bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimating the timing of early eukaryotic diversification with multigene molecular clocks
Authors: Parfrey Laura Wegener , Lahr Daniel J. G. , Knoll Andrew H. , Katz Laura A.
Published: August 2011

Although macroscopic plants, animals, and fungi are the most familiar eukaryotes, the bulk of eukaryotic diversity is microbial. Elucidating the timing of diversification among the more than 70 lineages is key to understanding the evolution of eukaryotes. Here, we use taxon-rich multigene data combined with diverse fossils and a relaxed molecular clock framework to estimate the timing of the last common ancestor of extant eukaryotes and the divergence of major clades. Overall, these analyses suggest that the last common ancestor lived between 1866 and 1679 Ma, consistent with the earliest microfossils interpreted with confidence as eukaryotic. During this interval, the Earth's surface differed markedly from today; for example, the oceans were incompletely ventilated, with ferruginous and, after about 1800 Ma, sulfidic water masses commonly lying beneath moderately oxygenated surface waters. Our time estimates also indicate that the major clades of eukaryotes diverged before 1000 Ma, with most or all probably diverging before 1200 Ma. Fossils, however, suggest that diversity within major extant clades expanded later, beginning about 800 Ma, when the oceans began their transition to a more modern chemical state. In combination, paleontological and molecular approaches indicate that long stems preceded diversification in the major eukaryotic lineages.
Modelling the ecological–functional diversification of marine Metazoa on geological time scales
Authors: Bush Andrew M. , Novack-Gottshall Philip M.
Published: August 2011

The ecological traits and functional capabilities of marine animals have changed significantly since their origin in the late Precambrian. These changes can be analysed quantitatively using multi-dimensional parameter spaces in which the ecological lifestyles of species are represented by particular combinations of parameter values. Here, we present models that describe the filling of this multi-dimensional ‘ecospace’ by ecological lifestyles during metazoan diversification. These models reflect varying assumptions about the processes that drove ecological diversification; they contrast diffusive expansion with driven expansion and niche conservatism with niche partitioning. Some models highlight the importance of interactions among organisms (ecosystem engineering and predator–prey escalation) in promoting new lifestyles or eliminating existing ones. These models reflect processes that were not mutually exclusive; rigorous analyses will continue to reveal their applicability to episodes in metazoan history.
Genome-Wide Comparison of Nucleotide-Binding Site-Leucine-Rich Repeat-Encoding Genes inArabidopsis
Authors: Guo Ya-Long , Fitz Joffrey , Schneeberger Korbinian , Ossowski Stephan , Cao Jun , Weigel Detlef
Published: August 2011

Plants, like animals, use several lines of defense against pathogen attack. Prominent among genes that confer disease resistance are those encoding nucleotide-binding site-leucine-rich repeat (NB-LRR) proteins. Likely due to selection pressures caused by pathogens, NB-LRR genes are the most variable gene family in plants, but there appear to be species-specific limits to the number of NB-LRR genes in a genome. Allelic diversity within an individual is also increased by obligatory outcrossing, which leads to genome-wide heterozygosity. In this study, we compared the NB-LRR gene complement of the selfer Arabidopsis  thaliana and its outcrossing close relative Arabidopsis lyrata. We then complemented and contrasted the interspecific patterns with studies of NB-LRR diversity within A. thaliana. Three important insights are as follows: (1) that both species have similar numbers of NB-LRR genes; (2) that loci with single NB-LRR genes are less variable than tandem arrays; and (3) that presence-absence polymorphisms within A. thaliana are not strongly correlated with the presence or absence of orthologs in A. lyrata. Although A. thaliana individuals are mostly homozygous and thus potentially less likely to suffer from aberrant interaction of NB-LRR proteins with newly introduced alleles, the number of NB-LRR genes is similar to that in A. lyrata. In intraspecific and interspecific comparisons, NB-LRR genes are also more variable than receptor-like protein genes. Finally, in contrast to Drosophila, there is a clearly positive relationship between interspecific divergence and intraspecific polymorphisms.
The Arabidopsis Deubiquitinating Enzyme AMSH3 Interacts with ESCRT-III Subunits and Regulates Their Localization
Authors: Katsiarimpa Anthi , Anzenberger Franziska , Schlager Nicole , Neubert Susanne , Hauser Marie-Theres , Schwechheimer Claus , Isono Erika
Published: August 2011

Ubiquitination and deubiquitination regulate various cellular processes. We have recently shown that the deubiquitinating enzyme Associated Molecule with the SH3 domain of STAM3 (AMSH3) is involved in vacuole biogenesis and intracellular trafficking in Arabidopsis thaliana. However, little is known about the identity of its interaction partners and deubiquitination substrates. Here, we provide evidence that AMSH3 interacts with ESCRT-III subunits VPS2.1 and VPS24.1. The interaction of ESCRT-III subunits with AMSH3 is mediated by the MIM1 domain and depends on the MIT domain of AMSH3. We further show that AMSH3, VPS2.1, and VPS24.1 localize to class E compartments when ESCRT-III disassembly is inhibited by coexpression of inactive Suppressor of K+ transport Defect 1 (SKD1), an AAA-ATPase involved in the disassembly of ESCRT-III. We also provide evidence that AMSH3 and SKD1 compete for binding to VPS2.1. Furthermore, we show that the loss of AMSH3 enzymatic activity leads to the formation of cellular compartments that contain AMSH3, VPS2.1, and VPS24.1. Taken together, our study presents evidence that AMSH3 interacts with classical core ESCRT-III components and thereby provides a molecular framework for the function of AMSH3 in plants.
Chance-Constrained Optimal Path Planning With Obstacles
Authors: Blackmore Lars , Ono Masahiro , Williams Brian C.
Published: August 2011

Autonomous vehicles need to plan trajectories to a specified goal that avoid obstacles. For robust execution, we must take into account uncertainty, which arises due to uncertain localization, modeling errors, and disturbances. Prior work handled the case of set-bounded uncertainty. We present here a chance-constrained approach, which uses instead a probabilistic representation of uncertainty. The new approach plans the future probabilistic distribution of the vehicle state so that the probability of failure is below a specified threshold. Failure occurs when the vehicle collides with an obstacle or leaves an operator-specified region. The key idea behind the approach is to use bounds on the probability of collision to show that, for linear-Gaussian systems, we can approximate the nonconvex chance-constrained optimization problem as a disjunctive convex program. This can be solved to global optimality using branch-and-bound techniques. In order to improve computation time, we introduce a customized solution method that returns almost-optimal solutions along with a hard bound on the level of suboptimality. We present an empirical validation with an aircraft obstacle avoidance example.
Discontinuous gas exchange: new perspectives on evolutionary origins and ecological implications
Authors: Chown Steven L.
Published: August 2011

1. When at rest, many insects and some other arthropods exchange gasses discontinuously. Whether or not discontinuous gas exchange (DGE) is adaptive has long been controversial. Several competing evolutionary hypotheses exist, none of which enjoy unequivocal support. This Gordian knot seems now to have been cut.

2. Discontinuous gas exchange appears to arise as a consequence of energy‐saving, metabolic downregulation. Moreover, many ecological circumstances, such as quiescence during daily inactivity and during seasonal resource shortages, are likely to have favoured such downregulation.

3. Once the brain relinquishes control of gas exchange to the segmental ganglia, an interaction between peripheral CO2 sensing and central O2 sensing sets in, leading to the discontinuous pattern.

4. The evolution of DGE may thus be readily explained, with the primary evolutionary hypothesis incorporating a non‐adaptive mechanistic component and an adaptive energy savings one.

5. Paradoxically, though, DGE results in a comparatively high water loss for a given metabolic rate in insects compared with other organisms. Thus, the pattern itself may not have evolved to limit water loss under xeric conditions. Rather, variation in the components of the DGE cycle, which has formed the foundation for much debate concerning the ecological and evolutionary advantages of this gas exchange pattern, may have evolved to do so, accounting for associations between these components and environmental conditions.

6. The relatively high respiratory water loss of insects may spell ecological trouble given increasing metabolic rates of ectotherms associated with rising global temperatures and global change–type drought in many regions.
Predicting phenology by integrating ecology, evolution and climate science
Authors: Pau Stephanie , Wolkovich Elizabeth M. , Cook Benjamin I. , Davies T. Jonathan , Kraft Nathan J. B. , Bolmgren Kjell , Betancourt Julio L. , Cleland Elsa E.
Published: August 2011

Forecasting how species and ecosystems will respond to climate change has been a major aim of ecology in recent years. Much of this research has focused on phenology – the timing of life‐history events. Phenology has well‐demonstrated links to climate, from genetic to landscape scales; yet our ability to explain and predict variation in phenology across species, habitats and time remains poor. Here, we outline how merging approaches from ecology, climate science and evolutionary biology can advance research on phenological responses to climate variability. Using insight into seasonal and interannual climate variability combined with niche theory and community phylogenetics, we develop a predictive approach for species’ reponses to changing climate. Our approach predicts that species occupying higher latitudes or the early growing season should be most sensitive to climate and have the most phylogenetically conserved phenologies. We further predict that temperate species will respond to climate change by shifting in time, while tropical species will respond by shifting space, or by evolving. Although we focus here on plant phenology, our approach is broadly applicable to ecological research of plant responses to climate variability.
Can amphibians take the heat? Vulnerability to climate warming in subtropical and temperate larval amphibian communities
Authors: Duarte Helder , Tejedo Miguel , Katzenberger Marco , Marangoni Federico , Baldo Diego , Beltrán Juan Francisco , Martí Dardo Andrea , Richter‐Boix Alex , Gonzalez‐Voyer Alejandro
Published: August 2011

Predicting the biodiversity impacts of global warming implies that we know where and with what magnitude these impacts will be encountered. Amphibians are currently the most threatened vertebrates, mainly due to habitat loss and to emerging infectious diseases. Global warming may further exacerbate their decline in the near future, although the impact might vary geographically. We predicted that subtropical amphibians should be relatively susceptible to warming‐induced extinctions because their upper critical thermal limits (CTmax) might be only slightly higher than maximum pond temperatures (Tmax). We tested this prediction by measuringCTmaxandTmaxfor 47 larval amphibian species from two thermally distinct subtropical communities (the warm community of the Gran Chaco and the cool community of Atlantic Forest, northern Argentina), as well as from one European temperate community. Upper thermal tolerances of tadpoles were positively correlated (controlling for phylogeny) with maximum pond temperatures, although the slope was steeper in subtropical than in temperate species.CTmaxvalues were lowest in temperate species and highest in the subtropical warm community, which paradoxically, had very low warming tolerance (CTmax–Tmax) and therefore may be prone to future local extinction from acute thermal stress if rising pondTmaxsoon exceeds theirCTmax. Canopy‐protected subtropical cool species have larger warming tolerance and thus should be less impacted by peak temperatures. Temperate species are relatively secure to warming impacts, except for late breeders with low thermal tolerance, which may be exposed to physiological thermal stress in the coming years.
The effects of interpersonal counselling on health‐related quality of life after myocardial infarction
Authors: Oranta Olli , Luutonen Sinikka , Salokangas Raimo KR , Vahlberg Tero , Leino‐Kilpi Helena
Published: August 2011

Aim.  To evaluate the effects of interpersonal counselling on health‐related quality of life after myocardial infarction.

Background.  Depression is a risk factor for poor health‐related quality of life after myocardial infarction. Interpersonal counselling seems to reduce depressive symptoms and distress after myocardial infarction.

Methods.  Myocardial infarction patients (n = 103) were randomised into an intervention group (n = 51) with 1–6 (mean 4·6) interpersonal counselling‐sessions focusing on managing depressive symptoms and a control group (n = 52). Health‐related quality of life after myocardial infarction was measured with EuroQol‐5D (EQ‐5D) in hospital, at six and 18 months after discharge.

Results.  No differences in the changes of health‐related quality of life were found between the groups during follow‐up. However, health‐related quality of life improved significantly in the intervention group. In the group of patients under 60 years, the effect of interpersonal counselling was significant in the intervention group compared with the control group.

Conclusions.  Interpersonal counselling does not seem to improve health‐related quality of life better than standard care after myocardial infarction in general, but it does seem to be beneficial with younger myocardial infarction patients.

Relevance to clinical practice.  There is a need to study the effects of interpersonal counselling further with younger myocardial infarction patients and to develop the intervention further, before using it systematically as part of nursing practice.
Exploring the psychological health related profile of nursing students in Singapore: a cluster analysis
Authors: Chan Moon Fai , Creedy Debra K , Chua Tse Lert , Lim Chi Ching
Published: August 2011

Aim.  To determine whether definable profiles exist in a cohort of nursing student with regard to factors associated with nurses’ perceived emotional intelligence, social support and stress level.

Background.  There is a need to have a basic understanding of a nursing student’s psychological health‐related life quality profile will have a direct effect on their study and contribution to nursing educators to develop an appropriate learning environment for nursing students.

Design.  A descriptive survey.

Methods.  Data were collected in January 2009 in one nursing school in Singapore. A sample of 112 full‐time baccalaureate nursing students from year 1–3 completed the stress in nursing students, social support rating scale and Trait meta‐mood scale.

Results.  Cluster analysis revealed two profiles in four main factors: demographic, perceived emotional intelligence, social support and stress level.

Conclusions.  Findings might help by providing important information for health care professionals to develop interventions that improve students’ psychological health during their university life.

Relevance to clinical practice.  The findings will assist nursing educators or health care professionals by creating psychological health‐related life quality profiles that they can use to develop interventions to improve the health of nursing students.
Nurses’ perceptions of leadership style in hospitals: a grounded theory study
Authors: Su Shu‐Fen , Jenkins Mary , Liu Po‐Erh
Published: August 2011

Aim.  This paper explores the leadership style of hospital managers.

Background.  Leadership has been widely studied in nursing from the perspective of nurses’ psychological strain caused by nursing leadership. There is, however, little contained in the Western and Eastern literatures on the leadership style of hospital managers and certainly no study has explored managers’ leadership style in Taiwanese hospitals from the nurses’ stance.

Design.  Grounded theory.

Methods.  A sample of 28 nurses from seven teaching hospitals in Taiwan, Republic of China was selected through theoretical sampling. A multi‐step analytic procedure based on the grounded theory approach was used to analyse the qualitative data.

Results.  The Chinese culture was found to affect the leadership style of Taiwanese hospital managers. They had extreme power and led nurses in a hierarchical manner. Nurse managers followed the autocratic leadership style of their hospital managers. The main category found in this study was thus hierarchical leadership.

Conclusions.  The Confucian principles of authoritarianism and obedience were found to be part of the Taiwanese hospitals’ organisational cultures and strongly impacted on the managers’ leadership style. Hospital managers’ treatment of doctors and nurses was dependent on their social rankings. Nurses’ lowly ranking fed into these enculturated managerial tendencies of using power and obedience thus increasing psychological strain on nurses.

Relevance to clinical practice.  Managers of the hospitals demonstrate power and misuse obedience through their leadership style, resulting in deterioration of nurses’ work environment. Nurses’ managers are not given enough power by the hospitals in Taiwan. Subsequently, nurses feel themselves the lowest and most powerless subordinates. This study reveals that the Chinese cultural burdens are embedded in the leadership of Taiwanese hospitals. These findings enhance the knowledge of leadership and add to the understanding of managerial attitudes in Chinese hospitals located worldwide.
A single nucleotide deletion in exon 2 produces a novel null allele, HLA‐DRB1*01:33N
Authors: Zimmerman A. , Spruit L. S. , Herczyk W. , Marino S. R.
Published: August 2011

A single nucleotide deletion in codon 12 of the human leukocyte antigen HLA‐DRB1*01 results in a novel null allele, DRB1*01:33N.
Self‐epistemic authority and nurses' reactions to medical information that is retrieved from Internet sites of different credibility
Authors: Barnoy Sivia , Volfin‐Pruss Diana , Ehrenfeld Malka , Kushnir Talma
Published: August 2011

This cross‐sectional study investigated nurses' reactions to Internet medical information that was retrieved from sources of different scientific credibility and the association between self‐epistemic authority and these reactions. The participants filled in questionnaires on their reactions to Internet medical information and self‐epistemic authority. The nurses' reactions to Internet medical information from a highly credible source (Medline) correlated positively with self‐epistemic authority. However, no such correlation was found with Internet medical information from a less credible Internet source (Ynet). Compared with the nurses without an academic degree, the nurses with an academic degree had more positive reactions to the information that was retrieved from Medline. The reactions to the medical information that was retrieved from Ynet did not differ by the education of the nurses. This study shows that nurses' reactions to different sources of Internet information vary according to their level of self‐epistemic authority and education. As patients' use of Internet medical information is increasing, nurses need to expand their expertise in the various professional and popular medical information sites. Such skills will help to reduce any negative feeling that might arise when they encounter patients who present medical information from the Internet.
Discordant effects on central obesity, hepatic insulin resistance, and alanine aminotransferase of low‐dose metformin and thiazolidinedione combination therapy in patients with impaired glucose tolerance
Authors: Retnakaran R. , Ye C. , Hanley A. J. , Harris S. B. , Zinman B.
Published: August 2011

Alanine aminotransferase (ALT) predicts incident type 2 diabetes (T2DM), possibly reflecting early fatty liver and hepatic insulin resistance. Thiazolidinediones and metformin can improve fatty liver and hepatic insulin resistance, respectively. In the Canadian Normoglycemia Outcome Evaluation trial, rosiglitazone/metformin (Rosi/Met, 4/1000 mg) reduced incident T2DM by 66% in subjects with impaired glucose tolerance. For insight on the hepatic effects of this therapy in relation to T2DM, we evaluated the temporal changes in waist, hepatic insulin sensitivity (1/Homeostasis Model Assessment of Insulin Resistance) and ALT in the Rosi/Met (n = 103) and placebo (n = 104) arms over median of 3.9 years. Waist did not differ between the arms. Hepatic insulin sensitivity improved in the Rosi/Met arm in year 1, but deteriorated thereafter as in the placebo arm. In contrast, Rosi/Met lowered ALT in year 1 and maintained this effect throughout the trial. Thus, low‐dose Rosi/Met had no effect on central obesity, a transient effect on hepatic insulin sensitivity, and a sustained effect on ALT.
Adolescent Substance Use Groups: Antecedent and Concurrent Personality Differences in a Longitudinal Study
Authors: Oliva Elizabeth M. , Keyes Margaret , Iacono William G. , McGue Matt
Published: August 2011

This study attempted to extend Shedler and Block's () influential study, which found that adolescent drug experimenters had the healthiest personality functioning compared to abstainers and frequent users. Using a prospective design, we examined the relationship between antecedent and concurrent personality and age‐18 substance use in a community sample of 1,298 twins (96% Caucasian, 49% male). Personality measures at ages 11 and 18 assessed positive emotionality (agentic and communal), negative emotionality, and constraint. Substance use groups—abstainers, experimenters, and problem users—were created at age 18. Age‐18 substance use groups differed in age‐11 and age‐18 constraint such that problem users were lower than experimenters, who were lower than abstainers. Age‐18 substance use groups did not differ in age‐18 positive emotionality. However, abstainers were significantly lower than experimenters in communal positive emotionality, whereas female abstainers scored higher in agentic positive emotionality than female experimenters, who scored higher than female problem users. Experimenters were significantly lower in negative emotionality than problem users. Our findings are inconsistent with the notion that experimenters had the healthiest personality functioning and instead suggest different strengths and weaknesses for each group. Future studies should examine agentic and communal positive emotionality separately.
The Hierarchical Structure of Childhood Personality in Five Countries: Continuity From Early Childhood to Early Adolescence
Authors: Tackett Jennifer L. , Slobodskaya Helena R. , Mar Raymond A. , Deal James , Halverson Charles F. , Baker Spencer R. , Pavlopoulos Vassilis , Besevegis Elias
Published: August 2011

Childhood personality is a rapidly growing area of investigation within individual differences research. One understudied topic is the universality of the hierarchical structure of childhood personality. In the present investigation, parents rated the personality characteristics of 3,751 children from 5 countries and 4 age groups. The hierarchical structure of childhood personality was examined for 1‐, 2‐, 3‐, 4‐, and 5‐factor models across country (Canada, China, Greece, Russia, and the United States) and age group (3–5, 6–8, 9–11, and 12–14 years of age). Many similarities were noted across both country and age. The Five‐Factor Model was salient beginning in early childhood (ages 3–5). Deviations across groups and from adult findings are noted, including the prominent role of antagonism in childhood personality and the high covariation between Conscientiousness and intellect. Future directions, including the need for more explicit attempts to merge temperament and personality models, are discussed.
Translation Alignment: Actor‐Network Theory, Resistance, and the Power Dynamics of Alliance in New Caledonia
Authors: Horowitz Leah S.
Published: August 2011

Abstract:  This study of resistance to multinational mining in New Caledonia expands actor‐network theory's concept of translation by exploring ways that power dynamics affect alliances and the translations that both support and challenge them. Examining relationships among an indigenous protest group, environmentalist grassroots organizations, a human rights lawyer, the mining company, and the provincial government, I argue that power often requires alliances, mediated by compatible translations. However, if alliances are to succeed, at least temporarily, these translations must be made compatible through a process of translation alignment. Ironically, this alignment inevitably alters at least one of the translations, diminishing the power of the actor‐network that articulated it to achieve its original goals. This paper's findings also enhance radical geographical understandings of capitalism's infrastructure, as uneven development increasingly relies upon—yet finds it increasingly difficult to achieve—the alignment of local communities’ translations with those of the agents of industry.
The Development of Ethics: A Historical and Critical Study
Authors: Irwin Terence
Published: August 2011

Editor's Introduction

When Oxford University Press sent us the three enormous volumes of Irwin's The Development of Ethics, we had two thoughts: First, the book is very important and demands a review; second, since human sacrifice is abolished in North America, it will be very difficult to find a reviewer. We handed the volumes to several interested persons, who in the end returned the books saying the task was beyond them. Then, my wife, a lifetime worker at that center of communal thought, the United Nations, suggested that we form a team to review the book. We put an announcement out on the Web, asking for reviewers to do a chapter each, at 250 words a review. We got several hundred volunteers, and chose 82 to review the 96 chapters of Irwin (reviewers got the chapters in Portable Document Format [PDFs], kindly supplied by Oxford). We got 81 of 82 reviews, 75 before the deadline, six slightly later. For purposes of completeness, I filled in the sole missing review. Would that the students in my seminars were so punctual! I would like to thank Elyse Turr at Oxford University Press for the PDFs, and my 82 reviewers for their expertise and diligence. I am grateful to all the volunteers who showed an interest in this strange and perhaps unprecedented project, and who patiently endured the vetting process. Special thanks is due to Laura di Summa, who coordinated all the pieces of this incredible puzzle. Did we accomplish something, something new, by mobilizing 82 minds to review one book? I hope so, but I can now only say what they say on television: “America, it's up to you.”
Age‐related infertility: a tale of two technologies
Authors: Szewczuk Elizabeth
Published: August 2011

The reproductive body has become the site of intensive medical intervention, yet, paradoxically, women have never been more at risk of suffering the distress of infertility. Drawing on in‐depth interviews with 22 infertile women, this article explores their reproductive experience from fertility postponement to assisted conception. All had used both modern contraception and in vitro fertilisation, yet none achieved the fertility they desired, when they desired it. All had structured their use of these technologies around the social practice of postponement. Modern contraception, however, while removing the sexual costs of postponement, did not resolve its reproductive dilemmas. Rather it appeared to collapse the experience of this traditionally difficult process, sustaining an illusion of reproductive control in which fertility decisions were ‘put on the back burner’, undiscussed and sometimes unimagined. For these women this delay then revealed the hidden cost of postponement – infertility – which, in turn, led to their pursuit of assisted conception after the age of 35, at precisely the point when its already limited efficacy begins to fail sharply. In these accounts age‐related infertility emerged as a tale of two technologies: two technologies linked to each woman, and each other, through the social practice of postponement.
The Effect of Employment while in High School on Educational Attainment: A Conditional Difference‐in‐Differences Approach*
Authors: Buscha Franz , Maurel Arnaud , Page Lionel , Speckesser Stefan
Published: August 2011

Using American panel data from the National Education Longitudinal Study of 1988, this article investigates the effect of working during grade 12 on attainment. We employ, for the first time in the related literature, a semiparametric propensity score matching approach combined with difference‐in‐differences. We address selection on both observables and unobservables associated with part‐time work decisions, without the need for instrumental variable. Once such factors are controlled for, little to no effects on reading and math scores are found. Overall, our results therefore suggest a negligible academic cost from part‐time working by the end of high school.
Employment, Inequality and the UK National Minimum Wage over the Medium‐Term*
Authors: Dolton Peter , Bondibene Chiara Rosazza , Wadsworth Jonathan
Published: August 2011

We assess the impact of the national minimum wage (NMW) on employment and inequality in the UK over the decade since its introduction. We evaluate its effects in each year, using an incremental differences‐in‐differences (IDiD) estimator. Identification is based on variation in the bite of the NMW across local labour markets and the different sized year on year up‐ratings. We find that an increased bite of the NMW is associated with falls in lower tail wage inequality. While the average employment effect over the entire period is broadly neutral, there are small but significant positive NMW effects from 2003 onwards.
Estimating Nonlinear Models with Multiple Fixed Effects: A Computational Note*
Authors: Hospido Laura
Published: August 2011

In this paper we consider estimation of nonlinear panel data models that include multiple individual fixed effects. Estimation of these models is complicated both by the difficulty of estimating models with possibly thousands of coefficients and also by the incidental parameters problem; that is, noisy estimates of the fixed effects when the time dimension is short contaminate the estimates of the common parameters due to the nonlinearity of the problem. We propose a simple variation of existing bias‐corrected estimators, which can exploit the additivity of the effects for numerical optimization. We exhibit the performance of the estimators in simulations.
Efficacy of iontophoresis with glycopyrronium bromide for treatment of primary palmar hyperhidrosis
Authors: Chia H.Y. , Tan A.S.L. , Chong W.S. , Tey H.L.
Published: August 2011

Background  There is limited data on the efficacy of iontophoretic treatment of primary palmar hyperhidrosis using glycopyrronium bromide. The first line treatment for primary palmar hyperhidrosis is usually topical aluminium chloride, but clinical experience indicates that it is not effective for more severe disease.

Objective  To evaluate the efficacy of using glycopyrronium bromide iontophoresis in the treatment of primary palmar hyperhidrosis, and to evaluate if the benefit of treatment varies with the severity of disease.

Methods  This is an open‐label study involving patients undergoing weekly treatment of iontophoresis with glycopyrronium bromide for 4 weeks. Gravimetric measurements of sweat production and subjective scores of palmar sweatiness were recorded prior to starting treatment and 1 week after the last treatment. Side‐effects were monitored weekly.

Results  Twenty two of the 25 patients recruited completed the 4‐week treatment. There was a significant mean improvement of 23.4 mg/min (P = 0.001) between baseline and post‐treatment gravimetric measurements. Patients with a higher baseline sweat output demonstrated a trend towards a greater reduction in sweat production (Pearson’s correlation correlation coefficient, r = 0.41). The patients experienced dryness of the palms for a mean duration of 5 days after iontophoresis. All patients reported an improvement in satisfaction scores and 81.8% reported an improvement in subjective severity scores. No serious side‐effects were encountered during the study.

Conclusions  Iontophoresis using glycopyrronium bromide is an effective and well‐tolerated treatment for primary palmar hyperhidrosis. The possibility of its greater benefit in patients with more severe baseline disease requires verification.
Mild to moderate hidradenitis suppurativa treated with local excision and primary closure
Authors: van Rappard D.C. , Mooij J.E. , Mekkes J.R.
Published: August 2011

Background  Hidradenitis suppurativa (HS) is a chronic skin disease with a great impact on quality of life. Treatment with antibiotics or anti‐inflammatory drugs, such as prednisone or TNF‐alpha‐inhibitors usually achieves only temporary improvement. Surgical intervention is considered as the only curative treatment for recurrent lesions.

Objective  To determine the efficacy and patient satisfaction of local excision followed by primary closure.

Methods  Between 2005 and 2010, 92 local excisions with primary closure were performed in 57 patients with mild to moderate HS. All patients were treated on an outpatient basis, under local anaesthesia. Local excision was defined as complete excision of the affected tissue, beyond the borders of activity, leaving clear margins. The medical records were reviewed retrospectively in 2010. The final outcome of the procedure, cosmetic appearance and patient satisfaction was measured using a questionnaire.

Results  Successful treatment, without recurrence, was accomplished in 66% of the cases. The intervention was generally well tolerated: 84% of the patients stated that they would undergo the same surgical procedure again if necessary, and 89% would recommend the procedure to other patients.

Conclusion  Local excision followed by primary closure is a valuable treatment for patients with mild to moderate HS (Hurly stage I & II), with low morbidity and a high patient satisfaction rate.
The effects of online shopping attributes on satisfaction–purchase intention link: a longitudinal study
Authors: Ha Hong‐Youl
Published: August 2011

Attributes of online satisfaction are dynamic. Specifically, it remains to be examined how online shopping attributes empirically affect changes in satisfaction that leads to repurchase behaviours over time and why. The present study develops a theoretical framework for conceptualizing satisfaction with temporal effects and empirically tests it using longitudinal data from 219 online customers. The results indicate that the relationship between attribute‐level evaluations and satisfaction, which has only been examined in terms of predictors of satisfaction in prior literature, is dynamic and changes over time. Changed attributes (particularly convenience and site design) might signal an opportunity to capture the dynamics of attribute‐level evaluations over time. Furthermore, the findings reveal significant temporal effects of satisfaction and purchase intention at time point T on satisfaction and purchase intention at time point T + 1. The results suggest that temporal effects occur as a diagnostic function of a previous attribute rating of a subsequent satisfaction evaluation and the consumer's level of subjective knowledge.
Estimation of Simulated Phosphene Size Based on Tactile Perception
Authors: Lu Yanyu , Chen Panpan , Zhao Ying , Shi Jingru , Ren Qiushi , Chai Xinyu
Published: August 2011

Clinical trials have successfully shown that a visual prosthesis can elicit visual perception (phosphenes) in the visual field. Psychophysical studies based on simulated prosthetic vision offer an effective means to evaluate and refine prosthetic vision. We designed three experiments to examine the effect of phosphene luminance, flicker rate, and eccentricity on the ability to estimate simulated phosphene sizes using tactile perception. Thirty subjects participated in the three experiments. There was a linear increase in reported size as visual stimulus size increased. Judgment was significantly affected by stimulus luminance and eccentricity (P < 0.05) but not by flicker rates. Brighter stimuli were perceived as being larger, and the more eccentric the position, the larger the estimated size. These simulation studies, although idealized, suggested that tactile perception is a potential way to estimate phosphene sizes.
Flow cytometry evaluation of red blood cells mimicking naturally occurring ABO subgroups after modification with variable amounts of function‐spacer‐lipid A and B constructs
Authors: Hult Annika K. , Frame Tom , Chesla Scott , Henry Stephen , Olsson Martin L.
Published: August 2011

BACKGROUND: Kodecytes bearing synthetic blood group A and B antigens are increasingly being used in transfusion laboratories as serologic mimics of red blood cell (RBC) Aweak and Bweak subtypes. The aim of this study was to compare the flow cytometry profile of kodecytes with native ABO subgroups.

STUDY DESIGN AND METHODS: A series of A/B kodecytes, each with decreasing A or B antigen expression, were prepared from group O RBCs that were modified with dilutions of function‐spacer‐lipid KODE technology (FSL) constructs representing a wide serologic range. Using an established flow cytometry method designed for the detection of low levels of A/B antigens, kodecyte profiles were compared with those of native subgroup cells.

RESULTS: Kodecytes with positive tube serology from 4+ to 1+ were created with 15 to 2 µg/mL FSL‐A or 78 to 10 µg/mL FSL‐B transformation solutions. The kodecytes created with higher concentrations of FSL constructs revealed a uniform and/or even distribution of antigens as seen by a single flow cytometry peak more narrow than the broader peaks produced with lower FSL concentrations similar to those found in native Ax and most Bweak subgroups.

CONCLUSIONS: Although kodecytes are created artificially, they can be designed to mimic the serologic and flow cytometric profiles of native ABO subgroup RBCs.
Implant‐guided vertical bone growth in the mini‐pig
Authors: Freilich Martin , Wen Bo , Shafer David , Schleier Peter , Dard Michel , Pendrys David , Ortiz Denise , Kuhn Liisa
Published: August 2011

Objective: To attain and describe guided vertical bone regeneration around titanium (Ti) and titanium zirconium (Ti–Zr) dental implants utilizing non‐glycosylated recombinant human bone morphogenetic protein‐2 (ng/rhBMP‐2), biomaterial scaffolds and a scaffold retainer.

Materials and methods: Thirty‐two modified Straumann TE implants were partially embedded in the mandibles of eight adult mini‐pigs. Pre‐shaped resorbable scaffolds were placed around the implant and shielded and stabilized with a newly developed Ti custom scaffold retainer (umbrella) or wide‐neck (WN) healing caps to stabilize the scaffold. Ng/rhBMP‐2 (50 μg) was applied to the supracrestal portion of the implant or incorporated within the scaffold. At 9 weeks, soft tissue healing was assessed. Vertical bone regeneration outcomes including bone height, bone‐to‐implant contact (BIC) and bone volume were assessed by micro‐computed tomography and histology.

Results: Soft tissue healing at the test sites (+ng/rhBMP‐2/+scaffold) appeared to be substantially better than the control sites (−ng/rhBMP‐2/−scaffold). Bone height, BIC percentage and bone volume were all similar regardless of whether WN healing caps or umbrella scaffold stabilization was used for all biomaterial scaffolds tested. WN healing cap test sites showed greater new bone height and BIC as compared with aggregate data from the control sites (P=0.05). Comparison of aggregate data from the umbrella test sites showed greater BIC and new bone volume as compared with aggregate data from the control sites(P=0.05).

Conclusion: Vertical bone regeneration was successfully attained utilizing ng/rhBMP‐2, biomaterial scaffolds and a scaffold retainer.
Clinical and microbiological characteristics of peri‐implantitis cases: a retrospective multicentre study
Authors: Charalampakis G. , Leonhardt Å. , Rabe P. , Dahlén G.
Published: August 2011

Objectives

The aim of this study was to follow patient cases retrospectively in a longitudinal manner from the time of implant placement to the time they were diagnosed with peri‐implant disease, and to identify associated clinical and microbiological features of peri‐implant disease.

Material and methods

A total of 281 patient cases were chosen from the archives of the Oral Microbiological Diagnostic Laboratory, Gothenburg, Sweden, based on bacterial samples taken from diseased implants. A form was designed and filled in separately for each case including data on patient, implant and disease profile.

Results

Most cases were severe peri‐implantitis cases (91.4%). In 41.3% of the patients, peri‐implantitis was developed early, already after having implants in function less than 4 years. The type of implant surface was significantly associated with the time in years implants were in function, before disease was developed (P < 0.05). The microbiological results by both culture and checkerboard analysis, although failed to fully correspond to the severity of the disease in terms of magnitude, proved to show that peri‐implantitis is a polymicrobial anaerobic infection with increased number of AGNB (aerobic Gram‐negative bacilli) in 18.6% of the patients.

Conclusions

Peri‐implantitis is a biological complication of implants in function that poses a threat to their long‐term survival. It may develop earlier around implants with rough surfaces and it may represent a true infection. Microbiological sampling methods should be improved and uniformed so as to fully unveil the microbiological profile of the disease.
Tryptamine 5‐hydroxylase‐deficient Sekiguchi rice induces synthesis of 5‐hydroxytryptophan and N‐acetyltryptamine but decreases melatonin biosynthesis during senescence process of detached leaves
Authors: Park Sangkyu , Lee Kyungjin , Kim Young‐Soon , Back Kyoungwhan
Published: August 2011

Abstract:  Melatonin biosynthesis was examined in Sekiguchi mutant rice lacking functional tryptamine 5‐hydroxylase (T5H) activity, which is the terminal enzyme for serotonin biosynthesis in rice. During senescence process, the leaves of Sekiguchi mutant rice produced more tryptamine and N‐acetyltryptamine compared with the wild‐type Asahi leaves. Even though T5H activity is absent, Sekiguchi leaves produce low levels of serotonin derived from 5‐hydroxytryptophan, which was found to be synthesized during senescence process. Accordingly, both rice cultivars exhibited similar levels of N‐acetylserotonin until 6 days of senescence induction; however, only Asahi leaves continued to accumulate N‐acetylserotonin after 6 days. In contrast, a large amount of N‐acetyltryptamine was accumulated in Sekiguchi leaves, indicating that tryptamine was efficiently utilized as substrate by the rice arylalkylamine N‐acetyltransferase enzyme. An increase in N‐acetyltryptamine in Sekiguchi had an inhibitory effect on synthesis of melatonin because little melatonin was produced in Sekiguchi leaves at 6 days of senescence induction, even in the presence of equivalent levels of N‐acetylserotonin in both cultivars. The exogenous treatment of 0.1 mmN‐acetyltryptamine during senescence process completely blocked melatonin synthesis.
Extrapineal melatonin: analysis of its subcellular distribution and daily fluctuations
Authors: Venegas Carmen , García José A. , Escames Germaine , Ortiz Francisco , López Ana , Doerrier Carolina , García‐Corzo Laura , López Luis C. , Reiter Russel J. , Acuña‐Castroviejo Darío
Published: August 2011

Abstract:  We studied the subcellular levels of melatonin in cerebral cortex and liver of rats under several conditions. The results show that melatonin levels in the cell membrane, cytosol, nucleus, and mitochondrion vary over a 24‐hr cycle, although these variations do not exhibit circadian rhythms. The cell membrane has the highest concentration of melatonin followed by mitochondria, nucleus, and cytosol. Pinealectomy significantly increased the content of melatonin in all subcellular compartments, whereas luzindole treatment had little effect on melatonin levels. Administration of 10 mg/kg bw melatonin to sham‐pinealectomized, pinealectomized, or continuous light‐exposed rats increased the content of melatonin in all subcellular compartments. Melatonin in doses ranging from 40 to 200 mg/kg bw increased in a dose‐dependent manner the accumulation of melatonin on cell membrane and cytosol, although the accumulations were 10 times greater in the former than in the latter. Melatonin levels in the nucleus and mitochondria reached saturation with a dose of 40 mg/kg bw; higher doses of injected melatonin did not further cause additional accumulation of melatonin in these organelles. The results suggest some control of extrapineal accumulation or extrapineal production of melatonin and support the existence of regulatory mechanisms in cellular organelles, which prevent the intracellular equilibration of the indolamine. Seemingly, different concentrations of melatonin can be maintained in different subcellular compartments. The data also seem to support a requirement of high doses of melatonin to obtain therapeutic effects. Together, these results add information that assists in explaining the physiology and pharmacology of melatonin.
The dynamics of the nucleosome: thermal effects, external forces and ATP
Authors: Blossey Ralf , Schiessel Helmut
Published: August 2011

With nucleosomes being tightly associated with the majority of eukaryotic DNA, it is essential that mechanisms are in place that can move nucleosomes ‘out of the way’. A focus of current research comprises chromatin remodeling complexes, which are ATP‐consuming protein complexes that, for example, pull or push nucleosomes along DNA. The precise mechanisms used by those complexes are not yet understood. Hints for possible mechanisms might be found among the various spontaneous fluctuations that nucleosomes show in the absence of remodelers. Thermal fluctuations induce the partial unwrapping of DNA from the nucleosomes and introduce twist or loop defects in the wrapped DNA, leading to nucleosome sliding along DNA. In this minireview, we discuss nucleosome dynamics from two angles. First, we describe the dynamical modes of nucleosomes in the absence of remodelers that are experimentally fairly well characterized and theoretically understood. Then, we discuss remodelers and describe recent insights about the possible schemes that they might use.