Volume Work Research Articles

Results of the 2015 Perfusionist Salary Study

Presently, there exists no published valid and reliable salary study of clinical perfusionists. The objective of the 2015 Perfusionist Salary Study was to gather verifiable employee information to determine current compensation market rates (salary averages) of clinical perfusionists working in the United States. A salary survey was conducted between April 2015 and March 2016. The survey required perfusionists to answer questions about work volume, scheduling, and employer-paid compensation including benefits. Participants were also required to submit a de-identified pay stub to validate the income they reported. Descriptive statistics were calculated for all survey questions (e.g., percentages, means, and ranges). The study procured 481 responses, of which 287 were validated (i.e., respondents provided income verification that matched reported earnings). Variables that were examined within the validated sample population include job title, type of institution of employment, education level, years of experience, and geographic region, among others. Additional forms of compensation which may affect base compensation rates were also calculated including benefits, call time, bonuses, and pay for ancillary services (e.g., extracorporeal membrane oxygenation and ventricular assist device). In conclusion, in 2015, the average salary for all perfusionists is $127,600 with 19 years' experience. This research explores the average salary within subpopulations based on other factors such as position role, employer type, and geography. Information from this study is presented to guide employer compensation programs and suggests the need for further study in consideration of attrition rates and generational changes (i.e., perfusionists reaching retirement age) occurring alongside the present perfusionist staffing shortage affecting many parts of the country.

Arthur Bispo do Rosario além dos muros da Colônia

Resumo Este trabalho propõe um olhar sobre a obra de Arthur Bispo do Rosario, que secundariza a patologia e prioriza o vivido. É frequente o cotejamento com Marcel Duchamp por conta da similaridade formal sustentada por algumas de suas obras. Mas a heterogeneidade dos percursos desafia a recepção a uma reflexão mais detida sobre suas respectivas experiências. Em Arthur Bispo do Rosario, a condição de recluso notadamente incorre em fortes restrições materiais e contextualiza a obra. Em seu inventivo e inusitado projeto, funda tanto menos uma estética da feiura e tanto mais - por sua força de verdade - o belo artístico, não como lei formal e plástica, mas como resultado ou êxito de uma experiência estética que se torna experiência artística. Espera-se adotar um ponto de vista que, prescindindo dos caminhos usuais - como a reincidente aproximação entre esses dois artistas -, busque ver além dos limites discerníveis do volume das obras, evidenciando uma verdade interposta como “quase-sujeitos”, nos termos de Georges Didi-Huberman. Examinar a obra têxtil de Arthur Bispo do Rosario pelos vãos da percepção é assumir sua indeterminação e considerá-la na categoria de instável a que pertencem os objetos de arte mediadores de realidades vividas. Evidenciar sua magnitude é também evidenciar sua importância como um possível instrumento de descontaminação e despreconceitualização do olhar que categoriza e penaliza artistas e obras, diagnosticando-as.

Identification of geometric deviations inherent to multi-axis machine tools based on the pose measurement principle

The laser tracker is an effective instrument for measuring 3D relative displacement in a work volume because its attitude can be freely changed. This paper presents a novel principle to realize the precise calibration of a numerical control (NC) machine tool accurately and quickly; this is the ‘pose measurement principle’, for measuring errors. We also introduce an algorithm for identifying geometric deviations. A NC precise table mounted on a motion axis and a laser tracker are used for the coordinate determination of three fixed points to obtain the pose information of each motion axis, then calculate the pose deviations, and finally identify all the errors. For the error identification, first, according to the definition of geometric errors, we extend the concept of pose deviations, and represent the six geometric errors using a position deviation vector and attitude deviation vector. Next, we geometrically identify the three angular errors and linear errors in order; the error mathematical model for the linear axis and rotary axis are developed, respectively. Moreover, the validity of the calibration algorithm for the base station, measuring points and identification of errors are confirmed by simulations. In the end, the proposed method is applied to a three-axis NC milling machine tool and a rotary table, and then the geometric deviations are identified successfully in 3 h and 2.5 h, respectively. Comparative experiments by means of other instruments also agree well with the proposed method. Thus, the proposed method can be applied to the measurement of the multi-axis machine tool.

European Journal of Work and Organizational Psychology Volume 25, 2016, List of Reviewers

European Journal of Work and Organizational Psychology Volume 25, 2016, List of Reviewers

Mathematical Modelling and Scale-up of Batch Fermentation with Burkholderia cepacia B27 Using Vegetal Oil as Carbon Source to Produce Polyhydroxyalkanoates

A mathematical model that predicts biomass growth and polyhidroxyalkanoates (PHAs) accumulation in Burkholderia cepacia B27 and its validation at pilot plant scale is presented in this work. During the fermentation process, the mutated strain was capable to produce 15 g/L of PHA and accumulate 86 % of bacteria weight as polymer, with corn oil as carbon source. Bioreactor assays were performed with a 5 L working volume, pH 7.0 and 32 °C. The model development steps were the following: 1) kinetic behavior analysis; 2) formulation of differential equations to predict kinetic behavior; 3) fitting of model parameters with Matlab® solvers, and 4) model validation with statistical and experimental tests. The experimental validation was developed under batch conditions with a work volume of 60 L, showing a good prediction of the system behavior. This model will be useful for the optimization of the feed-batch process that is the next step in the research.

Shifting the pulsatility by increasing the change in rotational speed for a rotary LVAD using a native heart load control system.

We have previously developed a native heart load control system for a continuous-flow left ventricular assist device (LVAD) ((EVAHEART®; Sun Medical) and demonstrated that the rotational speed (RS) in synchronization with the cardiac cycle can alter pulsatility and left ventricular (LV) load under general anesthesia. In this study, we assessed the effects of different levels of increase in RS on pulsatility and LV load in the chronic awake phase. We implanted the EVAHEART via left thoracotomy in 7 normal goats (59.3±4.6kg). Two weeks after implantation, we examined the effects of co-pulse mode (increased RS in the systolic phase) and counter-pulse mode (increased RS in the diastolic phase), as well as shifting the change in RS from 250 to 500rpm, and 750rpm in both modes on pulsatility and LV load. Pulsatility was assessed using pulse pressure and mean dP/dt max of aortic pressure. LV load was assessed using stroke work and left ventricle end-diastolic volume determined from LV pressure-volume loops. In the co-pulse mode, pulsatility values increased as the change in RS increased. By contrast, in the counter-pulse mode, these values decreased as the change in RS increased. LV load increased significantly in the co-pulse mode compared with the counter-pulse mode, but there were no significant differences among the three levels of RS increase in either mode. Increasing RS to varying degrees with our newly developed system could contribute to pulsatility. However, it appeared to have little effect on LV load in normal hearts.

The Real Sector in February 2016

In early 2016, Russia’s domestic market was exposed to the long-continued influence of a simultaneous contraction of the consumer and investment markets. In January and February, the retail trade turnover index amounted to 93.4%, the volume index of commercial services rendered to the population – to 98.3%, and the construction work volume index – to 98.3% relative to the same period of the previous year. Early 2016 saw a notable deterioration of social parameters. In February 2016, the real disposable income and real wages of the population amounted to 93.1% and 97.4% relative to February 2015. The situation in the labor market remained tense – in February, the number of officially registered unemployed increased by 5.2% on January 2016.

Thermal volumetric effects under axes cycling using an invar R-test device and reference length

Thermal errors of machine tools are in part caused by the variation of ambient temperature as well as the heat internally generated by the machine. These deformations are a major source of quasi-static machining errors and are thought to be related to temperatures and temperature gradients within the machine structure. This article presents a study of the thermal volumetric behavior of a five-axis machine tool. The study uses direct volumetric error measurements within the machine work volume for specific combinations of five-axis commands. Thermally induced volumetric distortion errors are studied in relation to a specifically designed machine activity sequence during which the power at each of the five-axis motors and the spindle are measured. The experimental measurement setup consisting of a thermally stable volumetric error sensor and a reference scale bar is presented. The study allows quantifying the effect of every axis’ activity on the Cartesian components of the volumetric distortion. Rotary axes are found to be the major contributors to the tested machine's thermal errors. Thermal coupling is observed whereby the activity of a rotary axis strongly affects a neighboring linear axis.

Mitral Valve Regurgitation with a Rotary Left Ventricular Assist Device: The Haemodynamic Effect of Inlet Cannulation Site and Speed Modulation.

Mitral valve regurgitation (MVR) is common in patients receiving left ventricular assist device (LVAD) support, however the haemodynamic effect of MVR is not entirely clear. This study evaluated the haemodynamic effect of MVR with LVAD support and the influence of inflow cannulation site and LVAD speed modulation. Left atrial (LAC) and ventricular (LVC) cannulation was evaluated in a mock circulation loop with no, mild, moderate and severe MVR with constant speed and speed modulation (±600 RPM) modes. The use of an LVAD relieved pulmonary congestion during severe MVR, by reducing left atrial pressure from 20.5 to 10.8 (LAC) and 11.5 (LVC) mmHg. However, LAC resulted in decreased left ventricular stroke work (-0.08J), ejection fraction (-7.9%) and higher MVR volume (+12.7mL) and pump speed (+100 RPM) compared to LVC. This suggests that LVC, in addition to reducing MVR severity, also improves ventricular washout over LAC. LVAD speed modulation in synchrony with ventricular systole reduced MVR volume and increased ejection fraction with LAC and LVC, thus demonstrating the potential benefits of this mode, despite a reduction in cardiac output.

Appraisers and Valuation Bias: An Empirical Analysis

Using appraisals from a lender across the 2005–2006 period, we find that the association between appraisers’ valuation inflation patterns and work volume varies across states. Moreover, we find a considerable occupational exit for appraisers, and provide evidence that appraisers, as applicants, did not receive better loan pricing compared with the population of applicants. Overall, this article offers novel insights concerning the political economy of financial regulation through the lens of a specific profession.

Le syndrome d’épuisement professionnel et les facteurs de risques psychosociaux spécifiques au métier des personnels navigants commerciaux libanais, en comparaison avec un groupe témoin

ObjectiveThe aim of our study was to investigate the influence of demographic factors (gender and age), work related factors (the position and years of practice) and psychosocial risk factors (cognitive demands, demands to hide emotions, work–family conflict, offensive behaviors…) on the development of burnout among flight attendants, and the nature of psychosocial factors to which they are exposed. MethodsThe sample was divided into two groups: 67 flight attendants and 67 persons in various jobs. Our sampling units were informed and consented to fill in two questionnaires: the Copenhagen burnout inventory (CBI) and the Copenhagen Psychosocial Questionnaire (COPSOQ II). ResultsThe burnout syndrome affected both groups equally. It affected equally the women as well as men, whatever their age categories and their years of experience. The flight attendants occupying an intermediate position in the hierarchy had the highest score on the burnout syndrome. The psychosocial factors significantly found in flight attendants compared to the control group were: demands for hiding emotions, quantitative demands, emotional demands, temporal demands, lack of influence at work, of rewards, of possibility for development and variation of work, poor quality of leadership, exposure to sexual harassment, lack of social support from supervisors, colleagues, social community at work and work–family conflict. Four of them correlated positively with the development of burnout: quantitative demands, temporal demands, emotional demands and work–family conflict. Their expected work volume is very high (quantitative demands). They have to perform their tasks quickly in a limited time without forgetting the technical constraints (temporal demands). They have to work with an average of three hundred passengers besides colleagues and subordinates, which requires diligent control of the emotions promoted by the airline code of conduct based on repression of emotions (emotional demands). These demands affect the workers once they find themselves in their family environment and can have a negative effect on their private life (work–family conflict). However, the predictability seems to allow them to be aware of decisions and changes and protect them against burnout. ConclusionThe profession of flight attendants appears to be characterized by some psychosocial risk factors, some of which are positively correlated with burnout. Improved working conditions can prevent these risks and protect these employees from burnout.

A neural network-based methodology for inverse kinematics of a multi-finger robotic hand for gripping

Robotic grasping and manipulation require controlling the gripper movement through different points in its work volume, necessitating inverse kinematics computations to determine joint angles. In the present work, a novel methodology, based on a radial basis function neural network, has been proposed for the inverse kinematics solution and a genetic algorithm-based approach for optimising the neural network parameters. Instead of taking the entire work volume of the hand for neural network training, a subspace of points is created in close vicinity of the given destination point. The joint variables corresponding to a destination point are obtained using a random walk algorithm that uses the forward kinematics model of the hand. Then, the subspace of points and the corresponding joint variables obtained above are used to train the neural network. This approach can provide an approximate yet fairly quick and effective solution to the inverse kinematics problem of multi-finger robot hands.

Robotic Disease Detection in Greenhouses: Combined Detection of Powdery Mildew and Tomato Spotted Wilt Virus

Robotic systems for disease detection in greenhouses are expected to improve disease control, increase yield, and reduce pesticide application. We present a robotic detection system for combined detection of two major threats of greenhouse bell peppers: Powdery mildew (PM) and Tomato spotted wilt virus (TSWV). The system is based on a manipulator, which facilitates reaching multiple detection poses. Several detection algorithms are developed based on principal component analysis (PCA) and the coefficient of variation (CV). Tests ascertain the system can successfully detect the plant and reach the detection pose required for PM (along the side of the plant), yet it has difficulties in reaching the TSWV detection pose (above the plant). Increasing manipulator work–volume is expected to solve this issue. For TSWV, PCA-based classification with leaf vein removal, achieved the highest classification accuracy (90%) while the accuracy of the CV methods was also high (85% and 87%). For PM, PCA-based pixel-level classification was high (95.2%) while leaf condition classification accuracy was low (64.3%) since it was determined based on the upper side of the leaf while disease symptoms start on its lower side. Exposure of the lower side of the leaf during detection is expected to improve PM condition detection.

Safety and Health Practices in the Food Industry and Ergonomic Interventions

Occupational safety and health (OSH) problems of the food industry have not been generally perceived as a serious issue in the same way as other industries such as healthcare, transportation, mining, and construction sectors. Statistics from various countries show that OSH issues from the food sector have one of the worst records in the manufacturing industries [1,2]. There are also evidences that some OSH aspects in the food industry are getting worse. Despite global economic declines in the recent years, the food and drink businesses have continued to expand in response to the growing worldwide demands for processed foods and drinks [1,2]. In this context of expansion and intensified competition, the food industry has experienced rationalization, restructuring, and a high level of mechanization, in both the industrialized and developing countries [1,2]. As a result, the overall worldwide employment levels in the sector have continued to expand, particularly in the highly capital-intensive drink industry has suffered. Moreover, mechanization has often had the effect of increasing the work volumes and the resulting stress levels of workers, as well as increasing the number of monotonous and repetitive tasks, with a consequent rise in the incidence of musculoskeletal disorders (MSDs). Increased automation has also been accompanied by higher noise levels, which has led to more workers suffering from hearing impediments [3]. Other common OSH problems in the food industry arise out of handling sharp cutting tools, exposing dusts in the air, contacting with infected animals, and increasing use of hazardous chemicals [3].

Prediction of Muscle Fatigue during Minimally Invasive Surgery Using Recurrence Quantification Analysis

Due to its inherent complexity such as limited work volume and degree of freedom, minimally invasive surgery (MIS) is ergonomically challenging to surgeons compared to traditional open surgery. Specifically, MIS can expose performing surgeons to excessive ergonomic risks including muscle fatigue that may lead to critical errors in surgical procedures. Therefore, detecting the vulnerable muscles and time-to-fatigue during MIS is of great importance in order to prevent these errors. The main goal of this study is to propose and test a novel measure that can be efficiently used to detect muscle fatigue. In this study, surface electromyography was used to record muscle activations of five subjects while they performed fifteen various laparoscopic operations. The muscle activation data was then reconstructed using recurrence quantification analysis (RQA) to detect possible signs of muscle fatigue on eight muscle groups (bicep, triceps, deltoid, and trapezius). The results showed that RQA detects the fatigue sign on bilateral trapezius at 47.5 minutes (average) and bilateral deltoid at 57.5 minutes after the start of operations. No sign of fatigue was detected for bicep and triceps muscles of any subject. According to the results, the proposed novel measure can be efficiently used to detect muscle fatigue and eventually improve the quality of MIS procedures with reducing errors that may result from overlooked muscle fatigue.

Recurrence quantification analysis for surgical motions in minimally invasive surgery

Minimally invasive surgical technique (MIS) is difficult to master due to its inherent complexity imposed by reduced work volume and limited flexibility in motions. In traditional MIS training, faculty surgeons evaluate junior surgeon's performance using subjective and resource-intensive methods lacking quantitative rigour. Although recent technological advancement in surgical education has enabled more objective and automated evaluation of surgical skill, most of measures are still task-specific and thus can be hardly generalised across different operations and platforms. Therefore, this research studies a novel framework for generalised performance measure based on the analysis of non-linear dynamics in surgical motions. Specifically, surgical motions are recorded using motion sensors attached on instruments during surgical exercises. Then, intensity of recurrences in the motion data is calculated and disorder index is computed using the intensity of recurrences. The test results have shown that disorder index values can be used to quantify surgical skill levels.

Heeding the Call: Advances in Social Work Intervention Research

Heeding the Call: Advances in Social Work Intervention Research

Selecting Optimal Project Delivery System for Infrastructural Projects Using Analytic Hierarchy Process

Enormous financial requirements, high technological and scientific level, high work volume are the main differentiations between infrastructural andnormal projects. Given these specifications, selection of suitable project delivery system (PDS) for construction of infrastructural projects is of paramount importance, and making mistake and miscalculation in this field will incur irreparable loss to the development projects. Therefore, adoption of suitable policy in decision-making process with regard to the construction operation of project is of paramount significance, so that development of systems and logistics tools for the decision-making process can help project commissioners to improve current activities in the best form possible. The paper presents a decision-making model to select the optimal PDS for infrastructural construction projects based on identification and comparison of various contracting systems. The viewpoints of 62 expert engineers, contractors, consultants about the advantage and drawbacks of five more common PDSs have been collected via questionnaires and interviews. At the end, a comprehensive methodology has been presented to fine the optimal PDS for each Infrastructural project using Analytic Hierarchy Process (AHP).

A Novel Continuum Robot Using Twin-Pivot Compliant Joints: Design, Modeling, and Validation

A twisting problem is identified from the central located flexible backbone continuum robot. Regarding this problem, a design solution is required to mechanically minimize this twisting angle along the backbone. Further, the error caused by the kinematic assumption of previous works is identified as well, which requires a kinematic solution to minimize. The scope of this paper is to introduce, describe and teste a novel design of continuum robot which has a twin-pivot compliant joint construction that minimizes the twisting around its axis. A kinematics model is introduced which can be applied to a wide range of twin-pivot construction with two pairs of cables per section design. And according to this model, the approach for minimising the kinematic error is developed. Furthermore, based on the geometry and material property of compliant joint, the work volumes for single/three-section continuum robot are presented, respectively. The kinematic analysis has been verified by a three-section prototype of continuum robot and adequate accuracy and repeatability tests carried out. And in the test, the system generates relatively small twisting angles when a range of end loads is applied at the end of the arm. Utilising the concept presented in this paper, it is possible to develop a continuum robot which can minimize the twisting angle and be accurately controlled. In this paper, a novel design of continuum robot which has a twin-pivot compliant joint construction that minimizes the twisting around its axis is introduced, described and tested. A kinematics model is introduced which can be applied to a wide range of twin-pivot construction with two pairs of cables per section design. Furthermore, based on the geometry and material property of compliant joint, the work volumes for single/three-section continuum robot are presented, respectively. Finally, the kinematic analysis has been verified by a three-section prototype of continuum and adequate accuracy and repeatability tests carried out.

European Journal of Work and Organizational Psychology Volume 24, 2015, List of Reviewers

European Journal of Work and Organizational Psychology Volume 24, 2015, List of Reviewers