bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of LMI1195, a Novel
18
F-Labeled Cardiac Neuronal PET Imaging Agent, in Cells and Animal Models
Authors: Yu Ming , Bozek Jody , Lamoy Melanie , Guaraldi Mary , Silva Paula , Kagan Mikhail , Yalamanchili Padmaja , Onthank David , Mistry Mahesh , Lazewatsky Joel , Broekema Matthias , Radeke Heike , Purohit Ajay , Cdebaca Michael , Azure Michael , Cesati Richard , Casebier David , Robinson Simon P.
Published: May 2011

Background—

Heart failure has been associated with impaired cardiac sympathetic neuronal function. Cardiac imaging with radiolabeled agents that are substrates for the neuronal norepinephrine transporter (NET) has demonstrated the potential to identify individuals at risk of cardiac events.
N
-[3-Bromo-4-(3-[
18
F]fluoro-propoxy)-benzyl]-guanidine (LMI1195) is a newly developed
18
F-labeled NET substrate designed to allow cardiac neuronal imaging with the high sensitivity, resolution, and quantification afforded by positron emission tomography (PET).

Methods and Results—

LMI1195 was evaluated in comparison with norepinephrine (NE) in vitro and
123
I-meta-iodobenzylguanidine (MIBG) in vivo. The affinity (K
i
) of LMI1195 for NET was 5.16±2.83 μmol/L, similar to that of NE (3.36±2.77 μmol/L) in a cell membrane–binding assay. Similarly, LMI1195 uptake kinetics examined in a human neuroblastoma cell line had K
m
and V
max
values of 1.44±0.76 μmol/L and 6.05±3.09 pmol/million cells per minute, comparable to NE (2.01±0.85 μmol/L and 6.23±1.52 pmol/million cells per minute). In rats, LMI1195 heart uptake at 15 and 60 minutes after intravenous administration was 2.36±0.38% and 2.16±0.38% injected dose per gram of tissue (%ID/g), similar to
123
I-MIBG (2.14±0.30 and 2.19±0.27%ID/g). However, the heart to liver and lung uptake ratios were significantly higher for LMI1195 than for
123
I-MIBG. In rabbits, desipramine (1 mg/kg), a selective NET inhibitor, blocked LMI1195 heart uptake by 82%, which was more effective than
123
I-MIBG (53%), at 1 hour after dosing. Sympathetic denervation with 6-hydroxydopamine, a neurotoxin, resulted in a marked (79%) decrease in LMI1195 heart uptake. Cardiac PET imaging with LMI1195 in rats, rabbits, and nonhuman primates revealed clear myocardium with low radioactivity levels in the blood, lung, and liver. Imaging in rabbits pretreated with desipramine showed reduced heart radioactivity levels in a dose-dependent manner. Additionally, imaging in sympathetically denervated rabbits resulted in low cardiac image intensity with LMI1195 but normal perfusion images with flurpiridaz F 18, a PET myocardial perfusion imaging agent. In nonhuman primates pretreated with desipramine (0.5 mg/kg), imaging with LMI1195 showed a 66% decrease in myocardial uptake. In a rat model of heart failure, the LMI1195 cardiac uptake decreased as heart failure progressed.

Conclusions—

LMI1195 is a novel
18
F imaging agent retained in the heart through the NET and allowing evaluation of the cardiac sympathetic neuronal function by PET imaging.
Strategic Approaches to Unraveling Genetic Causes of Cardiovascular Diseases
Authors: Marian A.J. , Belmont John
Published: May 2011

DNA sequence variants are major components of the “causal field” for virtually all medical phenotypes, whether single gene familial disorders or complex traits without a clear familial aggregation. The causal variants in single gene disorders are necessary and sufficient to impart large effects. In contrast, complex traits are attributable to a much more complicated network of contributory components that in aggregate increase the probability of disease. The conventional approach to identification of the causal variants for single gene disorders is genetic linkage. However, it does not offer sufficient resolution to map the causal genes in small families or sporadic cases. The approach to genetic studies of complex traits entails candidate gene or genome-wide association studies. Genome-wide association studies provide an unbiased survey of the effects of common genetic variants (common disease–common variant hypothesis). Genome-wide association studies have led to identification of a large number of alleles for various cardiovascular diseases. However, common alleles account for a relatively small fraction of the total heritability of the traits. Accordingly, the focus has shifted toward identification of rare variants that might impart larger effect sizes (rare variant–common disease hypothesis). This shift is made feasible by recent advances in massively parallel DNA sequencing platforms, which afford the opportunity to identify virtually all common as well as rare alleles in individuals. In this review, we discuss various strategies that are used to delineate the genetic contribution to medically important cardiovascular phenotypes, emphasizing the utility of the new deep sequencing approaches.
Ethnic Differences in Out-of-Hospital Fatal Pulmonary Embolism
Authors: Tang Yingying , Sampson Barbara , Pack Stephanie , Shah Krunal , Yon Um Sung , Wang Dawei , Wang Tao , Prinz Mechthild
Published: May 2011

Background—

In-hospital pulmonary embolism (PE) has been extensively studied in large populations; however, out-of-hospital fatal PE studies are rare. Here, we systematically evaluated a large number of decedents who suffered fatal PE outside of hospitals and were subsequently investigated by the New York City Office of Chief Medical Examiner.

Methods and Results—

A total of 578 consecutive out-of-hospital fatal PE cases were analyzed. All underwent autopsy, toxicology, microbiology, and genetic testing. Incidence rates and baseline characteristics were analyzed. Race-adjusted incidence rates of out-of-hospital fatal PE (per 100 000 people per year) were as follows: blacks, 3.73 (95% confidence interval, 3.31 to 4.11); whites, 1.15 (95% confidence interval, 0.96 to 1.33); and Hispanics, 0.93 (95% confidence interval, 0.72 to 1.10). Overall, obesity (body mass index ≥30 kg/m
2
) was 2.5- to 3-fold higher in fatal PE cases than in the New York City population as a whole. Carrier frequencies for prothrombin G20210A in fatal PE were 2- to 10-fold higher than reported frequencies in ethnically matched controls. Cumulative distribution curves showed that compared with whites, blacks and Hispanics died at significantly younger ages (
P
<0.001). Univariate and multiple linear regression analyses showed that in addition to nonwhite ethnicity, heterozygous carriers for factor V Leiden (
P
=0.001) and obesity (
P
=0.002) are significantly associated with younger age at death.

Conclusion—

There are unique epidemiological differences in out-of-hospital fatal PE between ethnic groups in New York City.
Endothelium-Derived Hyperpolarizing Factor Determines Resting and Stimulated Forearm Vasodilator Tone in Health and in Disease
Authors: Ozkor Muhiddin A. , Murrow Jonathan R. , Rahman Ayaz M. , Kavtaradze Nino , Lin Ji , Manatunga Amita , Quyyumi Arshed A.
Published: May 2011

Background—

We assessed the contribution of endothelium-derived hyperpolarizing factors to resting and agonist-stimulated vasodilator tone in health and disease. Tetraethylammonium chloride (TEA) was used to inhibit K
+
Ca
channel activation and fluconazole was used to inhibit cytochrome P450 2C9–mediated epoxyeicosatrienoic acid synthesis. We hypothesized that endothelium-derived hyperpolarizing factors contribute to resting vascular tone by K
+
Ca
channel activation and epoxyeicosatrienoic acid release and that endothelium-derived hyperpolarizing factors compensate for reduced nitric oxide bioavailability at rest and with endothelium-dependent vasodilators.

Methods and Results—

In 103 healthy subjects and 71 nonhypertensive subjects with multiple risk factors, we measured resting forearm blood flow (FBF) using venous occlusion plethysmography before and after intra-arterial infusions of
N
G
-monomethyl-
l
-arginine (L-NMMA), TEA, fluconazole, and their combination. The effects of these antagonists on resting FBF and on bradykinin- and acetylcholine-mediated vasodilation were studied. Resting FBF decreased with TEA and L-NMMA in all subjects (
P
<0.001); however, the vasoconstrictor response to L-NMMA was greater (
P
=0.04) and to TEA was lower (
P
=0.04) in healthy subjects compared with those with risk factors. Fluconazole decreased resting FBF in all subjects, and the addition of TEA further reduced FBF after fluconazole, suggesting that cytochrome P450 metabolites and other hyperpolarizing factor(s) activate K
+
Ca
channels. Both L-NMMA and TEA attenuated bradykinin-mediated vasodilation in healthy and hypercholesterolemic subjects (
P
<0.001). In contrast, acetylcholine-mediated vasodilation remained unchanged with TEA in healthy subjects but was significantly attenuated in hypercholesterolemia (
P
<0.04).

Conclusions—

First, by activating TEA-inhibitable K
+
Ca
channels, endothelium-derived hyperpolarizing factors, together with nitric oxide, contribute to resting microvascular dilator tone. The contribution of K
+
Ca
channel activation compared with nitric oxide is greater in those with multiple risk factors compared with healthy subjects. Second, activation of K
+
Ca
channels is only partly through epoxyeicosatrienoic acid release, indicating the presence of other hyperpolarizing mechanisms. Third, bradykinin, but not acetylcholine, stimulates K
+
Ca
channel–mediated vasodilation in healthy subjects, whereas in hypercholesterolemia, K
+
Ca
channel-mediated vasodilation compensates for the reduced nitric oxide activity. Thus, enhanced endothelium-derived hyperpolarizing factor activity in conditions of nitric oxide deficiency contributes to maintenance of resting and agonist-stimulated vasodilation.

Clinical Trial Registration—

URL:
http://www.clinicaltrials.gov
. Unique identifier: NCT00166166.
Poor Sleep and Cardiovascular Function in Children
Authors: Martikainen Silja , Pesonen Anu-Katriina , Feldt Kimmo , Jones Alexander , Lahti Jari , Pyhälä Riikka , Heinonen Kati , Kajantie Eero , Eriksson Johan , Räikkönen Katri
Published: May 2011

We investigated whether sleep quantity and quality were related to 24-hour ambulatory blood pressure and cardiovascular reactivity in children. We studied term-born, healthy 8.0-year olds (SD: 1.4 years) without sleep-disordered breathing (231 and 265 children provided valid data for analyses of ambulatory blood pressure and cardiovascular reactivity, respectively). Sleep was registered with an actigraph for 6 nights on average (SD: 1.2; range: 3 to 13 nights). Ambulatory blood pressure was measured for 24-hours (41% nonschool days) with an oscillometric device. The children underwent the Trier Social Stress Test for Children, during which blood pressure, electrocardiography, and thoracic impedance were recorded and processed offline to give measures of cardiovascular and autonomic function. Neither quantity nor quality of sleep was related to 24-hour ambulatory blood pressure or cardiovascular reactivity after accounting for major covariates (sex, age, height, body mass index, and parental education). Although lower sympathetic nervous system activation and higher cardiac activation under stress were found in the group of children who slept for short duration when they were compared with the average sleep duration group, these associations were not significant after correction for multiple testing and were not seen in linear regression models of the effects of sleep duration. These findings do not support the mainstream of epidemiological findings, derived from samples more heterogeneous in age, sociodemographic characteristics, and health, suggesting that poor sleep is associated with an unhealthy cardiovascular phenotype.
Act Quickly, Decide Later: Long-latency Visual Processing Underlies Perceptual Decisions but Not Reflexive Behavior
Authors: Jolij Jacob , Scholte H. Steven , van Gaal Simon , Hodgson Timothy L. , Lamme Victor A. F.
Published: May 2011

Humans largely guide their behavior by their visual representation of the world. Recent studies have shown that visual information can trigger behavior within 150 msec, suggesting that visually guided responses to external events, in fact, precede conscious awareness of those events. However, is such a view correct? By using a texture discrimination task, we show that the brain relies on long-latency visual processing in order to guide perceptual decisions. Decreasing stimulus saliency leads to selective changes in long-latency visually evoked potential components reflecting scene segmentation. These latency changes are accompanied by almost equal changes in simple RTs and points of subjective simultaneity. Furthermore, we find a strong correlation between individual RTs and the latencies of scene segmentation related components in the visually evoked potentials, showing that the processes underlying these late brain potentials are critical in triggering a response. However, using the same texture stimuli in an antisaccade task, we found that reflexive, but erroneous, prosaccades, but not antisaccades, can be triggered by earlier visual processes. In other words: The brain can act quickly, but decides late. Differences between our study and earlier findings suggesting that action precedes conscious awareness can be explained by assuming that task demands determine whether a fast and unconscious, or a slower and conscious, representation is used to initiate a visually guided response.
Neural Basis of Linearization in Speech Production
Authors: Ye Zheng , Habets Boukje , Jansma Bernadette M. , Münte Thomas F.
Published: May 2011

An initial stage of speech production is conceptual planning, where a speaker determines which information to convey first (the linearization problem). This fMRI study investigated the linearization process during the production of “before” and “after” sentences. In “after” sentences, a series of events is expressed in the order of event occurrence. In “before” sentences, however, the order of event mention is achieved by reversing the chronological order. We suggested that the linearization process may be supported by a neural network connecting the left middle temporal gyrus (MTG) with the medial superior frontal gyrus, left middle frontal gyrus, and left angular gyrus/inferior parietal gyrus. Within this network, regions were more activated and interregional interactions were strongly enhanced for producing “before” than “after” sentences. The left MTG was also functionally connected with the left orbital inferior frontal gyrus, contributing to the retrieval of necessary world knowledge and linguistic knowledge. Connectivity between these two regions was not different between conditions.
Mine and Me: Exploring the Neural Basis of Object Ownership
Authors: Turk David J. , van Bussel Kim , Waiter Gordon D. , Macrae C. Neil
Published: May 2011

Previous research has shown that encoding information in the context of self-evaluation leads to memory enhancement, supported by activation in ventromedial pFC. Recent evidence suggests that similar self-memory advantages can be obtained under nonevaluative encoding conditions, such as when object ownership is used to evoke self-reference. Using fMRI, the current study explored the neural correlates of object ownership. During scanning, participants sorted everyday objects into self-owned or other-owned categories. Replicating previous research, a significant self-memory advantage for the objects was observed (i.e., self-owned > other-owned). In addition, encoding self-owned items was associated with unique activation in posterior dorsomedial pFC (dMPFC), left insula, and bilateral supramarginal gyri (SMG). Subsequent analysis showed that activation in a subset of these regions (dMPFC and left SMG) correlated with the magnitude of the self-memory advantage. Analysis of the time-to-peak data suggested a temporal model for processing ownership in which initial activation of dMPFC spreads to SMG and insula. These results indicate that a self-memory advantage can be elicited by object ownership and that this effect is underpinned by activity in a neural network that supports attentional, reward, and motor processing.
From an Executive Network to Executive Control: A Computational Model of the n-back Task
Authors: Chatham Christopher H. , Herd Seth A. , Brant Angela M. , Hazy Thomas E. , Miyake Akira , O'Reilly Randy , Friedman Naomi P.
Published: May 2011

A paradigmatic test of executive control, the n-back task, is known to recruit a widely distributed parietal, frontal, and striatal “executive network,” and is thought to require an equally wide array of executive functions. The mapping of functions onto substrates in such a complex task presents a significant challenge to any theoretical framework for executive control. To address this challenge, we developed a biologically constrained model of the n-back task that emergently develops the ability to appropriately gate, bind, and maintain information in working memory in the course of learning to perform the task. Furthermore, the model is sensitive to proactive interference in ways that match findings from neuroimaging and shows a U-shaped performance curve after manipulation of prefrontal dopaminergic mechanisms similar to that observed in studies of genetic polymorphisms and pharmacological manipulations. Our model represents a formal computational link between anatomical, functional neuroimaging, genetic, behavioral, and theoretical levels of analysis in the study of executive control. In addition, the model specifies one way in which the pFC, BG, parietal, and sensory cortices may learn to cooperate and give rise to executive control.
Disrupting the Ventral Premotor Cortex Interferes with the Contribution of Action Observation to Use-dependent Plasticity
Authors: Cantarero Gabriela , Galea Joseph M. , Ajagbe Loni , Salas Rachel , Willis Jeff , Celnik Pablo
Published: May 2011

Action observation (AO), observing another individual perform an action, has been implicated in several higher cognitive processes including forming basic motor memories. Previous work has shown that physical practice (PP) results in cortical motor representational changes, referred to as use-dependent plasticity (UDP), and that AO combined with PP potentiates UDP in both healthy adults and stroke patients. In humans, AO results in activation of the ventral premotor cortex (PMv), however, whether this PMv activation has a functional contribution to UDP is not known. Here, we studied the effects disruption of PMv has on UDP when subjects performed PP combined with AO (PP + AO). Subjects participated in two randomized crossover sessions measuring the amount of UDP resulting from PP + AO while receiving disruptive (1 Hz) TMS over the fMRI-activated PMv or over frontal cortex (Sham). We found that, unlike the sham session, disruptive TMS over PMv reduced the beneficial contribution of AO to UDP. To ensure that disruption of PMv was specifically interfering with the contribution of AO and not PP, subjects completed two more control sessions where they performed only PP while receiving disruptive TMS over PMv or frontal cortex. We found that the magnitude of UDP for both control sessions was similar to PP + AO with TMS over PMv. These findings suggest that the fMRI activation found in PMv during AO studies is functionally relevant to task performance, at least for the beneficial effects that AO exerts over motor training.
Climatological Mean Circulation at the New England Shelf Break
Authors: Zhang Weifeng G. , Gawarkiewicz Glen G. , McGillicuddy Dennis J. , Wilkin John L.
Published: May 2011

A two-dimensional cross-shelf model of the New England continental shelf and slope is used to investigate the mean cross-shelf and vertical circulation at the shelf break and their seasonal variation. The model temperature and salinity fields are nudged toward climatology. Annual and seasonal mean wind stresses are applied on the surface in separate equilibrium simulations. The along-shelf pressure gradient force associated with the along-shelf sea level tilt is tuned to match the modeled and observed depth-averaged along-shelf velocity. Steady-state model solutions show strong seasonal variation in along-shelf and cross-shelf velocity, with the strongest along-shelf jet and interior onshore flow in winter, consistent with observations. Along-shelf sea level tilt associated with the tuned along-shelf pressure gradient increases shoreward because of decreasing water depth. The along-shelf sea level tilt varies seasonally with the wind and is the strongest in winter and weakest in summer. A persistent upwelling is generated at the shelf break with a maximum strength of 2 m day−1 at 50-m depth in winter. The modeled shelfbreak upwelling differs from the traditional view in that most of the upwelled water is from the upper continental slope instead of from the shelf in the form of a detached bottom boundary layer.
Climate Sensitivity to Changes in Ocean Heat Transport
Authors: Barreiro Marcelo , Cherchi Annalisa , Masina Simona
Published: May 2011

Using an atmospheric general circulation model coupled to a slab ocean, the effects of ocean heat transport (OHT) on climate are studied by prescribing OHT from 0 to 2 times the present-day values. In agreement with previous studies, an increase in OHT from zero to present-day conditions warms the climate by decreasing the albedo due to reduced sea ice extent and marine stratus cloud cover and by increasing the greenhouse effect through a moistening of the atmosphere. However, when the OHT is further increased, the solution becomes highly dependent on a positive radiative feedback between tropical low clouds and sea surface temperature. The strength of the low cloud–SST feedback combined with the model design may produce solutions that are globally colder than in the control run, mainly due to an unrealistically strong equatorial cooling. Excluding those cases, results indicate that the climate warms only if the OHT increase does not exceed more than 10% of the present-day value in the case of a strong cloud–SST feedback and more than 25% when this feedback is weak. Larger OHT increases lead to a cold state where low clouds cover most of the deep tropics, increasing the tropical albedo and drying the atmosphere. This suggests that the present-day climate is close to a state where the OHT maximizes its warming effects on climate and raises doubts about the possibility that greater OHT in the past may have induced significantly warmer climates than that of today.
A Dynamical Performance-Ranking Method for Predicting Individual Ensemble Member Performance and Its Application to Ensemble Averaging
Authors: Du Jun , Zhou Binbin
Published: May 2011

This study proposes a dynamical performance-ranking method (called the Du–Zhou ranking method) to predict the relative performance of individual ensemble members by assuming the ensemble mean is a good estimation of the truth. The results show that the method 1) generally works well, especially for shorter ranges such as a 1-day forecast; 2) has less error in predicting the extreme (best and worst) performers than the intermediate performers; 3) works better when the variation in performance among ensemble members is large; 4) works better when the model bias is small; 5) works better in a multimodel than in a single-model ensemble environment; and 6) works best when using the magnitude difference between a member and its ensemble mean as the “distance” measure in ranking members. The ensemble mean and median generally perform similarly to each other.

This method was applied to a weighted ensemble average to see if it can improve the ensemble mean forecast over a commonly used, simple equally weighted ensemble averaging method. The results indicate that the weighted ensemble mean forecast has a smaller systematic error. This superiority of the weighted over the simple mean is especially true for smaller-sized ensembles, such as 5 and 11 members, but it decreases with the increase in ensemble size and almost vanishes when the ensemble size increases to 21 members. There is, however, little impact on the random error and the spatial patterns of ensemble mean forecasts. These results imply that it might be difficult to improve the ensemble mean by just weighting members when an ensemble reaches a certain size. However, it is found that the weighted averaging can reduce the total forecast error more when a raw ensemble-mean forecast itself is less accurate. It is also expected that the effectiveness of weighted averaging should be improved when the ensemble spread is improved or when the ranking method itself is improved, although such an improvement should not be expected to be too big (probably less than 10%, on average).
Improved Representation of Boundary Layer Clouds over the Southeast Pacific in ARW-WRF Using a Modified Tiedtke Cumulus Parameterization Scheme*
Authors: Zhang Chunxi , Wang Yuqing , Hamilton Kevin
Published: May 2011

A modified Tiedtke cumulus parameterization (CP) scheme has been implemented into the Advanced Research Weather Research and Forecasting model (ARW-WRF) to improve the representation of marine boundary layer (MBL) clouds over the southeast Pacific (SEP). A full month simulation for October 2006 was performed by using the National Centers for Environmental Prediction (NCEP) final analysis (FNL) as both the initial and lateral boundary conditions and the observed sea surface temperature (SST). The model simulation was compared with satellite observations and with results from an intense ship-based campaign of balloon soundings during 16–20 October 2006 at 20°S, 85°W.

The model with the modified Tiedtke scheme successfully captured the main features of the MBL structure and low clouds over the SEP, including the geographical distribution of MBL clouds, the cloud regime transition, and the vertical structure of the MBL. The model simulation was repeated with the various CP schemes currently provided as standard options in ARW-WRF. The simulations with other CP schemes failed to reproduce the geographical distribution of cloud fraction and the observed cloud regime transition, and displayed an MBL too shallow compared to observations. The improved simulation with the modified Tiedtke scheme can be attributed to a more active parameterized shallow convection with the modified Tiedtke scheme than with the other CP schemes tested, which played a critical role in lifting the inversion base and the low cloud layer. Results from additional sensitivity experiments employing different planetary boundary layer (PBL) parameterization schemes demonstrated that the basic feature of the MBL structure and low clouds over the SEP were not particularly sensitive to the choice of the PBL scheme.
The Low-Level Atmospheric Circulation near Tongoy Bay–Point Lengua de Vaca (Chilean Coast, 30°S)
Authors: Rahn David A. , Garreaud René D. , Rutllant José A.
Published: May 2011

Strong southerly, terrain parallel winds often occur along the coast of north-central Chile (25°–35°S) embedded in the marine atmospheric boundary layer and the lower part of the capping temperature inversion. Their offshore structure and variability have received considerable attention because of the effect on open-ocean processes and connection with the southeast Pacific cloud layer. Mesoscale low-level circulations linked to the coastal topography (e.g., coastal jets and sea breeze) are less studied in Chile, but are particularly relevant as they alter the upper-ocean circulation and the cloud pattern in the nearshore strip.

Surface, radiosonde, and airborne meteorological observations near point Lengua de Vaca (LdV)–Tongoy Bay (TB) at 30°S are used alongside numerical modeling to understand the local circulation near a prominent upwelling center. Most observations were gathered during the Variability of the American Monsoon Systems (VAMOS) Ocean–Cloud–Atmosphere–Land Study Chilean Upwelling Experiment (VOCALS-CUpEx) during two weeks in late spring 2009. The regional topography resembles other major capes, but south of TB and east of LdV there is a low (100–300 m), dry marine terrace bounded by high elevation at the coast (~600 m) and farther inland. Coastal soundings 25 km upstream of LdV revealed a southerly wind maximum near the surface and another at 900 m separated by a destabilized layer, deviating from the two-layer model often applied to coastal flow. In the morning a shallow sea breeze penetrates from TB to the marine terrace, but is overridden by southerly flow in the afternoon. Furthermore, between 400 and 900 m, warm continental air is advected from over the marine terrace creating a residual boundary layer over TB. Concurrent with slower changes offshore, the low-level warming over TB leads to a marked cross-shore pressure gradient enhancing the coastal jet just north of LdV.
General or Local Anesthesia for Carotid Endarterectomy—The “Real-World” Experience
Authors: Sideso E. , Walton J. , Handa Ashok
Published: May 2011

Perioperative complications from carotid endarterectomy (CEA) are the main drawbacks of the procedure. The aim of this study was to assess the complication rates in patients undergoing CEA under general anesthesia (GA) or regional anesthesia (local anesthesia [LA]) at our institution. Patients undergoing CEA at our regional vascular unit between 2000 and 2004 were included. Data were collated retrospectively from a prospective database. Follow-up was up to 62 months. In all, 383 endarterectomies were performed, 260 of which were under LA. Outcome measures included 30-day death (2.1%), stroke (1.8%), and combined stroke and death (2.8%). A 30-day incidence of stroke, death, and combined stroke and death was lower in the LA group. Incidence of myocardial infarction and transient ischemic attacks, and annual mortality were higher in the LA group. No significant difference was found between the 2 groups. In a unit where CEA is preferentially performed under LA, anesthesia technique failed to significantly influence outcome.
Changes in Plasma Level of Heat Shock Protein 27 After Acute Coronary Syndrome
Authors: Heidari-Bakavoli Ali Reza , Sahebkar Amirhossein , Mobara Naser , Moohebati Mohsen , Tavallaie Shima , Rahsepar Amir Ali , Kazemi Abolfazl , Alavi Maryam-Sadat , Ghayour-Mobarhan Majid , Ferns Gordon AA
Published: May 2011

We assessed the association between serum heat shock protein 27 (Hsp-27)concentrations in patients with acute coronary syndrome (ACS) and compared them with healthy participants. Patients with ACS (n = 75) were recruited and their biochemical parameters were compared with 75 healthy participants. Heat shock protein 27 concentrations were measured from blood samples taken on admission and 12 hours after the onset of chest pain. In the patient group, Hsp-27 concentrations (31.62 [20.12-38.51] ng/mL) in the first blood samples were significantly ( P < .001) higher than in control samples (20.12 [16.67-28.17] ng/mL). In patients, serum Hsp-27 levels on admission were significantly ( P < .001) higher than for the samples collected 12 hours after the onset of chest pain (25.87 [15.52-31.62]); the latter did not differ significantly from samples of healthy controls. In conclusion, serum Hsp-27 concentrations are elevated in the early hours following ACS, but fall to levels near to those in healthy individuals after about 12 hours from the onset of chest pain.
High-Sensitivity C-Reactive Protein is a Predictor of In-Hospital Cardiac Events in Acute Myocardial Infarction Independently of GRACE Risk Score
Authors: Raposeiras-Roubín Sergio , Pardal Cristina Barreiro , Janeiro Bruno Rodiño , Abu-Assi Emad , García-Acuña José María , González-Juanatey José Ramón
Published: May 2011

High-sensitivity CRP (hsCRP) is being increasingly used as a marker for cardiac risk assessment and as a prognostic tool in acute coronary syndrome. We analyzed the relation between hsCRP values at admission and in-hospital outcomes in 98 consecutive patients with acute myocardial infarction (AMI) undergoing catheterization. Patients with cardiac events had more advanced Killip class, more proportion of depressed left ventricular ejection fraction (LVEF), higher Global Registry of Acute Coronary Events (GRACE) risk score, and higher hsCRP levels. High-sensitivity CRP and GRACE risk score showed a significant positive correlation ( r = .320, P = .002). In multivariate analysis, hsCRP resulted as a predictor of worse in-hospital outcomes independently of GRACE risk score (OR 1.122, CI95%:1.005-1.252, P = .040). The hsCRP value showing the maximum likelihood ratio for predicting cardiac events was 1.45 mg/dL. High levels of hsCRP were also associated with development of contrast-induced nephropathy but not with bleeding events.
Some Aspects of Preventing Coronary Heart Disease
Authors: Agewall Stefan
Published: May 2011

Coronary heart disease (CHD) is the leading cause of mortality in the industrialized world and that might also soon be the case in other parts of the world. There are several easily measured and potentially modifiable risk factors that account for a substantial proportion of the risk of CHD. The effect of risk factors interventions appears to be consistent in both genders, across different geographic regions, and by all ethnic groups, suggesting that approaches to prevention can be based on similar principles worldwide. Optimal target levels for serum cholesterol and blood pressure are not yet clear. Future risk CHD reduction will mainly be achieved by improved primary prevention.
Prevalence of Metabolic Syndrome According to Different Definitions in a Hypertensive Population
Authors: Lioudaki Eirini , Vrentzos George E. , Mavrogeni Helen , Zeniodi Maria-Helen , Ganotakis Emmanuel S. , Mikhailidis Dimitri P. , Papadakis John A.
Published: May 2011

Aims: The metabolic syndrome (MetS) is associated with increased risk of cardiovascular disease (CVD) and diabetes mellitus (DM). Several definitions of MetS have been proposed. The aim of the present study was to estimate and compare the prevalence of MetS according to the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III), American Heart Association-National Heart Lung and Blood Institute (AHA-NHLBI), International Diabetes Federation (IDF) and the more recent Joint Interim Statement (JIS) definitions in patients attending a hypertension clinic. Methods: The records of patients referred to the hypertension clinic at the University Hospital (Heraklion, Crete) from January 2001 to June 2009 were screened retrospectively. A total 384 patients (146 men) were included in the study. Results: The prevalence of MetS according to the IDF and JIS definitions was significantly higher compared with that of the NCEP ATP III in both genders (IDF: P = .009 and P = .002, JIS: P = .002 and P = 0.001 for men and women, respectively); this was the case for the AHA-NHLBI definition only among women ( P = .03). All MetS components differed significantly ( P from < .0001 to .02) between patients with and without MetS for all definitions. Conclusions: The prevalence of MetS varies considerably depending on the definition used in a hypertensive population in a Mediterranean country. These differences will influence risk assessment.
Relationship Between White Blood Cell Count and In-Hospital Outcomes in Acute Coronary Syndrome Patients From the Middle East
Authors: Sulaiman Kadhim , Al-Zakwani Ibrahim , Panduranga Prashanth , Al-Suwaidi Jassim , Alsheikh-Ali Alawi A. , Mahmeed Wael Al , Amin Haitham , Al-Mutarreb Ahmed , AlHabib Khalid , Al-Lawati Jawad , Zubaid Mohammed
Published: May 2011

We evaluated the relationship between admission white blood cell (WBC) count and in-hospital outcomes in acute coronary syndrome (ACS) patients from the Middle East. Data were analyzed from 7806 consecutive patients with ACS who were divided into 4 groups (G) according to their WBC count (×109/L; G1: <6.00; G2: 6.00-9.99; G3: 10.00-11.99; G4: ≥12.00). After significant covariate adjustment, those in G4 were 68% more likely to have cardiogenic shock than those in G1 (95% confidence interval [CI]: 1.05-2.68; P = .030) and G2 (odds ratio [OR], 2.02; 95% CI: 1.51-2.71; P < .001). Those in G4 were 2.02 times (95% CI: 1.11-3.67; P = .021) and 65% (95% CI: 1.17-2.32; P = .004) more likely to die in hospital than those in G1 and G2, respectively. Admission WBC count is an independent risk factor for in-hospital cardiogenic shock and mortality, in Middle Eastern patients with ACS. Novel therapeutic agents targeting WBCs in patients with ACS may improve outcomes.
Investigation on mechanical properties of nano-Al2O3-reinforced aluminum matrix composites
Authors: Mazahery Ali , Ostadshabani Mohsen
Published: May 2011

In this study, 0.75, 1.5, 2.5, 3.5, and 5 vol.% of alumina nanoparticles were incorporated into the A356 aluminum alloy by a mechanical stirrer and then, cylindrical specimens were cast at 800°C and 900°C. A uniform distribution of reinforcement, grain refinement of aluminum matrix, and presence of the minimal porosity was observed by microstructural characterization of the composite samples. Characterization of mechanical properties revealed that the presence of nanoparticles significantly increased compressive and tensile flow stress at both casting temperatures. The highest compressive flow stress was obtained by 2.5 vol.% of Al2O3 nanoparticles. It is then observed that the flow stress decreases when Al2O3 concentration increased further to 5 vol.% irrespective of the amount of deformation and casting temperature. It was revealed that the presence of nano-Al2O3 reinforcement led to significant improvement in 0.2% yield strength and ultimate tensile stress while the ductility of the aluminum matrix is retained. Fractography examination showed relatively ductile fracture in tensile-fractured samples.
The Role of Societal Cultural Practices in Organizational Investment in Training: A Comparative Study in 21 Countries
Authors: Peretz Hilla , Rosenblatt Zehava
Published: May 2011

The role of cultural practices on the level of organizational investment in training, with the added effect of key organizational background characteristics (size and technological level), was explored. Secondary analysis was conducted on the data of project GLOBE (Global Leadership and Organizational Effectiveness) and of CRANET (Cross-Country Human Resource Management Research), covering 5,991 organizations and 21 countries. Controlled for organization size and technology level, as well as economic strength (GNI), cultural practices such as low power distance, high future orientation, and high uncertainty avoidance explained increased investment in training, supporting the study hypotheses. Organizational characteristics were also related to investment in training: Larger size and high (vs. low) technology predicted increased investment. The two organizational background characteristics interacted with national values, so the above effects of uncertainty avoidance and future orientation were higher, respectively, for larger organizations and high-tech organizations. Implications are particularly relevant for diverse organizations, which encourage the employment of a diverse workforce, and for international organizations, which tend to emphasize a global organizational culture and standard organizational practices while underestimating local cultural values.
Short-term Teriparatide Delivery and Osseointegration: a Clinical Feasibility Study
Authors: Kuchler U. , Luvizuto E.R. , Tangl S. , Watzek G. , Gruber R.
Published: May 2011

Teriparatide is an anabolic osteoporosis therapeutic agent that can improve healing after fractures and periodontal surgeries. Clinical studies investigating the effects of teriparatide on the osseointegration of titanium implants have not been performed. We conducted an open-label randomized controlled feasibility study and included 24 individuals with edentulous lower jaws. The participants received 2 study implants in the mandible during interforaminal dental implant surgery. They were randomly assigned to receive either 20 µg of teriparatide once daily for 28 days or no treatment. Study implants were retrieved from 23 participants after 9 weeks and were subjected to histomorphometric analyses. Endpoints were new bone-volume-per-tissue-volume (NBV/TV) and new bone-to-implant-contact (NBIC). We report here that median values of NBV/TV in the control and the teriparatide groups were 15.4% vs. 17.6% in the periosteal compartment, 11.3% vs. 16.5% in the cortical compartment, and 7.3% vs. 12.0% in the medullary compartment, respectively. NBIC median values in the control and the teriparatide groups were 3.3% vs. 4.1% in the periosteal compartment, 5.0% vs. 4.4% in the cortical compartment, and 0.3% vs. 1.4% in the medullary compartment, respectively. The results provide the first histological data on the osseointegration of titanium study implants in individuals treated with teriparatide. ClinicalTrials.gov number, NCT00089674.

Abbreviations: NBV/ TV, new bone-volume per tissue volume; NBIC, new bone-to-implant contact; BV/TV, bone-volume per tissue volume; BIC, bone-to-implant contact; ROI, region of interest.
Improving Fatigue Damage Resistance of Alumina through Surface Grading
Authors: Ren L. , Liu L. , Bhowmick S. , Gerbig Y.B. , Janal M.N. , Thompson V.P. , Zhang Y.
Published: May 2011

Porcelain-veneered alumina crown restorations often fail from bulk fracture resulting from radial cracks that initiate at the cementation surface with repeated flexure of the stiffer crown layers on the soft dentin support. We hypothesized that bulk fracture may be substantially mitigated by grading the elastic modulus at the crown surfaces. In this study, we fabricated graded structures by infiltrating glass into dense alumina plates, resulting in a diminished modulus at the surface layers. The plates were then bonded to polycarbonate substrates and subjected to fatigue loading in water. Tests were terminated when fracture occurred at the cementation tensile surface or at the fatigue endurance limit (1 million cycles). Infiltrated specimens showed a significant increase in fatigue fracture loads over non-infiltrated controls. Our results indicate that controlled elastic gradients at the surface could be highly beneficial in the design of fracture-resistant alumina crowns.
Appreciation of Rollo May
Authors: Peng Jason H.
Published: May 2011

A tribute to Rollo May, the present essay is the result of an extended and passionate effort to embrace the work of the great psychologist. Amid a welter of voices in “new existentialism,” Rollo May continues to inspire a deeper exploration of being founded on awareness, character, and struggle.
Military Identities in the Situated Accounts of British Military Personnel
Authors: Woodward Rachel , Neil Jenkings K.
Published: May 2011

This article examines individual military identities as articulated by serving and former British military personnel. Following a review of approaches to military identities in both traditional military sociology and more contemporary sociologies of military personnel informed by post-structuralist theories, the article introduces a methodological approach to identities driven by respondents’ perspectives generated during photo-elicitation interviews. These constructions of military identities rest on: the assertions and demonstrations of professional skill, competence and expertise of the trained military operative; the significance of fictive kinship and camaraderie amongst soldiers; and the place in identity work of personal participation in events of national or global significance. Military identity, we argue, is a locally emergent phenomenon, constituted by members’ concepts of their own identity. These findings complement and develop existing sociological conceptualizations of military identities.
Sociological Ambivalence Revisited
Authors: Hillcoat-Nallétamby Sarah , Phillips Judith E.
Published: May 2011

The concept of ambivalence has received limited attention from contemporary sociologists, notably because of its association with psychoanalysis and psychology and their emphasis on individual experience in isolation from the broader social and cultural contexts to which people belong. This article revisits the concept by placing it within a framework of relational sociology with the purpose of strengthening its conceptual foundations as a sociological construct. We illustrate the foundations of this framework through analysis of narratives collected as part of the project ‘Old age and autonomy: The role of service systems and intergenerational family solidarity’, involving interviews with adult children and their ageing parents engaged in informal caring relationships. Viewed through a relational lens, ambivalence can be reconceptualized as having both temporal and transformative properties and as the product of complex relational experiences existing within a wider web of interdependent social relationships.
Political Distinction in the British Anti-capitalist Movement
Authors: Ibrahim Yousaf
Published: May 2011

This article argues that Bourdieu’s theory of practice provides a useful and dynamic framework which may be used to examine the reproduction of political practice. I use the Bourdieusian theoretical model to analyse and interpret data collected from 30 semi-structured interviews with British anti-capitalist activists from a range of anarchist and socialist political organizations and networks. The interviews reveal a clear case of political distinction between anarchists and socialists. The political history, political methods, and ideology of the activists become embodied and routinized over time. This explains why and how there is a durable ideological division which is consistently reproduced over and over again within sections of the British anti-capitalist movement.
Social Networks and Occupational Attainment in Australia
Authors: Xianbi Huang  , Western Mark
Published: May 2011

This article contributes to exploring the comparative effects of market mechanisms and social networks and the interplay of human capital and social networks in western labour markets. We examine social networks and occupational attainment by using data from the 2007 Australian Survey of Social Attitudes and provide three major findings: (1) as a job search method, social networks are associated with lower earnings and occupational status and a lower probability of entering a professional or managerial position than market-oriented job search methods; (2) jobs that are found using strong ties have lower occupational attainment than jobs found using weak ties; and (3) the poorer occupational attainment outcomes associated with social networks are only observed among those without university degrees.
Development of auxetic fabrics using flat knitting technology
Authors: Hong Hu  , Zhengyue Wang  , Su Liu
Published: May 2011

Flat knitting is a widely used fabric manufacturing technology. Compared with warp knitting and circular knitting, flat knitting is characterized by its higher process flexibility and greater fabric structure variety. In this work, flat knitting technology was exploited to fabricate auxetic fabrics which laterally expand when stretched. Three kinds of geometrical structures, i.e. foldable structure, rotating rectangle and reentrant hexagon, were employed as basic reference structures for the development of these kinds of auxetic fabrics. The weft knitting processes based on these structures were specially developed and auxetic fabrics were fabricated using the computerized flat knitting machines. The Poisson’s ratio-strain curves of the developed fabrics were plotted and compared with those calculated using existing models to demonstrate the variation trends of Poisson’s ratio with the axial strain. The results reveal that except the folded fabric formed with the face loops and reverse loops in a rectangular arrangement, of which the auxetic effect firstly increases and then decreases with the axial strain, the auxetic effects of all other fabrics decrease with an increase of the axial strain. The work also shows that auxetic fabrics can be realized based on knitted structures and that flat knitting technology can provide a simple, but highly effective way of fabricating auxetic fabrics from conventional yarns.