PENGEMBANGAN MEDIA PAPAN MISTERI UNTUK KEMAMPUAN PERKALIAN DAN PEMBAGIAN KELAS III SD

Pembelajaran matematika perkalian dan pembagian merupakan salah satu kompetensi penting yang harus dikuasai peserta didik. Hanya saja kenyataan di lapangan menunjukkan bahwa kemampuan perkalian dan pembagian peserta didik masih rendah dan kurangnya media yang mendukung dalam pembelajaran. Tujuan penelitian ini yakni untuk menghasilkan produk berupa media papan misteri untuk kemampuan penjumlahan perkalian dan pembagian siswa kelas III SD. Penelitian ini diklasifikasika ke dalam penelitian pengembangan yang dilakukan dengan model pengembangan ADDIE. Subjek yang terlibat dalam penelitian ini yakni ahli media, ahli materi, dan 9 peserta didik kelas III SD. Pengumpulan data pada penelitian dilakukan dengan metode observasi, wawancara, dan angket kuisioner. Instrumen penelitian berupa lembar observasi, wawancara, validasi penilaian ahli media, dan materi, lembar respon siswa, lembar tes dengan teknik pretest dan posttest. Data yang didapat pada penelitian kemudian dianalisis dengan menggunakan data deskriptif kualitatif berdasarkan wawancara dan observasi kemudian dikuantitatifkan berdasarkan angka-angka yang diperoleh dari skor uji NGain guna mengetahui efektivitas media papan misteri untuk kemampuan perkalian dan pembagian peserta didik. Hasil penelitian menunjukkan bahwa rerata persentase hasil analisis ahli media, materi, dan bahasa 82,2% termasuk ke dalam kategori layak. Kemudian, tanggapan peserta didik sangat baik saat menggunakan media papan mister sebagai media pembelajaran dengan presentase 94%. Hasil N-gain tes peserta didik termasuk ke dalam kategori peningkatan sedang. Dengan demikian, dapat disimpulkan bahwa keseluruhan media papan misteri layak digunakan untuk kemampuan perkalian dan pembagian peserta didik

Determinants of Inapparent and Symptomatic Dengue Infection in a Prospective Study of Primary School Children in Kamphaeng Phet, Thailand

Dengue viruses are a major cause of illness and hospitalizations in tropical and subtropical regions of the world. Severe dengue illness can cause prolonged hospitalization and in some cases death in both children and adults. The majority of dengue infections however are inapparent, producing little clinical illness. Little is known about the epidemiology or factors that determine the incidence of inapparent infection. We describe in a study of school children in Northern Thailand the changing nature of symptomatic and inapparent dengue infection. We demonstrate that the proportion of inapparent dengue infection varies widely among schools during a year and within schools during subsequent years. Important factors that determine this variation are the amount of dengue infection in a given and previous year. Our findings provide an important insight in the virus-host interaction that determines dengue severity, how severe a dengue epidemic may be in a given year, and important clues on how a dengue vaccine may be effective

Dengue virus neutralizing antibody levels associated with protection from infection in Thai cluster studies

BACKGROUND: Long-term homologous and temporary heterologous protection from dengue virus (DENV) infection may be mediated by neutralizing antibodies. However, neutralizing antibody titers (NTs) have not been clearly associated with protection from infection. METHODOLOGY/PRINCIPAL FINDINGS: Data from two geographic cluster studies conducted in Kamphaeng Phet, Thailand were used for this analysis. In the first study (2004-2007), cluster investigations of 100-meter radius were triggered by DENV-infected index cases from a concurrent prospective cohort. Subjects between 6 months and 15 years old were evaluated for DENV infection at days 0 and 15 by DENV PCR and IgM ELISA. In the second study (2009-2012), clusters of 200-meter radius were triggered by DENV-infected index cases admitted to the provincial hospital. Subjects of any age 6 months and older were evaluated for DENV infection at days 0 and 14. In both studies, subjects who were DENV PCR positive at day 14/15 were considered to have been susceptible on day 0. Comparison subjects from houses in which someone had documented DENV infection, but the subject remained DENV negative at days 0 and 14/15, were considered non-susceptible. Day 0 samples were presumed to be from just before virus exposure, and underwent plaque reduction neutralization testing (PRNT). Seventeen susceptible (six DENV-1, five DENV-2, and six DENV-4), and 32 non-susceptible (13 exposed to DENV-1, 10 DENV-2, and 9 DENV-4) subjects were evaluated. Comparing subjects exposed to the same serotype, receiver operating characteristic (ROC) curves identified homotypic PRNT titers of 11, 323 and 16 for DENV-1, -2 and -4, respectively, to differentiate susceptible from non-susceptible subjects. CONCLUSIONS/SIGNIFICANCE: PRNT titers were associated with protection from infection by DENV-1, -2 and -4. Protective NTs appeared to be serotype-dependent and may be higher for DENV-2 than other serotypes. These findings are relevant for both dengue epidemiology studies and vaccine development efforts

Preexisting Japanese Encephalitis Virus Neutralizing Antibodies and Increased Symptomatic Dengue Illness in a School-Based Cohort in Thailand

Dengue viruses (DENVs) and Japanese encephalitis virus (JEV) have significant cross-reactivity in serological assays, but the possible clinical implications of this remain poorly understood. Interactions between these flaviviruses are potentially important for public health because wild-type JEV continues to co-circulate with DENV in Southeast Asia, the area with the highest burden of DENV illness, and JEV vaccination coverage in this region is high. In this study, we examined how preexisting JEV neutralizing antibodies (NAbs) influenced the clinical severity of subsequent DENV infection using data from a prospective school-based cohort study in Thailand that captured a wide range of clinical severities, including asymptomatic, non-hospitalized, and hospitalized DENV infections. We found that the prior existence of JEV NAbs was associated with an increased occurrence of symptomatic versus asymptomatic DENV infection. This association was most notable in DENV-naives, in whom the presence of JEV NAbs was also associated with an illness of longer duration. These findings suggest that the issue of heterologous flavivirus immunity and DENV infection merits renewed attention and interest and that DENV vaccine developers might incorporate detailed assessments of preexisting immunity to non-DENV flaviviruses and histories of vaccination against non-DENV flaviviruses in evaluating DENV vaccine safety and efficacy

High rate of subclinical chikungunya virus infection and association of neutralizing antibody with protection in a prospective cohort in the Philippines.

BACKGROUND: Chikungunya virus (CHIKV) is a globally re-emerging arbovirus for which previous studies have indicated the majority of infections result in symptomatic febrile illness. We sought to characterize the proportion of subclinical and symptomatic CHIKV infections in a prospective cohort study in a country with known CHIKV circulation. METHODS/FINDINGS: A prospective longitudinal cohort of subjects ≥6 months old underwent community-based active surveillance for acute febrile illness in Cebu City, Philippines from 2012-13. Subjects with fever history were clinically evaluated at acute, 2, 5, and 8 day visits, and at a 3-week convalescent visit. Blood was collected at the acute and 3-week convalescent visits. Symptomatic CHIKV infections were identified by positive CHIKV PCR in acute blood samples and/or CHIKV IgM/IgG ELISA seroconversion in paired acute/convalescent samples. Enrollment and 12-month blood samples underwent plaque reduction neutralization test (PRNT) using CHIKV attenuated strain 181/clone25. Subclinical CHIKV infections were identified by ≥8-fold rise from a baseline enrollment PRNT titer 50 years old. Baseline CHIKV PRNT titer ≥10 was associated with 100% (95%CI: 46.1, 100.0) protection from symptomatic CHIKV infection. Phylogenetic analysis demonstrated Asian genotype closely related to strains from Asia and the Caribbean. CONCLUSIONS: Subclinical infections accounted for a majority of total CHIKV infections. A positive baseline CHIKV PRNT titer was associated with protection from symptomatic CHIKV infection. These findings have implications for assessing disease burden, understanding virus transmission, and supporting vaccine development

G-CSF/anti-G-CSF antibody complexes drive the potent recovery and expansion of CD11b+Gr-1+ myeloid cells without compromising CD8+ T cell immune responses

BACKGROUND: Administration of recombinant G-CSF following cytoreductive therapy enhances the recovery of myeloid cells, minimizing the risk of opportunistic infection. Free G-CSF, however, is expensive, exhibits a short half-life, and has poor biological activity in vivo. METHODS: We evaluated whether the biological activity of G-CSF could be improved by pre-association with anti-G-CSF mAb prior to injection into mice. RESULTS: We find that the efficacy of G-CSF therapy can be enhanced more than 100-fold by pre-association of G-CSF with an anti-G-CSF monoclonal antibody (mAb). Compared with G-CSF alone, administration of G-CSF/anti-G-CSF mAb complexes induced the potent expansion of CD11b(+)Gr-1(+) myeloid cells in mice with or without concomitant cytoreductive treatment including radiation or chemotherapy. Despite driving the dramatic expansion of myeloid cells, in vivo antigen-specific CD8(+) T cell immune responses were not compromised. Furthermore, injection of G-CSF/anti-G-CSF mAb complexes heightened protective immunity to bacterial infection. As a measure of clinical value, we also found that antibody complexes improved G-CSF biological activity much more significantly than pegylation. CONCLUSIONS: Our findings provide the first evidence that antibody cytokine complexes can effectively expand myeloid cells, and furthermore, that G-CSF/anti-G-CSF mAb complexes may provide an improved method for the administration of recombinant G-CSF

Isolasi Bakteriofag Vibrio parahaemolyticus dari Kerang Darah (Anadara granosa) dan Kerang Hijau (Perna viridis)

Udang vaname (Litopenaeus vannamei) saat ini menjadi salah satu komoditas ekspor unggulan Indonesia yang terlihat dari prospek pasarnya yang masih potensial. Namun ekspor udang ini memiliki permasalahan pada mutu dan keamanan pangan. Salah satu prasyarat mutu udang adalah bebas dari cemaran bakteri Vibrio sp. Mengkonsumsi makanan laut yang telah terkontaminasi bakteri atau toksin yang dihasilkannya dapat menyebabkan keracunan makanan (foodborne disease). Salah satu jenis bakteri Vibrio penyebab foodborne disease adalah Vibrio parahaemolyticus. Penggunaan antibiotik merupakan upaya untuk menanggulangi foodborne disease. Namun, penggunaan yang terus-menerus dapat memberikan sifat resistensi bakteri patogen terhadap antibiotik. Salah satu cara untuk menanggulangi Vibrio parahaemolyticus yang relatif aman untuk menangani masalah foodborne disease yaitu bakteriofag. Bakteriofag adalah virus yang menyerang bakteri dan memiliki materi genetik berupa DNA maupun RNA. Penelitian ini bertujuan untuk memperoleh bakteri spesifik Vibrio parahaemolyticus yang berhasil diisolasi dari udang vaname dan juga memperoleh bakteriofag yang berhasil diisolasi pada kerang darah dan kerang hijau. Metode penelitian yang digunakan deksriptif eksploratif. Tahapan dalam melakukan penelitian meliputi dua tahap yakni tahap pertama melakukan isolasi bakteri Vibrio parahaemolyticus dengan metode pour plate, purifikasi dan penyimpanan kultur dilakukan dengan metode gores (streak), dan dilakukan identifikasi spesies (morfologi, biokimia, dan molekuler). Tahap kedua melakukan isolasi bakteriofag dengan metode double layer agar, pembuatan stok bakteriofag dengan metode flooding, penentuan densitas, uji konfirmasi dan uji kisaran inang menggunakan metode spot test. Hasil penelitian menunjukan bahwa udang vaname terdapat dua isolat (HB3 dan HC1) terduga bakteri Vibrio parahaemolyticus yang diidentifikasi secara morfologi dan pewarnaan gram lalu diidentifikasi secara biokimia terdapat isolat (HC1). Isolat tersebut diidentifikasi secara molekuler dengan Polymerase Chain Reaction (PCR) dan primer 16S rDNA sehingga diketahui terdapat Vibrio parahaemolyticus pada isolat (HC1). Kerang darah (Anadara granosa) dan kerang hijau (Perna viridis) merupakan sampel yang menghasilkan bakteriofag. Keberhasilan isolasi bakteriofag tersebut ditandai dengan terbentuknya plaque pada cawan agar double layer. Densitas bakteriofag pada kerang darah (KD) 3,7x 104 PFU/mL dan kerang hijau (KH) 1,38x107 PFU/mL. Hasil host range menunjukkan bahwa kedua lisat bakteriofag dapat melisiskan bakteri Vibrio parahaemolyticus, Vibrio alginolyticus, Vibrio cholerae, Vibrio harveyi dan Aeromonas hyrophila. Saran untuk penelitian selanjutnya diperlukan pengujian multiplicity of infection, efficiency of plating dan transmission electron microscope untuk mengetahui jenis bakteriofag yang telah diisolasi