bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploring tree species colonization potentials using a spatially explicit simulation model: implications for four oaks under climate change
Authors: Prasad Anantha M. , Gardiner Judith D. , Iverson Louis R. , Matthews Stephen N , Peters Matthew
Published: March 2013

Climate change impacts tree species differentially by exerting unique pressures and altering their suitable habitats. We previously predicted these changes in suitable habitat for current and future climates using a species habitat model (DISTRIB) in the eastern United States. Based on the accuracy of the model, the species assemblages should eventually reflect the new quasi‐equilibrium suitable habitats (~2100) after accounting for the lag in colonization. However, it is an open question if and when these newly suitable habitats will be colonized under current fragmented landscapes and realistic migration rates. To evaluate this, we used a spatially explicit cell‐based model (SHIFT) that estimates colonization potentials under current fragmented habitats and several estimates of historical migration rates at a 1 km resolution. Computation time, which was previously the biggest constraint, was overcome by a novel application of convolution and Fast Fourier Transforms. SHIFT outputs, when intersected with future suitable habitats predicted by DISTRIB, allow assessment of colonization potential under future climates. In this article, we show how our approach can be used to screen multiple tree species for their colonization potentials under climate change. In particular, we use the DISTRIB and SHIFT models in combination to assess if the future dominant forest types in the north will really be dominated by oaks, as modelled via DISTRIB. Even under optimistic scenarios, we conclude that only a small fraction of the suitable habitats of oaks predicted by DISTRIB is likely to be occupied within 100 years, and this will be concentrated in the first 10–20 km from the current boundary. We also show how DISTRIB and SHIFT can be used to evaluate the potential for assisted migration of vulnerable tree species, and discuss the dynamics of colonization at range limits.
Women and Top Leadership Positions: Towards an Institutional Analysis
Authors: Cook Alison , Glass Christy
Published: March 2013

Women remain under‐represented in top leadership positions in work organizations, a reality that reflects a variety of barriers that create a glass ceiling effect. However, some women do attain top leadership positions, leading scholars to probe under what conditions women are promoted despite seemingly intractable and well‐documented barriers. Previous scholarship tends to posit individual‐level explanations, suggesting either that women who attain top leadership positions are exceptional or that potential women leaders lack key qualities, such as assertiveness. Much less scholarship has explored institutional‐level mechanisms that may increase women's ascension to top positions. This analysis seeks to fill this gap by testing three institutional‐level theories that may shape women's access to and tenure in top positions: the glass cliff, decision‐maker diversity, and the saviour effect. To test these theories we rely on a dataset that includes all CEO transitions in Fortune 500 companies over a 20‐year period. Contrary to the predictions of the glass cliff, we find that diversity among decision makers — not firm performance — significantly increases women's likelihood of being promoted to top leadership positions. We also find, contrary to the predictions of the saviour effect, that diversity among decision makers increases women leaders' tenure as CEOs regardless of firm performance. By identifying contextual factors that increase women's mobility, the paper makes an important contribution to the processes that shape and reproduce gender inequality in work organizations.
Mid‐Cycle Headaches and Their Relationship to Different Patterns of Premenstrual Stress Symptoms
Authors: Kiesner Jeff , Martin Vincent T.
Published: March 2013

Background

Recent research has shown that affective changes associated with the menstrual cycle may follow diverse patterns, including a classic premenstrual syndrome pattern, as well as the mirror opposite pattern, referred to as a mid‐cycle pattern.

Objective

Test for the presence of a mid‐cycle pattern of headaches, in addition to a menstrual pattern and a noncyclic pattern; test for an association between experiencing a specific pattern of headaches and a specific (previously identified) pattern of depression/anxiety; and test for mean‐level differences, across headache pattern groups, in average headache index and depression/anxiety scores (averaged across 2 menstrual cycles for each participant).

Methods

A sample of 213 female university students completed daily questionnaires regarding symptoms of headaches and depression/anxiety for 2 menstrual cycles. Hierarchical linear modeling, polynomial multiple regression, analyses of variance, and chi‐square analyses were used to test the hypotheses.

Results

Confirmed the existence of a mid‐cycle pattern of headaches (16%), in addition to a menstrual pattern (51%), and a noncyclic pattern of headaches (33%). Patterns of headaches and affective change were significantly associated (χ2 = 21.33, P = .0003; 54% correspondence), as were the average headache index and depression/anxiety scores (r = .49; P < .0001). No significant mean‐level differences were found between the headache pattern groups on the average headache index scores or depression/anxiety scores.

Conclusions

A significant number of women experience a mid‐cycle pattern of headaches during the menstrual cycle. Moreover, women often, but not always, demonstrate the same pattern of headaches and depression/anxiety symptoms.
‘The onus is on me’: primary care patient views of Medicare‐funded team care in chronic disease management in Australia
Authors: Foster Michele M. , Mitchell Geoffrey K.
Published: March 2013

Background and objective

This study investigated the views of primary care patients in receipt of Medicare‐funded team care for chronic disease management (CDM) in Australia.

Design

A qualitative study using a repeat in‐depth interview design.

Participants and setting

Twenty‐three patients (17 female), aged 32–89, were recruited over a six‐month period from two purposively selected general practices: one urban and one regional practice in Queensland, Australia.

Data collection procedure

Semi‐structured interviews were conducted with participants 6 months apart. An interview guide was used to ensure consistency of topics explored. Interviews were recorded and transcribed, and a thematic analysis was conducted.

Results

Patients in this study viewed the combined contributions of a GP and other health professionals in team care as thorough and reassuring. In this case of Medicare‐funded team care, patients also saw obligations within the structured care routine which cultivated a personal ethics of CDM. This was further influenced by how patients viewed their role in the health‐care relationship. Aside from personal obligations, Medicare funding got patients engaged in team care by providing financial incentives. Indeed, this was a defining factor in seeing allied health professionals. However, team care was also preferential due to patients' valuations of costs and benefits.

Conclusion

Patients are likely to engage with a structured team care approach to CDM if there is a sense of personal obligation and sufficient financial incentive. The level of engagement in team care is likely to be optimized if patient expectations and preferences are considered in decisions.
SATB2 is a novel marker of osteoblastic differentiation in bone and soft tissue tumours
Authors: Conner James R , Hornick Jason L
Published: March 2013

Aims

Diagnosing osteosarcoma can be challenging, as osteoid deposition is often limited in extent, and hyalinized stroma may closely mimic osteoid. SATB2 is a nuclear protein that plays a critical role in osteoblast lineage commitment. The aim of this study was to examine SATB2 expression in osteosarcomas and other bone and soft tissue tumours, to evaluate its diagnostic utility.

Methods and results

Whole sections of 215 tumours were evaluated, including 52 osteosarcomas (43 of skeletal origin; nine extraskeletal), 86 other bone tumours, and 77 other soft tissue tumours. All skeletal osteosarcomas, osteoblastomas, osteoid osteomas, and fibrous dysplasias, eight (89%) extraskeletal osteosarcomas, five (83%) giant cell tumours and three (50%) chondromyxoid fibromas showed nuclear immunoreactivity for SATB2. Staining in other bone and soft tissue tumours was predominantly limited to areas of heterologous osteoblastic differentiation. Focal weak staining was identified in one (9%) unclassified pleomorphic sarcoma and one (13%) monophasic synovial sarcoma. SATB2 was negative in all soft tissue tumours with prominent sclerotic stromal collagen.

Conclusions

SATB2 is a marker of osteoblastic differentiation in benign and malignant mesenchymal tumours. Although SATB2 is not specific for osteosarcoma, it has the potential to be a useful adjunct in some settings, particularly in the distinction between hyalinized collagen and osteoid.
Immunohistopathological features of anaplastic large‐cell lymphoma according to anaplastic lymphoma kinase expression and bone marrow involvement pattern
Authors: Park Sang Hyuk , Chi Hyun‐Sook , Cho Young‐Uk , Jang Seongsoo , Park Chan‐Jeoung
Published: March 2013

Aims

The immunohistopathological features of lesions involving the bone marrow (BM) were examined in patients with anaplastic large‐cell lymphoma (ALCL) to identify the most useful markers for the detection of BM involvement in ALCL.

Methods and results

A total of 80 patients with ALCL were enrolled, of whom 15 (18.8%) showed BM involvement. Anaplastic lymphoma kinase‐negative (ALK–) patients (n = 11) showed a nodular BM involvement pattern more frequently than ALK+ patients (n = 4; 72.7% versus 25.0%, P = 0.095). Patients with interstitial BM involvement were more frequently ALK+ than those with nodular BM involvement (50.0% versus 11.1%, P = 0.095). CD30 positivity was the strongest indicator of the presence of BM lesions, regardless of the BM involvement pattern. The application of CD30 in cases without morphological evidence of BM involvement detected subtle BM involvement by ALCL in 13.7% of cases, which were predominantly ALK+.

Conclusions

The immunohistopathological features of BM lesions in patients with ALCL differ according to ALK status and BM involvement pattern. CD30 is the most useful marker for the identification of BM lesions in ALCL patients and should be employed in all ALCL patients without exception, especially ALK+ cases.
Splenic manifestations of chronic autoimmune disorder: a report of five cases with histiocytic necrotizing change in four cases
Authors: Auerbach Aaron , Summers Thomas A , Zhang Binxue , Aguilera Nadine S
Published: March 2013

Aims

Autoimmune diseases (AD) are associated with lymphadenopathy and splenomegaly. Changes in the spleen have not been characterized completely in AD; we describe splenectomy specimens from five patients with chronic AD, highlighting the presence of necrotizing histiocytosis.

Methods and results

Of the patients (three males and two females; mean 40 years), four had systemic lupus erythematosus; one had rheumatoid arthritis. All had moderate splenomegaly (213–803 g, mean 421 g). Four cases exhibited necrosis with apoptosis and karyorrhectic debris occurring in the white pulp and minimal acute inflammation; one showed florid follicular hyperplasia. Splenic involvement ranged from focal to extensive. Plasma cells were negative for IgG4. Haematoxylin bodies were not identified. Stains for infectious organisms were negative. Immunohistochemical studies showed that lymphocytes surrounding the necrosis were a mixture of CD4+ and CD8+ T cells; CD123‐positive plasmacytoid dendritic cells were not present, and staining for kappa and lambda light chains showed no clonality. 16S rDNA PCR was performed; no amplification was seen in three of four cases tested for bacteria specific rDNA. Epstein–Barr virus‐encoded RNA (EBER) in situ hybridization studies highlighted rare positive cells in four cases.

Conclusions

Splenomegaly in AD is thought to be hyperplasic, but we present four cases showing histiocytic necrosis, a finding which should be considered part of the spectrum of AD in the spleen.
Biodiversity patterns in a macroinvertebrate community of a temporary pond network
Authors: Florencio Margarita , Díaz‐Paniagua Carmen , Gómez‐Rodríguez Carola , Serrano Laura
Published: March 2013

Macroinvertebrate assemblages of temporary ponds are ideal model systems to explore biodiversity patterns and metacommunity ecology. In addition, the study of the environmental variables driving such biodiversity patterns is essential in establishing proper guidelines for the conservation of the singular fauna of temporary ponds, especially since such ponds are vulnerable systems.

We analysed the macroinvertebrate assemblages and environmental characteristics of 80 ponds spread across the Doñana National Park, SW Spain to (i) analyse macroinvertebrate β‐diversity and metacommunity structure; and (ii) discern the main environmental and spatial drivers of these patterns.

The pond network was highly heterogeneous as temporary ponds were highly variable. Macroinvertebrate β‐diversity partitioning showed that species replacement made the greatest contribution to total β‐diversity while the contribution of nestedness was small. The macroinvertebrate community structure and β‐diversity were similarly driven by: electrical conductivity (and co‐variables alkalinity, pH, and ion concentrations), plant richness (and the co‐variable pond surface area), maximum depth, marsh, and coastal proximity as well as two spatial descriptors extracted from Moran's eigenvector maps. The spatial descriptors indicated that large interpond distances were involved, suggesting that species dispersal limitations only take place over long distances in the area.

Those taxa that departed from the general nested pattern, termed idiosyncratic, significantly contributed to the maintenance of high pond network diversity through the species replacement and occurred within particular environmental conditions in the pond network.

These results reveal that environmental heterogeneity and connectivity are key factors in the preservation of high macroinvertebrate diversity in nested pond networks with high numbers of idiosyncratic species.
Automated quantitation of fetomaternal hemorrhage by flow cytometry for HbF‐containing fetal red blood cells using probability state modeling
Authors: Wong L. , Hunsberger B. C. , Bruce Bagwell C. , Davis B. H.
Published: March 2013

Background

Flow cytometric methods (FCMs) are the contemporary standard for fetal red blood cell (RBC) quantitation and fetomaternal hemorrhage (FMH) detection. FCM provides greater sensitivity and repeatability relative to manual microscopic Kleihauer–Betke methods. FCM assays are not totally objective, employing subjective manual gating of fetal RBCs with measureable interobserver imprecision. We investigated Probability State Modeling to automate analysis of fetal RBCs using an assay for hemoglobin F (HbF)–containing RBCs.

Methods

Two hundred human bloods were processed using the FMH QuikQuant™ assay (Trillium Diagnostics, Brewer, ME, USA). A Probability State Model (PSM) was designed to enumerate fetal RBCs by selecting the three RBCs subpopulation based on differences in intensity levels of several parameters. The GemStone™ program uses a PSM that requires no operator intervention. Routine manual analysis by experienced users was performed, along with replicate analyses for both methods.

Results

The PSM by GemStone™ correlates strongly with the expert manual analysis, r2 = 0.9986. The mean absolute difference of the FMH results between GemStone™ and manual ‘expert’ analysis was 0.04% with no intermethod bias detected. Manual gating demonstrated coefficient of variations (CVs) of 10.6% for intra‐analyst replicates and 22.6% for interanalyst imprecision. The interanalyst agreement in GemStone™ is a perfect correlation, r2 = 1.00, and no imprecision with a 0.00% CV.

Conclusion

Automated PSM analysis of fetal RBCs strongly correlates with expert traditional manual analysis. PSM enumerates fetal RBCs accurately with significantly greater objectivity and lower imprecision than the traditional manual gating method. Thus, PSM provides a means to markedly improve interlaboratory variance with FMH assays based upon subjective gating strategies.
Cerebral CT Perfusion in Patients with Perimesencephalic and Those with Aneurysmal Subarachnoid Hemorrhage
Authors: Cremers Charlotte H. P. , van der Schaaf Irene C. , Dankbaar Jan Willem , Velthuis Birgitta K. , Rinkel Gabriel J. E.
Published: March 2013

Background

The cause of perimesencephalic hemorrhage is unknown, but a venous source is suggested. If perimesencephalic hemorrhage is of venous origin, less elevation of the intracranial pressure and less perfusion deficits are expected than after aneurysmal subarachnoid hemorrhage.

Aims

We compared perfusion in the acute stage after perimesencephalic hemorrhage and aneurysmal subarachnoid hemorrhage.

Methods

We included 45 perimesencephalic hemorrhage patients and 45 aneurysmal subarachnoid hemorrhage patients, who were matched on clinical condition at admission and underwent computerized tomographic scanning <72 h after subarachnoid hemorrhage. Cerebral blood flow was assessed in 12 predefined regions of interest. Differences in cerebral blood flow values with corresponding 95% confidence intervals were calculated. Sub-group analyses were performed stratified on comparable amounts of blood and location of blood (posterior circulation aneurysms and additionally in infratentorial and supratentorial aneurysms).

Results

Cerebral blood flow was higher in perimesencephalic hemorrhage patients (mean: 63·8) than in aneurysmal subarachnoid hemorrhage patients (mean: 55·9; difference of means: −7·9 [95% confidence interval: −10·7 to −5·2]) and also in the sub-group with comparable amounts of blood (mean cerebral blood flow: 56·4; difference of means: −7·4 [95% confidence interval: −10·4 to −4·3]). Cerebral blood flow was comparable with perimesencephalic hemorrhage patients for the sub-group with posterior circulation aneurysms (difference of means: −0·7 [95% confidence interval: −5·2 to 3·8]); however, differences diverged after stratifying posterior circulation aneurysms into supratentorial (difference of means −3·9 [95% confidence interval: −9·3 to 1·4]) and infratentorial aneurysms (difference of means 3·0 [95% confidence interval: −2·8 to 8·8]).

Conclusion

Perimesencephalic hemorrhage patients have a higher cerebral blood flow than aneurysmal subarachnoid hemorrhage patients. The findings of this study further support a venous origin of bleeding in perimesencephalic hemorrhage patients. Future studies should further elaborate on cerebral blood flow in posterior circulation aneurysms.
Approaches to Economic Evaluations of Stroke Rehabilitation
Authors: Craig Louise E , Wu Olivia , Bernhardt Julie , Langhorne Peter
Published: March 2013

Many stroke rehabilitation services and interventions are complex in that they involve a number of components, interactions, and outcomes. Much of the onus of stroke care lies with rehabilitation services and because stroke rehabilitation is highly resource intensive, it is important for policy makers to consider the potential trade-offs between all relevant costs and benefits. The primary aim of this systematic review was to assess the methods used to conduct economic evaluations of stroke rehabilitation. Studies that compared two or more alternative stroke rehabilitation interventions or services with the costs and outcomes being examined for each alternative were included. EMBASE, MEDLINE In-Process, and National Health Service's Economic Evaluation Database were searched using search strategies. The methodological quality of the included studies was appraised using a checklist for the conduct and reporting of economic evaluations. Twenty-one studies met the selection criteria. The economic evaluations in the majority of these studies were inadequate based on their ability to identify, measure, and value all resources and benefits pertinent to the complexity of stroke rehabilitation. This study highlights that complex interventions such as stroke rehabilitation have widespread effects, which may not be represented by the changes on a single outcome. This study recommends the adoption of a wider cost and benefit perspective in the economic evaluations of complex interventions. It supports a move away from conventional economic evaluation and decision making, based purely on cost-effectiveness, toward multicriteria decision analysis frameworks for complex interventions, where a broader range of criteria may be assessed by policy makers.
White Matter Disease and an Incomplete Circle of Willis
Authors: Ryan Daniel James , Byrne Susan , Dunne Ruth , Harmon Mark , Harbison Joseph
Published: March 2013

Introduction

White matter disease occurs as a consequence of small vessel disease; however, hypoperfusion may also play a role. We investigated whether patients with less cerebral vessel anastomosis may develop more white matter disease.

Methods

Magnetic resonance imaging (1.5t) with intracranial magnetic resonance angiography data was collected on a convenience sample between July 2008 and January 2009. All patients were independently assessed for circle of Willis variants by two researchers and categorized into two groups: those with a complete circle of Willis and those with an incomplete circle of Willis (absent vessels). The complete group was sub-divided into a classical group (entirely normal circle of Willis) and a hypoplastic group (hypoplasia but no absent vessels). White matter disease assessment was conducted for these groups, by two researchers blind to magnetic resonance angiography findings, on all patients over 50 years old.

Results

The circle of Willis was characterized in 163 patients, while 90 (>50 years) underwent white matter disease assessment. The kappa inter-rater reliability between both circle of Willis assessors and between both white matter disease assessors was 0·57 and 0·63, respectively. The prevalence of circle of Willis variants strongly correlated with the seminal paper by Riggs and Rupp. Independent of age and gender, those with an incomplete circle of Willis ( n = 68) exhibited 58% more white matter disease than those with a complete circle of Willis ( n = 22) (white matter disease score 6·52 vs. 4·11, respectively, P = 0·03). Patients with absent anterior vessels exhibited more frontal white matter disease than those with intact anterior vessels (3·7 vs. 1·72, P < 0·001). Patients with absent posterior vessels exhibited more occipital white matter disease than those with intact posterior vessels (2·52 vs. 1·34, P = 0·014).

Conclusion

These data suggest that congenital absence of anastomotic capacity correlates with incident white matter disease, thus alluding to a hypoperfusion mechanism in the development of white matter disease.
Effects of Policy Changes on Thai Migration to Iceland
Authors: Bissat Johanna Gisladottir
Published: March 2013

In this study, I use ethnographic, survey and Icelandic government data to examine the nexus of recent migration policy changes in Iceland and the increased use of marriage as a migration strategy. In the early 1980s, Thai women began coming to Iceland to either marry Icelandic men or “try out” a potential relationship with an Icelander before marriage. During that time, Iceland approved work permits for foreigners regardless of country of origin, allowing many Thais to immigrate independent of marriage. By 2006, however, Iceland's membership in the European Economic Area was making it almost impossible for Thais and other non‐European migrants to secure a work permit. There has been an increase in marriage‐based migrations among non‐European migrants to Iceland compared to all other types of legal migration since 2006. Iceland's policy changes may have stemmed the flow of non‐European labourers, but may also have opened the door to increased fraudulent marriages and abuse of foreign women by Icelandic husbands. These policy changes have only occurred in the past 5–7 years, and it remains for future research to investigate adjustments made by both Icelanders and Thais in response to the newest laws.
Migration, Policy, and Anthropology
Authors: Haines David
Published: March 2013

In reviewing the articles in this special issue on the migration/policy/anthropology nexus, my comments will be in three parts: first, presenting a rough framework by which we might look at public policy in a way that bridges the academic and the practical; second, considering the actual cases presented in this special issue; and third, considering more broadly what the anthropological contribution might be to this complex and often acrimonious issue of migration policy. Throughout, the attempt is to search for a way of looking at migration policy that balances the inevitable academic critiques of public policy with a recognition of what public policy can and inevitably must be as a tool of societal discussion, planning, and progress.
Trends in nursing research in France: a cross‐sectional analysis
Authors: Dupin C.M. , Chami K. , Petit dit Dariel O. , Debout C. , Rothan‐Tondeur M.
Published: March 2013

Aim

To examine the engagement of French registered nurses with the Ministry of Health's initiative to spur scientific inquiry in the community.

Background

French nursing research has suffered from a lack of dedicated funding. Positive signs of change have recently appeared, with the launch of the first national public funding programme dedicated to nursing research. This initiative, begun in 2010, was launched by the French Ministry of Health. Through this initiative, 149 registered nurses, serving as principal investigators, and their teams submitted research proposals between 2010 and 2011. The administrative guidelines of the funding programme are clearly oriented towards producing quantitative and exogenous nursing research.

Method

A cross‐sectional analysis of 149 nursing research projects submitted during the first and second years of a French national funding programme for hospital‐based nursing research was conducted. Research proposals were included in the analysis whether they received funding or not. Data collection took place in 2011. The categories used in the analysis were the following: (1) the socio‐demographic data on the registered nurse principal investigators, (2) the research teams and (3) the research proposals (methodologies, bibliography, focus of the research, output, the status of the research proposals).

Results

This study highlights the presence of methodological homogeneity among the research proposals submitted for funding. Clear tendencies were towards interventional and quantitative studies and those with an exogenous factor research objective. Between 2010 and 2011, 25 projects were funded out of 149 submitted. They were mostly quantitative and/or focused on the exogenous factors in patient care.

Conclusion

The socio‐political context of a funding programme designed to encourage nursing research has had an implicit influence on the type of research to which French nurses have committed themselves to and the scientific positions with which these nurse researchers align themselves.
Why Do People Stigmatise the Poor at a Time of Rapidly Increasing Inequality, and What Can Be Done About It?
Authors: Taylor‐Gooby Peter
Published: March 2013

This paper starts out from a puzzle. During the past thirty years, incomes have grown more unequal, a small group at the top has captured a much greater share of resources and poverty has increased. Despite this, most people are markedly less likely to want government to redistribute income or tackle poverty and are less sympathetic towards those without jobs. The greater insecurity of many people's lives in the current crisis renders the issue more perplexing. This paper describes trends in inequality, poverty and unemployment; presents new data on attitudes, media discussion and political platforms; discusses theoretical approaches from social psychologists, political scientists, sociologists and other commentators; and considers how a more generous welfare state might be pursued.
Whatever Happened to Greece?
Authors: Fouskas Vassilis K.
Published: March 2013

The sovereign debt crisis in Greece and other periphery countries is a yardstick for the viability of the European project: if Greece defaults and exits the Euro‐zone, then the entire European architecture will be questioned. This article examines the origins of the Greek debt crisis and argues that the key sources of the debt are the economic and political factions that have dominated Greek politics since the fall of the Colonels in summer 1974 amidst the Cyprus calamity. These factions (political parties, comprador economic interests etc.), whose policy actions and preferences are amalgamated with the interests of Euro‐Atlantic elites, are now being severely undermined, both politically and economically, as the prosperity of the Greek middle classes is eroded following two years of harsh austerity measures imposed on the Greek ruling factions by those Euro‐Atlantic elites. Furthermore, this article outlines ways out of the Greek debt crisis, putting into test some reasonable policy proposals that are being widely discussed in Greece and abroad.
The Second Time as Tragedy? Welfare Reform under Thatcher and the Coalition
Authors: Mabbett Deborah
Published: March 2013

The welfare reforms of the Coalition government are marked by the legacy of Thatcherism. Social security reforms in the 1980s reshaped the system towards reliance on means‐tested benefits. Negative policy feedback created by the opacity and perverse effects of means‐testing has made these benefits an easy target for the Coalition, at least so far as working age people are concerned. Different policy feedbacks affect policy towards old age pensions. The government is locked into promoting private pensions, and is extending this commitment with automatic enrolment. To make private pensions pay, it has to reverse the slide to means‐testing. The implication is that the pronounced bias against the working poor and in favour of older people in Coalition policy is not simply a matter of electoral preferences: rather, it reflects the political effects of previous policy decisions.
Beyond the Social Market: Rethinking Capitalism and Public Policy
Authors: Jacobs Michael
Published: March 2013

Despite its worthy motives, social market philosophy provides neither a useful analytical framework for understanding modern capitalism, nor the policy tools to address our present economic and social predicament. The concept of ‘market failure’, with its underlying assumption of market equilibrium, does not capture the systemically adverse outcomes of collective market forces. A more sophisticated understanding of capitalist economies, and the societies in which they exist, would recognise that the market economy is a dynamic but not self‐regulating system. It is embedded in, and impacts on, four other economies – of the natural environment, of family and care, of voluntary association, and of the public sector – which operate under different motivations and allocative principles. The role of government is central, to balance the values created by different kinds of institutions and to constrain the dynamic impacts of market forces. A number of policy conclusions are offered arising from this framework.
Rational bubbles and expectation‐driven fluctuations
Authors: Bosi Stefano , Seegmuller Thomas
Published: March 2013

In this paper, we propose a unified approach to understand the fluctuations of a rational bubble. We focus on an overlapping generations exchange economy where each household makes a portfolio choice between money, held because of a liquidity constraint, and another asset with no fundamental value. We show the existence of equilibria where the second asset takes a positive value as a pure rational bubble. There may exist endogenous cycles and bubble fluctuations driven by the volatility of agents' expectations. An expansionary monetary policy can shelter the economy from these endogenous fluctuations, but this positive effect is counterbalanced by a welfare loss according to the Friedman critique: there is a trade‐off between the stability and the stationary welfare target. Eventually, we consider a temporary bubble on real balances as an alternative source of self‐fulfilling cycles.
On the timing and optimality of capital controls: Public expenditures, debt dynamics and welfare
Authors: Boucekkine Raouf , Pommeret Aude , Prieur Fabien
Published: March 2013

This paper solves a second‐best problem where a government has to choose whether to tax financial inflows (capital controls) or not, and when. A multi‐stage optimal control technique is used to this end. First, it is shown that it is optimal to switch in finite time from capital controls to full financial liberalization whenever a measure of total wealth is above a certain threshold. In particular, a too large initial debt makes financial liberalization sub‐optimal. Second, capital controls should be used countercyclically. Third, financial liberalization is not unaffordable only for poor countries, even wealthy countries might find it optimal to implement capital controls if they aim to keep a large amount of public expenditure.
A remark on the set of arbitrage‐free prices in a multi‐period model
Authors: Cornet Bernard , Ranjan Abhishek
Published: March 2013

We study the convexity property of the set of arbitrage‐free prices of a multi‐period financial structure . The set of arbitrage‐free prices is shown to be a convex cone under conditions on the financial structure that hold in particular for short‐lived assets. Furthermore, we provide examples of equivalent financial structures and such that is a convex cone, but is neither convex nor a cone.
Destabilizing balanced‐budget consumption taxes in multi‐sector economies
Authors: Nishimura Kazuo , Nourry Carine , Seegmuller Thomas , Venditti Alain
Published: March 2013

We examine the impact of balanced‐budget consumption taxes on the existence of expectations‐driven business cycles in two‐sector economies with infinitely lived households. We prove that, whatever the relative capital intensity difference across sectors, aggregate instability can occur if the consumption tax rate is not too low. Moreover, we show through a numerical exercise based on empirically plausible tax rates that endogenous business‐cycle fluctuations may be a source of instability for all OECD countries, including the US.
Small improving coalitions and small group effectiveness
Authors: Wooders Myrna
Published: March 2013

Within the context of transferable utility (TU) games derived from cooperative pregames, this paper demonstrates the equivalence of two properties:

Small group effectiveness – that all, or almost all gains to collective activities can be realized by cooperation only within relatively small groups of players.

Small group effectiveness of improvement – that all or almost all improvement can be realized by relatively small groupsof players.

With many players, small group effectiveness ensures that diverse economies, including those with local public goods, clubs, indivisibilities and non‐monotonicities are competitive; there exists price‐taking economic equilibrium and the outcomes in the core and of price‐taking equilibrium are equivalent and have the equal‐treatment property. The results of this paper thus show that small group effectiveness for improvement provides an alternative characterization of the conditions underlying perfect competition.
Posterior Circulation Stroke is Associated with Prolonged Door-to-Needle Time
Authors: Sarraj Amrou , Medrek Sarah , Albright Karen , Martin-Schild Sheryl , Bibars Wafi , Vahidy Farhaan , Grotta James C. , Savitz Sean I.
Published: March 2013

Background

Lack of recognition of early symptoms of acute posterior circulation ischaemic stroke might delay timely diagnosis and treatment with tissue plasminogen activator.

Aims and hypothesis

We hypothesized that patients with posterior circulation stroke receive delayed thrombolytic treatment in comparison to anterior circulation stroke. We investigated the differences in times to evaluation or treatment between patients with anterior circulation ischaemic stroke and posterior circulation stroke in our aim to understand the barriers that might have caused these delays.

Methods

A cross-sectional study was conducted using consecutive patients presenting to our tertiary academic centre with acute ischaemic stroke who were treated with intravenous tissue plasminogen activator within 4·5 h from symptom onset. We compared demographics, stroke severity, symptoms and signs, and time intervals among onset, emergency department arrival, emergency department physician evaluation, neurologist evaluation, brain imaging, and tissue plasminogen activator treatment in patients with anterior circulation stroke and posterior circulation stroke.

Results

Among 252 patients treated with intravenous tissue plasminogen activator, 12% had posterior circulation stroke. Patients with posterior circulation stroke had significantly lower median baseline the National Institutes of Health and Stroke Scale (NIHSS) score ( P = 0·01), higher frequency of nausea ( P < 0·01), vomiting ( P < 0·01), dizziness ( P < 0·01), and lower frequency of aphasia ( P = 0·002) or neglect ( P = 0·048). The emergency department physician evaluation-to-neurologist evaluation and door-to-needle intervals were significantly longer for posterior circulation stroke patients compared with anterior circulation stroke patients. The neurologist-to-needle time, however, was similar in the two groups. The presence of nausea and vomiting was associated with a longer time from emergency department evaluation to neurology evaluation and had a significant association with delayed treatment.

Conclusions

Posterior circulation stroke patients had a delay in neurology evaluation after initial emergency department evaluation and a delay in intravenous tissue plasminogen activator administration compared with anterior circulation stroke patients. There may be difficulties in rapidly recognizing the symptoms of posterior circulation stroke, in contrast to anterior circulation stroke, in the emergency department.
Diffusion Kinetics of Indium in TiO2 (Rutile)
Authors: Atanacio Armand J. , Bak Tadeusz , Nowotny Janusz , Prince Kathryn E.
Published: March 2013

This work determines the self‐diffusion coefficients of indium in TiO2 single crystal (rutile). Diffusion concentration profiles were imposed by deposition of a thin surface layer of InCl3 on the TiO2 single crystal and subsequent annealing in the temperature range 1073–1573 K. The diffusion‐induced concentration profiles of indium as a function of depth were determined using secondary ion mass spectrometry (SIMS). These diffusion profiles were used to calculate the self‐diffusion coefficients of indium in the polycrystalline In2TiO5 surface layer and the TiO2 single crystal. The temperature dependence of the respective diffusion coefficients, in the range 1073–1573 K, can be expressed by the following formulas: urn:x-wiley:00027820:media:jace12244:jace12244-math-0001and urn:x-wiley:00027820:media:jace12244:jace12244-math-0002The obtained activation energy for bulk diffusion of indium in rutile (316 kJ/mol) is similar to that of zirconium in rutile (325 kJ/mol). The determined diffusion data can be used in selection of optimal processing conditions for TiO2–In2O3 solid solutions.
Surface Modification in Polycrystalline Y2O3 Under High‐Pressure/High‐Temperature Processing Conditions
Authors: Al‐Sharab Jafar F. , Deutsch Stuart , Nordahl Christopher S. , Tse Stephen D. , Kear Bernard H.
Published: March 2013

A pressure‐induced phase transformation is used to refine the grain size of polycrystalline Y2O3, by a factor of 3000. A surface modification effect accompanies the observed grain refinement, which becomes more apparent with increasing holding time under high pressure. The surface‐modified layer exhibits lower hardness and lower oxygen content relative to the underlying material. Moreover, it possesses columnar‐grained structure with cubic symmetry, whereas the interior has a monoclinic structure.
Evolution of Mineralogical Phases by27Aland29SiNMRinMK‐Ca(OH)2System Cured at 60°C
Authors: Frías Moisés , Martínez‐Ramírez Sagrario , Blasco Teresa , Rodríguez María Frías
Published: March 2013

The evolution of the metastable phases in metakaolin/Ca(OH)2systems cured at high temperatures, remains mostly unknown, newer techniques may now help to establish both the kinetic mechanism of the pozzolanic reaction and the thermodynamic stability of the main hydrated hexagonal phases: Stratlingite (C2ASH8) and tetra calcium aluminate hydrate (C4AH13). For this reason this work examines the kinetics of the pozzolanic reaction in theMK/Ca(OH)2system over 123 d at 60°C using nuclear magnetic resonance spectroscopy (27Aland29SiNMR). The results obtained by27Aland29SiNMRshow that during the first 30 h, the metastable phasesC2ASH8andC4AH13, coexist with the cubic phase (C3ASH6) obtained directly from the pozzolanic reaction. The gel C–S–H is clearly identified after 21 h of reaction, whereas at shorter times the C–S–H bands overlap those with the unreacted metakaolin ones. After 123 d of pozzolanic reaction, the first signs of the cubic phase are detected, a consequence of the conversion reaction of the metastable phases, and a phenomenon not previously identified.
Effect of Polyvinylpyrrolidone Additions on the Rheology of Aqueous, Highly Loaded Alumina Suspensions
Authors: Acosta Manuel , Wiesner Valerie L. , Martinez Carlos J. , Trice Rodney W. , Youngblood Jeffrey P.
Published: March 2013

The control of the rheological behavior of highly loaded ceramic/polymer suspensions affords the development of near‐net shape forming techniques. In this study, suspensions containing sub‐micrometer diameter alumina (up to 56 vol%) were fabricated using an anionic dispersant (≈4 vol%) and water‐soluble polyvinylpyrrolidone (PVP). The amount and ratio of molecular weights of PVP in the suspension were varied to influence flow behavior. The final pH of the system, ≈9.5, was higher than the isoelectric point (IEP) of alumina implying that the alumina powder possesses a negative surface charge. In the case of alumina at this pH, PVP does not adsorb onto the surface of the powder. The flow behavior of the PVP‐containing suspensions displayed yield‐pseudoplastic characteristics that closely agreed with the Herschel–Bulkley fluid model. The addition of PVP significantly changed the rheology of the system, increasing the shear yield stress and altering flow behavior. Interparticle interaction approximations of the suspensions were modeled to correlate with experimental observations.
Electric Field Assisted Sintering of Cubic Zirconia at 390°C
Authors: Downs John A. , Sglavo Vincenzo M.
Published: March 2013

Using the flash sintering technique, cubic yttria‐stabilized zirconia is shown to sinter at 390°C, more than 1000°C below nominal sintering temperatures, by using a DC electric field of 2250 V/cm. Furthermore, flash sintering experiments performed with electric fields between 60 and 2250 V/cm were used to show that the relationship of the temperature at the onset of flash sintering (TOnset) and the applied field (E) follows the power relationship TOnset (K) = 2440 E−1/5.85(V/cm). Using this relationship, and considering the sintering of the sample in the absence of an electric field, the critical electric field to enter the flash sintering regime is shown to be 24.5 V/cm. For electric fields between this critical electric field and 2250 V/cm, the onset of flash sintering occurs in the same range of critical volumetric power dissipation, between 1 and 10 mW/mm3, suggesting this is a material property. Despite the volumetric power dissipation being the critical value for the onset of flash sintering behavior, the current density achieved during sintering appears to be more critical for densification rather than maximizing power dissipation.
Crystallization Behaviors of PbSe Quantum Dots in Silicate Glasses
Authors: Ma De‐Wei , Cheng Cheng
Published: March 2013

This study, composed of three parts, aims at studying the crystallization behaviors of PbSe quantum dots (QDs) in silicate host glasses. Firstly, due to the importance of the choice of base glass for the QDs' crystallization, the selection of base glass compositions, the glass fragility, and glass formation ability (GFA) are discussed in details, and the results show that the selected glass compositions have an intermediate fragility and accordingly an intermediate glass transition temperature range among a wide variety of inorganic glass systems together with a good GFA/glass stability (GS). Thus, this base glass is suitable as the host glass in which PbSe QDs crystallize. Secondly, the experimental results on PbSe QDs' crystallizations are presented, and the results show that PbSe QDs can precipitate from silicate glasses favorably with no other chemical compounds precipitation, and the optimized temperature for PbSe QDs crystallization is 600°C. Lastly, the classical nucleation theory is used to analyze the PbSe QD crystallization behaviors in host glasses. The steady‐state nucleation rates and the growth rates of PbSe QDs as well as the time–temperature transformation (TTT) curves are calculated. The results indicate that the free surface energy between the PbSe nuclei and the host glass has great influence on the nucleation rates of PbSe QDs, while it has less effect on the growth rates of PbSe QDs; the crystallization behaviors of PbSe QDs with different volume fractions can be described well by the TTT curves while keeping the dimensionless empirical constant, α, unchanged for one certain curve.
Spark Plasma Sintering of SuperhardB4C–ZrB2Ceramics by Carbide Boronizing
Authors: Zou Ji , Huang Shui‐Gen , Vanmeensel Kim , Zhang Guo‐Jun , Vleugels Jef , Van der Biest Omer
Published: March 2013

A carbide boronizing method was first developed to produce dense boron carbide‐ zirconium diboride (“B4C”–ZrB2) composites from zirconium carbide (ZrC) and amorphous boron powders (B) by Spark Plasma Sintering at 1800°C–2000°C. The stoichiometry of “B4C” could be tailored by changing initial boron content, which also has an influence on the processing. The self‐propagating high‐temperature synthesis could be ignited by 1 molZrCand 6 molBat around 1240°C, whereas it was suppressed at a level of 10 molB.B8C–ZrB2ceramics sintered at 1800°C with 1 moleZrCand 10 mole B exhibited super high hardness (40.36 GPa at 2.94 N and 33.4 GPa at 9.8 N). The primary reason for the unusual high hardness ofB8C–ZrB2ceramics was considered to be the formation of nano‐sizedZrB2grains.
Electro‐Sintering of Yttria‐Stabilized Cubic Zirconia
Authors: Kim Seung‐Wan , Kang Suk‐Joong L. , Chen I‐Wei
Published: March 2013

Electro‐sintering, i.e., electrically enhanced densification without the assistance of Joule heating, has been observed in 70% dense 8 mol% Y2O3‐stabilized ZrO2 ceramics at temperatures well below those for conventional sintering. Remarkably, full density can be obtained without grain growth under a wide range of conditions, including those standard for solid oxide fuel cell (SOFS) and solid oxide electrolysis cell (SOEC), such as 840°C with 0.15 A/cm2. Microstructure evidence and scaling analysis suggest that electro‐sintering is aided by electro‐migration of pores, made possible by surface flow of cations across the pore meeting lattice/grain‐boundary counter flow of O2−. This allows pore removal from the anode/air interface and densification at unprecedentedly low temperatures. Shrinkage cracking caused by electro‐sintering of residual pores is envisioned as a potential damage mechanism in SOFC/SOEC 8YSZ membranes.