排序方式: 共有34条查询结果,搜索用时 31 毫秒
21.
Hillevi Helmfrid Andrew Haden Magnus Ljung 《Systemic Practice and Action Research》2008,21(2):105-131
We expand on the FMA model of inquiry elucidated by Checkland and Holwell (Syst Pract Act Res 11:9, 1998) and identify three
kinds of research: interactive Action Research (AR), extractive participatory research, and traditional science, that were
integrated into an interdisciplinary agro-environmental research project involving researchers from eight countries around
the Baltic Sea. The research project held the goal of creating scientific understanding of the ecological, economic and social
effects of the sustainable development of local food systems, while also having the explicit goal of implementing change in
the studied systems. Based on our experience working as action researchers in the project, we highlight the role that normative
goals and facilitation process competence play in complex interdisciplinary research projects. Our reflections focus on project
design, including the relation between AR and other kinds of research when employed in a single project, and includes reflections
on preconditions for stakeholder participation in AR projects. 相似文献
22.
Education policy and the heritability of educational attainment 总被引:1,自引:0,他引:1
A C Heath K Berg L J Eaves M H Solaas L A Corey J Sundet P Magnus W E Nance 《Nature》1985,314(6013):734-736
Many workers assume that genetically determined differences in intellectual ability will be influenced little by changes in educational policy or other environmental interventions. Others, however, have suggested that increasing equality of educational opportunity will lead to an increase in the heritability of educational attainment. The resolution of this issue has been delayed until now because of the extremely large sample sizes which would be required. Education data on twins and their parents, from the Norwegian twin panel, provide a unique opportunity to determine the impact on the heritability of educational attainment of the more liberal social and educational policies introduced in Norway after the Second World War. As reported here, for individuals born before 1940 there is a strong effect of family background on educational attainment, accounting for 47% of the variance, though genetic factors account for an additional 41% of the variance. For females born after 1940 and before 1961, the relative importance of genetic (38-45%) and familial environmental (41-50%) differences changes very little. For males born during the same period, the broad heritability of educational attainment has increased substantially (67-74%), and the environmental impact of family background has correspondingly decreased (8-10%). For males, at least, having well-educated parents no longer predicts educational success, as measured by duration of education, independent of the individual's own innate abilities. 相似文献
23.
Magnus Kjaergaard 《Cellular and molecular life sciences : CMLS》2017,74(17):3205-3224
Intrinsic disorder is common in integral membrane proteins, particularly in the intracellular domains. Despite this observation, these domains are not always recognized as being disordered. In this review, we will discuss the biological functions of intrinsically disordered regions of membrane proteins, and address why the flexibility afforded by disorder is mechanistically important. Intrinsically disordered regions are present in many common classes of membrane proteins including ion channels and transporters; G-protein coupled receptors (GPCRs), receptor tyrosine kinases and cytokine receptors. The functions of the disordered regions are many and varied. We will discuss selected examples including: (1) Organization of receptors, kinases, phosphatases and second messenger sources into signaling complexes. (2) Modulation of the membrane-embedded domain function by ball-and-chain like mechanisms. (3) Trafficking of membrane proteins. (4) Transient membrane associations. (5) Post-translational modifications most notably phosphorylation and (6) disorder-linked isoform dependent function. We finish the review by discussing the future challenges facing the membrane protein community regarding protein disorder. 相似文献
24.
Manske M Miotto O Campino S Auburn S Almagro-Garcia J Maslen G O'Brien J Djimde A Doumbo O Zongo I Ouedraogo JB Michon P Mueller I Siba P Nzila A Borrmann S Kiara SM Marsh K Jiang H Su XZ Amaratunga C Fairhurst R Socheat D Nosten F Imwong M White NJ Sanders M Anastasi E Alcock D Drury E Oyola S Quail MA Turner DJ Ruano-Rubio V Jyothi D Amenga-Etego L Hubbart C Jeffreys A Rowlands K Sutherland C Roper C Mangano V Modiano D Tan JC Ferdig MT Amambua-Ngwa A Conway DJ Takala-Harrison S Plowe CV 《Nature》2012,487(7407):375-379
Malaria elimination strategies require surveillance of the parasite population for genetic changes that demand a public health response, such as new forms of drug resistance. Here we describe methods for the large-scale analysis of genetic variation in Plasmodium falciparum by deep sequencing of parasite DNA obtained from the blood of patients with malaria, either directly or after short-term culture. Analysis of 86,158 exonic single nucleotide polymorphisms that passed genotyping quality control in 227 samples from Africa, Asia and Oceania provides genome-wide estimates of allele frequency distribution, population structure and linkage disequilibrium. By comparing the genetic diversity of individual infections with that of the local parasite population, we derive a metric of within-host diversity that is related to the level of inbreeding in the population. An open-access web application has been established for the exploration of regional differences in allele frequency and of highly differentiated loci in the P.?falciparum genome. 相似文献
25.
Gallagher FA Kettunen MI Day SE Hu DE Ardenkjaer-Larsen JH Zandt Ri Jensen PR Karlsson M Golman K Lerche MH Brindle KM 《Nature》2008,453(7197):940-943
As alterations in tissue pH underlie many pathological processes, the capability to image tissue pH in the clinic could offer new ways of detecting disease and response to treatment. Dynamic nuclear polarization is an emerging technique for substantially increasing the sensitivity of magnetic resonance imaging experiments. Here we show that tissue pH can be imaged in vivo from the ratio of the signal intensities of hyperpolarized bicarbonate (H(13)CO(3)(-)) and (13)CO(2) following intravenous injection of hyperpolarized H(13)CO(3)(-). The technique was demonstrated in a mouse tumour model, which showed that the average tumour interstitial pH was significantly lower than the surrounding tissue. Given that bicarbonate is an endogenous molecule that can be infused in relatively high concentrations into patients, we propose that this technique could be used clinically to image pathological processes that are associated with alterations in tissue pH, such as cancer, ischaemia and inflammation. 相似文献
26.
27.
Hu TT Pattyn P Bakker EG Cao J Cheng JF Clark RM Fahlgren N Fawcett JA Grimwood J Gundlach H Haberer G Hollister JD Ossowski S Ottilar RP Salamov AA Schneeberger K Spannagl M Wang X Yang L Nasrallah ME Bergelson J Carrington JC Gaut BS Schmutz J Mayer KF Van de Peer Y Grigoriev IV Nordborg M Weigel D Guo YL 《Nature genetics》2011,43(5):476-481
We report the 207-Mb genome sequence of the North American Arabidopsis lyrata strain MN47 based on 8.3× dideoxy sequence coverage. We predict 32,670 genes in this outcrossing species compared to the 27,025 genes in the selfing species Arabidopsis thaliana. The much smaller 125-Mb genome of A. thaliana, which diverged from A. lyrata 10 million years ago, likely constitutes the derived state for the family. We found evidence for DNA loss from large-scale rearrangements, but most of the difference in genome size can be attributed to hundreds of thousands of small deletions, mostly in noncoding DNA and transposons. Analysis of deletions and insertions still segregating in A. thaliana indicates that the process of DNA loss is ongoing, suggesting pervasive selection for a smaller genome. The high-quality reference genome sequence for A. lyrata will be an important resource for functional, evolutionary and ecological studies in the genus Arabidopsis. 相似文献
28.
Salmon Hillbertz NH Isaksson M Karlsson EK Hellmén E Pielberg GR Savolainen P Wade CM von Euler H Gustafson U Hedhammar A Nilsson M Lindblad-Toh K Andersson L Andersson G 《Nature genetics》2007,39(11):1318-1320
The dorsal hair ridge in Rhodesian and Thai Ridgeback dogs is caused by a dominant mutation that also predisposes to the congenital developmental disorder dermoid sinus. Here we show that the causative mutation is a 133-kb duplication involving three fibroblast growth factor (FGF) genes. FGFs play a crucial role in development, suggesting that the ridge and dermoid sinus are caused by dysregulation of one or more of the three FGF genes during development. 相似文献
29.
30.
Large recurrent microdeletions associated with schizophrenia 总被引:1,自引:0,他引:1
Stefansson H Rujescu D Cichon S Pietiläinen OP Ingason A Steinberg S Fossdal R Sigurdsson E Sigmundsson T Buizer-Voskamp JE Hansen T Jakobsen KD Muglia P Francks C Matthews PM Gylfason A Halldorsson BV Gudbjartsson D Thorgeirsson TE Sigurdsson A Jonasdottir A Jonasdottir A Bjornsson A Mattiasdottir S Blondal T Haraldsson M Magnusdottir BB Giegling I Möller HJ Hartmann A Shianna KV Ge D Need AC Crombie C Fraser G Walker N Lonnqvist J Suvisaari J Tuulio-Henriksson A Paunio T Toulopoulou T 《Nature》2008,455(7210):232-236
Reduced fecundity, associated with severe mental disorders, places negative selection pressure on risk alleles and may explain, in part, why common variants have not been found that confer risk of disorders such as autism, schizophrenia and mental retardation. Thus, rare variants may account for a larger fraction of the overall genetic risk than previously assumed. In contrast to rare single nucleotide mutations, rare copy number variations (CNVs) can be detected using genome-wide single nucleotide polymorphism arrays. This has led to the identification of CNVs associated with mental retardation and autism. In a genome-wide search for CNVs associating with schizophrenia, we used a population-based sample to identify de novo CNVs by analysing 9,878 transmissions from parents to offspring. The 66 de novo CNVs identified were tested for association in a sample of 1,433 schizophrenia cases and 33,250 controls. Three deletions at 1q21.1, 15q11.2 and 15q13.3 showing nominal association with schizophrenia in the first sample (phase I) were followed up in a second sample of 3,285 cases and 7,951 controls (phase II). All three deletions significantly associate with schizophrenia and related psychoses in the combined sample. The identification of these rare, recurrent risk variants, having occurred independently in multiple founders and being subject to negative selection, is important in itself. CNV analysis may also point the way to the identification of additional and more prevalent risk variants in genes and pathways involved in schizophrenia. 相似文献