175 research outputs found
The poverty of journal publishing
The article opens with a critical analysis of the dominant business model of for-profit, academic publishing, arguing that the extraordinarily high profits of the big publishers are dependent upon a double appropriation that exploits both academic labour and universities’ financial resources. Against this model, we outline four possible responses: the further development of open access repositories, a fair trade model of publishing regulation, a renaissance of the university presses, and, finally, a move away from private, for-profit publishing companies toward autonomous journal publishing by editorial boards and academic associations. </jats:p
OXYGEN UPTAKE, THE CIRCULATORY SYSTEM, AND HAEMOGLOBIN FUNCTION IN THE INTERTIDAL POLYCHAETE TEREBELLA HAPLOCHAETA (Ehlers)
Abstract: The intertidal polychaete Terebelh: haphJchaeta (Ehlers) shows a high degree of oxyregulation in declining pO., when confined to its burrow at low tide. This response is achieved by a number of adaptations to the respiratory system. The worm ventilates its burrow in a headward direction by rhythmical contractions of the body. The rate of these pulsatior~ increases at low pO., and assists the circulation of the coelomic and vascular fluids. Haemoglobin in the vessels has a high affinity for oxygen and a sigmoidal equilibrium curve. Both the shape and position of the oxygen-binding curve are sensitive to changes in pH, pCO2, and temperature in a way that suggests augmentation of oxygen delivery tit low tide. The concentration of haemoglobin in the vessels is high and is further raised following warm acclimation, presumably to meet an increase in oxygen demand. The ultrastructure of the gills and blood vessels indicates a design for function at low oxygen tensions where diffusion distances must be short and surface areas large in order to enhance the rate of diffusion of oxygen from the near environment
Processing of the precursor of protamine P2 in mouse. Peptide mapping and N-terminal sequence analysis of intermediates
Mouse Ribosomal RNA Genes Contain Multiple Differentially Regulated Variants
Previous cytogenetic studies suggest that various rDNA chromosomal loci are not equally active in different cell types. Consistent with this variability, rDNA polymorphism is well documented in human and mouse. However, attempts to identify molecularly rDNA variant types, which are regulated individually (i.e., independent of other rDNA variants) and tissue-specifically, have not been successful. We report here the molecular cloning and characterization of seven mouse rDNA variants (v-rDNA). The identification of these v-rDNAs was based on restriction fragment length polymorphisms (RFLPs), which are conserved among individuals and mouse strains. The total copy number of the identified variants is less than 100 and the copy number of each individual variant ranges from 4 to 15. Sequence analysis of the cloned v-rDNA identified variant-specific single nucleotide polymorphisms (SNPs) in the transcribed region. These SNPs were used to develop a set of variant-specific PCR assays, which permitted analysis of the v-rDNAs' expression profiles in various tissues. These profiles show that three v-rDNAs are expressed in all tissues (constitutively active), two are expressed in some tissues (selectively active), and two are not expressed (silent). These expression profiles were observed in six individuals from three mouse strains, suggesting the pattern is not randomly determined. Thus, the mouse rDNA array likely consists of genetically distinct variants, and some are regulated tissue-specifically. Our results provide the first molecular evidence for cell-type-specific regulation of a subset of rDNA
Are ribosomal DNA clusters rearrangement hotspots? A case study in the genus Mus (Rodentia, Muridae)
<p>Abstract</p> <p>Background</p> <p>Recent advances in comparative genomics have considerably improved our knowledge of the evolution of mammalian karyotype architecture. One of the breakthroughs was the preferential localization of evolutionary breakpoints in regions enriched in repetitive sequences (segmental duplications, telomeres and centromeres). In this context, we investigated the contribution of ribosomal genes to genome reshuffling since they are generally located in pericentromeric or subtelomeric regions, and form repeat clusters on different chromosomes. The target model was the genus <it>Mus </it>which exhibits a high rate of karyotypic change, a large fraction of which involves centromeres.</p> <p>Results</p> <p>The chromosomal distribution of rDNA clusters was determined by <it>in situ </it>hybridization of mouse probes in 19 species. Using a molecular-based reference tree, the phylogenetic distribution of clusters within the genus was reconstructed, and the temporal association between rDNA clusters, breakpoints and centromeres was tested by maximum likelihood analyses. Our results highlighted the following features of rDNA cluster dynamics in the genus <it>Mus</it>: i) rDNA clusters showed extensive diversity in number between species and an almost exclusive pericentromeric location, ii) a strong association between rDNA sites and centromeres was retrieved which may be related to their shared constraint of concerted evolution, iii) 24% of the observed breakpoints mapped near an rDNA cluster, and iv) a substantial rate of rDNA cluster change (insertion, deletion) also occurred in the absence of chromosomal rearrangements.</p> <p>Conclusions</p> <p>This study on the dynamics of rDNA clusters within the genus <it>Mus </it>has revealed a strong evolutionary relationship between rDNA clusters and centromeres. Both of these genomic structures coincide with breakpoints in the genus <it>Mus</it>, suggesting that the accumulation of a large number of repeats in the centromeric region may contribute to the high level of chromosome repatterning observed in this group. However, the elevated rate of rDNA change observed in the chromosomally invariant clade indicates that the presence of these sequences is insufficient to lead to genome instability. In agreement with recent studies, these results suggest that additional factors such as modifications of the epigenetic state of DNA may be required to trigger evolutionary plasticity.</p
The European Center of Science Productivity: Research Universities and Institutes in France, Germany, and the United Kingdom
Growth in scientific productivity over the 20th century resulted significantly from three major countries in European science—France, Germany, and the United Kingdom. We chart the development of universities and research institutes that bolster Europe’s key position in global science. We uncover both stable and dynamic patterns of productivity in the fields of STEM, including health, over the twentieth century. On-going internationalization of higher education and science has been accompanied by increasing competition and collaboration. Despite policy goals to foster innovation and expand research capacity, policies cannot fully account for the differential growth of scientific productivity we chart from 1975 to 2010. Our neoinstitutional framework facilitates explanation of differences in institutional settings, organizational forms, and organizations that produce the most European research. We measure growth of published peer-reviewed articles indexed in Thomson Reuters’ Science Citation Index Expanded (SCIE).
Organizational forms vary in their contributions, with universities accounting for nearly half but rising in France; ultrastable in Germany at four-fifths, and growing at around two-thirds in the UK. Differing institutionalization pathways created the conditions necessary for continuous, but varying growth in scientific productivity in the European center of global science. The research university is central in all three countries, and we identify organizations leading in research output. Few analyses explicitly compare across time, space, and different levels of analysis. We show how important European science has been to overall global science productivity. In-depth comparisons, especially the organizational fields and forms in which science is produced, are crucial if policy is to support research and development
Taking stock of 10 years of published research on the ASHA programme: Examining India’s national community health worker programme from a health systems perspective
Background: As India’s accredited social health activist (ASHA) community health worker (CHW) programme enters its second decade, we take stock of the research undertaken and whether it examines the health systems interfaces required to sustain the programme at scale.
Methods: We systematically searched three databases for articles on ASHAs published between 2005 and 2016. Articles that met the inclusion criteria underwent analysis using an inductive CHW–health systems interface framework.
Results: A total of 122 academic articles were identified (56 quantitative, 29 mixed methods, 28 qualitative, and 9 commentary or synthesis); 44 articles reported on special interventions and 78 on the routine ASHA program. Findings on special interventions were overwhelmingly positive, with few negative or mixed results. In contrast, 55% of articles on the routine ASHA programme showed mixed findings and 23% negative, with few indicating overall positive findings, reflecting broader system constraints. Over half the articles had a health system perspective, including almost all those on general ASHA work, but only a third of those with a health condition focus. The most extensively researched health systems topics were ASHA performance, training and capacity-building, with very little research done on programme financing and reporting, ASHA grievance redressal or peer communication. Research tended to be descriptive, with fewer influence, explanatory or exploratory articles, and no predictive or emancipatory studies. Indian institutions and authors led and partnered on most of the research, wrote all the critical commentaries, and published more studies with negative results.
Conclusion: Published work on ASHAs highlights a range of small-scale innovations, but also showcases the challenges faced by a programme at massive scale, situated in the broader health system. As the programme continues to evolve, critical comparative research that constructively feeds back into programme reforms is needed, particularly related to governance, intersectoral linkages, ASHA solidarity, and community capacity to provide support and oversight
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