633 research outputs found

    Análisis sobre aspectos logísticos en el comercio electrónico español: plazos, costes, y modalidades de envíos y devoluciones

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    El surgimiento de Internet ha supuesto una transformación en todos los aspectos de la vida. De esta manera, ha conseguido revolucionar el comercio de forma que en la actualidad es posible realizar una compra y que el producto llegue a manos del consumidor sin necesidad de moverse del domicilio. En este trabajo se estudiará la importancia que tiene sobre el comercio electrónico la parte de la logística que se encarga de hacer llegar los productos. Se realizará un estudio empírico sobre una muestra de 80 empresas, en el que se analizarán las cinco principales variables (costes, plazos, tipos de envíos, métodos de pago y devoluciones) que condicionan la logística externa.Universidad de Sevilla. Grado en Administración y Dirección de Empresa

    Exploring Impact of Rare Variation in Systemic Lupus Erythematosus by a Genome Wide Imputation Approach

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    The importance of low frequency and rare variation in complex disease genetics is difficult to estimate in patient populations. Genome-wide association studies are therefore, underpowered to detect rare variation. We have used a combined approach of genome-wide-based imputation with a highly stringent sequence kernel association (SKAT) test and a case-control burden test. We identified 98 candidate genes containing rare variation that in aggregate show association with SLE many of which have recognized immunological function, but also function and expression related to relevant tissues such as the joints, skin, blood or central nervous system. In addition we also find that there is a significant enrichment of genes annotated for disease-causingmutations in the OMIM database, suggesting that in complex diseases such as SLE, such mutations may be involved in subtle or combined phenotypes or could accelerate specific organ abnormalities found in the disease. We here provide an important resource of candidate genes for SLE

    Multiple Genome Sequences of Lactobacillus pentosus Strains Isolated from Biofilms on the Skin of Fermented Green Table Olives

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    The draft genome sequences of five Lactobacillus pentosus strains isolated from biofilms on the skin of green table olives are presented here. These genome sequences will assist in revealing the potential probiotic properties of these strains, as the intake of fermented olives implicates the passage of millions of Lactobacillus spp. throughout a consumer’s gastrointestinal tract.This work was funded by the Junta de Andalucía through the P11-AGR-7051 project and by the Spanish Government through MICIIN projects AGL2013-48300-R/ALI (OliFilm project: www.olifilm.science.com.es) and BFU2016-77297-P

    Gut Microbiota of Great Spotted Cuckoo Nestlings is a Mixture of Those of Their Foster Magpie Siblings and of Cuckoo Adults

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    Diet and host genetic or evolutionary history are considered the two main factors determining gut microbiota of animals, although studies are scarce in natural populations. The system of great spotted cuckoos (Clamator glandarius) parasitizing magpies (Pica pica) is ideal to study both effects since magpie adults feed cuckoo and magpie nestlings with the same diet and, consequently, differences in gut microbiota of nestlings of these two species will mainly reflect the importance of genetic components. Moreover, the diet of adults and of nestling cuckoos drastically differ from each other and, thus, differences and similarities in their microbiotas would respectively reflect the effect of environmental and genetic factors. We used next-generation sequencing technologies to analyze the gut microbiota of cuckoo adults and nestlings and of magpie nestlings. The highest -diversity estimates appeared in nestling cuckoos and the lowest in nestling magpies. Moreover, despite the greatest differences in the microbiome composition of magpies and cuckoos of both ages, cuckoo nestlings harbored a mixture of the Operational Taxonomic Units (OTUs) present in adult cuckoos and nestling magpies. We identified the bacterial taxa responsible for such results. These results suggest important phylogenetic components determining gut microbiome of nestlings, and that diet might be responsible for similarities between gut microbiome of cuckoo and magpie nestlings that allow cuckoos to digest food provided by magpie adults.This work was supported by the Ministerio de Ciencia, Innovacion y Universidades and European (FEDER) funds (CGL2017-83103-P)

    Special structures of hoopoe eggshells enhance the adhesion of symbionts-carrying uropygial secretion to prevent embryo infection

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    This is the pre-peer-reviewed version of the following article: Martín-Vivaldi, M.; et al. Special structures of hoopoe eggshells enhance the adhesion of symbionts-carrying uropygial secretion to prevent embryo infection. Journal of Animal Ecology, (2014). which has been published in final form at: http://onlinelibrary.wiley.com/doi/10.1111/1365-2656.12243/abstract1. Animals live in a bacterial world, and detecting and exploring adaptations favouring mutualistic relationships with antibiotic-producing bacteria as a strategy to fight pathogens are of prime importance for evolutionary ecologists. 2. Uropygial secretion of European hoopoes (Upupa epops, Linnaeus) contains antimicrobials from mutualistic bacteria that may be used to prevent embryo infection. Here, we investigated the microscopic structure of hoopoe eggshells looking for special features favouring the adhesion of antimicrobial uropygial secretions. 3. We impeded female access to the uropygial gland and compared microscopic characteristics of eggshells, bacterial loads of eggs and of uropygial secretion, and hatching success of experimental and control females. Then, we explored the link between microbiological characteristics of uropygial secretion and these of eggs of hoopoes, as well as possible fitness benefits. 4. The microscopic study revealed special structures in hoopoes' eggshells (crypts). The experimental prevention of females' gland access demonstrated that crypts are filled with uropygial secretion and that symbiotic enterococci bacteria on the eggshells come, at least partially, from those in the female's uropygial gland. Moreover, the experiment resulted in a higher permeability of eggshells by several groups of bacteria and in elimination of the positive relationships detected for control nests between hatching success and density of symbiotic bacteria, either in the uropygial secretion of females or on the eggshell. 5. The findings of specialized crypts on the eggshells of hoopoes, and of video-recorded females smearing secretion containing symbiotic bacteria at a high density onto the eggshells strongly support a link between secretion and bacteria on eggs. Moreover, the detected associations between bacteria and hatching success suggest that crypts enhancing the adhesion of symbiont-carrying uropygial secretion likely protect embryos against infections.Support by funding was provided by Spanish Ministerio de Ciencia e Innovación, European funds (FEDER) (CGL2009-14006, CGL2010-19233-C03-01 and CGL2010-19233-C03-03) and Junta de Andalucía (P09-RNM-4557)

    LAB Bacteriocins Controlling the Food Isolated (Drug-Resistant) Staphylococci

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    Staphylococci are a group of microorganisms that can be often found in processed food and theymight pose a risk for human health. In this study we have determined the content of staphylococci in 7 different fresh goat-milk cheeses. These bacteria were present in all of them, ranging from 103 to 106 CFU/g based on growth on selective media. Thus, a set of 97 colonies was randomly picked for phenotypic and genotypic identification. They could be clustered by RAPD-PCR in 10 genotypes, which were assigned by 16S rDNA sequencing to four Staphylococcus species: Staphylococcus aureus, Staphylococcus chromogenes, S. simulans, and S. xylosus. Representative strains of these species (n = 25) were tested for antibiotic sensitivity, and 11 of them were resistant to at least one of the antibiotics tested, including erythromycin, amoxicillin-clavulanic acid and oxacillin. We also tested two bacteriocins produced by lactic acid bacteria (LAB), namely the circular bacteriocin AS-48 and the lantibiotic nisin. These peptides have different mechanism of action at the membrane level. Nevertheless, both were able to inhibit staphylococci growth at low concentrations ranging between 0.16–0.73μM for AS-48 and 0.02–0.23μM for nisin, including the strains that displayed antibiotic resistance. The combined effect of these bacteriocins were tested and the fractional inhibitory concentration index (FICI) was calculated. Remarkably, upon combination, they were active at the low micromolar range with a significant reduction of the minimal inhibitory concentration. Our data confirms synergistic effect, either total or partial, between AS-48 and nisin for the control of staphylococci and including antibiotic resistant strains. Collectively, these results indicate that the combined use of AS-48 and nisin could help controlling (pathogenic) staphylococci in food processing and preventing antibiotic-resistant strains reaching the consumer in the final products.This research was funded by the Spanish Ministry of Economy and Competitiveness (SAF2013-48971-C2-1-R project), including funds from the European Regional Development Fundings (ERDF) and the Research Group General (BIO160, UGR

    Seasonal and Sexual Differences in the Microbiota of the Hoopoe Uropygial Secretion

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    The uropygial gland of hoopoe nestlings and nesting females hosts bacterial symbionts that cause changes in the characteristics of its secretion, including an increase of its antimicrobial activity. These changes occur only in nesting individuals during the breeding season, possibly associated with the high infection risk experienced during the stay in the hole-nests. However, the knowledge on hoopoes uropygial gland microbial community dynamics is quite limited and based so far on culture-dependent and molecular fingerprinting studies. In this work, we sampled wild and captive hoopoes of different sex, age, and reproductive status, and studied their microbiota using quantitative polymerase chain reaction (qPCR), fluorescence in situ hybridization (FISH) and pyrosequencing. Surprisingly, we found a complex bacterial community in all individuals (including non-nesting ones) during the breeding season. Nevertheless, dark secretions from nesting hoopoes harbored significantly higher bacterial density than white secretions from breeding males and both sexes in winter. We hypothesize that bacterial proliferation may be host-regulated in phases of high infection risk (i.e., nesting). We also highlight the importance of specific antimicrobial-producing bacteria present only in dark secretions that may be key in this defensive symbiosis. Finally, we discuss the possible role of environmental conditions in shaping the uropygial microbiota, based on differences found between wild and captive hoopoes.This work was supported by the Spanish Ministry of Economy and Competitiveness and European (FEDER) funds (CGL2013-48193-C3-1-P/BOS, CGL2013-48193-C3-2-P/BOS, CGL2017-83103-P), and the Junta de Andalucía (RNM 339, RNM 340). S. M. Rodríguez-Ruano received a grant from the Spanish Ministry of Science and Innovation (FPI program)

    Circular and L50-like leaderless enterocins share a common ABC-transporter immunity gene

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    Microbes live within complex communities of interacting populations, either free-living in waters and soils or symbionts of animals and plants. Their interactions include the production of antimicrobial peptides (bacteriocins) to antagonize competitors, and these producers must carry their own immunity gene for self-protection. Whether other coexisting populations are sensitive or resistant to the bacteriocin producer will be key for the population dynamics within the microbial community. The immunity gene frequently consists of an ABC transporter to repel its own bacteriocin but rarely protects against a nonrelated bacteriocin. A case where this cross-resistance occurs mediated by a shared ABC transporter has been shown between enterocins MR10A/B and AS-48. The first is an L50-like leaderless enterocin, while AS-48 is a circular enterocin. In addition, L50-like enterocins such as MR10A/B have been found in E. faecalis and E. faecium, but AS-48 appears only in E. faecalis. Thus, using the ABC transporter of the enterocin MR10A/B gene cluster of Enterococcus faecalis MRR10-3 as a cross-resistance model, we aimed to unravel to what extent a particular ABC transporter can be shared across multiple bacteriocinogenic bacterial populations. To this end, we screened the MR10A/B-ABC transporters in available microbial genomes and analyzed their sequence homologies and distribution. Overall, our main findings are as follows: (i) the MR10A/B-ABC transporter is associated with multiple enterocin gene clusters; (ii) the different enterocins associated with this transporter have a saposin-like fold in common; (iii) the Mr10E component of the transporter is more conserved within its associated enterocin, while the Mr10FGH components are more conserved within the carrying species. This is the least known component of the transporter, but it has shown the greatest specificity to its corresponding enterocin. Bacteriocins are now being investigated as an alternative to antibiotics; hence, the wider or narrower distribution of the particular immunity gene should be taken into account for clinical applications to avoid the selection of resistant strains. Further research will be needed to investigate the mechanistic interactions between the Mr10E transporter component and the bacteriocin as well as the specific ecological and evolutionary mechanisms involved in the spread of the immunity transporter across multiple bacteriocins.Junta de Andalucía A-BIO-083-UGR18, BIO 309Ministerio de Ciencia e Innovación PEJ2018-003019-

    Egg Production in Poultry Farming Is Improved by Probiotic Bacteria

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    Antimicrobial resistance (AMR) is one of the most serious threats for human health in the near future. Livestock has played an important role in the appearance of antibioticresistant bacteria, intestinal dysbiosis in farming animals, or the spread of AMR among pathogenic bacteria of human concern. The development of alternatives like probiotics is focused on maintaining or improving production levels while diminishing these negative effects of antibiotics. To this end, we supplied the potential probiotic Enterococcus faecalis UGRA10 in the diet of laying hens at a final concentration of 108 Colony Forming Units per gram (CFU/g) of fodder. Its effects have been analyzed by: (i) investigating the response of the ileum and caecum microbiome; and (ii) analyzing the outcome on eggs production. During the second half of the experimental period (40 to 76 days), hens fed E. faecalis UGRA10 maintained egg production, while control animals dropped egg production. Supplementation diet with E. faecalis UGRA10 significantly increased ileum and caecum bacterial diversity (higher bacterial operational taxonomic unit richness and Faith’s diversity index) of laying hens, with animals fed the same diet showing a higher similarity in microbial composition. These results point out to the beneficial effects of E. faecalis UGRA10 in egg production. Future experiments are necessary to unveil the underlying mechanisms that mediate the positive response of animals to this treatment.This research was funded by the Spanish Ministry of Science and Innovation, Consejería de Economía, Innovación, Ciencia y Empleo (Junta de Andalucía), the University of Granada- CEI BioTic (Project No. P-BS-37), and the INTERCONECTA program (Spanish Ministry of Economy and Competitiveness). JP-S was funded by Junta de Andalucia (Proyectos de Excelencia 2011- RNM-8147)
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