bluuebunny/crossref_metadata_2025 huggingface dataset:
Kcna1Gene Deletion Lowers the Behavioral Sensitivity of Mice to Small Changes in Sound Location and Increases Asynchronous Brainstem Auditory Evoked Potentials But Does Not Affect Hearing Thresholds
Authors: Allen Paul D. , Ison James R.
Published: February 2012

Sound localization along the azimuth depends on the sensitivity of binaural nuclei in the auditory brainstem to small differences in interaural level and timing occurring within a submillisecond epoch and on monaural pathways that transmit level and timing cues with high temporal fidelity to insure their coincident arrival at the binaural targets. The soma and axons of these brainstem neurons are heavily invested with ion channels containing the low-threshold potassium channel subunit Kv1.1, which previousin vitroandin vivostudies suggest are important for regulating their high input–output correspondence and temporal synchrony. We compared awakeKcna1-null mutant (Kcna1−/−) mice lacking Kv1.1 withKcna1+/+ mice to determine whether Kv1.1 activity contributes to sound localization and examined anesthetized mice for absolute hearing thresholds for suprathreshold differences that may be revealed in the waveforms of auditory brainstem response potentials. The awake −/− mice tested with reflex modification audiometry had reduced sensitivity to an abrupt change in the location of a broad band noise compared to +/+ mice, while anesthetized −/− mice had normal absolute thresholds for tone pips but a high level of stimulus-evoked but asynchronous background activity. Evoked potential waveforms had progressively earlier peaks and troughs in −/− mice, but the amplitude excursions between adjacent features were identical in the two groups. Their greater excitability and asynchrony in suprathreshold evoked potentials coupled with their normal thresholds suggests that a disruption in central neural processing in −/− mice and not peripheral hearing loss is responsible for their poor sound localization.
Myrip Couples the Capture of Secretory Granules by the Actin-Rich Cell Cortex and Their Attachment to the Plasma Membrane
Authors: Huet Sébastien , Fanget Isabelle , Jouannot Ouardane , Meireles Patricia , Zeiske Tim , Larochette Nathanaël , Darchen François , Desnos Claire
Published: February 2012

Exocytosis of secretory granules (SGs) requires their delivery to the actin-rich cell cortex followed by their attachment to the plasma membrane (PM). How these reactions are executed and coordinated is still unclear. Myrip, which is also known as Slac-2c, binds to the SG-associated GTPase Rab27 and is thought to promote the delivery of SGs to the PM by recruiting the molecular motor myosin Va. Myrip also interacts with actin and the exocyst complex, suggesting that it may exert multiple roles in the secretory process. By combining total internal reflection fluorescence microscopy, single-particle tracking, a photoconversion-based assay, and mathematical modeling, we show that, in human enterochromaffin cells, Myrip (1) inhibits a class of SG motion characterized by fast and directed movement, suggesting that it facilitates the dissociation of SGs from microtubules; (2) enhances their motion toward the PM and the probability of SG attachment to the PM; and (3) increases the characteristic time of immobilization at the PM, indicating that it is a component of the molecular machinery that tether SGs to the PM. Remarkably, while the first two effects of Myrip depend on its ability to recruit myosin Va on SGs, the third is myosin Va independent but relies on the C-terminal domain of Myrip. We conclude that Myrip couples the retention of SGs in the cell cortex, their transport to the PM, and their attachment to the PM, and thus promotes secretion. These three steps of the secretory process are thus intimately coordinated.
Arg Kinase Regulates Prefrontal Dendritic Spine Refinement and Cocaine-Induced Plasticity
Authors: Gourley Shannon L. , Olevska Anastasia , Warren M. Sloan , Taylor Jane R. , Koleske Anthony J.
Published: February 2012

Adolescence is characterized by vulnerability to the development of neuropsychiatric disorders including drug addiction, as well as prefrontal cortical refinement that culminates in structural stability in adulthood. Neuronal refinement and stabilization are hypothesized to confer resilience to poor decision making and addictive-like behaviors, although intracellular mechanisms are largely unknown. We characterized layer V prefrontal dendritic spine development and refinement in adolescent wild-type mice and mice lacking the cytoskeletal regulatory protein Abl-related gene (Arg) kinase. Relative to hippocampal CA1 pyramidal neurons, which exhibited a nearly linear increase in spine density up to postnatal day 60 (P60), wild-type prefrontal spine density peaked at P31, and then declined by 18% by P56–P60. In contrast, dendritic spines in mice lacking Arg destabilized by P31, leading to a net loss in both structures. Destabilization corresponded temporally to the emergence of exaggerated psychomotor sensitivity to cocaine. Moreover, cocaine reduced dendritic spine density in wild-type orbitofrontal cortex and enlarged remaining spine heads, butarg−/−spines were unresponsive. Local application of Arg or actin polymerization inhibitors exaggerated cocaine sensitization, as did reduced gene dosage of the Arg substrate, p190RhoGAP. Genetic and pharmacological Arg inhibition also retarded instrumental reversal learning and potentiated responding for reward-related cues, providing evidence that Arg regulates both psychomotor sensitization and decision-making processes implicated in addiction. These findings also indicate that structural refinement in the adolescent orbitofrontal cortex mitigates psychostimulant sensitivity and support the emerging perspective that the structural response to cocaine may, at any age, have behaviorally protective consequences.
Parasynaptic NMDA Receptor Signaling Couples Neuronal Glutamate Transporter Function to AMPA Receptor Synaptic Distribution and Stability
Authors: Jarzylo Larissa A. , Man Heng-Ye
Published: February 2012

At synapses, two major processes occur concomitantly after the release of glutamate: activation of AMPA receptors (AMPARs) to conduct synaptic transmission and activation of excitatory amino acid transporters (EAATs) for transmitter removal. Although crosstalk between the receptors and EAATs is conceivable, whether and how the transporter activity affects AMPAR synaptic localization remain unknown. Using cultured hippocampal and cortical rat neurons, we show that inhibition of glutamate transporters leads to rapid reduction in AMPAR synaptic accumulation and total AMPAR abundance. EAAT inactivity also results in elevated internalization and reduced surface expression of AMPARs. The reduction in AMPAR amount is accompanied by receptor ubiquitination and can be blocked by suppression of proteasome activity, indicating the involvement of proteasome-mediated receptor degradation. Consistent with glutamate spillover, effect of EAAT inhibition on AMPAR distribution and stability is dependent on the activation of parasynaptically localized NR2B-containing NMDA receptors (NMDARs). Moreover, we show that neuronal glutamate transporters, especially those localized at the postsynaptic sites, are responsible for the observed effect during EAAT suppression. These results indicate a role for neuron-specific glutamate transporters in AMPAR synaptic localization and stability.
Neurosilence: Profound Suppression of Neural Activity following Intracerebral Administration of the Protein Synthesis Inhibitor Anisomycin
Authors: Sharma Arjun V. , Nargang Frank E. , Dickson Clayton T.
Published: February 2012

Early in their formation, memories are thought to be labile, requiring a process called consolidation to give them near-permanent stability. Evidence for consolidation as an active and biologically separate mnemonic process has been established through posttraining manipulations of the brain that promote or disrupt subsequent retrieval. Consolidation is thought to be ultimately mediated via protein synthesis since translational inhibitors such as anisomycin disrupt subsequent memory when administered in a critical time window just following initial learning. However, when applied intracerebrally, they may induce additional neural disturbances. Here, we report that intrahippocampal microinfusions of anisomycin in urethane-anesthetized rats at dosages previously used in memory consolidation studies strongly suppressed (and in some cases abolished) spontaneous and evoked local field potentials (and associated extracellular current flow) as well as multiunit activity. These effects were not coupled to the production of pathological electrographic activity nor were they due to cell death. However, the amount of suppression was correlated with the degree of protein synthesis inhibition as measured by autoradiography and was also observed with cycloheximide, another translational inhibitor. Our results suggest that (1) the amnestic effects of protein synthesis inhibitors are confounded by neural silencing and that (2) intact protein synthesis is crucial for neural signaling itself.
Hierarchical Processing of Face Viewpoint in Human Visual Cortex
Authors: Axelrod Vadim , Yovel Galit
Published: February 2012

The ability to recognize objects across different viewpoints (view invariance) is a remarkable property of the primate visual system. According to a prominent theory, view information is represented by view-selective mechanisms at early stages of visual processing and gradually becomes view invariant in high-level visual areas. Single-cell recording studies have also reported an intermediate step of partial view invariance for mirror-symmetric face views. Nevertheless, similar evidence for this type of hierarchical processing for face view has not been reported yet in the human visual cortex. The present functional magnetic resonance imaging study used state-of-the-art multivariate pattern analysis to explore face-view tuning in the human visual cortex. Our results revealed that consistent with a view-selective representation, face view can be successfully decoded in face and object-selective regions as well as in early visual cortex. Critically, similar neural representations for mirror-symmetric views were found in high-level but not in low-level visual areas. Our results support the notion of gradual emergence of view-invariant representation with invariance for mirror-symmetric images as an intermediate step and propose putative neural correlates of mirror-image confusion in the human brain.
Temporal Convergence of Dynamic Cell Assemblies in the Striato-Pallidal Network
Authors: Adler Avital , Katabi Shiran , Finkes Inna , Israel Zvi , Prut Yifat , Bergman Hagai
Published: February 2012

The basal ganglia (BG) have been hypothesized to implement a reinforcement learning algorithm. However, it is not clear how information is processed along this network, thus enabling it to perform its functional role. Here we present three different encoding schemes of visual cues associated with rewarding, neutral, and aversive outcomes by BG neuronal populations.

We studied the response profile and dynamical behavior of two populations of projection neurons [striatal medium spiny neurons (MSNs), and neurons in the external segment of the globus pallidus (GPe)], and one neuromodulator group [striatal tonically active neurons (TANs)] from behaving monkeys. MSNs and GPe neurons displayed sustained average activity to cue presentation. The population average response of MSNs was composed of three distinct response groups that were temporally differentiated and fired in serial episodes along the trial. In the GPe, the average sustained response was composed of two response groups that were primarily differentiated by their immediate change in firing rate direction. However, unlike MSNs, neurons in both GPe response groups displayed prolonged and temporally overlapping persistent activity. The putamen TANs stereotyped response was characterized by a single transient response group. Finally, the MSN and GPe response groups reorganized at the outcome epoch, as different task events were reflected in different response groups.

Our results strengthen the functional separation between BG neuromodulators and main axis neurons. Furthermore, they reveal dynamically changing cell assemblies in the striatal network of behaving primates. Finally, they support the functional convergence of the MSN response groups onto GPe cells.
The BDNF Val66Met Polymorphism Impairs Synaptic Transmission and Plasticity in the Infralimbic Medial Prefrontal Cortex
Authors: Pattwell Siobhan S. , Bath Kevin G. , Perez-Castro Rosalia , Lee Francis S. , Chao Moses V. , Ninan Ipe
Published: February 2012

The brain-derived neurotrophic factor (BDNF) Val66Met polymorphism is a common human single nucleotide polymorphism (SNP) that affects the regulated release of BDNF, and has been implicated in affective disorders and cognitive dysfunction. A decreased activation of the infralimbic medial prefrontal cortex (IL-mPFC), a brain region critical for the regulation of affective behaviors, has been described in BDNFMetcarriers. However, it is unclear whether and how the Val66Met polymorphism affects the IL-mPFC synapses. Here, we report that spike timing-dependent plasticity (STDP) was absent in the IL-mPFC pyramidal neurons from BDNFMet/Metmice, a mouse that recapitulates the specific phenotypic properties of the human BDNF Val66Met polymorphism. Also, we observed a decrease in NMDA and GABA receptor-mediated synaptic transmission in the pyramidal neurons of BDNFMet/Metmice. While BDNF enhanced non-NMDA receptor transmission and depressed GABA receptor transmission in the wild-type mice, both effects were absent in BDNFMet/Metmice after BDNF treatment. Indeed, exogenous BDNF reversed the deficits in STDP and NMDA receptor transmission in BDNFMet/Metneurons. BDNF-mediated selective reversal of the deficit in plasticity and NMDA receptor transmission, but its lack of effect on GABA and non-NMDA receptor transmission in BDNFMet/Metmice, suggests separate mechanisms of Val66Met polymorphism upon synaptic transmission. The effect of the Val66Met polymorphism on synaptic transmission and plasticity in the IL-mPFC represents a mechanism to account for this impact of SNP on affective disorders and cognitive dysfunction.
Fast chemical separations and laser mass spectrometry – tools for nuclear research
Authors: Trautmann N. , Wendt K.
Published: February 2012

Fast chemical separation procedures applied in nuclear research require dedicated experimental techniques. Rapid discontinuous separation procedures are illustrated by an example to isolate technetium from fission products. The use of a gas jet and its combination with a thermochromatographic separation and with the continuous solvent extraction technique SISAK is described and examples are given for the investigation of short-lived fission products. The potential of resonance ionization mass spectrometry (RIMS) as a highly sensitive technique using different experimental systems is outlined for ultra trace analysis of long-lived plutonium and neptunium isotopes, including isotope ratio measurements of the plutonium isotopes. In addition, the precise determination of the first ionization potentials (IP) of ten actinide elements up to einsteinium and of technetium carried out by using the photoionization threshold method and requiring sample sizes of ∼ 1012atoms is presented.
Distinct pattern of oxidative DNA damage and DNA repair in follicular thyroid tumours
Authors: Karger Stefan , Krause Kerstin , Engelhardt Cornelia , Weidinger Carl , Gimm Oliver , Dralle Henning , Sheu-Grabellus Sien-Yi , Schmid Kurt Werner , Fuhrer Dagmar
Published: February 2012

Increased oxidative stress has been linked to thyroid carcinogenesis. In this paper, we investigate whether oxidative DNA damage and DNA repair differ in follicular adenoma (FA) and follicular thyroid carcinoma (FTC). 7,8-Dihydro-8-oxoguanine (8-OxoG) formation was analysed by immunohistochemistry in 46 FAs, 52 FTCs and 18 normal thyroid tissues (NTs). mRNA expression of DNA repair genes OGG1, Mut Y homologue (MUTYH) and endonuclease III (NTHL1) was analysed by real-time PCR in 19 FAs, 25 FTCs and 19 NTs. Induction and repair of oxidative DNA damage were studied in rat FRTL-5 cells after u.v. irradiation. Moreover, activation of DNA damage checkpoints (ataxia telangiectasia mutated (ATM) and H2A histone family, member X (H2AFX (H2AFX))) and proliferation index (MIB-1) were quantified in 28 non-oxyphilic and 24 oxyphilic FTCs. Increased nuclear and cytosolic 8-OxoG formation was detected in FTC compared with follicular adenoma, whereby cytosolic 8-OxoG formation was found to reflect RNA oxidation. Significant downregulation of DNA repair enzymes was detected in FTC compared with FA. In vitro experiments mirrored the findings in FTC with oxidative stress-induced DNA checkpoint activation and downregulation of OGG1, MUTYH and NTHL1 in FRTL-5 cells, an effect that, however, was reversible after 24 h. Further analysis of FTC variants showed decreased oxidative DNA damage, sustained checkpoint activation and decreased proliferation in oxyphilic vs non-oxyphilic FTC. Our data suggest a pathophysiological scenario of accumulating unrepaired DNA/RNA damage in FTC vs counterbalanced DNA/RNA damage and repair in FA. Furthermore, this study provides the first evidence for differences in oxidative stress defence in FTC variants with possible implications for therapeutic response and prognostic outcome.
Work Ability Index (WAI) and Its Association with Psychosocial Factors in One of the Petrochemical Industries in Iran
Authors: Mazloumi Adel , Rostamabadi Akbar , Saraji Gabraeil Nasl , Foroushani Abbas Rahimi
Published: February 2012

Work Ability Index (WAI) and Its Association with Psychosocial Factors in One of the Petrochemical Industries in Iran: Adel MAZLOUMI, et al. Department of Occupational Health, School of Public Health, Tehran University of Medical Sciences, Iran—

Objectives

In recent decades, work ability index (WAI) has been a common practical tool to measure individuals' work ability in many European, Asian and South American countries. However, there is no study concerning work ability in Iran. The aim of this study was to determine the work ability index in an Iranian petrochemical job setting and to examine its relationship with psychosocial factors.

Methods

A cross‐sectional study was conducted among 420 male workers in various occupations. Work ability was evaluated using the WAI questionnaire developed by FIOH; the Job content questionnaire (JCQ) was used to assess psychosocial factors.

Results

The mean WAI score was 39.1 (SD=5.7) among workers in the studied petrochemical industry. Multiple linear regression analysis revealed a significant association between mean WAI score and age, job tenure, educational level, rest and sleep status and vocational education. Moreover, the results showed that skill discretion, coworker support and supervisor support were positively associated with the mean WAI score. On the other hand, it was inversely associated with job demands, job strain and job insecurity.

Conclusions

This study was the first research to determine WAI in an important industry in Iran. Overall, work ability was in the “Good” category among the workers in the studied field. On the basis of the WAI guidelines, this level should be maintained and promoted to excellent level by providing supportive countermeasures. The WAI score was significantly associated with psychosocial factors. The results showed that even in heavy physical work, factors such as job insecurity, skill discretion, job strain and social support play an important role in maintaining work ability. A positive combination of “psychosocial characteristics” of the job with “individual resources” can promote work ability in such occupations.
Quality Measures for Primary Care of Complex Pediatric Patients
Authors: Chen Alex Y. , Schrager Sheree M. , Mangione-Smith Rita
Published: February 2012

OBJECTIVES:

A well-recognized gap exists in assessing and improving the quality of care for medically complex patients. Our objective was to examine evidence for primary care based on the patient-centered medical home model and to identify valid and meaningful quality measures for use in complex pediatric patients.

METHODS:

We conducted literature searches on Medline and the National Quality Measures Clearinghouse for existing measures, as well as evidence to inform the development of new quality measures. We used a 3-step process to select relevant sources from published literature: (1) the titles were screened by 2 independent reviewers; (2) the abstracts were reviewed for quality-of-care contents or constructs; and (3) full-text articles were obtained and reviewed for measure specification. All materials were reviewed for the Oxford Centre For Evidence-Based Medicine level of evidence and for relevance to primary care of complex pediatric patients. A national expert panel was convened to evaluate and rate the measures by using the Rand/University of California Los Angeles Appropriateness Method.

RESULTS:

We presented 74 quality measures to the expert panel for review and discussion. The panel rated and accepted 35 measures as valid and feasible for assessing primary care quality in complex pediatric patients. The final set of quality measures was grouped in the following domains: primary care–general (14), patient/family-centered care (8), chronic care (2), coordination of care (9), and transition of care (2).

CONCLUSIONS:

By using the patient-centered medical home framework of accessible, continuous, family-centered, coordinated, and culturally effective care, a national expert panel selected 35 primary care quality measures for complex pediatric patients.
Nonconvulsive Status Epilepticus: The Encephalopathic Pediatric Patient
Authors: Greiner Hansel M. , Holland Katherine , Leach James L. , Horn Paul S. , Hershey Andrew D. , Rose Douglas F.
Published: February 2012

OBJECTIVE:

A high prevalence of nonconvulsive status epilepticus (NCSE) has been reported in critically ill adults and neonates. Recent prospective pediatric studies focus on critically ill children and show wide variability in the frequency of NCSE. This study examines prevalence of pediatric NCSE regardless of inpatient setting and retrospectively identifies risk factors indicating a need for urgent continuous EEG.

METHODS:

Medical records from patients aged 3 months to 21 years were identified either by (1) searching a clinical EEG database (n = 18) or (2) consecutive inpatient EEG referrals for NCSE over an 8-month period (n = 57).

RESULTS:

Seventy-five children, mean age of 7.8 years, were studied. NCSE was identified in 26 patients (35%) and in 8 of 57 (14%) patients referred for possible NCSE. More than half of the patients referred were outside of the ICU. A witnessed clinical seizure was observed in 24 of 26 (92%) patients with NCSE. Acute cortical neuroimaging abnormalities were significantly more frequent in patients with NCSE. The presence of clinical seizures and acute neuroimaging abnormality was associated with an 82% probability of NCSE. All but 1 patient with NCSE had electrographic or electroclinical seizures within the first hour of monitoring.

CONCLUSIONS:

A high prevalence of NCSE was observed, comparable to adult studies, but within a wider range of inpatient settings. Children with acute encephalopathy should undergo continuous EEG. This evaluation is more urgent if certain clinical risk factors are present. Optimal duration of monitoring and the effect of NCSE on prognosis should be studied.
Trends in Computed Tomography Utilization in the Pediatric Emergency Department
Authors: Menoch Margaret J. A. , Hirsh Daniel A. , Khan Naghma S. , Simon Harold K. , Sturm Jesse J.
Published: February 2012

OBJECTIVE:

The purpose of this study was to determine the overall trend of computed tomography (CT) utilization in the pediatric emergency department (PED) from 2003 to 2010 and to determine trends categorized by common chief complaints.

METHODS:

Electronic chart records at 2 tertiary care PEDs within a large pediatric health care system were reviewed from January 2003 through December 2010. The annual CT utilization rate, by anatomic location, was determined. Annual CT utilization rates were compared with alternative imaging trends for visits with chief complaints of head injury, seizure, and abdominal pain. Analysis was performed with linear regression.

RESULTS:

There was no change in overall CT utilization from 2003 to 2010 (β 0.25, 95% confidence interval [CI] [−1.61 to 2.73]) or within anatomic subgroups. Head CT utilization for the chief complaints of seizure (β −0.97, 95% CI [−1.44 to −0.90]) and head injury (β −0.93, 95% CI [−1.71 to −0.73]) showed significant declines. Although there was no change in the abdominal CT utilization rate for abdominal pain, abdominal ultrasound utilization for abdominal pain significantly increased (β 0.89, 95% CI [0.25–0.79]).

CONCLUSIONS:

Our data showed no overall increase in CT utilization through 2010. In areas where alternative non–radiation-based modalities were options, there were decreased CT trends and increased use of potential alternative non–radiation-based modalities. This is the first large PED cohort study to show a decrease in CT utilization in recent years in a regional pediatric referral center and may correlate with increased awareness of radiation risk in children.
The establishment of the Marfan syndrome biobank in Hungary
Authors: Ágota Annamária , Ágg Bence , Benke Kálmán , Joó József Gábor , Langmár Zoltán , Marosi Krisztina , Lelovics Zsuzsanna , Deé Kitti , Nagy Péter , Köles Bernadett , Horváth Endre , Crespo Zsuzsanna , Szabolcs Zoltán , Nagy Zsolt B.
Published: February 2012

Marfan syndrome is a genetic disorder of the connective tissue, which affects approximately 2000–3000 individuals in Hungary. Given its multi-systemic manifestations, this disorder is often difficult to diagnose. To date, the National Marfan Register system contains approximately 250 cases, and this number is dynamically increasing. Aims: Collection of data from biological samples, clinical parameters, and lifestyle factors in Hungarian patients with Marfan syndrome. Methods: In terms of the criteria used for selection, those cases were chosen where the disorder could be clearly diagnosed on the basis of the patients’ cardiovascular and systemic symptoms, as well as of their family history, in line with the guidelines set by the Revised Ghent Nosology. Results: For the purposes of developing the biobank used for the research, 102 cases were selected from the Marfan Register (cDNA from 55 patients, genomic DNA and serum from 102 patients). In addition to the samples, data have been obtained by using internationally validated surveys to further examine the role of physical activity, nutrition and various psychological factors. Conclusions: The establishment of the Marfan Biobank enables scientists to effectively carry out research based on genetic, gene-expression and protein analysis. The biobank also provides new opportunities to study Hungarian patients with Marfan syndrome. Orv. Hetil., 2012, 153, 296–302.
Small (<2.5 micron) particulate matter concentration of ambient air and early death in Hungary
Authors: Losonczy György
Published: February 2012

The small (<2.5 micron) particulate matter concentration of ambient air is constantly measured and estimated over Europe, based on the recommendations of the WHO and the Council of Europe. Concentration of small size particulate matter has been found to be very high in Central and Eastern Europe, including central and eastern regions of Hungary. Epidemiologic evidence indicates strong direct correlation between small size particulate matter pollution and incidences of cardiopulmonary disease and lung cancer. As compared to Slovakia or the Czech Republic and after correction for population size, Hungary has the highest number of years of life lost due to small size particulate matter pollution related cardiopulmonary disease and lung cancer. Orv. Hetil., 2012, 153, 285–288.
Effect of Ce4+ and Th4+ Ion Substitution in Uranium Dioxide
Authors: Behera Rakesh K. , Deo Chaitanya S.
Published: February 2012

Uranium dioxide is the most common fuel used in commercial light water nuclear reactors. The fission of the fuel generates fission products (FPs) and minor actinides (MAs), which affects the thermo-physical properties of the fuel. The understanding of the physical and chemical properties of the FPs and MAs is still limited. In this study we have used atomic level simulations to estimate the effect of Ce4+ and Th4+ ions in urania matrix. Our results show that the structural variation depends on the elastic effect, which is guided by the ionic radius of the substituted ion. Ce4+ (ionic radius 0.97 Å) reduces the overall lattice parameter, while Th4+ (ionic radius 1.05 Å) increases the overall lattice parameter of the urania matrix (U4+ ionic radius 1.00 Å). In addition bulk modulus of the U1-xCexO2 system does not change with substitution while the modulus of U1-xThxO2 reduces with an increase in Th4+ ion concentration. This observation is in accordance with Vegard’s law prediction based on the modulus values of bulk UO2, CeO2 and ThO2 systems.
Emergence of blue emission with decreasing film thickness and grain size for ZnO grown via thermal oxidation of Zn-metal films
Authors: Covington L.R. , Stansell R. , Moore J.C.
Published: February 2012

We have investigated the photoluminescence properties of ZnO grown on sapphire substrates via the thermal oxidation of Zn-metal films at various temperatures and thicknesses. X-ray diffraction (XRD) spectra indicate that the resulting films possess a polycrystalline hexagonal wurtzite structure without preferred orientation. For films having a thickness of 200 nm, crystal grain size was observed to decrease with increasing annealing temperature up to 600ºC, and then increase at higher temperatures. Thicker films demonstrated a modest increase in grain size as temperature increased from 300ºC to 1200ºC. The influence of film thickness on the optical properties was investigated using room temperature photoluminescence (PL). Specifically, PL spectra indicate four emission bands: excitonic ultraviolet, blue, and deep-level green and yellow emission. The strongest UV emission and narrowest full width at half maximum (0.09 eV) was observed for films having a thickness of 200 nm and annealed at low temperature (300ºC). As film thickness decreased, we observed the emergence of blue emission. The emergence of blue emission when depletion width grows relative to the bulk suggests that the origin of the blue emission is related to the negatively charged Zinc interstitials found within the deletion region near the interface.
Synthesis of 3,7-Dialkylthieno[2’,3’:4,5]thieno[3,2-b]thieno[2,3-d]thiophenes (DCnFT4) and their Application in Semi-conducting Polymers
Authors: Hu Jieyu , Matthews James R. , He Mingqian
Published: February 2012

Recently much interest has been directed toward solution processable polymeric semi-conductor materials containing thiophene based moieties.[1] In particular, dialkylated tetrathienoacene (fused thiophene) copolymers have been used as high mobility semiconductors in field-effect transistors with a field-effect hole mobility exceeding 0.3 cm2/Vs.[2] Expansion of this class of materials to include new materials with either linear (DCnFT4) or branched (DbCnFT4) di-alkyl-substituted fused thiophenes has been achieved with the development of two distinct synthetic routes for ring formation and the introduction of the side-chains.

DC17FT4 was prepared from tetrabromothieno[3,2-b]thiophene through a sequence of diketone formation, cyclization, hydrolysis and decarboxylation. Synthesis of the new compound di-2,4,4-trimethylpentyl-FT4 (DbC8FT4) has been accomplished in a more complex 8 step process, featuring a mono-ketone-ester as a key intermediate.

DCnFT4 can be brominated in the 2- and 6-positions with NBS. The dibromide can then be used to form copolymers through cross coupling reactions. These polymers are solution processable semi-conductors. The polymers have been characterized by GPC and within organic thin-film transistor (OTFT) devices.
Experimental Strategy for High Throughput Materials Development
Authors: Cawse James N.
Published: February 2012

Successful experimental strategy in the high throughput world requires coordination of the statistical planning of the experimental program with the optimization of the workflow for efficient use of robotic workstation resources.
Alterações cognitivas em indivíduos brasileiros com esclerose múltipla surto-remissão
Authors: Negreiros Marco Aurélio , Landeira-Fernandez Jesus , Kirchmeyer Cíntia Villela , Paes Renata Alves , Alvarenga Regina , Mattos Paulo
Published: February 2012

Objetivo: O objetivo deste estudo é investigar o perfil neuropsicológico de uma amostra de pacientes brasileiros com esclerose múltipla surto-remissão (EMSR), descrevendo as funções cognitivas mais comprometidas. Métodos: Cinquenta e quatro pacientes com EMSR e 54 controles pareados por sexo, idade e nível educacional foram avaliados por meio de uma longa e abrangente bateria neuropsicológica. Resultados: Observou-se que 59,2% dos pacientes com EMSR apresentaram algum tipo de comprometimento cognitivo em comparação com o grupo controle. Os testes neuropsicológicos identificaram disfunções executivas, da memória de longo prazo e da velocidade de processamento de informação. Conclusão: Os resultados encontram-se em conformidade com estudos anteriores relatados na literatura internacional. Contudo, mais estudos ainda são necessários para uma estimativa maior do perfil das alterações cognitivas da esclerose múltipla no Brasil.
Cardio-respiratory symptoms in panic disorder: a contribution from cognitive-behaviour therapy
Authors: King Anna Lucia Spear , Silva Adriana Cardoso de Oliveira e , Valencça Alexandre Martins , Nardi Antonio Egidio
Published: February 2012

Objective: To compare patients with panic disorder with agoraphobia treated with cognitive-behavioural therapy (CBT) associated with the medication with patients treated only with medication and verify the behaviour of the cardio-respiratory symptoms of both groups. Methods: Randomized sample in the Psychiatry Institute of the Federal University of Rio de Janeiro, divided in two groups of 25 participants each. Group 1 undertook 10 weekly sessions of CBT with one hour of duration each together with medication. Group 2, Control, were administered medication that only consisted of tricyclic anti-depressants and selective inhibitors of the re-uptake of serotonin. Evaluation instruments were applied at the beginning and to the end of the interventions. Results: According to the applied scales, group 1 showed statistically more significant results than group 2, with: reduction of panic attacks, cardio-respiratory symptoms, anticipatory anxiety, agoraphobia avoidance and fear of bodily sensations. Conclusion: Exposures (in vivo and interoceptive), especially for induction symptom exercises and relaxation, were considered essential to prepare patients with panic disorder to handle future cardio-respiratory symptoms and panic attacks with agoraphobia.
Body image dissatisfaction and its relationship with physical activity and body mass index in Brazilian adolescents
Authors: Laus Maria F. , Costa Telma M. Braga , Almeida Sebastião S.
Published: February 2012

Objective: To evaluate body image dissatisfaction and its relationship with physical activity and body mass index in a Brazilian sample of adolescents. Methods: A total of 275 adolescents (139 boys and 136 girls) between the ages of 14 and 18 years completed measures of body image dissatisfaction through the Contour Drawing Scale and current physical activity by the International Physical Activity Questionnaire. Weight and height were also measured for subsequent calculation of body mass index. Results: Boys and girls differed significantly regarding body image dissatisfaction, with girls reporting higher levels of dissatisfaction. Underweight and eutrophic boys preferred to be heavier, while those overweight preferred be thinner and, in contrast, girls desired to be thinner even when they are of normal weight. Conclusion: Body image dissatisfaction was strictly related to body mass index, but not to physical activity.
A patogênese genética e molecular da síndrome de Angelman
Authors: Maris Angelica Francesca , Trott Alexis
Published: February 2012

Objetivo: Fornecer uma revisão atualizada em língua portuguesa sobre a síndrome de Angelman, com ênfase nos mecanismos genéticos e moleculares dessa patologia, uma causa de deficiência mental severa que em alguns casos pode apresentar recorrência familiar. Método: Foi feita uma revisão bibliográfica utilizando a base de dados do PubMed, tendo como critérios de busca o termo "Angelman syndrome" isoladamente e combinado com "UBE3A", "clinical", "genetics" e "molecular" no título dos artigos. Dentre esses, foram selecionados artigos de revisão e artigos originais sobre a fisiopatologia da síndrome, com ênfase nos últimos dez anos. Resultados: Utilizando-se "Angelman syndrome" na busca, apareceram cerca de 1.100 artigos, incluindo 240 de revisão. Nos últimos dez anos são mais de 600 artigos, aproximadamente 120 de revisão, 50% dos quais publicados nos últimos cinco anos. Na base de dados SciELO, são apenas nove artigos sobre a síndrome, dos quais três em português e nenhum artigo atual de revisão. Conclusão: Após ter sido uma das principais causas que atraíram atenção ao estudo e ao entendimento dos mecanismos do imprinting genômico, a síndrome de Angelman está agora se revelando como uma patologia das sinapses. Apesar de o entendimento da fisiopatologia molecular da síndrome de Angelman ainda estar longe de ser compreendida, seu estudo está fornecendo uma visão extraordinária sobre os mecanismos que regem a plasticidade sináptica, novamente atraindo a atenção de pesquisadores que trabalham na fronteira do conhecimento.
Posterior Pharyngeal Fat Grafting for Velopharyngeal Insufficiency
Authors: Lau Darryl , Oppenheimer Adam J. , Buchman Steve R. , Berger Mary , Kasten Steven J.
Published: February 2012

Objective

To determine if autologous fat grafting to the posterior pharynx can reduce hypernasality in patients with cleft palate and mild velopharyngeal insufficiency (VPI).

Design

Retrospective case series.

Setting

Tertiary care center.

Patients

Eleven patients with cleft palate status after palatoplasty (with or without secondary speech surgery) with nasendoscopic evidence of VPI.

Interventions

Autologous fat was harvested and injected into the posterior pharynx under general anesthesia.

Main Outcome Measures

Pre- and postoperative subjective, nasometry, and nasendoscopy data. Apnea-hypopnea indices (AHIs) were also assessed. Comparisons were made using Fisher's exact test, Student's t tests, and relative risk (RR) assessments.

Results

An average of 13.1 mL of fat was injected (range: 5 to 22 mL). Mean follow-up was 17.5 months (range: 12 to 25 months). Statistically significant improvements in speech resonance were identified in nasometry (Zoo passage; p = .027) and subjective hypernasality assessment ( p= .035). Eight of the patients (73%) demonstrated normal speech resonance after posterior pharyngeal fat grafting (PPFG) on subjective or objective assessment ( p = .001). All five patients with previous secondary speech surgeries demonstrated normal speech resonance on similar assessment (RR = 1.8; p = .13). Complete velopharyngeal closure was observed in seven patients on postoperative nasendoscopy. No changes in AHIs were observed ( p=.581).

Conclusion

PPFG may be best used as an adjunct to secondary speech surgery. In this series, PPFG was not accompanied by the negative sequelae of hyponasality, sleep apnea, or airway compromise.
Benthic–pelagic coupling in lake ecosystems: the key role of chironomid pupae as prey of pelagic fish
Authors: Wagner A. , Volkmann S. , Dettinger-Klemm P. M. A.
Published: February 2012

Studies of lake ecosystems have often treated benthic and pelagic habitats as discrete food chains with parallel, separated compartments. A limited number of studies on the importance of fish feeding for benthic‐pelagic coupling have been conducted with a food‐web perspective of lakes. We hypothesize that pelagic fish couple benthic and pelagic food webs by feeding on chironomid pupae ascending from the sediment to the surface. Over a two‐year period, an analysis of the stomach contents of Eurasian perch (Perca fluviatilis L.) was combined with simultaneous catches of chironomids in near‐bottom pupal traps and floating emergence traps exposed in the littoral and profundal region of a deep temperate reservoir. Chironomid larvae rarely served as prey for perch. While chironomid pupae from the littoral region were of minor importance as perch prey, we determined a substantial vertical trophic biomass transfer from the profundal to the pelagic food web for the pupation peak of profundal chironomids from May through June. During this period, chironomid pupae represented approximately 20–48% of the ingested biomass of all size classes of perch (70–340 mm). The pupae of only three large profundal species out of 84 chironomid taxa detected in the reservoir represented approximately 80% of the chironomids consumed by perch, indicating a key role for these taxa in benthic‐pelagic coupling. The strong influences of species, habitat and size on the consumption of chironomid pupae by the pelagic perch provide the importance of detecting key benthic species that substantially contribute to the pelagic food web. The phenology of profundal species results in a seasonal shift in the feeding behavior of pelagic fish, which thereby influences the trophic dynamics of lake ecosystems. Therefore, we argue for a more integrated view of lake ecosystems that recognizes not only the littoral but also the complementarity of profundal and pelagic production pathways crucial for ecosystem functioning.
Quantifying animal phenology in the aerosphere at a continental scale using NEXRAD weather radars
Authors: Kelly Jeffrey F. , Shipley J. Ryan , Chilson Phillip B. , Howard Kenneth W. , Frick Winifred F. , Kunz Thomas H.
Published: February 2012

One of the primary ecological manifestations of climate change is a shift in the timing of events in a species' annual cycle. Such phenological shifts have been documented in numerous taxa, but data for animals have been derived primarily from human observers rather than networks of instruments used for remote sensing. The potential to use the network of weather radars in the United States (NEXRAD) to remotely sense animal phenologies could advance our understanding of the spatiotemporal scaling of phenologies in relation to shifts in local and regional climate. We tested the utility of NEXRAD radar products for quantifying the phenology of the purple martin (Progne subis) at summer roost sites in the United States. We found that the maximum radar reflectivity value in the hour before local sunrise above purple martin roost sites contained a strong phenological signal of significantly increased radar reflectivity during June, July, and August 2010. The seasonal pattern in this radar signal matched our expectation of the timing of formation and dissipation of these seasonal roosts. Radar reflectivity was greater and less variable when considering roosts close to NEXRAD stations (<25 km) than when including all 358 documented roosts; there was a negative relationship between maximum reflectivity and the distance between a roost and the nearest NEXRAD. Our results suggest that: (1) mosaicked NEXRAD radar products are a valuable source of information on the phenology of bioscatter in the aerosphere; (2) citizen scientists who document the locations of roosts on the ground are providing critical information for advancing our understanding of animal phenology and aeroecology; and (3) ongoing research that examines spatiotemporal relationships among radar‐derived phenologies in airborne organisms, climate, and land cover change are likely to provide further insights.
Early‐warning signals (potentially) reduce uncertainty in forecasted timing of critical shifts
Authors: Karssenberg Derek , Bierkens Marc F. P.
Published: February 2012

Despite the identification of early‐warning signals precluding ecosystems regime shifts, limited evidence exists that they can be used to forecast the actual timing of a critical shift. Here, we propose a probabilistic Bayesian approach to forecast the timing of a shift by combining uncertain prior information about the ecosystem dynamics (parameters and drivers) and sampled spatial and temporal correlation and variance of ecosystem states, which are well known early‐warning signals. For an ecosystem of logistically growing vegetation under linear increase in grazing pressure, we show that the use of sampled early‐warning signals results in lower prediction uncertainty in forecasted timing of shifts compared to forecasts made with sampled mean state variables. In addition, we show that uncertainty in ecosystem parameters decreases well ahead of a shift. An important conclusion of our study is that the use of early‐warning signals in forecasting of shifts is promising, provided that a large number of samples are collected (n ≈ 104 in our study). This explains the limited success of finding early warning signals from field studies of real world ecosystems.
Teaching, Learning, and Collaborating in the Cloud: Applications of Cloud Computing for Educators in Post-Secondary Institutions
Authors: Aaron Lynn S. , Roche Catherine M.
Published: February 2012

“Cloud computing” refers to the use of computing resources on the Internet instead of on individual personal computers. The field is expanding and has significant potential value for educators. This is discussed with a focus on four main functions: file storage, file synchronization, document creation, and collaboration—each of which has applications for educators. Cloud-based application suites such as Google Apps, Zoho, and Microsoft Office 365 are important tools. In addition, web-based tools such as Google Scholar and Zotero can enhance the learning and research experience. This discussion is enriched by the results of a survey of 80 faculty members delivered in May 2011. The respondents fell into two groups—those who currently use cloud computing and those who do not. Results reveal the areas of interest, future projections, and the concerns of both groups.
Technology and Teaching Philosophy
Authors: King Paul C.
Published: February 2012

This article discusses the challenges faced when integrating new technologies into the classroom. Viewing the experiences of teaching a first year learning community through the lens of the principles of the Reflective Teaching Portfolio, the author looks to answer the question: How should Technology relate to our Teaching Philosophy? While a proponent of testing and integrating new technologies into the classroom, the author also recognizes that we learn more from our mistakes than from our successes and that if a tool does not fit with our Teaching Philosophy, then we should not use it. This article provides an honest assessment of recent experiences integrating online learning technologies into the classroom and makes suggestions on how to develop a successful approach.