Low geomagnetic field strength during End-Cretaceous Deccan volcanism and whole mantle convection.

Knowledge about long-term variation of the geomagnetic dipole field remains in its nascent stage because of the paucity of reliable experimental data over geological periods. Here, we present the first robust experimental data from the largest Cretaceous flood basalt province on Earth, the ~65-66 Ma Deccan basalt within a thick (1250 m) unbiased stratigraphic section down to the basement, recovered from a drill hole of the Koyna Deep Scientific Drilling Project in the Western Ghats, India. Critical analysis of the result along with similar results of the Cretaceous age find that (i) the dipole moment during the end Cretaceous Deccan eruption is the lowest in whole of Cretaceous (ii) dipole moment at the onset/termination of the Cretaceous Normal Superchron is apparently lower relative to that in mid-superchron, however, such differences cannot be deciphered in shorter polarities probably because of insufficient time to develop recognizable variations (iii) inverse relation between dipole moment and reversal rate is lacking and (iv) a cause and effect relation between core-mantle boundary heat flux and low dipole moment that appears to be the principle governing factor in forming the Large Igneous Provinces on the surface of earth.

Mechanism of rift flank uplift and escarpment formation evidenced by Western Ghats, India.

The Western Ghats is one of the largest escarpments on earth, containing Reunion plume derived Deccan Traps, it is an excellent example to probe epeirogenic uplift, extension and subsidence in volcanic continental margins. The most continuous unbiased stratigraphic section of basalt down to the basement within a 1250 m drill hole of the Continental Scientific Deep Drilling Project is a valuable resource to investigate the above aspects. The flows across the entire drill core are geologically subaerial in character with basement exposed ~300 m below the mean sea level; they clearly display more evolved compositions from primary melts of mantle in terms of petrology, and only a single geomagnetic polarity transition in palaeomagnetic data. These results, combined with existing geological and geophysical data, constitute a multi-method approach that demonstrates (a) igneous underplating caused uplift prior to frequently suggested flexural isostasy (b) plume impact and eruption are near-simultaneous and extension/rifting essentially followed soon after volcanism and (c) lithosphere beneath the continental margin, while returning to normal temperatures following the Seychelles-India breakup, experienced thermal collapse and subsidence causing slumping of basalt basement below sea level.

Crystal structure of poly[[di-µ3-acetato-tetra-aqua-bis-(µ2-cyclo-hexane-1,4-di-carboxyl-ato)dilanth-an-um(III)] dihydrate].

The title compound, {[La2(CH3COO)2(C8H10O4)2(H2O)4]·2H2O} n or [La2(ac)2(e,a-cis-1,4-chdc)2(H2O)4]·2H2O, where ac is acetate and 1,4-chdc is cyclo-hexane-1,4-di-carboxyl-ate anion, is a binuclear lanthanum(III) complex. Each metal atom is deca-coordinated by four O atoms from two distinct 1,4-chdc2- ligands, four O atoms from three acetate groups and two O atoms from coordinated water mol-ecules to form a distorted bicapped square-anti-prismatic geometry. Two non-coordinated water mol-ecules are also present in the formula unit. The most remarkable feature of this compound is that it possesses a only cis conformation for cyclo-hexane-1,4-di-carb-oxy-lic acid, although the raw material consists of a mixture of cis and trans isomers. The µ3-η2:η2 coordination mode of the bridging acetate group and the flexible di-carboxyl-ate fragments of 1,4-chdc2- results in the formation of infinite two-dimensional lanthanide-carboxyl-ate layers within the crystal structure. The directionality of strong inter-molecular O-H⋯O and weak C-H⋯O inter-actions provides robustness to the layers, which leads to the construction of a three-dimensional supra-molecular network. The crystal studied was refined as a two-component twin.

Knowledge and Pattern of Antibiotic and Non Narcotic Analgesic Prescription for Pulpal and Periapical Pathologies- A Survey among Dentists.

AIM: The objective was to assess the knowledge and pattern of antibiotic and non narcotic analgesic prescription for pulpal and periapical pathologies among dentists, registered with IDA, in and around Hyderabad. MATERIALS AND METHODS: Cross-sectional survey was conducted from January 2014 to February 2014 in and around Hyderabad, Andhra Pradesh, India. A questionnaire for this cross-sectional survey was designed for evaluating the knowledge and patterns of antibiotic and non narcotic analgesic prescription for pulpal and periapical pathologies. It included some demographic information, questions regarding clinical and non clinical factors, type of antibiotics and non narcotics analgesics prescribed were recorded. Data was computed and analysed using SPSS software. Descriptive statistics was performed. RESULTS: The response rate for the study was 85%, 51.4% being males and 53.9% were pursuing post graduation. Of the respondents, 44.3% would prescribe medication with elevated body temperatures and evidence of systemic involvement, while 42.8% would prescribe medication for non clinical factors such as unsure of diagnosis. Necrotic pulp with acute apical periodontitis with swelling present and mod/severe preoperative symptoms was the most common condition identified for antibiotic therapy (56.4%). The first antibiotic of choice in patients with no medical allergies is amoxicillin, followed by amoxicillin and metronidazole. The first antibiotic of choice in case of allergic to penicillin was erythromycin. 55.1% and 37.3% would not prescribe antibiotic and analgesic after Root canal treatment respectively. The most commonly prescribed NSAID is Diclofenac (51.1%). Factors influencing the choice of analgesics among respondents is severity of pain (61.4%). 31.7% remained informed of current prophylactic practices through pharmaceutical companies followed by university training sessions and scientific societies (30.7%). CONCLUSION: The results of the present survey have demonstrated a lack of uniformity among the dental practitioners. All the clinicians should make themselves aware of the current guidelines available, to ensure highest degree of patient care.

Probing cellular mechanoadaptation using cell-substrate de-adhesion dynamics: experiments and model.

Physical properties of the extracellular matrix (ECM) are known to regulate cellular processes ranging from spreading to differentiation, with alterations in cell phenotype closely associated with changes in physical properties of cells themselves. When plated on substrates of varying stiffness, fibroblasts have been shown to exhibit stiffness matching property, wherein cell cortical stiffness increases in proportion to substrate stiffness up to 5 kPa, and subsequently saturates. Similar mechanoadaptation responses have also been observed in other cell types. Trypsin de-adhesion represents a simple experimental framework for probing the contractile mechanics of adherent cells, with de-adhesion timescales shown to scale inversely with cortical stiffness values. In this study, we combine experiments and computation in deciphering the influence of substrate properties in regulating de-adhesion dynamics of adherent cells. We first show that NIH 3T3 fibroblasts cultured on collagen-coated polyacrylamide hydrogels de-adhere faster on stiffer substrates. Using a simple computational model, we qualitatively show how substrate stiffness and cell-substrate bond breakage rate collectively influence de-adhesion timescales, and also obtain analytical expressions of de-adhesion timescales in certain regimes of the parameter space. Finally, by comparing stiffness-dependent experimental and computational de-adhesion responses, we show that faster de-adhesion on stiffer substrates arises due to force-dependent breakage of cell-matrix adhesions. In addition to illustrating the utility of employing trypsin de-adhesion as a biophysical tool for probing mechanoadaptation, our computational results highlight the collective interplay of substrate properties and bond breakage rate in setting de-adhesion timescales.

A study to evaluate the frequency and association of various mucosal conditions among geriatric patients.

UNLABELLED: Geriatric dentistry or gerodontics is the delivery of dental care to older adults involving the diagnosis, prevention and treatment of problems associated with normal aging and age-related diseases as part of an interdisciplinary team with other health care professionals. AIM: To evaluate the oral mucosal status in the elderly population of different age group and fnd out the association of age, gender and denture with oral mucosal disorders. MATERIALS AND METHODS: The study sample consisted of 570 geriatric persons concentrating mainly on the oral mucosal changes or lesions occurring in the geriatric population. Individuals those are aged above 60 years were selected, and all the examined geriatric persons were categorized into 3 age groups to fnd out the association of oral mucosal lesions in each group. Group I-60 to 65 years, Group II-66 to 70 years, Group III-71 and above years. RESULTS: The sample of 570 elderly patients included 279 (48.95%) men and 291 (51.05%) women in three age groups: 61 to 65 years (40.35%), 66 to 70 years (31.05%), and 71 years and older (28.60%). The sample included 254 (44.56%) dentate patients, 205 (35.96%) denture wearers (partial and complete denture wearers) and 111 (19.47%) edentulous persons who lacked dentures in both the jaws. Almost half of the patients examined (48%) had one or more oral mucosal lesions. The 48% of the patients who presented with oral mucosal lesions, twenty fve different oral mucosal conditions were identifed and the three most common fndings were lingual varices (13.68%), denture induced infammatory fbrous hyperplasia (4.21%), squamous cell carcinoma (4.21%). There was some differences in the distribution of oral mucosal condition among the sexes. Leukoplakia and dysplasia were signifcantly associated with men (p < 0.001) whereas the association of fbroma and lichen planus with women were signifcant (p < 0.001). CONCLUSION: In our study it was found that patients in groups II and III had more prevalence of oral mucosal disorders. Lingual varices, oral squamous cell carcinoma, fbroma and denture induced infammatory fbrous hyperplasia were more commonly associated with the geriatric patients. The oral lesions (fbroma and lichen planus) were strongly associated with women while leukoplakia was strongly associated with men. Ageing is an important factor that can infuence the occurrence of mucosal lesions and with age the oral mucosa becomes more permeable to noxious substances and more vulnerable to external carcinogens.