bluuebunny/crossref_metadata_2025 huggingface dataset:
The Importance of Hippocampus-Dependent Non-Spatial Tasks in Analyses of Homology and Homoplasy
Authors: Day Lainy B.
Published: August 2003

The hippocampus or a homologous region plays a role in spatial tasks in a large number of vertebrate species. This result, in combination with recent findings of adaptive specializations of the hippocampus for spatial demands, has led to the conclusion that the prominent selective force behind hippocampal evolution was a need for spatial abilities. However, a review of non-spatial hippocampus-dependent tasks shows that many vertebrate species also share non-spatial functions of the hippocampus. Placed in the appropriate phylogenetic context, it becomes clear that non-spatial facets of hippocampal function were just as likely to be present in our vertebrate ancestors as spatial ones. In addition, the absence of spatial strategy use in three lineages suggests divergence of this feature. Divergence in this character and other characteristics of hippocampal function are meaningful indicators of lineage specific functions. Studies of the evolution of the hippocampus must include examination of spatial and non-spatial functions of the hippocampus and consider both conserved, as well as derived, features.
Memory and Hippocampal Specialization in Food-Storing Birds: Challenges for Research on Comparative Cognition
Authors: Shettleworth Sara J.
Published: August 2003

The three-way association among food-storing behavior, spatial memory, and hippocampal enlargement in some species of birds is widely cited as an example of a new ‘cognitive ecology’ or ‘neuroecology.’ Whether this relationship is as strong as it first appears and whether it might be evidence for an adaptive specialization of memory and hippocampus in food-storers have recently been the subject of some controversy [Bolhuis and Macphail, 2001; Macphail and Bolhuis, 2001]. These critiques are based on misconceptions about the nature of adaptive specializations in cognition, misconceptions about the uniformity of results to be expected from applying the comparative method to data from a wide range of species, and a narrow view of what kinds of cognitive adaptations are theoretically interesting. New analyses of why food-storers (black-capped chickadees, Poecile atricapilla) respond preferentially to spatial over color cues when both are relevant in a memory task show that this reflects a relative superiority of spatial memory as compared to memory for color rather than exceptional spatial attention or spatial discrimination ability. New studies of chickadees from more or less harsh winter climates also support the adaptive specialization hypothesis and suggest that within-species comparisons may be especially valuable for unraveling details of the relationships among ecology, memory, and brain in food-storing species.
The Homing Pigeon Hippocampus and Space: In Search of Adaptive Specialization
Authors: Bingman Verner P. , Hough II Gerald E. , Kahn Meghan C. , Siegel Jennifer J.
Published: August 2003

The hippocampus (HF) of birds and mammals is essential for the map-like representation of environmental landmarks used for navigation. However, species with contrasting spatial behaviors and evolutionary histories are likely to display differences, or ‘adaptive specializations’, in HF organization reflective of those contrasts. In the search for HF specialization in homing pigeons, we are investigating the spatial response properties of isolated HF neurons and possible right-left HF differences in the representation of space. The most notable result from the recording work is that we have yet to find neurons in the homing pigeon HF that display spatial response properties similar to HF ‘place cells’ of rats. Of interest is the suggestion of neurons that show higher levels of activity when pigeons are near goal locations and neurons that show higher levels of activity when pigeons are in a holding area prior to be being placed in an experimental environment. In contrast to the rat, the homing pigeon HF appears to be functionally lateralized. Results from a current lesion study demonstrate that only the left HF is sensitive to landmarks that are located within the boundaries of an experimental environment, whereas the right HF is indifferent to such landmarks but sensitive to global environmental features (e.g., geometry) of the experimental space. The preliminary electrophysiological and lateralization results offer interesting departure points for better understanding possible HF specialization in homing pigeons. However, the pigeon and rat HF reside in different forebrain environments characterized by a wulst and neocortex, respectively. Differences in the forebrain organization of pigeons and rats, and birds and mammals in general, must be considered in making sense of possible species differences in how HF participates in the representation of space.
The Evolution of the Cognitive Map
Authors: Jacobs Lucia F.
Published: August 2003

The hippocampal formation of mammals and birds mediates spatial orientation behaviors consistent with a map-like representation, which allows the navigator to construct a new route across unfamiliar terrain. This cognitive map thus appears to underlie long-distance navigation. Its mediation by the hippocampal formation and its presence in birds and mammals suggests that at least one function of the ancestral medial pallium was spatial navigation. Recent studies of the goldfish and certain reptile species have shown that the medial pallium homologue in these species can also play an important role in spatial orientation. It is not yet clear, however, whether one type of cognitive map is found in these groups or indeed in all vertebrates. To answer this question, we need a more precise definition of the map. The recently proposed parallel map theory of hippocampal function provides a new perspective on this question, by unpacking the mammalian cognitive map into two dissociable mapping processes, mediated by different hippocampal subfields. If the cognitive map of non-mammals is constructed in a similar manner, the parallel map theory may facilitate the analysis of homologies, both in behavior and in the function of medial pallium subareas.
Expression of Angiotensin II Type 1 Receptor in Rat Hepatic Stellate Cells and Its Effects on Cell Growth and Collagen Production
Authors: Zhang Yijun , Yang Xishan , Wu Pingsheng , Xu Li , Liao Guiqing , Yang Guoping
Published: August 2003

Objective: To investigate the contribution of angiotensin II towards the process of hepatic fibrosis that is largely due to hepatic stellate cell growth. Methods: Adult rat hepatic stellate cells were cultured and checked for the expression of angiotensin II receptor 1a (AT1a) mRNA by RT-PCR and sequence analysis. The effects of angiotensin II were observed on stimulation of hepatic stellate cell growth detected by MTT assays, 3H-thymidine incorporation and cell count, and collagen synthesis by 3H-proline incorporation. Results: We demonstrated that cultured adult rat hepatic stellate cells expressed AT1a mRNA, and angiotensin II in a concentration-dependent manner stimulated hepatic stellate cell growth at a concentration of 10–7–10–9 mol/l and collagen synthesis at a concentration of 10–6–10–10 mol/l. Also, AT1a receptor antagonist, in a concentration-dependent manner, blocked the cell growth from 10–6 to 10–8 mol/l and collagen synthesis from 10–6 to 10–9 mol/l. Conclusions: The results provided direct evidence that AT1a mRNA was expressed in rat hepatic stellate cells and angiotensin II could contribute towards the development of hepatic fibrosis via AT1a receptor.
Estrogen Decreases the Sensitivity of Anterior Pituitary to the Inhibitory Effect of Nitric Oxide on Prolactin Release
Authors: Velardez Miguel Omar , del Carmen Díaz María , Lasaga Mercedes , Franchi Ana María , Duvilanski Beatriz Haydée
Published: August 2003

Objective: We investigated the effect of chronic estrogen treatment on the inhibitory action of nitric oxide (NO) on prolactin release. Methods: The effect of NO on prolactin release was studied in anterior pituitaries of female Wistar rats, intact at random stages, ovariectomized (OVX), and OVX treated for 15 days with 17β-estradiol (OVX-E2). Results: Sodium nitroprusside (NP, 0.5 mM), a NO donor, inhibited prolactin release from anterior pituitaries and was able to stimulate cGMP synthesis in intact and OVX rats. Only a high, supraphysiological concentration of NP (2 mM) inhibited prolactin release from anterior pituitaries of OVX-E2 rats and increased cGMP synthesis in OVX-E2 rats. 8-Br-cGMP, a cGMP analogue, decreased prolactin release from anterior pituitaries of OVX rats but did not affect it in OVX-E2 rats. Conclusion: Our results suggest that estrogen may modify the sensitivity of the anterior pituitary to the inhibitory effect of NO on prolactin release by affecting guanylyl cyclase activity and the cGMP pathway.
Umbilical Cord Ghrelin Concentrations in Asian and Caucasian Neonates
Authors: Chanoine Jean-Pierre , Yeung Louisa P.K. , Wong Alfred C.K.
Published: August 2003

Objectives: To compare the relationship between cord plasma ghrelin and growth hormone (GH) concentrations and birth weight in Asian and Caucasian neonates. Methods: We measured umbilical cord ghrelin and GH concentrations in 180 full-term newborns [4 groups of 45 according to ethnicity (Caucasian/Asian) and sex]. Results: Ghrelin was detectable in all umbilical cord samples (mean ± SD: 611 ± 267, range 193–2,010 pg/ml). There was no significant difference in ghrelin concentrations between Asian and Caucasian male or female neonates. In contrast, GH values were significantly affected by sex (p = 0.001) and ethnicity (p = 0.006). Except for a weak (r = –0.33, p < 0.03) negative correlation between ghrelin and GH in male Caucasian neonates, ghrelin and GH concentrations were independent. Conclusions: Umbilical cord concentrations of ghrelin, a potent orexigenic and GH stimulatory agent, are similar in Caucasian and Asian newborns, suggesting that ghrelin does not play a causal role in the differences in body composition and GH metabolism observed in these neonates.
Presentation and 5-Year Follow-Up of Type 2 Diabetes mellitus in African-American and Caribbean-Hispanic Adolescents
Authors: Grinstein Gabriela , Muzumdar Radhika , Aponte Leonor , Vuguin Patricia , Saenger Paul , DiMartino-Nardi Joan
Published: August 2003

Objective: We report the presentation and 5-year follow-up of 89 African-American (AA) and Caribbean-Hispanic (CH) youths with type 2 diabetes mellitus (T2DM) followed at the Montefiore Medical Center, Bronx, N.Y., USA, from 1990 to 2000. Methods: The medical records of 89 patients with T2DM diagnosed between 1990 and 2000 were reviewed. Results: Over a 10-year period, the number of pediatric patients less than 18 years of age diagnosed with T2DM at the Montefiore Medical Center increased tenfold. At presentation, the mean age was 14 ± 2.3 years, the mean body mass index (BMI) was 34.4 ± 9 kg/m2, the female/male ratio was 1.6:1, and all these patients were pubertal. Acanthosis nigricans was present in 89% of the patients, polyuria and polydipsia occurred in 48%, weight loss occurred in 22%, and nearly 30% of the patients were asymptomatic at diagnosis. Diabetic ketoacidosis occurred in 5 patients. By 5 years after diagnosis, 45% of the patients were able to maintain an HgbA1C <7% with oral medications (metformin and/or glipizide); 18% required insulin (<0.4 U/kg/day) in addition to oral medications, and 37% did not require any medication. The mean insulin level, BMI and HgbA1C at the time of diagnosis did not predict treatment requirements for 3 years after diagnosis. Conclusions: Because the incidence of T2DM is increasing in adolescents, the natural history and optimal therapy for adolescents with T2DM need to be established.
Evaluation of the Parathyroid Function in Six Patients with Hypophosphatemic Osteomalacia, Including a Case of Tertiary Hyperparathyroidism Developing during Combined Oral Phosphate and Vitamin D Therapy
Authors: Jeon Hyun Jeong , Kwon Seong Hee , Kim Sang Wan , Shin Chan Soo , Park Kyung Soo , Kim Seong Yeon , Cho Bo Yeon , Lee Hong Kyu
Published: August 2003

Aim: To describe a case of tertiary hyperparathyroidism after long-term phosphate and vitamin D therapy and the retrospective evaluation of parathyroid function in 6 patients with hypophosphatemic osteomalaica. Methods: We evaluated the parathyroid function by measuring iPTH before and during treatment and divided the patients into normal and elevated serum iPTH groups. Results: In the normal serum iPTH group, the 4 patients were all males, whereas the 2 patients in the elevated serum iPTH group were females. Clinical characteristics and biochemical results showed no differences between the two groups. One of the women with an elevated iPTH level (224 pg/ml) had a normal serum calcium level and no evidence of increasing parathyroid uptake by 99mTc-MIBI scan 52 months after treatment. The other woman also had an elevated iPTH level (483 pg/ml) and a normal serum calcium level 56 months after treatment. However, in this latter case both her iPTH (1,447 pg/ml) and serum calcium (11.3 mg/dl) levels were elevated 113 months after treatment, when a 99mTc-MIBI scan showed increased uptake in all four parathyroid glands during early and delayed phases of the scan. Parathyroidectomy was performed after the diagnosis of tertiary hyperparathyroidism was made, and the histological findings showed adenomatous hyperplasia. Conclusions: Our findings indicate that even with vitamin D therapy, long-term phosphate therapy may lead to the development of secondary or tertiary hyperparathyroidism in hypophosphatemic osteomalacia and, therefore, suggest that it is important to carefully monitor the parathyroid function during therapy in those with hypophosphatemic osteomalacia.
Hormone Replacement Therapy Decreases Insulin Resistance and Lipid Metabolism in Japanese Postmenopausal Women with Impaired and Normal Glucose Tolerance
Authors: Sumino Hiroyuki , Ichikawa Shuichi , Itoh Hiromaro , Utsugi Toshihiro , Ohyama Yoshio , Umeda Mamoru , Nakamura Tetsuya , Kanda Tsugiyasu , Mizunuma Hideki , Tomono Shoichi , Murakami Masami , Kurabayashi Masahiko
Published: August 2003

Objects: To investigate the effect of combined estrogen and progesterone therapy on insulin resistance (IR) and carbohydrate and lipid metabolism in postmenopausal women (PMW) with impaired (IGT) and normal glucose tolerance (NGT). Methods: Sixteen Japanese PMW with IGT and 33 with NGT received daily oral hormone replacement therapy (HRT; 0.625 mg of conjugated equine estrogen plus 2.5 mg of medroxyprogesterone acetate) for 12 months. As controls, 13 Japanese PMW with IGT and 31 with NGT were enrolled and not treated by HRT. Fasting plasma glucose (FPG), fasting immunoreactive insulin (IRI), and IR were measured in each subject at study initiation and 12 months later. We used homeostasis model assessment (HOMA) to determine IR. Results: FPG and HOMA IR were decreased in both HRT groups, and fasting IRI was reduced in the HRT-NGT group. In controls, FPG, fasting IRI, and HOMA IR were unaltered. Total and low-density lipoprotein cholesterol were decreased and high-density lipoprotein cholesterol was increased in both HRT groups, but triglyceride was unchanged. In controls, lipid metabolism was unaltered. Conclusion: HRT decreased IR and improved carbohydrate and lipid metabolism in Japanese PMW with IGT and NGT. These beneficial effects argue for the use of HRT in PMW with IGT as well as NGT.
A New Missense Mutation of the Vasopressin-Neurophysin II Gene in a Family with Neurohypophyseal Diabetes insipidus
Authors: Wolf M.T.F. , Dötsch J. , Metzler M. , Holder M. , Repp R. , Rascher W.
Published: August 2003

Objective: Autosomal dominant familial neurohypophyseal diabetes insipidus is a rare disorder characterized by polydipsia and polyuria. We present the results of the molecular analysis of the AVP-NPII gene of a German kindred. Methods: All three exons of the gene were amplified by polymerase chain reaction and sequenced. Results: In 7 affected individuals a new missense mutation (1770G > T) in exon 2 was found predicting a cysteine to phenylalanine substitution at codon 58 in the neurophysin II domain (NPII). Conclusion: As a result of this mutation a cysteine residue is exchanged, which is involved in a disulfide bond with cysteine 44 of the NPII moiety, hypothesizing that the resulting misfolded protein may lead to chronic neurotoxicity by accumulation of these products in the endoplasmatic reticulum.
Erroneous Genetic Sex Determination of a Newborn Twin Girl due to Chimerism Caused by Foetal Blood Transfusion
Authors: Johannsen T.H. , Lundsteen C. , Visfeldt J. , Schwartz M. , Petersen B.L. , Byskov A.G. , Müller J.
Published: August 2003

Objective: We present a case of erroneous sex determination in a newborn twin girl (twin A) due to chimerism. Case Report: Amniocentesis and ultrasound examination had pointed towards male sex of both twins. At birth, twin A presented as a phenotypically normal female with 46,XY karyotype, and 46,XY gonadal dysgenesis was suspected. Twin B was a normal male. Results: In our department, further examinations of twin A included undetectable testosterone and inhibin-B and elevated FSH. Ultrasound suspected an infantile uterus, and sequencing of the SRY gene was normal. After gonadectomy, a 46,XX karyotype was demonstrated in both normal infantile ovaries and in the fibroblasts from a skin biopsy. Analysis of X-linked markers in DNA from blood lymphocytes in both twins was identical, consistent with 46,XY karyotypes. Conclusion: Twin A is a 46,XX female with a chimeric 46,XY blood cell line due to intrauterine transfusion from her twin brother.
Comparison of Final Height in Monozygotic Twins, One with Idiopathic and Isolated Growth Hormone Deficiency Treated with Low Dose of Growth Hormone
Authors: Sato Hirokazu , Miyamoto Shigeki , Noda Hiromasa , Sasaki Nozomu
Published: August 2003

Objective: We report final heights in a pair of monozygotic twins, one unaffected and the other affected with idiopathic and isolated growth hormone (GH) deficiency treated with human GH, and discuss the effect of GH dosage on the attainment of the genetic height potential in GH deficiency. Patients: Male monozygotic twins were born at 35 weeks of gestation; birth weights were 1,876 g in the unaffected and 1,510 g in the affected twin. At 4.9 years of age, the affected twin was studied for short stature (–3.38 SD) and was diagnosed as having idiopathic and isolated GH deficiency, whereas the unaffected twin was normal in height (± 0 SD). GH treatment was started at the age of 5.7 years and continued throughout childhood and adolescence. The average dose of GH administered during the treatment period was 0.35 IU (0.12 mg)/kg/week. The affected twin appeared to grow normally without other hormone replacement and achieved a final height of 165.6 cm (–0.86 SD) compared with that of 166.4 cm (–0.71 SD) in the unaffected twin at 17.5 years of age. Conclusion: Our results indicate that a relatively low dose of GH treatment started at an early age may preserve genetic height potential in patients with isolated GH deficiency.
Tension-Free Vaginal Tape Procedure: An Effective Minimally Invasive Operation for the Treatment of Recurrent Stress Urinary Incontinence?
Authors: Kuuva Nina , Nilsson Carl Gustaf
Published: August 2003

The aim of this study was to evaluate the results of tension-free vaginal tape (TVT) surgery in women with recurrent stress urinary incontinence (SUI). Fifty-one women with recurrent SUI were treated with TVT and followed prospectively for a minimum of 2 years according to a protocol. Twenty percent of the women had already undergone two previous continence procedures, whereas 80% had undergone only one. The mean follow-up period was 25.3 months. The objective cure rate was 89.6%, and the subjective cure rate 80.4%. No serious complications occurred. The majority of the patients were discharged in the afternoon of the operation day. No significant difference was observed between pre- and postoperative residual urine, maximal urethral closure pressure, and total and maximum voided urine volume values. However, the changes in urinary frequency, minimum voided volume, pad test results, and visual analog scale scores were highly significant. TVT appears to be a safe and suitable treatment for recurrent SUI.
The Potential Role of Advanced Glycation End Product and iNOS in Chronic Renal Failure-Related Testicular Dysfunction
Authors: Köksal İsmail Türker , Usta Mustafa Faruk , Akkoyunlu Gökhan , Toptaş Behiye , Gülkesen Kemal Hakan , Erdogru Tibet , Tuncer Murat , Baykal Aslı , Ersoy Fevzi , Demir Ramazan , Baykara Mehmet
Published: August 2003

Objectives: To investigate the impact of advanced glycation end products (AGEs) and inducible nitric oxide synthase (iNOS) in chronic renal failure (CRF)-associated testicular dysfunction in an experimental model. In additionally, we examined whether different peritoneal dialysis (PD) fluids could contribute to the elevation in AGE level and iNOS expression in the testes. Methods: Adult male Wistar rats, 10 and 12 weeks of age and weighing 200–330 g, were divided into 5 groups. Group 1 served as the control group. In group 2, CRF was induced and a peritoneal catheter was implanted, but the dialysis procedure was not performed until the end of the study. In group 3, CRF was induced and PD was performed with dialysis fluids containing 1.36% glucose and icodextrin. In group 4, CRF rats received dialysis fluids containing 3.86% glucose and icodextrin. Finally, an indwelling catheter was implanted and the dialysis procedure was performed using dialysis fluids containing 3.86% glucose and icodextrin (group 5). Chronic PD began 4 weeks after insertion of the catheter. Each morning, this fluid was drained and 20 ml dialysis fluid, containing either 1.36 or 3.86% glucose, was given intraperitoneally for 4 h in unanesthetized animals. Each evening, 20 ml icodextrin was given for 10 h. The dialysis procedure was performed for 8 weeks. The AGE level was determined from the 5-hydroxymethyl-2-furaldehyde (5-HMF) content of penis samples and iNOS expression was assessed by immunohistochemistry. Results: The elevation of 5-HMF was significant in the testes from groups 2, 3, 4, and 5 when compared with group 1. Furthermore, the differences between groups 2 and 4, 3 and 4, and 4 and 5 were also significant (p < 0.05). Immunohistochemical analysis revealed the presence of iNOS predominantly in the Leydig cells. While iNOS staining was significantly lower in group 1 than in other groups, there were also significant differences between groups 2 and 3, 2 and 4, 2 and 5, 3 and 5, and 4 and 5 (p < 0.05). Finally, a significant statistical correlation was found between the 5-HMF and iNOS levels (r = 0.698, p = 0.001). Conclusions: The present study identifies, for the first time, a potential role of AGE and iNOS in experimental CRF-associated testicular dysfunction. In addition, we found that PD fluids containing glucose contribute to this effect. These results may lead to a better understanding of the pathophysiological pathway in CRF-related testicular dysfunction.
Cyclic GMP Phosphodiesterases and Regulation of Smooth Muscle Function
Authors: Rybalkin Sergei D. , Yan Chen , Bornfeldt Karin E. , Beavo Joseph A.
Published: August 2003

Cyclic GMP (cGMP) made in response to atrial natriuretic peptide (ANP) or nitric oxide (NO) is an important regulator of short-term changes in smooth muscle tone and longer-term responses to chronic drug treatment or proliferative signals. The ability of smooth muscle cells (SMCs) to utilize different combinations of phosphodiesterase (PDE) isozymes allows cGMP to mediate these multiple processes. For example, PDE5 as a major cGMP-hydrolyzing PDE effectively controls the development of smooth muscle relaxation. In order for contraction to occur, PDE5 is activated and cGMP falls. Conversely, blockade of PDE5 activity allows the relaxation cycle to be prolonged and enhanced. A recently shown direct activation of PDE5 by cGMP binding to the GAF A domain suggests that this regulatory site might be a target for new drug development. The calcium surge associated with vasoconstrictor initiated contraction also activates a calcium/calmodulin-dependent PDE (PDE1A). Together, PDE5 and PDE1A lower cGMP sufficiently to allow contraction. Longer term, both PDE5 and PDE1A mRNA are induced by chronic stimulation of guanylyl cyclase. This induction is a major cause of the tolerance that develops to NO-releasing drugs. Finally, high levels of cGMP or cAMP also act as a brake to attenuate the proliferative response of SMCs to many mitogens. After vessel damage, in order for SMC proliferation to occur, the levels of cGMP and cAMP must be decreased. In humans, this decrease is caused in large part by induction of another Ca
2+
/calmodulin-dependent PDE (PDE1C) that allows the brake to be released and proliferation to start.
From “Life-Water” to “Death-Water” or On the Foundations of African Artistic Creation from Yesterday to Tomorrow
Authors: Diadji Iba Ndiaye
Published: August 2003

The question of water crosses all African cultures—water as the critical factor for a happy life (life-water) or water mastered as a source of malediction (death-water). The aquatic nature of such a civilization appears then as the foundation of shapes and contents of African artistic expression. An analysis of various forms of creation shows that, without a lucid understanding of the power of water in the constitution of Africa's identity, it is impossible to interpret correctly African art from yesterday to tomorrow.
Decon2 (Decon Squared): Deconstructing Decontamination
Authors: Mann Steve
Published: August 2003

Decon is short for decontamination (e.g. stripdown and washdown in response to anthrax scares, etc.), but the term “decon” is also a short form for “deconstruction” (literary criticism asserting multiple conflicting interpretations of philosophical, political or social implications rather than an author's intention). The author describes an anthrax ready mailroom exhibit that included mass casualty decontamination showers, which he built in the summer of 2001, based on a patent he filed in April 2000, to deconstruct the coming “war on terrorism” and the suspension of civil liberties and personal privacy that might follow in the wake of bioterror attacks.
Personal Profiles of Color Synesthesia: Developing a Testing Method for Artists and Scientists
Authors: Campen Crétien van , Froger Clara
Published: August 2003

The authors describe a practical method for assessing personal profiles of color:word, color:taste, color:music and color:odor synesthesia. The Netherlands Color Synesthesia (NeCoSyn) method is based on the Swedish Natural Color System and the test of genuineness for colored-word synesthesia developed by Baron-Cohen et al. The NeCoSyn method has been tested scientifically and shown to reliably distinguish different types of color synesthesia. It provides individual profiles of color synesthesia in the dimensions of hue, chroma and blackness. This article describes the method and discusses possible applications of NeCoSyn profiles in different fields of the arts and sciences.
Sense and Intersensoriality
Authors: Delalande François
Published: August 2003

Intersensoriality is part of the more general problem of musical meaning: How does sound relate to something outside of the world of sound? If we distinguish the “form” of sound from its “matter,” the discussion can then be divided into two parts. First, how can sound forms (shapes, profiles) suggest other temporal forms, such as movement? The hypothesis developed here is that sensorimotor experience is generalized to furnish a base, in successive layers, for identifying suggested movements that are more and more abstract. Secondly, how can a sound be said to be “hot” or “cold,” “dark” or “clear”? Metaphors concerning the matter of sound deal with a common level of synesthesia; a few stages of the historical study of this phenomenon are recalled here.
Motor-Mimetic Music Cognition
Authors: Godøy Rolf Inge
Published: August 2003

Music appeals to more than just our sense of hearing, and clearly we often associate other sensations with music. These non-sonorous sensations seem to be inseparable from the experience of music; in particular, images of movement appear to be deeply embedded in our perception and cognition of music. Explorations of mental images of music-related movement could enhance our understanding of music as a phenomenon, as well as be of practical value in various music-making tasks.
Synesthesia: A Multimodal Combination of Senses
Authors: Ternaux Jean-Pierre
Published: August 2003

Synesthesia is an unusual phenomenon that is occasionally reported in artists and writers. In its pathological context, synesthesia is described as a confusion of the senses where the excitation of one sense triggers stimulation in a completely different sensory modality. In contrast to this pathological form, synesthesia can also be considered as a physiological behavior that involves a multimodal combination of all senses. Such an expression of sensory perception can also be considered as a natural process that contributes to the adaptation of the living organism to its environment. The author attempts to analyze the cerebral mechanisms involved in sensory perception and synesthesia.
Coordinated Bare Definites
Authors: Heycock Caroline , Zamparelli Roberto
Published: August 2003

Recent work on the syntax and semantics of functional projections within the noun phrase has had as one goal an explanation for the crosslinguistic distribution of “bare” (determinerless) noun phrases. This article provides an account for an apparent anomaly: the relatively free occurrence of bare noun phrases under coordination. We argue that this construction involves coordination of projections below the DP level, with the coordinated structure subsequently raising to Spec, DP.Our analysis accounts for the fact that these nominals are endowed with uniqueness conditions, but only in some cases, and for a number of other hitherto undocumented facts, including complex constraints on modification.
Educational Leadership and Student Achievement: The Elusive Search for an Association
Authors: Witziers Bob , Bosker Roel J. , Krüger Meta L.
Published: August 2003

This study revisits the existing scholarly debate on the possible impact of the principal's leadership on student achievement. Both `direct effect' and `indirect effect' models are discussed. A quantitative meta-analysis examines to what extent principals directly affect student outcomes. The small positive effects found in this meta-analysis confirm earlier research findings on the limitations of the direct effects approach to linking leadership with student achievement. Finally, lines of future research inquiry are discussed.
Principal Leadership and School Performance: An Integration of Transformational and Instructional Leadership
Authors: Marks Helen M. , Printy Susan M.
Published: August 2003

Focusing on school leadership relations between principals and teachers, this study examines the potential of their active collaboration around instructional matters to enhance the quality of teaching and student performance. The analysis is grounded in two conceptions of leadership—transformational and instructional. The sample comprises 24 nationally selected restructured schools—8elementary, 8middle, and 8high schools. In keeping with the multilevel structure of the data, the primary analytic technique is hierarchical linear modeling (HLM). The study finds that transformational leadership is a necessary but insufficient condition for instructional leadership. When transformational and shared instructional leadership coexist in an integrated form of leadership, the influence on school performance, measured by the quality of its pedagogy and the achievement of its students, is substantial.
African American Women Principals in Urban Schools: Realities, (Re)constructions, and Resolutions
Authors: Bloom Collette M. , Erlandson David A.
Published: August 2003

The metaphor of visibility and its counterpart, invisibility, are paired throughout the article in an attempt to characterize the world of three African American women administrators as they struggle for equitable recognition—visibility—within the field of education. Using a naturalistic inquiry advocacy approach, analyses of in-depth interviews revealed portraits of women emerging from the visible absences, illusionary opportunities, and imaginary schools with stories of strength, identity formation, and a collective consciousness in working for and with the Black community in urban schools. Implications of this study for leadership theory, research, and practice are offered.
Mechanical-Morphology Relationship of PS Foams
Authors: Bureau Martin N. , Gendron Richard
Published: August 2003

The relationship between the morphology and the mechanical behavior of commercial PS foams has been investigated. The foams studied had a closed cell morphology with densities between 25 and74 kg/m3 and number-average cell sizes between 75 and 230 mm, and a normal cell size distribution (dv/dn 1.20). Mechanical results showed that the compressive strength and modulus could be expressed as a function of the foam morphology, using a unique morphological parameter taking into account the cell size and foam density. Flat sheet impact tests showed that three stages, i.e. damage initiation, damage propagation and damage coalescence leading to foam collapse, could be identified in the impact behavior of the foams. The maximum stress and the energy absorbed during impact could also be related to the morphological parameter proposed. A transition from a brittle to a ductile behavior could be rationalized using the proposed parameter.
Effect of Average Particle Size and Distribution on the Performance of Copolymer Polyols
Authors: Rath Aaron , Apichatachutapan Wassana , Gummaraju Raghuram , Neff Raymond , Heyman Duane
Published: August 2003

Copolymer (graft) polyols with varying particle size distribution were evaluated in a typical molded seating foam formulation. Three separate studies were conducted. In the first study, a graft polyol with a wide particle size distribution was fractionated by ultracentrifugation. The second and third studies used narrowly dispersed graft polyols of different average particle size and their blends. For the second study, the average particle sizes for the blend components were 0.26 and 7.6 mm (where the 7.6 mm component contained primarily 9 mm “large” particles). For the third study, they were 0.15, 1.4 and 3.0 mm. A three-component mixture experiment was designed for the third study, and the data was analyzed by model fitting. In the second study, cell opening increased and foam physical properties improved as the fraction of small particles in the bimodal blend increased. For the three-component mixture study, we report optimal blend compositions for cell opening, selected mechanical properties and flammability performance (MVSS302z). Optical microscopy of the foam cell structure and dynamic mechanical analysis (DMA) were conducted in order to explain the above results in terms of the interaction of the copolymer particles with the foam cell structure and polyurethane-urea matrix.
Stabilization of Rigid Systems Containing Aromatic Polyester Polyol and Water
Authors: McAdams Carina A. , Farmer Steven
Published: August 2003

With the phase-out of hydrochlorofluorocarbon blowing agents at hand, a challenge facing polyester polyol producers is providing products to the polyurethane industry suitable for use with next generation blowing agents. New products must produce foams with an excellent balance of properties and concurrently maintain cost-effectiveness. As the choices of the alternative blowing agents post HCFC-141b become more defined, it is apparent that higher levels of water in formulations will be an important choice for formulators for reducing cost and reducing the use of flammable blowing agents. A menacing problem for suppliers of systems containing water is the reaction stability as it relates to aging and/or storage. In this paper, the role of various components of the polyol resin (including aromatic polyester polyols, catalyst and flame retardant) in the reaction stability of HC- and HFC-blown rigid foam systems will be presented. Recommendations for stabilizing rigid foam systems containing aromatic polyester polyol and water will be provided.
Relationship between Dynamic Mechanical Properties and Water Absorption of Unsaturated Polyester and Vinyl Ester Glass Fiber Composites
Authors: Fraga Alicia N. , Alvarez Vera A. , Vazquez Analia , de la Osa Orlando
Published: August 2003

The effect of hydrothermal degradation on polyester and vinyl ester mat glass fiber composites on viscoelastic properties is investigated by dynamic mechanical thermal analysis and flexural modulus. The adhesion between fiber and matrix is studied by short-beam shear test and by SEM microphotographs. Storage modulus in the glass state (Tg - 50 K) and rubber state (Tg + 50 K) is also analyzed for the matrix and composites samples, before and after water immersion. Loss tangent (δ) is analyzed taken into account the values obtained for the materials in moisture sorption experiments.
Buckling Analysis of an Orthotropic Layer Bonded to a Substrate with an Interface Crack
Authors: Jeong K. M. , Beom H. G.
Published: August 2003

The buckling of an orthotropic layer bonded to a half-space with an interface crack subjected to compressive load under plane strain is analyzed. The theory of elasticity related to elastic stability is employed to investigate the buckling behavior of both the layer and the half-space. By the use of Fourier transforms, the boundary value problem is reduced to a system of homogeneous Cauchy-type singular integral equations of the second kind, which is solved numerically to determine the critical buckling loads. Numerical results are obtained for various geometric parameters and material properties of both the layer and the half-space. It is shown that the effect of orthotropy on the buckling load is to be distinct when the ratio of longitudinal modulus of the layer to the substrate is small or the ratio of layer thickness to the crack length is large.
The Effect of Matrix Microcracks on the Stress-Strain Relationship in Fiber Composite Tubes
Authors: Roberts S. J. , Evans J. T. , Gibson A. G. , Frost S. R.
Published: August 2003

A model for the stress-strain behavior of fiber composites with matrix cracks is presented and applied to the deformation of fiber reinforced composite pipes under different combinations of hoop and axial stress. The model provides a good description of the nonlinear stress-strain relationship that develops in composites when the matrix is damaged by the progressive nucleation of microcracks during loading. Ply properties are expressed as a function of crack density, calculated as a function of increasing stress using the shear-lag approximation. The predictions are in very good agreement with data from multiaxial tests on ±55° filament wound glass-reinforced epoxy pipes.
Mechanical Properties of SiCw/Al Composite Degraded by Thermal Cycling
Authors: Ahn J. J. , Ochiai S.
Published: August 2003

Mechanical properties of the SiCw/Al composite degraded by thermal cycling were examined using tensile tests and hardness measurements. Thermally cycled (TC) SiCw/Al was prepared through 100 thermal cycles between 200 and 300 C. Some of SiCw/Al were isothermally exposed (IE) at 300 C for 80 h for comparison. Fracture surface observation revealed the difference in fracture mechanism between the TC- and IE-SiCw/Al composites. Reduction of tensile strengths was greater in the TC-SiCw/Al than in the IE-SiCw/Al. The large reduction in the TC-SiCw/Al was caused by pulled-out whiskers, which was observed frequently in the fracture surfaces. While broken whiskers were observed markedly, indicating that whiskers of the IE-SiCw/Al carried external stress fully. The experimental results were verified theoretically using a shear-lag model for discontinuous fiber reinforced composites. Good agreement was found between experimental results and theoretical calculations.
On-Line Characterization of Bulk Permeability and Race-Tracking During the Filling Stage in Resin Transfer Molding Process
Authors: Devillard Mathieu , Hsiao Kuang-Ting , Gokce Ali , Advani Suresh G.
Published: August 2003

Resin Transfer Molding (RTM) is widely used to manufacture polymer composite materials. In this process, the fiber preform is placed in a closed mold and thermoset resin is injected to saturate the preform. After the resin cures the mold is opened and the net shape composite part is obtained. With RTM, one is capable of making complex and high quality composite parts with short cycle times. However, by introducing more complexity into the part, one also introduces higher probability of disturbances, such as race-tracking of resin during impregnation along preform edges. This can lead to incomplete saturation of fiber preform forming flaws such as dry spots in the composite part. The strength and existence of race-tracking is a function of the fabric type, perform manufacturing method, and their placement in the mold. It can vary from one part to the next in the same production run and usually it is not repeatable. The characterization of race-tracking and preform permeability is a key input for simulation tools that optimize the gates and vents locations and for designing advanced sensing and flow control strategies. This paper describes a method to estimate the strength and location of race-tracking and characterize the preform bulk permeability during the resin impregnation stage of RTM. The approach can be described in two steps. The first step generates simulations off line that map the overall range of potential disturbances likely to occur during the injection. The second step uses sensors placed in the mold, which allow one to identify the simulation within the database that resembles the experiment in terms of the filling behavior during the filling stage on the manufacturing platform. In the final step, this information is used to estimate race-tracking strength and location as well as the bulk permeability. Both experimental and numerical case studies show the reliability and accuracy of this method. It could be utilized for a broad range of applications such as active flow control, vent location optimization, and process monitoring of mold filling processes.
Experimental Characterization of an Innovative Glare® Fiber Reinforced Metal Laminate in Pin Bearing
Authors: Meola Carosena , Squillace Antonino , Giorleo Giuseppe , Nele Luigi
Published: August 2003

An experimental investigation is performed on an innovative Glare® Fiber Reinforced Metal Laminate (FRML), which is produced at the Alenia Aerospazio (Italy), with the aim to characterize its strength and behaviour in the case of mechanical joints. Several specimens are fabricated by varying width and hole-to-edge distance and tested in pin-bearing way without lateral restraints, which is the most critical testing procedure in the simulation of mechanical joints. Specimens, after bearing stress, are analysed in both non-destructive and destructive ways. Non-destructive evaluation is performed by means of lock-in thermography; for a validation of this technique, phase images are compared to photomicrographs. Results prove that a remote infrared imaging system may be a valuable tool to monitor the material behaviour either during the manufacturing processes, or in service.
Hydrostatic Extrusion of Metal Matrix Composites
Authors: Lahaie D. J. , Embury J. D.
Published: August 2003

The effect of hydrostatic pressure on the formability of a model Cu-W metal matrix composite (MMC) was investigated. The main experimental observation was that damaged and codeformed products were obtained from nominally identical Cu-W billets. A criterion for the suppression of damage during hydrostatic extrusion was developed. The resulting critical hydrostatic pressure criterion was estimated from slip line field theory in order to rationalize the experimental observations. The critical hydrostatic pressure for damage suppression in the W fibers depends on the ratio of fracture stress to flow stress. The analysis suggests a very important effect of both the stress state during hydrostatic extrusion and the previous processing history of the composite.
Evolution of Failure Mechanisms in 2D and 3D Woven Composite Systems Under Quasi-Static Perforation
Authors: Baucom J. N. , Zikry M. A.
Published: August 2003

The effects of reinforcement geometry, in 2D and 3D woven fabric-reinforced composites, on the progression of damage and perforation failure at quasi-static loading rates (10-80 mm/s) are investigated. The broad classes of glass-fiber-reinforced systems that were examined include 2D plain-woven laminates, 3D orthogonally woven monolithic systems, and 3D orthogonally woven laminates. The experimental results indicate that the 3D laminates consistently had greater damage tolerance than the 2D laminates and the 3D monolithic composites. The enhanced damage tolerance of the 3D systems is due to unique energy absorption mechanisms, which involve the crimped portion of z-tows.
Mechanical Properties and Water Absorption Behavior of Composites Made from a Biodegradable Matrix and Alkaline-Treated Sisal Fibers
Authors: Alvarez Vera A. , Ruscekaite Roxana A. , Vazquez Analia
Published: August 2003

Biocomposites were produced using a biodegradable material as matrix, and sisal fibers as reinforcement. The biodegradable material is a commercial product called MaterBi-Y, which is based on a cellulose derivatives and starch system. The characterization of these biocomposites was not done before and it is necessary in order to select a material instead of nonbiodegradable matrices. An alkaline treatment was performed in order to improve the mechanical properties of the fiber. The effect of the treatment on fiber properties and on impact, flexural, and tensile properties of composites were determined. Fiber content enhances the tensile properties of the biodegradable matrix. Water sorption studies were performed. The experimentally observed tensile properties (modulus and tensile strength) of short sisal fiber-reinforced cellulose derivatives/starch composites with different fiber loading are compared with the calculated values obtained from the existing theories of reinforcement.
Mechanisms of Hydrodynamically Induced In-Plane Deformation of Reinforcement Textiles in Resin Injection Processes
Authors: Endruweit A. , Gehrig S. , Ermanni P.
Published: August 2003

The effects of hydrodynamically induced textile deformation during resin injection in Liquid Composites Molding processes have been experimentally investigated for various fiber volume fractions in a rectangular flow channel with linear injection gate. For layups from bi-directional ±45° engineered glass fiber fabric, three deformation effects have been identified: Wrinkling of the topmost fabric layer for low fiber volume fractions, instantaneous in-plane compression of the layup during fiber wetting for intermediate fiber volume fractions, delayed in-plane compression of the wetted part of the fabric for high fiber volume fractions. The deformation behavior is determined by the fabric stiffness and the fixation in the flow channel due to clamping. The fabric has been experimentally characterized with respect to compressibility and coefficient of static friction in order to understand the clamping effect. The injection pressure, which is critical for deformation, has been determined as function of the fiber volume fraction, i.e. as function of the clamping pressure. The characteristics of the function have been correlated with the three observed deformation effects. A simple mechanical model for description of layup displacement and compression, implying visco-elastic behavior of the fabric and clamping with friction on the flow channel walls for various impregnation states, is presented.