An interesting note on floating corals.

The floating stone on a closer examination reveals that it is a coral. Corals of the genus Favia, Platygyra etc. are kept floating in a tank filled with water. The scientific explanations of the floating corals are examined. The scientific significance of floating coral are here described

Evaluation of shear bond strength of a composite resin to white mineral trioxide aggregate with three different bonding systemsa: an in vitro analysis

Background: Mineral trioxide aggregate (MTA) is a biomaterial that has been investigated for endodontic applications. With the increased use of MTA in pulp capping, pulpotomy, perforation repair, apexification and obturation, the material that would be placed over MTA as a final restoration is an important matter. As composite resins are one of the most widely used final restorative materials, this study was conducted to evaluate the shear bond strength of a composite resin to white mineral trioxide aggregate (WMTA) using three different bonding systems namely the two-step etch and rinse adhesive, the self-etching primer and the All-in-one system. Material and Methods: Forty five specimens of white MTA (Angelus) were prepared and randomly divided into three groups of 15 specimens each depending on the bonding systems used respectively. In Group A, a Two-step etch and rinse adhesive or ‘total-etch adhesive’, Adper Single Bond 2 (3M/ESPE) and Filtek Z350 (3M ESPE, St Paul, MN) were placed over WMTA. In group B, a Two-step self-etching primer system, Clearfil SE Bond (Kuraray, Medical Inc) and Filtek Z350 were used. In Group C, an All-in-one system, G Bond (GC corporation, Tokyo, Japan) and Filtek Z350 were used. The shear bond strength was measured for all the specimens. The data obtained was subjected to One way Analysis of Variance (ANOVA) and Scheffe’s post hoc test. Results: The results suggested that the Two-step etch and rinse adhesive when used to bond a composite resin to white MTA gave better bond strength values and the All-in-one exhibited the least bond strength values. Conclusions: The placement of composite used with a Two-step etch and rinse adhesive over WMTA as a final restoration may be appropriate

Management of a permanent maxillary first molar with two disto buccal canals with the aid of spiral computed tomography: a case report

Human molars show considerable anatomic variations with respect to number of roots and root canals. The most common form of the permanent maxillary first molar has three roots and four canals, two mesiobuccal canals and one distobuccal and palatal canal each. 98.3% of maxillary first molar have been reported to have a single distobuccal canal. Two canals were found only 1.7% of the time, hence showing the second disto buccal canal to being a rare occurrence. Conventionally radiographs are used to determine root canal anatomy, which is a 2- dimensional representation of a 3-dimensional object. Diagnostic methods like spiral computerized tomography where a 3 dimensional data is acquired are useful to determine complex morphology. This case report presents the management of a maxillary first molar with two disto buccal root canals confirmed with the aid of computed tomography along with the conventional radiographic method. Computed Tomography scan slices revealed two separate distobuccal canals at the coronal 3rd of the root. The second distobuccal canal was missing in the middle and apical 3rd indicating; it might have joined the distobuccal canal at the middle 3rd area

Luminous Red Galaxies: Selection and classification by combining optical and infrared photometry

We describe a new method of combining optical and infrared photometry to select Luminous Red Galaxies (LRGs) at redshifts $z > 0.6$. We explore this technique using a combination of optical photometry from CFHTLS and HST, infrared photometry from the WISE satellite, and spectroscopic or photometric redshifts from the DEEP2 Galaxy Redshift Survey or COSMOS. We present a variety of methods for testing the success of our selection, and present methods for optimization given a set of rest-frame color and redshift requirements. We have tested this selection in two different regions of the sky, the COSMOS and Extended Groth Strip (EGS) fields, to reduce the effect of cosmic/sample variance. We have used these methods to assemble large samples of LRGs for two different ancillary programs as a part of the SDSS-III/ BOSS spectroscopic survey. This technique is now being used to select $\sim$600,000 LRG targets for SDSS-IV/eBOSS, which began observations in Fall 2014, and will be adapted for the proposed DESI survey. We have found these methods can select high-redshift LRGs efficiently with minimal stellar contamination; this is extremely difficult to achieve with selections that rely on optical photometry alone.Comment: 10 pages, 13 figures, Published in the Astrophysical Journa

Biodiversity and community structure of coral reefs around Krusadai Island, Gulf of Mannar, India

This paper gives the results of the surveys conducted in the Krusadai Reef for the assessment of the coral cover and biodiversity during March-May 2005, following the Line Intercept Transect Method. A total of 35 hard coral species were recorded in this reef. The total live, dead and bleached coral cover for the reef as a whole was estimated as 54.9, 18.7 and 15.4% respectively and the remaining part was covered with soft corals, sponges, seagrasses, sand and rubble. Dead coral cover was dominated by porites. Further, relative abundance values were derived for each species and they were assigned the status dominant/ abundant/ common/ uncommon/ rare. Although, no species was assigned “dominant” status, Acropora formosa belonged to the category “abundant” and all other species were either of “common” or “uncommon” status only. Fisher and Shannon diversity indices were highest (3.68 and 2.14 respectively ) in 8th site. Pielou’s evenness was highest in 7th site. SIMPER analysis revealed that Acropora formosa (33.95%) along with Acropora humilis (15.85%), Porites mannarensis (12.97%) and Montipora digitata (12.07%) were responsible for dissimilarity among various sites in the island. The average similarity in species composition was 20.5%

Magnetic interactions in the Martensitic phase of Mn rich Ni-Mn-In shape memory alloys

The magnetic properties of Mn$_{2}$Ni$_{(1+x)}$In$_{(1-x)}$ ($x$ = 0.5, 0.6, 0.7) and Mn$_{(2-y)}$Ni$_{(1.6+y)}$In$_{0.4}$ ($y$ = -0.08, -0.04, 0.04, 0.08) shape memory alloys have been studied. Magnetic interactions in the martensitic phase of these alloys are found to be quite similar to those in Ni$_2$Mn$_{(1+x)}$In$_{(1-x)}$ type alloys. Doping of Ni for In not only induces martensitic instability in Mn$_2$NiIn type alloys but also affects magnetic properties due to a site occupancy disorder. Excess Ni preferentially occupies X sites forcing Mn to the Z sites of X$_2$YZ Heusler composition resulting in a transition from ferromagnetic ground state to a state dominated by ferromagnetic Mn(Y) - Mn(Y) and antiferromagnetic Mn(Y)-Mn(Z) interactions. These changes in magnetic ground state manifest themselves in observation of exchange bias effect even in zero field cooled condition and virgin magnetization curve lying outside the hysteresis loop.Comment: Accepted in J. Appl. Phy

What can the SNO Neutral Current Rate teach us about the Solar Neutrino Anomaly

We investigate how the anticipated neutral current rate from $SNO$ will sharpen our understanding of the solar neutrino anomaly. Quantitative analyses are performed with representative values of this rate in the expected range of $0.8 - 1.2$. This would provide a $5 - 10 \sigma$ signal for $\nu_e$ transition into a state containing an active neutrino component. Assuming this state to be purely active one can estimate both the $^8B$ neutrino flux and the $\nu_e$ survival probability to a much higher precision than currently possible. Finally the measured value of the $NC$ rate will have profound implications for the mass and mixing parameters of the solar neutrino oscillation solution.Comment: Brief discussion on the first NC result from SNO added; final version to be published in the MPL