bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clidemia hirta Invasion at the Pasoh Forest Reserve: An Unexpected Plant Invasion in an Undisturbed Tropical Forest1
Authors: Peters Halton A. 
Published: March 2006

ABSTRACT Clidemia hirta is a highly invasive shrub in tropical forests throughout the world, but has had little success invading mainland sites and undisturbed forests. In the early 1990s, this plant was found to have invaded an unexpected site, an undisturbed continental tropical forest at Pasoh, Peninsular Malaysia. In 1997, a study was conducted of the C. hirta population at the Pasoh Forest Reserve. A demographic survey of the 50–ha long–term research plot at Pasoh located 1002 C. hirta individuals, 69 of which were reproductive at the time of the study. All but 8 individuals were located in high light gaps or gap edges. Relative growth rates were significantly higher in gaps and gap edges than in the understory, and no reproductive individuals were found in the understory. Mean plant size and dry biomass density increased steadily over the course of the study, while the observed mortality rate was 0 percent over two months. The biomass density of Clidemia at Pasoh was <500 g/ha at the conclusion of this study, but because the population is confined almost exclusively to high light environments, its density in these sites is much higher. The location of C. hirta plants in gaps was significantly correlated with past disturbance by wild pigs, suggesting that soil disturbance and light availability are essential for their establishment. The implication of this study is that by competing with native species in gaps, C. hirta invasion has the potential to alter forest regeneration at Pasoh. Changing land use practices near the reserve have increased the number of wild pigs, and thus the level of disturbance, which may explain the recent success of C. hirta at Pasoh.
Factors Affecting the Small Mammal Community Inside and Outside Katavi National Park, Tanzania1
Authors: Caro T. M. 
Published: March 2006

ABSTRACTSmall mammal trapping showed that a minimum of 12 species live in and around Katavi National Park in western Tanzania. Species richness and abundance were greater outside the park than inside, extending results of an earlier study. Species richness and abundance were not significantly associated with vegetation cover or plant biomass but were negatively correlated with seed diversity, seed biomass, and possibly small carnivore abundance. Unfortunately, small mammal diets are unknown in this ecosystem and it can be argued that carnivores are unlikely to reduce species diversity, casting doubt on the importance of these variables. While the factors causing small mammals to fare poorly in this protected area are not yet understood, reduced food availability remains the best candidate.
A cosmic relation between extinction and star formation
Authors: Zoran Oren , Barkana Rennan , Thompson Rodger I. 
Published: March 2006

Abstract
We study the relation between the star formation intensity of galaxies and the extinction by dust of their emitted light. We employ a detailed statistical analysis of Hubble Deep Field North data to show a clear positive correlation between the extinction and star formation intensity at all epochs from redshift 0.4 to 6.5. The extinction evidently increases with time for a given star formation intensity, consistent with the expected increase in the metallicity with time. Our observational results are well fitted at all epochs by a double-power-law model with a fixed shape that simply shifts with redshift. The correlation between the extinction and the star formation intensity can be interpreted by combining two other trends: the correlation between the star formation rate and the gas content of galaxies, and the evolution of the dust-to-gas ratio in galaxies. If we assume that Kennicutt's observed relation for the former is valid at each redshift, then our findings imply an interesting variation in the dust-to-gas ratio in galaxies within each epoch and with time, and suggest new ways to investigate the cosmic evolution of this quantity.
Aspect Ratio Effects on Turbulent and Transitional Flow in
Rectangular Microchannels as Measured With MicroPIV
Authors: Li Hao , Olsen Michael G. 
Published: March 2006

Abstract
Microscopic particle image velocimetry (microPIV) was used to measure velocities in rectangular microchannels with aspect ratios ranging from 0.97 to 5.69 for 200&lt;Re&lt;3267. Mean velocity profiles, velocity fluctuations, and Reynolds stresses were determined from the microPIV data. Transition to turbulence was observed at Re=1765-2315 for the five aspect ratios studied, agreeing very well with both recent microscale experiments and macroscale duct flow and indicating no evidence of early transition for any of the aspect ratios studied. The onset of fully turbulent flow was observed at Re=2600-3200. For the fully turbulent flow, the ⟨u′⟩∕umax and ⟨v′⟩∕umax fluctuations at the channel centerline were 6% and 3%–3.5% and generally agreed well with macroscale results. As aspect ratio increased, the ⟨u⟩∕umax and ⟨u′⟩∕umax profiles became flatter, with nearly uniform values extending for some distance from the centerline of the channel. This region of uniform ⟨u⟩∕umax and ⟨u′⟩∕umax became larger with increasing aspect ratio. The Reynolds shear stress for fully turbulent flow also displayed a strong dependence on aspect ratio. For the W∕H=0.97 microchannel, ⟨u′v′⟩∕umax2 steadily increased in value moving from the centerline to the wall, but for the higher aspect ratio microchannels, ⟨u′v′⟩∕umax2 remained close to zero in the center region of the microchannel before increasing in value at locations close to the wall, and this region of near zero ⟨u′v′⟩∕umax2 became larger with increasing aspect ratio. This behavior in the Reynolds shear stress is due to the region of uniform velocity and, hence, small mean shear, near the channel centerline of the high aspect ratio microchannels.
A Method to Predict Cavitation Inception Using Large-Eddy Simulation and its Application to the Flow Past a Square Cylinder
Authors: Wienken W. , Stiller J. , Keller A. 
Published: March 2006

Abstract
A new method to predict traveling bubble cavitation inception is devised. The crux of the method consists in combining the enhanced predictive capabilities of large-eddy-simulation (LES) for flow computation with a simple but carefully designed stability criterion for the cavitation nuclei. For LES a second-order accurate finite element model based on the Galerkin/least-squares method with Runge-Kutta time integration is applied. The incoming nucleus’ spectrum is approximated by a Weibull distribution. Moreover, it is shown that under typical conditions the stability of the nuclei can be evaluated with an algebraic criterion emerging from the Rayleigh-Plesset equation. This criterion can be expressed as modified critical Thoma number and fits well into the LES approach. The method was applied to study cavitation inception in a flow past a square cylinder. A good agreement with experimental results was achieved. Furthermore, the principal advantage over statistical (time-averaged) methods could be clearly demonstrated, even though the spatial resolution and application of the LES were restricted by limited computational resources. As the latter keep on growing, a wider range of applications will become accessible methods for cavitation prediction based on algebraic stability criteria combined with LES.
The Warwick system of prospective workload allocation in cellular pathology—an aid to subspecialisation: a comparison with the Royal College of Pathologists’ system
Authors: Carr R A , Sanders D S A , Stores O P , Smew F A , Parkes M E , Ross-Gilbertson V , Chachlani N , Simon J 
Published: March 2006

Background:Guidelines on staffing and workload for histopathology and cytopathology departmentswas published by the Royal College of Pathologists (RCPath) in July 2003. In this document, a system is provided whereby the workload of a cellular pathology department and individual pathologists can be assessed with a scoring system based on specialty and complexity of the specimens. A similar, but simplified, system of scoring specimens by specialty was developed in the Warwick District General Hospital. The system was based on the specimen type and suggested clinical diagnosis, so that specimens could be allocated prospectively by the laboratory technical staff to even out workload and support subspecialisation in a department staffed by 4.6 whole-time equivalent consultant pathologists.Methods:The pathologists were asked to indicate their reporting preferences to determine specialist reporting teams. The workload was allocated according to the “prospective” Warwick system (based on specimen type and suggested clinical diagnosis, not affected by final diagnosis or individual pathologist variation in reference to numbers of blocks, sections and special stains examined) for October 2003. The cumulative Warwick score was compared with the “retrospective” RCPath scoring system for each pathologist and between specialties. Four pathologists recorded their time for cut-up and reporting for the month audited.Results:The equitable distribution of work between pathologists was ensured by the Warwick allocation and workload system, hence facilitating specialist reporting. Less variation was observed in points reported per hour by the Warwick system (6.3 (range 5.5–6.9)) than by the RCPath system (11.5 (range 9.3–15)).Conclusions:The RCPath system of scoring is inherently complex, is applied retrospectively and is not consistent across subspecialities. The Warwick system is simpler, prospective and can be run by technical staff; it facilitates even workload distribution throughout the day. Subspecialisation within a small-sized or medium-sized department with fair distribution of work between pathologists is also allowed for by this system. Reporting times among pathologists were shown by time and motion studies to be more consistent with Warwick points per hour than with RCPath points per hour.
Fascin is a potential biomarker for early-stage oesophageal squamous cell carcinoma
Authors: Zhang H , Xu L , Xiao D , Xie J , Zeng H , Cai W , Niu Y , Yang Z , Shen Z , Li E 
Published: March 2006

Background:Fascin, an actin-binding protein, is usually expressed at a low level in normal epithelium, but is markedly up regulated in several types of carcinomas. Reports on fascin expression in oesophageal squamous cell carcinoma (ESCC) and precancerous lesions remain rare.Aim:To show the roles of fascin in the progression from normal epithelium to invasive ESCC.Methods:Fascin expression in 102 sections embedded in paraffin wax, including samples of normal mucosa (n = 20), dysplasia (n = 10), ESCC (n = 62) and special sections (n = 10) of a full-length mucosa layer from the distant margin to the cancer focus of the excised oesophagus, and 49 fresh specimens of ESCC was analysed by immunohistochemistry, western blot and real-time reverse transcription-polymerase chain reaction. Fascin expression in ESCC cell lines was also investigated.Results:In the immunohistochemical study, the positive rate of fascin was significantly higher in the tumour tissue than in the normal epithelium (p = 0.020), but no significant difference was shown between ESCC and dysplasia (p = 1.000). Immunostaining for fascin was only apparent in the basal layer of the normal epithelium. However, in the dysplasia, positive staining was observed in most of the heterogeneous cells from the basal layer to the granular layer of the epithelium. Fascin expression was seen to increase progressively from the normal epithelium to invasive ESCC. Up regulation of fascin was observed in 87.76% (43/49) and 77.55% (38/49) of the specimens, respectively, using western blot and real-time reverse transcription-polymerase chain reaction assays; 80% (4/5) of ESCC cell lines also expressed fascin at a high level. Furthermore, overexpression of fascin was markedly correlated with cell proliferation and lymph node metastasis.Conclusions:These findings suggested that fascin was associated with the transformation and development of ESCC and implicated the potential of fascin as a novel biomarker that would allow the tumour to be identified at an early stage in high-risk individuals.
External quality assessment slide schemes: pathologists’ experiences and perceptions
Authors: Parham D M 
Published: March 2006

Background:External quality assessment schemes (EQAS) in pathology have been established in the United Kingdom for several years with the aim of raising standards.Objective:To determine the experiences and perceptions of pathologists undertaking EQAS.Methods:A questionnaire was distributed to histo/cytopathologists in the south and west of England.Results:A large proportion of pathologists responding felt that the EQAS was educational, and 69% said participation had encouraged them to undertake additional educational activities. Some reservations were expressed about marking schemes. Asked if EQAS using digital images (CD-ROM or web based) rather that glass slides were valid alternatives two thirds responded no, despite 75% claiming to have appropriate IT skills.Conclusions:EQAS play a valuable role in helping to maintain standards in histopathology and cytopathology. Some reservations were expressed about the marking schemes and further work is needed to establish a robust marking method. Significant barriers need to be overcome if digital EQAS are to be successfully implemented.
Increased Regulatory T-Cell Fraction Amidst a Diminished CD4 Compartment Explains Cellular Immune Defects in Patients with Malignant Glioma
Authors: Fecci Peter E. , Mitchell Duane A. , Whitesides John F. , Xie Weihua , Friedman Allan H. , Archer Gary E. , Herndon James E. , Bigner Darell D. , Dranoff Glenn , Sampson John H. 
Published: March 2006

AbstractImmunosuppression is frequently associated with malignancy and is particularly severe in patients with malignant glioma. Anergy and counterproductive shifts toward TH2 cytokine production are long-recognized T-cell defects in these patients whose etiology has remained elusive for &gt;30 years. We show here that absolute counts of both CD4+ T cells and CD4+CD25+FOXP3+CD45RO+ T cells (Tregs) are greatly diminished in patients with malignant glioma, but Tregs frequently represent an increased fraction of the remaining CD4 compartment. This increased Treg fraction, despite reduced counts, correlates with and is sufficient to elicit the characteristic manifestations of impaired patient T-cell responsiveness in vitro. Furthermore, Treg removal eradicates T-cell proliferative defects and reverses TH2 cytokine shifts, allowing T cells from patients with malignant glioma to function in vitro at levels equivalent to those of normal, healthy controls. Such restored immune function may give license to physiologic antiglioma activity, as in vivo, Treg depletion proves permissive for spontaneous tumor rejection in a murine model of established intracranial glioma. These findings dramatically alter our understanding of depressed cellular immune function in patients with malignant glioma and advance a role for Tregs in facilitating tumor immune evasion in the central nervous system. (Cancer Res 2006; 66(6): 3294-302)
A prospective clinical study of cerebral microemboli and neuropsychological outcome comparing vent-line and auto-venting arterial line filters: both filters are equally safe
Authors: Whitaker Donald C , Stygall Jan , Hope-Wynne Chris , Walesby Robin K , Harrison Michael JG , Newman Stanton P 
Published: March 2006

Introduction: Microemboli are the main implicated cause of neuropsychological (NP) impairment after cardiac surgery. This prospective clinical trial compared the effect of an auto-venting arterial line filter on intraoperative cerebral microemboli and NP outcome compared to an arterial line filter with a vent line, in patients undergoing elective coronary artery bypass graft (CABG) surgery. Methods: One hundred and ten patients received either an Avecor Affinity ( n = 73) or Pall AV-6 ( n = 37) control filter. Cerebral microemboli during cardiopulmonary bypass were recorded by transcranial Doppler monitoring of the right middle cerebral artery. Evidence of cerebral impairment was obtained by comparing patients’ performance in a NP test battery (nine tests) administered 6-8 weeks postoperatively with their pre-operative scores. Results: During cardiopulmonary bypass, the median number and range of microemboli were 67 (5-846) and 55 (2-773) for the Avecor and AV-6 groups, respectively ( p = 0.47). There was no difference in NP outcome. Conclusion: There is no difference in the filtering ability of vent-line and auto-vent filters as assessed by cerebral microemboli. This, together with the similar NP outcome, suggests that both types of filter are equally safe for clinical use.
Cardiopulmonary bypass for a coronary artery bypass graft patient with heterozygous protein C deficiency and protein S deficiency
Authors: Schneider Susan , Sakert Tamara , Lucke John , McKeown Peter , Sharma Ajeet 
Published: March 2006

Cardiopulmonary bypass (CPB) poses great risks for hypercoagulable patients and requires management techniques to ensure an optimal outcome free from thrombotic events. This case report reviews perfusion management techniques that may contribute to a safer CPB experience for a patient deficient in both protein C and protein S. A patient with heterozygous protein C deficiency is at increased risk of thrombosis, especially in the venous circulation. Since it is an essential cofactor for activated protein C, deficiency of free protein S is also linked to a hypercoagulable condition. A 52-year-old male presented to our institution with a past medical history of hypercoagulable state, multiple deep vein thromboses, pulmonary embolisms, and stroke. He was scheduled for two-vessel coronary artery bypass graft surgery to be followed by right carotid endarterectomy (RCEA) before discharge. The anesthesia and perfusion teams worked closely together to ensure that fresh frozen plasma (FFP) was given intraoperatively at appropriate times. Heparin dose response and protamine dosage was determined with hemostasis management system (HMS) analysis. The closed CPB circuit and cannulae were Carmeda bonded. Rapid autologous priming, along with the use of a hemoconcentrator, kept the hematocrit above 21 during CPB. Zero-balance ultrafiltration and leukocyte depletion were initiated during rewarming to aid in attenuation of the inflammatory response. To conserve coagulation factors, all pump blood was ultrafiltrated post-CPB and returned to the patient. Laboratory samples drawn on postoperative day (POD) one measured normal protein C activity with subnormal protein S activity. On POD six, the patient underwent RCEA and he was discharged on POD eight without complications.
A recovery model of minimally invasive cardiopulmonary bypass in the rat
Authors: Modine T , Azzaoui R , Fayad G , Lacroix D , Bordet R , Warembourg H , Gourlay T 
Published: March 2006

This study was undertaken to develop a rodent (rat) model of cardiopulmonary bypass (CPB) that has been designed to mimic functionally the minimally invasive clinical setting. The circuit is similar to the clinical model in terms of its construction, configuration, material surface area to blood volume ratio, and priming volume to blood ratio. The overall priming volume was 10 mL. Thirty-six male Sprague-Dawley rats (422±32 g) were anaesthetized while maintaining spontaneous ventilation. Anticoagulation was achieved with heparin (500 IU/kg). Blood arterial pressure was monitored continuously. Normal central temperature was maintained throughout. Intermittent arterial blood gas levels also were monitored. All animals were cannulated in preparation for CPB; however, CPB, utilizing a double roller pump and a flow rate of 100 mL/kg/minute for 60 min, was initiated in only 18 animals, the remaining 18 animals acting as non-CPB controls (Sham). The animals were haemodynamically stable. After the operative procedure, the animals were allowed to recover from the anaesthesia and, after transfer to a recovery facility, were monitored for a period of 1 week. There were no differences between the groups in terms of blood gas analysis and blood pressure data; all animals survived the procedure and had an uneventful follow-up. Differences were found between the CPB animals and the Sham group in terms of TNFα, used as a marker of inflammatory processes. This trend tends to support this model as an analogue for the clinical scenario for future studies of CPB-related inflammation. Overall, the CPB procedure was easy to perform and was associated with excellent survival. This recovery model is an effective tool to perform pathophysiological studies associated with minimally invasive CPB.
Testing of heat exchangers in membrane oxygenators using air pressure
Authors: Hamilton Carole , Stein Jutta , Seidler Rainer , Kind Robert , Beck Karin , Tosok Jürgen , Upterfofel Jörg 
Published: March 2006

All heat exchangers (HE) in membrane oxygenators are tested by the manufacturer for water leaks during the production phase. However, for safety reasons, it is highly recommended that HEs be tested again before clinical use. The most common method is to attach the heater-cooler to the HE and allow the water to recirculate for at least 10 min, during which time a water leak should be evident. To improve the detection of water leaks, a test was devised using a pressure manometer with an integrated bulb used to pressurize the HE with air. The cardiopulmonary bypass system is set up as per protocol. A pressure manometer adapted to a 1/2″ tubing is connected to the water inlet side of the oxygenator. The water outlet side is blocked with a short piece of 1/2″ dead-end tubing. The HE is pressurized with 250 mmHg for at least 30 sec and observed for any drop. Over the last 2 years, only one oxygenator has been detected with a water leak in which the air-method leak-test was performed. This unit was sent back to the manufacturer who confirmed the failure. Even though the incidence of water leaks is very low, it does occur and it is, therefore, important that all HEs are tested before they are used clinically. This method of using a pressure manometer offers many advantages, as the HE can be tested outside of the operating room (OR), allowing earlier testing of the oxygenator, no water contact is necessary, and it is simple, easy and quick to perform.