bluuebunny/crossref_metadata_2025 huggingface dataset:
AN AGENT-BASED APPROACH TO MODELING MAMMALIAN EVOLUTION: HOW RESOURCE DISTRIBUTION AND PREDATION AFFECT BODY SIZE
Authors: KANDLER ANNE , SMAERS JEROEN B.
Published: August 2011

Macro-evolutionary investigations into cross-scale patterns of body size variation have put many of the pieces of the evolutionary body size puzzle in place. To further tackle micro- and meso-scale process-based reasons underlying changes in body size, researchers compare natural populations across different habitat structures, assessing which habitat structures correspond to which changes in body size variation. The complex multi-scale dynamics underlying the effect of the external environment on body size evolution, however, inherently limits empirical interpretations with regard to the differential contribution of particular aspects of habitat architecture on body size variation, leaving open many questions as to the how and why of changes in body size variation across different habitats. We develop an agent-based simulation approach with the principal aim of investigating the differential effects of particular habitat conditions on the evolution of body size and other life history traits. Our approach simulates animals' individual decisions with regard to growth and reproduction, and records their effect on population-level variation across different habitat structures. This approach has the potential to include numerous different habitat conditions and/or growth laws and allows detailed controlled comparisons of the isolated effects of particular habitat conditions and/or perturbations. In the current study, we assess the usefulness of our approach in a pilot exploration of the effects of predation and resource distribution on body size variation in mammals. We find independent effects of predation, resource availability and resource predictability on changes in body size and quantify the relation between body size and population size across different habitat conditions.
THE EVOLUTION OF ETHNOLINGUISTIC DIVERSITY
Authors: CURRIE THOMAS E. , MACE RUTH
Published: August 2011

Humans divide themselves up into groups based on a shared cultural identity and common descent. Culturally inherited differences in dress, language, and institutions are often used as symbolic markers of the boundaries of these ethnic groups. Relatively little is known about the function of such ethnic groups, and why ethnic diversity is high in some regions yet lower in others. In this paper, we demonstrate how investigating the spatial distribution of ethnolinguistic groups can reveal the factors that affect the origin and maintenance of human ethnic group diversity. Here we describe the use of a Geographic Information System to construct a large database that integrates information about languages with a number of environmental, ecological, and ethnographic variables. Using these data on the spatial distribution of ethnolinguistic groups, we employ a hierarchical linear modeling approach to test a variety of hypotheses concerning the function of such groups. Despite revealing intriguing spatial patterns such as the latitudinal gradient in ethnolinguistic diversity, previous analyses suggested that the direct effects of environmental variables on the distribution of ethnolinguistic groups were in fact quite small. Here we show that the strength of the relationship between ethnolinguistic area and environmental variables is stronger in societies whose primary mode of subsistence is foraging. We then go on to demonstrate this same finding using the estimated native distributions of ethnolinguistic group in the Americas and Australia. In particular, Net Primary Productivity is shown to be a good predictor of the area covered by ethnolinguistic groups in foragers but not in agriculturalists. This provides support for the idea that the factors affecting ethnic diversity have changed in a systematic way with changes in subsistence strategies and social organization. We highlight future avenues for spatially explicit investigations of the evolution of ethnic diversity, and suggest that the evolutionary ecological approach adopted here may provide important insights into processes affecting ethnic diversity in the modern world.
GEOGRAPHICAL MODELING FOR ARCHAEOLOGY AND HISTORY: TWO CASE STUDIES
Authors: WILSON ALAN
Published: August 2011

This paper explores the role of mathematical models in archaeology and history. Variants of a particular model — an entropy-maximizing spatial interaction model which also functions as a location model — are presented through two case studies. The first is an example from Archaeology which throws light on settlement sizes in the 9th and 8th century BC Greece; the second is from History and explores the evolution of the United States' urban system from 1790–1870 with particular reference to the impact of railways. The approach is essentially interdisciplinary and uses concepts from Geography, Economics, Physics and Ecology.
NEUTRAL EVOLUTION: A NULL MODEL FOR LANGUAGE DYNAMICS
Authors: BLYTHE RICHARD A.
Published: August 2011

We review the task of aligning simple models for language dynamics with relevant empirical data, motivated by the fact that this is rarely attempted in practice despite an abundance of abstract models. We propose that one way to meet this challenge is through the careful construction of null models. We argue in particular that rejection of a null model must have important consequences for theories about language dynamics if modeling is truly to be worthwhile. Our main claim is that the stochastic process of neutral evolution (also known as genetic drift or random copying) is a viable null model for language dynamics. We survey empirical evidence in favor and against neutral evolution as a mechanism behind historical language changes, highlighting the theoretical implications in each case.
QUANTITATIVE MODELING OF THESACCHAROMYCES CEREVISIAEFLR1 REGULATORY NETWORK USING AN S-SYSTEM FORMALISM
Authors: CALÇADA DULCE , VINGA SUSANA , FREITAS ANA T. , OLIVEIRA ARLINDO L.
Published: August 2011

In this study we address the problem of finding a quantitative mathematical model for the genetic network regulating the stress response of the yeast Saccharomyces cerevisiae to the agricultural fungicide mancozeb. An S-system formalism was used to model the interactions of a five-gene network encoding four transcription factors (Yap1, Yrr1, Rpn4 and Pdr3) regulating the transcriptional activation of the FLR1 gene. Parameter estimation was accomplished by decoupling the resulting system of nonlinear ordinary differential equations into a larger nonlinear algebraic system, and using the Levenberg–Marquardt algorithm to fit the models predictions to experimental data. The introduction of constraints in the model, related to the putative topology of the network, was explored. The results show that forcing the network connectivity to adhere to this topology did not lead to better results than the ones obtained using an unrestricted network topology. Overall, the modeling approach obtained partial success when trained on the nonmutant datasets, although further work is required if one wishes to obtain more accurate prediction of the time courses.
DNA-Interaction and nuclease activity of porphyrin-hydroxamic acid derivatives in the presence of lanthanides
Authors: Chalbot Marie-Cécile , Gryllos Leonidas , Kefokeris Kosmas , Manoussakis Nikos , Verchère-Béaur Catherine , Perrée-Fauvet Martine , Coutsolelos Athanassios G.
Published: August 2011

The DNA-binding modes and nuclease activity of methylpyridiniumyl/phenyl-hydroxamic acid porphyrin adducts (PHAs) have been studied. These compounds are derived from the tetracationic meso-tetrakis(N-methyl-4-pyridiniumyl)porphyrin (H2TMPyP-4) by replacing one or two pyridinium rings by a phenyl group. A hydroxamic acid function was connected by a polymethylenic chain of 3 to 5 carbon atoms to the meta or para position of the phenyl group. Different DNA-interaction modes were observed depending on the number of charges and hydroxamic acid functions. The nuclease activity in the presence of lanthanides was shown to be depending on the 1/r0 ratio and the nature of the lanthanide ion, and the optimum conditions are depicted after a systematic study.
CHARMONIUM AND BOTTOMONIUM TRANSITIONS FROM EFFECTIVE FIELD THEORY
Authors: MEIßNER ULF-G.
Published: August 2011

The effects of intermediate charmed mesons on charmonium transitions with the emission of one pion or eta meson are studied systematically. Based on a non-relativistic effective field theory we show that charmed meson loops are enhanced compared to the corresponding tree-level contributions for transitions between two S-wave charmonia as well as for transitions between two P-wave charmonia. On the contrary, for the transitions between one S-wave and one P-wave charmonium state, the loops need to be analyzed case by case and often appear to be suppressed. Extending these considerations to the b-quark sector, we propose a new method to extract the light quark mass ratio mu/md using the ϒ(4S) → hbπ0(η) bottomonia transitions.
Vub AND WEAK ANNIHILATION IN INCLUSIVE SEMILEPTONIC D/Ds DECAYS
Authors: KAMENIK JERNEJ F.
Published: August 2011

We search for signals of Weak Annihilation in inclusive semileptonic D decays. We consider both the widths and the lepton energy moments. The analysis of Cleo data shows no clear evidence of Weak Annihilation, and allows us to put bounds on its relevance in charmless B semileptonic decays.
RARE AND FORBIDDEN CHARM DECAYS
Authors: GOLOB BOŠTJAN
Published: August 2011

We review the recent measurements of rare and forbidden decays of charmed mesons at the B-factories. A preliminary result of the first measurement of orbitally excited [Formula: see text] meson radiative decay to D0γ final state, and the most sensitive determination of limits on the leptonic D0 → ℓ+ ℓ- decays are briefly described.
ANGULAR CORRELATIONS IN $D\bar D\to(VV)(VV)$ COHERENT DECAYS
Authors: CHARLES JÉRÔME , DESCOTES-GENON SÉBASTIEN , KANG XIAN-WEI , LI HAI-BO
Published: August 2011

We report on our recent proposal to consider correlated [Formula: see text] decays to vector mesons. Thanks to the quantum and angular correlations, we show that new observables appear, that allow either to search for CP-violation or to extract the hadronic phase in D → Kπ.
A MOLECULAR INTERPRETATION FOR THE $D^*_{s2}(2573)$, THE PREDICTION OF NOVEL EXOTIC CHARMED MESONS AND NARROW N*, Λ* RESONANCES AROUND 4.3 GeV
Authors: MOLINA R. , OSET E. , BRANZ T. , WU JIA-JUN , ZOU B. S.
Published: August 2011

In this talk we review the vector-vector and vector-baryon interaction within the hidden gauge formalism in a coupled channel unitary approach. The vector-vector interaction is studied for all the sectors not studied before: C = 0; S = 1 (hidden-charm), C = 1, S = 1, and the flavor exotic sectors C = 1; S = -1, 2 and C = 2; S = 0, 1, 2. We find nine states, four of them in the C = 1; S = 1 sector, where one can be identified with the [Formula: see text] and it is interpreted as a D* K* molecular state. The other five resonances are found in the flavor exotic sectors C = 1; S = -1, C = 2; S = 0, 1 and can be considered as [Formula: see text], D* D* and [Formula: see text] molecular states. In the case of the vector-baryon interaction we generate hidden charm resonances around 4.3 GeV, without or with strangeness, N*, Λ*. Nevertheless, there is not experimental evidence of such states yet.
RESULTS ON CHARM BARYON SPECTROSCOPY FROM TEVATRON
Authors:   On behalf of the CDF Collaboration., WICK FELIX
Published: August 2011

Due to an excellent mass resolution and a large amount of available data, the CDF experiment, located at the Tevatron proton-antiproton accelerator, allows the precise measurement of spectroscopic properties, like mass and decay width, of a variety of states. This was exploited to examine the first orbital excitations of the Λc baryon, the resonances Λc(2595) and Λc(2625), in the decay channel [Formula: see text], as well as the Λc spin excitations Σc(2455) and Σc(2520) in its decays to [Formula: see text] and [Formula: see text] final states in a data sample corresponding to an integrated luminosity of 5.2 fb-1. We present measurements of the mass differences with respect to the Λc and the decay widths of these states, using significantly higher statistics than previous experiments.
UNQUENCHED QUARK MODEL DESCRIPTION OF CHARMONIUM
Authors: GONZÁLEZ P.
Published: August 2011

We show that the charmonium spectrum may be reproduced to a good precision by means of a semirelativistic quark model approach based on a universal static potential effectively incorporating effects from sea quark-antiquark pairs. Detailed predictions for upcoming data are derived.
REVIEW ON QCD SUM RULES CALCULATIONS FOR EXOTICS CHARMONIUM
Authors: NIELSEN MARINA
Published: August 2011

Many new states in the charmonium mass region were recently discovered by the BaBar, Belle and CDF Collaborations. We use the QCD Sum Rule approach to study the possible structure of some of these states.
PSI TO N NBAR m
Authors: BARNES T.
Published: August 2011

In this invited talk I discuss two recent applications of charmonium (Ψ) decays to [Formula: see text] final states, where N is a nucleon and m is a light meson. There are several motivations for studying these decays: 1) They are useful for the study of N* spectroscopy; 2) they can be used to estimate cross sections for the associated charmonium production processes [Formula: see text], which PANDA plans to exploit in searches for charmonium hybrid exotics; and 3) they may allow the direct experimental measurement of NNm (meson-nucleon) strong couplings, which provide crucial input information for meson exchange models of the NN force. The latter two topics are considered in this talk, which will also compare results from a simple hadron pole model of these decays to recent experimental data.
CHARM 2010: THEORY SUMMARY
Authors: BARNES T.
Published: August 2011

This invited summary gives some concluding remarks regarding theoretical aspects of the research presented at Charm 2010. I will specialize to the role of theory and the relative reach of theory and experiment in three of the major areas of charm physics address at this conference, specifically 1) charm production, 2) charm weak decays, and 3) charm hadron spectroscopy. After a discussion of the status of progress on representative topics in each of these areas I will conclude with a previously unrelated Feynman story from a conference in the early days of charm.
Insulin-like growth factor as a novel stimulator for somatolactin secretion and synthesis in carp pituitary cells via activation of MAPK cascades
Authors: Jiang Quan , Ko Wendy K. W. , Wong Anderson O. L.
Published: August 2011

Somatolactin (SL), a member of the growth hormone/prolactin family, is a pituitary hormone unique to fish models. Although SL is known to have diverse functions in fish, the mechanisms regulating its secretion and synthesis have not been fully characterized. Using grass carp pituitary cells as a model, here we examined the role of insulin-like growth factor (IGF) in SL regulation at the pituitary level. As a first step, the antisera for the two SL isoforms expressed in the carp pituitary, SLα and SLβ, were produced, and their specificity was confirmed by antiserum preabsorption and immunohistochemical staining in the carp pituitary. Western blot using these antisera revealed that grass carp SLα and SLβ could be N-linked glycosylated and their basal secretion and cell content in carp pituitary cells could be elevated by IGF-I and -II treatment. These stimulatory effects occurred with parallel rises in SLα and SLβ mRNA levels, and these SL gene expression responses were not mimicked by insulin but blocked by IGF-I receptor inactivation. In carp pituitary cells, IGF-I and -II could induce rapid phosphorylation of IGF-I receptor, MEK1/2, ERK1/2, MKK3/6, and p38 MAPK; and SLα and SLβ secretion, protein production, and mRNA expression caused by IGF-I and -II stimulation were negated by inactivating MEK1/2 and p38 MAPK. Parallel inhibition of PI3K and Akt, however, were not effective in these regards. These results, taken together, provide evidence that IGF can upregulate SL secretion and synthesis at the pituitary level via stimulation of MAPK- but not PI3K/Akt-dependent pathways.
Prediction of B‐cell Linear Epitopes with a Combination of Support Vector Machine Classification and Amino Acid Propensity Identification
Authors: Wang Hsin-Wei , Lin Ya-Chi , Pai Tun-Wen , Chang Hao-Teng
Published: August 2011

Epitopes are antigenic determinants that are useful because they induce B‐cell antibody production and stimulate T‐cell activation. Bioinformatics can enable rapid, efficient prediction of potential epitopes. Here, we designed a novel B‐cell linear epitope prediction system called LEPS, Linear Epitope Prediction by Propensities and Support Vector Machine, that combined physico‐chemical propensity identification and support vector machine (SVM) classification. We tested the LEPS on four datasets: AntiJen, HIV, a newly generated PC, and AHP, a combination of these three datasets. Peptides with globally or locally high physicochemical propensities were first identified as primitive linear epitope (LE) candidates. Then, candidates were classified with the SVM based on the unique features of amino acid segments. This reduced the number of predicted epitopes and enhanced the positive prediction value (PPV). Compared to four other well‐known LE prediction systems, the LEPS achieved the highest accuracy (72.52%), specificity (84.22%), PPV (32.07%), and Matthews′ correlation coefficient (10.36%).
Operative Management of Sciatic Nerve Palsy due to Impingement on the Metal Cage after Total Hip Revision: Case Report
Authors: Bistolfi Alessandro , Massazza Giuseppe , Deledda Davide , Lioce Elisa , Crova Maurizio
Published: August 2011

This paper discusses a sciatic nerve palsy developed after a right total hip revision with a Burch-Schneider metal cage. A sciatalgic nerve pain appeared after surgery, while the palsy developed in about fifteen days. An electromyography showed the delay of the nerve impulse gluteal level. During the surgical exploration of the hip, a compression of the nerve on the metal cage was observed. The nerve was isolated, released from the fibrotic tissue and from the impingement, and was protected with a muscular flap. The recover from the pain was immediate, while the palsy recovered one month later.
Targeting HSP 90 Induces Apoptosis and Inhibits Critical Survival and Proliferation Pathways in Multiple Myeloma
Authors: Khong Tiffany , Spencer Andrew
Published: August 2011

The second most commonly diagnosed hematologic malignancy, multiple myeloma, affects predominantly older patients (>60s) and is characterized by paraprotein in the serum or urine. Clinical manifestations include anemia, hypercalcaemia, progressive renal impairment, and osteolytic bone destruction. Despite promising new therapies, multiple myeloma eventually relapses in almost all patients. HSP are ubiquitous and highly conserved in prokaryotes and eukaryote organisms. Exposure to a broad range of stimuli results in increased HSP protein expression. These chaperone proteins are involved in protein transportation, prevent protein aggregation, and ensure correct folding of nascent and stress-accumulated misfolded proteins. In cancer, HSP expression is dysregulated, resulting in elevated expression, which promotes cancer by preventing programmed cell death and supporting autonomous cells growth, ultimately leading to resistance to heat, chemotherapy, and other stresses. Client proteins of HSP90 such as AKT, p53, MEK, STAT3, and Bcr-Abl are vital in tumor progression, including multiple myeloma, and their maturation and stability is dependent on HSP90. Therefore, inhibition of HSP90 via a HSP90 inhibitor (such as NVP-HSP990) should interrupt multiple signaling pathways essential for oncogenesis and growth in multiple myeloma. Our study showed that NVP-HSP990 triggered apoptosis in a panel of human multiple myeloma cells, induced cell-cycle arrest, PARP cleavage, downregulation of client proteins, the inability to reactivate phospho-STAT3 following exogenous IL-6 stimulation, and it synergized with azacytidine and bortezomib in cell lines and primary multiple myeloma samples. The mechanism of HSP90 inhibition in multiple myeloma warrants further evaluation. Mol Cancer Ther; 10(10); 1909–17. ©2011 AACR.
Estimated Prevalence of Acoustic Cranial Windows and Intracranial Stenosis in the US Elderly Population: Ultrasound Screening in Adults for Intracranial Disease Study
Authors: Suri M. Fareed K. , Georgiadis Alexandros L. , Tariq Nauman , Vazquez Gabriela , Qureshi Naeem , Qureshi Adnan I.
Published: August 2011

Background: Intracranial atherosclerosis is an important etiology of stroke in the USA, but its prevalence in the general population remains unknown. This study was performed to determine the feasibility of transcranial Doppler ultrasound (TCD) for general population screening and to estimate the prevalence of intracranial stenosis in the USA. Methods: We used a public database to randomly select 99 subjects aged 65–84 years residing in a well-defined geographic area. For all subjects clinical history was reviewed, blood pressure was recorded and TCD examination was performed to identify intracranial stenosis. Results: The mean age of subjects was 72 years, 42 were men, and 17 were African-Americans. All acoustic windows were present in 77 subjects. After multivariate adjustment, the odds of absence of a bone window were higher in African-Americans [odds ratio (OR) 6.0, 95% confidence interval (CI) 1.8–2.0], nonsmokers (OR 3.1, 95% CI 1.0–9) and those with a high BMI (9% higher odds per index point). Among 77 subjects who had all acoustic windows present, intracranial stenosis of >50% was identified in 6.5%, and intracranial stenosis of any severity was identified in 16% of the persons. Intracranial stenosis was most prevalent in the middle cerebral artery (6%). Conclusion: Presence of acoustic windows is associated with vascular risk factors. Based on the high prevalence of significant intracranial stenosis in the US elderly population, it is feasible and important to perform a large-scale population-based study for this disease entity.
Intratympanic Steroid Therapy Using the Silverstein Microwick™ for Refractory Sudden Sensorineural Hearing Loss Increases Speech Intelligibility
Authors: Barriat Sébastien , van Wijck France , Staecker Hinrich , Lefebvre Philippe P.
Published: August 2011

Objective:To determine whether delivery of methylprednisolone to the round window (administered for 10 days after the onset of the hearing loss) can improve hearing and, in particular, speech intelligibility, after the failure of conventional treatment for idiopathic sudden sensorineural hearing loss. Results: Of the 26 patients enrolled in this non-randomized retrospective study, 14 patients (54%) showed an improvement in the pure tone average (PTA) and 12 remained unchanged. The topical steroid therapy brought about an overall improvement in PTA of 13.5 ± 7.3 dB for the 26 patients enrolled. The auditory capacity index, defined as the mean speech discrimination score obtained at 40, 55 and 70 dB, improved by 24.2 ± 8.7% in 26 patients. Among the 12 patients with a stable PTA, 9 showed an increase in speech intelligibility. Conclusion: Local administration of steroids to the inner ear through the round window route improves hearing and speech intelligibility in patients after failure of conventional therapy.
Hyperdense Middle Cerebral and/or Internal Carotid Arteries in Acute Ischemic Stroke: Rate, Predictive Factors and Influence on Clinical Outcome
Authors: Paciaroni Maurizio , Agnelli Giancarlo , Floridi Piero , Alberti Andrea , Acciarresi Monica , Venti Michele , Alagia Maria Gabriella , Fiacca Andrea , Gallina Maria Cristina , Guercini Giorgio , Pantaleoni Roberto , Leone Francesca , Pieroni Alessio , Caso Valeria
Published: August 2011

Background: In patients with acute stroke, the hyperdense middle cerebral artery (MCA) and internal carotid artery (ICA) signs on CT scans are markers of early ischemia, but their prognostic implications remain unclear.The aims of this prospective study were to assess: (1) the occurrence rate of hyperdense MCA and/or ICA in patients admitted for acute ischemic stroke; (2) the risk factors for hyperdense MCA and/or ICA; (3) the correlation between hyperdense MCA and/or ICA and functional outcome at 3 months. Methods: Consecutive patients admitted with ischemic stroke between 1 January 2006 and 30 June 2010 were included in this prospective single-centre cohort study. Results: 1,010 patients (mean age 71.9 years; 56.7% males) were included in the study. Among these patients, 148 (14.7%; mean age 71.2 years; 52% males) had hyperdense MCA and/or ICA. Overall, 163 patients (16.1%) had a final infarct covering more than one third of the MCA territory. Seventy-eight of 148 patients (52.7%) with hyperdense MCA and/or ICA had an infarct involving more than one third of the MCA territory compared to 85 of the 862 patients without artery hyperdensity (9.9%). At 3 months, 18 patients were lost to follow-up, 325 patients (32.8%) were disabled and 165 died (16.5%). Age (OR 1.06 for 1 added year; 95% CI 1.04–1.08), National Institute of Health Stroke Scale score for 1 added point on admission (OR 1.2; 95% CI 1.2–1.3), stroke due to atherosclerosis (OR 2.3; 95% CI 1.0–5.4), hemorrhagic transformation of the ischemic lesion (OR 2.2; 95% CI 1.0–4.9), and hyperdense MCA and/or ICA (OR 2.0; 95% CI 1.0–4.0) were associated with adverse outcome. Conclusions: In this prospective cohort of patients with acute ischemic stroke, we observed an incidence of hyperdense MCA and/or ICA arteries of about 15%; hyperdense MCA and/or ICA were associated with a final infarct involving more than one third of the MCA territory and poor functional outcome at 3 months.
The Protochordate Ciona intestinalis Has a Protein Like Full-Length Vertebrate Fibrinogen
Authors: Doolittle Russell F.
Published: August 2011

In a recent review, a putative fibrinogen-like protein in the protochordate Ciona intestinalis was noted. Unfortunately, computer-directed splicing had omitted several exons, mistakenly generating a single long polypeptide chain. In fact, 3 consecutive genes exist, the translated versions of which are homologous to individual vertebrate fibrinogen chains. The circulating form is likely a 6-chain covalent dimer, just as occurs in vertebrates.
Pre- and Postnatal Methyl Deficiency in the Rat Differentially Alters Glucose Homeostasis
Authors: Smith Greg C. , Konycheva Galina , Dziadek Marie A. , Ravelich Susan R. , Patel Selina , Reddy Shiva , Breier Bernhard H. , Vickers Mark H. , Owens Julie A. , Ferguson Lynnette R.
Published: August 2011

Background/Aims: Early-life methyl-donor deficiency is implicated in growth restriction and later-life development of type 2 diabetes mellitus. We ascertained whether dietary methyl-donor deficiency in the mother during pregnancy or during postweaning growth in the rat would impair glucose homeostasis, insulin secretion and pancreatic endocrine development in young adults. Methods: Effects of maternal methyl deficiency (90% deficiency in methionine, folate and choline) were compared with those of postweaning methyl deficiency and with control diets for effects on growth, impaired glucose tolerance, insulin secretion and pancreas development in offspring. Studies focussed on male offspring, which have been shown more susceptible to early-life influences on later disease development. Results: Prenatal methyl deficiency delayed delivery, restricted birthweight by 22%, reduced litter size by 33% and increased offspring mortality to 23% shortly after birth. It reduced relative endocrine pancreatic mass in adult male offspring to 46% of endocrine mass in controls, but only mildly impaired their glucose tolerance and insulin secretion. In contrast, postweaning methyl deficiency restricted growth of male rats and reduced relative pancreatic endocrine mass (–40%), but improved their glucose tolerance, despite decreased insulin secretion. Conclusion: It is clear that the global undernutrition (UN) during pregnancy in rodents alters glucose metabolism in adult offspring. It has been hypothesised that alterations in epigenetic mechanisms may underlie this phenotype. However, removing all methyl donors during pregnancy, which are essential for epigenetic processes in development, did not cause any alteration in glucose metabolism in offspring as seen in the global UN model.
Khat Use and Trait Anger: Effects on Affect Regulation during an Acute Stressful Challenge
Authors: Bongard Stephan , al’Absi Mustafa , Khalil Najat Sayem , Al Habori Molham
Published: August 2011

Khat (Catha edulis) is a widely used stimulating drug often consumed in daily routine in Yemen and East African countries. Chewing khat acutely elicits states of euphoria and feelings of well-being which later shift into emotional instability and low mood. Little is known about emotional regulation in habitual khat chewers. In this study, we compared self-reports on trait anger as well as positive and negative affect responses to a mental arithmetic challenge. Participants included 135 men and women from Yemen who chew khat regularly, occasionally or not at all. Participants attended a laboratory session that involved resting periods and performing a math challenge. Analyses of variance and regression show that regular khat chewing is associated with higher trait anger, more pronounced negative responses during stress and less pronounced positive emotional states. These results suggest that regular khat chewing is associated with disturbances in emotion regulation processes.
Determination of Dialysis Dose: A Clinical Comparison of Methods
Authors: Ahrenholz Peter , Taborsky Petr , Bohling Margot , Rawer Peter , Ibrahim Noureddin , Gajdos Martin , Machek Petr , Sagova Michaela , Gruber Hans , Moucka Pavel , Rychlik Ivan , Leimenstoll Gerd , Vyskocil Pavel , Toenne Gunter , Possnickerova Jindriska , Woggan Joerg , Riegel Werner , Schneider Helmut , Wojke Ralf
Published: August 2011

Background: Guidelines recommend regular measurements of the delivered hemodialysis dose Kt/V. Nowadays, automatic non-invasive online measurements are available as alternatives to the conventional method with blood sampling, laboratory analysis, and calculation. Methods:In a prospective clinical trial, three different methods determining dialysis dose were simultaneously applied: Kt/VDau (conventional method with Daugirdas’ formula), Kt/VOCM [online clearance measurement (OCM) with urea distribution volume V based on anthropometric estimate], and Kt/VBCM [OCM measurement with V measured by bioimpedance analysis (Body Composition Monitor)]. Results:1,076 hemodialysis patients were analyzed. The dialysis dose was measured as Kt/VDau = 1.74 ± 0.45, Kt/VOCM = 1.47 ± 0.34, and Kt/VBCM = 1.65 ± 0.42. The difference between Kt/VOCM and Kt/VBCM was due to the difference between anthropometric estimated VWatson and measured VBCM. Compared to Kt/VDau, Kt/VOCM was 15% lower and Kt/VBCM 5% lower. Kt/VDau was incidentally prone to falsely high values due to operative errors, whereas in these cases OCM-based measurements Kt/VOCM and Kt/VBCM delivered realistic values. Conclusions:The automated OCM Kt/VOCM with anthropometric estimation of urea distribution volume was the easiest method to use, but Kt/VBCM with measured urea distribution volume was closer to the conventional method.
Proteinase-Activated Receptors 1 and 2 Exert Opposite Effects on Renal Renin Release
Authors: Höcherl Klaus , Gerl Melanie , Schweda Frank
Published: August 2011

Proteinase-activated receptors (PARs) 1 to 4 are highly expressed in the kidney and are involved in the regulation of renal hemodynamics and tubular function. Since intravascular infusion of the proteinase thrombin, which activates PARs, has been shown to decrease plasma renin activity in rats, we investigated the effects of the respective PAR subtypes on renin release using the isolated perfused mouse kidney model. Thrombin dose-dependently reduced perfusate flow and inhibited renin secretion rates (RSRs) that had been prestimulated by the β-adrenoreceptor agonist isoproterenol. The suppression of RSRs was prevented by the selective PAR1 inhibitor SCH79797, and direct activation of PAR1 by TFLLR mimicked the effects of thrombin on RSRs and vascular tone. Moreover, TFLLR suppressed the stimulations of RSRs in response to the loop diuretic bumetanide, to prostaglandin E
2
, or to a decrease in renal perfusion pressure but not in response to a reduction in extracellular calcium. The PAR2-activating peptide SLIGRL concentration dependently increased RSR and perfusate flow. The stimulation of RSRs by SLIGRL was markedly attenuated by
N
G
-nitro-
l
-arginine methyl ester, suggesting an NO-dependent mechanism. Activation of PAR4 by AYPGKF did not modulate RSRs or perfusate flow. PAR1 and PAR2 immunoreactivity were detected in the juxtaglomerular region and were colocalized with renin immunoreactivity. Our data provide evidence that PAR1 activation inhibits renal renin secretion and induces renal vasoconstriction, whereas PAR2 activation stimulates renin release and induces vasodilation mainly via the release of NO.
Endothelial Dysfunction and Low-Grade Inflammation Are Associated With Greater Arterial Stiffness Over a 6-Year Period
Authors: van Bussel Bas C. , Schouten Fleur , Henry Ronald M. , Schalkwijk Casper G. , de Boer Michiel R. , Ferreira Isabel , Smulders Yvo M. , Twisk Jos W. , Stehouwer Coen D.
Published: August 2011

Endothelial dysfunction and low-grade inflammation are associated with cardiovascular disease. Arterial stiffening plays an important role in cardiovascular disease and, thus, may be a mechanism through which endothelial dysfunction and/or low-grade inflammation lead to cardiovascular disease. We investigated the associations between, on the one hand, biomarkers of endothelial dysfunction (soluble endothelial selectin, thrombomodulin, and both vascular and intercellular adhesion molecules 1 and von Willebrand factor) and of low-grade inflammation (C-reactive protein, serum amyloid A, interleukin 6, interleukin 8, tumor necrosis factor-α and, soluble intercellular adhesion molecule 1) and, on the other hand, arterial stiffness over a 6-year period, in 293 healthy adults (155 women). Biomarkers were combined into mean
z
scores. Carotid, femoral, and brachial arterial stiffness and carotid-femoral pulse wave velocity were determined by ultrasonography. Measurements were obtained when individuals were 36 and 42 years of age. Associations were analyzed with generalized estimating equation and adjusted for sex, height, and mean arterial pressure. The endothelial dysfunction
z
score was inversely associated with femoral distensibility (β: −0.51 [95% CI: −0.95 to −0.06]) and compliance coefficients (β: −0.041 [95% CI: −0.076 to −0.006]) but not with carotid or brachial stiffness or carotid-femoral pulse wave velocity. The low-grade inflammation
z
score was inversely associated with femoral distensibility (β: −0.51 [95% CI: −0.95 to −0.07]) and compliance coefficients (β: −0.050 [95% CI: −0.084 to −0.016]) and with carotid distensibility coefficient (β: −0.910 [95% CI: −1.810 to −0.008]) but not with brachial stiffness or carotid-femoral pulse wave velocity. Biomarkers of endothelial dysfunction and low-grade inflammation are associated with greater arterial stiffness. This provides evidence that arterial stiffening may be a mechanism through which endothelial dysfunction and low-grade inflammation lead to cardiovascular disease.
A Review of Gifted and Talented Education in the United States
Authors: Bhatt Rachana
Published: August 2011

Gifted and talented education programs provide children who have been identified as having high ability in some intellectual or creative characteristic with a supplemental curriculum to their traditional coursework. Despite the popularity of these programs, the literature lacks a comprehensive review of gifted education in the United States. This policy brief aims to fill this void by providing national and state-level statistics on participation rates, funding appropriations, and policies on gifted education. Since many of the operational details of these programs are determined by local education agencies, data on a nationally representative sample of schools are then used to provide information on gifted curricula, instructor training and experience, and the selection process for admission. Finally, a review of the research on gifted education is provided. This research highlights that gifted programs vary widely and that further research on this topic can provide valuable information to policy makers and educators.
The Neural Basis of Reversible Sentence Comprehension: Evidence from Voxel-based Lesion Symptom Mapping in Aphasia
Authors: Thothathiri Malathi , Kimberg Daniel Y. , Schwartz Myrna F.
Published: August 2011

We explored the neural basis of reversible sentence comprehension in a large group of aphasic patients (n = 79). Voxel-based lesion symptom mapping revealed a significant association between damage in temporo-parietal cortex and impaired sentence comprehension. This association remained after we controlled for phonological working memory. We hypothesize that this region plays an important role in the thematic or what–where processing of sentences. In contrast, we detected weak or no association between reversible sentence comprehension and the ventrolateral pFC, which includes Broca's area, even for syntactically complex sentences. This casts doubt on theories that presuppose a critical role for this region in syntactic computations.
Attentional Capture by Salient Distractors during Visual Search Is Determined by Temporal Task Demands
Authors: Kiss Monika , Grubert Anna , Petersen Anders , Eimer Martin
Published: August 2011

The question whether attentional capture by salient but task-irrelevant visual stimuli is triggered in a bottom–up fashion or depends on top–down task settings is still unresolved. Strong support for bottom–up capture was obtained in the additional singleton task, in which search arrays were visible until response onset. Equally strong evidence for top–down control of attentional capture was obtained in spatial cueing experiments in which display durations were very brief. To demonstrate the critical role of temporal task demands on salience-driven attentional capture, we measured ERP indicators of capture by task-irrelevant color singletons in search arrays that could also contain a shape target. In Experiment 1, all displays were visible until response onset. In Experiment 2, display duration was limited to 200 msec. With long display durations, color singleton distractors elicited an N2pc component that was followed by a late Pd component, suggesting that they triggered attentional capture, which was later replaced by location-specific inhibition. When search arrays were visible for only 200 msec, the distractor-elicited N2pc was eliminated and was replaced by a Pd component in the same time range, indicative of rapid suppression of capture. Results show that attentional capture by salient distractors can be inhibited for short-duration search displays, in which it would interfere with target processing. They demonstrate that salience-driven capture is not a purely bottom–up phenomenon but is subject to top–down control.
Theta Dynamics Reveal Domain-specific Control over Stimulus and Response Conflict
Authors: Nigbur Roland , Cohen Michael X , Ridderinkhof K. Richard , Stürmer Birgit
Published: August 2011

Cognitive control allows us to adjust to environmental changes. The medial frontal cortex (MFC) is thought to detect conflicts and recruit additional resources from other brain areas including the lateral prefrontal cortices. Here we investigated how the MFC acts in concert with visual, motor, and lateral prefrontal cortices to support adaptations of goal-directed behavior. Physiologically, these interactions may occur through local and long-range synchronized oscillation dynamics, particularly in the theta range (4–8 Hz). A speeded flanker task allowed us to investigate conflict-type-specific control networks for perceptual and response conflicts. Theta power over MFC was sensitive to both perceptual and response conflict. Interareal theta phase synchrony, however, indicated a selective enhancement specific for response conflicts between MFC and left frontal cortex as well as between MFC and the presumed motor cortex contralateral to the response hand. These findings suggest that MFC theta-band activity is both generally involved in conflict processing and specifically involved in linking a neural network controlling response conflict.
Schools and the Diversity Transition in the Wealthy Societies of the West
Authors: Alba Richard
Published: August 2011

The rich countries of the West are facing a diversity transition that will unfold in the next several decades. The transition means that these societies will depend increasingly on individuals who have grown up in immigrant homes to maintain economic, social, and cultural vitality. This situation turns a spotlight on educational systems, which are crucial to preparing the children from low-status immigrant families to participate in the institutions of the mainstream. The educational gaps between native- and immigrant-origin children in France, Germany, Great Britain, the Netherlands, and the United States raise concerns about the performance of systems with very different characteristics. Yet all is not hopeless: Some modest policies seem to bring amelioration, and each system can learn from others.
Cognitive and Motivational Characteristics of Elementary Teachers in General Education Classrooms and in Gifted Programs
Authors: Hong Eunsook , Greene Mary , Hartzell Stephanie
Published: August 2011

Whether teachers in general education classrooms and in gifted programs differ in their cognitive and motivational characteristics was examined in 182 elementary school teachers. The teacher characteristics examined were epistemological beliefs (beliefs about the nature of knowledge and beliefs about the nature of learning), metacognition (planning, monitoring, and strategy selection), and motivation (self-efficacy, intrinsic motivation, and goal orientation). Teachers in gifted programs reported more sophisticated epistemological beliefs, higher learning-goal orientation, and lower performance-goal orientation than did teachers in general education classrooms. However, perceived use of metacognitive strategies, self-efficacy, and intrinsic motivation were not different between the two groups. Teachers in general reported epistemological sophistication more in the nature of learning than in the nature of knowledge, that they use cognitive strategies more so than planning and monitoring of their activities, and that they are more learning-goal oriented than performance-goal oriented. It is suggested that more courses and trainings are needed for preservice and in-service teachers so they have opportunities to learn and self-reflect on their own characteristics.

Putting the Research to Use

This study compared trait-level cognitive and motivational characteristics between teachers in gifted programs and teachers in general education classrooms. The findings provide some evidence that teachers in gifted programs and teachers in general education classrooms have characteristic differences and that gifted students in pullout programs seem to be more likely to have teachers with certain favorable characteristics. The reality is that the majority of gifted children spend most of their hours in general education classrooms. Therefore, the focus should be whether teacher training can provide opportunities for preservice and in-service teachers in general education as well as in gifted education programs, to become aware of these characteristics evidenced as having strong relationships with student learning. Beyond teacher knowledge and skills, teacher attributes and beliefs about student learning are underscored as important areas in teacher preparation for differentiating instruction for gifted children in the general education classroom. Preservice and in-service teacher trainings should provide teachers with opportunities to learn and self-reflect on their own cognitive and motivational characteristics as they develop into effective teachers.
Social deprivation and use of mental health legislation in New Zealand
Authors: O’Brien Anthony John , Kydd Robert , Frampton Christopher
Published: August 2011

Background:

Low socioeconomic status has consistently been associated with poorer health outcomes. Few studies have used ecological analysis to explore relationships between area measures of deprivation and use of mental health legislation.

Methods:

We used an ecological design to explore associations between two area measures of relative deprivation and the two most commonly used sections of New Zealand mental health legislation.

Results:

High levels of relative deprivation were positively correlated with use of both acute and long-term community care provisions of mental health legislation with the correlation with long-term care achieving significance ( r = .518, p = .016). Low levels of relative deprivation showed negative correlations with use of both provisions. The correlation of −.493 between low levels of relative deprivation and acute care provisions was significant at p = .023. In stepwise regression, the proportion of the population aged 15–64 contributed to the model for section 11, but ethnicity contributed to neither model.

Conclusion:

Mental health legislation is used disproportionately in areas with high levels of relative deprivation. The results have implications for regional allocation of funding for mental health and social services to support community-based care. Further research is needed to explore other factors that may account for the regional variation.
Theorizing Racial Inequity in Special Education
Authors: Sullivan Amanda L. , Artiles Alfredo J.
Published: August 2011

Despite decades of research examining the disproportionate representation of racial minority students in special education, our understanding of the complexity of disproportionality remains incomplete and much of the previous research was designed without a clear theoretical framework. This exploratory study applied a structural theoretical lens as a means of understanding racial inequity in special education across analytical scales, racial groups, and disability categories. The findings confirm differential risk of educational disability across racial groups. Based on the theory adopted, several hypotheses were tested regarding the relations of relative risk to district structural features, with conflicting results found.