bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification of forces shaping the commensal Escherichia coli genetic structure by comparing animal and human isolates
Authors: Escobar‐Páramo Patricia , Le Menac’h Arnaud , Le Gall Tony , Amorin Christine , Gouriou Stéphanie , Picard Bertrand , Skurnik David , Denamur Erick 
Published: July 2006

SummaryTo identify forces shaping the Escherichia coli intraspecies ecological structure, we have characterized in terms of phylogenetic group (A, B1, D and B2) belonging, presence/absence of extraintestinal virulence genes (pap, sfa, hly and aer) and intra‐host phylotype diversity a collection of 1898 commensal isolates originating from 387 animals (birds and mammals) sampled in the 1980s and the 2000s. These data have been compared with 760 human commensal isolates, sampled from 152 healthy subjects in the 2000s, and analysed with the same approach. The prevalence of the E. coli phylogenetic groups in birds, non‐human mammals and humans is clearly different with a predominance of D/B1, A/B1 and A/B2 strains respectively. A major force shaping the ecological structure is the environment with a strong effect of domestication and the year of sampling followed by the climate. Host characteristics, as the diet and body mass, also influence the ecological structure. Human microbiota are characterized by a higher prevalence of virulence genes and a lower intra‐host diversity than the non‐human mammal ones. This work identifies for the first time a group of strains specific to the animals, the B1 phylogenetic group strains exhibiting the hly gene. In conclusion, a complex network of factors seems to shape the ecological structure of commensal E. coli, with anthropogenic factors playing a major role and perturbing natural niche equilibrium.
Vertical distribution of nitrifying populations in bacterial biofilms from a full‐scale nitrifying trickling filter
Authors: Lydmark Pär , Lind Magnus , Sörensson Fred , Hermansson Malte 
Published: July 2006

SummaryCryosectioned biofilm from three depths (0.5, 3.0 and 6.0 m) in a full‐scale nitrifying trickling filter (NTF) were studied using fluorescence in situ hybridization (FISH). A large number of sections were used to determine how the biofilm thickness, structure and community composition varied with depth along the ammonium concentration gradient in the NTF, and how the ammonia‐oxidizing bacteria (AOB) and nitrite‐oxidizing bacteria (NOB) were distributed vertically within the biofilm. Both the biofilm thickness and relative biomass content of the biofilm decreased with depth, along with structural differences such as void size and surface roughness. Four AOB populations were found, with two Nitrosomonas oligotropha populations dominating at all depths. A smaller population of Nitrosomonas europaea was present only at 0.5 m, while a population of Nitrosomonas communis increased with depth. The two N. oligotropha populations showed different vertical distribution patterns within the biofilm, indicating different ecophysiologies even though they belong to the same AOB lineage. All NOB were identified as Nitrospira sp., and were generally more associated with the biofilm base than the surface‐associated dominating AOB population. Additionally, a small population of anaerobic ammonia‐oxidizers was found at 6.0 m, even though the biofilm was well aerated.
The Spatial Urban Hierarchy in Turkey: Its Structure and Some of Its Determinants
Authors: MUTLU SERVET 
Published: July 2006

ABSTRACTThis paper gives a detailed description of the Turkish spatial hierarchy, tests certain aspects of the central place theory, and identifies the principles by which the hierarchy is organized.From the results of a country‐wide survey, a seven‐level hierarchy is identified. The system does not conform to any of the pure theoretical networks. The number of lower order satellites per center and the sizes and populations of the nested tributary areas vary both vertically and horizontally‐that is, both across and within levels in the hierarchy. The spreads around the means of center sizes in each level and the populations and sizes of tributary areas are too great to permit unequivocal statements about typical magnitudes of the variates. The trade areas of centers consist mostly of monopolistic zones of influence showing the effects of a centralized administrative system especially at the second and third levels of the hierarchy.Regression analysis reveals that different factors operate at different levels and with varying intensities in ordering the structure of the system with no one factor being predominant. Income per capita, the density of the road network, the nature of the terrain, the degree of spatial mobility, the structure of economic activity in rural areas, and the distribution of labor force by type of activity emerge as ordering the frequency of centers and the sizes of their nested tributary areas. The regression analysis also reveals that the hypothesized positive relationship between center size and complementary area population, although holding at the second and third order levels, breaks down at the first order, suggesting that first order centers are quasi‐central places, with primary activities as the dominant mode of their economies. These centers appear to serve themselves principally, and only secondarily their hinterlands. Possibly this results from a lack of connectivity with the settlements in their tributary areas.
Changing Patterns of Migration and Regional Economic Growth in the U.S.: A Demographic Perspective
Authors: GREENWOOD MICHAEL J. 
Published: July 2006

ABSTRACTDuring the 1970s and early 1980s, the South and West Census regions accounted for over 90 percent of incremental national population, which was easily the highest percentage accounted for by these regions in the nation's history. This paper stresses the importance of powerful demographic forces that contributed to the regional shift, but it does not ignore important economic factors. A major theme of the paper is that because the baby boom has now largely matured out of the most mobile age classes, population and employment growth differentials that strongly favored the South and West will moderate in the future.
Manufacturing Decline and Technology Lags in Nonmetropolitan Illinois
Authors: ESPARZA ADRIAN 
Published: July 2006

ABSTRACTNumerous studies have focused on national and regional manufacturing decline in the U.S., but far less attention has been placed on decline in substate areas. This oversight is troublesome because manufacturing decline in substate areas, particularly in the Midwest, has been severe and prolonged. This paper, therefore, examines the causes of manufacturing decline at the substate level. Specifically, I evaluate whether the impact of factors influencing decline varies according to the size and location of medium‐ and small‐sized cities in Illinois. Survey data and loglinear modeling methods are used for the empirical analysis. The results indicate that the impact of technology lags in substate areas varies significantly by the size of cities. The effects of technology, the regional shift of manufacturing, and federal trade policies are influenced by the relative location of cities.
The Strange Case of the Missing West Virginia Labor Force
Authors: DORSEY STUART 
Published: July 2006

ABSTRACTThe rate of labor force participation in West Virginia is far below all other states. This study finds that little of the participation rate gap can be attributed to traditional economic or institutional factors. For example, the high long‐term unemployment rate in West Virginia accounts for less than 10 percent of the adult male participation gap. Most of the difference is associated with a large Appalachian population, and a high rate of federal disability benefits receipt. The latter, which we argue reflects tastes for nonmarket activities, also is a major factor in low participation rates of West Virginia adult females and teenagers. Unemployment does explain a significant portion of low participation rates for these groups. However, we estimate that a decline in the state's long‐term unemployment rate to the nation's average would raise its aggregate participation rate by 3.9 percentage points, or just 28 percent of the total gap. It appears that nonparticipating West Virginians are not just “discouraged workers,” and that economic development policies should explore ways to increase aggregate labor supply, as well as labor demand.
The Recent Divergence of Regional Per Capita Incomes: Some Evidence from Australia
Authors: MAXWELL PHILIP , HITE JAMES C. 
Published: July 2006

ABSTRACTAre recent trends toward state per capita income divergence observed in the United States also evident elsewhere in the world? This paper focuses upon interregional income divergence in Australia where a pattern very similar to that seen in the United States is discovered. Australian agricultural regions show downward divergence from the national mean per capita income and capital city regions show upward divergence.
Air Passenger Transportation and Growth in the U.S. Urban System, 1950–1987
Authors: GOETZ ANDREW R. 
Published: July 2006

The relationship between transportation and urbanization at the national scale is revisited by focusing upon the role that air passenger transportation has played in the post‐war evolution of the U.S. urban system. Theory suggests that major transportation innovations have exhibited profound and prolonged interdependencies with patterns of growth in national or regional urban systems. As the most recent major intercity transportation innovation, it should be expected that utilization of air transportation should bear some relationship to patterns of growth in urban places.This paper documents this relationship by using FAA and U.S. Census data to correlate volumes of air passenger flows per capita with changes in population and employment for the 50 largest U.S. metropolitan areas. The expectation that higher volumes of air passenger flow per capita exhibit a positive correlation with both previous and subsequent growth is confirmed by the analysis. More detailed examination of both high and low air passenger index cities suggests functional and regional consistencies with the central hypothesis. The implications of these results for air transportation and airport planning include at least some justification for increased attention to provision of air service and adequate airport infrastructure as well as reiteration of the importance of air transportation in economic development.
Regional Change in Middle Class Earnings and Standards of Living
Authors: LEIGH NANCEY GREEN 
Published: July 2006

ABSTRACTThis research examines key components of the broad national debate over the decline of the middle economic class of the United States at the regional level. Full‐time and part‐time workers’distributions of earnings among the low‐, middle‐ and upper‐earner groups are examined for the four major Census regions from 1967 to 1987. The premise is that the postwar boom era was a period in which the earnings of one full‐time worker could purchase a middle standard of living (using home ownership as a proxy) for a household. Thus, change in the purchasing power of full‐time earnings for home ownership is tracked between 1967 and 1987 at the regional level. In addition, regional changes in levels of fringe‐benefit recipiency are examined.Full‐time workers have seen a dramatic upwards shift in their earnings disiributions in all regions, accompanied by substantial erosion in their purchasing power. Earnings distributions across regions have converged, but the costs of home ownership have diverged. As a result, certain regions offer locational advantages for consuming the middle standard of living. Arising from these findings, this paper concludes with a set of questions for policymakers.
The Housing, Geography, and Mobility of Latin American Urban, Poor: The Prevailing Model and the Case of Quito, Ecuador
Authors: KLAK THOMAS , HOLTZCLAW MICHAEL 
Published: July 2006

ABSTRACTJohn Turner's benchmark model of the Latin American city depicts relationships between urban growth and the intra‐urban mobility, shelter, economic status and location of its low‐income migrants. This conceptual model, described below, requires additional empirical assessment, quantitative specification, and updating to encompass the deep regional recession since 1980. Evidence from a survey of low‐income migrants in Quito in 1989 supports portions of the model. However, Quito does not support the model's other predictions about the geography of shanties, houses, and migrants based on length of residence and employment patterns. The poor scramble for work and shelter wherever they may be found. Quito's enforcement of policies against land invasions confines a relatively large portion of the poor to rented rooms. We conclude that the model underconceptualizes and overstates relationships between a Latin American city's phase of urbanization and the length of residence, location, shelter, and work of its low‐income migrants. Rather than abandoning the model, however, we recommend that research use it as a point of departure for investigating the additional contributions of local development and policy.
Industrial Innovation among Small and Medium‐Sized Firms in a Declining Region
Authors: MACPHERSON ALAN D. 
Published: July 2006

ABSTRACT:This paper explores the impact of new technology adoption upon the market performance of small industrial firms. Survey data from a six‐sector sample of Western New York manufacturers are presented. The results suggest a positive relationship between new technology adoption and growth of exports, value‐added, and total sales. A central finding of the study is that flexible manufacturing systems (FMS) confer different types of technical and commercial advantages across sectors. Two broad groups of process innovators are identified: (1) those that adopt new technology primarily to cut unit costs; and (2) those that aspire toward greater production flexibility. The paper concludes with a brief discussion of the regional development implications that flow from the empirical results.
Cities and the ‘War on Terror’
Authors: GRAHAM STEPHEN 
Published: July 2006

AbstractProgrammes of organized, political violence have always been legitimized and sustained through complex imaginative geographies. These tend to be characterized by stark binaries of place attachment. This article argues that the discursive construction of the Bush administration’s ‘war on terror’ since September 11th 2001 has been deeply marked by attempts to rework imaginative geographies separating the urban places of the US ‘homeland’ and those Arab cities purported to be the sources of ‘terrorist’ threats against US national interests. On the one hand, imaginative geographies of US cities have been reworked to construct them as ‘homeland’ spaces which must be re‐engineered to address supposed imperatives of ‘national security’. On the other, Arab cities have been imaginatively constructed as little more than ‘terrorist nest’ targets to soak up US military firepower. Meanwhile, the article shows how both ‘homeland’ and ‘target’ cities are increasingly being treated together as a single, integrated ‘battlespace’ within post 9/11 US military doctrine and techno‐science. The article concludes with a discussion of the central roles of urban imaginative geographies, overlaid by transnational architectures of US military technology, in sustaining the colonial territorial configurations of a hyper‐militarized US Empire.
Regulation of chronological aging in Schizosaccharomyces pombe by the protein kinases Pka1 and Sck2
Authors: Roux Antoine E. , Quissac Aurélie , Chartrand Pascal , Ferbeyre Gerardo , Rokeach Luis A. 
Published: July 2006

SummaryBudding yeast shows a progressive decline in viability after entering stationary phase, a phenomenon known as chronological aging. We show here that the fission yeast Schizosaccharomyces pombe also undergoes chronological aging and that the process is regulated by genes controlling two related nutrient signalling pathways. The first pathway includes the serine/threonine cAMP‐activated protein kinase Pka1 and the second pathway comprises the serine/threonine kinase Sck2, a homologue of Saccharomyces cerevisiae SCH9. A double mutant for pka1 and sck2 displayed an additive effect on prolonging the fission yeast lifespan, suggesting that these genes regulate related but independent pathways. These long‐lived mutants also accumulated less reactive oxygen species and had a delayed initiation of apoptosis compared with wild‐type cells. We also found that strains carrying pka1 deletion but not those with sck2 deletion gained resistance to oxidative stress due to exposure to H2O2 or menadione. On the other hand, the additional increase in lifespan shown by the Δpka1Δsck2 double‐mutant strain correlated with an increased resistance to both oxidative stress and heat shock. These results underscore the importance of nutrient signalling pathways and reactive oxygen species on organismal lifespan and establish S. pombe as a new model organism to study the molecular mechanisms underlying aging.
Refractory Status Epilepticus: Is EEG Burst Suppression an Appropriate Treatment Target during Drug-Induced Coma? What is the Holy Grail?
Authors: Bergey Gregory K. 
Published: July 2006

Refractory Status Epilepticus: Effect of Treatment Aggressiveness on Prognosis Rossetti AO, Logroscino G, Bromfield EB Arch Neurol 2005;62(11):1698–1702 Background Administration of antiepileptic drugs for coma induction in refractory status epilepticus (RSE) has not been widely studied. Moreover, the effect on outcome of electroencephalographic (EEG) burst suppression remains unclear. Objective To investigate whether various coma-inducing options are associated with different prognoses after RSE. Design Retrospectively assessed case series. Setting Two tertiary referral hospitals in Boston, Massachusetts. Patients Among 127 consecutive episodes (107 patients) of status epilepticus, we identified episodes that were refractory to first-line and second-line antiepileptic drugs, needing induced coma with barbiturates, propofol, or midazolam for clinical management. Main Outcome Measures Short-term mortality and prevalence of return to functional baseline after the acute episode of status epilepticus were analyzed in relation to demographic and clinical variables and to treatment option (antiepileptic agents and EEG burst suppression). Results Forty-nine episodes of RSE (47 patients) were found, occurring more frequently in incident than in recurrent episodes of status epilepticus ( p = .06). Mortality was 23% for patients with RSE and 8% for those without RSE ( p = .05). Return to baseline occurred more often in the non-RSE group ( p = .04). In 20 (61%) of 33 monitored episodes, EEG burst suppression was achieved. Demographic data, clinical variables, and outcome did not differ significantly with the various coma-inducing agents or between episodes with and without EEG burst suppression. Conclusions Refractory status epilepticus is more prevalent in incident than in recurrent status epilepticus and is associated with higher mortality; clinical status is less likely to return to baseline than with non-RSE. Outcome was independent of the specific coma-inducing agents used and the extent of EEG burst suppression, suggesting that the underlying cause represents its main determinant.
Inhibitory GABA Current Rundown in Epileptic Brain: Use-Dependent and Pathology-Specific Mechanisms
Authors: Janigro Damir 
Published: July 2006

Rundown of GABA Type A Receptors Is a Dysfunction Associated with Human Drug-Resistant Mesial Temporal Lobe Epilepsy Ragozzino D, Palma E, Di Angelantonio S, Amici M, Mascia A, Arcella A, Giangaspero F, Cantore G, Di Gennaro G, Manfredi M, Esposito V, Quarato PP, Miledi R, Eusebi F Proc Natl Acad Sci U S A 2005;102(42):15219–15223 Pharmacotherapeutic strategies have been difficult to develop for several forms of temporal lobe epilepsy, which are consequently treated by surgical resection. To examine this problem, we have studied the properties of transmitter receptors of tissues removed during surgical treatment. We find that when cell membranes, isolated from the temporal neocortex of patients afflicted with drug-resistant mesial temporal lobe epilepsy (TLE), are injected into frog oocytes they acquire GABA type A receptors (GABAA-receptors) that display a marked rundown during repetitive applications of GABA. In contrast, GABAA-receptor function is stable in oocytes injected with cell membranes isolated from the temporal lobe of TLE patients afflicted with neoplastic, dysgenetic, traumatic, or ischemic temporal lesions (lesional TLE, LTLE). Use-dependent GABAA-receptor rundown is also found in the pyramidal neurons of TLE neocortical slices and is antagonized by BDNF. Pyramidal neurons in cortical slices of a traumatic LTLE patient did not show GABAA-receptor rundown. However, the apparent affinity of GABAA-receptor in oocytes microtransplanted with membranes from all of the epileptic patients studied was smaller than the affinity of receptors transplanted from the nonepileptic brain. We conclude that the use-dependent rundown of neocortical GABAA-receptor represents a TLE-specific dysfunction, whereas the reduced affinity may be a general feature of brains of both TLE and LTLE patients, and we speculate that our findings may help to develop new treatments for TLE and LTLE.
Age and Gender Difference in ST Height at Rest and after Double Autonomic Blockade in Normal Adults
Authors: Endres Susanne , Mayuga Kenneth A. , De Cristofaro Alessandro , Taneja Taresh , Goldberger Jeffrey J. , Kadish Alan H. 
Published: July 2006

Background: ST elevation is commonly seen in young, healthy men. The exact mechanisms that cause ST height to be greater in young men are not yet completely understood. The purpose of the present study was to determine whether autonomic tone is responsible for age and gender differences in ST height. Methods: Gender and age differences in ST height were studied at rest and after double autonomic blockade (DAB) with atropine and propranolol. Fifty healthy men and women were included (16 men, 14 women, age 23–32 years; 9 men, 11 women, age 65–79 years). Twelve‐lead ECGs were registered at rest and after DAB. Leads II and V1–V4 were chosen for analysis. ST height (in mm) was measured manually at the J‐point, and 40 ms and 80 ms after the J‐point. Values were corrected for QRS amplitude. Results: Gender and age differences in ST height were seen in both rest and DAB data. Men had greater ST height compared to women at J‐point, 40 and 80 ms after the J‐point (P ≤ 0.0001), and younger subjects had greater ST height than older subjects at J‐point (P = 0.0140), 40 and 80 ms after the J‐point (P ≤ 0.0001). DAB did not change ST height at J‐point or at 40 ms, but increased ST height at 80 ms. Women had less of an increase in ST height following DAB than men did. Conclusions: ST elevation in the absence of structural or electrical heart disease is mainly seen in young men. Age and gender difference persist after DAB and thus are not due to differences in autonomic tone.