The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform
Linsy R Farris - One of the best experts on this subject based on the ideXlab platform.
-
tear osmolarity a new Gold Standard
Advances in Experimental Medicine and Biology, 1994Co-Authors: Linsy R FarrisAbstract:The purpose of this presentation is to propose tear osmolality measurement as a new Gold Standard for the diagnosis of keratoconjunctivitis sicca. Agreement on the diagnostic criteria is needed in order to permit meaningful comparisons of scientific results obtained from varying patient populations. The method employed is a review of previous studies of clinical symptoms, signs and diagnostic tests employed in making a diagnosis of keratoconjunctivitis sicca. Data from previous studies are reviewed and the results of individual and combinations tests are compared in regard to sensitivity, specificity and overall efficiency in establishing accurate diagnoses. The results are that the measurement of tear osmolality measurement provides the greatest sensitivity, specificity and overall efficiency of a single test. Adding either the Schirmer test without anesthetic or tear lactoferrin measured by the Lactoplate™ method in parallel to tear osmolality measurement did not increase the sensitivity of diagnotic testing beyond 90% which was obtained by using tear osmolality measurement alone. The specificity of such combination diagnostic testing was increased only from 95% to 100%. The simplicity of tear osmolarity measurement and its established reliability supports the conclusion that this test is a reasonable candidate for a new international Gold Standard in the diagnosis of keratoconjunctivitis sicca.
Michael D. Bordo - One of the best experts on this subject based on the ideXlab platform.
-
The Gold Standard and Related Regimes
1999Co-Authors: Michael D. BordoAbstract:This book contains a collection of Michael D. Bordo's essays, written singly and with colleagues, on the classical Gold Standard and related regimes based directly or indirectly on Gold convertibility. The Gold Standard (and its variants) was the basis for both international and domestic monetary arrangements from the third quarter of the nineteenth century until 1971 when President Nixon closed the US Gold window, effectively ending the Bretton Woods International Monetary System. Although the Gold Standard and its variants are now history, it still has great appeal for policymakers and scholars. Several desirable features of the Gold Standard have resources for the ongoing issue of international monetary reform. They include its record as a stable nominal anchor; its automaticity; and its role as a credible commitment mechanism. The essays in this collection are organized around several themes: Gold and the international monetary system; the commodity theory of money; the Gold Standard as a rule; variants of the Gold Standard including the interwar Gold Standard and the Bretton Woods International Monetary System.
-
Was Adherence to the Gold Standard a
1999Co-Authors: Michael D. Bordo, Michael Edelstein, Hugh RockoffAbstract:World War I dramatically altered the world's financial landscape. Most countries left the Gold Standard, and New York replaced London as the major lender in world capital markets. This paper discusses how the Gold exchange Standard was reconstructed in the 1920s. We show that the U.S. capital market viewed returning to the Gold Standard as a signal of financial rectitude, what we have referred to in other work as a 'Good Housekeeping Seal of Approval.' When countries returned to Gold, especially when they did so at the prewar parity, they were rewarded with the ability to borrow at substantially lower interest rates. Other signals of financial rectitude, such as small fiscal deficits, apparently carried little weight with lenders.
-
the Gold Standard as a good housekeeping seal of approval
The Journal of Economic History, 1996Co-Authors: Michael D. Bordo, Hugh RockoffAbstract:In this paper we argue that adherence to the Gold Standard rule of convertibility of national currencies into a fixed weight of Gold served as a `good housekeeping seal of approval' which facilitated access by peripheral countries to foreign capital from the core countries of western Europe. We survey the historical background of Gold Standard adherence in the period 1870-1914 by nine important peripheral countries. The sample includes the full range of commitment to the Gold Standard from continuous adherence, through intermittent adherence, to non-adherence. Evidence on the pattern of long-term government bond yields suggests that long-term commitment to the Gold Standard mattered even when bonds were denominated in Gold: countries that remained on Gold throughout the classical era were charged lower rates than countries that had a mixed record of adherence. Estimation of a model analogous to the CAPM, using the differential between peripheral country rates and UK rates augmented by a list of `fundamentals' and a dummy variable to capture Gold Standard adherence, reveals that capital markets attached significant weight to Gold Standard adherence. Countries with poor adherence records were charged considerably more than those with good records, enough to explain the determined effort to stay on Gold made by a number of capital importing countries.
-
The Gold Standard as a `Good Housekeeping Seal of Approval'
National Bureau of Economic Research, 1995Co-Authors: Michael D. BordoAbstract:In this paper we argue that adherence to the Gold Standard rule of convertibility of national currencies into a fixed weight of Gold served as a `good housekeeping seal of approval' which facilitated access by peripheral countries to foreign capital from the core countries of western Europe. We survey the historical background of Gold Standard adherence in the period 1870-1914 by nine important peripheral countries. The sample includes the full range of commitment to the Gold Standard from continuous adherence, through intermittent adherence, to non-adherence. Evidence on the pattern of long-term government bond yields suggests that long-term commitment to the Gold Standard mattered even when bonds were denominated in Gold: countries that remained on Gold throughout the classical era were charged lower rates than countries that had a mixed record of adherence. Estimation of a model analogous to the CAPM, using the differential between peripheral country rates and UK rates augmented by a list of `fundamentals' and a dummy variable to capture Gold Standard adherence, reveals that capital markets attached significant weight to Gold Standard adherence. Countries with poor adherence records were charged considerably more than those with good records, enough to explain the determined effort to stay on Gold made by a number of capital importing countries.
-
The Gold Standard and Other Monetary Regimes
1992Co-Authors: Michael D. BordoAbstract:In recent years, my research has focused on three topics that I discuss here: the performance of the Gold Standard and its Bretton Woods variant; the Gold Standard as a rule - that is, as a credible commitment mechanism; and the performance of alternative monetary rules. The Performance of the Gold Standard and Bretton Woods Monetary Regimes Under the classical Gold Standard, adherents' monetary authorities were required to fix the prices of their currencies in terms of a fixed weight of Gold and to buy and sell Gold freely in unlimited amounts. The pledge to fix the price of Gold provided a nominal anchor for the international monetary system. Under the Bretton Woods system, in contrast, only the United States fixed the price of the dollar in terms of Gold. All other convertible currencies were pegged to the dollar. Also under Bretton Woods, free convertibility of Gold into dollars was limited. Thus, Bretton Woods was a weak variant of the Gold Standard. Comparing the performance of a number of important nominal and real macro variables across four regimes (the classical Gold Standard, the interwar period, Bretton Woods, and floating exchange rates) for the G-7 countries, using annual data, reveals that the Bretton Woods system was the most stable for virtually every variable. The Gold Standard was second. Further, the Bretton Woods convertible period (1959-71) had the lowest Standard deviation of both the inflation rate and the growth of real output.(1) Under the classical Gold Standard, the Standard deviation of both variables was higher than under Bretton Woods and the recent float.(2) Although the classical Gold Standard was not characterized by short-run price stability, it did exhibit long-run price stability from 1821-1914.(3) For a number of key countries from the eighteenth century to the present, the Gold Standard episodes are virtually without inflation persistence compared to the post-World War II era when inflation is significant and positive.(4) Inflation persistence was lower in the fully convertible Bretton Woods period (1959-71) than in the preconvertible period and the subsequent floating exchange rate period.(5) This illustrates the importance of the stable nominal anchor provided by the Gold Standard and its Bretton Woods variant.(6) As is argued in the next section, the Gold Standard also may have provided a credible commitment mechanism. Finally, although the Bretton Woods system in its convertible phase was the most stable monetary regime of the past century, it was also short-lived. Whether it was stable because of the regime, or because of the absence of large shocks compared to other regimes, is an empirical question. Some recent evidence suggests it reflected both influences.(7) The Bretton Woods system collapsed both because of fatal flaws in its design (the adjustable peg in the face of improved capital mobility, and the confidence problem associated with the Gold dollar Standard) and conflicting policy objectives between the key deficit and surplus countries.(8) The Gold Standard as a Commitment Mechanism The evidence that inflation under the Gold Standard and Bretton Woods was markedly less persistent than under regimes without a nominal anchor suggests that the Gold Standard rule of convertibility was a credible commitment mechanism. In the recent literature on the time inconsistency of optimal government policy, the absence of such a mechanism leads governments that pursue stabilization policies to experience inflation.(9) Once the monetary authority has announced a given rate of monetary growth, believing that the public expects it to follow through, the authority has an incentive to create a monetary surprise either to reduce unemployment or to capture seigniorage revenue. With rational expectations, the public will come to anticipate the authorities' perfidy, leading to an inflationary equilibrium. …
Jordi Alberola - One of the best experts on this subject based on the ideXlab platform.
-
leishmania infection laboratory diagnosing in the absence of a Gold Standard
American Journal of Tropical Medicine and Hygiene, 2010Co-Authors: Alheli Rodriguezcortes, Ana Ojeda, Olga Francino, Laura Lopezfuertes, Marcos Timon, Jordi AlberolaAbstract:There is no Gold Standard for diagnosing leishmaniases. Our aim was to assess the operative validity of tests used in detecting Leishmania infection using samples from experimental infections, a reliable equivalent to the classic definition of Gold Standard. Without statistical differences, the highest sensitivity was achieved by protein A (ProtA), immunoglobulin (Ig)G2, indirect fluorescenece antibody test (IFAT), lymphocyte proliferation assay, quantitative real-time polymerase chain reaction of bone marrow (qPCR-BM), qPCR-Blood, and IgG; and the highest specificity by IgG1, IgM, IgA, qPCR-Blood, IgG, IgG2, and qPCR-BM. Maximum positive predictive value was obtained simultaneously by IgG2, qPCR-Blood, and IgG; and maximum negative predictive value by qPCR-BM. Best positive and negative likelihood ratios were obtained by IgG2. The test having the greatest, statistically significant, area under the receiver operating characteristics curve was IgG2 enzyme-linked immunosorbent assay (ELISA). Thus, according to the Gold Standard used, IFAT and qPCR are far from fulfilling the requirements to be considered Gold Standards, and the test showing the highest potential to detect Leishmania infection is Leishmania-specific ELISA IgG2.
-
Leishmania Infection: Laboratory Diagnosing in the Absence of a “Gold Standard”
American Journal of Tropical Medicine and Hygiene, 2010Co-Authors: Alhelí Rodríguez-cortés, Ana Ojeda, Olga Francino, Marcos Timon, Laura López-fuertes, Jordi AlberolaAbstract:There is no Gold Standard for diagnosing leishmaniases. Our aim was to assess the operative validity of tests used in detecting Leishmania infection using samples from experimental infections, a reliable equivalent to the classic definition of Gold Standard. Without statistical differences, the highest sensitivity was achieved by protein A (ProtA), immunoglobulin (Ig)G2, indirect fluorescenece antibody test (IFAT), lymphocyte proliferation assay, quantitative real-time polymerase chain reaction of bone marrow (qPCR-BM), qPCR-Blood, and IgG; and the highest specificity by IgG1, IgM, IgA, qPCR-Blood, IgG, IgG2, and qPCR-BM. Maximum positive predictive value was obtained simultaneously by IgG2, qPCR-Blood, and IgG; and maximum negative predictive value by qPCR-BM. Best positive and negative likelihood ratios were obtained by IgG2. The test having the greatest, statistically significant, area under the receiver operating characteristics curve was IgG2 enzyme-linked immunosorbent assay (ELISA). Thus, according to the Gold Standard used, IFAT and qPCR are far from fulfilling the requirements to be considered Gold Standards, and the test showing the highest potential to detect Leishmania infection is Leishmania-specific ELISA IgG2.
Nancy Cartwright - One of the best experts on this subject based on the ideXlab platform.
-
are rcts the Gold Standard
Biosocieties, 2007Co-Authors: Nancy CartwrightAbstract:The claims of randomized controlled trials (RCTs) to be the Gold Standard rest on the fact that the ideal RCT is a deductive method: if the assumptions of the test are met, a positive result implies the appropriate causal conclusion. This is a feature that RCTs share with a variety of other methods, which thus have equal claim to being a Gold Standard. This article describes some of these other deductive methods and also some useful non-deductive methods, including the hypothetico-deductive method. It argues that with all deductive methods, the benefit that the conclusions follow deductively in the ideal case comes with a great cost: narrowness of scope. This is an instance of the familiar trade-off between internal and external validity. RCTs have high internal validity but the formal methodology puts severe constraints on the assumptions a target population must meet to justify exporting a conclusion from the test population to the target. The article reviews one such set of assumptions to show the kind of knowledge required. The overall conclusion is that to draw causal inferences about a target population, which method is best depends case-by-case on what background knowledge we have or can come to obtain. There is no Gold Standard.
-
Are RCTs the Gold Standard?
BioSocieties, 2007Co-Authors: Nancy CartwrightAbstract:The claims of RCTs to be the Gold Standard rest on the fact that the ideal RCT is a deductive method: if the assumptions of the test are met, a positive result implies the appropriate causal conclusion. This is a feature that RCTs share with a variety of other methods, which thus have equal claim to being a Gold Standard. This paper describes some of these other deductive methods and also some useful non-deductive methods, including the hypothetico-deductive method. It argues that with all deductive methods, the benefit that the conclusions follow deductively in the ideal case comes with a great cost: narrowness of scope. This is an instance of the familiar trade-off between internal and external validity. RCTs have high internal validity but the formal methodology puts severe constraints on the assumptions a target population must meet to justify exporting a conclusion from the test population to the target. The paper reviews one such set of assumptions to show the kind of knowledge required. The overall conclusion is that to draw causal inferences about a target population, which method is best depends case-by-case on what background knowledge we have or can come to obtain. There is no Gold Standard.
Alheli Rodriguezcortes - One of the best experts on this subject based on the ideXlab platform.
-
leishmania infection laboratory diagnosing in the absence of a Gold Standard
American Journal of Tropical Medicine and Hygiene, 2010Co-Authors: Alheli Rodriguezcortes, Ana Ojeda, Olga Francino, Laura Lopezfuertes, Marcos Timon, Jordi AlberolaAbstract:There is no Gold Standard for diagnosing leishmaniases. Our aim was to assess the operative validity of tests used in detecting Leishmania infection using samples from experimental infections, a reliable equivalent to the classic definition of Gold Standard. Without statistical differences, the highest sensitivity was achieved by protein A (ProtA), immunoglobulin (Ig)G2, indirect fluorescenece antibody test (IFAT), lymphocyte proliferation assay, quantitative real-time polymerase chain reaction of bone marrow (qPCR-BM), qPCR-Blood, and IgG; and the highest specificity by IgG1, IgM, IgA, qPCR-Blood, IgG, IgG2, and qPCR-BM. Maximum positive predictive value was obtained simultaneously by IgG2, qPCR-Blood, and IgG; and maximum negative predictive value by qPCR-BM. Best positive and negative likelihood ratios were obtained by IgG2. The test having the greatest, statistically significant, area under the receiver operating characteristics curve was IgG2 enzyme-linked immunosorbent assay (ELISA). Thus, according to the Gold Standard used, IFAT and qPCR are far from fulfilling the requirements to be considered Gold Standards, and the test showing the highest potential to detect Leishmania infection is Leishmania-specific ELISA IgG2.
