bluuebunny/crossref_metadata_2025_split huggingface dataset:
Melanotrope dopamine D2 receptor isoform expression in the developing rat pituitary
Authors: Chronwall Bibie M. , Sands Scott A. , Dickerson Daniel S. , Sibley David R. , Gary Keith A. 
Published: July 2002

AbstractThis study measured melanotrope mRNA and protein expression for the dopamine D2 receptor, and its long isoform, in relation to the appearance of dopamine in axons of the postnatal rat pituitary intermediate lobe. At postnatal day 2, prior to the onset of dopaminergic innervation, D2 receptor (D2T) mRNA was expressed heterogeneously in a subpopulation of melanotropes which also expressed the long isoform (DL). The D2L mRNA appeared to be predominant during early postnatal development, since the D2T probe, which did not discriminate between the isoforms, and the D2L probe hybridized generally to the same cells, as demonstrated in serial sections. Immunohistochemical methods, using two different antisera for the D2T receptor, however, indicated a low level of protein in most melanotropes. Localization of D2L protein corresponded well to D2L receptor mRNA distribution. At day 10, representing a time when dopamine is present in axons throughout the lobe, both D2T receptor mRNA and protein were detected in a significantly larger population of melanotropes than those expressing D2L mRNA and protein. This suggests the appearance of detectable short isoform (D2S) mRNA in virtually all melanotropes and implicates dopamine as a possible signal for increasing D2S isoform mRNA expression.
Regional differences in in vitro growth of neural cell processes during development
Authors: Colombo J.A. , Napp M. , Medana A. 
Published: July 2002

AbstractPrimary cell cultures from cerebral cortex, striatum and ventral mesencephalon obtained from rat fetal (embryonic day 17, E17) or postnatal (day 2, PN2) donors were grown either in media conditioned by subcultured astroglia from the same regions, an artificial trophic medium, normal human amniotic fluid, or in normal human cerebrospinal fluid. To estimate the presence of neuronal‐like and non‐neuronal cells, cell morphology and immunocytochemistry against microtubule‐associated proteins and β‐tubulin were taken into consideration. The percentage of emitting neural cells and length of cell processes were determined after 24 hr in culture. Growth of cell processes in neuronal and non‐neuronal cells from prenatal striatum was minimal compared with that in cerebral cortex and ventral mesencephalon, regardless of the culture condition. Nerve growth factor, basic fibroblast growth factor or epidermal growth factor did not significantly modify cell growth in E17 cultures, except for epidermal growth factor, which reduced the number of emitting cells in striatal cultures and increased it in cerebral cortex ones. Cultures derived from postnatal striatum showed a significant increase in neurite length when grown in an astroglial conditioned medium as compared to cultures derived from prenatal (E17) striatum. Results suggest significant regional differences in the brain regarding growth of cell processes at age E17, and reversal of striatal ability to grow cell processes by postnatal day 2. Reduced growth of cell processes showed by E17 striatum cultures was rather independent of the culture media. This fact could suggest that such early regional differences would depend on characteristics of sublineages present at this developmental stage, which would modulate the organization of regional neuropils. The restricted growth of cell processes in cultures from E17 striatum, no longer present in postnatal striatum, suggests that inputs to the striatum may modify expression of cell lineages at later stages of development.
Concurrent engineering and its consequences
Authors: Koufteros Xenophon , Vonderembse Mark , Doll William 
Published: July 2002

AbstractTechnology and market changes introduce uncertainty and equivocality in the product development arena, and firms are considering various structural relationships to help them cope with these changes. Concurrent engineering (CE) is a mechanism that can reduce uncertainty and equivocality and improve an organization’s competitive capabilities. CE is typically manifested through concurrent work‐flows, product development teams, and early involvement of constituents. It enables information to flow through the organization quickly and effectively thereby, reducing uncertainty. At the same time, it enables debate, clarification, and enactment which are essential elements in combating equivocality. CE practices are also purported to have significant effects on product innovation, quality, and premium price capabilities.This research carefully defines CE and creates a valid and reliable instrument to assess it. It reports on the development and testing of a model that relates CE to some of its most salient consequences. Half of the sample of 244 firms is used for exploratory purposes and half for confirmatory work and hypotheses testing. Results indicate that firms that experience a high technological and product change in their environment are using more CE practices. In addition, results suggest that CE practices have significant direct effects on product innovation. However, only the indirect effects of CE on quality and premium pricing are statistically significant. Firms with higher levels of product innovation have higher levels of quality. Firms with higher levels of product innovation do exhibit premium pricing capabilities but only if they affect quality capabilities. Firms that display elevated quality levels excel in their premium pricing capabilities.
The rediscovery of postponement a literature review and directions for research
Authors: van Hoek R.I 
Published: July 2002

AbstractThe concept of postponement is increasingly drawing the attention of researchers and practitioners. Postponement means delaying activities in the supply chain until customer orders are received with the intention of customizing products, as opposed to performing those activities in anticipation of future orders. This paper reviews the literature on postponement dating back to 1965, and puts it in a systematic framework. In light of the classification of the literature developed, opportunities are identified for integration and cross‐fertilization between research papers in disciplines such as logistics and operations management and between the variety of research methods used. Some directions for research (in terms of content and methodology) are then formulated. For instance, the development of a more integrated supply chain perspective on postponement, and the application of triangulation rather than single methods. Specific research activities to meet these challenges are suggested in the paper.
E‐services: operating strategy—a case study and a method for analyzing operational benefits
Authors: Boyer Kenneth K. , Hallowell Roger , Roth Aleda V. 
Published: July 2002

AbstractThe Internet’s influence in creating e‐services has been revolutionary for providers and their customers. Unfortunately, there has been a wide gap between inspiring applications of the Internet that help increase service customization while maintaining or even improving delivery efficiency, and downright flops in which companies that have made bold promises have failed to deliver on even a portion of their pledges. This paper provides an examination of e‐services utilizing three approaches in order to provide guidance on how to fly rather than flop. First, we develop a model of the e‐service customer retention. Second, we offer a case study of Sothebys.com to illustrate how a well‐known, but not typically technologically adventurous, company can utilize e‐services to expand its offerings and streamline its services. Finally, we offer a profiling technique for analyzing the benefits and challenges of e‐services for particular industries.
Evaluating and classifying POM journals
Authors: Goh Chon‐Huat , Holsapple Clyde W. , Johnson Linda Ellis , Tanner John R. 
Published: July 2002

AbstractA multitude of journals impact the production and operations management (POM) discipline. POM researchers, practitioners, and students all need objective means of rating these journals' impacts on the field. By applying an established multifaceted citation‐based methodology, journals are assigned to categories (elite and major) along each of four dimensions (breadth, consistency, trend, and intensity of recognition) and subsequently organized into distinct tiers of importance to the production and operations management field. The data underlying this study consist of 13,992 periodical citations that appeared in three prominent POM journals over a recent five‐year period.
The impact of quality on learning
Authors: Li George , Rajagopalan S 
Published: July 2002

AbstractThe strategic importance of learning curves has been recognized for a long time both in industry and in academia, but little is known about the huge difference in rates at which different firms learn. Recent theoretical studies and anecdotal evidence from Japanese manufacturing firms suggest that quality‐related activities may be one major factor explaining the difference in learning rates. When the impact of quality on learning is considered, three important questions arise: (1) How well does cumulative output of defective or good units explain learning curve effects? (2) Do defective units explain learning curve effects better than good units? (3) How should cumulative experience be represented in the learning curve model when the quality level may have an impact on learning effects? This paper presents, to our knowledge, the first empirical study addressing these questions. Using time series data from two manufacturing firms, we find that cumulative output of defective or good units is statistically significant in explaining learning curve benefits. However, defective and good units do not explain learning curve effects equally as is implicitly assumed in traditional learning curve models. In particular, defective units are statistically more significant than good units in explaining learning curve effects.
Assessing production and operations management related journals: the European perspective
Authors: Soteriou Andreas C. , Hadjinicola George C. , Patsia Kalia 
Published: July 2002

AbstractFollowing the evolution and growth of the field of production and operations management (POM), a number of studies have recently appeared which provide insights on the ranking of the research outlets of the field. These studies are US‐based and exclude non‐US researchers. In this study we present rankings of the publication outlets in the POM discipline as perceived by POM researchers in Europe. Perceived relevance and quality of POM related journals, and differences between the rankings obtained by our study and those obtained by existing studies are identified. An examination of the publication rate of European researchers in five highly ranked journals provides further insights and future research directions.
Ethical issues in international buyer–supplier relationships: a dyadic examination
Authors: Carter Craig R 
Published: July 2002

AbstractThe author combines extant literature with findings from focus group interviews and a set of surveys to identify the ethical issues involved in relationships of US purchasing managers and their non‐US suppliers. Survey data from matched sets (dyads) of buyers and suppliers is then used to examine the influence of unethical behavior on the satisfaction with the relationship and on supplier performance.
The theory of performance frontiers
Authors: Vastag Gyula 
Published: July 2002

AbstractThis paper seeks to illustrate how the basic theory of performance frontiers proposed by Schmenner and Swink [Schmenner, R.L., and Swink, M.L., 1998. On theory in operations management. Journal of Operations Management, 17, 97–113] can be extended to apply to a broader range of operations management issues. It extends the scope of the proposed theory to include a “between‐firm” level analysis which can be useful in assessing a firm's competitive position and for strategic decision making. In addition, this paper provides a link between the resource‐based view of organizations that has gained some prominence in the strategy literature and the proposed theory of performance frontiers. This paper argues that the operating frontiers of organizations represent unique resources and they are more important than the asset frontiers in achieving a competitive advantage because these unique resources are valuable, rare and specific to a given firm, and they are difficult to replicate. Future research directions and research methods focusing on the internal resources of competitive advantage are also discussed.
On the existence of a positive solution of semilinear elliptic equations in unbounded domains
Authors: Bahri Abbas , Lions Pierre-Louis 
Published: July 2002

We prove here the existence of a positive solution, under general conditions, for semilinear elliptic equations in unbounded domains with a variational structure. The solutions we build cannot be obtained in general by minimization problems. And even if Palais-Smale condition is violated, precise estimates on the losses of compactness are obtained by the concentration-compactness method which enables us to apply the theory of critical points at infinity.

Résumé
Nous prouvons dans cet article l’existence d’une solution positive, sous des conditions générales, pour des équations semilinéaires elliptiques dans les domaines non bornés avec une structure variationnelle. Les solutions obtenues ne peuvent être en général obtenues par des problèmes de minimisation. Bien que la condition de Palais-Smale n’ait pas lieu, des estimées précises sur les pertes de compacité sont déduites de la méthode de concentration-compacité et nous permettent d’appliquer la théorie des points critiques à l’infini.
Carbon filaments direct the growth of postlesional plastic axons after spinal cord injury
Authors: Chauhan Neelima B. , Figlewicz Helen M. , Khan Talat 
Published: July 2002

AbstractThe effect of implantation of carbon filaments and fetal tissues on the axonal regeneration following contusion injury in a rat model was investigated by in situ immunofluorescence. Female Sprague‐Dawley rats were subjected to severe contusion injury to the spinal cord at T9–T10. All animals were divided into 5 groups (N=5/group): normal controls, surgical controls, with carbon filament implants, with fetal tissue implants and with implants consisting of fetal tissue cocultured with carbon filaments. After a 10‐week survival period, the astroglial response was assessed by immunoreactive glial fibrillary acidic protein and the neuro‐axonal profile by immunoreactive phosphorylated and nonphosphorylated neurofilament proteins. The contusion injury resulted in: (a) dramatically increased immunoreactivity of glial fibrillary acidic protein indicating injury‐associated reactive astrogliosis, (b) increase in immunoreactive phosphorylated neurofilament protein indicating upregulated phosphorylation of neurofilament protein, (c) with no change in the highly differentiated nonphosphorylated neurofilament protein which normally occur in the nonregenerating mature neurons. Implantation of fetal tissues alone following contusion injury did not show any appreciable change with regard to the immunoreactivities for the glial and neuronal markers studied, compared to the injury controls. However, the implantation of carbon filaments alone or together with fetal tissues directed the growth of glial fibrillary acidic protein‐positive astroglia and phosphoneurofilament‐positive neurites along the carbon fibers, with no effect on nonphosphoneurofilament protein. In conclusion, implantation of carbon filaments appears to be critical for facilitating the attachment of astroglia forming a substrate and scaffolding that can further support and direct the growth of postlesional plastic axons across the lesion. In addition, carbon filament prostheses in combination with fetal tissue implants provides an improved combinational approach to promote regrowth of injured neurons following injury.
Thromboembolism in heart failure: who should be treated?
Authors: Diet Frank , Erdmann Erland 
Published: July 2002

AbstractThe risk of thromboembolic complications in patients with heart failure and/or chronic left‐ventricular systolic dysfunction is increased. Nevertheless, anticoagulant therapy in these patients is still a subject of debate. Atrial fibrillation is the only prospectively evaluated, proven thromboembolic risk factor and patients with atrial fibrillation benefit from long term anticoagulant therapy. The significance of other proposed thromboembolic risk factors in heart failure and/or chronic left‐ventricular dysfunction such as gender, cause of myocardial disease, severity of heart failure, left‐ventricular ejection fraction, left‐ventricular thrombus, left ventricular aneurysm and history of previous thromboembolic event is less clear. This article summarizes key studies, assesses the incidence of thromboembolism, evaluates risk factors and proposes guidelines for anticoagulation of patients with heart failure and/or left ventricular systolic dysfunction.
Aquificales
Authors: Bonch‐Osmolovskaya Elizaveta 
Published: October 2020

AbstractBased on 16S ribosomal ribonucleic acid (rRNA) genes sequence comparisons, the order Aquificales represents a phylum Aquificeae, a very deep phylogenetic branch within the bacterial domain. It consists of two families, Aquificaceae and Hydrogenothermaceae. Some Aquificales relatives have an upper temperature limit of growth at 95 °C. Together with members of the order Thermotogales, they represent bacteria with the highest growth temperatures known so far. However, unlike Thermotogales, most of the members of the order Aquificales are lithoautotrophs, using energy of molecular hydrogen, or of reduced sulfur compounds to support their growth. Some Aquificales are able to use other than oxygen electron acceptors and grow anaerobically reducing nitrate, ferric iron or arsenate. Representatives of Aquificales inhabit terrestrial, submarine and deep subsurface thermal environments where they play role of primary organic matter producers. More than 40 genomes of Aquificales have already been sequenced providing access to new genes encoding thermostable enzymes for bioindustry.Key ConceptsAquificales represent one of the most ancient lineages of Bacteria.Aquificales are among the organisms having the highest growth temperatures among Bacteria.Aquificales are lithoautotrophs utilising inorganic energy substrates of volcanic origin.Aquificales are widely spread all over the Earth thriving in submarine and terrestrial thermal environments, as well as in subsurface biosphere.In terrestrial hot springs, some Aquificales form visible biofilms and hair‐like ‘streamers’ utilising hydrogen sulfide and hydrogen dissolved in streaming water.
From Neural Induction in Frogs to Human Brains on Chips
Authors: De Santis R , Brivanlou Ali H 
Published: October 2020

Abstract

The entire nervous system of the vertebrate embryo is derived from an epithelium sheet called the neural plate, which is induced by the organizer/node at the onset of gastrulation. Dissection of the molecular network underlying the emergence of the neural plate, originally performed in
Xenopus
embryos, led to the discovery of the TGFβ double inhibition mechanism for neural induction, coined ‘the default model’. Years later, these developmental principles have been translated
in vitro
to instruct human pluripotent stem cells towards neural fate and to build brain organoids.

Key Concepts

The Spemann organizer is defined by the capability of a group of cells in a transplantation experiment to induce, in a non‐cell‐autonomous fashion, a secondary neural axis and to autonomously differentiate into axial and paraxial mesoderm derivatives.

Neural fate acquisition both
in vivo
in the embryo and
in vitro
from pluripotent stem cells is the result of blocking the ongoing TGFβ pathway, both Activin‐Nodal and BMP branches.

Embryonic stem cells are defined based on two basic properties: their ability to maintain their undifferentiated state (stemness) indefinitely and to be able to differentiate into cell types derived from the three embryonic germ layers (pluripotency).

Brain organoids are 3D
in vitro
structures that resemble several features of the developing human brain.

Human pluripotent stem cells cultured in confined geometry (micropattern) self‐organized into defined embryonic structures with standardised cytoarchitecture and distinct cell fates.
DrosophilaEmbryo: Homeotic Genes in Specification of the Anterior–Posterior Axis
Authors: Rogers Bryan T 
Published: October 2020

AbstractEmbryonic expression of homeotic genes inDrosophila melanogasterimparts the diversity of morphology and cell type along the anterior–posterior axis that is characteristic of its body plan. The homeotic genes encode a related set of nine transcription factors. Each homeotic gene has a unique, temporally dynamic expression pattern, battery of target genes and range of regulatory effects. Changes in any of these three aspects can have dramatic consequences due to the large number of target genes affected. These dramatic effects place the homeotic genes high in the regulatory gene hierarchy of developmental programmes and are sometimes referred to as ‘master regulators’ of identity. The combined action of all nine genes produces a unique cellular pattern of gene activation and repression across the embryo that changes throughout development. The result is the specification of the diverse cells and tissues typical of the animal body in the precise pattern that gives each segment or region its own identity.Key ConceptsMutations in Hox genes alter their modulation of underlying developmental programmes and produce homeotic transformations.The Hox genes ofDrosophila melanogasterare organised into two complexes that arose from a single ancestral complex.The variation among Hox genes limits the diversity of segment‐specific development.HOX proteins are transcription factors that bind DNA via the homeodomain which is encoded by the homeobox.Homeoboxes and homeodomain proteins form a superfamily of which the Hox genes are a small part.Hox expression and segmentation are initiated by the same regulatory cascade, insuring proper domains of Hox expression.An important aspect of Hox expression is that it is not static but continually changing during development.Initiation of Hox expression requires different factors than their maintenance, which depends on the chromatin structure.By regulating the expression of other regulators such as selector and signal transducing genes, Hox genes greatly magnify the number of genes under their control.Segmental identity is a consequence of a unique combination of Hox‐regulated events achieved by the dynamic and diverse temporal and spatial expression of Hox genes and the specific target recognition and regulation capabilities of each Hox protein.