Today, we have been witnessing a steady tendency in the increase of global demand for maize, wheat, soybeans, and their products due to the steady growth and strengthening of the livestock industry. ...Thus, animal feed safety has gradually become more important, with mycotoxins representing one of the most significant hazards. Mycotoxins comprise different classes of secondary metabolites of molds. With regard to animal feed, aflatoxins, fumonisins, ochratoxins, trichothecenes, and zearalenone are the more prevalent ones. In this review, several constraints posed by these contaminants at economical and commercial levels will be discussed, along with the legislation established in the European Union to restrict mycotoxins levels in animal feed. In addition, the occurrence of legislated mycotoxins in raw materials and their by-products for the feeds of interest, as well as in the feeds, will be reviewed. Finally, an overview of the different sample pretreatment and detection techniques reported for mycotoxin analysis will be presented, the main weaknesses of current methods will be highlighted.
A new simple and reliable method combining an acetonitrile partitioning extractive procedure followed by dispersive solid-phase cleanup (QuEChERS) with dispersive liquid–liquid microextraction ...(DLLME) and further gas chromatography mass spectrometry analysis was developed for the simultaneous determination of bisphenol A (BPA) and bisphenol B (BPB) in canned seafood samples. Besides the great enrichment factor provided, the final DLLME extractive step was designed in order to allow the simultaneous acetylation of the compounds required for their gas chromatographic analysis. Tetrachloroethylene was used as extractive solvent, while the acetonitrile extract obtained from QuEChERS was used as dispersive solvent, and anhydride acetic as derivatizing reagent. The main factors influencing QuEChERS and DLLME efficiency including nature of QuEChERS dispersive-SPE sorbents, amount of DLLME extractive and dispersive solvents and nature and amount of derivatizing reagent were evaluated. DLLME procedure provides an effective enrichment of the extract, allowing the required sensitivity even using a single quadropole MS as detector. The optimized method showed to be accurate (>68 % recovery), reproducible (<21 % relative standard deviation) and sensitive for the target analytes (method detection limits of 0.2 μg/kg for BPA and 0.4 μg/kg for BPB). The screening of several canned seafood samples commercialized in Portugal (total = 47) revealed the presence of BPA in more than 83 % of the samples with levels ranging from 1.0 to 99.9 μg/kg, while BPB was found in only one sample at a level of 21.8 μg/kg.
This article provides a review about mycotoxins occurrence in cereals and cereal foodstuffs, and analytical methods proposed for their determination from 2008 to the present. Special attention was ...given to recent developments in sample preparation and chromatographic approaches for mycotoxins identification/quantification. Recent information on occurrence and determination of conjugated mycotoxins was also reviewed. For the first time a review is done about mycotoxins occurrence in cereals and derived products published in the last years, together with the recent improvements regarding methods for their quantification. This review gives a good insight about the progress that has been done in the last years and points the path to further research needed.
•Occurrence of mycotoxins in cereals and cereal products.•Analytical features of relevant papers published since 2008.•Critical evaluation of sample-preparation extraction techniques.•Critical evaluation of chromatographic methods.•Advances in analysis of conjugated mycotoxins.
For many chemical processes, high single-pass conversion of reactants into products reduces the need to separate products downstream. However, low-temperature carbon dioxide electrolyzers that ...maximize single-pass conversion suffer from low product concentration. Maximizing product concentration is therefore a more meaningful target for CO2 electrolyzers than maximizing single-pass conversion.The authors comment that maximizing product concentration is a more meaningful target for CO2 electrolyzers than maximizing single-pass conversion.
The combination of multiple observational probes has long been advocated as a powerful technique to constrain cosmological parameters, in particular dark energy. The Dark Energy Survey has measured ...207 spectroscopically confirmed type Ia supernova light curves, the baryon acoustic oscillation feature, weak gravitational lensing, and galaxy clustering. Here we present combined results from these probes, deriving constraints on the equation of state, w, of dark energy and its energy density in the Universe. Independently of other experiments, such as those that measure the cosmic microwave background, the probes from this single photometric survey rule out a Universe with no dark energy, finding w=-0.80_{-0.11}^{+0.09}. The geometry is shown to be consistent with a spatially flat Universe, and we obtain a constraint on the baryon density of Ω_{b}=0.069_{-0.012}^{+0.009} that is independent of early Universe measurements. These results demonstrate the potential power of large multiprobe photometric surveys and pave the way for order of magnitude advances in our constraints on properties of dark energy and cosmology over the next decade.
The development and application of evolutionary algorithms (EAs) and other metaheuristics for the optimisation of water resources systems has been an active research field for over two decades. ...Research to date has emphasized algorithmic improvements and individual applications in specific areas (e.g. model calibration, water distribution systems, groundwater management, river-basin planning and management, etc.). However, there has been limited synthesis between shared problem traits, common EA challenges, and needed advances across major applications. This paper clarifies the current status and future research directions for better solving key water resources problems using EAs. Advances in understanding fitness landscape properties and their effects on algorithm performance are critical. Future EA-based applications to real-world problems require a fundamental shift of focus towards improving problem formulations, understanding general theoretic frameworks for problem decompositions, major advances in EA computational efficiency, and most importantly aiding real decision-making in complex, uncertain application contexts.
ABSTRACT We search for excess γ-ray emission coincident with the positions of confirmed and candidate Milky Way satellite galaxies using six years of data from the Fermi Large Area Telescope (LAT). ...Our sample of 45 stellar systems includes 28 kinematically confirmed dark-matter-dominated dwarf spheroidal galaxies (dSphs) and 17 recently discovered systems that have photometric characteristics consistent with the population of known dSphs. For each of these targets, the relative predicted γ-ray flux due to dark matter annihilation is taken from kinematic analysis if available, and estimated from a distance-based scaling relation otherwise, assuming that the stellar systems are DM-dominated dSphs. LAT data coincident with four of the newly discovered targets show a slight preference (each 2 local) for γ-ray emission in excess of the background. However, the ensemble of derived γ-ray flux upper limits for individual targets is consistent with the expectation from analyzing random blank-sky regions, and a combined analysis of the population of stellar systems yields no globally significant excess (global significance ). Our analysis has increased sensitivity compared to the analysis of 15 confirmed dSphs by Ackermann et al. The observed constraints on the DM annihilation cross section are statistically consistent with the background expectation, improving by a factor of ∼2 for large DM masses ( and ) and weakening by a factor of ∼1.5 at lower masses relative to previously observed limits.
Diabetes has been recognized as a risk factor contributing to the incidence and progression of Parkinson's disease (PD). Although several hypotheses suggest a number of different mechanisms ...underlying the aggravation of PD caused by diabetes, less attention has been paid to the fact that diabetes and PD share pathological microvascular alterations in the brain. The characteristics of the interaction of diabetes in combination with PD at the vascular interface are currently not known.
We combined a high-fat diet (HFD) model of diabetes mellitus type 2 (DMT2) with the 6-OHDA lesion model of PD in male mice. We analyzed the association between insulin resistance and the achieved degree of dopaminergic nigrostriatal pathology. We further assessed the impact of the interaction of the two pathologies on motor deficits using a battery of behavioral tests and on microglial activation using immunohistochemistry. Vascular pathology was investigated histologically by analyzing vessel density and branching points, pericyte density, blood-brain barrier leakage, and the interaction between microvessels and microglia in the striatum.
Different degrees of PD lesion were obtained resulting in moderate and severe dopaminergic cell loss. Even though the HFD paradigm did not affect the degree of nigrostriatal lesion in the acute toxin-induced PD model used, we observed a partial aggravation of the motor performance of parkinsonian mice by the diet. Importantly, the combination of a moderate PD pathology and HFD resulted in a significant pericyte depletion, an absence of an angiogenic response, and a significant reduction in microglia/vascular interaction pointing to an aggravation of vascular pathology.
This study provides the first evidence for an interaction of DMT2 and PD at the brain microvasculature involving changes in the interaction of microglia with microvessels. These pathological changes may contribute to the pathological mechanisms underlying the accelerated progression of PD when associated with diabetes.
Key points
Fish oil (FO), rich in omega‐3 polyunsaturated fatty acids, has beneficial effects on changes induced by obesity and partially prevents associated comorbidities.
The effects of FO on ...adipocytes from different adipose tissue depots in high‐fat (HF) diet induced obese mice have not been uninvestigated.
This is the first study to examine the effects of FO on changes in metabolism and adipokine production in adipocytes from s.c. (inguinal; ING) or visceral (retroperitoneal; RP) white adipose depots in a HF diet‐induced obese mice.
Unlike most studies performed previously, FO supplementation was initiated 4 weeks before the induction of obesity.
HF diet caused marked changes in ING (glucose uptake and secretion of adiponectin, tumour necrosis factor‐α and interleukin‐6 in ING) and RP (lipolysis, de novo lipogenesis and secretion of pro‐inflammatory cytokines) adipose depots.
Previous and concomitant FO administration prevented the changes in ING and RP adipocytes induced by the HF diet.
In the present study, we investigated the effect of fish oil (FO) on metabolism and adipokine production by adipocytes from s.c. (inguinal; ING) and visceral (retroperitoneal; RP) white adipose depots in high‐fat (HF) diet‐induced obese mice. Mice were divided into CO (control diet), CO+FO, HF and HF+FO groups. The HF group presented higher body weight, glucose intolerance, insulin resistance, higher plasma total and low‐density lipoprotein cholesterol levels, and greater weights of ING and RP adipose depots accompanied by hypertrophy of the adipocytes. FO exerted anti‐obesogenic effects associated with beneficial effects on dyslipidaemia and insulin resistance in mice fed a HF diet (HF+FO group). HF raised RP adipocyte lipolysis and the production of pro‐inflammatory cytokines and reduced de novo synthesis of fatty acids, whereas, in ING adipocytes, it decreased glucose uptake and adiponectin secretion but did not change lipolysis. Therefore, the adipose depots play different roles in HF diet‐induced insulin resistance according to their location in the body. Concerning cytokine secretion, adipocytes per se in addition to white adopise tissue infiltrated leukocytes have to be considered in the aetiology of the comorbidities associated with obesity. Evidence is presented showing that previous and concomitant administration of FO can prevent changes in metabolism and the secretion of hormones and cytokines in ING and RP adipocytes induced by HF.
Key points
Fish oil (FO), rich in omega‐3 polyunsaturated fatty acids, has beneficial effects on changes induced by obesity and partially prevents associated comorbidities.
The effects of FO on adipocytes from different adipose tissue depots in high‐fat (HF) diet induced obese mice have not been uninvestigated.
This is the first study to examine the effects of FO on changes in metabolism and adipokine production in adipocytes from s.c. (inguinal; ING) or visceral (retroperitoneal; RP) white adipose depots in a HF diet‐induced obese mice.
Unlike most studies performed previously, FO supplementation was initiated 4 weeks before the induction of obesity.
HF diet caused marked changes in ING (glucose uptake and secretion of adiponectin, tumour necrosis factor‐α and interleukin‐6 in ING) and RP (lipolysis, de novo lipogenesis and secretion of pro‐inflammatory cytokines) adipose depots.
Previous and concomitant FO administration prevented the changes in ING and RP adipocytes induced by the HF diet.
Shrimp farms cause environmental impacts in coastal ecosystems, compromising water quality by discharging effluents rich in nutrients and organic matter. The impacts of shrimp farming are often ...investigated by the unit effect of a farm. In this study, a harvest time series generator is used to analyze the impact of the synergistic effect of several shrimp farm harvests in a tropical estuary. Two other scenarios with harvests concentrated during spring and neap tides were also analyzed, showing waste management techniques that can reduce the impact of shrimp aquaculture on coastal areas. A hydrodynamic circulation and water quality model were implemented to evaluate the dispersion of pollutants using different discharge combinations. The harvesting scenarios were compared to a scenario without the activity. Results indicate that shrimp farming is not the main anthropogenic source of pollution in the estuary studied. There were no significant differences in the average and maximum variations in nutrient and organic matter concentrations between the different management techniques.
PDF
