bluuebunny/crossref_metadata_2025 huggingface dataset:
Quality Measures for Symptoms and Advance Care Planning in Cancer: A Systematic Review
Authors: Lorenz Karl A. , Lynn Joanne , Dy Sydney , Wilkinson Anne , Mularski Richard A. , Shugarman Lisa R. , Hughes Rhonda , Asch Steven M. , Rolon Cony , Rastegar Afshin , Shekelle Paul G.
Published: October 2006

Purpose

Measuring quality of care for symptom management and ascertaining patient goals offers an important step toward improving palliative cancer management. This study was designed to identify systematically the quality measures and the evidence to support their use in pain, dyspnea, depression, and advance care planning (ACP), and to identify research gaps.

Methods

English-language documents were selected from MEDLINE, Cumulative Index to Nursing and Allied Health, PsycINFO (1995 to 2005); Internet-based searches; and contact with measure developers. We used terms for each domain to select studies throughout the cancer care continuum. We included measures that expressed a normative relationship to quality, specified the target population, and specified the indicated care. Dual data review and abstraction was performed by palliative care researchers describing populations, testing, and attributes for each measure.

Results

A total of 4,599 of 5,182 titles were excluded at abstract review. Of 537 remaining articles, 19 contained measures for ACP, six contained measures for depression, five contained measures for dyspnea, and 20 contained measures for pain. We identified 10 relevant measure sets that included 36 fully specified or fielded measures and 14 additional measures (16 for pain, five for dyspnea, four for depression, and 25 for ACP). Most measures were unpublished, and few had been tested in a cancer population. We were unable to describe the specifications of all measures fully and did not search for measures for pain and depression that were not cancer specific.

Conclusion

Measures are available for assessing quality and guiding improvement in palliative cancer care. Existing measures are weighted toward ACP, and more nonpain symptom measures are needed. Additional testing is needed before the measures are used for accountability, and basic research is required to address measurement when self-report is impaired.
Randomized Phase II Trial of Docetaxel/Irinotecan and Gemcitabine/Irinotecan With or Without Celecoxib in the Second-Line Treatment of Non–Small-Cell Lung Cancer
Authors: Lilenbaum Rogerio , Socinski Mark A. , Altorki Nasser K. , Hart Lowell L. , Keresztes Roger S. , Hariharan Subramanian , Morrison Mark E. , Fayyad Rana , Bonomi Phillip
Published: October 2006

Purpose

Trials combining irinotecan/docetaxel and irinotecan/gemcitabine in second-line treatment of non–small-cell lung cancer (NSCLC) have yielded promising results. Preliminary data suggested that the selective cyclooxygenase -2 inhibitor celecoxib (CBX) might enhance efficacy of chemotherapeutic regimens. This multicenter, phase II, randomized trial investigated efficacy and safety of irinotecan and docetaxel and irinotecan and gemcitabine, with or without CBX, in second-line treatment of NSCLC.

Patients and Methods

Patients 18 years or older were randomly assigned to receive irinotecan 60 mg/m2and docetaxel 35 mg/m2, or irinotecan 100 mg/m2and gemcitabine 1,000 mg/m2, with or without CBX 400 mg twice daily, for four cycles. Primary efficacy end points were median and 1-year survival probabilities. Patient-reported symptoms were assessed by the Lung Cancer Symptoms Scale (LCSS).

Results

A total of 133 patients were assessable for efficacy and safety. Median survival time was 6.31 months for patients treated with CBX and 8.99 months for those treated with chemotherapy alone. One-year survival rates were 24% and 36% respectively. The overall toxicity rates and LCSS scores were similar between patients treated or not treated with CBX. Four deaths were considered possibly treatment related.

Conclusion

Survival results for the second-line regimens in this study were similar to results reported for single-agent therapy in this setting. CBX did not appear to enhance efficacy or improve patient-reported symptoms. The addition of high-dose CBX to second-line chemotherapy in NSCLC cannot be recommended.
Phase II Trial of Bexarotene Capsules in Patients With Advanced Non–Small-Cell Lung Cancer After Failure of Two or More Previous Therapies
Authors: Govindan Ramaswamy , Crowley John , Schwartzberg Lee , Kennedy Peter , Williams Charles , Ekstrand Bradley , Sandler Alan , Jaunakais Dinah , Bolejack Vanessa , Ghalie Richard
Published: October 2006

Purpose

To evaluate the effect of bexarotene on survival in patients with relapsed non–small-cell lung cancer (NSCLC).

Patients and Methods

Patients with stage IIIB NSCLC with pleural effusion or stage IV NSCLC, who had Eastern Cooperative Oncology Group performance status 0 to 2, and were previously treated with ≥ two different regimens that must have included a platinum and a taxane, received oral bexarotene 400 mg/m2/d plus concomitant levothyroxine and a lipid-lowering agent. Primary efficacy end point was survival.

Results

For the 146 assessable patients treated with bexarotene, median age was 66 years (range, 34 to 87 years), 51% were men, and the median number of prior regimens was three (range, one to seven). The overall median survival was 5 months (95% CI, 4 to 7 months) and the 1-year survival was 23% (95% CI, 16% to 31%). Survival was significantly longer in patients with bexarotene-induced hypertriglyceridemia and/or skin rash. In 26 patients who had both adverse effects, the median and 1-year survival rates were 12 months (95% CI, 8 to 15 months) and 48%, respectively. In 40 patients who had neither adverse effect, median and 1-year survival rates were 2 months (95% CI, 2 to 5 months) and 15%, respectively (P = .0002). Twenty patients (14%) discontinued therapy because of bexarotene-related toxicity. For the remaining patients, adverse reactions to bexarotene were generally mild to moderate.

Conclusion

In the intent-to-treat population, bexarotene given as third or subsequent line of therapy for relapsed NSCLC did not achieve the intended median survival of 6 months. Survival may have been extended in patients who developed bexarotene-induced hypertriglyceremia and/or skin rash. It is important to confirm these observations in a randomized controlled trial.
Hemorrhagic Complications Of External Ventricular Drainage
Authors: Maniker Allen H. , Vaynman Artem Y. , Karimi Reza J. , Sabit Aria O. , Holland Bart
Published: October 2006

OBJECTIVE:

Despite the widespread use of external ventricular drainage (EVD), the frequency of associated hemorrhagic complications remains unclear. This retrospective study examined the frequency of hemorrhagic complications of EVD and attempted to discern associated risk factors.

METHODS:

Treatment records from 160 patients admitted during a 2.5-year period who required EVD placement were reviewed. Indications for placement of EVD included acute complications of cerebrovascular disease (n = 94), traumatic brain injury (n = 36), primary hydrocephalus (n = 16), and tumor (n = 14). Patients received either a 3.0 or 2.5-mm outer diameter ventricular catheter (n = 82 and 78, respectively). Postinsertion computed tomographic scans were obtained within 24 hours on all patients and were analyzed for any new hemorrhage related to the ventricular catheter. Patient age, sex, catheter type, and dimensions of hemorrhage were also analyzed.

RESULTS:

The incidence of EVD-related hemorrhage was 33 ± 0.04%. However, the incidence of detectable change in the clinical neurological examination was 2.5%. A significant proportion of EVD-related hemorrhages were small (<4 cm3), punctate, intraparenchymal hematomas. Patients with cerebrovascular disease exhibited an increased incidence (39%) of hemorrhage. The mean volume of intraparenchymal hemorrhage was larger in patients who received the 2.5-mm ventricular catheter, as well as those admitted for cerebrovascular disease.

CONCLUSION:

Hemorrhagic complications of EVD placement are more common than previously suspected. Admitting diagnosis seems to have an effect on the development of an associated hemorrhage and its size. Catheter gauge has an effect on hematoma volume. Most of the hemorrhages seen on postinsertion computed tomographic scans do not cause detectable changes in the clinical examination.
Meyer's Loop and the Optic Radiations in the Transsylvian Approach to the Mediobasal Temporal Lobe
Authors: Choi Chanyoung , Rubino Pablo A. , Fernandez-Miranda Juan C. , Abe Hiroshi , Rhoton Albert L.
Published: October 2006

OBJECTIVE:

In the transsylvian approach to the mediobasal temporal structures, the temporal horn is approached through the floor of the sylvian fissure. The anterior bundle of the optic radiations (Meyer's loop) courses between the floor of the sylvian fissure and roof of the temporal horn and could be damaged in this approach. This study was designed to define the route through the floor of the sylvian fissure least likely to damage the optic pathways.

METHODS:

Meyer's loop was dissected by applying Klingler's fiber dissection technique in 10 formalin-fixed human hemispheres. Several measurements quantified the relationship of the Meyer's loop to surgically important structures.

RESULTS:

This study identified a triangular safe area below the floor of the sylvian fissure through which the temporal horn could be accessed in the transsylvian approach with a low risk of damaging the optic radiations. An incision in the floor of the sylvian fissure directed downward at the level of limen insula and the adjacent 5 mm of the inferior insular sulcus would avoid the optic radiations. An incision directed straight downward 10, 15, and 20 mm behind the limen in the inferior insular sulcus would cross Meyer's loop and would need to be directed downward and medially as much as 80 degrees from the sagittal plane to avoid Meyer's loop.

CONCLUSION:

In the transsylvian approach to the temporal horn, incisions at the level of the limen, or adjacent 5 mm of the inferior insular sulcus, are less likely to damage Meyer's loop and the optic radiations than more posterior incisions along the inferior insular sulcus. Incision at this safe level commonly opens into the amygdala, a portion of which is removed to provide entry into the temporal horn for removal of the mediobasal structures.
Minimally Invasive Transmuscular Pedicle Screw Fixation of the Thoracic and Lumbar Spine
Authors: Ringel Florian , Stoffel Michael , Stüer Carsten , Meyer Bernhard
Published: October 2006

OBJECTIVE:

This study assessed the feasibility and safety of percutaneous posterior pedicle screw fixation for instabilities of the thoracic and lumbar spine, using standard instruments designed for the open approach and fluoroscopy.

METHODS:

All patients who underwent percutaneous posterior pedicle screw fixation of the thoracic and lumbar spine were studied retrospectively. Charts and operative notes were analyzed for epidemiological data, underlying spinal pathological features, and indications for stabilization, stabilized segments, number of implanted pedicle screws, surgical time, and complications. Postoperative computed tomographic scans were analyzed for screw position.

RESULTS:

From May 2002 through May 2005, 115 internal fixators were implanted percutaneously in 104 patients. A total of 488 pedicle screws were implanted, stabilizing 1 to 5 spinal motion segments. Median surgical time was 93 minutes. On postoperative computed tomographic scans, 87% of screw positions were rated good, 10% were rated acceptable, and 3% were rated unacceptable. A total of 11 revisions were necessary, 9 for misplaced screws and 2 for loosening of anchor bolts. Only two of the patients experienced new clinical symptoms (i.e., radicular pain) because of screw misplacement. No patients experienced new neurological deficits or other surgery-related morbidity. @@@@CONCLUSION:@@ This study shows that percutaneous internal pedicle screw fixation using standard instruments is feasible and safe for posterior stabilization of the thoracic and lumbar spine. It is a straightforward alternative for open approaches or minimally invasive ones using navigation in conjunction with customized instruments. Accuracy of screw placement is similar to that reported for other techniques.
Extended Bifrontal Craniotomy for Midline Anterior Fossa Meningiomas:Minimization of Retraction-Related Edema and Surgical Outcomes
Authors: Chi John H. , Parsa Andrew T. , Berger Mitchel S. , Kunwar Sandeep , McDermott Michael W.
Published: October 2006

OBJECTIVE:

Meningiomas of the anterior cranial base can be approached with a variety of techniques. The extended bifrontal approach is often thought to be associated with increased morbidity because of the need for extensive removal of the bone and longer surgical times. The authors have attempted to quantitate retraction-related edema occurring after surgery to determine whether the extra bone removal limits retraction and reduces the chance of brain injury.

METHODS:

Charts were reviewed for patients who underwent extended bifrontal craniotomies performed for meningiomas at the University of California, San Francisco, between 1997 and 2005. Magnetic resonance imaging scans obtained before and after surgery were reviewed for brain edema as indicated by fluid-attenuated inversion recovery/T2 abnormality and grouped into four categories: A, no edema; B, edema restricted to the gyrus rectus; C, edema beyond the gyrus rectus; and D, extensive bifrontal edema.

RESULTS:

Forty-five patients were identified. Fifty-four percent of patients had tumors with a diameter of more than 4 cm. Simpson Grade 2 or 3 resection was achieved in 82% of patients, and the average operative time was 12.3 hours. Vision outcome was favorable in 74% of patients. Extent of fluid-attenuated inversion recovery abnormality remained unchanged in 87.5%, with 91% of patients in categories A or B edema remaining in those categories after surgery. There were no infections and there were two cerebrospinal fluid leaks.

CONCLUSION:

The extended bifrontal approach is a safe surgical procedure with limited morbidity that the authors think: 1) prevents secondary brain injury from excessive retraction; 2) offers great flexibility of view for the surgeon; and 3) should be considered the preferred approach compared with the standard bifrontal craniotomy for large tumors of the anterior cranial base.
The Subtemporal Interdural Approach to Dumbbell-Shaped Trigeminal Schwannomas: Cadaveric Prosection
Authors: Youssef Samy , Kim Eun-Young , Aziz Khaled M.A. , Hemida Salah , Keller Jeffrey T. , van Loveren Harry R.
Published: October 2006

OBJECTIVE:

Successful resection of dumbbell-shaped trigeminal schwannomas via a subtemporal interdural approach requires an understanding of both the anatomy related to the bone dissection of the petrous apex (Kawase's triangle or quadrilateral) and meningeal anatomy. We studied the meningeal anatomy related to this approach and describe the dural incisions and stepwise mobilization.

METHODS:

Meningeal anatomy around Meckel's cave and porus trigeminus was examined during the subtemporal interdural anterior transpetrosal approach in both sides of 15 cadaveric heads. Histological study of the Meckel's cave region was performed in two cadaveric heads.

RESULTS:

The Gasserian ganglion and trigeminal roots have two layers of dura propria on their dorsolateral surface: an inner layer from the posterior fossa dura propria that constitutes the dorsolateral wall of Meckel's cave and an outer layer from the dura propria of the middle fossa. The cleavage plane between these two layers continues distally as the cleavage plane between the epineural sheaths of the trigeminal divisions and the dura propria of the middle fossa. This cleavage plane serves as the anatomic landmark for the interdural exposure of the contents of Meckel's cave. The superior petrosal sinus is sectioned at the medial aspect of Kawase's triangle and reflected along with the porus trigeminus roof.

CONCLUSION:

Understanding the critical meningeal architecture in and around Meckel's cave allows experienced cranial neurosurgeons to develop a subtemporal interdural approach to dumbbell-shaped trigeminal schwannomas that effectively converts a multiple-compartment tumor into a single-compartment tumor. Dural incisions and stepwise mobilization complements our previous description of the bony dissection for this approach.
Training in Cerebrovascular Disease: Do We Need to Change the Way We Train Residents?
Authors: Sauvageau Eric , Hopkins L Nelson
Published: October 2006

WITH THE ONGOING development of endovascular techniques and technologies, treatment of cerebrovascular disease is evolving at a fast pace. For neurosurgery to maintain a leadership role in the treatment of these disorders, modifications in neurosurgical training programs are essential. In this article, we discuss the changes perceived to enable residents to acquire the multifaceted understanding and skill set necessary to meet the new clinical reality and prepare to become the leaders of tomorrow in the management of cerebrovascular disease.
Giant Intracranial Aneurysms: Endovascular Challenges
Authors: Parkinson Richard J. , Eddleman Christopher S. , Batjer H Hunt , Bendok Bernard R.
Published: October 2006

THE TREATMENT OF giant aneurysms remains a formidable challenge for endovascular and surgical strategies. The use of endovascular techniques in a deconstructive (e.g., parent vessel occlusion) and reconstructive (e.g., stent coiling) methodology is reviewed. The results of endovascular coiling as a primary therapy for giant aneurysm occlusion have been disappointing. Hunterian strategies have had more success in published series, but recent developments in coil, glue, and stent technology show great promise in allowing parent vessel reconstruction as a primary endovascular target, with acceptable morbidity, mortality, and durability. A literature review of giant aneurysm endovascular treatment strategies was undertaken after 1994, when Guglielmi detachable coils were approved by the Food and Drug Administration. Where possible, follow-up, durability, and occlusion rates are also reviewed.
Targeting Cerebral Arteriovenous Malformations for Minimally Invasive Therapy
Authors: Alexander Michael J. , Tolbert Marshall E.
Published: October 2006

OBJECTIVE:

Cerebral arteriovenous malformation (AVM) embolization has been performed for nearly 40 years to reduce the risk of hemorrhage, to reduce symptomatic arteriovenous shunting, and to pretreat patients for surgical excision or radiosurgery. In some cases, embolization alone may be able to angiographically cure an AVM, although this is a small percentage of all AVMs.

METHODS:

This report reviews the current limitations of embolic therapy of cerebral AVMs from the standpoint of AVM angioarchitecture and the physical limitations of current embolic materials. In addition, it seeks to identify the areas in which embolization therapy may make advancements both as a pretreatment and as a sole therapy.

RESULTS:

Currently, liquid embolic agents, ethylene vinyl alcohol, and n-butylcyanoacrylate seem to provide the greatest resistance to recanalization in AVM embolization. These agents, however, elicit only a weak, nonspecific, bioactive inflammatory response by histopathology.

CONCLUSION:

The further evaluation and understanding of the vascular biology of AVM vessels and the endothelium cell wall biology will help us devise more bioactive material solutions to AVM nidus obliteration. Targeting specific receptors in AVMs with the embolic material delivered may additionally enhance the effects of radiosurgery in these patients.
Workforce Needs for Endovascular Neurosurgery
Authors: Ecker Robert D. , Levy Elad I. , Hopkins L Nelson
Published: October 2006

DURING THE PAST decade, endovascular techniques and clinical experience have matured to the point that all or a significant part of the treatment of acute ischemic stroke, cerebral aneurysms, brachiocephalic occlusive disease, and arteriovenous fistulae or malformations is performed in angiography suites by neuroradiologists, vascular surgeons, peripheral interventionists, cardiologists, neurologists, and neurosurgeons worldwide. With improvements in technology and lower morbidity rates, the scope of endovascular techniques will only increase. Currently, in the United States alone, this amounts to a volume of more than 500,000 patients annually. Neurosurgeons currently provide only a small portion of the care of these patients. The workforce needs for endovascular surgeons in neurosurgery will be determined by the patients, the willingness of neurosurgeons to embrace endovascular techniques, and the broad scope of cerebrovascular disorders that can be treated.
Intracranial Head and Neck Tumors: Endovascular Considerations, Present and Future
Authors: Gupta Rishi , Thomas Ajith J. , Horowitz Michael
Published: October 2006

TO REVIEW THE literature on endovascular therapies available to clinicians to aid in the management of head, neck, and intracranial tumors. Hypervascular tumors of the head and neck region, as well as the intracranial region, are associated with large amounts of blood loss intraoperatively. Preoperative embolization of selected hypervascular tumors has been proposed in the literature as a method of reducing blood loss intraoperatively. This technique involves superselective catheterization of the feeding arteries to the tumor bed and then by infusion of embolic particles to saturate the tumor bed in the hopes of inducing necrosis. For less vascular tumors, selective infusion of chemotherapeutic agents has been reported as a method of reducing the systemic toxic effects of these medications. Endovascular therapies for hypervascular and less vascular tumors hold promise, although multicenter randomized controlled trials are required to help identify the patients that will benefit the most.
Endovascular Management of Cerebral Vasospasm
Authors: Zwienenberg-Lee Marike , Hartman Jonathan , Rudisill Nancy , Muizelaar Jan Paul
Published: October 2006

CEREBRAL VASOSPASM REMAINS a leading cause of death and disability in patients with ruptured cerebral aneurysms. The development of endovascular intervention in the past two decades has shown promising results in the treatment of vasospasm. Endovascular techniques that have been used in humans include intra-arterial infusion of vasorelaxants and direct mechanical dilation with transluminal balloon angioplasty. This article reviews the current indications and role of endovascular therapy in the management of cerebral vasospasm, its clinical significance, and potential future therapies.
Ontogeny of air-motion sensing in cricket
Authors: Dangles O. , Pierre D. , Magal C. , Vannier F. , Casas J.
Published: October 2006

Juvenile crickets suffer high rates of mortality by natural predators that they can detect using extremely sensitive air-sensing filiform hairs located on their cerci. Although a huge amount of knowledge has accumulated on the physiology, the neurobiology and the biomechanics of this sensory system in adults, the morphological and functional aspects of air sensing have not been as well studied in earlier life history stages. Using scanning electronic microscopy, we performed a survey of all cercal filiform hairs in seven instars of the wood cricket (Nemobius sylvestris). Statistical analyses allowed us to quantify profound changes in the number, the length and the distribution of cercal hairs during development. Of particular importance,we found a fivefold increase in hair number and the development of a bimodal length-frequency distribution of cercal hairs from the second instar onwards. Based on theoretical estimations of filiform hair population coding, we found that the cercal system is functional for a wide range of frequencies of biologically relevant oscillatory flows, even from the first instar. As the cricket develops, the overall sensitivity of the cercal system increases as a result of the appearance of new hairs, but the value of the best tuned frequency remains fixed between 150 and 180 Hz after the second instar. These frequencies nicely match those emitted by natural flying predators, suggesting that the development of the cercal array of hairs may have evolved in response to such signals.
Aquatic turning performance of painted turtles (Chrysemys picta)and functional consequences of a rigid body design
Authors: Rivera Gabriel , Rivera Angela R. V. , Dougherty Erin E. , Blob Richard W.
Published: October 2006

The ability to capture prey and avoid predation in aquatic habitats depends strongly on the ability to perform unsteady maneuvers (e.g. turns), which itself depends strongly on body flexibility. Two previous studies of turning performance in rigid-bodied taxa have found either high maneuverability or high agility, but not both. However, examinations of aquatic turning performance in rigid-bodied animals have had limited taxonomic scope and, as such, the effects of many body shapes and designs on aquatic maneuverability and agility have yet to be examined. Turtles represent the oldest extant lineage of rigid-bodied vertebrates and the only aquatic rigid-bodied tetrapods. We evaluated the aquatic turning performance of painted turtles, Chrysemys picta (Schneider, 1783) using the minimum length-specific radius of the turning path (R/L) and the average turning rate(ωavg) as measures of maneuverability and agility,respectively. We filmed turtles conducting forward and backward turns in an aquatic arena. Each type of turn was executed using a different pattern of limb movements. During forward turns, turtles consistently protracted the inboard forelimb and held it stationary into the flow, while continuing to move the outboard forelimb and both hindlimbs as in rectilinear swimming. The limb movements of backward turns were more complex than those of forward turns, but involved near simultaneous retraction and protraction of contralateral fore- and hindlimbs, respectively. Forward turns had a minimum R/L of 0.0018 (the second single lowest value reported from any animal) and a maximum ωavg of 247.1°. Values of R/L for backward turns (0.0091-0.0950 L) were much less variable than that of forward turns (0.0018-1.0442 L). The maneuverability of turtles is similar to that recorded previously for rigidbodied boxfish. However, several morphological features of turtles (e.g. shell morphology and limb position) appear to increase agility relative to the body design of boxfish.
The catch state of mollusc catch muscle is established during activation:experiments on skinned fibre preparations of the anterior byssus retractor muscle of Mytilus edulis L. using the myosin inhibitors orthovanadate and blebbistatin
Authors: Andruchov Oleg , Andruchova Olena , Galler Stefan
Published: October 2006

Catch is a holding state of muscle where tension is maintained passively for long time periods in the absence of stimulation. The catch state becomes obvious after termination of activation; however, it is possible that catch linkages are already established during activation. To investigate this,skinned fibre bundles of the anterior byssus retractor muscle of Mytilus edulis were maximally activated with Ca2+ and subsequently exposed to 10 mmol l-1 orthovanadate (Vi) or 5 μmol l-1 blebbistatin to inhibit the force-generating myosin head cross-bridges. Repetitive stretches of about 0.1% fibre bundle length were applied to measure stiffness. Inhibitor application depressed force substantially but never resulted in a full relaxation. The remaining force was further decreased by moderate alkalization (change of pH from 6.7 to 7.4) or by cAMP. Furthermore, the stiffness/force ratio was higher during exposure to Vi or blebbistatin than during partial Ca2+ activation producing the same submaximal force. The increased stiffness/force ratio was abolished by moderate alkalization or cAMP. Finally, the stretch-induced delayed force increase (stretch activation) disappeared, and the force recovery following a quick release of the fibre length, was substantially reduced when the force was depressed by Vi or blebbistatin. All these findings suggest that catch linkages are already established during maximal Ca2+ activation. They seem to exhibit ratchet properties because they allow shortening and resist stretches. In isometric experiments a force decrease is needed to stress the catch linkages in the high resistance direction so that they contribute to force.
Antioxidant protection, carotenoids and the costs of immune challenge in greenfinches
Authors: Hõrak Peeter , Zilmer Mihkel , Saks Lauri , Ots Indrek , Karu Ulvi , Zilmer Kersti
Published: October 2006

Costs accompanying immune challenges are believed to play an important role in life-history trade-offs and warranting the honesty of signal traits. We performed an experiment in captive greenfinches (Carduelis chlorisL.) in order to test whether and how humoral immune challenge with non-pathogenic antigen [sheep red blood cells (SRBC)] affects parameters of individual condition including intensity of coccidian infection, estimates of total antioxidant protection, plasma carotenoids and ability to mount a cell-mediated immune response. We also asked whether the potential costs of immune challenge can be alleviated by dietary carotenoid supplementation. None of the treatments affected intensity of coccidiosis. Humoral immune challenge suppressed the cell-mediated response to phytohemagglutinin (PHA), suggesting a trade-off between the uses of different arms of the immune system. Immune challenge reduced body-mass gain, but only among the carotenoid-depleted birds, indicating that certain somatic costs associated with immune system activation can be alleviated by carotenoids. No evidence for oxidative stress-induced immunopathological damages could be found because immune activation did not affect total antioxidant protection or carotenoid levels. Carotenoid supplementation inclined birds to fattening, indicating that lutein interfered with lipid metabolism. Altogether, our results support the hypotheses of biological importance of carotenoids and exemplify the overwhelming complexity of their integrated ecophysiological functions.
Extreme diving of beaked whales
Authors: Tyack Peter L. , Johnson Mark , Soto Natacha Aguilar , Sturlese Albert , Madsen Peter T.
Published: October 2006

Sound-and-orientation recording tags (DTAGs) were used to study 10 beaked whales of two poorly known species, Ziphius cavirostris (Zc) and Mesoplodon densirostris (Md). Acoustic behaviour in the deep foraging dives performed by both species (Zc: 28 dives by seven individuals; Md: 16 dives by three individuals) shows that they hunt by echolocation in deep water between 222 and 1885 m, attempting to capture about 30 prey/dive. This food source is so deep that the average foraging dives were deeper (Zc: 1070 m; Md:835 m) and longer (Zc: 58 min; Md: 47 min) than reported for any other air-breathing species. A series of shallower dives, containing no indications of foraging, followed most deep foraging dives. The average interval between deep foraging dives was 63 min for Zc and 92 min for Md. This long an interval may be required for beaked whales to recover from an oxygen debt accrued in the deep foraging dives, which last about twice the estimated aerobic dive limit. Recent reports of gas emboli in beaked whales stranded during naval sonar exercises have led to the hypothesis that their deep-diving may make them especially vulnerable to decompression. Using current models of breath-hold diving, we infer that their natural diving behaviour is inconsistent with known problems of acute nitrogen supersaturation and embolism. If the assumptions of these models are correct for beaked whales,then possible decompression problems are more likely to result from an abnormal behavioural response to sonar.
Air-flow sensitive hairs: boundary layers in oscillatory flows around arthropod appendages
Authors: Steinmann T. , Casas J. , Krijnen G. , Dangles O.
Published: October 2006

The aim of this work is to characterize the boundary layer over small appendages in insects in longitudinal and transverse oscillatory flows. The problem of immediate interest is the early warning system in crickets perceiving flying predators using air-flow-sensitive hairs on cerci, two long appendages at their rear. We studied both types of oscillatory flows around small cylinders using stroboscopic micro-particle image velocimetry as a function of flow velocity and frequency. Theoretical predictions are well fulfilled for both longitudinal and transverse flows. Transverse flow leads to higher velocities than longitudinal flow in the boundary layer over a large range of angles between flow and cylinder. The strong spatial heterogeneity of flow velocities around filiform-shaped appendages is a rich source of information for different flow-sensing animals. Our results suggest that crickets could perceive the direction of incoming danger by having air-flow-sensitive hairs positioned around their entire cerci. Implications for biomimetic flow-sensing MEMS are also presented.
The interactive effects of hypoxia and nitric oxide on catecholamine secretion in rainbow trout (Oncorhynchus mykiss)
Authors: McNeill Brian , Perry Steve F.
Published: October 2006

Experiments were performed to test the hypothesis that exposure of rainbow trout to repetitive hypoxia would result in a decreased capacity of chromaffin cells to secrete catecholamines owing to increased production of nitric oxide(NO), a potent inhibitor of catecholamine secretion. A partial sequence of trout neuronal nitric oxide synthase (nNOS) was cloned and its mRNA was found to be present in the posterior cardinal vein (PCV), the predominant site of chromaffin cells in trout. Using heterologous antibodies, nNOS and endothelial NOS (eNOS) were localized in close proximity to the chromaffin cells of the PCV.

Exposure of trout to acute hypoxia (5.33 kPa for 30 min) in vivoresulted in significant increases in plasma catecholamine and NO levels. However, after 4 days of twice-daily exposures to hypoxia, the elevation of plasma catecholamine levels during hypoxia was markedly reduced. Associated with the reduction in plasma catecholamine levels during acute hypoxia was a marked increase in basal and hypoxia-evoked circulating levels of NO that became apparent after 2-4 days of repetitive hypoxia. The capacity of the chromaffin cells of the hypoxia-exposed fish to secrete catecholamine was assessed by electrical stimulation of an in situ saline-perfused PCV preparation. Compared with control (normoxic) fish, the PCV preparations derived from fish exposed to repeated hypoxia displayed a significant reduction in electrically evoked catecholamine secretion that was concomitant with a marked increased in NO production. This additional rise in NO secretion in preparations derived from hypoxic fish was prevented after adding NOS inhibitors to the perfusate; concomitantly, the reduction in catecholamine secretion was prevented. The increased production of NO during hypoxia in vivo and during electrical stimulation in situ was consistent with significant elevations of nNOS mRNA and protein; eNOS protein was unaffected. These results suggest that the reduced capacity of trout chromaffin cells to secrete catecholamines after repeated hypoxia reflects an increase in the expression of nNOS and a subsequent increase in NO production during chromaffin-cell activation.
Repeated cocaine effects on learning, memory and extinction in the pond snail Lymnaea stagnalis
Authors: Carter Kathleen , Lukowiak Ken , Schenk James O. , Sorg Barbara A.
Published: October 2006

The persistence of drug addiction suggests that drugs of abuse enhance learning and/or impair extinction of the drug memory. We studied the effects of repeated cocaine on learning, memory and reinstatement in the pond snail, Lymnaea stagnalis. Respiratory behavior can be operantly conditioned and extinguished in Lymnaea, and this behavior is dependent on a critical dopamine neuron. We tested the hypothesis that repeated cocaine exposure promotes learning and memory or attenuates the ability to extinguish the memory of respiratory behavior that relies on this dopaminergic neuron. Rotating disk electrode voltammetry revealed a Km and Vmax of dopamine uptake in snail brain of 0.9 μmol l-1 and 558 pmol s-1 g-1 respectively, and the IC50 of cocaine for dopamine was approximately 0.03 μmol l-1. For operant conditioning, snails were given 5 days of 1 h day-1 immersion in water (control) or 0.1 μmol l-1cocaine, which was the lowest dose that maximally inhibited dopamine uptake,and snails were trained 3 days later. No changes were found between the two groups for learning or memory of the operant behavior. However, snails treated with 0.1 μmol l-1 cocaine demonstrated impairment of extinction memory during reinstatement of the behavior compared with controls. Our findings suggest that repeated exposure to cocaine modifies the interaction between the original memory trace and active inhibition of this trace through extinction training. An understanding of these basic processes in a simple model system may have important implications for treatment strategies in cocaine addiction.
Use of urea as a chemosensory cloaking molecule by a bony fish
Authors: Barimo John F. , Walsh Patrick J.
Published: October 2006

Because urea is bioenergetically expensive to synthesize, few aquatic teleostean (bony) fish make or excrete much urea beyond early development and excrete the majority of nitrogenous waste as the readily diffusible ammonia. The gulf toadfish is one of a few adult teleostean fish that excretes predominately urea. Most studies of chemosensing by fish predators have focused on amino acids as odorants, but we tested the chemo-attractiveness of both urea and ammonia. We report that characteristic `prey-attack' behaviors by a key toadfish predator, gray snapper, were elicited by low ammonia concentrations (<100 nmol N l-1) and similar urea concentrations blunted the ammonia-induced component of attacks. Thus, urea functions as a cloaking molecule, explaining why toadfish co-excrete urea with ammonia. Furthermore, ammonia waste is an important chemical attractant for piscine predators.
An experimental study of Pongamia pinnata L. oil as a diesel substitute
Authors: Mahanta P , Mishra S. C. , Kushwah Y. S.
Published: October 2006

Present work deals with testing a performance of a compression ignition (CI) engine with different blends of non-edible oil as well as their methylesters with petrodiesel. Various blends of a non-edible vegetable oil, commonly known as honge ( Pongamia pinnata L.) in India, were prepared and tested over a wide range of engine load. Results obtained from the study showed that 15–20 per cent pongamia methylester-diesel blend (B15 and B20) could be a better fuel in terms of fuel efficiency and power developed. Further, the blend can be used in any existing CI engine without modification and preheating. The pongamia oil is transesterified by using base catalysed transesterification process in a batch type transesterification reactor. Transesterification shows improvement in fuel properties of pongamia oil. Results obtained with B15 and B20 show improvement in brake thermal efficiency and reduction in brake specific fuel consumption, especially at higher load. Emission results show significant reduction in percentage of CO and HC for B15 and B20 at medium and higher power output.
Development of the free piston expander for work recovery in transcritical CO2 refrigeration cycle
Authors: Peng X , Zhang B , Guo B , Xing Z , Shu P
Published: October 2006

Replacing the throttle valve with an expander is beneficial to the performance improvement on the transcritical CO2 refrigeration cycle. The expander is hereby developed for this purpose in this paper. With the required working conditions, performance potential, reliability, etc. considered, the free piston machine is selected as the most suitable concept after a comparison among some candidates. The single acting structure is adopted, in which an auxiliary compressor is arranged on a common shaft to utilize the work recovered by the expander. A slider-based scheme is applied to control the expander inlet/outlet, and an adjustable clearance volume is designed to modulate the operating ranges of the low/high pressures. A design model is established to determine the geometric parameters of the expander-compressor unit. A prototype expander is manufactured and preliminary test is carried out on a test rig with both air and CO2 as the working fluid. The experimental results show that the expander-compressor unit can work in some ranges of the low/high pressures, which proves that this type of expander concept as well as the inlet/outlet control method is feasible. A serious pressure pulsation is observed at the expander inlet, resulting in considerably large pressure drop during the filling process of the expander. The work to improve the expander is therefore being done, with the attenuation of the pressure pulsation focused on.
Hydraulic design of a regenerative flow pump for an artificial heart pump
Authors: Yoo I. S. , Park M. R. , Chung M. K.
Published: October 2006

The present study is focused on the design of a regenerative flow pump for artificial heart pump application and the experimental testing and results. It is based on the improved momentum exchange theory proposed by Yoo et al. [1]. Salient feature of the present design procedure is that it does not require any re-adjustment of the input data. Using the design procedure, a regenerative flow type blood pump has been designed and manufactured to confirm its validity.
A literature survey of water-side fouling applicable to cooling tower condensers
Authors: Zdaniuk G. J. , Chamra L. M. , Mago P. J.
Published: October 2006

Because of the complexity of fouling, it has been primarily studied as individual mechanisms. However, in actual field conditions, multiple mechanisms may be present. Little is understood about how different mechanisms interact. In cooling tower applications, water is treated with corrosion inhibitors and biocides to eliminate biological and corrosion fouling mechanisms. The fouling in cooling towers is, therefore, typically a combination of precipitation and particulate fouling. This paper presents a literature survey of research in the area of particulate, precipitation, and combined fouling modes in heat exchangers that use cooling tower water. Several experiments, models, and correlations are briefly described. The article concludes with a review section on long-term fouling data.
Simulation of dynamics of a boiler steam superheater with an attemperator
Authors: Zima W
Published: October 2006

This paper presents a numerical method to determine the proper rate of spray water mass flow to be supplied to an injection attemperator. The basic aim of this method is to keep the steam temperature of the superheater outlet at a constant (assumed) level, when the parameters of steam at the inlet to the attemperator and combustion gases at the inlet to the superheater vary. The presented method is suggested for digital control of superheated steam temperature. A crucial condition for correct control is setting up a precise numerical model of the superheater, which would provide fast and accurate determination of the cooling water mass flow supplied to the injection attemperator. For that purpose, a model of a superheater with distributed parameters was developed, which comprises solving equations describing the laws of mass, momentum, and energy conservation. The proposed method to determine the mass flowrate of spray water is based on computed steam temperatures at the inlet and outlet of the analysed superheater stage. The so formulated problem, being an inverse one, was solved using the Regula Falsi method. A computational test verifying the proposed solution is presented. A comparison of numerical calculation results and measurements, taken on the platen superheater of a steam boiler type OP-210 with 210 × 103 kg/h capacity, is also presented. In both cases, a fully satisfactory agreement of the computed steam temperature at the superheater outlet with the assumed value was achieved. The suggested solution to the inverse problem, combined with the proposed model of superheater dynamics, enables one to determine the proper mass flow of spray water in on-line mode and improve the control quality.
Calculation procedure for time-dependent deforming interfaces in multi-fluid systems
Authors: Chen D , Lai H , Huang S
Published: October 2006

This article presents a primitive-variable calculation procedure for a time-dependent deforming interface and its relevant conjugate viscous flows in a multi-fluid system. A deforming fluid/fluid interface boundary is explicitly tracked using a moving mesh. In order to decide the shape of the deforming interface separating two conjugate viscous flows on both sides, a ‘modified Ryskin-Leal method’ is proposed. This is combined with the ‘continuous stress method’ for interfacial velocity, previously developed by the authors, to treat the boundary conditions. The governing equations are solved by the SIMPLE method, which is implemented with high-order schemes to obtain high fidelity of interfacial transport and flow phenomena.

The calculation procedure is verified. These include fluid droplets with documented numerical results and air bubbles with experimental data. Further verifications of the algorithm are carried out by numerically studying the dynamic behaviours of a rising air bubble; these dynamic behaviours include the time-dependent rising, deformation, evolution of flow fields, and propagation of concentration field.
Analysis of human body response to vibration using multi-body dynamics method
Authors: Teng T-L , Chang F-A , Peng C-P
Published: October 2006

Research on how vibration affects the human body has indicated that vibration of the whole body can cause spinal injury, low back pain, and uncomfortable feelings and interferecan with working efficiency, safety, and health. The characteristics of human response to vibration need to be understood to reduce these effects of vibration on humans. Experiments in humans for such investigations have limitations. A viable alternative involves approximating the human body using a mathematical model and analysing the desired behaviour of the model. This study establishes a seated human body vibration model using the multi-body dynamics method. The dynamic equations of motion of the mechanical structure are based on Kane's equations as formulated by Huston et al. [24]. The equations are then coded into a computer program and solved using fourth-order Runge-Kutta methods. The developed human body model is employed to examine the biodynamic response of the human body under vertical vibration and to measure the natural frequency and input-output acceleration ratio (transmissibility) of each individual segment received. The multi-body dynamics results closely correspond to the experimental results. The analysis cost of multi-body dynamics method is very low. The procedures described herein contribute to efforts to optimize seat design and analyse human body comfort.
Stabilized index-1 differential-algebraic formulations for sensitivity analysis of multi-body dynamics
Authors: Schaffer A
Published: October 2006

Convergence results are shown for the Hiller-Anantharaman stabilized index-1 differential algebraic equation (DAE) formulation of the DAE of motion of a multi-body system. The formulation is extended to the direct differentiation DAE and the adjoint (A) DAE resulting from the design sensitivity analysis of multi-body dynamics. Convergence of backward differential formula methods applied to the Hiller-Anantharaman formulation is proven not only for the DAE of motion but also for the differentiation DAE and the ADAE. The Hiller-Anantharaman formulation is attractive for multi-body dynamics because of its stabilization properties, resulting from a stabilized index reduction of the original index-3 DAE, and because it yields a DAE that includes the position and velocity constraint equations. In addition, the Hiller-Anantharaman index-1 DAE formulation has the advantage that the currently available index-1 DAE integrators are in a more mature phase than higher-index DAE integrators.