8 resultados para factor-augmented panel regressions

em Aston University Research Archive


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Pituitary adenylate cyclase-activating polypeptide (PACAP) functions as a neuroprotective factor through the PACAP type 1 receptor, PAC1. In a previous work, we demonstrated that nerve growth factor augmented PAC1 gene expression through the activation of Sp1 via the Ras/MAPK pathway. We also observed that PAC1 expression in Neuro2a cells was transiently suppressed during in vitro ischemic conditions, oxygen-glucose deprivation (OGD). Because endoplasmic reticulum (ER) stress is induced by ischemia, we attempted to clarify how ER stress affects the expression of PAC1. Tunicamycin, which induces ER stress, significantly suppressed PAC1 gene expression, and salubrinal, a selective inhibitor of the protein kinase RNA-like endoplasmic reticulum kinase signaling pathway of ER stress, blocked the suppression. In luciferase reporter assay, we found that two Sp1 sites were involved in suppression of PAC1 gene expression due to tunicamycin or OGD. Immunocytochemical staining demonstrated that OGD-induced transglutaminase 2 (TG2) expression was suppressed by salubrinal or cystamine, a TG activity inhibitor. Further, the OGD-induced accumulation of cross-linked Sp1 in nuclei was suppressed by cystamine or salubrinal. Together with cystamine, R283, TG2-specific inhibitor, and siRNA specific for TG2 also ameliorated OGD-induced attenuation of PAC1 gene expression. These results suggest that Sp1 cross-linking might be crucial in negative regulation of PAC1 gene expression due to TG2 in OGD-induced ER stress. © 2013 by The American Society for Biochemistry and Molecular Biology, Inc.

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This paper analyses the relationship between industrial total factor productivity and public capital across the 20 Italian administrative regions. It adds upon the existing literature in a number of ways: it analyses a longer period (1970-98); it allows for the role of human capital accumulation; it tests for the existence of a long-run relationship between total factor productivity and public capital (through previously suggested panel techniques) and for weak exogeneity of public capital; and it assesses the significance of public capital within a non-parametric set-up based on the Free Disposal Hull. The results confirm that public capital has a significant impact on the evolution of total factor productivity, particularly in the Southern regions. This impact is mainly ascribed to the core infrastructures (road and airports, harbours, railroads, water and electricity, telecommunications). Also, core infrastructures are weakly exogenous. © 2005 Regional Studies Association.

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FDI plays a key role in development, particularly in resource-constrained transition economies of Central and Eastern Europe with relatively low savings rates. Gains from technology transfer play a critical role in motivating FDI, yet potential for it may be hampered by a large technology gap between the source and host country. While the extent of this gap has traditionally been attributed to education, skills and capital intensity, recent literature has also emphasized the possible role of institutional environment in this respect. Despite tremendous interest among policy-makers and academics to understand the factors attracting FDI (Bevan and Estrin, 2000; Globerman and Shapiro, 2003) our knowledge about the effects of institutions on the location choice and ownership structure of foreign firms remains limited. This paper attempts to fill this gap in the literature by examining the link between institutions and foreign ownership structures. To the best of our knowledge, Javorcik (2004) is the only papers, which use firm-level data to analyse the role of institutional quality on an outward investor’s entry mode in transition countries. Our paper extends Javorcik (2004) in a number of ways: (a) rather than a cross-section, we use panel data for the period 1997-2006; (b) rather than a binary variable, we use the percentage foreign ownership as continuous variable; (c) we consider multi-dimensional institutional variables, such as corruption, intellectual property rights protection and government stability. We also use factor analysis to generate a composite index of institutional quality and see how stronger institutional environment could affect foreign ownership; (d) we explore how the distance between institutional environment in source and host countries affect foreign ownership in a host country. The firm-level data used includes both domestic and foreign firms for the period 1997-2006 and is drawn from ORBIS, a commercially available dataset provided by Bureau van Dijk. In order to examine the link between institutions and foreign ownership structures, we estimate four log-linear ownership equations/specifications augmented by institutional and other control variables. We find evidence that the decision of a foreign firm to either locate its subsidiary or acquire an existing domestic firm depends not only on factor cost differences but also on differences in institutional environment between the host and source countries.

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To investigate the technical feasibility of a novel cooling system for commercial greenhouses, knowledge of the state of the art in greenhouse cooling is required. An extensive literature review was carried out that highlighted the physical processes of greenhouse cooling and showed the limitations of the conventional technology. The proposed cooling system utilises liquid desiccant technology; hence knowledge of liquid desiccant cooling is also a prerequisite before designing such a system. Extensive literature reviews on solar liquid desiccant regenerators and desiccators, which are essential parts of liquid desiccant cooling systems, were carried out to identify their advantages and disadvantages. In response to the findings, a regenerator and a desiccator were designed and constructed in lab. An important factor of liquid desiccant cooling is the choice of liquid desiccant itself. The hygroscopicity of the liquid desiccant affects the performance of the system. Bitterns, which are magnesium-rich brines derived from seawater, are proposed as an alternative liquid desiccant for cooling greenhouses. A thorough experimental and theoretical study was carried out in order to determine the properties of concentrated bitterns. It was concluded that their properties resemble pure magnesium chloride solutions. Therefore, magnesium chloride solution was used in laboratory experiments to assess the performance of the regenerator and the desiccator. To predict the whole system performance, the physical processes of heat and mass transfer were modelled using gPROMS® advanced process modelling software. The model was validated against the experimental results. Consequently it was used to model a commercials-scale greenhouse in several hot coastal areas in the tropics and sub-tropics. These case studies show that the system, when compared to evaporative cooling, achieves 3oC-5.6oC temperature drop inside the greenhouse in hot and humid places (RH>70%) and 2oC-4oC temperature drop in hot and dry places (50%

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The themes of this thesis are that international trade and foreign direct investment (FDI) are closely related and that they have varying impacts on economic growth in countries at different stages of development. The thesis consists of three empirical studies. The first one examines the causal relationship between FDI and trade in China. The empirical study is based on a panel of bilateral data for China and 19 home countries/regions over the period 1984-98. The specific feature of the study is that econometric techniques designed specially for panel data are applied to test for unit roots and causality. The results indicate a virtuous procedure of development for China. The growth of China’s imports causes growth in inward FDI from a home country/region, which in turn causes the growth of exports from China to the home country/region. The growth of exports causes the growth of imports. This virtuous procedure is the result of China’s policy of opening to the outside world. China has been encouraging export-oriented FDI and reducing trade barriers. Such policy instruments should be further encouraged in order to enhance economic growth. In the second study, an extended gravity model is constructed to identify the main causes of recent trade growth in OECD countries. The specific features include (a) the explicit introduction of R&D and FDI as two important explanatory variables into an augmented gravity equation; (b) the adoption of a panel data approach, and (c) the careful treatment of endogeneity. The main findings are that the levels and similarities of market size, domestic R&D stock and inward FDI stock are positively related to the volume of bilateral trade, while the geographical distance, exchange rate and relative factor endowments, has a negative impact. These findings lend support to new trade, FDI and economic growth theories. The third study evaluates the impact of openness on growth in different country groups. This research distinguishes itself from many existing studies in three aspects: first, both trade and FDI are included in the measurement of openness. Second, countries are divided' into three groups according to their development stages to compare the roles of FDI and trade in different groups. Third, the possible problems of endogeneity and multicollinearity of FDI and trade are carefully dealt with in a panel data setting. The main findings are that FDI and trade are both beneficial to a country's development. However, trade has positive effects on growth in all country groups but FDI has positive effects on growth only in the country groups which have had moderate development. The findings suggest FDI and trade may affect growth under different conditions.

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This exploratory study is concerned with the integrated appraisal of multi-storey dwelling blocks which incorporate large concrete panel systems (LPS). The first step was to look at U.K. multi-storey dwelling stock in general, and under the management of Birmingham City Council in particular. The information has been taken from the databases of three departments in the City of Birmingham, and rearranged in a new database using a suite of PC software called `PROXIMA' for clarity and analysis. One hundred of their stock were built large concrete panel system. Thirteen LPS blocks were chosen for the purpose of this study as case-studies depending mainly on the height and age factors of the block. A new integrated appraisal technique has been created for the LPS dwelling blocks, which takes into account the most physical and social factors affecting the condition and acceptability of these blocks. This appraisal technique is built up in a hierarchical form moving from the general approach to particular elements (a tree model). It comprises two main approaches; physical and social. In the physical approach, the building is viewed as a series of manageable elements and sub-elements to cover every single physical or environmental factor of the block, in which the condition of the block is analysed. A quality score system has been developed which depends mainly on the qualitative and quantitative conditions of each category in the appraisal tree model, and leads to physical ranking order of the study blocks. In the social appraisal approach, the residents' satisfaction and attitude toward their multi-storey dwelling block was analysed in relation to: a. biographical and housing related characteristics; and b. social, physical and environmental factors associated with this sort of dwelling, block and estate in general.The random sample consisted of 268 residents living in the 13 case study blocks. Data collected was analysed using frequency counts, percentages, means, standard deviations, Kendall's tue, r-correlation coefficients, t-test, analysis of variance (ANOVA) and multiple regression analysis. The analysis showed a marginally positive satisfaction and attitude towards living in the block. The five most significant factors associated with the residents' satisfaction and attitude in descending order were: the estate, in general; the service categories in the block, including heating system and lift services; vandalism; the neighbours; and the security system of the block. An important attribute of this method, is that it is relatively inexpensive to implement, especially when compared to alternatives adopted by some local authorities and the BRE. It is designed to save time, money and effort, to aid decision making, and to provide ranked priority to the multi-storey dwelling stock, in addition to many other advantages. A series of solution options to the problems of the block was sought for selection and testing before implementation. The traditional solutions have usually resulted in either demolition or costly physical maintenance and social improvement of the blocks. However, a new solution has now emerged, which is particularly suited to structurally sound units. The solution of `re-cycling' might incorporate the reuse of an entire block or part of it, by removing panels, slabs and so forth from the upper floors in order to reconstruct them as low-rise accommodations.

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Using panel data pertaining to large Polish (non-financial) firms this paper examines the determinants of employment change during the period 1996-2002. Paying particular attention to the asymmetry hypothesis we investigate the impact of own wages, outside wages, output growth, regional characteristics and sectoral affiliation on the evolution of employment. In keeping with the 'right to manage' model we find that employment dynamics are not affected negatively by alternative wages. Furthermore, in contrast to the early transition period, we find evidence that employment levels respond to positive sales growth (in all but state firms). The early literature, (e.g. Kollo, 1998) found that labour hoarding lowered employment elasticities in the presence of positive demand shocks. Our findings suggest that inherited labour hoarding may no longer be a factor. We argue that the present pattern of employment adjustment is better explained by the role of insiders. This tentative conclusion is hinged on the contrasting behaviour of state and privatised companies and the similar behaviour of privatised and new private companies. We conclude that lower responsiveness of employment to both positive and negative changes in revenue in state firms is consistent with the proposition that rent sharing by insiders is stronger in the state sector.

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Editorial: The 2015 BCLA annual conference was another fantastic affair. It was the first time the conference was held in the beautiful city of Liverpool. The venue was great and the programme was excellent. The venue overlooked the River Mersey and many of the hotels were local boutique hotels. I stayed in one which was formerly the offices of White Star Liners—where the RMS Titanic was originally registered. The hotel decor was consistent with its historic significance. The BCLA gala dinner was held in the hugely impressive Anglican Cathedral with entertainment from a Beatles tribute band. That will certainly be a hard act to follow at the next conference in 2017. Brian Tompkins took the reigns as the new BCLA president. Professor Fiona Stapleton was the recipient of the BCLA Gold Medal Award. The winner of the poster competition was Dorota Szczesna-Iskander with a poster entitled ‘Dry Contact lens poor wettability and visual performance’. Second place was Renee Reeder with her poster entitled ‘Abnormal Rosacea as a differential diagnosis in corneal scarring’. And third place was Maria Jesus Gonzalez-Garcia with her poster entitled ‘Dry Effect of the Environmental Conditions on Tear Inflammatory Mediators Concentration in Contact Lens Wearers’. The photographic competition winner was Professor Wolfgang Sickenberger from Jena in Germany. The Editorial Panel of CLAE met at the BCLA conference for their first biannual meeting. The journal metrics were discussed. In terms of number of submissions of new papers CLAE seems to have plateaued after seeing a rapid growth in the number of submissions over the last few years. The increase over the last few years could be attributed to the fact that CLAE was awarded an impact factor for the first time in 2012. This year it seems that impact factors across nearly all ophthalmic related journals has dropped. This could in part be due to the fact that last year was a ‘Research Exercise Framework (REF) year for UK universities, where they are judged on quality of their research output. The next REF is in 2020 so we may see changes nearing that time. Looking at article downloads, there seems to be a continued rise in figures. Currently CLAE attracts around 85,000 downloads per year (this is an increase of around 10,000 per year for the last few years) and the 2015 prediction is 120,000! With this in mind and with other contributing factors too, the BCLA has decided to move to online delivery of CLAE to its members starting from issue 5 of 2015. Some members do like to flick through the pages of a hard copy of the journal so members will still have the option of receiving a hard copy through the post but the default journal delivery method will now be online. The BCLA office will send various alerts and content details to members email addresses. To access CLAE online you will need to log in via the BCLA web page, currently you then click on ‘Resources’ and then under ‘Free and Discounted Publications’ you will see CLAE. This actually takes you to CLAE’s own webpage (www.contactlensjournal.com) but you need to log in via the BCLA web page. The BCLA plans to change these weblinks so that from the BCLA web page you can link to the journal website much more easily and you have the choice of going directly into the general website for CLAE or straight to the current issue. In 2016 you will see an even easier way of accessing CLAE online as the BCLA will launch a CLAE application for mobile devices where the journal can be downloaded as a ‘flick-book’. This is a great way of bringing CLAE into the modern era where people access their information in newer ways. For many the BCLA conference was part of a very busy conference week as it was preceded by the International Association of Contact Lens Educators’ (IACLE) Third World Congress, held in Manchester on the 4 days before the BCLA conference. The first and second IACE World Congresses were held in Waterloo, Canada in 1994 and 2000 respectively and hosted by Professor Des Fonn. Professor Fonn was the recipient of the first ever IACLE lifetime achievement award. The Third IACLE World Congress saw more than 100 contact lens educators and industry representatives from around 30 countries gather in the UK for the four-day event, hosted by The University of Manchester. Delegates gained hands-on experience of innovations in teaching, such as learning delivery systems, the use of iPads in the classroom and for creating ePub content, and augmented and virtual reality technologies. IACLE members around the world also took part via a live online broadcast. The Third IACLE World Congress was made possible by the generous support of Sponsors Alcon, CooperVision and Johnson & Johnson Vision Care., for more information look at the IACLE web page (www.iacle.org).