extreme sampling
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2020 ◽  
Author(s):  
Shanqun Jiang ◽  
Qianru Cai ◽  
Di Zhang ◽  
Juanlin Fan ◽  
Shengnan Hu ◽  
...  

Aim: We investigated the effect of ABCG1 gene DNA methylation in the lipid-lowering efficacy of simvastatin. Materials & methods: An extreme sampling approach was used to select 211 individuals from the top and bottom 15% of adjusted lipid-lowering response residuals to simvastatin after eight consecutive weeks. DNA methylation was measured before treatment by the MethylTarget bisulfite sequencing method. Results: ABCG1_A DNA methylations were negatively associated with baseline high-density lipoprotein cholesterol (HDL-C) and the change in HDL-C after treatment. ABCG1_C methylations were also related to the change in triglyceride and HDL-C. Moreover, mean ABCG1_A and ABCG1_C methylations explain 7.2% of the ΔTC (total cholesterol) and 17.5% of the ΔHDL-C level variability, respectively. Conclusion: DNA methylations at the ABCG1 gene play significant inhibitory effects in the lipid-lowering therapy of simvastatin.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yi Li ◽  
Orna Levran ◽  
JongJoo Kim ◽  
Tiejun Zhang ◽  
Xingdong Chen ◽  
...  

Abstract It is extremely expensive to conduct large sample size array- or sequencing based genome scale association studies. For a quantitative trait, an extreme case-control study design may improve the power and reduce the cost of variant calling. We investigated the performance of extreme study design when various proportions of samples are selected from the tails of phenotype distribution. Using simulations, we show that when risk genotypes become rare in the population and effect size is relatively small, it is beneficial to carry out an extreme sampling study. In particular, the number of selected cases and controls can even be unbalanced such that power is further increased, compared with a balanced selection. Our application to two data sets: methadone dose data and yearling weight data, demonstrated that similar results for full data analysis can be obtained using extreme sampling with only a fraction of the data. Using power analysis with simulated data and an experimental data application, we conclude that when full data is unavailable due to restricted budget, it is rewarding to employ an extreme sampling design in the sense that there can be immense cost reductions and qualitatively similar power as in the full data analysis.


2018 ◽  
Vol 27 (1) ◽  
pp. 30
Author(s):  
Rattahpinnusa Haresariu Handisa
Keyword(s):  

<p>Minat peneliti untuk memanfaatkan koleksi Perpustakaan Cendana pada Balai Penelitian dan Pengembangan Lingkungan Hidup dan Kehutanan Kupang masih rendah. Penelitian ini bertujuan mengidentifikasi persepsi peneliti terhadap relevansi koleksi perpustakaan dengan kegiatan penelitian, ketersediaan dan kemutahiran koleksi, serta faktor penghambat pengembangan koleksi perpustakaan. Penelitian menggunakan metode studi kasus untuk menggali informasi secara mendalam mengenai persepsi peneliti terhadap koleksi perpustakaan. Pengambilan sampel menggunakan teknik extreme sampling dengan melibatkan informan yang memiliki keterkaitan dengan topik penelitian. Jumlah informan sebanyak tiga orang. Data dikumpulkan melalui wawancara, selanjutnya data yang diperoleh dianalisis secara deskriptif. Hasil penelitian menunjukkan mayoritas informan mempersepsikan koleksi perpustakan cukup relevan dengan kegiatan penelitian. Namun, koleksi perpustakaan belum ideal, khususnya ketersediaan dan kemutakhiran koleksi. Mereka juga mempersepsikan faktor luar seperti keterbatasan pendanaan, fasilitas, dan akses penghambat perpustakaan dalam mengembangkan koleksi yang ideal. Penelitian ini merekomendasikan Perpustakaan Cendana untuk (1) menyusun kebijakan pengembangan koleksi sebagai dasar pengembangan koleksi yang berorientasi kebutuhan pengguna dengan mempertimbangkan aspek relevansi, ketersediaan, dan kemutakhiran; (2)<br />menjalin kerja sama dengan perpustakaan lain dalam rangka meningkatkan ketersediaan dan kemutakhiran koleksi melalui silang layan dan konsorsium.</p>


2018 ◽  
Vol 103 (3) ◽  
pp. 246-251 ◽  
Author(s):  
Long-Fei Wu ◽  
Dong-Cheng Zhu ◽  
Chang-Hua Tang ◽  
Bing Ge ◽  
Ju Shi ◽  
...  

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Indra Darma Sitepu
Keyword(s):  

Tujuan penelitian ini adalah untuk mengetahui  dampak  kecemasan  pada atlet bola basket sebelum memulai pertandingan. Penelitian ini menggunakan metode penelitian kualitatif dengan  pendekatan  studi  kasus.  Penentuan  subjek  dilakukan  dengan  cara  menggunakan teknik extreme sampling. Subjek terdiri dari tiga atlet bola basket yang memiliki kecemasan tinggi dari lima belas atlet bola basket di klub bola basket Angsapura Medan. Teknik pengumpulan data menggunakan wawancara semi terstruktur, observasi non-partisipan, dan dokumentasi.  Hasil  penelitian  ini  adalah  dampak  dari  kecemasan  pada  atlet  bola  basket sebelum bertanding disebabkan oleh gangguan perhatian dan konsentrasi kemudian mempengaruhi  gejala-gejala  psikis lainnya.  Gejala fisik timbul dikarenakan  pengaruh  dari gejala psikis kemudian menimbulkan dampak kecemasan pada atlet bola basket sebelum bertanding.


2016 ◽  
Vol 23 (4) ◽  
pp. 336-344 ◽  
Author(s):  
Kang Li ◽  
Yanhong Liu ◽  
Scott A. Venners ◽  
Yi-Hsiang Hsu ◽  
Shanqun Jiang ◽  
...  

Objectives: To investigate whether LEP G2548A and LEPR Q223R polymorphisms influence serum lipid levels and whether the 2 polymorphisms affect the efficacy of simvastatin treatment in Chinese patients with primary hyperlipidemia. Methods: We used an extreme sampling approach by selecting 212 individuals from the top and bottom 15% of adjusted lipid-lowering response residuals to simvastatin (n = 106 in each group of good or bad response) from a total of 734 samples with primary hyperlipidemia. They were treated with simvastatin orally 20 mg/d. Fasting serum lipids were measured at baseline and after 4 and 8 weeks of treatment. Genotyping was carried out using polymerase chain reaction-restriction fragment length polymorphism. Results: More patients in the good response group (27%) had LEPR Q223R than in the bad response group (16%, P = .046). Secondary stratified analyses showed that patients carrying the RR genotype of the LEPR Q223R gene had significantly higher high-density lipoprotein cholesterol levels than those with the QR genotype at baseline ( P = .034) among good responders. After 29 consecutive days of treatment with simvastatin, patients carrying the RR genotype had a significantly larger decrease in triglycerides (change: −0.74 ± 0.92, P = .036) and total cholesterol levels (change: −1.77 ± 0.68, P = .023) compared with those carrying QR genotype among bad responders. After Bonferroni correction, the results were not statistically significant. Conclusion: LEPR Q223R polymorphism, but not LEP G2548A, could modulate the efficacy of simvastatin in Chinese patients with primary hyperlipidemia.


2011 ◽  
Vol 2 ◽  
Author(s):  
Robert Makowsky ◽  
T. Mark Beasley ◽  
Gary L. Gadbury ◽  
Jeffrey M. Albert ◽  
Richard E. Kennedy ◽  
...  

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