bluuebunny/crossref_metadata_2025 huggingface dataset:
Distributed biochar and bioenergy coproduction: a regionally specific case study of environmental benefits and economic impacts
Authors: Field John L. , Keske Catherine M. H. , Birch Greta L. , DeFoort Morgan W. , Cotrufo M. Francesca
Published: January 2013

Biochar has been advocated as a method of sequestering carbon while simultaneously improving crop yields and agro‐ecosystem sustainability. It can be produced from a wide variety of biomass feedstocks using different thermochemical conversion technologies with or without the recovery of energy coproducts, resulting in chars of differing quality and a range of overall system greenhouse gas (GHG) mitigation outcomes. This analysis expands on previous sustainability studies by proposing a mechanistic life cycle GHG and economic operating cost assessment model for the coproduction of biochar and bioenergy from biomass residue feedstocks, with a case study for north‐central Colorado presented. Production is modeled as a continuous function of temperature for slow pyrolysis, fast pyrolysis, and gasification systems. Biochar environmental benefits (C sequestration, N2O suppression, crop yield improvements) are predicted in terms of expected liming value and recalcitrance. System‐level net GHG mitigation is computed, and net returns are estimated that reflect the variable economic costs of production, the agronomic value of biochar based on agricultural limestone or fertilizer displacement, and the value of GHG mitigation, with results compared to the alternate use of char for energy production. Case study results indicate that slow pyrolysis systems can mitigate up to 1.4 Mg CO2eq/Mg feedstock consumed, provided a favorable feedstock is utilized, production air pollutant emissions are mitigated, and energy coproducts are recovered. The model suggests that while financial returns are generally greater when char is consumed for energy (biocoal) than when used as a soil amendment (biochar), chars produced through high‐temperature conversion processes will have greater GHG‐mitigation value as biochar. The biochar scenario reaches economic parity at carbon prices as low as $50/Mg CO2eq for optimal scenarios, despite conservative modeling assumptions. This model is a step toward spatially explicit assessment and optimization of biochar system design across different feedstocks, conversion technologies, and agricultural soils.
Simulating the effects of harvest and biofuel production on the forest system carbon balance of the Midwest, USA
Authors: Peckham Scott D. , Gower Stith T.
Published: January 2013

Forests of the Midwestern United States are an important source of fiber for the wood and paper products industries. Scientists, land managers, and policy makers are interested in using woody biomass and/or harvest residue for biofuel feedstocks. However, the effects of increased biomass removal for biofuel production on forest production and forest system carbon balance remain uncertain. We modeled the carbon (C) cycle of the forest system by dividing it into two distinct components: (1) biological (net ecosystem production, net primary production, autotrophic and heterotrophic respiration, vegetation, and soil C content) and (2) industrial (harvest operations and transportation, production, use, and disposal of major wood products including biofuel and associated C emissions). We modeled available woody biomass feedstock and whole‐system carbon balance of 220 000 km2 of temperate forests in the Upper Midwest, USA by coupling an ecosystem process model to a collection of greenhouse gas life‐cycle inventory models and simulating seven forest harvest scenarios in the biological ecosystem and three biofuel production scenarios in the industrial system for 50 years. The forest system was a carbon sink (118 g C m−2 yr−1) under current management practices and forest product production rates. However, the system became a C source when harvest area was doubled and biofuel production replaced traditional forest products. Total carbon stores in the vegetation and soil increased by 5–10% under low‐intensity management scenarios and current management, but decreased up to 3% under high‐intensity harvest regimes. Increasing harvest residue removal during harvest had more modest effects on forest system C balance and total biomass removal than increasing the rate of clear‐cut harvests or area harvested. Net forest system C balance was significantly, and negatively correlated (R2 = 0.67) with biomass harvested, illustrating the trade‐offs between increased C uptake by forests and utilization of woody biomass for biofuel feedstock.
The incentive gap: LULUCF and the Kyoto mechanism before and after Durban
Authors: Ellison David , Petersson Hans , Lundblad Mattias , Wikberg Per‐Erik
Published: January 2013

To‐date, forest resource‐based carbon accounting in land use, land use change and forestry (LULUCF) under the United Nations Framework Convention on Climate Change (UNFCCC), Kyoto Protocol (KP), European Union (EU) and national level emission reduction schemes considers only a fraction of its potential and fails to adequately mobilize the LULUCF sector for the successful stabilization of atmospheric greenhouse gas (GHG) concentrations. Recent modifications at the 2011 COP17 meetings in Durban have partially addressed this basic problem, but leave room for improvement. The presence of an Incentive Gap (IG) continues to justify reform of the LULUCF carbon accounting framework. Frequently neglected in the climate change mitigation and adaptation literature, carbon accounting practices ultimately define the nuts and bolts of what counts and which resources (forest, forest‐based or other) are favored and utilized. For Annex I countries in the Kyoto Mechanism, the Incentive Gap under forest management (FM) is significantly large: some 75% or more of potential forestry‐based carbon sequestration is not effectively incentivized or mobilized for climate change mitigation and adaptation (Ellison et al. 2011a). In this paper, we expand our analysis of the Incentive Gap to incorporate the changes agreed in Durban and encompass both a wider set of countries and a larger set of omitted carbon pools. For Annex I countries, based on the first 2 years of experience in the first Commitment Period (CP1) we estimate the IG in FM at approximately 88%. Though significantly reduced in CP2, the IG remains a problem. Thus our measure of missed opportunities under the Kyoto and UNFCCC framework – despite the changes in Durban – remains important. With the exception perhaps of increased energy efficiency, few sinks or sources of reduced emissions can be mobilized as effectively and efficiently as forests. Thus, we wonder at the sheer magnitude of this underutilized resource.
A method for screening the relative long‐term stability of biochar
Authors: Cross Andrew , Sohi Saran P.
Published: January 2013

Biochar is being actively explored as a tool for long‐term soil carbon sequestration. However, in order for this to be effective the long‐term environmental stability of biochar must be assured. Here, we define and test an accelerated ageing method that seeks to reflect the oxidative nature of biochar degradation in soil. The method was applied to a systematic set of biochar samples produced from sugarcane bagasse, and a set of biochar samples produced from four different biomass sources. The stability of carbon in these samples was found to range between 41.6% and 76.1%, loosely correlating with biochar O : C ratio (r = 0.73). Increasing intensity of oxidative treatment eliminated more carbon. It also increased surface O : C ratio in a manner reported for naturally aged charcoal samples. The method effectively discriminated biochar produced under contrasting pyrolysis conditions and could be used as a proxy for environmental ageing of approximately 100 years under temperate conditions.
Biochar and its effects on plant productivity and nutrient cycling: a meta‐analysis
Authors: Biederman Lori A. , Harpole W. Stanley
Published: January 2013

Biochar is a carbon‐rich coproduct resulting from pyrolyzing biomass. When applied to the soil it resists decomposition, effectively sequestering the applied carbon and mitigating anthropogenicCO2emissions. Other promoted benefits of biochar application to soil include increased plant productivity and reduced nutrient leaching. However, the effects of biochar are variable and it remains unclear if recent enthusiasm can be justified. We evaluate ecosystem responses to biochar application with a meta‐analysis of 371 independent studies culled from 114 published manuscripts. We find that despite variability introduced by soil and climate, the addition of biochar to soils resulted, on average, in increased aboveground productivity, crop yield, soil microbial biomass, rhizobia nodulation, plant K tissue concentration, soil phosphorus (P), soil potassium (K), total soil nitrogen (N), and total soil carbon (C) compared with control conditions. SoilpHalso tended to increase, becoming less acidic, following the addition of biochar. Variables that showed no significant mean response to biochar included belowground productivity, the ratio of aboveground : belowground biomass, mycorrhizal colonization of roots, plant tissue N, and soil P concentration, and soil inorganic N. Additional analyses found no detectable relationship between the amount of biochar added and aboveground productivity. Our results provide the first quantitative review of the effects of biochar on multiple ecosystem functions and the central tendencies suggest that biochar holds promise in being a win‐win‐win solution to energy, carbon storage, and ecosystem function. However, biochar's impacts on a fourth component, the downstream nontarget environments, remain unknown and present a critical research gap.
Aboveground productivity and soil carbon storage of biofuel crops in Ohio
Authors: Bonin Catherine L. , Lal Rattan
Published: January 2013

Biofuel crops may help achieve the goals of energy‐efficient renewable ethanol production and greenhouse gas (GHG) mitigation through carbon (C) storage. The objective of this study was to compare the aboveground biomass yields and soil organic C (SOC) stocks under four crops (no‐till corn, switchgrass, indiangrass, and willow) 7 years since establishment at three sites in Ohio to determine if high‐yielding biofuel crops are also capable of high levels of C storage. Corn grain had the highest potential ethanol yields, with an average of more than 4100 L ha−1, and ethanol yields increased if both corn grain and stover were converted to biofuel, while willow had the lowest yields. The SOC concentration in soils under biofuels was generally unaffected by crop type; at one site, soil in the top 10 cm under willow contained nearly 13 Mg C ha−1 more SOC (or 29% more) than did soils under switchgrass or corn. Crop type affected SOC content of macroaggregates in the top 10 cm of soil, where macroaggregates in soil under corn had lower C, N and C : N ratios than those under perennial grasses or trees. Overall, the results suggest that no‐till corn is capable of high ethanol yields and equivalent SOC stocks to 40 cm depth. Long‐term monitoring and measurement of SOC stocks at depth are required to determine whether this trend remains. In addition, ecological, energy, and GHG assessments should be made to estimate the C footprint of each feedstock.
Negotiating Education Reform: Teacher Evaluations and Incentives in Chile (1990–2010)
Authors: Mizala Alejandra , Schneider Ben Ross
Published: January 2013

Reforms designed to improve the quality of teaching by reforming personnel practices, such as pay for performance arrangements, usually run into opposition from well‐organized teacher unions that can either block reform in the short run or undermine it over the longer term. The experience of a series of reforms that introduced collective and individual pay incentives for teachers in Chile from 1990 to 2010 provide a rare example of ongoing negotiation with the teacher union that resulted in an institutionalized structure of incentive pay for teachers as well as widespread attitudes of sustained support among teachers for performance pay. Chile offers an important example of how sustained change in incentive pay can be achieved through ongoing negotiation.
When Does Transparency Generate Legitimacy? Experimenting on a Context‐Bound Relationship
Authors: De Fine Licht Jenny , Naurin Daniel , Esaiasson Peter , Gilljam Mikael
Published: January 2013

We analyze the main rationale for public administrations and political institutions for supplying transparency, namely, that it generates legitimacy for these institutions. First, we discuss different theories of decision making from which plausible causal mechanisms that may drive a link between transparency and legitimacy may be derived. We find that the common notion of a straightforward positive correlation is naïve and that transparency reforms are rather unpredictable phenomena. Second, we test the effect of transparency on procedure acceptance using vignette experiments of representative decision making in schools. We find that transparency can indeed generate legitimacy. Interestingly, however, the form need not be “fishbowl transparency,” with full openness of the decision‐making process. Decision makers may improve their legitimacy simply by justifying carefully afterward the decisions taken behind closed doors. Only when behavior close to a deliberative democratic ideal was displayed did openness of the process generate more legitimacy than closed‐door decision making with postdecisional justifications.
Molecular characterization and immunolocalization of the olfactory co‐receptor Orco from two blood‐feeding muscid flies, the stable fly (Stomoxys calcitrans, L.) and the horn fly (Haematobia irritans irritans, L.)
Authors: Olafson P. U.
Published: January 2013

Biting flies are economically important blood‐feeding pests of medical and veterinary significance. Chemosensory‐based biting fly behaviours, such as host/nutrient source localization and ovipositional site selection, are intriguing targets for the development of supplemental control strategies. In an effort to expand our understanding of biting fly chemosensory pathways, transcripts encoding the highly conserved insect odorant co‐receptor (Orco) were isolated from two representative biting fly species, the stable fly (Scal\Orco) and the horn fly (Hirr\Orco). Orco forms a complex with an odour‐specific odorant receptor to form an odour‐gated ion channel. The biting fly transcripts were predicted to encode proteins with 87–94% amino acid similarity to published insect Orco sequences and were detected in various immature stages as well as in adult structures associated with olfaction, i.e. the antennae and maxillary palps, and gustation, i.e. the proboscis. Further, the relevant proteins were immunolocalized to specific antennal sensilla using anti‐serum raised against a peptide sequence conserved between the two fly species. Results from the present study provide a basis for functional evaluation of repellent/attractant effects on as yet uncharacterized stable fly and horn fly conventional odorant receptors.
Phosphorothioate‐modified CpG oligodeoxynucleotides mimic autoantigens and reveal a potential role for Toll‐like receptor 9 in receptor revision
Authors: Doster Anne , Ziegler Saskia , Foermer Sandra , Rieker Ralf Joachim , Heeg Klaus , Bekeredjian‐Ding Isabelle
Published: January 2013

Re‐expression of recombinase activating genes (RAG) in mature B cells may support autoreactivity by enabling revision of the B‐cell receptor (BCR). Recent reports suggest that administration of Toll‐like receptor 9 (TLR9) ‐stimulating CpG oligodeoxynucleotides (ODN) could trigger the manifestation of autoimmune disease and that TLR are involved in the selection processes eliminating autoreactive BCR. The mechanisms involved remain to be elucidated. This prompted us to ask, whether TLR9 could be involved in receptor revision. We found that phosphorothioate‐modified CpG ODN (CpGPTO) induced expression of Ku70 and re‐expression of RAG‐1 in human peripheral blood B lymphocytes and Igλ expression in sorted Igκ+ B cells. Further results revealed unselective binding specificity of CpGPTO‐induced immunoglobulin and suggested that CpGPTO engage and/or mimic IgM receptor signalling, an important prerequisite for the initialization of receptor editing or revision. Altogether, our data describe a potential role for TLR9 in receptor revision and suggest that CpGPTO could mimic chromatin‐bearing autoantigens by simultaneously engaging the BCR and TLR9 on IgM+ B cells.
An Approach to Dynamic Classification of Traffic Flow Patterns
Authors: Celikoglu Hilmi Berk
Published: January 2013

Abstract:  Analyses on the dynamics of traffic flow, ranging from intersection flows to network‐wide flow propagation, require accurate information on time‐varying local traffic flows. To effectively determine the flow performance measures and consequently the congestion indicators of segmented road pieces, the ability to process such data in real time is out of the question. In this article, a dynamic approach to specify flow pattern variations is proposed mainly concentrating on the incorporation of neural network theory to provide real‐time mapping for traffic density simultaneously in conjunction with a macroscopic traffic flow model. To deal with the noise and the wide scatter of raw flow measures, a filtering is applied prior to modeling processes. Filtered data are dynamically and simultaneously input to processes of neural density mapping and traffic flow modeling. The classification of flow patterns over the fundamental diagram, which is dynamically plotted with the outputs of the flow modeling subprocess, is obtained by considering the density measure as a pattern indicator. Densities are mapped by selected neural approximation method for each simulation time step considering explicitly the flow conservation principle. Simultaneously, mapped densities are matched over the fundamental diagram to specify the current corresponding flow pattern. The approach is promising in capturing sudden changes on flow patterns and is open to be utilized within a series of intelligent management strategies including especially nonrecurrent congestion effect detection and control.
An Exploration of the Perceptions of Male Partners Involved in the Birthing Experience at a Regional Australian Hospital
Authors: Porrett Liesel , Barkla Sally , Knights Janice , de Costa Caroline , Harmen Sonia
Published: January 2013

Introduction: The benefits to women of having their male partners present during labor and birth have been well documented, but the effects on men of sharing the birth experience have been less well explored. Several studies have suggested that male partners’ positive experiences at this time may benefit partner and family relationships subsequently, whereas negative experiences may translate into later difficulties in these relationships. This study explored the perceptions of male partners involved in the birthing experience in the Integrated Women's Health Unit of Cairns Base Hospital, Cairns, Australia, over a 6‐month period in 2010. The aims of the study were to document male partners’ self‐reported perceptions of their antenatal, labor, and birth experiences and birth expectations and birth involvement and to determine whether these perceptions influenced their feelings that their presence during birth was beneficial to the birthing woman.

Methods: Participants were men experiencing for the first time their partner giving birth. A self‐administered 14‐item questionnaire was used to collect data; 163 of 200 eligible participants returned completed questionnaires. Continuous variables were converted to categorical variables and chi‐square testing was used to determine significant differences between groups. The relationship between beneficial presence and antenatal, labor, and birthing experiences was assessed using correlation analysis and hierarchical regression analysis.

Results: There was a significant relationship demonstrated between perceived benefit of the partners’ presence and positive perception of both antenatal experience and birth involvement. There also was a positive relationship between realized birth expectations and both antenatal experience and birth involvement.

Discussion: This study suggests that male partners’ perceptions of beneficial presence during the birth experience can be enhanced by their feeling well informed and supported during the antenatal period and feeling involved and supported by staff during birth. These findings have implications for the provision of information and support to male partners by midwives and childbirth educators and provide the basis for further research in this area.
Ecological links between salmon, large carnivore predation, and scavenging birds
Authors: Field Rachel D. , Reynolds John D.
Published: January 2013

We compared scavenging bird abundance and diversity across 17 estuaries on the Central Coast of British Columbia, Canada in relation to landscape characteristics and biomass of spawning salmon and senescent and depredated salmon carcasses. We discovered that all metrics for spawning salmon and carcass biomasses were strong predictors of scavenger abundance and diversity. Specifically, Shannon’s diversity, which emphasizes rare species richness, and total abundances of scavengers, corvids (Corvus spp.), and small and large gulls (Larus spp.) were most strongly predicted by total biomass of carcasses. In contrast, the abundance of bald eagles Haliaeetus leucocephalus was most strongly predicted by biomass of carcasses that had been killed or scavenged by other predators (mostly bears and wolves). Simpson’s diversity, which emphasizes evenness of common species, was best predicted by total spawning salmon biomass. Estuary area also featured prominently among top predictors of most scavenger metrics. Our results suggest a link between terrestrial salmon predators and bald eagles, and that available salmon biomass is important for maintaining the abundance and diversity of scavenging birds that congregate at estuaries throughout the spawning season.
Geographic variation and the evolution of song in Mesoamerican rufous‐naped wrensCampylorhynchus rufinucha
Authors: Sosa‐López J. Roberto , Mennill Daniel J. , Navarro‐Sigüenza Adolfo G.
Published: January 2013

Speciation may be influenced by geographic variation in animal signals, particularly when those signals are important in reproductive decisions. Here, we describe patterns of geographic variation in the song of rufous‐naped wrens Campylorhynchus rufinucha. This species complex is a morphologically variable taxon confined to tropical dry forest areas from Mexico to northwestern Costa Rica. Morphological and genetic analyses suggest that there are at least three partially isolated groups within the complex, including a secondary‐contact zone in coastal western Chiapas between the subspeciesC. r. humilusandC. r. nigricaudatus. Based on recordings throughout their geographic range, we investigate the effects of historical isolation on song structure and analyze whether genetic differences or climatic conditions explain observed patterns of variation. Our findings, based on a culturally‐transmitted and sexually‐selected trait, support the hypothesis that three evolutionary units exist within this taxon. Our results suggest that song differences between genetic groups were influenced by historical isolation. We report a strong relationship between vocal dissimilarity and genetic distance, suggesting that differences in vocal characteristics are probably affected by the same factors that drive genetic divergence. We argue that the evolution of song in this taxon is influenced by vicariant events, followed by accumulation of changes in song structure due to several possible factors: cultural drift in song structure; genetic drift in features related to song production; or natural selection acting on features that influence songs, such as body and beak size.
Age‐dependent relationships between coloration and reproduction in a species exhibiting delayed plumage maturation in females
Authors: Bentz Alexandra B. , Siefferman Lynn
Published: January 2013

Males of many bird species exhibit delayed plumage maturation (DPM), a condition in which young individuals display an immature plumage. Several adaptive hypotheses have been suggested for the signaling utility of DPM in males. Tree swallows Tachycineta bicolor, however, are one of the few bird species to exhibit DPM in females, but not in males. Few studies have focused on the age‐dependent signaling function of female plumage traits due to the uncommon nature of DPM in females. Therefore, we used reflectance spectrometry and scanning electron microscopy of sub‐adult (melanin‐based brown) and adult (iridescent‐blue structural) female tree swallows to characterize plumage coloration. Next, we asked whether variation in plumage coloration in females reflects condition and reproductive performance between and within age classes. We found that older females were in better body condition and laid eggs earlier in the season compared to young females; however, average egg mass and reproductive success (number of offspring fledged and offspring condition) did not differ between age classes. There were significant relationships indicating that young females with more‐ornamented (darker brown melanin) plumage laid smaller eggs, but hatched eggs earlier in the season leading to nestlings in better condition compared to less‐ornamented young females. Older females that were more ornamented (brighter, greater blue chroma, and lower hues in iridescent plumage) laid heavier eggs, but ornamentation was negatively associated with immune function, health, and reproductive success. Together, these data suggest that female ornamentation reflects reproductive performance and that there are complicated relationships between plumage coloration, condition, and reproductive performance that ultimately influence reproductive success.
Preparation and Characterisation of Two Geochemical Reference Materials: DG‐H (Granite) and AM‐H (Amphibolite) from the Himalayan Orogenic Belt
Authors: Saini Naresh K. , Khanna Param P. , Mukherjee Pulok K. , Purohit Kishor K.
Published: January 2013

Two geochemical reference materials of Himalayan origin named DG‐H (a granite) and AM‐H (an amphibolite) prepared by the Wadia Institute of Himalayan Geology Dehradun are described. Both samples were collected from the NW Himachal Himalaya in India. With the participation of analysts from more than forty international laboratories, element determination data collected during the past 10 years for characterisation of the samples was processed to assign working values using statistical procedures in use for this purpose. Earlier work published on these samples is incorporated in the present communication making it an updated document. The typical chemical and petrological characteristics of these two samples may prove useful for method validation and calibration of analytical instruments used for analysing similar rock types, and for widening the analytical range of several analytical methods used for geochemical analysis.
The Psychological Impact of Abuse on Men and Women with Severe Intellectual Disabilities
Authors: Rowsell A. C. , Clare I. C. H. , Murphy G. H.
Published: January 2013

Background

In other populations, the psychological impact of abuse has been conceptualized as Post Traumatic Stress Disorder (PTSD, DSM‐IV, American Psychiatric Association (APA), 1994), but little is known about whether this is appropriate for adults with severe intellectual disabilities and very limited communication skills.

Methods

An informant interview, based on the framework provided by PTSD, but supplemented with additional questions, was developed and was used to elicit the emotional, behavioural and physiological symptoms of alleged abuse in 18 people with intellectual disabilities at three time points: in the 3 months immediately prior to the alleged abuse (Time 1), in the 3 months immediately after the abuse (Time 2) and in the last 3 months prior to interview (Time 3).

Results

The reports of the family and carer informants indicated that, following their alleged abuse, the victims experienced marked increases in the frequency and severity of emotional, physiological and behavioural symptoms of psychological distress. Over time, there was some alleviation of these difficulties, but psychological functioning remained severely compromised.

Conclusions

While the established PTSD framework is appropriate for examining the psychological impact of abuse, some amendments are required to enable clinicians to examine fully the distress of alleged victims with severe intellectual disabilities.
Aborted Sudden Cardiac Death Due to Radiofrequency Ablation Within the Coronary Sinus and Subsequent Total Occlusion of the Circumflex Artery
Authors: MAKIMOTO HISAKI , ZHANG QINGYONG , TILZ ROLAND RICHARD , WISSNER ERIK , CUNEO ALESSANDRO , KUCK KARL‐HEINZ , OUYANG FEIFAN
Published: January 2013

Aborted Cardiac Death After Ablation of Coronary Sinus

We report a case of aborted sudden cardiac death and subsequent development of malignant drug‐refractory incessant ventricular tachycardia/fibrillation in a patient with acute coronary artery occlusion following radiofrequency ablation within the CS. Catheter ablation is a well‐established therapy for treatment of atrial fibrillation (AF). In patients with longstanding persistent AF extensive left atrial ablation and ablation inside the coronary sinus (CS) is frequently performed. Perimitral flutter following AF ablation is the most common form of left atrial macroreentry, especially in patients with previous ablation of complex fractionated electrograms and incomplete linear lesion sets within the left atrium. Successful ablation of this type of tachycardia is generally difficult and in about 60–70% patients requires additional ablation within the CS to achieve termination of tachycardia or/and left atrial isthmus (LAI) block. A limited number of case reports have been published describing acute coronary artery occlusion during or immediately after LAI ablation within the CS. This case exhibits a potential lethal risk of radiofrequency ablation within the CS.
Correlation Between Total Atrial Conduction Time Estimated via Tissue Doppler Imaging (PA‐TDI Interval), Structural Atrial Remodeling and New‐Onset of Atrial Fibrillation After Cardiac Surgery
Authors: MÜLLER PATRICK , HARS CHRISTINE , SCHIEDAT FABIAN , BÖSCHE LEIF I. , GOTZMANN MICHAEL , STRAUCH JUSTUS , DIETRICH J.W. , VOGT MARKUS , TANNAPFEL ANDREA , DENEKE THOMAS , MÜGGE ANDREAS , EWERS AYDAN
Published: January 2013

Atrial Conduction Time

Background

Recent studies identified total atrial conduction time (TACT) as an independent and powerful predictor of new‐onset atrial fibrillation (AF). The purpose of this study was to assess the association between the degree of atrial fibrosis, TACT, and frequency of postoperative atrial fibrillation (POAF) among patients undergoing cardiac surgery.

Methods and Results

Sixty patients in sinus rhythm (mean ± SD age 66 ± 10 years; 22% women) and without a history of AF undergoing cardiac surgery were prospectively enrolled. TACT was measured preoperatively in the left atrium by tissue‐Doppler Imaging (PA‐TDI interval). Holter‐ECG/telemetry was used to screen for POAF throughout 10 days after cardiac surgery. Right atrial appendages (RAA) were obtained in 33 patients during surgery; atrial fibrosis was assessed by visual quantification (% area of positive van Gieson elastic staining). POAF occurred in 23 patients (38%). Fibrosis extent of RAA was higher in patients with POAF as compared to those without (27.5 ± 1.93 vs 15.8 ± 0.81% area; mean ± SEM; P < 0.001). PA‐TDI interval was longer in patients with POAF versus patients who maintained in sinus rhythm (152.1 ± 3.0 vs 120.8 ± 1.8 milliseconds; P < 0.001) and correlated with the degree of atrial fibrosis (r = 0.73; P < 0.01). At the cut‐off value of 133 milliseconds, TACT sensitivity and specificity related to POAF were 100% and 86%, respectively.

Conclusion

PA‐TDI interval is useful to identify patients at risk for POAF undergoing cardiac surgery and correlates with the degree of atrial fibrosis.
Double Cryoenergy Application (Freeze‐Thaw‐Freeze) at Growing Myocardium: Lesion Volume and Effects on Coronary Arteries Early After Energy Application. Implications for Efficacy and Safety in Pediatric Patients
Authors: SCHNEIDER HEIKE E. , STAHL MAJA , KRIEBEL THOMAS , SCHILLINGER WOLFGANG , SCHILL MANFRED , JAKOBI JOHANNES , PAUL THOMAS
Published: January 2013

Modified Cryoenergy at Growing Myocardium

Introduction

Data on radiofrequency current application (RFA) at growing myocardium suggest that coronary artery stenosis may occur with a low incidence. Cryoenergy has emerged as an effective alternative to RFA. Although already used in clinical practice, experience with cryoenergy is low due to lack of data concerning effects of a modified double cryoenergy application, a freeze‐thaw‐freeze cycle, at growing myocardium. Purpose of the study was to assess lesion volume (efficacy) and risk of coronary artery damage (safety) early, 48 hours, after modified double cryoenergy application in a piglet model.

Methods and Results

In 5 piglets, following selective coronary angiography, two sequential cycles of cryoenergy were delivered at −75 °C for 4 minutes, interrupted by thawing for one minute, at the atrioventricular groove. Piglets were restudied after 48 hours by coronary angiography and intracoronary ultrasound (ICUS). Ablation lesions were examined morphologically and lesion volume was determined by 3‐dimensional morphometric analysis.

Lesion volume was 109.21 ± 39.61 mm3 for atrial and 150.30 ± 53.21 mm3 (P = 0.02) for ventricular lesions. Lesion depth was not significantly different for atrial, 3.07 ± 1.08 mm, versus ventricular lesions, 3.56 ± 1.3 mm. Cryoenergy induced minor coronary artery damage with medial and adventitial necrosis but a preserved intimal layer was present in 2/31 lesions, which had not been detected by coronary angiography or ICUS.

Conclusion

Early after double cryoenergy application, subclinical minor changes of the coronary artery wall could be detected occasionally whereas the intimal layer remained intact. These findings may have implications on efficacy and safety when cryoenergy is applied for tachycardia substrates in pediatric patients.
Intima‐media thickness in an Italian psoriatic population: correlation with lipidic serum levels, PASI and BMI
Authors: Antonucci V.A. , Tengattini V. , Balestri R. , Patrizi A. , Filippini M. , Bardazzi F.
Published: January 2013

Background  Recent findings have shown that psoriasis is frequently associated with atherosclerosis. Intima‐media thickness (IMT) is a surrogate marker of atherosclerosis damage. Psoriasis patients had impaired endothelial function and thicker IMT of the carotid artery, compared with the healthy control subjects.

Objectives  The aim of our study is to evaluate the prevalence of subclinical atherosclerosis in patients affected by cutaneous psoriasis without arthritis, considering the IMT as a subclinical feature of atherosclerosis.

Methods  Intima‐media thickness of the common carotid artery was measured using High‐resolution B‐mode ultrasound in 40 psoriasis patients and 40 control patients matched for age and gender. We also measured triglycerides, PASI, total cholesterol, LDL cholesterol and BMI. Pearson’s partial correlation test was used to determine the correlation between each variable.

Results  Intima‐media thickness in subjects with psoriasis was statistically higher than those in the control subjects (1.465 mm, P value < 0.001). A positive strong correlation between IMT and age (r = 0.464 P < 0.01), total cholesterol (r = 0.466 P < 0.01), LDL cholesterol (r = 0.518 P < 0.01), triglycerides (r = 0.285 P = 0.01) and PASI (r = 0.515 P < 0.01) was observed. There was no statistically significant correlation between IMT and BMI (r = 0.132 P = 0.244).

Conclusions  Our study showed a significant increase in IMT in cutaneous psoriatic patients with moderate to severe psoriasis compared with a control group. IMT seems to be uncorrelated with BMI value. It can be assumed that the assessment of IMT, through a reliable and non‐invasive technique such as ultrasound, appears particularly useful in the clinical evaluation of patients with psoriasis who may benefit from early intervention.
The double burden of obesity and iron deficiency on children and adolescents in Greece: the Healthy Growth Study
Authors: Manios Y. , Moschonis G. , Chrousos G. P. , Lionis C. , Mougios V. , Kantilafti M. , Tzotzola V. , Skenderi K. P. , Petridou A. , Tsalis G. , Sakellaropoulou A. , Skouli G. , Katsarou C.
Published: January 2013

Background

Some small cohort studies have noted that obesity co‐exists with lower serum iron levels. The present study aimed to examine the association between being overweight and iron deficiency (ID) in a large cohort of Greek children and adolescents.

Methods

A representative sample of 2492 primary schoolchildren aged 9–13 years old was examined. Anthropometric, biochemical, clinical, dietary intake and physical activity data were collected.

Results

The prevalence of ID and iron deficiency anaemia (IDA) was higher in obese boys and girls compared to their normal‐weight peers (P < 0.05). Serum ferritin was higher in obese compared to normal‐weight boys (P = 0.024) and higher in obese compared to normal‐weight and overweight girls (P = 0.001). By contrast, a negative association was found between transferrin saturation and adiposity in both boys and girls (P = 0.001 and P = 0.005). Furthermore, obese girls had significantly higher fibre intake than normal‐weight girls (P = 0.048) and also overweight and obese boys and girls recorded significantly fewer pedometer steps than their normal‐weight peers (P < 0.001). Finally, obesity more than doubled the likelihood of ID in both boys (odds ratio = 2.83; 95% confidence inteval = 1.65–4.85) and girls (odds ratio = 2.03; 95% confidence interval = 1.08–3.81) after controlling for certain lifestyle and clinical indices as potential confounders.

Conclusions

The present study shows that obese children and adolescents were at greater risk for ID and IDA than their normal‐weight peers. Low grade inflammation induced by excessive adiposity may be a reason for the observed low iron levels. This is also strengthened by the elevated serum ferritin levels, comprising an acute phase protein that is plausibly increased in inflammation.
Neuron‐type specific cannabinoid‐mediated G protein signalling in mouse hippocampus
Authors: Steindel Frauke , Lerner Raissa , Häring Martin , Ruehle Sabine , Marsicano Giovanni , Lutz Beat , Monory Krisztina
Published: January 2013

Type 1 cannabinoid receptor (CB1) is expressed in different neuronal populations in the mammalian brain. In particular, CB1 on GABAergic or glutamatergic neurons exerts different functions and display different pharmacological properties in vivo. This suggests the existence of neuron‐type specific signalling pathways activated by different subpopulations of CB1. In this study, we analysed CB1 expression, binding and signalling in the hippocampus of conditional mutant mice, bearing CB1 deletion in GABAergic (GABA‐CB1‐KO mice) or cortical glutamatergic neurons (Glu‐CB1‐KO mice). Compared to their wild‐type littermates, Glu‐CB1‐KO displayed a small decrease of CB1 mRNA amount, immunoreactivity and [³H]CP55,940 binding. Conversely, GABA‐CB1‐KO mice showed a drastic reduction of these parameters, confirming that CB1 is present at much higher density on hippocampal GABAergic interneurons than glutamatergic neurons. Surprisingly, however, saturation analysis of HU210‐stimulated [35S]GTPγS binding demonstrated that ‘glutamatergic’ CB1 is more efficiently coupled to G protein signalling than ‘GABAergic’ CB1. Thus, the minority of CB1 on glutamatergic neurons is paradoxically several fold more strongly coupled to G protein signalling than ‘GABAergic’ CB1. This selective signalling mechanism raises the possibility of designing novel cannabinoid ligands that differentially activate only a subset of physiological effects of CB1 stimulation, thereby optimizing therapeutic action.
Aortic Valve Stenosis: To the Gradient and Beyond—The Mismatch Between Area and Gradient Severity
Authors: ABBAS AMR E. , FRANEY LAURA M. , GOLDSTEIN JAMES , LESTER STEVEN
Published: January 2013

Objectives

The clinical severity of aortic stenosis (AS) is based largely on symptoms. However, AS severity is primarily determined by estimating the aortic valve area (AVA) and pressure gradients (ΔP). Conditions may arise in which there is a mismatch in severity between AVA and ΔP determinations secondary to errors in measurement and/or assumption, alterations of flow, or variations in the magnitude of pressure recovery. The cause of discrepancy between area and gradient determinations must be deciphered so as to best counsel patients on the most ideal treatment strategy. (J Interven Cardiol 2013;26:183–194)
A Pilot Study of Prasugrel Followed by Post‐Procedural Maintenance with Clopidogrel in Patients Receiving Percutaneous Coronary Intervention
Authors: BENJAMIN MINA M. , FILARDO GIOVANNI , DONSKY MICHAEL S. , SCHUSSLER JEFFREY M.
Published: January 2013

Background

Dual anti‐platelet therapy including clopidogrel or prasugrel is standard of care for patients receiving stents. Prasugrel has quicker onset so it can be loaded later than clopidogrel with greater efficacy. However, prasugrel is much more expensive than clopidogrel.

Objectives

To describe the incidence of 30‐day death from cardiovascular causes, myocardial infarction, unstable angina requiring intervention, and minor and major bleeding in patients loaded with 60 mg of prasugrel prior to percutaneous coronary intervention (PCI) and then continued on 75 mg of clopidogrel daily after the procedure.

Methods

We reviewed sequential medical records of 102 patients (Mean age: 67.8, male 68.6%, smokers: 22.6%, BMI: 29.5%, hypertension: 90.2%, DM: 33.3%, average ejection fraction: 49.7%) who underwent PCI (3.9% STEMI, 12.7% NSTEMI, 35.3% unstable angina and 48.1% electively) at Baylor University Medical Center between October 2009 and December 2011 who were loaded with prasugrel 60 mg prior to procedure, and then continued on 75 mg clopidogrel daily.

Results

None of the patients died or experienced a myocardial infarction (MI) within 30 days of the procedure. Three patients experienced unstable angina requiring intervention but none had in‐stent thrombosis or restenosis on repeat angiography. None of the patients experienced a major bleeding event. One patient developed a gastrointestinal bleed which did not require blood transfusion and the bleeding it resolved on discontinuation of the clopidogrel.

Conclusion

In this retrospective pilot study, a strategy of loading patients needing PCI with prasugrel 60 mg immediately prior to coronary intervention, then continuation of anti‐platelet therapy with 75 mg clopidogrel daily was safe and effective. (J Interven Cardiol 2013;26:38–42)
Frequency of Coronary Angiography and Revascularization among Men and Women with Myocardial Infarction and Their Relationship to Mortality at One Year: An Analysis of the Geisinger Myocardial Infarction Cohort
Authors: SKELDING KIMBERLY A. , BOGA GOUTHAMI , SARTORIUS JENNIFER , WOOD G. CRAIG , BERGER PETER B. , MASCARENHAS VERNON H. , GOOD CHRISTOPHER W. , SCOTT THOMAS D. , BLANKENSHIP JAMES C.
Published: January 2013

Objectives

To determine sex bias in the selection of strategies to evaluate patients with acute myocardial infarction (AMI), and determine if the choice of strategy influences survival.

Background

Controversy exists regarding the role of female sex in the use of invasive evaluation for AMI and its possible effect on adverse outcomes.

Methods

Electronic health record data from the Geisinger Acute Myocardial Infarction Cohort (GAMIC) was analyzed which included 1,968 men and 1,047 women admitted to the Geisinger Medical Center between January 2001 and December 2006 with acute myocardial infarction (AMI).Multivariate logistic regression analyses were used to determine independent correlates of an invasive evaluation. Multivariate logistic regression modeling stratified on sex was used to determine when invasive evaluation was done and whether there was a correlation with mortality.

Results

In unadjusted analyses, male sex was a significant predictor for the use of invasive evaluation (odds ratio = 1.71, 95% CI = [1.46, 2.00]). Adjusted for baseline differences (like age, renal function, co‐morbid conditions) multivariate analyses found no significant relationship between male sex and invasive evaluation (OR = 1.02, 95% CI = [0.82, 1.23]). Females in the STEMI group were found to be less revascularized. No difference was observed in the one‐year mortality between women and men regardless of invasive evaluation or revascularization.

Conclusions

Sex was not independently associated with the occurrence of an invasive evaluation of a MI. Females in the STEMI group were less revascularized. There was no strong gender effect on survival irrespective of the performance on an invasive evaluation or revascularization. (J Interven Cardiol 2013;26:14–21)
Elevated cyclinD1 expression is governed by plasmaIGF‐1 throughRas/Raf/MEK/ERKpathway in rumen epithelium of goats supplying a high metabolizable energy diet
Authors: Lu J. , Zhao H. , Xu J. , Zhang L. , Yan L. , Shen Z.
Published: January 2013

The objective of this study was to explore the underlying mechanism of insulin‐like growth factor 1 (IGF‐1)–caused cell proliferation of rumen epithelium in goats fed a high metabolizable energy (ME) diet. In this study, young goats were fed either a lowME[LL,n = 9,ME: 0.57 MJ/kg0.75/day] or highME[HL,n = 9,ME: 1.00 MJ/(kg0.75/day)] diet for 42 day. The time duration ofG1‐phase was shortened as a result of enhanced expression of cyclinD1mRNAin theHLgroup (p < 0.05). It was suggested that a highMEdiet promoted cell transition fromG0/G1toS‐phase via cyclinD1. The level of phosphorylation ofERKwas higher inHLthanLLgroup (p < 0.05). In cell culture, theERKwas phosphorylated byIGF‐1 treatment. The proliferative effects of insulin‐like growth factor 1 (IGF‐1, 25 ng/ml) on [3H] thymidine (TdR) incorporation intoDNAand on cyclinD1 protein expression of rumen epithelial cells were inhibited byPPP(the inhibitor of type 1 IGF receptor) (p < 0.05) andERKinhibitor (p < 0.05)in vitro. Thus,IGF‐1 up‐regulated cyclinD1 expression and acceleratedG1‐phase progression in the cell cycle throughRas/Raf/MEK/ERKpathway in rumen epithelium of goats.