On the nucleotide distribution in bacterial DNA sequences

It is probable that the distributional structure of DNA sequences arises from the accumulation of many successive stochastic events such as nucleotide deletions, insertions, substitutions and elongations [1, 2, 3, 4, 5, 6, 7]. Although the existence of long-range correlations in non-coding portions of DNA sequences is well established [8, 9, 10, 11], first order Markov chains might well capture aspects of their nucleotide distributions [12]. Here we propose a hidden Markov model based on a coupling of an urn process with a Markov chain to approximate the distributional structure of primitive DNA sequences. Then, by supposing that a bacterial DNA sequence can be derived from uniformly distributed mutations of some primitive DNA, we use the model to explain and predict some distributional properties of bacterial DNA sequences. The distributional properties intrinsic to the model were compared to statistical estimates from 1049 bacterial DNA sequences. In particular, the proposed model provides another possible theoretical explanation for Chargaff’s second parity rule for short oligonucleotides [13, 14]

MapSnapper: Engineering an Efficient Algorithm for Matching Images of Maps from Mobile Phones

The MapSnapper project aimed to develop a system for robust matching of low-quality images of a paper map taken from a mobile phone against a high quality digital raster representation of the same map. The paper presents a novel methodology for performing content-based image retrieval and object recognition from query images that have been degraded by noise and subjected to transformations through the imaging system. In addition the paper also provides an insight into the evaluation-driven development process that was used to incrementally improve the matching performance until the design specifications were met

In the mind\u27s eye : a study of Shakespeare\u27s imaginative use of stage properties in six representative plays

The unity, or stylistic oneness, that is the most salient characteristic of Shakespeare\u27s style has been achieved with such consummate ease that the underlying pattern of workmanship is imperceptible at a casual reading. Upon analysis, however, the ingenious means which the playwright has employed, perhaps unconsciously, to create this effect of unity easily may be discerned. This paper is an analysis of the stage properties in six plays and their function in the plays\u27 overall design. In this study it may be seen that within each play each stage property is so imaginatively used that it seems at once both natural and wonderful. Each property, upon careful examination yields moreover a striking significance not only to the individual play, but also to the reality-illusion motif which is the implicit theme of the entire canon

Experimental determination of Pb partitioning between sulfide melt and basalt melt as a function of P, T and X

© The Author(s), 2016. This is the author's version of the work and is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Geochimica et Cosmochimica Acta 185 (2016): 9-20, doi:10.1016/j.gca.2016.01.030.We have measured the partition coefficient of Pb (KdPb) between FeS melt and basalt melt at temperatures of 1250–1523 °C, pressures of 1.0–3.5 GPa and oxygen fugacities at iron–wustite and wustite–magnetite. The total observed range of KdPb is 4.0–66.6, with a strong negative dependence on pressure and a strong negative dependence on FeO of the silicate melt (Fe+2 only). The FeO control was constrained over a wide range of FeO (4.2–39.5%). We found that the effect of oxygen fugacity can be subsumed under the FeO control parameter. Prior work has established the lack of a significant effect of temperature (Kiseeva and Wood, 2015; Li and Audétat, 2015). Our data are parameterized as: KdPb = 4.8 + (512 − 119*P in GPa)*(1/FeO − 0.021). We also measured a single value of KdPb between clinopyroxene and basalt melt at 2.0 GPa of 0.020 ± 0.001. This experimental data supports the “natural” partitioning of Pb measured on sulfide globules in MORB (Patten et al., 2013), but not the low KdPb of ∼3 inferred from sulfides in abyssal peridotites by Warren and Shirey (2012). It also quantitatively affirms the modeling of Hart and Gaetani (2006) with respect to using sulfide to buffer the canonical Nd/Pb ratio for MORB and OIB (Hofmann, 2003). For the low FeO and pressure of segregation typical of MORB, KdPb ∼ 45, and the Nd/Pb ratio of erupted basalts will be the same as the Nd/Pb ratio of the mantle source. The remaining puzzle is why MORB and OIB have the same Nd/Pb when they clearly have different FeO and pressure of melt segregation.This work would not have been done without the support of NSF, through Grant EAR-0635530.2017-02-1

Ensemble Concerts: Music for the Holidays: Jazz Combo I; Student Brass Quintet; Symphony Orchestra and Philharmonia Strings; December 2, 2023

Center for the Performing ArtsDecember 2, 2023Saturday Evening7:00 p.m

Modern Poultry Housing

A MODERN POULTRY HOUSE is an asset to a farm. It need not be expensive to give good results. Often some building already on the farm can be remodeled inexpensively to serve the needs of hens. Where old buildings are not available, new housing should be considered. Remodeling or building new poultry housing is a very important job. In order to invest money wisely, careful attention should be given to planning, choice of materials, arrangement of floor plan and use of labor saving devices. A modern, well organized house can do a lot of the chores for the poultry operator. Too often a poultry house is thought of only as a roosting place for the hens. In addition to this it must protect the birds from the hot sun in summer, the cold temperatures in winter and temperature extremes in spring and fall. If properly insulated and ventilated, it will provide a warm, dry place for the hens that will mean good egg production at all times of the year. The purpose of this circular is to discuss the principles of poultry housing and the use of some labor saving devices. Many of these devices can be installed when a house is being built with little additional expense. Plans are available for two types of p oultry houses from the Extension Agricultural Engineer, College Station, South D akota-Extension Circular 504, Modern Poultry Housing Plans for the New South Dakota Laying House ( 24 x 34) for 300 hens and Circular 515 Modern Poultry Housing Plans for the 30 x 50 South Dakota Laying House for 500 hens

Spatial Filter Approach to Evaluating the Role of Convection on the Evolution of a Mesoscale Vortex

A new spatial filter is proposed that exploits a spectral gap in power between the convective scale and the system (‘‘vortex’’) scale during tropical cyclone (TC) genesis simulations. Using this spatial separation, this study analyzes idealized three-dimensional numerical simulations of deep moist convection in the presence of a symmetric midlevel vortex to quantify and understand the energy cascade between the objectively defined convective scale and system scale during the early stages of tropical cyclogenesis. The simulations neglect surface momentum, heat, and moisture fluxes to focus on generation and enhancement of vorticity within the interior to more completely close off the energy budget and to be consistent for comparison with prior benchmark studies of modeled TC genesis. The primary contribution to system-scale intensification comes from the convergence of convective-scale vorticity that is supplied by vortical hot towers (VHTs). They contribute more than the convergence of system-scale vorticity to the spinup of vorticity in these simulations by an order of magnitude. Analysis of the change of circulation with time shows an initial strengthening of the surface vortex, closely followed by a growth of the mid- to upper-level circulation. This evolution precludes any possibility of a stratiform precipitation–induced top-down mechanism as the primary contributor to system-scale spinup in this simulation. Instead, an upscale cascade of rotational kinetic energy during vortex mergers is responsible for spinup of the simulated mesoscale vortex. The spatial filter employed herein offers an alternative approach to the traditional symmetry–asymmetry paradigm, acknowledges the highly asymmetric evolution of the systemscale vortex itself, and may prove useful to future studies on TC genesis

Wellness Domains for Residency Training Programs

In this editorial, we describe a residency-specific wellness framework that residency leadership can utilize in developing their local wellness programs

Design to Delivery of Additively Manufactured Propulsion Systems for the SWARM-EX Mission

Recent progress in miniaturized spacecraft propulsion technology has allowed for the development of complex, multi-vehicle missions which enable the cost-effective realization of science goals that would previously have been prohibitively expensive. The upcoming NSF-funded Space Weather Atmospheric Reconfigurable Multiscale EXperiment (SWARM-EX) mission leverages these swarm techniques to demonstrate novel autonomous formation flying capabilities while characterizing the spatial and temporal variability of ion-neutral interactions in the Equatorial Ionization Anomaly and Equatorial Thermospheric Anomaly. SWARM-EX will fly a trio of 3U CubeSats in a variety of relative orbits with along-track separations ranging from 3 km to 1300 km. To achieve the required orbital variability, the mission uses a novel hybrid approach of differential drag and an onboard cold gas propulsion system. Mission requirements necessitate a propulsion system that provides each spacecraft with 15 m/s of ∆V and a maximum thrust greater than 5 mN in a volume of roughly 0.7U (7 cm x 10 cm x 10 cm). Unlike many other CubeSat-scale cold gas propulsion systems which are used to provide attitude control and perform reaction wheel desaturation burns, the primary objective of the SWARM-EX propulsion system (SEPS) is to provide ∆V during maneuvers. The Georgia Institute of Technology Space Systems Design Laboratory (SSDL) is conducting the design, assembly, and testing of three identical SEPS. By leveraging additive manufacturing technology, the propellant tanks, nozzle, and tubing are combined into a single structure that efficiently utilizes the allocated volume. The propulsion system uses two-phase R-236fa refrigerant as a propellant, which allows for the storage of the majority of propellant mass as a liquid to maximize volumetric efficiency. The final design allows for 17 m/s of total ∆V per spacecraft and a measured maximum thrust of approximately 35 mN for short pulse lengths at room temperature. Each individual propulsion system has a volume under 0.5U (489 cm3), making them among the smallest formation-flying CubeSat-scale propulsion systems developed thus far. Owing to their two-phase propellant storage and single nozzle, the SEPS have a high impulse density (total impulse provided per unit of system volume) of 176 N-s/L. Additionally, process improvements to mitigate known failure modes such as propellant leaks and foreign object debris are implemented. This paper describes the entire design-to-delivery life cycle of the SWARM-EX propulsion units, including pertinent mission requirements, propulsion system design methodologies, assembly, and testing. Major lessons learned for future small satellite propulsive endeavors are also detailed