2,963 research outputs found
Colección: Perfil #3
No full textThis board-book version of LM turns out to be quite creative. Ratoncete comes from school every afternoon and goes through the forest looking for adventures. He apparently blasts a horn into the ear of the sleeping lion. Don Leon wants to spank him as a result, but Ratoncete offers an apology, not an offer of help. Later, he happens upon the lion in his trap of ropes. 8 pages, counting both covers. 6½" x 9".Language note: SpanishNo Autho
Markets Equilibrium: The Is-Lm Model
No full text. The purpose of this study is to analyze how the concept of markets equilibrium: the IS-LM Model. This research uses library research method by using reference sources from books and journals according to the theme. The author uses a qualitative method which is explained graphically, namely the market balance of the IS-LM model where the focus is on money and goods markets associated with macroeconomics where researchers take the side of investors. The results of this study are that the balance in the economy is the point where the IS and LM curves intersect. This point provides an interest rate (r) and income level (Y) that satisfies the equilibrium conditions that occur in the goods market and money market. In other words, planned spending equals actual spending, and the demand for real money balances equals the supply. So that the IS-LM balance, it is stated that IS=LM
Auditory same/different concept learning and generalization in black-capped chickadees (Poecile atricapillus)
No full textAbstract concept learning was thought to be uniquely human, but has since been observed in many other species. Discriminating same from different is one abstract relation that has been studied frequently. In the current experiment, using operant conditioning, we tested whether black-capped chickadees (Poecile atricapillus) could discriminate sets of auditory stimuli based on whether all the sounds within a sequence were the same or different from one another. The chickadees were successful at solving this same/different relational task, and transferred their learning to same/different sequences involving novel combinations of training notes and novel notes within the range of pitches experienced during training. The chickadees showed limited transfer to pitches that was not used in training, suggesting that the processing of absolute pitch may constrain their relational performance. Our results indicate, for the first time, that black-capped chickadees readily form relational auditory same and different categories, adding to the list of perceptual, behavioural, and cognitive abilities that make this species an important comparative model for human language and cognition.Peer reviewe
<Articles>A Dynamical IS-LM Model
No full text[抄録]IS-LM モデルは、ヒックスによるケインズ経済学の因果関係を重視しながら要約したモデルと解釈することができる。IS-LM モデルの安定性分析はすでに研究成果があるが、1S-LM モデルの動学化はほとんど研究成果がない。本稿は IS-LM モデルの動学化を試みる。まず投資関数に資本ストックを取り入れ、資本蓄積と経済の変動を考える。次にカルドアモデルを考慮し、投資の予想収益率表の変化を仮定し、経済に循環が発生することを考察する。
[Abstract]In this paper, The author tries to build a Dynamical IS-LM Model. The lnvestment depends on two factors, one is the rate of interest, and the other is the rate of prosperity yield of the investment. I will focus on the second factor. As was shown by Kaldor, the rate of prosperity yield has nonlinear fluctuations. By means of this character, This study proposes an IS-LM model that generates a cycle.departmental bulletin pape
Structure and function of the oviduct in gekkonid lizards
No full textAlthough the structure of the oviduct has been analysed in several reptilian species using light microscopy, little ultrastructural information is available, particularly folloWing hormonal manipulation. Here, oviductal structure and ultrastructure from wild females, and females surgically and hormonally manipulated in the laboratory, was analysed using light (LM), scanning electron and transmission electron (TEM) microscopy in three species from the lizard family Gekkonidae: Hoplodactylus maculatus (viviparous), Saltuarius wyberba (oviparous, prodUcing a soft, parchment-like eggshell) and Hemidactylus turcicus (oviparous, producing a hard, calcareous eggshell).
The oviduct of the viviparous gecko H. maculatus exhibited seasonal changes. Maximal epithelial cell height was measured during vitellogenesis. The uterus exhibited the most obvious changes, due to the presence of a large, yolky egg following ovulation. Ultrastructural analysis identified features, such as bleb cells, apical protrusions and secretory granules, which were not visible at the LM level.
The uterus also exhibited the most distinct differences in a comparison of oviductal structure among vitellogenic females from the three gekkonid species. Viviparous H. maculatus had few uterine mucosal glands, whereas the oviparous species S. wyberba and H. turcicus had numerous glands (which secrete the eggshell membrane). The difference in gland density between the viviparous and oviparous species is consistent with other groups of reptiles in which viviparity has independently evolved. The number of secretory granules, and the staining properties of gland cells, differed between S. wyberba and H. turcicus. The differences may relate to the different types of eggshells produced by these species. Other differences among species, which could not be directly related to parity mode or eggshell type, may be related to the time period until ovulation for the individuals examined.
The literature shows that estradiol, secreted by the ovary during vitellogenesis, causes seasonal oviductal development in reptilian species; that ovariectomy, which removes the natural source of estradiol, causes oviductal regression; and that administration of estradiol to ovariectomised females causes oviductal development. The above patterns were confirmed in this study for H. turcicus. This is the first study to analyse the effects of exogenous estradiol on reptilian oviductal structure using TEM and to observe changes during the period of estradiol treatment. Changes observed included differentiation of the epithelium into ciliated and non-ciliated cells and increased numbers of secretory granules in non-ciliated cells.
Contrary to expectation, oviducts in ovariectomised H. maculatus were fully differentiated and secretory, resembling those of naturally vitellogenic females. No differences in oviduct structure at the LM and TEM level were observed among ovariectomised H. maculatus treated with vehicle solution only, estradiol, or estradiol followed by progesterone. Plasma estradiol concentrations were similar among groups. These results question the traditional view of estradiol-mediated oviductal development and suggest an extra-ovarian source of estradiol or that other hormones may maintain oviductal hypertrophy following ovariectomy in H. maculatus.
Immunocytochemistry was explored (ultimately unsuccessful) to try and determine the distribution of insulin-like growth factor-I (believed to facilitate the actions of estradiol) in the gekkonid oviduct.
Current literature and the findings of this study are incorporated into a review of oviductal structure and function in reptiles. Overall, this thesis provides comprehensive ultrastructural information including the identification of features not visible at the LM level and changes following hormonal manipulation
Structure and function of the oviduct in gekkonid lizards
No full textAlthough the structure of the oviduct has been analysed in several reptilian species using light microscopy, little ultrastructural information is available, particularly folloWing hormonal manipulation. Here, oviductal structure and ultrastructure from wild females, and females surgically and hormonally manipulated in the laboratory, was analysed using light (LM), scanning electron and transmission electron (TEM) microscopy in three species from the lizard family Gekkonidae: Hoplodactylus maculatus (viviparous), Saltuarius wyberba (oviparous, prodUcing a soft, parchment-like eggshell) and Hemidactylus turcicus (oviparous, producing a hard, calcareous eggshell).
The oviduct of the viviparous gecko H. maculatus exhibited seasonal changes. Maximal epithelial cell height was measured during vitellogenesis. The uterus exhibited the most obvious changes, due to the presence of a large, yolky egg following ovulation. Ultrastructural analysis identified features, such as bleb cells, apical protrusions and secretory granules, which were not visible at the LM level.
The uterus also exhibited the most distinct differences in a comparison of oviductal structure among vitellogenic females from the three gekkonid species. Viviparous H. maculatus had few uterine mucosal glands, whereas the oviparous species S. wyberba and H. turcicus had numerous glands (which secrete the eggshell membrane). The difference in gland density between the viviparous and oviparous species is consistent with other groups of reptiles in which viviparity has independently evolved. The number of secretory granules, and the staining properties of gland cells, differed between S. wyberba and H. turcicus. The differences may relate to the different types of eggshells produced by these species. Other differences among species, which could not be directly related to parity mode or eggshell type, may be related to the time period until ovulation for the individuals examined.
The literature shows that estradiol, secreted by the ovary during vitellogenesis, causes seasonal oviductal development in reptilian species; that ovariectomy, which removes the natural source of estradiol, causes oviductal regression; and that administration of estradiol to ovariectomised females causes oviductal development. The above patterns were confirmed in this study for H. turcicus. This is the first study to analyse the effects of exogenous estradiol on reptilian oviductal structure using TEM and to observe changes during the period of estradiol treatment. Changes observed included differentiation of the epithelium into ciliated and non-ciliated cells and increased numbers of secretory granules in non-ciliated cells.
Contrary to expectation, oviducts in ovariectomised H. maculatus were fully differentiated and secretory, resembling those of naturally vitellogenic females. No differences in oviduct structure at the LM and TEM level were observed among ovariectomised H. maculatus treated with vehicle solution only, estradiol, or estradiol followed by progesterone. Plasma estradiol concentrations were similar among groups. These results question the traditional view of estradiol-mediated oviductal development and suggest an extra-ovarian source of estradiol or that other hormones may maintain oviductal hypertrophy following ovariectomy in H. maculatus.
Immunocytochemistry was explored (ultimately unsuccessful) to try and determine the distribution of insulin-like growth factor-I (believed to facilitate the actions of estradiol) in the gekkonid oviduct.
Current literature and the findings of this study are incorporated into a review of oviductal structure and function in reptiles. Overall, this thesis provides comprehensive ultrastructural information including the identification of features not visible at the LM level and changes following hormonal manipulation
Possibilities and testing of CPRNG in block cipher mode of operation PM-DC-LM
No full textThis paper discusses the chaotic pseudo-random number generator (CPRNG), which is used in block cipher mode of operation called PM-DC-LM. PM-DC-LM is one of possible subversions of general PM mode. In this paper is not discussed the design of PM-DC-LM, but only CPRNG as a part of it because designing is written in other papers. Possibilities, how to change or to improve CPRNG are mentioned. The final part is devoted for a little testing of CPRNG and some testing data are shown. © 2016 Author(s)
Associative learning in insects : evolutionary models, mushroom bodies, and a neuroscientific conundrum
No full textEnvironmental predictability has for many years been posited to be a key variable in whether learning is expected to evolve in particular species, a claim revisited in two recent papers. However, amongst many researchers, especially neuroscientists, consensus is building for a very different view, namely that learning ability may be an emergent property of nervous systems and, thus, all animals with nervous systems should be able to learn. Here we explore these differing views, sample research on associative learning in insects, and review our own work demonstrating learning in larval antlions (Neuroptera: Myrmeleontidae), a highly unlikely insect candidate. We conclude by asserting that the capacity for associative learning is the default condition favored by neuroscientists: Whenever selection pressures favor evolution of nervous systems, the capacity for associative learning follows ipso facto. Nonetheless, to reconcile these disparate views, we suggest that (a) models for the evolution of learning may instead be models for conditions overriding behavioral plasticity; and, (b) costs of learning in insects may be, in fact, costs associated with more complex cognitive skills, skills that are just beginning to be discovered, rather than simple associative learning.Peer reviewe
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What associative learning in insects tells us about the evolution of learning and fixed behavior
No full textContemporary models for the evolution of learning suggest that environmental predictability plays a critical role in whether learning is expected to evolve in a particular species, a claim originally made over 50 years ago. However, amongst many behavioral scientists who study insect learning, as well as amongst neuroscientists who study the brain architecture of insects, a very different view is emerging, namely that all animals possessing a nervous system should be able to learn. More specifically, the capacity for associative learning may be an emergent property of nervous systems such that, whenever selection pressures favor the evolution of nervous systems, for whatever reason, the capacity for associative learning follows ipso facto. One way to reconcile these disparate views of learning is to suggest that the assumed default in these evolutionary models, namely the non-learning phenotype, is incorrect: The ability to learn is, in fact, the default but, under certain conditions, selection pressures can override that ability, resulting in hard-wired, or considerably less plastic, responses. Thus, models for the evolution of learning actually may be models for the conditions under which inherent plasticity is overridden. Moreover, what have been revealed as the costs of learning in insects may, instead, be costs associated with far more complex cognitive feats than simple associative learning – cognitive skills that researchers are just now beginning to reveal.Peer reviewe
CF/LM-PAEK: Characterisation and sensitivity to critical process parameters for automated fibre placement
No full textThis paper presents an investigation into Automated Fibre Placement process parameters for a novel carbon-fibre-reinforced thermoplastic material based on a low-melt polyaryl ether ketone polymer matrix (CF/LM-PAEK). The primary focus of this investigation is in-situ consolidation, with parameter sets for sample manufacturing selected based on a Design of Experiment method and analysed by means of mechanical and thermal testing. For in-situ consolidation, a maximum shear strength of 33.6 MPa and a crystallinity of 27.3% is achieved. Subsequent tempering increases shear strength up to 46.5 MPa and crystallinity up to 32%. The material was found to be insensitive to layup speed within the tested parameter range (1–15 m/min), achieving similar results for high layup speeds
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