453 research outputs found

    THE SCOPE FOR INCREASING BIOFUEL CROP PRODUCTION IN JAPAN: AN ANALYSIS OF ALTERNATIVE POLICIES

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    ABSTRACT Contribution/ Originality This paper contributes to the literature by analyzing the impact of subsidies on biofuel production using a large data set. This paper finds that subsidies for biofuel crops will cause substantial price increases of agricultural products, largely crowding out the demand for food crops

    Understanding Factors Affecting Success of Information Security Risk Assessment: The Case of an Australian Higher Educational Institution

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    To protect information technology assets, effective risk management strategies need to be implemented. However, there is little empirical evidence on the factors that affect the successful undertaking of risk assessment. It is also not clearly known exactly how various factors affect the different stages of risk assessment and whether all factors are equally important across all stages. This research examines the experience of a large Australian university in implementing information security risk assessment and identifies a set of factors that exert considerable influence on the four stages of risk assessment initiative of the university. Finally, the implications of the findings are discussed

    Multiple paternity in superfetatious live-bearing fishes.

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    Superfetation, the ability to carry several overlapping broods at different developmental stages, has evolved independently multiple times within the live-bearing fish family Poeciliidae. Even though superfetation is widespread among poeciliids, its evolutionary advantages remain unclear. Theory predicts that superfetation should increase polyandry by increasing the probability that temporally overlapping broods are fertilized by different fathers. Here, we test this key prediction in two poeciliid species that each carry two temporally overlapping broods: Poeciliopsis retropinna and P. turrubarensis. We collected 25 females per species from freshwater streams in South-Eastern Costa Rica and assessed multiple paternity by genotyping all their embryos (420 embryos for P. retropinna; 788 embryos for P. turrubarensis) using existing and newly developed microsatellite markers. We observed a high frequency of unique sires in the simultaneous, temporally overlapping broods in P. retropinna (in 56% of the pregnant females) and P. turrubarensis (79%). We found that the mean number of sires within females was higher than the number of sires within the separate broods (2.92 sires within mothers vs. 2.36 within separate broods in P. retropinna; and 3.40 vs 2.56 in P. turrubarensis). We further observed that there were significant differences in the proportion of offspring sired by each male in 42% of pregnant female P. retropinna and 65% of female P. turrubarensis; however, this significance applied to only 9% and 46% of the individual broods in P. retropinna and P. turrubarensis, respectively, suggesting that the unequal reproductive success of sires (i.e. reproductive skew) mostly originated from differences in paternal contribution between, rather than within broods. Together, these findings tentatively suggest that superfetation may promote polyandry and reproductive skew in live-bearing fishes

    The Scope for Increasing Biofuel Crop Production in Japan: An Analysis of Alternative Policies

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    経済学 / EconomicsIn 2010, concerns regarding Japan’s excessive dependence on imports for food and energy caused the Japanese government to introduce subsidies to stimulate biofuel crop production. In this paper, we study the viability of price subsidies and certain other policies with respect to increasing the production of biofuel crops. First, we estimate the elasticity of the supply of Japanese agriculture with respect to price (inclusive of the subsidy for each unit of production). For this purpose, we use a longitudinal database of 1822 municipalities that covers all 47 prefectures of Japan. This database includes information about the production of 116 crops and their respective revenues, including subsidies. Using panel data regression techniques, we determine that although the long-run supply of certain crops is highly elastic, this supply is highly inelastic if the production of other crops is held constant. Therefore, an increase in the demand for biofuel crops will cause substantial price increases of agricultural products, largely crowding out the demand for food crops. We then discuss the viability of encouraging various agricultural practices, such as multiple cropping and the cultivation of recently abandoned land. Instead of using abandoned land, which produces a lower yield and requires abundant labor, we recommend a multiple cropping system that involves the rotation of rice and wheat. Although these measures will increase biofuel crop production to a certain extent in the short run, full-scale biofuel crop production can only take place after substantial reforms are implemented to increase the production capacity of the Japanese agricultural sector.JEL Classification Codes: Q18, Q42, Q53http://www.grips.ac.jp/list/jp/facultyinfo/leon_gonzalez_roberto

    Discovery of the first dual GSK3 beta inhibitor/Nrf2 inducer. A new multitarget therapeutic strategy for Alzheimer's disease

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    The formation of neurofibrillary tangles (NFTs), oxidative stress and neuroinflammation have emerged as key targets for the treatment of Alzheimer’s disease (AD), the most prevalent neurodegenerative disorder. These pathological hallmarks are closely related to the over-activity of the enzyme GSK3β and the downregulation of the defense pathway Nrf2-EpRE observed in AD patients. Herein, we report the synthesis and pharmacological evaluation of a new family of multitarget 2,4-dihydropyrano[2,3-c]pyrazoles as dual GSK3β inhibitors and Nrf2 inducers. These compounds are able to inhibit GSK3β and induce the Nrf2 phase II antioxidant and anti-inflammatory pathway at micromolar concentrations, showing interesting structure-activity relationships. The association of both activities has resulted in a remarkable anti-inflammatory ability with an interesting neuroprotective profile on in vitro models of neuronal death induced by oxidative stress and energy depletion and AD. Furthermore, none of the compounds exhibited in vitro neurotoxicity or hepatotoxicity and hence they had improved safety profiles compared to the known electrophilic Nrf2 inducers. In conclusion, the combination of both activities in this family of multitarget compounds confers them a notable interest for the development of lead compounds for the treatment of AD

    A mathematical model of aging-related and cortisol induced hippocampal dysfunction

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    <p>Abstract</p> <p>Background</p> <p>The hippocampus is essential for declarative memory synthesis and is a core pathological substrate for Alzheimer's disease (AD), the most common aging-related dementing disease. Acute increases in plasma cortisol are associated with transient hippocampal inhibition and retrograde amnesia, while chronic cortisol elevation is associated with hippocampal atrophy. Thus, cortisol levels could be monitored and managed in older people, to decrease their risk of AD type hippocampal dysfunction. We generated an in silico<it/>model of the chronic effects of elevated plasma cortisol on hippocampal activity and atrophy, using the systems biology mark-up language (SBML). We further challenged the model with biologically based interventions to ascertain if cortisol associated hippocampal dysfunction could be abrogated.</p> <p>Results</p> <p>The in silico<it/>SBML model reflected the in vivo<it/>aging of the hippocampus and increased plasma cortisol and negative feedback to the hypothalamic pituitary axis. Aging induced a 12% decrease in hippocampus activity (HA), increased to 30% by acute and 40% by chronic elevations in cortisol. The biological intervention attenuated the cortisol associated decrease in HA by 2% in the acute cortisol simulation and by 8% in the chronic simulation.</p> <p>Conclusion</p> <p>Both acute and chronic elevations in cortisol secretion increased aging-associated hippocampal atrophy and a loss of HA in the model. We suggest that this first SMBL model, in tandem with in vitro<it/>and in vivo<it/>studies, may provide a backbone to further frame computational cortisol and brain aging models, which may help predict aging-related brain changes in vulnerable older people.</p
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