Analisis Kesalahan Siswa kelas IV dalam Menyelesaikan Soal cerita Materi Pecahan di SDN Kolursari 2 Bangil

Salah satu materi yang diajarkan di Sekolah Dasar adalah Pecahan. Pecahan adalah salah satu materi yang harus dipahami siswa. Banyak pula kendala yang harus dilakukan oleh siswa agar memahami materi pecahan. Salah satunya yang terjadi di SDN Kolursari 2 Bangil terdapat beberapa siswa yang melakukan kesalahan konsep maupun operasi hitung yang menyebabkan terjadinya hasil dari ujian tengah semesternya kurang baik. Apalagi dalam masalah menyelesaikan materi pecahan. Penelitian ini merupakan penelitian deskriptif kualitatif yang bertujuan untuk mendeksripsikan jenis dan faktor penyebab kesalahan yang dilakukan pada siswa SD kelas IV. Subjek penelitian ini terdiri dari 20 siswa kelas IV SDN Kolursari 2 Kecamatan Bangil Kabupaten Pasuruan. Teknik pengumpulan data diambil dari mengumpulkan soal UTS semester ganjil yang ditentukan berdasarkan banyaknya kesalahan yang diketahui melalui tiap butir soal.Dari hasil analisis data dapat diperoleh kesimpulan presentase jenis kesalahan yang dilakukan siswa dalam menyelesaikan soal pecahan yaitu kesalahan konsep sebesar 59% dan kesalahan operasi hitung sebesar 41%. Penyebab kesalahan diakibatkan karena (1) kurangnya siswa dalam memahami terhadap konsep dasar pecahan senilai (2) kurang teliti dalam menghitung (3) kurang teliti dalam menyelesaikan soal (4) belum begitu hafal perkalian dan pembagian bilangan (5) tidak memahami konsep dasar operasi penjumlahan, pengurangan

Optically Pure Diphenoxy Derivatives as More Flexible Probes for β‑Amyloid Plaques

The highly rigid and planar scaffold with π-conjugated systems has been widely considered to be indispensable for Aβ binding probes. However, the flexible benzyloxybenzene derivative [¹²⁵I]­BOB-<b>4</b> represents an excellent lead candidate for targeting Aβ in AD brains. Based on that, we designed two pairs of more flexible and optically pure diphenoxy derivatives with a chiral center as novel Aβ probes. These compounds possessed high affinity (<i>K</i>_i = 15.8–45.0 nM) for Aβ_1–42 aggregates, and (<i>R</i>)-enantiomers showed slightly better binding ability than (<i>S</i>)-enantiomers. In addition, the competition binding assay implied that the optically pure diphenoxy derivatives with more flexible geometry shared the same binding site as IMPY, a classical rigid and planar Aβ probe. For ¹²⁵I-radiolabeled enantiomers, (<i>S</i>)-[¹²⁵I]<b>5</b> and (<i>R</i>)<b>-</b>[¹²⁵I]<b>5</b>, specific plaque labeling on brain sections of Tg mice and AD patients were observed in <i>in vitro</i> autoradiography, persuasively proving the excellent affinity of the probes. In biodistribution, (<i>S</i>)-[¹²⁵I]<b>5</b> and (<i>R</i>)<b>-</b>[¹²⁵I]<b>5</b> with relatively low lipophilicity exhibited moderate initial brain uptake (4.37% and 3.72% ID/g at 2 min, respectively) and extremely fast washout from normal mice brain (brain_2min/brain_60min = 19.0 and 17.7, respectively). In summary, the separate enantiomers displayed similar properties <i>in vitro</i> and <i>in vivo</i>, and (<i>S</i>/<i>R</i>)-[¹²³I]<b>5</b> may be potential SPECT probes for recognizing Aβ plaques in AD brains

Towards understanding what contributes to forming an opinion

Opinion evolution mechanism can be captured by physical modeling. In this paper, a kinetic equation is established by defining a generalized displacement(cognitive level), a driving force and the related factors such as generalized potential, information quantity and attitude. It has been shown that the details of opinion evolution depend on the type of the driving force, self-dominated driving or environment-dominated driving. In the former case, the participants can have their attitudes changed in the process of competition between the self-driving force and environment-driving force. In the latter case, all of the participants are pulled by the environment. Some regularities behind the dynamics of opinion are also revealed, for instance, the information entropy decays with time in a special way, etc. The results may help us to get some deep understanding for the formation of a public opinion.</p

Table1.docx

<p>Oaks are important timber trees with wide distributions in China, but few genetic studies have been conducted on a fine scale. In this study, we seek to investigate the genetic diversity and differentiation of three sympatric oak species (Quercus aliena Blume, Quercus dentata Thunb. ex Murray, and Quercus variabilis Blume) in their northern distribution in China using 17 bi-parentally inherited nSSRs markers and five maternally inherited chloroplast DNA (cpDNA) fragments. Both the cpDNA and the nSSRs show a high level of genetic differentiation between different oak sections. The chloroplast haplotypes are clustered into two lineages. Clear species boundaries are detected between Q. variabilis and either Q. aliena or Q. dentata. The sharing of chloroplast haplotype H1 between Q. aliena and Q. dentata suggests very recent speciation and incomplete lineage sorting or introgression of H1 from one species to another. The nSSRs data indicate a complete fixation of variation within sites for all three oak species, and that extensive gene flow occurs within species whereas only limited gene flow is detected between Q. aliena and Q. dentata and nearly no gene flow can be detected between Q. aliena and Q. variabilis and between Q. dentata and Q. variabilis. Prezygotic isolation may have contributed to the species boundaries of these three sympatric oak species.</p

Association between Polymorphisms in XRCC1 Gene and Treatment Outcomes of Patients with Advanced Gastric Cancer: A Systematic Review and Meta-Analysis

<div><p>Background</p><p>Many reports have shown inconsistent results on the relationship between single nucleotide polymorphisms (SNPs) of X-ray repair cross complementing protein (XRCC1) gene and platinum-based chemotherapeutic efficacy. This meta-analysis aimed to summarize published data about the association between two SNPs of XRCC1 (Arg194Trp and Arg399Gln) and treatment outcomes of patients with advanced gastric cancer.</p><p>Methodology/Principal Findings</p><p>We retrieved the relevant articles from MEDLINE, Web of Knowledge, and the China National Knowledge Infrastructure (CNKI) databases. Studies were selected according to specific inclusion and exclusion criteria. Study quality was assessed according to the guidelines outlined by Hayden, et al. and PRISMA guidelines. We estimated the odds ratio (OR) for response rate versus no response after platinum-based chemotherapy. Progression-free survival (PFS) and overall survival (OS) were evaluated by pooled Cox proportional hazard ratios (HRs) and 95% confidence intervals (CIs). We found that none of the XRCC1 Arg194Trp and Arg399Gln polymorphisms was significantly associated with tumor response. Stratified analysis by ethnicity or sensitivity analysis also showed that XRCC1 SNPs were not related with chemotherapy response. Patients with minor variant A allele were likely to have poorer 2-year survival rate than those with G/G genotype. However, in the group of 5-year follow up, there was no significant association between the A allele and OS yet.</p><p>Conclusions/Significance</p><p>There is no evidence to support the use of XRCC1 Arg194Trp and Arg399Gln polymorphisms as prognostic predictors of TR and PFS in gastric patients treated with platinum-based chemotherapy. The relationship between minor variant A allele and OS requires further verification.</p></div

Quality assessment of included studies.

<p>Abbreviation: PFS: progression-free survival; OS: overall survival; Y: yes; P: partly; N: no; U: unsure.</p

Additional file 2: of Integrated pipeline for inferring the evolutionary history of a gene family embedded in the species tree: a case study on the STIMATE gene family

STIM gene family and orthologous gene trees. (PDF 403 kb

The screening process of studies.

<p>The screening process of studies.</p

Forest plots of PFS in AGC patients treated with chemotherapy by XRCC1 Arg399Gln polymorphism: G/A or A/A vs. G/G.

<p>Forest plots of PFS in AGC patients treated with chemotherapy by XRCC1 Arg399Gln polymorphism: G/A or A/A vs. G/G.</p

Stratified analysis of the association between XRCC1 Arg399Gln and response rate.

<p>Abbreviation: <i>P1</i>, p value for difference; <i>P2</i>, p value for heterogeneity.</p