Cosmography of f(R) - brane cosmology

Cosmography is a useful tool to constrain cosmological models, in particular dark energy models. In the case of modified theories of gravity, where the equations of motion are generally quite complicated, cosmography can contribute to select realistic models without imposing arbitrary choices a priori. Indeed, its reliability is based on the assumptions that the universe is homogeneous and isotropic on large scale and luminosity distance can be "tracked" by the derivative series of the scale factor a(t). We apply this approach to induced gravity brane-world models where an f(R)-term is present in the brane effective action. The virtue of the model is to self-accelerate the normal and healthy DGP branch once the f(R)-term deviates from the Hilbert-Einstein action. We show that the model, coming from a fundamental theory, is consistent with the LCDM scenario at low redshift. We finally estimate the cosmographic parameters fitting the Union2 Type Ia Supernovae (SNeIa) dataset and the distance priors from Baryon Acoustic Oscillations (BAO) and then provide constraints on the present day values of f(R) and its second and third derivatives.Comment: 9 pages, 3 figures, to appear in Phys. Rev.

Worse than a big rip?

We show that a generalised phantom Chaplygin gas can present a future singularity in a finite future cosmic time. Unlike the big rip singularity, this singularity happens for a finite scale factor, but like the big rip singularity, it would also take place at a finite future cosmic time. In addition, we define a dual of the generalised phantom Chaplygin gas which satisfies the null energy condition. Then, in a Randall-Sundrum 1 brane-world scenario, we show that the same kind of singularity at a finite scale factor arises for a brane filled with a dual of the generalised phantom Chaplygin gas.Comment: 6 pages, 4 figures, RevTeX 4. Discussion expanded and references added. Version to appear in PL

Social Construction of Reality Television: An Analysis of Print Journalism Coverage of All-American Muslim

Understandably, the perception of Muslims in America was negative after September 11, 2001. Immediately after the terrorist attacks, scholars sought to understand the impact of the media coverage on perceptions of Muslim Americans. Nisbet and Shanahan (2004) found that less than a third of Americans felt that Islamic values were similar to Christian values. This study analyzes 271 articles from American newspapers and news wires covering the television show All-American Muslim, which was canceled after one season on The Learning Channel (TLC) (Goldberg, 2012)

The use of magnetic susceptibility measurements to determine pollution of agricultural soils in road proximity

This research work presents a study on the application of magnetic susceptibility measurements and geochemical analysis for mapping or assessing heavy metal pollution in the agricultural soil in road proximity. The research work was also done to check any runoff of heavy metals pollution to the Owabi dam which serves as the main water sources to catchment areas and the whole of Kumasi Metropolis. This research work was conducted along the asphalt road closed to Amamfrom Community in the southern part of Ghana. The study revealed that magnetic susceptibility measurements can be used as a proxy and fastest method of determining heavy metal pollution in agricultural soils. The results showed three most important trends: 1) the samples collected near the road have higher values of magnetic susceptibility and mean heavy metals content than those collected far from the road exhaust; 2) some of the sample areas undisturbed by erosion and weathering have significant magnetic susceptibility and heavy metals contents; 3) some of the sample areas washed away by erosion are believed to be deposited in Owabi Dam due to their low ground reliefs. Therefore, future research should concentrate on Owabi Dam which may be polluted by the runoff from these heavy metals.Key words: Magnetic susceptibility, heavy metal, pollution, road proximity

Tingkat Partisipasi dan Kemandirian Petani Alumni Sekolah Lapangan Pengelolaan Tanaman Terpadu (Kasus Desa Kebon Pedes, Kecamatan Kebon Pedes, Kabupaten Sukabumi, Provinsi Jawa Barat)

Pendekatan pengembangan pertanian dilakukan secara terpusat dari atas ke bawah . Kegagalan dalam mencapaiupaya pembangunan pertanian, menjadikan ahli di waktu itu berkata sangat penting untuk mengubah paradigmapengembangan pertanian berkelanjutan yang bottom up. Sekolah lapangan (SL-PTT) sebagai bagian darikegiatan penyuluhan pertanian, petan menunjuk untuk memberdayakan kaum, ini adalah salah satu cara untukmencapai titik pembangunan pertanian, sehingga lebih menarik untuk belajar lebih jauh. Tujuan penelitiantentang kondisi masa sekarang adalah untuk menganalisis pemberdayaan petani korelasi model sl-ptt dengantingkat partisipasi dan otonomi. Penelitian ini digunakan metode dan kuantitatif tersebut didukung dengan datakualitatif. Kuantitas data dikumpulkan dengan menggunakan metode dengan 42 survei peserta SL-PTT petani.Responden dipilih dengan menerapkan metode sampel acak berlapis. Di samping itu, data kualitatifdikumpulkan dengan wawancara mendalam. Hasilnya menunjukkan bahwa aktivitas sl-ptt mempunyai korelasisignifikan dengan tingkat partisipasi dan otonomi petani. Kebanyakan petani berada di tingkat tengah danpartisipasi otonomi

Simulation Modeling and Analysis of Complex Port Operations with Multimodal Transportation

AbstractWorld trade has been increasing dramatically in the past two decades, and as a result containers exchange has grown significantly. Accordingly, container terminals are expanding to meet this increase and new container ports have opened. Ports with one or more container terminals are considered complex systems in which many resources, entities and transporters interact to achieve the objective of safely moving containers delivered by ships inland as well as loading containers delivered by trucks and rail onto ships. Ports with multimodal transportation systems are in particular complex as they typically operate with ships arriving to one or more terminals, multiple quay cranes, rubber tyred gantry cranes, trains, and trucks delivering containers of different types to terminals.With several resources of different types working and interacting, the system can be so complex that it is not easy to predict the behavior of the system and its performance metrics without the use of simulation. In this paper, a generic discrete-event simulation that models port operations with different resource types including security gates, space, rubber tyred gantry cranes, trains, quay cranes, and arriving and departing ships, trucks, and trains is presented. The analysis will entail studying various scenarios motivated by changes in different inputs to measure their impact on the outputs that include throughput, resource utilization and waiting times

The Effectiveness of Using Response- based Strategy in Enhancing Students' Levels of Engagement, Motivation, Problem-solving Skills, and Critical Thinking

The study analyzed the efficacy of response-based teaching tactics in enhancing students' levels of engagement, motivation, problem-solving skills, and critical thinking by utilizing data and a mixed-methods research methodology. There was a total of 30 students in the sample, 15 of whom were assigned to each of the two groups (response-based techniques and conventional instruction). Researchers also looked at how factors like teacher background and technological sophistication influenced the success of these techniques in the classroom. The students participated in a pre-test to define a starting point and a post-test to evaluate growth throughout the study. The efficacy of the response-based tactics was determined by statistical analysis using t-tests, ANOVA, and Cohen's d. Teacher and student demographics, as well as information about classroom practises and the usage of technology, were gathered through an online survey. Student perceptions of their own problem-solving and critical-thinking skills, as well as their level of classroom participation and motivation, were also probed in the survey. Both quantitative and qualitative approaches were employed to gather and analyze the data for this study. In terms of improving students' interest, motivation, problem-solving skills, and critical thinking, the results demonstrated that response-based teaching tactics were superior to more conventional methods. However, it was discovered that teacher traits and technology use influenced the efficacy of the response-based tactics. The findings also suggested that response-based teaching tactics might be useful in online classrooms, with the caveat that the success of such strategies would depend on the specific nature of the strategies employed and the specific features of the technology tools used. Conclusions from the study indicate that using response-based teaching methodologies can improve students' interest, motivation, problem-solving skills, and critical-thinking capacities. This study's methodology and statistical methods can serve as a foundation for other studies in this field. Keywords: response-based teaching strategies, traditional teaching approaches, student engagement, student motivation, problem-solving skills, critical thinking abilities DOI: 10.7176/JEP/14-27-10 Publication date:September 30th 2023

Epley’s maneuver versus Semont’s maneuver in treatment of posterior canal benign positional paroxysmal vertigo

Background: Benign paroxysmal positional vertigo (BPPV) is characterized by brief but violent attacks of paroxysmal vertigo provoked by certain positions of the head. BPPV is the most common cause of vertigo, resulting from migration of otoconia into the semicircular canals. Majority of patients have posterior canal BPPV. Epley’s Canalith Repositioning and Semont Liberatory Maneuver have been shown to be highly efficacious in the successfultreatment of posterior canal BPPV. The main objective of this study was to compare the efficacy of Epley’s maneuver versus Semont’s maneuver in the management of benign paroxysmal positional vertigo.Methods: This study was conducted in the Department of Otorhinolaryngology of a rural Medical College in Kerala, for a period of one and half year, from January 2015 to June 2016. It was an observational prospective cohort study. 200 patients with posterior canal BPPV were enrolled in this study based on inclusion and exclusion criteria. Patients were allotted alternatively to Epley’s group and Semont’s group, 100 patients in each group based on the treatment maneuvers they underwent. Efficacy of maneuvers were assessed at the end of 1st week, 1st month and 3rd month on the basis of resolution of symptoms and Dix-Hallpike negativity.Results: Of the 100 cases managed by Epley’s maneuver 95 cases showed complete relief of symptoms after 3 months. Out of 100 cases managed by Semont’s maneuver, 94 cases showed complete recovery after 3 months. The results were compared by Chi square test, as the data was mainly qualitative in nature. The results of both the groups were compared at the end of 1st week, 1st month and 3rd month, which revealed that both the Semont’s and Epley’s maneuver are equally effective in the treatment of posterior canal BPPV.Conclusions: Both Epley’s and Semont’s maneuver are equally effective for treating the patients of posterior canal benign paroxysmal positional vertigo