45 research outputs found
Poligami dalam Hukum Islam dan Hukum Positif Indonesia Serta Urgensi Pemberian Izin Poligam di Pengadilan Agama
Penulisan artikel ini bertujuan untuk mengetahui dasar hukum berpoligami dalam hukum islam maupun hukum positif di Indonesia serta mengetahui bagaimana urgensi pemberian izin berpoligami di Pengadilan Agama. Dalam tulisan ini menggunakan pendekatan yuridis normatif dengan berbagai teori interpretasi. Pengadilan Agama merupakan lembaga peradilan dibawah Mahkamah Agung yang sangat penting dalam menangani permasalahan mengenai sengketa yang berhubungan dengan agama Islam. Mulai dari perkawinan, kewarisan, wasiat, hibah, wakaf, zakat, infak, sedekah, sampai ekonomi syariah menjadi tugas dan wewenang dari Pengadilan Agama yang sesuai dengan Pasal 49 dan 50 UU No.7 Tahun 1989 tentang Pengadilan Agama yang telah diamandemen dengan UU No.3 Tahun 2006. Dalam Pasal 4 ayat (1) UU No. 1 Tahun 1974 tentang Perkawinan, apabila seorang suami ingin beristri lebih dari seorang maka wajib mengajukan permohonan kepada Pengadilan di daerah tempat tinggalnya (yaitu Pengadilan Agama). Diatur pula dalam pasal-pasal berikutnya dalam pengajuan poligami harus memenuhi syarat-syarat yang sudah ditentukan menurut UU Perkawinan. Pengaturan tentang poligami di hukum positif seakan mempersulit suami untuk poligami, sedangkan hukum islam sendiri tidak terlalu mempersulit seorang suami untuk poligami. Oleh karena itu kedua hukum ini harus saling sinkron agar tidak menimbulkan suatu permasalahan dalam perkawinan khususnya poligami
Going Vertical To Improve the Accuracy of Atomic Force Microscopy Based Single-Molecule Force Spectroscopy
Single-molecule
force spectroscopy (SMFS) is a powerful technique
to characterize the energy landscape of individual proteins, the mechanical
properties of nucleic acids, and the strength of receptor–ligand
interactions. Atomic force microscopy (AFM)-based SMFS benefits from
ongoing progress in improving the precision and stability of cantilevers
and the AFM itself. Underappreciated is that the accuracy of such
AFM studies remains hindered by inadvertently stretching molecules
at an angle while measuring only the vertical component of the force
and extension, degrading both measurements. This inaccuracy is particularly
problematic in AFM studies using double-stranded DNA and RNA due to
their large persistence length (<i>p</i> ≈ 50 nm),
often limiting such studies to other SMFS platforms (<i>e.g.</i>, custom-built optical and magnetic tweezers). Here, we developed
an automated algorithm that aligns the AFM tip above the DNA’s
attachment point to a coverslip. Importantly, this algorithm was performed
at low force (10–20 pN) and relatively fast (15–25 s),
preserving the connection between the tip and the target molecule.
Our data revealed large uncorrected lateral offsets for 100 and 650
nm DNA molecules [24 ± 18 nm (mean ± standard deviation)
and 180 ± 110 nm, respectively]. Correcting this offset yielded
a 3-fold improvement in accuracy and precision when characterizing
DNA’s overstretching transition. We also demonstrated high
throughput by acquiring 88 geometrically corrected force-extension
curves of a single individual 100 nm DNA molecule in ∼40 min
and versatility by aligning polyprotein- and PEG-based protein–ligand
assays. Importantly, our software-based algorithm was implemented
on a commercial AFM, so it can be broadly adopted. More generally,
this work illustrates how to enhance AFM-based SMFS by developing
more sophisticated data-acquisition protocols
Improved Single Molecule Force Spectroscopy Using Micromachined Cantilevers
Enhancing the short-term force precision of atomic force microscopy (AFM) while maintaining excellent long-term force stability would result in improved performance across multiple AFM modalities, including single molecule force spectroscopy (SMFS). SMFS is a powerful method to probe the nanometer-scale dynamics and energetics of biomolecules (DNA, RNA, and proteins). The folding and unfolding rates of such macromolecules are sensitive to sub-pN changes in force. Recently, we demonstrated sub-pN stability over a broad bandwidth (Δ<i>f</i> = 0.01–16 Hz) by removing the gold coating from a 100 μm long cantilever. However, this stability came at the cost of increased short-term force noise, decreased temporal response, and poor sensitivity. Here, we avoided these compromises while retaining excellent force stability by modifying a short (<i>L</i> = 40 μm) cantilever with a focused ion beam. Our process led to a ∼10-fold reduction in both a cantilever’s stiffness and its hydrodynamic drag near a surface. We also preserved the benefits of a highly reflective cantilever while mitigating gold-coating induced long-term drift. As a result, we extended AFM’s sub-pN bandwidth by a factor of ∼50 to span five decades of bandwidth (Δ<i>f</i> ≈ 0.01–1000 Hz). Measurements of mechanically stretching individual proteins showed improved force precision coupled with state-of-the-art force stability and no significant loss in temporal resolution compared to the stiffer, unmodified cantilever. Finally, these cantilevers were robust and were reused for SFMS over multiple days. Hence, we expect these responsive, yet stable, cantilevers to broadly benefit diverse AFM-based studies