A novel baculovirus vector shows efficient gene delivery of modified porcine reproductive and respiratory syndrome virus antigens and elicits specific immune response

Porcine reproductive and respiratory syndrome (PRRS) is an economically devastating epizootic of porcine species. Current vaccines are inadequate to control the disease burden and outbreaks in the field. We report a novel baculovirus vaccine vector with White spot syndrome virus immediate early 1 shuttle promoter, with strong activity in both insect cells and mammalian cells, for immunization against PRRSV. The insect cell cultured baculovirus vector produces PRRSV envelope glycoproteins ORF2a, ORF3, ORF4 and ORF5, which are similar to the antigens in the infectious PRRS virion, and these antigens are stably incorporated on the surface of the baculovirus. Further, the baculovirus vector efficiently transduces these antigens in cells of porcine origin, thereby simulating a live infection. The baculovirus vectored PRRSV antigens, upon inoculation in mice, elicits robust neutralizing antibodies against the infective PRRS virus. Further, the experiments indicate that hitherto under emphasized ORF2a and ORF4 are important target antigens for neutralizing PRRSV infectivity.

A novel method for assessing the 3-D orientation accuracy of inertial/magnetic sensors

A novel method for assessing the accuracy of inertial/magnetic sensors is presented. The method, referred to as the "residual matrix" method, is advantageous because it decouples the sensor's error with respect to Earth's gravity vector (attitude residual error: pitch and roll) from the sensor's error with respect to magnetic north (heading residual error), while remaining insensitive to singularity problems when the second Euler rotation is close to ±90°. As a demonstration, the accuracy of an inertial/magnetic sensor mounted to a participant's forearm was evaluated during a reaching task in a laboratory. Sensor orientation was measured internally (by the inertial/magnetic sensor) and externally using an optoelectronic measurement system with a marker cluster rigidly attached to the sensor's enclosure. Roll, pitch and heading residuals were calculated using the proposed novel method, as well as using a common orientation assessment method where the residuals are defined as the difference between the Euler angles measured by the inertial sensor and those measured by the optoelectronic system. Using the proposed residual matrix method, the roll and pitch residuals remained less than 1° and, as expected, no statistically significant difference between these two measures of attitude accuracy was found; the heading residuals were significantly larger than the attitude residuals but remained below 2°. Using the direct Euler angle comparison method, the residuals were in general larger due to singularity issues, and the expected significant difference between inertial/magnetic sensor attitude and heading accuracy was not present.

Sagittal plane center of mass movement strategy and joint kinetics during sit-to-walk in elderly fallers

BACKGROUND

Biomechanical studies have shown that the horizontal center of mass momentum at seat-off during sit-to-walk is reduced among elderly adults. However, the underlying mechanism of this phenomenon is still lacking. The purpose of this study was to examine differences in center of mass movement strategies and lower extremity joint kinetics in the elderly during sit-to-walk.

METHODS

Fifteen healthy young adults, fifteen healthy elderly adults (70 years or older) and fifteen elderly fallers performed Timed Up and Go test. Biomechanical data collected from sit-to-walk phase of Timed Up and Go test were analyzed. Outcome measures included center of mass-ankle inclination angles, hip, knee and ankle joint moments, and ground reaction forces of the stance limb.

FINDINGS

Results reported here are from 10 participants in each group due to missing force place data. Elderly fallers adopted a movement strategy that included a posterior foot placement at seat-off, a longer duration, and a shorter initial step length. When compared to healthy individuals, elderly fallers demonstrated a greater ankle plantarflexor moment at seat-off.

INTERPRETATION

Increased ankle plantarflexor moment in elderly fallers could be a movement strategy to improve stability during sit-to-walk and may be related to the reduced ankle dorsiflexor strength commonly reported in elderly fallers. Results of this study enhance our understanding on the underlying mechanisms of the altered sit-to-walk movement and could aid in developing effective screening and rehabilitation programs to prevent falling in the elderly.

The effect of handle design on upper extremity posture and muscle activity during a pouring task

In this study, the effect of container handle parameters on shoulder and upper limb muscle activity and joint posture during a pouring task is investigated. Results indicated that a low handle position and a vertical handle slope minimised the loading of the shoulder muscles. A high and sloped handle minimised the muscle activity and wrist deviation of the lower arm. The effects of diameter were not significant for most dependent variables during the lifting phase of the task; however, beneficial effects were seen with the smallest handle diameter during the pouring phase. A trade-off existed between the shoulder and the hand/wrist posture with the different handles. The findings of significance with relatively small effect size suggest a high sensitivity of the system to any changes. In the real world, speed, space and work conditions are important factors that influence how a task is performed. This emphasises the importance of proper handle design.

PRACTITIONER SUMMARY

In this study, the effect of container handle design on the muscle activity and postures of the upper extremity during a pouring task were analyzed using the experimental data collected from electromyography and motion tracking systems. The low handle height and vertical handle slope design yielded the lowest shoulder muscle activity.

The natural angle between the hand and handle and the effect of handle orientation on wrist radial/ulnar deviation during maximal push exertions

The purpose of this experiment was to quantify the natural angle between the hand and a handle, and to investigate three design factors: handle rotation, handle tilt and between-handle width on the natural angle as well as resultant wrist radial/ulnar deviation ('RUD') for pushing tasks. Photographs taken of the right upper limb of 31 participants (14 women and 17 men) performing maximal seated push exertions on different handles were analysed. Natural hand/handle angle and RUD were assessed. It was found that all of the three design factors significantly affected natural handle angle and wrist RUD, but participant gender did not. The natural angle between the hand and the cylindrical handle was 65 ± 7°. Wrist deviation was reduced for handles that were rotated 0° (horizontal) and at the narrow width (31 cm). Handles that were tilted forward 15° reduced radial deviation consistently (12-13°) across handle conditions.

PRACTITIONER SUMMARY

Manual materials handling (MMH) tasks involving pushing have been related to increased risk of musculoskeletal injury. This study shows that handle orientation influences hand and wrist posture during pushing, and suggests that the design of push handles on carts and other MMH aids can be improved by adjusting their orientation to fit the natural interface between the hand and handle.

Adverse postoperative outcomes in surgical patients with immune thrombocytopenia

Background

Patients with immune thrombocytopenia (ITP) are likely to have various medical co-morbidities, yet their global features regarding adverse postoperative outcomes and use of medical resources when undergoing major surgery are unknown. The objective of this study was to validate whether ITP is an independent risk factor for adverse postoperative outcomes, and to explore the potential clinical predictors of outcomes after major surgery among patients with ITP.

Methods

A retrospective population-based cohort study was conducted using Taiwan's National Health Insurance Research Database, controlling for preoperative co-morbidities by means of multiple logistic regression. Major postoperative complication and mortality rates, and in-hospital medical costs were analysed.

Results

The study included 11 085 surgical patients with ITP and 44 340 controls without ITP matched for sex, age, and type of surgery and anaesthesia. Surgical patients with ITP had a higher risk of postoperative death (odds ratio (OR) 1·89, 95 per cent confidence interval 1·57 to 2·27), and overall postoperative complications (OR 1·47, 1·39 to 1·56), and increased hospital stay (OR 1·90, 1·80 to 2·01), admission to the intensive care unit (OR 1·73, 1·63 to 1·83) and medical costs (OR 1·89, 1·79 to 1·99). Amount of preoperative platelet and/or red blood cell transfusion, emergency visits and admission to hospital for ITP care were identified as risk factors for adverse postoperative outcomes.

Conclusion

Patients with ITP undergoing surgery are at increased risk of adverse perioperative events, particularly if blood or blood product transfusion are required preoperatively, or the procedure is done as an emergency.

Description and analysis of hand forces in medicine cart pushing tasks

The primary objectives of this study were to describe and analyze the hand force exertion patterns of experienced nursing home nurses and nursing students during dynamic medicine cart pushing tasks in Initial, Sustained, Turning, and Stopping motion phases. A 2 × 2 × 2 factorial experiment was conducted with 22 participants to estimate the effects of lane congestion, precision cart control, and floor surface on horizontal hand forces. Root mean squared (RMS) lane deviation patterns were also described to provide an indicator of cart handling difficulty across the different study conditions. Descriptive statistics revealed that nurses exerted greater mean hand force (10%) and made more (12%) lane deviation than students and that the highest two-hand forces of 147N were measured in the Turning phase on carpet. Strong correlations between work experience group, body mass, and BMI required that force data for nurses and students be collapsed in analytical models where no group differences existed. Predicted pushing forces on carpeted floor surface were significantly greater than on tile in Initial (14N), Sustained (14N) and Turning (18N), except in stopping where pulling forces were 37N lower. High lane congestion predicted significant peak force increases of 4N and 7N in Sustained and Turning, respectively, but decreased by 20N in Initial. High precision control led to significant decreases in two-hand forces that ranged from 4 to 20N across motion phases. Complex interactions among the experimental factors suggest that work environment (lane congestion and floor surface) and work demands (precision control) should be included in the evaluation of pushing tasks and considered prior to making renovations to nursing home environments.

Estimating 3-D L5/S1 moments during manual lifting using a video coding system: validity and interrater reliability

OBJECTIVE

The aim of the study was to investigate the validity and interrater reliability of using a proposed video coding system to estimate the dynamical 3-D L5/ S1 joint moment on the basis of four key frames from video clips of asymmetric lifting tasks.

BACKGROUND

L5/S1 joint loading has been widely adopted to quantify low-back loading during lifting tasks. However, the measurement of L5/S1 joint loading usually requires a laboratory environment, which cannot be applied during field surveys.

METHOD

The validity of this system was investigated by comparing the estimated L5/S1 joint moments of various simulated lifting tasks with motion tracking system-based reference L5/S1 joint moments.

RESULTS

The comparison showed that the video coding system yielded good estimates on peak moment (r = .91, average absolute error [AAE] = 20.3 Nm) and cumulative moment (r = .88,AAE = 22.5 Nm.sec) of the sagittal plane. The interrater reliability of this system was assessed among 10 raters who used this system. The intraclass correlation ranged between .51 and .89 for the moments of different planes.

CONCLUSION

The results of the validity and interrater reliability analyses showed that the proposed video coding system could provide a good estimate of total L5/S1 joint loading on the basis of side-view video clips of the simulated lifting tasks.

APPLICATION

Although it was not as accurate as a motion tracking system for L5/S1 joint loading calculations, this approach can be an alternative for back load estimation for some lifting configurations when the use of motion tracking systems is not possible.

The structure of acyl coenzyme A-cholesterol acyltransferase and its potential relevance to atherosclerosis

Acyl coenzyme A-cholesterol acyltransferase (ACAT) catalyzes the formation of intracellular cholesterol esters. It is present in a variety of tissues and is believed to play significant roles in cholesterol homeostasis. Under pathologic conditions, accumulation of the ACAT reaction product as cytoplasmic cholesterol ester lipid droplets within macrophages and smooth muscle cells is a characteristic feature of early lesions of human atherosclerotic plaques. ACAT is a membrane protein located in the endoplasmic reticulum. Its activity is susceptible to inactivation by detergents, and it has never been purified to homogeneity; no antibodies directed against it have been reported. Through a somatic cell and molecular genetic approach, we have recently succeeded in molecular cloning and functional expression of a human macrophage ACAT cDNA. This cDNA contains an open reading frame of 1650 base pairs encoding an integral membrane protein of 550 amino acids. Protein homology analysis shows that the predicted protein sequence shares short regions of homology with other enzymes involved in the catalysis of acyl adenylate formation with subsequent acyl thioester formation and acyl transfer. The ACAT cDNA will enable the investigation of ACAT biochemistry and molecular biology. It will speed up the design of specific ACAT inhibitors as drugs that may provide more effective therapeutic treatment or prevention of atherosclerosis. In addition, studies on the physiologic roles of ACAT in various tissues can now be undertaken through transgenic animal research.

A novel approach for normalizing the photoreflectance spectrum by using polymer-dispersed liquid crystal

This study developed a novel type of normalization procedure for modulation reflectance spectroscopy experiments to obtain the relative change in the reflectance spectrum, ΔR/R. This technique uses a polymer-dispersed liquid crystal to ensure that the dc component of the signal from the detector remained constant by varying the intensity of the light striking the sample. This method is particularly useful for photoreflectance measurement, which may encounter background problems because of scattered pump light and/or photoluminescence. It does not require a change in the gain of the detector or the use of a variable neutral density filter mounted on a servo-motor.

Comorbidities associated with psoriasis - data from the malaysian psoriasis registry

All around the world, there is growing evidence of the association between psoriasis and comorbidities which increase the risk of cardiovascular disease. This study aims to determine the prevalence of various comorbidities among adult psoriasis patients in Malaysia. A cross-sectional study was conducted among patients in the Malaysian Psoriasis Registry from January 2007 to December 2008. A total of 2,267 adult patients with psoriasis from 13 dermatology centers were included. Prevalence of various comorbidities were: hypertension 25.9%, diabetes mellitus 17.7 %, dyslipidaemia 17.8%, overweight 33.2%, obesity 20.7%, ischaemic heart disease 5.8% and cerebrovascular disease 1.4%. These comorbidities were more prevalent in patients with psoriasis of late-onset and longer duration. Active screening of these comorbidities in all adult psoriasis patients is recommended.

Two linear regression models predicting cumulative dynamic L5/S1 joint moment during a range of lifting tasks based on static postures

Previous studies have indicated that cumulative L5/S1 joint load is a potential risk factor for low back pain. The assessment of cumulative L5/S1 joint load during a field study is challenging due to the difficulty of continuously monitoring the dynamic joint load. This study proposes two regression models predicting cumulative dynamic L5/S1 joint moment based on the static L5/S1 joint moment of a lifting task at lift-off and set-down and the lift duration. Twelve men performed lifting tasks at varying lifting ranges and asymmetric angles in a laboratory environment. The cumulative L5/S1 joint moment was calculated from continuous dynamic L5/S1 moments as the reference for comparison. The static L5/S1 joint moments at lift-off and set-down were measured for the two regression models. The prediction error of the cumulative L5/S1 joint moment was 21 ± 14 Nm × s (12% of the measured cumulative L5/S1 joint moment) and 14 ± 9 Nm × s (8%) for the first and the second models, respectively. Practitioner Summary: The proposed regression models may provide a practical approach for predicting the cumulative dynamic L5/S1 joint loading of a lifting task for field studies since it requires only the lifting duration and the static moments at the lift-off and/or set-down instants of the lift.

Effects of handle orientation and between-handle distance on bi-manual isometric push strength

Hand-handle interface is seldom considered in contemporary upper limb biomechanical analyses of pushing and pulling strength. A laboratory study was designed to examine if handle rotation in the frontal plane (0°-horizontal, 45°, and 90°-vertical), anterior tilt (0°-parallel to the frontal plane, and 15°), and distance between two handles (31 and 48.6 cm) affect pushing strength and subjective rating of handle preference. A special testing station was constructed to elicit upper limb push exertions that involved minimal contribution of the torso and legs. Within the station, four load cells were used to measure the horizontal (forward pushing) and vertical components of the pushing forces. Thirty-one participants performed seated bi-manual pushing strength tests. Comparing to the reference handle configuration (horizontal, straight, and a 31-cm between-handle distance), the 45°-rotated and tilted handles with a 31-cm between-handle distance allowed 6.7% more pushing output, while the horizontal and tilted handles with a 31-cm between-handle distance resulted in 2.8% less. Subjective preference was correlated with normalized pushing strength (r=0.89). Tilted handles, at 45°-rotated and vertical positions received highest subjective ratings of preference among all handle configurations. Men exerted greater pushing strength with the 48.6-cm handle distance while women's capacity was greatest with the 31-cm distance. The results demonstrated that handle rotation and tilt angles affected pushing strength and should be taken into consideration when evaluating or designing pushing tasks.

Assessing manual lifting tasks based on segment angle interpolations

This study investigates the effects of the number of interpolation points on the prediction accuracy of segment angle trajectory during lifting. Ten participants performed various lifting tasks while a motion tracking system recorded their movements. Two-point through ten-point equal time-spaced segment angles extracted from major segment trajectory data captured by the motion tracking system were used to re-generate the whole body lifting motion by using polynomial and cubic spline interpolation methods. The root mean square error (RMSE) between the reference (motion tracking system) and the estimated (interpolation method) segment angle trajectories were calculated to quantify the prediction accuracy. The results showed that the cubic spline interpolation will yield a smaller RMSE value than one based on the polynomial interpolation. While increasing the number of interpolation points can reduce the RMSE of the estimated segment angle trajectories, there was a diminishing advantage in continuing to add interpolation points. A sensitivity analysis suggests that if the estimation of the segment angles at each interpolation point deviates considerably from the real value, and cannot be controlled at a low level (<10 (), the use of higher number of interpolation points will not improve the estimation accuracy.

A novel wearable measurement system for ambulatory assessment of joint loading in the occupational setting

It is know that biomechanical overexposure of the joints is an important cause of occupational injuries. This paper presents a novel wearable measurement system for automated assessment of joint loading in the occupational setting. The wearable measurement system consists of a full body inertial sensor motion capture system which can be worn under the clothes and shoes instrumented with 3D force sensors (ForceShoes). Promising results have been found for the performance of the inertial sensor system and the ForceShoe, separately. Validation experiments are in preparation in which the performance of the combined measurements system will be tested in the laboratory by comparing the assessed joint loading to the joint loading assessed by a conventional state-of-the-art lab-based method.

Comparison of different methods to extract the required coefficient of friction for level walking

The required coefficient of friction (RCOF) is an important predictor for slip incidents. Despite the wide use of the RCOF there is no standardised method for identifying the RCOF from ground reaction forces. This article presents a comparison of the outcomes from seven different methods, derived from those reported in the literature, for identifying the RCOF from the same data. While commonly used methods are based on a normal force threshold, percentage of stance phase or time from heel contact, a newly introduced hybrid method is based on a combination of normal force, time and direction of increase in coefficient of friction. Although no major differences were found with these methods in more than half the strikes, significant differences were found in a significant portion of strikes. Potential problems with some of these methods were identified and discussed and they appear to be overcome by the hybrid method.

PRACTITIONER SUMMARY

No standard method exists for determining the required coefficient of friction (RCOF), an important predictor for slipping. In this study, RCOF values from a single data set, using various methods from the literature, differed considerably for a significant portion of strikes. A hybrid method may yield improved results.

Estimation of 3-D peak L5/S1 joint moment during asymmetric lifting tasks with cubic spline interpolation of segment Euler angles

Previous research proposed a method using interpolation of the joint angles in key frames extracted from a field-survey video to estimate the dynamic L5/S1 joint loading for symmetric lifting tasks. The advantage of this method is that there is no need to use unwieldy equipment for capturing full body movement for the lifting tasks. The current research extends this method to asymmetric lifting tasks. The results indicate that 4-point cubic spline interpolation of segment Euler angles combined with a biomechanical model can provide a good estimation of 3-D peak L5/S1 joint moments for asymmetric lifting tasks. The average absolute error in the coronal, sagittal, and transverse planes with respect to the local pelvis axes was 16Nm, 22Nm, and 11Nm, respectively. It was also found that the dynamic component of the peak L5/S1 joint moment was not monotonously convergent when the number of interpolation points was increased. These results can be helpful for developing applied ergonomic field-survey tools such as video bases systems for estimating L5/S1 moments of manual materials handling tasks.

Stochastic distribution of the required coefficient of friction for level walking--an in-depth study

This study investigated the stochastic distribution of the required coefficient of friction (RCOF) which is a critical element for estimating slip probability. Fifty participants walked under four walking conditions. The results of the Kolmogorov-Smirnov two-sample test indicate that 76% of the RCOF data showed a difference in distribution between both feet for the same participant under each walking condition; the data from both feet were kept separate. The results of the Kolmogorov-Smirnov goodness-of-fit test indicate that most of the distribution of the RCOF appears to have a good match with the normal (85.5%), log-normal (84.5%) and Weibull distributions (81.5%). However, approximately 7.75% of the cases did not have a match with any of these distributions. It is reasonable to use the normal distribution for representation of the RCOF distribution due to its simplicity and familiarity, but each foot had a different distribution from the other foot in 76% of cases.

PRACTITIONER SUMMARY

The stochastic distribution of the required coefficient of friction (RCOF) was investigated for use in a statistical model to improve the estimate of slip probability in risk assessment. The results indicate that 85.5% of the distribution of the RCOF appears to have a good match with the normal distribution.

The effect of transverse shear force on the required coefficient of friction for level walking

OBJECTIVE

An enhanced methodology to extract the required coefficient of friction (RCOF) value was used to investigate the effects of the transverse shear component of the ground reaction force (GRF) on the RCOF.

BACKGROUND

The RCOF is an important indicator for slip incidents. However,the extraction of the RCOF from GRF is not standardized. The transverse shear force is usually ignored in calculating the RCOF value.

METHOD

For this study, 40 participants performed four walking conditions. The RCOF values both with (RCOF2) and without (RCOF1) the transverse shear force were identified from each strike by the use of an enhanced method and were compared.

RESULTS

A total of 24,851 strikes were collected. The transverse component increased the RCOF value by more than 10% in 7.2% of the strikes. In 10.4% of the strikes, the RCOF2 occurred at least 20 ms earlier and the RCOF value was on average 8.9% larger than RCOF1.

CONCLUSION

With this method, we were able to successfully identify the RCOF in a significantly large number of strikes across 40 participants. In a portion of the strikes, the transverse shear force increased the RCOF significantly. In a significant portion of the strikes, the RCOF2 occurred much earlier than RCOF1.

APPLICATION

Better estimates of the RCOF magnitude and instant of occurrence could potentially improve risk assessment and identification of critical instants in gait.

The validity and interrater reliability of video-based posture observation during asymmetric lifting tasks

OBJECTIVE

The objective was to evaluate the validity and interrater reliability of a video-based posture observation method for the major body segment angles during asymmetric lifting tasks.

BACKGROUND

Observational methods have been widely used as an awkward-posture assessment tool for ergonomics studies. Previous research proposed a video-based posture observation method with estimation of major segment angles during lifting tasks. However, it was limited to symmetric lifting tasks. The current study extended this method to asymmetric lifting tasks and investigated the validity and the interrater reliability.

METHOD

Various asymmetric lifting tasks were performed in a laboratory while a side-view video camera recorded the lift, and the body segment angles were measured directly by a motion tracking system. For this study, 10 raters estimated seven major segment angles using a customized program that played back the video recording, thus allowing users to enter segment angles. The validity of estimated segment angles was evaluated in relation to measured segment angles. Interrater reliability was assessed among the raters.

RESULTS

For all the segment angles except trunk lateral bending, the estimated segment angles were strongly correlated with the measured segment angles (r > .8), and the intraclass correlation coefficient was greater than 0.75.

CONCLUSION

The proposed observational method was able to provide a robust estimation of major segment angles for asymmetric lifting tasks based on side-view video clips. The estimated segment angles were consistent among raters.

APPLICATION

This method can be used for assessing posture during asymmetric lifting tasks. It also supports developing a video-based rapid joint loading estimation method.

Routine drainage is not necessary after laparoscopic gastric bypass

INTRODUCTION

Routine intra-abdominal drainage has been recommended for detecting surgical complications, such as anastomotic leaks or intra-abdominal hemorrhage, after laparoscopic gastric bypass for morbid obesity. The aim of this study was to determine whether routine drainage after laparoscopic gastric bypass is indeed necessary.

METHODS

Patients undergoing laparoscopic gastric bypass with intra-abdominal drainage (D-group) were compared with those without drainage (N-group) in a retrospective study. The main outcome measures were postoperative course and complications.

RESULTS

No differences were observed in the postoperative complications. Both groups had one major complication of leakage (1/90, 1.1%). Minor complications occurred in six D-group patients (6/90, 6.7%) and eight N-group patients (8/90, 8.9%) (P=0.578). No difference was observed in postoperative analgesic dose usage (mean ± SD: 63 ± 37 mg vs 60 ± 31 mg; P=0.963) or length of stay hospital (5.2 ± 2.6 d vs 4.7 ± 1.8 d; P=0.135). However, the N-group had a shorter time to flatus passage compared to the D-group (1.6 ± 0.7 d vs 1.2 ± 0.5 d; P=0.006).

CONCLUSION

Routine abdominal drainage is not necessary after a successful laparoscopic gastric bypass for morbidly obese patients. Drainage omission may contribute to a quicker recovery without additional surgical complications.

Prediction accuracy in estimating joint angle trajectories using a video posture coding method for sagittal lifting tasks

This study investigated prediction accuracy of a video posture coding method for lifting joint trajectory estimation. From three filming angles, the coder selected four key snapshots, identified joint angles and then a prediction program estimated the joint trajectories over the course of a lift. Results revealed a limited range of differences of joint angles (elbow, shoulder, hip, knee, ankle) between the manual coding method and the electromagnetic motion tracking system approach. Lifting range significantly affected estimate accuracy for all joints and camcorder filming angle had a significant effect on all joints but the hip. Joint trajectory predictions were more accurate for knuckle-to-shoulder lifts than for floor-to-shoulder or floor-to-knuckle lifts with average root mean square errors (RMSE) of 8.65 degrees , 11.15 degrees and 11.93 degrees , respectively. Accuracy was also greater for the filming angles orthogonal to the participant's sagittal plane (RMSE = 9.97 degrees ) as compared to filming angles of 45 degrees (RMSE = 11.01 degrees ) or 135 degrees (10.71 degrees ). The effects of lifting speed and loading conditions were minimal. To further increase prediction accuracy, improved prediction algorithms and/or better posture matching methods should be investigated. STATEMENT OF RELEVANCE: Observation and classification of postures are common steps in risk assessment of manual materials handling tasks. The ability to accurately predict lifting patterns through video coding can provide ergonomists with greater resolution in characterising or assessing the lifting tasks than evaluation based solely on sampling with a single lifting posture event.

Leucinopine, a characteristic compound of some crown-gall tumors

An unusual compound has been found in crowngall tumors induced by those Agrobacterium tumefaciens strains that utilize neither octopine nor nopaline. The compound has been isolated and shown by proton and carbon-13 NMR spectroscopy and by synthesis to be N(2)-(1,3-dicarboxypropyl)-L-leucine, which also exists in a cyclized (i.e., lactam) form. This compound, which we name "leucinopine," was not detected in octopine tumors, nopaline tumors, or the tumors induced by A. tumefaciens strains 181 and EU6.

Ornitholimnology: Effects of grazing by the Andean flamingo (Phoenicoparrus andinus)

Experimental exclusion of the Andean flamingo (Phoenicoparrus andinus) from shallow water areas of a salt lake in the Bolivian Andes caused large increases in the biomass of microorganisms inhabiting the surface sediments, especially a large diatom (Surirella wetzeli), amebas, ciliates, and nematodes. This is a conservative demonstration of the influences that water birds in general exert on the structure of aquatic ecosystems.

The analysis of decomposition methods for support vector machines

The support vector machine (SVM) is a new and promising technique for pattern recognition. It requires the solution of a large dense quadratic programming problem. Traditional optimization methods cannot be directly applied due to memory restrictions. Up to now, very few methods can handle the memory problem and an important one is the "decomposition method." However, there is no convergence proof so far. In this paper, we connect this method to projected gradient methods and provide theoretical proofs for a version of decomposition methods. An extension to bound-constrained formulation of SVM is also provided.We then show that this convergence proof is valid for general decomposition methods if their working set selection meets a simple requirement.

Synergistic growth inhibition of anaplastic large cell lymphoma cells by combining cellular ALK gene silencing and a low dose of the kinase inhibitor U0126

Abnormal expression of anaplastic lymphoma kinase (ALK) gene is an important pathogenic factor for anaplastic large cell lymphoma (ALCL). To study the function of ALK, an inducible short hairpin RNA (shRNA) system was stably introduced into cultured human ALCL cells. Inducing shRNA expression in the generated cells resulted in cellular ALK gene silencing and led to inactivation of multiple signaling pathways and growth arrest. Interestingly, a combination of ALK gene silencing with U0126, a kinase inhibitor specific for the extracellular signal-regulated kinases 1/2 pathway, resulted in an augmented reduction in cellular JunB expression. Functional studies indicated that combining ALK gene silencing with U0126 treatment provided a synergistic growth inhibition, which occurred faster and was more profound than with either treatment alone. This synergistic effect was also observed when measuring cell proliferation, apoptosis, and in vitro cell colony formation. Importantly, the combination of ALK gene silencing and U0126 had a prolonged inhibitory effect, preventing recovery of ALCL cell growth even after treatments were removed. Moreover, this synergistic inhibitory effect was confirmed in vivo using a mouse model with xenografted ALCL tumors. Our findings indicate that combining cellular ALK gene silencing with a low dose of U0126 may prove to be an effective and more specific therapeutic approach to treating ALCL.

Effects of simulated occupational task parameters on balance

The effects of single-handed load holding, length of the base of support, and standing surface condition (narrow and wide construction beams) on balance were investigated in twenty-three healthy men between the ages of 18 and 55 years old. Balance during quiet standing was evaluated from postural sway measurements derived from center of pressure (COP) displacement. These measurements included the range or maximal displacement of the COP in the anteroposterior (AP) and mediolateral (ML) directions, the elliptical area, and mean sway velocity. Holding a load in the hand did not significantly affect postural sway measures (p > 0.05), although the effect of surface condition was significant on all COP measures (p < 0.001). Lengthening the base of support did not affect the ranges or elliptical area, but increased the mean velocity of sway (p = 0.001). Changes in the dimensional characteristics of the surface condition and length of base of support affected postural sway, possibly by requiring adjustments to balance and motor control strategies. Further research is required to determine if these changes are detrimental to maintaining balance and increase the risk of falls for workers in similar environments.

N-3 vs. saturated fatty acids: effects on the arterial wall

Cardiovascular disease is a leading cause of death worldwide. Atherosclerosis and unstable plaques are underlying causes for cardiovascular diseases. Cardiovascular disease is associated with consumption of diets high in saturated fats. In contrast there is increasing evidence that higher intakes of dietary n-3 fatty acids decrease risk for cardiovascular disease. Recent studies are beginning to clarify how n-3 compared with saturated fatty acids influence cardiovascular disease risk via pathways in the arterial wall. In this paper we will review studies that report on mechanisms whereby dietary fatty acids affect atherosclerosis through modulation of arterial wall lipid deposition, inflammation, cell proliferation, and plaque vulnerability.

Towards a combined prognostic index for survival in HIV infection: the role of 'non-HIV' biomarkers

BACKGROUND

As those with HIV infection live longer, 'non-AIDS' condition associated with immunodeficiency and chronic inflammation are more common. We ask whether 'non-HIV' biomarkers improve differentiation of mortality risk among individuals initiating combination antiretroviral therapy (cART).

METHODS

Using Poisson models, we analysed data from the Veterans Aging Cohort Study (VACS) on HIV-infected veterans initiating cART between 1 January 1997 and 1 August 2002. Measurements included: HIV biomarkers (CD4 cell count, HIV RNA and AIDS-defining conditions); 'non-HIV' biomarkers (haemoglobin, transaminases, platelets, creatinine, and hepatitis B and C serology); substance abuse or dependence (alcohol or drug); and age. Outcome was all cause mortality. We tested the discrimination (C statistics) of each biomarker group alone and in combination in development and validation data sets, over a range of survival intervals, and adjusting for missing data.

RESULTS

Of veterans initiating cART, 9784 (72%) had complete data. Of these, 2566 died. Subjects were middle-aged (median age 45 years), mainly male (98%) and predominantly black (51%). HIV and 'non-HIV' markers were associated with each other (P < 0.0001) and discriminated mortality (C statistics 0.68-0.73); when combined, discrimination improved (P < 0.0001). Discrimination for the VACS Index was greater for shorter survival intervals [30-day C statistic 0.86, 95% confidence interval (CI) 0.80-0.91], but good for intervals of up to 8 years (C statistic 0.73, 95% CI 0.72-0.74). Results were robust to adjustment for missing data.

CONCLUSIONS

When added to HIV biomarkers, 'non-HIV' biomarkers improve differentiation of mortality. When evaluated over similar intervals, the VACS Index discriminates as well as other established indices. After further validation, the VACS Index may provide a useful, integrated risk assessment for management and research.

Anti-tumor activity of histone deacetylase inhibitors and the effect on ATP-binding cassette in ovarian carcinoma cells

INTRODUCTION

Ovarian cancer is of worldwide importance, and has a significantly high mortality rate due to therapy failure. Drug resistance might be one of most importance factors. Histone deacetylase inhibitors (HDACi) have been reported to be a new class of promising anti-tumor agents, thus this study aimed to investigate the effect of HDAC on the chemo-resistance genes of human ovarian carcinoma cell lines.

METHODS

The expressions of ATP binding cassette (ABC) transporter genes, multidrug-resistant protein (MDR1) and multidrug resistance-associated proteins (MRP1 and 2) of ovarian cancer cell lines OC-109 and SK-OV-3 after HDACi treatment were determined.

RESULTS

HDACi, including sodium butyrate (NaB), suberoylanilide hydroxamic acid (SAHA) and trichostatin A (TSA) reduced ovarian cancer cell viability from 4.4% to 68.8%, in both dose- and time-dependent manners. The effect of HDACi on MDR1, MRP1, and MRP2 showed induced expression of MDR1 mRNA, but reduced mRNA expression of MRP1 and MRP2.

CONCLUSIONS

The effect of HDACi on the reduced viability of ovarian cancer cell lines, concomitant with the induced expression of MDR1 and reduced expression of MRP1 and 2, might provide additional benefits in the management of ovarian cancers in the future.

Ovarian carcinomatosis presenting as bilateral inguinal hernia: a brief report

The differential diagnosis for what may seem an inguinal hernia may be complex, as lateral pain may be of many types of origin. We report the case of a 48-year-old female patient who presented with a history of painful, progressively protruding soft bulging masses over the bilateral inguinal area and a 20-year history of head cancer and hepatitis B virus. Pathological analysis, gynecological ultrasound and abdominal computed tomography scan were required to make final determination. Final diagnosis was Stage IV ovarian carcinomatosis, which responded to chemotherapy. Initial diagnosis of inguinal hernia should not rule out other potential diagnoses, particularly in complex cases with other risk factors.

The anatomy of a slip: Kinetic and kinematic characteristics of slip and non-slip matched trials

To improve understanding of slip propagation mechanisms, one could compare features of early stance phase during slips and non-slips. This study investigated the similarities and differences in kinematics and utilized COF of paired trials, defined as a matched pair of slip and non-slip trials produced by the same participant walking on the same floor condition at the same walking speed condition. Twenty-two participants produced 47 matched trial pairs while walking at 1.5, 1.8 and 2.1m/s, over a forceplate with an available COF ranging from 0.12 to 0.21. Heel displacement was captured with an infrared motion tracking system and utilized COF was derived from ground reaction forces. ANOVA revealed no significant differences between the slip and non-slip groups in horizontal heel velocity just prior to heel strike or for heel velocity or slip distance during the 20ms period following heel strike. Significant differences were found between the groups in utilized COF and horizontal heel velocity at 25 and 30ms following heel strike. Differences in heel kinematics and kinetics during early stance phase between the slip and non-slip trials are discussed. The results differ from several previous studies, likely due to methodological differences, as the present study was conducted on marginally slippery surfaces, as opposed to very low COF conditions with thick contaminant layers.

High-resolution spectroscopy of Lambda16N by electroproduction

An experimental study of the (16)O(e,e'K(+))(Lambda)(16)N reaction has been performed at Jefferson Lab. A thin film of falling water was used as a target. This permitted a simultaneous measurement of the p(e,e'K(+))Lambda, Sigma(0) exclusive reactions and a precise calibration of the energy scale. A ground-state binding energy of 13.76+/-0.16 MeV was obtained for (Lambda)(16)N with better precision than previous measurements on the mirror hypernucleus (Lambda)(16)O. Precise energies have been determined for peaks arising from a Lambda in s and p orbits coupled to the p(1/2) and p(3/2) hole states of the (15)N core nucleus.

A study of particulates and metallic element concentrations in temple

Concentrations of ambient suspended particulates were measured at Tzu Yun Yen temple in Taiwan (120 degrees , 34', 46.2''E, 24 degrees , 16', 17.1''N), where semi-open incense burning is characteristic. Many pilgrims from different areas with various beliefs visit the temple and burn incense. Samples were collected with a universal sampler used for measuring suspended particulate concentrations. Sampling period was from August 8, 2006, to October 6, 2006. The average PM(10) concentrations measured at the temple were 16% higher than 125 microg/m(3) (this value is the outdoor air quality standard according to Taiwan Environmental Protection Administration (EPA)). In coarse particulates (PM(2.5-10)), the mean metallic elements concentrations are in the order of Ca>Mg>Zn>Fe>Mn>Cr>Cu>Pb during weekend and weekday sampling. In addition, the fine particulates (PM(2.5)) mean metallic elements concentrations are in the order of Ca>Mg>Fe>Zn>Cr>Mn>Pb>Cu during weekend sampling and Ca>Fe>Mg>Zn>Cr>Mn>Pb>Cu during weekday sampling.

Cognitive deficits in multiple system atrophy correlate with frontal atrophy and disease duration

BACKGROUND AND PURPOSE

Dementia remains an exclusion criterion in diagnosing multiple system atrophy (MSA). This study aimed to determine the cognitive changes and brain atrophy patterns in the Parkinsonian (MSA-P) and cerebellar (MSA-C) variants of MSA.

METHODS

Voxel-based morphometry (VBM) of magnetic resonance imaging (MRI) and neuro-psychological tests were applied to 10 MSA-C and 13 MSA-P patients, and compared to 37 age-matched controls. Correlation analyses were performed between cognitive test results and morphometric data extracted from the VBM data.

RESULTS

In neuro-psychological testing, the 23 MSA patients scored lower in the Stroop interference test and took longer in the trail-making test as compared with the controls, whereas MSA-C performed worse than MSA-P in the memory scores, Stroop test, and time to complete the trail-making test. MSA, as a group, showed atrophy in the cerebellum, insular cortex, fusiform gyrus, inferior orbito-frontal gyrus, superior temporal gyrus, and caudate nucleus. Memory scores correlated well with pre-frontal lobe atrophy but not in the insular area.

CONCLUSION

In conclusion, although dementia is not a typical presenting feature of MSA and is regarded as a sub-cortical movement disorder, frontal atrophy, cognitive changes, and dementia are identifiable as MSA progresses.

Assessment of dose rate scaling factors used in NCTPlan treatment planning code for the BNCT beam of THOR

Tsing Hua open-pool reactor (THOR) at Tsing Hua University in Taiwan has been used to investigate the feasibility and to enhance the technology of boron neutron capture therapy (BNCT) for years. A rebuilt epithermal beam port for BNCT at THOR was finished in the summer of 2004, and then researches and experiments were performed to hasten the first clinical treatment case of BNCT in Taiwan in the near future. NCTPlan, a Monte Carlo-based clinical treatment planning code, was used to calculate the dose-rate distributions of BNCT in this work. A self-made Snyder head phantom with a servo-motor control system was irradiated in front of the THOR BNCT beam exit. The phantom was made from a 3mm shell of quartz wool impregnated with acrylic casting resin mounted on an acrylic base, and was filled with water. Gold foils (bare and cadmium-covered) and paired ion chambers (one with graphite wall and filled with CO(2) gas, another with A-150 plastic tissue equivalent wall and filled with tissue equivalent gas) were placed inside the Snyder phantom to measure and estimate the depth-dose distributions in the central axis of the beam. Dose components include the contribution of thermal neutrons, fast neutrons, photons and emitted alpha particles from (10)B(n,alpha)(7)Li reaction. Comparison and analysis between computed and measured results of depth-dose distributions were made in this work. Dose rate scaling factors (DRSFs) were defined as normalization factors derived individually for each dose component in the BNCT in-phantom radiation field that provide the best agreement between measured and computed data. This paper reports the in-phantom calculated and experimental dosimetry and the determined DRSFs used in NCTPlan code for the BNCT beam of THOR.

High-pressure needle interface for thermoplastic microfluidics

A robust and low dead volume world-to-chip interface for thermoplastic microfluidics has been developed. The high pressure fluidic port employs a stainless steel needle inserted into a mating hole aligned to an embedded microchannel, with an interference fit used to increase pressure resistance. Alternately, a self-tapping threaded needle screwed into a mating hole is also demonstrated. In both cases, the flat bottom needle ports seat directly against the microchannel substrate, ensuring low interfacial dead volumes. Low dispersion is observed for dye bands passing the interfaces. The needle ports offer sufficient pull-out forces for applications such as liquid chromatography that require high internal fluid pressures, with the epoxy-free interfaces compatible with internal microchannel pressures above 40 MPa.

Is planned surgery important in sinonasal inverted papilloma?

OBJECTIVE

To evaluate which clinical characteristics of inverted papilloma (IP) can result easily in misdiagnosis by clinicians and to determine the recurrence rate of inverted papilloma depending on diagnosis confirmation pre-operatively, intra-operatively or post-operatively.

PATIENTS AND METHODS

Fifty-one patients were treated for IP and 47 patients attended regular post-operative follow-up appointments for at least one year (mean: 54 months).

RESULTS

The patients were assigned to 3 groups: group Ia, in which IP was not confirmed until the post-operative pathology findings; group Ib, in which IP was confirmed during the operation; and group II, in which IP was confirmed before the operation. There were nineteen (37%) patients in group Ia, nine patients (18%) in group Ib and twenty-three patients (45%) in group II. The recurrence rates for groups Ia, Ib and II were 33%, 11% and 5% respectively.

CONCLUSIONS

The initial presentation of bilateral sinonasal disease can easily lead the doctor into the misdiagnosis of IP. Bony erosion, remodelling, and a widening of the natural orifice of the sinuses on a CT scan are useful signs indicating IP. The correct diagnosis prior to surgery is a determinant of outcome. The use of frozen sections should, however, improve outcome as well. In this study we highlight the high prevalence and relatively low control rate of misdiagnosed IP (pathology undetermined pre-operatively) and hope to remind clinicians that early recognition of the tumour is most beneficial to patients.

Visually based perceptions of slipperiness: underlying cues, consistency and relationship to coefficient of friction

If walkers can anticipate surface conditions, they can adjust their gait to help reduce the risk of a slip. This study investigated visual cues to slipperiness. Thirty-one participants made visually based judgements about 37 different floor surfaces. These judgements included ratings of slipperiness, reflectiveness, texture, traction, light/dark, likelihood of slipping, cautious intent as well as relative slipperiness. Correlational and regression analyses indicated that while reflectiveness is the predominant visual cue in forming judgements of slipperiness (r = 0.73; p < 0.05), texture and traction were also highly correlated with perceived slipperiness. Furthermore, participants were consistent in slipperiness judgements over time (r = 0.76; p < 0.05) and response measures and a significant relationship was observed between visual cues and coefficient of friction (COF) (r ranged from 0.16 to 0.58; all p < 0.05). Subjective ratings and measured COF, taken as a composite measure of slipperiness, may provide safety professionals with an improved indicator of 'higher risk' surface conditions. The results indicate that people rely on visual cues to judge slipperiness, that they do so consistently and that subjective ratings are related to measured COF. These results have implications for the measurement of slipperiness as well as the design of floor surfaces to be protective against slips and falls.

The effect of contact area on friction measured with the portable inclinable articulated strut slip tester (PIAST)

A portable inclinable articulated strut slip tester (PIAST) measures friction at the shoe and floor interface. The squeeze-film effect with the PIAST is excessive in representing a human strike. The goal of this study was to investigate the effect of the contact area size on friction for reducing the squeeze-film effect. The footwear pad area of this slip meter was sequentially reduced from 7.62 cm square to 2.54 cm square. Five walkways were constructed. Friction was measured on each walkway under three surface conditions. Thirty-five participants rated their perceptions of slipperiness. The results indicated that the friction increased and plateaued as the size of the contact area was reduced. The effect of the pad size on the friction coefficient was statistically significant. The correlation coefficients between the friction and perception rating did not give a clear indication of what pad size might have a better correlation with human perception. Friction measurement at the shoe and floor interface is a critical issue in assessing potential interventions and identifying potentially dangerous locations for slip and fall incidents. This paper addresses a potential improvement in measuring friction on liquid-contaminated floor surfaces.

A methodology to quantify the stochastic distribution of friction coefficient required for level walking

The required friction coefficient is defined as the minimum friction needed at the shoe and floor interface to support human locomotion. The available friction is the maximum friction coefficient that can be supported without a slip at the shoe and floor interface. A statistical model was recently introduced to estimate the probability of slip and fall incidents by comparing the available friction with the required friction, assuming that both the available and required friction coefficients have stochastic distributions. This paper presents a methodology to investigate the stochastic distributions of the required friction coefficient for level walking. In this experiment, a walkway with a layout of three force plates was specially designed in order to capture a large number of successful strikes without causing fatigue in participants. The required coefficient of friction data of one participant, who repeatedly walked on this walkway under four different walking conditions, is presented as an example of the readiness of the methodology examined in this paper. The results of the Kolmogorov-Smirnov goodness-of-fit test indicated that the required friction coefficient generated from each foot and walking condition by this participant appears to fit the normal, log-normal or Weibull distributions with few exceptions. Among these three distributions, the normal distribution appears to fit all the data generated with this participant. The average of successful strikes for each walk achieved with three force plates in this experiment was 2.49, ranging from 2.14 to 2.95 for each walking condition. The methodology and layout of the experimental apparatus presented in this paper are suitable for being applied to a full-scale study.

Slipping of the foot on the floor when pulling a pallet truck

Workers pulling pallet trucks are likely to slip when pulling and stepping on a low-friction floor. This study investigated the slipping of male participants when pulling a pallet truck, walking backward, and stepping on either a dry, wet, or glycerol-contaminated vinyl surface. The weight of the load on the truck was either low (0 kg), medium (295 kg), or high (568 kg). A motion-tracking system was used to collect the three-dimensional coordinates of the markers on the shoes. It was found that subjects might slip either upon landing of the leading foot on the toe (slip I) or before taking off of the lagging foot on the heel (slip II). The results indicated that the slip distances for both types of slip were significantly affected by the load and surface conditions and their interactions. Micro-slips (slips between 0.1 and 3 cm) and midi-slips (slips between 3 and 10 cm) were more common in slip I than in slip II. On glycerol-contaminated surfaces, the probabilities of a slide, or a slip more than 10 cm, for both slips I and II were over 40%. The implications of the results were discussed.

Validation of a three-dimensional hand scanning and dimension extraction method with dimension data

A three-level experiment was developed to validate a 3-D hand scanning and dimension extraction method with dimension data. At the first level, a resin hand model of a participant was fabricated to test the repeatability of the dimension data obtained by the 3-D method. At the second level, the actual hand of that participant was measured repeatedly using both the 3-D method and the traditional manual measurement method. The repeatability for both methods was investigated and compared. The influence of posture keeping, surface deformation and other human issues were also examined on the second level. At the third level, a group of participants were recruited and their hands were measured using both methods to examine any differences between the two methods on statistical descriptives. Significant differences, which varied among dimension types (length, depth/breadth, and circumference), were found between the 3-D method and the traditional method. 3-D anthropometric measurement and dimension extraction has become a prospective technology. The proposed three-level experiment provides a systematic method for validation of the repeatability of a 3-D method and compatibility between dimension data from a 3-D method and a traditional method.

Rearward movement of the heel at heel strike

This paper describes the observation of rearward movement (RM) of the heel following heel strike occurring during normal gait. Thirty-one participants recruited as part of a larger study on slip kinematics walked the length of an 8-m runway at a speed of 1.5 m/s. Several floor surfaces, presented dry and with contaminant, were used for the purpose of eliciting a wide range of small slip distances. The normal force applied to a forceplate mounted in the runway was used to identify heel strike, as well as to calculate the utilized coefficient of friction during early stance phase. A motion analysis system tracked the displacement of two heel-mounted markers, and the data were used to derive kinematic variables related to the heel strike event. Results showed that RMs occurred in 18.1% of 494 trials, with a mean rearward displacement of 5.02 (+/-3.68) mm. When present, RMs occurred in close temporal proximity to heel strike, typically completing RM within 40 ms of the heel strike event. When divided into groups by age, older participants (>40 years) were more than twice as likely to have RMs as younger participants. When grouped by height or weight, differences in the proportion of trials with RMs were small. In trials where RMs were observed, forward slip distances were significantly less than for trials with no RMs, 2.17 (+/-3.87) mm vs. 12.58 (+/-10.71) mm, respectively. The time until the heel stopped moving during the post-heel strike period was not significantly different between RM and non-RM trials. Further investigation of this gait feature may improve understanding of normal gait patterns and may have implications for future slipmeter development.

Quark-hadron duality in neutron (3He) spin structure

We present experimental results of the first high-precision test of quark-hadron duality in the spin-structure function g_{1} of the neutron and 3He using a polarized 3He target in the four-momentum-transfer-squared range from 0.7 to 4.0 (GeV/c);{2}. Global duality is observed for the spin-structure function g_{1} down to at least Q;{2}=1.8 (GeV/c);{2} in both targets. We have also formed the photon-nucleon asymmetry A1 in the resonance region for 3He and found no strong Q2 dependence above 2.2 (GeV/c);{2}.