bluuebunny/crossref_metadata_2025 huggingface dataset:
a la la la archive
Authors: Juhasz Alexandra
Published: September 2011

In its time, at the Woman's Building, video played a central role in a unique feminist art education organized around the dangers of female representation and its associated pleasures of self-realization. Its collective video practices developed to acknowledge simultaneous points of view. Alexandra Juhasz revisits their archive of process with a different simultaneous look: hoping to see what other generations can learn from records of feminist and lesbian process.
Medium
Authors: Lord Catherine
Published: September 2011

A dedication is a speech act. Like saying, “I do thee wed,” to write, “I make you a gift of the words I have written” is to cause to be true the statement uttered, to tender oneself to another upon the material support that makes writing itself possible, and with it narrative, logic, and wonder. The dedications included in the series “Lecture” are gifts slipped between the title page and the frontispiece of books that trace what might be called queer culture.
Refining the high-dose streptozotocin-induced diabetic non-human primate model: an evaluation of risk factors and outcomes
Authors: Graham Melanie L , Mutch Lucas A , Rieke Eric F , Kittredge Jessica A , Faig Aaron W , DuFour Theresa A , Munson James W , Zolondek Elizabeth K , Hering Bernhard J , Schuurman Henk-Jan
Published: September 2011

In preparation for islet transplantation, diabetes was induced using streptozotocin (STZ) in non-human primates ranging from juveniles to adults with diverse body types: we studied the process with respect to the diabetic state and emergence of adverse events (AEs) and their severity, and identified risk factors for clinical and laboratory AEs. Pharmaceutical-grade STZ was given based on body surface area (BSA) (1050–1250 mg/m2, equivalent to 80–108 mg/kg) or on body weight (BW) (100 mg/kg) to 54 cynomolgus and 24 rhesus macaques. AEs were related to risk factors, i.e. obesity parameters, BW and BSA, age and STZ dose in mg/m2. Clinical AEs during the first days after infusion prompted euthanasia of three animals. Except for those three animals, diabetes was successfully induced as shown by circulating C-peptide levels, the intravenous glucose tolerance test and/or arginine stimulation test. C-peptide after infusion weakly correlated ( P = 0.048) with STZ dose in mg/m2. Grade ≥3 nephrotoxicity or hepatotoxicity (serum markers >3× baseline or >5 × baseline, respectively) occurred in about 10% of cases and were generally mild and reversible. Grade ≥2 clinical AEs occurred in seven of 78 animals, reversed in four cases and significantly correlated with obesity parameters. Taking girth-to-height ratio (GHtR) as an indicator of obesity, with threshold value 0.92–0.95, the positive predictive value of obesity for AEs was 92% and the specificity 94%. We conclude that diabetes is successfully induced in non-obese animals using a 100 mg/kg pharmaceutical grade STZ dose. Obesity is a significant risk factor, and animals with a higher than normal GHtR should preferably receive a lower dose. The incidence of relevant clinical or laboratory AEs is low. Careful monitoring and supportive medical intervention can result in recovery of AEs.
Review of Form-Finding Methods for Tensegrity Structures
Authors: Tibert A.G. , Pellegrino S.
Published: September 2011

Seven form-finding methods for tensegrity structures are reviewed and classified. The three kinematical methods include an analytical approach, a non-linear optimisation, and a pseudo-dynamic iteration. The four statical methods include an analytical method, the formulation of linear equations of equilibrium in terms of force densities, an energy minimisation, and a search for the equilibrium configurations of the struts of the structure connected by cables whose lengths are to be determined, using a reduced set of equilibrium equations. It is concluded that the kinematical methods are best suited to obtaining only configuration details of structures that are already essentially known. The force density method is best suited to searching for new configurations, but affords no control over the lengths of the elements of the structure. The reduced coordinates method offers a greater control on elements lengths, but requires more extensive symbolic manipulations.
A Six Steps Approach to Set up a Measurement Campaign to Validate or Improve the Wind Turbine Component Model
Authors: Holierhoek J. G. , van de Pieterman R.P. , Braam H. , Korterink H.
Published: September 2011

The reliability of mechanical components of wind turbines needs to be improved. In the PROTEST project, a pre-normative project, complementary procedures are developed to improve the specification of the design loads at the interfaces where the mechanical components (pitch and yaw system as well as the drive train) are attached to the wind turbine. This has resulted in a new approach of how to set up and use the prototype measurement campaign. This new approach contains six steps: 1. identify failure modes, 2. design a model, 3. run the load cases, 4. identify input and output certainty, 5. set-up a measurement campaign and 6. process the results to check or improve the models. The main focus of this approach is to enable validation and improvements of the model and its input parameters using a prototype measurement campaign. A flexible approach seems to be essential, as it is unlikely that a strict standard can be created for these components that show several different build-ups and for which very different models are often used. The suggested approach is illustrated using the friction of the pitch bearing as an example.
Unsteady Flow Simulation and Dynamic Stall Behaviour of Vertical Axis Wind Turbine Blades
Authors: Qin Ning , Howell Robert , Durrani Naveed , Hamada Kenichi , Smith Tomos
Published: September 2011

This paper presents a computational study of a rooftop size vertical axis wind turbine with straight blades (H-type turbine). The computational model solves for the two-dimensional and three-dimensional unsteady flow fields around the turbine based on the unsteady Reynolds averaged Navier-Stokes equations and a sliding mesh technique to connect the far-field fixed mesh to the near field rotating mesh around the rotor. Interesting flow features such as dynamic stall around the blades and the interaction of the blade wakes with the following blades are illuminated. Comparison of the 2D and 3D simulations highlight strong three dimensional effects, including the blade tip losses and the effects of the blade supporting shaft and arms. These effects significantly degrade the performance of the VAWT under investigation, pointing a way for improving VAWT designs.
Evaluation of in-plane shear failure in composite laminate with varying ply orientation
Authors: Vali-Shariatpanahi S. , Noroozi S. , Vinney J.
Published: September 2011

This paper presents the results from a study of the in-plane (interlamina) shear characteristics of specific CFRP with a particular balanced lay-up of 12 ply cured laminates. This study involved a detailed experimental program to determine the material properties. The material properties were used for the failure analysis of a new type of fastener joint for composite laminates, which has a potential use in the aerospace industry. Twenty shear tests were carried out using a minimum of 6 specimens for every lay-up. Although some thickness tolerances issues were caused by using different laminate lay-ups, all other geometric parameters were kept similar. Ply failures were observed for 45°/90°, 45°, 90° specimens. An FE model was also developed for each particular lay-up and compared against the test data. It was also used to determine why each coupon failed in a certain way. The FE model uses 2D unsymmetrical material properties with shell elements representing the thickness. In terms of boundary conditions the model was constrained at one end of the specimen and in two directions with a compressive load applied at the other end.
Method of determining key parameters of thread arrangement in structure of single-layer woven fabric for reinforcement of composite textile material
Authors: Chepelyuk Elena , Choogin Valeriy , Hui David , Cousens Jenny
Published: September 2011

In the work, the comparative analysis geometrical model of a transitional site of thread in structure of a woven fabric of a plain wave is resulted. Key parameters of an arrangement of threads in structure of a woven fabric are determined in view of crumple deformation up to the ellipse form of cross-section of a thread. The technology of their calculation is offered. The work could be expanded to industrial fabrics. Suggestion of the technology calculating of the ground parameters of threads disposition in structure of woven fabric are original and have a major contribution to textile science and technology.
Review of algorithms of structural optimization with discrete variables
Authors: Li Yancang , Heng Beibei , Kong Lingren , Yang Weijuan
Published: September 2011

Much work has been done on the optimization of the discrete variable structure design. In order to handle the optimization problem effectively, the related theories, methods, and other beneficial results were summarized. On the basis of analyzing the predecessors' research, the development direction was introduced. Then, some practical methods, including their improvements, for discrete structural optimization were analyzed. Finally, the Ant Colony Optimization algorithms were shown as promising methods. This work has significance in theory and practice for the development of structural optimization.
Development and characterization of carbon-carbon composite for aircraft brake pad using preformed yarn method
Authors: Naik P. , Ibrahim M. , Surendranathan A. , Mujeebu M.
Published: September 2011

This paper presents the synthesizing of carbon-carbon (CC) composites by preformed yarn (PY) method, by varying the percentage of carbon fiber volume. The PY used is carbon fiber bundle surrounded by coke and pitch which is enclosed in nylon-6. Three types of samples with fiber weight fractions of 30%, 40% and 50% respectively, are fabricated and tested. In each case, the PY is chopped and filled into a die of required shape and hot pressed at 600°C to get the carbonized composite. To obtain the graphitic structure, the specimen is heat treated at 1800°C followed by soaking for two hours. Further, one cycle pitch impregnation is done by hot isostatic pressing, to eliminate the voids. The characteristics such as hardness, compressive strength, creep, density and oxidation resistance are studied. It is observed that, as the carbon fiber percentage increases the properties also improved, provided sintering is done at fairly higher temperatures. The superiority of the new class of CC composites made by the proposed PY technique over those obtained by the conventional methods is also demonstrated.
Triggering in a Thermoacoustic System with Stochastic Noise
Authors: Waugh Iain C. , Juniper Matthew P.
Published: September 2011

This paper explores the mechanism of triggering in a simple thermoacoustic system, the Rijke tube. It is demonstrated that additive stochastic perturbations can cause triggering before the linear stability limit of a thermoacoustic system. When triggering from low noise amplitudes, the system is seen to evolve to self-sustained oscillations via an unstable periodic solution of the governing equations. Practical stability is introduced as a measure of the stability of a linearly stable state when finite perturbations are present. The concept of a stochastic stability map is used to demonstrate the change in practical stability limits for a system with a subcritical bifurcation, once stochastic terms are included. The practical stability limits are found to be strongly dependent on the strength of noise.
CFD Analysis of Two-Phase Flow Characteristics in a 90 Degree Elbow
Authors: Mazumder Quamrul H. , Siddique Saiful A.
Published: September 2011

Computational fluid dynamics (CFD) analysis was performed for a two-phase air-water flow through a horizontal to vertical 900 elbow with a 12.7 mm pipe diameter. Three different air velocities of 15.24, 30.48, and 45.72 m/sec along with three different water velocities of 0.1, 1.0, and 10.0 m/sec were used in this study. To analyze the flow behavior in the elbow, pressure and velocity profiles at six different upstream and downstream locations of the elbow were compared. Computational fluid dynamics (CFD) analysis was performed for 9 different cases using FLUENT commercial code. A mixture model was used to account for different gas and liquid velocities to solve continuity, momentum and energy equations. CFD analysis results showed a decrease in pressure as fluid leaves the elbow in addition to a larger pressure drop at higher air velocities. No significant change in pressure was observed when water velocity was increased from 0.1 to 1.0 m/sec compared to water velocity change from 1.0 to 10.0 m/sec. The normalized pressure drop was larger at lower air velocities compared to higher water velocities. CFD analysis results were compared with available experimental data showing a reasonably good agreement.
The Decision Value Computations in the vmPFC and Striatum Use a Relative Value Code That is Guided by Visual Attention
Authors: Lim Seung-Lark , O'Doherty John P. , Rangel Antonio
Published: September 2011

There is a growing consensus in behavioral neuroscience that the brain makes simple choices by first assigning a value to the options under consideration and then comparing them. Two important open questions are whether the brain encodes absolute or relative value signals, and what role attention might play in these computations. We investigated these questions using a human fMRI experiment with a binary choice task in which the fixations to both stimuli were exogenously manipulated to control for the role of visual attention in the valuation computation. We found that the ventromedial prefrontal cortex and the ventral striatum encoded fixation-dependent relative value signals: activity in these areas correlated with the difference in value between the attended and the unattended items. These attention-modulated relative value signals might serve as the input of a comparator system that is used to make a choice.
Chronic Hyperosmotic Stress Converts GABAergic Inhibition into Excitation in Vasopressin and Oxytocin Neurons in the Rat
Authors: Kim Jeong Sook , Kim Woong Bin , Kim Young-Beom , Lee Yeon , Kim Yoon Sik , Shen Feng-Yan , Lee Seung Won , Park Dawon , Choi Hee-Joo , Hur Jinyoung , Park Joong Jean , Han Hee Chul , Colwell Christopher S. , Cho Young-Wuk , Kim Yang In
Published: September 2011

In mammals, the increased secretion of arginine–vasopressin (AVP) (antidiuretic hormone) and oxytocin (natriuretic hormone) is a key physiological response to hyperosmotic stress. In this study, we examined whether chronic hyperosmotic stress weakens GABAAreceptor-mediated synaptic inhibition in rat hypothalamic magnocellular neurosecretory cells (MNCs) secreting these hormones. Gramicidin-perforated recordings of MNCs in acute hypothalamic slices prepared from control rats and ones subjected to the chronic hyperosmotic stress revealed that this challenge not only attenuated the GABAergic inhibition but actually converted it into excitation. The hyperosmotic stress caused a profound depolarizing shift in the reversal potential of GABAergic response (EGABA) in MNCs. ThisEGABAshift was associated with increased expression of Na+–K+–2Cl−cotransporter 1 (NKCC1) in MNCs and was blocked by the NKCC inhibitor bumetanide as well as by decreasing NKCC activity through a reduction of extracellular sodium. Blocking central oxytocin receptors during the hyperosmotic stress prevented the switch to GABAergic excitation. Finally, intravenous injection of the GABAAreceptor antagonist bicuculline lowered the plasma levels of AVP and oxytocin in rats under the chronic hyperosmotic stress. We conclude that the GABAergic responses of MNCs switch between inhibition and excitation in response to physiological needs through the regulation of transmembrane Cl−gradients.
Activation of Spinal μ- and δ-Opioid Receptors Potently Inhibits Substance P Release Induced by Peripheral Noxious Stimuli
Authors: Beaudry Hélène , Dubois Dave , Gendron Louis
Published: September 2011

Over the past few years, δ-opioid receptors (DOPRs) and μ-opioid receptors (MOPRs) have been shown to interact with each other. We have previously seen that expression of MOPR is essential for morphine and inflammation to potentiate the analgesic properties of selective DOPR agonists.In vivo, it is not clear whether MOPRs and DOPRs are expressed in the same neurons. Indeed, it was recently proposed that these receptors are segregated in different populations of nociceptors, with MOPRs and DOPRs expressed by peptidergic and nonpeptidergic fibers, respectively. In the present study, the role and the effects of DOPR- and MOPR-selective agonists in two different pain models were compared. Using preprotachykinin A knock-out mice, we first confirmed that substance P partly mediates intraplantar formalin- and capsaicin-induced pain behaviors. These mice had a significant reduction in pain behavior compared with wild-type mice. We then measured the effects of intrathecal deltorphin II (DOPR agonist) and DAMGO (MOPR agonist) on pain-like behavior, neuronal activation, and substance P release following formalin and capsaicin injection. We found that both agonists were able to decrease formalin- and capsaicin-induced pain, an effect that was correlated with a reduction in the number of c-fos-positive neurons in the superficial laminae of the lumbar spinal cord. Finally, visualization of NK1(neurokinin 1) receptor internalization revealed that DOPR and MOPR activation strongly reduced formalin- and capsaicin-induced substance P release via direct action on primary afferent fibers. Together, our results indicate that functional MOPRs and DOPRs are both expressed by peptidergic nociceptors.
Identification of a Cholinergic Modulatory and Rhythmogenic Mechanism within the Lamprey Respiratory Network
Authors: Mutolo Donatella , Cinelli Elenia , Bongianni Fulvia , Pantaleo Tito
Published: September 2011

Acetylcholine (ACh) is well known to be involved in the control of breathing. However, no information is available on the role of ACh receptors (AChRs) within the lamprey respiratory network. The present study was performed onin vitrobrainstem preparations of adult lampreys to investigate whether ACh affects respiratory activity possibly through an action on the paratrigeminal respiratory group (pTRG) that has been identified as an essential component of the respiratory network. Respiratory activity was monitored as vagal motor output. Bath application of 100 μmphysostigmine or 1 μmnicotine increased respiratory frequency, while bath application of 100 μmd-tubocurarine or 0.25 μmα-bungarotoxin reduced respiratory frequency and increased the duration of vagal bursts. Since these effects were mimicked by microinjections of the same drugs into the pTRG, ACh proved to influence respiratory activity by acting on α7 nicotinic AChRs located within the pTRG. During apnea caused by partial blockade of ionotropic glutamate receptors at the level of the pTRG, bath application of bicuculline and strychnine restored the respiratory rhythm, although at reduced frequency. Similar results were obtained by the concurrent removal of both fast synaptic excitatory and inhibitory transmission. Blockade of pTRG α7 nicotinic AChRs suppressed this respiratory activity, thus indicating that pTRG neurons expressing these receptors contribute to respiratory rhythm generation. Together, these findings identify a novel cholinergic modulatory and possibly subsidiary rhythmogenic mechanism within the respiratory network of the adult lamprey and encourage further studies on the respiratory role of cholinergic receptors in different animal species.
Dense, Unspecific Connectivity of Neocortical Parvalbumin-Positive Interneurons: A Canonical Microcircuit for Inhibition?
Authors: Packer Adam M. , Yuste Rafael
Published: September 2011

GABAergic interneurons play a major role in the function of the mammalian neocortex, but their circuit connectivity is still poorly understood. We used two-photon RuBi-Glutamate uncaging to optically map how the largest population of cortical interneurons, the parvalbumin-positive cells (PV+), are connected to pyramidal cells (PCs) in mouse neocortex. We found locally dense connectivity from PV+ interneurons onto PCs across cortical areas and layers. In many experiments, all nearby PV+ cells were connected to every local PC sampled. In agreement with this, we found no evidence for connection specificity, as PV+ interneurons contacted PC pairs similarly regardless of whether they were synaptically connected or not. We conclude that the microcircuit architecture for PV+ interneurons, and probably neocortical inhibition in general, is an unspecific, densely homogenous matrix covering all nearby pyramidal cells.
Wnt Signaling in Amygdala-Dependent Learning and Memory
Authors: Maguschak Kimberly A. , Ressler Kerry J.
Published: September 2011

In addition to its role in cellular development and proliferation, there are emergingin vitrodata implicating the Wnt/β-catenin pathway in synaptic plasticity. Yetin vivostudies have not examined whether Wnt activity is required for learning and memory. In the amygdala during fear memory formation, we found that many Wnt-signaling genes were dynamically regulated, with an immediate decrease, followed by an eventual normalization during memory consolidation. This rapid decrease in Wnt mRNA was confirmed with individual quantitative PCR andin situhybridization. We then manipulated Wnt signaling with a specific peptide antagonist (Dkk-1) or agonist (Wnt1) injected stereotaxically into the adult amygdala during fear learning. We found that neither manipulation had an effect on locomotion, anxiety, fear acquisition, or fear expression. However, both Wnt modulators prevented long-term fear memory consolidation without affecting short-term memory. Dkk-1 and Wnt infusions had destabilizing, but opposite, effects on the requisite β-catenin/cadherin dynamic interactions that occur during consolidation. These data suggest that dynamic modulation of Wnt/β-catenin signaling during consolidation is critical for the structural basis of long-term memory formation.
Pan-Neuronal Knockdown of Calcineurin Reduces Sleep in the Fruit Fly,Drosophila melanogaster
Authors: Tomita Jun , Mitsuyoshi Madoka , Ueno Taro , Aso Yoshinori , Tanimoto Hiromu , Nakai Yasuhiro , Aigaki Toshiro , Kume Shoen , Kume Kazuhiko
Published: September 2011

Sleep is a unique physiological state, which is behaviorally defined, and is broadly conserved across species from mammals to invertebrates such as insects. Because of the experimental accessibility provided by various novel animal models including the fruit fly,Drosophila melanogaster, there have been significant advances in the understanding of sleep. Although the physiological functions of sleep have not been fully elucidated, accumulating evidence indicates that sleep is necessary to maintain the plasticity of neuronal circuits and, hence, is essential in learning and memory. Calcineurin (Cn) is a heterodimeric phosphatase composed of CnA and CnB subunits and known to function in memory consolidation in the mammalian brain, but its neurological functions in the fruit fly are largely unknown. Here, we show that Cn is an important regulator of sleep inDrosophila. A pan-neuronal RNA interference-mediated knockdown ofCnexpression resulted in sleep loss, whereas misexpression of the constitutively active form of a CnA protein led to increased sleep. Furthermore,CnAknockdown also impaired the retention of aversive olfactory memory. These results indicate a role for Cn and calcium-dependent signal transduction in sleep and memory regulation and may bring insight into the relationship between them.
Adaptive Changes in Neuronal Synchronization in Macaque V4
Authors: Wang Ye , Iliescu Bogdan F. , Ma Jianfu , Josić Krešimir , Dragoi Valentin
Published: September 2011

A fundamental property of cortical neurons is the capacity to exhibit adaptive changes or plasticity. Whether adaptive changes in cortical responses are accompanied by changes in synchrony between individual neurons and local population activity in sensory cortex is unclear. This issue is important as synchronized neural activity is hypothesized to play an important role in propagating information in neuronal circuits. Here, we show that rapid adaptation (300 ms) to a stimulus of fixed orientation modulates the strength of oscillatory neuronal synchronization in macaque visual cortex (area V4) and influences the ability of neurons to distinguish small changes in stimulus orientation. Specifically, rapid adaptation increases the synchronization of individual neuronal responses with local population activity in the gamma frequency band (30–80 Hz). In contrast to previous reports that gamma synchronization is associated with an increase in firing rates in V4, we found that the postadaptation increase in gamma synchronization is associated with a decrease in neuronal responses. The increase in gamma-band synchronization after adaptation is functionally significant as it is correlated with an improvement in neuronal orientation discrimination performance. Thus, adaptive synchronization between the spiking activity of individual neurons and their local population can enhance temporally insensitive, rate-based-coding schemes for sensory discrimination.
Developing the “Christian Gentleman”: The Medieval Impulse in Protestant Ministry to Adolescent Boys, 1890–1920
Authors: Setran David P.
Published: September 2011

Between 1890 and 1920 in the United States, Protestant ministers demonstrated increasing concern for boys between the ages of twelve and eighteen. In particular, they described a two-fold “boy problem,” defined both in terms of heightened juvenile delinquency and passive effeminacy. This essay analyzes one of the chief ways in which church leaders attempted to combat these issues: the development of Christian boy ministries rooted in the stories and themes of medieval knighthood. Looking at the use of such themes in Protestant literature and in new church organizations such as the Knights of King Arthur and the Knights of the Holy Grail, this article reveals why medievalism had such power and resonance in this era. In part, the symbolic use of the Middle Ages fit well with emerging psychological theories of adolescent development. According to G. Stanley Hall and other proponents of racial recapitulation, adolescent boys were instinctually driven by a need to join their medieval forebears in fighting battles, worshiping heroes, and forming romantic relationships marked by love and chivalry. In addition, the medieval knight emerged as the ideal exemplar for dealing with both aspects of the early twentieth-century boy problem. While boys struggled with moral decadence and effeminate weakness, knights were both morally refined and confidently virile. In the end, I argue that the proliferation of medieval themes in this period reflected a growing consensus regarding the “ideal Christian man.” While uncontrolled masculine expression produced the violent man, and the suppression of masculine expression produced the weak man, carefully channeled masculine expression would produce the “knightly” man, the ideal “Christian gentleman” capable of pursuing purity and virtue through manly and aggressive means.
The Preachers’ Blues: Religious Race Records and Claims of Authority on Wax
Authors: Walton Jonathan L.
Published: September 2011

As one of the first nonessential commodities marketed to African Americans, the race record industry provides historical insight into the cultural ethos and competing ethical values of black communities during the interwar period. Both ethnomusicologists and historians have discussed the ways race records articulate intraracial conflicts that were exacerbated by social factors such as migration and urbanization. But like all forms of mass culture, religious records served multiple purposes and were interpreted by listeners at varying registers. For many, religious recordings were spiritually edifying and liberating, just as they were wildly entertaining. And some may feel that these religious recordings contested the aesthetic values of the black middle class even as they reinforced prescriptive bourgeois behavioral codes. While the purpose of this essay is not to give voice to the listeners of religious race records, this essay does offer an initial attempt to illumine the broader cultural contexts in which these records, namely, recorded sermons, were both produced and consumed toward providing tenable interpretations of these recordings based on resonant religious beliefs and meanings of the historical moment. This essay is concerned with such questions as: What theological and political discourses were these preachers participating in on wax? What cultural symbols, explicit and implicit, did these preachers commonly reference? And what were the possible ideological implications of these cultural significations? Despite the many interpretive possibilities of recorded sermons and even the “folk” aesthetic that defines them, this essay suggests that the religious race record industry served as a productive force in encouraging systems of social control over raced, classed, and gendered bodies during the interwar era. And the industry’s decision to focus on theologically conservative sermons stressing personal piety cast a powerful ballot in the cultural debates concerning the style, content, and purpose of black preaching in the previous century.
Transcatheter aortic valve replacement (TAVI) — Risk factors for 90-day-mortality
Authors: Bauernschmitt R.
Published: September 2011

Transcatheter aortic valve implantation (TAVI) has emerged as a promising new treatment option for patients being “too sick” for surgery, with an almost exponentially increasing number of cases done in the recent years. While procedural success is satisfying in any series reported, there still is a lack of information concerning proper patient selection for these procedures. All operations were performed at the Dept. of Cardiovascular Surgery, German Heart Center Munich. From July 2007 to February 2010, a total of 368 patients had transcatheter procedures, 300 of them completed the 90-day-follow-up. Their mean age was 81+/−6 years, 62.7% of them being female. The CoreValve prosthesis was implanted in 213 patients (71%), the femoral route was predominantly used (65%). Among preoperative characteristics, only advanced NYHA-class and tricuspid regurgitation more than moderate were indicators for increased 90-day-mortality. TAVI has become an increasingly safe alternative to open heart aortic valve replacement in patients at high risk for conventional surgery. While there still is room for improvement of intraprocedural steps, the only predictive risk factors for 90-day-mortality were NYHA class IV and high grade tricuspid insufficiency, thus indicating that TAVI puts the patient at an unaccountable high risk.
Increased sympathetic activity can cause repolarization instability in athlete's heart
Authors: Komka Zsolt , Bosnyák E. , Trájer E. , Protzner A. , Major Zs. , Pavlik G. , Tóth M. , Udvardy A.
Published: September 2011

Sudden cardiac death (SCD) of athletes usually occurs during warm-up or shortly after training. At this point sympathetic tone is still elevated but oxygen demand does not differ from resting levels. It is supposed not to have a primarily ischemic origin but most likely relates to repolarization abnormalities which can be associated with intracellular cAMP level caused by increased sympathetic tone. The mediators of sympathetic nervous system are the catecholamines (epinephrin, norepinephrin). Measuring QT-dispersion can show the repolarization's inhomogeneity. 27 elite soccer players, 28 triathletes and 29 non-trained control person took part in our study. It was recorded cardiac ultrasound, an ECG and taken blood before and after exercise. We found significantly higher QT-dispersion and catecholamines in soccer players compared to the triathletes and the controls. However the soccer players did not show larger athlete's heart than the triathletes. After exercise the increased repolarization inhomogeneity persisted in soccer players, but in triathletes it decreased. Increased sympathetic tone in athletes can enhance arrhythmia propensity. Our data may explain why the soccer players die of sudden cardiac death most commonly in Europe.
Real-time three-dimensional transesophageal echocardiography-guided atrial fibrillation ablation procedure
Authors: Kutyifa Valentina , Merkely B. , Nagy V. K. , Apor A. , Zima E. , Gellér L.
Published: September 2011

Background

Real-time three-dimensional transesophageal echocardiography (RT 3D TEE) is a novel method providing high spatial and temporal resolution imaging of the heart. During pulmonary vein isolation procedures visualization of the atria, interatrial septum and the ablation catheter is of high importance to increase safety. RT 3D TEE might be a useful tool to guide left atrial ablations.

Case report

A 53-year-old man was referred to our hospital to undergo pulmonary vein isolation procedure for the treatment of symptomatic drug-refractory paroxysmal atrial fibrillation. The transseptal puncture was performed under RT 3D TEE-guidance with direct visualization of the interatrial septum and fossa ovalis. RT 3D TEE provided a three-dimensional view of the puncture with “tenting”-sign and the transseptal needle-fossa ovalis angle enhancing the manipulation of the ablation catheter within the left atrium. The ablation catheter was visualized and tracked during the procedure. No adverse events occurred during the procedure.

Conclusion

Our case report demonstrates the feasibility of RT 3D TEE-guided atrial fibrillation ablation procedures. Safety profile might be improved by the real-time direct view of fossa ovalis. Decrease in fluoroscopy time can be achieved by visualizing the ablation catheter during the procedure.
High prevalence of duodenal ulcer in a tertiary care hospital in the city of São Paulo, SP, Brazil
Authors: Marques Sergio B. , Mattar Rejane , Artifon Everson L. A. , Sakai Paulo , Carrilho Flair José
Published: September 2011

CONTEXT: In spite of Helicobacter pylori infection being the etiological cause of peptic ulcer and its high prevalence in Brazil, the prevalence of peptic ulcer disease has been poorly studied. OBJECTIVES: To verify the peptic ulcer disease prevalence in patients of a tertiary care hospital. METHODS: Diagnostic findings from 1,478 consecutive endoscopies were correlated with the urease test results for H. pylori infection diagnosis and demographic data in a total of 3,779 endoscopies performed in 2005. The mean age of the patients was 51.14 ± 16.46, being 613 (41.5%) men. RESULTS: Peptic ulcer was diagnosed in 494 (33.4%) patients with a mean age of 54.86 ± 14.53, 205 (52%) were men, being 391 (26.5%) duodenal ulcer and 103 (7%) gastric ulcer. Normal endoscopy was found in 272 (18.4%) patients with a mean age of 38.4 ± 15.22, being 49 (18%) men. The comparison of peptic ulcer group with the patients that had normal endoscopy revealed that H. pylori infection [P = 0.005; OR = 1.70; 95% CI = 1.17-2.47][ign], male gender [P<0.0001; OR = 5.53; 95%CI = 3.67-8.34][ign] and older age [P<0.0001; OR = 1.08; 95%CI = 1.06-1.09] increased the risk of peptic ulcers. The overall H. pylori prevalence was 53% (786). CONCLUSIONS: Prevalence of duodenal ulcer is high in a Brazilian population that had H. pylori infection associated with older age and male gender as important determinants to gastrointestinal diseases outcome. Future prospective studies should confirm these findings.
Adherence of enteroaggregative Escherichia coli to the ileal and colonic mucosa: an in vitro study utilizing the scanning electron microscopy
Authors: Andrade Jacy Alves Braga de , Freymüller Edna , Fagundes-Neto Ulysses
Published: September 2011

CONTEXT: Enteroaggregative Escherichia coli strains have been associated with persistent diarrhea in several developing countries. In vivo procedures with animal models, in vitro assays with cellular lines and in vitro organ culture with intestinal fragments have been utilized to study these bacteria and their pathogenicity. OBJECTIVE: The present experimental research assessed the pathogenic interactions of three enteroaggregative Escherichia coli strains, using the in vitro organ culture, in order to show the adherence to different regions of both, the ileal and the colonic mucosa and demonstrate possible mechanisms that could have the participation in the prolongation of diarrheiogenic process. METHODS: This study used intestinal fragments from terminal ileum and colon that were excised from pediatric patients undergoing intestinal surgeries and from adult patients that underwent to colonoscopic procedures. Each strain was tested with three intestinal fragments for each region. Tissue was fixed for scanning electron microscopic analysis. RESULTS: These bacteria colonized ileal and colonic mucosa in the typical stacked-brick configuration in the ileum and colon. In both regions, the strains were seen over a great amount of mucus and sometimes over the intact epithelium. In some regions, there is a probable evidence of effacement of the microvilli. It was possible to see adhered to the intestinal surface, bacteria fimbrial structures that could be responsible for the adherence process. CONCLUSION: In order to cause diarrhea, enteroaggregative Escherichia coli strains adhere to the intestinal mucosa, create a mucoid biofilm on the small bowel surface that could justify the digestive-absorptive abnormalities and consequently, prolonging the diarrhea.
Analysis of myosin-V immunoreactive myenteric neurons from arthritic rats
Authors: Souza Ivan Domicio da Silva , Ribeiro Janine Silva , Bersani-Amado Ciomar Aparecida , Zanoni Jacqueline Nelisis
Published: September 2011

CONTEXT: The inflammatory response itself and the consequent oxidative stress are able to promote neurodegeneration. So, it is possible that enteric nervous system is affected by inflammatory diseases threatening quality of life of patients. However, gastrointestinal symptoms of arthritis are usually attributed to anti-inflammatory drugs rather than neural damage. OBJECTIVE: To confirm if the general population of myenteric neurons from the ileum and jejunum of rats is affected by arthritis. METHODS: Twenty Holtzmann rats, 58-day-old male, were used and divided in four groups: control group (C30), arthritic group (Art30), older control group (C60) and older arthritic group (Art60). At 58 days old, the animals in groups Art30 and Art60 received an injection of the complete Freund's adjuvant in order to induce arthritis. The whole-mount preparations of ileum and jejunum were processed for myosin-V immunohistochemistry. Quantitative and morphometric analyses were performed. RESULTS: Groups Art30 and Art60 presented, respectively, a reduction of 2% and 6% in intestinal area when compared to their control groups. No significant differences were observed in general neuronal density among the four groups (P>0.05). Group C60 presented a reduction of 14.4% and 10.9% in mean neuronal cell body area when compared to group C30 (P<0.05), for the ileum and jejunum, respectively. The other groups had a similar mean neuronal cell body area (P>0.05). CONCLUSION: Arthritis does not promote quantitative or morphological damages in general myenteric population. However, studies in progress have revealed some significant alterations in myenteric neurons subpopulations (nitrergic and VIP-ergic neurons).
Protection of estrogen in portal hypertension gastropathy: an experimental model
Authors: Morgan-Martins Maria Isabel , Jacques Simone Iahnig , Hartmann Renata Minuzzo , Marques Camila Moraes , Marroni Cláudio Augusto , Marroni Norma Possa
Published: September 2011

CONTEXT: Portal hypertension is a complication secondary to cirrhosis that is characterized by increased blood flow and/or vascular resistance in the portal system, causing the appearance of a hyperdynamic collateral circulation. Partial portal vein ligation is an experimental model used in rats to study the pathophysiological mechanisms involved in pre-hepatic portal hypertension. Estrogen E2 is an antioxidant molecule with various physiological actions. OBJECTIVES: To evaluate the antioxidant activity of endogenous estrogen in an experimental model of partial portal vein ligation by comparing intact with castrated rats. METHODS: Twenty Wistar rats, weighing on average 250 g were used and divided into four groups: sham-operated (SO); intact (I) with partial portal vein ligation (I + PPVL), castrated (C) and castrated with partial ligation of the vein (C + PPVL). Day 1: castration or sham-operation; day 7, PPVL surgery; on day 15 post-PPVL, portal pressure in the mesenteric vein of rats was measured on polygraph Letica. Lipid peroxidation in the stomach was assessed using the technique of thiobarbituric acid reactive substances and activity of antioxidant enzymes superoxide dismutase, catalase and glutathione peroxidase. Statistical analysis was done with ANOVA - Student-Newman-Keuls (mean ± SE), and P<0.05 was considered as significant. RESULTS: Portal pressure was significantly increased in C + PPVL as compared to the other groups. There was no significant difference in the group of intact rats. TBARS showed significant damage in C and C + PPVL in relation to others. Antioxidant enzymes were significantly increased in the castrated rats with subsequent PPVL as compared to the other groups. CONCLUSION: We suggest that estrogen E2 plays a protective role in intact compared with castrated rats because it presents hydrophenolic radicals in its molecule, thus acting as an antioxidant in this experimental model.
Capsule endoscopy in clinical practice: four years of experience from a single center
Authors: Freitas Gustavo Pignaton de , Teixeira Newton , Feldman Gregorio
Published: September 2011

Capsule endoscopy is a diagnostic method of increasing use nowadays, with various applications such as, evaluation of obscure gastrointestinal bleeding, chronic diarrhea and anemia. The experience of 4 years is reported in a retrospective review of 109 medical records to determine the main indications and the most common diagnostic findings and the percentage of positive studies. The main indications were obscure bleeding in 65%, chronic anemia in 8%. Vascular lesions in 33%, being that, hematocistic spot was found in 53% of studies. The location of active bleeding was possible in five patients (4.5%). Capsule endoscopy shows a high diagnostic yield in obscure bleeding.
Parto e mascimento: uma compreensão das possibilidades de inserção da enfermeira
Authors: Simões Sonia Mara Faria
Published: September 2011

A pesquisa teve como objetivo compreender a inserção da enfermeira no cenário das propostas e políticas públicas de assistência ao parto e nascimento. De natureza qualitativa, abordagem fenomenológica, utilizou como fontes documentos oficiais, periódicos de enfermagem, livros, jornais. A hermenêutica revelou que o acontecer da enfermeira ocorreu como ocupação caracterizada por ações repetidas voltadas para redução de índices de morbimortalidade materno-infantil. Porém a visão desta realidade possibilitou aos profissionais e estudiosos buscar caminhos que permitissem uma re-inserção da enfermeira pautada em conhecimento científico e prática efetiva, tais como alterações curriculares, ênfase na legalidade do exercício profissional e reivindicação de políticas de recursos humanos nas diversas instâncias do governo. Todos esses acontecimentos nos remetem a compreensão de um per-curso ambíguo no qual a enfermeira obstetra busca publicamente sua direção, num projetar-se para as suas possibilidades mais próprias de atuação profissional.
Uma leitura da recente produção científica socializada pela REBEn
Authors: Bagnato Maria Helena Salgado , Rodrigues Rosa Maria , Cocco Maria Inês Monteiro
Published: September 2011

O texto traz uma primeira aproximação com o "estado da arte" da pesquisa em enfermagem no Brasil. É parte de uma pesquisa que analisará outros dois periódicos indexados. Partiu-se de 250 resumos e notas de rodapé da Revista Brasileira de Enfermagem (REBEn), nos últimos cinco anos, a partir de 1997. Os dados foram tabulados e distribuídos em tabelas. Concluímos que houve predominância de trabalhos de pesquisa; com certa homogeneidade nas temáticas abordadas; tendência à produção coletiva; predominância das universidades públicas na produção do conhecimento, bem como de órgãos públicos no financiamento dos trabalhos. Avaliamos que a REBEn tem se constituído em importante veículo de socialização da produção do conhecimento em enfermagem.
Arqueologia e genealogia como opções metodológicas de pesquisa na enfermagem
Authors: Azevedo Rosemeiry Capriata de Souza , Ramos Flavia Regina Souza
Published: September 2011

Este artigo parte da contextualização histórica sobre o desenvolvimento da pesquisa em enfermagem, apresenta as categorias/linhas de interesse que subjazem o conhecimento humano aplicado nas Teses de Doutorado em Enfermagem no Brasil, aponta os métodos arqueológico e genealógico proposto por Michel Foucault e sua possibilidade de problematizar o cotidiano da enfermagem seja no âmbito Institucional, das Políticas Públicas, Reforma Sanitária e Formação Profissional, na tentativa de entender que estratégias, lutas, saberes e práticas têm influenciado a construção dos sujeitos.
Racionalidade substantiva no processo decisório: um estudo em instituições que lidam com o tratamento oncológico infantojuvenil na cidade de Natal (RN)
Authors: Silva Miriam Soares de Oliveira e , Fernandes Antônio Sérgio Araújo
Published: September 2011

O presente trabalho trata de um estudo sobre a racionalidade substantiva no processo decisório em duas instituições que lidam com o tratamento oncológico em crianças e adolescentes na cidade de Natal, no estado do Rio Grande Norte. A partir de uma revisão de literatura sobre a racionalidade substantiva, o objetivo da pesquisa é perceber aspectos relacionados ao processo decisório que possam servir de base para elaborar as categorias de análise do processo Tomada de Decisão, agregando-as a um novo estudo que possa proporcionar o avanço do tema na ciência administrativa. Serviram de base para o aprofundamento do tema os trabalhos acadêmicos que seguiram o modelo de análise elaborado por Maurício Serva, cujo quadro verifica a racionalidade predominante em 11 processos administrativos internos em organizações produtivas. Tendo como base teórica a obra de Guerreiro Ramos, que constata a existência de um tipo de organização ideal, o estudo recorre ao pensamento de Karl Polanyi, que procura compreender o fenômeno econômico independente do valor que permite considerar economias não mercantis. Para melhor compreender a racionalidade resgatam-se os estudos de Max Weber, que investiga o significado de ação social, e com Jürgen Habermas se tem uma concepção mais abrangente de razão através da teoria da ação comunicativa. Como resultado da revisão do tema foi elaborado um quadro com sete categorias de análise que, aplicadas nas instituições pesquisadas, tornou possível conhecer a racionalidade predominante no processo decisório. Os resultados da pesquisa confirmam que, embora a decisão envolva elementos racionais, existem também valores específicos de cada indivíduo ligados à sua experiência de visão de mundo, permeados não só pela racionalidade instrumental como também pela racionalidade substantiva. O estudo comprovou que duas instituições pertencentes ao mesmo setor podem apresentar diferentes tipos de racionalidade na tomada de decisão, quando fatores decisórios podem tender para a racionalidade instrumental, de acordo com o pensamento clássico da administração, como também podem emergir da racionalidade substantiva, contribuindo para o processo de emancipação do ser humano na esfera do trabalho.