Pipe Cleaners Research Articles

Assistência de ar na deposição e perdas de produtos fitossanitários em pulverizações na cultura da soja

Com o objetivo de se comparar a deposição e as perdas em pulverizações na cultura da soja dois pulverizadores tratorizados de barra sendo um convencional (Condor M12-Jacto) e outro com assistência de ar junto a barra de pulverização (Columbia Vortex-Jacto) foram calibrados para aplicar 100 L ha-1, respectivamente das soluções de NaCl e KCl a 2% (p/v) à pressão de 207 kPa (30 lbf pol-2)e velocidade de 6 km h-1. Ambos os equipamentos utilizaram bicos de jato plano tipo API 110-1,5 espaçados a 0,5 m trabalhando a 0,4 m acima da cultura. A avaliação da deposição deu-se em folhas das partes superior, média e inferior das plantas e as perdas para o solo em alvos artificiais (placas de fórmica) distribuídos no interior da cultura de soja. Além desse alvo artificial outros tipos de coletores (limpadores de cachimbo) também foram utilizados em ambos os lados da cultura para se estimar a deriva. Os resultados mostraram que não houve diferença significativa na deposição entre os equipamentos em teste na parte superior das plantas de soja, mas houve diferença significativa nos depósitos obtidos nos terços médio e inferior, com vantagem para o equipamento com assistência de ar. A deriva foi consideravelmente maior para o equipamento convencional nas mesmas condições meteorológicas.

Flexible Straws

Using drinking straws to construct geometric figures, has been a common activity for years. To join the straws, many different materials have been used—plasticine, marshmallows, paper clips. pipe cleaners. and so on. Here is a new twist, or should I say “flex.” to this topic.

Hands-on Activities That Relate Mendelian Genetics to Cell Division

What biology teacher hasn't engaged his or her students in the re-enactment of cell division with chromosomes contructed of materials ranging from pipe cleaners to peanuts? Students diligently work through the phases, putting to memory the sequence of events of each stage. Hopefully, they emerge from the activity with insight into differences and similarities between mitosis and meiosis. However, the greater significance of meiosis as the mechanism underlying Mendel's laws of segregation and independent assortment is rarely taught (Moll & Allen 1987). Teachers may make reference back to meiosis with the discussion of linked genes, but without a review of the process, it is likely to be a faded recollection. Our objective was to design handson activities that would connect Mendelian laws with the physical process of cell division. The Meiosis/Mitosis Game concentrates on separation of genetic material during cell division and sexual fusion. This is followed by the Genetics Game, where Mendelian genetics is tied to the process of meiosis. Our instruments are inexpensive paper chromosomes that carry commonly taught genes (see Figures 1 to 3) on their surface. Though designed for college biology courses, they have been used without alteration by high school teachers.

A Hands-on Approach to Teaching about DNA Structure and Function

In light of the ever-increasing importance of genetic research to the ordinary citizen as well as to the biologist, it seems imperative to ensure that our biology students gain a thorough understanding of the structure and function of DNA. This instruction should include the way in which DNA replicates and the process of transcription in which the codes for various proteins are passed on to the ribosomes by the mRNA. We became dissatisfied with the laboratory activities available at the high school level for developing concepts in molecular genetics. The students who appeared not yet able to carry out formal operational thought were having a particularly difficult time conceptualizing the structure of DNA. We thought that a more concrete activity would allow our students to meaningfully visualize the structure and function of DNA. The laboratory investigations illustrated here seemed to accomplish these goals. Our goal was to develop a manipulative activity using inexpensive but graphic materials. The materials used were two sizes of paper clips, an assortment of colored pipe cleaners, and flat styrofoam sheeting, such as that used for building insulation. Advance preparation consisted only of cutting the pipe cleaners into approximately 5 cm lengths, spray-painting part of the paper clips, and cutting the 2-cm-thick styrofoam sheeting into pieces approximately 3 cm by 7 cm. Be sure to have plenty of paper clips available for each student. The investigations can be used before or after class discussion of DNA structure, as all the information needed is included in the Background section of the paper supplied to the student. The format of the investigations was patterned after the Extending Discretion Approach (Leonard, 1980; 1981), but the steps are very specific in order to make sure the desired results are obtained. Allowing the students to watch what happens with the models appears to aid in their understanding of both replication and transcription. The first part of the investigation has the student make model nucleotides and then form them into a model of DNA to show how the nucleotides act as building blocks. Students demonstrate replication using the flat DNA model and free nucleotides and make a somewhat three-dimensional model to visualize the double helix. The flat and twisted DNA models are shown in Photo 1 and Photo 2 respectively. The second part of the lab deals with mRNA and has the students again form nucleotides and make a model using slightly different materials, thus demonstrating the differences between mRNA and DNA. They demonstrate transcription using the flat DNA model and the mRNA nucleotides. Each part of the investigation may take a full class period, so they are separate activities. After completing the investigation, the students write a report summarizing what they have learned about the structure and function of the two compounds. The actual printed laboratory procedures given to the students are shown in Boxes 1 and 2. In working with the student during Photo 1. The flat model of DNA creates a concrete visual aid for understanding DNA structure. Photo 2. With a twist of the wrist, an idea of the double helix is suggested.

The Short-Term Dynamics of Social Organization in Preschool Triads

Sequential dependencies in solitary and interactive states of social organization were examined as a function of age, sex, and type of toy in 12 triads of 3 1/2- and 5-year-old children. Each triad was observed during 2 30-min sessions, one in which objects with highly specific functions (e.g., dolls, trucks) were available, and one in which objects with relatively ambiguous functions (e.g., pipe cleaners, cardboard cylinders) were present. The results indicated that, while old and young triads did not differ in the tendency to initiate triadic interaction when the preceding state was solitary, old triads were more likely than young triads to maintain the triadic state and to shift to that state from the dyadic state. Boy triads were more likely than girl triads to remain in a solitary state and less likely to shift to and remain in a dyadic state, though no sex difference was found in the transition probabilities when the preceding state was triadic. Triads were more likely to remain in a solitary state in the presence of high-specificity toys than in the presence of low-specificity toys. Verbal metacommunication was more frequent among old triads than young triads, and it facilitated maintenance, but not initiation, of interactive states. The distinction between initiation and maintenance tendencies was formalized in a Markov model of the dynamics of social organization, and the parameter estimates yielded by the model were used to provide a simplified description of the "main" effects of age, sex, and type of toy. It is argued that models such as this one are useful in circumventing certain restrictions on the possible interpretations of raw sequential statistics.

The Effects of the Structure of Play Objects on the Pretend Play of Low-Income Preschool Children

McLoYD, VONNIE C. The Effects of the Structure of Play Objects on the Pretend Play of LowIncome Preschool Children. CHriLD DEVELOPMENT, 1983, 54, 626-635. The effects of highstructure versus low-structure objects on various types and components of pretend play in a sample of 36 low-income, predominantly Afro-American preschoolers were examined. Competing hypotheses, derived from the work of Piaget and El'Konin, and claims about the relative holding power of low-structure and high-structure toys, were tested. 12 triads of children, equally divided by age and sex, were observed in 4 30-min play sessions. In 2 of the sessions, high-structure or replica objects (e.g., tea sets, dolls, trucks) were available; in the remaining 2, low-structure objects (e.g., pipe cleaners, blocks, boxes) were provided. The results were generally consistent with El'Konin's analysis of symbolic play development. Highstructure objects, compared with low-structure objects, significantly increased noninteractive pretend play in 312-year-old triads, but not in 5-year-old triads. High-structure objects also elicited significantly more associative pretend play and overall pretend play. However, the structure of the play objects did not significantly affect cooperative pretend play. Substitution was more frequent with low-structure objects, while high-structure objects were associated with more pretend themes and onomatopoeia.

Coping Saw Blades and Pipe Cleaners as Endodontic Tools

Coping Saw Blades and Pipe Cleaners as Endodontic Tools

Hearing Aids: A Daily Check (review)

Reviews Meadow-Kendall Social-Emotional Assessment Inventory for Deaf Students, Kathryn P. Meadow, Ph.D. (& Colleagues at Kendall School), $11.00 for the Manual and scoring overlays (Manual alone, $3.00; inventories are distributed in packets of 10 for $1.50 per packet), OUTREACH, Pre-College Programs, Box 114, Gallaudet College, Washington, D.C. 20002. Dr. Meadow and her colleagues at the Kendall Demonstration School have made a major contribution to the psychological evaluation of deaf children with the development of this behavioral rating scale. It will be of particular value in programs where there are no psychologists skilled in working with deaf youth. It is usable with hearing-impaired children ages 7-20, and it can be administered and scored by teacher, psychologist, psychiatrist, social worker, or other professional. Norms and validation are satisfactory. McCay Vernon, Ph.D. Editor American Annals of the Deaf Western Maryland College Westminster, Md. 21157 Douglas Tilden: Portrait of a Deaf Sculptor, Mildred Albronda, 144 pp., T. J. Publishers, Inc., 817 Silver Spring Avenue, Silver Spring, Md. 20910,1980. Perhaps because his fall from fame and fortune was much more gradual than his rise, Douglas Tilden today is a practically forgotten man. Yet, as Ms. Albronda's biography reveals, Tilden's career and life deserve much broader recognition. Tilden was no solitary genius like a Beethoven or a Goya, but a "genuine" deaf man in the sense that he had attended a school for the deaf and was an activist in the cause of the deaf (and even at one time President of the California Association of the Deaf). Given this background, his achievements are amazing and his career offers food for thought. After achieving recognition in the then art capital of the world, Paris, he returned to San Francisco and was commissioned to commemorate California heroes and history in monumental bronze statuary , of which the most outstanding specimen is the famous Mechanics Monument in San Francisco. He gained national renown and wealth, was feted by the great, had a mansion built to his specifications, and his doings were chronicled in the press. He also was no mean writer; he once won first prize for a story he submitted to The Overland Monthly. Then after 1900 his decline began: Trends in art changed and he refused to go along with revolutionary modern art. His commissions stopped, his wife abandoned him, the public lost interest in him, and this once extremely wealthy artist was reduced to begging for a teaching job and working in a machine shop. As if to compound the irony, Tilden, the man whom the press used to call "the Michelangelo of the West," ended up sculpturing papiermache dinosaurs for Hollywood films. Few men, deaf or not, have experienced such a dizzying ascent to glory and wealth, followed by such a dismaying descent. Ms. Albronda deserves our thanks for resurrecting this remarkable deaf artist in her biography. Bernard Bragg Theatre Arts Department Gallaudet College Washington, D.C. 20002 Hearing Aids: A Daily Check (an audio-visual program ), sound filmstrip $45.00, slide/tape $75.00, Design Media, 327 17th St., Oakland, Calif. 94612, 1980. This sound filmstrip presents a step-by-step procedure for checking hearing aids, trouble shooting, and making minor repairs. The parts of an ear level hearing aid are named and clearly pointed out. Mention is made of the body aid but less attention is given to its use. The daily check procedure is outlined very specifically, including directions such as "switch off and remove the child's aid." Also included are specific sounds (ahh, ooh, eeh, shh, sss) or sentences to be presented in checking the aid. The specificity of this program makes it helpful for parents and beginning speech and hearing or education students. The program covers equipment needed to check a hearing aid, such as a personal ear mold or stethoscope and pipe cleaners and shows how these can be used. Finally, trouble-shooting steps are provided. Common hearing aid problems are presented with steps for dealing with these problems. For example, feedback may be caused by wax buildup , in which case the solution would simply be to clean the ear mold. However, this same problem...

On My Drawings and Paintings: An Extension of the System of Their Classification

After considering alternative systemsfor classifying the basic shapes in his drawing and paintings, the author proposes additions to the classification system he presented in hisfirst article in Leonardo. One addition involves a specification of the way in which V-, Tand X-intersections in shapes in the pencil drawings are shaded. Another addition makes use of the Ostwald color system to specify the one, two or three colors employed in the paintings. Also he discusses 'contradictory' aspects of shapes in his drawings and presents a subclassification based upon whether or not the shapes can represent possible 3-dimensionalforms. In conclusion, he discusses how two classes of shapes in his drawings can be transformed into forms in bas-reliefs and raised-line embossings. He closes with a commentary on the interpretation of his works. I. CLASSIFICATION OF BASIC SHAPES In my first article published in Leonardo I presented examples of my drawings and paintings and a system for their classification [1]. Each of these works is based on a basic shape that is derived from one or more closed curves. In the classification system, each work is designated by four numbers: I, (the number of closed curves employed in deriving the basic shape) and 12, 3 and 14 (the number of line intersections of each of three types, V, T and X, respectively, in the basic shape). I realize that my choice of system is not unique. For example, I have considered Euler's theorem in graph theory, that states that, for a connected planar graph with v intersections and g connecting lines that partition a plane into r regions: v q + r = 2 [2, 3]. My 67 classified basic shapes (except 11-7, III-1 and III-9) are connected planar graphs [1, Figs. 1, 2]. For the 64 shapes I find that v = I2 + 1 + I, q = 12 3 1 + 2 I3 + 2 14 and r = 2 + I3 + I4. Thus, as classification criteria, the set (v, q, r) is equivalent to the set (12, 13, 14). However, implicit in my use of 13 and I4 is knowledge about branch continuity at Tand X-interesections, while use of Euler's parameters does not imply anything about the continuity of branches. Thus the set (I2, 13, 14) gives more descriptively useful information than the set (v, q, r). My classification system is made more specific by the inclusion of the parameter II, which gives 3dimensional information, because I visualize in space forms to which the basic shapes apply. In some cases I made models of forms from pipe cleaners before executing the corresponding paint*10533 Sierra Bonita Ave., NE, Albuquerque, NM 87111, U.S.A. (Received 8 Jan. 1980) ing or drawing (for example, 'III-12: Coil' (Fig. 6)). I will gladly supply further information about classification based on Euler's parameters to those interested. II. CLASSIFICATION OF SHADING IN BASIC SHAPES (DRAWINGS) In the case of the pencil drawings I have found a way to make their classification more specific by introducing the criterion of intersection shading to add to the four criteria I I, 1I, I3,4. I require that, at each branch of an intersection, one side of the line (branch) be shaded darker than the other side in order to delineate the boundary. Thus at a Vintersection, four kinds of shading are possible; at a T-intersection, eight; at an X-intersection, 16. These 28 kinds are presented in Fig. 1, where the shading employed indicates on which side of a branch in a drawing the shading is darker. I group together in blocks (Fig. 1) those kinds that are equivalent if the angle between successive noncontinuous branches is changed and/or if a mirror reversal of the whole intersection shading diagram is made. This reduces the essential total number of shading types for all 3 kinds of intersections to 10. Each block is indicated by a designation such as Va or Xd. Tables I and II show that I have employed all the shading types except Ta in drawings. However, a number of sketches exhibiting type Ta shading are in my notebooks, awaiting to be executed as full-scale drawings. Note that shading type Va corresponds to a tonal inversion, discussed earlier [1, Fig. 10]. The percentage occurrence of each shading type in completed drawings is as follows: Td: 31%; Va: 26%; Tc: 23%; Tb: 9%; Xd: 4%; Xc: 2.5%; Xb, Vb, X, and Ta: under 2%.

The Smokeless Pipe

To the Editor:— Dr. Friederici's invention ( 211 :2016, 1970) delighted me and filled me with hope. I found a suitable mouthpiece at Kress's and constructed one of my very own. Alas, on first trial, it was obvious that it was a failure. The delightful searing pain along the lateral margin of the tongue was just not there. After considerable experimentation, I found that a concentrated extract of used pipe cleaners applied to the mouthpiece produced the desired effect, especially if heated. I developed a small kit to facilitate the use of this extract. It consists of a spoon, a medicine dropper, and a few matches. Yesterday, I was heating my extract and, for reason beyond my comprehension, lost a great deal of time discussing the invention with a state narcotics agent. I have gone back to a tobacco pipe but research continues. Soon I shall receive a supply of betel

Some simple models for the double quartet approach

Pipe cleaners are used to construct simple models for the double quartet or electronic repulsion theory.

Pipe cleaners and loops—discovering how to add and subtract directed numbers

Pipe cleaners and loops—discovering how to add and subtract directed numbers