7,734 research outputs found

    A Theory and Test of Credit Rationing: Comment

    Get PDF
    This article presents the authors\u27 comments on the paper A Theory and Test of Credit Rationing, by Dwight Jaffee and F. Modigliani, published in the December 1969 issue of the American Economic Review journal. One frequently encounters the casual empirical conclusion that some consumers and firms are not able to borrow as much as they would like at market rates of interest. The existence of these rejected offers to pay market rates of interest is then said to constitute credit rationing. Marshall Freimer and Myron Gordon, in addition to Jaffee and Modigliani, assume that rejected market interest rate offers exist and then attempt to explain why lenders might engage in such credit rationing. Our analysis begins by questioning the prevalent identification of credit rationing with rejected offers to pay market rates of interest. This concept of credit rationing is apparently derived by analogy with the theory of commodity markets under certainty. In that theory, any economic agent who makes an effective demand for a commodity, that is, who offers to pay its market price, is subject to nonprice commodity rationing if his demand is not supplied. The common extension of this conclusion to credit markets is that any economic agent who offers to pay the market rate of interest on some type of loan is subject to credit rationing if his demand for credit is not supplied. We argue that this concept of credit rationing is not useful because it is based on an inappropriate implicit assumption that an offer to pay the market rate of interest on a loan constitutes an effective demand for credit

    Clinicians’ perceptions of medication errors with opioids in cancer and palliative care services: a priority setting report

    Full text link
    © 2018, Springer-Verlag GmbH Germany, part of Springer Nature. This paper reports the findings of a priority setting process, undertaken with cancer and palliative care clinicians, to better understand the characteristics of medication errors with opioids within their services. Participants representing six public hospitals in one Australian state took part in a series of priority setting workshops and, drawing on actual incidents occurring in their services, sought to identify where in the opioid medication process errors were most frequently occurring. Opioid error types and perceived contributing factors were explored, and strategies to reduce/prevent opioid errors were proposed. The priority setting process provided valuable insights into the types of opioid errors that occur in cancer and palliative care services and the complexity of addressing opioid errors from the clinician’s perspective. The findings from this priority setting process will inform future targeted quality improvement initiatives to support safe opioid medication practices in cancer and palliative care services

    Unifying gauge couplings at the string scale

    Get PDF
    Using the current precision electroweak data, we look for the minimal particle content which is necessary to add to the standard model in order to have a complete unification of gauge couplings and gravity at the weakly coupled heterotic string scale. We find that the addition of a vector-like fermion at an intermediate scale and a non-standard hypercharge normalization are in general sufficient to achieve this goal at two-loop level. Requiring the extra matter scale to be below the TeV scale, it is found that the addition of three vector-like fermion doublets with a mass around 700 GeV yields a perfect string-scale unification, provided that the affine levels are (kY,k2,k3)=(13/3,1,2)(k_Y, k_2 ,k_3)=(13/3, 1, 2) , as in the SU(5)×SU(5)SU(5) \times SU(5) string-GUT. Furthermore, if supersymmetry is broken at the unification scale, the Higgs mass is predicted in the range 125 GeV - 170 GeV, depending on the precise values of the top quark mass and tan⁥ÎČ\tan \beta parameter.Comment: 11 pages, 4 eps figures, using jpconf style, talk given at CORFU2005, RTN meeting ``The Quest for Unification: Theory Confronts Experiment'', 11 - 18 September 2005, Corfu, Greec

    Expression of 72-kDa Gelatinase (MMP-2), Collagenase (MMP-1), and Tissue Metalloproteinase Inhibitor (TIMP) in Primary Pig Skin Fibroblast Cultures Derived from Radiation-Induced Skin Fibrosis

    Get PDF
    In addition to producing matrix degradation for normal tissue remodeling and repair, matrix metalloproteinases (MMPs) are also involved in various pathologic processes. MMPs and the tissue inhibitor of MMPs (TIMP) were investigated in primary cultures of pig fibroblasts from radiation-induced dermal fibrosis and compared to normal dermal fibroblasts. The free gelatinolytic, collagenolytic, and caseinolytic activities secreted into the culture medium were evaluated against specific 3H denatured collagen type I, native helical collagen, and casein α, respectively. The 72- and 68-kilodalton (kDa) forms of type IV collagenase were investigated by protease zymography and quantified by semi-automated image analysis. Transcription of the interstitial collagenase (MMP-1) and TIMP genes was studied by Northern hybridization analysis. Results revealed that in fibrotic fibroblasts, the amount of MMP-1 mRNA was greatly reduced to undetectable levels whereas the amount of TIMP mRNA was increased fourfold compared to controls. Functional assays using specific 3H substrates demonstrated an overall decrease in free MMP activities. Concomitantly, catheptic collagenolytic activity decreased in fibrotic fibroblast extracts compared to controls. These results indicate that in addition to accumulating large amounts of collagen, proteoglycans, and fibronectin, pig fibroblasts from radiation-induced dermal fibrosis also promote connective tissue matrix formation by repressing MMP-1 and stimulating TIMP expression at the transcriptional level, and by reducing overall free MMP and catheptic collagenolytic activities at the post-transcriptional level. In contrast, enzymography assays and automated image analysis demonstrated no significant change in the 72-kDa type IV collagenase activity of fibrotic pig skin fibroblasts. This opposite regulation of 72-kDa collagenase type IV to that of MMP-1 seems to indicate that it has a specific role in remodeling the extracellular matrix during wound healing, fibrogenesis, and angiogenesis

    A new experimental technique for quantifying the galvanic coupling effects on stainless steel during tribocorrosion under equilibrium conditions

    Full text link
    Galvanic coupling during tribocorrosion of passive metals at open circuit potential (OCP) generates a wear-accelerated corrosion process within the depassivated area (worn surface) that is electrically in contact with the still passive one. The galvanic coupling effect at OCP was recently modeled using an electrochemical approach allowing for the theoretical quantification of the wear-accelerated corrosion under equilibrium conditions. Despite the usefulness of this model that mathematically determines the electrochemical conditions inside the wear track in terms of anode potential via the approximation of the net anodic current density, an experimental technique allowing for their experimental determination is essential in the effort to verify the galvanic coupling models and further understand the tribocorrosion mechanisms at OCP. In the present work, a new experimental technique based on galvanic current and potential measurements through a Zero-Resistance Ammeter (ZRA) for quantifying the electrode potential and anodic current inside the wear track during rubbing at OCP has been assessed. This experimental set-up has allowed for the first time to determine the prevailing electrochemical conditions (electrode potential and anodic current) inside the wear track by solely exposing the wear track to the electrolyte and physically separating the cathode from the anode (wear track). The effects of sliding wear at open circuit potential have been investigated for a super duplex stainless steel (UNS S32750) in 3.4 wt% NaCl. The new experimental set-up proposed in this work separates the cathode from the anode and exposes solely the wear track to the electrolyte. Using well-established electrochemical theories, the effect of the extent of the galvanic coupling on wear at the open circuit potential conditions has been quantified.The authors would like to thank the support from the European Union for funding C. Torres through the Leonardo da Vinci Mobility program. C.B. von der Ohe and E. Jensen are also acknowledged for having taken part in the initial phase 1151 of this long project. Dr. N. Papageorgiou (NTNU) is also acknowledged for the input and calculations in the modeling part and for preparing Figs. 6-9 of the paper.Espallargas Álvarez, N.; Johnsen, R.; Torres, C.; Igual Muñoz, AN. (2013). A new experimental technique for quantifying the galvanic coupling effects on stainless steel during tribocorrosion under equilibrium conditions. Wear. 307(1-2):190-197. doi:10.1016/j.wear.2013.08.026S1901973071-

    Epigenetic and phenotypic variability in populaitons of Schistosoma mansoni - a possible kick-off for adaptative host/parasite evolution

    Get PDF
    International audienceEpigenetics, the science of heritable but modifiable information, is now a well-accepted component of many research fields. Nevertheless, epigenetics has not yet found broad appreciation in one of the most exciting fields of biology: the comprehension of evolution. This is surprising, since the reason for the existence of this alternative information-transmitting system lies certainly in the evolutionary advantage it provides. Theoretical considerations support a model in which epigenetic mechanisms allow for increasing phenotypic variability and permit populations to explore the adaptive landscape without modifications of the genotype. The data presented here support the view that modulating the epigenotype of the human bloodfluke Schistosoma mansoni by treatment of larvae with histone deacetylase inhibitor leads indeed to an increase of phenotypic variability. It is therefore conceivable that environmentally induced changes in the epigenotype release new phenotypes on which selection can act and that this process is the first step in adaptive evolution
    • 

    corecore