| 1. |
- Currie, Thayne, et al.
(författare)
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Subaru/SCExAO First-light Direct Imaging of a Young Debris Disk around HD 36546
- 2017
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Ingår i: Astrophysical Journal Letters. - 2041-8205 .- 2041-8213. ; 836:1
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Tidskriftsartikel (refereegranskat)abstract
- We present H-band scattered light imaging of a bright debris disk around the A0 star HD 36546 obtained from the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system with data recorded by the HiCIAO camera using the vector vortex coronagraph. SCExAO traces the disk from r similar to 0.3 to r similar to 1 (34-114 au). The disk is oriented in a near east-west direction (PA similar to 75 degrees), is inclined by i similar to 70 degrees-75 degrees, and is strongly forward-scattering (g > 0.5). It is an extended disk rather than a sharp ring; a second, diffuse dust population extends from the disk's eastern side. While HD 36546 intrinsic properties are consistent with a wide age range (t similar to 1-250 Myr), its kinematics and analysis of coeval stars suggest a young age (3-10 Myr) and a possible connection to Taurus-Auriga's star formation history. SCExAO's planet-to-star contrast ratios are comparable to the first-light Gemini Planet Imager contrasts; for an age of 10 Myr, we rule out planets with masses comparable to HR 8799 b beyond a projected separation of 23 au. A massive icy planetesimal disk or an unseen super-Jovian planet at r > 20 au may explain the disk's visibility. The HD 36546 debris disk may be the youngest debris disk yet imaged, is the first newly identified object from the now-operational SCExAO extreme AO system, is ideally suited for spectroscopic follow-up with SCExAO/CHARIS in 2017, and may be a key probe of icy planet formation and planet-disk interactions.
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| 2. |
- Dey, Tushar, 1986-, et al.
(författare)
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Antibiotic Residues and Antimicrobial Resistant bacteria in the Poultry Value Chain of Two Indian States
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The poultry industry's rapid expansion has made it a significant global meat source, especially in India, which ranks as the eighth largest broiler meat producer. However, severe concerns have arisen over the increasing antibiotic resistance in low and middle-income countries, including India. This study systematically investigated the prevalence of Non-Typhoidal Salmonella (NTS) and Escherichia coli (E. coli) strains, along with their antimicrobial resistance (AMR) profiles, in poultry samples from Assam and Karnataka states in India. We found high prevalence of NTS (26%) and E. coli (53%) in various poultry samples, with substantial regional variations. Assam and Karnataka contribute differently to the overall NTS prevalence, with Karnataka bearing the highest burden (39% versus 14%). The presence of NTS and E. coli in treated water intended for watering poultry raises concerns about the effectiveness of water disinfection methods. Serovar analysis highlights the dominance of Typhimurium, Kentucky, Infantis and other serovars, some exhibiting multidrug resistance (MDR), including resistance to fluoroquinolones. The emergence of antibiotic-resistant strains, including carbapenem-resistant E. coli, presents a potential decline in treatment options. The study highlights the presence of MDR among NTS and stresses the importance of monitoring resistance profiles to devise effective antimicrobial strategies. The study underscores the necessity of collaborative efforts to combat AMR and ensure food safety, health, and wellbeing on a global scale.
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| 3. |
- Divakar, Pradeep K., et al.
(författare)
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Evolution of complex symbiotic relationships in a morphologically derived family of lichen-forming fungi
- 2015
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Ingår i: New Phytologist. - : Wiley. - 0028-646X .- 1469-8137. ; 208:4, s. 1217-1226
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Tidskriftsartikel (refereegranskat)abstract
- We studied the evolutionary history of the Parmeliaceae (Lecanoromycetes, Ascomycota), one of the largest families of lichen-forming fungi with complex and variable morphologies, also including several lichenicolous fungi. We assembled a six-locus data set including nuclear, mitochondrial and low-copy protein-coding genes from 293 operational taxonomic units (OTUs). The lichenicolous lifestyle originated independently three times in lichenized ancestors within Parmeliaceae, and a new generic name is introduced for one of these fungi. In all cases, the independent origins occurred c. 24 million yr ago. Further, we show that the Paleocene, Eocene and Oligocene were key periods when diversification of major lineages within Parmeliaceae occurred, with subsequent radiations occurring primarily during the Oligocene and Miocene. Our phylogenetic hypothesis supports the independent origin of lichenicolous fungi associated with climatic shifts at the Oligocene-Miocene boundary. Moreover, diversification bursts at different times may be crucial factors driving the diversification of Parmeliaceae. Additionally, our study provides novel insight into evolutionary relationships in this large and diverse family of lichen-forming ascomycetes.
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| 4. |
- Mann, Anita, et al.
(författare)
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Differences in DNA Condensation and Release by Lysine and Arginine Homopeptides Govern Their DNA Delivery Efficiencies
- 2011
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Ingår i: Molecular Pharmaceutics. - : American Chemical Society (ACS). - 1543-8384 .- 1543-8392. ; 8:5, s. 1729-1741
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Tidskriftsartikel (refereegranskat)abstract
- Designing of nanocarriers that can efficiently deliver therapeutic DNA payload and allow its smooth intracellular release for transgene expression is still a major constraint. The optimization of DNA nanocarriers requires thorough understanding of the chemical and structural characteristics of the vector-nucleic acid complexes and its correlation with the cellular entry, intracellular state and transfection efficiency. L-Lysine and L-arginine based cationic peptides alone or in conjugation with other vectors are known to be putative DNA delivery agents. Here we have used L-lysine and L-arginine homopeptides of three different lengths and probed their DNA condensation and release properties by using a multitude of biophysical techniques including fluorescence spectroscopy, gel electrophoresis and atomic force microscopy. Our results clearly showed that although both lysine and arginine based homopeptides condense DNA via electrostatic interactions, they follow different pattern of DNA condensation and release in vitro. While lysine homopeptides condense DNA to form both monomolecular and multimolecular complexes and show differential release of DNA in vitro depending on the peptide length, arginine homopeptides predominantly form multimolecular complexes and show complete DNA release for all peptide lengths. The cellular uptake of the complexes and their intracellular state (as observed through flow cytometry and fluorescence microscopy) seem to be controlled by the peptide chemistry. The difference in the transfection efficiency of lysine and arginine homopeptides has been rationalized in light of these observations.
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| 5. |
- Singh, Akhilender Jeet, et al.
(författare)
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Nucleation and Growth of Cu2O : Role of Potential, Electrolyte pH, and Substrate
- 2023
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Ingår i: Journal of the Electrochemical Society. - : The Electrochemical Society. - 0013-4651 .- 1945-7111. ; 170:7
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Tidskriftsartikel (refereegranskat)abstract
- The nucleation and growth mechanism of functional oxides has a direct bearing on the structural and electronic properties of the deposit. We study the effect of electrolyte pH and deposition potential on the nucleation and growth of Cu2O on polycrystalline metal oxide (FTO) & metal (Au) substrates. Modelling of the recorded current-time transients indicates that both instantaneous and progressive nucleation occur with growth limited by diffusion or lattice incorporation of electro-active species or both. The preferred orientation of Cu2O shows a strong dependence on electrolyte pH. The films are (100) oriented on both substrates at pH 9 except at high applied potential on FTO where the orientation changes to (111). Interestingly, irrelevant of electrolyte pH, the grain size of Cu2O decreases with potential on FTO whereas it increases on Au substrates. We attribute this to a difference in the number of active nucleation sites between the two substrates. The nucleation and growth at pH 12 is observed to be dependent both on diffusion and lattice incorporation of electro-active species. Additionally, the films are primarily (111) oriented on both substrates, which is correlated to the availability of OH- ions.
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| 6. |
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