2,227 research outputs found

    Polyphony in Architecture

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    Based on interviews with a number of architects and managers from a wide range of organizations, we characterize how architecture is perceived in practice. We identify three groups of organizations that differ with respect to their level of architectural thinking and the alignment of business and IT on architectural issues. Analysis of the interviews further indicates that these three groups differ in the architecture aspects and critical success factors they emphasize. Our results provide a starting point for assessing architecture maturity and alignment within organizations, and can be used to help harmonize different architectural tunes played within organizations

    Chemical Probes to Control and Visualize Lipid Metabolism in the Brain

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    CONSPECTUS: Signaling lipids, such as the endocannabinoids, play an important role in the brain. They regulate synaptic transmission and control various neurophysiological processes, including pain sensation, appetite, memory formation, stress, and anxiety. Unlike classical neurotransmitters, lipid messengers are produced on demand and degraded by metabolic enzymes to control their lifespan and signaling actions. Chemical biology approaches have become one of the main driving forces to study and unravel the physiological role of lipid messengers in the brain. Here, we review how the development and use of chemical probes has allowed one to study endocannabinoid signaling by (i) inhibiting the biosynthetic and metabolic enzymes; (ii) visualizing the activity of these enzymes; and (iii) controlling the release and transport of the endocannabinoids. Activity-based probes were instrumental to guide the discovery of highly selective and in vivo active inhibitors of the biosynthetic (DAGL, NAPE-PLD) and metabolic (MAGL, FAAH) enzymes of endocannabinoids. These inhibitors allowed one to study the role of these enzymes in animal models of disease. For instance, the DAGL-MAGL axis was shown to control neuroinflammation and the NAPE-PLD-FAAH axis to regulate emotional behavior. Activity-based protein profiling and chemical proteomics were essential to guide the drug discovery and development of compounds targeting MAGL and FAAH, such as ABX-1431 (Lu AG06466) and PF-04457845, respectively. These experimental drugs are now in clinical trials for multiple indications, including multiple sclerosis and post-traumatic stress disorders. Activity-based probes have also been used to visualize the activity of these lipid metabolizing enzymes with high spatial resolution in brain slices, thereby showing the cell type-specific activity of these lipid metabolizing enzymes. The transport, release, and uptake of signaling lipids themselves cannot, however, be captured by activity-based probes in a spatiotemporal controlled manner. Therefore, bio-orthogonal lipids equipped with photoreactive, photoswitchable groups or photocages have been developed. These chemical probes were employed to investigate the protein interaction partners of the endocannabinoids, such as putative membrane transporters, as well as to study the functional cellular responses within milliseconds upon irradiation. Finally, genetically encoded sensors have recently been developed to monitor the real-time release of endocannabinoids with high spatiotemporal resolution in cultured neurons, acute brain slices, and in vivo mouse models. It is anticipated that the combination of chemical probes, highly selective inhibitors, and sensors with advanced (super resolution) imaging modalities, such as PharmacoSTORM and correlative light-electron microscopy, will uncover the fundamental basis of lipid signaling at nanoscale resolution in the brain. Furthermore, chemical biology approaches enable the translation of these fundamental discoveries into clinical solutions for brain diseases with aberrant lipid signaling.Molecular Physiolog

    "One time I fell, but I didn't have to cry." A qualitative study on everyday physical complaints in children

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    OBJECTIVE: Young children experience physical complaints, like abdominal pain or minor injuries from playing, almost every day. These experiences may shape how they deal with health issues later in life. While models exist to explain illness perception in adults, information is lacking on the perspective of young children. This qualitative study aimed to explore important themes in the experience of everyday physical complaints in four- and five-year-old children, using children as informants. STUDY DESIGN: 30 semi-structured interviews were performed in which four- and five-year-old children were questioned about their experiences with everyday physical complaints. The interviews were double coded using Atlas.ti and subsequently qualitative content analysis was used to define themes. RESULTS: All participating children were able to elaborate on their experiences with physical complaints. Three themes emerged from the interviews: causes of complaints, appraisal of complaints, and implications of complaints. In their appraisal of complaints, four- and five-year-old children made a distinction between visible and invisible complaints and real or pretended complaints. CONCLUSION: Four- and five-year-old children can already give details about their experiences with everyday physical complaints. They have developed ideas about the causes and implications of complaints and try to make an appraisal

    Long-term dietary intervention with low Phe and/or a specific nutrient combination improve certain aspects of brain functioning in phenylketonuria (PKU)

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    Introduction In phenylketonuria (PKU), a gene mutation in the phenylalanine metabolic pathway causes accumulation of phenylalanine (Phe) in blood and brain. Although early introduction of a Phe-restricted diet can prevent severe symptoms from developing, patients who are diagnosed and treated early still experience deficits in cognitive functioning indicating shortcomings of current treatment. In the search for new and/or additional treatment strategies, a specific nutrient combination (SNC) was postulated to improve brain function in PKU. In this study, a long-term dietary intervention with a low-Phe diet, a specific combination of nutrients designed to improve brain function, or both concepts together was investigated in male and female BTBR PKU and WT mice. Material & methods 48 homozygous wild-types (WT, +/+) and 96 PKU BTBRPah2 (-/-) male and female mice received dietary interventions from postnatal day 31 till 10 months of age and were distributed in the following six groups: high Phe diet (WT C-HP, PKU C-HP), high Phe plus specific nutrient combination (WT SNC-HP, PKU SNC-HP), PKU low-Phe diet (PKU C-LP), and PKU low-Phe diet plus specific nutrient combination (PKU SNC- LP). Memory and motor function were tested at time points 3, 6, and 9 months after treatment initiation in the open field (OF), novel object recognition test (NOR), spatial object recognition test (SOR), and the balance beam (BB). At the end of the experiments, brain neurotransmitter concentrations were determined. Results In the NOR, we found that PKU mice, despite being subjected to high Phe conditions, could master the task on all three time points when supplemented with SNC. Under low Phe conditions, PKU mice on control diet could master the NOR at all three time points, while PKU mice on the SNC supplemented diet could master the task at time points 6 and 9 months. SNC supplementation did not consistently influence the performance in the OF, SOR or BB in PKU mice. The low Phe diet was able to normalize concentrations of norepinephrine and serotonin; however, these neurotransmitters were not influenced by SNC supplementation. Conclusion This study demonstrates that both a long-lasting low Phe diet, the diet enriched with SNC, as well as the combined diet was able to ameliorate some, but not all of these PKU-induced abnormalities. Specifically, this study is the first long-term intervention study in BTBR PKU mice that shows that SNC supplementation can specifically improve novel object recognition

    Shot Noise in Linear Macroscopic Resistors

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    We report on a direct experimental evidence of shot noise in a linear macroscopic resistor. The origin of the shot noise comes from the fluctuation of the total number of charge carriers inside the resistor associated with their diffusive motion under the condition that the dielectric relaxation time becomes longer than the dynamic transit time. Present results show that neither potential barriers nor the absence of inelastic scattering are necessary to observe shot noise in electronic devices.Comment: 10 pages, 5 figure

    The perspective of people with axial spondyloarthritis regarding physiotherapy : room for the implementation of a more active approach

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    Objectives. Physiotherapy is recommended in the management of people with axial spondyloarthritis (axSpA), with new insights into its preferred content and dosage evolving. The aim of this study was to describe the use and preferences regarding individual and group physiotherapy among people with axSpA. Methods. A cross-sectional survey was conducted among people with axSpA living in The Netherlands (NL) and Switzerland (CH). Results. Seven hundred and thirteen people with axSpA participated (56.7% male, median age 55 years, median Assessment of Spondyloarthritis International Society Health Index score 4.2). Response rates were 45% (n¼206) in NL and 29% in CH (n¼507). Of these participants, 83.3% were using or had been using physiotherapy. Individual therapy only was used or had been used by 36.7%, a combination of individual plus land- and water-based group therapy by 29.1% and group therapy by only 5.3%. Fewer than half of the participants attending individual therapy reported active therapy (such as aerobic, muscle strength and flexibility exercises). Although the majority (75.9%) were not aware of the increased cardiovascular risk, participants showed an interest in cardiovascular training, either individually or in a supervised setting. If supervised, a majority, in CH (75.0%) more than in NL (55.7%), preferred supervision by a specialized physiotherapist. Conclusion. The majority of people with axSpA use or have used physiotherapy, more often in an individual setting than in a group setting. The content of individual therapy should be more active; in both therapy settings, aerobic exercises should be promoted. In particular, enabling people with axSpA to perform exercises independently would meet their needs and might enhance their daily physical activity

    Anomalous crossover between thermal and shot noise in macroscopic diffusive conductors

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    We predict the existence of an anomalous crossover between thermal and shot noise in macroscopic diffusive conductors. We first show that, besides thermal noise, these systems may also exhibit shot noise due to fluctuations of the total number of carriers in the system. Then we show that at increasing currents the crossover between the two noise behaviors is anomalous, in the sense that the low frequency current spectral density displays a region with a superlinear dependence on the current up to a cubic law. The anomaly is due to the non-trivial coupling in the presence of the long range Coulomb interaction among the three time scales relevant to the phenomenon, namely, diffusion, transit and dielectric relaxation time.Comment: 4 pages, 2 figure
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