bluuebunny/crossref_metadata_2025 huggingface dataset:
Co-limitation of nitrogen and water, and yield and resource-use efficiencies of wheat and barley
Authors: Cossani C. Mariano , Slafer Gustavo A. , Savin Roxana
Published: October 2010

In semiarid Mediterranean environments, low nitrogen (N) and water availabilities are key constraints to cereal productivity. Theoretically, for a given level of N or water stress, crops perform better when co-limitation occurs. Empirical evidence of this theoretical concept with field crops is rather scarce. Using data from field experiments we evaluated whether N-use efficiency (NUE) and water-use efficiency (WUE) in small grain cereals increases with the degree of co-limitation. Four field experiments were carried out during three growing seasons including factorial combinations of bread wheat, durum wheat and barley, grown under different N fertiliser rates and water regimes. Yield gap was calculated as the difference between maximum attainable yield and actual yield while stress indices for N (NSI) or water (WSI) were calculated as the ratios between actual N uptake or water use and those required to achieve maximum yields, respectively. Water and N co-limitation was calculated as C WN = 1 – |NSI–WSI|. The relationships of yield gap, NUE and WUE with the different co-limitation indices were evaluated. Yield gap (range from –3.8 to –8.1 Mg ha–1) enlarged (was more negative) with the highest levels of stress and, as expected from theory, it was reduced with the degree of co-limitation. WUE ranged from 6.3 to 21.8 kg ha–1 mm–1 with the maximum values observed under conditions in which co-limitation increased. Reduction in yield gap with increased degree of co-limitation was mainly due to a positive effect of this variable on WUE.
The Land Use Sequence Optimiser (LUSO): A theoretical framework for analysing crop sequences in response to nitrogen, disease and weed populations
Authors: Lawes Roger , Renton Michael
Published: October 2010

The break crop effect, where a non-cereal crop provides relief from soil pathogens, may increase soil nitrogen reserves for a cereal and help minimise populations of herbicide resistant weeds. It is widely used in agriculture to maximise the economic return and yield of cereal crops. In Western Australia, cereal crops are being grown with increasing frequency, at the expense of less profitable break crops and we have developed a land use sequence optimiser (LUSO) to analyse strategic break crop decisions across a suite of price, yield, nitrogen fertiliser cost, soil borne disease load and weed load thresholds. The model is flexible and can easily be parameterised for a wide range of economic, edaphic and biotic parameters. We demonstrate its use in a strategic sense to determine economic and biotic thresholds that force a rotation change in a typical Western Australian cropping system.
Genetic compatibility among domesticated and wild accessions of the tropical tuberous legume Vigna vexillata (L.) A. Rich.
Authors: Damayanti F. , Lawn R. J. , Bielig L. M.
Published: October 2010

Phenotypic similarities and differences between a cultivated variety of the tuberous legume Vigna vexillata from Bali, Indonesia, the putative domesticated variety macrosperma and wild types from Africa, Australia and Indonesia, were reported previously. The present study was undertaken to establish the genetic compatibility of these three accession classes. Seventeen accessions, comprising eight cultivated Bali accessions, one var. macrosperma accession and eight wild accessions from Africa and Austronesia, were grown in large pots in shade house facilities in Townsville, Australia. Not all hybrid combinations were attempted because for some accession combinations, suitable matching flowers were not available at the same time. The main aim was to attempt enough crosses between accessions from the respective classes to establish whether the classes were genetically compatible. Hybridisation was conducted by hand pollination in the morning, using newly-open flowers that had been emasculated before sunset on the day before. Pods and viable hybrid seed were obtained from the Bali × Bali, var. macrosperma × wild and wild African × wild Austronesian combinations. However, difficulty was encountered in obtaining viable and/or self-fertile hybrids between the Bali accessions and the other two classes. Depending on the particular combination of parental accessions, different genetic breakdown mechanisms were observed with the Bali × var. macrosperma and Bali × wild combinations. In some instances, flowers failed to set pods and/or the young pods abscised before maturity; pods set but seed were shrivelled and/or non-viable; viable seeds were set but the hybrid seedling plants were short-lived; or, in a few instances (Jimbaran Bali × wild Austronesian), vigorous hybrid plants were obtained but were self-sterile. Mitotic chromosome counts showed there was no difference in chromosome number between the Bali accessions, the Austronesian accessions and those hybrids that were viable but infertile. All exhibited 2n = 22. Pollen viability analyses using Alexander’s stain indicated that the numbers of pollen grains per flower and the percentages of pollen grain that were viable were substantially lower in the hybrids than in both the cultivated Bali and wild parental accessions. Consistent with this observation, small numbers of viable seeds were obtained when viable pollen from the respective parents was backcrossed onto the self-sterile hybrids. The results suggested that the cultivated Bali accessions do not belong to the same primary gene pool as the other cultivated and wild V. vexillata accessions and that it would be difficult to use the Bali accessions and var. macrosperma concurrently to breed seed crop varieties. A taxonomic review of V. vexillata is also warranted.
Expression of qualitative and quantitative traits in hybrids between domesticated and wild accessions of the tropical tuberous legume Vigna vexillata (L.) A. Rich.
Authors: Damayanti F. , Lawn R. J. , Bielig L. M.
Published: October 2010

The expression of morphological, phenological and agronomic traits was recorded in parents and progeny of hybrids between domesticated and wild accessions of the tropical tuberous legume Vigna vexillata (L.) A. Rich. Generally similar patterns were observed in hybrid populations between the putative domesticate var. macrosperma and wild Australian and African accessions, and between a cultivated Bali variety and a wild Australian accession, although observations in the latter populations were severely constrained by genetic incompatibilities between the parents. Several traits of domestication, including broad leaflet size, ovate leaflet shape, non-pigmented stems, non-dehiscent pods, uniform seed testa colour and green seed testa were recessive to the wild type traits and under simple genetic control, with genetic linkages evident between several wild type traits. Most morphological and phenological traits were under quantitative genetic control with high to very high broad sense heritability and moderate to very high narrow sense heritability, indicating good prospects for advance through breeding and selection. An exception was time to flowering, where there were discontinuities in frequency distributions of F2 and backcross populations, with some apparent dominance for earliness over lateness. Another exception was the number of seeds per pod, which in the var. macrosperma × wild populations, appeared to be under qualitative di-allelic control, with homozygous plants having nearly twice the number of seeds per pod as heterozygous plants. In some populations, there was apparent hybrid vigour for vegetative growth and tuber size attributes. It was concluded that the wild African and Australian accessions could be used along with var. macrosperma for breeding improved varieties of V. vexillata for forage, cover crop and vegetable uses. However, for improved pod and seed attributes, particularly the yield, size and appearance of seeds, emphasis needs to be placed on sourcing greater genetic diversity within var. macrosperma and within the cultivated Bali variety, which, because of their genetic incompatibility, will need to be the focus of separate breeding programs.
Planar oxide supported rhodium nanoparticles as model catalysts
Authors: McClure Sean M. , Lundwall M. J. , Goodman D. W.
Published: October 2010

C
2
H
4
/CO/H
2
reaction is investigated on Rh/SiO
2
model catalyst surfaces. Kinetic reactivity and infrared spectroscopic measurements are investigated as a function of Rh particle size under near atmospheric reaction conditions. Results show that propionaldehyde turnover frequency (TOF) (CO insertion pathway) exhibits a maximum activity near 〈
d

p

〉 = 2.5 nm. Polarization modulation infrared reflection absorption spectroscopy under CO and reaction (C
2
H
4
/CO/H
2
) conditions indicate the presence of Rh carbonyl species (Rh(CO)
2
, Rh(CO)H) on small Rh particles, whereas larger particles appear resistant to dispersion and carbonyl formation. Combined these observations suggest the observed particle size dependence for propionaldehyde production via CO insertion is driven by two factors: (
i
) an increase in propionaldehyde formation on undercoordinated Rh sites and (
ii
) creation of carbonyl hydride species (Rh(CO)H)) on smaller Rh particles, whose presence correlates with the lower activity for propionaldehyde formation for 〈
d

p

〉 < 2.5 nm.
Identification of a helical intermediate in trifluoroethanol-induced alpha-synuclein aggregation
Authors: Anderson Valerie L. , Ramlall Trudy F. , Rospigliosi Carla C. , Webb Watt W. , Eliezer David
Published: October 2010

Because oligomers and aggregates of the protein α-synuclein (αS) are implicated in the initiation and progression of Parkinson’s disease, investigation of various αS aggregation pathways and intermediates aims to clarify the etiology of this common neurodegenerative disorder. Here, we report the formation of short, flexible, β-sheet-rich fibrillar species by incubation of αS in the presence of intermediate (10–20% v/v) concentrations of 2,2,2-trifluoroethanol (TFE). We find that efficient production of these TFE fibrils is strongly correlated with the TFE-induced formation of a monomeric, partly helical intermediate conformation of αS, which exists in equilibrium with the natively disordered state at low [TFE] and with a highly α-helical conformation at high [TFE]. This partially helical intermediate is on-pathway to the TFE-induced formation of both the highly helical monomeric conformation and the fibrillar species. TFE-induced conformational changes in the monomer protein are similar for wild-type αS and the C-terminal truncation mutant αS1-102, indicating that TFE-induced structural transitions involve the N terminus of the protein. Moreover, the secondary structural transitions of three Parkinson’s disease-associated mutants, A30P, A53T, and E46K, are nearly identical to wild-type αS, but oligomerization rates differ substantially among the mutants. Our results add to a growing body of evidence indicating the involvement of helical intermediates in protein aggregation processes. Given that αS is known to populate both highly and partially helical states upon association with membranes, these TFE-induced conformations imply relevant pathways for membrane-induced αS aggregation both in vitro and in vivo.
Photooxidation of cytochrome P450-BM3
Authors: Ener Maraia E. , Lee Young-Tae , Winkler Jay R. , Gray Harry B. , Cheruzel Lionel
Published: October 2010

High-valent iron-oxo species are thought to be intermediates in the catalytic cycles of oxygenases and peroxidases. An attractive route to these iron-oxo intermediates involves laser flash-quench oxidation of ferric hemes, as demonstrated by our work on the ferryl (compound II) and ferryl porphyrin radical cation (compound I) intermediates of horseradish peroxidase. Extension of this work to include cytochrome P450-BM3 (CYP102A1) has required covalent attachment of a Ru
II
photosensitizer to a nonnative cysteine near the heme (

), in order to promote electron transfer from the Fe
III
porphyrin to photogenerated Ru
III
. The

conjugate was structurally characterized by X-ray crystallography (2.4 Å resolution; Ru-Fe distance, 24 Å). Flash-quench oxidation of the ferric-aquo heme produces an Fe
IV
-hydroxide species (compound II) within 2 ms. Difference spectra for three singly oxidized P450-BM3 intermediates were obtained from kinetics modeling of the transient absorption data in combination with generalized singular value decomposition analysis and multiexponential fitting.
Typologies and phases in nationalism studies: Hroch's A-B-C schema as a basis for comparative terminology
Authors: Maxwell Alexander
Published: October 2010

The study of nationalism encompasses so many themes that scholarly communication between different subfields has become difficult. Scholars might facilitate comparison by acknowledging different types of nationalism, but an overview of various taxonomies of nationalism shows that binary taxonomies have a problematic normative subtext, while most non-binary taxonomies have failed to reach a broad audience. Miroslav Hroch, who intended his A-B-C phases to schematize non-state national awakening, also devised a taxonomy of nationalism. Hroch's work has influenced nationalism scholars mostly through its phase theory of how individual national movements develop over time. While other phase theorists have proposed similar schema, Hroch's work has attracted such a wide audience that it provides scholars with a solution to the problem of inter-disciplinary communication: it offers a useful terminology for classifying and describing various sorts of nationalism.
Uninvited guests in the communal apartment: nation-formation processes among unrecognized Soviet nationalities
Authors: Appleby Ian
Published: October 2010

Following the collapse of the Soviet Union, a body of scholarship arose which effectively bypassed Miroslav Hroch's work on the emergence of small nations. Rogers Brubaker, Yuri Slezkine and Ronald Suny, among others, persuasively argued that Soviet nationalities policies shaped the ethnogeographic make-up of the post-Soviet space some sixty or seventy years later: it had become literally almost unimaginable to conceive of national affiliation outside of institutionalized forms. This analysis also convincingly accounted for the relative weakness of ethnic Russian identity in contrast to the assertive nationalism of non-Russian nationalities around the time of the USSR's collapse. The Kuban’ Cossacks – an ethnocultural community in the south of Russia – never had official recognition as a Soviet nationality. Hroch's framework can be applied to show their clearly national characteristics and, indeed, their progress towards nationhood around the turn of the twentieth century. By reclaiming Hroch's framework for the post-Soviet context, and combining it with later scholarship, we are able to identify this process for the first time, and thus further refine our understanding of the nation-formation processes within Russia following the collapse of the Soviet Union.
Miroslav Hroch's model of small nation-formation andBegriffsgeschichte
Authors: Păltineanu Oana Sînziana
Published: October 2010

This article focuses on Miroslav Hroch's book titledSocial Preconditions of National Revival in Europeand it tries to build on Hroch's model of small nation-formation mainly on a methodological level. The aim is to incorporate the “subjective” dimension in Hroch's analysis of the “objective” factors that lead to nation-formation, by opening up the discursive level to investigation. I suggest that the comparative study of nation-formation needs to remain connected to the study of nationalism as a phenomenon, including the investigation of the discursive plane, of the political languages, and histories of concepts. In this sense, the article seeks to link Hroch's work toBegriffsgeschichteand to present a range of interpretations on how these two could work together, on a methodological level. The answers come mainly from Reinhart Koselleck's theorizing on the relation between social history and the history of concepts. This article also addresses compatibility problems that aim to encourage a more integrative type of analysis that would entail an in-depth and critical revisiting of Hroch's model. At the same time, Hroch's model proves to be flexible enough to be situated at the intersection of more types of history writing.
Twenty-five years of A-B-C: Miroslav Hroch's impact on nationalism studies
Authors: Maxwell Alexander
Published: October 2010

This year marks the 25th anniversary of the publication of Miroslav Horch's 1985Social Preconditions of National Revival in Europe: A Comparative Analysis of the Social Composition of Patriotic Groups among the Smaller European Nationsin English translation. The work first appeared asDie Vorkämpfer der nationalen Bewegungen bei den kleinen Völkern Europasin 1968. The English translator of this famous study, Ben Fowkes, has since established himself as a prolific expert on East European nationalism (1996, 1999, 2000, 2002). Hroch's work has now influenced several generations of scholars interested in many different parts of the world. To examine its influence on the course of nationalism studies, this themed issue ofNationalities Papersoffers both a retrospective on Hroch's work and discussion of its continued relevance for several different branches of nationalism studies.
TRANSNATIONALISM AND THE ROLE OF FAMILY AND CHILDREN IN INTRA-EUROPEAN LABOUR MIGRATION
Authors: Moskal Marta
Published: October 2010

Although scholarly interest in family migration is increasing, along with attention to the role of women and children in migration processes, this aspect of mobility continues to be poorly understood, particularly in the European context. Research on migration has tended to focus on primary migrants and to pay less attention to whether migrants arrive with families, resulting in a restricted picture of the impact of migration. This paper examines the presence and participation of families and children in the process of migration. It does so within the specific context of intra-European labour migration. Based on a qualitative study of migration and the integration of Polish families and children in Scotland, the paper explores changes in family structures and migration patterns that result in diverse new household migration behaviours. It argues that the locations of migrants within the European Community have become more fluid, with families being increasingly likely to inhabit more than one residence. It also argues that the uniqueness of the European setting requires a coherent theoretical focus and conceptual framework for understanding the implications of family migration. It suggests that transnational lenses generate useful empirical approaches concerning migration movements within the European Community. The paper explores transnational migration theory in relation to Polish post-enlargement migration and examines the multiple ways in which families may change through migration. It analyses the role of gender (women and men) and generations (grandparents, parents and children) in migration and settlement in the new country.
Neural temporal dynamics of contingency judgement
Authors: Heisz Jennifer J. , Hannah Samuel , Shedden Judith M. , Allan Lorraine G.
Published: October 2010

The present study captures the dynamics of neural processing across positively contingent, negatively contingent, and noncontingent relations. In the setting of a hypothetical chat room conversation, participants rated the contingency of emotional response between two individuals. Event-related potentials (ERPs) were time-locked to the onset of each emotional event. Although each event alone was ambiguous regarding contingency, its neural response was characteristic of the overall contingent relation and the subsequent contingency rating. Very early displays of contingency modified the ERP anterior N1 (AN1) component amplitude. In contrast, the ERP selection negativity (SN) component amplitude seemed to be more sensitive to display properties than contingency. Our results point to the recruitment of early attentional processes for contingency judgement and highlight the efficiency of statistical information processing.
The L'Aquila Earthquake of 6 April 2009 and Italian Government Policy on Disaster Response
Authors: Alexander David E.
Published: October 2010

This paper describes the impact of the earthquake that struck the central Italian city of L'Aquila on 6 April 2009, killing 308 people and leaving 67 500 homeless. The pre-impact, emergency, and early recovery phases are discussed in terms of the nature and effectiveness of government policy. Disaster risk reduction (DRR) in Italy is evaluated in relation to the structure of civil protection and changes wrought by both the L'Aquila disaster and public scandals connected with the misappropriation of funds. Six of the most important lessons are derived from this analysis and related to DRR needs both in Italy and elsewhere in the world.
Using Natural Capital to Reduce Disaster Risk
Authors: Kousky Carolyn
Published: October 2010

Natural capital can be used to reduce disaster losses; for example, wetlands store floodwaters and mangroves buffer storm surge. This paper reviews the experience of several US communities that chose to use natural systems to mitigate a variety of risks. The paper discusses the communities' motivations in choosing to use natural capital as opposed to other risk-reduction measures, the policy approaches for doing so, the political and institutional challenges involved, and strategies for overcoming those challenges.
Negotiation Support for Environmental Disaster Management: Drama Theory II and the Survival of Louisiana's Indigenous Gulf Coast Tribes
Authors: Levy Jason K.
Published: October 2010

A formal group decision and negotiation framework known as Drama Theory II(DT II) is put forth in order to systematically model environmental disasters and to examine ways to improve the resilience of Louisiana's indigenous Gulf Coast tribes that have lived on the bayous of the Mississippi delta for centuries. A mathematical treatment of key drama theoretic concepts (i.e. positions, intentions, doubts, and dilemmas) is provided, the dynamics of the drama theoretic process are discussed and theoretical results are applied to the ongoing oil spill disaster in the US Gulf Coast. While game theoretic tools have been widely applied to disaster management issues, traditional decision analysis assumes that decision-makers, options, and preferences are fixed. On the other hand, DT II, a theory of mutual interactive game design, allows for the redefinition of the conflict and emphasizes that decision-makers engage in a rational-emotional process of redefining both the game and their ‘positions’ in it until agreement on a satisfactory resolution is reached. Results show that drama theory constitutes an adaptive and powerful tool for modelling the Gulf Coast oil spill and for helping to strengthen the resilience of Louisiana's Gulf tribes which are on the brink of disaster. By identifying transformative natural resources policy options, it is shown how environmental health risks can be reduced and a more sustainable future can be promoted.
Aptamer conjugated magnetic nanoparticles as nanosurgeons
Authors: Nair Baiju G , Nagaoka Yutaka , Morimoto Hisao , Yoshida Yasuhiko , Maekawa Toru , Sakthi Kumar D
Published: October 2010

Magnetic nanoparticles have shown promise in the fields of targeted drug delivery, hyperthermia and magnetic resonance imaging (MRI) in cancer therapy. The ability of magnetic nanoparticles to undergo surface modification and the effect of external magnetic field in the dynamics of their movement make them an excellent nanoplatform for cancer destruction. Surgical removal of cancerous or unwanted cells selectively from the interior of an organ or tissue without any collateral damage is a serious problem due to the highly infiltrative nature of cancer. To address this problem in surgery, we have developed a nanosurgeon for the selective removal of target cells using aptamer conjugated magnetic nanoparticles controlled by an externally applied three-dimensional rotational magnetic field. With the help of the nanosurgeon, we were able to perform surgical actions on target cells inin vitrostudies. LDH and intracellular calcium release assay confirmed the death of cancer cells due to the action of the nanosurgeon which in turn nullifies the possibility of proliferation by the removed cells. The nanosurgeon will be a useful tool in the medical field for selective surgery and cell manipulation studies. Additionally, this system could be upgraded for the selective removal of complex cancers from diverse tissues by incorporating various target specific ligands on magnetic nanoparticles.
An efficient and biocompatible fluorescence resonance energy transfer system based on lanthanide-doped nanoparticles
Authors: Di Weihua , Li Jie , Shirahata Naoto , Sakka Yoshio
Published: October 2010

This work demonstrates an efficient and bio-friendly fluorescence resonance energy transfer (FRET) system based on lanthanide-doped inorganic nanoparticles. A facile aqueous route was used to synthesize the CePO4:Tb nanorods with homogeneous colloidal dispersion, which emits a bright green light with a high quantum yield (∼0.36) and a long fluorescence lifetime (∼3.50 ms) upon UV excitation. Upon treatment of CePO4:Tb with aqueous Rhodamine B (RhB), an efficient FRET occurs from the Tb3 +to the RhB molecules, giving rise to well resolved and ratiometric emissions of donors and acceptors, respectively, with an energy transfer efficiency of up to 0.85. When incubated with HeLa cells at 37 °C, the CePO4:Tb treated with RhB shows bright intracellular luminescence, indicating that it can be successfully internalized inside the cells and the FRET remains in the living cells. Moreover, the cytotoxic measurements demonstrate good biocompatibility and low cytotoxicity of our present FRET system. The advantages presented above including high quantum yield of donors, high energy transfer efficiency, ratiometric fluorescent emission and good biocompatibility, indicate the high potential of the CePO4:Tb/RhB FRET system for monitoring biological events.
Predischarge Angiographical Evaluation of Radial Artery Graft Harvested by Endoscopic Harvesting System
Authors: Sato Manabu , Suenaga Etsuro , Koga Shugo , Kawasaki Hiromitsu , Iwasaki Yoshihiro , Katayama Toshirou
Published: October 2010

Objective

Endoscopic radial artery harvesting (ERAH) has superior cosmetic advantages over conventional harvesting methods. With instrumental advancements, these techniques have become easier to adopt and require less time to learn. In most reported cases, the quality of harvested conduits is discussed based on macroscopic and histologic examinations and clinical outcomes. However, predischarge angiography gives a straightforward answer regarding quality of harvested conduit. The aim of this study is to assess the quality of endoscopically harvested radial artery by predischarge angiographic evaluation.

Methods

Endoscopic procedure using VasoView 4 system was performed in 87 patients between September 2004 and December 2007, and 78 predischarge angiographical evaluations were completed and reviewed. Mean age of the patients was 66 ± 10 years and 18% were women. After ERAH was performed, accompanying veins were dissected by ultrasound scalpel. All conduits were as aortocoronary bypass under cardiopulmonary bypass.

Results

Mean arm ischemic time was 32 ± 13 minutes and length of harvested conduit was 17.8 ± 1.3 cm. Predischarge angiography demonstrated two occlusions at the proximal anastomosis in the 51st and 71st cases, although intraoperative flow study showed normal flow patterns in both cases. Stenosis in the conduits was observed in the first, sixth, and seventh cases. No further angiographical problems were found in the remaining conduits.

Conclusions

Based on the angiographical results, problems with the harvested conduits occurred only in initial period. ERAH with VasoView system provides satisfactory angiographical quality after initial learning curve.
The Use of the Impella RD as a Bridge to Recovery for Right Ventricular Dysfunction after Cardiac Transplantation
Authors: Bennett Matthew T. , Virani Sean A. , Bowering John , Ignaszewski Andrew , Kaan Anne-Marie F. , Cheung Anson
Published: October 2010

Right ventricular failure after orthotopic heart transplantation is associated with significant mortality and morbidity. We report the use of a paracardiac microaxial pump, the Impella RD, as a bridge to recovery in a patient with right ventricular infarction after orthotopic heart transplantation.
A Novel Surgical Approach to Cardiac Autotransplantation in Complex Cardiac Sarcoma Resection
Authors: Wu James T. , Frazier O. H. , Nasser Maher M. , Reul Ross M.
Published: October 2010

A 28-year-old woman was admitted to our institution, reporting progressive dyspnea, cough, and weight loss of 14 kg. Two-dimensional echocardiography revealed a left atrial mass, and cardiac magnetic resonance imaging showed localized involvement of the mass with adjacent structures. These clinical signs and radiographic images were highly suggestive of cardiac sarcoma. The patient underwent emergent mediastinal exploration, and an incisional biopsy of the mass showed high-grade sarcoma. Removing the tumor required radical en bloc resection of the left atrium, including the mitral valve, the left pulmonary vein, and the left lower lobe of the lung. Autotransplantation was necessary for the resection and reconstruction. We report a unique method of handling the right atrium to avoid the potential complications associated with bicaval anastomoses after autotransplantation.
Histologic Evaluation of Stapled Right Atrial Appendages with Fabric Buttressing
Authors: Fumoto Hideyuki , Gillinov A. Marc , Vince D. Geoffrey , Akiyama Masatoshi , Saeed Diyar , Fukamachi Kiyotaka
Published: October 2010

Objective

The aim of this study was to histologically evaluate the importance of using buttressing materials in stapling the atrial appendages.

Methods

We stapled the right atrial appendage with a commercial apparatus in 11 mongrel dogs. To evaluate the efficiency of using a buttressing material as an adjunct to stapling, we conducted 30-day studies without (group A: n = 2) or with buttressing material (group B: n = 3) and 90-day studies without (group C: n = 3) or with buttressing material (group D: n = 3) and thereafter made assessments using Doppler echocardiography and performed histologic analyses on all stapled appendages.

Results

During surgery, blood oozing from the stapling sites was observed in four of five cases of groups A and C; with buttressing, there was no oozing in groups B and D. In groups A and B, we observed the myocardium of the appendage being focally replaced with fibrous tissue. Myocardium in group C was infiltrated diffusely with loose fibrous tissue and in group D had been almost completely replaced with fibrous tissue.

Conclusions

The buttressing material was useful not only in preventing oozing but also likely promoting the growth of fibrous tissue in the right atrial appendage.
Combined Treatment of Traumatic Aortic Transection and Kommerell Diverticulum
Authors: Smith Cameron R. , Brinster Derek R.
Published: October 2010

We present the case of a 41-year-old male trauma patient admitted to the emergency department after being struck in a pedestrian versus a motor vehicle accident. Computed tomography revealed a traumatic transaction of the descending aorta with pseudoaneurysm and an aberrant right subclavian artery with Kommerell diverticulum. Surgical correction was accomplished with bilateral subclavian carotid bypass, with occlusion of both subclavian arteries followed by the placement of endovascular stent grafts to repair the aortic injury.
Aortic Valve Replacement through Right Minithoracotomy in 306 Consecutive Patients
Authors: Glower Donald D. , Lee Teng , Desai Bhargavi
Published: October 2010

Objective

To define the role and early results of aortic valve surgery through a right minithoracotomy.

Methods

A retrospective analysis was performed on 306 consecutive patients undergoing aortic valve replacement through an 8-cm right minithoracotomy in the second intercostal space. The initial experience was included. The right second and third ribs were detached from the sternum in most cases and repaired at the end of each case. Most operations were performed using anterograde and retrograde cardioplegic arrest with percutaneous femoral venous cannulation and direct aortic cannulation through the incision. Standard instruments were used with direct digital knot tying.

Results

Mean age was 65 ± 14 (range, 20–90) years. Aortic valve disease cause was calcific disease in 160 of 306 (52%) patients, bicuspid disease in 95 of 306 (31%) patients, and endocarditis in 9 of 306 (3%) patients. Previous cardiac surgery was present in 13 of 306 (4%) patients. Biologic prostheses were used in 240 of 306 (78%) patients. Median valve size was 23 mm. Mean clamp times and pump times were 103 ± 26 and 158 ± 35 minutes, respectively. Median postoperative length of stay was 5 days. Thirty-day mortality was found in 4 of 306 (1%) cases. There were no deep wound infections or mediastinitis. Stroke occurred in 5 of 306 (1.6%) patients, and new pacemaker required in 11 of 306 (4%) patients. Reoperation for bleeding occurred in 2 of 306 (1%) patients. Conversion to median sternotomy occurred in 15 of 306 (5%) patients caused by chest wall anatomy (n = 7), bleeding (n = 3), coronary disease (n = 2), or aortic disease (n = 3). Patients were allowed to return to driving or preoperative activity in 2 weeks. With a mean follow-up of 2.8 ± 2.2 years, one patient required reoperation for aortic root disease.

Conclusions

Right minithoracotomy is a safe but limited alternative to sternotomy in isolated aortic valve replacement. This approach may be particularly valuable in some higher risk, elderly patients and opens options for a hybrid approach combined with percutaneous coronary angioplasty.
Selective Beta-1 Receptor Blockade Further Reduces the Mechanically Stabilized Target Coronary Artery Motion during Beating Heart Surgery
Authors: Wakamatsu Hiroki , Watanabe Toshiki , Sato Yoshiyuki , Takase Shinya , Omata Sadao , Yokoyama Hitoshi
Published: October 2010

Objective

Adequate stabilization of anastomosis sites during off-pump coronary artery bypass is essential to obtain excellent graft patency. We examined the effect of beta-1 adrenergic receptor blockade on the target coronary artery motion by three-dimensional (3D) digital motion capture and reconstruction technology.

Methods

Eight pigs underwent a sternotomy. Reflection markers were attached to the surface coronary arteries, followed by a mechanical stabilizer application. Two high-speed digital cameras captured two-dimensional (2D) motion of the markers from different angles. These 2D data were reconstructed into 3D data points, representing the motion of each coronary artery. Landiolol hydrochloride, a novel selective beta-1 receptor blocker, was infused intravenously after acquisition of control data.

Results

Beta-1 receptor blockade decreased heart rate (105 ± 16 vs. 90 ± 9 beat/min; P = 0.007) without decreasing arterial blood pressure. The 3D distance moved (millimeter) during one cardiac cycle was significantly reduced on the left anterior descending (9.6 ± 2.8 vs. 6.6 ± 1.9 mm; P = 0.003), left circumflex (10.5 ± 6.3 vs. 6.4 ± 2.6 mm; P = 0.038), and right coronary (8.3 ± 3.6 vs. 6.5 ± 2.1 mm; P = 0.028) arteries. Reduction in the maximal velocity, maximal acceleration, and maximal deceleration of the anastomosis site in all coronary arteries was also found in a quantitative fashion.

Conclusions

Selective beta-1 receptor blockade significantly reduces the 3D motion at anastomosis sites on the beating heart, with stable systemic blood pressure. Further quantitative investigations of pharmacological stabilization are warranted to achieve better outcome of the patients undergoing off-pump coronary artery bypass surgery.
Preoperative Evaluation of Patient Anatomy to Increase Success of Robotics-Assisted Bypass Surgery
Authors: Trejos Ana Luisa , Ross Ian , Scalesse Carlie , Patel Rajni V. , Naish Michael D. , Kiaii Bob
Published: October 2010

Objective

Robotics-assisted endoscopic atraumatic coronary artery bypass has been shown to be effective in reducing surgical morbidity and length of hospital stay. Unfortunately, the criteria for selecting eligible patients for this procedure are still primitive. This has motivated the use of preoperative computed tomography scans to establish patient eligibility. The objective of this study is to establish which image measurements can be correlated to procedure success.

Methods

A retrospective study was performed in 144 patients who underwent robotics-assisted coronary bypass surgery. After an initial set of 55 patients, preoperative computed tomography scans of the other patients were used to obtain patient specific measurements: the lateral distance between the midline of the sternum to the left anterior descending coronary artery and its depth from the skin surface, anteroposterior diameter of the thoracic cavity, and the transverse diameter of the thoracic cavity. The procedures were rated as successful if completed in a minimally invasive manner. Different combinations of the variables were evaluated and correlated with success.

Results

A strong correlation was found between success rate and the ratio of the lateral distance to the transverse diameter in the female patients only (0.532, P = 0.006). A ratio of less than 0.20 significantly increased the occurrence of conversion during this procedure in female cases.

Conclusions

The lateral distance of the left anterior descending coronary artery from the midline divided by the transverse thoracic width of a female patient shows a significant correlation with procedure success. No significant correlations were found for male patients.
Decay of vertebrate characters in hagfish and lamprey (Cyclostomata) and the implications for the vertebrate fossil record
Authors: Sansom Robert S. , Gabbott Sarah E. , Purnell Mark A.
Published: October 2010

The timing and sequence of events underlying the origin and early evolution of vertebrates remains poorly understood. The palaeontological evidence should shed light on these issues, but difficulties in interpretation of the non-biomineralized fossil record make this problematic. Here we present an experimental analysis of decay of vertebrate characters based on the extant jawless vertebrates (
Lampetra
and
Myxine
). This provides a framework for the interpretation of the anatomy of soft-bodied fossil vertebrates and putative cyclostomes, and a context for reading the fossil record of non-biomineralized vertebrate characters. Decay results in transformation and non-random loss of characters. In both lamprey and hagfish, different types of cartilage decay at different rates, resulting in taphonomic bias towards loss of ‘soft’ cartilages containing vertebrate-specific Col2α1 extracellular matrix proteins; phylogenetically informative soft-tissue characters decay before more plesiomorphic characters. As such, synapomorphic decay bias, previously recognized in early chordates, is more pervasive, and needs to be taken into account when interpreting the anatomy of any non-biomineralized fossil vertebrate, such as
Haikouichthys
,
Mayomyzon
and
Hardistiella
.
Integron types, gene cassettes, antimicrobial resistance genes and plasmids of Shigella sonnei isolates from outbreaks and sporadic cases in Taiwan
Authors: Chang Chung-Yu , Lu Po-Liang , Lin Chung-Che , Lee Tsong-Ming , Tsai Mei-Yin , Chang Lin-Li
Published: October 2010

This study analysed the presence, location and transferability of integrons and antibiotic resistance genes in 103 Shigella sonnei outbreak isolates and in 32 sporadic isolates from Taiwan. Multiple antimicrobial resistance was common in both outbreak (95 %) and sporadic (97 %) isolates. Class 1 integrons were present in 34 outbreak isolates (33 %) and in six sporadic isolates (19 %). This study is the first, to our knowledge, to identify an atypical sul3-associated class 1 integron carrying the estX-psp-aadA2-cmlA-aadA1-qacH cassette array in Shigella. Class 2 integrons carrying the dfr1-sat2-aadA1 cassette array were predominant in outbreak isolates (90 %) but were not present in sporadic isolates. Other antimicrobial resistance genes not associated with integrons were found to encode resistance to ampicillin (bla
TEM), chloramphenicol (cat1), sulfonamide (sul2) and tetracycline (tetA and tetB). The most common plasmid size was 130 kb (observed in 43 and 97 % of 1998 outbreak and sporadic isolates, respectively). In conclusion, the plasmid location of resistance genes and horizontal plasmid transfer promote the spread of multiple resistance genes in outbreak and sporadic isolates of S. sonnei.
The rhizosphere-competent entomopathogen Metarhizium anisopliae expresses a specific subset of genes in plant root exudate
Authors: Pava-Ripoll Monica , Angelini Claudia , Fang Weiguo , Wang Sibao , Posada Francisco J. , St Leger Raymond
Published: October 2010

Metarhizium anisopliae and Beauveria bassiana are ubiquitous insect pathogens and possible plant symbionts, as some strains are endophytic or colonize the rhizosphere. We evaluated 11 strains of M. anisopliae and B. bassiana, and two soil saprophytes (the non-rhizospheric Aspergillus niger and the rhizosphere-competent Trichoderma harzianum) for their ability to germinate in bean root exudates (REs). Our results showed that some generalist strains of M. anisopliae were as good at germinating in RE as T. harzianum, although germination rates of the specialized acridid pathogen Metarhizium acridum and the B. bassiana strains were significantly lower. At RE concentrations of <1 mg ml−1, M. anisopliae strain ARSEF 2575 showed higher germination rates than T. harzianum. Microarrays showed that strain 2575 upregulated 29 genes over a 12 h period in RE. A similar number of genes (21) were downregulated. Upregulated genes were involved in carbohydrate metabolism, lipid metabolism, cofactors and vitamins, energy metabolism, proteolysis, extracellular matrix/cell wall proteins, transport proteins, DNA synthesis, the sexual cycle and stress response. However, 41.3 % of the upregulated genes were hypothetical or orphan sequences, indicating that many previously uncharacterized genes have functions related to saprophytic survival. Genes upregulated in response to RE included the subtilisin Pr1A, which is also involved in pathogenicity to insects. However, the upregulated Mad2 adhesin specifically mediates adhesion to plant surfaces, demonstrating that M. anisopliae has genes for rhizosphere competence that are induced by RE.
ArgR is an essential local transcriptional regulator of the arcABC operon in Streptococcus suis and is crucial for biological fitness in an acidic environment
Authors: Fulde Marcus , Willenborg Joerg , de Greeff Astrid , Benga Laurentiu , Smith Hilde E. , Valentin-Weigand Peter , Goethe Ralph
Published: October 2010

Streptococcus suisis one of the most important pathogens in pigs and can also cause severe infections in humans. Despite its clinical relevance, very little is known about the factors that contribute to its virulence. Recently, we identified a new putative virulence factor inS. suis, the arginine deiminase system (ADS), an arginine catabolic enzyme system encoded by thearcABCoperon, which enablesS. suisto survive in an acidic environment. In this study, we focused on ArgR, an ADS-associated regulator belonging to the ArgR/AhrC arginine repressor family. Using anargRknockout strain we were able to show that ArgR is essential forarcABCoperon expression and necessary for the biological fitness ofS. suis. By cDNA expression microarray analyses and quantitative real-time RT-PCR we found that thearcABCoperon is the only gene cluster regulated by ArgR, which is in contrast to the situation in many other bacteria. Reporter gene analysis withgfpunder the control of thearcABCpromoter demonstrated that ArgR is able to activate thearcABCpromoter. Electrophoretic mobility shift assays with fragments of thearcABCpromoter and recombinant ArgR, and chromatin immunoprecipitation with antibodies directed against ArgR, revealed that ArgR interacts with thearcABCpromoterin vitroandin vivoby binding to a region from −147 to −72 bp upstream of the transcriptional start point. Overall, our results show that inS. suis, ArgR is an essential, system-specific transcriptional regulator of the ADS that interacts directly with thearcABCpromoterin vivo.
Error-prone polyploid mitosis during normal Drosophila development
Authors: Fox Donald T. , Gall Joseph G. , Spradling Allan C.
Published: October 2010

Endopolyploidy arises during normal development in many species when cells undergo endocycles—variant cell cycles in which DNA replicates but daughter cells do not form. Normally, polyploid cells do not divide mitotically after initiating endocycles; hence, little is known about their mitotic competence. However, polyploid cells are found in many tumors, and the enhanced chromosomal instability of polyploid cells in culture suggests that such cells contribute to tumor aneuploidy. Here, we describe a novel polyploid Drosophila cell type that undergoes normal mitotic cycles as part of a remodeling process that forms the adult rectal papillae. Similar polyploid mitotic divisions, but not depolyploidizing divisions, were observed during adult ileum development in the mosquito Culex pipiens. Extended anaphases, chromosome bridges, and lagging chromosomes were frequent during these polyploid divisions, despite normal expression of cell cycle regulators. Our results show that the switch to endocycles during development is not irreversible, but argue that the polyploid mitotic cycle is inherently error-prone, and that polyploid mitoses may help destabilize the cancer genome.