14,271 research outputs found
Assessment of Students Performances in Biology: Implication for Measurements and Evaluation of Learning
Scienceeducation is believed to be a vital tool for individual and societal development at large. The persistent low levels of students' achievement in sciences at the various public examinations in Nigeria have continued to draw the attention of major stakeholders in education. This study examined academic achievement of Senior Secondary School students in biology and gender difference in students' achievement was examined. Ex-post facto design of descriptive research was adopted for the study. A proforma was used to collect data from a sample of two hundred (200) students, selected using stratified random sampling procedure from the Science secondary schools in Kano state Nigeria. The data collected were the students' performances in biology achievement tests. The data were analysed using descriptive statistics and independent-sample t-test. Overall results showed that the test internal consistency reliability is low and unsatisfactory; the students performed below average (M=47.02, SD=16.493 (47%). Similarly, gender difference exists in biology performance with another significant difference between performance of urban and rural school students. The study concludes that, biology test used in Kano state qualifying examinations to assess students potential ability in biology is not a reliable measurement tool and that, academic performance of students in biology is unsatisfactory and evidence of differential performance between gender and schools locations. The implication for measurements and evaluation of learning as well as recommendations has been discussed
Sensor material characterisation for magnetometer application
Pengukuran dan gangguan medan magnet arus terus dan arus ulang-alik memerlukan penderia medan magnet yang mempunyai kepekaan yang tinggi dan stabil. Untuk menghasilkan penderia tersebut, ciri-ciri bahan magnet yang baik telah dikenalpasti. Beberapa jenis bahan magnet yang berbeza telah digunakan untuk mengkaji ciri-ciri dan kesannya terhadap medan magnet. Teras gelang yang diperbuat daripada bahan-bahan magnet tersebut direkabentuk dengan dimensi yang sama bagi membolehkan perbandingan dibuat dengan mudah. Selain itu, rod tunggal dan berkembar juga telah digunakan sebagai teras penderia fluxgate, untuk melihat prestasi setiap jenis penderia tersebut. Kedua-dua penderia tersebut telah diuji dengan menggunakan dua sumber bahan magnet iaitu bar magnet tetap dan solenoid dengan diameter dawai yang berbeza. Isyarat keluaran bagi setiap penderia fluxgate seterusnya diproses bagi mengenalpasti hubungannya dengan ketumpatan medan magnet
Kesan penggunaan koswer multimedia animasi visual terhadap pencapaian pelajar dalam mata pelajaran matematik
Ramai pelajar yang bermasalah dalam topik Pelan dan Dongakan. Ini kerana pelajar sukar untuk membayangkan objek yang tersembunyi melalui proses pengajaran dan pembelajaran (P&P) secara konvensional. Penyelidik telah membangunkan satu koswer multimedia animasi visual dalam topik Pelan dan Dongakan dengan menerapkan kesemua elemen-elemen yang dapat membantu meningkatkan kemahiran visual iaitu elemen animasi, video, audio, grafik dan teks. Seterusnya, kajian kuasi eksperimental ini turut dijalankan bertujuan untuk mengetahui kesan penggunaan koswer multimedia animasi visual terhadap pencapaian pelajar bagi mata pelajaran Matematik di sekolah menengah. Ujian Pra dan Ujian Pos digunakan untuk melihat perbezaan pencapaian yang signifikan selepas menggunakan koswer multimedia animasi visual yang menggunakan teori Kognitif Visual Wiley. Responden yang terlibat dalam kajian ini ialah seramai 40 orang pelajar Tingkatan Lima yang dibahagikan kepada dua kumpulan iaitu kumpulan rawatan dan kumpulan kawalan yang dipilih daripada sebuah sekolah di daerah Batu Pahat, Johor. Hasil analisis menunjukkan peningkatan skor min markah bagi pelajar kumpulan rawatan. Hasil analisis ujian-t (paired-sample-t-test) membuktikan bahawa wujudnya perbezaan skor min markah yang signifikan di antara markah ujian pra dan markah ujian pos bagi kumpulan rawatan. Oleh itu, terdapat perbezaan yang signifikan di antara skor min markah ujian pra dan ujian pos bagi pelajar kumpulan rawatan selepas menggunakan koswer multimedia animasi visual. Manakala instrumen soal selidik yang digunakan untuk melihat tahap penerimaan pelajar selepas menggunakan koswer multimedia animasi visual berdasarkan tiga aspek iaitu aspek isi kandungan, aspek interaksi dan aspek persembahan telah memeperolehi skor min yang tinggi bagi ketiga-tiga aspek tersebut. Dapatan kajian ini menggambarkan penggunaan koswer multimedia animasi visual dapat membantu meningkatkan pencapaian Matematik di dalam bilik darjah terutama yang tidak melibatkan pengiraan
Stroke in Young Adults: A Prospective Study from Northwestern Nigeria
Background. Stroke is an important cause of morbidity and mortality in young adults especially in developing countries. This two-centre prospective study aimed at reviewing the pattern, types, and case fatality of stroke in the young adults in Northwestern part of Nigeria. Methods. Consecutive patients aged 18–40 years admitted to the medical wards of two tertiary hospitals from June 2008 to August 2010 were recruited. Relevant clinical data were obtained from the patients.The survivors were followed up in neurology clinics for 6 months. Results. A total of 71 patients aged 18–40 yrs, (mean age was 31.9 ± 6) comprising 52(73%) males and 19(23%) females were enrolled. Forty two (59.1%) patients had infarctive stroke. The risk factors included hypertension (74.7%) patients, smoking (50.7%), hypercholesterolemia (9.9%), non-hypertensive cardiac diseases (8.5%), HIV (8.5%), diabetes mellitus (4.2%) cocaine and amphetamine (2.8%), and sickle cell disease (2.8%). Only twelve (17%) patients presented within the first 6 hours of onset of stroke. Seventeen (23.9 %) patients died, case fatality in the first 24 and 72 hrs was 4.2% and 19.7%, respectively. Conclusion. Our data suggests that stroke in young adults is not as uncommon as previously suggested. Hypertension, smoking, hypercholesterolemia, cardiac diseases and HIV are the most common risk factors
CP-odd Phase Correlations and Electric Dipole Moments
We revisit the constraints imposed by electric dipole moments (EDMs) of
nucleons and heavy atoms on new CP-violating sources within supersymmetric
theories. We point out that certain two-loop renormalization group corrections
induce significant mixing between the basis-invariant CP-odd phases. In the
framework of the constrained minimal supersymmetric standard model (CMSSM), the
CP-odd invariant related to the soft trilinear A-phase at the GUT scale,
theta_A, induces non-trivial and distinct CP-odd phases for the three gaugino
masses at the weak scale. The latter give one-loop contributions to EDMs
enhanced by tan beta, and can provide the dominant contribution to the electron
EDM induced by theta_A. We perform a detailed analysis of the EDM constraints
within the CMSSM, exhibiting the reach, in terms of sparticle spectra, which
may be obtained assuming generic phases, as well as the limits on the CP-odd
phases for some specific parameter points where detailed phenomenological
studies are available. We also illustrate how this reach will expand with
results from the next generation of experiments which are currently in
development.Comment: 31 pages, 21 eps figures; v2: additional remarks on 2-loop threshold
corrections and references added; v3: typos corrected, to appear in Phys.
Rev.
WHO Takes Action to Promote the Health of Refugees and Migrants
Migration is a defining issue of our time, with 1 billion migrants globally, of whom 258 million have crossed borders. Climate change and political instability propel ever-greater displacement, with major detriments to health. Policies that fail to prevent human trafficking or guarantee essential services undermine Universal Health Coverage (UHC) and the global pledge to “leave no one behind.” The World Health Assembly should robustly implement WHO’s Global Action Plan (GAP) on the Health of Refugees and Migrants.ugees and Migrants
Quantum states in a magnetic anti-dot
We study a new system in which electrons in two dimensions are confined by a
non homogeneous magnetic field. The system consists of a heterostructure with
on top of it a superconducting disk. We show that in this system electrons can
be confined into a dot region. This magnetic anti-dot has the interesting
property that the filling of the dot is a discrete function of the magnetic
field. The circulating electron current inside and outside the anti-dot can be
in opposite direction for certain bound states. And those states exhibit a
diamagnetic to paramagnetic transition with increasing magnetic field. The
absorption spectrum consists of many peaks, some of which violate Kohn's
theorem, and which is due to the coupling of the center of mass motion with the
other degrees of freedom.Comment: 6 pages, 12 ps figure
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