| 1. |
- Hibar, Derrek P., et al.
(författare)
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Novel genetic loci associated with hippocampal volume
- 2017
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- The hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are found in several common neuropsychiatric disorders. To identify the genetic underpinnings of hippocampal structure here we perform a genome-wide association study (GWAS) of 33,536 individuals and discover six independent loci significantly associated with hippocampal volume, four of them novel. Of the novel loci, three lie within genes (ASTN2, DPP4 and MAST4) and one is found 200 kb upstream of SHH. A hippocampal subfield analysis shows that a locus within the MSRB3 gene shows evidence of a localized effect along the dentate gyrus, subiculum, CA1 and fissure. Further, we show that genetic variants associated with decreased hippocampal volume are also associated with increased risk for Alzheimer's disease (r(g) = -0.155). Our findings suggest novel biological pathways through which human genetic variation influences hippocampal volume and risk for neuropsychiatric illness.
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| 2. |
- Cuni-Sanchez, Aida, et al.
(författare)
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High aboveground carbon stock of African tropical montane forests
- 2021
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 596:7873, s. 536-542
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Tidskriftsartikel (refereegranskat)abstract
- Tropical forests store 40–50 per cent of terrestrial vegetation carbon. However, spatial variations in aboveground live tree biomass carbon (AGC) stocks remain poorly understood, in particular in tropical montane forests. Owing to climatic and soil changes with increasing elevation, AGC stocks are lower in tropical montane forests compared with lowland forests. Here we assemble and analyse a dataset of structurally intact old-growth forests (AfriMont) spanning 44 montane sites in 12 African countries. We find that montane sites in the AfriMont plot network have a mean AGC stock of 149.4 megagrams of carbon per hectare (95% confidence interval 137.1–164.2), which is comparable to lowland forests in the African Tropical Rainforest Observation Network4 and about 70 per cent and 32 per cent higher than averages from plot networks in montane and lowland forests in the Neotropics, respectively. Notably, our results are two-thirds higher than the Intergovernmental Panel on Climate Change default values for these forests in Africa8. We find that the low stem density and high abundance of large trees of African lowland forests is mirrored in the montane forests sampled. This carbon store is endangered: we estimate that 0.8 million hectares of old-growth African montane forest have been lost since 2000. We provide country-specific montane forest AGC stock estimates modelled from our plot network to help to guide forest conservation and reforestation interventions. Our findings highlight the need for conserving these biodiverse and carbon-rich ecosystems.
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| 3. |
- Zody, Michael C., et al.
(författare)
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Evolutionary toggling of the MAPT 17q21.31 inversion region
- 2008
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 40:9, s. 1076-83
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Tidskriftsartikel (refereegranskat)abstract
- Using comparative sequencing approaches, we investigated the evolutionary history of the European-enriched 17q21.31 MAPT inversion polymorphism. We present a detailed, BAC-based sequence assembly of the inverted human H2 haplotype and compare it to the sequence structure and genetic variation of the corresponding 1.5-Mb region for the noninverted H1 human haplotype and that of chimpanzee and orangutan. We found that inversion of the MAPT region is similarly polymorphic in other great ape species, and we present evidence that the inversions occurred independently in chimpanzees and humans. In humans, the inversion breakpoints correspond to core duplications with the LRRC37 gene family. Our analysis favors the H2 configuration and sequence haplotype as the likely great ape and human ancestral state, with inversion recurrences during primate evolution. We show that the H2 architecture has evolved more extensive sequence homology, perhaps explaining its tendency to undergo microdeletion associated with mental retardation in European populations.
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| 4. |
- Hardy, Kenneth A., et al.
(författare)
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Elemental Constituents of Miami Aerosol as Function of Particle Size
- 1976
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Ingår i: Environmental Science & Technology. - : American Chemical Society (ACS). - 1520-5851 .- 0013-936X. ; 10:2, s. 176-182
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Tidskriftsartikel (refereegranskat)abstract
- Results are presented of proton-induced x-ray emission analysis of aerosol samples taken in Miami, Fla., in the summer of 1974. Elemental concentrations and elemental ratios as a function of particle size are shown for 13 elements. These size distributions allow the determination of the sources of several elements observed in the Miami aerosol. Data from north Florida and Bermuda are compared.
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| 5. |
- Reddy, Mareddy, 1993, et al.
(författare)
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Experimental review of the performances of protective coatings for interconnects in solid oxide fuel cells
- 2023
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Ingår i: Journal of Power Sources. - : Elsevier BV. - 0378-7753. ; 568
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Tidskriftsartikel (refereegranskat)abstract
- Ferritic stainless steel interconnects are used in solid oxide fuel cells; however, coatings are required to improve their performance. Although several types of coatings have been proposed, they have been scarcely investigated under similar conditions. This study compares the characteristics of uncoated Crofer 22 APU and eight different coatings on Crofer 22 APU for up to 3000 h at 800 °C. The coatings were deposited at various research laboratories around the world, and the experiments were performed at Chalmers University of Technology, Sweden. Cross-sections of the samples were analysed using scanning electron microscopy and energy-dispersive x-ray spectroscopy. The (Co,Mn)-based coated steels showed more than 50-fold lower chromium evaporation and at least 3 times thinner Cr2O3 scale thickness compared to uncoated steel. The coated steel samples showed lower area-specific resistance (ASR) values than the uncoated steel after 3000 h of exposure, irrespective of the coating thickness, composition and deposition method.
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| 6. |
- Akselsson, Roland, et al.
(författare)
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X-Ray Techniques for Aerosol Sulfur Baseline Assessment Along an Urban Freeway
- 1976
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Ingår i: Advances in X-Ray Analysis. ; 19, s. 415-425
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Tidskriftsartikel (refereegranskat)abstract
- Atmospheric aerosol particles have been sampled near a Los Angeles freeway and analyzed by proton-induced X-ray emission, PIXE, as a sulfur baseline study in September 1974 before 1975-model automobiles, equipped with catalytic emission control devices, appeared in large numbers. The sampling plan was optimized according to the requirements of X-ray analysis techniques, fluctuations in air flow across the freeway, and the time and particle size resolution of the aerosol sampling equipment. During five selected two-hour intervals with cross wind conditions, particles were collected as a function of size by six cascade impactors operating simultaneously on three towers at 2 and 7 meters above road level 35 meters upwind and 35 meters downwind of the traffic lanes. Particles as a function of time were sampled continuously, for the 100-hour duration of the experiment, from the tree 7-meter heights using time series streaker filter samplers with two-hour time resolution. Precise analysis of S, Cl, K, Ca, Fe, Br, and Pb established relationships which permit estimates to be made of future increases in particulate sulfur as a consequence of increased sulfate emissions from catalytic automobiles
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| 7. |
- Andersson, Bo, Docent, 1965-, et al.
(författare)
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Enhancing Information Quality as Part of the Disease Surveillance System in Malawi, Africa : Reflections on a mHealth Intervention
- 2017
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Ingår i: Information Systems Development: Advances in Methods, Tools and Management. - Larnaca : Association for Information Systems. - 9789963228836
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Konferensbidrag (refereegranskat)abstract
- Public health surveillance and response to disease outbreaks is still a hurdle in many developing countries across sub-Saharan Africa. Pivotal in disease surveillance and response is the reliance on valid information, hence, the need for information which has high Information Quality (IQ) characteristics. A key issue with disease surveillance systems, stem from the diverse range of data sources with various levels of information quality that may affect the trustworthiness of the information. However, with the increasing diffusion of mobile phone technologies, there are opportunities to improve IQ. The aim of this study was to assess the information quality in data collected through a smartphone application. Based on qualitative data from interviews, workshop and system specifications, it was found that information quality improves with the use of smartphone applications but aspects such as user competence and trustworthiness, must be addressed to maximize the benefits of using mobile technologies for disease surveillance.
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| 8. |
- Chirambo, Griphin Baxter, et al.
(författare)
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Effectiveness of Smartphone-Based Community Case Management on the Urgent Referral, Reconsultation, and Hospitalization of Children Aged Under 5 Years in Malawi : Cluster-Randomized, Stepped-Wedge Trial
- 2021
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Ingår i: Journal of Medical Internet Research. - : JMIR Publications. - 1438-8871. ; 23:10
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Integrated community case management (CCM) has led to reductions in child mortality in Malawi resulting from illnesses such as malaria, pneumonia, and diarrhea. However, adherence to CCM guidelines is often poor, potentially leading to inappropriate clinical decisions and poor outcomes. We determined the impact of an e-CCM app on the referral, reconsultation, and hospitalization rates of children presenting to village clinics in Malawi.OBJECTIVE: We determined the impact of an electronic version of a smartphone-based CCM (e-CCM) app on the referral, reconsultation, and hospitalization rates of children presenting to village clinics in Malawi.METHODS: We used a stepped-wedge, cluster-randomized trial to compare paper-based CCM (control) with and without the use of an e-CCM app on smartphones from November 2016 to February 2017. A total of 102 village clinics from 2 districts in northern Malawi were assigned to 1 of 6 clusters, which were randomized on the sequencing of the crossover from the control phase to the intervention phase as well as the duration of exposure in each phase. Children aged ≥2 months to <5 years who presented with acute illness were enrolled consecutively by health surveillance assistants. The primary outcome of urgent referrals to higher-level facilities was evaluated by using multilevel mixed effects models. A logistic regression model with the random effects of the cluster and the fixed effects for each step was fitted. The adjustment for potential confounders included baseline factors, such as patient age, sex, and the geographical location of the village clinics. Calendar time was adjusted for in the analysis.RESULTS: A total of 6965 children were recruited-49.11% (3421/6965) in the control phase and 50.88% (3544/6965) in the intervention phase. After adjusting for calendar time, children in the intervention phase were more likely to be urgently referred to a higher-level health facility than children in the control phase (odds ratio [OR] 2.02, 95% CI 1.27-3.23; P=.003). Overall, children in the intervention arm had lower odds of attending a repeat health surveillance assistant consultation (OR 0.45, 95% CI 0.34-0.59; P<.001) or being admitted to a hospital (OR 0.75, 95% CI 0.62-0.90; P=.002), but after adjusting for time, these differences were not significant (P=.07 for consultation; P=.30 for hospital admission).CONCLUSIONS: The addition of e-CCM decision support by using smartphones led to a greater proportion of children being referred to higher-level facilities, with no apparent increase in hospital admissions or repeat consultations in village clinics. Our findings provide support for the implementation of e-CCM tools in Malawi and other low- and middle-income countries with a need for ongoing assessments of effectiveness and integration with national digital health strategies.TRIAL REGISTRATION: ClinicalTrials.gov NCT02763345; https://clinicaltrials.gov/ct2/show/NCT02763345.
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| 9. |
- Chirambo, Griphin Baxter, et al.
(författare)
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End-user perspectives of two mHealth decision support tools : Electronic Community Case Management in Northern Malawi
- 2021
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Ingår i: International Journal of Medical Informatics. - : Elsevier BV. - 1386-5056 .- 1872-8243. ; 145
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Tidskriftsartikel (refereegranskat)abstract
- Background: The introduction of a paper-based Community Case Management (CCM) in Malawi has contributed to a reduction of child morbidity and mortality rates. In addition, the introduction of electronic Community Case Management (eCCM) (smartphones with built in CCM apps) may help to reduce the under-five mortality rates even further. Purpose: It is not uncommon for Apps with a similar area of interest to develop different features to assist the end users. Such differences between Apps may have a significant role to play in its overall adoption and integration. The purpose of this research was to explore end users perspectives of two eCCM decision support tools developed and implemented by the Supporting LIFE project (SL eCCM App) and D-Tree International's (Mangologic eCCM App)in Northern Malawi. Methods: A mixed methods approach was applied, involving a survey of 109 users (106 Health Surveillance Assistants (HSAs), and 3 Integrated Management of Childhood Il6lnesses (IMCI) coordinators). This was followed up with semi-structured interviews with 34 respondents (31 HSAs, and 3 IMCI coordinators). Quantitative data was analyzed using SPSS version 20 where descriptive statistics and Chi-Squared tests were generated. Qualitative data were analyzed based on thematic analysis. Results: Participants reported that both Apps could assist the HSAs in the management of childhood illnesses. However, usability differed between the two apps where the Supporting LIFE eCCM App was found to be easier to use (61%) compared to the Mangologic eCCM App (4%). Both Apps were perceived to provide credible and accurate information. Conclusion: It is essential that the quality of the data within Mobile Health (mHealth) Apps is high, however even Apps with excellent levels of data quality may not succeed if the overall usability of the App is low. Therefore it is essential that the Apps has high levels of data quality, usability and credibility. The results of this study will help inform mobile Health (mHealth) App designers in developing future eCCM Apps as well as researchers and policy makers when considering the adoption of mHealth solutions in the future in Malawi and other LMICs.
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| 10. |
- Chirambo, Griphin Baxter, et al.
(författare)
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Perceptions of a mobile health intervention for Community Case Management in Malawi : Opportunities and challenges for Health Surveillance Assistants in a community setting
- 2018
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Ingår i: Malawi Medical Journal. - : African journals online (AJOL). - 1995-7262 .- 1995-7270. ; 30:1, s. 6-12
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Tidskriftsartikel (refereegranskat)abstract
- Background: Improved availability of mobile phones in low- and middle-income countries (LMICs) offer an opportunity to improve delivery of Community Case Management (CCM). Despite enthusiasm for introducing mHealth into healthcare across LMICs, end-user attitudes towards mHealth solutions for CCM are limited. We aimed to explore Health Surveillance Assistants' (HSAs) perceptions of the Supporting LIFE electronic CCM Application (SL eCCM App) and their experiences incorporating it as part of their clinical practice.Methods: This exploratory qualitative study was part of a mixed methods feasibility study investigating whether children under-5 presenting to village clinics could be followed-up to collect patient outcome data. The convenience sample of 12 HSAs enrolled into the feasibility study participated in semi-structured interviews, which were conducted at village clinics after HSAs had field-tested the SL eCCM App over a 10-day period. Interviews explored HSAs perceptions of the SL eCCM App and their experiences in using the App in addition to paper CCM to assess and treat acutely unwell children. Open coding was used to label emerging concepts, which were iteratively defined and developed into six key themes.Results: HSAs' perceived enhanced clinical decision-making, quality of CCM delivery, and work efficiency as opportunities associated with using the SL eCCM App. HSAs believed the inability to retrieve patient records,, cumbersome duplicate assessments/data entry study procedures, and inconsistencies between the SL eCCM App and paper-based CCM guidelines as challenges to implementation. Adding features to the App, such as, permitting communication between colleagues/supervisors, drug stock-out reporting, and community assessments, were identified as potentially supporting HSAs' many roles in the community.Conclusion: This study identified opportunities and challenges associated with using the SL eCCM App in Malawi. This information can be used to inform future development and evaluation of the SL eCCM App, and similar mHealth solutions for CCM in Malawi and other developing countries.
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