Evaluation of a Pomegranate Peel Extract as an Alternative Means to Control Olive Anthracnose

Olive anthracnose is caused by different species of Colletotrichum spp. and may be regarded as the most damaging disease of olive fruit worldwide, greatly affecting quality and quantity of the productions. A pomegranate peel extract (PGE) proved very effective in controlling the disease. The extract had a strong in vitro fungicidal activity against Colletotrichum acutatum sensu stricto, was very effective in both preventive and curative trials with artificially inoculated fruit, and induced resistance in treated olive tissues. In field trials, PGE was significantly more effective than copper, which is traditionally used to control the disease. The highest level of protection was achieved by applying the extract in the early ascending phase of the disease outbreaks because natural rots were completely inhibited with PGE at 12 g/liter and were reduced by 98.6 and by 93.0% on plants treated with PGE at 6 and 3 g/liter, respectively. Two treatments carried out 30 and 15 days before the expected epidemic outbreak reduced the incidence of the disease by 77.6, 57.0, and 51.8%, depending on the PGE concentration. The analysis of epiphytic populations showed a strong antimicrobial activity of PGE, which sharply reduced both fungal and bacterial populations. Because PGE was obtained from a natural matrix using safe chemicals and did not have any apparent phytotoxic effect on treated olive fruit, it may be regarded as a safe and effective natural antifungal preparation to control olive anthracnose and improve olive productions

A Cytosine Methyltransferase Homologue Is Essential for Sexual Development in Aspergillus nidulans

Background: The genome defense processes RIP (repeat-induced point mutation) in the filamentous fungus Neurospora crassa, and MIP (methylation induced premeiotically) in the fungus Ascobolus immersus depend on proteins with DNA methyltransferase (DMT) domains. Nevertheless, these proteins, RID and Masc1, respectively, have not been demonstrated to have DMT activity. We discovered a close homologue in Aspergillus nidulans, a fungus thought to have no methylation and no genome defense system comparable to RIP or MIP. Principal Findings: We report the cloning and characterization of the DNA methyltransferase homologue A (dmtA) gene from Aspergillus nidulans. We found that the dmtA locus encodes both a sense (dmtA) and an anti-sense transcript (tmdA). Both transcripts are expressed in vegetative, conidial and sexual tissues. We determined that dmtA, but not tmdA, is required for early sexual development and formation of viable ascospores. We also tested if DNA methylation accumulated in any of the dmtA/tmdA mutants we constructed, and found that in both asexual and sexual tissues, these mutants, just like wild-type strains, appear devoid of DNA methylation. Conclusions/Significance: Our results demonstrate that a DMT homologue closely related to proteins implicated in RIP and MIP has an essential developmental function in a fungus that appears to lack both DNA methylation and RIP or MIP. It remains formally possible that DmtA is a bona fide DMT, responsible for trace, undetected DNA methylation that i

The relationship between institutions and value creation in software development models

Purpose: The purpose of this paper is to analyse the possibility for firms to consider institutional settings to systematically direct dispersed individual efforts of discovery and invention towards objects (products or processes) of their interest in order to enhance their value creation capacity. Design/methodology/approach: The authors conduct a comparative analysis of the different institutional settings within which software products are invented and produced – closed producer-centred model, open user-centred model, and hybrid interactive producer-user model. Findings: The authors draw indications regarding the possibility to design institutional settings for value creation and the potential pitfalls tied to these strategic tools. Originality/value: A theoretical framework is elaborated in order to understand the different ways in which institutional contexts influence and direct value creation processes. The model analysed shows the firms’ deliberate attempt to stimulate a dynamic process of social interaction and communication which may foster higher levels of creativity and innovation. In order to guarantee the necessary accessibility and to sufficiently motivate external programmers towards the perception of a new code, the firm has to surrender the traditional source through which it appropriates value: barriers to the accessibility of the code developed through IPRs. The adoption of an institutional setting which facilitates dynamic value creation processes suggests, therefore, the need to turn to dynamic mechanisms for value appropriation in parallel

Usefullness of the ultrasonically activated scalpel in laparoscopic cholecystectomy: our experience and review of literature

Laparoscopic cholecystectomy (LC) actually represents the most used and proper treatment for gallbladder lithiasis, because its many and known advantages in comparison with ‘open’ abdominal surgery. But there are some problems during and after LC due to the use of the electric scalpel and these have brought to the search of an alternative system of dissection and coagulation. The ultrasonically activated scalpel (Harmonic Scalpel, HS) allows to perform dissection and coagulation with a minimal thermal side effect for surrounding tissues, unlike the electrocoagulation. Furthermore, the use of the HS brings a series of advantages in comparison to the other electromagnetic forms of energy (electroscalpel, laser). HS cuts and coagulates with the same effectiveness of the electroscalpel but, unlike this, it doesn't introduce risks of wandering currents. Moreover, HS contributes to have a more clean and clear (smokes-free) field of operation and it reduces the operative time, the bleeding and the costs of the operation without an increase of the complications and of the percentages of ‘open’ conversion, and perhaps leads to a less negative influence on the postoperative systemic immune response. The Authors report their experience that confirm these observations, according also with results reported in a brief review of the recent scientific literature, and support wider diffusion and technical development of this ultrasonically-operating surgical team

Dieback of Pinus nigra Seedlings Caused by a Strain of Trichoderma viride

Four different fungi (Trichoderma viride, T. harzianum, Phomopsis sp., and Mortierella sp.) were isolated from 6-year-old Pinus nigra plants showing stunting and high incidence of mortality in a reforestation area of the National Park of Abruzzo, Lazio, and Molise (central Italy). Tests conducted on P. nigra revealed the pathogenic behavior of T. viride isolates with 30 to 80% mortality in artificially inoculated 2-year-old seedlings. The pathogenicity of these isolates was also observed in 10-year-old P. nigra trees and on lemon fruit. This result, in agreement with the constant isolation of T. viride from diseased plants, suggests the possible role of this fungus in the decline of P. nigra plants. T. harzianum and two reference isolates of T. viridarium and T. trixiae did not cause any symptoms, while Phomopsis sp. and Mortierella sp. caused limited necroses around the inoculation point in a few seedlings. Their role in the decline of P. nigra seedlings was considered irrelevant. According to phylogenetic analyses, pathogenic isolates of T. viride clustered in a very uniform group containing strains from different geographic origin and hosts, but none previously reported as a biocontrol agent

EVOLUTIONARY DYNAMICS OF INTERFIRM NETWORKS: A COMPLEX SYSTEM PERSPECTIVE

This chapter aims to identify the main determinants that define the architectural properties of network emergence and significantly influence the dynamics underlying network evolution in time. The identification and analysis of these determinants, as well as the dynamic processes tied to them, allows to appreciate the competitive bases and consequences of network morphology. To this purpose, using a complex systems perspective as an integrative conceptual approach, we represent networks as complex dynamic systems of knowledge and capabilities. We perform a comparative in-depth analysis of the processes underlying the emergence and evolution of STMicroelectronic's global network and of Toyota's supplier network in the US so as to allow an elucidatory empirical assessment of the theoretical representation elaborated in the article. © 2008 Emerald Group Publishing Limited.This chapter aims to identify the main determinants that define the architectural properties of network emergence and significantly influence the dynamics underlying network evolution in time. The identification and analysis of these determinants, as well as the dynamic processes tied to them, allows to appreciate the competitive bases and consequences of network morphology. To this purpose, using a complex systems perspective as an integrative conceptual approach, we represent networks as complex dynamic systems of knowledge and capabilities.We perform a comparative in-depth analysis of the processes underlying the emergence and evolution of STMicroelectronic’s global network and of Toyota’s supplier network in the US so as to allow an elucidatory empirical assessment of the theoretical representation elaborated in the article

The origin of strong ties: The role of weak ties in the emergence and evolution of alliance networks

Interorganizational ties are distinguished into strong and weak on the basis of their strength. By focusing mainly on strong alliances ties, previous research has fallen short to explain the role of weak ties among organizations for the evolution of alliance networks. With the aim of scrutinizing the role of weak ties in the establishment, maintaining, and transforming of alliance ties, we develop a conceptual framework that looks at networks of interorganizational weak ties as conduits for the dissemination of information about (valuable) knowledge sets that supports the processes of opportunity discovery and/or creation. The exploitation of the discovered or created opportunities leads to the activation of strong alliance ties and, hence, feeds into the evolution of alliance networks\u2019 structure