bluuebunny/crossref_metadata_2025 huggingface dataset:
Controlling attention to gaze and arrows in childhood: an fMRI study of typical development and Autism Spectrum Disorders
Authors: Vaidya Chandan J. , Foss‐Feig Jennifer , Shook Devon , Kaplan Lauren , Kenworthy Lauren , Gaillard William D.
Published: March 2011

Functional magnetic resonance imaging was used to examine functional anatomy of attention to social (eye gaze) and nonsocial (arrow) communicative stimuli in late childhood and in a disorder defined by atypical processing of social stimuli, Autism Spectrum Disorders (ASD). Children responded to a target word (‘LEFT’/‘RIGHT’) in the context of a distracting arrow or averted gaze pointing in a direction that was congruent, incongruent, or neutral (bar without arrowheads, central gaze) relative to the target word. Despite being irrelevant to the target task, both arrow and averted gaze facilitated responses (Congruent vs. Neutral trials) to the same extent in the two groups and led to interference (Incongruent vs. Congruent trials), which was greater from arrows in ASD than control children. In the brain, interaction between group and distracter‐domain was observed in frontal‐temporal regions during facilitation and frontal‐striatal regions during interference. During facilitation, regions associated with attention to gaze in control children (left superior temporal sulcus, premotor) were associated with attention to arrows in ASD children; gaze was associated with medial temporal involvement in ASD children. During interference, regions associated with arrows in control children (anterior cingulate, right caudate) were activated in response to gaze in ASD children; further, left dorsolateral prefrontal cortex, a region not observed in control children, was activated during gaze‐interference in ASD children. Thus, functional anatomy was atypical in ASD children during spontaneous processing of social and nonsocial communicative cues.
Exploring Non‐Linear Relationship of Blendshape Facial Animation
Authors: Liu Xuecheng , Xia Shihong , Fan Yiwen , Wang Zhaoqi
Published: March 2011

Human face is a complex biomechanical system and non‐linearity is a remarkable feature of facial expressions. However, in blendshape animation, facial expression space is linearized by regarding linear relationship between blending weights and deformed face geometry. This results in the loss of reality in facial animation. To synthesize more realistic facial animation, aforementioned relationship should be non‐linear to allow the greatest generality and fidelity of facial expressions. Unfortunately, few existing works pay attention to the topic about how to measure the non‐linear relationship. In this paper, we propose an optimization scheme that automatically explores the non‐linear relationship of blendshape facial animation from captured facial expressions. Experiments show that the explored non‐linear relationship is consistent with the non‐linearity of facial expressions soundly and is able to synthesize more realistic facial animation than the linear one.
The Effects of Input‐Based Practice on Pragmatic Development of Requests in L2 Chinese
Authors: Li Shuai
Published: March 2011

This study examined the effects of input‐based practice on developing accurate and speedy requests in second‐language Chinese. Thirty learners from intermediate‐level Chinese classes were assigned to an intensive training group (IT), a regular training group (RT), and a control group. The IT and the RT groups practiced using four Chinese request‐making forms via computerized structured input activities over 2 consecutive days. During this time, the IT group practiced using the request‐making forms twice as much as the RT group. The control group did not practice. The results show that the input‐based practice was effective in promoting accuracy in an Oral Discourse Completion Task and in enhancing speed in a Pragmatic Listening Judgment Task. No other effects of practice were observed.
Socio‐Interactive Practices and Personality in Adult Learners of English With Little Formal Education
Authors: Ramírez‐Esparza Nairán , Harris Kathryn , Hellermann John , Richard Clemence , Kuhl Patricia K. , Reder Steve
Published: March 2011

Drawing on a large corpus of video‐recorded classroom data, the goal of this study was to understand the processes and mechanisms associated with learning in individuals who have had little education in their home countries. In order to accomplish this goal, we measured the socio‐interactive behaviors and the expression of personality behaviors in learners who attended classes to learn English as a second language, and we analyzed the relationship between socio‐interactive behaviors and personality with literacy test scores. The results showed that low‐education learners behaved differently in the classroom than high‐education learners. Socio‐interactive behaviors and personality behaviors were related to literacy test scores. Implications of educational background on learning are discussed as well as the limitations and unique contributions of this study.
Teacher Motivational Practice, Student Motivation, and Possible L2 Selves: An Examination in the Iranian EFL Context
Authors: Papi Mostafa , Abdollahzadeh Esmaeel
Published: March 2011

The present study aims to provide observational evidence on the relationship between teachers' use of motivational strategies and students' motivated behavior in the English as a foreign language (EFL) context of Iran. To this end, 741 male learners of English from 26 secondary school classes taught by 17 teachers participated in the study. The teachers' use of motivational strategies and the students' motivated behavioral codes were measured using a classroom observation instrument originally developed by Guilloteaux and Dörnyei (2008). Furthermore, the participating students completed a questionnaire that consisted of both situation‐specific and general‐motivational scales. Finally, a post hoc rating scale was employed to evaluate the teachers' overall motivational practice. The results showed that the teachers' motivational practice is significantly related to the students' motivated behavior. Further, while no differences were found between high‐motivation and low‐motivation learner groups in terms of their ideal second language (L2) selves, the low‐motivation group had stronger ought‐to L2 selves. The results will be discussed with reference to the socio‐educational context of Iran.
Measurement of motor root conduction time at the early stage of Guillain–Barre syndrome
Authors: Temuçin Ç. M. , Nurlu G.
Published: March 2011

Background and purpose:  As they are mainly performed at distal nerve parts, routine electrophysiological examinations can fail to detect the abnormalities at the early stage of Guillain–Barre syndrome (GBS) because of predominant involvement of proximal nerve segments. Measurements focused on proximal conduction can provide additional findings. We investigated the diagnostic significance of motor root conduction time (MRCT) at the early stage of GBS.

Methods:  Study was performed in 30 healthy volunteers and within the first week of 12 patients with GBS. MRCT was calculated as the latency differences between motor nerve conduction time (MNCT) obtained by cervical magnetic stimulation and total peripheral motor conduction time obtained by electrical stimulation of ulnar nerve. Also MNCT/MRCT ratio was calculated in each subject.

Results:  There were statistically significant differences between groups for MRCT (P < 0.0001) and MNCT/MRCT ratio (P < 0.0001). Although the F‐wave latency at ulnar nerve was abnormal only in 33%, MRCT was significantly prolonged in 83% of patients. In three patients, prolongation of MRCT was the only abnormality at the first electrodiagnostic examination.

Conclusions:  Motor root conduction time as a non‐invasive method can provide additional and confirmative information at the early stage of GBS in which routine nerve conduction studies may fail to detect the focal demyelination.
The incidence and prevalence of idiopathic intracranial hypertension in Sheffield, UK
Authors: Raoof N. , Sharrack B. , Pepper I. M. , Hickman S. J.
Published: March 2011

Background and purpose:  The purpose of this study was to identify the incidence and prevalence of idiopathic intracranial hypertension (IIH) in Sheffield, UK.

Methods:  A retrospective review of case notes was conducted to identify cases of IIH seen between 1 January 2007 and 31 December 2008.

Results:  Sixteen (15 women and 1 man) new patients were identified to give an incidence within Sheffield of 1.56/100 000/year and 2.86/100 000/year for women. The incidence of IIH in obese women was 11.9/100 000/year. The prevalence of IIH was calculated as 10.9/100 000, and 85.7/100 000 in obese women.

Conclusion:  A higher incidence of IIH than previously reported UK data was found, which may be because of increasing obesity within the population, or improved case ascertainment.
Ultrasound detection and identification of cosmetic fillers in the skin
Authors: Wortsman X. , Wortsman J. , Orlandi C. , Cardenas G. , Sazunic I. , Jemec G.B.E.
Published: March 2011

Background  While the incidence of cosmetic filler injections is rising world‐wide, neither exact details of the procedure nor the agent used are always reported or remembered by the patients. Thus, although complications are reportedly rare, availability of a precise diagnostic tool to detect cutaneous filler deposits could help clarify the association between the procedure and the underlying pathology.

Objectives  The aim of this study was to evaluate cutaneous sonography in the detection and identification of cosmetic fillers deposits and, describe dermatological abnormalities found associated with the presence of those agents.

Methods  We used ultrasound in a porcine skin model to determine the sonographic characteristics of commonly available filler agents, and subsequently applied the analysis to detect and identify cosmetic fillers among patients referred for skin disorders.

Results  Fillers are recognizable on ultrasound and generate different patterns of echogenicity and posterior acoustic artefacts. Cosmetic fillers were identified in 118 dermatological patients; most commonly hyaluronic acid among degradable agents and silicone oil among non‐degradable. Fillers deposits were loosely scattered throughout the subcutaneous tissue, with occasional infiltration of local muscles and loco‐regional lymph nodes. Accompanying dermatopathies were represented by highly localized inflammatory processes unresponsive to conventional treatment, morphea‐like reactions, necrosis of fatty tissue and epidermal cysts; in the case of non‐degradable agents, the associated dermatopathies were transient, resolving upon disappearance of the filler.

Conclusions  Cosmetic filler agents may be detected and identified during routine ultrasound of dermatological lesions; the latter appear to be pathologically related to the cosmetic procedure.
Effect of psoriasis therapy on VEGF and its soluble receptors serum concentrations
Authors: Flisiak I. , Zaniewski P. , Rogalska‐Taranta M. , Chodynicka B.
Published: March 2011

Background  Vascular endothelial growth factor (VEGF) is recognized a pivotal pro‐angiogenic factor responsible for new blood vessels formation in psoriatic lesion.

Objectives  The aim of the study was to analyse serum concentrations of VEGF and its soluble receptors (sVEGF) R1 and R2 in psoriatic patients before and after treatment.

Methods  Serum samples were collected before and after 14 days of standard topical therapy, from 44 patients with exacerbated chronic plaque‐type psoriasis and VEGF, sVEGF R1 and sVEGF R2 concentrations were measured using an enzyme immunoassay. Data were analysed with respect to baseline values of the psoriasis area severity index (PASI).

Results  Baseline mean serum levels of VEGF and sVEGF R1, but not sVEGF R2 were significantly higher in patients than in healthy controls. VEGF demonstrated significant correlation with PASI score. Treatment resulted in significant reduction of VEGF serum concentration, particularly in patients with severe course of the disease (PASI >20) and increase in sVEGF R1 concentration in patients with mild disease activity (PASI <10). Moreover, serum sVEGF R1 level after treatment termination was significantly higher in patients with mild than severe course of psoriasis.

Conclusions  We confirmed the association between psoriasis activity and serum VEGF concentrations, which can be recognized as an indicator of the disease severity. However, the increase of serum sVEGF R1 concentrations can predict amelioration of clinical signs.
Climatic modifiers of the response to nitrogen deposition in peat‐forming Sphagnum mosses: a meta‐analysis
Authors: Limpens J. , Granath G. , Gunnarsson U. , Aerts R. , Bayley S. , Bragazza L. , Bubier J. , Buttler A. , van den Berg L. J. L. , Francez A‐J. , Gerdol R. , Grosvernier P. , Heijmans M. M. P. D. , Hoosbeek M. R. , Hotes S. , Ilomets M. , Leith I. , Mitchell E. A. D. , Moore T. , Nilsson M. B. , Nordbakken J‐F. , Rochefort L. , Rydin H. , Sheppard L. J. , Thormann M. , Wiedermann M. M. , Williams B. L. , Xu B.
Published: March 2011

See also the Commentary by Dise and Phoenix
Psychosocial health in children and adolescents surviving cancer
Authors: Eilertsen Mary‐Elizabeth B. , Rannestad Toril , Indredavik Marit S. , Vik Torstein
Published: March 2011

Scand J Caring Sci; 2011; 25; 725–734

Psychosocial health in children and adolescents surviving cancer

Aim:  To explore psychosocial health in children and adolescents surviving cancer three years after diagnosis compared with healthy controls, as assessed by adolescents themselves, their parents and teacher.

Material and methods:  Case–control study included 50 children and adolescents diagnosed with cancer between 1 January 1993 and 1 January 2003 and treated at the Paediatric Department St. Olav’s University Hospital, Trondheim, Norway. Data were collected using the Strengths and Difficulties Questionnaire (self‐report, parent report and teacher report), as well as the Achenbach System of Empirically Based Assessment questionnaire (teacher report).

Results:  Children surviving cancer had more emotional symptoms, higher total problem scores and poorer academic performance than their peers. Emotional problems were consistently reported by parents, teachers and adolescents themselves, in particular in children with brain tumours and among survivors with late effects.

Conclusion:  Our study shows that children surviving cancer are at higher risk for emotional problems when compared with their friends, even after several years following diagnosis and treatment. We conclude that when planning long‐term follow‐up care, rehabilitation of children and adolescents with cancer, especially for survivors with brain tumours and late effects, should particularly take into account their psychological problems and psychosocial functioning.
Effects of tillage and crop rotation on chemical phosphorus forms and some related biological activities in a Chilean Ultisol
Authors: Redel Y. D. , Escudey M. , Alvear M. , Conrad J. , Borie F.
Published: March 2011

The effect of tillage systems and crop rotation on microbial biomass phosphorus (MBP) and acid phosphatase (P‐ase) activity, and the amount of different phosphorus (P) forms measured by 31P‐NMR spectroscopy were studied on a field experiment carried out in a temperate Ultisol from southern Chile. Two tillage systems, no tillage (NT) and conventional tillage (CT) and two crop rotations, oat–wheat (OW) and lupine–wheat (LW) were evaluated 4 yr after the start of the experiment to determine the effects of such management on some soil biological parameters and P forms at three depths (0–5, 0–10 and 10–20 cm). Microbial biomass P ranged from 6.5 to 22.6 mg/kg, whereas the mean total P (PT) was 1995 mg/kg for all treatments (OW and LW). Microbial biomass carbon (MBC) and surface P accumulation (at 0–5 cm depth), including Olsen P, MBP, orthophosphate monoesters (monoester‐P), were larger under NT than CT. Tillage effects were greater than crop rotation effects in enhancing P availability. The LW rotation showed enhanced P‐ase activity and increased monoester‐P forms (57 vs. 30% of the total integral area of the spectra, in average) compared with OW. Nevertheless, OW rotation increased orthophosphate (ortho‐P), especially at 10–20 cm. Microbial biomass carbon ranged from 532 to 2351 mg/kg, which represented 1.2–4.5% of total organic C (Co). Furthermore, MBP correlated positively with MBC (r = 0.80), Olsen P (r = 0.77), Co (r = 0.77), pH (r = 0.65), PT (r = 0.65) and P‐ase activity (r = 0.57), suggesting the importance of the microbial biomass on soil P availability.
Encephalopathy and SCN1A mutations
Authors: Tang Shan , Lin Jean Pierre , Hughes Elaine , Siddiqui Ata , Lim Ming , Lascelles Karine
Published: March 2011

We describe three children with genetically different sodium channel alpha 1 subunit (SCN1A) mutation associated epilepsy who experienced a sudden and sustained neurologic regression following status epilepticus in two and acute sepsis in one. Neuroimaging showed evidence of cerebral ischemia in one, but the other two cases showed cerebellar signal abnormalities. The selectivity of cerebellar white matter change suggests a different mechanism of injury or increased susceptibility of this brain region to injury in at least some patients with SCN1A mutations. This report adds to the spectrum and mechanism of acute neurologic deterioration and functional deficit associated with SCN1A mutations, which remains to be fully understood.
Modern antiepileptic drug development has failed to deliver: Ways out of the current dilemma
Authors: Löscher Wolfgang , Schmidt Dieter
Published: March 2011

Despite the development of various new antiepileptic drugs (AEDs) since the early 1990s, the available evidence indicates that the efficacy and tolerability of drug treatment of epilepsy has not substantially improved. What are the reasons for this apparent failure of modern AED development to discover drugs with higher efficacy? One reason is certainly the fact that, with few exceptions, all AEDs have been discovered by the same conventional animal models, particularly the maximal electroshock seizure test (MES) in rodents, which served as a critical gatekeeper. These tests have led to useful new AEDs, but obviously did not help developing AEDs with higher efficacy in as yet AED‐resistant patients. This concern is not new but, surprisingly, has largely been unappreciated for several decades. A second—admittedly speculative—reason is that progress in pharmacologic treatment of drug‐resistant epilepsy will not be made unless and until we develop drugs that specifically target the underlying disease. Although better preclinical approaches will not be able to circumvent regulatory requirements, more efficacious drugs may allow us to abandon clinically questionable trials with intentionally less efficacious controls and noninferiority designs, and require evidence for comparative effectiveness. The failure of AED development has led to increasing disappointment among clinicians, basic scientists, and industry and may halt any further improvement in the treatment of epilepsy unless we find ways out of this dilemma. Therefore, we need new concepts and fresh thinking about how to radically change and improve AED discovery and development. In this respect, the authors of this critical review will discuss several new ideas that may hopefully lead to more efficacious drug treatment of epilepsy in the future.
Did the Financial Crisis in Japan Affect Household Welfare Seriously?
Authors: SAWADA YASUYUKI , NAWATA KAZUMITSU , II MASAKO , LEE MARK J.
Published: March 2011

We investigate whether and how the credit crunch during the financial crisis in Japan affected household welfare. We estimate the consumption Euler equation with endogenous credit constraints using household panel data for 1993–99, generating several findings. First, a small but nonnegligible portion of the households faced credit constraints during the crisis, rejecting the standard consumption Euler equation. Second, the credit crunch affected household welfare negatively, albeit not seriously. The estimated welfare loss ranges between 2% to 10% increases in marginal utility, depending on income level. Finally, our results corroborate that the credit crunch in Japan was supply‐driven.
The Optimal Rate of Inflation with Trending Relative Prices
Authors: WOLMAN ALEXANDER L.
Published: March 2011

Relative price trends mean that monetary policy cannot stabilize the nominal prices of all consumption categories. If prices are sticky, monetary policy must then trade off distortions within different categories; more weight should be placed on stabilizing prices for which adjustment entails greater distortions. With exogenous price stickiness, a simple model calibrated to U.S. data implies that slight deflation is optimal even absent money‐demand considerations. If price stickiness is endogenous (because of fixed costs of adjustment), small inflation or small deflation can be optimal, depending on whether demand conditions or price adjustment costs vary across sectors.
Price Adjustments in a General Model of State‐Dependent Pricing
Authors: COSTAIN JAMES , NAKOV ANTON
Published: March 2011

We study the distribution of retail price adjustments under the assumption that firms are more likely to adjust their prices when doing so is more valuable. Our setup nests Calvo (1983) at one extreme and a fixed menu cost model at the other; all parameterizations are ranked by a measure of state dependence. High state dependence implies, counterfactually, that there are no small price changes and that the variance of price changes falls sharply with trend inflation. The parameterization that best fits microdata has low state dependence, implying a Phillips curve coefficient 60% as large as that of the Calvo model, but is nonetheless well behaved at high inflation rates.
Credit and the Natural Rate of Interest
Authors: DE FIORE FIORELLA , TRISTANI ORESTE
Published: March 2011

We analyze the properties of the natural rate of interest in an economy with asymmetric information between borrowers and lenders, and nominal debt contracts. In our model, monetary policy has real effects in the flexible‐price equilibrium because it affects the cost of external finance. As a consequence, under the standard definition, the natural rate of interest is not a useful policy indicator because it is itself affected by monetary policy. We propose a generalized definition and demonstrate that the resulting natural rate (i) is not policy dependent and (ii) delivers price stability if used as the intercept of a monetary policy rule. From a qualitative perspective, the dynamics of the natural rate in response to shocks can be very different in economies with or without financial frictions. Quantitatively, the policy implications of these differences tend to be minor for real shocks, but sizable for financial shocks of the magnitude observed during the financial crisis of 2007–09.
Small and Medium‐Sized Enterprises, Bank Relationship Strength, and the Use of Venture Capital
Authors: BERGER ALLEN N. , SCHAECK KLAUS
Published: March 2011

We investigate the nexus between small and medium‐sized enterprises’ (SMEs’) use of venture capital and bank financing relationships using a unique data set with detailed information on SME finance in Italy, Germany, and the UK. The empirical regularities we uncover show that that entrepreneurial firms substitute venture capital for multiple banking relationships. This substitution effect is primarily driven by expertise substitution, and there is also some suggestive, yet inconclusive, indication in the data that SMEs turn to providers of venture capital to avoid rent‐extracting behavior by the firm's main bank. Our results do not support the view that firms obtain venture capital in instances when bank financing is difficult to obtain. Instead, venture capital funds are used if bank funding is deemed not appropriate, and firms do seem to be aware of which type of financing is more appropriate for them.
Household Borrowing after Personal Bankruptcy
Authors: HAN SONG , LI GENG
Published: March 2011

A large body of literature has examined factors leading to filing for personal bankruptcy, but little is known about household borrowing after bankruptcy. This paper augments the existing literature with a comprehensive analysis of postbankruptcy borrowing using data from the Survey of Consumer Finances. We find that filers generally have more limited access to unsecured credit, but borrow more secured debt after bankruptcy, than comparable households that have never filed for bankruptcy. Filers also pay higher interest rates on all types of debt. In addition, as more time passes after filing, credit access and borrowing costs improve. However, filers remain more prone than comparable nonfilers to experience financial distress, accumulate less wealth, and use expensive credit sources like payday loans, even more than 10 years after filing.
Winners and Losers in Housing Markets
Authors: KIYOTAKI NOBUHIRO , MICHAELIDES ALEXANDER , NIKOLOV KALIN
Published: March 2011

This paper is a quantitatively oriented theoretical study into the interaction between housing prices, aggregate production, and household behavior over a lifetime. We develop a life‐cycle model of a production economy in which land and capital are used to build residential and commercial real estates. We find that in an economy where the share of land in the value of real estates is large, housing prices react more to an exogenous change in expected productivity or the world interest rate, causing a large redistribution between net buyers and net sellers of houses. Changing financing constraints, however, has limited effects on housing prices.
Rule‐of‐Thumb Consumers Meet Sticky Wages
Authors: COLCIAGO ANDREA
Published: March 2011

It has been argued that rule‐of‐thumb consumers substantially alter the determinacy properties of interest rate rules and the dynamics of an otherwise standard New Keynesian model. In this paper, we show that nominal‐wage stickiness helps to restore standard results. The key findings are that when wages are sticky: (i) the Taylor Principle is re‐established as the necessary condition for equilibrium determinacy, and (ii) consumption rises in response to an innovation in government spending if monetary policy is characterized by interest rate smoothing and by a moderately anti‐inflationary stance. Our results help to explain the reduction in the expansionary effects of fiscal shocks observed in the United States since 1980.
Immunohistochemical analysis of myenteric ganglia and interstitial cells of Cajal in ulcerative colitis
Authors: Bernardini Nunzia , Segnani Cristina , Ippolito Chiara , De Giorgio Roberto , Colucci Rocchina , Faussone‐Pellegrini Maria Simonetta , Chiarugi Massimo , Campani Daniela , Castagna Maura , Mattii Letizia , Blandizzi Corrado , Dolfi Amelio
Published: March 2011

Ulcerative colitis (UC) is an inflammatory bowel disease with alterations of colonic motility, which influence clinical symptoms. Although morpho‐functional abnormalities in the enteric nervous system have been suggested, in UC patients scarce attention has been paid to possible changes in the cells that control colonic motility, including myenteric neurons, glial cells and interstitial cells of Cajal (ICC). This study evaluated the neural‐glial components of myenteric ganglia and ICC in the colonic neuromuscular compartment of UC patients by quantitative immunohistochemical analysis. Full‐thickness archival samples of the left colon were collected from 10 patients with UC (5 males, 5 females; age range 45–62 years) who underwent elective bowel resection. The colonic neuromuscular compartment was evaluated immunohistochemically in paraffin cross‐sections. The distribution and number of neurons, glial cells and ICC were assessed by anti‐HuC/D, ‐S100β and ‐c‐Kit antibodies, respectively. Data were compared with findings on archival samples of normal left colon from 10 sex‐ and age‐matched control patients, who underwent surgery for uncomplicated colon cancer. Compared to controls, patients with UC showed: (i) reduced density of myenteric HuC/D+ neurons and S100β+ glial cells, with a loss over 61% and 38%, respectively, and increased glial cell/neuron ratio; (ii) ICC decrease in the whole neuromuscular compartment. The quantitative variations of myenteric neuro‐glial cells and ICC indicate considerable alterations of the colonic neuromuscular compartment in the setting of mucosal inflammation associated with UC, and provide a morphological basis for better understanding the motor abnormalities often observed in UC patients.
A limited role for regulatory T cells in post‐ischemic neovascularization
Authors: Hellingman A.A. , van der Vlugt L.E.P.M. , Lijkwan M.A. , Bastiaansen A.J.N.M. , Sparwasser T. , Smits H.H. , Hamming J.F. , Quax P.H.A.
Published: March 2011

Recently, it was demonstrated that arteriogenesis is enhanced in mice deficient in regulatory T cells (CD4+CD25+FoxP3+ T cell), which can suppress effector T cell responses. The present study investigates the effects of these regulatory T cells on arteriogenesis in more detail by either specific expanding or depleting regulatory T cells. Hind limb ischemia was induced by electro‐coagulation of the femoral artery in mice. Regulatory T cells were either expanded by injecting mice with a complex of interleukin (IL)‐2 with the IL‐2 monoclonal antibody JES6–1, or depleted by anti‐CD25 antibody or diphtheria toxin injections in DEREG mice (depletion of regulatory T cells). Blood flow restoration was monitored using laser Doppler perfusion imaging. Collateral arteries were visualized by immunohistochemistry. Regulatory T cell expansion led to a moderate though significant suppression of blood flow restoration after ischemia induction. Surprisingly, depletion of regulatory T cells resulted in minor increase on blood flow recovery. However, collateral and capillary densities in the post‐ischemic skeletal muscle were significantly increased in DEREG mice depleted for regulatory T cells. The presence of regulatory T cells after ischemia induction when analysed in non‐depleted DEREG mice could be demonstrated by green fluorescent protein staining only in lymph nodes in the ischemic area, and not in the ischemic muscle tissue. The current study demonstrates that, even under conditions of major changes in regulatory T cell content, the contribution of regulatory T cells to the regulation of the arteriogenic response is only moderate.
Bacteraemia with an unknown focus: is the focus de facto absent or merely unreported? A one‐year hospital‐based cohort study
Authors: LARSEN INGE KRISTINE , PEDERSEN GITTE , SCHØNHEYDER HENRIK C.
Published: March 2011

Larsen IK, Pedersen G, Schønheyder HC. Bacteraemia with an unknown focus: is the focus de facto absent or merely unreported? A one‐year hospital‐based cohort study. APMIS 2011; 119: 275–9.

An unknown focus of infection is associated with an increased risk of death in patients with bacteraemia. However, the implications for patient management remain uncertain, and to our knowledge, the validity of an unknown focus has not been evaluated. Therefore, we conducted a retrospective record review of bacteraemias with an unknown focus recorded in a regional bacteraemia database. The study cohort comprised 645 cases of bacteraemia diagnosed in 537 hospitalized patients at Aalborg Hospital, Denmark, in 2003. The focus was unknown in 184 (29%) bacteraemia episodes (162 patients). The record review pointed conclusively to a focus in 39 episodes. The positive predictive value of an unknown focus was 79% and the proportion of bacteraemias with a focus increased from 71% to 78%. Among the 145 cases of bacteraemia with a de facto unknown focus, there were 36 incidents of febrile neutropenia and 20 additional incidents of early death which precluded a search for a focus. The study confirmed the focus to be de facto absent in most patients classified with an unknown focus. The distribution of foci changed only marginally by the disclosure of a focus in one of five patients in the ‘unknown’ group.
Molecular and phenotypic characterization of Escherichia coli and Klebsiella pneumoniae producing extended‐spectrum β‐lactamases with focus on CTX‐M in a low‐endemic area in Sweden
Authors: ÖNNBERG ANNA , MÖLLING PAULA , ZIMMERMANN JOHANNA , SÖDERQUIST BO
Published: March 2011

Önnberg A, Mölling P, Zimmermann J, Söderquist B. Molecular and phenotypic characterization of Escherichia coli and Klebsiella pneumoniae producing extended‐spectrum β‐lactamases with focus on CTX‐M in a low‐endemic area in Sweden. APMIS 2011; 119: 287–95.

During the last decade increasing prevalence of extended‐spectrum β‐lactamase (ESBL)‐producing Enterobacteriaceae has been detected worldwide, mainly due to dissemination of Escherichia coli and Klebsiella pneumoniae producing CTX‐M‐type ESBLs. CTX‐M‐15 is the most widespread CTX‐M type, and the predominant type in various countries. Dissemination of ESBL‐producing organisms is caused not only by horizontal transfer of plasmids, but also by clonal spread of ESBL‐producing strains. In this study, the molecular epidemiology of class A ESBL (ESBLA)‐producing E. coli and K. pneumoniae isolated in Örebro County, Sweden, was investigated. Out of 200 ESBLA‐producing E. coli and K. pneumoniae isolates, collected over a 10‐year period, 87% were producing CTX‐M, belonging to subgroup CTX‐M‐1 (64%), CTX‐M‐9 (34%), or CTX‐M‐2 (2%). The remaining isolates were producing variants of SHV and TEM. Sequencing of the blaCTX‐M genes revealed 10 different CTX‐M types, with a dominance of CTX‐M‐15 (E. coli 54%, K. pneumoniae 50%) followed by CTX‐M‐14 (E. coli 28%, K. pneumoniae 27%). Phenotypic characterization of the CTX‐M‐producing isolates was performed using the PhenePlate system. Although a few minor clusters of CTX‐M‐15 and CTX‐M‐14 producers were identified, the majority of the isolates did not appear to be clonally related.
Student perceptions of syndicate learning: tutor‐less group work within an undergraduate dental curriculum
Authors: McKerlie R. A. , Cameron D. A. , Sherriff A. , Bovill C.
Published: March 2011

This paper describes the implementation of syndicate learning (tutor‐less group working) to teach the basic principles and skills of removable partial denture design within an undergraduate dental curriculum at the University of Glasgow. Student perceptions of syndicate group learning were collected through using questionnaires with Likert scales and through focus group interviews. The majority of students expressed positive views of syndicate learning that focused on the following themes: the added value of the group in terms of learning and in terms of social cohesion; the sense of responsibility to peers that led them to work harder; the autonomy of tutor‐less groups that led them to improve their ability to justify their work; and the effectiveness of the syndicate groups in comparison with other learning methods. On the basis of these findings along with reports from students that learning about group roles enhanced their preparation for future work, we argue that syndicate learning can offer some valuable benefits to the undergraduate dental curriculum.
Are island and mainland biotas different? Richness and level of generalism in parasitoids of a microlepidopteran in Macaronesia
Authors: Santos Ana M. C. , Fontaine Colin , Quicke Donald L. J. , Borges Paulo A. V. , Hortal Joaquín
Published: March 2011

Island communities are exposed to several evolutionary and ecological processes that lead to changes in their diversity and structure compared to mainland biotas. These phenomena have been observed for various taxa but not for parasitoids, a key group in terms of community diversity and functioning. Here we use the parasitoid communities associated with the mothAcroclita subsequana(Lepidoptera: Tortricidae) in the Macaronesian region, to test whether species richness differs between islands and mainland, and whether island parasitoid faunas are biased towards generalist species. Host larvae were collected on several islands and adjacent mainland, carefully searched for ectoparasitoid larvae and dissected to recover any endoparasitoids. Parasitoids were classified as idiobionts, which usually have a wide host range (i.e. generalists), or koinobionts that are considered specialists. Mainland species richness was lower than expected by chance, with most of the species being koinobionts. On the other hand, island communities showed a greater proportion of idiobiont species. Overall parasitism rates were similar between islands and mainland, but islands had higher rates of parasitism by idiobionts than expected by chance, and mainland areas showed the highest koinobiont parasitism rates. These results suggest that island parasitoid communities are dominated by generalists, in comparison to mainland communities. Several hypotheses may explain this pattern: (1) generalist parasitoids might have better dispersal abilities; (2) they may be less constrained by ‘sequential dependencies’; and (3) island parasitoids probably have fewer competitors and/or predators, thus favouring the establishment of generalists. New studies including multiple hosts, other habitats, and/or more islands are necessary to identify which of these processes shape island parasitoid communities.
Increased bumblebee abundance along the margins of a mass flowering crop: evidence for pollinator spill‐over
Authors: Hanley M. E. , Franco M. , Dean C. E. , Franklin E. L. , Harris H. R. , Haynes A. G. , Rapson S. R. , Rowse G. , Thomas K. C. , Waterhouse B. R. , Knight M. E.
Published: March 2011

Although the practice of cultivating mass flowering crops (MFCs) is seen as a means of counteracting the widespread decline of insect pollinators, no study to‐date has evaluated whether the increased pollinator abundance associated with MFCs influences pollinator visits to assemblages of adjacent native, non‐crop plant species (pollinator ‘spill‐over’). In this study we quantified bumblebee abundance along hedgerow transects in MFC (field bean) vs non‐MFC (wheat) margins. Surveys were conducted on east and west‐facing margins twice daily (morning and afternoon) for three or four days during the main MFC flowering period (June) over four years involving paired bean and wheat fields in Devon and Cornwall, southwest England. Although no single bumblebee species showed any consistent change in relative frequency, when taken across all years and bumblebee species combined, we observed twice as many bumblebees visiting flowers adjacent to the MFC. However, when we compared bumblebee activity along hedgerow transects two weeks after bean flowering, there was no difference between crops. We thus conclude that although there is evidence for pollinator spill‐over from the bean MFC to nearby semi‐natural habitat, the effect is comparatively short lived and not specific to any single bumblebee species. We also suggest that while pollinator services to native plant species might be briefly enhanced by MFC cultivation, the possible repercussions of bumblebee spill‐over from MFCs to semi‐natural habitats and the other pollinator groups they support should be evaluated before MFC cultivation is considered as a means of conserving declining bumblebee populations.
Pollinator attraction to volatiles from virgin and pollinated host flowers in a yucca/moth obligate mutualism
Authors: Svensson Glenn P. , Pellmyr Olle , Raguso Robert A.
Published: March 2011

The classic obligate pollination–seed consumption mutualism between yuccas and yucca moths has been thought to be mediated by chemical cues, but empirical data on pollinator attraction to host floral volatiles in this association have been lacking. Here we show that the scent from virgin flowers of the host Yucca glauca is sufficient to attract its obligate pollinator Tegeticula yuccasella in Y‐tube olfactometer tests. Interestingly, both sexes of moths were attracted to the scent stimulus. Because yucca moths mate inside host flowers, the attraction of both females and males to host floral volatiles is likely to increase encounter rates. In a second test, female moths did not discriminate between virgin and hand‐pollinated flowers, indicating no post‐pollination change in scent production by the host that would lead to a reduction in pollinator attraction and thereby limit exploitation of the available seeds in host flowers. However, other mechanisms that could stabilise the mutualism between T. yuccasella and its yucca hosts have already been documented, i.e. selective abortion of heavily infested flowers, and a female‐derived host‐marking pheromone. Headspace collection and GC–MS were used to identify the blend of floral volatiles emitted by Y. glauca, which was found to be very similar to those of two other allopatric capsular‐fruited species, Y. elata and Y. filamentosa, revealing strong conservation of this trait within Yucca section Chaenocarpa.
Breeding success at the range margin of a desert species: implications for a climate‐induced elevational shift
Authors: Hargrove Lori , Rotenberry John T.
Published: March 2011

If the breeding range of a species is limited by biotic or abiotic environmental factors that depress breeding success at the range margin, then range expansion is expected when those limiting factors are alleviated. Over a three‐year period, we measured breeding success of a desert species, black‐throated sparrowAmphispiza bilineata, along a steep elevation gradient between the Peninsular Mountains and Colorado Desert (San Diego County, California) that is undergoing a warming trend. We compared breeding success at geographically marginal locations (higher‐elevation chaparral sites) to more central locations (lower‐elevation desert scrub sites) only a short distance apart. Breeding success was measured at the nest level, territory level, and population level. At each level measured, breeding success tended to be greater at higher‐elevation chaparral sites at the distribution margin compared to lower‐elevation sites where the bird was more common. Black‐throated sparrows had 100% reproductive failure at lower‐elevation sites during the two driest years of our study (2006–2007), but did relatively well at higher‐elevation sites. Only in a wetter year (2008) was breeding success improved at lower‐elevation sites. Surprisingly, there was no evidence of an upward elevational shift in distribution over a 26‐year period despite a clear warming trend and drier conditions. Greater territory density at lower‐elevation sites with reproductive failure during dry years suggests the possibility of an ecological trap in this system, which could prevent or delay climate‐induced range shifts. A common presumption has been that desert species will undergo relatively mild negative impacts due to a warming climate, but it is possible that some desert species are already at or near their temperature and aridity tolerance limits within their current range and shifts may not always be possible.
Tradeoff between offspring mass and subsequent reproduction in a highly iteroparous mammal
Authors: Hamel Sandra , Côté Steeve D. , Festa‐Bianchet Marco
Published: March 2011

When resources are limited, current maternal investment should reduce subsequent reproductive success or survival. We used longitudinal data on marked mountain goats Oreamnos americanus to assess if offspring mass at weaning affected maternal survival and future reproduction. Offspring mass was positively correlated with survival of old mothers, suggesting that mothers produced lighter kids, and hence reduced reproductive effort, in their last reproduction. Offspring mass at weaning did not affect survival of young and prime‐aged mothers, but females that had weaned heavy offspring had a reduced probability of subsequent reproduction in years of low population density. Because offspring survival is correlated with weaning mass, mothers’ allocation to reproduction involves a tradeoff between current and future fitness returns. We demonstrate for the first time that allocation to current offspring mass in an iteroparous mammal reduces the probability of subsequent reproduction.
Interaction of the general transcription factor TnrA with the PII‐like protein GlnK and glutamine synthetase in Bacillus subtilis
Authors: Kayumov Airat , Heinrich Annette , Fedorova Kseniya , Ilinskaya Olga , Forchhammer Karl
Published: March 2011

TnrA is a master transcription factor regulating nitrogen metabolism in Bacillus subtilis under conditions of nitrogen limitation. When the preferred nitrogen source is in excess, feedback‐inhibited glutamine synthetase (GS) has been shown to bind TnrA and disable its activity. In cells grown with an energetically unfavorable nitrogen source such as nitrate, TnrA is fully membrane‐bound via a complex of AmtB and GlnK, which are the transmembrane ammonium transporter and its cognate regulator, respectively, originally termed NrgA and NrgB. The complete removal of nitrate from the medium leads to rapid degradation of TnrA in wild‐type cells. In contrast, in AmtB‐deficient or GlnK‐deficient strains, TnrA is neither membrane‐bound nor degraded in response to nitrate depletion. Here, we show that TnrA forms either a stable soluble complex with GlnK in the absence of AmtB, or constitutively binds to GS in the absence of GlnK. In vitro, the TnrA C‐terminus is responsible for interactions with either GS or GlnK, and this region appears also to mediate proteolysis, suggesting that binding of GlnK or GS protects TnrA from degradation. Surface plasmon resonance detection assays have demonstrated that GS binds to TnrA not only in its feedback‐inhibited form, but also in its non‐feedback‐inhibited form, although less efficiently. TnrA binding to GlnK or GS responds differentially to adenylate nucleotide levels, with ATP weakening interactions with both partners.

Structured digital abstract

tnrA
 binds to glnK by surface plasmon resonance (View interaction)

GS
 binds to tnrA by pull down (View interaction)

tnrA
 binds to glnK by pull down (View interaction)

tnrA
 binds to GS by pull down (View interaction)

GS
 physically interacts with tnrA by anti bait coimmunoprecipitation (View interaction)

glnK
 binds to tnrA by pull down (View interaction)

glnK
 physically interacts with tnrA by anti bait coimmunoprecipitation (View interaction)

tnrA
 physically interacts with GS by anti bait coimmunoprecipitation (View interaction)

tnrA
 physically interacts with glnK by anti bait coimmunoprecipitation (View interaction)

tnrA
 binds to tnrA by cross‐linking study (View interaction)

tnrA
 binds to GS by surface plasmon resonance (View interaction)