bluuebunny/crossref_metadata_2025 huggingface dataset:
Nonlinear effects of consumer density on multiple ecosystem processes
Authors: Klemmer Amanda J. , Wissinger Scott A. , Greig Hamish S. , Ostrofsky Milton L.
Published: February 2012

1. In the face of human‐induced declines in the abundance of common species, ecologists have become interested in quantifying how changes in density affect rates of biophysical processes, hence ecosystem function. We manipulated the density of a dominant detritivore (the cased caddisfly, Limnephilus externus) in subalpine ponds to measure effects on the release of detritus‐bound nutrients and energy.

2. Detritus decay rates (k, mass loss) increased threefold, and the loss of nitrogen (N) and phosphorus (P) from detrital substrates doubled across a range of historically observed caddisfly densities. Ammonium and total soluble phosphorus concentrations in the water column also increased with caddisfly density on some dates. Decay rates, nutrient release and the change in total detritivore biomass all exhibited threshold or declining responses at the highest densities.

3. We attributed these threshold responses in biophysical processes to intraspecific competition for limiting resources manifested at the population level, as density‐dependent per‐capita consumption, growth, development and case : body size in caddisflies was observed. Moreover, caddisflies increasingly grazed on algae at high densities, presumably in response to limiting detrital resources.

4. These results provide evidence that changes in population size of a common species will have nonlinear, threshold effects on the rates of biophysical processes at the ecosystem level. Given the ubiquity of negative density dependence in nature, nonlinear consumer density–ecosystem function relationships should be common across species and ecosystems.
Parenting of children with ADHD in South Korea: the role of socio‐emotional development of children with ADHD
Authors: Oh Won‐Oak , Park Eun Sook , Suk Min Hyun , Song Dong Ho , Im Yeojin
Published: February 2012

Aims and objectives.  The aim was to investigate the factors affecting the self‐esteem and social competence of children with attention deficit hyperactivity disorder.

Background.  Many studies have reported parenting variables such as parenting attitude and sense of competence have been suggested as significant determinants of socio‐emotional development of children with attention deficit hyperactivity disorder. In South Korean society, the traditional culture of Confucianism is a strong influence on parenting practices and children’s behaviour. However, there have been few studies that examined the relative significance of the parenting and other associated factors for self‐esteem and social competence in children with attention deficit hyperactivity disorder in Korea living in a strict parenting environment.

Design.  This study was designed as a cross‐sectional and descriptive survey.

Method.  The subjects were 124 pairs of mothers and their children with attention deficit hyperactivity disorder, recruited from local paediatric psychiatric clinics in South Korea. Data collection was conducted through the use of questionnaires.

Results.  Affectionate parenting attitude and co‐morbid condition of the child were the most important predictors of self‐esteem. Rejecting parenting attitude was the most important predictor of social competence.

Conclusion.  Higher levels of affectionate parenting attitude of mothers and non‐co‐morbid status of children both contributed unique variance to the overall prediction of higher self‐esteem of children. Higher levels of rejecting parenting attitude of mothers contributed unique variance to the overall prediction of lower social competence in children with attention deficit hyperactivity disorder.

Relevance to clinical practice.  Parenting attitude is the most important factor to contribute to the healthy socio‐emotional development in children with attention deficit hyperactivity disorder. Health care providers need to develop and apply a parenting skills improvement program to improve positive parenting attitudes, which will benefit self‐esteem and social competence in children with attention deficit hyperactivity disorder.
Support groups for caregivers of intellectually disabled family members: effects on physical–psychological health and social support
Authors: Wei Ying‐Shun , Chu Hsin , Chen Chiung‐Hua , Hsueh Yu‐Jung , Chang Yu‐Shiun , Chang Lu‐I , Chou Kuei‐Ru
Published: February 2012

Aims.  This study aimed to examine the effectiveness of support groups for people caring for family members with intellectual disability with the goal of improving their physical—psychological health and social support.

Background.  Little is known about how differences in the support group context influence either the nature of the social support available to caregivers of family member with intellectual disabilities or the effects on caregivers’ physical—psychological health in eastern cultures.

Design.  An experimental, preintervention postintervention control group design was used in this study.

Methods.  The experimental group received intervention consisting of eight weekly support group meetings for caregivers of people with intellectual disabilities. A total of 72 participants were recruited by permuted block randomisation and evaluated before intervention, after intervention and at four‐week follow‐up. Participants were blinded to the arrangement. Longitudinal effects were analysed by means of generalised estimating equations.

Results.  (1) Physical‐psychological health (somatic, depressive and anxiety symptoms) of participants in the experimental group was significantly improved after the intervention and four‐week follow‐up. (2) After the support group, the experimental group scored better than the control group on measures of social support (positive social interaction, emotional, informational and material social support). At four‐week follow‐up, the differences between the two groups persisted except for positive social interaction support, suggesting a continued positive effect of the support group on caregivers of family members with intellectual disabilities.

Conclusions.  The results of this study confirm the experimental hypotheses that caregivers benefit from participating in support group interventions.

Relevance to clinical practice.  The support group is an effective alternative intervention for promoting caregivers’ physical—psychological health status as well as their social support. Therefore, the support group should become a routine component of the caregiver of people with intellectual disabilities.
Management of acute coronary syndrome: achievements and goals still to pursue. Novel developments in diagnosis and treatment
Authors: Boden H. , van der Hoeven B. L. , Karalis I. , Schalij M. J. , Jukema J. W.
Published: February 2012

Abstract.  Boden H, van der Hoeven BL, Karalis I, Schalij MJ, Jukema JW (Leiden University Medical Center, Leiden, The Netherlands). Management of acute coronary syndrome: achievements and goals still to pursue. Novel developments in diagnosis and treatment (Review). J Intern Med 2012; 271: 521–536.

Acute coronary syndromes contribute a substantial part of the global disease burden. To realize a reduction in mortality and morbidity, the management of patients with these conditions involves the integration of several different approaches. Timely delivery of appropriate care is a key factor, as the beneficial effect of reperfusion is greatest when performed as soon as possible. Innovations in antithrombotic therapy have also contributed significantly to improvements in the prevention of ischaemic complications. However, with the use of such treatment, an increase in the risk of bleeding is inevitable. Therefore, the greatest challenge is now to obtain an optimal balance between the prevention of ischaemic complications and the risk of bleeding. In this regard, identification of patients at highest risk of either one is essential.
Behavioural Consequences of P‐Glycoprotein Deficiency in Mice, with Special Focus on Stress‐Related Mechanisms
Authors: Schoenfelder Y. , Hiemke C. , Schmitt U.
Published: February 2012

P‐glycoprotein (P‐gp), an efflux transporter localised in the blood–brain barrier, limits the access of multiple xenobiotics to the central nervous system. Whether it is also implemented in the transport of the endogenous glucocorticoid corticosterone is a matter of debate. The P‐gp knockout mouse model [abcb1a/b (−/−)] has been shown to differ in the functioning of the hypothalamic‐pituitary adrenal (HPA) axis. In the present study, we investigated the behaviour of abcb1a/b (−/−) and wild‐type mice with respect to stress‐related tests and the effects of corticosterone. Behavioural activities were assessed in the open field (OF) test for 4 days, and in the forced swimming test (FST) and tail suspension test (TST) under naïve and stressed conditions. The FST was also conducted after exogenous corticosterone injection (0.25 and 2.5 mg/kg). Moreover, the elevated plus maze test and the RotaRod test (RotaRod Advanced; TSE Systems, Bad Homburg, Germany) were assessed. Brain corticosterone levels were determined by an immunoassay and expression of glucocorticoid receptors by western blot analysis. Abcb1a/1b (−/−) mice showed significantly decreased brain corticosterone levels and elevated glucocorticoid receptor expression. Behavioural analysis revealed a significantly decreased activity in the OF test on the first 2 days in abcb1a/1b (−/−) mice compared to wild‐type mice, although the differences disappeared under habituation. Immobility time in the FST was significantly decreased in abcb1a/1b (−/−) mice under basal and under stressed conditions, whereas immobility in the TST was significantly elevated in these mice under all conditions. Injection of exogenous corticosterone resulted in significant reductions of immobility in the FST in abcb1a/1b (−/−) mice, whereas wild‐type mice did not respond to the same doses. There were no differences in the elevated plus maze test and RotaRod test. The results obtained in the present study demonstrate that a P‐gp deficiency has an impact on the stress‐related behaviour, possibly as a result of differences in HPA axis‐feedback regulation.
Allopregnanolone and Induction of Endogenous Opioid Inhibition of Oxytocin Responses to Immune Stress in Pregnant Rats
Authors: Brunton P. J. , Bales J. , Russell J. A.
Published: February 2012

In virgin rats, systemic administration of interleukin (IL)‐1β (i.e. to mimic infection), increases oxytocin secretion and the firing rate of oxytocin neurones in the supraoptic nucleus (SON). However, in late pregnancy, stimulated oxytocin secretion is inhibited by an endogenous opioid mechanism, preserving the expanded neurohypophysial oxytocin stores for parturition and minimising the risk of preterm labour. Central levels of the neuroactive metabolite of progesterone, allopregnanolone, increase during pregnancy and allopregnanolone acting on GABAA receptors on oxytocin neurones enhances inhibitory transmission. In the present study, we tested whether allopregnanolone induces opioid inhibition of the oxytocin system in response to IL‐1β in late pregnancy. Inhibition of 5α‐reductase (an allopregnanolone‐synthesising enzyme) with finasteride potentiated IL‐1β‐evoked oxytocin secretion in late pregnant rats, whereas allopregnanolone reduced the oxytocin response in virgin rats. IL‐1β increased the number of magnocellular neurones in the SON and paraventricular nucleus (PVN) expressing Fos (an indicator of neuronal activation) in virgin but not pregnant rats. In immunoreactive oxytocin neurones in the SON and PVN, finasteride increased IL‐1β‐induced Fos expression in pregnant rats. Conversely, allopregnanolone reduced the number of magnocellular oxytocin neurones activated by IL‐1β in virgin rats. Treatment with naloxone (an opioid antagonist) greatly enhanced the oxytocin response to IL‐1β in pregnancy, and finasteride did not enhance this effect, indicating that allopregnanolone and the endogenous opioid mechanisms do not act independently. Indeed, allopregnanolone induced opioid inhibition over oxytocin responses to IL‐1β in virgin rats. Thus, in late pregnancy, allopregnanolone induces opioid inhibition over magnocellular oxytocin neurones and hence on oxytocin secretion in response to immune challenge. This mechanism will minimise the risk of preterm labour and prevent the depletion of neurohypophysial oxytocin stores, which are required for parturition.
Epidemiological approaches to measure childhood stress
Authors: Vanaelst Barbara , De Vriendt Tineke , Huybrechts Inge , Rinaldi Sabina , De Henauw Stefaan
Published: February 2012

Vanaelst B, De Vriendt T, Huybrechts I, Rinaldi S, De Henauw S. Epidemiological approaches to measure childhood stress. Paediatric and Perinatal Epidemiology 2012; 26: 280–297.

The prevalence of childhood stress has repeatedly been shown to be high, with ‘parental separation’ and ‘being bullied at school’ as the most frequently reported stressors in the child's everyday life. This is quite alarming as children are most vulnerable to the adverse psychological and physiological health consequences of chronic stress exposure.

Despite growing research interest in this field over the last years, literature falls short in providing an overview of methods to adequately assess stress in elementary school children (6–12 years old). This review describes questionnaires and interviews, as well as laboratory measurements of cortisol in biological samples (serum, urine, saliva and hair) as stress assessment methods in children, with the emphasis on epidemiological research settings. Major characteristics, strengths and limitations of these methods are established, examples of child‐specific stressor questionnaires and interviews are provided and specific recommendations with respect to epidemiological research are formulated. In addition, hair cortisol as a potential biomarker for chronic stress (in children) is discussed more thoroughly.

This review is meant to serve as a preliminary guide for health researchers new to this research area by reflecting on theoretical and methodological aspects in childhood stress assessment.
Spatial and temporal changes in chlorophyll fluorescence images of Nicotiana benthamiana leaves following inoculation with Pseudomonas syringae pv. tabaci
Authors: Iqbal M. J. , Goodwin P. H. , Leonardos E. D. , Grodzinski B.
Published: February 2012

Inoculation of Nicotiana benthamiana leaves with virulent and avirulent strains of Pseudomonas syringae pv. tabaci resulted in increasing changes in Fv/Fm, and NPQ over time. Images of these chlorophyll a fluorescence measurements revealed different changes in different zones of the leaf. For the virulent strain, the infiltrated zone and zone directly surrounding it showed decreased Fv/Fm, and NPQ before the appearance of visible symptoms, and these decreases corresponded with increasing bacterial populations and putative tabtoxin activity. Another distinct zone of reduced Fv/Fm and NPQ extended several centimetres from the lesion to the nearest leaf margin, but only very low bacterial populations and no putative tabtoxin activity were detected in this zone. For the avirulent strain, a hypersensitive response occurred, bacterial populations remained low, and there was little detectable putative tabtoxin activity. Decreased Fv/Fm and NPQ, but not , were observed in the infiltrated zone prior to the hypersensitive response, followed by decreased values in a zone directly surrounding it. Following that, no further changes were observed. These results demonstrate that in addition to detecting pre‐symptomatic impacts of bacteria, chlorophyll a fluorescence imaging can also show that there are highly distinct regions of affected tissue that can extend considerably beyond the area of bacterial colonization. This should be considered in selecting leaf tissues for examining the effects of pathogens on plants, such as altered host gene expression or protein levels.
The impact of alcohol dependence on social brain function
Authors: Gizewski Elke R. , Müller Bernhard W. , Scherbaum Norbert , Lieb Bodo , Forsting Michael , Wiltfang Jens , Leygraf Norbert , Schiffer Boris
Published: February 2012

The impact of alcoholism (ALC) or alcohol dependence on the neural mechanisms underlying cognitive and affective empathy (i.e. the different routes to understanding other people's minds) in schizophrenic patients and non‐schizophrenic subjects is still poorly understood. We therefore aimed at determining the extent to which the ability to infer other people's mental states and underlying neural mechanisms were affected by ALC. We examined 48 men, who suffered either from ALC, schizophrenia, both disorders or none of these disorders, using functional magnetic resonance imaging while performing on a mind reading task that involves both cognitive and affective aspects of empathy. Using voxel‐based morphometry, we additionally examined whether between‐group differences in functional activity were associated with deficits in brain structural integrity. During mental state attribution, all clinical groups as compared with healthy controls exhibited poor performance as well as reduced right‐hemispheric insular function with the highest error rate and insular dysfunction seen in the schizophrenic patients without ALC. Accordingly, both behavioral performance and insular functioning revealed schizophrenia × ALC interaction effects. In addition, schizophrenic patients relative to non‐schizophrenic subjects (regardless of ALC) exhibited deficits in structural integrity and task‐related recruitment of the left ventrolateral prefrontal cortex (vlPFC). Our data suggest that ALC‐related impairment in the ability to infer other people's mental states is limited to insular dysfunction and thus deficits in affective empathy. By contrast, mentalizing in schizophrenia (regardless of ALC) may be associated with insular dysfunction as well as a combination of structural and functional deficits in the left vlPFC.
2,3,4′,5‐Tetrahydroxystilbene‐2‐O‐β‐d‐glucoside inhibits angiotensin II‐induced cardiac fibroblast proliferation via suppression of the reactive oxygen species–extracellular signal‐regulated kinase 1/2 pathway
Authors: Zhang Wei , Chen Xiang‐Fan , Huang Yan‐Juan , Chen Qing‐Qing , Bao Yuan‐Jian , Zhu Weizhong
Published: February 2012

Cardiac fibroblasts (CF) have direct and potent effects on myocardial remodelling by proliferating, differentiating and secreting extracellular matrix proteins. Prolonged activation of CF leads to cardiac fibrosis and reduces myocardial contractile function. In previous studies we showed that 2,3,4′,5‐tetrahydroxystilbene‐2‐O‐β‐d‐glucoside (TSG) exerts cardiac protection, but the mechanism involved remains unclear. The aim of the present study was to evaluate the effects of TSG on angiotensin (Ang) II‐induced CF proliferation and to explore the underlying intracellular mechanisms.

Angiotensin II (100 nmol/L)‐induced proliferation of rat neonatal fibroblasts was significantly inhibited by TSG (3–100 μmol/L), as evidenced by investigations of cell numbers and 5‐bromodeoxyuridine (BrdU) incorporation. In addition, 30 μmol/L TSG suppressed AngII‐induced expression of nuclear antigen, matrix metalloproteinase (MMP)‐2 and MMP‐9. Moreover, TSG attenuated AngII‐induced activation of mitogen‐activated protein kinase kinase (MEK) and extracellular signal‐regulated kinase (ERK) 1/2.

Angiotensin II (100 nmol/L)‐induced generation of reactive oxygen species (ROS) was reduced by 30 μmol/L TSG, as was H2O2‐induced activation of ERK1/2. However, the MEK inhibitor 50 μmol/L PD98059 did not reduce ROS generation, although it did inhibit cell proliferation.

There was a significant correlation between the inhibition of ERK1/2 activation and suppression of cell proliferation by TSG. However, there were no additive effects on either the inhibition of ERK1/2 or the suppression of cell proliferation following treatment of cells with both PD98059 and TSG.

In conclusion, the results of the present study suggest that TSG inhibits ERK1/2 activation, likely via buffering of ROS, and consequently suppresses cell proliferation.
European rabbit survival and recruitment are linked to epidemiological and environmental conditions in their exotic range
Authors: FORDHAM DAMIEN A. , SINCLAIR RON G. , PEACOCK DAVID E. , MUTZE GREG J. , KOVALISKI JOHN , CASSEY PHILLIP , CAPUCCI LORENZO , BROOK BARRY W.
Published: February 2012

The European rabbit, Oryctolagus cuniculus, is threatened within its native range, yet it is a highly successful colonizing pest species across its worldwide introduced range, causing large economic losses and widespread environmental degradation. To date, there has been no long‐term empirical evidence documenting the relative roles of climatic, epidemiological and biological factors in limiting life‐history determinants of rabbit range and abundance. Using 12 years of capture–mark–recapture data from their exotic range in Australia, we constructed candidate Cormack–Jolly–Seber models to test the influence of environmental, competition and disease conditions on rabbit survival and recruitment. Our results show that: (i) population‐level disease infection rate has the largest overall impact on rabbit survival, explaining 80% of variance in survival rates; (ii) environmental as well as epidemiological conditions constrain rabbit survival, especially for younger animals; (iii) temporal variation in rabbit kitten recruitment patterns are best described by a combination of climate, competition and disease settings (accounting for 68% of variance), while temperature alone has a strong negative influence on kitten recruitment; and (iv) recruitment responds positively to rabbit haemorrhagic disease, but negatively to myxomatosis – the former, probably being mediated through a disease driven effect on intraspecific competition for food. A strengthened understanding of climate change impacts on rabbit range and abundance can be achieved by accounting explicitly for potential synergisms between disease dynamics and climate. In this analysis, we provide the first step towards such an attempt for this important mammal species. Integrated approaches of this kind are essential for future forecasts of rabbit range and abundance, offsetting the conservation threat faced by O. cuniculus in its native range, and achieving effective management in exotic habitats.
Relative influence of habitat structure, species interactions and rainfall on the post‐fire population dynamics of ground‐dwelling vertebrates
Authors: ARTHUR ANTHONY D. , CATLING PETER C. , REID ALLAN
Published: February 2012

The long‐term impacts of wildfires on animal populations are largely unknown. We used time‐series data based on a tracking index, from coastal NSW spanning 28 years after a wildfire, to investigate the relative influence of habitat structure, species interactions and climate on post‐fire animal population dynamics. The fire had an immediate impact on habitat structure, reducing and simplifying vegetation cover, which then underwent post‐fire successional change including an increase and plateau in tree canopy cover; an increase, stabilization and then decline in shrub cover; and an increase in ground litter cover. Population changes of different animal species were influenced by different components of successional change, but there was also evidence that species interactions were important. For example, bandicoots (Isoodon obesulus and Perameles nasuta combined) increased concurrent with an increase in shrub cover then declined at a faster rate than a direct association with senescing shrub cover would suggest, while the feral cat (Felis catus) population changed with the bandicoot population, suggesting a link between these species. Potoroos (Potorous tridactylus) increased 10 years after the fire concurrent with the closing tree canopy, but there was also evidence of a negative association with feral foxes (Vulpes vulpes). Variation in rainfall did not have significant effects on the population dynamics of any species. Our results suggest that changes in habitat structure play a key role in the post‐fire dynamics of many ground‐dwelling animals and hence different fire regimes are likely to influence animal dynamics through their effects on habitat structure. However, the role of predator–prey interactions, particularly with feral predators, is less clear and further study will require manipulative experiments of predators in conjunction with fire treatments to determine whether feral predator control should be integrated with fire management to improve outcomes for some native species.
Spontaneous depolarization wave in the mouse embryo: origin and large‐scale propagation over the CNS identified with voltage‐sensitive dye imaging
Authors: Momose‐Sato Yoko , Nakamori Tomoharu , Sato Katsushige
Published: February 2012

Spontaneous embryonic movements, called embryonic motility, are produced by correlated spontaneous activity in the cranial and spinal nerves, which is driven by brainstem and spinal networks. Using optical imaging with a voltage‐sensitive dye, we have revealed previously that this correlated activity is a widely propagating wave of neural depolarization, which we termed the depolarization wave. We have observed in the chick and rat embryos that the activity spread over an extensive region of the CNS, including the spinal cord, hindbrain, cerebellum, midbrain and forebrain. One important consideration is whether a depolarization wave with similar characteristics occurs in other species, especially in different mammals. Here, we provide evidence for the existence of the depolarization wave in the mouse embryo by showing that the widely propagating wave appeared independently of the localized spontaneous activity detected previously with Ca2+ imaging. Furthermore, we mapped the origin of the depolarization wave and revealed that the wave generator moved from the rostral spinal cord to the caudal cord as development proceeded, and was later replaced with mature rhythmogenerators. The present study, together with an accompanying paper that describes pharmacological properties of the mouse depolarization wave, shows that a synchronized wave with common characteristics is expressed in different species, suggesting fundamental roles in neural development.
Australian school‐based prevention programs for alcohol and other drugs: A systematic review
Authors: TEESSON MAREE , NEWTON NICOLA C. , BARRETT EMMA L.
Published: February 2012

Issues.To reduce the occurrence and costs related to substance use and associated harms it is important to intervene early. Although a number of international school‐based prevention programs exist, the majority show minimal effects in reducing drug use and related harms. Given the emphasis on early intervention and prevention in Australia, it is timely to review the programs currently trialled in Australian schools. This paper reports the type and efficacy of Australian school‐based prevention programs for alcohol and other drugs.

Approach.Cochrane, PsychInfo and PubMed databases were searched. Additional materials were obtained from authors, websites and reference lists. Studies were selected if they described programs developed and trialled in Australia that address prevention of alcohol and other drug use in schools.

Key Findings.Eight trials of seven intervention programs were identified. The programs targeted alcohol, cannabis and tobacco and most were based on social learning principles. All were universal. Five of the seven intervention programs achieved reductions in alcohol, cannabis and tobacco use at follow up.

Conclusion.Existing school‐based prevention programs have shown to be efficacious in the Australian context. However, there are only a few programs available, and these require further evaluative research. This is critical, given that substance use is such a significant public health problem. The findings challenge the commonly held view that school‐based prevention programs are not effective.[Teesson M, Newton NC, Barrett EL. Australian school‐based prevention programs for alcohol and other drugs: A systematic review.Drug Alcohol Rev2012;31:731–736]
The Determinants and the Selection of Mexico–US Migrants
Authors: Ambrosini J. William , Peri Giovanni
Published: February 2012

Using data from the Mexican Family Life Survey (MxFLS), a panel of Mexican individuals interviewed in 2002 and 2005, we analyse the characteristics of migrants from Mexico to the US relative to non‐migrants and those who migrated and subsequently returned to Mexico. Using pre‐ and post‐migration earnings and their earnings in the US from the American Community Survey (ACS), we characterise the selection of migrants on observable and non‐observable characteristics. Merging the data with US ACS data, we can also measure the expected earnings premium of migration to the US and the earnings premium for those that returned to Mexico. We find that migrants respond to the expected earnings premium to migration, once we control for migration costs. Also, the structure of the premium across skill groups generates negative selection on average and it can explain selection on observable and unobservables. We also find that returnees are more positively selected over skills than migrants to the US. Initial poverty, old age and family ties are strong deterrents of migration to the US, once we account for the skill‐specific migration premium. We also find a strong under‐representation of college educated among migrants to the US, possibly a consequence of the fact that undocumented migration is not an attractive option for those individuals.
International Migration With Heterogeneous Agents: Theory and Evidence for Germany, 1967–2009
Authors: Brücker Herbert , Schröder Philipp J. H.
Published: February 2012

Temporary migration, though empirically relevant, is often ignored in formal models. This paper proposes a migration model with heterogeneous agents and persistent cross country income differentials that features temporary migration. In equilibrium there exists a positive relation between the stock of migrants and the income differential, while the net migration flow becomes zero. Consequently, existing empirical migration models, estimating net migration flows, instead of stocks, may be misspecified. This suspicion appears to be confirmed by our investigation of the cointegration relationships of German migration stocks and flows since 1967. We find that (i) panel‐unit root tests reject the hypothesis that migration flows and the explanatory variables are integrated of the same order, while migration stocks and the explanatory variables are all I(1) variables, and (ii) the hypothesis of cointegration cannot be rejected for the stock model.
Individual Attitudes Towards Skilled Migration: An Empirical Analysis Across Countries
Authors: Facchini Giovanni , Mayda Anna Maria
Published: February 2012

It is commonly argued that skilled immigration benefits the destination country through several channels. Yet, only a limited number of countries report having policies in place aimed at increasing the intake of skilled immigrants. Why? In this paper, we analyse the factors that affect a direct measure of individual attitudes towards skilled migration. We focus on two main channels: the labour market and the welfare state. We find that more educated natives are less likely to favour skilled immigration – consistent with the labour market channel – while richer people are more likely to do so – in accordance with the welfare state channel under the tax adjustment model. Our findings thus suggest that the labour market competition threat perceived by skilled natives in the host countries might be driving the observed cautious policies.
Skilled Worker Migration and Trade: Inequality and Welfare
Authors: Bougheas Spiros , Nelson Douglas R.
Published: February 2012

We develop a two‐sector, two‐country model where trade is driven by technological differences. Each country is populated by large number of heterogeneous workers distinguished by their level of skills. Given that one country has a technological advantage in the skilled intensive good when we allow for both trade and migration skilled workers migrate to that country. We analyse the consequences of this migration for both inequality and welfare for the source and the host country.
Migration and Trade
Authors: Egger Peter H. , von Ehrlich Maximilian , Nelson Douglas R.
Published: February 2012

Theoretical and empirical research in economics suggests that bilateral migration triggers bilateral trade through a number of channels. This paper assesses the functional form of the impact of migration on trade flows in a quasi‐experimental setting. We provide evidence that the relationship is not log‐linear. In particular, at small levels of immigration (stocks) the elasticity of trade to migration is quite high, and it declines to zero at about 4,000 immigrants. If immigration stocks exceed such a level, the evidence suggests that trade will not increase anymore. This suggests that for cross‐country network and other effects flowing from immigration to materialise at a significant level for trade, a high‐enough level of immigrant stocks is necessary. But there appears to be satiation as immigrant numbers increase.
The Law Applicable to Divorce as Test Ground for Enhanced Cooperation
Authors: Kuipers Jan‐Jaap
Published: February 2012

Enhanced cooperation was introduced in the Treaty of Amsterdam (1997). Despite a lot of academic ink being spilled, the instrument had, until recently, never been applied in practice. In June 2010, the Council reached consensus on authorising a group of Member States to pursue, in the framework of enhanced cooperation, common rules in the area of the law applicable to divorce. The present paper critically analyses this first precedent. For that purpose, the background to the policy area will be explored. Subsequently, the desirability of enhanced cooperation shall be assessed. Finally, the content of Rome III, and its effects upon Member States not participating in the initiative, will be analysed. The paper will attempt to formulate an answer to the question whether enhanced cooperation should be the new approach to harmonisation of family‐related Private International Law.
Protecting Supremacy from External Influences: A Precondition for a European Constitutional Legal Order?
Authors: Eckes Christina
Published: February 2012

The number of international law obligations that have binding force on the Union and/or its Member States is sharply increasing. This paper argues that in this light the well‐functioning of the European Union ultimately depends on the protection of the principle of supremacy from law originating outside of the EU legal order. The supremacy of EU law is essential to ensuring that Member States cannot use national rules to justify derogation from EU law.

As a matter of principle, international treaties concluded by the Member States rank at the level of ordinary national law within the European legal order and below all forms of European law (both primary and secondary). Article 351 TFEU exceptionally allows Member States to derogate from primary EU law in order to comply with obligations under anterior international agreements. It does not however allow a departure from the principle of supremacy that underlies the European legal order. In Kadi I, the Court of Justice of the European Union stated that Article 351 TFEU, while it permits derogation from primary law, may under no circumstances permit circumvention of the “very foundations” of the EU legal order. This introduces an additional condition that all acts within the sphere of EU law need to comply with a form of “super‐supreme law”. It also strengthened the principle of supremacy and gave the Court of Justice the role of the guardian of the Union's “foundations”. The Court of Justice acted on the necessity of defending the Union as a distinct legal order, retaining the autonomous interpretation of its own law, and ultimately ensuring that the Union can act as an independent actor on the international plane.
Spatial Analyses of the Urban Village Development Process in Shenzhen, China
Authors: Hao Pu , Geertman Stan , Hooimeijer Pieter , Sliuzas Richard
Published: February 2012

Urban villages are widespread in many Chinese cities, providing affordable and accessible housing for rural migrants. These urban villages develop rapidly over time to create more housing units and accommodate increasing numbers of residents. This article provides systematic analyses of urban village development in Shenzhen in the period 1999–2009. It reveals that the development of urban villages was driven by the overall planning and urban growth of the city, which resulted in significant variation in urban village development at the city scale. Three distinct but overlapping phases were observed: expansion, densification and intensification. The growth of urban villages was spatially clustered and changes over time in the distribution of growth centres suggest the possible diffusion of migrant employment out of the Special Economic Zone into two outer districts. In the recent urban regeneration process, the pattern and trend of urban village development is shown to contradict the city's urban village redevelopment programmes. This not only helps to explain the slow progress of the policy implementation, but also implies severe risks of jeopardizing the migrant housing market in certain urban sections.

Des villages urbains sont dispersés dans de nombreuses villes chinoises, procurant un habitat accessible et économique aux migrants ruraux. En essor rapide, ces implantations multiplient les logements à faible loyer et accueillent un nombre croissant d’habitants. Le développement des villages urbains de Shenzhen entre 1999 et 2009 a fait l’objet d’analyses systématiques: il a été induit par la croissance et l’aménagement d’ensemble de la ville, qui ont abouti à une importante variation de ce phénomène à l’échelle urbaine. On distingue trois phases, en partie superposées: expansion, densification et intensification. La croissance des villages urbains s’est concentrée dans l’espace, et les changements progressifs dans la répartition des pôles de croissance suggèrent la dissémination possible de l’emploi des migrants vers deux quartiers situés hors de la Zone économique spéciale. Il est montré que, dans le cadre du récent processus de régénération urbaine, le schéma et la tendance du développement de ces villages dans Shenzhen vont à l’encontre des programmes de réaménagement des villages urbains. D’une part, ces résultats permettent d’expliquer la lenteur dans la mise en œuvre des politiques publiques; d’autre part, ils suggèrent que, dans certaines zones urbaines, le marché du logement des migrants pourrait connaître une crise grave.
Demand for Dividends: The Case of UK Water Companies
Authors: Armitage Seth
Published: February 2012

Abstract:  High levels of investment in relation to cash flows, combined with high dividend payouts, have caused UK water companies persistently to borrow to meet their cash outflows. This behaviour is not adequately explained by mainstream theories of dividends. The intensive regulatory environment has meant that agency costs and information asymmetry are low, and there has been no clear tax motive for the companies’ regular dividends. It is argued that the large regular dividends are explained primarily by a demand for dividends on the part of investors, and that there are institutional or behavioural reasons for the demand.
A cost study of postoperative cell salvage in the setting of elective primary hip and knee arthroplasty
Authors: Rao Vidya K. , Dyga Robert , Bartels Christopher , Waters Jonathan H.
Published: February 2012

BACKGROUND: The increasing costs, limited supply, and clinical risks associated with allogeneic blood transfusion have prompted investigation into autologous blood management strategies, such as postoperative red blood cell (RBC) salvage. This study provides a cost comparison of transfusing washed postoperatively salvaged RBCs using an orthopedic perioperative autotransfusion device (OrthoPat, Haemonetics Corporation) versus unwashed shed blood and banked allogeneic blood.

STUDY DESIGN AND METHODS: Cell salvage data were retrospectively reviewed for a sample of 392 patients who underwent primary hip or knee arthroplasty. Mean unit costs were calculated for washed salvaged RBCs, equivalent units of unwashed shed blood, and therapeutically equivalent volumes of allogeneic RBCs.

RESULTS: No initial capital investment was required for the establishment of the postoperative cell salvage program. For patients undergoing total knee arthroplasty (TKA), the mean unit costs for washed postoperatively salvaged cells, unwashed shed blood, and allogeneic banked blood were $758.80, $474.95, and $765.49, respectively. In patients undergoing total hip arthroplasty (THA), the mean unit costs for washed postoperatively salvaged cells, unwashed shed blood, and allogeneic banked blood were $1827.41, $1167.41, and $2609.44, respectively.

CONCLUSION: This analysis suggests that transfusing washed postoperatively salvaged cells using the OrthoPat device is more costly than using unwashed shed blood in both THA and TKA. When compared to allogeneic transfusion, washed postoperatively salvaged cells carry a comparable cost in TKA, but potentially represent a significant savings in patients undergoing THA. Sensitivity analysis suggests that in the case of TKA, however, cost comparability exists within a narrow range of units collected and infused.
Inactivation and neutralization of parvovirus B19 Genotype 3
Authors: Blümel Johannes , Rinckel Lori A. , Lee Douglas C. , Roth Nathan J. , Baylis Sally A.
Published: February 2012

BACKGROUND: Parvovirus B19 (B19V) is a common contaminant of human plasma donations. Three B19V genotypes have been defined based on their DNA sequence. Reliable detection of Genotype 3 DNA has proved problematic because of unexpected sequence variability. B19V Genotype 3 is found primarily in West Africa, but was recently detected in plasma from a North American donor. The safety of plasma‐derived medicinal products, with respect to B19V, relies on exclusion of high‐titer donations, combined with virus clearance at specific manufacturing steps. Studies on inactivation of B19V are difficult to perform and inactivation of Genotype 3 has not yet been investigated.

STUDY DESIGN AND METHODS: Inactivation of B19V Genotypes 3 and 1 by pasteurization of human serum albumin and incubation at low pH was studied using a cell culture assay for infectious virus particles. Infected cells were detected by reverse transcription–polymerase chain reaction analysis of virus capsid mRNA. Neutralization of B19V Genotype 3 was investigated using human immunoglobulin preparations.

RESULTS: Genotypes 1 and 3 displayed comparable inactivation kinetics during pasteurization of albumin at 56°C, as well as by incubation at various low‐pH conditions (pH 4.2 at 37°C and pH 4.5 at 23°C, respectively) used in immunoglobulin manufacturing. Both Genotypes were readily neutralized by pooled immunoglobulin preparations of North American or European origin.

CONCLUSION: Pasteurization and low‐pH treatment were equally effective in inactivating B19V Genotypes 1 and 3. Neutralization experiments indicated that pooled immunoglobulin of North American or European origin is likely to be equally effective in treatment of disease induced by both genotypes.
V. CHILDREN NAVIGATING STORIES
Authors: Miller Peggy J. , Lin Shumin , Chen Eva Chian‐Hui , Fung Heidi
Published: February 2012

“Why didn't you reason with me nicely?” (Angu, 4,0)

“Why do you always say I do wonderful things?” (Patrick, 4,0)
Contact dermatitis: from pathomechanisms to immunotoxicology
Authors: Martin Stefan F.
Published: February 2012

Abstract:  Contact allergens are small reactive chemicals. They cause allergic contact dermatitis (ACD) by activating the innate and adaptive immune system. Contact allergens are very peculiar because of their built‐in autoadjuvanticity that allows them to trigger sterile inflammation following skin penetration. The innate inflammatory response involves the triggering of pattern recognition receptors either by direct chemical interaction with such receptors or by induction of endogenous activators. I discuss here the recent findings regarding prevalence and predisposition, the identification of innate immune and stress response mechanisms relevant for sensitization and the orchestration of the innate and adaptive immune response to contact allergens. Despite still significant gaps of knowledge, recent advances in our understanding of the immunopathogenesis of ACD can now be used for the development of causative treatment strategies and of in vitro alternatives to animal testing for the identification of contact allergens in immunotoxicology.
Study of CCN3 (NOV) and DDR1 in normal melanocytes and vitiligo skin
Authors: Ricard Anne Sophie , Pain Catherine , Daubos Alexia , Ezzedine Khaled , Lamrissi‐Garcia Isabelle , Bibeyran Alice , Guyonnet‐Dupérat Veronique , Taieb Alain , Cario‐André Muriel
Published: February 2012

Abstract:  We have hypothesised that melanocytes disappear in vitiligo because they are weakly attached to the epidermal basal membrane (melanocytorrhagy). In the epidermis, attachment of melanocytes to collagen IV is mediated through DDR1, which is under the control of CCN3. DDR1 genetic variants have been associated with vitiligo in patients of different ethnic origin. In vitro studies have shown that inhibition of CCN3 induces the detachment of melanocytes. We have studied in parallel the expression of CCN3 and DDR1 in lesional and perilesional skin of patients with vitiligo and the impact of the silencing of CCN3 and DDR1 in normal human melanocytes on their behaviour in epidermal reconstructs. Our in vivo study provides evidence of a dysregulation of the DDR1–CCN3 interaction in vitiligo skin as melanocytes remaining in perilesional skin did not express CCN3. Expression of DDR1 was decreased in lesional versus perilesional vitiligo skin in the majority of patients, and the expression of collagen IV was found decreased in all patients. Silencing of CCN3 in melanocytes induced a significant inhibition of cell adhesion to collagen IV whereas melanocytes transduced with shDDR1 still adhered well on collagen IV and did not increase melanocyte loss in epidermal reconstructs as compared with normal melanocytes. Melanocyte detachment was observed but not in all reconstructs using CCN3 silenced melanocytes. Overall, our study confirms that a downregulation of CCN3 is implicated in melanocyte adhesion in part through DDR1. In vitiligo skin, the interaction of CCN3 with other molecules, such as TGFβ and CCN2, needs to be addressed.