Confinement of fermions in tachyon matter

In this paper we develop a phenomenological model inspired by QCD that mimics QCD theory. We use gauge theory in color dielectric medium ($G(\phi)$) coupled with fermion fields to produce scalar and vector confinement in chromoelectric flux tube scenario. Abelian theory will be used to approximate the non-Abelian QCD theory in a consistent manner. We will calculate vector and scalar glueballs and compare the result to the existing simulation and experimental results and projections. The QCD-like vacuum associated with the model will be calculated and its behavior studied relative to changing quark masses. We will also comment on the relationship between tachyon condensation, dual Higgs mechanism, QCD monopole condensation and their association with confinement. The behavior of the QCD string tension obtained from the vector potential of the model will be studied to establish vector dominance in confinement theories.Comment: 20 pages, 8 figures. Version published in AHE

The (de)-confinement transition in tachyonic matter at finite temperature

In this paper we present a QCD motivated model that mimics QCD theory. We examine the characteristics of the gauge field coupled with the color dielectric function ($G$) in the presence of temperature ($T$). The aim is to achieve confinement at low temperatures $T<T_{c}$, ($T_{c}$, is the critical temperature), similar to what occurs among quarks and gluons in hadrons at low energies. Also, we investigate scalar glueballs and QCD string tension and effect of temperature on them. To achieve this, we use the phenomenon of color dielectric function in gauge fields in a slowly varying tachyon medium. This method is suitable for analytically computing the resulting potential, glueball masses and the string tension associated with the confinement at a finite temperature. We demonstrate that the color dielectric function changes Maxwell's equation as a function of the tachyon fields and induces the electric field in a way that brings about confinement during the tachyon condensation below the critical temperature.Comment: 12 pages, 3 figures; version published in AHE

Internal Assessment as Predictor of External Evaluation in A Senior High School in Ghana: An Exploratory Case Study

This study explored the relationship between performance of senior secondary school students in internal tests (school/teacher generated) and external assessments conducted by West Africa Secondary School Certificate Examination (WASSCE) in Ghana.  A deductive comparative design approach was used for the study. A longitudinal data consisting of 111 student scores together with their corresponding scores in internal and external assessments spanning their second cycle education in a purposively selected public senior secondary school between 2013 and 2016 in the Bono East region for the study. Specifically, the study aimed at determining if there existed any significant difference between external and internal performance of students in core mathematics. Based on the data, a predictive model for overall student assessment with particular reference to the selected case was formulated. Data was analysed using statistical tools such descriptive statistics, correlation coefficients, paired sample t-test and regression analysis. The results were presented using tables and graphs. The study revealed a positive relationship between internal assessments marks and external assessment scores in core mathematics with the internal assessment scores being an important forecaster of student external assessment scores. Based on the findings, the study recommends that teachers engage students seriously in the teaching of mathematics while they are in the school, since that contributes considerably in predicting students’ performance in external assessment. Keywords: internal assessment, external assessment, high school, models DOI: 10.7176/JEP/12-3-07 Publication date: January 31st 202

Hybrid Stars Built with Density Dependent Models

Using a density dependent quark model and a relativistic model within the mean-field approximation for hadrons with density dependent meson-baryon couplings, we construct, for the first time, models that describe hybrid neutron stars consisting of nucleons and exotic baryons (hyperons and $\Delta$-resonances). We do the study using a Maxwell construction. The quark-hadron phase transition in the stellar matter is determined through; the structure, composition, and properties of the hybrid neutron star matter. The macroscopic properties of the star are determined, and the results for these particular models are found to be compatible with recent observational astrophysical data.Comment: 9 pages, 7 figure

Clinical characteristics of males with systemic lupus erythematosus (SLE) in an inception cohort of patients in Ghana

Background: Systemic Lupus Erythematosus (SLE) is said to be rare in Sub-Saharan Africa and even rarer in males worldwide. SLE is mostly considered a disease of women, though men may also be affected, and this may lead to a delay in diagnosis in men. The result is a greater burden of inflammation and subsequent organ damage over time. Method: Data from the medical records of 13 male patients diagnosed with SLE at the Rheumatology Clinic of Korle-Bu Teaching Hospital between January 2014 and January 2017 was retrospectively analyzed. Results: A total of 13 male patients out of a total of 134 SLE patients were included in our analysis. The mean age was 30.62 ± SD 8.47 years (range of 17 to 46 years). All of them (100%) presented with constitutional features. The most common ACR criteria observed was 61.5 % rash, 54.5 % oral ulcers, 92.3% arthritis, 61.5 % serositis and 38.5% renal involvement, 46.2 % CNS involvement. Looking at their serological profile, 91.7 % had a positive antinuclear antibody (ANA). 33.3 % had positive anti-dsDNA and 58.3 % extractable nuclear antigens. The mean duration from onset of symptoms to diagnosis was 21.31 months. Five patients were diagnosed with lupus nephritis, all at the time of diagnosis. There were no mortalities. Conclusion: Male SLE patients in Ghana are comparable to other populations, with arthritis and constitutional features being predominant early features and lupus nephritis being the main early indicator of organ damage. This should warrant aggressive management in male patients. Funding: None declared Keywords: Male, systemic lupus erythematosus, nephritis, Sub-Saharan Afric

Blue Food Demand Across Geographic and Temporal Scales

Numerous studies have focused on the need to expand production of ‘blue foods’, defined as aquatic foods captured or cultivated in marine and freshwater systems, to meet rising population- and income-driven demand. Here we analyze the roles of economic, demographic, and geographic factors and preferences in shaping blue food demand, using secondary data from FAO and The World Bank, parameters from published models, and case studies at national to sub-national scales. Our results show a weak cross-sectional relationship between per capita income and consumption globally when using an aggregate fish metric. Disaggregation by fish species group reveals distinct geographic patterns; for example, high consumption of freshwater fish in China and pelagic fish in Ghana and Peru where these fish are widely available, affordable, and traditionally eaten. We project a near doubling of global fish demand by mid-century assuming continued growth in aquaculture production and constant real prices for fish. Our study concludes that nutritional and environmental consequences of rising demand will depend on substitution among fish groups and other animal source foods in national diets

Phenomenology of strong interactions: towards an effective theory for low energy QCD

In this paper, we develop models applicable to phenomenological particle physics by using the string analogy of particles. These theories can be used to investigate the phenomenology of confinement, deconfinement, chiral condensate, QGP phase transitions, and even the evolution of the early universe. Other confining properties such as scalar glueball mass, gluon mass, glueball-meson mixing states, QCD vacuum, and color superconductivity can also be investigated in these model frameworks. We use one of the models to describe the phenomenon of color confinement among glueballs at the end of the paper. The models are built based on the Dirac–Born–Infeld (DBI) action modified for open strings with their endpoints on a Dp-brane or brane–anti-brane at a tachyonic vacuum

Confinement of Fermions in Tachyon Matter at Finite Temperature

We study a phenomenological model that mimics the characteristics of QCD theory at finite temperature. The model involves fermions coupled with a modified Abelian gauge field in a tachyon matter. It reproduces some important QCD features such as confinement, deconfinement, chiral symmetry, and quark-gluon-plasma (QGP) phase transitions. The study may shed light on both light and heavy quark potentials and their string tensions. Flux tube and Cornell potentials are developed depending on the regime under consideration. Other confining properties such as scalar glueball mass, gluon mass, glueball-meson mixing states, and gluon and chiral condensates are exploited as well. The study is focused on two possible regimes, the ultraviolet (UV) and the infrared (IR) regimes