Impact of intervention strategies on Listeria contamination patterns in crawfish processing plants: a longitudinal study

Two ready-to-eat crawfish processing plants were monitored for 2 years to study the impact of Listeria control strategies, including employee training and targeted sanitation procedures, on Listeria contamination. Environmental, raw material, and finished product samples were collected weekly during the main processing months (April to June) and tested for Listeria spp. and Listeria monocytogenes. Before implementation of control strategies (year 1), the two processing plants showed Listeria spp. prevalences of 29.5% (n = 78) in raw, whole crawfish, 5.2% (n = 155) in the processing plant environment, and 0% (n = 78) in finished products. In year 2, after plant-specific Listeria control strategies were implemented, Listeria spp. prevalence increased in raw crawfish (57.5%, n = 101), in the processing plant environment (10.8%, n = 204), and in the finished product (1.0%, n = 102). Statistical analysis showed a significant increase in Listeria spp. prevalence (P < 0.0001) and a borderline nonsignificant increase in L. monocytogenes prevalence (P = 0.097) on raw material in year 2. Borderline nonsignificant increases were also observed for Listeria spp. prevalence in environmental samples (P = 0.082). Our data showed that Listeria spp. prevalence in raw crawfish can vary significantly among seasons. However, the increased contamination prevalence for raw materials only resulted in a limited Listeria prevalence increase for the processing plant environment with extremely low levels of finished product contamination. Heat treatment of raw materials combined with Listeria control strategies to prevent cross-contamination thus appears to be effective in achieving low levels of finished product contamination, even with Listeria spp. prevalences for raw crawfish of more than 50%.     

Genetic diversity of Oenoccoccus oeni isolated from wines treated with phenolic extracts as antimicrobial agents

Molecular techniques have been applied to study the evolution of wine-associated lactic acid bacteria from red wines produced in the absence and presence of antimicrobial phenolic extracts, eucalyptus leaves and almond skins, and to genetically characterize representative Oenococcus oeni strains. Monitoring microbial populations by PCR-DGGE targeting the rpoB gene revealed that O. oeni was, as expected, the species responsible for malolactic fermentation (MLF). Representative strains from both extract-treated and not-treated wines were isolated and all were identified as O. oeni species, by 16S rRNA sequencing. Typing of isolated O. oeni strains based on the mutation of the rpoB gene suggested a more favorable adaptation of L strains (n = 63) than H strains (n = 3) to MLF. Moreover, PFGE analysis of the isolated O. oeni strains revealed 27 different genetic profiles, which indicates a rich biodiversity of indigenous O. oeni species in the winery. Finally, a higher number of genetic markers were shown in the genome of strains from control wines than strains from wines elaborated with phenolic extracts. These results provide a basis for further investigation of the molecular and evolutionary mechanisms leading to the prevalence of O. oeni in wines treated with polyphenols as inhibitor compounds.     

Interferon-β Activity Is Affected by S100B Protein

Interferon-β (IFN-β) is a pleiotropic cytokine secreted in response to various pathological conditions and is clinically used for therapy of multiple sclerosis. Its application for treatment of cancer, infections and pulmonary diseases is limited by incomplete understanding of regulatory mechanisms of its functioning. Recently, we reported that IFN-β activity is affected by interactions with S100A1, S100A4, S100A6, and S100P proteins, which are members of the S100 protein family of multifunctional Ca²⁺-binding proteins possessing cytokine-like activities (Int J Mol Sci. 2020;21(24):9473). Here we show that IFN-β interacts with one more representative of the S100 protein family, the S100B protein, involved in numerous oncological and neurological diseases. The use of chemical crosslinking, intrinsic fluorescence, and surface plasmon resonance spectroscopy revealed IFN-β binding to Ca²⁺-loaded dimeric and monomeric forms of the S100B protein. Calcium depletion blocks the S100B–IFN-β interaction. S100B monomerization increases its affinity to IFN-β by 2.7 orders of magnitude (equilibrium dissociation constant of the complex reaches 47 pM). Crystal violet assay demonstrated that combined application of IFN-β and S100B (5–25 nM) eliminates their inhibitory effects on MCF-7 cell viability. Bioinformatics analysis showed that the direct modulation of IFN-β activity by the S100B protein described here could be relevant to progression of multiple oncological and neurological diseases.     

In Vivo Evaluation of Sgc8-c Aptamer as a Molecular Imaging Probe for Colon Cancer in a Mouse Xenograft Model

Recent biotechnological applications in the field of clinical oncology led to the identification of new biomarkers as molecular targets of cancer, and to broad developments in the field of personalized medicine. Aptamers are oligonucleotides (ssDNA or RNA) that are selected to specifically recognize a molecular target with high affinity and specificity. Based on this, new horizons for their use as molecular imaging probes are being explored. The objective of this work was to evaluate the Sgc8-c aptamer conjugated with Alexa Fluor 647 fluorophore as an imaging probe in a colon tumor xenograft mouse model, with potential application in molecular imaging. In this study, the LS174T cell line was used to induce colorectal adenocarcinoma in nude mice. After confirmation of PTK7 overexpression by immunohistochemistry, in vivo studies were performed. Pharmacokinetic, in vivo and ex vivo biodistribution imaging, and a competition assay were evaluated by fluorescence imaging. In vivo visualization of the probe in the tumors was assessed two hours after aptamer probe administration, exhibiting excellent tumor-to-background ratios in biodistribution studies and high specificity in the competition test. Our results demonstrated the functionality of Scg8-c as an imaging probe for colon cancer, with potential clinical applications.     

Residential mobility of low-income,subsidized households: a synthesis of explanatory frameworks

Mobility, residential quality, and life outcomes are linked in the literature and these relationships have influenced low-income housing policy. This research investigates the determinants of mobility for households with a federal housing subsidy. Combining unique data from a survey of Housing Choice Voucher households, client program files, and secondary data, this study uses logistic regression to test several explanations for mobility, including the life cycle, housing market perceptions, and perceived and actual neighborhood conditions. The results indicate that a synthesis of explanations produce the best model to predict residential mobility. Neighborhood quality, perceived and actual, variables most strongly influence mobility, but life cycle factors and perception of the local housing market also impact moving choices. At the same time, the results suggest a gap in our understanding of the relationship among individuals’ environmental perceptions, formation of feelings of neighborhood satisfaction, and actual neighborhood conditions. The article concludes with a discussion of the research and policy implications from this study.     

How much do water deficits alter the nitrogen nutrition status of forage crops?

Water deficits alter the nitrogen nutrition of crops. In grasslands, this has a major impact on both forage yield and nitrogen fluxes in the soil. It is important to assess the N balance in order to adjust fertilization to the expected needs of the crop and thus minimize any environmentally negative impacts of crops. Grassland species, including grasses, display a diverse ability to utilise soil resources. Nitrogen fluxes and the nitrogen absorption by grass swards of two species with contrasting rooting depths were computed using the appropriate module from the STICS simulation platform. In the case of the deep-rooted species, tall fescue, soil mineral N fluxes to the roots were very close to N uptake values, consistent with its nitrogen nutrition index being lower than one. In the case of the shallow-rooted species Italian ryegrass, there was a large excess in terms of N supply, which was also consistent with its non-limiting nitrogen nutrition index. In both species, and even when nitrogen demands for growth were fully satisfied, the nitrogen nutrition index was closely and linearly related to the soil mineral N flux to roots.     

HPLC confirmatory method development for the determination of seven quinolones in salmon tissue (Salmo salar L.) validated according to the European Union Decision 2002/657/EC

A confirmatory high pressure liquid chromatographic method for the determination of seven quinolone antibiotics in tissue of Atlantic salmon (Salmo salar L.) was developed. Ciprofloxacin (CIP), danofloxacin (DAN), enrofloxacin (ENR), sarafloxacin (SAR), oxolinic acid (OXO), nalidixic acid (NAL) and flumequine (FLU) were separated on a Perfectsil ODS-2 120 (250 mm × 4 mm, 5 μm) column by gradient elution with a mobile phase consisting of 0.1% trifluoroacetic acid (pH = 1), acetonitrile and methanol at 25 °C within 22 min. Analytes were monitored at 255 nm (for the determination of OXO, NAL and FLU) and 275 nm (for CIP, DAN, ENR and SAR) by means of photodiode array detector. Examined quinolones were isolated from salmon tissue by extraction with citrate buffer solution (pH = 4.7) and purified by solid phase extraction using Oasis HLB (200 mg/6 mL) cartridges. The developed method was fully validated in terms of selectivity, linearity, accuracy, precision, stability and sensitivity according to the European Union Decision 2002/657/EC. The accuracy of the method was additionally proved by its application to certified reference material of salmon tissue (BCR® 725).     

Natural and human forcing in recent geomorphic change; case studies in the Rio de la Plata basin

An analysis of geomorphic system's response to change in human and natural drivers in some areas within the Río de la Plata basin is presented. The aim is to determine whether an acceleration of geomorphic processes has taken place in recent years and, if so, to what extent it is due to natural (climate) or human (land-use) drivers. Study areas of different size, socio-economic and geomorphic conditions have been selected: the Río de la Plata estuary and three sub-basins within its watershed. Sediment cores were extracted and dated (²¹⁰Pb) to determine sedimentation rates since the end of the 19th century. Rates were compared with time series on rainfall as well as human drivers such as population, GDP, livestock load, crop area, energy consumption or cement consumption, all of them related to human capacity to disturb land surface. Data on river discharge were also gathered. Results obtained indicate that sedimentation rates during the last century have remained essentially constant in a remote Andean basin, whereas they show important increases in the other two, particularly one located by the São Paulo metropolitan area. Rates in the estuary are somewhere in between. It appears that there is an intensification of denudation/sedimentation processes within the basin.Rainfall remained stable or varied very slightly during the period analysed and does not seem to explain increases of sedimentation rates observed. Human drivers, particularly those more directly related to capacity to disturb land surface (GDP, energy or cement consumption) show variations that suggest human forcing is a more likely explanation for the observed change in geomorphic processes. It appears that a marked increase in denudation, of a “technological” nature, is taking place in this basin and leading to an acceleration of sediment supply. This is coherent with similar increases observed in other regions.     

Computational evolutionary inverse lagrangian puff model

This article presents a model based on the principles of evolutionary computation and on the principles of dispersion of an Inverse lagrangian puff model of the type Backward gaussian puff tracking in order to determine the spatial behavior over time of the concentration for PM_2.5 and PM₁₀ in a study area.     

Developing BP-driven web applications through the use of MDE techniques

Model driven engineering (MDE) is a suitable approach for performing the construction of software systems (in particular in the Web application domain). There are different types of Web applications depending on their purpose (i.e., document-centric, interactive, transactional, workflow/business process-based, collaborative, etc). This work focusses on business process-based Web applications in order to be able to understand business processes in a broad sense, from the lightweight business processes already addressed by existing proposals to long-running asynchronous processes. This work presents a MDE method for the construction of systems of this type. The method has been designed in two steps following the MDE principles. In the first step, the system is represented by means of models in a technology-independent manner. These models capture the different aspects of Web-based systems (these aspects refer to behaviour, structure, navigation, and presentation issues). In the second step, the model transformations (both model- to-model and model-to-text) are applied in order to obtain the final system in terms of a specific technology. In addition, a set of Eclipse-based tools has been developed to provide automation in the application of the proposed method in order to validate the proposal.