Testing a global city hypothesis : an assessment of polarization across US cities

Social polarization is perhaps most evident within the world's large cities where we can easily observe stark contrasts between wealth and poverty. A world city theoretical perspective has emerged that associates large cities importance in a global network of cities to the degree of internal polarization within these cities. The research reported here locates 57 large US cities within this world city hierarchy and then empirically examines the hypothesized positive association between global centrality and social polarization using a multivariate, cross-city analysis. The findings are mixed, with some evidence that global centrality increases income polarization, but only in the context of higher levels of immigration. There is no evidence that a city's centrality affects occupational polarization. We conclude by suggesting implications for the world city literature and future research

Do e-shopping attitudes mediate the effect of the built environment on online shopping frequency of e-shoppers?

It is widely acknowledged that e-shopping has considerable effects on e-shoppers’ travel behavior. Therefore, it is valuable to investigate the built environment effects on online shopping, which can help clarify whether land use policy is effective to manage online shopping and further moderate travel demand. However, this issue has not been fully investigated in prior research. In particular, some existing studies fail to identify a significant link between the built environment and online shopping. One of the possible reasons is that the indirect effects of the built environment on e-shopping through e-shopping attitudes are rarely considered. Against this backdrop, considering the mediating role of e-shopping attitudes, this paper aims to explore the influence of the built environment on the frequency of e-shopping for clothes and shoes, food and drinks, cosmetics, and electronics. Data used in this study are acquired from 675 face-to-face interviews with online buyers in Chengdu, China, and the Structural Equation Modeling method is employed. The outcomes show that higher residential density has a positive impact on online shopping frequency. Higher accessibility to metro stations has an indirect and negative influence on e-shopping frequency through pro-e-shopping attitudes. In contrast, mediated by e-shopping attitudes, higher accessibility to bus stations has an indirect and positive impact on online shopping frequency. The mediating role of attitudes provides a possible explanation for the influences of transportation accessibility on e-shopping frequency. Land use policies seem influential in online shopping attitudes and frequency, and thus moderate e-shoppers’ travel demand

The influence of ride-hailing on travel frequency and mode choice

Using data derived from 597 face-to-face interviews with ride-hailing users in Chengdu (China), we examined the influence of ride-hailing on travel frequency and mode choice and further analyzed what the main determinants for these are. The results indicate that 16.8% of the respondents increase their frequency of trips because of the adoption of ride-hailing services, suggesting a complementary effect of ride-hailing on travel. Meanwhile, the use of traditional travel modes is considerably substituted by ride-hailing services. Particularly, around half of the respondents indicated a substitution of ride-hailing for sustainable modes (i.e., public transit, cycling, and walking), which may thus generate environmental problems (e.g., increasing greenhouse gas emissions). Additionally, regression outcomes show that higher accessibility to bus stations is negatively correlated with the shift from sustainable modes to ride-hailing. Therefore, optimizing the access to bus facilities may be effective to cope with potential transportation problems posed by ride-hailing

How to cope with mobility expectations in academia: individual travel strategies of tenured academics at Ghent University, Flanders

The production and exchange of knowledge are inextricably linked to different compulsions to corporeal proximity and therefore travel. As primary producers and transferors of knowledge, academics are no exception to this rule, and their compulsions seem to be further propelled by institutional discourses regarding the alleged virtues of “internationalization.” Tenured academics, moreover, have a high degree of independence and can therefore easily choose how to cope with compulsions and constraints to internationalize. However, the business-travel literature has paid scant attention to academics and their individual contexts. In an effort to rectify this situation, this paper explores a travel dataset of tenure-track academics (N=870) working at Ghent University. The insights emerging from this analysis are then contextualized by complementing them with in-depth interviews of tenured academics (N=23) at the same institution. This paper argues, first, that varying compulsions and constraints at home and abroad lead to distinct non-travel and travel-intensive academic roles. And second, that academics who have difficulties coping, try to rationalize their corporeal travel behaviour and their mobility behaviour to meet the needs and expectations to internationalize. These strategies give an indication of how travel-related working practices can become more efficient and sustainable in the future

Filling some black holes: modeling the connection between urbanization, infrastructure, and global service intensity

This empirical article combines insights from previous research on the level of knowledge-intensive service in metropolitan areas with the aim to develop an understanding of the spatial structure of the global service economy. We use a stepwise regression model with the Globalization and World Cities research network's measure of globalized service provisioning as the dependent variable and a range of variables focusing on population, infrastructure, urban primacy, and national regulation as independent variables. The discussion of the results focuses on model parameters as well as the meaning of outliers and is used to explore some avenues for future research

Relationship between spatial proximity and travel-to-work distance : the effect of the compact city

In this paper, an assessment is made of the relationship between selected aspects of spatial proximity (density, diversity, minimum commuting distance, jobs-housing balance and job accessibility) and reported commuting distances in Flanders (Belgium). Results show that correlations may depend on the considered trip end. For example, a high residential density, a high degree of spatial diversity and a high level of job accessibility are all associated with a short commute by residents, while a high job density is associated with a long commute by employees. A jobs-housing balance close to one is associated with a short commute, both by residents and by employees. In general, it appears that the alleged sustainability benefits of the compact city model are still valid in a context of continuously expanding commuting trip lengths

Phenotype and envelope gene diversity of nef-deleted HIV-1 isolated from long-term survivors infected from a single source

<p>Abstract</p> <p>Background</p> <p>The Sydney blood bank cohort (SBBC) of long-term survivors consists of multiple individuals infected with attenuated, <it>nef</it>-deleted variants of human immunodeficiency virus type 1 (HIV-1) acquired from a single source. Long-term prospective studies have demonstrated that the SBBC now comprises slow progressors (SP) as well as long-term nonprogressors (LTNP). Convergent evolution of <it>nef </it>sequences in SBBC SP and LTNP indicates the <it>in vivo </it>pathogenicity of HIV-1 in SBBC members is dictated by factors other than <it>nef</it>. To better understand mechanisms underlying the pathogenicity of <it>nef</it>-deleted HIV-1, we examined the phenotype and <it>env </it>sequence diversity of sequentially isolated viruses (n = 2) from 3 SBBC members.</p> <p>Results</p> <p>The viruses characterized here were isolated from two SP spanning a three or six year period during progressive HIV-1 infection (subjects D36 and C98, respectively) and from a LTNP spanning a two year period during asymptomatic, nonprogressive infection (subject C18). Both isolates from D36 were R5X4 phenotype and, compared to control HIV-1 strains, replicated to low levels in peripheral blood mononuclear cells (PBMC). In contrast, both isolates from C98 and C18 were CCR5-restricted. Both viruses isolated from C98 replicated to barely detectable levels in PBMC, whereas both viruses isolated from C18 replicated to low levels, similar to those isolated from D36. Analysis of <it>env </it>by V1V2 and V3 heteroduplex tracking assay, V1V2 length polymorphisms, sequencing and phylogenetic analysis showed distinct intra- and inter-patient <it>env </it>evolution.</p> <p>Conclusion</p> <p>Independent evolution of <it>env </it>despite convergent evolution of <it>nef </it>may contribute to the <it>in vivo </it>pathogenicity of <it>nef</it>-deleted HIV-1 in SBBC members, which may not necessarily be associated with changes in replication capacity or viral coreceptor specificity.</p

Different susceptibility of osteosarcoma cell lines and primary cells to treatment with oncolytic adenovirus and doxorubicin or cisplatin

Despite improvements in treatment regimens for osteosarcoma (OS) patients, survival rate has not increased over the last two decades. New treatment modalities are therefore warranted. Preclinical results with conditionally replicative adenoviruses (CRAds) to treat OS are promising. One type of CRAd that was effective against OS cells is Ad5-Δ24RGD. In other types of cancer, CRAds have been shown to interact synergistically with chemotherapeutic agents. Chemotherapy for OS often includes doxorubicin and cisplatin. Therefore, we explored combination treatment of OS cell lines and primary OS cell cultures with Ad5-Δ24RGD and doxorubicin or cisplatin. On OS cell lines, combination treatment was additive to synergistic. Surprisingly, however, on seven of eight primary OS samples no such combination effects were observed. In contrast, in many cases chemotherapy even inhibited CRAd-mediated cell killing. The inhibitory effect of doxorubicin on Ad5-Δ24RGD in primary OS cells appeared to correlate with slow cell growth rate; reduced viral replication and absence of chemotherapy-induced G2 cell cycle arrest. Our results point to the possibility that, at least for OS, virotherapy and chemotherapy should best not be performed simultaneously. In general, our work underscores the importance of testing new genetic anticancer agents and treatment regimens on primary cancer specimens