bluuebunny/crossref_metadata_2025 huggingface dataset:
Working and caring for a child with chronic illness: Barriers in achieving work-family balance
Authors: George Ajesh , Vickers Margaret H , Wilkes Lesley , Barton Belinda
Published: November 2010

This paper shares some findings from the initial, qualitative stage of a larger, national study currently being undertaken in Australia, exploring the experiences of parents who are working full-time and caring for a child with chronic illness. The findings highlight the limited support that most parents receive in their workplace, especially from employers. In-depth interviews revealed the negative and unsupportive attitude that employers had towards these parents. The provision of flexible work arrangements and leave entitlements, which were critical supports for these parents, were rarely offered by employers. Respondents reported high levels of frustration and difficulty balancing their dual roles.
Effects of dust deposition on iron cycle in the surface Mediterranean Sea: results from a mesocosm seeding experiment
Authors: Wagener T. , Guieu C. , Leblond N.
Published: November 2010

Abstract. Soil dust deposition is recognized as a major source of iron to the open ocean at global and regional scales. However, the processes that control the speciation and cycle of iron in the surface ocean after dust deposition are poorly documented mainly due to the logistical difficulties to investigate in-situ, natural dust events. The development of clean mesocosms in the frame of the DUNE project (a DUst experiment in a low Nutrient low chlorophyll Ecosystem) was a unique opportunity to investigate these processes at the unexplored scale of one dust deposition event. During the DUNE-1-P mesocosm seeding experiment, iron stocks (dissolved and particulate concentrations in the water column) and fluxes (export of particulate iron in sediment traps) were followed during 8 days after an artificial dust seeding mimicking a wet deposition of 10 g m−2. The addition of dust at the surface of the mesocosms was immediately followed by a decrease of dissolved iron [dFe] concentration in the 0–10 m water column. This decrease was likely due to dFe scavenging on settling dust particles and mineral organic aggregates. The scavenging ratio of dissolved iron on dust particles averaged 0.37 ± 0.12 nmol mg−1. Batch dissolution experiments conducted in parallel to the mesocosm experiment showed a increase (up to 600%) in dust iron dissolution capacity in dust-fertilized waters compared to control conditions. This study gives evidences of complex and unexpected effects of dust deposition on surface ocean biogeochemistry: (1) large dust deposition events may be a sink for surface ocean dissolved iron and (2) successive dust deposition events may induce different biogeochemical responses in the surface ocean.
Vascular Access Using the Superficial Femoral Vein
Authors: Scollay John M. , Skipworth Richard J.E. , Severn Alison , Nagy John , Howd Alison , Griffiths Gareth D.
Published: November 2010

Purpose

The superficial femoral vein (SFV) provides an alternative autologous conduit for fistula formation in patients who might otherwise require a prosthetic graft for hemodialysis (HD) access. The purpose of this study was to assess the results of this technique.

Methods

Patients who underwent formation of a SFV fistula were identified from a prospectively maintained database. Casenotes were reviewed for details of the operation, complications, subsequent interventions, and to determine whether the fistula was used for vascular access.

Results

Fifteen patients (seven males, eight females; median age 53, range 28–72 yrs) were identified. Patients had a median of four (range 2–9) previous fistulae. In three patients, the mobilized SFV was transferred to the upper limb while 12 patients had lower limb fistulae. Twelve patients (80%) used their SFV fistula for HD. Eleven patients developed a wound complication (infection, dehiscence, hematoma or bleeding), with four patients returning to theater for formal exploration and three requiring application of a vacuum dressing. Two patients developed post-operative lower limb ischemia. Two patients died during a median follow-up time of 7 (range 1–27) months.

Conclusion

In selected patients who have exhausted conventional routes for vascular access the SFV fistula can be used for the maintenance of HD. There is, however, significant associated morbidity and repeated intervention is often required.
Hemodialysis Vascular Access Ultrasonography: Tips, Tricks, Pitfalls and a Quiz
Authors: van Hooland Simon , Malik Jan
Published: November 2010

Duplex ultrasonography (DU) is a useful tool to optimize vascular access care in hemodialysis patients. However, the professional training of most healthcare workers caring for dialysis patients does not routinely include the teaching of DU (in this setting), thus limiting its use. The aim of this article is to provide some practical tips, tricks and potential pitfalls of this technique, both to the trainee ultrasonographer and to the healthcare worker already applying this technique in practice. The topics covered are 1) basic ultrasound principles (physics, machines and transducers), 2) the modes needed in vascular access DU in combination with the respective ways to optimize image quality, and 3) the assessment of access flow, stenosis and access induced ischemia by ultrasonography. This is done in the format of a quiz with 12 questions and answers.
VenaTrac™ Device for Over-the-Wire Placement of Chronic Dialysis Catheters
Authors: Mojibian Hamid R. , Oneal Patrice , Eliseo Donna , Tal Michael G.
Published: November 2010

Purpose

The VenaTrac™ is designed for exchange and primary placement of chronic tunneled hemodialysis catheters over a wire. It occludes both lumens of the catheter for the purpose of reducing the risk of air embolism and blood loss. The purpose of this paper is to report our experience with the use of this device.

Methods

A retrospective review of chronic hemodialysis dialysis catheters exchanges over a 30-month period was performed. Two hundred and ninety-seven over-the-wire catheter exchanges and 47 primary placements using the VenaTrac™ device were reviewed. In addition, 430 over-the-wire catheter exchanges without the use of the VenaTrac™ were reviewed.

Results

No insertional complications or air embolism occurred when using the VenaTrac™. Symptomatic air embolism was documented in 5 out of 430 catheter exchanges performed without the use of VenaTrac™ (1.2%).

Conclusions

VenaTrac™ over-the-wire insertion device demonstrated safe and reliable use with no incidence of air embolism.
Malnutrition, Infection and Arteriovenous Fistula Failure: Is There a Link?
Authors: Gagliardi Gian Manlio , Rossi Stefania , Condino Francesca , Mancuso Domenico , Greco Francesca , Tenuta Robert , Savino Olga , Bonofiglio Renzo , Domma Filippo , Latorre Giovanni
Published: November 2010

Introduction

The histology of neointimal hyperplasia, the primary cause of arteriovenous fistula (AVF) stenosis, resembles the histology of atherosclerosis. We evaluated classic atherogenic risk factors such as hypertension, smoking, diabetes, cholesterol, and evaluated the role of expanded risk factors such as: cytomegalovirus (CMV), Helicobacter pylori (H. pylori), Chlamydia pneumoniae (C. pneumoniae), infection, and malnutrition, as possible causes of AVF failure in hemodialysis (HD) patients.

Methods

AVF of 91 HD patients were monitored by on-line blood flow measurement (Qac); levels of albumin, fibrinogen, C-reactive protein and plasma cholesterol were recorded. Nutrition was evaluated via the Malnutrition Inflammation Score and the normalized protein intake (nPCR). Seropositivity to CMV, C. pneumoniae and H. Pylori were assessed.

Results

Twenty-one patients had at least one episode of vascular access thrombosis; 17 patients had stenotic lesions. Analysis of survival tables revealed that patients who had high IgG CMV antibody levels had a higher probability of AVF failure than patients with lower CMV antibody levels. The difference in the empirical survival functions was statistically significant when we stratified by CMV antibody levels, unlike H. pylori or C. pneumoniae. In a logistic regression model, CMV, increased cholesterol, and decreases in nPCR and Qac significantly increased the risk of AVF failure.

Conclusion

Our study suggests that CMV infection, total plasma cholesterol, decreased Qac, and nPCR are important risk factors of AVF failure in HD patients.
Explanation of Totally Implantable Venous Access Ports of the Forearm: Reasons for Removal and Observed Complications
Authors: Goltz Jan P. , Kickuth Ralph , Scholl Anne , Machann Wolfram , Ritter Christian O. , Hahn Dietbert , Wittenberg Günther
Published: November 2010

Purpose

To evaluate indications for, and complications during, explantation of interventionally placed totally implantable venous access ports (TIVAPs) of the forearm.

Background

Many studies analyze the explantation procedure of pectorally placed TIVAPs. The literature on TIVAPs in the forearm is limited, and the explantation procedure of these devices in the forearm has not been sufficiently evaluated yet.

Methods

We retrospectively reviewed the archives of our institute between May 2006 and May 2009 and identified 850 TIVAPs that had been implanted in the forearm. Of these TIVAPs, 145/850 (80 in women, 65 in men; mean age 52 years, range 15–82 years) were explanted during this period either by interventionists (n=109) or by general surgeons (n=36).

Results

Mean catheter survival was 322 days. Reasons for explantation were end of therapy (63.4%), infection (29.0%), thrombosis (3.4%), occlusion (1.4%), or dislocation (1.4%) of the TIVAP. Primary technical success rate was 97.2% for the surgical as well as for the interventional procedure. The overall success rate was 100%. The reasons for retrieval failure by interventionists (3/108) as well as by surgeons (1/36) were post-thrombotic adhesions of the port catheter to the blood vessel wall.

Conclusions

Removal of TIVAPs of the forearm shows a high technical success rate and a low complication rate. End of therapy is the most common indication for explantation. There is a low risk of interventional removal failure with a resulting need for open surgery to remove the device.
Central Venous Catheters in Neonates: From Simple Monolumen to Port Catheter
Authors: Caruselli Marco , Carboni Laura , Franco Federica , Torino Giovanni , Camilletti Gianfranco , Piattellini Gianmarco , Giretti Roberto , Pagni Raffaella
Published: November 2010

The use of Central Venous Catheters (CVCs) represents an important step in the management of the surgical, onco-hematology and critically ill patients.

CVCs in neonates, like in adult patients, are mainly used to infuse hyperosmolar solutions, to take blood samples and for hemodynamic monitoring.

The need for CVCs is higher in neonates than in adults.

Poor peripheral access and the high demand for IV access and blood samples are already valuable indications for a CVC.
Access Flow Reduction and Recurrent Symptomatic Cephalic Arch Stenosis in Brachiocephalic Hemodialysis Arteriovenous Fistulas
Authors: Arthur Miller Gregg , Friedman Alexander , Khariton Aleksandr , Preddie Dean C. , Savransky Yevgeny
Published: November 2010

Background

Recurrent cephalic arch stenosis (CAS) has been linked to high flow and has a high rate of recurrence following angioplasty. This study investigates the effectiveness of access flow reduction in decreasing rapidly recurrent symptomatic CAS.

Methods

A retrospective study of patient records from February 2005 to April 2009 was conducted. Patients with brachiocephalic fistulas who had undergone two or more instances of cephalic arch angioplasty within 3 months, and thereafter underwent flow reduction via banding of the access inflow (n=33) were included. A before-and-after analysis was conducted: the rates of cephalic arch angioplasty were calculated for each patient before and after the banding procedure, and compared via a paired t-test.

Results

At 3, 6, and 12 months, the cephalic arch primary lesion patency was 91%, 76%, and 57%. The cephalic arch intervention rate was reduced from 3.34 to 0.9 per access-year (t=7.74, p<.001). The average follow-up time was 14.5 months (range, 4.8–32).

Conclusion

Flow reduction of a brachiocephalic arteriovenous hemodialysis fistula may effectively diminish the incidence of symptomatic CAS.
Optimizing Hemodialysis Arteriovenous Fistula Maturation
Authors: Falk Abigail
Published: November 2010

Purpose

To review why hemodialysis fistulas fail to mature and how percutaneous techniques can salvage them.

Methods

A review of the medical literature was performed, with specific attention to the location of the lesions, the types and the numbers of procedures performed, salvage and patency rates.

Results

Using balloon angioplasty of the arteries and/or veins with sequential dilation if needed and ligation or embolization of collateral side branches the fistula that has failed to mature can be salvaged. Usually, more than one procedure is required to salvage a fistula; however, salvage rates of 75–95% are achieved with 1 yr primary patency rates of 30–60%. With repeat percutaneous interventions, 1 yr secondary patency rates are 75–90%.

Conclusions

With surveillance and aggressive follow-up after placement, early intervention (primarily dilation in the access circuit) can yield high salvage rates in fistulas that fail to mature.
Treatment of Dialysis Access-associated Steal Syndrome with the “Revision Using Distal Inflow” Technique
Authors: Callaghan Chris J. , Mallik Mekhola , Sivaprakasam Rajesh , Iype Satheesh , Pettigrew Gavin J.
Published: November 2010

Purpose

Dialysis access-associated steal syndrome (DASS) is a common, serious complication of antecubital fossa (ACF) arteriovenous fistulas (AVFs). We describe our experience of the “revision using distal inflow” (RUDI) technique for the treatment of DASS and review the literature.

Methods

Patients underwent fistula ligation at the anastomosis with re-establishment of inflow via the proximal radial or ulnar arteries using a venous interposition graft or venous collateral. A retrospective analysis of outcomes of all patients undergoing this procedure at our center was carried out.

Results

Seven patients with autogenous ACF AVFs underwent the RUDI procedure, four under local anesthesia. Interposition vein grafts were used in five patients, and inflow was achieved through the proximal radial artery in four cases. The median post-operative rise in digital systolic blood pressure was 65.5 mmHg. Follow-up at 7–36 months found that three fistulas had failed (one at 8 months, two within days), two patients had died with patent fistulas, one patient was transplanted with a functional AVF, and the remaining patient continues to dialyze through the fistula. No patients developed DASS postoperatively and no further interventions were required to maintain patency.

Conclusions

Although RUDI was successful at treating DASS, a high rate of AVF failure was seen. With technical modifications and further experience, RUDI may become a valuable tool in the surgical armamentarium.
Preclinical Results of a Prosthetic, Early-Stick Graft with Functional Endothelium
Authors: Hashi Craig K. , Glickman Marc H.
Published: November 2010

Purpose

The purpose of this study was to evaluate the NanoVasc Vascular Graft in comparison with a marketed expanded polytetrafluoroethylene (ePTFE) graft, both in vitro and in vivo. The graft was evaluated for use as both a bypass and arterio-venous (AV) access graft. Early-stick capabilities and patency were the primary end points evaluated.

Methods

Third party, independent laboratories completed mechanical testing, biocompatibility, and preclinical data collection. An ovine carotid artery interposition model and a canine femoral AV access model were used to evaluate 5–mm and 6–mm internal diameter sizes, respectively.

Results

There was no statistical difference in either model between the NanoVasc and ePTFE grafts with respect to patency. Time to hemostasis after cannulation with a 16–gauge needle was achieved ~10 times faster with the NanoVasc graft (mean time 27 seconds) compared with ePTFE. Histological analysis demonstrated functional endothelialization (nitric oxide expression), positive wound healing (cellular infiltration into the wall of the graft), and hemocompatibility of the NanoVasc graft.

Conclusions

The NanoVasc Vascular Graft is a strong candidate as a bypass and AV access graft. Its early-stick capabilities and patency rates are an attractive feature in comparison with current AV access grafts.
Prospective Clinical Evaluation of the Polyperf® Safe, a Safety Huber Needle, in Cancer Patients
Authors: Goossens Godelieve A. , Moons Philip , Jérôme Martine , Stas Marguerite
Published: November 2010

Purpose

Evaluation of the Polyperf® Safe (PPS) needle on safety and user-friendliness, as experienced by first-time and non-first-time users of the device.

Methods

A prospective, descriptive study was carried out at the University Hospitals Leuven, Belgium. Five hundred PPS needles were individually evaluated in cancer patients. Different aspects of the PPS were assessed: packaging, needle insertion, and needle removal. Nurses were asked whether they had previously inserted or removed this type of needle. We compared the PPS needle with the standard Gripper® needle in terms of safety, ease of use, and ease of training.

Results

Three hundred sixty-six evaluation forms were available for analysis (73.2%). Packaging and access evaluations were scored positively, except for two aspects: (1) needle stability, and (2) ease of dressing. Ease of removal was scored unsatisfactory in up to 22.4% of the registrations. Pain at insertion was reported in about 20% registrations, and blood contact was reported by 2.5% of non-first-time users. Safety was scored as good, although ease of use and ease in training scored 25.4% and 43.8%, respectively, lower than the Gripper®.

Conclusions

In general, nurses evaluated the PPS positively, with the exception of needle stability, ease of dressing, and ease of removal. No needlestick accidents were recorded. Aspects of ease of use and ease of training for PPS needles scored less than those for the Gripper® needles in up to one-third of the registrations.
Acalculous Cholecystitis in a Patient with Hepatocellular Carcinoma on Sorafenib
Authors: Sanda Mariko , Tamai Hideyuki , Deguchi Hisanobu , Mori Yoshiyuki , Moribata Kosaku , Shingaki Naoki , Ueda Kazuki , Inoue Izumi , Maekita Takao , Iguchi Mikitaka , Yanaoka Kimihiko , Oka Masashi , Ichinose Masao
Published: November 2010

A 67-year-old woman with compensated cirrhosis type B associated with hepatocellular carcinoma was started on sorafenib for multiple pulmonary metastases. The patient developed right upper quadrant pain and high fever 4 weeks later. Imaging revealed marked enlargement of the gallbladder without calculi. Following percutaneous transhepatic gallbladder aspiration, her symptoms resolved, but the gallbladder remained enlarged. Laparoscopic cholecystectomy was performed. Arteriolar occlusion with intimal thickening in the muscular layer of the gallbladder was seen sporadically. The fact that this patient had no risk factors for acalculous cholecystitis suggested that the cholecystitis resulted from ischemia, implying a strong causal relationship with sorafenib.
Anterior Crossbite Correction in Early Mixed Dentition Period Using Catlan's Appliance: A Case Report
Authors: Prakash Prashanth , Durgesh B. H.
Published: November 2010

Single tooth anterior dental crossbite is the commonly encountered malocclusion during the development of occlusion in children. Various treatment options such as removable and fixed appliances have been suggested by different authors in the past literature. This paper presents two cases of anterior crossbite corrected using the standard Catlan's appliance (Lower Inclined Bite Plane) in a short period of three weeks without any damage to the tooth or the periodontium. This fixed appliance is a simple and traditional method which does not depend on patient cooperation to reverse the bite.
Criminal thinking patterns, aggression styles, and the psychopathic traits of late high school bullies and bully‐victims
Authors: Ragatz Laurie L. , Anderson Ryan J. , Fremouw William , Schwartz Rebecca
Published: November 2010

This study explored the current psychological characteristics and criminal behavior history of individuals who retrospectively reported being bullies, bully‐victims, victims, or controls (i.e. neither victims nor bullies) during their last 2 years of high school. College students (n = 960) completed measures of criminal thinking, aggression, psychopathy, and criminal behavior online. We predicted bullies and bully‐victims would demonstrate the highest scores for criminal thinking, proactive aggression, psychopathy, and have the most criminal infractions. Bullies and bully‐victims had significantly higher scores on criminal thinking, aggression, psychopathy, and criminal behaviors than victims or controls. Additionally, men were significantly higher in criminal thinking, aggression, psychopathy, and had more criminal acts than women. There were no gender by bully group interactions. Logistic regression analyses differentiated bully‐victims from bullies. Bully‐victims tended to be male, higher in criminal thinking, and higher in reactive aggression. In addition, bully‐victims were distinct from victims, showing higher criminal thinking and higher proactive aggression. Aggr. Behav. 37:145–160, 2011. © 2010 Wiley‐Liss, Inc.
N‐acetylcysteine prevents loss of dopaminergic neurons in the EAAC1−/− mouse
Authors: Berman Ari E. , Chan Wai Yee , Brennan Angela M. , Reyes Reno C. , Adler Brittany L. , Suh Sang Won , Kauppinen Tiina M. , Edling Ylva , Swanson Raymond A.
Published: November 2010

Objective

Dopaminergic neuronal death in Parkinson's disease (PD) is accompanied by oxidative stress and preceded by glutathione depletion. The development of disease‐modifying therapies for PD has been hindered by a paucity of animal models that mimic these features and demonstrate an age‐related progression. The EAAC1−/− mouse may be useful in this regard, because EAAC1−/− mouse neurons have impaired neuronal cysteine uptake, resulting in reduced neuronal glutathione content and chronic oxidative stress. Here we aimed to (1) characterize the age‐related changes in nigral dopaminergic neurons in the EAAC1−/− mouse, and (2) use the EAAC1−/− mouse to evaluate N‐acetylcysteine, a membrane‐permeable cysteine pro‐drug, as a potential disease‐modifying intervention for PD.

Methods

Wild‐type mice, EAAC1−/− mice, and EAAC1−/− mice chronically treated with N‐acetylcysteine were evaluated at serial time points for evidence of oxidative stress, dopaminergic cell death, and motor abnormalities.

Results

EAAC1−/− mice showed age‐dependent loss of dopaminergic neurons in the substantia nigra pars compacta, with more than 40% of these neurons lost by age 12 months. This neuronal loss was accompanied by increased nitrotyrosine formation, nitrosylated α‐synuclein, and microglial activation. These changes were substantially reduced in mice that received N‐acetylcysteine.

Interpretation

These findings suggest that the EAAC1−/− mouse may be a useful model of the chronic neuronal oxidative stress that occurs in PD. The salutary effects of N‐acetylcysteine in this mouse model provide an impetus for clinical evaluation of glutathione repletion in PD. ANN NEUROL 2010
Natural Helicobacter infection modulates mouse intestinal muscularis macrophage responses
Authors: Hoffman Sara M. , Fleming Sherry D.
Published: November 2010

Helicobacter species are common laboratory pathogens which induce intestinal inflammation and disease in susceptible mice. Since in vitro studies indicate that Helicobacter products activate macrophages, we hypothesized that in vivo Helicobacter infection regulates the inflammatory response of intestinal muscularis macrophages from C57Bl/6 mice. Helicobacter hepaticus infection increased surface expression of macrophage markers F4/80, CD11b and MHC‐II within whole intestinal muscle mounts. However, constitutive cytokine and chemokine production by macrophages isolated from infected mice significantly decreased compared to macrophages from uninfected mice despite no detectable bacterial products in the cultures. In addition, muscularis macrophages from infected mice up‐regulated FIZZ‐1 and SK‐1 gene expression, suggesting the macrophages had an anti‐inflammatory phenotype. Corresponding with increased anti‐inflammatory gene expression, macrophages from infected mice were more phagocytic but did not produce cytokines after stimulation with LPS and IFN‐γ or immune complexes and IL‐4. Therefore, the presence of Helicobacter infection matures intestinal muscularis macrophages, modulating the constitutive macrophage response to become more anti‐inflammatory and resistant to secondary stimulation. Copyright © 2010 John Wiley & Sons, Ltd.
Furano‐1,2‐naphthoquinone inhibits EGFR signaling associated with G2/M cell cycle arrest and apoptosis in A549 cells
Authors: Su J. C. , Lin K. L. , Chien C. M. , Tseng C. H. , Chen Y. L. , Chang L. S. , Lin S. R.
Published: November 2010

Furano‐1,2‐naphthoquinone (FNQ), prepared from 2‐hydroxy‐1,4‐naphthoquinone and chloroacetaldehyde in an efficient one‐pot reaction, exhibits an anti‐carcinogenic effect. FNQ exerted anti‐proliferative activity with the G2/M cell cycle arrest and apoptosis in A549 cells. FNQ‐induced G2/M arrest was correlated with a marked decrease in the expression levels of cyclin A and cyclin B, and their activating partner cyclin‐dependent kinases (Cdk) 1 and 2 with concomitant induction of p53, p21, and p27. FNQ‐induced apoptosis was accompanied with Bax up‐regulation and the down‐regulation of Bcl‐2, X‐linked inhibitor of apoptosis (XIAP), and survivin, resulting in cytochrome c release and sequential activation of caspase‐9 and caspase‐3. Western blot analysis revealed that FNQ suppressed EGFR phosphorylation and JAK2, STAT3, and STAT5 activation, but increased in activation of p38 MAPK and c‐Jun NH2‐terminal kinase (JNK) stress signal. The combined treatment of FNQ with AG1478 (a specific EGFR inhibitor) significantly enhanced the G2/M arrest and apoptosis, and also led to up‐regulation in Bax, p53, p21, p27, release of mitochondrial cytochrome c, and down‐regulation of Bcl‐2, XIAP, survivin, cyclin A, cyclin B, Cdk1, and Cdk2 in A549 cells. These findings suggest that FNQ‐mediated cytotoxicity of A549 cell related with the G2/M cell cycle arrest and apoptosis via inactivation of EGFR‐mediated signaling pathway. Copyright © 2010 John Wiley & Sons, Ltd.
Application of AC‐SECM in Corrosion Science: Local Visualisation of Inhibitor Films on Active Metals for Corrosion Protection
Authors: Pähler Maike , Santana Juan José , Schuhmann Wolfgang , Souto Ricardo M.
Published: November 2010

The suitability of frequency‐dependent alternating‐current scanning electrochemical microscopy (4D AC‐SECM) for investigation of thin passivating layers covering the surface of corrosion‐inhibited metals has been demonstrated. Inhibition of copper corrosion by benzotriazole (BTAH) and methylbenzotriazole (MBTAH), which are effective inhibitors for this metal under many environmental conditions, was investigated. Strong dependencies were found for the AC z‐approach curves with both the duration of the inhibitor treatment and the frequency of the AC excitation signal applied in AC‐SECM. Both negative and positive feedback behaviours were observed in the AC approach curves for untreated copper and for Cu/BTAH and Cu/MBTAH samples. Negative feedback behaviour occurred in the low‐frequency range, whereas a positive feedback effect was observed at higher frequencies. A threshold frequency related to the passage from negative to positive regimes could be determined in each case. The threshold frequency for inhibitor‐modified samples was found always to be significantly higher than for the untreated metal, because the inhibitor film provides electrical insulation for the surface. Moreover, the threshold frequency increased with increasing surface coverage by the inhibitor. 4D AC‐SECM was successfully applied to visualizing spatially resolved differences in local electrochemical activity between inhibitor‐free and inhibitor‐covered areas of the sample.
Intramolecularly Coordinated Telluroxane Clusters and Polymers
Authors: Beckmann Jens , Bolsinger Jens , Duthie Andrew
Published: November 2010

The stoichiometrically controlled chlorination of the diarylditelluride (8‐Me2NC10H6Te)2 with SO2Cl2 afforded the aryltellurinyl chloride 8‐Me2NC10H6TeCl (1) and the aryltellurium trichloride 8‐Me2NC10H6TeCl3 (2). Alternatively, 1 was obtained by the reaction of the aryltellurenyl diethyldithiacarbamate 8‐Me2NC10H6Te(S2CNEt2) with hydrochloric acid. The base hydrolysis of 2 provided the novel telluroxanes (8‐Me2NC10H6Te)2OCl4 (3), (8‐Me2NC10H6Te)6O5Cl8 (4), (8‐Me2NC10H6Te)6O8Cl2 (5), [(8‐Me2NC10H6Te)2O3]n (6) and (8‐Me2NC10H6Te)6O8(OH)2 (7) depending on the reaction conditions applied. The reaction of 7 with ClTe(OiPr)3 in the presence of water gave rise to the telluroxane (8‐Me2NC10H6Te)6Te2O12Cl2 (8). The crystal and molecular structures of 1–3 and 5–8 were determined by X‐ray crystallography. The telluroxane clusters and polymers 6–8 hold potential as model compounds for alkali tellurite glasses (M2O)x(TeO2)1−x (M=Li, Na, K) for which no precise structural data are available.
One‐, Two‐ and Three‐Periodic Metal–Organic Rotaxane Frameworks (MORFs): Linking Cationic Transition‐Metal Nodes with an Anionic Rotaxane Ligand
Authors: Vukotic V. Nicholas , Loeb Stephen J.
Published: November 2010

A new singly charged pyridinium axle was prepared and combined with disulfonated dibenzo[24]crown‐8 ether to form a [2]pseudorotaxane. The reaction of this new, anionic ligand with ZnII ions, under various crystallization conditions, resulted in the formation of three metal–organic rotaxane framework (MORF) solids; a one‐periodic ML coordination polymer and two, two‐periodic ML2 square grid frameworks. The layers of square grids can be pillared to create full three‐perioidic MORF structures, which have completely neutral frameworks and are porous. These three‐perioidic materials represent the first examples of neutral porous MOFs in which one (or more) of the linkers is a mechanically interlocked molecule (MIM).
Stream processing on GPUs using distributed multimedia middleware
Authors: Repplinger Michael , Slusallek Philipp
Published: November 2010

Available GPUs provide increasingly more processing power especially for multimedia and digital signal processing. Despite the tremendous progress in hardware and thus processing power, there are and always will be applications that require using multiple GPUs either running inside the same machine or distributed in the network due to computationally intensive processing algorithms. Existing solutions for developing applications for GPUs still require a lot of hand‐optimization when using multiple GPUs inside the same machine and provide in general no or only limited support for using remote GPUs distributed in the network. In this paper we address this problem and show that an open distributed multimedia middleware, like the Network‐Integrated Multimedia Middleware (NMM), is able (1) to seamlessly integrate processing components using GPUs, while completely hiding GPU‐specific issues from the application developer, (2) to transparently combine processing components using GPUs or CPUs, and (3) to transparently use local and remote GPUs for distributed processing. Furthermore, we present a generic distribution framework to simplify the development of complex application scenarios. Copyright © 2010 John Wiley & Sons, Ltd.
Massively parallel systolic‐array architectures for 2d IIR polyphase space–time plane‐wave beam digital filters
Authors: Madanayake Arjuna , Gunaratne Thushara K. , Bruton Len T.
Published: November 2010

A systolic architecture has recently been proposed for implementing two‐dimensional infinite impulse response (IIR) space–time beam plane‐wave filters at a throughput of one‐frame‐per‐clock–cycle for such applications as real‐time broadband smart antennas. A novel polyphase systolic architecture is proposed here that further increases the throughput of these IIR beam filters, by a factor of M, to M‐frames‐per‐clock‐cycle, where M is the number of polyphases. The proposed method combines the polyphase approach, along with pipelining and look‐ahead optimization methods, to achieve frame sample frequencies that are several times higher than the clock‐cycle limit of the very large‐scale integration (VLSI) technology, thereby potentially allowing multi‐GHz frame sample frequencies using current custom VLSI circuits. The implementation of a field programmable gate array‐based real‐time prototype is described, tested and verified for the two‐phase case (M= 2) at a technology‐limited clock frequency of 50 MHz which corresponds to a throughput of 100 million‐frames‐per‐clock–cycle. Copyright © 2010 John Wiley & Sons, Ltd.
Low‐noise, low‐sensitivity, active‐RC allpole filters using impedance tapering
Authors: Jurisic Drazen , Moschytz George S. , Mijat Neven
Published: November 2010

In this paper it is shown that active‐RC filters whose sensitivity to component tolerances can be minimized by impedance tapering, will also have low output thermal noise. It is shown that impedance tapering will also reduce output thermal noise in OTA‐C filters. Copyright © 2010 John Wiley & Sons, Ltd.
Cursed by crude: the corporatist resource curse and the baku–tbilisi–ceyhan pipeline
Authors: Sovacool Benjamin K.
Published: November 2010

Based primarily on research interviews and field research, this article explores the impacts of the Baku–Tbilisi–Ceyhan (BTC) pipeline, which traverses Azerbaijan, Georgia and Turkey. The article first describes its research methods and links two separate strands of political economy literature to develop the notion of a corporatist resource curse. This concept suggests that when private and government actors partner to extract resources such as oil rapidly, the arrangement produces a system that consolidates wealth and ignores the interests of civil society and the public. The BTC pipeline illustrates the corporatist resource curse nicely, as its primary beneficiaries are a consortium of private companies and government elites, whereas various financial, humanitarian, environmental, social and legal impacts are felt throughout society at large. The article concludes by drawing out the implications of the BTC pipeline and the corporatist resource curse for public policy, energy development, infrastructure projects and corporate social responsibility. Copyright © 2010 John Wiley & Sons, Ltd and ERP Environment.
Semi‐explicit rate‐dependent modeling of damage‐avoidance steel connections using HF2V damping devices
Authors: Rodgers Geoffrey W. , Mander John B. , Chase J. Geoffrey
Published: November 2010

A rate‐dependent modeling technique is developed for moment resisting steel connections that utilize non‐linear viscous dampers. First, a model of the Maxwell‐type is developed that considers the non‐linear viscous damper and connection flexibility for translational motion. This model is compared with experimental results at several input motion frequencies to validate the results. The model is then extended to represent an exterior steel beam‐to‐column connection using damage‐avoidance design and non‐linear viscous dampers. By including terms to represent structural member and connection flexibility, using appropriate geometric transformations the model can be formulated to give the overall lateral load‐drift structural performance. Validation analysis shows good agreement between experimental observations and the model predictions. Copyright © 2010 John Wiley & Sons, Ltd.
Influence of cover thickness on the mechanical properties of steel bar in mortar exposed to high temperatures
Authors: Topçu İlker Bekir , Boğa Ahmet Raif , Demi̇r Abdullah
Published: November 2010

Concrete protects the steel inside against several effects of the external environment. One of the most important of these effects is high temperature. Cover plays a critical role in concrete's protection on reinforcement against high temperature. In this study, the changes after high temperatures in mechanical properties of the reinforcement steels placed between 3 and 5 cm covers inside the mortar specimen prepared with CEM I 42.5 R and CEM II/B‐M (P‐L) 32.5 R cements were investigated. In order to ensure 3 and 5 cm covers 76 × 76 × 310 and 116 × 116 × 350 mm sized reinforced mortar specimen were prepared. These reinforced mortar specimens were exposed to 20, 100, 200, 300, 500 and 800°C temperatures and after that on the steels taken out of these mortar specimen tensile strength, tests were applied in order to determine the mechanical properties. With the tensile strength tests performed stress–strain curves of the steel bars exposed to several temperatures were drawn. Besides, the yield and ultimate strengths of the steel bars were determined. The results of the study have shown that the larger the covers, the better the steel bars are protected against high temperatures. Copyright © 2010 John Wiley & Sons, Ltd.
A simplified calculation method for temperature evaluation of steel columns embedded in walls
Authors: Correia António M. , Rodrigues João Paulo C. , Silva Valdir P.
Published: November 2010

Steel elements behave differently in fire case when isolated or embedded in building walls. The walls on one hand have a favorable effect protecting the elements from the excessive heating resulting from the fire and on the other hand they have a detrimental effect due to the thermal gradients originated in the elements cross‐section. The simplified calculation methods proposed in EN 1993‐1‐2 for fire design do not take into account the case of steel elements embedded in walls, stipulating only a formulation for the assessment of the resistance for uniform temperature distribution. This paper presents a proposal of a new simplified calculation method to evaluate the temperature of steel columns embedded in walls. The method is based on numerical simulations and fire resistance tests. Steel columns totally or partially embedded in walls, with the web perpendicular or parallel to the wall surface, were tested.

In the study it was also observed that thicker walls or H steel columns with the web perpendicular to the wall surface provide greater thermal gradients in the cross‐sections. Copyright © 2010 John Wiley & Sons, Ltd.
Synthesis and characterization of thermoplastic composites filled with γ‐boehmite for fire resistance
Authors: Droval Guillaume , Aranberri Ibon , Ballestero Jesus , Verelst Marc , Dexpert‐Ghys Jeannette
Published: November 2010

This paper explores the use of boehmite as a fire retardant in low‐density polyethylene and polyamide 6. The structure and morphology of the filler are characterized by X‐ray diffraction and scanning electron microscopy. The water content of our boehmite is estimated about 30% by thermogravimetric analysis. The filler/matrix interactions in nanocomposites are investigated by means of thermo‐physical measurements: differential scanning calorimeter and thermogravimetry. The resulting morphology shows particles individually dispersed in the matrix. The fire tests present a fire‐resistance effect at low filler content despite a different behavior as a function of the matrix. For instance, with only 2% volume of boehmite, the burning time of LDPE composite is significantly increased by 15%. At the same filler content in PA6, the burning time is solely increased by 4.5%. On the other hand, the limiting oxygen index is increased by +7.0% (only 2.6% with LDPE composites). Copyright © 2010 John Wiley & Sons, Ltd.
Radiocarbon ages for coatings on cupules ground in quartzite bedrock at Rhino Cave in the Kalahari Desert of Botswana, and their paleoclimatic significance
Authors: Brook George A. , Railsback L. Bruce , Campbell Alec C. , Robbins Lawrence H. , Murphy Michael L. , Hodgins Greg , McHugh Joseph
Published: November 2010

Geophysical techniques have been widely employed for the noninvasive location of burial sites in archaeological and forensic investigations. This approach has met with varying degrees of success, depending on factors such as equipment choice, survey methodology, burial type, and geological setting. This paper reports the results of a multitechnique geophysical survey carried out immediately prior to the salvage excavation of two Indigenous burials from an eolian dune in coastal South Australia. Ground‐penetrating radar was not successful in defining the location of the burials owing to the disturbed nature of the local stratigraphy. Magnetic field intensity and apparent magnetic susceptibility surveys identified discrete anomalies that coincided with the location of skeletal material revealed during excavation, which we hypothesize to be due to burning or ochre use during funerary practices. Despite the spatial association of these features, subsequent laboratory analyses of the mineralogy and magnetic properties of sediments collected from the site failed to find a definite cause of the anomalies. Nevertheless, the association between them and the primary interment locations has implications for archaeological surveys carried out in the Australian coastal zone, as it highlights the potential of magnetic field intensity and apparent magnetic susceptibility geophysical techniques undertaken with a more refined survey methodology to afford a noninvasive, culturally appropriate means through which to detect Indigenous burials. This approach may prove particularly useful in areas with disturbed stratigraphy where ground‐penetrating radar is less effective. © 2010 Wiley Periodicals, Inc.
Hydrological field data from a modeller's perspective: Part 2: process‐based evaluation of model hypotheses
Authors: Clark Martyn P. , McMillan Hilary K. , Collins Daniel B. G. , Kavetski Dmitri , Woods Ross A.
Published: November 2010

The current generation of hydrological models has been widely criticized for their inability to adequately simulate hydrological processes. In this study, we evaluate competing model representations of hydrological processes with respect to their capability to simulate observed processes in the Mahurangi River basin in Northland, New Zealand. In the first part of this two‐part series, the precipitation, soil moisture, and flow data in the Mahurangi were used to estimate the dominant hydrological processes and explore several options for their suitable mathematical representation. In this paper, diagnostic tests are applied to gain several insights for model selection. The analysis highlights dominant hydrological processes (e.g. the importance of vertical drainage and baseflow compared to sub‐surface stormflow), provides guidance for the choice of modelling approaches (e.g. implicitly representing sub‐grid heterogeneity in soils), and helps infer appropriate values for model parameters. The approach used in this paper demonstrates the benefits of flexible model structures in the context of hypothesis testing, in particular, supporting a more systematic exploration of current ambiguities in hydrological process representation. The challenge for the hydrological community is to make better use of the available data, not only to estimate parameter values but also to diagnostically identify more scientifically defensible model structures. Copyright © 2010 John Wiley & Sons, Ltd.
Sub‐fossil Chironomidae as indicators of palaeoflow regimes: integration into the PalaeoLIFE flow index
Authors: Howard Lynda C. , Wood Paul J. , Greenwood Malcolm T. , Rendell Helen M. , Brooks Stephen J. , Armitage Patrick D. , Extence Chris A.
Published: November 2010

The sub‐fossil head capsules of larval Chironomidae have been widely exploited as palaeoecological indicators of lentic ecosystems but their value in the interpretation of the evolution of lotic systems has been underutilised by comparison. Recent research has demonstrated that the remains of Chironomidae are abundant within fluvial sequences and that they offer a valuable record of channel change and floodplain evolution that may complement that derived from existing biological and sedimentological techniques. This paper demonstrates the use of Chironomidae in characterising the palaeoflow regime of a large mid–late Holocene floodplain palaeochannel (5470–4960 to 1530–1350 cal. a BP) of the River Trent (Derbyshire, UK). Using expert knowledge and published information regarding flow preferences, larval Chironomidae were incorporated into the PalaeoLIFE (Lotic‐invertebrate Index for Flow Evaluation) methodology. The results clearly demonstrate that the sub‐fossil record provided by Chironomidae can be used to characterise changes in the flow regime within palaeochannel sections. At the scale of the channel section, species‐ and generic‐level ecological associations can provide useful information regarding habitat characteristics, including the presence of instream vegetation, mineral substrates and woody debris. The ability to undertake environmental reconstruction and channel evolution history was significantly enhanced through the application of a multi‐proxy approach, by incorporating other aquatic insect groups (Trichoptera and Coleoptera) into the PalaeoLIFE metric, together with sedimentological data. Copyright © 2010 John Wiley & Sons, Ltd.
Late Quaternary fluvial aggradation and incision in the monsoon‐dominated Alaknanda valley, Central Himalaya, Uttrakhand, India
Authors: juyal Navin , Sundriyal Yaspal , rana Naresh , chaudhary Shipra , Singhvi Ashok k.
Published: November 2010

The present study aims to explain the spatial and temporal variability in phases of aggradation/incision in response to changes in climate and seismicity during the late Quaternary in the Alaknanda River valley (a major tributary of the river Ganges or Ganga). Geomorphology, stratigraphy and optical dating of the fluvial sediment reveal that the oldest fluvial landforms preserved in the south of the Main Central Thrust are debris flow terraces developed during the early part of pluvial Marine Isotopic Stage 3. Following this, a period of accelerated incision/erosion owing to an increase in uplift rate and more intense rainfall occurred. In the Lesser Himalaya, three phases of valley fill aggradation around 26 ± 3 ka, 18 ± 2 ka and 15 ± 1 ka and 8 ± 1 ka occurred in response to changes in monsoon intensity and sediment flux. The last phase was regionally extensive and corresponds to a strengthening of the early Holocene Indian Summer Monsoon. A gradual decline in the monsoon strength after 8 ± 1 ka resulted in reduced fluvial discharge and lower sediment transport capacity of the Alaknanda River, leading to valley fill incision and the development of terraces. The study suggests that fluvial dynamics in the Alaknanda valley were modulated by monsoon variability and the role of tectonics was subordinate, limited to providing accommodation space and post‐deposition modification of the fluvial landforms. Copyright © 2010 John Wiley & Sons, Ltd.