| 1. |
- Addazi, Andrea, et al.
(author)
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Gravitational footprints of massive neutrinos and lepton number breaking
- 2020
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In: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 807
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Journal article (peer-reviewed)abstract
- We investigate the production of primordial Gravitational Waves (GWs) arising from First Order Phase Transitions (FOPTs) associated to neutrino mass generation in the context of type-I and inverse seesaw schemes. We examine both “high-scale” as well as “low-scale” variants, with either explicit or spontaneously broken lepton number symmetry U(1)L in the neutrino sector. In the latter case, a pseudo-Goldstone majoron-like boson may provide a candidate for cosmological dark matter. We find that schemes with softly-broken U(1)L and with single Higgs-doublet scalar sector lead to either no FOPTs or too weak FOPTs, precluding the detectability of GWs in present or near future measurements. Nevertheless, we found that, in the majoron-like seesaw scheme with spontaneously broken U(1)L at finite temperatures, one can have strong FOPTs and non-trivial primordial GW spectra which can fall well within the frequency and amplitude sensitivity of upcoming experiments, including LISA, BBO and u-DECIGO. However, GWs observability clashes with invisible Higgs decay constraints from the LHC. A simple and consistent fix is to assume the majoron-like mass to lie above the Higgs-decay kinematical threshold. We also found that the majoron-like variant of the low-scale seesaw mechanism implies a different GW spectrum than the one expected in the high-scale seesaw. This feature will be testable in future experiments. Our analysis shows that GWs can provide a new and complementary portal to test the neutrino mass generation mechanism.
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| 2. |
- Konda, Srinivasa Rao, et al.
(author)
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Influence of embedded NiO-nanoparticles on the nonlinear absorption of tungsten disulfide nanolayers
- 2023
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In: Optical materials (Amsterdam). - : Elsevier. - 0925-3467 .- 1873-1252. ; 138
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Journal article (peer-reviewed)abstract
- 2D transition metal dichalcogenides possess fascinating properties due to their direct bandgap, strong spin-orbit coupling, and promising electronic/mechanical properties. In this work, we synthesized pure tungsten disulfide (WS2) nanolayers and NiO nanoparticles (NPs) decorated in few-layered WS2 and measured the third-order nonlinear optical properties using femtosecond Z-scan measurements. The open aperture Z-scan data illustrated that the inclusion of NiO nanoparticles into the WS2 layers increases the nonlinear absorption at 800 and 400 nm wavelengths. Furthermore, we observed the switchability of the nonlinear absorption from saturable absorption to two-photon absorption or reverse saturable absorption by changing the pump intensity. Thus, the embedded NiO NPs played a crucial role in the variation of intensity-dependent nonlinear absorption mechanism of WS2 nanolayers and thus can be helpful for various optical applications such as laser pulse compression and optical limiting to prevent over-exposure of protective photosensitive sensors by intense ultrashort laser pulses.
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| 3. |
- Kumar, Sanjiv, et al.
(author)
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Identification of Growth Inhibitors of the Fish Pathogen Saprolegnia parasitica Using in silico Subtractive Proteomics, Computational Modeling, and Biochemical Validation
- 2020
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In: Frontiers in Microbiology. - : FRONTIERS MEDIA SA. - 1664-302X. ; 11
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Journal article (peer-reviewed)abstract
- Many Stramenopile species belonging to oomycetes from the genus Saprolegnia infect fish, amphibians, and crustaceans in aquaculture farms and natural ecosystems. Saprolegnia parasitica is one of the most severe fish pathogens, responsible for high losses in the aquaculture industry worldwide. Most of the molecules reported to date for the control of Saprolegnia infections either are inefficient or have negative impacts on the health of the fish hosts or the environment resulting in substantial economic losses. Until now, the whole proteome of S. parasitica has not been explored for a systematic screening of novel inhibitors against the pathogen. The present study was designed to develop a consensus computational framework for the identification of potential target proteins and their inhibitors and subsequent experimental validation of selected compounds. Comparative analysis between the proteomes of Saprolegnia, humans and fish species identified proteins that are specific and essential for the survival of the pathogen. The DrugBank database was exploited to select food and drug administration (FDA)-approved inhibitors whose high binding affinity to their respective protein targets was confirmed by computational modeling. At least six of the identified compounds significantly inhibited the growth of S. parasitica in vitro. Triclosan was found to be most effective with a minimum inhibitory concentration (MIC100) of 4 mu g/ml. Optical microscopy showed that the inhibitors affect the morphology of hyphal cells, with hyper-branching being commonly observed. The inhibitory effects of the compounds identified in this study on Saprolegnia's mycelial growth indicate that they are potentially usable for disease control against this class of oomycete pathogens. Similar approaches can be easily adopted for the identification of potential inhibitors against other plant and animal pathogenic oomycete infections.
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| 4. |
- Streatfield, P. Kim, et al.
(author)
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Malaria mortality in Africa and Asia : evidence from INDEPTH health and demographic surveillance system sites
- 2014
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In: Global Health Action. - : Informa UK Limited. - 1654-9716 .- 1654-9880. ; 7, s. 25369-
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Journal article (peer-reviewed)abstract
- BACKGROUND: Malaria continues to be a major cause of infectious disease mortality in tropical regions. However, deaths from malaria are most often not individually documented, and as a result overall understanding of malaria epidemiology is inadequate. INDEPTH Network members maintain population surveillance in Health and Demographic Surveillance System sites across Africa and Asia, in which individual deaths are followed up with verbal autopsies.OBJECTIVE: To present patterns of malaria mortality determined by verbal autopsy from INDEPTH sites across Africa and Asia, comparing these findings with other relevant information on malaria in the same regions.DESIGN: From a database covering 111,910 deaths over 12,204,043 person-years in 22 sites, in which verbal autopsy data were handled according to the WHO 2012 standard and processed using the InterVA-4 model, over 6,000 deaths were attributed to malaria. The overall period covered was 1992-2012, but two-thirds of the observations related to 2006-2012. These deaths were analysed by site, time period, age group and sex to investigate epidemiological differences in malaria mortality.RESULTS: Rates of malaria mortality varied by 1:10,000 across the sites, with generally low rates in Asia (one site recording no malaria deaths over 0.5 million person-years) and some of the highest rates in West Africa (Nouna, Burkina Faso: 2.47 per 1,000 person-years). Childhood malaria mortality rates were strongly correlated with Malaria Atlas Project estimates of Plasmodium falciparum parasite rates for the same locations. Adult malaria mortality rates, while lower than corresponding childhood rates, were strongly correlated with childhood rates at the site level.CONCLUSIONS: The wide variations observed in malaria mortality, which were nevertheless consistent with various other estimates, suggest that population-based registration of deaths using verbal autopsy is a useful approach to understanding the details of malaria epidemiology.
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