Experiments on the relative abundance of two sibling species of grain weevils.

1954 ◽  
Vol 2 (1) ◽  
pp. 66 ◽  
Author(s):  
LC Birch
Keyword(s):  
Relative Abundance ◽  
Sibling Species ◽  
Large Strain ◽  
Small Strain ◽  
The Other ◽  
Stored Grain ◽  
Stored Wheat ◽  
Innate Capacity ◽  
Series Of Experiments ◽  
Capacity For Increase

The small "strain" and the large "strain" of Calandra oryzae L. are sibling species. The small "strain" is common in stored wheat and rare in stored maize. The reverse is true for the large "strain." A series of four experiments showed how wheat favoured the small "strain" and how maize favoured the large "strain." Given a choice of wheat and maize the small "strain" and the large "strain" laid most of their eggs in wheat but the proportion was larger for the small "strain" as compared with the large "strain." When the insects were reared for several generations in wheat they laid more of their eggs in wheat. Likewise when reared in maize they laid more of their eggs in maize. But this "host conditioning" was not sufficient to prevent them from laying many eggs in the "wrong" grain. The innate capacity for increase of the small "strain" was greater than that of the large "strain" in wheat but in maize the large "strain" had a greater innate capacity for increase than the small "strain." In crowded cultures wheat again favoured the small "strain" by permitting greater maximum populations as compared with the large "strain." Maize favoured the large "strain" in this respect. When the two "strains" occurred together in crowded cultures one always drove the other out. The small "strain" was the successful one in wheat and the large "strain" was the successful one in maize. Although these four series of experiments illustrate ways in which wheat favours the small "strain" and maize favours the large "strain" they do not, in themselves alone, account for the segregation of the two "strains" in stored grain.

scholarly journals Elastic Properties of Magnetorheological Elastomers in a Heterogeneous Uniaxial Magnetic Field

2018 ◽  
Vol 19 (10) ◽  
pp. 3045 ◽  
Author(s):  
Takehito Kikuchi ◽  
Yusuke Kobayashi ◽  
Mika Kawai ◽  
Tetsu Mitsumata
Keyword(s):  
Magnetic Field ◽  
Elastic Properties ◽  
Uniform Magnetic Field ◽  
Large Strain ◽  
Small Strain ◽  
Experimental Results ◽  
The Other ◽  
Magnetorheological Elastomers ◽  
Other Hand ◽  
Strain Model

Magnetorheological elastomers (MREs) are stimulus-responsive soft materials that consist of polymeric matrices and magnetic particles. In this study, large-strain response of MREs with 5 vol % of carbonyl iron (CI) particles is experimentally characterized for two different conditions: (1) shear deformation in a uniform magnetic field; and (2), compression in a heterogeneous uniaxial magnetic field. For condition (1), dynamic viscoelastic measurements were performed using a rheometer with a rotor disc and an electric magnet that generated a uniform magnetic field on disc-like material samples. For condition (2), on the other hand, three permanent magnets with different surface flux densities were used to generate a heterogeneous uniaxial magnetic field under cylindrical material samples. The experimental results were mathematically modeled, and the relationship between them was investigated. We also used finite-element method (FEM) software to estimate the uniaxial distributions of the magnetic field in the analyzed MREs for condition (2), and developed mathematical models to describe these phenomena. By using these practicable techniques, we established a simple macroscale model of the elastic properties of MREs under simple compression. We estimated the elastic properties of MREs in the small-strain regime (neo–Hookean model) and in the large-strain regime (Mooney–Rivlin model). The small-strain model explains the experimental results for strains under 5%. On the other hand, the large-strain model explains the experimental results for strains above 10%.

The Rutherford Memorial Lecture, 1971: Evolution of the elements

1972 ◽  
Vol 329 (1576) ◽  
pp. 1-16 ◽  
Keyword(s):  
Relative Abundance ◽  
Chemical Elements ◽  
The Other ◽  
Memorial Lecture ◽  
Ernest Rutherford ◽  
Γ Radiation ◽  
Naturally Occurring ◽  
The Earth ◽  
Series Of Experiments ◽  
Volatile Materials

I chose this title because, as your Chairman has emphasized, this is a historic occasion. More than 50 years ago Ernest Rutherford used this title when he returned to New Zealand in 1914 and lectured here, in Canterbury College. On that occasion he talked about the spontaneous disintegrations that radioactive nuclei undergo, with the emission of α, β and γ radiation; how one radioactive element changes into another and how uranium and thorium eventually transform to various isotopes of lead. The understanding of the laws of radioactive change was the result of collaboration between Rutherford & Soddy in a long series of experiments at McGill; this was the first of three of Rutherford’s most important results-the other two were: ‘the discovery of the nucleus of the atom following experiments of Geiger & Marsden at Manchester’ and ‘the detection of nuclear interactions’. Under the same title as used by Rutherford here in 1914 I want tonight to talk about how the chemical elements of which the Earth and Sun are made, may have evolved. As a start I would like to present to you in figure 1 some of the facts that need explaining — the relative abundance of the 300 or so naturally occurring types of atom — the isotopes of the various chemical elements. Their relative abundance tells us something about how the elements must have evolved. The graph displayed shows the results appropriate to the Solar System. One realizes that terrestrial or meteoritic abundances are seriously distorted by loss of volatile materials - but most of one’s data is collected from the Earth and meteorites, so we have to put up with it. The distribution, corrected as well as possible for the loss of volatile materials, is often called the ‘universal’ abundance for the elements, but this is overstating its significance.

Adaptations to temperature in geographic races of the Queensland fruit fly Dacus (Strumenta) tryoni

1967 ◽  
Vol 15 (6) ◽  
pp. 1141 ◽  
Author(s):  
MA Bateman
Keyword(s):  
Survival Rate ◽  
East Coast ◽  
Survival Rates ◽  
Fruit Fly ◽  
Intermediate Temperature ◽  
The Other ◽  
Immature Stages ◽  
Innate Capacity ◽  
Different Temperatures ◽  
Capacity For Increase

Four populations of Dacus tryoni collected from widely separated regions on the east coast of Australia (Cairns, Brisbane, Sydney, and East Gippsland) were compared in the laboratory to determine how they differed in their adaptations to temperature, and what adaptations have enabled the species to spread into colder areas. The main criteria used for the comparisons were the innate capacity for increase (rm) and its components : speed of development, survival rate, and fecundity. The races were compared at three different temperatures and in two successive years. Differences between the races from Cairns, Brisbane, and Sydney were often large and consistent, and in general they correlated well with differences in the climates of the respective geographic areas. At the lowest temperature the Sydney strain had the highest (rm), while the Cairns strain had the lowest. At the intermediate temperature there were no significant differences between the strains. At the highest temperature the Cairns strain had the highest (rm), while the Sydney strain had the lowest. The strain from East Gippsland behaved in an unpredictable way in most of the experiments, and rarely fitted into the trends set by the other three strains. The major differences appear to have been due primarily to adaptations affecting fecundity. There were also significant differences in the longevity of adults and the survival rates of immature stages, but not in speeds of development. The differences in fecundity may have been related to differences in the proportions of females fertilized in the experimental cages.

scholarly journals Neural Modeling of the Distribution of Protein, Water and Gluten in Wheat Grains during Storage

2020 ◽  
Vol 12 (12) ◽  
pp. 5050
Author(s):  
Katarzyna Szwedziak ◽  
Ewa Polańczyk ◽  
Żaneta Grzywacz ◽  
Gniewko Niedbała ◽  
Wiktoria Wojtkiewicz
Keyword(s):  
Total Protein ◽  
Near Infrared ◽  
Linear Regression Analysis ◽  
Multiple Linear Regression Analysis ◽  
Quality Parameters ◽  
Neural Modeling ◽  
Infrared Spectrometry ◽  
Stored Grain ◽  
Stored Wheat

An important requirement in the grain industry is to obtain fast information on the quality of purchased and stored grain. Therefore, it is of great importance to search for innovative solutions aimed at the monitoring and fast assessment of quality parameters of stored wheat The results of the evaluation of total protein, water and gluten content by means of near infrared spectrometry are presented in the paper. Multiple linear regression analysis (MLR) and neural modeling were used to analyze the obtained results. The results obtained show no significant changes in total protein (13.13 ± 0.15), water (10.63 ± 0.16) or gluten (30.56 ± 0.54) content during storage. On the basis of the collected data, a model artificial neural network (ANN) MLP 52-6-3 was created, which, with the use of four independent features, allows us to determine changes in the content of water, protein and gluten in stored wheat. The chosen network returned good error values: learning, below 0.001; testing, 0.015; and validation, 0.008. The obtained results and their interpretation are an important element in the warehouse industry. The information obtained in this way about the state of the quality of stored grain will allow for a fast reaction in case of the threat of lowering the quality parameters of the stored grain.

The Further Exploration of Applying Small-Strain and Large-Strain Formulations to SMA

2012 ◽  
Vol 529 ◽  
pp. 228-235
Author(s):  
Jie Yao ◽  
Yong Hong Zhu
Keyword(s):  
Phase Transformation ◽  
Constitutive Model ◽  
Uniaxial Tension ◽  
Driving Force ◽  
Research Team ◽  
Large Strain ◽  
Small Deformation ◽  
Small Strain ◽  
Proportional Loading ◽  
The Difference

Recently, our research team has been considering to applying shape memory alloys (SMA) constitutive model to analyze the large and small deformation about the SMA materials because of the thermo-dynamics and phase transformation driving force. Accordingly, our team use simulations method to illustrate the characteristics of the model in large strain deformation and small strain deformation when different loading, uniaxial tension, and shear conditions involve in the situations. Furthermore, the simulation result unveils that the difference is nuance concerning the two method based on the uniaxial tension case, while the large deformation and the small deformation results have huge difference based on shear deformation case. This research gives the way to the further research about the constitutive model of SMA, especially in the multitiaxial non-proportional loading aspects.

scholarly journals VIII. On the descending degenerations which follow lesions of the gyrus marginalis and gyrus fornicatus in monkeys

1889 ◽  
Vol 180 ◽  
pp. 331-354
Keyword(s):  
The Other ◽  
Post Mortem ◽  
Cerebral Lesions ◽  
Series Of Experiments ◽  
The Government ◽  
Government Grant

The following paper contains the record of an investigation into the degenerations which follow lesions of the gyrus marginalis and gyrus fornicatus in Monkeys. The work has been carried on under my direction by Mr. France, with the aid of a grant from the Government Grant Fund, and represents part of a long investigation into the degenerations which follow artificially produced cerebral lesions, the material for which has been furnished by cases operated upon in conjunction respectively with Professor V. Horsley and Dr. Sanger Brown. These cases and the physiological results of the operations have already been published in the ‘Philosophical Transactions.’ The experiments here dealt with, twelve in number, comprise only the lesions of the gyrus marginalis and gyrus fornicatus, and, with one exception (case 12), are taken from the series of experiments performed in conjunction with Mr. Horsley. Of the twelve cases, six were of removal, or attempted removal, of the gyrus marginalis, and six of removal, or attempted removal, of the gyrus fornicatus. But in only one or two instances was the lesion, as determined by post-mortem examination, exactly limited to the convolution which it was attempted to remove, for in most cases the adjacent gyrus was to a certain extent involved in the injury. This was especially the case when removal of the gyrus fornicatus had been attempted, on account of its deep situation, and the difficulty of getting at it without some manipulation of the superjacent gyrus. Nevertheless, the removal of one or the other gyrus was sufficiently complete in all the cases here selected to produce characteristic symptoms and characteristic descending degenerations.

A Zebrafish Embryo Behaves both as a “Cortical Shell – Liquid Core” Structure and a Homogeneous Solid when Experiencing Mechanical Forces

2014 ◽  
Vol 20 (6) ◽  
pp. 1841-1847 ◽  
Author(s):  
Fei Liu ◽  
Dan Wu ◽  
Ken Chen
Keyword(s):  
Mechanical Properties ◽  
Mechanical Behavior ◽  
Zebrafish Embryo ◽  
Large Strain ◽  
Liquid Core ◽  
Small Strain ◽  
Core Structure ◽  
Mechanical Forces ◽  
Cortical Shell ◽  
A Cell

AbstractMechanical properties are vital for living cells, and various models have been developed to study the mechanical behavior of cells. However, there is debate regarding whether a cell behaves more similarly to a “cortical shell – liquid core” structure (membrane-like) or a homogeneous solid (cytoskeleton-like) when experiencing stress by mechanical forces. Unlike most experimental methods, which concern the small-strain deformation of a cell, we focused on the mechanical behavior of a cell undergoing small to large strain by conducting microinjection experiments on zebrafish embryo cells. The power law with order of 1.5 between the injection force and the injection distance indicates that the cell behaves as a homogenous solid at small-strain deformation. The linear relation between the rupture force and the microinjector radius suggests that the embryo behaves as membrane-like when subjected to large-strain deformation. We also discuss the possible reasons causing the debate by analyzing the mechanical properties of F-actin filaments.

Speciation of cestoda. Evidence for two sibling species in the complex Bothrimonus nylandicus (Schneider 1902) (Cestoda: Cyathocephalidea)

Parasitology ◽  
1988 ◽  
Vol 97 (1) ◽  
pp. 139-147 ◽  
Author(s):  
F. Renaud ◽  
C. Gabrion
Keyword(s):  
Sibling Species ◽  
Definitive Host ◽  
Parasite Species ◽  
Adult Stage ◽  
Life Cycles ◽  
The Other ◽  
Congeneric Species ◽  
Biochemical Genetic ◽  
Autumn And Winter ◽  
Biological Differences

SUMMARYUsing biochemical genetic methods, we have distinguished 2 sibling species in the complex Bothrimonus nylandicus (Schneider, 1902), which infest 2 congeneric species of sole (Solea lascaris and Solea impar) on European coasts (Atlantic and Mediterranean). Neither of the parasite species is specific for either of the sole species, but one of them is present all year round, whereas the other is absent in the autumn and winter and only appears in the spring, subsequently disappearing at the end of the summer. Only S. impar lives in the Mediterranean, and is equally infested by both cestodes, whereas both species occur in the Atlantic and each of them is preferentially infested by 1 species of cestode. The shortness of the adult stage of the parasite in the definitive host and the presence of 2 life-cycles associated with competition between the 2 hosts in the Atlantic could be responsible for the biological differences observed and for maintaining the sibling species in sympatry.

Studies on rates of development and reproduction of California red scale, Aonidiella aurantii (Mask.) (Homoptera : Diaspididae) on citrus

1972 ◽  
Vol 20 (1) ◽  
pp. 37 ◽  
Author(s):  
JR Willard
Keyword(s):  
Leaf Disk ◽  
Distilled Water ◽  
Aonidiella Aurantii ◽  
Innate Capacity ◽  
Disk Method ◽  
Capacity For Increase

Red scale were reared in the laboratory on disks cut from lemon leaves floated on distilled water in plastic vials. Scales could be reared to maturity on the disks and females would produce crawlers. Rates of development measured at four temperatures using the leaf disk method were similar to data reported by earlier authors. Unfertilized females were found to remain alive and could be fertilized up to 16 weeks after the second moult. On the average, the longevity of unfertilized females was shown to be 3.5 weeks longer than that of fertilized females. The fecundity of females collected from the field was measured at a series of constant temperatures. Estimates of the capacity for increase (rc) and the innate capacity for increase (rm were obtained at four temperatures. Both these statistics were shown to be greatly influenced by temperature; rc was found to be an underestimate of rm at higher temperatures.

scholarly journals XXI. On the construction of a new calorimeter for determining the radiating powers of surfaces in air; and its application to the surfaces of various mineral substances

1860 ◽  
Vol 150 ◽  
pp. 379-408
Keyword(s):  
Surrounding Medium ◽  
The Other ◽  
Absolute Amount ◽  
Present Communication ◽  
Atmospheric Air ◽  
Glass Bulb ◽  
Heated Body ◽  
Series Of Experiments ◽  
Quantity Of Heat ◽  
Limited Induction

When my paper on the Conductivity of various Substances was presented to the Society, it was intimated to me on the part of the Council of the Society, that it might be advisable to determine absolute instead of relative conductivities, the latter being alone attempted in my previous experiments. It has been partly in consequence of this intimation, as well as from the desire to make my investigations the more complete, that I have given my attention to the construction of a calorimeter which might serve for this purpose. The present communication contains a description of this instrument, with the results which it has enabled me to obtain respecting the absolute quantities of heat which emanate from the surfaces of certain substances under given conditions. 1. When a body is placed in atmospheric air (or any gas), the quantity of heat which is lost from its surface in a given time, when its temperature is higher than that of the surrounding medium, will be greater than if it were placed in a vacuum, other conditions remaining unaltered. In the latter case the heat escapes by simple radiation; in the other case a portion of the heat also escapes in consequence of the contact of the air with the surface of the heated body. Dulong and Petit ascertained by a careful series of experiments, the laws according to which the mercury contained in the bulb of a thermometer cools, or those which govern the quantity of heat which escapes from the surface of the containing bulb, when placed in a vacuum, in air, or in several kinds of gases. These experiments were made with the glass bulb naked, and also when it was silvered, so that the laws of radiation which they established were strictly in reference only to surfaces of glass and those of silver. Certain laws were identical in both these cases, and hence it was concluded, though by a limited induction, that the same laws were applicable to all other surfaces. They did not, however, give the absolute quantity of heat which, under given circumstances, and in a given time, emanates from the surfaces of the glass or silver with which they experimented. The instrument which I have constructed gives very easily this absolute amount of heat, as I believe, with very approximate accuracy.

Sign in / Sign up

Export Citation Format

Share Document