| 1. |
- Svensson, Ola, 1971, et al.
(författare)
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Offspring recognition and the influence of clutch size on nest fostering among male sand gobies, Pomatoschistus minutus
- 2010
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Ingår i: Behavioral Ecology and Sociobiology. - Heidelberg : Springer. - 0340-5443 .- 1432-0762. ; 64:8, s. 1325-1331
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Tidskriftsartikel (refereegranskat)abstract
- When parental care is costly, parents should avoid caring for unrelated young. Therefore, it is an advantage to discriminate between related and unrelated offspring so that parents can make informed decisions about parental care. In the present study, we test the hypothesis that male sand gobies (Pomatoschistus minutus) recognize and differentially care for their own offspring when given a choice between a nest with sired eggs and a second nest with eggs sired by an unrelated male. The sand goby is a species with exclusive and costly paternal care. Male parasitic spawnings (e.g., sneaking) as well as nest takeovers by other males are common. Our results show that nests containing sired eggs were preferred and received significantly more care, as measured by nest building and nest occupancy, than nests with foreign eggs even when males cared for both nests. These findings suggest that males respond to paternity cues and recognize their own clutches. Relative clutch size also had a significant effect on male parental care. When sired clutches were larger than foreign clutches, males preferred to care for their own nest. In the few cases where males chose to take care of foreign nests, the foreign clutch was larger than their own clutch. Taken together, our results provide evidence that both paternity cues and clutch size influence parenting decisions among male sand gobies.
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| 2. |
- Bergström, Jenny, et al.
(författare)
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Becoming materials : material forms and forms of practice
- 2010
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Ingår i: Digital Creativity. - : Routledge. - 1462-6268 .- 1744-3806. ; 21:3, s. 155-172
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Tidskriftsartikel (refereegranskat)abstract
- As a result of development toward ‘smart’ materials, materials now enable an expanding range of aesthetic expressions and user experiences. These materials are fundamentally temporal in their capacity to assume multiple, discrete states of expression that can be repeatedly and minutely controlled. These materials come to be, or become, only over time and in context—they are becoming materials. Thus, in the development and application of such materials, we must engage more extensively with the experience of materials in practices of design and of use. This paper introduces and discusses the concept of becoming materials—as well as the implications for practice—through a series of examples from our own practice-led research within art, design and architecture. Coming to terms with the implications for material practices of design and of use, we suggest, requires the development of new concepts and methods for doing and studying the design of becoming materials.
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| 3. |
- Guo, Li, et al.
(författare)
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Design of a garment-based sensing system for breathing monitoring
- 2013
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Ingår i: Textile research journal. - : SAGE Publications. - 0040-5175 .- 1746-7748. ; 83:5, s. 499-509
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Tidskriftsartikel (refereegranskat)abstract
- The long-term monitoring of biophysiological signals requires new types of sensor systems that are wearable and at the same time convenient for the users. This paper describes the design of a novel garment-based sensing system for the long-term monitoring of breathing rhythm. The system concept was realized in a prototype garment, integrated with coated piezoresistive sensors. The prototype garment was tested by five subjects, and compared with a standard piezoelectric respiratory belt. Each signal was quantitatively and qualitatively evaluated in the time and frequency domain to make sure that no medical and diagnostic information was lost. The results showed a good agreement between the garment-based sensors and the standard reference, where errors occurred only when the breathing rate was extremely high. The garment-based sensor system could also distinguish the predominance breathing compartment (chest versus abdominal breathing). The system could detect a 10 s pause in breathing, which could be of importance in studies of sleep apnea. A garment-based sensing system maintains the accuracy of the signal quality without reducing the comfort for the user. It makes possible long-term ambulatory monitoring and has home-based healthcare applications.
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| 4. |
- Sundberg, Bodil, 1966-, et al.
(författare)
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The Development of Pre-school Student Teachers´ Attitudes Towards Science and Science Teaching During Their University Studies
- 2010
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Ingår i: Contemporary science education research. - Istanbul : Ankara Pegem Akademi. - 9786053640325 ; , s. 157-166, s. 157-166
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Konferensbidrag (refereegranskat)abstract
- Considerable concern has been raised in Sweden about decreasing interest in science among young people. One key to improving attitudes towards science is an early positive contact with science. Numerous studies have however shown that elementary and pre-school teacher generally have negative attitudes towards science and science teaching, as well as poor science content knowledge. As a consequence, science teaching in pre-schools often is fragmented. A pre-school teacher education that prepares student teachers for teaching science with confidence has therefore been put forward as a way of increasing quality science teaching in pre-schools. In this longitudinal study, attitudes towards science and science teaching of students enrolled in a science and art oriented pre-school teacher programme were followed during their first years of university studies.The results show that the socialization process into the scientific discourse takes time, and that one full year of exposure to activities with scientific content was needed for skeptical attitudes towards science to change. The results also indicate that dominant attitudes, norms and behaviors of the pre-school professional culture may clash with developing science teaching skills. Pre-school teacher education therefore also needs to communicate about these contradicting cultures.
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| 5. |
- Sundberg, Bodil, 1966-, et al.
(författare)
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What are the voices of becoming practitioners telling us about science in pre-school? : Pre-school student teachers´ attitudes towards science and science teaching - a longitudinal study.
- 2010
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Ingår i: 20th EECERA ANNUAL CONFERENCE. KNOWLEDGE AND VOICE IN EARLY CHILDHOOD. ; , s. 216-216
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Konferensbidrag (refereegranskat)abstract
- The aim of this study is to investigate the relationship between the developing professional identity and attitudes towards science teaching among student pre-school teachers. We see professional identity as a dynamic equilibrium between the professional self-image and the variety of roles (pre-school) teachers feel they have to play. Accordingly, professional identity can change over time through relevant others, events and experiences. In this longitudinal study, 65 students enrolled in an art and science dominated teacher programme have been followed since the start in august 2008. Results are presented from 4 consecutive questionnaires and an individual interview of 8 students. The results show that sceptical attitudes towards science decreased significantly after one year of science studies. On the contrary hesitance towards holding structured scientific activities persisted throughout the year. Results from the individual interviews confirm these findings. Here, the descriptions of perceived relevant roles of their profession are dominated by themes of caring and supporting, not teaching. The reluctance towards science teaching in early years thus appear to be more connected to student teachers’ view of the professional preschool teacher role, where structured teaching not is a pronounced part, than to negative attitudes towards science itself. These findings thereby contradict the general idea that the ambiguity about teaching science in pre-school among student teachers is connected to negative attitudes toward science as a subject. This new perspective suggests a need to integrate a discussion of the pre-school teacher role and professional identity into science courses for becoming pre-school teachers.
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| 6. |
- Benouar, Sara, et al.
(författare)
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Classification of impedance cardiography dZ/dt complex subtypes using pattern recognition artificial neural networks
- 2021
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Ingår i: Biomedizinische Technik (Berlin. Zeitschrift). - : Walter de Gruyter. - 1862-278X .- 0013-5585. ; 66:5, s. 515-527
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Tidskriftsartikel (refereegranskat)abstract
- In impedance cardiography (ICG), the detection of dZ/dt signal (ICG) characteristic points, especially the X point, is a crucial step for the calculation of hemodynamic parameters such as stroke volume (SV) and cardiac output (CO). Unfortunately, for beat-to-beat calculations, the accuracy of the detection is affected by the variability of the ICG complex subtypes. Thus, in this work, automated classification of ICG complexes is proposed to support the detection of ICG characteristic points and the extraction of hemodynamic parameters according to several existing subtypes. A novel pattern recognition artificial neural network (PRANN) approach was implemented, and a divide-and-conquer strategy was used to identify the five different waveforms of the ICG complex waveform with output nodes no greater than 3. The PRANN was trained, tested and validated using a dataset from four volunteers from a measurement of eight electrodes. Once the training was satisfactory, the deployed network was validated on two other datasets that were completely different from the training dataset. As an additional performance validation of the PRANN, each dataset included four volunteers for a total of eight volunteers. The results show an average accuracy of 96% in classifying ICG complex subtypes with only a decrease in the accuracy to 83 and 80% on the validation datasets. This work indicates that the PRANN is a promising method for automated classification of ICG subtypes, facilitating the investigation of the extraction of hemodynamic parameters from beat-to-beat dZ/dt complexes.
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| 7. |
- Benouar, Sara, et al.
(författare)
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Time-series NARX feedback neural network for forecasting impedance cardiography ICG missing points : a predictive model
- 2023
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Ingår i: Frontiers in Physiology. - : Frontiers Media S.A.. - 1664-042X. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- One of the crucial steps in assessing hemodynamic parameters using impedance cardiography (ICG) is the detection of the characteristic points in the dZ/dt ICG complex, especially the X point. The most often estimated parameters from the ICG complex are stroke volume and cardiac output, for which is required the left ventricular pre-ejection time. Unfortunately, for beat-to-beat calculations, the accuracy of detection is affected by the variability of the ICG complex subtypes. Thus, in this work, we aim to create a predictive model that can predict the missing points and decrease the previous work percentages of missing points to support the detection of ICG characteristic points and the extraction of hemodynamic parameters according to several existing subtypes. Thus, a time-series non-linear autoregressive model with exogenous inputs (NARX) feedback neural network approach was implemented to forecast the missing ICG points according to the different existing subtypes. The NARX was trained on two different datasets with an open-loop mode to ensure that the network is fed with correct feedback inputs. Once the training is satisfactory, the loop can be closed for multi-step prediction tests and simulation. The results show that we can predict the missing characteristic points in all the complexes with a success rate ranging between 75% and 88% in the evaluated datasets. Previously, without the NARX predictive model, the successful detection rate was 21%–30% for the same datasets. Thus, this work indicates a promising method and an accuracy increase in the detection of X, Y, O, and Z points for both datasets.
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| 8. |
- Soudham, Venkata Prabhakar, et al.
(författare)
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Acetosolv delignifi cation of marabou (Dichrostachys cinerea) wood with and without acid prehydrolysis
- 2011
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Ingår i: Forestry Studies in China. - : Beijing Linye Daxue, Beijing Forestry University. - 1008-1321 .- 1993-0372. ; 13:1, s. 64-70
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Tidskriftsartikel (refereegranskat)abstract
- The chemical composition of marabou (Dichrostachys cinerea) wood and its treatment with acetic acid were investigated. Two different treatment approaches, direct acetosolv and combined acid prehydrolysis/acetosolv, were evaluated. The effects of acetic acid concentration (50%, 70% and 90%) and temperature (normal boiling temperature and 121°C) on yield of solids, solubilization of lignin and hemicelluloses and recovery of cellulose were evaluated for both treatments. High solubilization of marabou components was observed in the direct acetosolv treatment at 121°C, especially at the highest acetic acid concentration, where around 84.8% of lignin and 78% of hemicelluloses were removed. When the material was subjected to acid prehydrolysis prior to acetosolv treatment, lignin solubilization was improved, especially at low acetic acid concentrations. Above 80% of the solubilized lignin was recovered from the liquors in the direct acetosolv treatment, but the recovery was lower in the combined treatment. Cellulose was well preserved in all the treatment schemes.
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| 9. |
- Benouar, Sara, et al.
(författare)
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First Steps Toward Automated Classification of Impedance Cardiography dZ/dt Complex Subtypes
- 2021
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Ingår i: 8th European Medical and Biological Engineering Conference. - Cham : Springer Science and Business Media Deutschland GmbH. - 9783030646097 - 9783030646103 ; , s. 563-573
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Konferensbidrag (refereegranskat)abstract
- The detection of the characteristic points of the complex of the impedance cardiography (ICG) is a crucial step for the calculation of hemodynamical parameters such as left ventricular ejection time, stroke volume and cardiac output. Extracting the characteristic points from the dZ/dt ICG signal is usually affected by the variability of the ICG complex and assembling average is the method of choice to smooth out such variability. To avoid the use of assembling average that might filter out information relevant for the hemodynamic assessment requires extracting the characteristics points from the different subtypes of the ICG complex. Thus, as a first step to automatize the extraction parameters, the aim of this work is to detect automatically the kind of dZ/dt complex present in the ICG signal. To do so artificial neural networks have been designed with two different configurations for pattern matching (PRANN) and tested to identify the 6 different ICG complex subtypes. One of the configurations implements a 6-classes classifier and the other implemented the divide and conquer approach classifying in two stages. The data sets used in the training, validation and testing process of the PRANNs includes a matrix of 1 s windows of the ICG complexes from the 60 s long recordings of dZ/dt signal for each of the 4 healthy male volunteers. A total of 240 s. As a result, the divide and conquer approach improve the overall classification obtained with the one stage approach on +26% reaching and average classification ration of 82%.
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| 10. |
- Hafid, Abdelakram, et al.
(författare)
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Evaluation of dZ/dt Complex Subtypes vs Ensemble Averaging Method for Estimation of Left Ventricular Ejection Time from ICG Recording
- 2021
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Ingår i: 8th European Medical and Biological Engineering ConferenceProceedings of the EMBEC 2020, November 29 – December 3, 2020 Portorož, Slovenia. - Cham : Springer Science and Business Media Deutschland GmbH. - 9783030646097 - 9783030646103 ; , s. 502-509
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Konferensbidrag (refereegranskat)abstract
- Impedance cardiography (ICG) was discovered nearly half a century ago, being proposed as noninvasive monitoring method for estimation of several hemodynamics parameter. Despite of nearly 5 decades of clinical research and use there is still certain controversy about its performance when estimating Left Ventricular Ejection Time (LVET). This work present a comparison between using the different ICG subtype waveform and the ensemble averaged (EA) method to calculate the LVET. The ICG has been recorded from four volunteers, and the LVET parameter has been calculated using the two approaches. The result shows that each volunteer have different percentage of subtypes, and the mean relative error between the two approaches for estimation of LVET varied between 0.62 to 2.9% with an average mean absolute percentage error of 18,02% ranging between 13.82 to 18.42%. © 2021, Springer Nature Switzerland AG.
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