Radiocarbon Dioxide detection based on Cavity Ring-Down Spectroscopy and a Quantum Cascade Laser

Monitoring of radiocarbon ($^{14}$C) in carbon dioxide is demonstrated using mid-infrared spectroscopy and a quantum cascade laser. The measurement is based on cavity ring-down spectroscopy, and a high sensitivity is achieved with a simple setup. The instrument was tested using a standardised sample containing elevated levels of radiocarbon. Radiocarbon dioxide could be detected from samples with an isotopic ratio $^{14}$C/C as low as 50 parts-per-trillion, corresponding to an activity of 5 kBq/m$^3$ in pure CO$_2$, or 2 Bq/m$^3$ in air after extraction of the CO$_2$ from an air sample. The instrument is simple, compact and robust, making it the ideal tool for on-site measurements. It is aimed for monitoring of radioactive gaseous emissions in nuclear power environment, during the operation and decommissioning of nuclear power plants. Its high sensitivity also makes it the ideal tool for the detection of leaks in radioactive waste repositories.Comment: 5 pages, 4 figure

Quantifying slope-channel coupling in an active gully and fan complex at Tarndale, Waipaoa catchment, New Zealand

Two RIEGL LMS‐Z420i scanner surveys (November 2007 and November 2008) of the Tarndale Gully complex and its associated fan were used to generate a digital elevation model (DEM) of difference in order to quantify gully‐fan‐channel connectivity. The Te Weraroa Stream, into which the first order Tarndale system feeds, is buffered from sediment generated by the gully complex by a fan. Sediment yields and the role of the fan in buffering Te Weraroa Stream are inferred from the TLS of the entire complex. DEM analysis suggests that c.25% of material derived from the gully is buffered from the stream by being stored in the fan. This figure was applied to fan behaviour since December 2004, mapped on nine successive occasions using detailed GPS surveys to get a longer‐term picture of sediment supply within the system and appraise a qualitative assessment of connectivity constructed on the basis of fan behaviour alone

Band Spectral Regression with Trending Data

Band spectral regression with deterministic and stochastic trends is considered. It is shown that conventional trend removal by regression in the time domain prior to band spectral regression leads to biased and inconsistent estimates of the parameters in a model with frequency dependent coefficients. Time domain and frequency domain procedures for dealing with this problem are examined. Trend removal in the frequency domain produces unbiased estimates and is recommended. An asymptotic theory is developed and the two cases of stationary data and cointegrated nonstationary data are compared. Efficient band spectral regression estimators and associated inferential methods are provided for models with deterministic and stochastic trends. Some supporting Monte Carlo evidence is presented. An empirical application to the present value model of stock prices is discussed. After removing trends in the frequency domain, we show that, while stock prices and dividends have significant coherence at low frequencies, transitory fluctuations in dividends (i.e., less than 3 years) do not have significant coherence with stock price movements.Band spectral regression, deterministic and stochastic trends, nonstationary time series, integrated process, present value model of stock prices

USNA Classroom Utilization Study - Final Report - Analysis of Issues Affecting Classroom Utilization at the United States Naval Academy

EMBA Project ReportEXECUTIVE SUMMARY: Demand on Naval Academy facilities has increased due to sustained growth in the Academy’s academic programs in new areas such as cyber studies, language and cultural studies, and increased emphasis on conferring Science, Technology, Engineering & Mathematics (STEM) degrees. In addition, the pedagogical requirements of training the Brigade of Midshipmen in all aspects of their mental, moral and physical development has evolved significantly over the years; requiring new types of teaching, learning spaces and processes that have had significant impact on the usage of classrooms and laboratories at the Academy. This pedagogy has been formalized into a series of processes and regimens that we identify as constraints in this study. These constraints act collectively to define the actual utilization of every facility at the Naval Academy. In addition, they form the basis for almost all of the business rules used by the Academic Dean’s office in their mission of facilitating the mental development of the Brigade, and ultimately become the drivers for new facilities requirements. Despite the restrictive nature of these constraints, the Naval Academy has performed above the national average in its utilization of its classrooms, and as of the fall 2010 semester, has achieved a current classroom average utilization rate of 74%. While this is noteworthy, we believe that by making a few minor adjustments which would not represent a significant departure from its cultural norms, the Academy can utilize its existing classrooms at an even higher level. In this study, we present the constraints pertaining to classroom utilization in five categories; Physical, Student Body, Faculty, Traditional and Technology. We briefly examine each constraint and qualitatively explain its impact on facilities utilization. We recognize that constraints are a reality of doing business and that especially in circumstances such as at the Naval Academy they are even highly desired, valued and part of the cultural heart of the institution. However, we present a series of recommendations that encourage new examinations of the constraints in light of the constrained facilities construction budget in the Department of the Navy and in response to the Naval Academy’s sense of urgency in identifying space for the emerging curriculum requirements in Cyber Studies. We wish to highlight several of these recommendations that, in our assessment, appear to be palatable and executable in the near future without significant disruption to the norms at the Academy; _ Reclaim a seventh daily period of instruction by shortening the noon meal period and beginning the afternoon class sessions earlier. _ Adhere more closely to the Academic Dean guidelines on appropriate sizes of classes and strictly limit the number of small classes (fewer than 16 Midshipmen) to specialized instances. _ Schedule and assign classrooms and labs at the Division level vs. independent Department-led academic scheduling. These opportunities, among others that we present in our recommendations, will have real and immediate impact on the utilization of classrooms at the Naval Academy and can be accomplished in incremental steps or in tandem. Delivering future leaders of the Navy to the Fleet on schedule and on budget is no small task and we applaud the Naval Academy leadership in their dedicated efforts. We hope that this study encourages further dialogue on how to maximize all of the academic facilities and associated resources that are currently available to meet these demands.For Mr. Robert C. Parsons, Chief Financial Officer, USNAhttp://archive.org/details/usnaclassroomuti10945706

The Reddening-Free Decline Rate Versus Luminosity Relationship for Type Ia Supernovae

We develop a method for estimating the host galaxy dust extinction for type Ia supernovae based on an observational coincidence first noted by Lira (1995), who found that the B-V evolution during the period from 30-90 days after V maximum is remarkably similar for all events, regardless of light curve shape. This fact is used to calibrate the dependence of the B(max)-V(max) and V(max)-I(max) colors on the light curve decline rate parameter delta-m15, which can, in turn, be used to separately estimate the host galaxy extinction. Using these methods to eliminate the effects of reddening, we reexamine the functional form of the decline rate versus luminosity relationship and provide an updated estimate of the Hubble constant of Ho = 63.3 +- 2.2(internal) +- 3.5(external) km/s/Mpc.Comment: 32 pages, 10 figures, AJ 1999 in pres

CCAAT/enhancer binding protein β expression is increased in the brain during HIV-1-infection and contributes to regulation of astrocyte tissue inhibitor of metalloproteinase-1

Human immunodeficiency virus (HIV)-1-associated neurocognitive disorders (HAND) associated with infection and activation of mononuclear phagocytes (MP) in the brain, occur late in disease. Infected/activated MP initiate neuroinflammation activating glial cells and ultimately disrupting neuronal function. Astrocytes secrete tissue inhibitor of metalloproteinase (TIMP)-1 in response to neural injury. Altered TIMP-1 levels are implicated in several CNS diseases. CCAAT enhancer-binding protein ß (C/EBPß), a transcription factor, is expressed in rodent brains in response to neuroinflammation, implicating it in Alzheimer’s, Parkinson’s, and HAND. Here, we report that C/EBPß mRNA levels are elevated and its isoforms differentially expressed in total brain tissue lysates of HIV-1-infected and HIV-1 encephalitis patients. In vitro, HAND-relevant stimuli additively induce C/EBPß nuclear expression in human astrocytes through 7 days of treatment. Over-expression of C/EBPß increases TIMP-1 promoter activity, mRNA, and protein levels in human astrocytes activated with interleukin-1ß. Knockdown of C/EBPß with siRNA decreases TIMP-1 mRNA and protein levels. These data suggest that C/EBPß isoforms are involved in complex regulation of astrocyte TIMP-1 production during HIV-1 infection; however, further studies are required to completely understand their role during disease progression

Vangl2-Regulated Polarisation of Second Heart Field-Derived Cells Is Required for Outflow Tract Lengthening during Cardiac Development.

Planar cell polarity (PCP) is the mechanism by which cells orient themselves in the plane of an epithelium or during directed cell migration, and is regulated by a highly conserved signalling pathway. Mutations in the PCP gene Vangl2, as well as in other key components of the pathway, cause a spectrum of cardiac outflow tract defects. However, it is unclear why cells within the mesodermal heart tissue require PCP signalling. Using a new conditionally floxed allele we show that Vangl2 is required solely within the second heart field (SHF) to direct normal outflow tract lengthening, a process that is required for septation and normal alignment of the aorta and pulmonary trunk with the ventricular chambers. Analysis of a range of markers of polarised epithelial tissues showed that in the normal heart, undifferentiated SHF cells move from the dorsal pericardial wall into the distal outflow tract where they acquire an epithelial phenotype, before moving proximally where they differentiate into cardiomyocytes. Thus there is a transition zone in the distal outflow tract where SHF cells become more polarised, turn off progenitor markers and start to differentiate to cardiomyocytes. Membrane-bound Vangl2 marks the proximal extent of this transition zone and in the absence of Vangl2, the SHF-derived cells are abnormally polarised and disorganised. The consequent thickening, rather than lengthening, of the outflow wall leads to a shortened outflow tract. Premature down regulation of the SHF-progenitor marker Isl1 in the mutants, and accompanied premature differentiation to cardiomyocytes, suggests that the organisation of the cells within the transition zone is important for maintaining the undifferentiated phenotype. Thus, Vangl2-regulated polarisation and subsequent acquisition of an epithelial phenotype is essential to lengthen the tubular outflow vessel, a process that is essential for on-going cardiac morphogenesis

The effects of inspiratory muscle training in older adults

Purpose: Declining inspiratory muscle function and structure and systemic low-level inflammation and oxidative stress may contribute to morbidity and mortality during normal ageing. Therefore, we examined the effects of inspiratory muscle training (IMT) in older adults on inspiratory muscle function and structure and systemic inflammation and oxidative stress, and re-examined the reported positive effects of IMT on respiratory muscle strength, inspiratory muscle endurance, spirometry, exercise performance, physical activity levels (PAL) and quality of life (QoL). Methods: Thirty-four healthy older adults (68 ± 3 years) with normal spirometry, respiratory muscle strength and physical fitness were divided equally into a pressure-threshold IMT or sham-hypoxic placebo group. Before and after an 8 week intervention, measurements were taken for dynamic inspiratory muscle function and inspiratory muscle endurance using a weighted plunger pressure-threshold loading device, diaphragm thickness using B-mode ultrasonography, plasma cytokine concentrations using immunoassays, DNA damage levels in peripheral blood mononuclear cells (PBMC) using Comet Assays, spirometry, maximal mouth pressures, exercise performance using a six minute walk test, PAL using a questionnaire and accelerometry, and QoL using a questionnaire

CTCF-mediated transcriptional regulation through cell type-specific chromosome organization in the {\beta}-globin locus

The principles underlying the architectural landscape of chromatin beyond the nucleosome level in living cells remains largely unknown despite its potential to play a role in mammalian gene regulation. We investigated the 3-dimensional folding of a 1 Mbp region of human chromosome 11 containing the {\beta}-globin genes by integrating looping interactions of the insulator protein CTCF determined comprehensively by chromosome conformation capture (3C) into a polymer model of chromatin. We find that CTCF-mediated cell type specific interactions in erythroid cells are organized to favor contacts known to occur in vivo between the {\beta}-globin locus control region (LCR) and genes. In these cells, the modeled {\beta}-globin domain folds into a globule with the LCR and the active globin genes on the periphery. By contrast, in non-erythroid cells, the globule is less compact with few but dominant CTCF interactions driving the genes away from the LCR. This leads to a decrease in contact frequencies that can exceed 1000-fold depending on the stiffness of the chromatin and the exact positioning of the genes. Our findings show that an ensemble of CTCF contacts functionally affects spatial distances between control elements and target genes contributing to chromosomal organization required for transcription.Comment: Full article, including Supp. Mat., is available at Nucleic Acids Research, doi: 10.1093/nar/gks53