bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differential signal transduction via TrmB, a sugar sensing transcriptional repressor of Pyrococcus furiosus
Authors: Lee Sung‐Jae , Surma Melanie , Seitz Sabine , Hausner Winfried , Thomm Michael , Boos Winfried 
Published: May 2007

SummaryTrmB is a transcriptional repressor of the hyperthermophilic archaeon Pyrococcus furiosus serving at least two operons. TrmB represses genes encoding an ABC transporter for trehalose and maltose (the TM system) with trehalose and maltose as inducers. TrmB also represses genes encoding another ABC transporter for maltodextrins (the MD system) with maltotriose and sucrose as inducers. Here we report that glucose which was also bound by TrmB acted as a corepressor (causing stronger repression) for both the TM and the MD system. Binding of glucose by TrmB was increased in the presence of TM promoter DNA. Maltose which acted as inducer for the TM system acted as a corepressor for the MD system intensifying repression. We propose that the differential conformational changes of TrmB in response to binding the different sugars governs the ability of TrmB to interact with the promoter region and represents a simple mechanism for selecting the usage of one carbon source over the other, reminiscent of catabolite repression in bacteria.
Early proliferation of umbilical cord blood cells from premature neonates
Authors: Luzo A. C. M. , Duarte A. S. S. , Salles T. S. I. , Queiroz M. L. S. , Lorand‐Metze I. , Costa F. F. , Saad S. T. O. 
Published: May 2007

Background and Objective  Human umbilical cord blood (UCB) is an important source of haematopoietic stem cells; however, the behaviour of progenitor cells obtained from premature and full‐term neonates is still a controversy subject. Thus, the aim of this study was to evaluate cell cycle parameters and the proliferative capacity of UCB progenitor cells from premature and full‐term neonates.Material and Methods  Clonogenic assays were performed with methylcellulose, medium supplemented with recombinant stimulating growth factors and the colonies were scored on the seventh day and the 14th day of culture. A cell cycle study was carried out by DNA analysis using flow cytometry and 30 000 events were acquired; p107 and p130 expressions were analysed by Western blotting.Results  Cultures obtained from UCB of premature neonates showed an early growth of colony‐forming unit (CFU)‐burst forming unit erythroid/CFU‐granulocyte, erythrocyte, macrophage and megakaryocyte (BFU‐E/GEMM), and CFU‐granulocyte, macrophage (GM) by the seventh day of culture (P < 0·001). Therefore, the number and morphological characteristics of these colonies were comparable with those obtained from full‐term neonates, on the 14th day of culture. At the 14th day, a large amount of CFU‐GM was detected in the premature group (P < 0·0032). The premature culture on the 14th day showed fibroblasts and was comparable to those of full‐term neonates on the 21st day in terms of number and morphology of the colonies. DNA analysis showed that the number of cells in S‐phase was also higher in premature samples when compared to full‐term neonates, P < 0·0021 (0 h = 12·8 vs. 2·5%; 16 h = 10·5 vs. 5·9%; 20 h = 13·5 vs. 10·3%; 24 h = 13·8 vs. 9·1%; 48 h = 14·0 vs. 5·4%; 72 h = 20·5 vs. 8·9%; 96 h = 13·8 vs. 7·7%). The Western blotting results demonstrated that p107 and p130 cell cycle protein expressions were higher in premature cells than in full‐term cells.Conclusion  These results suggest that the higher capacity of proliferation and early differentiation of premature UCB might not be related only to the amount of stem/progenitor cells but also to a different timing of cell cycle entry.
Cryopreservation and in vitro maturation of germinal vesicle stage oocytes of animals for application in assisted reproductive technology
Authors: YAMANAKA KEN‐ICHI , AONO NOBUYA , YOSHIDA HIROAKI , SATO EIMEI 
Published: May 2007

Cryopreservation, in vitro maturation, fertilization and culture can be applied to various processes across a wide range of species, that is, for the breeding and reproduction of farm animals, preservation of genetic variants in laboratory animals, and the conservation of wild species. In particular, the storage of oocytes by cryopreservation and IVM following cryopreservation, might become effective alternative assisted reproduction treatments for infertile patients. For example, in a clinical context, these techniques might be important for patients who are at risk of losing their ovarian function because of extirpative therapy, chemotherapy or radiation. Thus, it is important for assisted reproductive technology to improve IVM and cryopreservation techniques. In the present review, we introduce our recent studies on vitrification and IVM of germinal vesicle stage oocytes in animals.
Epigenetics in assisted reproductive technology
Authors: KATAGIRI YUKIKO , SHIBUI YUKIHIRO , NAGAO KOICHI , MIURA KAZUKIYO , MORITA MINETO 
Published: May 2007

It has been reported that the rates of epigenetic disorders such as Angelman syndrome (AS) and Beckwith–Wiedemann syndrome (BWS) are high in offspring conceived by assisted reproductive technology (ART). Angelman Syndrome is characterized by intellectual disability and BWS is known as large offspring syndrome (LOS). Weight abnormalities have also been reported in cloned animals. Possible factors underlying these findings include inherent gamete characteristics, influence of in vitro culture and peculiarity of ART methods. It is important to conclusively determine whether such epigenetic abnormalities are present in children conceived by ART, so as to consider the health of next generations.
In vitro growth and maturation of mouse oocyte‐granulosa cell complex from cryopreserved ovaries and achievement of pup birth
Authors: HASEGAWA AKIKO , KOYAMA KOJI 
Published: May 2007

Ovarian tissue banking is a feasible strategy for fertility preservation for young women after cancer treatments. Ovarian tissue, after thawing, is used for several options; orthotopic grafting (normal site), autologous heterotopic grafting and collection of ovarian follicles for culture. Recent reports of live birth encouraged clinicians and researchers to apply this technology to premature ovarian failure (POF) resulting from strong cancer therapy. Grafting, however, carries a risk of malignant cell recurrence. For safety, development of a culture method is necessary but optimum culturing conditions for less‐developed follicles abundant in the ovary are not well known. In the present article, the current status of ovarian tissue cryopreservation, and in vitro oocyte growth and maturation from the preserved ovaries are reviewed.
Successful pregnancy in ovariectomized mice using a combination of heterotopic autotransplantation of ovarian tissues and embryo transfer
Authors: MITSUI AKINORI , YOSHIZAWA MIDORI 
Published: May 2007

Aim:  The present report is the first to show that, after ovariectomy, female mice with autotransplanted ovarian sections can maintain pregnancy after embryo transfer (ET) independent of the transplantation site.Methods:  Three‐month‐old ICR females were ovariectomized, and sections from their own ovaries were transplanted either under their kidney capsule (KC group) or into a subcutaneous space (SC group) just after ovariectomy. In vitro fertilized blastocysts were transferred into uterine horns of the pseudopregnant mice that had received the transplanted ovarian tissues. Cesarean sections were carried out 17 days after ET to deliver any live fetuses that were present, and the numbers of implantation sites and fetuses were noted. Transplanted ovarian sections were removed and fixed for histological analysis.Results:  Of the 10 mice in the KC group that received 107 blastocysts, two females (20%) became pregnant; they showed 12 implantation sites (11.2%) and produced four pups (3.7%). In the SC group, 101 blastocysts were transferred to eight females, and three females (37.5%) became pregnant; there were seven implantation sites (6.9%), and three pups (3.0%) were born. There were no statistically significant differences between the two groups in any of the parameters evaluated. On histological examination, luteinization and vascularization of the ovarian sections that were transplanted in the pregnant SC and KC females were noted.Conclusion:  The pregnancy and full‐term fetal development were obtained in ovariectomized mice using a combination of heterotopic ovarian tissue autotransplantation and transfer of embryos produced by in vitro fertilization.
Seamounts: centres of endemism or species richness for ophiuroids?
Authors: O’Hara Timothy D. 
Published: May 2007

ABSTRACTAim  To test the hypotheses that seamounts exhibit high rates of endemism and/or species richness compared to surrounding areas of the continental slope and oceanic ridges.Location  The south‐west Pacific Ocean from 19–57° S to 143–171° E.Methods  Presence/absence museum data were compiled for seamount and non‐seamount areas at depths between 100 and 1500 m for the Ophiuroidea (brittle‐stars), an abundant and speciose group of benthic invertebrates. Large‐scale biogeographical gradients were examined through multivariate analyses at two spatial scales, at the scale of seamounts (< 1° of latitude/longitude) and regions (5–9°). The robustness of these patterns to spatially inconsistent sampling effort was tested using Monte Carlo‐style simulations. Levels of local endemism and species richness over numbers of samples were compared for seamount and non‐seamount areas using linear regressions. Non‐seamount populations were randomly generated from areas and depth ranges that reflected the typical sampling profile of seamounts.Results  Seamount ophiuroid assemblages did not exhibit elevated levels of species richness or narrow‐range endemism compared with non‐seamount areas. Seamounts can exhibit high overall species richness for low numbers of samples, particularly on seamounts supporting a dense coral matrix, but this does not increase with additional sampling at the rates found in non‐seamount areas. There were relatively few identifiable seamount specialists. In general, seamount faunas reflected those found at similar depths in surrounding areas, including the continental slope. Seamount and non‐seamount faunas within the study area exhibited congruent latitudinal and bathymetric species turnover.Main conclusions  Seamount faunas were variable for ophiuroid faunal composition, species richness and narrow‐range endemism, reflecting their environmental diversity and complex history. The continental slope was also variable, with some areas being particularly species rich. Broad geomorphological habitat categories such as ‘seamounts’ or ‘continental slope’ may be at the wrong scale to be useful for conservation planning.
Can niche‐based distribution models outperform spatial interpolation?
Authors: Bahn Volker , McGill Brian J. 
Published: May 2007

ABSTRACTAim  Distribution modelling relates sparse data on species occurrence or abundance to environmental information to predict the population of a species at any point in space. Recently, the importance of spatial autocorrelation in distributions has been recognized. Spatial autocorrelation can be categorized as exogenous (stemming from autocorrelation in the underlying variables) or endogenous (stemming from activities of the organism itself, such as dispersal). Typically, one asks whether spatial models explain additional variability (endogenous) in comparison to a fully specified habitat model. We turned this question around and asked: can habitat models explain additional variation when spatial structure is accounted for in a fully specified spatially explicit model? The aim was to find out to what degree habitat models may be inadvertently capturing spatial structure rather than true explanatory mechanisms.Location  We used data from 190 species of the North American Breeding Bird Survey covering the conterminous United States and southern Canada.Methods  We built 13 different models on 190 bird species using regression trees. Our habitat‐based models used climate and landcover variables as independent variables. We also used random variables and simulated ranges to validate our results. The two spatially explicit models included only geographical coordinates or a contagion term as independent variables. As another angle on the question of mechanism vs. spatial structure we pitted a model using related bird species as predictors against a model using randomly selected bird species.Results  The spatially explicit models outperformed the traditional habitat models and the random predictor species outperformed the related predictor species. In addition, environmental variables produced a substantial R2 in predicting artificial ranges.Main conclusions  We conclude that many explanatory variables with suitable spatial structure can work well in species distribution models. The predictive power of environmental variables is not necessarily mechanistic, and spatial interpolation can outperform environmental explanatory variables.
STRATEGIC NETWORKS AMONG SMALL FIRMS: IMPLICATIONS FOR STRATEGY RESEARCH METHODOLOGY*
Authors: Borch Odd Jarl , Arthur Michael B. 
Published: May 2007

ABSTRACTThis paper deals with the choice of methodological approach within strategic network research. Network‐oriented research approaches indicate a broader set of organizational and environmental variables. the issue of trust in network relations implicates contextual aspects such as the socio‐cultural foundation of people's interaction. the striving toward more complex, multi‐level models of strategy is seen to put a heavy burden on the development of adequate strategy research methods. the paper reports and interprets experience from a case study of inter‐organizational exchange governance in small firms. the discussion suggests a need for more in‐depth knowledge of cultural contexts, and of socio‐economic relations of actors within strategic networks. the paper recommends a search for new methodological inputs from other academic disciplines more experienced with human interaction research. In particular, methodological tools found within the field of social anthropology are recommended.
DIVISION HEADQUARTERS GO ABROAD ‐ A STEP IN THE INTERNATIONALIZATION OF THE MULTINATIONAL CORPORATION*
Authors: Forsgren Mats , Holm Ulf , Johanson Jan 
Published: May 2007

ABSTRACTWhy are division headquarters of multinational corporations in some cases located abroad? In the multinational corporation the physical location of division headquarters is a problematic issue because of the need for close links both to corporate headquarters and the foreign subsidiaries. This paper develops a model explaining this location as a consequence of power relations associated with the internationalization of the corporation and tests it on a sample of divisions of Swedish multinationals. the results support the view that power relations have an impact on location of division headquarters. One interesting result is the clear indication of countervailing forces, consisting of an attraction force of foreign dominant subsidiaries and a resisting force related to the interests of corporate headquarters.
MANAGERIAL AND OWNERSHIP SUCCESSION AND CORPORATE RESTRUCTURING: THE CASE OF MANAGEMENT BUY‐INS*
Authors: Robbie Ken , Wright Mike 
Published: May 2007

ABSTRACTThis paper addresses the effects on corporate restructuring of changing management and ownership. First, it synthesises a number of perspectives on corporate restructuring which involve managerial succession, voluntary restructuring, agency theory, incentives and entrepreneurship, to obtain insights into the relative impact of simultaneously changing either, neither or both management and ownership. Second, it uses case study evidence from management buy‐ins to examine the effects of changing both management and ownership. the evidence suggests that whilst management may be adequately incentivized, problems may arise in respect of information asymmetries, difficulties in matching entrepreneurs to the context and monitoring by venture capitalists, and implementation of strategies.
STREET‐LEVEL BUREAUCRACY AND PUBLIC ACCOUNTABILITY
Authors: HUPE PETER , HILL MICHAEL 
Published: May 2007

The concept of ‘street‐level bureaucracy’ was coined by Michael Lipsky (1980) as the common denominator for what would become a scholarly theme. Since then his stress on the relative autonomy of professionals has been complemented by the insight that they are working in a micro‐network of relations, in varying contexts. The conception of ‘governance’ adds a particular aspect to this: the multi‐dimensional character of a policy system as a nested sequence of decisions. Combining these views casts a different perspective on the ways street‐level bureaucrats are held accountable.In this article some axiomatic assumptions are drawn from the existing literature on the theme of street‐level bureaucracy and on the conception of governance. Acknowledging variety, and arguing for contextualized research, this results in a rethinking of the issue of accountability at the street level.
ARE ICTs IMPROVING TRANSPARENCY AND ACCOUNTABILITY IN THE EU REGIONAL AND LOCAL GOVERNMENTS? AN EMPIRICAL STUDY
Authors: PINA VICENTE , TORRES LOURDES , ROYO SONIA 
Published: May 2007

This paper conducts an empirical study about the effect of e‐government on transparency, openness and, hence, accountability in 15 countries of the EU. Thus the effects examined cover over 84 per cent of EU population. The population also represents the different types of public administration styles that exist in Western developed countries. The paper compares the development and sophistication of 318 government web sites at sub‐national level and tests the impact of contextual and organizational factors. The study refers to regional and local governments since they play a key role both in the national pattern of government and in administering welfare policies.Benchmarking studies of e‐government are undertaken regularly by consultancy firms. Most of this literature focuses on central and federal governments in terms of examining trends in digital government. However, little research has been conducted from a comparative perspective on analysing the movement of EU countries to digital government at a sub‐national level.
The Case of The School Meals Service
Authors: Ivatts John 
Published: May 2007

ABSTRACTSince 1979 British social policy has witnessed a marked abandonment of the post‐war principles of “universalism” inspired by the Beveridge Report. A deliberately residualist approach has been adopted and narrower criteria of selection have variously been imposed in areas of social welfare provision.This paper represents an attempt to assess and evaluate this trend in one area of welfare provision — the school meals service — by developing a historical analysis of an earlier period (1918–1939) when a residual model of welfare firmly held sway.From an examination of historical evidence relating to the inter‐war years, it is suggested that in important respects the present situation with regard to the provision of food for children while at school recreates many of the circumstances which pertained during that pre‐war period. Then as now selectivity, “targeting”, and fierce Treasury restrictions upon public expenditure were very much the order of the day.In the light of the problems of administrative fragmentation, and of the failures, inconsistencies and injustices of those policies which characterized school meals provision during that earlier period, it is concluded that contemporary developments within this service are disquieting, and a close scrutiny of the nutritional and other consequences is essential.
Limitations of ST analysis in clinical practice: three cases of intrapartum metabolic acidosis
Authors: Westerhuis MEMH , Kwee A , Van Ginkel AA , Drogtrop AP , Gyselaers WJA , Visser GHA 
Published: May 2007

Objective  To examine detailed intrapartum events in cases of neonatal metabolic acidosis despite monitoring using STAN® (cardiotocography [CTG] plus ST waveform analysis of fetal electrocardiogram [ECG]).Design  Retrospective case review.Setting  High‐risk pregnancies monitored by STAN®.Methods  Case note review was performed in newborns with metabolic acidosis where no significant ST changes in the fetal ECG occurred prior to birth.Main outcome measures  Metabolic acidosis.Results  Detailed review of three cases identified poor signal quality, difficulties in CTG interpretation, failure to comply with STAN® clinical guidelines and deterioration of the CTG without ECG alert as the leading causes of these adverse outcomes.Conclusions  The cases illustrate some of the pitfalls associated with the clinical application of the STAN® technology which prevent severe metabolic acidosis being eradicated completely. It may be useful to expand the STAN® guidelines protocol towards the identification of exceptional clinical situations, such as in our cases, and towards appropriate additional interventions, as this may lead to a further reduction in adverse neonatal outcomes.
Bdnfgene is a downstream target of Nurr1 transcription factor in rat midbrain neuronsin vitro
Authors: Volpicelli Floriana , Caiazzo Massimiliano , Greco Dario , Consales Claudia , Leone Luigi , Perrone‐Capano Carla , D’Amato Luca Colucci , Porzio Umberto di 
Published: May 2007

AbstractThe transcription factor Nurr1 is essential for the generation of midbrain dopaminergic neurons (mDA). Only a few Nurr1‐regulated genes have so far been identified and it remains unclear how Nurr1 influences the development and function of dopaminergic neurons. To identify novel Nurr1 target genes we have used genome‐wide expression profiling in rat midbrain primary cultures, enriched in dopaminergic neurons, following up‐regulation ofNurr1expression by depolarization. In this study we demonstrate that following depolarization the hyperexpression ofNurr1and the brain derived neurotrophic factor (BDNF) are phospholipase C‐ and protein kinase C‐dependent. We show thatBdnf, which encodes a neurotrophin involved also in the phenotypic maturation of mDA neurons, is a novel Nurr1 target gene. By RNA interference experiments we show that a decreasedNurr1expression is followed by tyrosine hydroxylase and BDNF mRNA and protein down‐regulation. Reporter gene assay experiments performed on midbrain primary cultures using fourBdnfpromoter constructs show thatBdnfis a direct target gene of Nurr1. Taken together, our findings suggest that Nurr1 might also influence the development and the function of midbrain dopaminergic neurons via direct regulation ofBdnfexpression.
p25/Cyclin‐dependent kinase 5 promotes the progression of cell death in nucleus of endoplasmic reticulum‐stressed neurons
Authors: Saito Taro , Konno Tsunetada , Hosokawa Tomohisa , Asada Akiko , Ishiguro Koichi , Hisanaga Shin‐ichi 
Published: May 2007

AbstractDysregulation of cyclin‐dependent kinase 5 (Cdk5) by cleavage of its activator p35 to p25 by calpain is involved in the neuronal cell death observed in neurodegenerative disorders, including Alzheimer’s disease. However, it is not yet clear how p25/Cdk5 induces cell death, although its cytosolic localization or extended half life are thought to be involved. We show here that endoplasmic reticulum (ER) stress causes the calpain‐dependent cleavage of p35 to p25 in primary cultured cortical neurons. Generation of p25 occurred at a cell death execution step in ER‐stressed neurons. p25 translocated to the nucleus in ER‐stressed neurons, whereas p35/Cdk5 was perinuclear in control neurons. Cdk5 inhibitors or dominant‐negative Cdk5 suppressed ER stress‐induced neuronal cell death. These findings indicate that p25/Cdk5 is a proapoptotic factor that promotes ER stress‐induced neuronal cell death in nuclei.