bluuebunny/crossref_metadata_2025_split huggingface dataset:
Age, sun and substrate: triggers of bacterial communities in lichens
Authors: Cardinale Massimiliano , Steinová Jana , Rabensteiner Johannes , Berg Gabriele , Grube Martin 
Published: August 2011

SummaryBacterial communities colonize the surfaces of lichens in a biofilm‐like manner. The overall structure of the bacterial communities harboured by the lichens shows similarities, in particular the dominance of not yet cultured Alphaproteobacteria. Parameters causing variation in abundance, composition and spatial organization of the lichen‐associated bacterial communities are so far poorly understood. As a first step, we used a microscopic approach to test the significance of both lichen‐intrinsic and extrinsic environmental factors on the bacterial communities associated with 11 lichen samples, belonging to six species. Some of these species have thalli with a distinct age gradient. A statistically significant effect can be attributed to the age of the thallus parts, which is an intrinsic factor: growing parts of the lichens host bacterial communities that significantly differ from those of the ageing portions of the thalli. The substrate type (rock, tree, understory) and (at a lower extent) the exposition to the sun also affected the bacterial communities. Interestingly, the abundance of bacterial cells in the lichens was also influenced by the same structure‐triggering factors. No effect on the composition with main bacterial groups was attributed to different lichen species, differentiated thallus parts or thallus growth type. Our results are important for the experimental designs in lichen‐bacterial ecology.
Collision tumour affecting the paranasal sinuses of a geriatric donkey
Authors: Witte S. , Mueller P. O. E. , Kosarek C. , Webb J. L. , Howerth E. W. 
Published: August 2011

SummaryTumours of the paranasal sinuses are relatively uncommon in the horse. A collision tumour occurs when 2 separate tumour types arise in close proximity to each other and encroach on one another. This report describes the presence of neoplasia comprising glandular tissue and spindle cells growing concurrently in the frontal and caudal maxillary sinus of a geriatric donkey. As far as the authors are aware, this is the first description of a possible collision tumour in an equid.
Remarks on endomorphisms and rational points
Authors: Amerik E. , Bogomolov F. , Rovinsky M. 
Published: August 2011

AbstractLet X be an algebraic variety and let f:X−−→X be a rational self-map with a fixed point q, where everything is defined over a number field K. We make some general remarks concerning the possibility of using the behaviour of f near q to produce many rational points on X. As an application, we give a simplified proof of the potential density of rational points on the variety of lines of a cubic fourfold, originally proved by Claire Voisin and the first author in 2007.
Acyclovir is a substrate for the human breast cancer resistance protein (BCRP/ABCG2): implications for renal tubular transport and acyclovir-induced nephrotoxicity
Authors: Gunness Patrina , Aleksa Katarina , Koren Gideon 
Published: August 2011

The human breast cancer resistance protein (BCRP/ABCG2) is widely expressed in human tissues, including the kidney. In mice, Bcrp1 (murine BCRP ortholog) mediates the transport of acyclovir into breast milk. It is plausible that acyclovir is also a substrate for the human BCRP. The objective of the study was to determine whether acyclovir is a substrate for human BCRP. Transfected human embryonic kidney (HEK293) cells (containing the wild-type ABCG2 gene) were exposed to [8-14C]acyclovir (1 µmol/L) in the presence or absence of the BCRP inhibitor fumitremorgin C (FTC). Intracellular acyclovir accumulation was assessed using a liquid scintillation counter. Coexposure to FTC resulted in a significant (5-fold) increase in the intracellular accumulation of acyclovir. The results suggest that acyclovir is a substrate for human BCRP. The study is the first to provide direct evidence for the role of human BCRP in acyclovir transport and its potential significance with respect to renal tubular transport of acyclovir and the direct renal tubular insult induced by the drug.
Atrial Remodeling and the Substrate for Atrial Fibrillation in Rat Hearts With Elevated Afterload
Authors: Kim Shang-Jin , Choisy Stéphanie C.M. , Barman Palash , Zhang Haifei , Hancox Jules C. , Jones Sandra A. , James Andrew F. 
Published: August 2011

Background—
Although arterial hypertension and left ventricular hypertrophy are considered good epidemiological indicators of the risk of atrial fibrillation (AF) in patients, the link between elevated afterload and AF remains unclear. We investigated atrial remodeling and the substrate for arrhythmia in a surgical model of elevated afterload in rats.

Methods and Results—
Male Wistar rats (aged 3–4 weeks) were anesthetized and subjected to either partial stenosis of the ascending aorta (AoB) or sham operation (Sham). Experiments were performed on excised hearts 8, 14, and 20 weeks after surgery. Unipolar electrograms were recorded from the left atrial epicardial surface of perfused hearts using a 5×5 electrode array. Cryosections of left atrial tissue were retained for histological and immunocytochemical analyses. Compared to Sham, AoB hearts showed marked left atrial hypertrophy and fibrosis at 14 and 20 weeks postsurgery. The incidence and duration of pacing-induced AF was increased in hearts from AoB rats at 20 weeks postsurgery. The substrate for arrhythmia was associated with reduced vectorial conduction velocity and greater inhomogeneity in conduction but without changes in effective refractory period. Left atrial expression of the gap junction protein, connexin43, was markedly reduced in AoB compared with Sham hearts.

Conclusions—
Using a small-animal model, we demonstrate that elevated afterload in the absence of systemic hypertension results in increased inducibility of AF and left atrial remodeling involving fibrosis, altered atrial connexin43 expression, and marked conduction abnormalities.
Accuracy and Prognostic Value of American Heart Association–Recommended Depression Screening in Patients With Coronary Heart Disease
Authors: Elderon Larkin , Smolderen Kim G. , Na Beeya , Whooley Mary A. 
Published: August 2011

Background—
In 2008, the American Heart Association (AHA) recommended a 2-step screening method, consisting of the 2-item Patient Health Questionnaire (PHQ-2) followed by the 9-item Patient Health Questionnaire (PHQ-9), for identifying depression in cardiovascular patients. The accuracy and prognostic value of this screening method have not been evaluated.

Methods and Results—

We administered the 2-step AHA-recommended screening algorithm to 1024 patients with stable coronary heart disease and calculated sensitivity and specificity against a gold standard interview for major depressive disorder. Subsequent cardiovascular events (myocardial infarction, stroke, transient ischemic attack, heart failure, or death) were determined during a mean of 6.27±2.11 years of follow-up. The AHA-recommended screening method had high specificity (0.91; 95% confidence interval, 0.89 to 0.93) but low sensitivity (0.52; 95% confidence interval, 0.46 to 0.59) for a diagnosis of major depressive disorder. Participants who screened positive on the AHA depression protocol had a 55% greater risk of events than those who screened negative (age-adjusted hazard ratio, 1.55; 95% confidence interval, 1.21 to 1.97;
P
=0.0005). After adjustment for age, sex, body mass index, history of myocardial infarction, hypertension, diabetes, heart failure, and high-density lipoprotein levels, screening positive remained associated with a 41% greater rate of cardiovascular events (hazard ratio, 1.41; 95% confidence interval, 1.10 to 1.81;
P
=0.008).

Conclusions—
Among outpatients with stable coronary heart disease, the AHA-recommended depression screening protocol is highly specific for depression and identifies patients at risk for adverse cardiovascular outcomes.
Characterization of Aircraft Icing Environments with Supercooled Large Drops for Application to Commercial Aircraft Certification
Authors: Cober Stewart G. , Isaac George A. 
Published: August 2011

AbstractObservations of aircraft icing environments that included supercooled large drops (SLD) greater than 100 μm in diameter have been analyzed. The observations were collected by instrumented research aircraft from 134 flights during six field programs in three different geographic regions of North America. The research aircraft were specifically instrumented to accurately measure the microphysics characteristics of SLD conditions. In total 2444 SLD icing environments were observed at 3-km resolution. Each observation had an average liquid water content (LWC) > 0.005 g m−3, drops > 100 μm in diameter, ice crystal concentrations <1 L−1, and an average static temperature ≤0°C. SLD conditions were observed approximately 5% of the in-flight time. The SLD observations were segregated into four subsets, which included conditions with maximum drop sizes <500 μm and >500 μm in diameter, each with median drop volume diameters <40 μm and >40 μm. For each SLD subset, the observations were used to develop envelopes of maximum LWC values as a function of horizontal extent and temperature. In addition, characteristic drop size distributions were developed for each SLD subset. The maximum LWC values physically represent either the 99% or 99.9% LWC values, as determined from an extreme value analysis of the data. The analysis is sufficient for simulation of SLD environments with either numerical icing accretion models or wind-tunnel icing simulations. The SLD envelopes are similar in structure and supplemental to existing aircraft icing envelopes, the difference being that the existing envelopes did not explicitly incorporate SLD conditions.
Wind Speed and Stability Effects on Coupling between Surface Wind Stress and SST Observed from Buoys and Satellite
Authors: O’Neill Larry W. 
Published: August 2011

The surface wind and stress responses to sea surface temperature (SST) are examined using collocated moored buoy and satellite observations in the Gulf Stream and the eastern equatorial Pacific. Using 17 buoy pairs, differences in the wind speed, 10-m equivalent neutral wind speed (ENW), and surface wind stress magnitude between two buoys separated by between 150 and 350 km were all found to be highly correlated to, and satisfy linear relations with, the SST difference on time scales longer than 10 days. This wind–SST coupling is consistent with previous analyses of spatially high-pass-filtered satellite ENW and SST fields. For all buoy pairs, the ENW and wind speed responses to SST differ by only 10%–30%, indicating that the ENW and stress responses to SST are attributable primarily to the response of the actual surface wind speed to SST rather than to stability. This result clarifies the dynamical pathway of the wind–SST coupling on the oceanic mesoscale. This buoy-pair methodology is used further to evaluate the ENW–SST coupling derived from collocated satellite observations of ENW by the Quick Scatterometer (QuikSCAT) and SST by the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) on board the Aqua satellite. Overall, the satellite and buoy ENW responses to SST compare well, with normalized mean differences (satellite minus buoy) of 17% over the Gulf Stream and −31% and 2% over the southern and northern sides of the equatorial Pacific, respectively. Finally, seasonal variability of the large-scale ENW is shown to modulate the wind stress response to SST, whereby stronger winter wind enhances the stress response by a factor of ~2 relative to the ENW response.
The determinants of stroke phenotypes were different from the predictors (CHADS2 and CHA2DS2-VASc) of stroke in patients with atrial fibrillation: a comprehensive approach
Authors: Oh Semi , Kim Suk Jae , Ryu Soo-Kyoung , Kim Gyeong-Moon , Chung Chin Sang , Lee Kwang Ho , Bang Oh Young 
Published: August 2011

Abstract

Background
Atrial fibrillation (AF) is a leading cause of fatal ischemic stroke. It was recently reported that international normalized ratio (INR) levels were associated with infarct volumes. However, factors other than INR levels that affect stroke phenotypes are largely unknown. Therefore, we evaluated the determinants of stroke phenotypes (pattern and volume) among patients with AF who were not adequately anticoagulated.

Methods
We analyzed data pertaining to consecutive AF patients admitted over a 6-year period with acute MCA territory infarcts. We divided the patients according to DWI (diffusion-weighted imaging) lesion volumes and patterns, and the relationship between stroke predictors (the CHADS2 and CHA2DS2-VASc score), systemic, and local factors and each stroke phenotype were then evaluated.

Results
The stroke phenotypes varied among 231 patients (admission INR median 1.06, interquartile range (IQR) 1.00-1.14). Specifically, (1) the DWI lesion volumes ranged from 0.04-338.62 ml (median 11.86 ml; IQR, 3.07-44.20 ml) and (2) 46 patients had a territorial infarct pattern, 118 had a lobar/deep pattern and 67 had a small scattered pattern. Multivariate testing revealed that the CHADS2 and CHA2DS2-VASc score were not related to either stroke phenotype. Additionally, the prior use of antiplatelet agents was not related to the stroke phenotypes. Congestive heart failure and diastolic dysfunction were not associated with stroke phenotypes.

Conclusions
The results of this study indicated that the determinants of stroke phenotypes were different from the predictors (i.e., CHADS2 and CHA2DS2-VASc score) of stroke in patients with AF.
A successfully thrombolysed acute inferior myocardial infarction due to type A aortic dissection with lethal consequences: the importance of early cardiac echocardiography
Authors: Tsigkas Grigorios , Kasimis Georgios , Theodoropoulos Konstantinos , Chouchoulis Konstantinos , Baikoussis Nikolaos G , Apostolakis Efstratios , Bousoula Eleni , Moulias Athanasios , Alexopoulos Dimitrios 
Published: August 2011

Abstract
Thrombolysis, a standard therapy for ST elevation myocardial infarction (STEMI) in non-PCI-capable hospitals, may be catastrophic for patients with aortic dissection leading to further expansion, rupture and uncontrolled bleeding. Stanford type A aortic dissection, rarely may mimic myocardial infarction. We report a case of a patient with an inferior STEMI thrombolysed with tenecteplase and followed by clinical and electrocardiographic evidence of successful reperfusion, which was found later to be a lethal acute aortic dissection. Prognostic implications of early diagnosis applying transthoracic echocardiography (TTE) are described.
Unusual exanthema combined with cerebral vasculitis in pneumococcal meningitis: a case report
Authors: Tavladaki Theonimfi , Spanaki Anna-Maria , Ilia Stavroula , Geromarkaki Elisabeth , Raissaki Maria , Briassoulis George 
Published: August 2011

Abstract

Introduction
Bacterial meningitis is a complex, rapidly progressive disease in which neurological injury is caused in part by the causative organism and in part by the host's own inflammatory responses.

Case presentation
We present the case of a two-year-old Greek girl with pneumococcal meningitis and an atypical curvilinear-like skin eruption, chronologically associated with cerebral vasculitis. A diffusion-weighted MRI scan showed lesions with restricted diffusion, reflecting local areas of immunologically mediated necrotizing vasculitis.

Conclusions
Atypical presentations of bacterial meningitis may occur, and they can be accompanied by serious unexpected complications.
Recurrent takotsubo cardiomyopathy in the setting of transient neurological symptoms: a case report
Authors: Sardar Muhammad Rizwan , Kuntz Catherine , Mazurek Jeremy A , Akhtar Naveed Hassan , Saeed Wajeeha , Shapiro Timothy 
Published: August 2011

Abstract

Introduction
First described in Japan, takotsubo cardiomyopathy is increasingly becoming recognized worldwide as a cause of sudden and reversible diminished left ventricular function characterized by left apical ballooning and hyperkinesis of the basal segments, often with symptoms mimicking a myocardial infarction. Associated with physical or emotional stress, its exact pathogenesis has not been established, though evidence supports a neurohumoral etiology. Additionally, recurrence of this condition is rare. In this report, we present a rare case of recurrent takotsubo cardiomyopathy in a post-menopausal woman who presented with transient neurological complaints on both occasions.

Case presentation
We present a rare case of a 76-year-old Caucasian woman with no history of congestive heart failure who presented to our emergency department twice with transient neurological complaints. On the first occasion, she was found to have transient aphasia which resolved within 24 hours, yet during that period she also developed symptoms of congestive heart failure and was noted to have a new, significantly depressed ejection fraction with apical akinesis and possible apical thrombus. One month after her presentation a repeat echocardiogram revealed complete resolution of all wall motion abnormalities and a return to baseline status. Seven months later she presented with ataxia, was diagnosed with vertebrobasilar insufficiency, and again developed symptoms and echocardiography findings similar to those of her first presentation. Once again, at her one-month follow-up examination, all wall motion abnormalities had completely resolved and her ejection fraction had returned to normal.

Conclusion
Though the exact etiology of takotsubo cardiomyopathy is unclear, a neurohumoral mechanism has been proposed. Recurrence of this disorder is rare, though it has been reported in patients with structural brain abnormalities. This report is the first to describe recurrent takotsubo cardiomyopathy in a patient with transient neurological symptoms. In our patient, as expected in patients with this condition, complete resolution of all left ventricular abnormalities occurred within a short period of time. It is important for clinicians to be aware of this increasingly recognized syndrome, including its association with recurrence, especially in the clinical setting of neurologic dysfunction.
Cold-impaired cardiac performance in rats is only partially overcome by cold acclimation
Authors: Hauton David , May Shaun , Sabharwal Rasna , Deveci Durmus , Egginton Stuart 
Published: August 2011

SUMMARY
The consequences of acute hypothermia include impaired cardiovascular performance, ultimately leading to circulatory collapse. We examined the extent to which this results from intrinsic limitations to cardiac performance or physiological dysregulation/autonomic imbalance, and whether chronic cold exposure could ameliorate the impaired function. Wistar rats were held at a 12 h:12 h light:dark (L:D) photoperiod and room temperature (21°C; euthermic controls), or exposed to a simulated onset of winter in an environmental chamber by progressive acclimation to 1 h:23 h L:D and 4°C over 4 weeks. In vivo, acute cold exposure (core temperature, Tb=25°C) resulted in hypotension (approximately –20%) due to low cardiac output (approximately –30%) accompanying a bradycardia (approximately –50%). Cold acclimation (CA) induced only partial compensation for this challenge, including increased coronary flow at Tb=37°C (but not at Tb=25°C), maintenance of ventricular capillarity and altered sympathovagal balance (increased low:high frequency in power spectral analysis, PSA), suggesting physiological responses alone were insufficient to maintain cardiovascular performance. However, PSA showed maintenance of cardiorespiratory coupling on acute cold exposure in both groups. Ex vivo cardiac performance revealed no change in intrinsic heart rate, but a mechanical impairment of cardiac function at low temperatures following CA. While CA involved an increased capacity for β-oxidation, there was a paradoxical reduction in developed pressure as a result of adrenergic down-regulation. These data suggest that integrated plasticity is the key to cardiovascular accommodation of chronic exposure to a cold environment, but with the potential for improvement by intervention, for example with agents such as non-catecholamine inotropes.
Movement and function of the pectoral fins of the larval zebrafish (Danio rerio) during slow swimming
Authors: Green Matthew H. , Ho Robert K. , Hale Melina E. 
Published: August 2011

SUMMARYPectoral fins are known to play important roles in swimming for many adult fish; however, their functions in fish larvae are unclear. We examined routine pectoral fin movement during rhythmic forward swimming and used genetic ablation to test hypotheses of fin function in larval zebrafish. Fins were active throughout bouts of slow swimming. Initiation was characterized by asymmetric fin abduction that transitioned to alternating rhythmic movement with first fin adduction. During subsequent swimming, fin beat amplitude decreased while tail beat amplitude increased over swimming speeds ranging from 1.47 to 4.56 body lengths per second. There was no change in fin or tail beat frequency with speed (means ± s.d.: 28.2±3.5 and 29.6±1.9 Hz, respectively). To examine potential roles of the pectoral fins in swimming, we compared the kinematics of finless larvae generated with a morpholino knockdown of the gene fgf24 to those of normal fish. Pectoral fins were not required for initiation nor did they significantly impact forward rhythmic swimming. We investigated an alternative hypothesis that the fins function in respiration. Dye visualization demonstrated that pectoral fin beats bring distant fluid toward the body and move it caudally behind the fins, disrupting the boundary layer along the body's surface, a major site of oxygen absorption in larvae. Larval zebrafish also demonstrated more fin beating in low oxygen conditions. Our data reject the hypothesis that the pectoral fins of larval zebrafish have a locomotor function during slow, forward locomotion, but are consistent with the hypothesis that the fins have a respiratory function.
Magnetic orientation of migratory robins, Erithacus rubecula, under long-wavelength light
Authors: Wiltschko Roswitha , Denzau Susanne , Gehring Dennis , Thalau Peter , Wiltschko Wolfgang 
Published: August 2011

SUMMARY
The avian magnetic compass is an inclination compass that appears to be based on radical pair processes. It requires light from the short-wavelength range of the spectrum up to 565 nm green light; under longer wavelengths, birds are disoriented. When pre-exposed to longer wavelengths for 1 h, however, they show oriented behavior. This orientation is analyzed under 582 nm yellow light and 645 nm red light in the present study: while the birds in spring prefer northerly directions, they do not show southerly tendencies in autumn. Inversion of the vertical component does not have an effect whereas reversal of the horizontal component leads to a corresponding shift, indicating that a polar response to the magnetic field is involved. Oscillating magnetic fields in the MHz range do not affect the behavior but anesthesia of the upper beak causes disorientation. This indicates that the magnetic information is no longer provided by the radical pair mechanism in the eye but by the magnetite-based receptors in the skin of the beak. Exposure to long-wavelength light thus does not expand the spectral range in which the magnetic compass operates but instead causes a different mechanism to take over and control orientation.
Moufang loops that are almost groups
Authors: Chee Wing Loon , Rajah Andrew 
Published: August 2011

AbstractIt is known that Moufang loops are closely related to groups as they have many properties in common. For instance, they both have an inverse for each element and satisfy Lagrange's theorem. In this paper, we study the properties of a class of Moufang loops which are not groups, but all their proper subloops and proper quotient loops are groups.