| 1791. |
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| 1792. |
- Souihi, Nabil, et al.
(författare)
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Near-infrared chemical imaging (NIR-CI) on roll compacted ribbons and tablets - multivariate mapping of physical and chemical properties
- 2015
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Ingår i: International Journal of Pharmaceutics. - : Elsevier BV. - 0378-5173 .- 1873-3476. ; 483:1-2, s. 200-211
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Tidskriftsartikel (refereegranskat)abstract
- Near-infrared chemical imaging (NIR-CI) is an attractive technique within the pharmaceutical industry, where tools are continuously in demand to assess the quality of the intermediate and final products. The present paper demonstrates how NIR-CI in combination with multivariate methods was utilized to spatially map physical properties and content of roll compacted ribbons and tablets. Additionally, extracted textural parameters from tablet images were correlated to the design parameters of the roll compaction process as well as to the physical properties of the granules. The results established the use of NIR-CI as a complementary nondestructive tool to determine the ribbon density and map the density distribution across the width and along the length of the ribbons. For the tablets, the compaction pressure developed during compression increased with the lateral distance from the center. Therefore, NIR-CI can be an effective tool to provide information about the spatial distribution of the compaction pressures on the surface of the tablet. Moreover, low roll compaction roll force correlated to a heterogeneous type of texture in the API chemical image. Overall, texture analysis of the tablets enabled efficient investigation of the spatial variation and could be used to advance process understanding. Finally, orthogonal projections to latent structures (O2PLS) model facilitated the understanding of the interrelationships between textural features, design parameters and physical properties data by separately joint and unique variations.
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| 1793. |
- Sountoulidis, Alexandros, et al.
(författare)
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A topographic atlas defines developmental origins of cell heterogeneity in the human embryonic lung
- 2023
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Ingår i: Nature Cell Biology. - : Springer Nature. - 1465-7392 .- 1476-4679.
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Tidskriftsartikel (refereegranskat)abstract
- Sountoulidis et al. provide a spatial gene expression atlas of human embryonic lung during the first trimester of gestation and identify 83 cell identities corresponding to stable cell types or transitional states. The lung contains numerous specialized cell types with distinct roles in tissue function and integrity. To clarify the origins and mechanisms generating cell heterogeneity, we created a comprehensive topographic atlas of early human lung development. Here we report 83 cell states and several spatially resolved developmental trajectories and predict cell interactions within defined tissue niches. We integrated single-cell RNA sequencing and spatially resolved transcriptomics into a web-based, open platform for interactive exploration. We show distinct gene expression programmes, accompanying sequential events of cell differentiation and maturation of the secretory and neuroendocrine cell types in proximal epithelium. We define the origin of airway fibroblasts associated with airway smooth muscle in bronchovascular bundles and describe a trajectory of Schwann cell progenitors to intrinsic parasympathetic neurons controlling bronchoconstriction. Our atlas provides a rich resource for further research and a reference for defining deviations from homeostatic and repair mechanisms leading to pulmonary diseases.
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| 1794. |
- Sountoulidis, Alexandros, et al.
(författare)
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SCRINSHOT enables spatial mapping of cell states in tissue sections with single-cell resolution
- 2020
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Ingår i: PLoS biology. - : Public Library of Science (PLoS). - 1544-9173 .- 1545-7885. ; 18:11
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Tidskriftsartikel (refereegranskat)abstract
- Changes in cell identities and positions underlie tissue development and disease progression. Although single-cell mRNA sequencing (scRNA-Seq) methods rapidly generate extensive lists of cell states, spatially resolved single-cell mapping presents a challenging task. We developed SCRINSHOT (Single-Cell Resolution IN Situ Hybridization On Tissues), a sensitive, multiplex RNA mapping approach. Direct hybridization of padlock probes on mRNA is followed by circularization with SplintR ligase and rolling circle amplification (RCA) of the hybridized padlock probes. Sequential detection of RCA-products using fluorophore-labeled oligonucleotides profiles thousands of cells in tissue sections. We evaluated SCRINSHOT specificity and sensitivity on murine and human organs. SCRINSHOT quantification of marker gene expression shows high correlation with published scRNA-Seq data over a broad range of gene expression levels. We demonstrate the utility of SCRINSHOT by mapping the locations of abundant and rare cell types along the murine airways. The amenability, multiplexity, and quantitative qualities of SCRINSHOT facilitate single-cell mRNA profiling of cell-state alterations in tissues under a variety of native and experimental conditions.
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| 1795. |
- Sponseller, Ryan A., et al.
(författare)
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Headwater Mires Constitute a Major Source of Nitrogen (N) to Surface Waters in the Boreal Landscape
- 2018
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Ingår i: Ecosystems (New York. Print). - : Springer. - 1432-9840 .- 1435-0629. ; 21:1, s. 31-44
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Tidskriftsartikel (refereegranskat)abstract
- Nutrient exports from soils have important implications for long-term patterns of nutrient limitation on land and resource delivery to aquatic environments. While plant-soil systems are notably efficient at retaining limiting nutrients, spatial and temporal mismatches in resource supply and demand may create opportunities for hydrologic losses to occur. Spatial mismatches may be particularly important in peat-forming landscapes, where the development of a two-layer vertical structure can isolate plant communities on the surface from resource pools that accumulate at depth. Our objectives were to test this idea in northern Sweden, where nitrogen (N) limitation of terrestrial plants is widespread, and where peat-forming, mire ecosystems are dominant features of the landscape. We quantified vertical patterns of N chemistry in a minerogenic mire, estimated the seasonal and annual hydrologic export of organic and inorganic N from this system, and evaluated the broader influence of mire cover on N chemistry across a stream network. Relatively high concentrations of ammonium (up to 2 mg l(-1)) were observed in groundwater several meters below the peat surface, and N was routed to the outlet stream along deep, preferential flowpaths. Areal estimates of inorganic N export from the mire were several times greater than from an adjacent, forested catchment, with markedly higher loss rates during the growing season, when plant N demand is ostensibly greatest. At broader scales, mire cover was positively correlated with long-term concentrations of inorganic and organic N in streams across the drainage network. This study provides an example of how mire formation and peat accumulation can create broad-scale heterogeneity in nutrient supply and demand across boreal landscapes. This mismatch allows for hydrologic losses of reactive N that are independent of annual plant demand and potentially important to receiving lakes and streams.
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| 1796. |
- Stansfeld, S A, et al.
(författare)
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Implications of road traffic and aircraft noise exposure and children’s cognition and health (RANCH) study results for classroom acoustics.
- 2005
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Ingår i: Journal of the Acoustical Society of America. ; 117:4, s. 2363-
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Tidskriftsartikel (refereegranskat)abstract
- Studies in West London have found associations between aircraft noise exposure and children’s’ cognitive performance. This has culminated in the RANCH Study examining exposure-effect associations between aircraft and road traffic noise exposure and cognitive performance and health. The RANCH project, the largest cross-sectional study of noise and children’s health, examined 2844 children, 9-10 years old from 89 schools around three major airports: in the Netherlands, Spain and the United Kingdom. Children were selected by external aircraft and road traffic noise exposure at school predicted from noise contour maps, modeling and on-site measurements. A substudy indicated high internal levels of noise within classrooms. Schools were matched for socioeconomic position within countries. Cognitive and health outcomes were measured by standardized tests and questionnaires administered in the classroom. A parental questionnaire collected information on socioeconomic position, parental education and ethnicity. Linear exposure-effect associations were found between chronic aircraft noise exposure and impairment of reading comprehension and recognition memory, maintained after adjustment for mothers education, socioeconomic factors, longstanding illness and classroom insulation. Road traffic noise exposure was linearly associated with episodic memory. The implications of these results for children’s’ learning environments will be discussed.
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| 1797. |
- Starkhammar, Josefin, et al.
(författare)
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Design and benchmark tests of a hydrophone array system for whale echolocation recordings
- 2012
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Ingår i: Open Journal of Acoustics. - : Scientific Research Publishing, Inc.. - 2162-5794 .- 2162-5786. ; 2:3, s. 121-130
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Tidskriftsartikel (refereegranskat)abstract
- This paper describes in depth the design and application considerations of a computer based measurement system enabling 1 MS/s simultaneous sampling of 47 hydrophones for cross sectional recordings of echolocation beams of toothed whales (Odontocetes). An earlier prototype version of the system has previously only been presented as a brief proof of principle that did not offer a complete description of the software and hardware solution. Crucial hardware and software design considerations of the further developed system include the re-arm times of the burst mode sampling and the dual-core distributed execution of the software components. The rearm time was measured to 283 µs, using a 550 µs long sample window around each click. This enables burst mode sampling of clicks with an inter-click interval as short as 833 µs. It is shown through both synthetic benchmark tests of the system and through field measurements of bottlenose dolphins (Tursiops truncatus) and a beluga whale (Delphinapterus leucas) that it is capable of acquiring, analyzing and visualizing data in run-time. It operates effectively also in highly reverberant surroundings like concrete pools and shallow waters. Burst mode sampling allows the system to block reflections with 0.3 - 0.5 m longer propagation paths than the direct path. It is suggested that the system’s compliance to reverberant recording sites makes it valuable in future dolphin echolocation studies.
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| 1798. |
- Starkhammar, Josefin, et al.
(författare)
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Editorial: 47-channel burst-mode recording hydrophone system enabling measurements of the dynamic echolocation behavior of free-swimming dolphins
- 2009
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Ingår i: Journal of the Acoustical Society of America. - : A I P Publishing LLC. - 0001-4966 .- 1520-8524. ; 126:3, s. 959-962
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Detailed echolocation behavior studies on free-swimming dolphins require a measurement system that incorporates multiple hydrophones (often andgt; 16). However, the high data flow rate of previous systems has limited their usefulness since only minute long recordings have been manageable. To address this problem, this report describes a 47-channel burst-mode recording hydrophone system that enables highly resolved full beamwidth measurements on multiple free-swimming dolphins during prolonged recording periods. The system facilitates a wide range of biosonar studies since it eliminates the need to restrict the movement of animals in order to study the fine details of their sonar beams.
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| 1799. |
- Starkhammar, Josefin, et al.
(författare)
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Separating overlapping click trains originating from multiple individuals in echolocation recordings
- 2011
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Ingår i: JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA. - : Acoustical Society of America. - 0001-4966 .- 1520-8524. ; 129:1, s. 458-466
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Tidskriftsartikel (refereegranskat)abstract
- Recordings of the acoustic activity of free-swimming groups of echolocating dolphins increase the likelihood of collecting overlapping click trains, originating from multiple individuals, in the same set of data. In order to evaluate the click properties of each individual based on such recordings it is necessary to identify which clicks originate from which animal. This paper suggests a computationally efficient strategy to separate overlapping click trains originating from multiple free-swimming bottlenose dolphins, enabling echolocation analysis at an individual level on several animals. This technique is based on sequential matching of the frequency spectra of successive clicks. The clicks are grouped together as individual click trains if the correlation coefficients between clicks are higher than a pre-set threshold level. The robustness of the algorithm is tested by adding artificially generated white Gaussian noise and comparing the results with other comparable commonly used methods based on inter-click intervals, centroid frequencies, and amplitude levels. The described method is applicable to a variety of experimental and observational contexts, e. g., those regarding echolocation development of calves, the hypothesized acoustic "etiquette" among dolphins when investigating the same object, and the possible occurrence of eavesdropping in large dolphin pods.
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| 1800. |
- Starkhammar, Josefin, et al.
(författare)
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The dynamics of the bottlenose dolphin sonar beam.
- 2008
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Ingår i: Journal of the Acoustical Society of America. - : Acoustical Society of America (ASA). - 1520-8524 .- 0001-4966. ; 124:4
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Tidskriftsartikel (refereegranskat)abstract
- Much research on dolphin echolocation has focused on animals that have been trained to remain stationary or to carry a device that allows the animals to move but restricts the location of the sonar beam. In such cases, a small number of hydrophones measures sonar characteristics while dolphins solve echolocation tasks. As a result, much is known about the beam axis but relatively little is known about other parts of the beam. One reason for this disparity is that it has been difficult to interpret the results from off axis measurements using a small number of hydrophones (that may or may not sample simultaneously). In this paper, we report results from a system of 47 hydrophones in a 0.75 x 0.75 m(2) matrix that allowed measurements to be made at multiple locations in the beam simultaneously, with a sample rate of 1 Msamples. The system both visualizes and records echolocation clicks in real time across the whole cross section of the beam, hence allowing the full dynamics of the sonar beam to be revealed. As a demonstration of the system's utility, we present results obtained with the system to assess the acoustic properties of clicks produced spontaneously by free-swimming dolphins.
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