136 research outputs found
Roosting Behavior of the Grey-Cheeked Fulvetta Alcippe morrisonia Swinhoe in the Non-breeding Season
No full textTechnological Regimes and Firm Survival: Evidence across Sectors and over Time
Full text linkIn addition to the usual variables representing firm- and industry-specific features that impact the firm’s survival, this paper uses three R&D related variables to reflect two Schumpeterian technological regimes: creative destruction (the entrepreneurial regime) and creative accumulation (the routinized regime). After controlling for age, size, entry barriers, capital intensity, the profit margin, the concentration ratio, the profit-cost ratio and entry rates, the empirical results confirm the theoretical relationship between technological regimes and the survival rate of new firms: new firms are more likely to survive under the entrepreneurial regime. Moreover, this effect is larger within the younger cohorts of firms than within the older ones.Firm Survival, Technological Regimes, Taiwanese Manufacturing
Taiwan's Breeding Bird Survey reveals very few declining species
No full textMulti-species indicators (MSIs) have been useful tools for reflecting the state of taxa and ecosystems at global, regional, and national levels. However, most indicators are from Europe and North America, and there are few from the world's major tropical and subtropical biodiversity hotspots, often in large part because of insufficient data availability. We modelled the population trajectories of 107 regularly-occurring breeding bird species in Taiwan (100 native and seven introduced species) and developed MSIs for (i) forest, (ii) farmland, and (iii) introduced bird species based on the Taiwan Breeding Bird Survey dataset between 2011 and 2019. Individual population trajectories for 87 species did not show a significant change, those for 11 species grew significantly, and those for two species declined significantly. All MSIs show significant growth. Based on the phylogenetic generalised least squares (PGLS) results, the forest bird indicator increased somewhat more rapidly than the farmland bird indicator, perhaps reflecting very low rates of deforestation contrasting with more rapid land use change on farmlands in Taiwan. Some of the forest and farmland species, however, showed rapid declines, and most of these atypical decliners were common species or carnivores. Further, the PLGS results show that the introduced species indicator had more rapid growth than native species indicators, posing a potential risk for the integrity of native bird communities in the near future as well as compromising broader ecosystem intactness. Our study provides important information on bird population changes in subtropical Asia. The MSIs will be updated regularly and will be used to provide information to support conservation policies in Taiwan.Full Tex
Markets, Human Capital, and Inequality: Evidence from Rural China
Full text linkMarket reforms are generally credited with the rapid growth enjoyed by China's rural sector. This growth has not been without some cost, however, as inequality has also increased. Estimates suggest that the Gini rose from less than 0.20 to over 0.40 during this period. In this paper we go behind these numbers to explore the nature and causes of this inequality. To begin, we find that a considerable share of rural inequality is driven by local differences in household incomes, as opposed to regional income differences, that have been the focus of the previous literature. We then examine inter-household income differentials at the village level, exploring the links between education, market development, non- agricultural employment, and household income. To address these questions, we draw on a recently collected data set from Northeast China, that was collected by two of the authors in collaboration with Chinese colleagues in Hebei and Liaoning provinces in 1995. For purposes of comparison, we also draw on the Chinese Health and Nutrition Survey. We find that indeed, increasing rates of return to education and unevenly developed non-agricultural business opportunities contribute to the high levels of inequality in the countryside. Of most interest, however, is the implication that simultaneous improvements in educational attainment and off-farm market-development would allow more households to share in the rapid growth in rural China.
Structural Breaks, Regime Change and Asymmetric Adjustment: A Short and Long Run Global Approach to the Output/Unemployment Dynamics
Full text linkEven though the output and unemployment relation has always been a key theme in applied macroeconometrics research, the global hypothesis of modular short and long run dynamics assuming classic macroeconomic assumptions, is still to become a widely discussed subject in the field, and, therefore entails a large scope for further improvement, discussion and experimentation. Following recent advances in non linear bivariate estimation techniques this paper evaluates the joint hypotheses of endogenous growth, the natural rate hypothesis and asymmetric short run error correction. To tackle this global proposal a three step methodology, based on numeric grid search procedures is employed on data from nineteen OCDE countries. First, a numerical grid search is used to estimate linear trend output regimes with structural breaks and long run natural Unemployment rate regimes are endogenously obtained from these estimates. Finally, different grid search procedures, based on the original two step procedure for estimating linear cointegration models, are used to estimate the short run adjustment process assuming threshold vector error correction dynamics, following recent proposals on asymmetric Okun adjustment.Okun Law; Structural Change; Additive-Outlier Models; Bivariate Threshold Vector Error Correction Systems; Output/Unemployment Dynamics
A distributed channel allocation scheme for cellular network using intelligent software agents
No full textPhDAbstract not availabl
Site-specific function of Endonuclease G and CPS6 to enable vertebrate function in an invertebrate model
Full text link2021 Fall.Includes bibliographical references.The role of mitochondrial localized Endonuclease G (EndoG) remains relatively elusive. Studies have shown that EndoG has implications in mitochondrial DNA copy number, nuclear DNA cleavage during apoptosis, and oncogenesis; however, the mechanisms and pathways have yet to be determined. Our initial work investigates the nuclease activity of EndoG as well as its binding preference for duplex DNA and Holliday Junctions. It appears that EndoG and its C. elegans homolog, cps6, have slightly different functions in their in vivo systems, which has led us to query the structural modifications between the proteins. EndoG has been shown to have a preference for the 5-hydroxymethylcytosine (5hmC) epigenetic marker, an interesting feature due to the fact that invertebrate systems do not contain 5hmC in their epigenome. A key difference in the homologs arises in their DNA binding domain. The invertebrate model (cps6) contains two additional amino acids within this region that potentially allow for an alpha helix not seen in the vertebrate model to form. This alpha helix repositions a conserved cysteine in a way that it is pointed away from the active site in cps6, which could have consequences with regards to function. Our work investigates the addition/removal of this helix from the vertebrate and inveterate system to elucidate its role. In conjunction with the primary DNA binding site, there is a second site next to and orthogonal to the first. The vertebrate system contains multiple positively charged residues positioned to interact with the DNA backbone while the invertebrate contains two prolines that seem to be responsible for repositioning charges away from the site. We investigate the role of this secondary binding site as well as the importance of the invertebrate prolines. Overall, we propose a model to determine the role of EndoG in vivo utilizing the suite of protein mutations characterized herewithin
Towards a team-based, collaborative approach to embedding e-learning within undergraduate nursing programmes
No full textE-learning approaches are incorporated in many undergraduate nursing programmes but there is evidence to suggest that these are often piecemeal and have little impact on the wider, nurse education curriculum. This is consistent with a broader view of e-learning within the higher education (HE) sector, which suggests that higher education institutions (HEIs) are struggling to make e-learning a part of their mainstream delivery (HEFCE, 2005). This article discusses some of the challenges that face contemporary nurse education and seeks to account for reasons as to why e-learning may not be fully embedded within the undergraduate curriculum. These issues are considered within a wider debate about the need to align e-learning approaches with a shift towards a more student focused learning and teaching paradigm. The article goes on to consider broader issues in the literature on the adoption, embedding and diffusion of innovations, particularly in relation to the value of collaboration. A collaborative, team-based approach to e-learning development is considered as a way of facilitating sustainable, responsive and multidisciplinary developments within a field which is constantly changing and evolving
Estudio de la influencia de la morfología y de la distribución de tamaños de partícula del polvo en la obtención de aleaciones base Cu y base Ni mediante la tecnología MIM
Full text linkEn las últimas dos décadas, el procesado mediante moldeo por inyección de polvos metálicos (MIM) ha sido una tecnología que ha experimentado un notable crecimiento año tras año debido a que constituye una alternativa rentable para la fabricación de piezas de pequeño tamaño y difícil geometría. Sin embargo, una de sus mayores limitaciones como tecnología es el alto coste que presentan los polvos metálicos con morfología esférica y pequeño tamaño de partícula que se utilizan normalmente en esta ruta de procesado. En el presente trabajo de investigación se ha estudiado la influencia de la morfología del polvo metálico y de la distribución de tamaños de partícula del mismo sobre cada una de las etapas que constituyen el procesado MIM. El objetivo principal es determinar la viabilidad de la sustitución total o parcial del tipo de polvo que se utiliza actualmente (atomizado en gas) por otros tipos de polvo más económicos. Para llevar a cabo este estudio, se seleccionaron dos materiales metálicos cuyo procesado mediante MIM presentara interés industrial. Se eligió un bronce (90Cu/10Sn) y una superaleación base níquel (Inconel 718). Ambos materiales fueron mezclados con un ligante formado por polietileno de alta densidad (HDPE) y cera parafínica utilizando además, en el caso del Inconel 718, ácido esteárico como agente surfactante. Este sistema ligante multicomponente es económicamente asequible y su abastecimiento está garantizado en el tiempo por lo que constituye una solución adecuada para su aplicación industrial. En la fabricación de las mezclas polvo-ligante se han utilizado polvos de diferente geometría y distribuciones de tamaño de partícula distinta. Por un lado se busca reducir el precio del “feedstock” (mezcla polvo-ligante) y, por otro, aumentar el empaquetamiento para reducir la viscosidad de las mezclas consiguiendo de este modo aumentar la carga sólida y mejorar el control dimensional sobre los componentes. Medidas reológicas y del par de torsión permitieron evaluar el contenido de polvo óptimo de cada mezcla polvoligante para llevar a cabo el proceso de moldeo del material. Además, el estudio de diferentes parámetros reológicos como la viscosidad, el índice de flujo, la energía de activación y el esfuerzo umbral ha permitido determinar cómo influye la morfología y distribución de tamaños de partícula del polvo sobre su procesabilidad. Una vez determinados los contenidos de polvo óptimos en cada caso, se procedió a la fabricación de componentes en verde (formados por el polvo metálico y el ligante) mediante moldeo por inyección de las diferentes mezclas. Para realizar una inyección satisfactoria fue necesario optimizar parámetros como la temperatura, el volumen, la presión y el flujo de inyección de modo que las piezas obtenidas no presentaran defectos de fabricación y fueran lo suficientemente resistentes para soportar la manipulación necesaria en las etapas posteriores. Al mismo tiempo, se estudió la facilidad de procesado de cada mezcla relacionándola con las características del polvo utilizado en cada caso. A continuación, se intentó determinar cuáles eran las técnicas de eliminación del ligante más convenientes teniendo en cuenta los materiales y los sistemas ligantes utilizados. A través de la caracterización térmica (TGA, DSC) del sistema ligante y de los “feedstocks” fabricados, se definieron las condiciones más adecuadas para llevar a cabo el proceso y, del mismo modo que en los casos anteriores, se estudió cómo influyen las características del polvo en el proceso de eliminación. Finalmente, se realizó la sinterización de los materiales, determinando las condiciones óptimas del proceso. Las piezas obtenidas fueron estudiadas evaluando algunas propiedades físicas y mecánicas como la densidad, porosidad y la dureza. Tanto el proceso de sinterización como las propiedades finales fueron relacionados con las características del polvo de partida. ________________________________________________In the present Ph. D thesis, the influence of particle morphology and size distribution
of the powder on the different stages of Powder Injection Moulding process (PIM) has
been investigated. The aim of this work is to determine the optimal powder characteristics
to carry out the process, just as to study the viability of the total or partial replacing of the
gas atomised powder, nowadays used in this technology, with other kinds of more
economical powders.
The study was performed using different bronze (90Cu/10Sn) and superalloy Inconel
718 powders in order to fabricate powder-binder mixtures employing different particle
morphologies and particle size distributions.
The rheological properties determination of the powder-binder mixtures allowed
knowing the optimal solids loading for the green components fabrication through injection
moulding. Next, the more convenient conditions to carry out the binder elimination process
were established and sintering of the materials was performed under different
atmospheres and thermal cycles. Finally, the sintered components were characterized and
the results were compared having into account the features of the powder used for their
fabrication
Political Connections and Business Strategy: The Impact of Types and Destinations of Political Ties on Business Diversification in Closed and Open Political Economic
Full text linkThis paper studies how different types and destinations of connections between business leaders and political actors create strategic benefits in closed and open political economic systems. The analysis examines how political ties facilitate diversification by business groups in Taiwan between 1986 and 1998, before and after the country underwent extensive political and economic liberalization that led to changes in diffusion of power, tie accountability, and public scrutiny. We show that formal position interlocks with the dominant party or senior government officials provide the greatest strategic benefits in a closed political economic system, while informal social ties to a wider range of political actors provide greater strategic benefits when a political economic system becomes more open.
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