bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Neurotransplants and BDNF on the Survival and Regeneration of Injured Adult Spinal Motoneurons
Authors: Novikova Lioudmila , Novikov Lev , Kellerth Jan‐Olof
Published: April 2006

We compared the effects of peripheral nerve grafts, embryonic spinal cord transplants and brain‐derived neurotrophic factor (BDNF) on the survival and axon regeneration of adult rat spinal motor neurons undergoing retrograde degeneration after ventral root avulsion. Following implantation into the dorsolateral funiculus of the injured spinal cord segment, neither a peripheral nerve graft nor a combination of peripheral nerve graft with embryonic spinal cord transplant could prevent the retrograde motor neuron degeneration induced by ventral root avulsion. However, intrathecal infusion of BDNF promoted long‐term survival of the lesioned motor neurons and induced abundant motor axon regeneration from the avulsion zone along the spinal cord surface towards the BDNF source. A combination of ventral root reconstitution and BDNF treatment might therefore be a promising means for the support of both motor neuron survival and guided motor axon regeneration after ventral root lesions.
Peripheral Noxious Stimulation Induces CREM Expression in Dorsal Horn: Involvement of Glutamate
Authors: Naranjo Jose R. , Mellström Britt , Carrion Angel M. , Lucas Jose J. , Foulkes Nicholas S. , Sassone‐Corsi Paolo
Published: April 2006

Peripheral noxious stimulation is known to trigger signalling cascades in neurons of the spinal cord. The response to pain and stress at the level of gene expression involves transcriptional activation of several cyclic AMP responsive genes. Here, we show induction of the CREM (cyclic‐AMP responsive element modulator) gene in distinct subpopulations of spinal cord neurons upon thermal noxious stimulation. The addition of forskolin or glutamate to cultured spinal cord neurons results in the induction of the CREM isoform, ICER (Inducible cyclic‐ AMP Early Repressor), a powerful repressor of CAMP‐induced transcription. Overexpression of ICER in cultured spinal cord neurons results in the repression of the c‐fos and c‐jun promoters induced by forskolin and glutamate. On this basis, we postulate that early activation of ICER in spinal cord participates in the attenuation of early gene induction following noxious stimulation.
Mother Nature's Bag of Tricks is Small
Authors: Kimble Gregory A.
Published: April 2006

There is greater unity in psychology than our internal squabbles might suggest because Mother Nature uses the same tricks in many contexts. There are fundamental principles that apply widely in psychology and have parallels in biology and physics. Behavior is a function of potentials that become manifest when the strenght of instigation to action exceeds a threshold. Thresholds result from exciting and inhibiting tendencies that are instigated along with a response of interest. Adaptive behavior is a blend of just two possibilities available to organisms, changing themselves to accommodate an unyielding environment or changing the world to meet their needs.
Serial vs. Parallel Processing: Sometimes They Look like Tweedledum and Tweedledee but they can (and Should) be Distinguished
Authors: Townsend James T.
Published: April 2006

A number of important models of information processing depend on whether processing is serial or parallel. However, many of the studies purporting to settle the case use weak experimental paradigms or results to draw conclusions. A brief history of the issue is given along with examples from the literature. Then a number of promising methods are presented from a variety of sources with some discussion of their potential. A brief discussion of the topic with regard to overall issues of model testing and applications concludes the paper.
Phonological Similarity, Pronunciation Rate, and Memory Span
Authors: Schweickert Richard , Guentert Lawrence , Hersberger Lora
Published: April 2006

Memory span is smaller for (a) items taking longer to pronounce and (b) phonologically more similar items. We investigated the relation between the two effects. Chase (1977) found that phonologically similar items were pronounced more slowly than dissimilar ones in a pronunciation task. A pronunciation rate difference in immediate recall could explain the phonological similarity effect as a special case of the word-length effect. Instead, the study found that pronunciation rates were equal. In the equation s = rt, span equals pronunciation rate times trace duration, word-length affects r while phonological similarity affects t. The two effects are shown to be complementary.
Enhancing Human Performance: An Evaluation of “New Age” Techniques Considered by the U.S. Army
Authors: Swets John A. , Bjork Robert A.
Published: April 2006

Unconventional techniques considered by the United States Army for enhancing human performance were reviewed during a two-year study by a committee of the National Research Council. Little or no scientific evidence was found to support the effectiveness of several, including neurolinguistic programming in interpersonal influence and such paranormal techniques as remote viewing and psychokinesis. Mixed results were seen to characterize other techniques, for example, group-cohesion procedures. Further study was suggested for a few, including mental practice of motor skills. Guidelines requested of the committee for future army evaluation of enhancement techniques stressed the need for, and the conduct of, both laboratory and field research. The committee recommended further consideration of mainstream research in the behavioral sciences as a basis for effective performance enhancements.
The Prenatal Origins of Behavioral Organization
Authors: Smotherman William P. , Robinson Scott R.
Published: April 2006

Recognition that organisms have a developmental history, exhibit behavior that is uniquely suited to or constrained by features of their immediate environment, and adapt to new environments is central to current psychobiological thought. Unfortunately, these concepts have in the past been restricted largely to the study of postnatal behavioral development. However, recent extension of these concepts to the fetus as an active and interactive organism that resides within a specialized, intrauterine niche is proving to be a profitable approach toward understanding the origins of behavioral organization during development.
Attractive Faces Are Only Average
Authors: Langlois Judith H. , Roggman Lori A.
Published: April 2006

Scientists and philosophers have searched for centuries for a parsimonious answer to the question of what constitutes beauty. We approached this problem from both an evolutionary and information-processing rationale and predicted that faces representing the average value of the population would be consistently judged as attractive. To evaluate this hypothesis, we digitized samples of male and female faces, mathematically averaged them, and had adults judge the attractiveness of both the individual faces and the computer-generated composite images. Both male (three samples) and female (three samples) composite faces were judged as more attractive than almost all the individual faces comprising the composites. A strong linear trend also revealed that the composite faces became more attractive as more faces were entered. These data showing that attractive faces are only average are consistent with evolutionary pressures that favor characteristics close to the mean of the population and with cognitive processes that favor prototypical category members.
Genetic and Environmental Influences on Religious Interests, Attitudes, and Values: A Study of Twins Reared Apart and Together
Authors: Waller Niels G. , Kojetin Brian A. , Bouchard Thomas J. , Lykken David T. , Tellegen Auke
Published: April 2006

The role of genetic and environmental factors in the expression of religious interests, attitudes, and values was examined using data from adult twins reared apart and adult twins reared together. The Religious Values scale of the Allport-Vernon-Lindzey Study of Values, a Religious Interest scale from the Strong Campbell Interest Inventory, the Wiggins Religious Fundamentalism scale from the MMPI, a Leisure Time Religious Interest scale, and a second measure of Occupational Religious Interest were administered to 53 identical and 31 fraternal twin pairs who had been reared apart. The Leisure Time Religious Interest Scale and the second measure of Occupational Religious Interest were also administered to 458 identical and 363 fraternal twin pairs who had been reared together. Biometric model fitting indicated that approximately 50% of the observed variance of all five measures is genetically influenced.
Explanatory Style as a Mechanism of Disappointing Athletic Performance
Authors: Seligman Martin E.P. , Nolen-Hoeksema Susan , Thornton Nort , Thornton Karen Moe
Published: April 2006

Two university varsity swimming teams took the Attributional Style Questionnaire (ASQ) at the start of the season. Swimmers with a pessimistic explanatory style went on to show more unexpected poor performances during competition than optimistic swimmers. We then tested the purported mechanism of this effect by experimentally simulating defeat, giving each swimmer falsely negative times. Performance deteriorated for those swimmers with a pessimistic explanatory style for bad events on their next swim, whereas performance for those swimmers with an optimistic style did not.
A Search for Principles in Principles of Psychology
Authors: Kimble Gregory A.
Published: April 2006

Principles of Psychology was published as an introductory textbook, with the contemporary virtue of having chapters that “can be assigned in any order.” It is a compendium of speculation, with very few connecting threads to tie materials together. This article reports one psychologist's travels through the Principles, in search of latent organizing structure, using as a guidebook the methodological and substantive content of two recent articles (Kimble, 1989, 1990a). The journey had its low and high points: The methodology encountered was hardly worth the trip. The exciting moments were the views of correspondences between James’ insights and what we know today.
Attention
Authors: LaBerge David L.
Published: April 2006

A retrospective survey of attention research from 1990 back to 1890 gives us, not the uncovering of startlingly new principles of attention, but rather the refinement in both conceptualization and laboratory measurement of the ideas set forth vividly by William James. Were he a witness to our times, he would undoubtedly applaud the renaissance of attention over the past three decades, and he would surely exhibit as much interest in the findings emerging from neuroscience laboratories as he would in the findings emerging from psychological laboratories.
Defining the Standard of Proof in Jury Instructions
Authors: Kagehiro Dorothy K.
Published: April 2006

Research on juror comprehension is reviewed with special attention to recent studies comparing types of definitions of three levels of the standard of proof (preponderance of the evidence, clear and convincing evidence, and beyond a reasonable doubt). Quantified definitions, (in which the standard of proof was expressed in probability terms, and combined quantified and legal definitions had their intended effect; verdicts favoring the plaintiffs decreased in number as the standard of proof became stricter. Nonquantified definitions did not achieve their intended effect on verdicts. The greater effectiveness of quantified definitions in communicating certainty levels precisely and concisely is attributed to the implicit context provided by their positions on an interval scale with known endpoints (i.e., 0-100%).
Behavior, Reinforcement and Utility
Authors: Herrnstein R.J.
Published: April 2006

The standard economic assumption about human behavior is that it optimizes overall utility. But in many controlled experiments on behavioral allocation, it has been found that organisms allocate their behavior so as to earn equal average rates of reinforcement from all alternatives. Equalizing average rates of reinforcement is a principle of allocation that generically violates the assumption of optimality.
Rational versus Plausible Accounting Equivalences in Preference Judgments
Authors: Luce R. Duncan
Published: April 2006

Subjective expected utility (SEU) embodies four distinct principles of rational behavior. Although all have been called into some question empirically, the least plausible and least studied is the property that formally equivalent gambles are treated as indifferent in preference. The paper describes some results that arise when this property is sharply weakened and to some degree replaced by alternative rational and not-so-rational-assumptions. The resulting utility representations, like SEU, are weighted averages of the utilities of consequences, but with the weights dependent on more than the underlying chance event. In rank-dependent cases, which arise from a restricted assumption about formally equivalent gambles, the weights depend on the rank position of the corresponding consequence. In rank- and sign-dependent models, they depend both on the rank position of the consequence associated to the event and on whether it is a gain or a loss. The theory giving rise to the latter involves an additional primitive, namely, joint receipt of gambles, in terms of which new rational and irrational assumptions are invoked. The result generalizes prospect theory to gambles with more than a single gain and a single loss.
Work Motivation and Satisfaction: Light at the End of the Tunnel
Authors: Locke Edwin A. , Latham Gary P.
Published: April 2006

After decades of research it is now possible to offer a coherent, data-based theory of work motivation and job satisfaction. The present model combines aspects of the following theories: goal setting, expectancy, social-cognitive, attribution, job characteristics, equity, and turnover-commitment. The resulting model is called the high performance cycle. It begins with organizational members being faced with high challenge or difficult goals. If high challenge is accompanied by high expectancy of success or self-efficacy, high performance results, given that there is: commitment to the goals, feedback, adequate ability, and low situational constraints. High performance is achieved through four mechanisms, direction of attention and action, effort, persistence, and the development of task strategies and plans. High performance, if rewarding, leads to job satisfaction, which in turn facilitates commitment to the organization and its goals. The model has implications for leadership, self-management, and education.
Changes in Memory for Stimulus Attributes: Implications for Tests of Morphine Tolerance
Authors: Feinberg Geoffrey , Riccio David C.
Published: April 2006

One major class of evidence indicating that associative processes contribute significantly to the development of morphine tolerance is based on the context specificity of the phenomenon: Changing the stimulus context correlated with drug administration diminishes tolerance. If this outcome is analogous to stimulus generalization decrement in traditional learning studies, then the flattening of generalization gradients over time may modulate the traditional test for tolerance. Accordingly, the effect of retention interval on context specificity of tolerance in rats was investigated. A hot-plate pain sensitivity test indicated that a context shift disrupted tolerance after a short, but not a long, retention interval. Methodological implications for assessment of learning processes in tolerance are noted.
Discovery of Reliable Attitude Change Persistence Resulting from a Transmitter Tuning Set
Authors: Boninger David S. , Brock Timothy C. , Cook Thomas D. , Gruder Charles L. , Romer Daniel
Published: April 2006

Support was found for the hypothesis that recipients of persuasive messages who are set to transmit the contents to others will exhibit attitude change that persists over time. In four studies, 208 students and 300 nonstudent adults were given either a transmitter set or a control set (a set to receive more information or no set instructions) prior to reading a persuasive message. Transmitters consistently exhibited more attitude change persistence at delays ranging from two to five months, across different populations, and for attitude issues evoking varying degrees of initial agreement. The practical implications for public health and education are discussed.
Innateness, Experience, and Music Perception
Authors: Lynch Michael P. , Eilers Rebecca E. , Oller D. Kimbrough , Urbano Richard C.
Published: April 2006

Musical acculturation from infancy to adulthood was studied by testing the abilities of Western 6-month-olds and adults to notice mistunings in melodies based on native Western major, native Western minor, and non-native Javanese pelog scales. Results indicated that infants were similarly able to perceive native and non-native scales. Adults, however, were generally better perceivers of native than non-native scales. These findings suggest that infants are born with an equipotentiality for the perception of scales from a variety of cultures and that subsequent culturally specific experience substantially influences music perception.
Why do People Gamble and Keep Gambling despite Heavy Losses?
Authors: Rachlin Howard
Published: April 2006

If a long series of gambles is subjectively structured into units each consisting of a string of consecutive losses followed by a win, positive valued strings will be short and negative valued strings will be long. Long negative strings will be temporally discounted more than short positive strings, increasing the gamble's subjective value. People, therefore, may gamble because even games of objectively negative expected value may be subjectively positive. People may keep gambling despite heavy losses because reduction of degree of discounting and expansion of the behavioral unit, characteristics of selfcontrol in other areas, fail to significantly decrease a gamble's subjective value.
Implicit and Explicit Memory following Surgical Anesthesia
Authors: Kihlstrom John F. , Schacter Daniel L. , Cork Randall C. , Hurt Catherine A. , Behr Steven E.
Published: April 2006

Paired associates were presented to 25 surgical patients following the induction of anesthesia by thiopental, vecuronium, and isoflurane. Postoperative testing (immediately or after two weeks) showed no free recall for the list; nor was there significant cued recall or recognition, compared to a matched control list. However, a free-association task showed a significant priming effect on both immediate and delayed trials. At least under some conditions, adequate surgical anesthesia appears to abolish explicit, but not implicit, memory for intraoperative events.
Endogenous Opioids Interfere with Pavlovian Second-Order Fear Conditioning
Authors: Cicala George A. , Azorlosa Julian L. , Estall Lorna B. , Grant Steven J.
Published: April 2006

Second-order classical (Pavlovian) aversive conditioning was used to determine whether endogenous opiates play a role in the acquisition of associative learning. Second-order conditioning avoids confounding drug effects on associative learning with altered responsiveness to unconditioned stimuli (e.g., hyperalgesia). Administration of the prototypical opiate antagonist naloxone (2.0 mg/kg) prior to the second-order training session specifically facilitated associative learning as indicated by greater lick suppression over 3 days of testing. This result suggests that endogenous opiates retard the acquisition of associative learning, which complements previous studies demonstrating an opioid attenuation of memory consolidation.
Letters to the Editor
Authors: Webb Wilse B.
Published: April 2006

Wilse B. Webb, Robert Rosenthal, and Joseph Yeager comment on “New Age” Techniques, discussed by John A. Swets and Robert A. Bjork in PS 1(2), 1990, pp. 85–96.
The Sympathetic Magical Law of Similarity, Nominal Realism and Neglect of Negatives in Response to Negative Labels
Authors: Rozin Paul , Markwith Maureen , Ross Bonnie
Published: April 2006

In accord with both the sympathetic magical law of similarity and the principle of nominal realism, previous research has shown that American adults have difficulty in ignoring a label indicating toxicity on a food, even though they know the label is false. This study confirms the finding, and shows that there is some reluctance to choose or consume a food entity if it is labelled explicitly as being nontoxic (a label of not sodium cyanide or not poison). Hence this type of magical thinking seems to ignore negatives.
Nuclear morphometry in columnar cell lesions of the breast: is it useful?
Authors: Lim C N , Ho B C S , Bay B H , Yip G , Tan P H
Published: April 2006

Aims:To evaluate the nuclear morphometric features of breast columnar cell lesions (CCLs) observed on mammotome core biopsies, to determine if there are significant measurable differences between those with atypia and those without. Correlation with follow-up open excision specimens was made.

Methods:Mammotome core biopsies performed on patients that contained CCLs were derived from the departmental case files. Histological material was reviewed and foci of CCLs demarcated for nuclear morphometric assessment, which was accomplished using an imaging system. Nuclear parameters studied were nuclear area and perimeter, circularity factor and feret’s diameter. Statistical analysis used the GraphPad Prism software, with p<0.05 indicating significance.

Results:On examination of core biopsies of 40 patients with CCLs, 8 lesions were benign, 4 showed atypical lobular hyperplasia, 8 showed CCLs with nuclear atypia, 19 disclosed atypical ductal hyperplasia (ADH) and 1 showed ductal carcinoma in situ (DCIS). The nuclear area, perimeter and feret’s diameter of CCLs with atypia were significantly greater than those without (p = 0.04, 0.03 and 0.019, respectively), whereas no difference was observed in the circularity factor. Follow-up open excision biopsy specimens in 24 patients showed upgrading to DCIS in 40% of cases diagnosed initially with ADH on core biopsy compared with 20% of CCLs with atypia.

Conclusions:Nuclear morphometry in CCLs confirms nuclear size as the key parameter in the assessment of nuclear atypia. Whether it can be potentially used as an adjunctive tool depends on the establishment of appropriate cut-offs.
High prevalence of isolated tumour cells in regional lymph nodes from pN0 colorectal cancer
Authors: Mescoli C , Rugge M , Pucciarelli S , Russo V M , Pennelli G , Guido M , Nitti D
Published: April 2006

Background:The prevalence of isolated tumour cells (ITCs) in regional lymph nodes from colorectal cancer (CRC) is controversial and has never been prospectively assessed in large groups of consecutive patients. pN0 early-relapsing CRC can be explained by lymph node-ITC.

Aim:: To assess the prevalence of ITCs in regional lymph nodes from 309 consecutive patients with pN0M0 (pathological (p)-tumour-node-metastasis (TNM) staging system) CRCs.

Patients and methods:ITCs were assessed by immunohistochemistry (MNF116 monoclonal antibody (1:100); Dako, Glostrup, Denmark) in two serial histological sections obtained from 5016 mesenteric lymph nodes from 309 patients with pN0 CRCs (mean number of lymph nodes per patient = 16.2; p-TNM stage 0, n = 25; p-TNM stage I, n = 123; and p-TNM stage II (A+B), n = 161). Tumour histology, vascular cancer invasion and pathological stage were also recorded.

Results:ITCs were detected in the regional lymph nodes of 156 of 309 (50.5%) patients with CRC, mostly in nodes located within 3 cm from the neoplasia. ITC status correlated with (a) tumour p-TNM stage (Pearson’s χ2: p<0; ordered logistic regression: odds ratio (OR) = 4.6; 95% confidence interval (CI) = 2.88 to 7.33; p<0) and (b) pT value (Pearson’s χ2: p = 0; ordered logistic regression: OR = 4.9; 95% CI = 3.1 to 7.7; p<0). By multivariate analysis, including p-TNM stage, vascular invasion and ITC status, both stage (OR = 5.1; 95% CI = 2.9 to 8.9; p<0) and vascular invasion (OR = 4.2; 95% CI = 1.94 to 8.98; p<0) were found to be independent variables associated with ITC+ lymph nodes.

Conclusion:More than 50% of pN0-CRC patients have ITCs in the mesenteric lymph nodes. ITC status is significantly correlated with cancer stage and vascular cancer invasion. The clinicopathological effect of ITC remains to be prospectively evaluated.
Effect of a selective chloride channel activator, lubiprostone, on gastrointestinal transit, gastric sensory, and motor functions in healthy volunteers
Authors: Camilleri Michael , Bharucha Adil E. , Ueno Ryuji , Burton Duane , Thomforde George M. , Baxter Kari , McKinzie Sanna , Zinsmeister Alan R.
Published: April 2006

Chloride channels modulate gastrointestinal neuromuscular functions in vitro. Lubiprostone, a selective type 2 chloride channel (ClC-2) activator, induces intestinal secretion and has been shown to relieve constipation in clinical trials; however, the effects of lubiprostone on gastric function and whole gut transit in humans are unclear. Our aim was to compare the effects of the selective ClC-2 activator lubiprostone on maximum tolerated volume (MTV) of a meal, postprandial symptoms, gastric volumes, and gastrointestinal and colonic transit in humans. We performed a randomized, parallel-group, double-blind, placebo-controlled study evaluating the effects of lubiprostone (24 μg bid) in 30 healthy volunteers. Validated methods were used: scintigraphic gastrointestinal and colonic transit, SPECT to measure gastric volumes, and the nutrient drink (“satiation”) test to measure MTV and postprandial symptoms. Lubiprostone accelerated small bowel and colonic transit, increased fasting gastric volume, and retarded gastric emptying. MTV values were reduced compared with placebo; however, the MTV was within the normal range for healthy adults in 13 of 14 participants, and there was no significant change compared with baseline measurements. Lubiprostone had no significant effect on postprandial gastric volume or aggregate symptoms but did decrease fullness 30 min after the fully satiating meal. Thus the ClC-2 activator lubiprostone accelerates small intestinal and colonic transit, which confers potential in the treatment of constipation.
Cytokines produced by bone marrow cells can contribute to functional improvement of the infarcted heart by protecting cardiomyocytes from ischemic injury
Authors: Takahashi Masaya , Li Tao-Sheng , Suzuki Ryo , Kobayashi Toshiro , Ito Hiroshi , Ikeda Yasuhiro , Matsuzaki Masunori , Hamano Kimikazu
Published: April 2006

It is well known that the implantation of bone marrow mononuclear cells (BM-MNCs) into ischemic hearts can induce angiogenesis and improve cardiac function after myocardial infarction, but the precise mechanisms of these actions are unclear. We hypothesize that the cytokines produced by BM-MNCs play a key role in this cell-based therapy. BM-MNCs from rats were cultured under normoxic or hypoxic (1% O2) conditions for 24 h, and then supernatants were collected for study. ELISA and Western blotting analysis showed that various cytokines, including VEGF, IL-1β, PDGF, and IGF-1, were produced from BM-MNCs, some of which were enhanced significantly under hypoxia stimulation. When compared with a control blank medium, the supernatants of BM-MNCs cultured under normoxic or hypoxic conditions inhibited apoptosis significantly and preserved the contractile capacity of isolated adult rat cardiomyocytes in vitro ( P < 0.05). Using a rat model of acute myocardial infarction, we injected the supernatants of BM-MNCs or control medium intramyocardially on day 0 and then intraperitoneally on days 2, 4, and 6 after infarction. When compared with the control medium, the supernatants of BM-MNCs cultured under both normoxic or hypoxic conditions increased the microvessel density and decreased the fibrotic area in the infarcted myocardium significantly, contributing to remarkable improvement in cardiac function. Various cytokines were produced by BM-MNCs, and these cytokines contributed to functional improvement of the infarcted heart by directly preserving the contractile capacity of the myocardium, inhibiting apoptosis of cardiomyocytes, and inducing therapeutic angiogenesis of the infarcted heart.
A novel strategy for increasing wall thickness of coronary venules prior to retroperfusion
Authors: Choy Jenny Susana , Kassab Ghassan S.
Published: April 2006

The sudden exposure of veins to arterial pressures during coronary venous retroperfusion may cause rupture of small venules. Our rationale is to first occlude the coronary vein, which will cause an increase in pressure intermediate to arterial and venous values, and hence lead to remodeling and increased wall thickness of the veins prior to retroperfusion. To accomplish this objective, five pigs were subjected to left anterior descending (LAD) vein ligation while six pigs served as sham. Myocardial tissue samples were obtained from the area adjacent to the LAD vein at four transmural locations of the left ventricular free wall: epicardial surface, subepicardium, midmyocardium, and endocardium. Arterioles and venules from the experimental and sham control groups were photographed, and the following measurements were made: inner and outer circumferences, inner and outer areas, major and minor diameters, and intima-media thickness. Each vessel was categorized in four different orders according to lumen diameter. Our results show that intima-media thickness was larger in the experimental group in all four regions of the heart and in all four orders of the vessels, although venules from the epicardial region showed the largest increase in thickness. The intima-media thickness-to-radius ratio was also larger in the experimental group and decreased from epicardial to endocardial region of the heart and from order 1 to order 4 of the vessels. The present study provides a rationale for the development of coronary retroperfusion strategy that avoids vessel rupture and hemorrhage in the postcapillary venules.
Role of superoxide and angiotensin II suppression in salt-induced changes in endothelial Ca2+signaling and NO production in rat aorta
Authors: Zhu Jiaxuan , Drenjancevic-Peric Ines , McEwen Scott , Friesema Jill , Schulta Danielle , Yu Ming , Roman Richard J. , Lombard Julian H.
Published: April 2006

Male Sprague-Dawley rats were maintained on a low-salt (LS) diet (0.4% NaCl) or changed to a high-salt (HS) diet (4% NaCl) for 3 days. Increases in intracellular Ca2+([Ca2+]i) in response to methacholine (10 μM) and histamine (10 μM) were significantly attenuated in aortic endothelial cells from rats fed a HS diet, whereas thapsigargin (10 μM)-induced increases in [Ca2+]iwere unaffected. Methacholine-induced nitric oxide (NO) production was eliminated in endothelial cells of aortas from rats fed a HS diet. Low-dose ANG II infusion (5 ng·kg−1·min−1iv) for 3 days prevented impaired [Ca2+]isignaling response to methacholine and histamine and restored methacholine-induced NO production in aortas from rats on a HS diet. Adding Tempol (500 μM) to the tissue bath to scavenge superoxide anions increased NO release and caused Nω-nitro-l-arginine methyl ester-sensitive vascular relaxation in aortas from rats fed a HS diet but had no effect on methacholine-induced Ca2+responses. Chronic treatment with Tempol (1 mM) in the drinking water restored NO release, augmented vessel relaxation, and increased methacholine-induced Ca2+responses significantly in aortas from rats on a HS diet but not in aortas from rats on a LS diet. These findings suggest that 1) agonist-induced Ca2+responses and NO levels are reduced in aortas of rats on a HS diet; 2) increased vascular superoxide levels contribute to NO destruction, and, eventually, to impaired Ca2+signaling in the vascular endothelial cells; and 3) reduced circulating ANG II levels during elevated dietary salt lead to elevated superoxide levels, impaired endothelial Ca2+signaling, and reduced NO production in the endothelium.
Effects of dexamethasone andl-canavanine on the intracellular calcium-contraction relation of the rat tail artery during septic shock
Authors: Mansart Arnaud , Bollaert Pierre-Edouard , Giummelly Philippe , Capdeville-Atkinson Christine , Atkinson Jeffrey
Published: April 2006

The intracellular mechanism by which sepsis lowers vascular reactivity and the subsequent reversal by dexamethasone or nitric oxide synthase (NOS) inhibitors remain unclear. We measured the sensitivity of contraction of the rat tail artery to intracellular Ca2+in a model of polymicrobial septic shock. At 22 h after cecal ligation and puncture (CLP), rats were treated with an anti-inflammatory glucocorticoid (dexamethasone, 1 mg/kg ip), an inducible NOS inhibitor (l-canavanine, 100 mg/kg ip), or saline. At 24 h after CLP, endothelium-denuded, perfused segments of tail artery were loaded with the intracellular Ca2+-sensitive dye fura 2 in vitro. Intracellular Ca2+concentration and perfusion pressure were measured simultaneously. The rightward shift of the perfusion pressure-intracellular Ca2+mobilization curve after norepinephrine stimulation subsequent to CLP indicates decreased intracellular Ca2+sensitivity of contraction. The relation was restored by dexamethasone (which also restored in vivo blood pressure and flow), but not by l-canavanine (which restored perfusion pressure by further mobilization of intracellular Ca2+). We conclude that CLP lowers vasomotion by lowering intracellular Ca2+sensitivity, which can be restored with glucocorticoid treatment. The involvement of inducible NOS does not solely account for the sepsis-induced reduction in Ca2+sensitivity of contraction.
KCachannel insensitivity to Ca2+sparks underlies fractional uncoupling in newborn cerebral artery smooth muscle cells
Authors: Li Anlong , Adebiyi Adebowale , Leffler Charles W. , Jaggar Jonathan H.
Published: April 2006

In smooth muscle cells, localized intracellular Ca2+transients, termed “Ca2+sparks,” activate several large-conductance Ca2+-activated K+(KCa) channels, resulting in a transient KCacurrent. In some smooth muscle cell types, a significant proportion of Ca2+sparks do not activate KCachannels. The goal of this study was to explore mechanisms that underlie fractional Ca2+spark-KCachannel coupling. We investigated whether membrane depolarization or ryanodine-sensitive Ca2+release (RyR) channel activation modulates coupling in newborn (1- to 3-day-old) porcine cerebral artery myocytes. At steady membrane potentials of −40, 0, and +40 mV, mean transient KCacurrent frequency was ∼0.18, 0.43, and 0.26 Hz and KCachannel activity [number of KCachannels activated by Ca2+sparks × open probability of KCachannels at peak of Ca2+sparks ( NPo)] at the transient KCacurrent peak was ∼4, 12, and 24, respectively. Depolarization between −40 and +40 mV increased KCachannel sensitivity to Ca2+sparks and elevated the percentage of Ca2+sparks that activated a transient KCacurrent from 59 to 86%. In a Ca2+-free bath solution or in diltiazem, a voltage-dependent Ca2+channel blocker, steady membrane depolarization between −40 and +40 mV increased transient KCacurrent frequency up to ∼1.6-fold. In contrast, caffeine (10 μM), an RyR channel activator, increased mean transient KCacurrent frequency but did not alter Ca2+spark-KCachannel coupling. These data indicate that coupling is increased by mechanisms that elevate KCachannel sensitivity to Ca2+sparks, but not by RyR channel activation. Overall, KCachannel insensitivity to Ca2+sparks is a prominent factor underlying fractional Ca2+spark uncoupling in newborn cerebral artery myocytes.
Peristalsis of airway smooth muscle is developmentally regulated and uncoupled from hypoplastic lung growth
Authors: Jesudason E. C. , Smith N. P. , Connell M. G. , Spiller D. G. , White M. R. H. , Fernig D. G. , Losty P. D.
Published: April 2006

Prenatal airway smooth muscle (ASM) peristalsis appears coupled to lung growth. Moreover, ASM progenitors produce fibroblast growth factor-10 (FGF-10) for lung morphogenesis. Congenital diaphragmatic hernia (CDH) is associated with lung hypoplasia, FGF-10 deficiency, and postnatal ASM dysfunction. We hypothesized ASM dysfunction emerges in tandem with, and may contribute toward, the primordial lung hypoplasia that precedes experimental CDH. Spatial origin and frequency of ASM peristaltic waves were measured in normal and hypoplastic rat lungs cultured from day 13.5 of gestation (lung hypoplasia was generated by nitrofen dosing of pregnant dams). Longitudinal lung growth was assayed by bud counts and tracing photomicrographs of cultures. Coupling of lung growth and peristalsis was tested by stimulation studies using serum, FGF-10, or nicotine and inhibition studies with nifedipine or U0126 (MEK1/2 inhibitor). In normal lung, ASM peristalsis is developmentally regulated: proximal ASM becomes quiescent (while retaining capacity for cholinergic-stimulated peristalsis). However, in hypoplastic lung, spontaneous proximal ASM activity persists. FGF-10 corrects this aberrant ASM activity in tandem with improved growth. Stimulation and inhibition studies showed that, unlike normal lung, changes in growth or peristalsis are not consistently accompanied by parallel modulation of the other. ASM peristalsis undergoes FGF-10-regulated spatiotemporal development coupled to lung growth: this process is disrupted early in lung hypoplasia. ASM dysfunction emerges in tandem with and may therefore contribute toward lung hypoplasia in CDH.
A "Study of Church in America": Catholicism as Exotic Other in The Damnation of Theron Ware
Authors: Urbanczyk Aaron
Published: April 2006

The Damnation of Theron Ware is the tale of a young Methodist minister's tragic downfall set in rural upstate New York. The inexperienced Reverend Ware finds himself in an environment which triggers his moral, spiritual, and intellectual degeneration. The novel represents Theron's temptations as a complex and organically connected web, at the center of which is Catholicism. "Unreformed" old world Roman Catholicism subsumes under its metaphorical auspices every specific register of transgressive alterity in Theron's imagination (e.g., ethnicity, aesthetics, the intellectual life, the erotic). Theron's romantic imagination radically misperceives Catholicism; it becomes the abyss of difference against which Theron gives way to "enlightened" agnosticism, pride, lust, avarice, covetousness, and self-loathing. The innocent young Methodist parson eventually loses his faith and becomes a stalker, a gossip, a thief, and a would-be adulterer. This transformation takes place through his experience with the Catholic "other" represented by Celia Madden, Father Vincent Forbes, and Dr. Ledsmar. Theron Ware misinterprets everyone associated with Catholicism, recasting the Catholic as the master trope under which all his desires for exotic transgression find an object. The Catholic becomes a dangerous mirror of Theron's perverse desires which "illumines" the way to his "Damnation."
Integrity of Mission in the Light of the Gospel: Bearing Witness of the Spirit Among Africa's Gospel Bearers
Authors: Mwaura Philomena Njeri
Published: April 2006

The church in Africa like its counterparts elsewhere in the world is called to fulfil the mission of Christ which is basically two fold; to liberate humankind on the social-political and economic plane and to lead them to salvation on the eschatological plane. This is self-evident for Christ was not only concerned with the spiritual needs of the people, but material as well. The question therefore arises how does the church in Africa bear witness to the spirit of God and conduct her mission with integrity in its contextual realities of HIV/AIDS, refugee crises, poverty, corruption and abuse of human rights? This paper argues that though the church faces this onerous task it is vibrant, alive and dynamic but for her to be relevant and effective she must develop more imaginative ways of doing mission, being church and theological formation. She needs to be a reconciler, mediating peace and healing due to the deep hurts and painful experiences the continent has encountered over the years. This calls for an ecumenical mission and vision that entails partnering in suffering by accompanying those in pain. She needs to disciple the members through surrendering herself to Christ to be purified, sanctified and renewed. She needs to provide courageous, empowered and effective leadership with moral integrity. She also needs to embody the spirit of unity and reconciliation in a pluralistic context and extend the biblical shalom of peace, justice to the marginalized poor, women displaced people, children, disabled and victims of all forms of violence. Mission with integrity also calls for listening to the other, dialogue and speaking out against all impediments to the gospel.
The 'Birth' of a Prophet: Andrew Wutawunashe's Break from the Reformed Church in Zimbabwe (Formerly Dutch Reformed Church)
Authors: Togarasei Lovemore
Published: April 2006

The examples of Old Testament prophets like Amos show that the call to prophecy is a life changing experience. This paper demonstrates that by looking at the 'birth' of Andrew Wutawunashe as a prophet. It opens with a brief history of the life of Wutawunashe showing how he was 'called' from pursuing university education to founding the Family of God church. It then discusses the possible reasons that led Wutawunashe to break from the Reformed Church in Zimbabwe. Although several reasons are suggested it is concluded that chief among them was his claim to prophetic inspiration.
Spatial Decay Estimates for the Biharmonic Equation in Plane Polars with Applications to Plane Elasticity
Authors: Chiriţă Stan , D'Apice Ciro
Published: April 2006

The present paper considers an isotropic and homogeneous elastic body occupying the arch-like region a ≤ r ≤ b, 0 ≤ θ ≤ α, where (r, θ) denote plane polar coordinates. The arch-like body is in equilibrium under an (in plane) self-equilibrated load on the edge r = a, while the other three edges r = b, θ = 0 and θ = α are traction-free and the body forces are absent. An appropriate measure is defined in terms of the Airy stress function ϕ, provided that the opening angle of the arch-like region is lower than 2 . Then the spatial behavior of the solution is studied and a clear relationship is established with Saint-Venant's principle on such regions. In fact, for a bounded arch-like region it is shown that the measure decays at least algebraically with respect to r, while for an unbounded region our result reveals a relationship with the classical Phragmèn—Lindelöf theorem.
Nonlinear Constitutive Laws in Viscoelasticity
Authors: Drapaca C.S. , Sivaloganathan S. , Tenti G.
Published: April 2006

The theory of viscoelasticity appears to play a central role in the description of materials which exhibit time dependent stress—strain behavior. Various materials like polymers, some soft biological tissues, and various foods have been already successfully modeled as nonlinear viscoelastic materials.The literature in these application areas is replete with different, seemingly unconnected nonlinear viscoelastic models. The aim of the present paper is to review the classical nonlinear viscoelastic models and provide a unifying framework using the continuum mechanics formalism.
Parameter Dependence of Multiscale Systems and Nanostructures on Crystals
Authors: Rieger Marc Oliver , Zirnstein Heinrich-Gregor
Published: April 2006

In the first part of this article (Sections 1 and 2) we study atomic steps on surfaces of crystals. The crystals under consideration are called “unorthodox” since their atomic steps form increasingly fine nanostructures when the temperature decreases. Using a physical model for the shape of atomic steps on the surface of these crystals (the HMM-model) we perform numerical simulations for terrace- and islandlike shapes of atomic steps. In the second part of this article (Section 3) we present a method for obtaining information on the parameter dependence of multiscale systems by means of Γ-convergence. We apply this concept to derive partial information on the temperature dependence of some of the physical constants in the HMM-model and reveal a more complicated interplay of the various parameters than originally expected. Our method may prove useful also in other physical problems with multiple scales.
The Incremental Bulk Modulus, Young's Modulus and Poisson's Ratio in Nonlinear Isotropic Elasticity: Physically Reasonable Response
Authors: Scott N.H.
Published: April 2006

An incremental (or tangent) bulk modulus for finite isotropic elasticity is defined which compares an increment in hydrostatic pressure with the corresponding increment in relative volume. Its positivity provides a stringent criterion for physically reasonable response involving the second derivatives of the strain energy function. Also, an average (or secant) bulk modulus is defined by comparing the current stress with the relative volume change. The positivity of this bulk modulus provides a physically reasonable response criterion less stringent than the former. The concept of incremental bulk modulus is extended to anisotropic elasticity. For states of uniaxial tension an incremental Poisson's ratio and an incremental Young's modulus are similarly defined for nonlinear isotropic elasticity and have properties similar to those of the incremental bulk modulus. The incremental Poisson's ratios for the isotropic constraints of incompressibility, Bell, Ericksen, and constant area are considered. The incremental moduli are all evaluated for a specific example of the compressible neo-Hookean solid. Bounds on the ground state Lamé elastic moduli, assumed positive, are given which are sufficient to guarantee the positivity of the incremental bulk and Young's moduli for all strains. However, although the ground state Poisson's ratio is positive we find that the incremental Poisson's ratio becomes negative for large enough axial extensions.
Superposition of transverse and longitudinal finite-amplitude waves in a deformed Blatz—Ko Material
Authors: Ferreira E. Rodrigues , Boulanger PH
Published: April 2006

In this paper, special Blatz—Ko nonlinear elastic materials are considered, which are characterized by a constitutive constant and a constitutive function. We here deal with the propagation of finite-amplitude waves in such materials subjected to an arbitrary static homogeneous deformation. In a previous paper, it was shown that linearly polarized transverse damped inhomogeneous plane waves may propagate. The orthogonal propagation and polarization directions are arbitrary. The special Blatz—Ko materials are compressible so that homogeneous longitudinal waves may also propagate. Here it is shown that the superposition of a transverse damped inhomogeneous wave and of a longitudinal wave is also a solution, in the case when the propagation direction of the longitudinal wave is orthogonal to the polarization direction of the transverse wave. Also, results are obtained for the energy density and the energy flux of the superposition of these waves.
On the Evolution of Plasticity and Incompatibility
Authors: Gupta Anurag , Steigmann David J. , Stölken James S.
Published: April 2006

The phenomenological theory of elastic—plastic response is reconsidered in the light of recent opinion regarding the constitutive character of the constituent elastic and plastic deformations. The primary role of dissipation in the physics of plastic evolution is emphasized and shown to lead to the clarification of a number of open questions. Particular attention is given to the invariance properties of the elastic and plastic deformations, to the kinematics of discontinuities, and to the role of material symmetry in restricting constitutive equations for elastic response, yield and plastic evolution.