Accelerating retreat and high-elevation thinning of glaciers in central Spitsbergen

Svalbard is a heavily glacier-covered archipelago in the Arctic. Dickson Land (DL), in the central part of the largest island, Spitsbergen, is relatively arid, and as a result, glaciers there are relatively small and restricted mostly to valleys and cirques. This study presents a comprehensive analysis of glacier changes in DL based on inventories compiled from topographic maps and digital elevation models for the Little Ice Age maximum (LIA), the 1960s, 1990 and 2009/11. Total glacier area decreased by ~38 % since the LIA maximum, and front retreat has increased over the study period. Recently, most of the local glaciers have been consistently thinning in all elevation bands, in contrast to larger Svalbard ice masses which remain closer to balance. The mean 1990–2009/11 geodetic mass balance of glaciers in DL is among the most negative from the Svalbard regional means known from the literature.

Deformation mechanisms in second-phase affected microstructures and their energy balance

Based on the relationship Zener parameter (Z=second-phase size/second-phase volume fraction) vs. calcite grain size (dg), second-phase controlled aggregates and microstructures that are weakly affected by second-phases are discriminated. The latter are characterized by large but constant grain sizes, high calcite grain boundary fractions and crystallographic preferred orientations (CPO), while calcite grain size and calcite grain boundary fraction decrease continuously and CPO weakens with decreasing Z in second-phase controlled microstructures. These observations suggest that second-phase controlled microstructures predominantly deform via granular flow because pinning of calcite grain boundaries reduces the efficiency of dynamic recrystallization favoring mass transfer processes and grain boundary sliding. In contrast, the balance of grain size reduction and growth by dynamic recrystallization maintains a steady state grain size in microstructures that are only weakly affected by second-phases promoting a predominance of dislocation creep. With increasing temperature, the relationship between Z and dg persists but the calcite grain size increases continuously. Based on microstructures, the energy of each modifying process is calculated and its relative contribution is compared with energies of the competing processes (surface energy, dragging energy, dynamic recrystallization energy). The steady state microstructures result from a temperature-dependent energy minimization procedure of the system.

The negation of the other in the novel Sula by Toni Morrison [recurso electr?nico]

This analysis corresponds to an analytical and interpretative essay on the negation of the other in the novel Sula (1973) by Toni Morrison, one of the most important African American writers. In Sula, the author explores the concepts of good and evil as she provides characteristics of the African American culture and black identity. The characters? main struggle is their quest for achieving an authentic identity within this sexist and racist society that constricts their lives and dreams with moral standards. This essay attempts to demonstrate through this novel how human beings find self-destruction by attempting to destroy others, those who have different views of life and the world. The analysis focuses on the most important aspects of life proposed in this book: self-awareness, identity, friendship, traveling, the community, and heritage, which condition one?s vision towards the other and nurture, at the same time, one?s whole identity. As a major conclusion, there is no success for a society that judges and isolates the individuals who want to become authentic and attempt to break the constrictions of moral prejudices. For each member of the community is essential in the balance of it.

A study on the effect of functional distribution of income on aggregate demand

In this thesis, we study the causal relationship between functional distribution of income and economic growth. In particular, we focus on some of the aspects that might alter the effect of the profit share on growth. After a brief introduction and literature review, the empirical contributions will be presented in Chapters 3,4 and 5. Chapter 3 analyses the effect of a contemporaneous decrease in the wage share among countries that are major trade partners. Falling wage share and wage moderation are a global phenomenon which are hardly opposed by governments. This is because lower wages are associated with lower export prices and, therefore, have a positive effect on net-exports. There is, however, a fallacy of composition problem: not all countries can improve their balance of payments contemporaneously. Studying the country members of the North America Free Trade Agreement, we find that the effect on export of a contemporaneous decrease in the wage share in Mexico, Canada and the United States, is negative in all countries. In other words, the competitive advantage that each country gains because of a reduction in its wage share (to which is associated a decrease in export prices), is offset by a contemporaneous increase in competitiveness in the other two countries. Moreover, we find that NAFTA is overall wage-led: the profit share has a negative effect on aggregate demand. Chapter 4 tests whether it is possible that the effect of the profit share on growth is different in the long run and in the short run. Following Blecker (2014) our hypothesis is that in the short run the growth regime is less wage-led than it is in the long run. The results of our empirical investigation support this hypothesis, at least for the United States over the period 1950-2014. The effect of wages on consumption increases more than proportionally compared to the effect of profits on consumption from the short to the long run. Moreover, consumer debt seem to have only a short-run effect on consumption indicating that in the long run, when debt has to be repaid, consumption depends more on the level of income and on how it is distributed. Regarding investment, the effect of capacity utilization is always larger than the effect of the profit share and that the difference between the two effects is higher in the long run than in the short run. This confirms the hypothesis that in the long run, unless there is an increase in demand, it is likely that firms are not going to increase investments even in the presence of high profits. In addition, the rentier share of profits – that comprises dividends and interest payments – has a long-run negative effect on investment. In the long run rentiers divert firms’ profits from investment and, therefore, it weakens the effect of profits on investment. Finally, Chapter 5 studies the possibility of structural breaks in the relationship between functional distribution of income and growth. We argue that, from the 1980s, financialization and the European exchange rate agreements weakened the positive effect of the profit share on growth in Italy. The growth regime is therefore becoming less profit-led and more wage-led. Our results confirm this hypothesis and also shed light on the concept of cooperative and conflictual regimes as defined by Bhaduri and Marglin (1990).

Effects of different intensity of early leaf removal on vegetative and productive activity and grape quality (cv. Nero d'Avola, Vitis vinifera)

Mestrado Vinifera Euromaster - Instituto Superior de Agronomia - UL

Timing and economic value of mergers and acquisitions

Doctor of Philosophy in the Faculty of Business Administration

Removal of paracetamol on biomass-derived activated carbon: Modeling the fixed bed breakthrough curves using batch adsorption experiments

The remediation of paracetamol (PA), an emerging contaminant frequently found in wastewater treatment plants, has been studied in the low concentration range (0.3–10 mg L−1) using as adsorbent a biomass-derived activated carbon. PA uptake of up to 100 mg g−1 over the activated carbon has been obtained, with the adsorption isotherms being fairly explained by the Langmuir model. The application of Reichemberg and the Vermeulen equations to the batch kinetics experiments allowed estimating homogeneous and heterogeneous diffusion coefficients, reflecting the dependence of diffusion with the surface coverage of PA. A series of rapid small-scale column tests were carried out to determine the breakthrough curves under different operational conditions (temperature, PA concentration, flow rate, bed length). The suitability of the proposed adsorbent for the remediation of PA in fixed-bed adsorption was proven by the high PA adsorption capacity along with the fast adsorption and the reduced height of the mass transfer zone of the columns. We have demonstrated that, thanks to the use of the heterogeneous diffusion coefficient, the proposed mathematical approach for the numerical solution to the mass balance of the column provides a reliable description of the breakthrough profiles and the design parameters, being much more accurate than models based in the classical linear driving force.

Cold Season Physiology of Arctic Plants

The cold season in the Arctic extends over eight to nine months during which ecosystem gas exchange and water balance of arctic plants have been largely unexplored. The overall objective of this thesis was to examine two critical gaps in our knowledge about tundra cold season processes – ecosystem respiration at very low temperatures and water uptake during the winter-spring transition. I determined the temperature response of ecosystem respiration of tundra monoliths down to temperatures as low as can be expected under snow-covered conditions (-15 °C). Temperature responses fit the Arrhenius function well with Q10 values over the range of -15 to 15 °C varying from 6.1 to 4.8. I used deuterium-enriched water (2H2O) as a tracer to evaluate water uptake of evergreen plants at snowmelt when soils are largely frozen. The results revealed that evergreen plants take up water under snow cover, possibly via roots but undoubtedly by foliar uptake.

Social-cognitive Antecedents of Ambidextrous Orientation in Family-owned Startups: The Role of Family Ties, Achievement Motivation, and Internal Locus of Control

Regulatory Focus Theory predicts that the motivation to self-regulate goal-directed thought and behavior depends on two distinct regulation strategies: a promotion focus based on attaining gains and a prevention focus based on avoiding losses. This study took a social-cognitive approach predicting that regulatory focus has an impact on how family startups (several family related founders) explore “new ideas”, exploit “old certainties” and achieve the balance of both (ambidexterity), compared to lone founder startups (only one founder present). It was proposed that the social context of family ties among founders leads them to a prevention focus concerned with avoiding the loss of the socio-emotional benefits of those ties. In order to avoid such a loss, family founders were expected to increase their risk perceptions and thus, explore less than lone founders, who lack such socio-emotional ties. It was also proposed that two commonly used psychological traits in entrepreneurship research --achievement motivation and internal locus of control, predispose entrepreneurs to a promotion focus. Founders with a promotion focus, in turn, were hypothesized to lead startups to more risk-seeking behaviors and to more explorative orientation. The previous argument was used as a springboard to derive hypotheses about ambidexterity (the ability to exploit and explore simultaneously) and survival hazards. Using Regulatory Focus Theory, exploitative orientation, conceptualized as the motivational strength to continue on previous paths of action, was hypothesized to be not significantly different from that of lone founder startups. Taking previous arguments together, lone founder startups were hypothesized to be more ambidextrous than family startups. Finally, ambidexterity and internal locus of control were hypothesized to reduce survival hazards in family startups. The findings suggested that family startups explore less than lone founder startups even after controlling for group effects. Interesting but contradictory findings revealed that internal locus of control have both a positive direct effect and a positive interaction that increases the explorative and ambidextrous orientation gap of family startups over lone founder startups. As expected, ambidexterity and internal locus of control reduced survival hazards on family startups. Implications for practitioners were derived based on a sample of 470 nascent entrepreneurs.

Emergetic evaluation of cattle rearing in a montado farm

O Montado, em Portugal, é um complexo sistema silvopastoril de uso da terra, tipicamente Mediterrânico, com diversos estratos de vegetação, incluindo sobreiro e azinheira em várias densidades, onde é frequente a criação de gado. Esta actividade pecuária beneficia das pastagens no sob-coberto, de algumas espécies arbustivas e também das bolotas que caem do coberto arbóreo, contribuindo para evitar a invasão da pastagem por matos. No entanto, dependendo da sua gestão, este gado pode comprometer a regeneração do sistema. Nos últimos 20 anos, os subsídios no âmbito da Política Agrícola Comum da União Europeia têm promovido a criação de gado bovino em detrimento de outras espécies e raças mais leves, bem como a intensificação desta produção. Esta intensificação pode impossibilitar a regeneração natural das árvores ameaçando o equilíbrio do Montado. Por esta razão é necessária uma avaliação focada na criação de gado bovino e nos seus impactos sobre o sistema. O objectivo deste estudo foi obter uma melhor compreensão do funcionamento de uma exploração silvopastoril num sistema de Montado, através da aplicação do Método de Avaliação Emergética e do cálculo de índices emergéticos. Pretende-se assim compreender a melhor forma de o gerir, bem como conceber estratégias que maximizem o fluxo de emergia na exploração. Uma comparação deste método com a avaliação económica permitiu perceber em que aspectos esta pode ser complementada pelo método da avaliação emergética. O método da avaliação emergética permite a avaliação de sistemas multifuncionais complexos à escala de uma exploração individual, fornecendo informação extra em relação à avaliação económica como a renovabilidade dos inputs do sistema, ou a quantidade de fluxos livres da natureza que é valorada por preços de mercado. Este método permite a integração das emternalidades e das externalidades à contabilização económica, transformando uma avaliação tendencialmente separada do seu sistema mais vasto, numa avaliação de um sistema em conexão com aqueles mais vastos nos quais se integra; Abstract: The Montado, in Portugal, is a complex silvo-pastoral system of land use, typically Mediterranean, with different strata of vegetation, including cork and holm oaks in various densities, and where cattle rearing is common. This stockfarm benefits from the herbaceous layer under the trees, as well as from some species in the shrub layer, and also from the acorns faling down from the tree cover, while contributing to prevent the invasion of pastures by shrubs. Nevertheless, depending on its management, livestock can affect the system regeneration. Over the past 20 years, subsidies of the European Union's common agricultural policy have promoted the cattle rearing at expense of other lighter species and breeds, as well as its intensification. This intensification may impair the natural regeneration of trees threatening the balance of the Montado. Therefore an assessment focused on cattle and their impact on the system is required. The purpose of this study was to obtain a better understanding of the functioning of a silvo-pastoral farm in a Montado system, by applying the emergy evaluation method and through the calculation of emergy indices. It is intended to understand the best way to manage and design strategies that maximize the emergy flow on the farm. A comparison of this method with the economic evaluation allowed to realize in what aspects it can be complemented by the emergy evaluation method. The emergy evaluation method alows the assessment of complex multi-functional systems at the scale of an individual farm, providing extra information in relation to economic avaluation as the renewability of the inputs to a system and the amount of free flows of nature that is valued by market prices. This method allows the integration of the emternalities and the externalities to the economic accounting, transforming an evaluation tended separated from its wider system, in an evaluation of a system in connection with the larger ones on which it is incorporated.

Emergy analysis of a silvo-pastoral system, a case study in southern Portugal

The Mediterranean silvo-pastoral system known as Montado, in Portugal, is a complex land use system composed of an open tree stratum in various densities and an herbaceous layer, used for livestock grazing. Livestock also profit from the acorns, and the grazing contributes to avoid shrub encroachment. In the last 20 years, subsidies from the European Union have greatly promoted cattle rearing in this system and the introduction of heavy breeds, at the expense of sheep, goats or the native cattle breeds. The balance of the traditional system is thus threatened, and a precise assessment of the balance between the different components of the system, therefore is highly needed. The goal of this study was to gain a better under- standing of a Montado farm system with cattle rearing as the major economic activity by applying the emergy evaluation method to calculate indices of yield, investment, environmental loading and sustainability. By integrating different ecosystem components, the emergy evaluation method allows a comprehensive evaluation of this complex and multifunctional system at the scale of an individual farm. This method provides a set of indices that can help us understand the system and design management strategies that maximize emergy flow in the farm. In this paper, we apply the emergy evaluation method to a Montado farm with cattle rearing, as a way to gain a better understanding of this system at the farm scale. The value for the transformity of veal (2.66E?06 sej J-1) is slightly higher, when compared to other systems producing protein. That means that the investment of nature and man in this product was higher and it requires a premium price on the market. The renewa- bility for Holm Oaks Farm (49 %), lower than for other similar systems, supports the assumption that this is a farm in which, comparing with others, the number of purchased inputs in relation to renewable inputs provided by nature, is higher. The Emergy Investment Ratio is 0.91 for cattle rearing compared to a value of 0.49 for cork and 0.43 for firewood harvesting, making it clear that cattle rearing is a more labor demanding activity comparing with extractive activities as cork and firewood harvesting.

Mapping spatial and temporal potassium balances in Brazilian soils of south-west Goias.

Introduction: Brazil, is one of the main agricultural producers in the world ranking 1st in the production of sugarcane, coffee and oranges. It is also 2nd as world producer of soybeans and a leader in the harvested yields of many other crops. The annual consumption of mineral fertilizers exceeds 20 million mt, 30% of which corresponds to potash fertilizers (ANDA, 2006). From this statistic it may be supposed that fertilizer application in Brazil is rather high, compared with many other countries. However, even if it is assumed that only one fourth of this enormous 8.5 million km2 territory is used for agriculture, average levels of fertilizer application per hectare of arable land are not high enough for sustainable production. One of the major constraints is the relatively low natural fertility status of the soils which contain excessive Fe and Al oxides. Agriculture is also often practised on sandy soils so that the heavy rainfall causes large losses of nutrients through leaching. In general, nutrient removal by crops such as sugarcane and tropical fruits is much more than the average nutrient application via fertilization, especially in regions with a long history of agricultural production. In the recently developed areas, especially in the Cerrado (Brazilian savanna) where agriculture has expanded since 1980, soils are even poorer than in the "old" agricultural regions, and high costs of mineral fertilizers have become a significant input factor in determining soybean, maize and cotton planting. The consumption of mineral fertilizers throughout Brazil is very uneven. According to the 1995/96 Agricultural Census, only in eight of the total of 26 Brazilian states, were 50 per cent or more of the farms treated "systematically" with mineral fertilizers; in many states it was less than 25 per cent, and in five states even less than 12 per cent (Brazilian Institute for Geography and Statistics; Censo Agropecuario1995/96, Instituto Brazileiro de Geografia e Estadistica; IBGE, www.ibge.gov.br). The geographical application distribution pattern of mineral fertilizers may be considered as an important field of research. Understanding geographical disparities in fertilization level requires a complex approach. This includes evaluation of the availability of nutrients in the soil (and related soil properties e.g. CEC and texture), the input of nutrients with fertilizer application, and the removal of nutrients by harvested yields. When all these data are compiled, it is possible to evaluate the balance of particular nutrients for certain areas, and make conclusions as to where agricultural practices should be optimized. This kind of research is somewhat complicated, because it relies on completely different sources of data, usually from incomparable data sources, e.g. soil characteristics attributed to soil type areas, in contrast to yields by administrative regions, or farms. A priority tool in this case is the Geographical Information System (GIS), which enables attribution of data from different fields to the same territorial units, and makes possible integration of these data in an "inputoutput" model, where "input" is the natural availability of a nutrient in the soil plus fertilization, and "output" export of the same nutrient with the removed harvested yield.

Probiotics for the prevention/treatment of human diseases and ecological study of the intestinal microbiota

The interest in human intestinal microbiota has increased in the last 20 years and significant advances have been achieved with regard to its composition and functions. The gut microbiota contributes to the maintenance of the host health status and, since alterations in the gut microbiota have been involved in the pathogenesis/progression of some diseases, several studies have focused on the manipulation of its composition. Probiotics are a strategy to maintain/restore the correct balance of gut microbial population and to prevent/treat diseases. The aim of this thesis was to explore the possibility of probiotic supplementation for the prevention/treatment of human diseases and the related study of the intestinal microbial environment. After reviewing studies concerning the use of Bifidobacterium breve as probiotic in paediatric diseases, the effectiveness of a probiotic formulation consisting of two strains of B. breve was assessed in paediatric subjects for the prevention or alleviation of gastrointestinal disorders, including coeliac disease and paediatric obesity. As the emerging role of gut microbiota in neurological diseases, the intestinal microbial environment in amyotrophic lateral sclerosis patients compared to healthy controls and the effects of a probiotic administration were examined. Considering the role of viruses in shaping gut microbiota, gut bacteriophages and bacterial community of preterm infants were investigated. The results evidenced differences in gut microbial composition of healthy controls and diseased subjects in coeliac and amyotrophic lateral sclerosis patients. The probiotic approach was effective in restoring the microbial composition in the former, whereas, in the latter, the influence was focused only on some microbial groups. The probiotic intervention was effective in improving the glyco-insulinemic profile in obese children and in preventing gastrointestinal disorders in healthy newborns. The study of the bacterial and phage composition in preterm infants suggested a transkingdom interplay between bacteria and viruses with a reciprocal influence on their composition.

Nature in the books of seven metals – Ǧābirian corpus in dialogue with ancient Greek philosophy and Byzantine alchemy –

The Ǧābirian corpus was a receiver of ancient Greek ideas and, at the same time, a source of knowledge for the later Greek-speaking world, in particular for medieval Byzantine alchemy. Both aspects are explored in the dissertation with respect to the notion of nature. After a general introduction to the Corpus and the sciences described in it, particular attention is devoted to a Byzantine anonymous text, The Work of Four Elements, which was probably influenced by the Ǧābirian Books of Seventy. These texts exemplify how, in the theory of the Ǧābirian science, things are constructed from four natures (hot, cold, moist and dry), the balance of which defines what a thing is. By changing the balance of natures, one can transmute any metals into gold that is perfectly proportioned in terms of natures. Ǧābir presents the art of dyeing metals gold in the Books of Seven Metals which, along with chrysopoetic recipes, also include medical recipes and theoretical contents such as the theories of four humours, properties, and talismans. Moreover, Ǧābir postulated a substrate that does not change in itself and continues to exist when natures move in and out of things. Such primary existence is called the fifth nature as an additional principle to the four natures. This key concept for the Ǧābirian theory, which has been underexplored so far, is discussed through the textual and critical analysis of various unedited sources: the Books of Seven Metals and the Book of the Fifth Nature. This study confirms that the fifth nature was probably derived from ancient Greek philosophical concepts such as the Empedoclean particles, the Aristotelian fifth element and the Stoic pneuma. Thus, this research indicates the importance of the Ǧābirian corpus both in the history of alchemy and the history of philosophy.

Characterization and management of particular classes of waste at a regional level. case study: Marche region

There are various methods to analyse waste, which differ from each other according to the level of detail of the compositio. Waste composed by plastic and used for packaging, for example, can be classified by chemical composition of the polymer used for the specific product. At a more basal level, before dividing a waste according to the specific chemical material of which it is composed it is possible and also important to classify it according to the material category. So, if the secondary aim is to consider the particular polymer that constitutes a plastic waste, or what kind of natural polymer composes a specific waste made of wood, the first aim is to classify the product category of the material that makes up the waste, so, if it is wood made, or plastic, or glass made or metal, or organic. There are not specific instruments to make this subdivision, not specific chemical tests, but only a manual recognition of the material that makes up the product or waste. The first steps of this study is a recognition of the materials of which the waste is composed, the second is a the quantification of differentiated and unsorted waste produced in the area under study, the third is a mass balance of the portions of waste sent for recovery in order to obtain information on quantities that can be effectively recovered and ready for new life cycle as raw material; the fourth and last step is an environmental assessment that provides information on the environmental cost of the recovery process. This process scheme is applied to various specific kinds of waste from separate collection generated in a specific area with the aim to find a model analysis appliable to other portions of territory in order to improve knowledge of recovery technologies.