Leaf morphological characteristics and stilbene production differently affect downy mildew resistance of Vitis vinifera varieties grown in Italy

The degree of resistance to downy mildew of grape varieties belonging to the oenological tradition of Central Italy was evaluated by the analysis of plant responses to pathogen infections carried out in natural and controlled environments. Leaf morphological traits, such as hair and stomatal density, were determined for each variety, and the percentage of infected stomata and pathogen colonization of host mesophyll at 24, 48, and 72 hours post inoculation were assessed by epifluorescence microscopy. Furthermore, stilbene production at the site of Plasmopara viticola infection was analyzed at 72 hours post inoculation. Results indicate differences in resistance to downy mildew among selected varieties. Different significant values were detected among grapevines in the percentage of infected stomata and average number of successfully penetrated zoospores per stomata and per leaf surface unit. Differences also emerged in the rate of pathogen growth and stilbene production, signifying that defence mechanisms involved or induced during pathogen infection could be differentially effective among grapevine cultivars in limiting disease progression.

Leaf morphological characteristics and stilbene production differently affect downy mildew resistance of Vitis vinifera varieties grown in Italy

The degree of resistance to downy mildew of grape varieties belonging to the oenological tradition of Central Italy was evaluated by the analysis of plant responses to pathogen infections carried out in natural and controlled environments. Leaf morphological traits, such as hair and stornata! density, were determined for each variety, and the percentage of infected stornata and pathogen colonization of host mesophyll at 24, 48, and 72 hours post inoculation were assessed by epifluorescence microscopy. Furthermore, stilbene production at the site of Plasmopara viticola infection was analyzed at 72 hours post inoculation. Results indicate differences in resistance to downy mildew among selected varieties. Different significant values were detected among grapevines in the percentage of infected stornata and average number of successfully penetrated zoospores per stornata and per leaf surface unit. Differences also emerged in the rate of pathogen growth and stilbene production, signifying that defence mechanisms involved or induced during pathogen infection could be differentially effective among grapevine cultivars in limiting disease progression.Peer reviewe

Economics Students: Self-Selected in Preferences and Indoctrinated in Beliefs

There is much debate as to why economics students display more self-interested behavior than other students: whether homo economicus self-select into economics or students are instead “indoctrinated” by economics learning, and whether these effects impact on preferences or beliefs about others’ behavior. Using a classroom survey (n\u3e500) with novel behavioral questions we show that, compared to students in other majors, econ students report being: (i) more self-interested (in particular, less compassionate or averse to advantageous inequality) already in the first year and the difference remains among more senior students; (ii) more likely to think that people will be unwilling to work if unemployment benefits increase (thus, assuming others are motivated primarily by self-interest), but only among senior students. These results suggest self-selection in preferences and indoctrination in beliefs

Ex vivo innate immune cytokine signature of enhanced risk of relapsing brucellosis.

BackgroundBrucellosis, a zoonotic infection caused by one of the Gram-negative intracellular bacteria of the Brucella genus, is an ongoing public health problem in Perú. While most patients who receive standard antibiotic treatment recover, 5-40% suffer a brucellosis relapse. In this study, we examined the ex vivo immune cytokine profiles of recovered patients with a history of acute and relapsing brucellosis.Methodology/principal findingsBlood was taken from healthy control donors, patients with a history of acute brucellosis, or patients with a history of relapsing brucellosis. Peripheral blood mononuclear cells were isolated and remained in culture without stimulation or were stimulated with a panel of toll-like receptor agonists or heat-killed Brucella melitensis (HKBM) isolates. Innate immune cytokine gene expression and protein secretion were measured by quantitative real-time polymerase chain reaction and a multiplex bead-based immunoassay, respectively. Acute and relapse patients demonstrated consistently elevated cytokine gene expression and secretion levels compared to controls. Notably, these include: basal and stimulus-induced expression of GM-CSF, TNF-α, and IFN-γ in response to LPS and HKBM; basal secretion of IL-6, IL-8, and TNF-α; and HKBM or Rev1-induced secretion of IL-1β, IL-2, GM-CSF, IFN-Υ, and TNF-α. Although acute and relapse patients were largely indistinguishable by their cytokine gene expression profiles, we identified a robust cytokine secretion signature that accurately discriminates acute from relapse patients. This signature consists of basal IL-6 secretion, IL-1β, IL-2, and TNF-α secretion in response to LPS and HKBM, and IFN-γ secretion in response to HKBM.Conclusions/significanceThis work demonstrates that informative cytokine variations in brucellosis patients can be detected using an ex vivo assay system and used to identify patients with differing infection histories. Targeted diagnosis of this signature may allow for better follow-up care of brucellosis patients through improved identification of patients at risk for relapse

Hacia un modelo teórico explicativo de la innovación en los distritos de turismo cultural

This paper presents a theoretical model that analyses the direct effect of social capital on innovation, as well as the mediating effect of acquisition of knowledge between both variables in firms in a cultural tourist district. We analyse the bidimensional nature of social capital —bonded capital and bridging capital—. It is an approach to the context and characteristics of cultural tourist districts. We point out several future investigation lines related to the differentiation between types of knowledge and innovation. We propose recommendations about the orientation of relations between companies and institutions of cultural tourist districts.En este trabajo se plantea un modelo teórico que analiza el efecto directo, y mediado por la adquisición de conocimiento, del capital social sobre la innovación desarrollada por las empresas pertenecientes a un distrito turístico cultural. Se analiza el carácter bidimensional del capital social —bonded capital y bridging capital—. Se realiza una aproximación al contexto y las caracteristicas de los distritos turísticos culturales. Se establecen diversas líneas futuras de trabajo vinculadas a la diferenciación entre tipos de conocimiento y de innovación. Se proponen recomendaciones sobre la orientación de las relaciones entre las empresas y con las instituciones de los distritos turísticos culturales

Organisational Culture and Workplace Corruption in Government Hospitals

This study examines corruption attitudes and norms in government hospitals in the Philippines. It tests a culture-building model that advocates communication of desired values, leadership role modelling, employee role modelling, alignment of systems and structures, training and evaluation, and reinforcement. Results reveal components that influence corruption attitudes and norms. Communication predicted individual attitudes or acceptability of corrupt acts. Leadership, systems, and controls predicted the prevalence of corrupt acts. Employee role modelling predicted both acceptability of and the prevalence of corrupt acts. In addition, there is a positive relationship between individual attitudes and organisation norms reinforcing the dyadic relationship between the two

Modeling the ionizing spectra of H ii regions: individual stars versus stellar ensembles

Aims. We study how IMF sampling affects the ionizing flux and emission line spectra of low mass stellar clusters. Methods. We performed 2 x 10^6 Monte Carlo simulations of zero-age solar-metallicity stellar clusters covering the 20 - 10^6 Mo mass range. We study the distribution of cluster stellar masses, Mclus, ionizing fluxes, Q(H0), and effective temperatures, Tclus. We compute photoionization models that broadly describe the results of the simulations and compare them with photoionization grids. Results. Our main results are: (a) A large number of low mass clusters (80% for Mclus = 100 Mo) are unable to form an H ii region. (b) There are a few overluminous stellar clusters that form H ii regions. These overluminous clusters preserve statistically the mean value of obtained by synthesis models, but the mean value cannot be used as a description of particular clusters. (c) The ionizing continuum of clusters with Mclus < 10^4 Mo is more accurately described by an individual star with self-consistent effective temperature(T*) and Q(H0) than by the ensemble of stars (or a cluster Tclus) produced by synthesis models. (d)Photoionization grids of stellar clusters can not be used to derive the global properties of low mass clusters. Conclusions. Although variations in the upper mass limit, mup, of the IMF would reproduce the effects of IMF sampling, we find that an ad hoc law that relates mup to Mclus in the modelling of stellar clusters is useless, since: (a) it does not cover the whole range of possible cases, and (b) the modelling of stellar clusters with an IMF is motivated by the need to derive the global properties of the cluster: however, in clusters affected by sampling effects we have no access to global information of the cluster but only particular information about a few individual stars.Comment: A&A in pres

Macro- and microscopic leaf characteristics of six grapevine genotypes (Vitis spp.) with different susceptibilities to grapevine downy mildew

This work reports the leaf morphology of six grapevine genotypes, five belonging to Vitis vinifera and one to Vitis riparia. Earlier studies on these genotypes showed different levels of susceptibility to grapevine downy mildew (Plasmopara viticola). The aim of this work was to detect differences between the leaf morphology of these cultivars at the macro- and microscopic levels, and to characterize morphological traits which could be associated with susceptibility and resistance to downy mildew. An ampelographic description of each genotype was used to develop a scheme illustrating the characteristic leaf morphology. The density and morphology of the trichomes and the stomatal index was assessed by means of microscopical techniques. Distinct macro and microscope differences among the genotypes were seen. No clear relation between ampelographic characteristics and susceptibility to downy mildew was observed. The two cultivars that in earlier studies were found to be the least susceptible to downy mildew were the most similar in terms of their spongy mesophyll. Both showed very little or no wax on the abaxial surface of their leaves.

The threat of the ambrosia beetle Megaplatypus mutatus (Chapuis) (=Platypus mutatus Chapuis) to world poplar resources

We describe the life cycle of Megaplatypus mutatus (Chapuis) (=Platypus mutatus) and the damage it causes to poplar resources in Argentina. This insect, native to the subtropical and tropical areas of South America, has extended its range into temperate regions, reaching as far south as Neuquén in Argentinean Patagonia. The damage is caused by the adult insects, which bore large gallery systems into living poplars (Populus spp.), willows (Salix spp.) and many other broadleaf species, including important fruit trees species such as apples (Malus spp.), walnuts (Juglans spp.) and avocados (Persea spp.). The galleries degrade the lumber and weaken the tree stems, which often then break during windstorms. A recent introduction of M. mutatus to Italy demonstrates that this insect can be transported long distances between countries, and therefore presents a threat worldwide - particularly to poplar cultivation. We review the taxonomic nomenclature for this pest, provide a summary of the life cycle, hosts and damage and summarize actions taken to reduce the risk of introduction of M. mutatus to Canada.Facultad de Ciencias Agrarias y Forestale