47 research outputs found

    Perturbations of Spatially Closed Bianchi III Spacetimes

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    Motivated by the recent interest in dynamical properties of topologically nontrivial spacetimes, we study linear perturbations of spatially closed Bianchi III vacuum spacetimes, whose spatial topology is the direct product of a higher genus surface and the circle. We first develop necessary mode functions, vectors, and tensors, and then perform separations of (perturbation) variables. The perturbation equations decouple in a way that is similar to but a generalization of those of the Regge--Wheeler spherically symmetric case. We further achieve a decoupling of each set of perturbation equations into gauge-dependent and independent parts, by which we obtain wave equations for the gauge-invariant variables. We then discuss choices of gauge and stability properties. Details of the compactification of Bianchi III manifolds and spacetimes are presented in an appendix. In the other appendices we study scalar field and electromagnetic equations on the same background to compare asymptotic properties.Comment: 61 pages, 1 figure, final version with minor corrections, to appear in Class. Quant. Gravi

    CLP1 Founder Mutation Links tRNA Splicing and Maturation to Cerebellar Development and Neurodegeneration

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    SummaryNeurodegenerative diseases can occur so early as to affect neurodevelopment. From a cohort of more than 2,000 consanguineous families with childhood neurological disease, we identified a founder mutation in four independent pedigrees in cleavage and polyadenylation factor I subunit 1 (CLP1). CLP1 is a multifunctional kinase implicated in tRNA, mRNA, and siRNA maturation. Kinase activity of the CLP1 mutant protein was defective, and the tRNA endonuclease complex (TSEN) was destabilized, resulting in impaired pre-tRNA cleavage. Germline clp1 null zebrafish showed cerebellar neurodegeneration that was rescued by wild-type, but not mutant, human CLP1 expression. Patient-derived induced neurons displayed both depletion of mature tRNAs and accumulation of unspliced pre-tRNAs. Transfection of partially processed tRNA fragments into patient cells exacerbated an oxidative stress-induced reduction in cell survival. Our data link tRNA maturation to neuronal development and neurodegeneration through defective CLP1 function in humans

    تطوير المواد الدراسية في تعليم مهارة الكتاب في برنامج الخاض لتعليم اللغة العربية في جامعة مولانا مالك ابراهم الإسلامية الحكومية مالانج

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    ABSTRAK Perkembangan Universitas Islam Negeri Maulana Malik Ibrahim Malang sebagai salah satu Perguruan Tinggi Islam yang berkembang pesat membutuhkan terobosan- terobosan yang handal. Salah satu hal penting yang tidak bisa dipisahkan adalah peranan penting dari PKPBA (Program Khusus Pengembangan Bahasa Arab). PKPBA sebagai sebuah unit pengembangan bahasa, telah berperan penting dalam membantu meningkatkan kemampuan berbahasa mahasiswa khususnya bahasa arab. Banyak dari mahasiswa yang pertama kali masuk PKPBA belum mengetahui bahasa Arab. Namun setelah belajar di PKPBA mereka mampu mengenal ilmu bahasa arab. Namun, tidak hanya berhenti pada mengetahui bahasa arab saja, program ini juga berupaya agar semua mahasiswa mampu untuk menguasai salah satu dari 4 ketrampilan bahasa yakni ketrampilan menulis. Tujuan dari peneliyian ini adalah untuk melengkapi proses pengembangan penyusunan materi ajar menulis dan mengetahui ke-efektifan materi yang dikembangkan. Penelitian ini menggunakan prosedur eksperimen dimana peneliti mendisain Pre-test dan Postest terhadap dua kelompok yakni kelompok eksperimen dan kelompok kontrol. Hasil penelitian ini adalah bahwa pembelajaran ketrampilan menulis dengan menggunakan buku ajar lebih efektif dari pada tanpa menggunakan buku ajar. Dengan indikasi bahwa t-test kelas eksperimen (J3) lebih efektif dengan indikasi bahwa t-test kelas kontrol adalah 3,4. dimana hasil ini lebih besar dari pada tingkat t-table 5% 2,059 dan tingkat 1% 2,787. Dari hasil ini menunjukan bahwa pengajaran menulis bahasa Arab efektif dengan menggunakan materi ajar yang telah disusun oleh peneliti. Hasil penelitian ini adalah: (1) Penyusunan materi ajar untuk PKPBA dimulai dengan membatasi tujuan pengajaran, kemudian menentukan pembagian materi sesuai dengan jumlah hari yang digunakan untuk pembelajaran dalam satu minggu. (2) Pembelajaran menulis bahasa Arab dengan menggunakan Materi ajar ini dinyatakan efektif. Dari hasil yang disebutkan diatas, sudah semestinya materi pengajaran menulis bahasa Arab dapat dimanfaatkan dengan benar dalam proses pengajaran, selain itu penulis berharap agar penelitian ini menjadi referensi untuk penelitian lanjutan yang berhubungan dengan penelitian ini sehingga dapat dikembangkan ke dalam desain materi ajar menulis untuk tingkat selanjutnya. ABSTRACT The expansion of State Islamic University Maulana Malik Ibrahim need some powerful breakthrough. One of the important things is the role of Intensive Arabic Program as unit for improving Arabic, have played an important for helping Arabic language improvement. Most of the students when the first time they enter to this Program, they haven’t yet Arabic knowledge. But after studying in this program for several months they could understand about Arabic. But is not enough in knowing the Arabic only, but this program also try to make all students are mastering one of these four skills, that is writing skill. This research aims at designing process of writing teaching material and finding out the effectiveness of writing teaching material using in Intensive Arabic Program of State Islamic University of Maulana Malik Ibrahim Malang. This research uses the experimental method that the researcher design pre-test and post-test for both groups (Experiment and Control group). This research reach the degree of t-test 3,4 this biggest than t-table at the level of 5% (2,059) and at the level 1% (2,787). This indicates that the use of writing Teaching Material in Arabic for improving writing skill is effective. And the result of this research are obtained bellow: (1) Preparing this teaching material process started by determining the goals, finding out the learning material based on the days in a week which used for teaching (2) The use of writing Teaching Material in Arabic for improving writing skill is effective. Based on these results, teaching material must be used as good as possible in teaching process. Besides, the researcher hopes that the research becomes the reference for further researchers which have a relation with this chapter and could be developed to other teaching material for advance grade

    Recurrent somatic mutations in POLR2A define a distinct subset of meningiomas

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    RNA polymerase II mediates the transcription of all protein-coding genes in eukaryotic cells, a process that is fundamental to life. Genomic mutations altering this enzyme have not previously been linked to any pathology in humans, which is a testament to its indispensable role in cell biology. On the basis of a combination of next-generation genomic analyses of 775 meningiomas, we report that recurrent somatic p.Gln403Lys or p.Leu438_His439del mutations in POLR2A, which encodes the catalytic subunit of RNA polymerase II (ref. 1), hijack this essential enzyme and drive neoplasia. POLR2A mutant tumors show dysregulation of key meningeal identity genes including WNT6 and ZIC1/ZIC4. In addition to mutations in POLR2A, NF2, SMARCB1, TRAF7, KLF4, AKT1, PIK3CA, and SMO4 we also report somatic mutations in AKT3, PIK3R1, PRKAR1A, and SUFU in meningiomas. Our results identify a role for essential transcriptional machinery in driving tumorigenesis and define mutually exclusive meningioma subgroups with distinct clinical and pathological features

    Genotype-phenotype investigation of 35 patients from 11 unrelated families with camptodactyly-arthropathy-coxa vara-pericarditis (CACP) syndrome

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    BackgroundThe camptodactyly-arthropathy-coxa vara-pericarditis syndrome (CACP) is a rare autosomal recessive condition characterized by camptodactyly, noninflammatory arthropathy, coxa vara, and pericarditis. CACP is caused by mutations in the proteoglycan 4 (PRG4) gene, which encodes a lubricating glycoprotein present in the synovial fluid and at the surface of articular cartilage
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