Lower Trend Research Articles

CLIMATE CHANGE TRENDS IN THE RED RIVER DELTA

The Red River Delta (RRD) is one of the regions most significantly impacted by climate change (CC) in Vietnam. This study utilizes correlation assessment methods and regression equations to evaluate the trends of certain meteorological factors and extreme weather events during the period 1961 - 2020 in the RRD. Overall, climate factors across the region exhibit quite clear trends of change. The highest trends in annual average temperature and maximum annual average temperature are observed in the northwestern part of the RRD, especially in major cities such as Ha Noi (the increase in mean annual temperature ranges from 0.0317 - 0.0336 ºC/year). The lowest trends in these temperatures are found in coastal, island, and mountainous areas (the increase in mean annual temperature ranges from 0.0133 - 0.0224 ºC/year). The annual rainfall reports a decreasing trend at 17 out of 23 meteorological stations in the RRD, varying from -11 to 9 mm/year. Extreme weather phenomena report little significant change, with maximum daily rainfall records a decreasing trend, varying from -3.119 to 1.395 mm/year; the number of days with rainfall exceeding 50 mm also reports a decrease, varying from -0.058 to 0.017 days/year. The results of this study will serve as a basis for developing action plans to respond to CC in the RRD.

Design of remote sensing image feature extraction method based on high score 2 wavelet transform

The feature extraction of Gaofen-2 Remote Sensing Image (RSI) has problems such as poor extraction accuracy and large noise reduction error. Therefore, this paper designs an RSI feature extraction method based on high score 2 wavelet transform (WT). The RSI is collected with the help of Gaofen-2 satellite and high-resolution remote sensing technology, the key points of the image are determined through the Gaussian difference scale space, and the key points of the edge are judged by the peak curvature value of the difference function at the edge junction, so as to complete the RSI acquisition. Specific filtering and spatial domain transformations are used to remove image noise and improve the quality of RSI. The mean shift (MS) algorithm is used to iteratively find the area with the most dense sample points in the RSI space, complete the image analysis, and realize the preprocessing of the high score 2 RSI. The linear features of the RSI are determined by the WT algorithm, and the image threshold is set for feature extraction of the high score 2 RSI. The experimental results show that in the RSI noise reduction error analysis of different methods, the noise reduction error curve of the sample RSI of the method proposed in this paper has the lowest trend, which is always lower than 2%. Compared with the two methods proposed before, the error is higher. At the same time, in the accuracy analysis of key point feature extraction, the proposed scheme has better accuracy. Therefore, it can be seen that this method has better comprehensive performance, and the proposed method can effectively improve the feature extraction accuracy of RSI and reduce the noise in RSI.

Analysis of corrosion inhibition of Kleinhovia hospita plant extract aided by quantification of hydrogen evolution using a GLCM/SVM method

During a corrosion inhibition test, a combination of common electrochemical corrosion test methods with an in-situ quantification of H2 evolution could provide a comprehensive analysis of the effectiveness of an organic inhibitor. This work analyzes the corrosion inhibition efficiency of Kleinhovia hospita plant extract on carbon steel specimens polarized in 1 M HCl, based on acquired H2 bubbles images, by using gray level co-occurrence matrix (GLCM) and support vector machine (SVM) classification. A conformity was established between the classified-algorithm models and the corrosion test results obtained by potentiodynamic polarization test and electrochemical impedance spectroscopy. Hydrogen rate and corrosion rate show the same lowest trends at the addition of 3000 mg/L of KH extract. The inhibitor addition led to 99% of maximum inhibition efficiency. Based on the polarization data, KH extract is a mixed type inhibitor. Supported by Langmuir calculation for adsorption isotherm, a physisorption is stated as the main inhibition mechanism. The feature extraction using GLCM was able to distinguish changes in H2 bubbles characteristics where the addition of inhibitor affected the corrosion rate. The GLCM/SVM method applied as a linear kernel function and showed 88% accuracy with d = 5 for image data testing. Remarkable changes in H2 gas bubbles characteristic were observed in the specimen immersed in the solution with 3000 mg/L inhibitor addition, signified by 99% inhibition efficiency.

CORRELATION OF ANKLE-BRACHIAL INDEX WITH SEVERITY OF CORONARY ARTERY DISEASE IN PATIENTS HOSPITALIZED FOR ACUTE MYOCARDIAL INFARCTION

Objective: Ankle-brachial index (ABI) is an stablished predictor of cardiovascular events in different clinical setting including hypertension Purpose: To assess the usefulness of ABI evaluation for identifying multivessel CAD in patients with acute myocardial infraction (AMI). Design and method: We studied 101 patients [77.2% male; mean age 60.9 years; 63.4% hypertensives; 24.8% with diabetes mellitus (DM)] who were hospitalized because of ST-elevation MI (STEMI, 51.5%) and Non-ST–elevation MI (NSTEMI). All patients underwent baseline estimation of clinical and laboratory parameters during their hospitalization. The ABI was measured according to established methodology using a certified automated device and abnormal ABI was defined as a value <0.9. Severity of CAD was estimated by the number of affected main vessels. Results: In the entire population, mean ABI was 1.11 ± 0.17, while 15.8% of patients had abnormal ABI. NSTEMI patients compared to those with STEMI demonstrated a trend forlower ABI (1.07 ± 0.18 vs 1.12 ± 0.16; p = 0.144) and more often abnormal ABI (22.4% vs 9.6%; p = 0.103). Using univariate analysis in the entire population, severity of CAD was correlated with age (r = 0.133; p = 0.053), history of DM (r = 0.225; p = 0.01), ABI value (r = 0.214; p = 0.029) and abnormal ABI (r = 0.242; p = 0.015). In multivariate regression models, both ABI value (b = 0.258; p = 0.014) and abnormal ABI (b = 0.218; p = 0.036) remained significant predictors of CAD severity independently of gender, age, DM, smoking, low density lipoprotein (LDL-C), 24-h systolic blood pressure and the type of MI. Conclusions: An impaired ABI is associated with greater risk of multivessel CAD in patients with AMI. This finding in patients with acute coronary syndromes may thusraise the suspicion of advanced disease, alerting to the need for moreaggressive diagnostic and therapeutic strategies.

SNOW COVER AREA ANALYSIS AND ITS RELATION WITH THE TEMPERATURE IN SIBINACOCHA LAKE WATERSHED, PERU, DURING 1984–2019 USING LANDSAT AND ERA5 DATA

ABSTRACT In comparison with many remote parts of the Earth, the watershed Sibinacocha Lake is poorly studied region and the various types of life that habit this region are highly dependent on the waters of this glaciated basin. The present study evaluates the snow cover in this basin associated with changes in air temperatures and precipitation during the period 1984 to 2019. It used the ERA5 high-resolution reanalysis data from the European Centre for Medium-Range Weather Forecasts (ECMWF) and 35 images from the Landsat satellite. The results showed a statistically significant positive trend in maximum air temperatures whose signal is in agreement with previous studies. Seasonal analysis of maximum temperatures showed positive trends in all seasons, indicating that the highest trends occur during winter and the lowest trends during the southern fall. In addition, there was a 26% decrease in snow cover in general in the basin, and it was evidenced that the greater decreases (53%, approximately) occurred in regions below the altitude of 5300 m. In fact, from this contribution of the study comes the need to carry out more research in this region, especially to support decisions covering agriculture, water resources management and biodiversity studies.

Aridity trends in the Middle East and adjacent areas

Available water resources in the Middle East, as one of the most water-scarce regions of the world, have undergone extra pressure due to climatic change, population growth, and economic development during the past decades. The objective of this study is to detect the trends and quantify the changes in aridity with respect to precipitation and potential evapotranspiration in 20 countries of the Middle East and the adjacent area. A pixel-wise trend analysis was conducted on precipitation, potential evapotranspiration, and the aridity index for 71 years from 1948 to 2018. Results showed a statistically significant (|Z| > 1.96) increase up to 106% in aridity (a downward trend in the aridity index) from December to September in most parts of the region. Aridity in October and November had a downward tendency in most parts of the study area. At an annual time scale, 62.5% of the detected trends in aridity were found to be upward (up to 96% increase) due to the combined effects of the decrease in precipitation and the increase in potential evapotranspiration. Annual aridity was found to be downward in 37.5% of the detected trends (up to 61% decrease). The highest and the lowest trends in aridity were found in the north of Sudan (96%) and eastern Arabia (− 61%).

Fear of the Market or Fear of the Competitor? Ambiguity in a Real Options Game

In “Fear of the Market or Fear of the Competitor? Ambiguity in a Real Options Game”, Tobias Hellmann and Jacco Thijssen study the effects of managerial ambiguity aversion on investment decisions in a duopoly. Ambiguity is over the investment project’s expected growth rate (the “trend”). In their continuous-time model they assume that investment commands a first-mover advantage, which, in equilibrium, leads to pre-emption. They show that ambiguity reduces pre-emptive pressure. As a consequence firm value may be increasing in the degree of ambiguity. They also find that the worst-case prior (under which managers compute firm value) is not always given by the lowest trend, but can switch over time between the lowest and the highest trend. Finally, if one of the firms is not ambiguity averse, then its value is increasing in the other firm’s degree of ambiguity.

Doğu Anadolu Koşullarında Farklı Balarısı (Apis mellifera L.) Genotiplerinin Davranış Özelliklerinin Belirlenmesi

Bu çalışmada, Doğu Anadolu koşullarında Buckfast, Karniyol, Kafkas ve Erzurum genotiplerinin hırçınlık, yağmacılık ve oğul eğilimi belirlenmiştir. Araştırmada 2015 yılı üretim döneminde 10‘ar adet Kafkas, Karniyol, Buckfast ve Erzurum genotipine mensup toplam 40 adet koloni kullanılmıştır. Kafkas genotipi 6,22±0,65 adet/koloni ortalama iğne sayısı ile en sakin genotipi oluştururken, Erzurum genotipi 12,12±1,08 adet/koloni ortalama iğne sayısı ile en hırçın genotipi oluşturmuştur. Genotiplerin ortalama iğne sayılarına uygulanan varyans analizi sonucunda hırçınlık eğilimi yönünden genotipler arasındaki farklılık çok önemli bulunmuştur. Yağmacılık eğilimi bakımından Buckfast genotipi 1,57±0,17 adet değerle ilk sırada yer alırken, Karniyol 0,62±0,16 adet değerle yağmacılık eğiliminin en düşük olduğu genotip olmuştur. Oğul eğilimi bakımından genotipler arasındaki fark istatistiksel olarak önemli bulunmuştur.

Analysis and prediction of rainfall trends over Bangladesh using Mann–Kendall, Spearman’s rho tests and ARIMA model

In this study, 60-year monthly rainfall data of Bangladesh were analysed to detect trends. Modified Mann–Kendall, Spearman’s rho tests and Sen’s slope estimators were applied to find the long-term annual, dry season and monthly trends. Sequential Mann–Kendall analysis was applied to detect the potential trend turning points. Spatial variations of the trends were examined using inverse distance weighting (IDW) interpolation. AutoRegressive integrated moving average (ARIMA) model was used for the country mean rainfall and for other two stations data which depicted the highest and the lowest trend in the Mann–Kendall and Spearman’s rho tests. Results showed that there is no significant trend in annual rainfall pattern except increasing trends for Cox’s Bazar, Khulna, Satkhira and decreasing trend for Srimagal areas. For the dry season, only Bogra area represented significant decreasing trend. Long-term monthly trends demonstrated a mixed pattern; both negative and positive changes were found from February to September. Comilla area showed a significant decreasing trend for consecutive 3 months while Rangpur and Khulna stations confirmed the significant rising trends for three different months in month-wise trends analysis. Rangpur station data gave a maximum increasing trend in April whereas a maximum decreasing trend was found in August for Comilla station. ARIMA models predict +3.26, +8.6 and −2.30 mm rainfall per year for the country, Cox’s Bazar and Srimangal areas, respectively. However, all the test results and predictions revealed a good agreement among them in the study.

Changes in surface aerosol extinction trends over China during 1980–2013 inferred from quality‐controlled visibility data

AbstractPollution in China has been attracting extensive attention both globally and regionally, especially due to the perceptually worsening “smog” condition in recent years. We use routine visibility measurements from 1980 to 2013 at 272 World Meteorological Organization stations in China to assess the temporal changes in the magnitude and the sign of pollution trends. A strict and comprehensive quality control procedure is enforced by considering several issues not typically addressed in previous studies. Two methods are used to independently estimate the trend and its significance level. Results show that, in general, a strong increase in aerosol extinction coefficient over the majority of China is observed in the 1980s, followed by a moderate decrease in the 1990s, another increase in the 2000s, and a shift to decrease since around 2006 for some regions. Seasonally, winter and fall trends appear to be the strongest, while summer has the lowest trend.

Assessing the trend of HIV/AIDS mortality rate in Asia and North Africa: an application of latent growth models.

Over the last 30 years, HIV/AIDS has emerged as a major global health challenge. This study evaluates the change of HIV/AIDS mortality rates in Asian and North African countries from 1990 to 2010 using the Global Burden of Disease (GBD) study. HIV/AIDS mortality rates were derived from the GBD database from 1990 to 2010, for 52 countries in Asia and North Africa. First, a Latent Growth Model was employed to assess the change in AIDS mortality rate over time in six different regions of Asia, and also the change in AIDS mortality rate over time for males and females in Asia and North Africa. Finally, Latent Growth Mixture Models (LGMMs) were applied to identify distinct groups in which countries within each group have similar trends over time. Our results showed that increase in mortality rate over time for males is about three times greater than for females. The highest and lowest trend of AIDS mortality rates were observed in South-East Asia and high-income Asia-Pacific regions, respectively. The LGMM allocated most countries in the South and South-East region into two classes with the highest trend of AIDS mortality rates. Although the HIV/AIDS mortality rates are decreasing in some countries and clusters, the general trend in the Asian continent is upwards. Therefore, it is necessary to provide programmes to achieve the goal of access to HIV prevention measures, treatment, care, and support for high-risk groups, especially in countries with a higher trend of AIDS mortality rates.

Ambiguity in a Real Option Game

In this paper we study a two-player investment game with a first mover advantage in continuous time with stochastic payoffs, driven by a geometric Brownian motion. One of the players is assumed to be ambiguous with maxmin preferences over a strongly rectangular set of priors. We develop a strategy and equilibrium concept allowing for ambiguity and show that equilibira can be preemptive (a player invests at a point where investment is Pareto dominated by waiting) or sequential (one player invests as if she were the exogenously appointed leader). Following the standard literature, the worst case prior for the ambiguous player if she is the second mover is obtained by setting the lowest possible trend in the set of priors. However, if the ambiguous player is the first mover, then the worst case prior can be given by either the lowest or the highest trend in the set of priors. This novel result shows that “worst case prior” in a setting with geometric Brownian motion and kappa-ambiguity does not equate to “lowest trend”.

백수 벼의 부위별 아미노산 조성 변화

We examined the contents of amino acids to provide the basic data for the utilization of white panicled rice (Oryza sativa L., WPR) cultured in reclaimed paddy field of Bigumdo of Korea in 2011. WPR used in this study were collected in 1000 ha of reclaimed paddy field of Bigumdo. Crude protein contents of whole rice have the highest in leaf blade, followed by whole grain, leaf sheath and stem. The contents of total amino acids showed the highest trend in region received the most severe damage, but the lowest trend in region of normal growth. The content of glutamic acid was the highest among amino acids in leaf blade, whole grain, leaf sheath and stem collected in all regions, but the content of methionine was the lowest. Therefore, the contents of amino acids showed a similar level between the region occurred WPR and the region of normal growth. Further research on the nutritional aspects of forage must be performed because nutritive values of WPR were influenced by the degree of damage of WPR

The role of remote sensing in monitoring global bulk tropospheric temperatures

The IPCC AR4 (2007) discussed bulk tropospheric temperatures as an indicator of atmospheric energy content. Here, we examine the latest publications about, and versions of, the AR4 data sets. The metric studied is the trend that represents the average rate of atmospheric energy accumulation that relates to increased greenhouse gas forcing. For temperatures from microwave instruments, UAHuntsville's indicates the lowest trend for 1979–2009 and National Oceanic and Atmospheric Administration – Center for Satellite Applications and Research (NOAA-STAR)'s the highest, being slightly higher than Remote Sensing Systems' (RSS). Updated analyses using radiosonde data suggest RSS and STAR experienced spurious warming after the mid-1990s. When satellite and radiosonde data sets are considered, the global trends for 1979–2009 of the lower and mid-troposphere are +0.15 and +0.06°C decade−1 respectively. Error ranges of these estimates, if we do not apply information that indicates some data sets contain noticeable trend problems, are at least ±0.05°C decade−1, which needs reduction to characterize forcing and response in the climate system accurately.

Effect of mixing boars during lairage and pre-slaughter handling on pork quality

Forty-eight crossbred (Large White × Landrace) boars were used in a 2 × 2 factorial design to determine the effects of mixing unfamiliar pigs during lairage and the use of electric goads just prior to slaughter on muscle glycogenolysis and subsequent pork quality. The treatments included 2 mixing treatments (familiar pigs kept together during lairage and unfamiliar pigs mixed during lairage) and 2 handling treatments [minimal handling and negative (electric goad) handling pre-slaughter]. Pigs mixed during lairage had lower muscle glycogen and lactic acid at 5 min, 40 min, and 24 h post-slaughter than familiar pigs kept together during lairage. Mixing of unfamiliar boars also resulted in higher ultimate muscle pH, a higher incidence of dark, firm, dry (DFD) pork, and a lower incidence of pale, soft, exudative (PSE) pork compared with familiar pigs kept together during lairage. The use of an electric goad prior to slaughter did not affect muscle glycogen in mixed pigs, but in unmixed pigs there were large numerical diffferences in glycogen concentrations. The negatively handled unmixed pigs had a trend for lower glycogen concentrations which did not reach significance. This was probably due to the small sample size. However, pigs negatively handled pre-slaughter had higher lactic acid concentration at 5 min post-slaughter compared with minimally handled pigs. This experiment has demonstrated that mixing of unfamiliar boars can have a major impact on pork quality, resulting in a high incidence of DFD pork and a reduced incidence of PSE.

On the suitability of global algorithms for the retrieval of SST from the north Indian Ocean using NOAA/AVHRR data

The errors associated with the SST retrievals from the north Indian Ocean, using global multichannel sea surface temperature (MCSST), nonlinear sea surface temperature (NLSST), and Pathfinder sea surface temperature (PFSST) algorithms are analysed using satellite-sea-truth matchups for NOAA-9 and NOAA-11. The trends associated with the SST retrievals with respect to various independent parameters and simple statistics are analysed to assess the performance of the algorithms. The MCSST and NLSST retrievals have undesirably large trends associated with surface temperature, satellite scan geometry and scan time (day/night); SST retrievals using PFSST show the lowest trends. The simple statistics, mean, and rmsd, are worst for MCSST (0.6 and 1.3 C); they are unsatisfactory for NLSST (0.4 and 0.7 C) and PFSST (0.4 and 0.7 C) also. Considerable improvement in statistics and trends are achievable by regionally optimizing the algorithm coefficients. The mean and RMSD of residuals drop to more than 50% of the values obtained by the use of global coefficients. Regionally optimized NLSST appear to be the better algorithm for the north Indian Ocean in the absence of time-dependent regional coefficients suggested by PFSST.