Root System Architecture, Density, and Measurement

2000 ◽  
Author(s):  
Peter B. Tinker ◽  
Peter Nye
Keyword(s):  
Root System ◽  
Root Length Density ◽  
Practical Importance ◽  
Root Surface ◽  
Point Of View ◽  
Growth Strategy ◽  
Root Shoot Ratio ◽  
System Properties ◽  
Ground Part ◽  
The Way

The behaviour and properties of roots are central subjects in this book. A number of biochemical and physiological properties have already been described, for individual roots, in chapters 2, 5, 7, and 8. However, the macroscopic properties of root systems are of very great importance, to an extent that may not be immediately apparent from the point of view of the laboratory. These properties include the root/shoot ratio, the root system dimensions, its topological properties, and its distribution in the soil profile. The property of greatest practical importance is the way in which root length density (length per unit volume of soil) is distributed in the soil, because this defines the spatial limits to the efficiency of a root system in absorbing water and nutrients. For these reasons, we have collected material relating to root system properties here in a separate chapter. This may be particularly helpful to readers because there are very few single-part recent publications that deal with this subject. It appears logical to start with a discussion of how much root a plant possesses, its dependence upon the allocation of fixed carbon, and the efficiency with which this is used to form root tissue. Carbon is the basic currency of plants, and the way in which they distribute and use it is part of their growth strategy. The allocation of carbon in plants has been extensively researched within the above-ground part, but not the below-ground part, because of the difficult access to the root system, and the difficulty of separating the root, root surface and soil processes. It is important to understand the way in which carbon is allocated to both the root system as a whole, and then to the different parts of the root system, its symbiotic partners, exudates and other root products. Some broader issues are also relevant. Some of the carbon allocated to the root could be wasted, from the point of view of the plant or the farmer (Gregory 1994a).

La enseñanza de la ética profesional a estudiantes de derecho: análisis de caso

2018 ◽  
pp. 145
Author(s):  
Juan Pablo Beca
Keyword(s):  
Professional Ethics ◽  
Ethics Education ◽  
Teaching Experience ◽  
Point Of View ◽  
Theory And Practice ◽  
Ethics Course ◽  
Approach Theory ◽  
Competency Based ◽  
Catholic Tradition ◽  
The Way

ResumenEl trabajo analiza el curso Ética Profesional en la carrera de Derecho en la Universidad Católica de Temuco. Examina la forma como se abordaba la ética profesional antes de la creación del curso, y lo que ha ocurrido con él a través de sucesivos cambios curriculares y la introducción del modelo por competencias. El curso aporta al sello identitario, mediante un enfoque multidisciplinario. El curso ha vinculado teoría y práctica, desde que comenzó a implementarse, hasta llegar actualmente a comprenderlo en la lógica de competencias. Esta mirada implica formar a los estudiantes para resolver dilemas éticos, lo que se hace mediante la metodología del ver–juzgar–actuar. Esta metodología de discernimiento es propia de la tradicióncatólica, pero se usa en este contexto sin un cariz religioso. El método en cuestión permite ir educando la autonomía a fn de tomar decisiones. Se analiza la importancia de contextualizar la enseñanza ética y la forma como esto se ha hecho en el curso. Finalmente se aborda la relevancia de formar la conciencia ética de los estudiantes.Palabras clave: Experiencia de enseñanza – Ética profesional –Método de discernimient.ResumoO artigo analisa o curso de Ética Profssional na Escola de Direito na Universidade Católica de Temuco. Examina a forma de como abordar a ética profssional antes da criação do curso, e o que tem acontecido com ele através de sucessivas mudanças curriculares e a introdução do modelo de competências. O curso aporta ao selo de identidade, através de uma abordagem multidisciplinar. O curso tem ligado teoria e prática, desde que começou a se programar até chegar atualmente a compreendê-lo na lógica de competência. Este olhar implica formar aos estudantes para resolver dilemas éticos, o que é feito pela metodologia do ver-julgar-agir. Este método de discernimento é próprio da tradição Católica, mas é usado neste contexto, sem um aspecto religioso. O método em questão permite ir educando na autonomia com a fnalidade de tomar decisões. Analisa-se a importância de contextualizar o ensino da ética e a forma como isso tem sido feito no curso. Finalmente se aborda a relevância de formar consciência ética dos estudantes.Palavras-chave: Experiência de ensino - Ética Profssional - Método de discernimento.AbstractThis paper analyses the Professional Ethics course at the School of Law of Universidad Católica de Temuco. It reviews the way in which ethics was addressed before the course was created, and what has happened with it through the subsequent curricular changes and the implementation of a competency based model. The course contributes to the seal of identity through a multidisciplinary approach. Theory and practice have been progressively bound together since the course was introduced, to reach a point, nowadays, in which the course is understood within the logic of competencies. This point of view implies educating students for solving ethical dilemmas, which is done through the see–judge–act methodology. This discernment methodology belongs to the Roman Catholic tradition, but is used in this context without its religious complexion. This method allows educating autonomy in order to make decisions. It also analyses the importance of contextualizing ethics education and the way in which this has been done in the course. Finally, it addresses the relevance ofcreating an ethical consciousness of the students.Keywords: Teaching experience – Professional Ethics – Discernment method

scholarly journals On Kaufmann's theory of the impact of the pianoforte hammer

1920 ◽  
Vol 97 (682) ◽  
pp. 99-110 ◽  
Keyword(s):  
Initial Conditions ◽  
Practical Importance ◽  
Prima Facie ◽  
Point Of View ◽  
Infinite Length ◽  
Modes Of Vibration ◽  
Rigorous Treatment ◽  
The Subject ◽  
Set Up ◽  
The Impact

The theory of the vibrations of the pianoforte string put forward by Kaufmann in a well-known paper has figured prominently in recent discussions on the acoustics of this instrument. It proceeds on lines radically different from those adopted by Helmholtz in his classical treatment of the subject. While recognising that the elasticity of the pianoforte hammer is not a negligible factor, Kaufmann set out to simplify the mathematical analysis by ignoring its effect altogether, and treating the hammer as a particle possessing only inertia without spring. The motion of the string following the impact of the hammer is found from the initial conditions and from the functional solutions of the equation of wave-propagation on the string. On this basis he gave a rigorous treatment of two cases: (1) a particle impinging on a stretched string of infinite length, and (2) a particle impinging on the centre of a finite string, neither of which cases is of much interest from an acoustical point of view. The case of practical importance treated by him is that in which a particle impinges on the string near one end. For this case, he gave only an approximate theory from which the duration of contact, the motion of the point struck, and the form of the vibration-curves for various points of the string could be found. There can be no doubt of the importance of Kaufmann’s work, and it naturally becomes necessary to extend and revise his theory in various directions. In several respects, the theory awaits fuller development, especially as regards the harmonic analysis of the modes of vibration set up by impact, and the detailed discussion of the influence of the elasticity of the hammer and of varying velocities of impact. Apart from these points, the question arises whether the approximate method used by Kaufmann is sufficiently accurate for practical purposes, and whether it may be regarded as applicable when, as in the pianoforte, the point struck is distant one-eighth or one-ninth of the length of the string from one end. Kaufmann’s treatment is practically based on the assumption that the part of the string between the end and the point struck remains straight as long as the hammer and string remain in contact. Primâ facie , it is clear that this assumption would introduce error when the part of the string under reference is an appreciable fraction of the whole. For the effect of the impact would obviously be to excite the vibrations of this portion of the string, which continue so long as the hammer is in contact, and would also influence the mode of vibration of the string as a whole when the hammer loses contact. A mathematical theory which is not subject to this error, and which is applicable for any position of the striking point, thus seems called for.

scholarly journals Effects of Ridge Tillage and Straw Mulching on Cultivation the Fresh Faba Beans

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1054
Author(s):  
Bo Li ◽  
Xinyu Chen ◽  
Xiaoxu Shi ◽  
Jian Liu ◽  
Yafeng Wei ◽  
...  
Keyword(s):  
Rice Straw ◽  
Precision Agriculture ◽  
Field Experiments ◽  
Root Length Density ◽  
Root Surface ◽  
High Yield ◽  
Root Surface Area ◽  
Straw Mulching ◽  
Faba Beans ◽  
Ridge Tillage

Ridge tillage is an effective agronomic practice and a miniature precision agriculture; however, its effects on the growth of faba beans (Vicia faba L.) are poorly understood. This study aimed to determine the effect of ridge tillage and straw mulching on the root growth, nutrient accumulation and yield of faba beans. Field experiments were conducted during 2016 and 2017 cropping seasons and comprised four treatments: ridge tillage without any mulching (RT), flat tillage without any mulch (FT), flat tillage with rice straw mulched on the ridge tillage (FTRSM) and ridge tillage with rice straw mulched on the ridge tillage (RTRSM). The RT and RTRSM increased soil temperature and decreased soil humidity and improved soil total nitrogen, total phosphorus, available potassium and organic matter. RT and RTRSM increased the root length density, root surface area, root diameter and root activity of faba beans at flowering and harvest periods. The RT and RTRSM also increased the nitrogen, phosphorus, potassium absorption and the yield of faba beans. These results indicated that ridge tillage and straw mulching affect faba bean growth by improving soil moisture conditions and providing good air permeability and effective soil nutrition supply. This study provides a theoretical basis for the high yield cultivation improvement of faba beans.

Changes in the Use of Drugs, Tobacco, and Alcohol among Norwegian Youth from 1968 – 1979

1980 ◽  
Vol 10 (4) ◽  
pp. 405-420 ◽  
Author(s):  
Olav Irgens-Jensen ◽  
Mons George Rud
Keyword(s):  
Alcohol Consumption ◽  
Young People ◽  
Policy Making ◽  
Point Of View ◽  
The Way

In order to provide information on the way in which use of drugs - and of alcohol and tobacco -among young people changes over a period of time, the Norwegian National Institute for Alcohol Research has each spring, since 1968, conducted a survey of the youth of Oslo to determine their use of these drugs. The results are of significance not only from a scientific point of view but also from the point of view of practical policy-making. For instance, since 1974 there does not seem to have been any increase in alcohol consumption among the youth of Oslo, a fact which may reflect the measures which were introduced at that time in order to curb alcohol consumption among young people in Norway.

scholarly journals Remix in the age of ubiquitous remix

2021 ◽  
pp. 135485652199445
Author(s):  
Abby S. Waysdorf
Keyword(s):  
Point Of View ◽  
Archival Material ◽  
History Of ◽  
Accepted Part ◽  
The Media ◽  
Contemporary Media ◽  
The Aesthetic ◽  
The Way

What is remix today? No longer a controversy, no longer a buzzword, remix is both everywhere and nowhere in contemporary media. This article examines this situation, looking at what remix now means when it is, for the most part, just an accepted part of the media landscape. I argue that remix should be looked at from an ethnographic point of view, focused on how and why remixes are used. To that end, this article identifies three ways of conceptualizing remix, based on intention rather than content: the aesthetic, communicative, and conceptual forms. It explores the history of (talking about) remix, looking at the tension between seeing remix as a form of art and remix as a mode of ‘talking back’ to the media, and how those tensions can be resolved in looking at the different ways remix originated. Finally, it addresses what ubiquitous remix might mean for the way we think about archival material, and the challenges this brings for archives themselves. In this way, this article updates the study of remix for a time when remix is everywhere.

The Earliest Tool-makers

Antiquity ◽  
1956 ◽  
Vol 30 (117) ◽  
pp. 4-8 ◽  
Author(s):  
Kenneth Oakley
Keyword(s):  
Practical Importance ◽  
Point Of View ◽  
Fossil Remains

Man has been defined in many ways, as the talking animal, the religious animal, and so on, but the most satisfactory definition from the scientific point of view is probably Man the Tool-maker. One might ask, why bother to define man, considering his uniqueness and self-evident characteristics? But from the standpoint of students of evolution, particularly those concerned with the interpretation of fossil remains of early man and his possible ancestors, to define man is of practical importance.

BASIN CONFIGURATION OF A SIX-DIMENSIONAL MODEL OF AN ELECTRIC POWER SYSTEM

2002 ◽  
Vol 12 (06) ◽  
pp. 1333-1356 ◽  
Author(s):  
YOSHISUKE UEDA ◽  
HIROYUKI AMANO ◽  
RALPH H. ABRAHAM ◽  
H. BRUCE STEWART
Keyword(s):  
Power Systems ◽  
Power System ◽  
Initial Conditions ◽  
Electrical Power ◽  
Practical Importance ◽  
Intervention Strategy ◽  
Basins Of Attraction ◽  
Electric Power System ◽  
Point Of View ◽  
Electrical Power System

As part of an ongoing project on the stability of massively complex electrical power systems, we discuss the global geometric structure of contacts among the basins of attraction of a six-dimensional dynamical system. This system represents a simple model of an electrical power system involving three machines and an infinite bus. Apart from the possible occurrence of attractors representing pathological states, the contacts between the basins have a practical importance, from the point of view of the operation of a real electrical power system. With the aid of a global map of basins, one could hope to design an intervention strategy to boot the power system back into its normal state. Our method involves taking two-dimensional sections of the six-dimensional state space, and then determining the basins directly by numerical simulation from a dense grid of initial conditions. The relations among all the basins are given for a specific numerical example, that is, choosing particular values for the parameters in our model.

“La Polimigra”

2018 ◽  
Vol 42 (3) ◽  
pp. 344-366 ◽  
Author(s):  
Juan José Bustamante ◽  
Eric Gamino
Keyword(s):  
Police Officers ◽  
Legal Status ◽  
Migration Policy ◽  
Point Of View ◽  
Legal Violence ◽  
Local Police ◽  
Northwest Arkansas ◽  
Police Practices ◽  
The Way

This article examines the use of a presumption of illegality by local police officers to enforce a deportation regime in the Northwest Arkansas region. We employed an integrated racialized legal violence model to understand the way officers and immigration authorities collaborate to screen immigrants’ legal status for deportation purposes. Rather than focusing on how collaborations operate from an institutional point of view, the article provided a detailed and rich experiential description of participants’ realities shaped by the interplay of migration policy and local police practices. We concluded that the screening tactics used by local police in the cases considered in this article reflect a form of racialized legal violence intended to enforce a deportation regime against unauthorized people of Latino origin from this Arkansas area.

The effect of colour in television commercials on the comprehension and memory of the child

1987 ◽  
Vol 13 (1) ◽  
Author(s):  
L. P. Pretorius ◽  
C. J. H. Blignaut
Keyword(s):  
Point Of View ◽  
Television Commercials ◽  
Comprehension Process ◽  
Positive Effect ◽  
The Way

From a perceptual point of view it is not clear whether, and under what conditions, the presence of colour in television commercials aids the processing of information. In this study it was argued that the way in which colour is used, would have an effect on the comprehension and memory of children regarding television commercials. It was found that colour, when used in a "concrete" fashion, aids the comprehension process. The results of the study also show that the "concrete" as well as the "symbolic" use of colour have a positive effect on the memory of children for the content of television commercials. Opsomming Vanuit 'n perseptuele benadering is dit nie duidelik of, en onder watter omstandighede, die teenwoordigheid van kleur in televisie advertensies die prosessering van inligting positief bei'nvloed nie. In hierdie studie is daar van die standpunt uitgegaan dat die wyse van kleurgebruik 'n effek sal he op die begrip en geheue van kinders ten aansien van televisie advertensies. Daar is gevind dat kleur, wat op 'n "konkrete" manier gebruik word, die begripsproses bevorder. Die resultate van die studie toon ook dat sowel die "konkrete" as "simboliese" gebruik van kleur 'n positiewe effek op die geheue van kinders ten opsigte van televisie advertensie inhoud het.

Touching Photographs: Roland Barthes's ''Mistaken'' Identification

2002 ◽  
Vol 80 (1) ◽  
pp. 99-118 ◽  
Author(s):  
Margaret Olin
Keyword(s):  
Emotional Response ◽  
Point Of View ◽  
Small Child ◽  
Camera Lucida ◽  
Close Analysis ◽  
Intimate Relation ◽  
The Subject ◽  
Mistaken Identification ◽  
The Way

IN CAMERA LUCIDA, ROLAND BARTHES'S subject is the significance of photography's defining characteristic: the photograph's inseparable relation to its subject, that which ''must have been'' in front of the camera's lens. Or so it would seem. The present reading of Camera Lucida argues that Barthes's essay actually shows photography's nature as dependent not only on the intimate relation to its object, commonly termed ''indexical,'' but in accord with its relation to its user, its beholder. An examination of Barthes's encounters with photographs in Camera Lucida reveals the way in which identification and misidentification figure into the viewing of images, and suggests that contact between the beholder and the photograph actually eclipses the relation between the photograph and its subject. Barthes's focus on the emotional response of the viewer disguises the fact that he misidentified key details in Camera Lucida's photographs, most significantly in a 1927 portrait by James Van Der Zee and in the ''Winter Garden Photograph.'' This latter photograph of Barthes's recently deceased mother as a small child is famously not illustrated in the book. This essay argues that it is fictional. These ''mistakes'' suggest that Camera Lucida undermines its ostensible basis in indexicality. The subject did not have to be in front of the camera after all. The present rereading of the text from this point of view articulates a notion of performativity according to which the nature of the contact that exists between the image and the viewer informs the way an image is understood. Barthes's desire to find his mother again through her photograph to a large extent acts out his desire to re(per)form and make permanent his relation to her, a desire that he elucidates in the process of describing his search for her picture and his reaction to it when he finds it. This performative element is charged with identification; the person the narrator (Barthes) seeks, in his mother, is himself. A close analysis of the ''Winter Garden Photograph,'' as described by Barthes, shows how performances of identification are inscribed with gender and familial configurations.

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