Using Weibull Distribution Analysis to Evaluate ALARA Performance

Abstract -As Low as Reasonably Achievable (ALARA) is the underlying principle for protecting nuclear workers from potential health outcomes related to occupational radiation exposure. Radiation protection performance is currently evaluated by measures such as collective dose and average measurable dose, which do not indicate ALARA performance. The purpose of this work is to show how statistical modeling of individual doses using the Weibull distribution can provide objective supplemental performance indicators for comparing ALARA implementation among sites and for insights into ALARA practices within a site. Maximum likelihood methods were employed to estimate the Weibull shape and scale parameters used for performance indicators. The shape parameter reflects the effectiveness of maximizing the number of workers receiving lower doses and is represented as the slope of the fitted line on a Weibull probability plot. Additional performance indicators derived from the model parameters include the 99 th percentile and the exceedance fraction. When grouping sites by collective total effective dose equivalent (TEDE) and ranking by 99 th percentile with confidence intervals, differences in performance among sites can be readily identified. Applying this methodology will enable more efficient and complete evaluation of the effectiveness of ALARA implementation

The Applied Meteorology Unit: Nineteen Years Successfully Transitioning Research Into Operations for America's Space Program

The Applied Meteorology Unit (AMU) provides technology development and transition services to improve operational weather support to America's space program . The AMU was founded in 1991 and operates under a triagency Memorandum of Understanding (MOU) between the National Aeronautics and Space Administration (NASA), the United States Air Force (USAF) and the National Weather Service (NWS) (Ernst and Merceret, 1995). It is colocated with the 45th Weather Squadron (45WS) at Cape Canaveral Air Force Station (CCAFS) and funded by the Space Shuttle Program . Its primary customers are the 45WS, the Spaceflight Meteorology Group (SMG) operated for NASA by the NWS at the Johnson Space Center (JSC) in Houston, TX, and the NWS forecast office in Melbourne, FL (MLB). The gap between research and operations is well known. All too frequently, the process of transitioning research to operations fails for various reasons. The mission of the AMU is in essence to bridge this gap for America's space program

Using Weibull Distribution Analysis to Evaluate ALARA Performance

As Low as Reasonably Achievable (ALARA) is the underlying principle for protecting nuclear workers from potential health outcomes related to occupational radiation exposure. Radiation protection performance is currently evaluated by measures such as collective dose and average measurable dose, which do not indicate ALARA performance. The purpose of this work is to show how statistical modeling of individual doses using the Weibull distribution can provide objective supplemental performance indicators for comparing ALARA implementation among sites and for insights into ALARA practices within a site. Maximum likelihood methods were employed to estimate the Weibull shape and scale parameters used for performance indicators. The shape parameter reflects the effectiveness of maximizing the number of workers receiving lower doses and is represented as the slope of the fitted line on a Weibull probability plot. Additional performance indicators derived from the model parameters include the 99th percentile and the exceedance fraction. When grouping sites by collective total effective dose equivalent (TEDE) and ranking by 99th percentile with confidence intervals, differences in performance among sites can be readily identified. Applying this methodology will enable more efficient and complete evaluation of the effectiveness of ALARA implementation

Erythropoietin (EPO) increases myelin gene expression in CG4 oligodendrocyte cells through the classical EPO receptor

Erythropoietin (EPO) has protective effects in neurodegenerative and neuroinflammatory diseases, including in animal models of multiple sclerosis, where EPO decreases disease severity. EPO also promotes neurogenesis and is protective in models of toxic demyelination. In this study, we asked whether EPO could promote neurorepair by also inducing remyelination. In addition, we investigated whether the effect of EPO could be mediated by the classical erythropoietic EPO receptor (EPOR), since it is still questioned if EPOR is functional in non-hematopoietic cells. Using CG4 cells, a line of rat oligodendrocyte precursor cells, we found that EPO increases the expression of myelin genes (myelin oligodendrocyte glycoprotein (MOG) and myelin basic protein (MBP)). EPO had no effect in wild-type CG4 cells, which do not express EPOR, whereas it increased MOG and MBP expression in cells engineered to overexpress EPOR (CG4-EPOR). This was reflected in a marked increase in MOG protein levels, as detected by western blot. In these cells, EPO induced by 10-fold the early growth response gene 2 (Egr2), which is required for peripheral myelination. However, Egr2 silencing with a siRNA did not reverse the effect of EPO, indicating that EPO acts through other pathways. In conclusion, EPO induces the expression of myelin genes in oligodendrocytes and this effect requires the presence of EPOR. This study demonstrates that EPOR can mediate neuroreparative effects

Functional brush poly(2-ethyl-2-oxazine)s : synthesis by CROP and RAFT, thermoresponsiveness and grafting onto iron oxide nanoparticles

Brush polymers are highly functional polymeric materials combining the properties of different polymer classes and have found numerous applications, for example, in nanomedicine. Here, the synthesis of functional phosphonate‐ester‐bearing brush polymers based on poly(2‐oxazine)s is reported through a combination of cationic ring‐opening polymerization (CROP) of 2‐ethyl‐2‐oxazine and reversible addition‐fragmentation chain transfer (RAFT) polymerization. In this way, a small library of well‐defined (Đ ≤ 1.17) poly(oligo(2‐ethyl‐2‐oxazine) methacrylate) P(OEtOzMA)n brushes with tunable lower critical solution temperature (LCST) behavior and negligible cell toxicity is prepared. Upon deprotection, the phosphonic acid end‐group of the P(OEtOzMA)n brush enables the successful grafting‐onto iron oxide nanoparticles (IONPs). Colloidal stability of the particle suspension in combination with suitable magnetic resonance imaging (MRI) relaxivities demonstrates the potential of these particles for future applications as negative MRI contrast agents

Diagnostic yield and cost analysis of electrocardiographic screening in Swiss paediatric athletes

OBJECTIVES Athletes performing sports on high level are at increased risk for sudden cardiac death. This includes paediatric athletes, even though data on screening strategies in this age group remain scarce. This study aimed to assess electrocardiogram interpretation criteria in paediatric athletes and to evaluate the cost of screening. METHODS National, multicentre, retrospective, observational study on 891 athletes of paediatric age (<18 years) evaluated by history, physical examination and 12-lead electrocardiogram. The primary outcome measure was abnormal electrocardiogram findings according to the International Recommendations for Electrographic Interpretation in Athletes. The secondary outcome measure was cost of screening. RESULTS 19 athletes (2.1%) presented abnormal electrocardiogram findings requiring further investigations, mainly abnormal T-wave inversion. These 19 athletes were predominantly males, performing endurance sports with a mean volume of 10 weekly hours for a mean duration of 6 years of training. Further investigations did not identify any relevant pathology. All athletes were cleared for competition with regular follow-up. Total costs of the screening were 108,860 USD (122 USD per athlete). CONCLUSIONS Our study using the International Recommendations for Electrographic Interpretation in Athletes identified a low count of abnormal findings in paediatric athletes, yet raising substantially the cost of screening. Hence, the utility of electrocardiogram-inclusive screening of paediatric athletes remains to be elucidated by longitudinal data

Self-assembly of oriented antibody-decorated metal–organic framework nanocrystals for active-targeting applications

Vol. 34(21) pp 2106607-1 - 2106607-7Antibody (Ab)-targeted nanoparticles are becoming increasingly important for precision medicine. By controlling the Ab orientation, targeting properties can be enhanced; however, to afford such an ordered configuration, cumbersome chemical functionalization protocols are usually required. This aspect limits the progress of Abs-nanoparticles toward nanomedicine translation. Herein, a novel one-step synthesis of oriented monoclonal Ab-decorated metal-organic framework (MOF) nanocrystals is presented. The crystallization of a zinc-based MOF, Zn₂(mIM₂(CO₃), from a solution of Zn²⁺ and 2-methylimidazole (mIM), is triggered by the fragment crystallizable (Fc) region of the Ab. This selective growth yields biocomposites with oriented Abs on the MOF nanocrystals (MOF*Ab): the Fc regions are partially inserted within the MOF surface and the antibody-binding regions protrude from the MOF surface toward the target. This ordered configuration imparts antibody-antigen recognition properties to the biocomposite and shows preserved target binding when compared to the parental antibodies. Next, the biosensing performance of the system is tested by loading MOF*Ab with luminescent quantum dots (QD). The targeting efficiency of the QD-containing MOF*Ab is again, fully preserved. The present work represents a simple self-assembly approach for the fabrication of antibody-decorated MOF nanocrystals with broad potential for sensing, diagnostic imaging, and targeted drug delivery.Karen Alt, Francesco Carraro, Edwina Jap, Mercedes Linares-Moreau, Raffaele Riccò, Marcello Righetto, Marco Bogar, Heinz Amenitsch, Rania A. Hashad, Christian Doonan, Christoph E. Hagemeyer, and Paolo Falcar

Carbohydrates@MOFs

MOFs have demonstrated outstanding properties for the protection and controlled release of different bio-entities, from proteins to living cells. Carbohydrates, as pure molecules or as a component of proteins and cells, perform essential biological functions. Thus, an understanding of the role of carbohydrates in the formation of MOF-based bio-composites will facilitate their application to biotechnology and medicine. Here, we investigate the role of carbohydrate molecular weight and chemical functionalization in the formation of carbohydrate@MOF composites. We find that chemical functionalization, such as carboxylation, that leads to an enhancement of metal cation concentration at the surface of the molecule triggers the rapid self-assembly of the MOF material, zeolitic-imidazolate framework 8 (ZIF-8). Furthermore, we determine the encapsulation efficiency and measure the release properties of the carbohydrate under controlled conditions. Our findings show that MOFs can be used to prepare a new class of biocomposites for the delivery of carbohydrate-based therapeutics.Efwita Astria, Martin Thonhofer … Weibin Liang … David M. Huang, Christian J. Doonan, Paolo Falcaro ... et al

GPVI and GPIbα Mediate Staphylococcal Superantigen-Like Protein 5 (SSL5) Induced Platelet Activation and Direct toward Glycans as Potential Inhibitors

Background Staphylococcus aureus (S. aureus) is a common pathogen capable of causing life-threatening infections. Staphylococcal superantigen-like protein 5 (SSL5) has recently been shown to bind to platelet glycoproteins and induce platelet activation. This study investigates further the interaction between SSL5 and platelet glycoproteins. Moreover, using a glycan discovery approach, we aim to identify potential glycans to therapeutically target this interaction and prevent SSL5-induced effects. Methodology/Principal Findings In addition to platelet activation experiments, flow cytometry, immunoprecipitation, surface plasmon resonance and a glycan binding array, were used to identify specific SSL5 binding regions and mediators. We independently confirm SSL5 to interact with platelets via GPIbα and identify the sulphated-tyrosine residues as an important region for SSL5 binding. We also identify the novel direct interaction between SSL5 and the platelet collagen receptor GPVI. Together, these receptors offer one mechanistic explanation for the unique functional influences SSL5 exerts on platelets. A role for specific families of platelet glycans in mediating SSL5-platelet interactions was also discovered and used to identify and demonstrate effectiveness of potential glycan based inhibitors in vitro. Conclusions/Significance These findings further elucidate the functional interactions between SSL5 and platelets, including the novel finding of a role for the GPVI receptor. We demonstrate efficacy of possible glycan-based approaches to inhibit the SSL5-induced platelet activation. Our data warrant further work to prove SSL5-platelet effects in viv