Proposal for an experiment to search for Randall-Sundrum type corrections to Newton's law of gravitation

String theory, as well as the string inspired brane-world models such as the Randall-Sundrum (RS) one, suggest a modification of Newton's law of gravitation at small distance scales. Search for modifications of standard gravity is an active field of research in this context. It is well known that short range corrections to gravity would violate the Newton-Birkhoff theorem. Based on calculations of RS type non-Newtonian forces for finite size spherical bodies, we propose a torsion balance based experiment to search for the effects of violation of this celebrated theorem valid in Newtonian gravity as well as the general theory of relativity. We explain the main principle behind the experiment and provide detailed calculations suggesting optimum values of the parameters of the experiment. The projected sensitivity is sufficient to probe the Randall-Sundrum parameter up to 10 microns.Comment: 4 pages and 5 figures, figures improved, minor clarifications and few references added, final version to appear in PRD (rapid communications

Non-relativistic limit of Randall-Sundrum model: solutions, applications and constraints

In the Randall-Sundrum model with one brane, we found the approximate and exact solutions for gravitational potentials and accelerations of test bodies in these potentials for different geometrical configurations. We applied these formulas for calculation of the gravitational interaction between two spheres and found the approximate and exact expressions for the relative force corrections to the Newton's gravitational force. We demonstrated that the difference between relative force corrections for the approximate and exact cases increases with the parameter $l$ (for the fixed distance $r$ between centers of the spheres). On the other hand, this difference increases with decreasing of the distance between the centers of the spheres (for the fixed curvature scale parameter $l$). We got the upper limit for the curvature scale parameter $l\lesssim 10\, \mu$m. For these values of $l$, the difference between the approximate and exact solutions is negligible.Comment: LaTex 11 pages, 3 figure

IMPACT OF TEACHERS' MINDFULNESS AND PROFESSIONAL SKILLS TOWARDS CLASSROOM CLIMATE ON STUDENT OUTCOMES WHILE LEARNING ENGLISH AS A SECOND LANGUAGE IN SRI LANKA

Public education system of Sri Lanka suffers from poor education outcomes and wide disparities in academic achievement across schools, and studies reveal that students’ outcomes are best when the teachers are qualified in both subjects, they are assigned to teach and in pedagogy. At present teacher stress has become a critical issue in the educational field which affects negatively towards classroom climate; teacher student relationship, teacher creativity, teaching methodologies and student outcomes, while a positive classroom climate results in better academic, social, and emotional outcomes for students. Though the studies have revealed that teacher can improve their well-being, as well as the classroom climate and the student outcomes through the use of mindfulness practices which was taught by the Buddha 2600 years ago, any convincing evidence of the influence of both, teachers’ mindfulness and professional skills on classroom climate towards student outcomes in Sri Lanka or any other country cannot be found. To fulfil that gap, this study explored the influence of teachers’ mindfulness and professional skills on classroom climate towards student outcomes in the government schools in Sri Lanka, using pre-test and post-test experimental design. Data was collected before and after 8-week intervention period, from a sample consisted of 230 students and nine teachers of English, that were observed quantitatively. Findings revealed that teachers’ mindfulness and professional skills as two of the most influential factors that decide the student outcomes directly and via classroom climate of a school, that offer valuable recommendations to the education system in Sri Lanka, in order to enhance student academic and behavioural outcomes by taking steps to improve the professional skills of teachers and the mindful living of both teachers and students.  Article visualizations

IMPACT OF TEACHERS’ PROFESSIONAL SKILLS ON STUDENT ACHIEVEMENT WHILE LEARNING ENGLISH AS A SECOND LANGUAGE IN SRI LANKA

The public education system of Sri Lanka suffers from poor education outcomes and wide disparities in academic achievement across schools, and studies have revealed that students’ outcomes are best when the teachers are qualified in both, the subjects they are assigned to teach and in pedagogy. Though the studies have revealed that student outcomes can be improved by improving the professional skills of teachers, any convincing evidence of the influence of teachers’ professional skills on student outcomes in Sri Lanka cannot be found. To fulfil that gap, this study explored the influence of teachers’ professional skills on student outcomes in government schools in Sri Lanka, using the pretest, posttest experimental design. Data were collected before and after the 8-week intervention period, from a sample consisting of 102 students and four teachers of English, that were observed quantitatively. Findings revealed that teachers’ professional skills as one of the most influential factors that decide the student outcomes directly of a school, which offer valuable recommendations to the education system in Sri Lanka, in order to enhance student outcomes by taking steps to improve the professional skills of teachers.  Article visualizations

Precursors, black holes, and a locality bound

We revisit the problem of precursors in the AdS/CFT correspondence. Identification of the precursors is expected to improve our understanding of the tension between holography and bulk locality and of the resolution of the black hole information paradox. Previous arguments that the precursors are large, undecorated Wilson loops are found to be flawed. We argue that the role of precursors should become evident when one saturates a certain locality bound. The spacetime uncertainty principle is a direct consequence of this bound.Comment: 26 pages, 8 figs; reference added, minor clarification in sec. 2; incorrect draft mistakenly used in version

TAT-peptide conjugated repurposing drug against SARS-CoV-2 main protease (3CLpro): potential therapeutic intervention to combat COVID-19

The Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that originated in Chinese city of Wuhan has caused around 906,092 deaths and 28,040,853 confirmed cases worldwide (WHO, 11 September, 2020). In a life-threatening situation, where there is no specific and licensed anti-COVID-19 vaccine or medicine available; the repurposed drug might act as a silver bullet. Currently, more than 211 vaccines, 80 antibodies, 31 antiviral drugs, 35 cell-based, 6 RNA-based and 131 other drugs are in clinical trials. It is therefore utter need of the hour to develop an effective drug that can be used for the treatment of COVID-19 before a vaccine can be developed. One of the best-characterized and attractive drug targets among coronaviruses is the main protease (3CL^{pro}). Therefore, the current study focuses on the molecular docking analysis of TAT-peptide^{47–57} (GRKKRRQRRRP)-conjugated repurposed drugs (i.e., lopinavir, ritonavir, favipiravir, and hydroxychloroquine) with SARS-CoV-2 main protease (3CL^{pro} to discover potential efficacy of TAT-peptide (TP) - conjugated repurposing drugs against SARS-CoV-2. The molecular docking results validated that TP-conjugated ritonavir, lopinavir, favipiravir, and hydroxychloroquine have superior and significantly enhanced interactions with the target SARS-CoV-2 main protease. In-silico approach employed in this study suggests that the combination of the drug with TP is an excelling alternative to develop a novel drug for the treatment of SARS-CoV-2 infected patients. The development of TP based delivery of repurposing drugs might be an excellent approach to enhance the efficacy of the existing drugs for the treatment of COVID-19. The predictions from the results obtained provide invaluable information that can be utilized for the choice of candidate drugs for in vitro, in vivo and clinical trials. The outcome from this work prove crucial for exploring and developing novel cost-effective and biocompatible TP conjugated anti-SARS-CoV-2 therapeutic agents in immediate future

Structural evolution and dopant occupancy preference of yttrium-doped potassium sodium niobate thin films

Sodium potassium niobate (KNN) is the most promising candidate for lead-free piezoelectric material, owing to its high Curie temperature and piezoelectric coefficients among the non-lead piezoelectric. Numerous studies have been carried out to enhance piezoelectric properties of KNN through composition design. This research studied the effects of yttrium concentrations and lattice site occupancy preference in KNN films. For this research, the yttrium-doped KNN thin films (mol% = 0, 0.1, 0.3, 0.5, 0.7 and 0.9) were fabricated using the sol-gel spin coating technique and had revealed the orthorhombic perovskite structures. Based on the replacement of Y3+ ions for K+/ Na+ ions, it was found that the films doped with 0.1 to 0.5 mol% of yttrium had less lattice strain, while films with more than 0.5 mol% of Y3+ ions had increased strain due to the tendency of Y3+ to occupy the B-site in the perovskite lattice. Furthermore, by analysing the vibrational attributes of octahedron bonding, the dopant occupancy at A-site and B-site lattices could be identified. O-Nb-O bonding was asymmetric and became distorted due to the B-site occupancy of yttrium dopants at high dopant concentrations of >0.5 mol%. Extra conduction electrons had resulted in better resistivity of 2.153× 106 Ω at 0.5 mol%, while higher resistivity was recorded for films prepared with higher concentration of more than 0.5 mol%. The introduction of Y3+ improved the grain distribution of KNN structure. Further investigations indicated that yttrium enhances the surface smoothness of the films. However, at high concentrations (0.9 mol%), the yttrium increases the roughness of the surface. Within the studied range of Y3+ , the film with 0.5 mol% Y3+ represented a relatively desirable improvement in dielectric loss, tan δ and quality factor, Qm

Supplementing a-Linolenic acid in the in vitro maturation media improves nuclear maturation rate of oocytes and early embryonic development in the Nili Ravi buffalo

The present study was conducted to investigate the effect of omega-3 poly unsaturated fatty acid (PUFA), α-linolenic acid (ALA; 18:3 n-3) on the in vitro maturation (IVM) of buffalo oocytes and subsequent embryonic development. Buffalo cumulusoocyte complexes (COCs; n = 2282) were in vitro matured in TCM-199 (0.6% fatty acid free bovine serum albumin, 0.02 Units/ml FSH, 1 µg/ml 17-β-estradiol, 10 µg/ml epidermal growth factor, 50 µg/ml gentamicin) supplemented with 0 (control), 25, 50, 100, 150 or 300 µm ALA under an atmosphere of 5% CO2 in air at 38.5ºC for 22-24 h. The matured oocytes were then fertilized in Tyrode’s Albumin Lactate Pyruvate (TALP) medium and cultured in synthetic oviductal fluid (SOF) medium. Concentrations up to 100 μm ALA improves (P ≤ 0.05) the cumulus expansion compared to control. Higher percentage of oocytes reaching MII stage was observed at 50 μm and 100 μm of ALA compared to control (P ≤ 0.05). Concentrations of 150 and 300 µm ALA were detrimental both for cumulus expansion and nuclear maturation rate of buffalo oocytes. Moreover, supplementation with 100 μm ALA improved (P ≤ 0.05) cleavage rate compared to control and treatment with 50 and 100 μm ALA yielded significantly higher morulae compared to control. The results of present study indicate that the supplementation with 100 μm ALA to the IVM medium improves nuclear maturation rate of buffalo oocytes and subsequent early embryonic development

Kurt Symanzik - a stable fixed point beyond triviality

In 1970 Kurt Symanzik proposed a "precarious" phi**4-theory with a negative quartic coupling constant as a valid candidate for an asymptotically free theory of strong interactions. Symanzik's deep insight in the non-trivial properties of this theory has been overruled since then by the Hermitian intuition of generations of scientists, who considered or consider this actually non-Hermitian highly important theory to be unstable. This short - certainly controversial - communication tries to shed some light on the historical and formalistic context of Symanzik's theory in order to sharpen our (quantum) intuition about non-perturbative theoretical physics between (non)triviality and asymptotic freedom.Comment: 6 pages, no figures, new style files, revised for typos, improved discussion, new references adde