Bacillus subtilis RecU Holliday-junction resolvase modulates RecA activities

The Bacillus subtilis RecU protein is able to catalyze in vitro DNA strand annealing and Holliday-junction resolution. The interaction between the RecA and RecU proteins, in the presence or absence of a single-stranded binding (SSB) protein, was studied. Substoichiometric amounts of RecU enhanced RecA loading onto single-stranded DNA (ssDNA) and stimulated RecA-catalyzed D-loop formation. However, RecU inhibited the RecA-mediated three-strand exchange reaction and ssDNA-dependent dATP or rATP hydrolysis. The addition of an SSB protein did not reverse the negative effect exerted by RecU on RecA function. Annealing of circular ssDNA and homologous linear 3′-tailed double-stranded DNA by RecU was not affected by the addition of RecA both in the presence and in the absence of SSB. We propose that RecU modulates RecA activities by promoting RecA-catalyzed strand invasion and inhibiting RecA-mediated branch migration, by preventing RecA filament disassembly, and suggest a potential mechanism for the control of resolvasome assembly

Fur Activates the Expression of Salmonella enterica Pathogenicity Island 1 by Directly Interacting with the hilD Operator In Vivo and In Vitro

Previous studies have established that the expression of Salmonella enterica pathogenicity island 1 (SPI1), which is essential for epithelial invasion, is mainly regulated by the HilD protein. The ferric uptake regulator, Fur, in turn modulates the expression of the S. enterica hilD gene, albeit through an unknown mechanism. Here we report that S. enterica Fur, in its metal-bound form, specifically binds to an AT-rich region (BoxA), located upstream of the hilD promoter (PhilD), at position -191 to -163 relative to the hilD transcription start site. Furthermore, in a PhilD variant with mutations in BoxA, PhilD*, Fur·Mn2+ binding is impaired. In vivo experiments using S. enterica strains carrying wild-type PhilD or the mutant variant PhilD* showed that Fur activates hilD expression, while in vitro experiments revealed that the Fur·Mn2+ protein is sufficient to increase hilD transcription. Together, these results present the first evidence that Fur·Mn2+, by binding to the upstream BoxA sequence, directly stimulates the expression of hilD in S. enterica

Epidemiology of pediatric facial trauma in Chile: a retrospective study of 7,617 cases in 3 years

Objectives: To describe the epidemiology of facial trauma injuries in a group of Chilean children aged 15 years or less. Study Design: Retrospective study of case series. Between 2006 and 2009, clinical records of 293,090 patients were reviewed. Data of patients with trauma injuries to the face were collected and evaluated for: age, sex, day and month of hospital admission, cause of injury, anatomical location, type of injury and presence of associated injuries. Results: A total of 7,617 patients with 8,944 injuries were found. Boy to girl ratio was 1,7:1. Preschool age children were most frequently affected. Main cause of injury were falls, soft tissue injuries the most common type of injury. Associated injuries occurred in 11% of cases. Conclusions: Facial trauma presents a significant frequency in the group of Chilean children studied. Preeschool age boys were prone to present facial trauma of mild severity associated to falls

DisA Limits RecG Activities at Stalled or Reversed Replication Forks

The DNA damage checkpoint protein DisA and the branch migration translocase RecG are implicated in the preservation of genome integrity in reviving haploid Bacillus subtilis spores. DisA synthesizes the essential cyclic 3′, 5′-diadenosine monophosphate (c-di-AMP) second messenger and such synthesis is suppressed upon replication perturbation. In vitro, c-di-AMP synthesis is suppressed when DisA binds DNA structures that mimic stalled or reversed forks (gapped forks or Holliday junctions [HJ]). RecG, which does not form a stable complex with DisA, unwinds branched intermediates, and in the presence of a limiting ATP concentration and HJ DNA, it blocks DisA-mediated c-di-AMP synthesis. DisA pre-bound to a stalled or reversed fork limits RecG-mediated ATP hydrolysis and DNA unwinding, but not if RecG is pre-bound to stalled or reversed forks. We propose that RecG-mediated fork remodeling is a genuine in vivo activity, and that DisA, as a molecular switch, limits RecG-mediated fork reversal and fork restoration. DisA and RecG might provide more time to process perturbed forks, avoiding genome breakage.This work was supported by the Ministerio de Ciencia e Innovación, Agencia Estatal de Investigación (MCIU/AEI)/FEDER PGC2018-097054-B-I00 to S.A. and J.C.A

A solution for tracking visitors in Smart Shopping environments: A real platform implementation based on Raspberry Pi

In parallel to the explosion of the use of wireless technologies to connect devices, the scientific community is continually aiming to take advantage of such technologies to provide new services. In this sense, there have been many attempts to exploit the information provided by IEEE802.11 and Bluetooth interfaces, commonly found in most of the smartphones that are being used at the time of writing. In this paper we describe a novel deployment that fosters such approach. Furthermore, the measurements that are gathered are made available, thanks to its integration within the SmartSantander testbed, and to the federation with complementary testbeds. The federation platform and the described deployment are outcomes of the FESTIVAL collaborative project (Europe-Japan). Besides depicting the corresponding software architecture, the paper also discusses some preliminary results that are used to assess the feasibility of the proposed scheme.This work was funded in part by the European Union’s Horizon 2020 Programme of the FESTIVAL project (Federated Interoperable Smart ICT Services Development and Testing Platforms) under grant agreement 643275, and from the Japanese National Institute of Information and Communications Technology. This work has been also supported by the Spanish Government (Ministerio de Economía y Competitividad, Fondo Europeo de Desarrollo Regional, FEDER) by means of the project ADVICE (TEC2015-71329-C2-1-R)

Chromosomal transformation in Bacillus subtilis is a non-polar recombination reaction

Natural chromosomal transformation is one of the primary driving forces of bacterial evolution. This reaction involves the recombination of the internalized linear single-stranded (ss) DNA with the homologous resident duplex via RecA-mediated integration in concert with SsbA and DprA or RecO. We show that sequence divergence prevents Bacillus subtilis chromosomal transformation in a log-linear fashion, but it exerts a minor effect when the divergence is localized at a discrete end. In the nucleotide bound form, RecA shows no apparent preference to initiate recombination at the 3′- or 5′-complementary end of the linear duplex with circular ssDNA, but nucleotide hydrolysis is required when heterology is present at both ends. RecA·dATP initiates pairing of the linear 5′ and 3′ complementary ends, but only initiation at the 5′-end remains stably paired in the absence of SsbA. Our results suggest that during gene transfer RecA·ATP, in concert with SsbA and DprA or RecO, shows a moderate preference for the 3′-end of the duplex. We show that RecA-mediated recombination initiated at the 3′- or 5′-complementary end might have significant implication on the ecological diversification of bacterial species with natural transformation

Bacillus subtilisRecO and SsbA are crucial for RecA-mediated recombinational DNA repair

Genetic data have revealed that the absence of Bacillus subtilis RecO and one of the end-processing avenues (AddAB or RecJ) renders cells as sensitive to DNA damaging agents as the null recA, suggesting that both end-resection pathways require RecO for recombination. RecA, in the rATP·Mg2+ bound form (RecA·ATP), is inactive to catalyze DNA recombination between linear double-stranded (ds) DNA and naked complementary circular single-stranded (ss) DNA. We showed that RecA·ATP could not nucleate and/or polymerize on SsbA·ssDNA or SsbB·ssDNA complexes. RecA·ATP nucleates and polymerizes on RecO·ssDNA·SsbA complexes more efficiently than on RecO·ssDNA·SsbB complexes. Limiting SsbA concentrations were sufficient to stimulate RecA·ATP assembly on the RecO·ssDNA·SsbB complexes. RecO and SsbA are necessary and sufficient to ‘activate’ RecA·ATP to catalyze DNA strand exchange, whereas the AddAB complex, RecO alone or in concert with SsbB was not sufficient. In presence of AddAB, RecO and SsbA are still necessary for efficient RecA·ATP-mediated three-strand exchange recombination. Based on genetic and biochemical data, we proposed that SsbA and RecO (or SsbA, RecO and RecR in vivo) are crucial for RecA activation for both, AddAB and RecJ–RecQ (RecS) recombinational repair pathways

Roles of bacillus subtilis Dpra and Ssba in RecA-mediated genetic recombination

Bacillus subtilis competence-induced RecA, SsbA, SsbB, and DprA are required to internalize and to recombine single-stranded (ss) DNA with homologous resident duplex. RecA, in the ATP·Mg2+-bound form (RecA·ATP), can nucleate and form filament onto ssDNA but is inactive to catalyze DNA recombination. We report that SsbA or SsbB bound to ssDNA blocks the RecA filament formation and fails to activate recombination. DprA facilitates RecA filamentation; however, the filaments cannot engage in DNA recombination. When ssDNA was preincubated with SsbA, but not SsbB, DprA was able to activate DNA strand exchange dependent on RecA·ATP. This work demonstrates that RecA·ATP, in concert with SsbA and DprA, catalyzes DNA strand exchange, and SsbB is an accessory factor in the reaction. In contrast, RecA·dATP efficiently catalyzes strand exchange even in the absence of single-stranded binding proteins or DprA, and addition of the accessory factors marginally improved it. We proposed that the RecA-bound nucleotide (ATP and to a lesser extent dATP) might dictate the requirement for accessory factors

New Perspectives for UAV-Based Modelling the Roman Gold Mining Infrastructure in NW Spain

This contribution discusses the potential of UAV-assisted (unmanned aerial vehicles) photogrammetry for the study and preservation of mining heritage sites using the example of Roman gold mining infrastructure in northwestern Spain. The study area represents the largest gold area in Roman times and comprises 7 mining elements of interest that characterize the most representative examples of such ancient works. UAV technology provides a non-invasive procedure valuable for the acquisition of digital information in remote, difficult to access areas or under the risk of destruction. The proposed approach is a cost-effective, robust and rapid method for image processing in remote areas were no traditional surveying technologies are available. It is based on a combination of data provided by aerial orthoimage and LiDAR (Light Detection and Ranging) to improve the accuracy of UAV derived data. The results provide high-resolution orthomosaic, DEMs and 3D textured models that aim for the documentation of ancient mining scenarios, providing high-resolution digital information that improves the identification, description and interpretation of mining elements such as the hydraulic infrastructure, the presence of open-cast mines which exemplifies the different exploitation methods, and settlements. However, beyond the scientific and technical information provided by the data, the 3D documentation of ancient mining scenarios is a powerful tool for an effective and wider public diffusion ensuring the visualization, preservation and awareness over the importance and conservation of world mining heritage sites

Caracterização dos fatores predisponentes do comportamento sexual em casais inférteis. Guise. Janeiro dezembro. 2018

Introducción: la infertilidad ha aumentado al nivel mundial como consecuencia del incremento de las infecciones de transmisión sexual y la enfermedad inflamatoria pélvica, que dejan como secuelas la obstrucción de las trompas uterinas, además de otros factores asociados como las infecciones vaginales, el aborto provocado y sus complicaciones infecciosas.Objetivo: caracterizar factores predisponentes de la conducta sexual en las parejas infértiles en Guisa. Métodos: se realizó un estudio observacional, retrospectivo.  Las variables utilizadas en el estudio fueron edad de las mujeres, número de abortos, antecedentes de infección vaginal (por tricomonas, cándidas, clamidias y vaginosis bacteriana).  Para la realización de la investigación se revisaron las historias clínicas de todas las pacientes que acudieron a consulta de infertilidad durante el periodo de estudio y se confeccionó una planilla de recogida de datos.  El universo estuvo constituido por las 105 pacientes atendidas en consulta de infertilidad y la muestra se conformó con 92 pacientes que cumplieron los criterios de inclusión. Resultados: predominaron las pacientes con edad promedio entre 25-29 años, los factores predisponentes como los abortos provocados, la infección vaginal por clamidia y la salpingitis como causa más frecuente de infertilidad.Conclusiones: la prevalencia de la infertilidad en Guisa es alta, puede ser prevenible si se manejan de forma integral los factores que la originan. Su abordaje integral y precoz puede disminuir su incidencia.Introduction: infertility has increased worldwide as a consequence of the increase in sexually transmitted infections and pelvic inflammatory disease, which leave as sequelae the obstruction of the uterine tubes, in addition to other associated factors such as vaginal infections, induced abortion and its infectious complications. Objective: to characterize predisposing factors of sexual behavior in infertile couples in Guisa.Methods: an observational, retrospective study was carried out. The variables used in the study were age of the women, number of abortions, history of vaginal infection (due to trichomonas, candida, chlamydia and bacterial vaginosis). To carry out the research, the medical records of all the patients who attended the infertility consultation during the study period were reviewed and a data collection sheet was prepared. The universe consisted of 105 patients seen in infertility consultation and the sample was made up of 92 patients who met the inclusion criteria.Results: patients with an average age between 25-29 years prevailed, predisposing factors such as induced abortions, vaginal chlamydial infection and salpingitis as the most frequent cause of infertility. Conclusions: the prevalence of infertility in Guisa is high, it can be preventable if the factors that originate it are managed in an integral way. Its comprehensive and early approach can reduce its incidence.Introdução: a infertilidade tem aumentado mundialmente como consequência do aumento das infecções sexualmente transmissíveis e doenças inflamatórias pélvicas, que deixam como sequelas a obstrução das tubas uterinas, além de outros fatores associados como infecções vaginais, aborto induzido e suas complicações infecciosas.Objetivo: caracterizar os fatores predisponentes do comportamento sexual em casais inférteis da Guisa. Métodos: foi realizado um estudo observacional retrospectivo. As variáveis utilizadas no estudo foram idade das mulheres, número de abortos, história de infecção vaginal (por tricomonas, candida, clamídia e vaginose bacteriana). Para a realização da pesquisa, foram revisados os prontuários de todas as pacientes que compareceram à consulta de infertilidade no período do estudo e elaborada uma ficha de coleta de dados. O universo foi constituído por 105 pacientes atendidos em consulta de infertilidade e a amostra foi composta por 92 pacientes que atenderam aos critérios de inclusão.Resultados: prevaleceram pacientes com idade média entre 25-29 anos, fatores predisponentes como aborto induzido, infecção vaginal por clamídia e salpingite como a causa mais frequente de infertilidade. Conclusões: a prevalência de infertilidade na Guisa é elevada, podendo ser evitada se os fatores que a originam forem geridos de forma integral. Sua abordagem abrangente e precoce pode reduzir sua incidência