Spectra, vacua and the unitarity of Lovelock gravity in D-dimensional AdS spacetimes

We explicitly confirm the expectation that generic Lovelock gravity in D dimensions has a unitary massless spin-2 excitation around any one of its constant curvature vacua just like the cosmological Einstein gravity. The propagator of the theory reduces to that of Einstein's gravity, but scattering amplitudes must be computed with an effective Newton's constant which we provide. Tree-level unitarity imposes a single constraint on the parameters of the theory yielding a wide range of unitary region. As an example, we explicitly work out the details of the cubic Lovelock theory.Comment: 9 pages, 2 references adde

Green's Matrix for a Second Order Self-Adjoint Matrix Differential Operator

A systematic construction of the Green's matrix for a second order, self-adjoint matrix differential operator from the linearly independent solutions of the corresponding homogeneous differential equation set is carried out. We follow the general approach of extracting the Green's matrix from the Green's matrix of the corresponding first order system. This construction is required in the cases where the differential equation set cannot be turned to an algebraic equation set via transform techniques.Comment: 19 page

Minimising the environmental footprint of industrial-scaled cleaning processes by optimisation of a novel clean-in-place system protocol

Cleaning of food fouling deposits in processing equipment is costly and time consuming. Fouling deposits form as a result of adhesion of species to the surface and cohesion between elements of the material. Cleaning can result from either or both adhesive and cohesive failure. In this study, the aim was to investigate the removal kinetics of an adhesive material and to design a novel cleaning in place (CIP) protocol for these kinds of materials at industrial scale to reduce environmental impact of cleaning processes. It was detected that different variables controlled the cleaning process in removal of adhesive deposit Temperature was not found as a significant variable in the initial stage of cleaning. Velocity of cleaning water controlled the cleaning at this stage when top layers of the deposit were removed by fluid mechanical removal due to breakdown of weak cohesive interaction. In the later cleaning stage, both velocity and temperature significantly contributed to cleaning, which suggested that both hydrodynamic forces and rheological changes are needed to overcome adhesion forces between the deposit and surface. Hence, a novel two step CIP protocol was proposed due to existence of different mechanisms in cleaning. When compared with conventional one step CIP protocols currently used in the processing plants, the proposed CIP protocol reduced the energy consumption by 40% without decreasing the cleaning efficiency. (C) 2015 Elsevier Ltd. All rights reserved.Turkish Ministry of National EducationMinistry of National Education - Turkey; ZEAL project [TP//ZEE/6/1/21191]; Technology Strategy Board's Collaborative Research and Development programme; BBSRCUK Research & Innovation (UKRI)Biotechnology and Biological Sciences Research Council (BBSRC) [BB/D523386/1] Funding Source: UKRI; EPSRCUK Research & Innovation (UKRI)Engineering & Physical Sciences Research Council (EPSRC) [EP/K011820/1] Funding Source: UKRI; Biotechnology and Biological Sciences Research CouncilUK Research & Innovation (UKRI)Biotechnology and Biological Sciences Research Council (BBSRC) [BB/D523386/1] Funding Source: researchfish; Engineering and Physical Sciences Research CouncilUK Research & Innovation (UKRI)Engineering & Physical Sciences Research Council (EPSRC) [EP/K011820/1] Funding Source: researchfishIP (the first author) acknowledges the financial support from the Turkish Ministry of National Education. This paper reports results from the ZEAL project TP//ZEE/6/1/21191, which involves; Alfa Laval, Cadbury Ltd., Ecolab Ltd., Newcastle University, Heineken UK Ltd., GEA Process Engineering Ltd., Unilever UK Central Resources Ltd., Imperial College of Science Technology and Medicine, GlaxSmithKline, Bruker Optics Ltd. and the University of Birmingham. The project is co-funded by the Technology Strategy Board's Collaborative Research and Development programme, following open competition. For more information visit

All unitary cubic curvature gravities in D dimensions

We construct all the unitary cubic curvature gravity theories built on the contractions of the Riemann tensor in D -dimensional (anti)-de Sitter spacetimes. Our construction is based on finding the equivalent quadratic action for the general cubic curvature theory and imposing ghost and tachyon freedom, which greatly simplifies the highly complicated problem of finding the propagator of cubic curvature theories in constant curvature backgrounds. To carry out the procedure we have also classified all the unitary quadratic models. We use our general results to study the recently found cubic curvature theories using different techniques and the string generated cubic curvature gravity model. We also study the scattering in critical gravity and give its cubic curvature extensions.Comment: 24 pages, 1 figure, v2: A subsection on cubic curvature extensions of critical gravity is added, v3: The part regarding critical gravity is revised. Version to appear in Class. Quant. Gra

Cytotoxic properties of the stem bark of Citrus reticulata Blanco (Rutaceae)

The bioassay-guided fractionation of the n-hexane extract of Citrus reticulata Blanco (Rutaceae) stem bark yielded scoparone (1), xanthyletin (2), lupeol (3), β-amyrin (4), stigmasterol (5), β-sitosterol (6) and palmitic acid. The structures of these compounds were determined by comprehensive spectroscopic analyses, i.e., 1D and 2D NMR and EI-MS, and by comparison with the reported data. Extracts, fractions and isolated compounds 1-6 were assessed for cytotoxicity by the MTT assay against three human cancer cell lines, i.e., human lung adenocarcinoma cell line A549, human breast adenocarcinoma cell line MCF7 and human Caucasian prostate adenocarcinoma cell line PC3. Significant activity of the n-hexane and the dichloromethane extracts was observed against the breast cancer cell line MCF7 with IC50s of 45.6 and 54.7 μg/mL, respectively. Moreover, the 70% ethyl acetate in n-hexane chromatographic fraction showed significant activity displaying IC50 values of 53.0, 52.4 and 49.1 μg/mL against the cancer cell lines A549, MCF7 and PC3, respectively. Encouragingly, an IC50 of 510.0 µg/mL against the human normal prostate cell line PNT2 indicated very low toxicity, and hence favourable selectivity indices for the 70% ethyl acetate in n-hexane fraction in the range of 9.6-10.4 towards cell lines A549, MCF7 and PC3. Since compounds isolated from the above fraction only delivered IC50 values in the range of 18.2-96.3, 9.2-34.1 and 7.5-97.2 μg/mL against A549, MCF7 and PC3 cell lines, respectively, synergistic action between compounds is suggested. Bioassay results valorize the anticancer effectivity of the stem bark of this plant in Cameroonian pharmacopeia

Co-producing an intervention for tobacco cessation and improvement of oral health among diabetic patients in Bangladesh

Abstract Background Tobacco consumption is a major risk factor for many diseases including diabetes and has deleterious effects on oral health. Diabetic patients are vulnerable to developing certain oral conditions. So far, no studies have attempted to co-develop a tobacco cessation intervention to be delivered in dental clinics for people with diabetes in Bangladesh. Aim To co-produce a tobacco cessation intervention for people with diabetes for use in dental clinics in Bangladesh. Objectives To assess: (1) tobacco use (patterns) and perceptions about receiving tobacco cessation support from dentists among people with diabetes attending the dental department of Bangladesh Institute of Research and Rehabilitation in Diabetes, Endocrine and Metabolic Disorders (BIRDEM) who smoke or use smokeless tobacco (ST) (2) current tobacco cessation support provision by the dentists of the dental department of BIRDEM (3) barriers and facilitators of delivering a tobacco cessation intervention at a dental clinic, and (4) to co-produce a tobacco cessation intervention with people with diabetes, and dentists to be used in the proposed context. Methods The study was undertaken in two stages in the dental department of BIRDEM, which is the largest diabetic hospital in Bangladesh. Stage 1 (July–August 2019) consisted of a cross-sectional survey among people with diabetes who use tobacco to address objective 1, and a survey and workshop with dentists working in BIRDEM, and consultations with patients to address objectives 2 and 3. Stage 2 (January 2020) consisted of consultations with patients attending BIRDEM, and a workshop with dentists to co-produce the intervention. Result All survey participants (n = 35) were interested in receiving tobacco cessation support from their dentist. We identified important barriers and facilitators to deliver tobacco cessation intervention within dental services. Barriers reported by dentists included lack of a structured support system and lack of training. As a facilitator, we identified that dentists were willing to provide support and it would be feasible to deliver tobacco cessation intervention if properly designed and embedded in the routine functioning of the dental department of BIRDEM. Through the workshops and consultations at stage 2, a tobacco cessation intervention was co-developed. The intervention included elements of brief cessation advice (using a flipbook and a short video on the harmful effects of tobacco) and pharmacotherapy. Conclusion Incorporation of tobacco cessation within dental care for people with diabetes was considered feasible and would provide a valuable opportunity to support this vulnerable group in quitting tobacco

Stable X chromosome reactivation in female human induced pluripotent stem cells

In placental mammals, balanced expression of X-linked genes is accomplished by X chromosome inactivation (XCI) in female cells. In humans, random XCI is initiated early during embryonic development. To investigate whether reprogramming of female human fibroblasts into induced pluripotent stem cells (iPSCs) leads to reactivation of the inactive X chromosome (Xi), we have generated iPSC lines from fibroblasts heterozygous for large X-chromosomal deletions. These fibroblasts show completely skewed XCI of the mutated X chromosome, enabling monitoring of X chromosome reactivation (XCR) and XCI using allele-specific single-cell expression analysis. This approach revealed that XCR is robust under standard culture conditions, but does not prevent reinitiation of XCI, resulting in a mixed population of cells with either two active X chromosomes (Xas) or one Xa and one Xi. This mixed population of XaXa and XaXi cells is stabilized in naive human stem cell medium, allowing expansion of clones with two Xas