5,895 research outputs found
Magnetic dips in the solar wind
Using magnetic data from the HELIOS 1 fluxgate magnetometer, with a 0.2 sec resolution, the structures of several interplanetary discontinuities involving magnetic dips and rotations of the magnetic field vector were investigated. A minimum variance analysis illustrates the behavior of the magnetic field through the transition in the plane of its maximum variation. Using this analysis, quite different structures have been individuated and, in particular, narrow transitions resembling almost one dimensional reconnected neutral sheets. For the thinner cases (scale lengths of the magnetic rotation of the order or smaller than 1,000 km), results show the observed structures could be the nonlinear effect of a resistive tearing mode instability having developed on an originally one dimensional neutral sheet at the solar corona
Profil Kemampuan Siswa SMA dalam Menyelesaikan Soal Uji Kompetensi Laboratorium (Ukl) pada Kegiatan Pekan Raya Biologi (Prb) 2016
The purpose of this research is to know the profile of the ability of high school students in resolving the question of Competence of the laboratory (UKL) on the activities of the Fairgrounds in biology (PRB) 2016. This research was carried out on the campus of Biology education FKIP University of Riau and junior school in Soweto who follow Fair Biology (PRB) in January to March 2017. The sample in this research are all participants Competence laboratory (UKL), which amounted to 79 people. Techniques in determination of the sample are the total sampling. Data collection instruments used in the form of a question and answer sheet student participants UKL. Parameters measured is the ability based on cognitive and psychomotor domains of students. The results showed the ability of high school students in resolving the question of Competence of the laboratory based on the cognitive domain is on the criteria is not good with average 13.8% and 10.5% in the psychomotor domain. The conclusions of the study results is a profile of the ability of high school students in resolving the question of Competence of the laboratory (UKL) on the activities of the Fairgrounds in biology (PRB) 2016 is less good
Numerical Implementation of lepton-nucleus interactions and its effect on neutrino oscillation analysis
We discuss the implementation of the nuclear model based on realistic nuclear
spectral functions in the GENIE neutrino interaction generator. Besides
improving on the Fermi gas description of the nuclear ground state, our scheme
involves a new prescription for selection, meant to efficiently enforce
energy momentum conservation. The results of our simulations, validated through
comparison to electron scattering data, have been obtained for a variety of
target nuclei, ranging from carbon to argon, and cover the kinematical region
in which quasi elastic scattering is the dominant reaction mechanism. We also
analyse the influence of the adopted nuclear model on the determination of
neutrino oscillation parameters.Comment: 19 pages, 35 figures, version accepted by Phys. Rev.
Electron-vibron coupling in suspended carbon nanotube quantum dots
Motivated by recent experiments, we investigate the electron-vibron coupling
in suspended carbon nanotube quantum dots, starting with the electron-phonon
coupling of the underlying graphene layer. We show that the coupling strength
depends sensitively on the type of vibron and is strongly sample dependent. The
coupling strength becomes particularly strong when inhomogeneity-induced
electronic quantum dots are located near regions where the vibronic mode is
associated with large strain. Specifically, we find that the longitudinal
stretching mode and the radial breathing mode are coupled via the strong
deformation potential, while twist modes couple more weakly via a mechanism
involving modulation of the electronic hopping amplitudes between carbon sites.
A special case are bending modes: for symmetry reasons, their coupling is only
quadratic in the vibron coordinate. Our results can explain recent experiments
on suspended carbon nanotube quantum dots which exibit vibrational sidebands
accompanied by the Franck-Condon blockade with strong electron-vibron coupling
Profile of Student Metacognition Skill at SMPN 23 Pekanbaru Class VIII in Sains Biology Learning Academic Year 2014/2015
The aim of this research is to provide an overview of student's metacognition skill profiles atSMPN 23 Pekanbaru academic year 2014/2015. This research was performed on 17th to 28th November 2014. The sample in this research is class VIII as many as 108 students were selected through stratified sampling technique. The data collection instruments used were a closed questionnaire and interview. Closed questionnaire consists of 35 items statements divided into 5 indicator metacognition skills, namely designing learning activities (Planning), selecting and learning strategies (Management Strategies), guarding the learning strategies (Monitoring), a combination of learning strategies (Debugging) and Evaluating learning strategies (Evaluation). The whole point questionnaire covered otherwise valid and reliable. The collected data were analyzed descriptive. Picture of student's metacognition skills of SMPN 23 Pekanbaru obtained as follows: metacognition abilities of students in designing learning strategies (Planning) has developed differently with a score of metacognition 73, metacognition skills of students in selecting and using learning strategies ( Management Strategies) developed very well expressed by a score of metacognition 81, the ability to monitor student's metacognition learning strategies (Monitoring) has developed differently with a score of metacognition 73, student's metacognition skills in combining different learning strategies (Debugging) expressed always very good with metacognition score of 81 in the assessment of the ability of metacognition learning strategies student's (Evaluation) declared progressing well with a score of 79. Overall, the metacognition scores of students is 77, then student's metacognition skill profiles of SMPN 23 Pekanbaru class VIII in Biology Science Education declared the school year 2014/2015 is growing very well
Penerapan Model Problem Based Learning pada Mata Pelajaran IPA terhadap Peningkatan Keterampilan Berpikir Kreatif dan Hasil Belajar Peserta Didik Kelas VII Hang Tuah SMP Negeri 1 Pekanbaru Tahun Ajaran 2015/2016
This research aimed to improve creative thinking skill and student's achievement of student class VII Hang Tuah SMP Negeri 1 Pekanbaru by implementation Problem Based Learning model. It had been done in SMP Negeri 1 Pekanbaru on April-May 2016. Parameters measure were student's creative thinking skill, studen't achievement and student's attitude. The methods of this research was classroom action research by implementation Problem Based Learning model. It had been done in two cylce. There were planning step, acting step, observation step and reflection step for each cycle. The research instrument used was a learning device that consist of a lesson plan, syllabus, assesment authentic sheet, observation sheet and creative thinking skill sheet. The collected data was analysed descriptively. The result of this research showed that creative thinking skill on first cycle was 86,89 (C) and increased on second cycle up to 96,19 (A). Student'achievement on first cycle was 90,62 (B) and increased on second cycle up to 96,48 (A). Classical completeness percentage on both of cycle was 100%. Student's attitude on first cycle was 87,45 (C) and increased on second cycle up to 93,14 (B). It can be conclude that Problem Based Learning model can improve creative thingking skill and student's achievement of student class VII Hang Tuah SMP Negeri 1 Pekanbaru
Androgen receptor mutations in prostate cancer
We analyzed the frequency and relevance of mutations in the coding region of the androgen receptor (AR) in genomic DNA extracted from 137 specimens of prostate cancer. The specimens were obtained from the primary tumors of patients affected by stage B disease [15 nonmicrodissected (group 1A) and 84 microdissected (group 1B)] and from the metastatic deposits of individuals with stage D1 disease [8 nonmicrodissected (group 2A) and 30 microdissected (group 2B)] who had not undergone androgen ablation therapy. The study was conducted by PCR-single strand conformational polymorphism (SSCP) analysis of exons 2-8 in the four groups and direct sequence analysis of exon 1 in group 1B. As positive and negative controls, we used genomic DNA extracted from genital skin fibroblasts of patients affected by various forms of androgen resistance with known mutations in the AR. To control for genetic instability, PCR-SSCP analysis of exon 2 of the human progesterone receptor was carried out on each specimen. The overall number of mutations detected was 11 (8%). No mutations were detected in any of the 99 patients with stage B disease. Eleven mutations were detected in exons 2-8 in 8 of the 38 patients with stage D1 disease (all in group 2B). Simultaneous analysis of exon 2 of the progesterone receptor was carried out, and no SSCP changes were identified. These data suggest that AR mutations are rare and presumably do not play a role in the initial phase of prostatic carcinogenesis. The presence of a significant number of AR mutations in metastatic disease indicates that mutations of this molecule may play a role in the most advanced phases of the natural history of this disease, either by facilitating growth or acquisition of the metastatic phenotype
- …