867 research outputs found

    Econometric estimation of demand and supply curves for timber in Montana, 1962-1980

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    Underground radon gas concentrations related to earth tides

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    Over several years, radon concentrations have been recorded in a former gypsum mine near Walferdange (Luxembourg). Because of the exceptional quality of the site (thermal stability better than 0.01 7C/year, no running water, easy access, far enough from the oceans), today the mine hosts an underground laboratory for geodynamics and seismology with more than 25 permanent instruments that continuously record earth tides, earth quakes and meteorological parameters. One of the main interests in monitoring radon concentrations in this mine was to check the ability of earth tide effects on radon concentrations in the mine atmosphere. First results show that besides outside temperature and atmospheric air pressure, radon concentrations seem to be influenced by earth tides. Power spectra, calculated for different time series of radon concentrations, show the presence of both O1 (lunar declination) and M2 (principal lunar) tides. The increase in vertical extension and the decrease in gravity induced by earth tides in the bulk of the rocks may open supplementary pathways for radon and thus induce an increase of the radon transport through the rocks

    Stage‐dependent responses to emergent habitat heterogeneity: consequences for a predatory insect population in a coffee agroecosystem

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    Interactions among members of biological communities can create spatial patterns that effectively generate habitat heterogeneity for other members in the community, and this heterogeneity might be crucial for their persistence. For example, stage‐dependent vulnerability of a predatory lady beetle to aggression of the ant, Azteca instabilis, creates two habitat types that are utilized differently by the immature and adult life stages of the beetle. Due to a mutualistic association between A. instabilis and the hemipteran Coccus viridis – which is A. orbigera main prey in the area – only plants around ant nests have high C. viridis populations. Here, we report on a series of surveys at three different scales aimed at detecting how the presence and clustered distribution of ant nests affect the distribution of the different life stages of this predatory lady beetle in a coffee farm in Chiapas, Mexico. Both beetle adults and larvae were more abundant in areas with ant nests, but adults were restricted to the peripheries of highest ant activity and outside the reach of coffee bushes containing the highest densities of lady beetle larvae. The abundance of adult beetles located around trees with ants increased with the size of the ant nest clusters but the relationship is not significant for larvae. Thus, we suggest that A. orbigera undergoes an ontogenetic niche shift, not through shifting prey species, but through stage‐specific vulnerability differences against a competitor that renders areas of abundant prey populations inaccessible for adults but not for larvae. Together with evidence presented elsewhere, this study shows how an important predator is not only dependent on the existence of two qualitatively distinct habitat types, but also on the spatial distribution of these habitats. We suggest that this dependency arises due to the different responses that the predator's life stages have to this emergent spatial pattern. Interactions among members of biological communities can create spatial patterns that effectively generate habitat heterogeneity for other members in the community and this heterogeneity might be crucial for their persistence. Here we report how a voracious predatory ladybeetle in a coffee farm in Chiapas, Mexico undergoes an ontogenetic niche shift, not through shifting prey species, but through stage‐specific vulnerability differences against a competitor that renders areas of abundant prey populations inaccessible for adults but not for larvae. Our study suggests that the resulting spatial separation of resources may be crucial for the predator population persistence.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108324/1/ece31161.pd

    Mycotoxin production from fungi isolated from grapes

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    Aims: In order to assess the potential for producing mycotoxins, fungi were isolated from wine producing grapes. Methods and Results: The isolates were identified and Penicillium expansum, the most well recognized mycotoxin producer, was analysed for mycotoxin production by TLC. Many of the strains produced patulin and/or citrinin, often depending on whether they were grown on a grape or yeast extract sucrose media. Conclusions: Citrinin was produced by all strains grown in the yeast extract sucrose medium, but only one strain (from 51) was able to produce this compound in grape juice medium. Patulin was produced in the yeast extract medium by 20 strains and in grape juice medium by 33 strains. Significance and Impact of the Study: The presence of mycotoxins in wine producing grapes is discussed. Grapes contamination with patulin seems not to contribute to wine contamination, and no ochratoxin producing fungi was identified.The British Council, Conselho de Reitores das Universidades Portuguesas (CRUP) - Windsor Programme - grant no 29/00

    PAJAK BUMI DAN BANGUNAN SEBAGAI INSTRUMEN KEMASLAHATAN UMAT DALAM PERSPEKTIF EKONOMI ISLAM

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    ABSTRAK Skripsi dengan judul “Pajak Bumi Dan Bangunan sebagai Instrumen Kemaslahatan Umat dalam Perspektif Ekonomi Islam” ini ditulis oleh Hasna Jannatu Zuhriya, NIM. 2824133036, pembimbing Nur Aziz Muslim, M. HI. Penelitian ini dilatar belakangi dengan adanya dana pembiayaan pembangunan negara yang antara lain bersumber dari pajak yang salah satunya adalah Pajak Bumi dan Bangunan. Strategisnya Pajak Bumi dan Bangunan objeknya meliputi seluruh bumi dan bangunan yang berada dalam wilayah Negara Kesatuan Republik Indonesia. Melihat sejarah awal negara Islam yang dipimpin oleh Nabi Muhammad Saw, Khulafaur Rasyidin dan seterusnya dalam menjalankan roda pemerintahan memerlukan adanya pendapatan, yaitu yang bersumber dari zakat, jizyah, kharaj, ghanimah, fai’ dan lainnya yang merupakan sumber pendapatan pada masa itu. Dalam bidang ekonomi Islam, pajak dapat mencegah penumpukan harta kekayaan dan menciptakan pendistribusian kekayaan kepada masyarakat. Sehingga dapat mendukung tercapainya kemaslahatan umat. Rumusan masalah dalam penelitian ini adalah: (1) Apakah pajak dibolehkan dari sisi ekonomi Islam? (2) Apakah pajak bumi dan bangunan dibolehkan dari sisi ekonomi Islam? (3) Apakah objek pajak bumi dan bangunan sesuai dengan konsep distribusi kekayaan dalam ekonomi Islam? (4) Apakah tarif pajak bumi dan bangunan sesuai dengan prinsip kemaslahatan dalam ekonomi Islam? Tujuan dalam penelitian ini adalah: (1) mendeskripsikan apakah pajak dibolehkan dari sisi ekonomi Islam. (2) mendeskripsikan apakah pajak bumi dan bangunan dibolehkan dari sisi ekonomi Islam. (3) mendeskripsikan apakah objek pajak bumi dan bangunan sesuai dengan konsep distribusi kekayaan dalam ekonomi Islam. (4) mendeskripsikan apakah tarif pajak bumi dan bangunan sesuai dengan prinsip kemaslahatan dalam ekonomi Islam. Dalam penelitian ini menggunakan metode penelitian kepustakaan, yaitu penelitian yang data dan informasinya diperoleh dari sumber pustaka (bacaan) baik berupa buku-buku, hasil penelitian, dan bahan bacaan yang lainnya. Sumber data yang digunakan adalah sumber skunder. Dengan menggunakan metode analisis deduktif. Dari hasil penelitian ini dapat disimpulkan bahwa: (1) Dalam ekonomi Islam, pajak termasuk sistem distribusi kekayaan. (2) Dengan prinsip untuk menciptakan kemaslahatan umum, PBB boleh dikenakan pada orang yang kaya sebagaimana prinsip maslahah mursalah. (3) Objek pajak bumi dan bangunan sesuai dengan konsep distribusi kekayaan dalam ekonomi Islam. (4) Sistem tarif pajak bumi dan bangunan yang ditetapkan telah memenuhi kriteria adil (kemaslahatan) dalam ekonomi Islam. Kata kunci: Pajak, Pajak Bumi dan Bangunan, Kemaslahatan Umat, dan Ekonomi Islam

    Measurement of 222Rn dissolved in water at the Sudbury Neutrino Observatory

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    The technique used at the Sudbury Neutrino Observatory (SNO) to measure the concentration of 222Rn in water is described. Water from the SNO detector is passed through a vacuum degasser (in the light water system) or a membrane contact degasser (in the heavy water system) where dissolved gases, including radon, are liberated. The degasser is connected to a vacuum system which collects the radon on a cold trap and removes most other gases, such as water vapor and nitrogen. After roughly 0.5 tonnes of H2O or 6 tonnes of D2O have been sampled, the accumulated radon is transferred to a Lucas cell. The cell is mounted on a photomultiplier tube which detects the alpha particles from the decay of 222Rn and its daughters. The overall degassing and concentration efficiency is about 38% and the single-alpha counting efficiency is approximately 75%. The sensitivity of the radon assay system for D2O is equivalent to ~3 E(-15) g U/g water. The radon concentration in both the H2O and D2O is sufficiently low that the rate of background events from U-chain elements is a small fraction of the interaction rate of solar neutrinos by the neutral current reaction.Comment: 14 pages, 6 figures; v2 has very minor change

    Diagnostic accuracy of the vegetative and minimally conscious state: Clinical consensus versus standardized neurobehavioral assessment

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    BACKGROUND: Previously published studies have reported that up to 43% of patients with disorders of consciousness are erroneously assigned a diagnosis of vegetative state (VS). However, no recent studies have investigated the accuracy of this grave clinical diagnosis. In this study, we compared consensus-based diagnoses of VS and MCS to those based on a well-established standardized neurobehavioral rating scale, the JFK Coma Recovery Scale-Revised (CRS-R). METHODS: We prospectively followed 103 patients (55 +/- 19 years) with mixed etiologies and compared the clinical consensus diagnosis provided by the physician on the basis of the medical staff's daily observations to diagnoses derived from CRS-R assessments performed by research staff. All patients were assigned a diagnosis of 'VS', 'MCS' or 'uncertain diagnosis.' RESULTS: Of the 44 patients diagnosed with VS based on the clinical consensus of the medical team, 18 (41%) were found to be in MCS following standardized assessment with the CRS-R. In the 41 patients with a consensus diagnosis of MCS, 4 (10%) had emerged from MCS, according to the CRS-R. We also found that the majority of patients assigned an uncertain diagnosis by clinical consensus (89%) were in MCS based on CRS-R findings. CONCLUSION: Despite the importance of diagnostic accuracy, the rate of misdiagnosis of VS has not substantially changed in the past 15 years. Standardized neurobehavioral assessment is a more sensitive means of establishing differential diagnosis in patients with disorders of consciousness when compared to diagnoses determined by clinical consensus

    Understanding the threats posed by non-native species: public vs. conservation managers.

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    Public perception is a key factor influencing current conservation policy. Therefore, it is important to determine the influence of the public, end-users and scientists on the prioritisation of conservation issues and the direct implications for policy makers. Here, we assessed public attitudes and the perception of conservation managers to five non-native species in the UK, with these supplemented by those of an ecosystem user, freshwater anglers. We found that threat perception was not influenced by the volume of scientific research or by the actual threats posed by the specific non-native species. Media interest also reflected public perception and vice versa. Anglers were most concerned with perceived threats to their recreational activities but their concerns did not correspond to the greatest demonstrated ecological threat. The perception of conservation managers was an amalgamation of public and angler opinions but was mismatched to quantified ecological risks of the species. As this suggests that invasive species management in the UK is vulnerable to a knowledge gap, researchers must consider the intrinsic characteristics of their study species to determine whether raising public perception will be effective. The case study of the topmouth gudgeon Pseudorasbora parva reveals that media pressure and political debate has greater capacity to ignite policy changes and impact studies on non-native species than scientific evidence alone

    A Search for Neutrinos from the Solar hep Reaction and the Diffuse Supernova Neutrino Background with the Sudbury Neutrino Observatory

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    A search has been made for neutrinos from the hep reaction in the Sun and from the diffus
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