Kondisi Fertilitas Mencit Jantan yang Diberi Ekstrak Etanol Akar Alang-alang (Imperata cylindrica)

Pengendalian populasi hewan umumnya dilakukan dengan sterilisasi. Namun biaya yang diperlukan cenderung mahal sehingga diperlukan tindakan lain untuk mengendalikan populasi hewan. Pemanfaatan tumbuhan sebagai herbal yang digunakan untuk kontrasepsi alami hewan sedang dikembangkan. Pada penelitian sebelumnya diketahui bahwa pemberian ekstrak etanol akar alang-alang menyebabkan penurunan bobot kelenjar testis, vesical seminalis dan epididimis sehingga menyebabkan penurunan produksi spermatozoa dan perubahan profil metabolit pada mencit jantan. Namun, pengaruh ekstrak etanol akar alang-alang terhadap morfometri fetus dari mencit betina dikawinkan dengan mencit jantan perlakuanbelum diketahui. Penelitian ini bertujuan untuk mengetahui pengaruh pemberian ekstrak etanol akar alang-alang hasil konsepsi mencit jantan pada mencit betina yang tidak diberi perlakuan. Mencit jantan diberi ekstrak etanol akar alang-alang selama 180 hari (Imperata cylindrica) 90 dan 115 mg/kg BB per oral kemudian dikawinkan dengan mencit betina yang tidak diberi perlakuan. Hasil penelitian menunjukkan bahwa terjadi penurunan jumlah fetus, berat badan dan panjang fetus pada kelompok perlakuan 90 dan 115 mg/kgBB. Pemberian ekstrak etanol akar alang-alang pada mencit jantan berpengaruh secara signifikan terhadap jumlah mencit betina yang bunting dan morfometri fetus yang dikandung mencit betina

Zur Optimierung des multidisziplinaeren Entwurfs von Verkehrsflugzeugen in der parallelen Rechenumgebung

For cost reasons, during the concept and preliminary design phases in the development of new airliners, program systems are used for modeling the multidisciplinary design process. However, more and more sophisticated subroutines integrated into such systems in order to achieve the desired high accuracy of results, cause an increasing requirement for central processing unit time. In order to reduce design times for the assessment of new configurations, the central processing unit times of design programs must be minimized while ensuring the required high accuracy of results. In order to reduce the CPU time required for finding the optimum solution, this doctoral thesis integrates optimization processes in accordance with gradient methods into the PrADO (Preliminary Aircraft Design and Optimization) program system. To determine the required system sensitivity, in addition to the finite difference method also the decomposition method was applied, which requires breaking down the program system into non-hierarchic program structures. Using a typical multidisciplinary airliner design process as an example, the system sensitivities determined by means of both methods were investigated for their accuracy and central processing unit times. Starting from a base design, then optimization calculations were made in order to investigate how the determined system sensitivity affects the numerical optimization. (orig./AKF)SIGLEAvailable from TIB Hannover: RO 8542(94-02) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Effects of diverse mangrove management practices on forest structure, carbon dynamics and sedimentation in North Sumatra, Indonesia

For decades, mangrove forests have been under tremendous pressure due to deforestation and conversion. To sustainably manage the mangroves that remain, an ecosystem approach to management is essential. Two different management regimes – conservation and restoration – were assessed, looking at their respective effects on forest structure and carbon cycling capacity, when compared with degraded mangrove. We found that mangrove restoration enhanced tree density, while mangrove conservation was able to maintain species diversity. In terms of carbon budgets, aboveground carbon was lower in restored mangrove (79.40 ± 37.41 Mg C ha−1) when compared with conserved mangrove (92.26 ± 22.65 Mg C ha−1), but was almost double that found in degraded mangrove (39.89 ± 27.49 Mg C ha−1). Although conserved mangrove had higher aboveground carbon, lower amounts of soil carbon were found in conserved mangrove (127.49 ± 33.21 Mg C ha−1) than in restored and degraded mangrove (236.26 ± 20.33 Mg C ha−1 and 139.17 ± 25.44 Mg C ha−1, respectively). The elevation change was highest in degraded mangrove (41.7 ± 24.0 mm yr−1), followed by restored (20.7 ± 14.6 mm yr−1) and conserved mangrove (12.2 ± 3.9 mm yr−1). Carbon burial in conserved mangrove (1.20 ± 1.90 Mg C ha−2 yr−1) was double that of degraded mangrove (0.63 ± 0.60 Mg C ha−2 yr−1). Ultimately, we conclude that although a conserved mangrove is not always the end result of mangrove restoration and sustainable management, finding balance between structural development and ecosystem function is essential to serve different objectives, including biodiversity maintenance

Organic carbon burial and sources in soils of coastal mudflat and mangrove ecosystems

© 2019 The Authors Mangrove organic carbon is primarily stored in soils, which contain more than two-thirds of total mangrove ecosystem carbon stocks. Despite increasing recognition of the critical role of mangrove ecosystems for climate change mitigation, there is limited understanding of soil organic carbon sequestration mechanisms in undisturbed low-latitude mangroves, specifically on organic carbon burial rates and sources. This study assessed soil organic carbon burial rates, sources and stocks across an undisturbed coastal mudflat and mangrove hydrogeomorphological catena (fringe mangrove and interior mangrove) in Bintuni Bay, West Papua Province, Indonesia. 210Pb radionuclide sediment dating, and mixing model of natural stable isotope signatures (δ 13C and δ15N) and C/N ratio were used to estimate organic carbon burial rates and to quantify proportions of allochthonous (i.e., upland terrestrial forest) and autochthonous (i.e., on-site mangrove forest) organic carbon in the top 50 cm of the soil. Burial rates were in the range of 0.21–1.19 Mg C ha−1 yr−1. Compared to the fringe mangroves, organic carbon burial rates in interior mangroves were almost twice as high. Primary productivity of C3 upland forest vegetation and mangroves induced soil organic carbon burial in interior mangroves and this was consistent with the formation of the largest organic carbon stocks (179 ± 82 Mg C ha−1). By contrast, organic carbon stored in the fringe mangrove (68 ± 11 Mg C ha−1) and mudflat (62 ± 10 Mg C ha−1) soils mainly originated from upland forests (allochthonous origin). These findings clearly indicate that carbon sequestered and cycling in mangrove and terrestrial forest ecosystems are closely linked, and at least a part of carbon losses (e.g., erosion) from terrestrial forests is buried in mangrove ecosystems

Organic carbon burial and sources in soils of coastal mudflat and mangrove ecosystems

Mangrove organic carbon is primarily stored in soils, which contain more than two-thirds of total mangrove ecosystem carbon stocks. Despite increasing recognition of the critical role of mangrove ecosystems for climate change mitigation, there is limited understanding of soil organic carbon sequestration mechanisms in undisturbed low-latitude mangroves, specifically on organic carbon burial rates and sources. This study assessed soil organic carbon burial rates, sources and stocks across an undisturbed coastal mudflat and mangrove hydrogeomorphological catena (fringe mangrove and interior mangrove) in Bintuni Bay, West Papua Province, Indonesia. 210Pb radionuclide sediment dating, and mixing model of natural stable isotope signatures (δ 13C and δ15N) and C/N ratio were used to estimate organic carbon burial rates and to quantify proportions of allochthonous (i.e., upland terrestrial forest) and autochthonous (i.e., on-site mangrove forest) organic carbon in the top 50 cm of the soil. Burial rates were in the range of 0.21–1.19 Mg C ha−1 yr−1. Compared to the fringe mangroves, organic carbon burial rates in interior mangroves were almost twice as high. Primary productivity of C3 upland forest vegetation and mangroves induced soil organic carbon burial in interior mangroves and this was consistent with the formation of the largest organic carbon stocks (179 ± 82 Mg C ha−1). By contrast, organic carbon stored in the fringe mangrove (68 ± 11 Mg C ha−1) and mudflat (62 ± 10 Mg C ha−1) soils mainly originated from upland forests (allochthonous origin). These findings clearly indicate that carbon sequestered and cycling in mangrove and terrestrial forest ecosystems are closely linked, and at least a part of carbon losses (e.g., erosion) from terrestrial forests is buried in mangrove ecosystems. © 2019 The Author