2,750 research outputs found
Desafíos petroleros para América Latina y África ante la expansión asiática
La menor dependencia por parte de Estados Unidos de importaciones de crudo ha causado una reducción de los envíos desde América Latina y África. También Asia ha realizado esfuerzos por diversificar las fuentes de suministro para satisfacer su demanda energética y reducir así la exposición a Oriente Medio. Estos desarrollos tienen implicaciones para los proyectos dirigidos a aumentar la participación de América Latina y África en el mercado asiático. En este contexto, este artículo examina el significado de la expansión del financiamiento asiático apoyado en energía; identifica oportunidades de complementariedad entre regiones, y explora ejemplos vinculados al desarrollo de proyectos de petróleo en Venezuela y a la utilización de crudos africanos como insumo, así como el interés de empresas latinoamericanas por desarrollar proyectos en África
Induced Monolayer Altermagnetism in MnP(S,Se) and FeSe
Altermagnets (AM) are a recently discovered third class of collinear magnets,
distinctly different from conventional ferromagnets (FM) and antiferromagnets
(AF). AM have been actively researched in the last few years, but two aspects
so far remain unaddressed: (1) Are there realistic 2D single-layer
altermagnets? And (2) is it possible to functionalize a conventional AF into AM
by external stimuli? In this paper we address both issues by demonstrating how
a well-known 2D AF, MnP(S,Se) can be functionalized into strong AM by
applying out-of-plane electric field. Of particular interest is that the
induced altermagnetism is of a higher even-parity wave symmetry than expected
in 3D AM with similar crystal symmetries. We confirm our finding by
first-principles calculations of the electronic structure and magnetooptical
response. We also propose that recent observations of the time-reversal
symmetry breaking in the famous Fe-based superconducting chalchogenides, either
in monolayer form or in the surface layer, may be related not to an FM, as
previously assumed, but to the induced 2D AM order. Finally, we show that
monolayer FeSe can simultaneously exhibit unconventional altermagnetic
time-reversal symmetry breaking and quantized spin Hall conductivity indicating
possibility to research an intriquing interplay of 2D altermagnetism with
topological and superconducting states within a common crystal-potential
environment.Comment: 11 pages, 7 figure
Characterization of Microbial Shifts during the Production and Ripening of Raw Ewe Milk-Derived Idiazabal Cheese by High-Throughput Sequencing
first_page
settings
Open AccessArticle
Characterization of Microbial Shifts during the Production and Ripening of Raw Ewe Milk-Derived Idiazabal Cheese by High-Throughput Sequencing
by Gorka Santamarina-García
* [ORCID] , Igor Hernández
[ORCID] , Gustavo Amores
[ORCID] and Mailo Virto
* [ORCID]
Lactiker Research Group, Department of Biochemistry and Molecular Biology, Faculty of Pharmacy, University of the Basque Country (UPV/EHU), Paseo de la Universidad 7, 01006 Vitoria-Gasteiz, Spain
*
Authors to whom correspondence should be addressed.
Academic Editor: Huizhong Chen
Biology 2022, 11(5), 769; https://doi.org/10.3390/biology11050769
Received: 13 April 2022 / Revised: 5 May 2022 / Accepted: 11 May 2022 / Published: 18 May 2022
Download PDF Browse Figures
Citation Export
Simple Summary
Idiazabal is a traditional cheese produced from raw ewe milk in the Basque Country (Southwestern Europe). The sensory properties of raw milk cheeses have been attributed, among other factors, to microbial shifts that occur during the production and ripening processes. In this study, we used high-throughput sequencing technologies to investigate the microbiota of Latxa ewe raw milk and the dynamics during cheese production and ripening processes. The microbiota of raw milk was composed of lactic acid bacteria (LAB), environmental bacteria and non-desirable bacteria. Throughout the cheese making and ripening processes, the growth of LAB was promoted, whereas that of non-desirable and environmental bacteria was inhibited. Moreover, some genera not reported previously in raw ewe milk were detected and clear differences were observed in the bacterial composition of raw milk and cheese among producers, in relation to LAB and environmental or non-desirable bacteria, some of which could be attributed to the production of flavour related compounds.
Abstract
In this study, we used high-throughput sequencing technologies (sequencing of V3–V4 hypervariable regions of 16S rRNA gene) to investigate for the first time the microbiota of Latxa ewe raw milk and the bacterial shifts that occur during the production and ripening of Idiazabal cheese. Results revealed several bacterial genera not reported previously in raw ewe milk and cheese, such as Buttiauxella and Obesumbacterium. Both the cheese making and ripening processes had a significant impact on bacterial communities. Overall, the growth of lactic acid bacteria (LAB) (Lactococcus, Lactobacillus, Leuconostoc, Enterococcus, Streptococcus and Carnobacterium) was promoted, whereas that of non-desirable and environmental bacteria was inhibited (such as Pseudomonas and Clostridium). However, considerable differences were observed among producers. It is noteworthy that the starter LAB (Lactococcus) predominated up to 30 or 60 days of ripening and then, the growth of non-starter LAB (Lactobacillus, Leuconostoc, Enterococcus and Streptococcus) was promoted. Moreover, in some cases, bacteria related to the production of volatile compounds (such as Hafnia, Brevibacterium and Psychrobacter) also showed notable abundance during the first few weeks of ripening. Overall, the results of this study enhance our understanding of microbial shifts that occur during the production and ripening of a raw ewe milk-derived cheese (Idiazabal), and could indicate that the practices adopted by producers have a great impact on the microbiota and final quality of this cheese.This research was funded by the Basque Government, grant to Research Groups number IT944-16. G. Santamarina-García received a predoctoral grant from the University of the Basque Country (UPV/EHU)
Antibiotics in Dairy Production: Where Is the Problem?
Antibiotics have long been used for the prevention and treatment of common diseases and for prophylactic purposes in dairy animals. However, in recent decades it has become a matter of concern due to the widespread belief that there has been an abuse or misuse of these drugs in animals and that this misuse has led to the presence of residues in derived foods, such as milk and dairy products. Therefore, this review aims to compile the scientific literature published to date on the presence of antibiotic residues in these products worldwide. The focus is on the reasons that lead to their presence in food, on the potential problems caused by residues in the characteristics of dairy products and in their manufacturing process, on the development and spread of antibiotic-resistant bacteria, and on the effects that both residues and resistant bacteria can cause on human and environmental health.he research group was funded by The University of the Basque Country (UPV/EHU) (grant COLAB20/14) and by the Basque Government, grant to Research Groups number IT944-16. G. Santamarina-García received a predoctoral grant from the University of the Basque Country
Demystifying COVID-19 digital contact tracing: A survey on frameworks and mobile apps
The coronavirus pandemic is a new reality and it severely affects the modus
vivendi of the international community. In this context, governments are
rushing to devise or embrace novel surveillance mechanisms and monitoring
systems to fight the outbreak. The development of digital tracing apps, which
among others are aimed at automatising and globalising the prompt alerting of
individuals at risk in a privacy-preserving manner is a prominent example of
this ongoing effort. Very promptly, a number of digital contact tracing
architectures has been sprouted, followed by relevant app implementations
adopted by governments worldwide. Bluetooth, and specifically its Low Energy
(BLE) power-conserving variant has emerged as the most promising short-range
wireless network technology to implement the contact tracing service. This work
offers the first to our knowledge, full-fledged review of the most concrete
contact tracing architectures proposed so far in a global scale. This endeavour
does not only embrace the diverse types of architectures and systems, namely
centralised, decentralised, or hybrid, but it equally addresses the client
side, i.e., the apps that have been already deployed in Europe by each country.
There is also a full-spectrum adversary model section, which does not only
amalgamate the previous work in the topic, but also brings new insights and
angles to contemplate upon.Comment: 34 pages, 3 figure
Analysis of 222Rn Surface Concentrations in the Basque Country (Spain): A Case Study of Heat Waves
The objective of this study was to characterize radon concentrations registered in the Radiological Surveillance Network of the Basque country in relation to local meteorological parameters, and to determine its behaviour under heatwave events. For this purpose, radon measurements and meteorological parameters from June 2012 to June 2015 were analysed at two sites, Bilbao and Vitoria (northern Spain), in a region characterized by complex orography, causing large temporal and spatial variability in meteorological conditions. Yearly, seasonal, and diurnal cycle differences and similarities were investigated at both sites. The temporal evolution of radon concentration was analysed at both sites during the two heatwave periods officially identified by the State Meteorological Agency (8–11 August 2012 and 17–23 August 2012). The analysis revealed two different patterns of radon concentrations, in terms of both time and intensity, under this synoptic pattern, making it also possible to identify regional transport channels of radon concentrations between the two sites. This set of results evidences the adequate position of both stations to represent the spatial and temporal evolution of radiological variables continuously in this region
Relationship between the Dynamics of Gross Composition, Free Fatty Acids and Biogenic Amines, and Microbial Shifts during the Ripening of Raw Ewe Milk-Derived Idiazabal Cheese
This study reports for the first time the relationship between bacterial succession, characterized by high-throughput sequencing (sequencing of V3–V4 16S rRNA regions), and the evolution of gross composition, free fatty acids (FFAs) and biogenic amines (BAs) during cheese ripening. Specifically, Idiazabal PDO cheese, a raw ewe milk-derived semi-hard o hard cheese, was analysed. Altogether, 8 gross parameters were monitored (pH, dry matter, protein, fat, Ca, Mg, P and NaCl) and 21 FFAs and 8 BAs were detected. The ripening time influenced the concentration of most physico-chemical parameters, whereas the producer mainly affected the gross composition and FFAs. Through an O2PLS approach, the non-starter lactic acid bacteria Lactobacillus, Enterococcus and Streptococcus were reported as positively related to the evolution of gross composition and FFAs release, while only Lactobacillus was positively related to BAs production. Several environmental or non-desirable bacteria showed negative correlations, which could indicate the negative impact of gross composition on their growth, the antimicrobial effect of FFAs and/or the metabolic use of FFAs by these genera, and their ability to degrade BAs. Nonetheless, Obesumbacterium and Chromohalobacter were positively associated with the synthesis of FFAs and BAs, respectively. This research work provides novel information that may contribute to the understanding of possible functional relationships between bacterial communities and the evolution of several cheese quality and safety parameters.This research was funded by the Basque Government, grant number IT944-16. G. Santamarina-García received a predoctoral grant from the University of the Basque Country (UPV/EHU)
Ru-Catalyzed C-H Arylation of Fluoroarenes with Aryl Halides
We gratefully acknowledge the Engineering and Physical
Sciences Research Council (EPSRC, EP/I038578/1 and EP/
K039547/1) for funding and the European Research Council
for a Starting Grant (to I.L.).
- …