340 research outputs found

    Spatial and Temporal Variability in Zooplankton Community Dynamics in Three Urbanized Bayous of the Pensacola Bay System, Florida, USA

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    Spatial and temporal patterns in zooplankton community composition and abundance in coastal areas of the Gulf of Mexico are not well understood. Spatial and temporal differences in zooplankton community composition and abundance from 10 stations located in four sites are presented (Pensacola Bay and Bayou Texar, Bayou Chico, and Bayou Grande, three adjacent mesohaline-tidal bayous affected by urban and industrial development). Statistically significant differences (P \u3c 0.05) were found in log-biovolume among sites. The mean biovolume of zooplankton was highest in Pensacola Bay (0.38 ml m-3) followed by Bayou Grande (0.21 ml m-3), Bayou Chico (0.14 ml m-3), and Bayou Texar (0.06 ml m-3). Mean zooplankton abundances (organisms m-3) in Pensacola Bay (3,100 m-3) and Bayou Grande (3,000 m-3) were more than double the abundances in Bayou Texar (1,400 m-3) and Bayou Chico (1,100 m-3). The calanoid copepod Acartia tonsa Dana was the dominant species in the study area. The observed differences in the zooplankton community may be attributable to either one or a combination of factors such as water quality (toxicity), predation, and nutrient availability. Zooplankton abundance increased following two hurricanes that impacted the study area

    Pyrolysis-GC-MS for the Rapid Environmental Forensic Screening of Contaminated Brownfield Soil

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    An abandoned chemical plant in Asturias (Spain) was studied using a multi-faceted molecular fingerprinting approach, demonstrating that it is possible to: (1) carefully unravel tangled evidence resulting from multiple pollution sources, and (2) recognize major contaminants largely ignored by conventional analyses. This methodology employed a battery of GC-MS analyses of liquid chromatographic fractions of soil extracts, plus the pyrolysis products of the soil extract\u27s asphaltene fraction and the whole soil itself. In this example, coal tar distillation and the subsequent production of naphthalene, phenols and polymer resins are responsible for most of the soil contamination. Styrene, naphthalene, indene, and their methylated derivatives and dimers (most notably, naphthyl-methylnaphthalene) are particularly abundant and/or distinctive. It is remarkable that most of the contaminants were detected simply by pyrolysis-GC-MS, demonstrating its effectiveness for rapid environmental forensic screening of organic contamination. Commonly used environmental analytical approaches would likely have overlooked the predominant pollutants at this site. This could lead to serious shortcomings in remediation planning and implementation. The novel methodology presented herein appears practical and applicable to complexly-contaminated brownfield sites around the world

    Macrophage Gal/GalNAc lectin 2 (MGL2)+ peritoneal antigen presenting cells during Fasciola hepatica infection are essential for regulatory T cell induction

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    Fasciola hepatica, one of the agents that causes fasciolosis, modulates the host immune system to allow parasite survival in the host. F. hepatica expresses carbohydrate-containing glycoconjugates that are decoded by C-type lectin receptors, such as Dectin-1, mannose receptor, DC-SIGN and MGL, that are mainly present on myeloid antigen presenting cells (APCs) and can mediate immunoregulatory properties on T cells. In particular, Macrophage Gal/GalNAc lectin 2 (MGL2) expands modified Th2 immune responses, while suppressing Th1 polarization, upon recognition of GalNAc-glycosylated parasite components. In this study, by using MGL2-DTR transgenic mice that encode human diphtheria toxin receptor in MGL2+ cells, we demonstrate the role of peritoneal APCs during F. hepatica infection in favoring parasite survival. This process might be mediated by the induction of splenic Tregs in vivo, since the depletion of MGL2+ cells conferred mice with partial resistance to the infection and abrogated the increase of CD4+/CD25+ FoxP3+ Tregs induced by the parasite. Therefore, MGL2+ cells are critical determinants of F. hepatica infection and could constitute immune checkpoints to control parasite infection.Agencia Nacional de Investigación e InnovaciónPrograma de Desarrollo de las Ciencias Básica

    Heme-Oxygenase-1 Attenuates Oxidative Functions of Antigen Presenting Cells and Promotes Regulatory T Cell Differentiation during Fasciola hepatica Infection

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    Fasciola hepatica is a fluke that infects livestock and humans causing fasciolosis, a zoonotic disease of increasing importance due to its worldwide distribution and high economic losses. The parasite regulates the host immune system by inducing a strong Th2 and regulatory T (Treg) cell immune response through mechanisms that might involve the expression or activity of heme-oxygenase-1 (HO-1), the rate-limiting enzyme in the catabolism of free heme that also has immunoregulatory and antioxidant properties. In this paper, we show that F. hepatica-infected mice upregulate HO-1 on peritoneal antigen-presenting cells (APC), which produce decreased levels of both reactive oxygen and nitrogen species (ROS/RNS). The presence of these cells was associated with increased levels of regulatory T cells (Tregs). Blocking the IL-10 receptor (IL-10R) during parasite infection demonstrated that the presence of splenic Tregs and peritoneal APC expressing HO-1 were both dependent on IL-10 activity. Furthermore, IL-10R neutralization as well as pharmacological treatment with the HO-1 inhibitor SnPP protected mice from parasite infection and allowed peritoneal APC to produce significantly higher ROS/RNS levels than those detected in cells from infected control mice. Finally, parasite infection carried out in gp91phox knockout mice with inactive NADPH oxidase was associated with decreased levels of peritoneal HO-1+ cells and splenic Tregs, and partially protected mice from the hepatic damage induced by the parasite, revealing the complexity of the molecular mechanisms involving ROS production that participate in the complex pathology induced by this helminth. Altogether, these results contribute to the elucidation of the immunoregulatory and antioxidant role of HO-1 induced by F. hepatica in the host, providing alternative checkpoints that might control fasciolosis.Agencia Nacional de Investigación e InnovaciónPrograma de Desarrollo de las Ciencias Básica

    Novel incorporation of red-stage haematococcus pluvialis wet paste as a colourant and enhancer of the organoleptic and functional properties of filloas †

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    Haematococcus pluvialis Flotow is a microalga used as a nutraceutical, due to its high content in bioactive compounds, mainly carotenoids, in which astaxanthin stands out [1]. Furthermore, H. plu- vialis has shown a high antioxidant potential, and combined with its intense red colour, this microalga could have dual functionality: as a colourant and a bioactive ingredient [ 2]. The process to obtain this ingredient involves several transformation steps—namely, lyophilisation and saponification—raising the costs to develop and obtain free astaxanthin, which paradoxically presents greater instability and solubility than its esterified counterpart [ 3]. Thus, this study provides an alternative approach for the application of red, astaxanthin-rich, H. pluvialis wet paste as a partial substitute for wheat flour (7% and 13% w/w) in the preparation of filloas (Galician pancakes), a typical dessert from the northwestern region of the Iberian Peninsula. To evaluate its power as a natural pigment, the stability of colour over time (3, 6, and 9 days) was measured, and the results were compared with those of a commercial colourant. At the same time, its physicochemical properties such as the microbiological profile were measured to determine its functionality as a food preservative. As a result, redness stability (a*) of 8% higher than that of the commercial colourant was obtained for the maximum concentration of H. pluvialis analysed. The texture showed a significant response (p < 0.02), improving its properties as the concentration of the microalga increased, which showed a tenacity of 3.23 N and extensibility of 15.10 mm during the first 6 days, i.e., a 52% and 19% improvement, respectively, in relation to the control group. In turn, an enrichment of carotenoids, fatty acids, and phenolic com- pounds, in combination with a potential moderator of microbiological degradation by this unicellular organism, gives added value to this food matrix.This research was funded by project ED431 2020/06 (Galician Competitive Research Groups Xunta de Galicia). This study was supported by project EQC2018-005011-P (Ministry of Science, Innovation and Universities, Spain). All these programmes are co-funded by FEDER (EU). The authors are also grateful to Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES to CIMO (UIDB/00690/2020); to FCT for S. Heleno (CEECIND/03040/2017) and L. Barros contracts through the individual and institutional scientific employment programme contract, respectively. This article is based upon work from the Sample Preparation Study Group and Network, supported by the Division of Analytical Chemistry of the European Chemical Societyinfo:eu-repo/semantics/publishedVersio
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