375 research outputs found
Identificazione e caratterizzazione di geni coinvolti nel processo di abscissione in frutti di melo (Malus domestica L. Borkh)
No full textMany fruit species bear an abundance of flowers producing a surplus of fruits that the tree is unable to support. In anticipation of this, the major fruit species developed an immature fruit (fruitlet) physiological drop as a self-regulatory mechanism. This process is, at least in part, a consequence of the competition among fruits and between fruits and shoots for carbon assimilates. The self-regulatory mechanism responsible for the immature apple fruit shedding may be magnified by chemicals such as naphthaleneacetic acid (NAA) and its amide (NAD), and benzylaminopurine (BA) sprayed within 5-6 weeks after full bloom. The thinning action of bioregulators is quite variable and depends on environmental conditions and genotypes. In apple, there are varieties easy to thin and others difficult even though different chemicals or combinations of them are used. Understanding the molecular mechanisms and processes involved in abscission might help in finding new approaches and new chemical thinners to control abscission in fruit, or new self-thinning varieties.
The described research was aimed to elucidate the molecular events underlying the in planta fruitlet abscission, taking into account the characteristics of this system and the practical importance of thinning in apple.
Fruit drop is due to the activation of specific abscission zones (AZs). It is accepted that abscission is a highly regulated developmental process that is both influenced and activated in response to internal cues and/or environmental conditions. Nevertheless, the identity of the signals responsible for the activation of the AZ is as yet unknown. Among phytohormones, ethylene enhances abscission in several species and systems as well as in apple, while auxins produced by seeds are thought to desensitize AZs to ethylene and prevent abscission. In apple trees, the fruitlet physiological drop is due to the activation of the AZ located at the junction of the peduncle into the twig. In this region four lateral (LF) and one central (CF) fruitlets and the shoot are inserted. The CF comes from the pollinated king flower (KF) that, since it blooms earlier within the cluster, originates a fruitlet larger than the lateral ones. During the physiological drop, the shoot at cluster side, is thought to be a sink in competition with fruitlets for assimilate supply. Considering that seeds and/or fruits are involved in determining the shedding signal while the morphogenetic response occurs always at the AZ level, it is crucial to analyse the whole fruitlet system involved in abscission that should include concurrently seed, cortex, peduncle, and AZ. It is generally believed that the interaction between ethylene and auxin plays a major regulatory role in abscission. Starting from this, a mass gene approach was used in this work to identify genes regulating or involved in abscission. The cDNA-AFLP technique was adopted for transcriptional profiling of differentially expressed genes during apple fruitlet abscission. This allowed the isolation of 278 differential clones by comparing expression profiles of abscising (AF) versus non-abscising (NAF) fruitlet populations. AFs were obtained from lateral fruitlets of trees sprayed with benzylaminopurine (BA) at 200 ppm, 17 days after petal fall (APF) when the fruit cross diameter was about 10-12 mm. NAF originated from central flowers grown in clusters where all the lateral flowers had been removed at bloom.
All ESTs (expressed sequence tags) obtained have been annotated with the Gene Ontology vocabulary and grouped according to cellular components, biological processes and molecular functions. Considering the cellular components, the most affected genes in the cortex were related to mitochondrion, plastid and membranes. Concerning the molecular functions, the mostly affected ones were the binding and the transferase activities in the cortex, the hydrolase and transport activities in the seed, and the binding activity in the peduncle. Considering the biological process, in the cortex the most abundant genes were those controlling transport, protein and carbohydrate metabolism. As a general remark, taking into account all the three ontology criteria, it appeared that a prominent up-regulation occurred in the seed. This might be consistent with the determinant role attributed to the seed in the regulation of fruit abscission.
The expression and functional analyses of the most interesting clones were carried out by semiquantitative RT-PCR on agarose gel on cDNA obtained from seeds, cortex, peduncles and AZs of AFs and NAFs.
Expression analyses confirmed the efficacy of the cDNA-AFLP approach to find a large amount of differentially expressed ESTs and the involvement of the studied genes in regulating the abscission and senescence processes. In particular the differential expression of sugar-metabolism and signalling related genes confirmed the importance of carbohydrates, together with hormones, in controlling the induction of AZs.
Since functional studies through silencing or overexpression approaches cannot be easily performed on trees, additional experiments were carried out in Arabidopsis thaliana to investigate the participation of these and other genes in abscission. To this end, Arabidopsis genes putatively homologous to those differentially expressed in relation to fruitlet abscission in apple were identified. A dual approach was chosen to study their function in abscission. In a first attempt, insertional (T-DNA) homozygous mutants were obtained and scored for the presence of abscission-related phenotypes. Probably due to gene redundancy, no phenotypes were detected. Therefore, expression analyses were carried out on the same genes with real time RT-PCR on abscission zones of known Arabidopsis mutants with delayed (dab4-1, dab5-1) or no petal abscission (ida). The results showed a different pattern of expression in comparison to that found in wild type and confirmed an involvement of these genes in abscission. Current work is devoted to further characterise the putative role played by these genes in regulating the abscission of flower organs in Arabidopsis. In addition, a "systematic" approach for the analysis of the whole apple fruitlet abscission transcriptome is needed. To this end an apple microarray is being developed from the large number of already available ESTs, to be used for screening of new chemical thinners and for marker assisted selection of self thinning genotypes
Título: In estravag. volentes, Frederici, ac in estravag. si aliquem, Iacobi, Siciliac Regum, enarrationes perspicuae
No full textMarca tip. en port. e na última pSign.: a, b-d, A-Q, R, S-Z, 2A-2D, 2E, 2F-2G, 2HTexto a dúas co
Angelo Biancini. Senza titolo
No full textNella scheda viene brevemente ripercorsa la biografia di Angelo Biancini, commentando criticamente l'opera alla luce della più aggiornata bibliografi
Late Cretaceous high trochospiral rotaliid foraminifera from Italy
No full textHigh trochospiral architecture is relatively uncommon in rotaliid foraminifera as it is observed in a few
species throughout the stratigraphic record of their 100 My history. Such a feature is recorded within the
lockhartiniid group, for example in the Paleogene genus Sakesaria, whereas it is not reported from the
Cretaceous. We describe two new Late Cretaceous species, Extentaspira pichezziae gen. nov., sp. nov. and
Extentaspira pampaloniae sp. nov., displaying high trochospiral test, from the shallow-water facies of the
Apennine and Adriatic carbonates platforms of Central and Northeastern Italy. Besides the absence of
dimorphism, high trochospiral test architecture suggests an adaptation to an infaunal lifestyle. These
occurrences may provide further evidence on the paleo-biogeographic gradient with the nearby Late
Cretaceous Pyrenean gulf
Linking governance to strategy: the role of the Finance Organization
No full textThe capabilities, skills, and responsibilities required of finance professionals have changed significantly over the last
decade. No longer limited to tracking financial results and rigorous financial reporting, finance experts are increasingly
required to support strategic decision making, operation efficiency, and value creation and to combine solid
accounting skills with knowledge of the business, leadership abilities, and management expertise. And such capabilities
still aren’t enough.
In 2002, the Sarbanes-Oxley Act (SOX) in the U.S. directly impacted the finance organization (and the CFO) by
introducing new responsibilities for the trustworthiness and reliability of financial reports (Section 302) and new
requirements for internal controls (Section 404). Such emerging issues and new responsibilities call for a redefinition
of the role of the finance organization in the governance process. Using the case of GE Oil & Gas, we suggest that
finance professionals can be much more directly involved within the corporate governance framework by playing an
active role in translating governance principles into strategic decision making and strategic performance management
systems. Although we include examples from GE Oil & Gas to build our argument, many of the issues we discuss
are relevant and applicable for the entire GE organization
Icacinicaryites sp. Del Rio C. & De Franceschi 2020
No full textIcacinicaryites sp. (Fig. 5) STRATIGRAPHY. — Cuisian. LOCALITY. — Prémontré (France). SPECIMEN. — MNHN.F.44741. DESCRIPTION Fossil bilaterally symmetrical, elliptical; unilocular and singleseeded, length 8.8 mm, width 7.6 mm. Apex slightly asymmetrical, base rounded, symmetrical. Outer part of locule cast with reticulate pattern of rounded ridges; face of locule cast with 3-4 longitudinal ridges enclosing 6-9 polygonal areoles on each lateral face with few or no freely ending ridgelets; a keel surrounds the locule cast in the plane of symmetry (ṙ); cellular details unknown. REMARKS Only one specimen represents the Icacinaceae in this outcrop. We found no thicker part on the keel which suggests that this specimen is a locule cast rather than the complete endocarp. In the absence of apparent anatomical preservation, we choose to include this specimen in the genus Icacinicaryites without species name. This specimen could be close to Iodes multireticulata sensu Reid & Chandler (1933) but with fewer areoles. It may correspond to Iodes rigida from Le Quesnoy site, but the reticulation pattern does not match. This specimen seems to have a unique morphology despite the lack of anatomical characters. OVERVIEW OF ICACINACEAE FROM THE PARIS BASIN Here we review all the accepted occurrences of the Icacinaceae from the Paris Basin (Table 1). In addition to fruits from Passy, Belleu and Prémontré studied here, we include the fruits from Rivecourt (Paleocene; Del Rio et al. 2019a) and Le Quesnoy (early Eocene, Del Rio et al. 2019b) and a flower from Le Quesnoy (Del Rio et al. 2017). Occurrences of triporate and echinate pollen belonging to the Compositoipollenites genus (with Icacinaceous affinity) have been described for the Paris Basin. Compositoipollenites medius Krutzch & Vanhoorne, 1977, Compositoipollenites minimus Krutzch & Vanhoorne, 1977 and Compositoipollenites rhizophorus burghasungensis (Murriger & Pflug, 1952) Thomson & Pflug, 1949 were found in the Le Quesnoy site and the Paleocene of Guitrancourt (Cavagnetto 2000, Kedves 1970). Moreover, Compositoipollenites minimus was also found in Nointel (early Eocene, Oise; see Kedves 1970) and Compositoipollenites rhizophorus (R. Potonié, 1934) R. Potonié, 1960 at Paris Austerlitz (late Eocene, Paris; see Kedves 1970). However, some author consider that we have not enough data from other families that also have echinate pollen to confidentially conclude about these affinities (Manchester et al. 2015). We decided to follow the same caution and we do not include them in our analysis. No leaves or woods remains have been attributed to Icacinaceae in the Paris Basin.Published as part of Rio, Cédric Del & Franceschi, Dario De, 2020, Icacinaceae fossil fruits from three sites of the Paris Basin (early Eocene, France): local diversity and global biogeographic implications, pp. 17-28 in Geodiversitas 42 (2) on page 25, DOI: 10.5252/geodiversitas2020v42a2, http://zenodo.org/record/369691
Apuntes para una “etnografía centrada en la persona” con los wichís del Chaco argentino
No full textThe paper proposes, on the one hand, a reflection on the anthropological methodology. It analyzes how the disciplinary paradigm and research practices neither encourage nor require a systematic clarification of the implicit methodology. On the other hand, the prerogatives of the biographical method are presented, which allows for a sensitive ethnography that tries to be particularly attentive to the “person” factor. Finally, some testimonies of current Wichís women from Misión Nueva Pompeya in the Argentinian Chaco are introduced. These stories were mainly told in Spanish and one of them was translated from the Wichí by the author itself with a young Wichi student. In these testimonies, the protagonists reflect on the meaning of some verbal expressions, propose notional translations, and explain their contexts of use.The paper proposes, on the one hand, a reflection on the anthropological methodology. It analyzes how the disciplinary paradigm and research practices neither encourage nor require a systematic clarification of the implicit methodology. On the other hand, the prerogatives of the biographical method are presented, which allows for a sensitive ethnography that tries to be particularly attentive to the “person” factor. Finally, some testimonies of current Wichís women from Misión Nueva Pompeya in the Argentinian Chaco are introduced. These stories were mainly told in Spanish and one of them was translated from the Wichí by the author itself with a young Wichi student. In these testimonies, the protagonists reflect on the meaning of some verbal expressions, propose notional translations, and explain their contexts of use
D. Amram, Standards to Face Children and Patients Digital Vulnerabilities, in C. Crea - A. De Franceschi (eds), The New Shapes of Digital Vulnerability in European Private Law, Nomos, 2024, pp. 439-467
No full textThe Author describes how the digital transition is impacting on the concept of vulnerability, taking into account the roles of standards to protect patients and children
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