213 research outputs found
Early Results from NOAA-20 (JPSS-1) Viirs On-Orbit Calibration and Characterization
Since launch in November 2018, the VIIRS on-board the NOAA-20 (or JPSS-1) satellite has completed its initial intensive on-orbit check-outs and several key calibration and validation activities scheduled to help evaluate sensor at launch performance. This paper provides a brief overview of NOAA-20 VIIRS on-orbit operation and calibration activities, presents early results derived from its on-board calibrators and lunar observations, and discusses potential improvements and future effort to assure sensor data product quality
Strategy revision opportunities and collusion
This paper studies whether and how strategy revision opportunities affect levels of collusion in indefinitely repeated two-player games. Consistent with standard theory, we find that such opportunities do not affect strategy choices, or collusion levels, if the game is of strategic substitutes. In games of strategic complements, by contrast, revision opportunities lead to more collusion. We discuss alternative explanations for this result
PPI-Delayed Diagnosis of Gastrinoma: Oncologic Victim of Pharmacologic Success
Functional neuroendocrine tumors are often low-grade malignant neoplasms that can be cured by surgery if detected early, and such detection may in turn be accelerated by the recognition of neuropeptide hypersecretion syndromes. Uniquely, however, relief of peptic symptoms induced by hypergastrinemia is now available from acid-suppressive drugs such as proton-pump inhibitors (PPIs). Here we describe a clinical case in which time to diagnosis from the onset of peptic symptoms was delayed more than 10 years, in part reflecting symptom masking by continuous prescription of the PPI omeprazole. We propose diagnostic criteria for this under-recognized new clinical syndrome, and recommend that physicians routinely measure serum gastrin levels in persistent cases of PPI-dependent dyspepsia unassociated with H. pylori
Ultrasonographically detected gallbladder polyps: A reason for concern? A seven-year follow-up study
Trust, Salience and Deterrence: Evidence from an Antitrust Experiment
We present results from a laboratory experiment identifying the main channels through which different law enforcement strategies deter organized economic crime. The absolute level of a fine has a strong deterrence effect, even when the exogenous probability of apprehension is zero. This effect appears to be driven by distrust or fear of betrayal, as it increases significantly when the incentives to betray partners are strengthened by policies offering amnesty to “turncoat whistleblowers”. We also document a strong deterrence effect of the sum of fines paid in the past, which suggests a significant role for salience or availability heuristic in law enforcement
IL28B genetic variations are associated with high sustained virological response (SVR) of interferon-α plus ribavirin therapy in Taiwanese chronic HCV infection
Chronic hepatitis C virus (HCV) infection patients exhibit different sustained virological responses (SVRs) following the treatment with pegylated interferon-α (IFN-α) and ribavirin. Genome-wide association studies consistently linked SVR of IFN-α-based therapy to the IL28B single-nucleotide polymorphisms (SNPs) on chromosome 19q.13 in various populations. This study was undertaken to investigate the association of IL28B SNPs with SVR in a cohort of Taiwanese chronic HCV patients. Ten SNPs of IL28B were genotyped in 728 chronic HCV patients and 960 healthy controls. Genotype distributions, allele frequencies and haplotypes were tested for SVR and susceptibility in Taiwanese chronic HCV patients. Non-genotype 1 infection (adjusted P=3.3 × 10−12, odds ratio (OR) 0.179; 95% confidence interval (CI): 0.110–0.290) and low HCV viral load (<400 000 IU ml–1) (adjusted P=3.5 × 10−9, OR 0.299; 95% CI: 0.200–0.446) were two major factors identified for high SVR. Notably, eight IL28B SNPs including previously described disease-associated SNPs (Trend test P=0.005) were significantly associated with SVR. Our data indicate that IL28B polymorphisms are the essential contributing factors for high SVR in Taiwanese chronic HCV patients. Combination of virus genotyping and host genetic data may be used to select the optimal treatment regimes in IFN-based therapy
Relational Contracting, Repeated Negotiations, and Hold-Up
We propose a unified framework to study relational contracting and hold-up problems in infinite horizon stochastic games. We first illustrate that with respect to long run decisions, the common formulation of relational contracts as Pareto-optimal public perfect equilibria is in stark contrast to fundamental assumptions of hold-up models. We develop a model in which relational contracts are repeatedly newly negotiated during relationships. Negotiations take place with positive probability and cause bygones to be bygones. Traditional relational contracting and hold-up formulations are nested as opposite corner cases. Allowing for intermediate cases yields very intuitive results and sheds light on many plausible trade-offs that do not arise in these corner cases. We establish a general existence result and a tractable characterization for stochastic games in which money can be transferred. This paper formulates a theory of relational contracting in dynamic games. A crucial feature is that existing relational contracts can depreciate and ensuing negotiations then treat previous informal agreements as bygones. The model nests the traditional formulation of relational contracts as Pareto-optimal equilibria as a special case. In repeated games both formulations are always mathematically equivalent. We provide ample illustrations that in dynamic games the traditional formulation is restrictive in so far that it rules out by assumption many plausible hold-up problems - even for small discount factors. Our model provides a framework that naturally unifies the analysis of relational contracting and hold-up problems
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