1,744 research outputs found
Monetary Policy and Credit in China: a Theoretical Analysis
A three-sector macro model of the Chinese economy is developed in which the activity of state-owned enterprises (SOEs) is constrained by the state-imposed credit plan for working capital. Our analysis indicates the weaknesses of credit control and nominal interest rate increases as tools for holding down the price level; but the hardening of SOEs’ budget constraints is found to be an effective device. The existence of credit and currency controls tends to make devaluation contractionary. Because of general equilibrium repercussions, policies that boost industrial exports tend to reduce welfare in the agricultural sector, where poverty is concentrated.
Testing Gravity in the Outer Solar System: Results from Trans-Neptunian Objects
The inverse square law of gravity is poorly probed by experimental tests at
distances of ~ 10 AUs. Recent analysis of the trajectory of the Pioneer 10 and
11 spacecraft have shown an unmodeled acceleration directed toward the Sun
which was not explained by any obvious spacecraft systematics, and occurred
when at distances greater than 20 AUs from the Sun. If this acceleration
represents a departure from Newtonian gravity or is indicative of an additional
mass distribution in the outer solar system, it should be detectable in the
orbits of Trans-Neptunian Objects (TNOs). To place limits on deviations from
Newtonian gravity, we have selected a well observed sample of TNOs found
orbiting between 20 and 100 AU from the Sun. By examining their orbits with
modified orbital fitting software, we place tight limits on the perturbations
of gravity that could exist in this region of the solar system.Comment: 20 pages, 4 figures, 2 tables, uses AASTex v5.x macro
A phase 1 trial of nebulised heparin in acute lung injury
INTRODUCTION: Animal studies of acute lung injury (ALI) suggest nebulised heparin may limit damage from fibrin deposition in the alveolar space and microcirculation. No human studies have been undertaken to date. We assessed the feasibility, safety and potential anticoagulant effects of administration of nebulised heparin to patients with ALI. METHODS: An open label phase 1 trial of four escalating doses of nebulised heparin was performed. A total of 16 ventilated patients with ALI were studied. The first group was administered a total of 50,000 U/day, the second group 100,000 U/day, the third group 200,000 U/day and the fourth group 400,000 U/day. Assessments of lung function included the PaO2/FiO2 ratio, lung compliance and the alveolar dead space fraction. Monitoring of anticoagulation included the activated partial thromboplastin time (APTT) and the thrombin clotting time. Bronchoalveolar lavage fluid was collected and the prothrombin fragment and tissue plasminogen activator levels were assessed. Analysis of variance was used to compare the effects of dose. RESULTS: No serious adverse events occurred for any dose. The changes over time for the PaO2/FiO2 ratio, lung compliance and the alveolar dead space fraction levels were similar for all doses. A trend to increased APTT and thrombin clotting time levels was present with higher doses (P = 0.09 and P = 0.1, respectively). For the highest dose, the APTT reached 64 seconds; following cessation of nebulised heparin, the APTT fell to 39 seconds (P = 0.06). In bronchoalveolar lavage samples a trend to reduced prothrombin fragment levels was present with higher doses (P = 0.1), while tissue plasminogen activator levels were similar for all doses. CONCLUSION: Administration of nebulised heparin to mechanically ventilated patients with ALI is feasible. Nebulised heparin was not associated with any serious adverse events, and at higher doses it increased APTT levels. Larger trials are required to further investigate the safety and efficacy of nebulised heparin. In these trials due consideration must be given to systemic anticoagulant effects. TRIAL REGISTRATION: Australian Clinical trials registry ACTRN12606000388516
Editorial: Bound to Necessity?
What is the purpose of research into the teaching of English? Knowledge and understanding are required to work effectively with learners of any age, but these principles include both what is traditionally known as techne – the skill or craft required to achieve a desired outcome – and the wider understanding denoted by episteme. Given the economic and political circumstances within which educators worldwide currently work, it may not be surprising that much of the research presented in this issue of English in Education concerns episteme rather than techne
Can Minor Planets be Used to Assess Gravity in the Outer Solar System?
The twin Pioneer spacecraft have been tracked for over thirty years as they
headed out of the solar system. After passing 20 AU from the Sun, both
exhibited a systematic error in their trajectories that can be interpreted as a
constant acceleration towards the Sun. This Pioneer Effect is most likely
explained by spacecraft systematics, but there have been no convincing
arguments that that is the case. The alternative is that the Pioneer Effect
represents a real phenomenon and perhaps new physics. What is lacking is a
means of measuring the effect, its variation, its potential anisotropies, and
its region of influence. We show that minor planets provide an observational
vehicle for investigating the gravitational field in the outer solar system,
and that a sustained observation campaign against properly chosen minor planets
could confirm or refute the existence of the Pioneer Effect. Additionally, even
if the Pioneer Effect does not represent a new physical phenomenon, minor
planets can be used to probe the gravitational field in the outer Solar System
and since there are very few intermediate range tests of gravity at the
multiple AU distance scale, this is a worthwhile endeavor in its own right.Comment: Accepted for publication in The Astrophysical Journa
Tracking Cyber Adversaries with Adaptive Indicators of Compromise
A forensics investigation after a breach often uncovers network and host
indicators of compromise (IOCs) that can be deployed to sensors to allow early
detection of the adversary in the future. Over time, the adversary will change
tactics, techniques, and procedures (TTPs), which will also change the data
generated. If the IOCs are not kept up-to-date with the adversary's new TTPs,
the adversary will no longer be detected once all of the IOCs become invalid.
Tracking the Known (TTK) is the problem of keeping IOCs, in this case regular
expressions (regexes), up-to-date with a dynamic adversary. Our framework
solves the TTK problem in an automated, cyclic fashion to bracket a previously
discovered adversary. This tracking is accomplished through a data-driven
approach of self-adapting a given model based on its own detection
capabilities.
In our initial experiments, we found that the true positive rate (TPR) of the
adaptive solution degrades much less significantly over time than the naive
solution, suggesting that self-updating the model allows the continued
detection of positives (i.e., adversaries). The cost for this performance is in
the false positive rate (FPR), which increases over time for the adaptive
solution, but remains constant for the naive solution. However, the difference
in overall detection performance, as measured by the area under the curve
(AUC), between the two methods is negligible. This result suggests that
self-updating the model over time should be done in practice to continue to
detect known, evolving adversaries.Comment: This was presented at the 4th Annual Conf. on Computational Science &
Computational Intelligence (CSCI'17) held Dec 14-16, 2017 in Las Vegas,
Nevada, US
The TIGRE gamma-ray telescope
TIGRE is an advanced telescope for gamma-ray astronomy with a few arcmin resolution. From 0.3 to 10 MeV it is a Compton telescope. Above 1 MeV, its multi-layers of double sided silicon strip detectors allow for Compton recoil electron tracking and the unique determination for incident photon direction. From 10 to 100 MeV the tracking feature is utilized for gamma-ray pair event reconstruction. Here we present TIGRE energy resolutions, background simulations and the development of the electronics readout system
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