Optimal Compression of Floating-point Astronomical Images Without Significant Loss of Information

We describe a compression method for floating-point astronomical images that gives compression ratios of 6 -- 10 while still preserving the scientifically important information in the image. The pixel values are first preprocessed by quantizing them into scaled integer intensity levels, which removes some of the uncompressible noise in the image. The integers are then losslessly compressed using the fast and efficient Rice algorithm and stored in a portable FITS format file. Quantizing an image more coarsely gives greater image compression, but it also increases the noise and degrades the precision of the photometric and astrometric measurements in the quantized image. Dithering the pixel values during the quantization process can greatly improve the precision of measurements in the images. This is especially important if the analysis algorithm relies on the mode or the median which would be similarly quantized if the pixel values are not dithered. We perform a series of experiments on both synthetic and real astronomical CCD images to quantitatively demonstrate that the magnitudes and positions of stars in the quantized images can be measured with the predicted amount of precision. In order to encourage wider use of these image compression methods, we have made available a pair of general-purpose image compression programs, called fpack and funpack, which can be used to compress any FITS format image.Comment: Accepted PAS

Lossless Astronomical Image Compression and the Effects of Noise

We compare a variety of lossless image compression methods on a large sample of astronomical images and show how the compression ratios and speeds of the algorithms are affected by the amount of noise in the images. In the ideal case where the image pixel values have a random Gaussian distribution, the equivalent number of uncompressible noise bits per pixel is given by Nbits =log2(sigma * sqrt(12)) and the lossless compression ratio is given by R = BITPIX / Nbits + K where BITPIX is the bit length of the pixel values and K is a measure of the efficiency of the compression algorithm. We perform image compression tests on a large sample of integer astronomical CCD images using the GZIP compression program and using a newer FITS tiled-image compression method that currently supports 4 compression algorithms: Rice, Hcompress, PLIO, and GZIP. Overall, the Rice compression algorithm strikes the best balance of compression and computational efficiency; it is 2--3 times faster and produces about 1.4 times greater compression than GZIP. The Rice algorithm produces 75%--90% (depending on the amount of noise in the image) as much compression as an ideal algorithm with K = 0. The image compression and uncompression utility programs used in this study (called fpack and funpack) are publicly available from the HEASARC web site. A simple command-line interface may be used to compress or uncompress any FITS image file.Comment: 20 pages, 9 figures, to be published in PAS

Letter from Vice President Pence to House Speaker Nancy Pelosi Regarding the 25th Amendment

Letter from Vice President Michael R. Pence to Speaker of the House of Representatives Nancy Pelosi responding to approval by the House of a resolution calling on the Vice President to convene and mobilize the principal officers of the executive departments of the Cabinet to activate Section 4 of the 25th Amendment to declare President Donald J. Trump incapable of executing the duties of his office and to immediately exercise powers as acting President. The resolution was introduced in response to the January 6, 2021, attack on the United States Capitol.https://ir.lawnet.fordham.edu/twentyfifth_amendment_executive_materials/1012/thumbnail.jp

General Anesthesia and The Importance of Smoking Cessation

Despite the known consequences of cigarette smoking, one third of the population of industrialized countries continue to smoke (Rodrigo, 2000). Cigarette smoking alters nonnal physiologic function of the cardiac and respiratory systems and increases risks in the perioperative period for general anesthesia. Systematic reviews and randomized controlled trials have reached the following conclusion: smokers who stop smoking four to eight weeks prior to a scheduled surgery are less likely to develop complications post operatively. Eight weeks of smoking cessation prior to anesthesia is considered to be optimal. Smokers have been noted to possibly need increased analgesia, sedatives, and non-depolarizing muscle relaxants (Webb et al., 2013 ). Patients that present for a scheduled surgical procedure require education on the importance of smoking cessation eight weeks before the procedure in order to achieve and sustain success. The information addressed should include decreased perioperative complications, improved pain control, and wound healing. Verbal education and support have been identified as the preferred teaching methods for patients (Webb et al.). Because CRNAs will continue to encounter patients that smoke, it is important to understand the changes this group of patients goes thoug

Physical Quality of South Dakota Wheat

The producer selling wheat to the country elevator or shipper does so on the basis of physical quality of the grain. Increased wheat production throughout the world has stiffened competition in the wheat market and all wheat producers are realizing the need for keeping a closer watch on quality. A study of the physical quality of hard red winter and hard red spring wheat in South Dakota began in 1963. Each summer for 5 years, samples were taken from trucks at country elevators to ascertain the quality of wheat being delivered by South Dakota producers. The samples were studied and graded according to the Official Grain Grading Standards of the United States Department of Agriculture

School-based extracurricular activity participation of secondary students with severe disabilities

The purpose of this qualitative study was to examine the participation of secondary students with severe disabilities in extracurricular school clubs. Specifically, this study sought to understand: (a) the motivating factors that affected the inclusion of students with severe disabilities in school clubs, and (b) how students participated in school club activities. Using a multiple case study, the experiences of three high school students participating in school clubs were documented. Data were collected through interviews with special education teachers, club sponsors, and parents; observations of students participating in school club activities; and document reviews of school club information sources as well as Individualized Education Programs. Data analysis entailed coding interviews, observations, and document reviews for categories. A second level of analysis included a cross-case thematic evaluation of all data sources. Participating in fun activities with peers was the primary motivating factor for why students joined school clubs, while adult encouragement and being a part of a group were motivational factors affecting students’ continued involvement in school club activities. In general, students participated differently than their peers in school club activities. Students also received various amounts of personal support during their participation in school club activities, and were rarely supervised or monitored by an adult

ROSAT implementation of a proposed multi-mission x ray data format

Until recently little effort has been made to ensure that data from X-ray telescopes are delivered in a format that reflects the common characteristics that most X-ray datasets share. Instrument-specific data-product design hampers the comparison of X-ray measurements made by different detectors and should be avoided whenever possible. The ROSAT project and the High Energy Astrophysics Science Archive Research Center (HEASARC) have defined a set of X-ray data products ('rationalized files') for ROSAT data that can be used for distribution and archiving of data from other X-ray missions. This set of 'rationalized files' has been defined to isolate instrument-independent and instrument-specific quantities using standards FITS constructs to ensure portability. We discuss the usage of the 'rationalized files' by ROSAT for data distribution and archiving, with particular emphasis on discrimination between instrument-independent and instrument-specific quantities, and discuss application of this format to data from other X-ray missions

The Future is Hera! Analyzing Astronomical Over the Internet

Hera is the data processing facility provided by the High Energy Astrophysics Science Archive Research Center (HEASARC) at the NASA Goddard Space Flight Center for analyzing astronomical data. Hera provides all the pre-installed software packages, local disk space, and computing resources need to do general processing of FITS format data files residing on the users local computer, and to do research using the publicly available data from the High ENergy Astrophysics Division. Qualified students, educators and researchers may freely use the Hera services over the internet of research and educational purposes

DDR2 controls breast tumor stiffness and metastasis by regulating integrin mediated mechanotransduction in CAFs

Biomechanical changes in the tumor microenvironment influence tumor progression and metastases. Collagen content and fiber organization within the tumor stroma are major contributors to biomechanical changes (e., tumor stiffness) and correlated with tumor aggressiveness and outcome. What signals and in what cells control collagen organization within the tumors, and how, is not fully understood. We show in mouse breast tumors that the action of the collagen receptor DDR2 in CAFs controls tumor stiffness by reorganizing collagen fibers specifically at the tumor-stromal boundary. These changes were associated with lung metastases. The action of DDR2 in mouse and human CAFs, and tumors in vivo, was found to influence mechanotransduction by controlling full collagen-binding integrin activation via Rap1-mediated Talin1 and Kindlin2 recruitment. The action of DDR2 in tumor CAFs is thus critical for remodeling collagen fibers at the tumor-stromal boundary to generate a physically permissive tumor microenvironment for tumor cell invasion and metastases