371 results on '"Johannisson, P."'
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2. Single layer centrifugation as a method for bacterial reduction in bull semen for assisted reproduction
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Cojkic, Aleksandar, Hansson, Ingrid, Johannisson, Anders, Axner, Eva, and Morrell, Jane M.
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- 2024
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3. Definition and Quantification of Shock/Impact/Transient Vibrations
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Johannisson, Pontus and Lindell, Hans
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Electrical Engineering and Systems Science - Signal Processing - Abstract
Vibration injury in the hand-arm system from hand-held machines is one of the most common occupational health injuries and causes severe and often chronic nerve and vascular injury to the operator. Machines emitting shock vibrations, e.g., impact wrenches have since long been identified as a special risk factor. In legislative and standard texts the terms shock, impact, and transient vibration are frequently used to underline the special risk associated with these kinds of vibrations. In spite of this, there is no mathematically stringent definition what a shock vibration is or how the amplitude of the shock is defined. This lack of definitions is the subject of this article. This document discusses a number of candidate definitions for a vibration shock index (VSI) that quantifies different vibration signals in terms of how localized they are in the time domain. The VSI is intended to be used to classify and compare different vibration sources. The VSI is independent of the vibration level, i.e., it is unchanged if the vibration signal is rescaled. The traditional root mean square method to determine the vibration level will not produce a value representative for the shocks occurring in a signal with high VSI. Thus, there is a need for a complementing quantification method for the localized signal parts. Possible definitions for such a vibration shock level (VSL) are suggested. A problem formulation is first stated together with a description of the approach used for designing the VSI and the VSL. After this, model signals are defined, which are used to discuss and evaluate the different candidate definitions. Then, a number of candidate definitions are discussed, leading up to a conclusion on which candidate definitions that are promising for experimental evaluation.
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- 2022
4. Sperm quality and in vitro fertilizing ability of boar spermatozoa stored at 4 °C versus conventional storage for 1 week
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Ida Hallberg, Jane M. Morrell, Pack Malaluang, Anders Johannisson, Ylva Sjunnesson, and Denise Laskowski
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porcine ,in vitro embryo production ,semen storage ,artificial insemination ,long term boar semen storage ,Veterinary medicine ,SF600-1100 - Abstract
IntroductionSince boar spermatozoa show a marked deterioration in sperm quality when cooled, insemination doses are usually stored at 16–18 °C. However, maintaining this temperature during transport of semen doses is challenging, particularly during the summer months. An alternative could be to store the doses at 4 °C if cold-shock to the sperm could be prevented. The objective of this study was to evaluate boar sperm quality and fertility in in vitro fertilization after storage in AndroStar Premium at 4 °C for 1 week.MethodsInsemination doses (n = 9) in AndroStar Premium from a commercial boar semen collection station were transported to the laboratory at approximately 20 °C. At the laboratory, sperm quality evaluation and was preformed and each dose was split; half of each ejaculate was stored in a climate-controlled box at 16–18 °C, the other was slowly cooled to 4 °C. Both samples were stored for 1 week before further sperm quality evaluation and in vitro fertilization (IVF) were performed. Mean values were tested using generalized linear regression, with treatment and boar as fixed factors; p ≤ 0.05 was considered significant.ResultsSperm membrane integrity (mean ± sem: 91 ± 0.05 and 83 ± 0.09% for 16 and 4 °C, respectively) and superoxide production (6.79 ± 2.37 and 13.54 ± 6.23% for 16 and 4 °C, respectively), were different between treatments. The DNA fragmentation index was lower in cold-stored samples than in conventionally stored samples (3.74 ± 2.25 and 7.40 ± 3.36% for 4 and 16 °C, respectively). The numbers of oocytes developing to blastocyst on Day 6 (mean ± sd: 9.0 ± 8.0 and 6.0 ± 5.0%, for storage at 16 and 4 °C, respectively) were not different between treatments.DiscussionTherefore, storage of boar semen doses in AndroStar Premium at 4 °C for up to 7 days would be a viable alternative to current praxis.
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- 2024
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5. MmWave 6D Radio Localization with a Snapshot Observation from a Single BS
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Nazari, Mohammad A., Seco-Granados, Gonzalo, Johannisson, Pontus, and Wymeersch, Henk
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Electrical Engineering and Systems Science - Signal Processing ,Computer Science - Information Theory - Abstract
Accurate and ubiquitous localization is crucial for a variety of applications such as logistics, navigation, intelligent transport, monitoring, control, and also for the benefit of communications. Exploiting millimeter-wave (mmWave) signals in 5G and Beyond 5G systems can provide accurate localization with limited infrastructure. We consider the single base station (BS) localization problem and extend it to 3D position and 3D orientation estimation of an unsynchronized multi-antenna user equipment (UE), using downlink multiple-input multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) signals. Through a Fisher information analysis, we show that the problem is often identifiable, provided that there is at least one multipath component in addition to the line-of-sight (LoS), even if the position of corresponding incidence point (IP) is a priori unknown. Subsequently, we pose a maximum likelihood (ML) estimation problem, to jointly estimate the 3D position and 3D orientation of the UE as well as several nuisance parameters (the UE clock offset and the positions of IPs corresponding to the multipath). The ML problem is a high-dimensional non-convex optimization problem over a product of Euclidean and non-Euclidean manifolds. To avoid complex exhaustive search procedures, we propose a geometric initial estimate of all parameters, which reduces the problem to a 1-dimensional search over a finite interval. Numerical results show the efficiency of the proposed ad-hoc estimation, whose gap to the Cram\'er-Rao bound (CRB) is tightened using the ML estimation.
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- 2022
6. 3D Orientation Estimation with Multiple 5G mmWave Base Stations
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Nazari, Mohammad A., Seco-Granados, Gonzalo, Johannisson, Pontus, and Wymeersch, Henk
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Electrical Engineering and Systems Science - Signal Processing ,Computer Science - Information Theory - Abstract
We consider the problem of estimating the 3D orientation of a user, using the downlink mmWave signals received from multiple base stations. We show that the received signals from several base stations, having known positions, can be used to estimate the unknown orientation of the user. We formulate the estimation problem as a maximum likelihood estimation problem in the the manifold of rotation matrices. In order to provide an initial estimate to solve the non-linear non-convex optimization problem, we resort to a least squares estimation problem that exploits the underlying geometry. Our numerical results show that the problem of orientation estimation can be solved when the signals from at least two base stations are received. We also provide the orientation lower error bound, showing a narrow gap between the performance of the proposed estimators and the bound.
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- 2021
7. Environmental Service-Learning Approach in Higher Education -- A Descriptive Case Study on Student-Led Life Cycle Assessments of University Cafeteria Meals
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Johannisson, Jonas and Hiete, Michael
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Purpose: This study aims to share experiences of an easy to adapt service-learning approach in a graduate course on life cycle assessment (LCA). Specifically, it reports on how students helped the university's cafeteria to assess meals by conducting an LCA for 25 meals and identifying environmental hotspots. Design/methodology/approach: A descriptive case study of a graduate course at Ulm University is presented. The course included lectures and problem-based exercises, both theoretical and software assisted. A course evaluation was conducted during the course and one year after completion to poll improvement potentials, as well as its impacts on students' everyday life. Findings: It was found that although it was the first LCA for all students, the resulting LCA information of 25 different meals were homogeneous, comparable to the scientific literature and beneficial to the cafeteria's sustainable development strategy. The concept of service-learning had a higher impact on students' motivation than a good grade and active-learning is explicitly requested by students. The course design sensitized students to the real-life problems of LCA and made their consumption patterns more elaborate and ecological. Furthermore, this digitization of higher education could be carried out with only minor changes in the present COVID-19 pandemic situation. Originality/value: As the subject of service-learning in natural sciences is still expandable, this study presents an easy to adapt case study on how to integrate such an approach into university curricula dominated by traditional learning. To the best of the authors' knowledge, this case study presents the first published LCA university course explicitly describing and evaluating a service-learning approach. The topic touches the everyday lives of students, allows comparisons between different student groups, is easily scalable to different group sizes and credits, and supports learning both how to study in small groups and cooperation between groups to ensure comparability of LCA results.
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- 2021
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8. Synthesis and Use of Ethyl 6-Acetyloxyhexanoate as an Internal Standard: An Interdisciplinary Experiment for an Undergraduate Chemistry Laboratory
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Parish-Virtue, Katie, Johannisson-Wallman, Mikael, Pilkington, Lisa I., Hsieh, Sally, Barker, David, and Fedrizzi, Bruno
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The combination of organic synthesis and analytical chemistry into a related laboratory experiment is an excellent demonstration of the utility of making a compound to then be used further. Herein we describe an undergraduate laboratory experiment that involves the straightforward synthesis of an internal standard, ethyl 6-acetyloxyhexanoate, for the quantification of various aroma compounds in juice through GC-FID analysis. In addition to the organic synthetic procedures of undertaking a reaction under reflux, separation, and extraction protocols followed by determining the purity of a synthesized compound, this experiment also facilitates the teaching of making standard solutions, using solid phase extraction, preparing samples, and performing and interpreting the results of GC-FID analysis.
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- 2020
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9. Geometrical nonlinearities and shape effects in electromechanical models of piezoelectric bridge structures
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Ohlsson, Fredrik, Johannisson, Pontus, and Rusu, Cristina
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- 2021
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10. Exploring the photocatalytic total oxidation of methane through the lens of a prospective LCA
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Jonas Johannisson and Michael Hiete
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Methane mitigation ,Life cycle assessment (LCA) ,Photocatalysis ,Atmospheric methane removal ,Scenario modelling ,Climate change mitigation ,Environmental pollution ,TD172-193.5 ,Meteorology. Climatology ,QC851-999 - Abstract
Hundreds of megatons of the second most important greenhouse gas (GHG), methane, are released annually to the atmosphere, often from emission sources which are difficult to abate. Research on post-emission mitigation technology is scarce and still in its infancy. This paper proposes a self-sufficient photocatalytic system to mitigate atmospheric methane via total oxidation to CO2 and analyzes its future viability and feasibility using environmental as well as physicochemical metrics. A four-step, explorative, scaled-up, prospective life cycle assessment (LCA) for the year 2050 shows that, in the best-case scenario, the market-ready photocatalytic module will amortize the produced GHG emissions in 1.5 years, while under more conservative assumptions, the physicochemical properties hinder a climate reasonable implementation. Targets like photocatalytic turnover numbers as well as reaction rates are calculated and compared to values reported in the literature to enable goal-oriented research and development. It is shown that more R&D is needed to have the proposed photocatalyst ready by 2050. The importance of methane mitigation development is highlighted and avenues for doing so are presented.
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- 2022
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11. Improved Lower Bounds on Mutual Information Accounting for Nonlinear Signal-Noise Interaction
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Irukulapati, Naga V., Secondini, Marco, Agrell, Erik, Johannisson, Pontus, and Wymeersch, Henk
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Computer Science - Information Theory ,Physics - Optics - Abstract
In fiber-optic communications, evaluation of mutual information (MI) is still an open issue due to the unavailability of an exact and mathematically tractable channel model. Traditionally, lower bounds on MI are computed by approximating the (original) channel with an auxiliary forward channel. In this paper, lower bounds are computed using an auxiliary backward channel, which has not been previously considered in the context of fiber-optic communications. Distributions obtained through two variations of the stochastic digital backpropagation (SDBP) algorithm are used as auxiliary backward channels and these bounds are compared with bounds obtained through the conventional digital backpropagation (DBP). Through simulations, higher information rates were achieved with SDBP, {which can be explained by the ability of SDBP to account for nonlinear signal--noise interactions, Comment: 8 pages, 5 figures, accepted for publication in Journal of Lightwave Technology
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- 2016
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12. Modulation Format Independent Joint Polarization and Phase Tracking for Coherent Receivers
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Czegledi, Cristian B., Agrell, Erik, Karlsson, Magnus, and Johannisson, Pontus
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Computer Science - Information Theory ,Physics - Optics - Abstract
The state of polarization and the carrier phase drift dynamically during transmission in a random fashion in coherent optical fiber communications. The typical digital signal processing solution to mitigate these impairments consists of two separate blocks that track each phenomenon independently. Such algorithms have been developed without taking into account mathematical models describing the impairments. We study a blind, model-based tracking algorithm to compensate for these impairments. The algorithm dynamically recovers the carrier phase and state of polarization jointly for an arbitrary modulation format. Simulation results show the effectiveness of the proposed algorithm, having a fast convergence rate and an excellent tolerance to phase noise and dynamic drift of the polarization. The computational complexity of the algorithm is lower compared to state-of-the-art algorithms at similar or better performance, which makes it a strong candidate for future optical systems.
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- 2016
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13. Mapping research on the social impact of the arts: what characterises the field? [version 2; peer review: 2 approved]
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Cia Gustrén, Sofia Lindström Sol, Johan Eklund, Gustaf Nelhans, Roger Blomgren, and Jenny Johannisson
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artistic intervention ,effects of culture ,bibliometric analysis ,cultural policy ,arts and culture ,eng ,Science ,Social Sciences - Abstract
This article explores the broad and undefined research field of the social impact of the arts. The effects of art and culture are often used as justification for public funding, but the research on these interventions and their effects is unclear. Using a co-word analysis of over 10,000 articles published between 1990 and 2020, we examined the characteristics of the field as we have operationalised it through our searches. We found that since 2015 this research field has expanded and consists of different epistemologies and methodologies, summarised in largely overlapping subfields belonging to the social sciences, humanities, arts education, and arts and health/therapy. In formal or informal learning settings, studies of theatre/drama as an intervention to enhance skills, well-being, or knowledge among children are most common in our corpus. A study of the research front through the bibliographic coupling of the most cited articles in the corpus confirmed the co-word analysis and revealed new themes that together form the ground for insight into research on the social impact of the arts. This article can therefore inform discussions on the social value of culture and the arts.
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- 2022
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14. Cryopreservation of dog semen in a Tris extender with two different 1% soybean preparations compared with a Tris egg yolk extender
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Ulrika Hermansson, Anders Johannisson, and Eva Axnér
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canine ,extender ,reproduction ,reproductive tract ,semen freezing ,soybean lecithin ,Veterinary medicine ,SF600-1100 - Abstract
Abstract Egg yolk is widely used as a cryoprotectant in dog semen extenders, but there is a risk of contamination with animal pathogens. In addition, egg yolk may vary in composition, making it difficult to standardize the extender. Lecithin is an animal protein‐free alternative to egg yolk for semen cryopreservation. Recently, it was shown that 1% of soybean lecithin type II‐S was better than 2% for freezing canine semen. The aim of the study was to compare two different types of soybean lecithin, with egg yolk as a control. Ejaculates from eight dogs were divided into three equal parts and diluted with a Tris‐based extender, containing either 20% egg yolk, 1% soybean lecithin Type II‐S or 1% soybean lecithin Type IV‐S. The samples were then frozen. Sperm motility was evaluated by computer‐assisted sperm analysis (CASA), acrosome integrity (FITC‐PNA/PI) and sperm membrane integrity (SYBR‐14/PI) post‐thaw, as well as after 2 and 4 hr incubation at 37°C. Post‐thaw sperm chromatin structure assay and plasma membrane integrity were evaluated by flow cytometry. Total motility, sperm plasma membrane integrity and acrosome integrity were significantly better in the egg yolk extender than in the two soybean lecithin‐based extenders. Individual motility post‐thaw differed more than in the fresh samples, illustrating individual differences in tolerance to the cryostress. The DNA Fragmentation Index (% DFI) was significantly lower in the Tris egg yolk (TEY) extender compared to any of the soybean‐based extenders. The number of high green stained spermatozoa were significantly higher in Type IV‐S compared to the control TEY extender. In conclusion, egg yolk was superior to the two lecithin‐based extenders to cryopreserve canine semen.
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- 2021
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15. Polarization Drift Channel Model for Coherent Fibre-Optic Systems
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Czegledi, Cristian B., Karlsson, Magnus, Agrell, Erik, and Johannisson, Pontus
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Physics - Optics ,Computer Science - Information Theory - Abstract
A theoretical framework is introduced to model the dynamical changes of the state of polarization during transmission in coherent fibre-optic systems. The model generalizes the one-dimensional phase noise random walk to higher dimensions, accounting for random polarization drifts, emulating a random walk on the Poincar\'e sphere, which has been successfully verified using experimental data. The model is described in the Jones, Stokes and real four-dimensional formalisms, and the mapping between them is derived. Such a model will be increasingly important in simulating and optimizing future systems, where polarization-multiplexed transmission and sophisticated digital signal processing will be natural parts. The proposed polarization drift model is the first of its kind as prior work either models polarization drift as a deterministic process or focuses on polarization-mode dispersion in systems where the state of polarization does not affect the receiver performance. We expect the model to be useful in a wide-range of photonics applications where stochastic polarization fluctuation is an issue., Comment: 15 pages, 4 figures
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- 2015
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16. Stochastic Digital Backpropagation with Residual Memory Compensation
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Irukulapati, Naga V., Marsella, Domenico, Johannisson, Pontus, Agrell, Erik, Secondini, Marco, and Wymeersch, Henk
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Computer Science - Information Theory ,Physics - Optics - Abstract
Stochastic digital backpropagation (SDBP) is an extension of digital backpropagation (DBP) and is based on the maximum a posteriori principle. SDBP takes into account noise from the optical amplifiers in addition to handling deterministic linear and nonlinear impairments. The decisions in SDBP are taken on a symbol-by-symbol (SBS) basis, ignoring any residual memory, which may be present due to non-optimal processing in SDBP. In this paper, we extend SDBP to account for memory between symbols. In particular, two different methods are proposed: a Viterbi algorithm (VA) and a decision directed approach. Symbol error rate (SER) for memory-based SDBP is significantly lower than the previously proposed SBS-SDBP. For inline dispersion-managed links, the VA-SDBP has up to 10 and 14 times lower SER than DBP for QPSK and 16-QAM, respectively., Comment: 7 pages, accepted to publication in 'Journal of Lightwave Technology (JLT)'
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- 2015
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17. Definition and Quantification of Shock/Peak/Transient Vibration
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Hans Lindell, Pontus Johannisson, and Snævar Leó Grétarsson
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high frequency ,HAVS ,VPM ,VSI ,VSL ,transient ,General Works - Abstract
Vibration injury in the hand–arm system from hand-held machines is one of the most common occupational health injuries. Machines emitting high-frequency shock vibrations, e.g., impact wrenches have since long been identified as a special risk factor. In legislative and standard texts, the terms shock, impact, peak and transient vibration are frequently used to underline the special risks associated with these kinds of vibrations. Despite this fact, in the literature there is not a mathematically stringent definition of either shock vibration or how the amplitude of the shock is defined. In this study, we suggest algorithms for definition and quantification of these terms and apply them to machine vibrations of various kinds.
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- 2023
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18. Effect of Some Plant-Based Substances on Microbial Content and Sperm Quality Parameters of Bull Semen
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Aleksandar Cojkic, Ingrid Hansson, Anders Johannisson, and Jane M. Morrell
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bull semen ,pomegranate ,ginger ,curcumin ,antibacterial effect ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
The rapid emergence of antibacterial resistance requires alternatives to antibiotics to be found, including for semen preservation. One of the possible alternatives would be to use plant-based substances with known antimicrobial effects. The objective of this study was to test the antimicrobial effect of pomegranate powder, ginger, and curcumin extract in two concentrations on bull semen microbiota after exposure for
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- 2023
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19. A Low-Complexity Detector for Memoryless Polarization-Multiplexed Fiber-Optical Channels
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Häger, Christian, Beygi, Lotfollah, Agrell, Erik, Johannisson, Pontus, Karlsson, Magnus, and Amat, Alexandre Graell i
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Computer Science - Information Theory - Abstract
A low-complexity detector is introduced for polarization-multiplexed M-ary phase shift keying modulation in a fiber-optical channel impaired by nonlinear phase noise, generalizing a previous result by Lau and Kahn for single-polarization signals. The proposed detector uses phase compensation based on both received signal amplitudes in conjunction with simple straight-line rather than four-dimensional maximum-likelihood decision boundaries., Comment: accepted for publication in IEEE Comm. Lett
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- 2013
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20. Effects of season and single layer centrifugation on bull sperm quality in Thailand
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Thanapol Nongbua, Apirak Utta, Nutthee Am-in, Junpen Suwimonteerabutr, Anders Johannisson, and Jane M Morrell
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temperature ,humidity ,bovine semen quality ,colloid centrifugation ,frozen semen ,Animal culture ,SF1-1100 ,Animal biochemistry ,QP501-801 - Abstract
Objective The aim of study was to investigate the effects of season and single layer centrifugation (SLC) before cryopreservation on post-thaw bull sperm quality in Thailand. Methods Semen was collected from 6 bulls (Bos indicus) in summer, rainy season and winter 2014 through 2016. Semen characteristics, sperm morphology, sperm kinematics, viability, chromatin structure and mitochondrial membrane were evaluated. Meteorological data were available from the local meteorological station; Results Season had an effect on semen characteristics in the raw ejaculate, with higher proportions of normal spermatozoa and lower abnormalities in winter than in the other two seasons. Sperm kinematics, viability, DNA fragmentation index, and mitochondrial membrane potential were not different between seasons. Sperm samples selected by SLC had greater normal morphology and a lower proportion with bent tails than controls and higher values of progressive motility (PRO), beat cross frequency, linearity, straightness, wobble (WOB), and lower values of slow motility, velocity average path (VAP), velocity curved line, and amplitude of lateral head displacement than controls. In addition, SLC-selection had a favorable effect on PRO, VAP, and WOB that differed among seasons. Conclusion Our results suggested that these bulls were well adapted to their location, with season having an effect on sperm morphology. Moreover, SLC could be used prior to cryopreservation, regardless of season, to enhance normal morphology and kinematics of bull sperm samples without adversely affecting other parameters of sperm quality. However, there was considerable variation among bulls in DNA fragmentation index, mitochondrial membrane potential and sperm viability. In addition, SLC had a positive effect on sperm morphology and sperm kinematics, which could be expected to influence fertility.
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- 2020
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21. Effects of cashew gum and nanoparticles on cooled stallion semen
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Kahynna Cavalcante Loureiro, Isabel Bezerra Lima-Verde, Anders Johannisson, Theodoros Ntallaris, Alessandro Jager, Petr Štěpánek, Marcelo da Costa Mendonça, Patrícia Severino, and Jane M. Morrell
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Cashew gum ,Cooling ,Nanoparticles ,Semen ,Stallion ,Veterinary medicine ,SF600-1100 - Abstract
Abstract Background Cryopreservation of stallion spermatozoa tends to cause plasma membrane damage due to the low ratio of cholesterol to phospholipids. Gums have been suggested as an alternative cryoprotectant to glycerol for stallion spermatozoa. Therefore, the present experiment was designed to verify whether the effect of addition of cashew gum (CG), or nanoparticles (NP) containing CG, to the extender before cooling on sperm quality in stallion semen. Ejaculates from 6 stallions were extended and split between six treatment groups (control, a-tocopherol [TOC], CG1, CG0.5, NP1 and NP0.5), stored in cryotubes at 4 °C. Results Aliquots were analysed by computer-assisted sperm motility analysis on the day of collection, and after 24 h and 48 h of cold storage. After 48 h, the total motility with NP1 (78.53 + 6.31%) was similar to control 85.79 + 6.31% at 0 h. The same pattern was observed for progressive motility. Membrane integrity assessed by flow cytometer was similar between control, TOC and G1 at all storage times. The DNA fragmentation in the control group increased at all time points, whereas chromatin integrity was maintained after 24 h in TOC and NP0.5 compared to 0 h. There was no increase in the proportion of live spermatozoa producing hydrogen peroxide, but there was a tendency for an increased proportion of spermatozoa in the live superoxide category in CG1 after 24 h cooled storage. Conclusions The addition of CG or CG-derived NP to extender for stallion semen was not harmful to the sperm cells.
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- 2020
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22. Season does not have a deleterious effect on proportions of stallion seminal plasma proteins
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Anders JOHANNISSON, Essraa M. AL-ESSAWE, Anas Kh. AL-SAFFAR, Saeid KARKEHABADI, Isabel LIMA-VERDE, Manuela WULF, Christine AURICH, and Jane M. MORRELL
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chromatography ,cytometry ,protein fractions ,seasonal changes ,stallion ,Reproduction ,QH471-489 ,Internal medicine ,RC31-1245 - Abstract
The mechanism by which the content of the major groups of seminal plasma proteins in stallion semen changes between the breeding and non-breeding seasons remains unknown. Here, we investigated the proportions of non-heparin-binding, phosphorylcholine-binding, and heparin-binding proteins in seminal plasma with the aim of relating them to sperm quality and testosterone levels in good and bad freezer stallions. Only minor variations in the major protein groups were found between the breeding and non-breeding seasons. In the non-breeding season, a higher content of a subset of non-heparin binding proteins as well as of heparin-binding proteins was found. Analysis of semen characteristics revealed a somewhat contrasting picture. While only minor variations in sperm kinematics and sperm morphology were found between seasons, the flow-cytometric measurements of mitochondrial membrane potential and also, to some extent, reactive oxygen species production indicated lower sperm quality in the breeding season. Chromatin integrity and testosterone levels were unchanged between seasons. The results suggest that stallion ejaculates could be used year-round for freezing, since only minor differences in protein composition exist between the breeding and non-breeding seasons, as well as between good and bad freezers. In addition, sperm quality is not impaired during the non-breeding season.
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- 2020
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23. Variation in length of alpha waves reveals how forebrain activity is organized
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Tomas Johannisson
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wavelength ,patterns ,functional organization ,rep ,Science - Abstract
Background The cerebral cortex is composed of functional units known as columns. The “two levels” hypothesis states that the activity in a column is either at a high level or at a normal, relatively low level. Measurements indicate that the duration of the high activity in a column is around 450 ms. The number of highly active columns is often 4–5. These data are from previous studies on alpha waves in electroencephalograms. The idea is that alpha waves are created when a regulating system keeps the number of highly active columns within proper limits. If this is true, then regulating signals determines the length of the alpha waves, which opens up for a possibility to test the hypothesis.Methods and results Wavelengths were measured in sequences of alpha waves, and distinctive patterns in the wavelength variation were found. The elements of these patterns were repeated at intervals that exactly matched the predicted duration of high activity in individual columns.Conclusions The discovery of patterns in the wavelength variation confirms the central part of the two levels hypothesis. The patterns reveal the actual number of highly active columns. Moreover, the duration of high activity in a column can be measured. Number and duration outside the optimal ranges may lead to a variety of symptoms.
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- 2020
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24. DNA methylation patterns vary in boar sperm cells with different levels of DNA fragmentation
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Abdolrahman Khezri, Birgitte Narud, Else-Berit Stenseth, Anders Johannisson, Frøydis Deinboll Myromslien, Ann Helen Gaustad, Robert C. Wilson, Robert Lyle, Jane M. Morrell, Elisabeth Kommisrud, and Rafi Ahmad
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Boar ,Sperm ,DNA-methylation ,DNA-integrity ,Epigenetics ,RRBS ,Biotechnology ,TP248.13-248.65 ,Genetics ,QH426-470 - Abstract
Abstract Background Sperm DNA integrity is considered essential for successful transmission of the paternal genome, fertilization and normal embryo development. DNA fragmentation index (DFI, %) has become a key parameter in the swine artificial insemination industry to assess sperm DNA integrity. Recently, in some elite Norwegian Landrace boars (boars with excellent field fertility records), a higher level of sperm DFI has been observed. In order to obtain a better understanding of this, and to study the complexity of sperm DNA integrity, liquid preserved semen samples from elite boars with contrasting DFI levels were examined for protamine deficiency, thiol profile and disulphide bonds. Additionally, the DNA methylation profiles of the samples were determined by reduced representation bisulphite sequencing (RRBS). Results In this study, different traits related to sperm DNA integrity were investigated (n = 18 ejaculates). Upon liquid storage, the levels of total thiols and disulphide bonds decreased significantly, while the DFI and protamine deficiency level increased significantly. The RRBS results revealed similar global patterns of low methylation from semen samples with different levels of DFI (low, medium and high). Differential methylation analyses indicated that the number of differentially methylated cytosines (DMCs) increased in the low-high compared to the low-medium and the medium-high DFI groups. Annotating the DMCs with gene and CpG features revealed clear differences between DFI groups. In addition, the number of annotated transcription starting sites (TSS) and associated pathways in the low-high comparison was greater than the other two groups. Pathway analysis showed that genes (based on the closest TSS to DMCs) corresponding to low-high DFI comparison were associated with important processes such as membrane function, metabolic cascade and antioxidant defence system. Conclusion To our knowledge, this is the first study evaluating DNA methylation in boar sperm cells with different levels of DFI. The present study shows that sperm cells with varying levels of DNA fragmentation exhibit similar global methylation, but different site-specific DNA methylation signatures. Moreover, with increasing DNA fragmentation in spermatozoa, there is an increase in the number of potentially affected downstream genes and their respective regulatory pathways.
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- 2019
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25. Modeling of Nonlinear Signal Distortion in Fiber-Optical Networks
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Johannisson, Pontus and Agrell, Erik
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Physics - Optics - Abstract
A low-complexity model for signal quality prediction in a nonlinear fiber-optical network is developed. The model, which builds on the Gaussian noise model, takes into account the signal degradation caused by a combination of chromatic dispersion, nonlinear signal distortion, and amplifier noise. The center frequencies, bandwidths, and transmit powers can be chosen independently for each channel, which makes the model suitable for analysis and optimization of resource allocation, routing, and scheduling in large-scale optical networks applying flexible-grid wavelength-division multiplexing.
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- 2013
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26. Sperm Quality in Young Bull Semen Can Be Improved by Single Layer Centrifugation
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Isabel Lima-Verde, Emma Hurri, Theodoros Ntallaris, Anders Johannisson, Hans Stålhammar, and Jane M. Morrell
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sperm quality ,young bull ejaculates ,genomic selection ,genetic progress ,generation interval ,single-layer centrifugation ,Veterinary medicine ,SF600-1100 ,Zoology ,QL1-991 - Abstract
Interest in using semen from young bulls is increasing due to identifying promising animals by genomic selection. However, sperm quality in these ejaculates may not reach currently accepted standards for the cattle breeding industry. The purpose of this study was to determine if centrifugation of semen from young bulls through the Bovicoll colloid could improve sperm quality sufficiently for the frozen semen to be acceptable for artificial insemination. Ejaculates from 19 young bulls were split and either processed by Single-Layer Centrifugation (SLC) or not (CON) before freezing. After thawing, sperm quality was evaluated by determination of membrane integrity, mitochondrial membrane potential, DNA integrity, production of reactive oxygen species, sperm morphology and motility. Approximately half of the CON samples reached acceptable post-thaw quality (membrane integrity ≥ 40%) despite being below the breeding company´s desired sperm concentration threshold pre-freezing. In the remaining samples, sperm quality was improved by SLC such that 45% of them reached acceptable quality post-thaw. Almost 75% of the young bull sperm samples could have produced usable frozen semen doses by adjusting the breeding company´s current processing protocols. Since lowering the generation interval has a direct effect on the genetic gain per year, SLC could aid genetic progress in cattle breeding.
- Published
- 2022
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27. Analytical Modeling of Nonlinear Propagation in a Strongly Dispersive Optical Communication System
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Johannisson, Pontus
- Subjects
Physics - Optics - Abstract
Recently an analytical model was presented that treats the nonlinear signal distortion from the Kerr nonlinearity in optical transmission systems as additive white Gaussian noise. This important model predicts the impact of the Kerr nonlinearity in systems operating at a high symbol rate and where the accumulated dispersion at the receiver is large. Starting from the suggested model for the propagating signal, we here give an independent and different calculation of the main result. The analysis is based on the Manakov equation with attenuation included and a complete and detailed derivation is given using a perturbation analysis. As in the case with the published model, in addition to assuming that the input signal can be written on a specific form, two further assumptions are necessary; the nonlinearity is weak and the signal-noise interaction is neglected. The result is then found without any further approximations., Comment: Results are unchanged, but the relation to the results in Ref. [4] is made clear
- Published
- 2012
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28. A Structural Battery and its Multifunctional Performance
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Leif E. Asp, Karl Bouton, David Carlstedt, Shanghong Duan, Ross Harnden, Wilhelm Johannisson, Marcus Johansen, Mats K. G. Johansson, Göran Lindbergh, Fang Liu, Kevin Peuvot, Lynn M. Schneider, Johanna Xu, and Dan Zenkert
- Subjects
biomimetics ,carbon fiber composites ,fibrous materials ,lithium-ion batteries ,multifunctional materials ,self-sustaining materials ,Environmental technology. Sanitary engineering ,TD1-1066 ,Renewable energy sources ,TJ807-830 - Abstract
Engineering materials that can store electrical energy in structural load paths can revolutionize lightweight design across transport modes. Stiff and strong batteries that use solid‐state electrolytes and resilient electrodes and separators are generally lacking. Herein, a structural battery composite with unprecedented multifunctional performance is demonstrated, featuring an energy density of 24 Wh kg−1 and an elastic modulus of 25 GPa and tensile strength exceeding 300 MPa. The structural battery is made from multifunctional constituents, where reinforcing carbon fibers (CFs) act as electrode and current collector. A structural electrolyte is used for load transfer and ion transport and a glass fiber fabric separates the CF electrode from an aluminum foil‐supported lithium–iron–phosphate positive electrode. Equipped with these materials, lighter electrical cars, aircraft, and consumer goods can be pursued.
- Published
- 2021
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29. Nonlocal effects in high energy charged particle beams
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Johannisson, Pontus, Anderson, Dan, Lisak, Mietek, Marklund, Mattias, Fedele, Renato, and Kim, Arkadi
- Subjects
High Energy Physics - Phenomenology ,Physics - Accelerator Physics - Abstract
Within the framework of the thermal wave model, an investigation is made of the longitudinal dynamics of high energy charged particle beams. The model includes the self-consistent interaction between the beam and its surroundings in terms of a nonlinear coupling impedance, and when resistive as well as reactive parts are included, the evolution equation becomes a generalised nonlinear Schroedinger equation including a nonlocal nonlinear term. The consequences of the resistive part on the propagation of particle bunches are examined using analytical as well as numerical methods., Comment: 6 pages, 6 figures, uses RevTeX4
- Published
- 2003
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30. Influence of Single Layer Centrifugation with Canicoll on Semen Freezability in Dogs
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Guillaume Domain, Hiba Ali Hassan, Eline Wydooghe, Osvaldo Bogado Pascottini, Anders Johannisson, Jane M. Morrell, Wojciech Niżański, and Ann Van Soom
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canine ,fertility ,semen selection ,cryopreservation ,semen quality ,Veterinary medicine ,SF600-1100 ,Zoology ,QL1-991 - Abstract
This study evaluated how semen selection by single layer centrifugation (SLC) with Canicoll affects semen freezability in dogs. A total of eighteen ejaculates, collected from dogs with optimal and suboptimal semen quality (optimal: normal morphology (NM) ≥ 80%, n = 9; suboptimal: NM between 60 and 79%, n = 9), were divided into two aliquots and subjected to standard centrifugation or SLC before cryopreservation. Motility, NM, membrane integrity, mitochondrial membrane potential (MMP), and DNA integrity were improved in fresh samples after SLC, regardless of semen quality, but at the expense of some good quality spermatozoa. After thawing, NM and membrane integrity were improved in SLC-selected semen in both semen qualities. Interestingly, MMP was also higher but only in optimal quality semen. Still, spermatozoa from suboptimal quality semen did not survive freezing to the same extent as spermatozoa from optimal quality semen, even after selecting superior spermatozoa. Semen selection with Canicoll is, therefore, an effective technique to isolate a subpopulation of high-quality spermatozoa and obtain sperm samples of better quality after thawing, but is not sufficient to improve the intrinsic inferior freezability of suboptimal quality semen. So far, eighteen pups were born after insemination with SLC-selected frozen-thawed semen, proving that these selected spermatozoa remain fertile.
- Published
- 2022
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31. Nonlinear Bessel beams
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Johannisson, Pontus, Anderson, Dan, Lisak, Mietek, and Marklund, Mattias
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Physics - Optics - Abstract
The effect of the Kerr nonlinearity on linear non-diffractive Bessel beams is investigated analytically and numerically using the nonlinear Schr\"odinger equation. The nonlinearity is shown to primarily affect the central parts of the Bessel beam, giving rise to radial compression or decompression depending on whether the nonlinearity is focusing or defocusing, respectively. The dynamical properties of Gaussian-truncated Bessel beams are also analysed in the presence of a Kerr nonlinearity. It is found that although a condition for width balance in the root-mean-square sense exists, the beam profile becomes strongly deformed during propagation and may exhibit the phenomena of global and partial collapse., Comment: 15 pages, 7 figures
- Published
- 2003
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32. Practical Method for Freezing Buck Semen
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Jane M. Morrell, Pongpreecha Malaluang, Theodoros Ntallaris, and Anders Johannisson
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goat sperm cryopreservation ,removal of seminal plasma ,soy lecithin semen extender ,plasma membrane integrity ,chromatin integrity ,Veterinary medicine ,SF600-1100 ,Zoology ,QL1-991 - Abstract
Although several protocols for cryopreserving buck semen are described in the literature, they differ widely in factors such as season and method of semen collection, extender and sperm concentration. Therefore, choosing a protocol that is suitable for a particular on-farm situation can be problematic. In the present study, semen was collected by artificial vagina from seven bucks on a farm located approximately 90 minutes’ drive away from the laboratory, about 6 weeks before the start of the goat breeding season. The semen was immediately extended in warm semen extender containing soy lecithin and was placed in an insulated box with a cold pack for up to 4 h, during semen collection from the remaining bucks and subsequent transport to the laboratory. Following centrifugation at 4 °C and resuspension in the soy lecithin extender to a sperm concentration of 800 × 106 spermatozoa/mL, 0.25 mL plastic straws were filled and frozen in racks 4 cm above the surface of liquid nitrogen. This simple protocol resulted in an acceptable post-thaw quality for all seven bucks, with a mean post-thaw motility of 55 ± 21% and mean fragmented chromatin of 3.27 ± 1.39%. Normal sperm morphology was >90% in all ejaculates. The semen was sent to a gamete bank for long-term storage.
- Published
- 2022
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33. Light bullets and optical collapse in vacuum
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Brodin, G., Stenflo, L., Anderson, D., Lisak, M., Marklund, M., and Johannisson, P.
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Physics - Optics ,High Energy Physics - Theory ,Physics - General Physics - Abstract
In quantum electrodynamics, photon--photon scattering can be the result of the exchange of virtual electron--positron pairs. Effectively, this gives rise to self-interaction terms in Maxwell's equations, similar to the nonlinearities due to polarization in nonlinear optics. These self-interaction terms vanish in the limit of parallel propagating waves. However if the modes generated in bounded regions are used, there will be a non-zero total effect. We show that stationary two-dimensional light bullets can form in guiding structures, due to the balancing effect of quantum electrodynamical vacuum nonlinearities on dispersion and diffraction. These light bullets are unstable and exhibit the possibility of self-focusing collapse. The consequences of our results are also discussed., Comment: 7 pages, to appear in Phys. Lett. A
- Published
- 2002
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34. Sperm quality in frozen beef and dairy bull semen
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Jane Margaret Morrell, Andra Sabina Valeanu, Nils Lundeheim, and Anders Johannisson
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Chromatin integrity ,Membrane integrity ,Mitochondrial membrane potential ,Motility ,Reactive oxygen species ,Veterinary medicine ,SF600-1100 - Abstract
Abstract Background There is speculation that beef bull semen quality is inferior to that of dairy bulls although few scientific studies are available in the literature. The aim of this study was to evaluate sperm quality in beef bull semen and to determine which parameters could be indicative of fertility after insemination. Sperm quality, assessed by computer assisted sperm motility analysis and flow cytometric evaluation of membrane integrity, levels of reactive oxygen species, mitochondrial membrane potential, acrosome status and DNA fragmentation index, was evaluated in beef and dairy bull semen. Results For beef bulls, normal morphology (r = 0.62, P
- Published
- 2018
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- View/download PDF
35. Filter Implementation for Power-Efficient Chromatic Dispersion Compensation
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Christoffer Fougstedt, Alireza Sheikh, Pontus Johannisson, and Per Larsson-Edefors
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Optical fiber communication ,digital signal processing ,application specific integrated circuits ,chromatic dispersion ,Applied optics. Photonics ,TA1501-1820 ,Optics. Light ,QC350-467 - Abstract
Chromatic dispersion (CD) compensation in coherent fiber-optic systems represents a very significant DSP block in terms of power dissipation. Since spectrally efficient coherent systems are expected to find a wider deployment in systems shorter than long haul, it becomes relevant to investigate filter implementation aspects of CD compensation in the context of systems with low-to-moderate amounts of accumulated dispersion. The investigation we perform in this paper has an emphasis on implementation aspects such as power dissipation and area usage, it deals with both time-domain and frequency-domain CD compensations, and it considers both A/D-conversion quantization and fixed-point filter design aspects. To enable an accurate analysis on power dissipation and chip area, the evaluated filters are implemented in a 28-nm fully depleted silicon-on-insulator (FD-SOI) process technology. We show that an optimization of the filter response that takes pulse shaping into account can significantly reduce power dissipation and area usage of time-domain implementations, making them a viable alternative to frequency-domain implementations.
- Published
- 2018
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- View/download PDF
36. Effects of cashew gum and nanoparticles on cooled stallion semen
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Loureiro, Kahynna Cavalcante, Lima-Verde, Isabel Bezerra, Johannisson, Anders, Ntallaris, Theodoros, Jager, Alessandro, Štěpánek, Petr, da Costa Mendonça, Marcelo, Severino, Patrícia, and Morrell, Jane M.
- Published
- 2020
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37. DNA methylation patterns vary in boar sperm cells with different levels of DNA fragmentation
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Khezri, Abdolrahman, Narud, Birgitte, Stenseth, Else-Berit, Johannisson, Anders, Myromslien, Frøydis Deinboll, Gaustad, Ann Helen, Wilson, Robert C., Lyle, Robert, Morrell, Jane M., Kommisrud, Elisabeth, and Ahmad, Rafi
- Published
- 2019
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38. Cambios en los niveles sanguíneos de vitaminas A y E, selenio, leucocitos y expresión de moléculas de BR adhesión para migración en neutrófilos en vacas lecheras alrededor del parto
- Author
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Guillermo Esteban Meglia, Anders Johannisson, L Petersson, and Karin Persson Waller
- Subjects
vacas lecheras ,inmunidad ,leucocitos ,vitaminas ,Veterinary medicine ,SF600-1100 - Abstract
Blood samples from ten Swedish dairy cows were taken one month before calving, at calving, and one month after calving. The blood concentration of vitamins A and E, and the trace element selenium (Se) were analysed, as well as the total and differential white blood cell counts,a nd the presenceo f CD62L and CD18 adhesionm oleculeso n blood neutrophils. The levels of vitamins A and E decreased significantly at calving, while whole blood Se increased Leukocytosisw as detectedat calving, explainedm ainly by neutrophilia.T he number of lymphocytest endedt o decreasea t calvrng.T he proportion of CD62L- neutrophilsd ecreased sisnlficantlv at this ttme
- Published
- 2017
39. Effect of insemination-related factors on pregnancy rate using sexed semen in Holstein heifers
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J. Kurykin, T. Hallap, M. Jalakas, P. Padrik, T. Kaart, A. Johannisson, and Ü. Jaakma
- Subjects
holstein ,sex-sorted semen ,estrus ,sperm quality ,intracornual insemination ,fertility ,Animal culture ,SF1-1100 - Abstract
The objectives were to determine the effects of insemination with sexed semen at spontaneous and induced estrus, fixed-time insemination at synchronized estrus, the deposition site, estrous intensity, housing, age, body weight, and bull on the pregnancy rate in Holstein heifers, and to compare the quality traits of sexed sperm with those of unsexed semen. The study was conducted on 3206 heifers, housed in three free-stall barns and in four tie-stall facilities. After synchronization by two prostaglandin F2α (PGF2α) treatments 14 days apart, 281 heifers were inseminated conventionally and 118 intracornually with sexed semen, and 532 and 148 heifers, respectively, with unsexed semen 80-82 h after the second treatment. At spontaneous estrus, 1129 heifers were inseminated with sexed and 529 with unsexed semen, and at estrus induced by a single PGF2α treatment 185 heifers were inseminated with sexed and 284 with unsexed semen. Heifers were inseminated conventionally with sexed semen 12 h after detection of estrus, and with unsexed semen according to the a.m.-p.m rule. Sexed and unsexed semen doses from five bulls were evaluated for motility, morphology, membrane integrity, and chromatin stability. Overall pregnancy rate with sexed semen (41.7%) was 80.8% of that with unsexed semen (51.6%) and was lower than with unsexed semen irrespective of the type and intensity of estrus, and deposition site. Insemination at spontaneous estrus resulted in a higher pregnancy rate (53.4%) than at induced (41.9%) or synchronized (44.7%) estrus. Pregnancy rates did not differ after intracornual (44.9%) or conventional insemination (48.4%). Strong estrus resulted in higher pregnancy rate (by 14.4% points) compared to weak estrus. The type of housing, age, and weight of heifers had no effect irrespective of the type of semen. The total, progressive and linear motility, and membrane integrity were lower and proportions of immotile sperm greater, for sexed than for unsexed semen.
- Published
- 2016
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40. A Structured Approach for the Mitigation of Natural Methane Emissions—Lessons Learned from Anthropogenic Emissions
- Author
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Jonas Johannisson and Michael Hiete
- Subjects
natural methane emissions ,mitigation ,CH4 ,climate change ,greenhouse gas ,framework ,Organic chemistry ,QD241-441 - Abstract
Methane is the second most important greenhouse gas. Natural methane emissions represent 35–50% of the global emissions budget. They are identified, measured and categorized, but, in stark contrast to anthropogenic emissions, research on their mitigation is largely absent. To explain this, 18 problems are identified and presented. This includes problems related to the emission characteristics, technological and economic challenges, as well as problems resulting from a missing framework. Consequently, strategies, methods and solutions to solve or circumvent the identified problems are proposed. The framework covers definitions for methane source categorization and for categories of emission types and mitigation approaches. Business cases for methane mitigation are discussed and promising mitigation technologies briefly assessed. The importance to get started with methane mitigation in the different areas is highlighted and avenues for doing so are presented.
- Published
- 2020
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41. Open Access Scholarly Publishing on the Competitive Market: University Management as Obstacle and Enabler
- Author
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Jenny Johannisson
- Subjects
Scholarly publishing ,open access ,university management ,General Works - Abstract
This article explores the relation between university management and open access scholarly publishing in Sweden. Open access is generally promoted in Swedish national research policy, referring to internationally adopted recommendations on free access to knowledge by researchers and citizens alike. In principle, the conditions for universities to not only promote but also actively contribute to open access by hosting open access scholarly journals could therefore be deemed adequate. In reality, however, many universities choose to adapt only to external systems of assessment and disregard internal demands from the research community. Since hosting open access scholarly journals is not favored by existing external systems of assessment, university management that does not also act on internal demands from the research community runs the risk of becoming an obstacle rather than an enabler of open access scholarly publishing.
- Published
- 2015
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42. Sperm quality in frozen beef and dairy bull semen
- Author
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Morrell, Jane Margaret, Valeanu, Andra Sabina, Lundeheim, Nils, and Johannisson, Anders
- Published
- 2018
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43. Naturally and stimulated levels of reactive oxygen species in cooled stallion semen destined for artificial insemination
- Author
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A. Johannisson, A. Lundgren, P. Humblot, and J.M. Morrell
- Subjects
stallion ,artificial insemination ,cooled semen ,reactive oxygen species ,fertility ,Animal culture ,SF1-1100 - Abstract
The decrease in foaling rates after artificial insemination with cooled semen warrants the search for new predictors of fertility. The objectives were to investigate levels of naturally occurring reactive oxygen species (ROS) in cooled, stored stallion semen doses for artificial insemination (AI), and their relationship with parameters of semen quality and with pregnancy rate. Semen was collected from warmblood stallions (n=15) and used to prepare commercial semen doses for AI. Sperm quality was evaluated after cooled transport to the laboratory overnight. The results were correlated with observed foaling and pregnancy rates. Hydroethidine and dichlorodihydrofluorescein diacetate were used as indicators for the ROS superoxide and hydrogen peroxide, respectively. Sperm morphology, motility, plasma membrane integrity and chromatin integrity were also evaluated. These variables were correlated with each other and with pregnancy rates. We found a high inter-individual variation in the ROS levels between stallions. The proportion of live, hydrogen peroxide-negative spermatozoa was correlated with progressive motility, whereas live hydrogen peroxide-negative spermatozoa and chromatin damage were negatively correlated, indicating that low levels of hydrogen peroxide were correlated with good chromatin integrity. The percentage of dead hydrogen peroxide-positive sperm was negatively related to the foaling rate. The negative relationships were stronger when combining results from both assays for ROS. These results for stored semen samples indicate that high individual variation exists for superoxide and hydrogen peroxide measurements, and that ROS status can influence sperm quality. Thus, ROS may be some of the factors influencing fertility. Moreover, combinations of ROS variables improved the correlation with fertility, indicating the usefulness of including these variables in a future model for prediction of the fertility of a semen sample.
- Published
- 2014
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44. The Communication Attitude Test (CAT-S): Normative Values for 220 Swedish Children
- Author
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Johannisson, Tove B., Wennerfeldt, Susanna, Havstam, Christina, Naeslund, Maria, Jacobson, Kajsa, and Lohmander, Anette
- Abstract
Background: The risk of developing a negative attitude to communication as a consequence of having a speech disorder has been in focus for decades in research concerning fluency disorders in relation to both children and adults. The Communication Attitude Test (CAT), which was created to measure children's attitudes towards their own communication, has been widely used. Research has shown that children who stutter have a significantly more negative attitude to their own communication than normal-speaking children and preliminary results show a similar picture in children with other types of speech disorders. However, the setting for obtaining data on normal-speaking children often differs from that on children with speech disorders. In order to make a significant interpretation of results from children with a speech disorder, comparable data on normal-speaking children are needed. Aims: The main purpose of this study was to obtain norm values for the Swedish version of the test (CAT-S) and examine possible differences related to age, sex or small town/big city. A second aim was to investigate some aspects of reliability, such as internal consistency, and validity in terms of item analysis as well as a qualitative analysis of the answers to the different items. In addition, group setting was compared with individual setting for the test procedure. Methods & Procedures: CAT-S was completed in a group setting by 220 normal-speaking children aged 7-15 years and by an additional group of 35 normal-speaking 10-year-old children who completed the test individually. Outcomes & Results: The 220 Swedish children had a mean score of 6.05 (a slightly higher mean score have been found in other countries, i.e. Belgium = 7.05 and USA = 8.24). The 7-year-olds had a significantly higher mean score than children at the other ages, except for the 15-year-olds. No other differences were found related to age, sex or size of community. The aspects of reliability and validity investigated for the CAT-S were satisfactory. Furthermore, there was no significant difference between the groups of 10-year-olds objected to different test procedures. Conclusions & Implications: The norm values of CAT-S could be used for comparison of scores from Swedish children with speech disorders. The CAT-S is easy to administer and could be used either in a group setting for research purpose or individually at the clinic. (Contains 2 tables.)
- Published
- 2009
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45. Putting Discourse to Work: Information Practices and the Professional Project of Nurses
- Author
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Johannisson, Jenny and Sundin, Olof
- Abstract
This article contributes to discourse-oriented, information-seeking research by showing how discourses, from a neopragmatist perspective, can be explored as tools that people employ when they actively engage in information practices in varied social contexts. A study of nurses and the nursing profession in Sweden is used as an empirical example of such a context, which is in the article understood as a community of justification. The nurses' accounts of information practices are further analyzed as expressions of their use of discourses as tools in the promotion of specific interests as to what the nursing profession should be. The analysis shows how the science-oriented medical discourse and the holistically oriented nursing discourse are two tools employed in the nurses' accounts of their information practices. In these discourses, which operate at both a workplace and an occupational level, a key component is what nurses consider to be relevant information.
- Published
- 2007
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46. Correlations between personality traits and specific groups of alpha waves in the human EEG
- Author
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Tomas Johannisson
- Subjects
Extraversion ,Neuroticism ,Alpha waves ,Temperament ,IPIP-NEO ,Cerebral cortex ,Medicine ,Biology (General) ,QH301-705.5 - Abstract
Background. Different individuals have alpha waves with different wavelengths. The distribution of the wavelengths is assumed to be bell-shaped and smooth. Although this view is generally accepted, it is still just an assumption and has never been critically tested. When exploring the relationship between alpha waves and personality traits, it makes a huge difference if the distribution of the alpha waves is smooth or if specific groups of alpha waves can be demonstrated. Previous studies have not considered the possibility that specific groups of alpha waves may exist. Methods. Computerized EEGs have become standard, but wavelength measurements are problematic when based on averaging procedures using the Fourier transformation because such procedures cause a large systematic error. If the actual wavelength is of interest, it is necessary to go back to basic physiology and use raw EEG signals. In the present study, measurements were made directly from sequences of alpha waves where every wave could be identified. Personality dimensions were measured using an inventory derived from the International Personality Item Pool. Results. Recordings from 200 healthy individuals revealed that there are three main groups of alpha waves. These groups had frequencies around 8, 10, and 12 waves per second. The middle group had a bimodal distribution, and a subdivision gave a total of four alpha groups. In the center of each group, the degree of extraversion was high and the degree of neuroticism was low. Many small differences in personality traits were found when the centers were compared with one another. This gave four personality profiles that resemble the four classical temperaments. When people in the surrounding zones were compared with those in the centers, relatively large differences in personality traits were found. Conclusions. Specific groups of alpha waves exist, and these groups have to be taken into account when correlations are made to personality dimensions and temperament types. There is a link between alpha waves and personality traits, and this link implies that there is an underlying relationship. To explain the nature of this relationship, there are two hypotheses that can be applied. One of these deals with the general organization of the forebrain and the other explains why the brain generates alpha waves.
- Published
- 2016
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47. Culture Unbound Vol. 4 Editorial
- Author
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Jenny Johannisson, Martin Fredriksson, and Johan Fornäs
- Subjects
General Works - Published
- 2012
- Full Text
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48. Culture Unbound Vol. 3 Editorial
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Johan Fornäs, Martin Fredriksson, and Jenny Johannisson
- Subjects
General Works - Published
- 2011
- Full Text
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49. Culture Unbound Vol. 2 Editorial
- Author
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Johan Fornäs, Martin Fredriksson, and Jenny Johannisson
- Subjects
General Works - Published
- 2010
- Full Text
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50. Sperm Quality during Storage Is Not Affected by the Presence of Antibiotics in EquiPlus Semen Extender but Is Improved by Single Layer Centrifugation
- Author
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Ziyad Al-Kass, Joachim Spergser, Christine Aurich, Juliane Kuhl, Kathrin Schmidt, Anders Johannisson, and Jane M. Morrell
- Subjects
pony stallions ,bacteria ,semen evaluation ,Therapeutics. Pharmacology ,RM1-950 - Abstract
Contamination of semen with bacteria arises during semen collection and handling. This bacterial contamination is typically controlled by adding antibiotics to semen extenders but intensive usage of antibiotics can lead to the development of bacterial resistance and may be detrimental to sperm quality. The objective of this study was to determine the effects of antibiotics in a semen extender on sperm quality and to investigate the effects of removal of bacteria by modified Single Layer Centrifugation (MSLC) through a colloid. Semen was collected from six adult pony stallions (three ejaculates per male). Aliquots of extended semen were used for MSLC with Equicoll, resulting in four treatment groups: control and MSLC in extender with antibiotics (CA and SA, respectively); control and MSLC in extender without antibiotics (CW and SW, respectively). Sperm motility, membrane integrity, mitochondrial membrane potential and chromatin integrity were evaluated daily by computer-assisted sperm analysis (CASA) and flow cytometry. There were no differences in sperm quality between CA and CW, or between SA and SW, although progressive motility was negatively correlated to total bacterial counts at 0 h. However, MSLC groups showed higher mean total motility (P < 0.001), progressive motility (P < 0.05), membrane integrity (P < 0.0001) and mitochondrial membrane potential (P < 0.05), as well as better chromatin integrity (P < 0.05), than controls. Sperm quality remained higher in the MSLC groups than controls throughout storage. These results indicate that sperm quality was not adversely affected by the presence of antibiotics but was improved considerably by MSLC.
- Published
- 2017
- Full Text
- View/download PDF
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