1,012 research outputs found

    Predicting stream baseflow using genetic programing

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    Developing reliable methods to estimate stream baseflow has been a subject of research over the past decades due to its importance in catchment response and sustainable watershed management (e.g. ground water recharge vs. extraction). Limitations and complexities of existing methods have been addressed by a number of researchers. For instance, physically based numerical models are complex, requiring substantial computational time and data which may not be always available. Artificial Intelligence (AI) tools such as Genetic Programming (GP) have been used widely to reduce the challenges associated with complex hydrological systems without losing the physical meanings. However, up to date, in the absence of complex numerical models, baseflow is frequently estimated using statistically derived empirical equations without significant physical insights. This study investigates the capability of GP in estimating baseflow for a small monitored semi-urban catchment (0.021 km2) located in Singapore. A Recursive Digital Filter (RDF) is first adopted to separate the baseflow from observed streamflow. GP is then used to derive an empirical equation to relate the filtered baseflow time series particularly with groundwater table fluctuations which are relatively easy to be measured and are physically related to baseflow generation. The equation is then validated with a longer time series of baseflow data from a groundwater numerical model. These results indicate that GP is an effective tool in determining baseflow.postprin

    A 2D/3D image analysis system to track fluorescently labeled structures in rod-shaped cells: application to measure spindle pole asymmetry during mitosis.

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    BACKGROUND: The yeast Schizosaccharomyces pombe is frequently used as a model for studying the cell cycle. The cells are rod-shaped and divide by medial fission. The process of cell division, or cytokinesis, is controlled by a network of signaling proteins called the Septation Initiation Network (SIN); SIN proteins associate with the SPBs during nuclear division (mitosis). Some SIN proteins associate with both SPBs early in mitosis, and then display strongly asymmetric signal intensity at the SPBs in late mitosis, just before cytokinesis. This asymmetry is thought to be important for correct regulation of SIN signaling, and coordination of cytokinesis and mitosis. In order to study the dynamics of organelles or large protein complexes such as the spindle pole body (SPB), which have been labeled with a fluorescent protein tag in living cells, a number of the image analysis problems must be solved; the cell outline must be detected automatically, and the position and signal intensity associated with the structures of interest within the cell must be determined. RESULTS: We present a new 2D and 3D image analysis system that permits versatile and robust analysis of motile, fluorescently labeled structures in rod-shaped cells. We have designed an image analysis system that we have implemented as a user-friendly software package allowing the fast and robust image-analysis of large numbers of rod-shaped cells. We have developed new robust algorithms, which we combined with existing methodologies to facilitate fast and accurate analysis. Our software permits the detection and segmentation of rod-shaped cells in either static or dynamic (i.e. time lapse) multi-channel images. It enables tracking of two structures (for example SPBs) in two different image channels. For 2D or 3D static images, the locations of the structures are identified, and then intensity values are extracted together with several quantitative parameters, such as length, width, cell orientation, background fluorescence and the distance between the structures of interest. Furthermore, two kinds of kymographs of the tracked structures can be established, one representing the migration with respect to their relative position, the other representing their individual trajectories inside the cell. This software package, called "RodCellJ", allowed us to analyze a large number of S. pombe cells to understand the rules that govern SIN protein asymmetry. CONCLUSIONS: "RodCell" is freely available to the community as a package of several ImageJ plugins to simultaneously analyze the behavior of a large number of rod-shaped cells in an extensive manner. The integration of different image-processing techniques in a single package, as well as the development of novel algorithms does not only allow to speed up the analysis with respect to the usage of existing tools, but also accounts for higher accuracy. Its utility was demonstrated on both 2D and 3D static and dynamic images to study the septation initiation network of the yeast Schizosaccharomyces pombe. More generally, it can be used in any kind of biological context where fluorescent-protein labeled structures need to be analyzed in rod-shaped cells. AVAILABILITY: RodCellJ is freely available under http://bigwww.epfl.ch/algorithms.html, (after acceptance of the publication)

    The uniting of Europe and the foundation of EU studies: revisiting the neofunctionalism of Ernst B. Haas

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    This article suggests that the neofunctionalist theoretical legacy left by Ernst B. Haas is somewhat richer and more prescient than many contemporary discussants allow. The article develops an argument for routine and detailed re-reading of the corpus of neofunctionalist work (and that of Haas in particular), not only to disabuse contemporary students and scholars of the normally static and stylized reading that discussion of the theory provokes, but also to suggest that the conceptual repertoire of neofunctionalism is able to speak directly to current EU studies and comparative regionalism. Neofunctionalism is situated in its social scientific context before the theory's supposed erroneous reliance on the concept of 'spillover' is discussed critically. A case is then made for viewing Haas's neofunctionalism as a dynamic theory that not only corresponded to established social scientific norms, but did so in ways that were consistent with disciplinary openness and pluralism

    The changing patterns of group politics in Britain

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    Two interpretations of ways in which group politics in Britain have presented challenges to democracy are reviewed: neo-corporatism or pluralistic stagnation and the rise of single issue interest groups. The disappearance of the first paradigm created a political space for the second to emerge. A three-phase model of group activity is developed: a phase centred around production interests, followed by the development of broadly based 'other regarding' groups, succeeded by fragmented, inner directed groups focusing on particular interests. Explanations of the decay of corporatism are reviewed. Single issue group activity has increased as party membership has declined and is facilitated by changes in traditional media and the development of the internet. Such groups can overload the policy-making process and frustrate depoliticisation. Debates about the constitution and governance have largely ignored these issues and there is need for a debate

    Immigrant integration policy-making in Italy. Regional policies in a multi-level governance perspective

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    This article contributes to the debate on the local governance turn' by considering a recent immigration context: the Italian case. We analyse integration policies and governance processes in three regions: Lombardy, Piedmont and Emilia-Romagna. The aim is to shed new light on the multi-level governance relations that shape immigrant integration policies, taking into account the interdependencies of the vertical and horizontal dimensions of multi-level governance. The analysis points out the emergence of different multi-level governance arrangements and highlights the relevance of institutional and organisational factors in accounting for local differentiation. General traditions and established public-non-governmental organisation relations in the social policy field, the internal organisation of the regional administration (specialised staff versus general bureaucratic apparatus), and the role of ideology appear to make a difference. The implications of this analysis for multi-level governance scholarship are discussed, emphasising the need for a middle-range theory approach. Points for practitioners Multi-level governance is considered by policy scholars as a promising approach to make sense of increasingly complex policymaking processes, implying the interaction between different levels of government and between public and non-public actors. By considering the politically sensitive immigrant integration issue, this article attempts to point out how multi-level governance relations concretely take shape at the regional level in Italy, and which factors account for regional differentiation. Our study suggests that contextual and organisational factors are particularly relevant, that is, social policy traditions, the regions' internal organisation and the individual civil servants' attitudes. Nevertheless, politics should also be carefully taken into account

    Constraints of small-scale irrigated fodder production and nutrition assessment for livestock feed, a case study in Ethiopia

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    Livestock is an integral part of the agricultural system in sub-Saharan Africa, serving as a food source, income, fertilizer, and power for farming and transportation. However, the productivity of the livestock system has been hampered due to a lack of sufficient quantity and quality feed. This study evaluates the gaps and constraints of fodder and nutritional potential for livestock feed using small-scale irrigation (SSI). The study comprised of 30 randomly selected farmers from two different ecological zones in Ethiopia. Half of the farmers cultivated Napier grass (Pennisetum purpureum) in the Robit watershed in northern Ethiopia, and the other half cultivated mixed vetch (Lathyrus cicera) and oats (Avena sativa) in Lemo watershed in southern Ethiopia. The Soil and Water Assessment Tool (SWAT) and Agricultural Policy Environmental eXtender (APEX) were applied in an integrated manner to assess the impacts of SSI at the watershed and field-scale levels, respectively. The watershed-scale analysis showed that there is a substantial amount of surface runoff and shallow groundwater recharge that could be used for dry season fodder production using irrigation. Field data calibrated APEX model indicated that Napier yield could be maximized with 550 mm of water in Robit watershed. While in the Lemo watershed, maximum vetch and oats yield may be achieved with 250 mm of water. The major constraints for Napier and oats production in the study sites were soil fertility, especially nitrogen and phosphorus, and vetch production was limited by high temperature. Fodder samples were collected at the time of harvest to evaluate feed quality. The nutritional analysis indicated that Napier grass has a higher dry matter and ash (mineral) content compared to oats and vetch. However, vetch has higher crude protein content (18%) compared to Napier (10%) and oats (6%). Overall the study indicated that cultivating vetch provided superior performance in terms of providing quality feed and environmental services

    Continuity or change in business representation in Britain? An assessment of the Heseltine initiatives of the 1990s

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    Britain has a fragmented, overlapping, and underresourced system of business representation. Attempts at reform, however, have proved difficult and largely unsuccessful. A coherent and logical system is relevant, in terms of both an effective dialogue between government and business, and the promotion of competitiveness and productivity. Through interviews and archival evidence, I look at how government has attempted to reform business associations. The main focus is the Heseltine initiatives of the 1990s: I outline the various initiatives taken, reveal the extent to which policy represented continuity or change, and consider whether the initiatives were effective. I show that they had a degree of success but that they would have made greater impact if they had been sustained over a longer period of time. A consideration of the historical context, moreover, suggests there may be limits to the role of government intervention in business association reform

    Are language production problems apparent in adults who no longer meet diagnostic criteria for attention-deficit/hyperactivity disorder?

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    In this study, we examined sentence production in a sample of adults (N = 21) who had had attention-deficit/hyperactivity disorder (ADHD) as children, but as adults no longer met DSM-IV diagnostic criteria (APA, 2000). This “remitted” group was assessed on a sentence production task. On each trial, participants saw two objects and a verb. Their task was to construct a sentence using the objects as arguments of the verb. Results showed more ungrammatical and disfluent utterances with one particular type of verb (i.e., participle). In a second set of analyses, we compared the remitted group to both control participants and a “persistent” group, who had ADHD as children and as adults. Results showed that remitters were more likely to produce ungrammatical utterances and to make repair disfluencies compared to controls, and they patterned more similarly to ADHD participants. Conclusions focus on language output in remitted ADHD, and the role of executive functions in language production

    The Paradoxes of Democracy and the Rule of Law

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    The promise of modernization after the Second World War was that economic growth, equality, the rule of law and democracy would proceed together. In many ways, this has happened. Yet many of the promises of social progress developed after WWII have been undermined by internal tensions within the democratic project, as well as by social and economic trends. While stating the challenges that these trends have posed for democratic institutions and actors, we also look at the responses (both proposals and practices) that have emerged in order to address those challenges. In doing this, we note that the very conception of democracy as liberal democracy (based on delegation and majority voting) is under stress as neoliberalism has attacked those very intermediary institutions (parties, unions, voluntary associations) that had been at the basis of the development of the welfare state and democratic capitalism. We start by noting the growth in inequality, which means that formal democracy is shaped by uneven power resources as concentration of wealth provides advantages in the capacity to influence public decision making with mutual convertibility of economic and political resources. The spiral of inequality and corporate political power is reflected in a growing legitimacy crisis in old and new democracies. Liberalism, which promised the separation between the state and the market, has evolved into neoliberalism, , based on the domination of the corporation, exacerbated by privatization and de-regulation. This has raised private profit criteria about considerations of the broader public good and in many cases encouraged corruption. The ensuing inefficiency and lack of transparency foster institutional mistrust, with perverse effects. Challenges are also related to the fact that democracy has been mainly defined in a national mode, with the demos identified as the nation. Economic rescaling produced by global capitalism has however a produced both de-territorialization and re-territorialization, which requires a (yet unachieved) rethinking of the basis for democracy but also of welfare and its foundation in both identities and institutions. In the North and (with different characteristics) in the South of the globe, movement of capital and of people pose challenges of national pluralism and its constitutional recognition, questioning key concepts such as the definition of political community and popular sovereignty and the . relationship between human rights and citizenship. Citizenship is more appropriately considered as related not to fixed institutions but rather as ‘acts of citizenships’ requiring subjectivity and agency and more inclusive conceptions. The main actors in democratic development have been affected by these challenges. Political parties are an important element in democracy but they have become an interest in their own right. A crisis of representation has emerged from growing social detachment of political parties from social cleavages as well as of elected representatives from the citizens. This had most dramatic effects on the Left, when left-wing parties have supported neoliberal reforms. Relying on expertise for the development of progressive policies is not a solution given the non-accountable power of science as well as the increasing challenges of privatization of knowledge-making, opacity of knowledge production and persistence of fundamental class imbalances in access to knowledge. Participatory channels of access to institutions have been opened to ‘ordinary citizens’ but, within neoliberalism, they are often based on individualist conceptions and do not address fundamental issues of inequalities. While citizens often call for direct participation, existing experiments rarely empower the citizens. While the judiciary has been seen as a surrogate for democratic participation for marginalized minority groups, its capacity for rights enforcement is limited by the expansion (in particular at international level) of a lex mercatoria as well as the use of courts in order to protect economic freedom from democratic dynamics. The rule of law has also been subverted by unequal access to the law and by the influence of money while the judiciary also has its own particular interests and corporate lawyers assume a brokerage function in globalized markets. On the other hand, in the control of political dissent, the state, rather than being weakened from globalization, increases its reach and power. The ‘war on terror’ has been used to challenge the rule of law by states of emergency as well as authoritarian drifts with attempts at imposing a permanent ‘state of exception’. On the other hand, progressive social movements have addressed growing inequalities and democratic crises by developing alternative visions of democracy, stressing participation over delegation and deliberation over majoritarian decision-making. Participatory and deliberative conceptions have been prefigured as well as elaborated in recent waves of protests. The consolidation of oppositional actors, however, faces challenges in the fragmentation of the potential social bases, the need to build a new collective identity as well as to establish channels of access to power. This has resulted from, but also triggered, the reduction in citizens’ entitlements and the weakening of the social contract upon which social progress depends
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