Analysis of mixed motion in deterministic ratchets via experiment and particle simulation

Deterministic lateral displacement (DLD) ratchets are microfluidic devices, which are used for size-based sorting of cells or DNA. Based on their size, particles are showing different kinds of motion, leading to their fractionation. In earlier studies, so-called zigzag and displacement motions are observed, and in recent study by our group (Kulrattanarak et al., Meas Sci Technol, 2010a; J Colloid Interface Sci, 2010b), we have shown that also mixed motion occurs, which is an irregular alternation of zigzag and displacement motion. We have shown that the mixed motion is due to asymmetry of the flow lane distribution, induced by the symmetry breaking of the oblique primitive lattice cell (Kulrattanarak et al. 2010b). In this study, we investigate mixed motion in depth by numerical and experimental analysis. Via 3D simulations, we have computed explicit particle trajectories in DLD, and are able to show that there are two critical length scales determining the type of motion. The first length scale d f,1 is the first flow lane width, which determines the transition between zigzag motion and mixed motion. The other length scale, d f,c , determines the transition between mixed motion and displacement motion. Based on our experimental and numerical results we have been able to correlate the migration angle of particles showing mixed motion to the particle size, relative to the two critical length scales d f,1 and d f,

Management Accounting Change and ERP, an Assessment of Research

Extant accounting literature shows that there is increasing research interest into effects of ERP systems on management accounting and control practices (c.f. Granlund, Mouritsen, 2003). This paper provides a review of the literature and identifies knowledge gaps and shows opportunities for research. The review reveals that there are two main streams of research. The first uses a structural approach, while the second uses a process approach. The structural stream adopts a functional approach to technology and is deterministic in nature. It implies the assumption that ERP is the driver of organizational performance improvement. The process approach stream on the other hand seeks to explain how processes of change unfold and how outcomes develop over time (see for example Granlund and Mouritsen, 2001, Granlund and Malmi, 2000, Scapens and Jazayeri, 2003, Caglio, 2003, Quattrone and Hopper, 2004). The focus in this stream is on several different issues, such as hybridization of the accountants' work due to the adoption of ERP and the impacts of ERP on introducing innovative accounting practices. The review of extant literature reveals that there is no cumulative body of research. In this paper several causes for this lack of accumulation are identified. Furthermore, there proves to be very limited coherence among the different studies. Finally, our review shows that although there is some attention for effects of ERP on Management Control, research on this particular subject is still very much lagging behind. We extend our literature review by going through literature from the Information Systems field. It proves that there are some similarities between the two different fields. Based on the findings of our literature review the following recommendations for further research are given: (1) Focus on studying the Management Control aspects of ERP, using a process approach, (2) Build on the results of earlier results of research in Accounting, and (3) Build on the results of earlier research in the IS field.Management Accounting Change, ERP systems, management control theory, Information Systems

Cardiovascular effects of overt and subclinical hyperthyroidism:focus on differentiated thyroid cancer

Thyroid hormone stimulates cardiac inotropy and chronotropy via direct genomic and non-genomic mechanisms. Hyperthyroidism magnifies these effects, resulting in an increase in heart rate, ejection fraction and blood volume. Hyperthyroidism also affects thrombogenesis and this may be linked to a probable tendency towards thrombosis in patients with hyperthyroidism. Patients with hyperthyroidism are therefore at higher risk for atrial fibrillation, heart failure and cardiovascular mortality. Similarly, TSH suppressive therapy for differentiated thyroid cancer is associated with increased cardiovascular risk. In this review, we present the latest insights on the cardiac effects of thyroid suppression therapy for the treatment of thyroid cancer. Finally, we will show new clinical data on how to implement this knowledge into the clinical practice of preventive medicine

Management Accounting Change and ERP, an Assessment of Research

Extant accounting literature shows that there is increasing research interest into effects of ERP systems on management accounting and control practices (c.f. Granlund, Mouritsen, 2003). This paper provides a review of the literature and identifies knowledge gaps and shows opportunities for research. The review reveals that there are two main streams of research. The first uses a structural approach, while the second uses a process approach. The structural stream adopts a functional approach to technology and is deterministic in nature. It implies the assumption that ERP is the driver of organizational performance improvement. The process approach stream on the other hand seeks to explain how processes of change unfold and how outcomes develop over time (see for example Granlund and Mouritsen, 2001, Granlund and Malmi, 2000, Scapens and Jazayeri, 2003, Caglio, 2003, Quattrone and Hopper, 2004). The focus in this stream is on several different issues, such as hybridization of the accountants' work due to the adoption of ERP and the impacts of ERP on introducing innovative accounting practices. The review of extant literature reveals that there is no cumulative body of research. In this paper several causes for this lack of accumulation are identified. Furthermore, there proves to be very limited coherence among the different studies. Finally, our review shows that although there is some attention for effects of ERP on Management Control, research on this particular subject is still very much lagging behind. We extend our literature review by going through literature from the Information Systems field. It proves that there are some similarities between the two different fields. Based on the findings of our literature review the following recommendations for further research are given: (1) Focus on studying the Management Control aspects of ERP, using a process approach, (2) Build on the results of earlier results of research in Accounting, and (3) Build on the results of earlier research in the IS field

Management Accounting Change and ERP, an Assessment of Research

Extant accounting literature shows that there is increasing research interest into effects of ERP systems on management accounting and control practices (c.f. Granlund, Mouritsen, 2003). This paper provides a review of the literature and identifies knowledge gaps and shows opportunities for research. The review reveals that there are two main streams of research. The first uses a structural approach, while the second uses a process approach. The structural stream adopts a functional approach to technology and is deterministic in nature. It implies the assumption that ERP is the driver of organizational performance improvement. The process approach stream on the other hand seeks to explain how processes of change unfold and how outcomes develop over time (see for example Granlund and Mouritsen, 2001, Granlund and Malmi, 2000, Scapens and Jazayeri, 2003, Caglio, 2003, Quattrone and Hopper, 2004). The focus in this stream is on several different issues, such as hybridization of the accountants' work due to the adoption of ERP and the impacts of ERP on introducing innovative accounting practices. The review of extant literature reveals that there is no cumulative body of research. In this paper several causes for this lack of accumulation are identified. Furthermore, there proves to be very limited coherence among the different studies. Finally, our review shows that although there is some attention for effects of ERP on Management Control, research on this particular subject is still very much lagging behind. We extend our literature review by going through literature from the Information Systems field. It proves that there are some similarities between the two different fields. Based on the findings of our literature review the following recommendations for further research are given: (1) Focus on studying the Management Control aspects of ERP, using a process approach, (2) Build on the results of earlier results of research in Accounting, and (3) Build on the results of earlier research in the IS field

The Value of Pre-Ablative I-131 Scan for Clinical Management in Patients With Differentiated Thyroid Carcinoma

BACKGROUND: A diagnostic I-131 (Dx) scan is used to detect a thyroid remnant or metastases before treatment of differentiated thyroid cancer (DTC) with I-131. The aim of this study is to specify in which patients with DTC a Dx scan could have an additional value, by studying the effect of the Dx scan on clinical management. METHODS: Patients with DTC, treated with I-131 after thyroidectomy were included in this retrospective cohort study. Twenty-four hours after administration of 37 MBq I-131 a whole body Dx scan and an uptake measurement at the original thyroid bed were performed. Outcomes of the Dx scan and the subsequent changes in clinical management, defined as additional surgery or adjustment of I-131 activity, were reported. Risk factors for a change in clinical management were identified with a binary logistic regression. RESULTS: In 11 (4.2%) patients clinical management was changed, including additional surgery (n=5), lowering I-131 activity (n=5) or both (n=1). Risk factors for a change in clinical management were previous neck surgery (OR 5.9, 95% CI: 1.4-24.5), surgery in a non-tertiary center (OR 13.4, 95% CI: 2.8 – 63.8), TSH <53.4 mU/L (OR 19.64, 95% CI: 4.94-78.13), thyroglobulin ≥50.0 ng/L (OR 7.4, 95% CI: 1.6-34.9) and free T4 ≥4.75 pmol/L (OR 156.8, 95% CI: 128.4-864.2) CONCLUSION: The Dx scan can potentially change clinical management before treatment with I-131, but the yield is low. A Dx-scan should only be considered for patients with a high pre-scan risk of a change in management, based on patient history and prior center-based surgical outcomes

Generation of representative primary virus isolates from blood plasma after isolation of HIV-1 with CD44 MicroBeads

Infection of cell cultures with cell-free virus isolated from HIV-infected patients is notoriously difficult and results in a loss of viral variation. Here, we describe viral sequences from PBMC, U87.CD4.CCR5 and U87.CD4.CXCR4 cell cultures and compare them to those from blood plasma from 12 patients from whom virus particles were isolated using CD44 MicroBeads. In both PBMC and U87.CD4.CCR5 cultures, 66% of the plasma viral strains were retrieved after culturing. In addition, coreceptor use was predicted based on the env-V3 sequence and tested in U87.CD4 cells expressing either CCR5 or CXCR4. Recovery was lower for the CXCR4-using viruses. Only 50% of the virus clusters predicted to use CXCR4 could be retrieved from cell cultures, while 71% of CCR5-using strains were found in U87.CCR5 cultures. Therefore, isolation of primary viruses with CD44 MicroBeads results in a good representation in cell culture of the in vivo divergence

Insulin treatment guided by subcutaneous continuous glucose monitoring compared to frequent point-of-care measurement in critically ill patients: a randomized controlled trial

Glucose measurement in intensive care medicine is performed intermittently with the risk of undetected hypoglycemia. The workload for the ICU nursing staff is substantial. Subcutaneous continuous glucose monitoring (CGM) systems are available and may be able to solve some of these issues in critically ill patients. In a randomized controlled design in a mixed ICU in a teaching hospital we compared the use of subcutaneous CGM with frequent point of care (POC) to guide insulin treatment. Adult critically ill patients with an expected stay of more than 24 hours and in need of insulin therapy were included. All patients received subcutaneous CGM. CGM data were blinded in the control group, whereas in the intervention group these data were used to feed a computerized glucose regulation algorithm. The same algorithm was used in the control group fed by intermittent POC glucose measurements. Safety was assessed with the incidence of severe hypoglycemia ( <2.2 mmol/L), efficacy with the percentage time in target range (5.0 to 9.0 mmol/L). In addition, we assessed nursing workload and costs. In this study, 87 patients were randomized to the intervention and 90 to the control group. CGM device failure resulted in 78 and 78 patients for analysis. The incidence of severe glycemia and percentage of time within target range was similar in both groups. A significant reduction in daily nursing workload for glucose control was found in the intervention group (17 versus 36 minutes; P <0.001). Mean daily costs per patient were significantly reduced with EUR 12 (95% CI -32 to -18, P = 0.02) in the intervention group. Subcutaneous CGM to guide insulin treatment in critically ill patients is as safe and effective as intermittent point-of-care measurements and reduces nursing workload and daily costs. A new algorithm designed for frequent measurements may lead to improved performance and should precede clinical implementation. Clinicaltrials.gov, NCT01526044. Registered 1 February 201

Using a satellite swarm for building a space-based radio telescope for low frequencies

In radio astronomy, as in astronomy in general, a wide range of frequencies is observed as each spectral band o_ers a unique window to study astrophysical phenomena. In the recent years, new observatories have been designed and built at the extreme limits of the radio spectrum. For the low frequencies several Earth-based radio telescopes are constructed at this moment. In the Netherlands, the Low Frequency Array (LOFAR) is being constructed at this moment and will be operational later this year. LOFAR observes the sky between 30 and 240 MHz. Observing at even lower frequencies is very interesting, but, due to the inuence of the Earth's ionosphere this is not possible from Earth. Thus, the only option to observe low frequencies is a telescope in spac