323,836 research outputs found
Is inequality in Africa really different ?
No full textHigh inequality in Africa is something of a paradox: Africa should be a low-inequality continent according to the Kuznets hypothesis (because African countries are poor and agriculture-based), and also because land (the main asset) is widely shared. The author's hypothesis is that African inequality is politically determined. Yet in the empirical analysis, despite the introduction of several political variables, there is still an inequality-increasing"Africa effect"linked to ethnic fractionalization. The politics, however, may work through ethnic fractionalization, which provides an easy and secure basis for the formation of political groups. Although this is a plausible explanation, it is not fully satisfactory, and the author criticizes it in the concluding section.Services&Transfers to Poor,Earth Sciences&GIS,Economic Theory&Research,Poverty Impact Evaluation,Human Rights,Inequality,Poverty Impact Evaluation,Governance Indicators,Earth Sciences&GIS,Services&Transfers to Poor
Study of microbial diversity and yeast interactions using molecular methods
No full textI microrganismi svolgono un ruolo fondamentale nella regolazione dei vari ecosistemi, rappresentando la maggior parte delle specie sulla Terra. Lo scopo di questa tesi di dottorato è stato quello di migliorare le conoscenze sulla diversità microbica e sulle dinamiche delle comunità microbiche in varie condizioni negli habitat in diversi processi biotecnologici nell ambito ambientale e industriale, nonché sulle interazioni microbiche utilizzando metodologie classiche e molecolari.
Nella prima parte è stata valutata l'efficienza dei letti biologici (biobed) in area Mediterranea nella degradazione dei fungicidi generalmente utilizzati nei vigneti valutando gli effetti sulla comunità microbica presente in questo ecosistema. I biobed sono sistemi biologici sviluppati nei paesi UE per proteggere i corpi idrici da contaminazione dei pesticidi a livello aziendale. I risultati hanno mostrato che il biobed ha una buona capacità di degradare i pesticidi. Infatti, alla fine dell'esperimento (112 giorni), la maggior parte dei pesticidi era quasi completamente degradata. Elettroforesi su gel in gradiente denaturante (DGGE) ha mostrato una variazione evidente nella diversità microbica dopo l'aggiunta dei fungicidi. Tuttavia, alla fine del processo di degradazione, nessun cambiamento significativo nella composizione della comunità microbica è stato rilevato. In questo caratteristico substrato utilizzato per allestire il biobed, i lieviti ed i funghi filamentosi ascomiceti sembrano essere i microrganismi maggiormente coinvolti nella attività degradativa.
Nella seconda parte di questa tesi di dottorato è stato indagato il possibile impiego del glicerolo grezzo come ammendante nel suolo. Il glicerolo grezzo è il principale sottoprodotto della produzione di biodiesel. L'industria del biodiesel è in rapida espansione negli ultimi anni e sta creando un eccesso di glicerolo grezzo come sottoprodotto. In questo contesto, quindi dobbiamo valutare usi alternativi per questo sottoprodotto. Considerando che il glicerolo grezzo è ricco in composti organici, è stato valutato l'effetto di diverse dosi di glicerolo sulla diversità microbica e sulle proprietà chimiche e biochimiche del terreno agricolo allo scopo di valutare il possibile uso agronomico del glicerolo grezzo, senza una sua ulteriore purificazione. I risultati dei metodi coltura dipendenti hanno mostrato che l'aggiunta di glicerolo grezzo ha stimolato la crescita di batteri e funghi coltivabili, mentre l'analisi DGGE ha mostrato che il glicerolo aggiunto aumenta la diversità batterica nel terreno. L’attività microbica in tutti i suoli trattati ha raggiunto uno stato stazionario in termini di attività respiratoria quotidiana indicando un adattamento positivo della biomassa microbica. Questa indagine iniziale ha mostrato che il glicerolo grezzo non sembra avere effetti negativi sul suolo, ma piuttosto favorisce lo sviluppo delle comunità microbiche e incrementa la diversità microbica.
Nella terza parte di questa tesi, è stata valutata l'influenza dei diversi trattamenti antifungini su lieviti che naturalmente colonizzano la superficie della bacca d’uva in un vigneto biologico (prodotti a base di rame/zolfo) e un vigneto convenzionale (fungicidi di uso comune). È stata condotta l’analisi quantitativa e qualitativa di lieviti presenti sulla superficie della bacca e nel succo d'uva durante il processo fermentativo, utilizzando i metodi coltura-dipendenti ed indipendenti. La quantità di lieviti che sono risultati presenti corrisponde al numero generalmente riportato per le uve mature, con un maggiore livello di colonizzazione nei campioni convenzionali rispetto a quelli biologici. L’isolamento diretto e l’analisi della DGGE dei campioni di uva alla fase iniziale di fermentazione hanno mostrato una più bassa diversità di lieviti nel vigneto biologico rispetto a quello convenzionale. Nei vigneti biologici e convenzionali, i lieviti dominanti erano Candida zemplinina e Hanseniaspora uvarum, rispettivamente, le specie tipiche per le superfici di bacche d'uve mature. Saccharomyces cerevisiae è stato isolato usando i metodi tradizionali e la DGGE solo alla fine della fermentazione (dopo autoarricchimento), mostrando livelli più bassi nei campioni biologici. Inoltre, S. cerevisiae ha mostrato una più bassa diversità intraspecifica nei campioni organici (due genotipi), in confronto con i campioni convenzionali (sei genotipi). Complessivamente, questi risultati mostrano che i trattamenti di rame e zolfo hanno una maggiore influenza negativa sui livelli quantitativi e sulla diversità della comunità lievitiforme che colonizza la bacca d’uva (incluso S. cerevisiae), in confronto con fungicidi utilizzati per i trattamenti convenzionali.
Nella quarta parte della tesi, l'attenzione è stata focalizzata sulle interazioni tra lieviti durante la fermentazione vinaria. Il controllo di questo processo, da tempo si effettua attraverso l’uso di colture selezionate di S. cerevisiae. Per migliorare la qualità e complessità del vino, recentemente, è stato proposto l’uso di fermentazioni miste controllate, con colture selezionate di S. cerevisiae e non-Saccharomyces. Lo scopo di questa indagine è stato quello di studiare l'influenza di Starmerella bombicola sul ceppo di S. cerevisiae a livello di espressione genica e di'attività enzimatica della piruvato decarbossilasi (Pdc1) e dell’alcool deidrogenasi (Adh1), i due enzimi chiave della fermentazione alcolica. Per fare ciò sono state utilizzate cellule immobilizzate di S. bombicola in fermentazione mista. I risultati hanno confermato un aumento di velocità di fermentazione, un consumo combinato di glucosio e fruttosio, un aumento di produzione del glicerolo, una riduzione della produzione del’etanolo e la modifica di sottoprodotti della fermentazione. Inoltre, S. bombicola in fermentazione mista ha mostrato una forte influenza sulla fermentazione alcolica di S. cerevisiae. Infatti, l’attività di Pdc1 in fermentazione mista è stata inferiore a quella mostrata in coltura pura, mentre l’attività di Adh1 ha mostrato un comportamento opposto. L'espressione dei geni PDC1 e ADH1 era altamente indotta nella fase iniziale di
fermentazione ed è stata più evidente nella cultura mista. L'influenza di S. bombicola sembra essere molto complessa e non limitata ad un effetto additivo sulla composizione analitica del vino, ma la sua presenza ha causato modificazioni metaboliche durante la fermentazione di S. cerevisiae determinando variazioni dell'espressione genica e dell'attività enzimatica della piruvato decarbossilasi e alcol deidrogenasi.Microorganisms play a central role in the regulation of ecosystem processes, and they comprise the vast majority of species on Earth. The aim of this PhD thesis was to improve our knowledge on microbial diversity and dynamics of microbial communities in various conditions and ecological habitats related to environmental and industrial biotechnological processes as well as on the microbial interactions by using molecular and classic methods.
In the first part of the present thesis it was evaluated the efficiency of the Mediterranean biomixture (the main part of a biobed) in the degradation of fungicides generally used to control pests in vineyards and to assess their effects on microbial community. Biobeds are biological systems developed all over EU countries to protect water-bodies from pesticide contamination at farm level. Results showed that the biomixture had a good capability of degrading pesticides. Indeed, at the end of the experiment (112 days), the concentration of most of the pesticides was close to complete degradation. Denaturing gradient gel electrophoresis (DGGE) analysis showed an evident modification of microbial diversity after the addition of fungicides. However, at the end of degradation process, no significant changes in the composition of microbial community were seen. In the specific substrate used in the biomixture, both yeast flora and ascomycete filamentous fungi seemed to be involved in the degradation activity.
In the second part of this PhD thesis it was investigated on the possible use of crude glycerol as a soil amendment. Crude glycerol is a principal by-product of biodiesel production. As the biodiesel industry is rapidly expanding over the last years, a glut of crude glycerol is being created, so there is an urgent need to find alternative uses for this by-product. Considering that crude glycerol is rich in organic compounds, a laboratory experiment was carried out to study the effect of different glycerol amounts on microbial diversity and chemical and biochemical properties of agricultural soil in order to assess the possible agronomical use of crude glycerol without further purification. Results of culture dependent methods showed that the addition of crude glycerol has stimulated the growth of cultivable bacteria and fungi, while DGGE analysis demonstrated that the added glycerol increase bacterial diversity in the soil. Microbial activity in all treated soils reached a steady-state condition in terms of daily respiration activity indicating a positive adaptation of the microbial biomass. This initial
investigation showed that the crude glycerol does not seem to have negative effects on the soil but rather causes the development of microbial communities and increases microbial diversity.
In the third part of this thesis, the yeast communities colonising grape berry surfaces were evaluated for the influence of fungicide treatments in an organic vineyard (copper/sulphur-based products) and a conventional vineyard (commonly used fungicides). Analysis of yeast abundance and diversity was carried out on grape berries and the grape juice during fermentation, using culture-dependent and -independent approaches. Yeast abundance was as generally reported for mature grapes, with higher counts from grapes treated with conventional fungicides. Direct isolation and DGGE analysis of initial grape samples showed less yeast species diversity in the organic vineyard compared with the conventional vineyard. In the organic and conventional vineyards, the dominant yeasts were Candida zemplinina and Hanseniaspora uvarum, respectively, typical species that colonise surfaces of mature grape berries. Saccharomyces cerevisiae was isolated by traditional methods and detected by DGGE only at the end of fermentation, with lower levels in the organic samples. Moreover, S. cerevisiae showed less intraspecific diversity in the organic samples (two genotypes), in comparison with the conventional samples (six genotypes). Altogether, these results show that the copper and sulphur treatments have greater negative influences on abundance and diversity of grape berry yeast communities (included S. cerevisiae), in comparison with fungicides used for conventional treatments.
In the fourth part of the thesis, the attention was focused on the yeast interactions during wine fermentation. The use of a multistarter fermentation process with S. cerevisiae and non Saccharomyces wine yeasts has been proposed to simulate natural must fermentation and to confer greater complexity and specificity to wine. The aim of this work was to study the influence of Starmerella bombicola on S. cerevisiae gene expression and enzymatic activity of pyruvate decarboxylase (Pdc1) and alcohol dehydrogenase (Adh1), the two key enzymes of the alcoholic fermentation pathway. The presence of S. bombicola immobilized cells in a mixed fermentation trial confirmed an increase in fermentation rate, a combined consumption of glucose and fructose, an increase in glycerol and a reduction in the production of ethanol as well as a modification in the fermentation byproducts. Also the alcoholic fermentation of S. cerevisiae was influenced by S. bombicola immobilized cells. Indeed, Pdc1 activity in mixed fermentation was lower than that exhibited in pure culture while Adh1 activity
showed an opposite behavior. The expression of both PDC1 and ADH1 genes was highly induced at the initial phase of fermentation which was more evident in mixed culture. S. bombicola immobilized cells greatly affected the fermentation behavior of S. cerevisiae and the analytical composition of wine. The influence of S. bombicola was not limited to a simple additive contribution but its presence caused metabolic modifications during S. cerevisiae fermentation causing variation in the gene expression and enzymatic activity of alcohol deydrogenase and pyruvate decarboxylase
A FEM-experimental approach for the development of a conceptual linear actuator based on tendrils free-coiling
No full textCash social transfers, direct taxes, and income distribution in late socialism
No full textThe author analyzes the impact of direct taxes and cash social transfers on income distribution in Bulgaria, Czechoslovakia, Hungary, Poland and Yugoslavia in the years before the collapse of communism. He contrasts the results for socialist and market economies. Cash social transfers accounted for about a fifth of gross income, a proportion comparable with that in developed welfare economies. Generally, cash transfers were unrelated to income in socialist countries, in marked contrast with market economies, where such transfers go mainly to low income households. Direct taxes played almost no role in income redistribution. They were small - 1 to 2 percent of gross income, except in Hungary - and proportional to income. Most taxes were paid by enterprises, as payroll taxes, and most workers were unaware of the taxation and that public spending could not permanently exceed public revenues from taxation. In socialist countries, social support was built into the system through full employment guarantees, state run pension schemes, and free public education and health care. The only explicit policy toward poverty involved alcoholics, handicapped people, and other special categories. This system is being replaced by a market system in which the labor market is key and those who cannot earn enough must be supported by the state. To counteract increasing income disparities, social transfers must be focussed more on the poor. Eastern European states are ill prepared for this role. They have no experience in identifying the needy and targeting support to them. The question is, toward which world of welfare capitalism are the formerly socialist countries likely to evolve? The author contends that the Central European countries will probably evolve toward the corporatist model of continental Europe. Capitalist countries in Europe tend to have large social transfers that are often related to previous earnings, so they have relatively limited roles in income distribution. Transfers are closer to social insurance than to social assistance. The evolution of more agricultural Balkan countries and the Slavic republics of the former Soviet Union is more difficult to predict. Poorer and more agriculture based countries are generally less able to administer welfare schemes, gauge individual incomes, deliver social support - and their finances may be even more strained than those of their Central European counterparts.Services&Transfers to Poor,Poverty Impact Evaluation,Economic Theory&Research,Environmental Economics&Policies,Safety Nets and Transfers
The Ricardian Vice: Why Sala-i-Martin’s calculations of world income inequality are wrong
No full textThe paper discusses recent world income inequality calculations by Sala- i-Martin. It shows that the two main problems with which the author had to grapple (too few data to derive countries’ income distributions, and sparseness of such data in time) are not solved in a satisfactory fashion. They, and several other simplifying assumptions, make Sala-i- Martin results very dubious. We argue that Sala-i-Martin has ended up by producing a population-weighted inter-national distribution of income augmented by a constant shift parameter and not a distribution of income among world citizens.income inequality, world, globalization
<it>Starmerella bombicola </it>influences the metabolism of <it>Saccharomyces cerevisiae </it>at pyruvate decarboxylase and alcohol dehydrogenase level during mixed wine fermentation
No full textAbstract Background The use of a multistarter fermentation process with Saccharomyces cerevisiae and non-Saccharomyces wine yeasts has been proposed to simulate natural must fermentation and to confer greater complexity and specificity to wine. In this context, the combined use of S. cerevisiae and immobilized Starmerella bombicola cells (formerly Candida stellata) was assayed to enhance glycerol concentration, reduce ethanol content and to improve the analytical composition of wine. In order to investigate yeast metabolic interaction during controlled mixed fermentation and to evaluate the influence of S. bombicola on S. cerevisiae, the gene expression and enzymatic activity of two key enzymes of the alcoholic fermentation pathway such as pyruvate decarboxylase (Pdc1) and alcohol dehydrogenase (Adh1) were studied. Results The presence of S. bombicola immobilized cells in a mixed fermentation trial confirmed an increase in fermentation rate, a combined consumption of glucose and fructose, an increase in glycerol and a reduction in the production of ethanol as well as a modification in the fermentation of by products. The alcoholic fermentation of S. cerevisiae was also influenced by S. bombicola immobilized cells. Indeed, Pdc1 activity in mixed fermentation was lower than that exhibited in pure culture while Adh1 activity showed an opposite behavior. The expression of both PDC1 and ADH1 genes was highly induced at the initial phase of fermentation. The expression level of PDC1 at the end of fermentation was much higher in pure culture while ADH1 level was similar in both pure and mixed fermentations. Conclusion In mixed fermentation, S. bombicola immobilized cells greatly affected the fermentation behavior of S. cerevisiae and the analytical composition of wine. The influence of S. bombicola on S. cerevisiae was not limited to a simple additive contribution. Indeed, its presence caused metabolic modifications during S. cerevisiae fermentation causing variation in the gene expression and enzymatic activity of alcohol deydrogenase and pyruvate decarboxilase.</p
Diffusive author(s), cohesive author: Analysis of S/N (1994)
No full textThis study indicates the ways in which various aspects of the author(s) are brought forth in Dumb type’s performance art, the S/N production. Previous research has suggested a non-hierarchical organization of Dumb type and the absence of a “privileged author” in Dumb type’s collaborative work, S/N. However, the results that I have investigated from member’s interviews on the creative process of S/N along with my analysis of the recorded images of S/N, indicate a different aspect of the author(s). First, S/N was created through, so to speak, the collective ideas of the members of Dumb type. Further, S/N has at least nine quotations from previous performances, installations, and printed writings, besides the work-in-progress technique. Explicating one of the “author functions” as given by Michel Foucault, each text has plural subjects of the author. However, it has been revealed from members’ interviews that Teiji Furuhashi had a decision-making role in selecting the members’ ideas within the performance. Since then, S/N has had plural subjects of creation; however, Furuhashi is one of the subjects of creation along with the “privileged author.” S/N has plural authors (diffusive authors) yet at the same time, it has a “privileged author,” Teiji Furuhashi (cohesive author)
Poverty, inequality, and social policy in transition economies
No full textIn examining what happens to poverty and income inequality during the early period of transition to a market economy, the author covers the period up to 1993. His analysis includes almost all transition economies that were not affected by wars, blockades, or embargoes. (In economies so affected, the intrinsic issues of transition are overshadowed by more basic issues of war or quasi-war economy and survival). The two key issues of social policy in transition economies are pension reform and better targeting of social assistance. Pensions represent 70 to 80 percent of cash social expenditures. No reduction of current levels of social spending (which is unsustainable) can be envisaged without pension reform. Better targeting of social assistance is needed because many universally or enterprise-provided benefits have been terminated, poverty has increased, and social programs lack funding. If poverty is on the rise and money is scarce, better targeting is the only option.Health Monitoring&Evaluation,Services&Transfers to Poor,Environmental Economics&Policies,Public Health Promotion,Poverty Impact Evaluation,Environmental Economics&Policies,Safety Nets and Transfers,Services&Transfers to Poor,Rural Poverty Reduction,Health Monitoring&Evaluation
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Grape berry yeast communities: Influence of fungicide treatments
No full textThe yeast communities colonising grape berry surfaces were evaluated for the influence of fungicide treatments in an organic vineyard (copper/sulphur-based products) and a conventional vineyard (commonly used fungicides). Analysis of yeast abundance and diversity was carried out on grape berries and juice during fermentation, using culture-dependent and -independent approaches. Yeast abundance was as generally reported for mature grapes and it was slight higher from grapes treated with conventional fungicides. Initial grape samples showed less yeast species diversity in the organic vineyard compared with the conventional one. In both vineyards, the dominant yeast were Candida zemplinina and Hanseniaspora uvarum (>50%), respectively, typical species that colonise surfaces of mature grape berries. Metschnikowia pulcherrima was widely found in the conventional samples while it was only occasionally found in organic ones.
Saccharomyces cerevisiae was isolated only at the end of natural fermentation (conducted in sterile condition), with lower levels in the organic samples. S. cerevisiae strains showed less intraspecies diversity in the organic samples (two genotypes), in comparison with the conventional samples (six genotypes)
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