Liquid hydrogen densitometer utilizes open-ended microwave cavity

Open-ended microwave cavity directly measures the density of flowing liquid, gaseous, or two-phase hydrogen. Its operation is based on derived relations between the cavity resonant frequency and the dielectric constant and density of hydrogen

Ersatzes of Fetal Bovine Serum: a survey of current options in cell culture: Example of the Regenerative Therapy Unit/CPR/CHUV

Cell culture began in the 19th-century when a physiologist, Sydney Ringer, developed a solution capable of maintaining a beating frog heart outside of the body. He was able to maintain the tissue under living conditions by submerging in an isotonic salt solution composed of sodium chloride, potassium chloride, calcium chloride and sodium bicarbonate. (1) A buffering system, usually phenol red, was also added to the culture media in order to monitor a pH at physiological ranges. In the years 1907 to 1910, specific methodology for cell culture was established by Ross Granville Harrison. He was the first to be able to observe neural growth. In his experimentation, he placed fragments of embryonic tissues from frog medullary cords on cover slips of glass slides and sealed them with clotted lymph. He indeed generated the first moist chamber. (2) Apart from the nutrition, animal cells also need specific culture conditions; they are kept in incubators in a controlled humidified gas mixture of 5% CO2 and 95% O2 under a physiological temperature of 37° C. The CO2 is essential to maintain the pH of media because without CO2 the medium becomes alkaline and compromises cellular survival and proliferation. Cell culture techniques made significant advances in the 1940s and 1950s to support research in virology. As viruses require the components of infected cells to reproduce themselves, large scale manufacturing of viral material in safe conditions necessitates co-culture with animal cells. For instance, the vaccine for Polio was produced with the aide of co-cultured fetal cells. Harry Eagle, an American pathologist, defined the minimal requirement in 1955 for the Hela cell line (isolated from a human uterus Carcinoma at Johns Hopkins Hospital) and mouse fibroblasts, laying down the fundamental principles of mammalian culture. Eagle proved that 27 elements were essential for the growth of mammalian culture, and his medium Eagle's minimal essential medium (Eagle's MEM) contains various amino acids, glucose, vitamins, isotonic salt solutions and an whole animal or human serum. (3) All of the elements were defined as the base medium without the serum component. Dulbecco formulated a modified version of the Eagle's MEM, Dulbecco's MEM (DMEM) around the same time period, with 4 times more vitamins as reported in Table 1. Historically cell culture has been done with the addition of serum to the culture medium to mimic the physiological condition of the body. The source of the serums can differ; it can be human serum, horse serum or cattle serum among the most common. Serum provides the cells with nutrients, attachment factors, growth factors and hormones, binding and transport proteins, spreading factors, fatty acids, lipids and protease-inhibitors. All of these factors are essential for proliferation and differentiation of cells in culture systems

Analysis of electromagnetic waves on a dielectric rod immersed in a plasma including a discussion of diagnostic applications

Guided electromagnetic waves propagating along lossless dielectric rod immersed in isotropic and uniaxial plasmas determined for applications to plasma diagnostic

Student Satisfaction with Canvas Use in Face-to-Face Courses at Colorado Mountain College

By examining the relationship between the use of LMS tools and student course satisfaction, institutions can purposefully target areas most in need of improvement. The inconsistency in the application and use of LMS tools has resulted in a fragmenting of the student experience and has had a potentially negative affect on student attitudes toward its use. In order to address these issues and to support CMC’s mission, college leadership has created a minimum usage requirement for Canvas in all credit courses. This evaluation aims to provide insight for improving the use of Canvas tools and increasing student course satisfaction in F2F courses at CMC. Drawing on Tinto’s (1975) model of persistence, the use of learning management systems and resultant satisfaction in the classroom is a contributing factor to a student’s decision to persist in a course. Davis’ (1993) technology acceptance model (TAM) also informed the research as it specifies the causal relationships between several factors, in particular, perceived usefulness, ease of use, and satisfaction. The Context and Product components of the CIPP evaluation model were used to guide the determination of the overall quality and merit of the mandated Canvas usage program. Based on the findings from a quantitative survey, the researcher was able to make six specific recommendations to improve the program centered around increased LMS training and support for faculty and students, the demonstration of a measurable positive impact on student learning for new Canvas tool or functionality adoption, and regular and consistent feedback from faculty and students

Virtual Entanglement and Reconciliation Protocols for Quantum Cryptography with Continuous Variables

We discuss quantum key distribution protocols using quantum continuous variables. We show that such protocols can be made secure against individual gaussian attacks regardless the transmission of the optical line between Alice and Bob. This is achieved by reversing the reconciliation procedure subsequent to the quantum transmission, that is, using Bob's instead of Alice's data to build the key. Although squeezing or entanglement may be helpful to improve the resistance to noise, they are not required for the protocols to remain secure with high losses. Therefore, these protocols can be implemented very simply by transmitting coherent states and performing homodyne detection. Here, we show that entanglement nevertheless plays a crucial role in the security analysis of coherent state protocols. Every cryptographic protocol based on displaced gaussian states turns out to be equivalent to an entanglement-based protocol, even though no entanglement is actually present. This equivalence even holds in the absence of squeezing, for coherent state protocols. This ``virtual'' entanglement is important to assess the security of these protocols as it provides an upper bound on the mutual information between Alice and Bob if they had used entanglement. The resulting security criteria are compared to the separability criterion for bipartite gaussian variables. It appears that the security thresholds are well within the entanglement region. This supports the idea that coherent state quantum cryptography may be unconditionally secure.Comment: 18 pages, 6 figures. Submitted to QI

Effect of velocity profile distortion in circular transverse-field electromagnetic flowmeters

Effect of velocity profile distortion in circular transverse-field electromagnetic flowmeter

HOST instrumentation R and D program overview

The turbine hot-section technology (HOST) Instrumentation R&D program focuses on two main classes of instrumentation: (1) those that characterizes the environment around the turbine engine components, which include gas flows measurement, gas temperatures, and heat fluxes; (2) to characterize the effect of the environment on the turbine engine components, which include strain measurements and an optical system to structural responses such as cracking, buckling, spalling, carbon buildup. The HOST Instrumentation R&D program concentrates on the critical measurements that can not be made by commercially available instruments or with instruments that are already in development. The measurements of strain and gas flow are emphasized, these measurements are extremely critical to the success of the HOST program and the HOST requirements differ from the current state of the art by a considerable margin

Chiral symmetry breaking and topology for all N

We investigate spontaneous chiral symmetry breaking in SU(N) gauge theories at large N using overlap fermions. The exact zero modes and the low-lying modes of the Dirac operator provide the tools to gain insight into the interplay between chiral symmetry breaking and topology. We find that topology indeed drives chiral symmetry breaking at N=3 as well as at large N. By comparing the results on various volumes and at different lattice spacings we are able to show that our conclusions are not affected by finite volume effects and also hold in the continuum limit. We then address the question whether the topology can be usefully described in terms of instantons.Comment: Talk at Lattice 2003 (chiral); 3 pages, 2 figures, espcrc2.st

Proposal for a loophole-free Bell test using homodyne detection

We propose a feasible optical setup allowing for a loophole-free Bell test with efficient homodyne detection. A non-gaussian entangled state is generated from a two-mode squeezed vacuum by subtracting a single photon from each mode, using beamsplitters and standard low-efficiency single-photon detectors. A Bell violation exceeding 1% is achievable with 6-dB squeezed light and an homodyne efficiency around 95%. A detailed feasibility analysis, based upon the recent generation of single-mode non-gaussian states, confirms that this method opens a promising avenue towards a complete experimental Bell test.Comment: 4 pages RevTex, 2 figure

Use of Statin Therapy to Reduce Cardiovascular Risk in Older Patients

Background. Cardiovascular disease is the principal cause of mortality in older individuals, and more than 80% of deaths due to coronary heart disease or stroke occur in patients over 65 years of age. Hyperlipidemia is one of the main modifiable risk factors for cardiovascular disease. Current guidelines recommend the use of statins to reduce low-density lipoprotein cholesterol to appropriate targets based on an individual's cardiovascular risk, and clearly state that older age should not be a barrier to treatment. Despite extensive evidence demonstrating clear benefit with statin therapy in older individuals, this population remains chronically undertreated. Scope. This paper provides an overview of the current evidence available regarding the efficacy and safety of statin therapy to reduce cardiovascular risk in older patients. We use hypothetical case studies to address some of the questions frequently posed by physicians responsible for the cardiovascular health of older patients. Conclusions. Various factors may account for the failure to provide appropriate treatment, including a lack of awareness of clinical benefits and perceived safety issues. However, if current guidelines are followed and older patients treated to appropriate LDL-C goals, the likelihood of cardiovascular events will be reduced in this high-risk population. Employing an evidence-based approach to the management of cardiovascular risk in older patients is likely to yield benefits in terms of overall cardiovascular burden