STUDI TENTANG PERILAKU PELAT BETON DI ATAS TANAH GAMBUT UNTUK PENGEMBANGAN JALAN BETON DI PONTIANAK

Sebagian besar tanah permukaan di Kota Pontianak merupakan tanah gambut yang cukup tebal. Dari sudut pandang teknik sipil, tanah gambut mempunyai sifat-sifat mekanis yang tidak menguntungkan. Hal ini merupakan problema bagi para praktisi konstruksi gedung, jalan, dan jembatan di Kalimantan Barat pada umumnya. Sering dijumpai kegagalan konstruksi jalan menunjukkan bahwa para praktisi masih belum berhasil dengan memuaskan mengatasi rendahnya daya dukung tanah di daerah ini. Tulisan ini bermaksud memberikan kontribusi untuk memecahkan masalah tersebut melalui simulasi program komputer. Variabel yang ditinjau adalah B (panjang sisi pelat bujur sangkar). Dari hasil studi ini didapat hubungan antara q (tekanan tanah) dan d (deformasi tanah). Dari hubungan q dan d diperoleh hubungan P (beban) dan d. Dari hubungan P dan d diperoleh hubungan Pu(beban ultimit) dan B. Dari hubungan q dan d diperoleh hubungan k (modulus reaksi tanah dasar) dan d. Dari hubungan k dan d diperoleh nilai k1(k pada penurunan 1 inci) dan B. Dalam beberapa tabel ataupun monograf yang menyajikan nilai k dari berbagai literatur, nilai B jarang muncul untuk menentukan nilai k1. Dari hasil studi ini, grafik k1 dan B dengan jelas menggambarkan nilai k1 semakin mengecil seiring dengan membesarnya nilai B. Untuk pelat berukuran 1,2m?1,2m diperoleh nilai k1 sebesar 0,144 MN/m3

Uptake and outcomes of a prevention-of mother-to-child transmission (PMTCT) program in Zomba district, Malawi

<p>Abstract</p> <p>Background</p> <p>HIV prevalence among pregnant women in Malawi is 12.6%, and mother-to-child transmission is a major route of transmission. As PMTCT services have expanded in Malawi in recent years, we sought to determine uptake of services, HIV-relevant infant feeding practices and mother-child health outcomes.</p> <p>Methods</p> <p>A matched-cohort study of HIV-infected and HIV-uninfected mothers and their infants at 18-20 months post-partum in Zomba District, Malawi. 360 HIV-infected and 360 HIV-uninfected mothers were identified through registers. 387 mother-child pairs were included in the study.</p> <p>Results</p> <p>10% of HIV-infected mothers were on HAART before delivery, 27% by 18-20 months post-partum. sd-NVP was taken by 75% of HIV-infected mothers not on HAART, and given to 66% of infants. 18% of HIV-infected mothers followed all current recommended PMTCT options. HIV-infected mothers breastfed fewer months than HIV-uninfected mothers (12 vs.18, respectively; <it>p </it>< 0.01). 19% of exposed versus 5% of unexposed children had died by 18-20 months; <it>p </it>< 0.01. 28% of exposed children had been tested for HIV prior to the study, 76% were tested as part of the study and 11% were found HIV-positive. HIV-free survival by 18-20 months was 66% (95%CI 58-74). There were 11(6%) maternal deaths among HIV-infected mothers only.</p> <p>Conclusion</p> <p>This study shows low PMTCT program efficiency and effectiveness under routine program conditions in Malawi. HIV-free infant survival may have been influenced by key factors, including underuse of HAART, underuse of sd-NVP, and suboptimal infant feeding practices. Maternal mortality among HIV-infected women demands attention; improved maternal survival is a means to improve infant survival.</p

Poor association between 13-valent pneumococcal conjugate vaccine-induced serum and mucosal antibody responses with experimental Streptococcus pneumoniae serotype 6B colonisation

Background Pneumococcal carriage is the primary reservoir for transmission and a prerequisite for invasive pneumococcal disease. Pneumococcal Conjugate Vaccine 13 (PCV13) showed a 62% efficacy in protection against experimental Streptococcus pneumoniae serotype 6B (Spn6B) carriage in a controlled human infection model (CHIM) of healthy Malawian adults. We, therefore, measured humoral responses to experimental challenge and PCV-13 vaccination and determined the association with protection against pneumococcal carriage. Methods We vaccinated 204 young, healthy Malawian adults with PCV13 or placebo and nasally inoculated them with Spn6B at least four weeks post-vaccination to establish carriage. We collected peripheral blood and nasal lining fluid at baseline, 4 weeks post-vaccination (7 days pre-inoculation), 2, 7, 14 and > 1 year post-inoculation. We measured the concentration of anti-serotype 6B Capsular Polysaccharide (CPS) Immunoglobulin G (IgG) and IgA antibodies in serum and nasal lining fluid using the World Health Organization (WHO) standardised enzyme-linked immunosorbent assay (ELISA). Results PCV13-vaccinated adults had higher serum IgG and nasal IgG/IgA anti-Spn6B CPS-specific binding antibodies than placebo recipients 4 to 6 weeks post-vaccination, which persisted for at least a year after vaccination. Nasal challenge with Spn6B did not significantly alter serum or nasal anti-CPS IgG binding antibody titers with or without experimental pneumococcal carriage. Pre-challenge titers of PCV13-induced serum IgG and nasal IgG/IgA anti-Spn6B CPS binding antibodies did not significantly differ between those that got experimentally colonised by Spn6B compared to those that did not. Conclusion This study demonstrates that despite high PCV13 efficacy against experimental Spn6B carriage in young, healthy Malawian adults, robust vaccine-induced systemic and mucosal anti-Spn6B CPS binding antibodies did not directly relate to protection

Effect of cytomegalovirus infection on breastfeeding transmission of HIV and on the health of infants born to HIV-infected mothers

Cytomegalovirus (CMV) infection can be acquired in utero or postnatally through horizontal transmission and breastfeeding. The effect of postnatal CMV infection on postnatal HIV transmission is unknown

Plasma Micronutrient Concentrations Are Altered by Antiretroviral Therapy and Lipid-Based Nutrient Supplements in Lactating HIV-Infected Malawian Women

Background: Little is known about the influence of antiretroviral therapy with or without micronutrient supplementation on the micronutrient concentrations of HIV-infected lactating women in resource-constrained settings