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Comparative modelling of the crystal-field parameters (CFPs), CF energy levels, and effective spin-Hamiltonian parameters of the ground state 4A2g of the Cr3+ dopant ions in Y2Ti2O7 and Y2Sn2O7 is carried out.

To assess the pattern of climatic evolution during the late Miocene to early Pleistocene in the largest fluvio-deltaic sedimentary system on the Earth, the Bengal Basin (BB), a quantitative palaeoclimatic reconstruction was made, based on 20 fossil wood floras. Those floras show that moisture-loving taxa have decreased considerably since the Miocene, especially at the western margin of the basin. A quantitative reconstruction of climate parameters reveals that the late Miocene−early Pliocene was warmer and wetter than now, yet with spatial variability. Seasonality of temperature was low in the basin and subsequently increased during the late Pliocene−early Pleistocene. Monsoon intensity was weaker during the interval from the late Miocene to early Pleistocene than the present day. A comparison of the retrieved data with some earlier records from sites either influenced by Indian summer monsoon (ISM) or East Asian summer monsoon (EASM) or both, the two branches of the Asian summer monsoon (AM) provide insights into the temporal and spatial patterns of climate evolution in southern Asia during the late Neogene–Quaternary transition. In general, a drop in temperature and a weakening in ISM strength since the early Pleistocene correlate with the global cooling trend, though with spatial differences.

Aim: To determine the correlation between Lip prints, Palm prints and ABO Blood Groups which may help in determining sexual dimorphism and forensic identification. Materials and Methods: 100 healthy subjects, 18 to 25 years of age and a native of Mangalore population were randomly selected. Lip prints and palm prints were recorded using the manual techniques for each subject along with their authentic blood group report. Lip prints and palm prints were recorded according to classifications given by Suzuki and Tsuchihashi, and Wu et al, respectively. Results: The most common lip and palm pattern recorded was Type II and Category V respectively in both the genders. The most common blood groups in both genders was B+. Correlation between three parameters was obtained by Pearson correlation statistical analysis. Conclusion: The lip prints and palm prints of an individual have never been similar and they tend to remain same from birth till death. This study was an effort made by us to associate lip prints, palm prints and blood groups of an individual, to aid in forensic identification.

Artificial intelligence (AI) and its applications have assisted in many areas of COVID-19 and are playing a very crucial role in its management. The present article mentions usefulness of Artificial intelligence in detection and management of cases of COVID- 19.

Cleidocranial dysplasia (CCD) is a rare inherited disorder affecting dental and skeletal tissues. CCD usually has an autosomal dominant pattern of inheritance and common clinical features seen are aplastic or hypoplastic clavicles, late closure of fontanelle, open skull sutures, retained deciduous teeth, late eruption of permanent teeth and presence of multiple impacted supernumerary teeth. Here, we present a case of CCD in a female patient with positive family history. The diagnosis was confirmed clinically and radiographically. The newer radiographic advancement, CBCT was used to validate the radiographic findings.

Keloids are benign fibroproliferative growth seen on the skin usually secondary to trauma. They are scar tissues that project above the skin surface and may be tender or pruritic. They cause functional and aesthetic discomfort to the patient. This is a case report of a 34 year old woman who was diagnosed as a case of keloid of the left auricle and treated surgically. Keloids have a high degree of recurrence even after treatment. It is crucial to differentiate keloids from hypertrophic scars and treat them accordingly.

Background: The present study aimed to report occurrence of radix entomolaris in mandibular first molar. Materials and methods: The present study was conducted on 428 mandibular first molar in 280 patients. The incidence of RE and comparison of the occurrence between males and females and between the right and left sides of the mandible were recorded. Results: Out of 210 molars in males, 10 (4.76%) had and out of 218 molars in females, 8 (3.66%) had Radix Entomolaris. The difference was significant (P< 0.05). 12 Radix Entomolaris were seen in 238 left molars and 6 were seen in 190 right molars. The difference was significant (P< 0.05). Conclusion: Authors found that Radix Entomolaris was commonly seen in males. Left side exhibited more Radix Entomolaris as compared to right side.

We report here the occurrence of petrified wood resembling the modern dipterocarp Dryobalanops from the Neogene (late Miocene) of the Bengal Basin, India. We have determined the taxonomic position ...

Silicified fossil legume woods of Cynometroxylon Chowdhury & Ghosh collected from the Neogene (late Miocene) sediments of the Bengal Basin, eastern India, exhibit fungal decay seldom found in the fossil record. The wood possesses numerous perforate areas on the surface that seem to be the result of extensive fungal activity. In transverse section, the decayed areas (pockets) appear irregular to ellipsoidal in outline; in longitudinal section these areas of disrupted tissue are somewhat spindle-shaped. Individual pockets are randomly scattered throughout the secondary xylem or are restricted to a narrow zone. The aforesaid patterns of decay in fossil wood show similarities with that of white rot decay commonly produced by higher fungi, specifically basidiomycetes and ascomycetes. The host fossil wood harbors abundant ramifying and septate fungal hyphae with knob like swellings similar to pseudoclamps in basidiomycetes, and three-celled conidia-like reproductive structures. This record expands our current knowledge of wood decaying fungi-host plant interaction in the Neogene tropical forests of Peninsular India.

Endodontics is the branch of dentistry in which radiology plays a critical indispensable role. Radiology illuminates what otherwise would be dark and hidden zones and allows the dentists to visualize areas not accessible by other diagnostic means. It is the use of oral radiographs which enables visualization of the bone around the apices of the teeth, as well as the results of the root canal treatments, and as such it has allowed turning endodontics into a scientific professional entity.

Fob1 protein plays an important role in aging and maintains genomic stability by avoiding clashes between the replication and transcription machinery. It facilitates polar arrest by binding to replication fork barrier (RFB) sites, present within the nontranscribed spacer region of the ribosomal DNA. Here, we investigate the mechanism of unidirectional arrest by creating multiple prosthetic forks within the RFB, with fluorescent adenine analogue 2-aminopurine incorporated site-specifically in both the "permissible" and "nonpermissible" directions. The motional dynamics of the RFB-Fob1 complexes analyzed by fluorescence lifetime and fluorescence anisotropy decay kinetics shows that Fob1 adopts a clamp-lock model of arrest and causes stronger perturbation with the bases in the double-stranded region of the nonpermissible-directed forks over those of the permissible directed ones, thereby creating a polar barrier. Corroborative thermal melting studies reveal a skewed distribution of GC content within the RFB sequence that potentially assists in Fob1-mediated arrest.

Tetracycline repressors (TetRs) modulate multidrug efflux pathways in several pathogenic bacteria. In Streptomyces, they additionally regulate secondary metabolic pathways like antibiotic production. For instance, in the antibiotic producer Streptomyces fradiae, a layered network of TetRs regulates the levels of the commercially important antibiotic tylosin, with TylP occupying the top of this cascading network. TetRs exist in two functional states, the DNA-bound and the ligand-bound form, which are allosterically regulated. Here, to develop deeper insights into the factors that govern allostery, the crystal structure of TylP was solved to a resolution of 2.3 Å. The structure revealed that TylP possesses several unique features; notably, it harbors a unique C-terminal helix-loop extension that spans the entire length of the structure. This anchor connects the DNA-binding domain (DBD) with the ligand-binding domain (LBD) via a mix of positively charged and hydrogen-bonding interactions. Supporting EMSA studies with a series of ΔC truncated versions show that a systematic deletion of this region results in complete loss of DNA binding. The structure additionally revealed that TylP is markedly different in the orientation of its DBD and LBD architecture and the dimeric geometry from its hypothesized Streptomyces homologue CprB, which is a γ-butyrolactone regulator. Rather, TylP is closer in structural design to macrolide-binding TetRs found in pathogens. Supporting molecular dynamic studies suggested that TylP binds a macrolide intermediate in the tylosin pathway. Collectively, the structure along with corroborating biochemical studies provided insights into the novel mode of regulation of TetRs in antibiotic-producing organisms.

Tetracycline repressors (TetRs) modulate multidrug efflux pathways in several pathogenic bacteria. In Streptomyces, they additionally regulate secondary metabolic pathways like antibiotic production. For instance, in the antibiotic producer Streptomyces fradiae, a layered network of TetRs regulates the levels of the commercially important antibiotic tylosin, with TylP occupying the top of this cascading network. TetRs exist in two functional states, the DNA-bound and the ligand-bound form, which are allosterically regulated. Here, to develop deeper insights into the factors that govern allostery, the crystal structure of TylP was solved to a resolution of 2.3 angstrom. The structure revealed that TylP possesses several unique features; notably, it harbors a unique C-terminal helix-loop extension that spans the entire length of the structure. This anchor connects the DNA-binding domain (DBD) with the ligand-binding domain (LBD) via a mix of positively charged and hydrogen-bonding interactions. Supporting EMSA studies with a series of Delta C truncated versions show that a systematic deletion of this region results in complete loss of DNA binding. The structure additionally revealed that TylP is markedly different in the orientation of its DBD and LBD architecture and the dimeric geometry from its hypothesized Streptomyces homologue CprB, which is a gamma-butyrolactone regulator. Rather, TylP is closer in structural design to macrolide-binding TetRs found in pathogens. Supporting molecular dynamic studies suggested that TylP binds a macrolide intermediate in the tylosin pathway. Collectively, the structure along with corroborating biochemical studies provided insights into the novel mode of regulation of TetRs in antibiotic-producing organisms.

Background: The gamma-butyrolactone (GBL) binding transcription factors in Streptomyces species are known for their involvement in quorum sensing where they control the expression of various genes initiating secondary metabolic pathways. The structurally characterized member of this family CprB from Streptomyces coelicolor had earlier been demonstrated to bind a multitude of sequences containing a specific binding signature. Though structural breakthrough has been obtained for its complex with a consensus DNA sequence there is, however a dearth of information regarding the overall and site specific dynamics of protein-DNA interaction. Methods: To delineate the effect of CprB on the bound DNA, changes in motional dynamics of the fluorescent probe 2-aminopurine were monitored at three conserved base positions (5th, 12th and 23rd) for two DNA sequences: the consensus and the biologically relevant cognate element, on complex formation. Results: The changes in lifetime and generalized order parameter revealed a similarity in the binding pattern of the protein to both sequences with greater dynamic restriction at the end positions, 5th and 23rd, as compared to the middle 12th position. Also differences within this pattern demonstrated the influence of even small changes in sequence on protein interactions. Conclusions: Here the study of motional dynamics was instrumental in establishing a structural footprint for the cognate DNA sequence and explaining the dynamics for the consensus DNA from structural correspondence. General significance: Motional dynamics can be a powerful tool to efficiently study the mode of DNA binding to proteins that interact differentially with a plethora of DNA sequences, even in the absence of structural breakthrough. (C) 2015 Elsevier B.V. All rights reserved.

Quorum sensing is a cell density dependent phenomenon that utilizes small molecule inducers like gamma-butyrolactones (GBLs) and their receptor proteins for adaptation to the environment. The cognate GBLs that bind to several of this GBL receptor family of proteins remain elusive. Here, using CprB protein from Streptomyces coelicolor A3(2) as a model system, we devise a method suited for ligand screening that would be applicable to the entire family of GBL receptors. Docking studies were performed to confirm the identity of the ligand binding pocket, and it was ascertained that the common gamma-butyrolactone moiety interacts with the conserved tryptophan residue (W127) residing in the ligand binding pocket. The presence of W127 in the cavity was exploited to monitor its fluorescence quenching on the addition of two chemically synthesized GBLs. Analysis of the data with both the native and W185L, mutant versions of the protein confirmed that the compounds used as quenchers reside in the ligand binding pocket. Furthermore, fluorescence lifetime and potassium iodide (KI) quenching studies established that the quenching is static in nature and that the tryptophan residue is buried and inaccessible to surface quenchers. Additionally, a combination of concentration dependent fluorescence quenching and dynamic light scattering experiments revealed that the binding properties of the protein are concentration dependent and it was concluded that the most efficient binding of the ligand is evoked by working at the lowest concentration of protein, providing a sufficient signal, where the aggregation effects are negligible.

Guanine deaminases (GDs) are important enzymes involved in purine metabolism as well as nucleotide anabolism pathways that exhibit a high degree of fidelity. Here, the structural basis of the substrate specificity of GDs was investigated by determining a series of Xray structures of NE0047 (GD from Nitrosomonas europaea) with nucleobase analogues and nucleosides. The structures demonstrated that the interactions in the GD active site are tailor-made to accommodate only guanine and any substitutions in the purine ring or introduction of a pyrimidine ring results in rearrangement of the bases in a catalytically unfavorable orientation, away from the proton shuttling.residue E143. In addition, X-ray structural studies performed on cytidine revealed that although it binds in an optimal conformation, its deamination does not occur because of the inability of the enzyme to orchestrate the closure of the catalytically important C-terminal loop (residues 181-189). Isothermal calorimetry measurements established that nucleoside moieties also disrupt the sequential mode of ligand binding, thereby abrogating all intersubunit communication. Intriguingly, it was recently discovered that GDs can also serve as endogenous ammeline deaminases, although it is structurally nonhomologous with guanine. To understand the mechanism of dual-substrate specificity, the structure of NE0047 in complex with ammeline was determined to a resolution of 2.7 angstrom. The structure revealed that ammeline not only fits in the active site in a catalytically favorable orientation but also allows for closure of the C-terminal loop.

Quorum sensing is a cell density dependent phenomenon that utilizes inducers like γ-butyrolactones (GBLs) and their receptor proteins in Streptomyces species to control expression of a plethora of genes initiating antibiotic production and other secondary metabolic pathways. The receptor proteins regulate by binding to the DNA in the promoter regions of genes; release from the DNA takes place on binding to their specific GBL molecules, initiating the expression of the downstream genes.Several cognate GBLs binding to the GBL receptor family of proteins remain elusive. Here, using the only structurally characterised member of this family, CprB from Streptomycescoelicolor A3(2) as a model system, we suggest tryptophan quenching as a method for ligand screening, for the family. The intrinsic fluorophore tryptophan (W127) is a conserved residue in the family residing within the ligand binding pocket of CprB. Docking studies show interaction of GBLs with W127 and has been identified as the cause of fluorescence quenching observed on administration of two chemically synthesized GBLs (http://dx.doi.org/10.1021/jp503589h)CprB is also known to specifically bind various promoter sequences. Though structural breakthrough has been achieved for the complex with a consensus sequence, there is dearth of information on the mode of binding to the others. To delineate the same, motional dynamics of 2-aminopurine (2-AP) has been monitored after its incorporation at different positions within the consensus sequence and a biologically relevant cognate sequence. Comparing the dynamics restriction of 2-AP across the two sequences has helped reveal a signature pattern of DNA binding by CprB. The study highlights how the technique can be a powerful tool to understand the mode of binding even in the absence of structural breakthrough (Manuscript under review).