| 41. |
- Kalman, Janos L, et al.
(författare)
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Investigating polygenic burden in age at disease onset in bipolar disorder: Findings from an international multicentric study.
- 2019
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Ingår i: Bipolar disorders. - : Wiley. - 1399-5618 .- 1398-5647. ; 21:1, s. 68-75
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Tidskriftsartikel (refereegranskat)abstract
- Bipolar disorder (BD) with early disease onset is associated with an unfavorable clinical outcome and constitutes a clinically and biologically homogenous subgroup within the heterogeneous BD spectrum. Previous studies have found an accumulation of early age at onset (AAO) in BD families and have therefore hypothesized that there is a larger genetic contribution to the early-onset cases than to late onset BD. To investigate the genetic background of this subphenotype, we evaluated whether an increased polygenic burden of BD- and schizophrenia (SCZ)-associated risk variants is associated with an earlier AAO in BD patients.A total of 1995 BD type 1 patients from the Consortium of Lithium Genetics (ConLiGen), PsyCourse and Bonn-Mannheim samples were genotyped and their BD and SCZ polygenic risk scores (PRSs) were calculated using the summary statistics of the Psychiatric Genomics Consortium as a training data set. AAO was either separated into onset groups of clinical interest (childhood and adolescence [≤18 years] vs adulthood [>18 years]) or considered as a continuous measure. The associations between BD- and SCZ-PRSs and AAO were evaluated with regression models.BD- and SCZ-PRSs were not significantly associated with age at disease onset. Results remained the same when analyses were stratified by site of recruitment.The current study is the largest conducted so far to investigate the association between the cumulative BD and SCZ polygenic risk and AAO in BD patients. The reported negative results suggest that such a polygenic influence, if there is any, is not large, and highlight the importance of conducting further, larger scale studies to obtain more information on the genetic architecture of this clinically relevant phenotype.
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| 42. |
- Khalil, Ibrahim, et al.
(författare)
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Burden of Diarrhea in the Eastern Mediterranean Region, 1990-2013 : Findings from the Global Burden of Disease Study 2013
- 2016
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Ingår i: American Journal of Tropical Medicine and Hygiene. - : American Society of Tropical Medicine and Hygiene. - 1476-1645 .- 0002-9637. ; 95:6, s. 1319-1329
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Tidskriftsartikel (refereegranskat)abstract
- Diarrheal diseases (DD) are leading causes of disease burden, death, and disability, especially in children in low-income settings. DD can also impact a child's potential livelihood through stunted physical growth, cognitive impairment, and other sequelae. As part of the Global Burden of Disease Study, we estimated DD burden, and the burden attributable to specific risk factors and particular etiologies, in the Eastern Mediterranean Region (EMR) between 1990 and 2013. For both sexes and all ages, we calculated disability-adjusted life years (DALYs), which are the sum of years of life lost and years lived with disability. We estimate that over 125,000 deaths (3.6% of total deaths) were due to DD in the EMR in 2013, with a greater burden of DD in low- and middle-income countries. Diarrhea deaths per 100,000 children under 5 years of age ranged from one (95% uncertainty interval [UI] = 0-1) in Bahrain and Oman to 471 (95% UI = 245-763) in Somalia. The pattern for diarrhea DALYs among those under 5 years of age closely followed that for diarrheal deaths. DALYs per 100,000 ranged from 739 (95% UI = 520-989) in Syria to 40,869 (95% UI = 21,540-65,823) in Somalia. Our results highlighted a highly inequitable burden of DD in EMR, mainly driven by the lack of access to proper resources such as water and sanitation. Our findings will guide preventive and treatment interventions which are based on evidence and which follow the ultimate goal of reducing the DD burden.
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| 43. |
- Mgongo, Melina Bernard, et al.
(författare)
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A Qualitative Study on Barriers to COVID-19 Vaccine Uptake among Community Members in Tanzania
- 2023
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Ingår i: Vaccines. - 2076-393X. ; 11:8, s. 1-13
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Tidskriftsartikel (refereegranskat)abstract
- The use of vaccines is one of the key tools in reversing the COVID-19 pandemic; however, various reports reported the low uptake of the vaccines. This study explored the barriers to the COVID-19 vaccine uptake among community members in Tanzania. A qualitative explorative study was conducted in December 2021 and April 2022 in eight regions of Tanzania. Focus group discussions (FGDs) and in-depth interviews (IDIs) were the methods of data collection. A total of 48 FGDs and 32 IDIs were conducted. Participants were aware of the COVID-19 disease and vaccines. The barriers to the COVID-19 vaccine non-uptake included receiving contradicting statements from top government leaders, vaccine preceded the education, myths towards vaccines, the presence of different types of vaccines, the process of getting the vaccine, the influence of social media and random people from the community, and vaccine conflicting religious beliefs. Despite being aware of the vaccine, the uptake of the COVID-19 vaccine is still low. Interventions that focus on increasing community knowledge about COVID-19 vaccines and addressing myths about the vaccines are needed.
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| 44. |
- Satapathy, Kaushik, et al.
(författare)
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The Variability of the Black Hole Image in M87 at the Dynamical Timescale
- 2022
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 1538-4357 .- 0004-637X. ; 925:1
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Tidskriftsartikel (refereegranskat)abstract
- The black hole images obtained with the Event Horizon Telescope (EHT) are expected to be variable at the dynamical timescale near their horizons. For the black hole at the center of the M87 galaxy, this timescale (5-61 days) is comparable to the 6 day extent of the 2017 EHT observations. Closure phases along baseline triangles are robust interferometric observables that are sensitive to the expected structural changes of the images but are free of station-based atmospheric and instrumental errors. We explored the day-to-day variability in closure-phase measurements on all six linearly independent nontrivial baseline triangles that can be formed from the 2017 observations. We showed that three triangles exhibit very low day-to-day variability, with a dispersion of similar to 3 degrees-5 degrees. The only triangles that exhibit substantially higher variability (similar to 90 degrees-180 degrees) are the ones with baselines that cross the visibility amplitude minima on the u-v plane, as expected from theoretical modeling. We used two sets of general relativistic magnetohydrodynamic simulations to explore the dependence of the predicted variability on various black hole and accretion-flow parameters. We found that changing the magnetic field configuration, electron temperature model, or black hole spin has a marginal effect on the model consistency with the observed level of variability. On the other hand, the most discriminating image characteristic of models is the fractional width of the bright ring of emission. Models that best reproduce the observed small level of variability are characterized by thin ring-like images with structures dominated by gravitational lensing effects and thus least affected by turbulence in the accreting plasmas.
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| 45. |
- Torne, Pablo, et al.
(författare)
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A Search for Pulsars around Sgr A* in the First Event Horizon Telescope Data Set
- 2023
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Ingår i: Astrophysical Journal. - 1538-4357 .- 0004-637X. ; 959:1
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Tidskriftsartikel (refereegranskat)abstract
- In 2017 the Event Horizon Telescope (EHT) observed the supermassive black hole at the center of the Milky Way, Sagittarius A* (Sgr A*), at a frequency of 228.1 GHz (lambda = 1.3 mm). The fundamental physics tests that even a single pulsar orbiting Sgr A* would enable motivate searching for pulsars in EHT data sets. The high observing frequency means that pulsars-which typically exhibit steep emission spectra-are expected to be very faint. However, it also negates pulse scattering, an effect that could hinder pulsar detections in the Galactic center. Additionally, magnetars or a secondary inverse Compton emission could be stronger at millimeter wavelengths than at lower frequencies. We present a search for pulsars close to Sgr A* using the data from the three most sensitive stations in the EHT 2017 campaign: the Atacama Large Millimeter/submillimeter Array, the Large Millimeter Telescope, and the IRAM 30 m Telescope. We apply three detection methods based on Fourier-domain analysis, the fast folding algorithm, and single-pulse searches targeting both pulsars and burst-like transient emission. We use the simultaneity of the observations to confirm potential candidates. No new pulsars or significant bursts were found. Being the first pulsar search ever carried out at such high radio frequencies, we detail our analysis methods and give a detailed estimation of the sensitivity of the search. We conclude that the EHT 2017 observations are only sensitive to a small fraction (less than or similar to 2.2%) of the pulsars that may exist close to Sgr A*, motivating further searches for fainter pulsars in the region.
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| 46. |
- Wielgus, Maciek, et al.
(författare)
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Millimeter Light Curves of Sagittarius A* Observed during the 2017 Event Horizon Telescope Campaign
- 2022
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Ingår i: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8213 .- 2041-8205. ; 930:2
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Tidskriftsartikel (refereegranskat)abstract
- The Event Horizon Telescope (EHT) observed the compact radio source, Sagittarius A* (Sgr A*), in the Galactic Center on 2017 April 5-11 in the 1.3 mm wavelength band. At the same time, interferometric array data from the Atacama Large Millimeter/submillimeter Array and the Submillimeter Array were collected, providing Sgr A* light curves simultaneous with the EHT observations. These data sets, complementing the EHT very long baseline interferometry, are characterized by a cadence and signal-to-noise ratio previously unattainable for Sgr A* at millimeter wavelengths, and they allow for the investigation of source variability on timescales as short as a minute. While most of the light curves correspond to a low variability state of Sgr A*, the April 11 observations follow an X-ray flare and exhibit strongly enhanced variability. All of the light curves are consistent with a red-noise process, with a power spectral density (PSD) slope measured to be between -2 and -3 on timescales between 1 minute and several hours. Our results indicate a steepening of the PSD slope for timescales shorter than 0.3 hr. The spectral energy distribution is flat at 220 GHz, and there are no time lags between the 213 and 229 GHz frequency bands, suggesting low optical depth for the event horizon scale source. We characterize Sgr A*'s variability, highlighting the different behavior observed just after the X-ray flare, and use Gaussian process modeling to extract a decorrelation timescale and a PSD slope. We also investigate the systematic calibration uncertainties by analyzing data from independent data reduction pipelines.
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| 47. |
- Abdel, Naseem S., et al.
(författare)
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Modification of spray-deposited CdO thin films by 1.5 MeV proton irradiation
- 2022
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Ingår i: Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 511, s. 57-63
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Tidskriftsartikel (refereegranskat)abstract
- Thin films of cadmium oxide (CdO) with different thicknesses in the range of 78–250 nm were prepared and deposited on glass substrates by using a spray pyrolysis technique. A microbeam facility (Lund Ion Beam Analysis facility) was used to irradiate the prepared CdO thin films with a 1.5 MeV proton beam for fluence in the range of 2 × 1012–2 × 1014 ions/cm2. The surface morphology of the CdO films was measured by atomic force microscopy, and it was observed that the grain size and surface roughness were increased as a function of ion fluence. A UV spectrophotometer was used to study the optical properties of the samples, and the results revealed that the absorbance and optical band gaps increased with an increase in the proton fluence and CdO film's thickness. This work explores the possibility of CdO material modification using low-energy proton irradiation.
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| 48. |
- Abi Nassif, L., et al.
(författare)
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Reduction of potential ennoblement of stainless steel in natural seawater by an ecofriendly biopolymer
- 2020
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Ingår i: Journal of Environmental Chemical Engineering. - : Elsevier Ltd. - 2213-3437. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- The effect of biofilm formation on passive stainless steel in seawater environments is of primary importance since it leads to potential ennoblement of surfaces and subsequently to localized corrosion such as pitting and crevice corrosion. This study aims at developing an ecofriendly alginate biopolymer containing both non-toxic calcium and a limited amount of biocidal zinc ions which inhibits this effect. For this purpose, calcium alginate containing less than 1 % of zinc ions localized in the vicinity of the steel surface in natural and renewed seawater is demonstrated to reduce significantly the ennoblement process of steel. After 1 month of immersion, a mass loss of only 4 % of the active material is observed authorizing thereby long-term protection of steel in real environment.
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| 49. |
- Ahmed, Naeem, et al.
(författare)
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Effects of Oxygen (O2) Plasma Treatment in Promoting the Germination and Growth of Chili
- 2022
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Ingår i: Plasma chemistry and plasma processing. - : Springer. - 0272-4324 .- 1572-8986. ; 42:1, s. 91-108
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Tidskriftsartikel (refereegranskat)abstract
- In general, seed germination is improved by low-pressure plasma treatment using precursors such as air, nitrogen, O2, and argon, etc. For the first time, low-pressure O2 plasma was used to treat chili seeds in this study. When compared to untreated and vacuum-treated seeds, O2 plasma treatment using the discharge power of 80 W for 60 s significantly improves chili seed germination and growth. The effect of vacuum on the germination and growth of chili seeds was also studied and shown to be negligible. The physical and chemical changes induced by O2 plasma treatment were investigated to understand the plasma treatment to germination improvement. Combinatory etching and chemical modification aided imbibition and increased germination percentage in this O2 plasma treatment on chili seeds. The success of this method has the potential to be scaled up to solve food security issues with seeds that would otherwise struggle to germinate.
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| 50. |
- Ahmed, Naeem, et al.
(författare)
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Germination and growth improvement of papaya utilizing oxygen (O2) plasma treatment
- 2022
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Ingår i: Journal of Physics D. - : Institute of Physics (IOP). - 0022-3727 .- 1361-6463. ; 55:25
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Tidskriftsartikel (refereegranskat)abstract
- In general, cold plasma treatment improves crop germination and growth. The purpose of this research is to examine the impact of low-pressure O2 plasma treatment on the germination and growth kinetics of papaya seeds. Seeds were treated for 40 s at a discharge power of 80 W using O2 as a monomer. Physical and chemical changes were studied to understand the mechanism of germination and growth improvement. Furthermore, changes in phytohormones and antioxidant activity that were beneficial to germination were also examined. O2 plasma treatment improved wettability, surface etching, and oxidation, and affected other molecular-level changes leading to a 16% germination improvement in papaya.
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