Pengaruh Pendekatan Pembelajaran Matematika Realistik Terhadap Prestasi Belajar Matematika Ditinjau Dari Kemampuan Numerik Siswa Kelas VIII SMP Negeri 2 Amlapura

Penelitian ini bertujuan untuk mengetahui dan mendeskripsikan pengaruh pendekatan pembelajaran matematika realistik terhadap prestasi belajar matematika ditinjau dari kemampuan numerik siswa. Penelitian ini merupakan eksperimen semu dilaksanakan dengan menggunakan rancangan the post test only control group design. Populasinya adalah seluruh siswa kelas VIII SMP Negeri 2 Amlapura tahun pelajaran 2013-2014. Dari delapan kelas yang ada, empat kelas dipilih sebagai sampel yakni dua kelas sebagai kelas eksperimen dan dua kelas sebagai kelas kontrol yang diambil dengan teknik random. Data penelitian dikumpulkan menggunakan tes, yaitu tes kemampuan numerik dan tes prestasi belajar matematika. Data yang diperoleh dianalisis dengan analisis varians dua jalur dilanjutkan dengan uji Tukey. Berdasarkan hasil analisis data dan pembahasan, dapat disimpulkan, terdapat perbedaan yang signifikan prestasi belajar matematika antara siswa yang mengikuti pendekatan pembelajaran matematika realistik dengan siswa yang mengikuti pendekatan pembelajaran konvensional. Terdapat pengaruh interaksi antara pendekatan pembelajaran matematika realistik dan kemampuan numerik terhadap prestasi belajar matematika. Pada Siswa yang memiliki kemampuan numerik tinggi, prestasi belajar matematika siswa yang mengikuti pendekatan pembelajaran matematika realistik lebih baik daripada pendekatan konvensional. Pada siswa yang memiliki kemampuan numerik rendah, prestasi belajar matematika siswa yang mengikuti pendekatan pembelajaran matematika realistik tetap lebih tinggi dari siswa yang mengikuti pendekatan pembelajaran konvensional.Kata Kunci : pendekatan pembelajaran matematika realistik, kemampuan numerik, dan prestasi belajar matematika The study aimed at finding out and describing the contribution of realistic mathematic instructional approach towards mathematic learning achievement viewed from numeric skills. It was a quasi-experimental research by utilizing the post test only control group design. The study involved all students class VIII SMP Negeri 2 Amlapura in 2013-2014 as the population. Four classes of the students were chosen from eight parallel classes as the samples consisting of two classes as experimental and another two classes as control groups. They were determined based on random technique. The data were collected by testing, involving numeric ability and mathematic achievement tests. They were analysed based on two tailed variant analysis followed by Tukey-test. The results indicated that there was a significant difference between mathematic learning achievement of the students joining realistic mathematic instruction and those joining a conventional approach. There was an interactional contribution of realistic mathematic instructional approach and numeric ability towards mathematic learning achievement. The students having higher numeric skills, when joining realistic mathematic instruction approach their mathematic learning achievement was found better or higher than those joining a conventional approach. The students having lower numeric skills, when joining realistic mathematic instruction approach, their mathematic learning achievement was found better or higher than those joining a conventional approach

Crossmodal Encoding of Motor Sequence Memories

Background The field of motor rehabilitation is in need of more efficient and effective rehabilitation strategies. Each year, almost 2.5 million Americans suffer from traumatic brain injury (TBI) and roughly 800,000 Americans experience a stroke. 1, 2 The total annual direct and indirect costs of stroke and TBI in the United States are $65.5 billion and between$48 and $56 billion, respectively.3, 4 A promising new approach may lie in using sound as a neuromodulatory tool to access motor areas of the brain. Pianists, for example, can improve their performance of a previously practiced musical piece just by listening to the piece before the next time they play.

Metformin potentiates the effect of arsenic trioxide suppressing intrahepatic cholangiocarcinoma: roles of p38 MAPK, ERK3, and mTORC1

Abstract Background Arsenic trioxide (ATO) is commonly used in the treatment of acute promyelocytic leukemia (APL), but does not benefit patients with solid tumors. When combined with other agents or radiation, ATO showed treatment benefits with manageable toxicity. Previously, we reported that metformin amplified the inhibitory effect of ATO on intrahepatic cholangiocarcinoma (ICC) cells more significantly than other agents. Here, we investigated the chemotherapeutic sensitization effect of metformin in ATO-based treatment in ICC in vitro and in vivo and explored the underlying mechanisms. Methods ICC cell lines (CCLP-1, RBE, and HCCC-9810) were treated with metformin and/or ATO; the anti-proliferation effect was evaluated by cell viability, cell apoptosis, cell cycle, and intracellular-reactive oxygen species (ROS) assays. The in vivo efficacy was determined in nude mice with CCLP-1 xenografts. The active status of AMPK/p38 MAPK and mTORC1 pathways was detected by western blot. In addition, an antibody array was used screening more than 200 molecules clustered in 12 cancer-related pathways in CCLP-1 cells treated with metformin and/or ATO. Methods of genetic modulation and pharmacology were further used to demonstrate the relationship of the molecule. Seventy-three tumor samples from ICC patients were used to detect the expression of ERK3 by immunohistochemistry. The correlation between ERK3 and the clinical information of ICC patients were further analyzed. Results Metformin and ATO synergistically inhibited proliferation of ICC cells by promoting cell apoptosis, inducing G0/G1 cell cycle arrest, and increasing intracellular ROS. Combined treatment with metformin and ATO efficiently reduced ICC growth in an ICC xenograft model. Mechanistically, the antibody array revealed that ERK3 exhibited the highest variation in CCLP-1 cells after treatment with metformin and ATO. Results of western blot confirm that metformin and ATO cooperated to inhibit mTORC1, activate AMP-activated protein kinase (AMPK), and upregulate ERK3. Metformin abrogated the activation of p38 MAPK induced by ATO, and this activity was partially dependent on AMPK activation. Inactivation of p38 MAPK by SB203580 or specific short interfering RNA (siRNA) promoted the inactivation of mTORC1 in ICC cells treated with metformin and ATO. Activation of p38 MAPK may be responsible for resistance to ATO in ICC. The relationship between p38 MAPK and ERK3 was not defined by our findings. Finally, AMPK is a newfound positive regulator of ERK3. Overexpression of EKR3 in ICC cells inhibited cell proliferation through inactivation of mTORC1. ERK3 expression is associated with a better prognosis in ICC patients. Conclusions Metformin sensitizes arsenic trioxide to suppress intrahepatic cholangiocarcinoma via the regulation of AMPK/p38 MAPK-ERK3/mTORC1 pathways. ERK3 is a newfound potential prognostic predictor and a tumor suppressor in ICC

Identifying perfusion deficits on CT perfusion images using temporal similarity perfusion (TSP) mapping

OBJECTIVES: Deconvolution-derived maps of CT perfusion (CTP) data may be confounded by transit delays. We propose temporal similarity perfusion (TSP) analysis to decrease CTP maps' dependence on transit times and investigate its sensitivity to detect perfusion deficits. METHODS: CTP data of acute stroke patients obtained within 9 h of symptom onset was analyzed using a delay-insensitive singular value decomposition method and with TSP. The TSP method applies an iterative process whereby a pixel's highest Pearson's R value is obtained through comparison of a pixel's time-shifted signal density time-series curve and the average whole brain signal density time-series curve. Our evaluation included a qualitative and quantitative rating of deconvolution maps (MTT, CBV, and TTP), of TSP maps, and of follow-up CT. RESULTS: Sixty-five patients (mean 68 (SD 13) years, 34 male) were included. A perfusion deficit was identified in 90%, 86%, 65%, and 84% of MTT, TTP, CBV, and TSP maps. The agreement of MTT, TTP, and TSP with CT follow-up was comparable but noticeably lower for CBV. CBV had the best relationship with final infarct volume (R2 = 0.77, p < 0.001), followed by TSP (R2 = 0.63, p < 0.001). Intra-rater agreement of an inexperienced reader was higher for TSP than for CBV/MTT maps (kappa's of 0.79-0.84 and 0.63-0.7). Inter-rater agreement for experienced readers was comparable across maps. CONCLUSIONS: TSP maps are easier to interpret for inexperienced readers. Perfusion deficits detected by TSP are smaller which may suggest less dependence on transit delays although more investigation is required. KEY POINTS: • Temporal similarity perfusion mapping assesses CTP data based on similarities in signal time-curves. • TSP maps are comparable in perfusion deficit detection to deconvolution maps. • TSP maps are easier to interpret for inexperienced readers