Uneven Diffusion Research Articles

PsasM2I, a type II restriction-modification system in Pseudomonas savastanoi pv. savastanoi: differential distribution of carrier strains in the environment and the evolutionary history of homologous RM systems in the Pseudomonas syringae complex.

A type II restriction-modification system was found in a native plasmid of Pseudomonas savastanoi pv. savastanoi MLLI2. Functional analysis of the methyltransferase showed that the enzyme acts by protecting the DNA sequence CTGCAG from cleavage. Restriction endonuclease expression in recombinant Escherichia coli cells resulted in mutations in the REase sequence or transposition of insertion sequence 1A in the coding sequence, preventing lethal gene expression. Population screening detected homologous RM systems in other P. savastanoi strains and in the Pseudomonas syringae complex. An epidemiological survey carried out by sampling olive and oleander knots in two Italian regions showed an uneven diffusion of carrier strains, whose presence could be related to a selective advantage in maintaining the RM system in particular environments or subpopulations. Moreover, carrier strains can coexist in the same orchards, plants, and knot tissues with non-carriers, revealing unexpected genetic variability on a very small spatial scale. Phylogenetic analysis of the RM system and housekeeping gene sequences in the P. syringae complex demonstrated the ancient acquisition of the RM systems. However, the evolutionary history of the gene complex also showed the involvement of horizontal gene transfer between related strains and recombination events.

Geographies of the Book: Review and Prospect

AbstractThis paper traces the origins and recent history of the geography of the book: an interdisciplinary focus of study for geographers, book historians and historians of science. In describing this field's twin concern with geography in books and with the geography of books, the paper examines the ways in which printed texts matter to the study of geography's discursive and disciplinary histories and the contributions that geography, in turn, can make to explaining the circulation and reception of knowledge in print. Through an attention to the making and movement of texts, the paper examines how questions of geography inform understandings of the uneven diffusion and varied reception of knowledge and ideas. In addressing geography's print culture, and in examining geographies of reading, the paper reflects on the significance of books to the making of geographical knowledge and to the significance of geography in accounting for the making of textual meaning.

Key issues in the development of mobile telephony in Botswana (1998–2011): An empirical investigation

This article explored the key issues in the development of mobile telephony in Botswana from 1998 to 2011. The study has shown that as a developing country, Botswana has done well to develop and structurally position the mobile telephony sector for the benefit of its citizens. This is evidenced by the high rate of subscription of mobile telephony countrywide and continuous attempts by the government to network under-served communities. However, the sector has been left in the hands of a quasi-governmental corporation and private individual businessmen. In addition, there is serious competition for subscribers amongst network operators, uneven diffusion of network technologies and inadequate communication signal in some remote areas. Therefore, this study argues for additional reforms, with a view to strengthening and positioning the sector for effective use in order to deliver social services and increase diversification of the economy.

South Park boys and Sex and the City women: Television trade, narrowcasting and the export of gender categories

This article analyses the export of the gendered ‘demographic logics’ of American television to four European countries: France, Italy, the Netherlands and Poland. As American and (later) European television landscapes have become increasingly fragmented, television targets increasingly specific audiences. Through interviews with cultural intermediaries and document and website analysis, three gendered categories were found representing central ‘target audiences’ for today’s narrowcasting that came to Europe from Hollywood: the housewife, the Sex and the City woman, and the South Park boy. This article traces the emergence of these categories, and their uneven diffusion in European television landscapes, highlighting the dynamics of transnational diffusion of cultural categories. It shows how gendered audience categorizations provide a strategic site to employ the notoriously elusive concept of intersectionality in actual empirical analysis. This analysis of imported gendered categories underscores the similarity between the logic of narrowcasting and the analytical stance proposed by intersectionality theory, allowing us to critically analyse the politics of narrowcasting.

Unexpected Precipitation of a Re-Rich Phase in Single Crystal Superalloy CMSX-4 during Thermal Exposure

A Re-rich phase (up to 85.40% wt.Re) was occasionally found in a single crystal superalloy during thermal exposure. Interestingly, this phase is located in front of the dendrite periphery in the interdendritic region, while the Re is segregated in the dendrite core. Formation of this phase was suggested to relate to the unusual accumulation of the Re resulting from the uneven diffusion process of Re. Appearance of this phase may imply the preference of forming Re-Re atomic bond in the superalloys.

Hydrogel Membrane Improves Batch‐to‐Batch Reproducibility of an Enzymatic Glucose Biosensor

AbstractA permselective membrane is a critical component that defines the linear detection limits, the sensitivity, and thus the ultimate efficacy of an enzymatic biosensor. Although membranes like epoxy‐polyurethane (epoxy‐PU) and Nafion are widely used and provide the desired glucose detection limits of 2 to 30 mM, both the within batch and batch‐to‐batch variability of sensors that use these materials is a concern. The hypothesis for this study was that a crosslinked hydrogel would have a sufficiently uniform porosity and hydrophilicity to address the variability in sensor sensitivity. The hydrogel was prepared by crosslinking di‐hydroxyethyl methacrylate, hydroxyethyl methacrylate and N‐vinyl pyrrolidone with 2.5 mol% ethylene glycol dimethacrylate using water soluble initiators – ammonium persulfate and sodium metabisulfite under a nitrogen atmosphere. The hydrogel was applied to the sensor by dip coating during polymerisation. Electrochemical measurements revealed that the response characteristics of sensors coated with this membrane are highly consistent. Scanning electrochemical microscopy (SECM) was used to spatially resolve glucose diffusion through the membrane by measuring the consequent H2O2 release and compared with an epoxy‐PU membrane. Hydrogen peroxide measurements using SECM revealed that the epoxy‐PU membranes had uneven lateral diffusion profiles compared to the uniform profile of the hydrogel membranes. The uneven diffusion profiles of epoxy‐PU membranes are attributed to a fabrication method that results in uneven membrane properties, while the uniform diffusion profiles of the hydrogel membranes are primarily dictated by their uniform pore size.

Production technologies and financial performance: The effect of uneven diffusion among competitors

We explore the impact of a production technology on financial performance from the perspectives of technology diffusion and competitive strategy theory. We analyse how diffusion at firm and market levels influences the returns from the technology. We suggest that firm heterogeneity in the level of technology use leads to competitive advantages for relatively intensive adopters. We empirically test our propositions through the analysis of the diffusion of the Automated Teller Machine among Spanish savings banks between 1986 and 2004. Our results show that it is not the absolute but the relative level of use that drives the impact of the technology on profitability. Furthermore, as the technology is more intensively deployed in the market, the profitability of every firm decreases. Interestingly, in our empirical setting, this negative effect eventually leads to an aggregate negative impact on the profitability of the savings banks.

Broadband and local growth

I find a positive relationship between broadband expansion and local economic growth. This relationship is stronger in industries that rely more on information technology and in areas with lower population densities. Instrumenting for broadband expansion with slope of terrain leans in the direction of a causal relationship, though not definitively. The economic benefits of broadband expansion for local residents appear to be limited. Broadband expansion is associated with population growth as well as employment growth, and both the average wage and the employment rate—the share of working-age adults that is employed—are unaffected by broadband expansion. Furthermore, expanding broadband availability does not change the prevalence of telecommuting or other home-based work. Like other place-based policies, expanding broadband availability could raise property values and the local tax base, but without more direct benefits for residents in the form of higher wages or improved access to jobs. The analysis relies on the uneven diffusion of broadband throughout the United States, allowing comparisons between areas with greater and less growth in broadband availability. I combine broadband data from the Federal Communications Commission, employment data from the National Establishment Time-Series database, and other economic data from the US Census and BLS to examine broadband availability and economic activity in the US between 1999 and 2006.

SU‐E‐T‐384: Dosimetry Studies for Radioactive Gold Nanoparticles

Purpose: This investigation was initiated to determine the absorbed dose and radioactivity distribution of radioactive gold nanoparticles.Methods: Polymer gel dosimeter was prepared using about 12% gelatin (Sigma Aldrich, 300 bloom type A), 9% methacrylic acid(Sigma Aldrich), 10mM THPC (Sigma Aldrich), 18mM hydroquinone (Sigma Aldrich) in deionized water. These dosimeters are used for calibration purpose and meant to estimate the absorbed dose in the medium from the radiation emitted by the radioactive gold nanoparticles. The high energy gamma dose, activity distribution were measured using SPECT imaging and the phantom used was the ball of play‐doh made by Hasbro Toys. A previously constructed acrylic cast of beagle dogˈs head was used in this study to place the phantom. The radioactive gold nanoparticles were synthesized at the University owned nuclear reactor with the high neutron flux of ∼10e14 neutrons/cm2/sec.Results: Carbohydrate suspended radioactive nanoparticles with approximately 200 microCuries were injected in a play doh ball, depicting the prostate gland of beagle dog, approximately 1 inch diameter (8–10ml) in size. The phantom was placed on the SPECT imaging table near the isocenter of the imaging plane. The Gamma camera was peaked for the 411keV photon and equipped with a high energy (Iodine collimator). The phantom was then imaged using SPECT imaging protocol. The activity imaged at various planes and count rates was evenly distributed as predicted Conclusions: The activity distribution as seen in the SPECT imaging indicated active hot and cold spots of radioactive gold nanoparticles. The use of play‐doh determines the activity distribution but uneven diffusion. To compensate for that polymer gel dosimeters, equivalent to the tissue densities may be considered, besides there is also an advantage of estimating the absorbed doses.

On the Position of Bugotu and Gela in the Guadalcanal-Nggelic Subgroup of Oceanic

Guadalcanal-Nggelic (GN) is one of two branches of the Southeast Solomonic subgroup of Oceanic. Citing phonological and lexicostatistical evidence, several scholars have proposed an internal classification of GN in which Bugotu is an isolate, coordinate with a branch consisting of all remaining languages including Gela. This paper will argue that there are stronger grounds for an earlier and contrary hypothesis of mine that Bugotu and Gela form a closed, second-order subgroup of GN, here labeled Nggelic. The existence of longstanding dialect networks in the GN area means that determining the most probable directions and sequence in which particular innovations spread requires considerable interpretive work. The distribution of morphological innovations points to an early divergence between a dialect area ancestral to the Nggelic and North and West Guadalcanal languages, on the one hand, and a dialect area ancestral to the Southeast Guadalcanal languages, on the other, the two areas being separated by the rugged central mountain range. The fact that there are some lexical isoglosses shared by certain Southeast Guadalcanal languages with North and West Guadalcanal languages exclusively of Nggelic can best be explained by supposing that, after Nggelic diverged from North and West Guadalcanal, all the Guadalcanal dialects participated in a network of speech communities within which there was considerable but uneven diffusion of lexical items.

The Shallow and Uneven Diffusion of Capitalism into Everyday Life in Post-Soviet Moscow

A small but rapidly growing body of scholars of contemporary economic development in both Eastern and Central Europe and beyond have begun to question the narrative of impending capitalist hegemony. The aim of this article is to contribute to this emergent stream of thought by first developing a conceptual framework to map the incursion of capitalism and persistence of multiple economic practises in any economy and second, applying this to understanding the everyday economy of post-Soviet Moscow. Conceptualizing economic practises along a spectrum from market to non-market oriented practises, cross-cut by another spectrum from wholly monetized to wholly non-monetized practises, this reveals the shallow and uneven permeation of market practises in post-Soviet Moscow as well as how both work cultures and the nature of individual economic practises vary across Moscow's urban landscape.

Protecting Women Asylum Seekers and Refugees: From International Norms to National Protection?

AbstractLittle attention is paid in most national asylum policies and legislation to the specific position of female asylum seekers, and to gendered aspects of refugee and asylum situations. Further, even in those countries that have adopted asylum legislation to specifically address the question of women asylum seekers and victims of gender specific persecution, problems still remain in the implementation of these policies and in the full recognition of persecutions specific to women. Whilst the issue of protection of women victims of this type of violence have been put on the international agenda, at least to some extent, through directives on the defence of women’s human rights and on the protection of female refugees and asylum seekers, the international norms which have thus been created have been implemented unevenly and unequally in different national contexts. This article seeks to analyse the extent to which national asylum legislation and policies have integrated a concern with the protection of women victims of gender specific forms of persecution, and how effective this implementation has been. The article will engage critically with existing accounts of global norm creation to examine the uneven diffusion and implementation of norms on the protection of female refugees, pointing to the importance of discursive opportunity structures open to actors in mobilising around these issues at local and national levels. It will also argue that even where policies and legislation dealing specifically with women refugees and asylum seekers do exist, they may not actually address some of the important insecurities facing these women because of an approach that does not fully comprehend and act upon gendered structures and relations of power.

Broadband and Local Growth

I find a positive relationship between broadband expansion and local economic growth. This relationship is stronger in industries that rely more on information technology and in areas with lower population densities. Instrumenting for broadband expansion with slope of terrain leans in the direction of a causal relationship, though not definitively. The economic benefits of broadband expansion for local residents appear to be limited. Broadband expansion is associated with population growth as well as employment growth, and both the average wage and the employment rate – the share of working-age adults that is employed – are unaffected by broadband expansion. Furthermore, expanding broadband availability does not change the prevalence of telecommuting or other home-based work. Like other place-based policies, expanding broadband availability could raise property values and the local tax base, but without more direct benefits for residents in the form of higher wages or improved access to jobs.The analysis relies on the uneven diffusion of broadband throughout the United States, allowing comparisons between areas with greater and less growth in broadband availability. I combine broadband data from the Federal Communications Commission, employment data from the National Establishment Time-Series database, and other economic data from the U.S. Census and BLS to examine broadband availability and economic activity in the U.S. between 1999 and 2006.

World society, family planning programs and the health of children

PurposeDrawing on world society and policy analysis literatures, the purpose of this paper is to examine the uneven diffusion of family planning programs in the developing world and the subsequent consequences for child health. The study begins by assessing the effect of world society ties on countries' commitment to and capacity for family planning programs. It then examines the impact such programs have on child health inputs and survival.Design/methodology/approachThis paper uses a cross‐national, quantitative study design on a sample of less developed countries.FindingsCountries' world society embeddedness is a robust predictor of their institutional commitment to and capacity for family planning programs. Such program efforts are also shown to have a significant impact on child survival rates, mediated by reduced fertility and higher rates of childhood immunization.Research limitations/implicationsFuture research should further explore the way in which such programs contribute to and/or serve as a foundation for health infrastructure in developing countries.Practical implicationsThis study points to the child health benefits associated with building capacity in family planning programs. Practitioners should take care to appropriately adapt global policy models to local needs and circumstances while allowing local control.Originality/valueThis paper contributes to a growing body of literature on the role of world society (international nongovernmental organization) networks in spreading development policies and programs in the developing world. Going one step further, it assesses the actual impact of one such policy program on children's health.

Uneven Economic Growth and the World Economy’s North-South Stratification

The liberal formula for peace and prosperity in the 21st century involves substantial convergence in economic growth rates between the affluent North and the poor South, facilitating a decrease in the global North–South gap. This diminished developmental gap should lead to reduced conflict within the South and between the North and South. The problem is that long-term world economic growth is stimulated in part by intermittent upsurges in radical technology generated principally in the system's lead economy. These growth impulses diffuse outwards from the center of the North unevenly. We hypothesize that Northern economies are the primary beneficiaries of these periodic extensions of the technological frontier and that much less trickles down to the South. We test this question of uneven diffusion with time series data dating back to 1870 on systemic leadership growth, Northern economic growth, and Southern economic growth. We find that technological gains in the North have been more likely to expand the North–South gap than to close it. To the extent that the South and Southern turmoil are a function of uneven growth and stratification, neither is apt to disappear anytime soon.

The North-South Divide and International Studies: A Symposium1

This symposium on the North–South Divide encompasses a sample of papers delivered at the 2006 annual meeting of the International Studies Association in San Diego, California. Our intention is not to exhaustively catalogue all aspects of this structured dimension in international relations. Nor do we seek to resolve the issues at risk. Rather, our thesis is that North–South issues have already become prominent and they are likely to become even more prominent in the future. We would all do well to recognize them more explicitly and to focus more analytical attention on North–South questions as they move toward the center of the world stage. Economic history is not a destiny but it has been a powerful factor in shaping the nature of international relations over the past several centuries. Precisely where one should break into a very long story of economic development is debatable, but many analysts would be comfortable in beginning with the British Industrial Revolution in the late eighteenth century. Innovations in producing iron and textiles led to the creation of a technological edge for the innovating pioneers and were followed by subsequent waves of further radical innovations (steam, electricity, gasoline engines, computers) in production and transportation and the uneven diffusion of the capability to emulate, absorb, and improve upon the industrial armature of modern economic growth. The consequent distribution of technological edge and emulation created an increasingly unequal world in which the economies that could work with the new technologies became highly affluent and those that could not did not nor were they able to prosper anywhere near the same extent. Highly structured inequality also created greater incentives for late developers to try to catch up with the pioneers as quickly as possible. In turn, these incentives contributed importantly to two world wars and a Cold War …

Radiative Properties of Patterned Wafers With Nanoscale Linewidth

Abstract Temperature nonuniformity is a critical problem in rapid thermal processing (RTP) of wafers because it leads to uneven diffusion of implanted dopants and introduces thermal stress. One cause of the problem is nonuniform absorption of thermal radiation, especially in patterned wafers, where the optical properties vary across the wafer surface. Recent developments in RTP have led to the use of millisecond-duration heating cycle, which is too short for thermal diffusion to even out the temperature distribution. The feature size is already below 100nm and is smaller than the wavelength (200-1000nm) of the flash-lamp radiation. Little is known to the spectral distribution of the absorbed energy for different patterning structures. This paper presents a parametric study of the radiative properties of patterned wafers with the smallest feature dimension down to 30nm, considering the effects of temperature, wavelength, polarization, and angle of incidence. The rigorous coupled wave analysis is employed to obtain numerical solutions of the Maxwell equations and to assess the applicability of the method of homogenization based on effective medium formulations.

Das Wasser, die Moderne und der Niedergang der bakteriologischen Stadt

If we trace the flow of water through the modern metropolis we uncover not only the material networks that bind together urban space but also those institutional and ideological structures that enable a modern city to function effectively. The article explores how the connections between water engineering, bacteriology and the development of new forms of municipal governance in the modern era contributed to the production of a different kind of urban landscape in the service of a far wider public than the uneven diffusion of water technologies in the past. The essay argues that the last thirty years have seen another fundamental alteration in the relationship between water and urban space marked by a fading of the technocratic model of municipal management and the emergence of a diffuse, fragmentary and polarized urban technological scenery.

Catching a Wave: The Adoption of Voice and High-Commitment Workplace Practices in Britain, 1984-1998

In this paper we treat workplace voice and systems of high-commitment human resource management (HCHRM) as technological innovations in order to account for the uneven diffusion patterns observed across establishments. Using British data, the paper finds that variables highlighted in the technological diffusion literature are significant predictors of voice and HRM adoption decisions. Workplace size, size of multi-establishment network, ownership type, set-up date and network affects all play a significant role in high-commitment HRM adoption. We also find that union presence, per se, is not an inhibitor to the adoption of high commitment HRM practices.

What Explains the Uneven Take-Up of ISO 14001 at the Global Level? A Panel-Data Analysis

Since its release in the mid-1990s, close to 37 000 facilities have been certified to ISO 14001, the international voluntary standard for environmental management systems. Yet, despite claims that the standard can be readily adapted to very different corporate and geographic settings, its take-up has been highly geographically variable. This paper contributes to a growing body of work concerned with explaining the uneven diffusion of ISO 14001 at the global level. Drawing from the existing theoretical and empirical literature we develop a series of hypotheses about how various economic, market, and regulatory factors influence the national count of ISO 14001 certifications. These hypotheses are then tested using econometric estimation techniques with data for a panel of 142 developed and developing countries. We find that per capita ISO 14001 counts are positively correlated with income per capita, stock of foreign direct investment, exports of goods and services to Europe and Japan, and pressure from civil society. Conversely, productivity and levels of state intervention are negatively correlated. The paper finishes by offering a number of recommendations to policymakers concerned with accelerating the diffusion of voluntary environmental standards.