Kemampuan Siswa Dalam Menyelesaikan Soal-soal Uraian Terstruktur Pokok Bahasan Teori Kinetik Gas

"> Penelitian ini bertujuan untuk mengetahui (1) kemampuan kognitif yang dilihat dari hasil belajar peserta didik yang kelas XI MAN Model Palangka Raya dalam mengerjakan soal-soal uraian terstruktur pada pokok bahasan Teori Kinetik Gas; dan (2) kesulitan peserta didik dalam mengerjakan soal-soal uraian terstruktur. Penelitian ini menggunakan metode penelitian kuantitatif dalam mengumpulkan datanya. Penelitian ini menggunakan instrumen dalam bentuk soal uraian terstruktur. Hasil uji coba soal uraian terstruktur pada kelas XI IA-1 MAN Model Palangka Raya mendapatkan tingkat validitas rata-rata 0,536 dan tingkat reliabilitas soal 0,539 dengan kategori cukup. Hasil penelitian menunjukkan bahwa: (1) peserta didik yang mampu dan tidak mengalami masalah dalam mengerjakan soal-soal uraian terstruktur berjumlah 18 peserta didik dan 12 peserta didik tidak mampu dan mengalami masalah dalam mengerjakan soal-soal uraian terstruktur. Peserta didik yang mampu mengerjakan soal-soal uraian terstruktur memiliki ketuntasan belajar ≥ batas KKM, yaitu 60% (2) kesulitan peserta didik dalam mengerjakan soal-soal uraian terstruktur terdapat pada penyebutan dan penulisan satuan besaran pada jawaban dengan persentase kesulitan 36,7%, penguasaan operasi hitungan denganpersentase kesulitan 31,4% dan penulisan besaran yang ditanya dalam soal dengan persentase kesulitan 28,6%

Plant expression, lyophilisation and storage of HBV medium and large surface antigens for a prototype oral vaccine formulation

Current immunisation programmes against hepatitis B virus (HBV) increasingly often involve novel tri-component vaccines containing—together with the small (S-HBsAg)—also medium and large surface antigens of HBV (M- and L-HBsAg). Plants producing all HBsAg proteins can be a source of components for a potential oral ‘triple’ anti-HBV vaccine. The objective of the presented research was to study the potential of M/L-HBsAg expression in leaf tissue and conditions of its processing for a prototype oral vaccine. Tobacco and lettuce carrying M- or L-HBsAg genes and resistant to the herbicide glufosinate were engineered and integration of the transgenes was verified by PCR and Southern hybridizations. M- and L-HBsAg expression was confirmed by Western blot and assayed by ELISA at the level of micrograms per g of fresh weight. The antigens displayed a common S domain and characteristic domains preS2 and preS1 and were assembled into virus-like particles (VLPs). Leaf tissues containing M- and L-HBsAg were lyophilised to produce a starting material of an orally administered vaccine formula. The antigens were distinctly sensitive to freeze-drying conditions and storage temperature, in the aspect of stability of S and preS domains and formation of multimeric particles. Efficiency of lyophilisation and storage depended also on the initial antigen content in plant tissue, yet M-HBsAg appeared to be approximately 1.5–2 times more stable than L-HBsAg. The results of the study provide indications concerning the preparation of two other constituents, next to S-HBsAg, for a plant-derived prototype oral tri-component vaccine against hepatitis B

Fragments of LINE-1 retrotransposons flanked by inverted telomeric repeats are present in the bovine genome. Homology with human LINE-1 elements

In the bovine genome we found two intrachromosomal DNA fragments flanked by inverted telomeric repeats (GenBank Accession Nos. AF136741 and AF136742). The internal parts of the fragments are homologous exclusively to the human sequences and to the consensus sequence of the L1MC4 subfamily of LINE-1 retrotransposons which are widespread among mammalian genomes. We found that distribution of homologous human sequences within our fragments is not random, reflecting a complicated pattern of insertion mechanisms of and maintenance of retrotransposons in mammalian genomes. One of the possible explanations of the origin of LINE-1 truncated elements flanked by inverted telomeric repeats in the bovine genome is that extrachromosomal DNA fragments may be modified by telomerase and subsequently, transferred into chromosomal DNA

The factor VIII protein and its function

Factor VIII (FVIII), an essential blood coagulation protein, is a key component of the fluid phase blood coagulation system. Human factor VIII is a single chain of about 300 kDa consisting of domains described as A1-A2-B-A3-C1-C2. The protein undergoes processing prior to secretion into blood resulting in a heavy chain of 200 kDa (A1-A2-B) and a light chain of 80 kDa (A3-C1-C2) linked by metal ions. The role of factor VIII is to increase the catalytic efficiency of factor IXa in the activation of factor X. Variants of these factors lead frequently also to severe bleeding disorders

Ligation mediated PCR performed at low denaturation temperatures—PCR melting profiles

We show that using low denaturation temperatures (80–88°C) during ligation mediated PCR (LM PCR) of bacterial DNA leads to the amplification of limited sets of the less stable DNA fragments. A set of electrophoretic patterns of such fragments obtained at different denaturation temperatures forms the PCR melting profile (PCR MP). A single pattern obtained for a given temperature and a set of patterns arising after application of several denaturation temperatures (PCR MP) are very specific for the given bacterial genome and may be used for strain characterisation and differentiation. The method may also be used for amplification and isolation of the less stable DNA fragments in a genome

Integrons

Accumulation of antibiotic resistance among pathogenic bacteria has called attention to horizontal gene transfer that involves plasmids and transpozons. Integrons, usually placed on mobile genome elements, are very deeply engaged in the process of origin of multiple-drug-resistant strains. Integrons are genetic elements that contain determinants of the components of the site-specific recombination system that recognizes and captures mobile gene cassettes. More than 70 different antibiotic resistance genes covering most classes of antimicrobials presently in use have been detected in gene cassettes. Integrons are frequently found in clinical and environmental strains of gram-negative rods. The discovery of super-integrons, i.e. genetic structures gathering gene cassettes in a huge number, led to the conception of genome cassettes capture as an element of a broader phenomenon of bacterial genome modification in response to changing environmental conditions

Expression of bovine leukemia virus protein p24 in Escherichia coli and its use in the immunoblotting assay.

The gag gene encoded protein, p24 of bovine leukemia virus (BLV), was cloned and expressed as thioredoxin-6xHis-p24 protein in Escherichia coli. The bacterial cells carrying plasmid pT7THis-p24 expressed the protein of 38 kDa that was detected by immunoblotting analysis using anti-p24 monoclonal antibodies and sera from BLV infected cattle and sheep. The purified p24 fusion protein was shown to be sensitive and specific for detection of BLV antibodies in the infected cattle