The Anatomy Puzzle Book.

ERIC Educational Resources Information Center

Jacob, Willis H.; Carter, Robert, III

This document features review questions, crossword puzzles, and word search puzzles on human anatomy. Topics include: (1) Anatomical Terminology; (2) The Skeletal System and Joints; (3) The Muscular System; (4) The Nervous System; (5) The Eye and Ear; (6) The Circulatory System and Blood; (7) The Respiratory System; (8) The Urinary System; (9) The…

Tangrams: Puzzles of Art

ERIC Educational Resources Information Center

Fee, Brenda

2009-01-01

Challenging one's brain is the beginning of making great art. Tangrams are a great way to keep students thinking about their latest art project long after leaving the classroom. A tangram is a Chinese puzzle. The earliest known reference to tangrams appears in a Chinese book dated 1813, but the puzzles existed long before that date. The puzzle…

Musings on the puzzle piece.

PubMed

Goin-Kochel, Robin P

2016-02-01

Following is a brief musing on Roy Grinker's discussion of what the puzzle piece symbolizes for autism during his presentation at the 2015 International Meeting for Autism Research. In his words, "The puzzle piece is ubiquitous." It likely holds a different meaning for each of us, and this is how one autism researcher sees it. © The Author(s) 2015.

Satisfiability modulo theory and binary puzzle

NASA Astrophysics Data System (ADS)

Utomo, Putranto

2017-06-01

The binary puzzle is a sudoku-like puzzle with values in each cell taken from the set {0, 1}. We look at the mathematical theory behind it. A solved binary puzzle is an n × n binary array where n is even that satisfies the following conditions: (1) No three consecutive ones and no three consecutive zeros in each row and each column, (2) Every row and column is balanced, that is the number of ones and zeros must be equal in each row and in each column, (3) Every two rows and every two columns must be distinct. The binary puzzle had been proven to be an NP-complete problem [5]. Research concerning the satisfiability of formulas with respect to some background theory is called satisfiability modulo theory (SMT). An SMT solver is an extension of a satisfiability (SAT) solver. The notion of SMT can be used for solving various problem in mathematics and industries such as formula verification and operation research [1, 7]. In this paper we apply SMT to solve binary puzzles. In addition, we do an experiment in solving different sizes and different number of blanks. We also made comparison with two other approaches, namely by a SAT solver and exhaustive search.

PSQP: Puzzle Solving by Quadratic Programming.

PubMed

Andalo, Fernanda A; Taubin, Gabriel; Goldenstein, Siome

2017-02-01

In this article we present the first effective method based on global optimization for the reconstruction of image puzzles comprising rectangle pieces-Puzzle Solving by Quadratic Programming (PSQP). The proposed novel mathematical formulation reduces the problem to the maximization of a constrained quadratic function, which is solved via a gradient ascent approach. The proposed method is deterministic and can deal with arbitrary identical rectangular pieces. We provide experimental results showing its effectiveness when compared to state-of-the-art approaches. Although the method was developed to solve image puzzles, we also show how to apply it to the reconstruction of simulated strip-shredded documents, broadening its applicability.

A puzzle used to teach the cardiac cycle.

PubMed

Marcondes, Fernanda K; Moura, Maria J C S; Sanches, Andrea; Costa, Rafaela; de Lima, Patricia Oliveira; Groppo, Francisco Carlos; Amaral, Maria E C; Zeni, Paula; Gaviao, Kelly Cristina; Montrezor, Luís H

2015-03-01

The aim of the present article is to describe a puzzle developed for use in teaching cardiac physiology classes. The puzzle presents figures of phases of the cardiac cycle and a table with five columns: phases of cardiac cycle, atrial state, ventricular state, state of atrioventricular valves, and pulmonary and aortic valves. Chips are provided for use to complete the table. Students are requested to discuss which is the correct sequence of figures indicating the phases of cardiac cycle. Afterward, they should complete the table with the chips. Students of biology, dentistry, medicine, pharmacy, and nursing graduation courses from seven institutions performed the puzzle evaluation. They were invited to indicate whether the puzzle had been useful for learning about the subject by filling one of four alternatives. Of the students, 4.6% answered that it was not necessary but helped them to confirm what they had learned, 64.5% reported that although they had previously understood the cardiac cycle, the puzzle helped them to solve doubts and promoted a better understanding of it, and 30.9% said that they needed the puzzle to understand the cardiac cycle, without differences among courses, institutions, and course semesters. The results of the present study suggest that a simple and inexpensive puzzle may be useful as an active learning methodology applied after the theoretical lecture, as a complementary tool for studying cardiac cycle physiology. Copyright © 2015 The American Physiological Society.

Chemistry of Art and Color Sudoku Puzzles

ERIC Educational Resources Information Center

Welsh, Michael J.

2007-01-01

Sudoku puzzle format was used to teach light science and chemistry terms to students of Chemistry of Art and Color. The puzzles were used to motivate and encourage students to learn chemistry in an easier and in friendly fashion.

Puzzling practice: a strategy for working with clinical practice issues.

PubMed

Walsh, Kenneth; Moss, Cheryle; Lawless, Jane; McKelvie, Rhonda; Duncan, Lindsay

2008-04-01

In this paper we aim to share the evolution of innovative ways to explore, 'unpack' and reframe clinical issues that exist in everyday practice. The elements of these processes, which we call 'puzzling practice', and the techniques associated with them, were delineated over a two year period by the four authors using action theory based processes. The authors have evolved several different frameworks for 'puzzling practice' which we draw on and use in our practice development work and in our research practice. This paper pays attention to a particular form of puzzling practice that we have found to be useful in assisting individual clinicians and teams to explore and find workable solutions to practice issues. The paper uses a semi-fictitious example of 'Puzzling Practice' gleaned from our experience as practice development facilitators. In this example 'puzzling practice' uses seven different elements; naming the issue; puzzling the issue; testing the puzzle exploring the heart of out practice; formulating the puzzle question; visualizing the future; and generating new strategies for action. Each of the elements is illustrated by the story and the key foundations and ideas behind each element is explored.

Early Puzzle Play: A predictor of preschoolers’ spatial transformation skill

PubMed Central

Levine, S.C.; Ratliff, K.R.; Huttenlocher, J.; Cannon, J.

2011-01-01

Individual differences in spatial skill emerge prior to kindergarten entry. However, little is known about the early experiences that may contribute to these differences. The current study examines the relation between children’s early puzzle play and their spatial skill. Children and parents (n = 53) were observed at home for 90 minutes every four months (six times) between 2 and 4 years of age (26 to 46 months). When children were 4 years 6 months old, they completed a spatial task involving mental transformations of 2D shapes. Children who were observed playing with puzzles performed better on this task than those who did not, controlling for parent education, income, and overall parent word types. Moreover, among those children who played with puzzles, frequency of puzzle play predicted performance on the spatial transformation task. Although the frequency of puzzle play did not differ for boys and girls, the quality of puzzle play (a composite of puzzle difficulty, parent engagement, and parent spatial language) was higher for boys than girls. In addition, variation in puzzle play quality predicted performance on the spatial transformation task for girls but not boys. Implications of these findings as well as future directions for research on the role of the role of puzzle play in the development of spatial skill are discussed. PMID:22040312

Early puzzle play: a predictor of preschoolers' spatial transformation skill.

PubMed

Levine, Susan C; Ratliff, Kristin R; Huttenlocher, Janellen; Cannon, Joanna

2012-03-01

Individual differences in spatial skill emerge prior to kindergarten entry. However, little is known about the early experiences that may contribute to these differences. The current study examined the relation between children's early puzzle play and their spatial skill. Children and parents (n = 53) were observed at home for 90 min every 4 months (6 times) between 2 and 4 years of age (26 to 46 months). When children were 4 years 6 months old, they completed a spatial task involving mental transformations of 2-dimensional shapes. Children who were observed playing with puzzles performed better on this task than those who did not, controlling for parent education, income, and overall parent word types. Moreover, among those children who played with puzzles, frequency of puzzle play predicted performance on the spatial transformation task. Although the frequency of puzzle play did not differ for boys and girls, the quality of puzzle play (a composite of puzzle difficulty, parent engagement, and parent spatial language) was higher for boys than for girls. In addition, variation in puzzle play quality predicted performance on the spatial transformation task for girls but not for boys. Implications of these findings as well as future directions for research on the role of puzzle play in the development of spatial skill are discussed. PsycINFO Database Record (c) 2012 APA, all rights reserved.

Deductive Puzzling

ERIC Educational Resources Information Center

Wanko, Jeffrey J.

2010-01-01

To help fifth- through eighth-grade students develop their deductive reasoning skills, the author used a ten-week supplementary curriculum so that students could answer logic questions. The curriculum, a series of lessons built around language-independent logic puzzles, has been used in classrooms of fifth through eighth grades. In most cases,…

Puzzle Pedagogy: A Use of Riddles in Mathematics Education

ERIC Educational Resources Information Center

Farnell, Elin

2017-01-01

In this article, I present a collection of puzzles appropriate for use in a variety of undergraduate courses, along with suggestions for relevant discussion. Logic puzzles and riddles have long been sources of amusement for mathematicians and the general public alike. I describe the use of puzzles in a classroom setting, and argue for their use as…

Economics - A Puzzle: The People Power Solution.

ERIC Educational Resources Information Center

Bartlett, Glenda; Price, Marlene H.

A third-grade class and fifth-grade remedial reading students gained a positive attitude toward contemporary economic problems by studying economics as a puzzle in this award-winning project. The following concepts were each approached as pieces of the puzzle to be solved: money, wants and needs, income, goods and services, scarcity, consumption…

Solar System Puzzle Kit: An Activity for Earth and Space Science.

ERIC Educational Resources Information Center

Vogt, Gregory L.; Rosenberg, Carla B.

This Solar System Puzzle Kit for grades 5-8, allows students to create an eight-cube paper puzzle of the solar system and may be duplicated for classroom use or used as a take home activity for children and parents. By assembling the puzzle, hand-coloring the bodies of the solar system, and viewing the puzzle's 12 sides, students can reinforce…

Puzzling Ways to Learn

ERIC Educational Resources Information Center

School Shop, 1975

1975-01-01

Four authors present crossword and wordfind puzzles developed for students in the areas of electricity, principles of hydraulics, finishing, construction, thermoplastic materials, patternmaking, wood, occupations, and drafting. (BP)

Algorithmic Puzzles: History, Taxonomies, and Applications in Human Problem Solving

ERIC Educational Resources Information Center

Levitin, Anany

2017-01-01

The paper concerns an important but underappreciated genre of algorithmic puzzles, explaining what these puzzles are, reviewing milestones in their long history, and giving two different ways to classify them. Also covered are major applications of algorithmic puzzles in cognitive science research, with an emphasis on insight problem solving, and…

The B → π K puzzle revisited

NASA Astrophysics Data System (ADS)

Beaudry, Nicolas Boisvert; Datta, Alakabha; London, David; Rashed, Ahmed; Roux, Jean-Samuel

2018-01-01

For a number of years, there has been a certain inconsistency among the measurements of the branching ratios and CP asymmetries of the four B → π K decays ( B + → π+ K 0, B + → π0 K +, B d 0 → π - K +, B d 0 → π 0 K 0). In this paper, we re-examine this B → π K puzzle. We find that the key unknown parameter is | C ' /T '|, the ratio of color-suppressed and color-allowed tree amplitudes. If this ratio is large, | C ' /T '| = 0 .5, the SM can explain the data. But if it is small, | C ' /T '| = 0 .2, the SM cannot explain the B → π K puzzle —new physics (NP) is needed. The two types of NP that can contribute to B → π K at tree level are Z ' bosons and diquarks. Z ' models can explain the puzzle if the Z ' couples to right-handed uū and/or d\\overline{d} , with g R dd ≠ g R uu . Interestingly, half of the many Z ' models proposed to explain the present anomalies in b → sμ + μ - decays have the required Z ' couplings to uū and/or d\\overline{d} . Such models could potentially explain both the b → sμ + μ - anomalies and the B → π K puzzle. The addition of a color sextet diquark that couples to ud can also explain the puzzle.

An Analysis of Instructor-Created Crossword Puzzles for Student Review

ERIC Educational Resources Information Center

Weisskirch, Robert S.

2006-01-01

This article evaluates the use of instructor-created crossword puzzles as a means of reviewing course material. Students completed one crossword puzzle in class to prepare for an exam, and then they had the opportunity to complete a second crossword puzzle outside of class to prepare for the second exam. Students generally rated the crossword…

Puzzles in modern biology. I. Male sterility, failure reveals design

PubMed Central

Frank, Steven A.

2016-01-01

Many human males produce dysfunctional sperm. Various plants frequently abort pollen. Hybrid matings often produce sterile males. Widespread male sterility is puzzling. Natural selection prunes reproductive failure. Puzzling failure implies something that we do not understand about how organisms are designed. Solving the puzzle reveals the hidden processes of design. PMID:28004842

Sudoku Puzzles for First-Year Organic Chemistry Students

ERIC Educational Resources Information Center

Perez, Alice L.; Lamoureux, G.

2007-01-01

Sudoku puzzle was designed to teach about amino acids and functional groups to the students of undergraduate organic chemistry students. The puzzles focus on helping the student learn the name, 3-letter code and 1-letter code of common amino acids and functional groups.

Discovery of a new motion mechanism of biomotors similar to the earth revolving around the sun without rotation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guo, Peixuan, E-mail: peixuan.guo@uky.edu; Schwartz, Chad; Haak, Jeannie

Biomotors have been classified into linear and rotational motors. For 35 years, it has been popularly believed that viral dsDNA-packaging apparatuses are pentameric rotation motors. Recently, a third class of hexameric motor has been found in bacteriophage phi29 that utilizes a mechanism of revolution without rotation, friction, coiling, or torque. This review addresses how packaging motors control dsDNA one-way traffic; how four electropositive layers in the channel interact with the electronegative phosphate backbone to generate four steps in translocating one dsDNA helix; how motors resolve the mismatch between 10.5 bases and 12 connector subunits per cycle of revolution; and howmore » ATP regulates sequential action of motor ATPase. Since motors with all number of subunits can utilize the revolution mechanism, this finding helps resolve puzzles and debates concerning the oligomeric nature of packaging motors in many phage systems. This revolution mechanism helps to solve the undesirable dsDNA supercoiling issue involved in rotation. - Highlights: • New motion mechanism of revolution without rotation found for phi29 DNA packaging. • Revolution motor finding expands classical linear and rotation biomotor classes. • Revolution motors transport dsDNA unidirectionally without supercoiling. • New mechanism solves many puzzles, mysteries, and debates in biomotor studies. • Motors with all numbers of subunits can utilize the revolution mechanism.« less

Teaching the Blue-Eyed Islanders Puzzle in a Liberal Arts Mathematics Course

ERIC Educational Resources Information Center

Shea, Stephen

2012-01-01

The blue-eyed islanders puzzle is an old and challenging logic puzzle. This is a narrative of an experience introducing a variation of this puzzle on the first day of classes in a liberal arts mathematics course for non-majors. I describe an exercise that was used to facilitate the class's understanding of the puzzle.

Model Prediction of Self-Rotating Excitons in Two-Dimensional Transition-Metal Dichalcogenides

NASA Astrophysics Data System (ADS)

Trushin, Maxim; Goerbig, Mark Oliver; Belzig, Wolfgang

2018-05-01

Using the quasiclassical concept of Berry curvature we demonstrate that a Dirac exciton—a pair of Dirac quasiparticles bound by Coulomb interactions—inevitably possesses an intrinsic angular momentum making the exciton effectively self-rotating. The model is applied to excitons in two-dimensional transition metal dichalcogenides, in which the charge carriers are known to be described by a Dirac-like Hamiltonian. We show that the topological self-rotation strongly modifies the exciton spectrum and, as a consequence, resolves the puzzle of the overestimated two-dimensional polarizability employed to fit earlier spectroscopic measurements.

Puzzling Two-Proton Decay of 67Kr

NASA Astrophysics Data System (ADS)

Wang, S. M.; Nazarewicz, W.

2018-05-01

Ground-state two-proton (2 p ) radioactivity is a rare decay mode found in a few very proton-rich isotopes. The 2 p decay lifetime and properties of emitted protons carry invaluable information on nuclear structure in the presence of a low-lying proton continuum. The recently measured 2 p decay of 67Kr turned out to be unexpectedly fast. Since 67Kr is expected to be a deformed system, we investigate the impact of deformation effects on the 2 p radioactivity. We apply the recently developed Gamow coupled-channel framework, which allows for a precise description of three-body systems in the presence of rotational and vibrational couplings. This is the first application of a three-body approach to a two-nucleon decay from a deformed nucleus. We show that deformation couplings significantly increase the 2 p decay width of 67Kr; this finding explains the puzzling experimental data. The calculated angular proton-proton correlations reflect a competition between 1 p and 2 p decay modes in this nucleus.

More Pebble Puzzles.

ERIC Educational Resources Information Center

Gibbs, William M.

This booklet is a collection of puzzles, investigations, and games. They are designed to be used with large objects such as tins or stones and diagrams marked on the ground. The children are to be encouraged to use an experimental, trial-and-error approach at first, and then develop methods of solution. (MNS)

Three Modes of Hydrogeophysical Investigation: Puzzles, Mysteries, and Conundrums

NASA Astrophysics Data System (ADS)

Ferre, P. A.

2011-12-01

In an article in the New Yorker in 2007, Malcolm Gladwell discussed the distinction that national security expert Gregory Treverton has made between puzzles and mysteries. Specifically, puzzles are problems that we understand and that will eventually be solved when we amass enough information. (Think crossword puzzles.) Mysteries are problems for which we have the necessary information, but it is often overwhelmed by irrelevant or misleading input. To solve a mystery, we require improved analysis. (Think find-a-word.) Gladwell goes on to explain that, in the national security realm, the Cold War was a puzzle while the current national security condition is a mystery. I will discuss the past, current, and future trajectories of hydrogeophysics in terms of puzzles and mysteries. I will also add a third class of problem: conundrums - those for which we lack sufficient information about their structure to know how to solve them. A conundrum is a mystery with an unexpected twist. I hope to make the case that the future growth of hydrogeophysics lies in our ability to address this more challenging and more interesting class of problem.

GAMES AND PUZZLES FOR THE MORE ABLE STUDENT.

ERIC Educational Resources Information Center

GOLDSMITH, JOHN

SUCH MATHEMATICAL GAMES AS DOMINOES FOR PRIMARY NUMBER RECOGNITION AND AS MILK BOTTLE TOPS FOR ADDITION AND SUBTRACTION ARE LISTED. A LIST OF SEVERAL MATH PROBLEMS, PUZZLES AND BRAIN TEASERS FOLLOW. QUIET GAMES OF PAPER CUTTING AND CROSS WORD PUZZLES FOR MATH VOCABULARY ARE INCLUDED. THE NEXT SECTION OF GAMES CONCERNS LANGUAGE. THESE INCLUDE…

A Puzzle Used to Teach the Cardiac Cycle

ERIC Educational Resources Information Center

Marcondes, Fernanda K.; Moura, Maria J. C. S.; Sanches, Andrea; Costa, Rafaela; Oliveira de Lima, Patricia; Groppo, Francisco Carlos; Amaral, Maria E. C.; Zeni, Paula; Gaviao, Kelly Cristina; Montrezor, Luís H.

2015-01-01

The aim of the present article is to describe a puzzle developed for use in teaching cardiac physiology classes. The puzzle presents figures of phases of the cardiac cycle and a table with five columns: phases of cardiac cycle, atrial state, ventricular state, state of atrioventricular valves, and pulmonary and aortic valves. Chips are provided…

Decoding Codewords: Statistical Analysis of a Newspaper Puzzle

ERIC Educational Resources Information Center

Meacock, Susan; Meacock, Geoff

2012-01-01

In recent years English newspapers have started featuring a number of puzzles other than the ubiquitous crossword. Many of the puzzles are of Japanese origin such as Sudoku, Kakuro or Hidato. However, one recent one is very English and is called variously Cross-code, Alphapuzzle or some other name. In this article, it will be known as Codeword.…

Making Peer-Assisted Content Distribution Robust to Collusion Using Bandwidth Puzzles

NASA Astrophysics Data System (ADS)

Reiter, Michael K.; Sekar, Vyas; Spensky, Chad; Zhang, Zhenghao

Many peer-assisted content-distribution systems reward a peer based on the amount of data that this peer serves to others. However, validating that a peer did so is, to our knowledge, an open problem; e.g., a group of colluding attackers can earn rewards by claiming to have served content to one another, when they have not. We propose a puzzle mechanism to make contribution-aware peer-assisted content distribution robust to such collusion. Our construction ties solving the puzzle to possession of specific content and, by issuing puzzle challenges simultaneously to all parties claiming to have that content, our mechanism prevents one content-holder from solving many others' puzzles. We prove (in the random oracle model) the security of our scheme, describe our integration of bandwidth puzzles into a media streaming system, and demonstrate the resulting attack resilience via simulations.

Ultra high energy electrons powered by pulsar rotation.

PubMed

Mahajan, Swadesh; Machabeli, George; Osmanov, Zaza; Chkheidze, Nino

2013-01-01

A new mechanism of particle acceleration, driven by the rotational slow down of the Crab pulsar, is explored. The rotation, through the time dependent centrifugal force, can efficiently excite unstable Langmuir waves in the electron-positron (hereafter e(±)) plasma of the star magnetosphere. These waves, then, Landau damp on electrons accelerating them in the process. The net transfer of energy is optimal when the wave growth and the Landau damping times are comparable and are both very short compared to the star rotation time. We show, by detailed calculations, that these are precisely the conditions for the parameters of the Crab pulsar. This highly efficient route for energy transfer allows the electrons in the primary beam to be catapulted to multiple TeV (~ 100 TeV) and even PeV energy domain. It is expected that the proposed mechanism may, unravel the puzzle of the origin of ultra high energy cosmic ray electrons.

Incomplete Puzzle

NASA Technical Reports Server (NTRS)

2006-01-01

15 April 2006 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows a mid-summer view of a portion of the south polar residual cap of Mars. The large, relatively flat-lying, puzzle-like pieces in this scene are mesas composed largely of solid carbon dioxide.

Location near: 85.5oS, 76.8oW Image width: 3 km (1.9 mi) Illumination from: upper left Season: Southern Summer

Crossword Puzzles as Learning Tools in Introductory Soil Science

ERIC Educational Resources Information Center

Barbarick, K. A.

2010-01-01

Students in introductory courses generally respond favorably to novel approaches to learning. To this end, I developed and used three crossword puzzles in spring and fall 2009 semesters in Introductory Soil Science Laboratory at Colorado State University. The first hypothesis was that crossword puzzles would improve introductory soil science…

Rotational displacement skills in rhesus macaques (Macaca mulatta).

PubMed

Hughes, Kelly D; Santos, Laurie R

2012-11-01

Rotational displacement tasks, in which participants must track an object at a hiding location within an array while the array rotates, exhibit a puzzling developmental pattern in humans. Human children take an unusually long time to master this task and tend to solve rotational problems through the use of nongeometric features or landmarks as opposed to other kinds of spatial cues. We investigated whether these developmental characteristics are unique to humans by testing rotational displacement skills in a monkey species, the rhesus macaque (Macaca mulatta), using a looking-time method. Monkeys first saw food hidden in two differently colored boxes within an array. The array was then rotated 180° and the boxes reopened to reveal the food in an expected or unexpected location. Our first two experiments explored the developmental time-course of performance on this rotational displacement task. We found that adult macaques looked longer at the unexpected event, but such performance was not mirrored in younger-aged macaques. In a third study, we systematically varied featural information and visible access to the array to investigate which strategies adult macaques used in solving rotational displacements. Our results show that adult macaques need both sets of information to solve the task. Taken together, these results suggest both similarities and differences in mechanisms by which human and nonhuman primates develop this spatial skill.

Rotational Displacement Skills in Rhesus Macaques (Macaca mulatta)

PubMed Central

Hughes, Kelly D.; Santos, Laurie R.

2016-01-01

Rotational displacement tasks, in which participants must track an object at a hiding location within an array while the array rotates, exhibit a puzzling developmental pattern in humans. Human children take an unusually long time to master this task and tend to solve rotational problems through the use of nongeometric features or landmarks as opposed to other kinds of spatial cues. We investigated whether these developmental characteristics are unique to humans by testing rotational displacement skills in a monkey species, the rhesus macaque (Macaca mulatta), using a looking-time method. Monkeys first saw food hidden in two differently colored boxes within an array. The array was then rotated 180° and the boxes reopened to reveal the food in an expected or unexpected location. Our first two experiments explored the developmental time-course of performance on this rotational displacement task. We found that adult macaques looked longer at the unexpected event, but such performance was not mirrored in younger-aged macaques. In a third study, we systematically varied featural information and visible access to the array to investigate which strategies adult macaques used in solving rotational displacements. Our results show that adult macaques need both sets of information to solve the task. Taken together, these results suggest both similarities and differences in mechanisms by which human and nonhuman primates develop this spatial skill. PMID:22866770

Teaching Proofs and Algorithms in Discrete Mathematics with Online Visual Logic Puzzles

ERIC Educational Resources Information Center

Cigas, John; Hsin, Wen-Jung

2005-01-01

Visual logic puzzles provide a fertile environment for teaching multiple topics in discrete mathematics. Many puzzles can be solved by the repeated application of a small, finite set of strategies. Explicitly reasoning from a strategy to a new puzzle state illustrates theorems, proofs, and logic principles. These provide valuable, concrete…

Puzzling through General Chemistry: A Light-Hearted Approach to Engaging Students with Chemistry Content

ERIC Educational Resources Information Center

Boyd, Susan L.

2007-01-01

Several puzzles are designed to be used by chemistry students as learning tools and teach them basic chemical concepts. The topics of the puzzles are based on the chapters from Chemistry, The Central Science used in general chemistry course and the puzzles are in various forms like crosswords, word searches, number searches, puzzles based on…

The Clock Is Ticking: Library Orientation as Puzzle Room

ERIC Educational Resources Information Center

Reade, Tripp

2017-01-01

Tripp Reade is the school librarian at Cardinal Gibbons High School in Raleigh, North Carolina. This article describes how he redesigned his school's library orientation program after learning about escape rooms and a variant known as puzzle rooms. Puzzle rooms present players with a set of challenges to solve; they require "teamwork,…

Puzzle-Based Learning in Engineering Mathematics: Students' Attitudes

ERIC Educational Resources Information Center

Klymchuk, Sergiy

2017-01-01

The article reports on the results of two case studies on the impact of the regular use of puzzles as a pedagogical strategy in the teaching and learning of engineering mathematics. The intention of using puzzles is to engage students' emotions, creativity and curiosity and also to enhance their generic thinking skills and lateral thinking…

International trade network: fractal properties and globalization puzzle.

PubMed

Karpiarz, Mariusz; Fronczak, Piotr; Fronczak, Agata

2014-12-12

Globalization is one of the central concepts of our age. The common perception of the process is that, due to declining communication and transport costs, distance becomes less and less important. However, the distance coefficient in the gravity model of trade, which grows in time, indicates that the role of distance increases rather than decreases. This, in essence, captures the notion of the globalization puzzle. Here, we show that the fractality of the international trade system (ITS) provides a simple solution for the puzzle. We argue that the distance coefficient corresponds to the fractal dimension of ITS. We provide two independent methods, the box counting method and spatial choice model, which confirm this statement. Our results allow us to conclude that the previous approaches to solving the puzzle misinterpreted the meaning of the distance coefficient in the gravity model of trade.

International Trade Network: Fractal Properties and Globalization Puzzle

NASA Astrophysics Data System (ADS)

Karpiarz, Mariusz; Fronczak, Piotr; Fronczak, Agata

2014-12-01

Globalization is one of the central concepts of our age. The common perception of the process is that, due to declining communication and transport costs, distance becomes less and less important. However, the distance coefficient in the gravity model of trade, which grows in time, indicates that the role of distance increases rather than decreases. This, in essence, captures the notion of the globalization puzzle. Here, we show that the fractality of the international trade system (ITS) provides a simple solution for the puzzle. We argue that the distance coefficient corresponds to the fractal dimension of ITS. We provide two independent methods, the box counting method and spatial choice model, which confirm this statement. Our results allow us to conclude that the previous approaches to solving the puzzle misinterpreted the meaning of the distance coefficient in the gravity model of trade.

Visual Puzzles, Figure Weights, and Cancellation: Some Preliminary Hypotheses on the Functional and Neural Substrates of These Three New WAIS-IV Subtests

PubMed Central

McCrea, Simon M.; Robinson, Thomas P.

2011-01-01

In this study, five consecutive patients with focal strokes and/or cortical excisions were examined with the Wechsler Adult Intelligence Scale and Wechsler Memory Scale—Fourth Editions along with a comprehensive battery of other neuropsychological tasks. All five of the lesions were large and typically involved frontal, temporal, and/or parietal lobes and were lateralized to one hemisphere. The clinical case method was used to determine the cognitive neuropsychological correlates of mental rotation (Visual Puzzles), Piagetian balance beam (Figure Weights), and visual search (Cancellation) tasks. The pattern of results on Visual Puzzles and Figure Weights suggested that both subtests involve predominately right frontoparietal networks involved in visual working memory. It appeared that Visual Puzzles could also critically rely on the integrity of the left temporoparietal junction. The left temporoparietal junction could be involved in temporal ordering and integration of local elements into a nonverbal gestalt. In contrast, the Figure Weights task appears to critically involve the right temporoparietal junction involved in numerical magnitude estimation. Cancellation was sensitive to left frontotemporal lesions and not right posterior parietal lesions typical of other visual search tasks. In addition, the Cancellation subtest was sensitive to verbal search strategies and perhaps object-based attention demands, thereby constituting a unique task in comparison with previous visual search tasks. PMID:22389807

Accelerating Student Learning of Technology Terms: "The Crossword Puzzle Exercise"

ERIC Educational Resources Information Center

Whisenand, Thomas G.; Dunphy, Steven M.

2010-01-01

The authors suggest using an alternative teaching methodology to impart knowledge regarding information systems phraseology and vocabulary. Specifically, a series of crossword puzzles or scrabbles are used to present information system (IS) terminology to students in an introductory business information systems course. The puzzle terms and answers…

Enumerating Small Sudoku Puzzles in a First Abstract Algebra Course

ERIC Educational Resources Information Center

Lorch, Crystal; Lorch, John

2008-01-01

Two methods are presented for counting small "essentially different" sudoku puzzles using elementary group theory: one method (due to Jarvis and Russell) uses Burnside's counting formula, while the other employs an invariant property of sudoku puzzles. Ideas are included for incorporating this material into an introductory abstract algebra course.…

Association of Crossword Puzzle Participation with Memory Decline in Persons Who Develop Dementia

PubMed Central

Pillai, Jagan A.; Hall, Charles B.; Dickson, Dennis W.; Buschke, Herman; Lipton, Richard B.; Verghese, Joe

2013-01-01

Participation in cognitively stimulating leisure activities such as crossword puzzles may delay onset of the memory decline in the preclinical stages of dementia, possibly via its effect on improving cognitive reserve. We followed 488 initially cognitively intact community residing individuals with clinical and cognitive assessments every 12–18 months in the Bronx Aging Study. We assessed the influence of crossword puzzle participation on the onset of accelerated memory decline as measured by the Buschke Selective Reminding Test in 101 individuals who developed incident dementia using a change point model. Crossword puzzle participation at baseline delayed onset of accelerated memory decline by 2.54 years. Inclusion of education or participation in other cognitively stimulating activities did not significantly add to the fit of the model beyond the effect of puzzles. Our findings show that late life crossword puzzle participation, independent of education, was associated with delayed onset of memory decline in persons who developed dementia. Given the wide availability and accessibility of crossword puzzles, their role in preventing cognitive decline should be validated in future clinical trials. PMID:22040899

Nature's Greatest Puzzles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Quigg, Chris; /Fermilab

2005-02-01

It is a pleasure to be part of the SLAC Summer Institute again, not simply because it is one of the great traditions in our field, but because this is a moment of great promise for particle physics. I look forward to exploring many opportunities with you over the course of our two weeks together. My first task in talking about Nature's Greatest Puzzles, the title of this year's Summer Institute, is to deconstruct the premise a little bit.

Characteristics of steady vibration in a rotating hub-beam system

NASA Astrophysics Data System (ADS)

Zhao, Zhen; Liu, Caishan; Ma, Wei

2016-02-01

A rotating beam features a puzzling character in which its frequencies and modal shapes may vary with the hub's inertia and its rotating speed. To highlight the essential nature behind the vibration phenomena, we analyze the steady vibration of a rotating Euler-Bernoulli beam with a quasi-steady-state stretch. Newton's law is used to derive the equations governing the beam's elastic motion and the hub's rotation. A combination of these equations results in a nonlinear partial differential equation (PDE) that fully reflects the mutual interaction between the two kinds of motion. Via the Fourier series expansion within a finite interval of time, we reduce the PDE into an infinite system of a nonlinear ordinary differential equation (ODE) in spatial domain. We further nondimensionalize the ODE and discretize it via a difference method. The frequencies and modal shapes of a general rotating beam are then determined numerically. For a low-speed beam where the ignorance of geometric stiffening is feasible, the beam's vibration characteristics are solved analytically. We validate our numerical method and the analytical solutions by comparing with either the past experiments or the past numerical findings reported in existing literature. Finally, systematic simulations are performed to demonstrate how the beam's eigenfrequencies vary with the hub's inertia and rotating speed.

Construction-Paper Puzzle Masterpieces

ERIC Educational Resources Information Center

Vance, Shelly

2010-01-01

Creating an appreciation of art history in her junior-high students has always been one of the author's greatest challenges as an art teacher. In this article, the author describes how her eighth-grade students re-created a famous work of art--piece by piece, like a puzzle or a stained-glass window--out of construction paper. (Contains 1 resource.)

An Alternative Evaluation: Online Puzzle as a Course-End Activity

ERIC Educational Resources Information Center

Genç, Zülfü; Aydemir, Emrah

2015-01-01

Purpose: The purpose of this study is to determine whether the use of online puzzles in the instructional process has an effect on student achievement and learning retention. This study examined students ' perception and experiences on use of puzzle as an alternative evaluation tool. To achieve this aim, the following hypotheses were tested: using…

The Puzzle of Science; Making Sense of Incomplete Information

NASA Astrophysics Data System (ADS)

Shorey, B. U.

2015-12-01

There are many topics within Earth science including evolution, historical geology, and climate change, which have gained the status of theory becuse they have overwhelming evidence, yet there is still fragmentary information which can frustrate a student from coming to solid conclusions. Using a jigsaw puzzle whose image has been hidden, and the pieces only given out sparingly, students go though the process of getting more information. How does one get more puzzle pieces and what is the interpretive process? Experience with this exercise demonstrates how students can sketch out an incredibly accurate conception of the "big picture", despite not having all the puzzle pieces. The goal of this talk is to give a complete tool kit to perform as a comprehensive lesson plan. Guiding questions and copies of lesson plans and materials are supplied for this exercise.

Puzzle-based learning in engineering mathematics: students' attitudes

NASA Astrophysics Data System (ADS)

Klymchuk, Sergiy

2017-11-01

The article reports on the results of two case studies on the impact of the regular use of puzzles as a pedagogical strategy in the teaching and learning of engineering mathematics. The intention of using puzzles is to engage students' emotions, creativity and curiosity and also to enhance their generic thinking skills and lateral thinking 'outside the box'. Students' attitudes towards this pedagogical strategy are evaluated via short questionnaires with two groups of university students taking a second-year engineering mathematics course. Students' responses to the questionnaire are presented and analyzed in the paper.

Teaching Inductive Reasoning with Puzzles

ERIC Educational Resources Information Center

Wanko, Jeffrey J.

2017-01-01

Working with language-independent logic structures can help students develop both inductive and deductive reasoning skills. The Japanese publisher Nikoli (with resources available both in print and online) produces a treasure trove of language-independent logic puzzles. The Nikoli print resources are mostly in Japanese, creating the extra…

Two-Dimensional Parson's Puzzles: The Concept, Tools, and First Observations

ERIC Educational Resources Information Center

Ihantola, Petri; Karavirta, Ville

2011-01-01

Parson's programming puzzles are a family of code construction assignments where lines of code are given, and the task is to form the solution by sorting and possibly selecting the correct code lines. We introduce a novel family of Parson's puzzles where the lines of code need to be sorted in two dimensions. The vertical dimension is used to order…

The impact of memory load and perceptual cues on puzzle learning by 24-month olds.

PubMed

Barr, Rachel; Moser, Alecia; Rusnak, Sylvia; Zimmermann, Laura; Dickerson, Kelly; Lee, Herietta; Gerhardstein, Peter

2016-11-01

Early childhood is characterized by memory capacity limitations and rapid perceptual and motor development [Rovee-Collier (1996). Infant Behavior & Development, 19, 385-400]. The present study examined 2-year olds' reproduction of a sliding action to complete an abstract fish puzzle under different levels of memory load and perceptual feature support. Experimental groups were compared to baseline controls to assess spontaneous rates of production of the target actions; baseline production was low across all experiments. Memory load was manipulated in Exp. 1 by adding pieces to the puzzle, increasing sequence length from 2 to 3 items, and to 3 items plus a distractor. Although memory load did not influence how toddlers learned to manipulate the puzzle pieces, it did influence toddlers' achievement of the goal-constructing the fish. Overall, girls were better at constructing the puzzle than boys. In Exp. 2, the perceptual features of the puzzle were altered by changing shape boundaries to create a two-piece horizontally cut puzzle (displaying bilateral symmetry), and by adding a semantically supportive context to the vertically cut puzzle (iconic). Toddlers were able to achieve the goal of building the fish equally well across the 2-item puzzle types (bilateral symmetry, vertical, iconic), but how they learned to manipulate the puzzle pieces varied as a function of the perceptual features. Here, as in Exp. 1, girls showed a different pattern of performance from the boys. This study demonstrates that changes in memory capacity and perceptual processing influence both goal-directed imitation learning and motoric performance. © 2016 Wiley Periodicals, Inc.

The Computational Complexity of the Kakuro Puzzle, Revisited

NASA Astrophysics Data System (ADS)

Ruepp, Oliver; Holzer, Markus

We present a new proof of NP-completeness for the problem of solving instances of the Japanese pencil puzzle Kakuro (also known as Cross-Sum). While the NP-completeness of Kakuro puzzles has been shown before [T. Seta. The complexity of CROSS SUM. IPSJ SIG Notes, AL-84:51-58, 2002], there are still two interesting aspects to our proof: we show NP-completeness for a new variant of Kakuro that has not been investigated before and thus improves the aforementioned result. Moreover some parts of the proof have been generated automatically, using an interesting technique involving SAT solvers.

Japanese Logic Puzzles and Proof

ERIC Educational Resources Information Center

Wanko, Jeffrey J.

2009-01-01

An understanding of proof does not start in a high school geometry course. Rather, attention to logical reasoning throughout a student's school experience can help the development of proof readiness. In the spirit of problem solving, the author has begun to use some Japanese logic puzzles other than sudoku to help students develop additional…

Rotational homogeneity in graphene grown on Au(111)

NASA Astrophysics Data System (ADS)

Wofford, Joseph; Starodub, Elena; Walter, Andrew; Nie, Shu; Bostwick, Aaron; Bartelt, Norman; Thürmer, Konrad; Rotenberg, Eli; McCarty, Kevin; Dubon, Oscar

2012-02-01

The set of properties offered by the (111) surface of gold makes it intriguing as a platform on which to study the fundamental processes that underpin graphene growth on metals. Among these are the low carbon solubility and an interaction strength with graphene that is predicted to be smaller than most transition metals. We have investigated this synthesis process using low-energy electron microscopy and diffraction to monitor the sample surface in real time, and found that the resulting graphene film possesses a remarkable degree of rotational homogeneity. The dominant orientation of the graphene is aligned with the Au lattice, with a small minority rotated by 30 degrees. The origins of this in-plane structuring are puzzling because angularly resolved photo-emission spectroscopy and scanning tunneling microscopy experiments both suggest only a relatively small interaction between the two materials. Finally, the implications of these findings for the growth of high structural-quality graphene films are discussed.

Puzzle Imaging: Using Large-Scale Dimensionality Reduction Algorithms for Localization.

PubMed

Glaser, Joshua I; Zamft, Bradley M; Church, George M; Kording, Konrad P

2015-01-01

Current high-resolution imaging techniques require an intact sample that preserves spatial relationships. We here present a novel approach, "puzzle imaging," that allows imaging a spatially scrambled sample. This technique takes many spatially disordered samples, and then pieces them back together using local properties embedded within the sample. We show that puzzle imaging can efficiently produce high-resolution images using dimensionality reduction algorithms. We demonstrate the theoretical capabilities of puzzle imaging in three biological scenarios, showing that (1) relatively precise 3-dimensional brain imaging is possible; (2) the physical structure of a neural network can often be recovered based only on the neural connectivity matrix; and (3) a chemical map could be reproduced using bacteria with chemosensitive DNA and conjugative transfer. The ability to reconstruct scrambled images promises to enable imaging based on DNA sequencing of homogenized tissue samples.

Puzzle Imaging: Using Large-Scale Dimensionality Reduction Algorithms for Localization

PubMed Central

Glaser, Joshua I.; Zamft, Bradley M.; Church, George M.; Kording, Konrad P.

2015-01-01

Current high-resolution imaging techniques require an intact sample that preserves spatial relationships. We here present a novel approach, “puzzle imaging,” that allows imaging a spatially scrambled sample. This technique takes many spatially disordered samples, and then pieces them back together using local properties embedded within the sample. We show that puzzle imaging can efficiently produce high-resolution images using dimensionality reduction algorithms. We demonstrate the theoretical capabilities of puzzle imaging in three biological scenarios, showing that (1) relatively precise 3-dimensional brain imaging is possible; (2) the physical structure of a neural network can often be recovered based only on the neural connectivity matrix; and (3) a chemical map could be reproduced using bacteria with chemosensitive DNA and conjugative transfer. The ability to reconstruct scrambled images promises to enable imaging based on DNA sequencing of homogenized tissue samples. PMID:26192446

Puzzle based teaching versus traditional instruction in electrocardiogram interpretation for medical students--a pilot study.

PubMed

Rubinstein, Jack; Dhoble, Abhijeet; Ferenchick, Gary

2009-01-13

Most medical professionals are expected to possess basic electrocardiogram (EKG) interpretation skills. But, published data suggests that residents' and physicians' EKG interpretation skills are suboptimal. Learning styles differ among medical students; individualization of teaching methods has been shown to be viable and may result in improved learning. Puzzles have been shown to facilitate learning in a relaxed environment. The objective of this study was to assess efficacy of teaching puzzle in EKG interpretation skills among medical students. This is a reader blinded crossover trial. Third year medical students from College of Human Medicine, Michigan State University participated in this study. Two groups (n = 9) received two traditional EKG interpretation skills lectures followed by a standardized exam and two extra sessions with the teaching puzzle and a different exam. Two other groups (n = 6) received identical courses and exams with the puzzle session first followed by the traditional teaching. EKG interpretation scores on final test were used as main outcome measure. The average score after only traditional teaching was 4.07 +/- 2.08 while after only the puzzle session was 4.04 +/- 2.36 (p = 0.97). The average improvement after the traditional session was followed up with a puzzle session was 2.53 +/- 1.94 while the average improvement after the puzzle session was followed with the traditional session was 2.08 +/- 1.73 (p = 0.67). The final EKG exam score for this cohort (n = 15) was 84.1 compared to 86.6 (p = 0.22) for a comparable sample of medical students (n = 15) at a different campus. Teaching EKG interpretation with puzzles is comparable to traditional teaching and may be particularly useful for certain subgroups of students. Puzzle session are more interactive and relaxing, and warrant further investigations on larger scale.

Usefulness of Crossword Puzzles in Helping First-Year BVSc Students Learn Veterinary Terminology.

PubMed

Abuelo, Angel; Castillo, Cristina; May, Stephen A

Appropriate terminology is essential for successful communication among health professionals. However, students have traditionally been encouraged to learn terminology by rote memorization and recall, strategies that students try to avoid. The use of crossword puzzles as a learning tool has been evaluated in other education disciplines, but not for terminology related to veterinary science. Hence, the objective of this study was to test whether crossword puzzles might be an effective aid to learning veterinary terminology. Forty-two first-year students enrolled in a Bachelor of Veterinary Science program were randomly divided into two groups and their previous knowledge of veterinary terms tested. One group received a list of 30 terms with their definitions. The other group received the same list plus six specially designed puzzles incorporating these 30 terms. After 50 minutes, both groups completed a post-intervention test and the results were compared statistically. The results showed that the students using the crossword puzzles performed better in the post-intervention test, correctly retaining more terms than the students using only rote learning. In addition, qualitative data, gathered through an electronic survey and focus group discussions, revealed a positive attitude among students toward the use of crossword puzzles.

Crossword Puzzle Makes It Fun: Introduce Green Manufacturing in Wood Technology Courses

ERIC Educational Resources Information Center

Iley, John L.; Hague, Doug

2012-01-01

Sustainable, or "green," manufacturing and its practices are becoming more and more a part of today's industry, including wood product manufacturing. This article provides introductory information on green manufacturing in wood technology and a crossword puzzle based on green manufacturing terms. The authors use the puzzle at the college level to…

What Puzzles Teachers in Rio de janeiro, and What Keeps Them Going?

ERIC Educational Resources Information Center

Lyra, Isolina; Fish, Solange; Braga, Walewska Gomes

2003-01-01

Focuses on the key mechanism of "puzzling" in Exploratory Practice (EP), a form of practitioner research, and the critical issue of sustainability in the context of volunteer teacher development work in Rio de Janeiro, Brazil. Investigated puzzles (concerns) of language teachers and grouped them into six categories; motivation, anxiety,…

Common Mechanisms of DNA translocation motors in Bacteria and Viruses Using One-way Revolution Mechanism without Rotation

PubMed Central

Guo, Peixuan; Zhao, Zhengyi; Haak, Jeannie; Wang, Shaoying; Weitao, Tao

2014-01-01

Biomotors were once classified into two categories: linear motor and rotation motor. For decades, the viral DNA-packaging motor has been popularly believed to be a five-fold rotation motor. Recently, a third type of biomotor with revolution mechanism without rotation has been discovered. By analogy, rotation resembles the Earth rotating on its axis in a complete cycle every 24 hours, while revolution resembles the Earth revolving around the Sun one circle per 365 days (see animations http://nanobio.uky.edu/movie.html). The action of revolution that enables a motor free of coiling and torque has solved many puzzles and debates that have occurred throughout the history of viral DNA packaging motor studies. It also settles the discrepancies concerning the structure, stoichiometry, and functioning of DNA translocation motors. This review uses bacteriophages Phi29, HK97, SPP1, P22, T4, T7 as well as bacterial DNA translocase FtsK and SpoIIIE as examples to elucidate the puzzles. These motors use a ATPase, some of which have been confirmed to be a hexamer, to revolve around the dsDNA sequentially. ATP binding induces conformational change and possibly an entropy alteration in ATPase to a high affinity toward dsDNA; but ATP hydrolysis triggers another entropic and conformational change in ATPase to a low affinity for DNA, by which dsDNA is pushed toward an adjacent ATPase subunit. The rotation and revolution mechanisms can be distinguished by the size of channel: the channels of rotation motors are equal to or smaller than 2 nm, whereas channels of revolution motors are larger than 3 nm. Rotation motors use parallel threads to operate with a right-handed channel, while revolution motors use a left-handed channel to drive the right-handed DNA in an anti-parallel arrangement. Coordination of several vector factors in the same direction makes viral DNA-packaging motors unusually powerful and effective. Revolution mechanism avoids DNA coiling in translocating the lengthy

An Empirical Evaluation of Puzzle-Based Learning as an Interest Approach for Teaching Introductory Computer Science

ERIC Educational Resources Information Center

Merrick, K. E.

2010-01-01

This correspondence describes an adaptation of puzzle-based learning to teaching an introductory computer programming course. Students from two offerings of the course--with and without the puzzle-based learning--were surveyed over a two-year period. Empirical results show that the synthesis of puzzle-based learning concepts with existing course…

Electromotive force due to magnetohydrodynamic fluctuations in sheared rotating turbulence

DOE PAGES

Squire, J.; Bhattacharjee, A.

2015-11-02

Here, this article presents a calculation of the mean electromotive force arising from general small-scale magnetohydrodynamical turbulence, within the framework of the second-order correlation approximation. With the goal of improving understanding of the accretion disk dynamo, effects arising through small-scale magnetic fluctuations, velocity gradients, density and turbulence stratification, and rotation, are included. The primary result, which supplements numerical findings, is that an off-diagonal turbulent resistivity due to magnetic fluctuations can produce large-scale dynamo action-the magnetic analog of the "shear-current" effect. In addition, consideration of alpha effects in the stratified regions of disks gives the puzzling result that there is nomore » strong prediction for a sign of alpha, since the effects due to kinetic and magnetic fluctuations, as well as those due to shear and rotation, are each of opposing signs and tend to cancel each other.« less

A Puzzling Alcohol Dehydration Reaction Solved by GC-MS Analysis

NASA Astrophysics Data System (ADS)

Pelter, Michael W.; Macudzinski, Rebecca M.

1999-06-01

We have adapted the dehydration of 2-methyl-2-propanol to a "puzzle" approach for use in our second-semester chemistry major organic laboratory. The reaction of 2-methyl-2-propanol with ~50% sulfuric acid at 100 °C yields isobutylene, which reacts further by a "puzzling" reaction. By coupling the GC/MS analysis of the product mixture with their knowledge of the mechanism of alcohol dehydration and alkene reactivity, students are able to identify the major products of this reaction.

Dissolving the Puzzle of Resultant Moral Luck.

PubMed

Levy, Neil

The puzzle of resultant moral luck arises when we are disposed to think that an agent who caused a harm deserves to be blamed more than an otherwise identical agent who did not. One popular (but controversial) perspective on resultant moral luck explains our dispositions to produce different judgments with regard to the agents who feature in these cases as a product not of what they genuinely deserve but of our epistemic situation. On this account, there is no genuine resultant moral luck; there is only luck in what evidence becomes available to observers. In this paper, I develop an evolutionary account of our inclination to take the results of actions as evidence for the mental states of agents, thereby explaining why the resulting intuitions are recalcitrant to correction. The account explains why the puzzle of resultant moral luck arises: because our disposition to take the harms agents cause as evidence of their mental states can produce intuitions which conflict with those that arise when we examine agents' mental states without reference to the results of their actions. The account also helps to solve the puzzle of resultant moral luck, by providing a strong reason to ignore the intuitions caused by our disposition to regard actual harms as evidence of mental states. Since these intuitions arise using an unreliable proxy for agents' mental states, they ought to be trumped by more reliable evidence.

[Educational Therapy Using Games and Puzzles.

ERIC Educational Resources Information Center

Locker, Chava

Ways in which games can be used as tools in observing, diagnosing, and providing educational therapy for learning dysfunctions are listed and described in a series of four related papers: (a) "Educational Therapy for Learning Dysfunctions"; (2) "Educational Therapy and Puzzles"; (3) "Educational Therapy and Reading Fluency"; and (4) "Spelling…

Comparison of short-range-order in liquid- and rotator-phase states of a simple molecular liquid: A reverse Monte Carlo and molecular dynamics analysis of neutron diffraction data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pardo, Luis Carlos; Tamarit, Josep Lluis; Veglio, Nestor

2007-10-01

The short-range order (SRO) correlations in liquid- and rotator-phase states of carbon tetrachloride are revisited here. The correlation of some angular magnitudes is used to evaluate the positional and orientational correlations in the liquid as well as in the rotator phase. The results show significant similitudes in the relative position of the molecules surrounding a central one but striking differences in their relative orientations, which could explain the changes in SRO between the two phases and the puzzling behavior of the local density in the liquid and rotator phases.

Track Reconstruction and the Proton Radius Puzzle

NASA Astrophysics Data System (ADS)

Clark, Steven; Cline, Ethan; Gilman, Ron; MUSE Collaboration

2017-09-01

In 2010, Pohl et al. measured the proton charge radius to be 0.84184(67) fm using muonic hydrogen spectroscopy. This value differs about 5 σ from the CODATA proton radius from measurements with electrons. Other experiments with muons and electrons have confirmed the difference and the discrepancy has been termed the `Proton Radius Puzzle.' Currently there are no explanations for the puzzle. The MUon proton Scattering Experiment (MUSE) will make a significant measurement of the proton radius with muon scattering for the first time. The experiment tracks elastic scattering of electrons and muons off of liquid hydrogen. Particle tracks are reconstructed with track fitting software GenFit. Using a simulation of MUSE, GenFit has been determined to be proficient at track reconstruction. This project has been supported by funding from National Science Foundation Grant PHY-1560077.

Effect of a puzzle on the process of students' learning about cardiac physiology.

PubMed

Cardozo, Lais Tono; Miranda, Aline Soares; Moura, Maria José Costa Sampaio; Marcondes, Fernanda Klein

2016-09-01

The aim of the present study was to evaluate the effects of using a puzzle to learn about cardiac physiology. Students were divided into control and game groups. In class 1, the control group had a 2-h theoretical class about cardiac physiology, including a detailed description of the phases of the cardiac cycle, whereas the game group had a 50-min theoretical class without the description of the cardiac cycle. In class 2, the control group did an assessment exercise before an activity with the cardiac puzzle and the game group answered questions after the above-mentioned activity. While solving the puzzle, the students had to describe the cardiac cycle by relating the concepts of heart morphology and physiology. To evaluate short-term learning, the number of wrong answers and grades in the assessment exercise were compared between the control and game groups. To evaluate medium-term learning, we compared the grades obtained by students of the control and game groups in questions about cardiac physiology that formed part of the academic exam. In the assessment exercise, the game group presented a lower number of errors and higher score compared with the control group. In the academic exam, applied after both groups had used the puzzle, there was no difference in the scores obtained by the control and game groups in questions about cardiac physiology. These results showed a positive effect of the puzzle on students' learning about cardiac physiology compared with those not using the puzzle. Copyright © 2016 The American Physiological Society.

Puzzle based teaching versus traditional instruction in electrocardiogram interpretation for medical students – a pilot study

PubMed Central

Rubinstein, Jack; Dhoble, Abhijeet; Ferenchick, Gary

2009-01-01

Background Most medical professionals are expected to possess basic electrocardiogram (EKG) interpretation skills. But, published data suggests that residents' and physicians' EKG interpretation skills are suboptimal. Learning styles differ among medical students; individualization of teaching methods has been shown to be viable and may result in improved learning. Puzzles have been shown to facilitate learning in a relaxed environment. The objective of this study was to assess efficacy of teaching puzzle in EKG interpretation skills among medical students. Methods This is a reader blinded crossover trial. Third year medical students from College of Human Medicine, Michigan State University participated in this study. Two groups (n = 9) received two traditional EKG interpretation skills lectures followed by a standardized exam and two extra sessions with the teaching puzzle and a different exam. Two other groups (n = 6) received identical courses and exams with the puzzle session first followed by the traditional teaching. EKG interpretation scores on final test were used as main outcome measure. Results The average score after only traditional teaching was 4.07 ± 2.08 while after only the puzzle session was 4.04 ± 2.36 (p = 0.97). The average improvement after the traditional session was followed up with a puzzle session was 2.53 ± 1.94 while the average improvement after the puzzle session was followed with the traditional session was 2.08 ± 1.73 (p = 0.67). The final EKG exam score for this cohort (n = 15) was 84.1 compared to 86.6 (p = 0.22) for a comparable sample of medical students (n = 15) at a different campus. Conclusion Teaching EKG interpretation with puzzles is comparable to traditional teaching and may be particularly useful for certain subgroups of students. Puzzle session are more interactive and relaxing, and warrant further investigations on larger scale. PMID:19144134

Economics, human biology and inequality: A review of "puzzles" and recent contributions from a Deatonian perspective.

PubMed

Baten, Joerg

2017-05-01

The Nobel laureate Angus Deaton concentrated his work on puzzling developments and phenomena in economics. Puzzles are exciting elements in economics, because readers feel challenged by the question of how they can be solved. Among the puzzles analyzed by Deaton are: (1) Mortality increase of white, U.S. non-Hispanic men (2000 to today); (2) Why are height and income sometimes closely correlated, but not always?; (3) Height inequality among males and females; and (4) The Indian puzzle of declining consumption of calories during overall expenditure growth. This article reviews these "puzzles" and the main insights that Deaton derived from their discussion insofar as they pertain to the biological aspects of human development. I will focus on the field of this journal, Economics and Human Biology, in which Deaton has been very active over the last two decades. I will also document some of the responses by other scholars and their contributions to these puzzles, as they relate to the field of economics and human biology. Copyright © 2016 Elsevier B.V. All rights reserved.

Free-style puzzle flap: the concept of recycling a perforator flap.

PubMed

Feng, Kuan-Ming; Hsieh, Ching-Hua; Jeng, Seng-Feng

2013-02-01

Theoretically, a flap can be supplied by any perforator based on the angiosome theory. In this study, the technique of free-style perforator flap dissection was used to harvest a pedicled or free skin flap from a previous free flap for a second difficult reconstruction. The authors call this a free-style puzzle flap. For the past 3 years, the authors treated 13 patients in whom 12 pedicled free-style puzzle flaps were harvested from previous redundant free flaps and recycled to reconstruct soft-tissue defects at various anatomical locations. One free-style free puzzle flap was harvested from a previous anterolateral thigh flap for buccal cancer to reconstruct a foot defect. Total flap survival was attained in 12 of 13 flaps. One transferred flap failed completely. This patient had received postoperative radiotherapy after the initial cancer ablation and free anterolateral thigh flap reconstruction. Another free flap was used to close and reconstruct the wound. All the donor sites could be closed primarily. The free-style puzzle flap, harvested from a previous redundant free flap and used as a perforator flap to reconstruct a new defect, has proven to be versatile and reliable. When indicated, it is an alternative donor site for further reconstruction of soft-tissue defects.

Family caregivers of palliative cancer patients at home: the puzzle of pain management.

PubMed

Mehta, Anita; Cohen, S Robin; Carnevale, Franco A; Ezer, Hélène; Ducharme, Francine

2010-01-01

The purpose of this grounded theory study was to understand the processes used by family caregivers to manage the pain of cancer patients at home. A total of 24 family caregivers participated. They were recruited using purposeful then theoretical sampling. The data sources were taped, transcribed (semi-structured) interviews and field notes. Data analysis was based on Strauss and Corbin's (1998) requirements for open, axial, and selective coding. The result was an explanatory model titled "the puzzle of pain management," which includes four main processes: "drawing on past experiences"; "strategizing a game plan"; "striving to respond to pain"; and "gauging the best fit," a decision-making process that joins the puzzle pieces. Understanding how family caregivers assemble their puzzle pieces can help health care professionals make decisions related to the care plans they create for pain control and help them to recognize the importance of providing information as part of resolving the puzzle of pain management.

Neutron star news and puzzles

NASA Astrophysics Data System (ADS)

Prakash, Madappa

2014-08-01

Gerry Brown has had the most influence on my career in Physics, and my life after graduate studies. This article gives a brief account of some of the many ways in which Gerry shaped my research. Focus is placed on the significant strides on neutron star research made by the group at Stony Brook, which Gerry built from scratch. Selected puzzles about neutron stars that remain to be solved are noted.

3D satellite puzzles for young and old kids

NASA Astrophysics Data System (ADS)

Biondi, Riccardo; Galoforo, Germana

2017-04-01

The Italian Space Agency (ASI) is active in outreach willing to increase the interest of young generations and general public toward the space activities. ASI proposes educational programmes for supporting and encouraging the development of European society based on knowledge, inspiring and motivating the young generations. One of the initiatives promoted by ASI on this regards is the 3D satellite puzzles. The idea was born in 2007 from the will to conceive an educational product for promoting and explaining to students the small all-Italian mission AGILE (Astrorivelatore Gamma ad Immagini ultra Leggero) thought as a tool for students aged 8-13. Working with this slot of students is very productive in terms of the imprints left on the kids, in fact it is useful to produce things they can use, touch and play with, with an active approach instead of a passive one. Therefore it was decided to produce something that kids could build and use at home with their parents or friends, or all together at school with teachers and mates. Other puzzles followed AGILE, one about the COSMO-SkyMED satellites about Earth Observation and also a broader one of the International Space Station. During these 10 years the puzzles were mostly used as outreach tools for school children, but they surprisingly received a great success also within older generations. So far the 3D puzzles have been printed in more than 10 thousand copies and distributed for free to students of hundreds of schools in Italy, and to the general public through science associations, planetaria and museums. Recently they have been used also during special events such as the international Geoscience Communication School (as best practice outreach tool), the EXPO 2015 and the European Researcheŕs Night at the Parlamentarium in Brussels 2016. While the students are building the puzzles, the tutor explains them the different components that they are assembling, what the importance of the satellite is and how it works

Reinforcing Geometric Properties with Shapedoku Puzzles

ERIC Educational Resources Information Center

Wanko, Jeffrey J.; Nickell, Jennifer V.

2013-01-01

Shapedoku is a new type of puzzle that combines logic and spatial reasoning with understanding of basic geometric concepts such as slope, parallelism, perpendicularity, and properties of shapes. Shapedoku can be solved by individuals and, as demonstrated here, can form the basis of a review for geometry students as they create their own. In this…

Lorentz violation in the gravity sector: The t puzzle

NASA Astrophysics Data System (ADS)

Bonder, Yuri

2015-06-01

Lorentz violation is a candidate quantum-gravity signal, and the Standard-Model Extension (SME) is a widely used parametrization of such a violation. In the gravitational SME sector, there is an elusive coefficient for which no effects have been found. This is known as the t puzzle and, to date, it has no compelling explanation. This paper analyzes whether there is a fundamental explanation for the t puzzle. To tackle this question, several approaches are followed. Mainly, redefinitions of the dynamical fields are studied, showing that other SME coefficients can be moved to nongravitational sectors. It is also found that the gravity SME sector can be consistently treated à la Palatini, and that, in the presence of spacetime boundaries, it is possible to correct its action to get the desired equations of motion. Moreover, through a reformulation as a Lanczos-type tensor, some problematic features of the t term, which should arise at the phenomenological level, are revealed. The most important conclusion of the paper is that there is no evidence of a fundamental explanation for the t puzzle, suggesting that it may be linked to the approximations taken at the phenomenological level.

Common mechanisms of DNA translocation motors in bacteria and viruses using one-way revolution mechanism without rotation.

PubMed

Guo, Peixuan; Zhao, Zhengyi; Haak, Jeannie; Wang, Shaoying; Wu, Dong; Meng, Bing; Weitao, Tao

2014-01-01

Biomotors were once described into two categories: linear motor and rotation motor. Recently, a third type of biomotor with revolution mechanism without rotation has been discovered. By analogy, rotation resembles the Earth rotating on its axis in a complete cycle every 24h, while revolution resembles the Earth revolving around the Sun one circle per 365 days (see animations http://nanobio.uky.edu/movie.html). The action of revolution that enables a motor free of coiling and torque has solved many puzzles and debates that have occurred throughout the history of viral DNA packaging motor studies. It also settles the discrepancies concerning the structure, stoichiometry, and functioning of DNA translocation motors. This review uses bacteriophages Phi29, HK97, SPP1, P22, T4, and T7 as well as bacterial DNA translocase FtsK and SpoIIIE or the large eukaryotic dsDNA viruses such as mimivirus and vaccinia virus as examples to elucidate the puzzles. These motors use ATPase, some of which have been confirmed to be a hexamer, to revolve around the dsDNA sequentially. ATP binding induces conformational change and possibly an entropy alteration in ATPase to a high affinity toward dsDNA; but ATP hydrolysis triggers another entropic and conformational change in ATPase to a low affinity for DNA, by which dsDNA is pushed toward an adjacent ATPase subunit. The rotation and revolution mechanisms can be distinguished by the size of channel: the channels of rotation motors are equal to or smaller than 2 nm, that is the size of dsDNA, whereas channels of revolution motors are larger than 3 nm. Rotation motors use parallel threads to operate with a right-handed channel, while revolution motors use a left-handed channel to drive the right-handed DNA in an anti-chiral arrangement. Coordination of several vector factors in the same direction makes viral DNA-packaging motors unusually powerful and effective. Revolution mechanism that avoids DNA coiling in translocating the lengthy genomic

Children with Prader-Willi syndrome vs. Williams syndrome: indirect effects on parents during a jigsaw puzzle task.

PubMed

Ly, T M; Hodapp, R M

2005-12-01

Genetic disorders predispose individuals to exhibit characteristic behaviours, which in turn elicit particular behaviours from others. In response to the strength of Prader-Willi syndrome (PWS) and weakness of Williams syndrome (WS) in visual-spatial tasks such as jigsaw puzzles, parents' behaviours can be affected by their child's level of puzzle ability or syndrome diagnosis. Children were asked to complete two jigsaw puzzles (one with the experimenter and the other with the parent) for 5 min each. Frequencies of parental helping and reinforcement behaviours, along with ratings of parental directiveness, were examined as parents interacted with their children on a jigsaw puzzle task. Within each aetiological group, correlates of parental behaviours with child characteristics were also examined. Compared to parents of children with PWS, parents of children with WS engaged in a more directive style of interaction, and provided more help and reinforcement. Relative to parents of children with higher puzzle abilities (from both aetiologies), parents of children with lower abilities also showed the same pattern. Both the child's aetiology and puzzle abilities were important in predicting parents' directiveness and helping and reinforcement behaviours. Within the PWS group, parents' behaviours correlated negatively with the child's puzzle abilities and general cognitive functioning; no such relations occurred in the WS group. Parents' behaviours were affected by both the child's diagnosis and actual puzzle abilities, suggesting important implications for understanding and intervening with parents and children with different genetic syndromes.

Exploring Organic Mechanistic Puzzles with Molecular Modeling

ERIC Educational Resources Information Center

Horowitz, Gail; Schwartz, Gary

2004-01-01

The molecular modeling was used to reinforce more general skills such as deducing and drawing reaction mechanisms, analyzing reaction kinetics and thermodynamics and drawing reaction coordinate energy diagrams. This modeling was done through the design of mechanistic puzzles, involving reactions not familiar to the students.

Formative Assessment Probes: Mountaintop Fossil: A Puzzling Phenomenon

ERIC Educational Resources Information Center

Keeley, Page

2015-01-01

This column focuses on promoting learning through assessment. This month's issue describes using formative assessment probes to uncover several ways of thinking about the puzzling discovery of a marine fossil on top of a mountain.

Particle Filter with State Permutations for Solving Image Jigsaw Puzzles

PubMed Central

Yang, Xingwei; Adluru, Nagesh; Latecki, Longin Jan

2016-01-01

We deal with an image jigsaw puzzle problem, which is defined as reconstructing an image from a set of square and non-overlapping image patches. It is known that a general instance of this problem is NP-complete, and it is also challenging for humans, since in the considered setting the original image is not given. Recently a graphical model has been proposed to solve this and related problems. The target label probability function is then maximized using loopy belief propagation. We also formulate the problem as maximizing a label probability function and use exactly the same pairwise potentials. Our main contribution is a novel inference approach in the sampling framework of Particle Filter (PF). Usually in the PF framework it is assumed that the observations arrive sequentially, e.g., the observations are naturally ordered by their time stamps in the tracking scenario. Based on this assumption, the posterior density over the corresponding hidden states is estimated. In the jigsaw puzzle problem all observations (puzzle pieces) are given at once without any particular order. Therefore, we relax the assumption of having ordered observations and extend the PF framework to estimate the posterior density by exploring different orders of observations and selecting the most informative permutations of observations. This significantly broadens the scope of applications of the PF inference. Our experimental results demonstrate that the proposed inference framework significantly outperforms the loopy belief propagation in solving the image jigsaw puzzle problem. In particular, the extended PF inference triples the accuracy of the label assignment compared to that using loopy belief propagation. PMID:27795660

Discovery of a new motion mechanism of biomotors similar to the earth revolving around the sun without rotation

PubMed Central

Guo, Peixuan; Schwartz, Chad; Haak, Jeannie; Zhao, Zhengyi

2013-01-01

Biomotors have been classified into linear and rotational motors. For 35 years, it has been popularly believed that viral dsDNA-packaging apparatuses are pentameric rotation motors. Recently, a third class of hexameric motor has been found in bacteriophage phi29 that utilizes a mechanism of revolution without rotation, friction, coiling, or torque. This review addresses how packaging motors control dsDNA one-way traffic; how four electropositive layers in the channel interact with the electronegative phosphate backbone to generate four steps in translocating one dsDNA helix; how motors resolve the mismatch between 10.5 bases and 12 connector subunits per cycle of revolution; and how ATP regulates sequential action of motor ATPase. Since motors with all number of subunits can utilize the revolution mechanism, this finding helps resolve puzzles and debates concerning the oligomeric nature of packaging motors in many phage systems. This revolution mechanism helps to solve the undesirable dsDNA supercoiling issue involved in rotation. PMID:24074575

The odd-even effect in Sudoku puzzles: effects of working memory, aging, and experience.

PubMed

Chang, Hye-Sang; Gibson, Janet M

2011-01-01

The odd-even effect in numerical processing has been explained as the easier processing of even numbers compared with odd numbers. We investigated this effect in Sudoku puzzles, a reasoning problem that uses numbers but does not require arithmetic operations. Specifically, we asked whether the odd-even effect occurred with Sudoku puzzles and whether individual differences in working memory (WM), aging, and experience with Sudoku modulated this effect. We manipulated the presence of odd and even numbers in Sudoku puzzles, measured WM with the Wisconsin Card Sorting Test and backward digit span task, tested older and younger adults, and collected Sudoku experience frequency. Performance on Sudoku was more accurate for even puzzles than odd ones. Younger, experienced, and higher-WM participants were more accurate on Sudoku, but these individual difference variables did not interact with the odd-even effect. Odd numbers may impose more cognitive load than even numbers, but future research is needed to examine how age, experience, or WM may influence the odd-even effect.

Piecing It Together: The Effect of Background Music on Children's Puzzle Assembly.

PubMed

Koolidge, Louis; Holmes, Robyn M

2018-04-01

This study explored the effects of background music on cognitive (puzzle assembly) task performance in young children. Participants were 87 primarily European-American children (38 boys, 49 girls; mean age = 4.77 years) enrolled in early childhood classes in the northeastern United States. Children were given one minute to complete a 12-piece puzzle task in one of three background music conditions: music with lyrics, music without lyrics, and no music. The music selection was "You're Welcome" from the Disney movie "Moana." Results revealed that children who heard the music without lyrics completed more puzzle pieces than children in either the music with lyrics or no music condition. Background music without distracting lyrics may be beneficial and superior to background music with lyrics for young children's cognitive performance even when they are engaged independently in a nonverbal task.

Variation on the similar-size disk tower of hanoi puzzle

NASA Astrophysics Data System (ADS)

Zuchri, S.

2017-02-01

The famous Tower of Hanoi puzzle was invented by Edouard Lucas in 1883. This puzzle proposed three pegs, and the number of disks with different size. The puzzle starts with the disks in a neat stack in ascending order of size on one peg, the smallest at the top. The objective of the puzzle is to move the entire stack to another peg, by following these simple rules: (1) only one disk can be moved at a time; (2) Each move consists of taking the upper disk from one of the stacks and placing it on top of another stack; (2) No disk is placed on the top of a smaller disk and the minimum number of move is the goal of this puzzle. Many variations have been proposed as exercises and challenges. Some have more than three pegs and some with colours. This paper poses a new variation. There are two or more disks with similar size. The goal is to move each stack of the disk from its initial location to its final location. As usual, disk must be moved one at a time and a disk can never sit above a disk of smaller. Let n be a number of disks and there are p similar size disks. The disks are labelled from 1 to n - p + 1 in increasing order of size so the disk with similar size has the same label. If m is the label of the similar disks, so Mp(n; m) is the minimum number moves needed to move all the disks in original peg to destination peg. We have, M2(n; m) = 2n-1 + 2n-m-1 - 1 M3(n; m) = 2n-2 + 2n-m-1 - 1 The number moves needed to move if there are p1 similar size disks m1 and p2 similar size disks m2 is Mp1,p2 (n; m1, m2) = 2n-p1-p2 + 2[(p12-m1 + p22-m2 ) - (2-m1 + 2-m2 + 1] - 1

The Incomplete Glutathione Puzzle: Just Guessing at Numbers and Figures?

PubMed

Deponte, Marcel

2017-11-20

Glutathione metabolism is comparable to a jigsaw puzzle with too many pieces. It is supposed to comprise (i) the reduction of disulfides, hydroperoxides, sulfenic acids, and nitrosothiols, (ii) the detoxification of aldehydes, xenobiotics, and heavy metals, and (iii) the synthesis of eicosanoids, steroids, and iron-sulfur clusters. In addition, glutathione affects oxidative protein folding and redox signaling. Here, I try to provide an overview on the relevance of glutathione-dependent pathways with an emphasis on quantitative data. Recent Advances: Intracellular redox measurements reveal that the cytosol, the nucleus, and mitochondria contain very little glutathione disulfide and that oxidative challenges are rapidly counterbalanced. Genetic approaches suggest that iron metabolism is the centerpiece of the glutathione puzzle in yeast. Furthermore, recent biochemical studies provide novel insights on glutathione transport processes and uncoupling mechanisms. Which parts of the glutathione puzzle are most relevant? Does this explain the high intracellular concentrations of reduced glutathione? How can iron-sulfur cluster biogenesis, oxidative protein folding, or redox signaling occur at high glutathione concentrations? Answers to these questions not only seem to depend on the organism, cell type, and subcellular compartment but also on different ideologies among researchers. A rational approach to compare the relevance of glutathione-dependent pathways is to combine genetic and quantitative kinetic data. However, there are still many missing pieces and too little is known about the compartment-specific repertoire and concentration of numerous metabolites, substrates, enzymes, and transporters as well as rate constants and enzyme kinetic patterns. Gathering this information might require the development of novel tools but is crucial to address potential kinetic competitions and to decipher uncoupling mechanisms to solve the glutathione puzzle. Antioxid. Redox Signal

Food puzzles for cats: Feeding for physical and emotional wellbeing.

PubMed

Dantas, Leticia Ms; Delgado, Mikel M; Johnson, Ingrid; Buffington, Ca Tony

2016-09-01

Many pet cats are kept indoors for a variety of reasons (eg, safety, health, avoidance of wildlife predation) in conditions that are perhaps the least natural to them. Indoor housing has been associated with health issues, such as chronic lower urinary tract signs, and development of problem behaviors, which can cause weakening of the human-animal bond and lead to euthanasia of the cat. Environmental enrichment may mitigate the effects of these problems and one approach is to take advantage of cats' natural instinct to work for their food. In this article we aim to equip veterinary professionals with the tools to assist clients in the use of food puzzles for their cats as a way to support feline physical health and emotional wellbeing. We outline different types of food puzzles, and explain how to introduce them to cats and how to troubleshoot challenges with their use. The effect of food puzzles on cats is a relatively new area of study, so as well as reviewing the existing empirical evidence, we provide case studies from our veterinary and behavioral practices showing health and behavioral benefits resulting from their use. © The Author(s) 2016.

The Crossword Puzzle as a Teaching Tool.

ERIC Educational Resources Information Center

Crossman, Edward K.

1983-01-01

In courses such as the history of psychology, it is necessary to learn a variety of relationships, events, and sequences, in addition to the task of having to pair certain key concepts with related names, e.g., phrenology--Hall. One tool useful in this type of learning is the crossword puzzle. (RM)

The King and Prisoner Puzzle: A Way of Introducing the Components of Logical Structures

ERIC Educational Resources Information Center

Roh, Kyeong Hah; Lee, Yong Hah; Tanner, Austin

2016-01-01

The purpose of this paper is to provide issues related to student understanding of logical components that arise when solving word problems. We designed a logic problem called the King and Prisoner Puzzle--a linguistically simple, yet logically challenging problem. In this paper, we describe various student solutions to the puzzle and discuss the…

Decodoku: Quantum error rorrection as a simple puzzle game

NASA Astrophysics Data System (ADS)

Wootton, James

To build quantum computers, we need to detect and manage any noise that occurs. This will be done using quantum error correction. At the hardware level, QEC is a multipartite system that stores information non-locally. Certain measurements are made which do not disturb the stored information, but which do allow signatures of errors to be detected. Then there is a software problem. How to take these measurement outcomes and determine: a) The errors that caused them, and (b) how to remove their effects. For qubit error correction, the algorithms required to do this are well known. For qudits, however, current methods are far from optimal. We consider the error correction problem of qubit surface codes. At the most basic level, this is a problem that can be expressed in terms of a grid of numbers. Using this fact, we take the inherent problem at the heart of quantum error correction, remove it from its quantum context, and presented in terms of simple grid based puzzle games. We have developed three versions of these puzzle games, focussing on different aspects of the required algorithms. These have been presented and iOS and Android apps, allowing the public to try their hand at developing good algorithms to solve the puzzles. For more information, see www.decodoku.com. Funding from the NCCR QSIT.

A puzzle form of a non-verbal intelligence test gives significantly higher performance measures in children with severe intellectual disability

PubMed Central

Bello, Katrina D; Goharpey, Nahal; Crewther, Sheila G; Crewther, David P

2008-01-01

Background Assessment of 'potential intellectual ability' of children with severe intellectual disability (ID) is limited, as current tests designed for normal children do not maintain their interest. Thus a manual puzzle version of the Raven's Coloured Progressive Matrices (RCPM) was devised to appeal to the attentional and sensory preferences and language limitations of children with ID. It was hypothesized that performance on the book and manual puzzle forms would not differ for typically developing children but that children with ID would perform better on the puzzle form. Methods The first study assessed the validity of this puzzle form of the RCPM for 76 typically developing children in a test-retest crossover design, with a 3 week interval between tests. A second study tested performance and completion rate for the puzzle form compared to the book form in a sample of 164 children with ID. Results In the first study, no significant difference was found between performance on the puzzle and book forms in typically developing children, irrespective of the order of completion. The second study demonstrated a significantly higher performance and completion rate for the puzzle form compared to the book form in the ID population. Conclusion Similar performance on book and puzzle forms of the RCPM by typically developing children suggests that both forms measure the same construct. These findings suggest that the puzzle form does not require greater cognitive ability but demands sensory-motor attention and limits distraction in children with severe ID. Thus, we suggest the puzzle form of the RCPM is a more reliable measure of the non-verbal mentation of children with severe ID than the book form. PMID:18671882

A puzzle form of a non-verbal intelligence test gives significantly higher performance measures in children with severe intellectual disability.

PubMed

Bello, Katrina D; Goharpey, Nahal; Crewther, Sheila G; Crewther, David P

2008-08-01

Assessment of 'potential intellectual ability' of children with severe intellectual disability (ID) is limited, as current tests designed for normal children do not maintain their interest. Thus a manual puzzle version of the Raven's Coloured Progressive Matrices (RCPM) was devised to appeal to the attentional and sensory preferences and language limitations of children with ID. It was hypothesized that performance on the book and manual puzzle forms would not differ for typically developing children but that children with ID would perform better on the puzzle form. The first study assessed the validity of this puzzle form of the RCPM for 76 typically developing children in a test-retest crossover design, with a 3 week interval between tests. A second study tested performance and completion rate for the puzzle form compared to the book form in a sample of 164 children with ID. In the first study, no significant difference was found between performance on the puzzle and book forms in typically developing children, irrespective of the order of completion. The second study demonstrated a significantly higher performance and completion rate for the puzzle form compared to the book form in the ID population. Similar performance on book and puzzle forms of the RCPM by typically developing children suggests that both forms measure the same construct. These findings suggest that the puzzle form does not require greater cognitive ability but demands sensory-motor attention and limits distraction in children with severe ID. Thus, we suggest the puzzle form of the RCPM is a more reliable measure of the non-verbal mentation of children with severe ID than the book form.

Mathematical History: Activities, Puzzles, Stories, and Games.

ERIC Educational Resources Information Center

Mitchell, Merle

Based on the history of mathematics, these materials have been planned to enrich the teaching of mathematics in grades four, five, and six. Puzzles and games are based on stories about topics such as famous mathematicians, numerals of ancient peoples, and numerology. The sheets are arranged by grade level and are designed for easy duplication.…

(Mis)perception of sleep in insomnia: a puzzle and a resolution.

PubMed

Harvey, Allison G; Tang, Nicole K Y

2012-01-01

Insomnia is prevalent, causing severe distress and impairment. This review focuses on illuminating the puzzling finding that many insomnia patients misperceive their sleep. They overestimate their sleep onset latency (SOL) and underestimate their total sleep time (TST), relative to objective measures. This tendency is ubiquitous (although not universal). Resolving this puzzle has clinical, theoretical, and public health importance. There are implications for assessment, definition, and treatment. Moreover, solving the puzzle creates an opportunity for real-world applications of theories from clinical, perceptual, and social psychology as well as neuroscience. Herein we evaluate 13 possible resolutions to the puzzle. Specifically, we consider the possible contribution, to misperception, of (1) features inherent to the context of sleep (e.g., darkness); (2) the definition of sleep onset, which may lack sensitivity for insomnia patients; (3) insomnia being an exaggerated sleep complaint; (4) psychological distress causing magnification; (5) a deficit in time estimation ability; (6) sleep being misperceived as wake; (7) worry and selective attention toward sleep-related threats; (8) a memory bias influenced by current symptoms and emotions, a confirmation bias/belief bias, or a recall bias linked to the intensity/recency of symptoms; (9) heightened physiological arousal; (10) elevated cortical arousal; (11) the presence of brief awakenings; (12) a fault in neuronal circuitry; and (13) there being 2 insomnia subtypes (one with and one without misperception). The best supported resolutions were misperception of sleep as wake, worry, and brief awakenings. A deficit in time estimation ability was not supported. We conclude by proposing several integrative solutions.

(Mis)Perception of Sleep in Insomnia: A puzzle and a resolution

PubMed Central

Harvey, Allison G.; Tang, Nicole

2011-01-01

Insomnia is prevalent, causing severe distress and impairment. This review focuses on illuminating the puzzling finding that many insomnia patients misperceive their sleep. They overestimate their sleep onset latency (SOL) and underestimate their total sleep time (TST), relative to objective measures. This tendency is ubiquitous (although not universal). Resolving this puzzle has clinical, theoretical, and public health importance. There are implications for assessment, definition, and treatment. Moreover, solving the puzzle creates an opportunity for "real world" applications of theories from clinical, perceptual, and social psychology as well as neuroscience. Herein we evaluate thirteen possible resolutions to the puzzle. Specifically, we consider the possible contribution, to misperception, of: (1) features inherent to the context of sleep (e.g., darkness); (2) the definition of sleep onset which may lack sensitivity for insomnia patients; (3) insomnia being an exaggerated sleep complaint; (4) psychological distress causing magnification; (5) a deficit in time estimation ability; (6) sleep being misperceived as wake; (7) worry and selective attention toward sleep-related threats; (8) a memory bias influenced by current symptoms and emotions, a confirmation bias/belief bias or a recall bias linked to the intensity/recency of symptoms; (9) heightened physiological arousal; (10) elevated cortical arousal; (11) the presence of brief awakenings; (12) a fault in neuronal circuitry; and (13) there being two insomnia subtypes (one with and one without misperception). The best supported resolutions were misperception of sleep as wake, worry, and brief awakenings. A deficit in time estimation ability was not supported. We conclude by proposing several integrative solutions. PMID:21967449

Spectroscopy of muonic atoms and the proton radius puzzle

NASA Astrophysics Data System (ADS)

Antognini, Aldo

2017-09-01

We have measured several 2 S -2 P transitions in muonic hydrogen (μp), muonic deuterium (μd) and muonic helium ions (μ3He, μ4He). From muonic hydrogen we extracted a proton charge radius 20 times more precise than obtained from electron-proton scattering and hydrogen high-precision laser spectroscopy but at a variance of 7 σ from these values. This discrepancy is nowadays referred to as the proton radius puzzle. New insight has been recently provided by the first determination of the deuteron charge radius from laser spectroscopy of μd. The status of the proton charge radius puzzle including the new insights obtained by μd spectroscopy will be discussed. Work supported by the Swiss National Science Foundation SNF-200021-165854 and the ERC CoG. #725039.

The Incomplete Glutathione Puzzle: Just Guessing at Numbers and Figures?

PubMed Central

2017-01-01

Abstract Significance: Glutathione metabolism is comparable to a jigsaw puzzle with too many pieces. It is supposed to comprise (i) the reduction of disulfides, hydroperoxides, sulfenic acids, and nitrosothiols, (ii) the detoxification of aldehydes, xenobiotics, and heavy metals, and (iii) the synthesis of eicosanoids, steroids, and iron–sulfur clusters. In addition, glutathione affects oxidative protein folding and redox signaling. Here, I try to provide an overview on the relevance of glutathione-dependent pathways with an emphasis on quantitative data. Recent Advances: Intracellular redox measurements reveal that the cytosol, the nucleus, and mitochondria contain very little glutathione disulfide and that oxidative challenges are rapidly counterbalanced. Genetic approaches suggest that iron metabolism is the centerpiece of the glutathione puzzle in yeast. Furthermore, recent biochemical studies provide novel insights on glutathione transport processes and uncoupling mechanisms. Critical Issues: Which parts of the glutathione puzzle are most relevant? Does this explain the high intracellular concentrations of reduced glutathione? How can iron–sulfur cluster biogenesis, oxidative protein folding, or redox signaling occur at high glutathione concentrations? Answers to these questions not only seem to depend on the organism, cell type, and subcellular compartment but also on different ideologies among researchers. Future Directions: A rational approach to compare the relevance of glutathione-dependent pathways is to combine genetic and quantitative kinetic data. However, there are still many missing pieces and too little is known about the compartment-specific repertoire and concentration of numerous metabolites, substrates, enzymes, and transporters as well as rate constants and enzyme kinetic patterns. Gathering this information might require the development of novel tools but is crucial to address potential kinetic competitions and to decipher uncoupling

Geoscience Data Puzzles: Developing Students' Ability to Make Meaning from Data

NASA Astrophysics Data System (ADS)

Kastens, K. A.; Turrin, M.

2010-12-01

One of the most fundamental aspects of geoscience expertise is the ability to extract insights from observational earth data. Where an expert might see trends, patterns, processes, and candidate causal relationships, a novice could look at the same data representation and see dots, wiggles and blotches of color. The problem is compounded when the student was not personally involved in collecting the data or samples and thus has no experiential knowledge of the Earth setting that the data represent. In other words, the problem is especially severe when students tap into the vast archives of professionally-collected data that the geoscience community has worked so hard to make available for instructional use over the internet. Moreover, most high school and middle school teachers did not themselves learn Earth Science through analyzing data, and they may lack skills and/or confidence needed to scaffold students through the process of learning to interpret realistically-complex data sets. We have developed “Geoscience Data Puzzles” with the paired goals of (a) helping students learn about the earth from data, and (b) helping teachers learn to teach with data. Geoscience Data Puzzles are data-using activities that purposefully present a low barrier-to-entry for teachers and a high ratio of insight-to-effort for students. Each Puzzle uses authentic geoscience data, but the data are carefully pre-selected in order to illuminate a fundamental Earth process within tractable snippets of data. Every Puzzle offers "Aha" moments, when the connection between data and process comes clear in a rewarding burst of insight. Every Puzzle is accompanied by a Pedagogical Content Knowledge (PCK) guide, which explicates the chain of reasoning by which the puzzle-solver can use the evidence provided by the data to construct scientific claims. Four types of reasoning are stressed: spatial reasoning, in which students make inferences from observations about location, orientation, shape

RNA-Puzzles Round III: 3D RNA structure prediction of five riboswitches and one ribozyme

PubMed Central

Biesiada, Marcin; Boniecki, Michał J.; Chou, Fang-Chieh; Ferré-D'Amaré, Adrian R.; Das, Rhiju; Dunin-Horkawicz, Stanisław; Geniesse, Caleb; Kappel, Kalli; Kladwang, Wipapat; Krokhotin, Andrey; Łach, Grzegorz E.; Major, François; Mann, Thomas H.; Pachulska-Wieczorek, Katarzyna; Patel, Dinshaw J.; Piccirilli, Joseph A.; Popenda, Mariusz; Purzycka, Katarzyna J.; Ren, Aiming; Rice, Greggory M.; Santalucia, John; Tandon, Arpit; Trausch, Jeremiah J.; Wang, Jian; Weeks, Kevin M.; Williams, Benfeard; Xiao, Yi; Zhang, Dong; Zok, Tomasz

2017-01-01

RNA-Puzzles is a collective experiment in blind 3D RNA structure prediction. We report here a third round of RNA-Puzzles. Five puzzles, 4, 8, 12, 13, 14, all structures of riboswitch aptamers and puzzle 7, a ribozyme structure, are included in this round of the experiment. The riboswitch structures include biological binding sites for small molecules (S-adenosyl methionine, cyclic diadenosine monophosphate, 5-amino 4-imidazole carboxamide riboside 5′-triphosphate, glutamine) and proteins (YbxF), and one set describes large conformational changes between ligand-free and ligand-bound states. The Varkud satellite ribozyme is the most recently solved structure of a known large ribozyme. All puzzles have established biological functions and require structural understanding to appreciate their molecular mechanisms. Through the use of fast-track experimental data, including multidimensional chemical mapping, and accurate prediction of RNA secondary structure, a large portion of the contacts in 3D have been predicted correctly leading to similar topologies for the top ranking predictions. Template-based and homology-derived predictions could predict structures to particularly high accuracies. However, achieving biological insights from de novo prediction of RNA 3D structures still depends on the size and complexity of the RNA. Blind computational predictions of RNA structures already appear to provide useful structural information in many cases. Similar to the previous RNA-Puzzles Round II experiment, the prediction of non-Watson–Crick interactions and the observed high atomic clash scores reveal a notable need for an algorithm of improvement. All prediction models and assessment results are available at http://ahsoka.u-strasbg.fr/rnapuzzles/. PMID:28138060

Strategies and Correlates of Jigsaw Puzzle and Visuospatial Performance by Persons with Prader-Willi Syndrome

ERIC Educational Resources Information Center

Verdine, Brian N.; Troseth, Georgene L.; Hodapp, Robert M.; Dykens, Elisabeth M.

2008-01-01

Some individuals with Prader-Willi syndrome exhibit strengths in solving jigsaw puzzles. We compared visuospatial ability and jigsaw puzzle performance and strategies of 26 persons with Prader-Willi syndrome and 26 MA-matched typically developing controls. Individuals with Prader-Willi syndrome relied on piece shape. Those in the control group…

Using the Tower of Hanoi Puzzle to Infuse Your Mathematics Classroom with Computer Science Concepts

ERIC Educational Resources Information Center

Marzocchi, Alison S.

2016-01-01

This article suggests that logic puzzles, such as the well-known Tower of Hanoi puzzle, can be used to introduce computer science concepts to mathematics students of all ages. Mathematics teachers introduce their students to computer science concepts that are enacted spontaneously and subconsciously throughout the solution to the Tower of Hanoi…

Multiple Quasi-Equilibria of the ITCZ and the Origin of Monsoon Onset. Part 2; Rotational ITCZ Attractors

NASA Technical Reports Server (NTRS)

Chao, Winston C.; Chen, Baode; Einaudi, Franco (Technical Monitor)

2000-01-01

Chao's numerical and theoretical work on multiple quasi-equilibria of the intertropical convergence zone (ITCZ) and the origin of monsoon onset is extended to solve two additional puzzles. One is the highly nonlinear dependence on latitude of the "force" acting on the ITCZ due to earth's rotation, which makes the multiple quasi-equilibria of the ITCZ and monsoon onset possible. The other is the dramatic difference in such dependence when different cumulus parameterization schemes are used in a model. Such a difference can lead to a switch between a single ITCZ at the equator and a double ITCZ, when a different cumulus parameterization scheme is used. Sometimes one of the double ITCZ can diminish and only the other remain, but still this can mean different latitudinal locations for the single ITCZ. A single idea based on two off-equator attractors for the ITCZ, due to earth's rotation and symmetric with respect to the equator, and the dependence of the strength and size of these attractors on the cumulus parameterization scheme solves both puzzles. The origin of these rotational attractors, explained in Part I, is further discussed. The "force" acting on the ITCZ due to earth's rotation is the sum of the "forces" of the two attractors. Each attractor exerts on the ITCZ a "force" of simple shape in latitude; but the sum gives a shape highly varying in latitude. Also the strength and the domain of influence of each attractor vary, when change is made in the cumulus parameterization. This gives rise to the high sensitivity of the "force" shape to cumulus parameterization. Numerical results, of experiments using Goddard's GEOS general circulation model, supporting this idea are presented. It is also found that the model results are sensitive to changes outside of the cumulus parameterization. The significance of this study to El Nino forecast and to tropical forecast in general is discussed.

Puzzle maker in SmB6: accompany-type valence fluctuation state

NASA Astrophysics Data System (ADS)

Wu, Qi; Sun, Liling

2017-11-01

In recent years, studying the Kondo insulator SmB6, a strongly correlated electron material that has been puzzling the community for decades, has again become an attractive topic due to the discovery of its unusual metallic surface state coexisting with the bulk insulating state. Many efforts have been made to understand the microphysics in SmB6, but some puzzles that have been hotly debated and argued have not been solved. In this article, based on the latest progress made in our high-pressure studies on SmB6 and the accumulating results reported by other groups, we propose a notion named the ‘accompany-type valence fluctuation state’, which possibly coexists with the bulk Kondo insulating ground state of SmB6. We expect that this notion could be taken as a common starting point for understanding in a unified way most of the low-temperature phenomena observed by different experimental investigations on SmB6, thus promoting the deciphering of the puzzles. We also expect that this notion could attract rigorous theoretical interpretation and further experimental investigation, or stimulate better thinking on the physics in SmB6.

Using the Tower of Hanoi puzzle to infuse your mathematics classroom with computer science concepts

NASA Astrophysics Data System (ADS)

Marzocchi, Alison S.

2016-07-01

This article suggests that logic puzzles, such as the well-known Tower of Hanoi puzzle, can be used to introduce computer science concepts to mathematics students of all ages. Mathematics teachers introduce their students to computer science concepts that are enacted spontaneously and subconsciously throughout the solution to the Tower of Hanoi puzzle. These concepts include, but are not limited to, conditionals, iteration, and recursion. Lessons, such as the one proposed in this article, are easily implementable in mathematics classrooms and extracurricular programmes as they are good candidates for 'drop in' lessons that do not need to fit into any particular place in the typical curriculum sequence. As an example for readers, the author describes how she used the puzzle in her own Number Sense and Logic course during the federally funded Upward Bound Math/Science summer programme for college-intending low-income high school students. The article explains each computer science term with real-life and mathematical examples, applies each term to the Tower of Hanoi puzzle solution, and describes how students connected the terms to their own solutions of the puzzle. It is timely and important to expose mathematics students to computer science concepts. Given the rate at which technology is currently advancing, and our increased dependence on technology in our daily lives, it has become more important than ever for children to be exposed to computer science. Yet, despite the importance of exposing today's children to computer science, many children are not given adequate opportunity to learn computer science in schools. In the United States, for example, most students finish high school without ever taking a computing course. Mathematics lessons, such as the one described in this article, can help to make computer science more accessible to students who may have otherwise had little opportunity to be introduced to these increasingly important concepts.

A Heuristic Bioinspired for 8-Piece Puzzle

NASA Astrophysics Data System (ADS)

Machado, M. O.; Fabres, P. A.; Melo, J. C. L.

2017-10-01

This paper investigates a mathematical model inspired by nature, and presents a Meta-Heuristic that is efficient in improving the performance of an informed search, when using strategy A * using a General Search Tree as data structure. The work hypothesis suggests that the investigated meta-heuristic is optimal in nature and may be promising in minimizing the computational resources required by an objective-based agent in solving high computational complexity problems (n-part puzzle) as well as In the optimization of objective functions for local search agents. The objective of this work is to describe qualitatively the characteristics and properties of the mathematical model investigated, correlating the main concepts of the A * function with the significant variables of the metaheuristic used. The article shows that the amount of memory required to perform this search when using the metaheuristic is less than using the A * function to evaluate the nodes of a general search tree for the eight-piece puzzle. It is concluded that the meta-heuristic must be parameterized according to the chosen heuristic and the level of the tree that contains the possible solutions to the chosen problem.

A solution to B → ππ puzzle and B → KK

NASA Astrophysics Data System (ADS)

Baek, Seungwon

2008-01-01

The large ratio of color-suppressed tree amplitude to color-allowed one in B → ππ decays is difficult to understand within the Standard Model, which is known as the " B → ππ puzzle". The two tree diagrams contain the up- and charm-quark component of penguin amplitude, Puc, which cannot be separated by measuring B → ππ decays alone. We show that the measurements of the branching ratio and direct CP asymmetry of B+ →K+K0 bar decay enable one to disentangle the Puc with two-fold ambiguity. One of the two degenerate solutions of the Puc can solve the B → ππ puzzle by giving | C / T | ∼ 0.3 which is consistent with the expectation in the Standard Model. We also show that the two solutions can be discriminated by the measurement of the indirect CP asymmetry of B0 →K0K0 bar. We point out that the corresponding puzzle in B → πK decays is not solved in this way.

A Geometric Puzzle That Leads To Fibonacci Sequences.

ERIC Educational Resources Information Center

Rulf, Benjamin

1998-01-01

Illustrates how mathematicians work and do mathematical research through the use of a puzzle. Demonstrates how general rules, then theorems develop from special cases. This approach may be used as a research project in high school classrooms or math club settings with the teacher helping to formulate questions, set goals, and avoid becoming…

Jouer avec les Mots Fleches (Playing with Word Puzzles).

ERIC Educational Resources Information Center

Beltran, Roger Rodriguez

1996-01-01

Focuses on how to work crossword puzzles, such as those published in magazines or specialized publications. The article emphasizes the importance of the dictionary for this activity, which can be a pleasant cultural exercise in vocabulary development and spelling instruction. (Author/CK)

Jigsaw puzzle metasurface for multiple functions: polarization conversion, anomalous reflection and diffusion.

PubMed

Zhao, Yi; Cao, Xiangyu; Gao, Jun; Liu, Xiao; Li, Sijia

2016-05-16

We demonstrate a simple reconfigurable metasurface with multiple functions. Anisotropic tiles are investigated and manufactured as fundamental elements. Then, the tiles are combined in a certain sequence to construct a metasurface. Each of the tiles can be adjusted independently which is like a jigsaw puzzle and the whole metasurface can achieve diverse functions by different layouts. For demonstration purposes, we realize polarization conversion, anomalous reflection and diffusion by a jigsaw puzzle metasurface with 6 × 6 pieces of anisotropic tile. Simulated and measured results prove that our method offers a simple and effective strategy for metasurface design.

High-mass twins & resolution of the reconfinement, masquerade and hyperon puzzles of compact star interiors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blaschke, David; Instytut Fizyki Teoretycznej, Uniwersytet Wroclawski, 50-204 Wroclaw; Alvarez-Castillo, David E.

2016-01-22

We aim at contributing to the resolution of three of the fundamental puzzles related to the still unsolved problem of the structure of the dense core of compact stars (CS): (i) the hyperon puzzle: how to reconcile pulsar masses of 2 M{sub ⊙} with the hyperon softening of the equation of state (EoS); (ii) the masquerade problem: modern EoS for cold, high density hadronic and quark matter are almost identical; and (iii) the reconfinement puzzle: what to do when after a deconfinement transition the hadronic EoS becomes favorable again? We show that taking into account the compositeness of baryons (bymore » excluded volume and/or quark Pauli blocking) on the hadronic side and confining and stiffening effects on the quark matter side results in an early phase transition to quark matter with sufficient stiffening at high densities which removes all three present-day puzzles of CS interiors. Moreover, in this new class of EoS for hybrid CS falls the interesting case of a strong first order phase transition which results in the observable high mass twin star phenomenon, an astrophysical observation of a critical endpoint in the QCD phase diagram.« less

Toward a virtual reconstruction of an antique three-dimensional marble puzzle

NASA Astrophysics Data System (ADS)

Benamar, Fatima Zahra; Fauvet, Eric; Hostein, Antony; Laligant, Olivier; Truchetet, Frederic

2017-01-01

The reconstruction of broken objects is an important field of research for many applications, such as art restoration, surgery, forensics, and solving puzzles. In archaeology, the reconstruction of broken artifacts is a very time-consuming task due to the handling of fractured objects, which are generally fragile. However, it can now be supported by three-dimensional (3-D) data acquisition devices and computer processing. Those techniques are very useful in this domain because they allow the remote handling of very accurate models of fragile parts, they permit the extensive testing of reconstruction solutions, and they provide access to the parts for the entire research community. An interesting problem has recently been proposed by archaeologists in the form of a huge puzzle composed of a thousand fragments of Pentelic marble of different sizes found in Autun (France), and all attempts to reconstruct the puzzle during the last two centuries have failed. Archaeologists are sure that some fragments are missing and that some of the ones we have come from different slabs. We propose an inexpensive transportable system for 3-D acquisition setup and a 3-D reconstruction method that is applied to this Roman inscription but is also relevant to other applications.

An Easy & Fun Way to Teach about How Science "Works": Popularizing Haack's Crossword-Puzzle Analogy

ERIC Educational Resources Information Center

Pavlova, Iglika V.; Lewis, Kayla C.

2013-01-01

Science is a complex process, and we must not teach our students overly simplified versions of "the" scientific method. We propose that students can uncover the complex realities of scientific thinking by exploring the similarities and differences between solving the familiar crossword puzzles and scientific "puzzles."…

Solving the 56Ni Puzzle of Magnetar-powered Broad-lined Type IC Supernovae

NASA Astrophysics Data System (ADS)

Wang, Ling-Jun; Han, Yan-Hui; Xu, Dong; Wang, Shan-Qin; Dai, Zi-Gao; Wu, Xue-Feng; Wei, Jian-Yan

2016-11-01

Broad-lined Type Ic supernovae (SNe Ic-BL) are of great importance because their association with long-duration gamma-ray bursts (LGRBs) holds the key to deciphering the central engine of LGRBs, which refrains from being unveiled despite decades of investigation. Among the two popularly hypothesized types of central engine, I.e., black holes and strongly magnetized neutron stars (magnetars), there is mounting evidence that the central engine of GRB-associated SNe (GRB-SNe) is rapidly rotating magnetars. Theoretical analysis also suggests that magnetars could be the central engine of SNe Ic-BL. What puzzled the researchers is the fact that light-curve modeling indicates that as much as 0.2{--}0.5 {M}⊙ of 56Ni was synthesized during the explosion of the SNe Ic-BL, which is unfortunately in direct conflict with current state-of-the-art understanding of magnetar-powered 56Ni synthesis. Here we propose a dynamic model of magnetar-powered SNe to take into account the acceleration of the ejecta by the magnetar, as well as the thermalization of the injected energy. Assuming that the SN kinetic energy comes exclusively from the magnetar acceleration, we find that although a major fraction of the rotational energy of the magnetar is to accelerate the SN ejecta, a tiny fraction of this energy deposited as thermal energy of the ejecta is enough to reduce the needed 56Ni to 0.06 M ⊙ for both SN 1997ef and SN 2007ru. We therefore suggest that magnetars could power SNe Ic-BL in aspects both of energetics and of 56Ni synthesis.

A puzzle assembly strategy for fabrication of large engineered cartilage tissue constructs.

PubMed

Nover, Adam B; Jones, Brian K; Yu, William T; Donovan, Daniel S; Podolnick, Jeremy D; Cook, James L; Ateshian, Gerard A; Hung, Clark T

2016-03-21

Engineering of large articular cartilage tissue constructs remains a challenge as tissue growth is limited by nutrient diffusion. Here, a novel strategy is investigated, generating large constructs through the assembly of individually cultured, interlocking, smaller puzzle-shaped subunits. These constructs can be engineered consistently with more desirable mechanical and biochemical properties than larger constructs (~4-fold greater Young׳s modulus). A failure testing technique was developed to evaluate the physiologic functionality of constructs, which were cultured as individual subunits for 28 days, then assembled and cultured for an additional 21-35 days. Assembled puzzle constructs withstood large deformations (40-50% compressive strain) prior to failure. Their ability to withstand physiologic loads may be enhanced by increases in subunit strength and assembled culture time. A nude mouse model was utilized to show biocompatibility and fusion of assembled puzzle pieces in vivo. Overall, the technique offers a novel, effective approach to scaling up engineered tissues and may be combined with other techniques and/or applied to the engineering of other tissues. Future studies will aim to optimize this system in an effort to engineer and integrate robust subunits to fill large defects. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Puzzle Assembly Strategy for Fabrication of Large Engineered Cartilage Tissue Constructs

PubMed Central

Nover, Adam B.; Jones, Brian K.; Yu, William T.; Donovan, Daniel S.; Podolnick, Jeremy D.; Cook, James L.; Ateshian, Gerard A.; Hung, Clark T.

2016-01-01

Engineering of large articular cartilage tissue constructs remains a challenge as tissue growth is limited by nutrient diffusion. Here, a novel strategy is investigated, generating large constructs through the assembly of individually cultured, interlocking, smaller puzzle-shaped subunits. These constructs can be engineered consistently with more desirable mechanical and biochemical properties than larger constructs (~4-fold greater Young's modulus). A failure testing technique was developed to evaluate the physiologic functionality of constructs, which were cultured as individual subunits for 28 days, then assembled and cultured for an additional 21-35 days. Assembled puzzle constructs withstood large deformations (40-50% compressive strain) prior to failure. Their ability to withstand physiologic loads may be enhanced by increases in subunit strength and assembled culture time. A nude mouse model was utilized to show biocompatibility and fusion of assembled puzzle pieces in vivo. Overall, the technique offers a novel, effective approach to scaling up engineered tissues and may be combined with other techniques and/or applied to the engineering of other tissues. Future studies will aim to optimize this system in an effort to engineer and integrate robust subunits to fill large defects. PMID:26895780

Crossword Puzzles as a Learning Tool for Vocabulary Development

ERIC Educational Resources Information Center

Orawiwatnakul, Wiwat

2013-01-01

Introduction: Since vocabulary is a key basis on which reading achievement depends, various vocabulary acquisition techniques have become pivotal. Among the many teaching approaches, traditional or otherwise, the use of crossword puzzles seems to offer potential and a solution for the problem of learning vocabulary. Method: This study was…

Action and puzzle video games prime different speed/accuracy tradeoffs.

PubMed

Nelson, Rolf A; Strachan, Ian

2009-01-01

To understand the way in which video-game play affects subsequent perception and cognitive strategy, two experiments were performed in which participants played either a fast-action game or a puzzle-solving game. Before and after video-game play, participants performed a task in which both speed and accuracy were emphasized. In experiment 1 participants engaged in a location task in which they clicked a mouse on the spot where a target had appeared, and in experiment 2 they were asked to judge which of four shapes was most similar to a target shape. In both experiments, participants were much faster but less accurate after playing the action game, while they were slower but more accurate after playing the puzzle game. Results are discussed in terms of a taxonomy of video games by their cognitive and perceptual demands.

Sequential Monte Carlo for Maximum Weight Subgraphs with Application to Solving Image Jigsaw Puzzles.

PubMed

Adluru, Nagesh; Yang, Xingwei; Latecki, Longin Jan

2015-05-01

We consider a problem of finding maximum weight subgraphs (MWS) that satisfy hard constraints in a weighted graph. The constraints specify the graph nodes that must belong to the solution as well as mutual exclusions of graph nodes, i.e., pairs of nodes that cannot belong to the same solution. Our main contribution is a novel inference approach for solving this problem in a sequential monte carlo (SMC) sampling framework. Usually in an SMC framework there is a natural ordering of the states of the samples. The order typically depends on observations about the states or on the annealing setup used. In many applications (e.g., image jigsaw puzzle problems), all observations (e.g., puzzle pieces) are given at once and it is hard to define a natural ordering. Therefore, we relax the assumption of having ordered observations about states and propose a novel SMC algorithm for obtaining maximum a posteriori estimate of a high-dimensional posterior distribution. This is achieved by exploring different orders of states and selecting the most informative permutations in each step of the sampling. Our experimental results demonstrate that the proposed inference framework significantly outperforms loopy belief propagation in solving the image jigsaw puzzle problem. In particular, our inference quadruples the accuracy of the puzzle assembly compared to that of loopy belief propagation.

Sequential Monte Carlo for Maximum Weight Subgraphs with Application to Solving Image Jigsaw Puzzles

PubMed Central

Adluru, Nagesh; Yang, Xingwei; Latecki, Longin Jan

2015-01-01

We consider a problem of finding maximum weight subgraphs (MWS) that satisfy hard constraints in a weighted graph. The constraints specify the graph nodes that must belong to the solution as well as mutual exclusions of graph nodes, i.e., pairs of nodes that cannot belong to the same solution. Our main contribution is a novel inference approach for solving this problem in a sequential monte carlo (SMC) sampling framework. Usually in an SMC framework there is a natural ordering of the states of the samples. The order typically depends on observations about the states or on the annealing setup used. In many applications (e.g., image jigsaw puzzle problems), all observations (e.g., puzzle pieces) are given at once and it is hard to define a natural ordering. Therefore, we relax the assumption of having ordered observations about states and propose a novel SMC algorithm for obtaining maximum a posteriori estimate of a high-dimensional posterior distribution. This is achieved by exploring different orders of states and selecting the most informative permutations in each step of the sampling. Our experimental results demonstrate that the proposed inference framework significantly outperforms loopy belief propagation in solving the image jigsaw puzzle problem. In particular, our inference quadruples the accuracy of the puzzle assembly compared to that of loopy belief propagation. PMID:26052182

Manchester's Magiscope: An Interesting Optics Puzzle

NASA Astrophysics Data System (ADS)

Lancor, Rachael; Lancor, Brian

2017-02-01

The Magiscope was an attraction at Manchester's department store in Madison, WI, in 1939 that allowed children to peek into Santa's workshop (as shown in Fig. 1). The "magiscope" was a telescope-like device that gave children the illusion they were looking at a distant Santa, when in fact they were looking at a fabricated workshop on an upper level of the department store. In this article, we describe how we used the puzzle of the magiscope as a final assessment for our optics unit in an introductory physics course.

The Puzzling Ophiuchus Stream

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2016-01-01

Dwarf galaxies or globular clusters orbiting the Milky Way can be pulled apart by tidal forces, leaving behind a trail of stars known as a stellar stream. One such trail, the Ophiuchus stream, has posed a serious dynamical puzzle since its discovery. But a recent study has identified four stars that might help resolve this streams mystery.Conflicting TimescalesThe stellar stream Ophiuchus was discovered around our galaxy in 2014. Based on its length, which appears to be 1.6 kpc, we can calculate the time that has passed since its progenitor was disrupted and the stream was created: ~250 Myr. But the stars within it are ~12 Gyr old, and the stream orbits the galaxy with a period of ~350 Myr.Given these numbers, we can assume that Ophiuchuss progenitor completed many orbits of the Milky Way in its lifetime. So why would it only have been disrupted 250 million years ago?Fanning StreamLed by Branimir Sesar (Max Planck Institute for Astronomy), a team of scientists has proposed an idea that might help solve this puzzle. If the Ophiuchus stellar stream is on a chaotic orbit common in triaxial potentials, which the Milky Ways may be then the stream ends can fan out, with stars spreading in position and velocity.The fanned part of the stream, however, would be difficult to detect because of its low surface brightness. As a result, the Ophiuchus stellar stream could actually be longer than originally measured, implying that it was disrupted longer ago than was believed.Search for Fan StarsTo test this idea, Sesar and collaborators performed a search around the ends of the stream, looking for stars thatare of the right type to match the stream,are at the predicted distance of the stream,are located near the stream ends, andhave velocities that match the stream and dont match the background halo stars.Histogram of the heliocentric velocities of the 43 target stars. Six stars have velocities matching the stream velocity. Two of these are located in the main stream; the other

Jigsaw: Because Reading Your Math Book Shouldn't Be a Puzzle.

ERIC Educational Resources Information Center

Draper, Roni Jo

1997-01-01

Describes a jigsaw puzzle activity, a two-part cooperative learning activity useful at any level of mathematics instruction, intended to teach students to become "strategic readers" of their mathematics textbooks. (SR)

Children's Task Engagement during Challenging Puzzle Tasks

ERIC Educational Resources Information Center

Wang, Feihong; Algina, James; Snyder, Patricia; Cox, Martha

2017-01-01

We examined children's task engagement during a challenging puzzle task in the presence of their primary caregivers by using a representative sample of rural children from six high-poverty counties across two states. Weighted longitudinal confirmatory factor analysis and structural equation modeling were used to identify a task engagement factor…

What Is the Difference between a Puzzle and a Maths Question?

ERIC Educational Resources Information Center

Eastaway, Robert

1997-01-01

Discusses the differences between puzzles and mathematics questions. Argues that mathematics teachers need to be thoroughly grounded in the well-documented recreational side of mathematics and be encouraged to use it. (JRH)

The RPA Atomization Energy Puzzle.

PubMed

Ruzsinszky, Adrienn; Perdew, John P; Csonka, Gábor I

2010-01-12

There is current interest in the random phase approximation (RPA), a "fifth-rung" density functional for the exchange-correlation energy. RPA has full exact exchange and constructs the correlation with the help of the unoccupied Kohn-Sham orbitals. In many cases (uniform electron gas, jellium surface, and free atom), the correction to RPA is a short-ranged effect that is captured by a local spin density approximation (LSDA) or a generalized gradient approximation (GGA). Nonempirical density functionals for the correction to RPA were constructed earlier at the LSDA and GGA levels (RPA+), but they are constructed here at the fully nonlocal level (RPA++), using the van der Waals density functional (vdW-DF) of Langreth, Lundqvist, and collaborators. While they make important and helpful corrections to RPA total and ionization energies of free atoms, they correct the RPA atomization energies of molecules by only about 1 kcal/mol. Thus, it is puzzling that RPA atomization energies are, on average, about 10 kcal/mol lower than those of accurate values from experiment. We find here that a hybrid of 50% Perdew-Burke-Ernzerhof GGA with 50% RPA+ yields atomization energies much more accurate than either one does alone. This suggests a solution to the puzzle: While the proper correction to RPA is short-ranged in some systems, its contribution to the correlation hole can spread out in a molecule with multiple atomic centers, canceling part of the spread of the exact exchange hole (more so than in RPA or RPA+), making the true exchange-correlation hole more localized than in RPA or RPA+. This effect is not captured even by the vdW-DF nonlocality, but it requires the different kind of full nonlocality present in a hybrid functional.

Exfoliation syndrome: assembling the puzzle pieces.

PubMed

Pasquale, Louis R; Borrás, Terete; Fingert, John H; Wiggs, Janey L; Ritch, Robert

2016-09-01

To summarize various topics and the cutting edge approaches to refine XFS pathogenesis that were discussed at the 21st annual Glaucoma Foundation Think Tank meeting in New York City, Sept. 19-20, 2014. The highlights of three categories of talks on cutting edge research in the field were summarized. Exfoliation syndrome (XFS) is a systemic disorder with a substantial ocular burden, including high rates of cataract, cataract surgery complications, glaucoma and retinal vein occlusion. New information about XFS is akin to puzzle pieces that do not quite join together to reveal a clear picture regarding how exfoliation material (XFM) forms. Meeting participants concluded that it is unclear how the mild homocysteinemia seen in XFS might contribute to the disarrayed extracellular aggregates characteristic of this syndrome. Lysyl oxidase-like 1 (LOXL1) variants are unequivocally genetic risk factors for XFS but exactly how these variants contribute to the assembly of exfoliation material (XFM) remains unclear. Variants in a new genomic region, CACNA1A associated with XFS, may alter calcium concentrations at the cell surface and facilitate XFM formation but much more work is needed before we can place this new finding in proper context. It is hoped that various animal model and ex vivo systems will emerge that will allow for proper assembly of the puzzle pieces into a coherent picture of XFS pathogenesis. A clear understanding of XFS pathogenesis may lead to 'upstream solutions' to reduce the ocular morbidity produced by XFS. © 2015 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

To Txt or Not to Txt: That's the Puzzle

ERIC Educational Resources Information Center

Goh, Tiong-Thye; Hooper, Val

2007-01-01

This paper describes the potential use of a mobile phone Short Message Service (SMS) crossword puzzle system to promote interaction through learning activities in a large classroom environment. While personal response systems (PRS) have been used in the classroom environment to foster interaction, it is not an ideal tool with respect to cost and…

Utility of Self-Made Crossword Puzzles as an Active Learning Method to Study Biochemistry in Undergraduate Education

ERIC Educational Resources Information Center

Coticone, Sulekha Rao

2013-01-01

To incorporate an active learning component in a one-semester biochemistry course, students were asked to create crossword puzzles using key concepts. Student observations on the use of self-made crossword puzzles as an active-learning instructional tool were collected using a 5-point Likert survey at the end of the semester. A majority of the…

Realistic simulations of the coupling between the protomotive force and the mechanical rotation of the F0-ATPase

PubMed Central

Mukherjee, Shayantani; Warshel, Arieh

2012-01-01

The molecular origin of the action of the F0 proton gradient-driven rotor presents a major puzzle despite significant structural advances. Although important conceptual models have provided guidelines of how such systems should work, it has been challenging to generate a structure-based molecular model using physical principles that will consistently lead to the unidirectional proton-driven rotational motion during ATP synthesis. This work uses a coarse-grained (CG) model to simulate the energetics of the F0-ATPase system in the combined space defined by the rotational coordinate and the proton transport (PTR) from the periplasmic side (P) to the cytoplasmic side (N). The model establishes the molecular origin of the rotation, showing that this effect is due to asymmetry in the energetics of the proton path rather than only the asymmetry of the interaction of the Asp on the c-ring helices and Arg on the subunit-a. The simulation provides a clear conceptual background for further exploration of the electrostatic basis of proton-driven mechanochemical systems. PMID:22927379

First Detection of a Strong Magnetic Field on a Bursty Brown Dwarf: Puzzle Solved

NASA Astrophysics Data System (ADS)

Berdyugina, S. V.; Harrington, D. M.; Kuzmychov, O.; Kuhn, J. R.; Hallinan, G.; Kowalski, A. F.; Hawley, S. L.

2017-09-01

We report the first direct detection of a strong, 5 kG magnetic field on the surface of an active brown dwarf. LSR J1835+3259 is an M8.5 dwarf exhibiting transient radio and optical emission bursts modulated by fast rotation. We have detected the surface magnetic field as circularly polarized signatures in the 819 nm sodium lines when an active emission region faced the Earth. Modeling Stokes profiles of these lines reveals the effective temperature of 2800 K and log gravity acceleration of 4.5. These parameters place LSR J1835+3259 on evolutionary tracks as a young brown dwarf with the mass of 55+/- 4{M}{{J}} and age of 22 ± 4 Myr. Its magnetic field is at least 5.1 kG and covers at least 11% of the visible hemisphere. The active region topology recovered using line profile inversions comprises hot plasma loops with a vertical stratification of optical and radio emission sources. These loops rotate with the dwarf in and out of view causing periodic emission bursts. The magnetic field is detected at the base of the loops. This is the first time that we can quantitatively associate brown dwarf non-thermal bursts with a strong, 5 kG surface magnetic field and solve the puzzle of their driving mechanism. This is also the coolest known dwarf with such a strong surface magnetic field. The young age of LSR J1835+3259 implies that it may still maintain a disk, which may facilitate bursts via magnetospheric accretion, like in higher-mass T Tau-type stars. Our results pave a path toward magnetic studies of brown dwarfs and hot Jupiters.

Rotation and Morphology of Comet 252P/LINEAR

NASA Astrophysics Data System (ADS)

Woodney, Laura; Schambeau, Charles A.; Fernandez, Yanga R.

2017-10-01

Comet 252P/LINEAR had an incredibly close approach early in 2016 - minimum distance 0.036 AU on March 21 - that allowed detailed investigation of its behavior. Analysis of observations of the morphology of 252P have resulted in several possible rotational periods. Knight and Schleicher found that repetition of features in narrowband imaging from April 2016 indicated a period of 7.35 +/- 0.05 hr [1]. HST broadband data obtained by Li et al. in March and April partially fit the 7.35 hr period, but found 5.5 hr was a better fit for the April 4 r’ band data [2]. Given this discrepancy, additional observations may shed light on the true rotation state, and we present here the pieces of the puzzle obtained by our group.We observed 252P with the Kitt Peak National Observatory WIYN 0.9 m telescope on 7 nights: May 2 - 5 and June 6,8,9, 2016 using a Harris R filter. An oscillating jet is clearly visible in our data. While there is insufficient phase coverage to determine a best fit period from our data alone, we will present how our observations of the morphology fit the two proposed periods.[1] Knight, M.M and D.G. Schleicher. AAS, DPS Meeting #48, id.207.02, 2016 [2] Li, J.-Y. et al. AAS, DPS Meeting #48, id. 206.03, 2016.

The puzzling unsolved mysteries of liquid water: Some recent progress

NASA Astrophysics Data System (ADS)

Stanley, H. E.; Kumar, P.; Xu, L.; Yan, Z.; Mazza, M. G.; Buldyrev, S. V.; Chen, S.-H.; Mallamace, F.

2007-12-01

Water is perhaps the most ubiquitous, and the most essential, of any molecule on earth. Indeed, it defies the imagination of even the most creative science fiction writer to picture what life would be like without water. Despite decades of research, however, water's puzzling properties are not understood and 63 anomalies that distinguish water from other liquids remain unsolved. We introduce some of these unsolved mysteries, and demonstrate recent progress in solving them. We present evidence from experiments and computer simulations supporting the hypothesis that water displays a special transition point (which is not unlike the “tipping point” immortalized by Malcolm Gladwell). The general idea is that when the liquid is near this “tipping point,” it suddenly separates into two distinct liquid phases. This concept of a new critical point is finding application to other liquids as well as water, such as silicon and silica. We also discuss related puzzles, such as the mysterious behavior of water near a protein.

The γ Dor stars as revealed by Kepler: A key to reveal deep-layer rotation in A and F stars

NASA Astrophysics Data System (ADS)

Salmon, S. J. A. J.; Ouazzani, R.-M.; Antoci, V.; Bedding, T. R.; Murphy, S. J.

2017-09-01

The γ Dor pulsating stars present high-order gravity modes, which make them important targets in the intermediate-and low-mass main-sequence region of the Hertzsprung-Russell diagram. Whilst we have only access to rotation in the envelope of the Sun, the g modes of γ Dor stars can in principle deliver us constraints on the inner layers. With the puzzling discovery of unexpectedly low rotation rates in the core of red giants, the γ Dor stars appear now as unique targets to explore internal angular momentum transport in the progenitors of red giants. Yet, the γ Dor pulsations remain hard to detect from the ground for their periods are close to 1 day. While the CoRoT space mission first revealed intriguing frequency spectra, the almost uninterrupted 4-year photometry from the Kepler mission eventually shed a new light on them. It revealed regularities in the spectra, expected to bear signature of physical processes, including rotation, in the shear layers close to the convective core. We present here the first results of our effort to derive exploitable seismic diagnosis for mid- to fast rotators among γ Dor stars. We confirm their potential to explore the rotation history of this early phase of stellar evolution.

Tiny bubbles challenge giant turbines: Three Gorges puzzle.

PubMed

Li, Shengcai

2015-10-06

Since the birth of the first prototype of the modern reaction turbine, cavitation as conjectured by Euler in 1754 always presents as a challenge. Following his theory, the evolution of modern reaction (Francis and Kaplan) turbines has been completed by adding the final piece of the element 'draft-tube' that enables turbines to explore water energy at efficiencies of almost 100%. However, during the last two and a half centuries, with increasing unit capacity and specific speed, the problem of cavitation has been manifested and complicated by the draft-tube surges rather than being solved. Particularly, during the last 20 years, the fierce competition in the international market for extremely large turbines with compact design has encouraged the development of giant Francis turbines of 700-1000 MW. The first group (24 units) of such giant turbines of 700 MW each was installed in the Three Gorges project. Immediately after commission, a strange erosion phenomenon appeared on the guide vane of the machines that has puzzled professionals. From a multi-disciplinary analysis, this Three Gorges puzzle could reflect an unknown type of cavitation inception presumably triggered by turbulence production from the boundary-layer streak transitional process. It thus presents a fresh challenge not only to this old turbine industry, but also to the fundamental sciences.

Solar Twins and the Barium Puzzle

NASA Astrophysics Data System (ADS)

Reddy, Arumalla B. S.; Lambert, David L.

2017-08-01

Several abundance analyses of Galactic open clusters (OCs) have shown a tendency for Ba but not for other heavy elements (La-Sm) to increase sharply with decreasing age such that Ba was claimed to reach [Ba/Fe] ≃ +0.6 in the youngest clusters (ages < 100 Myr) rising from [Ba/Fe] = 0.00 dex in solar-age clusters. Within the formulation of the s-process, the difficulty to replicate higher Ba abundance and normal La-Sm abundances in young clusters is known as the barium puzzle. Here, we investigate the barium puzzle using extremely high-resolution and high signal-to-noise spectra of 24 solar twins and measured the heavy elements Ba, La, Ce, Nd, and Sm with a precision of 0.03 dex. We demonstrate that the enhanced Ba II relative to La-Sm seen among solar twins, stellar associations, and OCs at young ages (<100 Myr) is unrelated to aspects of stellar nucleosynthesis but has resulted from overestimation of Ba by standard methods of LTE abundance analysis in which the microturbulence derived from the Fe lines formed deep in the photosphere is insufficient to represent the true line broadening imposed on Ba II lines by the upper photospheric layers from where the Ba II lines emerge. Because the young stars have relatively active photospheres, Ba overabundances most likely result from the adoption of a too low value of microturbulence in the spectrum synthesis of the strong Ba II lines but the change of microturbulence in the upper photosphere has only a minor affect on La-Sm abundances measured from the weak lines.

Solar Twins and the Barium Puzzle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reddy, Arumalla B. S.; Lambert, David L., E-mail: bala@astro.as.utexas.edu

Several abundance analyses of Galactic open clusters (OCs) have shown a tendency for Ba but not for other heavy elements (La−Sm) to increase sharply with decreasing age such that Ba was claimed to reach [Ba/Fe] ≃ +0.6 in the youngest clusters (ages < 100 Myr) rising from [Ba/Fe] = 0.00 dex in solar-age clusters. Within the formulation of the s -process, the difficulty to replicate higher Ba abundance and normal La−Sm abundances in young clusters is known as the barium puzzle. Here, we investigate the barium puzzle using extremely high-resolution and high signal-to-noise spectra of 24 solar twins and measuredmore » the heavy elements Ba, La, Ce, Nd, and Sm with a precision of 0.03 dex. We demonstrate that the enhanced Ba ii relative to La−Sm seen among solar twins, stellar associations, and OCs at young ages (<100 Myr) is unrelated to aspects of stellar nucleosynthesis but has resulted from overestimation of Ba by standard methods of LTE abundance analysis in which the microturbulence derived from the Fe lines formed deep in the photosphere is insufficient to represent the true line broadening imposed on Ba ii lines by the upper photospheric layers from where the Ba ii lines emerge. Because the young stars have relatively active photospheres, Ba overabundances most likely result from the adoption of a too low value of microturbulence in the spectrum synthesis of the strong Ba ii lines but the change of microturbulence in the upper photosphere has only a minor affect on La−Sm abundances measured from the weak lines.« less

The Potential of Crossword Puzzles in Aiding English Language Learners

ERIC Educational Resources Information Center

Merkel, Warren

2016-01-01

In an academic environment, teachers utilize crossword puzzles to help students learn or remember terminology. Outside the classroom, typically in daily newspapers, crosswords aid in vocabulary development, used as a learning tool, a leisure activity, or both. However, both the content and the grid structure of the crosswords in these two…

A Play on Words: Using Cognitive Computing as a Basis for AI Solvers in Word Puzzles

NASA Astrophysics Data System (ADS)

Manzini, Thomas; Ellis, Simon; Hendler, James

2015-12-01

In this paper we offer a model, drawing inspiration from human cognition and based upon the pipeline developed for IBM's Watson, which solves clues in a type of word puzzle called syllacrostics. We briefly discuss its situation with respect to the greater field of artificial general intelligence (AGI) and how this process and model might be applied to other types of word puzzles. We present an overview of a system that has been developed to solve syllacrostics.

Emergence of Life on Earth: A Physicochemical Jigsaw Puzzle.

PubMed

Spitzer, Jan

2017-01-01

We review physicochemical factors and processes that describe how cellular life can emerge from prebiotic chemical matter; they are: (1) prebiotic Earth is a multicomponent and multiphase reservoir of chemical compounds, to which (2) Earth-Moon rotations deliver two kinds of regular cycling energies: diurnal electromagnetic radiation and seawater tides. (3) Emerging colloidal phases cyclically nucleate and agglomerate in seawater and consolidate as geochemical sediments in tidal zones, creating a matrix of microspaces. (4) Some microspaces persist and retain memory from past cycles, and others re-dissolve and re-disperse back into the Earth's chemical reservoir. (5) Proto-metabolites and proto-biopolymers coevolve with and within persisting microspaces, where (6) Macromolecular crowding and other non-covalent molecular forces govern the evolution of hydrophilic, hydrophobic, and charged molecular surfaces. (7) The matrices of microspaces evolve into proto-biofilms of progenotes with rudimentary but evolving replication, transcription, and translation, enclosed in unstable cell envelopes. (8) Stabilization of cell envelopes 'crystallizes' bacteria-like genetics and metabolism with low horizontal gene transfer-life 'as we know it.' These factors and processes constitute the 'working pieces' of the jigsaw puzzle of life's emergence. They extend the concept of progenotes as the first proto-cellular life, connected backward in time to the cycling chemistries of the Earth-Moon planetary system, and forward to the ancient cell cycle of first bacteria-like organisms. Supra-macromolecular models of 'compartments first' are preferred: they facilitate macromolecular crowding-a key abiotic/biotic transition toward living states. Evolutionary models of metabolism or genetics 'first' could not have evolved in unconfined and uncrowded environments because of the diffusional drift to disorder mandated by the second law of thermodynamics.

Applicability, Indispensability, and Underdetermination: Puzzling Over Wigner's `Unreasonable Effectiveness of Mathematics'

NASA Astrophysics Data System (ADS)

Gelfert, Axel

2014-05-01

In his influential 1960 paper `The Unreasonable Effectiveness of Mathematics in the Natural Sciences', Eugene P. Wigner raises the question of why something that was developed without concern for empirical facts—mathematics—should turn out to be so powerful in explaining facts about the natural world. Recent philosophy of science has developed `Wigner's puzzle' in two different directions: First, in relation to the supposed indispensability of mathematical facts to particular scientific explanations and, secondly, in connection with the idea that aesthetic criteria track theoretical desiderata such as empirical success. An important aspect of Wigner's article has, however, been overlooked in these debates: his worries about the underdetermination of physical theories by mathematical frameworks. The present paper argues that, by restoring this aspect of Wigner's argument to its proper place, Wigner's puzzle may become an instructive case study for the teaching of core issues in the philosophy of science and its history.

Alliteration in medicine: a puzzling profusion of p's

PubMed Central

Hayden, Gregory F

1999-01-01

Problem Puzzling, progressive profusion of alliterative “p's” in published papers. Purpose To depict this particular “p” predominance with pinpoint precision. Plan Periodic, painstaking perusal of periodicals by a professor of paediatrics. Proposal The “p” plethora is positively perplexing and potentially perturbing. Alliteration is a literary device consisting of repetition of the same starting sound in several words in a sentence.1 Consider, for example, Shakespeare's playful parody of alliteration in Peter Quince's prologue in A Midsummer Night's Dream: “Whereat with blade, with bloody blameful blade, He bravely broach'd his boiling bloody breast.” Alliteration has appeared frequently in the medical literature—for example: “Respiratory syncytial virus—from chimps with colds to conundrums and cures;”2 “The choreas: of faints, fevers, and families;”3 “Coronary artery stents—gauging, gorging, and gouging;”4 “Moschcowitz, multimers, and metalloprotease;”5 “Alagille syndrome: a nutritional niche for Notch;”6 “Theodor Billroth: success with sutures and strings.”7 Perusing the medical literature with alliteration in mind, I have become perplexed by a peculiar propensity for the letter “p” to be placed in prominent positions. Consider for a moment the alliterative content of the BMJ, a prestigious periodical also published in Pakistani, Polish, and Portuguese. Perhaps the prime example is a piece entitled “A potpourri of parasites in poetry and proverb,”8 but the journal has presented articles addressing such topics as paracetamol poisoning,9 practitioners' pressure to prescribe,10 physicians' partnerships with patients,11 partnerships for prevention in public playgrounds,12 and pregnancy outcomes which have been persistently poor.13 Other topics have included patients' priorities,14 the political process of puzzling out private versus public priorities,15 and the ponderous problem of whether the priorities in

The Retrofit Puzzle Extended: Optimal Fleet Owner Behavior over Multiple Time Periods

DOT National Transportation Integrated Search

2009-08-04

In "The Retrofit Puzzle: Optimal Fleet Owner Behavior in the Context of Diesel Retrofit Incentive Programs" (1) an integer program was developed to model profit-maximizing diesel fleet owner behavior when selecting pollution reduction retrofits. Flee...

Unraveling "Braid": Puzzle Games and Storytelling in the Imperative Mood

ERIC Educational Resources Information Center

Arnott, Luke

2012-01-01

"Unraveling Braid" analyzes how unconventional, non-linear narrative fiction can help explain the ways in which video games signify. Specifically, this essay looks at the links between the semiotic features of Jonathan Blow's 2008 puzzle-platform video game Braid and similar elements in Georges Perec's 1978 novel "Life A User's Manual," as well as…

Puzzling Science: Using the Rubik's Cube to Teach Problem Solving

ERIC Educational Resources Information Center

Rohrig, Brian

2010-01-01

A major goal of education is to help learners store information in long-term memory and use that information on later occasions to effectively solve problems (Vockell 2010). Therefore, this author began to use the Rubik's cube to help students learn to problem solve. There is something special about this colorful three-dimensional puzzle that…

Eta Carinae: A Box of Puzzles...Some Solved, Others Await

NASA Technical Reports Server (NTRS)

Gull, Theodore

2010-01-01

In the l840's, Eta Carinae brightened to rival Sirius, then faded. Today we see a marginally naked-eye binary with an expanding, very dusty bipolar Homunculus. The energetics of the ejected mass (>l2 to 40 solar masses at 500-700 km/s plus outer bullets/strings up to 3000 km/s} approach that of a supernova. Extragalactic SN surveys detect near-supernovae thought to be like the Great Eruption of the 1840's. Eta Carinae presents an abundance of puzzles: rich in N, but 1/100th the solar C and O abundances; Ti, V, Sr, Sc persist in atomic states.... yet an abundance of molecules and dust exists in the Homunculus. How did molecules and dust form with low C and O? A near supernova occurred in the l840m, yet both binary companions, with total mass > 120 solar masses, survive in a very eccentric orbit. What is the near future of this system: a GRB? a SN? or just two WR stars that ultimately become two SNs? These and other puzzles will be presented

A Hybrid alldifferent-Tabu Search Algorithm for Solving Sudoku Puzzles

PubMed Central

Crawford, Broderick; Paredes, Fernando; Norero, Enrique

2015-01-01

The Sudoku problem is a well-known logic-based puzzle of combinatorial number-placement. It consists in filling a n 2 × n 2 grid, composed of n columns, n rows, and n subgrids, each one containing distinct integers from 1 to n 2. Such a puzzle belongs to the NP-complete collection of problems, to which there exist diverse exact and approximate methods able to solve it. In this paper, we propose a new hybrid algorithm that smartly combines a classic tabu search procedure with the alldifferent global constraint from the constraint programming world. The alldifferent constraint is known to be efficient for domain filtering in the presence of constraints that must be pairwise different, which are exactly the kind of constraints that Sudokus own. This ability clearly alleviates the work of the tabu search, resulting in a faster and more robust approach for solving Sudokus. We illustrate interesting experimental results where our proposed algorithm outperforms the best results previously reported by hybrids and approximate methods. PMID:26078751

A Hybrid alldifferent-Tabu Search Algorithm for Solving Sudoku Puzzles.

PubMed

Soto, Ricardo; Crawford, Broderick; Galleguillos, Cristian; Paredes, Fernando; Norero, Enrique

2015-01-01

The Sudoku problem is a well-known logic-based puzzle of combinatorial number-placement. It consists in filling a n(2) × n(2) grid, composed of n columns, n rows, and n subgrids, each one containing distinct integers from 1 to n(2). Such a puzzle belongs to the NP-complete collection of problems, to which there exist diverse exact and approximate methods able to solve it. In this paper, we propose a new hybrid algorithm that smartly combines a classic tabu search procedure with the alldifferent global constraint from the constraint programming world. The alldifferent constraint is known to be efficient for domain filtering in the presence of constraints that must be pairwise different, which are exactly the kind of constraints that Sudokus own. This ability clearly alleviates the work of the tabu search, resulting in a faster and more robust approach for solving Sudokus. We illustrate interesting experimental results where our proposed algorithm outperforms the best results previously reported by hybrids and approximate methods.

Tiny bubbles challenge giant turbines: Three Gorges puzzle

PubMed Central

Li, Shengcai

2015-01-01

Since the birth of the first prototype of the modern reaction turbine, cavitation as conjectured by Euler in 1754 always presents as a challenge. Following his theory, the evolution of modern reaction (Francis and Kaplan) turbines has been completed by adding the final piece of the element ‘draft-tube’ that enables turbines to explore water energy at efficiencies of almost 100%. However, during the last two and a half centuries, with increasing unit capacity and specific speed, the problem of cavitation has been manifested and complicated by the draft-tube surges rather than being solved. Particularly, during the last 20 years, the fierce competition in the international market for extremely large turbines with compact design has encouraged the development of giant Francis turbines of 700–1000 MW. The first group (24 units) of such giant turbines of 700 MW each was installed in the Three Gorges project. Immediately after commission, a strange erosion phenomenon appeared on the guide vane of the machines that has puzzled professionals. From a multi-disciplinary analysis, this Three Gorges puzzle could reflect an unknown type of cavitation inception presumably triggered by turbulence production from the boundary-layer streak transitional process. It thus presents a fresh challenge not only to this old turbine industry, but also to the fundamental sciences. PMID:26442144

(Mis)perception of Sleep in Insomnia: A Puzzle and a Resolution

ERIC Educational Resources Information Center

Harvey, Allison G.; Tang, Nicole K. Y.

2012-01-01

Insomnia is prevalent, causing severe distress and impairment. This review focuses on illuminating the puzzling finding that many insomnia patients misperceive their sleep. They overestimate their sleep onset latency (SOL) and underestimate their total sleep time (TST), relative to objective measures. This tendency is ubiquitous (although not…

Solving the Puzzle of Metastasis: The Evolution of Cell Migration in Neoplasms

PubMed Central

Chen, Jun; Sprouffske, Kathleen; Huang, Qihong; Maley, Carlo C.

2011-01-01

Background Metastasis represents one of the most clinically important transitions in neoplastic progression. The evolution of metastasis is a puzzle because a metastatic clone is at a disadvantage in competition for space and resources with non-metastatic clones in the primary tumor. Metastatic clones waste some of their reproductive potential on emigrating cells with little chance of establishing metastases. We suggest that resource heterogeneity within primary tumors selects for cell migration, and that cell emigration is a by-product of that selection. Methods and Findings We developed an agent-based model to simulate the evolution of neoplastic cell migration. We simulated the essential dynamics of neoangiogenesis and blood vessel occlusion that lead to resource heterogeneity in neoplasms. We observed the probability and speed of cell migration that evolves with changes in parameters that control the degree of spatial and temporal resource heterogeneity. Across a broad range of realistic parameter values, increasing degrees of spatial and temporal heterogeneity select for the evolution of increased cell migration and emigration. Conclusions We showed that variability in resources within a neoplasm (e.g. oxygen and nutrients provided by angiogenesis) is sufficient to select for cells with high motility. These cells are also more likely to emigrate from the tumor, which is the first step in metastasis and the key to the puzzle of metastasis. Thus, we have identified a novel potential solution to the puzzle of metastasis. PMID:21556134

Adding a Piece to the Leaf Epidermal Cell Shape Puzzle.

PubMed

von Wangenheim, Daniel; Wells, Darren M; Bennett, Malcolm J

2017-11-06

The jigsaw puzzle-shaped pavement cells in the leaf epidermis collectively function as a load-bearing tissue that controls organ growth. In this issue of Developmental Cell, Majda et al. (2017) shed light on how the jigsaw shape can arise from localized variations in wall stiffness between adjacent epidermal cells. Copyright © 2017 Elsevier Inc. All rights reserved.

Nuclear clustering and the electron screening puzzle

NASA Astrophysics Data System (ADS)

Bertulani, C. A.; Spitaleri, C.

2018-01-01

Electron screening changes appreciably the magnitude of astrophysical nuclear reactions within stars. This effect is also observed in laboratory experiments on Earth, where atomic electrons are present in the nuclear targets. Theoretical models were developed over the past 30 years and experimental measurements have been carried out to study electron screening in thermonuclear reactions. None of the theoretical models were able to explain the high values of the experimentally determined screening potentials. We explore the possibility that the "electron screening puzzle" is due to nuclear clusterization and polarization e_ects in the fusion reactions. We will discuss the supporting arguments for this scenario.

Math Puzzlers: 25 Reproducible Puzzles, Games, and Activities that Boost the Math Skills and Up the Fun! Grades 2-5.

ERIC Educational Resources Information Center

Kimble-Ellis, Sonya

Puzzles, games, and activities provide perfect opportunities for students to work in groups, interact, communicate with each other, and discuss strategies. The activities, games, and puzzles contained in this book are designed to help students learn mathematics in a fun yet challenging way. The activities are designed to encourage students to…

Having Fun and Accepting Challenges Are Natural Instincts: Jigsaw Puzzles to Challenge Students and Test Their Abilities While Having Fun!

ERIC Educational Resources Information Center

Rodenbaugh, Hanna R.; Lujan, Heidi L.; Rodenbaugh, David W.; DiCarlo, Stephen E.

2014-01-01

Because jigsaw puzzles are fun, and challenging, students will endure and discover that persistence and grit are rewarded. Importantly, play and fun have a biological place just like sleep and dreams. Students also feel a sense of accomplishment when they have completed a puzzle. Importantly, the reward of mastering a challenge builds confidence…

"Pieces of a Puzzle": Seeing the Light in a Darkened Room.

ERIC Educational Resources Information Center

Lang, Frederick K.

The film "Pieces of a Puzzle" (part of the series "Writers Writing" that was coproduced by WNET and Learning Designs and televised by WNET in 1985), helped students become better writers and facilitated the discovery of material and techniques appropriate to academic writing. First, students were introduced to reader response…

General intelligence is an emerging property, not an evolutionary puzzle.

PubMed

Ramus, Franck

2017-01-01

Burkart et al. contend that general intelligence poses a major evolutionary puzzle. This assertion presupposes a reification of general intelligence - that is, assuming that it is one "thing" that must have been selected as such. However, viewing general intelligence as an emerging property of multiple cognitive abilities (each with their own selective advantage) requires no additional evolutionary explanation.

Gemini and Keck Observations of Slowly Rotating, Bilobate Active Asteroid (300163)

NASA Astrophysics Data System (ADS)

Waniak, Waclaw; Drahus, Michal

2016-10-01

One of the most puzzling questions regarding Active Asteroids is the mechanism of their activation. While some Active Asteroids show protracted and often recurrent mass loss, consistent with seasonal ice sublimation, some other eject dust impulsively as a result of a catastrophic disruption (e.g. Jewitt et al. 2015, Asteroids IV, 221). It has been suggested that ice can be excavated from the cold near-surface interior by an impact (Hsieh & Jewitt 2006, Science 312, 561) or, for small objects susceptible to YORP torques, by near-critical spin rate (Sheppard & Trujillo 2014, AJ 149, 44). But impact and rapid spin can also cause a catastrophic disruption (e.g. Jewitt et al. 2015, Asteroids IV, 221). It therefore becomes apparent that the different types of mass loss observed in Active Asteroids can be best classified and understood based on the nucleus spin rates (Drahus et al. 2015, ApJL 802, L8), but unfortunately the rotation periods have been measured for a very limited number of these objects. With this in mind we have initiated a survey of light curves of small Active Asteroids on the largest ground-based optical telescopes. Here we present the results for (300163), also known as 288P and 2006 VW139, which is a small 2.6-km sized asteroid that exhibited a comet-like activity over 100 days in the second half of 2011 (Hsieh et al. 2012, ApJL 748, L15; Licandro et al. 2013, A&A 550, A17; Agarwal et al. 2016, AJ 151, 12). Using Keck/DEIMOS and Gemini/GMOS-S working in tandem on UT 2015 May 21-22 we have detected an inactive nucleus and measured a complete, dense, high-S/N rotational light curve. The light curve has a double-peaked period of 16 hours, an amplitude of 0.4 mag, and moderately narrow minima suggesting a bilobate or contact-binary shape. The long rotation period clearly demonstrates a non-rotational origin of activity of this object, consistent with an impact. Furthermore, among the five small Active Asteroids with known rotation periods (300163) is only

Right frontal gamma and beta band enhancement while solving a spatial puzzle with insight.

PubMed

Rosen, A; Reiner, M

2017-12-01

Solving a problem with an "a-ha" effect is known as insight. Unlike incremental problem solving, insight is sudden and unique, and the question about its distinct brain activity, intrigues many researchers. In this study, electroencephalogram signals were recorded from 12 right handed, human participants before (baseline) and while they solved a spatial puzzle known as the '10 coin puzzle' that could be solved incrementally or by insight. Participants responded as soon as they reached a solution and reported whether the process was incremental or by sudden insight. EEG activity was recorded from 19 scalp locations. We found significant differences between insight and incremental solvers in the Gamma and Beta 2 bands in frontal areas (F8) and in the alpha band in right temporal areas (T6). The right-frontal gamma indicates a process of restructuring which leads to an insight solution, in spatial problems, further suggesting a universal role of gamma in restructuring. These results further suggest that solving a spatial puzzle via insight requires exclusive brain areas and neurological-cognitive processes which may be important for meta-cognitive components of insight solutions, including attention and monitoring of the solution. Copyright © 2016 Elsevier B.V. All rights reserved.

New Light on Autism and Other Puzzling Disorders of Childhood. Science Reports.

ERIC Educational Resources Information Center

Yahraes, Herbert

The pamphlet discusses several puzzling disorders of childhood, including autism, atypical personality development (childhood psychosis), psychosocial dwarfism, and Tourette's syndrome. Psychosocial dwarfism is said to be characterized by a marked reduction in physical development and by immaturity in behavior, while Tourette's syndrome involves…

Changes in food intake and abnormal behavior using a puzzle feeder in newly acquired sub-adult rhesus monkeys (Macaca mulatta): a short term study.

PubMed

Lee, Jae-Il; Lee, Chi-Woo; Kwon, Hyouk-Sang; Kim, Young-Tae; Park, Chung-Gyu; Kim, Sang-Joon; Kang, Byeong-Cheol

2008-10-01

The majority of newly acquired nonhuman primates encounter serious problems adapting themselves to new environments or facilities. In particular, loss of appetite and abnormal behavior can occur in response to environmental stresses. These adaptation abnormalities can ultimately have an affect on the animal's growth and well-being. In this study, we evaluated the affects of a puzzle feeder on the food intake and abnormal behavior of newly acquired rhesus monkeys for a short period. The puzzle feeder was applied to 47- to 58-month-old animals that had never previously encountered one. We found that there was no difference in the change of food intake between the bucket condition and the puzzle feeder condition. In contrast, the time spent for consumption of food was three times longer in the puzzle feeder condition than in the bucket condition. Two monkeys initially exhibited stereotypic behavior. One showed a decreasing, and the other an increasing pattern of abnormal behavior after introduction of the puzzle feeder. In conclusion, this result suggests that over a short period, the puzzle feeder can only affect the time for food consumption since it failed to affect the food intake and did not consistently influence stereotypic behaviors in newly acquired rhesus monkeys.

Health inequalities and welfare state regimes: theoretical insights on a public health 'puzzle'.

PubMed

Bambra, Clare

2011-09-01

Welfare states are important determinants of health. Comparative social epidemiology has almost invariably concluded that population health is enhanced by the relatively generous and universal welfare provision of the Scandinavian countries. However, most international studies of socioeconomic inequalities in health have thrown up something of a public health 'puzzle' as the Scandinavian welfare states do not, as would generally be expected, have the smallest health inequalities. This essay outlines and interrogates this puzzle by drawing upon existing theories of health inequalities--artefact, selection, cultural--behavioural, materialist, psychosocial and life course--to generate some theoretical insights. It discusses the limits of these theories in respect to cross-national research; it questions the focus and normative paradigm underpinning contemporary comparative health inequalities research; and it considers the future of comparative social epidemiology.

Freestyle multiple propeller flap reconstruction (jigsaw puzzle approach) for complicated back defects.

PubMed

Park, Sung Woo; Oh, Tae Suk; Eom, Jin Sup; Sun, Yoon Chi; Suh, Hyun Suk; Hong, Joon Pio

2015-05-01

The reconstruction of the posterior trunk remains to be a challenge as defects can be extensive, with deep dead space, and fixation devices exposed. Our goal was to achieve a tension-free closure for complex defects on the posterior trunk. From August 2006 to May 2013, 18 cases were reconstructed with multiple flaps combining perforator(s) and local skin flaps. The reconstructions were performed using freestyle approach. Starting with propeller flap(s) in single or multilobed design and sequentially in conjunction with adjacent random pattern flaps such as fitting puzzle. All defects achieved tensionless primary closure. The final appearance resembled a jigsaw puzzle-like appearance. The average size of defect was 139.6 cm(2) (range, 36-345 cm(2)). A total of 26 perforator flaps were used in addition to 19 random pattern flaps for 18 cases. In all cases, a single perforator was used for each propeller flap. The defect and the donor site all achieved tension-free closure. The reconstruction was 100% successful without flap loss. One case of late infection was noted at 12 months after surgery. Using multiple lobe designed propeller flaps in conjunction with random pattern flaps in a freestyle approach, resembling putting a jigsaw puzzle together, we can achieve a tension-free closure by distributing the tension to multiple flaps, supplying sufficient volume to obliterate dead space, and have reliable vascularity as the flaps do not need to be oversized. This can be a viable approach to reconstruct extensive defects on the posterior trunk. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

The proton radius puzzle

NASA Astrophysics Data System (ADS)

Bonesini, Maurizio

2017-12-01

The FAMU (Fisica degli Atomi Muonici) experiment has the goal to measure precisely the proton Zemach radius, thus contributing to the solution of the so-called proton radius "puzzle". To this aim, it makes use of a high-intensity pulsed muon beam at RIKEN-RAL impinging on a cryogenic hydrogen target with an high-Z gas admixture and a tunable mid-IR high power laser, to measure the hyperfine (HFS) splitting of the 1S state of the muonic hydrogen. From the value of the exciting laser frequency, the energy of the HFS transition may be derived with high precision ( 10-5) and thus, via QED calculations, the Zemach radius of the proton. The experimental apparatus includes a precise fiber-SiPMT beam hodoscope and a crown of eight LaBr3 crystals and a few HPGe detectors for detection of the emitted characteristic X-rays. Preliminary runs to optimize the gas target filling and its operating conditions have been taken in 2014 and 2015-2016. The final run, with the pump laser to drive the HFS transition, is expected in 2018.

Unusual Internal Rotation Coupling in the Microwave Spectrum of Pinacolone

NASA Astrophysics Data System (ADS)

Zhao, YueYue; Nguyen, Ha Vinh Lam; Stahl, Wolfgang; Hougen, Jon T.

2015-06-01

The molecular-beam Fourier-transform microwave spectrum of pinacolone (methyl tert-butyl ketone) has been measured in several regions between 2 and 40 GHz. Assignments of a large number of A and E transitions were confirmed by combination differences, but fits of the assigned spectrum using several torsion-rotation computer programs based on different models led to the unexpected conclusion that no existing program correctly captures the internal dynamics of this molecule. A second puzzle arose when it became clear that roughly half of the spectrum remained unassigned even after all predicted transitions were added to the assignment list. Quantum chemical calculations carried out at the MP2/6-311++G(d,p) level indicate that this molecule does not have a plane of symmetry at equilibrium, and that internal rotation of the light methyl group induces a large oscillatory motion of the heavy tert-butyl group from one side of the C_s saddle point to the other. The effect of this non-C_s equilibrium structure was modeled for J = 0 levels by a simple two-top torsional Hamiltonian, where magnitudes of the strong top-top coupling terms were determined directly from the ab initio two-dimensional potential surface. A plot of the resultant torsional levels on the same scale as a one-dimensional potential curve along the zig-zag path connecting the six (unequally spaced) minima bears a striking resemblance to the 1:2:1 splitting pattern of levels in an internal rotation problem with a six-fold barrier. A plot of the six minima closely resembles the potential surface for methylamine. This talk will focus on implications of these resemblances for future work.

FIRST OBSERVATIONAL SIGNATURE OF ROTATIONAL DECELERATION IN A MASSIVE, INTERMEDIATE-AGE STAR CLUSTER IN THE MAGELLANIC CLOUDS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Xiaohan; Li, Chengyuan; De Grijs, Richard

While the extended main-sequence turnoffs (eMSTOs) found in almost all 1–2 Gyr old star clusters in the Magellanic Clouds are often explained by postulating extended star formation histories (SFHs), the tight subgiant branches (SGBs) seen in some clusters challenge this popular scenario. Puzzlingly, the SGB of the eMSTO cluster NGC 419 is significantly broader at bluer than at redder colors. We carefully assess and confirm the reality of this observational trend. If we would assume that the widths of the features in color–magnitude space were entirely owing to a range in stellar ages, the SFHs of the eMSTO stars andmore » the blue SGB region would be significantly more prolonged than that of the red part of the SGB. This cannot be explained by assuming an internal age spread. We show that rotational deceleration of a population of rapidly rotating stars, a currently hotly debated alternative scenario, naturally explains the observed trend along the SGB. Our analysis shows that a “converging” SGB could be produced if the cluster is mostly composed of rapidly rotating stars that slow down over time owing to the conservation of angular momentum during their evolutionary expansion from main-sequence turnoff stars to red giants.« less

A Personal Intelligent Mentor for Promoting Metacognition in Solving Logic Word Puzzles.

ERIC Educational Resources Information Center

Baylor, Amy L.; Kozbe, Barcin

This paper describes a Personal Intelligent Mentor (PIM) that facilitates metacognitive development in the domain of solving logic word puzzles. Metacognition is an important aspect for critical thinking skills. High school students must develop logical and critical thinking abilities as a prerequisite for higher-level math and computer…

The Puzzle of a Marble in a Spinning Pipe

DTIC Science & Technology

2015-05-01

MAY 2015 2. REPORT TYPE 3. DATES COVERED 00-00-2015 to 00-00-2015 4. TITLE AND SUBTITLE The Puzzle of a Marble in a Spinning Pipe 5a. CONTRACT...Approved for public release; distribution unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT What trajectory does a marble follow if it is held...298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 Physics Education 50 (3) 279 1. Problem statement A marble is placed one-third of the length along a

Generating Sudoku puzzles and its applications in teaching mathematics

NASA Astrophysics Data System (ADS)

Evans, Ryan; Lindner, Brett; Shi, Yixun

2011-07-01

This article presents a few methods for generating Sudoku puzzles. These methods are developed based on the concepts of matrix, permutation, and modular functions, and therefore can be used to form application examples or student projects when teaching various mathematics courses. Mathematical properties of these methods are studied, connections between the methods are investigated, and student projects are suggested. Since most students tend to enjoy games, studies like this may help raising students' interests and enhance their problem-solving skills.

The Puzzle of Male Chronophilias.

PubMed

Seto, Michael C

2017-01-01

In this article, I return to the idea that pedophilia, a sexual interest in prepubescent children, can be considered a sexual orientation for age, in conjunction with the much more widely acknowledged and discussed sexual orientation for gender. Here, I broaden the scope to consider other chronophilias, referring to paraphilias for age/maturity categories other than young sexually mature adults. The puzzle of chronophilias includes questions about etiology and course, how chronophilias are related to each other, and what they can tell us about how human (male) sexuality is organized. In this article, I briefly review research on nepiophilia (infant/toddlers), pedophilia (prepubescent children), hebephilia (pubescent children), ephebophilia (postpubescent, sexually maturing adolescents), teleiophilia (young sexually mature adults, typically 20s and 30s), mesophilia (middle-aged adults, typically 40s and 50s), and gerontophilia (elderly adults, typically 60s and older) in the context of a multidimensional sexual orientations framework. Relevant research, limitations, and testable hypotheses for future work are identified.

Effects of age and type of picture on visuospatial working memory assessed with a computerized jigsaw-puzzle task.

PubMed

Toril, Pilar; Reales, José M; Mayas, Julia; Ballesteros, Soledad

2017-09-15

We investigated the effect of age and color in a computerized version of the jigsaw-puzzle task. In Experiment 1, young and older adults were presented with puzzles in color and black-and-white line drawings, varying in difficulty from 4 to 9 pieces. Older adults performed the task better with the black-and-white stimuli and younger adults performed better with the color ones. In Experiment 2, new older and young adults identified the same fragmented pictures as fast and accurately as possible. The older group identified the black-and-white stimuli faster than those presented in color, while the younger adults identified both similarly. In Experiment 3A, new older and young groups performed the puzzle task with the same color pictures and their monochrome versions. In Experiment 3B, participants performed a speeded identification task with the two sets. The findings of these experiments showed that older adults have a memory not a perceptual difficulty.

Tetsuo Nozoe's Autograph Books: poems, puzzles and playfulness.

PubMed

Seeman, Jeffrey I

2015-02-01

The Nozoe Autograph Books contain entries from, literally, around the world of organic chemistry. Many of the inscriptions showed the poetic or even musical side of their signees. This Essay presents a diverse selection of the poetic entries of the autograph books, starting with a musical puzzle. This Essay and the interactive website that accompanies the Nozoe Autograph Book project are available free-access for at least a three-year period at http://www.tcr.wiley-vch.de/nozoe. Copyright © 2015 The Chemical Society of Japan and Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Jigsaw Puzzles and River Banks: Two Ways of Picturing Our Future

ERIC Educational Resources Information Center

Kretchmar, R. Scott

2005-01-01

The papers presented at the 2004 Academy meetings can be thought of as pieces from jigsaw puzzles. While the employment of this metaphor over the years has been useful, we may be ready for a new image, one that is both more accurate and inspiring. We can picture ourselves working at different locations along a river bank. Some of us work upstream,…

Engaging Students in a Large Lecture: An Experiment Using Sudoku Puzzles

ERIC Educational Resources Information Center

Brophy, Caroline; Hahn, Lukas

2014-01-01

In this paper, we describe an in-class experiment that is easy to implement with large groups of students. The experiment takes approximately 15-20 minutes to run and involves each student completing one of four types of Sudoku puzzles and recording the time it takes to completion. The resulting data set can be used as a teaching tool at an…

Reconstructing plate-motion changes in the presence of finite-rotations noise.

PubMed

Iaffaldano, Giampiero; Bodin, Thomas; Sambridge, Malcolm

2012-01-01

Understanding lithospheric plate motions is of paramount importance to geodynamicists. Much effort is going into kinematic reconstructions featuring progressively finer temporal resolution. However, the challenge of precisely identifying ocean-floor magnetic lineations, and uncertainties in geomagnetic reversal timescales result in substantial finite-rotations noise. Unless some type of temporal smoothing is applied, the scenario arising at the native temporal resolution is puzzling, as plate motions vary erratically and significantly over short periods (<1 Myr). This undermines our ability to make geodynamic inferences, as the rates at which forces need to be built upon plates to explain these kinematics far exceed the most optimistic estimates. Here we show that the largest kinematic changes reconstructed across the Atlantic, Indian and South Pacific ridges arise from data noise. We overcome this limitation using a trans-dimensional hierarchical Bayesian framework. We find that plate-motion changes occur on timescales no shorter than a few million years, yielding simpler kinematic patterns and more plausible dynamics.

The birth order puzzle.

PubMed

Zajonc, R B; Markus, H; Markus, G B

1979-08-01

Studies relating intellectual performance to birth order report conflicting results, some finding intellectual scores to increase, others to decrease with birth order. In contrast, the relationship between intellectual performance and family size is stable and consistently replicable. Why do these two highly related variables generate such divergent results? This birth order puzzle is resolved by means of the confluence model that quantifies the influences upon intellectual growth arising within the family context. At the time of a new birth, two opposing influences act upon intellectual growth of the elder sibling: (a) his or her intellectual environment is "diluted" and (b) he or she loses the "last-born's handicap" and begins serving as an intellectual resource to the younger sibling. Since these opposite effects are not equal in magnitude, the differences in intellectual performance among birth ranks are shown to be age dependent. While elder children may surpass their younger siblings in intellectual performance at some ages, they may be overtaken by them at others. Thus when age is taken into consideration, the birth order literature loses its chaotic character and an orderly pattern of results emerges.

Hubble Gazes Into a Black Hole of Puzzling Light

NASA Image and Video Library

2017-12-08

The beautiful spiral galaxy visible in the center of the image is known as RX J1140.1+0307, a galaxy in the Virgo constellation imaged by the NASA/ESA Hubble Space Telescope, and it presents an interesting puzzle. At first glance, this galaxy appears to be a normal spiral galaxy, much like the Milky Way, but first appearances can be deceptive! The Milky Way galaxy, like most large galaxies, has a supermassive black hole at its center, but some galaxies are centered on lighter, intermediate-mass black holes. RX J1140.1+0307 is such a galaxy — in fact, it is centered on one of the lowest black hole masses known in any luminous galactic core. What puzzles scientists about this particular galaxy is that the calculations don’t add up. With such a relatively low mass for the central black hole, models for the emission from the object cannot explain the observed spectrum. There must be other mechanisms at play in the interactions between the inner and outer parts of the accretion disk surrounding the black hole. Credit: ESA/Hubble & NASA, Acknowledgement: Judy Schmidt NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Studies in Mathematics, Volume XVIII: Puzzle Problems and Games Project. Final Report.

ERIC Educational Resources Information Center

Dilworth, R. P.; And Others

This is a self-contained manual for use by teachers in preparation for classroom presentations. One of the goals of the report is to show how games and puzzles can provide effective means for developing mathematical understanding and skills. The authors indicate that this type of activity is well adapted for discovery teaching techniques. The…

The Retention Puzzle Reconsidered: Second Year Student Attitudes and Experiences with Advising

ERIC Educational Resources Information Center

Walsh, Michael Edward

2013-01-01

College student retention has been described as a puzzle because retention rates have stagnated, and in some cases declined, despite over seventy years of research into the problem. The magnitude of the problem is that 50 percent of college students will leave their institution before obtaining a degree (Braxton, Hirschy, & McClendon, 2011).…

New Nuclear Magnetic Moment of ^{209}Bi: Resolving the Bismuth Hyperfine Puzzle.

PubMed

Skripnikov, Leonid V; Schmidt, Stefan; Ullmann, Johannes; Geppert, Christopher; Kraus, Florian; Kresse, Benjamin; Nörtershäuser, Wilfried; Privalov, Alexei F; Scheibe, Benjamin; Shabaev, Vladimir M; Vogel, Michael; Volotka, Andrey V

2018-03-02

A recent measurement of the hyperfine splitting in the ground state of Li-like ^{208}Bi^{80+} has established a "hyperfine puzzle"-the experimental result exhibits a 7σ deviation from the theoretical prediction [J. Ullmann et al., Nat. Commun. 8, 15484 (2017)NCAOBW2041-172310.1038/ncomms15484; J. P. Karr, Nat. Phys. 13, 533 (2017)NPAHAX1745-247310.1038/nphys4159]. We provide evidence that the discrepancy is caused by an inaccurate value of the tabulated nuclear magnetic moment (μ_{I}) of ^{209}Bi. We perform relativistic density functional theory and relativistic coupled cluster calculations of the shielding constant that should be used to extract the value of μ_{I}(^{209}Bi) and combine it with nuclear magnetic resonance measurements of Bi(NO_{3})_{3} in nitric acid solutions and of the hexafluoridobismuthate(V) BiF_{6}^{-} ion in acetonitrile. The result clearly reveals that μ_{I}(^{209}Bi) is much smaller than the tabulated value used previously. Applying the new magnetic moment shifts the theoretical prediction into agreement with experiment and resolves the hyperfine puzzle.

New Nuclear Magnetic Moment of 209Bi: Resolving the Bismuth Hyperfine Puzzle

NASA Astrophysics Data System (ADS)

Skripnikov, Leonid V.; Schmidt, Stefan; Ullmann, Johannes; Geppert, Christopher; Kraus, Florian; Kresse, Benjamin; Nörtershäuser, Wilfried; Privalov, Alexei F.; Scheibe, Benjamin; Shabaev, Vladimir M.; Vogel, Michael; Volotka, Andrey V.

2018-03-01

A recent measurement of the hyperfine splitting in the ground state of Li-like 80+208Bi has established a "hyperfine puzzle"—the experimental result exhibits a 7 σ deviation from the theoretical prediction [J. Ullmann et al., Nat. Commun. 8, 15484 (2017), 10.1038/ncomms15484; J. P. Karr, Nat. Phys. 13, 533 (2017), 10.1038/nphys4159]. We provide evidence that the discrepancy is caused by an inaccurate value of the tabulated nuclear magnetic moment (μI) of 209Bi. We perform relativistic density functional theory and relativistic coupled cluster calculations of the shielding constant that should be used to extract the value of μI(209ipts>) and combine it with nuclear magnetic resonance measurements of Bi (NO3 )3 in nitric acid solutions and of the hexafluoridobismuthate(V) BiF6- ion in acetonitrile. The result clearly reveals that μI(209Bi) is much smaller than the tabulated value used previously. Applying the new magnetic moment shifts the theoretical prediction into agreement with experiment and resolves the hyperfine puzzle.

Puzzle of magnetic moments of Ni clusters revisited using quantum Monte Carlo method.

PubMed

Lee, Hung-Wen; Chang, Chun-Ming; Hsing, Cheng-Rong

2017-02-28

The puzzle of the magnetic moments of small nickel clusters arises from the discrepancy between values predicted using density functional theory (DFT) and experimental measurements. Traditional DFT approaches underestimate the magnetic moments of nickel clusters. Two fundamental problems are associated with this puzzle, namely, calculating the exchange-correlation interaction accurately and determining the global minimum structures of the clusters. Theoretically, the two problems can be solved using quantum Monte Carlo (QMC) calculations and the ab initio random structure searching (AIRSS) method correspondingly. Therefore, we combined the fixed-moment AIRSS and QMC methods to investigate the magnetic properties of Ni n (n = 5-9) clusters. The spin moments of the diffusion Monte Carlo (DMC) ground states are higher than those of the Perdew-Burke-Ernzerhof ground states and, in the case of Ni 8-9 , two new ground-state structures have been discovered using the DMC calculations. The predicted results are closer to the experimental findings, unlike the results predicted in previous standard DFT studies.

Heavy flavor puzzle at LHC: a serendipitous interplay of jet suppression and fragmentation.

PubMed

Djordjevic, Magdalena

2014-01-31

Both charged hadrons and D mesons are considered to be excellent probes of QCD matter created in ultrarelativistic heavy ion collisions. Surprisingly, recent experimental observations at LHC show the same jet suppression for these two probes, which--contrary to pQCD expectations--may suggest similar energy losses for light quarks and gluons in the QCD medium. We here use our recently developed energy loss formalism in a finite-size dynamical QCD medium to analyze this phenomenon that we denote as the "heavy flavor puzzle at LHC." We show that this puzzle is a consequence of an unusual combination of the suppression and fragmentation patterns and, in fact, does not require invoking the same energy loss for light partons. Furthermore, we show that this combination leads to a simple relationship between the suppressions of charged hadrons and D mesons and the corresponding bare quark suppressions. Consequently, a coincidental matching of jet suppression and fragmentation allows considerably simplifying the interpretation of the corresponding experimental data.

Resolution to the B→πK puzzle

NASA Astrophysics Data System (ADS)

Li, Hsiang-Nan; Mishima, Satoshi; Sanda, A. I.

2005-12-01

We calculate the important next-to-leading-order contributions to the B→πK, ππ decays from the vertex corrections, the quark loops, and the magnetic penguins in the perturbative QCD approach. It is found that the latter two reduce the leading-order penguin amplitudes by about 10% and modify only the B→πK branching ratios. The main effect of the vertex corrections is to increase the small color-suppressed tree amplitude by a factor of 3, which then resolves the large difference between the direct CP asymmetries of the B0→π∓K± and B±→π0K± modes. The puzzle from the large B0→π0π0 branching ratio still remains.

"It's like a puzzle": Pregnant women's perceptions of professional support in midwifery care.

PubMed

Bäckström, Caroline A; Mårtensson, Lena B; Golsäter, Marie H; Thorstensson, Stina A

2016-12-01

Pregnant women are not always satisfied with the professional support they receive during their midwifery care. More knowledge is needed to understand what professional support pregnant women need for childbirth and parenting. Childbearing and the transition to becoming a parent is a sensitive period in one's life during which one should have the opportunity to receive professional support. Professional support does not always correspond to pregnant women's needs. To understand pregnant women's needs for professional support within midwifery care, it is crucial to further illuminate women's experiences of this support. To explore pregnant women's perceptions of professional support in midwifery care. A qualitative study using semi-structured interviews. Fifteen women were interviewed during gestational weeks 36-38. Data was analysed using phenomenography. The women perceived professional support in midwifery care to be reassuring and emotional, to consist of reliable information, and to be mediated with pedagogical creativity. The professional support facilitated new social contacts, partner involvement and contributed to mental preparedness. The findings of the study were presented in six categories and the category Professional support contributes to mental preparedness was influenced by the five other categories. Pregnant women prepare for childbirth and parenting by using several different types of professional support in midwifery care: a strategy that could be described as piecing together a puzzle. When the women put the puzzle together, each type of professional support works as a valuable piece in the whole puzzle. Through this, professional support could contribute to women's mental preparedness for childbirth and parenting. Copyright © 2016 Australian College of Midwives. Published by Elsevier Ltd. All rights reserved.

A resolution of the inclusive flavor-breaking τ |Vus| puzzle

NASA Astrophysics Data System (ADS)

Hudspith, Renwick J.; Lewis, Randy; Maltman, Kim; Zanotti, James

2018-06-01

We revisit the puzzle of |Vus | values obtained from the conventional implementation of hadronic-τ- decay-based flavor-breaking finite-energy sum rules lying > 3 σ below the expectations of three-family unitarity. Significant unphysical dependences of |Vus | on the choice of weight, w, and upper limit, s0, of the experimental spectral integrals entering the analysis are confirmed, and a breakdown of assumptions made in estimating higher dimension, D > 4, OPE contributions identified as the main source of these problems. A combination of continuum and lattice results is shown to suggest a new implementation of the flavor-breaking sum rule approach in which not only |Vus |, but also D > 4 effective condensates, are fit to data. Lattice results are also used to clarify how to reliably treat the slowly converging D = 2 OPE series. The new sum rule implementation is shown to cure the problems of the unphysical w- and s0-dependence of |Vus | and to produce results ∼0.0020 higher than those of the conventional implementation employing the same data. With B-factory input, and using, in addition, dispersively constrained results for the Kπ branching fractions, we find |Vus | = 0.2231(27)exp(4)th, in excellent agreement with the result from Kℓ3, and compatible within errors with the expectations of three-family unitarity, thus resolving the long-standing inclusive τ |Vus | puzzle.

A light Z' for the R K puzzle and nonstandard neutrino interactions

DOE PAGES

Datta, Alakabha; Liao, Jiajun; Marfatia, Danny

2017-03-01

We show that the R K puzzle in LHCb data and the discrepancy in the anomalous magnetic moment of the muon can be simultaneously explained if a 10 MeV mass Z' boson couples to the muon but not the electron, and that clear evidence of the nonstandard matter interactions of neutrinos induced by this coupling may be found at DUNE.

The Puzzles of the Vela Pulsar-Wind Nebula

NASA Astrophysics Data System (ADS)

Kargaltsev, Oleg; Pavlov, G. G.

2008-03-01

Very few pulsar wind nebulae (PWNe) can be studied at the level of detail comparable to that achieved for the Crab PWN. The nearby Vela PWN is the best candidate for such an in-depth study. Using Chandra ACIS observations of 2000-2002, we produced a "movie" which shows that not only the NW outer jet, reported by Pavlov et al. (2003), but also the entire bright Vela PWN is remarkably variable. The most dramatic changes occur in the outer arc, the SE inner jet, and the bright knots in the SE part of the inner PWN. On a time scale of 1-3 weeks, the outer arc changes its brightness, shape, and spectrum, the knots move, disappear and appear again, while the SE inner jet changes its brightness and size. In contrast with the Crab PWN, we see no moving "wisps". The observed changes can be attributed to instabilities in the pulsar wind and to varying density/pressure in the ambient medium. Deep combined images show that the inner arc is part of a ring, but the pulsar is offset from its plane. The large width of the SE outer "jet" suggests either an intrinsic asymmetry of the SE and NW polar outflows or that the SE jet broadens in a low-pressure cavity behind the moving pulsar. We also found a puzzling "bar" at the base of the inner SE jet, possibly a shock in a polar outflow. An adaptively binned spectral map demonstrates that the inner PWN elements have extremely hard spectra (significantly harder than those of the Crab inner PWN), incompatible with those predicted by the shock acceleration models. Overall, the Vela PWN shows a wealth of puzzling features, different from the Crab; their nature can be understood in a specially designed series of Chandra ACIS observations.

Gardner's Two Children Problems and Variations: Puzzles with Conditional Probability and Sample Spaces

ERIC Educational Resources Information Center

Taylor, Wendy; Stacey, Kaye

2014-01-01

This article presents "The Two Children Problem," published by Martin Gardner, who wrote a famous and widely-read math puzzle column in the magazine "Scientific American," and a problem presented by puzzler Gary Foshee. This paper explains the paradox of Problems 2 and 3 and many other variations of the theme. Then the authors…

Mental Rotation, Pictured Rotation, and Tandem Rotation in Depth

DTIC Science & Technology

1997-01-01

field. Such an explanation by natural geometry conflates visual comparison with physical measurement. This application of geometry is called natural in...the theory of vision parasitic on geometry: it is unclear what could be meant by a ’mental operation of rotation’, except by reference to physical ...operation, a mental analogue of the physical operation of rotation in space. Since then the story of mental rotation has become far more complicated

The Quark Puzzle: A Novel Approach to Visualizing the Color Symmetries of Quarks

ERIC Educational Resources Information Center

Gettrust, Eric

2010-01-01

This paper describes a simple hands-on and visual-method designed to introduce physics students of many age groups to the topic of quarks and their role in forming composite particles (baryons and mesons). A set of puzzle pieces representing individual quarks that fit together in ways consistent with known restrictions of flavor, color, and charge…

Rotator cuff tendon connections with the rotator cable.

PubMed

Rahu, Madis; Kolts, Ivo; Põldoja, Elle; Kask, Kristo

2017-07-01

The literature currently contains no descriptions of the rotator cuff tendons, which also describes in relation to the presence and characteristics of the rotator cable (anatomically known as the ligamentum semicirculare humeri). The aim of the current study was to elucidate the detailed anatomy of the rotator cuff tendons in association with the rotator cable. Anatomic dissection was performed on 21 fresh-frozen shoulder specimens with an average age of 68 years. The rotator cuff tendons were dissected from each other and from the glenohumeral joint capsule, and the superior glenohumeral, coracohumeral, coracoglenoidal and semicircular (rotator cable) ligaments were dissected. Dissection was performed layer by layer and from the bursal side to the joint. All ligaments and tendons were dissected in fine detail. The rotator cable was found in all specimens. It was tightly connected to the supraspinatus (SSP) tendon, which was partly covered by the infraspinatus (ISP) tendon. The posterior insertion area of the rotator cable was located in the region between the middle and inferior facets of the greater tubercle of the humerus insertion areas for the teres minor (TM), and ISP tendons were also present and fibres from the SSP extended through the rotator cable to those areas. The connection between the rotator cable and rotator cuff tendons is tight and confirms the suspension bridge theory for rotator cuff tears in most areas between the SSP tendons and rotator cable. In its posterior insertion area, the rotator cable is a connecting structure between the TM, ISP and SSP tendons. These findings might explain why some patients with relatively large rotator cuff tears can maintain seamless shoulder function.

A Solar Cycle Prediction Puzzle's PossibleExplanation?

NASA Astrophysics Data System (ADS)

Luhmann, Janet

2007-05-01

A long-standing and intriguing puzzle of the last few decades has been Joan Feynman's (1982) discovery that the solar cycle (sunspot number) maximum trends follow the level of geomagnetic activity during the prior minimum phase. Recently Hathaway (GRL 33, 2006) used this relationship to make a prediction of the size of the next solar maximum. But the physical reason why this should work at all remains a matter of speculation. Although it has been suggested that geomagnetic activity around solar minimum is determined by the terrestrial magnetosphere's response to high speed solar wind streams which seem to often characterize the declining phase of the cycle, why should the occurrence of these streams portend the new solar maximum? Our improving understanding of solar wind sources may hold the key, and also tell us something useful about the solar dynamo.

The electron screening puzzle and nuclear clustering

DOE PAGES

Spitaleri, C.; Bertulani, C. A.; Fortunato, L.; ...

2016-02-12

Accurate measurements of nuclear reactions of astrophysical interest within, or close to, the Gamow peak show evidence of an unexpected effect attributed to the presence of atomic electrons in the target. The experiments need to include an effective "screening" potential to explain the enhancement of the cross sections at the lowest measurable energies. Despite various theoretical studies conducted over the past 20 years and numerous experimental measurements, a theory has not yet been found that can explain the cause of the exceedingly high values of the screening potential needed to explain the data. Furthermore, in this letter we show thatmore » instead of an atomic physics solution of the "electron screening puzzle", the reason for the large screening potential values is in fact due to clusterization effects in nuclear reactions, in particular for reaction involving light nuclei.« less

The Role of Inhibitory Control in Children's Cooperative Behaviors during a Structured Puzzle Task

ERIC Educational Resources Information Center

Giannotta, Fabrizia; Burk, William J.; Ciairano, Silvia

2011-01-01

This study examined the role of inhibitory control (measured by Stroop interference) in children's cooperative behaviors during a structured puzzle task. The sample consisted of 250 8-, 10-, and 12-year-olds (117 girls and 133 boys) attending classrooms in three primary schools in Northern Italy. Children individually completed an elaborated…

A Public-Key Based Authentication and Key Establishment Protocol Coupled with a Client Puzzle.

ERIC Educational Resources Information Center

Lee, M. C.; Fung, Chun-Kan

2003-01-01

Discusses network denial-of-service attacks which have become a security threat to the Internet community and suggests the need for reliable authentication protocols in client-server applications. Presents a public-key based authentication and key establishment protocol coupled with a client puzzle protocol and validates it through formal logic…

Multiple sclerosis pathogenesis: missing pieces of an old puzzle.

PubMed

Rahmanzadeh, Reza; Brück, Wolfgang; Minagar, Alireza; Sahraian, Mohammad Ali

2018-06-08

Traditionally, multiple sclerosis (MS) was considered to be a CD4 T cell-mediated CNS autoimmunity, compatible with experimental autoimmune encephalitis model, which can be characterized by focal lesions in the white matter. However, studies of recent decades revealed several missing pieces of MS puzzle and showed that MS pathogenesis is more complex than the traditional view and may include the following: a primary degenerative process (e.g. oligodendroglial pathology), generalized abnormality of normal-appearing brain tissue, pronounced gray matter pathology, involvement of innate immunity, and CD8 T cells and B cells. Here, we review these findings and discuss their implications in MS pathogenesis.

Ambiguity aversion and household portfolio choice puzzles: Empirical evidence*

PubMed Central

Dimmock, Stephen G.; Kouwenberg, Roy; Mitchell, Olivia S.; Peijnenburg, Kim

2017-01-01

We test the relation between ambiguity aversion and five household portfolio choice puzzles: nonparticipation in equities, low allocations to equity, home-bias, own-company stock ownership, and portfolio under-diversification. In a representative US household survey, we measure ambiguity preferences using custom-designed questions based on Ellsberg urns. As theory predicts, ambiguity aversion is negatively associated with stock market participation, the fraction of financial assets in stocks, and foreign stock ownership, but it is positively related to own-company stock ownership. Conditional on stock ownership, ambiguity aversion is related to portfolio under-diversification, and during the financial crisis, ambiguity-averse respondents were more likely to sell stocks. PMID:28458446

Ambiguity aversion and household portfolio choice puzzles: Empirical evidence.

PubMed

Dimmock, Stephen G; Kouwenberg, Roy; Mitchell, Olivia S; Peijnenburg, Kim

2016-03-01

We test the relation between ambiguity aversion and five household portfolio choice puzzles: nonparticipation in equities, low allocations to equity, home-bias, own-company stock ownership, and portfolio under-diversification. In a representative US household survey, we measure ambiguity preferences using custom-designed questions based on Ellsberg urns. As theory predicts, ambiguity aversion is negatively associated with stock market participation, the fraction of financial assets in stocks, and foreign stock ownership, but it is positively related to own-company stock ownership. Conditional on stock ownership, ambiguity aversion is related to portfolio under-diversification, and during the financial crisis, ambiguity-averse respondents were more likely to sell stocks.

Gaia's view of the λ Boo star puzzle

NASA Astrophysics Data System (ADS)

Murphy, Simon J.; Paunzen, Ernst

2017-04-01

The evolutionary status of the chemically peculiar class of λ Boo stars has been intensely debated. It is now agreed that the λ Boo phenomenon affects A stars of all ages, from star formation to the terminal age main sequence, but the cause of the chemical peculiarity is still a puzzle. We revisit the debate of their ages and temperatures in order to shed light on the phenomenon, using the new parallaxes in Gaia Data Release 1 with existing Hipparcos parallaxes and multicolour photometry. We find that no single formation mechanism is able to explain all the observations, and suggest that there are multiple channels producing λ Boo spectra. The relative importance of these channels varies with age, temperature and environment.

Schooling, Cognitive Skills, and the Latin American Growth Puzzle. NBER Working Paper No. 15066

ERIC Educational Resources Information Center

Hanushek, Eric A.; Woessmann, Ludger

2009-01-01

Economic development in Latin America has trailed most other world regions over the past four decades despite its relatively high initial development and school attainment levels. This puzzle can be resolved by considering the actual learning as expressed in tests of cognitive skills, on which Latin American countries consistently perform at the…

Puzzle-based versus traditional lecture: comparing the effects of pedagogy on academic performance in an undergraduate human anatomy and physiology II lab.

PubMed

Stetzik, Lucas; Deeter, Anthony; Parker, Jamie; Yukech, Christine

2015-06-23

A traditional lecture-based pedagogy conveys information and content while lacking sufficient development of critical thinking skills and problem solving. A puzzle-based pedagogy creates a broader contextual framework, and fosters critical thinking as well as logical reasoning skills that can then be used to improve a student's performance on content specific assessments. This paper describes a pedagogical comparison of traditional lecture-based teaching and puzzle-based teaching in a Human Anatomy and Physiology II Lab. Using a single subject/cross-over design half of the students from seven sections of the course were taught using one type of pedagogy for the first half of the semester, and then taught with a different pedagogy for the second half of the semester. The other half of the students were taught the same material but with the order of the pedagogies reversed. Students' performance on quizzes and exams specific to the course, and in-class assignments specific to this study were assessed for: learning outcomes (the ability to form the correct conclusion or recall specific information), and authentic academic performance as described by (Am J Educ 104:280-312, 1996). Our findings suggest a significant improvement in students' performance on standard course specific assessments using a puzzle-based pedagogy versus a traditional lecture-based teaching style. Quiz and test scores for students improved by 2.1 and 0.4% respectively in the puzzle-based pedagogy, versus the traditional lecture-based teaching. Additionally, the assessments of authentic academic performance may only effectively measure a broader conceptual understanding in a limited set of contexts, and not in the context of a Human Anatomy and Physiology II Lab. In conclusion, a puzzle-based pedagogy, when compared to traditional lecture-based teaching, can effectively enhance the performance of students on standard course specific assessments, even when the assessments only test a limited

Interference between a fast-paced spatial puzzle task and verbal memory demands.

PubMed

Epling, Samantha L; Blakely, Megan J; Russell, Paul N; Helton, William S

2017-06-01

Research continues to provide evidence that people are poor multi-taskers. Cognitive resource theory is a common explanation for the inability to efficiently perform multiple tasks at the same time. This theory proposes that one's limited supply of cognitive resources can be utilized faster than it is replenished, which results in a performance decline, particularly when these limited resources must be allocated among multiple tasks. Researchers have proposed both domain-specific, for example, spatial versus verbal processing resources, and domain general cognitive resources. In the present research, we investigated whether a spatial puzzle task performed simultaneously with a verbal recall task would impair performance in either task or both tasks, compared to performance on the tasks individually. As hypothesized, a reduction in word recall was found when dual-tasking, though performance on the puzzle task did not significantly differ between the single- and dual-task conditions. This is consistent, in part, with both a general resource theory and a Multiple Resource Theory, but further work is required to better understand the cognitive processing system. The employment of the recall task in the dual-task paradigm with a variety of secondary tasks will help to continue mapping out the specificity (or lack thereof) of cognitive resources utilized in various mental and physical tasks.

A Computational/Experimental Platform for Investigating Three-Dimensional Puzzle Solving of Comminuted Articular Fractures

PubMed Central

Thomas, Thaddeus P.; Anderson, Donald D.; Willis, Andrew R.; Liu, Pengcheng; Frank, Matthew C.; Marsh, J. Lawrence; Brown, Thomas D.

2011-01-01

Reconstructing highly comminuted articular fractures poses a difficult surgical challenge, akin to solving a complicated three-dimensional (3D) puzzle. Pre-operative planning using CT is critically important, given the desirability of less invasive surgical approaches. The goal of this work is to advance 3D puzzle solving methods toward use as a pre-operative tool for reconstructing these complex fractures. Methodology for generating typical fragmentation/dispersal patterns was developed. Five identical replicas of human distal tibia anatomy, were machined from blocks of high-density polyetherurethane foam (bone fragmentation surrogate), and were fractured using an instrumented drop tower. Pre- and post-fracture geometries were obtained using laser scans and CT. A semi-automatic virtual reconstruction computer program aligned fragment native (non-fracture) surfaces to a pre-fracture template. The tibias were precisely reconstructed with alignment accuracies ranging from 0.03-0.4mm. This novel technology has potential to significantly enhance surgical techniques for reconstructing comminuted intra-articular fractures, as illustrated for a representative clinical case. PMID:20924863

Rotational seismology

USGS Publications Warehouse

Lee, William H K.

2016-01-01

Rotational seismology is an emerging study of all aspects of rotational motions induced by earthquakes, explosions, and ambient vibrations. It is of interest to several disciplines, including seismology, earthquake engineering, geodesy, and earth-based detection of Einstein’s gravitation waves.Rotational effects of seismic waves, together with rotations caused by soil–structure interaction, have been observed for centuries (e.g., rotated chimneys, monuments, and tombstones). Figure 1a shows the rotated monument to George Inglis observed after the 1897 Great Shillong earthquake. This monument had the form of an obelisk rising over 19 metres high from a 4 metre base. During the earthquake, the top part broke off and the remnant of some 6 metres rotated about 15° relative to the base. The study of rotational seismology began only recently when sensitive rotational sensors became available due to advances in aeronautical and astronomical instrumentations.

An Interactive 3D Virtual Anatomy Puzzle for Learning and Simulation - Initial Demonstration and Evaluation.

PubMed

Messier, Erik; Wilcox, Jascha; Dawson-Elli, Alexander; Diaz, Gabriel; Linte, Cristian A

2016-01-01

To inspire young students (grades 6-12) to become medical practitioners and biomedical engineers, it is necessary to expose them to key concepts of the field in a way that is both exciting and informative. Recent advances in medical image acquisition, manipulation, processing, visualization, and display have revolutionized the approach in which the human body and internal anatomy can be seen and studied. It is now possible to collect 3D, 4D, and 5D medical images of patient specific data, and display that data to the end user using consumer level 3D stereoscopic display technology. Despite such advancements, traditional 2D modes of content presentation such as textbooks and slides are still the standard didactic equipment used to teach young students anatomy. More sophisticated methods of display can help to elucidate the complex 3D relationships between structures that are so often missed when viewing only 2D media, and can instill in students an appreciation for the interconnection between medicine and technology. Here we describe the design, implementation, and preliminary evaluation of a 3D virtual anatomy puzzle dedicated to helping users learn the anatomy of various organs and systems by manipulating 3D virtual data. The puzzle currently comprises several components of the human anatomy and can be easily extended to include additional organs and systems. The 3D virtual anatomy puzzle game was implemented and piloted using three display paradigms - a traditional 2D monitor, a 3D TV with active shutter glass, and the DK2 version Oculus Rift, as well as two different user interaction devices - a space mouse and traditional keyboard controls.

Enhancing the Understanding of Government and Nonprofit Accounting with THE PUZZLE GAME: A Pilot Study

ERIC Educational Resources Information Center

Elson, Raymond J.; Ostapski, S. Andrew; O'Callaghan, Susanne; Walker, John P.

2012-01-01

Nontraditional teaching aids such as crossword puzzles have been successfully used in the classroom to enhance student learning. Government and nonprofit accounting is a confusing course for students since it has strange terminologies and contradicts the accounting concepts learned in other courses. As such, it is an ideal course for a…

RNA-Puzzles Round II: assessment of RNA structure prediction programs applied to three large RNA structures

PubMed Central

Miao, Zhichao; Adamiak, Ryszard W.; Blanchet, Marc-Frédérick; Boniecki, Michal; Bujnicki, Janusz M.; Chen, Shi-Jie; Cheng, Clarence; Chojnowski, Grzegorz; Chou, Fang-Chieh; Cordero, Pablo; Cruz, José Almeida; Ferré-D'Amaré, Adrian R.; Das, Rhiju; Ding, Feng; Dokholyan, Nikolay V.; Dunin-Horkawicz, Stanislaw; Kladwang, Wipapat; Krokhotin, Andrey; Lach, Grzegorz; Magnus, Marcin; Major, François; Mann, Thomas H.; Masquida, Benoît; Matelska, Dorota; Meyer, Mélanie; Peselis, Alla; Popenda, Mariusz; Purzycka, Katarzyna J.; Serganov, Alexander; Stasiewicz, Juliusz; Szachniuk, Marta; Tandon, Arpit; Tian, Siqi; Wang, Jian; Xiao, Yi; Xu, Xiaojun; Zhang, Jinwei; Zhao, Peinan; Zok, Tomasz; Westhof, Eric

2015-01-01

This paper is a report of a second round of RNA-Puzzles, a collective and blind experiment in three-dimensional (3D) RNA structure prediction. Three puzzles, Puzzles 5, 6, and 10, represented sequences of three large RNA structures with limited or no homology with previously solved RNA molecules. A lariat-capping ribozyme, as well as riboswitches complexed to adenosylcobalamin and tRNA, were predicted by seven groups using RNAComposer, ModeRNA/SimRNA, Vfold, Rosetta, DMD, MC-Fold, 3dRNA, and AMBER refinement. Some groups derived models using data from state-of-the-art chemical-mapping methods (SHAPE, DMS, CMCT, and mutate-and-map). The comparisons between the predictions and the three subsequently released crystallographic structures, solved at diffraction resolutions of 2.5–3.2 Å, were carried out automatically using various sets of quality indicators. The comparisons clearly demonstrate the state of present-day de novo prediction abilities as well as the limitations of these state-of-the-art methods. All of the best prediction models have similar topologies to the native structures, which suggests that computational methods for RNA structure prediction can already provide useful structural information for biological problems. However, the prediction accuracy for non-Watson–Crick interactions, key to proper folding of RNAs, is low and some predicted models had high Clash Scores. These two difficulties point to some of the continuing bottlenecks in RNA structure prediction. All submitted models are available for download at http://ahsoka.u-strasbg.fr/rnapuzzles/. PMID:25883046

The Puzzle of HCN in Comets: Is it both a Product and a Primary Species?

NASA Astrophysics Data System (ADS)

Mumma, Michael J.; Bonev, Boncho P.; Charnley, Steven B.; Cordiner, Martin A.; DiSanti, Michael A.; Gibb, Erika L.; Magee-Sauer, Karen; Paganini, Lucas; Villanueva, Geronimo L.

2014-11-01

Hydrogen cyanide has long been regarded as a primary volatile in comets, stemming from its presence in dense molecular cloud cores and its supposed storage in the cometary nucleus. Here, we examine the observational evidence for and against that hypothesis, and argue that HCN may also result from near-nucleus chemical reactions in the coma. The distinction (product vs. primary species) is important for multiple reasons: 1. HCN is often used as a proxy for water when the dominant species (H2O) is not available for simultaneous measurement, as at radio wavelengths. 2. HCN is one of the few volatile carriers of nitrogen accessible to remote sensing. If HCN is mainly a product species, its precursor becomes the more important metric for compiling a taxonomic classification based on nitrogen chemistry. 3. The stereoisomer HNC is now confirmed as a product species. Could reaction of a primary precursor (X-CN) with a hydrocarbon co-produce both HNC and HCN? 4. The production rate for CN greatly exceeds that of HCN in some comets, demonstrating the presence of another (more important) precursor of CN. Several puzzling lines of evidence raise issues about the origin of HCN: a. The production rates of HCN measured through rotational (radio) and vibrational (infrared) spectroscopy agree in some comets - in others the infrared rate exceeds the radio rate substantially. b. With its strong dipole moment and H-bonding character, HCN should be linked more strongly in the nuclear ice to other molecules with similar properties (H2O, CH3OH), but instead its spatial release in some comets seems strongly coupled to volatiles that lack a dipole moment and thus do not form H-bonds (methane, ethane). c. The nucleus-centered rotational temperatures measured for H2O and other species (C2H6, CH3OH) usually agree within error, but those for HCN are often slightly smaller. d. In comet ISON, ALMA maps of HCN and the dust continuum show a slight displacement 80 km) in the centroids. We will

Set selection dynamical system neural networks with partial memories, with applications to Sudoku and KenKen puzzles.

PubMed

Boreland, B; Clement, G; Kunze, H

2015-08-01

After reviewing set selection and memory model dynamical system neural networks, we introduce a neural network model that combines set selection with partial memories (stored memories on subsets of states in the network). We establish that feasible equilibria with all states equal to ± 1 correspond to answers to a particular set theoretic problem. We show that KenKen puzzles can be formulated as a particular case of this set theoretic problem and use the neural network model to solve them; in addition, we use a similar approach to solve Sudoku. We illustrate the approach in examples. As a heuristic experiment, we use online or print resources to identify the difficulty of the puzzles and compare these difficulties to the number of iterations used by the appropriate neural network solver, finding a strong relationship. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of rotation on a rotating hot-wire sensor

NASA Technical Reports Server (NTRS)

Hah, C.; Lakshminarayana, B.

1978-01-01

An investigation was conducted to discern the effects of centrifugal and Coriolis forces on a rotating hot-wire. The probe was calibrated in a wind tunnel as well as in a rotating mode. The effect of rotation was found to be negligibly small. A small change in cold resistance (1.5%) was observed in the rotating wire. The rotation seems to have a negligible effect on the fluid mechanics, heat transfer and material characteristics of the wire. This is a significant conclusion in view of the potential application of the hot-wire probe in a rotating passage (such as turbomachinery).

Instructional Media Production for Early Childhood Education: A. B. C. Jig-Saw Puzzle, a Model

ERIC Educational Resources Information Center

Yusuf, Mudashiru Olalere; Olanrewaju, Olatayo Solomon; Soetan, Aderonke K.

2015-01-01

In this paper, a. b. c. jig-saw puzzle was produced for early childhood education using local materials. This study was a production based type of research, to serve as a supplemental or total learning resource. Its production followed four phases of development referred to as information, design, production and evaluation. The storyboard cards,…

The puzzle box as a simple and efficient behavioral test for exploring impairments of general cognition and executive functions in mouse models of schizophrenia.

PubMed

Ben Abdallah, Nada M-B; Fuss, Johannes; Trusel, Massimo; Galsworthy, Michael J; Bobsin, Kristin; Colacicco, Giovanni; Deacon, Robert M J; Riva, Marco A; Kellendonk, Christoph; Sprengel, Rolf; Lipp, Hans-Peter; Gass, Peter

2011-01-01

Deficits in executive functions are key features of schizophrenia. Rodent behavioral paradigms used so far to find animal correlates of such deficits require extensive effort and time. The puzzle box is a problem-solving test in which mice are required to complete escape tasks of increasing difficulty within a limited amount of time. Previous data have indicated that it is a quick but highly reliable test of higher-order cognitive functioning. We evaluated the use of the puzzle box to explore executive functioning in five different mouse models of schizophrenia: mice with prefrontal cortex and hippocampus lesions, mice treated sub-chronically with the NMDA-receptor antagonist MK-801, mice constitutively lacking the GluA1 subunit of AMPA-receptors, and mice over-expressing dopamine D2 receptors in the striatum. All mice displayed altered executive functions in the puzzle box, although the nature and extent of the deficits varied between the different models. Deficits were strongest in hippocampus-lesioned and GluA1 knockout mice, while more subtle deficits but specific to problem solving were found in the medial prefrontal-lesioned mice, MK-801-treated mice, and in mice with striatal overexpression of D2 receptors. Data from this study demonstrate the utility of the puzzle box as an effective screening tool for executive functions in general and for schizophrenia mouse models in particular. Published by Elsevier Inc.

Rotational evolution of slow-rotator sequence stars

NASA Astrophysics Data System (ADS)

Lanzafame, A. C.; Spada, F.

2015-12-01

Context. The observed relationship between mass, age and rotation in open clusters shows the progressive development of a slow-rotator sequence among stars possessing a radiative interior and a convective envelope during their pre-main sequence and main-sequence evolution. After 0.6 Gyr, most cluster members of this type have settled on this sequence. Aims: The observed clustering on this sequence suggests that it corresponds to some equilibrium or asymptotic condition that still lacks a complete theoretical interpretation, and which is crucial to our understanding of the stellar angular momentum evolution. Methods: We couple a rotational evolution model, which takes internal differential rotation into account, with classical and new proposals for the wind braking law, and fit models to the data using a Monte Carlo Markov chain (MCMC) method tailored to the problem at hand. We explore to what extent these models are able to reproduce the mass and time dependence of the stellar rotational evolution on the slow-rotator sequence. Results: The description of the evolution of the slow-rotator sequence requires taking the transfer of angular momentum from the radiative core to the convective envelope into account. We find that, in the mass range 0.85-1.10 M⊙, the core-envelope coupling timescale for stars in the slow-rotator sequence scales as M-7.28. Quasi-solid body rotation is achieved only after 1-2 Gyr, depending on stellar mass, which implies that observing small deviations from the Skumanich law (P ∝ √{t}) would require period data of older open clusters than is available to date. The observed evolution in the 0.1-2.5 Gyr age range and in the 0.85-1.10 M⊙ mass range is best reproduced by assuming an empirical mass dependence of the wind angular momentum loss proportional to the convective turnover timescale and to the stellar moment of inertia. Period isochrones based on our MCMC fit provide a tool for inferring stellar ages of solar-like main

Children with Praderwilli Syndrome Vs. Williams Syndrome: Indirect Effects on Parents during a Jigsaw Puzzle Task

ERIC Educational Resources Information Center

Ly, T. M.; Hodapp, R. M.

2005-01-01

Background: Genetic disorders predispose individuals to exhibit characteristic behaviours, which in turn elicit particular behaviours from others. In response to the strength of Prader?Willi syndrome (PWS) and weakness of Williams syndrome (WS) in visual-spatial tasks such as jigsaw puzzles, parents' behaviours can be affected by their child's…

Rotational elasticity

NASA Astrophysics Data System (ADS)

Vassiliev, Dmitri

2017-04-01

We consider an infinite three-dimensional elastic continuum whose material points experience no displacements, only rotations. This framework is a special case of the Cosserat theory of elasticity. Rotations of material points are described mathematically by attaching to each geometric point an orthonormal basis that gives a field of orthonormal bases called the coframe. As the dynamical variables (unknowns) of our theory, we choose the coframe and a density. We write down the general dynamic variational functional for our rotational theory of elasticity, assuming our material to be physically linear but the kinematic model geometrically nonlinear. Allowing geometric nonlinearity is natural when dealing with rotations because rotations in dimension three are inherently nonlinear (rotations about different axes do not commute) and because there is no reason to exclude from our study large rotations such as full turns. The main result of the talk is an explicit construction of a class of time-dependent solutions that we call plane wave solutions; these are travelling waves of rotations. The existence of such explicit closed-form solutions is a non-trivial fact given that our system of Euler-Lagrange equations is highly nonlinear. We also consider a special case of our rotational theory of elasticity which in the stationary setting (harmonic time dependence and arbitrary dependence on spatial coordinates) turns out to be equivalent to a pair of massless Dirac equations. The talk is based on the paper [1]. [1] C.G.Boehmer, R.J.Downes and D.Vassiliev, Rotational elasticity, Quarterly Journal of Mechanics and Applied Mathematics, 2011, vol. 64, p. 415-439. The paper is a heavily revised version of preprint https://arxiv.org/abs/1008.3833

Probabilistic interpretation of Peelle's pertinent puzzle and its resolution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hanson, Kenneth M.; Kawano, T.; Talou, P.

2004-01-01

Peelle's Pertinent Puzzle (PPP) states a seemingly plausible set of measurements with their covariance matrix, which produce an implausible answer. To answer the PPP question, we describe a reasonable experimental situation that is consistent with the PPP solution. The confusion surrounding the PPP arises in part because of its imprecise statement, which permits to a variety of interpretations and resulting answers, some of which seem implausible. We emphasize the importance of basing the analysis on an unambiguous probabilistic model that reflects the experimental situation. We present several different models of how the measurements quoted in the PPP problem could bemore » obtained, and interpret their solution in terms of a detailed probabilistic analysis. We suggest a probabilistic approach to handling uncertainties about which model to use.« less

Probabilistic Interpretation of Peelle's Pertinent Puzzle and its Resolution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hanson, Kenneth M.; Kawano, Toshihiko; Talou, Patrick

2005-05-24

Peelle's Pertinent Puzzle (PPP) states a seemingly plausible set of measurements with their covariance matrix, which produce an implausible answer. To answer the PPP question, we describe a reasonable experimental situation that is consistent with the PPP solution. The confusion surrounding the PPP arises in part because of its imprecise statement, which permits to a variety of interpretations and resulting answers, some of which seem implausible. We emphasize the importance of basing the analysis on an unambiguous probabilistic model that reflects the experimental situation. We present several different models of how the measurements quoted in the PPP problem could bemore » obtained, and interpret their solution in terms of a detailed probabilistic analysis. We suggest a probabilistic approach to handling uncertainties about which model to use.« less

Sirtuin Activation: A Role for Plasma Membrane in the Cell Growth Puzzle

PubMed Central

2013-01-01

For more than 20 years, the observation that impermeable oxidants can stimulate cell growth has not been satisfactorily explained. The discovery of sirtuins provides a logical answer to the puzzle. The NADH-dependent transplasma membrane electron transport system, which is stimulated by growth factors and interventions such as calorie restriction, can transfer electrons to external acceptors and protect against stress-induced apoptosis. We hypothesize that the activation of plasma membrane electron transport contributes to the cytosolic NAD+ pool required for sirtuin to activate transcription factors necessary for cell growth and survival. PMID:23033342

Sirtuin activation: a role for plasma membrane in the cell growth puzzle.

PubMed

Crane, Frederick L; Navas, Plácido; Low, Hans; Sun, Iris L; de Cabo, Rafael

2013-04-01

For more than 20 years, the observation that impermeable oxidants can stimulate cell growth has not been satisfactorily explained. The discovery of sirtuins provides a logical answer to the puzzle. The NADH-dependent transplasma membrane electron transport system, which is stimulated by growth factors and interventions such as calorie restriction, can transfer electrons to external acceptors and protect against stress-induced apoptosis. We hypothesize that the activation of plasma membrane electron transport contributes to the cytosolic NAD(+) pool required for sirtuin to activate transcription factors necessary for cell growth and survival.

BOOK REVIEW: Rotation and Accretion Powered Pulsars

NASA Astrophysics Data System (ADS)

Kaspi, V. M.

2008-03-01

ever wanted to know about pulsars but were afraid to ask. Chapter 1 begins a brief and interesting account of the discovery of pulsars, followed by an overview of the rotation-powered and accretion-powered populations. The following four chapters are fairly detailed and reasonably quantitative descriptions of neutron star interiors. This is no easy feat, given that a description of the physics of neutron stars demands a deep understanding of all major physical forces, and must include general relativity as well as detailed particle physics. The historical notes at the beginning of Chapter 2 are particularly fascinating, recounting the path to today's understanding of neutron stars in very interesting detail. Chapter 7 presents rotation-powered pulsar radio properties, and a nice description of pulsar timing, including relativistic and non-relativistic binaries and GR tests. The remaining chapters tackle a variety of topics including binary evolution, superfluidity, accretion-powered pulsar properties, magnetospheres and emission mechanisms, magnetic fields, spin evolution and strange stars. The coverage is somewhat uneven, with the strange star chapter, for example, an obvious afterthought. The utility of an encyclopedia lies in its breadth and in how up-to-date it is. Although admirable in its intentions, the Ghosh book does omit some major pulsar topics. This book leaves the impression that rotation-powered pulsars produce only radio emission; hardly (if at all) mentioned is the vast literature on their infrared, optical, and even more importantly, x-ray and gamma-ray emission, the latter being far more relevant to the pulsar 'machine' than the energetically puny radio output. Also absent are pulsar winds; this is particularly puzzling given both the lovely wind nebula that graces the book's cover, and the central role the wind plays as primary sink of the rotation power. One of the most actively pursued topics in pulsar astrophysics in the past decade, magnetars

Piecing together the puzzle: Improving event content coverage for real-time sub-event detection using adaptive microblog crawling

PubMed Central

Tokarchuk, Laurissa; Wang, Xinyue; Poslad, Stefan

2017-01-01

In an age when people are predisposed to report real-world events through their social media accounts, many researchers value the benefits of mining user generated content from social media. Compared with the traditional news media, social media services, such as Twitter, can provide more complete and timely information about the real-world events. However events are often like a puzzle and in order to solve the puzzle/understand the event, we must identify all the sub-events or pieces. Existing Twitter event monitoring systems for sub-event detection and summarization currently typically analyse events based on partial data as conventional data collection methodologies are unable to collect comprehensive event data. This results in existing systems often being unable to report sub-events in real-time and often in completely missing sub-events or pieces in the broader event puzzle. This paper proposes a Sub-event detection by real-TIme Microblog monitoring (STRIM) framework that leverages the temporal feature of an expanded set of news-worthy event content. In order to more comprehensively and accurately identify sub-events this framework first proposes the use of adaptive microblog crawling. Our adaptive microblog crawler is capable of increasing the coverage of events while minimizing the amount of non-relevant content. We then propose a stream division methodology that can be accomplished in real time so that the temporal features of the expanded event streams can be analysed by a burst detection algorithm. In the final steps of the framework, the content features are extracted from each divided stream and recombined to provide a final summarization of the sub-events. The proposed framework is evaluated against traditional event detection using event recall and event precision metrics. Results show that improving the quality and coverage of event contents contribute to better event detection by identifying additional valid sub-events. The novel combination of

Piecing together the puzzle: Improving event content coverage for real-time sub-event detection using adaptive microblog crawling.

PubMed

Tokarchuk, Laurissa; Wang, Xinyue; Poslad, Stefan

2017-01-01

In an age when people are predisposed to report real-world events through their social media accounts, many researchers value the benefits of mining user generated content from social media. Compared with the traditional news media, social media services, such as Twitter, can provide more complete and timely information about the real-world events. However events are often like a puzzle and in order to solve the puzzle/understand the event, we must identify all the sub-events or pieces. Existing Twitter event monitoring systems for sub-event detection and summarization currently typically analyse events based on partial data as conventional data collection methodologies are unable to collect comprehensive event data. This results in existing systems often being unable to report sub-events in real-time and often in completely missing sub-events or pieces in the broader event puzzle. This paper proposes a Sub-event detection by real-TIme Microblog monitoring (STRIM) framework that leverages the temporal feature of an expanded set of news-worthy event content. In order to more comprehensively and accurately identify sub-events this framework first proposes the use of adaptive microblog crawling. Our adaptive microblog crawler is capable of increasing the coverage of events while minimizing the amount of non-relevant content. We then propose a stream division methodology that can be accomplished in real time so that the temporal features of the expanded event streams can be analysed by a burst detection algorithm. In the final steps of the framework, the content features are extracted from each divided stream and recombined to provide a final summarization of the sub-events. The proposed framework is evaluated against traditional event detection using event recall and event precision metrics. Results show that improving the quality and coverage of event contents contribute to better event detection by identifying additional valid sub-events. The novel combination of

Rotating superconductor magnet for producing rotating lobed magnetic field lines

DOEpatents

Hilal, Sadek K.; Sampson, William B.; Leonard, Edward F.

1978-01-01

This invention provides a rotating superconductor magnet for producing a rotating lobed magnetic field, comprising a cryostat; a superconducting magnet in the cryostat having a collar for producing a lobed magnetic field having oppositely directed adjacent field lines; rotatable support means for selectively rotating the superconductor magnet; and means for energizing the superconductor magnet.

Ego-rotation and object-rotation in major depressive disorder.

PubMed

Chen, Jiu; Yang, Laiqi; Ma, Wentao; Wu, Xingqu; Zhang, Yan; Wei, Dunhong; Liu, Guangxiong; Deng, Zihe; Hua, Zhen; Jia, Ting

2013-08-30

Mental rotation (MR) performance provides a direct insight into a prototypical higher-level visuo-spatial cognitive operation. Previous studies suggest that progressive slowing with an increasing angle of orientation indicates a specific wing of object-based mental transformations in the psychomotor retardation that occurs in major depressive disorder (MDD). It is still not known, however, whether the ability of object-rotation is associated with the ability of ego-rotation in MDD. The present study was designed to investigate the level of impairment of mental transformation abilities in MDD. For this purpose we tested 33 MDD (aged 18-52 years, 16 women) and 30 healthy control subjects (15 women, age and education matched) by evaluating the performance of MDD subjects with regard to ego-rotation and object-rotation tasks. First, MDD subjects were significantly slower and made more errors than controls in mentally rotating hands and letters. Second, MDD and control subjects displayed the same pattern of response times to stimuli at various orientations in the letter task but not the hand task. Third, in particular, MDD subjects were significantly slower and made more errors during the mental transformation of hands than letters relative to control subjects and were significantly slower and made more errors in physiologically impossible angles than physiologically possible angles in the mental rotation hand task. In conclusion, MDD subjects present with more serious mental rotation deficits specific to the hand than the letter task. Importantly, deficits were more present during the mental transformation in outward rotation angles, thus suggesting that the mental imagery for hands and letters relies on different processing mechanisms which suggest a module that is more complex for the processing of human hands than for letters during mental rotation tasks. Our study emphasises the necessity of distinguishing different levels of impairment of action in MDD subjects

Hydrodynamic interactions between a self-rotation rotator and passive particles

NASA Astrophysics Data System (ADS)

Ouyang, Zhenyu; Lin, Jian-Zhong; Ku, Xiaoke

2017-10-01

In this paper, we numerically investigate the hydrodynamic interaction between a self-rotation rotator and passive particles in a two-dimensional confined cavity at two typical Reynolds numbers according to the different flow features. Both the fluid-particle interaction and particle-particle interaction through fluid media are taken into consideration. The results show that from the case of a rotator and one passive particle to the case of a rotator and two passive particles, the system becomes much more complex because the relative displacement between the rotator and the passive particles and the velocity of passive particles are strongly dependent on the Reynolds number and the initial position of passive particles. For the system of two particles, the passive particle gradually departs from the rotator although its relative displacement to the rotator exhibits a periodic oscillation at the lower Reynolds number. Furthermore, the relative distance between the two particles and the rotator's rotational frequency are responsible for the oscillation amplitude and frequency of the passive particle's velocity. For the system of three particles, the passive particle's velocities exhibit a superposition of a large amplitude oscillation and a small amplitude oscillation at the lower Reynolds number, and the large amplitude oscillation will disappear at the higher Reynolds number. The change of the included angle of the two passive particles is dependent on the initial positions of the passive particles at the lower Reynolds number, whereas the included angle of the two passive particles finally approaches a fixed value at the higher Reynolds number. It is interesting that the two passive particles periodically approach and depart from each other when the included angle is not equal to π, while all the three particles (including the rotator) keep the positions in a straight line when the included angle is equal to π because the interference between two passive

KnowledgePuzzle: A Browsing Tool to Adapt the Web Navigation Process to the Learner's Mental Model

ERIC Educational Resources Information Center

AlAgha, Iyad

2012-01-01

This article presents KnowledgePuzzle, a browsing tool for knowledge construction from the web. It aims to adapt the structure of web content to the learner's information needs regardless of how the web content is originally delivered. Learners are provided with a meta-cognitive space (e.g., a concept mapping tool) that enables them to plan…

Peelle's pertinent puzzle using the Monte Carlo technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kawano, Toshihiko; Talou, Patrick; Burr, Thomas

2009-01-01

We try to understand the long-standing problem of the Peelle's Pertinent Puzzle (PPP) using the Monte Carlo technique. We allow the probability density functions to be any kind of form to assume the impact of distribution, and obtain the least-squares solution directly from numerical simulations. We found that the standard least squares method gives the correct answer if a weighting function is properly provided. Results from numerical simulations show that the correct answer of PPP is 1.1 {+-} 0.25 if the common error is multiplicative. The thought-provoking answer of 0.88 is also correct, if the common error is additive, andmore » if the error is proportional to the measured values. The least squares method correctly gives us the most probable case, where the additive component has a negative value. Finally, the standard method fails for PPP due to a distorted (non Gaussian) joint distribution.« less

What cognitive strategies do orangutans (Pongo pygmaeus) use to solve a trial-unique puzzle-tube task incorporating multiple obstacles?

PubMed

Tecwyn, Emma C; Thorpe, Susannah K S; Chappell, Jackie

2012-01-01

Apparently sophisticated behaviour during problem-solving is often the product of simple underlying mechanisms, such as associative learning or the use of procedural rules. These and other more parsimonious explanations need to be eliminated before higher-level cognitive processes such as causal reasoning or planning can be inferred. We presented three Bornean orangutans with 64 trial-unique configurations of a puzzle-tube to investigate whether they were able to consider multiple obstacles in two alternative paths, and subsequently choose the correct direction in which to move a reward in order to retrieve it. We were particularly interested in how subjects attempted to solve the task, namely which behavioural strategies they could have been using, as this is how we may begin to elucidate the cognitive mechanisms underpinning their choices. To explore this, we simulated performance outcomes across the 64 trials for various procedural rules and rule combinations that subjects may have been using based on the configuration of different obstacles. Two of the three subjects solved the task, suggesting that they were able to consider at least some of the obstacles in the puzzle-tube before executing action to retrieve the reward. This is impressive compared with the past performances of great apes on similar, arguably less complex tasks. Successful subjects may have been using a heuristic rule combination based on what they deemed to be the most relevant cue (the configuration of the puzzle-tube ends), which may be a cognitively economical strategy.

Solving the puzzle of pluripotent stem cell-derived cardiomyocyte maturation: piece by piece.

PubMed

Lundy, David J; Lee, Desy S; Hsieh, Patrick C H

2017-03-01

There is a growing need for in vitro models which can serve as platforms for drug screening and basic research. Human adult cardiomyocytes cannot be readily obtained or cultured, and so pluripotent stem cell-derived cardiomyocytes appear to be an attractive option. Unfortunately, these cells are structurally and functionally immature-more comparable to foetal cardiomyocytes than adult. A recent study by Ruan et al ., provides new insights into accelerating the maturation process and takes us a step closer to solving the puzzle of pluripotent stem cell-derived cardiomyocyte maturation.

In touch with mental rotation: interactions between mental and tactile rotations and motor responses.

PubMed

Lohmann, Johannes; Rolke, Bettina; Butz, Martin V

2017-04-01

Although several process models have described the cognitive processing stages that are involved in mentally rotating objects, the exact nature of the rotation process itself remains elusive. According to embodied cognition, cognitive functions are deeply grounded in the sensorimotor system. We thus hypothesized that modal rotation perceptions should influence mental rotations. We conducted two studies in which participants had to judge if a rotated letter was visually presented canonically or mirrored. Concurrently, participants had to judge if a tactile rotation on their palm changed direction during the trial. The results show that tactile rotations can systematically influence mental rotation performance in that same rotations are favored. In addition, the results show that mental rotations produce a response compatibility effect: clockwise mental rotations facilitate responses to the right, while counterclockwise mental rotations facilitate responses to the left. We conclude that the execution of mental rotations activates cognitive mechanisms that are also used to perceive rotations in different modalities and that are associated with directional motor control processes.

Predictors of human rotation.

PubMed

Stochl, Jan; Croudace, Tim

2013-01-01

Why some humans prefer to rotate clockwise rather than anticlockwise is not well understood. This study aims to identify the predictors of the preferred rotation direction in humans. The variables hypothesised to influence rotation preference include handedness, footedness, sex, brain hemisphere lateralisation, and the Coriolis effect (which results from geospatial location on the Earth). An online questionnaire allowed us to analyse data from 1526 respondents in 97 countries. Factor analysis showed that the direction of rotation should be studied separately for local and global movements. Handedness, footedness, and the item hypothesised to measure brain hemisphere lateralisation are predictors of rotation direction for both global and local movements. Sex is a predictor of the direction of global rotation movements but not local ones, and both sexes tend to rotate clockwise. Geospatial location does not predict the preferred direction of rotation. Our study confirms previous findings concerning the influence of handedness, footedness, and sex on human rotation; our study also provides new insight into the underlying structure of human rotation movements and excludes the Coriolis effect as a predictor of rotation.

The puzzle of Muslim advantage in child survival in India.

PubMed

Bhalotra, Sonia; Valente, Christine; van Soest, Arthur

2010-03-01

The socioeconomic status of Indian Muslims is, on average, considerably lower than that of upper-caste Hindus. Muslims nevertheless exhibit substantially higher child survival rates, and have done for decades. This paper analyses this seeming puzzle. A decomposition of the survival differential confirms that some compositional effects favour Muslims but that, overall, differences in characteristics and especially the Muslim deficit in parental education predict a Muslim disadvantage. The results of this study contribute to a recent literature that debates the importance of socioeconomic status (SES) in determining health and survival. They augment a growing literature on the role of religion or culture as encapsulating important unobservable behaviours or endowments that influence health, indeed, enough to reverse the SES gradient that is commonly observed. Copyright 2009 Elsevier B.V. All rights reserved.

Rotator cuff problems

MedlinePlus

... smooth layer) lining these tendons. A rotator cuff tear occurs when one of the tendons is torn ... Poor posture over many years Aging Rotator cuff tears TEARS Rotator cuff tears may occur in two ...

The rapid formation of a large rotating disk galaxy three billion years after the Big Bang.

PubMed

Genzel, R; Tacconi, L J; Eisenhauer, F; Schreiber, N M Förster; Cimatti, A; Daddi, E; Bouché, N; Davies, R; Lehnert, M D; Lutz, D; Nesvadba, N; Verma, A; Abuter, R; Shapiro, K; Sternberg, A; Renzini, A; Kong, X; Arimoto, N; Mignoli, M

2006-08-17

Observations and theoretical simulations have established a framework for galaxy formation and evolution in the young Universe. Galaxies formed as baryonic gas cooled at the centres of collapsing dark-matter haloes; mergers of haloes and galaxies then led to the hierarchical build-up of galaxy mass. It remains unclear, however, over what timescales galaxies were assembled and when and how bulges and disks--the primary components of present-day galaxies--were formed. It is also puzzling that the most massive galaxies were more abundant and were forming stars more rapidly at early epochs than expected from models. Here we report high-angular-resolution observations of a representative luminous star-forming galaxy when the Universe was only 20% of its current age. A large and massive rotating protodisk is channelling gas towards a growing central stellar bulge hosting an accreting massive black hole. The high surface densities of gas, the high rate of star formation and the moderately young stellar ages suggest rapid assembly, fragmentation and conversion to stars of an initially very gas-rich protodisk, with no obvious evidence for a major merger.

Non-synchronous rotating damping effects in gyroscopic rotating systems

NASA Astrophysics Data System (ADS)

Brusa, Eugenio; Zolfini, Giacomo

2005-03-01

The effects of non-synchronous rotating damping, i.e., of energy dissipation in elements rotating at a speed different from that of the main rotor, on the dynamic behaviour of the latter have been already studied in a previous paper (J. Rotating Machinery 6 (6) (2000)) for the case of non-gyroscopic rotating systems. A planar model, namely the Jeffcott's rotor, was used. The present study is aimed at investigating, through analytical and numerical models, the behaviour of rotors having a non-negligible gyroscopic effect. The parameters of the system affecting the dynamic stability are identified and the threshold of instability is then computed. A sort of map of stability is provided to allow mechanical engineers predicting possibile range of instability for forward and backward whirling motions. An experimental validation on a simple test rig is presented in order to show the effectiveness of the proposed stability analysis. Non-synchronous rotating damping is implemented by using a non-synchronous electromagnetic damper based on eddy currents.

RNA-Puzzles: A CASP-like evaluation of RNA three-dimensional structure prediction

PubMed Central

Cruz, José Almeida; Blanchet, Marc-Frédérick; Boniecki, Michal; Bujnicki, Janusz M.; Chen, Shi-Jie; Cao, Song; Das, Rhiju; Ding, Feng; Dokholyan, Nikolay V.; Flores, Samuel Coulbourn; Huang, Lili; Lavender, Christopher A.; Lisi, Véronique; Major, François; Mikolajczak, Katarzyna; Patel, Dinshaw J.; Philips, Anna; Puton, Tomasz; Santalucia, John; Sijenyi, Fredrick; Hermann, Thomas; Rother, Kristian; Rother, Magdalena; Serganov, Alexander; Skorupski, Marcin; Soltysinski, Tomasz; Sripakdeevong, Parin; Tuszynska, Irina; Weeks, Kevin M.; Waldsich, Christina; Wildauer, Michael; Leontis, Neocles B.; Westhof, Eric

2012-01-01

We report the results of a first, collective, blind experiment in RNA three-dimensional (3D) structure prediction, encompassing three prediction puzzles. The goals are to assess the leading edge of RNA structure prediction techniques; compare existing methods and tools; and evaluate their relative strengths, weaknesses, and limitations in terms of sequence length and structural complexity. The results should give potential users insight into the suitability of available methods for different applications and facilitate efforts in the RNA structure prediction community in ongoing efforts to improve prediction tools. We also report the creation of an automated evaluation pipeline to facilitate the analysis of future RNA structure prediction exercises. PMID:22361291

An Effective Method of Introducing the Periodic Table as a Crossword Puzzle at the High School Level

ERIC Educational Resources Information Center

Joag, Sushama D.

2014-01-01

A simple method to introduce the modern periodic table of elements at the high school level as a game of solving a crossword puzzle is presented here. A survey to test the effectiveness of this new method relative to the conventional method, involving use of a wall-mounted chart of the periodic table, was conducted on a convenience sample. This…

Induced Hyperon-Nucleon-Nucleon Interactions and the Hyperon Puzzle.

PubMed

Wirth, Roland; Roth, Robert

2016-10-28

We present the first ab initio calculations for p-shell hypernuclei including hyperon-nucleon-nucleon (YNN) contributions induced by a similarity renormalization group transformation of the initial hyperon-nucleon interaction. The transformation including the YNN terms conserves the spectrum of the Hamiltonian while drastically improving model-space convergence of the importance-truncated no-core model, allowing a precise extraction of binding and excitation energies. Results using a hyperon-nucleon interaction at leading order in chiral effective field theory for lower- to mid-p-shell hypernuclei show a good reproduction of experimental excitation energies while hyperon separation energies are typically overestimated. The induced YNN contributions are strongly repulsive and we show that they are related to a decoupling of the Σ hyperons from the hypernuclear system, i.e., a suppression of the Λ-Σ conversion terms in the Hamiltonian. This is linked to the so-called hyperon puzzle in neutron-star physics and provides a basic mechanism for the explanation of strong ΛNN three-baryon forces.

Estrogen, Angiogenesis, Immunity and Cell Metabolism: Solving the Puzzle.

PubMed

Trenti, Annalisa; Tedesco, Serena; Boscaro, Carlotta; Trevisi, Lucia; Bolego, Chiara; Cignarella, Andrea

2018-03-15

Estrogen plays an important role in the regulation of cardiovascular physiology and the immune system by inducing direct effects on multiple cell types including immune and vascular cells. Sex steroid hormones are implicated in cardiovascular protection, including endothelial healing in case of arterial injury and collateral vessel formation in ischemic tissue. Estrogen can exert potent modulation effects at all levels of the innate and adaptive immune systems. Their action is mediated by interaction with classical estrogen receptors (ERs), ERα and ERβ, as well as the more recently identified G-protein coupled receptor 30/G-protein estrogen receptor 1 (GPER1), via both genomic and non-genomic mechanisms. Emerging data from the literature suggest that estrogen deficiency in menopause is associated with an increased potential for an unresolved inflammatory status. In this review, we provide an overview through the puzzle pieces of how 17β-estradiol can influence the cardiovascular and immune systems.

Rotations

Treesearch

John R. Jones; Wayne D. Shepperd

1985-01-01

The rotation, in forestry, is the planned number of years between formation of a crop or stand and its final harvest at a specified stage of maturity (Ford-Robertson 1971). The rotation used for many species is the age of culmination of mean usable volume growth [net mean annual increment (MAI)]. At that age, usable volume divided by age reaches its highest level. That...

Cles: Etes-vous bon detective?; Enigmes grammaticales; Problemes policiers; Kidnapping (Keys: Are You a Good Detective?; Grammatical Puzzles; Detective Mysteries; Kidnapping).

ERIC Educational Resources Information Center

Debyser, Francis; And Others

1984-01-01

Four sets of French classroom activities are presented: a mystery whose clues include two postcard messages; three puzzles with grammar-related clues; a mystery contained in three comic strip frames; and the solving of a kidnapping mystery. (MSE)

Puzzle test: A tool for non-analytical clinical reasoning assessment.

PubMed

Monajemi, Alireza; Yaghmaei, Minoo

2016-01-01

Most contemporary clinical reasoning tests typically assess non-automatic thinking. Therefore, a test is needed to measure automatic reasoning or pattern recognition, which has been largely neglected in clinical reasoning tests. The Puzzle Test (PT) is dedicated to assess automatic clinical reasoning in routine situations. This test has been introduced first in 2009 by Monajemi et al in the Olympiad for Medical Sciences Students.PT is an item format that has gained acceptance in medical education, but no detailed guidelines exist for this test's format, construction and scoring. In this article, a format is described and the steps to prepare and administer valid and reliable PTs are presented. PT examines a specific clinical reasoning task: Pattern recognition. PT does not replace other clinical reasoning assessment tools. However, it complements them in strategies for assessing comprehensive clinical reasoning.

Rotation sensor switch

DOEpatents

Sevec, John B.

1978-01-01

A protective device to provide a warning if a piece of rotating machinery slows or stops comprises a pair of hinged weights disposed to rotate on a rotating shaft of the equipment. When the equipment is rotating, the weights remain in a plane essentially perpendicular to the shaft and constitute part of an electrical circuit that is open. When the shaft slows or stops, the weights are attracted to a pair of concentric electrically conducting disks disposed in a plane perpendicular to the shaft and parallel to the plane of the weights when rotating. A disk magnet attracts the weights to the electrically conducting plates and maintains the electrical contact at the plates to complete an electrical circuit that can then provide an alarm signal.

Rotation, differential rotation, and gyrochronology of active Kepler stars

NASA Astrophysics Data System (ADS)

Reinhold, Timo; Gizon, Laurent

2015-11-01

Context. In addition to the discovery of hundreds of exoplanets, the high-precision photometry from the CoRoT and Kepler satellites has led to measurements of surface rotation periods for tens of thousands of stars, which can potentially be used to infer stellar ages via gyrochronology. Aims: Our main goal is to derive ages of thousands of field stars using consistent rotation period measurements derived by different methods. Multiple rotation periods are interpreted as surface differential rotation (DR). We study the dependence of DR with rotation period and effective temperature. Methods: We reanalyze a previously studied sample of 24 124 Kepler stars using different approaches based on the Lomb-Scargle periodogram. Each quarter (Q1-Q14) is treated individually using a prewhitening approach. Additionally, the full time series and their different segments are analyzed. Results: For more than 18 500 stars our results are consistent with the rotation periods from McQuillan et al. (2014, ApJS, 211, 24). Of these, more than 12 300 stars show multiple significant peaks, which we interpret as DR. Dependencies of the DR with rotation period and effective temperature could be confirmed, e.g., the relative DR increases with rotation period. Gyrochronology ages between 100 Myr and 10 Gyr were derived for more than 17 000 stars using different gyrochronology relations, most of them with uncertainties dominated by period variations. We find a bimodal age distribution for Teff between 3200-4700 K. The derived ages reveal an empirical activity-age relation using photometric variability as stellar activity proxy. Additionally, we found 1079 stars with extremely stable (mostly short) periods. Half of these periods may be associated with rotation stabilized by non-eclipsing companions, the other half might be due to pulsations. Conclusions: The derived gyrochronology ages are well constrained since more than ~93.0% of the stars seem to be younger than the Sun where calibration is

Surface dimpling on rotating work piece using rotation cutting tool

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhapkar, Rohit Arun; Larsen, Eric Richard

A combined method of machining and applying a surface texture to a work piece and a tool assembly that is capable of machining and applying a surface texture to a work piece are disclosed. The disclosed method includes machining portions of an outer or inner surface of a work piece. The method also includes rotating the work piece in front of a rotating cutting tool and engaging the outer surface of the work piece with the rotating cutting tool to cut dimples in the outer surface of the work piece. The disclosed tool assembly includes a rotating cutting tool coupledmore » to an end of a rotational machining device, such as a lathe. The same tool assembly can be used to both machine the work piece and apply a surface texture to the work piece without unloading the work piece from the tool assembly.« less

Exchange rate regimes, saving glut and the Feldstein Horioka puzzle: The East Asian experience

NASA Astrophysics Data System (ADS)

Kaya-Bahçe, Seçil; Özmen, Erdal

2008-04-01

This paper investigates whether the recent experience of the emerging East Asian countries with current account surpluses is consistent with the “saving glut” hypothesis and the Feldstein and Horioka puzzle. The evidence suggests that the saving retention coefficients declined substantially in most of the countries after an endogenous break date coinciding with a major exchange rate regime change with the 1997-1998 crisis. Exchange rate flexibility appears to be enhancing financial integration. The results are consistent with an “investment slump” explanation rather than the “saving glut” postulation.

Controllable rotating behavior of individual dielectric microrod in a rotating electric field.

PubMed

Liu, Weiyu; Ren, Yukun; Tao, Ye; Li, Yanbo; Chen, Xiaoming

2017-06-01

We report herein controllable rotating behavior of an individual dielectric microrod driven by a background rotating electric field. By disposing or removing structured floating microelectrode, the rigid rod suspended in electrolyte solution accordingly exhibits cofield or antifield rotating motion. In the absence of the ideally polarizable metal surface, the dielectric rod rotates opposite to propagation of electric field, with the measured rotating rate much larger than predicted by Maxwell-Wager interfacial polarization theory incorporating surface conduction of fixed bond charge. Surprisingly, with floating electrode embedded, a novel kind of cofield rotation mode occurs in the presence of induced double-layer polarization, due to the action of hydrodynamic torque from rotating induced-charge electroosmosis. This method of achieving switchable spin modes of dielectric particles would direct implications in constructing flexible electrokinetic framework for analyzing 3D profile of on-chip biomicrofluidic samples. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rotation periods and photometric variability of rapidly rotating ultracool dwarfs

NASA Astrophysics Data System (ADS)

Miles-Páez, P. A.; Pallé, E.; Zapatero Osorio, M. R.

2017-12-01

We used the optical and near-infrared imagers located on the Liverpool, the IAC80, and the William Herschel telescopes to monitor 18 M7-L9.5 dwarfs with the objective of measuring their rotation periods. We achieved accuracies typically in the range ±1.5-28 mmag by means of differential photometry, which allowed us to detect photometric variability at the 2σ level in the 50 per cent of the sample. We also detected periodic modulation with periods in the interval 1.5-4.4 h in 9 out of 18 dwarfs that we attribute to rotation. Our variability detections were combined with data from the literature; we found that 65 ± 18 per cent of M7-L3.5 dwarfs with v sin i ≥ 30 km s-1 exhibit photometric variability with typical amplitudes ≤20 mmag in the I band. For those targets and field ultracool dwarfs with measurements of v sin i and rotation period we derived the expected inclination angle of their rotation axis, and found that those with v sin i ≥ 30 km s-1 are more likely to have inclinations ≳40 deg. In addition, we used these rotation periods and others from the literature to study the likely relationship between rotation and linear polarization in dusty ultracool dwarfs. We found a correlation between short rotation periods and large values of linear polarization at optical and near-infrared wavelengths.

The concepts of asymmetric and symmetric power can help resolve the puzzle of altruistic and cooperative behaviour.

PubMed

Phillips, Tim

2018-02-01

Evolutionary theory predicts competition in nature yet altruistic and cooperative behaviour appears to reduce the ability to compete in order to help others compete better. This evolutionary puzzle is usually explained by kin selection where close relatives perform altruistic and cooperative acts to help each other and by reciprocity theory (i.e. direct, indirect and generalized reciprocity) among non-kin. Here, it is proposed that the concepts of asymmetry and symmetry in power and dominance are critical if we are ever to resolve the puzzle of altruism and cooperation towards non-kin. Asymmetry in power and dominance is likely to emerge under competition in nature as individuals strive to gain greater access to the scarce resources needed to survive and reproduce successfully. Yet asymmetric power presents serious problems for reciprocity theory in that a dominant individual faces a temptation to cheat in interactions with subordinates that is likely to far outweigh any individual selective benefits gained through reciprocal mechanisms. Furthermore, action taken by subordinates to deter non-reciprocation by dominants is likely to prove prohibitively costly to their fitness, making successful enforcement of reciprocal mechanisms unlikely. It is also argued here that many apparently puzzling forms of cooperation observed in nature (e.g. cooperative breeding in which unrelated subordinates help dominants to breed) might be best explained by asymmetry in power and dominance. Once it is recognized that individuals in these cooperative interactions are subject to the constraints and opportunities imposed on them by asymmetric power then they can be seen as pursuing a 'least bad' strategy to promote individual fitness - one that is nevertheless consistent with evolutionary theory. The concept of symmetric power also provides important insights. It can inhibit reciprocal mechanisms in the sense that symmetric power makes it easier for a cheat to appropriate common

Rotation Frequencies of Small Jovian Trojan Asteroids: An Excess of Slow Rotators

NASA Astrophysics Data System (ADS)

French, Linda M.; Stephens, Robert D.; James, David J.; Coley, Daniel; Connour, Kyle

2015-11-01

Several lines of evidence support a common origin for, and possible hereditary link between, cometary nuclei and jovian Trojan asteroids. Due to their distance and low albedos, few comet-sized Trojans have been studied. We discuss the rotation properties of Jovian Trojan asteroids less than 30 km in diameter. Approximately half the 131 objects discussed here were studied using densely sampled lightcurves (French et al. 2015a, b); Stephens et al. 2015), and the other half were sparse lightcurves obtained by the Palomar Transient Factory (PTF; Waszcazk et al. 2015).A significant fraction (~40%) of the objects in the ground-based sample rotate slowly (P > 24h), with measured periods as long as 375 h (Warner and Stephens 2011). The PTF data show a similar excess of slow rotators. Only 5 objects in the combined data set have rotation periods of less than six hours. Three of these fast rotators were contained in the data set of French et al. these three had a geometric mean rotation period of 5.29 hours. A prolate spheroid held together by gravity rotating with this period would have a critical density of 0.43 gm/cm3, a density similar to that of comets (Lamy et al. 2004).Harris et al. (2012) and Warner et al. (2011) have explored the possible effects on asteroid rotational statistics with the results from wide-field surveys. We will examine Trojan rotation statistics with and without the results from the PTF.

Weird Stellar Pair Puzzles Scientists

NASA Astrophysics Data System (ADS)

2008-05-01

Astronomers have discovered a speedy spinning pulsar in an elongated orbit around an apparent Sun-like star, a combination never seen before, and one that has them puzzled about how the strange system developed. Orbital Comparison Comparing Orbits of Pulsar and Its Companion to our Solar System. CREDIT: Bill Saxton, NRAO/AUI/NSF Click on image for full caption information and available graphics. "Our ideas about how the fastest-spinning pulsars are produced do not predict either the kind of orbit or the type of companion star this one has," said David Champion of the Australia Telescope National Facility. "We have to come up with some new scenarios to explain this weird pair," he added. Astronomers first detected the pulsar, called J1903+0327, as part of a long-term survey using the National Science Foundation's Arecibo radio telescope in Puerto Rico. They made the discovery in 2006 doing data analysis at McGill University, where Champion worked at the time. They followed up the discovery with detailed studies using the Arecibo telescope, the NSF's Robert C. Byrd Green Bank Telescope (GBT) in West Virginia, the Westerbork radio telescope in the Netherlands, and the Gemini North optical telescope in Hawaii. The pulsar, a city-sized superdense stellar corpse left over after a massive star exploded as a supernova, is spinning on its axis 465 times every second. Nearly 21,000 light-years from Earth, it is in a highly-elongated orbit that takes it around its companion star once every 95 days. An infrared image made with the Gemini North telescope in Hawaii shows a Sun-like star at the pulsar's position. If this is an orbital companion to the pulsar, it is unlike any companions of other rapidly rotating pulsars. The pulsar, a neutron star, also is unusually massive for its type. "This combination of properties is unprecedented. Not only does it require us to figure out how this system was produced, but the large mass may help us understand how matter behaves at extremely

Tracking the Footprints Puzzle: The Problematic Persistence of Science-as-Process in Teaching the Nature and Culture of Science

ERIC Educational Resources Information Center

Ault, Charles R., Jr.; Dodick, Jeff

2010-01-01

For many decades, science educators have asked, "In what ways should learning the content of traditional subjects serve as the means to more general ends, such as understanding the nature of science or the processes of scientific inquiry?" Acceptance of these ends reduces the role of disciplinary context; the "Footprints Puzzle" and Oregon's…

Tornillos: Pieces of a Puzzle

NASA Astrophysics Data System (ADS)

Hellweg, M.; Seidl, D.

2001-12-01

In the past decade several of the ash eruptions at Galeras volcano (Colombia) have been preceded by tornillos. These unusual seismic events of unknown origin have screw-like profiles on seismograms and can last up to several minutes. Since 1997, a joint project between the Bundesanstalt für Geowissenschaften und Rohstoffe (BGR) and the Instituto de Investigación e Información Geocientífica, Minero-Ambiental y Nuclear (INGEOMINAS) has supplemented the shortperiod network of the Observatorio Vulcanológico de Pasto with four broadband, three-component seismometer stations, continuous fumarole gas chemistry measurments, electromagnetic sensors, an infrasound sensor and weather observations in the hopes to learn more about the physical or chemical process which generates tornillos and their significance in the sequence leading to ash explosions. The events of a suite of tornillos which occurred at Galeras Volcano between 08 December 1999 and 11 February 2000 were recorded well at the crater rim broadband stations, ANG and ACH. They appear to be more complex than many of the tornillos recorded previously. They are multichromatic, having narrow spectral peaks at up to 9 frequencies. Some peaks last throughout the entire tornillo, others only contribute to the turn-on transient. We compare polarization, frequency, amplitudes and decay measured from this suite of tornillos in each frequency band at the stations ANG and ACH. They indicate a single source location for all these tornillos. While other parameters correlate well at both stations, the amplitude of the 1.9 Hz peak is nearly twice as large at ACH than at ANG. This may indicate a distinct radiation pattern at this frequency. While none of these observations gives us a clear picture of the source process of tornillos, they provide additional puzzle pieces we can add those collected from other measurements.

Internal rotation in halogenated toluenes: Rotational spectrum of 2,3-difluorotoluene

NASA Astrophysics Data System (ADS)

Nair, K. P. Rajappan; Herbers, Sven; Grabow, Jens-Uwe; Lesarri, Alberto

2018-07-01

The microwave rotational spectrum of 2,3-difluorotoluene has been studied by pulsed supersonic jet using Fourier transform microwave spectroscopy. The tunneling splitting due to the methyl internal rotation in the ground torsional state could be unambiguously identified and the three-fold (V3) potential barrier hindering the internal rotation of the methyl top was determined as 2518.70(15) J/mol. The ground-state rotational parameters for the parent and seven 13C isotopic species in natural abundance were determined with high accuracy, including all quartic centrifugal distortion constants. The molecular structure was derived using the substitution (rs) method. From the rotational constants of the different isotopic species the rs structure as well as the r0 structure was determined. Supporting ab initio (MP2) and DFT (B3LYP) calculations provided comparative values for the potential barrier and molecular parameters.

Limited rotation of the mobile-bearing in a rotating platform total knee prosthesis.

PubMed

Garling, E H; Kaptein, B L; Nelissen, R G H H; Valstar, E R

2007-01-01

The hypothesis of this study was that the polyethylene bearing in a rotating platform total knee prosthesis shows axial rotation during a step-up motion, thereby facilitating the theoretical advantages of mobile-bearing knee prostheses. We examined 10 patients with rheumatoid arthritis who had a rotating platform total knee arthroplasty (NexGen LPS mobile, Zimmer Inc. Warsaw, USA). Fluoroscopic data was collected during a step-up motion six months postoperatively. A 3D-2D model fitting technique was used to reconstruct the in vivo 3D kinematics. The femoral component showed more axial rotation than the polyethylene mobile-bearing insert compared to the tibia during extension. In eight knees, the femoral component rotated internally with respect to the tibia during extension. In the other two knees the femoral component rotated externally with respect to the tibia. In all 10 patients, the femur showed more axial rotation than the mobile-bearing insert indicating the femoral component was sliding on the polyethylene of the rotating platform during the step-up motion. Possible explanations are a too limited conformity between femoral component and insert, the anterior located pivot location of the investigated rotating platform design, polyethylene on metal impingement and fibrous tissue formation between the mobile-bearing insert and the tibial plateau.

Effect of Rotation on Scaffold Motion and Cell Growth in Rotating Bioreactors.

PubMed

Varley, Mark C; Markaki, Athina E; Brooks, Roger A

2017-06-01

Efficient use of different bioreactor designs to improve cell growth in three-dimensional scaffolds requires an understanding of their mechanism of action. To address this for rotating wall vessel bioreactors, fluid and scaffold motion were investigated experimentally at different rotation speeds and vessel fill volumes. Low cost bioreactors with single and dual axis rotation were developed to investigate the effect of these systems on human osteoblast proliferation in free floating and constrained collagen-glycosaminoglycan porous scaffolds. A range of scaffold motions (free fall, periodic oscillation, and orbital motion) were observed at the rotation speeds and vessel fluid/air ratios used, with 85% fluid fill and an outer vessel wall velocity of ∼14 mm s -1 producing a scaffold in a free fall state. The cell proliferation results showed that after 14 and 21 days of culture, this combination of fluid fill and speed of rotation produced significantly greater cell numbers in the scaffolds than when lower or higher rotation speeds (p < 0.002) or when the chamber was 60% or 100% full (p < 0.01). The fluid flow and scaffold motion experiments show that biaxial rotation would not improve the mass transfer of medium into the scaffold as the second axis of rotation can only transition the scaffold toward oscillatory or orbital motion and, hence, reduce mass transport to the scaffold. The cell culture results confirmed that there was no benefit to the second axis of rotation with no significant difference in cell proliferation either when the scaffolds were free floating or constrained (p > 0.05).

Effect of Rotation on Scaffold Motion and Cell Growth in Rotating Bioreactors

PubMed Central

Varley, Mark C.; Markaki, Athina E.

2017-01-01

Efficient use of different bioreactor designs to improve cell growth in three-dimensional scaffolds requires an understanding of their mechanism of action. To address this for rotating wall vessel bioreactors, fluid and scaffold motion were investigated experimentally at different rotation speeds and vessel fill volumes. Low cost bioreactors with single and dual axis rotation were developed to investigate the effect of these systems on human osteoblast proliferation in free floating and constrained collagen-glycosaminoglycan porous scaffolds. A range of scaffold motions (free fall, periodic oscillation, and orbital motion) were observed at the rotation speeds and vessel fluid/air ratios used, with 85% fluid fill and an outer vessel wall velocity of ∼14 mm s−1 producing a scaffold in a free fall state. The cell proliferation results showed that after 14 and 21 days of culture, this combination of fluid fill and speed of rotation produced significantly greater cell numbers in the scaffolds than when lower or higher rotation speeds (p < 0.002) or when the chamber was 60% or 100% full (p < 0.01). The fluid flow and scaffold motion experiments show that biaxial rotation would not improve the mass transfer of medium into the scaffold as the second axis of rotation can only transition the scaffold toward oscillatory or orbital motion and, hence, reduce mass transport to the scaffold. The cell culture results confirmed that there was no benefit to the second axis of rotation with no significant difference in cell proliferation either when the scaffolds were free floating or constrained (p > 0.05). PMID:28125920

Earth Rotation

NASA Technical Reports Server (NTRS)

Dickey, Jean O.

1995-01-01

The study of the Earth's rotation in space (encompassing Universal Time (UT1), length of day, polar motion, and the phenomena of precession and nutation) addresses the complex nature of Earth orientation changes, the mechanisms of excitation of these changes and their geophysical implications in a broad variety of areas. In the absence of internal sources of energy or interactions with astronomical objects, the Earth would move as a rigid body with its various parts (the crust, mantle, inner and outer cores, atmosphere and oceans) rotating together at a constant fixed rate. In reality, the world is considerably more complicated, as is schematically illustrated. The rotation rate of the Earth's crust is not constant, but exhibits complicated fluctuations in speed amounting to several parts in 10(exp 8) [corresponding to a variation of several milliseconds (ms) in the Length Of the Day (LOD) and about one part in 10(exp 6) in the orientation of the rotation axis relative to the solid Earth's axis of figure (polar motion). These changes occur over a broad spectrum of time scales, ranging from hours to centuries and longer, reflecting the fact that they are produced by a wide variety of geophysical and astronomical processes. Geodetic observations of Earth rotation changes thus provide insights into the geophysical processes illustrated, which are often difficult to obtain by other means. In addition, these measurements are required for engineering purposes. Theoretical studies of Earth rotation variations are based on the application of Euler's dynamical equations to the problem of finding the response of slightly deformable solid Earth to variety of surface and internal stresses.

Rotating reactor studies

NASA Technical Reports Server (NTRS)

Roberts, Glyn O.

1991-01-01

Undesired gravitational effects such as convection or sedimentation in a fluid can sometimes be avoided or decreased by the use of a closed chamber uniformly rotated about a horizontal axis. In a previous study, the spiral orbits of a heavy or buoyant particle in a uniformly rotating fluid were determined. The particles move in circles, and spiral in or out under the combined effects of the centrifugal force and centrifugal buoyancy. A optimization problem for the rotation rate of a cylindrical reactor rotated about its axis and containing distributed particles was formulated and solved. Related studies in several areas are addressed. A computer program based on the analysis was upgraded by correcting some minor errors, adding a sophisticated screen-and-printer graphics capability and other output options, and by improving the automation. The design, performance, and analysis of a series of experiments with monodisperse polystyrene latex microspheres in water were supported to test the theory and its limitations. The theory was amply confirmed at high rotation rates. However, at low rotation rates (1 rpm or less) the assumption of uniform solid-body rotation of the fluid became invalid, and there were increasingly strong secondary motions driven by variations in the mean fluid density due to variations in the particle concentration. In these tests the increase in the mean fluid density due to the particles was of order 0.015 percent. To a first approximation, these flows are driven by the buoyancy in a thin crescent-shaped depleted layer on the descending side of the rotating reactor. This buoyancy distribution is balanced by viscosity near the walls, and by the Coriolis force in the interior. A full analysis is beyond the scope of this study. Secondary flows are likely to be stronger for buoyant particles, which spiral in towards the neutral point near the rotation axis under the influence of their centrifugal buoyancy. This is because the depleted layer is

Rotating Wavepackets

ERIC Educational Resources Information Center

Lekner, John

2008-01-01

Any free-particle wavepacket solution of Schrodinger's equation can be converted by differentiations to wavepackets rotating about the original direction of motion. The angular momentum component along the motion associated with this rotation is an integral multiple of [h-bar]. It is an "intrinsic" angular momentum: independent of origin and…

Rotational response of superconductors: Magnetorotational isomorphism and rotation-induced vortex lattice

NASA Astrophysics Data System (ADS)

Babaev, Egor; Svistunov, Boris

2014-03-01

The analysis of nonclassical rotational response of superfluids and superconductors was performed by Onsager [Onsager, Nuovo Cimento, Suppl. 6, 279 (1949), 10.1007/BF02780991] and London [Superfluids (Wiley, New York, 1950)] and crucially advanced by Feynman [Prog. Low Temp. Phys. 1, 17 (1955), 10.1016/S0079-6417(08)60077-3]. It was established that, in the thermodynamic limit, neutral superfluids rotate by forming—without any threshold—a vortex lattice. In contrast, the rotation of superconductors at angular frequency Ω—supported by uniform magnetic field BL∝Ω due to surface currents—is of the rigid-body type (London law). Here we show that, neglecting the centrifugal effects, the behavior of a rotating superconductor is identical to that of a superconductor placed in a uniform fictitious external magnetic field H ˜=-BL. In particular, the isomorphism immediately implies the existence of two critical rotational frequencies in type-2 superconductors.

The optimal power puzzle: scrutiny of the monotone likelihood ratio assumption in multiple testing.

PubMed

Cao, Hongyuan; Sun, Wenguang; Kosorok, Michael R

2013-01-01

In single hypothesis testing, power is a non-decreasing function of type I error rate; hence it is desirable to test at the nominal level exactly to achieve optimal power. The puzzle lies in the fact that for multiple testing, under the false discovery rate paradigm, such a monotonic relationship may not hold. In particular, exact false discovery rate control may lead to a less powerful testing procedure if a test statistic fails to fulfil the monotone likelihood ratio condition. In this article, we identify different scenarios wherein the condition fails and give caveats for conducting multiple testing in practical settings.

Time travel, Clock Puzzles and Their Experimental Tests

NASA Astrophysics Data System (ADS)

Ciufolini, Ignazio

2013-09-01

Is time travel possible? What is Einstein's theory of relativity mathematically predicting in that regard? Is time travel related to the so-called clock `paradoxes' of relativity and if so how? Is there any accurate experimental evidence of the phenomena regarding the different flow of time predicted by General Relativity and is there any possible application of the temporal phenomena predicted by relativity to our everyday life? Which temporal phenomena are predicted in the vicinities of a rotating body and of a mass-energy current, and do we have any experimental test of the occurrence of these phenomena near a rotating body? In this paper, we address and answer some of these questions.

DNA is structured as a linear "jigsaw puzzle" in the genomes of Arabidopsis, rice, and budding yeast.

PubMed

Liu, Yun-Hua; Zhang, Meiping; Wu, Chengcang; Huang, James J; Zhang, Hong-Bin

2014-01-01

Knowledge of how a genome is structured and organized from its constituent elements is crucial to understanding its biology and evolution. Here, we report the genome structuring and organization pattern as revealed by systems analysis of the sequences of three model species, Arabidopsis, rice and yeast, at the whole-genome and chromosome levels. We found that all fundamental function elements (FFE) constituting the genomes, including genes (GEN), DNA transposable elements (DTE), retrotransposable elements (RTE), simple sequence repeats (SSR), and (or) low complexity repeats (LCR), are structured in a nonrandom and correlative manner, thus leading to a hypothesis that the DNA of the species is structured as a linear "jigsaw puzzle". Furthermore, we showed that different FFE differ in their importance in the formation and evolution of the DNA jigsaw puzzle structure between species. DTE and RTE play more important roles than GEN, LCR, and SSR in Arabidopsis, whereas GEN and RTE play more important roles than LCR, SSR, and DTE in rice. The genes having multiple recognized functions play more important roles than those having single functions. These results provide useful knowledge necessary for better understanding genome biology and evolution of the species and for effective molecular breeding of rice.

William Wales and the 1769 transit of Venus: puzzle solving and the determination of the astronomical unit

NASA Astrophysics Data System (ADS)

Metz, Don

2009-05-01

According to Thomas Kuhn, a significant part of “normal science” is the fact gathering, empirical work which is intended to illustrate an existing paradigm. Some of this effort focuses on the determination of physical constants such as the astronomical unit (AU). For Kuhn, normal science is also what prepares students for membership in a particular scientific community and is embodied in some form in our science textbooks. However, neither Kuhn nor the textbook says much about the individuals who practice normal science, especially those who had been relegated to the “hack” duties of long and arduous measurement and calculation. In this paper, to provide a context for students of astronomy, I will outline the story of the determination of the AU and in particular the contribution of William Wales, an obscure British astronomer. Wales, toiling in the shadow of Halley (of Halley’s comet fame), Mason and Dixon (of Mason and Dixon line fame) and the infamous Captain Cook endured a brutal winter in northern Canada for a brief glimpse of the 1769 transit of Venus. In the end, Wales supplied one small piece of the puzzle in the determination of the AU and he exemplified the human spirit and persistence of a Kuhnian “puzzle solver”.

A possible solution to the B → π π puzzle using the principle of maximum conformality

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qiao, Cong -Feng; Zhu, Rui -Lin; Wu, Xing

2015-07-22

We measured the B d→π 0π 0B d→π 0π 0 branching fraction and found that it deviates significantly from conventional QCD predictions, a puzzle which has persisted for more than 10 years. This may be a hint of new physics beyond the Standard Model; however, as we shall show in this paper, the pQCD prediction is highly sensitive to the choice of the renormalization scales which enter the decay amplitude. In the present paper, we show that the renormalization scale uncertainties for B→ππB→ππ can be greatly reduced by applying the Principle of Maximum Conformality (PMC), and more precise predictions formore » CP-averaged branching ratios B(B→ππ)B(B→ππ) can be achieved. Combining the errors in quadrature, we obtain View the MathML sourceB(Bd→π 0π 0)|PMC=(0.98 -0.31 +0.44)×10 -6 by using the light-front holographic low-energy model for the running coupling. All of the CP-averaged B→ππB→ππ branching fractions predicted by the PMC are consistent with the Particle Data Group average values and the recent Belle data. Moreover, the PMC provides a possible solution for the B d→π 0π 0B d→π 0π 0 puzzle.« less

Jet Engine Bird Ingestion Simulations: Comparison of Rotating to Non-Rotating Fan Blades

NASA Technical Reports Server (NTRS)

Howard, Samuel A.; Hammer, Jeremiah; Carney, Kelly S.; Pereira, J. Michael

2013-01-01

Bird strike events in commercial airliners are a fairly common occurrence. According to data collected by the US Department of Agriculture, over 80,000 bird strikes were reported in the period 1990-2007 in the US alone [1]. As a result, bird ingestion is an important factor in aero engine design and FAA certification. When it comes to bird impacts on engine fan blades, the FAA requires full-scale bird ingestion tests on an engine running at full speed to pass certification requirements. These rotating tests are complex and very expensive. To reduce development costs associated with new materials for fan blades, it is desirable to develop more cost effective testing procedures than full-scale rotating engine tests for material evaluation. An impact test on a non-rotating single blade that captures most of the salient physics of the rotating test would go a long way towards enabling large numbers of evaluative material screening tests. NASA Glenn Research Center has been working to identify a static blade test procedure that would be effective at reproducing similar results as seen in rotating tests. The current effort compares analytical simulations of a bird strike on various nonrotating blades to a bird strike simulation on a rotating blade as a baseline case. Several different concepts for simulating the rotating loads on a non-rotating blade were analyzed with little success in duplicating the deformation results seen in the rotating case. The rotating blade behaves as if it were stiffer than the non-rotating blade resulting in less plastic deformation from a given bird impact. The key factor limiting the success of the non-rotating blade simulations is thought to be the effect of gyroscopics. Prior to this effort, it was anticipated the difficulty would be in matching the pre-stress in the blade due to centrifugal forces Additional work is needed to verify this assertion, and to determine if a static test procedure can simulate the gyroscopic effects in a

Jet Engine Bird Ingestion Simulations: Comparison of Rotating to Non-Rotating Fan Blades

NASA Technical Reports Server (NTRS)

Howard, Samuel A.; Hammer, Jeremiah T.; Carney, Kelly S.; Pereira, J. Michael

2013-01-01

Bird strike events in commercial airliners are a fairly common occurrence. According to data collected by the US Department of Agriculture, over 80,000 bird strikes were reported in the period 1990 to 2007 in the US alone (Ref. 1). As a result, bird ingestion is an important factor in aero engine design and FAA certification. When it comes to bird impacts on engine fan blades, the FAA requires full-scale bird ingestion tests on an engine running at full speed to pass certification requirements. These rotating tests are complex and very expensive. To reduce development costs associated with new materials for fan blades, it is desirable to develop more cost effective testing procedures than full-scale rotating engine tests for material evaluation. An impact test on a nonrotating single blade that captures most of the salient physics of the rotating test would go a long way towards enabling large numbers of evaluative material screening tests. NASA Glenn Research Center has been working to identify a static blade test procedure that would be effective at reproducing similar results as seen in rotating tests. The current effort compares analytical simulations of a bird strike on various non-rotating blades to a bird strike simulation on a rotating blade as a baseline case. Several different concepts for simulating the rotating loads on a non-rotating blade were analyzed with little success in duplicating the deformation results seen in the rotating case. The rotating blade behaves as if it were stiffer than the non-rotating blade resulting in less plastic deformation from a given bird impact. The key factor limiting the success of the non-rotating blade simulations is thought to be the effect of gyroscopics. Prior to this effort, it was anticipated the difficulty would be in matching the prestress in the blade due to centrifugal forces Additional work is needed to verify this assertion, and to determine if a static test procedure can simulate the gyroscopic effects in

Notes on rotating turbulence

NASA Technical Reports Server (NTRS)

Zeman, Otto

1994-01-01

This work investigates the turbulent constitutive relation when turbulence is subjected to solid body rotation. Laws regarding spectra and asymptotic decay of rotating homogeneous turbulence were confirmed through large-eddy simulation (LES) computations. Rotating turbulent flows exist in many industrial, geophysical, and astrophysical applications. From Lagrangian analysis a relation between turbulent stress and strain in rotating homogeneous turbulence was inferred. This relation was used to derive the spectral energy flux and, ultimately, the energy spectrum form. If the rotation wavenumber k(sub Omega) lies in the inertial subrange, then for wavenumbers less than k(sub Omega) the turbulence motions are affected by rotation and the energy spectrum slope is modified. Energy decay laws inferred in other reports and the present results suggest a modification of the epsilon model equation and eddy viscosity in k-epsilon models.

SEAL FOR ROTATING SHAFT

DOEpatents

Coffman, R.T.

1957-12-10

A seal is described for a rotatable shaft that must highly effective when the shaft is not rotating but may be less effective while the shaft is rotating. Weights distributed about a sealing disk secured to the shaft press the sealing disk against a tubular section into which the shiilt extends, and whem the shaft rotates, the centrifugal forces on the weights relieve the pressurc of the sealing disk against the tubular section. This action has the very desirible result of minimizing the wear of the rotating disk due to contact with the tubular section, while affording maximum sealing action when it is needed.

X-ray illumination of globular cluster puzzles. [globular cluster X ray sources as clues to Milky Way Galaxy age and evolution

NASA Technical Reports Server (NTRS)

Lightman, A. P.; Grindlay, J. E.

1982-01-01

Globular clusters are thought to be among the oldest objects in the Galaxy, and provide, in this connection, important clues for determining the age and process of formation of the Galaxy. The present investigation is concerned with puzzles relating to the X-ray emission of globular clusters, taking into account questions regarding the location of X-ray emitting clusters (XEGC) unusually near the galactic plane and/or galactic center. An adopted model is discussed for the nature, formation, and lifetime of X-ray sources in globular clusters. An analysis of the available data is conducted in connection with a search for correlations between binary formation time scales, central relaxation times, galactic locations, and X-ray emission. The positive correlation found between distance from galactic center and two-body binary formation time for globular clusters, explanations for this correlation, and the hypothesis that X-ray sources in globular clusters require binary star systems provide a possible explanation of the considered puzzles.

Pieces of the Puzzle: Factors in the Improvement of Urban School Districts on the National Assessment of Educational Progress. Abstract

ERIC Educational Resources Information Center

Casserly, Michael; Price-Baugh, Ricki; Corcoran, Amanda; Lewis, Sharon; Uzzell, Renata; Simon, Candace; Heppen, Jessica; Leinwand, Steve; Salinger, Terry; de Mello, Victor Bandeira; Dogan, Enis; Novotny, Laura

2011-01-01

This is an abridged, summary report of selected findings from "Pieces of the Puzzle: Factors in the Improvement of Urban School Districts on the National Assessment of Educational Progress"--a comprehensive study prepared by the Council of the Great City Schools in collaboration with the American Institutes for Research (AIR) and with…

Why plants make puzzle cells, and how their shape emerges.

PubMed

Sapala, Aleksandra; Runions, Adam; Routier-Kierzkowska, Anne-Lise; Das Gupta, Mainak; Hong, Lilan; Hofhuis, Hugo; Verger, Stéphane; Mosca, Gabriella; Li, Chun-Biu; Hay, Angela; Hamant, Olivier; Roeder, Adrienne Hk; Tsiantis, Miltos; Prusinkiewicz, Przemyslaw; Smith, Richard S

2018-02-27

The shape and function of plant cells are often highly interdependent. The puzzle-shaped cells that appear in the epidermis of many plants are a striking example of a complex cell shape, however their functional benefit has remained elusive. We propose that these intricate forms provide an effective strategy to reduce mechanical stress in the cell wall of the epidermis. When tissue-level growth is isotropic, we hypothesize that lobes emerge at the cellular level to prevent formation of large isodiametric cells that would bulge under the stress produced by turgor pressure. Data from various plant organs and species support the relationship between lobes and growth isotropy, which we test with mutants where growth direction is perturbed. Using simulation models we show that a mechanism actively regulating cellular stress plausibly reproduces the development of epidermal cell shape. Together, our results suggest that mechanical stress is a key driver of cell-shape morphogenesis. © 2018, Sapala et al.

Why plants make puzzle cells, and how their shape emerges

PubMed Central

Routier-Kierzkowska, Anne-Lise; Das Gupta, Mainak; Hong, Lilan; Hofhuis, Hugo; Verger, Stéphane; Mosca, Gabriella; Li, Chun-Biu; Hay, Angela; Hamant, Olivier; Roeder, Adrienne HK; Tsiantis, Miltos; Prusinkiewicz, Przemyslaw

2018-01-01

The shape and function of plant cells are often highly interdependent. The puzzle-shaped cells that appear in the epidermis of many plants are a striking example of a complex cell shape, however their functional benefit has remained elusive. We propose that these intricate forms provide an effective strategy to reduce mechanical stress in the cell wall of the epidermis. When tissue-level growth is isotropic, we hypothesize that lobes emerge at the cellular level to prevent formation of large isodiametric cells that would bulge under the stress produced by turgor pressure. Data from various plant organs and species support the relationship between lobes and growth isotropy, which we test with mutants where growth direction is perturbed. Using simulation models we show that a mechanism actively regulating cellular stress plausibly reproduces the development of epidermal cell shape. Together, our results suggest that mechanical stress is a key driver of cell-shape morphogenesis. PMID:29482719

Lattice QCD in rotating frames.

PubMed

Yamamoto, Arata; Hirono, Yuji

2013-08-23

We formulate lattice QCD in rotating frames to study the physics of QCD matter under rotation. We construct the lattice QCD action with the rotational metric and apply it to the Monte Carlo simulation. As the first application, we calculate the angular momenta of gluons and quarks in the rotating QCD vacuum. This new framework is useful to analyze various rotation-related phenomena in QCD.

Rotational properties of planetary satellites

NASA Technical Reports Server (NTRS)

Peale, S. J.

1991-01-01

Properties of satellite rotation that are observable in principle, include the rotation period, the orientation of the spin axis relative to the orbit plane, precession of the spin axis due to gravitational torques, nonprincipal axis rotation or wobble, and deviations from uniform principle axis rotation or libration. Considerable order is observed in current satellite rotation states, and it is of interest to ascertain how this order came about and why some satellites do not conform to the dominant norm. There is a strong coupling between the spin and orbital motions that is primarily responsible for maintaining the ordered rotation states in most cases, but this coupling is equally responsible for destroying any chance of orderly rotation for Saturn's satellite Hyperion. Understanding the processes which constrain current rotation states as well as those of an evolutionary nature which could have brought the individual satellites to their observed rotation and orbit states allows us to sometimes infer interior properties of some satellite or even of its primary planet, although, attempts to deduce primordial rotation states are usually frustrated. The observed rotational properties of the planetary satellites are summarized, and the understanding of the processes maintaining and those leading to the observed states are outlined. Some of the inferences that can be drawn about intrinsic properties of the bodies themselves are indicated.

Stress field rotation or block rotation: An example from the Lake Mead fault system

NASA Technical Reports Server (NTRS)

Ron, Hagai; Nur, Amos; Aydin, Atilla

1990-01-01

The Coulomb criterion, as applied by Anderson (1951), has been widely used as the basis for inferring paleostresses from in situ fault slip data, assuming that faults are optimally oriented relative to the tectonic stress direction. Consequently if stress direction is fixed during deformation so must be the faults. Freund (1974) has shown that faults, when arranged in sets, must generally rotate as they slip. Nur et al., (1986) showed how sufficiently large rotations require the development of new sets of faults which are more favorably oriented to the principal direction of stress. This leads to the appearance of multiple fault sets in which older faults are offset by younger ones, both having the same sense of slip. Consequently correct paleostress analysis must include the possible effect of fault and material rotation, in addition to stress field rotation. The combined effects of stress field rotation and material rotation were investigated in the Lake Meade Fault System (LMFS) especially in the Hoover Dam area. Fault inversion results imply an apparent 60 degrees clockwise (CW) rotation of the stress field since mid-Miocene time. In contrast structural data from the rest of the Great Basin suggest only a 30 degrees CW stress field rotation. By incorporating paleomagnetic and seismic evidence, the 30 degrees discrepancy can be neatly resolved. Based on paleomagnetic declination anomalies, it is inferred that slip on NW trending right lateral faults caused a local 30 degrees counter-clockwise (CCW) rotation of blocks and faults in the Lake Mead area. Consequently the inferred 60 degrees CW rotation of the stress field in the LMFS consists of an actual 30 degrees CW rotation of the stress field (as for the entire Great Basin) plus a local 30 degrees CCW material rotation of the LMFS fault blocks.

Stress field rotation or block rotation: An example from the Lake Mead fault system

NASA Astrophysics Data System (ADS)

Ron, Hagai; Nur, Amos; Aydin, Atilla

1990-02-01

The Coulomb criterion, as applied by Anderson (1951), has been widely used as the basis for inferring paleostresses from in situ fault slip data, assuming that faults are optimally oriented relative to the tectonic stress direction. Consequently if stress direction is fixed during deformation so must be the faults. Freund (1974) has shown that faults, when arranged in sets, must generally rotate as they slip. Nur et al., (1986) showed how sufficiently large rotations require the development of new sets of faults which are more favorably oriented to the principal direction of stress. This leads to the appearance of multiple fault sets in which older faults are offset by younger ones, both having the same sense of slip. Consequently correct paleostress analysis must include the possible effect of fault and material rotation, in addition to stress field rotation. The combined effects of stress field rotation and material rotation were investigated in the Lake Meade Fault System (LMFS) especially in the Hoover Dam area. Fault inversion results imply an apparent 60 degrees clockwise (CW) rotation of the stress field since mid-Miocene time. In contrast structural data from the rest of the Great Basin suggest only a 30 degrees CW stress field rotation. By incorporating paleomagnetic and seismic evidence, the 30 degrees discrepancy can be neatly resolved. Based on paleomagnetic declination anomalies, it is inferred that slip on NW trending right lateral faults caused a local 30 degrees counter-clockwise (CCW) rotation of blocks and faults in the Lake Mead area. Consequently the inferred 60 degrees CW rotation of the stress field in the LMFS consists of an actual 30 degrees CW rotation of the stress field (as for the entire Great Basin) plus a local 30 degrees CCW material rotation of the LMFS fault blocks.

Units of rotational information

NASA Astrophysics Data System (ADS)

Yang, Yuxiang; Chiribella, Giulio; Hu, Qinheping

2017-12-01

Entanglement in angular momentum degrees of freedom is a precious resource for quantum metrology and control. Here we study the conversions of this resource, focusing on Bell pairs of spin-J particles, where one particle is used to probe unknown rotations and the other particle is used as reference. When a large number of pairs are given, we show that every rotated spin-J Bell state can be reversibly converted into an equivalent number of rotated spin one-half Bell states, at a rate determined by the quantum Fisher information. This result provides the foundation for the definition of an elementary unit of information about rotations in space, which we call the Cartesian refbit. In the finite copy scenario, we design machines that approximately break down Bell states of higher spins into Cartesian refbits, as well as machines that approximately implement the inverse process. In addition, we establish a quantitative link between the conversion of Bell states and the simulation of unitary gates, showing that the fidelity of probabilistic state conversion provides upper and lower bounds on the fidelity of deterministic gate simulation. The result holds not only for rotation gates, but also to all sets of gates that form finite-dimensional representations of compact groups. For rotation gates, we show how rotations on a system of given spin can simulate rotations on a system of different spin.

Patient-specific puzzle implant preformed with 3D-printed rapid prototype model for combined orbital floor and medial wall fracture.

PubMed

Kim, Young Chul; Min, Kyung Hyun; Choi, Jong Woo; Koh, Kyung S; Oh, Tae Suk; Jeong, Woo Shik

2018-04-01

The management of combined orbital floor and medial wall fractures involving the inferomedial strut is challenging due to absence of stable cornerstone. In this article, we proposed surgical strategies using customized 3D puzzle implant preformed with Rapid Prototype (RP) skull model. Retrospective review was done in 28 patients diagnosed with combined orbital floor and medial wall fracture. Using preoperative CT scans, original and mirror-imaged RP skull models for each patient were prepared and sterilized. In all patients, porous polyethylene-coated titanium mesh was premolded onto RP skull model in two ways; Customized 3D jigsaw puzzle technique was used in 15 patients with comminuted inferomedial strut, whereas individual 3D implant technique was used in each fracture for 13 patients with intact inferomedial strut. Outcomes including enophthalmos, visual acuity, and presence of diplopia were assessed and orbital volume was measured using OsiriX software preoperatively and postoperatively. Satisfactory results were achieved in both groups in terms of clinical improvements. Of 10 patients with preoperative diplopia, 9 improved in 6 months, except one with persistent symptom who underwent extraocular muscle rupture. 18 patients who had moderate to severe enophthalmos preoperatively improved, and one remained with mild degree. Orbital volume ratio, defined as volumetric ratio between affected and control orbit, decreased from 127.6% to 99.79% (p < 0.05) in comminuted group, and that in intact group decreased from 117.03% to 101.3% (p < 0.05). Our surgical strategies using the jigsaw puzzle and individual reconstruction technique provide accurate restoration of combined orbital floor and medial wall fractures. Copyright © 2017 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Visual information processing in the lion-tailed macaque (Macaca silenus): mental rotation or rotational invariance?

PubMed

Burmann, Britta; Dehnhardt, Guido; Mauck, Björn

2005-01-01

Mental rotation is a widely accepted concept indicating an image-like mental representation of visual information and an analogue mode of information processing in certain visuospatial tasks. In the task of discriminating between image and mirror-image of rotated figures, human reaction times increase with the angular disparity between the figures. In animals, tests of this kind yield inconsistent results. Pigeons were found to use a time-independent rotational invariance, possibly indicating a non-analogue information processing system that evolved in response to the horizontal plane of reference birds perceive during flight. Despite similar ecological demands concerning the visual reference plane, a sea lion was found to use mental rotation in similar tasks, but its processing speed while rotating three-dimensional stimuli seemed to depend on the axis of rotation in a different way than found for humans in similar tasks. If ecological demands influence the way information processing systems evolve, hominids might have secondarily lost the ability of rotational invariance while retreating from arboreal living and evolving an upright gait in which the vertical reference plane is more important. We therefore conducted mental rotation experiments with an arboreal living primate species, the lion-tailed macaque. Performing a two-alternative matching-to-sample procedure, the animal had to decide between rotated figures representing image and mirror-image of a previously shown upright sample. Although non-rotated stimuli were recognized faster than rotated ones, the animal's mean reaction times did not clearly increase with the angle of rotation. These results are inconsistent with the mental rotation concept but also cannot be explained assuming a mere rotational invariance. Our study thus seems to support the idea of information processing systems evolving gradually in response to specific ecological demands.

Judging sound rotation when listeners and sounds rotate: Sound source localization is a multisystem process.

PubMed

Yost, William A; Zhong, Xuan; Najam, Anbar

2015-11-01

In four experiments listeners were rotated or were stationary. Sounds came from a stationary loudspeaker or rotated from loudspeaker to loudspeaker around an azimuth array. When either sounds or listeners rotate the auditory cues used for sound source localization change, but in the everyday world listeners perceive sound rotation only when sounds rotate not when listeners rotate. In the everyday world sound source locations are referenced to positions in the environment (a world-centric reference system). The auditory cues for sound source location indicate locations relative to the head (a head-centric reference system), not locations relative to the world. This paper deals with a general hypothesis that the world-centric location of sound sources requires the auditory system to have information about auditory cues used for sound source location and cues about head position. The use of visual and vestibular information in determining rotating head position in sound rotation perception was investigated. The experiments show that sound rotation perception when sources and listeners rotate was based on acoustic, visual, and, perhaps, vestibular information. The findings are consistent with the general hypotheses and suggest that sound source localization is not based just on acoustics. It is a multisystem process.

The deuteron-radius puzzle is alive: A new analysis of nuclear structure uncertainties

NASA Astrophysics Data System (ADS)

Hernandez, O. J.; Ekström, A.; Nevo Dinur, N.; Ji, C.; Bacca, S.; Barnea, N.

2018-03-01

To shed light on the deuteron radius puzzle we analyze the theoretical uncertainties of the nuclear structure corrections to the Lamb shift in muonic deuterium. We find that the discrepancy between the calculated two-photon exchange correction and the corresponding experimentally inferred value by Pohl et al. [1] remain. The present result is consistent with our previous estimate, although the discrepancy is reduced from 2.6 σ to about 2 σ. The error analysis includes statistic as well as systematic uncertainties stemming from the use of nucleon-nucleon interactions derived from chiral effective field theory at various orders. We therefore conclude that nuclear theory uncertainty is more likely not the source of the discrepancy.

Sex differences in mental rotation tasks: Not just in the mental rotation process!

PubMed

Boone, Alexander P; Hegarty, Mary

2017-07-01

The paper-and-pencil Mental Rotation Test (Vandenberg & Kuse, 1978) consistently produces large sex differences favoring men (Voyer, Voyer, & Bryden, 1995). In this task, participants select 2 of 4 answer choices that are rotations of a probe stimulus. Incorrect choices (i.e., foils) are either mirror reflections of the probe or structurally different. In contrast, in the mental rotation experimental task (Shepard & Metzler, 1971) participants judge whether 2 stimuli are the same but rotated or different by mirror reflection. The goal of the present research was to examine sources of sex differences in mental rotation, including the ability to capitalize on the availability of structure foils. In 2 experiments, both men and women had greater accuracy and faster reaction times (RTs) for structurally different compared with mirror foils in different versions of the Vandenberg and Kuse Mental Rotation Test (Experiment 1) and the Shepard and Metzler experimental task (Experiment 2). A significant male advantage in accuracy but not response time was found for both trial types. The male advantage was evident when all foils were structure foils so that mental rotation was not necessary (Experiment 3); however, when all foils were structure foils and participants were instructed to look for structure foils a significant sex difference was no longer evident (Experiment 4). Results suggest that the mental rotation process is not the only source of the sex difference in mental rotation tasks. Alternative strategy use is another source of sex differences in these tasks. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Impact of a counter-rotating planetary rotation system on thin-film thickness and uniformity

DOE PAGES

Oliver, J. B.

2017-06-12

Planetary rotation systems incorporating forward- and counter-rotating planets are used as a means of increasing coating-system capacity for large oblong substrates. Comparisons of planetary motion for the two types of rotating systems are presented based on point tracking for multiple revolutions, as well as comparisons of quantitative thickness and uniformity. Counter-rotation system geometry is shown to result in differences in thin-film thickness relative to standard planetary rotation for precision optical coatings. As a result, this systematic error in thin-film thickness will reduce deposition yields for sensitive coating designs.

Impact of a counter-rotating planetary rotation system on thin-film thickness and uniformity.

PubMed

Oliver, J B

2017-06-20

Planetary rotation systems incorporating forward- and counter-rotating planets are used as a means of increasing coating-system capacity for large oblong substrates. Comparisons of planetary motion for the two types of rotating systems are presented based on point tracking for multiple revolutions as well as comparisons of quantitative thickness and uniformity. Counter-rotation system geometry is shown to result in differences in thin-film thickness relative to standard planetary rotation for precision optical coatings. This systematic error in thin-film thickness will reduce deposition yields for sensitive coating designs.

Impact of a counter-rotating planetary rotation system on thin-film thickness and uniformity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oliver, J. B.

Planetary rotation systems incorporating forward- and counter-rotating planets are used as a means of increasing coating-system capacity for large oblong substrates. Comparisons of planetary motion for the two types of rotating systems are presented based on point tracking for multiple revolutions, as well as comparisons of quantitative thickness and uniformity. Counter-rotation system geometry is shown to result in differences in thin-film thickness relative to standard planetary rotation for precision optical coatings. As a result, this systematic error in thin-film thickness will reduce deposition yields for sensitive coating designs.

Rotational Spectrum of 1,1-Difluoroethane: Internal Rotation Analysis and Structure

NASA Astrophysics Data System (ADS)

Villamanan, R. M.; Chen, W. D.; Wlodarczak, G.; Demaison, J.; Lesarri, A. G.; Lopez, J. C.; Alonso, J. L.

1995-05-01

The rotational spectrum of CH3CHF2 in its ground state was measured up to 653 GHz. Accurate rotational and centrifugal distortion constants were determined. The internal rotation splittings were analyzed using the internal axis method. An ab initio structure has been calculated and a near-equilibrium structure has been estimated using offsets derived empirically. This structure was compared to an experimental r0 structure. The four lowest excited states (including the methyl torsion) have also been assigned.

Rotationally Vibrating Electric-Field Mill

NASA Technical Reports Server (NTRS)

Kirkham, Harold

2008-01-01

A proposed instrument for measuring a static electric field would be based partly on a conventional rotating-split-cylinder or rotating-split-sphere electric-field mill. However, the design of the proposed instrument would overcome the difficulty, encountered in conventional rotational field mills, of transferring measurement signals and power via either electrical or fiber-optic rotary couplings that must be aligned and installed in conjunction with rotary bearings. Instead of being made to rotate in one direction at a steady speed as in a conventional rotational field mill, a split-cylinder or split-sphere electrode assembly in the proposed instrument would be set into rotational vibration like that of a metronome. The rotational vibration, synchronized with appropriate rapid electronic switching of electrical connections between electric-current-measuring circuitry and the split-cylinder or split-sphere electrodes, would result in an electrical measurement effect equivalent to that of a conventional rotational field mill. A version of the proposed instrument is described.

Counter-rotating accretion discs

NASA Astrophysics Data System (ADS)

Dyda, S.; Lovelace, R. V. E.; Ustyugova, G. V.; Romanova, M. M.; Koldoba, A. V.

2015-01-01

Counter-rotating discs can arise from the accretion of a counter-rotating gas cloud on to the surface of an existing corotating disc or from the counter-rotating gas moving radially inwards to the outer edge of an existing disc. At the interface, the two components mix to produce gas or plasma with zero net angular momentum which tends to free-fall towards the disc centre. We discuss high-resolution axisymmetric hydrodynamic simulations of viscous counter-rotating discs for the cases where the two components are vertically separated and radially separated. The viscosity is described by an isotropic α-viscosity including all terms in the viscous stress tensor. For the vertically separated components, a shear layer forms between them and the middle part of this layer free-falls to the disc centre. The accretion rates are increased by factors of ˜102-104 over that for a conventional disc rotating in one direction with the same viscosity. The vertical width of the shear layer and the accretion rate are strongly dependent on the viscosity and the mass fraction of the counter-rotating gas. In the case of radially separated components where the inner disc corotates and the outer disc rotates in the opposite direction, a gap between the two components opens and closes quasi-periodically. The accretion rates are ≳25 times larger than those for a disc rotating in one direction with the same viscosity.

Gold-nanoparticle-mediated jigsaw-puzzle-like assembly of supersized plasmonic DNA origami.

PubMed

Yao, Guangbao; Li, Jiang; Chao, Jie; Pei, Hao; Liu, Huajie; Zhao, Yun; Shi, Jiye; Huang, Qing; Wang, Lianhui; Huang, Wei; Fan, Chunhai

2015-03-02

DNA origami has rapidly emerged as a powerful and programmable method to construct functional nanostructures. However, the size limitation of approximately 100 nm in classic DNA origami hampers its plasmonic applications. Herein, we report a jigsaw-puzzle-like assembly strategy mediated by gold nanoparticles (AuNPs) to break the size limitation of DNA origami. We demonstrated that oligonucleotide-functionalized AuNPs function as universal joint units for the one-pot assembly of parent DNA origami of triangular shape to form sub-microscale super-origami nanostructures. AuNPs anchored at predefined positions of the super-origami exhibited strong interparticle plasmonic coupling. This AuNP-mediated strategy offers new opportunities to drive macroscopic self-assembly and to fabricate well-defined nanophotonic materials and devices. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Heavy quarkonium: progress, puzzles, and opportunities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brambilla, N; Heltsley, B K; Vogt, R

2011-02-01

A golden age for heavy quarkonium physics dawned a decade ago, initiated by the confluence of exciting advances in quantum chromodynamics (QCD) and an explosion of related experimental activity. The early years of this period were chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in 2004, which presented a comprehensive review of the status of the field at that time and provided specific recommendations for further progress. However, the broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles could only be partially anticipated. Since the release of the YR, the BESII program concluded only to give birthmore » to BESIII; the $B$-factories and CLEO-c flourished; quarkonium production and polarization measurements at HERA, JLab, and the Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the deconfinement regime. All these experiments leave legacies of quality, precision, and unsolved mysteries for quarkonium physics, and therefore beg for continuing investigations. The plethora of newly-found quarkonium-like states unleashed a flood of theoretical investigations into new forms of matter such as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the spectroscopy, decays, production, and in-medium behavior of c\\bar{c}, b\\bar{b}, and b\\bar{c} bound states have been shown to validate some theoretical approaches to QCD and highlight lack of quantitative success for others. The intriguing details of quarkonium suppression in heavy-ion collisions that have emerged from RHIC have elevated the importance of separating hot- and cold-nuclear-matter effects in quark-gluon plasma studies. This review systematically addresses all these matters and concludes by prioritizing directions for ongoing and future efforts.« less

Rotating stars in relativity.

PubMed

Paschalidis, Vasileios; Stergioulas, Nikolaos

2017-01-01

Rotating relativistic stars have been studied extensively in recent years, both theoretically and observationally, because of the information they might yield about the equation of state of matter at extremely high densities and because they are considered to be promising sources of gravitational waves. The latest theoretical understanding of rotating stars in relativity is reviewed in this updated article. The sections on equilibrium properties and on nonaxisymmetric oscillations and instabilities in f -modes and r -modes have been updated. Several new sections have been added on equilibria in modified theories of gravity, approximate universal relationships, the one-arm spiral instability, on analytic solutions for the exterior spacetime, rotating stars in LMXBs, rotating strange stars, and on rotating stars in numerical relativity including both hydrodynamic and magnetohydrodynamic studies of these objects.

The role of rotational hand movements and general motor ability in children's mental rotation performance.

PubMed

Jansen, Petra; Kellner, Jan

2015-01-01

Mental rotation of visual images of body parts and abstract shapes can be influenced by simultaneous motor activity. Children in particular have a strong coupling between motor and cognitive processes. We investigated the influence of a rotational hand movement performed by rotating a knob on mental rotation performance in primary school-age children (N = 83; age range: 7.0-8.3 and 9.0-10.11 years). In addition, we assessed the role of motor ability in this relationship. Boys in the 7- to 8-year-old group were faster when mentally and manually rotating in the same direction than in the opposite direction. For girls and older children this effect was not found. A positive relationship was found between motor ability and accuracy on the mental rotation task: stronger motor ability related to improved mental rotation performance. In both age groups, children with more advanced motor abilities were more likely to adopt motor processes to solve mental rotation tasks if the mental rotation task was primed by a motor task. Our evidence supports the idea that an overlap between motor and visual cognitive processes in children is influenced by motor ability.

Modeling of Prosthetic Limb Rotation Control by Sensing Rotation of Residual Arm Bone

PubMed Central

Kuiken, Todd A.

2011-01-01

We proposed a new approach to improve the control of prosthetic arm rotation in amputees. Arm rotation is sensed by implanting a small permanent magnet into the distal end of the residual bone, which produces a magnetic field. The position of the bone rotation can be derived from magnetic field distribution detected with magnetic sensors on the arm surface, and then conveyed to the prosthesis controller to manipulate the rotation of the prosthesis. Proprioception remains intact for residual limb skeletal structures; thus, this control system should be natural and easy-to-use. In this study, simulations have been conducted in an upper arm model to assess the feasibility and performance of sensing the voluntary rotation of residual humerus with an implanted magnet. A sensitivity analysis of the magnet size and arm size was presented. The influence of relative position of the magnet to the magnetic sensors, orientation of the magnet relative to the limb axis, and displacement of the magnetic sensors on the magnetic field was evaluated. The performance of shielding external magnetostatic interference was also investigated. The simulation results suggest that the direction and angle of rotation of residual humerus could be obtained by decoding the magnetic field signals with magnetic sensors built into a prosthetic socket. This pilot study provides important guidelines for developing a practical interface between the residual bone rotation and the prosthesis for control of prosthetic rotation. PMID:18713682

Rotations with Rodrigues' Vector

ERIC Educational Resources Information Center

Pina, E.

2011-01-01

The rotational dynamics was studied from the point of view of Rodrigues' vector. This vector is defined here by its connection with other forms of parametrization of the rotation matrix. The rotation matrix was expressed in terms of this vector. The angular velocity was computed using the components of Rodrigues' vector as coordinates. It appears…

Coherent perfect rotation

NASA Astrophysics Data System (ADS)

Crescimanno, Michael; Dawson, Nathan J.; Andrews, James H.

2012-09-01

Two classes of conservative, linear, optical rotary effects (optical activity and Faraday rotation) are distinguished by their behavior under time reversal. Faraday rotation, but not optical activity, is capable of coherent perfect rotation, by which we mean the complete transfer of counterpropagating coherent light fields into their orthogonal polarization. Unlike coherent perfect absorption, however, this process is explicitly energy conserving and reversible. Our study highlights the necessity of time-reversal-odd processes (not just absorption) and coherence in perfect mode conversion and thus informs the optimization of active multiport optical devices.

Rotated balance in humans due to repetitive rotational movement.

PubMed

Zakynthinaki, M S; Milla, J Madera; De Durana, A López Diaz; Martínez, C A Cordente; Romo, G Rodríguez; Quintana, M Sillero; Molinuevo, J Sampedro

2010-03-01

We show how asymmetries in the movement patterns during the process of regaining balance after perturbation from quiet stance can be modeled by a set of coupled vector fields for the derivative with respect to time of the angles between the resultant ground reaction forces and the vertical in the anteroposterior and mediolateral directions. In our model, which is an adaption of the model of Stirling and Zakynthinaki (2004), the critical curve, defining the set of maximum angles one can lean to and still correct to regain balance, can be rotated and skewed so as to model the effects of a repetitive training of a rotational movement pattern. For the purposes of our study a rotation and a skew matrix is applied to the critical curve of the model. We present here a linear stability analysis of the modified model, as well as a fit of the model to experimental data of two characteristic "asymmetric" elite athletes and to a "symmetric" elite athlete for comparison. The new adapted model has many uses not just in sport but also in rehabilitation, as many work place injuries are caused by excessive repetition of unaligned and rotational movement patterns.

Rotational wind indicator enhances control of rotated displays

NASA Technical Reports Server (NTRS)

Cunningham, H. A.; Pavel, Misha

1991-01-01

Rotation by 108 deg of the spatial mapping between a visual display and a manual input device produces large spatial errors in a discrete aiming task. These errors are not easily corrected by voluntary mental effort, but the central nervous system does adapt gradually to the new mapping. Bernotat (1970) showed that adding true hand position to a 90 deg rotated display improved performance of a compensatory tracking task, but tracking error rose again upon removal of the explicit cue. This suggests that the explicit error signal did not induce changes in the neural mapping, but rather allowed the operator to reduce tracking error using a higher mental strategy. In this report, we describe an explicit visual display enhancement applied to a 108 deg rotated discrete aiming task. A 'wind indicator' corresponding to the effect of the mapping rotation is displayed on the operator-controlled cursor. The human operator is instructed to oppose the virtual force represented by the indicator, as one would do if flying an airplane in a crosswind. This enhancement reduces spatial aiming error in the first 10 minutes of practice by an average of 70 percent when compared to a no enhancement control condition. Moreover, it produces adaptation aftereffect, which is evidence of learning by neural adaptation rather than by mental strategy. Finally, aiming error does not rise upon removal of the explicit cue.

Deck the Halls. Animated Displays III: Mechanical Puzzles.

ERIC Educational Resources Information Center

Pizzo, Joe, Ed.

1993-01-01

Describes an exhibit containing four basic demonstrations relating to center of gravity and rotational equilibrium. The demonstrations involve (1) the stack of bricks, (2) the double cone, (3) the spool roller, and (4) the platform balance. (MDH)

Coherent Perfect Rotation

NASA Astrophysics Data System (ADS)

Crescimanno, Michael; Dawson, Nathan; Andrews, James

2012-04-01

Two classes of conservative, linear, optical rotary effects (optical activity and Faraday rotation) are distinguished by their behavior under time reversal. In analogy with coherent perfect absorption, where counterpropagating light fields are controllably converted into other degrees of freedom, we show that in a linear-conservative medium only time-odd (Faraday) rotation is capable of coherent perfect rotation, by which we mean the complete transfer of counterpropagating coherent light fields into their orthogonal polarization. This highlights the necessity of time reversal odd processes (not just absorption) and coherence in perfect mode conversion and may inform device design.

Synergic effects of 10°/s constant rotation and rotating background on visual cognitive processing

NASA Astrophysics Data System (ADS)

He, Siyang; Cao, Yi; Zhao, Qi; Tan, Cheng; Niu, Dongbin

In previous studies we have found that constant low-speed rotation facilitated the auditory cognitive process and constant velocity rotation background sped up the perception, recognition and assessment process of visual stimuli. In the condition of constant low-speed rotation body is exposed into a new physical state. In this study the variations of human brain's cognitive process under the complex condition of constant low-speed rotation and visual rotation backgrounds with different speed were explored. 14 university students participated in the ex-periment. EEG signals were recorded when they were performing three different cognitive tasks with increasing mental load, that is no response task, selective switch responses task and selec-tive mental arithmetic task. Rotary chair was used to create constant low-speed10/srotation. Four kinds of background were used in this experiment, they were normal black background and constant 30o /s, 45o /s or 60o /s rotating simulated star background. The P1 and N1 compo-nents of brain event-related potentials (ERP) were analyzed to detect the early visual cognitive processing changes. It was found that compared with task performed under other backgrounds, the posterior P1 and N1 latencies were shortened under 45o /s rotating background in all kinds of cognitive tasks. In the no response task, compared with task performed under black back-ground, the posterior N1 latencies were delayed under 30o /s rotating background. In the selec-tive switch responses task and selective mental arithmetic task, compared with task performed under other background, the P1 latencies were lengthened under 60o /s rotating background, but the average amplitudes of the posterior P1 and N1 were increased. It was suggested that under constant 10/s rotation, the facilitated effect of rotating visual background were changed to an inhibited one in 30o /s rotating background. Under vestibular new environment, not all of the rotating backgrounds

Rotating and Binary Stars in General Relativit

NASA Astrophysics Data System (ADS)

Shapiro, Stuart

The inspiral and coalescence of compact binary stars is one of the most challenging problems in theoretical astrophysics. Only recently have advances in numerical relativity made it possible to explore this topic in full general relativity (GR). The mergers of compact binaries have important consequences for the detection of gravitational waves. In addition, the coalescence of binary neutron stars (NSNSs) and binary black-hole neutron stars (BHNSs) may hold the key for resolving other astrophysical puzzles, such as the origin of short-hard gamma-ray bursts (GRBs). While simulations of these systems in full GR are now possible, only the most idealized treatments have been performed to date. More detailed physics, including magnetic fields, black hole spin, a realistic hot, nuclear equation of state and neutrino transport must be incorporated. Only then will we be able to identify reliably future sources that may be detected simultaneously in gravitational waves and as GRBs. Likewise, the coalescence of binary black holes (BHBHs) is now a solved problem in GR, but only in vacuum. Simulating the coalescence of BHBHs in the gaseous environments likely to be found in nearby galaxy cores or in merging galaxies is crucial to identifying an electromagnetic signal that might accompany the gravitational waves produced during the merger. The coalescence of a binary white dwarf-neutron star (WDNS) has only recently been treated in GR, but GR is necessary to explore tidal disruption scenarios in which the capture of WD debris by the NS may lead to catastrophic collapse. Alternatively, the NS may survive and the merger might result in the formation of pulsar planets. The stability of rotating neutron stars in these and other systems has not been fully explored in GR, and the final fate of unstable stars has not been determined in many cases, especially in the presence of magnetic fields and differential rotation. These systems will be probed observationally by current NASA

Pre-registration house officer rotations incorporating general practice: does the order of rotation matter?

PubMed

Williams, C; Cantillon, P; Cochrane, M

2001-06-01

In relation to pre-registration house officer (PRHO) rotations incorporating general practice, previous research has recommended that where possible, no PRHO should undertake general practice as the first placement, because of the difficulties encountered. It was recognized that logistically, this could make such schemes almost unworkable. Within the context of a larger qualitative evaluation comparing how 24 PRHOs learned in hospital and general practice settings, the issue of rotation order was explored. In-depth semistructured interviews were conducted with the 12 PRHOs who were involved in general practice rotations. They were interviewed at the beginning and end of the PRHO year, and following their return to hospital work after the general practice placement. Each rotation order had both advantages and disadvantages, with no particular rotation order being obviously better or worse for the PRHOs involved. This small qualitative evaluation has highlighted a number of advantages and disadvantages specific to each rotation order, and makes some practical recommendations to help alleviate the problems encountered. It is important that future evaluations of similar schemes consider this issue, as there are conflicting reports about the significance of the rotation order.

How good a clock is rotation? The stellar rotation-mass-age relationship for old field stars

DOE Office of Scientific and Technical Information (OSTI.GOV)

Epstein, Courtney R.; Pinsonneault, Marc H., E-mail: epstein@astronomy.ohio-state.edu, E-mail: pinsono@astronomy.ohio-state.edu

2014-01-10

The rotation-mass-age relationship offers a promising avenue for measuring the ages of field stars, assuming the attendant uncertainties to this technique can be well characterized. We model stellar angular momentum evolution starting with a rotation distribution from open cluster M37. Our predicted rotation-mass-age relationship shows significant zero-point offsets compared to an alternative angular momentum loss law and published gyrochronology relations. Systematic errors at the 30% level are permitted by current data, highlighting the need for empirical guidance. We identify two fundamental sources of uncertainty that limit the precision of rotation-based ages and quantify their impact. Stars are born with amore » range of rotation rates, which leads to an age range at fixed rotation period. We find that the inherent ambiguity from the initial conditions is important for all young stars, and remains large for old stars below 0.6 M {sub ☉}. Latitudinal surface differential rotation also introduces a minimum uncertainty into rotation period measurements and, by extension, rotation-based ages. Both models and the data from binary star systems 61 Cyg and α Cen demonstrate that latitudinal differential rotation is the limiting factor for rotation-based age precision among old field stars, inducing uncertainties at the ∼2 Gyr level. We also examine the relationship between variability amplitude, rotation period, and age. Existing ground-based surveys can detect field populations with ages as old as 1-2 Gyr, while space missions can detect stars as old as the Galactic disk. In comparison with other techniques for measuring the ages of lower main sequence stars, including geometric parallax and asteroseismology, rotation-based ages have the potential to be the most precise chronometer for 0.6-1.0 M {sub ☉} stars.« less

Cohabitants' perspective on housing adaptations: a piece of the puzzle.

PubMed

Granbom, Marianne; Taei, Afsaneh; Ekstam, Lisa

2017-12-01

As part of the Swedish state-funded healthcare system, housing adaptations are used to promote safe and independent living for disabled people in ordinary housing through the elimination of physical environmental barriers in the home. The aim of this study was to describe the cohabitants' expectations and experiences of how a housing adaptation, intended for the partner, would impact their everyday life. In-depth interviews were conducted with cohabitants of nine people applying for a housing adaptation, initially at the time of the application and then again 3 months after the housing adaptation was installed. A longitudinal analysis was performed including analysis procedures from Grounded Theory. The findings revealed the expectations and experiences in four categories: partners' activities and independence; cohabitants' everyday activities and caregiving; couples' shared recreational/leisure activities; and housing decisions. A core category putting the intervention into perspective was called 'Housing adaptations - A piece of the puzzle'. From the cohabitants' perspective, new insights on housing adaptations emerged, which are important to consider when planning and carrying out successful housing adaptations. © 2017 Nordic College of Caring Science.

Visuomotor mental rotation of a saccade: The contingent negative variation scales to the angle of rotation.

PubMed

Heath, Matthew; Colino, Francisco L; Chan, Jillian; Krigolson, Olave E

2018-02-01

The visuomotor mental rotation (VMR) of a saccade requires a response to a region of space that is dissociated from a stimulus by a pre-specified angle, and work has shown a monotonic increase in reaction times as a function of increasing oblique angles of rotation. These results have been taken as evidence of a continuous process of rotation and have generated competing hypotheses. One hypothesis asserts that rotation is mediated via frontoparietal structures, whereas a second states that a continuous shift in the activity of direction-specific neurons in the superior colliculus (SC) supports rotation. Research to date, however, has not examined the neural mechanisms underlying VMR saccades and both hypotheses therefore remain untested. The present study measured the behavioural data and event-related brain potentials (ERP) of standard (i.e., 0° of rotation) and VMR saccades involving 35°, 70° and 105° of rotation. Behavioural results showed that participants adhered to task-based rotation demands and ERP findings showed that the amplitude of the contingent negative variation (CNV) linearly decreased with increasing angle of rotation. The cortical generators of the CNV are linked to frontoparietal structures supporting movement preparation. Although our ERP design does not allow us to exclude a possible role of the SC in the rotation of a VMR saccade, they do demonstrate that such actions are supported by a continuous and cortically based rotation process. Copyright © 2017 Elsevier Ltd. All rights reserved.

Shared Environment Estimates for Educational Attainment: A Puzzle and Possible Solutions.

PubMed

Freese, Jeremy; Jao, Yu-Han

2017-02-01

Classical behavioral genetics models for twin and other family designs decompose traits into heritability, shared environment, and nonshared environment components. Estimates of heritability of adult traits are pervasively observed to be far higher than those of shared environment, which has been used to make broad claims about the impotence of upbringing. However, the most commonly studied nondemographic variable in many areas of social science, educational attainment, exhibits robustly high estimates both for heritability and for shared environment. When previously noticed, the usual explanation has emphasized family resources, but evidence suggests this is unlikely to explain the anomalous high estimates for shared environment of educational attainment. We articulate eight potential complementary explanations and discuss evidence of their prospective contributions to resolving the puzzle. In so doing, we hope to further consideration of how behavioral genetics findings may advance studies of social stratification beyond the effort to articulate specific genetic influences. © 2015 Wiley Periodicals, Inc.

Completing the nuclear reaction puzzle of the nucleosynthesis of Mo 92

DOE PAGES

Tveten, G. M.; Spyrou, A.; Schwengner, R.; ...

2016-08-22

One of the greatest questions for modern physics to address is how elements heavier than iron are created in extreme astrophysical environments. A particularly challenging part of that question is the creation of the so-called p-nuclei, which are believed to be mainly produced in some types of supernovae. Here, the lack of needed nuclear data presents an obstacle in nailing down the precise site and astrophysical conditions. In this work, we present for the first time measurements on the nuclear level density and average γ strength function of 92Mo. State-of-the-art p-process calculations systematically underestimate the observed solar abundance of thismore » isotope. Our data provide stringent constraints on the 91Nb(p,γ) 92Mo reaction rate, which is the last unmeasured reaction in the nucleosynthesis puzzle of 92Mo. Based on our results, we conclude that the 92Mo abundance anomaly is not due to the nuclear physics input to astrophysical model calculations.« less

The role of rotational hand movements and general motor ability in children’s mental rotation performance

PubMed Central

Jansen, Petra; Kellner, Jan

2015-01-01

Mental rotation of visual images of body parts and abstract shapes can be influenced by simultaneous motor activity. Children in particular have a strong coupling between motor and cognitive processes. We investigated the influence of a rotational hand movement performed by rotating a knob on mental rotation performance in primary school-age children (N = 83; age range: 7.0–8.3 and 9.0–10.11 years). In addition, we assessed the role of motor ability in this relationship. Boys in the 7- to 8-year-old group were faster when mentally and manually rotating in the same direction than in the opposite direction. For girls and older children this effect was not found. A positive relationship was found between motor ability and accuracy on the mental rotation task: stronger motor ability related to improved mental rotation performance. In both age groups, children with more advanced motor abilities were more likely to adopt motor processes to solve mental rotation tasks if the mental rotation task was primed by a motor task. Our evidence supports the idea that an overlap between motor and visual cognitive processes in children is influenced by motor ability. PMID:26236262

A compact rotating dilution refrigerator

NASA Astrophysics Data System (ADS)

Fear, M. J.; Walmsley, P. M.; Chorlton, D. A.; Zmeev, D. E.; Gillott, S. J.; Sellers, M. C.; Richardson, P. P.; Agrawal, H.; Batey, G.; Golov, A. I.

2013-10-01

We describe the design and performance of a new rotating dilution refrigerator that will primarily be used for investigating the dynamics of quantized vortices in superfluid 4He. All equipment required to operate the refrigerator and perform experimental measurements is mounted on two synchronously driven, but mechanically decoupled, rotating carousels. The design allows for relative simplicity of operation and maintenance and occupies a minimal amount of space in the laboratory. Only two connections between the laboratory and rotating frames are required for the transmission of electrical power and helium gas recovery. Measurements on the stability of rotation show that rotation is smooth to around 10-3 rad s-1 up to angular velocities in excess of 2.5 rad s-1. The behavior of a high-Q mechanical resonator during rapid changes in rotation has also been investigated.

Sample rotating turntable kit for infrared spectrometers

DOEpatents

Eckels, Joel Del [Livermore, CA; Klunder, Gregory L [Oakland, CA

2008-03-04

An infrared spectrometer sample rotating turntable kit has a rotatable sample cup containing the sample. The infrared spectrometer has an infrared spectrometer probe for analyzing the sample and the rotatable sample cup is adapted to receive the infrared spectrometer probe. A reflectance standard is located in the rotatable sample cup. A sleeve is positioned proximate the sample cup and adapted to receive the probe. A rotator rotates the rotatable sample cup. A battery is connected to the rotator.

Factors affecting rotator cuff healing.

PubMed

Mall, Nathan A; Tanaka, Miho J; Choi, Luke S; Paletta, George A

2014-05-07

Several studies have noted that increasing age is a significant factor for diminished rotator cuff healing, while biomechanical studies have suggested the reason for this may be an inferior healing environment in older patients. Larger tears and fatty infiltration or atrophy negatively affect rotator cuff healing. Arthroscopic rotator cuff repair, double-row repairs, performing a concomitant acromioplasty, and the use of platelet-rich plasma (PRP) do not demonstrate an improvement in structural healing over mini-open rotator cuff repairs, single-row repairs, not performing an acromioplasty, or not using PRP. There is conflicting evidence to support postoperative rehabilitation protocols using early motion over immobilization following rotator cuff repair.

Dynamic Electrorheological Effects of Rotating Particles:

NASA Astrophysics Data System (ADS)

Yu, K. W.; Gu, G. Q.; Huang, J. P.; Xiao, J. J.

Particle rotation leads to a steady-state which is different from the equilibrium state in the absence of rotational motion. The change of the polarization of the particle due to the rotational motion is called the dynamic electrorheological effect (DER). There are three cases to be considered: rotating particles in a dc field, particle rotation due to a rotating field and spontaneous rotation of particle in dc field (Quincke rotation). In the DER of rotating particles, the particle rotational motion generally reduces the interparticle force between the particles. The effect becomes pronounced when the frequency is on the order of the relaxation rate of the surface charges. In the electrorotation of particles, the mutual interaction between approaching particles will change the electrorotation spectrum significantly. The electrorotation spectrum depends strongly on the medium conductivity as well as the conductivity contrast between the particle and the medium. In the collective behaviors of Quincke rotors, the mutual interactions between the individual rotors lead to the assembly of chain-like structures which make an angle with the applied field. This has an implication of a new class of material.

Rotating Connection for Electrical Cables

NASA Technical Reports Server (NTRS)

Manges, D. R.

1986-01-01

Cable reel provides electrical connections between fixed structure and rotating one. Reel carries power and signal lines while allowing rotating structure to turn up to 360 degrees with respect to fixed structure. Reel replaces sliprings. Can be used to electrically connect arm of robot with body. Reel releases cable to rotating part as it turns and takes up cable as rotating part comes back to its starting position, without tangling, twisting, or kinking.

Impact of rotation angle on crawling and non-crawling 9-month-old infants' mental rotation ability.

PubMed

Gerhard, Theresa M; Schwarzer, Gudrun

2018-06-01

The current study investigated whether 9-month-old infants' mental rotation performance was influenced by the magnitude of the angle of object rotation and their crawling ability. A total of 76 infants were tested; of these infants, 39 had been crawling for an average of 9.0 weeks. Infants were habituated to a video of a simplified Shepard-Metzler object (Shepard & Metzler, 1971), always rotating forward through a 180° angle around the horizontal axis of the object. After habituation, in two different test conditions, infants were presented with test videos of the same object rotating farther forward through a previously unseen 90° angle and with a test video of its mirror image. The two test conditions differed in the magnitude of the gap between the end of the habituation rotations and the beginning of the test rotations. The gaps were 0° and 54°. The results revealed that the mental rotation performance was influenced by the magnitude of the gaps only for the crawling infants. Their response showed significant transition from a preference for the mirror object rotations toward a preference for the familiar habituation object rotations. Thus, the results provide first evidence that it is easier for 9-month-old crawling infants to mentally rotate an object along a small angle compared with a large one. Copyright © 2018 Elsevier Inc. All rights reserved.

Anatomical glenohumeral internal rotation deficit and symmetric rotational strength in male and female young beach volleyball players.

PubMed

Saccol, Michele Forgiarini; Almeida, Gabriel Peixoto Leão; de Souza, Vivian Lima

2016-08-01

Beach volleyball is a sport with a high demand of shoulder structures that may lead to adaptations in range of motion (ROM) and strength like in other overhead sports. Despite of these possible alterations, no study evaluated the shoulder adaptations in young beach volleyball athletes. The aim of this study was to compare the bilateral ROM and rotation strength in the shoulders of young beach volleyball players. Goniometric passive shoulder ROM of motion and isometric rotational strength were evaluated in 19 male and 14 female asymptomatic athletes. External and internal ROM, total rotation motion, glenohumeral internal rotation deficit (GIRD), external rotation and internal rotation strength, bilateral deficits and external rotation to internal rotation ratio were measured. The statistical analysis included paired Student's t-test and analysis of variance with repeated measures. Significantly lower dominant GIRD was found in both groups (p<0.05), but only 6 athletes presented pathological GIRD. For strength variables, no significant differences for external or internal rotation were evident. Young beach volleyball athletes present symmetric rotational strength and shoulder ROM rotational adaptations that can be considered as anatomical. These results indicate that young practitioners of beach volleyball are subject to moderate adaptations compared to those reported for other overhead sports. Copyright © 2015 Elsevier Ltd. All rights reserved.

Infant perception of the rotating Kanizsa square.

PubMed

Yoshino, Daisuke; Idesawa, Masanori; Kanazawa, So; Yamaguchi, Masami K

2010-04-01

This study examined the perception of the rotating Kanizsa square by using a fixed-trial familiarization method. If the Kanizsa square is rotated across the pacmen, adult observers perceive not only a rotating illusory square, but also an illusory expansion/contraction motion of this square. The phenomenon is called a "rotational dynamic illusion". In experiments 1 and 2, we investigated whether infants perceived the rotational dynamic illusion, finding that 3-8-month-old infants perceived the rotational dynamic illusion as a simple rotation of the Kanizsa square. In experiment 3, we investigated whether infants perceived the rotational dynamic illusion as a rotation of the Kanizsa square or as a deformation of shape, finding that 3-4-month-old infants did perceive the rotational dynamic illusion as a rotation of the Kanizsa square. Our results show that while 3-8-month-old infants perceive the rotating Kanizsa square, however, it is difficult for the infants to extract expansion/contraction motion from the rotational dynamic illusion. Copyright 2010 Elsevier Inc. All rights reserved.

Modular Extracellular Matrices: Solutions for the Puzzle

PubMed Central

Serban, Monica A.; Prestwich, Glenn D.

2008-01-01

The common technique of growing cells in two-dimensions (2-D) is gradually being replaced by culturing cells on matrices with more appropriate composition and stiffness, or by encapsulation of cells in three-dimensions (3-D). The universal acceptance of the new 3-D paradigm has been constrained by the absence of a commercially available, biocompatible material that offers ease of use, experimental flexibility, and a seamless transition from in vitro to in vivo applications. The challenge – the puzzle that needs a solution – is to replicate the complexity of the native extracellular matrix (ECM) environment with the minimum number of components necessary to allow cells to rebuild and replicate a given tissue. For use in drug discovery, toxicology, cell banking, and ultimately in reparative medicine, the ideal matrix would therefore need to be highly reproducible, manufacturable, approvable, and affordable. Herein we describe the development of a set of modular components that can be assembled into biomimetic materials that meet these requirements. These semi-synthetic ECMs, or sECMs, are based on hyaluronan derivatives that form covalently crosslinked, biodegradable hydrogels suitable for 3-D culture of primary and stem cells in vitro, and for tissue formation in vivo. The sECMs can be engineered to provide appropriate biological cues needed to recapitulate the complexity of a given ECM environment. Specific applications for different sECM compositions include stem cell expansion with control of differentiation, scar-free wound healing, growth factor delivery, cell delivery for osteochondral defect and liver repair, and development of vascularized tumor xenografts for personalized chemotherapy. PMID:18442709

Towards a solution of the puzzle posed by superconducting SrTiO3

NASA Astrophysics Data System (ADS)

Malik, G. P.

2015-09-01

Suitably doped SrTiO3 was found in 1964 to undergo a superconducting transition below 1 K with a dome-like Tc versus n (electron concentration) plot. The apex of the dome — a point of inflection — corresponds to the point (n≈9 ×1019cm-3, Tc≈0.30 K). On either side of it, Tc goes down to ≈0.1 K for the extreme values between which n was varied. A single value of Tc is thus observed for two different values of n. The puzzle for the theory has been to explain this result. Treating the problem in all its generality, we present here three equations: the μ1-incorporated BCS equation for Tc, the μ0-incorporated equation for the T = 0 gap Δ0, where μ1 and μ0 are the chemical potentials at T = Tc and T = 0 respectively, and an equation that relates the interaction parameters λ1 and λ0 at these temperatures. Because there are five unknowns in the problem, we tackle these equations via an approximation scheme that includes setting μ1 = μ0 and λ1 = λ0. The latter of these is factually a basic tenet of the BCS theory. Salient features of our findings are: (i) the solutions for Tc and Δ0 on the RHS (LHS) of the dome correspond to μ> kBθD(μ < kBθD); kB = Boltzmann constant, θD = Debye temperature, (ii) for solutions on the LHS the limits of the integrals in the equations need to be curtailed to obtain real solutions and (iii) the point μ = kBθD is a point of inflection in the Tc versus μ plot. Since the puzzle has remained unsolved for a long time, we also offer here a purely mathematical model for λ(μ) — sans physical justification — which leads to a Tc versus μ plot qualitatively in agreement with experiment.

A comparative study of the A* heuristic search algorithm used to solve efficiently a puzzle game

NASA Astrophysics Data System (ADS)

Iordan, A. E.

2018-01-01

The puzzle game presented in this paper consists in polyhedra (prisms, pyramids or pyramidal frustums) which can be moved using the free available spaces. The problem requires to be found the minimum number of movements in order the game reaches to a goal configuration starting from an initial configuration. Because the problem is enough complex, the principal difficulty in solving it is given by dimension of search space, that leads to necessity of a heuristic search. The improving of the search method consists into determination of a strong estimation by the heuristic function which will guide the search process to the most promising side of the search tree. The comparative study is realized among Manhattan heuristic and the Hamming heuristic using A* search algorithm implemented in Java. This paper also presents the necessary stages in object oriented development of a software used to solve efficiently this puzzle game. The modelling of the software is achieved through specific UML diagrams representing the phases of analysis, design and implementation, the system thus being described in a clear and practical manner. With the purpose to confirm the theoretical results which demonstrates that Manhattan heuristic is more efficient was used space complexity criterion. The space complexity was measured by the number of generated nodes from the search tree, by the number of the expanded nodes and by the effective branching factor. From the experimental results obtained by using the Manhattan heuristic, improvements were observed regarding space complexity of A* algorithm versus Hamming heuristic.

Controllable High-Speed Rotation of Nanowires

NASA Astrophysics Data System (ADS)

Fan, D. L.; Zhu, F. Q.; Cammarata, R. C.; Chien, C. L.

2005-06-01

We report a versatile method for executing controllable high-speed rotation of nanowires by ac voltages applied to multiple electrodes. The rotation of the nanowires can be instantly switched on or off with precisely controlled rotation speed (to at least 1800 rpm), definite chirality, and total angle of rotation. We have determined the torque due to the fluidic drag force on nanowire of different lengths. We also demonstrate a micromotor using a rotating nanowire driving a dust particle into circular motion. This method has been used to rotate magnetic and nonmagnetic nanowires as well as carbon nanotubes.

Rotatable non-circular forebody flow controller

NASA Technical Reports Server (NTRS)

Moskovitz, Cary A. (Inventor)

1991-01-01

The invention is a rotatable, non-circular forebody flow controller. The apparatus comprises a small geometric device located at a nose of a forebody of an aircraft and a non-circular cross-sectional area that extends toward the apex of the aircraft. The device is symmetrical about a reference plane and preferably attaches to an axle which in turn attaches to a rotating motor. The motor rotates the device about an axis of rotation. Preferably, a control unit connected to an aircraft flight control computer signals to the rotating motor the proper rotational positioning of the geometric device.

Visual perception of axes of head rotation

PubMed Central

Arnoldussen, D. M.; Goossens, J.; van den Berg, A. V.

2013-01-01

Registration of ego-motion is important to accurately navigate through space. Movements of the head and eye relative to space are registered through the vestibular system and optical flow, respectively. Here, we address three questions concerning the visual registration of self-rotation. (1) Eye-in-head movements provide a link between the motion signals received by sensors in the moving eye and sensors in the moving head. How are these signals combined into an ego-rotation percept? We combined optic flow of simulated forward and rotational motion of the eye with different levels of eye-in-head rotation for a stationary head. We dissociated simulated gaze rotation and head rotation by different levels of eye-in-head pursuit. We found that perceived rotation matches simulated head- not gaze-rotation. This rejects a model for perceived self-rotation that relies on the rotation of the gaze line. Rather, eye-in-head signals serve to transform the optic flow's rotation information, that specifies rotation of the scene relative to the eye, into a rotation relative to the head. This suggests that transformed visual self-rotation signals may combine with vestibular signals. (2) Do transformed visual self-rotation signals reflect the arrangement of the semi-circular canals (SCC)? Previously, we found sub-regions within MST and V6+ that respond to the speed of the simulated head rotation. Here, we re-analyzed those Blood oxygenated level-dependent (BOLD) signals for the presence of a spatial dissociation related to the axes of visually simulated head rotation, such as have been found in sub-cortical regions of various animals. Contrary, we found a rather uniform BOLD response to simulated rotation along the three SCC axes. (3) We investigated if subject's sensitivity to the direction of the head rotation axis shows SCC axes specifcity. We found that sensitivity to head rotation is rather uniformly distributed, suggesting that in human cortex, visuo-vestibular integration is

SMAP Faraday Rotation

NASA Technical Reports Server (NTRS)

Le Vine, David

2016-01-01

Faraday rotation is a change in the polarization as signal propagates through the ionosphere. At L-band it is necessary to correct for this change and measurements are made on the spacecraft of the rotation angle. These figures show that there is good agreement between the SMAP measurements (blue) and predictions based on models (red).

[Rotator cuff tear athropathy prevalence].

PubMed

Guerra-Soriano, F; Encalada-Díaz, M I; Ruiz-Suárez, M; Valero-González, F S

2017-01-01

Glenohumeral arthritis secondary to massive rotator cuff tear presents with a superior displacement and femoralization of the humeral head with coracoacromial arch acetabularization. The purpose of this study was to establish prevalence of rotator cuff tear artropathy (CTA) at our institution. Four hundred electronic records were reviewed from which we identified 136 patients with rotator cuff tears. A second group was composed with patients with massive cuff tears that were analized and staged by the Seebauer cuff tear arthropathy classification. Thirty four patients with massive rotator cuff tears were identified, 8 male and 26 female (age 60.1 ± 10.26 years). Massive rotator cuff tear prevalence was 25%. CTA prevalence found in the rotator cuff group was 19 and 76% in the massive cuff tears group. Patients were staged according to the classification with 32% in stage 1a, 11% 1b, 32% 2a and 0% 2b. CTA prevalence in patients with rotator cuff tears and massive cuff tears is higher than the one reported in American population. We consider that a revision of the Seebauer classification to be appropriate to determine its reliability.

Power Harvesting from Rotation?

ERIC Educational Resources Information Center

Chicone, Carmen; Feng, Z. C.

2008-01-01

We show the impossibility of harvesting power from rotational motions by devices attached to the rotating object. The presentation is suitable for students who have studied Lagrangian mechanics. (Contains 2 figures.)

Rotating Aperture System

DOEpatents

Rusnak, Brian; Hall, James M.; Shen, Stewart; Wood, Richard L.

2005-01-18

A rotating aperture system includes a low-pressure vacuum pumping stage with apertures for passage of a deuterium beam. A stator assembly includes holes for passage of the beam. The rotor assembly includes a shaft connected to a deuterium gas cell or a crossflow venturi that has a single aperture on each side that together align with holes every rotation. The rotating apertures are synchronized with the firing of the deuterium beam such that the beam fires through a clear aperture and passes into the Xe gas beam stop. Portions of the rotor are lapped into the stator to improve the sealing surfaces, to prevent rapid escape of the deuterium gas from the gas cell.

Patellofemoral pain and asymmetrical hip rotation.

PubMed

Cibulka, Michael T; Threlkeld-Watkins, Julie

2005-11-01

Patellofemoral joint problems are the most common overuse injury of the lower extremity, and altered femoral or hip rotation may play a role in patellofemoral pain. The purpose of this case report is to describe the evaluation of and intervention for a patient with asymmetrical hip rotation and patellofemoral pain. The patient was a 15-year-old girl with an 8-month history of anterior right knee pain, without known trauma or injury. Prior to intervention, her score on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) was 24%. Right hip medial (internal) rotation was less than left hip medial rotation, and manual muscle testing showed weakness of the right hip internal rotator and abductor muscles. The intervention was aimed at increasing right hip medial rotation, improving right hip muscle strength (eg, the muscle force exerted by a muscle or a group of muscles to overcome a resistance), and eliminating anterior right knee pain. After 6 visits (14 days), passive left and right hip medial rotations were symmetrical, and her right hip internal rotator and abductor muscle grades were Good plus. Her WOMAC score was 0%. The patient had right patellofemoral pain and an uncommon pattern of asymmetrical hip rotation, with diminished hip medial rotation and excessive hip lateral (external) rotation on the right side. The patient's outcomes suggest that femoral or hip joint asymmetry may be related to patellofemoral joint pain.

Lunar Rotation, Orientation and Science

NASA Astrophysics Data System (ADS)

Williams, J. G.; Ratcliff, J. T.; Boggs, D. H.

2004-12-01

The Moon is the most familiar example of the many satellites that exhibit synchronous rotation. For the Moon there is Lunar Laser Ranging measurements of tides and three-dimensional rotation variations plus supporting theoretical understanding of both effects. Compared to uniform rotation and precession the lunar rotational variations are up to 1 km, while tidal variations are about 0.1 m. Analysis of the lunar variations in pole direction and rotation about the pole gives moment of inertia differences, third-degree gravity harmonics, tidal Love number k2, tidal dissipation Q vs. frequency, dissipation at the fluid-core/solid-mantle boundary, and emerging evidence for an oblate boundary. The last two indicate a fluid core, but a solid inner core is not ruled out. Four retroreflectors provide very accurate positions on the Moon. The experience with the Moon is a starting point for exploring the tides, rotation and orientation of the other synchronous bodies of the solar system.

Short-rotation plantations

Treesearch

Philip E. Pope; Jeffery O. Dawson

1989-01-01

Short-rotation plantations offer several advantages over longer, more traditional rotations. They enhance the natural productivity of better sites and of tree species with rapid juvenile growth. Returns on investment are realized in a shorter period and the risk of loss is reduced compared with long term investments. Production of wood and fiber can be maximized by...

Instability of counter-rotating stellar disks

NASA Astrophysics Data System (ADS)

Hohlfeld, R. G.; Lovelace, R. V. E.

2015-09-01

We use an N-body simulation, constructed using GADGET-2, to investigate an accretion flow onto an astrophysical disk that is in the opposite sense to the disk's rotation. In order to separate dynamics intrinsic to the counter-rotating flow from the impact of the flow onto the disk, we consider an initial condition in which the counter-rotating flow is in an annular region immediately exterior the main portion of the astrophysical disk. Such counter-rotating flows are seen in systems such as NGC 4826 (known as the "Evil Eye Galaxy"). Interaction between the rotating and counter-rotating components is due to two-stream instability in the boundary region. A multi-armed spiral density wave is excited in the astrophysical disk and a density distribution with high azimuthal mode number is excited in the counter-rotating flow. Density fluctuations in the counter-rotating flow aggregate into larger clumps and some of the material in the counter-rotating flow is scattered to large radii. Accretion flow processes such as this are increasingly seen to be of importance in the evolution of multi-component galactic disks.

Disentangling rotational velocity distribution of stars

NASA Astrophysics Data System (ADS)

Curé, Michel; Rial, Diego F.; Cassetti, Julia; Christen, Alejandra

2017-11-01

Rotational speed is an important physical parameter of stars: knowing the distribution of stellar rotational velocities is essential for understanding stellar evolution. However, rotational speed cannot be measured directly and is instead the convolution between the rotational speed and the sine of the inclination angle vsin(i). The problem itself can be described via a Fredhoml integral of the first kind. A new method (Curé et al. 2014) to deconvolve this inverse problem and obtain the cumulative distribution function for stellar rotational velocities is based on the work of Chandrasekhar & Münch (1950). Another method to obtain the probability distribution function is Tikhonov regularization method (Christen et al. 2016). The proposed methods can be also applied to the mass ratio distribution of extrasolar planets and brown dwarfs (in binary systems, Curé et al. 2015). For stars in a cluster, where all members are gravitationally bounded, the standard assumption that rotational axes are uniform distributed over the sphere is questionable. On the basis of the proposed techniques a simple approach to model this anisotropy of rotational axes has been developed with the possibility to ``disentangling'' simultaneously both the rotational speed distribution and the orientation of rotational axes.

Rotational Spectrum of Sarin

NASA Astrophysics Data System (ADS)

Walker, A. R. Hight; Suenram, R. D.; Samuels, Alan; Jensen, James; Ellzy, Michael W.; Lochner, J. Michael; Zeroka, Daniel

2001-05-01

As part of an effort to examine the possibility of using molecular-beam Fourier-transform microwave spectroscopy to unambiguously detect and monitor chemical warfare agents, we report the first observation and assignment of the rotational spectrum of the nerve agent Sarin (GB) (Methylphosphonofluoridic acid 1-methyl-ethyl ester, CAS #107-44-8) at frequencies between 10 and 22 GHz. Only one of the two low-energy conformers of this organophosphorus compound (C4H10FO2P) was observed in the rotationally cold (Trot<2 K) molecular beam. The experimental asymmetric-rotor ground-state rotational constants of this conformer are A=2874.0710(9) MHz, B=1168.5776(4) MHz, C=1056.3363(4) MHz (Type A standard uncertainties are given, i.e., 1σ), as obtained from a least-squares analysis of 74 a-, b-, and c-type rotational transitions. Several of the transitions are split into doublets due to the internal rotation of the methyl group attached to the phosphorus. The three-fold-symmetry barrier to internal rotation estimated from these splittings is 677.0(4) cm-1. Ab initio electronic structure calculations using Hartree-Fock, density functional, and Moller-Plesset perturbation theories have also been made. The structure of the lowest-energy conformer determined from a structural optimization at the MP2/6-311G** level of theory is consistent with our experimental findings.

Separating "Rotators" from "Nonrotators" in the Mental Rotations Test: A Multigroup Latent Class Analysis

ERIC Educational Resources Information Center

Geiser, Christian; Lehmann, Wolfgang; Eid, Michael

2006-01-01

Items of mental rotation tests can not only be solved by mental rotation but also by other solution strategies. A multigroup latent class analysis of 24 items of the Mental Rotations Test (MRT) was conducted in a sample of 1,695 German pupils and students to find out how many solution strategies can be identified for the items of this test. The…

Rotating plug bearing and seal

DOEpatents

Wade, Elman E.

1977-01-01

A bearing and seal structure for nuclear reactors utilizing rotating plugs above the nuclear reactor vessel. The structure permits lubrication of bearings and seals of the rotating plugs without risk of the lubricant draining into the reactor vessel below. The structure permits lubrication by utilizing a rotating outer race bearing.

Staff rotation: implications for occupational therapy.

PubMed

Taylor, A; Andriuk, M L; Langlois, P; Provost, E

1995-10-01

Occupational therapy departments of tertiary care hospitals can provide staff with opportunities to gain diverse clinical experience if they rotate through the various services such as surgery, medicine, geriatrics, plastic surgery and orthopaedics. The system of rotation offers both advantages and disadvantages for the staff and the institution. The Royal Victoria Hospital in Montreal, a large university teaching hospital, had traditionally offered staff the opportunity to rotate. Changes in staffing and their needs however, resulted in rotation becoming an important issue within the department. This article presents the pros and the cons of rotation and non-rotation systems as identified by therapists and administrators across Canada. Staff rotation was found to have an effect on job satisfaction and a therapist's career orientation. Given these findings, administrators may want to reconsider the role of the generalist and specialist in their facilities.

RED DWARF DYNAMO RAISES PUZZLE OVER INTERIORS OF LOWEST-MASS STARS

NASA Technical Reports Server (NTRS)

2002-01-01

-years away in the constellation Aquila. Gliese 752A is a red dwarf that is one-third the mass of the Sun and slightly more than half its diameter. By contrast, VB10 is physically smaller than the planet Jupiter and only about nine percent the mass of our Sun. This very faint star is near the threshold of the lowest possible mass for a true star (.08 solar masses), below which nuclear fusion processes cannot take place according to current models. A team led by Linsky used Hubble's Goddard High Resolution Spectrograph (GHRS) to make a one-hour long exposure of VB10 on October 12, 1994. No detectable ultraviolet emission was seen until the last five minutes, when bright emission was detected in a flare. Though the star's normal surface temperature is 4,500 degrees Fahrenheit, Hubble's GHRS detected a sudden burst of 270,000 degrees Fahrenheit in the star's outer atmosphere. Linsky attributes this rapid heating to the presence of an intense, but unstable, magnetic field. THE INTERIOR WORKINGS OF A STELLAR DYNAMO Before the Hubble observation, astronomers thought magnetic fields in stars required the same dynamo process which creates magnetic fields on the Sun. In the classic solar model, heat generated by nuclear fusion reactions at the star's center escapes through a radiative zone just outside the core. The heat travels from the radiative core to the star's surface through a convection zone. In this region, heat bubbles to the surface by motions similar to boiling in a pot of water. Dynamos, which accelerate electrons to create magnetic forces, operate when the interior of a star rotates faster than the surface. Recent studies of the Sun indicate its convective zone rotates at nearly the same rate at all depths. This means the solar dynamo must operate in the more rapidly rotating radiative core just below the convective zone. The puzzle is that stars below 20 percent the mass of our Sun do not have radiative cores, but instead transport heat from their core through

Precision grip responses to unexpected rotational perturbations scale with axis of rotation.

PubMed

De Gregorio, Michael; Santos, Veronica J

2013-04-05

It has been established that rapid, pulse-like increases in precision grip forces ("catch-up responses") are elicited by unexpected translational perturbations and that response latency and strength scale according to the direction of linear slip relative to the hand as well as gravity. To determine if catch-up responses are elicited by unexpected rotational perturbations and are strength-, axis-, and/or direction-dependent, we imposed step torque loads about each of two axes which were defined relative to the subject's hand: the distal-proximal axis away from and towards the subject's palm, and the grip axis which connects the two fingertips. Precision grip responses were dominated initially by passive mechanics and then by active, unimodal catch-up responses. First dorsal interosseous activity, marking the start of the catch-up response, began 71-89 ms after the onset of perturbation. The onset latency, shape, and duration (217-231 ms) of the catch-up response were not affected by the axis, direction, or magnitude of the rotational perturbation, while strength was scaled by axis of rotation and slip conditions. Rotations about the grip axis that tilted the object away from the palm and induced rotational slip elicited stronger catch-up responses than rotations about the distal-proximal axis that twisted the object between the digits. To our knowledge, this study is the first to investigate grip responses to unexpected torque loads and to show characteristic, yet axis-dependent, catch-up responses for conditions other than pure linear slip. Copyright © 2013 Elsevier Ltd. All rights reserved.

Rotational velocities of A-type stars. IV. Evolution of rotational velocities

NASA Astrophysics Data System (ADS)

Zorec, J.; Royer, F.

2012-01-01

Context. In previous works of this series, we have shown that late B- and early A-type stars have genuine bimodal distributions of rotational velocities and that late A-type stars lack slow rotators. The distributions of the surface angular velocity ratio Ω/Ωcrit (Ωcrit is the critical angular velocity) have peculiar shapes according to spectral type groups, which can be caused by evolutionary properties. Aims: We aim to review the properties of these rotational velocity distributions in some detail as a function of stellar mass and age. Methods: We have gathered vsini for a sample of 2014 B6- to F2-type stars. We have determined the masses and ages for these objects with stellar evolution models. The (Teff,log L/L⊙)-parameters were determined from the uvby-β photometry and the HIPPARCOS parallaxes. Results: The velocity distributions show two regimes that depend on the stellar mass. Stars less massive than 2.5 M⊙ have a unimodal equatorial velocity distribution and show a monotonical acceleration with age on the main sequence (MS). Stars more massive have a bimodal equatorial velocity distribution. Contrarily to theoretical predictions, the equatorial velocities of stars from about 1.7 M⊙ to 3.2 M⊙ undergo a strong acceleration in the first third of the MS evolutionary phase, while in the last third of the MS they evolve roughly as if there were no angular momentum redistribution in the external stellar layers. The studied stars might start in the ZAMS not necessarily as rigid rotators, but with a total angular momentum lower than the critical one of rigid rotators. The stars seem to evolve as differential rotators all the way of their MS life span and the variation of the observed rotational velocities proceeds with characteristic time scales δt ≈ 0.2 tMS, where tMS is the time spent by a star in the MS. Full Table 1 is only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http

Calculation of impurity poloidal rotation from measured poloidal asymmetries in the toroidal rotation of a tokamak plasma.

PubMed

Chrystal, C; Burrell, K H; Grierson, B A; Groebner, R J; Kaplan, D H

2012-10-01

To improve poloidal rotation measurement capabilities on the DIII-D tokamak, new chords for the charge exchange recombination spectroscopy (CER) diagnostic have been installed. CER is a common method for measuring impurity rotation in tokamak plasmas. These new chords make measurements on the high-field side of the plasma. They are designed so that they can measure toroidal rotation without the need for the calculation of atomic physics corrections. Asymmetry between toroidal rotation on the high- and low-field sides of the plasma is used to calculate poloidal rotation. Results for the main impurity in the plasma are shown and compared with a neoclassical calculation of poloidal rotation.

Sleep disturbance associated with rotator cuff tear: correction with arthroscopic rotator cuff repair.

PubMed

Austin, Luke; Pepe, Matthew; Tucker, Bradford; Ong, Alvin; Nugent, Robert; Eck, Brandon; Tjoumakaris, Fotios

2015-06-01

Sleep disturbance is a common complaint of patients with a rotator cuff tear. Inadequate and restless sleep, along with pain, is often a driving symptom for patients to proceed with rotator cuff repair. To date, no studies have examined sleep disturbance in patients undergoing rotator cuff repair, and there is no evidence that surgery improves sleep disturbance. Sleep disturbance is prevalent in patients with a symptomatic rotator cuff tear, and sleep disturbance improves after arthroscopic rotator cuff repair. Case series; Level of evidence, 4. A total of 56 patients undergoing arthroscopic rotator cuff repair for full-thickness tears were enrolled in a prospective study. Patients were surveyed preoperatively and postoperatively at intervals of 2, 6, 12, 18, and 24 weeks. Patient outcomes were scored using the Pittsburgh Sleep Quality Index (PSQI), Simple Shoulder Test (SST), visual analog scale for pain (VAS), and single assessment numeric evaluation (SANE). Demographic and surgical factors were also collected for analysis. Preoperative PSQI scores indicative of sleep disturbance were reported in 89% of patients. After surgery, a statistically significant improvement in PSQI was achieved at 3 months (P = .0012; 91% follow-up) and continued through 6 months (P = .0179; 93% follow-up). Six months after surgery, only 38% of patients continued to have sleep disturbance. Multivariable linear regression of all surgical and demographic factors versus PSQI was performed and demonstrated that preoperative and prolonged postoperative narcotic use negatively affected sleep. Sleep disturbance is common in patients undergoing rotator cuff repair. After surgery, sleep disturbance improves to levels comparable with those of the general public. Preoperative and prolonged postoperative use of narcotic pain medication negatively affects sleep. © 2015 The Author(s).

Rotation Flaps-Principles and Locations.

PubMed

LoPiccolo, Matteo C

2015-10-01

The rotation flap is a classic method of tissue rearrangement. It is a simple yet effective tool for recruiting tissue from areas of laxity and redirecting vectors of tension to reconstruct wounds not amenable to primary closure. This article presents the basic design principles and specific applications of the rotation flap in dermatologic surgery. A Medline search of articles describing rotation flaps published prior to April 1, 2015 was performed, and several prominent texts in dermatologic surgery were reviewed. Information gathered from the above sources is combined with the clinical experience of the author and editors to present surgeons with a guide for planning and executing various rotation flaps. Mastering the technique of the rotation flap will allow a surgeon to repair a wide variety of cutaneous defects.

Rotating-disk sorptive extraction: effect of the rotation mode of the extraction device on mass transfer efficiency.

PubMed

Jachero, Lourdes; Ahumada, Inés; Richter, Pablo

2014-05-01

The extraction device used in rotating-disk sorptive extraction consists of a Teflon disk in which a sorptive phase is fixed on one of its surfaces. Depending on the configuration, the rotation axis of the disk device can be either perpendicular or parallel to its radius, giving rise to two different mass transfer patterns when rotating-disk sorptive extraction is applied in liquid samples. In the perpendicular case (configuration 1), which is the typical configuration, the disk contains an embedded miniature stir bar that allows the disk rotation to be driven using a common laboratory magnetic stirrer. In the parallel case (configuration 2), the disk is driven by a rotary rod connected to an electric stirrer. In this study, triclosan and its degradation product methyl triclosan were used as analyte models to demonstrate the significant effect of the rotation configuration of the disk on the efficiency of analyte mass transfer from water to a sorptive phase of polydimethylsiloxane. Under the same experimental conditions and at a rotation velocity of 1,250 rpm, extraction equilibrium was reached at 80 min when the disk was rotated in configuration 1 and at 30 min when the disk was rotated in configuration 2. The extraction equilibration time decreased to 14 min when the rotation velocity was increased to 2,000 rpm in configuration 2. Because the rotation pattern affects the mass transfer efficiency, each rotation configuration was characterized through the Reynolds number; Re values of 6,875 and 16,361 were achieved with configurations 1 and 2, respectively, at 1,250 rpm.

Rotational Spectrum and Internal Rotation Barrier of 1-Chloro-1,1-difluoroethane

NASA Astrophysics Data System (ADS)

Alonso, José L.; López, Juan C.; Blanco, Susana; Guarnieri, Antonio

1997-03-01

The rotational spectra of 1-chloro-1,1-difluoroethane (HCFC-142b) has been investigated in the frequency region 8-115 GHz with Stark, waveguide Fourier transform (FTMW), and millimeter-wave spectrometers. Assignments in large frequency regions with the corresponding frequency measurements have been made for the ground andv18= 1 (CH3torsion) vibrational states of the35Cl isotopomer and for the ground state of the37Cl species. Accurate rotational, quartic centrifugal distortion, and quadrupole coupling constants have been determined from global fits considering all these states. SmallA-Einternal rotation splittings have been observed for thev18= 1 vibrational state using FTMW spectroscopy. The barrier height for the internal rotation of the methyl group has been determined to be 3751 (4) cal mol-1, in disagreement with the previous microwave value of 4400 (100) cal mol-1reported by G. Graner and C. Thomas [J. Chem. Phys.49,4160-4167 (1968)].

Rotation of an optically trapped vaterite microsphere measured using rotational Doppler effect

NASA Astrophysics Data System (ADS)

Chen, Xinlin; Xiao, Guangzong; Xiong, Wei; Yang, Kaiyong; Luo, Hui; Yao, Baoli

2018-03-01

The angular velocity of a vaterite microsphere spinning in the optical trap is measured using rotational Doppler effect. The perfectly spherical vaterite microspheres are synthesized via coprecipitation in the presence of silk fibroin nanospheres. When trapped by a circularly polarized beam, the vaterite microsphere is uniformly rotated in the trap center. The probe beams containing two Laguerre-Gaussian beams of opposite topological charge l = ± 7, l = ± 8, and l = ± 9 are illuminated on the spinning vaterite. By analyzing the backscattered light, a frequency shift is observed scaling with the rotation rate of the vaterite microsphere. The multiplicative enhancement of the frequency shift proportion to the topological charge has greatly improved the measurement precision. The reliability and practicability of this approach are verified through varying the topological charge of the probe beam and the trapping laser power. In consideration of the excellent measurement precision of the rotation frequency, this technique might be generally applicable in studying the torsional properties of micro-objects.

Rotational Spectrum of Sarin.

PubMed

Walker, A. R. Hight; Suenram, R. D.; Samuels, Alan; Jensen, James; Ellzy, Michael W.; Lochner, J. Michael; Zeroka, Daniel

2001-05-01

As part of an effort to examine the possibility of using molecular-beam Fourier-transform microwave spectroscopy to unambiguously detect and monitor chemical warfare agents, we report the first observation and assignment of the rotational spectrum of the nerve agent Sarin (GB) (Methylphosphonofluoridic acid 1-methyl-ethyl ester, CAS #107-44-8) at frequencies between 10 and 22 GHz. Only one of the two low-energy conformers of this organophosphorus compound (C(4)H(10)FO(2)P) was observed in the rotationally cold (T(rot)<2 K) molecular beam. The experimental asymmetric-rotor ground-state rotational constants of this conformer are A=2874.0710(9) MHz, B=1168.5776(4) MHz, C=1056.3363(4) MHz (Type A standard uncertainties are given, i.e., 1sigma), as obtained from a least-squares analysis of 74 a-, b-, and c-type rotational transitions. Several of the transitions are split into doublets due to the internal rotation of the methyl group attached to the phosphorus. The three-fold-symmetry barrier to internal rotation estimated from these splittings is 677.0(4) cm(-1). Ab initio electronic structure calculations using Hartree-Fock, density functional, and Moller-Plesset perturbation theories have also been made. The structure of the lowest-energy conformer determined from a structural optimization at the MP2/6-311G(**) level of theory is consistent with our experimental findings. Copyright 2001 Academic Press.

Rigid rotators. [deriving the time-independent energy states associated with rotational motions of the molecule

NASA Technical Reports Server (NTRS)

1976-01-01

The two-particle, steady-state Schroedinger equation is transformed to center of mass and internuclear distance vector coordinates, leading to the free particle wave equation for the kinetic energy motion of the molecule and a decoupled wave equation for a single particle of reduced mass moving in a spherical potential field. The latter describes the vibrational and rotational energy modes of the diatomic molecule. For fixed internuclear distance, this becomes the equation of rigid rotator motion. The classical partition function for the rotator is derived and compared with the quantum expression. Molecular symmetry effects are developed from the generalized Pauli principle that the steady-state wave function of any system of fundamental particles must be antisymmetric. Nuclear spin and spin quantum functions are introduced and ortho- and para-states of rotators, along with their degeneracies, are defined. Effects of nuclear spin on entropy are deduced. Next, rigid polyatomic rotators are considered and the partition function for this case is derived. The patterns of rotational energy levels for nonlinear molecules are discussed for the spherical symmetric top, for the prolate symmetric top, for the oblate symmetric top, and for the asymmetric top. Finally, the equilibrium energy and specific heat of rigid rotators are derived.

Enstrophy-based proper orthogonal decomposition of flow past rotating cylinder at super-critical rotating rate

NASA Astrophysics Data System (ADS)

Sengupta, Tapan K.; Gullapalli, Atchyut

2016-11-01

Spinning cylinder rotating about its axis experiences a transverse force/lift, an account of this basic aerodynamic phenomenon is known as the Robins-Magnus effect in text books. Prandtl studied this flow by an inviscid irrotational model and postulated an upper limit of the lift experienced by the cylinder for a critical rotation rate. This non-dimensional rate is the ratio of oncoming free stream speed and the surface speed due to rotation. Prandtl predicted a maximum lift coefficient as CLmax = 4π for the critical rotation rate of two. In recent times, evidences show the violation of this upper limit, as in the experiments of Tokumaru and Dimotakis ["The lift of a cylinder executing rotary motions in a uniform flow," J. Fluid Mech. 255, 1-10 (1993)] and in the computed solution in Sengupta et al. ["Temporal flow instability for Magnus-robins effect at high rotation rates," J. Fluids Struct. 17, 941-953 (2003)]. In the latter reference, this was explained as the temporal instability affecting the flow at higher Reynolds number and rotation rates (>2). Here, we analyze the flow past a rotating cylinder at a super-critical rotation rate (=2.5) by the enstrophy-based proper orthogonal decomposition (POD) of direct simulation results. POD identifies the most energetic modes and helps flow field reconstruction by reduced number of modes. One of the motivations for the present study is to explain the shedding of puffs of vortices at low Reynolds number (Re = 60), for the high rotation rate, due to an instability originating in the vicinity of the cylinder, using the computed Navier-Stokes equation (NSE) from t = 0 to t = 300 following an impulsive start. This instability is also explained through the disturbance mechanical energy equation, which has been established earlier in Sengupta et al. ["Temporal flow instability for Magnus-robins effect at high rotation rates," J. Fluids Struct. 17, 941-953 (2003)].

On the Product of Rotations

ERIC Educational Resources Information Center

Trenkler, G.; Trenkler, D.

2008-01-01

Using the elementary tools of matrix theory, we show that the product of two rotations in the three-dimensional Euclidean space is a rotation again. For this purpose, three types of rotation matrices are identified which are of simple structure. One of them is the identity matrix, and each of the other two types can be uniquely characterized by…

Chaotic rotation of Hyperion?

NASA Technical Reports Server (NTRS)

Binzel, R. P.; Green, J. R.; Opal, C. B.

1986-01-01

Thomas et al. (1984) analyzed 14 Voyager 2 images of Saturn's satellite Hyperion and interpreted them to be consistent with a coherent (nonchaotic) rotation period of 13.1 days. This interpretation was criticized by Peale and Wisdom (1984), who argued that the low sampling frequency of Voyager data does not allow chaotic or nonchaotic rotation to be distinguished. New observations obtained with a higher sampling frequency are reported here which conclusively show that the 13.1 day period found by Thomas et al. was not due to coherent rotation.

In-line rotating capacitive torque sensor

DOEpatents

Kronberg, James W.

1991-01-01

A method and apparatus for measuring torques developed along a rotating mechanical assembly comprising a rotating inner portion and a stationary outer portion. The rotating portion has an electrically-conductive flexing section fitted between two coaxial shafts in a configuration which varies radially in accordance with applied torque. The stationary portion comprises a plurality of conductive plates forming a surface concentric with and having a diameter slightly larger than the diameter of the rotating portion. The capacitance between the outer, nonrotating and inner, rotating portion varies with changes in the radial configuration of the rotating portion. Signal output varies approximately linearly with torque for small torques, nonlinearly for larger torques. The sensor is preferably surrounded by a conductive shell to minimize electrical interference from external sources.

Fanconi Anemia Proteins and Their Interacting Partners: A Molecular Puzzle

PubMed Central

Kaddar, Tagrid; Carreau, Madeleine

2012-01-01

In recent years, Fanconi anemia (FA) has been the subject of intense investigations, primarily in the DNA repair research field. Many discoveries have led to the notion of a canonical pathway, termed the FA pathway, where all FA proteins function sequentially in different protein complexes to repair DNA cross-link damages. Although a detailed architecture of this DNA cross-link repair pathway is emerging, the question of how a defective DNA cross-link repair process translates into the disease phenotype is unresolved. Other areas of research including oxidative metabolism, cell cycle progression, apoptosis, and transcriptional regulation have been studied in the context of FA, and some of these areas were investigated before the fervent enthusiasm in the DNA repair field. These other molecular mechanisms may also play an important role in the pathogenesis of this disease. In addition, several FA-interacting proteins have been identified with roles in these “other” nonrepair molecular functions. Thus, the goal of this paper is to revisit old ideas and to discuss protein-protein interactions related to other FA-related molecular functions to try to give the reader a wider perspective of the FA molecular puzzle. PMID:22737580

Puzzling features of western Mediterranean tectonics explained by slab dragging

NASA Astrophysics Data System (ADS)

Spakman, Wim; Chertova, Maria V.; van den Berg, Arie.; van Hinsbergen, Douwe J. J.

2018-03-01

The recent tectonic evolution of the western Mediterranean region is enigmatic. The causes for the closure of the Moroccan marine gateway prior to the Messinian salinity crisis, for the ongoing shortening of the Moroccan Rif and for the origin of the seismogenic Trans-Alboran shear zone and eastern Betics extension are unclear. These puzzling tectonic features cannot be fully explained by subduction of the east-dipping Gibraltar slab in the context of the regional relative plate motion frame. Here we use a combination of geological and geodetic data, as well as three-dimensional numerical modelling of subduction, to show that these unusual tectonic features could be the consequence of slab dragging—the north to north-eastward dragging of the Gibraltar slab by the absolute motion of the African Plate. Comparison of our model results to patterns of deformation in the western Mediterranean constrained by geological and geodetic data confirm that slab dragging provides a plausible mechanism for the observed deformation. Our results imply that the impact of absolute plate motion on subduction is identifiable from crustal observations. Identifying such signatures elsewhere may improve the mantle reference frame and provide insights on subduction evolution and associated crustal deformation.

Acoustic controlled rotation and orientation

NASA Technical Reports Server (NTRS)

Barmatz, Martin B. (Inventor); Allen, James L. (Inventor)

1989-01-01

Acoustic energy is applied to a pair of locations spaced about a chamber, to control rotation of an object levitated in the chamber. Two acoustic transducers applying energy of a single acoustic mode, one at each location, can (one or both) serve to levitate the object in three dimensions as well as control its rotation. Slow rotation is achieved by initially establishing a large phase difference and/or pressure ratio of the acoustic waves, which is sufficient to turn the object by more than 45 deg, which is immediately followed by reducing the phase difference and/or pressure ratio to maintain slow rotation. A small phase difference and/or pressure ratio enables control of the angular orientation of the object without rotating it. The sphericity of an object can be measured by its response to the acoustic energy.

Global Analysis of Broadband Rotation and Vibration-Rotation Spectra of Sulfur Dicyanide

NASA Astrophysics Data System (ADS)

Kisiel, Zbigniew; Winnewissser, Manfred; Winnewisser, Brenda P.; De Lucia, Frank C.; Tokaryk, Dennis W.; Billinghurst, Brant E.

2013-06-01

The successful analysis of the quantum monodromy induced features in the rotational spectrum of the NCNCS molecule prompted a quest for similar behaviour in its vibration-rotation spectrum and several high-resolution FT-IR spectra were recorded on the IFS125HR interferometer at the Canadian Light Source. The sulfur dicyanide, S(CN)_2, molecule is a precursor to NCNCS and the analysis of its spectrum proved to be a prerequisite to a search for the elusive NCNCS transitions. The CLS spectra provided the opportunity to augment the previous extensive analysis of the FASSST rotational spectrum of S(CN)_2 with vibration-rotation data, in particular from the ν_4 fundamental at 121 cm^{-1} and its related hot-band series. A global fit of the two data sets allowed retaining the detailed analysis of the previously reported perturbations in the 3ν_4 triad and 4ν_4 tetrad of states, while allowing for determination of precise energies of all low-lying vibrational states of S(CN)_2. In this way we have determined wavenumbers for five lowest fundamentals of this experimentally difficult molecule and obtained an extensive set of benchmark data for calibration of anharmonic force field calculations of such quantities as the vibration-rotation changes in rotational constants, and anharmonicity coefficients. Comparisons with results of several such calculations are presented. B.P.Winnewisser, et al., Phys. Chem. Chem. Phys. {12}, 8158 (2010). M.Winnewisser et al., 67^th OSU Symposium on Molecular Spectroscopy, The Ohio State University, Ohio 2012, TF-01. Z.Kisiel et al., J. Mol. Spectrosc. {246}, 39 (2007).

High-Current Rotating Contactor

NASA Technical Reports Server (NTRS)

Hagan, David W.; Wolff, Edwin D.

1996-01-01

Rotating electrical contactor capable of carrying 1,000 amperes of current built for use in rotating large workpiece in electroplating bath. Electrical contact made by use of 24 automotive starter motor brushes adapted to match inside diameter of shell electrode.

Trirotron: triode rotating beam radio frequency amplifier

DOEpatents

Lebacqz, Jean V.

1980-01-01

High efficiency amplification of radio frequencies to very high power levels including: establishing a cylindrical cloud of electrons; establishing an electrical field surrounding and coaxial with the electron cloud to bias the electrons to remain in the cloud; establishing a rotating electrical field that surrounds and is coaxial with the steady field, the circular path of the rotating field being one wavelength long, whereby the peak of one phase of the rotating field is used to accelerate electrons in a beam through the bias field in synchronism with the peak of the rotating field so that there is a beam of electrons continuously extracted from the cloud and rotating with the peak; establishing a steady electrical field that surrounds and is coaxial with the rotating field for high-energy radial acceleration of the rotating beam of electrons; and resonating the rotating beam of electrons within a space surrounding the second field, the space being selected to have a phase velocity equal to that of the rotating field to thereby produce a high-power output at the frequency of the rotating field.

A phenomenological treatment of rotating turbulence

NASA Technical Reports Server (NTRS)

Zhou, YE

1995-01-01

The strong similarity between the magnetohydrodynamic (MHD) turbulence and initially isotropic turbulence subject to rotation is noted. We then apply the MHD phenomenologies of Kraichnan and Matthaeus & Zhou to rotating turbulence. When the turbulence is subject to a strong rotation, the energy spectrum is found to scale as E(k) = C(sub Omega)(Omega(sub epsilon))(sup 1/2)k(sup -2), where Omega is the rotation rate, k is the wavenumber, and epsilon is the dissipation rate. This spectral form is consistent with a recent letter by Zeman. However, here the constant C(sub Omega) is found to be related to the Kolmogorov constant and is estimated in the range 1.22 - 1.87 for the typical values of the latter constant. A 'rule' that relates spectral transfer times to the eddy turnover time and the time scale for decay of the triple correlations is deduced. A hypothesis for the triple correlation decay rate leads to the spectral law which varies between the '-5/3' (without rotation) and '-2' laws (with strong rotation). For intermediate rotation rates, the spectrum varies according to the value of a dimensionless parameter that measures the strength of the rotation wavenumber k(sub Omega) = (Omega(sup 3)/epsiolon)(sup 1/2) relative to the wavenumber k. An eddy viscosity is derived with an explicit dependence on the rotation rate.

A Theoretical Model of Jigsaw-Puzzle Pattern Formation by Plant Leaf Epidermal Cells.

PubMed

Higaki, Takumi; Kutsuna, Natsumaro; Akita, Kae; Takigawa-Imamura, Hisako; Yoshimura, Kenji; Miura, Takashi

2016-04-01

Plant leaf epidermal cells exhibit a jigsaw puzzle-like pattern that is generated by interdigitation of the cell wall during leaf development. The contribution of two ROP GTPases, ROP2 and ROP6, to the cytoskeletal dynamics that regulate epidermal cell wall interdigitation has already been examined; however, how interactions between these molecules result in pattern formation remains to be elucidated. Here, we propose a simple interface equation model that incorporates both the cell wall remodeling activity of ROP GTPases and the diffusible signaling molecules by which they are regulated. This model successfully reproduces pattern formation observed in vivo, and explains the counterintuitive experimental results of decreased cellulose production and increased thickness. Our model also reproduces the dynamics of three-way cell wall junctions. Therefore, this model provides a possible mechanism for cell wall interdigitation formation in vivo.

Dynamics and Statistical Mechanics of Rotating and non-Rotating Vortical Flows

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lim, Chjan

Three projects were analyzed with the overall aim of developing a computational/analytical model for estimating values of the energy, angular momentum, enstrophy and total variation of fluid height at phase transitions between disordered and self-organized flow states in planetary atmospheres. It is believed that these transitions in equilibrium statistical mechanics models play a role in the construction of large-scale, stable structures including super-rotation in the Venusian atmosphere and the formation of the Great Red Spot on Jupiter. Exact solutions of the spherical energy-enstrophy models for rotating planetary atmospheres by Kac's method of steepest descent predicted phase transitions to super-rotating solid-bodymore » flows at high energy to enstrophy ratio for all planetary spins and to sub-rotating modes if the planetary spin is large enough. These canonical statistical ensembles are well-defined for the long-range energy interactions that arise from 2D fluid flows on compact oriented manifolds such as the surface of the sphere and torus. This is because in Fourier space available through Hodge theory, the energy terms are exactly diagonalizable and hence has zero range, leading to well-defined heat baths.« less

Effective Rotations: Action Effects Determine the Interplay of Mental and Manual Rotations

ERIC Educational Resources Information Center

Janczyk, Markus; Pfister, Roland; Crognale, Michael A.; Kunde, Wilfried

2012-01-01

The last decades have seen a growing interest in the impact of action on perception and other concurrent cognitive processes. One particularly interesting example is that manual rotation actions facilitate mental rotations in the same direction. The present study extends this research in two fundamental ways. First, Experiment 1 demonstrates that…

Opioid Rotation in Cancer Pain Treatment.

PubMed

Schuster, Michael; Bayer, Oliver; Heid, Florian; Laufenberg-Feldmann, Rita

2018-03-02

Rotating several different WHO level III opioid drugs is a therapeutic option for patients with chronic cancer-related pain who suffer from inadequate analgesia and/or intolerable side effects. The evidence favoring opioid rotation is controversial, and the current guidelines in Germany and other countries contain only weak recommendations for it. This review is based on pertinent publications retrieved by a systematic review of the literature on opioid rotation for adult patients with chronic cancerrelated pain who are regularly taking WHO level III opioids by the oral or trans - dermal route. 9 individual studies involving a total of 725 patients were included in the analysis, and 3 previous systematic reviews of studies involving a total of 2296 patients were also analyzed. Morphine, oxycodone, fentanyl, hydromorphone, and buprenorphine were used as first-line opioid drugs, and hydromorphone, bupre - norphine, tapentadol, fentanyl, morphine, oxymorphone, and methadone were used as second-line opioid drugs. In all of the studies, pain control was achieved for 14 days after each rotation. In most of them, the dose of the new drug introduced in each rotation needed to be increased above the dose initially calculated from a rotation ratio, with the exception of rotations to methadone. The frequency of side effects was only rarely lessened, but patients largely considered the result of opioid rotation to be positive. No particular opioid drug was found to be best. Opioid rotation can improve analgesia and patient satisfaction. The success of opioid rotation appears to depend on the magnitude of the initial dose, among other factors. Tables of equianalgesic doses should be considered no more than a rough guide for determining the dose of the new drug. Rotations to methadone should be carried out under clinical supervision in experienced hands.

Rotating samples in FT-RAMAN spectrometers

NASA Astrophysics Data System (ADS)

De Paepe, A. T. G.; Dyke, J. M.; Hendra, P. J.; Langkilde, F. W.

1997-11-01

It is customary to rotate samples in Raman spectroscopy to avoid absorption or sample heating. In FT-Raman experiments the rotation is always shown (typically 30-60 rpm) because higher speeds are thought to generate noise in the spectra. In this article we show that more rapid rotation is possible. A tablet containing maleic acid and one made up of sub-millimetre silica particles with metoprolol succinate as active ingredient were rotated at different speeds, up to 6760 rpm. The FT-Raman spectra were recorded and studied. We conclude that it is perfectly acceptable to rotate samples up to 1500 rpm.

Studies on dynamic behavior of rotating mirrors

NASA Astrophysics Data System (ADS)

Li, Jingzhen; Sun, Fengshan; Gong, Xiangdong; Huang, Hongbin; Tian, Jie

2005-02-01

A rotating mirror is a kernel unit in a Miller-type high speed camera, which is both as an imaging element in optical path and as an element to implement ultrahigh speed photography. According to Schardin"s Principle, information capacity of an ultrahigh speed camera with rotating mirror depends on primary wavelength of lighting used by the camera and limit linear velocity on edge of the rotating-mirror: the latter is related to material (including specifications in technology), cross-section shape and lateral structure of rotating mirror. In this manuscript dynamic behavior of high strength aluminium alloy rotating mirrors is studied, from which it is preliminarily shown that an aluminium alloy rotating mirror can be absolutely used as replacement for a steel rotating-mirror or a titanium alloy rotating-mirror in framing photographic systems, and it could be also used as a substitute for a beryllium rotating-mirror in streak photographic systems.

In-line rotating capacitive torque sensor

DOEpatents

Kronberg, J.W.

1991-09-10

Disclosed are a method and apparatus for measuring torques developed along a rotating mechanical assembly comprising a rotating inner portion and a stationary outer portion. The rotating portion has an electrically-conductive flexing section fitted between two coaxial shafts in a configuration which varies radially in accordance with applied torque. The stationary portion comprises a plurality of conductive plates forming a surface concentric with and having a diameter slightly larger than the diameter of the rotating portion. The capacitance between the outer, nonrotating and inner, rotating portion varies with changes in the radial configuration of the rotating portion. Signal output varies approximately linearly with torque for small torques, nonlinearly for larger torques. The sensor is preferably surrounded by a conductive shell to minimize electrical interference from external sources. 18 figures.

Femoral component rotation in patellofemoral joint replacement.

PubMed

van Jonbergen, Hans-Peter W; Westerbeek, Robin E

2018-06-01

Clinical outcomes in patellofemoral joint replacement may be related to femoral component rotation. Assessment of rotational alignment is however difficult as patients with isolated patellofemoral osteoarthritis often have trochlear dysplasia. The use of the medial malleolus as a landmark to guide rotation has been suggested. The purpose of our study was to evaluate this technique with regard to femoral component rotation, and to correlate rotation with clinical outcomes at one-year follow-up. Forty-one knees in 39 patients had patellofemoral joint replacement using the Zimmer Gender-Solutions patellofemoral prosthesis. Intraoperatively, we determined femoral component rotational alignment using an extramedullary rod aimed at the inferior tip of the medial malleolus. Postoperatively, we measured the angle between the femoral component and the anatomical transepicondylar axis using CT. The amount of rotation was correlated with clinical outcomes at one-year follow-up. Forty knees in 38 patients were available for one-year follow-up. Mean femoral component rotation relative to the anatomical transepicondylar axis was 1.4° external rotation (range, -3.8 to 5.7°). We found no statistically significant correlation between femoral component rotation and change from baseline KOOS subscales at one-year follow-up. Our findings show that when using the medial malleolus as a landmark to guide rotation, the femoral component of the patellofemoral prosthesis was oriented in external rotation relative to the anatomical transepicondylar axis in 80% of knees. Our study did not show a relation between the amount of external rotation and clinical outcomes. Level III. Copyright © 2018 Elsevier B.V. All rights reserved.

Current status of rotational atherectomy.

PubMed

Tomey, Matthew I; Kini, Annapoorna S; Sharma, Samin K

2014-04-01

Rotational atherectomy facilitates percutaneous coronary intervention for complex de novo lesions with severe calcification. A strategy of routine rotational atherectomy has not, however, conferred reduction in restenosis or major adverse cardiac events. As it is technically demanding, rotational atherectomy is also uncommon. At this 25-year anniversary since the introduction of rotational atherectomy, we sought to review the current state-of-the-art in rotational atherectomy technique, safety, and efficacy data in the modern era of drug-eluting stents, strategies to prevent and manage complications, including slow-flow/no-reflow and burr entrapment, and appropriate use in the context of the broader evolution in the management of stable ischemic heart disease. Fundamental elements of optimal technique include use of a single burr with burr-to-artery ratio of 0.5 to 0.6-rotational speed of 140,000 to 150,000 rpm, gradual burr advancement using a pecking motion, short ablation runs of 15 to 20 s, and avoidance of decelerations >5,000 rpm. Combined with meticulous technique, optimal antiplatelet therapy, vasodilators, flush solution, and provisional use of atropine, temporary pacing, vasopressors, and mechanical support may prevent slow-flow/no-reflow, which in contemporary series is reported in 0.0% to 2.6% of cases. On the basis of the results of recent large clinical trials, a subset of patients with complex coronary artery disease previously assigned to rotational atherectomy may be directed instead to medical therapy alone or bypass surgery. For patients with de novo severely calcified lesions for which rotational atherectomy remains appropriate, referral centers of excellence are required. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Rotational joint assembly and method for constructing the same

NASA Technical Reports Server (NTRS)

Bandera, Pablo (Inventor); Buchele, Paul (Inventor)

2012-01-01

A rotational joint assembly and a method for constructing a rotational joint assembly are provided. The rotational joint assembly includes a first rotational component, a second rotational component coupled to the first rotational component such that the second rotational component is rotatable relative to the first rotational component in first and second rotational directions about an axis, and a flexure member, being deflectable in first and second deflection directions, coupled to at least one of the first and second rotational components such that when the second rotational component is rotated relative to the first rotational component in each of the first and second rotational directions about the axis, the flexure member is deflected in the first deflection direction and exerts a force on the second rotational component opposing the rotation.

The puzzling Venusian polar atmospheric structure reproduced by a general circulation model

PubMed Central

Ando, Hiroki; Sugimoto, Norihiko; Takagi, Masahiro; Kashimura, Hiroki; Imamura, Takeshi; Matsuda, Yoshihisa

2016-01-01

Unlike the polar vortices observed in the Earth, Mars and Titan atmospheres, the observed Venus polar vortex is warmer than the midlatitudes at cloud-top levels (∼65 km). This warm polar vortex is zonally surrounded by a cold latitude band located at ∼60° latitude, which is a unique feature called ‘cold collar' in the Venus atmosphere. Although these structures have been observed in numerous previous observations, the formation mechanism is still unknown. Here we perform numerical simulations of the Venus atmospheric circulation using a general circulation model, and succeed in reproducing these puzzling features in close agreement with the observations. The cold collar and warm polar region are attributed to the residual mean meridional circulation enhanced by the thermal tide. The present results strongly suggest that the thermal tide is crucial for the structure of the Venus upper polar atmosphere at and above cloud levels. PMID:26832195

Advances in Rotational Seismic Measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pierson, Robert; Laughlin, Darren; Brune, Robert

2016-10-19

Rotational motion is increasingly understood to be a significant part of seismic wave motion. Rotations can be important in earthquake strong motion and in Induced Seismicity Monitoring. Rotational seismic data can also enable shear selectivity and improve wavefield sampling for vertical geophones in 3D surveys, among other applications. However, sensor technology has been a limiting factor to date. The US Department of Energy (DOE) and Applied Technology Associates (ATA) are funding a multi-year project that is now entering Phase 2 to develop and deploy a new generation of rotational sensors for validation of rotational seismic applications. Initial focus is onmore » induced seismicity monitoring, particularly for Enhanced Geothermal Systems (EGS) with fracturing. The sensors employ Magnetohydrodynamic (MHD) principles with broadband response, improved noise floors, robustness, and repeatability. This paper presents a summary of Phase 1 results and Phase 2 status.« less

Synchronization in counter-rotating oscillators.

PubMed

Bhowmick, Sourav K; Ghosh, Dibakar; Dana, Syamal K

2011-09-01

An oscillatory system can have opposite senses of rotation, clockwise or anticlockwise. We present a general mathematical description of how to obtain counter-rotating oscillators from the definition of a dynamical system. A type of mixed synchronization emerges in counter-rotating oscillators under diffusive scalar coupling when complete synchronization and antisynchronization coexist in different state variables. We present numerical examples of limit cycle van der Pol oscillator and chaotic Rössler and Lorenz systems. Stability conditions of mixed synchronization are analytically obtained for both Rössler and Lorenz systems. Experimental evidences of counter-rotating limit cycle and chaotic oscillators and mixed synchronization are given in electronic circuits.

High performance rotational vibration isolator

NASA Astrophysics Data System (ADS)

Sunderland, Andrew; Blair, David G.; Ju, Li; Golden, Howard; Torres, Francis; Chen, Xu; Lockwood, Ray; Wolfgram, Peter

2013-10-01

We present a new rotational vibration isolator with an extremely low resonant frequency of 0.055 ± 0.002 Hz. The isolator consists of two concentric spheres separated by a layer of water and joined by very soft silicone springs. The isolator reduces rotation noise at all frequencies above its resonance which is very important for airborne mineral detection. We show that more than 40 dB of isolation is achieved in a helicopter survey for rotations at frequencies between 2 Hz and 20 Hz. Issues affecting performance such as translation to rotation coupling and temperature are discussed. The isolator contains almost no metal, making it particularly suitable for electromagnetic sensors.

High performance rotational vibration isolator.

PubMed

Sunderland, Andrew; Blair, David G; Ju, Li; Golden, Howard; Torres, Francis; Chen, Xu; Lockwood, Ray; Wolfgram, Peter

2013-10-01

We present a new rotational vibration isolator with an extremely low resonant frequency of 0.055 ± 0.002 Hz. The isolator consists of two concentric spheres separated by a layer of water and joined by very soft silicone springs. The isolator reduces rotation noise at all frequencies above its resonance which is very important for airborne mineral detection. We show that more than 40 dB of isolation is achieved in a helicopter survey for rotations at frequencies between 2 Hz and 20 Hz. Issues affecting performance such as translation to rotation coupling and temperature are discussed. The isolator contains almost no metal, making it particularly suitable for electromagnetic sensors.

Turbulent Compressible Convection with Rotation. 2; Mean Flows and Differential Rotation

NASA Technical Reports Server (NTRS)

Brummell, Nicholas H.; Hurlburt, Neal E.; Toomre, Juri

1998-01-01

The effects of rotation on turbulent, compressible convection within stellar envelopes are studied through three-dimensional numerical simulations conducted within a local f-plane model. This work seeks to understand the types of differential rotation that can be established in convective envelopes of stars like the Sun, for which recent helioseismic observations suggest an angular velocity profile with depth and latitude at variance with many theoretical predictions. This paper analyzes the mechanisms that are responsible for the mean (horizontally averaged) zonal and meridional flows that are produced by convection influenced by Coriolis forces. The compressible convection is considered for a range of Rayleigh, Taylor, and Prandtl (and thus Rossby) numbers encompassing both laminar and turbulent flow conditions under weak and strong rotational constraints. When the nonlinearities are moderate, the effects of rotation on the resulting laminar cellular convection leads to distinctive tilts of the cell boundaries away from the vertical. These yield correlations between vertical and horizontal motions that generate Reynolds stresses that can drive mean flows, interpretable as differential rotation and meridional circulations. Under more vigorous forcing, the resulting turbulent convection involves complicated and contorted fluid particle trajectories, with few clear correlations between vertical and horizontal motions, punctuated by an evolving and intricate downflow network that can extend over much of the depth of the layer. Within such networks are some coherent structures of vortical downflow that tend to align with the rotation axis. These yield a novel turbulent alignment mechanism, distinct from the laminar tilting of cellular boundaries, that can provide the principal correlated motions and thus Reynolds stresses and subsequently mean flows. The emergence of such coherent structures that can persist amidst more random motions is a characteristic of turbulence

Rotational movements of mandibular two-implant overdentures.

PubMed

Kimoto, Suguru; Pan, Shaoxia; Drolet, Nicolas; Feine, Jocelyne S

2009-08-01

Clinicians have reported that their patients complain that their mandibular two-implant overdentures (IOD) rotate. Therefore, we studied the frequency and severity of rotation of IODs with two-ball attachments, how rotation may influence perceived satisfaction ratings of chewing ability, and the factors that are involved in the rotation of IODs. Seventy-nine participants were recruited and asked to rate their general satisfaction of their IODs, as well as their ability to chew foods, the existence of any mandibular denture rotation, and to what degree denture rotation bothered them. Data on participant sociodemographic, anatomical, and prosthesis characteristics were also collected. Student's t-test and logistic regression analyses were performed to analyze the differences between participants who did (R group) and did not report (NR group) denture rotation. Thirty-seven of 79 participants were aware of rotational movement in their IODs. These patients were significantly less satisfied with their chewing ability than those who felt no rotation (69.1 mm R group vs. 82.9 mm), and discomfort caused by the rotation bothered them moderately (39/100 mm). The multivariate logistic regression analysis revealed that the arrangement of the anterior teeth and the length of the denture are significantly associated with awareness of denture rotation. Thirty-eight percent in the R group and 31% in the NR group had non-scheduled visits. Rotational movement with a mandibular two-IOD has a negative effect on perceived chewing ability and is associated with anterior tooth arrangement and denture length.

Viscoelastic flow in rotating curved pipes

NASA Astrophysics Data System (ADS)

Chen, Yitung; Chen, Huajun; Zhang, Jinsuo; Zhang, Benzhao

2006-08-01

Fully developed viscoelastic flows in rotating curved pipes with circular cross section are investigated theoretically and numerically employing the Oldroyd-B fluid model. Based on Dean's approximation, a perturbation solution up to the secondary order is obtained. The governing equations are also solved numerically by the finite volume method. The theoretical and numerical solutions agree with each other very well. The results indicate that the rotation, as well as the curvature and elasticity, plays an important role in affecting the friction factor, the secondary flow pattern and intensity. The co-rotation enhances effects of curvature and elasticity on the secondary flow. For the counter-rotation, there is a critical rotational number RΩ', which can make the effect of rotation counteract the effect of curvature and elasticity. Complicated flow behaviors are found at this value. For the relative creeping flow, RΩ' can be estimated according to the expression RΩ'=-4Weδ. Effects of curvature and elasticity at different rotational numbers on both relative creeping flow and inertial flow are also analyzed and discussed.

Practising Mental Rotation Using Interactive Desktop Mental Rotation Trainer (iDeMRT)

ERIC Educational Resources Information Center

Rafi, Ahmad; Samsudin, Khairulanuar

2009-01-01

An experimental study involving 30 undergraduates (mean age = 20.5 years) in mental rotation (MR) training was conducted in an interactive Desktop Mental Rotation Trainer (iDeMRT). Stratified random sampling assigned students into one experimental group and one control group. The former trained in iDeMRT and the latter trained in conventional…

Flow past a rotating cylinder

NASA Astrophysics Data System (ADS)

Mittal, Sanjay; Kumar, Bhaskar

2003-02-01

Flow past a spinning circular cylinder placed in a uniform stream is investigated via two-dimensional computations. A stabilized finite element method is utilized to solve the incompressible Navier Stokes equations in the primitive variables formulation. The Reynolds number based on the cylinder diameter and free-stream speed of the flow is 200. The non-dimensional rotation rate, [alpha] (ratio of the surface speed and freestream speed), is varied between 0 and 5. The time integration of the flow equations is carried out for very large dimensionless time. Vortex shedding is observed for [alpha] < 1.91. For higher rotation rates the flow achieves a steady state except for 4.34 < [alpha] < 4:70 where the flow is unstable again. In the second region of instability, only one-sided vortex shedding takes place. To ascertain the instability of flow as a function of [alpha] a stabilized finite element formulation is proposed to carry out a global, non-parallel stability analysis of the two-dimensional steady-state flow for small disturbances. The formulation and its implementation are validated by predicting the Hopf bifurcation for flow past a non-rotating cylinder. The results from the stability analysis for the rotating cylinder are in very good agreement with those from direct numerical simulations. For large rotation rates, very large lift coefficients can be obtained via the Magnus effect. However, the power requirement for rotating the cylinder increases rapidly with rotation rate.

IO Rotation Movie

NASA Technical Reports Server (NTRS)

2000-01-01

During its 1979 flyby, Voyager 2 observed Io only from a distance. However, the volcanic activity discovered by Voyager 1 months earlier was readily visible. This sequence of nine color images was collected using the Blue, Green and Orange filters from about 1.2 million kilometers. A 2.5 hour period is covered during which Io rotates 7 degrees.

Rotating into view over the limb of Io are the plumes of the volcanoes Amirani (top) and Maui (lower). These plumes are very distinct against the black sky because they are being illuminated from behind. Notice that as Io rotates, the proportion of Io which is sunlit decreases greatly. This changing phase angle is because Io is moving between the spacecraft and the Sun.

This time-lapse movie was produced at JPL by the Image Processing Laboratory in 1985.

Rotational rate sensor

DOEpatents

Hunter, Steven L.

2002-01-01

A rate sensor for angular/rotational acceleration includes a housing defining a fluid cavity essentially completely filled with an electrolyte fluid. Within the housing, such as a toroid, ions in the fluid are swept during movement from an excitation electrode toward one of two output electrodes to provide a signal for directional rotation. One or more ground electrodes within the housing serve to neutralize ions, thus preventing any effect at the other output electrode.

An all-reflective polarization rotator

NASA Astrophysics Data System (ADS)

Bohus, J.; Budai, Judit; Kalashnikov, M.; Osvay, K.

2017-05-01

The conceptual design and proof of principle experimental results of a polarization rotator based on mirrors are presented. The device is suitable for any-angle, online rotation of the plane of polarization of high peak intensity ultrashort laser pulses. Controllable rotation of the polarization vector of short laser pulses with a broad bandwidth requires achromatic retarding plates which have a limited scalability and the substantial plate thickness can lead to pulse broadening and inaccurate polarization rotation. Polarization rotators based on reflective optical elements are preferable alternatives to wave plates especially when used in high average power or high peak intensity ultra-short laser systems. The control of the polarization state is desirable in many laser-matter interaction experiments e.g., high harmonic and attosecond pulse generation, electron, proton and ion acceleration, electron-positron pair creating, vacuum nonlinear polarization effect. The device can also serve as a beam attenuator, in combination with a linear polarizer.

Rotatable seal assembly. [Patent application; rotating targets

DOEpatents

Logan, C.M.; Garibaldi, J.L.

1980-11-12

An assembly is provided for rotatably supporting a rotor on a stator so that vacuum chambers in the rotor and stator remain in communication while the chambers are sealed from ambient air, which enables the use of a ball bearing or the like to support most of the weight of the rotor. The apparatus includes a seal device mounted on the rotor to rotate therewith, but shiftable in position on the rotor while being sealed to the rotor as by an O-ring. The seal device has a flat face that is biased towards a flat face on the stator, and pressurized air is pumped between the faces to prevent contact between them while spacing them a small distance apart to avoid the inflow of large amounts of air between the faces and into the vacuum chambers.

Rotating Detonation Engine Operation (Preprint)

DTIC Science & Technology

2012-01-01

MdotH2 = mass flow of hydrogen MdotAir = mass flow of air PCB = Piezoelectric Pressure Sensor PDE = Pulsed Detonation Engine RDE = Rotating ...and unsteady thrust output of PDEs . One of the new designs was the Rotating Detonation Engine (RDE). An RDE operates by exhausting an initial...AFRL-RZ-WP-TP-2012-0003 ROTATING DETONATION ENGINE OPERATION (PREPRINT) James A. Suchocki and Sheng-Tao John Yu The Ohio State

Non-classical continuum theory for solids incorporating internal rotations and rotations of Cosserat theories

NASA Astrophysics Data System (ADS)

Surana, K. S.; Joy, A. D.; Reddy, J. N.

2017-03-01

This paper presents a non-classical continuum theory in Lagrangian description for solids in which the conservation and the balance laws are derived by incorporating both the internal rotations arising from the Jacobian of deformation and the rotations of Cosserat theories at a material point. In particular, in this non-classical continuum theory, we have (i) the usual displacements ( ±b \\varvec{u}) and (ii) three internal rotations ({}_i ±b \\varvec{Θ}) about the axes of a triad whose axes are parallel to the x-frame arising from the Jacobian of deformation (which are completely defined by the skew-symmetric part of the Jacobian of deformation), and (iii) three additional rotations ({}_e ±b \\varvec{Θ}) about the axes of the same triad located at each material point as additional three degrees of freedom referred to as Cosserat rotations. This gives rise to ±b \\varvec{u} and {}_e ±b \\varvec{{Θ} as six degrees of freedom at a material point. The internal rotations ({}_i ±b \\varvec{Θ}), often neglected in classical continuum mechanics, exist in all deforming solid continua as these are due to Jacobian of deformation. When the internal rotations {}_i ±b \\varvec{Θ} are resisted by the deforming matter, conjugate moment tensor arises that together with {}_i ±b \\varvec{Θ} may result in energy storage and/or dissipation, which must be accounted for in the conservation and the balance laws. The Cosserat rotations {}_e ±b \\varvec{Θ} also result in conjugate moment tensor which, together with {}_e ±b \\varvec{Θ}, may also result in energy storage and/or dissipation. The main focus of the paper is a consistent derivation of conservation and balance laws that incorporate aforementioned physics and associated constitutive theories for thermoelastic solids. The mathematical model derived here has closure, and the constitutive theories derived using two alternate approaches are in agreement with each other as well as with the condition resulting from the

Rotation of Giant Stars

NASA Astrophysics Data System (ADS)

Kissin, Yevgeni; Thompson, Christopher

2015-07-01

The internal rotation of post-main sequence stars is investigated, in response to the convective pumping of angular momentum toward the stellar core, combined with a tight magnetic coupling between core and envelope. The spin evolution is calculated using model stars of initial mass 1, 1.5, and 5 {M}⊙ , taking into account mass loss on the giant branches. We also include the deposition of orbital angular momentum from a sub-stellar companion, as influenced by tidal drag along with the excitation of orbital eccentricity by a fluctuating gravitational quadrupole moment. A range of angular velocity profiles {{Ω }}(r) is considered in the envelope, extending from solid rotation to constant specific angular momentum. We focus on the backreaction of the Coriolis force, and the threshold for dynamo action in the inner envelope. Quantitative agreement with measurements of core rotation in subgiants and post-He core flash stars by Kepler is obtained with a two-layer angular velocity profile: uniform specific angular momentum where the Coriolis parameter {Co}\\equiv {{Ω }}{τ }{con}≲ 1 (here {τ }{con} is the convective time), and {{Ω }}(r)\\propto {r}-1 where {Co}≳ 1. The inner profile is interpreted in terms of a balance between the Coriolis force and angular pressure gradients driven by radially extended convective plumes. Inward angular momentum pumping reduces the surface rotation of subgiants, and the need for a rejuvenated magnetic wind torque. The co-evolution of internal magnetic fields and rotation is considered in Kissin & Thompson, along with the breaking of the rotational coupling between core and envelope due to heavy mass loss.

Recognition of rotated images using the multi-valued neuron and rotation-invariant 2D Fourier descriptors

NASA Astrophysics Data System (ADS)

Aizenberg, Evgeni; Bigio, Irving J.; Rodriguez-Diaz, Eladio

2012-03-01

The Fourier descriptors paradigm is a well-established approach for affine-invariant characterization of shape contours. In the work presented here, we extend this method to images, and obtain a 2D Fourier representation that is invariant to image rotation. The proposed technique retains phase uniqueness, and therefore structural image information is not lost. Rotation-invariant phase coefficients were used to train a single multi-valued neuron (MVN) to recognize satellite and human face images rotated by a wide range of angles. Experiments yielded 100% and 96.43% classification rate for each data set, respectively. Recognition performance was additionally evaluated under effects of lossy JPEG compression and additive Gaussian noise. Preliminary results show that the derived rotation-invariant features combined with the MVN provide a promising scheme for efficient recognition of rotated images.

14 CFR 33.74 - Continued rotation.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.74 Continued rotation. If any of the engine main rotating systems continue to rotate after the engine is shutdown for any reason...

14 CFR 33.74 - Continued rotation.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.74 Continued rotation. If any of the engine main rotating systems continue to rotate after the engine is shutdown for any reason...

Rotator cuff injuries.

PubMed

Crusher, R H

2000-07-01

Different types of rotator cuff injuries frequently present to Accident and Emergency departments and minor injury units but can be difficult to differentiate clinically. This brief case study describes the examination and diagnosis of related shoulder injuries, specifically rotator cuff tears/disruption and calcifying supraspinatus tendinitis. The relevant anatomy and current therapies for these injuries is also discussed to enable the emergency nurse practitioner to have a greater understanding of the theory surrounding their diagnosis and treatments.

Rehabilitation after Rotator Cuff Repair.

PubMed

Nikolaidou, Ourania; Migkou, Stefania; Karampalis, Christos

2017-01-01

Rotator cuff tears are a very common condition that is often incapacitating. Whether non-surgical or surgical, successful management of rotator cuff disease is dependent on appropriate rehabilitation. If conservative management is insufficient, surgical repair is often indicated. Postsurgical outcomes for patients having had rotator cuff repair can be quite good. A successful outcome is much dependent on surgical technique as it is on rehabilitation. Numerous rehabilitation protocols for the management of rotator cuff disease are based primarily on clinical experience and expert opinion. This article describes the different rehabilitation protocols that aim to protect the repair in the immediate postoperative period, minimize postoperative stiffness and muscle atrophy. A review of currently available literature on rehabilitation after arthroscopic rotator cuff tear repair was performed to illustrate the available evidence behind various postoperative treatment modalities. There were no statistically significant differences between a conservative and an accelerated rehabilitation protocol . Early passive range of motion (ROM) following arthroscopic cuff repair is thought to decrease postoperative stiffness and improve functionality. However, early aggressive rehabilitation may compromise repair integrity. The currently available literature did not identify any significant differences in functional outcomes and relative risks of re-tears between delayed and early motion in patients undergoing arthroscopic rotator cuff repairs. A gentle rehabilitation protocol with limits in range of motion and exercise times after arthroscopic rotator cuff repair would be better for tendon healing without taking any substantial risks. A close communication between the surgeon, the patient and the physical therapy team is important and should continue throughout the whole recovery process.

Gravity controlled anti-reverse rotation device

DOEpatents

Dickinson, Robert J.; Wetherill, Todd M.

1983-01-01

A gravity assisted anti-reverse rotation device for preventing reverse rotation of pumps and the like. A horizontally mounted pawl is disposed to mesh with a fixed ratchet preventing reverse rotation when the pawl is advanced into intercourse with the ratchet by a vertically mounted lever having a lumped mass. Gravitation action on the lumped mass urges the pawl into mesh with the ratchet, while centrifugal force on the lumped mass during forward, allowed rotation retracts the pawl away from the ratchet.

From near to eternity: Spin-glass planting, tiling puzzles, and constraint-satisfaction problems

NASA Astrophysics Data System (ADS)

Hamze, Firas; Jacob, Darryl C.; Ochoa, Andrew J.; Perera, Dilina; Wang, Wenlong; Katzgraber, Helmut G.

2018-04-01

We present a methodology for generating Ising Hamiltonians of tunable complexity and with a priori known ground states based on a decomposition of the model graph into edge-disjoint subgraphs. The idea is illustrated with a spin-glass model defined on a cubic lattice, where subproblems, whose couplers are restricted to the two values {-1 ,+1 } , are specified on unit cubes and are parametrized by their local degeneracy. The construction is shown to be equivalent to a type of three-dimensional constraint-satisfaction problem known as the tiling puzzle. By varying the proportions of subproblem types, the Hamiltonian can span a dramatic range of typical computational complexity, from fairly easy to many orders of magnitude more difficult than prototypical bimodal and Gaussian spin glasses in three space dimensions. We corroborate this behavior via experiments with different algorithms and discuss generalizations and extensions to different types of graphs.

Construction and laboratory test of the fiber optic rotational seismograph FOSREM for rotational seismology area of interest

NASA Astrophysics Data System (ADS)

Kurzych, Anna; Jaroszewicz, Leszek R.; Kowalski, Jerzy K.

2017-05-01

A relatively young field of study named Rotational Seismology caused a highly interest in an investigation of rotational movements generated by earthquakes, explosions, and ambient vibrations. It includes a wide range of scientific branches. However, this field needs to apply appropriate rotational sensors which should fulfill restrict technical requirements. The presented in this work system FOSREM (Fibre-Optic System for Rotational Events and Phenomena Monitoring) seems to be a promising rotational sensor for such investigation. FOSREM works by measuring the Sagnac effect and generally consists of two basic elements: optical sensor and electronic part. Regarding to its theoretical sensitivity equals 2·10-8 rad/s/Hz1/2, it enables to measure rotation in a wide range of signal amplitude (10-8 rad/s ÷ 10 rad/s) and frequency (DC ÷ 328.12 Hz). Moreover, FOSREM is mobile and remotely controlled via Internet using a special designed software.

Modal testing of a rotating wind turbine

NASA Astrophysics Data System (ADS)

Carne, T. G.; Nord, A. R.

1982-11-01

A testing technique was developed to measure the modes of vibration of a rotating vertical-axis wind turbine. This technique was applied to the Sandia Two-Meter Turbine, where the changes in individual modal frequencies as a function of the rotational speed were tracked from 0 rpm (parked) to 600 rpm. During rotational testing, the structural response was measured using a combination of strain gages and accelerometers, passing the signals through slip rings. Excitation of the turbine structure was provided by a scheme which suddenly released a pretensioned cable, thus plucking the turbine as it was rotating at a set speed. In addition to calculating the real modes of the parked turbine, the modes of the rotating turbine were also determined at several rotational speeds. The modes of the rotating system proved to be complex due to centrifugal and Coriolis effects. The modal data for the parked turbine were used to update a finite-element model. Also, the measured modal parameters for the rotating turbine were compared to the analytical results, thus verifying the analytical procedures used to incorporate the effects of the rotating coordinate system.

Hip Rotation Range of Motion in People With and Without Low Back Pain Who Participate in Rotation-Related Sports

PubMed Central

Van Dillen, Linda R.; Bloom, Nancy J.; Gombatto, Sara P.; Susco, Thomas M.

2008-01-01

Objective To examine whether passive hip rotation motion was different between people with and without low back pain (LBP) who regularly participate in sports that require repeated rotation of the trunk and hips. We hypothesized that people with LBP would have less total hip rotation motion and more asymmetry of motion between sides than people without LBP. Design Two group, case-control. Setting University-based musculoskeletal analysis laboratory. Participants Forty-eight subjects (35 males, 13 females; mean age: 26.56±7.44 years) who reported regular participation in a rotation-related sport participated. Two groups were compared; people with LBP (N=24) and people without LBP (N=24; NoLBP). Main outcome measures Data were collected on participant-related, LBP-related, sport-related and activity-related variables. Measures of passive hip rotation range of motion were obtained. The differences between the LBP and NoLBP groups were examined. Results People with and without a history of LBP were the same with regard to all participant-related, sport-related and activity-related variables. The LBP group had significantly less total rotation (P=.035) and more asymmetry of total rotation, right hip versus left hip, (P=.022) than the NoLBP group. Left total hip rotation was more limited than right total hip rotation in the LBP group (P=.004). There were no significant differences in left and right total hip rotation for the NoLBP group (P=.323). Conclusions Among people who participate in rotation-related sports, those with LBP had less overall passive hip rotation motion and more asymmetry of rotation between sides than people without LBP. These findings suggest that the specific directional demands imposed on the hip and trunk during regularly performed activities may be an important consideration in deciding which impairments may be most relevant to test and to consider in prevention and intervention strategies. PMID:19081817

Holographic flow visualization in rotating turbomachinery

NASA Astrophysics Data System (ADS)

Parker, R. J.; Reeves, M.

1990-11-01

Holographic flow visualization has found many applications in rotating turbomachinery. Applications in the design of aeroengine fans, automotive turbochargers, turbines, helicopter rotors, and advanced propfans are discussed. Work in ducted rotating flows and rotating free aerofoils is brought together and new developments in each field are revealed.

Polygons on a rotating fluid surface.

PubMed

Jansson, Thomas R N; Haspang, Martin P; Jensen, Kåre H; Hersen, Pascal; Bohr, Tomas

2006-05-05

We report a novel and spectacular instability of a fluid surface in a rotating system. In a flow driven by rotating the bottom plate of a partially filled, stationary cylindrical container, the shape of the free surface can spontaneously break the axial symmetry and assume the form of a polygon rotating rigidly with a speed different from that of the plate. With water, we have observed polygons with up to 6 corners. It has been known for many years that such flows are prone to symmetry breaking, but apparently the polygonal surface shapes have never been observed. The creation of rotating internal waves in a similar setup was observed for much lower rotation rates, where the free surface remains essentially flat [J. M. Lopez, J. Fluid Mech. 502, 99 (2004). We speculate that the instability is caused by the strong azimuthal shear due to the stationary walls and that it is triggered by minute wobbling of the rotating plate.

Job rotation in nursing: a study of job rotation among nursing personnel from the literature and via a questionnaire.

PubMed

Järvi, Maija; Uusitalo, Tarja

2004-09-01

To obtain information on job rotation among nursing personnel from the literature and via a questionnaire. A nursing career no longer means a series of steps leading up a hierarchy. It has become more like a process of individual growth, involving improvement of employee expertise and skills. Job rotation in connection with career development in a Finnish hospital is considered essential, and participating in job rotation is one requirement for newly vacant nursing posts. Describing job rotation by means of reference to literature, and studying a survey on attitudes of ophthalmic nurses (n = 84) to job rotation. There has been little theoretical or empirical research on job rotation. In this study, one in three had participated in job rotation that was most often considered a positive experience. Self-development was rated substantially useful, but fewer were interested in participating in various kinds of developmental activities. Employee's motivation is the foundation of successful development activity, e.g. job rotation.

Rotating Apparatus for Isoelectric Focusing

NASA Technical Reports Server (NTRS)

Bier, M.

1986-01-01

Remixing of separated fractions prevented. Improved isoelectric focusing apparatus helps to prevent electro-osmosis and convection, both of which cause remixing of separated fractions. Fractionating column segmented and rotated about horizontal axis: Only combined effects of both features fully effective in making good separations. Improved apparatus slowly rotated continuously or rocked (at rotational amplitude of at least 180 degrees) about its horizontal axis so average gravitational vector experienced by fluid is zero and convection is therefore suppressed. Electro-osmosis suppressed and convection further suppressed by separating column into disklike compartments along its length with filters. Experiments have shown dimensions of apparatus not critical. Typical compartment and column volumes are 2 and 40 ml, respectively. Rotation speeds lie between 3 and 30 rpm.

Rotational Seismology: AGU Session, Working Group, and Website

USGS Publications Warehouse

Lee, William H.K.; Igel, Heiner; Todorovska, Maria I.; Evans, John R.

2007-01-01

Introduction Although effects of rotational motions due to earthquakes have long been observed (e. g., Mallet, 1862), nevertheless Richter (1958, p. 213) stated that: 'Perfectly general motion would also involve rotations about three perpendicular axes, and three more instruments for these. Theory indicates, and observation confirms, that such rotations are negligible.' However, Richter provided no references for this claim. Seismology is based primarily on the observation and modeling of three-component translational ground motions. Nevertheless, theoretical seismologists (e.g., Aki and Richards, 1980, 2002) have argued for decades that the rotational part of ground motions should also be recorded. It is well known that standard seismometers are quite sensitive to rotations and therefore subject to rotation-induced errors. The paucity of observations of rotational motions is mainly the result of a lack, until recently, of affordable rotational sensors of sufficient resolution. Nevertheless, in the past decade, a number of authors have reported direct observations of rotational motions and rotations inferred from rigid-body rotations in short baseline accelerometer arrays, creating a burgeoning library of rotational data. For example, ring laser gyros in Germany and New Zealand have led to the first significant and consistent observations of rotational motions from distant earthquakes (Igel et al., 2005, 2007). A monograph on Earthquake Source Asymmetry, Structural Media and Rotation Effects was published recently as well by Teisseyre et al. (2006). Measurement of rotational motions has implications for: (1) recovering the complete ground-displacement history from seismometer recordings; (2) further constraining earthquake rupture properties; (3) extracting information about subsurface properties; and (4) providing additional ground motion information to earthquake engineers for seismic design. A special session on Rotational Motions in Seismology was convened by H

Space station rotational equations of motion

NASA Technical Reports Server (NTRS)

Rheinfurth, M. H.; Carroll, S. N.

1985-01-01

Dynamic equations of motion are developed which describe the rotational motion for a large space structure having rotating appendages. The presence of the appendages produce torque coupling terms which are dependent on the inertia properties of the appendages and the rotational rates for both the space structure and the appendages. These equations were formulated to incorporate into the Space Station Attitude Control and Stabilization Test Bed to accurately describe the influence rotating solar arrays and thermal radiators have on the dynamic behavior of the Space Station.

Sex Differences in Mental Rotation Tasks: Not Just in the Mental Rotation Process!

ERIC Educational Resources Information Center

Boone, Alexander P.; Hegarty, Mary

2017-01-01

The paper-and-pencil Mental Rotation Test (Vandenberg & Kuse, 1978) consistently produces large sex differences favoring men (Voyer, Voyer, & Bryden, 1995). In this task, participants select 2 of 4 answer choices that are rotations of a probe stimulus. Incorrect choices (i.e., foils) are either mirror reflections of the probe or…

Physics of rotation: problems and challenges

NASA Astrophysics Data System (ADS)

Maeder, Andre; Meynet, Georges

2015-01-01

We examine some debated points in current discussions about rotating stars: the shape, the gravity darkening, the critical velocities, the mass loss rates, the hydrodynamical instabilities, the internal mixing and N-enrichments. The study of rotational mixing requires high quality data and careful analysis. From recent studies where such conditions are fulfilled, rotational mixing is well confirmed. Magnetic coupling with stellar winds may produce an apparent contradiction, i.e. stars with a low rotation and a high N-enrichment. We point out that it rather confirms the large role of shears in differentially rotating stars for the transport processes. New models of interacting binaries also show how shears and mixing may be enhanced in close binaries which are either spun up or down by tidal interactions.

Modeling human vestibular responses during eccentric rotation and off vertical axis rotation

NASA Technical Reports Server (NTRS)

Merfeld, D. M.; Paloski, W. H. (Principal Investigator)

1995-01-01

A mathematical model has been developed to help explain human multi-sensory interactions. The most important constituent of the model is the hypothesis that the nervous system incorporates knowledge of sensory dynamics into an "internal model" of these dynamics. This internal model allows the nervous system to integrate the sensory information from many different sensors into a coherent estimate of self-motion. The essence of the model is unchanged from a previously published model of monkey eye movement responses; only a few variables have been adjusted to yield the prediction of human responses. During eccentric rotation, the model predicts that the axis of eye rotation shifts slightly toward alignment with gravito-inertial force. The model also predicts that the time course of the perception of tilt following the acceleration phase of eccentric rotation is much slower than that during deceleration. During off vertical axis rotation (OVAR) the model predicts a small horizontal bias along with small horizontal, vertical, and torsional oscillations. Following OVAR stimulation, when stopped right- or left-side down, a small vertical component is predicted that decays with the horizontal post-rotatory response. All of the predictions are consistent with measurements of human responses.

Rotationally Molded Liquid Crystalline Polymers

NASA Technical Reports Server (NTRS)

Rogers, Martin; Stevenson, Paige; Scribben, Eric; Baird, Donald; Hulcher, Bruce

2002-01-01

Rotational molding is a unique process for producing hollow plastic parts. Rotational molding offers advantages of low cost tooling and can produce very large parts with complicated shapes. Products made by rotational molding include water tanks with capacities up to 20,000 gallons, truck bed liners, playground equipment, air ducts, Nylon fuel tanks, pipes, toys, stretchers, kayaks, pallets, and many others. Thermotropic liquid crystalline polymers are an important class of engineering resins employed in a wide variety of applications. Thermotropic liquid crystalline polymers resins are composed of semi-rigid, nearly linear polymeric chains resulting in an ordered mesomorphic phase between the crystalline solid and the isotropic liquid. Ordering of the rigid rod-like polymers in the melt phase yields microfibrous, self-reinforcing polymer structures with outstanding mechanical and thermal properties. Rotational molding of liquid crystalline polymer resins results in high strength and high temperature hollow structures useful in a variety of applications. Various fillers and reinforcements can potentially be added to improve properties of the hollow structures. This paper focuses on the process and properties of rotationally molded liquid crystalline polymers.

Mental Rotation: Cross-Task Training and Generalization

ERIC Educational Resources Information Center

Stransky, Debi; Wilcox, Laurie M.; Dubrowski, Adam

2010-01-01

It is well established that performance on standard mental rotation tasks improves with training (Peters et al., 1995), but thus far there is little consensus regarding the degree of transfer to other tasks which also involve mental rotation. In Experiment 1, we assessed the effect of mental rotation training on participants' Mental Rotation Test…

Split Venturi, Axially-Rotated Valve

DOEpatents

Walrath, David E.; Lindberg, William R.; Burgess, Robert K.

2000-08-29

The present invention provides an axially-rotated valve which permits increased flow rates and lower pressure drop (characterized by a lower loss coefficient) by using an axial eccentric split venturi with two portions where at least one portion is rotatable with respect to the other portion. The axially-rotated valve typically may be designed to avoid flow separation and/or cavitation at full flow under a variety of conditions. Similarly, the valve is designed, in some embodiments, to produce streamlined flow within the valve. A typical cross section of the eccentric split venturi may be non-axisymmetric such as a semicircular cross section which may assist in both throttling capabilities and in maximum flow capacity using the design of the present invention. Such a design can include applications for freeze resistant axially-rotated valves and may be fully-opened and fully-closed in one-half of a complete rotation. An internal wide radius elbow typically connected to a rotatable portion of the eccentric venturi may assist in directing flow with lower friction losses. A valve actuator may actuate in an axial manner yet be uniquely located outside of the axial flow path to further reduce friction losses. A seal may be used between the two portions that may include a peripheral and diametrical seal in the same plane.

Inertial measurement unit using rotatable MEMS sensors

DOEpatents

Kohler, Stewart M [Albuquerque, NM; Allen, James J [Albuquerque, NM

2007-05-01

A MEM inertial sensor (e.g. accelerometer, gyroscope) having integral rotational means for providing static and dynamic bias compensation is disclosed. A bias compensated MEM inertial sensor is described comprising a MEM inertial sense element disposed on a rotatable MEM stage. A MEM actuator drives the rotation of the stage between at least two predetermined rotational positions. Measuring and comparing the output of the MEM inertial sensor in the at least two rotational positions allows for both static and dynamic bias compensation in inertial calculations based on the sensor's output. An inertial measurement unit (IMU) comprising a plurality of independently rotatable MEM inertial sensors and methods for making bias compensated inertial measurements are disclosed.

Inertial measurement unit using rotatable MEMS sensors

DOEpatents

Kohler, Stewart M.; Allen, James J.

2006-06-27

A MEM inertial sensor (e.g. accelerometer, gyroscope) having integral rotational means for providing static and dynamic bias compensation is disclosed. A bias compensated MEM inertial sensor is described comprising a MEM inertial sense element disposed on a rotatable MEM stage. A MEM actuator for drives the rotation of the stage between at least two predetermined rotational positions. Measuring and comparing the output of the MEM inertial sensor in the at least two rotational positions allows, for both static and dynamic bias compensation in inertial calculations based on the sensor's output. An inertial measurement unit (IMU) comprising a plurality of independently rotatable MEM inertial sensors and methods for making bias compensated inertial measurements are disclosed.

Collecting the Puzzle Pieces: Completing HST's UV+NIR Survey of the TRAPPIST-1 System ahead of JWST

NASA Astrophysics Data System (ADS)

de Wit, Julien

2017-08-01

Using the Spitzer Space Telescope, our team has discovered 7 Earth-sized planets around the nearby Ultra-cool dwarf star TRAPPIST-1. These planets are the first to be simultaneously Earth-sized, temperate, and amenable for in-depth atmospheric studies with space-based observatories (notably, JWST). TRAPPIST-1's system thus provides us with the first opportunity to probe the atmospheres of Earth-sized exoplanets and search for signs of habitability beyond our solar system, which will require spectral information from the UV to the IR to complete their atmospheric puzzles.We request 114 HST orbits to complete the UV+NIR survey of the 7 planets in preparation for their in-depth followup with JWST. The suggested low-density of the planets combined with their complex orbital resonance chain indicate that they migrated inward to their current positions and may harbor large water rich reservoir or leftover primordial H2 atmospheres. We have already ruled out the presence of clear H2 atmospheres for the 5 innermost planets using WFC3 and are requesting 16 WFC3 orbits to complete the TRAPPIST-1 NIR reconnaissance survey. Our primary request consists in 98 STIS orbits to complete the survey for extended H-exospheres around each of the planets. H-exospheres are the most accessible observables for volatile reservoirs, which have not been ruled out by our WFC3 observations. Exosphere detection is only amenable using HST unique capabilities in the UV and are pivotal to guide JWST's in-depth followup. The combined information from HST's UV and NIR observations will allow us put the first critical pieces of the atmospheric puzzle in place for these temperate earth-sized worlds.

Venus - Atmospheric rotation.

NASA Technical Reports Server (NTRS)

Scott, A. H.; Reese, E. J.

1972-01-01

Photographs of Venus taken in ultraviolet light from Sept. 29, 1963, to May 29, 1971, indicate a general planet-wide circulation in the upper atmosphere of that planet having velocities which varied with time from -87 to -127m/sec at the equator. Positional measurements on 67 pairs of photographs which show the recurrence of similar patterns after intervals of one to three rotations suggest an asymmetric bimodal distribution of these velocities. The ultraviolet markings appear to be randomly distributed and quite ephemeral in nature, rarely enduring in a recognizable pattern for more than 20 days and usually much less. Attention is directed to an apparent but fictitious mean sidereal rotation period of approximately 4.06 days derived from observations which are made at a single station and span many months or years. Under such conditions this fictitious value for the rotation period is produced by the commensurability of the one-day period of earth and the assumed four-day period of the atmosphere of Venus.

Dynamic behaviour of a rotating cracked beam

NASA Astrophysics Data System (ADS)

Yashar, Ahmed; Ghandchi-Tehrani, Maryam; Ferguson, Neil

2016-09-01

This paper presents a new approach to investigate and analyse the vibrational behaviour of cracked rotating cantilever beams, which can for example represent helicopter or wind turbine blades. The analytical Hamiltonian method is used in modelling the rotating beam and two numerical methods, the Rayleigh-Ritz and FEM, are used to study the natural frequencies and the mode shapes of the intact rotating beams. Subsequently, a crack is introduced into the FE model and simulations are performed to identify the modal characteristics for an open cracked rotating beam. The effect of various parameters such as non-dimensional rotating speed, hub ratio and slenderness ratio are investigated for both the intact and the cracked rotating beam, and in both directions of chordwise and flapwise motion. The veering phenomena in the natural frequencies as a function of the rotational speed and the buckling speed are considered with respect to the slenderness ratio. In addition, the mode shapes obtained for the flapwise vibration are compared using the modal assurance criterion (MAC). Finally, a new three dimensional design chart is produced, showing the effect of crack location and depth on the natural frequencies of the rotating beam. This chart will be subsequently important in identifying crack defects in rotating blades.

Ultrasound determination of rotator cuff tear repairability

PubMed Central

Tse, Andrew K; Lam, Patrick H; Walton, Judie R; Hackett, Lisa

2015-01-01

Background Rotator cuff repair aims to reattach the torn tendon to the greater tuberosity footprint with suture anchors. The present study aimed to assess the diagnostic accuracy of ultrasound in predicting rotator cuff tear repairability and to assess which sonographic and pre-operative features are strongest in predicting repairability. Methods The study was a retrospective analysis of measurements made prospectively in a cohort of 373 patients who had ultrasounds of their shoulder and underwent rotator cuff repair. Measurements of rotator cuff tear size and muscle atrophy were made pre-operatively by ultrasound to enable prediction of rotator cuff repairability. Tears were classified following ultrasound as repairable or irreparable, and were correlated with intra-operative repairability. Results Ultrasound assessment of rotator cuff tear repairability has a sensitivity of 86% (p < 0.0001) and a specificity of 67% (p < 0.0001). The strongest predictors of rotator cuff repairability were tear size (p < 0.001) and age (p = 0.004). Sonographic assessments of tear size ≥4 cm2 or anteroposterior tear length ≥25 mm indicated an irreparable rotator cuff tear. Conclusions Ultrasound assessment is accurate in predicting rotator cuff tear repairability. Tear size or anteroposterior tear length and age were the best predictors of repairability. PMID:27582996

Internal rotation of the sun

NASA Technical Reports Server (NTRS)

Duvall, T. L., Jr.; Dziembowski, W. A.; Goode, P. R.; Gough, D. O.; Harvey, J. W.; Leibacher, J. W.

1984-01-01

The frequency difference between prograde and retrograde sectoral solar oscillations is analyzed to determine the rotation rate of the solar interior, assuming no latitudinal dependence. Much of the solar interior rotates slightly less rapidly than the surface, while the innermost part apparently rotates more rapidly. The resulting solar gravitational quadrupole moment is J2 = (1.7 + or - 0.4) x 10 to the -7th and provides a negligible contribution to current planetary tests of Einstein's theory of general relativity.

CONTROL ROD ROTATING MECHANISM

DOEpatents

Baumgarten, A.; Karalis, A.J.

1961-11-28

A threaded rotatable shaft is provided which rotates in response to linear movement of a nut, the shaft being surrounded by a pair of bellows members connected to either side of the nut to effectively seal the reactor from leakage and also to store up energy to shut down the reactor in the event of a power failure. (AEC)

Nugget Structure Evolution with Rotation Speed for High-Rotation-Speed Friction-Stir-Welded 6061 Aluminum Alloy

NASA Astrophysics Data System (ADS)

Zhang, H. J.; Wang, M.; Zhu, Z.; Zhang, X.; Yu, T.; Wu, Z. Q.

2018-03-01

High-rotation-speed friction stir welding (HRS-FSW) is a promising technique to reduce the welding loads during FSW and thus facilitates the application of FSW for in situ fabrication and repair. In this study, 6061 aluminum alloy was friction stir welded at high-rotation speeds ranging from 3000 to 7000 rpm at a fixed welding speed of 50 mm/min, and the effects of rotation speed on the nugget zone macro- and microstructures were investigated in detail in order to illuminate the process features. Temperature measurements during HRS-FSW indicated that the peak temperature did not increase consistently with rotation speed; instead, it dropped remarkably at 5000 rpm because of the lowering of material shear stress. The nugget size first increased with rotation speed until 5000 rpm and then decreased due to the change of the dominant tool/workpiece contact condition from sticking to sliding. At the rotation speed of 5000 rpm, where the weld material experienced weaker thermal effect and higher-strain-rate plastic deformation, the nugget exhibited relatively small grain size, large textural intensity, and high dislocation density. Consequently, the joint showed superior nugget hardness and simultaneously a slightly low tensile ductility.

Polarization Rotation and the Third Stokes Parameter: The Effects of Spacecraft Attitude and Faraday Rotation

NASA Technical Reports Server (NTRS)

Meissner, Thomas; Wentz, Frank J.

2006-01-01

The third Stokes parameter of ocean surface brightness temperatures measured by the WindSat instrument is sensitive to the rotation angle between the polarization vectors at the ocean surface and the instrument. This rotation angle depends on the spacecraft attitude (roll, pitch, yaw) as well as the Faraday rotation of the electromagnetic radiation passing through the Earth's ionosphere. Analyzing the WindSat antenna temperatures, we find biases in the third Stokes parameter as function of the along-scan position of up to 1.5 K in all feedhorns. This points to a misspecification of the reported spacecraft attitude. A single attitude correction of -0.16deg roll and 0.18deg pitch for the whole instrument eliminates all the biases. We also study the effect of Faraday rotation at 10.7 GHz on the accuracy of the third Stokes parameter and the sea surface wind direction retrieval and demonstrate how this error can be corrected using values from the International Reference Ionosphere for the total electron content when computing Faraday rotation.

Chaotic behavior in electro-rotation

NASA Astrophysics Data System (ADS)

Lemaire, E.; Lobry, L.

2002-11-01

We study the dynamics of an insulating cylinder in a weakly conducting liquid when submitted to a DC electric field. The cylinder is free to rotate along its long axis which is perpendicular to the applied field. Above a threshold value of the electric field, the cylinder rotates in either direction with constant angular velocity. This instability is known as Quincke rotation and can be easily understood by considering the polarization induced by the free charges accumulation on the cylinder surface. Here we present preliminary experimental results which exhibit a chaotic dynamics of the cylinder for higher electric fields: the velocity is no longer constant and the rotation direction changes randomly. By taking into account the finite Maxwell-Wagner polarization relaxation time, we show that this chaotic behavior can be described by the Lorenz equations.

Analysis of Petal Rotation Trajectory Characteristics

NASA Technical Reports Server (NTRS)

Anderson, Rodney L.; Campagnola, Stefano; Buffington, Brent B.

2014-01-01

In this study, the characteristics of petal rotation trajectories are explored in both the two-body and circular restricted three-body problem (CRTBP) models. Petal rotation trajectories alternate long and short resonances of different kinds to rotate the line of apsides. They are typically computed using the patched conic model, and they are used in a number of different missions and mission concepts including Cassini, JUICE, and Europa mission concepts. Petal rotation trajectories are first analyzed here using the patched conic model to quantify their characteristics and search for cases with fast rotation of the line of apsides. When they are computed in the CRTBP, they are unstable periodic orbits with corresponding stable and unstable manifolds. The characteristics of these orbits are explored from a dynamical systems perspective in the second phase of the study.

Mental object rotation and the planning of hand movements.

PubMed

Wohlschläger, A

2001-05-01

Recently, we showed that the simultaneous execution of rotational hand movements interferes with mental object rotation, provided that the axes of rotation coincide in space. We hypothesized that mental object rotation and the programming of rotational hand movements share a common process presumably involved in action planning. Two experiments are reported here that show that the mere planning of a rotational hand movement is sufficient to cause interference with mental object rotation. Subjects had to plan different spatially directed hand movements that they were asked to execute only after they had solved a mental object rotation task. Experiment 1 showed that mental object rotation was slower if hand movements were planned in a direction opposite to the presumed mental rotation direction, but only if the axes of hand rotation and mental object rotation were parallel in space. Experiment 2 showed that this interference occurred independent of the preparatory hand movements observed in Experiment 1. Thus, it is the planning of hand movements and not their preparation or execution that interferes with mental object rotation. This finding underlines the idea that mental object rotation is an imagined (covert) action, rather than a pure visual-spatial imagery task, and that the interference between mental object rotation and rotational hand movements is an interference between goals of actions.

Immobilization in External Rotation Versus Internal Rotation After Primary Anterior Shoulder Dislocation: A Meta-analysis of Randomized Controlled Trials.

PubMed

Whelan, Daniel B; Kletke, Stephanie N; Schemitsch, Geoffrey; Chahal, Jaskarndip

2016-02-01

The recurrence rate after primary anterior shoulder dislocation is high, especially in young, active individuals. Recent studies have suggested external rotation immobilization as a method to reduce the rate of recurrent shoulder dislocation in comparison to traditional sling immobilization. To assess and summarize evidence from randomized controlled trials on the effect of internal rotation versus external rotation immobilization on the rate of recurrence after primary anterior shoulder dislocation. Meta-analysis. PubMed, MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, and abstracts from recent proceedings were searched for eligible studies. Two reviewers selected studies for inclusion, assessed methodological quality, and extracted data. Six randomized controlled trials (632 patients) were included in this review. Demographic and prognostic variables measured at baseline were similar in the pooled groups. The average age was 30.1 years in the pooled external rotation group and 30.3 years in the pooled internal rotation group. Two studies found that external rotation immobilization reduced the rate of recurrence after initial anterior shoulder dislocation compared with conventional internal rotation immobilization, whereas 4 studies failed to find a significant difference between the 2 groups. This meta-analysis suggested no overall significant difference in the rate of recurrence among patients treated with internal rotation versus external rotation immobilization (risk ratio, 0.69; 95% CI, 0.42-1.14; P = .15). There was no significant difference in the rate of compliance between internal and external rotation immobilization (P = .43). The Western Ontario Shoulder Instability Index scores were pooled across 3 studies, and there was no significant difference between the 2 groups (P = .54). Immobilization in external rotation is not significantly more effective in reducing the recurrence rate after primary anterior shoulder dislocation than

Definition of a visuospatial dimension as a step forward in the diagnostic puzzle of nonverbal learning disability.

PubMed

Poletti, Michele

2017-01-01

Although clinically recognized for almost 50 years, the categorical distinction of specific learning disabilities due to an impairment of the nonverbal domain (nonverbal learning disability [NLD]) is still debated and controversial. Unsolved issues involve theoretical models, diagnostic criteria, rehabilitative interventions, and moderator factors. These issues are briefly overviewed to sustain the need for a shift toward dimensional approaches, as suggested by research domain criteria, as a step forward in the diagnostic puzzle of NLD. With this aim, a visuospatial dimension, or spectrum, is proposed, and then clinical conditions that may fit with its impaired side are systemized, while specifying in which conditions a visuospatial impairment may be considered an NLD.

Visualizing Compound Rotations with Virtual Reality

ERIC Educational Resources Information Center

Flanders, Megan; Kavanagh, Richard C.

2013-01-01

Mental rotations are among the most difficult of all spatial tasks to perform, and even those with high levels of spatial ability can struggle to visualize the result of compound rotations. This pilot study investigates the use of the virtual reality-based Rotation Tool, created using the Virtual Reality Modeling Language (VRML) together with…

Motor Processes in Children's Mental Rotation

ERIC Educational Resources Information Center

Frick, Andrea; Daum, Moritz M.; Walser, Simone; Mast, Fred W.

2009-01-01

Previous studies with adult human participants revealed that motor activities can influence mental rotation of body parts and abstract shapes. In this study, we investigated the influence of a rotational hand movement on mental rotation performance from a developmental perspective. Children at the age of 5, 8, and 11 years and adults performed a…

Rotation and rotation-vibration spectroscopy of the 0+-0- inversion doublet in deuterated cyanamide.

PubMed

Kisiel, Zbigniew; Kraśnicki, Adam; Jabs, Wolfgang; Herbst, Eric; Winnewisser, Brenda P; Winnewisser, Manfred

2013-10-03

The pure rotation spectrum of deuterated cyanamide was recorded at frequencies from 118 to 649 GHz, which was complemented by measurement of its high-resolution rotation-vibration spectrum at 8-350 cm(-1). For D2NCN the analysis revealed considerable perturbations between the lowest Ka rotational energy levels in the 0(+) and 0(-) substates of the lowest inversion doublet. The final data set for D2NCN exceeded 3000 measured transitions and was successfully fitted with a Hamiltonian accounting for the 0(+) ↔ 0(-) coupling. A smaller data set, consisting only of pure rotation and rotation-vibration lines observed with microwave techniques was obtained for HDNCN, and additional transitions of this type were also measured for H2NCN. The spectroscopic data for all three isotopic species were fitted with a unified, robust Hamiltonian allowing confident prediction of spectra well into the terahertz frequency region, which is of interest to contemporary radioastronomy. The isotopic dependence of the determined inversion splitting, ΔE = 16.4964789(8), 32.089173(3), and 49.567770(6) cm(-1), for D2NCN, HDNCN, and H2NCN, respectively, is found to be in good agreement with estimates from a simple reduced quartic-quadratic double minimum potential.

The Rigid Orthogonal Procrustes Rotation Problem

ERIC Educational Resources Information Center

ten Berge, Jos M. F.

2006-01-01

The problem of rotating a matrix orthogonally to a best least squares fit with another matrix of the same order has a closed-form solution based on a singular value decomposition. The optimal rotation matrix is not necessarily rigid, but may also involve a reflection. In some applications, only rigid rotations are permitted. Gower (1976) has…

Rotation of vertically oriented objects during earthquakes

NASA Astrophysics Data System (ADS)

Hinzen, Klaus-G.

2012-10-01

Vertically oriented objects, such as tombstones, monuments, columns, and stone lanterns, are often observed to shift and rotate during earthquake ground motion. Such observations are usually limited to the mesoseismal zone. Whether near-field rotational ground motion components are necessary in addition to pure translational movements to explain the observed rotations is an open question. We summarize rotation data from seven earthquakes between 1925 and 2009 and perform analog and numeric rotation testing with vertically oriented objects. The free-rocking motion of a marble block on a sliding table is disturbed by a pulse in the direction orthogonal to the rocking motion. When the impulse is sufficiently strong and occurs at the `right' moment, it induces significant rotation of the block. Numeric experiments of a free-rocking block show that the initiation of vertical block rotation by a cycloidal acceleration pulse applied orthogonal to the rocking axis depends on the amplitude of the pulse and its phase relation to the rocking cycle. Rotation occurs when the pulse acceleration exceeds the threshold necessary to provoke rocking of a resting block, and the rocking block approaches its equilibrium position. Experiments with blocks subjected to full 3D strong motion signals measured during the 2009 L'Aquila earthquake confirm the observations from the tests with analytic ground motions. Significant differences in the rotational behavior of a monolithic block and two stacked blocks exist.

Two routes to expertise in mental rotation.

PubMed

Provost, Alexander; Johnson, Blake; Karayanidis, Frini; Brown, Scott D; Heathcote, Andrew

2013-01-01

The ability to imagine objects undergoing rotation (mental rotation) improves markedly with practice, but an explanation of this plasticity remains controversial. Some researchers propose that practice speeds up the rate of a general-purpose rotation algorithm. Others maintain that performance improvements arise through the adoption of a new cognitive strategy-repeated exposure leads to rapid retrieval from memory of the required response to familiar mental rotation stimuli. In two experiments we provide support for an integrated explanation of practice effects in mental rotation by combining behavioral and EEG measures in a way that provides more rigorous inference than is available from either measure alone. Before practice, participants displayed two well-established signatures of mental rotation: Both response time and EEG negativity increased linearly with rotation angle. After extensive practice with a small set of stimuli, both signatures of mental rotation had all but disappeared. In contrast, after the same amount of practice with a much larger set both signatures remained, even though performance improved markedly. Taken together, these results constitute a reversed association, which cannot arise from variation in a single cause, and so they provide compelling evidence for the existence of two routes to expertise in mental rotation. We also found novel evidence that practice with the large but not the small stimulus set increased the magnitude of an early visual evoked potential, suggesting increased rotation speed is enabled by improved efficiency in extracting three-dimensional information from two-dimensional stimuli. © 2013 Cognitive Science Society, Inc.

Rotationally Molded Liquid Crystalline Polymers

NASA Technical Reports Server (NTRS)

Rogers, Martin; Scribben, Eric; Baird, Donald; Hulcher, Bruce

2002-01-01

Rotational molding is a unique process for producing hollow plastic parts. Rotational molding offers low cost tooling and can produce very large parts with complicated shapes. Products made by rotational molding include water tanks with capacities up to 20,000 gallons, truck bed liners, playground equipment, air ducts, Nylon fuel tanks, pipes, toys, stretchers, kayaks, pallets, and many others. Thermotropic liquid crystalline polymers are an important class of engineering resins employed in a wide variety of applications. Thermotropic liquid crystalline polymers resins are composed of semirigid, nearly linear polymeric chains resulting in an ordered mesomorphic phase between the crystalline solid and the isotropic liquid. Ordering of the rigid rod-like polymers in the melt phase yields microfibrous, self-reinforcing polymer structures with outstanding mechanical and thermal properties. Rotational molding of liquid crystalline polymer resins results in high strength and high temperature hollow structures useful in a variety of applications. Various fillers and reinforcements can potentially be added to improve properties of the hollow structures. This paper focuses on the process and properties of rotationally molded liquid crystalline polymers. This paper will also highlight the interactions between academia and small businesses in developing new products and processes.

Rotatable electric cable connecting system

NASA Technical Reports Server (NTRS)

Manges, D. R. (Inventor)

1985-01-01

A cable reel assembly is described which is particularly adapted for, but not limited to, a system for providing electrical connection of power and data signals between an orbiter vehicle, such as a space shuttle, and a recovered satellite. The assembly is comprised of two mutually opposing ring type structures having 180 deg relative rotation with one of the structures being held in fixed position while the other structure is rotatable. Motor controlled berthing latches and umbilical cable connectors for the satellite are located on the rim of the rotatable ring structure. The electrical cable assembly is fed in two sections from the orbiter vehicle into the outer rim portion of the fixed ring structure where they are directed inwardly and attached to two concentrically coiled metal bands whose respective ends are secured to inner and outer post members of circular sets of guide pins located on opposing circular plate members, one rotatable and one fixed. The cable sections are fed out as three output cable sections through openings in the central portion of the circular plate of the rotatable ring structure where they are directed to the latches and connectors located on its rim.

Orbital Wall Reconstruction with Two-Piece Puzzle 3D Printed Implants: Technical Note

PubMed Central

Mommaerts, Maurice Y.; Büttner, Michael; Vercruysse, Herman; Wauters, Lauri; Beerens, Maikel

2015-01-01

The purpose of this article is to describe a technique for secondary reconstruction of traumatic orbital wall defects using titanium implants that act as three-dimensional (3D) puzzle pieces. We present three cases of large defect reconstruction using implants produced by Xilloc Medical B.V. (Maastricht, the Netherlands) with a 3D printer manufactured by LayerWise (3D Systems; Heverlee, Belgium), and designed using the biomedical engineering software programs ProPlan and 3-Matic (Materialise, Heverlee, Belgium). The smaller size of the implants allowed sequential implantation for the reconstruction of extensive two-wall defects via a limited transconjunctival incision. The precise fit of the implants with regard to the surrounding ledges and each other was confirmed by intraoperative 3D imaging (Mobile C-arm Systems B.V. Pulsera, Philips Medical Systems, Eindhoven, the Netherlands). The patients showed near-complete restoration of orbital volume and ocular motility. However, challenges remain, including traumatic fat atrophy and fibrosis. PMID:26889349

The rotating universe.

NASA Astrophysics Data System (ADS)

Surdin, M.

A closed universe obeying the Hubble equation v = Hu·r, where Hu is the Hubble constant, is considered. It is shown that such a universe is equivalent to a universe rotating around one of its diameters at an angular velocity Ωu = Hu. If one revives Blackett's conjecture, viz., a rotating body creates at its center a magnetic dipole, one computes the value of the magnetic field as B ≅ 2.5×10-5G. Intergalactic magnetic fields of the order of 10-6G were deduced from observations.

Conjunct rotation: Codman's paradox revisited.

PubMed

Wolf, Sebastian I; Fradet, Laetitia; Rettig, Oliver

2009-05-01

This contribution mathematically formalizes Codman's idea of conjunct rotation, a term he used in 1934 to describe a paradoxical phenomenon arising from a closed-loop arm movement. Real (axial) rotation is distinguished from conjunct rotation. For characterizing the latter, the idea of reference vector fields is developed to define the neutral axial position of the humerus for any given orientation of its long axis. This concept largely avoids typical coordinate singularities arising from decomposition of 3D joint motion and therefore can be used for postural (axial) assessment of the shoulder joint both clinically and in sports science in almost the complete accessible range of motion. The concept, even though algebraic rather complex, might help to get an easier and more intuitive understanding of axial rotation of the shoulder in complex movements present in daily life and in sports.

Climate-Rotation Feedback on Mars

NASA Technical Reports Server (NTRS)

Bills, Bruce G.

1999-01-01

A new model is presented for the coupled evolution of climate and rotation, as applied to Mars. It has long been appreciated that changes in the orbital and rotational geometry of Mars will influence the seasonal and latitudinal pattern of insolation, and this will likely dominate climatic fluctuations on time scales of 10(exp 5) to 10(exp 7) years. Equally important, but less widely appreciated, is the influence climatic change can have on rotational dynamics. The primary means by which climate influences rotation is via its influence on transport of mass (volatiles and dust) into and out of the polar regions. Many important issues remain unresolved: What are the ages of the polar caps? What climatic periods are recorded in the polar layered deposits? What is the long term obliquity history? Additional information is contained in the original extended abstract.

Rotational Energy.

ERIC Educational Resources Information Center

Lockett, Keith

1988-01-01

Demonstrates several objects rolling down a slope to explain the energy transition among potential energy, translational kinetic energy, and rotational kinetic energy. Contains a problem from Galileo's rolling ball experiment. (YP)

Rotating Reverse-Osmosis for Water Purification

NASA Technical Reports Server (NTRS)

Lueptow, RIchard M.

2004-01-01

A new design for a water-filtering device combines rotating filtration with reverse osmosis to create a rotating reverse- osmosis system. Rotating filtration has been used for separating plasma from whole blood, while reverse osmosis has been used in purification of water and in some chemical processes. Reverse- osmosis membranes are vulnerable to concentration polarization a type of fouling in which the chemicals meant not to pass through the reverse-osmosis membranes accumulate very near the surfaces of the membranes. The combination of rotating filtration and reverse osmosis is intended to prevent concentration polarization and thereby increase the desired flux of filtered water while decreasing the likelihood of passage of undesired chemical species through the filter. Devices based on this concept could be useful in a variety of commercial applications, including purification and desalination of drinking water, purification of pharmaceutical process water, treatment of household and industrial wastewater, and treatment of industrial process water. A rotating filter consists of a cylindrical porous microfilter rotating within a stationary concentric cylindrical outer shell (see figure). The aqueous suspension enters one end of the annulus between the inner and outer cylinders. Filtrate passes through the rotating cylindrical microfilter and is removed via a hollow shaft. The concentrated suspension is removed at the end of the annulus opposite the end where the suspension entered.

Rotational Modulation and Activity Cycles at Rotational Extremes: 25 yrs of NURO Photometry for HII 1883

NASA Astrophysics Data System (ADS)

Milingo, Jackie; Saar, Steven; Marschall, Laurence

2018-01-01

We present a 25 yr compilation of V-band differential photometry for the Pleiades K dwarf HII 1883 (V660 Tau). HII 1883 has a rotational period of ~ 0.24 d and displays significant rotational modulation due to non-uniform surface brightness or "starspots". Preliminary work yields a cycle period of ~ 9 yrs and rotational shear (ΔP_rot/) considerably less than solar. HII 1883 is one of the fastest rotating single stars with a known cycle. With additional data available we compare newly determined P_cyc and ΔP_rot/ values with those of other stars, putting HII 1883 into the broader context of dynamo properties in single cool dwarfs.

Does a critical rotator cuff tear stage exist?: a biomechanical study of rotator cuff tear progression in human cadaver shoulders.

PubMed

Oh, Joo Han; Jun, Bong Jae; McGarry, Michelle H; Lee, Thay Q

2011-11-16

It is unknown at which stage of rotator cuff tear the biomechanical environment is altered. The purpose of this study was to determine if a critical rotator cuff tear stage exists that alters glenohumeral joint biomechanics throughout the rotational range of shoulder motion, and to evaluate the biomechanical effect of parascapular muscle-loading. Eight cadaver shoulders were used with a custom testing system. Four progressive rotator cuff tear stages were investigated on the basis of footprint anatomy. Three muscle-loading conditions were examined: rotator cuff only; rotator cuff with deltoid muscle; and rotator cuff, deltoid, pectoralis major, and latissimus dorsi muscles. Testing was performed in the scapular plane with 0°, 30°, and 60° of shoulder abduction. The maximum internal and external rotations were measured with 3.4 Nm of torque. The position of the humeral head apex with respect to the glenoid was calculated with use of a MicroScribe 3DLX digitizing system throughout the rotational range of motion. The abduction capability was determined as the abduction angle achieved with increasing deltoid load. Tear of the entire supraspinatus tendon significantly increased maximum external rotation and significantly decreased abduction capability with higher deltoid loads (p < 0.05). Tear of the entire supraspinatus tendon and half of the infraspinatus tendon significantly shifted the humeral head apex posteriorly at the midrange of rotation and superiorly at maximum internal rotation (p < 0.05). Loading the pectoralis major and latissimus dorsi muscles decreased the amount of humeral head elevation due to deltoid loading. Tear of the entire supraspinatus tendon was the critical stage for increasing rotational range of shoulder motion and for decreased abduction capability. Further tear progression to the infraspinatus muscle was the critical stage for significant changes in humeral head kinematics. The pectoralis major and latissimus dorsi muscles played an

Rotator Cuff Injuries - Multiple Languages

MedlinePlus

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Some current research in rotating-disc systems.

PubMed

Owen, J M; Wilson, M

2001-05-01

Rotating-disc systems are used to model the flow and heat transfer that occurs inside the cooling-air systems of gas-turbine engines. In this paper, recent computational and experimental research in three systems is discussed: rotor-stator systems, rotating cavities with superposed flow and buoyancy-induced flow in a rotating cavity. Discussion of the first two systems concentrates respectively on pre-swirl systems and rotating cavities with a peripheral inflow and outflow of cooling air. Buoyancy-induced flow in a rotating cavity is one of the most difficult problems facing computationalists and experimentalists, and there are similarities between the circulation in the Earth's atmosphere and the flow inside gas-turbine rotors. For this case, results are presented for heat transfer in sealed annuli and in rotating cavities with an axial throughflow of cooling air.

Optical high-resolution analysis of rotational movement: testing circular spatial filter velocimetry (CSFV) with rotating biological cells

NASA Astrophysics Data System (ADS)

Schaeper, M.; Schmidt, R.; Kostbade, R.; Damaschke, N.; Gimsa, J.

2016-07-01

Circular spatial filtering velocimetry (CSFV) was tested during the microscopic registration of the individual rotations of baker’s yeast cells. Their frequency-dependent rotation (electrorotation; ER) was induced in rotating electric fields, which were generated in a glass chip chamber with four electrodes (600 μm tip-to-tip distance). The electrodes were driven with sinusoidal quadrature signals of 5 or 8 V PP with frequencies up to 3 MHz. The observed cell rotation was of the order of 1-100 s per revolution. At each measuring frequency, the independent rotations of up to 20 cells were simultaneously recorded with a high-speed camera. CSFV was software-implemented using circular spatial filters with harmonic gratings. ER was proportional to the phase shift between the values of the spatial filtering signal of consecutive frames. ER spectra obtained by CSFV from the rotation velocities at different ER-field frequencies agreed well with manual measurements and theoretical spectra. Oscillations in the rotation velocity of a single cell in the elliptically polarized field near an electrode, which were resolved by CSFV, could not be visually discerned. ER step responses after field-on were recorded at 2500 frames per second. Analysis proved the high temporal resolution of CSFV and revealed a largely linear torque-friction relation during the acceleration phase of ER. Future applications of CSFV will allow for the simple and cheap automated high-resolution analysis of rotational movements where mechanical detection has too low a resolution or is not possible, e.g. in polluted environments or for gas and fluid vortices, microscopic objects, etc.

The Puzzle of Visual Development: Behavior and Neural Limits.

PubMed

Kiorpes, Lynne

2016-11-09

The development of visual function takes place over many months or years in primate infants. Visual sensitivity is very poor near birth and improves over different times courses for different visual functions. The neural mechanisms that underlie these processes are not well understood despite many decades of research. The puzzle arises because research into the factors that limit visual function in infants has found surprisingly mature neural organization and adult-like receptive field properties in very young infants. The high degree of visual plasticity that has been documented during the sensitive period in young children and animals leaves the brain vulnerable to abnormal visual experience. Abnormal visual experience during the sensitive period can lead to amblyopia, a developmental disorder of vision affecting ∼3% of children. This review provides a historical perspective on research into visual development and the disorder amblyopia. The mismatch between the status of the primary visual cortex and visual behavior, both during visual development and in amblyopia, is discussed, and several potential resolutions are considered. It seems likely that extrastriate visual areas further along the visual pathways may set important limits on visual function and show greater vulnerability to abnormal visual experience. Analyses based on multiunit, population activity may provide useful representations of the information being fed forward from primary visual cortex to extrastriate processing areas and to the motor output. Copyright © 2016 the authors 0270-6474/16/3611384-10$15.00/0.

Measurement of Small Optical Polarization Rotations

ERIC Educational Resources Information Center

Kraftmakher, Yaakov

2009-01-01

When data with and without an optically active sample are acquired simultaneously while one manually rotates the analyser, the graph of the first signal versus the second one is an ellipse whose shape shows the phase shift between the two signals; this shift is twice the optical rotation. There is no need to measure the rotation of the analyser or…

Centrifugally activated bearing for high-speed rotating machinery

DOEpatents

Post, Richard F.

1994-01-01

A centrifugally activated bearing is disclosed. The bearing includes an annular member that extends laterally and radially from a central axis. A rotating member that rotates about the central axis relative to the annular member is also included. The rotating member has an interior chamber that surrounds the central axis and in which the annular member is suspended. Furthermore, the interior chamber has a concave shape for retaining a lubricant therein while the rotating member is at rest and for retaining a lubricant therein while the rotating member is rotating. The concave shape is such that while the rotating member is rotating a centrifugal force causes a lubricant to be forced away from the central axis to form a cylindrical surface having an axis collinear with the central axis. This centrifugally displaced lubricant provides restoring forces to counteract lateral displacement during operation.

The ZnSe(110) puzzle - Comparison with GaAs(110)

NASA Technical Reports Server (NTRS)

Duke, C. B.; Paton, A.; Kahn, A.; Tu, D.-W.

1984-01-01

The surface structure of monocrystalline ZnSe(110) and of 4-5-nm-thick ZnSe(110) layers epitaxially grown on GaAs(110) is investigated by means of elastic LEED and AES; the results are analyzed using the computer programs and R-factor methods of Duke et al. (1981 and 1983), presented in graphs and tables, and compared to those for GaAs(110). Significant differences are attributed to bond-length-conserving outward rotation of Se and inward rotation of Zn in the top layer, with an angle of 4 deg between the actual plane of the cation-anion chain and the truncated bulk surface. The R intensities measured for ZnSe(110) and GaAs(110) are given as Rx = 0.22 and RI = 0.21 and Rx = 0.24 and RI = 0.16, respectively.

The background puzzle: how identical mutations in the same gene lead to different disease symptoms.

PubMed

Kammenga, Jan E

2017-10-01

Identical disease-causing mutations can lead to different symptoms in different people. The reason for this has been a puzzling problem for geneticists. Differential penetrance and expressivity of mutations has been observed within individuals with different and similar genetic backgrounds. Attempts have been made to uncover the underlying mechanisms that determine differential phenotypic effects of identical mutations through studies of model organisms. From these studies evidence is accumulating that to understand disease mechanism or predict disease prevalence, an understanding of the influence of genetic background is as important as the putative disease-causing mutations of relatively large effect. This review highlights current insights into phenotypic variation due to gene interactions, epigenetics and stochasticity in model organisms, and discusses their importance for understanding the mutational effect on disease symptoms. © 2017 Federation of European Biochemical Societies.

Rotational Symmetry Breaking in Baby Skyrme Models

NASA Astrophysics Data System (ADS)

Karliner, Marek; Hen, Itay

We discuss one of the most interesting phenomena exhibited by baby skyrmions - breaking of rotational symmetry. The topics we will deal with here include the appearance of rotational symmetry breaking in the static solutions of baby Skyrme models, both in flat as well as in curved spaces, the zero-temperature crystalline structure of baby skyrmions, and finally, the appearance of spontaneous breaking of rotational symmetry in rotating baby skyrmions.

Effects of Successive Rotation Regimes on Carbon Stocks in Eucalyptus Plantations in Subtropical China Measured over a Full Rotation.

PubMed

Li, Xiaoqiong; Ye, Duo; Liang, Hongwen; Zhu, Hongguang; Qin, Lin; Zhu, Yuling; Wen, Yuanguang

2015-01-01

Plantations play an important role in carbon sequestration and the global carbon cycle. However, there is a dilemma in that most plantations are managed on short rotations, and the carbon sequestration capacities of these short-rotation plantations remain understudied. Eucalyptus has been widely planted in the tropics and subtropics due to its rapid growth, high adaptability, and large economic return. Eucalyptus plantations are primarily planted in successive rotations with a short rotation length of 6~8 years. In order to estimate the carbon-stock potential of eucalyptus plantations over successive rotations, we chose a first rotation (FR) and a second rotation (SR) stand and monitored the carbon stock dynamics over a full rotation from 1998 to 2005. Our results showed that carbon stock in eucalyptus trees (TC) did not significantly differ between rotations, while understory vegetation (UC) and soil organic matter (SOC) stored less carbon in the SR (1.01 vs. 2.76 Mg.ha(-1) and 70.68 vs. 81.08 Mg. ha(-1), respectively) and forest floor carbon (FFC) conversely stored more (2.80 vs. 2.34 Mg. ha(-1)). The lower UC and SOC stocks in the SR stand resulted in 1.13 times lower overall ecosystem carbon stock. Mineral soils and overstory trees were the two dominant carbon pools in eucalyptus plantations, accounting for 73.77%~75.06% and 20.50%~22.39%, respectively, of the ecosystem carbon pool. However, the relative contribution (to the ecosystem pool) of FFC stocks increased 1.38 times and that of UC decreased 2.30 times in the SR versus FR stand. These carbon pool changes over successive rotations were attributed to intensive successive rotation regimes of eucalyptus plantations. Our eight year study suggests that for the sustainable development of short-rotation plantations, a sound silvicultural strategy is required to achieve the best combination of high wood yield and carbon stock potential.

Effects of Successive Rotation Regimes on Carbon Stocks in Eucalyptus Plantations in Subtropical China Measured over a Full Rotation

PubMed Central

Li, Xiaoqiong; Ye, Duo; Liang, Hongwen; Zhu, Hongguang; Qin, Lin; Zhu, Yuling; Wen, Yuanguang

2015-01-01

Plantations play an important role in carbon sequestration and the global carbon cycle. However, there is a dilemma in that most plantations are managed on short rotations, and the carbon sequestration capacities of these short-rotation plantations remain understudied. Eucalyptus has been widely planted in the tropics and subtropics due to its rapid growth, high adaptability, and large economic return. Eucalyptus plantations are primarily planted in successive rotations with a short rotation length of 6~8 years. In order to estimate the carbon-stock potential of eucalyptus plantations over successive rotations, we chose a first rotation (FR) and a second rotation (SR) stand and monitored the carbon stock dynamics over a full rotation from 1998 to 2005. Our results showed that carbon stock in eucalyptus trees (TC) did not significantly differ between rotations, while understory vegetation (UC) and soil organic matter (SOC) stored less carbon in the SR (1.01 vs. 2.76 Mg.ha-1 and 70.68 vs. 81.08 Mg. ha-1, respectively) and forest floor carbon (FFC) conversely stored more (2.80 vs. 2.34 Mg. ha-1). The lower UC and SOC stocks in the SR stand resulted in 1.13 times lower overall ecosystem carbon stock. Mineral soils and overstory trees were the two dominant carbon pools in eucalyptus plantations, accounting for 73.77%~75.06% and 20.50%~22.39%, respectively, of the ecosystem carbon pool. However, the relative contribution (to the ecosystem pool) of FFC stocks increased 1.38 times and that of UC decreased 2.30 times in the SR versus FR stand. These carbon pool changes over successive rotations were attributed to intensive successive rotation regimes of eucalyptus plantations. Our eight year study suggests that for the sustainable development of short-rotation plantations, a sound silvicultural strategy is required to achieve the best combination of high wood yield and carbon stock potential. PMID:26186367

Head Rotation Movement Times.

PubMed

Hoffmann, Errol R; Chan, Alan H S; Heung, P T

2017-09-01

The aim of this study was to measure head rotation movement times in a Fitts' paradigm and to investigate the transition region from ballistic movements to visually controlled movements as the task index of difficulty (ID) increases. For head rotation, there are gaps in the knowledge of the effects of movement amplitude and task difficulty around the critical transition region from ballistic movements to visually controlled movements. Under the conditions of 11 ID values (from 1.0 to 6.0) and five movement amplitudes (20° to 60°), participants performed a head rotation task, and movement times were measured. Both the movement amplitude and task difficulty have effects on movement times at low IDs, but movement times are dependent only on ID at higher ID values. Movement times of participants are higher than for arm/hand movements, for both ballistic and visually controlled movements. The information-processing rate of head rotational movements, at high ID values, is about half that of arm movements. As an input mode, head rotations are not as efficient as the arm system either in ability to use rapid ballistic movements or in the rate at which information may be processed. The data of this study add to those in the review of Hoffmann for the critical IDs of different body motions. The data also allow design for the best arrangement of display that is under the design constraints of limited display area and difficulty of head-controlled movements in a data-inputting task.

Rotating arc spark plug

DOEpatents

Whealton, John H.; Tsai, Chin-Chi

2003-05-27

A spark plug device includes a structure for modification of an arc, the modification including arc rotation. The spark plug can be used in a combustion engine to reduce emissions and/or improve fuel economy. A method for operating a spark plug and a combustion engine having the spark plug device includes the step of modifying an arc, the modifying including rotating the arc.

M Dwarf Rotation from the K2 Young Clusters to the Field. I. A Mass-Rotation Correlation at 10 Myr

NASA Astrophysics Data System (ADS)

Somers, Garrett; Stauffer, John; Rebull, Luisa; Cody, Ann Marie; Pinsonneault, Marc

2017-12-01

Recent observations of the low-mass (0.1-0.6 {M}⊙ ) rotation distributions of the Pleiades and Praesepe clusters have revealed a ubiquitous correlation between mass and rotation, such that late M dwarfs rotate an order-of-magnitude faster than early M dwarfs. In this paper, we demonstrate that this mass-rotation correlation is present in the 10 Myr Upper Scorpius association, as revealed by new K2 rotation measurements. Using rotational evolution models, we show that the low-mass rotation distribution of the 125 Myr Pleiades cluster can only be produced if it hosted an equally strong mass-rotation correlation at 10 Myr. This suggests that physical processes important in the early pre-main sequence (PMS; star formation, accretion, disk-locking) are primarily responsible for the M dwarf rotation morphology, and not quirks of later angular momentum (AM) evolution. Such early mass trends must be taken into account when constructing initial conditions for future studies of stellar rotation. Finally, we show that the average M star loses ˜25%-40% of its AM between 10 and 125 Myr, a figure accurately and generically predicted by modern solar-calibrated wind models. Their success rules out a lossless PMS and validates the extrapolation of magnetic wind laws designed for solar-type stars to the low-mass regime at early times.

Effects of scapular upward rotation exercises on alignment of scapula and clavicle and strength of scapular upward rotators in subjects with scapular downward rotation syndrome.

PubMed

Ha, Sung-min; Kwon, Oh-yun; Yi, Chung-hwi; Cynn, Heon-seock; Weon, Jong-hyuck; Kim, Tae-ho

2016-02-01

The purpose of this study was to investigate the effects of a 6-week scapular upward rotation exercise (SURE) on scapular and clavicular alignment and scapular upward rotators strength in subjects with scapular downward rotation syndrome (SDRS). Seventeen volunteer subjects with SDRS were recruited from university populations. The alignment of the scapula and clavicle was measured using radiographic analysis and compared in subjects before and after a 6-week self-SURE program. A hand-held dynamometer was used to measure the strength of the scapular upward rotators. The subjects were instructed how to perform the self-SURE program at home. The 6-week self-SURE program was divided into two sections (the first section with non-resistive SURE during weeks 1-3, and the second section with resistive SURE using thera-band during weeks 4-6). The significance of the difference between pre- and post-program was assessed using a paired t-test, with the level of statistical significance set at p<0.05. Significant differences between pre- and post-program were found for scapular and clavicular alignment (p<0.05). Additionally, the comparison between pre- and post-program measurements of the strength of the scapular upward rotators showed significant differences (p<0.05). The results of this study showed that a 6-week self-SURE program is effective for improving scapular and clavicular alignment and increasing the strength of scapular upward rotator muscles in subjects with SDRS. Copyright © 2015 Elsevier Ltd. All rights reserved.

Desiccation tolerance of Sphagnum revisited: a puzzle resolved.

PubMed

Hájek, T; Vicherová, E

2014-07-01

As ecosystem engineers, Sphagnum mosses control their surroundings through water retention, acidification and peat accumulation. Because water retention avoids desiccation, sphagna are generally intolerant to drought; however, the literature on Sphagnum desiccation tolerance (DT) provides puzzling results, indicating the inducible nature of their DT. To test this, various Sphagnum species and other mesic bryophytes were hardened to drought by (i) slow drying; (ii) ABA application and (iii) chilling or frost. DT tolerance was assessed as recovery of chlorophyll fluorescence parameters after severe desiccation. We monitored the seasonal course of DT in bog bryophytes. Under laboratory conditions, following initial de-hardening, untreated Sphagnum shoots lacked DT; however, DT was induced by all hardening treatments except chilling, notably by slow drying, and in Sphagnum species of the section Cuspidata. In the field, sphagna in hollows and lawns developed DT several times during the growing season, responding to reduced precipitation and a lowered water table. Hummock and aquatic species developed DT only in late autumn, probably as a response to frost. Sphagnum protonemata failed to develop DT; hence, desiccation may limit Sphagnum establishment in drier habitats with suitable substrate chemistry. Desiccation avoiders among sphagna form compact hummocks or live submerged; thus, they do not develop DT in the field, lacking the initial desiccation experience, which is frequent in hollow and lawn habitats. We confirmed the morpho-physiological trade-off: in contrast to typical hollow sphagna, hummock species invest more resources in water retention (desiccation avoidance), while they have a lower ability to develop physiological DT. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

Dynamics of Tidally Locked, Ultrafast Rotating Atmospheres

NASA Astrophysics Data System (ADS)

Tan, Xianyu; Showman, Adam P.

2017-10-01

Tidally locked gas giants, which exhibit a novel regime of day-night thermal forcing and extreme stellar irradiation, are typically in several-day orbits, implying slow rotation and a modest role for rotation in the atmospheric circulation. Nevertheless, there exist a class of gas-giant, highly irradiated objects - brown dwarfs orbiting white dwarfs in extremely tight orbits - whose orbital and hence rotation periods are as short as 1-2 hours. Spitzer phase curves and other observations have already been obtained for this fascinating class of objects, which raise fundamental questions about the role of rotation in controlling the circulation. So far, most modeling studies have investigated rotation periods exceeding a day, as appropriate for typical hot Jupiters. In this work we investigate the dynamics of tidally locked atmospheres in shorter rotation periods down to about two hours. With increasing rotation rate (decreasing rotation period), we show that the width of the equatorial eastward jet decreases, consistent with the narrowing of wave-mean-flow interacting region due to decrease of the equatorial deformation radius. The eastward-shifted equatorial hot spot offset decreases accordingly, and the westward-shifted hot regions poleward of the equatorial jet associated with Rossby gyres become increasingly distinctive. At high latitudes, winds becomes weaker and more geostrophic. The day-night temperature contrast becomes larger due to the stronger influence of rotation. Our simulated atmospheres exhibit small-scale variability, presumably caused by shear instability. Unlike typical hot Jupiters, phase curves of fast-rotating models show an alignment of peak flux to secondary eclipse. Our results have important implications for phase curve observations of brown dwarfs orbiting white dwarfs in ultra tight orbits.

Neoclassical poloidal and toroidal rotation in tokamaks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Y.B.; Diamond, P.H.; Groebner, R.J.

1991-08-01

Explicit expressions for the neoclassical poloidal and toroidal rotation speeds of primary ion and impurity species are derived via the Hirshman and Sigmar moment approach. The rotation speeds of the primary ion can be significantly different from those of impurities in various interesting cases. The rapid increase of impurity poloidal rotation in the edge region of H-mode discharges in tokamaks can be explained by a rapid steepening of the primary ion pressure gradient. Depending on ion collisionality, the poloidal rotation speed of the primary ions at the edge can be quite small and the flow direction may be opposite tomore » that of the impurities. This may cast considerable doubts on current L to H bifurcation models based on primary ion poloidal rotation only. Also, the difference between the toroidal rotation velocities of primary ions and impurities is not negligible in various cases. In Ohmic plasmas, the parallel electric field induces a large impurity toroidal rotation close to the magnetic axis, which seems to agree with experimental observations. In the ion banana and plateau regime, there can be non-negligible disparities between primary ion and impurity toroidal rotation velocities due to the ion density and temperature gradients. Detailed analytic expressions for the primary ion and impurity rotation speeds are presented, and the methodology for generalization to the case of several impurity species is also presented for future numerical evaluation.« less

Central Rotations of Milky Way Globular Clusters

NASA Astrophysics Data System (ADS)

Fabricius, Maximilian H.; Noyola, Eva; Rukdee, Surangkhana; Saglia, Roberto P.; Bender, Ralf; Hopp, Ulrich; Thomas, Jens; Opitsch, Michael; Williams, Michael J.

2014-06-01

Most Milky Way globular clusters (GCs) exhibit measurable flattening, even if on a very low level. Both cluster rotation and tidal fields are thought to cause this flattening. Nevertheless, rotation has only been confirmed in a handful of GCs, based mostly on individual radial velocities at large radii. We are conducting a survey of the central kinematics of Galactic GCs using the new Integral Field Unit instrument VIRUS-W. We detect rotation in all 11 GCs that we have observed so far, rendering it likely that a large majority of the Milky Way GCs rotate. We use published catalogs of GCs to derive central ellipticities and position angles. We show that in all cases where the central ellipticity permits an accurate measurement of the position angle, those angles are in excellent agreement with the kinematic position angles that we derive from the VIRUS-W velocity fields. We find an unexpected tight correlation between central rotation and outer ellipticity, indicating that rotation drives flattening for the objects in our sample. We also find a tight correlation between central rotation and published values for the central velocity dispersion, most likely due to rotation impacting the old dispersion measurements. This Letter includes data taken at The McDonald Observatory of The University of Texas at Austin.

Rotational spectroscopy with an optical centrifuge.

PubMed

Korobenko, Aleksey; Milner, Alexander A; Hepburn, John W; Milner, Valery

2014-03-07

We demonstrate a new spectroscopic method for studying electronic transitions in molecules with extremely broad range of angular momentum. We employ an optical centrifuge to create narrow rotational wave packets in the ground electronic state of (16)O2. Using the technique of resonance-enhanced multi-photon ionization, we record the spectrum of multiple ro-vibrational transitions between X(3)Σg(-) and C(3)Πg electronic manifolds of oxygen. Direct control of rotational excitation, extending to rotational quantum numbers as high as N ≳ 120, enables us to interpret the complex structure of rotational spectra of C(3)Πg beyond thermally accessible levels.

Robust rotational-velocity-Verlet integration methods.

PubMed

Rozmanov, Dmitri; Kusalik, Peter G

2010-05-01

Two rotational integration algorithms for rigid-body dynamics are proposed in velocity-Verlet formulation. The first method uses quaternion dynamics and was derived from the original rotational leap-frog method by Svanberg [Mol. Phys. 92, 1085 (1997)]; it produces time consistent positions and momenta. The second method is also formulated in terms of quaternions but it is not quaternion specific and can be easily adapted for any other orientational representation. Both the methods are tested extensively and compared to existing rotational integrators. The proposed integrators demonstrated performance at least at the level of previously reported rotational algorithms. The choice of simulation parameters is also discussed.

Robust rotational-velocity-Verlet integration methods

NASA Astrophysics Data System (ADS)

Rozmanov, Dmitri; Kusalik, Peter G.

2010-05-01

Two rotational integration algorithms for rigid-body dynamics are proposed in velocity-Verlet formulation. The first method uses quaternion dynamics and was derived from the original rotational leap-frog method by Svanberg [Mol. Phys. 92, 1085 (1997)]; it produces time consistent positions and momenta. The second method is also formulated in terms of quaternions but it is not quaternion specific and can be easily adapted for any other orientational representation. Both the methods are tested extensively and compared to existing rotational integrators. The proposed integrators demonstrated performance at least at the level of previously reported rotational algorithms. The choice of simulation parameters is also discussed.

Microfabricated microengine with constant rotation rate

DOEpatents

Romero, Louis A.; Dickey, Fred M.

1999-01-01

A microengine uses two synchronized linear actuators as a power source and converts oscillatory motion from the actuators into constant rotational motion via direct linkage connection to an output gear or wheel. The microengine provides output in the form of a continuously rotating output gear that is capable of delivering drive torque at a constant rotation to a micromechanism. The output gear can have gear teeth on its outer perimeter for directly contacting a micromechanism requiring mechanical power. The gear is retained by a retaining means which allows said gear to rotate freely. The microengine is microfabricated of polysilicon on one wafer using surface micromachining batch fabrication.

DEVICE FOR CONVEYING AND ROTATING OBJECTS

DOEpatents

Frantz, C.E.; Roslund, J.

1958-01-21

A device is described for conveying cylindrical material with a combined rotary and axial motion. The material rides on a series of balls which are retained in a guide plate and rotated by bearing against a rotating drum. The drum has a series of conical sections or grooves cut in its outer surface on which the balls ride. The grooves and balls match in such a way that all the balls are caused to rotate about an axis at an angle to the drum axis. This skewed rotation of the ball imparts a longitudinal as well as a rotary motion to the cylinders being conveyed.