Gender Differences in Secondary School Students’ Achievement in Chemistry in Samburu County, Kenya

The purpose of this study was to investigate the gender differences in secondary school students’ achievement in chemistry. In addition, the study sought to identify the factors that contribute to gender differences in chemistry achievement to in order to enhance the provision of equal opportunities for the learning of chemistry and all other sciences in general to both boys and girls. Cross-Sectional study design under the descriptive survey research was used. The target population of the study comprised of all the secondary school chemistry students in both public and private secondary schools in Samburu county. The accessible population were all the form three chemistry students in the county. A sample of 286 students was selected from a population of 1,238 using stratified and simple random sampling techniques. Students’ Chemistry Achievement Test (SCAT) and Students’ Gender Interview Schedule (SGIS) were used to collect data. The data collected was analyzed using both descriptive and inferential statistics. The statistics derived included the analysis of percentages, mean, standard deviation, students’ T-Test scores and Chi-Square Test (x2 test) used to establish the relationship between culturally accepted gender roles and achievement in chemistry. The findings show that there was a statistically significant gender difference in chemistry achievement in favour of boys. As a result, boys’ schools performed better than both girls’ and co-educational schools. Boys had a high affinity and interest towards chemistry than girls. Also the culturally accepted gender roles had an effect on chemistry achievement. It is recommended that the Ministry of Education should initiate in-service programmes for teachers in science courses emphasizing on relevant scientific skills to empower teachers to provide learning opportunities that would reduce the gender differences and the effect of cultural factors known to enhance gender differences in the learning and achievement in chemistry. Curriculum developers and policy makers need to develop curriculum materials that would help to reduce the gender gap in learning and achievement.

RELATIONSHIP BETWEEN CULTURAL BELIEFS AND SECONDARY SCHOOL STUDENTS’ ACHIEVEMENT IN CHEMISTRY IN SAMBURU COUNTY, KENYA

African Societies have a relatively rich body of Indigenous Knowledge. This is embodied in the Continent’s Indigenous Knowledge Systems. This knowledge has been used by the African people for thousands of years to solve their specific problems. According to Kenya National Examination Council reports, secondary school students’ achievement in chemistry has been persistently poor. This has been attributed to many factors including cultural beliefs. However, it is not clear how cultural beliefs are related to students’ achievement in chemistry. The current concern in Samburu County among parents and other education stakeholders is that, students’ achievement in chemistry is poor and is likely to be affected by cultural beliefs that have a bearing on chemistry. This study was designed to investigate the relationship between cultural beliefs and secondary school students’ achievement in chemistry in Samburu County. Descriptive Correlational survey research design was used. The target population was all the secondary school chemistry students in Samburu County. The accessible population was all the Form Three chemistry students in the County in the year 2022. Cluster sampling was used to select nine secondary schools as sampling units and this included both public and private schools.  Stratified and simple random sampling was used to select a sample of 286 students. Two instruments were used for data collection namely: Students’ Chemistry Achievement Test (SCAT) and Students’ Cultural Beliefs Questionnaire (SCBQ). The instruments were validated by five experts in educational research. The reliability coefficient of SCAT was estimated using Guttman’s Lambda (λ6) formula. This yielded a reliability coefficient of 0.80. Cronbach’s Alpha Coefficient (α) was used to estimate reliability coefficient of SCBQ. This yielded reliability coefficients of 0.85. The data collected was analyzed using both descriptive and inferential statistics. Simple Linear Regression was used to establish the relationships between the different variables in the study. All statistical tests of significance were conducted at a coefficient level of alpha (α) equal to 0.05 with the help of Statistical Package for Social Sciences (SPSS) version 23.0 for windows. There was no statistically significant relationship between Cultural Beliefs and students’ achievement in chemistry. The findings, however, indicate that there was a gender difference in achievement in chemistry in favour of boys. It is recommended that the Ministry of Education should initiate in-service courses for science teachers to equip them with requisite skills to enhance their effectiveness in teaching of chemistry and science subjects as a whole. The findings of this study would benefit chemistry teachers, curriculum developers, teacher educators and policy makers in addressing necessary interventions to facilitate meaningful learning of chemistry and thus improve students’ achievement in the subject in secondary schools Countrywide.&nbsp

Effects of Advance Organizers on Students’ Achievement in Biology in Secondary Schools in Kilifi County, Kenya

This study investigated the effects of using advance organizers on students’ achievement in biology in secondary schools in Kilifi County. Solomon Four, Non-Equivalent control group design was used in this study. The study targeted all secondary school students in Kilifi County. The accessible population consisted of all form two students in Kilifi County. Purposive sampling was used to select four co-educational secondary schools in Kilifi County. The four schools were randomly assigned to experimental groups (E1) and (E2) and control groups C1 and C2. A total of 156 students participated in the study. Data was collected using Biology Achievement Test (BAT). The reliability of BAT was estimated using Kuder-Richardson (K-R) 20 and Cronbach’s coefficient. This yielded a reliability coefficient of 0.82 and 0.79 respectively. BAT was validated by experts in science education from Egerton University. The data collected was analyzed using mean, one-way ANOVA and t-test. The level of significance was 0.05. The findings of this study show that there was statistically significant difference in achievement between learners in favour of those taught using advance organizers compared to those taught using conventional teaching methods. The findings also indicate that there was no statistically significant gender difference in achievement

Pinwheel stabilization by ocular dominance segregation

We present an analytical approach for studying the coupled development of ocular dominance and orientation preference columns. Using this approach we demonstrate that ocular dominance segregation can induce the stabilization and even the production of pinwheels by their crystallization in two types of periodic lattices. Pinwheel crystallization depends on the overall dominance of one eye over the other, a condition that is fulfilled during early cortical development. Increasing the strength of inter-map coupling induces a transition from pinwheel-free stripe solutions to intermediate and high pinwheel density states.Comment: 10 pages, 4 figure

Effects of Computer Based Mastery Learning Approach on Students’ Motivation to Learn Biology

This study investigated the effects of using Computer Based Mastery Learning (CBML) approach on secondary school students’ Motivation to learn biology. A Solomon’s Four Group design Non-equivalent Control Group research design was used in which four co-educational secondary schools were purposively sampled in Bomet District. The four schools were randomly assigned to four groups. Students in all the groups were taught the same biology content. Teachers in the experimental groups taught using CBML approach while teachers in the control groups taught using the conventional methods. The study focused on respiration topic and involved a sample of 167 Form Two students. After two weeks of teaching, all four groups were post-tested using Students’ Motivation Questionnaire (SMQ) whose reliability co-efficient was 0.79. Data were analysed using ANOVA, t-test and ANCOVA. Results indicate that students taught using CBML approach had significantly higher scores in SMQ than those taught using conventional approaches. In addition, the study established that there is no gender difference in motivation when CBML is used. The researchers conclude that CBML is an effective teaching approach which should be incorporated in the teaching of Biology. Keywords: Computer Based Mastery Learning, Student’s Motivation, Learning Biology

Inflation without Inflaton(s)

We propose a model for early universe cosmology without the need for fundamental scalar fields. Cosmic acceleration and phenomenologically viable reheating of the universe results from a series of energy transitions, where during each transition vacuum energy is converted to thermal radiation. We show that this `cascading universe' can lead to successful generation of adiabatic density fluctuations and an observable gravity wave spectrum in some cases, where in the simplest case it reproduces a spectrum similar to slow-roll models of inflation. We also find the model provides a reasonable reheating temperature after inflation ends. This type of model may also be relevant for addressing the smallness of the vacuum energy today.Comment: 13 pages, 4 figures, published versio

Broad P V Absorption in the BALQSO, PG 1254+047: Column Densities, Ionizations and Metal Abundances in BAL Winds

This paper discusses the detection of P V 1118,1128 and other broad absorption lines (BALs) in archival HST spectra of the low-redshift BALQSO, PG 1254+047. The P V identification is secured by excellent redshift and profile coincidences with the other BALs, such as C IV 1548,1550 and Si IV 1393,1403, and by photoionization calculations showing that other lines near this wavelength, e.g. Fe III 1123, should be much weaker than P V. The observed BAL strengths imply that either 1) there are extreme abundance ratios such as [C/H] >~ +1.0, [Si/H] >~ +1.8 and [P/C] >~ +2.2, or 2) at least some of the lines are much more optically thick than they appear. I argue that the significant presence of P V absorption indicates severe line saturation, which is disguised in the observed (moderate-strength) BALs because the absorber does not fully cover the continuum source(s) along our line(s) of sight. Computed optical depths for all UV resonance lines show that the observed BALs are consistent with solar abundances if 1) the ionization parameter is at least moderately high, log U >~ -0.6, 2) the total hydrogen column density is log N_H(cm-2) >~ 22.0, and 3) the optical depths in strong lines like C IV and O VI 1032,1038 are >~25 and >~80, respectively. These optical depths and column densities are at least an order of magnitude larger than expected from the residual intensities in the BAL troughs, but they are consistent with the large absorbing columns derived from X-ray observations of BALQSOs. The outflowing BALR, at velocities from -15,000 to -27,000 km/s in PG 1254+047, is therefore a strong candidate for the X-ray absorber in BALQSOs.Comment: 16 pages (LaTeX) plus 8 pages of figures in one file (pg1254_figs.ps.gz), in press with Ap

Renormalizing the Schwinger-Dyson equations in the auxiliary field formulation of λϕ4\lambda \phi^4 field theory

In this paper we study the renormalization of the Schwinger-Dyson equations that arise in the auxiliary field formulation of the O(N) $\phi^4$ field theory. The auxiliary field formulation allows a simple interpretation of the large-N expansion as a loop expansion of the generating functional in the auxiliary field $\chi$, once the effective action is obtained by integrating over the $\phi$ fields. Our all orders result is then used to obtain finite renormalized Schwinger-Dyson equations based on truncation expansions which utilize the two-particle irreducible (2-PI) generating function formalism. We first do an all orders renormalization of the two- and three-point function equations in the vacuum sector. This result is then used to obtain explicitly finite and renormalization constant independent self-consistent S-D equations valid to order~1/N, in both 2+1 and 3+1 dimensions. We compare the results for the real and imaginary parts of the renormalized Green's functions with the related \emph{sunset} approximation to the 2-PI equations discussed by Van Hees and Knoll, and comment on the importance of the Landau pole effect.Comment: 20 pages, 10 figure

Stars In Other Universes: Stellar structure with different fundamental constants

Motivated by the possible existence of other universes, with possible variations in the laws of physics, this paper explores the parameter space of fundamental constants that allows for the existence of stars. To make this problem tractable, we develop a semi-analytical stellar structure model that allows for physical understanding of these stars with unconventional parameters, as well as a means to survey the relevant parameter space. In this work, the most important quantities that determine stellar properties -- and are allowed to vary -- are the gravitational constant $G$, the fine structure constant $\alpha$, and a composite parameter $C$ that determines nuclear reaction rates. Working within this model, we delineate the portion of parameter space that allows for the existence of stars. Our main finding is that a sizable fraction of the parameter space (roughly one fourth) provides the values necessary for stellar objects to operate through sustained nuclear fusion. As a result, the set of parameters necessary to support stars are not particularly rare. In addition, we briefly consider the possibility that unconventional stars (e.g., black holes, dark matter stars) play the role filled by stars in our universe and constrain the allowed parameter space.Comment: accepted to JCAP, 29 pages, 6 figure

Modes of Multiple Star Formation

This paper argues that star forming environments should be classified into finer divisions than the traditional isolated and clustered modes. Using the observed set of galactic open clusters and theoretical considerations regarding cluster formation, we estimate the fraction of star formation that takes place within clusters. We find that less than 10% of the stellar population originates from star forming regions destined to become open clusters, confirming earlier estimates. The smallest clusters included in the observational surveys (having at least N=100 members) roughly coincide with the smallest stellar systems that are expected to evolve as clusters in a dynamical sense. We show that stellar systems with too few members N < N_\star have dynamical relaxation times that are shorter than their formation times (1-2 Myr), where the critical number of stars N_\star \approx 100. Our results suggest that star formation can be characterized by (at least) three principal modes: I. isolated singles and binaries, II. groups (N<N_\star), and III. clusters (N>N_\star). Many -- if not most -- stars form through the intermediate mode in stellar groups with 10<N<100. Such groups evolve and disperse much more rapidly than open clusters; groups also have a low probability of containing massive stars and are unaffected by supernovae and intense ultraviolet radiation fields. Because of their short lifetimes and small stellar membership, groups have relatively little effect on the star formation process (on average) compared to larger open clusters.Comment: accepted to The Astrophysical Journa