bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rapid mapping of visual receptive fields by filtered back projection: application to multi‐neuronal electrophysiology and imaging
Authors: Johnston Jamie , Ding Huayu , Seibel Sofie H. , Esposti Federico , Lagnado Leon 
Published: August 2014

Key pointsTo understand vision, we must measure the spatio‐temporal receptive field of neurons in the visual system.We describe how the filtered back projection can be used to map the receptive fields of many neurons simultaneously, within a few minutes.This method can also reveal complex features of visual receptive fields such as the tuning of orientation selective neurons and the contributions from separate ON and OFF components.We demonstrate that the filtered back projection is suited to mapping receptive fields from populations of neurons recorded with imaging or electrophysiology and should therefore prove useful for investigations of visual processing throughout the visual pathway.AbstractNeurons in the visual system vary widely in the spatiotemporal properties of their receptive fields (RFs), and understanding these variations is key to elucidating how visual information is processed. We present a new approach for mapping RFs based on the filtered back projection (FBP), an algorithm used for tomographic reconstructions. To estimate RFs, a series of bars were flashed across the retina at pseudo‐random positions and at a minimum of five orientations. We apply this method to retinal neurons and show that it can accurately recover the spatial RF and impulse response of ganglion cells recorded on a multi‐electrode array. We also demonstrate its utility forin vivoimaging by mapping the RFs of an array of bipolar cell synapses expressing a genetically encoded Ca2+indicator. We find that FBP offers several advantages over the commonly used spike‐triggered average (STA): (i) ON and OFF components of a RF can be separated; (ii) the impulse response can be reconstructed at sample rates of 125 Hz, rather than the refresh rate of a monitor; (iii) FBP reveals the response properties of neurons that are not evident using STA, including those that display orientation selectivity, or fire at low mean spike rates; and (iv) the FBP method is fast, allowing the RFs of all the bipolar cell synaptic terminals in a field of view to be reconstructed in under 4 min. Use of the FBP will benefit investigations of the visual system that employ electrophysiology or optical reporters to measure activity across populations of neurons.
Wiring patterns in the mouse retina: collecting evidence across the connectome, physiology and light microscopy
Authors: Dunn Felice A. , Wong Rachel O. L. 
Published: August 2014

AbstractThe visual system has often been thought of as a parallel processor because distinct regions of the brain process different features of visual information. However, increasing evidence for convergence and divergence of circuit connections, even at the level of the retina where visual information is first processed, chips away at a model of dedicated and distinct pathways for parallel information flow. Instead, our current understanding is that parallel channels may emerge, not from exclusive microcircuits for each channel, but from unique combinations of microcircuits. This review depicts diagrammatically the current knowledge and remaining puzzles about the retinal circuit with a focus on the mouse retina. Advances in techniques for labelling cells and genetic manipulations have popularized the use of transgenic mice. We summarize evidence gained from serial electron microscopy, electrophysiology and light microscopy to illustrate the wiring patterns in mouse retina. We emphasize the need to explore proposed retinal connectivity using multiple methods to verify circuits both structurally and functionally.
Ionotropic GABA and glycine receptor subunit composition in human pluripotent stem cell‐derived excitatory cortical neurones
Authors: James Owain T. , Livesey Matthew R. , Qiu Jing , Dando Owen , Bilican Bilada , Haghi Ghazal , Rajan Rinku , Burr Karen , Hardingham Giles E. , Chandran Siddharthan , Kind Peter C. , Wyllie David J. A. 
Published: August 2014

Key points
This study reports a functional assessment of the subunit composition of inhibitory ionotropic GABAA receptors (GABAARs) and glycine receptors (GlyRs) expressed by excitatory cortical neurones derived from human embryonic stem cells (hECNs).
GABAARs expressed by hECNs are predominantly composed of α2/3β3γ2 subunits; such a composition is typical of that reported for GABAARs expressed in rodent embryonic cortex.
Analysis of GlyRs expressed by hECNs indicates they are likely to contain α2 and β subunits – a composition in rodents that is associated with a late embryonic/early postnatal period of development.
AbstractWe have assessed, using whole‐cell patch‐clamp recording and RNA‐sequencing (RNA‐seq), the properties and composition of GABAA receptors (GABAARs) and strychnine‐sensitive glycine receptors (GlyRs) expressed by excitatory cortical neurons derived from human embryonic stem cells (hECNs). The agonists GABA and muscimol gave EC50 values of 278 μm and 182 μm, respectively, and the presence of a GABAAR population displaying low agonist potencies is supported by strong RNA‐seq signals for α2 and α3 subunits. GABAAR‐mediated currents, evoked by EC50 concentrations of GABA, were blocked by bicuculline and picrotoxin with IC50 values of 2.7 and 5.1 μm, respectively. hECN GABAARs are predominantly γ subunit‐containing as assessed by the sensitivity of GABA‐evoked currents to diazepam and insensitivity to Zn2+, together with the weak direct agonist action of gaboxadol; RNA‐seq indicated a predominant expression of the γ2 subunit. Potentiation of GABA‐evoked currents by propofol and etomidate and the lack of inhibition of currents by salicylidine salycylhydrazide (SCS) indicate expression of the β2 or β3 subunit, with RNA‐seq analysis indicating strong expression of β3 in hECN GABAARs. Taken together our data support the notion that hECN GABAARs have an α2/3β3γ2 subunit composition – a composition that also predominates in immature rodent cortex. GlyRs expressed by hECNs were activated by glycine with an EC50 of 167 μm. Glycine‐evoked (500 μm) currents were blocked by strychnine (IC50 = 630 nm) and picrotoxin (IC50 = 197 μm), where the latter is suggestive of a population of heteromeric receptors. RNA‐seq indicates GlyRs are likely to be composed of α2 and β subunits.
Angiotensin II mobilizes intracellular calcium and activates pannexin‐1 channels in rat carotid body type II cells via AT1 receptors
Authors: Murali Sindhubarathi , Zhang Min , Nurse Colin A. 
Published: August 2014

Key points
A locally generating, angiotensin II (ANG II) system is present in the rat carotid body (CB) and up‐regulation of this system occurs in certain pathophysiological situations, enhancing sympathetic activity.
Here, we show that, similar to chemoreceptor type I cells, glial‐like type II cells also express functional AT1Rs, stimulation of which causes release of Ca2+ from intracellular stores.
ANG II–AT1R signalling in type II cells activates an inward current carried by pannexin‐1 (Panx‐1) channels which are known to act as conduits for release of ATP, a key CB excitatory neurotransmitter.
Combined effects of ANG II and ATP, which also activates Panx‐1 currents via P2Y2 receptors, were synergistic; chelating intracellular Ca2+ with BAPTA prevented Panx‐1 current activation.
We propose that the excitatory function of ANG II in the CB involves dual actions at both type I and type II cells.
AbstractA local angiotensin‐generating system is present in the carotid body (CB) and increased angiotensin II (ANG II) signalling contributes to enhanced CB excitation in chronic heart failure (CHF) and after chronic or intermittent hypoxia. ANG II actions have thus far been attributed solely to stimulation of AT1 receptors (AT1Rs) on chemoreceptor type I cells. Here, we show that in dissociated rat CB cultures, ANG II also stimulates glial‐like type II cells, identified by P2Y2‐receptor‐induced intracellular Ca2+ elevation (Δ[Ca2+]i). ANG II induced a dose‐dependent (EC50 ∼8 nm), robust Δ[Ca2+]i in type II cells that was reversibly abolished by the AT1R blocker losartan (1 μm). The ANG II‐induced Δ[Ca2+]i persisted in Ca2+‐free medium but was sensitive to store depletion with cyclopiazonic acid (1 μm). Similar to P2Y2 receptor agonists, ANG II (20–1000 nm) activated pannexin‐1 (Panx‐1) current that was reversibly abolished by carbenoxolone (5 μm). This current arose with a variable delay and was reversibly inhibited by losartan. Repeated application of ANG II often led to current run‐down, attributable to AT1R desensitization. When applied to the same cell the combined actions of ANG II and ATP on Panx‐1 current were synergistic. Current induced by either ligand was inhibited by BAPTA‐AM (1 μm), suggesting that intracellular Ca2+ signalling contributed to Panx‐1 channel activation. Because open Panx‐1 channels release ATP, a key CB excitatory neurotransmitter, it is plausible that paracrine stimulation of type II cells by ANG II contributes to enhanced CB excitability, especially in pathophysiological conditions such as CHF and sleep apnoea.
Consistency of Commercial Devices for Measuring Elevation Gain
Authors: Menaspà Paolo , Impellizzeri Franco M. , Haakonssen Eric C. , Martin David T. , Abbiss Chris R. 
Published: August 2014

Purpose:To determine the consistency of commercially available devices used for measuring elevation gain in outdoor activities and sports.Methods:Two separate observational validation studies were conducted. Garmin (Forerunner 310XT, Edge 500, Edge 750, and Edge 800; with and without elevation correction) and SRM (Power Control 7) devices were used to measure total elevation gain (TEG) over a 15.7-km mountain climb performed on 6 separate occasions (6 devices; study 1) and during a 138-km cycling event (164 devices; study 2).Results:TEG was significantly different between the Garmin and SRM devices (P < .05). The between-devices variability in TEG was lower when measured with the SRM than with the Garmin devices (study 1: 0.2% and 1.5%, respectively). The use of the Garmin elevation-correction option resulted in a 5–10% increase in the TEG.Conclusions:While measurements of TEG were relatively consistent within each brand, the measurements differed between the SRM and Garmin devices by as much as 3%. Caution should be taken when comparing elevation-gain data recorded with different settings or with devices of different brands.
Accuracy of Indirect Estimation of Power Output From Uphill Performance in Cycling
Authors: Millet Grégoire P. , Tronche Cyrille , Grappe Frédéric 
Published: August 2014

Purpose:To use measurement by cycling power meters (Pmes) to evaluate the accuracy of commonly used models for estimating uphill cycling power (Pest). Experiments were designed to explore the influence of wind speed and steepness of climb on accuracy of Pest. The authors hypothesized that the random error in Pest would be largely influenced by the windy conditions, the bias would be diminished in steeper climbs, and windy conditions would induce larger bias in Pest.Methods:Sixteen well-trained cyclists performed 15 uphill-cycling trials (range: length 1.3–6.3 km, slope 4.4–10.7%) in a random order. Trials included different riding position in a group (lead or follow) and different wind speeds. Pmes was quantified using a power meter, and Pest was calculated with a methodology used by journalists reporting on the Tour de France.Results:Overall, the difference between Pmes and Pest was –0.95% (95%CI: –10.4%, +8.5%) for all trials and 0.24% (–6.1%, +6.6%) in conditions without wind (>2 m/s). The relationship between percent slope and the error between Pest and Pmes were considered trivial.Conclusions:Aerodynamic drag (affected by wind velocity and orientation, frontal area, drafting, and speed) is the most confounding factor. The mean estimated values are close to the power-output values measured by power meters, but the random error is between ±6% and ±10%. Moreover, at the power outputs (>400 W) produced by professional riders, this error is likely to be higher. This observation calls into question the validity of releasing individual values without reporting the range of random errors.
Neuromuscular Electrical Stimulation: No Enhancement of Recovery From Maximal Exercise
Authors: Malone John K. , Blake Catherine , Caulfield Brian 
Published: August 2014

Purpose:To investigate the use of neuromuscular electrical stimulation (NMES) during acute recovery between 2 bouts of maximal aerobic exercise.Methods:On 3 separate days, 19 trained male cyclists (28 ± 7 y, 76.4 ± 10.4 kg, power output at maximal aerobic power [pVo2max] 417 ± 44 W) performed a 3-min maximal cycling bout at 105% PVo2max before a 30-min randomly assigned recovery intervention of passive (PAS: resting), active (ACT: 30% PVo2max), or NMES (5 Hz, 4 pulses at 500 μs). Immediately afterward, a cycle bout at 95% PVo2max to exhaustion (TLIM) was performed. Heart rate (HR) and blood lactate (BLa) were recorded at designated time points. Data were analyzed using repeated-measures ANOVA with a Tukey honestly significantly different post hoc test. Statistical significance threshold was P < .05.Results:The TLIM was significantly shorter for NMES than for ACT (199.6 ± 69.4 s vs 250.7 ± 105.5 s: P = .016) but not PAS recovery (199.6 ± 69.4 s vs 216.4 ± 77.5 s: P = .157). The TLIM was not significantly different between ACT and PAS (250.7 ± 105.5 s vs 216.4 ± 77.5 s: P = .088). The decline in BLa was significantly greater during ACT than NMES and PAS recovery (P < .001), with no difference between NMES and PAS. In addition, HR was significantly higher during ACT than NMES and PAS recovery (P < .001), with no difference between NMES and PAS.Conclusions:NMES was less effective than ACT and comparable to PAS recovery when used between 2 bouts of maximal aerobic exercise in trained male cyclists.
Comparison of Athlete–Coach Perceptions of Internal and External Load Markers for Elite Junior Tennis Training
Authors: Murphy Alistair P. , Duffield Rob , Kellett Aaron , Reid Machar 
Published: August 2014

Purpose:To investigate the discrepancy between coach and athlete perceptions of internal load and notational analysis of external load in elite junior tennis.Methods:Fourteen elite junior tennis players and 6 international coaches were recruited. Ratings of perceived exertion (RPEs) were recorded for individual drills and whole sessions, along with a rating of mental exertion, coach rating of intended session exertion, and athlete heart rate (HR). Furthermore, total stroke count and unforced-error count were notated using video coding after each session, alongside coach and athlete estimations of shots and errors made. Finally, regression analyses explained the variance in the criterion variables of athlete and coach RPE.Results:Repeated-measures analyses of variance and interclass correlation coefficients revealed that coaches significantly (P < .01) underestimated athlete session RPE, with only moderate correlation (r = .59) demonstrated between coach and athlete. However, athlete drill RPE (P = .14; r = .71) and mental exertion (P = .44; r = .68) were comparable and substantially correlated. No significant differences in estimated stroke count were evident between athlete and coach (P = .21), athlete notational analysis (P = .06), or coach notational analysis (P = .49). Coaches estimated significantly greater unforced errors than either athletes or notational analysis (P < .01). Regression analyses found that 54.5% of variance in coach RPE was explained by intended session exertion and coach drill RPE, while drill RPE and peak HR explained 45.3% of the variance in athlete session RPE.Conclusion:Coaches misinterpreted session RPE but not drill RPE, while inaccurately monitoring error counts. Improved understanding of external- and internal-load monitoring may help coach–athlete relationships in individual sports like tennis avoid maladaptive training.
Draft Genome Sequence of the Fish Pathogen Yersinia ruckeri Strain 37551, Serotype O1b, Isolated from Diseased, Vaccinated Atlantic Salmon (
Salmo salar
) in Chile
Authors: Navas Esteban , Bohle Harry , Henríquez Patricio , Grothusen Horst , Bustamante Fernando , Bustos Patricio , Mancilla Marcos 
Published: August 2014

ABSTRACT

We sequenced the genome of a motile O1b
Yersinia ruckeri
field isolate from Chile, which is causing enteric redmouth disease (ERM) in vaccinated Atlantic salmon (
Salmo salar
). The draft genome has 3,775,486 bp, a G+C content of 47.1%, and is predicted to contain 3,406 coding sequences.
How does under-reporting of negative and inconclusive results affect the false-positive rate in meta-analysis? A simulation study
Authors: Kicinski Michal 
Published: August 2014

ObjectiveTo investigate the impact of a higher publishing probability for statistically significant positive outcomes on the false-positive rate in meta-analysis.DesignMeta-analyses of different sizes (N=10, N=20, N=50 and N=100), levels of heterogeneity and levels of publication bias were simulated.Primary and secondary outcome measuresThe type I error rate for the test of the mean effect size (ie, the rate at which the meta-analyses showed that the mean effect differed from 0 when it in fact equalled 0) was estimated. Additionally, the power and type I error rate of publication bias detection methods based on the funnel plot were estimated.ResultsIn the presence of a publication bias characterised by a higher probability of including statistically significant positive results, the meta-analyses frequently concluded that the mean effect size differed from zero when it actually equalled zero. The magnitude of the effect of publication bias increased with an increasing number of studies and between-study variability. A higher probability of including statistically significant positive outcomes introduced little asymmetry to the funnel plot. A publication bias of a sufficient magnitude to frequently overturn the meta-analytic conclusions was difficult to detect by publication bias tests based on the funnel plot. When statistically significant positive results were four times more likely to be included than other outcomes and a large between-study variability was present, more than 90% of the meta-analyses of 50 and 100 studies wrongly showed that the mean effect size differed from zero. In the same scenario, publication bias tests based on the funnel plot detected the bias at rates not exceeding 15%.ConclusionsThis study adds to the evidence that publication bias is a major threat to the validity of medical research and supports the usefulness of efforts to limit publication bias.
Accidents and injuries related to powered paragliding: a cross-sectional study
Authors: Feletti Francesco , Goin Jeff 
Published: August 2014

ObjectivesPowered paragliding (PPG) and paragliding are two totally different sports, mainly because of the use of an engine in powered paragliding. As a consequence, the pattern of injuries caused by each of these two sports may be different.SettingTo test this hypothesis, we analysed 384 incident reports gathered by the US Powered Paragliding Association from 1995 to 2012. The majority of the incidents occurred in the USA, while 26 incidents occurred elsewhere: Canada (8), Mexico (5), Panama (1), China (1), Japan (1), Malaysia (1), Indonesia (Java) (1), Europe (8): of which Spain (1), Belgium (1), UK (3), Italy (1), Romania (1), unknown (1).OutcomeTo identify the most affected body area and the most common type of injury sustained in PPG, and to highlight any differences from paragliding.ResultsThe most affected body areas in PPG were the upper limbs (44.5%), followed by the lower limbs (32%), the back (9.8%), the head (7%), the pelvis (3.1), the chest (2.7%) and the abdomen (0.7%) (p<0.001). The engine caused 43 accidents (11.2%) in our study and was responsible for the majority of injuries to the upper limbs. The number of fatal accidents in PPG is not lower than in paragliding and hang-gliding.ConclusionsTo help prevent the specific injuries of PPG, the most appropriate equipment should be identified. The results of this study also suggest that, in the future, this sport should be analysed separately from paragliding.
Prevalence and risk factors for chronic co-infection in pulmonaryMycobacterium aviumcomplex disease
Authors: Fujita Kohei , Ito Yutaka , Hirai Toyohiro , Kubo Takeshi , Togashi Kaori , Ichiyama Satoshi , Mishima Michiaki 
Published: August 2014

BackgroundPatients with pulmonaryMycobacterium aviumcomplex (MAC) disease are often co-infected with various pathogenic microorganisms. This study aimed to determine the prevalence of co-infection with non-MAC pathogens and the risk factors associated with co-infection in patients with pulmonary MAC disease.MethodsWe retrospectively reviewed the patient characteristics, microbiological results and chest CT findings in 275 patients with pulmonary MAC who visited the Kyoto University Hospital from January 2001 to May 2013. We defined chronic pathogenic co-infection as the isolation of non-MAC pathogens from sputum samples taken on more than two visits that occurred at least 3 months apart.ResultsThe participants were predominantly female (74.5%) and infected withM. avium(75.6%). Chronic co-infection with any pathogen was observed in 124 patients (45.1%). Methicillin-sensitiveStaphylococcus aureus(MSSA; n=64),Pseudomonas aeruginosa(n=35) andAspergillusspp (n=18) were the most prevalent pathogens. The adjusted factors were chronic obstructive pulmonary disease (COPD; OR=4.2, 95% CI 1.6 to 13.1) and pulmonaryM. intracellularedisease (OR=2.2, 95% CI 1.1 to 4.4) in chronic co-infections; COPD (OR=4.2, 95% CI 2.1 to 31.4), long duration of MAC disease (OR=2.2, 95% CI 1.2 to 4.4) and nodules (OR=3.5, 95% CI 1.2 to 13.2) in chronic MSSA co-infection; COPD (OR=7.5, 95% CI 2.1 to 31.4) and lower lobe involvement (OR=9.9, 95% CI 2.0 to 90.6) in chronicP. aeruginosaco-infection; and use of systemic corticosteroids (OR=7.1, 95% CI 1.2 to 50.9) and pulmonaryM. intracellularedisease (OR=4.0, 95% CI 1.1 to 14.5) in chronicAspergillusspp co-infection.ConclusionsPatients with pulmonary MAC disease frequently had chronic co-infections with pathogenic microorganisms such as MSSA,P. aeruginosaandAspergillus. The risk factors for chronic co-infection were COPD and pulmonaryM. intracellularedisease.