430 research outputs found
Occurrence of pesticide residues in Spanish honey measured by QuEChERS method followed by liquid and gas chromatography–Tandem mass spectrometry
In the current study, the QuEChERS extraction method with slight modifications, followed by liquid and gas chromatography–tandem mass spectrometry, was applied for the determination of 399 pesticide residues in 91 raw honey samples from northeastern Spain. The quality control proce-dure established in Document No. SANTE/12682/2019 was successfully followed: the responses in reagent blank and blank honey samples were below 30% of the reporting limit (0.01 mg kg-1) for all analysed compounds, the correlation coefficients (R2) were higher than 0.99 in most calibration curves, the deviation of back-calculated concentration from the true concentration was below ±20% (using the standard of 50 µg L-1 concentration), and the recoveries of spiked samples on matrix were within the range of 70–120% for almost all analytes. Only chlorfenvinphos (2–7.8 ng/g) and coumaphos (8.8–37 ng/g) were detected in 13 samples, and neither were observed to exceed their maximum residue limits (MRLs). Dietary risk assessment for pesticide residues in honey above their lowest calibrated level (LCL) was performed, and two different age groups, adults and infants, were considered as populations at risk. The contribution of honey lay far below the acceptable daily intake (ADI) for both pesticide residues. Therefore, according to our results, honey is unlikely to pose concerns for consumer health in terms of its contribution to dietary long-term exposure. However, to maintain the level of compliance, pesticide residues in honey should be continuously monitored. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
Esto es una sonata: la intermedialidad musical en la novela y en sus paratextos fuertes
This paper aims to explain the role that paratexts play in novels –and literary works in general– that imitate or reproduce musical patterns, supporting the thesis that they are often decisive for generating a musical reading of a text. A body of works from Spanish and Latin American fiction seldom explored from this perspective and the conceptual frame developed by Wolf or Petermann constitute the basis for an explanation of the various meanings that titles may acquire. Special attention is paid to the issue of how to understand generic titles as “sonata”, “symphony” or “fugue” when they point out to a musical dimension that is otherwise difficult to justify. Also, it is proposed a distinction between paratexts with a weak or a strong deontic power, as well as the idea that without some kind of thematisation, there is not musical imitation.Este artĂculo propone una explicaciĂłn del papel de los paratextos en las novelas que imitan o reproducen patrones musicales, defendiendo la tesis de que a menudo son clave para generar una dimensiĂłn musical en la obra. Recurriendo a un corpus español e hispanoamericano rara vez estudiado desde esta perspectiva, se aplica el marco conceptual que autores como Wolf o Petermann han desarrollado en el ámbito de los estudios intermediales para explicar los distintos sentidos que pueden adquirir los tĂtulos remáticos musicales, y se presta especial atenciĂłn a un problema habitualmente relegado: cĂłmo interpretar estos tĂtulos cuando apuntan a una condiciĂłn musical que difĂcilmente halla justificaciĂłn en el texto. Asimismo, esta argumentaciĂłn conduce a proponer una distinciĂłn entre paratextos con poder deĂłntico fuerte y dĂ©bil, y a defender la idea de que sin tematizaciĂłn, no hay imitaciĂłn musical
Production of the Superconducting Matching Quadrupoles for the LHC Insertions
The LHC insertions are equipped with individually powered superconducting quadrupole assemblies comprising several quadrupole magnets and orbit correctors, and range in length from 5.3Ă‚Â m to 11.3Ă‚Â m. Following the initial experience in the assembly of the pre-series cold masses, the production has advanced well and about half of the total of 82 units has been produced at CERN. In this paper we present the experience gained in steering the cold mass production, in particular with respect to the alignment requirements. We also report on the field quality and other measurements made for assuring the quality of the quadrupoles
Proton Collimation in TeV Colliders
In high intensity proton colliders with superconducting magnets, quenches induced by beam losses are unavoidable in the absence of a collimation system. We will show that a single stage system cannot suffice at TeV energies. We will discuss a two-stage collimation system at first as an optical system then considering true scattering in collimator jaws. Expected performance at LHC are presented. then finally, we present the preliminary measurements done at 120 GeV/c in the SPS ring with a simplified three stage collimation system
Proper 2–equivalences between infinite ended finitely presented groups
Recall that two finitely presented groups G and H are “proper 2–equivalent” if
they can be realized by finite 2–dimensional CW–complexes whose universal covers
are proper 2–equivalent as (strongly) locally finite CW–complexes. This purely
topological relation is coarser than the quasi-isometry relation, and those groups
which are 1–ended and semistable at infinity are classified, up to proper 2–equivalence,
by their fundamental pro-group. We show that if G and H are proper 2–equivalent
and semistable at each end, then any two finite graph of groups decompositions of G
and H with finite edge groups and finitely presented vertex groups with at most one
end must have the same set of proper 2–equivalence classes of (infinite) nonsimply
connected at infinity vertex groups (without multiplicities). Moreover, those simply
connected at infinity vertex groups in such a decomposition (if any) are all proper
2–equivalent to Z Z Z. Thus, under the semistability hypothesis, this answers
a question concerning the classification of infinite ended finitely presented groups
up to proper 2–equivalence, and shows again the behavior of proper 2–equivalences
versus quasi-isometries, in which the geometry of the group is taken into account
Prevalence of depression during the COVID-19 outbreak: A meta-analysis of community-based studies
Introduction: COVID-19 pandemic, declared on March 11, 2020, constitute an extraordinary health, social and economic global challenge. The impact on people''s mental health is expected to be high. This paper sought to systematically review community-based studies on depression conducted during the COVID-19 and estimate the pooled prevalence of depression.
Method: We searched for cross-sectional, community-based studies listed on PubMed or Web of Science from January 1, 2020 to May 8, 2020 that reported prevalence of depression. A random effect model was used to estimate the pooled proportion of depression.
Results: A total of 12 studies were included in the meta-analysis, with prevalence rates of depression ranging from 7.45% to 48.30%. The pooled prevalence of depression was 25% (95% CI: 18% - 33%), with significant heterogeneity between studies (I2 = 99.60%, p < .001).
Conclusions: Compared with a global estimated prevalence of depression of 3.44% in 2017, our pooled prevalence of 25% appears to be 7 times higher, thus suggesting an important impact of the COVID-19 outbreak on people's mental health. Addressing mental health during and after this global health crisis should be placed into the international and national public health agenda to improve citizens’ wellbeing
The Construction of the Superconducting Matching Quadrupoles for the LHC Insertions
After several years of effort, the construction of the superconducting matching quadrupoles for the LHC insertions is nearing completion. We retrace the main events of the project from the initial development of the quadrupole magnets of several types to the series production of over 100 complex superconducting magnets, and report on the techniques developed for steering of the production. The main performance parameters for the full series, such as quench training, field quality and magnet geometry are presented. The experience gained in the production of these special superconducting magnets is of considerable value for further development of the LHC insertions
Presence of Clostridium difficile in pig faecal samples and wild animal species associated with pig farms
Aims: to determine the presence of Clostridium difficile on fattening pig farms in north-eastern Spain. Methods and results: Twenty-seven farms were sampled. Pools of pig faecal samples (n = 210), samples of intestinal content from common farm pest species (n = 95) and environment-related samples (n = 93) were collected. Isolates were tested for toxin genes of C. difficile, and typed by PCR-ribotyping and toxinotyping. The minimal inhibitory concentrations of six antimicrobial agents were determined using Etest. Thirty-four isolates were obtained from 12 farms, and 30 (88·2%) had toxin genes. Seven ribotypes were identified. Ribotype 078 and its variant 126 were predominant (52·9%). The same ribotypes were isolated from different animal species on the same farm. None of the isolates were resistant to metronidazole or vancomycin. Conclusions: Clostridium difficile was common within the pig farm environment. Most of the positive samples came from pest species or were pest-related environmental samples. Significance and Impact of the Study: Pest species were colonized with toxigenic and antimicrobial-resistant C. difficile strains of the same ribotypes that are found in humans and pigs. Rodents and pigeons may transmit toxigenic and antimicrobial-resistant C. difficile strains that are of the same ribotypes as those occuring in humans
A topological equivalence relation for finitely presented groups
In this paper, we consider an equivalence relation within the class of
finitely presented discrete groups attending to their asymptotic topology
rather than their asymptotic geometry. More precisely, we say that two finitely
presented groups and are "proper -equivalent" if there exist
(equivalently, for all) finite -dimensional CW-complexes and , with
and , so that their universal covers
and are proper -equivalent. It follows that
this relation is coarser than the quasi-isometry relation. We point out that
finitely presented groups which are -ended and semistable at infinity are
classified, up to proper -equivalence, by their fundamental pro-group, and
we study the behaviour of this relation with respect to some of the main
constructions in combinatorial group theory. A (finer) similar equivalence
relation may also be considered for groups of type , which
captures more of the large-scale topology of the group. Finally, we pay special
attention to the class of those groups which admit a finite -dimensional
CW-complex with and whose universal cover
has the proper homotopy type of a -manifold. We show that if
such a group is -ended and semistable at infinity then it is proper
-equivalent to either ,
or (here,
is the free group on two generators). As it turns out, this
applies in particular to any group fitting as the middle term of a short
exact sequence of infinite finitely presented groups, thus classifying such
group extensions up to proper -equivalence
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