bluuebunny/crossref_metadata_2025 huggingface dataset:
SENSITIVE RESPONSE OF A CHAOTIC WANDERING STATE TO MEMORY FRAGMENT INPUTS IN A CHAOTIC NEURAL NETWORK MODEL
Authors: KUROIWA JOUSUKE , MASUTANI NAOKI , NARA SHIGETOSHI , AIHARA KAZUYUKI
Published: May 2004

Dynamical properties of a chaotic neural network model in a chaotically wandering state are studied with respect to sensitivity to weak input of a memory fragment. In certain parameter regions, the network shows weakly chaotic wandering, which means that the orbits of network dynamics in the state space are localized around several memory patterns. In the other parameter regions, the network shows highly developed chaotic wandering, that is, the orbits become itinerant through ruins of all the memory patterns. In the latter case, once the external input consisting of a memory fragment is applied to the network, the orbit quickly moves to the vicinity of the corresponding memory pattern including the memory fragment within several iteration steps. Thus, chaotic dynamics in the model is effective for instantaneous search among memory patterns.
CHAOTIFICATION OF DISCRETE-TIME SYSTEMS USING NEURONS
Authors: KWOK H. S. , TANG WALLACE K. S.
Published: May 2004

In this paper, a neuron is introduced for chaotifying nonchaotic discrete-time systems with arbitrary dimensions. By modeling the neuron with a hyperbolic tangent activation function, a scalar feedback signal expressed in a linear combination of the neuron outputs is used. Chaos can then be generated from the controlled discrete-time system. The existence of chaos is verified by both theoretical proof and computer simulations.
TRACKING CONTROL OF NONLINEAR SYSTEMS: A SLIDING MODE DESIGN VIA CHAOTIC OPTIMIZATION
Authors: LU ZHAO , SHIEH LEANG-SAN , CHANDRA JAGDISH
Published: May 2004

The output tracking for a general family of nonlinear systems presents formidable technical challenges. In this paper, we present a novel scheme for tracking control of a class of affine nonlinear systems with multi-inputs. This effective procedure is based on a new sliding mode design for tracking control of such nonlinear systems. The construction of an optimal sliding mode is a difficult problem and no systematic and efficient method is currently available. Here, we develop an innovative approach that utilizes a chaotic optimizing algorithm, which is then successfully applied to obtain the optimal sliding manifold. The existing efficient reaching law approach is then utilized to synthesize the sliding mode control law. The sliding mode control scheme proposed here is particularly appropriate for robust tracking of the chaotic motion trajectory.
PARAMETER IDENTIFICATION OF CHAOTIC SYSTEMS USING WAVELETS AND NEURAL NETWORKS
Authors: AL-ASSAF YOUSEF , AHMAD WAJDI M.
Published: May 2004

This paper addresses the problem of reconstructing a slowly-varying information-bearing signal from a parametrically modulated, nonstationary dynamical signal. A chaotic electronic oscillator model characterized by one control parameter and a double-scroll-like attractor is used throughout the study. Wavelet transforms are used to extract features of the chaotic signal resulting from parametric modulation of the control parameter by the useful signal. The vector of feature coefficients is fed into a feed-forward neural network that recovers the embedded information-bearing signal. The performance of the developed method is cross-validated through reconstruction of randomly-generated control parameter patterns. This method is applied to the reconstruction of speech signals, thus demonstrating its potential utility for secure communication applications. Our results are validated via numerical simulations.
INTERESTING SYNCHRONIZATION-LIKE BEHAVIOR
Authors: ERJAEE G. H. , ATABAKZADE M. H. , SAHA L. M.
Published: May 2004

We analyze the behavior of some coupled chaotic systems, which are synchronization-like. This phenomenon occurs when all conditional Lyapunov exponents of a system are not negative. Recently, Shuaiet et al. [1997] observed that synchronization can be achieved even with positive conditional Lyapunov exponents. In this paper we review this observation, and, based on this observation, we will see that not only interesting synchronization behaviors occur with positive or zero conditional Lyapunov exponents, but also these behaviors depend on different eigenvalues of the linearized system describing the evolution of the difference between the pair of chaotic systems.
CONTINUOUS EXTENSIONS ARE NOT HÖLDER
Authors: HU JUN
Published: May 2004

Let Q denote a quadratic polynomial and A∞ the super-attracting basin of Q at the point ∞ on the Riemann sphere [Formula: see text]. There exists a unique Riemann mapping Φ from the open disk [Formula: see text] onto A∞ such that Φ(∞)=∞, Φ'(∞)=1 and Φ-1 conjugates Q:A∞→A∞ to the squaring map S:D→D:z↦z2. In this paper, we show if Q is real and infinitely renormalizable of bounded type then the continuous extension of Φ to the closed disk cannot have any Hölder continuity on the boundary circle [Formula: see text].
CLASSIFICATION OF THE SPATIAL EQUILIBRIA OF THE CLAMPED ELASTICA: NUMERICAL CONTINUATION OF THE SOLUTION SET
Authors: HENDERSON MICHAEL E. , NEUKIRCH SÉBASTIEN
Published: May 2004

We consider equilibrium configurations of inextensible, unshearable, isotropic, uniform and naturally straight and prismatic rods when subject to end loads and clamped boundary conditions. In a first paper [Neukirch & Henderson, 2002], we discussed symmetry properties of the equilibrium configurations of the center line of the rod. Here, we are interested in the set of all parameter values that yield equilibrium configurations that fulfill clamped boundary conditions. We call this set the solution manifold and we compute it using a recently introduced continuation algorithm. We then describe the topology of this manifold and how it comprises different interconnected layers. We show that the border set of the different layers is the well-known solution set of buckled rings.
MATRIX INTEGRALS AND THE GENERATION AND COUNTING OF VIRTUAL TANGLES AND LINKS
Authors: ZINN-JUSTIN PAUL , ZUBER JEAN-BERNARD
Published: May 2004

Virtual links are generalizations of classical links that can be represented by links embedded in a "thickened" surface Σ×I, product of a Riemann surface of genus h with an interval. In this paper, we show that virtual alternating links and tangles are naturally associated with the 1/N2 expansion of an integral over N×N complex matrices. We suggest that it is sufficient to count the equivalence classes of these diagrams modulo ordinary (planar) flypes. To test this hypothesis, we use an algorithm coding the corresponding Feynman diagrams by means of permutations that generates virtual diagrams up to 6 crossings and computes various invariants. Under this hypothesis, we use known results on matrix integrals to get the generating functions of virtual alternating tangles of genus 1 to 5 up to order 10 (i.e. 10 real crossings). The asymptotic behavior for n large of the numbers of links and tangles of genus h and with n crossings is also computed for h=1,2,3 and conjectured for general h.
THE CONDITIONAL NODE CONNECTIVITY OF THE k-ARY n-CUBE
Authors: DAY KHALED
Published: May 2004

This paper derives the conditional node connectivity of the k-ary n-cube interconnection network under the condition of forbidden faulty sets (i.e. assuming that each non-faulty processor has at least one non-faulty neighbor). It is shown that under this condition and for k≥4 and n≥2, the k-ary n-cube, whose connectivity is 2n, can tolerate up to 4n-3 faulty nodes without becoming disconnected. The conditional node connectivity in this case is therefore 4n-2. For k=3 and n≥2 the established conditional node connectivity is 4n-3. The result for the remaining smaller values of k and n are also obtained.
AVERAGE-CASE SCALABILITY ANALYSIS OF PARALLEL COMPUTATIONS ON k-ARY d-CUBES
Authors: LI KEQIN
Published: May 2004

We investigate the average-case scalability of parallel algorithms executing on multicomputer systems whose static networks are k-ary d-cubes. Our performance metrics are isoefficiency function and isospeed scalability. For the purpose of average-case performance analysis, we formally define the concepts of average-case isoefficiency function and average-case isospeed scalability. By modeling parallel algorithms on multicomputers using task interaction graphs, we are mainly interested in the effects of communication overhead and load imbalance on the performance of parallel computations. We focus on the topology of static networks whose limited connectivities are constraints to high performance. In our probabilistic model, task computation and communication times are treated as random variables, so that we can analyze the average-case performance of parallel computations. We derive the expected parallel execution time on symmetric static networks and apply the result to k-ary d-cubes. We characterize the maximum tolerable communication overhead such that constant average-case efficiency and average-case average-speed could be maintained and that the number of tasks has a growth rate Θ(P log P), where P is the number of processors. It is found that the scalability of a parallel computation is essentially determined by the topology of a static network, i.e., the architecture of a parallel computer system. We also argue that under our probabilistic model, the number of tasks should grow at least in the rate of Θ(P log P), so that constant average-case efficiency and average-speed can be maintained.
Sympathetic innervation of white adipose tissue and its regulation of fat cell number
Authors: Bowers Robert R. , Festuccia William T. L. , Song C. Kay , Shi Haifei , Migliorini Renato H. , Bartness Timothy J.
Published: May 2004

White adipose tissue (WAT) is innervated by the sympathetic nervous system (SNS), and the central origins of this innervation have been demonstrated for inguinal and epididymal WAT (iWAT and eWAT, respectively) using a viral transneuronal tract tracer, the pseudorabies virus (PRV). Although the more established role of this sympathetic innervation of WAT is as a major stimulator of lipid mobilization, this innervation also inhibits WAT fat cell number (FCN); thus, local denervation of WAT leads to marked increases in WAT mass and FCN. The purpose of this study was to extend our understanding of the SNS regulation of FCN using neuroanatomical and functional analyses. Therefore, we injected PRV into retroperitoneal WAT (rWAT) to compare the SNS outflow to this pad from what already is known for iWAT and eWAT. In addition, we tested the ability of local unilateral denervation of rWAT or iWAT to promote increases in WAT mass and FCN vs. their contralateral neurally intact counterparts. Although the overall pattern of innervation was more similar than different for rWAT vs. iWAT or eWAT, its SNS outflow appeared to involve more neurons in the suprachiasmatic and solitary tract nuclei. Denervation produced significant increases in WAT mass and FCN for both iWAT and rWAT, but FCN was increased significantly more in iWAT than in rWAT. These data suggest differences in origins of the sympathetic outflow to WAT and functional differences in the WAT SNS innervation that could contribute to the differential propensity for fat cell proliferation across WAT depots in vivo.
Abdominal vagal mediation of the satiety effects of CCK in rats
Authors: Reidelberger Roger D. , Hernandez Jessica , Fritzsch Bernd , Hulce Martin
Published: May 2004

CCK type 1 (CCK1) receptor antagonists differing in blood-brain barrier permeability were used to test the hypothesis that satiety is mediated in part by CCK action at CCK1 receptors on vagal sensory nerves innervating the small intestine. Devazepide penetrates the blood-brain barrier; A-70104, the dicyclohexylammonium salt of Nα-3-quinolinoyl-d-Glu- N,N-dipentylamide, does not. At dark onset, non-food-deprived control rats and rats with subdiaphragmatic vagotomies received a bolus injection of devazepide (2.5 μmol/kg iv) or a 3-h infusion of A-70104 (3 μmol·kg−1·h−1 iv) either alone or coadministered with a 2-h intragastric infusion of peptone (0.75 or 1 g/h). Food intake was determined from continuous computer recordings of changes in food bowl weight. In control rats both antagonists stimulated food intake and attenuated the anorexic response to intragastric infusion of peptone. In contrast, only devazepide was effective in stimulating food intake in vagotomized rats. Thus endogenous CCK appears to act both at CCK1 receptors beyond the blood-brain barrier and by a CCK1 receptor-mediated mechanism involving abdominal vagal nerves to inhibit food intake.
Interleukin-6 impairs endothelium-dependent NO-cGMP-mediated relaxation and enhances contraction in systemic vessels of pregnant rats
Authors: Orshal Julia M. , Khalil Raouf A.
Published: May 2004

IL-6 is elevated in plasma of preeclamptic women, and twofold elevation of plasma IL-6 increases vascular resistance and arterial pressure in pregnant rats, suggesting a role of the cytokine in hypertension of pregnancy. However, whether the hemodynamic effects of IL-6 reflect direct effects of the cytokine on the mechanisms of vascular contraction/relaxation is unclear. The purpose of this study was to test the hypothesis that IL-6 directly impairs endothelium-dependent relaxation and enhances vascular contraction in systemic vessels of pregnant rats. Active stress was measured in aortic strips isolated from virgin and late pregnant Sprague-Dawley rats and then nontreated or treated for 1 h with IL-6 (10 pg/ml to 10 ng/ml). In endothelium-intact vascular strips, phenylephrine (Phe, 10−5 M) caused an increase in active stress that was smaller in pregnant (4.2 ± 0.3) than virgin rats (5.1 ± 0.3 × 104 N/m2). IL-6 (1,000 pg/ml) caused enhancement of Phe contraction that was greater in pregnant (10.6 ± 0.7) than virgin rats (7.5 ± 0.4 × 104 N/m2). ACh and bradykinin caused relaxation of Phe contraction and increases in vascular nitrite production that were greater in pregnant than virgin rats. IL-6 caused reductions in ACh- and bradykinin-induced vascular relaxation and nitrite production that were more prominent in pregnant than virgin rats. Incubation of endothelium-intact strips in the presence of Nω-nitro-l-arginine methyl ester (10−4 M) to inhibit nitric oxide (NO) synthase, or 1H-[1,2,4]oxadiazolo[4,3]-quinoxalin-1-one (ODQ, 10−5 M) to inhibit cGMP production in smooth muscle, inhibited ACh-induced relaxation and enhanced Phe-induced stress in nontreated but to a lesser extent in IL-6-treated vessels, particularly those of pregnant rats. Removal of the endothelium enhanced Phe-induced stress in nontreated but not IL-6-treated vessels, particularly those of pregnant rats. In endothelium-denuded strips, relaxation of Phe contraction with sodium nitroprusside, an exogenous NO donor, was not different between nontreated and IL-6-treated vessels of virgin or pregnant rats. Thus IL-6 inhibits endothelium-dependent NO-cGMP-mediated relaxation and enhances contraction in systemic vessels of virgin and pregnant rats. The greater IL-6-induced inhibition of vascular relaxation and enhancement of contraction in systemic vessels of pregnant rats supports a direct role for IL-6 as one possible mediator of the increased vascular resistance associated with hypertension of pregnancy.
Olfaction: From Odorant Molecules to the Olfactory Cortex
Authors: Menini Anna , Lagostena Laura , Boccaccio Anna
Published: May 2004

How do we smell? Our knowledge of how odor information from the environment is perceived has greatly advanced since the discovery of ~1,000 genes for odorant receptors in the mammalian genome. From the combination of molecular-genetic, electrophysiological, and optical imaging studies a better understanding of how we smell is emerging.
Peroxisome Proliferator-Activated Receptors and Atherogenesis
Authors: Marx Nikolaus , Duez Hélène , Fruchart Jean-Charles , Staels Bart
Published: May 2004

A large body of data gathered over the past couple of years has identified the peroxisome proliferator-activated receptors (PPAR) α, γ, and β/δ as transcription factors exerting modulatory actions in vascular cells. PPARs, which belong to the nuclear receptor family of ligand-activated transcription factors, were originally described as gene regulators of various metabolic pathways. Although the PPARα, γ, and β/δ subtypes are ≈60% to 80% homologous in their ligand- and DNA-binding domains, significant differences in ligand and target gene specificities are observed. PPARα is activated by polyunsaturated fatty acids and oxidized derivatives and by lipid-modifying drugs of the fibrate family, including fenofibrate or gemfibrozil. PPARα controls expression of genes implicated in lipid metabolism. PPARγ, in contrast, is a key regulator of glucose homeostasis and adipogenesis. Ligands of PPARγ include naturally occurring FA derivatives, such as hydroxyoctadecadienoic acids (HODEs), prostaglandin derivatives such as 15-deoxyΔ
12,14
-prostaglandin J
2
, and glitazones, insulin-sensitizing drugs presently used to treat patients with type 2 diabetes. Ligands for PPARβ/δ are polyunsaturated fatty acids, prostaglandins, and synthetic compounds, some of which are presently in clinical development. PPARβ/δ stimulates fatty acid oxidation predominantly acting in muscle. All PPARs are expressed in vascular cells, where they exhibit antiinflammatory and antiatherogenic properties. In addition, studies in various animal models as well as clinical data suggest that PPARα and PPARγ activators can modulate atherogenesis in vivo. At present, no data are available relating to possible effects of PPARβ/δ agonists on atherogenesis. Given the widespread use of PPARα and PPARγ agonists in patients at high risk for cardiovascular disease, the understanding of their function in the vasculature is not only of basic interest but also has important clinical implications. This review will focus on the role of PPARs in the vasculature and summarize the present understanding of their effects on atherogenesis and its cardiovascular complications.
Scheherezade Goes West
Authors: Afzal-Khan Fawzia
Published: May 2004

Madmedea is an avatar of the fabled Scheherezade of the Arabian Nights, a response/challenge to Heiner Müller's texts, and more. “What could constitute an effective interruptive feminist performance to halt, reverse, and challenge the imperialist/patriarchal performances of globalized power and dominance in their postmodern capitalist permutations masquerading as a New World Order? In my performative identity as Muslim/South Asian/Other/Woman, how far can I really go (am permitted to go?) to jam the machinery, to interrupt business-as-usual?”
Challenging Nostalgia: Unveiling the Ghosts of Seattle's Nippon Kan
Authors: Yong Byron Au
Published: May 2004

The Nippon Kan, a theatre hall built by Seattle's Japanese immigrants, went dark when President Roosevelt signed Executive Order 9066 in 1942, removing Americans of Japanese descent from the West Coast. Au Yong's auto-ethnographic essay addresses how nostalgia and identity affect performances in the present, incorporating voiceovers, program notes, and the ruminations of a pianist to complicate his memories of Woman, Monkey, and Kabuki Joe, which premiered at the Nippon Kan. Winner of TDR's Student Essay Contest for 2003.
Combined Use of Erythropoietin and Granulocyte Colony-Stimulating Factor Does Not Decrease Blood Transfusion Requirements During Induction Therapy for High-Risk Neuroblastoma: A Randomized Controlled Trial
Authors: Wagner Lars M. , Billups Catherine A. , Furman Wayne L. , Rao Bhaskar N. , Santana Victor M.
Published: May 2004

Purpose

To evaluate the efficacy of recombinant erythropoietin (EPO) and granulocyte colony-stimulating factor (G-CSF) in reducing blood transfusion requirements and stimulating hematopoiesis in children with high-risk neuroblastoma.

Patients and Methods

Thirty-eight patients given six cycles of intensive induction chemotherapy for high-risk neuroblastoma were randomized to receive G-CSF (n = 20) or G-CSF + EPO (n = 18). Cytokines were given subcutaneously each day, starting 24 hours after each chemotherapy cycle and continuing until 48 hours before the start of the next cycle. The primary end point was the effect of EPO on total red cell transfusion requirements during induction therapy.

Results

Patients who received G-CSF + EPO had a higher red cell transfusion requirement (median, 161.0 mL/kg) than did those who received G-CSF alone (median, 106.6 mL/kg; P = .005). In addition, among patients given transfusions for hemoglobin ≤ 8 g/dL, those in the G-CSF + EPO group received more red cell transfusions than did those given G-CSF alone (median per patient, 10 v 8, respectively; P = .044). The two treatment groups had similar cumulative durations of neutropenia, incidences of febrile neutropenia, platelet transfusion requirements, and numbers of platelet transfusions; they also received induction chemotherapy for similar durations and had similar probabilities of progression-free survival and overall survival.

Conclusion

The addition of EPO to the G-CSF regimen provides no benefit for patients receiving intensive induction chemotherapy for high-risk neuroblastoma.
Phase I Trial of Weekly Docetaxel With Concurrent Three-Dimensional Conformal Radiation Therapy in the Treatment of Unfavorable Localized Adenocarcinoma of the Prostate
Authors: Kumar Parvesh , Perrotti Michael , Weiss Robert , Todd Mary , Goodin Susan , Cummings Kenneth , DiPaola Robert S.
Published: May 2004

Purpose

A phase I trial was conducted to determine the maximally tolerated dose (MTD) of concurrent weekly docetaxel and three-dimensional conformal radiation therapy (3-D CRT) in unfavorable localized adenocarcinoma of the prostate.

Patients and Methods

Patients with unfavorable localized adenocarcinoma of the prostate underwent daily 3-D CRT to a total dose of 70.2 Gy at 1.8 Gy/fraction and concurrent docetaxel given once a week for 8 to 9 weeks. The initial weekly docetaxel dose level was 5 mg/m2 and the docetaxel doses were escalated as follows: 8, 12, 16, 20, and 25 mg/m2.

Results

Between January 2000 and August 2002, 22 men completed the chemoradiation therapy protocol. The dose-limiting toxicity was grade 3 diarrhea, which occurred in the first two patients treated at the 25 mg/m2 docetaxel dose level. The MTD of weekly docetaxel was determined to be 20 mg/m2. The overall incidence of grade 2 diarrhea and grade 2 dysuria was 36% and 23%, respectively. Seven (32%) and 15 (68%) patients did not experience any diarrhea or dysuria, respectively. No neutropenia or thrombocytopenia was observed. One patient required intermittent urinary catherization 10 months postcompletion of therapy, which resolved without any surgical intervention. Seventeen patients remain in prostate-specific antigen remission. At a median follow-up interval of 8 months (range, 2 to 27 months), all patients are alive.

Conclusion

Concurrent weekly docetaxel in conjunction with 3-D CRT is well tolerated with acceptable toxicity. The MTD of weekly docetaxel was determined to be 20 mg/m2 with concurrent 3-D CRT.
International Assessment of the Quality of Clinical Practice Guidelines in Oncology Using the Appraisal of Guidelines and Research and Evaluation Instrument
Authors: Burgers J.S. , Fervers B. , Haugh M. , Brouwers M. , Browman G. , Philip T. , Cluzeau F.A.
Published: May 2004

Purpose

To describe the quality of oncology guidelines developed in different countries.

Methods

The Appraisal of Guidelines and Research and Evaluation (AGREE) Instrument was used to assess the quality of 100 guidelines (including 32 oncology guidelines) from 13 countries. The criteria of the instrument are grouped into six quality domains: scope and purpose, stakeholder involvement, rigor of development, clarity and presentation, applicability, and editorial independence.

Results

Oncology guidelines had significantly higher scores on rigor of development than nononcology guidelines (42.2% v 29.4%; P = .02). In particular, systematic methods to search for evidence were more often used (P = .01); the methods for formulating the recommendations were more clearly described (P = .02); and health benefits, risks, and side effects were more often considered in formulating the recommendations (P = .03). Although the standardized scores for the other domains were not significantly different, the oncology guidelines had significantly higher scores for items measuring inclusion of all relevant professional groups (P = .05), consideration of patient views (P = .04), and presentation of different options (P = .05). Only three organizations producing oncology guidelines had standardized scores more than 60% for more than three domains.

Conclusion

The quality of clinical practice guidelines (CPGs) is modest in general, but for certain domains, oncology guidelines seem to be of better quality than others. The experience of the organization may explain higher scores for some items. Research projects and training aimed at improving the quality of guidelines should be developed. The AGREE instrument could provide a basis for defining steps in a shared development approach to produce high-quality CPGs.
Failure Pattern and Factors Predictive of Local Failure in Rhabdomyosarcoma: A Report of Group III Patients on the Third Intergroup Rhabdomyosarcoma Study
Authors: Wharam Moody D. , Meza Jane , Anderson James , Breneman John C. , Donaldson Sarah S. , Fitzgerald Thomas J. , Michalski Jeff , Teot Lisa A. , Wiener Eugene S. , Meyer William H.
Published: May 2004

Purpose

To analyze patterns of failure and factors predictive of local treatment failure in children enrolled on the third Intergroup Rhabdomyosarcoma Study who had either biopsy only or subtotal resection of their primary tumor, had no distant metastases, and received radiation therapy for local control.

Patients and Methods

Treatment failure was categorized as local, regional nodal, or distant metastatic. The 5-year cumulative risk of failure was estimated for each category and factors predictive of local failure risk were determined using the Cox model and binary recursive partitioning.

Results

The estimated 5-year cumulative incidence rates by failure category were: total local (with or without concurrent regional or distant failure), 19%; total regional nodal, 2%; total distant, 11%; and death from toxicity or unknown recurrence type, 4%. Lymph node involvement at diagnosis was the single factor most predictive of increased total local failure risk (5-year cumulative incidence 32%) compared with children with negative nodes or unknown node status (16%). No significant effect on local failure risk was observed by total radiotherapy dose over the prescribed range of 41.4 Gy to 50.4 Gy. For all patients (N = 405), the estimated 5-year failure-free survival and overall survival were, respectively, 70% and 78%.

Conclusion

Local failure after radiotherapy for group III rhabdomyosarcoma patients is the predominant type of relapse. Involved lymph nodes at diagnosis predict a higher risk of local and distant treatment failure compared with patients whose lymph nodes are negative.
Telomere Length and Human Telomerase Reverse Transcriptase Expression As Markers for Progression and Prognosis of Colorectal Carcinoma
Authors: Gertler Ralf , Rosenberg Robert , Stricker Dominik , Friederichs Jan , Hoos Axel , Werner Martin , Ulm Kurt , Holzmann Bernhard , Nekarda Hjalmar , Siewert Joerg-Ruediger
Published: May 2004

Purpose

Maintenance of telomeres through reactivation of telomerase is a prerequisite for tumors to preserve their ability to proliferate. The purpose of this study was to evaluate telomere length and human telomerase reverse transcriptase (hTERT) expression as markers for progression and prognosis of colorectal carcinoma.

Patients and Methods

Telomere length and hTERT expression were analyzed in matched cancer and adjacent noncancer mucosa samples from 57 patients with R0-resected colorectal carcinoma. The median follow-up time was 76 months.

Results

Telomere length and hTERT expression correlated significantly in cancer tissues and adjacent mucosa samples (r = 0.52, P < .001; and r = 0.54, P < .001, respectively). Overall, cancer tissue had shorter telomeres than adjacent mucosa (P < .001). Only in noncancer tissue did telomere length decrease with age (r = 0.36; P < .01). Telomere length in cancer tissue was significantly correlated with tumor stage (P < .01), with longer telomeres in advanced tumors. Patients with ratios of telomere length in cancer to noncancer tissue greater than 0.90 had a significantly poorer overall survival compared with patients with smaller telomere length ratios (P < .002). In multivariate analysis, the telomere length ratio proved to be of independent prognostic value (P < .03).

Conclusion

Telomeres in colorectal carcinoma tissue were significantly shorter compared with adjacent normal mucosa as an indication for extensive cell proliferation. The correlation with tumor stage and patient survival suggest that hTERT-mediated telomere stabilization may be critical for progression and prognosis of colorectal carcinoma.
Palliative Care Inpatient Service in a Comprehensive Cancer Center: Clinical and Financial Outcomes
Authors: Elsayem Ahmed , Swint Kay , Fisch Michael J. , Palmer J. Lynn , Reddy Suresh , Walker Paul , Zhukovsky Donna , Knight Patti , Bruera Eduardo
Published: May 2004

Purpose

Inpatient palliative care units are unavailable in most cancer centers and tertiary hospitals. The purpose of this article is to review the outcomes of the first 344 admissions to the Palliative Care Inpatient Service (PCIS) at our comprehensive cancer center.

Patients and Methods

We retrospectively reviewed our computerized database for clinical and demographic information, length of stay, and hospital billing during the first year of the service's operation.

Results

Three hundred twenty patients were admitted during the study period. Their median age was 57 years. The main cancer diagnoses were thoracic or head and neck (44%), gastrointestinal (25%), and hematologic malignancy (8%). The main referral symptoms were pain (44%), nausea (41%), fatigue (39%), and dyspnea (38%). The median length of stay in the PCIS was 7 days (range, 1 to 58 days). Fifty-nine patients died while in the PCIS. However, the overall hospital mortality rate was not increased compared with that in the year before the establishment of the PCIS (3.58% v 3.59%). The mean reimbursement rate for all palliative care charges was approximately 57%, and the mean daily charges in the PCIS were 38% lower than the mean daily charges for the rest of the hospital. Symptom intensity data showed severe distress on admission and significant improvement in the main target symptoms. Most patients were discharged to a hospice.

Conclusion

The PCIS has been accepted in our tertiary cancer center on the basis of its clinical utility and financial viability.
Pegylated Arginine Deiminase Treatment of Patients With Unresectable Hepatocellular Carcinoma: Results From Phase I/II Studies
Authors: Izzo Francesco , Marra Paolo , Beneduce Gerardo , Castello Giuseppe , Vallone Paolo , De Rosa Vincenzo , Cremona Franco , Ensor C. Mark , Holtsberg Frederick W. , Bomalaski John S. , Clark Mike A. , Ng Chaan , Curley Steven A.
Published: May 2004

Purpose

Recently, we reported that a large number of human hepatocellular cancer (HCC) cell lines were auxotrophic for arginine. Here we report the results obtained with the amino acid–degrading enzyme arginine deiminase (ADI) conjugated to polyethylene glycol (ADI-SS PEG 20,000 mw) as a means of lowering plasma arginine to treat HCC. The study was a cohort dose-escalation phase I/II study.

Patients and Methods

Pharmacodynamic studies indicated an ADI-SS PEG 20,000 mw dose level of 160 U/m2 was sufficient to lower plasma arginine from a resting level of approximately 130 μmol/L to below the level of detection (< 2 μmol/L) for more than 7 days, a dose later defined as the optimal biologic dose. All patients were to receive three cycles at the optimum biologic dose.

Results

This therapy was well tolerated, even in patients who had no detectable plasma arginine for 3 continuous months of therapy. Of the 19 patients enrolled, two had a complete response, seven had a partial response, seven had stable disease, and three had progressive disease. The median survival for the 19 patients enrolled on this study was 410 days, with four patients still alive at present (> 680 days).

Conclusion

Elimination of all detectable plasma arginine in patients with HCC was well tolerated and seemed to be effective in the treatment of some patients with HCC. Further testing of ADI-SS PEG 20,000 mw in a larger population of individuals with HCC as well as other human tumors auxotrophic for arginine is warranted.
Motivational and Cultural Variations in Mortality Salience Effects: Contemplations on Terror Management Theory and Consumer Behavior
Authors: Maheswaran Durairaj , Agrawal Nidhi
Published: May 2004

Terror management theory provides a viable framework to examine the effects of mortality salience (MS) and related coping behaviors. We explore the utility of viewing MS effects from an information processing perspective and discuss the implications for understanding consumer behavior. We suggest that a better understanding of the motivational nature of MS and the underlying processes could provide additional insights on the persuasive impact of MS. We also anticipate effects of MS to differ across cultures and predict some novel outcomes. Finally, we outline several potential avenues for investigating MS effects in consumer domains such as branding and advertising.
Irrelevant Information and Mediated Intertemporal Choice
Authors: van Osselaer Stijn M.J. , Alba Joseph W. , Manchanda Puneet
Published: May 2004

Results from 4 experiments suggest that currencies such as loyalty‐program points are overvalued. Different allocations of the same quantity of points across the same number of purchases (e.g., 100 points for each first, 200 for each second, 300 for each third purchase vs. 200 for each first, second, and third purchase) yielded irrelevant trends and should have led participants to ignore loyalty points as a basis for choice. However, choices were influenced by points even when consumers were provided with other truly discriminating information (e.g., price) and the irrelevance of the loyalty points was readily discernable. This implies that irrelevant information can influence choice when other, easily justifiable bases for decisions are available and, therefore, that irrelevant information can function as more than a tie‐breaker. Other implications for research on irrelevant attributes, medium effects, intertemporal choice, and loyalty programs are discussed.
“If You Can't Dazzle Them with Brilliance, Baffle Them with Nonsense”: Extending the Impact of the Disrupt‐Then‐Reframe Technique of Social Influence
Authors: Fennis Bob M. , Das Enny H.H.J. , Pruyn Ad Th.H.
Published: May 2004

Three experiments extended earlier findings on the impact of the Disrupt‐Then‐Reframe (DTR) technique on compliance. This technique is comprised of a subtle, odd element in a typical scripted request, the “disruption,” followed by a persuasive phrase, the “reframing.” Based on the thought‐disruption hypothesis (Petty & Wegener, 1999), we argue that its impact is generalizable across situations and that disrupting a conventional sales script not only increases the impact of the new reframing, but also increases susceptibility to influence resulting from other (congruence‐based) persuasion techniques embedded in the influence setting. Three experiments provided support for our expectations. Specifically, the DTR technique reduced the extent of counter‐argumentation to a sales script and boosted the impact of two other persuasion techniques: the continued questions procedure and message‐goal congruence. The theoretical and practical implications of these findings are discussed.
Dogmas and controversies in the handling of nitrogenous wastes:Expression of arginase Type I and II genes in rainbow trout: influence of fasting on liver enzyme activity and mRNA levels in juveniles
Authors: Wright Patricia A. , Campbell Alisha , Morgan Robyn L. , Rosenberger Andrew G. , Murray Brent W.
Published: May 2004

Through analysis of a cDNA library and third-party annotation of available database sequences, we characterized the full-length coding regions of rainbow trout (Oncorhynchus mykiss) Type I, Onmy-ARG01, and Type II, Onmy-ARG02, arginase genes. Two partial related arginase sequences, Onmy-ARG01b and Onmy-ARG02b, and a full-length zebrafish arginase coding region (Danio rerio), Dare-ARG02, are also reported. Comparison of vertebrate arginase sequences shows that both Type I and Type II genes in bony fishes contain a mitochondrial targeting N-terminal domain. This suggests that the cytosolic Type I arginase found in ureotelic vertebrates arose in the common ancestor of amphibia and mammals. Onmy-ARG01 and Onmy-ARG02 mRNA was detected in liver,kidney, gill, intestine, red muscle and heart tissues. Onmy-ARG01 was expressed at a significantly higher level relative to Onmy-ARG02 in liver and red muscle tissue. To investigate whether there was differential regulation of Onmy-ARG01 and Onmy-ARG02, juvenile trout were fasted for 6 weeks and hepatic enzyme activities and mRNA levels were compared with those of fed control fish. There was a 3-fold increase in liver arginase activity and a 2-fold increase in Onmy-ARG02 mRNA levels but no change in Onmy-ARG01 mRNA levels in fasted fish relative to fed fish. These findings indicate that both types of arginase genes are present and expressed in rainbow trout and that the pattern of expression varies between tissues. The increase in liver arginase activity after a 6-week fast is due,in part, to an increase in the expression of Onmy-ARG02 mRNA levels.
The effects of surface diameter and incline on the hindlimb kinematics of an arboreal lizard (Anolis sagrei)
Authors: Spezzano Lawrence C. , Jayne Bruce C.
Published: May 2004

Arboreal animals often move in habitats with dense vegetation, narrow perches and variable inclines, but effects of arboreal habitat structure on locomotor function are poorly understood for most animals. Several species of Anolis lizards, which have served as a model group for relating locomotor performance to morphology, have decreased maximal sprinting speeds when perch diameter decreases. However, the effects of perch diameter on the limb movements of Anolis have not been previously studied. Hence, we quantified the hindlimb movements of Anolis sagrei, which naturally occurs on a wide variety of perch diameters and inclines. We analyzed similar speeds of steady locomotion for combinations of flat surfaces and round perches with diameters of 1, 3, 6 and 10 cm and inclines of 0° and uphill 45° and 90°. Diameter significantly affected more kinematic variables than incline, but many kinematic variables changed little with increases in diameter beyond 6 cm. As surface diameter increased, the limb posture of A. sagrei became progressively more sprawled. Significantly greater knee flexion during stance was important for locating the foot more medially during movement on narrow perches. Stride length increased and femur depression, femur retraction and long-axis femur rotation decreased significantly as the surface diameter increased. The low hip heights on the vertical incline and the narrowest perches suggest that bringing the center of mass closer to the locomotor surface is important in these circumstances for reducing the tendency to topple backwards or sideways. Most of the kinematic changes of A. sagrei with decreased perch diameter were opposite those correlated with increased speeds of locomotion for terrestrial lizards. The foot was most lateral to the hip during the swing phase and maximal lateral displacements decreased with decreased perch diameter. Consequently, the width required to accommodate limb movement also decreased as perch diameter decreased.
The effect of mycoplasmosis on carotenoid plumage coloration in male house finches
Authors: Hill Geoffrey E. , Farmer Kristy L. , Beck Michelle L.
Published: May 2004

Parasites are widely assumed to cause reduced expression of ornamental plumage coloration, but few experimental studies have tested this hypothesis. We captured young male house finches Carpodacus mexicanus in Alabama before fall molt and randomly divided them into two groups. One group was infected with the bacterial pathogen Mycoplasma gallicepticum (MG)and the other group was maintained free of MG infection. All birds were maintained through molt on a diet of seeds with tangerine juice added to their water as a source of β-cryptoxanthin, the natural precursor to the primary red carotenoid pigment in house finch plumage. All males grew drab plumage, but males with MG infection grew feathers that were significantly less red (more yellow), less saturated, and less bright than males that were not infected. MG targets upper respiratory and ocular tissue. Our observations show that a pathogen that does not directly disrupt carotenoid absorption or transportation can still have a significant effect on carotenoid utilization.
The sea urchin complement homologue, SpC3, functions as an opsonin
Authors: Clow Lori A. , Raftos David A. , Gross Paul S. , Smith L. Courtney
Published: May 2004

The purple sea urchin Strongylocentrotus purpuratus expresses a homologue of complement component C3 (SpC3), which acts as a humoral opsonin. Significantly increased phagocytic activity was evident when yeast target cells were opsonized after incubation with coelomic fluid containing SpC3. SpC3 could be detected on the surface of yeast, and phagocytic activity could be inhibited by an anti-SpC3 antibody. This indicates that SpC3 promotes phagocytosis by physically tagging target cells for ingestion. Confocal microscopy showed that opsonized yeast were phagocytosed by a single coelomocyte type (polygonal phagocytes), presumably because these cells express SpC3 receptors. Overall, these data indicate that SpC3 is a major humoral opsonin in S. purpuratus coelomic fluid.
Arrested development inXenopus laevistadpoles: how size constrains metamorphosis
Authors: Rot-Nikcevic Irena , Wassersug Richard J.
Published: May 2004

Xenopus laevis tadpoles that arrest development and remain as larvae for several years sometimes occur spontaneously in laboratory populations. These tadpoles cease development at an early hindlimb stage, but continue to grow and develop into grossly deformed giants. Giant tadpoles lack thyroid glands, and differ in morphology and behaviour from normal larvae. They are negatively buoyant, typically with small and partially solidified lungs, and have greatly enlarged fat bodies. Giant tadpoles have mature gonads with eggs and sperm, whereas normal tadpoles of the same stage have undifferentiated gonads. Larval reproduction has never been reported in anurans, but gonadal development decoupled from metamorphosis brings these giants the closest of any anurans to being truly neotenic. We discuss behavioural and morphological factors that may hinder both reproduction in giant Xenopus larvae and the evolution of neoteny in anurans in general. Experimental treatment with exogenous thyroid hormone induces some,but not complete, metamorphic changes in these giants. The limbs and head progress through metamorphosis; however, all tadpoles die at the stage when the tail would normally be resorbed. The disproportionate growth of tissues and organs in giant tadpoles may preclude complete metamorphosis, even under exogenous thyroid hormone induction.
Organic cation transport by Malpighian tubules ofDrosophila melanogaster: application of two novel electrophysiological methods
Authors: Rheault Mark R. , O'Donnell Michael J.
Published: May 2004

Transport of the prototypical organic cation tetraethylammonium (TEA) by the Malpighian tubules, ureters and gut of Drosophila melanogasterwas studied using two novel electrophysiological techniques. Both techniques exploited the high selectivity of the cation exchanger potassium tetra-p-chlorophenylborate for tetraalkylammonium compounds relative to inorganic cations such as K+. In the first technique, TEA fluxes were measured using a non-invasive self-referencing TEA-selective microelectrode positioned in the unstirred layer near the surface of each tissue. TEA fluxes from bath to lumen as large as 6 pmol cm–2s–1 were measured across the lower (reabsorptive) segment of the Malpighian tubule and the ureter bathed in saline containing 0.1 mmol l–1 TEA. Corresponding bath-to-lumen fluxes across the secretory main segment of the Malpighian tubule and the posterior midgut were∼1 pmol cm–2 s–1. TEA transport by the lower Malpighian tubule was enhanced by hyperpolarization of the basolateral membrane potential and was inhibited by cimetidine, quinidine, vinblastine and verapamil. In the second technique, TEA concentration was measured using a TEA-selective microelectrode positioned in droplets of fluid secreted by Malpighian tubules set up in saline droplets under oil in a Ramsay assay. Results from the Ramsay assay confirmed the dominant role of the lower Malpighian tubule in net transepithelial secretion of TEA and inhibition of TEA transport by cimetidine. Kinetic parameters (Jmax and Kt) were determined using both approaches.
Dynamic Characteristics of a Combined Bellows and Liner Flexible Joint
Authors: Englund T L , Wall J E , Ahlin K A , Broman G I
Published: May 2004

A bellows combined with an inside liner and an outside braid is commonly used as a flexible joint in automobile exhaust systems to reduce transmission of engine movements to the exhaust system. It greatly influences the dynamics of the complete system. Understanding of its dynamic characteristics and a modelling method that facilitates systems simulation are therefore desired. This has been obtained in earlier works for the bellows itself. In this work an approach to the modelling of the combined bellows and liner joint is suggested and experimentally verified. Simulations and measurements show that the liner adds significant non-linearity and makes the characteristics of the joint complex. Results are presented for the axial and the bending load cases. In torsion, influence of the liner is negligible. Peak responses are significantly reduced when the excitation level approximately corresponds to the friction limit of the liner. The complexity of the combined bellows and liner joint is important to know of and consider in exhaust system design and proves the necessity of including a model of the liner in the theoretical joint model when this type of liner is present in the real joint to be simulated.
Development of a neural network model of an advanced, turbocharged diesel engine for use in vehicle-level optimization studies
Authors: Delagrammatikas G J , Assanis D N
Published: May 2004

The following work documents the development of an artificial neural network (ANN) model of an advanced, turbocharged diesel engine, and its implementation within an overall vehicle simulation. The purpose of this research was to create a model that would help drastically reduce in-vehicle engine design cycle time, improve numerical robustness and maintain the predictive capability of its physically based counterpart. Ease of integration within an optimization framework for preliminary investigations of engine designs was also a significant need. A design of experiments (DOE) was first used to sample the engine' feasible design domain. The high-fidelity model calculated engine responses at these DOE designs; the DOE inputs and engine model responses were subsequently used to train a radial basis function ANN. A typical, vehicle-level optimization study is presented which compares results and time requirements of the ANN and high-fidelity models. Critical issues in the development of an ANN engine model are detailed and generic guidelines are presented to expedite the implementation of this surrogate modelling technique to other complex subsystems and components.