| 3311. |
- Schwartz, Yuri B, et al.
(författare)
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Molecular characterization of the singed wings locus of Drosophila melanogaster
- 2004
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Ingår i: BMC Genetics. - : Springer Science and Business Media LLC. - 1471-2156. ; 5, s. 15-
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Tidskriftsartikel (refereegranskat)abstract
- It is not entirely clear from the present molecular analysis how the SWI protein may function in the ecdysone induced cascade. Currently all predictions agree in that SWI is very unlikely to be a nuclear protein. Thus it probably exercises its control of "late" ecdysone genes indirectly. Apparently the genetic regulation of ecdysone signaling is much more complex then was previously anticipated.
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| 3312. |
- Schwartz, Yuri B, et al.
(författare)
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Polycomb silencing mechanisms in Drosophila
- 2004
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Ingår i: Cold Spring Harbor Symposia on Quantitative Biology. - : Cold Spring Harbor Laboratory. - 0091-7451 .- 1943-4456. ; 69, s. 301-308
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Tidskriftsartikel (refereegranskat)
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| 3313. |
- Schwartz, Yuri B, et al.
(författare)
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Polytene chromosome interband DNA is organized into nucleosomes
- 2001
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Ingår i: Molecular Genetics and Genomics. - : Springer Science and Business Media LLC. - 1617-4615 .- 1617-4623. ; 265:2, s. 311-315
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Tidskriftsartikel (refereegranskat)abstract
- The molecular basis that underlies the maintenance of polytene chromosome banding pattern remains unclear. To test the possibility that the decondensed state of interbands is provoked by the absence of nucleosomes, we have subjected chromatin from the previously defined 61C7/C8 interband to digestion with micrococcal nuclease. We have demonstrated that interband DNA forms nucleosomes both in salivary glands and in the bulk of larval tissues. This finding strongly suggests that the difference in compaction between DNA in polytene chromosome bands and interbands results from differences that appear at the higher levels of chromatin organization.
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| 3314. |
- Scott, G, et al.
(författare)
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Effect of lidocaine and NMDA injections into the medial pontobulbar reticular formation on mastication evoked by cortical stimulation in anaesthetized rabbits
- 2003
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Ingår i: European Journal of Neuroscience. - : Wiley-Blackwell. - 0953-816X .- 1460-9568. ; 17:10, s. 2156-2162
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Tidskriftsartikel (refereegranskat)abstract
- Neurons of the dorsal nucleus reticularis pontis caudalis (nPontc) fire rhythmically during fictive mastication, while neurons of the ventral half tend to fire tonically (Westberg et al., 2001). This paper describes the changes in the pattern of rhythmical mastication elicited by stimulation of the sensorimotor cortex during inhibition or excitation of neurons in this nucleus and adjacent parts of nucleus reticularis gigantocellularis (Rgc) in the anaesthetized rabbit. Masticatory movements and electromyographic (EMG) activity of the masseter and digastric muscles produced by cortical stimulation were recorded before, during and after injections of a local anaesthetic (lidocaine) or excitatory amino acid N-methyl-d-aspartate (NMDA) into nPontc and Rgc through a microsyringe with attached microelectrode to record neuronal activity. Lidocaine inhibited local neurons and modified the motor program, and the effects varied with the site of injection. Most injections into the ventral half of nPontc increased cycle duration, digastric burst duration and burst area. The action of lidocaine in dorsal nPontc was more variable, although burst duration and area were often decreased. The effects on the muscle activity were always bilateral. Lidocaine block of the rostromedial part of Rgc had no effect on movements or on EMGs. Injections of NMDA excited local neurons and when injected into ventral nPontc, it completely blocked mastication. Dorsal injections either had no effect or increased cycle frequency, while decreasing burst duration and area. No increases in EMG burst duration or area were observed with NMDA. Our findings suggest that neurons of ventral nPontc tonically inhibit other parts of the central pattern generator during mastication, while dorsal neurons have mixed effects. We incorporated these findings into a new model of the masticatory central pattern generator.
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| 3315. |
- Scott, Åsa, et al.
(författare)
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Selection of a representative set of chemical accidents from a complex data matrix for the development of environment–accident index
- 2002
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Ingår i: Journal of Hazardous Materials. ; 91:1-3, s. 63-80
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Tidskriftsartikel (refereegranskat)abstract
- Chemical accidents often lead to negative consequences for the environment. Preparedness and proper actions are, therefore, essential components in order to minimise environmental effects. To assist and facilitate this work, a proposed planning tool, the environment–accident index (EAI), was formulated by Scott [J. Hazard. Mater. 61 (1998) 305]. As a result of a first validation of the index, based on 21 chemical accidents, the database was complemented with 42 additional accidents covering a broader spectrum of chemicals. The additional accidents were collected by means of an inquiry and their environmental consequences are, so far, unknown. The collected data had an overrepresentation of accidents involving petroleum products (69%). Because of the overrepresentation of this group of chemicals in the material, the data was skewed with respect to chemical properties. Since the model should be valid for a variety of chemical accidents, a method was needed which enabled a proper and unbiased selection of a representative subset of accidents to be used in development and validation of the model. For this purpose, the possibility to use multivariate data analysis in combination with statistical design was investigated. The result showed the feasibility of this method in the selection of a representative subset from a complex and skewed large dataset. Within the new dataset, 53% were accidents involving petroleum products and 47% involved other chemicals. The selected accidents will be used in further work to evaluate the environmental consequences, for model development and model validation.
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| 3316. |
- Segerholm, Christina
(författare)
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National Evaluations as Governing Instruments : How Do They Govern?
- 2001
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Ingår i: Evaluation. - : SAGE Publications. - 1356-3890 .- 1461-7153. ; 7:4, s. 427-438
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Tidskriftsartikel (refereegranskat)abstract
- The National Agency for Higher Education in Sweden carried out an evaluation, during 1995–1996, of all higher education programmes in care and nursing. The aim was to see if the programmes reached standards appropriate for higher education. Several care and nursing schools and programmes were found to be below the necessary standards, i.e. the criteria set by evaluators engaged in the national evaluation. According to those responsible for the programmes, the evaluation and its criteria were used at the local level to set out plans for development, even though the evaluation was criticized. Therefore in this article it is argued that national evaluations can work as national governing instruments, to support national policy. Two different theoretical frameworks are used to explain how actors at the local level are ‘governed’. Through this, it is believed that a more comprehensive understanding can be gained of how evaluation is related to governance.
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| 3317. |
- Segerholm, Christina
(författare)
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Researching Evaluation in National (State) Politics and Administration : A Critical Approach
- 2003
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Ingår i: American Journal of Evaluation. - : SAGE Publications. - 1098-2140 .- 1557-0878. ; 24:3, s. 353-372
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Tidskriftsartikel (refereegranskat)abstract
- Evaluation is increasingly taken as a public good, as an activity aimed at development and betterment. At the same time, evaluation is increasingly integrated in accountability movements and in institutionalized systems for governance. It is also embedded in a consumer-oriented New Public Management ideology. Against this background, it is high time to start critically examining evaluation itself as a phenomenon and practice. A conceptual framework for carrying out critical studies of evaluations in national (or state) settings is provided, and examples from previous such studies are given to illustrate possible findings. The framework is meant to capture forces that shape an evaluation process and the knowledge claims that result. These forces can restrict evaluation or enable it to provide a critical examination meant to be part of a public debate. By scrutinizing the premises for, the implementation of, and the impact of public-sector evaluations from a critical perspective, evaluators should gain a more thorough understanding of the various power plays of which evaluation is a part. Further discussions of and additional research on public-sector evaluation, to increase our knowledge and understanding of evaluation as a practice, are encouraged.
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| 3318. |
- Segerman, Anna, et al.
(författare)
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Adenovirus type 11 uses CD46 as a cellular receptor
- 2003
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Ingår i: Journal of Virology. - 0022-538X .- 1098-5514. ; 77:17, s. 9183-9191
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Tidskriftsartikel (refereegranskat)abstract
- The 51 human adenovirus serotypes are divided into six species (A to F). Many adenoviruses use the coxsackie-adenovirus receptor (CAR) for attachment to host cells in vitro. Species B adenoviruses do not compete with CAR-binding serotypes for binding to host cells, and it has been suggested that species B adenoviruses use a receptor other than CAR. Species B adenoviruses mainly cause disease in the respiratory tract, the eyes, and in the urinary tract. Here we demonstrate that adenovirus type 11 (Ad11; of species B) binds to Chinese hamster ovary (CHO) cells transfected with CD46 (membrane cofactor protein)-cDNA at least 10 times more strongly than to CHO cells transfected with cDNAs encoding CAR or CD55 (decay accelerating factor). Nonpermissive CHO cells were rendered permissive to Ad11 infection upon transfection with CD46-cDNA. Soluble Ad11 fiber knob but not Ad7 or Ad5 knob inhibited binding of Ad11 virions to CD46-transfected cells, and anti-CD46 antibodies inhibited both binding of and infection by Ad11. From these results we conclude that CD46 is a cellular receptor for Ad11.
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| 3319. |
- Segerman, A, et al.
(författare)
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Adenovirus types 11p and 35p show high binding efficiencies for committed hematopoietic cell lines and are infective to these cell lines.
- 2000
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Ingår i: Journal of Virology. - 0022-538X .- 1098-5514. ; 74:3, s. 1457-67
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Tidskriftsartikel (refereegranskat)abstract
- Hematopoietic cells are attractive targets for gene therapy. However, no satisfactory vectors are currently available. A major problem with the most commonly used adenovirus vectors, based on adenovirus type 2 (Ad2) or Ad5, is their low binding efficiency for hematopoietic cells. In this study we identify two adenovirus serotypes with high affinity for hematopoietic cells. The binding efficiency of prototype serotypes Ad4p, Ad11p, and Ad35p for different committed hematopoietic cell lines representing T cells (Jurkat), B cells (DG75), monocytes (U937-2), myeloblasts (K562), and granulocytes (HL-60) was evaluated and compared to that of Ad5v, the commonly used adenovirus vector, using flow cytometry. In contrast to Ad5v, which bound to less than 10% of the cells in all experiments, Ad11p and Ad35p showed high binding efficiency for all of the different hematopoietic cell lines. Ad4p bound to the lymphocytic cell lines to some extent but less well to the myelomonocytic cell lines. The abilities of the different serotypes to infect, replicate, and form complete infectious particles in the hematopoietic cell lines were also investigated by immunostaining, (35)S labeling of viral proteins, and titrations of cell lysates. Ad11p and Ad35p infected the highest proportion of cells, and Ad11p infected all of the cell lines investigated. The Ad11p hexon was expressed equally well in K562 and A549 cells. Jurkat cells also showed high levels of expression of Ad11p hexons, but the production of infectious particles was low. The binding properties of virions were correlated to their ability to infect and be expressed.
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| 3320. |
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