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Eco-ethological characterisation of the alien species vinous-throated parrotbill (Paradoxornis webbianus) and evaluation of its effects on indigenous species.
No full textThe phenomenon of exotic species (or alien) species introduction is increased in the last few years, closely connected to the increment in human activities on the global scale. In spite of the high number of introduced organisms, only few of them succeed in establishing a new range and become naturalised, that is establish self-sustaining populations. Then, only a small part of naturalised species can become an invasive species and a threat to biological diversity. There are many reasons inducing a demographic explosion of these species, in particular the lack of limiting factors such as competitors and predators presence and also the introduced species characteristics, themselves such as population growth rate, or migratory strategy can cause invasiveness.
The impact and cost of biological invasions are global and enormous, in both ecological (for example native species extinction, ecosystem alteration) and economic terms. In fact, biological invasions are the second threat to biodiversity after habitat destruction.
Parrotbills (Paradoxornis webbianus), Chinese Passeriformes, were introduced in Varese Province, north-western Italy, in 1995 by an animal trader that introduced 150 animals. In the same year these birds were found in Brabbia Marsh Natural Reserve, on southern side of Lake Varese.
The expansion of this species has been confirmed from frequent sightings since 2003 in other province areas, like Lake Comabbio, Besozzo and Bagnoli Valley, south-east of Brabbia Marsh.
Following the major international nature protection directive exhortations we carried out a multiple scale approach to study genetics and auto-ecology of this species and to understand its impact on indigenous species. In particular, the aims of this project were: to define the present species distribution, to develop knowledge on parrotbill auto-ecology, and to evaluate the potential competition with other species, evaluating parrotbill invasiveness.
We carried out 5 censuses from February 2006 to February 2008, to establish species expansion that reconfirmed the 2003 presence areas. Moreover, the area occupied by parrotbills presents several ecological corridors that can lead to an eventual future expansion.
Parrotbill were caught using mist-nets during bird ringing seasons in the Brabbia Marsh Ornithological Station. During the bird ringing operations we caught once 367 animals and 318 other animal were instead caught more than one time, for a total of 685 animals caught.
Number of caught parrotbills varied during the years, following meteorological events: in fact, population decreased after winters with high snow abundance. Using the Schnabel and the Burnham and Overton methods we calculated population size estimates. The two methods gave different results, in particular the Burnham and Overton method overrated population estimate if compared with Schnabel, but we can estimate a population between 350 to 3500 animals in Brabbia Marsh reserve.
We monitored 19 animals during different periods of the year with radio tracking technique using tags (BD-2N, Holohil Ltd, Ontario, Canada) weighing 0.43 g. Home range dimensions vary from less than an hectare (0.2-1.3 ha) in the reproductive season, to 35 hectares (20- 35 ha) in winter season, with intermediate situations during autumn, when dimension range was wider (9.5-47.5 ha). Differences in home range dimensions were statistically significant (ANOVA F (2,16) =8.9291 P= 0.003) and moreover this result is in accordance to the home range dimensions registered in the area of origin.
To analyse habitats present in the home range we used two different methods, in particular Compositional Analysis and Ivlev’s electivity index. In both cases emerged that parrotbills prefer wetland areas, in particular grey willow shrub, marsh areas.
To study parrotbills environmental perception in terms of scale we used program FRACTAL to analyse movement patterns derived from radio tracking data. The analysis of variance shows that the parrotbill spatial perception increases with scale (ANOVA F(1,476)=247.65 P<0.001) and changes with seasons (ANOVA F(2,475)=8.3953 P=0.0003). These results indicate that the potential dispersal season is during autumn, when parrotbills show a broader spatial scale perception.
To understand species auto-ecology we analysed parrotbills diet using faecal samples collected during the ringing bird sessions. Diet composition changes during the year, in particular proportion of vegetal items increased from spring to winter (ANOVA F(3,174) =142.77 P<0.001). Diet is composed in particular by Ichneumonidae, Chrysomeloidea, Carabidae, Scarabaeoidea and Araneidae. The vegetable part is composed by ate elder (Sambucus nigra), pokeweeds (Phytolacca sp.) and seeds of common reed (Phragmites australis).
We also compared the parrotbills diet with trophic spectra of 10 indigenous species using the Proportional Similarity Index the Pianka’s Overlap Index. Both methods gave similar results, the parrotbill diet resulting similar to the diet of all species considered, and the most similar
species resulted are the reed warbler (Acrocephalus scirpaceus) (PSI: 0.43; OI:0.61) and the reed bunting (Emberiza schoeniclus) (PSI: 0.34; OI:0.52).
Species invasiveness was estimated according to the “Risk assessment models for establishment of exotic vertebrates in Australia and New Zealand”. Considering all factors of this decision support model, the parrotbill invasivity risk is classified as Serious, in accordance to the Vertebrate Pest Committee of Australia.
All these results, connected with other species characteristics (generalism, large geographic original range, monogamy, monomorphic, social foraging, and non migratory strategy) suggest that the parrotbill, even if it is not yet an invasive species in our zone, could become a pest in the future
Caratterizzazione molecolare di gp120 di HIV-1 e loro espressione su particelle simil virali (VLPs) come modello di presentazione antigenica.
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Representing business processes: conceptual model and design methodology.
No full textIn this work we present our contributions to business processes modeling. Namely, we have undertaken a thorough analysis of the OMG standard BPMN, along with other related technologies like WS-BPEL and XPDL. Such analysis has pointed out several weaknesses that motivate our contributions. We propose a new conceptual model of BPMN called BPeX as a clear and principled way to represent and reason about business processes. We provide a three-phase design methodology to model business processes focusing on BPMN and we introduce the notion of business process normal form. We introduce also the concept of business process views and apply them to business processes access control. Finally, we provide an extension to BPMN with privacy policies. Relevant parts of BPMN conceptual model will be included as part of the forthcoming BPMN 2.0 standard
Sintesi di eterocicli a scheletro indolitico mediante reazioni di anellazione di nitrosoareni e alchini.
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Modificazione superficiale di materiali tessili con biossido di titanio nanostrutturato.
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Chemical-physical characterization of colloids for chemical mechanical planarization processes of semiconductor devices.
No full textCMP (Chemical Mechanical Planarization) is one of the most expensive processes in the semiconductor industry, and about 70% of its cost can be ascribed to the consumption of the slurry employed during the process; such aqueous suspensions typically contain concentrated oxidizing chemicals and colloidal particles mechanically active on the wafers.
In order to reduce costs of ownership, the dilution of standard commercial fumed WCMP slurries with de-ionized water (in 1:1 ratio) is a common procedure used by many semiconductor manufacturers; such dilution leaves process parameters practically unaffected, requiring only minor adjustments of velocity and polishing pressures. Differently, simple dilutions at higher ratios have shown a number of problems, such as decrease in removal rate, process instability and low reliability on the devices, that make this procedure not economically sustainable.
Therefore, the need for cheaper CMP processes imposes the development of slurry modifications with additives different than water, which are intrinsically cheap, non-toxic and not harmful to the whole process and to the product quality.
This work begins (Chapter 1) with a brief description of the CMP process, introducing process parameters, consumables and the mechanisms of planarization, with a special focus given to metal (tungsten) CMP processes.
Then, in Chapter 2, the cost of ownership of the process is analyzed, detailing the effects of dilution.
Chapter 3 describes all the physico-chemical techniques used for the analysis of the four chosen WCMP slurries, to which the following chapters (from Chapter 4 to Chapter 7) are dedicated. A single chapter is dedicated to the analyses and results of each slurry.
Chapter 8 summarizes the results of the analyses, reporting and comparing the determined composition of the slurries. Slurries labeled as A and C are chosen as the most interesting ones, and following analyses focus on them. The effects of dilution on ions concentration and pH are considered, and the effects on - potential are described.
In Chapter 9 the interaction between slurry and wafer is considered. A first part of the chapter is dedicated to the morphological analysis of the surface of tungsten after contact with slurry. The rest of the chapter deals with CMP processed wafers, starting with the analysis of removal rate on wafers with no defined pattern or morphology varying chemical properties of the slurry. The last part of the chapter reports and compares the results obtained on patterned wafers, including recession of tungsten in silicon oxide, defect density and electrical yield.
Electrochemical analysis of tungsten in slurry is introduced in Chapter 10. Values of corrosion current and potential are determined, and correlated with varying pH and with removal rate on tungsten wafers.
A final chapter (Chapter 11) is dedicated to summarize the conclusions of this work.
Appendix A details the X-ray powder diffraction characterization of di-silver trihydrogen para periodate. A compound not strictly related, but found during this work.
Appendix B and C contain the posters and papers presented and published during this work
Molecular mechanisms of novel angiopreventive compounds.
No full textIn this thesis I have been studied 2 agents that have shown promising results as cancer chemopreventive.
These 2 compounds are:
-N-acetyl-cysteine (NAC)
-Triterpenoid CDDO-Me (synthetic derived of olanoleic acid)
NAC has been widely studied and has already been reported is chemopreventive activity due to its anti-oxidant activity. Here for the first time it has been reported its ability to reduce the expression of an endothelial membrane protein (E-selectin).
E-selectin is expressed on endothelial cells and can be used by metastatic cells as ‘docking site’ during metastatic spreading. This proprety of NAC could be a suitable tool for preventive approach of metastatization. CDDO-Me is actually in phase I Clinical trial. It has already been reported its antitumoral proprety. Here we show for the first time its potent antiangiogenic and angiopreventive activity through its interaction with inflammatory and endothelial cells
The role of innate immunity in tumor angiogenesis: identification of downstream mediators in the IL-12 mediated anti-angiogenic activity of Angiostatin.
No full textThe numerous studies on Angiostatin (AST) mechanisms of angiogenesis inhibition have focused on the potential receptor-mediated interactions with endothelial cells. Although these studies have provided potential mechanisms, no single receptor system has been definitively shown to mediate AST activity. Recent studies have shown that inflammatory cells, in particular macrophages and neutrophils, are also targets of AST. These cells are part of a network that generates one of the most powerful anti-angiogenic cytokines: interleukin-12 (IL-12). We show that in in vivo preclinical studies, IL-12 is an essential mediator of AST antiangiogenic activity. Function blocking antibodies to IL-12 revert angiogenesis inhibition induced by AST. Further, AST is unable to exert angiogenesis inhibition in mice with gene targeted deletions of the IL-12 receptor IL-12R2, specific for IL-12, or in mice gene targeted for the IL- 12 p40 subunit. However, AST retains anti-angiogenic activity in IFNgene targeted mice, suggesting an IFNindependent angiogenesis inhibition mechanism as previously observed. We also identified a short synthetic peptide localized to the lysine binding domain that completely reproduces the IL-12 dependent anti-angiogenic properties of AST. Since endothelial cells do not express the IL-12 receptor, nor do they essentially change gene expression patterns when treated with AST in vitro, our data show that the immune system forms an integral part of the anti-angiogenic effects of AST, by both responding to AST and providing downstream signals to the endothelium. AST induced IL-12 synthesis by human macrophages polarized toward M1 phenotype in vitro. We also identified a short synthetic peptide with potential application in oncological therapy, that reproduced the IL-12 dependent anti-angiogenic properties of angiostatin