| 1. |
- Schaaf, Cheri A, et al.
(författare)
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Regulation of the Drosophila Enhancer of split and invected-engrailed gene complexes by sister chromatid cohesion proteins
- 2009
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Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 4:7, s. e6202-
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Tidskriftsartikel (refereegranskat)abstract
- The cohesin protein complex was first recognized for holding sister chromatids together and ensuring proper chromosome segregation. Cohesin also regulates gene expression, but the mechanisms are unknown. Cohesin associates preferentially with active genes, and is generally absent from regions in which histone H3 is methylated by the Enhancer of zeste [E(z)] Polycomb group silencing protein. Here we show that transcription is hypersensitive to cohesin levels in two exceptional cases where cohesin and the E(z)-mediated histone methylation simultaneously coat the entire Enhancer of split and invected-engrailed gene complexes in cells derived from Drosophila central nervous system. These gene complexes are modestly transcribed, and produce seven of the twelve transcripts that increase the most with cohesin knockdown genome-wide. Cohesin mutations alter eye development in the same manner as increased Enhancer of split activity, suggesting that similar regulation occurs in vivo. We propose that cohesin helps restrain transcription of these gene complexes, and that deregulation of similarly cohesin-hypersensitive genes may underlie developmental deficits in Cornelia de Lange syndrome.
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| 2. |
- Ahmad, Tashfeen
(författare)
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Diabetic osteopathy : a study in the rat
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The present study on non-obese Goto-Kakizaki (GK) rats with type-2 diabetes and neuropathy was an attempt to describe and define pertinent features of diabetic osteopathy. Altogether, the study included 33 GK rats aged 12 and 20 months, and 36 age-matched Wistar rats as controls. All underwent test of glucose tolerance and nerve (sciatic) conduction velocity (NCV) showing that the diabetic rats had significantly higher blood glucose levels and lower NCV confirming the presence of diabetes and neuropathy. Skeletal features: Radiologic analysis of bone entailed X-ray, Dual Energy X-ray Absorptiometry (DEXA) and peripheral Quantitative Computed Tomography (pQCT). In diabetic rats, the length of humerus and height of vertebrae was reduced by 8%. The long bones exhibited endosteal erosion of the diaphyses up to 18% and periosteal expansion up to 8%. The vertebrae and metaphyses of long bones showed a decrease up to 24% in areal bone mineral density (BMD), whereas no decrease was seen in the diaphyses. Cross-sectional measurements by pQCT showed a decrease in volumetric BMD ranging from 33 to 62%, which exclusively pertained to trabecular bone (vertebrae, metaphyses), whereas volumetric BMD of the cortical bone of diaphyses was only marginally affected. The results indicate that juxta-articular bone in diabetes is substantially weaker, whereas diaphyseal cortical bone may be even stronger. Over all, the observations suggest that the diabetic skeleton is characterized by regional changes, which cannot be explained by systemic factors like calcium regulating hormones. Local bone turn-over is regulated by complex mechanisms involving cytokines, prostaglandins, growth factors and, also neuropeptides. Further analysis focused on the insulin-like growth factor (IGF) system and neuronal mediators in bone. IGF system: Immunoassays of IGF-I were done on serum, ankle samples and cortical preparations. In addition, the inhibitory IGF-I binding proteins, IGFBP-1 and -4 were analysed in serum. In diabetic rats, serum IGF-I was reduced by 18%, while IGFBP-1 and IGFBP-4 were increased by 89 and 20%, respectively. This complies with the lower BMD in the diabetic rats. In cortical bone, IGF-I was reduced by 38%, whereas no change was seen in ankles. The loss of IGF-I in cortical bone represents a novel finding. Given the cortical expansion observed in diabetic rats, the opposite was expected. Conceivably, loss of IGF-I results in endosteal erosion, which is compensated by periosteal expansion. Neuropeptides: The analyses focused on two sensory mediators, i.e. substance P (SP) and calcitonin gene- related peptide (CGRP), and one autonomic, i.e. neuropeptide Y (NPY). Immunohistochemistry was applied to ankles and tibial diaphyses, whereas radioimmunoassay (RIA) was used for separate preparations of periosteum, cortex and bone marrow from femur and tibia, whole ankles, dorsal root ganglia (DRG) and lumbar spinal cord. The morphological analysis showed SP, CGRP and NPY positive nerve fibers in bone and joints, which mostly were blood vessel related, although free terminals were also seen. In addition, NPY-positive hematopoietic cells were observed in the bone marrow. RIA revealed a significant decrease of CGRP, albeit not of SP, in DRG (-26%) and spinal cord (-29%) in the diabetic rats. As for bone, only NPY was significantly reduced, most evidently in bone marrow (-66%), but also in cortical bone (-36%) and ankles (-29%). Given the bone anabolic effects of CGRP and NPY, loss of these neuropeptides may prove, at least partly, to underlie the trabecular osteopenia and endocortical erosion observed in diabetic rats. Conclusion: The skeleton of diabetic rats with type-2 diabetes and neuropathy is characterized by regional changes of size, form, mineral content and density and concomitantly with regional abnormalities of the IGF- system and neuropeptides suggesting that also local factors beyond systemic play an important role in the development of diabetic osteopathy.
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| 3. |
- Ahmad, T., et al.
(författare)
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Frequency and outcomes of undiagnosed diabetes mellitus in patients presenting with acute myocardial infarction
- 2020
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Ingår i: Medical Forum Monthly. - : Medical Forum Monthly. - 1029-385X. ; 31:12, s. 3-7
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To find out frequency and outcomes of undiagnosed diabetes mellitus in patients presenting with acute ST elevation myocardial infarction (STEMI). Study Design: Descriptive / Cross-Sectional Study Place and Duration of study: This study was conducted at the Cardiology Department, Lady Reading Hospital, Peshawar from November 2018 to May 2019. Materials and Methods: Patient of either gender having age ranging between 30-75 years old with acute STEMI who present within 12 hours of symptoms and with no past history of documented diabetes mellitus were included in the study. Venous blood samples for laboratory data, including random blood sugar, two fasting blood sugar and HBA1c using hitachi modular evo p800 machine was done. Results: A total of 158 patients having acute STEMI were studied. Males were 68.4% (n=108).The mean age was 59.65 ±10.80 years. Frequency of undiagnosed diabetes mellitus was 31.64 % (n = 50). In non-diabetics stress hyperglycemia was found in 51.85 % (n=56) patients. Among various types of STEMI, anterior STEMI was more common presentation 34.1 % (n=54. p= 0.85). Mean HBA1C was 6.19 ± 1.87%. Frequency of Ventricular tachycardia (VT) was 22.2 % in which undiagnosed diabetics were n=18 (p=0.004).Ventricular fibrillation was present in 13.3 % patients with undiagnosed diabetics were n=14 (p=0.001). Frequency of AF was 13.9% (n=22) with undiagnosed diabetics having AF in n=13 (p=0.003). SVT was present in 5.7% (n=9) patients with not significant difference between two groups (p=0.017). Among various mechanical complications VSR was present in 10 % (n=16) of patients (p=0.001), cardiogenic shock in 11.1 % (n=18) patients (p=0.004), acute LVF was present in 15.8 % patients (p=0.017). Conclusion: In our study we concluded that one third of patients having acute ST elevation myocardial infarction have undiagnosed diabetes mellitus (31.64 %, n = 50). The most common complication was ventricular tachycardia among electrical complication and LVF among mechanical complication.
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| 4. |
- Ahmad, Tauseef, 1986, et al.
(författare)
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Methodology for Power-Aware Coherent Receiver Design
- 2013
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Ingår i: Optics InfoBase Conference Papers. - 2162-2701. ; , s. SPT4D.4-
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Konferensbidrag (refereegranskat)abstract
- We describe a methodology to design and evaluate DSP hardware for a coherent receiver. Important parameters that can be assessed include DSP power consumption and chip area.
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| 5. |
- Schaadt, K, et al.
(författare)
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Experiments on elastomechanical wave functions in chaotic plates and their statistical features
- 2003
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Ingår i: Physical Review E. - 1063-651X. ; 68:3: 036205
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Tidskriftsartikel (refereegranskat)abstract
- We measure the amplitude of the elastomechanical displacement at a fine grid of points on a free plate having the shape of a Sinai stadium. The obtained displacement field formally corresponds to a wave function in a quantum system. While the distribution of the squared amplitudes agrees with the prediction of random matrix theory (RMT), there is a strong deviation of the spatial correlator from the standard prediction for quantum chaotic systems. We show that this is due to the presence of two modes, leading to a beating phenomenon. We construct a proper extension of the spatial correlator within the framework of RMT.
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| 6. |
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| 7. |
- Coseri, Sergiu, et al.
(författare)
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One-shot carboxylation of microcrystalline cellulose in the presence of nitroxyl radicals and sodium periodate
- 2015
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Ingår i: RSC Advances. - : Royal Society of Chemistry (RSC). - 2046-2069. ; 5:104, s. 85889-85897
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Tidskriftsartikel (refereegranskat)abstract
- Water soluble cellulose derivatives are highly required products for many practical purposes, expanding the limited applications of pure cellulose caused by the highly ordered hydrogen bond network and high crystallinity. In this connection, this paper, presents a new approach to obtain water soluble carboxyl-functionalized cellulosic materials, combining two of the most common selective oxidation protocols for cellulose, i.e. nitroxyl mediated reaction and periodate oxidation, in a one-shot reaction. It was found that, under specific reaction conditions, fully oxidized, 2,3,6-tricarboxy cellulose can be obtained in large amounts. The other valuable oxidized fractions were found to possess large amounts of carboxylic groups, as determined by potentiometric titration. 13C-NMR evidenced the presence of three distinctive carboxylic groups in the fully oxidized product, whereas for the partially oxidized samples, 13C CP-MAS solid-state NMR did not detect any carbonyl signals. The oxidized products were characterized by means of FTIR and X-ray photoelectron spectroscopy (XPS). Moreover, the changes of the degree of polymerization occurring after oxidative treatments were viscometrically determined.
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| 8. |
- Cakir, B., et al.
(författare)
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IGF1, serum glucose, and retinopathy of prematurity in extremely preterm infants
- 2020
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Ingår i: Jci Insight. - : American Society for Clinical Investigation. - 2379-3708. ; 5:19
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND. Hyperglycemia, insulin insensitivity, and low IGF1 levels in extremely preterm infants are associated with an increased risk of retinopathy of prematurity (ROP), but the interactions are incompletely understood. METHODS. In 117 extremely preterm infants, serum glucose levels and parenteral glucose intake were recoded daily in the first postnatal week. Serum IGF1 levels were measured weekly. Mice with oxygen-induced retinopathy alone versus oxygen-induced retinopathy plus streptozotocin-induced hyperglycemia/hypoinsulinemia were assessed for glucose, insulin, IGF1, IGFBP1, and IGFBP3 in blood and liver. Recombinant human IGF1 was injected to assess the effect on glucose and retinopathy. RESULTS. The highest mean plasma glucose tertile of infants positively correlated with parenteral glucose intake [r (39) = 0.67, P < 0.0001]. IGF1 plasma levels were lower in the high tertile compared with those in low and intermediate tertiles at day 28 (P = 0.038 and P = 0.03). In high versus lower glucose tertiles, ROP was more prevalent (34 of 39 versus 19 of 39) and more severe (ROP stage 3 or higher; 71% versus 32%). In oxygen-induced retinopathy, hyperglycemia/hypoinsulinemia decreased liver IGF1 expression (P < 0.0001); rh-IGF1 treatment improved normal vascular regrowth (P = 0.027) and reduced neovascularization (P < 0.0001). CONCLUSION. In extremely preterm infants, high early postnatal plasma glucose levels and signs of insulin insensitivity were associated with lower IGF1 levels and increased ROP severity. In a hyperglycemia retinopathy mouse model, decreased insulin signaling suppressed liver IGF1 production, lowered serum IGF1 levels, and increased neovascularization. IGF1 supplementation improved retinal revascularization and decreased pathological neovascularization. The data support IGF1 as a potential treatment for prevention of ROP.
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| 9. |
- Light, Ann
(författare)
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Collaborative speculation : Anticipation, inclusion and designing counterfactual futures for appropriation
- 2021
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Ingår i: Futures. - : Elsevier. - 0016-3287 .- 1873-6378. ; 134
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Tidskriftsartikel (refereegranskat)abstract
- How do people become conversant with futures-in-the-making? This paper explores speculative design from the position that futures have agency in the present and therefore forms of speculation - as well as futures - need to be inclusive. Regarding this as a democratic right throws attention on engagement processes, noting that speculation is often centred on the designer's interests rather than seeding appropriation by publics. I argue that situating speculation in a way that is accessible for negotiation requires careful attention to the hybrid process + objectartifacts that result from designing both a provocation and a process for encountering it. My central case study describes one such hybrid artifact, a counterfactual workshop for considering futures by exploring different imagined pasts and making a journey towards alternative presents. This play of temporalities - and the accompanying methods for opening and narrowing the creative work of taking these journeys - suggest a means that speculative design might be situated with participants, thereby simultaneously reflecting on and mitigating the anticipatory nature of the materials. I deconstruct this instance of curating speculative artifacts to reveal not only its mechanisms, but the many points where engagement processes reflect political choices.
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| 10. |
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