Produktivitas Ayam Buras Hasil Seleksi Berdasarkan Pengetahuan Lokal Peternak

Penggalian potensi ayam buras (kampung) menjadi semakin penting pada kondisikrisis ekonomi seperti sekarang. Hal tersebut menyebabkan kita perlu menengokpotensi yang secara sosial diterima, secara ekonomi terjangkau dan secarateknologis mulai dikembangkan dan mudah diterapkan. Namun di pihak laintingkat produktivitasnya masih rendah karena sistem pemeliharaan danseleksinya yang kurang berkembang. Sistem pengetahuan lokal cara seleksi padamasyarakat pedesaan sebenarnya ada hanya kurang mendapat perhatian danminat para akademisi seperti pengetahuan Catur Rangga yang belum banyakdielaborasi. Tujuan dari penelitian ini adalah: a) Untuk menganalisis produktivitasayam buras hasil seleksi; b) Untuk menganalisis pengetahuan lokal peternakmengenai ayam buras; c) Untuk menganalisis hubungan antara produktivitasayam buras hasil seleksi dengan pengetahuan lokal peternak. Metode yangdigunakan dalam penelitian ini studi kasus dengan teknik PRA (Praticipation RuralAppraisal) partisipasi anggota kelompok melalui pola FGD (Focus GroupDiscussion). Data yang diambil untuk pengembangan sistem pengetahuan lokalberdasarkan variabel-variabel: (1) Sistem pengetahuan lokal, dengan parameter:a) Tulang; b) Bulu; c) Jengger; d) Kaki; e) Mata; f) Kloaka; g) Tulang dubur; h)Jari kaki; i) Kepala; Punggung. (2) Produktivitas, dengan parameter data produksitelur per bulan. Metode analisis yang digunakan adalah Uji Rank Spearman(Siegel, 1997) dan interprestasi dengan Guilford (Rakhmat, 1986). Kesimpulandari hasil penelitian ini adalah: a) Produktivitas ayam buras hasil seleksiditunjukkan oleh nilai rata-rata produksi telur 20,45/butir/bulan; b) Pengetahuanlokal peternak mengenai ayam buras sebagian besar searah dengan ilmupengetahuan modern, yang pada mulanya dikonsepsikan dengan Catur Ranggauntuk ayam adu kemudian juga digunakan untuk ayam produksi; c) Hubunganantara produktivitas ayam buras dengan pengetahuan lokal: untuk produksi ratarataproduksi telur/bulan menunjukkan hubungan yang sangat tinggi. Saran yangdiajukan bahwa parameter dari pengetahuan lokal dapat dijadikan salah satumetode untuk mengetahui produktivitas ayam buras di tingkat peternak; perludilakukan penelitian lanjutan yang lebih mendalam mengenai pengetahuan lokaluntuk variabel lain

Shape Shifting Leads to Small-Molecule Allosteric Drug Discovery

SummaryEnzymes that regulate their activity by modulating an equilibrium of alternate, nonadditive, functionally distinct oligomeric assemblies (morpheeins) constitute a recently described mode of allostery. The oligomeric equilibrium for porphobilinogen synthase (PBGS) consists of high-activity octamers, low-activity hexamers, and two dimer conformations. A phylogenetically diverse allosteric site specific to hexamers is proposed as an inhibitor binding site. Inhibitor binding is predicted to draw the oligomeric equilibrium toward the low-activity hexamer. In silico docking enriched a selection from a small-molecule library for compounds predicted to bind to this allosteric site. In vitro testing of selected compounds identified one compound whose inhibition mechanism is species-specific conversion of PBGS octamers to hexamers. We propose that this strategy for inhibitor discovery can be applied to other proteins that use the morpheein model for allosteric regulation

Site-specific C-terminal and internal loop labeling of proteins using sortase-mediated reactions

Methods for site-specific modification of proteins should be quantitative and versatile with respect to the nature and size of the biological or chemical targets involved. They should require minimal modification of the target, and the underlying reactions should be completed in a reasonable amount of time under physiological conditions. Sortase-mediated transpeptidation reactions meet these criteria and are compatible with other labeling methods. Here we describe the expression and purification conditions for two sortase A enzymes that have different recognition sequences. We also provide a protocol that allows the functionalization of any given protein at its C terminus, or, for select proteins, at an internal site. The target protein is engineered with a sortase-recognition motif (LPXTG) at the place where modification is desired. Upon recognition, sortase cleaves the protein between the threonine and glycine residues, facilitating the attachment of an exogenously added oligoglycine peptide modified with the functional group of choice (e.g., fluorophore, biotin, protein or lipid). Expression and purification of sortase takes ∼3 d, and sortase-mediated reactions take only a few minutes, but reaction times can be extended to increase yields.National Institutes of Health (U.S.) (Grant RO1 AI08787

Epitaxial Growth of Pentacene on Alkali Halide Surfaces Studied by Kelvin Probe Force Microscopy

In the field of molecular electronics thin films of molecules adsorbed on insulating surfaces are used as the functional building blocks of electronic devices. A control of the structural and electronic properties of the thin films is required for a reliable operating mode of such devices. Here, noncontact atomic force and Kelvin probe force microscopies have been used to investigate the growth and electronic properties of pentacene on KBr(001) and KCl(001) surfaces. Mainly molecular islands of upright standing pentacene are formed, whereas a new phase of tilted molecules appear near step edges on some KBr samples. Local contact potential differences (LCPD) have been studied with both Kelvin experiments and density-functional theory calculations. Large LCPD are found between the substrate and the differently oriented molecules, which may be explained by a partial charge transfer from the pentacene to the surface. The monitoring of the changes of the pentacene islands during dewetting shows that multilayers build up at the expense of monolayers. Moreover, in the Kelvin images, previously unknown line defects appear, which unveil the epitaxial growth of pentacene crystals.Comment: This document is the unedited author's version of a Submitted Work that was subsequently accepted for publication in ACSNano, copyright American Chemical Society after peer review. To access the final edited and published work see doi belo

Forward Physics at the LHC (Elba 2010)

The papers review the main theoretical and experimental aspects of the Forward Physics at the Large Hadron Collider

Site-specific protein modification using immobilized sortase in batch and continuous-flow systems

Transpeptidation catalyzed by ​sortase A allows the preparation of proteins that are site-specifically and homogeneously modified with a wide variety of functional groups, such as fluorophores, PEG moieties, lipids, glycans, bio-orthogonal reactive groups and affinity handles. This protocol describes immobilization of ​sortase A on a solid support (Sepharose beads). Immobilization of ​sortase A simplifies downstream purification of a protein of interest after labeling of its N or C terminus. Smaller batch and larger-scale continuous-flow reactions require only a limited amount of enzyme. The immobilized enzyme can be reused for multiple cycles of protein modification reactions. The described protocol also works with a Ca²⁺-independent variant of ​sortase A with increased catalytic activity. This heptamutant variant of ​sortase A (7M) was generated by combining previously published mutations, and this immobilized enzyme can be used for the modification of calcium-senstive substrates or in instances in which low temperatures are needed. Preparation of immobilized ​sortase A takes 1–2 d. Batch reactions take 3–12 h and flow reactions proceed at 0.5 ml h⁻¹, depending on the geometry of the reactor used.United States. National Institutes of Health (RO1 AI087879