NODAL COSINE SINE MATERIAL INTERPOLATION IN MULTI OBJECTIVE TOPOLOGY OPTIMIZATION WITH THE GLOBAL CRITERIA METHOD FOR LINEAR ELASTO STATIC, HEAT TRANSFER, POTENTIAL FLOW AND BINARY CROSS ENTROPY SHARPENING

Topology optimization is typically used for suitable design suggestions for objectives like mean compliance, mean temperature, or model analysis. Some modern modeling technics in topology optimization require a nodal based material interpolation. Therefore this article is referred to a continuous material interpolation in topology optimization. To cover a smooth and differentiable density field, we address trigonometric shape functions which are infinitely differentiable. Furthermore, we extend a so-known global criteria method with a sharpening function based on binary cross-entropy, so that sharper solutions results. The proposed material interpolation is applied to different applications such as heat transfer, elasto static, and potential flow. Furthermore, these different objectives are together optimized using a multi-objective criterion.

Presence of Listeria monocytogenes in Ready-to-Eat (RTE) meat products sold at retail stores in Costa Rica and analysis of contributing factors

Listeria monocytogenes is a pathogenic bacterium associated with RTE meat products sold at the retail level. The objective of this research was to determine the prevalence of Listeria monocytogenes in RTE meat products sold at retail in Costa Rica and to study the factors associated with the levels of contamination; analyzed factors include hygienic practices within stores (cutting techniques, microbial contamination of products) and the behavior of the isolates (persistence against antimicrobials and transfer potential). A total of 190 samples of RTE meat products were collected and analyzed for the presence of coliforms and Listeria species. Isolates of L. monocytogenes were then evaluated in terms of resistance to disinfectants (quaternary ammonium compounds and chlorine) and their transfer potential from food contact surfaces (knife and cuttingboards). Overall Listeria spp. prevalence was 37,4% (71/190); L. innocua was present in 32,1% (61/190) of the products and L. monocytogenes was found in just 2,6% (5/190) of the samples. Most of the contaminated samples were cut with a knife at the moment of purchase (44,2%). When analyzing practices within the stores, it was observed that L. monocytogenes transfer from inoculated knife to “salchichón” was higher for samples cut right at the beginning of the experiment. Also, L. monocytogenes transfer from inoculated cuttingboards was independent of the number of slices but contamination from plastic was higher than wood. Regarding L. monocytogenes resistance to disinfectants, average reductions of 2,6 ± 1,1 log CFU/mL were detected after 6 minutes of exposure to 200 ppm of chlorine; however, chlorine resistance varied among the strains. Prevalence of L. monocytogenes in RTE meat products sold at retail could be associated with handling practices within the stores; further studies are necessary to estimate the impact of these practices on the overall risk for consumers.

Characterization of planktonic and biofilm fatty acid profiles and evaluation of their trophic transfer potential to Hyalella Azteca

Fatty acid (FA) composition between biofilms and batch planktonic cultures were compared for two bacterial species Pseudomonas aeruginosa and Staphylococcus aureaus. Biofilm cultures exhibited decrease in saturated fatty acids (SAFA) that potentially conform to a more fluidic biophysical membrane property. The amount of FA in the biofilms' extracellular polymeric substance was not sufficient to consider it having a major contribution to the observed differences between biofilms and batch planktonic cultures. While biofilm grazing by the amphipod Hyalella azteca was evident, only certain bacteria-specific FA appeared to have the potential to be retained (odd-number SAFA and branched-chain FA). H. azteca with diet strictly consisted of bacteria biofilms did not demonstrate significant changes in their nutritional condition in terms of ω-3 and ω-6 polyunsaturated fatty acids (PUFA): combined with the results from fasting trials, H. azteca appears to have the capacity to retain ω-3 and ω-6 PUFAs up to 10 days.

Characterization of planktonic and biofilm fatty acid profiles and evaluation of their trophic transfer potential to Hyalella Azteca

Fatty acid (FA) composition between biofilms and batch planktonic cultures were compared for two bacterial species Pseudomonas aeruginosa and Staphylococcus aureaus. Biofilm cultures exhibited decrease in saturated fatty acids (SAFA) that potentially conform to a more fluidic biophysical membrane property. The amount of FA in the biofilms' extracellular polymeric substance was not sufficient to consider it having a major contribution to the observed differences between biofilms and batch planktonic cultures. While biofilm grazing by the amphipod Hyalella azteca was evident, only certain bacteria-specific FA appeared to have the potential to be retained (odd-number SAFA and branched-chain FA). H. azteca with diet strictly consisted of bacteria biofilms did not demonstrate significant changes in their nutritional condition in terms of ω-3 and ω-6 polyunsaturated fatty acids (PUFA): combined with the results from fasting trials, H. azteca appears to have the capacity to retain ω-3 and ω-6 PUFAs up to 10 days.

On-Farm Anaerobic Digestion of Dairy Manure Reduces the Abundance of Antibiotic Resistance-Associated Gene Targets, and the Potential for Plasmid Transfer

The present study investigated the impact of on-farm anaerobic digestion on the abundance of enteric bacteria, antibiotic resistance-associated gene targets and the horizontal transfer potential of extended-spectrum β-lactamase (ESBL) genes. Samples of raw and digested manure were obtained from six commercial dairy farms in Ontario, Canada. Digestion significantly abated populations of viable coliforms in all six farms. Conjugative transfer of plasmids carrying β-lactamase genes from manure bacteria enriched overnight with buffered peptone containing 4 mg/l cefotaxime into a β-lactam sensitive gfp-labelled E. coli as a recipient strain was evaluated in patch matings. Digestion significantly decreased the frequency of the horizontal transfer potential of ESBL genes. Twenty-five transconjugants were sequenced revealing six distinct plasmids with a size range of 40 – 180kb. A variety of ESBL genes were identified: blaCTX-M-1, blaCTX-M-14, blaCTX-M-15, blaCTX-M-27, blaCTX-M-55, blaPER-1. The blaCTX-M-15 was the most prevalent ESBL gene detected on plasmids harboured by transconjugants. Various mobile genetic elements were found located proximal to resistance genes. Ten gene targets including sul1, strA, strB, ermB, ermF, intI1, aadA, incW, blaPSE and blaOXA-20 were quantified by quantitative PCR on a subset of 18 raw and 18 digested samples. Most targets were significantly more abundant in raw manure, however ermB and ermF targets were more abundant in digested samples. Overall, on-farm digestion of dairy manure abated coliform bacteria, a number of antibiotic resistance-associated gene targets, and the potential for in vitro conjugation of plasmids conferring resistance to extended-spectrum β-lactams and other classes of antibiotics into E. coli CV601. IMPORTANCE Using livestock manure for fertilization can entrain antibiotic resistant bacteria into soil. Manure on some dairy farms is anaerobically digested before being land applied. Recommending the widespread implementation of the practice should be founded on understanding the impact of this treatment on various endpoints of human health concern. Although lab-scale anaerobic treatments have showed potential of reducing antibiotic resistance genes, there are very few data from commercial farms. Anaerobic digestion of manure on six dairy farms efficiently abated coliform bacteria and E. coli and a majority of antibiotic resistance-associated gene targets. In addition, the conjugation potential of plasmids carrying ESBL genes into introduced E. coli CV601 was reduced. Overall, anaerobic digestion abated coliform bacteria, the genes that they carry and the potential for ESBL-carrying plasmid transfer.

Sustainability Transfer as a Concept for Universities in Regional Transformation—A Case Study

The research object of this study is the in-depth discourse on the sustainability transfer activities of higher education institutions (HEIs) and their contribution to a regional sustainable transformation. For this purpose, a heuristically-derived concept of sustainability transfer is empirically tested with a mixed-methods approach based on the example of Eberswalde University for Sustainable Development (HNEE). The empirical findings demonstrate that the realization of sustainability transfer depends mainly on the personal initiative of teachers and researchers. Major barriers are a lack of time and financial resources. The observed concept of sustainability transfer is applicable to all study and research areas of HNEE. Involvement in sustainability transfer can include the whole of society, from politics, enterprises, and civil society to education and research institutions. Overall, the empirical testing of the concept offered by this study illustrates its practical suitability to capturing specifically those sustainability transfer activities that are not tapped by third mission approaches. This opens up a novel dimension for transfer potential at universities and their role in regional sustainability transformation. It also highlights that the interdependencies between HEIs and practitioners need to be more contextualized with quality criteria such as the value of the transfer performance or level of ambition.

ARB and ARGs survived from the extremely acidity posing a risk on intestinal bacteria in an in vitro digestion model by horizontal gene transfer

Background: Antibiotic resistance bacteria (ARB) and antibiotic resistance genes (ARGs) have been considered as emerging contaminants, which even might be closely related to human health.Methods: To investigate the disease-producing risk of ARB and the horizontal gene transfer (HGT) risks of both extracellular ARGs (eARGs) and intracellular ARGs (iARGs), an in vitro digestion model was established to simulate the process of ARB and ARGs going through digestive tract. CTC/DAPI-FCM assay was used to study the survival of ARB during digestion, and the changes of genes (including tetA, tetG, tetM, sul1, sul2, bla EBC, bla FOX, intI1 and 16S rRNA) were determined by QPCR.Results: The results showed that ARB were mostly affected by pH of gastric juice. About 99% ARB (total population of 2.45 × 109–2.54 × 109) were killed by the gastric juice of pH 2.0 for the severely damage of bacterial cell membrane, but more than 80% ARB (total population of 2.71 × 109–3.90 × 109) were still alive with intact cell membrane when the pH of gastric juice increased to 3.0 and above. ARGs, intI1 and 16S rRNA could be detectable even at extreme pH when most bacteria died. The eARGs (accounting for 0.03%–24.56% of total genes) were less than iARGs obviously. The eARGs showed greater HGT potential than that of iARGs, suggesting transformation occurs more easily than conjugation. The transfer potential followed the order as: tet (100%) > sul (75%) > bla (58%), related to the high correlation of intI1 with tetA and sul2 (p < 0.01). Moreover, gastric juice of pH 1.0 could decrease the transfer frequency of ARGs by 2–3 order of magnitude compared to the control, but still threatening human health.Conclusions: Under the treatment of digestive juice, ARGs still have high gene horizontal transfer potential, suggesting that food-borne ARB pose a risk of ARGs horizontal transfer to intestinal bacteria.