ICESat Observations of Seasonal and Interannual Variations of Sea-Ice Freeboard and Estimated Thickness in the Weddell Sea, Antarctica (2003-2009)

Sea-ice freeboard heights for 17 ICESat campaign periods from 2003 to 2009 are derived from ICESat data. Freeboard is combined with snow depth from Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) data and nominal densities of snow, water and sea ice, to estimate sea-ice thickness. Sea-ice freeboard and thickness distributions show clear seasonal variations that reflect the yearly cycle of growth and decay of the Weddell Sea (Antarctica) pack ice. During October-November, sea ice grows to its seasonal maximum both in area and thickness; the mean freeboards are 0.33-0.41 m and the mean thicknesses are 2.10-2.59 m. During February-March, thinner sea ice melts away and the sea-ice pack is mainly distributed in the west Weddell Sea; the mean freeboards are 0.35-0.46 m and the mean thicknesses are 1.48-1.94 m. During May-June, the mean freeboards and thicknesses are 0.26-0.29 m and 1.32-1.37 m, respectively. The 6 year trends in sea-ice extent and volume are (0.023+/-0.051) x 10(exp 6)sq km/a (0.45%/a) and (0.007+/-1.0.092) x 10(exp 3)cu km/a (0.08%/a); however, the large standard deviations indicate that these positive trends are not statistically significant

Giardia Cyst Wall Protein 1 Is a Lectin That Binds to Curled Fibrils of the GalNAc Homopolymer

The infectious and diagnostic stage of Giardia lamblia (also known as G. intestinalis or G. duodenalis) is the cyst. The Giardia cyst wall contains fibrils of a unique β-1,3-linked N-acetylgalactosamine (GalNAc) homopolymer and at least three cyst wall proteins (CWPs) composed of Leu-rich repeats (CWPLRR) and a C-terminal conserved Cys-rich region (CWPCRR). Our goals were to dissect the structure of the cyst wall and determine how it is disrupted during excystation. The intact Giardia cyst wall is thin (~400 nm), easily fractured by sonication, and impermeable to small molecules. Curled fibrils of the GalNAc homopolymer are restricted to a narrow plane and are coated with linear arrays of oval-shaped protein complex. In contrast, cyst walls of Giardia treated with hot alkali to deproteinate fibrils of the GalNAc homopolymer are thick (~1.2 µm), resistant to sonication, and permeable. The deproteinated GalNAc homopolymer, which forms a loose lattice of curled fibrils, is bound by native CWP1 and CWP2, as well as by maltose-binding protein (MBP)-fusions containing the full-length CWP1 or CWP1LRR. In contrast, neither MBP alone nor MBP fused to CWP1CRR bind to the GalNAc homopolymer. Recombinant CWP1 binds to the GalNAc homopolymer within secretory vesicles of Giardia encysting in vitro. Fibrils of the GalNAc homopolymer are exposed during excystation or by treatment of heat-killed cysts with chymotrypsin, while deproteinated fibrils of the GalNAc homopolymer are degraded by extracts of Giardia cysts but not trophozoites. These results show the Leu-rich repeat domain of CWP1 is a lectin that binds to curled fibrils of the GalNAc homopolymer. During excystation, host and Giardia proteases appear to degrade bound CWPs, exposing fibrils of the GalNAc homopolymer that are digested by a stage-specific glycohydrolase. Author SummaryWhile the walls of plants and fungi contain numerous sugar homopolymers (cellulose, chitin, and β-1,3-glucans) and dozens of proteins, the cyst wall of Giardia is relatively simple. The Giardia wall contains a unique homopolymer of β-1,3-linked N-acetylgalactosamine (GalNAc) and at least three cyst wall proteins (CWPs), each of which is composed of Leu-rich repeats and a C-terminal Cys-rich region. The three major discoveries here are: 1) Fibrils of the GalNAc homopolymer are curled and form a lattice that is compressed into a narrow plane by bound protein in intact cyst walls. 2) Leu-rich repeats of CWP1 form a novel lectin domain that is specific for fibrils of the GalNAc homopolymer, which can be isolated by methods used to deproteinate fungal walls. 3) A cyst-specific glycohydrolase is able to degrade deproteinated fibrils of the GalNAc homopolymer. We incorporate these findings into a new curled fiber and lectin model of the intact Giardia cyst wall and a protease and glycohydrolase model of excystation.National Institutes of Health (AI048082, AI44070, GM31318, RR1088

Forage crops for swine

The imperative need of green pastures in pork production is emphasized in the results of 3 years’ investigations at the Iowa Agricultural Experiment Station. They show that the profits on forage fed spring pigs can be increased more than five fold over those fed in dry lot. Alfalfa grazed pigs in 1911 returned a profit of more than $3.00 each as compared to 61 cents in dry lot. Profits of from$30.00 to $80.00 an acre, counting corn at 50 cents and hogs at$5.00, have been easily secured with our good forages. An acre of alfalfa in 1911 netted on this basis $65.99; red clover in 1909,$32.34, in 1910, $34.62; rape in 1909,$27.50 and $27.72; in 1910,$37.51, and in 1911, $80.37; sweet clover in 1910,$42.07, 1911, $23.46; a mixture of oats, clover and rape in 1909,$32.30; a mixture of oats, Canadian field peas and rape in 1909, $22.83; in 1911,$39.52, $53.45 and$64.63; and blue grass and timothy in 1909, $15.23

Forage crops for hogs

When it is understood that the profits on forage fed spring pigs can be increased more than five fold over those fed in dry lot, the great value of green pastures in pork production becomes clear. In 1911, pigs grazed upon alfalfa at the Iowa Agricultural Experiment station returned a profit of more than $3.00 each, as compared to 61 cents in dry lot. The yearly net profits with spring pigs on an acre of forage at Ames, counting corn at 50 cents a bushel and hogs at$5.00, has ranged with the best forages from $30.00 to$80.00. In 1909, an acre of red clover netted on this basis, $32.34; oats, red clover and rape,$32.30; in 1910, sweet clover, $42.07; rape,$37.57; and red clover, $34.62; in 1911, rape,$80.37; alfalfa, $65.99; and oats, field peas and rape,$64.63. Such profits encourage the growing of hog forages. The average daily profit on young pigs grazing in forage is invariably higher than on those confined to pens

Evaluating Small UAS Near Midair Collision Risk Using AeroScope and ADS-B

As small unmanned aircraft systems (sUAS) continue to proliferate in the National Airspace System (NAS), near midair collisions are becoming more common. In late 2017, the National Transportation Safety Board released a report detailing the first confirmed midair collision between a sUAS and manned aircraft in the United States. In February 2018, a video of a sUAS maneuvering around a passenger jetliner on approach to a Las Vegas airport went viral on YouTube. Just months later, a helicopter instructor pilot reported performing evasive maneuvers to avoid colliding with a sUAS, resulting in a non-fatal crash. From 2014 to 2018 the Federal Aviation Administration (FAA) recorded 6,117 reports of near encounters between manned and unmanned aircraft within the NAS (Government Accountability Office [GAO], 2018). In their report, the GAO (2018) highlighted the need for additional operational data to aid the FAA’s management of safety risks posed by unmanned aircraft. The purpose of this study was to evaluate aviation interference and safety hazards caused by unmanned aircraft at an airport in Class C airspace. Using a passive RF sUAS detection device known as the AeroScope, the authors collected sUAS operations data for 13 days at Daytona Beach International Airport in Florida. While the study was limited to DJI-manufactured sUAS, the results yielded detailed operational information on 190 sUAS flights that had been conducted during the sampling period. The authors identified several operator behaviors including preferred sUAS models, flight days and times, common operating locations, and operational altitudes. Operational data was compared against published FAA UAS Facility Maps (UASFM) to examine potential risk areas. Additionally, sUAS detections were compared against historical ADS-B information to examine for potential midair collisions, yielding several notable case studies. The authors evaluated the effectiveness of existing geofencing infrastructure and provided recommendations for integration with the Low Altitude Authorization and Notification Capability (LAANC) system. The paper culminates with a proposal for integrating LAANC usage data into existing aviation information sharing infrastructure to improve manned pilot situational awareness of sUAS activity within the NAS

The Ursinus Weekly, October 28, 1963

69 women pledge sororities at bid signing Saturday • Class of 1966 to sell slaves at Bazaar • Annual Founders Day November 3; Five honorary degrees to be awarded • Navy debate team bows UC 31-29 • Young Democrats begin activities • Halloween reading night October 30 • Indians warpath at Jr. turnabout • Pre-med society hears Dr. French • Biggest bargain of the year: 1964 Ruby sales begin • $8500 scholarships available for Univ. of Hawaii • Editorial: Which way out?; Action, please • Letters to the editor • Conservatism reconsidered: Spencer\u27s article decried • Human understanding theme of presentation • Fundamental need unfilled • Penna. seeks librarians • Groups schedule career conf. • Federal service exam November 23 • Greek gleanings • Kaffee klatsch: Foreign students reception • Bears topple Swarthmore on fine team effort, 14-6 • Player of the week • Soccer team bows twice • Hockey team still undefeatedhttps://digitalcommons.ursinus.edu/weekly/1255/thumbnail.jp

Book Reviews

Professor Husband\u27s book deals with two problems, the date of the trial and crucifixion of Jesus, and the legal aspects of the proceedings against him. In both divisions of the subject his conclusions are novel and are supported by able argumentation

Measurement in Economics and Social Science

The paper discusses measurement, primarily in economics, from both analytical and historical perspectives. The historical section traces the commitment to ordinalism on the part of economic theorists from the doctrinal disputes between classical economics and marginalism, through the struggle of orthodox economics against socialism down to the cold-war alliance between mathematical social science and anti-communist ideology. In economics the commitment to ordinalism led to the separation of theory from the quantitative measures that are computed in practice: price and quantity indexes, consumer surplus and real national product. The commitment to ordinality entered political science, via Arrow’s ‘impossibility theorem’, effectively merging it with economics, and ensuring its sterility. How can a field that has as its central result the impossibility of democracy contribute to the design of democratic institutions? The analytical part of the paper deals with the quantitative measures mentioned above. I begin with the conceptual clarification that what these measures try to achieve is a restoration of the money metric that is lost when prices are variable. I conclude that there is only one measure that can be embedded in a satisfactory economic theory, free from unreasonable restrictions. It is the Törnqvist index as an approximation to its theoretical counterpart the Divisia index. The statistical agencies have at various times produced different measures for real national product and its components, as well as related concepts. I argue that all of these are flawed and that a single deflator should be used for the aggregate and the components. Ideally this should be a chained Törnqvist price index defined on aggregate consumption. The social sciences are split. The economic approach is abstract, focused on the assumption of rational and informed behavior, and tends to the political right. The sociological approach is empirical, stresses the non-rational aspects of human behavior and tends to the political left. I argue that the split is due to the fact that the empirical and theoretical traditions were never joined in the social sciences as they were in the natural sciences. I also argue that measurement can potentially help in healing this split

Antarctic Ice-Shelf Front Dynamics from ICESat

Time variable elevation profiles from ICESat Laser Altimetry over the period 2003-2009 provide a means to quantitatively detect and track topographic features on polar ice surfaces. The results of this study provide a measure of the horizontal motion of ice-shelf fronts. We examine the time histories of elevation profiles crossing the ice fronts of the Ross, Ronne, Filchner, Riiser-Larson and Fimbul shelves. This provides a basis for estimating dynamics in two dimensions, i.e. in elevation and horizontally in the along-track direction. Ice front velocities, corrected for ground-track intersection angle, range from nearly static to 1.1 km/yr. In many examples, a decrease in elevation up to 1 m/yr near the shelf frontis also detectable. Examples of tabular calving along shelf fronts are seen in some elevation profiles and are confirmed by corresponding MODIS imagery