An analysis of the general content, grade placement, and philosophy of state courses of study in arithmetic for grades one to six.

Thesis (Ed.M.)--Boston Universit

The Manchester occulting mask imager (MOMI) - first results on the environment of P Cygni

The design and first use of the Manchester occulting mask imager (MOMI) is described. This device, when combined with the Cassegrain or Ritchey-Chretien foci of large telescopes, is dedicated to the imagery of faint line emission regions around bright central sources. Initial observations, with MOMI on the Nordic Optical telescope (NOT), of the V=4.8 mag P~Cygni environment, have revealed a $\geq$~5~arcmin long [NII] 6584A emitting filament projecting from the outer nebular shell of this luminous blue variable (LBV) star. The presence of a mono-polar lobe older than both the inner (22 arcsec diameter) and outer (1.6 arcmin diameter) shells is suggested.Comment: 4 pages, 4 figures, accepted MNRAS 1998 June 1

Trade-off coding for universal qudit cloners motivated by the Unruh effect

A "triple trade-off" capacity region of a noisy quantum channel provides a more complete description of its capabilities than does a single capacity formula. However, few full descriptions of a channel's ability have been given due to the difficult nature of the calculation of such regions---it may demand an optimization of information-theoretic quantities over an infinite number of channel uses. This work analyzes the d-dimensional Unruh channel, a noisy quantum channel which emerges in relativistic quantum information theory. We show that this channel belongs to the class of quantum channels whose capacity region requires an optimization over a single channel use, and as such is tractable. We determine two triple-trade off regions, the quantum dynamic capacity region and the private dynamic capacity region, of the d-dimensional Unruh channel. Our results show that the set of achievable rate triples using this coding strategy is larger than the set achieved using a time-sharing strategy. Furthermore, we prove that the Unruh channel has a distinct structure made up of universal qudit cloning channels, thus providing a clear relationship between this relativistic channel and the process of stimulated emission present in quantum optical amplifiers.Comment: 26 pages, 4 figures; v2 has minor corrections to Definition 2. Definition 4 and Remark 5 have been adde

Public health and landfill sites

Landfill management is a complex discipline, requiring very high levels of organisation, and considerable investment. Until the early 1990’s most Irish landfill sites were not managed to modern standards. Illegal landfill sites are, of course, usually not managed at all. Landfills are very active. The traditional idea of ‘put it in the ground and forget about it’ is entirely misleading. There is a lot of chemical and biological activity underground. This produces complex changes in the chemistry of the landfill, and of the emissions from the site. The main emissions of concern are landfill gases and contaminated water (which is known as leachate). Both of these emissions have complex and changing chemical compositions, and both depend critically on what has been put into the landfill. The gases spread mainly through the atmosphere, but also through the soil, while the leachate (the water) spreads through surface waters and the local groundwater. Essentially all unmanaged landfills will discharge large volumes of leachate into the local groundwater. In sites where the waste accepted has been properly regulated, and where no hazardous wastes are present, there is a lot known about the likely composition of this leachate and there is some knowledge of its likely biological and health effects. This is not the case for poorly regulated sites, where the composition of the waste accepted is unknown. It is possible to monitor the emissions from landfills, and to reduce some of the adverse health and environmental effects of these. These emissions, and hence the possible health effects, depend greatly on the content of the landfill, and on the details of the local geology and landscape. There is insufficient evidence to demonstrate a clear link between cancers and exposure to landfill, however, it is noted that there may be an association with adverse birth outcomes such as low birth weight and birth defects. It should be noted, however, that modern landfills, run in strict accordance with standard operation procedures, would have much less impact on the health of residents living in proximity to the site

London or New York: where and when does the gold price originate?

We investigate the Information Shares (ISs) of the two main centres of gold trading, over a 25-year period, using nonoverlapping 4-month windows. We find that neither London nor New York is dominant in terms of price IS, that the dominant market switches from time to time and that these switches do not appear to be very clearly linkable to macroeconomic or political events

Advances in Engineering the Fly Genome with the CRISPR-Cas System.

Drosophila has long been a premier model for the development and application of cutting-edge genetic approaches. The CRISPR-Cas system now adds the ability to manipulate the genome with ease and precision, providing a rich toolbox to interrogate relationships between genotype and phenotype, to delineate and visualize how the genome is organized, to illuminate and manipulate RNA, and to pioneer new gene drive technologies. Myriad transformative approaches have already originated from the CRISPR-Cas system, which will likely continue to spark the creation of tools with diverse applications. Here, we provide an overview of how CRISPR-Cas gene editing has revolutionized genetic analysis in Drosophila and highlight key areas for future advances

Phosphorylation of Subunit Proteins of Intermediate Filaments from Chicken Muscle and Nonmuscle Cells

The phosphorylation of the subunit proteins of intermediate (10-nm) filaments has been investigated in chicken muscle and nonmuscle cells by using a two-dimensional gel electrophoresis system. Desmin, the 50,000-dalton subunit protein of the intermediate filaments of muscle, had previously been shown to exist as two major isoelectric variants--alpha and ß --in smooth, skeletal, and cardiac chicken muscle. Incubation of skeletal and smooth muscle tissue with 32PO4{}3- reveals that the acidic variant, alpha -desmin, and three other desmin variants are phosphorylated in vivo and in vitro. Under the same conditions, minor components of alpha - and ß -tropomyosin from skeletal muscle, but not smooth muscle, are also phosphorylated. Both the phosphorylated desmin variants and the nonphosphorylated ß -desmin variant remain insoluble under conditions that solubilize actin and myosin filaments, but leave Z-discs and intermediate filaments insoluble. Primary cultures of embryonic chicken muscle labeled with 32PO4{}3- possess, in addition to the desmin variants described above, a major nonphosphorylated and multiple phosphorylated variants of the 52,000-dalton, fibroblast-type intermediate filament protein (IFP). Filamentous cytoskeletons, prepared from primary myogenic cultures by Triton X-100 extraction, contain actin and all of the phosphorylated and nonphosphorylated variants of both desmin and the IFP. Similarly, these proteins are the major components of the caps of aggregated 10-nm filaments isolated from the same cell cultures previously exposed to Colcemid. These results demonstrate that a nonphosphorylated and several phosphorylated variants of desmin and IFP are present in assembled structures in muscle and nonmuscle cells

Suppression of SIV-specific CD4+ T cells by infant but not adult macaque regulatory T cells: implications for SIV disease progression.

The impact of regulatory T cells (T reg cells) on the course of HIV and SIV disease is unknown. T reg cells could suppress protective antiviral responses and accelerate disease progression. Alternatively, these cells might block T cell activation and thereby limit viral replication as well as activation-associated immunopathology. Given the higher frequency of T reg cells known to be present during human fetal ontogeny, such influences may be most important in the context of perinatal infection. We found that infant macaques had higher fractions of CD4(+)CD25(+)CD127(low)FoxP3(+) T reg cells in the peripheral blood and in lymphoid tissues, and that these T reg cells showed greater in vitro suppressive activity on a per cell basis. Infant and adult macaques were infected with SIVmac251 to test the influence of the T reg cell compartment on SIV-specific immune responses. After infection with SIV, most (three out of four) infant macaques had persistently high viral loads, weak and transient SIV-specific CD4(+) and CD8(+) T cell responses, and rapid disease progression. T reg cells in the infant but not in the adult directly suppressed SIV-specific CD4(+) T cell responses, which were detectable only after depletion of T reg cells. In the case of both the infant and the adult macaque, T reg cells were not able to directly suppress SIV-specific CD8(+) T cell responses and had no apparent effect on T cell activation. In aggregate, these observations suggest that the T reg cell compartment of the infant macaque facilitates rapid disease progression, at least in part by incapacitating SIV-specific CD4(+) T cell responses

Critical Temperature and Amplitude Ratios from a Finite-Temperature Renormalization Group

We study \l\f^4 theory using an environmentally friendly finite-temperature renormalization group. We derive flow equations, using a fiducial temperature as flow parameter, develop them perturbatively in an expansion free from ultraviolet and infrared divergences, then integrate them numerically from zero to temperatures above the critical temperature. The critical temperature, at which the mass vanishes, is obtained by integrating the flow equations and is determined as a function of the zero-temperature mass and coupling. We calculate the field expectation value and minimum of the effective potential as functions of temperature and derive some universal amplitude ratios which connect the broken and symmetric phases of the theory. The latter are found to be in good agreement with those of the three-dimensional Ising model obtained from high- and low-temperature series expansions.Comment: 14 pages of LaTeX. Postscript figures available upon request form [email protected]

The Specific Heat of a Ferromagnetic Film.

We analyze the specific heat for the $O(N)$ vector model on a $d$-dimensional film geometry of thickness $L$ using ``environmentally friendly'' renormalization. We consider periodic, Dirichlet and antiperiodic boundary conditions, deriving expressions for the specific heat and an effective specific heat exponent, \alpha\ef. In the case of $d=3$, for $N=1$, by matching to the exact exponent of the two dimensional Ising model we capture the crossover for \xi_L\ra\infty between power law behaviour in the limit {L\over\xi_L}\ra\infty and logarithmic behaviour in the limit {L\over\xi_L}\ra0 for fixed $L$, where $\xi_L$ is the correlation length in the transverse dimensions.Comment: 21 pages of Plain TeX. Postscript figures available upon request from [email protected]