bluuebunny/crossref_metadata_2025 huggingface dataset:
Adsorbate‐catalyzed anodic dissolution and oxidation at surfaces in aqueous solutions
Authors: Kelber J. , Seshadri G.
Published: September 2002

Certain adsorbates, particularly sulfur and iodine, present at submonolayer coverages catalyze anodic dissolution or oxidation at selected transition metal surfaces. No change in adsorbate surface coverage or oxidation state is observed during the dissolution process, indicating that the process is truly catalyzed by the adsorbed impurity. This allows enhanced dissolution to take place in environments entirely free of solvated forms of the impurity. In the case of iodine, the mechanism depends in part on the relative strength of iodine–metal vs. metal–metal bond strengths, but also depends on other factors that are as yet poorly understood. In the case of adsorbed sulfur, the effect is related to the ability of adsorbed sulfur to hinder the formation of an oxide layer via the complete dissociation of water at the solid surface. The relevance of these adsorbate‐catalyzed processes to intergranular stress corrosion cracking and semiconductor device processing are discussed. Copyright © 2001 John Wiley & Sons, Ltd.
In‐depth characterization of screen‐printed electrodes by laser‐induced breakdown spectrometry and pattern recognition
Authors: Amador‐Hernández J. , Fernández‐Romero J. M. , Luque de Castro M. D.
Published: September 2002

The application of laser‐induced breakdown spectrometry (LIBS) and chemometrics [namely principal component analysis (PCA) and cluster analysis (CA)] is presented for the characterization of screen‐printed electrodes with in‐depth resolution. An Nd : YAG laser operating at the fundamental wavelength of 1064 nm was focused on the sample and the plasma emission was collected by a fibre‐optic bundle coupled to a spectrograph–charge‐coupled device system. The experimental variables were optimized for a satisfactory spatial characterization. The different zones of the screen‐printed electrode were studied (working electrode, reference electrode and electrical contacts) in order to identify both the composition and distribution of the layers deposited on the inert support for the construction of the electronic device. Carbon, gold, silver, platinum, palladium, titanium and aluminium were identified as major components. The use of pattern recognition techniques (PCA and CA) for the statistical treatment of the spectroscopy data obtained by LIBS proved to be a powerful tool for the rapid analysis of miniaturized multilayer electronic devices. Copyright © 2001 John Wiley & Sons, Ltd.
Corporate tournaments and executive compensation: Evidence from the U.K.
Authors: Conyon Martin J. , Peck Simon I. , Sadler Graham V.
Published: September 2002

This study tests the implications of tournament theory using data on 100 U.K. stock market companies, covering over 500 individual executives, in the late 1990s. Our results provide some evidence consistent with the operation of tournament mechanisms within the U.K. business context. Firstly, we find a convex relationship between executive pay and organizational level and secondly, that the gap between CEO pay and other board executives (i.e., tournament prize) is positively related to the number of participants in the tournament. However, we also show that the variation in executive team pay has little role in determining company performance. Copyright © 2001 John Wiley & Sons, Ltd.
Strategic reward systems: a contingency model of pay system design
Authors: Boyd Brian K. , Salamin Alain
Published: September 2002

A limited number of studies have addressed the idea of ‘strategic’ reward systems—the matching of compensation systems to a firm's strategy. Prior research on this topic has been confined to U.S. firms, however, and a number of key questions remain unanswered. Using a sample of 917 employees from two large Swiss financial institutions, we found that pay systems are linked with divisional strategic orientation, but in a different form than prior studies. Additionally, we identify hierarchical position as an important variable in the tailoring of reward systems. Hierarchy has a significant main effect on pay plan design, and an interactive effect with strategic orientation. Copyright © 2001 John Wiley & Sons, Ltd.
From gap gazing to promising cases: Moving toward equity in urban education reform*
Authors: Rodriguez Alberto J.
Published: September 2002

A case analysis of the Miami‐Dade Urban Systemic Initiative is presented in this article, citing this initiative as one of the sites with the greatest promise for affecting equity issues. Using a grounded‐theory methodological approach, a general framework for systemic reform was developed as a tool to examine the particulars of systemic reform initiatives and their potential to impact the teaching and learning of science and mathematics in diverse school contexts. It was found that to better understand the effectiveness of systemic reform initiatives requires answering two basic questions: What is the (pedagogical and ideological) systemic conceptual clarity guiding the reform efforts? And, what is the operational approach? Once answers to these questions are found, it becomes easier to explore how key officials are implementing or not implementing other aspects of systemic reform. The article also explains why less attention should be given to student outcomes (based on standardized tests) as the main indicator of success in systemic reform. Instead, it is proposed that insights gained from studying the particulars of promising initiatives can help others stimulate systemic reform in their own contexts, especially in urban contexts, which usually have few resources and a large population of students who are traditionally underserved. © 2001 John Wiley & Sons, Inc. J Res Sci Teach 38: 1115–1129, 2001
Rethinking diversity in learning science: The logic of everyday sense‐making
Authors: Warren Beth , Ballenger Cynthia , Ogonowski Mark , Rosebery Ann S. , Hudicourt‐Barnes Josiane
Published: September 2002

There are many ways to understand the gap in science learning and achievement separating low‐income, ethnic minority and linguistic minority children from more economically privileged students. In this article we offer our perspective. First, we discuss in broad strokes how the relationship between everyday and scientific knowledge and ways of knowing has been conceptualized in the field of science education research. We consider two dominant perspectives on this question, one which views the relationship as fundamentally discontinuous and the other which views it as fundamentally continuous. We locate our own work within the latter tradition and propose a framework for understanding the everyday sense‐making practices of students from diverse communities as an intellectual resource in science learning and teaching. Two case studies follow in which we elaborate this point of view through analysis of Haitian American and Latino students' talk and activity as they work to understand metamorphosis and experimentation, respectively. We conclude with a discussion of the implications of this new conceptualization for research on science learning and teaching. © 2001 John Wiley & Sons, Inc. J Res Sci Teach 38: 529–552, 2001
Isolation and sequence of the MIG1 homologue from the yeast Candida utilis
Authors: Delfin Julieta , Perdomo Walmer , García Bianca , Menendez Javier
Published: September 2002

The Mig1p repressor from the food yeast Candida utilis has been isolated using a homologous PCR hybridization probe. This probe was amplified with two sets of degenerate primers designed on the basis of highly conserved motifs in the DNA‐binding region (zinc‐finger domain) from yeast Mig1p and fungi CreA repressors. The cloned gene was sequenced and found to encode a polypeptide of 345 amino acids which shows significant identity with other yeast and fungus repressors in the DNA‐binding domain and also with the yeast Mig1 proteins in the C‐terminal region (effector domain). The MIG1 repressor gene from C. utilis was able to complement functionally the mig1 mutation of S. cerevisiae. The sequence presented here has been deposited in the EMBL data library under Accession No. AJ277830. Copyright © 2001 John Wiley & Sons, Ltd.
Lifetime semen production in a cheetah (Acinonyx jubatus)
Authors: Durrant Barbara S. , Millard Susan E. , Zimmerman Dawn M. , Lindburg Donald G.
Published: September 2002

Lifetime semen production data provide valuable insight into a species’ natural history and biology as well as information about the potential fertility of males at various life stages. An understanding of the ages of sexual maturity, peak sperm production, and gonadal senescence will contribute to the design of species management plans for captive, free‐ranging, and reintroduced populations of exotic animals. To describe these life stages in the cheetah, semen was collected biweekly for 13 years from a solitary male beginning at 3 years of age. The 338 ejaculates were obtained noninvasively by artificial vagina. Ejaculate volume and sperm motility score, concentration, and normal morphology were recorded. A sperm quality index incorporating all five semen parameters was calculated to facilitate ejaculate comparisons. Polynomial regression analysis revealed a significant effect of age on volume, which increased throughout the animal’s lifetime except for a reduction between ages 10 and 12. Concentration was also significantly affected by age and increased from the age of 3 to the age of 10, then decreased. The sperm quality index revealed a significant effect of age as it increased from age 3 to age 8, then declined as the male grew older. The cheetah did not reach peak semen production until age 8 and continued to produce good quality semen for several more years. These data were somewhat unexpected, given the average cheetah life expectancy of approximately 7 years. Zoo Biol 20:359–366, 2001. © 2001 Wiley‐Liss, Inc.
Investigating the effects of anxiety sensitivity and coping on the perception of cold pressor pain in healthy women
Authors: Keogh Edmund , Mansoor Louise
Published: September 2002

Research indicates that anxiety sensitivity may be related to the negative experience of pain, especially amongst women. Further evidence with chronic pain patients indicates that anxiety sensitivity may result in avoidance pain‐coping strategies. However, this effect has not yet been experimentally investigated in healthy groups. Therefore, the current study sought to investigate the effect of anxiety sensitivity and coping on women’s responses to pain. Thirty women who were classified as high in anxiety sensitivity and 30 women classified as low in anxiety sensitivity participated. Within each anxiety sensitivity group, half the participants (n = 15) were randomly instructed to either focus on or avoid cold pressor pain sensations. As expected, women high in anxiety sensitivity were found to report higher levels of sensory and affective pain. Also, and consistent with previous research into anxiety sensitivity, no differences were found between anxiety sensitivity groups for measures of pain threshold or pain tolerance. The pain coping instruction manipulation was found to moderate pain experience, in that the avoidance strategy resulted in higher pain ratings compared to when instructed to focus. Finally, high anxiety sensitive women reported greater pain when instructed to avoid rather than focus on cold pressor pain. These results are discussed in light of previous research and future directions for pain management.
Long‐term fluctuations of pressure pain thresholds in healthy men, normally menstruating women and oral contraceptive users
Authors: Isselée Hans , De Laat Antoon , Bogaerts Kris , Lysens Roeland
Published: September 2002

The aim of this investigation was to evaluate whether the pressure pain threshold (PPT) in masticatory muscles of symptom‐free subjects was influenced by fluctuations of the sex hormones. The PPT was measured with an electronic algometer for at least 10 consecutive menstrual cycles in 10 women using oral contraceptives and 10 women not using oral contraceptives, with a regular menstrual cycle (26–31 days). In addition, 10 men were measured in a regular pattern over a period of 1 year. All subjects were symptom‐free with an age range between 18 and 39 years. Measurement sessions were held during three different cycle phases (follicular, luteal, perimenstrual) and each session consisted of four consecutive PPT measurements. By means of a linear mixed model (SAS), the PPTs of the masster, temporalis and thumb muscles were compared between: (1) groups, (2) sex‐hormonal phases, (3) the four consecutive measurements of each muscle per session and (4) time. The PPTs of the masseter (p = 0.8419) and temporalis muscles (p = 0.2786) did not change significantly over time. There was no significant difference in variance for the masseter (p = 0.6250), temporalis (p = 0.9705) and thumb (p = 0.7446) between the three groups. The PPTs of all muscles were significantly lower during the perimenstrual phases in the two female groups. The present data showed similar patterns of PPTs for the three muscle groups. Moreover, the results have shown a very good consistency of the PPTs over a long time period, both in males and females.
Knee joint mobilization reduces secondary mechanical hyperalgesia induced by capsaicin injection into the ankle joint
Authors: Sluka K. A. , Wright A.
Published: September 2002

Joint mobilization is a treatment approach commonly used by physical therapists for the management of a variety of painful conditions. However, the clinical effectiveness when compared to placebo and the neurophysiological mechanism of action are not known. The purpose of this study was to establish that application of a manual therapy technique will produce antihyperalgesia in an animal model of joint inflammation and that the antihyperalgesia produced by joint mobilization depends on the time of treatment application. Capsaicin (0.2%, 50 μ l) was injected into the lateral aspect of the left ankle joint and mechanical withdrawal threshold assessed before and after capsaicin injection in Sprague‐Dawley rats. Joint mobilization of the ipsilateral knee joint was performed 2 h after capsaicin injection for a total of 3 min, 9 min or 15 min under halothane anaesthesia. Control groups included animals that received halothane for the same time as the group that received joint mobilization and those whose limbs were held for the same duration as the mobilization (no halothane). Capsaicin resulted in a decreased mechanical withdrawal threshold by 2 h after injection that was maintained through 4 h. Both 9 and 15 min of mobilization, but not 3 min of mobilization, increased the withdrawal threshold to mechanical stimuli to baseline values when compared with control groups. The antihyperalgesic effect of joint mobilization lasted 30 min. Thus, joint mobilization (9 or 15 min duration) produces a significant reversal of secondary mechanical hyperalgesia induced by intra‐articular injection of capsaicin.
A system to generate electronic books on programming exercises
Authors: Gregorio‐Rodríguez C. , Llana‐Díaz L.F. , Pareja‐Flores C. , Martínez‐Unanue R. , Velázquez‐Iturbide J.Á. , Palao‐Gostanza P.
Published: September 2002

Electronic books offer a number of possibilities for innovation over paper books in certain fields. It is the case of programming exercises, which have a complex but well‐established structure. We describe a system for the development of electronic books on programming exercises. A mark‐up language, called eXercita, was designed to represent and manage programming exercises in a comprehensive manner. Several tools allow customizing exercises to the user’s purposes, as well as selecting parts of individual exercises and subsets of the repository. As a consequence, the user can generate a custom electronic book, presented as a hierarchical Web site and implemented structured according to a given specified criterion. Based on the eXercita language, we have developed a large repository of exercises, as well as two books: an electronic book on the Web and a paper book containing a set of selected exercises.
Obtaining feedback for indexing from highlighted text
Authors: Villarroel Miguel , de la Fuente Pablo , Pedrero Alberto , Vegas Jesús , Adiego Joaquín
Published: September 2002

The indexing techniques most commonly applied in information retrieval systems associate weights to the terms of documents; this association is carried out in order to quantify the term’s capacity for representing the document. Subsequently, these weights are used in query processing, playing an important role in the performance of the system. This work presents a method for the adjustment of index weights by processing text that has been highlighted by users. Text in a document is highlighted using an application which provides annotation facilities in order to support active reading. Highlighted text is supposed to be of special relevance and the method tries to improve the index weights of terms located in these highlighted fragments.
Two low income social housings
Authors: José Mascaró Juan
Published: September 2002

This paper studies the environmental behavior of two low‐income social housings: one is located in Barcelona, Spain, and the other in Porto Alegre, Brazil. They were both built around the same time. A comparative study of the climates of each of the cities under consideration was made, pointing out the similarities and differences. The gathering of data was done through in situ measurement of the environmental characteristics of the open areas of the both low income multistorey housing and of the interior of two typical apartments. The technique of observation was also used to register the use and characteristics of the studied spaces. At the same time, the solar insulation was studied throughout the year, using the solar simulator (“heliodon”). The computer simulations were done to analyze the natural lateral lighting and the natural ventilation. Based on the environmental measurements done throughout the year and the opinion poll about the satisfaction of the user, the principles of projects and constructive characteristics, the condition of the resulting habitability, as well as the ways of using the exterior and interior spaces and the user’s opinion about their residence were analyzed. It concludes with an evaluation of the results obtained.
Urban planning instruments to improve winter solar access in open public spaces
Authors: Jose Leveratto Maria
Published: September 2002

There is general consensus about the lack of open green spaces in Buenos Aires. Due to this, different actions are been proposed to improve the quality of existing ones. This paper analyses potential modifications of built forms to allow better winter solar access and ameliorate microclimatic conditions of those spaces, increasing their usability throughout the year. A typical urban configuration, within the dense residential grid, is simulated to evaluate the effects, advantages and limitations of this proposal. In one case, volumes are shaped following existing planning codes. In the other, modifications to avoid shadows on the open space during the cold period of the year are included. Resulting environments are evaluated and compared taking into account urban and economic implications of the decisions involved.
BIFURCATION, BURSTING AND SPIKE GENERATION IN A NEURAL MODEL
Authors: GOVAERTS W. , DHOOGE A.
Published: September 2002

Bursting is an important behavior pattern of nerve cells and in mathematical models it is often related to bifurcations. However, the onset of bursting and the birth of new spikes are also possible without any bifurcation.

We present a numerical study of a model of Plant which exhibits a periodically bursting behavior in a relevant range of two parameters. In this two-dimensional range the behavior changes continuously, except for a number of tiny regions where spikes are born or die. These islands are extensions of bifurcation islands.

It appears that the generation of spikes can be related to local extrema of the periods of the bursting periodic orbits. This allows to detect the birth of spikes also in parameter regions where no bifurcations occur.

From a biological point of view the average instantaneous spike frequency is probably the most important output variable of a neuron. We show that in the Plant model (in contrast to some other models) this frequency is essentially determined by the number of spikes in a burst.
Dose Response of Almonds on Coronary Heart Disease Risk Factors: Blood Lipids, Oxidized Low-Density Lipoproteins, Lipoprotein(a), Homocysteine, and Pulmonary Nitric Oxide
Authors: Jenkins David J.A. , Kendall Cyril W.C. , Marchie Augustine , Parker Tina L. , Connelly Philip W. , Qian Wei , Haight James S. , Faulkner Dorothea , Vidgen Edward , Lapsley Karen G. , Spiller Gene A.
Published: September 2002

Background—

Although recent studies have indicated that nut consumption may improve levels of blood lipids, nuts are not generally recommended as snacks for hyperlipidemic subjects because of their high fat content. Furthermore, the effective dose is still unknown.

Methods and Results—

The dose-response effects of whole almonds, taken as snacks, were compared with low-saturated fat (<5% energy) whole-wheat muffins (control) in the therapeutic diets of hyperlipidemic subjects. In a randomized crossover study, 27 hyperlipidemic men and women consumed 3 isoenergetic (mean 423 kcal/d) supplements each for 1 month. Supplements provided 22.2% of energy and consisted of full-dose almonds (73±3 g/d), half-dose almonds plus half-dose muffins, and full-dose muffins. Fasting blood, expired air, blood pressure, and body weight measurements were obtained at weeks 0, 2, and 4. Mean body weights differed <300 g between treatments. The full-dose almonds produced the greatest reduction in levels of blood lipids. Significant reductions from baseline were seen on both half- and full-dose almonds for LDL cholesterol (4.4±1.7%,
P
=0.018, and 9.4±1.9%,
P
<0.001, respectively) and LDL:HDL cholesterol (7.8±2.2%,
P
=0.001, and 12.0±2.1%,
P
<0.001, respectively) and on full-dose almonds alone for lipoprotein(a) (7.8±3.5%,
P
=0.034) and oxidized LDL concentrations (14.0±3.8%,
P
<0.001), with no significant reductions on the control diet. No difference was seen in pulmonary nitric oxide between treatments.

Conclusions—

Almonds used as snacks in the diets of hyperlipidemic subjects significantly reduce coronary heart disease risk factors, probably in part because of the nonfat (protein and fiber) and monounsaturated fatty acid components of the nut.
Contribution of Exercise-Induced Mitral Regurgitation to Exercise Stroke Volume and Exercise Capacity in Patients With Left Ventricular Systolic Dysfunction
Authors: Lapu-Bula Rigobert , Robert Annie , Van Craeynest David , D’Hondt Anne-Marie , Gerber Bernhard L. , Pasquet Agnès , Melin Jacques A. , De Kock Martine , Vanoverschelde Jean-Louis
Published: September 2002

Background—

Functional mitral regurgitation (MR) is common in patients with heart failure and left ventricular (LV) dysfunction, and its severity may vary over time, depending primarily on the loading conditions. Because dynamic changes in the severity of functional MR may affect forward stroke volume, we hypothesized that exercise-induced changes in MR severity influence the stroke volume response of patients with LV dysfunction to exercise, and hence their exercise capacity.

Methods and Results—

Heart failure patients (n=25; mean age 53±12 years) with LV dysfunction underwent dynamic bicycle exercise at steady-state levels of 30%, 60%, and 90% of predetermined peak V̇
o
2
. During each exercise level, right heart pressures, cardiac output, V̇
o
2
, and MR severity were measured simultaneously. During exercise, MR severity, as evaluated by the ratio of MR jet over left atrium area, increased from 15±8% to 33±15%. Peak V̇
o
2
, exercise-induced changes in stroke volume, and those in capillary wedge pressure correlated with the changes in MR (
r
=−0.55, −0.87, and 0.62, respectively,
P
<0.01). The changes in MR severity also correlated with those in end-diastolic (
r
=−0.75,
P
<0.01) and end-systolic (
r
=−0.72,
P
<0.01) sphericity indexes and those in the coaptation distance (
r
=0.86,
P
<0.01).

Conclusions—

Our data indicate that in patients with LV dysfunction, exercise-induced changes in MR severity limit the stroke volume adaptation during exercise and therefore contribute to limitation of exercise capacity.
Natural History of Asymptomatic Mitral Valve Prolapse in the Community
Authors: Avierinos Jean-François , Gersh Bernard J. , Melton L. Joseph , Bailey Kent R. , Shub Clarence , Nishimura Rick A. , Tajik A. Jamil , Enriquez-Sarano Maurice
Published: September 2002

Background—

The outcome of mitral valve prolapse (MVP) is controversial, with marked discrepancies in reported complication rates.

Methods and Results—

We conducted a community study of all Olmsted County, Minn, residents first diagnosed with asymptomatic MVP between 1989 and 1998 (N=833). Diagnosis, motivated by auscultatory findings (n=557) or incidental (n=276), was always confirmed by echocardiography with the use of current criteria. End points analyzed during 4581 person-years of follow-up were mortality (n=96, 19±2% at 10 years), cardiovascular morbidity (n=171), and MVP-related events (n=109, 20±2% at 10 years). The most frequent primary risk factors for cardiovascular mortality were mitral regurgitation from moderate to severe (
P
=0.002, n=131) and, less frequently, ejection fraction <50% (
P
=0.003, n=31). Secondary risk factors independently predictive of cardiovascular morbidity were slight mitral regurgitation, left atrium ≥40 mm, flail leaflet, atrial fibrillation, and age ≥50 years (all
P
<0.01). Patients with only 0 or 1 secondary risk factor (n=430) had excellent outcome, with 10-year mortality of 5±2% (
P
=0.17 versus expected), cardiovascular morbidity of 0.5%/y, and MVP-related events of 0.2%/y. Patients with ≥2 secondary risk factors (n=250) had mortality similar to expected (
P
=0.20) but high cardiovascular morbidity (6.2%/y,
P
<0.01) and notable MVP-related events (1.7%/y,
P
<0.01). Patients with primary risk factors (n=153) showed excess 10-year mortality (45±9%,
P
=0.01 versus expected), high morbidity (18.5%/y,
P
<0.01), and high MVP-related events (15%/y,
P
<0.01).

Conclusions—

Natural history of asymptomatic MVP in the community is widely heterogeneous and may be severe. Clinical and echocardiographic characteristics allow separation of the majority of patients with excellent prognosis from subsets of patients displaying, during follow-up, high morbidity or even excess mortality as direct a consequence of MVP.
Toward an Aposynthesis of Topic Continuity and Intrasentential Anaphora
Authors: Miltsakaki Eleni
Published: September 2002

The problem of proposing referents for anaphoric expressions has been extensively researched in the literature and significant insights have been gained through the various approaches. However, no single model is capable of handling all the cases. We argue that this is due to a failure of the models to identify two distinct processes. Drawing on current insights and empirical data from various languages we propose an aposynthetic 1 model of discourse in which topic continuity, computed across units, and focusing preferences internal to these units are subject to different mechanisms. The observed focusing preferences across the units (i.e., intersententially) are best modeled structurally, along the lines suggested in centering theory. The focusing mechanism within the unit is subject to preferences projected by the semantics of the verbs and the connectives in the unit as suggested in semantic/pragmatic focusing accounts. We show that this distinction not only overcomes important problems in anaphora resolution but also reconciles seemingly contradictory experimental results reported in the literature. We specify a model of anaphora resolution that interleaves the two mechanisms. We test the central hypotheses of the proposed model with an experimental study in English and a corpus-based study in Greek.

1 “Aposynthesis” is a Greek word that means “decomposition,” that is, pulling apart the components that constitute what appears to be a uniform entity.
Essentialism and Folkbiology: Evidence from Brazil
Authors: Sousa Paulo , Atran Scott , Medin Douglas
Published: September 2002

Experimental results in reference to Brazilian children and adults are presented in the context of current discussions about essentialism and folkbiology. Using an adoption paradigm, we replicate the basic findings of a previous article in this journal concerning the early emergence in children of a birth-parent bias (Atran et al. 2001). This cognitive bias supports the claim that causal essentialism cross-culturally constrains the reasoning about the origin, development and maintenance of the characteristics and identity of living kinds. We also report some intriguing differences with earlier findings that speak to theoretical and methodological issues of cultural relativity.
Optimistic, Approach‐oriented, and Avoidance Strategies in Social Situations: Three Studies on Loneliness and Peer Relationships
Authors: Nurmi Jari‐Erik , Toivonen Sari , Salmela‐Aro Katariina , Eronen Sanna
Published: September 2002

The aim of the three studies was to examine the extent to which the cognitive and behavioural strategies young adults apply in social situations are associated with their subsequent feelings of loneliness, their peer relationships, and social behaviour. In Study 1, 303 young adults first filled in the Strategy and Attribution Questionnaire (SAQ) and, 1 year later, the revised UCLA Loneliness scale. In Study 2, 71 young adults filled in first the SAQ and, 4 months later, the UCLA Loneliness scale and a sociometric questionnaire measuring popularity and unpopularity. In Study 3, 35 young adults who had participated in Study 1 were rated by student tutors according to their social behaviour in an academic group situation. The results showed that the less optimistic the subjects were, the less they applied an approach‐oriented strategy, and the more they used a social avoidance strategy, the more lonely they were. Furthermore, the more they used an approach‐oriented strategy and the less they reported social avoidance, the more successful they were in their peer relationships. These two strategies were also associated with the ways in which an observer perceived their behaviour in a group situation, whereas social optimism was not.
Ionic versus Covalent Bonding in Dilithium Porphyrins: X-ray Structure of Dilithium Tetraphenylporphyrin Bis(etherate)
Authors: DAWSON DENISHA Y. , ARNOLD JOHN
Published: September 2002

The solid state structure of dilithium tetraphenylporphyrin bis(etherate) has been determined by X-ray crystallography. The structure shows the lithium atoms are displaced out of the plane of the porphyrin, each coordinated in a square pyramidal fashion to the four nitrogen atoms in addition to a molecule of diethyl ether. The lithium atoms are identical, as required by the crystallographic inversion centre. X-ray data are as follows: [Formula: see text] (# 2) with a = 10.1908(4) Å, b = 11.6553(4) Å, c = 12.5199(5) Å, α = 111.644(1)°, β = 98.029(1)°, γ = 111.883(1)°, V = 1214.61(9)Å3, dcalc = 1.171 g cm -3 and Z = 1.
Tetra(n-butyl)ammonium Dicyanotetraphenyl-porphyrinatomanganate(III); Crystal Structure and Electronic Resonance Raman and Absorption Spectra
Authors: GALICH LUTZ , HÜCKSTÄDT HEINER , HOMBORG HEINER
Published: September 2002

The title complex salt has been isolated from a solution of chlorotetraphenylporphyrinatomanganese(III) and tetra(n-butyl)ammonium cyanide in dichloromethane. The complex salt crystallizes as a hydrate-dichloromethane solvate in the orthorhombic space group Pbca (no. 61) with cell parameters as follows: a = 21.491(5) Å, b = 21.706(5) Å, c = 28.489(5) Å, V = 13 290(5) Å3, Z = 8. The structure is that expected for a hexa-coordinated low-spin Mn ( III ) tetraphenylporphyrinate (magnetic moment: μ eff = 3.1 ± 0.2 μ B at 273 K). The Mn atom is in the centre of the slightly ruffled porphyrinato core. The Mn - C CN distance of 2.01(2)/2.02(2) Å and the Mn - N p distance, varying between 1.972(13) and 2.016(14) Å, are normal values. The Mn - C CN - N group is bent (171(2)/174(2) °). At low temperatures, a molecular electronic resonance Raman effect is detected at 198 and 344 cm−1. It is attributed to intraconfigurational transitions Γ 1g → Γ 4g and Γ 1g → Γ 3g Γ 5g , respectively, arising from the spin-orbit split 3 T 1g ground state of low-spin Mn ( III ), assuming pseudo-octahedral symmetry. Weak Q and intense B (Soret) transitions at 17 300 and 23 200 cm−1, respectively, as well as four weak trip–multiplet transitions are observed at 8650, 12 000, 14 900 and 19 900 cm−1.
Synthesis, X-Ray Crystal Structure and Reactivity of Dichloro(phthalocyaninato)niobium(IV) (New Polymorph) and Trichloro(phthalocyaninato)niobium(V)
Authors: CELLUCCI LUCIA , ERCOLANI CLAUDIO , LUKES PETER J. , CHIESI-VILLA ANGIOLA , RIZZOLI CORRADO
Published: September 2002

Dichloro(phthalocyaninato)niobium(IV), PcNbCl2, has been isolated as a new polymorph and its X-ray crystal structure solved. Crystals are triclinic: formula C32H16Cl2N8Nb , space group P1, cell parameters a = 8.707(2) Å, b = 12.288(3) Å, c = 12.801(3) Å, α = 80.72(2) °, β = 85.43(2) °, γ = 76.62(2) °, V = 1313.7(6) Å3, Z = 2. The molecular structure closely resembles that already found for the monoclinic polymorph. Thus, Nb ( IV ) is six-coordinated in a cis arrangement, being displaced out of the inner N4square planar system of the phthalocyanine ring by 0.898(1) Å, towards the two chlorine atoms (average Nb - N (Pc) bond distance: 2.130(15) Å; Nb-Cl bond distances: 2.408(1) and 2.396(1) Å; angle Cl1-Nb-Cl2: 80.7 °). The main difference between the two polymorphs is the different stacking of the molecules in the crystal lattice. PcNbCl3is also triclinic: formula C32H16Cl3N8Nb , space group P1, cell parameters a = 12.086(2) Å, b = 13.710(2) Å, c = 8.345(1) Å, α = 93.49(2) °, β = 100.95(2) °, γ = 79.79(2) °, V = 1335.6(4)Å3, Z = 2. In the molecular structure the Pc chromophore and the three chlorine atoms are at opposite sites with respect to the Nb atom, which is seven coordinate (average Nb-N (Pc) bond distance: 2.178(5) Å; Nb-Cl bond distances: 2.482(1), 2.426(1) and 2.380(1) Å; angles Cl-Nb-Cl : 85.3(0), 80.3(0), and 76.5(0) °). The stability of PcNbCl2and PcNbCl3towards water has been examined. The reactivity of PcNbCl2with pyrocathecol, oxalic acid, H2SO4and iodine has also been examined and has led to the isolation and characterization of the following Nb ( IV ) and Nb ( V ) species: PcNbIV(cat), PcNbIV(oxal), PcNbIVSO4, PcNbVCl2I , PcNbV(cat)I.
Influence of Surfactant-based Microheterogeneous Fluids on Aggregation of Copper Phthalocyanine Tetrasulfonate
Authors: ZELINA JOHN P. , NJUE CHRISTOPHER K. , RUSLING JAMES F. , KAMAU GEOFFREY N. , MASILA MIRIAM , KIBUGU JULIUS
Published: September 2002

Electronic absorption spectroscopy was used to measure the molecular association of copper phthalocyanine tetrasulfonate in micellar solutions, a microemulsion made with cationic surfactant, and homogeneous solvents. Analysis of absorbance versus concentration data using a multiple-aggregation model and non-linear regression analysis gave values of association constants, molar absorptivities and estimates of average aggregation number. Microemulsions and aqueous micellar solutions made with alkylammonium surfactants inhibited aggregation, probably because of interactions between the phthalocyanine sulfonate groups and the cationic surfactant head groups at interfacial surfaces. Similar aggregation behavior was observed previously in multiple-bilayer films of cationic surfactants. Water and aqueous solutions containing tetraethylammonium bromide or anionic SDS micelles provide environments facilitating extensive aggregation of Cu II PcTS 4−. The major species are dimers in water and acetonitrile/water, but the formation of higher aggregates is promoted by addition of SDS or TEAB. Aprotic organic solvents provide environments intermediate between these two extremes, giving relatively large aggregation numbers (i.e. five to seven) but smaller association constants than aqueous media not containing cationic surfactants.
Discotic Liquid Crystals of Transition metal Complexes 23: Synthesis and Mesomorphism of Tetrakis(3,4-di-n-alkylphenyl)porphyrin Derivatives and Their Metal Complexes
Authors: OHTA KAZUCHIKA , ANDO MASAHIRO , YAMAMOTO IWAO
Published: September 2002

Five novel long-chain-substituted porphyrin derivatives, tetrakis(3,4-dialkylphenyl)porphyrins (abbreviated as (Cn)8 TPPH 2 (n = 8, 12, 18), ( C 18)8 TPPCu and ( C 18)8 TPPNi ), were synthesized and their mesomorphism was investigated. It was found that the (Cn)8 TPPH 2 (n = 8, 12), derivatives are isotropic liquids at room temperature and that each of the ( C 18)8 TPPM ( M ≡ H 2, Cu , Ni ) derivatives has two liquid crystal phases M1 and M2 and two unidentified phases X1 and X2. It was revealed by X-ray studies that the M2 phase is a discotic lamellar (DL) phase. Interestingly, these porphyrin derivatives exhibit not a columnar but a lamellar mesophase, even though they have a disk-like central core with eight alkyl chains in the surroundings.
Investigation of MALDI-TOF Mass Spectrometry of Diverse Synthetic Metalloporphyrins, Phthalocyanines and Multiporphyrin Arrays
Authors: SRINIVASAN N. , HANEY CAROL A. , LINDSEY JONATHAN S. , ZHANG WENZHU , CHAIT BRIAN T.
Published: September 2002

We investigated the utility of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) for analyzing porphyrinic compounds using a variety of different synthetic porphyrins, azaporphyrins, phthalocyanines and multiporphyrin arrays. Comparisons of spectra obtained from these analytes deposited either as neat samples or codeposited with neutral or acidic matrices have been made with the goal of identifying conditions that yield minimal demetalation, transmetalation, adduct formation and fragmentation. It was found that the molecular masses of many porphyrins can be successfully measured from neat sample preparations and do not require a matrix to facilitate desorption and ionization, although the measurement of large multiporphyrin arrays was facilitated by the use of matrices. Demetalation of magnesium porphyrins occurred in the presence of acidic matrices, but not with neutral matrices such as 1,4-benzoquinone. Positive ion spectra were obtained for each compound and negative ion spectra were also collected for the azaporphyrins and phthalocyanines. Examination of selected samples (prepared neat, with 1,4-benzoquinone, 2,3,5,6-tetrachloro-1,4-benzoquinone or α-cyano-4-hydroxycinnamic acid) showed that the dominant process of ionization involved oxidation yielding the radical cation M+· rather than the protonated molecule [M+H]+. MALDI-TOF-MS is shown to be a powerful analytical tool for the characterization of diverse synthetic porphyrinic compounds.
Heme protein biosensors
Authors: CHAN MICHAEL K.
Published: September 2002

The recent discovery that heme proteins can serve as molecular biosensors has opened up a new direction in heme biochemistry directed towards elucidating their structure-function relationships. Examples of such sensory heme proteins include the FixL proteins of Rhizobia involved in oxygen sensing, the CooA protein of Rhodospirillum rubrum that senses CO, and the mammalian soluble guanylate cyclase—the only proven nitric oxide receptor. This overview summarizes the current state of knowledge regarding the roles and mechanisms of these novel proteins and discusses the evidence for other putative heme protein sensors. These topics will be presented in the Heme Protein Biosensors Symposium at the First International Conference of Porphyrins and Phthalocyanines in Dijon, France.
Experimental modelling and intelligent control of a wood‐drying kiln
Authors: Yan Givon Chuen Kee , De Silva Clarence W. , Wang Xiaochun G.
Published: September 2002

Proper control of the wood‐drying kiln is crucial in ensuring satisfactory quality of dried wood and in minimizing drying time. This paper presents the development, implementation, and evaluation of a control system for a lumber drying kiln process incorporating sensory feedback from in‐wood moisture content sensors and intelligent control such that the moisture content of lumber will reach and stabilize at the desired set point without operator interference. The drying process is difficult to model and control due to complex dynamic nonlinearities, coupling effects among key variables, and process disturbances caused by the variation of lumber sizes, species, and environmental factors. Through system identification scheme using experimental data and recursive least‐squares algorithm for parameter estimation, appropriate models are developed for simulation purpose and controller design. Two different control methodologies are employed and compared: a conventional proportional‐integral‐derivative (PID) controller and a direct fuzzy logic controller (FLC), and system performance is evaluated through simulations. The developed control system is then implemented in a downscaled industrial kiln located at the Innovation Centre of National Research Council (NRC) of Canada. This experimental set‐up is equipped with a variety of sensors, including thermocouples for temperature feedback, an air velocity transmitter for measuring airflow speed in the plenum, relative humidity sensors for measuring the relative humidity inside the kiln, and in‐wood moisture content sensors for measuring the moisture content of the wood pieces. For comparison, extensive experimental studies are carried out on‐line using the two controllers, and the results are evaluated to tune the controller parameters to achieve good performance in the wood‐drying kiln. The combination of conventional control with the intelligent control promises improved performance. The control system developed in this study may be applied in industrial wood‐drying kilns, with a clear potential for improved quality and increased speed of drying. Copyright © 2001 John Wiley & Sons, Ltd.
Two common genetic thrombotic risk factors: Factor V Leiden and prothrombin G20210A in adult Turkish patients with thrombosis
Authors: Gurgey A. , Haznedaroglu I.C. , Egesel T. , Buyukasık Y. , Ozcebe O.I. , Sayınalp N. , Dundar S.V. , Bayraktar Y.
Published: September 2002

The prevalence of genetic risk factors for thrombosis varies greatly in different parts of the world, both in patients with thrombosis and in the general population. Factor V Leiden (FVL) and prothrombin G20210A (PT G20210A) mutations are the most common genetic defects leading to thrombosis. We have previously reported that those two thrombotic risk alleles are frequently found in Turkish children with thrombosis. The aim of the present study was to investigate the frequency of FVL and PT G20210A and their clinical manifestations in adult Turkish patients with thrombosis. Between January 1997 and February 2000, 146 patients with documented thrombosis were investigated in our center for the presence of the FVL and PT G20210A mutations. Forty‐five of 146 patients with thrombosis (30.8%) were detected to have FVL mutation. Among those cases with the FVL mutation, seven (4.8%) had homozygote and 38 (26%) had heterozygote mutation. The PT G20210A mutation was detected in 10 of the 146 patients with thrombosis (6.8%). Another six cases (4.1%) had both FVL and PT G20210A mutations. The overall frequency of these two common risk alleles in our adult population with thrombosis was 41.6%. Our findings reveal that FVL and PT G20210A mutations are significant genetic risk factors contributing to the pathophysiology of thrombosis in the Turkish population. Am. J. Hematol. 67:107–111, 2001. © 2001 Wiley‐Liss, Inc.
High‐dose cytosine arabinoside and idarubicin treatment of chronic myeloid leukemia in myeloid blast crisis
Authors: Barone Steven , Baer Maria R. , Sait Sheila N.J. , Lawrence David , Block AnneMarie W. , Wetzler Meir
Published: September 2002

Chronic myeloid leukemia in myeloid blast crisis (CML‐MBC) is highly resistant to standard induction chemotherapy regimens. Anecdotal results from previous clinical trials support the concept of dose escalation in patients with CML‐MBC. Eight patients with CML‐MBC were treated with cytosine arabinoside (Ara‐C) 1.5–3.0 g/m2 intravenously over 1 hr every 12 hr for 12 doses and idarubicin 12 mg/m2 intravenously daily for 3 days. Sixteen previous reports describing the use of Ara‐C‐based chemotherapy regimens in patients with CML‐MBC were also reviewed. Our patients' median age was 62 years (range, 42–69 years). One patient achieved complete hematologic remission (95% confidence interval, 0.3%, 53%).

The median survival for our patients was 7.3 months. These results were not different from previous published reports using Ara‐C‐based chemotherapy regimens to treat CML‐MBC. In summary, the combination of high‐dose Ara‐C and idarubicin did not improve the overall prognosis of patients with CML‐MBC. Innovative approaches need to be explored for this patient population. Am. J. Hematol. 67:119–124, 2001. © 2001 Wiley‐Liss, Inc.
Increased levels of tissue factor pathway inhibitor may reflect disease activity and play a role in thrombotic tendency in Behçet's disease
Authors: Akarsu Mesut , Demirkan Fatih , Özsan G. Hayri , Önen Fatos , Yüksel Faize , Özkan Sebnem , Ündar Bülent
Published: September 2002

Tissue factor pathway inhibitor (TFPI) is a Kunitz‐type proteinase inhibitor that has a crucial role in haemostasis and is primarily synthesized in the vascular endothelium. We investigated plasma total TFPI, antiphospholipid antibodies, and some other coagulation and fibrinolytic system parameters in 30 patients with Behçet's disease and 15 controls by the enzyme‐linked immunosorbent assay method. TFPI levels were significantly higher in the Behçet's group (119 ± 57.5 ng/ml) compared with the control group (74.8 ± 31.5) (P < 0.009). We also noted a statistical significance in TFPI levels between patients with active disease (n:16) (139 ± 55) and patients without activation (n:14) (96 ± 53) (P < 0.03), whereas inactive patients lacked any significance when compared with the control group (P < 0.29). Other parameters disclosed no statistical significance between patients and control group except for elevated fibrinogen and plasminogen activator inhibitor‐1 levels in the patient group (P < 0.003). Increased levels of TFPI may reflect a defensive mechanism like in other diseases characterized by thrombotic tendency and represent a parameter of disease activity. Am. J. Hematol. 68:225–230, 2001. © 2001 Wiley‐Liss, Inc.