bluuebunny/crossref_metadata_2025 huggingface dataset:
Theoretical analysis of laminar flow of power‐law fluids in coiled tubing
Authors: Zhou Y. , Shah S. N.
Published: July 2007

A comprehensive theoretical study of the flow of power‐law fluid in coiled tubing by using the boundary layer approximation method is presented. First, a boundary layer approximation analysis was applied to the governing equations of continuity and motion of a power law fluid in the curved tubing flow geometry. Momentum integral equations for the boundary layer flow were then derived and solved numerically. The resulting solutions of the velocity field were used to develop a new friction factor correlation in terms of generalized Dean number, coiled tubing curvature ratio, and flow behavior index of the power law fluid model. The new correlation of this study and a previous correlation by Mashelkar and Devarajan were evaluated using experimental data obtained from full‐scale coiled tubing flow experiments. An excellent agreement was found between the new correlation and the experimental results. The Mashelkar and Devarajan correlation did not result in any acceptable agreement with the experimental data, nor did it match the Ito correlation for the limiting case of Newtonian fluids (n = 1). This work extends the range of applicability of the new correlation to fluids with flow behavior indices as low as 0.25, which would cover most fluids used for coiled tubing operations in the oil and gas industry as well as fluids used in other industries. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Basal ganglia neurotransmitter concentrations in rhesus monkeys following subchronic manganese sulfate inhalation
Authors: Struve Melanie F. , McManus Brian E. , Wong Brian A. , Dorman David C.
Published: July 2007

Background

Manganese neurotoxicity in humans is recognized as a form of parkinsonism with lesions occurring predominantly within the globus pallidus, subthalamic nucleus, putamen, and caudate nucleus.

Methods

This study evaluated dopamine, 3,4‐dihydroxyphenylacetic acid, homovanillic acid, serotonin, norepinephrine, 5‐hydroxyindoleacetic acid, γ‐aminobutyric acid (GABA), and glutamate concentrations in the globus pallidus, caudate, and putamen of male rhesus monkeys exposed subchronically to either air or manganese sulfate (MnSO4) at 0.06, 0.3, or 1.5 mg Mn/m3.

Results

An approximate 1.5–6‐fold increase (vs. air‐exposed controls) in mean brain manganese concentration was observed following subchronic MnSO4 exposure. A marginally significant (P < 0.1) decrease in pallidal GABA and 5‐hydroxyindoleacetic acid concentration and caudate norepinephrine concentration occurred in monkeys exposed to MnSO4 at 1.5 mg Mn/m3.

Conclusions

Despite the presence of increased tissue manganese concentrations, high‐dose exposure to MnSO4 was associated with relatively few changes in basal ganglial neurotransmitter concentrations. Am. J. Ind. Med. 50:772–778, 2007. © 2007 Wiley‐Liss, Inc.
Characterization of temperature‐dependent moisture diffusivity in PMR‐15 resin
Authors: Yu Yunn‐Tzu , Pochiraju Kishore
Published: July 2007

The temperature‐dependent moisture diffusion behavior of high‐temperature polyimide resin, PMR‐15, is presented. Adsorption and high temperature desorption tests are used to experimentally determine moisture diffusivity at several temperatures. Diffusivity is determined from the weight change based on the initial slope and using a nonlinear regression technique with Fickian diffusion assumption. The basic test procedures and diffusivity values are presented in this study. The results also include the relative humidity (RH) dependent equilibrium moisture concentration and a relationship between the RH and equilibrium moisture concentration. As direct measurement at typical operating temperature may be precluded by blistering, an Arrhenius‐type temperature‐diffusivity relationship is used to estimate the temperature‐dependent moisture diffusivity for the PMR‐15 resin. The moisture diffusivity of PMR‐15 tested is estimated to be 6.64 E −10 m2/s at 288°C. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Synthesis and characterization of poly(butylene terephthalate)/mica nanocomposite fibers via in situ interlayer polymerization
Authors: Chang Jin‐Hae , Mun Mu Kyung , Kim Jeong‐Cheol
Published: July 2007

Intercalated nanocomposites consisting of poly(butylene terephthalate) (PBT) incorporated between mica layers were synthesized from dimethyl terephthalate (DMT) and 1,4‐butanediol (BD) by in situ interlayer polymerization. PBT nanocomposites of varying organoclay content were melt‐spun to produce monofilaments. The samples were characterized using wide angle X‐ray diffraction, electron microscopy, thermal analysis, and tensile testing. Some of the clay particles were found to be well dispersed in the PBT matrix, but other clay particles were agglomerated at a size level greater than approximately 20 nm. The glass transition temperatures (Tg) and the thermal degradation properties (TDi) of undrawn PBT hybrid fibers were found to improve with increases in the clay content. At draw ratio (DR) = 1, the ultimate tensile strengths of the hybrid fibers increased with the addition of clay up to a critical content and then decreased. However, the initial moduli monotonically increased with increases in the amount of organoclay in the PBT matrix. The ultimate strengths were found to decrease linearly with increases in DR from 1 to 18. In contrast to the trend for the tensile strengths, the initial moduli of the hybrid fibers increased only slightly with increases in DR up to 18. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Flame‐retardant polyesters. II. Polyester polymers
Authors: Yang Seung‐Cheol , Kim Jae Pil
Published: July 2007

Two flame‐retardant polyesters were polymerized with two types of phosphorous flame retardants. 3‐(Hydroxyphenyl phosphinyl)propanoic acid (HPP) was used as a main‐chain type, and 9,10‐dihydro‐9‐oxa‐10‐2,3‐dicarbonylpropyl‐10‐phosphophenanthrene‐10‐oxide (DI) was used as a pendant type. Polymerization was accomplished on a commercial scale with a three‐reactor system to exclude the compositional variation of oligomeric ethylene terephthalate. A longer polycondensation time and a higher dosage of the catalyst were necessary for DI with respect to HPP because of the high content and relatively low reactivity of the flame retardant. However, the content of diethylene glycol (DEG) in the polyester, which formed during the polymerization, was much higher in the case of HPP. The produced polyesters had almost the same molecular weight, but the DEG contents in the polyesters were quite different. The higher DEG content in the HPP polyester reduced the thermal stability. The greater flexibility of the HPP polyester chain resulted in easier crystallization and a lower crystalline temperature. The HPP polyester had higher susceptibility to thermal degradation because of low resistance to thermal chain scission, degraded at a lower temperature, and was more easily degraded because of a weak PO bond linkage in the main chain. The DI polyester, whose phosphorous atom was highly sterically hindered, showed better alkaline resistance than the HPP polyester because of the lower acidity and lower hydrophilic DEG content. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Production of biodiesel: possibilities and challenges
Authors: Al‐Zuhair Sulaiman
Published: July 2007

Biodiesel, defined as monoalkyl fatty acid ester (preferentially methyl and ethyl esters), represents a promising alternative fuel for use in compression‐ignition (diesel) engines. Biodiesel fuel comes from renewable sources as it is plant‐ not petroleum‐derived and as such it is biodegradable and less toxic. In addition, relative to conventional diesel, its combustion products have reduced levels of particulates, carbon oxides, sulphur oxides and, under some conditions, nitrogen oxides. Enzymatic production of biodiesel has been proposed to overcome the drawbacks of the conventional chemically catalyzed processes. The main obstacle facing full exploitation of the enzyme, lipase, potential is its cost. Therefore, reuse of lipase is essential from the economic point of view, which can be achieved by using the lipase in immobilized form. In addition, immobilized lipase displays improved stability and activity. Common immobilization techniques include attachment to solid supports and entrapment within the matrix of a polymer. This article presents a comparison between conventional processes and enzymatic processes and different possible feedstocks for biodiesel production. In addition, possible ways to overcome the problems facing the use of lipase are described. © 2007 Society of Chemical Industry and John Wiley & Sons, Ltd
Cancer genome sequencing: The challenges ahead
Authors: Heng Henry H.Q.
Published: July 2007

A major challenge for The Cancer Genome Atlas (TCGA) Project is solving the high level of genetic and epigenetic heterogeneity of cancer. For the majority of solid tumors, evolution patterns are stochastic and the end products are unpredictable, in contrast to the relatively predictable stepwise patterns classically described in many hematological cancers. Further, it is genome aberrations, rather than gene mutations, that are the dominant factor in generating abnormal levels of system heterogeneity in cancers. These features of cancer could significantly reduce the impact of the sequencing approach, as it is only when mutated genes are the main cause of cancer that directly sequencing them is justified. Many biological factors (genetic and epigenetic variations, metabolic processes) and environmental influences can increase the probability of cancer formation, depending on the given circumstances. The common link between these factors is the stochastic genome variations that provide the driving force behind the cancer evolutionary process within multiple levels of a biological system. This analysis suggests that cancer is a disease of probability and the most‐challenging issue to the TCGA project, as well as the development of general strategies for fighting cancer, lie at the conceptual level. BioEssays 29:783–794, 2007. © 2007 Wiley Periodicals, Inc.
A theoretical framework for CNS arousal
Authors: Pfaff Donald , Banavar Jayanth R.
Published: July 2007

Rapid changes of state in central nervous systems (CNS), as required following stimuli that must arouse the CNS from a quiescent state in order to activate a behavioral response, constitute a particularly appropriate application of non‐linear dynamics. Chaotic dynamics would provide tremendous amplification of neuronal activity needed for CNS arousal, sensitively dependent on the initial state of the CNS. This theoretical approach is attractive because it supposes dynamics that are deterministic and it links the elegant mathematics of chaos to the conception of a fundamental property of the CNS. However, a living system must be able to exit from chaotic dynamics in order to avoid widely divergent, biologically impossible outcomes. We hypothesize that, analogous to phase transitions in a liquid crystal, CNS arousal systems, having ‘woken up the brain’ to activate behavior, go through a phase transition and emerge under the control of orderly movement control systems. BioEssays 29:803–810, 2007. © 2007 Wiley Periodicals, Inc.
Cerebral ischemia, cell cycle elements and Cdk5
Authors: Timsit Serge , Menn Bénédicte
Published: July 2007

Stroke is a devastating disorder that significantly contributes to death, disability, and healthcare costs. New therapeutic strategies have been recently focusing on the development of neuroprotective agents that could halt the underlying mechanisms of neuronal death leading to brain damage. Accumulating evidence implicates proteins that are normally involved in the regulation of the cell cycle to neuronal death following ischemic insult, suggesting that these proteins could be suitable targets for stroke therapy. In this brief review, we present in vitro and in vivo arguments linking cell cycle molecules, i.e., cyclins, mitotic cyclin‐dependent kinases (Cdks), as well as non‐mitotic Cdk5, to ischemic neuronal death. We also report the evaluation of the potential of Cdk inhibitors as neuroprotective strategy for ischemic injury.
Facets of psychopathy, Axis II traits, and behavioral dysregulation among jail detainees
Authors: Rogers Richard , Jordan Mandy J. , Harrison Kimberly S.
Published: July 2007

Forensic evaluations of offender populations often consider psychopathy as an integral component of these consultations. Vexing issues remain of whether psychopathic traits should be evaluated consistently irrespective of demographic characteristics (e.g. gender), comorbidity (e.g. other Axis II pathology), or setting (e.g. jail or community). The current study examined gender differences for psychopathy and Axis II traits in a nonreferred jail sample of predominantly nonviolent offenders. Participants with moderate to high levels of psychopathy evidenced substantial comorbidity, especially with Cluster B personality disorders. Facets of psychopathy and Axis II traits varied substantially across both genders. In addition, the research evaluated Lynam's Hyperactivity, Impulsivity, and Attention difficulties (HIA) model of psychopathy. These initial data found little support for the HIA model in this jail sample. In testing competing hypotheses, the HIA model was substantially better at predicting Cluster B traits than psychopathy per se. Copyright © 2007 John Wiley & Sons, Ltd.
The place and function of power in community psychology: philosophical and practical issues
Authors: Fisher Adrian T. , Sonn Christopher C. , Evans Scot D.
Published: July 2007

Much of the training of psychologists in the western world follows a logical positivist, scientist‐practitioner model based in scientific objectivity and removed from politics. In this paper, we explore issues around alternative understandings of the role and place of psychologists and psychological actions. In so doing, we discuss a number of issues of ontology, epistemology and pragmatics to demonstrate that the role and function of power in our society need to be addressed more directly and more politically in order for us to successfully achieve our roles as community psychologists. Copyright © 2007 John Wiley & Sons, Ltd.
Long‐term outcome of simultaneous kissing stenting technique with sirolimus‐eluting stent for large bifurcation coronary lesions
Authors: Kim Young‐Hak , Park Duk‐Woo , Suh Il‐Woo , Jang Jae‐Sik , Hwang Eui‐Seock , Jeong Young‐Hoon , Lee Se‐Whan , Lee Seung‐Whan , Lee Cheol Whan , Hong Myeong‐Ki , Kim Jae‐Joong , Park Seong‐Wook , Park Seung‐Jung
Published: July 2007

Objectives:

This study was conducted to evaluate the outcomes of simultaneous kissing stenting with sirolimus‐eluting stent (SES).

Background:

Percutaneous intervention for bifurcation coronary lesions is still challenging.

Methods:

This study was designed to evaluate the long‐term outcomes of 36 consecutive patients with large bifurcation coronary lesions who underwent simultaneous kissing stenting with SES.

Results:

Lesion location was unprotected left main in 29 patients (81%) and anterior descending artery in 7 (19%). The patients received a combination of aspirin and clopidogrel for 6 months and cilostazol for 1 month. Mean proximal reference diameter was 4.05 ± 0.68 mm. Compared with the side branch (SB), the main vessel (MV) involved longer lesions (25.8 ± 17.0 mm vs. 10.2 ± 10.8 mm, P < 0.001) and smaller preprocedural minimal lumen diameters (1.02 ± 0.53 mm vs. 1.46 ± 0.78 mm, P = 0.006) and was treated with larger stents (3.1 ± 0.3 mm vs. 3.0 ± 0.3 mm, P = 0.006). Angiographic success rate was 100%. Over the follow‐up of 26.7 ± 8.6 months, no deaths, myocardial infarctions or stent thromboses occurred. Target lesion revascularization was performed in five patients (14%). Overall angiographic restenosis occurred in 5/30 patients (17%), consisting of 4 (13%) at MV and 3 (10%) at SB. At follow‐up angiography, a membranous diaphragm at the carina was identified in 14 patients (47%), but only one of whom was associated with angiographic restenosis.

Conclusion:

Simultaneous kissing stenting with SES appears a feasible stenting technique in large bifurcation coronary lesions. However, a new angiographic structure of carinal membrane developed in a half of patients at follow‐up and its influence needs to be further investigated. © 2007 Wiley‐Liss, Inc.
New transcatheter techniques for creation or enlargement of atrial septal defects in infants with complex congenital heart disease
Authors: Pedra Carlos A.C. , Neves Juliana R. , Pedra Simone R.F. , Ferreiro Carlos R. , Jatene Ieda , Cortez Tâmara M. , Jatene Marcelo , Souza Luis Carlos B. , Assad Renato , Fontes Valmir F.
Published: July 2007

Objectives:

To describe a series of 8 consecutive infants (5 with transposition of the great arteries [TGA] and 3 with hypoplastic left heart syndrome [HLHS]) who underwent nonconventional septostomy techniques.

Background:

For some complex congenital heart defects, an unrestrictive atrial septal defect (ASD) is essential to achieve an adequate cardiac output and/or systemic saturation. In some scenarios, the use of conventional septostomy techniques may be technically difficult, hazardous, and/or ineffective.

Methods:

Use of transhepatic approach, cutting balloons, and radiofrequency perforation with stenting of the atrial septum.

Results:

The size of the ASD and the oxygen saturation increased in all patients with no major complications. In those with TGA, the ASDs were considered to be of good size at the arterial switch operation. Two of the 3 patients with hybrid palliation for HLHS have developed some degree of obstruction within the interatrial stent over 2–3 months. At surgery, the stents were found to be secured within the septum with one showing significant fibrous ingrowth after uneventful removal. The other had some nonobstructive ingrowth.

Conclusions:

Creation or enlargement of ASDs in infants using new nonconventional transcatheter techniques is feasible, safe, and effective, at least in the short‐to‐mid‐term follow‐up. Infants with TGA seem to benefit the most because the procedure results in satisfactory clinical stability for subsequent early surgical intervention. In infants with HLHS palliated by a hybrid approach, stent implantation to the atrial septum seems to buy enough time to bring them to the phase II safely despite progressive in‐stent obstruction. © 2007 Wiley‐Liss, Inc.
Transcatheter closure of high‐risk muscular ventricular septal defects with the CardioSEAL occluder: Initial report from the CardioSEAL VSD Registry
Authors: Lim D. Scott , Forbes Thomas J. , Rothman Abraham , Lock James E. , Landzberg Michael J.
Published: July 2007

Objectives:

The CardioSEAL VSD registry was created to track safety of the device to close high‐risk Ventricular Septal Defect (VSD).

Background:

This is the first report from the multi‐centered CardioSEAL VSD registry reviewing demographics and initial results.

Methods:

Centers recruited patients with VSD who were high‐risk for surgery due to medical condition or anatomic features.

Results:

18 centers contributed data on 55 high‐risk patients who had 61 VSD‐occlusion procedures, with age of range of 5 days to 65 years and using one to six devices. Implantation approach was transvenous in 48, perventricular in five, and by combined approach in two patients. Ninety‐two percent of intended VSD device implants were judged successful. Twenty‐two patients had single VSD closed by single device in 18 and by two devices in four patients. All patients <8 kg underwent perventricular device implantation. Thirty‐three patients had multiple VSDs which were closed by a single device in 23, and multiple devices in 10. At discharge echocardiography showed total residual flow through all VSDs in which devices were used was classified as “Small” or less in 74%, “More than small” in 11%, and “Uncertain” in 15%. Eight major adverse events occurred in 5/61 cases (8% event rate), with 3/81 devices embolized (4% embolization rate), 5/81 devices surgically explanted (6% explant rate), and no deaths judged to be procedure‐related.

Conclusion:

This initial report from the multi‐centered CardioSEAL VSD registry demonstrates the safety of the device to close high‐risk VSDs. © 2007 Wiley‐Liss, Inc.
Three‐dimensional rotational digital angiography in a complicated case of patent ductus arteriosus transcatheter closure
Authors: Rigatelli Gianluca , Zamboni Alberto , Cardaioli Paolo
Published: July 2007

There has been no report so far as to the usefulness of 3D rotational angiography in congenital heart disease interventions. We present a case of a difficult patent ductus arteriosus in which 3D rotational angiography was the key to successful closure. A 64‐year‐old woman who had been operated on many years previously for a patent ductus arteriosus came to our attention for a heart murmur on the left upper sternal border. Echocardiography revealed a still patent duct with moderate shunt. The patient underwent cardiac magnetic resonance imaging, which confirmed patency of the duct, but its diameter and length were difficult to measure due to the particular orientation and morphology of the previously legated duct. It was decided to attempt device closure. Three‐dimensional rotational digital subtraction technique enabled us to find the most useful projection for measuring the duct and selecting the best implant device (coil or Amplatzer device). The exact oblique and cranio‐caudal degree of the selected projection on rotational 3D reconstruction was replicated to obtain the best standard digital subtraction angiographic view of the duct. Thus, a 5/4‐mm Amplatzer Duct Occluder was selected and successfully implanted with excellent results. This case suggests that 3D rotational angiography may be an important imaging tool to guide congenital heart disease interventions such as patent ductus arteriosus closure or aortic coarctation repair. © 2007 Wiley‐Liss, Inc.
Day procedure intervention is safe and complication free in higher risk patients undergoing transradial angioplasty and stenting. The discharge study
Authors: Small Andrew , Klinke Peter , Della Siega Anthony , Fretz Eric , Kinloch David , Mildenberger Richard , Williams Malcolm , Hilton David
Published: July 2007

Objectives:

To assess the timeframe of postprocedural complications following transradial percutaneous intervention in selected nonlow‐risk risk patients as a feasibility study for same day discharge.

Background:

Percutaneous coronary intervention (PCI) is traditionally performed as an inpatient procedure. Transradial access with its lower complication rate facilitates safe and same day discharge. We hypothesize that with current standards of pharmacotherapy and intervention, complications post transradial percutaneous coronary angioplasty even in a nonlow‐risk patient cohort will be evident within 6 hr or occur more than 24 hr post procedure. Under these circumstances, overnight stay results in no improvement in patient safety.

Methods:

2,189 patients underwent transradial PCI at our institution between January 2005 and June 2006. Of these 1,174 were assessed as intermediate or high risk and admitted postprocedure. The remaining 1,015 were assessed as low risk and discharged the day of procedure. All 1,174 inpatients were entered into our study database. Information was collected on patient demographics, angiographic characteristics, post procedural complications, and timing of post procedural events.

Results:

1,543 ACC type B2 or C lesions were treated in 1,174 patients. All post‐procedural complications were identified within 6 hr of the intervention or occurred more than 24 hr later when patients would have been discharged according to overnight admission protocols.

Conclusions:

Day case transradial percutaneous intervention with a 6‐hr period of post procedure observation is a safe and feasible practice. The presence of higher‐risk features should not be considered an absolute indication for overnight admission in patients considered clinically appropriate for discharge. © 2007 Wiley‐Liss, Inc.
Acute myocardial infarction and underlying stenosis severity
Authors: Frøbert Ole , van't Veer Marcel , Aarnoudse Wilbert , Simonsen Ulf , Koolen Jacques J. , Pijls Nico H.J.
Published: July 2007

Objectives:

The objective of this study was to investigate the underlying stenosis severity of the culprit lesion in acute myocardial infarction.

Background:

It is widely believed that myocardial infarction often occurs in angiographically mild luminal stenosis. This, however, is in contradiction with experience from interventional practice in primary PCI.

Methods:

We performed quantitative coronary angiography (QCA) in 250 consecutive patients referred for acute percutaneous coronary intervention (PCI) because of acute myocardial infarction (AMI). Fundamental for analysis was that a realistic estimate of underlying luminal narrowing before the infarction could be made angiographically that QCA could be performed and that one of two criteria was met: (1) spontaneous reflow allowing assessment of the lumen proximal and distal to the culprit lesion, or (2) coronary artery closed at arrival but reflow after uncomplicated wiring allowing assessment of the lumen proximal and distal to the culprit lesion.

Results:

Of 250 consecutive patients (mean age 61.7 ± 12.7 years, 48 women) referred for acute PCI, 156 patients (62%) fulfilled at least one of the above criteria for reliable QCA. In 151 of these patients (96%) the severity of the underlying stenosis was >50% and in 103 (66%) it was >70%. There were no differences in stenosis severity between the left anterior descending [LAD, (72 ± 13)%, n = 57], left circumflex [Cx, (74 ± 10)%, n = 20], and right coronary artery territory [RCA, (74 ± 12)%, n = 76] (ANOVA, P = 0.76). There were no differences in stenosis severity between women [(73 ± 13)%, n = 36] and men [(75 ± 11)%, n = 120; P = 0.35].

Conclusion:

In contrast to what is often believed, the majority of myocardial infarctions occurs in significant stenosis. © 2007 Wiley‐Liss, Inc.
Novel gradient coils designed using a boundary element method
Authors: Poole Michael , Bowtell Richard
Published: July 2007

Boundary element methods offer a powerful approach for designing gradient coils, allowing the generation of coils wounds on arbitrarily shaped surface so as to produce any form of field variation that is consistent with Maxwell's equations. These methods are based on meshing the current carrying surface into an array of boundary elements. In this work, we have extended boundary element methods that have previously been used used for coil design and integrated a powerful mesh generating program so as to produce coils with totally arbitrary geometry. Four examples are used to illustrate how the modified method provides a single versatile coil design protocol. These relate to the design of: i) shielded head gradients with highly asymmetric surface geometry that give the highest possible gradient field strengths; ii) very short, shielded gradient coils to allow improved access to the subject; iii) bi‐planar coils generating highly asymmetric, stepped magnetic fields for use in fast imaging by multiple acquisition with micro‐B0 arrays (MAMBA); iv) an insertable set of head gradient coils with shoulder cut‐outs. © 2007 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 31B: 162–175, 2007
Differences in breast carcinoma characteristics in newly diagnosed African–American and Caucasian patients
Authors: Morris Gloria J. , Naidu Sashi , Topham Allan K. , Guiles Fran , Xu Yihuan , McCue Peter , Schwartz Gordon F. , Park Pauline K. , Rosenberg Anne L. , Brill Kristin , Mitchell Edith P.
Published: July 2007

BACKGROUND

Breast carcinomas in African–American patients appear to be more aggressive than in Caucasian patients due to multifactorial differences.

METHODS

The authors compiled pathology data from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) database regarding stage, histologic grade, and estrogen receptor (ER) expression in breast carcinomas diagnosed in 197,274 African–American and Caucasian patients between 1990 and 2000, and the same information, along with nuclear grade, Ki‐67, c‐erb‐B2, and p53 expression, in 2230 African–American and Caucasian patients diagnosed at Thomas Jefferson University Hospital between 1995 and 2002. Immunohistochemical markers were assayed in paraffin‐embedded, formalin‐fixed tissue stained with hematoxylin and eosin using antibodies to these proteins, with differences in expression analyzed by the chisquare test.

RESULTS

In both databases, more African–American patients presented with advanced stage tumors and higher histologic (P < .001) and nuclear grade (P < .001) than Caucasian patients. African–American patients had less ER positivity (51.9% vs 63.1%; P < .001) but significantly higher Ki‐67 (42.4% vs 28.7%; P < .001) and p53 expression (19.4% vs 13.1%; P < .05) than Caucasian patients with all stages of disease. In addition, the basal or “triple‐negative” breast cancer phenotype was more common in African–American patients than in Caucasian patients (20.8% vs 10.4%; P < .0001), and was associated with higher histologic and nuclear grade (P < .0001).

CONCLUSIONS

African–American patients with breast carcinomas are more likely than Caucasian patients to present with tumors that are of a later stage and higher grade, with higher Ki‐67 expression and more ER negativity, thereby highlighting a greater need for early screening among African–American women. Molecular studies that may explain these differences, and correlations with survival, have been proposed to identify therapeutic targets. Cancer 2007. © 2007 American Cancer Society.
The risk of death from heart disease in patients with nonsmall cell lung cancer who receive postoperative radiotherapy
Authors: Lally Brian E. , Detterbeck Frank C. , Geiger Ann M. , Thomas Charles R. , Machtay Mitchell , Miller Antonius A. , Wilson Lynn D. , Oaks Timothy E. , Petty W. Jeffrey , Robbins Mike E. , Blackstock A. William
Published: July 2007

BACKGROUND.

This study was designed to investigate whether the mortality from heart disease, a manifestation of intercurrent disease after postoperative radiotherapy (PORT), has decreased over time for patients with nonsmall cell lung cancer (NSCLC).

METHODS.

The 17‐registry 1973 to 2003 dataset from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program was used to create a cohort of patients with NSCLC who had evidence of ipsilateral lymph node involvement diagnosed from 1983 to 1993 and who underwent pnuemonectomy/lobectomy (n = 6148 patients). Heart disease mortality was the primary endpoint: Deaths from other causes were censored, and surviving patients were censored at 10 years. The independent variable was PORT use, and adjustment variables included age at diagnosis, sex, race, year of diagnosis, laterality, location, histology, and the operation performed.

RESULTS.

Multivariate analysis revealed that PORT use was associated with an increase in heart disease mortality (hazards ratio [HR], 1.30; 95% confidence interval [95% CI], 1.04–1.61; P = .0193) along with older age, male sex, African‐American race, and earlier year of diagnosis. The association was confirmed in the cohort that was diagnosed from 1983 to 1988 (HR, 1.49; 95% CI, 1.11–2.01 [P = .0090]) but not for the cohort that was diagnosed from 1989 to 1993 (HR, 1.08; 95% CI, 0.79–1.48 [P = .6394]).

CONCLUSIONS.

The results from this study demonstrated that the risk of heart disease mortality associated with PORT has declined in more recent years. This may be secondary to improvements in the treatment planning and delivery of thoracic radiotherapy. Properly designed, prospective, adjuvant trials will be needed to verify these findings. Cancer 2007; 110:911–7. © 2007 American Cancer Society.
Diagnosis delays in childhood cancer
Authors: Dang‐Tan Tam , Franco Eduardo L.
Published: July 2007

Timely access to quality healthcare has become an increasingly important public health concern over the years. Early diagnosis of cancer is a fundamental goal in oncology because it allows an opportunity for timely treatment while disease burden is still in its earliest stages. Consequently, prognosis may improve, and a cure can be attained with minimal side or late effects. This review examined delays present in diagnosis of childhood cancers and factors that influence these delays. An extensive search of the literature published before April 15, 2007 was conducted for studies that evaluated any type of delay along the cancer‐care continuum. Twenty‐three studies were included. Diagnosis delay varied across studies. Physician delays were generally longer than those consequent to parents' or patients' recognition of underlying disease. Causes of delays can be grouped into 3 categories: patient and/or parent, disease, and healthcare. The main factors related to diagnosis delay were the child's age at diagnosis, parent level of education, type of cancer, presentation of symptoms, tumor site, cancer stage, and first medical specialty consulted. Greater understanding of factors that influence delays and the individual impact of patient and provider delays on disease severity and prognosis would be useful to form effective policies and programs aimed at ensuring timely access to healthcare for children with cancer. Cancer 2007. © 2007 American Cancer Society.
Digital video transmission for broadband networks
Authors: Hede Carsten
Published: July 2007

The information society to come is characterized by a large information flow in the integrated broadband network. Today it is the distribution of TV programmes that requires high transmission capacity. This leaves the cable operator with a problem. How should the CATV network of today be constructed? It must fulfil the need for distribution now and it must be prepared for new services to come.

Some aspects of the above problem are discussed in this paper. It is emphasized that digital techniques as well as optical fibre transmission should be included in a modern cable network. The Danish DOCAT network concept is presented as one way to accomplish this. DOCAT combines optical fibre transmission in the trunk network with conventional coaxial techniques in the subscriber network.
Optical cables, switches and logic (or madness)?
Authors: Midwinter J. E.
Published: July 2007

An invited contribution from a member of the editorial board, or another respected figure in the profession, in which a particular viewpoint is put forward giving an informed, but not necessarily conventional, opinion on a major topic in the field of communication systems.
High bandwidth metropolitan area networking architecture
Authors: Goldstein B. , Jaffe J. , Low J. , Meleis H.
Published: July 2007

The evolution of optical transmission media and laser technology has made bandwidth an abundant commodity rather than a scarce one. This factor has been clearly recognized by the communications community. As a result metropolitan area networks have been described by some as an extension of local area networks, with the major distinction being that MANs cover a larger distance than LANs. There are several limitations to the approach of simply extending LAN technology to the MAN environment. In this paper a new perspective on MAN architecture is provided that differs from the evolving LAN architecture.
Multiservice optical video communication networks — first results and ongoing developments in france
Authors: Triboulet M.
Published: July 2007

Since 1986, the first operating video communications systems developed by ALCATEL, have been commercially opened in the cities of Rennes, Saint‐Cloud, Mantes and Toulon; other plants are under installation in the cities of Evry, Marseille, Massy, Gennevilliers, Lille and Montpellier. The basic infrastructures already installed permit the connection of several tens of thousands of households.

Compared with conventional coaxial system, the ALCATEL video communications system presents the following main advantages:

More efficient operating facilities for audiovisual services offering built‐in access control functions, without any additional descrambling terminal on the user's premises, allowing easy introduction of pay‐per‐view programming, and providing advertising people with adequate audience measurements.

Flexible and continuous implementation of additional telecommunication services such as telephony, videotex, home security, bidirectional data transmission and professional specialized applications.

Those advantages are a direct consequence of the switched‐star network structure, based on fibre‐optic technologies.

After a brief overview of the architecture, the paper will present design principles and the main technical choices related to the ALCATEL system. The second part of the paper will describe the different subsystems constituting the switched‐star network such as the subscriber subsystem and the operating and maintenance organization. Lastly, different evolving schemes for future introduction of narrowband and the broadband telecommunication services will be proposed.
Efficient transport of narrowband and broadband information units in ATM networks
Authors: Pattavina Achille
Published: July 2007

The selection of appropriate information transfer units and their format is an important consideration in engineering a communication network based on the asynchronous transfer mode. This network, which basically consists of self‐routing switches and statistical multiplexers for fixed‐size information units, provides a slotted transport capability for narrowband and broadband services. It is difficult to choose a slot size to carry fixed‐size packets because it might not be optimal for all situations, given an uncertain mix of a variety of services each with different packet size requirements. Selection of a slot size is less critical when the protocol architecture contains a packet multiplexing protocol that allows several packets to be carried in the same slot. This paper describes this type of protocol. It also evaluates the performance of a concentrator for this protocol, providing an upper bound on the throughput and evaluating packet delays for different input levels. The results show that bandwidth can be used efficiently when information units smaller than the usable capacity of a slot are needed, e.g. short data transactions or voice packets.
A second‐generation BISDN prototype
Authors: Bussey Howard E. , Porter Frederick D. , Raitz John E.
Published: July 2007

High‐speed packet switching techniques enable broadband networks to efficiently transport and switch services of varied characteristics. Fixed‐length packets, or cells, are carried within a slotted frame structure. This form of transport is now known as asynchronous transfer mode (ATM). A broadband ATM‐based network can be described in terms of a small set of cell manipulation primitives. These primitives are described and partitioned into hardware modules. The modules may be interconnected in a variety of fashions for construction of broadband network prototypes. A configuration that implements broadband integrated access is described.
Elastic basket switching
Authors: Morita Shuzo , Katsuyama Tsuneo , Ito Kazuhiko , Hayami Hichiro
Published: July 2007

This paper proposes a new integrated switching system, ‘elastic basket switching’, for broadband and multimedia communications, including voice and high‐speed data.

In elastic basket switching (EBS), it is possible flexibly and efficiently to handle multimedia information by adaptively assigning communication resources according to communication requests and bandwidth of switched information. For continuous information, such as voice, EBS functions just as a circuit switching system, and for burst data it achieves high‐efficiency bandwidth usage equivalent to a packet switching system by demand‐assign type time‐slot assignment.

The detail of EBS and its application to a departmental system‐orientated PBX are described. The traffic handling capability and details of the hardware structure are presented. The experimental system, including use of LSIs in the main parts of EBS is also described.
Performance of wideband, non‐linearly amplified PAM cable systems
Authors: Hatzinakos Dimitrios , Feher Kamilo
Published: July 2007

The performance of wide‐band non‐linearly amplified, i.e. power efficient, 2‐, 4‐, 8‐, 16‐ and 32‐level PAM digital cable systems is studied. The effect of amplitude and phase non‐linearities (AM to AM) and (AM to PM) on the error rate performance and on the received eye diagrams is analysed by computer simulations and experimentally. We demonstrate that significant performance improvement could be attained by means of predistortion linearization, prior to the transmit (high power) amplifier, and by simple modification of the threshold decoding levels in the receiver.
Terminal‐to‐network communication in an ATM‐based ISDN
Authors: Pauwels B.
Published: July 2007

This paper addresses the topic of signalling and connectionless data transfer virtual channels in ATM at the UNI.

It recapitulates on the access signalling support in narrowband ISDN, as a representative of an STM network and the predecessor of the coming broadband ISDN. Also, the influence of the customer premises network architecture is taken into account.

From there, it is investigated in which ways these principles can be extended, into a general access infrastructure and access configuration management for signalling and connectionless services in the ATM‐based broadband ISDN. Some possible implications for the internal architecture of the CPN and the network are discussed. This brings some insight into the restrictions which standardization of these principles at the UNI may bring along for the architecture.
CATV in France: Present situation and future directions
Authors: Robin Philippe , Veyres Camille
Published: July 2007

Fibre‐optic systems have been introduced in France initially in the subscriber loop (fibre to the home) for experimenting switched broadband services (Biarritz opened in 1984) and then, under the Plan Cǎble for CATV/multiservice networks (twelve cities or groups of cities, about 900,000 homes), and as CATV trunks and feeders in 40 other cities or groups of cities (another 4,500,000 homes). This unique experience with fibre in the subscriber loop, albeit slightly premature gives some assurance on the future economic feasibility of the fibre‐to‐the‐home or fibre‐to‐the‐office concepts under development.

D2‐MAC/packet with smart card access control has been selected as the standard for scrambling/enciphering audiovisual signals on cable and on satellite.

The integration of the recent hybrid or fibre broadband TV networks and of their network management systems into the telecommunication networks is still being discussed.
Consortel: A CATV/TELCO solution, providing a fully digital fibre‐based broadband switched distribution network
Authors: Lacerte C. , Poirier J. P.
Published: July 2007

Telephone companies and cable operators have many needs in common. Both wish to increase revenues by adding new services. Both plan to convert to fibre optics in order to lower costs in installation, operations and maintenance. Each must provide basic services economically while replacing obsolete equipment and infrastructures.

Each year, network operators devote a large portion of their revenues to the provision and maintenance of network‐based services and equipment. Lately, activities such as installing equipment at a customer site and detecting and repairing network problems have become an area of concern as organizations strive to minimize technological impacts and achieve operations savings.

This paper is divided into three parts. First, the reader is provided with a description of the Consortel network architecture. This functional description is then completed by a description of the software applications that support network operations activities. Finally, economic considerations are examined in the implementation of this digital distribution network.
introduction and evolution of optical fibre systems in the local loop
Authors: Dyke Peter J.
Published: July 2007

Many administrations are actively considering the use of optical fibre systems in the local loop for connecting to end customers. These might initially carry a range of services to large businesses, followed later by telephony and/or cable TV services to residential subscribers. Finally, true broadband services will be required.

This paper briefly describes some technical options for introducing optical systems into the local loop. It indicates a scenario for cost‐effective introduction known as ‘fibre to the kerb’ while providing an infrastructure suitable for evolving into ‘fibre to the home’ and later carrying future broadband services.
Buffer sizing in an ATM switch for both ATM and STM traffics
Authors: Gravey Annie , Hebuterne Gérard , Boyer Pierre , Louvion Jean‐Raymond
Published: July 2007

Specific queueing models are derived in order to size the buffers of ATM switching elements in the cases of ATM or STM multiplexed traffic. Buffering is performed either at the outputs or in a central memory for ATM multiplexed traffic; for STM multiplexed traffic, buffers can also be provided at the inputs. The buffer size is chosen in order to ensure a loss probability in the switch smaller than 10−10.

It is shown that the buffer size per output in the case of central queueing is smaller than the buffer size in case of output queueing for both ATM and STM multiplexed traffics. Moreover, for STM multiplexed traffic, buffer sizes are identical for input and output queueing. Lastly, it is pointed out that buffers used for STM multiplexed traffic should be 4 to 20 times larger than the corresponding buffers for ATM multiplexed traffic.
An efficient contention resolution algorithm for input queuing atm cross‐connect switches
Authors: Obara Hitoshi , Yasushi Tetsujirou
Published: July 2007

This paper describes an efficient contention resolution algorithm and its distributed implementation for large capacity input queuing cross‐connect switches, which will establish virtual paths in future broadband ATM networks. The algorithm dynamically allocates sending time to cells held in input queues when no contention is indicated in the designated output ports. An expression for the mean delay and the cell loss probability for random traffic are derived through an approximate analysis. Input cells are served on a first‐come, first‐served basis as conventional contention resolution algorithms whose throughput saturates at 58 per cent because of head of line blocking in input queues. The proposed algorithm achieves a maximum throughput of 76 per cent.
Output‐buffer switch architecture for asynchronous transfer mode
Authors: Suzuki H. , Nagano H. , Suzuki T. , Takeuchi T. , Iwasaki S.
Published: July 2007

This paper proposes a new asynchronous transfer mode (ATM) switch architecture for the broadband ISDN. The ATOM switch ATM output‐buffer modular switch has a multi‐stage network structure, and is highly modular to facilitate capacity expansion. The ATOM switch element is of the output‐buffer type with a time‐division multiplexed bus and FIFO buffer for each outgoing line. Bit‐slice techniques are used to implement the high‐speed time‐division bus and buffer memories. The output buffer switch has the advantages of no throughput degradation since internal contention is eliminated, and a simple control structure for providing priority and multi‐point connections. This paper also deals with switching delay and buffer overflow probabilities for mixed (bursty and non‐bursty) traffic.
ARMORIQUE: A pure ATM versatile interconnection network
Authors: Dupuis Alain , Hebuterne Gérard , Quinquis Jean Paul , Lespagnol Albert
Published: July 2007

We present a proposal for a pure all‐ATM private network architecture able to be implemented on any physical wiring (star, ring or hierarchical network). The discussion is based upon an experimental network under study in CNET, named ARMORIQUE. Traffic estimations show that the solution proposed is able to fulfil severe grade of service requirements and offers sufficient throughput to the interconnected sources.