bluuebunny/crossref_metadata_2025 huggingface dataset:
Goodwill accounting and asymmetric timeliness of earnings
Authors: Kim Sohyung , Lee Cheol , Wook Yoon Sung
Published: May 2013

Purpose

The purpose of this paper is to investigate how fair value reporting and increased managerial discretion under the new goodwill accounting affect the asymmetric timeliness of earnings;, i.e. accounting conservatism.

Design/methodology/approach

Various empirical models are applied to a sample of 11,034 firms. To capture a cross‐sectional variation in asymmetric timeliness of earnings, Kahn and Watts' C_Score is adopted.

Findings

It is found that financial reporting for firms with purchased goodwill has become more conservative after the enactment of the new standard. However, once an increase in conservatism that is not attributable to new goodwill accounting is controlled for, it is found that accounting earnings for firms with purchased goodwill become less conservative.

Research limitations/implications

The results should be interpreted with caution, because the effect of concurrent events other than the adoption of SFAS 142 on reported earnings is not perfectly controlled.

Practical implications

The results of this paper support Watts' assertion that new goodwill accounting impairs accounting earnings' ability to reflect the economic earnings in a timely manner, but these results should be interpreted with caution, as the main objective of goodwill accounting is not to improve accounting conservatism.

Originality/value

This paper makes a timely contribution to the debate of fair value accounting by focusing on the impact of SFAS 142 on the asymmetric timeliness of earnings. By employing all available firms with purchased goodwill balances rather than relying on firms that report impairment losses, our research design better captures the impact of SFAS 142 on financial reporting.
“6 and 1” option exchanges and stockholder wealth
Authors: Gupta Atul
Published: May 2013

Purpose

Firms will, at times, replace employee holdings of out‐of‐the‐money stock options with new ones that have lower exercise prices. This paper seeks to examine how stockholders view such actions.

Design/methodology/approach

The stock price reaction to announcements of option exchange programs is used to establish how stockholders view option exchanges. Regression analysis is then used to get insight into firm and program characteristics that explain cross‐sectional differences in the stock price response.

Findings

A positive stock price response indicates that stockholders view such option exchanges as value enhancing. Regression analysis indicates that the price response increases with a firm's growth opportunities, the level of employee turnover, the extent to which employee option holdings are out‐of‐the‐money, and the quality of corporate governance. Deals where only non‐executive employees are allowed to participate are viewed more favourably.

Originality/value

This is the first paper to document that stockholders regard resetting the terms of employee option holdings in a positive vein, confirming implications emerging from theoretical papers on this subject. The paper also documents firm and program characteristics that impact the extent of possible value creation.
Momentum profits and idiosyncratic volatility: the Korean evidence
Authors: Pyo Unyong (Howard) , Jae Shin Yong
Published: May 2013

Purpose

This study aims to focus on the profitability of momentum trading in the Korean stock market. More specifically, it aims to conduct an examination of the relationship between momentum returns and idiosyncratic volatility (IVol) to determine whether momentum profits can be explained by IVol.

Design/methodology/approach

Portfolios are formed based on their past performance and examine the momentum, or contrarian returns, as the difference between winning and losing portfolios. To confirm that the momentum strategy provides excess returns, the relationship between momentum returns and IVol is studied. The Fama and French three‐factor model is also examined to see whether systematic risk affects momentum profits. Firm size, stock price, and turnover are controlled to determine robustness. Finally, a time‐series relationship between aggregate IVol and momentum profits is investigated.

Findings

The paper illustrates that excess returns are obtained from a momentum strategy, not a contrarian strategy, in the Korean stock market. Momentum returns are higher among high IVol stocks, especially high IVol winners. Examining the Fama and French three‐factor model, it is found that momentum returns cannot be explained by systematic risk. The findings are robust after controlling for factors such as firm size, book‐to‐market ratio, and turnover. The paper confirms the effect of IVol on momentum returns by illustrating that a time‐series relationship between momentum returns and aggregate IVol is positive.

Originality/value

This paper is among the first, to the authors' knowledge, to examine the relationship between momentum profits and IVol in the Korean stock market, one of the mature financial markets. The findings in this study can be applied to better understand the sources of gains from the momentum strategy in international stock markets.
From bricolage to thickness: making the most of the messiness of research narratives
Authors: Lambotte François , Meunier Dominique
Published: May 2013

Purpose

The research process is commonly viewed as a succession of linear, structured and planned practices that exclude informal and unplanned practices, engaging with the unexpected or the uncertain. The authors’ aim is to explore this aspect of researching in connection with the narratives of researchers as they oscillate between past and present, theory and empiricism.

Design/methodology/approach

The authors first draw on the concept of “bricolage” to validate informal research practices as researchers seek to lend “thickness” to their research. To deal with the apparent “messiness” of research narratives, they apply the concepts of kairotic time and action nets. Kairotic times are key moments in research narratives when actions, under tension, interconnect to form action nets, which, in turn, generate meaning or knowledge.

Findings

The authors analyse two research episodes. The first recounts how personal experiences and contingencies influence a researcher's choice of research objects and his associated theoretical reflections. The second highlights how some concrete difficulties in choosing a field and gaining access trigger a set of actions that force a researcher to review his initial choices and to reposition himself methodologically. Discussing the concept of kairotic time, the authors show the importance of context and timing and demonstrate how stories build around a gravitational point. From there, they discuss how the concept of action nets, breaking linearity, helps to envision research practice not as a sequence, but as networks of actions that produce scientific outcomes.

Originality/value

This paper provides an operational method of using kairotic time and action nets to account for, and acknowledge, the messiness in research narratives.
Untold stories of the field and beyond: narrating the chaos
Authors: Donnelly Paul F. , Gabriel Yiannis , Özkazanç‐Pan Banu
Published: May 2013

Purpose

The Guest Editors’ intent with this special issue is to tell tales of the field and beyond, but all with the serious end of rendering visible the largely invisible. This paper aims to introduce the articles forming the special issue, as well as reviewing extant work that foregrounds the hidden stories and uncertainties of doing qualitative research.

Design/methodology/approach

The authors advance their arguments through a literature review approach, reflecting on the “state of the field” with regard to doing research and offering new directions on reflexivity as an ethical consideration for conducting qualitative research.

Findings

Far from consigning the mess entailed in doing qualitative research to the margins, there is much to be learned from, and considerable value in, a more thoughtful engagement with the dilemmas we face in the field and beyond, one that shows the worth of what we are highlighting to both enrich research practice itself and contribute to improving the quality of what we produce.

Originality/value

This paper turns the spotlight onto the messiness and storywork aspects of conducting research, which are all too often hidden from view, to promote the kinds of dialogues necessary for scholars to share their fieldwork stories as research, rather than means to a publication end.
Trade productivity upgrading, trade fragmentation, and FDI in manufacturing
Authors: Mora Jesse , Singh Nirvikar
Published: May 2013

Purpose

This paper aims to examine the experience of ten Asian countries with respect to growth, trade and FDI. It seeks to explore relationships between the nature of exports and imports and growth, as well as the relevance of FDI as a channel for these relationships.

Design/methodology/approach

The paper opted for an empirical approach. It included collecting standardize data on international trade, GDP per capita, and FDI inflows. The trade data and GDP data were used in creating the productivity level for exports and imports for all of the relevant countries. The paper analyses how these productivity levels compare to GDP per capita, change over time, and relate to FDI inflows.

Findings

The authors find that FDI is positively correlated with higher productivity levels in exports and imports for many of the countries in their sample. The effect for imports is particularly apparent for imported intermediate goods, reflecting the emergence of greater trade fragmentation. In turn, both imported intermediates and exports that are associated with higher productivity levels are positively correlated with per capita GDP.

Research limitations/implications

There are a couple of research limitations. First, the work does not determine causality; future econometric work should help to identify the causality mechanism. Second, trade fragmentation might lead to an overestimation of “productivity” levels; future work should try to identify the extent of the bias and a way to fix the issue.

Practical implications

This work may have implications for how policymakers view trade and FDI policies, and the possible links between them, in the context of promoting growth.

Social implications

This work may have implications for understanding the links between growth and structural change in the economy, which is in turn linked to societal change.

Originality/value

This paper brings together empirical evidence that integrates discussions of FDI, trade fragmentation and improvements in the productivity of traded goods.
Globalization and inequality: insights from municipal level data in Brazil
Authors: Samy Yiagadeesen , Daudelin Jean
Published: May 2013

Purpose

The relationship between globalization – through trade liberalization – and inequality is unclear. The Stolper‐Samuelson theorem, which is a standard result in trade theory, does not offer compelling answers as globalized economies with an abundance of unskilled labour have seen inequality both worsen, as in China and much of Asia, and improve, as in Latin America. Kuznets' classic model also finds scant confirmation in increasingly open economies, with growth associated with declining inequality in poorer Latin America, and with rising inequality in richer OECD countries. The authors aim to suggest that the key to those anomalies lies in the relative weight of industrialization in a country's growth mix.

Design/methodology/approach

Using census data (for 1991 and 2000) for more than 5,000 municipalities, the authors examine the relationship between income per capita and inequality in Brazil.

Findings

The authors uncover the existence of an “inverted‐U” relationship in 1991 that flipped into a “straight‐U” relationship in 2000, both of which are statistically significant. They argue that the flip results from the association of economic growth with de‐industrialization that is driven by globalization.

Research limitations/implications

In terms of future work, there is a need to examine further the role of de‐industrialization, not only in the case of Brazil but also other emerging economies with different patterns of inequality than the ones currently observed in Latin America and Brazil in particular.

Practical implications

The authors' result reinforces the growing skepticism towards the role of industrialization in economic development, as Brazil sees its most successful period of pro‐poor growth go hand in hand with its de‐industrialization.

Social implications

The authors' result casts doubts about the role of social policy in the current evolution of inequality and poverty in Brazil. The famous Bolsa Familia program, in particular, may have been exaggerated by both the Brazilian government and social policy specialists, as much of the change could be traced to changes in the structure of the economy itself.

Originality/value

This paper contributes to the existing literature on globalization and inequality. It uses municipal level data and identifies a “flip” in the Kuznets relationship. This enables us to make sense of growing inequality in poorer but industrializing economies and in rich ones going through processes of de‐industrialization, and also of declining inequality in poorer de‐industrializing countries such as Brazil.
Household life‐cycle asset allocation and background risk of labor income
Authors: Cai Mingchao , Zhao Jun , Pan Rulu , Huang Haozhi
Published: May 2013

Purpose

The purpose of this paper is to empirically analyze the relationship between risky asset allocation and background risk of Chinese residents.

Design/methodology/approach

Using Chinese macroeconomic data, this study uses numerical method to solve dynamic stochastic optimal problem.

Findings

When risk of labor income is considered, ratio of risky asset declines with rising of age for those people with same age and wealth state; any of the following situations will lead to lower risky assets holdings: lower labor income growth expectations, higher labor income risk or higher labor and financial market covariance risk.

Research limitations/implications

This study uses real economy investment return as a proxy of risky asset return.

Practical implications

Residents with higher background risks should hold less risky assets, and overcome home‐bias problem during asset allocation.

Originality/value

This study takes two kinds of background risk into consideration: labor income risk, and covariance between labor income and risk asset.
Tunneling Transistors Based on Graphene and 2-D Crystals
Authors: Jena Debdeep
Published: May 2013

As conventional transistors become smaller and thinner in the quest for higher performance, a number of hurdles are encountered. The discovery of electronic-grade 2-D crystals has added a new “layer” to the list of conventional semiconductors used for transistors. This paper discusses the properties of 2-D crystals by comparing them with their 3-D counterparts. Their suitability for electronic devices is discussed. In particular, the use of graphene and other 2-D crystals for interband tunneling transistors is discussed for low-power logic applications. Since tunneling phenomenon in reduced dimensions is not conventionally covered in texts, the physics is developed explicitly before applying it to transistors. Though we are in an early stage of learning to design devices with 2-D crystals, they have already been the motivation behind a list of truly novel ideas. This paper reviews a number of such ideas.
Role of Bisoprolol in Patients with Long QT Syndrome
Authors: Fazio Giovanni , Vernuccio Federica , Lo Re Giuseppe , Grutta Giuseppe , Mongiovì Maurizio
Published: May 2013

Background

Long QT syndrome (LQTS) is a disorder of ventricular repolarization usually treated with β‐blockers, mostly with propanolol and nadolol. The aim of our study was to evaluate the role of bisoprolol in LQTS patients.

Methods

A total of 34 patients were evaluated in an average follow‐up time of 93 months: 31 months without treatment, 31 months in treatment with nadolol or propanolol and 31 months in treatment with bisoprolol. The average age of patients at diagnosis was 17.3 years. The enrolled patients were followed through a semiannual electrocardiogram and an annual 24‐hour Holter monitoring. All patients underwent genotyping, routine hematologic tests, and an echocardiogram.

Results

In 93 months there were 2 major and 12 minor cardiovascular events. Both the major events occurred in absence of β‐blocking therapy. Of the 12 minor cardiovascular events 3 occurred in absence of treatment, 7 during treatment with nadolol or propranolol, and 2 during treatment with bisoprolol. The mean heart rate at 24 h Holter was 87 bpm without treatment, 71 bpm in patients treated with propanolol and nadolol, and 70 bpm in patients treated with bisoprolol. There were not statistically significant differences between the three groups in the mean QTc.

Conclusions

Beta‐blocking therapy is the cornerstone of LQTS therapy but actually there is no clear indication about which beta‐blocker should be used. In our experience bisoprolol proved to be less harmful and easier to manage than propranolol and nadolol in patients with LQTS, with the same effectiveness in preventing major cardiovascular events.
Simultaneous ventral hernia repair in bariatric surgery
Authors: Chan Daniel Leonard , Talbot Michael Leonard , Chen Zhuoran , Kwon Sebastianus Chang Mo
Published: May 2013

Background

Obesity is a significant risk factor in abdominal hernia occurrence and recurrence. In patients having bariatric surgery, there are no clear guidelines as to whether repair should be done simultaneously, especially if procedures involve division or resection of part of the gastrointestinal tract.

Methods

A retrospective case series review over a 6‐year period to December 2012 from a prospective database was conducted. As per existing practice for bariatric procedures, patients were followed up indefinitely. Short‐ and long‐term outcomes were analysed.

Results

Forty‐five patients underwent combined laparoscopic bariatric surgery and abdominal wall hernia repair. Of these, 36 had resection procedures (gastric bypass or sleeve gastrectomy) and 9 had non‐resection procedures (gastric banding). The mean operative time was 151 min and the mean length of stay was 3 days. Two patients developed post‐operative mesh seroma infections. To date, there have been no mesh removals or recurrent hernias. There was no mortality in this series.

Discussion

This study demonstrated a low rate of mesh infection (4.44%) at a median follow‐up of 13 months, even when a resectional procedure was performed (5.56%). These results suggest the possible viability and reasonable short‐/long‐term outcomes of simultaneous laparoscopic abdominal wall hernia repair during bariatric surgical procedures, even if the surgery involved division or resection of part of the gastrointestinal tract. This topic is an area of clinical research that warrants further study.
Formal examiner training reflects the increased expertise required of RACS examiners
Authors: Beasley Spencer W. , Lander Richard , Brooks Andrew J. , Hardware Narelle
Published: May 2013

The Fellowship Examination is the final summative assessment before the Surgical Education and Training trainees are awarded Fellowship of the Royal Australasian College of Surgeons. Conducted in nine specialties, it is aligned with the curriculum of each specialty training programme. The Fellowship Examination focuses on specific surgical competencies; in particular, the clinical application of knowledge, operative decision making and professional judgement. As a true ‘exit’ examination, it has to be conducted at the correct cognitive level for surgeons about to enter practice without direct supervision. This requires examiners to have specific skills and expertise for which training is required. This paper outlines the process of training undertaken by newly appointed examiners, and describes some of the areas of knowledge that they have to master before examining at the consistently high level that is now expected.
Lenalidomide at Therapeutic and Supratherapeutic Doses Does Not Prolong QTc Intervals in the Thorough QTc Study Conducted in Healthy Men
Authors: Chen Nianhang , Ye Ying , Liu Liangang , Reyes Josephine , Assaf Mahmoud S. , Kasserra Claudia , Zhou Simon , Palmisano Maria
Published: May 2013

The effect of lenalidomide on the corrected QT (QTc) interval was evaluated in healthy men and extended to patients based on the lenalidomide concentration–QTc (C–QTc) relationship. A rigorous assessment of the effect of lenalidomide on QTc intervals was conducted in healthy volunteers who each received, in randomized order, a single oral dose of 10 mg lenalidomide, 50 mg lenalidomide, 400 mg moxifloxacin (positive control) and placebo. Plasma lenalidomide exposure was compared between healthy volunteers and patients with multiple myeloma or myelodysplastic syndromes. In healthy volunteers, moxifloxacin produced the expected significant prolongation in QTcI (individual correction). For lenalidomide 10 mg and 50 mg, the time‐matched changes from placebo in the baseline‐adjusted least‐squares mean QTcI were <3 ms with the upper limit of the two‐sided 90% confidence interval for the change <10 ms at all time‐points. No subjects experienced QTcI >450 ms or change from baseline >60 ms after lenalidomide administration. Similar results were seen with QT interval data corrected by Fridericia and Bazett methods. The C–QTc analysis yielded no significant association between lenalidomide concentrations and QTcI changes up to 1522 ng/mL; this range was close to that observed in patients receiving lenalidomide doses up to 50 mg, including those with reduced drug clearance due to renal impairment. In conclusion, single doses of lenalidomide up to 50 mg were not associated with prolonged QTc intervals in healthy males. The C–QTc analysis further assured that lenalidomide doses up to 50 mg are not expected to prolong QTc intervals in patients.
Losartan protects liver against ischaemia/reperfusion injury through PPAR‐γ activation and receptor for advanced glycation end‐products down‐regulation
Authors: Koh Eun‐Ji , Yoon Seong‐Jin , Lee Sun‐Mee
Published: May 2013

Background and Purpose

PPAR‐γ has been reported to be a protective regulator in ischaemia/reperfusion (I/R) injury. The receptor for advanced glycation end‐products (RAGE) plays a major role in the innate immune response, and its expression is associated with PPAR‐γ activation. Several angiotensin receptor blockers possess partial agonist activities towards PPAR‐γ. Therefore, this study investigated the action of losartan, particularly with regard to PPAR‐γ activation and RAGE signalling pathways during hepatic I/R.

Experimental Approach

Mice were subjected to 60 min of ischaemia followed by 6 h of reperfusion. Losartan (0.1, 1, 3 and 10 mg·kg−1) was administered 1 h prior to ischaemia and immediately before reperfusion. GW9662, a PPAR‐γ antagonist, was administered 30 min prior to first pretreatment with losartan.

Key Results

Losartan enhanced the DNA‐binding activity of PPAR‐γ in I/R. Losartan attenuated the increased serum alanine aminotransferase activity, TNF‐α and IL‐6 levels, and nuclear concentrations of NF‐κB in I/R. GW9662 reversed these beneficial effects. Losartan caused a decrease in apoptosis as assessed by TUNEL assay, in release of cytochrome c and in cleavage of caspase‐3, and these effects were abolished by GW9662 administration. Losartan attenuated not only I/R‐induced RAGE overexpression, but also its downstream early growth response protein‐1‐dependent macrophage inflammatory protein 2 level; phosphorylation of p38, ERK and JNK; and subsequent c‐Jun phosphorylation. GW9662 reversed these effects of losartan administration.

Conclusions and Implications

Our findings suggest that losartan ameliorates I/R‐induced liver damage through PPAR‐γ activation and down‐regulation of the RAGE signalling pathway.
Improvement of aortic valve stenosis by ApoA‐I mimetic therapy is associated with decreased aortic root and valve remodelling in mice
Authors: Trapeaux J , Busseuil D , Shi Y , Nobari S , Shustik D , Mecteau M , El‐Hamamsy I , Lebel M , Mongrain R , Rhéaume E , Tardif J‐C
Published: May 2013

Background and Purpose

We have shown that infusions of apolipoprotein A‐I (ApoA‐I) mimetic peptide induced regression of aortic valve stenosis (AVS) in rabbits. This study aimed at determining the effects of ApoA‐I mimetic therapy in mice with calcific or fibrotic AVS.

Experimental Approach

Apolipoprotein E‐deficient (ApoE−/−) mice and mice with Werner progeria gene deletion (WrnΔhel/Δhel) received high‐fat diets for 20 weeks. After developing AVS, mice were randomized to receive saline (placebo group) or ApoA‐I mimetic peptide infusions (ApoA‐I treated groups, 100 mg·kg−1 for ApoE−/− mice; 50 mg·kg−1 for Wrn mice), three times per week for 4 weeks. We evaluated effects on AVS using serial echocardiograms and valve histology.

Key Results

Aortic valve area (AVA) increased in both ApoE−/− and Wrn mice treated with the ApoA‐I mimetic compared with placebo. Maximal sinus wall thickness was lower in ApoA‐I treated ApoE−/− mice. The type I/III collagen ratio was lower in the sinus wall of ApoA‐I treated ApoE−/− mice compared with placebo. Total collagen content was reduced in aortic valves of ApoA‐I treated Wrn mice. Our 3D computer model and numerical simulations confirmed that the reduction in aortic root wall thickness resulted in improved AVA.

Conclusions and Implications

ApoA‐I mimetic treatment reduced AVS by decreasing remodelling and fibrosis of the aortic root and valve in mice.
A review of the global literature on dental therapists
Authors: Nash David A. , Friedman Jay W. , Mathu‐Muju Kavita R. , Robinson Peter G. , Satur Julie , Moffat Susan , Kardos Rosemary , Lo Edward C.M. , Wong Anthony H.H. , Jaafar Nasruddin , van den Heuvel Jos , Phantumvanit Prathip , Chu Eu Oy , Naidu Rahul , Naidoo Lesley , McKenzie Irving , Fernando Eshani
Published: May 2013

Objective

Access to adequate oral health care is deficient in many parts of the world. Many countries are now using dental therapists to increase access, particularly for children. To inform the discussion on dental therapists in the workforce, particularly in the United States, the W.K. Kellogg Foundation funded a review of the global literature to identify as many documents as possible related to the practice of dental therapists since the establishment of the School Dental Service in New Zealand in 1921.

Methods

Consultants in each of the countries considered to have a substantive literature on dental therapists were asked to participate in the research; seventeen in total. In addition to identifying and reviewing published articles, a focus of the research was on identifying ‘gray’ documents. Standard databases were searched for key words associated with dental therapists. In addition, searches were conducted of the governmental and dental association websites of all countries known to have dental therapists in their oral health workforce.

Results

Fifty‐four countries, both developing and developed, were identified where dental therapists are members of the workforce. Eleven hundred documents were identified from 26 of these countries, with over 2/3 of them cited in the published monograph. Reliable evidence from the related literature and verbal communication confirmed the utilization of dental therapists in an additional 28 countries. Thirty‐three of the countries were members of the Commonwealth of Nations, suggesting a mechanism of spread from New Zealand.

Variable lengths of training/education existed for dental therapists with the tradition being 2 years postsecondary. In a few countries, the training of therapists and hygienists is now being combined in a three academic year program. Historically, dental therapists have been employed by government agencies caring for children, typically in school‐based programs. Initiatives in some countries allow limited care for adults by dental therapists with additional training.

Conclusions

The evidence indicates that dental therapists provide effective, quality, and safe care for children in an economical manner and are generally accepted both by the public and where their use is established, by the dental profession.
Improving the Economic Management of the Bristol Bay (Alaska) Sockeye Salmon Fishery in the Age of Aquaculture
Authors: Valderrama Diego , Anderson James L.
Published: May 2013

When evaluated using biological criteria, Alaskan salmon fisheries are considered to be among the best managed commercial fisheries in the world. Nevertheless, the economic performance of these fisheries has deteriorated in recent years as a result of a long‐term decline in ex‐vessel prices triggered by exponential growth in the world salmon farming sector, with prices reaching historic lows during the late 1990s and early 2000s. Building on the regulated open‐access model for renewable resources developed by Homans and Wilen (1997), Valderrama and Anderson (2010) conducted a formal examination of market interactions between the Bristol Bay sockeye salmon fishery and the world aquaculture sector. Their study demonstrated that the rents extracted during the initial years of the limited‐entry program were gradually dissipated as a result of overcapacity and price declines caused by aquaculture. In this study, the Valderrama and Anderson (2010) econometric model is used as a framework to evaluate the economic benefits of rights‐based management in the Bristol Bay fishery. The analysis illustrates the efficiency gains that management schemes such as harvesting cooperatives could generate by lowering the level of effort in the fishery. Given that growth in world aquaculture is expected to continue in the foreseeable future, improving efficiency in the fisheries sector is an essential step to restore some of the rents lost to competition with the aquaculture sector.
The extremely resorbed mandible, 10‐year results of a randomized controlled trial on 3 treatment strategies
Authors: Stellingsma Kees , Raghoebar Gerry M. , Visser Anita , Vissink Arjan , Meijer Henny J. A.
Published: May 2013

Objectives

To prospectively compare the clinical and radiographic results of three modes of implant treatment for implant‐retained mandibular overdentures in patients with extremely resorbed mandibles. The three treatment strategies used were (1) a transmandibular implant, (2) augmentation of the mandible with an autologous bone graft followed by placement of four endosseous implants, and (3) placement of four short endosseous implants.

Materials and methods

Sixty edentulous patients met the inclusion criteria and were assigned according to a balanced allocation method to 1 of the 3 treatment strategies. Implant survival, surgical retreatment rates, and peri‐implant bone loss were assessed according to a standardized protocol during a 10‐year evaluation period.

Results

During the evaluation period, significantly more implants were lost in the transmandibular implant (cumulative 10‐year implant survival rate, 76.3%) and the augmentation groups (88%) compared to the group provided with short endosseous implants (98.8%). The 10‐year retreatment rate was significantly more favorable in the endosseous implants only (0%) and augmentation groups (5%) compared to the transmandibular group (30%). In all three groups, there was minor peri‐implant bone loss.

Discussion

Although implant loss is a frequently used outcome measure for success, the necessity of surgical retreatment seems to be of more relevance for both the patient and the clinician.

Conclusion

Considering the favorable clinical and radiographic parameters and the fact that patients can be treated in outdoor clinic setting, the use of short endosseous implants in combination with an overdenture is the first choice of treatment in patients with extremely resorbed mandibles.
A longitudinal study of dental arch morphology in children with the syndrome of Crouzon or Apert
Authors: Reitsma Jacobus H. , Elmi Poejan , Ongkosuwito Edwin M. , Buschang Peter H. , Prahl‐Andersen Birte
Published: May 2013

The aim of this study was to compare changes in dental arch morphology between patients with Crouzon syndrome or Apert syndrome and controls. Children between 4 and 14 yr of age with Crouzon syndrome (n = 40) or Apert syndrome (n = 28) were compared with non‐syndromic controls (n = 457) in terms of arch widths, depths, and length dimensions. Multilevel statistical modeling techniques were used to evaluate changes over time. Dental arch dimensions were found to be smaller in patients with Crouzon syndrome or Apert syndrome compared with control subjects. Maxillary intercanine width for patients with Apert syndrome were increased, whilst other arch width variables showed no change. Patients with Crouzon syndrome showed increases in maxillary intercanine width, whilst intermolar width showed no change over time. Dental arch dimensions in syndromic patients were thus found to be consistently smaller than in control subjects between 4 and 14 yr of age, implying that patients with Crouzon syndrome and Apert syndrome had a diminished growth potential.
Definition of drug‐resistant epilepsy: Is it evidence based?
Authors: Wiebe Samuel
Published: May 2013

Clinical case definitions are the cornerstone of clinical communication and of clinical and epidemiologic research. The ramifications of establishing a case definition are extensive, including potentially large changes in epidemiologic estimates of frequency, and decisions for clinical management. Yet, defining a condition entails numerous challenges such as defining the scope and purpose, incorporating the strongest evidence base with clinical expertise, accounting for patients' values, and considering impact on care. The clinical case definition of drug‐resistant epilepsy, in addition, must address what constitutes an adequate intervention for an individual drug, what are the outcomes of relevance, what period of observation is sufficient to determine success or failure, how many medications should be tried, whether seizure frequency should play a role, and what is the role of side effects and tolerability. On the other hand, the principles of evidence‐based medicine (EBM) aim at providing a systematic approach to incorporating the best available evidence into the process of clinical decision for individual patients. The case definition of drug‐resistant epilepsy proposed by the the International League Against Epilepsy (ILAE) in 2009 is evaluated in terms of the principles of EBM as well as the stated goals of the authors of the definition.
Epilepsy informatics and an ontology‐driven infrastructure for large database research and patient care in epilepsy
Authors: Sahoo Satya S. , Zhang Guo‐Qiang , Lhatoo Samden D.
Published: May 2013

The epilepsy community increasingly recognizes the need for a modern classification system that can also be easily integrated with effective informatics tools. The 2010 reports by the United States President's Council of Advisors on Science and Technology (PCAST) identified informatics as a critical resource to improve quality of patient care, drive clinical research, and reduce the cost of health services. An effective informatics infrastructure for epilepsy, which is underpinned by a formal knowledge model or ontology, can leverage an ever increasing amount of multimodal data to improve (1) clinical decision support, (2) access to information for patients and their families, (3) easier data sharing, and (4) accelerate secondary use of clinical data. Modeling the recommendations of the International League Against Epilepsy (ILAE) classification system in the form of an epilepsy domain ontology is essential for consistent use of terminology in a variety of applications, including electronic health records systems and clinical applications. In this review, we discuss the data management issues in epilepsy and explore the benefits of an ontology‐driven informatics infrastructure and its role in adoption of a “data‐driven” paradigm in epilepsy research.
Ratcheting assessment of materials based on the modified Armstrong–Frederick hardening rule at various uniaxial stress levels
Authors: Ahmadzadeh G. R. , Varvani‐Farahani A.
Published: May 2013

The present study evaluates ratcheting response of materials by means of the Armstrong–Frederick (A–F) hardening rule, the modified A–F rule (Bower's model), and further modifications of the hardening rule based on new introduced coefficients. The implemented modifications on the A–F‐based hardening rule aims to address stages of ratcheting over stress cycles. The modified hardening rule predicts the ratcheting strain rate decay over stage I and the constant rate of strain accumulation during stage II. The modified hardening rule consisted of the coefficients of the hardening rule controlling stress–strain hysteresis loops generated over stress cycles during ratcheting process (Bower's modification on A–F rule) plus the coefficients controlling rates over stages of materials ratcheting deformation. Stress–strain‐dependent coefficients in the modified rule are responsible to compromise overprediction of ratcheting of A–F during stage I and the premature plastic shakedown beyond stage I induced by Bower's model. Ratcheting strain rate coefficients improved the hardening rule capability to calibrate and control the rate of ratcheting in stages I and II and enabled the modified hardening rule to predict ratcheting strain over a prolonged domain of stress cycles. The modified hardening rule was employed to assess ratcheting response of 304, 42CrMo, 316L steel and copper samples under uniaxial loading conditions. The predicted ratcheting values based on the modified hardening rule and the experimental ratcheting strains were found in good agreements.
Effect of leaf litter characteristics on leaf conditioning and on consumption by Gammarus pulex
Authors: Foucreau Natacha , Puijalon Sara , Hervant Frédéric , Piscart Christophe
Published: May 2013

Terrestrial leaf litter inputs provide an essential energy source for many freshwater organisms. Processing of leaf litter involves several physicochemical and biological factors but always starts with the colonisation of leaves by aquatic hyphomycetes.

Here, we document changes occurring on leaf tissues of three tree species, alder, hornbeam and oak, with contrasted leaf properties. Changes in the mechanical properties of leaves and in fungal growth were followed at 10, 25, 35, 45 and 55 days of immersion in natural winter conditions. We hypothesised that fungal growth will be faster and mechanical characteristics will decrease more rapidly in softer, nutrient‐rich, than in tougher leaves. In addition, we tested whether the consumption rate of conditioned leaves by the amphipod shredder Gammarus pulex was correlated with the mechanical properties of leaves and their ergosterol content (as a proxy for fungal biomass).

Leaf toughness decreased (with different rates for the 3 litter species), whereas the leaf thickness remained stable. The mechanical properties of alder and hornbeam leaves changed similarly, in contrast to oak leaves. Ergosterol contents increased over time more rapidly for alder and hornbeam than for oak leaves for which the fungal growth was delayed. Ergosterol content, leaf toughness and leaf consumption rates by G. pulex were significantly correlated. Leaf consumption rates by G. pulex were higher for soft than for tough leaves.

Our results suggest that the consumption of different types of leaves may be delayed according to the time required to acquire conditioning sufficient for shredder consumption. The presence of tough leaves in riparian vegetation may constitute a reservoir of trophic resources available for aquatic organisms at the end of the winter, when soft leaves have been entirely consumed. The diversity of riparian vegetation may hence contribute to sustaining the availability of food resources for adjacent aquatic ecosystems.
CB1 receptor signaling regulates social anxiety and memory
Authors: Litvin Y. , Phan A. , Hill M. N. , Pfaff D. W. , McEwen B. S.
Published: May 2013

The endocannabinoid (eCB) system regulates emotion, stress, memory and cognition through the cannabinoid type 1 (CB1) receptor. To test the role of CB1 signaling in social anxiety and memory, we utilized a genetic knockout (KO) and a pharmacological approach. Specifically, we assessed the effects of a constitutive KO of CB1 receptors (CB1KOs) and systemic administration of a CB1 antagonist (AM251; 5 mg/kg) on social anxiety in a social investigation paradigm and social memory in a social discrimination test. Results showed that when compared with wild‐type (WT) and vehicle‐treated animals, CB1KOs and WT animals that received an acute dose of AM251 displayed anxiety‐like behaviors toward a novel male conspecific. When compared with WT animals, KOs showed both active and passive defensive coping behaviors, i.e. elevated avoidance, freezing and risk‐assessment behaviors, all consistent with an anxiety‐like profile. Animals that received acute doses of AM251 also showed an anxiety‐like profile when compared with vehicle‐treated animals, yet did not show an active coping strategy, i.e. changes in risk‐assessment behaviors. In the social discrimination test, CB1KOs and animals that received the CB1 antagonist showed enhanced levels of social memory relative to their respective controls. These results clearly implicate CB1 receptors in the regulation of social anxiety, memory and arousal. The elevated arousal/anxiety resulting from either total CB1 deletion or an acute CB1 blockade may promote enhanced social discrimination/memory. These findings may emphasize the role of the eCB system in anxiety and memory to affect social behavior.
A comparison of shot‐encoding schemes for wave‐equation migration
Authors: Godwin Jeff , Sava Paul
Published: May 2013

In the last decade the seismic imaging industry has begun collecting data volumes with a substantial amount of data redundancy through new acquisition geometries including: wide‐azimuth, rich‐azimuth and full‐azimuth geometries. The increased redundancy significantly improves image quality in areas with complex geology, but requires considerably greater computational power to construct an image because of the additional data and the need to use advanced imaging algorithms. One way to reduce the computational cost of processing such datasets is to blend shot‐records, using shot‐encoding, together prior to imaging which reduces the number of migrations necessary for imaging. The downside to doing so is that blending introduces strong, non‐physical, cross‐talk noise into the final image. By carefully choosing the shot‐encoding scheme, we can reduce the additional noise inserted into the image and maximally reduce the number of migrations necessary. We describe a theory of blended imaging that explains all shot‐encoding schemes, and use the theory to design a new class of encodings that use amplitude weights instead of phase‐shifts or time‐delays. We are able to use amplitude encoding to produce blended images of the same quality as previous encoding schemes at a similiar computational cost. Furthermore, we compare the results of amplitude encoding with the results from well‐known shot‐encoding schemes from previous work including: plane‐wave migration, random‐time delay, modulated‐shot migration, and decimated shot‐record migration. In our comparison, we find that plane‐wave migration is in many ways an optimal shot‐encoding scheme. However, we find that plane‐wave migration produces results that are comparable to decimated shot‐record migration when the total cost of imaging is taken into account, thereby calling into question the utility of shot‐encoding in general. Overall, this work questions the potential for shot‐encoding in standard (shot‐record) seismic imaging because blended imaging does not appear to sufficiently reduce the cost of imaging given the quality of the blended image compared to decimated shot‐record migration.
Attitudes toward seeking medical care: development and standardization of a comprehensive scale
Authors: Fischer Edward H. , Dornelas Ellen A. , DiLorenzo Terry A.
Published: May 2013

A scale measuring attitudes toward seeking medical help was devised and pretested with college students. The scale was internally consistent and had evident factorial and congruent validity. In a second sample, both the revised scale and its primary attitudinal component—an action–intention subscale—had strong test–retest reliability and correlation with reported medical appointments and contacts assessed approximately 2 months later. In a sample of Hartford, CT residents, the scale's factorial structure was remarkably similar to that of the students. Help‐seeking attitudes differentiated between people who had been treated for a medical crisis and those who had not; those with and without health insurance; and, of the insured, those who considered their coverage adequate and those who did not.
Systematic review of instruments measuring homophobia and related constructs
Authors: Costa Angelo Brandelli , Bandeira Denise Ruschel , Nardi Henrique Caetano
Published: May 2013

Since its conceptualization, the construct of homophobia has been the subject of many speculations about its specificity, reach, and possibility of empirical assessment. Several instruments have been created aiming to measure the prejudice against homosexuals. Peer‐reviewed articles of studies using measures to assess homophobia and related constructs were systematically reviewed in 4 databases (Medline, PsycINFO, ERIC, JSTOR). The articles were classified as they displayed evidence of the instrument's validity, reliability, or both. Finally, the instruments were rated according to that evidence. Out of 1076 results, 115 studies between 1993 and 2010 were identified as relevant. Those studies used 47 different instruments. This review focused in 5 instruments that concentrated the majority of the citations. Psychometric properties were acceptable.
Children's callous‐unemotional traits moderate links between their positive relationships with parents at preschool age and externalizing behavior problems at early school age
Authors: Kochanska Grazyna , Kim Sanghag , Boldt Lea J. , Yoon Jeung Eun
Published: May 2013

Background

Growing research on children's traits as moderators of links between parenting and developmental outcomes has shown that variations in positivity, warmth, or responsiveness in parent–child relationships are particularly consequential for temperamentally difficult or biologically vulnerable children. But very few studies have addressed the moderating role of children's callous‐unemotional (CU) traits, a known serious risk factor for antisocial cascades. We examined children's CU traits as moderators of links between parent–child Mutually Responsive Orientation (MRO) and shared positive affect and future externalizing behavior problems.

Methods

Participants included 100 two‐parent community families of normally developing children, followed longitudinally. MRO and shared positive affect in mother–child and father–child dyads were observed in lengthy, diverse naturalistic contexts when children were 38 and 52 months. Both parents rated children's CU traits at 67 months and their externalizing behavior problems (Oppositional Defiant Disorder and Conduct Disorder) at 67, 80, and 100 months.

Results

Children's CU traits moderated links between early positive parent–child relationships and children's future externalizing behavior problems, even after controlling for strong continuity of those problems. For children with elevated CU traits, higher mother–child MRO and father–child shared positive affect predicted a decrease in mother‐reported future behavior problems. There were no significant associations for children with relatively lower CU scores.

Conclusions

Positive qualities for early relationships, potentially different for mother–child and father–child dyads, can serve as potent factors that decrease probability of antisocial developmental cascades for children who are at risk due to elevated CU traits.