bluuebunny/crossref_metadata_2025 huggingface dataset:
Mini-Conference on the First Microns of the First Wall
Authors: Stotler D. P. , Rognlien T. D. , Krasheninnikov S. I.
Published: May 2008

Interactions between plasmas and their surrounding materials (plasma-facing components) are of great interest to present and future magnetic fusion experiments, and ITER [ITER Physics Basis Editors, ITER Physics Expert Group Chairs, ITER Joint Central Team, and Physics Integration Unit, Nucl. Fusion 39, 2137 (1999)] in particular. This interest is the result of concerns with the survivability of these materials, as well as the impact of these interactions back on the plasma. These interactions begin on the surface, but can have consequences a few microns into the material. This mini-conference on these “first microns” was designed to bring to the Division of Plasma Physics Meeting experts on these topics who would otherwise not attend. At the same time, the mini-conference was intended to expose the broader fusion community to these issues. The mini-conference covered in three half-day sessions the topics of lithium coatings and surfaces, mixed materials characteristics, and issues associated with graphite.
Direct folding studies of various α and β strands using replica exchange molecular dynamics simulation
Authors: Kim Eunae , Jang Soonmin , Pak Youngshang
Published: May 2008

Previously we presented an all-atom force field with a generalized Born solvation model (param99MOD5/GBSA) for a more balanced description of α∕β propensities. We performed direct folding simulations on α helices (PDB code 2I9M and 1WN8), β hairpins (15β peptide and PDB code 1E0Q), and β-sheet peptide (PDPD-II) to investigate the transferability of a new param99MOD5/GBSA force field. For direct folding simulations, we used the replica exchange molecular dynamics simulation starting with a fully extended conformer. In the converged free energy landscapes for all five peptides, each of the lowest free energy predicted structures closely matched the corresponding NMR native structure within a backbone rmsd value of 2.0Å at experimental temperatures. The thermal denaturation profiles of all the peptides fit a two-state model well, giving several key thermodynamic parameters for comparison. Especially for 15β and PDPD-II whose thermodynamic data were available from the experiment, our simulated thermodynamic quantities agree reasonably well with the experiment. In this work, we demonstrate that the modified force field successfully differentiates native structures of α and β strands under the global free energy minimum condition, so that it can be used in ab initio folding simulations for more complex motifs.
Exp6-polar thermodynamics of dense supercritical water
Authors: Bastea Sorin , Fried Laurence E.
Published: May 2008

We introduce a simple polar fluid model for the thermodynamics of dense supercritical water based on a Buckingham (exp-6) core and point dipole representation of the water molecule. The proposed exp6-polar thermodynamics, which is based on ideas originally applied to dipolar hard spheres, performs very well when tested against molecular dynamics simulations. Comparisons of the model predictions with experimental data available for supercritical water yield excellent agreement for the shock Hugoniot, isotherms, and sound speeds, and are also quite good for the self-diffusion constant and relative dielectric constant.
Computation of interior eigenvalues in electronic structure calculations facilitated by density matrix purification
Authors: Rubensson Emanuel H. , Zahedi Sara
Published: May 2008

Density matrix purification, is in this work, used to facilitate the computation of eigenpairs around the highest occupied and the lowest unoccupied molecular orbitals (HOMO and LUMO, respectively) in electronic structure calculations. The ability of purification to give large separation between eigenvalues close to the HOMO-LUMO gap is used to accelerate convergence of the Lanczos method. Illustrations indicate that a new eigenpair is found more often than every second Lanczos iteration when the proposed methods are used.
Waterlike dynamic anomalies in a liquid described by a core-softened potential
Authors: Egorov S. A.
Published: May 2008

We present a theoretical study of transport properties of a liquid comprised of particles interacting via isotropic core-softened potential. Shear viscosity and self-diffusion coefficient are computed on the basis of the mode-coupling theory, with required structural input obtained from thermodynamically self-consistent integral equation theory. Both self-diffusion coefficient and viscosity display waterlike anomalous density dependence, with diffusivity increasing and viscosity decreasing with density within a particular density range along several isotherms below a certain temperature. Our theoretical results for both transport coefficients are in good agreement with the simulation data.
A demountable nonmagnetic multiconductor feedthrough suitable for use in liquid helium applications
Authors: Bass Christopher D.
Published: May 2008

A superfluid-helium-tight nonmagnetic electrical feedthrough has been developed by using brass pins embedded within an epoxy resin plug and mounted on a beryllium copper Conflat flange. A method for building these feedthroughs is discussed, and their performance history is described.
Advanced light trapping management by diffractive interlayer for thin-film silicon solar cells
Authors: Obermeyer Philipp , Haase Christian , Stiebig Helmut
Published: May 2008

Thin-film silicon solar cells made of amorphous and microcrystalline silicon in tandem cell configuration enable high efficiency and low-cost production. Precise control of the absorption in each diode by a wavelength-selective and diffractive interlayer provides optimized current matching. For this purpose, intermediate reflectors with periodically textured interfaces are investigated. The propagation of electromagnetic waves is simulated using a three dimensional Maxwell solver which considers both near field and far field optics. Design rules for intermediate reflectors and textured interfaces are presented.
Lithographic alignment to site-controlled quantum dots for device integration
Authors: Schneider C. , Strauß M. , Sünner T. , Huggenberger A. , Wiener D. , Reitzenstein S. , Kamp M. , Höfling S. , Forchel A.
Published: May 2008

We report on a scalable fabrication technology for devices based on single quantum dots (QDs) which combines site-controlled growth of QDs with an accurate alignment procedure. Placement of individual QDs and corresponding device structures with a standard deviation of around 50nm from the target position was achieved. The potential of the technology is demonstrated by fabricating arrays of mesas, each containing one QD at a defined position. The presence of single, optically active QDs in the mesas was probed by scanning microphotoluminescence of the mesa arrays.
Abundance and distribution of South Australia's endemic sea star, Parvulastra parvivipara (Asteroidea: Asterinidae)
Authors: Roediger Lana M. , Bolton Toby F.
Published: May 2008

Parvulastra parvivipara is one of the smallest sea stars. It is restricted to tide pools on seven granite platforms within 200 km of coastline on the Eyre Peninsula of South Australia. This species exhibits intragonadal brooding and cannibalism of offspring, and gives birth to non-dispersive juveniles. Its distribution is variable, with specimens occupying few of the many seemingly similar tide pools at each site at differing densities. The abundance and distribution of P. parvivipara were examined in relation to twelve ecological variables of tide pools at all known mainland sites. An estimate of overall population size was also made. Multiple regression analyses showed that the abundance of P. parvivipara was negatively associated with wave-exposure and positively associated with the structural complexity of tide pools. A multiple logistic regression also indicated that the presence of sea stars (distribution) was more likely in structurally complex tide pools with low wave-exposure. Additionally, increasing elevation of a tide pool relative to the high-tide margin within the intertidal zone reduced the likelihood of finding sea stars. It is suggested that the variable abundance and distribution of P. parvivipara may be driven by broad scale ecological variables (e.g. complexity and wave-exposure), localised population extinctions (within tide pools) and recolonisation of tide pools via transportation of individuals across the rock platforms by wave-energy. It is also suggested that strikingly high abundances of P. parvivipara in some tide pools are likely to result from the reproductive mode of this species where each hermaphroditic individual gives birth to cohorts of up to twenty non-dispersive juveniles.
Approach to ageing and growth back-calculation based on the otolith of the southern boarfish Pseudopentaceros richardsoni (Smith, 1844) from the south-west Indian Ocean seamounts
Authors: López-Abellán Luis J. , Santamaría María T. G. , González José F.
Published: May 2008

Age and growth of southern boarfish Pseudopentaceros richardsoni (Smith 1844) from south-west Indian Ocean seamounts were studied based on whole otolith readings using a non-linear back-calculation method and geometric mean regression to resolve the problem of the lack of young fish in the catches owing to age segregated habitat use by this species. Ages of the fish under study ranged from between 5 and 14 years (45.7–72.5 cm total length). Changes in relative growth of annuli were most probably related to aspects of the life history, such as migration to settle on seamounts. Age distribution was related to depth. The von Bertalanffy growth parameters for all individuals were L∞ = 65.1 cm; K = 0.27 year–1 and t0 = –0.34 years, obtained by mean length-age from back-calculated lengths. These data are needed to assist in the wise management of this potential fishery and the back-calculation approach shows promise for other species where juvenile fish are difficult to obtain. It is also clear that more information about the southern boarfish biology is needed to establish bases for a responsible fishery development off the seamounts of the Southern Indian Ocean and other deep-sea regions.
Key Role of Platelet Procoagulant Activity in Tissue Factor‐and Collagen‐Dependent Thrombus Formation in Arterioles and Venules In Vivo Differential Sensitivity to Thrombin Inhibition
Authors: Kuijpers Marijke J.E. , Munnix Imke C.A. , Cosemans Judith M.E.M. , Vlijmen Bart J. Van , Reutelingsperger Chris P.M. , Egbrink Mirjam G.A. Oude , Heemskerk Johan W.M.
Published: May 2008

Objective: Blood coagulation and platelet activation are mutually dependent processes, but contribute differently to venous and arterial thrombosis. We investigated the interplay of these processes in vivo in a mouse model of arteriolar and venular thrombus formation.

Methods: Thrombus formation was studied by intravital (fluorescence) microscopy after topical application of FeCl3 on mouse mesenteric microvessels.

Results: Both in arterioles and venules, the thrombus‐forming process relied on tissue factor‐factor VII(a) interaction, collagen exposure, and glycoprotein VI–mediated platelet activation. Arterial thrombus formation was impaired by mild thrombin inhibition or platelet inhibition, while venous thrombosis was only suppressed by strong thrombin inhibition or by mild thrombin inhibition together with platelet inhibition. Phosphatidylserine‐exposing platelets were present in thrombi of both vessel types, as detected with fluorescently labeled annexin A5. Injection of annexin A5 to shield exposed phosphatidylserine abolished thrombus formation in arterioles and venules, while mutant M1234‐annexin A5 was ineffective. Arterial and venous thrombus formations were only slightly affected in mice carrying the factor V Leiden mutation, suggesting insensitivity to factor Va inactivation.

Conclusions: In this microvascular model, the formation of both arterial and venous thrombi relies on collagen‐induced platelet activation and tissue factor–induced thrombin generation. Activated, phosphatidylserine‐exposing platelets play a key role in thrombus growth in arterioles and venules.
Inflammatory and Hemodynamic Changes in the Cerebral Microcirculation of Aged Rats after Global Cerebral Ischemia and Reperfusion
Authors: Ritter Leslie , Funk Janet , Schenkel Lori , Tipton Alicia , Downey Kate , Wilson Jonathan , Coull Bruce , Mcdonagh Paul
Published: May 2008

Effects of aging on inflammation and blood flow in the brain are unclear. Young (three to six months) and aged (19–22 months) male Brown Norway Fisher rats were used to compare (i) leukocyte function in nonischemic conditions and (ii) leukocyte function and hemodynamic changes after ischemia‐reperfusion (I‐R). In nonischemic studies, polymorphonuclear (PMN) CD11b expression and reactive oxygen species (ROS) production were measured with flow cytometry and PMN chemotaxis was measured with a Boyden chamber (+/‐fMLP). In I‐R studies, ischemia was induced by bilateral carotid artery occlusion and hypotension (20 minutes). During early reperfusion (30 minutes), leukocyte adhesion and rolling and blood‐shear rates were measured using fluorescence microscopy. During late reperfusion (48 hours), mortality, neurological function, and leukocyte infiltration were measured. Stimulated PMN chemotaxis was increased in nonischemic aged rats (p < 0.05). In early reperfusion, there was a significant increase in leukocyte rolling and adhesion in the cerebral microcirculation and a significant decrease in shear rate in aged rats, compared to the young (p < 0.05). During late reperfusion, neurologic function was worse in aged vs. young rats (p < 0.05). These findings suggest that increased intravascular PMN adhesion and vascular dysfunction may contribute to poor neurologic outcome after cerebral I‐R in the aged brain.
Critical Role of FcR γ‐Chain, LAT, PLCγ2 and Thrombin in Arteriolar Thrombus Formation upon Mild, Laser‐Induced Endothelial Injury In Vivo
Authors: Kalia Neena , Auger Jocelyn M. , Atkinson Ben , Watson Steve P.
Published: May 2008

Objective: The role of collagen receptor complex GPVI‐FcR γ‐chain, PLCγ2 and LAT in laser‐induced thrombosis is unclear. Controversy surrounds whether collagen is exposed in this model or whether thrombosis is dependent on thrombin. This study hypothesized that collagen exposure plays a critical role in thrombus formation in this model, which was tested by investigating contributions of FcR γ‐chain, LAT, PLCγ2 and thrombin.

Methods: Thrombi were monitored using intravital microscopy in anesthetized wild‐type and FcR γ‐chain, LAT and PLCγ2 knockout mice. Hirudin (thrombin inhibitor) was administered to wild‐type and FcR γ‐chain knockout mice.

Results: Significantly reduced thrombus formation was observed in FcR γ‐chain and PLCγ2 knockouts with a greater decrease observed in LAT knockouts. Dramatic reduction was observed in wild‐types treated with hirudin, with abolished thrombus formation only observed in FcR γ‐chain knockouts treated with hirudin.

Conclusions: GPVI‐FcR γ‐chain, LAT and PLCγ2 are essential for thrombus generation and stability in this laser‐induced model of injury. More importantly, a greater role for LAT was identified, which may reflect a role for it downstream of a second matrix protein receptor. However, inhibition of platelet activation by matrix proteins and thrombin generation are both required to maximally prevent thrombus formation.
Peritubular Capillary Loss Is Ameliorated by Ramipril or Valsartan Treatment
Authors: Zhang Bin , Chen Nan , Shi Wei , Wang Weiming , Shi Hao , Yu Haijin
Published: May 2008

Objective: To identify the preservation of peritubular capillaries conferred by ramipril or valsartan treatment as an additional mechanism for their renoprotection.

Methods: The effect of ramipril or valsartan on peritubular capillaries was investigated in a remnant kidney model using male Sprague‐Dawley rats sacrificed post‐operatively at 3, 6 and 12 weeks respectively. Peritubular capillaries and tubulointerstitial hypoxia in untreated remnant kidney rats (n = 26), remnant kidney rats treated with ramipril (n = 22, 0.5 mg/kg/day), valsartan (n = 22, 30 mg/kg/day) or amlodipine (n = 22, 30 mg/kg/day) and sham‐operated rats (n = 22) were assessed by CD141 and HIF‐1α staining.

Results: Ramipril or valsartan significantly preserved the peritubular capillaries as well as renal function (p < 0.01). Tubulointerstitial hypoxia and tubular TGF‐β expression were noted well before the development of tubulointerstitial damage. The gentler slope of the relationship between HIF‐1α scores and peritubular capillary density in individual rats was noted in both ramipril‐treated and valsartan‐treated groups compared to the untreated remnant kidney group (p < 0.05).

Conclusions: Amelioration of peritubular capillary loss and subsequent tubular hypoxia by ramipril or valsartan treatment should be interpreted as an alternative type of their renoprotection, one which also implies a novel focus for clinical intervention.
The Origin of the Biphasic Flow Response to Local Heat in Skin
Authors: Widmer R. Jay , Laurinec Jennifer E. , Young Missy F. , Mohiuddin M. Waqar , Laine Glen A. , Quick Christopher M.
Published: May 2008

Objective: Although it is well established that the application of local heat causes a biphasic increase in skin blood flow, the responsible microvessels have not been identified.

Methods: A bifurcating network of arterioles (1st–5th orders, 60–15 μm, n = 10 per group) of the intact, unanesthetized, translucent bat wing were visualized on a transparent heat plate via intravital microscopy. Similar to previous bat wing studies, plate temperature was set at 25°C for 10 min then increased to 37°C for 20 min. Vessel diameter and red blood cell velocity were recorded and used to calculate resistance and blood flow.

Results: The average flow response in arterioles was biphasic (p = 0.02) and proportional to the temporal decrease in total resistance calculated from 1st–5th order arterioles. Metarteriole (i.e., 5th order arteriole) resistance had the greatest impact on total resistance (−67.0 ± 20.7%) and exhibited a biphasic trend that was opposed by temporal changes in resistance of 1st–4th order arterioles.

Conclusion: Metarterioles are not only necessary but sufficient to explain the origin of the biphasic flow response in skin blood flow.
The formin mDia2 stabilizes microtubules independently of its actin nucleation activity
Authors: Bartolini Francesca , Moseley James B. , Schmoranzer Jan , Cassimeris Lynne , Goode Bruce L. , Gundersen Gregg G.
Published: May 2008

A critical microtubule (MT) polarization event in cell migration is the Rho/mDia-dependent stabilization of a subset of MTs oriented toward the direction of migration. Although mDia nucleates actin filaments, it is unclear whether this or a separate activity of mDia underlies MT stabilization. We generated two actin mutants (K853A and I704A) in a constitutively active version of mDia2 containing formin homology domains 1 and 2 (FH1FH2) and found that they still induced stable MTs and bound to the MT TIP proteins EB1 and APC, which have also been implicated in MT stabilization. A dimerization-impaired mutant of mDia2 (W630A) also generated stable MTs in cells. We examined whether FH1FH2mDia2 had direct activity on MTs in vitro and found that it bound directly to MTs, stabilized MTs against cold- and dilution-induced disassembly, and reduced the rates of growth and shortening during MT assembly and disassembly, respectively. These results indicate that mDia2 has a novel MT stabilization activity that is separate from its actin nucleation activity.
Presynaptic Type III Neuregulin1-ErbB signaling targets α7 nicotinic acetylcholine receptors to axons
Authors: Hancock Melissa L. , Canetta Sarah E. , Role Lorna W. , Talmage David A.
Published: May 2008

Type III Neuregulin1 (Nrg1) isoforms are membrane-tethered proteins capable of participating in bidirectional juxtacrine signaling. Neuronal nicotinic acetylcholine receptors (nAChRs), which can modulate the release of a rich array of neurotransmitters, are differentially targeted to presynaptic sites. We demonstrate that Type III Nrg1 back signaling regulates the surface expression of α7 nAChRs along axons of sensory neurons. Stimulation of Type III Nrg1 back signaling induces an increase in axonal surface α7 nAChRs, which results from a redistribution of preexisting intracellular pools of α7 rather than from increased protein synthesis. We also demonstrate that Type III Nrg1 back signaling activates a phosphatidylinositol 3-kinase signaling pathway and that activation of this pathway is required for the insertion of preexisting α7 nAChRs into the axonal plasma membrane. These findings, in conjunction with prior results establishing that Type III Nrg1 back signaling controls gene transcription, demonstrate that Type III Nrg1 back signaling can regulate both short-and long-term changes in neuronal function.
Kindlin-2 (Mig-2): a co-activator of β3 integrins
Authors: Ma Yan-Qing , Qin Jun , Wu Chuanyue , Plow Edward F.
Published: May 2008

Integrin activation is essential for dynamically linking the extracellular environment and cytoskeletal/signaling networks. Activation is controlled by integrins' short cytoplasmic tails (CTs). It is widely accepted that the head domain of talin (talin-H) can mediate integrin activation by binding to two sites in integrin β's CT; in integrin β3 this is an NPLY747 motif and the membrane-proximal region. Here, we show that the C-terminal region of integrin β3 CT, composed of a conserved TS752T region and NITY759 motif, supports integrin activation by binding to a cytosolic binding partner, kindlin-2, a widely distributed PTB domain protein. Co-transfection of kindlin-2 with talin-H results in a synergistic enhancement of integrin αIIbβ3 activation. Furthermore, siRNA knockdown of endogenous kindlin-2 impairs talin-induced αIIbβ3 activation in transfected CHO cells and blunts αvβ3-mediated adhesion and migration of endothelial cells. Our results thus identify kindlin-2 as a novel regulator of integrin activation; it functions as a coactivator.
Aortic Valve Replacement through a Mini Lateral Thoracotomy with High Thoracic Epidural Anesthesia
Authors: Francesco Siclari , Stefanos Demertzis , Romano Mauri , Tiziano Cassina , Giovanni Pedrazzini , Tiziano Moccetti
Published: May 2008

Background

Minimally invasive aortic valve surgery is usually performed through a right parasternal incision or a modification of partial sternotomy. We explored the feasibility of using a videoassisted small right lateral thoracotomy (RLT) to approach the aortic valve.

Methods

From August 2003 to December 2004, 12 patients with aortic stenosis (9) or regurgitation (3) underwent an aortic valve replacement through an 8 cm RLT in the 4th intercostal space. There were 4 men and 8 women with a mean age of 61 years (range 30–79 years). Nine mechanical and 3 biologic prostheses were implanted. Endotracheal narcosis was combined with high thoracic epidural anesthesia. Transesophageal echocardiographic monitoring was performed in all cases. Cannulation was done via the right femoral artery and vein and right jugular vein. The video-assisted operation was performed in moderate hypothermia (30°C) and in cardioplegic arrest. Transthoracic aortic clamping was used in all cases.

Results

Mean operation, perfusion, and clamping times were 223 minutes, 132 minutes, and 73 minutes, respectively. There was no mortality. One patient required conversion to sternotomy due to discovery of a calcium fragment entrapped in a mechanical prosthesis. One patient developed a groin seroma that was treated surgically. All patients, except one were extubated in the operative room and transferred to the intermediate care unit after 6 hours; all had an uneventful recovery.

Conclusions

Aortic valve replacement through an RLT is feasible and safe. Operative time, perfusion, and cross-clamping times are only marginally longer than a conventional operation, and recovery is rapid.
External Reshaping of the Left Ventricle in Off-Pump Surgery
Authors: Prapas Sotirios N. , Protogeros Demetrios A. , Kotsis Vassilios N. , Panagiotopoulos Ioannis A. , Raptis Ioannis P. , Danou Fotini N. , Linardakis Ioannis N. , Karatza Dimitra C. , Anagnostopoulos Constantinos E.
Published: May 2008

Background

Dyskinetic areas of the lateral and inferior left ventricular (LV) wall are frequently encountered in patients with coronary artery disease. In clinical practice, all of the techniques described for the restoration of shape and function of the LV require cardiopulmonary bypass. A new technique of LV external reshaping that aims to obtain a near-normal ventricular conical shape is described. This technique is performed during an off-pump coronary artery bypass graft (CABG) operation. It is used mainly on the inferior and lateral walls of the ventricle, but also on the anterolateral wall when warranted. This technique can be considered an alternative to classic aneurysmectomy in high-risk cases.

Methods

All patients underwent total arterial revascularization without aortic manipulation. Intraoperative transesophageal echocardiography was used in all cases to define the dilated akinetic/dyskinetic area. This area was effectively plicated using interrupted mattress sutures reinforced with Teflon felt or pericardial strips. This technique allows near normalization of the geometry of the ventricle and LV end-diastolic volume reduction. In cases of preexisting mitral regurgitation (MR), a reduction of the MR was observed after lateral wall restoration. From September 2002 to April 2005, the external reshaping technique was applied on 56 cases among 949 off-pump CABG cases (5.9%). A detailed transthoracic echocardiogram was obtained preoperatively. The mean ejection fraction of all enrolled patients was 31.2 ± 7%. The location of the plication was: lateral wall in 22, inferior wall in 16, and anterolateral wall in 18. The average number of coronary anastomoses was 2.6. Twelve patients were found to have 2–3 + MR. All patients were followed up during a period of 35 months.

Results

One patient died due to severe right ventricular dysfunction. Seven patients developed atrial fibrillation, and one had ventricular tachycardia. During the follow-up period, we observed a reduction of left ventricular end-diastolic diameter and a parallel augmentation of ejection fraction (mean 42.2 ± 4%). The ventricular cavity's architecture was normalized. Among the 12 patients with MR, an improvement of regurgitation was noted in 10 (from 2–3+ to 1–2+). One patient died during the follow-up period, and 1 patient required reoperation due to persistent severe MR.

Conclusions

The external reshaping of the LV during beating heart surgery is technically feasible, has promising results, and can be performed without major complications.
Percutaneous Subxiphoid Access to the Epicardium Using a Miniature Crawling Robotic Device
Authors: Ota Takeyoshi , Patronik Nicholas A. , Riviere Cameron N. , Zenati Marco A.
Published: May 2008

Background

To expand minimally invasive beating-heart surgery, we have developed a miniature 2-footed crawling robot (Heart-Lander) that navigates on the epicardium. This paradigm obviates mechanical stabilization and lung deflation, and avoids the access limitations of current approaches. We tested the locomotion of the device on a beating porcine heart accessed through a closed-chest subxiphoid approach.

Methods

HeartLander consists of 2 modules that are connected by an extensible midsection. It adheres to the epicardium using suction pads. Locomotion and turning are accomplished by moving the 2 modules in an alternating fashion using wires that run through the midsection between them. After a preliminary test with a plastic beating-heart model, we performed a porcine study in vivo. The device was inserted into the pericardial space through a subxiphoid incision, while the test was observed using a left thoracoscopy. The blood pressure and electrocardiogram were monitored, and vacuum pressure and driving forces on the wires were recorded.

Results

HeartLander traveled across the anterior and lateral surfaces of the beating heart without restriction, including locomotion forward, backward, and turning. The vacuum pressure was kept below 450 mm Hg at all times. The average maximum force during elongation was 1.86 ± 0.97 N, and during retraction was 1.24 ± 0.33 N. No adverse hemodynamic or electrophysiologic events were noted during the trial. No epicardial damage was found on the excised heart after the porcine trial.

Conclusions

The current HeartLander prototype demonstrated safe and successful locomotion on a beating porcine heart through a closed-chest subxiphoid approach.
Minimally Invasive Surgical Cardiac Resynchronization Therapy: An Intermediate-Term Follow-Up Study
Authors: Corvera Joel S. , Puskas John D. , Thourani Vinod H. , Guyton Robert A. , Lattouf Omar M.
Published: May 2008

Background

Cardiac resynchronization therapy (CRT) improves symptoms, quality of life, and ejection fraction in selected patients with congestive heart failure (CHF) and interventricular conduction delay. Transvenous insertion of left ventricular (LV) pacing leads via the coronary sinus is unsuccessful in 8–10% of patients. This study describes intermediate-term follow up of minimally invasive surgical techniques for CRT as a viable alternative after failed transvenous lead insertion.

Methods

From March 2001 to October 2005, fifty-four patients with NYHA Class III–IV symptoms, QRS duration 181 ± 40 milliseconds, and LV ejection fraction 19.7 ± 8.0% underwent a total of 56 minimally invasive LV lead placements via thoracoscopic video assistance (n = 38) or minithoracotomy (n = 17). One patient required full thoracotomy after a previous video-assisted thoracoscopic procedure. Intraoperative transesophageal echocardiography was used to assess changes in LV function.

Results

Acute thresholds for the active lead measured 1.10 ± 0.62 V, with R-wave amplitude of 12.3 ± 6.6 mV and impedance of 631 ± 185 Ohm. Thirty-day mortality was 5%. There were no perioperative myocardial infarctions or strokes. Five patients required transfusion, 3 had exacerbation of prior renal insufficiency, 5 had pulmonary complications, and 8 required inotropic support for more than 48 hours. Intermediate-term follow up (mean 20 ± 16 months, range 11 days to 55 months) revealed 3 patients with lead failure requiring additional surgical intervention. Hospitalization due to worsening CHF occurred in 5 patients, and 2 of these patients required intravenous inotropic support. QRS duration decreased to 146 ± 36 milliseconds postoperatively (P < 0.001).

Conclusion

Minimally invasive surgical lead placement safely and effectively accomplishes cardiac resynchronization using either thoracoscopic or minithoracotomy techniques.
Hand-Sewn Proximal Anastomoses in Off-Pump Coronary Artery Bypass without the Need for Partial Occlusion Clamping: Experience with the Heartstring II Proximal Seal System
Authors: Schoettle Glenn Phillip , Jones Carol Basham
Published: May 2008

Objective

To evaluate the use of the Heartstring II Proximal Seal System (HPSS) in saphenous vein to aorta anastomoses in off-pump coronary artery bypass (OPCAB).

Methods

The HPSS consists of an aortic cutter and a proximal seal system. A prospective study was done using the HPSS to facilitate proximal hand-sewn anastomoses in OPCAB without partial occlusion clamping. Intraoperative observations, including technical success and post operative clinical data, were recorded.

Results

Using the HPSS, 84 hand-sewn proximal saphenous vein–to–aorta anastomoses were done in 50 patients. In no case was conversion to partial occlusion clamping required. After deployment of the HPSS, operator evaluation showed acceptable hemostasis in 83 of the grafts. One graft required redeployment of a second HPSS. Each bypass graft was evaluated using the Medtronic Medistem Flow Probe. Acceptable flow probe values were present in all grafts, and no revisions were required. The mean length of time for completion of the proximal anastomosis was 5 minutes (range, 4 to 14 minutes). Postoperative clinical evaluation showed no adverse events attributed to the use of the HPSS.

Conclusions

The use of HPSS is a safe and effective method to avoid partial occlusion clamping in hand-sewn proximal anastomoses with OPCAB.
Video-Assisted Thoracic Surgery for Lung Cancer Resection
Authors: Downey Robert J. , Cheng Davy , Kernstine Kemp , Stanbridge Rex , Shennib Hani , Wolf Randall , Ohtsuka Toshiya , Schmid Ralph , Waller David , Fernando Hiran , Yim Anthony , Martin Janet
Published: May 2008

Objective

The purpose of this consensus conference was to determine whether video-assisted thoracic surgery (VATS) improves clinical and resource outcomes compared with conventional thoracotomy (OPEN) in adults undergoing lobectomy for lung cancer, and to outline evidence-based recommendations for the use of VATS in performing lobectomy for lung cancer.

Methods

Before the consensus conference, the best available evidence was reviewed in that systematic reviews, randomized trials, and nonrandomized trials were considered in descending order of validity and importance. At the consensus conference, evidence-based statements were created, and consensus processes were used to determine the ensuing recommendations. The American Heart Association/American College of Cardiology system was used to label the level of evidence and class of recommendation.

Results and Recommendations

The consensus panel agreed upon the following statements and recommendations in patients with clinical stage I nonsmall cell lung cancer undergoing lung lobectomy: 1. VATS can be recommended to reduce overall postoperative complications (class IIa, level A evidence). 2. VATS can be recommended to reduce pain and overall functionality over the short term (class IIa, level B evidence). 3. VATS can be recommended to improve delivery of adjuvant chemotherapy delivery (class IIa, level B evidence). 4. VATS can be recommended for lobectomy in clinical stage I and II non-small cell lung cancer patients, with no proven difference in stage-specific 5-year survival compared with open thoracotomy (class IIb, level B evidence).
Physical Properties of Flexible Polyurethane “Liquid CO2” Slabstock Foaming Mixtures
Authors: Koot Wouter , Maas Wilfried P. M.
Published: May 2008

In commercial slabstock foaming, liquid CO2 technology is increasingly applied to replace previously used liquid auxiliary blowing agents like CFCs and methylene chloride. Knowledge of physical properties of mixtures which are used in liquidCO2 foaming may contribute to the further development of the liquid CO2 technology.

Equations have been determined which do predict, for specific operational conditions and formulations, the pressures which are required in commercial foam operation to keep theCO2 dissolved both in the polyol/CO2 and in the foaming mixture/CO2 solutions. The evident dependence on temperature ofCO2 solubility, established for both polyol and foaming mixtures, strongly supports tight temperature control of the feedstocks in slabstock liquid CO2 foaming.

The solubility of CO2 in polyol was found to increase with the EO content of the polyol where the effect of molecular weight was found to be negligible.

It was established that small amounts of water and surfactant lower the CO2 solubility, and it is predicted that the commonly used levels of TDI do the same. Based on this information, it is advisable to conduct the mixing of TDI and auxiliary components at pressures a fraction higher than the saturation pressure of the liquid CO2 polyol mixture.

A significant decrease of both viscosity and surface tension is quantified for polyol and model foaming systems at increasing liquidCO2 concentration. These decreases may explain why very small cell sizes can be obtained with liquid CO2 foaming, as the nucleation process takes place at high liquid CO2 concentration. The rise in viscosity upon evaporation ofCO2 into the froth may explain the relative stability of the unreacted froth.

A cooling capacity of about 1°C per part of CO2 per hundred parts of polyol is determined from two independent experiments. However, for safety reasons, it is advisable to keep the current assumption of 0°C per part of CO2 per hundred parts of polyol in commercial foaming until a further study on the temperature evolution of liquidCO2 blown foaming under practical conditions is conducted.
The information‐seeking behavior of visual artists: a literature review
Authors: Hemmig William S.
Published: May 2008

Purpose

The purpose of this paper is to examine the literature on the information behavior of practicing visual artists to determine if a consistent model emerges and what further research is necessary.

Design/methodology/approach

Works dealing with the information needs and uses relevant to the creative activities of visual artists are discussed in the paper. These works are assessed for their contributions toward understanding of the specific information behaviors of practicing artists.

Findings

The results show that a consistent model of artists' information behavior emerges. However, nearly all of the literature focuses on art students, academic art faculty, or librarians, and so any claim that practicing artists fit the model is largely unsupported by research. There have been no published studies of communities of practicing visual artists. The implications of defining artists as communities of practice are discussed.

Research limitations/implications

Research is proposed that studies the information behavior of communities of practicing visual artists in order to confirm or amend the existing model.

Practical implications

Practitioners will have their attention drawn to an underserved user population whose information needs and behaviors have not been directly targeted for research. They will recognize the need for study of their own artist communities and the development of services for them.

Originality/value

This paper directs the discussion of artists' information behavior away from the art‐library‐specific literature, where it has largely resided, as a means of adjusting the focus of research onto the largely unstudied and underserved communities of practicing artists.
Information culture: exploration of differing values and attitudes to information in organisations
Authors: Oliver Gillian
Published: May 2008

Purpose

The purpose of this article is to explore the concept of information culture, and to demonstrate its utility when considering information management in organisations.

Design/methodology/approach

Case studies were conducted of organisations with similar functions, located in regions likely to have different cultural dimensions.

Findings

The findings show that different values and attitudes to information are influencing factors of the information culture in the organisations studied.

Practical implications

Knowledge and understanding of the features of information culture will assist with addressing the challenges of organisational information management in this globalised age.

Originality/value

This research adds to the body of knowledge about information culture, in particular national dimensions.
Social field, domains of knowledge and informational practice
Authors: Morado Nascimento Denise , Marteleto Regina Maria
Published: May 2008

Purpose

The purpose of this paper is to understand the information phenomenon through the means of informational practice – the way of acting that gives identity to a group – in a social field and knowledge domain.

Design/methodology/approach

By relating Pierre Bourdieu's sociology of culture to the domain analysis approach of Birger Hjørland, the intention was to achieve a comprehensive interpretation of the structure which generates the discourse communities and, also, of the social structure from which they are derived. All of these form the conditions for understanding the efforts, objectives and interests of the actors in the social field that causes them to develop determined informational practices. The field of architecture was elected for analysis.

Findings

The conclusions show that both the products and subjects of a domain of knowledge, inserted in social fields, are expressions of their informational practice.

Research limitations/implications

The authors believe the theoretical model based on Bourdieu and Hjørland's concepts, here built to analyze the architecture domain, may be used to analyze other domains.

Originality/value

Domain analysis is employed as an approach to the study of the information aspects but here supported by the sociological concepts of Bourdieu. Thus, it is possible to understand what, how and why the informational practices are constituted inside a domain of knowledge, and, fundamentally, interpret the historical, cultural, and social dimensions that influence the construction of information.
Contradictions in the practices of training for and assessment of competency
Authors: Emad Gholamreza , Roth Wolff Michael
Published: May 2008

Purpose

The purpose of this paper is to highlight the contradictions in the current maritime education and training system (MET), which is based on competency‐based education, training and assessment, and to theorize the failure to make the training useful.

Design/methodology/approach

A case study of education and training in the international maritime domain was conducted. Data sources include historical documents, rules and regulations concerning MET, syllabi, handouts, sample questions, field notes, an ethnographic study in a maritime college and interviews conducted with experienced mariners and course lecturer.

Findings

There are contradictions in the education and training system that do not allow the targeted objectives to be fulfilled. Fundamentally, the assessment system has changed the objectives of the education and training practices from learning skills and knowledge required on‐board ships to passing competency examinations.

Practical implications

The practical implication of this research is valuable for the International Maritime Organization, marine administration and maritime training institutes to think over the competency‐based system in practice today and how to improve the present maritime training and assessment system in order to achieve its authentic objectives.

Originality/value

This research identified and bridged the gap in literature and research of competency‐based training and assessment in the maritime domain and provides practical solutions for improving this system.
Mentoring, supervisor support, and perceived organizational support: what matters most?
Authors: Dawley David D. , Andrews Martha C. , Bucklew Neil S.
Published: May 2008

Purpose

The purpose of this paper is to provide an examination of the relative impact of mentoring, supervisor support, and perceived organizational support on organizational commitment and job search behavior.

Design/methodology/approach

In total, 346 employees of a US manufacturing facility were surveyed.

Findings

Ordinary least squared regression model revealed that perceived organizational support was a stronger predictor of organizational commitment and job search behavior than was mentoring and supervisor support.

Research limitations/implications

The main implication of this study for leadership theorists is that while mentors and supervisors can be effective in endearing the employee to the organization, the perception of organizational support might be more important. The main limitation of this study is that the findings are derived from a single manufacturing organization.

Practical implications

The results from this study suggest that organizational leaders must adequately address organizational‐supported programs including fair operating procedures, rewards, and job conditions. These programs underlie perceived organizational support.

Originality/ value of paper

This paper contributes to the literature by providing a concurrent and comparative examination of the effects of mentoring, supervisor support, and perceived organizational support on organizational commitment and job search behavior.
Businesses must face the realities of a low carbon economy
Authors: Alcock Nigel
Published: May 2008

Purpose

The paper aims to look at the need for businesses become energy efficient in order to face the challenges posed by climate change in the light of a government White Paper advocating the reduction of carbon emmisssions.

Design/methodology/approach

The paper looks at research carried out by npower business.

Findings

The paper finds that the benefits of a progressive, long‐term energy management program come not only in cost savings, by reducing consumption and avoiding levies associated with carbon emissions, but in being able to demonstrate an on‐going commitment to carbon reduction and the reputational benefits this brings.

Originality/value

The paper provides interesting information on the need for corporate energy management.
Lament of the ignored expatriate
Authors: Hutchings Kate , French Erica , Hatcher Tim
Published: May 2008

Purpose

The purpose of this paper is to investigate the relationship between gender and the individual and social aspects of expatriate work, emphasising how issues external to the organisation impact on the experience of female expatriates.

Design/methodology/approach

In total, 102 male respondents and 44 female respondents were surveyed in order to test the perceived organisational support, career satisfaction, and expatriate social support.

Findings

Significant gender‐related differences were identified in all three areas with notable contradiction in the perception and practice of how multinational corporations (MNCs) manage their expatriates. While earlier research suggested that organisations perceived their treatment of female expatriates to be equivalent to that of men, the results indicate that female international managers do not perceive equal treatment on international assignments.

Research limitations/implications

Although based on a smaller sample than other international studies, the gender breakdown was sufficient for moderated regression testing.

Practical implications

As the expatriate social support construct is largely exploratory in nature, future research could examine the effect of perceived expatriate social support on other related workplace behaviours, both domestically and internationally, including work‐life balance and diversity management.

Originality/value

While other studies have provided a rich descriptive picture of the gendered nature of expatriation, little research has attempted to quantify the reasons behind the phenomenon. This paper addresses this gap in the literature through exploration of the issues, which impact upon the experience of female expatriates in foreign MNCs in China.
Security aspects of mobile phone virus: a critical survey
Authors: Shih Dong‐Her , Lin Binshan , Chiang Hsiu‐Sen , Shih Ming‐Hung
Published: May 2008

Purpose

The paper's aim is to provide information about mobile viruses for end‐users or organizations and recommend useful tips of how individuals can protect their mobile phones from the intrusion of mobile phone viruses.

Design/methodology/approach

This paper surveys chronicle, securities, risks and countermeasure of mobile phone viruses.

Findings

This paper investigates infection routes, threats, damage, and spreading ways of mobile phone viruses and provides available countermeasures. It also provides useful tips about mobile viruses, indicating what to do and how to do it.

Research limitations/implications

This research may not be exhaustive about mobile viruses.

Practical implications

A very useful source of information and impartial advice for end‐users or organizations who are planning to protect their mobile phones and their own privacy.

Originality/value

This paper is the first to survey the risk of mobile phones and it discusses how organizations or individuals can protect mobile phones from the intrusion of viruses and how to develop their own mobile virus security plan.