bluuebunny/crossref_metadata_2025 huggingface dataset:
Improved exercise performance in pediatric heart transplant recipients after home exercise training
Authors: Patel Jatin N. , Kavey Rae‐Ellen , Pophal Stephen G. , Trapp Erin E. , Jellen Gina , Pahl Elfriede
Published: April 2008

Abstract:  Pediatric heart transplant recipients have been shown to have reduced exercise performance. Studies of adult heart transplant recipients demonstrate improved endurance from regular aerobic exercise; however, this strategy has not been studied in children. We hypothesized that regular aerobic/strength training would improve exercise performance in children post‐heart transplant. After an initial training session, an exercise protocol was performed at home for 12 wk, three days/wk. Aerobic exercise consisted of either running or use of an exercise bicycle to an established target HR for ≥20 min of a 30‐min session for three days/wk. Subjects wore a HR monitor and kept a diary to monitor compliance. Two days/wk, strength training was performed with elastic bands to specifically exercise biceps and triceps groups for 15–20 min/session. Aerobic exercise capacity was assessed at baseline and post‐training using the standard Bruce treadmill protocol. Strength was measured at baseline and post‐intervention by dynamometer. Exercise and strength parameters at baseline and post‐intervention were compared using paired student t‐tests. Eleven subjects completed the 12‐wk program, eight females and three males. The mean age at enrollment was 14.7 ± 5.3 yr (8–25) and mean time from transplant was 5.26 ± 5.34 yr (0.58–14.71). Endurance time and peak oxygen consumption improved significantly post‐exercise; there was no difference in peak HR or systolic blood pressure. Strength improved in the triceps, quadriceps, and biceps groups. After a 12‐wk inhome exercise intervention, pediatric heart recipients had improved exercise endurance and strength. The protocol was safe and implemented at relatively low cost. Further study is warranted to determine if the intervention can be extended to more children and whether benefits after such a short‐term intervention can be sustained.
Two cases of Norwalk virus enteritis following small bowel transplantation treated with oral human serum immunoglobulin
Authors: Florescu Diana F. , Hill Lisa A. , McCartan Megan A. , Grant Wendy
Published: April 2008

Abstract:  Protracted diarrhea is a challenging problem after small bowel transplantation. We report two patients who developed Norwalk virus enteritis after small bowel transplantation. Both received oral HSIG with resolution of diarrhea within 48 h.
Perceived barriers to adherence among adolescent renal transplant candidates
Authors: Zelikovsky Nataliya , Schast Aileen P. , Palmer JoAnn , Meyers Kevin E.C.
Published: April 2008

Abstract:  Non‐adherence to medical regimens is a ubiquitous hindrance to quality health care among adolescent transplant recipients. Identification of potentially modifiable barriers to adherence when patients are listed for organ transplant would help with early intervention efforts to prepare adolescents for the stringent medication regimen post‐transplant. Fifty‐six adolescents listed for a kidney transplant, mean age 14.27 (s.d. = 2.2; range 11–18 yr), 73.2% male, 62.5% Caucasian participated in a semi‐structured interview, the Medical Adherence Measure, to assesses the patient’s knowledge of the prescribed regimen, reported adherence (missed and late doses), the system used to organized medications, and who holds the primary responsibility over medication management. Better knowledge of the medication regimen was associated with fewer missed doses (r = −0.48, p < 0.001). Patients who perceived more barriers had more missed (r = 0.38, p = 0.004) and late (r = 0.47, p < 0.001) doses. Patients who endorsed “just forget,” the most common barrier (56.4%), reported significantly more missed (z = −4.25, p < 0.001) and late (z = −2.2, p = 0.02) doses. Only one‐third of the transplant candidates used a pillbox to organize medications but these patients had significantly better adherence, z = −2.2, p = 0.03. With regard to responsibility over managing the regimens, adolescents missed fewer doses when their parents were in charge than when they were solely responsible, z = −2.1, p = 0.04. Interventions developed to prepare transplant candidates for a stringent post‐transplant regimen need to focus on ensuring accurate knowledge of as simple a regimen as possible. Use of an organized system such as a pillbox to establish a routine and facilitate tracking of medications is recommended with integration of reminders that may be appealing for this age group. Although individuation is developmentally normative at this age, parent involvement seems critical until the adolescent is able to manage the responsibility more independently.
Environmentally induced changes in carotenoid‐based coloration of female lizards: a comment on Vercken et al.
Authors: COTE J. , LE GALLIARD J.‐F. , ROSSI J.‐M. , FITZE P. S.
Published: April 2008

Colouration may either reflect a discrete polymorphism potentially related to life‐history strategies, a continuous signal related to individual quality or a combination of both. Recently, Vercken et al. [J. Evol. Biol. (2007) 221] proposed three discrete ventral colour morphs in female common lizards, Lacerta vivipara, and suggested that they reflect alternative reproductive strategies. Here, we provide a quantitative assessment of the phenotypic distribution and determinants of the proposed colour polymorphism. Based on reflectance spectra, we found no evidence for three distinct visual colour classes, but observed continuous variation in colour from pale yellow to orange. Based on a 2‐year experiment, we also provide evidence for reversible colour plasticity in response to a manipulation of the adult population sex ratio; yet, a significant portion of the colour variation was invariant throughout an adult female’s life. Our results are thus in agreement with continuous colour variation in adults determined by environmental factors and potentially also by genetic factors.
Off‐label use of recombinant factor VIIa for treatment of haemorrhage: results from randomized clinical trials
Authors: Johansson P. I.
Published: April 2008

Background  Recombinant factor VIIa (rFVIIa) is used for haemophilic patients with inhibitors against coagulation factor VIII or IX, but there is also an off‐label use of rFVIIa for patients with massive bleeding. The aim of the present study was to review the randomized clinical trials (RCT) for evidence of such an approach.

Methods  In October 2007, a review of RCT involving rFVIIa for non‐haemophilic indications was performed. The effect of rFVIIa on blood loss and transfusion requirements was recorded.

Results  Seventeen RCTs were identified concerning different bleeding conditions, for example, secondary to surgery, infection and stem cell transplantation. Three pilot studies reported a significant reduction in transfusion requirements and/or blood loss in the rFVIIa‐treated groups, but these have not been confirmed in large randomized trials. No difference in thromboembolic complications between rFVIIa and placebotreated patients were found, except for a study in patients with intracranial haemorrhage. In the intracranial haemorrhage study, 16 out of 16 arterial thrombotic events and 19 out of 21 combined arterial and venous thromboembolic events were found in the rFVIIa‐treated patients.

Conclusion  There is little evidence to support routine use of rFVIIa for patients with massive bleeding based on the results of the randomized trials performed. In patients with a normal haemostatic system, administration of rFVIIa may be associated with an increased risk of thromboembolic events.
Altered mating behaviour in a Cry1Ac‐resistant strain of Helicoverpa armigera (Lepidoptera: Noctuidae)
Authors: Zhao X. C. , Wu K. M. , Liang G. M. , Guo Y. Y.
Published: April 2008

Randomness of mating between susceptible and resistant individuals is a major factor that closely relates to the refuge strategy of resistance management for Helicoverpa armigera (Hübner) to Bacillus thuringiensis cotton. The mating behaviour of Cry1Ac‐susceptible and Cry1Ac‐resistant strains of H. armigera was compared to investigate the randomness of their mating. The percentage of mating was lower for Cry1Ac‐resistant H. armigera compared with that of the susceptible strain under both no‐choice and multiple‐choice conditions. The low percentage of mating in the resistant strain indicates a reduced incidence of successful mating. The percentage of spermatophore‐containing mated female H. armigera in the crossing of susceptible females × resistant males was significantly lower than in the crossing of resistant females × susceptible males, but the observed mating frequencies of these two types of cross were similar to each other. This indicates that resistant males reduce the incidence of mating paternity more than they do their mating frequency. The percentages of heterogametic matings (susceptible females × resistant males, resistant females × susceptible males) in the multiple‐choice experiment were lower than those of homogametic matings (susceptible × susceptible, resistant × resistant) on peak mating nights. However, the difference between heterogametic and homogametic mating was not significant, indicating that there was a random mating between susceptible and resistant strains. The results presented here do not reflect reality in mating associated with Cry1Ac resistance but can provide insight into variable expression.
Parasitization of beet leafhopper eggs, Circulifer tenellus, in California
Authors: Bayoun I. M. , Walker G. P. , Triapitsyn S. V.
Published: April 2008

Parasitoids attacking eggs of beet leafhopper, Circulifer tenellus (Baker) (Hemiptera: Cicadellidae), were surveyed at eight sites in southern and central California for 2 years. One site was an insecticide‐free sugar beet field, and the remaining sites were all uncultivated and supported weedy vegetation. At each site, host plants of beet leafhopper were collected and stored until parasitoids emerged from the leafhopper eggs in the vegetation. Vegetation samples included both naturally occurring host plants and sugar beet outplants that were first infested with beet leafhopper eggs in the laboratory and then placed in the field for 2 days. Parasitism generally was highest in summer and lowest in winter. Beet leafhopper eggs were parasitized by the mymarids (Hymenoptera: Mymaridae) Anagrus nigriventris Girault, Polynema eutettexi Girault, P. longipes (Ashmead), Polynema sp., Gonatocerus capitatus Gahan and two Gonatocerus spp. from the litoralis species group, and the trichogrammatids (Hymenoptera: Trichogrammatidae) Aphelinoidea zarehi Triapitsyn, Walker and Bayoun, A. turanica Trjapitzin, A. roja Triapitsyn, Walker and Bayoun, A. anatolica Nowicki and Paracentrobia sp. near P. subflava (Girault). The most dominant were A. nigriventris, A. zarehi and Paracentrobia sp. The intensity of parasitism varied greatly among the sites with peak levels ranging from 13% to 82%. Species composition also varied among sites, especially between the sugar beet field where A. nigriventris was by far the most dominant parasitoid and the uncultivated sites where A. zarehi and/or Paracentrobia sp. usually dominated. Within the uncultivated sites, parasitoid species composition also varied between the sugar beet outplants and the naturally occurring vegetation; A. nigriventris was much more common in the former than in the latter.
Approaching risk assessment of complex disease development in horse chestnut trees: a chemical ecologist’s perspective
Authors: Johne A. B. , Weissbecker B. , Schütz S.
Published: April 2008

Abstract The chemo‐ecological predispositions were investigated for the development of a complex disease on the basis of an insect–fungus mutualism using the system of horse chestnuts (Aesculus hippocastanum and Aesculus x carnea), the horse chestnut leaf miner (Cameraria ohridella) and the biotrophic powdery mildew (Erysiphe flexuosa). Both C. ohridella and E. flexuosa can appear on the same horse chestnut leaf tissue simultaneously. The olfactory detection of fungal infection by the insect, its ability to discriminate the potentially mutualistic fungus from other fungi and the impact of fungal infection on insect oviposition were examined. Gas chromatography coupled with mass spectroscopic and electroantennographic detection by C. ohridella (GC‐MS/EAD) was used to assess the olfactory detection of fungal‐infected A. hippocastanum and A. x carnea leaves by C. ohridella. Infection‐related compounds, such as benzyl alcohol, dodecane, tridecane and methyl salicylate as well as fungus‐related C8 compounds, are perceived by C. ohridella. The discrimination of E. flexuosa from another phytopathogenic fungus, such as Guignardia aesculi, is based primarily on the differing pattern of C8 compounds of these fungi. Oviposition on fungal‐infected leaves of A. hippocastanum and leaves treated with fungal‐related compounds showed that C. ohridella is able to respond to the modifications in the leaf volatile profiles of horse chestnuts caused by the different fungal infections. Thus, from the perception point of view, the necessary predispositions for the development of a close insect–fungus relation between the biotrophic fungus E. flexuosa and the leaf‐mining insect C. ohridella are fulfilled. However, decreased oviposition on infected leaves does not enhance the selective contact between the species. As a consequence, an important predisposition for forming an insect–fungus mutualism is not fulfilled by these two species and, according to this approach, the risk of forming a complex disease can be assessed as low.
Effects of irradiation dose rate on quality and sterility of Queensland fruit flies, Bactrocera tryoni (Froggatt)
Authors: Collins S. R. , Weldon C. W. , Banos C. , Taylor P. W.
Published: April 2008

Queensland fruit fly (Bactrocera tryoni; Q‐fly) pupae are routinely irradiated to induce reproductive sterility in adults released in a sterile insect technique programme. Although there have been some studies of how total dose influences fly quality, dose rate has not been considered. In the present study, pupae were irradiated at a target dose range of 70–75 Gy at dose rates of approximately 5, 7, 26, 57 and 80 Gy/min and were then subjected to routine IAEA/FAO/USDA quality control tests including emergence, flight ability, mortality under stress and sterility induction. No significant effects of dose rate were found on emergence or flight ability. Sterility induction was also found to be independent of dose rate, a result conforming to a ‘one‐hit’ ionizing event hypothesis. Flies irradiated at higher dose rates suffered increased mortality under stress. This appears to stem from an increased tendency to over‐shoot the target dose when irradiating at high dose rates. We recommend that, to reduce potential error in total target dose, the lowest practical dose rate be used when irradiating Q‐fly pupae for use in the sterile insect technique.
Distribution and eradication of an exotic tephritid fruit fly in Australia: relevance of invasion theory
Authors: Meats A. , Fay H. A. C. , Drew R. A. I.
Published: April 2008

Data from the eradication of the incursion of Bactrocera papayae Drew and Hancock (Dipt.: Tephritidae) in Australia (1995–1998) are used to assess the significance of various aspects of invasion theory, including the influence of towns on establishment, influence of propagule pressure on the pattern of establishment, and the existence of source‐sink dynamics. Because there were no sentinel traps in place, considerable spread had occurred before the eradication campaign started. The distribution of fly density around the epicentre in the town of Cairns and a transect along the main traffic routes to the north and south fitted a Cauchy model with a tail having the same slope as a power model with an exponent of −2.4 extending to 160 km. The Cauchy model indicated that 50% of the flies on the transect would have occurred within 3.2 km of the epicentre, 90% within 13.2 km, and 99% within 60 km. The two major satellites at Mareeba (35 km from the epicentre in Cairns) and Mossman (65 km) were not used for the transect data and had respectively 15 and 30 times the density predicted by the model. The proportion of traps that caught flies (a measure of site occupancy) fell with distance from the epicentre. B. papayae was trapped consistently on only three of the 16 rainforest transects that were surveyed and these were relatively close to urban areas where eradication efforts were intense. Despite there being no eradication effort in the rainforest, the trends to extinction were similar to those in adjacent areas. The strategy of initially concentrating eradication efforts on the core and major satellites while maintaining a quarantine barrier at the airport and the boundaries of the infested area appears to be the key to the containment and rapid eradication of the incursion.
QTL analysis for resistance to preharvest sprouting in rice (Oryza sativa)
Authors: Gao F. Y. , Ren G. J. , Lu X. J. , Sun S. X. , Li H. J. , Gao Y. M. , Luo H. , Yan W. G. , Zhang Y. Z.
Published: April 2008

Preharvest sprouting (PHS) is caused by early breaking of seed dormancy. In Sichuan, a major hybrid rice seed production area of China, PHS in hybrid seeds originated from ‘G46A’ parent may lead to severe yield loss, causing serious damage to agricultural production. To detect quantitative trait loci (QTLs) governing PHS, we developed an F2 population of 164 plants derived from ‘G46B’ and ‘K81’, a near‐isogenic introgression line of G46B, with high level of resistance to PHS. PHS was evaluated under controlled field and laboratory conditions. Using simple sequence repeat markers, we constructed a linkage map from this population and identified three QTLs for PHS, namely qPSR2, qPSR5 and qPSR8, which were located on chromosomes 2, 5 and 8, respectively. Among these QTLs, qPSR8, residing in the interval between RM447 and RM3754 on chromosome 8, was the major QTL controlling PHS, for it had a relative high logarithm of the odds (LOD) score and explained 43.04% of the phenotypic variation. These results were correspondent to those identified in extreme low germination rate plants (ELGP) using linkage and linkage disequilibrium. At all loci, ‘K81’ was responsible for enhancing the resistance to PHS.
Modulation of matrix metalloproteinases by ultraviolet radiation in the canine cornea
Authors: Chandler Heather L. , Kusewitt Donna F. , Colitz Carmen M. H.
Published: April 2008

Purpose  To determine whether ultraviolet (UV) radiation can modulate expression and regulation of matrix metalloproteinases (MMP) in the canine cornea and to examine the expression of MMPs in canine chronic superficial keratitis (CSK).

Methods  Immunohistochemistry for MMP‐2 and MMP‐9 was performed on samples of CSK. In vitro, canine corneal epithelial cell (CEC) and stromal cell cultures were exposed to UV‐irradiation. Following 2, 8 or 24 h, cells were harvested. MMP expression was examined by zymography, and RT‐PCR was used to examine expression of Slug and Snail. CEC cultures treated with an EGFR inhibitor or a p38 inhibitor were UV‐exposed and harvested 24 h later to examine expression of MMPs, Slug and Snail.

Results  Canine CSK had increased immunopositivity for both MMP‐2 and MMP‐9 compared to normal canine corneas. In vitro, CEC and stromal cell cultures exposed to UV showed generally increased expression of MMP‐2, ‐9, Slug, and Snail; this response was dose and time dependent. Inhibition of the EGFR pathway did not prevent increased expression of MMP‐2, ‐9, Slug or Snail in UV‐exposed CEC; however, p38 inhibition did attenuate UV induction.

Conclusions  We have found increased expression of MMPs in clinical samples of CSK compared to normal corneas. In addition, we have shown that there is a temporal association and dose dependency between UV exposure and production of MMPs, Slug, and Snail. These findings suggest that overexpression of MMPs due to UV‐exposure may be linked to changes in the cornea that allow an influx of inflammatory cells and vascularization.
The effect of a single dose of topical 0.005% latanoprost and 2% dorzolamide/0.5% timolol combination on the blood‐aqueous barrier in dogs: a pilot study
Authors: Johnstone McLean Nancy S. , Ward Daniel A. , Hendrix Diane V. H.
Published: April 2008

Objective To determine the effects of 0.005% latanoprost and 2% dorzolamide/0.5% timolol on the blood‐aqueous barrier (BAB) in normal dogs.

Animals studied Eight mixed‐breed and pure‐breed dogs.

Procedures Baseline anterior chamber fluorophotometry was performed on eight normal dogs. Sodium fluorescein was injected and the dogs were scanned 60–90 min post‐injection. Seventy‐two hours following the baseline scan, one eye received one drop of latanoprost. Fluorophotometry was repeated 4 h after drug administration. Following a washout period, the identical procedure was performed 4 h after the administration of dorzolamide/timolol. The degree of BAB breakdown was determined by comparing the concentrations of fluorescein within the anterior chamber before and after drug administration. BAB breakdown was expressed as a percentage increase in the post‐treatment fluorescein concentration over the baseline concentration: %INC [Fl] = {([Fl]post – [Fl]baseline)/[Fl]baseline} × 100. The percentage increase in fluorescein concentration in the treated eye was compared to that in the nontreated eye using a pairedt‐test with significance set atP ≤ 0.05.

Results Following administration of latanoprost, the fluorescein in the treated eyes increased 49% (± 58%) from baseline compared to 10% (± 31%) in the untreated eyes (P = 0.016). Following administration of dorzolamide/timolol, the fluorescein concentration increased 38% (± 54%) compared to baseline vs. 24% (± 38%) in the untreated eyes (P = 0.22).

Conclusions The results of this study show that topical latanoprost may cause BAB disruption in normal dogs while topical dorzolamide/timolol may have no effect on the BAB in normal dogs.
Feline primary open angle glaucoma
Authors: Jacobi Susan , Dubielzig Richard R.
Published: April 2008

Objectives  We have documented the histomorphological features of feline primary open angle glaucoma.

Design  A retrospective morphologic study of eight affected eyes from eight cats, from 1992 to 2006 extracted from a pathology collection, which includes 4000 feline submissions and 1100 cases of feline glaucoma.

Procedure  Sections of affected globes, stained with H&E or with alcian blue were examined with a light microscope. Eyes that did not fulfill the criteria for primary open angle glaucoma were excluded from the study.

Results  The mean age was 9.1 years. Five cats were female and three cats were male. The breeds included five DSH, two Burmese, and one DLH cat. Significant histomorphological findings included an open irido‐corneal angle with an open ciliary cleft in all cases, loss of ganglion cells in eight of eight cases, cupping and gliosis of the optic nerve head in four of four cases in which the optic nerve was adequately sampled, and myxomatous changes of the stroma surrounding the vortex veins in seven of eight cases.

Conclusions  Primary open angle glaucoma in cats is a rare disease that should be taken into consideration when investigating cases of feline glaucoma. The pathogenesis of aqueous outflow obstruction in these cases is not known. This study describes eight additional cases of feline primary open angle glaucoma in cats without an identified cause.
Does the current World Health Organization classification predict the outcome better in patients with noninvasive bladder cancer of early or regular onset?
Authors: Burger Maximilian , Denzinger Stefan , Wieland Wolf‐Ferdinand , Stief Christian G. , Hartmann Arndt , Zaak Dirk
Published: April 2008

OBJECTIVE

To compare the clinical outcome and prognostic power of the former and current World Health Organization (WHO) grading system in patients with early vs regular onset of noninvasive urothelial bladder cancer (UBC), as little is known of the natural history of early onset UBC and in how far it is reflected by histopathological grading and staging in guiding clinical decisions.

PATIENTS AND METHODS

The medical records of 69 consecutive patients presenting with initial UBC of early onset (≥45 years old, EO) and of 100 randomly chosen patients with regular onset (RO) were reviewed. There were no significant differences in gender distribution, risk factors or tumour stage. All histopathological specimens were re‐staged and re‐graded according to the former and current WHO grading.

RESULTS

In all, 51 EO and 63 RO patients with tumours staged pTa and complete follow‐up information were analysed. Recurrence‐free survival (RFS) was prolonged in patients with EO. In EO neither the former nor the current WHO grading system was significantly related to RFS or to progression to muscle‐invasive disease. In RO, while both WHO grading systems were significantly related to RFS, only the current WHO grading system was related to progression.

CONCLUSION

While larger studies are needed, UBC in patients with EO and RO do not seem to differ in risk factors and oncological outcome. The current WHO classification reflects the outcome more accurately than the former classification in patients with RO. However, for EO no grading system has sufficient prognostic power and novel methods, i.e. molecular markers, need to be evaluated for clinical use.
Kidneys from patients with small renal tumours: a novel source of kidneys for transplantation
Authors: Nicol David L. , Preston John M. , Wall Daryl R. , Griffin Anthony D. , Campbell Scott B. , Isbel Nicole M. , Hawley Carmel M. , Johnson David W.
Published: April 2008

OBJECTIVE

To report the use of a novel donor source as a further option to increase the number of patients who might be able to receive a renal transplant.

PATIENTS AND METHODS

Between May 1996 and July 2007, 43 kidneys were transplanted using kidneys obtained from patients with small (<3 cm diameter) incidentally detected tumours. After bench surgery to excise the tumour, they were all successfully transplanted into patients who were elderly or had significant comorbidities.

RESULTS

Apart from four patients who died from unrelated illnesses, all grafts continued to function with a median and mean follow‐up of 25 and 32 months. The follow‐up, which included 3‐monthly renal ultrasonography and chest X‐rays, showed only one case of tumour recurrence, which occurred 9 years after transplantation; the patient remains stable under observation after 18 months.

CONCLUSIONS

From our experience we consider that where nephrectomy is used for small, localized, incidentally detected renal tumours, the kidney should be considered for transplantation into carefully selected patients. Such patients with numerous medical comorbidities might benefit from renal transplantation, but not survive the waiting period if they are dependent on a deceased donor graft. Paradoxically the use of these marginal kidneys has the potential to increase the quality and length of life of these patients, despite the apparent contradiction of an intuitive principle of organ transplantation and immunosuppression.
An assessment of urologists’ training and knowledge of energy‐based surgical devices
Authors: Lehman Daniel S. , Phillips Courtney K. , Hruby Gregory W. , Lambert Sarah , Landman Jaime
Published: April 2008

OBJECTIVE

To assess surgeons’ training and current understanding of existing energy‐based surgical instrumentation (ESI), we disseminated an online questionnaire to urology residents, fellows and attending urologists.

SUBJECTS AND METHODS

A two part 24‐question survey was disseminated to 1000 urology residents, fellows and attending physicians. The first part of the questionnaire assessed the respondents’ demographics and education about ESI; the second part evaluated the respondent’s knowledge of surgical energy methods and ESI, and was stratified into nine basic‐ and six advanced‐knowledge questions.

RESULTS

In all, 136 people (13.6%) viewed the survey and it was completed by 63 (6.3%). Respondents comprised 27 (43%) attending physicians, 14 (22%) minimally‐invasive urology fellows and 22 (35%) urology residents. Among participants, 41 (64%) had received no formal didactic training on ESI, and a further 14% of respondents’ didactic experience was limited to one lecture. Of the respondents, 70% said that monopolar energy was the mode most often used in surgery. Overall, the participants correctly answered 41% of the questions. Of the nine questions classified as ‘basic’ knowledge, respondents correctly answered 49%. Of the six questions classified as ‘advanced’ knowledge, 29% were answered correctly. The highest percentage score was obtained by the attending urologists, with a mean (range) score of 41 (29–86)%, followed by the fellows, with a mean score of 39.5 (29–57)%, and then the residents, at 34 (14–64)%.

CONCLUSION

Despite widespread and growing use of ESI, there is currently minimal formal training on energy modes and current energy devices being provided to urological surgeons. Both practising and training urologists have a limited understanding of surgical energy modes and of existing ESI.
PATERNALISM AND FAIRNESS IN CLINICAL RESEARCH
Authors: JANSEN LYNN A. , WALL STEVEN
Published: April 2008

In this paper, we defend the ethics of clinical research against the charge of paternalism. We do so not by denying that the ethics of clinical research is paternalistic, but rather by defending the legitimacy of paternalism in this context. Our aim is not to defend any particular set of paternalistic restrictions, but rather to make a general case for the permissibility of paternalistic restrictions in this context. Specifically, we argue that there is no basic liberty‐right to participate in clinical research and that considerations of distributive fairness justify some paternalistic protections of research subjects.
Render2MPEG: A Perception‐based Framework Towards Integrating Rendering and Video Compression
Authors: Herzog Robert , Kinuwaki Shinichi , Myszkowski Karol , Seidel Hans‐Peter
Published: April 2008

Currently 3D animation rendering and video compression are completely independent processes even if rendered frames are streamed on‐the‐fly within a client‐server platform. In such scenario, which may involve time‐varying transmission bandwidths and different display characteristics at the client side, dynamic adjustment of the rendering quality to such requirements can lead to a better use of server resources. In this work, we present a framework where the renderer and MPEG codec are coupled through a straightforward interface that provides precise motion vectors from the rendering side to the codec and perceptual error thresholds for each pixel in the opposite direction. The perceptual error thresholds take into account bandwidth‐dependent quantization errors resulting from the lossy com‐pression as well as image content‐dependent luminance and spatial contrast masking. The availability of the discrete cosine transform (DCT) coefficients at the codec side enables to use advanced models of the human visual system (HVS) in the perceptual error threshold derivation without incurring any significant cost. Those error thresholds are then used to control the rendering quality and make it well aligned with the compressed stream quality. In our prototype system we use the lightcuts technique developed by Walter et al., which we enhance to handle dynamic image sequences, and an MPEG‐2 implementation. Our results clearly demonstrate many advantages of coupling the rendering with video compression in terms of faster rendering. Furthermore, temporally coherent rendering leads to a reduction of temporal artifacts.
Curvature‐Domain Shape Processing
Authors: Eigensatz Michael , Sumner Robert W. , Pauly Mark
Published: April 2008

We propose a framework for 3D geometry processing that provides direct access to surface curvature to facilitate advanced shape editing, filtering, and synthesis algorithms. The central idea is to map a given surface to the curvature domain by evaluating its principle curvatures, apply filtering and editing operations to the curvature distribution, and reconstruct the resulting surface using an optimization approach. Our system allows the user to prescribe arbitrary principle curvature values anywhere on the surface. The optimization solves a nonlinear least‐squares problem to find the surface that best matches the desired target curvatures while preserving important properties of the original shape. We demonstrate the effectiveness of this processing metaphor with several applications, including anisotropic smoothing, feature enhancement, and multi‐scale curvature editing.
Spectral Geometry Processing with Manifold Harmonics
Authors: Vallet B. , Lévy B.
Published: April 2008

We present an explicit method to compute a generalization of the Fourier Transform on a mesh. It is well known that the eigenfunctions of the Laplace Beltrami operator (Manifold Harmonics) define a function basis allowing for such a transform. However, computing even just a few eigenvectors is out of reach for meshes with more than a few thousand vertices, and storing these eigenvectors is prohibitive for large meshes. To overcome these limitations, we propose a band‐by‐band spectrum computation algorithm and an out‐of‐core implementation that can compute thousands of eigenvectors for meshes with up to a million vertices. We also propose a limited‐memory filtering algorithm, that does not need to store the eigenvectors. Using this latter algorithm, specific frequency bands can be filtered, without needing to compute the entire spectrum. Finally, we demonstrate some applications of our method to interactive convolution geometry filtering. These technical achievements are supported by a solid yet simple theoretic framework based on Discrete Exterior Calculus (DEC). In particular, the issues of symmetry and discretization of the operator are considered with great care.
Real‐Time Rendering and Editing of Vector‐based Terrains
Authors: Bruneton Eric , Neyret Fabrice
Published: April 2008

We present a method to populate very large terrains with very detailed features such as roads, rivers, lakes and fields. These features can be interactively edited, and the landscape can be explored in real time at any altitude from flight view to car view. We use vector descriptions of linear and areal features, with associated shaders to specify their appearance (terrain color and material), their footprint (effect on terrain shape), and their associated objects (bridges, hedges, etc.).

In order to encompass both very large terrains and very fine details we rely on a view dependent quadtree refinement scheme. New quads are generated when needed and cached on the GPU. For each quad we produce on the GPU an appearance texture, a footprint texture, and some object meshes, based on the features vector description and their associated shaders. Adaptive refinement, procedural vector features and a mipmap pyramid provide three LOD mechanisms for small, medium and large scale quads. Our results and attached video show high performance with high visual quality.
Simulation of Human Motion Data using Short‐Horizon Model‐Predictive Control
Authors: Da Silva M. , Abe Y. , Popović J.
Published: April 2008

Many data‐driven animation techniques are capable of producing high quality motions of human characters. Few techniques, however, are capable of generating motions that are consistent with physically simulated environments. Physically simulated characters, in contrast, are automatically consistent with the environment, but their motions are often unnatural because they are difficult to control. We present a model‐predictive controller that yields natural motions by guiding simulated humans toward real motion data. During simulation, the predictive component of the controller solves a quadratic program to compute the forces for a short window of time into the future. These forces are then applied by a low‐gain proportional‐derivative component, which makes minor adjustments until the next planning cycle. The controller is fast enough for interactive systems such as games and training simulations. It requires no precomputation and little manual tuning. The controller is resilient to mismatches between the character dynamics and the input motion, which allows it to track motion capture data even where the real dynamics are not known precisely. The same principled formulation can generate natural walks, runs, and jumps in a number of different physically simulated surroundings.
Automatic Conversion of Mesh Animations into Skeleton‐based Animations
Authors: De Aguiar Edilson , Theobalt Christian , Thrun Sebastian , Seidel Hans‐Peter
Published: April 2008

Recently, it has become increasingly popular to represent animations not by means of a classical skeleton‐based model, but in the form of deforming mesh sequences. The reason for this new trend is that novel mesh deformation methods as well as new surface based scene capture techniques offer a great level of flexibility during animation creation. Unfortunately, the resulting scene representation is less compact than skeletal ones and there is not yet a rich toolbox available which enables easy post‐processing and modification of mesh animations. To bridge this gap between the mesh‐based and the skeletal paradigm, we propose a new method that automatically extracts a plausible kinematic skeleton, skeletal motion parameters, as well as surface skinning weights from arbitrary mesh animations. By this means, deforming mesh sequences can be fully‐automatically transformed into fullyrigged virtual subjects. The original input can then be quickly rendered based on the new compact bone and skin representation, and it can be easily modified using the full repertoire of already existing animation tools.
Articulated Object Reconstruction and Markerless Motion Capture from Depth Video
Authors: Pekelny Yuri , Gotsman Craig
Published: April 2008

We present an algorithm for acquiring the 3D surface geometry and motion of a dynamic piecewise‐rigid object using a single depth video camera. The algorithm identifies and tracks the rigid components in each frame, while accumulating the geometric information acquired over time, possibly from different viewpoints. The algorithm also reconstructs the dynamic skeleton of the object, thus can be used for markerless motion capture. The acquired model can then be animated to novel poses. We show the results of the algorithm applied to synthetic and real depth video.
Higher Order Barycentric Coordinates
Authors: Langer Torsten , Seidel Hans‐Peter
Published: April 2008

In recent years, a wide range of generalized barycentric coordinates has been suggested. However, all of them lack control over derivatives. We show how the notion of barycentric coordinates can be extended to specify derivatives at control points. This is also known as Hermite interpolation. We introduce a method to modify existing barycentric coordinates to higher order barycentric coordinates and demonstrate, using higher order mean value coordinates, that our method, although conceptually simple and easy to implement, can be used to give easy and intuitive control at interactive frame rates over local space deformations such as rotations.
A Fast Simulation Method Using Overlapping Grids for Interactions between Smoke and Rigid Objects
Authors: Dobashi Yoshinori , Matsuda Yasuhiro , Yamamoto Tsuyoshi , Nishita Tomoyuki
Published: April 2008

Recently, many techniques using computational fluid dynamics have been proposed for the simulation of natural phenomena such as smoke and fire. Traditionally, a single grid is used for computing the motion of fluids. When an object interacts with a fluid, the resolution of the grid must be sufficiently high because the shape of the object is represented by a shape sampled at the grid points. This increases the number of grid points that are required, and hence the computational cost is increased. To address this problem, we propose a method using multiple grids that overlap with each other. In addition to a large single grid (a global grid) that covers the whole of the simulation space, separate grids (local grids) are generated that surround each object. The resolution of a local grid is higher than that of the global grid. The local grids move according to the motion of the objects. Therefore, the process of resampling the shape of the object is unnecessary when the object moves. To accelerate the computation, appropriate resolutions are adaptively‐determined for the local grids according to their distance from the viewpoint. Furthermore, since we use regular (orthogonal) lattices for the grids, the method is suitable for GPU implementation. This realizes the real‐time simulation of interactions between objects and smoke.
Visualizing Underwater Ocean Optics
Authors: Gutierrez Diego , Seron Francisco J. , Munoz Adolfo , Anson Oscar
Published: April 2008

Simulating the in‐water ocean light field is a daunting task. Ocean waters are one of the richest participating media, where light interacts not only with water molecules, but with suspended particles and organic matter as well. The concentration of each constituent greatly affects these interactions, resulting in very different hues. Inelastic scattering events such as fluorescence or Raman scattering imply energy transfers that are usually neglected in the simulations. Our contributions in this paper are a bio‐optical model of ocean waters suitable for computer graphics simulations, along with an improved method to obtain an accurate solution of the in‐water light field based on radiative transfer theory. The method provides a link between the inherent optical properties that define the medium and its apparent optical properties, which describe how it looks. The bio‐optical model of the ocean uses published data from oceanography studies. For inelastic scattering we compute all frequency changes at higher and lower energy values, based on the spectral quantum efficiency function of the medium. The results shown prove the usability of the system as a predictive rendering algorithm. Areas of application for this research span from underwater imagery to remote sensing; the resolution method is general enough to be usable in any type of participating medium simulation.
Interactive Volume Rendering with Dynamic Ambient Occlusion and Color Bleeding
Authors: Ropinski Timo , Meyer‐Spradow Jennis , Diepenbrock Stefan , Mensmann Jörg , Hinrichs Klaus
Published: April 2008

We propose a method for rendering volumetric data sets at interactive frame rates while supporting dynamic ambient occlusion as well as an approximation to color bleeding. In contrast to ambient occlusion approaches for polygonal data, techniques for volumetric data sets have to face additional challenges, since by changing rendering parameters, such as the transfer function or the thresholding, the structure of the data set and thus the light interactions may vary drastically. Therefore, during a preprocessing step which is independent of the rendering parameters we capture light interactions for all combinations of structures extractable from a volumetric data set. In order to compute the light interactions between the different structures, we combine this preprocessed information during rendering based on the rendering parameters defined interactively by the user. Thus our method supports interactive exploration of a volumetric data set but still gives the user control over the most important rendering parameters. For instance, if the user alters the transfer function to extract different structures from a volumetric data set the light interactions between the extracted structures are captured in the rendering while still allowing interactive frame rates. Compared to known local illumination models for volume rendering our method does not introduce any substantial rendering overhead and can be integrated easily into existing volume rendering applications. In this paper we will explain our approach, discuss the implications for interactive volume rendering and present the achieved results.
Viewfinder Alignment
Authors: Adams Andrew , Gelfand Natasha , Pulli Kari
Published: April 2008

The viewfinder of a digital camera has traditionally been used for one purpose: to display to the user a preview of what is seen through the camera's lens. High quality cameras are now available on devices such as mobile phones and PDAs, which provide a platform where the camera is a programmable device, enabling applications such as online computational photography, computer vision‐based interactive gaming, and augmented reality. For such online applications, the camera viewfinder provides the user's main interaction with the environment. In this paper, we describe an algorithm for aligning successive viewfinder frames. First, an estimate of inter‐frame translation is computed by aligning integral projections of edges in two images. The estimate is then refined to compute a full 2D similarity transformation by aligning point features. Our algorithm is robust to noise, never requires storing more than one viewfinder frame in memory, and runs at 30 frames per second on standard smartphone hardware. We use viewfinder alignment for panorama capture, low‐light photography, and a camera‐based game controller.
Image‐based Material Weathering
Authors: Xuey Su , Wang Jiaping , Tong Xin , Dai Qionghai , Guo Baining
Published: April 2008

The appearance manifold [WTL*06] is an efficient approach for modeling and editing time‐variant appearance of materials from the BRDF data captured at single time instance. However, this method is difficult to apply in images in which weathering and shading variations are combined. In this paper, we present a technique for modeling and editing the weathering effects of an object in a single image with appearance manifolds. In our approach, we formulate the input image as the product of reflectance and illuminance. An iterative method is then developed to construct the appearance manifold in color space (i.e., Lab space) for modeling the reflectance variations caused by weathering. Based on the appearance manifold, we propose a statistical method to robustly decompose reflectance and illuminance for each pixel. For editing, we introduce a “pixel‐walking” scheme to modify the pixel reflectance according to its position on the manifold, by which the detailed reflectance variations are well preserved. We illustrate our technique in various applications, including weathering transfer between two images that is first enabled by our technique. Results show that our technique can produce much better results than existing methods, especially for objects with complex geometry and shading effects.
Distortion‐Free Steganography for Polygonal Meshes
Authors: Bogomjakov Alexander , Gotsman Craig , Isenburg Martin
Published: April 2008

We present a technique for steganography in polygonal meshes. Our method hides a message in the indexed rep‐resentation of a mesh by permuting the order in which faces and vertices are stored. The permutation is relative to a reference ordering that encoder and decoder derive from the mesh connectivity in a consistent manner. Our method is distortion‐free because it does not modify the geometry of the mesh. Compared to previous steganographic methods for polygonal meshes our capacity is up to an order of magnitude better.

Our steganography algorithm is universal and can be used instead of the standard permutation steganography algorithm on arbitrary datasets. The standard algorithm runs in Ω (n2 log2 n log log n) time and achieves optimal O(nlog n) bit capacity on datasets with n elements. In contrast, our algorithm runs in O(n) time, achieves a capacity that is only one bit per element less than optimal, and is extremely simple to implement.