bluuebunny/crossref_metadata_2025 huggingface dataset:
Varied presentations of pseudoxanthoma elasticum in a family
Authors: Sakata S , Su John C , Robertson S , Yin M , Chow CW
Published: November 2006

Abstract:  Pseudoxanthoma elasticum (PXE) is a hereditary disorder of elastic tissue. The characteristic skin changes are asymptomatic yellow papules around the neck and in body folds giving the skin a characteristic cobblestone appearance. The eyes, cardiovascular and gastrointestinal systems are also commonly involved. In this case‐series, we present a family of four children, three of whom demonstrated diverse manifestations of PXE. The first child presented with sudden death at age 3 and showed marked coronary and renal arterial intimal fibrosis with prominent fragmentation of the internal elastic lamina, initially attributed to idiopathic arterial calcification. The second child presented with clinical features and histology of the skin typical of PXE at age 11 and the third child, with abnormal, but non‐specific cardiological findings at age 8, which raised the possibility of an early stage of PXE. This report emphasizes the importance of considering pseudoxanthoma elasticum in diverse clinical settings, early diagnosis and appropriate screening for asymptomatic family members.
Organ‐specific endoglin (CD105) expression in the angiogenesis of human cancers
Authors: Minhajat Rahmawati , Mori Daisuke , Yamasaki Fumio , Sugita Yasuo , Satoh Toshimi , Tokunaga Osamu
Published: November 2006

Some markers of angiogenic endothelial cells are emerging as targets for cancer therapy. The present study compared the expression of CD105 with that of other endothelial markers in cancers from various organs. Surgically resected cancer tissues from 188 patients comprising brain (n = 17), lung (n = 38), breast (n = 30), stomach (n = 30), colon (n = 31), liver (n = 32), and kidney (n = 10) cancers were immunohistochemically analyzed on tissue microarrays using a panel of eight endothelial markers. CD31 was expressed in vascular endothelial cells in cancer lesions as well as in non‐cancerous areas (30–100%) in all core tissue samples. CD105 expression was intense and restricted to capillary endothelial cells in cancer lesions (>73%). In contrast, positive expression of CD105 was seen in <20% of non‐cancerous areas in the same organs. However, no significant difference in CD105 expression in vascular endothelial cells between cancer lesions and non‐cancerous areas from liver and renal cancer samples was found. Vascular endothelial growth factor (VEGF), Flt1, and Flk1 were also expressed, but only sporadically and in few samples (<30%), and transforming growth factor (TGF)‐β1 and TGF‐βRII were negative in vascular endothelial cells but generally positive in cancer cells. CD44 was strongly expressed in sinusoidal endothelial cells of the liver (90–100%). These results show that CD105 is expressed specifically in the tumor angiogenesis of brain, lung, breast, stomach, and colon cancers.
Bloodstream infections in a secondary and tertiary care hospital setting
Authors: Raymond N. J. , Blackmore T. K. , Humble M. W. , Jones M. R.
Published: November 2006

Background: Bloodstream infections (BSI) occurring in community and health‐care settings vary with the patient group and treatment of underlying medical conditions. We studied the clinical infectious syndromes occurring in patients with positive blood cultures routinely obtained at a regional secondary and tertiary care hospital.

Methods: BSI were categorized as either community‐acquired (C‐BSI), or health‐care‐associated (H‐BSI) acquired either as a (i) non‐inpatient (outpatient) or (ii) hospital inpatient. Clinical information was collected prospectively during the 1‐year study.

Results: There were 193 C‐BSI and 230 H‐BSI. The large majority of C‐BSI were caused by bacterial pathogens susceptible to narrow‐spectrum antibiotics, particularly in children. Cefuroxime was active against 90% of C‐BSI isolates and 46% of H‐BSI isolates, excluding anaerobes. Of all H‐BSI, the 35% occurring in outpatients had a similar source, microbiological cause and bacterial susceptibilities to the inpatients. H‐BSI were infrequently due to enterococci (4%), Candida (3%) or methicillin‐resistant Staphylococcus aureus (0.4%). No BSI were due to vancomycin‐resistant enterococci or extended‐spectrum β‐lactamase producing Enterobacteriaciae. I.v. catheters, predominantly central lines, were the source of 60% of all H‐BSI, mostly in haematology–oncology or neonatal patients. Mortality at 1 month was 12% overall for both C‐BSI and H‐BSI, varying markedly by underlying disease and increasing age (for C‐BSI).

Conclusion: In this population, C‐BSI have remained susceptible to narrow‐spectrum antibiotics, whereas H‐BSI due to multiresistant organisms were rare. Obtaining a history of recent medical procedures is important for community patients presenting with a BSI.
Mortality and airflow obstruction in asthma: a 17‐year follow‐up study
Authors: Panizza J. A. , James A. L. , Ryan G. , De Klerk N. , Finucane K. E.
Published: November 2006

Background: Asthma is associated with fixed airflow obstruction and an increased risk of death. The aim of this study was to relate asthma mortality and airflow obstruction to severity of asthma in a cohort of patients with chronic asthma studied over a 17‐year period.

Methods: In 1980, asthma severity based on symptoms, asthma duration, treatment and smoking habits were assessed and lung function was measured after maximal therapy in 89 patients. In 1997, mortality was recorded and 44 of 60 patients known to be alive were restudied.

Results: Eighteen patients had died: eight deaths were associated with asthma (seven occurred before and one after 1990). The risk of death was higher with decreased forced expiratory volume in 1 s (FEV1), increased FEV1 variability, age and treatment requirements but not symptom severity, at initial study. In the patients restudied, asthma severity and FEV1 variability decreased whereas the dose of inhaled corticosteriods increased 2.8‐fold. Highest FEV1 was negatively related to treatment score and smoking history at initial study, but not at follow up and was <80% predicted in 19 (43%) patients, 11 of whom had never smoked. The mean (±standard deviation) decrement in FEV1 was 32 ± 24 mL/year and correlated positively with FEV1 at initial study, smoking history, age of onset of asthma and treatment requirements at follow up.

Conclusion: In this cohort study, asthma was associated with chronic airflow obstruction and that with increased risk of mortality. Symptoms and mortality risk improved in association with increased reported use of inhaled corticosteroids; however, there was ongoing chronic airflow obstruction.
“I’m glad I’m not young anymore”
Authors: Allen R. K. A.
Published: November 2006

The author, a physician in late middle age reflects on his own medical career, the aging of those who have taught him and also of those whom he has taught. He describes the sense of ennui and déjà vu. The things that seemed important as a younger doctor seem less important. He has adopted a different paradigm and has come to see that both playfulness and integrity are essential ingredients for health. As a sailor, he more keenly appreciates the struggles our patients and colleagues have with illness and draws an analog between sailing and life.
Ice age legacies in the geographical distribution of tree species richness in Europe
Authors: Svenning Jens‐Christian , Skov Flemming
Published: November 2006

Aim This study uses a high‐resolution simulation of the Last Glacial Maximum (LGM) climate to assess: (1) whether LGM climate still affects the geographical species richness patterns in the European tree flora and (2) the relative importance of modern and LGM climate as controls of tree species richness in Europe.

Location The parts of Europe that were unglaciated during the LGM.

Methods Atlas data on the distributions of 55 tree species were linked with data on modern and LGM climate and climatic heterogeneity in a geographical information system with a 60‐km grid. Four measures of species richness were computed: total richness, and richness of the 18 most restricted species, 19 species of medium incidence (intermediate species) and 18 most widespread species. We used ordinary least‐squares regression and spatial autoregressive modelling to test and estimate the richness–climate relationships.

Results LGM climate constituted the best single set of explanatory variables for richness of restricted species, while modern climate and climatic heterogeneity was best for total and widespread species richness and richness of intermediate species, respectively. The autoregressive model with all climatic predictors was supported for all richness measures using an information‐theoretic approach, albeit only weakly so for total species richness. Among the strongest relationships were increases in total and intermediate richness with climatic heterogeneity and in restricted richness with LGM growing‐degree‐days. Partial regression showed that climatic heterogeneity accounted for the largest unique variation fraction for intermediate richness, while LGM climate was particularly important for restricted richness.

Main conclusions LGM climate appears to still affect geographical patterns of tree species richness in Europe, albeit the relative importance of modern and LGM climate depends on range size. Notably, LGM climate is a strong richness control for species with a restricted range, which appear to still be associated with their glacial refugia.
Political Development, Agriculture, and Ethnic Divisions: An African Perspective
Authors: Grabowski Richard
Published: November 2006

Abstract:  In this paper it is argued that political development is the key to long‐run growth in developing nations. Political development is seen to be dependent on the extent to which a state or ruling elite's income is earned or unearned. The availability of earned income is linked to the structure and productivity of the agricultural sector. Applying the analysis to the sub‐Saharan African experience involves taking into account three factors: the international environment, the ethnic division of societies as a result of colonization, and the urban bias which characterized the economic strategy of the newly independent African states. As a result, agriculture collapsed, the ruling elite became increasingly dependent on unearned income, political underdevelopment occurred. The collapse of state authority significantly impoverished the region and resulted in significant civil conflict. Any long‐run solution must incorporate a broad‐based expansion in agricultural productivity.
Analysis of Farmers' Preferences for Development Intervention Programs: A Case Study of Subsistence Farmers from East Ethiopian Highlands
Authors: Bekele Wagayehu
Published: November 2006

Abstract:  The aim of this paper is to better understand farmers' perception of the relevance of different development intervention programs. Farmers' subjective ranking of agricultural problems and their preference for development intervention are elicited using a stated preference method. The factors influencing these preferences are determined using a random utility model. The study is based on a survey conducted in the Hunde‐Lafto area of the East Ethiopian Highlands. Individual interviews were conducted with 145 randomly selected farm households using semi‐structured questionnaires. The study suggests that drought, soil erosion and shortage of cultivable land are high priority agricultural production problems for farmers. Low market prices for farm products and high prices of purchased inputs also came out as major problems for the majority of farmers. Farmers' preferences for development intervention fall into four major categories: market, irrigation, resettlement, and soil and water conservation. Multinomial logit analysis of the factors influencing these preferences revealed that farmer's specific socio‐economic circumstances and subjective ranking of agricultural problems play a major role. It is also shown that preferences for some interventions are complementary and need to be addressed simultaneously. Recognition and understanding of these factors, affecting the acceptability of development policies for micro level implementation, will have a significant contribution to improve macro level policy formulation.
Non‐parametric Diversity Indices of Technical Capability of African Countries
Authors: Amavilah Voxi Heinrich S.
Published: November 2006

Abstract:  Academic research often claims that the lack of technical capability undermines Africa's economic growth. Policy decisions based on that claim then recommend technological improvement, where technology is generally treated as a homogenous manna from the heaven. This paper outlines four, and calculates two, broad indices of the diversity of technical capability of 14 African countries based on nine common descriptors of technical capability. It finds technical capability to be heterogeneous both within and across countries, and concludes that performance policies that overlook diversity of technical capability are potentially misleading, ineffective, and perhaps even damaging (growth retarding).
Institutional Support for Collective Learning: Cluster Development in Kenya and Ghana
Authors: Oyelaran‐Oyeyinka Banji , Lal Kaushalesh
Published: November 2006

Abstract:  The study analyses the role of institutional infrastructural and collective learning in adoption of new technologies. The data for the study come from the Suame cluster in Ghana and the Kamukunji and Kariobangi clusters in Kenya. The clusters are dominated by micro and small enterprises (MSEs). The findings of the study suggest that policy measures need to be taken by governments in developing countries to improve the performance of MSEs. It is found that greater participation of the private sector is required in setting up training and information service centres within clusters. These institutions could provide need‐based skills for better usage of new technologies. This is more relevant for information and communication technologies (ICTs) such as e‐mail and the Internet. These institutions could also be useful in searching function‐ and job‐specific ICT tools which are not only expected to be efficient but cost effective. Such collective cluster initiatives are expected to result in better cluster performance.
CONCEPTUAL CLUSTERING AND CASE GENERALIZATION OF TWO‐DIMENSIONAL FORMS
Authors: Jänichen Silke , Perner Petra
Published: November 2006

Case‐based object recognition requires a general case of the object that should be detected. Real‐world applications such as the recognition of biological objects in images cannot be solved by one general case. A case base is necessary to handle the great natural variations in the appearance of these objects. In this paper, we will present how to learn a hierarchical case base of general cases. We present our conceptual clustering algorithm to learn groups of similar cases from a set of acquired structural cases of fungal spores. Due to its concept description, it explicitly supplies for each cluster a generalized case and a measure for the degree of its generalization. The resulting hierarchical case base is used for applications in the field of case‐based object recognition. We present results based on our application for health monitoring of biologically hazardous material.
PREDICTING INFLUENZA WAVES WITH HEALTH INSURANCE DATA
Authors: Schmidt Rainer , Waligora Tina , Gierl Lothar
Published: November 2006

In recent years, many of the most developed countries have started to create influenza surveillance systems, because influenza still is very costly, not just concerning the health systems, but also economically. In most of these systems statistical methods are applied, unfortunately with rather moderate results. In contrast to statistical methods case‐based reasoning explicitly uses former episodes. Because we already successfully applied our prognostic method, which combines case‐based reasoning (CBR) with temporal abstraction, to kidney functions, we use it again to forecast influenza. Because health centers collect extensive laboratory data but their availability is usually delayed for at least two weeks, we use quickly available data from the main German health insurance scheme. In this article, we propose the use of CBR for influenza forecast and we show promising results.
CASE‐BASED REASONING AND KNOWLEDGE DISCOVERY IN MEDICAL APPLICATIONS WITH TIME SERIES
Authors: Funk Peter , Xiong Ning
Published: November 2006

This paper discusses the role and integration of knowledge discovery (KD) in case‐based reasoning (CBR) systems. The general view is that KD is complementary to the task of knowledge retaining and it can be treated as a separate process outside the traditional CBR cycle. Unlike knowledge retaining that is mostly related to case‐specific experience, KD aims at the elicitation of new knowledge that is more general and valuable for improving the different CBR substeps. KD for CBR is exemplified by a real application scenario in medicine in which time series of patterns are to be analyzed and classified. As single pattern cannot convey sufficient information in the application, sequences of patterns are more adequate. Hence it is advantageous if sequences of patterns and their co‐occurrence with categories can be discovered. Evaluation with cases containing series classified into a number of categories and injected with indicator sequences shows that the approach is able to identify these key sequences. In a clinical applica‐ tion and a case library that is representative of the real world, these key sequences would improve the classification ability and may spawn clinical research to explain the co‐occurrence between certain sequences and classes.
2. Bayesian Inference for Hierarchical Age-Period-Cohort Models of Repeated Cross-Section Survey Data
Authors: Yang Yang
Published: November 2006

This study applies methods of Bayesian statistical inference to hierarchical APC models for the age-period-cohort analysis of repeated cross-section survey data. It examines the impacts of small sample sizes of birth cohorts and time periods and unbalanced data on statistical inferences based on the usual restricted maximum likelihood-empirical Bayes (REML-EB) estimators through Monte Carlo simulations. A full Bayesian analysis using Gibbs sampling and MCMC estimation is developed to assess the robustness of REML-EB inferences when this extra uncertainty is taken into account and the numbers of higher-level units are small. For a substantive illustration, it applies cross-classified random effects models to vocabulary test data from the General Social Survey (1974 to 2000). It is concluded that the decline in verbal ability for birth cohorts born after 1950 was correlated with the levels of newspaper reading and television watching. Avenues for future research on mixed APC models are discussed.
Multilateralising Regionalism: Spaghetti Bowls as Building Blocs on the Path to Global Free Trade
Authors: Baldwin Richard E.
Published: November 2006

This paper addresses the final steps to global free trade – what they might look like, what sort of political economy forces might drive them, and what the WTO might do to help. Two facts form the point of departure: (1) Regionalism is here to stay; world trade is regulated by a motley assortment of unilateral, bilateral and multilateral trade agreements; (2) this motley assortment is not the best way to organise world trade. Moving to global duty‐free trade will require a multilateralisation of regionalism. This paper presents the political economy logic of trade liberalisation and uses it to structure a narrative of world trade liberalisation since 1947. The logic is then used to project the world tariff map in 2010, arguing that the pattern will be marked by fractals – fuzzy, leaky trade blocs made up of fuzzy, leaky sub‐blocs (fuzzy since the proliferation of FTAs makes it impossible to draw sharp lines around the Big‐3 trade blocs, and leaky since some FTAs create free trade ‘canals’ linking the Big‐3 blocs). The paper then presents a novel political economy mechanism – spaghetti bowls as building blocs – whereby offshoring creates a force that encourages the multilateralisation of regionalism. Finally, the paper suggests three things the WTO might do to help multilateralise regionalism.
Trade Liberalisation, Economic Development and Poverty Alleviation
Authors: Sapsford David , Garikipati Supriya
Published: November 2006

In a distinguished career spanning more than four decades, Jagdish Bhagwati has made numerous contributions to both trade theory and trade policy analysis. The current paper focuses on Bhagwati's major contribution to the ongoing debate surrounding the influence of trade liberalisation upon economic development and its potential to alleviate poverty in the world's poorest economies. In order to highlight Bhagwati's contributions in these fields we focus on the arguments developed in two of his numerous landmark publications; first his seminal 1964 paper on the Pure Theory of International Trade and, second, his 2004 book entitled In Defense of Globalization. Although separated in time by some four decades we argue that these two publications, despite their very different characters, each demonstrate beyond doubt the significance of Bhagwati's work in improving our understanding of the true nature of international trade and its potential to address questions of global poverty.
Diaspora and Development
Authors: Wei Yingqi , Balasubramanyam V. N.
Published: November 2006

Jagdish Bhagwati's proposal for a ‘brains tax’ to be levied on the incomes of the diaspora from developing countries residing in the developed countries and the proceeds to be remitted to the countries of origin of the diaspora is well known. In recent years the voluntary contributions or remittances from the diaspora to their countries of origin have often been higher than the aid monies given to these countries. It is now increasingly recognised that the diaspora may have an active role to play in the development process of their countries of origin. They are not only a source of funds; they are also a rich source of skills and know‐how. This paper analyses the potential of the diaspora as agents of change in their countries of origin and argues that the social rate of return to a unit of diaspora investments may be higher than that for a unit of foreign direct investment from non‐diaspora sources.
Bhagwati and Ramaswami: Why it is a Classic
Authors: Panagariya Arvind
Published: November 2006

This paper expounds on a well‐known and widely influential paper ‘Domestic Distortions, Tariffs and the Theory of Optimum Subsidy’ (1963) by Bhagwati in collaboration with V. K. Ramaswami. The message of the paper, which set in trail a number of publications, was that in the case of a small open economy, distortions that steer the economy away from Pareto‐optimal outcomes should be dealt with at their source. The Bhagwati and Ramaswami paper established the case for free trade in the presence of domestic distortions, and proved wrong the received wisdom of the day that in the presence of distortions such as externalities, wage rigidities and distorted factor and product markets, a move from free trade to autarky might improve welfare. The article succinctly demonstrated that the correct policy intervention which avoided welfare losses was one which rectified a distortion at its source and is justly regarded as a classic. But in the profession of economics those who question received wisdom are regarded with scepticism at first and then with the riposte that it is all old wine served in new bottles. The Bhagwati‐Ramaswami breakthrough was met with the remark ‘it is all in Meade’. This paper takes issue with this judgement. The paper not only refutes the suggestion that the Bhagwati‐Ramaswami article has its origins in Meade but also provides a lucid and succinct exposition of Meade's analysis of divergences and shows how Bhagwati and Ramaswami's analysis is vastly different.
Effects of outliers on the identification and estimation of GARCH models
Authors: Carnero M. Angeles , Peña Daniel , Ruiz Esther
Published: November 2006

Abstract.  This paper analyses how outliers affect the identification of conditional heteroscedasticity and the estimation of generalized autoregressive conditionally heteroscedastic (GARCH) models. First, we derive the asymptotic biases of the sample autocorrelations of squared observations generated by stationary processes and show that the properties of some conditional homoscedasticity tests can be distorted. Second, we obtain the asymptotic and finite sample biases of the ordinary least squares (OLS) estimator of ARCH(p) models. The finite sample results are extended to generalized least squares (GLS), maximum likelihood (ML) and quasi‐maximum likelihood (QML) estimators of ARCH(p) and GARCH(1,1) models. Finally, we show that the estimated asymptotic standard deviations are biased estimates of the sample standard deviations.
A SIMPLE MODEL OF OPTIMAL TAX SYSTEMS: TAXATION, MEASUREMENT AND UNCERTAINTY*
Authors: DHAMI SANJIT , AL‐NOWAIHI ALI
Published: November 2006

The neglect of administrative issues is a serious limitation of optimal tax theory, with implications for its practical applicability. We focus on an important class of administrative problems, namely that the tax bases are measured with some error. We also consider the full set of tax instruments. We find that consumption taxes can perform the ‘social insurance role of taxation’, a role previously ascribed only to income taxes. A combination of income and consumption taxes can hedge income and measurement‐error risks better, relative to the imposition of either type of tax alone. The optimal tax rate is increasing in the precision with which the corresponding tax base is measured. The taxpayer engages in precautionary savings in response to income uncertainty and measurement problems. Differential commodity taxes tailored to the measurability characteristics of the different tax bases dominate uniform commodity taxes. However, as an economy becomes large, optimal taxes converge to uniform (or flat rate) taxes.
EXPLAINING THE EQUITY RISK PREMIUM*
Authors: LUNGU LAURIAN , MINFORD PATRICK
Published: November 2006

We develop a simple overlapping generations model in which the young have a choice in investing in equities or index‐linked bonds. Projections of share price uncertainty over a 30‐year period show that the risk associated with such long‐term investments predicts an equity premium that matches historical values. Moreover, we calibrate the model and show that it can predict up to the fourth moment of both the observed risk premium and the real rate of interest.
ON THE POSSIBILITY OF PARETO‐IMPROVING PENSION REFORM*
Authors: DAMJANOVIC TATIANA
Published: November 2006

The aim of this paper is twofold. First, it provides a simple framework for the analyses of the transitions between two steady states with different fiscal policies. This allows us to clarify the existing results on the possibility of Pareto‐improving transitions from pay‐as‐you‐go to fully funded pension systems. We show that the reduction in the marginal tax rate is a sufficient condition for the possibility of such pension reforms. Second, the paper investigates the features and the duration of the shortest Pareto‐improving pension reform in an open economy.
What Effect does Listening to Individual Children have on their Learning?
Authors: SMITH LINDSAY
Published: November 2006

In this article, the author reports the outcomes of studying a programme that provided 35 primary school children with weekly, individual, half‐hour listening and talking sessions with an adult over 10 weeks. The skilled adult ‘Listening Partners’ offered an open agenda and a private space away from the classroom. The children could use the session as they chose. The consequences of this intervention were measured against the experience of a control group of children. Evidence of change was collected by comparing results from a standard listening test, teacher assessments, National Curriculum assessments and behavioural records. The author explores two central questions: how does increasing the amount of time that a child has the individual, listening attention of an adult affect that child's capacity to listen, understand and respond constructively to what is said to them in a teaching and learning situation? Are there any other effects on children in school who receive this one‐to‐one attention? The study showed that the focused attention of a trusted adult provided children with opportunities to communicate, notably disclosing child protection issues that may otherwise have remained uninvestigated. Increasing the opportunities for children to experience being listened to by a skilled adult positively affected their educational progress. She argues that skilled listeners have a significant effect on children's learning and on some children's behaviour.
Sympathy for Pontius Pilate. Hemicrania in M. A. Bulgakov's The Master and Margarita
Authors: Zayas V , Mainardi F , Maggioni F , Zanchin G
Published: November 2006

The aim of this study was to explore the description of the migraine attack of Pontius Pilate (a character in the novel The Master and Margarita by M. A. Bulgakov). Some of its features are analysed in light of current migraine literature. It is hypothesized that, at least in part, this description is based on the personal experience of the novel's author. We studied and analysed the text of the novel, other works by Bulgakov, his biography, including his medical training and practice, and the recently published diaries of Bulgakov and his wife E. S. Bulgakova. The novel contains a comprehensive description of a migraine attack. It includes a prodrome/aura of osmophobia. Olfactory perception during or shortly before the migraine attack is altered to the point where neutral or even pleasant odours become unbearable. Bulgakov's extensive history of migraines is seen in his diary, the diary of his wife, letters and other literary works. This is one of the most detailed and extensive depictions of a migraine attack in literature, with osmophobia described with great emphasis. It is likely that Pilate's migraine is described based on the personal history of the novel's author.
Adolescent Disc Degeneration - No Headache Association
Authors: Laimi K , Erkintalo M , Metsähonkala L , Vahlberg T , Mikkelsson M , Sonninen P , Parkkola R , Aromaa M , Sillanpäa M , Rautava P , Anttila P , Salminen J
Published: November 2006

The objective of the study was to determine whether adolescents with headache have more disc degeneration in the cervical spine than headache-free controls. This study is part of a population-based follow-up study of adolescents with and without headache. At the age of 17 years, adolescents with headache at least three times a month ( N = 47) and adolescents with no headache ( N = 22) participated in a magnetic resonance imaging (MRI) study of the cervical spine. Of the 47 headache sufferers, 17 also had weekly neck pain and 30 had neck pain less than once a month. MRI scans were interpreted independently by three neuroradiologists. Disc degeneration was found in 67% of participants, with no difference between adolescents with and without headache. Most of the degenerative changes were located in the lower cervical spine. In adolescence, mild degenerative changes of the cervical spine are surprisingly common but do not contribute to headache.
Isolation and characterization of eight microsatellite loci in Leporinus macrocephalus (Characiformes: Anostomidae) and cross‐species amplification
Authors: MORELLI KARINA A. , REVALDAVES ELOISA , OLIVEIRA CLAUDIO , FORESTI FAUSTO
Published: November 2006

Leporinus macrocephalus is a species endemic to the Paraguay River basin and an important fishery resource, as well as a valuable species in aquaculture programs. A total of eight polymorphic microsatellite loci were isolated and characterized. A population survey was conducted involving 45 specimens whereby a large number of alleles (range 5–17 among loci), a highly observed (0.1667–0.6129) and an expected (0.6967–0.9448) heterozygosity was detected, indicating its usefulness in population genetics studies. Cross‐species amplification was successful in eight Characiformes species.
Isolation and characterization of swift fox tetranucleotide microsatellite loci
Authors: CULLINGHAM C. I. , SMEETON C. , WHITE B. N.
Published: November 2006

Primers have been developed for nine polymorphic tetranucleotide microsatellite loci isolated from the swift fox (Vulpes velox). These can be amplified in three multiplex reactions and all loci can be scored easily and without ambiguity. The number of alleles per locus ranged from three to 14 and the overall heterozygosities ranged from 0.54 to 1.00. All loci were in Hardy‐Weinberg equilibrium, but two loci were in linkage disequilibrium. These loci will be used to monitor endangered swift fox populations on the Canadian prairies.
Isolation and characterization of new microsatellite loci in the Pacific white shrimp Litopenaeus vannamei and cross‐species amplification in other penaeid species
Authors: FREITAS PATRÍCIA D. , JESUS CELIA M. , GALETTI PEDRO M.
Published: November 2006

The goal of the present study was to obtain valuable microsatellite markers useful in genetic approaches of the shrimp Litopenaeus vannamei, an important aquaculture species of the world. Eight loci produced suitable polymorphic patterns with allele number ranging from two to 12 and expected heterozygosity from 0.18 to 0.89. Cross‐species amplification was successfully performed in five other penaeid species (Litopenaeus schmitti, Farfantepenaeus brasiliensis, Farfantepenaeus paulensis, Xiphopenaeus kroyeri and Rimapenaeus constrictus), indicating that some these loci can be useful in studies of other related species.
Prevalence of myopia and hyperopia in a population of Polish schoolchildren
Authors: Czepita Damian , Żejmo Maria , Mojsa Artur
Published: November 2006

Purpose:  The aim of this study was to determine the prevalence of myopia and hyperopia in a population of Polish schoolchildren.

Methods:  A total of 4422 students were examined (2107 boys and 2315 girls, aged 6–18 years, mean age 11.1, S.D. 3.5). The examination included retinoscopy under cycloplegia induced with 1% tropicamide. Myopia was defined as a spherical equivalent (SE) of at least −0.5 dioptres (D), and hyperopia as a SE of at least +1.0 D. Data analysis was performed using Spearman's rank correlation coefficients and chi‐squared test; p‐values of <0.05 were considered statistically significant.

Results:  It was observed that 13.3% of Polish students in the age group ranging from 6 to 18 years were myopic while 13.1% of students were hyperopic. Furthermore, a positive correlation was found between the prevalence of myopia and age (p < 0.001) and a negative correlation between prevalence of hyperopia and age (p < 0.001). It was observed that the prevalence of myopia increases substantially between 7 and 8 years of age (p < 0.01). Moreover, it was determined that with age the average refractive error among schoolchildren becomes more myopic (p < 0.001).

Conclusions:  The occurrence, degree and progress of myopia and hyperopia in Poland is similar to that in other European countries with a predominantly Caucasian population.
Archaeoradiolites, a new genus from the Upper Aptian of the Mediterranean region and the origin of the rudist family Radiolitidae
Authors: FENERCI‐MASSE MUKERREM , MASSE JEAN‐PIERRE , ARIAS CONSUELO , VILAS LORENZO
Published: November 2006

Abstract:  Archaeoradiolites gen. nov. (Radiolitidae), mainly characterized by radially arranged branching walls structuring the outer shell layer, includes two species, Archaeoradiolites primitivus gen. et sp. nov. and Archaeoradiolites hispanicus gen. et sp. nov. (type species), the distinction of which is based on size, shell habit and development of the radially branching microstructure. Their geographical distribution is restricted to south‐east Spain and south‐west France, i.e. the Western European Tethyan margin, whereas data from the Black Sea coast of Turkey suggest a possible extension to the Eastern European Tethyan margin. Each species has a distinct biostratigraphic distribution within the Upper Aptian (mainly the Gargasian). Agriopleura is suggested to be the direct ancestor of Archaeoradiolites, which in turn is considered as the progenitor of Eoradiolites. The onset of the Radiolitidae is associated with global oceanic changes that favoured calcite as opposed to aragonite biomineralization. The acquisition of a porous shell microstructure appears, in many respects, biologically advantageous and may account for gaining a rapid (< 1 myr) ecological ability for efficient colonization and occupation of space of the family in the earlier phase of its radiation.
Cranial crest development in the Azhdarchoid pterosaur Tupuxuara, with a review of the genus and tapejarid monophyly
Authors: MARTILL DAVID M. , NAISH DARREN
Published: November 2006

Abstract:  A portion of pterosaur skull from the Romualdo Member of the Santana Formation (?Albian–?Turonian, Cretaceous) of north‐east Brazil provides new data on the morphology and ontogeny of azhdarchoid pterosaur cranial crests. The specimen consists of parts of the cranial bones posterodorsal to the nasoantorbital fenestra, including partial nasals, lacrimals, frontals and possibly the parietals. A posterodorsally directed premaxillary crest with a concave posterior border is located dorsal to the posterior border of the nasoantorbital fenestra. A well‐defined suture indicates overlapping, posterodorsally directed growth of the premaxilla over the skull roof, suggesting that the generation of the premaxillary crest is a late ontogenetic feature and thus probably related to sexual display. The systematics of Tupuxuara and its relationship to other azhdarchoids is reviewed and a cladistic analysis of the group is presented. Tupuxuara is found to be the sister‐taxon to Azhdarchidae. Tupuxuara longicristatus Kellner and Campos, 1988 is argued to be the only valid named species in this genus and Thalassodromeus Kellner and Campos, 2002 is considered a junior subjective synonym of this taxon. As originally conceived, Tapejaridae is paraphyletic: a new, more restrictive version of Tapejaridae (including Tapejara and Sinopterus dongi) might exist, but its monophyly is weakly supported. Furthermore, Tapejara was found to be paraphyletic in all trees.
The ordinary economy: tangled up in values and geography
Authors: Lee Roger
Published: November 2006

Economic geographies involve the struggle to consume, exchange and produce value through the social construction of material circuits of value capable of being sustained across space and time. They are performed and practised through a constant tension between certain material imperatives of societal reproduction, the potentially infinite, day‐to‐day variability of economic practice, social relations and conceptions of value, and the regulatory and calculable frame of ‘the economy’. Thus economic geographies are subject to more – or less – politically reflexive modes of evaluation and regulation involving multiple, simultaneously‐practised forms and relations of value. They are, therefore, part and parcel of everyday social life, always hybrid and always in a state of becoming. Three vignettes illustrate economic geographies as complex social practices with a constant tendency to incoherence. They demonstrate, thereby, the ordinariness of economies.
Geography's other histories? Geography and science in the British Association for the Advancement of Science, 1831–c.1933
Authors: Withers Charles W J , Finnegan Diarmid , Higgitt Rebekah
Published: November 2006

With reference to the history of modern geography in Britain and from assessment of the archives of the British Association for the Advancement of Science (BAAS), this paper examines the role of the BAAS in promoting geography from the Association's foundation in 1831 to the 1930s. Particular attention is paid to BAAS Section E (Geography) in the period after 1851. Geography's place is considered with respect to its funding, content and relationship with other sciences, to shifts in its focus – from exploration to what contemporaries termed ‘scientific’ geography and to the attendant decline in audiences at BAAS geography sessions – and to moments of ‘crisis’ in geography's epistemological status. In examining extant work on geography's role in the BAAS, a case is made for revision of the current historiographies of ‘modern’ British geography and questions are raised about the connections between geography and science and the writing of geography's ‘disciplinary’ and institutional history in the modern period.
LibertyandDeath: The French Revolution
Authors: Heuer Jennifer
Published: November 2006

This article explores recent developments in scholarship on the French Revolution and new strategies for teaching about it as a cauldron of both rights and violence. Historians have increasingly moved beyond the schools of Marxism, “revisionism,” and “political culture” that dominated earlier interpretations. Although individual approaches differ radically, they reveal several general trends. Scholars are rethinking the narrative of the Revolution, emphasizing unexpected turning points and previously neglected periods. Many insist that revolutionary politics and culture were always multi‐vocal, even during the most repressive moments. Historians have also turned towards apparently marginal groups and actors, attempting to assess not only how the Revolution affected them, but also how their stories affect our understanding of the dynamics of historical change. These trends are intensified, and to some extent, challenged, by attempts to situate the French Revolution within comparative history.
ADDITIONAL EVIDENCE FOR ECOLOGICAL DIFFERENCES AMONG ISOMORPHIC REPRODUCTIVE PHASES OF IRIDAEA LAMINARIOIDES (RHODOPHYTA: GIGARTINALES)1
Authors: Luxoro Carolina , Santelices Bernabe
Published: November 2006

Gametophytes are more abundant thou sporophytes in wave exposed rocky intertidal populations of Iridaea laminarioides Bory in Central Chile. In this study we experimental tested the differential effects of selected ecological factors on karyologically different life history phases. In the field, gametophytes dominated at higher elevation and during summer; tetrasporophytes were most abundant low in the intertidal and during the fall. Laboratory responses correlated with these patterns. Gametophytes exhibited greater desiccation tolerance than tetrasporophytes. Optimum growth of gametophytes occurred at higher temperatures (20°C) and longer photoperiods (16:8 h LD) than sporophytes (15°C and 12:12 h LD). Grazing preferences changed with the developmental stage of the alga, but all herbivores tested had increased preference for diploid tissues as compared to haploid. Number of spores produced with respect to total plant surface, or total rocky surface, or settlement of spores and their germination rate did not show significant differences between phases but showed great variability in space and time. Spontaneous spore release, however, was always higher in cystocarpic than in tetrasporangial thalli. Such a combination of results suggests that some real ecological differences exist between the two life history phases of I. laminarioides. Such ecological differences permit a prediction of vertical and temporal patterns of distribution for both phases. Horizontal patterns of distribution cannot be explained because the several selection factors probably interact differently in various habitats.
STIMULATION OF LIGHT‐SATURATED PHOTOSYNTHESIS IN LAMINARIA (PHAEOPHYTA) BY BLUE LIGHT1
Authors: Dring Matthew J.
Published: November 2006

The light‐saturated rate of photosynthesis in blue light was 50‐100% higher than that in red light for young sporophytes of Laminaria digitata (Huds.) Lamour., although photosynthetic rates were slightly higher in red than in blue light at low irradiances. Short exposures to low irradiances (e.g. 2 min at 20 μmol · m−2· s−1) of blue light also stimulated the subsequent photosynthesis of Laminaria sporophytes in saturating irradiances of red light but had little effect on photosynthesis in low irradiances of red light. The full stimulatory effect of short exposures to blue light was observed within 5 min of the blue treatment and persisted for at least 15 min in red light or in darkness. Thereafter, the effect began to decline, but some stimulation was still detectable 45 min after the blue treatment. The degree of stimulation was proportional to the logarithm of the photon exposure to blue light over the range 0.15‐2.4 mmol · m−2, and the effectiveness of an exposure to 0.6 mmol · m−2at different wavelengths was high at 402‐475 nm (with a peak at 460‐475 nm) but declined sharply at 475‐497 nm and was minimal at 544‐701 nm. Blue light appears, therefore, to exert a direct effect on the dark reaction of photosynthesis in brown algae, possibly by activating carbon‐fixing enzymes or by stimulating the uptake or transport of inorganic carbon in the plants.
NITROGEN LIMITATION IN ISOCHRYSIS GALBANA (HAPTOPHYCEAE). I. PHOTOSYNTHETIC ENERGY CONVERSION AND GROWTH EFFICIENCIES1
Authors: Herrig Ronny , Falkowski Paul G.
Published: November 2006

The effect of steady‐state nitrogen limitation on photo‐synthetic characteristics and growth efficiency was examined in the marine haptophyte Isochrysis galbana Green. Nitrate limited chemostats were maintained at nine dilution rates, ranging from 0.18‐0.96 d−1, under continuous irradiance levels of 175 μmole quanta·m−2·s−1, an irradiance level which saturated photosynthesis at all growth rates. Nitrogen limitation led to an overall reduction in pigmentation and a decrease in the cellular concentration of reaction centers; however, the optical absorption cross section, normalized to Chl a, increased. Moreover, Chl c/a ratios were higher in nitrogen‐limited cells: the change in Chl c/a ratios were correlated with an increase in the functional size of Photosystem II. Both light saturated photosynthetic rates normalized per cell and specific respiratory losses were positively linearly correlated with growth rate. Light saturated photosynthetic rates normalized to Chl a remained relatively insensitive to the rate of nitrogen supply. The minimum quantum requirement for gross photosynthetic oxygen evolution increased from 12.4 to 17.0 quanta/O2. At the growth irradiance, the quantum requirement increased 88%, from 19.9 to 37.5 quauta/O2 Photosynthesis/respiration ratios remained relatively constant at dilution rates greater than 35% of the maximum relative growth rate. Consequently, net growth efficiency, defined as the ratio of the specific growth rate, μ, to specific gross photosynthesis, P, also remained relatively constant over this range of growth rates averaging 85 ± 3%.