1,205 research outputs found
Monetary Policy Challenges for Emerging Market Economies
This paper introduces a significant new collection of papers on monetary policy in emerging market economies, written by leading analysts and policy makers. Does existing economic theory provide lessons that are pertinent for designing effective monetary policy frameworks in emerging markets? What can be learned from cross-country studies and from experiences of individual countries that have adopted different approaches? While country-specific circumstances and initial conditions matter a great deal in formulating suitable frameworks, are there clear general principles that can serve as a guide in this process? These are among the issues addressed in the dialogue between academics and policy makers represented in this volume. In this paper, we provide an overview of the main issues, linking them to broader debates in the academic literature as well as an assessment of how individual countries have chosen to respond to specific policy challenges and what the consequences have been. We discuss many controversies where there are still sharp differences in views between and amongst theorists and practitioners. We also delineate a few key analytical issues where there is still a yawning gap between theory and practice. In the process, we set out a broad agenda for further research in this area.Emerging Markets, Monetary Policy, Economies, International Development, International Relations/Trade, Political Economy, Public Economics,
Retrospective review of a Prothrombin Complex Concentrate (Beriplex P/N) for the management of perioperative bleeding unrelated to oral anticoagulation
A multicenter, retrospective, observational study of 4-factor prothrombin complex concentrate (PCC) and/or fresh frozen
plasma (FFP) use within routine clinical care unrelated to vitamin K antagonists was conducted. The PCC was administered
preprocedure for correction of coagulopathy (prophylactic cohort) and treatment of bleeding postsurgery (treatment cohort). Of
the 445 patients included, 40 were in the prophylactic cohort (PCC alone [n ¼ 16], PCC and FFP [n ¼ 5], FFP alone [n ¼ 19]) and
405 were in the treatment cohort (PCC alone [n ¼ 228], PCC and FFP [n ¼ 123], FFP alone [n ¼ 54]). Cardiovascular surgery was
the most common setting. PCC doses ranged between 500 and 5000 IU. Effectiveness (assessed retrospectively) was reported as
effective in 93.0% in the PCC-only group (95% confidence interval, 89.1% to 95.9%), 78.9% (70.8% to 85.6%) with PCC and FFP,
and 86.3% (76.2% to 93.2%) with FFP alone. In the treatment cohort, international normalized ratio was significantly reduced in all
3 groups. In patients who received PCC, the rate of thromboembolic events (1.9%) was below rates in the literature for similar
procedures. PCCs offer a potential alternative to FFP in the management of perioperative bleeding unrelated to oral anticoagulant
therapy
Deep Learning Based Forecasting of Indian Summer Monsoon Rainfall
Accurate short range weather forecasting has significant implications for
various sectors. Machine learning based approaches, e.g., deep learning, have
gained popularity in this domain where the existing numerical weather
prediction (NWP) models still have modest skill after a few days. Here we use a
ConvLSTM network to develop a deep learning model for precipitation
forecasting. The crux of the idea is to develop a forecasting model which
involves convolution based feature selection and uses long term memory in the
meteorological fields in conjunction with gradient based learning algorithm.
Prior to using the input data, we explore various techniques to overcome
dataset difficulties. We follow a strategic approach to deal with missing
values and discuss the models fidelity to capture realistic precipitation. The
model resolution used is (25 km). A comparison between 5 years of predicted
data and corresponding observational records for 2 days lead time forecast show
correlation coefficients of 0.67 and 0.42 for lead day 1 and 2 respectively.
The patterns indicate higher correlation over the Western Ghats and Monsoon
trough region (0.8 and 0.6 for lead day 1 and 2 respectively). Further, the
model performance is evaluated based on skill scores, Mean Square Error,
correlation coefficient and ROC curves. This study demonstrates that the
adopted deep learning approach based only on a single precipitation variable,
has a reasonable skill in the short range. Incorporating multivariable based
deep learning has the potential to match or even better the short range
precipitation forecasts based on the state of the art NWP models.Comment: 14 pages, 14 figures. The manuscript is under review with journal
'Transactions on Geoscience and Remote Sensing
The Substructure Hierarchy in Dark Matter Haloes
We present a new algorithm for identifying the substructure within simulated
dark matter haloes. The method is an extension of that proposed by Tormen et
al. (2004) and Giocoli et al. (2008a), which identifies a subhalo as a group of
self-bound particles that prior to being accreted by the main progenitor of the
host halo belonged to one and the same progenitor halo (hereafter satellite).
However, this definition does not account for the fact that these satellite
haloes themselves may also have substructure, which thus gives rise to
sub-subhaloes, etc. Our new algorithm identifies substructures at all levels of
this hierarchy, and we use it to determine the mass function of all
substructure (counting sub-haloes, sub-subhaloes, etc.). On average, haloes
which formed more recently tend to have a larger mass fraction in substructure
and to be less concentrated than average haloes of the same mass. We provide
quantitative fits to these correlations. Even though our algorithm is very
different from that of Gao et al. (2004), we too find that the subhalo mass
function per unit mass at redshift z = 0 is universal. This universality
extends to any redshift only if one accounts for the fact that host haloes of a
given mass are less concentrated at higher redshifts, and concentration and
substructure abundance are anti-correlated. This universality allows a simple
parametrization of the subhalo mass function integrated over all host halo
masses, at any given time. We provide analytic fits to this function which
should be useful in halo model analyses which equate galaxies with halo
substructure when interpreting clustering in large sky surveys. Finally, we
discuss systematic differences in the subhalo mass function that arise from
different definitions of (host) halo mass.Comment: 18 pages, 24 figures, accepted for publication on MNRA
Recommended from our members
The EphB4 Receptor Tyrosine Kinase Promotes Lung Cancer Growth: A Potential Novel Therapeutic Target
Despite progress in locoregional and systemic therapies, patient survival from lung cancer remains a challenge. Receptor tyrosine kinases are frequently implicated in lung cancer pathogenesis, and some tyrosine kinase inhibition strategies have been effective clinically. The EphB4 receptor tyrosine kinase has recently emerged as a potential target in several other cancers. We sought to systematically study the role of EphB4 in lung cancer. Here, we demonstrate that EphB4 is overexpressed 3-fold in lung tumors compared to paired normal tissues and frequently exhibits gene copy number increases in lung cancer. We also show that overexpression of EphB4 promotes cellular proliferation, colony formation, and motility, while EphB4 inhibition reduces cellular viability in vitro, halts the growth of established tumors in mouse xenograft models when used as a single-target strategy, and causes near-complete regression of established tumors when used in combination with paclitaxel. Taken together, these data suggest an important role for EphB4 as a potential novel therapeutic target in lung cancer. Clinical trials investigating the efficacy of anti-EphB4 therapies as well as combination therapy involving EphB4 inhibition may be warranted.</p
Randomized evaluation of fibrinogen versus placebo in complex cardiovascular surgery : post hoc analysis and interpretation of phase III results
OBJECTIVES: In a multicentre, randomized-controlled, phase III trial in complex cardiovascular surgery (Randomized Evaluation of Fibrinogen vs Placebo in Complex Cardiovascular Surgery: REPLACE), single-dose human fibrinogen concentrate (FCH) was associated with the transfusion of increased allogeneic blood products (ABPs) versus placebo. Post hoc analyses were performed to identify possible reasons for this result. METHODS: We stratified REPLACE results by adherence to the transfusion algorithm, pretreatment fibrinogen level (2g/l) and whether patients were among the first 3 treated at their centre. RESULTS: Patients whose treatment was adherent with the transfusion algorithm [FCH, n=47 (60.3%); placebo, n=57 (77.0%); P=0.036] received smaller quantities of ABPs than those with non-adherent treatment (P2g/l and fewer patients undergoing thoracoabdominal aortic aneurysm repair. CONCLUSIONS: None of the patient stratifications provided a clear explanation for the lack of efficacy seen for FCH in the REPLACE trial versus the positive phase II outcomes. However, together, the 3 factors demonstrated trends favouring FCH. Less familiarity with the protocol and procedures and unavoidable differences in the study populations may explain the differences seen between the phase II study and REPLACE.Peer reviewe
Demarcating circulation regimes of synchronously rotating terrestrial planets within the habitable zone
We investigate the atmospheric dynamics of terrestrial planets in synchronous rotation within the habitable zone of low-mass stars using the Community Atmosphere Model (CAM). The surface temperature contrast between day and night hemispheres decreases with an increase in incident stellar flux, which is opposite the trend seen on gas giants. We define three dynamical regimes in terms of the equatorial Rossby deformation radius and the Rhines length. The slow rotation regime has a mean zonal circulation that spans from day to night side, with both the Rossby deformation radius and the Rhines length exceeding planetary radius, which occurs for planets around stars with effective temperatures of 3300 K to 4500 K (rotation period > 20 days). Rapid rotators have a mean zonal circulation that partially spans a hemisphere and with banded cloud formation beneath the substellar point, with the Rossby deformation radius is less than planetary radius, which occurs for planets orbiting stars with effective temperatures of less than 3000 K (rotation period < 5 days). In between is the Rhines rotation regime, which retains a thermally-direct circulation from day to night side but also features midlatitude turbulence-driven zonal jets. Rhines rotators occur for planets around stars in the range of 3000 K to 3300 K (rotation period ∼ 5 to 20 days), where the Rhines length is greater than planetary radius but the Rossby deformation radius is less than planetary radius. The dynamical state can be observationally inferred from comparing the morphology of the thermal emission phase curves of synchronously rotating planets
On the Complexity of Scheduling in Wireless Networks
We consider the problem of throughput-optimal scheduling in wireless networks subject to interference constraints. We model the interference using a family of K-hop interference models, under which no two links within a K-hop distance can successfully transmit at the same time. For a given K, we can obtain a throughput-optimal scheduling policy by solving the well-known maximum weighted matching problem. We show that for K > 1, the resulting problems are NP-Hard that cannot be approximated within a factor that grows polynomially with the number of nodes. Interestingly, for geometric unit-disk graphs that can be used to describe a wide range of wireless networks, the problems admit polynomial time approximation schemes within a factor arbitrarily close to 1. In these network settings, we also show that a simple greedy algorithm can provide a 49-approximation, and the maximal matching scheduling policy, which can be easily implemented in a distributed fashion, achieves a guaranteed fraction of the capacity region for "all K." The geometric constraints are crucial to obtain these throughput guarantees. These results are encouraging as they suggest that one can develop low-complexity distributed algorithms to achieve near-optimal throughput for a wide range of wireless networksopen1
Gravitational waves from single neutron stars: an advanced detector era survey
With the doors beginning to swing open on the new gravitational wave
astronomy, this review provides an up-to-date survey of the most important
physical mechanisms that could lead to emission of potentially detectable
gravitational radiation from isolated and accreting neutron stars. In
particular we discuss the gravitational wave-driven instability and
asteroseismology formalism of the f- and r-modes, the different ways that a
neutron star could form and sustain a non-axisymmetric quadrupolar "mountain"
deformation, the excitation of oscillations during magnetar flares and the
possible gravitational wave signature of pulsar glitches. We focus on progress
made in the recent years in each topic, make a fresh assessment of the
gravitational wave detectability of each mechanism and, finally, highlight key
problems and desiderata for future work.Comment: 39 pages, 12 figures, 2 tables. Chapter of the book "Physics and
Astrophysics of Neutron Stars", NewCompStar COST Action 1304. Minor
corrections to match published versio
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