bluuebunny/crossref_metadata_2025 huggingface dataset:
Channel Structure Design for Complementary Products under a Co‐Opetitive Environment
Authors: Pun Hubert
Published: August 2013

In the high‐tech industry, firms can be partners in one respect (e.g., resellers) and competitors in another. In this article, we investigate the channel structure problem for two firms‐each selling competing products in two complementary markets—who are deciding whether to sell their products to customers directly or distribute one of them through a competitor. The customers are heterogeneous and both firms have products that are horizontally differentiated. When selling products directly, the firm can coordinate the prices of the two complementary products and avoid the inefficiency of double marginalization. However, selling (indirectly) through the competing manufacturer can mitigate competition because the competitor shares the profit of both competing products and therefore does not price its own products aggressively. One might expect that when the externality across the markets is strong, firms would prefer to sell both products directly (rather than through the competitor) in order to take advantage of the complementarity between markets and eliminate the inefficiency of double marginalization. Interestingly, we find that even though the first mover chooses to sell both products directly, the second mover forsakes the opportunity to coordinate the prices of its products and instead opts to distribute one of the products through the first mover.
Understanding Drivers of Risk‐Adjusted Performance for Service Firms with International Operations*
Authors: Elango B. , Talluri Srinivas (Sri) , Hult G. Tomas M.
Published: August 2013

This article investigates whether international operations of service firms increase performance while reducing risk. The article draws on a longitudinal dataset of 584 internationally operating service firms from the United States. Analysis indicates that international diversification is negatively related to risk‐adjusted performance. However, it is established that international diversification interacts with internationalization and positively influences risk‐adjusted performance. This finding offers significant promise for firms, as it indicates that international operations (if managed well), through exposure to varied foreign markets coupled with adequate global scope, can lead to firms’ increased risk‐adjusted performance. The results provide a mechanism for decision‐makers to better understand international operations of service firms and present a strategy for achieving success in international markets by effectively managing two important levers: internationalization and international market diversification.
Transaction‐Specific Investments, Relational Norms, and ERP Customer Satisfaction: A Mediation Analysis*
Authors: Lai Fujun , Li Xiaolin , Lai Vincent S.
Published: August 2013

Integrating the perspectives of transaction cost economics, the resource‐based view, and resource dependency theory, this study analyzes the institutional settings of enterprise resource planning (ERP) implementations in China. Specifically, it examines how bilateral transaction‐specific investments (TSIs) and relational governance mechanisms influence customer satisfaction with ERP implementations. The model is empirically tested using data from on‐site interviews with 208 ERP customers in China. The results demonstrate that the effects of vendors’ and customers’ TSIs on customer satisfaction are facilitated by multiple‐stage micromediational chains. The influence of TSIs on customer satisfaction is mediated by relational norms, and the impact of relational norms on customer satisfaction is bridged by perceived service quality and customer trust. Furthermore, the influence of vendors’ TSIs is stronger than the influence of customers’ TSIs. The findings contribute to business research and practice by providing valuable insights into how ERP vendors and customers should strategize TSIs to enhance relationship performance.
Capacity Investment and Product Line Decisions of a Multiproduct Leader and a Focus Strategy Entrant
Authors: Yayla‐Küllü H. Müge
Published: August 2013

In this article, I investigate the capacity investment cost conditions where a multiproduct market leader may respond to a focus strategy entrant by using different strategies such as changing the product mix, production volumes, quality levels, and/or by investing in more capacity. The products offered in the market are quality differentiated and customers are heterogeneous in their willingness to pay for quality. The capacity investment costs of the two firms (i.e., the leader and the entrant) may also be different. The classical Stackelberg model predicts that an incumbent does not change its position in response to entry. However, when heterogeneous customer base, product differentiation, and capacity costs are taken into consideration, I find that the leader with a low capacity cost may choose to expand its product line and increase its production. The leader with low capacity cost may introduce a product that it was holding back when the entrant has to bear the high‐capacity cost and cannibalization threat is relatively small. Nevertheless, the extent of production volume strategies reduces as the capacity cost increases for the leader. I also find that when the leader has the power to set the industry standards by deciding the quality levels, as a response to a high‐quality focused entrant, the leader increases both levels of quality and production of the low‐quality product. Moreover, when the capacity investment cost is high for both the entrant and the leader, I find that market prices may increase with entry.
Liquidity Constraints and Postharvest Selling Behavior: Evidence from China's Maize Farmers
Authors: Sun Dingqiang , Qiu Huanguang , Bai Junfei , Liu Haiyan , Lin Guanghua , Rozelle Scott
Published: August 2013

This paper addresses the impacts of liquidity constraints on household postharvest commodity selling behavior. Using data collected from China's maize farmers, we find that households with debt, in general, sell their maize much earlier than debt‐free households, thus potentially losing inter‐temporal arbitrage opportunities. Segmenting our sample into wealthy and poor households, we find that the relationship between a liquidity constraint and postharvest sales is apparent only among poor households. Using the occurrence of an illness in children or an elderly household member as an instrument for liquidity, we control for potential endogeneity associated with liquidity. We find that poor households in which there were children or elderly people with sicknesses in previous years are more likely to sell maize early than other poor households.
External Shocks and High Volatility in Consumption in Low‐Income Countries
Authors: Kodama Masahiro
Published: August 2013

According to the well‐known concept of consumption smoothing, the volatility of consumption is low even when income is volatile; this is confirmed by data from G7 countries. Surprisingly, however, consumption volatility in many low‐income countries is nontrivially higher than income volatility. Here I examine what causes high consumption volatility in low‐income countries. In general, volatile consumption makes consumers worse off. Therefore, understanding the causes of high consumption volatility can contribute to improving welfare in low‐income countries by suggesting measures to assist in the stabilization of consumption. Unlike much previous research, I focus on international factors when explaining high consumption volatility. The results suggest that external shocks, which are far more volatile in low‐income countries than in industrialized countries, strongly swing consumption. By capturing these mechanisms, the model I use successfully accounts for consumption volatility's differences between the sample low‐income country and sample industrialized country.
Severe obesity and diabetes self‐care attitudes, behaviours and burden: implications for weight management from a matched case‐controlled study. Results from Diabetes MILES—Australia
Authors: Dixon J. B. , Browne J. L. , Mosely K. G. , Rice T. L. , Jones K. M. , Pouwer F. , Speight J.
Published: August 2013

Aims

To investigate whether diabetes self‐care attitudes, behaviours and perceived burden, particularly related to weight management, diet and physical activity, differ between adults with Type 2 diabetes who are severely obese and matched non‐severely obese control subjects.

Methods

The 1795 respondents to the Diabetes MILES—Australia national survey had Type 2 diabetes and reported height and weight data, enabling BMI calculation: 530 (30%) were severely obese (BMI ≥ 35 kg/m2; median BMI = 41.6 kg/m2) and these were matched with 530 control subjects (BMI < 35 kg/m2; median BMI = 28.2 kg/m2). Diabetes self‐care behaviours, attitudes and burden were measured with the Diabetes Self‐Care Inventory—Revised. Within‐group and between‐group trends were examined.

Results

The group with BMI ≥ 35 kg/m2 was less likely to achieve healthy diet and exercise targets, placed less importance on diet and exercise recommendations, and found the burden of diet and exercise recommendations to be greater than the group with BMI < 35 kg/m2. The group with BMI ≥ 35 kg/m2 was more likely to be actively trying to lose weight, but found weight control a greater burden. These issues accentuated with increasing obesity and were greatest in those with BMI > 45 kg/m2. There were no between‐group differences in other aspects of diabetes self‐care: self‐monitoring of blood glucose, use of medications and smoking. Moderate‐to‐severe symptoms of depression were independently associated with reduced likelihood of healthy diet and physical activity, and with greater burden associated with diet, physical activity and weight management.

Conclusions

Severely obese people with diabetes demonstrated self‐care attitudes, behaviours and burdens that infer barriers to weight loss. However, other important diabetes self‐care behaviours are supported equally by severely obese and non‐severely obese individuals.
Ratings Hardwiring and Asset Prices
Authors: Pagratis Spyros
Published: August 2013

This paper discusses the asset pricing implications of ratings hardwiring. The latter is defined as the mechanical response of trading decisions to changes in ratings. This issue is studied within a noisy rational expectations framework of asset pricing under asymmetric information in which traders specialize in different driving factors of asset payoffs and interact with others who mechanically link their asset supply to ratings. We show that ratings hardwiring leads to predictable supply shocks and induces informed traders to overreact to new information, thus creating a channel through which shocks are amplified and prices become less informative and more volatile.
Foliar nutrients explain goldspotted oak borer,Agrilus auroguttatus, adult feeding preference among fourCalifornia oak species
Authors: Chen Yigen , Coleman Tom W. , Jones Michael I. , Flint Mary L. , Seybold Steven J.
Published: August 2013

Adults of the invasive goldspotted oak borer,Agrilus auroguttatusSchaeffer (Coleoptera:Buprestidae), consumed foliar weight in no‐choice feeding tests of, in descending order,California black oakQuercus kelloggiiNewb.,Engelmann oak,Quercus engelmanniiGreene, coast live oak,Quercus agrifoliaNée, and canyon live oak,Quercus chrysolepisLiebm. (Fagaceae). Furthermore, significantly more foliar area was consumed ofQ. kelloggiithan ofQ. chrysolepis. In dual‐choice feeding tests with isolated leaf disks,A. auroguttatusconsumed significantly more foliar weight and area ofQ. kelloggiirelative to the other three oak species, and more foliar weight ofQ. agrifoliathan ofQ. chrysolepis. In dual‐choice feeding tests with leaves on small branches,A. auroguttatusconsumed more foliar weight ofQ. kelloggiithan ofQ. engelmanniiandQ. agrifolia. Thus, multiple experiments suggested that adults ofA. auroguttatuspreferred the foliage ofQ. kelloggiiover that of the other three oak species, and among the other three species they did not appear to have a strong feeding preference. Factor analysis reduced the quantities of 13 foliar nutrients into two new variables (factor 1 and factor 2). Factor 1 was weighted heavily on the quantities of nitrogen, sulfur, phosphorus, potassium, zinc, and copper, whereas factor 2 was weighted heavily on the quantities of zinc, iron, and aluminum. Factor 1 varied by oak species, withQ. kelloggiihaving a higher factor 1 nutrient content than the other three species. Factor 2 response was higher inQ. kelloggii,Q. agrifolia, andQ. engelmanniithan inQ. chrysolepis. The collective effects of four macronutrients (nitrogen, sulfur, phosphorus, and potassium) and two micronutrients (zinc and copper) suggest that these might be the nutrients directing preferential feeding ofA. auroguttatusadults on the foliage ofQ. kelloggii. Leaf toughness might also play an important role in feeding preference. FemaleA. auroguttatusdid not show an ovipositional preference among the four oak species.
Father‐Involvement in a Refugee Sample: Relations between Posttraumatic Stress and Caregiving
Authors: van Ee Elisa , Sleijpen Marieke , Kleber Rolf J. , Jongmans Marian J.
Published: August 2013

Despite increased attention to the role of fathers within families, there is still a dearth of studies on the impact of trauma on father‐involvement. This study investigates the quantity of father‐involvement and the influence of posttraumatic stress on the quality of involvement in a refugee and asylum seeker population. Eighty refugees and asylum seekers and their young children (aged 18–42 months) were recruited. Measures included assessment of parental trauma (Harvard Trauma Questionnaire), quantity and quality of involvement (quantity of caregiving and Emotional Availability Scales), and perception of the father–child relationship (interview). The results show that fathers were less involved in caregiving tasks and play activities than mothers. No parental gender differences were found on each of the Emotional Availability Scales. Traumatic stress symptoms negatively affected the perception and the actual quality of parent–child interaction (sensitivity, structuring, nonhostility). Nevertheless, almost all fathers described their relationship with their child as good and their child as very important to them. As the quality of father‐involvement is of importance to the development of the child, traumatized fathers are as much in need of clinical intervention as mothers. Despite the impact of posttraumatic stress, refugee fathers clearly are involved in the lives of their children. Mechanisms such as a deliberate withdrawal when stressed and compensation might enable affected fathers to step into the interaction when needed, raise the quality of involvement with their child, and diminish the negative impact of stress resulting from trauma and migration.
The epigenetically‐regulated miR‐663 targets H‐ras in K‐562 cells
Authors: Yang Yang , Wang Li‐Li , Wang Heng‐Xiang , Guo Zi‐Kuan , Gao Xiao‐Fang , Cen Jian , Li Yong‐Hui , Dou Li‐Ping , Yu Li
Published: August 2013

miR‐663 is a tumour suppressor that is potentially regulated by modification of CpG islands. Whether aberrant methylation is one of the reasons for miR‐663 down‐regulation in some malignant cells and whether miR‐663 targets oncogenes warrants further research. In the present study, we report that the CpG islands in the upstream region of pre‐miR‐663 are aberrantly methylated in the k‐562 cell line and in the white blood cells of some chronic myelogenous leukaemia patients, and also that H‐ras is one of the genes targeted by miR‐663. Over‐expression of miR‐663 may suppress proliferation of the k‐562 cell line in part by enhancing cell apoptosis.
Administration of low‐dose epoetin‐alpha facilitates adherence to ribavirin in triple therapy with pegylated interferon‐alpha‐2b and telaprevir
Authors: Ishida Hisashi , Sakane Sadatsugu , Toyama Takashi , Fukutomi Keisuke , Kimura Keiichi , Sugimoto Aya , Hibino Kenji , Tamura Takeshi , Iwasaki Tetsuya , Iwasaki Ryuichiro , Hasegawa Hiroko , Sakakibara Yuko , Yamada Takuya , Nakazuru Shoichi , Mita Eiji
Published: August 2013

Aim

Anemia frequently develops in patients given pegylated interferon, ribavirin (RBV), telaprevir (TVR) triple therapy and restricts treatment by forcing reduction or discontinuation of RBV administration. We investigated whether erythropoietin (EPO) could alleviate RBV‐induced anemia to help maintain the RBV dose during the first 12 weeks, the triple therapy phase.

Methods

Twenty‐two patients with hepatitis C virus (HCV) genotype 1 were enrolled. Hemoglobin (Hb) concentration was measured every week. If Hb reduction from the baseline was 2 g/dL or more, 12 000 IU of epoetin‐α was administrated. When further reduction (≥3 g/dL) was observed, 24 000 IU of epoetin‐α was used. Inosine triphosphatase (ITPA) single nucleotide polymorphism (rs1127354) was genotyped for all patients.

Results

Among the 22 patients enrolled in this study, three required RBV dose reduction due to anemia, two had to discontinue or reduce TVR and RBV due to creatinine elevation. The remaining 17 patients completed the treatment during the triple therapy phase without reduction of the RBV dose or adverse events attributable to EPO. Regardless of ITPA genotype, Hb decline was well controlled by EPO administration, whereas the total EPO dose tended to be higher in the CC genotype group. The average adherence to RBV during the triple therapy phase was 97.5%. SVR was achieved in 17 patients; two patients had viral breakthrough and three patients had relapse of HCV RNA.

Conclusion

EPO can be a favorable alternative to reduction of RBV to facilitate the adherence of patients on TVR‐based triple therapy.
Patients' and clinicians' experiences and perceptions of the primary care management of insomnia: qualitative study
Authors: Davy Zowie , Middlemass Jo , Siriwardena Aloysius N.
Published: August 2013

Background

Insomnia is common leading to patients with sleep problems often presenting to primary care services including general practice, community pharmacies and community mental health teams. Little is known about how health professionals in primary care respond to patients with insomnia.

Aim

We aimed to explore health professionals' and patients' experiences and perceptions of the management of insomnia in primary care.

Design

We used a qualitative design and thematic approach.

Setting

Primary care in Nottinghamshire and Lincolnshire.

Method

We undertook focus groups and one‐to‐one interviews with a purposive sample of health professionals and adults with insomnia.

Results

We interviewed 28 patients and 23 health professionals. Practitioners focused on treating the cause of insomnia rather than the insomnia itself. They described providing stepped care for insomnia, but this focused on sleep hygiene which patients often disregarded, rather than cognitive behavioural therapy for insomnia (CBT‐I). Practitioners were ambivalent towards hypnotic drugs but often colluded with patients to prescribe to avoid confrontation or express empathy. Patients sometimes took hypnotics in ways that were not intended, for example together with over‐the‐counter medication. Practitioners and patients were sometimes but not always concerned about addiction. Practitioners sometimes prescribed despite these concerns but at other times withdrew hypnotics abruptly without treating insomnia. Both patients and practitioners wanted more options and better training for the management of insomnia in primary care.

Conclusion

A better understanding of the current approaches and difficulties in the management of insomnia will help to inform more therapeutic options and health professional training.
Fostering intrapreneurial competencies of employees in the education sector
Authors: Boon Jo , Van der Klink Marcel , Janssen Jose
Published: August 2013

Intrapreneurship, a term coined to indicate that entrepreneurial competencies are valuable in any working context, is still a relatively new concept. So far, little attention has been devoted to the development of intrapreneurial competencies in the existing workforce. Starting from the integrated model of entrepreneurship of Bagheri and Pihie, we address the question of the extent to which this model can be applied to intrapreneurial competencies. To this end, in‐depth interviews were conducted with employees and employers in the education sector. Results suggest that the model largely applies to intrapreneurship as well. An important nuance concerns the risk‐taking competency. In addition, both employees and employers stress the role of the organization with respect to displaying intrapreneurial qualities in the first place and in further developing them. The article concludes with recommendations for future research and practice.
Reduction of Ti4+ to Ti3+ in Boron‐Doped BaTiO3 at Very Low Temperature
Authors: Zheng Zhuo Qun , Zhou Xiao Ping
Published: August 2013

Reduction of Ti4+ to Ti3+ was found in boron‐doped BaTiO3 ceramics when we sintered the samples at very low temperature (>850°C) in 5%H2/Ar. Such reduction did not occur in pristine BaTiO3 ceramic. The methods such as UV–vis spectroscopy, luminescence spectroscopy, and X‐ray photoelectron spectroscopy confirmed the reduction by showing the presence of Ti3+. The results of Ti–K‐edge X‐ray absorption near‐edge structure measurement (XANES) indicated that boron doping changed the geometry of Ti‐oxygen in BaTiO3 to some extent. It was likely that some boron ions stayed at interstitial sites of BaTiO3 lattice and acted as donors, which might trigger the reduction. The reduced boron‐doped BaTiO3 were semiconducting and had very low room‐temperature resistivity (<100 Ω m). However, different from the n‐type rare‐earth‐doped BaTiO3 ceramics, they did not display positive temperature coefficient resistance (PTCR) behavior.
Recovery of Atrioventricular Conduction After Pacemaker Placement Following Cardiac Valvular Surgery
Authors: RENE A. GARVEY , SASTRY ASHWANI , HOROWITZ JAMES M. , CHEUNG JIM , LIU CHRISTOPHER F. , THOMAS GEORGE , IP JAMES E. , LERMAN BRUCE B. , MARKOWITZ STEVEN M.
Published: August 2013

Recovery of AV Conduction After Valve Surgery

Background

Atrioventricular block (AVB) occurs commonly after valve surgery, and permanent pacemaker (PPM) implantation is often required. However, the rate and time course of spontaneous recovery of AV conduction in these patients is not known. The goal of this study was to define the rate and risk factors for late high‐grade AVB in patients who have PPM implantation for this indication.

Methods

Serial PPM or defibrillator interrogation data as well as demographic and operative data were reviewed from consecutive patients who had device implantation for AVB following valve surgery. Predictors of late AVB were identified with multiple regression models, and recovery of AV conduction was determined with Kaplan–Meier analyses.

Results

Among 98 patients included in the analysis, 58% (57/98) had evidence of late high‐grade AVB, with a mean follow‐up of 3.6 years. Of the 57 patients with late AVB after PPM implantation, 44 (77%) displayed pacing dependency. In multivariate analyses, persistent AVB in the immediate postoperative period was the only variable associated with late AVB (odds ratio 5.3, 95% confidence interval [2.1, 13.5], P = 0.0006). Among patients who recovered AV conduction within 1 month of surgery, 26% developed AVB during extended follow‐up.

Conclusions

Approximately 40% of patients who received a PPM for AVB after valve surgery displayed no evidence of high‐grade AVB during serial device interrogations. However, simple baseline demographic, operative, and postoperative variables are not sufficiently robust for discriminating those patients with early postoperative AVB who will not need long‐term pacing following valve surgery.
The prevalence of onychomycosis in psoriatic patients: a systematic review
Authors: Klaassen K.M.G. , Dulak M.G. , van de Kerkhof P.C.M. , Pasch M.C.
Published: August 2013

We systematically reviewed all available literature concerning the prevalence of onychomycosis in patients with nail psoriasis and the distribution of pathogens causing onychomycosis in this specific group of patients. Databases searched were Pubmed, EMBASE and the Cochrane Controlled Clinical Trial Register. All studies reporting on the prevalence of onychomycosis in nail psoriasis were obtained, and quality assessment was determined by the STrengthening the Reporting of OBservational studies in Epidemiology checklist. Literature search revealed 720 studies, of which 10 studies met the inclusion criteria. The major limitation of the review was the heterogeneity of the included studies, which prevented the possibility to conduct a meta analysis. However, the average prevalence of 18.0% of onychomycosis in psoriatic patients seems to be increased when compared with control groups and literature on healthy population, even though the ultimate evidence remains lacking. As in the literature hypothesized shift in causative agents from dermatophytes to yeasts and/or moulds could not be confirmed. The clinical consequence of the relatively high prevalence of onychomycosis in psoriasis may be a general advice to rule out onychomycosis or concomitant onychomycosis in these patients with (suspected) nail psoriasis. This advice is stressed by the relative simplicity of treating the contribution of onychomycosis in the nail dystrophy but also the fact that nail psoriasis mostly is treated by immunosuppressive drugs, like steroids, methotrexate or biologics which may aggravate mycotic nail infections.
Who Will Manage Complex Civil Litigation? The Decision to Transfer and Consolidate Multidistrict Litigation
Authors: Williams Margaret S. , George Tracey E.
Published: August 2013

The U.S. Judicial Panel on Multidistrict Litigation may transfer factually related actions filed in different federal districts to a single judge for consolidated pretrial litigation. This transferee judge has significant discretion over the management of the litigation, including ruling on dispositive pretrial motions. Nearly all cases are resolved without returning to the original district court. Thus, as a practical matter, the MDL Panel controls where these disputes will be litigated. And, the MDL Panel has substantial discretion in making that decision. In its first 44 years of existence, the Panel has transferred and consolidated nearly 400,000 lawsuits, including high‐profile securities and derivative lawsuits, large‐scale consumer actions, and mass torts involving products liability claims, common disasters, and air crashes. The Panel's transfer ruling has never been overturned. The current study provides the first systematic and comprehensive empirical investigation of the Panel's decision to transfer and consolidate pending federal civil lawsuits, examining the rationale for transfer and for the selection of a specific district court and judge to handle the consolidated litigation. We find that the Panel grants most motions to transfer and consolidate, but exercises meaningful discretion in choosing where and by whom the cases will be adjudicated. The MDL Panel is much more likely to assign cases to a district court where a current panelist sits and that is supported by at least one defendant and to a district judge who currently serves on the Panel. Thus, the composition of the Panel has a meaningful effect on where and how large‐scale litigation will be resolved.
Rescuing Confidence in the Judicial System: Introducing Lay Participation in Taiwan
Authors: Huang Kuo‐Chang , Lin Chang‐Ching
Published: August 2013

Using Taiwan's 2012 proposal as an illustration, this article discusses a new form of lay participation—the advisory jury—where a group of lay jurors make a collective decision without the professional judges' interference but such decision has no binding effect. This article analyzes how identifying promotion of the public's confidence in the judicial system rather than democratizing judicial decision making by legal elites as the reform purpose leads to the emergence of this form of lay participation. Through a newly conducted national survey, this study shows that the strong support for citizen participation indeed arises from popular dissatisfaction with judicial decision making by professional judges. However, merely half the public are willing to serve and significant disparities in willingness to serve exist across various demographic groups. Our empirical findings inform policymakers of important issues to be addressed in future implementation of citizen participation.
The effects of low arched feet on foot rotation during gait in children with Down syndrome
Authors: Galli M. , Cimolin V. , Rigoldi C. , Pau M. , Costici P. , Albertini G.
Published: August 2013

Background

In children with Down syndrome (DS) hypotonia and ligament laxity are characteristic features which cause a number of orthopaedic issues, such as flat foot. The aim of this study was to determine if children with flat foot are characterised by an accentuated external foot rotation during walking.

Method

Fifty‐five children with DS and 15 typically developing children recruited as control group were assessed using three‐dimensional gait analysis, using an optoelectronic system, force platforms and video recording. Parameters related to foot rotation were identified and calculated and the participants' foot morphology was assessed using the arch index.

Results

Data obtained in this study showed that while DS children without flat foot displayed the foot position on the transverse plane globally close to controls during the whole gait cycle, the DS children with flat foot were characterised by higher extra‐rotation of the foot in comparison with those without flat foot and controls.

Conclusions

Our results suggest that the presence of flatfoot lead the children with DS to extra‐rotate their feet more than the children without flat foot. From a clinical point of view, these results could enhance the rehabilitative programmes in DS.
Emotion dysregulation and social competence: stability, change and predictive power
Authors: Berkovits L. D. , Baker B. L.
Published: August 2013

Background

Social difficulties are closely linked to emotion dysregulation among children with typical development (TD). Children with developmental delays (DD) are at risk for poor social outcomes, but the relationship between social and emotional development within this population is not well understood. The current study examines the extent to which emotion dysregulation is related to social problems across middle childhood among children with TD or DD.

Method

Children with TD (IQ ≥ 85, n = 113) and children with DD (IQ ≤ 75, n = 61) participated in a longitudinal study. Annual assessments were completed at ages 7, 8 and 9 years. At each assessment, mothers reported on children's emotion dysregulation, and both mothers and teachers reported on children's social difficulties.

Results

Children with DD had higher levels of emotion dysregulation and social problems at each age than those with TD. Emotion dysregulation and social problems were significantly positively correlated within both TD and DD groups using mother report of social problems, and within the TD group using teacher report of social problems. Among children with TD, emotion dysregulation consistently predicted change in social problems from one year to the next. However, among children with DD, emotion dysregulation offered no unique prediction value above and beyond current social problems.

Conclusions

Results suggested that the influence of emotion regulation abilities on social development may be a less salient pathway for children with DD. These children may have more influences, beyond emotion regulation, on their social behaviour, highlighting the importance of directly targeting social skill deficits among children with DD in order to ameliorate their social difficulties.
Purine metabolism during neuronal differentiation: the relevance of purine synthesis and recycling
Authors: Göttle Martin , Burhenne Heike , Sutcliffe Diane , Jinnah H. A.
Published: August 2013

Purines are a class of small organic molecules that are essential for all cells. They play critical roles in neuronal differentiation and function. Their importance is highlighted by several inherited disorders of purine metabolism, such as Lesch–Nyhan disease, which is caused by a deficiency of the purine salvage enzyme, hypoxanthine‐guanine phosphoribosyltransferase (HGprt). Despite the known importance of purines in the nervous system, knowledge regarding their metabolism in neurons is limited. In the current studies, purine pools and their metabolism were examined in rat PC6‐3 cells, a PC12 pheochromocytoma subclone that undergoes robust differentiation with nerve growth factor. The results were compared with five new independent PC6‐3 subclones with defective purine recycling because of different mutations affecting HGprt enzyme activity. The results demonstrate an increase in most purines and in energy state following neuronal differentiation, as well as specific abnormalities when purine recycling is lost. The loss of HGprt‐mediated purine recycling also is associated with significant loss of dopamine and related metabolites in the mutant PC6‐3 lines, suggesting an important connection between purine and dopamine pathways. These results provide insights into how purine pools and metabolism change with neuronal differentiation, and how specific enzyme defects may cause neuronal dysfunction.

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Differentiation of dopaminergic PC6‐3 cells is accompanied by increased purine pools and energy state. The lack of a functional purine recycling pathway causes purine limitation in both undifferentiated and differentiated cells, as well as profound loss of dopamine content. The results imply an unknown mechanism by which intracellular purine levels regulate dopamine levels.
Crosstalk between Dopamine D2 receptors and cannabinoid CB1 receptors regulates CNR1 promoter activity via ERK1/2 signaling
Authors: Chiang Yao‐Chang , Lo Yan‐Ni , Chen Jin‐Chung
Published: August 2013

Previously, we found that chronic methamphetamine treatment altered cannabinoid type 1 receptor (CB1R)‐dependent cAMP/PKA/dopamine and cAMP‐regulated phosphoprotein of Mr 32 000 (DARPP‐32)/T34/PP2B signaling and decreased levels of CB1R protein and mRNA in the nucleus accumbens. These findings suggested the existence of signaling interplay between mesolimbic dopamine and CB1R. In this study, we further investigate interactions between CB1R and dopamine D2 receptor (D2R) signaling. Activation of either CB1R or D2R increased extracellular signal‐regulated kinases 1 and 2 (ERK1/2) phosphorylation, while co‐stimulation of CB1R and D2R evoked an additive effect on the phospho‐ERK1/2 signal. This effect was mediated through a pertussis toxin‐sensitive Gαi/o pathway in primary striatal cells. Furthermore, the mRNA level of CB1R was increased via dopamine D2 receptor short form (D2SR) by treatment with D2R agonist quinpirole in D2SR/C6 glioma cells. This effect could be suppressed by co‐treatment with the ERK1/2 inhibitor U0126. To test if D2SR could transcriptionally regulate CB1R, the 5′‐untranslated region (5′‐UTR) of the cannabinoid receptor 1 (CNR1) gene was sequenced from rat brain. Results showed that the CNR1 gene includes two exons, which contain 375 bp of 5′‐UTR and are separated by a 17‐kb intron. A luciferase reporter assay showed that the maximal D2SR‐responsive promoter activity is located in the −1 to −222 region of CNR1 promoter. Overall, we demonstrate previously unidentified crosstalk between D2R and CB1R via ERK1/2 signaling that enhances the expression of CB1R by modulating its promoter activity.

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Cannabinoid CB1R and dopamine D2R cross‐talk at ERK1/2 signal. Activation of D2SR increases the CB1R transcription, which is ERK1/2 dependent and enhances CB1R promoter activity that requires up‐stream −1 to −222 region. The results implicate pre‐synaptic D2SR could functionally regulate the retrograde cannabinoid signal in the striatum.
Effects of essential amino acid deficiency: down‐regulation of KCC2 and the GABAA receptor; disinhibition in the anterior piriform cortex
Authors: Sharp James W. , Ross‐Inta Catherine M. , Baccelli Irène , Payne John A. , Rudell John B. , Gietzen Dorothy W.
Published: August 2013

The anterior piriform cortex (APC) is activated by, and is the brain area most sensitive to, essential (indispensable) amino acid (IAA) deficiency. The APC is required for the rapid (20 min) behavioral rejection of IAA deficient diets and increased foraging, both crucial adaptive functions supporting IAA homeostasis in omnivores. The biochemical mechanisms signaling IAA deficiency in the APC block initiation of translation in protein synthesis via uncharged tRNA and the general amino acid control kinase, general control nonderepressing kinase 2. Yet, how inhibition of protein synthesis activates the APC is unknown. The neuronal K+Cl− cotransporter, neural potassium chloride co‐transporter (KCC2), and GABAA receptors are essential inhibitory elements in the APC with short plasmalemmal half‐lives that maintain control in this highly excitable circuitry. After a single IAA deficient meal both proteins were reduced (vs. basal diet controls) in western blots of APC (but not neocortex or cerebellum) and in immunohistochemistry of APC. Furthermore, electrophysiological analyses support loss of inhibitory elements such as the GABAA receptor in this model. As the crucial inhibitory function of the GABAA receptor depends on KCC2 and the Cl− transmembrane gradient it establishes, these results suggest that loss of such inhibitory elements contributes to disinhibition of the APC in IAA deficiency.

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The circuitry of the anterior piriform cortex (APC) is finely balanced between excitatory (glutamate, +) and inhibitory (GABA, −) transmission. GABAA receptors use Cl−, requiring the neural potassium chloride co‐transporter (KCC2). Both are rapidly turning‐over proteins, dependent on protein synthesis for repletion. In IAA (indispensable amino acid) deficiency, within 20 min, blockade of protein synthesis prevents restoration of these inhibitors; they are diminished; disinhibition ensues. GCN2 = general control non‐derepressing kinase 2, eIF2α = α‐subunit of the eukaryotic initiation factor 2.
Metabolic products of [2‐13C]ethanol in the rat brain after chronic ethanol exposure
Authors: Wang Jie , Du Hongying , Ma Xiaoxian , Pittman Brian , Castracane Laura , Li Ting‐Kai , Behar Kevin L. , Mason Graeme F.
Published: August 2013

Most ingested ethanol is metabolized in the liver to acetaldehyde and then to acetate, which can be oxidized by the brain. This project assessed whether chronic exposure to alcohol can increase cerebral oxidation of acetate. Through metabolism, acetate may contribute to long‐term adaptation to drinking. Two groups of adult male Sprague–Dawley rats were studied, one treated with ethanol vapor and the other given room air. After 3 weeks the rats received an intravenous infusion of [2‐13C]ethanol via a lateral tail vein for 2 h. As the liver converts ethanol to [2‐13C]acetate, some of the acetate enters the brain. Through oxidation the 13C is incorporated into the metabolic intermediate α‐ketoglutarate, which is converted to glutamate (Glu), glutamine (Gln), and GABA. These were observed by magnetic resonance spectroscopy and found to be 13C‐labeled primarily through the consumption of ethanol‐derived acetate. Brain Gln, Glu, and, GABA 13C enrichments, normalized to 13C‐acetate enrichments in the plasma, were higher in the chronically treated rats than in the ethanol‐naïve rats, suggesting increased cerebral uptake and oxidation of circulating acetate. Chronic ethanol exposure increased incorporation of systemically derived acetate into brain Gln, Glu, and GABA, key neurochemicals linked to brain energy metabolism and neurotransmission.

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The liver converts ethanol to acetate, which may contribute to long‐term adaptation to drinking. Astroglia oxidize acetate and generate neurochemicals, while neurons and glia may also oxidize ethanol. When 13C‐ethanol is administered intravenously, 13C‐glutamine, glutamate, and GABA, normalized to 13C‐acetate, were higher in chronic ethanol‐exposed rats than in control rats, suggesting that ethanol exposure increases cerebral oxidation of circulating acetate.
Glucagon‐Like Peptide‐1 Receptor Agonist Administration Suppresses Both Water and Saline Intake in Rats
Authors: McKay N. J. , Daniels D.
Published: August 2013

Glucagon‐like peptide‐1 (GLP‐1) plays an important role in energy homeostasis. Injections of GLP‐1 receptor (GLP‐1R) agonists suppress food intake, and endogenous GLP‐1 is released when nutrients enter the gut. There is also growing evidence that the GLP‐1 system is involved in the regulation of body fluid homeostasis. GLP‐1R agonists suppress water intake independent of their effects on food intake. It is unknown, however, whether this suppressive effect of GLP‐1R agonists extends to saline intake. Accordingly, we tested the effect of the GLP‐1R agonists liraglutide (0.05 μg) and exendin‐4 (0.05 μg) on water and saline intake, as stimulated either by angiotensin II (AngII) or by water deprivation with partial rehydration (WD‐PR). Each agonist suppressed AngII‐induced water intake; however, only exendin‐4 suppressed saline intake. WD‐PR‐induced water and saline intakes were both attenuated by each agonist. Analysis of drinking microstructure after WD‐PR found a reliable effect of the agonists on burst number. Furthermore, exendin‐4 conditioned a robust taste avoidance to saccharine; however, there was no similar effect of liraglutide. To evaluate the relevance of the conditioned taste avoidance, we tested whether inducing visceral malaise by injection of lithium chloride (LiCl) suppressed fluid intake. Injection of LiCl did not suppress water or saline intakes. Overall, these results indicate that the fluid intake suppression by GLP‐1R activation is not selective to water intake, is a function of post‐ingestive feedback, and is not secondary to visceral malaise.
The effect of low‐level laser therapy on the healing of hard palate mucosa and the oxidative stress status of rats
Authors: Firat Ela Tules , Dağ Ahmet , Günay Ahmet , Kaya Beyza , Karadede Mehmet İrfan , Ersöz Kanay Berna , Ketani Aydın , Evliyaoğlu Osman , Uysal Ersin
Published: August 2013

Objective

The biostimulation effects of low‐level laser therapy (LLLT) have been demonstrated recently. This study investigated the effects of LLLT on palatal mucoperiosteal wound healing and oxidative stress status in rats.

Material and method

Forty‐two male Wistar rats weighing 250–300 g were used in this study. A standardized full‐thickness wound was created in the mucoperiosteum of the hard palates of the rats using a 3‐mm‐diameter biopsy punch. Treatment using a GaAlAs laser at a wavelength of 940 nm and a dose of 10 J/cm2 was initiated after surgery and repeated on the 2nd, 4th, and 6th days post‐surgery. Seven animals from each group were sacrificed on the 7th, 14th, and 21st days after surgery. Total antioxidant status and total oxidative status were measured in serum.

Results

The histopathological findings revealed reduced numbers of inflammatory cells on the 7th day, increased mitotic activity of fibroblasts on the 14th and 21st day, and the same degree of collagen synthesis and vascularization on the days 7, 14, and 21 in the LLLT group compared with the control group. No significant differences in total oxidative status and total antioxidant status were observed between the groups.

Conclusion

LLLT using a GaAlAs laser at a wavelength of 940 nm and a dose of 10 J/cm2 elicited a positive healing effect on palatal mucoperiosteal wounds likely via the induction of fibroblasts. The oxidative stress status was not affected by LLLT.
Selection and Socialization of Aggressive and Prosocial Behavior: The Moderating Role of Social‐Cognitive Processes
Authors: Molano Andres , Jones Stephanie M. , Brown Joshua L. , Aber J. Lawrence
Published: August 2013

This study evaluated the extent to which fourth‐grade students (M age = 8.62) select and are influenced by their peers' aggressive and prosocial behavior and the extent to which intra‐individual social cognitions moderate these processes. Two waves of data were collected in the fall and spring of one academic year from children attending 18 New York City public elementary schools. Stochastic actor‐based social network analysis was used to evaluate whether participants modify their network or behavior in response to the behavior of their peers. Findings support an average main effect of peer influence of aggression, as well as an interaction indicating that participants with high levels of hostile attributional bias have higher odds of adopting the aggressive behavior of their peers.
Social Goals and Adolescent Friendships: Social Selection, Deselection, and Influence
Authors: Ojanen Tiina , Sijtsema Jelle J. , Rambaran Ashwin J.
Published: August 2013

This study examined adolescent friendship selection and social influence with regard to agentic (status and power) and communal (closeness and affiliation) goals at three waves during middle school (N = 504; 12–14 years; 53% boys). Meta‐level findings across four friendship networks indicated social influence for both goal orientations: friends grew more similar to each other in agentic as well as communal goals. Moreover, in one friendship network, similarity in agentic goals predicted friendship deselection or termination of these relationships over time. Theoretical and practical implications for the study of adolescent social goals and friendships are discussed.
Breastfeeding practices and child growth outcomes in Haiti: an analysis of data from Demographic and Health Surveys
Authors: Heidkamp Rebecca , Ayoya Mohamed Ag , Teta Ismael Ngnie , Stoltzfus Rebecca J. , Marhone Joseline Pierre
Published: August 2013

Haiti's national nutrition policy prioritises breastfeeding, but limited data are available to inform strategy. We examined national trends in early initiation of breastfeeding (ErIBF) and exclusive breastfeeding (EBF) over a 10‐year period using data from three Haitian Demographic and Health Surveys (1994–1995, 2000 and 2005–2006). We used multivariate regression methods to identify determinants of ErIBF and EBF in the 2005–2006 data set and to examine relationships to growth. There was no change in ErIBF across surveys [1994–1995: 36.6%, 95% confidence interval (CI) 29.9–43.9; 2000: 49.4%, 95% CI 44.1–54.8; 2005–2006: 43.8%, 95% CI 40.5–47.1]. EBF among 0–5‐month‐olds increased sharply (1994–18995: 1.1%, 95% CI 0.4–3.2; 2000: 22.4%, 95% CI 16.5–29.5; 2005–2006: 41.2%, 95% CI 35.4–47.2). The proportion of breastfeeding children 0–5 months who received soft, solid or semi‐solid foods decreased (1994–1995: 68.5%, 95% CI 57.3–77.9; 2000: 46.3%, 95% CI 39.3–53.4; 2005–2006: 30.9%, 95% CI 25.9–36.5). Child age at time of survey [odds ratio (OR) 1.73; P = 0.027], lower maternal education (OR = 2.14, P = 0.004) and residence in the Artibonite Department (OR 0.31; P = 0.001) were associated with ErIBF among children 0–23 months. Age group and department were significant predictors of EBF among children 0–5 months. ErIBF was associated with higher weight‐for‐age z‐scores [effect size (ES) 0.22; P = 0.033] and height‐for‐age z‐scores (ES 0.20; P = 0.044). There was no statistically significant relationship between EBF and growth. The 10‐year ErIBF and EBF trends in Haiti echo global and regional trends. ErIBF and EBF are related practices but with different determinants in the Haitian context. These differences have implications for intervention delivery.