3,721 research outputs found
Scaffold Design Considerations for Soft Tissue Regeneration
Tissue engineering has emerged as a promising strategy for the replacement of degenerating or damaged tissues in vivo. Also known as regenerative medicine, integral to this therapeutic strategy is biomimetic scaffolds and the biomaterial structural components used to form them. In this study, three different biomaterial scaffolds for tissue engineering applications were fabricated: three-dimensional reverse embedded collagen scaffolds, polymer fusion printed polycaprolactone (PCL) scaffolds, and electrospun gelatin scaffolds. Three-dimensional collagen and PCL scaffolds promoted human adipose-derived stem/stromal cell (ASC) spreading, proliferation, and fibronectin deposition in vitro. Secondly, this study investigated the efficacy of exogenous galectin-3 delivery as a therapeutic in skin healing, given that galectin-3 has been implicated in several wound healing processes. Gelatin polymer blended with recombinant galectin-3 was electrospun into a protein delivery scaffold and employed in a murine model of cutaneous wound healing. Treatment of wounds with the galectin-3/gelatin scaffolds, or with topical galectin-3, did not enhance wound closure, re-epithelialization, or influence macrophage phenotypes in vivo
Revealing the role of past and current climate in shaping the distribution of two parapatric European bats, Myotis daubentonii and M. capaccinii
In this contribution, we aim at determining the role of climate in shaping the current and historical (Last Glacial Maximum and Middle Holocene) distributions of two parapatric bat species (Myotis daubentonii and Myotis capaccinii) in Europe, using ensemble Habitat Suitability Modelling (HSM). Model projection to current climatic conditions predicted distributions largely coherent with the ones observed for the two species in the study area. Temperature- and precipitation-linked variables well accounted for the observed parapatry of the two target species. Moreover, areas of co-occurrence turned out to be those where the main ecological needs concerning the most important range-limiting variables are met for both species. Model projections to past scenarios allowed us to hypothesize the effects of climatic oscillations over the distribution of the two species during the Late Pleistocene and Holocene. Extreme range contractions during the Last Glacial Maximum and the subsequent expansions during Middle Holocene were predicted, consistently with general patterns of post-glacial recolonization routes of many temperate bat species in Europe. Our findings are largely coherent with recent phylogeographic studies investigating the two target species, thus corroborating the validity of potential distribution scenarios obtained from the models and, more importantly, confirming the great influence that glacial cycles had in shaping the biogeography of the European fauna
Early correlates of error-related brain activity predict subjective timing of error awareness
Humans are remarkably reliable in detecting errors in their behavior. Whereas error awareness has been assumed to emerge not until 200–400 ms after an error, the so-called early error sensations refer to the subjective feeling of having detected an error even before the erroneous response was executed. Here, we collected electroencephalogram (EEG) to track how early error sensations are reflected in neural correlates of performance monitoring. Participants first had to perform a task, and then had to indicate whether an error has occurred and whether this error was detected before or after response execution. EEG results showed that early error sensations were associated with an earlier peak of the error-related negativity (Ne/ERN), a component of error-related brain activity that occurs briefly after the error response. This demonstrates that early error-related activity influences metacognitive judgments on the time course of error awareness, and thus contributes to error awareness
Are errors detected before they occur? Early error sensations revealed by metacognitive judgments on the timing of error awareness
Errors in choice tasks are not only detected fast and reliably, participants often report that they knew that an error occurred already before a response was produced. These early error sensations stand in contrast with evidence suggesting that the earliest neural correlates of error awareness emerge around 300 ms after erroneous responses. The present study aimed to investigate whether anecdotal evidence for early error sensations can be corroborated in a controlled study in which participants provide metacognitive judgments on the subjective timing of error awareness. In Experiment 1, participants had to report whether they became aware of their errors before or after the response. In Experiment 2, we measured confidence in these metacognitive judgments. Our data show that participants report early error sensations with high confidence in the majority of error trials across paradigms and experiments. These results provide first evidence for early error sensations, informing theories of error awareness
Politics and power in national REDD+ policy processes
National Strategy and Policy Options Maria Brockhaus Arild Angelsen ... depend on existing institutions and legal structures, current political and economic processes, the distribution of power and wealth, and the REDD+ actions appropriate to ..
Pro-poor land tenure and democratic governance. Discussion paper No. 3.Oslo: Oslo Governance Centre.
This discussion paper provides a review of how different forms of land tenure reform relate to decentralization and local governance, in theory and practice. It will guide readers who are familiar with decentralization and local governance approaches to understand the main issues and challenges posed by land tenure reforms to achieve pro-poor impact. Because land tenure reform assigns control over resources that are critical for both identity and livelihood, it will be contentious. It is, therefore, important to distinguish among four different types of land tenure reform and critically assess the political economy context and the type of decentralization as well as national-local governance relationships in which land tenure reform will be implemented. It is equally important to understand the implications of various land tenure reform types for democratic governance and social inclusion / cohesion
Rotational Mobility Analysis of the 3-RFR Class of Spherical Parallel Robots
none4noSpherical parallel manipulators (SPMs) are used to orient a tool in the space with three degrees of freedom exploiting the strengths of a multi-limb architecture.
On the other hand, the performance of parallel kinematics machines (PKMs) is often affected by the occurrence of different kinds of singular configurations.
The paper aims at characterizing a class of SPMs for which all singularities come to coincide and a single expression is able to describe all the singular configurations of the machines. The study is focused on a class of SPMs with 3-RFR topology (Revolute-Planar-Revolute pairs for each of the three limbs) addressing the mobility and singularity analysis by means of polynomial decomposition and screw theory. The neatness of the equations that are worked out, expressed in a robust formulation based on rotation invariants, allows a straightforward planning of singularity free tasks and simplifies the synthesis of dexterous machines.openCorinaldi, David; Carbonari, Luca; Palpacelli, Matteo-Claudio; Callegari, MassimoCorinaldi, David; Carbonari, Luca; Palpacelli, Matteo-Claudio; Callegari, Massim
Information networks and power: confronting the "wicked problem" of REDD+ in Indonesia
Reducing Emissions from Deforestation and Forest Degradation (REDD+) is a priority issue for forest and climate policy in Indonesia, and REDD+ policy-making activity has been characterized by considerable public consultation. Despite this engagement, discussions on REDD+ in Indonesia are reported to have remained top-down, a disconcerting pattern when adaptive governance and transformational change require cross-scale and cross-sectoral communication. Explicitly modeling the patterns of information exchange related to REDD+ can clarify these claims and help identify potential barriers to the transformational change needed to implement REDD+. We used data obtained through semistructured and structured interviews held in 2011 with representatives from a broad range of organizations (N = 64), formally or informally involved in the national REDD+ policy processes in Indonesia, to study REDD-related information exchange. Adopting a social network analysis approach, we found that (1) organizations perceived as most influential in REDD+ policy formulation, often, but not exclusively, those with institutional authority over particular aspects of REDD+, tend not to seek information from other actors and (2) organizations exchange information primarily within three clusters of similar organizations, with weak connections between clusters. This evidence suggests weak information exchange between the national government, national civil society, and transnational actors. We contend that the emergence of brokers able to connect these different clusters will be crucial for effective and inclusive REDD+ governance in Indonesia
The REDD+ policy arena in Vietnam: participation of policy actors
Reducing emissions from deforestation and degradation (REDD+) has gained increasing global attention because of its potential to reduce carbon emissions and improve forest governance. Reducing emissions from deforestation and degradation requires successful inclusive decision making and accountability. However, there have been limited empirical studies that examine the effectiveness of the current participatory mechanism used in REDD+. Our research analyzes the participation of policy actors in the development of the REDD+ instrument in Vietnam. We are interested in how the political context and the different interests of actors influence the degree of participation in national REDD+ policy decision making. We explored participation through the analysis of the mechanisms, e.g., how actors involve and participate in decision making, and dynamics of participation, e.g., highly centralized policy event vs. donor led event. The study aims to answer three research questions: (1) Who is involved in national REDD+ policy making and what are their interests in participating in core political events? (2) What level of participation do the different political actors have in core political events? and (3) To what extent do the outcomes, e.g., regulations and strategies, of REDD+ policy events incorporate different preferences of policy actors? Our findings highlighted the dominant role of government agencies in REDD+ policy making, which leaves limited political space for nonstate actors, e.g., NGOs and civil society organizations (CSOs), in Vietnam to exert an influence on the final policy outputs. Even in this highly centralized context, however, we found evidence to suggest that some political space in decision making is given to nonstate actors. Within this space, such actors are able to propose alternative policy options. Ensuring inclusive decision making and accountability in the Vietnam context requires a shift in current governance from traditional top-down approaches to a more participatory form of decision making
National REDD+ policy networks: from cooperation to conflict
Reducing emissions from deforestation and forest degradation (REDD+) is a financial mechanism aimed at providing incentives to reduce carbon emissions from forests and enhance carbon stocks. In most forest-rich developing countries, policy actors, i.e., state and nonstate as well as international and national, are designing national REDD+ policies. Actors’ interests and beliefs shape patterns of interactions, ranging from cooperation to conflict, and these interactions influence a country’s direction and progress in REDD+ policy formulation and implementation. We used a comparative policy network approach to analyze the power structures in national REDD+ policy domains in seven countries. We drew on the typology of power structures defined by two dimensions, namely the distribution of power in the policy arena and the dominant type of interaction, cooperative or conflictual, among actors, and we mapped the progress of national REDD+ decision-making processes against these power structures. We tested three hypotheses and found that (1) national ownership over the policy process is a prerequisite for progress. In addition, (2) the level of concentration of power in an actor group can facilitate progress in REDD+; however, particularly when concentration of power is high, progress will be possible only if the interests of the most powerful are aligned with the objectives of REDD+ and address the drivers of deforestation and forest degradation. Furthermore, (3) although cooperation is perceived as ideal in any collective decision-making setting, a certain level of conflict is necessary for progress in REDD+ decision making. This applies particularly in more advanced national REDD+ domains, where, following a honeymoon phase during which most policy actors embrace the broad idea of REDD+, policy decisions must deal with difficult realities associated with negotiating established business-as-usual interests, which entails high political costs
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