Causality Constraints on Massive Gravity

The de Rham-Gabadadze-Tolley massive gravity admits pp-wave backgrounds on which linear fluctuations are shown to undergo time advances for all values of the parameters. The perturbations may propagate in closed time-like curves unless the parameter space is constrained to a line. These classical phenomena take place well within the theory's validity regime.Comment: 6 pages, 4 figures; to appear in PR

Stacking the Equiangular Spiral

We present an algorithm that adapts the mature Stack and Draw (SaD) methodology for fabricating the exotic Equiangular Spiral Photonic Crystal Fiber. (ES-PCF) The principle of Steiner chains and circle packing is exploited to obtain a non-hexagonal design using a stacking procedure based on Hexagonal Close Packing. The optical properties of the proposed structure are promising for SuperContinuum Generation. This approach could make accessible not only the equiangular spiral but also other quasi-crystal PCF through SaD

Penerapan Model Pembelajaran Kooperatif Tipe Group Investigation untuk Meningkatkan Hasil Belajar IPA Siswa Kelas V Sekolah Dasar Negeri 020 Padang Mutung

This research is motivated by the fact that the learning outcomes of students in science subjects low it can be seen from the symptoms is of 20 students, 12 people or 61% of students do not reach KKM set is 65. As many as 12 people or 63% of students no homework the teacher. When given exercises 13 people or 66% of students do with cheating, of 10 test questions only 5 to 6 questions answered correctly. The purpose of this research is to improve learning outcomes fifth grade science students of Sekolah Dasar Negeri 020 Padang Mutung by implementing cooperative learning model type group investigation. This research is a classroom action research conducted in Class IV 020 SD Negeri Padang Mutung Kampar District Kampar District, Riau Province. Research instruments consisted of a Learning Tool used in this research is guided by the Education Unit Level Curriculum (SBC), known as Curriculum 2006 learning device consists of a syllabus, lesson plans, student worksheets and observation sheet. Based on data analysis of student activity first meeting sikuls I average student activity 54% with the classification of "High Enough" at the second meeting of the average activity increased to 62% with the classification of "High Enough" At the third meeting of the second cycle the average student activity 75 % on the classification of "High" and the fourth meeting increased compared with the previous meetings by an average of 83% of student activity with the classification of "Very High". In the first cycle, it is known that the number of students who reached the KKM is 15 students (75%) of 20 students. Improved student learning outcomes in the first cycle to reach (33%). In the second cycle, the number of students who reached the KKM amounted to 17 (85%) of 20 students. This means that an increase in student science learning outcomes of the first cycle. Improved student learning outcomes in iklus II reached (41%)

Overcoming access barriers for facility-based delivery in low-income settings: insights from Bangladesh and Uganda.

Women in both Bangladesh and Uganda face a number of barriers to delivery in professional health facilities, including costs, transportation problems, and sociocultural norms to deliver at home. Some women in both the countries manage to overcome these barriers. This paper reports on a comparative qualitative study investigating how some women and their families were able to use professional delivery services. The study provides insights into the decision-making processes and overcoming access barriers. Husbands were found to be particularly important in Uganda, while, in Bangladesh, a number of individuals could influence care-seeking, including unqualified local healers or traditional birth attendants. In both the settings, cost and transport barriers were often overcome through social networks. Social prohibitions on birth in the health facility did not feature strongly in women's accounts, with several Ugandan women explaining that friends or peers also used facilities, while, in Bangladesh, perceived complications apparently justified the use of professional medical care. Investigating the ways in which some women can overcome common barriers can help inform policy and planning to increase the use of health facilities for child delivery

Chemical and biological investigations of Delonix regia (Bojer ex Hook.) Raf.

U radu je opisana izolacija pet sastojaka petroleterske i diklormetanske frakcije metanolnog ekstrakta kore biljke Delonix regia: lupeol (1), epilupeol (2), β-sitosterol (3), stigmasterol (4) i p-metoksibenzaldehid (5). Nadalje, testirano je antimikrobno djelovanje različitih ekstrakata difuzijskom metodom na disku (15 μg mm2). Zone inhibicije za sastojke topljive u petroleteru, tetraklormetanu i diklormetanu bile su 914 mm, 1113 mm, odnosno 920 mm, dok je zona inhibicije standarda kanamicina bila 2025 mm. U biološkom pokusu smrtnosti morskih kozica najveću toksičnost pokazali su spojevi topljivi u tetraklormetanu (LC50 = 0,83 μg mL1), dok je topljivost sastojaka topljivih u petroleteru i diklormetanu bila LC50 14,94, odnosno 3,29 μg mL1, a standarda vinkristin sulfata 0,812 μg mL1. Ovo je prvo izvješće o izolaciji sastojaka, antimikrobnom djelovanju i citotoksičnosti biljke D. regia.In this study five compounds, lupeol (1), epilupeol (2), β-sitosterol (3), stigmasterol (4) and p-methoxybenzaldehyde (5) were isolated from the petroleum ether and dichloromethane fractions of a methanolic extract of the stem bark of Delonix regia. Antimicrobial screening of the different extracts (15 μg mm2) was conducted by disc diffusion method. The zones of inhibition demonstrated by the petroleum ether, carbon tetrachloride and dichloromethane fractions ranged from 914 mm, 1113 mm and 920 mm, respectively, compared to kanamycin standard with the zone of inhibition of 2025 mm. In brine shrimp lethality bioassay, the carbon tetrachloride soluble materials demonstrated the highest toxicity with LC50 of 0.83 μg mL1, while petroleum ether and dichloromethane soluble partitionates of the methanolic extract revealed LC50 of 14.94 and 3.29 μg mL1, respectively, in comparison with standard vincristine sulphate with LC50 of 0.812 μg mL1. This is the first report on compounds separation from D. regia, their antimicrobial activity and cytotoxicity