463 research outputs found
Effect of high-pressure processing of Atlantic mackerel (Scomber scombrus) on biochemical changes during commercial frozen storage
This research focuses on biochemical changes related to quality losses observed in Atlantic mackerel (Scomber scombrus) muscle stored under commercial frozen storage conditions (9 months, −18 °C) when subjected to highhydrostatic pressure (HHP) treatments (125, 150, 175, and 200 MPa for 0 min) before freezing. After freezing, free fatty acid (FFA) formation (lipid hydrolysis assessment) showed a marked inhibition in HHP-treated fish and during frozen storage of samples treated at 175 MPa. Fluorescence ratio (FR) assessment of tertiary lipid oxidation showed a partial inhibitory effect during the 0–9-month period for samples treated at 175 and 200 MPa. After a 3-month storage of samples treated at these pressure levels, one-dimensional SDS-PAGE analysis of the sarcoplasmic protein fraction revealed the disappearance of a band; additionally, samples treated at 150 MPa showed the same effect at month 9. After gel excision, trypsin
digestion, tandem mass spectrometry (MS/MS), and sequence database analysis, the band was identified as phosphoglycerate mutase 2 (28.7 kDa). On the other hand, HHP processing did not show a significant effect on trimethylamine (TMA) values, primary and secondary lipid oxidation, PUFA levels, 1-D myofibril protein pattern, and the activity of acid phosphatase and cathepsins B and D. Biochemical quality indices such as FFA, TMA, and FR and the activity of acid phosphatase and cathepsin B showed a progressive increase throughout the frozen storage of all samples
Lipid and protein changes related to quality loss in frozen sardine (Sardina pilchardus) previously processed under high-pressure conditions
This research focuses on biochemical changes related to quality loss in frozen (−18 °C for 9 months) sardine
(Sardina pilchardus) previously subjected to high-pressure (HP) processing (125–200 MPa). The inhibition (p < 0.05) of lipid hydrolysis development (lower free fatty acid formation and lipase activity), observed in frozen sardine as a result of the previous HP treatment, increased with the pressure level applied. Several parameters including peroxide value, thiobarbituric acid index, fluorescent compounds, and polyenes
showed that the applied HP conditions prior to sardine freezing did not increase lipid oxidation. Also, HP did not induce a substantial modification of acid phosphatase and cathepsins B and D activities, and the electrophoretic patterns of sarcoplasmic and myofibrillar protein fractions did not change. However, HP processing led to a decrease in myofibrillar protein content in frozen pressure-treated fish, an effect that was
higher in 175- and 200-MPa treated samples. In conclusion, this research showed that pressure treatments in the 125–200- MPa range with holding time of 0 min cause only minor modifications in biochemical indicators of deterioration throughout the subsequent frozen storage of samples for up to 9 months. This study shows the need to optimize HP conditions, particularly in the case of applications combining HP treatments, frozen storage, and thawing to obtain products with high quality and commercial viability
De semillas a bioenergía: un camino de conversión para la valorización de semillas de ricino y jatrofa
The world’s energy matrix can be diversified with biodiesel from castor and jatropha oil. Hence, the objective of this study was to assess a conversion path for the valorization of castor and jatropha seeds. The results showed the maximum extraction of castor oil at 90 °C, 2 rpm, and 6 mm nozzle, achieving a yield of 36.97% and for jatropha oil at 100 °C, 1.5 rpm, and 10 mm nozzle, achieving a yield of 20.11%. The acid value and cloud point of castor and jatropha oil were 0.797 and 23.44 mg KOH/g, 10±1 °C and 12±0.55 °C, respectively; while the pour point was -3 °C for both. The acid value and cloud point for biodiesels ranged from 0.26-0.43 mg KOH/g, and -12.50-6.10 °C, respectively. The viscosity of oils and biodiesel ranged from 0.02-1.3 P. GC-MS indicated 66.38% of methyl ricinoleate in castor biodiesel and 31.64% of methyl oleate in jatropha biodiesel. The HHV for castor and jatropha biodiesel ranged from 32.37-40.25 MJ/kg.La matriz energética mundial puede diversificarse con biodiesel de ricino y de jatrofa. Por lo tanto, el objetivo de este trabajo fue evaluar la ruta de conversión de las semillas de ricino y jatrofa. Los resultados mostraron que la máxima extracción de aceite de ricino se dio a 90 °C, 2 rpm, y boquilla de 6 mm, alcanzando un rendimiento de 36,97% y para el aceite de jatrofa fue a 100 °C, 1,5 rpm, y boquilla de 10 mm, obteniendo un rendimiento de 20,11%. El índice de acidez y punto de nube del aceite de ricino y jatrofa fue de 0,797 y 23,44 mg de KOH/g, 10 ± 1 °C y 12 ± 0,55 °C, respectivamente, mientras que el punto de fluidez fue de -3 °C para ambos. El índice de acidez y el punto de nube del biodiésel de ricino y jatropha fueron 0,43 y 0,26 mg KOH/g, -12,50 °C y 6,10 °C, respectivamente. La viscosidad dinámica de los aceites y el biodiesel osciló entre 0,02 y 1,3 P. El análisis GC-MS indicó 66,38% de ricinoleato de metilo en biodiesel de higuerilla y 31,64% de oleato de metilo en biodiesel de jatrofa. El HHV para el biodiésel de ricino y jatrofa osciló entre 32,37 y 40,25 MJ/kg
Determinants of the current and future distribution of the West Nile virus mosquito vector Culex pipiens in Spain
Changes in environmental conditions, whether related or not to human activities, are continuously modifying the geographic distribution of vectors, which in turn affects the dynamics and distribution of vector-borne infectious diseases. Determining the main ecological drivers of vector distribution and how predicted changes in these drivers may alter their future distributions is therefore of major importance. However, the drivers of vector populations are largely specific to each vector species and region. Here, we identify the most important human-activity-related and bioclimatic predictors affecting the current distribution and habitat suitability of the mosquito Culex pipiens and potential future changes in its distribution in Spain. We determined the niche of occurrence (NOO) of the species, which considers only those areas lying within the range of suitable environmental conditions using presence data. Although almost ubiquitous, the distribution of Cx. pipiens is mostly explained by elevation and the degree of urbanization but also, to a lesser extent, by mean temperatures during the wettest season and temperature seasonality. The combination of these predictors highlights the existence of a heterogeneous pattern of habitat suitability, with most suitable areas located in the southern and northeastern coastal areas of Spain, and unsuitable areas located at higher altitude and in colder regions. Future climatic predictions indicate a net decrease in distribution of up to 29.55%, probably due to warming and greater temperature oscillations. Despite these predicted changes in vector distribution, their effects on the incidence of infectious diseases are, however, difficult to forecast since different processes such as local adaptation to temperature, vector-pathogen interactions, and human-derived changes in landscape may play important roles in shaping the future dynamics of pathogen transmission.info:eu-repo/semantics/acceptedVersio
Response to Novel Drugs before and after Allogeneic Stem Cell Transplantation in Patients with Relapsed Multiple Myeloma
Multiple myeloma (MM) remains as an incurable disease and, although allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative approach, most patients ultimately relapse, and their treatment remains challenging. Because allo-HSCT can modify not only the biology of the disease, but also the immune system and the microenvironment, it can potentially enhance the response to rescue therapies. Information on the efficacy and safety of novel drugs in patients relapsing after allo-HSCT is lacking, however. The objectives of this study were to evaluate the efficacy and toxicity of rescue therapies in patients with MM who relapsed after allo-HSCT, as well as to compare their efficacy before and after allo-HSCT. This retrospective multicenter study included 126 consecutive patients with MM who underwent allo-HSCT between 2000 and 2013 at 8 Spanish centers. All patients engrafted. The incidence of grade II-IV acute graft-versus-host disease (GVHD) was 47%, and nonrelapse mortality within the first 100 days post-transplantation was 13%. After a median follow-up of 92 months, overall survival (OS) was 51% at 2 years and 43% at 5 years. The median progression-free survival after allo-HSCT was 7 months, whereas the median OS after relapse was 33 months. Patients relapsing in the first 6 months after transplantation had a dismal prognosis compared with those who relapsed later (median OS, 11 months versus 120 months; P <.001). The absence of chronic GVHD was associated with reduced OS after relapse (hazard ratio, 3.44; P <.001). Most patients responded to rescue therapies, including proteasome inhibitors (PIs; 62%) and immunomodulatory drugs (IMiDs; 77%), with a good toxicity profile. An in-depth evaluation, including the type and intensity of PI- and IMiD-based combinations used before and after allo-HSCT, showed that the overall response rate and duration of response after allo-HSCT were similar to those seen in the pretransplantation period. Patients with MM who relapse after allo-HSCT should be considered candidates for therapy with new drugs, which can achieve similar response rates with similar durability as seen in the pretransplantation period. This pattern does not follow the usual course of the disease outside the transplantation setting, where response rates and time to progression decreases with each consecutive line of treatment
Associations Between the Modified Food Standard Agency Nutrient Profiling System Dietary Index and Cardiovascular Risk Factors in an Elderly Population
Background: Helping consumers to improve the nutritional quality of their diet is a key public health action to prevent cardiovascular diseases (CVDs). The modified version of the Food Standard Agency Nutrient Profiling System Dietary Index (FSAm-NPS DI) underpinning the Nutri-Score front-of-pack label has been used in public health strategies to address the deleterious consequences of poor diets. This study aimed to assess the association between the FSAm-NPS DI and some CVD risk factors including body mass index (BMI), waist circumference, plasma glucose levels, triglyceride levels, high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol, and diastolic and systolic blood pressure. Materials and Methods: Dietary intake was assessed at baseline and after 1 year of follow-up using a 143-item validated semi-quantitative food-frequency questionnaire. Dietary indices based on FSAm-NPS applied at an individual level were computed to characterize the diet quality of 5,921 participants aged 55-75 years with overweight/obesity and metabolic syndrome from the PREDIMED-plus cohort. Associations between the FSAm-NPS DI and CVD risk factors were assessed using linear regression models. Results: Compared to participants with a higher nutritional quality of diet (measured by a lower FSAm-NPS DI at baseline or a decrease in FSAm-NPS DI after 1 year), those participants with a lower nutritional quality of diet (higher FSAm-NPS DI or an increase in score) showed a significant increase in the levels of plasma glucose, triglycerides, diastolic blood pressure, BMI, and waist circumference (beta coefficient [95% confidence interval]; P for trend) (1.67 [0.43, 2.90]; <0.001; 6.27 [2.46, 10.09]; <0.001; 0.56 [0.08, 1.05]; 0.001; 0.51 [0.41, 0.60]; <0.001; 1.19 [0.89, 1.50]; <0.001, respectively). No significant associations in relation to changes in HDL and LDL-cholesterol nor with systolic blood pressure were shown. Conclusion: This prospective cohort study suggests that the consumption of food items with a higher FSAm-NPS DI is associated with increased levels of several major risk factors for CVD including adiposity, fasting plasma glucose, triglycerides, and diastolic blood pressure. However, results must be cautiously interpreted because no significant prospective associations were identified for critical CVD risk factors, such as HDL and LDL-cholesterol, and systolic blood pressure
Evidence for a mixed mass composition at the `ankle' in the cosmic-ray spectrum
We report a first measurement for ultra-high energy cosmic rays of the
correlation between the depth of shower maximum and the signal in the water
Cherenkov stations of air-showers registered simultaneously by the fluorescence
and the surface detectors of the Pierre Auger Observatory. Such a correlation
measurement is a unique feature of a hybrid air-shower observatory with
sensitivity to both the electromagnetic and muonic components. It allows an
accurate determination of the spread of primary masses in the cosmic-ray flux.
Up till now, constraints on the spread of primary masses have been dominated by
systematic uncertainties. The present correlation measurement is not affected
by systematics in the measurement of the depth of shower maximum or the signal
in the water Cherenkov stations. The analysis relies on general characteristics
of air showers and is thus robust also with respect to uncertainties in
hadronic event generators. The observed correlation in the energy range around
the `ankle' at differs significantly from
expectations for pure primary cosmic-ray compositions. A light composition made
up of proton and helium only is equally inconsistent with observations. The
data are explained well by a mixed composition including nuclei with mass . Scenarios such as the proton dip model, with almost pure compositions, are
thus disfavoured as the sole explanation of the ultrahigh-energy cosmic-ray
flux at Earth.Comment: Published version. Added journal reference and DOI. Added Report
Numbe
Atmospheric effects on extensive air showers observed with the Surface Detector of the Pierre Auger Observatory
Atmospheric parameters, such as pressure (P), temperature (T) and density,
affect the development of extensive air showers initiated by energetic cosmic
rays. We have studied the impact of atmospheric variations on extensive air
showers by means of the surface detector of the Pierre Auger Observatory. The
rate of events shows a ~10% seasonal modulation and ~2% diurnal one. We find
that the observed behaviour is explained by a model including the effects
associated with the variations of pressure and density. The former affects the
longitudinal development of air showers while the latter influences the Moliere
radius and hence the lateral distribution of the shower particles. The model is
validated with full simulations of extensive air showers using atmospheric
profiles measured at the site of the Pierre Auger Observatory.Comment: 24 pages, 9 figures, accepted for publication in Astroparticle
Physic
The Fluorescence Detector of the Pierre Auger Observatory
The Pierre Auger Observatory is a hybrid detector for ultra-high energy
cosmic rays. It combines a surface array to measure secondary particles at
ground level together with a fluorescence detector to measure the development
of air showers in the atmosphere above the array. The fluorescence detector
comprises 24 large telescopes specialized for measuring the nitrogen
fluorescence caused by charged particles of cosmic ray air showers. In this
paper we describe the components of the fluorescence detector including its
optical system, the design of the camera, the electronics, and the systems for
relative and absolute calibration. We also discuss the operation and the
monitoring of the detector. Finally, we evaluate the detector performance and
precision of shower reconstructions.Comment: 53 pages. Submitted to Nuclear Instruments and Methods in Physics
Research Section
flavour tagging using charm decays at the LHCb experiment
An algorithm is described for tagging the flavour content at production of
neutral mesons in the LHCb experiment. The algorithm exploits the
correlation of the flavour of a meson with the charge of a reconstructed
secondary charm hadron from the decay of the other hadron produced in the
proton-proton collision. Charm hadron candidates are identified in a number of
fully or partially reconstructed Cabibbo-favoured decay modes. The algorithm is
calibrated on the self-tagged decay modes and using of data collected by the LHCb
experiment at centre-of-mass energies of and
. Its tagging power on these samples of
decays is .Comment: All figures and tables, along with any supplementary material and
additional information, are available at
http://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-027.htm
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