bluuebunny/crossref_metadata_2025 huggingface dataset:
A hierarchical Bayesian approach for estimation of photosynthetic parameters of C3plants
Authors: PATRICK LISA D. , OGLE KIONA , TISSUE DAVID T.
Published: August 2009

We describe a hierarchical Bayesian (HB) approach to fitting the Farquharet al.model of photosynthesis to leaf gas exchange data. We illustrate the utility of this approach for estimating photosynthetic parameters using data from desert shrubs. Unique to the HB method is its ability to simultaneously estimate plant‐ and species‐level parameters, adjust for peaked or non‐peaked temperature dependence of parameters, explicitly estimate the ‘critical’ intracellular [CO2] marking the transition between ribulose 1·5‐bisphosphate carboxylase/oxygenase (Rubisco) and ribulose‐1,5‐bisphosphate (RuBP) limitations, and use both light response and CO2response curve data to better inform parameter estimates. The model successfully predicted observed photosynthesis and yielded estimates of photosynthetic parameters and their uncertainty. The model with peaked temperature responses fit the data best, and inclusion of light response data improved estimates for day respiration (Rd). Species differed inRd25(Rdat 25 °C), maximum rate of electron transport (Jmax25), a Michaelis–Menten constant (Kc25) and a temperature dependence parameter (ΔS). Such differences could potentially reflect differential physiological adaptations to environmental variation. Plants differed inRd25,Jmax25, mesophyll conductance (gm25) and maximum rate of Rubisco carboxylation (Vcmax25). These results suggest that plant‐ and species‐level variation should be accounted for when applying the Farquharet al.model in an inferential or predictive framework.
PCR detection of Pseudoperonospora humuli in air samples from hop yards
Authors: Gent D. H. , Nelson M. E. , Farnsworth J. L. , Grove G. G.
Published: August 2009

Downy mildew of hop, caused by Pseudoperonospora humuli, is an important disease in most regions of hop production and is managed largely with regular fungicide applications. A PCR assay specific to P. humuli and the related organism P. cubensis was developed and used to monitor airborne inoculum in hop yards to initiate fungicide applications. The PCR amplified as little as 1 fg of genomic DNA of P. humuli, and yielded an amplicon in 70% of reactions when DNA was extracted from single sporangia. In the presence of 25 mg of soil, an amplicon was amplified in 90% of reactions when DNA was extracted from 10 or more sporangia. During nine location‐years of validation, PCR detection of the pathogen in air samples occurred no later than 8 days after the appearance of trace levels of disease signs and/or detection of airborne spores in a volumetric spore sampler. Inoculum was detected on average 4·5 days before (range −8 to 14 days) the first appearance of basal spikes in six commercial yards, or 1·3 days after (range −5 to 1 days) sporangia were detected in a volumetric spore sampler in experimental plots. In commercial yards, use of PCR to initiate the first fungicide application led to enhanced disease control or a reduction in fungicide use in four of six yards compared to growers’ standard practices. These results indicate that the efficiency and efficacy of hop downy mildew management can be improved when control measures are timed according to first detection of inoculum.
Relationship between wheat rust resistance genes Yr1 and Sr48 and a microsatellite marker
Authors: Bansal U. K. , Hayden M. J. , Keller B. , Wellings C. R. , Park R. F. , Bariana H. S.
Published: August 2009

A recombinant inbred line population derived from a cross between the winter wheat cultivars Arina and Forno was used to study the genetic relationship between genes Yr1 and SrAn1 in chromosome 2AL. Yr1 from Forno showed repulsion linkage (16·5 cM) with SrAn1 carried by Arina and was proximal to SrAn1. Based on the chromosomal location of SrAn1 with respect to Yr1 and its ineffectiveness against the Australian Puccinia graminis f. sp. tritici pathotype 34‐1,2,7 + Sr38, it was concluded that SrAn1 is distinct from Sr21 and was designated as Sr48. An attempt was made to map more markers in the distal region of chromosome 2AL in order to determine the precise location of Sr48. Unfortunately none of the markers tested mapped between Yr1 and Sr48, with the latter being the most distal locus. However, close linkage was identified between Yr1 and the PCR‐based molecular marker stm673acag. Genotyping with stm673acag amplified a 120‐bp fragment in eight of nine genotypes carrying Yr1. Avocet S was the only line tested without Yr1 that also amplified the 120‐bp product. A 124‐bp product was amplified in 40 Australian wheat cultivars known to lack Yr1. These results suggest that stm673acag could be used for marker assisted selection of Yr1. Genotypes carrying both Yr1 and Sr48 were identified.
SYNGAP: bridging the gap between genetic factors and autosomal non‐syndromic mental retardation
Authors: Huang K
Published: August 2009

M/S: mutations in SYNGAP1 in autosomal non‐syndromic mental retardation

Hamdan et al. (2009)

The New England Journal of Medicine 360: 599–605
The effect of low‐carbohydrate diet on left ventricular diastolic function in obese children
Authors: Zeybek Cenap , Celebi Ahmet , Aktuglu‐Zeybek Cigdem , Onal Hasan , Yalcin Yalim , Erdem Abdullah , Akdeniz Celal , Imanov Elnur , Altay Suheyla , Aydın Ahmet
Published: August 2009

Background:  This study was conducted to evaluate left ventricle (LV) functions using conventional and tissue Doppler imaging in childhood obesity and to identify the effects of diet on LV diastolic functions.

Methods:  Conventional and tissue Doppler echocardiographic measurements were compared in 34 obese children and 24 age‐ and gender‐matched lean controls. Fasting plasma glucose, insulin and homeostatic model assessment of insulin resistance levels were also obtained. Thirty‐one of the obese children were subjected to a low‐carbohydrate diet and their follow‐up measurements were obtained after 6 months.

Results:  Left atrial diameter, LV mass and LV mass index were higher in obese children than in lean controls. Lateral mitral myocardial early diastolic (Em) and peak Em/myocardial late diastolic (Am) were lower, and mitral E/Em and lateral mitral myocardial isovolumetric relaxation time were higher in obese subjects than in lean controls. Insulin and homeostatic model assessment of insulin resistance levels were higher in obese patients and decreased significantly after diet. After diet therapy, lateral mitral Em and peak Em/Am, were increased, mitral E/Em and myocardial isovolumetric relaxation time were decreased.

Conclusions:  Obesity predisposes children to increased preload reserve, left ventricular subclinical diastolic dysfunction and deterioration in diastolic filling. Weight reduction with a low‐carbohydrate diet seems to be associated with significant improvement in LV diastolic function and a decrease in diastolic filling, as well as causing reversal in insulin resistance seen in obese children.
Nucleus accumbens neurons exhibit synaptic scaling that is occluded by repeated dopamine pre‐exposure
Authors: Sun Xiu , Wolf Marina E.
Published: August 2009

Synaptic scaling has been proposed as a form of plasticity that may contribute to drug addiction but it has not been previously demonstrated in the nucleus accumbens (NAc), a critical region for addiction. Here we demonstrate bidirectional synaptic scaling in postnatal rat NAc neurons that were co‐cultured with prefrontal cortical neurons to restore excitatory input. Prolonged activity blockade (1–3 days) with an AMPA receptor antagonist increased cell surface (synaptic and extrasynaptic) glutamate receptor 1 (GluR1) and GluR2 but not GluR3, as well as GluR1/2 co‐localization on the cell surface and total GluR1 and GluR2 protein levels. A prolonged increase in activity (bicuculline, 48 h) produced opposite effects. These results suggest that GluR1/2‐containing AMPA receptors undergo synaptic scaling in NAc neurons. GluR1 and GluR2 surface expression was also increased by tetrodotoxin alone or in combination with anN‐methyl‐d‐aspartate receptor or AMPA receptor antagonist but not by thel‐type Ca2+channel antagonist nifedipine. A cobalt‐quenching assay confirmed the immunocytochemical results indicating that synaptic scaling after activity blockade did not involve a change in abundance of GluR2‐lacking AMPA receptors. Increased AMPA receptor surface expression after activity blockade required protein synthesis and was occluded by inhibition of the ubiquitin‐proteasome system. Repeated dopamine (DA) treatment, which leads to upregulation of surface GluR1 and GluR2, occluded activity blockade‐induced synaptic scaling. These latter results indicate an interaction between cellular mechanisms involved in synaptic scaling and adaptive mechanisms triggered by repeated DA receptor stimulation, suggesting that synaptic scaling may not function normally after exposure to DA‐releasing drugs such as cocaine.
GABA release from cerebellar stellate cells is developmentally regulated by presynaptic GABAB receptors in a target‐cell‐specific manner
Authors: Astori Simone , Luján Rafael , Köhr Georg
Published: August 2009

Transmitter release from boutons along a common axon is often regulated depending on the postsynaptic target. Here, GABA release from cerebellar stellate cells onto Purkinje cells and other stellate cells was examined in acute cerebellar slices of 2‐ and 4‐week‐old mice. Consistent with previous findings on action potential‐dependent GABA release, we found a developmental decrease in inhibitory inputs onto Purkinje cells but not onto stellate cells when recording miniature inhibitory postsynaptic currents (mIPSCs). Although amplitudes of mIPSCs were developmentally reduced in both cell types, mIPSC frequencies were decreased in Purkinje cells but were increased in stellate cells. Similarly, modulation of GABA release by presynaptic GABAB receptors changed during development in Purkinje cells but not in stellate cells, as demonstrated by the baclofen‐mediated depression of mIPSC frequency and evoked IPSC (eIPSC) amplitudes. The selectively diminished baclofen effect in 4‐week‐old Purkinje cells correlated with a selective downregulation of presynaptic GABAB receptors at stellate cell‐to‐Purkinje cell synapses observed by immunoelectron microscopy analysis. Thus, expression of GABAB receptors in stellate cell axons and presynaptic modulation of GABA release appear to change during development in a target‐cell‐specific manner.
3D surface perception from motion involves a temporal–parietal network
Authors: Beer Anton L. , Watanabe Takeo , Ni Rui , Sasaki Yuka , Andersen George J.
Published: August 2009

Previous research has suggested that three‐dimensional (3D) structure‐from‐motion (SFM) perception in humans involves several motion‐sensitive occipital and parietal brain areas. By contrast, SFM perception in nonhuman primates seems to involve the temporal lobe including areas MT, MST and FST. The present functional magnetic resonance imaging study compared several motion‐sensitive regions of interest including the superior temporal sulcus (STS) while human observers viewed horizontally moving dots that defined either a 3D corrugated surface or a 3D random volume. Low‐level stimulus features such as dot density and velocity vectors as well as attention were tightly controlled. Consistent with previous research we found that 3D corrugated surfaces elicited stronger responses than random motion in occipital and parietal brain areas including area V3A, the ventral and dorsal intraparietal sulcus, the lateral occipital sulcus and the fusiform gyrus. Additionally, 3D corrugated surfaces elicited stronger activity in area MT and the STS but not in area MST. Brain activity in the STS but not in area MT correlated with interindividual differences in 3D surface perception. Our findings suggest that area MT is involved in the analysis of optic flow patterns such as speed gradients and that the STS in humans plays a greater role in the analysis of 3D SFM than previously thought.
RESEARCH SECTION: School attendance and attainment: poor attenders' perceptions of schoolwork and parental involvement in their education
Authors: Sheppard Anne
Published: August 2009

Because of established links with attainment, the UK government has, over the last ten years, developed policies to improve school attendance. Legislation now makes school attendance a parental responsibility. In the small‐scale study reported in this article, Anne Sheppard, manager of an Education Welfare Service Team in North Yorkshire, collected data on 57 pupils' attitudes to school and schoolwork and their perceptions of their parents' involvement in their education. In order to examine the role of these variables in relation to school attendance, ‘good’ and ‘poor’ attenders of 12 to 13 years of age, matched for ability, were compared on a number of quantifiable measures regarding their perceptions of schoolwork and their parents' behaviour in relation to aspects of their schooling. Both good and poor attenders avoided class work if possible, but good attenders were more likely to do their homework and perceived their parents as more involved in their education. Anne Sheppard argues that Education Social Welfare Services need to take account of findings from parental involvement research in their practice if they are to increase both children's school attendance and attainment.
RESEARCH SECTION: Transition partnerships: the views of education professionals and staff in support services for young people with learning disabilities
Authors: Kaehne Axel , Beyer Stephen
Published: August 2009

Transition to post‐statutory education and employment for young people with learning disabilities has become a hotly debated issue among professionals in education and support services in the UK. Partnerships between educational institutions and voluntary sector providers are supposed to be ideal vehicles for delivering transition services and securing outcomes for young people with learning disabilities. In this article, Axel Kaehne and Stephen Bayer of the Welsh Centre for Learning Difficulties report the findings of a survey of the views of special educational needs co‐ordinators and professionals who are involved at operational and strategic levels in the work of transition partnerships. The data show that undue emphasis is often placed, by all stakeholders, on the soft, rather than the concrete, outcomes of transition; that smooth transitions are still hampered by insufficient flow of information between collaborating agencies; and that there are still significant gaps in provision, in particular in the supported employment field, due to funding or referral restrictions. To deliver first‐class transitions, argue Axel Kaehne and Stephen Bayer, partnerships that support young people with learning disabilities need to address these difficulties with some urgency.
TEACHER EDUCATION: Reflections upon teacher education in severe difficulties in the USA: shared concerns about quantity and quality
Authors: Jones Phyllis , West Elizabeth
Published: August 2009

In this article, Phyllis Jones of the Department of Special Education at the University of South Florida and Elizabeth West from the University of Washington explore key issues in respect to teacher education for teachers who teach pupils with severe and profound learning difficulties in the USA. Issues relating to quantity and quality of teachers are discussed in the context of policy and practice in the USA. Reflections related to teacher education delivery in the USA, in terms of case‐based learning and distance education, for example, and the content of teacher education courses, for example, in terms of helping teachers to understand the needs of pupils with learning difficulties and the promotion of evidence‐based practices, are discussed. Phyllis Jones and Elizabeth West suggest that their reflections can contribute to continuing discussions about teacher education in the UK for teachers who work with pupils with severe and profound learning difficulties.
Think or Sink: Chinese Learners' Acquisition of the English Voiceless Interdental Fricative
Authors: Rau D. Victoria , Chang Hui‐Huan Ann , Tarone Elaine E.
Published: August 2009

This study investigates the production of the English interdental fricative [θ] by Chinese learners of English, using a variationist framework. Twenty‐seven Chinese participants were asked to evaluate the acceptability of four possible substitutes for the variable (th) and to perform four oral production tasks. The results indicated that immediate phonetic environment and speech style accounted for the accurate production of [θ]. Learners who had good control over the pronunciation of [θ] used monitoring strategies, whereas those who had lower production accuracy depended on phonetic salience strategies. Lexical frequency slightly facilitated accurate production of [θ]. In addition, speakers from both Taiwan and China rated [s] as the most acceptable substitute for (th), confirming that they make up a single English‐as‐a‐foreign‐language speech community.
L2 Vocabulary Acquisition in Children: Effects of Learning Method and Cognate Status
Authors: Tonzar Claudio , Lotto Lorella , Job Remo
Published: August 2009

In this study we investigated the effects of two learning methods (picture‐ or word‐mediated learning) and of word status (cognates vs. noncognates) on the vocabulary acquisition of two foreign languages: English and German. We examined children from fourth and eighth grades in a school setting. After a learning phase during which L2 words were presented either together with the corresponding translation in L1 (word‐learning method) or with the picture of the object to which the word refers (picture‐learning method), children were tested at different points in time. The results showed that the picture‐based method leads to a better performance than the word‐based method, but this effect was modulated by cognate status and age of learning. On the one hand, cognates were found to facilitate the acquisition of L2 words, but when the language was familiar (i.e., English for the eighth‐grade children), this effect decreased with exposure to language. On the other hand, cognate status interacted with the learning method in the older children, indicating that the word method was particularly effective for cognate words. Some implications concerning learning two languages at a time in the school setting are discussed.
English L1 and L2 Speakers' Knowledge of Lexical Bundles
Authors: Nekrasova Tatiana M.
Published: August 2009

The purpose of the present study is to contribute to the ongoing debate about the use of lexical bundles by first (L1) and second language (L2) speakers of English. The study consists of two experiments that examined whether L1 and L2 English speakers displayed any knowledge of lexical bundles as holistic units and whether their knowledge was affected by the discourse function of the lexical bundles (discourse‐organizing or referential). The participants in Experiment 1 (N = 61) completed a gap‐filling activity, whereas the participants in Experiment 2 (N = 61) carried out a dictation task. Results showed that the participants' knowledge differed for specific lexical bundles and that, overall, they knew more discourse‐organizing bundles than referential bundles. The implications of the study are discussed in terms of current research about the role of frequency‐based language chunks in L1 and L2 speech processing in English.
Maturational Constraints and First Language Attrition
Authors: Bylund Emanuel
Published: August 2009

The aim of the article is to examine how first language attrition research on maturational constraints interprets and links its findings to current views on maturation in the field of second language acquisition. It is argued that attrition research exhibits certain inconsistencies in the interpretation of the structural characteristics of the critical period and the interplay between maturation and nonmaturational factors in attrition. In view of findings from first language relearning/reactivation and theoretical‐methodological advances in second language research on maturation, the article proposes a reinterpretation of maturational constraints in language attrition that, first, emphasizes the gradual decline of susceptibility to attrition and, second, puts forth the conditioning function that the maturational constraints have on nonmaturational factors.
What works best when? The role of active labour market policy programmes in different business cycles
Authors: Nordlund Madelene
Published: August 2009

Nordlund M. What works best when? The role of active labour market policy programmes in different business cycles

Int J Soc Welfare 2011: 20: 43–54 © 2009 The Author, Journal compilation © 2009 Blackwell Publishing Ltd and the International Journal of Social Welfare.

At what point in a business cycle do long‐term unemployed persons gain most from participation in active labour market policy programmes (ALMP) as compared with openly unemployed persons? This article studies this question from the perspective of individual human capital with the hazard of labour market exit and chances of future labour market stability and equal post‐unemployment income as output variables. All the long‐term unemployed in Sweden were followed on a four‐year basis, with 1993 (recession) and 1999 (boom) as starting years. The study shows mainly positive effects among participants regardless of the state of the market. However, ALMP training has a ‘bridging’ effect over different labour market conditions, and a quick return to the regular labour market is, therefore, not as important for the success of participation as it is among ALMP employment participants.
The integration of digestion and osmoregulation in the avian gut
Authors: McWhorter Todd J. , Caviedes‐Vidal Enrique , Karasov William H.
Published: August 2009

We review digestion and osmoregulation in the avian gut, with an emphasis on the ways these different functions might interact to support or constrain each other and the ways they support the functioning of the whole animal in its natural environment. Differences between birds and other vertebrates are highlighted because these differences may make birds excellent models for study and may suggest interesting directions for future research. At a given body size birds, compared with mammals, tend to eat more food but have less small intestine and retain food in their gastrointestinal tract (GIT) for shorter periods of time, despite generally higher mass‐specific energy demands. On most foods, however, they are not less efficient at digestion, which begs the question how they compensate. Intestinal tissue‐specific rates of enzymatic breakdown of substrates and rates of active transport do not appear higher in birds than in mammals, nor is there a demonstrated difference in the extent to which those rates can be modulated during acclimation to different feeding regimes (e.g. diet, relative intake level). One compensation appears to be more extensive reliance on passive nutrient absorption by the paracellular pathway, because the avian species studied so far exceed the mammalian species by a factor of at least two‐ to threefold in this regard. Undigested residues reach the hindgut, but there is little evidence that most wild birds recover microbial metabolites of nutritional significance (essential amino acids and vitamins) by re‐ingestion of faeces, in contrast to many hindgut fermenting mammals and possibly poultry. In birds, there is some evidence for hindgut capacity to breakdown either microbial protein or protein that escapes the small intestine intact, freeing up essential amino acids, and there is considerable evidence for an amino acid absorptive capacity in the hindgut of both avian and mammalian hindgut fermenters. Birds, unlike mammals, do not excrete hyperosmotic urine (i.e. more than five times plasma osmotic concentration). Urine is mixed with digesta rather than directly eliminated, and so the avian gut plays a relatively more important role in water and salt regulation than in mammals. Responses to dehydration and high‐ and low‐salt loads are reviewed. Intestinal absorption of ingested water is modulated to help achieve water balance in one species studied (a nectar‐feeding sunbird), the first demonstration of this in any terrestrial vertebrate. In many wild avian species the size and digestive capacity of the GIT is increased or decreased by as much as 50% in response to nutritional challenges such as hyperphagia, food restriction or fasting. The coincident impacts of these changes on osmoregulatory or immune function of the gut are poorly understood.
Leptin increases growth of primary ossification centers in fetal mice
Authors: Bertoni Laura , Ferretti Marzia , Cavani Francesco , Zavatti Manuela , Resca Elisa , Benelli Augusta , Palumbo Carla
Published: August 2009

The effect of peripheral leptin on fetal primary ossification centers during the early phases of bone histogenesis was investigated by administration of leptin to pregnant mice. Fourteen pregnant mice were divided into two groups. The treated pregnant group was subcutaneously injected in the intrascapular region with supraphysiologic doses (2 mg kg−1) of leptin (Vinci Biochem, Firenze, Italy) in a volume of 0.1 mL per 10 g body weight, at the 7th, 9th and 11th day of gestation. The control group was treated with physiological solution in the same manner and same times as the treated group. The new‐born mice were killed 1 day after birth and the primary ossification centers were stained with Alizarin Red S after diaphanizing the soft tissues in 1% potassium hydroxide. The development of both endochondral and intramembranous ossification centers was morphometrically analysed in long bones. The results showed that the ossification centers of mice born by mothers treated with leptin grow more rapidly in both length and cross‐sectional area compared with mice born by the untreated mothers. As the development of long bones depends on endochondral ossification occurring at proximal and distal epiphyseal plates as well as on intramembranous ossification along the periosteal surface, it appears that leptin activates the differentiation and proliferation of both chondrocytes and osteoblasts. The role of leptin as a growth factor of cartilage and bone is discussed in the light of the data reported in the literature.
The efficacy of end‐to‐end and end‐to‐side nerve repair (neurorrhaphy) in the rat brachial plexus
Authors: Liao Wen‐Chieh , Chen Jeng‐Rung , Wang Yueh‐Jan , Tseng Guo‐Fang
Published: August 2009

Proximal nerve injury often requires nerve transfer to restore function. Here we evaluated the efficacy of end‐to‐end and end‐to‐side neurorrhaphy of rat musculocutaneous nerve, the recipient, to ulnar nerve, the donor. The donor was transected for end‐to‐end, while an epineurial window was exposed for end‐to‐side neurorrhaphy. Retrograde tracing showed that 70% donor motor and sensory neurons grew into the recipient 3 months following end‐to‐end neurorrhaphy compared to 40–50% at 6 months following end‐to‐side neurorrhaphy. In end‐to‐end neurorrhaphy, regenerating axons appeared as thick fibers which regained diameters comparable to those of controls in 3–4 months. However, end‐to‐side neurorrhaphy induced slow sprouting fibers of mostly thin collaterals that barely approached control diameters by 6 months. The motor end plates regained their control density at 4 months following end‐to‐end but remained low 6 months following end‐to‐side neurorrhaphy. The short‐latency compound muscle action potential, typical of that of control, was readily restored following end‐to‐end neurorrhaphy. End‐to‐side neurorrhaphy had low amplitude and wide‐ranging latency at 4 months and failed to regain control sizes by 6 months. Grooming test recovered successfully at 3 and 6 months following end‐to‐end and end‐to‐side neurorrhaphy, respectively, suggesting that powerful muscle was not required. In short, both neurorrhaphies resulted in functional recovery but end‐to‐end neurorrhaphy was quicker and better, albeit at the expense of donor function. End‐to‐side neurorrhaphy supplemented with factors to overcome the slow collateral sprouting and weak motor recovery may warrant further exploration.
Enhanced long‐term recollection for emotional pictures: Evidence from high‐density ERPs
Authors: Weymar Mathias , Löw Andreas , Melzig Christiane A. , Hamm Alfons O.
Published: August 2009

The present study used behavioral and electrophysiological measures to investigate the processes mediating long‐term recognition memory for emotional and neutral pictures. The results show enhanced memory recollection for emotional arousing pictures compared to neutral low arousing pictures. In accordance with the behavioral data, we observed enhanced old/new effects in the ERPs for emotionally arousing pictures in the recollection‐sensitive old/new component at centro‐parietal sites (500–800 ms). Moreover, early old/new effects were present over frontal and parietal sites (300–500 ms) irrespective of picture contents. Analysis of the subjective awareness, indexed by the confidence ratings, showed that the late parietal old/new effect was increased for high confidence responses whereas the early component (300–500 ms) was mainly driven by low confidence responses, an indication for familiarity based recognition processes.
Effects of prior stimulus and prior perception on neural correlates of auditory stream segregation
Authors: Snyder Joel S. , Holder W. Trent , Weintraub David M. , Carter Olivia L. , Alain Claude
Published: August 2009

We examined whether effects of prior experience are mediated by distinct brain processes from those processing current stimulus features. We recorded event‐related potentials (ERPs) during an auditory stream segregation task that presented an adaptation sequence with a small, intermediate, or large frequency separation between low and high tones (Δf), followed by a test sequence with intermediate Δf. Perception of two streams during the test was facilitated by small prior Δf and by prior perception of two streams and was accompanied by more positive ERPs. The scalp topography of these perception‐related changes in ERPs was different from that observed for ERP modulations due to increasing the current Δf. These results reveal complex interactions between stimulus‐driven activity and temporal‐context‐based processes and suggest a complex set of brain areas involved in modulating perception based on current and previous experience.
Customer satisfaction with apartment housing offered by Real Estate Investment Trusts (REITs)
Authors: James III Russell
Published: August 2009

The explosive growth of Real Estate Investment Trusts (REITs) is changing the ownership structure of rental housing in the US and across the world. This paper reports the impact of REIT ownership on renter satisfaction by analysing nearly one‐half million ratings posted on the largest US consumer comment website for apartments. Descriptive statistics and ordered logit analyses (both with and without zip code fixed effects) indicated that REITs following an aggressive branding strategy had positive effects on residential satisfaction, while non‐branding REITs had negative effects. This dichotomous outcome is consistent with an asymmetric‐information model of consumer choice in apartment rentals.
Objective measures as a predictor of late payments by high‐risk borrowers
Authors: Kolodinsky Jane M. , Roche Erin
Published: August 2009

Manufactured homes (also known outside the US as prefabricated homes) are a viable housing option for low‐income buyers, but traditional mortgages are not available for purchase of manufactured homes because of a perception of higher risk of default among purchasers of manufactured homes. Research suggests that creditscoring models which incorporate objective data such as income, debt‐to‐income ratio and credit history result in an accurate and objective predictive tool to estimate likelihood of late payments and default among traditional home buyers. This study showed that these same models can be applied similarly to purchasers of manufactured homes. A Tobit model was developed to evaluate which factors most accurately predict default and late payment behaviour among borrowers who purchased a manufactured home. The model showed that when decomposed into the probability of making a late payment and number of late payments, credit score and income are both significant predictors in both sets of borrowers of both the probability of making a late payment and the number of late payments. The higher the credit score, the less likely the borrower is to make a late payment.
Aesthetics in displacement – Hmong, Somali and Mexican home‐making practices in Minnesota
Authors: Hadjiyanni Tasoulla
Published: August 2009

Personalizing a residential environment has long been recognized among the dimensions of home. Little research though has focused on understanding the home‐making process of aesthetic construction under conditions of displacement. Questions still abound: What does the notion of aesthetics entail in displacement? Do immigrant groups construct a sense ofdifferencein the home, and if so, how? And, what can impede their efforts? Answering these questions sheds light on the opportunities that arise when interdisciplinary connections between architectural, housing and consumer studies are formed.

Using data from in‐depth interviews conducted in the homes of three displaced groups now living in Minnesota (Hmong, Somali and Mexicans), this paper explores the above questions and proposes theoretical and practical directions for supporting diverse housing needs. Delving into the living and socializing areas, the discussion uncovers the material and immaterial forms that aesthetic constructions can take: from decorative objects to colours, textures, materials, light levels, furniture placement and type as well as sound and smell. Interviewees varied in the number of cultural expressions they employed and degree to which they invested time, energy and funds to personalize their homes. Their efforts though were often purposive: a means to connect to a homeland, pass down one's cultural traditions to future generations, foster alliances with others from the same cultural group and a form of constructingdifference.

Particularly insightful are the impediments those interviewed endured in constructing an aesthetic they resonated with. Factors like spatiality, religious beliefs, regulations, income limitations, construction norms and availability of objects to purchase often suppressed their attempts to transform the spaces they lived in into places they can relate to, threatening in the process the group's cultural identity definition and creating stress in their lives. Given that home‐making is found to be inextricably tied to consumer studies through behaviours like purchasing products, the paper closes with the implications of rethinking aesthetics as well as directions for future research.
Modes of production in home maintenance: accounting for the choice between formality, off the books and self‐provisioning
Authors: Adriaenssens Stef , Hendrickx Jef
Published: August 2009

Households depend on the existence of a home, and therefore, maintenance plays an important social and economic role. Formal outsourcing is often overestimated here and alternative modes, such as informal outsourcing and do‐it‐yourself (DIY), are overlooked. This paper estimates and accounts for the choice of one mode of production in Flemish households.

First, the different modes of production are quantified according to two different methods. Further, an explanation of the choice made is constructed. The complexity of maintenance work has an impact as well as the dimensions of social and cultural capital. Factors such as dexterity, occupational acquaintance with maintenance work, social trust and social contacts play a role. Finally, a model of a sequence of decisions is tested. This ramification mechanism shows that the primary choice is formal commissioning or not, inspired by technical complexity. The second choice between off‐the‐books outsourcing and DIY is influenced by the capital resources of the households.
The negative inotropic action of canrenone is mediated by L‐type calcium current blockade and reduced intracellular calcium transients
Authors: Costa AR , Torres LB , Medei E , Ricardo RA , França JP , Smaili S , Nascimento JHM , Oshiro MEM , Bassani JWM , Ferreira AT , Tucci PJF
Published: August 2009

Background and purpose: Adding spironolactone to standard therapy in heart failure reduces morbidity and mortality, but the underlying mechanisms are not fully understood. We analysed the effect of canrenone, the major active metabolite of spironolactone, on myocardial contractility and intracellular calcium homeostasis.

Experimental approach: Left ventricular papillary muscles and cardiomyocytes were isolated from male Wistar rats. Contractility of papillary muscles was assessed with force transducers, Ca2+transients by fluorescence and Ca2+fluxes by electrophysiological techniques.

Key results: Canrenone (300–600 µmol·L−1) reduced developed tension, maximum rate of tension increase and maximum rate of tension decay of papillary muscles. In cardiomyocytes, canrenone (50 µmol·L−1) reduced cell shortening and L‐type Ca2+channel current, whereas steady‐state activation and inactivation, and reactivation curves were unchanged. Canrenone also decreased the Ca2+content of the sarcoplasmic reticulum, intracellular Ca2+transient amplitude and intracellular diastolic Ca2+concentration. However, the time course of [Ca2+]idecline during transients evoked by caffeine was not affected by canrenone.

Conclusion and implications: Canrenone reduced L‐type Ca2+channel current, amplitude of intracellular Ca2+transients and Ca2+content of sarcoplasmic reticulum in cardiomyocytes. These changes are likely to underlie the negative inotropic effect of canrenone.
Dog left ventricular midmyocardial myocytes for assessment of drug‐induced delayed repolarization: short‐term variability and proarrhythmic potential
Authors: Abi‐Gerges Najah , Valentin Jean‐Pierre , Pollard Chris E
Published: August 2009

Background and purpose: Evaluation of the potential for delayed ventricular repolarization and proarrhythmia by new drugs is essential. We investigated if dog left ventricular midmyocardial myocytes (LVMMs) that can be used as a preclinical model to assess drug effects on action potential duration (APD) and whether in these cells, short‐term variability (STV) or triangulation could predict proarrhythmic potential.

Experimental approach: Beagle LVMMs and Purkinje fibres (PFs) were used to record APs. Effects of six reference drugs were assessed on APD at 50% (APD50) and 90% (APD90) of repolarization, STV(APD), triangulation (ratio APD90/APD50) and incidence of early afterdepolarizations (EADs) at 1 and 0.5 Hz.

Key results: LVMMs provided stable recordings of AP, which were not affected by four sequential additions of dimethyl sulphoxide. Effects of dofetilide, d‐sotalol, cisapride, pinacidil and diltiazem, but not of terfenadine, on APD in LVMMs were found to be comparable with those recorded in PFs. LVMMs, but not PFs, exhibited a proarrhythmic response toIKrblockers. Incidence of EADs was not related to differences in AP prolongation or triangulation, but corresponded to beat‐to‐beat variability of repolarization, here quantified as STV of APD.

Conclusions and implications: LVMMs provide a suitable preclinical model to assess the effects of new drugs on APD and also yield additional information about putative indicators of proarrhythmia that add value to an integrated QT/TdP risk assessment. Our findings support the concept that increased STV(APD) may predict drug‐induced proarrhythmia.

This article is part of a themed section on QT safety. To view this issue visithttp://www3.interscience.wiley.com/journal/121548564/issueyear?year=2010
Metabolic characteristics of imatinib resistance in chronic myeloid leukaemia cells
Authors: Klawitter Jelena , Kominsky Douglas J , Brown Jaimi L , Klawitter Jost , Christians Uwe , Leibfritz Dieter , Melo Junia V , Eckhardt S Gail , Serkova Natalie J
Published: August 2009

Background and purpose: Early detection of resistance development is crucial for imatinib‐based treatment in chronic myeloid leukaemia (CML) patients. We aimed to distinguish metabolic markers of cell resistance to imatinib.

Experimental approach: Two human imatinib‐sensitive CML cell lines: LAMA84‐s and K562‐s, and their resistant counterparts: LAMA84‐r and K562‐r (both resistant to 1 µM imatinib), and K562‐R (5 µM) were analysed by nuclear magnetic resonance spectroscopy to assess global metabolic profiling, including energy state, glucose and phospholipid metabolism.

Key results: We found, by Western blotting and flow cytometry, that the levels of Bcr‐Abl tyrosine kinase and multi‐drug resistance p‐glycoprotein were inconsistent among resistant clones. On the other hand, phospholipid metabolism and lactate production were highly predictive for cell response to imatinib. As previously reported, sensitive cells showed significantly decreased glycolytic activity (lactate) and phospholipid synthesis (phosphocholine) as well as increased phospholipid catabolism (glycerophosphocholine) after 24 h of 1 µM imatinib treatment, which correlated with inhibition of cell proliferation and induction of apoptosis. In contrast to their sensitive counterparts, the K562‐r, K562‐R and LAMA84‐r maintained increased phospholipid synthesis and glycolytic lactate production in the presence of 1 µM (K562‐r and LAMA84‐r) and 5 µM (K562‐R) imatinib.

Conclusions and implications: Specific metabolic markers for early detection of imatinib resistance, including increased glycolytic activity and phospholipid turnover, can be identified in resistant clones. Once validated in human isolated leukocytes, they may be used to monitor the responsiveness of CML patients to treatment.
Mechanical Dissociation of Swine Liver to Produce Organoid Units for Tissue Engineering and In Vitro Disease Modeling
Authors: Irani Katayun , Pomerantseva Irina , Hart Alison R. , Sundback Cathryn A. , Neville Craig M. , Vacanti Joseph P.
Published: August 2009

The complex intricate architecture of the liver is crucial to hepatic function. Standard protocols used for enzymatic digestion to isolate hepatocytes destroy tissue structure and result in significant loss of synthetic, metabolic, and detoxification processes. We describe a process using mechanical dissociation to generate hepatic organoids with preserved intrinsic tissue architecture from swine liver. Oxygen‐supplemented perfusion culture better preserved organoid viability, morphology, serum protein synthesis, and urea production, compared with standard and oxygen‐supplemented static culture. Hepatic organoids offer an alternative source for hepatic assist devices, engineered liver, disease modeling, and xenobiotic testing.
Scaffold Modeling Application in the Repair of Skull Defects
Authors: Wan Weibing , Shi Pengfei
Published: August 2009

The repair of large segmental bone defects caused by trauma, inflammation, and surgery on tumors pose a major clinical challenge. Tissue‐engineered bone is emerging as a good choice for prefabricating cellular scaffold, and computer‐aided technologies and medical imaging have created new possibilities in biomedical engineering. An accurate and efficient construction of anatomic models is critical to the application of these computational methods. Such models must be validated prior to application. In this article, we explore the potential of combining these techniques to scaffold and repair a pediatric skull. Working under the hypothesis that the autogenously cultivated osteoblasts can be grown on individualized scaffolds to improve bone regeneration in skull defects, we focus our study on potential problems concerning the segmentation, reconstruction, and mesh simplification for a pediatric skull. We also propose a new framework to improve the accuracy of the model entity from image segmentation to mesh simplification.
What's new in Guillain‐Barré syndrome in 2007–2008?*
Authors: Van Doorn Pieter A.
Published: August 2009

The years 2007 and early 2008 have been an exciting time for Guillain‐Barré syndrome (GBS) research. Epidemiological studies have shown that the incidence of GBS remains stable at about 2/100,000 per year but that there have been changes in hospitalization use, likely due to the widespread availability of IVIg. Research into mechanisms has shown the importance of single amino acids in Campylobacter jejuni and the importance of ganglioside conformation. In a murine model of anti‐ganglioside antibody‐mediated neuropathy, Eculizumab was effective in reversing clinical disease and preventing pathology. This suggests trials of Eculizumab in GBS should be considered. Unfortunately, there are no new randomized controlled trials in GBS to report although the unmet need is great.
Schwann cells express the macrophage mannose receptor and MHC class II. Do they have a role in antigen presentation?
Authors: Baetas‐da‐Cruz Wagner , Alves Lucineia , Pessolani Maria Cristina V. , Barbosa Helene S. , Régnier‐Vigouroux Anne , Corte‐Real Suzana , Cavalcante Leny A.
Published: August 2009

The mannose receptor (MR) is a transmembrane glycoprotein, postulated to be a link between innate and adaptive immunity. MR is expressed in several cell types but no information is available on that for Schwann cells (SC). We show that rodent SC in primary cultures take up the MR ligand mannosyl/bovine serum albumin‐fluorescein isothiocyanate (man/BSA‐FITC) in a highly specific manner and bind an antibody against the C‐terminus of the murine macrophage MR (anti‐cMR). After incubation with man/BSA‐FITC, flow cytometry demonstrates 90% positive SC, a dose‐dependent increase in tagged cellular components and near total inhibition of the neoglycoprotein uptake by d‐mannose or by the mannosylated protein horseradish peroxidase (HRP). Western blot for MR shows that SC share a unique protein of about 180 kDa with peritoneal resident macrophages. Treatment of cultured SC with interferon‐γ (IFN‐γ) or dexamethasone (DM) followed by the addition of man/BSA‐FITC and analysis by flow cytometry shows down‐ or upregulation, respectively, of man/BSA‐FITC uptake. Our results show that SC express the MR in a prospectively functional state and suggest an antigen‐presenting function of SC, compatible with a role in infectious/inflammatory states of the peripheral nervous system.
Subcutaneous immunoglobulin therapy for multifocal motor neuropathy
Authors: Eftimov Filip , Vermeulen Marinus , De Haan Rob J. , Van Den Berg Leonard H. , Van Schaik Ivo N.
Published: August 2009

The objective of this study was to investigate whether subcutaneous immunoglobulin (SCIg) treatment is feasible and safe in maintaining muscle strength of patients with multifocal motor neuropathy (MMN). Patients fulfilling the EFNS/PNS criteria for definite MMN treated with intravenous immunoglobulin (IVIg) were switched to weekly SCIg in a single‐center, open‐label pilot intervention study. The first group of patients started with a SCIg dose equivalent to 50% of the IVIg maintenance dose. In case of deterioration, patients received a loading dose of IVIg and doubling of SCIg dose. The second group started with a dose equivalent to the IVIg maintenance dose. Primary outcome was the Medical Research Council (MRC) sum score from 10 muscle groups. Secondary outcomes were grip and pinch strength, dexterity, disability, quality of life, adverse events, and serum immunoglobulin concentrations. Ten patients were included, five in both groups. In the first group, one patient withdrew informed consent due to local adverse events, four deteriorated. In the second group, four out of five patients maintained muscle strength with SCIg during the 6 months follow‐up. Local adverse events were frequent, especially during first weeks of treatment, but generally well tolerated. Seven mild systemic adverse events were reported, all but one in the first week of treatment. In some, but not all MMN patients in this study, SCIg therapy was feasible and safe and maintained strength as well as IVIg. SCIg may be a viable alternative maintenance therapy in some patients with MMN currently receiving IVIg.