1,845 research outputs found
Indo-Pacific development and stability as context for Taiwan's New Southbound Policy
For more about the East-West Center, see http://www.eastwestcenter.org/Michael Hsiao, Executive Director of the Taiwan-Asia Exchange Foundation, explains that "[For Taiwan] the stability of regional order are in line with national interests.
Estimation and Inference In Short Panel Vector Autoregressions with Unit Roots And Cointegration
This paper considers estimation and inference in panel vector autoregressions (PVARs) with fixed effects when the time dimension of the panel is finite, and the cross-sectional dimension is large. A Maximum Likelihood (ML) estimator based on a transformed likelihood function is proposed and shown to be consistent and asymptotically normally distributed irrespective of the unit root and cointegrating properties of the underlying PVAR model. The transformed likelihood framework is also used to derive unit root and cointegration tests in panels with short time dimension; these tests have the attractive feature that they are based on standard chi-square and normal distributed statistics. Examining Generalized Method of Moments (GMM) estimation as an alternative to our proposed ML estimator, it is shown that conventional GMM estimators based on standard orthogonality conditons break down if the underlying time series contain unit roots. Also, the implementation of extended GMM estimators making use of variants of homoskedasticity and stationarity restrictions as suggested in the literature in a univariate context is subject to difficulties. Monte Carlo evidence is adduced suggesting that the ML estimator and parameter hypothesis and cointegration tests based on it perform well in small sample; this is in marked contrast to the small sample performance of the GMM estimators.Panel vector autoregressions, fixed effects, unit roots, cointegration
"Estimating the Impact of Whaling on Global Whale Watching"
After the commercial whaling moratorium was enacted in 1986, whale watching became one of the fastest growing tourism industries worldwide. As whaling was regarded as an activity incompatible with whale watching, the possible resumption of commercial whaling caused an urgent need to investigate the potential negative effects of whaling on the whale-watching industry. We examine the potential impacts of whaling on the global whale-watching tourism industry using unbalanced panel data model. The empirical results indicate that the resumption of commercial whaling has the potential for a negative effect on the global whale-watching industry, especially for nations that are engaged in whaling.
HST Detection of Extended Neutral Hydrogen in a Massive Elliptical at z = 0.4
We report the first detection of extended neutral hydrogen (HI) gas in the
interstellar medium (ISM) of a massive elliptical galaxy beyond z~0. The
observations utilize the doubly lensed images of QSO HE 0047-1756 at z_QSO =
1.676 as absorption-line probes of the ISM in the massive (M_star ~ 10^11
M_sun) elliptical lens at z = 0.408, detecting gas at projected distances of d
= 3.3 and 4.6 kpc on opposite sides of the lens. Using the Space Telescope
Imaging Spectrograph (STIS), we obtain UV absorption spectra of the lensed QSO
and identify a prominent flux discontinuity and associated absorption features
matching the Lyman series transitions at z = 0.408 in both sightlines. The HI
column density is log N(HI) = 19.6-19.7 at both locations across the lens,
comparable to what is seen in 21 cm images of nearby ellipticals. The HI gas
kinematics are well-matched with the kinematics of the FeII absorption complex
revealed in ground-based echelle data, displaying a large velocity shear of 360
km/s across the galaxy. We estimate an ISM Fe abundance of 0.3-0.4 solar at
both locations. Including likely dust depletions increases the estimated Fe
abundances to solar or supersolar, similar to those of the hot ISM and stars of
nearby ellipticals. Assuming 100% covering fraction of this Fe-enriched gas,we
infer a total Fe mass of M_cool(Fe)~(5-8)x10^4 M_sun in the cool ISM of the
massive elliptical lens, which is no more than 5% of the total Fe mass observed
in the hot ISM.Comment: 6 pages, 2 figures; Accepted for publication in ApJ Letter
Estimating the Impact of Whaling on Global Whale Watching
After a commercial whaling moratorium was enacted in 1986, whale watching became one of the fastest growing tourism industries worldwide. As whaling is regarded as an activity that is incompatible with whale watching, the possible resumption of commercial whaling has caused an urgent need to investigate the potential negative effects of whaling on the whale-watching industry. We examine the potential impacts of whaling on the global whale-watching tourism industry using an unbalanced panel data model. The empirical results indicate that the resumption of commercial whaling has the potential for a negative effect on the global whale-watching industry, especially for nations that are engaged in whaling.Global whale watching; Commercial whaling; Delay-difference equation model; Unbalanced panel data model
Electric-Field-Directed Self-Assembly of Active Enzyme-Nanoparticle Structures
A method is presented for the electric-field-directed self-assembly of higher-order structures composed of alternating layers of biotin nanoparticles and streptavidin-/avidin-conjugated enzymes carried out on a microelectrode array device. Enzymes included in the study were glucose oxidase (GOx), horseradish peroxidase (HRP), and alkaline phosphatase (AP); all of which could be used to form a light-emitting microscale glucose sensor. Directed assembly included fabricating multilayer structures with 200 nm or 40 nm GOx-avidin-biotin nanoparticles, with AP-streptavidin-biotin nanoparticles, and with HRP-streptavidin-biotin nanoparticles. Multilayered structures were also fabricated with alternate layering of HRP-streptavidin-biotin nanoparticles and GOx-avidin-biotin nanoparticles. Results showed that enzymatic activity was retained after the assembly process, indicating that substrates could still diffuse into the structures and that the electric-field-based fabrication process itself did not cause any significant loss of enzyme activity. These methods provide a solution to overcome the cumbersome passive layer-by-layer assembly methods to efficiently fabricate higher-order active biological and chemical hybrid structures that can be useful for creating novel biosensors and drug delivery nanostructures, as well as for diagnostic applications
The Dirty War Index: A Public Health and Human Rights Tool for Examining and Monitoring Armed Conflict Outcomes
Madelyn Hsiao-Rei Hicks and Michael Spagat introduce the "Dirty War Index," a public health tool that identifies rates of undesirable or prohibited war outcomes inflicted on populations during armed conflict
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