Cell proliferation, cell shape, and microtubule and cellulose microfibril organization of tobacco BY-2 cells are not altered by exposure to near weightlessness in space

The microtubule cytoskeleton and the cell wall both play key roles in plant cell growth and division, determining the plant’s final stature. At near weightlessness, tubulin polymerizes into microtubules in vitro, but these microtubules do not self-organize in the ordered patterns observed at 1g. Likewise, at near weightlessness cortical microtubules in protoplasts have difficulty organizing into parallel arrays, which are required for proper plant cell elongation. However, intact plants do grow in space and therefore should have a normally functioning microtubule cytoskeleton. Since the main difference between protoplasts and plant cells in a tissue is the presence of a cell wall, we studied single, but walled, tobacco BY-2 suspension-cultured cells during an 8-day space-flight experiment on board of the Soyuz capsule and the International Space Station during the 12S mission (March–April 2006). We show that the cortical microtubule density, ordering and orientation in isolated walled plant cells are unaffected by near weightlessness, as are the orientation of the cellulose microfibrils, cell proliferation, and cell shape. Likely, tissue organization is not essential for the organization of these structures in space. When combined with the fact that many recovering protoplasts have an aberrant cortical microtubule cytoskeleton, the results suggest a role for the cell wall, or its production machinery, in structuring the microtubule cytoskeleto

Precision and sample size requirements for regression-based norming methods for change scores

To interpret a person’s change score, one typically transforms the change score into, for example, a percentile, so that one knows a person’s location in a distribution of change scores. Transformed scores are referred to as norms and the construction of norms is referred to as norming. Two often-used norming methods for change scores are the regression-based change approach and the T Scores for Change method. In this article, we discuss the similarities and differences between these norming methods, and use a simulation study to systematically examine the precision of the two methods and to establish the minimum sample size requirements for satisfactory precision

Steps toward preregistration of research on research integrity

Abstract Background A proposal to encourage the preregistration of research on research integrity was developed and adopted as the Amsterdam Agenda at the 5th World Conference on Research Integrity (Amsterdam, 2017). This paper reports on the degree to which abstracts of the 6th World Conference in Research Integrity (Hong Kong, 2019) reported on preregistered research. Methods Conference registration data on participants presenting a paper or a poster at 6th WCRI were made available to the research team. Because the data set was too small for inferential statistics this report is limited to a basic description of results and some recommendations that should be considered when taking further steps to improve preregistration. Results 19% of the 308 presenters preregistered their research. Of the 56 usable cases, less than half provided information on the six key elements of the Amsterdam Agenda. Others provided information that invalidated their data, such as an uninformative URL. There was no discernable difference between qualitative and quantitative research. Conclusions Some presenters at the WCRI have preregistered their research on research integrity, but further steps are needed to increase frequency and completeness of preregistration. One approach to increase preregistration would be to make it a requirement for research presented at the World Conferences on Research Integrity.http://deepblue.lib.umich.edu/bitstream/2027.42/174042/1/41073_2021_Article_108.pd

A risk score for identifying methicillin-resistant Staphylococcus aureus in patients presenting to the hospital with pneumonia.

Background Methicillin-resistant Staphylococcus aureus (MRSA) represents an important pathogen in healthcare-associated pneumonia (HCAP). The concept of HCAP, though, may not perform well as a screening test for MRSA and can lead to overuse of antibiotics. We developed a risk score to identify patients presenting to the hospital with pneumonia unlikely to have MRSA. Methods We identified patients admitted with pneumonia (Apr 2005 – Mar 2009) at 62 hospitals in the US. We only included patients with lab evidence of bacterial infection (e.g., positive respiratory secretions, blood, or pleural cultures or urinary antigen testing). We determined variables independently associated with the presence of MRSA based on logistic regression (two-thirds of cohort) and developed a risk prediction model based on these factors. We validated the model in the remaining population. Results The cohort included 5975 patients and MRSA was identified in 14%. The final risk score consisted of eight variables and a potential total score of 10. Points were assigned as follows: two for recent hospitalization or ICU admission; one each for age \u3c 30 or \u3e 79 years, prior IV antibiotic exposure, dementia, cerebrovascular disease, female with diabetes, or recent exposure to a nursing home/long term acute care facility/skilled nursing facility. This study shows how the prevalence of MRSA rose with increasing score after stratifying the scores into Low (0 to 1 points), Medium (2 to 5 points) and High (6 or more points) risk. When the score was 0 or 1, the prevalence of MRSA was \u3c 10% while the prevalence of MRSA climbed to \u3e 30% when the score was 6 or greater. Conclusions MRSA represents a cause of pneumonia presenting to the hospital. This simple risk score identifies patients at low risk for MRSA and in whom anti-MRSA therapy might be withheld

The certification of anti-myeloperoxidase immunoglobulin G in human serum ERM® - DA476/IFCC

This report describes the production and certification of ERM-DA476/IFCC, a new serum protein reference material intended for the standardisation of measurements of anti-myeloperoxidase immunoglobulin G (anti-MPO IgG) antibodies. The material was produced according to ISO Guide 34:2009. The raw material used to prepare ERM-DA476/IFCC was a plasmapheresis material containing a high concentration of anti-MPO IgG. After a thorough commutability study lyophilised serum was selected as the format for the candidate reference material. Serum processing was performed based on the procedure used for the reference material ERM-DA470k/IFCC. The plasma was converted into serum which was then delipidated. After the addition of preservatives the processed serum was diluted with plasmapheresis solution containing albumin, prior to the transfer of 1 mL aliquots to glass vials. The serum was then lyophilised and the vials closed with rubber stoppers and screw caps under nitrogen atmosphere prior to storage at -70 °C. The between unit-homogeneity was quantified and stability during dispatch and storage were assessed in accordance with ISO Guide 35:2006. The material was characterised by an inter-laboratory comparison exercise performed by laboratories of demonstrated competence and with adherence to ISO/IEC 17025 , using a purified anti-MPO IgG preparation as calibrant. This was achieved using a value transfer protocol previously used in the characterisation of ERM-DA470k/IFCC. Technically invalid results were removed. However no other outliers were eliminated on statistical grounds only. Uncertainties of the certified values were calculated in accordance to the Guide to the Expression of Uncertainty in Measurement (GUM) and include uncertainties relating to possible lack of homogeneity, instability and characterisation. The material is intended for the calibration of methods and quality control. As any reference material, it can also be used for control charts or validation studies. The CRM is available in glass vials containing the lyophilised residue of 1 g serum. The minimum amount of reconstituted sample to be used is 10 μL. The CRM was accepted as European Reference Material (ERM®) after peer evaluation by the partners of the European Reference Materials consortium

A more active lifestyle in persons with a recent spinal cord injury benefits physical fitness and health

Study design:A prospective cohort study. Objectives:To study the longitudinal relationship between objectively measured everyday physical activity level, and physical fitness and lipid profile in persons with a recent spinal cord injury (SCI).Setting:A rehabilitation centre in the Netherlands and the participant's home environment. Methods:Data of 30 persons with a recent SCI were collected at the start of active rehabilitation, 3 months later, at discharge from inpatient rehabilitation, and 1 year after discharge. Physical activity level (duration of dynamic activities as % of 24 h) was measured with an accelerometry-based activity monitor. Regarding physical fitness, peak oxygen uptake (VO2peak) and peak power output (POpeak) were determined with a maximal wheelchair exercise test, and upper extremity muscle strength was measured with a handheld dynamometer. Fasting blood samples were taken to determine the lipid profile. Results:An increase in physical activity level was significantly related to an increase in VO2peak and POpeak, and an increase in physical activity level favourably affected the lipid profile. A nonsignificant relation was found with muscle strength. Conclusion:Everyday physical activity seems to have an important role in the fitness and health of persons with a recent SCI. An increase in physical activity level was associated with an increase in physical fitness and with a lower risk of cardiovascular disease.Spinal Cord advance online publication, 6 December 2011; doi:10.1038/sc.2011.152

Incentive Compatible Reimbursement Schemes for Physicians

We consider physicians with fixed capacity levels. If a physician’s capacity exceeds demand, she may have an incentive to overtreat, i.e., she may provide unnecessary treatments to use up idle capacity. By contrast, with excess demand she may undertreat, i.e., she may not provide necessary treatments since other activities are financially more attractive. We first show that simple fee-for-service reimbursement schemes do not provide proper incentives. If insurers use, however, fee-for-service schemes with quantity restrictions, they solve the fraudulent physician problem

Fish Allergy:Fishing for Novel Diagnostic and Therapeutic Options

Fish allergy is one of the most common food allergies. The currently recommended treatment commonly consists of avoiding all fish species. Recent literature suggests that these recommendations are overprotective for the majority of fish-allergic patients. This review summarizes recent findings and provides practical information regarding management of fish allergy in the individual patient. After precise history taking supported by additional specific IgE measurements and/or skin prick tests, fish-allergic patients can generally be categorized into the following clinical clusters: (A) poly-sensitized patients reacting to all fish species due to their sensitization to the panallergen β-parvalbumin, (B) mono-sensitized patients with selective reactions to individual fish species only, and (C) oligo-sensitized patients reacting to several specific fish. A number of allergens including parvalbumin, enolase, and aldolase can be involved. Depending on the specific cluster the patient belongs to, oral food challenges for one or more fish species can be performed with the aim to provide safe alternatives for consumption. This way, several alternative fish species can be identified for mono- and oligo-sensitized patients that can safely be consumed. Notably, even poly-sensitized patients generally tolerate fish species low in β-parvalbumin such as tuna and mackerel, particularly when processed. Taken together, allergological evaluation of patients with a documented fish allergy should be strongly considered, as it will allow the majority of patients to safely reintroduce one or more fish species