3,073 research outputs found
Short-term headline-core inflation dynamics
This article investigates empirically short-term dynamics between headline and core measures of consumer price index and personal consumption expenditure inflation over three sample periods: 1959:1-1979:1, 1979:2-2001:2, and 1985:1-2007:2. Headline and core inflation measures are co-integrated, suggesting long-run co-movement. However, the ways these two variables adjust to each other in the short run and generate co-movement have changed across these sample periods. In the pre-1979 sample period, when a positive gap opens up with headline inflation rising above core inflation, the gap is eliminated mainly as a result of headline inflation not reverting and core inflation moving toward headline inflation. These dynamics suggest headline inflation would be better than core inflation in assessing the permanent component of inflation. In post-1979 sample periods, however, the positive gap is eliminated as a result of headline inflation reverting more strongly toward core inflation than core inflation moving toward headline inflation, suggesting core inflation would be better than headline inflation in assessing the permanent component of inflation. This change in headline-core inflation dynamics may be due to the Federal Reserve having convinced the public it would no longer accommodate shocks to food and energy prices.Inflation (Finance) ; Monetary policy
The case for management in the Turkish-Kurdish conflict.
The Turkish-Kurdish conflict has ravaged Turkey for nearly 34 years. It is one of the world’s longest enduring rivalries, garnering significant international attention. Since 1984, experts estimate that at least 30,000 people have died in this conflict. In just the past two years, the fighting has killed 3,362 peopleand displaced another half million people. Although the parties have attempted to resolve this dispute multiple times, a comprehensive peace deal has remained elusive. So what should be done about this conflict? Is there a way to compel these parties to forge a lasting peace deal? Or, should the international community focus on ameliorating the most pernicious effects of the conflict until peace seems more attainable?
This paper will begin by recounting a short history of the Kurds in Turkey, the beginnings of the insurgency, and the former attempts at peace negotiations. Then, it will analyze the most recent negotiation between Turkey and the PKK, followed by a discussion of the reasons that those negotiations collapsed and recent developments in Turkey. This paper will then elucidate four primary strategies that the literature has suggested to resolve ethnic conflicts and discuss why each of those models seems unlikely to resolve the Turkish-PKK dispute. This paper will conclude by anticipating the possibility for another round of peace negotiations and will introduce a new, conflict-management model to promote cooperation between the parties until they can reach a comprehensive peace deal
Forecasting volatility in commodity markets
Commodity prices have historically been among the most volatile of international prices. Measured volatility (the standard deviation of price changes) has not been below 15 percent and at times has been more than 50 percent. Often the volatility of commodity prices has exceeded that of exchange rates and interest rates. The large price variations are caused by disturbances in demand and supply. Stockholding leads to some price smoothing, but when stocks are low, prices can jump sharply. As a result, commodity price series are not stationary and in some periods they jump abruptly to high levels or fall precipitously to low levels relative to their long-run average. Thus it is difficult to determine long-term price trends and the underlying distribution of prices. The volatility of commodity prices makes price forecasting difficult. Indeed, realized prices often deviate greatly from forecasted prices, which has led to the practice of giving forecasts probability ranges. But assigning probability ranges requires forecasting future price volatility, which, given uncertainties about true price distribution, is difficult. One potentially useful source of information for forecasting volatility is the volatility forecasts imbedded in the prices of options written on commodities traded in exchanges. Options give the holder the right to buy (call) or sell (put) a certain commodity at a certain date at a fixed (exercise) price. Options prices depend on several variables, one of which is the expected volatility up to the maturity date. Given a specific theoretical model, the market prices of options can be used to derive the market's expectations about price volatility and the price distribution. The authors systematically analyze different methods'abilities to forecast commodity price volatility (for several commodities). They collected the daily prices of commodity options and other variables for seven commodities (cocoa, corn, cotton, gold, silver, sugar, and wheat). They extracted the volatility forecasts implicit in options prices using several techniques. They compared several volatility forecasting methods, divided into three categories: (1) forecasts using only expectations derived form options prices; (2) forecasts using only time-series modeling; (3) forecasts that combine market expectations and time-series modeling (a new method devised for this purpose). They find that the volatility forecasts produced by method 3 outperform the first two as well as the naive forecast based on historical volatility. This result holds both in and out of sample for almost all commodities considered.Markets and Market Access,Access to Markets,Economic Theory&Research,Economic Forecasting,Science Education
The induction of synaesthesia with chemical agents: A systematic review
Despite the general consensus that synaesthesia emerges at an early developmental stage and is only rarely acquired during adulthood, the transient induction of synaesthesia with chemical agents has been frequently reported in research on different psychoactive substances. Nevertheless, these effects remain poorly understood and have not been systematically incorporated. Here we review the known published studies in which chemical agents were observed to elicit synaesthesia. Across studies there is consistent evidence that serotonin agonists elicit transient experiences of synaesthesia. Despite convergent results across studies, studies investigating the induction of synaesthesia with chemical agents have numerous methodological limitations and little experimental research has been conducted. Cumulatively, these studies implicate the serotonergic system in synaesthesia and have implications for the neurochemical mechanisms underlying this phenomenon but methodological limitations in this research area preclude making firm conclusions regarding whether chemical agents can induce genuine synaesthesia
Intramolecular Phenotypic Capacitance in a Modular RNA Molecule
Phenotypic capacitance refers to the ability of a genome to accumulate mutations that are conditionally hidden and only reveal phenotype-altering effects after certain environmental or genetic changes. Capacitance has important implications for the evolution of novel forms and functions, but experimentally studied mechanisms behind capacitance are mostly limited to complex, multicomponent systems often involving several interacting protein molecules. Here we demonstrate phenotypic capacitance within a much simpler system, an individual RNA molecule with catalytic activity (ribozyme). This naturally occurring RNA molecule has a modular structure, where a scaffold module acts as an intramolecular chaperone that facilitates folding of a second catalytic module. Previous studies have shown that the scaffold module is not absolutely required for activity, but dramatically decreases the concentration of magnesium ions required for the formation of an active site. Here, we use an experimental perturbation of magnesium ion concentration that disrupts the folding of certain genetic variants of this ribozyme and use in vitro selection followed by deep sequencing to identify genotypes with altered phenotypes (catalytic activity). We identify multiple conditional mutations that alter the wild-type ribozyme phenotype under a stressful environmental condition of low magnesium ion concentration, but preserve the phenotype under more relaxed conditions. This conditional buffering is confined to the scaffold module, but controls the catalytic phenotype, demonstrating how modularity can enable phenotypic capacitance within a single macromolecule. RNA’s ancient role in life suggests that phenotypic capacitance may have influenced evolution since life’s origins
Saccharomyces yeast hybrids on the rise
Saccharomyces hybrid yeasts are receiving increasing attention as a powerful model system to understand adaptation to environmental stress and speciation mechanisms, using experimental evolution and omics techniques. We compiled all genomic resources available from public repositories of the eight recognized Saccharomyces species and their interspecific hybrids. We present the newest numbers on genomes sequenced, assemblies, annotations, and sequencing runs, and an updated species phylogeny using orthogroup inference. While genomic resources are highly skewed towards Saccharomyces cerevisiae, there is a noticeable movement to use wild, recently discovered yeast species in recent years. To illustrate the degree and potential causes of reproductive isolation, we reanalyzed published data on hybrid spore viabilities across the entire genus and tested for the role of genetic, geographic, and ecological divergence within and between species (28 cross types and 371 independent crosses). Hybrid viability generally decreased with parental genetic distance likely due to antirecombination and negative epistasis, but notable exceptions emphasize the importance of strain-specific structural variation and ploidy differences. Surprisingly, the viability of crosses within species varied widely, from near reproductive isolation to near-perfect viability. Geographic and ecological origins of the parents predicted cross viability to an extent, but with certain caveats. Finally, we highlight publication trends in the field and point out areas of special interest, where hybrid yeasts are particularly promising for innovation through research and development, and experimental evolution and fermentation
R You Still Using Excel? The Advantages of Modern Software Tools for Health Technology Assessment
The Professional Society for Health Economics and Outcomes Research Economic models are used in health technology assessments (HTAs) to evaluate the cost-effectiveness of competing medical technologies and inform the efficient use of health care resources. Historically, these models have been developed with specialized commercial software (such as TreeAge) or more commonly with spreadsheet software (almost always Microsoft Excel). Although these tools may be sufficient for relatively simple analyses, they put unnecessary constraints on the analysis that may ultimately limit its credibility and relevance. In contrast, modern programming languages such as R, Python, Matlab, and Julia facilitate the development of models that are (i) clinically realistic, (ii) capable of quantifying decision uncertainty, (iii) transparent and reproducible, and (iv) reusable and adaptable. An HTA environment that encourages use of modern software can therefore help ensure that coverage and pricing decisions confer greatest possible benefit and capture all scientific uncertainty, thus enabling correct prioritization of future research
Designing antibiotic cycling strategies by determining and understanding local adaptive landscapes
The evolution of antibiotic resistance among bacteria threatens our continued
ability to treat infectious diseases. The need for sustainable strategies to
cure bacterial infections has never been greater. So far, all attempts to
restore susceptibility after resistance has arisen have been unsuccessful,
including restrictions on prescribing [1] and antibiotic cycling [2,3]. Part of
the problem may be that those efforts have implemented different classes of
unrelated antibiotics, and relied on removal of resistance by random loss of
resistance genes from bacterial populations (drift). Here, we show that
alternating structurally similar antibiotics can restore susceptibility to
antibiotics after resistance has evolved. We found that the resistance
phenotypes conferred by variant alleles of the resistance gene encoding the TEM
{\beta}-lactamase (blaTEM) varied greatly among 15 different {\beta}-lactam
antibiotics. We captured those differences by characterizing complete adaptive
landscapes for the resistance alleles blaTEM-50 and blaTEM-85, each of which
differs from its ancestor blaTEM-1 by four mutations. We identified pathways
through those landscapes where selection for increased resistance moved in a
repeating cycle among a limited set of alleles as antibiotics were alternated.
Our results showed that susceptibility to antibiotics can be sustainably
renewed by cycling structurally similar antibiotics. We anticipate that these
results may provide a conceptual framework for managing antibiotic resistance.
This approach may also guide sustainable cycling of the drugs used to treat
malaria and HIV
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