base periodicity is an intrinsic property of coding sequences. However, how three-base periodicity is influenced in the vicinity of substitutions is still unclear. The effect of context on mutagenesis should be revealed in the usage of nucleotides that flank substitutions. Relative entropy (also known as Kullback-Leibler divergence) is useful for finding unusual patterns in biological sequences.

Results

Using relative entropy, we visualized the periodic patterns in the context of substitutions in human orthologous genes. Neighbouring patterns differed both among substitution categories and within a category that occurred at three codon positions. Transition tended to occur in periodic sequences relative to transversion. Periodic signals were stronger in a set of flanking sequences of substitutions that occurred at the third-codon positions than in those that occurred at the first- or second-codon positions. To determine how the three-base periodicity was affected near the substitution sites, we fitted a sine model to the values of the relative entropy. A sine of period equal to 3 is a good approximation for the three-base periodicity at sites not in close vicinity to some substitutions. These periods were interrupted near the substitution site and then reappeared away from substitutions. A comparative analysis between the native and codon-shuffled datasets suggested that the codon usage frequency was not the sole origin of the three-base periodicity, implying that the native order of codons also played an important role in this periodicity. Synonymous codon shuffling revealed that synonymous codon usage bias was one of the factors responsible for the observed three-base periodicity.

Conclusions

Our results offer an efficient way to illustrate unusual periodic patterns in the context of substitutions and provide further insight into the origin of three-base periodicity. This periodicity is a result of the native codon order in the reading frame. The length of the period equal to 3 is caused by the usage bias of nucleotides in synonymous codons. The periodic features in nucleotides surrounding substitutions aid in further understanding genetic variation and nucleotide mutagenesis.
Moxibustion for hypertension: a systematic review
Authors: Kim Jong-In , Choi Jun-Yong , Lee Hyangsook , Lee Myeong Soo , Ernst Edzard
Published: July 2010

Background

Moxibustion is a traditional East Asian medical therapy that uses the heat generated by burning herbal preparations containing Artemisia vulgaris to stimulate acupuncture points. The aim of this review was to evaluate previously published clinical evidence for the use of moxibustion as a treatment for hypertension.

Methods

We searched 15 databases without language restrictions from their respective dates of inception until March 2010. We included randomized controlled trials (RCTs) comparing moxibustion to either antihypertensive drugs or no treatment. The risk of bias was assessed for each RCT.

Results

During the course of our search, we identified 519 relevant articles. A total of 4 RCTs met all the inclusion criteria, two of which failed to report favorable effects of moxibustion on blood pressure (BP) compared to the control (antihypertensive drug treatment alone). However, a third RCT showed significant effects of moxibustion as an adjunct treatment to antihypertensive drug therapy for lowering BP compared to antihypertensive drug therapy alone. The fourth RCT included in this review addressed the immediate BP-lowering effects of moxibustion compared to no treatment. None of the included RCTs reported the sequence generation, allocation concealment and evaluator blinding.

Conclusion

There is insufficient evidence to suggest that moxibustion is an effective treatment for hypertension. Rigorously designed trials are warranted to answer the many remaining questions.