Kompetensi, Sertifikasi Guru, dan Kualitas Belajar Siswa Sekolah Dasar

Studi ini bertujuan untuk mengetahui efek sertifikasi pendidik terhadap kompetensi guru dan kualitas belajar siswa. Studi cross-sectional survey, ini memilih sekolah dasar sampel secara random dari daftar sekolah dasar di Jawa Barat. Semua siswa dan guru kelas VI, kepala sekolah telah dijadikan responden, dan siswa adalah unit analisis dalam penelitian ini. Data dianalisis dengan menggunakan model fungsi produksi pendidikan dengan UASBN sebagai criteria, dan prediktor yang terpilih adalah variable sertifikasi, kompetensi guru, karakteristik siswa, kepala sekolah, dan sekolah itu sendiri. Hasil studi menunjukkan bahwa sertifikasi pendidik baru berfungsi untuk memacu kompetensi guru, bahkan belum mampu memetakan kompetensi guru, sehingga sertifikat yang dimiliki belum sepenuhnya merupakan indikator kompetensi, tetapi justru lebih berfungsi sebagai label dari senioritas guru. Dalam kondisi demikian, guru menjadi sulit mewujudkan prestasi belajar siswa, prestasi belajar siswa pada akhirnya ditentukan oleh SES (social economic status) keluarga dan kualitas sekolah. Oleh karena itu, Pemerintah diharapkan melakukan perbaikan sistem sertifikasi sehingga efeknya lebih signifikan terhadap kompetensi guru maupun prestasi belajar siswa

Aktivitas Reduksi Merkuri Pada Bakteri Yang Diisolasi Dari Air Dan Sedimen Di Sungai Musi

This study aims to isolate mercury resistant bacteria from water and sediment in Pulau Salah Nama which located on the River Musi Palembang, characterized mercury resistant bacteria growing at the highest concentration of HgCl2 and test the power of these bacteria in reducing mercury. The research was conducted from June 2015 until September 2015 using experimental methods laboris and descriptive data analysis. Reasecrh consissted of several stages, including sampling, bacterial isolation, characterization to determine the type of bacteria and mercury reducing power of bacteria. Isolation of bacteria produced 10 isolates. A1 was bacteria isolated from water and A2 was bacteria isolated from sediment. From 10 isolates selected 2 isolates of the higest concentration of HgCl2. Selected isolate A1 have the lowest mercury reduction power of 39.26% and selected isolate A2 have the highest mercury reduction power of 65.93%. In control medium without inoculant a decline in mercury concentration of 39.44%. Based on the characterization of the bacteria biochemical activity known A1 and A2 were Bacillus subtili

Bekatul Padi sebagai Sumber Produksi Minyak dan Isolat Protein

Penelitian ini bertujuan untuk memanfaatkan bekatul padi sebagai bahan bakuuntuk memperoleh minyak bekatul murni dan isolat protein. Ekstraksi minyakdilakukan dengan menggunakan pelarut n-heksan (food grade) dilanjutkandengan proses pemurnian yang meliputi penghilangan gum, penghilanganmalam, netralisasi asam lemak dengan larutan natrium hidroksida dan prosespemucatan dengan zeolit sebagai adsorben. Isolat protein di peroleh melaluiproses ekstraksi protein dari bekatul bebas lemak dengan larutan natriumhidroksida pada pH 9,5 yang dilanjutkan dengan presipitasi protein pada pH 4,5.Dengan cara di atas dalam penelitian ini diperoleh minyak bekatul kasar 14,01%b/b dan minyak bekatul murni sebanyak 22,13% dari minyak bekatul kasar.Komposisi asam lemak dari minyak bekatul murni adalah asam palmitat (C16:0)17,03%, asam oleat (C18:1 ω-9) 34,29%, asam linoleat (CI8:2 ω-6) 46,02% danasam α-linolenat (C18:3 ω-3) 2,66%. Kandungan protein total dari bekatul bebaslemak adalah 11,4%. Isolat protein yang dihasilkan mengandung 50,2% proteindengan perolehan kembali 70,1% dari berat protein dalam bekatul. Kualitasminyak bekatul murni telah memenuhi persyaratan mutu untuk minyak bekatul.Akan tetapi karena perolehan minyak bekatul murni yang rendah dan bilanganasam dari minyak bekatul kasar yang tinggi, maka mungkin minyak bekatul kasarini lebih cocok sebagai sumber produksi asam lemak jenuh atau derivat esternya

Solid-phase Synthesis of Tetrapeptide on 2-Chlorotrityl Chloride Resin by Using Benzotriazol-1-yl-oxytripyrrolidinophosphonium Hexafluorophosphate as Coupling Reagent

Tetrapeptide, OH-Pro-Ala-Gly-Tyr-NH2, was successfully synthesised on 2-chlorotrityl chloride resin by taking advantage of PyBOP (benzotriazol-1-yl-oxytripyrrolidinophosphonium hexafluorophosphate) as coupling reagent. The selection of the peptide as the target of synthesis was due to its interesting bioactivity as antioxidant. The synthesis was undertaken with Fmoc strategy, where Fmoc-proline was added onto the resin at the first place. It is known from the literature that proline can resist from rasemisation when it was attached on the resin at the first time. Fmoc deprotection step was carried out by employing 20% piperidine in DMF and the reaction mixture was shaken for 30 minutes. Once the proline attached, the next step was to attach amino acids, alanine (Ala), glycine (Gly) and tyrosine(Tyr), subsequently onto the resin until tetrapeptidyl resin was constructed on the resin. Hydroxyl group of Tyr was protected with t-butyl, which is TFA-labiled. Coupling reaction was undertaken by mixing the amino acid and PyBOP in a mixture of dichloromethane and DMF (1:1) and in the presence of basic DIPEA. Resin cleavage step was carried out by using 95% TFA in water, where t-butyl protecting group on the side chain of Tyr was cleaved at the same time. The analytical RP-HPLC of the final product showed a single peak at 21.9 minutes (20-90% of acetonitrile in water with 0.1% of TFA during 30 minutes), indicating that each coupling has given a good coupling performance and resulting in a pure product. The desired product showed the correct molecular weight with m/z 407.2 [M+H]+ and 429.2 [M+Na]. DOI: http://dx.doi.org/10.15408/jkv.v0i0.405

Karakterisasi Protease dari Bakteri Aeromonas hydrophila

In the last decade, a concern on protease as medicinal target for overcoming bacterial and viral diseases has been rapidly increased because of the obvios involvement of this enzyme in the molecular of the diseases mechanism. The porpuse of this research was to characterize proteases from fish pathogenic bacteria Aeromonas hydrophila. The bacteria were grown in media containing triptone 1%, NaCl 1% and yeast extract 0,5%. The optimum production time of A. hydrophila was 48 h, the optimum pH was 7,5, the optimum temperature was 50oC. Study on the effect of metals ion and spesific inhibitors indicated that protease from A. hydrophila was serin metaloprotease.Keywords: protease, characterization, pathogenic bacteri

Karakteristik Protease dari Bakteri Patogen Staphylococcus epidermidis

Beberapa bakteri patogen memproduksi enzim hidrolitik seperti protease dan hialuronidase yang berfungsi untuk mendegradasi komponen matrik ekstraseluler sehingga dapat merusak struktur jaringan inang. Tujuan penelitian ini adalah untuk melakukan karakterisasi protease dari bakteri Staphylococcus epidermidis yang diisolasi dari koleksi Rumah Sakit Pertamina Jakarta. Bakteri ditumbuhkan pada media Luria broth (LB) yang mengandung tryptone 1 %, NaCl 1 % dan yeast extract 0,5 %. Hasil karakterisasi menunjukkan bahwa protease S. epidermidis ini memiliki pH dan suhu optimum 8 dan 50 oC. Ion logam Mn2+ (5 mM) dan Ba2+ (5 mM) merupakan aktivator kuat protease S. epidermidis yang dapat meningkatkan aktivitas protease masing-masing 3 dan 2 kali lipat dari protease kontrol, sedangkan Na+ (1 mM), K+ (1 mM), Fe3+ (1 dan 5 mM), Zn2+ (5 mM), dan Ca2+ (1 mM) merupakan inhibitor ion logam yang kuat. Protease S. epidermidis digolongkan ke dalam serin metaloprotease karena dapat dihambat secara sempurna oleh PMSF dan EDTA. Protease tersebut mempunyai berat molekul sekitar 35 kD.Kata Kunci: bakteri patogen, karakterisasi, protease, Staphylococcus epidermidis

A two-domain elevator mechanism for sodium/proton antiport

Sodium/proton (Na+/H+) antiporters, located at the plasma membrane in every cell, are vital for cell homeostasis1. In humans, their dysfunction has been linked to diseases, such as hypertension, heart failure and epilepsy, and they are well-established drug targets2. The best understood model system for Na+/H+ antiport is NhaA from Escherichia coli1, 3, for which both electron microscopy and crystal structures are available4, 5, 6. NhaA is made up of two distinct domains: a core domain and a dimerization domain. In the NhaA crystal structure a cavity is located between the two domains, providing access to the ion-binding site from the inward-facing surface of the protein1, 4. Like many Na+/H+ antiporters, the activity of NhaA is regulated by pH, only becoming active above pH 6.5, at which point a conformational change is thought to occur7. The only reported NhaA crystal structure so far is of the low pH inactivated form4. Here we describe the active-state structure of a Na+/H+ antiporter, NapA from Thermus thermophilus, at 3 Å resolution, solved from crystals grown at pH 7.8. In the NapA structure, the core and dimerization domains are in different positions to those seen in NhaA, and a negatively charged cavity has now opened to the outside. The extracellular cavity allows access to a strictly conserved aspartate residue thought to coordinate ion binding1, 8, 9 directly, a role supported here by molecular dynamics simulations. To alternate access to this ion-binding site, however, requires a surprisingly large rotation of the core domain, some 20° against the dimerization interface. We conclude that despite their fast transport rates of up to 1,500 ions per second3, Na+/H+ antiporters operate by a two-domain rocking bundle model, revealing themes relevant to secondary-active transporters in general

The impact of community-based arts and health interventions on cognition in people with dementia: a systematic literature review

Objectives: Dementia is a progressive condition, affecting increasing numbers of people, characterised by cognitive decline. The current systematic review aimed to evaluate research pertaining to the impact of arts and health interventions on cognition in people with dementia. Method: A literature search was conducted utilising PsychInfo, Cochrane Reviews, Web of Science, Medline and British Humanities Index databases. Seventeen studies were included in the review, including those related to literary, performing and visual arts. Results: The review highlighted this as an emerging area of research with the literature consisting largely of small-scale studies with methodological limitations including lack of control groups and often poorly defined samples. All the studies suggested, however, that arts-based activities had a positive impact on cognitive processes, in particular on attention, stimulation of memories, enhanced communication and engagement with creative activities. Conclusion: The existent literature suggests that arts activities are helpful interventions within dementia care. A consensus has yet to emerge, however, about the direction for future research including the challenge of measurement and the importance of methodological flexibility. It is suggested that further research address some of these limitations by examining whether the impact of interventions vary depending n cognitive ability and to continue to assess how arts interventions can be of use across the stages of dementia