| 1. |
- Phillips, Helen R. P., et al.
(författare)
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Global distribution of earthworm diversity
- 2019
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 366:6464, s. 480-
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Tidskriftsartikel (refereegranskat)abstract
- Soil organisms, including earthworms, are a key component of terrestrial ecosystems. However, little is known about their diversity, their distribution, and the threats affecting them. We compiled a global dataset of sampled earthworm communities from 6928 sites in 57 countries as a basis for predicting patterns in earthworm diversity, abundance, and biomass. We found that local species richness and abundance typically peaked at higher latitudes, displaying patterns opposite to those observed in aboveground organisms. However, high species dissimilarity across tropical locations may cause diversity across the entirety of the tropics to be higher than elsewhere. Climate variables were found to be more important in shaping earthworm communities than soil properties or habitat cover. These findings suggest that climate change may have serious implications for earthworm communities and for the functions they provide.
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| 2. |
- Jacob, S, et al.
(författare)
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In vivo Ca2+ dynamics in single pancreatic β cells
- 2020
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Ingår i: FASEB journal : official publication of the Federation of American Societies for Experimental Biology. - 1530-6860. ; 34:1, s. 945-959
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Tidskriftsartikel (refereegranskat)
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| 3. |
- Leibiger, B, et al.
(författare)
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Ectopic Leptin Production by Intraocular Pancreatic Islet Organoids Ameliorates the Metabolic Phenotype of ob/ob Mice
- 2021
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Ingår i: Metabolites. - : MDPI AG. - 2218-1989. ; 11:6
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Tidskriftsartikel (refereegranskat)abstract
- The pancreatic islets of Langerhans consist of endocrine cells that secrete peptide hormones into the blood circulation in response to metabolic stimuli. When transplanted into the anterior chamber of the eye (ACE), pancreatic islets engraft and maintain morphological features of native islets as well as islet-specific vascularization and innervation patterns. In sufficient amounts, intraocular islets are able to maintain glucose homeostasis in diabetic mice. Islet organoids (pseudo-islets), which are formed by self-reassembly of islet cells following disaggregation and genetic manipulation, behave similarly to native islets. Here, we tested the hypothesis that genetically engineered intraocular islet organoids can serve as production sites for leptin. To test this hypothesis, we chose the leptin-deficient ob/ob mouse as a model system, which becomes severely obese, hyperinsulinemic, hyperglycemic, and insulin resistant. We generated a Tet-OFF-based beta-cell-specific adenoviral expression construct for mouse leptin, which allowed efficient transduction of native beta-cells, optical monitoring of leptin expression by co-expressed fluorescent proteins, and the possibility to switch-off leptin expression by treatment with doxycycline. Intraocular transplantation of islet organoids formed from transduced islet cells, which lack functional leptin receptors, to ob/ob mice allowed optical monitoring of leptin expression and ameliorated their metabolic phenotype by improving bodyweight, glucose tolerance, serum insulin, and C-peptide levels.
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| 4. |
- Mercier, Bertrand, et al.
(författare)
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Sensor Networks for Cognitive Radio: Theory and System Design
- 2008
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Ingår i: Proceedings of the ICT Mobile and Wireless Communications Summit (ICT'08).
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Konferensbidrag (refereegranskat)abstract
- Following current trends towards dynamic spectrum allocation and cognitive radio, this paper proposes a new approach and innovative techniques to support the coexistence of licensed and unlicensed wireless users in a same area. Theproposed concept, called Sensor Network aided Cognitive Radio, consists of a wireless sensor network able to assist the cognitive network by providing information on the current spectrum occupancy. This concept, that will address various operational scenarios in the future networks, involves a set of advanced wireless communications techniques like spectrum sensing, interference management, cognitive radio reconfiguration management, cooperative communications, end-to-end protocol design and cross-layer optimisation. All these enabling techniques together will form a compound system able to improve the spectrum use in a significant way. The main target scenario we consider is the use of nomadic cognitive radios in urban and suburban areas. Our objective is to develop a proof-of-concept – scheduled in 2010 – of the Sensor Network aided Cognitive Radio technology by implementing such techniques and integrating them on a hardware radio platform, which will allow us to assess the efficiency of the technology in a realistic environment.
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| 5. |
- Mishra, Kumar Vijay, et al.
(författare)
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Toward Millimeter-Wave Joint Radar Communications A signal processing perspective
- 2019
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Ingår i: IEEE signal processing magazine (Print). - : Institute of Electrical and Electronics Engineers (IEEE). - 1053-5888 .- 1558-0792. ; 36:5, s. 100-114
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Tidskriftsartikel (refereegranskat)abstract
- Synergistic design of communications and radar systems with common spectral and hardware resources is heralding a new era of efficiently utilizing a limited radio-frequency (RF) spectrum. Such a joint radar communications (JRC) model has advantages of low cost, compact size, less power consumption, spectrum sharing, improml performance, and safety due to enhanced information sharing. Today, millimeter-wave (mm-wave) communications have emerged as the preferred technology for short distance wireless links because they provide transmission bandwidth that is several gigahertz wide. This band is also promising for short-range radar applications, which benefit from the high-range resolution arising from large transmit signal bandwidths. Signal processing techniques are critical to the implementation of mm-wave JRC systems. Major challenges are joint waveform design and performance criteria that would optimally trade off between communications and radar functionalities. Novel multiple-input, multiple-output (MIMO) signal processing techniques are required because mm-wave JRC systems employ large antenna arrays. There are opportunities to exploit recent advances in cognition, compressed sensing, and machine learning to reduce required resources and dynamically allocate them with low overheads. This article provides a signal processing perspective of mm-wave JRC systems with an emphasis on waveform design.
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| 6. |
- Saarnio, Ville K., et al.
(författare)
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Development of functionalized SYBR green II related cyanine dyes for viral RNA detection
- 2020
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Ingår i: Dyes and Pigments. - : Elsevier BV. - 0143-7208 .- 1873-3743. ; 177
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Tidskriftsartikel (refereegranskat)abstract
- Fluorescent probes for sensing nucleic acids have found widespread use in the field of cell and molecular biology. However, probes combined with potential for post-synthetic conjugation, e.g. for intra-endosomal measurements of RNA, are unavailable. Herein we developed cyanine dyes that can be conjugated to viral capsid or other targets. First, we solved the crystal structure of SYBR Green II. The structural elucidation of this commonly used RNA probe provided the basis for synthesizing similar molecules with much desired function for post-synthetic conjugation. To address this need, cyanine dyes were prepared using an alternative synthesis protocol. All studied compounds showed considerable brightness upon binding to nucleic acids. However, regardless of the common chromophore on the dyes, the observed fluorescence emission intensities varied significantly, where methyl-substituted dye 1 gave values higher than SYBR Green II, whereas compounds 2–5 containing undecyl spacers had lower values. Studying the structure-activity relationship revealed the longer alkyl chains to induce slight perturbation in dye intercalation, as well as demand larger binding area on the nucleic acid lattice, explaining these differences. To study the potential biological use of the dyes, the RNA genome of enterovirus echovirus 1 was studied in vitro with the probes. A novel method employing the low binding space requirement of 1 was developed to determine the single-to-double-stranded RNA ratio of a sample, whereas compound 4 was covalently bound to the viral capsid and used successfully to monitor the viral RNA release from within the capsid. The presented results open new possibilities for preparation and use of SYBR Green-based nucleic acid probes to further apply these compounds for increasingly demanding targeting in biological contexts.
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| 9. |
- Willekens, Stefanie M. A., et al.
(författare)
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An MR-based brain template and atlas for optical projection tomography and light sheet fluorescence microscopy in neuroscience
- 2024
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Ingår i: Frontiers in Neuroscience. - : Frontiers Media S.A.. - 1662-4548 .- 1662-453X. ; 18
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Optical Projection Tomography (OPT) and light sheet fluorescence microscopy (LSFM) are high resolution optical imaging techniques, ideally suited for ex vivo 3D whole mouse brain imaging. Although they exhibit high specificity for their targets, the anatomical detail provided by tissue autofluorescence remains limited.Methods: T1-weighted images were acquired from 19 BABB or DBE cleared brains to create an MR template using serial longitudinal registration. Afterwards, fluorescent OPT and LSFM images were coregistered/normalized to the MR template to create fusion images.Results: Volumetric calculations revealed a significant difference between BABB and DBE cleared brains, leading to develop two optimized templates, with associated tissue priors and brain atlas, for BABB (OCUM) and DBE (iOCUM). By creating fusion images, we identified virus infected brain regions, mapped dopamine transporter and translocator protein expression, and traced innervation from the eye along the optic tract to the thalamus and superior colliculus using cholera toxin B. Fusion images allowed for precise anatomical identification of fluorescent signal in the detailed anatomical context provided by MR.Discussion: The possibility to anatomically map fluorescent signals on magnetic resonance (MR) images, widely used in clinical and preclinical neuroscience, would greatly benefit applications of optical imaging of mouse brain. These specific MR templates for cleared brains enable a broad range of neuroscientific applications integrating 3D optical brain imaging.
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| 10. |
- Willekens, Stefanie M. A., et al.
(författare)
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Optically Cleared Umeå brain template : An MR-based brain template and atlas for optical projection and light sheet fluorescence microscopy
- 2024
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Optical projection tomography (OPT) and light sheet fluorescence microscopy (LSFM) are high-resolution optical imaging techniques operating in the mm-cm range, ideally suited forex vivo3D whole mouse brain imaging. Although these techniques exhibit high sensitivity and specificity for antibody-labeled targets, the provided anatomical information remains limited. To allow anatomical mapping of fluorescent signal in whole brain, we developed a novel magnetic resonance (MR) – based template with its associated tissue priors and atlas labels, specifically designed for brains subjected to tissue processing protocols required for 3D optical imaging. We investigated the effect of tissue pre-processing and clearing on brain size and morphology and developed optimized templates for BABB/Murrays clear (OCUM) and DBE/iDISCO (iOCUM) cleared brains. By creating optical-(i)OCUM fusion images using our mapping procedure, we localized dopamine transporter and translocator protein expression and tracer innervation from the eye to the lateral geniculate nucleus of thalamus and superior colliculus. These fusion images allowed for precise anatomical identification of fluorescent signal in discrete brain areas. As such, these templates enable applications in a broad range of research areas integrating optical 3D brain imaging by providing an MR template for cleared brains.
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