bluuebunny/crossref_metadata_2025 huggingface dataset:
Nitrogen‐regulated effects of free‐air CO2 enrichment on methane emissions from paddy rice fields
Authors: ZHENG XUNHUA , ZHOU ZAIXING , WANG YUESI , ZHU JIANGUO , WANG YULONG , YUE JIN , SHI YI , KOBAYASHI KAZUHIKO , INUBUSHI KAZUYUKI , HUANG YAO , HAN SHENGHUI , XU ZHONGJUN , XIE BAOHUA , BUTTERBACH‐BAHL KLAUS , YANG LIANXIN
Published: July 2006

Using the free‐air CO2 enrichment (FACE) techniques, we carried out a 3‐year mono‐factorial experiment in temperate paddy rice fields of Japan (1998–2000) and a 3‐year multifactorial experiment in subtropical paddy rice fields in the Yangtze River delta in China (2001–2003), to investigate the methane (CH4) emissions in response to an elevated atmospheric CO2 concentration (200±40 mmol mol−1 higher than that in the ambient atmosphere). No significant effect of the elevated CO2 upon seasonal accumulative CH4 emissions was observed in the first rice season, but significant stimulatory effects (CH4 increase ranging from 38% to 188%, with a mean of 88%) were observed in the second and third rice seasons in the fields with or without organic matter addition. The stimulatory effects of the elevated CO2 upon seasonal accumulative CH4 emissions were negatively correlated with the addition rates of decomposable organic carbon (P<0.05), but positively with the rates of nitrogen fertilizers applied in either the current rice season (P<0.05) or the whole year (P<0.01). Six mechanisms were proposed to explain collectively the observations. Soil nitrogen availability was identified as an important regulator. The effect of soil nitrogen availability on the observed relation between elevated CO2 and CH4 emission can be explained by (a) modifying the C/N ratio of the plant residues formed in the previous growing season(s); (b) changing the inhibitory effect of high C/N ratio on plant residue decomposition in the current growing season; and (c) altering the stimulatory effects of CO2 enrichment upon plant growth, as well as nitrogen uptake in the current growing season. This study implies that the concurrent enrichment of reactive nitrogen in the global ecosystems may accelerate the increase of atmospheric methane by initiating a stimulatory effect of the ongoing dramatic atmospheric CO2 enrichment upon methane emissions from nitrogen‐poor paddy rice ecosystems and further amplifying the existing stimulatory effect in nitrogen‐rich paddy rice ecosystems.
Global warming and excess nitrogen may induce butterfly decline by microclimatic cooling
Authors: WALLISDEVRIES MICHIEL F. , VAN SWAAY CHRIS A.M.
Published: July 2006

Global warming may explain the current poleward shift of species distributions. However, paradoxically, climatic warming can lead to microclimatic cooling in spring by advancing plant growth, an effect worsened by excess nitrogen. We suggest that spring‐developing but thermophilous organisms, such as butterflies hibernating as egg or larva, are particularly sensitive to the cooling of microclimates. Using published data on butterfly trends in distribution, we report a comparatively greater decline in egg–larva hibernators in European countries with oceanic climates and high nitrogen deposition, which supports this explanation. Furthermore, trends in abundance from a nationwide butterfly monitoring scheme reveal a 63% decrease over 13 years (1992–2004) for egg–larva hibernators in the Netherlands, contrasting with a nonsignificant trend in adult–pupa hibernators. This evidence supports the hypothesis that these environmental changes pose new threats to spring‐developing, thermophilous species. We underline the threat of climate change to biodiversity, as previously suggested on the basis of mobility, habitat fragmentation and evolutionary adaptation, but we here emphasize a different ecological axis of change in habitat quality.
Effects of Long‐Term Hormone Treatment and of Tibolone on Monoamines and Monoamine Metabolites in the Brains of Ovariectomised, Cynomologous Monkeys
Authors: Gibbs R. B. , Edwards D. , Lazar N. , Nelson D. , Talameh J.
Published: July 2006

The effects of long‐term hormone treatment on monoamines and monoamine metabolites in different regions of the primate brain were examined and compared. Ovariectomised Cynomologous monkeys received daily oral administration of either conjugated equine oestrogens (CEE), CEE + medroxyprogesterone acetate (MPA), or a low or high dose of tibolone, for a period of 2 years. Tissue punches collected from frozen sections through various regions of the forebrain, midbrain, and hindbrain were assayed for levels of dopamine, dihydroxyphenylacetic acid (DOPAC), serotonin, 5‐hydroxyindole acetic acid (5‐HIAA), and norepinephrine by high‐performance liquid chromatography. Few differences between hormone‐treated animals and ovariectomised controls were observed. No statistically significant effects of CEE relative to controls were detected in any of the seven brain regions analysed. Animals treated with CEE + MPA showed significant reductions in 5‐HIAA in the dorsal raphe nucleus, a significant reduction in dopamine in the hypothalamus, and a significant reduction in serotonin (5‐HT) levels in area 8AD of the frontal cortex. Similar to CEE, no significant effects of tibolone relative to controls were detected; however, animals treated with high‐dose tibolone showed a decrease in 5‐HT levels in the frontal cortex that approached significance and was similar to the effect of CEE + MPA. Collectively, the findings suggest that long‐term oral administration of these compounds has relatively few effects on the levels of dopamine, serotonin, and their primary metabolites in the primate brain. This differs from the significant effects on serotonergic and dopaminergic systems detected following parenteral treatment with oestradiol and progesterone, and likely reflects differences between the effects of treating with CEE + MPA versus oestradiol and progesterone on brain monoaminergic systems.
Treatment rates in patients with chronic hepatitis C after liver biopsy
Authors: Narasimhan G. , Sargios T. N. , Kalakuntla R. , Homel P. , Clain D. J. , Theise N. D. , Bodenheimer H. C. , Min A. D.
Published: July 2006

Summary.  Hepatitis C virus (HCV) infection is a major health problem in the United States. Only about 30% of patients infected with HCV are being treated despite the development of increasingly effective therapies. The aims of this study were to determine the rate of treatment for patients with HCV after undergoing liver biopsy, to assess any change in their treatment rates over recent years and to delineate the reasons for nontreatment. We retrospectively reviewed the charts of all HCV patients who had liver biopsies at Beth Israel Medical Center, New York between 1998 and 2002. The data gathered included patient demographics, stage of liver fibrosis, insurance information, treatment history and reasons for nontreatment. There were 433 liver biopsies done for chronic hepatitis C between 1998 and 2002. Of those, 267 (61%) were men. The mean age was 47 years (range, 18–72). Only 159 (37%) patients were treated after liver biopsy. Overall there were no significant differences in the treatment rates from 1999 to 2002. The common reasons for nontreatment included minimal/mild disease (stage 0–1 fibrosis, 38%), lost to follow‐up or noncompliance (31%) and patient refusal (22%). Older patients more frequently had co‐morbid conditions (P = 0.009). Younger age and female gender correlated with minimal disease on biopsy (P = 0.004 and 0.01, respectively). Men were lost to follow‐up more frequently than women (37%vs 22%, P = 0.01). Multivariate analysis showed that age and gender were both independent predictors of minimal disease. Patients having Medicaid with or without Medicare were significantly more likely to be treated than patients with private or commercial insurance or patients with Medicare alone. A minority of HCV infected patients were treated even after having undergone liver biopsy. The proportion of HCV patients being treated after liver biopsy has been relatively stable despite advances in therapeutic success. Liver histology frequently identified patients with mild disease in whom antiviral therapy was deemed not urgent.
Gametocytocidal activity in antimalarial drugs speeds the spread of drug resistance
Authors: Hastings Ian M.
Published: July 2006

Objective  Antimalarial drugs kill the asexual parasites responsible for causing disease and some, notably chloroquine and the artemisinins, also kill the sexual transmission stages known as gametocytes. It is invariably argued by malariologists that gametocytocidal activity is beneficial because it reduces the rate at which resistance evolves by ‘reducing the transmission of resistant parasites’. This seems dubious from a population genetics perspective, where intuition would lead to the opposite conclusion. The objective was to reconcile these differing views.

Methods  The effect of gametocytocidal drug activity was quantified mathematically and calibrated using field data.

Results  It appears to be a robust result that gametocytocidal activity actually promotes the spread of resistance through a population; the underlying reason is that gametocytocidal activity reduces transmission of drug‐sensitive forms to a greater extent than the drug resistant, thereby increasing the spread of the latter. The increased rate of spread of resistance is quantified and appears to be small providing drug coverage is moderate or low.

Conclusions  Citing reduced spread of resistance as a justification for deploying gametocytocidal antimalarials is unjustified; the deliberate use of a gametocytocidal antimalarial at high coverage to reduce transmission may ultimately be counterproductive through its rapid promotion of drug resistance.

Keywords  Plasmodium falciparum

malaria

drug resistance

combination therapy

gametocytocidal
Patterns of species richness for vascular plants in China's nature reserves
Authors: Zhao Shuqing , Fang Jingyun
Published: July 2006

Explaining the heterogeneous distribution of biodiversity across the Earth has long been a challenge to ecologists and biogeographers. Here, we document the patterns of plant species richness for different taxonomic groups in China's nature reserves, and discuss their possible explanations at national and regional scales, using vascular plant richness data coupled with information on climate and topographical variables. We found that water deficit, energy and elevation range (a surrogate of habitat heterogeneity) represent the primary explanations for variation in plant species richness of the nature reserves across China. There are consistent relationships between species richness and climate and habitat heterogeneity for different taxonomic vascular plant groups at the national scale. Habitat heterogeneity is strongly associated with plant richness in all regions, whereas climatic constraints to plant diversity vary regionally. In the regions where energy is abundant or water is scarce, plant richness patterns were determined by water and habitat heterogeneity, whereas in the region with low energy inputs, water interacting with energy, and habitat heterogeneity determined its species richness pattern. Our results also suggest that energy variables alone do not represent the primary predictor of plant richness.
Museum collections, species distributions, and rarefaction
Authors: Solow Andrew R. , Roberts David L.
Published: July 2006

Biological specimens in museums and herbaria are sometimes used to compare the geographical distribution of different species. In doing so, it is necessary to account for differences in the numbers of specimens. We show how rarefaction can be used for this purpose. Rarefaction is a simple mathematical method originally designed to compare species richness in communities that differed in the number of sampled individuals. We present an example involving two Phragmipedium orchid species. In this case, rarefaction suggests that the apparent difference in range can be explained by the difference in the numbers of specimens.
Age and sex as factors of response to RSV infections among those with previous history of wheezing
Authors: Nagayama Yoko , Tsubaki Toshikazu , Sawada Kyoko , Taguchi Kazuko , Nakayama Shigeru , Toba Tsuyoshi
Published: July 2006

Although enhanced immune reaction caused by the respiratory syncytial virus (RSV) in allergen‐sensitized animal model has been reported, RSV illnesses in children already sensitized or having recurrent wheezing episodes have not been completely studied. In addition, the reason for male dominances in RSV infection at young ages was also inconclusive. Therefore, gender analysis in recurrent wheezing children with RSV infection can shed light on asthma pathogenesis. We studied the clinical features and the laboratory data of RSV infections in children who had recurrent wheezing histories. The subjects with RSV infection consisted of 98 boys and 58 girls. The children under 4 yr of age were 123 (78.8%) in number. Children with pneumonia were 78 and those with febrile episode were 119. Children above 1 yr of age were highly sensitized with mite antigen (75/96, 78.1%). The clinical symptoms and signs differed according to their ages. Children in each age group behaved differently in their immune reaction to RSV. Above all, 3‐yr‐old children deteriorated clinically during acute RSV infection, accompanied by transient elevated C‐reactive protein (CRP) and suppressed blood eosinophil counts. Clinical features differed in several points between boys and girls. In general, the white blood cell count and the CRP levels were higher in girls in every age group. Blood eosinophil counts at the acute illness were significantly higher in boys than girls aged 2 and 3< yr. Age and gender comparison in already sensitized children might suggest a clue to asthma pathogenesis.
Atopy patch testing in children with asthma and rhinitis symptoms allergic to house dust mite
Authors: Guler N. , Kirerleri E. , Tamay Z. , Ones U.
Published: July 2006

The atopy patch test (APT) is generally used to assess immunoglobulin E (IgE) mediated sensitization to allergens in patients with atopic dermatitis, but its diagnostic role in children with respiratory allergy is still controversial. The aim of the study was to evaluate APT with house dust mite (HDM) in children with asthma and rhinitis symptoms allergic to HDM and its relevance to skin prick test (SPT) diameters and specific IgE levels. The study population consisted of 33 children, aged 8–16 yr (median: 12 yr) with asthma and 30 children with allergic rhinitis in the same age range (median: 11 yr). All patients had positive SPT results and high serum specific IgE levels for Dermatophagoides pteronyssinus APT was performed on back skin of all patients with 200 index of reactivity (IR)/ml of D. pteronyssinus allergen extracts in petrolatum (Stallerpatch) and evaluated at 72 h. Of 63 patients, 16 (25%) showed a positive patch test result. APT with HDM showed 30% (10/33) positivity among the patients with asthma and 20% (6/30) positivity among the patients with allergic rhinitis. APT presented no significant correlation with age, SPT diameter, serum total and specific IgE levels for D. pteronyssinus, nasal provocation test or pulmonary function test results. Patch testing with HDM may partly identify mite sensitive children with respiratory allergy. Positive APT results may imply that delayed hypersensitivity reactions play a role in children with asthma and rhinitis allergic to HDM.
Prevalence of sensitization reported and objectively assessed food hypersensitivity amongst six‐year‐old children: A population‐based study
Authors: Venter Carina , Pereira Brett , Grundy Jane , Clayton C. B. , Arshad S. H. , Dean Taraneh
Published: July 2006

There is a paucity of information on food hypersensitivity (FHS) in young children and there are even fewer population‐based studies in this area. The aim of the study was to determine the prevalence of parentally reported FHS, and objectively diagnosed FHS amongst six‐year‐old children and to establish the rates of sensitization to key allergens. This population‐based cohort study recruited 798 6‐year‐olds resident on the Isle of Wight (UK). Sensitization rates, reported rates of FHS and objectively assessed FHS was established using food challenges. A total of 94 (11.8%) 6 yr olds reported a problem with a food or food ingredient. The rate of sensitization to the pre‐defined panel of food allergens was 25/700 (3.6%). Based on open food challenge and/or suggestive history and skin tests, the prevalence of FHS was 2.5% (95% CI 1.5–3.8). Based on double‐blind challenges, a clinical diagnosis or suggestive history and positive skin tests, the prevalence was 1.6% (95% CI 0.9–2.7). The rates of perception of FHS are higher than the prevalence of sensitization to main food allergens and the prevalence of FHS based on food challenges. Milk, peanut and wheat were the key food allergens amongst those with positive challenges.
Bitou Bush control (after fire) in Bundjalung National Park on the New South Wales North Coast
Authors: Thomas Jeff , Hofmeyer Damien , Benwell Andrew S.
Published: July 2006

Bitou Bush has already invaded extensive coastal dunes in subtropical and temperate eastern Australia. Can it be treated at a large enough scale to make a difference? Results to date of a targeted aerial spraying program (applied after wildfire at Bundjalung National Park) are showing strong recovery of high conservation value dunal vegetation along 35 km of the northern New South Wales coastline.
Is revegetation in the Sheep Pen Creek area, Victoria, improving Grey‐crowned Babbler habitat?
Authors: Robinson Doug
Published: July 2006

A substantial increase in numbers of the endangered Grey‐crowned Babbler has occurred in one agricultural area where vegetation has been increased by natural regeneration or planting – but not in areas where there has been little increase in habitat area. This positive response to the provision of new habitat at the local scale gives cause for optimism for the future conservation of some of our woodland birds.
Head and neck blocks in children: an anatomical and procedural review
Authors: SURESH SANTHANAM , VORONOV POLINA
Published: July 2006

Children undergo a variety of neurosurgical, otorhinolaryngology and plastic surgery procedures to the head and neck. Although opioids are utilized for pain control, they are associated with adverse side effects including postoperative nausea and vomiting, respiratory depression, somnolence and itching. The utilization of peripheral nerve blocks provides analgesia while reducing the need for opioids. This review will provide a summary of a variety of commonly used head and neck nerve blocks in children with a brief anatomical and technical summary.
Ultrasound‐guided umbilical nerve block in children: a brief description of a new approach
Authors: DE JOSE MARIA BELEN , GÖTZENS VICTOR , MABROK MAGED
Published: July 2006

Background : The most popular peripheral nerve blocks used in umbilical hernia repair are rectus sheath block and paraumbilical block. However, multiple anatomic variations have been described and some complications may occur. Ultrasonographic guidance of peripheral nerve blocks has reduced the number of complications and improved the quality of blocks. This case series describes a new ultrasound‐guided puncture technique of the 10th intercostal nerve in pediatric umbilical surgery.

Methods : Ten children (age range: 2–5 years) scheduled for umbilical hernia repair were included. Following the induction of general anesthesia, the ultrasonographic anatomy of the umbilical region was studied with a 10‐MHz linear probe. An ultrasound‐guided peripheral block of the 10th intercostal nerve in the lateral edge of both rectus abdominis muscles (RMs) was performed (total of 20 punctures). Surgical conditions, intraoperative hemodynamic parameters, and postoperative analgesia by means of the modified CHEOPS scale were evaluated.

Results : Umbilical anatomy was clearly identified by ultrasound in all cases. The epigastric vessels were identified – above the umbilicus – within the depth of the muscular mass of the RM. The spread of local anesthetic was ultrasound‐controlled in all cases. However, the intercostal nerve could not be visualized. All blocks were effective during the surgery. Postoperative analgesia was only required in two children in the second postoperative hour. There were no complications.

Conclusions : Ultrasound guidance enables performance of an effective umbilical block in the lateral edge of RM. Further studies should be carried on to visualize the intercostal nerve and to compare this technique with the classical ones.
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

To 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

Cryosectioned 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

This 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

During 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

Numerous 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

The 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

Are 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.
Income Inequality Across Regions Over Time
Authors: NISSAN EDWARD , CARTER GEORGE
Published: July 2006

ABSTRACT This paper provides a profile of regional income inequality using a distributional criterion whereby a state's share of total income equals its share of total population. The results for 1929 to 1990 show that inequality persisted among regions with a substantial declining trend up to 1979 and a slight rise thereafter. On the other hand, equality among states within their regions is found to have been the condition since 1929.
Growth Linkages and Urban Development in Niger
Authors: DOAN PETER L. , LEWIS BLANE D.
Published: July 2006

ABSTRACT. It is increasingly recognized that the assumption that the supply of tradable output is perfectly elastic, which underlies many regional economic models (esp. economic base models), does not hold in many developing countries. When the supply of tradable output (primarily agricultural products) and, in many cases, non‐tradable output is inelastic, the resulting income multipliers will be substantially reduced. Recent calls for the promotion of market towns and smaller urban centers have not fully considered the impact of supply in elasticities on the capacity of such measures to stimulate broad‐based development. This study uses data collected from firms in several market‐town systems in Niger to examine the probable consequences. The paper argues that such policies are unlikely to be effective in countries like Niger where the vulnerability of the rural economy has severely limited the elasticity of the supply response, especially for agriculture and nonfarm production by small‐scale producers.
Regional Change in Middle Class Earnings and Standards of Living
Authors: LEIGH NANCEY GREEN
Published: July 2006

This 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

John 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

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.
Location Patterns of High Growth Industries in Rural Counties
Authors: WOJAN TIMOTHY R. , PULVER GLEN C.
Published: July 2006

ABSTRACT The basic premise of this article is that the historic location determinants literature is unduly pessimistic regarding the economic prospects of rural areas. Most historic location research has treated rural areas as homogeneous regions. This study demonstrates that rural counties should be treated as differentiated sets of economic environments rather than as an aggregate. The locational potential of specific industries differs dramatically among differentiated rural regions. When examined in this way, a number of high‐growth industries surface as having development potential under specified rural conditions. In addition this work raises serious questions about the adequacy of product life‐cycle theory (Erickson 1976) and high‐technology filtering‐down theory (Glasmeier 1991) in identifying the variables critical to industrial location. This work indicates that neither small size nor remoteness is as limiting as suggested by earlier research.
Urban Encroachment, Economic Growth, and Land Values in the Urban Fringe
Authors: BROOMHALL DAVID
Published: July 2006

ABSTRACT This paper examines the impact of the local and national economy, and the rate of return on competing assets, on land prices in the urban fringe of the Scattle Primary Metropolitan Statistical Area (PMSA). The data are derived from a set of nearly all land sales in King County Washington between 1969 and 1984. The size of the data set allows for the neutralization of site specific influences by examining the monthly mean price of unimproved land. The results show that, like other traditional investments, land prices are sensitive to factors such as inflation and interest rates. Population pressures and local economic conditions influence urban fringe prices as well. Land further from the urban core is less sensitive to these impacts, presumably because it is too far away from economic activity to be considered for its value in future urban uses.
Megaherbivores and Southern Appalachian Grass Balds
Authors: WEIGL PETER D. , KNOWLES TRAVIS W.
Published: July 2006

ABSTRACT The persistence of the grass balds of the southern Appalachians represents an ecological enigma and a conservation dilemma. These high altitude treeless expanses, well known to native Americans and later grazed by white settlers, are now undergoing rapid succession which threatens a unique community of plants and animals. Whatever the balds' origin and in spite of the apparent antiquity of some, much of the botanical literature insists that they are largely an artifact of relatively recent human disturbance, and, except for rare plant preservation, deserve only limited conservation effort. Such an interpretation lacks both a historical perspective and an appreciation of the possible dynamic nature of this community. The presence of both rare, endemic plants and northern relicts requiring open habitat suggests a long evolutionary history. Also, balds that are still grazed today have maintained both their biota and size. We suggest that some balds are indeed ancient and were maintained during the late Pleistocene by mammalian herbivores. Excavations at Saltville, Virginia and elsewhere reveal the presence of up to 20 species of large herbivores, including mammoth, mastodon, bison, horse, tapir, musk ox, and ground sloth until 10,000 years ago. Thereafter, the mountains supported bison, elk, and deer until European settlement. It is likely that, as in many other parts of the world, this special natural community is the result of long‐term plant‐animal interactions and thus worthy of preservation. Such preservation might best be affected by the use of wild and/or domestic herbivores.
Wildlife Management, Surface Mining, and Regional Planning
Authors: NIEMAN THOMAS J. , MERKIN ZINA R.
Published: July 2006

ABSTRACT Wildlife management, surface mining, and regional planning historically have had conflicting missions. The cooperative public/private venture which created the Robinson Forest and Cyprus‐Amax Wildlife Management Areas is presented as an example of how a regional perspective encourages a symbiotic relationship among these Functions. Wildlife management areas, as either an interim or final land use. are shown to incorporate development concepts which benefit the general public, the coal industry, and the environment. Examining the regional pattern or wildlife management areas and refuges confirms the appropriateness of the subject site for this use. It is suggested that the pattern of mined lands can be studied to identify other sites with potential to provide linkages between wildlife habitat areas and encourage reclamation of such sites to the “fish and wildlife” postmining land use. Such reclamation strategies should be pursued within a long‐term planning framework. More research is needed to recreate specific habitat types on drastically disturbed land and planning is needed to assure that sensitive habitats or species arc located away from zones likely to undergo future development. Use of geographic information systems to integrate existing environmental information could make such studies more effective.
NAFTA and Industrial Adjustment: A Specific‐Factors Model of Production
Authors: THOMPSON HENRY
Published: July 2006

The North American Free Trade Agreement (NAFTA) will continue to attract political debate as U.S. manufacturing industries adjust in the face of increased import competition and export opportunities. This study applies the specific factors model of production to manufacturing industries in Alabama to examine the pending adjustment. As industrial prices change, there will be small output adjustments in the short run and downward pressure on the wages of production workers. Projected changes in industrial investment will lead to substantial long‐run output adjustments.
Density and the Journey to Work
Authors: LEVINSON DAVID M. , KUMAR AJAY
Published: July 2006

ABSTRACT
This paper evaluates the influence of residential density on commuting behavior across U.S. cities while controlling for available opportunities, the technology of transportation infrastructure, and individual socio‐economic and demographic characteristics. The measures of metropolitan and local density are addressed separately. It is suggested that metropolitan residential density serves principally as a surrogate for city size. Markets react to high interaction costs found in large cities by raising density rather than density being a cause of those high costs. Local residential density measures relative location (accessibility) within the metropolitan region as well as indexing the level of congestion. Regressions are conducted to predict commuting time, speed, and distance, by mode of travel on a cross‐section of individuals nationally and city by city. The results indicate that residential density in the area around the tripmaker's home is an important factor: the higher the density the lower the speed and the shorter the distance. However, density's effect on travel time is ambiguous; speed and distance are offsetting effects on time. The paper suggests a threshold density at which the decrease in distance is overtaken by the congestion effects, resulting in a residential density between 7,500 and 10,000 persons per square mile (neither the highest nor lowest) with the shortest duration auto commutes.
Cities and the ‘War on Terror’
Authors: GRAHAM STEPHEN
Published: July 2006

Programmes 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

Budding 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.
The rise of post‐imperial populism: The case of right‐wing Euroscepticism in Britain
Authors: GIFFORD CHRIS
Published: July 2006

Abstract.  Recent approaches to contemporary Euroscepticism have explained it in terms of the politics of opposition and peripherality characteristic of competitive party systems. Euroscepticism becomes a central strategy by which non‐mainstream parties or factions within mainstream parties attempt to gain political advantage. In the British case, there has been a focus on the influence Eurosceptic factionalism can have within a first‐past‐the‐post parliamentary system. This article challenges explanations of British Euroscepticism in terms of the politics of opposition and the workings of the party system. Instead, it is proposed that a structural crisis of British party politics has allowed Euroscepticism to enter the political mainstream. The author conceives of Euroscepticism as a distinct and powerful national movement asserting conceptions of Britain's exceptional national identity. This is viewed as part of a post‐imperial crisis that shifts parties, and factions within parties, towards populist forms of legitimation that have weakened possibilities for stable and coherent political leadership over European integration. Consequently, mainstream parties have struggled to protect themselves against the ideological influence of this populist Euroscepticism. This is particularly evident during periods of Eurosceptic mobilization, and is demonstrated in this article through the examination of the extensive role played by right‐wing Eurosceptic forces during the attempt by the Major Government to ratify the Maastricht Treaty.