bluuebunny/crossref_metadata_2025 huggingface dataset:
SPIROMETRIC CHANGES AFTER PLEURAL DECORTICATION IN YOUNG ADULTS
Authors: Gorur Rauf , Yildizhan Akin , Yiyit Nurettin , Kutlu Ali , Sonmez Guner , Isitmangil Turgut
Published: May 2007

Background:  The collection of pleural fluid and thickened pleura restrict the movement and expansion of lung. The main treatment strategy is lung decortication for the thickened pleura. The aim of this study was to investigate lung functions before and after pleural decortication in young adults.

Methods:  A total of 63 patients with thickened pleura were retrospectively evaluated. Before the operation, patients with tuberculosis (n = 36) were treated with anti‐tuberculosis therapy for 3–6 months. Patients with non‐tuberculosis causes (n = 27) had been treated with broad‐spectrum antibiotics. Forced expiratory volume in 1 s (FEV1, %), forced vital capacity (%) and vital capacity (litre) were measured before and after decortication.

Results:  Spirometric parameters FEV1 (68.1 ± 16.7 vs 71.01 ± 14.4), forced vital capacity (67.6 ± 16.4 vs 71.3 ± 14.4) and vital capacity (2.6 ± 0.6 vs 2.8 ± 0.7) significantly improved after the operation (P ± 0.01). Spirometric changes were not significantly different between tuberculosis and non‐tuberculosis groups.

Conclusion:  Pleural decortication may improve the lung restoration in patients with thickened pleura and also improve lung functions significantly in young adults.
Chloris polydactyla (L.) Sw., a perennial Poaceae weed: Emergence, seed production, and its management in Brazil
Authors: BRIGHENTI ALEXANDRE , VOLL ELEMAR , GAZZIERO DIONÍSIO L. P.
Published: May 2007

Experiments were conducted to evaluate the plant emergence and seed production of Chloris polydactyla and the efficacy of herbicides for its control. The plants emerged mainly when the seeds were placed on the soil surface at ≤ 3 cm depth. Isolated plants produced a great amount of seeds. The pre‐emergence herbicides, acetochlor, atrazine + simazine, s‐metolachlor, alachlor, and trifluralin, were effective for C. polydactyla control. The postemergence herbicides, clodinafop‐propargil, haloxyfop‐methyl, clethodim, fluazifop‐p‐butil, tepraloxydim, sethoxydim, and quizalofop‐p‐tefuril showed satisfactory control of the plants at a 20 cm height with six leaves. During the flowering stage (85 cm plant height), only glyphosate was effective in controlling C. polydactyla.
The functional role of biodiversity in ecosystems: incorporating trophic complexity
Authors: Duffy J. Emmett , Cardinale Bradley J. , France Kristin E. , McIntyre Peter B. , Thébault Elisa , Loreau Michel
Published: May 2007

Understanding how biodiversity affects functioning of ecosystems requires integrating diversity within trophic levels (horizontal diversity) and across trophic levels (vertical diversity, including food chain length and omnivory). We review theoretical and experimental progress toward this goal. Generally, experiments show that biomass and resource use increase similarly with horizontal diversity of either producers or consumers. Among prey, higher diversity often increases resistance to predation, due to increased probability of including inedible species and reduced efficiency of specialist predators confronted with diverse prey. Among predators, changing diversity can cascade to affect plant biomass, but the strength and sign of this effect depend on the degree of omnivory and prey behaviour. Horizontal and vertical diversity also interact: adding a trophic level can qualitatively change diversity effects at adjacent levels. Multitrophic interactions produce a richer variety of diversity‐functioning relationships than the monotonic changes predicted for single trophic levels. This complexity depends on the degree of consumer dietary generalism, trade‐offs between competitive ability and resistance to predation, intraguild predation and openness to migration. Although complementarity and selection effects occur in both animals and plants, few studies have conclusively documented the mechanisms mediating diversity effects. Understanding how biodiversity affects functioning of complex ecosystems will benefit from integrating theory and experiments with simulations and network‐based approaches.
Resistance management in a native plant: nicotine prevents herbivores from compensating for plant protease inhibitors
Authors: Steppuhn Anke , Baldwin Ian T.
Published: May 2007

Plants deploy chemical defenses in complex mixtures, which are thought to be adaptive, but experimental tests have used artificial diets rather than plants. Herbivore attack on Nicotiana attenuata rapidly increases the production and accumulation of trypsin proteinase inhibitors (TPI) and the toxic alkaloid nicotine. By transgenically silencing their respective biosynthetic genes, we were able to abolish TPI activity and reduce inducible nicotine by 85%. Nicotine production was not affected by silencing pi or vice versa, and transformation did not alter levels of other metabolites examined. Spodoptera exigua, a native generalist herbivore that can compensate for heterologous TPI expression, performed better on TPI‐ or nicotine‐deficient plants compared with the wild‐type. Because of a compensatory feeding response to TPI when nicotine is absent, larvae performed better on nicotine‐deficient plants than they did on plants silenced in both defenses. The antifeedant toxin, nicotine, prevents this compensatory response. We conclude that N. attenuata counters an insect adaptation with a defensive synergism.
Species–area relationships from a spatially explicit neutral model in an infinite landscape
Authors: Rosindell James , Cornell Stephen J.
Published: May 2007

We use recently developed technical methods to study species–area relationships from a spatially explicit extension of Hubbell's neutral model on an infinite landscape. Our model includes variable dispersal distances and exhibits qualitatively different behaviour from the cases of nearest‐neighbour dispersal and finite periodic landscapes that have previously been studied. We show that different dispersal distances and even different dispersal kernels produce identical species–area curves up to rescaling of the two axes. This scaling property provides a straightforward method for fitting the model to empirical data. The species–area curves display all three phases observed empirically and enable the exponent describing the power law relationship for species–area curves to be identified as the gradient at the central phase. This exponent can take all values between 0 and 1 and is given by a simple function of the speciation rate, independent of all other model variables.
The effects of dietary lycopene supplementation on human seminal plasma
Authors: Goyal Anuj , Chopra Mridula , Lwaleed Bashir A. , Birch Brian , Cooper Alan J.
Published: May 2007

OBJECTIVE

To investigate whether lycopene levels in blood and seminal plasma increase after dietary supplementation with a natural source of the compound, and whether any potential increase of lycopene levels in semen translates into increased free‐radical trapping capacity in the seminal plasma.

METHODS

Reactive oxygen species are detrimental to the health and function of spermatozoa. Semen contains enzymatic and non‐enzymatic defence mechanisms to combat such species, and lycopene, a dietary antioxidant, forms part of the non‐enzymatic arm. Immuno‐infertile men have significantly lower levels of lycopene in their semen, and oral lycopene therapy can improve various seminal variables in idiopathic infertility. Whether this improvement is a direct consequence of increased lycopene levels in semen, resulting in an increased radical scavenging ability, remains unknown. Blood and seminal lycopene levels were measured in healthy volunteers, using high‐performance liquid chromatography, before and after a period of dietary supplementation. The antioxidant capacity of seminal plasma was also assayed to determine if supplementation results in a measurable increase in seminal radical scavenging ability.

RESULTS

There were statistically significant increases in blood and seminal plasma lycopene levels after dietary supplementation. The increase in seminal and blood lycopene levels showed a strong positive correlation (r = 0.84, P < 0.05). There was no measurable increase in the total radical scavenging capacity of semen.

CONCLUSION

This study confirms the presence of lycopene in human semen, the levels of which can be significantly increased after dietary supplementation with a natural source of lycopene. Further studies to establish whether this would also be the case in infertile men, with possible associated improvements in their seminal quality, are warranted.
Apoptosis induction is associated with decreased NHE1 expression in neonatal unilateral ureteric obstruction
Authors: Manucha Walter , Carrizo Liliana , Ruete Celeste , Vallés Patricia G.
Published: May 2007

OBJECTIVE

To examine the participation of NHE1 in the regulation of the apoptotic response in neonatal obstruction, as the ubiquitously expressed NHE1 isoform is an important component of regulatory volume increase.

MATERIALS AND METHODS

Rats had a unilateral ureteric obstruction (UUO) or a sham operation, and the kidneys were harvested 5 and 14 days afterward. Cellular apoptosis in proximal tubules (PT) and collecting ducts (CD) was assessed using a standard assay, and NHE1 expression in the renal cortex assessed using reverse transcription‐polymerase chain reaction and Western blots. Mitochondrial apoptosis was evaluated by Bax/BcL2 expression, and caspase‐3 expression and activity. In addition, we evaluated the in vivo administration of increasing doses of 5‐(N‐ethyl‐N‐isopropyl)‐amiloride (EIPA) on NHE1 inhibition associated with the induction of apoptosis.

RESULTS

After 14 days there were consistently more apoptotic cells in CD than in PT, associated with a lower expression of NHE1 at the mRNA and protein levels. There was increased expression of the Bax/BcL2 ratio, linked to decreased pro‐caspase‐3 protein levels and with increased caspase‐3 activation. NHE1 inhibition by increasing doses of EIPA induced epithelial cell apoptosis and increased caspase‐3 activity in a dose‐dependent manner. After in vitro incubation with amiloride (100 mm) there was less NHE1 expression associated with reduced 32 kDa pro‐caspase‐3 protein levels. Kidneys obstructed for 5 days showed no changes in NHE1 expression or induction of apoptosis.

CONCLUSION

In neonatal obstruction, we suggest that the decreased NHE1 expression could be a signal‐transduction event participating in the induction of epithelial tubular cell apoptosis, through the regulation of the BcL‐2 gene family and activation of caspase‐3.
The impact of targeted training, a dedicated protocol and on‐site training material in reducing observer variability of prostate and transition zone dimensions measured by transrectal ultrasonography, in multicentre multinational clinical trials of men with symptomatic benign prostatic enlargement
Authors: Murphy Philip S. , Mills Ian W. , Crossland Anna , Patel Anup
Published: May 2007

OBJECTIVE

To assess the variability of a standardized protocol of transrectal ultrasonography (TRUS), with targeted training, and compare it to the variability in other multicentre clinical trials, as TRUS‐estimated total prostate volume (TPV) and transition zone volume (TZV) are considered important efficacy endpoints in assessing new drug therapies for benign prostatic enlargement (BPE), but standardizing TRUS remains a challenge in such studies.

PATIENTS AND METHODS

In all, 174 patients with BPE in the placebo arm of a 30‐centre clinical trial were analysed at baseline, 13 and 26 weeks with TRUS, to extract TPV and TZV values. All TRUS operators received training in the standardized methods, which was supplemented at the outset by a compact disc‐based video.

RESULTS

The mean (sd) changes from baseline in TPV at 13 and 26 weeks were − 2.9 (8.9) and −1.9 (8.5) mL, respectively; the respective mean changes from baseline in TZV were −1.2 (6.4) and + 0.7 (7.8) mL. For TPV, 80% of the measurements had differences of + 5.2 to −13.4 mL at 13 weeks, and + 8.0 to − 10.9 mL at 26 weeks. For TZV, 80% of the differences were + 5.8 to − 7.4 at 13 weeks, and + 9.3 to −6.5 mL at 26 weeks.

CONCLUSION

The performance of TRUS compared favourably with similar published multicentre studies, which we suggest relates in part to the careful implementation of the protocol. We showed that diligent implementation of a detailed protocol, supplemented by targeted training of investigators and provision of on‐site training material, promoted consistent acquisition and successful derivation of key clinical trial endpoints. Quantifying the variability of such endpoints will enable us to track deployment quality for future clinical trials, and will ensure that trials are sufficiently powered to define small changes in prostate size.
Suppression of bone density loss and bone turnover in patients with hormone‐sensitive prostate cancer and receiving zoledronic acid
Authors: Ryan Christopher W. , Huo Dezheng , Bylow Kathryn , Demers Laurence M. , Stadler Walter M. , Henderson Tara O. , Vogelzang Nicholas J.
Published: May 2007

OBJECTIVE

To report a randomized, placebo‐controlled study of treatment with zoledronic acid every 3 months in patients with hormone‐sensitive prostate cancer, both with and without bone metastases, to assess the effect on bone mineral density (BMD) and markers of bone turnover.

PATIENTS AND METHODS

Eligible patients included those with prostate cancer and on androgen‐deprivation therapy for <12 months. Patients received zoledronic acid 4 mg intravenously, or placebo, every 3 months for four treatments. BMD, urinary N‐telopeptides of type I collagen (NTX), and serum bone alkaline phosphatase (BAP) were measured every 3 months. In all, 42 patients were randomized.

RESULTS

After excluding BMD data from sites of known metastases, patients receiving zoledronic acid had a relative increase in BMD compared with those receiving placebo, of 4.2% and 7.1% at the femoral neck and lumbar spine, respectively. NTX and BAP decreased significantly in patients receiving zoledronic acid. NTX and BAP levels were significantly higher at baseline in patients with bone metastases than in those without.

CONCLUSIONS

Treatment with zoledronic acid every 3 months preserved bone density and suppressed markers of bone turnover in patients with androgen‐deprived prostate cancer, both with and without bone metastases.
Obesity as a predictor of biochemical recurrence and survival after radiation therapy for prostate cancer
Authors: Palma David , Pickles Tom , Tyldesley Scott ,   Prostate Cohort Outcomes Initiative
Published: May 2007

OBJECTIVE

Obesity has been demonstrated to predict biochemical progression in men undergoing radical prostatectomy for prostate adenocarcinoma, and is associated with a higher risk of biochemical and clinical relapse after radiation therapy (RT). We evaluated if obesity, determined by body mass index (BMI), is associated with adverse disease characteristics, pre‐treatment serum testosterone, biochemical disease free survival (bDFS), disease‐specific survival (DSS), or overall survival (OS) in patients undergoing radical external beam radiation therapy for prostate cancer.

PATIENTS AND METHODS

A cohort of 706 patients with localized prostate adenocarcinoma treated with RT between 1993 and 2001 were categorized as obese (BMI ≥ 30 kg/m2), overweight (BMI 25–29.9 kg/m2) or normal (BMI < 25 kg/m2). The association between BMI, disease characteristics, and progression were evaluated by Chi‐square and ANOVA tests, Kaplan‐Meier survival analysis, and Cox regression analysis.

RESULTS

195 patients (27.6%) were normal weight, 358 (50.7%) were overweight and 153 (21.7%) were obese. Obese men had lower serum testosterone levels than overweight and normal‐weight men (means 12.8, 14.1, and 15.7 nmol/L, respectively; p < 0.001). The BMI groups did not differ in Gleason score, pretreatment PSA, or stage. On multivariate analysis, BMI group was predictive of reduced bDFS (p = 0.02) and DSS (p = 0.008), with a trend toward reduced OS (p = 0.062).

CONCLUSION

Obesity was associated with lower serum testosterone levels but not with adverse pretreatment pathological features. Obese men have a higher risk of biochemical recurrence and prostate‐cancer specific death after RT.
Does intraprostatic inflammation have a role in the pathogenesis and progression of benign prostatic hyperplasia?
Authors: Mishra Vibhash C. , Allen Darrell J. , Nicolaou Christophoros , Sharif Haytham , Hudd Charles , Karim Omer M.A. , Motiwala Hanif G. , Laniado Marc E.
Published: May 2007

OBJECTIVE

To compare the incidence of acute and/or chronic intraprostatic inflammation (ACI) in men undergoing transurethral resection of the prostate (TURP) for urinary retention and lower urinary tract symptoms (LUTS), as recently a role was suggested for ACI in the pathogenesis and progression of BPH, and urinary retention is considered an endpoint in the natural history of this condition.

PATIENTS AND METHODS

Details of TURPs done between January 2003 and December 2005 at one institution were obtained from the operating theatre database. Patients were divided by indication (retention/LUTS). Clinical data and histology reports were then reviewed and bivariate and logistic regression used to compare the pathological features between these groups.

RESULTS

Of 406 patients, 374 had evaluable data; 70% of men with urinary retention had ACI, vs 45% of those with LUTS (P < 0.001). On logistic regression, the pathological factors associated with TURP for acute retention compared to that for LUTS were ACI, old age, and resection weight to a lesser degree.

CONCLUSION

Inflammation appears to be important in the pathogenesis and progression of BPH. In this study, the risk of urinary retention due to BPH was significantly greater in men with ACI than in those without, and the association of TURP for retention with ACI was stronger than that with prostate weight. This finding might offer new avenues for the medical treatment of men with LUTS due to BPH.
Type and spatial structure of distribution data and the perceived determinants of geographical gradients in ecology: the species richness of African birds
Authors: McPherson Jana M. , Jetz Walter
Published: May 2007

Aim Studies exploring the determinants of geographical gradients in the occurrence of species or their traits obtain data by: (1) overlaying species range maps; (2) mapping survey‐based species counts; or (3) superimposing models of individual species’ distributions. These data types have different spatial characteristics. We investigated whether these differences influence conclusions regarding postulated determinants of species richness patterns.

Location Our study examined terrestrial bird diversity patterns in 13 nations of southern and eastern Africa, spanning temperate to tropical climates.

Methods Four species richness maps were compiled based on range maps, field‐derived bird atlas data, logistic and autologistic distribution models. Ordinary and spatial regression models served to examine how well each of five hypotheses predicted patterns in each map. These hypotheses propose productivity, temperature, the heat–water balance, habitat heterogeneity and climatic stability as the predominant determinants of species richness.

Results The four richness maps portrayed broadly similar geographical patterns but, due to the nature of underlying data types, exhibited marked differences in spatial autocorrelation structure. These differences in spatial structure emerged as important in determining which hypothesis appeared most capable of explaining each map's patterns. This was true even when regressions accounted for spurious effects of spatial autocorrelation. Each richness map, therefore, identified a different hypothesis as the most likely cause of broad‐scale gradients in species diversity.

Main conclusions Because the ‘true’ spatial structure of species richness patterns remains elusive, firm conclusions regarding their underlying environmental drivers remain difficult. More broadly, our findings suggest that care should be taken to interpret putative determinants of large‐scale ecological gradients in light of the type and spatial characteristics of the underlying data. Indeed, closer scrutiny of these underlying data — here the distributions of individual species — andtheirenvironmental associations may offer important insights into the ultimate causes of observed broad‐scale patterns.
Increasing Long‐Term Market Returns: realising the potential of collective pension fund action
Authors: Thamotheram Raj , Wildsmith Helen
Published: May 2007

This paper seeks to offer a perspective from two practitioners on how the potential for retirement fund collaboration to improve long‐term market returns could be realised. After looking at the Universal Owner hypothesis and long‐term market returns, and their relevance to pension funds, the paper looks at collaboration to date, and the problems of collective action in general. After outlining several current collaborative opportunities, the ways in which they address the problems of collective action are outlined. The paper ends with a call to action to the leaders of the world’s largest pension funds.
THE GAP IS SEMANTIC, NOT EPISTEMOLOGICAL
Authors: D'Oro Giuseppina
Published: May 2007

This paper explores an alternative to the metaphysical challenge to physicalism posed by Jackson and Kripke and to the epistemological one exemplified by the positions of Nagel, Levine and McGinn. On this alternative the mind‐body gap is neither ontological nor epistemological, but semantic. I claim that it is because the gap is semantic that the mind‐body problem is a quintessentially philosophical problem that is not likely to wither away as our natural scientific knowledge advances.1
RESTRICTIVE CONSEQUENTIALISM AND REAL FRIENDSHIP
Authors: Henden Edmund
Published: May 2007

A familiar objection to restrictive consequentialism is that a restrictive consequentialist is incapable of having true friendships. In this paper I distinguish between an instrumentalist and a non‐instrumentalist version of this objection and argue that while the restrictive consequentialist can answer the non‐instrumentalist version, restrictive consequentialism may still seem vulnerable to the instrumentalist version. I then suggest a consequentialist reply that I argue also works against this version of the objection. Central to this reply is the claim that a restrictive consequentialist is capable of true friendship if the value she aims for is not merely seen as a function of her self‐regarding desires, but includes as a central constituent a form of objective value often referred to as ‘flourishing’ or ‘self‐realization’.1
DO FALLIBILIST ACCOUNTS OF THE GROWTH OF KNOWLEDGE UNDERESTIMATE AND ENDANGER SCIENCE?
Authors: Wettersten John
Published: May 2007

All fallibilist theories may appear to be defective, because they allegedly underestimate the security of at least some scientific knowledge and thereby leave science less defensible than it otherwise might be. When they call all scientific knowledge conjectural they may seem at first blush to underestimate the superiority of science vis a vis pseudo‐science. Fallibilists apparently fail to account for the fact that science turns theory into facts, because even “facts” are held only provisionally. This impression is false: the relatively secure establishment of facts can be accounted for with a fallibilist view. After theories have been honed through sharp criticism, there is often no reason to doubt some aspects of them. These aspects are what we regard to be factual knowledge, even though these facts are also provisionally accepted as such. We then explain the newly won factual knowledge with deeper theories, which often correct our factual knowledge in spite of its apparent security. Theories of justification add nothing useful to the fallibilists' observation that science finds the best theories because it has the highest standards of criticism. Fallibilist theories today give the best account and defence of science. We may abandon the quest for some kind of assurance that goes beyond the determination that some theory can answer all known objections to it and take up more interesting problems, such as how we can find new objections and how criticism may be improved and made institutionally secure.1
A kernel‐based method for nonparametric estimation of variograms
Authors: Yu Keming , Mateu Jorge , Porcu Emilio
Published: May 2007

Variogram estimation plays an important role in many areas of spatial statistics. Potential areas of application include biology, ecology, economics and meteorology. However, it is common that, for example under highly correlated patterns, traditional estimators can not reflect all the spatial features or dependencies. In this paper, we present an alternative distribution‐free estimator based on nearest‐neighbour estimation with a non‐constant smoothing field that is better able to adapt to spatially varying features of the data pattern. We present a simulation study to compare our new estimator to a nearest‐neighbour estimator built with a constant smoothing parameter and to the classical variogram estimator. We apply our method to analyze two ecological data sets.
Interarrival times in a counting process and bird watching
Authors: Anevski Dragi
Published: May 2007

We determine simple approximate relations between the distributions of the interarrival times and the total time of a stopped counting process, under the assumption of small intensities. These relations suggest applying recent results for nonparametric estimation of monotone and convex densities. The results are applied to estimating the distribution of the period of stay of migrating birds.
An exact non‐iterative sampling procedure for discrete missing data problems
Authors: Tian Guo‐Liang , Tan Ming , Ng Kai Wang
Published: May 2007

Many statistical problems can be formulated as discrete missing data problems (MDPs). Examples include change‐point problems, capture and recapture models, sample survey with non‐response, zero‐inflated Poisson models, medical screening/diagnostic tests and bioassay. This paper proposes an exact non‐iterative sampling algorithm to obtain independently and identically distributed (i.i.d.) samples from posterior distribution in discrete MDPs. The new algorithm is essentially a conditional sampling, thus completely avoiding problems of convergence and slow convergence in iterative algorithms such as Markov chain Monte Carlo. Different from the general inverse Bayes formulae (IBF) sampler of Tan, Tian and Ng (Statistica Sinica,13, 2003, 625), the implementation of the new algorithm requires neither the expectation maximization nor the sampling importance resampling algorithms. The key idea is to first utilize the sampling‐wise IBF to derive the conditional distribution of the missing data given the observed data, and then to draw i.i.d. samples from the complete‐data posterior distribution. We first illustrate the method with a performing example and then apply the method to contingency tables with one supplemental margin for an human immunodeficiency virus study.
Speaking English in Finnish content‐based classrooms
Authors: NIKULA TARJA
Published: May 2007

ABSTRACT:  CLIL (Content and Language Integrated Learning) is a term widely used in Europe to refer to different forms of content based education, often conducted in English. Earlier research on CLIL has tended to focus on matters of language learning or content mastery rather than on details of classroom interaction. This paper investigates how English is used in Finnish biology and physics CLIL classrooms. Classrooms are approached from a discourse‐pragmatic perspective which involves close attention to social and interpersonal aspects of language use as it unfolds in authentic settings. The findings suggest that CLIL students claim ownership of English by the way they confidently use it as a resource for the construction of classroom activities. Students' code switching practices are another indication that they ascribe to an identity as users rather than as learners of English. Instead of using Finnish when their skills in English fail them, students use the L1 for affective functions; and the way in which they slip in and out of English and Finnish indicates that they view the classroom as a bilingual space. The findings thus point towards emerging bilingualism among the students.
WORKINGS OF THE MELTING POT: SOCIAL NETWORKS AND THE EVOLUTION OF POPULATION ATTRIBUTES*
Authors: Brueckner Jan K. , Smirnov Oleg
Published: May 2007

ABSTRACT This paper links the two nascent economic literatures on social networks and cultural assimilation by investigating the evolution of population attributes in a simple model where agents are influenced by their acquaintances. The main conclusion of the analysis is that attributes converge to a melting‐pot equilibrium, where everyone is identical, provided the social network exhibits a sufficient degree of interconnectedness. When the model is extended to allow an expanding acquaintance set, convergence is guaranteed provided a weaker interconnectedness condition is satisfied, and convergence is rapid. If the intensity of interactions with acquaintances becomes endogenous, convergence (when it occurs) is slowed when agents prefer to interact with people like themselves and hastened when interaction with dissimilar agents is preferred.
SPACE AND THE MEASUREMENT OF INCOME SEGREGATION
Authors: Dawkins Casey J.
Published: May 2007

ABSTRACT This paper proposes a new spatial ordering index that that can be used to quantify the dependence of a given pattern of income segregation on the spatial arrangement of neighborhoods. Unlike other spatial measures of income segregation proposed in the literature, the spatial ordering index is less sensitive to the presence of outliers, satisfies the “principle of transfers,” and is flexible enough to quantify a variety of spatial patterns of segregation. The index can be interpreted in terms of the ratio of two covariances. Properties of the proposed measure are demonstrated using an example from the city of Baltimore, Maryland.
TESTING THE NEW ECONOMIC GEOGRAPHY: MIGRATIONS AND INDUSTRIAL AGGLOMERATIONS IN SPAIN*
Authors: Pons Jordi , Paluzie Elisenda , Silvestre Javier , Tirado Daniel A.
Published: May 2007

ABSTRACT This paper examines whether access to markets had a significant influence on migration choices of Spanish internal migrants in the interwar years. In it we perform a structural contrast of a New Economic Geography model that focuses on the forward linkage that links workers location choice with the geography of industrial production. The results prove the existence of a direct relation between workers' localization decisions and the market potential of the host regions. This could help to explain the apparently low intensity of internal migrations in Spain until the 1920s as well as its geography.
IS THERE A RURAL/URBAN EXPORT GAP?
Authors: Eff E. Anthon , Livingston Steven G.
Published: May 2007

ABSTRACT There is growing concern, particularly in policy circles, that rural manufacturing plants may be less likely to export than metro area plants, and that this may exacerbate the economic difficulties of rural America. A variety of reasons have been offered to expect this export gap, but little empirical work has been done. Using a database of all manufacturing establishments in seven southeastern states and the county and/or zip code‐level characteristics of their environment, we find that rural plants are indeed somewhat less likely to export than their urban counterparts. Though there are several explanations for the existence of this gap, factors specific to the rural environment—lower levels of human capital and information externalities—are its largest source.
Is Governance Reform a Catalyst for Development?
Authors: GOLDSMITH ARTHUR A.
Published: May 2007

International development agencies contend developing countries can boost rates of economic growth by introducing “good governance” measures. However, close analysis of specific governance reforms and economic turning points in the United States (when it was a developing country), Argentina, Mauritius, and Jamaica suggests that the agencies underestimate the time and political effort required to change governance, and overestimate the economic impact. Counter to optimistic claims about how much “institutions matter,” these carefully selected cases imply that greater transparency, accountability, and participation are often a result, rather than a direct cause of faster development. Furthermore, they show that closed institutions may be a satisfactory platform for rapid growth, provided those institutions open over time. Policymakers need to understand these processes better before counting on governance reforms to be the springboard out of poverty for most developing countries today.
What’s in a Name? A Critique of ‘Colonias’ in the United States
Authors: MUKHIJA VINIT , MONKKONEN PAAVO
Published: May 2007

‘Colonias’ in the United States are a relatively recent phenomenon for planning practitioners and scholars. Most of the focus of policy and literature has been on the unregulated, substandard settlements in Texas, New Mexico and Arizona. Past studies of colonias in the three states have criticized policy efficacy and questioned whether colonias are appropriately or adequately defined. Our objective in this essay is complementary. We draw from the literature, and our research in California, to explain and share our concerns with the policy practice of naming settlements with poor infrastructure and living conditions as colonias, a Spanish‐language name. We argue that the name can be misleading, prejudiced and risks being detrimental. We discuss our misgivings about federal public policy using a non‐English title for labeling substandard settlements, and suggest that scholars and policymakers need to revisit the terminology.

Les colonias constituent un phénomène relativement récent aux Etats‐Unis pour les acteurs et chercheurs en aménagement. La plupart des politiques et publications se sont intéressées aux implantations sauvages de qualité déplorable apparues au Texas, au Nouveau Mexique et en Arizona. Les études existantes sur les colonias de ces trois Etats ont remis en cause l’efficacité de la politique publique et la pertinence de la définition donnée au terme colonias. Cet essai vise à les compléter. A partir des publications et de nos recherches en Californie, il explique et expose notre inquiétude de voir la pratique politique désigner par colonias, un nom espagnol, des implantations aux infrastructures et conditions de vie médiocres. A notre avis, cette appellation peut être trompeuse, porteuse de préjugés et potentiellement néfaste. L’article soumet nos interrogations vis‐à‐vis d’une politique publique fédérale qui emploie une désignation en langue étrangère pour cataloguer des implantations d’habitats de qualité inférieure, et invite chercheurs et décideurs politiques à revisiter cette terminologie.
Reflections on Place and Place‐making in the Cities of China
Authors: FRIEDMANN JOHN
Published: May 2007

This article is about the small spaces of the city we call ‘places’. Places are shaped by being lived in; they are spaces of encounter where the little histories of the city are played out. They are, of course, also shaped by the state through planning, supervision, ordinances, and so forth. The patterns and rhythms of life in the small spaces of the city are therefore not simply a straightforward projection of civil life. Places are also sites of resistance, contestation, and actions that are often thought to be illegal by the (local) state. After introducing the concept of place, the remainder of this article is a reflection on places and place‐making (but also place‐breaking) in urban China. Because the patterns and rhythms of urban life have continuity, however, my approach to their study was historical. The story told here is roughly divided into four major periods: Imperial China, Republican China, the People’s Republic under Mao Zedong, and the reform period from about 1980 onward. I then return to the concepts of place and place‐making with which I began, summarizing my findings and suggesting some topics for further research.

Cet article traite des petits espaces de la ville qu’on appelle des ‘lieux’. Les lieux sont modelés par la vie qui s’y déroule; ce sont des espaces de rencontre où se jouent les petites histoires d’une ville. Bien sûr, ils sont aussi façonnés par l’Etat, à travers l’aménagement, le contrôle, les règlements, etc. Les modèles et rythmes de vie dans les petits espaces urbains ne sont donc pas une projection pure de la vie civique. Ce sont aussi des scènes de résistance, de contestation et d’actions souvent jugées illégales par les autorités (locales). Après le concept de lieu, l’article présente une réflexion sur les lieux et leur fabrication (ainsi que leur fracture) dans la Chine urbaine. Les modèles et rythmes de la vie urbaine présentant une continuité, l’approche appliquée à leur étude est historique. Le récit rapporté se décompose en quatre grandes périodes: la Chine impériale, la Chine républicaine, la République populaire de Mao Zedong et l’ère réformatrice depuis 1980 environ. L’article revient ensuite sur les concepts de lieux et de fabrication de lieux en résumant les résultats obtenus et en suggérant quelques thèmes de recherche à approfondir.
The Potential Contribution of the Field of Organizational Development to Crisis Management
Authors: Lalonde Carole
Published: May 2007

This paper explores the possibilities of cross‐disciplinarity between organization development and crisis management. The departure point of our reflection is that crisis management as a field currently faces two limitations. First, two major trends have characterized this field to date: the sociological analysis of organizational contingencies which focus on disasters as social events and the crisis management planning which emphasizes the development of techniques to master hazards. Despite what we have learned from these approaches, neither seems to lead to a crisis management learning model that fosters organizational resilience in coping with crises. Second, researchers have studied a number of events as single case studies but have not synthesized these case studies. Consequently, each crisis seems idiosyncratic and administrators tend to repeat the same inefficient patterns when a crisis occurs. The research proposal presented in this paper aims to remove these limitations by bringing together two apparently opposing fields of study, that of crisis management, characterized by what are perceived as specific events, and that of organizational development, characterized by the strengthening of organizations' capacities to cope with lasting changes. This paper proposes to explore their potential to work together theoretically and empirically through a research design. We conclude on how this proposal meets the challenges of a new research agenda in the 21st century.
RNAi– induced silencing of the plasma membrane Ca2+– ATPase 2 in neuronal cells: effects on Ca2+ homeostasis and cell viability
Authors: Fernandes Denzyl , Zaidi Asma , Bean Jennifer , Hui Dongwei , Michaelis Mary L.
Published: May 2007

Intraneuronal calcium ([Ca2+]i) regulation is altered in aging brain, possibly because of the changes in critical Ca2+ transporters. We previously reported that the levels of the plasma membrane Ca2+‐ATPase (PMCA) and the Vmax for enzyme activity are significantly reduced in synaptic membranes in aging rat brain. The goal of these studies was to use RNAi techniques to suppress expression of a major neuronal isoform, PMCA2, in neurons in culture to determine the potential functional consequences of a decrease in PMCA activity. Embryonic rat brain neurons and SH‐SY5Y neuroblastoma cells were transfected with in vitro– transcribed short interfering RNA or a short hairpin RNA expressing vector, respectively, leading to 80% suppression of PMCA2 expression within 48 h. Fluorescence ratio imaging of free [Ca2+]i revealed that primary neurons with reduced PMCA2 expression had higher basal [Ca2+]i, slower recovery from KCl‐induced Ca2+ transients, and incomplete return to pre‐stimulation Ca2+ levels. Primary neurons and SH‐SY5Y cells with PMCA2 suppression both exhibited significantly greater vulnerability to the toxicity of various stresses. Our results indicate that a loss of PMCA such as occurs in aging brain likely leads to subtle disruptions in normal Ca2+ signaling and enhanced susceptibility to stresses that can alter the regulation of Ca2+ homeostasis.
Paradoxical modulation of short‐term facilitation of dopamine release by dopamine autoreceptors
Authors: Kita Justin M. , Parker Lauren E. , Phillips Paul E. M. , Garris Paul A. , Wightman R. Mark
Published: May 2007

Electrophysiological studies have demonstrated that dopaminergic neurons burst fire during certain aspects of reward‐related behavior; however, the correlation between dopamine release and cell firing is unclear. When complex stimulation patterns that mimic intracranial self‐stimulation were employed, dopamine release was shown to exhibit facilitated as well as depressive components (Montague et al. 2004). Understanding the biological mechanisms underlying these variations in dopamine release is necessary to unravel the correlation between unit activity and neurotransmitter release. The dopamine autoreceptor provides negative feedback to dopamine release, inhibiting release on the time scale of a few seconds. Therefore, we investigated this D2 receptor to see whether it is one of the biological mechanisms responsible for the history‐dependent modulation of dopamine release. Striatal dopamine release in anesthetized rats was evoked with stimulus trains that were designed to promote the variability of dopamine release. Consistent with the well established D2‐mediated autoinhibition, the short‐term depressive component of dopamine release was blocked by raclopride, a D2 antagonist, and enhanced by quinpirole, a D2‐receptor agonist. Surprisingly, these same drugs exerted a similar effect on the short‐term facilitated component: a decrease with raclopride and an increase with quinpirole. These data demonstrate that the commanding control exerted by dopamine autoreceptors over short‐term neuroadaptation of dopamine release involves both inhibitory and paradoxically, facilitatory components.
Regulation of PI3K/Akt/GSK‐3 pathway by cannabinoids in the brain
Authors: Ozaita Andrés , Puighermanal Emma , Maldonado Rafael
Published: May 2007

Delta9‐tetrahydrocannabinol (THC), the main psychoactive component in Cannabis sativa preparations, exerts its central effects mainly through the G‐protein coupled receptor CB1, a component of the endocannabinoid system. Several in vitro and in vivo studies have reported neuroprotective effects of cannabinoids in excitotoxicity and neurodegeneration models. However, the intraneuronal signaling pathways activated in vivo by THC underlying its central effects remain poorly understood. We report that THC acute administration (10 mg/kg, i.p.) increases the phosphorylation of Akt in mouse hippocampus, striatum, and cerebellum. This phosphorylation was mediated by CB1 receptors as it was blocked by the selective CB1 antagonist rimonabant. Moreover, PI3K inhibition by wortmannin abrogated THC‐induced phosphorylation of Akt, but blockade of extracellular signal‐regulated protein kinases by SL327 did not modify this activation/phosphorylation of Akt. Moreover, administration of the dopaminergic D1 (SCH 23390) and D2 (raclopride) receptor antagonists did not block the activation of PI3K/Akt pathway induced in the striatum by cannabinoid receptor stimulation, suggesting that this effect is independent of the dopaminergic system. In addition, THC increased the phosphorylation of glycogen synthase kinase 3 beta. Therefore, activation of the PI3K/Akt/GSK‐3 signaling pathway may be related to the in vivo neuroprotective properties attributed to cannabinoids.
Sources of variation in haematocrit in birds
Authors: FAIR JEANNE , WHITAKER SHAYNA , PEARSON BRANDON
Published: May 2007

The validity of the haematocrit or packed cell volume as an indicator of condition in wild birds has recently been questioned. We reviewed over 300 published papers on haematocrit values for wild birds. These studies show that changes in haematocrit could be caused by a number of different natural factors that include age, sex, geographical elevation, energy expenditure, parasitism, nutrition and genetics. Haematocrit also increased with age from hatching, due to increased erythropoiesis, so that adult birds generally have greater haematocrit values than nestlings or juveniles. Haematocrit values were either independent of elevation or increased with elevation. A meta‐analysis of 36 studies showed no difference in haematocrit between the sexes. Relationships between haematocrit value and both energy expenditure and parasitic infection vary between studies. In temperate climates, haematocrit tended to be higher in winter than in summer, which may be due to dehydration or increased oxygen demand caused by thermogenesis, moult or acquisition of reproductive status. Our review indicates that the use of haematocrit as a sole indicator of condition or health could lead to incorrect conclusions if natural factors that can affect haematocrit are not taken into consideration.
Effects of sleep deprivation on anaerobic exercise‐induced changes in auditory brainstem evoked potentials
Authors: Öztürk Levent , Bulut Erdoğan , Vardar Selma Arzu , Uzun Cem
Published: May 2007

Background  The present study was designed to assess how anaerobic exercise affects auditory brainstem response (ABR) parameters, and whether one night of sleep deprivation could alter these possible exercise‐induced changes in ABRs.

Methods  Seven healthy, audiologically normal male students (mean age 22·4 ± 1·0 years) participated in the study. All subjects underwent anaerobic Wingate test for three times: (i) baseline, (ii) following a full‐night of habitual sleep and (iii) following one night of sleep deprivation. ABR measurements were performed before and after the second and the third Wingate tests. Oral body temperatures were recorded at the beginning of all ABR measurements.

Results  The latencies of wave III and V significantly shortened by anaerobic loading performed in the day after habitual sleep (4·13 ± 0·10 versus 4·01 ± 0·17 ms, P<0·02; and 5·84 ± 0·26 versus 5·65 ± 0·23 ms, P<0·03, respectively). One night of total sleep deprivation shortened pre‐exercise latencies and altered exercise‐induced changes in ABRs.

Conclusion  The findings obtained in the present study show that acute anaerobic exercise is effective on ABR wave latencies independent from body temperature changes, and sleep deprivation has some modulatory effects on exercise‐induced changes in ABR.