Charting a course for freshwater biomonitoring: the grand challenges identified by the global scientific community

The past 50 years have seen biomonitoring emerge as an essential means of generating the knowledge needed to inform protection and restoration of freshwater ecosystems. Despite the successes of biomonitoring, most freshwater ecosystems remain unmonitored. Moreover, degradation of freshwaters continues at a rapid rate with new threats and novel stressors emerging that are difficult to assess using existing techniques. New technologies and techniques have been developed to improve biomonitoring, but application has been slow and integration with existing approaches is often problematic. Clearly, freshwater biomonitoring faces many important challenges that must be addressed to meet management needs of the coming decades. We identify Grand Challenges facing freshwater biomonitoring with the aim of encouraging research and practice to address these challenges. We asked 256 biomonitoring scientists from around the globe to identify what they considered the most important challenges. From their submissions we established five Grand Challenges and 18 associated subchallenges. For each Grand Challenge, we outline the current state of biomonitoring practice and suggest promising pathways and approaches to address them. By identifying and describing these challenges, we strive to position freshwater biomonitoring to take advantage of emerging opportunities and enhance its capacity to meet current and future management needs

Regulation of a Sulfur-Controlled Protease in <i>Neurospora crassa</i>

Wild-type Neurospora crassa produces and secretes extracellular protease(s) when grown on a medium containing a protein as its principle sulfur source. Readily available sulfur sources, such as sulfate or methionine, repress the synthesis of the proteolytic activity. Preliminary characterization of the proteolytic enzyme shows it to have a molecular weight of about 31,000, a pH optimum of 6 to 9 with casein as substrate, and esterolytic activity against acetyl-tyrosine ethyl ester with a pH optimum of 8.5. The enzyme activity is completely inhibited by diisopropylfluorophosphate, partially inhibited by ethylenediaminetetraacetate, but unaffected by iodoacetate. The proteolytic activity is temperature labile and is reduced by 75% within 15 min at 60 C. Synthesis of the protease activity is induced by proteins, and to a lesser extent by large-molecular-weight polyamino acids, but not at all by small peptides or amino acid mixtures. During conidial out-growth, the protease(s) first appears at about 8 h and continues to increase while the cells are in an active growth phase. When a low concentration of sulfate is present, the protease(s) is not produced until about 18 h, suggesting that the sulfate must first be used by the cells before the protease is either synthesized or released. </jats:p

West Nile Region, Uganda - Integrated and Multi Scalar Planning (Koboko, Arua, Nebbi)

Arua, due to its strategic geographical position, is a rapidly growing urban centre in Ugandan West Nile region and an important base for humanitarian operations. Refugees from South Sudan and the Democratic Republic of Congo (DRC) currently form 23% of the regional population, with around 700.000 registered refugees (UNHCR, 2018) and unregistered migrants contributing to the figures The Ugandan Government plans to upgrade Arua to a “regional city”, to include the enlargement of its boundaries and the enhancement of air and rail infrastructure among others, envisioning it as a potential logistic node for North-Western Uganda. However, no strategic framework is provided at regional, city or neighbourhood scales to promote a synergic development with neighbouring towns (Koboko and Nebbi), districts and countries (DRC and South Sudan). Although rapid urbanization is already threatening existing socio-ecological assets and increasing conflict potential related to land rights and access to basic infrastructure and services, there is a lack of appropriate assessment and strategic tools to address the complex transformation of these territories. Moving from the results of previous capacity development initiatives in the framework of the Ugandan Support for Municipal Infrastructure Development (USMID) program, a project for a comprehensive profiling of the region across different planning scales has been initiated by UNHabitat in August 2018 with the financial support from the Booyoung Foundation, with the aim of supporting a better understanding of the West Nile Region as a metropolitan system along the Nebbi-AruaKoboko development corridor. Among other priorities, exploring how decision making at territorial scale would also influence city and neighbourhood level was in the focus of the regional profile. Politecnico di Milano has been selected as the implementing partner with UN-Habitat to draft a multidisciplinary analysis of the existing situation at regional and territorial scale, including development of specific metropolitan cartography, while UN-Habitat’s Public Space and Urban Economy teams have conducted in-dept research on urban economy and municipal finance, as well as a public space assessment and recommendations at neighbourhood scale in each municipality. This report outlines the results of the research activity, including desktop research and field studies, complemented by a factfinding mission and workshops held in the West Nile Region in October and November 2018 for the effective interaction with local experts and stakeholders, at both national and local level. The following chapters synthesize main findings with the aim of providing a set of recommendations

Structural and functional features of modified heat stable toxin produced by entheropathogenic Klebsiella cells

Heat-stable enterotoxins (STs) are 18- or 19-amino acid peptides (STa or ST1) produced by enteropathogenic bacteria with small differences in their amino acid sequence and a highly conserved carboxy terminus. All STs contain a core of three disulfide bridges whose integrity is believed to be necessary for full biologic activity. We previously reported that strains of Klebsiella pneumoniae transformed by the plasmid pSLM004 produce a modified toxin not recognized by MAb raised against genuine Escherichia coli ST. Investigation of the chemical structure of the modified toxins revealed that three new toxins were present. These were purified to homogeneity by a series of sequential chromatography on reverse-phase columns using guanylate cyclase to monitor the enterotoxic activity during purification procedures. The sequence of the modified toxins was obtained by a combination of Edman degradation and mass spectrometry, showing that they are proteolytically processed forms of E. coli ST1b. In particular, toxin A-2 lacks the cysteine at position 18 and then is not able to form the disulfide bridge cysteine-10-cysteine-18. All three toxins showed the ability to stimulate guanylate cyclase and to elicit chloride secretion in Caco-2 cell monolayers mounted in Ussing chambers. Toxin A-1 and toxin B demonstrated greatly reduced immunoreactivity whereas toxin A-2 was not recognized at all in the ELISA. It is likely that the three modified toxins were generated by Klebsiella specific proteolytic processing of the original pretoxin. These results have important implications for the diagnosis and prevention of heat-stable toxin-induced diarrhea