Vascular endothelial growth factor promotes physical wound repair and is anti-apoptotic in primary distal lung epithelial and A549 cells

Objective: There is evidence to suggest a beneficial role for growth factors, including vascular endothelial growth factor (VEGF), in tissue repair and proliferation after injury within the lung. Whether this effect is mediated predominantly by actions on endothelial cells or epithelial cells is unknown. This study tested the hypothesis that VEGF acts as an autocrine trophic factor for human adult alveolar epithelial cells and that under situations of pro-apoptotic stress, VEGF reduces cell death. Design: In vitro cell culture study looking at the effects of 0.03% H2O2 on both A549 and primary distal lung epithelial cells.Measurement and Main Results: Primary adult human distal lung epithelial cells express both the soluble and membrane-associated VEGF isoforms and VEGF receptors 1 and 2. At physiologically relevant doses, soluble VEGF isoforms stimulate wound repair and have a proliferative action. Specific receptor ligands confirmed that this effect was mediated by VEGF receptor 1. In addition to proliferation, we demonstrate that VEGF reduces A549 and distal lung epithelial cell apoptosis when administered after 0.03% H2O2 injury. This effect occurs due to reduced caspase-3 activation and is phosphatidylinositol 3′–kinase dependent. Conclusion: In addition to its known effects on endothelial cells, VEGF acts as a growth and anti-apoptotic factor on alveolar epithelial cells. VEGF treatment may have potential as a rescue therapy for diseases associated with alveolar epithelial damage such as acute respiratory distress syndrome.

Concentration polarization model of spiral-wound membrane modules with application to batch-mode RO desalination of brackish water

Batch-mode reverse osmosis (batch-RO) operation is considered a promising desalination method due to its low energy requirement compared to other RO system arrangements. To improve and predict batch-RO performance, studies on concentration polarization (CP) are carried out. The Kimura-Sourirajan mass-transfer model is applied and validated by experimentation with two different spiral-wound RO elements. Explicit analytical Sherwood correlations are derived based on experimental results. For batch-RO operation, a new genetic algorithm method is developed to estimate the Sherwood correlation parameters, taking into account the effects of variation in operating parameters. Analytical procedures are presented, then the mass transfer coefficient models are developed for different operation processes, i.e., batch-RO and continuous RO. The CP related energy loss in batch-RO operation is quantified based on the resulting relationship between feed flow rates and mass transfer coefficients. It is found that CP increases energy consumption in batch-RO by about 25% compared to the ideal case in which CP is absent. For continuous RO process, the derived Sherwood correlation predicted CP accurately. In addition, we determined the optimum feed flow rate of our batch-RO system.

Dispersive Estimates of Solutions to the Wave Equation with a Potential in Dimensions Two and Three

2000 Mathematics Subject Classification: 35L15, 35B40, 47F05.

A Bimodality Test in High Dimensions

We present a test for identifying clusters in high dimensional data based on the k-means algorithm when the null hypothesis is spherical normal. We show that projection techniques used for evaluating validity of clusters may be misleading for such data. In particular, we demonstrate that increasingly well-separated clusters are identified as the dimensionality increases, when no such clusters exist. Furthermore, in a case of true bimodality, increasing the dimensionality makes identifying the correct clusters more difficult. In addition to the original conservative test, we propose a practical test with the same asymptotic behavior that performs well for a moderate number of points and moderate dimensionality. ACM Computing Classification System (1998): I.5.3.

Local Energy Decay in Even Dimensions for the Wave Equation with a Time-Periodic Non-Trapping Metric and Applications to Strichartz Estimates

2000 Mathematics Subject Classification: 35B40, 35L15.

Wound healing studies and interfacial phenomena:use and relevance of the corneal model

The interaction of the wound dressing as a biomaterial with the wound bed is the central issue of this chapter. The interfacial phenomenon that encompasses the biological and biochemical consequences that arise when a biomaterial is introduced to a host biological environment is discussed. A great deal can be learned from observations arising from the behaviour of biomaterials at other body sites; one particularly relevant body site in the context of wound healing is the anterior eye. The cornea, tear film and posterior surface of the contact lens provide an informative model of the parallel interface that exists between the chronic wound bed, wound fluid and the dressing biomaterial. © 2011 Woodhead Publishing Limited All rights reserved.

Sztochasztikus csődjátékok - avagy hogyan osszunk szét egy bizonytalan méretű tortát? = Stochastic bankruptcy games. How can a cake of uncertain dimensions be divided?

A kooperatív játékelmélet egyik legjelentősebb eredménye, hogy számos konfliktushelyzetben stabil megoldást nyújt. Ez azonban csak statikus és determinisztikus környezetben alkalmazható jól. Most megmutatjuk a mag egy olyan kiterjesztését - a gyenge szekvenciális magot -, amely képes valós, dinamikus, bizonytalan környezetben is eligazítást nyújtani. A megoldást a csődjátékok példájára alkalmazzuk, és segítségével megvizsgáljuk, hogy a pénzügyi irodalom ismert elosztási szabályai közül melyek vezetnek stabil, fenntartható eredményre. _______ One of the most important achievements of cooperative game theory is to provide a stable solution to numerous conflicts. The solutions it presents, on the other hand, have been limited to situations in a static, deterministic environment. The paper examines how the core can be extended to a more realistic, dynamic and uncertain scenario. The bankruptcy games studied are ones where the value of the estate and of the claims are stochastic, and a Weak Sequential Core is used as the solution concept for them. The author tests the stability of a number of well known division rules in this stochastic setting and finds that most are unstable, except for the Constrained Equal Awards rule, which is the only one belonging to the Weak Sequential Core.

The cultural and geopolitical dimensions of nation-building in the Ukraine

Ukraine belongs among those young countries where the beginnings of democratisation and nation-building approximately coincided. While the development of nation states in Central Europe was usually preceded by the development of nations, the biggest dilemma in the Ukraine is whether a nation-state programme — parallel to the aim of state-building — is able to bring unfinished nation-building to completion. Ukraine sways between the EU and Russia with enormous amplitude. The alternating orientation between the West and the East can be ascribed to superpower ambitions reaching beyond Ukraine. Eventually, internal and external determinants are intertwined and mutually interact with one another. The aim of the paper is to explain the dilemmas arising from identity problems behind the Ukraine’s internal and external orientation.

A hazai kis- és közepes vállalatok szociokulturális beállítódása a hofstede-dimenziók mentén = The socio-cultural attitudes of the Hungarianc small and medium enterprises along the Hofstede dimensions

A kis- és közepes vállalkozások (KKV-k) kutatása viszonylag új, és emiatt meglehetősen feltáratlan terület, bár a megjelenő tudományos cikkek és eredmények száma és minősége évről évre jól érzékelhetően nő (Collinson – Shaw, 2001). A KKV-kutatások igen fontos sajátossága továbbá, hogy kifejezetten interdiszciplináris terület, megközelíthető a menedzsment, az innovációkutatás, a marketing, a szervezetszociológia, de akár a pszichológia felől is. Több kutatás is felveti a szociokulturális háttér jelentőségének kérdését KKV-k esetében. A szerzők kutatásuk során kvantitatív felmérést végeztek 200 vállalkozó körében a Hofstedeskála (Hofmeister et al., 2008) felhasználásával, melynek eredményeként kiderült, hogy a KKV-vezetők beállítódása jelentősen különbözik mind a hazai nagyvállalati vezetőktől, mind az általános lakosságtól. Jelen tanulmányunkban bemutatjuk azokat a Hofstede-dimenziókat, amelyek mentén karakteres különbségek jelentkeztek a vállalkozók és a nagyvállalati vezetők, valamint a társadalom összessége között. Az eredmények alapján határozottan kirajzolódnak olyan „vállalkozói” gondolkodásmódbeli sajátosságok, mint a nagyobb versenyszellem, a közvetlenebb, kevésbé hierarchikus működési stílus, a rendkívül erős, rövid távú orientáció, valamint a kockázatvállalás rendhagyóan alacsony foka. _____ Although there has been an increasing academic attention towards small and medium-sized enterprises, it is still a novel research area with a number of unanswered questions. It is also an especially interdisciplinary field as it can be approached from various viewpoints such as management, innovation, marketing, organization sociology or even psychology. Different academic disciplines have studied the influence of socio-cultural factors and concluded that they are relevant aspects of entrepreneurial activity. This paper presents the results of the authors’ quantitative research which aimed at finding patterns in the software of the minds of SME managers where they applied Hofstede’s cultural scale (Hofmeister et al., 2008). Drawing upon data from 200 Hungarian SMEs, the results indicate they have different attitude and way of thinking compared to large company managers and to the general Hungarian population. This paper points out the relevant Hofstede dimensions where significant differences have been revealed. The main finding of the study is that managers of small and medium businesses have a special mindset which can be characterized with higher level competitiveness, more direct and less hierarchic operation, extremely high level of short term orientation and low level of risk taking

Thinking in three dimensions: Exploring students' geometric thinking and spatial ability with the Geometer's Sketchpad

Current reform initiatives recommend that geometry instruction include the study of three-dimensional geometric objects and provide students with opportunities to use spatial skills in problem-solving tasks. Geometer's Sketchpad (GSP) is a dynamic and interactive computer program that enables the user to investigate and explore geometric concepts and manipulate geometric structures. Research using GSP as an instructional tool has focused primarily on teaching and learning two-dimensional geometry. This study explored the effect of a GSP based instructional environment on students' geometric thinking and three-dimensional spatial ability as they used GSP to learn three-dimensional geometry. For 10 weeks, 18 tenth-grade students from an urban school district used GSP to construct and analyze dynamic, two-dimensional representations of three-dimensional objects in a classroom environment that encouraged exploration, discussion, conjecture, and verification. The data were collected primarily from participant observations and clinical interviews and analyzed using qualitative methods of analysis. In addition, pretest and posttest measures of three-dimensional spatial ability and van Hiele level of geometric thinking were obtained. Spatial ability measures were analyzed using standard t-test analysis. ^ The data from this study indicate that GSP is a viable tool to teach students about three-dimensional geometric objects. A comparison of students' pretest and posttest van Hiele levels showed an improvement in geometric thinking, especially for students on lower levels of the van Hiele theory. Evidence at the p < .05 level indicated that students' spatial ability improved significantly. Specifically, the GSP dynamic, visual environment supported students' visualization and reasoning processes as students attempted to solve challenging tasks about three-dimensional geometric objects. The GSP instructional activities also provided students with an experiential base and an intuitive understanding about three-dimensional objects from which more formal work in geometry could be pursued. This study demonstrates that by designing appropriate GSP based instructional environments, it is possible to help students improve their spatial skills, develop more coherent and accurate intuitions about three-dimensional geometric objects, and progress through the levels of geometric thinking proposed by van Hiele. ^

The multiple dimensions of political trust in democratic Argentina

Why do Argentines continue to support democracy despite distrusting political institutions and politicians? Support for democracy is high even though performance of the regime is poor. One would suspect that poor economic and political performance would open the door for military intervention given the history of Argentina. What changed? What explains variance across the multiple dimensions of political trust, such as trust in the regime, trust in political institutions, and trust in politicians? This dissertation is a case study of political culture through public opinion exploring the multiple dimensions of political trust in Argentina during the 1990s. ^ Variance across the different dimensions of political trust may be an indicator of the rise of a new type of citizens called "critical citizens." Critical citizens are citizens who criticize the regime to obtain democratic reforms but support the ideals of democracy. In established democracies, the rise of critical citizens is explained by a shift in individuals' value priorities towards postmaterialism. Postmaterialism is a cultural change in the direction of values that emphasize self-realization and individual well-being. Postmaterialism influences various social and political attitudes. ^ Because Argentina is experiencing a cultural change and a rise of critical citizens similar to more advanced societies, the theory of postmaterialism generated the main hypothesis to explain the multiple dimensions of political trust. This dissertation also tested an alternative explanation: the multiple dimensions of political trust responded instead to citizens' evaluations of performance. Ultimately, postmaterialism explained trust in the political regime and trust in the political institutions. Contrary to expectations, postmaterialism did not explain trust in the political elites or politicians. Trust in politicians was better explained by the alternative hypothesis, performance. ^ The main method of research was the statistical method supplemented with the comparative method when data were available. Two main databases were used: the World Values Surveys and the Latinobarometer. ^

A mixed method study of organizational culture dimensions of community college faculty library use and perceptions

Because past research has shown faculty as the driving force affecting student academic library use, librarians have tried for decades to engage classroom faculty in library activities. Nevertheless, a low rate of library use by faculty on behalf of their students persists. This study investigated the organizational culture dimensions affecting library faculty demand at a community college. The study employed a sequential quantitative-qualitative research design. A random sample of full-time faculty at a large urban community college responded to a 46-item survey. The survey data showed strong espoused support (84%) for the use of library-based materials but a much lower incidence of putting this construct into practice (46%). Interviews were conducted with 11 full-time faculty from two academic groups, English-Humanities and Engineering-Math-Science. These groups were selected because the survey data resulted in statistically significant differences between the groups pertaining to several key variables. These variables concerned the professors' perceptions of the importance of library research in their discipline, the amount of time spent on the course textbook during a term, the frequency of conversations about the library in the academic department, and the professors' ratings of the librarians' skill in instruction related to the academic discipline. All interviewees described the student culture as the predominant organizational culture at Major College. Although most interview subjects held to high information literacy standards in their courses, others were less convinced these could be realistically practiced, based on a perception of students' poor academic skills, lack of time for students to complete assignments due to their commuter and family responsibilities, and the need to focus on textbook content. Recommended future research would involve investigation of methods to bridge the gap between high espoused value toward information literacy and implementation of information-literate coursework.

Control of MNC environmental performance and the challenges of subsidiary network dimensions

The trend of green consumerism and increased standardization of environmental regulations has driven multinational corporations (MNCs) to seek standardization of environmental practices or at least seek to be associated with such behavior. In fact, many firms are seeking to free ride on this global green movement, without having the actual ecological footprint to substantiate their environmental claims. While scholars have articulated the benefits from such optimization of uniform global green operations, the challenges for MNCs to control and implement such operations are understudied. For firms to translate environmental commitment to actual performance, the obstacles are substantial, particularly for the MNC. This is attributed to headquarters' (HQ) control challenges (1) in managing core elements of the corporate environmental management (CEM) process and specifically matching verbal commitment and policy with ecological performance and by (2) the fact that the MNC operates in multiple markets and the HQ is required to implement policy across complex subsidiary networks consisting of diverse and distant units. Drawing from the literature on HQ challenges of MNC management and control, this study examines (1) how core components of the CEM process impact optimization of global environmental performance (GEP) and then uses network theory to examine how (2) a subsidiary network's dimensions can present challenges to the implementation of green management policies. It presents a framework for CEM which includes (1) MNCs' Verbal environmental commitment, (2) green policy Management which guides standards for operations, (3) actual environmental Performance reflected in a firm's ecological footprint and (4) corporate environmental Reputation (VMPR). Then it explains how an MNC's key subsidiary network dimensions (density, diversity, and dispersion) create challenges that hinder the relationship between green policy management and actual environmental performance. It combines content analysis, multiple regression, and post-hoc hierarchal cluster analysis to study US manufacturing MNCs. The findings support a positive significant effect of verbal environmental commitment and green policy management on actual global environmental performance and environmental reputation, as well as a direct impact of verbal environmental commitment on green policy management. Unexpectedly, network dimensions were not found to moderate the relationship between green management policy and GEP.

The Mature Market: Underlying Dimensions and Group Differences of a Potential Market for the Hotel Industry

The mature market, defined as age 55 and up and consisting of approximately 64 million Americans, is expected to increase. Studies show that this group travels more frequently, travels greater distances, and stays longer. The authors seek to determine if underlying dimensions exist for the mature individual with regard to the selection criteria for lodging when traveling for pleasure, and to determine if differences exist between various demographic subsegments of this market with regard to these underlying dimensions.

Dimensions of gender relations and reproductive health inequity perceived by female undergraduate students in the Mekong Delta of Vietnam: a qualitative exploration

Introduction Increasing evidence indicates that gender equity has a significant influence on women’s health; yet few culturally specific indicators of gender relations exist which are applicable to health. This study explores dimensions of gender relations perceived by female undergraduate students in southern Vietnamese culture, and qualitatively examines how this perceived gender inequity may influence females’ sexual or reproductive health. Methods Sixty-two female undergraduate students from two universities participated in eight focus group discussions to talk about their perspectives regarding national and local gender equity issues. Results Although overall gender gaps in the Mekong Delta were perceived to have decreased in comparison to previous times, several specific dimensions of gender relations were emergent in students’ discussions. Perceived dimensions of gender relations were comparable to theoretical structures of the Theory of Gender and Power, and to findings from several reports describing the actual inferiority of women. Allocation of housework and social paid work represented salient dimensions of labor. The most salient dimension of power related to women in positions of authority. Salient dimensions of cathexis related to son preference, women’s vulnerability to blame or criticism, and double standards or expectations. Findings also suggested that gender inequity potentially influenced women’s sexual and reproductive health as regards to health information seeking, gynecological care access, contraceptive use responsibility, and child bearing. Conclusion Further investigations of the associations between gender relations and different women’s sexual and reproductive health outcomes in this region are needed. It may be important to address gender relations as a distal determinant in health interventions in order to promote gender-based equity in sexual and reproductive health.