A kinetic study on the lime-heat treatment of corn for masa production

An objective method to predict the optimum cooking time of corn for tortilla production does not exist. Since nixtamalization (lime-heat treatment) is the most important step in the preparation of tortillas, the changes in the corn kernel during this period should be analyzed for the development of an optimal tortilla-making process. This study presents a mathematical model for quantitatively analyzing the kinetics of water diffusion and starch gelatinization during the nixtamalization process;Corn was cooked with and without calcium hydroxide, according to traditional processing steps. The temperature of the cooking solution, the amount of water absorbed by the corn, and the extent of starch gelatinization in the corn were monitored throughout the process. The data were quantitatively analyzed using the mathematical model that was developed based on the principles of diffusion and chemical reaction kinetics. The simplex pattern search scheme was used to locate the optimum rate parameters, which were used to calculate the extent of starch gelatinization. The calculated degree of gelatinization was then compared with that experimentally determined;The result shows that the developed mathematical model is useful for simulating the changes that take place during water-cooking and lime-cooking of corn. The calculated degree of starch gelatinization in corn, based on the quantitative analysis of water uptake data, was highly correlated with those data experimentally determined;Comparison among the responses of nine cultivars of corn to lime-heat treatment showed that the sensitivity of the diffusion process and of the gelatinization reaction to temperature change was the same for the nine corn samples studied. The results also show that the values of diffusivity, D[subscript]0, and the reaction rate constant, K[subscript]0, determine the differences in water uptake and starch gelatinization among samples;According to the stickiness values of masa, the range of degree of starch gelatinization for the preparation of suitable masa dough was between 14 and 20%. Twenty to 30 min cooking time for the sample studied was found to produce this degree of starch gelatinization

Toward Sovereignty: Zhang Zhidong’s Military Strengthening of China, 1884-1901

The conventional history of China’s late nineteenth-century Self-Strengthening movement charted a failure of military reforms. My research explores this period through the perspective of the prominent governor-general Zhang Zhidong. From 1884-1901, Zhang consistently pursued new military academies and western-style armies aiming to secure the nation against foreign imperialist incursion. At the same time, the governor’s understanding of regional differences as well as his increasing experience in military affairs distinctly shaped his effective new military institutions. At the turn of the century, Zhang Zhidong’s military apparatus was arguably one of the best in China. In the wider analysis of Chinese military history, the governor’s career contrasted with other historical figures by its peripatetic nature and its continuity through the Sino-Japanese War and Boxer Rebellion. Zhang’s many jurisdictions showed not only his consistent dedication to military power as a means to national sovereignty, but also created numerous military institutions for study. More importantly, the continuity in the governor’s effective military reforms underlined fundamental historical misunderstandings about the nature of late-Qing China. First, Zhang’s successful military institutions contended with China’s deterioration narrative from 1895 to the dynastic fall in 1911. Second, the reason for historical misinterpretation stemmed from the obscuring of both late-Qing historians’ and the historical actors’ perceptions by the influences of western imperialism. Ultimately, the study of Zhang Zhidong’s military reforms shows a discontinuity in the conventional historical narrative, and thus creates space for increased Chinese agency in their own history

Supply Chain Efficiency Analysis: A Theoretical Approach

We divide the supply chain into a central control system (CCS) case and a decentralized control system (DCS) case, and compare the supply chain efficiency with both the CCS case and the DCS case.  We find that the supply chain efficiency of a capital-intensive industry is better under the CCS case than under the DCS case.  Under the CCS case, the maximized supply chain efficiency can be reached by choosing either the lowest price that the upstream firm is willing to receive or the highest price that the downstream firm is willing to pay for intermediate goods

Are Moving Average Trading Rules Profitable? Evidence From The Mexican Stock Market

This paper tests three moving average technical trading rules for the Mexican Stock Market. Results indicate that moving average rules do indeed have predictive power and can discern recurring-price patterns for profitable trading and support the hypothesis that technical trading rules can outperform the buy-and-hold strategy. Break-even one-way trading costs are estimated to be in the range of 1% to 3% over the period under consideration. These break-even costs, we believe, are large compared to recent estimates of actual trading costs, implying that moving average trading rules have predictive power and can generate consistent profits even after transaction costs are considered

Variations in high density cholesterol levels based on apolipoprotein E variant and exercise type

In various cross-sectional and longitudinal studies, exercise has been associated with cardiometabolic outcomes, including high-density lipoprotein (HDL) cholesterol. Exercise-induced changes in HDL cholesterol seem to be affected by genetic polymorphisms. In this study, we examined whether variant APOE rs7412 is involved in the association between HDL cholesterol and exercise. From adults assessed in Taiwan Biobank (TWB) between 2008 and 2019, we analyzed data from 57,638 normolipidemic subjects. To examine the association between exercise, APOE rs7412, and HDL cholesterol, a multiple linear regression model was used. A higher HDL was associated with both aerobic exercise (regression coefficient [mg/dL] beta- (β), 1.112; 95% confidence interval (CI); 0.903–1.322) and resistance exercise (β, 2.530; 95% CI, 2.093–2.966). In comparison with the APOE rs7412-CC genotype, the β was 2.589 (95% CI, 2.329–2.848) among those with the CT + TT genotype. Compared to adults who had the CC genotype and did not exercise (the CC/no exercise group), the β-coefficient determined for the different genotype and exercise groups was 1.135 (95% CI, 0.911–1.359) for the CC genotype and aerobic exercise group, 2.753 (95% CI, 2.283–3.322) for the CC genotype and resistance exercise group, 2.705 (95% CI, 2.390–3.020) for the CT + TT genotype and no exercise group, 3.682 (95% CI, 3.218–4.146) for the CT + TT genotype and aerobic exercise group, and 3.855 (95% CI, 2.727–4.982) for the CT + TT genotype and resistance exercise group, respectively. This study demonstrates that self-reported aerobic and resistance exercise both raised HDL levels, yet resistance exercise was associated with a greater increase, particularly among Taiwanese subjects carrying the APOE rs7412-CT+TT genotype

Polymorphism rs3733591 of the SLC2A9 gene and metabolic syndrome affect gout risk in Taiwan Biobank subjects

Background:Over the past few decades, gout and diseases like metabolic syndrome (MetS) have become more prevalent. Attempts have been made in Taiwan to identify the genes responsible for gout. A few gene loci, among them SLC2A9, have been identified using Taiwan Biobank (TWB) data. We, therefore, examined whether MetS could also account for the association between polymorphism SLC2A9 rs3733591 and gout.Methods:The final analysis consisted of 73,558 subjects, of whom 2,709 had gout. To estimate the likelihood of gout occurrence based on rs3733591 and MetS, we used logistic regression models.Results:Rs3733591-TC + CC compared to TT genotype was associated with gout (OR, 1.15; 95% CI, 1.06–1.25). Also associated with gout was MetS (OR, 1.21; 95% CI, 1.10–1.33). A significant interaction was seen between rs3733591 and MetS (p-value = 0.039). Using rs3733591-TT/no MetS as the reference group, the ORs (95% CI) for gout was 1.24 (1.11–1.38) for TC + CC/no MetS, 1.35 (1.17–1.56) for TT/MetS, and 1.39 (1.22–1.58) for TC + CC/MetS. However, subgroup analysis defined by sex showed no significant associations in women.Conclusion:In summary, metabolic syndrome and SLC2A9 rs3733591 genotypes were interactively associated with gout in Taiwanese men, but not women

Deer Antler Extract Improves Fatigue Effect through Altering the Expression of Genes Related to Muscle Strength in Skeletal Muscle of Mice

Deer antler is a well-known traditional Chinese medicine used in Asian countries for the tonic and the improvement of aging symptoms. The present study was designed to investigate the antifatigue effect and mechanism of Formosan sambar deer tip antler extract (FSDTAE). The swimming times to exhaustion of mice administered FSDTAE (8.2 mg/day) for 28 days were apparently longer than those of the vehicle-treated mice in forced swim test. However, the indicators of fatigue, such as the reduction in glucose level and the increases in blood urea nitrogen and lactic acid levels, were not significantly inhibited by FSDTAE. Therefore, microarray analysis was further used to examine the anti-fatigue mechanism of FSDTAE. We selected genes with fold changes >2 or <−2 in skeletal muscle for pathway analysis. FSDTAE-affected genes were involved in 9 different signaling pathways, such as GnRH signaling pathway and insulin signaling pathway. All of the significantly expressed genes were classified into 8 different categories by their functions. The most enriched category was muscular system, and 6 upregulated genes, such as troponin I, troponin T1, cysteine and glycine-rich protein 2, myosin heavy polypeptide 7, tropomyosin 2, and myomesin family member 3, were responsible for the development and contraction of muscle. Real-time PCR analysis indicated that FSDTAE increased troponins mRNA expression in skeletal muscle. In conclusion, our findings suggested that FSDTAE might increase the muscle strength through the upregulation of genes responsible for muscle contraction and consequently exhibited the anti-fatigue effect in mice

Benthic Fluxes of Dissolved Organic Carbon from Gas Hydrate Sediments in the Northern South China Sea

Hydrocarbon vents have recently been reported to contribute considerable amounts of dissolved organic carbon (DOC) to the oceans. Many such hydrocarbon vents widely exist in the northern South China Sea (NSCS). To investigate if these hydrocarbon vent sites release DOC, we used a real-time video multiple-corer to collect bottom seawater and surface sediments at vent sites. We analyzed concentrations of DOC in these samples and estimated DOC fluxes. Elevated DOC concentrations in the porewaters were found at some sites suggesting that DOC may come from these hydrocarbon vents. Benthic fluxes of DOC from these sediments were 28 to 1264 µmol m−2 d−1 (on average ~321 µmol m−2 d−1 which are several times higher than most DOC fluxes in coastal and continental margin sediments. The results demonstrate that the real-time video multiple-corer can precisely collect samples at vent sites. The estimated benthic DOC flux from the methane venting sites (8.6 x 106 mol y-1, is 24% of the DOC discharge from the Pearl River to the South China Sea, indicating that these sediments make an important contribution to the DOC in deep waters

Recurrent disturbances and the degradation of hard coral communities in Taiwan

Recurrent disturbances can have a critical effect on the structure and function of coral reef communities. In this study, long-term changes were examined in the hard coral community at Wanlitung, in southern Taiwan, between 1985 and 2010. In this 26 year interval, the reef has experienced repeated disturbances that include six typhoons and two coral-bleaching events. The frequency of disturbance has meant that species susceptible to disturbance, such as those in the genus Acropora and Montipora have almost disappeared from the reef. Indeed, almost all hard coral species have declined in abundance, with the result that total hard coral cover in 2010 (17.7%) was less than half what it was in 1985 (47.5%). In addition, macro-algal cover has increased from 11.3% in 2003 to 28.5% in 2010. The frequency of disturbance combined with possible chronic influence of a growing human population mean that a diverse reef assemblage is unlikely to persist on this reef into the future