CONTEXT MATTERS: THE IMPORTANCE OF MARKET CHARACTERISTICS IN THE VOLATILITY OF FEEDSTOCK COSTS FOR BIOGAS PLANTS.

Recently, biogas plant managers in Flanders face increased financial uncertainty. Between 2011 and 2012, 20% of the Flemish biogas plants went bankrupt. Difficulties in obtaining feedstock at stable and affordable prices is one reason why the biogas sector struggles. In literature, contracting is often proposed as a way to decrease the volatility of the feedstock costs. However, these studies generally do not consider the context in which the biogas plant manager needs to buy the feedstock. Yet, this context could be of specific importance when biogas plant managers are in competition with other users of the same biomass type. Silage maize is an example of such a feedstock, as it is both used by dairy farmers and biogas plant managers. Using a combination of qualitative research and agent-based modelling, we investigated the effect of specific characteristics of the silage maize market on the acquisition of local silage maize by biogas plant managers. This paper details the institutional arrangements of the silage maize market in Flanders and the results of a scenario analysis, simulating three different scenarios. As shown by the results, the time of entry into the market, as well as the different institutional arrangements used by the biogas plant managers as opposed to dairy farmers could explain the difficulties in obtaining a stable supply of local silage maize by biogas plants. Our findings can help to develop mitigation strategies addressing these difficulties.

Massive perinatal left ventricle infarction treated with tissue plasminogen activator: No ECMO - A case report.

Neonatal myocardial infarction due to coronary thrombus is a rare cause of acute heart failure and is associated with high morbidity and mortality. We present a rare case of a full-term newborn who developed coronary artery thrombus treated with intracoronary recombinant tissue plasminogen activator infusion while undergoing therapeutic hypothermia. Also, we describe a unique treatment strategy to support systemic circulation sparing the patient from neonatal extracorporeal membrane oxygenation and its complications. Neonatal myocardial infarction should be suspected and ruled out in sick newborns.

Increasing the quantity of separated post-consumer plastics for reducing combustible household waste: The case of rigid plastics in Flanders.

In Flanders, Belgium, rigid and soft plastics represent an interesting fraction of residual household waste as a potential 80 000 Gg a-1 can be recycled instead of incinerated. Removing a large amount of rigid packaging and non-packaging plastics from the residual household waste fraction could contribute to the goal to reduce the amount of residual household waste to less than 150 kg capita-1 a-1 for the Flemish region, where currently only 20% of plastics are collected selectively in drop-off facilities. Given the wide range of plastic separation schemes across the region, it is the aim of this paper to identify whether the applied separation options have an impact on the quantity of separated plastics, and, moreover, which scheme is able to separate most plastics. Cross-sectional data for the period 2008-2012 were collected for all 308 Flemish municipalities to conduct a regression analysis. The results of the analysis show that the quantity of separated plastics differs significantly between the different separation schemes used. If municipalities change their separation schemes, Flanders as a whole would be able to collect more plastic waste to better comply with its own objectives and EU regulation on recycling. Improved separation-at-source recycling initiatives, by applying the appropriate separation scheme for plastics, may increase recycling growth.

A targeted mutagenesis system for Actinobacillus pleuropneumoniae.

We describe methods for the mutagenesis of cloned Actinobacillus pleuropneumoniae (Ap) genes and for the construction of Ap mutants by allelic exchange. We used these methods to construct isogenic mutants of Ap which no longer synthesized a 48-kDa outer membrane protein (AopA). The native aopA locus was replaced with a mutated locus that had been inactivated by insertion of a gene (KmR) encoding kanamycin resistance from Tn903. The inactivated aopA locus was cloned into a conjugative, R6K-derived, lambda pir-dependent suicide vector and introduced into Ap using a filtermating technique. Southern and Western blot analyses indicated that the wild-type locus was replaced by the mutated locus through either single- or double-crossover events, and that AopA was no longer produced by either type of mutant. These methods were used successfully to construct AopA- mutants in Ap serotypes 1 and 5. These methods should be generally useful in constructing mutant loci which can be used to analyze the roles of various Ap genes in the pathogenesis of contagious pleuropneumonia in swine.

The role of genomics in antibacterial target discovery.

Complete DNA sequence information has now been obtained for several prokaryotic genomes, defining the entire genetic complement of these organisms. The collection of genomic data has provided new insights into the molecular architecture of bacterial cells, revealing the basic genetic and metabolic structures that support viability of the organisms. Genomic information has also revealed new avenues for inhibition of bacterial growth and viability, expanding the number of possible drug targets for antibiotic discovery. This review examines how genomic sciences and experimental tools are applied to antibacterial target discovery, the necessary first step in the development of new antibiotic classes. Significant advances have been realized in the development of functional genomic, comparative genomic, and proteomic methods for the analysis of completed genomes. The combination of these methods can be used to systematically parse the genome and identify targets worthy of inhibitor screens. Two basic categories of targets emerge from this exercise, comprising in vitro essential targets required for bacterial viability on synthetic media and in vivo essential targets required to establish and maintain infection within a host organism. Current use of genomic information is focused primarily on a definition of all in vitro essential targets that satisfy criteria of selectivity, spectrum, and novelty. As the genomes of additional bacterial pathogens are solved, it will be possible to select in vivo essential targets common to groups of select pathogens (e.g., bacterial agents of community acquired pneumonia) or even pathogen-specific targets. Consideration of host-pathogen interactions, defined at the level of gene expression for each organism, might provide novel therapeutic options in the future.

The compact disk as radon detector--a laboratory study of the method.

The radon absorption ability and the track etch properties of the polycarbonate material of commercial compact disks make them very useful as sensitive retrospective 222Rn detectors. The basic idea is to remove, after exposure, a surface layer that is thicker than the range of the alpha particles of the 222Rn and 220Rn progenies and to count the electrochemically etched tracks at the corresponding depths (>80 microm). The effects on the response due to differences in pressure, temperature, and humidity have been studied experimentally. The effect of the growing of 210Po after long-term exposures was also estimated. The effect of all listed factors except the temperature is either absent or restricted to maximum--about 10% for the very extreme cases. The variation of the response at 83 microm depth over the temperature interval 15-25 degrees C is +/-12% around the 20 degrees C value. The dependence of the calibration factor on the etched depth beneath the surface was studied at 4 different temperatures within the range expected indoors. The results show that the depth dependence is exponential with the parameters of the exponent also being dependent on the temperature. In practice, using the track density obtained in two or more depths beneath the compact disk's front surface, an a posteriori temperature correction could be made. By this correction it is possible to substantially reduce the bias in the results due to the unknown temperature during exposure. The results imply that by using home stored compact disks long-term retrospective 222Rn measurements could be made with an uncertainty that could be potentially better than 10%. The useful range of the method starts at about 3 Bq m(-3) (for 10 y exposure time) and appears to cover practically the whole range of indoors 222Rn concentrations.

Survey of the 137Cs contamination in Belgium by in-situ gamma spectrometry, a decade after the Chernobyl accident.

The residual radiocesium concentration, nearly 10 y after the Chernobyl accident, is measured at different sites on the Belgian territory by means of in-situ gamma-spectrometry. A possible link between the rainfall at the beginning of May 1986 and the actual cesium concentration is investigated. The radiological impact of this contamination, even in the most affected regions in the Ardennes, is very small (<6 microSv y(-1)).

Short-lived alpha sources of energies 6.0 MeV and 7.69 MeV for calibration purposes.

An approach for preparation of short-lived alpha sources of energy 6.0 MeV and 7.69 MeV is proposed. The sources are prepared by taking a sample of 222Rn progeny on an alpha spectrometric filter. The activities (or related parameters) of 218Po, 214Pb and 214Bi at the end of sampling are precisely determined by a reference measurement with an alpha spectrometer. Further they are used as input values to calculate with a sufficient precision the number of emitted alpha particles of any energy and at any time interval of interest. Theoretical modelling and experimental results demonstrated that such sources could be prepared with a sufficient purity. There is a potential for the number of alpha particles emitted in a given time interval to be certified with an accuracy of 1-2%.

Cost comparison between private and public collection of residual household waste: multiple case studies in the Flemish region of Belgium.

The rising pressure in terms of cost efficiency on public services pushes governments to transfer part of those services to the private sector. A trend towards more privatizing can be noticed in the collection of municipal household waste. This paper reports the findings of a research project aiming to compare the cost between the service of private and public collection of residual household waste. Multiple case studies of municipalities about the Flemish region of Belgium were conducted. Data concerning the year 2009 were gathered through in-depth interviews in 2010. In total 12 municipalities were investigated, divided into three mutual comparable pairs with a weekly and three mutual comparable pairs with a fortnightly residual waste collection. The results give a rough indication that in all cases the cost of private service is lower than public service in the collection of household waste. Albeit that there is an interest in establishing whether there are differences in the costs and service levels between public and private waste collection services, there are clear difficulties in establishing comparisons that can be made without having to rely on a large number of assumptions and corrections. However, given the cost difference, it remains the responsibility of the municipalities to decide upon the service they offer their citizens, regardless the cost efficiency: public or private.

Non-cereal food consumption, food insecurity and nutritional status of children and mothers: a case study in Bangladesh.

AIM: The aim of this study is to investigate the effects of food insecurity derived from non-cereal food consumption on nutritional status of children and mothers in a poverty-prone region in Bangladesh. METHODS: Data from the Bangladesh Nutritional Surveillance Project, 2005 of Helen Keller International were used to relate non-cereal food consumption and household food insecurity to nutritional status of children and their mothers. Multiple regressions were used to determine the association between the nutritional outcomes and the explanatory variables. In the case of binary and multi-level outcomes, logistic regressions were used as well. RESULTS: Non-cereal dietary diversity was found to have little predictive power on BMI and MUAC of mothers and on the nutritional status of the children. Maternal education is strongly associated with mothers' and children's nutritional status. CONCLUSION: Dietary diversity based on non-cereal food consumption can be a useful tool to investigate the nutritional status of poor households, but more studies are needed to verify these findings.

The phospholipase A(2) inhibitor methyl indoxam suppresses diet-induced obesity and glucose intolerance in mice.

BACKGROUND AND PURPOSE: Previous results have shown that mice lacking in the group 1B phospholipase A(2) (Pla2g1b) are resistant to obesity and diabetes induced by feeding a diabetogenic high-fat/high-carbohydrate diet. This study examined the potential of using the Pla2g1b inhibitor methyl indoxam as therapy to suppress diet-induced obesity and diabetes. EXPERIMENTAL APPROACH: Male C57BL/6 mice were fed the diabetogenic diet with or without methyl indoxam supplementation. Body weight gain, fasting plasma glucose levels, glucose tolerance and postprandial lysophospholipid absorption were compared. KEY RESULTS: Wild-type C57BL/6 mice fed the diabetogenic diet without Pla2g1b inhibitor showed 31 and 69% body weight gain after 4 and 10 weeks respectively. These animals also showed elevated plasma glucose levels and were glucose intolerant. In contrast, C57BL/6 mice fed the diabetogenic diet with 90 mg.kg(-1) of methyl indoxam gained only 5% body weight after 10 weeks. These animals were also euglycaemic and displayed normal glucose excursion rates in glucose tolerance test. Methyl indoxam suppression of diet-induced body weight gain and glucose intolerance was correlated with the inhibition of Pla2g1b-mediated postprandial lysophospholipid absorption. CONCLUSIONS AND IMPLICATIONS: These results show that oral supplementation of a diabetogenic diet with the Pla2g1b inhibitor methyl indoxam effectively suppresses diet-induced obesity and diabetes in mice. This suggests that Pla2g1b inhibition may be a potentially effective oral therapeutic option for treatment of obesity and diabetes.

Non-Cereal Food Consumption, Food Insecurity and Nutritional Status of Children and Mothers: A Case Study in Bangladesh

Aim: The aim of this study is to investigate the effects of food insecurity derived from non-cereal food consumption on nutritional status of children and mothers in a poverty-prone region in Bangladesh. Methods: Data from the Bangladesh Nutritional Surveillance Project, 2005 of Helen Keller International were used to relate non-cereal food consumption and household food insecurity to nutritional status of children and their mothers. Multiple regressions were used to determine the association between the nutritional outcomes and the explanatory variables. In the case of binary and multi-level outcomes, logistic regressions were used as well. Results: Non-cereal dietary diversity was found to have little predictive power on BMI and MUAC of mothers and on the nutritional status of the children. Maternal education is strongly associated with mothers’ and children’s nutritional status. Conclusion: Dietary diversity based on non-cereal food consumption can be a useful tool to investigate the nutritional status of poor households, but more studies are needed to verify these findings.

Formation of type II F-primes from unstable Hfrs and their recA-independent conversion to other F-prime types.

Four E. coli Hfr strains, representing stable (Hfr Cavalli), moderately stable (AB312) and unstable (Ra-1, Ra-2) Hfr states, were used in the isolation of a series of F' plasmids. Type II F's were found to be the most prevalent F' plasmid formed from all of the Hfrs, while the percentages of delta tra F's increased as the stability of the Hfr increased. Two observations suggested that F' formation in unstable Hfrs like Ra-2 may proceed through a type II F' precursor. First, the major F' products of Ra-2 are tra+ type II F's and, second, other F' types (I, II) and classes (tra+, delta tra) from Ra-2 appeared to be deletion derivatives of a larger F' progenitor. By monitoring the molecular changes that occur when the Ra-2 derived type II F' pWS200 is transferred from one recA host to another, we have found that all F' types and classes can be generated from pWS200 in a recA-independent manner. F sequences involved in the genetic conversions of pWS200 include the oriT locus and the directly repeated gamma delta junctions of F and chromosomal DNA. A model for the formation of F's in unstable Hfrs is postulated in which a tra+ type II F' primary excision product is seen to be modified, through recA-independent processes, to other F' types and classes. This model differs from the current model of F' formation in that independent excision events from the Hfr chromosome are not seen as the source of type I and type II F's. These studies have also shown that the formation of delta tra F's is a recA-independent process that can occur from the F' and Hfr states, that gamma delta-mediated deletions in pWS200 often demonstrate regional specificity in having endpoints near the ilv operon and that genetic alterations in either replication origin of pWS200 (F oriV, chromosomal oriC) stabilize the replication of this "mini-Hfr" cointegrate.

Sequence variation in two ipaH genes of Shigella flexneri 5 and homology to the LRG-like family of proteins.

Oligonucleotide primers derived from the ipaH7.8 sequence have been used to determine the boundaries of DNA sequence homology among five ipaH genes on the invasion plasmid (pWR100) of Shigella flexneri 5, strain M9OT-W. The primary structure of IpaH4.5 has been established from DNA sequence analysis. The first 197 amino acids in IpaH7.8 were replaced in IpaH4.5 by a unique set of 251 amino acids, generating two related proteins with variable and conserved sequences. The amino-terminal region of IpaH4.5 displayed an internal repeat structure, also seen in IpaH7.8, characteristic of members of the leucine-rich glycoprotein (LRG) family. The DNA sequences of ipaH2.5 and ipaH1.4 indicate that these genes are truncated versions of ipaH7.8. Western blot analysis of a lambda gt11 ipaH recombinant (W7) subclone demonstrated that the antigenicity of IpaH7.8 resides outside the leucine-rich repetitive region.

Surface presentation of Shigella flexneri invasion plasmid antigens requires the products of the spa locus.

An avirulent, invasion plasmid insertion mutant of Shigella flexneri 5 (pHS1059) was restored to the virulence phenotype by transformation with a partial HindIII library of the wild-type invasion plasmid constructed in pBR322. Western immunoblot analysis of pHS1059 whole-cell lysates revealed that the synthesis of the invasion plasmid antigens VirG, IpaA, IpaB, IpaC, and IpaD was similar to that seen in the corresponding isogenic S. flexneri 5 virulent strain, M90T. IpaB and IpaC, however, were not present on the surface of pHS1059 as was found in M90T, suggesting that the transport or presentation of the IpaB and IpaC proteins onto the bacterial surface was defective in the mutant. pHS1059 was complemented by pWR266, which carried contiguous 1.2- and 4.1-kb HindIII fragments of the invasion plasmid. pHS1059(pWR266) cells were positive in the HeLa cell invasion assay as well as colony immunoblot and enzyme-linked immunosorbent assays, using monoclonal antibodies to IpaB and IpaC. These studies established that the antigens were expressed on the surface of the transformed bacteria. In addition, water extraction of pHS1059 and pHS1059(pWR266) whole cells, which can be used to remove IpaB and IpaC antigens from the surface of wild-type M90T bacteria, yielded significant amounts of these antigens from pHS1059(pWR266) but not from pHS1059. Minicell and DNA sequence analysis indicated that several proteins were encoded by pWR266, comprising the spa loci, which were mapped to a region approximately 18 kb upstream of the ipaBCDAR gene cluster. Subcloning and deletion analysis revealed that more than one protein was involved in complementing the Spa- phenotype in pHS1059. One of these proteins, Spa47, showed striking homology to ORF4 of the Bacillus subtilis flaA locus and the fliI gene sequence of Salmonella typhimurium, both of which bear strong resemblance to the alpha and beta subunits of bacterial, mitochondrial, and chloroplast proton-translocating F0F1 ATPases.

Shigella flexneri invasion plasmid antigens B and C: epitope location and characterization with monoclonal antibodies.

Invasion plasmid antigens B (IpaB) and C (IpaC) are associated with the ability of shigellae to invade cultured mammalian cells. Monoclonal antibodies against IpaB and IpaC polypeptides were produced and used in a whole-cell enzyme-linked immunosorbent assay to show that both IpaB and IpaC polypeptides were exposed on the surface of virulent shigellae. Moreover, these surface epitopes were shown to be highly conserved among different serotypes of Shigella spp. and enteroinvasive Escherichia coli. Cross-reactive epitopes were not found on noninvasive Shigella strains or on other enteric bacteria including Salmonella, Yersinia, Campylobacter, Vibrio, and Aeromonas spp. and various pathogenic strains of E. coli. The monoclonal antibodies were used in competitive binding assays to define three unique epitopes of the IpaB polypeptide and four unique epitopes of the IpaC polypeptide. Epitope locations and their corresponding DNA-encoding regions were defined by examining the IpaB and IpaC products expressed by lambda gt11 recombinants and by constructing a genetic map of the insert DNAs of these recombinants. Three IpaB epitopes (2F1, 1H4, 4C8) were found to be encoded on three contiguous DNA regions comprising a 700-base-pair (bp) segment that corresponded to the amino-terminal end of the IpaB polypeptide. Similarly, a 640-bp DNA segment that corresponded to the amino-terminal end of the IpaC polypeptide was found to encode three clustered IpaC epitopes (5H1, 9B6, 5B1). Approximately 50 bp downstream from this region a fourth IpaC epitope-encoding region (2G2) was found. The effect of the monoclonal antibodies on plaque formation by virulent Shigella flexneri on a monolayer of cultured mammalian cells (a sensitive measure of invasiveness) was determined. Only the IpaB-specific monoclonal antibody 2F1 was able to reduce the plaque-forming capacity by greater than 50%, suggesting that this epitope of the IpaB polypeptide is involved in the invasion process.