| 1. |
- Ahmed, M., et al.
(författare)
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Search for the lepton-family-number nonconserving decay μ +→e +γ
- 2002
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Ingår i: Physical Review D. - : American Physical Society. - 1550-7998 .- 1550-2368. ; 65:11
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Tidskriftsartikel (refereegranskat)abstract
- The MEGA experiment, which searched for the muon- and electron-number violating decay μ +→e + γ, is described. The spectrometer system, the calibrations, the data taking procedures, the data analysis, and the sensitivity of the experiment are discussed. The most stringent upper limit on the branching ratio, B(μ + →e + γ)<1.2×10 -11 with 90% confidence, is derived from a likelihood analysis.
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| 2. |
- Kim, H. U., et al.
(författare)
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New pollen-specific receptor kinases identified in tomato, maize and Arabidopsis : the tomato kinases show overlapping but distinct localization patterns on pollen tubes
- 2002
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Ingår i: Plant Molecular Biology. - 0167-4412 .- 1573-5028. ; 50:1, s. 1-16
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Tidskriftsartikel (refereegranskat)abstract
- We previously characterized LePRK1 and LePRK2, pollen-specific receptor kinases from tomato (Muschietti et al., 1998). Here we identify a similar receptor kinase from maize, ZmPRK1, that is also specifically expressed late in pollen development, and a third pollen receptor kinase from tomato, LePRK3. LePRK3 is less similar to LePRK1 and LePRK2 than either is to each other. We used immunolocalization to show that all three LePRKs localize to the pollen tube wall, in partially overlapping but distinct patterns. We used RT-PCR and degenerate primers to clone homologues of the tomato kinases from other Solanaceae. We deduced features diagnostic of pollen receptor kinases and used these criteria to identify family members in the Arabidopsis database. RT-PCR confirmed pollen expression for five of these Arabidopsis candidates; two of these are clearly homologues of LePRK3. Our results reveal the existence of a distinct pollen-specific receptor kinase gene family whose members are likely to be involved in perceiving extracellular cues during pollen tube growth.
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| 3. |
- Kozaki, Koichi, et al.
(författare)
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Blockade of platelet-derived growth factor or its receptors transiently delays but does not prevent fibrous cap formation in ApoE null mice.
- 2002
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Ingår i: The American journal of pathology. - 0002-9440. ; 161:4, s. 1395-407
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Tidskriftsartikel (refereegranskat)abstract
- Platelet-derived growth factor (PDGF) is a potent stimulant of smooth muscle cell migration and proliferation in culture. To test the role of PDGF in the accumulation of smooth muscle cells in vivo, we evaluated ApoE -/- mice that develop complex lesions of atherosclerosis. Fetal liver cells from PDGF-B-deficient embryos were used to replace the circulating cells of lethally irradiated ApoE -/- mice. One month after transplant, all monocytes in PDGF-B -/- chimeras are of donor origin (lack PDGF), and no PDGF-BB is detected in circulating platelets, primary sources of PDGF in lesions. Although lesion volumes are comparable in the PDGF-B +/+ and -/- chimeras at 35 weeks, lesions in PDGF-B -/- chimeras contain mostly macrophages, appear less mature, and have a reduced frequency of fibrous cap formation as compared with PDGF-B +/+ chimeras. However, after 45 weeks, smooth muscle cell accumulation in fibrous caps is indistinguishable in the two groups. Comparison of elicited peritoneal macrophages by RNase protection assay shows an altered cytokine and cytokine receptor profile in PDGF-B -/- chimeras. ApoE -/- mice were also treated for up to 50 weeks with a PDGF receptor antagonist that blocks all three PDGF receptor dimers. Blockade of the PDGF receptors similarly delays, but does not prevent, accumulation of smooth muscle and fibrous cap formation. Thus, elimination of PDGF-B from circulating cells or blockade of PDGF receptors does not appear sufficient to prevent smooth muscle accumulation in advanced lesions of atherosclerosis.
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| 4. |
- Skoog, T, et al.
(författare)
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Plasma tumour necrosis factor-alpha and early carotid atherosclerosis in healthy middle-aged men
- 2002
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Ingår i: European Heart Journal. - : Oxford University Press (OUP). - 1522-9645 .- 0195-668X. ; 23:5, s. 376-383
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Tidskriftsartikel (refereegranskat)abstract
- Aims Tumour necrosis factor-alpha (TNF-alpha) is a proinflammatory cytokine, which is implicated in some metabolic disorders and may play a role in the development of cardiovascular disease. We examined whether plasma TNF-alpha is related to established cardiovascular risk indicators, plasma levels of soluble cellular adhesion molecules and carotid artery intima-media thickness determined by ultrasound examination in a population-based cohort of 96 healthy 50-year-old men. Methods and Results TNF-alpha and cellular adhesion molecules were measured with enzyme-linked immunosorbent assays. Plasma TNF-alpha concentration was associated with systolic and diastolic blood pressure, degrees of alimentary lipaemia, plasma very low density lipoprotein triglyceride, low density lipoprotein (LDL) cholesterol concentrations and peak LDL particle size. Two indices of insulin resistance as well as all soluble cellular adhesion molecules correlated positively with TNF-alpha. The plasma TNF-alpha concentration was associated with common carotid intima-media thickness in univariate analysis. In contrast, soluble E-selectin and postprandial triglycerides, but not TNF-alpha, were independent determinants of common carotid intima-media thickness. Conclusion The plasma TNF-alpha concentration is associated with degrees of early atherosclerosis and correlates with metabolic and cellular perturbations that are considered important for the vascular process.
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| 5. |
- Tang, Ou, et al.
(författare)
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Planning and replanning the master production schedule under demand uncertainty
- 2002
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Ingår i: International Journal of Production Economics. - 0925-5273 .- 1873-7579. ; 78:3, s. 323-334
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Tidskriftsartikel (refereegranskat)abstract
- The Master Production Schedule (MPS) is essential in maintaining customer service levels and stabilising production planning in a Material Requirements Planning (MRP) environment. Traditionally, an MPS is derived from a demand forecast and aggregate production plan but the associated cost to cover demand uncertainty is usually not considered. Another difficulty in the MPS is its planning frequency. Frequent changes in the MPS reduce productivity whereas a long-term frozen MPS results in a poor service level and an unfavourable inventory situation. This paper first investigates the possibility to establish a method for planning the MPS under stochastic demand. Secondly, it aims to evaluate the value of replanning actions. Finally, it provides a model for estimating appropriate MPS parameters such as the length of the replanning interval and the length of the interval to freeze the plan. © 2002 Elsevier Science B.V. All rights reserved.
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| 6. |
- Tang, Ou, et al.
(författare)
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Rescheduling considerations for production planning using control theory
- 2002
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Ingår i: International journal of industrial engineering. - 1072-4761 .- 1943-670X. ; 9:3, s. 258-264
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Tidskriftsartikel (refereegranskat)abstract
- The rescheduling problem has been addressed recently in studies of ours. The alternatives to reschedule or to stay are compared incorporating a rescheduling cost. This paper applies control theory methodology to model this type of production-inventory problem. Its objective is to evaluate the response of the system when rescheduling activities are triggered. Attempts have also been made to evaluate the rescheduling cost from the system response aspect, although these do not pretend to capture all costs of rescheduling.
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| 7. |
- Tang, W. H., et al.
(författare)
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A cysteine-rich extracellular protein, LAT52, interacts with the extracellular domain of the pollen receptor kinase LePRK2
- 2002
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Ingår i: The Plant Cell. - : Oxford University Press (OUP). - 1040-4651 .- 1532-298X. ; 14:9, s. 2277-2287
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Tidskriftsartikel (refereegranskat)abstract
- Pollen germination and pollen tube growth are thought to require extracellular cues, but how these cues are perceived and transduced remains largely unknown. Pollen receptor kinases are plausible candidates for this role; they might bind extracellular ligands and thereby mediate cytoplasmic events required for pollen germination and pollen tube growth. To search for pollen-expressed ligands for pollen receptor kinases, we used the extracellular domains of three pollen-specific receptor kinases of tomato (LePRK1, LePRK2, and LePRK3) as baits in a yeast two-hybrid screen. We identified numerous secreted or plasma membrane-bound candidate ligands. One of these, the Cys-rich protein LAT52, was known to be essential during pollen hydration and pollen tube growth. We used in vivo coimmunoprecipitation to demonstrate that LAT52 was capable of forming a complex with LePRK2 in pollen and to show that the extracellular domain of LePRK2 was sufficient for the interaction. Soluble LAT52 can exist in differently sized forms, but only the larger form can interact with LePRK2. We propose that LAT52 might be a ligand for LePRK2.
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| 8. |
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