ABSTRACT
Three novel strains in Calotrichaceae from tropical habitats were isolated and characterized with regard to their morphology, phylogenetic placement, and secondary structures of conserved domains in the 16S-23S internal transcribed spacer (ITS). The strains fell into two clades formerly identified as Calothrix from freshwater and brackish habitats. Based on both morphology and ecology, they differed from the type species of Calothrix, C. confervicola, which is marine, has wide trichomes with short cells, and narrows abruptly to a hyaline hair. The first clade grouped species with heteropolar filaments widened at the base and narrowed gradually toward the apex but not ending in a hair, with basal heterocytes that are formed in series as the apically placed heterocytes senesce; this clade is being named Fulbrightiella gen. nov., with two named species, F. bharadwajae sp. nov. and F. oahuensis sp. nov. The second clade was comprised of a single species with isopolar trichomes that are untapering as hormogonia, but which widen midfilament and taper toward both ends following growth. These trichomes develop pairs of heterocyte mid-filament, causing fragmentation into heteropolar trichomes with basal heterocytes and ends that taper, but not to a hair. This clade consists of a single species at present, Sherwoodiella mauiensis. With this action, four clades in the Calotrichaceae have been named: Macrochaete, Dulcicalothrix, Fulbrightiella, and Sherwoodiella. Calothrix sensu stricto is truly marine, morphologically distinct, and unsequenced; finding and sequencing the generitype for Calothrix remains as the most important and unfinished task in the revision of the Calotrichaceae.
Subject(s)
Cyanobacteria , Ecosystem , Phylogeny , RNA, Ribosomal, 16S , DNA, Bacterial , Cyanobacteria/genetics , Sequence Analysis, DNAABSTRACT
During reconstructive interventions in patients presenting with severe post-burn mento-sternal scar contracture, securing the airway forms a critical part of management. Extreme contracture is more likely to develop in patients who have had thoracic burns with ascending involvement of the neck and mandibular region. When cervical hyperextension and elevation of the mandible are impeded, post-burn contracture of the neck might render endotracheal intubation difficult. The development of rigid scar tissue that distorts the laryngeal and mandibular anatomy, or the development of microstomia following scar tissue retraction in facial burns, may make alternative approaches to direct laryngoscopy challenging. In patients with healed neck burns, intubation difficulties should be anticipated, and equipment for aiding intubation should be kept ready. Furthermore, a surgeon must be present throughout anesthesia induction in case an emergency neck release is required. Although the role of awake fiberoptic intubation has been well established in the general population, it is yet to be assessed in patients with burns. In this report, we present a case of successfully managed post-burn contracture that was planned for awake fiberoptic intubation.
ABSTRACT
In the following study, an attempt is made for crop classification of rainy season through analyzing time-series Sentinel-1 SAR data of May 2020 to September 2020. The SVIDP index derived from dual-pol (VV and VH) bands consisting of NRPB ([Formula: see text]), DPDD [Formula: see text]), IDPDD ([Formula: see text]), and VDDPI [Formula: see text] ratios are utilized for discriminating inter-vegetative boundaries of crop pixels. This study was conducted near Karnal city region, Karnal district, Haryana, India. The Sentinel-1 data has the capability to penetrate thick cloud cover and provide high revisit frequency data for rain-fed crops. Obtained classification achieved higher accuracy in both RF (93.77%) and SVM (93.50%) classifiers. Obtained linear regression statistics of mean raster imagery reveals that IDPDD index is much sensitive to other crop which has highest standard deviations in σvh° and σvv° bands throughout the period, and high R2 with σvh° (0.70), VV (0.58), NRPB (0.693), and DPDD (0.697) indices. In contrast to this, IDPDD index has least correlation (< 0.289) with σvh°, σvv°, EVI 2, NRPB, and DPDD indices for water body which has smooth surface and lowest SAR backscattering with minimum standard deviations in the same period.
Subject(s)
Crops, Agricultural , Environmental Monitoring , Seasons , IndiaABSTRACT
A dark-coloured thin film of cyanobacteria growing on the bottom of a submerged stone was isolated from Basantgarh village in Udhampur district, Jammu and Kashmir, India. The isolated strain (designated 19C-PST) was characterized using a polyphasic approach. The strain exhibited typical Nostoc-like morphology with a characteristic feature of having heterocytes in series. The 16S rRNA gene phylogeny placed the strain at a well-supported and distinct node. Notably, the recently described genus, Amazonocrinis, on the addition of more 16S rRNA gene sequences, reflected a critical split, which proved to be stable and well supported in all phylogenetic analyses of the 16S rRNA gene. Interestingly, Amazonocrinis nigriterrae CENA67T (type species of the genus) clustered together with our strain 19C-PST in the 16S rRNA gene phylogenetic analysis while the rest of the members of the genus Amazonocrinis were placed at a separate and distant node. This clearly indicated that strain 19C-PST is a member of Amazonocrinis sensu stricto. However, the results of phylogenetic analysis of ITS sequences only, in strains purported to belong to Amazonocrinis did not agree with the 16S rRNA gene results and placed our strain 19C-PST in a sister clade to three strains that have not yet been speciated, UHCC 0702, NIES-4103 and SA22, with A. nigriterrae falling into a separate clade. Further, folded secondary structures of the D1-D1', V2, BoxB and V3 helices of strain 19C-PST were found to be significantly different from those of all the phylogenetically related taxa. The study revealed an interesting case where low taxon sampling and phylogenomic interpretations came across as points of attention in cyanobacterial taxonomy. Based on the morphological, phylogenetic, 16S-23S ITS secondary structure analyses, we describe our strain as Amazonocrinis malviyae sp. nov. in accordance with the International Code of Nomenclature for algae, fungi and plants. This work also illuminates the need for further research to resolve the taxonomic discrepancies among Amazonocrinis strains.
Subject(s)
Fatty Acids , Nostoc , Phylogeny , RNA, Ribosomal, 16S/genetics , DNA, Bacterial/genetics , Sequence Analysis, DNA , Bacterial Typing Techniques , Base Composition , Fatty Acids/chemistry , IndiaABSTRACT
A freshwater dwelling cyanobacterium (strain MKW3) was isolated from a sample collected from a water logged sugarcane field located in Malkapur, Karad, Maharashtra, India, and was characterized using a polyphasic approach. In the 16S rRNA gene phylogenetic analysis, strain MKW3 clustered with two misidentified strains-Nostoc sp. CENA239 and Calothrix sp. NIES2100. The phylogenetically related members included strains identified as Nostoc, Aulosira, Calothrix, Tolypothrix, Camptylonemopsis and Microchaete. The phylogenetic and the morphological analysis of the strain MKW3 indicated that it does not belong to any of the above mentioned genera. Furthermore, the 16S-23S ITS secondary structure analysis provided clear evidence indicating that strain MKW3 is different from Nostoc sp. CENA239 and Calothrix sp. NIES2100. Based on the morphological, phylogenetic and 16S-23S ITS secondary structure analysis we describe our strain as Constrictifilum karadense gen. et sp. nov. in accordance with the International Code of Nomenclature for algae, fungi and plants.
Subject(s)
Cyanobacteria/classification , Phylogeny , Cyanobacteria/cytology , Cyanobacteria/genetics , DNA, Bacterial/genetics , DNA, Ribosomal Spacer/chemistry , Fresh Water/microbiology , India , Nucleic Acid Conformation , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Species SpecificityABSTRACT
The order Nostocales is represented by morphologically diverse forms with respect to the branching patterns and polarity of the filaments. With growing understanding of taxonomy and systematics, members of the order Nostocales have also undergone multiple taxonomic revisions. The last decade has seen a surge in the description of new genera and families within the order Nostocales. In this study, we discuss the taxonomic status of all the newly described and reclassified taxa of some of the prominent morphological forms within the order Nostocales by constructing comprehensive phylogenetic trees. Further, we propose certain strategies that would contribute to resolving the taxonomic complexities arising due to inadequate taxon sampling.
Subject(s)
Cyanobacteria/classification , Phylogeny , Cyanobacteria/cytology , Cyanobacteria/geneticsABSTRACT
Soil inhabiting true branching heterocytous cyanobacterium strain SNS 3 with T-type branching was collected from the campus of Banaras Hindu University, India and characterized using the polyphasic approach. Morphological observations showed the presence of akinetes (in chain), hormogonia and monocytes. Physiological characterization of strain SNS 3 showed high content of carotenoid in comparison to chlorophyll a content along with also exhibiting a higher C/N ratio in the nitrogen deficient BG110 medium. 16S rRNA gene sequencing and subsequent phylogeny indicated strong clustering of the strain SNS 3 within the Westiellopsis clade. Folded secondary structures of the ITS region showed visible differences in the D1-D1' and BoxB helix of the strain SNS 3. The polyphasic approach indicated the strain SNS 3 as a new member of the genus Westiellopsis with the name proposed being Westiellopsis akinetica sp. nov. on the basis of the International Code of Nomenclature for Algae, Fungi and Plants. Intense phylogenetic evaluation of the entire true-branched heterocytous clade indicated the need for more revisionary attempts for demarcating the sensu stricto clades along with highlighting the scope for further taxonomic revisions in the future.
Subject(s)
Cyanobacteria/classification , Phylogeny , Soil Microbiology , Bacterial Typing Techniques , Cyanobacteria/physiology , DNA, Bacterial/genetics , India , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNAABSTRACT
Three heterocytous cyanobacterial strains were isolated from different habitats of Central India, and initial morphological studies indicated them to be members of the genus Nostoc or other closely related genera. Subsequent studies using morphological, ecological, molecular and phylogenetic methods indicated the three strains to be new members of the genera Aliinostoc and Desmonostoc. Folding of the D1-D1' helix of the ITS region clearly differentiated the three strains from the other closely related strains, thus providing final indications of the strains being different and new additions to the genera Aliinostoc and Desmonostoc. In accordance with the International Code of Nomenclature for algae, fungi and plants, we establish three new species: Aliinostoc tiwarii sp. nov, Aliinostoc soli sp. nov. and Desmonostoc magnisporum sp. nov. along with reclassifying Nostoc punensis as Desmonostoc punense comb. nov.