bluuebunny/crossref_metadata_2025 huggingface dataset:
Safety and Efficacy of a Steerable Temperature Monitoring Microwave Catheter System for Ventricular Myocardial Ablation
Authors: VANDERBRINK BRIAN A. , GILBRIDE CHARLES , ARONOVITZ MARK J. , LENIHAN TIM , SCHORN GREG , TAYLOR KEVIN , REGAN JAMES F. , CARR KENNETH , SCHOEN FREDERICK J. , LINK MARK S. , HOMOUD MUNTHER K. , ESTES N.A. MARK , WANG PAUL J.
Published: April 2007

Microwave Ablation of Canine Ventricle. Introduction: Radiofrequency current delivered during cardiac ablation is limited by a rise in impedance secondary to coagulum formation on the ablation electrode. Microwave antennas continue to deliver energy despite the presence of coagulum; thus, temperature control of the ablation electrode may be even more important for microwave than for radiofrequency ablations to avoid thromboembolic risks. The purpose of this study was to test the safety and efficacy of an ablation system utilizing a feedback control system to maintain a fixed target temperature for creating lesions with multiple applications of microwave energy.

Methods and Resutts: Microwave ablation was assessed using an 8.5‐French catheter at 2 to 4 sites in 11 dogs. Microwave energy delivery was performed for 60 seconds three times at the same site. Power was regulated using a feedback control mechanism to maintain a target temperature of 75°C. Ambulatory ECG monitoring was performed before and after ablation to assess arrhythmia occurrence. After follow‐up, the dogs were euthanized, and lesion dimensions measured after fixation. The mean power appllied to achieve the target temperature of 75°C was 9.3 ± 44 W. The mean depth of the lesions was 8.8 ± 4.2 mm. Tbe mean volume of the lesions was 304 ± 240 mm3. Forty‐four percent of the lesions were transmural. No endocardial thrombus was found. Ventricular tachycardia was observed acutely but resolved after 1 week.

Conclusion: Temperature feedback control systems for microwave ablation using a temperature‐controlled system is feasible for myocardial ablation and creates uniform and large lesions; however, such large lesions can be acutely proarrbythmic.
Factors Determining Clockwise and Connterclockwise Conduction Patterns in Atrial Reentrant Tachycardias
Authors: SHOJI SATOSHI , ADANIYA HITOSHI , NUMANO FUJIO , HIRAOKA MASAYASU
Published: April 2007

Clockwise and Counterclockwise Rotation in AFL Model. Introdaction: In the development of atrial flutter due to reentry, the crista terminalis is supposed to pose a conduction barrier, but the role of its longitudinal conduction in determining the propagation pattern of the reentrant impulse is not known. In rahbit right atrial preparations, we induced reentrant atrial tachycardias and examined the effects of transverse section of the crista terminalis on the development and conduction patterns of arrhythmias.

Methods and Results: Right atrial preparations from 12 albino rahbits were placed endocardial surface down in a chamber with an array of 48 bipolar electrodes to draw activation maps. A single premature stimulus was delivered to induce tachycardias at the free wall. In the control, five instances of tachycardia per preparation were induced and another five were induced after cutting the crista terminalis. In the control, the mean duration of tachycardia was 127.1 ± 25.2 seconds. The tachycardia was counterclockwise in 39 of 60 instances, clockwise in 12, and undetermined in 4 defined as “atypical.” After transverse section of the crista terminalis, the duration was prolonged to 372.6 ± 30.4 seconds, but the conduction patterns were not changed. In the free wall, counterclockwise reentry had a broader wavefront and faster conduction than clockwise reentry.

Conclusion: Longitudinal conduction block at the crista terminalis contributed to maintenance of reentrant atrial tachycardias, but had no influence on their propagation patterns. Clockwise and counterclockwise rotation of impulses in reentrant tachycardias bad different paths and velocities of the wavefront in the free wall of the right atrium.
Temperature‐Sensitive Focal Atrial Tachycardia in the Left Atrium
Authors: NG G. ANDRÉ , LAU ERNEST W. , GRIFFITH MICHAEL J.
Published: April 2007

Temperature‐Sensitive Focal Atrial Tachycardia. Temperature sensitivity has not been reported in focal atrial tachycardia. We describe a patient with a left atrial tachycardia whose tachycardia rate was affected by hot and cold drinks. The elTects were still evident after autonomic blockade. The arrhythmia focus was located at the entrance of the left upper pulmonary vein. Radiofrequency ablation was carried out, which proved to be difficult, but it was successful after several applications of energy, suggesting an epicardial location of the arrhytbmia focus. Sensitivity of atrial tachycardia rate to the temperature of food or drink ingested suggests a left atrial focus with a posterior and possibly epicardial location.
First Evidence of Premature Ventricular Complex‐Induced Cardiomyopathy: A Potentially Reversible Cause of Heart Failure
Authors: CHUGH SUMEET S. , SHEN WIN‐K. , LURIA DAVID M. , SMITH HUGH C.
Published: April 2007

PVC‐Induced Cardiomyopathy. Tachycardia‐induced cardiomyopathy is a well‐recognized and reversible condition, but left ventricular dysfunction due to frequent isolated premature ventricular complexes (PVCs) has not been reported. We observed resolution of dilated cardiomyopathy in a patient after a focal source of PVCs was eliminated by radiofrequency ablation. In a subset of patients with heart failure, PVC‐induced cardiomyopathy may be a potentially reversible cause of left ventricular dysfunction.
Right Pulmonary Vein Potentials Recorded from the Posterior Right Atrial Endocardium: Human Case Report and Validation in a Porcine Model
Authors: SCHWARTZMAN DAVID
Published: April 2007

Pulmonary Vein Potentials in Right Atrium. A 33‐year‐old woman underwent successful catheter ablation of an atrial tachycardia emanating from deep within a large right superior pulmonary vein (RSPV). A previous ablation attempt in this patient had failed, during which radiofrequency energy applications were made to the posterior right atrium only. The mistaken impression of a right atrial source for this tachycardia was due to RSPV potentials that were recorded during mapping in a region of the posterior right atrium contiguous to the vein (“contiguity region”). To further evaluate this, we performed activation mapping and radiofrequency ahlation in atria of healthy pigs. Similar to the reported case, “biatrial” potentials were recorded from both left and right aspects of the contiguity region. Radiofrequency energy application altered only the potential emanating from the atrium in which the lesion was applied. Histologic analysis confirmed that the lesion was limited to this atrium. It is concluded that, due to their proximity, electrical activity in the RSPV may be recorded from certain areas of the posterior right atrium, and vice versa. In the reported case of left atrial tachycardia, this led to the mistaken impression of right atrial tachycardia.
Electrophysiologic Characteristics and Ablation of an Atypical Atrial Flutter in the Right Atrium
Authors: CHANG KUAN‐CHENG , LIN YU‐CHIN , CHOU HSIANG‐TAI , HUNG JUI‐SUNG
Published: April 2007

Ablation of Atypical Atrial Flutter. Subeustachian isthmus‐dependent typical atrial flutter has been well studied. We demonstrate a case with atypical atrial fiutter involving only the base of the right atrium around the inferior vena cava. Entrainment pacing and mapping studies documented a distinct circuit traversing the subeustachian isthmus, propagating through the posterobasal right atrium, and skirting the inferior vena cava. Successful radiofrequency ablation of the arrhythmia was accomplished by creating a linear lesion at the subeustachian isthmus. Mapping of the inferior vena cava region and the demonstration of concealed entrainment are essential steps in establishing the mechanism of the atypical atrial flutter.
Virtual Electrodes and Deexcitation: New Insights into Fibrillation Induction and Defibrillation
Authors: EFIMOV IGOR R. , GRAY RICHARD A. , ROTH BRADLEY J.
Published: April 2007

Deexcitation During Fibrillation Induction and Defibrillation. Previous models of fibrillation induction and defibrillation stressed the contribution of depolarization during the response of the heart to a shock. This article reviews recent evidence suggesting that comprehending the role of negative polarization (hyperpolarization) also is crucial for understanding the response to a shock. Negative polarization can “deexcite” cardiac cells, creating regions of excitable tissue through which wavefronts can propagate. These wavefronts can result in new reentrant circuits, inducing fibrillation or causing defibrillation to fail. In addition, deexcitation can lead to rapid propagation through newly excitable regions, resulting in the elimination of excitable gaps soon after the shock and causing defibrillation to succeed.
Cardiac Electrophysiology in Genetically Engineered Mice
Authors: GEHRMANN JOSEF , BERUL CHARLES I.
Published: April 2007

Mouse Electrophysiology. The mouse has become the principal animal model for studying biologic processes in mammals. Major advances in transgene and gene targeting technology enabled manipulation of the mouse genome in a predictable fashion. Mutant mouse strains provide important insights into the molecular mechanisms underlying normal and disordered cardiac conduction and sudden cardiac death. A variety of mouse strains harboring gene mutations leading to inherited developmental disorders have been designed. Structural protein abnormalities, connexin protein defects, and ion channelopathies associated with human clinical phenotypes, including congenital heart disease, cardiomyopathies, long QT syndrome, and muscular dystrophy, have been engineered into the mouse genome, creating models of human electrophysiologic disease. Functional analyses of the underlying molecular mechanisms of resultant phenotypes require appropriate and sophisticated experimental methodology. In this review, genetic mouse models pertinent to human arrhythmogenic disorders and their application to present‐day ex vivo and in vivo murine electrophysiologic technology at the whole organ and animal levels are discussed.
Lithium increases PGC‐1α expression and mitochondrial biogenesis in primary bovine aortic endothelial cells
Authors: Struewing Ian T. , Barnett Corey D. , Tang Tao , Mao Catherine D.
Published: April 2007

Lithium is a therapeutic agent commonly used to treat bipolar disorder and its beneficial effects are thought to be due to a combination of activation of the Wnt/β‐catenin pathway via inhibition of glycogen synthase kinase‐3β and depletion of the inositol pool via inhibition of the inositol monophosphatase‐1. We demonstrated that lithium in primary endothelial cells induced an increase in mitochondrial mass leading to an increase in ATP production without any significant change in mitochondrial efficiency. This increase in mitochondrial mass was associated with an increase in the mRNA levels of mitochondrial biogenesis transcription factors: nuclear respiratory factor‐1 and ‐2β, as well as mitochondrial transcription factors A and B2, which lead to the coordinated upregulation of oxidative phosphorylation components encoded by either the nuclear or mitochondrial genome. These effects of lithium on mitochondrial biogenesis were independent of the inhibition of glycogen synthase kinase‐3β and independent of inositol depletion. Also, expression of the coactivator PGC‐1α was increased, whereas expression of the coactivator PRC was not affected. Lithium treatment rapidly induced a decrease in activating Akt‐Ser473 phosphorylation and inhibitory Forkhead box class O (FOXO1)‐Thr24 phosphorylation, as well as an increase in activating c‐AMP responsive element binding (CREB)‐Ser133 phosphorylation, two mechanisms known to control PGC‐1α expression. Together, our results show that lithium induces mitochondrial biogenesis via CREB/PGC‐1α and FOXO1/PGC‐1α cascades, which highlight the pleiotropic effects of lithium and reveal also novel beneficial effects via preservation of mitochondrial functions.
Peroxin Pex21p interacts with the C‐terminal noncatalytic domain of yeast seryl‐tRNA synthetase and forms a specific ternary complex with tRNASer
Authors: Godinic Vlatka , Mocibob Marko , Rocak Sanda , Ibba Michael , Weygand‐Durasevic Ivana
Published: April 2007

The seryl‐tRNA synthetase from Saccharomyces cerevisiae interacts with the peroxisome biogenesis‐related factor Pex21p. Several deletion mutants of seryl‐tRNA synthetase were constructed and inspected for their ability to interact with Pex21p in a yeast two‐hybrid assay, allowing mapping of the synthetase domain required for complex assembly. Deletion of the 13 C‐terminal amino acids abolished Pex21p binding to seryl‐tRNA synthetase. The catalytic parameters of purified truncated seryl‐tRNA synthetase, determined in the serylation reaction, were found to be almost identical to those of the native enzyme. In vivo loss of interaction with Pex21p was confirmed in vitro by coaffinity purification. These data indicate that the C‐terminally appended domain of yeast seryl‐tRNA synthetase does not participate in substrate binding, but instead is required for association with Pex21p. We further determined that Pex21p does not directly bind tRNA, and nor does it possess a tRNA‐binding motif, but it instead participates in the formation of a specific ternary complex with seryl‐tRNA synthetase and tRNASer, strengthening the interaction of seryl‐tRNA synthetase with its cognate tRNASer.
Nocturnal swimming, aggregation at light traps, and mass spawning of scissurellid gastropods (Mollusca: Vetigastropoda)
Authors: Hickman Carole S. , Porter Stephanie S.
Published: April 2007

Abstract. Thousands of minute scissurellid gastropods (Vetigastropoda: Scissurellidae) were observed and collected at floating light traps in Moorea, French Polynesia, where a mass spawning event occurred on November 11, 2002. More than 20,000 live snails were recovered from the traps, and epidemic spawning continued in the laboratory, where clouds of white sperm and red‐orange eggs were broadcast into the water. No aggregations of this magnitude have been reported previously in vetigastropods, nor is the capacity for sustained swimming known from other vetigastropod taxa. Snails had emerged from a local benthic habitat of coral sand and swum through ≥2 m of water to reach the traps. Scanning electron micrographs of the ornate shells confirm the identity of the most abundant species as Scissurella spinosa, with lesser numbers of Sinezona plicata. Our observations indicate that scissurellids are not exclusively benthic and that they are not rare, even though they have seldom been collected and studied alive. Because little is known about the basic biology and anatomy of scissurellids and because their position within the basal Gastropoda is poorly resolved, we include information on the design and construction of inexpensive light traps to promote comparative investigation of other poorly known species.
Developmental pattern of telomerase expression in the sand scallop, Euvola ziczac
Authors: Owen Richard , Sarkis Samia , Bodnar Andrea
Published: April 2007

Abstract. Telomerase is a ribonucleoprotein that can maintain telomeres, the repetitive sequences of DNA found at the end of eukaryotic chromosomes, and confer long‐term proliferative capacity on cells. Telomerase expression is essential during periods of intense cell division such as the early developmental process. In later development, some species retain telomerase activity while others repress telomerase activity in what is thought to be a tumor‐protective mechanism. Despite the importance of telomerase expression in both development and neoplastic disease, no studies to date have characterized its expression in bivalves. We present the first report of telomerase expression in a bivalve species, the sand scallop, Euvola ziczac. Telomerase activity was detected throughout the early stages of development and in all adult tissues examined. Analysis of DNA isolated from adult tissues indicated long telomeres, with terminal restriction fragment lengths >20 kb in both somatic and germ tissues. Ubiquitous telomerase expression throughout development and into adulthood would suggest a lack of telomere‐related senescence and suggests that these scallops do not use telomerase repression as a mechanism to suppress the formation of neoplasm.
Predator–prey interactions between crayfish (Orconectes juvenilis) and snails (Physa gyrina) are affected by spatial scale and chemical cues
Authors: Dickey Bradley F. , McCarthy Thomas M.
Published: April 2007

Abstract. We conducted two experiments to compare the behaviors of predatory crayfish (Orconectes juvenilis) and snail prey (Physa gyrina), with and without exposure to injured‐snail cues, in seven different sizes of arena. Individuals in both O. juvenilis and P. gyrina are known to obtain information about predation events from chemical cues present in the water, but the effect of spatial scale on this information or the ensuing interaction has not been previously investigated. We found that crayfish were generally more active in larger arenas, but their response to injured‐snail cues decreased as arena size increased. Snails responded to injured‐snail cue by seeking refuge, but responded less strongly in larger arenas. Less time was required for crayfish to capture a snail in the presence of injured‐snail cue, and there was an interaction between cue and arena size evident in middle‐sized arenas. Consumption time was lower in the presence of injured‐snail cue but was unaffected by arena size. Based on these results, we conclude that the effects of injured‐snail cue are mediated by spatial scale, and this affects the outcome of this predator–prey interaction. Spatial scale should be considered in the design and interpretation of other predator–prey studies, particularly when sensory or motility differences exist between predators and prey that affect how each gathers information about the environment.
Heterozygosity and fitness in a California population of the labyrinth spider Metepeira ventura (Araneae, Araneidae)
Authors: Ramirez Martin G. , Eiman Sarah S. , Wetkowski Melissa M. , Mooers Miranda K. , Alvarez Michelle H. , Mitchell Kathleen G. , Ocampo Luningning A. , Olvera Sylvia V. , McGran Allison S.
Published: April 2007

Abstract. The relationship between individual heterozygosity and characteristics likely to be associated with fitness was investigated in the labyrinth spider Metepeira ventura. Adult females and their egg sacs were collected at a coastal site in southern California, and three measures of bodily condition (carapace width, weight, residual index) and six measures of reproductive output (number of egg sacs, variation in egg number among sacs [coefficient of variation], total number of eggs, mean eggs/sac, mean eggs/sac divided by carapace width, mean eggs/sac divided by weight) were determined for each spider. The sample was polymorphic at three allozyme loci that were in Hardy–Weinberg equilibrium, and individual females were heterozygous at up to two of the three loci, forming three heterozygosity classes (0, 1, and 2). None of the bodily condition measures were significantly related to the number of heterozygous loci, while four of the reproductive output estimators (total number of eggs, mean eggs/sac, mean eggs/sac divided by carapace width, mean eggs/sac divided by weight) were significantly influenced by heterozygosity. In each significant case, values for class 2 females were less than those for class 0 and 1 females, whose values were usually more similar. Thus, while female bodily condition was comparable among classes, the most heterozygous females produced fewer total eggs and eggs per sac than their less heterozygous peers. The fact that females of M. ventura engage in a reproductive investment‐number trade‐off suggests that high‐variability and low‐variability females may be pursuing distinct reproductive strategies in the wild, with more heterozygous females being K‐selected (smaller clutches, heavier eggs) and more homozygous females being r‐selected (larger clutches, lighter eggs). Further investigation will be needed to assess more fully the fitness value of heterozygosity in M. ventura.
REPLICATED SIMILARITY TESTING USING PAIRED COMPARISON METHOD
Authors: BI JIAN
Published: April 2007

The present article discusses the replicated similarity testing using a paired comparison method. The “two one‐sided tests” (TOST) combined with a beta‐binomial model are proposed for this testing. Simulation studies provide evidence that the proposed testing is valid and reliable.
ON WARM‐UP
Authors: MATA‐GARCIA MOISES , ANGULO OFELIA , O'MAHONY MICHAEL
Published: April 2007

This article discusses the background, mechanism and need for warm‐up before performing difference tests while aspects of the methodology are illustrated with examples.
MODELING THE EVOLUTION OF THE PERFORMANCE OF A SENSORY PANEL: A MIXED‐MODEL AND CONTROL CHART APPROACH
Authors: PINEAU NICOLAS , CHABANET CLAIRE , SCHLICH PASCAL
Published: April 2007

A sensory panel is often used to profile the same type of product with the same set of attributes for many years. We are interested in characterizing the evolution of the performance of such a panel (and its panelists) over time. This article presents a methodology based on a mixed‐model approach that takes into account the evolution of both panel and panelist in the same model. At the panel level, linear and quadratic evolutions of the performance are tested. At the panelist level, the method allows detection of whether some panelists perform better than others, and whether this difference remains the same or evolves over time. This mixed‐model approach is followed by a graphical representation using a control chart method to identify occasional outliers. Data used to illustrate this methodology are eight sensory profiling data sets collected on ready‐made frozen meals between 1997 and 2001 (every 6 months). The performance index chosen as an example in this study is the individual repeatability measured by standard deviation over replicates.
A Social Network Analysis of the Journal of Supply Chain Management: Knowledge Generation, Knowledge Diffusion and Thought Leadership
Authors: Carter Craig R. , Leuschner Rudolf , Rogers Dale S.
Published: April 2007

The authors conduct a citation analysis of the Journal of Supply Chain Management over its first 40 years of publication, with the objectives of better understanding the sources that supply management scholars have drawn upon to generate research appearing in the Journal. Social network analysis is introduced and used to better understand how research that has been published in the Journal has been diffused across universities, and to identify university thought leaders. The authors provide future research directions based on additional, potential applications of social network analysis.
The PMI, the T‐Bill and Inventories: A Comparative Analysis of Neural Network and Regression Forecasts
Authors: Larrain Maurice
Published: April 2007

The PMI is widely used as an indicator of economic trends, and as a short‐term forecaster of several important lagging output variables. The PMI's importance has led to several attempts at forecasting its direction. This research builds on this foundation by attempting to forecast the PMI through the use of regression and neural network methodology. Findings indicate that short‐term interest rates lead and forecast changes in the PMI by 10 months. Additionally, the paper focuses on the PMI as a predictor. Of the many variables the PMI can fit or predict, results reveal inventories as the most relevant example for supply chain managers, showing the PMI is a predictor of real inventory changes 8 months out.
Noise and Hearing Loss: A Review
Authors: Daniel Eileen
Published: April 2007

Background:  Noise‐induced hearing loss is a major cause of deafness and hearing impairment in the United States. Though genetics and advanced age are major risk factors, temporary and permanent hearing impairments are becoming more common among young adults and children especially with the increased exposure to portable music players. Though treatment options are limited for most people with noise‐related hearing loss, several modifiable health behaviors that should begin in childhood might prevent or delay the onset of hearing impairment. The purpose of this article is to review modifiable and nonmodifiable risk factors, comorbidity, and the role of health education in the prevention of noise‐induced hearing loss.

Methods:  Review of current literature in the etiology, prevention, and treatment of noise‐induced hearing loss as well as the role of health education.

Results:  Nonmodifiable risk factors related to noise‐related hearing loss include increasing age, genetics, male gender, and race. Modifiable risk factors are voluntary exposure to loud noise, nonuse of hearing protection, smoking, lack of exercise, poor diet, tooth loss, and the presence of diabetes and cardiovascular disease.

Conclusions:  As hearing impairment among children and teenagers rises due to mostly voluntary exposure to loud noise, there are many implications for health education. Health educators need to address barriers to the use of hearing protection, deliberate exposure to loud music, and other modifiable risk factors, which cause and exacerbate hearing loss among those exposed to loud noise.
Association of Relative Backpack Weight With Reported Pain, Pain Sites, Medical Utilization, and Lost School Time in Children and Adolescents
Authors: Moore Michael J. , White Gregory L. , Moore Donna L.
Published: April 2007

Background: There is debate about a 10% versus 15% of body weight cutoff point for safe weight of school backpacks. Estimation of the cutoff may be affected by use of survey methods and failure to assess pain experienced while wearing a backpack. Previous research also suggests that younger students and females are more at risk for developing backpack pain.

Methods: Five hundred and thirty‐one 5th‐ to 12th‐grade Northern California students and their backpacks were weighed. Students were individually interviewed about how often they experienced pain while carrying a backpack, the site of their pain, and if the pain had interfered with school activities or led to medical care.

Results: Data support the use of a 10% of body weight cutoff for safe use of backpacks for all grade levels. Younger students and females are more at risk due to relatively lower body weight while females also carry heavier backpacks than males. Greater relative backpack weight is associated with upper– and mid–back pain reports but not neck or lower back pain; it is also associated with lost school time, lost school sports time, and greater chiropractic utilization.

Conclusions: The 10% cutoff is recommended along with a variety of practical methods to help schools achieve that goal for middle and high school students.
Primary Grade Teachers’ Perceptions and Practices Regarding Pedestrian Safety Education
Authors: Lartey Grace K. , Price James H. , Telljohann Susan K. , Dake Joseph A. , Yingling Faith
Published: April 2007

Background:  Pedestrian injury is the third leading cause of unintentional injury and death among children 1‐14 years old. The purpose of this study was to examine primary grade teachers’ perceived role in pedestrian safety education.

Methods:  A total of 630 surveys were sent to a national random sample of primary school teachers and 54% responded.

Results:  The results of the study found that 85% of primary grade teachers believed it was extremely important or important to teach pedestrian safety. Forty percent of the teachers identified that they had been teaching pedestrian safety for more than 1 year (maintenance stage), whereas 1 in 3 teachers had never thought about (precontemplation stage) teaching pedestrian safety to their students. Eighty‐eight percent of primary grade teachers were very confident about teaching students how to safely cross the street, where to safely cross the street (87%), when to safely cross the street (86%), and how to safely walk along streets with sidewalks (83%). An examination of how pedestrian safety information was presented found that a plurality (39%) of the teachers who taught pedestrian safety presented information through classroom discussion. Also, 46% of the teachers who taught pedestrian safety identified the following as the most common curriculum content: when to safely cross the street (46%), how to safely cross the street (45%), and where to safely cross the street (43%).

Conclusions:  Only 16% of primary school teachers reported pedestrian safety education was required for their grade levels. Yet, pedestrian safety education decreases pedestrian‐related deaths. Therefore, it is important for schools and primary grade teachers to expose their students to this essential topic.
THE WORM THAT FLIES IN THE NIGHT1
Authors: Williams Paul
Published: April 2007

abstract  The author reflects upon the nature and process of generating original thought using examples from psychoanalysis, anthropology, poetry, art and ordinary life. The capacity to remain open to preconscious and unconscious influences, and to be able to mentally represent these, is deemed essential for the generation of thought, as opposed to reflexive thinking and mimesis. The conditions for this generative, dialectical mental activity are considered. Through a clinical example of a psychoanalytic treatment of a highly disturbed young man, processes of destruction of generative thought by psychosis are discussed, and what is required for this destructive activity to be halted and reversed. Paramount amongst the analyst’s forms of engagement with the patient is the employment of intuition as a means of identifying unconscious truths and of creating the conditions for a ‘third’ analytic position without which the growth of mind is not possible.
BI‐LOGIC AS A BRIDGE BETWEEN PSYCHOANALYSIS AND CBT AND AS A THEORETICAL RATIONALE FOR BECK’S COGNITIVE DISTORTIONS
Authors: Sacks Maxine
Published: April 2007

abstract  This paper examines ways in which Matte Blanco’s ideas can be used to link psychodynamic and cognitive behavioural theories. The two approaches have developed independently but integrative thinking is becoming increasingly important. Psychodynamic concepts are used in some cognitive approaches and unconscious processes are a focus for academic psychology and neuroscience. Matte Blanco provides us with an alternative logic for the unconscious which can be used to develop the cognitive behavioural approach and provide links with understanding from the analytic tradition.
PATHOLOGICAL ORGANIZATIONS OF THE PERSONALITY: A CLINICAL CASE STUDY
Authors: Chiesa Marco
Published: April 2007

abstract  In this paper the author describes the features and clinical manifestations of specific states of mind, which functioned as psychic retreats in a male homosexual patient. Two main types of retreats emerged in the course of the analysis. The first took the shape of an inanimate object (a spaceship), within which little human contact was allowed to exist. In the second retreat some degree of relating was present, but that mental space was populated with threatening homosexual figures which kept a strong hold on the patient’s ego and attacked any meaningful contact established between patient and analyst. The presence of these structures enabled the patient to evade awareness of the injured, paralysed and damaged state in which his internal objects were kept, and to bypass depressive anxieties connected to painful early oedipal conflicts, which included a terrifying maternal introject. The attempt to recruit the analysis into the patient’s psychic retreat constituted a central transference manifestation.
SHARING A HEART: THE DILEMMA OF A FUSED COUPLE
Authors: Rosenthall Joanna
Published: April 2007

abstract  In this paper the writer explores the work with a couple whom she came to think of psychically like Siamese twins, stuck together in order to survive and lacking separate psychic entities with intact coverings. Such a covering is something that we take for granted and which implies that each of us is a separate individual. However, this paper draws attention to the way that some individuals, who have not developed a robust enough sense of identity, might seek a desperate solution, by partnering with someone who shares their dilemma. Being ‘stuck’ together can help stave off intolerable anxieties but tends to raise claustrophobic anxieties. The paper investigates how the underlying anxieties are primitive and serious, and the terrors which are being defended against are often in the area of suicide or breakdown so that, although couple therapy can help to loosen this deadly structure, a more containing intensive individual treatment is likely to be necessary to support the process of individuation.
Modulation of multisegmental monosynaptic responses in a variety of leg muscles during walking and running in humans
Authors: Courtine Grégoire , Harkema Susan J. , Dy Christine J. , Gerasimenko Yuri P. , Dyhre‐Poulsen Poul
Published: April 2007

Motor responses evoked by stimulating the spinal cord percutaneously between the T11 and T12 spinous processes were studied in eight human subjects during walking and running. Stimulation elicited responses bilaterally in the biceps femoris, vastus lateralis, rectus femoris, medial gastrocnemius, soleus, tibialis anterior, extensor digitorum brevis and flexor digitorum brevis. The evoked responses were consistent with activation of Ia afferent fibres through monosynaptic neural circuits since they were inhibited when a prior stimulus was given and during tendon vibration. Furthermore, the soleus motor responses were inhibited during the swing phase of walking as observed for the soleus H‐reflex elicited by tibial nerve stimulation. Due to the anatomical site and the fibre composition of the peripheral nerves it is difficult to elicit H‐reflex in leg muscles other than the soleus, especially during movement. In turn, the multisegmental monosynaptic responses (MMR) technique provides the opportunity to study modulation of monosynaptic reflexes for multiple muscles simultaneously. Phase‐dependent modulation of the MMR amplitude throughout the duration of the gait cycle period was observed in all muscles studied. The MMR amplitude was large when the muscle was activated whereas it was generally reduced, or even suppressed, when the muscle was quiescent. However, during running, there was a systematic anticipatory increase in the amplitude of the MMR at the end of swing in all proximal and distal extensor muscles. The present findings therefore suggest that there is a general control scheme by which the transmission in the monosynaptic neural circuits is modulated in all leg muscles during stepping so as to meet the requirement of the motor task.
NMDA receptors in preBötzinger complex neurons can drive respiratory rhythm independent of AMPA receptors
Authors: Morgado‐Valle Consuelo , Feldman Jack L.
Published: April 2007

The role of AMPA receptors (AMPARs) in generation and propagation of respiratory rhythm is well documented both in vivo and in vitro, whereas the functional significance of NMDA receptors (NMDARs) in preBötzinger complex (preBötC) neurons has not been explored. Here we examined the interactions between AMPARs and NMDARs during spontaneous respiratory rhythm generation in slices from neonatal rats in vitro. We tested the hypothesis that activation of NMDARs can drive respiratory rhythm in the absence of other excitatory drives. Blockade of NMDARs with dizocilpine hydrogen maleate (MK‐801, 20 μm) had a negligible effect on respiratory rhythm and pattern under standard conditions in vitro, whereas blockade of AMPARs with NBQX (0.5 μm) completely abolished respiratory activity. Removal of extracellular Mg2+ to relieve the voltage‐dependent block of NMDARs maintained respiratory rhythm without a significant effect on period, even in the presence of high NBQX concentrations (≤ 100 μm). Removal of Mg2+ increased inspiratory‐modulated inward current peak (II) and charge (QI) in preBötC neurons voltage‐clamped at −60 mV by 245% and 309%, respectively, with respect to basal values. We conclude that the normal AMPAR‐mediated postsynaptic current underlying respiratory drive can be replaced by NMDAR‐mediated postsynaptic current when the voltage‐dependent Mg2+ block is removed. Under this condition, respiratory‐related frequency is unaffected by changes in II, suggesting that the two can be independently regulated.
Control of basal extracellular adenosine concentration in rat cerebellum
Authors: Wall Mark J. , Atterbury Alison , Dale Nicholas
Published: April 2007

To re‐examine how the basal extracellular concentration of adenosine is regulated in acutely isolated cerebellar slices we have combined electrophysiological and microelectrode biosensor measurements. In almost all cases, synaptic transmission was tonically inhibited by adenosine acting via A1receptors. By contrast, in most slices, the biosensors did not measure an adenosine tone but did record a spatially non‐uniform extracellular tone of the downstream metabolites (inosine and hypoxanthine). Most of the extracellular hypoxanthine arose from the metabolism of inosine by ecto‐purine nucleoside phosphorylase (PNP). Adenosine kinase was the major determinant of adenosine levels, as its inhibition increased both adenosine concentration and A1receptor‐mediated synaptic inhibition. Breakdown of adenosine by adenosine deaminase was the major source of the inosine/hypoxanthine tone. However adenosine deaminase played a minor role in determining the level of adenosine at synapses, suggesting a distal location. Blockade of adenosine transport (by NBTI/dipyridamole) had inconsistent effects on basal levels of adenosine and synaptic transmission. Unexpectedly, application of NBTI/dipyridamole prevented the efflux of adenosine resulting from block of adenosine kinase at only a subset of synapses. We conclude that there is spatial variation in the functional expression of NBTI/dipyridamole‐sensitive transporters. The increased spatial and temporal resolution of the purine biosensor measurements has revealed the complexity of the control of adenosine and purine tone in the cerebellum.
The effects of repeated exposure to hypercapnia on arousal and cardiorespiratory responses during sleep in lambs
Authors: Johnston Renea V. , Grant Daniel A. , Wilkinson Malcolm H. , Walker Adrian M.
Published: April 2007

Arousal and cardio‐respiratory responses to respiratory stimuli during sleep are important protective mechanisms that rapidly become depressed in the active sleep state when episodes of hypoxia or asphyxia are repeated: whether responses to repeated hypercapnia are similarly depressed is not known. This study aimed to determine if arousal and cardio‐respiratory responses also become depressed with repeated episodes of hypercapnia during sleep and whether responses differ in active sleep and quiet sleep. Eight newborn lambs were instrumented to record sleep state and cardio‐respiratory variables. Lambs were subjected to two successive 12 h sleep recordings, assigned as either sequential control and test days, or test and control days performed between 12.00 and 00.00 h. The control day was a baseline study in which the lambs breathed air to determine spontaneous arousal probability. During the test day, lambs were exposed to a 60 s episode of normoxic hypercapnia (Fractional inspired CO2(F)= 0.08 and Fractional inspired O2(F)= 0.21 in N2) during every quiet sleep and active sleep epoch. The probability of lambs arousing during the hypercapnic exposure exceeded the probability of spontaneous arousal during quiet sleep (58%versus 21%, χ2= 54.0, P < 0.001) and active sleep (39%versus 20%, χ2= 10.0, P < 0.01), though the response was less in active sleep. Exposure to hypercapnia also resulted in a significant increase in ventilation in quiet sleep (150 ± 22%) and active sleep (97 ± 23%, P < 0.05), though the increase was smaller in active sleep (P < 0.05). Small (< 5%) blood pressure increases and heart rate decreases were evident during hypercapnia in quiet sleep, but not in active sleep. Arousal and cardio‐respiratory responses persisted with repetition of the hypercapnic exposure. In summary, although arousal and cardio‐respiratory responses to hypercapnia are less in active sleep compared with quiet sleep, these protective responses are not diminished with repeated exposure to hypercapnia.
Optimization of Thermomechanical Loading by the Inverse Method
Authors: Bogard Virginie , Revel Philippe , Hetet Yannick
Published: April 2007

This study presents 2D experimental results and the numerical simulations of thermal loads in order to observe their influences on the life of mechanical systems. The experimental and thermal evolution was measured using several thermocouples and an infrared pyrometer. In fact, the thermal loading was determined by the resolution of an inverse process where the parameters of thermal laws were identified by minimizing the difference between the experimental results and the numerical simulations. After this optimization process, the mechanical modeling by the finite element method was carried out by applying the optimized thermal loading. The laws of elastoviscoplastic behavior are applied in the working temperature range of a continuous casting rollers tool. This modeling constitutes a technological means to choose a type of a coating material and its optimum thickness and to test different thermal loads in order to optimize the industrial process and to improve the tool’s life.
Optimization of Material Properties and Process Parameters for Tube Hydroforming of Aluminum Extrusions
Authors: Loukus Adam R. , Subhash Ghatu , Imaninejad Mehdi
Published: April 2007

Analysis of process optimization for hydroforming of central-bulge and T-branch from AA6063 tubes is conducted for W-temper and T4 heat-treated conditions. Systematic characterization of AA6063 mechanical properties as a function of aging time was also conducted. It was found that hydroforming in the W temper facilitates forming of a bigger T branch (due to available greater ductility), but limits the strength (hardness) of the final component compared to that formed in the T4 condition. By optimizing the material heat-treatment conditions and the process parameters during hydroforming, strains well in excess of the traditional forming limits can be achieved in the finished components. The relevant microstructural kinetics during hydroforming of the above two geometries in the two heat treated conditions and the associated strengthening mechanisms in aluminum alloys are discussed.
Low-Velocity Impact Response Characterization of a Hybrid Titanium Composite Laminate
Authors: Bernhardt S. , Ramulu M. , Kobayashi A. S.
Published: April 2007

The low-velocity impact response of a hybrid titanium composite laminate, known as TiGr, was compared to that of graphite/epoxy composite. The TiGr material comprised of two outer plies of titanium foil surrounding a composite core. The composite core was PIXA-M (a high temperature thermoplastic) reinforced by IM-6 graphite fibers and consolidated by an induction heating process. The impact response of TiGr was characterized by two modes of failure which differed by failure or nonfailure in tension of the bottom titanium ply. The ductility of titanium caused buckling by yielding whereas the brittle adjacent composite ply lead to fracture. The maximum failure force of the material correlated well with the previously reported static flexural data, and the material outperformed the commonly used graphite/epoxy.
Fracture Characterization of Woven Fabric Reinforced Thermoplastic Composites
Authors: Zenasni R. , Bachir A. S. , Argüelles A. , Castrillo M. A. , Viña J.
Published: April 2007

The present paper deals with the strain energy release rate of three woven fabric reinforced thermoplastic composites. The interlaminar fracture behavior was studied using the mode I, double cantilever beam test and the mode II, end notched flexure test, in order to determine the energy required for the initiation and growth of an artificial crack. The materials used were made of two types of glass fiber weave (2∕2 Twill, 8H Satin) and a carbon fiber (8H Satin). The matrix was polyetherimide. The delamination energy of these two materials was compared in order to study the effect of weave and reinforcement on mechanical properties. The fracture mechanism was also analyzed by means of scanning electron microscopy.
Microwave Synthesis and Characterization of Magnesium Based Composites Containing Nanosized SiC and Hybrid (SiC+Al2O3) Reinforcements
Authors: Thakur Sanjay Kumar , Balasubramanian K. , Gupta Manoj
Published: April 2007

In the present study, monolithic magnesium, nanosized SiC reinforced magnesium and nanosized hybrid (SiC+Al2O3) reinforced magnesium materials have been synthesized by using powder metallurgy route involving microwave sintering followed by hot extrusion. The results show that the monolithic and the reinforced magnesium materials have minimal porosity and the reinforced magnesium materials have fairly well distributed nanosized SiC and SiC+Al2O3 particles in the matrix. The thermo-mechanical property measured in terms of coefficient of thermal expansion of the reinforced magnesium shows dimensionally more stable magnesium as compared to monolithic magnesium. The hardness 0.2% YS and UTS were found to improve significantly after addition of nanosized SiC and nanosized hybrid SiC+Al2O3 particles to the magnesium, However, ductility measured in terms of failure strain was found to be marginally reduced. Fractography results showed the presence of brittle failure mode with cleavage steps on the fractured surface of the magnesium matrix.
Residual Stress Solution Extrapolation for the Slitting Method Using Equilibrium Constraints
Authors: Schajer Gary S. , Prime Michael B.
Published: April 2007

Established methods for calculating residual stresses from the strains measured when using the slitting method give results for the stresses that exist within the depth range of the slit. Practical considerations typically limit this range to about 90–95% of the specimen thickness. Force and moment equilibrium can provide additional information that may be used to estimate the residual stresses in the “no-data” region within the remaining ligament beyond the maximum slit depth. Three different numerical methods to calculate the residual stress profile over the entire specimen thickness are investigated. They are truncated Legendre series, regularized Legendre series, and regularized unit pulses. In tests with simulated strain data and with strain data measured on a cold compressed 7050-T7452 Aluminum hand forging, the three methods gave generally similar stress results in the central region of the specimen. At small depths, where the strain sensitivity to the residual stresses is low, the two regularized calculation methods tended to give more stable results. In the area of very large depth beyond the maximum depth of the slit, the regularized Legendre series solution generally gave the most realistic stress results.