bluuebunny/crossref_metadata_2025 huggingface dataset:
Shear‐induced change of exfoliation and orientation in polypropylene/montmorillonite nanocomposites
Authors: Zhang Qin , Wang Yong , Fu Qiang
Published: December 2002

For the improved dispersion of montmorillonite (MMT) in a polypropylene (PP) matrix, PP/MMT nanocomposites prepared via direct melt intercalation were further subjected to oscillating stress achieved by dynamic packing injection molding. The shear‐induced morphological changes were investigated with an Instron machine, wide‐angle X‐ray diffraction, scanning electron microscopy, and transmission electron microscopy. The original nanocomposites possessed a partly intercalated and partly exfoliated morphology. A transformation of the intercalated structure into an exfoliated structure occurred after shearing, and a more homogeneous dispersion of MMT in the PP matrix was obtained. However, the increase of the exfoliated structure was accompanied by the scarifying of the orientation of MMT layers along the shear direction. Some bended or curved MMT layers were found for the first time by TEM after shearing. However, the orientation of PP chains in the PP/MMT nanocomposites became very difficult under an external shear force; this indicated that the molecular motion of PP chains intercalated between MMT layers was highly confined. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 1–10, 2003
Correlation between melting behavior and ringed spherulites in poly(trimethylene terephthalate)
Authors: Wu Pi‐Ling , Woo E. M.
Published: December 2002

The lamellar types as revealed by the multiple melting peaks and possible mechanisms of ringed spherulites in poly(trimethylene terephthalate) (PTT) were analyzed with differential scanning calorimetry (DSC), optical microscopy, and scanning electron microscopy. Several interesting correlations were found. If PTT is melt‐crystallized in a certain temperature range, it shows multiple melting peaks and rings in PTT. Once rings are formed in the original melt‐crystallized PTT, they do not disappear but persist and become even more apparent upon postcrystallization annealing at higher temperatures. Furthermore, for PTT that is capable of exhibiting ringed spherulites, a temperature range exists where rings do not form. This behavior can be interpreted in relation with the demonstrated thermal behavior in PTT. Reorganization took place upon postcrystallization scanning or annealing to or at higher temperatures. A postulation was proposed and rigorously tested with evidence to correlate the ringed spherulites and melting behavior. Rings in PTT may be related to multiple lamellae in the spherulites. Consequently, if a temperature of crystallization is selected so that there is only one type of lamella in the spherulites, then there should be no rings. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 80–93, 2002
Conductivities and spectroscopic studies on hyperbranched polyurethane electrolytes
Authors: Hong Ling , Cui Yanjun , Wang Xinling , Tang Xiaozhen
Published: December 2002

Polymer electrolytes were prepared with hyperbranched polyurethane, linear polyurethane as the host polymer, and lithium perchlorate (LiClO4) as the ion source. Fourier transform infrared spectra were used to analyze the bonding degree of Li+ with carbonyl and ether groups. Raman spectra were applied to analyze the aggregate degree of anion perchlorate ion (ClO). The spectra analysis indicated that the hyperbranched polyurethane could function as a “solvent” for the lithium salt. Also, the conductivity increased with increasing concentration of hyperbranched polymers in the host polymer. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 120–126, 2003
Effect of silane coupling agent on mechanical interfacial properties of glass fiber‐reinforced unsaturated polyester composites
Authors: Park Soo‐Jin , Jin Joong‐Seong
Published: December 2002

A silane coupling agent, γ‐methacryloxypropyltrimethoxysilane, for the surface modification of glass fibers was varied between 0.1 and 0.8 wt %. To understand the role of interfacial adhesion of glass fiber/unsaturated polyester composites, contact angles of the silane‐treated glass fibers were measured by the wicking method on the basis of the modified Washburn equation with deionized water, diiodomethane, and ethylene glycol as testing liquids. As a result, silane‐treated glass fibers led to increased surface free energy, mainly because of their increased specific or polar component. The mechanical interfacial behaviors based on the interlaminar shear strength (ILSS) of the composites determined by short‐beam tests and the critical stress‐intensity factor (KIC) were also improved in the case of silane‐treated composites. The surface free energy and the mechanical interfacial properties especially showed the maximum value in the presence of 0.4 wt % silane coupling agent. It revealed that the increase of a specific component of the surface free energy or hydrogen bonding between the glass fibers and the coupling agents plays an important role in improving the degree of adhesion at interfaces in a composite system. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 55–62, 2003
Inhibitory effect of chlorophyllin on the frequency of micronuclei induced by sodium nitrite in mice
Authors: Diaz‐Barriga Arceo S. , Hernández‐Ceruelos A. , Madrigal‐Bujaidar E. , Chamorro G.
Published: December 2002

In this report the potency of chlorophyllin (CHL) was evaluated to prevent two types of damage produced by nitrite in mice: the increase of micronucleated polychromatic erythrocytes (MNPE) and the bone marrow toxicity, measured as the index of polychromatic erythrocytes/normochromatic erythrocytes (PE/NE). The study was done in eight groups of male mice. The first three groups were administered orally for 4 days with sodium nitrite (10, 15 and 20 mg/kg), the daily administration with nitrite was followed by an intraperitoneal administration of CHL (4 mg/kg), three more groups were administered with the same amounts of nitrite, a seventh group of mice was treated with distilled water while another was treated with CHL (4 mg/kg). Our study produced two main results: (a) no bone marrow injury was induced by any of the tested chemicals, as indicated with the PE/NE index, and (b) CHL protected (as high as 44%) the MNPE produced in nitrite treated mice. Copyright © 2002 John Wiley & Sons, Ltd.
The effects of chard (Beta vulgaris L. var. cicla) extract on the kidney tissue, serum urea and Creatinine levels of diabetic rats
Authors: Yanardağ R. , Bolkent Ş. , Özsoy‐Saçan Ö. , Karabulut‐Bulan Ö.
Published: December 2002

The aim of this work was to investigate the effects of chard (Beta vulgaris L. var. cicla) extract on serum urea and creatinine concentrations and on kidney tissue in normal and streptozotocin‐diabetic rats. The extract was administered to rats at a dose of 2 g/kg every day for 28 days, 14 days after animals were made diabetic. On day 42, kidney tissue and blood samples were examined. Significant degenerative changes in kidney tissue of diabetic rats were observed, but in the group given chard extract, the morphology of kidney tissue was found to be nearly the same as the controls. Serum urea and creatinine levels significantly increased in the diabetic groups, but the chard extracts significantly reduced serum urea and creatinine levels. It is concluded that the extract of this plant may reduce serum urea and creatinine levels and confer a protective effect on the kidney of diabetic rats. Copyright © 2002 John Wiley & Sons, Ltd.
Perceived sources of occupational stress among Chinese off‐shore oil installation workers
Authors: Wong Tze‐Wai , Chen Wei‐Qing , Yu Tak‐Sun , Lin Yan‐Zu , Cooper Cary L.
Published: December 2002

To explore the perceived sources of occupational stress and their relative importance among Chinese off‐shore oil installation workers, we used a self‐administered questionnaire to study 51 stressors associated with off‐shore oil work among 561 Chinese workers in a state‐owned oil company. The mean scores of 51 individual stressors were calculated and ranked. Factor analysis was used to identify nine sources of stress which were also ranked according to their standard mean scores. The top four sources of stress were, in descending order of importance: ‘physical environment of the workplace’, ‘safety’, ‘interface between job and family/social life’ and ‘career and achievement’. The perceived sources of work stress in Chinese workers were different from those reported in earlier studies on UK off‐shore oil workers. These differences might be attributable to socio‐cultural factors or possibly, changes in perception to stress over time. A better understanding of the sources of stress is essential to promote the physical and mental health of off‐shore oil workers. More cross‐cultural comparative studies would be useful in elucidating the influence of socio‐cultural and environmental factors on stress perception. Copyright © 2002 John Wiley & Sons, Ltd.
Work and personal resources as long‐term predictors of well‐being
Authors: Kalimo Raija , Pahkin Krista , Mutanen Pertti
Published: December 2002

The aim of this longitudinal study was to recognize the work and personal factors that predict well‐being in the long run. The empirical analyses are based on sample data from a larger survey in 1986 and from the 10‐year follow‐up. Well‐being was determined in terms of psychological and physiological symptoms of strain. Discriminant analysis was used to identify the predictor variables which best characterize the differences between the extreme strain groups. Differences were observed in the strength of work and personal resources between workers with low and high strain, and in the role of these resources in the process of staying well at work. Strong personal resources, especially strong sense of coherence, seem to protect workers from strain and thus maintain well‐being. At work, factors related to social processes, i.e. social support and appreciation from colleagues and superiors, act as primary work‐related resources. In general, the personal resources were better discriminating factors than the work characteristics. Well‐being was found to be relatively stable. Copyright © 2002 John Wiley & Sons, Ltd.
Varieties of competitive parity
Authors: Powell Thomas C.
Published: December 2002

Strategy research explains why some firms outperform others, typically using profit rates, shareholder returns, and other continuous dependent variables. This paper investigates winning as the dependent variable, as measured by distributions of annual industry leadership in profits and returns to investors. This shift in dependent variable introduces alternative null models of competitive parity, including skew distributions derived from the natural sciences, and empirical distributions from nonbusiness domains such as chess, politics, sports, and beauty pageants. An empirical study of 20‐year leadership in U.S. industries shows that performance distributions in business follow statistical power laws resembling those in natural phenomena, and closely resemble distributions found in sports, politics, and other nonbusiness domains. The results support a presumption of persistent performance advantages in business, but show that business outcomes are indistinguishable from outcomes in the wider scientific and competitive landscape, and are amenable to explanation using relatively simple heuristics. The paper shows how the choice of null model shapes firm performance explanations, and explores the consequences of a more inclusive approach to null models in strategy research. Copyright © 2002 John Wiley & Sons, Ltd.
Domestic violence during pregnancy in Rio de Janeiro, Brazil
Authors: Moraes C.L , Reichenheim M.E
Published: December 2002

Objectives: To estimate the prevalence and risk groups of domestic violence during pregnancy among public health care users in Rio de Janeiro, Brazil. The study focuses on violence perpetrated by both women and partners. Method: 526 women giving birth at term in public maternities from March to October 2000 were randomly selected and interviewers used the Revised Conflict Tactics Scales (CTS2). Results: 33.8% [95% confidence interval (CI): 28.8–37.0%] of the respondents reported some form of physical violence and 16.5% (95% CI: 13.3–19.8%) referred to severe forms. A total of 78.3% (95% CI: 74.8–81.8%), 9.9% (95% CI: 7.5–12.7%) and 15.6% (95% CI: 12.6–18.9%) reported psychological aggression, sexual coercion and injuries, respectively. Physical violence mainly occurred among adolescent women with less schooling, who did not work outside the home, with fewer prenatal appointments, and with little social support. Families with more under‐five children, alcohol and drug abuse, and low socio‐economic status were also involved more frequently. Conclusion: High prevalence rates for various forms of domestic violence in Brazil suggest that the issue should be viewed as a major public health problem.
Prenatal course and pregnancy outcome of fetuses with a transient nuchal translucency
Authors: Fukada Y , Amemiya A , Kohno K , Sunami R , Kobayashi Y , Hoshi K
Published: December 2002

Objectives: This study was designed to correlate fetuses in a normal prenatal population who exhibited transient nuchal translucency (NT) with both prenatal course and pregnancy outcome. Methods: The fetuses with abnormal NT were followed by ultrasonography at 1–2‐week intervals during their prenatal course. Fetuses with NT who exhibited no detectable congenital malformations were defined as the NTO group; fetuses with abnormal NT and structural malformations but no chromosomal abnormalities were placed in the SM group; and fetuses with abnormal NT, structural malformations, and chromosomal abnormalities were categorized as the CA group. The groups were compared by: maternal age, weeks of gestation by ultrasound and the NT value at the initial exam, the maximum NT value, and the duration of abnormal NT. Results: During the study period, 92 fetuses with abnormal NT were found, monochorionic twins excluded. Of the 92 fetuses, 80 were in the NTO group, 10 were in the SM group, and two were in the CA group. The maternal age and the gestational weeks at the initial diagnosis were not significantly different in the NTO and the SM groups. However, the NT value at the initial diagnosis, maximum NT value, and the duration of abnormal NT were significantly greater in the SM group than those values in the NTO group. Conclusions: Fetuses with transient nuchal translucency commonly had structural malformations, particularly fetuses with significant and large persistent NT.
Helicobacter pylori seropositivity in patients with hyperemesis gravidarum
Authors: Kazerooni T , Taallom M , Ghaderi A.A
Published: December 2002

Objectives: To test the hypothesis that infection with Helicobacter pylori is associated with hyperemesis gravidarum. Methods: From November 1999 to February 2001, we enrolled 54 pregnant women with hyperemesis gravidarum and 53 asymptomatic pregnant women in a prospective study. Specific serum immunoglobulin G for Helicobacter pylori was assayed in the sera of the study group and compared with the asymptomatic group. Chi‐square and Student's t‐test were used accordingly for statistical analysis of the data. Results: Serologically positive Helicobacter pylori infection was detected in 44 out of 54 patients with hyperemesis gravidarum (81.5%) whereas 29 out of 53 asymptomatic gravidas (54.7%) had positive antibody titers for Helicobacter pylori. The ratio of Helicobacter pylori seropositivity in pregnant women with hyperemesis gravidarum was significantly higher than asymptomatic pregnant women (P<0.01). The mean (±S.D.) of the IgG titer was 69.7 (±77.5) in the hyperemesis gravidarum group and 34.5 (±47.8) in the control group (P<0.01). Conclusions: There is a significant association between Helicobacter pylori infection and hyperemesis gravidarum in our hyperemetic pregnant patients.
Radiation and your patient: A guide for medical practitioners
Authors: Valentin J.
Published: December 2002

This didactic text is devoted to the protection of patients against unnecessary exposure to ionising radiation. It is organised in a questions-and-answers format.

There are obvious benefits to health from medical uses of radiation, in x-ray diagnostics, interventional radiology, nuclear medicine, and radiotherapy. However, there are well-established risks from high doses of radiation (radiotherapy, interventional radiology), particularly if improperly applied, and possible deleterious effects from small radiation doses (such as those used in diagnostics). Appropriate use of large doses in radiotherapy prevents serious harm, but even low doses carry a risk that cannot be eliminated entirely. Diagnostic use of radiation requires therefore such methodology that would secure high diagnostic gains while minimising the possible harm.

For assessment of the risk, a quantitative measure of exposure is a necessary prerequisite. Therefore, dosimetric quantities are explained and defined (absorbed dose, effective dose). Basic facts are presented on mechanisms of action of ionising radiations on living matter. Undesired deleterious effects in man are categorised into two categories. The first one comprises sequelae resulting from massive cell killing (the so-called deterministic effects), requiring a high dose for their manifestation (exceeding the threshold dose). The second category includes those effects originating from mutational changes in the cellular DNA. These may eventually lead to development of radiation-induced cancer and to hereditary changes, transmitted to descendants of exposed individuals after irradiation of their gonads.

Data on the magnitude of threshold doses for cell killing effects are presented. On the basis of experimental, clinical, and epidemiological evidence, assessment is also given of the probability with which cancers and hereditary mutations may be induced by doses of various magnitudes, most likely without a threshold dose (below which no effect would obtain).

The text provides ample information on opportunities to minimise doses, and therefore the risk from diagnostic uses of radiation. This objective may be reached by avoiding unnecessary (unjustified) examinations, and by optimising the procedures applied both from the standpoint of diagnostic quality and in terms of reduction of the excessive doses to patients.

Optimisation of patient protection in radiotherapy must depend on maintaining sufficiently high doses to irradiated tumours, securing a high cure rate, while protecting the healthy tissues to the largest extent possible. Problems related to special protection of the embryo and fetus in the course of diagnostic and therapeutic uses of radiation are presented and practical solutions are recommended.

This issue of the Annals of the ICRP also includes a brief report concerning Diagnostic Reference Levels in medical imaging: Review and additional advice.
Role of the Crumbs complex in the regulation of junction formation in Drosophila and mammalian epithelial cells
Authors: Médina Emmanuelle , Lemmers Céline , Lane‐Guermonprez Lydie , Le Bivic André
Published: December 2002

The formation of a belt‐like junctional complex separating the apical from the lateral domain is an essential step in the differentiation of epithelial cells. Thus protein complexes regulating this event are of first importance for the development of cell polarity and physiological functions of epithelial tissues. In Drosophila, the discovery of a gene, crb, controlling the coalescence of the spots of zonula adherens (ZA) into a adhesive ring around the cells was a major step. We know now that Crumbs, the product of crb is an apical transmembrane protein conserved in mammals and that it interacts by its cytoplasmic domain with two cortical modular proteins, Stardust (Sdt) and Discs lost (Dlt) that are also essential for the correct assembly of the ZA. These two proteins are also conserved in mammals and it is most likely that the Crumbs complex plays a similar role in very different species. Recently, we have shown that Crumbs interacts with the cortical cytoskeleton made of DMoesin and βheavy‐Spectrin and this connection could explain in part the role of Crumbs in building the ZA. Future work will help to understand several aspects of the Crumbs complex that are still unknown, like the role of the large extracellular domain or the precise function of Sdt and Dlt in the building of the ZA. Finding an answer to these questions will help to find new therapies for Retinitis pigmentosa and other retina degeneration in which CRB1, the human homologue of crb, has been involved.
Cadherin‐based cell adhesion in neuromuscular development
Authors: Marthiens Véronique , Gavard Julie , Lambert Mireille , Mège René Marc
Published: December 2002

The organisation and differentiation of striated skeletal muscles and their innervation is a particularly complex process implicating cells of mesodermic (myoblasts and fibroblasts) and neuroectodermic origin (neurons and glial cells). Myogenic and motor neuron precursors, the two major cell types participating in the formation of the neuromuscular axis, migrate, segregate, reassociate and differentiate in a coordinated fashion. The subsequent organisation of muscle cells and the establishment of muscle innervation rely on a complex tissular and cellular architectural organisation, which cannot be understood without taking into account juxtacrine cell interactions, and especially cell adhesion. Cell adhesion receptors of the cadherin family are widely expressed and dynamically regulated in space and time throughout neuromuscular development. A single cell expresses in general more than one cadherin at its surface and it is the combination of these molecules and their level of expression that determine their action within a given cell population. We focused in this review on the expression and roles of classical cadherins in relation to muscle cell and motoneuron differentiation. We also review the latest results on the mode of action of cadherins allowing to propose cellular and molecular cues on the mechanisms by which these cell adhesion receptors control muscle and neuronal cell shape, migration and differentiation.
Elemental characterization of microorganism granules by EFTEM in the tube wall of a deep‐sea vent invertebrate
Authors: Lechaire Jean‐Pierre , Shillito Bruce , Frébourg Ghislaine , Gaill Françoise
Published: December 2002

Microorganisms colonizing the exoskeletons of the tube worm Riftia pachyptila are described at the ultrastructural level. The prokaryotic cells from the worm tube wall differ from those colonizing the exoskeleton outer surface in the presence of an electron dense granule. The morphology and distribution of these bacteria‐like cells are described. Prokaryotic organisms are assembled in nodules which increased in size in the oldest part of the exoskeleton. The aspect, location and elemental composition of the intracellular granules are determined. Most of them (100 nm in diameter) are located close to the cell membrane and exhibit a homogeneous and amorphous content. EDX and EFTEM microanalyses show that these structures contain phosphorus, oxygen and iron. All together these data suggest that these granules are iron polyphosphates. These structures may act as energy sources for making ATP during anoxic conditions as existing in hydrothermal environments.
Nuclear transcription factor GATA‐1 is activated during aclacinomycin‐induced erythroid differentiation
Authors: Gillet Reynald , Bobichon Hélène , Trentesaux Chantal
Published: December 2002

Anthracycline antitumor drugs induce erythroid differentiation of the K562 erythroleukemic cell line at subtoxic concentrations. Aclacinomycin (ACM) stimulates this process by activating the erythroid transcription factor GATA‐1, that controls genes involved in hemoglobin biosynthesis. To investigate the implication of GATA‐1 in this process, we used a specific anti‐GATA‐1 polyclonal antibody that we produced in our laboratory. The GATA‐1 transcription factor was then monitored during erythroid differentiation induced by aclacinomycin. Here we show that a cellular redistribution and a modification of the phosphorylation state of this transcription factor occurred during ACM‐mediated cell differentiation. It suggests that anthracyclines can induce the erythroid differentiation of neoplastic cells by activating the transcription factor GATA‐1, probably via its clustering into nuclear foci.
Centrosome separation: respective role of microtubules and actin filaments
Authors: Uzbekov Rustem , Kireyev Igor , Prigent Claude
Published: December 2002

In mammalian cells, the separation of centrosomes is a prerequisite for bipolar mitotic spindle assembly. We have investigated the respective contribution of the two cytoskeleton components, microtubules and actin filaments, in this process. Distances between centrosomes have been measured during cell cycle progression in Xenopus laevis XL2 cultured cells in the presence or absence of either network. We considered two stages in centrosome separation: the splitting stage, when centrosomes start to move apart (minimum distance of 1 μm), and the elongation stage (from 1 to 7 μm). In interphase, depolymerisation of microtubules by nocodazole significantly inhibited the splitting stage, while the elongation stage was, on the contrary, facilitated. In mitosis, while nocodazole treatment completely blocked spindle assembly, in prophase, we observed that 55% of the centrosomes separated, versus 94% in the control. Upon actin depolymerisation by latrunculin, splitting of the interphase centrosome was blocked, and cells entered mitosis with unseparated centrosomes. Cells compensated for this separation delay by increasing the length of both prophase and prometaphase stages to allow for centrosome separation until a minimal distance was reached. Then the cells passed through anaphase, performing proper chromosome separation, but cytokinesis did not occur, and binuclear cells were formed. Our results clearly show that the actin microfilaments participate in centrosome separation at the G2/M transition and work in synergy with the microtubules to accelerate centrosome separation during mitosis.
Nucleus behavior during the closed mitosis of Tritrichomonas foetus
Authors: Ribeiro Karla Consort , Mariante Rafael Meyer , Coutinho Letícia Lopes , Benchimol Marlene
Published: December 2002

We present observations on the fine structure and the division process of the nucleus in the protist Tritrichomonas foetus, parasite of the urogenital tract of cattle. The nucleus was followed by immunofluorescence and electron microscopy during interphase and mitosis. Conventional karyotyping coupled to image processing and bright field Panotic staining were used to follow nucleus modifications, chromosome number and condensation pattern along the whole cell cycle. Confocal laser scanning microscopy (CLSM) using DNA fluorescent probes, followed by image processing in the SURF‐Driver program, produced three‐dimensional reconstruction data of the mitotic nucleus under each phase of the division process. Immunocytochemistry in thin‐sections revealed the chromosome spatial arrangement after bromodeoxyuridine incorporation and immunogold labeling using anti‐DNA monoclonal antibodies. Our results indicate that: (1) the nucleus assumes different size and shapes along mitosis: it appears oval in interphase, becoming lobed or concave in prophase, then undergoing torsion and constriction, displaying an ‘S’ shape (metaphase). Next, it becomes elongated and it is finally separated in two nuclei at the transition of anaphase to telophase; (2) T. foetus nucleus harbors five chromosomes; (3) chromosomes become condensed in a pre‐mitotic phase; (4) the nucleolus persists during the mitosis.
The natural course of DSM-IV somatoform disorders and syndromes among adolescents and young adults: a prospective-longitudinal community study
Authors: Lieb Roselind , Zimmermann Petra , Friis Robert H , Höfler Michael , Tholen Sven , Wittchen Hans-Ulrich
Published: December 2002

Objective.

Although somatoform disorders are assumed to be chronic clinical conditions, epidemiological knowledge on their natural course based on representative samples is not available.

Method.

Data come from a prospective epidemiologic study of adolescents and young adults in Munich, Germany. Respondents’ diagnoses (N = 2548) at baseline and follow-up on average 42 months later are considered. The follow-up incidence, stability as well as selected baseline risk factors (sociodemographics, psychopathology, trauma exposure) for the incidence and stability of somatoform disorders and syndromes are prospectively examined. Diagnostic information was assessed by using the standardized Munich-Composite International Diagnostic Interview (M-CIDI).

Results.

Over the follow-up period, incidence rate for any of the covered somatoform diagnoses was 25.7%. Stability for the overall group of any somatoform disorder/syndrome was 48%. Female gender, lower social class, the experience of any substance use, anxiety and affective disorder as well as the experience of traumatic sexual and physical threat events predicted new onsets of somatoform conditions, while stability was predicted by being female, prior existing substance use, affective and eating disorders as well as the experience of a serious accident.

Conclusions.

At least for a substantial proportion of individuals, the overall picture of somatization seems to be relatively stable, but with fluctuation in the symptom picture over time. Being female, the experience of substance use as well as anxiety disorder seem to constitute risk factors for the onset of new somatoform conditions as well as for a stable course over time.
Neuroleptic-induced dystonia: incidence and risk factors
Authors: Ballerini Massimo , Bellini Simona , Niccolai Carlo , Pieroni Valentina , Ferrara Maurizio
Published: December 2002

Retrospective evaluation of patients admitted consecutively to the psychiatric units of two general hospitals in Florence, to evaluate the rate and risk factors of neuroleptic-induced dystonia (NDA). One hundred and fifty-nine patients out of 2354 reviewed charts were included. The incidence of NDA was 15.7%. Multivariate analyses revealed that both age and neuroleptization speed (NS)—a new variable—were related to the occurrence of dystonia.
Early development and unstable genes in schizophrenia: preliminary results
Authors: Ayton Agnes , Morris Alex G. , Tyson Philip J. , Hunt David , Mortimer Ann M. , Cottrell David
Published: December 2002

Background.

Trinucleotide repeats have been associated with schizophrenia, but the evidence, based on cross-sectional clinical information, is equivocal.

Aims.

To examine the relationship between genomic CAG/CTG repeat size and premorbid development in schizophrenia.

Method.

Early development and premorbid functioning of 22 patients with DSM-IV diagnosis of schizophrenia were assessed by parental interviews. Repeat expansion detection (RED) technique was used to measure genomic CAG/CTG repeat size, and PCR for CAG repeat size at the ERDA-1 and CTG 18.1 loci.

Results.

There was an inverse association between CAG/CTG size and perinatal complications. Patients with speech and motor developmental delay had larger repeats. The results were not due to expansion in the ERDA-1 and CTG 18.1 genes.

Conclusions.

CAG/CTG repeat expansion is associated with speech and motor developmental delay in schizophrenia. We propose that the developmental model may be useful for research into the genetics of schizophrenia.
The Money Book of Personal Finance
Authors: Kahl Douglas
Published: December 2002

NA
Annual rates of admission and seasonal variations in hospitalizations for heart failure
Authors: Martínez‐Sellés Manuel , Robles José A. García , Prieto Luis , Serrano José A. , Muñoz Roberto , Frades Elisa , Almendral Jesús
Published: December 2002

Aims:

To investigate the annual hospitalization rate and seasonal variation in confirmed heart failure (HF) admissions.

Methods and Results:

Records from all admissions to one hospital during 1 year with a HF diagnostic code were reviewed. From 1953 admissions, 595 were excluded because they did not fulfill the diagnostic criteria. A total of 1069 patients had 1358 admissions with confirmed HF. Mean age was 74.8±11.5 years, 42% were males. The admission data were matched with data from the municipal census with 537 666 people aged ≥15 years. There were 2.5 admissions per 1000 for the adult population and 26.5/1000 in those aged ≥80 years. There were 444 males and 625 females, giving a higher rate of admission for female patients 2.2/1000 vs. 1.7/1000 (P<0.0001), although age adjusted rates in females were higher only for ≥80 years. Echocardiogram was performed in 706 patients (66%), 325 (46%) had a normal ejection fraction. This proportion increased in females—64% vs. 29% males—and in older patients—55% in ≥75 vs. 39% in <75 years. Mortality during the first admission of 1996 was 8.3%. There was a seasonal variation in HF hospitalizations (P<0.0001) peaking at 25% above average in January and dipping to 33% below average in August.

Conclusion:

The rate of HF admissions was 2.5/1000 with an elderly preponderance and a higher rate of admission in males <80 years and in females ≥80 years. A seasonal variation ranging from 25% above average in January to 33% below average in August was observed.
Combined effect of the force–frequency and length–tension mechanisms on left ventricular function in patients with dilated cardiomyopathy
Authors: Petretta Mario , Vicario Maria L.E. , Spinelli Letizia , Ferro Adele , Cuocolo Alberto , Condorelli Mario , Bonaduce Domenico
Published: December 2002

Background:

The myocardial length–tension and the force–frequency relations are important mechanisms that regulate the contractile strength of the heart.

Aims:

To evaluate in humans the effect on left ventricular function of the interaction between the myocardial length–tension and force–frequency relations.

Methods and results:

Eight patients with dilated cardiomyopathy (DCM) and 6 control subjects underwent radionuclide monitoring of left ventricular function during atrial pacing, saline loading and atrial pacing at the end of saline loading. In controls, atrial pacing reduced left ventricular end‐diastolic (P<0.001) and end‐systolic volumes (P<0.001) with no change in ejection fraction whereas after volume expansion end‐diastolic volume (P<0.001) and ejection fraction (P<0.001) increased. Atrial pacing after volume expansion increased ejection fraction (P<0.05). In patients with DCM, ejection fraction was reduced during atrial pacing (P<0.001) and volume expansion (P<0.05) due to an increase in left ventricular end‐systolic volume (P<0.001). Pacing tachycardia after volume expansion further increased end‐systolic volume and reduced ejection fraction with a significant ‘pacing by load’ interaction (P<0.001). Peak filling rate increased at each step in controls while it remained unchanged in patients with DCM.

Conclusion:

The heart rate increase during left ventricular distension improves ventricular function in normals and has detrimental effects in patients with DCM.
Time and frequency analysis of beat‐to‐beat R–T interval variability in patients with ischaemic left ventricular dysfunction providing evidence for non‐neural control of ventricular repolarisation
Authors: Sosnowski Maciej , Czyz Zbigniew , Tendera Michal
Published: December 2002

Background:

Determinants of temporal lability in ventricular repolarisation are not fully recognised. We aimed to analyse the sources of RT variability by comparing normal subjects and patients after myocardial infarction (MI) with either depressed or preserved left ventricular (LV) function.

Methods:

One hundred and nine patients (27 women, 82 men, aged 51±9 years) were divided into three groups: 24 patients (pts) with an uncomplicated angiographically proven coronary heart disease (CHD‐group), 59 post‐MI pts with preserved LV function (LVEF>40%, PMI‐N‐group) and 26 post‐MI pts with depressed LV function (LVEF<40%, PMI‐L‐group). An ECG signal of low‐noise 512 heartbeats was recorded using a computer‐assisted amplifier (16 bit, 2 kHz). The onset and offset of the R‐wave and T‐wave were determined automatically. The magnitude of R–R and R–T variability was measured as the standard deviation of all intervals (SD–RR and SD–RT, ms, respectively). Their relationship was quantified by the correlation coefficient rRT/RR. Power spectral density of RR or RT variability was estimated with the FFT (Welch's averaged periodogram, Hanning window) and frequency relation was quantified using a squared coherence spectrum (SCS). For all spectral and cross‐spectral measurements two frequency ranges were considered: high (0.15–0.50 Hz, HF) and low (0.04–0.15 Hz, LF). Spectral power and SCS of RR and RT variability for both ranges (HFRR, LFRR, HFRT, LFRT, SCSHF, SCSLF), and the ratios LF/HFRR and LF/HFRT were drawn for comparisons. The central frequency of HFRR was considered as the frequency of respiration (fresp, Hz).

Results:

In the PMI‐L group the SD–RT was significantly greater compared to the remaining groups and accounted for almost 10% of the SDRR. Also, the coefficient rRT/RR was weakest in this group. The spectral indices of RR variability were similar in all groups, while the greatest value of the HFRT was observed in the PMI‐L group. The SCSLF was insignificant in this group, contrary to the CHD and PMI‐N groups. Additionally, there were significant negative relationships between fresp and spectral indices of RT variability in PMI‐patients with depressed LV function.

Conclusion:

A greater beat‐to‐beat variation in RT interval duration along with increased power of its HF component indicates an important role of respiration in ventricular repolarisation control, while reduced time‐ and frequency RT–RR relationships seem to relate to an impaired process of ventricular duration adaptation.
Analysis of altered genomic expression profiles in the senescent and diseased myocardium using cDNA microarrays
Authors: Juhasz Ondrej , Zhu Yi , Garg Rahul , Anisimov Sergey V. , Boheler Kenneth R.
Published: December 2002

Cardiac function deteriorates with aging or disease. Short term, any changes in heart function may be beneficial, but long term the alterations are often detrimental. At a molecular level, functional adaptations involve quantitative and qualitative changes in gene expression. Analysis of all the RNA transcripts present in a cell's population (transcriptome) offers unprecedented opportunities to map these transitions. Microarrays (chips), capable of evaluating thousands of transcripts in one assay, are ideal for transcriptome analyses. Gene expression profiling provides information about the dynamics of total genome expression in response to environmental changes and may point to candidate genes responsible for the cascade of events that result in disease or are a consequence of aging. The aim of this review is to describe how comparisons of cellular transcriptomes by cDNA array based techniques provide information about the dynamics of total gene expression, and how the results can be applied to the study of cardiovascular disease and aging.
Effects of climate variability and disturbances on the Amazonian terrestrial ecosystems dynamics
Authors: Botta Aurélie , Foley Jonathan A.
Published: December 2002

This article examines how climate variability and ecological disturbances affect ecosystem composition and functioning in the Amazon region. We use a terrestrial ecosystem model, IBIS, and vary the treatment of climate (using either long‐term average climate, or actual historical variations in climate) and disturbances (with uniform disturbance rates applied through the region). Interannual climate variability and frequent disturbances both favor grasses over trees, causing large increases in the geographic extent of savanna in the south and east of the region. A more constant climate and less frequent disturbances both favor trees over grasses, causing forest to dominate most of the study area. While climate variability and disturbances have a major impact on ecosystem structure, we find that compensating processes between herbaceous and woody plants damp the simulated response of carbon and water fluxes. Nevertheless, the cumulative impact of these changes in vegetation structure results in significant changes in soil and vegetation carbon stocks (up to 36%).
Thick‐skinned tectonics in the external Apennines, Italy: New evidence from magnetic anomaly analysis
Authors: Speranza Fabio , Chiappini Massimo
Published: December 2002

We discuss the tectonic implications of a new residual magnetic map of the Apennine belt/Adriatic‐Apulian foreland obtained by integrating ground and offshore data sets [Chiappini et al., 2000a]. Negative anomalies are documented over the Adriatic‐Apulian foreland areas, whereas the external Apennine belt is characterized by a ubiquitous low‐amplitude (<30 nT), long‐wavelength positive anomaly. In the central northern Apennines, three ∼100 km wide more intense (100–200 nT) round‐shaped anomalies are superimposed to the long‐wavelength feature. Finally, in the Tyrrhenian Sea and margins, high‐intensity, short‐wavelength positive‐negative couplets coincide with magmatic outcrops or bodies at shallow depth. The low‐amplitude anomaly pattern over Italy suggests that the magnetic basement beneath the Triassic evaporites is ubiquitously incorporated in the external belt compressive fronts, implying a thick‐skinned tectonic style for the external Apennines. The new residual magnetic map resolves the inconsistency between previous aeromagnetic data [AGIP SpA. Italia, 1981], which suggested a lack of basement involvement in the Apennine belt, and recent seismic data, which imaged deep reflectors penetrating the basement. Two magnetic models along NE‐SW transects in the northern and southern Apennines suggest consistent structural styles. In the northern Apennines, positive anomalies roughly coincide with the external compressive fronts, although there are local second‐order differences between the belt front and the edges of the anomaly. Here the magnetic data show that the basement rises southwestward along the thrust fronts from 6–7 km depth in the Adriatic foreland to 2–3 km depth in the axial belt, where some exploration wells have penetrated basement. Within the belt front, basement exhumation is inferred to occur along high‐angle, low‐displacement thrust faults inverting preexisting normal faults. In the southern Apennines, a remarkable positive magnetic anomaly is parallel with and tens of kilometers southwest of the belt front. Seismic data and oil wells show that the basement surface cannot be shallower in the belt than in the foreland. Therefore the observed magnetic anomaly is produced by strongly magnetic basement beneath the belt, likely an internal crustal wedge tectonically interposed between the Apulian carbonate sequences and basement.
Apparent and true polar wander and the geometry of the geomagnetic field over the last 200 Myr
Authors: Besse Jean , Courtillot Vincent
Published: December 2002

We have constructed new apparent polar wander paths (APWPs) for major plates over the last 200 Myr. Updated kinematic models and selected paleomagnetic data allowed us to construct a master APWP. A persistent quadrupole moment on the order of 3% of the dipole over the last 200 Myr is suggested. Paleomagnetic and hot spot APW are compared, and a new determination of “true polar wander” (TPW) is derived. Under the hypothesis of fixed Atlantic and Indian hot spots, we confirm that TPW is episodic, with periods of (quasi) standstill alternating with periods of faster TPW (in the Cretaceous). The typical duration of these periods is on the order of a few tens of millions of years with wander rates during fast tracks on the order of 30 to 50 km/Myr. A total TPW of some 30° is suggested for the last 200 Myr. We find no convincing evidence for episodes of superfast TPW such as proposed recently by a number of authors. Comparison over the last 130 Myr of TPW deduced from hot spot tracks and paleomagnetic data in the Indo‐Atlantic hemisphere with an independent determination for the Pacific plate supports the idea that, to first order, TPW is a truly global feature of Earth dynamics. Comparison with numerical modeling estimates of TPW shows that all current models still fail to some extent to account for the observed values of TPW velocity and for the succession of standstills and tracks which is observed.
Fast late Pleistocene slip rate on the Leng Long Ling segment of the Haiyuan fault, Qinghai, China
Authors: Lasserre C. , Gaudemer Y. , Tapponnier P. , Mériaux A.‐S. , Van der Woerd J. , Daoyang Yuan , Ryerson F. J. , Finkel R. C. , Caffee M. W.
Published: December 2002

Fieldwork along the western Haiyuan fault, where it cuts young glacial landforms in the Leng Long Ling range (Qinghai, northeastern Tibet), yields new constraints on its long‐term left‐slip rate. Our mapping near 101.85°E, based on aerial photographs, 1/50,000 topographic maps, and SPOT images, shows glacial valley edges and lateral moraines offset ∼200 m by the fault. Quartz‐rich cobbles were sampled on top of one moraine for in situ 10Be and 26Al cosmogenic nuclide dating. Among 12 dated samples, the 6 oldest show ages clustering at 10,300 ± 339 years. This age probably reflects the time of last reshaping of the moraine before the valley glacier withdrew south of the fault around the end of the Younger Dryas (≃11,000 years B.P.). Assuming that the 200 ± 40 m moraine offset started to be recorded after glacial retreat across the fault constrains the late Pleistocene slip rate on the Leng Long Ling segment of the Haiyuan fault to be 19 ± 5 mm/yr.
Observations of surf beat forcing and dissipation
Authors: Henderson Stephen M. , Bowen A. J.
Published: December 2002

We used a simple energy balance equation, and estimates of the cross‐shore energy flux carried by progressive surf beat, to calculate the rate of net surf beat forcing (or dissipation) on a beach near Duck, North Carolina. Far inside the surf zone, surf beat dissipation exceeded forcing. Outside the surf zone, surf beat forcing exceeded dissipation. When incident waves were large, surf beat dissipation inside the surf zone and forcing just outside the surf zone were both very strong (the surf beat energy dissipated in the surf zone in a single beat period was of the same order as the total amount of surf beat energy stored in the surf zone). During storms, shoreward propagation of surf beat maintained surf beat energy in the surf zone. Net surf beat dissipation in the surf zone scaled as predicted by a simple bottom stress parameterization. The inferred dissipation factor for surf beat was 0.08, within the range of wave dissipation factors usually observed in the field and 27–80 times larger than drag coefficients appropriate for the mean longshore current. The observed rapid forcing, rapid dissipation, and shoreward propagation of surf beat are not simulated by existing models of surf beat dynamics.