bluuebunny/crossref_metadata_2025 huggingface dataset:
Population and African Society
Authors: Zuberi Tukufu , Sibanda Amson , Bawah Ayaga , Noumbissi Amadou
Published: September 2003

▪ Abstract  African society is quite distinct in both its relationship to the rest of the world and its history. Africa seems beset by a myriad of crises, from famines, to civil wars, to economic meltdowns. In addition to these crises, profound population and social change has occurred. These changes are having extraordinary socioeconomic, political, and cultural consequences. Africa's demographic regimes have also been profoundly affected by the HIV/AIDS epidemic, urbanization processes, and environmental change. This review focuses on how African population growth and urbanization are clashing with constraints unique to the twentieth and twenty-first centuries. We provide an empirical profile describing population growth and constraints to this growth and the improvement in the quality of life in Africa. We suggest that more attention needs to be placed on the structural aspects of population dynamics. Although this review makes some reference to North Africa, the focus is sub-Saharan Africa.
Associations and Democracy: Between Theories, Hopes, and Realities
Authors: Fung Archon
Published: September 2003

▪ Abstract  Over the past decade, there has been a resurgence of interest and research into the connections between associations and democracy. This article divides the question of associative contributions to democracy into four component parts: What (a) contributions do (b) different kinds of associations make to advance (c) contesting ideals of democratic governance in various (d) political contexts? Associations enhance democracy in at least six ways: through the intrinsic value of associative life, fostering civic virtues and teaching political skills, offering resistance to power and checking government, improving the quality and equality of representation, facilitating public deliberation, and creating opportunities for citizens and groups to participate directly in governance. These contributions are not all mutually consonant with one another, and different forms of associations are better suited to advance some contributions than others. Furthermore, those who propose bolstering associations as a strategy for revitalizing democracy frequently have quite different ideals of democracy in mind. The forms and contributions of associations appropriate to three contesting notions of democratic governance—liberal minimalism, conventional representation-cum-administration, and participatory democracy—are also discussed. Finally, the democratic priority of associative contributions depends crucially on contextual features of particular societies. Under tyrannical regimes, for example, associations that resist government authority are more crucial than those that foster compliance and respect for political institutions.
The Lopsided Continent: Inequality in Latin America
Authors: Hoffman Kelly , Centeno Miguel Angel
Published: September 2003

▪ Abstract  Latin America has the most unbalanced distribution of resources of all regions in the world. This review defines a set of common elements characterizing social structures on that continent, suggests some lines for analysis and theorizing, and supports the integration of regional studies into broader discussions of stratification. We begin with an overview of the situation on the continent as a whole, including a short discussion of the relationship between poverty and inequality, where we also address some concerns with data availability. We then devote a section each to class, gender, and race. We conclude by identifying three critical factors that explain Latin American inequality: its position within a global economic system, internal colonialism with maintenance of racial categories, and the underdevelopment of state structures.
Teenage Childbearing as a Public Issue and Private Concern
Authors: Furstenberg Frank F.
Published: September 2003

▪ Abstract  Teenage childbearing has been a topic of sociological research, public discourse, and political discussion since the mid-1960s. It is surprising that the intensity and topics of the discussion over this period have corresponded poorly with research on the rates and consequences of teenage childbearing. This essay chronicles the history of the issue of early childbearing and my contributions to this field of study.
Still “Not Quite As Good As Having Your Own”? Toward a Sociology of Adoption
Authors: Fisher Allen P.
Published: September 2003

▪ Abstract  Despite the fact that adoption is a common practice in the United States and in much of the world today, sociologists have devoted remarkably little attention to it. This review provides a rationale for much more extensive sociological research on adoption. It then summarizes the available empirical literature on who adopts children, and why, and on who relinquishes children for adoption, and why. Most adoptions have favorable outcomes for the members of the adoption triad (birth parents, adoptive parents, and adoptees). Yet the number of adoptions by nonrelatives has declined sharply since 1970, and only a small minority of women who have been treated for infertility have ever sought to adopt. These facts suggest that adoption may still have a stigma attached to it. Sociological research could illuminate whether such a stigma exists, and if so, what the causes and consequences of that stigma might be.
Beyond Rational Choice Theory
Authors: Boudon Raymond
Published: September 2003

▪ Abstract  Skepticism toward sociology has grown over recent years. The attention granted to rational choice theory (RCT) is, to a large extent, a reaction against this situation. Without doubt, RCT is a productive instrument, but it fails signally in explaining positive nontrivial beliefs as well as normative nonconsequential beliefs. RCT's failures are due to its move to use too narrow a definition of rationality. A model can be developed that combines the advantages of the RCT (mainly providing self-sufficient explanations), without falling victim to its shortcomings. This model is implicitly used in classical and modern sociological works that are considered to be illuminating and valid.
The Urban Street Gang after 1970
Authors: Coughlin Brenda C. , Venkatesh Sudhir Alladi
Published: September 2003

▪ Abstract  This review discusses research on the urban street gang after the 1960s, the period in which social scientists began to conceptualize the gang outside of the social-problems framework. Street-gang research has changed dramatically in the past three decades in accordance with general shifts in sociological research, including developments in gender studies, economic sociology, and race and ethnic relations. This review addresses these major trends and debates and highlights suggestions for areas of future inquiry that build on innovations of contemporary scholars.
The Science of Asking Questions
Authors: Schaeffer Nora Cate , Presser Stanley
Published: September 2003

▪ Abstract  Survey methodologists have drawn on and contributed to research by cognitive psychologists, conversation analysts, and others to lay a foundation for the science of asking questions. Our discussion of this work is structured around the decisions that must be made for two common types of inquiries: questions about events or behaviors and questions that ask for evaluations or attitudes. The issues we review for behaviors include definitions, reference periods, response dimensions, and response categories. The issues we review for attitudes include bipolar versus unipolar scales, number of categories, category labels, don't know filters, and acquiescence. We also review procedures for question testing and evaluation.
Variational approach to dynamics of bright solitons in lossy optical fibers
Authors: Mahmood M. F. , Brooks S.
Published: September 2003

A variational analysis of dynamics of soliton solution of coupled
nonlinear Schrödinger equations with oscillating terms is made, considering a birefringent fiber with a third‐order nonlinearity in the anomalous dispersion frequency
region. This theoretical model predicts optical soliton
oscillations in lossy fibers.
An equality for the curvature function of a simple and closed curve on the plane
Authors: Ou Biao
Published: September 2003

We prove an equality for the curvature function of a simple and
closed curve on the plane. This equality leads to another proof of the four‐vertex theorem in differential geometry. While examining the regularity assumption on the curve for the equality, we make comments on the relation between the boundary
regularity of a Riemann mapping and two important subjects, the Schauder theory and the strong maximum principle, for elliptic partial differential equations of second order. We take a note on the curvature function itself in recognizing people′s handwriting
by a calculating device, as an afterthought on the equality.
Para‐f‐Lie groups
Authors: Bucki Andrew
Published: September 2003

Special para‐f‐structures on Lie groups are studied. It is
shown that every para‐f‐Lie group G is the quotient of the
product of an almost product Lie group and a Lie group with
trivial para‐f‐structure by a discrete subgroup.
Jumping deformations of complete toric varieties
Authors: Sato Hiroshi
Published: September 2003

We construct one‐parameter complex analytic families whose special fibers are complete toric varieties. Under appropriate assumptions, the general fibers of these families also become toric varieties, and the corresponding fans are
explicitly described by the data of the fans associated to the special fibers. Using these families, we construct a deformation family for a certain toric weakened Fano 3‐fold. Moreover, we obtain certain examples of toric weakened Fano
4‐folds.
Darboux transformation for classical acoustic spectral problem
Authors: Yurova A. A. , Yurov A. V. , Rudnev M.
Published: September 2003

We study discrete isospectral symmetries for the classical
acoustic spectral problem in spatial dimensions one and two by
developing a Darboux (Moutard) transformation formalism for this
problem. The procedure follows steps similar to those for the
Schrödinger operator. However, there is no one‐to‐one
correspondence between the two problems. The technique developed
enables one to construct new families of integrable potentials for
the acoustic problem, in addition to those already known. The
acoustic problem produces a nonlinear Harry Dym PDE. Using the
technique, we reproduce a pair of simple soliton solutions of this
equation. These solutions are further used to construct a new
positon solution for this PDE. Furthermore, using the
dressing‐chain approach, we build a modified Harry Dym equation
together with its LA pair. As an application, we construct some
singular and nonsingular integrable potentials (dielectric
permitivity) for the Maxwell equations in a 2D inhomogeneous
medium.
Expression for a general element of an SO(n) matrix
Authors: Janaki T. M. , Rangarajan Govindan
Published: September 2003

We derive the expression for a general element of an SO(n) matrix. All elements are obtained from a single element of the matrix. This has applications in recently developed methods for computing Lyapunov exponents.
Growth Hormone Deficiency (GHD) from Birth to 2 Years of Age: Diagnostic Specifics of GHD during the Early Phase of Life
Authors: Ogilvy-Stuart Amanda L.
Published: September 2003

The first 2 years of life represent a transition period when growth changes from predominantly growth hormone (GH) independent to GH dependent. In the fetus, growth is influenced by genetic and environmental factors in addition to nutrition and growth factors including insulin. In infancy, nutrition remains an important determinant of growth. GH levels are high in mid-gestation and at birth, then fall sharply for the first few weeks and more slowly over the next few months reaching pre-pubertal levels by around the age of 6 months. GH deficiency (GHD) may present at birth with hypoglycaemia, micropenis or prolonged conjugated hyperbilirubinaemia. Although length at birth is usually within the normal centile ranges, post-natal growth failure can begin early and be profound.
Treatment of Growth Hormone Deficiency in Very Young Children
Authors: Carel Jean-Claude , Huet Frédéric , Chaussain Jean-Louis
Published: September 2003

Growth hormone (GH) deficiency is a rare disease in very young children and a challenge to the physician in terms of clinical recognition, diagnosis and treatment. Here, we review the available information regarding substitution of GH and other pituitary hormones in this patient group. Our results confirm the severity of the clinical presentation and the rapid loss of height (measured in standard deviation scores) in hypopituitary patients that occurs early in life. GH therapy induces a rapid catch-up of growth and the frequency of injections appears to be a more important determinant than the size of the dose itself. Long-term results are available in only a small percentage of patients, yet they show a favourable auxological outcome, compared with target height or historical height data from patients with severe hypopituitarism. In conclusion, although tremendous progress has been made in providing for those children with early onset and severe hypopituitarism, there is still a long way to go before we can claim that we have completely normalized their condition. In particular, careful assessments of the psychological and neurodevelopmental outcomes will become necessary in order to evaluate the ‘final results’ of endocrine replacement therapies.
Early-Onset Idiopathic Growth Hormone Deficiency within KIGS
Authors: Ranke Michael B. , Lindberg Anders , on behalf of the KIGS International Board o
Published: September 2003

Growth hormone (GH) deficiency is normally diagnosed when the affected child is between 6 and 8 years of age and a lack of normal growth first becomes noticeable. Some patients, however, are diagnosed as being GH deficient at a relatively young age (<2 years). These patients differ from the later-diagnosed patients in terms of their background, their characteristics of GH deficiency (GHD) and their response to GH replacement therapy. The analysis described in this article examined the similarities and differences between children in these categories identified from KIGS (Pharmacia International Growth Database). The results showed that although early-diagnosed patients had more severe GHD, they were much more responsive to GH therapy. Thus, it is suggested that early diagnosis and initiation of treatment in GH-deficient patients is strongly needed to achieve the maximum effects from therapy.
Puberty and Body Composition
Authors: Siervogel Roger M. , Demerath Ellen W. , Schubert Christine , Remsberg Karen E. , Chumlea William Cameron , Sun Shumei , Czerwinski Stefan A. , Towne Bradford
Published: September 2003

Body composition during puberty is a marker of metabolic changes that occur during this period of growth and maturation, and, thus, holds key information regarding current and future health. During puberty, the main components of body composition (total body fat, lean body mass, bone mineral content) all increase, but considerable sexual dimorphism exists. Methods for measuring body composition (e.g. densitometry and dual-energy X-ray absorptiometry) and degree of maturity will be discussed in this review. Components of body composition show age-to-age correlations (i.e. ‘tracking’), especially from adolescence onwards. Furthermore, adipose tissue is endocrinologically active and is centrally involved in the interaction between adipocytokines, insulin and sex-steroid hormones, and thus influences cardiovascular and metabolic disease processes. In conclusion, pubertal body composition is important, not only for the assessment of contemporaneous nutritional status, but also for being linked directly to the possible onset of chronic disease later in life and is, therefore, useful for disease risk assessment and intervention early in life.
Dose Effects of Growth Hormone during Puberty
Authors: Saenger Paul
Published: September 2003

During puberty, the production rate of growth hormone (GH) doubles and is associated with an increase in growth velocity. A significant percentage of the final adult height is attained during puberty, then after puberty, the production rate of GH decreases with age. In children with GH deficiency, it is known that the dosage of GH, in addition to the duration of treatment, can greatly influence the final adult height. At present, the dosage of GH given to children of short stature is kept at a constant rate throughout puberty. Thus, a study was conducted to investigate the effects of a higher dose of GH given to GH-deficient children during puberty. In this article, the design and results of the investigation and the importance of the findings will be discussed.
The Effects of Manipulation of Puberty on Growth
Authors: Lee Peter A.
Published: September 2003

Short stature in adulthood can be considered as a disability because it can be associated with many difficulties including those of a psychological and social nature. Many factors can influence final adult height such as genetics, the magnitude of growth hormone (GH) secretion, height before puberty, and the onset and duration of puberty. A crucial factor affecting final adult height, however, is the total height achieved during puberty. The combination of GH and gonadotropin-releasing hormone analogues greatly enhances growth and their separate and combined use for the treatment of GH deficiency, central precocious puberty and other diagnoses in children and adolescents is discussed in this article.
The KIGS Experience with the Addition of Gonadotropin-Releasing Hormone Agonists to Growth Hormone (GH) Treatment of Children with Idiopathic GH Deficiency
Authors: Reiter Edward O. , Lindberg Anders , Ranke Michael B. , Price David A. , Albertsson-Wikland Kerstin , Cowell Christopher T. , Bakker Bert
Published: September 2003

Although recombinant techniques have enabled the production of limitless amounts of human growth hormone (GH), and clinical methods for diagnosis and treatment have been greatly enhanced, the mean final heights of children with idiopathic GH deficiency (IGHD) treated with GH remain in the range of –1.3 standard deviation scores (SDS) below normal height. One of the methods used to increase height outcomes is to delay the onset and progression of puberty to allow for a longer ‘pre-pubertal’ growth phase. We reviewed the KIGS (Pharmacia International Growth Database) data of patients with IGHD who had been treated with gonadotropin-releasing hormone agonists (GnRHa) in order to see if a greater gain in height could be achieved by altering the tempo of pubertal maturation. Near-final height data were analysed in 39 adolescents (out of a total of 249) who had received GH + GnRHa therapy and were compared with similar data from 1,893 patients with IGHD treated with GH alone. The total change in height SDS in boys who received GH alone was +1.6, in contrast to +1.1 in GH + GnRHa-treated boys; the total change in height SDS in girls who received GH alone was +1.4 in contrast to +1.1 in girls treated with GH + GnRHa. The near final height SDS in girls treated with GH + GnRHa was 1.0 below the mid-parental target height (MPH), whereas there was only a –0.5 SDS difference in girls treated with GH. Approximation to the MPH did not differ in boys between the two treatment groups. These data suggest that the attainment of a substantial height SDS by manipulating the tempo of puberty is limited, but that optimizing growth during the pre-pubertal phase is a more important factor.
The Transition from Adolescence to Adult Life: Physiology of the ‘Transition’ Phase and Its Evolutionary Basis
Authors: Rosenfeld Ron G. , Nicodemus Barbara C.
Published: September 2003

The human life span is comprised of several life phases, each characterized by its own physiology. These phases (pre-natal, neonatal, infancy, childhood, juvenile, puberty, adolescence, prime and senescence) are important for the development of many biological and psychological processes. The ‘transition’ from adolescence to adult life in the human is a lengthy process in comparison with other species, and its evolutionary development has been long and complex. In this article, the characteristic features of this transition will be discussed, as well as the theory that the transition from adolescence to adult life should be considered as a life phase in its own right.
Growth Hormone Deficiency: Strategies and Indications to Continue Growth Hormone Therapy in Transition from Adolescence to Adult Life
Authors: Leong Gary M. , Johannsson Gudmundur
Published: September 2003

The most common practice in children with growth hormone (GH) deficiency is to discontinue GH treatment in adolescence after attainment of final height. Childhood-onset GH deficiency (GHD) that continues into adulthood and is not treated may be associated with more severe consequences than GHD acquired as an adult. This raises the question of the importance of GH for continuing tissue maturation after longitudinal growth has stopped. Data from recent studies suggest that muscle and bone maturation is arrested when GH treatment is discontinued at final height in adolescents in whom severe GHD continues into adulthood. These patients also develop, even in the short term, well-known cardiovascular risk factors associated with GHD in adults. Retesting for GHD is crucial in adolescence because a considerable number of patients will not have severe GHD according to the criteria set for adults. Continuing replacement therapy in these patients is warranted, but cost-benefit comparisons of treatment are still under debate and a lack of acceptance, and hence reimbursement, for such treatment is still common. In this review, the management and organization of transition, with and without continuing GH replacement therapy, are also discussed.
Effects of Ageing on Insulin Secretion and Action
Authors: Møller Niels , Gormsen Lars , Fuglsang Jens , Gjedsted Jakob
Published: September 2003

One of the many conditions associated with ageing is type 2 diabetes mellitus, the prevalence of which increases from 20–30 years of age onwards. In many cases, type 2 diabetes mellitus is caused by the combination of insulin resistance and poor insulin secretion. Insulin resistance is also a risk factor associated with other disorders, in particular cardiovascular disease. Physiological changes associated with ageing, such as changes in body composition, decreased physical fitness, changes in hormones, and the secondary effects of high levels of free fatty acids and glucose, may also contribute to the impairment of insulin secretion and action. In this review, the effects of ageing on the secretion and action of insulin will be highlighted.
Growth Hormone (GH) Status and Body Composition in Normal Ageing and in Elderly Adults with GH Deficiency
Authors: Toogood Andrew A.
Published: September 2003

Similarities have been observed between the changes associated with ageing and the symptoms of growth hormone (GH) deficiency. Changes such as increased fat mass and decreased muscle mass occur both in GH-deficient patients and in otherwise healthy elderly individuals. Moreover, ageing is associated with decreasing GH and insulin-like growth factor I (IGF-I) levels. It has been suggested, therefore, that hypothalamic-pituitary disease leading to GH deficiency (GHD) in elderly patients would have less impact than in younger adults. Studies suggest that healthy elderly individuals have normal pituitary reserves of GH, but that spontaneous GH secretion falls by around 14% per decade of adult life, leading to a state of functional GH insufficiency. Despite this, elderly patients with GHD experience reductions in GH secretion and IGF-I levels, compared with controls, which are of similar magnitude to those seen in younger GH-deficient adults. The metabolic changes associated with GHD are also seen in elderly patients compared with healthy elderly controls. Fat mass, particularly in the abdominal region, is significantly increased, with a strong correlation between fat mass and body mass index. Markers of bone formation and resorption are significantly reduced in the GH-deficient patients. Elderly adults who have hypothalamic-pituitary disease have a degree of GHD that can be distinguished from the decline in GH and IGF-I levels that is seen with normal ageing. GHD in elderly patients leads to significant changes in body composition and bone. Thus, these patients are likely to benefit from GH replacement therapy.
The Effects of Growth Hormone and Sex Steroid on Lean Body Mass, Fat Mass, Muscle Strength, Cardiovascular Endurance and Adverse Events in Healthy Elderly Women and Men
Authors: Harman S. Mitchell , Blackman Marc R.
Published: September 2003

Decreases in growth hormone (GH) and insulin-like growth factor I occur with age, in addition to oestrogen deficiency in women and a reduction in the levels of testosterone in men. These age-related hormonal changes may contribute to reductions in lean body mass, muscle strength and cardiac endurance, which can be partially reversed in elderly people with GH treatment, and testosterone supplements and oestrogen/progestin hormone replacement therapy in men and women, respectively. These treatments are, however, thought to have potentially serious adverse effects. We conducted a study to evaluate the separate and interactive effects of GH and sex steroids on body composition, muscle strength and cardiac endurance as well as the rate of adverse events in healthy elderly people. The results of the study showed that although there were beneficial effects with GH and sex steroid treatment, a high percentage of adverse effects occurred after 26 weeks of treatment, demonstrating a need for more research on the safety of hormonal therapy in the elderly population.
Adjuvant Hormonal Treatment for Prostate Cancer: The Bicalutamide Early Prostate Cancer Program
Authors: Wirth Manfred P. , Froehner Michael
Published: September 2003

Adjuvant hormonal therapy has been demonstrated to be able to delay disease progression in nonmetastatic prostate cancer. To date, however, a favorable impact on survival has only been demonstrated in lymph-node-positive disease and in external-beam radiotherapy series with locally advanced and probably mainly micrometastatic tumors. The Bicalutamide Early Prostate Cancer Program is the largest study under way to define the role of adjuvant treatment in early prostate cancer and identify subgroups of patients likely to benefit from immediate hormonal therapy. At the time of the most recently published analysis, the risk of objective clinical progression was significantly reduced in the bicalutamide arm (hazards ratio 0.58, 95% confidence interval 0.51–0.66, p < 0.0001). However, further maturation of data is needed to see whether this difference will lead to a survival advantage.
Bisphosphonates in the Management of Metastatic Prostate Cancer
Authors: Heidenreich Axel
Published: September 2003

Prostate cancer (PCA) frequently metastasizes to the bones, and skeletal metastases represent the most common cause of morbidity in advanced PCA. Besides the development of skeletal events due to metastases, patients with PCA are at higher risk for benign osseous complications, such as osteoporosis and fractures. Bisphosphonates (BPs) have emerged as an integral part of the management of skeletal disease related to PCA. Currently available data support their routine use to prevent androgen-deprivation-induced osteoporosis and its secondary complications. Dosing at 3-month intervals is appropriate; further studies will have to demonstrate the efficacy of annual dosing. In men with already established bone metastases, BPs might be helpful in preventing skeletal-related events in patients who do not respond to alternative therapies and are at high risk for bone fractures or spinal cord compression. In patients with hormone-refractory prostate cancer, BPs might be administered for analgesic purposes. Prospective randomized trials will have to explore the clinical role of BPs in the prevention of bone metastases following local therapy with curative intent in men at high risk for PCA recurrences.
Response to Combination Therapy with Interferon Alfa-2a and Ribavirin in Chronic Hepatitis C According to a TNF-α Promoter Polymorphism
Authors: Schiemann U. , Glas J. , Török P. , Simperl C. , Martin K. , König A. , Schmidt F. , Schaefer M. , Folwaczny C.
Published: September 2003

Background: Tumor necrosis factor-α (TNF-α) is involved in the pathogenesis of chronic active hepatitis C. Polymorphisms in the promoter region of the TNF-α gene can alter the TNF-α expression and modify the host immune response. The present study aimed at the correlation of the G308A TNF-α polymorphism with the response to antiviral combination therapy in chronic hepatitis C. Patients and Methods: 62 patients with HCV and 119 healthy unrelated controls were genotyped for the G308A TNF-α promoter polymorphism. The patients received 3 × 3 million units of interferon alfa-2a and 1,000–1,200 mg ribavirin daily according to their body weight. A response was defined as absence of HCV-RNA and normalization of S-ALT after 6 months of combination therapy. Results: With respect to the allele and genotype frequency, a significant difference was not observed between controls and patients with chronic hepatitis C. Furthermore, such a difference was also not observed if responders and non-responders to antiviral therapy were compared. Conclusions: The promoter polymorphism of the TNF-α gene investigated herein is equally distributed in healthy individuals and patients with hepatitis C and does not seem to predict the response to therapy with interferon alfa-2a and ribavirin.
Rapid Regression of Psoriasis in a Coeliac Patient after Gluten-Free Diet
Authors: Addolorato Giovanni , Parente Antonio , de Lorenzi Giosue , D’angelo Di Paola Maria Eugenia , Abenavoli Ludovico , Leggio Lorenzo , Capristo Esmeralda , De Simone Clara , Rotoli Maurizio , Rapaccini Gian Ludovico , Gasbarrini Giovanni
Published: September 2003

Background: Several skin disorders are present in patients affected by coeliac disease (CD) – among them, psoriasis has been described. However, at present the relationship between CD and psoriasis remains controversial since there are few and contrasting data on this topic. Method: Here we describe a case of psoriasis in a CD patient not responding to specific therapies for psoriasis. Result: The regression of skin lesions after gluten-free diet (GFD) was evident in a short time. Conclusion: The present case supports the association between CD and psoriasis and the concept that psoriasis in CD patients can be improved by GFD. Future studies are needed to clarify the possible mechanisms involved in this association.
Requirements for Adeno-Associated Virus-Derived Non-Viral Vectors to Achieve Stable and Site-Specific Integration of Plasmid DNA in Liver Carcinoma Cells
Authors: Steigerwald Robin , Rabe Christian , Schmitz Volker , Schmidt-Wolf Ingo G. , Alt Michael , Caselmann Wolfgang H.
Published: September 2003

Background and Aims: Adeno-associated virus (AAV) is the only known virus capable of site-specific genomic integration in human cells. Thus, AAV-based vectors may be an attractive option to achieve prolonged transgene expression in human cells. We therefore studied the minimal elements of gene therapy vectors necessary for stable integration and tested the effectiveness of this approach in hepatoma cells. Methods: Plasmids were constructed that contained a GFPneo fusion transgene with or without the AAV-inverted terminal repeats (ITRs). In addition, Rep protein was either encoded in cis or supplied in trans by co-transfections. Stable clones were analyzed by Southern blotting for site-specific integration. Results: The ITRs alone conferred neither stable nor site-specific transgene integration. Expression of Rep protein in cis or trans resulted in an increased frequency of integration regardless of the presence of ITRs. It was shown that in the absence of the ITRs, other Rep-binding site (RBS) like sequences such as the ColE1 sequence present in plasmid backbones can function as RBS. Site-specific integration was achieved in up to 26% of clones derived from hepatoma cells. Conclusion: Both expression of Rep proteins and inclusion of a RBS are necessary for enhanced and stable integration of AAV-based non-viral vectors. A novel two-plasmid system capable of achieving stable and site-specific gene transfer in hepatoma cells is introduced.
Inhibition of Cytochrome P450 3A: Relevant Drug Interactions in Gastroenterology
Authors: Sagir A. , Schmitt M. , Dilger K. , Häussinger D.
Published: September 2003

Cytochrome P450 3A (CYP3A) is involved in biotransformation of more than half of all drugs currently available. Drug interactions by inhibition of CYP3A are of major interest in patients receiving combinations of drugs. Some interactions with CYP3A inhibitors also involve inhibition of the multidrug export pump, P-glycoprotein. An increasing number of adverse drug reactions might be avoided on the basis of knowledge about CYP3A substrates and inhibitors. This article summarizes some examples of such interactions relevant to gastroenterologists. Serious cases by coadministration of CYP3A inhibitors resulting in acute hepatitis, hypotension, rhabdomyolyis, torsade de pointes, sedation, or ergotism are presented: interactions with azole antifungals (ketoconazole, itraconazole, fluconazole), HIV protease inhibitors (ritonavir, indinavir, saquinavir, nelfinavir), macrolide antibiotics (clarithromycin, erythromycin), and grapefruit juice. In addition, 1 case is reported who presented the highest trough levels of the CYP3A substrate budesonide in serum ever measured. Practitioners have to be aware of the high potential of metabolic drug interactions when they prescribe a CYP3A inhibitor. It is wise to check carefully comedication in patients complaining of side effects with substrates of CYP3A.
Nitric Oxide and Cardiac Function
Authors: Massion P.B. , Feron O. , Dessy C. , Balligand J.-L.
Published: September 2003

Nitric oxide (NO) is produced from virtually all cell types composing the myocardium and regulates cardiac function through both vascular-dependent and -independent effects. The former include regulation of coronary vessel tone, thrombogenicity, and proliferative and inflammatory properties as well as cellular cross-talk supporting angiogenesis. The latter comprise the direct effects of NO on several aspects of cardiomyocyte contractility, from the fine regulation of excitation-contraction coupling to modulation of (presynaptic and postsynaptic) autonomic signaling and mitochondrial respiration. This multifaceted involvement of NO in cardiac physiology is supported by a tight molecular regulation of the three NO synthases, from cellular spatial confinement to posttranslational allosteric modulation by specific interacting proteins, acting in concert to restrict the influence of NO to a particular intracellular target in a stimulus-specific manner. Loss of this specificity, such as produced on excessive NO delivery from inflammatory cells (or cytokine-stimulated cardiomyocytes themselves), may result in profound cellular disturbances leading to heart failure. Future therapeutic manipulations of cardiac NO synthesis will necessarily draw on additional characterization of the cellular and molecular determinants for the net effect of this versatile radical on the cardiomyocyte biology.
Homes for China
Authors: Gutierrez Laurent , Portefaix Valerie
Published: September 2003

Massive residential tower blocks have infiltrated Hong Kong's terri tory like a forest, heedless of geography. A look at a map or from the mountain peaks reveals a violent contrast between the dense high-rise developments and the natural island/mountain setting. From this evident juxtaposition, there is no doubt that lack of land and a growing population has provided the perfect context with which to experiment with new forms of densities. In this sense, land use and verticality are not the only vectors that set up Hong Kong's urban condition. Optimization drives the entire system to expand activities and movements at every level of its infrastructure, voids, or building blocks. Compactness draws the flowing crowds of people through an intensive network of lifts, escalators, streets, and mass transportation that runs in all directions. Speculation and the hectic market prices have discouraged agriculture and industry, and forced a hyper-selective urban land use. Through the years, this sectional direction has produced the most fascinating and dynamic form of density that has now reached a new extreme in the latest 72 story private residential model in Tsim Sha Tsui East on the Kowloon peninsula.
Have Brain Dynamics Evolved? Should We Look for Unique Dynamics in the Sapient Species?
Authors: Bullock Theodore Holmes
Published: September 2003

Ongoing “spontaneous” electrical field potentials of assemblies of neurons in the brains of diverse animal groups differ widely in character and amplitude without obvious explanation. There may be correlates with other measures of brain complexity, such as histological differentiation, but so far there are no known differences between the EEGs of humans and other mammals or between mammals and reptiles, amphibians or fish, apart from amplitude. The proposition is defended that further search for descriptors or statistical, probably nonlinear features of the time series will reveal consistent differences, meaning that we have so far missed major features of the natural history of EEGs, just as we have thus far relatively neglected the identification of features of the physiology of the brain relevant to its evolution of complexity through major grades of phyla, classes, and orders.
Is There Something Out There? Inferring Space from Sensorimotor Dependencies
Authors: Philipona D. , O'Regan J.K. , Nadal J.-P.
Published: September 2003

This letter suggests that in biological organisms, the perceived structure of reality, in particular the notions of body, environment, space, object, and attribute, could be a consequence of an effort on the part of brains to account for the dependency between their inputs and their outputs in terms of a small number of parameters. To validate this idea, a procedure is demonstrated whereby the brain of a (simulated) organism with arbitrary input and output connectivity can deduce the dimensionality of the rigid group of the space underlying its input-output relationship, that is, the dimension of what the organism will call physical space.
A Developmental Approach Aids Motor Learning
Authors: Ivanchenko Volodymyr , Jacobs Robert A.
Published: September 2003

Bernstein (1967) suggested that people attempting to learn to perform a difficult motor task try to ameliorate the degrees-of-freedom problem through the use of a developmental progression. Early in training, people maintain a subset of their control parameters (e.g., joint positions) at constant settings and attempt to learn to perform the task by varying the values of the remaining parameters. With practice, people refine and improve this early-learned control strategy by also varying those parameters that were initially held constant. We evaluated Bernstein's proposed developmental progression using six neural network systems and found that a network whose training included developmental progressions of both its trajectory and its feedback gains outperformed all other systems. These progressions, however, yielded performance benefits only on motor tasks that were relatively difficult to learn. We conclude that development can indeed aid motor learning.
Cell Responsiveness in Macaque Superior Temporal Polysensory Area Measured by Temporal Discriminants
Authors: Turner J. A. , Anderson K. C. , Siegel R. M.
Published: September 2003

The firing-rate data from 341 cells from two macaques' superion temporal polysensory area (STPa) were subjected to three different analyses to determine the temporal firing-rate patterns in response to visual optic flow patterns. The data were collected while the monkey viewed four types of optic flow and responded to the change in the display. The mean firing rate (MFR) analysis considered the mean change in firing rate for 500 ms after stimulus onset; the discriminant (DIS) analysis and the principal components (PCA+DIS) analysis considered the change in time-binned firing rate over 1000 ms after stimulus presentation, using bin sizes of 30 to 500 ms. The DIS analysis used a step-down discriminant analysis to find temporal windows in which the cell's firing rate could discriminate among the stimuli; the PCA+DIS analysis extracted the principal components of the cell's firing rates without regard for the stimulus type and then applied a step-down discriminant analysis to the PCA scores to determine whether any of the principal components could discriminate among the stimuli. The two temporal analyses found cells sensitive to the optic flows that the MFR analysis missed. A small proportion of cells showed multiple selectivities under the temporal analyses. Thus, the temporal analyses give a more complete representation of the information encoded by the firing properties of STPa neurons. Finally, this approach incorporates temporal approaches with classical statistical techniques in order to select tuned neurons from a population in an unbiased manner.
Local Interactions in Neural Networks Explain Global Effects in Gestalt Processing and Masking
Authors: Herzog Michael H. , Ernst Udo A. , Etzold Axel , Eurich Christian W.
Published: September 2003

One of the fundamental and puzzling questions in vision research is how objects are segmented from their backgrounds and how object formation evolves in time. The recently discovered shine-through effect allows one to study object segmentation and object formation of a masked target depending on the spatiotemporal Gestalt of the masking stimulus (Herzog & Koch, 2001). In the shine-through effect, a vernier (two abutting lines) precedes a grating for a very short time. For small gratings, the vernier remains invisible while it regains visibility as a shine-through element for extended and homogeneous gratings. However, even subtle deviations from the homogeneity of the grating diminish or even abolish shine—through. At first glance, these results suggest that explanations of these effects have to rely on high-level Gestalt terminology such as homogeneity rather than on low-level properties such as luminance (Herzog, Fahle, & Koch, 2001). Here, we show that a simple neural network model of the Wilson-Cowan type qualitatively and quantitatively explains the basic effects in the shine-through paradigm, although the model does not contain any explicit, global Gestalt processing. Visibility of the target vernier corresponds to transient activation of neural populations resulting from the dynamics of local lateral interactions of excitatory and inhibitory layers of neural populations.
Computing with Populations of Monotonically Tuned Neurons
Authors: Guigon Emmanuel
Published: September 2003

The parametric variation in neuronal discharge according to the values of sensory or motor variables strongly influences the collective behavior of neuronal populations. A multitude of studies on the populations of broadly tuned neurons (e.g., cosine tuning) have led to such well-known computational principles as population coding, noise suppression, and line attractors. Much less is known about the properties of populations of monotonically tuned neurons. In this letter, we show that there exists an efficient weakly biased linear estimator for monotonic populations and that neural processing based on linear collective computation and least-square error learning in populations of intensity-coded neurons has specific generalization capacities.
Slow Feature Analysis: A Theoretical Analysis of Optimal Free Responses
Authors: Wiskott Laurenz
Published: September 2003

Temporal slowness is a learning principle that allows learning of invariant representations by extracting slowly varying features from quickly varying input signals. Slow feature analysis (SFA) is an efficient algorithm based on this principle and has been applied to the learning of translation, scale, and other invariances in a simple model of the visual system. Here, a theoretical analysis of the optimization problem solved by SFA is presented, which provides a deeper understanding of the simulation results obtained in previous studies.
Bayesian Trigonometric Support Vector Classifier
Authors: Chu Wei , Keerthi S. Sathiya , Ong Chong Jin
Published: September 2003

This letter describes Bayesian techniques for support vector classification. In particular, we propose a novel differentiable loss function, called the trigonometric loss function, which has the desirable characteristic of natural normalization in the likelihood function, and then follow standard gaussian processes techniques to set up a Bayesian framework. In this framework, Bayesian inference is used to implement model adaptation, while keeping the merits of support vector classifier, such as sparseness and convex programming. This differs from standard gaussian processes for classification. Moreover, we put forward class probability in making predictions. Experimental results on benchmark data sets indicate the usefulness of this approach.
France and the German Question, 1945–1955
Authors: Creswell Michael , Trachtenberg Marc
Published: September 2003

This article challenges the traditional view that France was “obsessed” with the German threat in the decade after World War II and that French leaders only grudgingly accepted the policy that the United States and Britain had decided to pursue. The official rhetoric of the postwar period should not to be taken at face value. In reality, French leaders understood the logic of the “western strategy” for Germany and at a basic level endorsed it. Even on the question of West German rearmament—a critical issue in 1950—the French government was not nearly as opposed to moving ahead as many scholars have argued.
Response to Michael Creswell and Marc Trachtenberg
Authors: Cogan Charles
Published: September 2003

Three scholars offer separate responses to the article by Michael Creswell and Marc Trachtenberg. The responses include some common points, but they diverge sharply in other respects. The first two respondents generally agree with the conclusions reached by Creswell and Trachtenberg, but one of them believes that the article goes too far (in its contention that France's anxiety about the Soviet Union eclipsed its concerns about Germany), whereas the other argues that the article does not go far enough in showing how the United States adapted its policy to accommodate French leaders. The second respondent also questions whether Creswell and Trachtenberg have added anything new to the latest “revisionist” works on French-German relations in the first decade of Cold War. The third respondent, unlike the first two, rejects the main thrust of the article by Creswell and Trachtenberg and seeks to defend the traditional view that France was very reluctant to go along with U.S. and British policies on the German question. This respondent also questions whether Creswell and Trachtenberg have focused on the most appropriate sources of evidence.
New Light on an Old Issue?
Authors: Creswell Michael , Trachtenberg Marc
Published: September 2003

Michael Creswell and Marc Trachtenberg reply to the three commentaries, emphasizing the conflicting points raised therein. Addressing each of the respondents in turn, Creswell and Trachtenberg contend that their article accurately depicts French concerns in the late 1940s and 1950s, that it goes beyond existing “revisionist” works on the topic, that it debunks the traditionalist view of French policy, and that it makes use of the best evidence to judge French leaders' real (rather than publicly proclaimed) concerns.