Bootstrapping Cointegrating Regressions

In this paper, we consider bootstrapping cointegrating regressions. It is shown that the method of bootstrap, if properly implemented, generally yields consistent estimators and test statistics for cointegrating regressions. We do not assume any specific data generating process, and employ the sieve bootstrap based on the approximated finite-order vector autoregressions for the regression errors and the firrst differences of the regressors. In particular, we establish the bootstrap consistency for OLS method. The bootstrap method can thus be used to correct for the finite sample bias of the OLS estimator and to approximate the asymptotic critical values of the OLS-based test statistics in general cointegrating regressions. The bootstrap OLS procedure, however, is not efficient. For the efficient estimation and hypothesis testing, we consider the procedure proposed by Saikkonen (1991) and Stock and Watson (1993) relying on the regression augmented with the leads and lags of differenced regressors. The bootstrap versions of their procedures are shown to be consistent, and can be used to do inferences that are asymptotically valid. A Monte Carlo study is conducted to investigate the finite sample performances of the proposed bootstrap methods.

How the pine seeds attach to/detach from the pine cone scale?

One of the primary purposes of pine cones is the protection and distant dispersal of pine seeds. Pine cones open and release their embedded seeds on dry and windy days for long-distance dispersal, In this study, how the pine seeds attach to/detach from the pine cone scale for efficient seed dispersal was experimentally investigated by using an X-ray micro-imaging technique. The cone and seeds adhere to each other in the presence of water, which could be explained by the surface tension and the contact angle hysteresis, Otherwise, without water, the waterproof seed wing surface permits rapid drying for detach and dispersion, On the other hand, during wildfires, pine cones open their seed racks and detach the pine seeds from pine cones for rapid seed dispersal. Due to these structural advantages, pine seeds are released safely and efficiently in normal conditions. These advantageous structures could be mimicked,in practical applications.1110Ysciescopu

Effects of Direct-fed Microbial and Pine Cone Extract on Carcass Traits and Meat Quality of Hanwoo (Korean Native Cattle)

The carcass traits and meat quality of Hanwoo (Korean native cattle) whose diets were supplemented with direct-fed microbial (DFM) and pine cone extract (PCE) were evaluated. Twenty head of Hanwoo steers were divided equally into four groups and for a period of 6 months were given different diets: One group was fed a basal diet as control (CON), the other three groups were fed a basal diet supplemented with DFM-1%, DFM+PCE-1% and DFM+PEC-3%, respectively. DFM+PCE3% diet resulted the lowest carcass quality grade. The loins of DFM-1% contained higher moisture and lower fat than did the loins from the CON group. The crude protein content of DFM+PCE-3% group was significantly higher than that of the other groups. The water holding capacity and Warner-Bratzler shear force of the DFM+PCE-1% and 3% groups were lower than those of the CON and DFM-1% groups. The DFM-1% and 3% groups contained lower saturated fatty acid, higher unsaturated fatty acid, mono-unsaturated fatty acid, and poly-unsaturated fatty acid than did CON and DFM+PCE 1% group. Moreover, the n6:n3 ratios of DFM-1% and DFM+PCE-1% and 3% groups were slightly lower than that of the CON group. Thus we concluded that DFM and PCE supplementation resulted healthier Hanwoo beef with lower fat content and n6:n3 ratio

In vitro antioxidant and anti-adipogenic effects of slendesta, standard potato extracts containing 5% protease inhibitor II

Background: The objective of the present study is to observe the anti-adipogenic effects of Slendesta (SLD), a standard potato protein extracts containing 5% potato protease inhibitor II (PI2) on the 3T3-L1 preadipocytes which are able to differentiate into mature adipocytes and accumulate lipids, as an obesity model with cytotoxicity and antioxidant effects.Materials and Methods: The cytotoxicity of SLD was observed against 3T3-L1 preadipocyte cell line by MTT assay, and also antiadipogenic effects were observed through lipid accumulation assay during 3T3-L1 differentiation as comparing with N-Acetyl-Lcysteine (NAC). In addition, antioxidant effects of SLD were detected by free radical scavenging capacity and superoxide dismutase (SOD)-like activity as comparing with ascorbic acid.Results: The SLD showed obvious cytotoxicity against 3T3-L1 pre-adipocyte cell line at higher concentrations, from 1.5 mg/ml for 72 h treatment, and the cytotoxic IC50 of SLD after 24, 48 and 72 h treatment times were detected as 10.11 ± 0.67, 5.71 ± 0.37 and 5.34 ± 0.21 mg/ml, respectively. The SLD also concentration-dependently inhibited the lipid accumulations formatted during 3T3-L1 cell differentiations. The adipogenic specific genes including PPARγ, C/EBPα, C/EBPβ and leptin were found to be reduced in SLD and NAC-treated cells compared to control cells. Furthermore, the SLD effectively showed DPPH radical scavenging activity (IC50 = 161.98 ± 64.65 μg/ml) and SOD-like effects (IC50 = 284.54 ± 54.47 μg/ml), and the cellular ROS was significantly inhibited in the SLD-treated cells compared to control cells.Conclusion: The results suggest that SLD effectively inhibit the differentiations of 3T3-L1 preadipose cell probably through antioxidant activities and direct cytotoxicity in case of higher concentration, along with satiety effects mediated by increases of circulating cholecystokinin. These findings are considered as direct evidences that SLD may serve as a predictable functional ingredient for obesity as an alternative therapy.Key words: Slendesta, potato protease inhibitor II, 3T3-L1 cell, cytotoxicity, anti-adipogenic effects, antioxidant effects

Expression patterns of influenza virus receptors in the respiratory tracts of four species of poultry

The primary determinant of influenza virus infectivity is the type of linkage between sialic acid and oligosaccharides on the host cells. Hemagglutinin of avian influenza viruses preferentially binds to sialic acids linked to galactose by an α-2,3 linkage whereas hemagglutinin of human influenza viruses binds to sialic acids with an α-2,6 linkage. The distribution patterns of influenza receptors in the avian respiratory tracts are of particular interest because these are important for initial viral attachment, replication, and transmission to other species. In this study, we examined the distribution patterns of influenza receptors in the respiratory tract of chickens, ducks, pheasants, and quails because these species have been known to act as intermediate hosts in interspecies transmission. Lectin histochemistry was performed to detect receptor-bearing cells. Cell-specific distribution of the receptors was determined and expression densities were compared. We observed species-, site-, and cell-specific variations in receptor expression. In general, receptor expression was the highest in quails and lowest in ducks. Pheasants and quails had abundant expression of both types of receptors throughout the respiratory tract. These results indicate that pheasants and quails may play important roles as intermediate hosts for the generation of influenza viruses with pandemic potential

A Novel Meatoplasty Method in Canal Wall Down Tympanomastoidectomy: A Perichondrial Posterior Fixation Technique

ObjectivesAlthough it is well recognized that a small meatus after canal wall down (CWD) tympanomastoidectomy can cause a lifetime problem, unsatisfactory results are frequently encountered. We herein introduce a novel technique, perichondrial posterior fixation (PPF), to maintain a wide external auditory canal (EAC), to minimize postoperative wound infection due to the smaller dead space and to improve the posterior auricular cosmetic outcome.MethodsA total of 73 patients who underwent CWD tympanomastoidectomy were included. Interventions are CWD tympanomastoidectomy with the PPF technique. Review of the medical records and evaluation of the postoperative size of the meatus and the extent of the cavum conchal cartilage buried within the mastoid cavity by taking digital photographs.ResultsThirty males and 43 females were included and the mean age was 44.1 yr (range, 6 to 66 yr). The mean follow-up duration was 26 months (range, 12 to 56 months). All ears maintained a clean and large external meatus. The posterior auricular cavum conchal cartilage was successfully prevented from being buried into the mastoid cavity in all ears. The extent of cartilage buried into the mastoid cavity was much reduced compared to the conventional technique.ConclusionThe PPF technique, which is a novel meatoplasty technique in CWD tympanomastoidectomy, seems to be effective in maintaining a large external meatus and improving the cosmetic outcome with minimal risk of complications

Lower-Tropospheric Enhancement of Gravity Wave Drag in a Global Spectral Atmospheric Forecast Model

ABSTRACT The impacts of enhanced lower-tropospheric gravity wave drag induced by subgrid-scale orography on short-and medium-range forecasts as well as seasonal simulations are examined. This study reports on the enhanced performance of the scheme proposed by Kim and Arakawa, which has been used in the National Centers for Environmental Prediction (NCEP) Global Spectral Model since 1997. The performance is evaluated against a traditional upper-level drag scheme that is also available in the model. The experiment results reveal that the Kim-Arakawa scheme improves the movement and intensity of an extratropical cyclone and a continental high pressure system that was accompanied by heavy snowfall over Korea on 14-15 February 2001. The monthly verification for medium-range forecasts in December 2006, which are initialized by the NCEP operational analysis, demonstrates overall improvements in the forecasts of largescale fields in the Northern Hemisphere. Moderate improvements are also found in the seasonal simulation of December-February for the years 1996/97, 1997/98, and 1999/2000. This study concludes that the enhanced lower-level drag should be properly parameterized in global atmospheric models for numerical weather prediction and seasonal prediction