Integrated geophysical methods applied to some archaeological sites of North Sardinia

This study deals with the employment of a multimethod geophysical survey, electrical (Electrical Resistivity Tomography) and electromagnetical (Ground Penetrating Radar) carried out on two archaeological sites near shore archaeological sites. For this purpose the settlements of Sant'Imbenia (Alghero, SS) and Santa Filitica (Sorso, SS), two Roman villas located in northern Sardinia were considered. The focus of the paper is to assess as the geophysical response of different instruments might be impacted by different moisture conditions and archaeological contexts. The electromagnetic surveys were conducted in reflection mode, using a monostatic GPR, working simultaneously by two transmitters (frequency of 200 and 600 MHz) and two receivers, while the electrical surveying was conducted with a Terrameter SAS 1000 device combined with ES 10-64 electrode selector. The 2D and 3D high-resolution models revealed a distribution of shallow anomalies that indicate the presence of buried structures (walls and filled cavities) in the surveyed areas. A comparison of the results was made, checking the relative merits and demerits of the different techniques in the two coastal archaeological sites. The integration of geophysical methods has provided useful information to design a more efficient plan for further archaeological excavations

Prunus Knotted-like genes. Genome-wide analysis, transcriptional response to Cytokinin in micropropagation, and rootstock transformation

Knotted1-like homeobox (KNOX) transcription factors are involved in plant development, playing complex roles in aerial organs. As Prunus species include important fruit tree crops of Italy, an exhaustive investigation of KNOX genes was performed using genomic and RNA-seq meta-analyses. Micropropagation is an essential technology for rootstock multiplication; hence, we investigated KNOX transcriptional behavior upon increasing 6-benzylaminopurine (BA) doses and the effects on GF677 propagules. Moreover, gene function in Prunus spp. was assessed by Gisela 6 rootstock transformation using fluorescence and peach KNOX transgenes. Based on ten Prunus spp., KNOX proteins fit into I-II-M classes named after Arabidopsis. Gene number, class member distribution, and chromosome positions were maintained, and exceptions supported the diversification of Prunus from Cerasus subgenera, and that of Armeniaca from the other sections within Prunus. Cytokinin (CK) cis-elements occurred in peach and almond KNOX promoters, suggesting a BA regulatory role in GF677 shoot multiplication as confirmed by KNOX expression variation dependent on dose, time, and interaction. The tripled BA concentration exacerbated stress, altered CK perception genes, and modified KNOX transcriptions, which are proposed to concur in in vitro anomalies. Finally, Gisela 6 transformation efficiency varied (2.6-0.6%) with the genetic construct, with 35S:GFP being more stable than 35S:KNOPE1 lines, which showed leaf modification typical of KNOX overexpression

Plant Cellular and Molecular Biotechnology: Following Mariotti's Steps

This review is dedicated to the memory of Prof. Domenico Mariotti, who significantly contributed to establishing the Italian research community in Agricultural Genetics and carried out the first experiments of Agrobacterium-mediated plant genetic transformation and regeneration in Italy during the 1980s. Following his scientific interests as guiding principles, this review summarizes the recent advances obtained in plant biotechnology and fundamental research aiming to: (i) Exploit in vitro plant cell and tissue cultures to induce genetic variability and to produce useful metabolites; (ii) gain new insights into the biochemical function of Agrobacterium rhizogenes rol genes and their application to metabolite production, fruit tree transformation, and reverse genetics; (iii) improve genetic transformation in legume species, most of them recalcitrant to regeneration; (iv) untangle the potential of KNOTTED1-like homeobox (KNOX) transcription factors in plant morphogenesis as key regulators of hormonal homeostasis; and (v) elucidate the molecular mechanisms of the transition from juvenility to the adult phase in Prunus tree species

Peach [Prunus persica (L.) Batsch] KNOPE1, a class 1 KNOX orthologue to Arabidopsis BREVIPEDICELLUS/KNAT1, is misexpressed during hyperplasia of leaf curl disease

Class 1 KNOTTED-like (KNOX) transcription factors control cell meristematic identity. An investigation was carried out to determine whether they maintain this function in peach plants and might act in leaf curliness caused by the ascomycete Taphrina deformans. KNOPE1 function was assessed by overexpression in Arabidopsis and by yeast two-hybrid assays with Arabidopsis BELL proteins. Subsequently, KNOPE1 mRNA and zeatin localization was monitored during leaf curl disease. KNOPE1 and Arabidopsis BREVIPEDICELLUS (BP) proteins fell into the same phyletic group and recognized the same BELL factors. 35S:KNOPE1 Arabidopsis lines exhibited altered traits resembling those of BP-overexpressing lines. In peach shoot apical meristem, KNOPE1 was expressed in the peripheral and central zones but not in leaf primordia, identically to the BP expression pattern. These results strongly suggest that KNOPE1 must be down-regulated for leaf initiation and that it can control cell meristem identity equally as well as all class 1 KNOX genes. Leaves attacked by T. deformans share histological alterations with class 1 KNOX-overexpressing leaves, including cell proliferation and loss of cell differentiation. Both KNOPE1 and a cytokinin synthesis ISOPENTENYLTRANSFERASE gene were found to be up-regulated in infected curled leaves. At early disease stages, KNOPE1 was uniquely triggered in the palisade cells interacting with subepidermal mycelium, while zeatin vascular localization was unaltered compared with healthy leaves. Subsequently, when mycelium colonization and asci development occurred, both KNOPE1 and zeatin signals were scattered in sectors of cell disorders. These results suggest that KNOPE1 misexpression and de novo zeatin synthesis of host origin might participate in hyperplasia of leaf curl disease

Insights into the Sesquiterpenoid Pathway by Metabolic Profiling and De novo Transcriptome Assembly of Stem-Chicory (Cichorium intybus Cultigroup "Catalogna")

Stem-chicory of the "Catalogna" group is a vegetable consumed for bitter-flavored stems. Type and levels of bitter sesquiterpene lactones (STLs) participate in conferring bitterness in vegetables. The content of lactucin-and lactucopocrin-like STLs was higher in "Molfettese" than "Galatina" landrace stalks, regardless of the cultivation sites, consistently with bitterness scores and gustative differences. The "Galatina" transcriptome assembly resulted in 58,872 unigenes, 77% of which were annotated, paving the way to molecular investigation of the STL pathway. Comparative transcriptome analysis allowed the identification of 69,352 SNPs and of 1640 differentially expressed genes that maintained the pattern independently of the site. Enrichment analyses revealed that 4 out of 29 unigenes were up-regulated in "Molfettese" vs "Galatina" within the sesquiterpenoid pathway. The expression of two germacrene A -synthase (GAS) and one -oxidase (GAO) genes of the costunolide branch correlated positively with the contents of lactucin-like molecules, supporting that STL biosynthesis regulation occurs at the transcriptional level. Finally, 46 genes encoding transcription factors (TFs) maintained a differential expression pattern between the two varieties regardless of the growth site; correlation analyses among TFs, GAS, GAO gene expressions and STLs contents suggest that one MYB and one bHLH may act in the pathway

NMR-Metabolic Methodology in the Study of GM Foods

The 1H-NMR methodology used in the study of genetically modified (GM) foods is discussed. Transgenic lettuce (Lactuca sativa cv "Luxor") over-expressing the ArabidopsisKNAT1 gene is presented as a case study. Twenty-two water-soluble metabolites (amino acids, organic acids, sugars) present in leaves of conventional and GM lettuce were monitored by NMR and quantified at two developmental stages. The NMR spectra did not reveal any difference in metabolite composition between the GM lettuce and the wild type counterpart. Statistical analyses of metabolite variables highlighted metabolism variation as a function of leaf development as well as the transgene. A main effect of the transgene was in altering sugar metabolism

A Strawberry KNOX Gene Regulates Leaf, Flower and Meristem Architecture

The KNOTTED-LIKE HOMEODOMAIN (KNOX) genes play a central role in maintenance of the shoot apical meristem. They also contribute to the morphology of simple and compound leaves. In this report we characterize the FaKNOX1 gene from strawberry (Fragaria spp.) and demonstrate its function in trasgenic plants. The FaKNOX1 cDNA was isolated from a cultivated strawberry (F.×ananassa) flower EST library. The sequence is most similar to Class I KNOX genes, and was mapped to linkage group VI of the diploid strawberry genome. Unlike most KNOX genes studied, steady-state transcript levels were highest in flowers and fruits. Transcripts were also detected in emerging leaf primordia and the apical dome. Transgenic strawberry plants suppressing or overexpressing FaKNOX1 exhibited conspicuous changes in plant form. The FaKNOX1 RNAi plants presented a dwarfed phenotype with deeply serrated leaflets and exaggerated petiolules. They also exhibited a high level of cellular disorganization of the shoot apical meristem and leaves. Overexpression of FaKNOX1 caused dwarfed stature with wrinkled leaves. These gain- and loss-of-function assays in strawberry functionally demonstrate the contributions of a KNOX domain protein in a rosaceous species

Structure-property relationships in as-fabricated and emergency repair welds in service-exposed 2.25Cr-1Mo pressure vessel steel

Repair rather than replacement of pressure vessel components operating at elevated temperatures is becoming a far more viable option, with welding being used increasingly for repair, replacement, retrofits and modifications. However, the considerable cost and time involved in performing conventional post weld heattreatment (PWHT) is increasingly forcing utility owners to turn toward other alternatives, such as cold weld repairs. These require no PWHT and rely on a controlled deposition process – precise weld bead placement and heat inputs to achieve tempering of the HAZ. One such cold weld repair was applied to a prematurely failed reheater outlet header (RHOH) in an emergency situation, enabling its return to service until a replacement component was available. Investigation of this particular repair constitutes a core component of this thesis. Much of the research that has been conducted to justify cold repair techniques has used accelerated high temperature creep testing to demonstrate their integrity. How well this testing reflects real-life performance of repaired components remains uncertain. However, the present study provided a rare opportunity to evaluate the effects of service exposure on the performance of an emergency cold weld repair, as well as to examine the effectiveness of accelerated laboratory creep testing on creep life predictions for the repair weld, the original fabrication welds and the service exposed parent metal. The metallurgical and mechanical properties of the service-exposed non-PWHT temper bead (TB) repair weld were analysed and characterised systematically relative to both the service-exposed original fabrication weld and parent metal. All test specimens were machined transverse to the welding direction, from 20 mm thick slices taken from both the TB repair and original fabrication weldments. The mechanical property characterisation involved hot tensile (miniature sample), Charpy V-notch impact, hardness and accelerated creep-rupture testing. The microstructural characterisation consisted of compositional analysis, surface replication and conventional metallography, post-test fractography, high-resolution microscopy (SEM, TEM and EBSD), EDS and dilatometry. The microstructural studies were successful in characterising the service-exposed TB repair weld metal both in the as-received and post-test conditions. The findings generally showed the TB repair weld metal microstructure was significantly different from those of the parent and fabrication weld metals. This was established by the TEM and EBSD studies which showed finer carbides, higher dislocation density and limited subgrain formation, features which are consistent with structure of high stored strain energy. The finer carbides, significant Fe content of some carbides and the presence of Mo-rich carbides are also consistent with a relatively early stage in the carbide evolution sequence for this steel. Additionally, the non-metallic inclusions, which are generally considered to be deleterious to properties, were fine scale and uniform in size distribution. These microstructural characteristics were reflected in superior mechanical properties for all tests, with the notable exception of creep performance. In terms of creep resistance, weld repairs of this kind install a high energy microstructure (finer carbides, higher dislocation density, fine grain structure and subgrain / cell structure) into significantly creep degraded material and generate sharp gradients in microstructure and properties. Overall, the microstructural observations in the service-aged condition and the mechanical properties determined by the experimental work were found to support the conclusion that the ex-service material had clearly not exhausted its creep service-life. This was proven by simulating further service life using accelerated creep testing. During these experiments, the creep failure mode was found to be ductile fracture induced by micro-void coalescence. The tests indicated that although the predicted creep life of the TB repair weldment was inferior to the aged parent metal, it was slightly higher than that of the service-exposed fabrication weldment. It is therefore concluded that the TB repair weld and its associated HAZ did not compromise the overall weldment integrity. This conclusion is drawn despite the finding that the accelerated creep test data for the repair weld showed sub-normal creep performance relative to NT samples and even the aged parent metal. This outcome is probably due to the “accelerated” test conditions which induced structural changes that are unlikely to occur under the actual service conditions. Therefore, accelerated creep test data should be treated with circumspection, particularly for structures such as cold repair weld metal which are characterised by high stored strain energy. The instability of this kind of structure in relation to restoration processes (at the “accelerated” temperatures used for testing) is likely to produce premature creep failure and result in a highly conservative creep life assessment. The perceived danger of cold repair welding is that the vessel integrity will be impaired by the absence of a PWHT to reduce internal stresses, liberate hydrogen and improve mechanical properties. However, the evidence obtained in this study indicates that this need not be the case. Therefore, it is concluded that the TB weld technique can be successfully applied to high energy piping (HEP) components without the need for PWHT. The results of the investigation provide new insights into the microstructure and properties, particularly the creep performance, of service-aged cold repair welds. The research has also revealed a serious limitation of accelerated creep testing of weld repair structures of this kind, in that dynamic restoration processes can be induced that are unlikely to occur at the lower service operating temperatures and stresses

La sicurezza nei luoghi di lavoro:il caso Saint Gobain Glass dello stabilimento di Pisa

Questa tesi si propone di illustrate il tema della sicurezza nei luoghi di lavoro, uno strumento molto importante per la salute dei lavoratori ma ancora purtroppo non implementato in tutte le realtà aziendali. Viene data molta attenzione al ruolo della formazione come strumento indispensabile per formare “una coscienza della sicurezza”. La tesi è strutturata in una prima parte generale dove si analizza l’evoluzione nel tempo della sicurezza, i sistemi di gestione della sicurezza, le misure di prevenzione e protezione, la formazione del personale e il benessere organizzativo, la seconda parte è riferita ad un caso pratico dove la sicurezza è ben implementata. Si tratta di una azienda multinazionale, la Saint Gobain Glass dello stabilimento di Pisa.Viene fatta una breve storia sulla nascita di questa azienda, come si è ampliata nel tempo e quindi viene analizzato il sistema di gestione della sicurezza e relative metodologie utilizzate, facendo anche specifico riferimento agli standard emanati dalla casa madre di Parigi