bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sox2 expression defines a heterogeneous population of neurosphere‐forming cells in the adult murine brain
Authors: Brazel Christine Y. , Limke Tobi L. , Osborne Jihan K. , Miura Takumi , Cai Jingli , Pevny Larysa , Rao Mahendra S. 
Published: July 2005

SummaryThe identification of neural stem cells (NSCs) in situ has been prevented by the inability to identify a marker consistently expressed in all adult NSCs and is thus generally accomplished using the in vitro neurosphere‐forming assay. The high‐mobility group transcription factor Sox2 is expressed in embryonic neural epithelial stem cells; because these cells are thought to give rise to the adult NSC population, we hypothesized that Sox2 may continue to be expressed in adult NSCs. Using Sox2:EGFP transgenic mice, we show that Sox2 is expressed in neurogenic regions along the rostral–caudal axis of the central nervous system throughout life. Furthermore, all neurospheres derived from these neurogenic regions express Sox2, suggesting that Sox2 is indeed expressed in adult NSCs. We demonstrate that NSCs are heterogeneous within the adult brain, with differing capacities for cell production. In vitro, all neurospheres express Sox2, but the expression of markers common to early progenitor cells within individual neurospheres varies; this heterogeneity of NSCs is mirrored in vivo. For example, both glial fibrillary acidic protein and NG2 are expressed within individual neurospheres, but their expression is mutually exclusive; likewise, these two markers show distinct staining patterns within the Sox2+ regions of the brain's neurogenic regions. Thus, we propose that the expression of Sox2 is a unifying characteristic of NSCs in the adult brain, but that not all NSCs maintain the ability to form all neural cell types in vivo.
Long term Changes in the Relative Abundances of Birds in Kings Park, Perth, Western Australia
Authors: RECHER H. F. , SERVENTY D. L. 
Published: July 2005

Abstract. D. L. Serventy censused birds in Kings Park, Perth, between 1928 and 1937 and again between 1952 and 1955. Abundance was estimated by the frequency with which species were detected on censuses. The counts were repeated in 1986 by H. F. Recher. A total of 44 species were recorded during censuses. Since the first counts, were made, 14 species decreased in abundance by more than 15%, and 9 species went locally extinct. Eleven species increased in abundance by more than 20% (5 by more than 50%), and the abundance of 19 remained unchanged (frequency of occurrence changed by less than 15%).Although nearly 300 ha of the park's 400 ha area remains as native vegetation, this vegetation has been degraded by logging, changed fire regimes, construction of trails, and invasion by exotic weeds. Changes in the ground vegetation have had a particularly significant impact. Nine of the 16 species that declined in abundance are ground foragers. Of the species that increased in abundance, a number benefit from the greater availability of nectar, fruits, and water in the suburban gardens that have developed around the park The Australian Raven (Corvus coronoides) has become particularly abundant and predation by ravens on nests was contribute to the decline of some species Changes to tbe park vegetation, suburban development of the park's immediate surroundings, and the extensive clearing of vegetation throughout southwestem Australia appear to have had a more signifcant effect on the park's avifauna than the sire of the park or its isolation in an urban environment. Poor management has seriously reduced the capacity of Kings Park to support native wildliye. Changes in park management designed to mbabilitate native vegetation, control weeds, and control ravens are necessary to prevent the further loss of species from the park's avifauna.
Measurement of Genetic Variation in Endangered Populations: Bandicoots (Marsupialia: Peramelidae) as an Example
Authors: SHERWIN WILLIAM B. , MURRAY NEIL D. , GRAVES JENNIFER A. MARSHALL , BROWN PETER R. 
Published: July 2005

Abstract. Attempts to monitor the genetic variation of endangered populations by the use of blood protein electrophoresis often suffer from three drawbacks: a small sample of loci, lack of control populations with “normal” variation, and, sometimes, difficulty in confirming inheritance of electromorphs.An endangered isolate (Hamilton, Victoria) of the eastern barred bandicoot, Perameles gunnii, was compared with a widespread, dense, conspecific population in Tasmania. A previous study of the effective size of the siolate suggested that the loss of variation should be detectable by protein electrophoresis if average heterozygosity (h̄) was approximately 0.057 in widespread, dense populations and 20 to 50 individuals from each population were analysed for 25 or more loci. However, no genetic variation was detected within or between samples.Similar studies proposed as a baseline for monitioring genetic variation could be equally powerless to detect changes in variation, even with quite high h̄ values. The analysis of variation in DNA is expected to avoid many of the problems associated with blood protein studies.This study highlights the importance of a control population. Analysis of the Hamilton population alone might have led us to concludce that the recent population crash has been responsible for the low variation; however, this conclusion is not warranted, because h̄= 0 in the much larger Tasmania population.
Bioengineered tissues: the science, the technology, and the industry
Authors: Ahsan T , Nerem RM 
Published: July 2005

Structured AbstractAuthors –  Ahsan T, Nerem RMObjective –  The bioengineering of tissues and organs, sometimes called tissue engineering and at other times regenerative medicine, is emerging as a science, as a technology, and as an industry. The goal is the repair, replacement, and/or the regeneration of tissues and organs. The objective of this paper is to identify and discuss the major issues that have become apparent.Results –  One of the critical issues is that of cell source, i.e. what will be the source of the cells to be employed? Another critical issue is the development of approaches for the fabrication of substitute tissues/organs and/or vehicles for the delivery of biological active molecules for use in the repair/regeneration of tissues. A third critical issue, one very much related to cell source, is that of immune acceptance. In addition, there are technological hurdles; there are additional issues such as the scale‐up of manufacturing processes and the preservation of living‐cell products for off‐the‐shelf availability. Although the initial products have been superficially applied skin substitutes, as this fledgling industry continues to evolve, it is beginning to focus on a wider range of more invasive and complicated products. From a public health perspective, the real opportunity may be in addressing chronic diseases, as well as the transplantation crisis (i.e. the tremendous disparity between patient need for vital organs and donor availability) and, equally important is the challenge of neural repair.Conclusion –  These are the grand challenges, and the scientific community, business/private sector, and federal government must mobilize itself together in this emerging area to translate the benchtop science to the patient bedside.
The efficacy of mesenchymal stem cells to regenerate and repair dental structures
Authors: Shi S , Bartold PM , Miura M , Seo BM , Robey PG , Gronthos S 
Published: July 2005

Structured AbstractAuthors –  Shi S, Bartold PM, Miura M, Seo BM, Robey PG, Gronthos SObjectives –  Identification, characterization, and potential application of mesenchymal stem cells (MSC) derived from human dental tissues.Methods –  Dental pulp and periodontal ligament were obtained from normal human impacted third molars. The tissues were digested in collagenase/dispase to generate single cell suspensions. Cells were cultured in α‐MEM supplemented with 20% fetal bovine serum, 2 mM l‐glutamine, 100 μM l‐ascorbate‐2‐phosphate. Magnetic and fluorescence activated cell sorting were employed to characterize the phenotype of freshly isolated and ex vivo expanded cell populations. The developmental potential of cultured cells was assessed following co‐transplantation with hydroxyapetite/tricalcium phosphate (HA/TCP) particles into immunocompromised mice for 8 weeks.Results –  MSC were identified in adult human dental pulp (dental pulp stem cells, DPSC), human primary teeth (stem cells from human exfoliated deciduous teeth, SHED), and periodontal ligament (periodontal ligament stem cells, PDLSC) by their capacity to generate clongenic cell clusters in culture. Ex vivo expanded DPSC, SHED, and PDLSC populations expressed a heterogeneous assortment of makers associated with MSC, dentin, bone, smooth muscle, neural tissue, and endothelium. PDLSC were also found to express the tendon specific marker, Scleraxis. Xenogeneic transplants containing HA/TCP with either DPSC or SHED generated donor‐derived dentin‐pulp‐like tissues with distinct odontoblast layers lining the mineralized dentin‐matrix. In parallel studies, PDLSC generated cementum‐like structures associated with PDL‐like connective tissue when transplanted with HA/TCP into immunocompromised mice.Conclusion –  Collectively, these data revealed the presence of distinct MSC populations associated with dental structures with the potential of stem cells to regenerate living human dental tissues in vivo.
Non‐viral‐mediated gene therapy approaches for bone repair
Authors: Winn SR , Chen JC , Gong X , Bartholomew SV , Shreenivas S , Ozaki W 
Published: July 2005

Structured AbstractAuthors –  Winn SR, Chen JC, Gong X, Bartholomew SV, Shreenivas S, Ozaki WObjectives –  Bone repair strategies continue to be developed for alternatives to autografting, allogeneic implants of banked bone, and other bone substitutes. Efforts have included the delivery of potent growth and/or differentiation factors and the use of gene therapy. For bone regeneration, gene therapy is the delivery, uptake and expression of DNA that has been localized to a wound bed. The objective of the current study is to investigate methods to enhance non‐viral‐mediated means of gene uptake and expression for use in bone regeneration.Methods –  Several types of DNA‐polymer complexes, either applied directly to baby hamster kidney (BHK) cells, or released from a porous, resorbable gene‐activated matrix (GAM), were evaluated in vitro for their ability to transfect cells with a circular plasmid DNA construct expressing green fluorescent protein. Complexes included conjugates containing a lipophilic reagent, liposomes, poly‐ethyl‐oxazoline, and poly‐ethyleneimine (PEI). Data were subjected to analysis of variance and Fisher's protected least significant difference for multiple comparisons with significance established at p < 0.05.Results –  Transfection efficiencies of the liposome and PEI complexes improved in vitro when released from resorbable GAMs. The lipophilic reagent FuGene 6 demonstrated abundant uptake and expression in the initial 1‐ and 2‐day evaluation periods. In contrast, the DNA‐liposome and PEI GAM complexes demonstrated a sustained release, uptake and expression by the BHK cells at the 2‐, 4‐, and 7‐day, and 4‐ and 7‐day evaluation intervals, respectively.Conclusion –  GAM technology appears to improve the functional stability and release duration of incorporated DNA‐polymer complexes in the present in vitro studies. The ongoing objective of our research is to develop a localized treatment to improve the uptake and expression of plasmid DNA by non‐viral‐mediated gene therapy.
Erfahrungen mit der neuen American Joint Committee on Cancer (AJCC)‐Klassifikation des kutanen malignen Melanoms
Authors: Eigentler Thomas K. , Radny Peter , Kamin Anne , Weide Benjamin , Caroli Ulrich M. , Garbe Claus 
Published: July 2005

ZusammenfassungIm Jahr 2001 wurde eine neue AJCC/UICC‐Klassifikation und Stadieneinteilung des malignen Melanoms publiziert, die seitdem für die Eingruppierung des malignen Melanoms gültig ist. Im Vergleich zu der vorherigen für einen Zeitraum von etwa 15 Jahren gültigen Klassifikation wurden erhebliche Änderungen eingeführt. Die Klassifikation des Primärtumors stützt sich jetzt auf neue Klassenbildungen für die Tumordicke nach Breslow (0 – 1,0 mm; 1,01 – 2,0 mm, 2,01 – 4,0 mm; > 4,0 mm). Zusätzlich wird eine histopathologisch diagnostizierte Ulzeration mit zur Einteilung herangezogen, die zur Eingruppierung in die nächsthöhere T‐Kategorie führt. Der Invasionslevel nach Clark hat nur noch für Tumoren mit einer Tumordicke bis 1 mm Bedeutung, hier führt Level IV und V zur Einordnung in die nächsthöhere T‐Kategorie. Die Einteilung der regionären Lymphknotenmetastasierung basiert auf der Unterscheidung zwischen nur mikroskopisch erkennbarer Metastasierung in der Wächterlymphknotenbiopsie oder makroskopisch‐klinisch erkennbarer Metastasierung, weiterhin gehen in die Einteilung die Zahl der befallenen Lymphknoten und das Auftreten von Satelliten‐ und In‐transit‐Metastasen mit ein. Bei Fernmetastasierung spielt die Art des Organbefalls (nur Haut und Lymphknoten vs. Lunge vs. andere Organe) sowie der LDH‐Wert eine Rolle, bei dessen Erhöhung eine Eingruppierung in die ungünstigste Kategorie erfolgt. Kritisch bleibt anzumerken, dass die starke Rolle, die der Ulzeration des Primärtumors zukommt, anhand der Daten des deutschen Zentralregisters malignes Melanom nicht bestätigt werden konnte. Weiter ist es ungünstig, dass das Stadium IIC eine signifikant ungünstigere Prognose aufweist als das Stadium IIIA, hier ist die Klassifikation inkonsistent. Die neue Stadieneinteilung sollte dennoch, insbesondere in klinischen Studien, um eine internationale Vergleichbarkeit der Daten zu ermöglichen, verwendet werden.
Factors Influencing Productivity Enhancing and Environmental Husbandry on Rented Land
Authors: van Vuuren W. , Larue B. , Ketchabaw E. H. 
Published: July 2005

Logistic regression analysis is used to determine what impact tenant, contract and land characteristics have on farm practices enhancing productivity and the environment. The results of the study indicate that contract terms play an important role in environmental husbandry on rented land.Des régressions avec variables dépendantes qualitatives sont utilisées pour analyser l'importance relative des caractéristiques des locataires, des contrats (de location), et des terres sur l'adoption de pratiques agricoles améliorant la productivité et la qualité de l'environnement. Les résultats indiquent que les clauses contractuelles jouent un rôle très important sur les aspects environnementaux liés à la gestion des terres louées.
Climatic Change and Canada's Boreal Forest: Socio‐economic Issues and Implications for Land Use
Authors: van Kooten G. Cornelis 
Published: July 2005

This paper reviews the effect of climatic change and policies to sequester carbon on forest land use. Efficient mitigation strategies often require the conversion of agricultural land to forestry in order to sequester carbon, but such strategies could be wrong for Canada's boreal forest region if global warming is inevitable. It is argued that, from both an economic and a social perspective, conversion of the southern boreal forest to grassland or agriculture might be a better policy.L'article passe en revue l'effet des changements climatiques et des politiques utilisées pour capter le gaz carbonique, sur l'utilisation des terres forestières. Pour être efficace, les stratégies d'atténuation nécessitent souvent la reconversion des terres agricoles à l'exploitation forestière afin de capturer le bioxyde de carbone mais, cette stratégie pourrait se révéler mauvaise pour la forêt boréale canadienne advenant l'inévitabilité d'un réchauffement planétaire. L'auteur estiment qu'autant dans la perspective économique que dans la perspective sociale, une meilleure solution serait plutôt de reconvertir le sud de la forêt boréale à la prairie ou à l'agriculture.
Comparaison de la rentabilité des systèmes conventionnels et biologiques en production laitière au Québec
Authors: Burgoyne Daniel , Levallois Raymond , Perrier Jean‐Philippe , Pellerin Doris , Paillat Et Nicolas 
Published: July 2005

De la banque de données AGRITEL, 336 fermes conventionnelles et 16 fermes biologiques, spécialisées en production laitière, sont sélectionnées. Sept groupes (dont un est biologique) sont alors formés correspondant à des concepts de production différents. Les groupes defermes conventionnelles correspondent à des niveaux d'intrants particulièment élevés (haut niveau d'intrants) ou faibles (bas niveau d'intrants), ainsi qu'à des niveaux de production élevés @roduction intensive) oufaibles (production extensive), pour le troupeau ou pour l'ensemble de l'entreprise.Les fermes biologiques parviennent à des résultats technico‐économiques et financiers au moins aussi bons que les fermes avec des rendements élevés (intensifs). En revanche, même si les concepts de production sont proches, les différences de rendement et de rentabilité sont assez nettes (souvent signcatives) entre le groupe biologique et les groupes extensifs ou à bas niveau d'intrants. Les entreprises biologiques sont plus équilibrtés et la prédominance de la production laitière est moindre. Les coûts de main‐d'œuvre sont toutefois plus élevés que la plupart des groupes d'entreprises conventionnelles.Cette étuaè nous laisse croire qu'il est possible d'amtéliorer la rentabilité des fermes extensives et à bas niveau d'intrants, dont les concepts de production se rapprochent de ceux de l'agriculture biologique.
Open Economy and Processor Oligopoly Power Effects of Beef Advertising in Canada
Authors: Cranfield John A. L. , Goddard Ellen W. 
Published: July 2005

A North American beef industry model incorporating a hypothesized relationship between beef advertising and processor oligopoly power was estimated and used to evaluate various advertising options faced by Canadian cattle producers. Generic and branded advertising significantly increased Canadian and U.S. beef demand. As well, historic generic beef advertising expenditure in Canada returned a net profit to Canadian producers. However, additional Canadian producer investment in generic beef advertising in Canada lowered producer profits, while investment in Canadian or U.S. brand advertis‐ ing or U.S. generic advertising generated positive net returns.Nous avons construit un modèle mathématique pour le secteur nord‐américain de la viande de boeuf, incorporant un rapport hypothétique entre la publicité du produit et le pouvoir oligopolistique au niveau du secteur de la préparation‐transformation. Nous avons utilisé le modéle pour évaluer diverses options de publicité auxquelles font face les producteurs de bavins canadiens. La publicité générique et la publicité de marque ont procuré un accroissement de la demande de viande bovine tant au Canada qu'aux États‐Unis. De plus, les dépenses engagées au cours des années au chapitre de la publicité générique de la viande bovine au Canada ont valu aux producteurs canadiens un bénéfice net. En revanche tout accroissement des investissements consacrés à la publicité générique par ces producteurs s‘est soldé par une baisse des profits à la production, alors qu‘aux États‐Unis il se révélait en général rentable. Par aileurs, l'intensification de la publicité de marque s'est montrée rentable dans les deux pays.
Optimal Generic Advertising Decisions in Supply‐managed Industries: Clarification and Some Further Results
Authors: Kinnucan Henry W. 
Published: July 2005

Supply control enhances the incentive to promote through its ancillary trade policies that protect the domestic industry from foreign competition. Incentives are intensified when supply control is coupled with a price discrimination scheme that renders the supply of the agricultural product to the higher‐priced (premium) market perfectly elastic. In this case, aper‐unit levy imposed on the premium market to finance the advertising is shifted entirely to consumers, which means that the producer cost of advertising the premium product is nil. This in essence is the situation for fluid milk in Canada, Taiwan and California, which explains in part why fluid milk dominates the generic advertising scene in these regions. This article investigates these and related issues in some detail, using an earlier analysis by Goddard and McCutcheon as the point of departure.La gestion de l'offre amplifie les incitations à produire par le biais de ses politiques corrollaires de commerce extérieur qui mettent le secteur intérieur à I'abri de la concurrence étrangère. Les incitations sont defait intensifiées lorsque le contrôle de I'offre est coupléà un systéme de discrimination des prix qui rend I'offre d'unproduit agricole donné sur le marché les plus lucratifs parfaitement élastique. Dans ce cos, le droit unitaire imposé au marché le plus rentable pourfinancer la publicité est refilé entiérement aux consommateurs, de sorte que le coût à la production de la promotion duproduit vedette est nul. C'est essentiellement la situation qui prévaut pour le lait de consommation au Canada, à Taïwan et en Californie, ce qui en partie explique la prédominance de ce produit dans la publicité générique dans ces régions. Nous examinons ces questions plus ou moins en détail utilisant comme point de départ une analyse antérieure faite par Goddard et McCutcheon.
A Note on Asymmetry in Commodity Futures Markets
Authors: Gravelines Rony S. , Boyd Milton 
Published: July 2005

This study tests for asymmetry in futures price changes using commodities from a variety of groups such as agricultural, metals, and financials. Tests are used to determine whether or not prices move up in the same fashion as they move down, over varying data frequencies. The results indicate that every commodity analyzed shows at least some degree of asymmetry.Nous avons scruté les signes éventuels d'asymétrie dans l'évolution des prix à terme de certaines catégories de produits agricoles, industriels (pétrole et métaux) et boursiers. Des tests ont été utilisés pour déterminer si les prix moment de la même façon qu'ils descendent pour diverses fréquences d'établissement des prix (quotidien, hebdomadaire, mensuel). Il ressort de ces analyses que chaque type de produit comportait au mains un certain degré d'asymétrie.
The Future of European Union Dairy Policy
Authors: Benjamin Catherine , Gohin Alexandre , Guyomard Hervé 
Published: July 2005

Even if the quota regime has been extended until 2007–08 as part of the Agenda 2000 reform adopted in March 1999, the European Union (EU) dairy sector is currently experiencing large uncertainty over future policy. This paper examines EU dairy policy issues and assesses their likely implications. It mainly addresses the central question of dismantling the quota and intervention support mechanisms. Simulation results illustrate how three factors (marginal costs of production, import tariffs on dairy products and compensatory payments granted to dairy producers) may affect the outcomes of a quota elimination scenario.Même si le régime des quotas a été prolongé jusqu'en 2007–2008 à l'occasion de la réforme Agenda 2000 de mars 1999, le débat sur la nécessité d'une réforme plus importante de la politique laitiére européenne n'est pas clos. Dans ce papier, nous analysons les différentes contraintes auxquelles l'Union européenne doit faire face et ses implications pour le secteur laitier communautaire. L'attention est centrée sur les conséquences d'une suppression du régime des quotas et du mécanisme de l'intervention. Les résultats de simulation montrent comment les conséquences d'un tel scénario dépendent de trois facteurs, i.e., les coûts marginaux de production du lait, la protection tarifaire sur les importations européennes de produits laitiers et les mesures de compensation accordées aux producteurs de lait.