New denitrifying bacteria isolated from Red Sea sediments

Sediments of various newly discovered deeps in the Red Sea were analyzed for the occurrence of denitrifying bacteria. The samples were collected in 1972 during the Valdivia cruises. Among the 27 different samples investigated, 17 revealed both coccoid and rod-shaped bacteria when enriched in complex nutrient broth (with 10% NaCl). Denitrifiers were recorded abundantly in the sediments, their population decreasing from some 10⁶/g in the surface material to only a few in the subsediment. A total of 16 pure cultures of denitrifying bacteria were isolated from the Suakin-and Thetis-deeps and studied morphologically, physiologically and biochemically. Genetics (molar percentage of guanine plus cytosine, % GC) and numerical taxonomy were included to reveal relationships and improve taxonomic classification. Fifteen isolates were described as Gram-negative, aerobic and facultative anaerobic (with NO ₃ ^- as H⁺-acceptor), polarly flagellated rods (Pseudomonas spp.); one was an inmotile, Gram-positive, facultative anaerobic coccus. None of the 15 Pseudomonas-isolates could be identified with one of the denitrifying species so far described and recognized. The strains should be regarded as hitherto undescribed denitrifying marine bacteria.Supported by the Bundesministerium für Forschung und Technologie, Bonn, Germany (FRG).     

Chemie und Biochemie des Humuskörpers unserer Böden

Progress in the chemistry and biochemistry of soil humic substances and their routes of formation has developed sufficiently to allow a coherent review of its various general aspects. Actual adsorption phenomena as well as the classical functions (such as nutrient supply, ion exchange, structure stabilization, and N-reservoir) of organic matter are outlined briefly and in a general sense. More specifically, the role and fate of nitrogen during the degradation, cryptic turnover, and the synthesis of ultimate, stable humic compounds are stressed. Based on recent results of analytic- and model-synthetic experiments, essential traits of humification (such as polymerization, condensation, and nucleophilic addition) are reviewed.     

Sustainable livelihoods and people’s vulnerability in the face of coastal hazards

The present study investigates into the link between people’s vulnerability in the face of coastal hazards and sustainable livelihoods. It focuses on the town of Borongan in the Philippines and draws on questionnaire-based surveys and focus group discussions. This research shows that local fishermen are often compelled to go out fishing despite pending typhoon or storm surge to sustain the daily needs of their family. Its also demonstrates that the capacity of these people to protect themselves from the threat is constrained by poor and fragile livelihoods. In the event of a crisis, the study argues that people resort to a range of adjustments on their daily life which is rooted in the strength and diversity of their livelihoods. To reduce people’s vulnerability and enhance capacities to face coastal hazards, the study fosters Community-Based Disaster Risk Reduction with special emphasis to sustainable livelihoods.     

Degradation of the fungicide difenoconazole in a silt loam soil as affected by pretreatment and organic amendment

Degradation of the fungicide difenoconazole was examined in a silt loam soil under controlled conditions (60% WHC, 30 degrees C) in the laboratory. Difenoconazole was applied at 0.1 and 1.0 mg kg(-1) dry soil, respectively. The experiments were run with non-pretreated and pretreated field soil, respectively, partly mixed with easily decomposable organic matter (leaf powder). In all experiments, degradation curves showed a sigmoidal shape with clear acclimation phases. Pretreatment with difenoconazole in the field decreased the acclimation phases, DT(50)- and, in some cases, DT(90)-values. The incorporation of easily decomposable organic matter decreased both DT(50)- and DT(90)-values and increased the general microbial activity significantly. We conclude that difenoconazole is metabolized by an acclimated part of the soil microflora. However, the degradation seems to be stimulated in the presence of suitable co-substrates.     

Academic publishing in disaster risk reduction: past,present, and future

Nowadays there are approximately 80 Anglophone journals that deal primarily with disaster risk reduction (DRR) and allied fields. This large array signals a sustained, if uneven, growth in DRR scholarship but also competition between the offerings of different publishers and institutions. The purpose of this article is first to summarise the development of academic publishing on DRR from its early beginnings to the present day. The paper then evaluates the current state of publishing in this field and discusses possible future trends. Next, it identifies some possible opportunities, challenges, expectations, and commitments for journal editors both within DRR and academia more broadly, including those that refer to changes in the use of terminology, the relentless increase in the number of papers submitted, the expansion and dangers of predatory journals, different peer review models, open access versus paywalls, citations and bibliography metrics, academic social networks, and copyright and distribution issues.