bluuebunny/crossref_metadata_2025_split huggingface dataset:
Association of Noninvasively Measured Left Ventricular Mechanics With In Vitro Muscle Contractile Performance: A Prospective Study in Hypertrophic Cardiomyopathy Patients
Authors: Dhillon Ashwat , Sweet Wendy , Popovic Zoran B. , Smedira Nicholas G. , Thamilarasan Maran , Lytle Bruce W. , Tan Carmela , Starling Randall C. , Lever Harry M. , Moravec Christine S. , Desai Milind Y. 
Published: November 2014

Background

Hypertrophic cardiomyopathy (
HCM
) is a primary myopathic process in which regional left ventricular dysfunction may exist without overt global
left ventricular
dysfunction. In obstructive
HCM
patients who underwent surgical myectomy (
SM
), we sought to determine if there is a significant association between echocardiographic longitudinal strain, histopathology, and in vitro myocardial performance (resting tension and developed tension) of the surgical specimen.

Methods and Results

HCM
patients (n=122, 54±14 years, 54% men) undergoing
SM
were prospectively recruited. Longitudinal systolic strain and diastolic strain rates were measured at that basal septum (partially removed at
SM
) by using velocity vector imaging on preoperative echocardiography. Semiquantitative histopathologic grading of myocyte disarray and fibrosis and in vitro measurements of
resting tension
and
developed tension
were made in septal tissue obtained at
SM
. Mean basal septal systolic strain and diastolic strain rate were −8.3±5% and 0.62±0.4/s, while mild or greater degree of myocyte disarray and interstitial fibrosis were present in 85% and 87%, respectively. Mean resting tension and developed tension were 2.8±1 and 1.4±0.8 g/mm
2
. On regression analysis, basal septal systolic strain, diastolic strain rate, disarray, and fibrosis were associated with developed tension (β=0.19, 0.20, −0.33, and −0.40, respectively, all
P
<0.01) and
resting tension
(β=0.21, 0.22, −0.25, and −0.28, respectively, all
P
<0.01).

Conclusion

In obstructive
HCM
patients who underwent
SM
,
left ventricular
mechanics (echocardiographic longitudinal systolic strain and diastolic strain rates), assessed at the basal septum (myocardium removed during myectomy) and histopathologic findings characteristic for
HCM
(disarray and fibrosis) were significantly associated with in vitro myocardial resting and developed contractile performance.
Myoblast-Mediated Gene Therapy Improves Functional Collateralization in Chronic Cerebral Hypoperfusion
Authors: Hecht Nils , Marushima Aiki , Nieminen Melina , Kremenetskaia Irina , von Degenfeld Georges , Woitzik Johannes , Vajkoczy Peter 
Published: November 2014

Background and Purpose—
Direct extracranial–intracranial bypass surgery for treatment of cerebral hemodynamic compromise remains hindered by complications but alternative simple and safe indirect revascularization procedures, such as an encephalomyosynangiosis (EMS), lack hemodynamic efficiency. Here, the myoblast-mediated transfer of angiogenic genes presents an approach for induction of therapeutic collateralization. In this study, we tested the effect of myoblast-mediated delivery of vascular endothelial growth factor-A (VEGF) to the muscle/brain interface of an EMS in a model of chronic cerebral hypoperfusion.

Methods—

Permanent unilateral internal carotid artery-occlusion was performed in adult C57/BL6 mice with or without (no EMS) surgical grafting of an EMS followed by implantation of monoclonal mouse myoblasts expressing either VEGF
164
or an empty vector (EV). Cerebral hemodynamic impairment, transpial collateralization, angiogenesis, mural cell investment, microvascular permeability, and cortical infarction after ipsilateral stroke were assessed by real-time laser speckle blood flow imaging, 2- and 3-dimensional immunofluorescence and MRI.

Results—

VEGF-expressing myoblasts improved hemodynamic rescue by day 14 (no EMS 37±21%, EV 42±9%, VEGF 48±12%;
P
<0.05 for VEGF versus no EMS and versus EV), together with the EMS take rate (VEGF 60%, EV 18.2%;
P
<0.05) and angiogenesis of mature cortical microvessels below the EMS (
P
<0.05 for VEGF versus EV). Importantly, functional and morphological results were paralleled by a 25% reduction of cortical infarction after experimental stroke on the side of the EMS.

Conclusions—
Myoblast-mediated VEGF supplementation at the target site of an EMS could help overcome the clinical dilemma of poor surgical revascularization results and provide protection from ischemic stroke.
Sensitivity of Diffusion- and Perfusion-Weighted Imaging for Diagnosing Acute Ischemic Stroke Is 97.5%
Authors: Simonsen Claus Z. , Madsen Mette H. , Schmitz Marie L. , Mikkelsen Irene K. , Fisher Marc , Andersen Grethe 
Published: November 2014

Background and Purpose—
MRI using diffusion-weighted imaging (DWI) is the most sensitive diagnostic imaging modality for early detection of ischemia, but how accurate is it and how much does perfusion-weighted imaging (PWI) add to the sensitivity have to be known.

Methods—
In this single-center study, we collected epidemiological, imaging, and outcome data on all patients with stroke undergoing MRI-based treatment with intravenous tissue-type plasminogen activator at our center from 2004 to 2010. The DWI negative patients were identified, and we calculated the sensitivity and specificity of DWI and additional PWI for diagnosing acute ischemic stroke. We compared DWI positive and negative patients to identify characteristics associated with DWI negativity.

Results—
Five hundred sixty-nine consecutive patients were treated with intravenous tissue-type plasminogen activator on the basis of an acute MRI. A DWI lesion was evident in 518 patients. Forty-seven patients were DWI negative; however, a relevant PWI lesion was found in 33 of these patients. Four stroke mimics were treated with intravenous tissue-type plasminogen activator and 1 of these patients had a DWI lesion. Thus, 8% of all patients with stroke were DWI negative. The combination of DWI and PWI resulted in a sensitivity of 97.5% for the ischemic stroke diagnosis. DWI negativity was associated with less severe strokes, location in the posterior circulation, a longer time from onset to scan, and an improved 90-day outcome. The cause of small-vessel disease was more likely to be DWI negative.

Conclusions—
The combination of DWI and PWI before intravenous tissue-type plasminogen activator confirms the diagnosis in 97.5% of all ischemic strokes.
Arteriopathy Diagnosis in Childhood Arterial Ischemic Stroke
Authors: Wintermark Max , Hills Nancy K. , deVeber Gabrielle A. , Barkovich A. James , Elkind Mitchell S.V. , Sear Katherine , Zhu Guangming , Leiva-Salinas Carlos , Hou Qinghua , Dowling Michael M. , Bernard Timothy J. , Friedman Neil R. , Ichord Rebecca N. , Fullerton Heather J. , Benedict S.L. , Fox C.K. , Lo W.D. , Tan M.A. , Mackay M.T. , Kirton A. , Hernandez Chavez M.I. , Humphreys P. , Jordan L.C. , Sultan S.M. , Rivkin M.J. , Rafay M.F. , Titomanlio L. , Kovacevic G.S. , Yager J.Y. , Amlie-Lefond C. , Dlamini N. , Condie J. , Yeh A. , Kneen R. , Bjornson B.H. , Pergami P. , Zou L.P. , Elbers J. , Abdalla A. , Chan A.K. , Farooq O. , Lim M.J. , Carpenter J.L. , Pavlakis S. , Wong V.C. , Forsyth R. 
Published: November 2014

Background and Purpose—
Although arteriopathies are the most common cause of childhood arterial ischemic stroke, and the strongest predictor of recurrent stroke, they are difficult to diagnose. We studied the role of clinical data and follow-up imaging in diagnosing cerebral and cervical arteriopathy in children with arterial ischemic stroke.

Methods—
Vascular effects of infection in pediatric stroke, an international prospective study, enrolled 355 cases of arterial ischemic stroke (age, 29 days to 18 years) at 39 centers. A neuroradiologist and stroke neurologist independently reviewed vascular imaging of the brain (mandatory for inclusion) and neck to establish a diagnosis of arteriopathy (definite, possible, or absent) in 3 steps: (1) baseline imaging alone; (2) plus clinical data; (3) plus follow-up imaging. A 4-person committee, including a second neuroradiologist and stroke neurologist, adjudicated disagreements. Using the final diagnosis as the gold standard, we calculated the sensitivity and specificity of each step.

Results—
Cases were aged median 7.6 years (interquartile range, 2.8–14 years); 56% boys. The majority (52%) was previously healthy; 41% had follow-up vascular imaging. Only 56 (16%) required adjudication. The gold standard diagnosis was definite arteriopathy in 127 (36%), possible in 34 (9.6%), and absent in 194 (55%). Sensitivity was 79% at step 1, 90% at step 2, and 94% at step 3; specificity was high throughout (99%, 100%, and 100%), as was agreement between reviewers (κ=0.77, 0.81, and 0.78).

Conclusions—
Clinical data and follow-up imaging help, yet uncertainty in the diagnosis of childhood arteriopathy remains. This presents a challenge to better understanding the mechanisms underlying these arteriopathies and designing strategies for prevention of childhood arterial ischemic stroke.
Sensitivity to Object Impossibility in the Human Visual Cortex: Evidence from Functional Connectivity
Authors: Freud Erez , Rosenthal Gideon , Ganel Tzvi , Avidan Galia 
Published: November 2014

Abstract
Processing spatial configuration is a fundamental requirement for object recognition. Using fMRI, the neural basis underlying this ability was examined while human participants viewed possible and visually similar, but spatially impossible, objects presented for either long or short exposure duration. Response profiles in object-selective cortical regions exhibited sensitivity to object possibility, but only for the long exposure duration. Contrary, functional connectivity, indexed by the pairwise correlations between activation profiles across ROIs, revealed sensitivity to possibility, evident in enhanced correlations for impossible compared with possible objects. Such sensitivity was found even following a brief exposure duration, which allowed only minimal awareness of possibility. Importantly, this sensitivity was correlated with participants' general spatial ability as assessed by an independent neuropsychological test. These results suggest that the visual system is highly susceptible to objects' 3-D structural information even with minimal perceptual awareness. Such sensitivity is captured at the level of functional connectivity between object-selective regions, rather than the absolute level of within-region activity, implicating the role of interregional synchronization in the representation of objects' 3-D structure.
When Imagining Yourself in Pain, Visual Perspective Matters: The Neural and Behavioral Correlates of Simulated Sensory Experiences
Authors: Christian Brittany M. , Parkinson Carolyn , Macrae C. Neil , Miles Lynden K. , Wheatley Thalia 
Published: November 2014

Abstract
Via mental simulation, imagined events faithfully reproduce the neural and behavioral activities that accompany their actual occurrence. However, little is known about how fundamental characteristics of mental imagery—notably perspectives of self—shape neurocognitive processes. To address this issue, we used fMRI to explore the impact that vantage point exerts on the neural and behavioral correlates of imaginary sensory experiences (i.e., pain). Participants imagined painful scenarios from three distinct visual perspectives: first-person self (1PS), third-person self (3PS), and third-person other (3PO). Corroborating increased ratings of pain and embodiment, 1PS (cf. 3PS) simulations elicited greater activity in the right anterior insula, a brain area that supports interoceptive and emotional awareness. Additionally, 1PS simulations evoked greater activity in brain areas associated with visual imagery and the sense of body ownership. Interestingly, no differences were observed between 3PS and 3PO imagery. Taken together, these findings reveal the neural and behavioral correlates of visual perspective during mental simulation.
Variable Left-hemisphere Language and Orthographic Lateralization Reduces Right-hemisphere Face Lateralization
Authors: Dundas Eva M. , Plaut David C. , Behrmann Marlene 
Published: November 2014

Abstract
It is commonly believed that, in right-handed individuals, words and faces are processed by distinct neural systems: one in the left hemisphere (LH) for words and the other in the right hemisphere (RH) for faces. Emerging evidence suggests, however, that hemispheric selectivity for words and for faces may not be independent of each other. One recent account suggests that words become lateralized to the LH to interact more effectively with language regions, and subsequently, as a result of competition with words for representational space, faces become lateralized to the RH. On this interactive account, left-handed individuals, who as a group show greater variability with respect to hemispheric language dominance, might be expected to show greater variability in their degree of RH lateralization of faces as well. The current study uses behavioral measures and ERPs to compare the hemispheric specialization for both words and faces in right- and left-handed adult individuals. Although both right- and left-handed groups demonstrated LH over RH superiority in discrimination accuracy for words, only the right-handed group demonstrated RH over LH advantage in discrimination accuracy for faces. Consistent with this, increased right-handedness was related to an increase in RH superiority for face processing, as measured by the strength of the N170 ERP component. Interestingly, the degree of RH behavioral superiority for face processing and the amplitude of the RH N170 for faces could be predicted by the magnitude of the N170 ERP response to words in the LH. These results are discussed in terms of a theoretical account in which the typical RH face lateralization fails to emerge in individuals with atypical language lateralization because of weakened competition from the LH representation of words.
The Impact of Musicianship on the Cortical Mechanisms Related to Separating Speech from Background Noise
Authors: Zendel Benjamin Rich , Tremblay Charles-David , Belleville Sylvie , Peretz Isabelle 
Published: November 2014

Abstract
Musicians have enhanced auditory processing abilities. In some studies, these abilities are paralleled by an improved understanding of speech in noisy environments, partially due to more robust encoding of speech signals in noise at the level of the brainstem. Little is known about the impact of musicianship on attention-dependent cortical activity related to lexical access during a speech-in-noise task. To address this issue, we presented musicians and nonmusicians with single words mixed with three levels of background noise, across two conditions, while monitoring electrical brain activity. In the active condition, listeners repeated the words aloud, and in the passive condition, they ignored the words and watched a silent film. When background noise was most intense, musicians repeated more words correctly compared with nonmusicians. Auditory evoked responses were attenuated and delayed with the addition of background noise. In musicians, P1 amplitude was marginally enhanced during active listening and was related to task performance in the most difficult listening condition. By comparing ERPs from the active and passive conditions, we isolated an N400 related to lexical access. The amplitude of the N400 was not influenced by the level of background noise in musicians, whereas N400 amplitude increased with the level of background noise in nonmusicians. In nonmusicians, the increase in N400 amplitude was related to a reduction in task performance. In musicians only, there was a rightward shift of the sources contributing to the N400 as the level of background noise increased. This pattern of results supports the hypothesis that encoding of speech in noise is more robust in musicians and suggests that this facilitates lexical access. Moreover, the shift in sources suggests that musicians, to a greater extent than nonmusicians, may increasingly rely on acoustic cues to understand speech in noise.
Value Is in the Eye of the Beholder: Early Visual Cortex Codes Monetary Value of Objects during a Diverted Attention Task
Authors: Persichetti Andrew S. , Aguirre Geoffrey K. , Thompson-Schill Sharon L. 
Published: November 2014

Abstract
A central concern in the study of learning and decision-making is the identification of neural signals associated with the values of choice alternatives. An important factor in understanding the neural correlates of value is the representation of the object itself, separate from the act of choosing. Is it the case that the representation of an object within visual areas will change if it is associated with a particular value? We used fMRI adaptation to measure the neural similarity of a set of novel objects before and after participants learned to associate monetary values with the objects. We used a range of both positive and negative values to allow us to distinguish effects of behavioral salience (i.e., large vs. small values) from effects of valence (i.e., positive vs. negative values). During the scanning session, participants made a perceptual judgment unrelated to value. Crucially, the similarity of the visual features of any pair of objects did not predict the similarity of their value, so we could distinguish adaptation effects due to each dimension of similarity. Within early visual areas, we found that value similarity modulated the neural response to the objects after training. These results show that an abstract dimension, in this case, monetary value, modulates neural response to an object in visual areas of the brain even when attention is diverted.
The Atacama Surface Solar Maximum
Authors: Rondanelli Roberto , Molina Alejandra , Falvey Mark 
Published: November 2014

Abstract
Solar radiation reaching Earth’s surface is one of the major drivers of climate dynamics. By setting the surface energy balance, downwelling solar radiation indirectly heats the atmosphere and controls the hydrological cycle. Besides its critical importance as a physical mechanism for driving climate and weather, solar radiation has attracted interest as a potentially major source of energy for human activities.
For a given latitude, solar radiation at Earth’s surface depends mostly on the composition along the atmospheric path. Since the early twentieth century, major astronomical observatories have led the search for the best places for observation from Earth, which presents a similar problem to the one of finding the maximum of solar radiation at the surface. In particular, Mount Montezuma in the Atacama Desert, Chile, was identified by the pioneers of solar observation as an ideal place to conduct the search for variations of the solar constant estimated from Earth’s surface.
By using available global datasets, a semiempirical model for the surface solar radiation over northern Chile, and a network of surface stations, we confirm Atacama as the place where the highest mean surface solar radiation is found. The most likely location of the maximum downwelling solar radiation over the surface of the planet is on the pre-Andean Domeyko Cordillera (3,500–5,000 m above mean sea level, between 24° and 25°S, along 69°W) with a value of about 310 ± 15 W m–2. We discuss the main regional and local features of this region that conspire to produce the solar maximum.
On the Seasonal and Synoptic Time-Scale Variability of the North Atlantic Trade Wind Region and Its Low-Level Clouds
Authors: Brueck Matthias , Nuijens Louise , Stevens Bjorn 
Published: November 2014

Abstract
The seasonality in large-scale meteorology and low-level cloud amount (CClow) is explored for a 5° × 5° area in the North Atlantic trades, using 12 years of ERA-Interim and MODIS data, supported by 2 years of Barbados Cloud Observatory (BCO) measurements. From boreal winter to summer, large-scale subsiding motion changes to rising motion, along with an increase in sea surface temperature, a clockwise turning and weakening of low-level winds, and reduced cold-air advection, lower-tropospheric stability (LTS), and surface fluxes. However, CClow is relatively invariant around 30%, except for a minimum of 20% in fall. This minimum is only pronounced when MODIS scenes with large high-level cloud amount are excluded, and a winter maximum in CClow is more pronounced at the BCO. On monthly time scales, wind speed has the best correlation with CClow. Existing large-eddy simulations suggest that the wind speed–CClow correlation may be explained by a direct deepening response of the trade wind layer to stronger winds. Large correlations of wind direction and advection with CClow also suggest that large-scale flow patterns matter. Smaller correlations with CClow are observed for LTS and surface evaporation, as well as negligible correlations for relative humidity (RH) and vertical velocity. However, these correlations considerably increase when only summer is considered. On synoptic time scales, all correlations drop substantially, whereby wind speed, RH, and surface sensible heat flux remain the leading parameters. The lack of a single strong predictor emphasizes that the combined effect of parameters is necessary to explain variations in CClow in the trades.
Different Types of Cold Vortex Circulations over Northeast China and Their Weather Impacts
Authors: Xie Zuowei , Bueh Cholaw 
Published: November 2014

Abstract
A deep and cold vortex circulation often occurs over northeast China. Known as the northeast China cold vortex (NCCV), the phenomenon is most active from May to mid-June and can lead to extremely cold local temperatures. This study used rotated principle component analysis to categorize NCCV events into four types, which were characterized by ridges (or blocks) over the following regions: Lake Baikal (BKL), the Yenisei River valley (YNS), the Ural Mountains (UR), and the Yakutsk–Okhotsk region (YO).
On the intraseasonal time scale, it was found that BKL- and YNS-type NCCVs formed when the wave train height anomalies originating from the North Atlantic and Europe propagated to East Asia. In contrast, YO- and UR-type NCCVs formed in conjunction with the development of a meridional dipole pattern over northeast Asia. The existence of a blocking-type circulation over the Yakutsk–Okhotsk region favored maintenance of the NCCV circulation for the long-lived (more than 5 days) NCCV events of the four types. The typical circulation over northeast Asia for the long-lived NCCV event was closely associated with wave breaking, whereas the short-lived (3–5 days) event showed only wave propagation.
The YNS-type NCCV caused cold surface air temperatures (SAT) not only over northeast China, but also over central and south China, whereas the other three types led only to regional cold SAT anomalies over northeast China. All four types of NCCVs caused a precipitation increase over northeast China, and this effect was broader for the UR- and YO-type NCCVs than that for BKL- and YNS-type NCCVs.