149 research outputs found
Importance of the logistics performance index in international trade
This is an author's accepted manuscript of an article published in:
“Applied Economics"; Volume 46, Issue 24, 2014; copyright Taylor & Francis; available online at: http://dx.doi.org/10.1080/00036846.2014.916394Logistics and transport increasingly play a pivotal role in international trade
relations. The Logistics Performance Index (LPI) analyses differences between
countries in terms of customs procedures, logistics costs and the quality of the
infrastructure for overland and maritime transport. The aim of this article is to
analyse the impact that each of these components has on trade in emerging
economies using a gravity model. Furthermore, the study also attempts to detect
possible advances in logistics in developing countries, which are grouped into
five regions (Africa, South America, Far East, Middle East and Eastern Europe)
by comparing the first LPI data published in 2007 with the most recent data,
released in 2012. The results obtained reveal that improvements in any of the
components of the LPI can lead to significant growth in a country’s trade flows.
Specifically, LPI components are becoming increasingly important for international
trade in many countries in Africa, South America and Eastern Europe.Martí Selva, ML.; Puertas Medina, RM.; García, L. (2014). Importance of the logistics performance index in international trade. Applied Economics. 46(24):2982-2992. doi:10.1080/00036846.2014.916394S298229924624Anderson, J. E., & van Wincoop, E. (2003). Gravity with Gravitas: A Solution to the Border Puzzle. American Economic Review, 93(1), 170-192. doi:10.1257/000282803321455214Bergstrand, J. H. (1985). The Gravity Equation in International Trade: Some Microeconomic Foundations and Empirical Evidence. The Review of Economics and Statistics, 67(3), 474. doi:10.2307/1925976Bergstrand, J. H. (1989). The Generalized Gravity Equation, Monopolistic Competition, and the Factor-Proportions Theory in International Trade. The Review of Economics and Statistics, 71(1), 143. doi:10.2307/1928061De Souza, R., Goh, M., Gupta, S.et al.(2007) An investigation into the measures affecting the integration of ASEAN’s priority sectors: phase 2: the case of logistics.REPSF ProjectNo. 06/001d Regional Economic Policy Support Facility, Association of Southeast Asian Nations, Manila.Heckman, J. J. (1979). Sample Selection Bias as a Specification Error. Econometrica, 47(1), 153. doi:10.2307/1912352Hoekman, B., & Nicita, A. (2010). Assessing the Doha Round: Market access, transactions costs and aid for trade facilitation. The Journal of International Trade & Economic Development, 19(1), 65-79. doi:10.1080/09638190903327476Iwanow, T., & Kirkpatrick, C. (2009). Trade Facilitation and Manufactured Exports: Is Africa Different? World Development, 37(6), 1039-1050. doi:10.1016/j.worlddev.2008.09.014Marti, L., Puertas, R., & García, L. (2012). Relevance of trade facilitation in emerging countries’ exports. The Journal of International Trade & Economic Development, 23(2), 202-222. doi:10.1080/09638199.2012.698639Martínez-Zarzoso, I., & Suárez-Burguet, C. (2000). The determinants of trade performance: influence of R&D on export flows. Applied Economics, 32(15), 1939-1946. doi:10.1080/00036840050155869Mustra, M. A. (2011) Logistic Performance Index, connecting to compete 2010, inUNESCAP Regional Forum and Chief Executives Meeting, The World Bank, Cairo
Corrections to Nambu-Goto energy levels from the effective string action
The effective action on long strings, such as confining strings in pure
Yang-Mills theories, is well-approximated by the Nambu-Goto action, but this
action cannot be exact. The leading possible corrections to this action (in a
long string expansion in the static gauge), allowed by Lorentz invariance, were
recently identified, both for closed strings and for open strings. In this
paper we compute explicitly in a Hamiltonian formalism the leading corrections
to the lowest-lying Nambu-Goto energy levels in both cases, and verify that
they are consistent with the previously computed effective string partition
functions. For open strings of length R the leading correction is of order
1/R^4, for excited closed strings of length R in D>3 space-time dimensions it
is of order 1/R^5, while for the ground state of the closed string in any
dimension it is of order 1/R^7. We attempt to match our closed string
corrections to lattice results, but the latter are still mostly outside the
range of convergence of the 1/R expansion that we use.Comment: 18 pages, 1 figure, JHEP format. v2: added remark on 1/R^7
corrections to ground state energ
Моксифлоксацин (авелокс) в сравнении с комбинацией "офлоксацин плюс метронидазол" при неосложненных воспалительных заболеваниях органов малого таза. Результаты многоцентрового, двойного слепого, рандомизированного клинического исследования
ЖЕНСКИЕ БОЛЕЗНИ /ЛЕК ТЕРМОКСИФЛОКСАЦИНАВЕЛОКСОФЛОКСАЦИНМЕТРОНИДАЗО
Use of archival versus newly collected tumor samples for assessing PD-L1 expression and overall survival : an updated analysis of KEYNOTE-010 trial
Background: In KEYNOTE-010, pembrolizumab versus docetaxel improved overall survival (OS) in patients with programmed death-1 protein (PD)-L1-positive advanced non-small-cell lung cancer (NSCLC). A prespecified exploratory analysis compared outcomes in patients based on PD-L1 expression in archival versus newly collected tumor samples using recently updated survival data.
Patients and methods: PD-L1 was assessed centrally by immunohistochemistry (22C3 antibody) in archival or newly collected tumor samples. Patients received pembrolizumab 2 or 10 mg/kg Q3W or docetaxel 75 mg/m2 Q3W for 24 months or until progression/intolerable toxicity/other reason. Response was assessed by RECIST v1.1 every 9 weeks, survival every 2 months. Primary end points were OS and progression-free survival (PFS) in tumor proportion score (TPS) 50% and 1%; pembrolizumab doses were pooled in this analysis.
Results: At date cut-off of 24 March 2017, median follow-up was 31 months (range 23-41) representing 18 additional months of follow-up from the primary analysis. Pembrolizumab versus docetaxel continued to improve OS in patients with previously treated, PD-L1-expressing advanced NSCLC; hazard ratio (HR) was 0.66 [95% confidence interval (CI): 0.57, 0.77]. Of 1033 patients analyzed, 455(44%) were enrolled based on archival samples and 578 (56%) on newly collected tumor samples. Approximately 40% of archival samples and 45% of newly collected tumor samples were PD-L1 TPS 50%. For TPS 50%, the OS HRs were 0.64 (95% CI: 0.45, 0.91) and 0.40 (95% CI: 0.28, 0.56) for archival and newly collected samples, respectively. In patients with TPS 1%, OS HRs were 0.74 (95% CI: 0.59, 0.93) and 0.59 (95% CI: 0.48, 0.73) for archival and newly collected samples, respectively. In TPS 50%, PFS HRs were similar across archival [0.63 (95% CI: 0.45, 0.89)] and newly collected samples [0.53 (95% CI: 0.38, 0.72)]. In patients with TPS 1%, PFS HRs were similar across archival [0.82 (95% CI: 0.66, 1.02)] and newly collected samples [0.83 (95% CI: 0.68, 1.02)].
Conclusion: Pembrolizumab continued to improve OS over docetaxel in intention to treat population and in subsets of patients with newly collected and archival samples
Correlation functions in super Liouville theory
We calculate three- and four-point functions in super Liouville theory
coupled to super Coulomb gas on world sheets with spherical topology. We first
integrate over the zero mode and assume that a parameter takes an integer
value. After calculating the amplitudes, we formally continue the parameter to
an arbitrary real number. Remarkably the result is completely parallel to the
bosonic case, the amplitudes being of the same form as those of the bosonic
case.Comment: 11 page
Polyakov loop correlators from D0-brane interactions in bosonic string theory
In this paper we re-derive the effective Nambu-Goto theory result for the
Polyakov loop correlator, starting from the free bosonic string and using a
covariant quantization. The boundary conditions are those of an open string
attached to two D0-branes at spatial distance R, in a target space with compact
euclidean time. The one-loop free energy contains topologically distinct
sectors corresponding to multiple covers of the cylinder in target space
bordered by the Polyakov loops. The sector that winds once reproduces exactly
the Nambu-Goto partition function. In our approach, the world-sheet duality
between the open and closed channel is most evident and allows for an explicit
interpretation of the free energy in terms of tree level exchange of closed
strings between boundary states. Our treatment is fully consistent only in
d=26; extension to generic d may be justified for large R, and is supported by
Montecarlo data. At shorter scales, consistency and Montecarlo data seem to
suggest the necessity of taking into account the Liouville mode of Polyakov's
formulation.Comment: 17 pages, 4 figures, minor corrections, a few references added,
version accepted for publication in JHE
Quark mass correction to the string potential
A consistent method for calculating the interquark potential generated by the
relativistic string with massive ends is proposed. In this approach the
interquark potential in the model of the Nambu--Goto string with point--like
masses at its ends is calculated. At first the calculation is done in the
one--loop approximation and then the variational estimation is performed. The
quark mass correction results in decreasing the critical distance
(deconfinement radius). When quark mass decreases the critical distance also
decreases. For obtaining a finite result under summation over eigenfrequencies
of the Nambu--Goto string with massive ends a suitable mode--by--mode
subtraction is proposed. This renormalization procedure proves to be completely
unique. In the framework of the developed approach the one--loop interquark
potential in the model of the relativistic string with rigidity is also
calculated.Comment: 34 pages, LATE
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