Time measurement techniques

The common time measurements as used by the U.S. Air Force Measurements and Standards Laboratory, Aerospace Guidance and Metrology Center (AGMC), Newark Air Force Station, Ohio, are described. Electronic counter time interval measurements are emphasized since this is the most common time comparison measurement in use. The proper use and setting of controls will be covered along with helpful hints and common mistakes to be avoided. Applications of time measurements are described and some of these are timekeeping via Loran-C, TV Line-10, and WWV. Frequency determination using periodic time readings will also be discussed

Inertial navigation/calibration/precise time and frequency capabilities

The Aerospace Guidance and Metrology Center was conceived in 1959 to be the US Air Force Inertial Navigation and Metrology Center. This paper will show the mission capabilities of the Inertial Navigation Maintenance Center and the Air Force Measurement and Standards Laboratory. Highlighted will be the precise time and frequency program developed by AGMC to support Air Force precise time and frequency requirements worldwide. A description of the past, present, and future precise time and frequency activities will be presented

The Mythology of Reason in “Das älteste Systemprogramm”: A Hegelian Project?

The paper aims to investigate the thesis of the so-called Neue Mythologie within the fragment entitled “Das älteste Systemprogramm des deutschen Idealismus” [“The Oldest Systematic Program of German Idealism”]. The latter presents a revolutionary project of social pedagogy linked to the use of the aesthetic character of myth and poetry in the formation of the conscience and the intellect of the people. The program, therefore, formulates a fertile dialogue between the emancipatory potential of the Enlightenment and Jena Romanticism, in that it proposes a re-evaluation of feelings and Sinnlichkeit [sensuousness] in connection to modern rationality and freedom. The links between the rational mythology of the program and Hegelian philosophy will be explored, starting from his early writings, which are strictly concerned with the importance of a popular and sensuous religion (Volksreligion). Secondly, the work will retrace the same sensuous externalization of philosophical ideas within the relationships between art, religion and philosophy in the mature system, addressing the problem of Hegel’s change of heart regarding art and mythology between the two phases of his thought. In the end the value of symbolical mediation of concepts and idea will be established

Synthesis of proazaphosphatranes and their applications in organic synthesis

This study was aimed at finding useful applications for proazaphosphatranes in organic synthesis. We also sought more practical syntheses for this class of compounds. These objectives have been met and the syntheses of three new proazaphosphatranes are also reported;This dissertation is divided into ten chapters. Only chapters 1, 3 and 10 are not manuscripts of papers either published or in the process of being submitted for publication. The first chapter outlines background information on proazaphosphatranes. In the second chapter, the syntheses of the three new proazaphosphatranes P(Me2CHCH2NCH2CH 2)3N, P(Me3CCH2NCH2CH 2)3N, and P(Me2CHNCH2CH2)(HNCH 2CH2)2N are reported. The first two bases are strong and highly stable to oligomerization while the last is highly unstable in this regard and can be studied only in solution or within 24 h of its preparation. The third chapter deals with the modification of the synthesis of the intermediates leading to the highly basic and stable proazaphosphatrane P(MeLCHNCH 2CHL)3N. Although this chapter is not a paper, it is in the process of being submitted to Iowa State Research Foundation (ISURF) as a Record of Invention;The six chapters that follow are dedicated to the applications of the proazaphosphatranes in organic synthesis. Thus, in the fourth chapter, the use of proazaphosphatranes in the preparation of glutaronitriles from aldehydes and acetonitrile or from methylene-interrupted (beta,gamma-unsaturated nitriles in benzene is covered. In the fifth chapter, the use of proazaphosphatranes in the synthesis of beta-hydroxy nitriles in the presence of MgSO4 is reported. The preparation of (beta-nitroalkanols is described in Chapter 6. In Chapter 7, proazaphosphatranes are used to promote Wittig-like reactions and also the synthesis of coumarins. Chapter 8 covers the use of proazaphosphatranes in Michael addition reactions of alcohols, nitroalkanes and imines derived from (alpha-amino esters. In Chapter 9, the synthesis of oxazolidines with excellent anti-selectivity is disclosed. The final chapter contains a brief conclusion that outlines the objectives of the project that have been met

Evaluation and identification of single-cross maize hybrids for use in tester development.

Master of Science in Plant Breeding. University of KwaZulu-Natal, Pietermaritzburg, 2018.Development of testers from new inbred lines that are high yielding and high discriminating abilities in diverse environments, and in stress conditions is very important in maize breeding in southern and eastern Africa. Genetic gain decreases when new lines are combined with old testers. It is, therefore, important to develop new testers that perform better in harsh environmental conditions to replace the old single-cross testers; CML 312 x CML 442 (heterotic group A) and CML 444 x CML 395 (heterotic group B). These are currently dominating the maize breeding programmes at the Agricultural Research Council (ARC) and most of the National Agricultural Research stations (NARS) in eastern and southern Africa. The objectives of this study were therefore; i) to identify elite single-cross hybrids suitable for further evaluation as potential testers in development of three-way cross hybrids, ii) to determine the correlations between grain yield and secondary traits in single-cross maize hybrids, and iii) to estimate phenotypic and genetic variance components, heritability and genetic advances for yield and its related components in single-cross maize hybrids. The trials were established under three different environments which are: random drought (RD), optimum environment (OPT) and low nitrogen (Low N) at ARC Potchefstroom and Cedara using alpha lattice 0, 1 design (32 x 5). The single-cross hybrids used in this study were obtained from CIMMYT Zimbabwe and they belong to two different heterotic groups as follows;, heterotic group A with 160 entries among which 155 were experimental single-cross hybrids and five were check entries and heterotic group B with 160 entries among which 157 were experimental single-cross hybrids and three were hybrid checks. High significant differences (P< 0.01) among single-cross hybrids were observed on days to 50% anthesis (AD), grain yield (GY), ear height (EH), and ears per plant (EPP) in heterotic group B under optimum environment. Hybrid 139 had a mean yield of 8.65 t/ha, which was higher than the average grain yield of 6.22 t/ha. Days to 50% anthesis (AD), anthesis-silk interval (ASI), plant height (PH), and EH varied significantly (p<0.01) among single-cross hybrids in the low nitrogen environment. Hybrid 65 had a mean yield of 4.04 t/ha, which was higher than the average yield of 2.29 t/ha. Days to 50% anthesis were slightly higher in low nitrogen environment than in optimal environment. Hybrid 92 had a mean yield of 7.53 t/ha, which was higher than the average yield of 4.77 t/ha in random drought environment. As in heterotic group B, significant variations were observed in heterotic group A, in random drought and optimum environments. Grain yields of 9.44 t/ha and 6.42 t/ha for maize hybrids 134 and 52 were higher than average mean yields of 6.75 t/ha and 3.43 t/ha from optimum and random drought environments, respectively. Hybrids with higher trait values than the average may be advanced for further use in breeding in their respective environments. Maize single-cross hybrids 1, 23, 127, 15, 122, 8, 134, 109, 34, and 31 from heterotic group A and 69, 81, 65, 97, 92, 40, 117, 58, 101, and 44 from heterotic group B were selected for further use in breeding. The hybrids had consistently higher mean yields across the environments. Significant, positive and negative correlations were observed among secondary traits in all environments. Yield (t/ha) was positively correlated with cob length (CBL), EH, field weight (FW), grain weight (GW) and shelling percentage (SP). It was however, negatively correlated with days to 50% silking (SD) and days to 50% anthesis (AD). A breeding programme aimed at improving CBL, EH, FW, GW and SP and reducing traits SD and AD may indirectly result in improvement of maize yields in random and optimum environments. High genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV) were observed for ASI, yield t/ha, PH and ear height therefore, and selection can be done. Improvement of maize yield based on AD and ASI selection would be successful due to their high broad sense heritability estimates. The genetic advance observed in this study were high and therefore some trait values can be increased in the next generation through selection

Synthetic accelerograms for hazard evaluation and response-history analysis of buildings

Non-linear Time History Analysis (NLTHA) of structures is the most sophisticated tool used to understand the real dynamic behaviour of structures (FIB, 2012). The goodness of results relies on an accurate definition of the materials properties, their hysteretic behaviour and the geometry of the structure to be examined, as well as on the definition of the dynamic excitations represented by acceleration time histories. These accelerograms must represent, on average, the hazard of the site under examination, commonly represented by an acceleration response spectrum. Usually the target response spectrum is defined, in a Probabilistic (PSHA) or Deterministic (DSHA) Seismic Hazard Assessment, through Ground Motion Prediction Equations (GMPEs). Therefore, ground motions should have magnitude, source distance and focal mechanism consistent with the sources that control the hazard at the site of interest. Moreover, site soil conditions and the possibility of experiencing near fault effects such as directivity and fling-step needs to be considered (NIST, 2011). Usually, acceleration time histories are selected from databases of records (e.g. the European Strong Motion (ESM) database (Luzi et al., 2016) in order to satisfy all the above-mentioned characteristics and to match, over a defined range of periods, the target response spectrum. As the tolerance on the variability of the selection parameters becomes stronger, the lack of data becomes evident and some modifications (e.g. linear scaling) of the original recorded ground motions are needed if an adequate number of ground motion is to be used. A source of time histories could be the generation of artificial accelerograms (Gasparini and Vanmarke, 1976) or the use of the \u201cresponse spectrum matching\u201d technique (Al Atik and Abrahamson, 2010; Grant and Diaferia, 2013). However, these techniques have no physical meaning and there are concerns that their use could lead to biased results (Bazzurro and Luco, 2006; Iervolino et al., 2010). A viable alternative is to use synthetic accelerograms generated from a simulation of the source rupture and wave propagation. In this work, a direct link between hazard and response-history analysis is established. Synthetic seismograms are used to define the hazard as described by the Neo Deterministic Seismic Hazard Assessment (NDSHA) (Panza et. al., 2001, 2012; Fasan et al., 2016) and, as a logical consequence, to perform NLTHA on a selected building. A comparison of the results of NLTHAs obtained with natural and synthetic records confirms that physics-based simulations are a valuable tool in structural analysis. Moreover, the NDSHA method is applied to the site of Norcia and predicted spectral acceleration are compared with the recorded one during the event of the 30th of October 2016. Using NLTHAs, structural demands predicted using the real records and the synthetic ones used in the NDSHA are compared, showing that simulated accelerograms can be used to predict real non-linear demands of future earthquakes

Distinct blood and visceral adipose tissue regulatory T cell and innate lymphocyte profiles characterize obesity and colorectal cancer

Visceral adipose tissue (VAT) is a main site where metabolic and immunologic processes interplay to regulate, at local and systemic level, the inflammatory status and immune response. Obesity-associated inflammation and immune dysfunctions are inextricably linked to tumor but, in spite of intense efforts, the mechanisms underpinning this asso- ciation remain elusive. In this report, we characterized the profile of VAT-associated and circulating innate lymphocyte and regulatory T (T reg ) cell subsets underlying inflammatory conditions, such as obesity and colorectal cancer (CRC). Analysis of NK, NKT-like, γδ T, and T reg cell populations in VAT and blood of healthy lean subjects revealed that CD56 hi NK and OX40 + T reg cells are more abundant in VAT with respect to blood. Conversely, CD56 dim NK and total T reg cells are most present in the circulation, while γδ T lymphocytes are uniformly distributed in the two compartments. Interestingly, a reduced frequency of circulating activated T reg cells, and a concomitant preferential enrichment of OX40- expressing T reg cells in VAT, were selectively observed in obese (Ob) subjects, and directly correlated with body mass index. Likewise, CRC patients were characterized by a specific enrichment of VAT-associated NKT-like cells. In addition, Ob and CRC-affected individuals shared a significant reduction of the V γ 9V δ 2/ γδ T cell ratio at systemic level. The alterations in the relative proportions of T reg and NKT-like cells in VAT were found to correlate with the content of pro- and anti-inflammatory polyunsaturated fatty acids (PUFA), respectively. Overall, these results provide evidence for distinct alterations of the immune cell repertoire in the periphery with respect to the VAT microenvironment that uniquely characterize or are shared by different inflammatory conditions, such as obesity and CRC, and suggest that VAT PUFA composition may represent one of the factors that contribute to shape the immune phenotypes

Picturing the Membrane‐assisted Choreography of Cytochrome P450 with Lipid Nanodiscs

Cytochrome P450, a family of monooxygenase enzymes, is organized as a catalytic metabolon, and requires enzymatic partners as well as environmental factors that tune its complex dynamic activity. P450 and its reducing counterparts are membrane‐bound proteins which are believed to dynamically interact to form functional complexes. Increasing experimental evidence signifies the role (s) of protein‐lipid interactions in P450’s catalytic function and efficiency. The challenges posed by the membrane have severely limited high‐resolution understanding of the molecular interfaces of these interactions. Nevertheless, recent NMR studies have provided piercing insights into the dynamic structural interactions that enable the function of P450. In this review, we will discuss different biomimetic approaches relevant to unveil molecular interplays at the membrane, focusing on our recent work on lipid‐nanodiscs. We also highlight the need to expand the use of nanodiscs, and the power of a combination of cutting‐edge solution and solid‐state NMR techniques, to study the dynamic structures of P450 as well as other membrane‐proteins.Cytochrome P450 is organized as a catalytic metabolon. Experimental evidence discloses the role (s) of protein‐lipid interactions in P450’s catalytic function. In this review, the authors discuss biomimetic approaches relevant to unveil molecular interplays at the membrane interface, focusing on their recent work on lipid‐nanodiscs, and highlight the need to expand the use of nanodiscs to other membrane‐protein research areas.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146408/1/cphc201800444_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146408/2/cphc201800444.pd