Grapevine bacterial canker, which is caused by Xanthomonas campestris pv. viticola, is one of the most important grapevine diseases in the northeastern region of Brazil. This disease causes severe ...damage and represents a high potential risk to the development of Brazilian viticulture. In turn, pigmented isolates pathogenic to cashew plant, making cashew fruit unfit for sale, also have been detected in Northeastern Brazil. Given that the taxonomic position of these bacteria is unclear, the multilocus sequence analysis (MLSA) technique, average nucleotide identity (ANI) values and tetranucleotide frequency correlation coefficients (TETRA) were used to analyze their phylogenetic relationship in relation to other Xanthomonas species. X. campestris pv. viticola was closely related to X. citri pv. mangiferaeindicae (repetitive-polymerase chain reaction rep-PCR, MLSA, and ANI) and X. citri subsp. citri (MLSA and ANI). Pigmented isolates pathogenic to cashew plant were closely related to X. citri pv. anacardii (rep-PCR, MLSA, ANI, and TETRA). The results obtained in this study support the emendation of the description of X. citri pv. anacardii to include pigmented isolates of Xanthomonas pathogenic to cashew plant. In addition, the reclassification of X. campestris pv. viticola as X. citri pv. viticola comb. nov. is suggested.
The area of entrepreneurship education is developing rapidly, potentially conveying positive effects to business education, innovation and economies. Our paper seeks to analyse the entrepreneurial ...intention of a group of higher education students, and the data includes 29 interviews, administered to students of Portuguese higher education institutions. The results obtained allowed to confirm some of the aspects described in the literature, although a few divergences were also found. It was also possible to clarify some of the theories associated with barriers to entrepreneurship. The main limitations are related with the sample size, opening space for future research with larger samples. The most important implications relate to the identified need for very specific topics in entrepreneurship education. However, the key contribution of the paper also lies in its qualitative research approach.
G. metallireducens bacterium has highly versatile respiratory pathways that provide the microorganism an enormous potential for many biotechnological applications. However, little is known about the ...structural and functional properties of its electron transfer components. In this work, the periplasmic cytochrome PpcA from G. metallireducens was studied in detail for the first time using complementary biophysical techniques, including UV–visible, CD and NMR spectroscopy. The results obtained showed that PpcA contains three low-spin c-type heme groups with His-His axial coordination, a feature also observed for its homologue in G. sulfurreducens. However, despite the high sequence homology between the two cytochromes, important structural and functional differences were observed. The comparative analysis of the backbone, side chain and heme substituents NMR signals revealed differences in the relative orientation of the hemes I and III. In addition, redox titrations followed by visible spectroscopy showed that the redox potential values for PpcA from G. metallireducens (−78 and −93 mV at pH 7 and 8, respectively) are considerably less negative. Overall, this study provides biochemical and biophysical data of a key cytochrome from G. metallireducens, paving the way to understand the extracellular electron transfer mechanisms in these bacteria.
The current study aims to study Hospital volunteers' intention to stay in an organization through understanding motivation, management factors, and satisfaction. A total of 304 Hospital volunteers, ...mainly women, completed a questionnaire measuring motivations, management factors, satisfaction, and intention to stay. In this study, structural equation modeling was used. Results demonstrate that there is a positive relationship between (a) motivation and satisfaction, (b) management factors and satisfaction, (c) satisfaction and intention to stay, and (d) motivation and management factors. These results present important outcomes that should be reflected in the way organizations operate. This research indicates aspects which are most valued by volunteers and allows NPOs to design and establish appropriate and assertive management policies. La présente étude vise à examiner l'intention des hospitaliers bénévoles de rester dans une organisation, au travers de leur motivation, de leur satisfaction et de facteurs de gestion. Au total, 304 hospitaliers bénévoles (principalement des femmes) ont rempli un questionnaire mesurant les motivations, la satisfaction, les facteurs de gestion et l'intention de rester. Pour les besoins de cette étude, nous avons fait appel à une modélisation par équations structurelles. Les résultats montrent une corrélation positive entre (a) la motivation et la satisfaction; (b) les facteurs de gestion et la satisfaction; (c) la satisfaction et l'intention de rester; et (d) la motivation et les facteurs de gestion. Ces résultats ont d'importantes conséquences qui devraient influencer la manière dont fonctionnent les organisations. Cette étude indique les aspects que les bénévoles considèrent comme les plus importants; les associations à but non lucratif pourront ainsi concevoir et établir des politiques de gestion adéquates et assertives. Ziel der vorliegenden Studie ist es, die Absicht ehrenamtlicher Krankenhausmitarbeiter, längerfristig für eine Organisation tätig zu sein, zu untersuchen, indem näher auf die Aspekte Motivation, Managementfaktoren und Zufriedenheit eingegangen wird. Insgesamt 304 ehrenamtliche Krankenhausmitarbeiter, hauptsächlich Frauen, füllten einen Fragebogen aus, mithilfe dessen die Motivation, Managementfaktoren, Zufriedenheit und die Absicht einer längerfristigen Tätigkeit bewertet wurden. In der Studie wurde das Strukturgleichungsmodell angewandt. Die Ergebnisse zeigen positive Korrelationen zwischen (a) der Motivation und der Zufriedenheit, (b) den Managementfaktoren und der Zufriedenheit, (c) der Zufriedenheit und der Absicht einer längerfristigen Tätigkeit. Diese Ergebnisse präsentieren wichtige Auswirkungen, die sich in der Art und Weise, in der Organisationen operieren, widerspiegeln sollten. Die Studie weist die Aspekte auf, die von ehrenamtlich Tätigen am meisten geschätzt werden und ermöglicht es gemeinnützigen Organisationen, geeignete ausdrückliche Managementgrundsätze zu etablieren. El presente estudio tiene como objetivo estudiar la intención de los voluntarios de Hospital de permanecer en una organización mediante la comprensión de la motivación, factores de gestión y satisfacción. Un total de 304 voluntarios de Hospital, principalmente mujeres, completaron un cuestionario que medía la motivaciones, los factores de gestión, la satisfacción y la intención de seguir. En el presente estudio, se utilizó el modelo de ecuación estructural. Los resultados demuestran que existe una relación positiva entre (a) la motivación y la satisfacción, (b) los factores de gestión y la satisfacción, (c) la satisfacción y la intención de quedarse y (d) la motivación y los factores de gestión. Estos resultados presentan importantes conclusiones que deben ser reflejadas en la forma en la que operan las organizaciones. La presente investigación indica los aspectos que son más valorados por los voluntarios y permite a las organizaciones sin ánimo de lucro (OSAL/NPO) diseñar y establecer políticas de gestión apropiadas y enérgicas.
Electrogenic bacteria, such as Geobacter, can couple the oxidation of carbon sources to the reduction of extracellular electron acceptors; such acceptors include toxic and radioactive metals, as well ...as electrode surfaces, making Geobacter a suitable candidate for applied use in bioremediation and bioenergy generation. Geobacter metallireducens is more promising in this regard than the better studied Geobacter sulfurreducens, as it has more efficient Fe (III) reduction rates and can convert nitrate to ammonia. The operon responsible for nitrate reductase activity in G. metallireducens includes the gene encoding the cytochrome PpcF, which was proposed to exchange electrons with nitrate reductase. In the present work, we perform a biochemical and a biophysical characterization of PpcF. Spectroscopic techniques, including circular dichroism (CD), UV‐visible, and nuclear magnetic resonance (NMR), revealed that the cytochrome is very stable (Tm > 85 °C), contains three low‐spin hemes, and is diamagnetic (S = 0) and paramagnetic (S = 1/2) in the reduced and oxidized states, respectively. The NMR chemical shifts of the heme substituents were assigned and used to determine the heme core architecture of PpcF. Compared to the PpcA‐family from G. sulfurreducens, the spatial disposition of the hemes is conserved, but the functional properties are clearly distinct. In fact, potentiometric titrations monitored by UV‐visible absorption reveal that the reduction potential values of PpcF are significantly less negative (−56 and −64 mV, versus the normal hydrogen electrode at pH 7.0 and 8.0, respectively). NMR redox titrations showed that the order of oxidation of the hemes is IV‐I‐III, a feature not observed for G. sulfurreducens. The different redox properties displayed by PpcF, including the small redox‐Bohr effect and low reduction potential value of heme IV, were structurally rationalized and attributed to the lower number of positively charged residues located in the vicinity of heme IV. Overall, the redox features of PpcF suggest that biotechnological applications of G. metallireducens may require less negative working functional redox windows than those using by G. sulfurreducens.
Geobacter species are electrogenic bacteria capable of transferring electrons to the cell exterior, a mechanism that has been explored for different biotechnological applications. These mechanisms are shared between different species, but the redox properties of their electron transfer components appear to exhibit differences, as revealed by the distinct redox properties of G. metallireducens periplasmic cytochrome PpcF.
Infectious diseases with epizootic consequences have not been fully studied in marine mammals. Presently, the unprecedented depth of sequencing, made available by high-throughput approaches, allows ...detailed comparisons of the microbiome in health and disease. This is the first report of the striped dolphin microbiome in different body sites. Samples from one striped female edematous dolphin were acquired from a variety of body niches, including the blowhole, oral cavity, oral mucosa, tongue, stomach, intestines and genital mucosa. Detailed 16S rRNA analysis of over half a million sequences identified 235 OTUs. Beta diversity analyses indicated that microbial communities vary in structure and cluster by sample origin. Pathogenic, Gram-negative, facultative and obligate anaerobic taxa were significantly detected, including Cetobacterium, Fusobacterium and Ureaplasma. Phocoenobacter and Arcobacter dominated the oral-type samples, while Cardiobacteriaceae and Vibrio were associated with the blowhole and Photobacterium were abundant in the gut. We report for the first time the association of Epulopiscium with a marine mammal gut.
The striped dolphin microbiota shows variation in structure and diversity according to the organ type. The high dominance of Gram-negative anaerobic pathogens evidences a cetacean microbiome affected by human-related bacteria.
Bacterial blight caused by
Erwinia psidii
is considered an important disease of the guava crop in Brazil. The disease has been disseminated to different geographic areas due to the movement of ...infected but asymptomatic propagating plant material. Consequently, methods showing high specificity and sensitivity for early detection of latent infections are required to aid in the establishment of the use of pathogen-free seedlings and propagating material. In this study, an intercalating dye-based real-time PCR (qPCR) method using newly designed species-specific primers targeting the
recA
gene sequence was developed. Primer specificity was first confirmed in silico and then by PCR amplification using DNA from strains of a collection of
E. psidii
and other plant-associated bacterial species. DNA from strains of other bacterial species obtained from uninfected guava and eucalypt leaves or from other plant species were not amplified. When bacterial suspensions and purified DNA were used in qPCR, detection limits were 10
3
CFU mL
−1
and 10
2
genomic units µL
−1
, respectively. Using qPCR,
E. psidii
was detected in 100% of samples from symptomatic and in 57.1% of samples from asymptomatic trees collected in four guava orchards. The qPCR method allowed quantification of
E. psidii
populations in infected tissue of varieties Pedro Sato and Sassaoka as well as confirmation of the previously reported
E. psidii
acropetal and basipetal movement inside the plant. This new detection method with improved sensitivity has great potential not only for implementing disease diagnosis in guava and eucalypt nurseries and orchards but also for investigating relevant aspects of
E. psidii
life cycle and epidemiology.
Impact of climate change is expected to be especially noticeable at the edges of a species' distribution, where they meet suboptimal habitat conditions. In Mauritania and Iberia, two genetically ...differentiated populations of harbor porpoises (Phocoena phocoena) form an ecotype adapted to local upwelling conditions and distinct from other ecotypes further north on the NE Atlantic continental shelf and in the Black Sea. By analyzing the evolution of mitochondrial genetic variation in the Iberian population between two temporal cohorts (1990–2002 vs. 2012–2015), we report a substantial decrease in genetic diversity. Phylogenetic analyses including neighboring populations identified two porpoises in southern Iberia carrying a divergent haplotype closely related to those from the Mauritanian population, yet forming a distinct lineage. This suggests that Iberian porpoises may not be as isolated as previously thought, indicating possible dispersion from Mauritania or an unknown population in between, but none from the northern ecotype. Demo‐genetic scenario testing by approximate Bayesian computation showed that the rapid decline in the Iberian mitochondrial diversity was not simply due to the genetic drift of a small population, but models support instead a substantial decline in effective population size, possibly resulting from environmental stochasticity, prey depletion, or acute fishery bycatches. These results illustrate the value of genetics time series to inform demographic trends and emphasize the urgent need for conservation measures to ensure the viability of this small harbor porpoise population in Iberian waters.
The Iberian harbor porpoises form a small and semi‐isolated population belonging to a distinctive ecotype adapted to the upwelling system in the southern European Atlantic waters. Here, we analyzed the mitochondrial genetic variation for a sampling spanning over the past 30 years and reported a dramatic decline in diversity. Simulation‐based statistical scenario testing demonstrates that this loss of diversity corresponds to an ancient expansion, followed by a dramatic decline in the Iberian population size over the last three generations. These results lineup with field observations and call for urgent conservation actions.
Response to chemoradiotherapy (CRT) in patients with locally advanced rectal cancer (RC) is quite variable and it is urgent to find predictive biomarkers of response. We investigated miR-21 as tissue ...and plasma biomarker of response to CRT in a prospective cohort of RC patients; The expression of miR-21 was analyzed in pre- and post-CRT rectal tissue and plasma in 37 patients with RC. Two groups were defined: Pathological responders (TRG 0, 1 and 2) and non-responders (TRG 3). The association between miR-21, clinical and oncological outcomes was assessed; miR-21 was upregulated in tumor tissue and we found increased odds of overexpression in pre-CRT tumor tissue (OR: 1.63; 95% CI: 0.40-6.63,
= 0.498) and pre-CRT plasma (OR: 1.79; 95% CI: 0.45-7.19,
= 0.414) of non-responders. The overall recurrence risk increased with miR-21 overexpression in pre-CRT tumor tissue (HR: 2.175,
= 0.37); Significantly higher miR-21 expression is observed in tumor tissue comparing with non-neoplastic. Increased odds of non-response is reported in patients expressing higher miR-21, although without statistical significance. This is one of the first studies on circulating miR-21 as a potential biomarker of response to CRT in RC patients.
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