Browsing by Author "Mueller, Andreas"

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    Framing the concept of satellite remote sensing essential biodiversity variables : challenges and future directions
    (John Wiley & Sons Ltd., 2016-03) Pettorelli, Nathalie; Wegmann, Martin; Skidmore, Andrew; Mucher, Sander; Dawson, Terence P.; Fernandez, Miguel; Lucas, Richard; Schaepman, Michael E.; Wang, Tiejun; O’Connor, Brian; Jongman, Robert H. G.; Kempeneers, Pieter; Sonnenschein, Ruth; Leidner, Allison K.; Bohm, Monika; He, Kate S.; Nagendra, Harini; Dubois, Gregoire; Fatoyinbo, Temilola; Hansen, Matthew C.; Paganini, Marc; De Klerk, Helen Margaret; Asner, Gregory P.; Kerr, Jeremy T.; Estes, Anna B.; Schmeller, Dirk S.; Heiden, Uta; Rocchini, Duccio; Pereira, Henrique M.; Turak, Eren; Fernandez, Nestor; Lausch, Angela; Cho, Moses A.; Alcaraz-Segura, Domingo; McGeoch, Melodie A.; Turner, Woody; Mueller, Andreas; St-Louis, Veronique; Penner, Johannes; Vihervaara, Petteri; Belward, Alan; Reyers, Belinda; Geller, Gary N.
    Although satellite-based variables have for long been expected to be key components to a unified and global biodiversity monitoring strategy, a definitive and agreed list of these variables still remains elusive. The growth of interest in biodiversity variables observable from space has been partly underpinned by the development of the essential biodiversity variable (EBV) framework by the Group on Earth Observations – Biodiversity Observation Network, which itself was guided by the process of identifying essential climate variables. This contribution aims to advance the development of a global biodiversity monitoring strategy by updating the previously published definition of EBV, providing a definition of satellite remote sensing (SRS) EBVs and introducing a set of principles that are believed to be necessary if ecologists and space agencies are to agree on a list of EBVs that can be routinely monitored from space. Progress toward the identification of SRS-EBVs will require a clear understanding of what makes a biodiversity variable essential, as well as agreement on who the users of the SRS-EBVs are. Technological and algorithmic developments are rapidly expanding the set of opportunities for SRS in monitoring biodiversity, and so the list of SRS-EBVs is likely to evolve over time. This means that a clear and common platform for data providers, ecologists, environmental managers, policy makers and remote sensing experts to interact and share ideas needs to be identified to support long-term coordinated actions.
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    Prevalence of chronic HBV infection in pregnant woman attending antenatal care in a tertiary hospital in Mwanza, Tanzania : a cross-sectional study
    (BMC (part of Springer Nature), 2020-06-05) Geffert, Karin; Maponga, Tongai G.; Henerico, Shimba; Preiser, Wolfgang; Mongella, Stella; Stich, August; Kalluvya, Samuel; Mueller, Andreas; Kasang, Christa
    Background: Tanzania has a high prevalence (7.17%) of chronic hepatitis B infection. Mother to Child transmission is very common, resulting in high rate of chronic infections. Currently, there is no screening program for HBV in pregnant women. This study investigated the prevalence and risk factors for chronic HBV infection in pregnant women in a tertiary hospital in Mwanza, Tanzania. Methods: Seven hundred and forty-three women attending antenatal care and/or delivering at the Bugando Medical Centre were enrolled. All answered a questionnaire on sociodemographic and other risk factors and were tested for HBsAg using a rapid test. In HBsAg positive mothers, maternal blood and umbilical cord blood samples collected after delivery were analyzed for serological (HBsAg, HBeAg and anti-HBe) and virologic (HBV-DNA viral load and genotype) markers. All their babies were vaccinated within 24 h of delivery. The children were followed up at 3 years of age. Data was analyzed using the Mann-Whitney U-test, independent sample T-test and logistic regression. Results: Of the 743 participants, 22 (3%) were positive for HBsAg, and 2 (9%) had detectable HBe-antigen. Low condom use was the only statistically significant risk factor for chronic HBV infection (OR = 3.514, 95%CI = 1.4–8.0). Of 14 maternal blood samples genotyped, 10 (71%) were genotype A and 4 (29%) were genotype D. HBV-DNA was detected in 21/22 samples, with a median of 241 IU/ml (range: 27.4–25.9 × 107 IU/ml). Five (33%) of 15 available cord blood samples were positive for HBsAg and 10 (67%) were negative. At follow-up, one child showed chronic HBV infection characteristics, one had anti-HBs level of 7 mIU/ml and 5/7(71%) had protective anti-HBs levels (> 10 mIU/ml). Conclusion: This cohort of pregnant women showed a lower-intermediate prevalence of HBV of 3%. In the 3 years follow-up only 1 out of 7 children showed evidence of chronic HBV infection. The child’s mother with high viral load (25.9 × 107 IU/ml), was positive for HBeAg with a high degree of sequence similarity suggesting vertical transmission. These results highlight a need for improved diagnosis and treatment of HBV infection in pregnant women in Tanzania, in order to prevent vertical transmission.