6,597 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
A large mid-Holocene estuary was not present in the lower River Murray, Australia
No full textRecent research has suggested that during the mid-Holocene (c. 8500 to 5000 cal yr BP) a large estuary occupied the lower River Murray and its terminal lakes (Lakes Alexandrina and Albert: herein the Lower Lakes) in South Australia. This research has questioned both reconstructions of past River Murray discharge and contemporary environmental water provisions aimed at maintaining the freshwater state of the Lower Lakes. We show that (1) a large mid-Holocene estuary extending into the lower River Murray was not physically possible, and (2) that the River Murray and Lower Lakes were predominantly fresh during the mid-Holocene. Sea level was well below present at the time of purported initiation of estuarine sedimentation and, therefore, could not have allowed formation of an estuary. Holocene human occupation of the lower River Murray valley, that was reliant on freshwater resources, negates the existence of a large estuary in the valley. A variety of freshwater indicators in sediments from in, and around, the Lower Lakes negate the notion of significant marine incursion. Hence, current management of the Lower Lakes as freshwater ecosystems is consistent with their Holocene history.J. Tibby, B. Bourman, C. Wilson, L. M. Mosley, A. P. Belperio, D. D. Ryan ... et al
Field trial and modelling of different strategies for remediation of soil salinity and sodicity in the Lower Murray irrigation areas
No full text
Rising saline groundwatertables and drought in the Lower Murray Reclaimed Irrigation Area (LMRIA) has created soil salinity and sodicity conditions, which has resulted in a decline in agricultural production. A 2 month field experiment was conducted at Mobilong irrigation area using a randomised block design with trial plots (4m2) in each of the three blocks containing the following six treatments: (1) control (not irrigated), (2) irrigation (River Murray water) only, (3) gypsum application (1.5 kg/m2) and irrigation, (4) limestone application (1.5 kg/m2) and irrigation, (5) seawater (source of dissolved Ca2+) application (100mm depth) and irrigation and (6) acid (pH 3) drainage (to dissolve CaCO3 in soil to release Ca2+) application (100mm irrigation water depth) and irrigation. Soil electrical conductivity (EC), pH, exchangeable cations (Ca2+, Mg2+, Na+, K+), exchangeable sodium percentage (ESP) and saturated hydraulic conductivity were measured. The decrease in EC was greatest in the irrigation only treatment followed by the gypsum and limestone treatments. At the end of the trial, the EC in the irrigation only treatment was about one-quarter of the control, in which the EC increased. The seawater and acid drainage treatments reduced the soil EC relative to the control but the EC was 2–3dS/m higher than the irrigation, gypsum and limestone treatments at the end of the trial. The gypsum, irrigation only and limestone treatments approximately doubled the exchangeable Ca relative to the control and exchangeable Na was reduced. Unsaturated water and solute transport model (HYDRUS-UNSATCHEM) simulations were able to represent the general trends in the field results. The results suggest that only River Murray water irrigation and drainage could be effective for the management of soil salinity and sodicity in the LMRIA but further research is required to establish the threshold electrolyte concentration to prevent soil dispersion.
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Influence of hosts on the ecology of arboviral transmission: Potential mechanisms influencing dengue, Murray Valley encephalitis, and Ross River virus in Australia
No full textEcological interactions are fundamental to the transmission of infectious disease. Arboviruses are particularly elegant examples, where rich arrays of mechanisms influence transmission between vectors and hosts. Research on host contributions to the ecology of arboviral diseases has been undertaken within multiple subdisciplines, but significant gaps in knowledge remain and multidisciplinary approaches are needed. Through our multidisciplinary review of the literature we have identified five broad areas where hosts may influence the ecology of arboviral transmission: host immunity; cross-protective immunity and antibody-dependent enhancement; host abundance; host diversity; and pathogen spillover and dispersal. Herein we discuss the known and theoretical roles of hosts within these topics and then apply this knowledge to three epidemiologically important mosquito-borne arboviruses that occur in Australia: dengue virus (DENV), Murray Valley encephalitis virus (MVEV), and Ross River virus (RRV). We argue that the underlying mechanisms by which hosts influence arboviral activity are numerous and attempts to delineate these mechanisms further are needed. Investigations that focus on hosts of vector-borne diseases are likely to be rewarding, particularly where the ecology of vectors is relatively well understood. From an applied perspective, enhanced knowledge of host influences upon vector-borne disease transmission is likely to enable better management of disease burden. Finally, we suggest a framework that may be useful to identify and determine host contributions to the ecology of arboviruses
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
Why does brain damage impair memory? A connectionist model of object recognition memory in perirhinal cortex
No full textObject recognition is the canonical test of declarative memory, the type of memory putatively impaired after damage to the temporal lobes. Studies of object recognition memory have helped elucidate the anatomical structures involved in declarative memory, indicating a critical role for perirhinal cortex. We offer a mechanistic account of the effects of perirhinal cortex damage on object recognition memory, based on the assumption that perirhinal cortex stores representations of the conjunctions of visual features possessed by complex objects. Such representations are proposed to play an important role in memory when it is difficult to solve a task using representations of only individual visual features of stimuli, thought to be stored in regions of the ventral visual stream caudal to perirhinal cortex. The account is instantiated in a connectionist model, in which development of object representations with visual experience provides a mechanism for judgment of previous occurrence. We present simulations addressing the following empirical findings: (1) that impairments after damage to perirhinal cortex (modeled by removing the perirhinal cortex layer of the network) are exacerbated by lengthening the delay between presentation of to-be-remembered itemsandtest, (2) that such impairments are also exacerbated by lengthening the list of to-be-remembered items, and (3) that impairments are revealed only when stimuli are trial unique rather than repeatedly presented. This study shows that it may be possible to account for object recognition impairments after damage to perirhinal cortex within a hierarchical, representational framework, in which complex conjunctive representations in perirhinal cortex play a critical role
Perceptual functions of perirhinal cortex in rats: zero-delay object recognition and simultaneous oddity discriminations
No full textThe perirhinal cortex (PRh) is widely accepted as having an important role in object recognition memory in humans and animals. Contrary to claims that PRh mediates declarative memory exclusively, previous evidence suggests that PRh has a role in the perceptual processing of complex objects. In the present study, we conducted an examination of the possible role of PRh in perceptual function in rats.Weexamined whether bilateral excitotoxic lesions ofPRhorPPRh(perirhinal plus postrhinal cortices) in the rat would cause deficits in a zero-delay object-recognition task and a simultaneous oddity discrimination task. Both of these tasks measured spontaneous (untrained, unrewarded) behavior, and the stimuli in these experiments were manipulated to produce varying levels of perceptual difficulty. As predicted by simulations using a computational model, rats with PPRh lesions were impaired in object recognition when the stimuli to be discriminated were manipulated to share many features in common. Furthermore, rats with PPRh and PRh lesions were impaired in a simultaneous oddity discrimination task when the stimuli to be discriminated were manipulated explicitly to be more perceptually similar. These findings provide support for the idea that PRh in the rat is important for the perceptual processing of complex objects, in addition to its well established role in memory
<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
LM-OSL signals from some insulators: an analysis of the dependency of the detrapping probability on stimulation light intensity
No full textOptically stimulated luminescence (OSL) signals from various insulators including quartz, Al2O3 : C, BeO and NaCl have been studied using the linear modulation OSL (LM-OSL) technique. LM-OSL is based on the linear increase of the stimulation light power from zero to a maximum during the measurement. The resultant OSL curve initially increases and then decays after reaching a maximum, The analysis of LM-OSL data usually assumes a linear relationship between the detrapping rate and the stimulation light intensity. However, experiments carried out using various insulators have shown that this assumption is not always correct. The initial decay rates of the blue (similar to 470 nm) light stimulated constant power OSL decay curves were examined to test the relation between the detrapping rates and the stimulation light intensity. In SiO2, Al2O3 : C and BeO a linear relation between the detrapping rates and the stimulation light intensity was observed. However the detrapping rate of the OSL signal from NaCl was non-linear. Assuming that this non-linearity can be described using a saturating exponential function, a new more general expression for the LM-OSL signal has been derived. The validity of this expression was checked using curve fitting and it was found that the new expression could describe the LM-OSL curves successfully. (C) 2001 Elsevier Science Ltd. All rights reserved
Is there a Natural Rate of Crime?
No full textStudies in the economics of crime literature have reached mixed conclusions on the deterrence hypothesis. One explanation which has been offered for the failure to find evidence of a deterrent effect in the long run is the natural rate of crime. This paper applies the univariate Lagrange Multiplier (LM) unit root test with one and two structural breaks to crime series for the United Kingdom and United States and the panel LM unit root test with and without a structural break to crime rates for a panel of G7 countries to examine whether there is a natural rate of crime. Our main finding is that when we allow for two structural breaks in the LM unit root test and a structural break in the panel data unit root test, there is strong evidence of a natural rate of crime. The policy implications of our findings is that governments should focus on altering the economic and social structural profile which determines crime in the long run rather than increasing expenditure on law enforcement which will at best reduce crime rates in the short run.Natural rate of crime; Deterrence hypothesis; unit root.
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