bluuebunny/crossref_metadata_2025 huggingface dataset:
The Extent of Left Ventricular Scar Quantified by Late Gadolinium Enhancement MRI Is Associated With Spontaneous Ventricular Arrhythmias in Patients With Coronary Artery Disease and Implantable Cardioverter-Defibrillators
Authors: Scott Paul A. , Morgan John M. , Carroll Nicola , Murday David C. , Roberts Paul R. , Peebles Charles R. , Harden Stephen P. , Curzen Nick P.
Published: April 2011

Background—

Characterization of sudden cardiac death (SCD) risk remains a challenge in the application of implantable cardioverter-defibrillator (ICD) therapy. Late gadolinium enhancement cardiac MRI (LGE-CMR) can accurately identify myocardial scar. We performed a retrospective, single-center observational study to evaluate the association between the extent and distribution of left ventricular scar, quantified using LGE-CMR, and the burden of ventricular arrhythmias in patients with coronary artery disease and ICDs.

Methods and Results—

All patients included (2006 to 2009) had undergone LGE-CMR before ICD implantation. Scar (defined as myocardium with a signal intensity ≥50% of the maximum in scar tissue) was characterized in terms of percent scar, scar surface area, and number of transmural left ventricular scar segments. The end point was appropriate ICD therapy. Sixty-four patients (mean age, 66±11 years; male sex, 51) were included. During 19±10 months follow-up, appropriate ICD therapy occurred in 19 (30%) patients. In Cox regression analyses, both percent scar (hazard ratio per 10%, 1.75; 95% CI, 1.09 to 2.81;
P
=0.02) and number of transmural scar segments (hazard ratio per segment, 1.40; 95% CI, 1.15 to 1.70;
P
=0.001) were significantly associated with the occurrence of appropriate ICD therapy.

Conclusions—

In this pilot study, the extent of myocardial scar characterized by LGE-CMR was significantly associated with the occurrence of spontaneous ventricular arrhythmias. We hypothesize that scar quantification by LGE-CMR may prove a valuable risk stratification tool for the occurrence of ventricular arrhythmias, which may have implications for patient selection for ICD therapy.
Utility of the Ventricular Fibrillation Waveform to Predict a Return of Spontaneous Circulation and Distinguish Acute From Post Myocardial Infarction or Normal Swine in Ventricular Fibrillation Cardiac Arrest
Authors: Indik Julia H. , Allen Daniel , Gura Michael , Dameff Christian , Hilwig Ronald W. , Kern Karl B.
Published: April 2011

Background—

In cardiac arrest, the ventricular fibrillation (VF) waveform, particularly amplitude spectral area (AMSA) and slope, predicts the return of spontaneous circulation (ROSC), but it is unknown whether the predictive utility differs in an acute myocardial infarction (MI), prior MI, or normal myocardium and if the waveform can distinguish the underlying myocardial state. We hypothesized that in a swine model of VF cardiac arrest, AMSA and slope predict ROSC after a shock independent of substrate and distinguish an acute from nonacute MI state.

Methods and Results—

MI was induced by occlusion of the left anterior descending artery. Post MI swine recovered for a 2-week period before induction of VF. VF was untreated for 8 minutes in 10 acute MI, 10 post MI, and 10 control swine. AMSA and slope predicted ROSC after a shock independent of myocardial state. For AMSA >31 mV-Hz, the odds ratio was 62 (
P
≤0.001) compared with AMSA <19 mV-Hz. For slope >3.1 mV/s, odds ratio was 52 (
P
≤0.001) compared with slope <1.8 mV/s. With chest compressions, AMSA and slope were significantly lower for acute MI swine compared with control swine, whereas in post MI swine the waveform characteristics were similar to control swine. In particular, for an AMSA >33.5 mV-Hz, the sensitivity to identify an acute from nonacute (control or post MI) state was 83%.

Conclusions—

In a swine model of VF cardiac arrest, AMSA and slope predict ROSC independent of myocardial substrate. Furthermore, with chest compressions, the VF waveform evolves differently and may offer a means to distinguish an acute MI.
Natural History and Long-Term Outcomes of Ablated Atrial Fibrillation
Authors: Hussein Ayman A. , Saliba Walid I. , Martin David O. , Bhargava Mandeep , Sherman Minerva , Magnelli-Reyes Christina , Chamsi-Pasha Mohammed , John Seby , Williams-Adrews Michelle , Baranowski Bryan , Dresing Thomas , Callahan Thomas , Kanj Mohamed , Tchou Patrick , Lindsay Bruce D. , Natale Andrea , Wazni Oussama
Published: April 2011

Background—

Atrial fibrillation (AF) ablation is increasingly used in clinical practice. We aimed to study the natural history and long-term outcomes of ablated AF.

Methods and Results—

We followed 831 patients after pulmonary vein isolation (PVI) performed in 2005. We documented clinical outcomes using our prospective AF registry with most recent update on this group of patients in October 2009. In the first year after ablation, 23.8% had early recurrence. Over long-term follow-up (55 months), only 8.9% had late arrhythmia recurrence defined as occurring beyond the first year after ablation. Repeat ablations in patients with late recurrence revealed conduction recovery in at least 1 of the previously isolated PVs in all of them and right-sided triggers with isoproterenol testing in 55.6%. At last follow-up, clinical improvement was 89.9% (79.4% arrhythmia-free off antiarrhythmic drugs and 10.5% with AF controlled with antiarrhythmic drugs). Only 4.6% continued to have drug-resistant AF. It was possible to safely discontinue anticoagulation in a substantial proportion of patients with no recurrence in the year after ablation (CHADS score ≤2, stroke incidence of 0.06% per year). The procedure-related complication rate was very low.

Conclusions—

Pulmonary vein isolation is safe and efficacious for long-term maintenance of sinus rhythm and control of symptoms in patients with drug-resistant AF. It obviates the need for antiarrhythmic drugs, negative dromotropic agents, and anticoagulants in a substantial proportion of patients.
Syndecan-4 Prevents Cardiac Rupture and Dysfunction After Myocardial Infarction
Authors: Matsui Yutaka , Ikesue Masahiro , Danzaki Keiko , Morimoto Junko , Sato Mami , Tanaka Shinya , Kojima Tetsuhito , Tsutsui Hiroyuki , Uede Toshimitsu
Published: April 2011

Rationale:

Syndecan-4 (Syn4), a cell-surface heparan sulfate proteoglycan, has been detected in the infarct region after myocardial infarction (MI), but its functional significance has not been elucidated.

Objective:

We examined whether and how Syn4 regulates the cardiac healing process after MI.

Methods and Results:

Although the heart in Syn4-deficient (Syn4
−/−
) mice was morphologically and functionally normal, Syn4
−/−
mice exhibited impaired heart function and increased mortality rate as a result of cardiac ruptures after MI. Cardiac ruptures in Syn4
−/−
mice were associated with reduced inflammatory reaction and impaired granulation tissue formation during the early phase of MI, as evidenced by reduced numbers of leukocytes, fibroblasts, myofibroblasts, macrophages, and capillary vessels, along with reduced extracellular matrix protein deposition in the infarct region after MI. Transforming growth factor-β1–dependent cell signaling was preserved, whereas cell migration, fibronectin-induced cell signaling, and differentiation into myofibroblasts were defective in Syn4
−/−
cardiac fibroblasts. We also found that Syn4 was involved in basic fibroblast growth factor–dependent endothelial cell signaling, cell proliferation, and tube formation. Finally, overexpression of the shed form of Syn4 before MI creation led to an increase in mortality due to cardiac rupture via its action as a dominant-negative inhibitor of endogenous Syn4 signaling, which suggested a protective role of Syn4 signaling in MI.

Conclusions:

These results suggest that Syn4 plays an important role in the inflammatory response and granulation tissue formation, thereby preventing cardiac rupture and dysfunction after MI.
Mast Cell Tryptase Deficiency Attenuates Mouse Abdominal Aortic Aneurysm Formation
Authors: Zhang Jie , Sun Jiusong , Lindholt Jes S. , Sukhova Galina K. , Sinnamon Mark , Stevens Richard L. , Adachi Roberto , Libby Peter , Thompson Robert W. , Shi Guo-Ping
Published: April 2011

Rationale:

Mast cells (MCs) contribute to the formation of abdominal aortic aneurysms (AAAs) by producing biologically active mediators. Tryptase is the most abundant MC granule protein and participates in MC activation, protease maturation, leukocyte recruitment, and angiogenesis—all processes critical to AAA pathogenesis.

Objective:

To test the hypothesis that tryptase participates directly in AAA formation.

Methods and Results:

Immunohistochemistry demonstrated enhanced tryptase staining in media and adventitia of human and mouse AAA lesions. Serum tryptase levels correlated significantly with the annual expansion rate of AAA before (
r
=0.30,
P
=0.003) and after (
r
=0.29,
P
=0.005) adjustment for common AAA risk factors in a patient follow-up study, and associated with risks for later surgical repair or overall mortality before (
P
=0.009,
P
=0.065) and after (
P
=0.004,
P
=0.001) the adjustment. Using MC protease-6–deficient mice (
Mcpt6
−/−
) and aortic elastase perfusion-induced experimental AAAs, we proved a direct role of this tryptase in AAA pathogenesis. Whereas all wild-type (WT) mice developed AAA at 14 or 56 days postperfusion,
Mcpt6
−/−
mice were fully protected. AAA lesions from
Mcpt6
−/−
mice had fewer inflammatory and apoptotic cells, and lower chemokine levels, than did those from WT mice. MC from WT mice restored reduced AAA lesions and lesion inflammatory cell content in MC–deficient

Kit
W-sh/W-sh

mice, but those prepared from
Mcpt6
−/−
mice did not. Mechanistic studies demonstrated that tryptase deficiency affected endothelial cell (EC) chemokine and cytokine expression, monocyte transmigration, smooth-muscle cell apoptosis, and MC and AAA lesion cysteinyl cathepsin expression and activities.

Conclusions:

This study establishes the direct participation of MC tryptase in the pathogenesis of experimental AAAs, and suggests that levels of this protease can serve as a novel biomarker for abdominal aortic expansion.
The Transcription Factor HOXC9 Regulates Endothelial Cell Quiescence and Vascular Morphogenesis in Zebrafish via Inhibition of Interleukin 8
Authors: Stoll Sandra J. , Bartsch Susanne , Augustin Hellmut G. , Kroll Jens
Published: April 2011

Rationale:

The transcription factor HOXC9 belongs to the homeobox gene family acting as developmental morphogen in several species. HOXC9 is expressed in different vascular beds in vivo. Yet vascular functions of HOXC9 have not been studied.

Objective:

This study was aimed at characterizing HOXC9 functions in human vascular endothelial cells and in zebrafish vascular development.

Methods and Results:

HOXC9 was abundantly expressed in resting human umbilical vein endothelial cells and was downregulated by hypoxia. Overexpression of HOXC9 inhibited endothelial cell proliferation, migration, and tube formation in vitro. Expression profiling and chromatin immunoprecipitation experiments in human umbilical vein endothelial cells identified interleukin 8 as the major HOXC9 target and demonstrated the direct binding of HOXC9 to the interleukin 8 promotor. HOXC9 overexpression led to reduced endothelial interleukin 8 production, whereas HOXC9 silencing increased interleukin 8. The antimigratory and antiangiogenic effect of HOXC9 overexpression could be rescued by external interleukin 8 administration. Corresponding to the cellular experiments, endothelial-specific overexpression of HOXC9 and morpholino-based interleukin 8 loss-of-function experiments inhibited zebrafish vascular development.

Conclusion:

The data identify HOXC9 as an endothelial cell active transcriptional repressor promoting the resting, antiangiogenic endothelial cell phenotype in an interleukin 8–dependent manner.
A Phase II Multicentered, Single-Blind, Randomized, Controlled Trial of the Stroke Self-Management Program
Authors: Cadilhac Dominique A. , Hoffmann Sally , Kilkenny Monique , Lindley Richard , Lalor Erin , Osborne Richard H. , Batterbsy Malcolm
Published: April 2011

Background and Purpose—

The benefits of chronic disease self-management programs for stroke survivors are uncertain because individuals with severe impairments have been excluded from previous research. We undertook a phase II randomized controlled trial to determine whether a self-management program designed for survivors (SSMP; 8 weeks) was safe and feasible compared to standard care (control) or a generic self-management program (generic; 6 weeks).

Methods—

Stroke survivors were recruited from 7 South Australian hospitals via a letter or indirectly (eg, newspapers). Eligible participants were randomized at a 1:1:1 ratio of 50 per group. Primary outcomes were recruitment, participation, and participant safety. Secondary outcomes were positive and active engagement in life using the Health Education Impact Questionnaire and characteristics of quality of life and mood at 6 months from program completion.

Results—

Of 315 people screened, 149 were eligible and 143 were randomized (48 SSMP, 47 generic, 48 control); mean age was 69 years (SD, 11) and 59% were female. Demographic features were similar between groups and 41% had severe cognitive impairment; 57% accessed the interventions, with 52% SSMP and 38% generic completing >50% of sessions (
P
=0.18). Thirty-two participants reported adverse events (7 control, 12 generic, 13 SSMP;
P
=0.3; 34% severe); however, none was attributable to the interventions. Potential benefits for improved mood were found.

Conclusions—

SSMP was safe and feasible. Benefits of the stroke-specific program over the generic program included greater participation and completion rates. An efficacy trial is warranted given the forecast growth in the stroke population and improved survival trends.
Paradoxical Trends in the Management of Unruptured Cerebral Aneurysms in the United States
Authors: Huang Michael C. , Baaj Ali A. , Downes Katheryne , Youssef A. Samy , Sauvageau Eric , van Loveren Harry R. , Agazzi Siviero
Published: April 2011

Background and Purpose—

The objective of this study was to characterize demographics, treatments, and outcomes in the management of unruptured cerebral aneurysms in the United States using a national healthcare database.

Methods—

Clinical data were derived from the Nationwide Inpatient Sample for the years 1997 through 2006. Patients with unruptured cerebral aneurysms were identified using the appropriate International Classification of Diseases, 9th Revision code (437.3). Hospitalizations, length of stay, hospital charges, discharge pattern, age and gender distribution, and nature of intervention were analyzed. A Bureau of Labor statistics tool was used to adjust hospital and national charges for inflation. Population-adjusted rates were calculated using population estimates generated by the US Census Bureau.

Results—

Over 100 000 records were retrieved for analysis. During the time period studied, there was a 75% increase in the number of hospitalizations associated with unruptured cerebral aneurysms. Inflation adjusted hospital charges increased by 60%, whereas the total national bill increased by 200%. Overall, length of stay decreased by 37% and in-hospital mortality rates decreased by 54%. The increasing number of hospitalizations and total national charges related to inpatient treatment of unruptured aneurysms were significantly associated with endovascular treatment rather than surgical clipping.

Conclusions—

Despite recent studies suggesting a low risk of rupture of incidentally diagnosed cerebral aneurysms, data from this study suggest an increasing trend of treatment for this entity in the United States. Furthermore, endovascular intervention is now the major driving force behind the increasing overall national charges. Given the current healthcare climate, the impact of these trends warrants discussion and debate.
Patient Outcomes With Endovascular Embolectomy Therapy for Acute Ischemic Stroke
Authors: Brinjikji Waleed , Rabinstein Alejandro A. , Kallmes David F. , Cloft Harry J.
Published: April 2011

Background and Purpose—

Maturing techniques have spurred widespread implementation of endovascular embolectomy therapy for ischemic stroke. We evaluated a large administrative database to determine outcomes in patients treated with endovascular embolectomy in the general population.

Methods—

Using the National Inpatient Sample, we evaluated outcomes of patients treated for acute ischemic stroke in the United States from 2006 to 2008. Patients who had an ischemic stroke and underwent endovascular clot retrieval were identified. Morbidity, defined as “discharge to long-term facility,” and mortality were evaluated as a function of patient age and of concomitant thrombolytic agent administration.

Results—

For 2006 to 2008, a total of 3864 patients received endovascular clot retrieval with 266 (6.9%) patients in 2006, 800 (20.7) patients in 2007, and 2798 (72.4%) patients in 2008. The discharge to a long-term facility rate was 51.3% (1983 of 3864). The in-hospital mortality rate was 24.3% (940 of 3864). For patients <65 years old, the rate of in-hospital death was 17.1% (283 of 1658) as compared with a rate of 29.7% (656 of 2206) for patients ≥65 years old (
P
<0.0001). The rate of discharge to a long-term facility was 47.6% (789 of 1658) for patients <65 years old and 54.1% (1193 of 2206) for patients ≥65 years old (
P
<0.0001). The rate of intracranial hemorrhage was 15.5% without concomitant thrombolysis and 20.0% with concomitant thrombolysis (
P
=0.0009).

Conclusions—

Rates of morbidity and mortality remain high for patients with acute stroke, even in the setting of endovascular embolectomy. Advanced age portends a worse outcome and patients treated with concomitant use of thrombolytic agent had higher rates of intracranial hemorrhage than those without such therapy.
RAPID Automated Patient Selection for Reperfusion Therapy
Authors: Lansberg Maarten G. , Lee Jun , Christensen Soren , Straka Matus , De Silva Deidre A. , Mlynash Michael , Campbell Bruce C. , Bammer Roland , Olivot Jean-Marc , Desmond Patricia , Davis Stephen M. , Donnan Geoffrey A. , Albers Gregory W.
Published: April 2011

Background and Purpose—

The aim of this study was to determine if automated MRI analysis software (RAPID) can be used to identify patients with stroke in whom reperfusion is associated with an increased chance of good outcome.

Methods—

Baseline diffusion- and perfusion-weighted MRI scans from the Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution study (DEFUSE; n=74) and the Echoplanar Imaging Thrombolytic Evaluation Trial (EPITHET; n=100) were reprocessed with RAPID. Based on RAPID-generated diffusion-weighted imaging and perfusion-weighted imaging lesion volumes, patients were categorized according to 3 prespecified MRI profiles that were hypothesized to predict benefit (Target Mismatch), harm (Malignant), and no effect (No Mismatch) from reperfusion. Favorable clinical response was defined as a National Institutes of Health Stroke Scale score of 0 to 1 or a ≥8-point improvement on the National Institutes of Health Stroke Scale score at Day 90.

Results—

In Target Mismatch patients, reperfusion was strongly associated with a favorable clinical response (OR, 5.6; 95% CI, 2.1 to 15.3) and attenuation of infarct growth (10±23 mL with reperfusion versus 40±44 mL without reperfusion;
P
<0.001). In Malignant profile patients, reperfusion was not associated with a favorable clinical response (OR, 0.74; 95% CI, 0.1 to 5.8) or attenuation of infarct growth (85±74 mL with reperfusion versus 95±79 mL without reperfusion;
P
=0.7). Reperfusion was also not associated with a favorable clinical response (OR, 1.05; 95% CI, 0.1 to 9.4) or attenuation of lesion growth (10±15 mL with reperfusion versus 17±30 mL without reperfusion;
P
=0.9) in No Mismatch patients.

Conclusions—

MRI profiles that are associated with a differential response to reperfusion can be identified with RAPID. This supports the use of automated image analysis software such as RAPID for patient selection in acute stroke trials.
Inhibition in Superior Colliculus Neurons in a Brightness Discrimination Task?
Authors: Ratcliff Roger , Hasegawa Yukako T. , Hasegawa Ryohei P. , Childers Russ , Smith Philip L. , Segraves Mark A.
Published: April 2011

Simultaneous recordings were collected from between two and four buildup neurons from the left and right superior colliculi in rhesus monkeys in a simple two-choice brightness discrimination task. The monkeys were required to move their eyes to one of two response targets to indicate their decision. Neurons were identified whose receptive fields were centered on the response targets. The functional role of inhibition was examined by conditionalizing firing rate on a high versus low rate in target neurons 90 ms to 30 ms before the saccade and examining the firing rate in both contralateral and ipsilateral neurons. Two models with racing diffusion processes were fit to the behavioral data, and the same analysis was performed on simulated paths in the diffusion processes that have been found to represent firing rate. The results produce converging evidence for the lack of a functional role for inhibition between neural populations corresponding to the two decisions.
Determination and the No-Free-Lunch Paradox
Authors: Barnard Etienne
Published: April 2011

We discuss the no-free-lunch NFL theorem for supervised learning as a logical paradox—that is, as a counterintuitive result that is correctly proven from apparently incontestable assumptions. We show that the uniform prior that is used in the proof of the theorem has a number of unpalatable consequences besides the NFL theorem, and propose a simple definition of determination (by a learning set of given size) that casts additional suspicion on the utility of this assumption for the prior. Whereas others have suggested that the assumptions of the NFL theorem are not practically realistic, we show these assumptions to be at odds with supervised learning in principle. This analysis suggests a route toward the establishment of a more realistic prior probability for use in the extended Bayesian framework.
Spike-Timing-Dependent Plasticity and Reliability Optimization: The Role of Neuron Dynamics
Authors: Pool R. Rossi , Mato G.
Published: April 2011

Plastic changes in synaptic efficacy can depend on the time ordering of presynaptic and postsynaptic spikes. This phenomenon is called spike-timing-dependent plasticity (STDP). One of the most striking aspects of this plasticity mechanism is that the STDP windows display a great variety of forms in different parts of the nervous system. We explore this issue from a theoretical point of view. We choose as the optimization principle the minimization of conditional entropy or maximization of reliability in the transmission of information. We apply this principle to two types of postsynaptic dynamics, designated type I and type II. The first is characterized as being an integrator, while the second is a resonator. We find that, depending on the parameters of the models, the optimization principle can give rise to a wide variety of STDP windows, such as antisymmetric Hebbian, predominantly depressing or symmetric with one positive region and two lateral negative regions. We can relate each of these forms to the dynamical behavior of the different models. We also propose experimental tests to assess the validity of the optimization principle.
On the Simulation of Nonlinear Bidimensional Spiking Neuron Models
Authors: Touboul Jonathan
Published: April 2011

Bidimensional spiking models are garnering a lot of attention for their simplicity and their ability to reproduce various spiking patterns of cortical neurons and are used particularly for large network simulations. These models describe the dynamics of the membrane potential by a nonlinear differential equation that blows up in finite time, coupled to a second equation for adaptation. Spikes are emitted when the membrane potential blows up or reaches a cutoff θ. The precise simulation of the spike times and of the adaptation variable is critical, for it governs the spike pattern produced and is hard to compute accurately because of the exploding nature of the system at the spike times. We thoroughly study the precision of fixed time-step integration schemes for this type of model and demonstrate that these methods produce systematic errors that are unbounded, as the cutoff value is increased, in the evaluation of the two crucial quantities: the spike time and the value of the adaptation variable at this time. Precise evaluation of these quantities therefore involves very small time steps and long simulation times. In order to achieve a fixed absolute precision in a reasonable computational time, we propose here a new algorithm to simulate these systems based on a variable integration step method that either integrates the original ordinary differential equation or the equation of the orbits in the phase plane, and compare this algorithm with fixed time-step Euler scheme and other more accurate simulation algorithms.
A Connection Between Score Matching and Denoising Autoencoders
Authors: Vincent Pascal
Published: April 2011

Denoising autoencoders have been previously shown to be competitive alternatives to restricted Boltzmann machines for unsupervised pretraining of each layer of a deep architecture. We show that a simple denoising autoencoder training criterion is equivalent to matching the score (with respect to the data) of a specific energy-based model to that of a nonparametric Parzen density estimator of the data. This yields several useful insights. It defines a proper probabilistic model for the denoising autoencoder technique, which makes it in principle possible to sample from them or rank examples by their energy. It suggests a different way to apply score matching that is related to learning to denoise and does not require computing second derivatives. It justifies the use of tied weights between the encoder and decoder and suggests ways to extend the success of denoising autoencoders to a larger family of energy-based models.
Diagnosing Initial Condition Sensitivity of Typhoon Sinlaku (2008) and Hurricane Ike (2008)
Authors: Komaromi William A. , Majumdar Sharanya J. , Rappin Eric D.
Published: April 2011

The response of Weather Research and Forecasting (WRF) model predictions of two tropical cyclones to perturbations in the initial conditions is investigated. Local perturbations to the vorticity field in the synoptic environment are created in features considered subjectively to be of importance to the track forecast. The rebalanced analysis is then integrated forward and compared with an unperturbed “control” simulation possessing similar errors to those in the corresponding operational model forecasts. In the first case, Typhoon Sinlaku (2008), the premature recurvature in the control simulation is found to be corrected by a variety of initial perturbations; in particular, the weakening of an upper-level low directly to its north, and the weakening of a remote short-wave trough in the midlatitude storm track. It is suggested that one or both of the short waves may have been initialized too strongly. In the second case, the forecasts for Hurricane Ike (2008) initialized 4 days prior to its landfall in Texas were not sensitive to most remote perturbations. The primary corrections to the track of Ike arose from a weakening of a midlevel ridge directly to its north, and the strengthening of a short-wave trough in the midlatitudes. For both storms, the targets selected by the ensemble transform Kalman filter (ETKF) were often, but not always, consistent with the most sensitive regions found in this study. Overall, the results can be used to retrospectively diagnose features in which the initial conditions require improvement, in order to improve forecasts of tropical cyclone track.
Controls of Knowledge Production, Sharing and Use in Bureaucratized Professional Service Firms
Authors: Brivot Marion
Published: April 2011

One of the main obstacles to the current bureaucratization trend in large professional service firms (PSFs) is the organic nature of professional knowledge production, sharing and use. Centralized knowledge management (KM) systems aimed at codifying ‘best practice’ solutions to recurrent client questions for large-scale reuse are a common strategy increasingly employed to overcome this obstacle. Using a socio-ethnographic case study of a business law firm in Paris, this research examines whether the use of centralized KM systems in bureaucratized PSFs contributes to a shift in power from professionals to managers. More specifically, are administrative controls over knowledge resources increasing, or do professionals retain power (i.e. some level of social and self-control) over knowledge production, sharing and use? The results of this study indicate that, far from losing ground, professionals’ social and self-controls have been reinvented and reformed in a bureaucratized context.
Organizing the Circus: The Engineering of Miracles
Authors: Parker Martin
Published: April 2011

This paper defines the circus as an institutionalized questioning of forms of stability and classification, and then enquires as to how such effects are produced. I begin with the cultural representations of the circus, and then move through sections on community, movement and economic organization. This order is intended to illustrate that the production of mystery is a complex affair, and that cultural and economic descriptions of this particular form of organization are necessarily entangled. Focusing on one at the expense of the other leads to either a culturalism which lacks an understanding of production, or a business model which is incapable of understanding miracles.
Exploring and Explaining Patterns of Adaptation and Selection in Corporate Environmental Strategy in the USA
Authors: Dahlmann Frederik , Brammer Stephen
Published: April 2011

While the societal salience of environmental issues appears to have risen substantially in recent years, relatively little is known regarding how environmental responsiveness has evolved over time within business in general, or within particular private sector organizations. In this study we seek to address this deficit by exploring the evolving pattern of environmental strategy within a large sample of US companies over the period 1997 to 2006. Based on evolutionary theories of selection and adaptation as well as Burgelman’s strategic change processes, we characterize the pattern of evolving responses to natural environmental issues, distinguish between changes in the overall attention paid to environmental issues that are attributable to the forces of adaptation and selection, and examine the distinctive characteristics of those organizations that have exhibited the most dramatic improvements in their environmental strategy. Our findings indicate that while there is widespread inertia in respect of environmental responsiveness within our sample of companies, those companies that have achieved significant improvements in their environmental strategies do so as a result of a combination of autonomous and induced change processes. Such companies have often recently appointed a new CEO, are relatively strongly engaged in research and development, and have strong prior achievements in environmental strategy.
Coaching Early Childhood Special Educators to Implement a Comprehensive Model for Promoting Young Children’s Social Competence
Authors: Fox Lise , Hemmeter Mary Louise , Snyder Patricia , Binder Denise Perez , Clarke Shelley
Published: April 2011

Growing evidence suggests the importance of practitioners implementing promotion, prevention, and intervention practices to foster children’s social-emotional competence and address challenging behavior within schools. Limited research exists, however, on how to support teachers of school-age children to implement with fidelity comprehensive frameworks that organize promotion, prevention, and intervention practices, and even fewer studies have examined implementation within early childhood classrooms. In this study, three teachers were trained and coached to implement promotion, prevention, and intervention practices related to the Teaching Pyramid Model. Findings from the present single-subject multiple probe across teachers’ experimental study offer evidence of a functional relationship between training and coaching and implementation of practices associated with the model. Results are discussed with respect to challenges related to supporting teachers to implement with fidelity a complex and comprehensive array of evidence-based practices and the critical importance of coaching.
Locating Activist Spaces: The Neighbourhood as a Source and Site of Urban Activism in 1970s Calcutta
Authors: Donner Henrike
Published: April 2011

This article analyses the meaning of urban neighbourhoods for the emergence of Maoist activism in 1970s Calcutta. Through ethnography the article highlights the way recruitment, strategies and the legacy of the movement were located in the experience and politics of the urban neighbourhood. As a social formation, the neighbourhood shaped the relationships that made Maoist subjectivities feasible and provided the space for coalitions and cooperation across a wider spectrum than the label of a student movement acknowledges. The neighbourhood appears here as an emergent site for Maoist epistemologies, which depended on this space and its everyday practices, intimate social relations as well as the experience of the local state in the locality.
Ethnography and Incommensurability in the Aftermath of Insurgency
Authors: Posocco Silvia
Published: April 2011

Does ethnography in some way enact and perform what it names? If one foregrounds this performative dimension, what exactly does ethnography in the aftermath of insurgency do? The article explores these questions as they emerge in the context of ethnography in the aftermath of insurgency ( insurgencia) in Guatemala, and in relation to debates in social and cultural theory. It is argued that ethnography activates—and is responsive to—performative modes of subjectification and desubjectification discussed, inter alia, with reference to notions of ‘the archive’ and ‘testimony’. The article shows that ethnography in the aftermath of insurgency conjures up insurrectionary modalities of action. It establishes realignments and relations, enacts substitutions, and arouses modes of cross-identification between subjects, directly referencing how the insurgency was sustained during the Guatemalan conflict. However, rather than crystallizing or stabilizing an account of the insurgency, ethnography deals specifically with incommensurability and the slips— or gaps—that result from oscillations between representation—as in the multiply populated archive that holds the voices of many speaking subjects—and non-representation—as in the indexical domain of the subjectless archive that is all that there is that can speak.
Majorities with a quorum
Authors: Laruelle Annick , Valenciano Federico
Published: April 2011

Based on a general model of the ‘quaternary’ voting rule, sensitive to voters’ choices between four different options (abstaining, voting ‘yes’, voting ‘no’ and staying at home), we systematically study different types of majority and quorum. The model allows for a precise formulation of majority rules and quorum constraints. For such rules four types of majority can be defined. We also consider four types of quorum. Then we study the possible combinations of a majority system with a type of quorum and provide examples from rules actually used in parliaments.
Perceptual Expertise as a Shift From Strategic Interference to Automatic Holistic Processing
Authors: Richler Jennifer J. , Wong Yetta K. , Gauthier Isabel
Published: April 2011

Holistic processing was initially characterized as a unique hallmark of face perception but later was argued to be a marker of general perceptual expertise. More recently, evidence for holistic processing—measured by interference from task-irrelevant parts—was obtained in novices, raising questions for its usefulness as a test of expertise. Indeed, recent studies use the same task to make opposite claims: One group of researchers found more interference in novices than experts for Chinese characters, while another found more interference in experts than novices with objects. Offering a resolution to this paradox, our work on the perception of musical notation suggests that expert and novice interference effects represent two ends of a continuum: Interference is initially strategic and contextual but becomes more automatic as holistic processing develops with the acquisition of perceptual expertise.
Psychological Science and Safety
Authors: Scott Geller E.
Published: April 2011

The traditional fault-finding enforcement approach toward addressing the human dynamics of injury prevention is contrasted with behavior-based safety, which is based on applied behavior analysis. Behavior-based safety is flourishing worldwide and having measurable success, because it activates interdependent engagement of employees in identifying hazardous conditions and risky behaviors and designing interventions to reduce them, and increase the frequency of safe behaviors. People-based safety, which evolved from behavior-based safety, adds cognition (or self-talk), perception, and person states to behavior-based safety and has been developed for application in health care and industrial settings. With more widespread and long-term adoption of this application of psychological science, more injuries and fatalities from vehicle collisions, medical errors, and monumental disasters like the 2010 Deepwater Horizon oil spill will be prevented.
Collaboration Both Hurts and Helps Memory
Authors: Rajaram Suparna
Published: April 2011

Humans spend a majority of their lives in a social context. So historically, several disciplines have pursued a study of the social aspects of memory. Yet, research on memory in cognitive psychology has, for more than a century, concentrated mainly on individuals working in isolation. A recent shift in this orientation has led to a rapid growth in cognitive research revealing both counterintuitive and complex effects of collaboration on learning and remembering. For example, despite subjective reports to the contrary, collaboration impairs a group’s recall performance compared to its potential. Yet, individual group members also show improvements in recall after collaboration. This article highlights the role of cognitive mechanisms in producing these and other benefits and costs of collaboration and in shaping both individual and collective memories.
Television News Ecology in the United Kingdom
Authors: Matthews Julian , Cottle Simon
Published: April 2011

This article examines the communicative structures of UK television news presentation and how these grant characteristic shape and form to today’s mainstream television news ecology. This communicative architecture remains generally underexplored and undertheorized and yet can be demonstrated to be representationally consequential in terms of how TV news programs variously open up and elaborate, or close down and delimit, opportunities for contending views and voices as well as the cultural display of difference. Based on a systematic analysis of mainstream UK television news, the study demonstrates how today’s UK news ecology is (1) communicatively structured, (2) professionally reproduced and differentiated, and (3) representationally consequential. The communicative architecture of television news, we argue, both naturalizes and conditions the public representations of news-mediated contention and consensus, and it does so through an established repertoire of analytical and affective communicative frames.
Parametric study of a Hill-type hyperelastic skeletal muscle model
Authors: Lu Y T , Beldie L , Walker B , Richmond S , Middleton J
Published: April 2011

Hill’s one-dimensional three-element model has often been used for formulating a three-dimensional skeletal muscle constitutive model, which generally involves several material parameters. However, only few of these parameters have physical meanings and can be experimentally determined. In this paper, a parametric study of a Hill-type hyperelastic skeletal muscle model is performed. First, the Hill-type hyperelastic skeletal muscle model is formulated, containing 13 material parameters. The values or value ranges of these parameters are discussed. The muscle model is then used to predict the behaviour of New Zealand white rabbit hind leg muscle tibialis anterior and a sensitivity study of several parameters is performed. Results show that some parameters in the muscle model can be experimentally determined, some parameters have their own value ranges and the muscle model can predict the experimental data by tuning the parameters within their value ranges. The results from the sensitivity study can help understand how some parameters influence the total muscle stress.
The wear of fixed and mobile bearing unicompartmental knee replacements
Authors: Brockett C L , Jennings L M , Fisher J
Published: April 2011

Unicompartmental knee replacements (UKR) are an option for surgical intervention for the treatment of single-compartment osteoarthritis. The aim of this study was to compare the wear of a low-conformity fixed-bearing UKR with a conforming mobile bearing UKR under two kinematic conditions, to investigate the effect of implant design and kinematics on wear performance in a physiological knee wear simulator. Under both sets of kinematic conditions, the relatively low-conforming fixed UKR showed lower wear, compared with the more conforming anterior-posterior sliding mobile bearing. However, it should be noted that differences in materials between the two designs also contribute to the relative wear performance of the bearings. The combined wear of the medial and lateral bearings of the fixed-bearing UKR as a ‘total knee’ were significantly reduced compared with a fixed-bearing total knee replacement studied under the same kinematic conditions.
Priming CD8+ T cells with dendritic cells matured using TLR4 and TLR7/8 ligands together enhances generation of CD8+ T cells retaining CD28
Authors: Pufnock Jeffrey S. , Cigal Melinda , Rolczynski Lisa S. , Andersen-Nissen Erica , Wolfl Mathias , McElrath M. Juliana , Greenberg Philip D.
Published: April 2011

TLRs expressed on dendritic cells (DCs) differentially activate DCs when activated alone or in combination, inducing distinct cytokines and costimulatory molecules that influence T-cell responses. Defining the requirements of DCs to program T cells during priming to become memory rather than effector cells could enhance vaccine development. We used an in vitro system to assess the influence of DC maturation signals on priming naive human CD8+ T cells. Maturation of DCs with lipopolysaccharide (LPS; TLR4) concurrently with R848 (TLR7/8) induced a heterogeneous population of DCs that produced high levels of IL12 p70. Compared with DCs matured with LPS or R848 alone, the DC population matured with both adjuvants primed CD8+ T-cell responses containing an increased proportion of antigen-specific T cells retaining CD28 expression. Priming with a homogenous subpopulation of LPS/R848–matured DCs that were CD83Hi/CD80+/CD86+ reduced this CD28+ subpopulation and induced T cells with an effector cytokine signature, whereas priming with the less mature subpopulations of DCs resulted in minimal T-cell expansion. These results suggest that TLR4 and TLR7/8 signals together induce DCs with fully mature and less mature phenotypes that are both required to more efficiently prime CD8+ T cells with qualities associated with memory T cells.
Skeletal muscle hemojuvelin is dispensable for systemic iron homeostasis
Authors: Chen Wenjie , Huang Franklin W. , de Renshaw Tomasa Barrientos , Andrews Nancy C.
Published: April 2011

Hepcidin, a hormone produced mainly by the liver, has been shown to inhibit both intestinal iron absorption and iron release from macrophages. Hemojuvelin, a glycophosphatidyl inositol–linked membrane protein, acts as a bone morphogenetic protein coreceptor to activate hepcidin expression through a SMAD signaling pathway in hepatocytes. In the present study, we show in mice that loss of hemojuvelin specifically in the liver leads to decreased liver hepcidin production and increased tissue and serum iron levels. Although it does not have any known function outside of the liver, hemojuvelin is expressed at very high levels in cardiac and skeletal muscle. To explore possible roles for hemojuvelin in skeletal muscle, we analyzed conditional knockout mice that lack muscle hemojuvelin. The mutant animals had no apparent phenotypic abnormalities. We found that systemic iron homeostasis and liver hepcidin expression were not affected by loss of hemojuvelin in skeletal muscle regardless of dietary iron content. We conclude that, in spite of its expression pattern, hemojuvelin is primarily important in the liver.
Women in post-trafficking services in moldova: diagnostic interviews over two time periods to assess returning women's mental health
Authors: Ostrovschi Nicolae V , Prince Martin J , Zimmerman Cathy , Hotineanu Mihai A , Gorceag Lilia T , Gorceag Viorel I , Flach Clare , Abas Melanie A
Published: April 2011

Background

Trafficking in women is a widespread human rights violation commonly associated with poor mental health. Yet, to date, no studies have used psychiatric diagnostic assessment to identify common forms of mental distress among survivors returning to their home country.

Methods

A longitudinal study was conducted of women aged 18 and over who returned to Moldova between December 2007 and December 2008 registered by the International Organisation for Migration as a survivor of human trafficking. Psychiatric diagnoses in women at a mean of 6 months after return (range 2-12 months) were made by a trained Moldavian psychiatrist using the Structured Clinical Interview for DSM-IV, and compared with diagnoses recorded in the same women within 5 days of return. We described the socio-demographic characteristics of the women in the sample including both pre and post-trafficking information. We then described the distribution of mental health diagnoses recorded during the crisis intervention phase (1-5 days after return) and the re-integration phase (2-12 months after return). We compared diagnoses at the patient level between the two time points by tabulating the diagnoses and carrying out a kappa test of agreement and the Stuart-Maxwell test for marginal homogeneity (an extension of the McNemar test to kxk table).

Results

120/176 (68%) eligible women participated. At 2-12 months after their return, 54% met criteria for at least one psychiatric diagnoses comprising post-traumatic stress disorder (PTSD) alone (16%); co-morbid PTSD (20%); other anxiety or mood disorder (18%). 85% of women who had been diagnosed in the crisis phase with co-morbid PTSD or with another anxiety or mood disorder sustained a diagnosis of any psychiatric disorder when followed up during rehabilitation.

Conclusions

Trafficked women returning to their country of origin are likely to suffer serious psychological distress that may endure well beyond the time they return. Women found to have co-morbid PTSD or other forms of anxiety and depression immediately post-return should be offered evidenced-based mental health treatment for at least the standard 12-month period of rehabilitation.