Use Of Arrows Research Articles

Where have all the arrows gone? A cross-cultural comparison of Lowland Maya and Central Ohio arrow use

Where have all the arrows gone? A cross-cultural comparison of Lowland Maya and Central Ohio arrow use

An Automobile's Tail Lights: Sacrificing Safety for Playful Design?

The counterintuitive "Union Jack"-inspired turn signals on versions of BMW's Mini vehicles was investigated to reveal potential impacts on human performance. When some Mini drivers indicate a change in direction, they do so with an oppositely oriented arrow. This conflict, between the task-irrelevant spatial shape and task-relevant location of the signal, mimics a "converse" spatial-Stroop effect that, in combination with the ubiquitous use of arrows on road signs, may be confusing. Participants (n = 30) responded-via right and left keypresses-to the directions of road signs and turn signals in both pure and mixed blocks. Reaction times and accuracies were recorded to determine performance in each condition (compatible, neutral, incompatible). Performance suffered when the location and direction of the stimuli did not correspond. When responding to turn signals the cost to performance was especially salient in mixed blocks. Thus, when driving on roads where the meanings of arrows on road signs is important, turn signals pointing in a direction opposite from the directional intention indicated by the signals' location are likely to be confusing. The design of some Mini's "Union Jack" style taillights opposes well-established principles of cognitive functioning, caused confusion in our laboratory study and therefore may be a safety hazard-a possibility that ought to be explored in more realistic (e.g., driving simulator) situations. BMW designers should consider universally adopting the neutral, "horizontal line," illumination style that is currently available in the aftermarket.

USO DE SETAS NO CONTEXTO DA APRENDIZAGEM EM QUÍMICA E A IMPORTÂNCIA DO SEU SIMBOLISMO

USE OF ARROWS IN THE CONTEXT OF LEARNING IN CHEMISTRY AND THE IMPORTANCE OF ITS SYMBOLISM. The representation of arrows in Chemistry learning is routinely applied in classrooms and textbooks. Arrows of different shapes like horizontal, curved, vertical, or wavy have been used as symbols since the beginning of ancient civilizations, representing elements or compounds. The arrow is one of the most used symbols in Chemistry, as different types have presented different functions, especially in chemical reactions, and because there is no consensus, their use has generated ambiguities and confusion when applying them. In this sense, the present work sought to present and differentiate the types of arrows used in Chemistry to provide a better understanding of this symbol in the learning process. Furthermore, a historical overview of the emergence of arrows in the world of chemistry and the process of acceptance as chemical symbolism in chemical reactions is provided. The use of arrows in some chemical phenomena (e.g., resonance, tautomerism, symmetry operations, and movement of electrons) is also detailed. This work reflects that arrows, as chemical symbolism, require an increasingly concrete standardized notation system to avoid ambiguities of concepts. Finally, when using them, let us consider why the arrow is being symbolized and, above all, what is the scientific concept behind its symbolism.

Arrow shot injury to the oro facial regions: Report of two cases

Background: Arrow injury is a case of foreign body impaction. It can affect any part of the body. Arrow injury to the head and neck region can be life-threatening. An arrow is a weapon consisting of a thin, straight stick with a sharp point, designed to be shot from a bow. It is one of the oldest tools for hunt and war. Many health practitioners especially in the developed world now regard arrows as extinct. It has been completely replaced by advanced modern weaponry. This is not the case in our environment where the use of arrows with their attendant injury is still relatively common.
 Case report: The first case is a 25-year-old farmer, a Nigerian man was seen at the Accident and emergency unit of our centre with an hour history of arrow injury to the right side of the face following the farmer-herder clash. The examination was remarkable for an impacted arrow that was made up iron (impregenation with poisonous substance could not be ascertained) on the right side of the face. He had an urgent plain radiograph of the head and neck which revealed an impacted arrow in the right zygomatic bone. He subsequently had emergency exploration and removal of the arrow. The post-operative period was uneventful.
 The second case was a 37-year-old man who presented to the accident and emergency department with difficulty breathing following an arrow shot injury to the oral cavity. He was a passenger in a bus that was attacked by armed bandits. On examination, there was an arrow penetrating through the right edge of the tongue, the floor of the mouth to the contralateral submandibular and cervical regions. About 5.0cm of the tail of the arrow could be seen jutting out of the mouth. The exploration was done via a Risdon incision (submandibular incision) on the opposite side of the entry wound (left submandibular) in a retrograde approach. The dissection was advanced into the subcutaneous tissue, platysma, and deep fascial plane to expose the tip of the arrow. The post-operative period was uneventful.
 Conclusion: We have illustrated our experience on the cases of arrow injury to the orofacial region. The two cases presented early. There was no pre-hospital attempt at pulling out the arrow. Arrow injury is still common in our community. There is a need for government at all levels to intensify effort on conflict management and resolution.

Definition of conceptual basics of nanoeconomics as inclusive society environment

The definition of nanoeconomics can relate to different levels and areas of economic life. First of all, this is the nanolevel of the economic system. As a human economy, nanoeconomics provides for the allocation of an individual factor within the framework of a socio-economic phenomenon. The nanoeconomic aspect is central to the definition of inclusion. So, the inclusion of a person, as the main subject of nanoeconomics, to the formation and stabilization of economic systems is the initial one in the integration of an individual in relation to production processes and economic development. A person is involved in academic and social life by making decisions about their own business and integrating it into the sectoral and national economic space. It is proved that its indicators are the conditions for clustering the economic system. The study carried out a cluster analysis of the innovation system in a country with an economy in transition. In addition, the study outlined that inclusive phenomena in the economy are close to integration and are the opposite of segregation and isolation. It is noted that different institutions of integration can be used to form objective conditions for the development of babyeconomics. Public decisions of inclusion involve the use of Arrow's impossibility theorem. The research results can be used: – the individualistic functions of inclusion should be used in the formation of the babyeconomics, the human economy and the economy of nanotechnology; – states of inclusion must be created at all levels of the economic system; – a person and wealth are an individualistic aspect of an inclusive economy, because national wealth consists of individual wealth. Nanoeconomics is just beginning to be included in the systemic processes of inclusive economic phenomena, especially in countries with economies in transition

Are Federated Cloud Sharing Systems Sustainable?: On Dynamic Sharing Markets and Their Stability

The recent emergence of the small cloud (SC), both in concept and in practice, has been driven mainly by issues related to service cost and complexity of commercial cloud providers (e.g., Amazon) employing massive data centers. However, the resource inelasticity problem faced by the SCs due to their relatively scarce resources might lead to a potential degradation of customer QoS and loss of revenue. A proposed solution to this problem recommends the federated sharing of resources between competing SCs to alleviate the resource inelasticity issues that might arise. Based on this idea, a recent effort proposed SC-Share, a performance-driven static market model for competitive small cloud environments that results in an efficient market equilibrium jointly optimizing customer QoS satisfaction and SC revenue generation. However, an important question with a non-obvious answer still remains to be answered, without which SC sharing markets may not be guaranteed to sustain in the long-run - is it still possible to achieve a stable market efficient state when the supply of SC resources is dynamic in nature?. In this article, we take a first step to addressing the problem of efficient market design for single SC resource sharing in dynamic environments. We answer our previous question in the affirmative through the use of Arrow and Hurwicz's disequilibrium process in economics, and the gradient play technique in game theory that allows us to iteratively converge upon efficient and stable market equilibria.

On the Economic Sustainability of Cloud Sharing Systems Are Dynamic Single Resource Sharing Markets Stable?

The recent emergence of the small cloud (SC), both in concept and in practice, has been driven mainly by issues related to service cost and complexity of commercial cloud providers (e.g., Amazon) employing massive data centers. However, the resource inelasticity problem [29] faced by the SCs due to their relatively scarce resources might lead to a potential degradation of customer QoS and loss of revenue. A proposed solution to this problem recommends the sharing of resources between competing SCs to alleviate the resource inelasticity issues that might arise. Based on this idea, a recent e?ort ([18]) proposed SC-Share, a performance-driven static market model for competitive small cloud environments that results in an e?cient market equilibrium jointly optimizing customer QoS satisfaction and SC revenue generation. However, an important question with a non-obvious answer still remains to be answered, without which SC sharing markets may not be guaranteed to sustain in the long-run - is it still possible to achieve a stable market e?cient state when the supply of SC resources is dynamic in nature?. In this paper, we take a? rst step to addressing the problem of e?cient market design for single SC resource sharing in dynamic environments. We answer our previous question in the a?rmative through the use of Arrow and Hurwicz's disequilibrium process [9, 10] in economics, and the gradient play technique in game theory that allows us to iteratively converge upon e?cient and stable market equilibria.

Why Arrow’s theorem matters for political theory even if preference cycles never occur

Riker (Liberalism against populism, Waveland, New York, 1982) famously argued that Arrow’s impossibility theorem undermined the logical foundations of “populism”, the view that in a democracy, laws and policies ought to express “the will of the people”. In response, his critics have questioned the use of Arrow’s theorem on the grounds that not all configurations of preferences are likely to occur in practice; the critics allege, in particular, that majority preference cycles, whose possibility the theorem exploits, rarely happen. In this essay, I argue that the critics’ rejoinder to Riker misses the mark even if its factual claim about preferences is correct: Arrow’s theorem and related results threaten the populist’s principle of democratic legitimacy even if majority preference cycles never occur. In this particular context, the assumption of an unrestricted domain is justified irrespective of the preferences citizens are likely to have.

Nature and Consequences of Biological Reductionism for the Immunological Study of Infectious Diseases.

Evolution has conserved “economic” systems that perform many functions, faster or better, with less. For example, three to five leukocyte types protect from thousands of pathogens. To achieve so much with so little, biological systems combine their limited elements, creating complex structures. Yet, the prevalent research paradigm is reductionist. Focusing on infectious diseases, reductionist and non-reductionist views are here described. The literature indicates that reductionism is associated with information loss and errors, while non-reductionist operations can extract more information from the same data. When designed to capture one-to-many/many-to-one interactions—including the use of arrows that connect pairs of consecutive observations—non-reductionist (spatial–temporal) constructs eliminate data variability from all dimensions, except along one line, while arrows describe the directionality of temporal changes that occur along the line. To validate the patterns detected by non-reductionist operations, reductionist procedures are needed. Integrated (non-reductionist and reductionist) methods can (i) distinguish data subsets that differ immunologically and statistically; (ii) differentiate false-negative from -positive errors; (iii) discriminate disease stages; (iv) capture in vivo, multilevel interactions that consider the patient, the microbe, and antibiotic-mediated responses; and (v) assess dynamics. Integrated methods provide repeatable and biologically interpretable information.

APROXIMACIÓN CONCEPTUAL Y PRÁCTICA A LOS MODELOS DE ECUACIONES ESTRUCTURALES

En el presente trabajo se expone una aproximación conceptual y práctica a los Modelos de Ecuaciones Estructurales o Structural Equation Modeling (SEM). Los SEM están considerados entre las herramientas más potentes para el estudio de relaciones causales en datos no experimentales. Son una combinación del análisis factorial y la regresión múltiple y están compuestos por dos componentes: el modelo de medida y el modelo estructural. El modelo de medida describe la relación existente entre una serie de variables observables; mientras que en el modelo estructural se especifican las relaciones hipotetizadas entre las variables, es decir, se describen las relaciones entre las variables latentes mediante el uso de flechas. Llevar a cabo un SEM involucra cinco etapas: 1) Especificación del Modelo; 2) Identificación del Modelo; 3) Estimación del Modelo; 4) Evaluación del Modelo y 5) Re-especificación del Modelo. El presente artículo provee una serie de guías de “buenas prácticas” para realizar análisis SEM, con ejemplos utilizando el programa AMOS.

This Way to Produce: Strategic Use of Arrows on Grocery Floors Facilitate Produce Spending Without Increasing Shopper Budgets

This Way to Produce: Strategic Use of Arrows on Grocery Floors Facilitate Produce Spending Without Increasing Shopper Budgets

Creating Increasing Returns: The Genesis of Arrow's “Learning by Doing” Article

Kenneth J. Arrow's 1962 article “The Economic Implications of Learning by Doing” is considered a seminal contribution to endogenous growth theory. However, no history of its origins has been written yet. We aim to fill this gap by studying the genesis of Arrow's article, showing how its context of discovery conditioned its form, the concepts Arrow used and the way he defined them, and the modeling strategy he employed. We first show that Arrow's work on scale economies was part of a research project carried out with Hollis Chenery on technology and resource allocation funded by the National Science Foundation, a project that enabled Arrow to develop a theoretical and macroeconomic theory of increasing returns. We then examine the influence of John Dewey's experiential approach to education on Arrow's use of the notion of “learning by doing” and its approximation by cumulative investment. We finally study the different strategies for modeling learning developed in the 1950s and 1960s, showing the influence of RAND's and Armen Alchian's contributions on Arrow's use of a log-linear equation of learning and its introduction into an economic growth model.

The Bow and Arrow in Northern North America

There were at least four waves of bow and arrow use in northern North America. These occurred at 12000, 4500, 2400, and after about 1300 years ago. But to understand the role of the bow and arrow in the north, one must begin in the eighteenth century, when the Russians first arrived in the Aleutian Islands. At that time, the Aleut were using both the atlatl and dart and the bow and arrow (Fig. ). This is significant for two particular and important reasons. First, there are few historic cases in which both technologies were used concurrently; second, the bow and arrow in the Aleutian Islands were used almost exclusively in warfare. The atlatl was a critical technology because the bow and arrow are useless for hunting sea mammals. One cannot launch an arrow from a kayak because it is too unstable and requires that both hands remain on a paddle. To use an atlatl, it is necessary only to stabilize the kayak with a paddle on one side and launch the atlatl dart with the opposite hand. The Aleut on the Alaska Peninsula did indeed use the bow and arrow to hunt caribou there. However, in the 1,400 km of the Aleutian Islands, there are no terrestrial mammals except humans and the bow was reserved almost exclusively for conflicts among them. The most significant event in the history of the bow and arrow is not its early introduction, but rather the Asian War Complex 1300 years ago, when the recurve and backed bows first entered the region, altering regional and hemispheric political dynamics forever. [Figure: see text].

Specialty Imaging: Pain Management: Essentials of Image-guided Procedures, First Edition

Edited by Donald V. La Barage III, M.D., Lubdha M. Shah, M.D. Philadelphia, Lippincott, Williams & Wilkins, 2011. ISBN-10: 1931884196. ISBN-13: 978-1931884198. Pages: 200. Price: $139.00.In the past decade, interventional pain management has undergone tremendous growth as a result of improved understanding of the pathophysiology of various pain syndromes and advances of imaging tools to aid in their diagnosis and treatment. Specialty Imaging: Pain Management: Essentials of Image-guided Procedures , which is part of the Specialty Imaging series by Amirsys publishing, is an excellent source that depicts the most common image-guided pain management procedures performed today. The stated purpose of the book is to present pain management providers with a quick, concise reference to assist them in the evaluation of anatomic details of radiographic images of common clinical procedures and to provide a step-by-step guide to equipment preparation, procedural steps, and expected outcomes.In its first edition, Specialty Imaging: Pain Management: Essentials of Image-guided Procedures is written for medical students, residents, and fellows or clinicians involved in interventional pain management. It consists of nine sections (general principals, diagnostic techniques, skull base, cervical spine, thoracic spine, lumbar spine, vertebral body, intervertebral disc, and pelvis) presented in a bulleted text format of only 191 pages. It is specifically designed to be an effective quick reference guide to some of the key principles of the most commonly performed pain management procedures.Each chapter begins with a brief but clear outline of the anatomy of the topic to be discussed. The section is further divided into four main parts (terminology, gross anatomy, imaging anatomy, and anatomy imaging issues) that we found to be particularly interesting and useful. The accompanying text is supported by colorful, high-quality, three-dimensional volume rendering technique (3D-VRT) graphics positioned on a black backdrop that allows the anatomical illustrations to stand out. The placement of fluoroscopic radiographs adjacent to the anatomic graphics is useful when interpreting each radiograph.After each anatomy section, there are four to six common clinical procedures that are each divided into five subtitled sections labeled terminology, preprocedure, procedure, postprocedure, and outcomes. A short list of current references is also included in each section of the book. The bulleted text allows the reader to easily comprehend the systematic approach to describing the clinical entity, stressing the importance of indications and contraindications, patient positioning, equipment preparation, documentation, and issues to avoid. Consistent with the Specialty Imaging series, each clinical topic contains a “Key Facts” section summarizing and highlighting the most critical facts for each procedure. The fluoroscopic radiographs and computed tomography images presented in the procedure sections typically are high quality and demonstrate classic findings clearly and accurately.The text also includes information on procedures, such as sacral augmentation and intradiscal procedures, rarely found in recently published texts. Unfortunately, the section on piriformis syndrome includes only computed tomography images of the injection; fluoroscopy and ultrasound are not mentioned. In general, the preprocedural images in each section are an excellent addition and benefit the understanding of the postprocedural radiographs. The abundant use of arrows on the images to depict relevant anatomy is helpful.An added benefit of this book is the Amirsys eBook Advantage (Salt Lake City, UT), which comes complimentary with the purchase of the hardcover book. It offers an online version of the book with fully searchable text and images. A minor drawback is that only one view of the image is offered and no method is provided to add notations or notes.Overall, the variety and content of the image-guided procedures are appropriate and would be useful for medical students, residents, and interventional pain medicine fellows or clinicians because it provides focused examination of radiologic diagnoses, treatments, and expected outcomes of common image-guided procedures encountered by pain management clinicians. A few less common procedures, such as temporomandibular joint injections, sacroplasty, vertebral biopsy, and pubic symphysis injection, also are included, but stellate injections, superior hypogastric plexus, lumbar sympathetic, and ganglion impar injections are overlooked and would be beneficial for the reader. A limitation of the text is the lack of ultrasound-guided procedures or techniques, despite the widespread and expanding use of this imaging modality for multiple interventional pain blocks, such as lumbar facet block, cervical facet block, and stellate ganglion block. Thus, this book should not be viewed as a comprehensive pain management text, but it deserves a place in the reference collections of all interventional pain practices.

Arrows

At a glance Figures View all figures Figure 1: Arrows in scientific diagrams. (a) Well-understood conventions in molecular biology indicated by arrows. (b) Arrows are defined loosely by their geometric shapes and more definitely in context. (c) A diagram with 19 arrows used as leaders, to indicate reagent flow and to show mechanical movement. Reprinted from Nature Methods3. Full size image View in article Figure 2: Functional qualities of arrows. (a) The use of arrows versus lines as connectors suggests a certain functional relationship. (b) Alternatives to arrows as leader lines. (c) Reasonably sized arrows clearly indicate direction without being a distraction. (d) Trapped whitespace in 'open' arrowheads creates optical illusions that can attract unwanted attention. (e) Whitespace at the ends of the arrows makes them easy to discriminate from other content. (f) Orienting arrows in similar directions creates natural visual flow. Full size image View in article

Ontology of the self and material culture: Arrow-making among the Awá hunter–gatherers (Brazil)

The Awá are a group of hunter–gatherers in transition to agriculture living in the Brazilian Amazon forest. After contact with mainstream society from the 1970s onwards, their culture, and especially their material culture, has undergone important transformations. Many traditional technologies and artifacts have been lost, especially those related to women. In this context, the persistence of arrow-making, although threatened by the spread of shotguns, is remarkable. During ethnoarchaeological work conducted between 2005 and 2009, we have been able to observe that the everyday making and use of arrows cannot be explained in neither functional nor symbolic terms alone. From our observations, we conclude that making and using arrows is indissolubly woven with the self of Awá men and, for that reason, we consider that only a relational-ontological approach can help us understand the deep relationship between men and arrows. Finally, we argue that the Awá case offers new possibilities to investigate technologies of the self in other non-modern societies.

Indications of bow and stone-tipped arrow use 64 000 years ago in KwaZulu-Natal, South Africa

The invention of the bow and arrow was a pivotal moment in the human story and its earliest use is a primary quarry of the modern researcher. Since the organic parts of the weapon – wood, bone, cord and feathers – very rarely survive, the deduction that a bow and arrow was in use depends heavily on the examination of certain classes of stone artefacts and their context. Here the authors apply rigorous analytical reasoning to the task, and demonstrate that, conforming to their exacting checklist, is an early assemblage from Sibudu Cave, KwaZulu-Natal, South Africa, which therefore suggests bow and arrow technology in use there 64 millennia ago.

A Simple Wooden Ribosome Model: Helping Students Understand Transpeptidation

In teaching biology, it is critical to communicate broad concepts before considering more specific details of a process. This is particularly important when attempting to communicate the essence of transpeptidation, a key process in translation. Based on my experience in teaching general microbiology, transpeptidation is the most difficult aspect of translation for students to understand. Typically, figures given in microbiology and biochemistry texts show movement of the nascent peptide attached to the P position t-RNA to the incoming single amino acid attached to the A position amino acid-tRNA by the use of arrows, an approach that makes it difficult to understand the dynamic aspects of this process. To attempt to improve understanding of this process, tutorials also are available that emphasize decoding “messages” and the use of “Do-it-Yourself DNA Kits” where the process of transpeptidation is not specifically discussed. The simple model described in this communication provides a clear demonstration of the transpeptidation process.

A Method for Writing Open-Ended Curved Arrow Notation Questions for Multiple-Choice Exams and Electronic-Response Systems

A critical stage in the process of developing a conceptual understanding of organic chemistry is learning to use curved arrow notation. From this stems the ability to predict reaction products and mechanisms beyond the realm of memorization. Since evaluation (i.e., testing) is known to be a key driver of student learning, it follows that a new tool for evaluating student use of curved arrows could increase understanding of curved arrows. A robust assessment of this topic can be accomplished with open-ended mechanism questions; however, there are many instances where a multiple-choice format is desirable or required (e.g., exams in very large classes, standardized exams, or in-class clicker questions). Our evidence suggests that typical multiple-choice questions designed to assess curved arrow use are easy to answer even without a solid conceptual understanding of organic chemistry. This article describes a new assessment technique that allows instructors to ask open-ended questions about curved arrow no...

The role of floor control and of ontology in argumentative activities with discussion-based tools

Argumentative activity has been found beneficial for knowledge building and evaluation of information in some conditions. Many CSCL theorists have suggested that graphical representations may help in this endeavor. In the present study we examine effects of a graphical representation of synchronous discussions. 54 Grade 7 students from 2 classes participated. The study tested the effects of: (a) the use of shapes representing some argumentative functions in discussions and the use of arrows representing support/challenge between utterances; (b) the use of floor control to monitor turn taking during discussion. It appears that the combination of use of shapes and arrows and of the control over turn taking invites students to express more relevant claims and arguments, and less chat expressions.