Gell-Mann and Low formula for degenerate unperturbed states

The Gell-Mann and Low switching allows to transform eigenstates of an unperturbed Hamiltonian $H_0$ into eigenstates of the modified Hamiltonian $H_0 + V$. This switching can be performed when the initial eigenstate is not degenerate, under some gap conditions with the remainder of the spectrum. We show here how to extend this approach to the case when the ground state of the unperturbed Hamiltonian is degenerate. More precisely, we prove that the switching procedure can still be performed when the initial states are eigenstates of the finite rank self-adjoint operator \cP_0 V \cP_0, where \cP_0 is the projection onto a degenerate eigenspace of $H_0$

Wild Boar and Red Deer Display High Prevalences of Tuberculosis-Like Lesions in Spain

We describe the distribution of tuberculosis-like lesions (TBL) in wild boar (Sus scrofa) and red deer (Cervus elaphus) in Spain. Animals with TBL were confirmed in 84.21% of mixed populations (n = 57) of red deer and wild boar and in 75% of populations of wild boar alone (n = 8) in central and southern Spain (core area). The prevalence of TBL declined towards the periphery of this region. In the core area, the prevalence ranged up to 100% in local populations of wild boar (mean estate prevalence 42.51%) and up to 50% in red deer (mean estate prevalence 13.70%). We carried out exploratory statistical analyses to describe the epidemiology of TBL in both species throughout the core area. Prevalence of TBL increased with age in both species. Wild boar and red deer mean TBL prevalence at the estate level were positively associated, and lesion scores were consistently higher in wild boars than in red deer. The wild boar prevalence of TBL in wild boar did not differ between populations that were or were not cohabiting with red deer. Amongst the wild boars with TBL, 61.19% presented generalized lesions, and the proportion of generalized cases was similar between sex and age classes. In red deer, 57.14% of TBL-positive individuals presented generalized lesions, and the percentage of generalized cases increased with age class, but did not differ between the sexes. These results highlight the potential importance of wild boar and red deer in the maintenance of tuberculosis in south central Spain

Progress in the control of bovine tuberculosis in Spanish wildlife

Special issue: 5th International Conference on Mycobacterium bovis.-- HAL Id: hal-00701898Despite the compulsory test and slaughter campaigns in cattle, bovine tuberculosis (bTB) is still present in Spain, and the role of wildlife reservoirs is increasingly recognized. We provide an update on recent progress made in bTB control in Spanish wildlife, including aspects of epidemiology, surveillance, host-pathogen interaction and wildlife vaccination.At the high densities and in the particular circumstances of Mediterranean environments, wild ungulates, mainly Eurasian wild boar and red deer, are able to maintain Mycobacterium bovis circulation even in absence of domestic livestock. Infection is widespread among wild ungulates in the south of the country, local infection prevalence being as high as 52% in wild boar and 27% in red deer. Risk factors identified include host genetic susceptibility, abundance, spatial aggregation at feeders and waterholes, scavenging, and social behaviour. An increasing trend of bTB compatible lesions was reported among wild boar and red deer inspected between 1992 and 2004 in Southwestern Spain. Sporadic cases of badger TB have been detected, further complicating the picture.Gene expression profiles were characterized in European wild boar and Iberian red deer naturally infected with M. bovis. The comparative analysis of gene expression profiles in wildlife hosts in response to infection advanced our understanding of the molecular mechanisms of infection and pathogenesis, revealed common and distinctive host responses to infection and identified candidate genes associated with resistance to bTB and for the characterization of host response to infection and vaccination.Ongoing research is producing valuable knowledge on vaccine delivery, safety and efficacy issues. Baits for the oral delivery of BCG vaccine preparations to wild boar piglets were developed and evaluated. The use of selective feeders during the summer was found to be a potentially reliable bait-deployment strategy. Safety experiments yielded no isolation of M. bovis BCG from faeces, internal organs at necropsy and the environment, even after oral delivery of very high doses. Finally, preliminary vaccination and challenge experiments suggested that a single oral BCG vaccination may protect wild boar from infection by a virulent M. bovis field strain.Studies on TB at IREC are supported by Grupo Santander – Fundacion Marcelino Botin, and by TB-STEP EU FP7 212414, INIA-MICINN FAU 06-017, and PAI07-0062-6611 Castilla – La Mancha.Peer Reviewe

Serologic tests for detecting antibodies against Mycobacterium bovis and Mycobacterium avium subspecies paratuberculosis in Eurasian wild boar (Sus scrofa scrofa)

Boadella et al.New tools to detect exposure of free-range Eurasian wild boar (Sus scrofa scrofa) to pathogenic mycobacteria would be valuable for improved disease surveillance and wildlife management. Two hundred sera from wild boar of known Mycobacterium bovis infection status were used to evaluate test suitability for the detection of antibodies against M. bovis and Mycobacterium avium subsp. paratuberculosis (or crossreacting members of the M. avium complex). Two traditional enzyme-linked immunosorbent assays were evaluated using M. bovis purified protein derivative (bPPD) and paratuberculosis protoplasmatic antigen 3 (PPA3) as antigens, respectively, and a new point-of-care test format for bovine tuberculosis (bTB) that uses the innovative dual-path platform (DPP TB) test. The effect of individual factors (sex, age, lesions) on the diagnostic performance of the serologic tests was also determined. Although the DPP had a sensitivity of 89.6% and a specificity of 90.4%, for bPPD, the sensitivity was 79.2% and the specificity 100%. Both tests had a kappa agreement of 0.80. Sixty-five of 68 (95.6%) wild boar sera with antibodies against the PPA3 antigen corresponded to known M. bovis-infected wild boar. Significant differences were not observed in the bPPD and DPP readings among lesion categories or between age classes. A slight sex-related difference in sensitivity toward males in the DPP was found, but it was not detected in the bPPD enzyme-linked immunosorbent assay. The results support the use of antibody-based diagnostic tests for both large-scale and individual bTB testing of Eurasian wild boar and suggest that wild boar cannot be used as sentinels for infections caused by M. avium complex members.The current study is a contribution to MCINN Plan Nacional I+D+i research grant AGL2008-03875 and FEDER and to FP7 EU grant TB-STEP (212414). Studies on diseases shared between domestic animals and wildlife are also supported by Grupo Santander Fundacion Marcelino Botin. Tania Carta acknowledges a grant from Regione Sardegna.Peer Reviewe

Carbon incorporation in MOCVD of MoS2 thin films grown from an organosulfide precursor

Altres ajuts: CERCA Programme/Generalitat de CatalunyaWith the rise of two-dimensional (2D) transition-metal dichalcogenide (TMD) semiconductors and their prospective use in commercial (opto)electronic applications, it has become key to develop scalable and reliable TMD synthesis methods with well-monitored and controlled levels of impurities. While metal-organic chemical vapor deposition (MOCVD) has emerged as the method of choice for large-scale TMD fabrication, carbon (C) incorporation arising during MOCVD growth of TMDs has been a persistent concern-especially in instances where organic chalcogen precursors are desired as a less hazardous alternative to more toxic chalcogen hydrides. However, the underlying mechanisms of such unintentional C incorporation and the effects on film growth and properties are still elusive. Here, we report on the role of C-containing side products of organosulfur precursor pyrolysis in MoS2 thin films grown from molybdenum hexacarbonyl Mo(CO)6 and diethyl sulfide (CH3CH2)2S (DES). By combining in situ gas-phase monitoring with ex situ microscopy and spectroscopy analyses, we systematically investigate the effect of temperature and Mo(CO)6/DES/H2 gas mixture ratios on film morphology, chemical composition, and stoichiometry. Aiming at high-quality TMD growth that typically requires elevated growth temperatures and high DES/Mo(CO)6 precursor ratios, we observed that temperatures above DES pyrolysis onset (â 600 °C) and excessive DES flow result in the formation of nanographitic carbon, competing with MoS2 growth. We found that by introducing H2 gas to the process, DES pyrolysis is significantly hindered, which reduces carbon incorporation. The C content in the MoS2 films is shown to quench the MoS2 photoluminescence and influence the trion-To-exciton ratio via charge transfer. This finding is fundamental for understanding process-induced C impurity doping in MOCVD-grown 2D semiconductors and might have important implications for the functionality and performance of (opto)electronic devices

Complete genome sequences of field isolates of Mycobacterium bovis and Mycobacterium caprae

Here we report the complete genome sequences of field isolates of Mycobacterium bovis and the related mycobacterial species, Mycobacterium caprae. The genomes of three M. bovis (MB1, MB3, MB4) and one M. caprae (MB2) field isolates with different virulence, prevalence, and host distribution phenotypes were sequenced.This research was supported by grant AGL2011-30041 from the Ministerio de Economía y Competitividad, Spain, by the Programa de Tecnologías Avanzadas en Vigilancia Sanitaria (TAVS) from the Comunidad de Madrid (ref. S2013/ABI-2747), the EU H2020 COllaborative Management Platform for detection and Analyses of (Re-) emerging and foodborne outbreaks in Europe (COMPARE) Grant 377/14, and by the EU FP7 grants ANTIGONE (project number 278976) and WildTBvac (project number 613779).Peer Reviewe

Factors associated with producing a scientific publication during medical training: evidence from a cross-sectional study of 40 medical schools in Latin America [version 2; peer review: 2 approved]

"Background: Scientific publication during medical training is key to promoting enduring cutting-edge knowledge. The promotion of science among medical students in Latin America is a multisectoral issue that is hampered by the lack of governmental knowledge to invest in national research, as well as by the lack of support from local universities. This study aims to determine the factors associated with the production of a scientific publication during medical training among Latin American medical students of local scientific societies. Methods: This is a secondary data analysis of a cross-sectional study conducted in 2016 that assessed the use of information and communication technologies (ICTs) among medical students from 40 local scientific societies of medical students affiliated with FELSOCEM. Teams from each local scientific society surveyed self-reported scientific publications and explored their association with socioeconomic, academic, and research training conditions. We applied nested models to identify the covariates associated with selfreported scientific publication, obtaining a parsimonious mixedeffects multilevel model grouped by medical scientific society. Results: Of 11,587 participants, the prevalence of scientific publications increased in 36% among medical students affiliated to a Scientific Society of Medical Students [parsimonious prevalence ratio (pPR)=1.36, 95%CI=1.16–1.59], 51% among medical students with advanced English proficiency [pPR=1.51, 95%CI=1.21 – 1.87], 85% among medical students who attended a scientific writing skills course [pPR=1.85, 95%CI=1.59–2.15], 81% among medical students who use Sci-Hub [pPR=1.81, 95%CI=1.50–2.20], and 108% among medical students who have access to a pirated academic account [pPR=2.08, 95%CI=1.83–2.36]. Conclusions: Producing a scientific publication among medical students is associated with being affiliated to a scientific society of medical students, English proficiency, training in scientific writing, use of Sci-Hub, and pirated academic accounts. The results will help clinical educators and medical programs improve resources for training students in high-quality research

Complex links between natural tuberculosis and porcine circovirus type 2 infection in wild boar

Individuals in natural populations are exposed to a diversity of pathogens which results in coinfections. The aim of this study was to investigate the relation between natural infection with tuberculosis (TB) due to infection by bacteria of the Mycobacterium tuberculosis complex and porcine circovirus type 2 (PCV2) in free-ranging Eurasian wild boar (Sus scrofa). Apparent prevalence for TB lesions and PCV2 infection was extremely high in all age classes, including piglets (51% for TB; 85.7% for PCV2). Modeling results revealed that the relative risk of young (less than 2 years old) wild boar to test positive to PCV2 PCR was negatively associated with TB lesion presence. Also, an interaction between TB, PCV2, and body condition was evidenced: in wild boar with TB lesions probability of being PCV2 PCR positive increased with body condition, whereas this relation was negative for wild boar without TB lesions. This study provides insight into the coinfections occurring in free-ranging host populations that are naturally exposed to several pathogens at an early age. Using TB and PCV2 as a case study, we showed that coinfection is a frequent event among natural populations that takes place early in life with complex effects on the infections and the hosts.This is a contribution to Plan Nacional I + D + i AGL2011-30041 from MINECO and ANTIGONE (Project no. 278976). Ph.D students (BBB, IDD, and JAB) were supported by predoctoral grants from JCCM and MINECO.Peer Reviewe

Experimental infection of Eurasian wild boar with Mycobacterium avium subsp. avium

The Eurasian wild boar (Sus scrofa) is increasingly relevant as a host for several pathogenic mycobacteria. We aimed to characterize the first experimental Mycobacterium avium subsp. avium (MAA) infection in wild boar in order to describe the lesions and the immune response as compared to uninfected controls. Twelve 1-4-month-old wild boar piglets were housed in class III bio-containment facilities. Four concentrations of MAA suspension were used: 10, 102 and 104 mycobacteria (2 animals each, oropharyngeal route) and 2.5×106 mycobacteria (2 animals each by the oropharyngeal and nasal routes). No clinical signs were observed and pathology evidenced a low pathogenicity of this MAA strain for this particular host. Bacteriological and pathological evidence of successful infection after experimental inoculation was found for the group challenged with 2.5×106 mycobacteria. These four wild boar showed a positive IFN-γ response to the avian PPD and the real-time RT-PCR data revealed that three genes, complement component C3, IFN-γ and RANTES, were significantly down regulated in infected animals. These results were similar to those found in naturally and experimentally M. bovis-infected wild boar and may constitute biomarkers of mycobacterial infection in this species.The study was funded by INIA-MICINN research grant FAU2006-00017 and Plan NacionalAGL2008-03875. Studies on TB at IREC are also supported by Grupo Santander—Fundación Marcelino Botin.Peer Reviewe